Continuous local antibiotic perfusion (CLAP) has recently attracted attention as a new drug delivery system for orthopaedic infections. CLAP is a direct continuous infusion of high-concentration gentamicin (1,200 μg/ml) into the bone marrow. As it is a new system, its influence on the bone marrow is unknown. This study aimed to examine the effects of high-concentration antibiotics on human bone tissue-derived cells. Cells were isolated from the bone tissue grafts collected from six patients using the Reamer-Irrigator-Aspirator system, and exposed to different gentamicin concentrations. Live cells rate, apoptosis rate, alkaline phosphatase (ALP) activity, expression of osteoblast-related genes, mineralization potential, and restoration of cell viability and ALP activity were examined by in vitro studies.Aims
Methods
This study aimed to evaluate the accuracy of implant placement with robotic-arm assisted total hip arthroplasty (THA) in patients with developmental dysplasia of the hip (DDH). The study analyzed a consecutive series of 69 patients who underwent robotic-arm assisted THA between September 2018 and December 2019. Of these, 30 patients had DDH and were classified according to the Crowe type. Acetabular component alignment and 3D positions were measured using pre- and postoperative CT data. The absolute differences of cup alignment and 3D position were compared between DDH and non-DDH patients. Moreover, these differences were analyzed in relation to the severity of DDH. The discrepancy of leg length and combined offset compared with contralateral hip were measured.Aims
Methods
With recent progress in cancer treatment, the number of advanced-age patients with spinal metastases has been increasing. It is important to clarify the influence of advanced age on outcomes following surgery for spinal metastases, especially with a focus on subjective health state values. We prospectively analyzed 101 patients with spinal metastases who underwent palliative surgery from 2013 to 2016. These patients were divided into two groups based on age (< 70 years and ≥ 70 years). The Eastern Cooperative Oncology Group (ECOG) performance status (PS), Barthel index (BI), and EuroQol-5 dimension (EQ-5D) score were assessed at study enrolment and at one, three, and six months after surgery. The survival times and complications were also collected.Aims
Methods
Several reports demonstrated the overcoverage of the anterior acetabulum. Anterior CE angle over 46°may be a probable risk factor for pincer FAI syndrome after a rotational acetabular osteotomy. In addition, a highly anteverted femoral neck, reported as a risk factor for posterior impingement, has been found in DDH patients. These findings indicate proper acetabular reorientation is essential to avoid anterior or posterior impingement after periacetabular osteotomy (PAO). The aim of this study was to evaluate the relationship between acetabular three-dimensional (3D) alignment reorientation and clinical range of motion (ROM) after periacetabular osteotomy (PAO). A total of 53 patients who underwent curved PAO (CPO) for DDH from January 2014 to April 2017 were selected. Three (5.7%) of them were lost to follow-up. Therefore, the data from 58 hips, contributed by 50 patients (44 women and 6 men), were included in the analysis. Pre- and postoperative computed tomography (CT) scans from the pelvis to the knee joint were performed and transferred to a 3D template software (Zed Hip; Lexi, Tokyo, Japan). The pelvic plane axis was defined according to the functional pelvic plane. The pre- and postoperative lateral and anterior 3D center-edge (CE) angles were measured on the coronal and sagittal views through the center of the femoral head. The pre- and postoperative 3D center-edge (CE) angles and femoral anteversion were measured and compared with clinical outcomes, including postoperative ROM.Introduction
Methods
The influences of posterior tibial slope on the knee kinematics have been reported in both TKA and UKA. We hypothesized the posterior tibial slope (PTS) would affect the sagittal knee alignment after UKA. The influences of PTS on postoperative knee extension angle were investigated with routine lateral radiographies of the knee after UKA. Twenty-four patients (26 knees; 19 females, 7 males) underwent medial UKA were involved in this study. Average age was 74.8 ± 7.2 years. The mean preoperative active range of motion were − 4.1° ± 6.3°in extension and 123.2° ± 15.5° in flexion. All UKAs were performed using fixed bearing type UKA (Zimmer Biomet, ZUK), with adjusting the posterior slope of the proximal tibial bone cut according to the original geometry of the tibia. Routine lateral radiographies of the knee were examined preoperatively, 6 months after the surgery. PTS and knee extension angles with maximal active knee extension (mEXT) and one-leg standing (sEXT) were radiographically measured. We used the fibular shaft axis (FSA) for the sagittal mechanical axis of the tibia. PTS was defined as the angle between the medial tibial plateau and the perpendicular axis of FSA. Extension angles (mEXT and sEXT) were defined as the angles between FSA and distal femoral shaft axis (positive value for hyperextension). The changes of PTS and the influences of PTS on sEXT at each time period were analyzed using simple linear regression analysis (p<0.05).Introduction
Materials & Methods
Acquiring adaptive soft-tissue balance is one of the most important factors in total knee arthroplasty (TKA). However, there have been few reports regarding to alteration of tolerability of varus/valgus stress between before and after TKA. In particular, there is no enough data about mid-flexion stability. Based on these backgrounds, it is hypothesized that alteration of varus/valgus tolerance may influence post-operative results in TKA. The purpose of this study is an investigation of in vivo kinematic analyses of tolerability of varus/valgus stress before and after TKA, comparing to clinical results. A hundred knees of 88 consecutive patients who had knees of osteoarthritis with varus deformity were investigated in this study. All TKAs (Triathlon, Stryker) were performed using computer assisted navigation system. The kinematic parameters of the soft-tissue balance, and amount of coronal relative movement between femur and tibia were obtained by interpreting kinematics, which display graphs throughout the range of motion (ROM) in the navigation system. Femoro-tibial alignments were recorded under the stress of varus and valgus before the procedure and after implantation of all components. In each ROM (0, 30, 60, 90, 120 degrees), the data of coronal relative movement between femur and tibia (tolerability) were analyzed before and after implantation. Furthermore, correlations between tolerability of varus/valgus and clinical improvement revealed by ROM and Knee society score (KSS) were analyzed by logistic regression analysis.Introduction
Materials and Methods
Patients-reported outcome measures (PROMs) have been reported as the important methods to evaluate clinical outcomes in total knee arthroplasty (TKA). The patient satisfaction score in Knee Society Score (KSS-2011) has been used in the recent literatures. Patient satisfaction was subjective parameter, and would be affected by multiple factors including psychological factors and physical conditions at not only affected joint but also elsewhere in the body. The question was raised regarding the consistency of patient satisfaction score in KSS-2011 to other PROMs. The purpose of this study was to investigate the correlation of patient satisfaction in KSS-2011 to other categories in KSS-2011 and to other PROMs including Forgotten Joint Score (FJS-12), EuroQol-5 Dimensions (EQ-5D) and 25-questions in Geriatric Locomotive Function Scale (GLFS-25). 83 patients over 65 years old with osteoarthritic knees were involved in this study. All patients underwent CR-TKAs (Persona CRR). The means and ranges of demographics were as follows: age; 74.5 years old (65–89), Hip-Knee-Ankle (HKA) angle; 12.4 (−6.2–22.5) in varus. We asked patients to fulfill the questionnaire including KSS-2011, FJS-12, EQ-5D and GLFS-25 at 1-year postoperative follow-up visit. KSS-2011 consisted of 4 categories of questions; patient satisfaction (PS), symptoms, patient expectations (PE), functional activities (FA). We evaluated the correlation of PS to other PROMs using simple linear regression analyses (p<0.001).Introduction
Material & Method
The purpose of this study was to evaluate the in vitro effects of apocynin, an inhibitor of nicotinamide adenine dinucleotide phosphate oxidase (NOX) and a downregulator of intracellular reactive oxygen species (ROS), on high glucose-induced oxidative stress on tenocytes. Tenocytes from normal Sprague-Dawley rats were cultured in both control and high-glucose conditions. Apocynin was added at cell seeding, dividing the tenocytes into four groups: the control group; regular glucose with apocynin (RG apo+); high glucose with apocynin (HG apo+); and high glucose without apocynin (HG apo–). Reactive oxygen species production, cell proliferation, apoptosis and messenger RNA (mRNA) expression of NOX1 and 4, and interleukin-6 (IL-6) were determined in vitro.Aims
Methods
The aim of this study was to investigate the effect of hyperglycaemia on oxidative stress markers and inflammatory and matrix gene expression within tendons of normal and diabetic rats and to give insights into the processes involved in tendinopathy. Using tenocytes from normal Sprague-Dawley rats, cultured both in control and high glucose conditions, reactive oxygen species (ROS) production, cell proliferation, messenger RNA (mRNA) expression of NADPH oxidase (NOX) 1 and 4, interleukin-6 (IL-6), matrix metalloproteinase (MMP)-2, tissue inhibitors of matrix metalloproteinase (TIMP)-1 and -2 and type I and III collagens were determined after 48 and 72 hours Objectives
Methods
Both measured resection technique and gap balancing technique have been important surgical concepts in total knee arthroplasty (TKA). Modified gap technique has been reported to be beneficial for the intra-operative soft tissue balancing in posterior-stabilizing (PS) -TKA. On the other hand, we have found joint distraction force changed soft tissue balance measurement and medial knee instability would be more likely with aiming at perfect ligament balance at extension in modified gap technique. The medial knee stability after TKA was reported to essential for post-operative clinical result. We have developed a new surgical concept named as “medial preserving gap technique” for varus type osteoarthritic (OA) knees to preserve medial knee stability and provide quantitative surgical technique using tensor device. The purpose of this study was to compare post-operative knee stability between medial preserving gap technique (MPGT) and measured resection technique (MRT) in PS-TKA. The subjects were 140 patients underwent primary unilateral PS-TKA for varus type OA knees. The surgical technique was MPGT in 70 patients and MRT in 70 patients. There were no significant differences between two groups in the pre-operative clinical features including age, sex, ROM and deformity. Originally developed off-set type tensor device was used to evaluate both center gap and varus angle with 40 lbs. of joint distraction force. The extension gap preparation was identical in both group. In MPGT group, femoral component size and external rotation angle were adjusted depending on the differences of center gaps and varus angles between extension and flexion before posterior femoral condylar osteotomy. The knee stabilities at extension and flexion were assessed by stress radiographies; varus-valgus stress test with extension and stress epicondylar view with flexion, at one-month and one-year after TKA. We measured joint opening distance (mm) at medial and lateral compartment at both knee extension and flexion. Joint opening distances were compared between two groups using unpaired t-test, and the difference between medial and lateral compartment in each group was compared using paired t- test (p<0.05).Introduction
Material & Method
In recent literatures, medial instability after TKA was reported to deteriorate early postoperative pain relief and have negative effects on functional outcome. Furthermore, lateral laxity of the knee is physiological, necessary for medial pivot knee kinematics, and important for postoperative knee flexion angle after cruciate-retaining total knee arthroplasty (CR-TKA). However, the influences of knee stability and laxity on postoperative patient satisfaction after CR-TKA are not clearly described. We hypothesized that postoperative knee stability and ligament balance affected patient satisfaction after CR-TKA. In this study, we investigated the effect of early postoperative ligament balance at extension on one-year postoperative patient satisfaction and ambulatory function in CR-TKAs. Sixty patients with varus osteoarthritis (OA) of the knee underwent CR-TKAs were included in this study. The mean age was 73.6 years old. Preoperative average varus deformity (HKA angle) was 12.5 degrees with long leg standing radiographs. The knee stability and laxity at extension were assessed by stress radiographies; varus-valgus stress X-ray at one-month after operation. We measured joint separation distance (mm) at medial compartment with valgus stress as medial joint opening (MJO), and distance at lateral compartment with varus stress as lateral joint opening (LJO) at knee extension position. To analyze ligament balance; relative lateral laxity comparing to the medial, varus angle was calculated. New Knee Society Score (NKSS) was used to evaluate the patient satisfaction at one-year after TKA. We measured basic ambulatory functions using 3m timed up and go test (TUG) at one-year after surgery. The influences of stability and laxity parameters (MJO, LJO and varus angle at extension) on one-year patient satisfaction and ambulatory function (TUG) was analyzed using single linear regression analysis (p<0.01).Background
Materials & Methods
Knee osteoarthritis (OA) is a major cause of ambulatory disabilities. Although total knee arthroplasty (TKA) has been reported as the most effective treatment for severe knee OA, quantitative evaluation of ambulatory function have not been well investigated. We hypothesized that better functional recovery would result in better patient satisfaction. The purpose of this study was to quantitatively evaluate ambulatory functional recovery and assess the influence on patient satisfaction after TKA. 90 patients (80 females and 10 males) were involved in this study. The mean age at TKA was 75.2 ± 5.8 years. Patients were subjected to 3 meters timed up and go test (TUG) to evaluate ambulatory function. TUG was performed at 6 time periods; before surgery, 2 weeks, 1, 3, 6 months, and 1 year after surgery. We also asked the patients to fill out the questionnaire of patient satisfaction category in the New Knee Society Score at 1 year after TKA. The sequential changes in TUG were analyzed using repeated measures ANOVA (p<0.05). The influences of each parameter (age, TUGs) on the patient satisfaction score were analyzed with simple regression analysis (p<0.05).Background
Material and Methods
This study aimed to examine the effects of SRT1720, a potent SIRT1 activator, on osteoarthritis (OA) progression using an experimental OA model. Osteoarthritis was surgically induced by destabilization of the medial meniscus in eight-week-old C57BL/6 male mice. SRT1720 was administered intraperitoneally twice a week after surgery. Osteoarthritis progression was evaluated histologically using the Osteoarthritis Research Society International (OARSI) score at four, eight, 12 and 16 weeks. The expression of SIRT1, matrix metalloproteinase 13 (MMP-13), a disintegrin and metalloproteinase with thrombospondin motifs-5 (ADAMTS-5), cleaved caspase-3, PARP p85, and acetylated nuclear factor (NF)-κB p65 in cartilage was examined by immunohistochemistry. Synovitis was also evaluated histologically. Primary mouse epiphyseal chondrocytes were treated with SRT1720 in the presence or absence of interleukin 1 beta (IL-1β), and gene expression changes were examined by real-time polymerase chain reaction (PCR).Objectives
Methods
Diabetes mellitus (DM) is known to impair fracture healing. Increasing evidence suggests that some microRNA (miRNA) is involved in the pathophysiology of diabetes and its complications. We hypothesized that the functions of miRNA and changes to their patterns of expression may be implicated in the pathogenesis of impaired fracture healing in DM. Closed transverse fractures were created in the femurs of 116 rats, with half assigned to the DM group and half assigned to the control group. Rats with DM were induced by a single intraperitoneal injection of streptozotocin. At post-fracture days five, seven, 11, 14, 21, and 28, miRNA was extracted from the newly generated tissue at the fracture site. Microarray analysis was performed with miRNA samples from each group on post-fracture days five and 11. For further analysis, real-time polymerase chain reaction (PCR) analysis was performed at each timepoint.Objectives
Methods
The aim of this study was to compare the post-operative radiographic
and clinical outcomes between kinematically and mechanically aligned
total knee arthroplasties (TKAs). A total of 60 TKAs (30 kinematically and 30 mechanically aligned)
were performed in 60 patients with varus osteoarthritis of the knee
using a navigation system. The angles of orientation of the joint
line in relation to the floor, the conventional and true mechanical
axis (tMA) (the line from the centre of the hip to the lowest point
of the calcaneus) were compared, one year post-operatively, on single-leg
and double-leg standing long leg radiographs between the groups.
The range of movement and 2011 Knee Society Scores were also compared
between the groups at that time.Aims
Patients and Methods
Post-operative (postop) lower limb alignment in unicompartmental knee arthroplasty (UKA) has been reported to be an important factor for postop outcomes. Slight under-correction of limb alignment has been recommended to yield a better clinical outcomes than neutral alignment. It is useful if the postop limb alignment can be predicted during surgery, however, little is known about the surgical factors affecting the postop limb alignment in UKA. The purpose of this study was to examine the influence of the medial tibial joint line elevation on postop limb alignment in UKA. Seventy-four consecutive medial UKAs were enrolled in this study. All the patients received a conventional fixed bearing UKA. Pre-operative (preop) and postop limb alignment was examined using long leg radiograph and lower limb alignment changes were calculated. Femoral and tibial osteotomy thickness were measured during surgery. Medial tibial joint line change was defined as polyethylene thickness minus tibial osteotomy thickness and sawblade thickness (1.27mm). Positive values indicated a tibial joint line elevation. Medial femoral joint line change was defined as femoral distal component thickness (6.5mm) minus femoral distal osteotomy thickness and sawblade thickness. Positive values indicated a femoral joint line reduction. Medial joint distraction width was also calculated by tibial joint line elevation plus femoral joint line reduction. The correlation of lower limb alignment change with polyethylene insert thickness, the medial tibial joint line elevation, femoral joint line reduction, or joint distraction width were analyzed.Background
Methods
Recently, tibial insert design of cruciate-substituting (CS) polyethylene insert is employed and widely used. However, in vivo kinematics of using CS polyethylene insert is still unclear. In this study, it is hypothesized that CS polyethylene insert leads to stability of femoro-tibial joint as well as posterior-stabilized (PS) polyethylene insert, even if PCL is sacrificed after TKA. The purpose of this study is an investigation of in vivo kinematics of femoro-tibial joint with use of CS polyethylene insert before and after PCL resction using computer assisted navigation system and tensor device intra-operatively in TKA. Sixty-one consecutive patients who had knees of osteoarthritis with varus deformity were investigated in this study. All TKAs (Triathlon, Stryker) were performed using computer assisted navigation system. During surgery, using a tensor device, after bony cut of femur and tibia, joint gaps were assessed in 0 and 90 degrees in flexion. Then, CS polyethylene tibial trial insert were inserted after trial implantation of femoral and tibial components, before and after resection of PCL, respectively. The kinematic parameters of the soft-tissue balance, and amount of coronal and sagittal relative movement between femur and tibia were obtained by interpreting kinematics, which display tables throughout the range of motion (ROM) in the navigation system. In each ROM (30, 45, 60, 90, max degrees), the data were analyzed with a ANOVA test, and mean values were compared by the multiple comparison test (Turkey HSD test) (p< 0.05).Introduction
Materials and Methods
Range of motion (ROM) is one of the important factor for better functional outcome after total knee arthroplasty (TKA). In posterior cruciate ligament (PCL) retaining (CR) TKA, adequate PCL function is suggested to be important for better kinematics and ROM. However, intraoperative assessment of PCL function is relatively subjective, thus more objective evaluation is required to improve the functional outcomes after TKA. In clinical practice, tibial posterior sagging sign is well known to indicate PCL deficiency. Hence, we hypothesized that intraoperative femorotibial antero-posterior (AP) changes at 90° of flexion indirectly reflected the PCL function and associated with postoperative maximum flexion angles in CR TKA. The purpose of this study was to investigate the correlation between intraoperative femorotibial AP changes at 90° of flexion and postoperative maximum flexion range in navigated CR TKA. Between March 2014 and March 2015, forty patients with varus osteoarthritis underwent primary TKA. All of the cases were using same types of implant (Triathlon; Stryker Orthopedics, Mahwah, NJ, USA), with an image-free navigation system (Stryker 4.0 image-free computer navigation system; Stryker). PCL was retained and cruciate substituting (CS) inserts were used in all cases. The mean age at the time of surgery was 71.7 ± 6.8 years old (ranging: 62 – 85). The mean follow-up was 10.9 ± 6.4 months. After minimum release of medial and lateral soft tissue, resection of anterior cruciate ligaments, and protection of PCL, registration and kinematic measurements were performed prior to bone resection. The kinematic measurements were performed again after implantation. The center of proximal tibial and distal femur were defined during registration. The point of proximal tibia was projected to the mechanical axis of femur and the distance between the projected point and the distal femur at 90° of flexion were measured and defined as femorotibial AP position. Distal relative to the center of distal femur indicates as minus, and proximal relative to the point indicates as plus. The correlation between the intraoperative changes of AP position and postoperative maximum flexion angles were investigated.Introduction
Methods
Recently, kinematic aligned total knee arthroplasty (TKA) has gained interest for achieving better clinical outcomes over mechanical aligned TKA. The primary goal of kinematic aligned TKA is to position the femoral and tibial components so that the angles and levels of the distal and posterior femoral joint lines and the tibial joint line are each restored to the patient's natural alignment, and not to a neutral limb alignment that is unnatural for most patients. Despite good clinical outcomes reported at short to mid-term follow-up, surgeons should know reasons why this method is useful and safe surgery and carefully assess the long-term outcomes until this new technique is settled as standardized procedure for TKA. The main purpose of the present study was to compare postoperative radiography and clinical scores following kinematic and mechanical aligned TKA. Sixty TKAs—30 kinematic and 30 mechanical aligned—were performed in patients with varus-type osteoarthritis using a navigation system. Using postoperative double-leg and single-leg standing long leg radiographs, joint line orientation angle to the floor, conventional mechanical axis (cMA), and true mechanical axis (tMA; line from hip center to the lowest point of calcaneus) were compared between the two groups. One-year after surgeries, range of motion and the patient-derived score of the 2011 Knee Society Score (2011 KSS), which includes four categories: symptoms, patient satisfaction, patient expectations, and functional activities, e.g., walking/standing, standard activities, advanced activities, and discretionary activities, were compared between the two groupsPurpose
Methods
As the aging society progresses rapidly in Japan, the number of elderly patients underwent TKA is increasing. These elderly patients do not expect to do sports, but regain independency in the activity of daily living. Therefore, we measured basic ambulatory function quantitatively using 3m timed up and go (TUG) test. We clinically experienced patient with medially unstable knee after TKA was more likely to result in the unsatisfactory outcome. We hypothesized that post-operative knee stability influenced ambulatory function recovery after TKA. In this study, we evaluated ambulatory function and knee stability quantitatively, and analyzed the effect of knee stability on the ambulatory function recovery after TKA. Seventy nine patients with varus type osteoarthritic knees underwent TKA were subjected to this study. The mean age of surgery was 72.4 years old. Preoperative standing coronal deformity was 9.6 degrees in varus. TUG test results in less duration with faster ambulatory function. TUG (seconds) was measured at 3 time periods; pre-operatively, at hospital discharge and 1year after surgery. To standardize TUG recovery time during 1 year after TKA, we defined TUG recovery rate as the percentage of recovery time to the pre-operative TUG as shown in the following equation. TUG recovery rate (%) = (TUG pre-op –TUG 1y po) / TUG pre-op ×100 We also evaluated the knee stability at hospital discharge and 1year after surgery. The knee stability at extension and flexion were assessed by varus and valgus stress radiography using Telos (10kg) and stress epicondylar view with 1.5kg weight at the ankle respectively. Image analyzing software was used to measure joint separation distance (mm) at medial as medial joint opening (MJO) and at lateral as lateral joint opening (LJO) at both knee extension and flexion. (Fig.1) The sequential change of TUG was analyzed using repeated measures ANOVA (p<0.05). The influence of joint opening distances (MJO and LJO at extension and flexion) on TUG 1y po and TUG recovery rate were analyzed using simple linear regression analysis (p<0.05).Objective
Materials & Methods
Total knee arthroplasty (TKA) is a successful technique for treating painful osteoarthritic knees. However, the patients' satisfaction is not still comparable with total hip arthroplasty. Basically, the conditions with operated joints were anterior cruciate ligament (ACL) deficient knees, thus, the abnormal kinematics is one of the main reason for the patients' incomplete satisfaction. Bi-cruciate stabilized (BCS) TKA was established to reproduce both ACL and posterior cruciate ligament (PCL) function and expected to improve the abnormal kinematics. However, there were few reports to evaluate intraoperative kinematics in BCS TKA using navigation system. Hence, the aim in this study is to reveal the intraoperative kinematics in BCS TKA and compare the kinematics with conventional posterior stabilized (PS) TKA. Twenty five consecutive subjects (24 women, 1 men; average age, 77 years; age range, 58–85 years) with varus osteoarthritis undergoing navigated BCS TKA (Journey II, Smith&Nephew) were enrolled in this study. An image-free navigation system (Stryker 4.0 image-free computer navigation system; Stryker) was used for the operation. Registration was performed after minimum medial soft tissue release, ACL and PCL resection, and osteophyte removal. Then, kinematics including tibiofemoral rotational angles from maximum extension to maximum flexion were recorded. The measurements were performed again after implantation. We compared the kinematics with the kinematics of paired matched fifty subjects who underwent conventional posterior stabilized (PS) TKA (25 subjects with Triathlon, Stryker; 25 subjects with PERSONA, ZimmerBiomet) using navigation statistically.PURPOSE
Materials and Methods
Although gap balancing technique has been reported to be beneficial for the intra-operative soft tissue balancing in posterior-stabilized (PS)-TKA, excessive release of medial structures for achieving perfect ligament balance would be more likely to result in medial instability, which would deteriorate post-operative clinical results. We have modified conventional gap balancing technique and devised a new surgical concept; named as “medial gap technique” aiming at medial stability with permitting lateral looseness, as physiologically observed in normal knee. We compared intra-operative soft tissue balance between medial gap technique (MGT) and measured resection technique (MRT) in PS-TKAs.Introduction
Objective
The influence of amount of tibial posterior slope changes on joint gap and postoperative range of motion was investigated in 35 patients undergoing unicompartmental knee arthroplasty (UKA). Component gap between the medial tibial osteotomy surface and the femoral trial prosthesis was measured throughout the range of motion using a tensor. The mean tibial posterior slope decreased from 10.2 to 7.3 degrees. Increased tibial slope change was positively correlated with component gap differences of 90° −10°, 120° −10°, and 135° −10° and negatively correlated with postoperative extension angle. Increasing tibial slope should be avoided to achieve full extension angle after UKA.
To investigate the tibiofemoral rotational profiles during surgery in navigated posterior-stabilized (PS) total knee arthroplasty (TKA) and investigated the effect on postoperative maximum flexion angles. At first, twenty-five consecutive subjects (24 women and 1 man; age: mean, 77 years; range, 58–85 years) with varus osteoarthritis treated with navigated PS TKA (Triathlon, Stryker, Mahwah, NJ) were enrolled in this study. Kinematic parameters, including the tibiofemoral rotational angles from maximum extension to maximum flexion, were recorded thrice before and after PCL resections, and after implantation. The effect of PCL resection and component implantation on tibiofemoral rotational kinematics was statistically evaluated. Then, the effect of tibiofemoral rotational alignment changes on the postoperative maximum angles were retrospectively examined with 96 subjects (84 women, 12 men; average age, 76 years; age range, 56–88 years) who underwent primary TKA.Purpose
Materials and Methods
The influence of soft tissue balance in mobile-bearing posterior-stabilized (PS) total knee arthroplasty (TKA) on the patellofemoral (PF) joint was investigated in thirty varus-type osteoarthritis patients. Intraoperative soft tissue balance including joint component gap and varus/valgus ligament balance and the medial/lateral patellar pressure were measured throughout the range of motion after the femoral component placement and the PF joint repair. The lateral patellar pressure, which was significantly higher than the medial side in the flexion arc, showed inverse correlation with the lateral laxity at 60° and 90° of flexion. The lateral patellar pressure at 120° and 135° of flexion also inversely correlated with the postoperative flexion angle. Surgeons should take medial and lateral laxity into account when considering PF joint kinematics influencing postoperative flexion angle in PS TKA.
Recently, tibial insert design of cruciate-substituting (CS) polyethylene insert is employed. However, in vivo kinematics of using CS polyethylene insert is still unclear. In this study, it is hypothesized that CS polyethylene insert leads to stability of femolo-tibial joint as well as posterior-stabilized (PS) polyethylene insert, even if PCL is sacrificed after TKA. The purpose of this study is an investigation of in vivo kinematics of femolo-tibial joint with use of CS polyethylene insert before and after PCL resction using computer assisted navigation system intra-operatively in TKA. Twenty-four consecutive patients who had knees of osteoarthritis with varus deformity were investigated in this study. All TKAs (Triathlon, Stryker) were performed using computer assisted navigation system. In all patients, difference between extension and flexion gap was under 3mm after bony cut of femur and tibia. During surgery, CS polyethylene tibial trial insert were inserted after trial implantation of femoral and tibial components, before and after resection of PCL, respectively. The kinematic parameters of the soft-tissue balance, and amount of coronal (valgus/varus), sagittal (anterior/posterior) and rotational relative movement between femur and tibia were obtained by interpreting kinematics, which display tables throughout the range of motion (ROM) (Figure1). During record of kinematics, the surgeon gently lifted the experimental thigh three times, flexing the hip and knee. In each ROM (30, 45, 60, 90, max degrees), the data were analyzed with paired t-test, and an ANOVA test, and mean values were compared by the multiple comparison test (Turkey HSD test) (p < 0.05).Introduction
Materials and Methods
As the aging society progresses rapidly, the number of patients underwent total knee arthroplasty (TKA) is increasing especially for the elderly population. In Japan, the average age for TKA is around 75 years old. Japanese Orthopaedic Association indicated a new clinical entity of musculoskeletal ambulation disability symptom complex (MADS) to define the higher risk of fall and ambulatory disability in the elderly population in 2006. The diagnosing criteria for MADS consists of 2 simple performance tests. 3m timed up and go test (TUG) evaluates ambulatory function, and one leg standing time (ST) assesses balancing ability. In this study, we analyzed the effect of TKA on the ambulatory function by quantitative measurement using 2 simple performances test: TUG and ST.Introduction
Objective
To achieve well aligned and balanced knee is essential for the post-operative outcome in total knee arthroplasty (TKA). Gap balancing technique can adjust the bone cut depending on the soft tissue balance in addition to soft tissue releases. Therefore, gap balancing technique would be more advantageous in soft tissue balance comparing to measured resection technique (MRT) in which soft tissue balancing relayed on soft tissue releases alone. Nevertheless, the influence of surgical technique on the post-operative knee stability has not been fully investigated. We introduced a new surgical technique (medial gap technique: MGT) according to modified gap technique regarding medial knee stability as important. The intra-operative soft tissue balance and post-operative knee stability were compared between MGT and MRT in posterior-stabilized (PS) TKA for varus type osteoarthritic knees.Introduction
Objective
The advance of surgical technique and implant design have led to improvement in total hip arthroplasty (THA), and short stem THA is now gaining number as a treatment option for younger patients to preserve bone in the proximal femur for a future revision. The SMF stem is shorter stem, and requires a slightly higher neck resection and implanted in slight varus to contact at lateral cortex. Developmental dysplasia of the hip (DDH) is the most common cause to hip osteoarthritis (OA) in Japan, and the morphology of the dysplastic femur is narrow canal and increased anteversion. Thus, the purpose of this study is to evaluate the SMF stem design can fit for Japanese patients, using CT based 3-D template planning. We evaluated 30 patients who required THA in our institution. Inclusion criteria are hip OA, but cases with post-trauma, post-osteotomy, and any other hip disease in childhood are excluded. Patients were selected with their femoral anteversion, based on the dispersion of anteversion in dysplastic hip population, which was reported by Noble and collegues in 2003. Preoperative planning with ZedHip software (Lexi, Japan) was performed by established protocol. The center of socket was placed at 15mm proximal from teardrop and medialized to primary acetabulum, with 40° of radiographic inclination and 20° of anteversion. Neck resection of femur was 20mm proximal from the top of smaller trochanter, and stem was placed with lateral fit at distal and medial fit at calcar with appropriate size. Stem offset was selected by leg extension and balanced shenton line. Finally, ROM simulation was performed and the socket anteversion was arranged to achieve the optimal ROM. And then, SMF stem alignment and appropriate fitting was evaluated in Japanese OA cases.Introduction
Methods
The purpose of this study was to evaluate periprosthetic bone mineral density (BMD) changes around a cementless short tapered-wedge stem and determine correlations between BMD changes and various clinical factors, including daily activity, after total hip arthroplasty (THA) with a short tapered-wedge stem. The study included 65 patients (65 joints) who underwent THA with a TriLock stem. At baseline, and 6, 12, and 24 months postoperatively, BMDs of the seven Gruen zones were evaluated using dual-energy X-ray absorptiometry. Correlations were determined between BMD changes and clinical factors, including the Harris hip score, body mass index, University of California at Los Angeles (UCLA) activity rating score, age at surgery, and initial lumbar BMD.Purpose
Methods
Many factors can influence postoperative knee flexion angle after total knee arthroplasty (TKA), and range of flexion is one of the most important clinical outcomes. Although many studies have reported that postoperative knee flexion is influenced by preoperative clinical conditions, the factors which affect postoperative knee flexion angle have not been fully elucidated. As appropriate soft-tissue balancing as well as accurate bony cuts and implantation has traditionally been the focus of TKA success, in this study, we tried to investigate the influence of intraoperative soft-tissue balance on postoperative knee flexion angle after cruciate-retaining (CR) TKA using a navigation system and offset-type tensor. We retrospectively analyzed 55 patients (43 women, 12 men) with osteoarthritis who underwent TKA using the same mobile-bearing CR-type implant (e.motion; B. Braun Aesculap, Germany). The mean age at the time of surgery was 74.2 (SD 7.3) years. The exclusion criteria for this study included valgus deformity, severe bony defect requiring bone graft or augmentation, revision TKA, active knee joint infection, and bilateral TKA. Intraoperative soft-tissue balance parameters such as varus ligament balance and joint component gap were measured in the navigation system (Orthopilot 4.2; B. Braun Aesculap) while applying 40-lb joint distraction force at 0°, 10°, 30°, 60°, 90°, and 120° of knee flexion using an offset-type tensor with the patella reduced. Varus ligament balance was defined as the angle (degree, positive value in varus imbalance) between the seesaw and platform plates of the tensor that was obtained from the values displayed by the navigation system. To determine clinical outcome, we measured knee flexion angle using a goniometer with the patient in the supine position before and 2 years after surgery. Correlations between the soft-tissue parameters and postoperative knee flexion angle were analyzed using simple linear regression models. Pre- and postoperative knee flexion angle were also analyzed in the same manner.Introduction / Purpose
Methods
Failure of acetabular components has been reported to lead to large bone defects, which determine outcome and management after revision total hip arthroplasty (THA). Although Kerboull-type (KT) plate (KYOCERA Medical Corporation, Kyoto, Japan) has been used for compensating large bone loss, few studies have identified the critical risk factors for failure of revision THA using a KT plate. Therefore, the aim of this study is to evaluate the relationship between survival rates for radiological loosening and the results according to bone defect or type of graft. This study included patients underwent revision THA for aseptic loosening using cemented acetabular components with a KT plate between 2000 and 2012. Bone defects were filled with beta Tricalcium phosphate (TCP) granules between 2000 and 2003 and with Hydroxyapatite (HA) block between 2003 and 2009. Since 2009, we have used femoral head balk allografts. Hip function was evaluated by using the Japanese Orthopaedic Association (JOA) score and University of California, Los Angeles (UCLA) activity. Acetabular defects were classified according to the American Academy of Orthopedic Surgeons (AAOS) classification. The postoperative and final follow-up radiographs were compared to assess migration of the implant. Kaplan–Meier method for cumulative probabilities of radiographic failure rate, and the comparison of survivorship curves for various subgroups using the log-rank test were also evaluated. Logistic regression was performed to examine the association of such clinical factors as the age at the time of operation, body mass index, JOA score, UCLA activity score, and AAOS classification with radiographic failure. Odds ratios (ORs) and 95% CIs were calculated. Multivariate analysis was performed to adjust for potential confounders by clinical factors. Values of Introduction
Patients and methods
The goal of total knee arthroplasty (TKA) is to achieve a stable and well-aligned tibiofemoral and patello-femoral (PF) joint, aiming at long-term clinical patient satisfaction. The surgical principles of both cruciate retaining (CR) and posterior stabilized (PS) TKA are accurate osteotomy and proper soft tissue balancing. We have developed an offset-type tensor, and measured intra-operative soft tissue balance under more physiological joint conditions with femoral component in place and reduced PF joint. In this study, we measured intra-operative soft tissue balance and assessed the post-operative knee joint stability quantitatively at one month, six months and one year after surgery, and compared these parameters between CR and PS TKAs. Sixty patients with varus osteoarthritis of the knee underwent TKAs (30 CR TKAs: CR and 30 PS TKAs: PS). Mean varus deformity in standing position was 11.1 degrees in CR, and 12.6 degrees in PS. All TKAs were performed by a single surgeon with measured resection technique. The external rotation of posterior femoral condyle osteotomy was performed according to surgical epicondylar axis in pre-operative CT. We measured intra-operative soft tissue balance using an offset-type tensor with 40 lbs of joint distraction force at 0, 10, 30, 45, 60, 90, 120 and 135 degrees of flexion. The joint component gap (mm) and varus angle (degrees) were measured at each flexion angles. One month, six months and one year after surgery, we evaluated the knee stability at extension by varus and valgus stress radiography using Telos (10kg) and at flexion by epicondylar view with 1.5kg weight at the ankle. We measured joint separation distance at medial as medial joint looseness (MJL) and at lateral as lateral joint looseness (LJL). Intra-operative measurements and post-operative joint stabilities were compared between CR and PS using unpaired t-test. The change of joint looseness in each group was analyzed using repeated measures ANOVA.Objective
Material and Method
Data on varus-valgus and rotational profiles can be obtained during navigated total knee arthroplasty (TKA). Such intraoperative kinematic data might provide instructive clinical information for refinement of surgical techniques, as well as information on the anticipated postoperative clinical outcomes. However, few studies have compared intraoperative kinematics and pre- and postoperative clinical outcomes; therefore, the clinical implications of intraoperative kinematics remain unclear. In clinical practice, subjects with better femorotibial rotation in the flexed position often achieve favorable postoperative range of motion (ROM); however, no objective data have been reported to prove this clinical impression. Hence, the present study aimed to investigate the correlation between intraoperative rotation and pre- and postoperative flexion angles. Twenty-six patients with varus osteoarthritis undergoing navigated posterior-stabilized TKA (Triathlon, Stryker, Mahwah, NJ) were enrolled in this study. An image-free navigation system (Stryker 4.0 image-free computer navigation system; Stryker) was used for the operation. Registration was performed after minimum soft tissue release and osteophyte removal. Then, maximum internal and external rotational stress was manually applied on the knee with maximum extension and 90° flexion by the same surgeon, and the rotational angles were recorded using the navigation system. After knee implantation, the same rotational stress was applied and the rotational angles were recorded again. In addition, ROM was measured before surgery and at 1 month after surgery. The correlation between the amount of pre- and postoperative tibial rotation and ROM was statistically evaluated.Background
Materials and Methods
Surgeons sometimes encounter moderate or severe varus deformed osteoarthritic cases in which medial substantial release including semimembranosus is compelled to appropriately balance soft tissues in total knee arthroplasty (TKA). However, medial stability after TKA is important for acquisition of proper knee kinematics to lead to medial pivot motion during knee flexion. The purpose of the present study is to prove the hypothesis that step by step medial release, especially semimembranosus release, reduces medial stability in cruciate-retaining (CR) total knee arthroplasty (TKA). Twenty CR TKAs were performed in patients with moderate varus-type osteoarthritis (10° < varus deformity <20°) using the tibia first technique guided by a navigation system (Orthopilot). During the process of medial release, knee kinematics including tibial internal rotation and anterior translation during knee flexion were assessed using the navigation system at 3 points; (1) after anterior cruciate ligament resection (pre-release), (2) medial tibial and femoral osteophyte removal and release of minimum deep layer of medial collateral ligament (minimum release) and (3) release of semimembranosus (semimembranosus release). In addition, the kinematics after all prostheses implantation (semimembranosus release group) were assessed and compared with those assessed in another 20 patients in which only minimum release was performed (minimum release group).Purpose
Methods
Appropriate osteotomy alignment and soft tissue balance are essential for the success of total knee arthroplasty (TKA). The management of soft tissue balance still remains difficult and it is left much to the surgeon's subjective feel and experience. We developed an offset type tensor system for TKA. This device enables objective soft tissue balance measurement with more physiological joint conditions with femoral trial component in place and patello-femoral (PF) joint reduced. We have reported femoral component placement decreased extension gap. The purpose of the present study was to analyze the influence of femoral component size selection on the decrease of extension gap in posterior-stabilized (PS) TKA. 120 varus type osteoarthritic knees implanted with PS TKAs (NexGen LPS flex: Zimmer) were subjected to this study. All TKAs were performed using measured resection technique with anterior reference. The femoral component size was evaluated intra-operatively using conventional femoral sizing jig. The selected femoral component size was expressed by the antero-posterior (AP) size increase (mm) comparing to that of original femoral condyles. Gap measurements were performed using a newly developed offset type tensor device applying 40lbs (178N) of joint distraction force. Firstly, conventional osteotomy gaps (mm) were measured at extension and flexion. Secondary, component gaps (mm) after femoral trial placement with PF joint reduced were evaluated at 0° and 90° of knee flexion. To compare conventional osteotomy gaps and component gaps, estimated extension and flexion gaps were calculated by subtracting the femoral component thickness at extension (9mm) and flexion (11mm) from conventional osteotomy gaps respectively. The decrease of gap at extension and flexion were calculated with estimated gaps subtracted by component gaps. The simple linear regression analysis was used to evaluate the influence of selected femoral component size on the decrease of gap after femoral component placement.Introduction
Material & Method
The tibia first technique in unicompartmental knee arthroplasty (UKA) may have the advantage that surgeons can obtain a balanced flexion-extension gap. However, changes of the soft tissue tension during UKA has not been elucidated yet. The purpose of this study was to examine the correlation between the soft tissue tension before the femoral osteotomy and after the femoral component in place using the tensor in UKA. Thirty UKAs for isolated medial compartmental osteoarthritis or idiopathic osteonecrosis were assessed. The mean age was 71.8±8.5 years old (range: 58–85), and the average coronal plane femorotibial angle (FTA) was 181.2±3.2 degree preoperatively. All the patients received a conventional medial Zimmer Unicompartmental High Flex Knee System (Zimmer Inc, Warsaw, Ind). The actual values of the proximal and posterior femoral osteotomy were calculated by adding the thickness of the bone saw blades to the thickness of the bony cut. Using a UKA tensor which designed to facilitate intra-operative soft tissue tension throughout the range of motion (ROM), the original gap before the femoral osteotomy, the component gap after the femoral osteotomy, and component placement were assessed under 20 lb distraction forces. (Figure 1)Purpose
Methods
Patients planning to undergo total knee arthroplasty (TKA), especially in Asian and Middle Eastern countries, usually expect to be able to perform activities requiring knee flexion such as sitting cross-legged or kneeling with ease after the surgery. Postoperative range of motion (ROM) can be affected by multiple factors such as the patient's gender, age, preoperative ROM, diagnosis, the surgeon's technique, the pre- and post-operative rehabilitation program, and the design of the prosthesis. Among these, the choice of the prosthesis depends on the surgeon's preference. As a result, several trials and studies have been conducted to improve postoperative ROM by modifying prosthesis design. The present study aimed to examine the results of TKA with the NexGen LPS-Flex system (Zimmer, Warsaw, Indiana), which is one of several high-flexion total knee prostheses that were designed to achieve a wide ROM for osteoarthritis in the valgus knee. A total of 27 primary TKAs in 26 osteoarthritis patients with valgus knee deformities (femorotibial angle (FTA) ≤ 170°) were performed using the NexGen LPS-Flex fixed prosthesis between July 2003 and December 2011. The patients included 2 men (7.7%, 2 knees) and 24 women (92.3%, 25 knees) with a mean age of 72.6 years (range, 59 to 83 years) at the time of the surgery. The mean duration of follow-up after surgery was 50.1 months (range, 24 to 126 months). Knee Society Knee Score (KSKS), Knee Society Function Score (KSFS), maximum flexion angle, maximum extension angle, and radiological femorotibial angle (FTA) were evaluated pre- and post-operatively. The mean preoperative KSKS and KSFS were 42.6 points (SD 7.5) and 41.1 points (SD 8.6), respectively, which improved after surgery to 82.2 points (SD 8.2) and 80.9 points (SD 7.6), respectively (P < 0.01). The maximum flexion angle improved from 109.1° (SD 23.1) to 117.3° (SD 12.4) postoperatively, but it did not reach statistical significance (P = 0.097). The preoperative maximum extension angle improved from −9.7° (SD 10.8) to −3.6° (SD 4.9) postoperatively (p < 0.05). The mean radiological FTA was 166.4° (SD 4.2; range: 155° − 170°) preoperatively and 172.4° (SD 2.7; range: 168° − 178°) at the final follow-up, and the difference was statistically significant (P < 0.01). None of the patients had undergone revision surgery by the final follow-up. As a conclusion, the results of the present study showed that the use of NexGen LPS-Flex implant in TKA for knee osteoarthritis with valgus deformity produced a satisfactory improvement in the clinical and radiological outcomes. Further studies on the outcomes of other prosthesis are needed to determine whether the NexGen LPS-Flex implant is advantageous for osteoarthritis patients with valgus knees who undergo TKA, and further large-scale studies with longer term follow-up are necessary to verify our results.
MicroRNAs (miRNAs ) are small non-coding RNAs
that regulate gene expression. We hypothesised that the functions
of certain miRNAs and changes to their patterns of expression may
be crucial in the pathogenesis of nonunion. Healing fractures and
atrophic nonunions produced by periosteal cauterisation were created
in the femora of 94 rats, with 1:1 group allocation. At post-fracture
days three, seven, ten, 14, 21 and 28, miRNAs were extracted from
the newly generated tissue at the fracture site. Microarray and
real-time polymerase chain reaction (PCR) analyses of day 14 samples
revealed that five miRNAs, miR-31a-3p, miR-31a-5p, miR-146a-5p,
miR-146b-5p and miR-223-3p, were highly upregulated in nonunion.
Real-time PCR analysis further revealed that, in nonunion, the expression
levels of all five of these miRNAs peaked on day 14 and declined
thereafter. Our results suggest that miR-31a-3p, miR-31a-5p, miR-146a-5p,
miR-146b-5p and miR-223-3p may play an important role in the development
of nonunion. These findings add to the understanding of the molecular mechanism
for nonunion formation and may lead to the development of novel
therapeutic strategies for its treatment. Cite this article:
Increased long-term survival of TKA is becoming more important. Several studies have confirmed that optimal positioning and alignment of prosthetic components is crucial for the best long-term results. Therefore, the purpose of the current study was to compare the postoperative alignment and sizing of femoral prosthesis among patients performed by 3 different navigation systems. Twenty patients who underwent primary TKA (E. motion; B. Braun Aesculap, Tuttlingen, Germany) using a CT-free navigation system (OrthoPilot v 4.2) by modified gap technique were enrolled in this study. The results of this study group were retrospectively compared with those in a control group of 20 matched-paired posterior stabilized TKAs (Triathlon;Stryker; Mahwah, NJ, USA) which were using another CT-free navigation system (Stryker Navigation System) by measured technique and 20 matched-paired posterior stabilized TKAs (Press-fit Condylar prosthesis; DePuy, Tokyo, Japan) using CT-based navigation system (VectorVision) by measured technique. Several parameters were evaluated for each patient using Athena Knee (Softcube Co, Ltd. Osaka, Japan), 3-D image-matching software. The coronal component angles and sagittal component angles were measured in relation to mechanical axis (MA). In addition, axial femoral component angle was measured in relation to surgical epicondylar axis (SEA) and axial tibial component angle was measured in relation to Akagi line.Introduction
Methods
The axis of the fibula in the sagittal plane are known as a landmark for the extramedullary guide in order to minimize posterior tibial slope measurement error in the conventional total knee arthroplasty (TKA). However, there are few anatomic studies about them. We also wondered if the fibula in the coronal plane could be reliable landmark for the alignment of the tibia. This study was conducted to confirm whether the fibula is reliable landmark in coronal and sagittal plane. We evaluated 60 osteoarthritic knees after TKA using Athena Knee (SoftCube Co, Ltd, Osaka, Japan) 3-D image-matching software. Angle between the axis of the fibula (FA) and the mechanical axis (MA) in the coronal and sagittal plane were measured.Background:
Methods:
Rapid increase of aged population has been one of major issue affecting national health care plan in Japan. In 2006, Japanese Orthopaedic Association indicated a new clinical entity of musculoskeletal ambulation disorder symptom complex (MADS) to define the higher risk of fall and ambulatory disability in the elderly population caused by musculoskeletal disorders. Osteoarthritis of the knee is one of major cause of MADS. The number of patients with MADS underwent total knee arthroplasty (TKA) had been increased in Japan, and also expected to increase worldwide in the near future. The effectiveness of TKA for the patient with MADS would be a key issue for the patient satisfaction in TKA. In the present study, we analyzed the influence of pre-operative factors on the ambulatory functions in the patients of primary TKA. 132 patients with osteoarthritic knees implanted with posterior-stabilized (PS) TKAs were subjected to this study. There were 113 female and 19 male patients. The mean age of the patients was 73.6 years (range, 59 to 87 years). Patients were pre-operatively subjected to 2 functional performance tests which were essential tests for MADS diagnosis. Firstly, 3 meter timed up and go test (TUG) was used to evaluate ambulation ability. Secondary one leg standing time (ST) with open eyes was measured with both operated and non-operated leg to assess balancing ability. MADS was diagnosed if TUG and ST were not less than 11 seconds and/or less than 15 seconds respectively. The influence of each pre-operative factor was evaluated simple linear regression analysis (p < 0.05). Pre-operative factors consisted of age, sex, weight, height, BMI, standing femoro-tibial angle (FTA) and active knee range of motion.[Introduction]
[Material & Method]
The goal of total knee arthroplasty (TKA) is to achieve a stable and well-aligned tibiofemoral and patello-femoral (PF) joint, aiming at long-term clinical patient satisfaction. The surgical principles of both cruciate retaining (CR) and posterior stabilized (PS) TKA are accurate osteotomy and proper soft tissue balancing. We have developed an offset-type tensor, and measured intra-operative soft tissue balance under more physiological joint conditions with femoral component in place and reduced PF joint. In this study, we measured intra-operative soft tissue balance and assessed the early post-operative knee joint stability quantitatively, and compared these parameters between CR and PS TKA. Seventy patients with varus osteoarthritis of the knee underwent TKAs (35 CR TKAs: CR and 35 PS TKAs: PS). Mean varus deformity in standing position was 9.8 degrees in CR, and 10.7 degrees in PS (p = 0.45). All TKAs were performed by a single surgeon with measured resection technique. The external rotation of posterior femoral condyle osteotomy was performed according to surgical epicondylar axis (SEA) in pre-operative CT. We measured intra-operative soft tissue balance using an offset-type tensor with 40 lbs of joint distraction force at 0, 10, 30, 45, 60, 90, 120 and 135 degrees of flexion. The joint component gap (mm) and varus angle (degrees) were measured at each flexion angle. Four weeks after operation, we evaluated the knee stability at extension by varus and valgus stress radiography using Telos (10 kg) and at flexion by epicondylar view with 1.5 kg weight at the ankle. We measured joint separation distance at medial as medial joint looseness (MJL) and at lateral as lateral joint looseness (LJL). Joint looseness was defined as the average of MJL and LJL. Intra-operative measurements and post-operative joint stabilities were compared between CR and PS using unpaired t-test.Objective
Material and Method
Recently, tibial insert design of cruciate-substituting (CS) polyethylene insert is employed. However, in vivo kinematics of using CS polyethylene insert is still unclear. In this study, it is hypothesized that CS polyethylene insert leads to stability of femolo-tibial joint as well as posterior-stabilized polyethylene insert, even if posterior cruciate ligament (PCL) is sacrificed after total knee arthroplasty (TKA). The purpose of this study is an investigation of in vivo kinematics of three different tibial insert designs using computer assisted navigation system intra-operatively in TKA. Sixty-four consecutive patients who had knees of osteoarthritis with varus deformity were investigated in this study. All TKAs (Triathlon, Stryker, New Jersey, USA) were performed using computer assisted navigation system. During surgery, three different designs of polyethylene tibial trial inserts (PS, CS, and cruciate-retaining (CR) polyethylene insert) were inserted respectively after implantation of femoral and tibial components. The kinematic parameters of the soft-tissue balance were obtained by interpreting kinematics curve, which display bicompartmental gaps throughout the range of motion (ROM) after implantation of each trial insert (Figure. 1). During record of kinematics, the surgeon gently lifted the experimental thigh three times, flexing the hip and knee. Deviation of these three values in each ROM was calculated in each tibial insert in each patient for descriptive analysis.Introduction
Materials and Methods
Failures in fracture healing are mainly caused by a lack of neovascularization. We have previously demonstrated that G-CSF-mobilized peripheral blood (GM-PB) CD34+ cells, an endothelial progenitor enriched cell population, contributed to fracture healing via vasculogenesis and osteogenesis. We postulated the hypothesis that local transplantation of culture expanded bone marrow (cEx-BM) CD34+ cells could exhibit therapeutic potential for fracture healing. BM CD34+ cells were cultured in specific medium with 5 growth factors for 1week. A reproducible model of femoral fracture was created in nude rats with periosteum cauterization, which leads to nonunion at 8 weeks post-fracture. Rats received local administration of the following cells or PBS alone(1)cEx-BM, (2)BM, (3)GM-PB CD34+ cells or (4)PBS.Introduction
Materials
CXC chemokine receptor 4 (CXCR4) is a specific receptor for stromal-derived-factor 1 (SDF-1). SDF-1/CXCR4 interaction contributes to the regulation of endotherial progenitor cell (EPC) recruitment in ischemic tissues. The purpose of this study is to investigate the mechanistic function of CXCR4 on EPCs for bone fracture healing. We made CXCR4 gene knockout mice using the Cre/loxP system. A reproducible model of femoral fracture was created in both Tie2-Cre CXCR4 knockout mice (CXCR4KO) and wild type mice (control). To evaluate gain function of the SDF-1/CXCR4 pathway, we set three groups of the SDF-1 intraperitoneally injected group, wild type group, and SDF-1 injected CXCR4 KO group.Introduction
Materials and methods
The therapeutic potential of hematopoietic stem cells for fracture healing has been demonstrated with mechanistic insight of vasculogenesis and osteogenesis enhancement. Lnk has recently been proved an essential inhibitory signaling molecule in SCF-c-Kit signaling pathway for stem cell self-renewal demonstrating enhanced hematopoietic and osteogenic reconstitution in Lnk-deficient mice. We investigated the hypothesis that down regulation of Lnk enhances regenerative response via vasculogenesis and osteogenesis in fracture healing. A reproducible model of femoral fracture was created in mice. Immediately after fracture creation, mice received local administration of the following materials with AteloGene, 10μM (1)Lnk siRNA, (2)control siRNA.Introduction
Methods
In order to permit soft tissue balancing under more physiological conditions during total knee arthroplasties (TKAs), we developed an offset type tensor to obtain soft tissue balancing throughout the range of motion with reduced patella-femoral (PF) and aligned tibiofemoral joints and reported the intra-operative soft tissue balance assessment in cruciate-retaining (CR) and posterior-stabilized (PS) TKA [1, 2]. However, the soft tissue balance in unicompartmental knee arthroplasty (UKA) is unclear. Therefore, we recently developed a new tensor for UKAs that is designed to assist with soft tissue balancing throughout the full range of motion. The first purpose of the present study is to assess joint gap kinematics in UKA. Secondly, we attempted to compare the pattern in UKA with those in CR and PS TKA with the reduced PF joint and femoral component placement, which more closely reproduces post-operative joint alignment. Using this tensor, we assessed the intra-operative joint gap measurements of UKAs performed at 0, 10, 30, 45, 60, 90, 120 and 135° of flexion in 20 osteoarthritic patients. In addition, the kinematic pattern of UKA was compared with those of CR and PS TKA that were calculated as medial compartment gap from the previous series of this study.Backgrounds
Methods
Rapid increase of aged population has been one of major issue affecting national health care plan in Japan. In 2006, Japanese Orthopaedic Association proposed the clinical entity of musculoskeletal ambulation disorder symptom complex (MADS) to define the elderly population with high risk of fall and ambulatory disability caused by musculoskeletal disorders. Osteoarthritis of the knee is one of major cause of MADS. The number of patients with MADS underwent total knee arthroplasty (TKA) had been increased in Japan, and also expected to increase worldwide in the near future. The effectiveness of TKA for the patient with MADS has not been well evaluated. In the present study, we analyzed the early post-operative functional recovery after TKA using 2 simple performance tests to diagnose MADS. Fifty patients with varus type osteoarthritic knees implanted with posterior-stabilized (PS) TKAs were subjected to this study. There were 44 female and 6 male patients. The mean age of the patients was 71.6 years (range, 59 to 84 years). Patients were subjected to 2 functional performance tests which were essential tests for MADS diagnosis. Firstly, 3 meter timed up and go test (TUG) was used to evaluate ambulation. Secondary one leg standing time with open eyes was measured to assess balancing ability. 2 tests were performed pre-operatively, 2 weeks after surgery and at discharge (23.8 days po). MADS was defined to be diagnosed if TUG and one leg standing time was not less than 11 seconds and/or less than 15 seconds respectively. Each parameter was compared among at above mentioned three time points -using a repeated measured analysis of variance (p<0.05).Introduction
Material & Method
Appropriate intraoperative soft tissue balancing is recognized to be essential in total knee arthroplasty (TKA). However, it has been rarely reported whether intraoperative soft tissue balance reflects postoperative outcomes. In this study, we therefore assessed the relationship between the intra-operative soft tissue balance measurements and the post-operative stress radiographs at a minimum 1-year follow-up in cruciate-retaining (CR) TKA, and further analyzed the postoperative clinical outcome. The subjects were 25 patients diagnosed with osteoarthritis with varus deformity and underwent primary TKA. The mean age at surgery was 72.0 ± 7.5 years (range, 47–84 years). The Surgeries were performed with the tibia first gap technique using CR-TKA (e motion, B. Braun Aesculap) and the image-free navigation system (Orthopilot). We intraoperatively measured varus ligament balance (°, varus angle; VA) and joint component gap (mm, center gap; CG) at 10° and 90° knee flexion guided by the navigation system, with the patella reduced. At a minimum 1-year follow-up, post-operative coronal laxity at extension was assessed by varus and valgus stress radiographs of the knees with 1.5 kgf using a Telos SE arthrometer (Fa Telos) and that at flexion was assessed by epicondylar view radiographs of the knees with a 1.5-kg weight at the ankle. After calculating postoperative VA and CG from measurements of radiographs, measurements and preoperative and postoperative clinical outcome, such as Knee Society Clinical Rating System (Knee score; KSS, Functional score; KSFS) and postoperative knee flexion, were analyzed statistically using linear regression models and Pearson's correlation coefficient.Introduction
Methods
Although both accurate component placement and adequate soft tissue balance have been recognized as essential surgical principle in total knee arthroplasty (TKA), the influence of intra-operative soft tissue balance on the post-operative clinical results has not been well investigated. In the present study, newly developed TKA tensor was used to evaluate soft tissue balance quantitatively. We analyzed the influence of soft tissue balance on the post-operative knee extension after posterior-stabilized (PS) TKA. Fifty varus type osteoarthritic knees implanted with PS-TKAs were subjected to this study. All TKAs were performed using measured resection technique with anterior reference method. The thickness of resected bone fragments was measured. Following each bony resection and soft tissue releases, we measured soft tissue balance at extension and flexion of the knee using a newly developed offset type tensor. This tensor device enabled quantitative soft tissue balance measurement with femoral trial component in place and patello-femoral (PF) joint repaired (component gap evaluation) in addition to the conventional measurement between osteotomized surfaces (osteotomy gap evaluation). Soft tissue balance was evaluated by the center gap (mm) and ligament balance (°; positive in varus) applying joint distraction forces at 40 lbs (178 N). Active knee extension in spine position was measured by lateral X-ray at 4 weeks post-operatively. The effect of each parameter (soft tissue balance evaluations, thickness of polyethylene insert and resected bone) on the post-operative knee extension was evaluated using simple linear regression analysis. P<0.05 was considered statistically significant.Objective
Materials and Methods
In cruciate-retaining total knee arthroplasty (TKA), among many factors influencing post-operative outcome, increasing the tibial slope has been considered as one of the beneficial factors to gain deep flexion because of leading more consistent femoral rollback and avoiding direct impingement of the insert against the posterior femur. In contrast, whether increasing the tibial slope is useful or not is controversial in posterior-stabilized (PS) TKA, Under such recognition, accurate soft tissue balancing is also essential surgical intervention for acquisition of successful postoperative outcomes in TKA. In order to permit soft tissue balancing under more physiological conditions during TKAs, we developed an offset type tensor to obtain soft tissue balancing throughout the range of motion with reduced patello-femoral(PF) and aligned tibiofemoral joints and have reported the relationship between intra-operative soft tissue balance and flexion angles. In this study, we therefore assessed the relationship between intra-operative soft tissue balance assessed using the tensor and the tibial slope in PS TKA. Thirty patients aged with a mean 72.6 years were operated PS TKA(NexGen LPS-Flex, Zimmer, Inc. Warsaw, IN) for the varus type osteoarthritis. Following each bony resection and soft tissue release using measure resection technique, the tensor was fixed to the proximal tibia and femoral trial prosthesis was fitted. Assessment of the joint component gap (mm) and the ligament balance in varus (°)was carried out at 0, 10, 45, 90and 135degrees of knee flexion. The joint distraction force was set at 40lbs. Joint component gap change values during 10-0°,45-0°, 90-0°, 135-0° flexion angle were also calculated. The tibial slopes were measured by postoperative lateral radiograph. The correlation between the tibial slope and values of soft tissue balance were assessed using linear regression analysis.Introductions
Materials and methods
Achieving high flexion after total knee arthroplasty (TKA) is one of the most important clinical results, especially in eastern countries where the high flexion activities, such as kneeling and squatting, are part of the important lifestyle. Numerous studies have examined the kinematics after TKA. However, there are few numbers of studies which examined the kinematics during deep knee flexion activities. Therefore, in the present study, we report analysis of mobile-bearing TKA kinematics from extension to deep flexion kneeling using 2D-3D image matching technique. The subjects were 16 knees of 8 consecutive patients (all women, average age 75.9), who underwent primary mobile-bearing PS TKA (P.F.C. sigma RP-F: Depuy Orthopedics Inc., Warsaw, IN, USA) between February 2007 and May 2008. All cases were osteoarthritis with varus deformity. Postoperative radiographs were taken at the position of extension, half-squatting and deep flexion kneeling 3 month after the surgery, and the degrees of internal rotation of the tibial component was measured by 2D-3D image matching technique. Pre- and post-operative ROM was recorded. Then, we compared the absolute value and relative movement of tibial internal rotation between extension, half-squatting and deep flexion kneeling, and evaluated the correlation of the ROM and the internal rotation.Introduction
Materials and Methods
Accurate soft tissue balancing has been recognized as important as alignment of bony cut in total knee arthroplasty (TKA). In addition, using a tensor for TKA that is designed to facilitate soft tissue balance measurements throughout the range of motion with a reduced patello-femoral (PF) joint and femoral component in place, PF joint condition (everted or reduced) has been proved to have a significant effect for intra-operative soft tissue balance. On the other hand, effect of patellar height on intra-operative soft tissue balance has not been well addressed. Therefore, in the present study, we investigated the effect of patellar height by comparing intra-operative soft tissue balance of patella higher subjects (Insall-Salvati index>1) and patella lower subjects (Insall-Salvati indexâ‰/1). The subjects were 30 consecutive patients (2 men, 28 women), who underwent primary PS TKA (NexGen LPS-flex PS: Zimmer, Warsaw, IN, USA) between May 2003 and December 2006. All cases were osteoarthritis with varus deformity. Preoperative Insall-Salvati index (ISI) was measured and patients were divided into two groups; the patella higher group (ISIï1/4ž1: 18 knees average ISI was 1.12) and the patella lower group (ISIâ‰/1; 12 knees average ISI was 0.94). Component gap and ligament balance (varus angle) were measured using offset-type tensor with 40lb distraction force after osteotomy with the PF joint reduced and femoral trial in place at 0, 10, 45, 90, 135 degrees of knee flexion. Data of two groups were compared using unpaired t test.Introduction
Materials and methods
Total knee arthroplasty (TKA) with a computer-assisted navigation system has been developed to improve the accuracy of the alignment of osteotomies and implantations. One of the most important goals of TKA is to improve the flexion angle. Although accurate soft tissue balancing has been recognized as an essential surgical intervention influencing flexion angle, the direct relationship between post-operative flexion angle and intra-operative soft tissue balance during TKA, has little been clarified. In the present study, therefore, we focused on the relationship between them in cruciate-retaining (CR) TKA with a navigation system. The subjects were 30 consecutive patients (2 men, 28 women), who underwent primary CR TKA (B. Braun Aesculap, e-motion) between May 2006 and December 2009. TKAs were performed using a image-free navigation system (OrthoPilot; B. Braun Aesculap, Tuttlingen, Germany). All cases were osteoarthritis with varus deformity. Average patient age at the time of surgery was 74.0 years (range, 62-86 years). After all bony resections and soft tissue releases were completed appropriately using a navigation system with tibia-first gap technique, a tensor was fixed to the proximal tibia and the femoral trial was fitted. Using the tensor that is designed to facilitate soft tissue balance measurements throughout the range of motion with a reduced patello-femoral (PF) joint and femoral component in place, the joint component gap and ligament balance (varus angle) were measured after the PF joint reduced and femoral component in place (Fig.1). Assessments of joint component gap and ligament balance were carried out at 0°, 30°, 60°, 90°, 120° flexion angle, which were monitored by the navigation system. Joint component gap change values during 30°- 0°, 60°- 0°, 90°- 0°, 120°- 0° flexion angle were calculated. The correlation between post operative flexion angles and pre-operative flexion angle, intra-operative joint component gaps, joint component gap change values and ligament balances were assessed using linear regression analysis.Introduction
Materials and methods
Using a tensor for total knee arthroplasty (TKA) that is designed to facilitate soft tissue balance measurements with a reduced patello-femoral (PF) joint, we examined the influence of pre-operative deformity on intra-operative soft tissue balance during posterior-stabilized (PS) TKA. Joint component gap and varus angle were assessed at 0, 10, 45, 90 and 135° of flexion with femoral trial prosthesis placed and PF joint reduced in 60 varus type osteoarthritic patients. Joint gap measurement showed no significant difference regardless the amount of pre-operative varus alignment. With the procedures of soft tissue release avoiding joint line elevation, however, intra-operative varus angle with varus alignment of more than 20 degrees exhibited significant larger values compared to those with varus alignment of less than 20 degrees throughout the range of motion. Accordingly, we conclude that pre-operative severe varus deformity may have the risk for leaving post-operative varus soft tissue balance during PS TKA.
Recently, many researches of minimal incision surgery (MIS) total knee arthroplasty (TKA) have been reported, however very few of these contain clinical results. Regardless of this, MIS TKA is widely promoted as an improvement over traditional TKA. Although traditional TKA allows for excellent visualization, component orientation, fixation, and has been associated with remarkable long-term implant survival, many patients expect an extremely small incision, minimal or no pain and discomfort associated with their surgery, and certainly no increase in the complication rate. While there is some evidence that short term benefits may occur, there is concern that there may be an increase in complications with the use of MIS technique. We report here cases that malalignments in early phase were occurred after MIS TKAs. A consecutive series of MIS TKA for varus osteoarthritis undertaken by 2 surgeons at 2 centers during 2-year priod (2006–2007) was reviewed. During this interval, 50 MIS TKAs were performed. The mean age was 75.6 years (range 54 to 88 years). Cases for post-operatively infection were excluded. There were 2 cases that early failures due to varus sinking of tibial component were confirmed in early phase (7 and 3 months after primary surgery). We analyzed data between early failed cases and non-failed cases. Patients with early failure were younger, which showed a trend toward significance (p=0.11; failed; 66.5, non-failed; 75.9 years). There was no difference in amount of both medial and lateral side of distal femoral cut between early failed cases and non-failed cases. Proximal tibial cut was significantly larger in early failed cases compared with non-failed cases (p=0.01; failed; 16.5±4.5, nonfailed; 11.4±6.6). There was no difference in Femorotibial angle (FTA) after surgery between them. Substantial backgrounds of occurring early failure after MIS TKA are not still clarified, however, very early failure were occurred in patients, who had significant large cut of proximal tibia, in our experienced cases. MIS TKA may lead to varus imbalance due to increased amount of bony cut and decreased medial soft tissue release. Henceforth, the high prevalence of MIS failures occurring in early phase is disturbing, because of limited working space and warrants further investigation.
However, optimal duration for CFNB to decrease pain and accelerate rehabilitation program after TKA has not been addressed. We, therefore, compared three groups of patients which had different duration of CFNB (0, 2, and 5days) in this study.
Outcomes including visual analog scale (VAS) pain scores and range of motion (ROM) were compared at 1st, 3rd, 6th, 14th and 21th days after surgery. In addition, the postoperative date when patients could walk stably with parallel bar, walker, or T-cane were recorded and compared.
ROM did not show significant difference among the three groups over postoperative days 1st to 21st (P>
0.05), although groups with the CFNB showed greater ROM at all time points. The CFNB 5 days group obtained stable walking ability with T-cane earlier than other groups (P<
0.05). No patient had any side effect by having CFNB in this study.
We have developed a new tensor for total knee replacements which is designed to assist with soft-tissue balancing throughout the full range of movement with a reduced patellofemoral joint. Using this tensor in 40 patients with osteoarthritis we compared the intra-operative joint gap in cruciate-retaining and posterior-stabilised total knee replacements at 0°, 10°, 45°, 90° and 135° of flexion, with the patella both everted and reduced. While the measurement of the joint gap with a reduced patella in posterior-stabilised knees increased from extension to flexion, it remained constant for cruciate-retaining joints throughout a full range of movement. The joint gaps at deep knee flexion were significantly smaller for both types of prosthetic knee when the patellofemoral joint was reduced (p <
0.05).
We isolated multilineage mesenchymal progenitor cells from haematomas collected from fracture sites. After the haematoma was manually removed from the fracture site it was cut into strips and cultured. Homogenous fibroblastic adherent cells were obtained. Flow cytometry revealed that the adherent cells were consistently positive for mesenchymal stem-cell-related markers CD29, CD44, CD105 and CD166, and were negative for the haemopoietic markers CD14, CD34, CD45 and CD133 similar to bone-marrow-derived mesenchymal stem cells. In the presence of lineage-specific induction factors the adherent cells could differentiate Our results indicate that haematomas found at a fracture site contain multilineage mesenchymal progenitor cells and play an important role in bone healing. Our findings imply that to enhance healing the haematoma should not be removed from the fracture site during osteosynthesis.
We have investigated whether cells derived from haemarthrosis caused by injury to the anterior cruciate ligament could differentiate into the osteoblast lineage Our results suggest that the haemarthrosis induced by injury to the anterior cruciate ligament contains osteoprogenitor cells and is a potential alternative source for cell-based treatment in such injury.
We undertook 114 arthroscopic meniscal repairs in 111 patients and subsequently carried out second-look arthroscopy to confirm meniscal healing at a mean of 13 months after repair. Stable healing at the repaired site was seen in 90. Of these, however, 13 had another arthroscopy later for a further tear. The mean period between the repair and the observation of a repeat tear was 48 months. Of the 13 patients, 11 had returned to high activity levels (International Knee Documentation Committee level I or II) after the repair. An attempt should be made to preserve meniscal function by repairing tears, but even after arthroscopic confirmation of stable healing repaired menisci may tear again. The long-term rate of healing may not be as high as is currently reported. Second-look arthroscopy cannot predict late meniscal failure and may not be justified as a method of assessment for meniscal healing. Young patients engaged in arduous sporting activities should be reviewed regularly even after arthroscopic confirmation of healing.
