The objective of this study was to present the outcomes of rotational acetabular osteotomy (RAO) over a 30-year period for osteoarthritis (OA) secondary to dysplasia of the hip in pre- or early-stage OA. Between September 1987 and December 1994, we provided treatment to 47 patients (55 hips) with RAO for the management of pre- or early-stage OA due to developmental hip dysplasia. Of those, eight patients (11 hips) with pre-OA (follow-up rate 79%) and 27 patients (32 hips) with early-stage OA (follow-up rate 78%), totalling 35 patients (43 hips) (follow-up rate 78%), were available at a minimum of 28 years after surgery.Aims
Methods
MRI has been increasingly used as an outcome measure and proxy for healing and integration after ACL reconstruction (ACLR). Despite this, it has not yet been established what a steady state graft MRI appearance is. MRI and clinical outcome measures were prospectively taken at 1 and minimum 2 years after hamstring autograft ACLR. MRI graft signal was measured using novel reconstructions both parallel and perpendicular to the graft, with lower signal indicative of better healing and expressed as the signal intensity ratio (SIR), and tunnel apertures analysed.Abstract
Introduction
Methodology
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
Upright body posture is maintained with the alignment of the spine, pelvis, and lower extremities, and the muscle strength of the body trunk and lower extremities. Conversely, the posture is known to undergo changes with age, and muscle weakness of lower extremities and the restriction of knee extension in osteoarthritis of the knee (knee OA) have been considered to be associated with loss of natural lumbar lordosis and abnormal posture. As total knee arthroplasty (TKA) is aimed to correct malalignment of lower extremities and limited range of motion of knee, particularly in extension, we hypothesized that TKA positively affects the preoperative abnormal posture. To clarify this, the variation in the alignment of the spine, pelvis, and lower extremities before and after TKA was evaluated in this study. Patients suffering from primary knee OA who were scheduled to receive primary TKA were enrolled in this study. However, patients with arthritis secondary to another etiology, i.e. rheumatoid arthritis, trauma, or previous surgical interventions to the knee, were excluded. Moreover, patients who suffered from hip and ankle OA, cranial nerve diseases, or severe spinal deformity were also excluded. The sagittal vertical axis (SVA), the horizontal distance between the posterosuperior aspect of the S1 endplate surface and a vertical plumb line drawn from the center of the C7 vertebral body, is an important index of sagittal balance of the trunk. Thus, patients were classified into two groups based on the preoperative SVA with preoperative standing lateral digital radiographs: normal (< 40mm) and abnormal (≥ 40mm) groups. The variations in the sagittal alignment of the spine, pelvis and lower extremities were evaluated preoperatively, and at 1 and 3 months postoperatively. This study was approved by an institutional review board, and informed consent for participation was obtained from the patients.Introduction
Patients and methods
In order to restore the neutral limb alignment in total knee arthroplasty (TKA), surgical procedure usually starts with removing osteophytes in varus osteoarthritic knees. However, there are no reports in the literature regarding the exact influence of osteophyte removal on alignment correction. The purpose of this study was to define the influence of osteophyte removal alone on limb alignment correction in the coronal plane in TKA for varus knee. Twenty-eight medial osteoarthritic knees with varus malalignment scheduled for TKA were included in this study. After registration of a navigation system, each knee was tested at maximum extension, and at 30, 40 and 60 degrees of flexion before and after osteophyte removal. External loads of 10 N-m valgus torque at each angle and in both states were applied. Subsequently, the widths of the resected osteophytes were measured.Background
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 posterior slope of the tibial component in total knee arthroplasty (TKA) has been reported to vary widely even with computer assisted surgery. In the present study, we analyzed the influence of posterior tibial slope on one-year postoperative clinical outcome after posterior-stabilized (PS) -TKA to find out the optimal posterior slope of tibial component. Seventy-three patients with varus type osteoarthritic (OA) knees underwent PS-TKA (Persona PSR) were involved in this study. The mean age was 76.6 years old and preoperative HKA angle was 14.3 degrees in varus. Tibial bone cut was performed using standard extra-medullary guide with 7 degrees of posterior slope. The tibial slopes were radiographically measured by post-operative lateral radiograph with posterior inclination in plus value. The angle between the perpendicular line of the proximal fibular shaft axis and the line drawn along the superior margin of the proximal tibia represented the tibial slope angle. We assessed one-year postoperative clinical outcomes including active range of motion (ROM), patient satisfaction and symptoms scores using 2011 Knee Society Score (2011 KSS). The influences of posterior tibial slope on one-year postoperative parameters were analyzed using simple linear regression analysis (p<0.05).Background
Materials and Method
The hip hemiarthroplasty in posterior approach is a common surgical procedure at the femoral neck fractures in the elderly patients. However, the postoperative hip precautions to avoid the risk of dislocations are impeditive for early recovery after surgery. We used MIS posterior approach lately known as conjoined tendon preserving posterior (CPP) approach, considering its enhancement of joint stability, and examined the intraoperative and postoperative complications, retrospectively. We performed hip hemiarthroplasty using CPP approach in 30 patients, and hip hemiarthroplasty using conventional posterior approach in 30 patients, and both group using lateral position with the conventional posterior skin incision. The conjoined tendon (periformis, obturator internus, and superior/inferior gemellus tendon) was preserved and the obturator externus tendon was incised in CPP approach without any hip precautions postoperatively. The conjoined tendon was incised in conventional approach using hip abduction pillow postoperatively.Introduction
Methods
Modified gap technique has been reported to be beneficial for the intraoperative soft tissue balancing in posterior-stabilized (PS) -TKA. We have found intraoperative ligament balance changed depending on joint distraction force, which might be controlled according to surgeons' fells. We have developed a new surgical concept named as “medial preserving gap technique (MPGT)” to preserve medial knee stability and provide quantitative surgical technique according to soft tissue balance measurement using a tensor device. The purpose of this study was to compare 3-years postoperative knee stability after PS-TKA in varus type osteoarthritic (OA) knees between MPGT and measured resection technique (MRT). The subjects were 94 patients underwent primary unilateral PS-TKA for varus type OA knees. The surgical technique was MPGT in 47 patients and MRT in 47 patients. An originally developed off-set type tensor device was used to evaluate intraoperative soft tissue balance. In MPGT, medial release was limited until the spacer block corresponding to the bone thickness from proximal lateral tibial plateau could be easily inserted. 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 resection. The knee stabilities at extension and flexion were assessed by stress radiographies at 1 and 3 years after TKA; varus-valgus stress test at extension and stress epicondylar view at flexion. We measured medial and lateral joint openings (MJO, LJO) at both knee extension and flexion. MJOs and LJOs at 2 time periods were compared in each group using paired t-test. Each joint opening distance was compared between 2 groups using unpaired t-test. The significance level was set as P < 0.05.Introduction
Material & Method
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
A femoral rotational alignment is one of the essential factors, affecting the postoperative knee balance and patellofemoral tracking in total knee arthroplasty (TKA). To obtain an adequate alignment, the femoral component must be implanted parallel to the surgical epicondylar axis (SEA). We have developed “a superimposable Computed Tomography (CT) scan-based template”, in which the SEA is drawn on a distal femoral cross section of the CT image at the assumed bone resection level, to determine the precise SEA. Therefore, the objective of this study was to evaluate the accuracy of the rotational alignment of the femoral component positioned with the superimposed template in TKA. Twenty-six consecutive TKA patients, including 4 females with bilateral TKAs were enrolled. To prepare a template, all knees received CT scans with a 2.5 mm slice thickness preoperatively. Serial three slices of the CT images, in which the medial epicondyle and/or lateral epicondyle were visible, were selected. Then, these images were merged into a single image onto which the SEA was drawn. Thereafter, another serial two CT images, which were taken at approximately 9 mm proximal from the femoral condyles, were also selected, and the earlier drawn SEA was traced onto each of these pictures. These pictures with the SEA were then printed out onto transparent sheets to be used as potential “templates” (Fig. 1-a). In the TKA, the distal femur was resected with the modified measured resection technique. Then, one template, whichever of the two potential templates, was closer to the actual shape, was selected and its SEA was duplicated onto the distal femoral surface (Fig. 1-b). Following that, the distal femur was resected parallel to this SEA. The rotational alignment of the femoral component was evaluated with CT scan postoperatively. For convention, an external rotation of the femoral component from the SEA was given a positive numerical value, and an internal rotation was given a negative numerical value.Introduction
Patients and 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
In order to achieve good clinical results in TKA, soft tissue balance is important. Soft tissue balance is closely related to knee kinematics which affects clinical results. Modified gap balancing technique is one of the standard techniques for posterior stabilized (PS) TKA. On the other hand, appropriate load for the measurement of gap balance has not been established. The purpose of the present study is to measure the mechanical properties of soft tissue structure of knee sleeve in flexion and extension during PS TKA using newly developed balancer. The understanding of the mechanical properties is crucial. In particular if these properties are used as input for surgical procedures, standard technique for many surgeons will be established. Medial compartmental osteoarthrosis (OA) patients (13 female and 7 male) were evaluated. Average age, BMI, and Varus deformity were 72.1 years, 26.9, and 12 degrees, respectively. The newly developed center paddle balancer consists of a built-in spring (Fig. 1). Figure 2 shows the sequence of surgery and measurements. In the surgery, we measured the balance (degrees in Figure 1, A) and distance (mm in Figure 1, B) in extension with a load (Figure 1,C) at transition zone of toe region to linear region. Then, applying the load until flexion gap was the same as that in extension with a patella reduction, we measured the femoral component rotation from the balancer (degrees in Figure 1, A). The anterior and posterior femoral cuts were performed according to measured femoral component rotation which angle is parallel to tibial cut surface.Introduction
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
For restoration of neutral limb alignment in Total Knee Arthroplasty (TKA), we usually start by removing osteophytes in varus osteoarthritic knees. However, we have found no reports in the literature regarding research on the exact influence of osteophyte removal on angle correction. The purpose of this study was to define the influence of osteophyte removal on limb alignment correction in the coronal plane in TKA. Nine patients with varus malalignment that were scheduled for TKA were included in this study. Only patients with degenerative osteoarthritis were considered. After registration of a navigation system, each knee was tested at maximum extension, and 30 and 60 degrees of flexion before and after osteophyte removal. The same examiner applied all external loads of 10 N-m valgus torque at each angle and in both states. Subsequently, the widths of the osteophytes were measured. All data were analyzed statistically using paired t-test and correlation coefficient. A significant difference was determined to be present for P < .05.Introduction
Materials and Methods
Total knee arthroplasty (TKA) is the highly developed procedure for sever osteoarthritic knee, in which there are two major concepts; Cruciate Retaining design (CR) and Posterior Stabilized design (PS). The femoral roll back movement is enforced with the post-cam mechanism in the PS, however, this structure associates with the complications, i.e. wear and dislocation. The CR has been developed to obtain the knee stability with native posterior cruciate ligament (PCL) in TKA. However, the preservation of the PCL can limit knee exposure and increase the technical challenge of surgery. We hypothesized that the knee exposure was easily achieved after the PCL was released, however, the PCL was repaired and the posterior stability was re-established after the TKA with time if it was released subperiostealy. The objective of this study was to evaluate the varying of the posterior stability after the PCL-released CR TKA.Background
Objective
Many factors can influence post-operative kinematics after total knee arthroplasty (TKA). These factors include intraoperative surgical conditions such as ligament release or quantity of bone resection as well as differences in implant design. Release of the medial collateral ligament (MCL) is commonly performed to allow correction of varus knee. Precise biomechanical knowledge of the individual components of the MCL is critical for proper MCL release during TKA. The purpose of this study was to define the influences of the deep medial collateral ligament (dMCL) and the posterior oblique ligament (POL) on valgus and rotatory stability in TKA. This study used six fresh-frozen cadaveric knees with intact cruciate ligaments. All TKA procedures were performed by the same surgeon using CR-TKA with a CT-free navigation system. Each knee was tested at 0°, 20°, 30°, 60°, and 90° of flexion. One sequential sectioning sequence was performed on each knee, beginning with an intact knee (S0), and thereafter femoral arthroplasty only (S1), tibial arthroplasty (S2), release of the dMCL (S3), and finally, release of the POL (S4). The same examiner applied all external load of 10 N-m valgus and a 5 N-m internal and external rotation torque at each flexion angle for the each cutting state. All data were analyzed statistically using one-way ANOVA and we investigated the correlation between the medial gap and the rotation angle. A significant difference was determined to be present for P < .05.Introduction
Materials and Methods
This is a minimum 15 year follow up of a cohort of 58 patients (30 men and 28 women) who underwent 62 non-cemented THR between 1998–2000 (54 unilateral, 4 bilateral), in whom an off-the-shelf “lateral flare” femoral component was implanted. These surgeries were performed by a single surgeon and have been followed continuously by that same surgeon. The mean age at the time of surgery was 60.4 yrs (52–74). There were no exclusions for osteoporosis or type “C” femoral geometry. Although some patients have deceased during these 15 years, there have been no stem failures, revisions or impending stem revisions at the time of follow up or at the time of death in those who have passed. Two patients have undergone revision of their acetabular liner for poly wear. There have been no complaints of thigh pain; and like the results seen in other series employing this stem design, there has been no evidence of bone loss due to stress shielding or subsidence of the femoral component in any of these patients. This mid-term follow up re-affirms the dynamic tension band model of hip biomechanics, upon which the “lateral flare” design is predicated. This model predicts that the proximal lateral femur can experience compression during the gait cycle and as such can be utilized as an additional base of support upon which the femoral component can rest. Rather than relying upon a traditional “press fit” technique to achieve initial implant stability, a technique which is highly dependent upon femoral geometry, bone quality and may risk fracture on implant seating, the “lateral flare” design permits a gentler, safer and more physiologic means of achieving initial implant stability necessary for osseous integration to occur. This alterantive terchnique has been termed a “rest fit”.
