This study aimed to evaluate the association between the sagittal alignment of the femoral component in total knee arthroplasty (TKA) and new Knee Society Score (2011KSS), under the hypothesis that outliers such as the excessive extended or flexed femoral component were related to worse clinical outcomes. A group of 156 knees (134 F:22 M) in 133 patients with a mean age 75.8 years (SD 6.4) who underwent TKA with the cruciate-substituting Bi-Surface Knee prosthesis were retrospectively enrolled. On lateral radiographs, γ angle (the angle between the distal femoral axis and the line perpendicular to the distal rear surface of the femoral component) was measured, and the patients were divided into four groups according to the γ angle. The 2011KSSs among groups were compared using the Kruskal-Wallis test. A secondary regression analysis was used to investigate the association between the 2011KSS and γ angle.Aims
Methods
It has been reported that the rate of complications around the patella after Total Knee Arthroplasty(TKA) is 1–12%, and the patella dislocation is the most common one. We will report a case that had the patella dislocation after TKA caused by malrotation of the components.INTRODUCTION
PURPOSE
The purpose of this study is to evaluate stiff knees which have a preoperative arc of motion (AOM) < 65 degrees and maximum flexion < 90 degrees under anesthesia for primary TKA. We prospectively evaluated 25 knees, 20 patients, the follow up period was 5±3 years, OA 13, RA 10 and traumatic OA 2 knees. All case were medial para-patella approaches and snip was added in one knee operation, 23 PS-type and 2 constrain-type TKAs.Purpose
Material and Methods
Appropriate soft tissue balance is an important factor for postoperative function and long survival of total knee arthroplasty(TKA). Soft tissue balance is affected by ligament release, osteophyte removal, order of soft tissue release, cutting angle of tibial surface and rotational alignment of femoral components. The purpose of this study is to know the characteristics of soft tissue balance in ACL deficient osteoarthritis(OA) knee and warning points during procedures for TKA. We evaluated 139 knees, underwent TKA (NexGen LPS-Flex, fixed surface, Zimmer) by one surgeon (S.A.) for OA. All procedures were performed through a medial parapatellar approach. There were 49 ACL deficient knees. A balanced gap technique was used in 26 ACL deficient knees, and anatomical measured technique based on pre-operative CT was used in 23 ACL deficient knees. To compare flexion-extension gaps and medial- lateral balance during operations between the two techniques, we measured each using an original two paddles tensor (figure 1) at 20lb, 30lb and 40lb, for each knee at a 0 degree extension and 90 degree flexion. We measured bone gaps after removal of all osteophytes and cutting of the tibial surface, then we measured component gaps after insertion of femoral components. Statistical analysis was performed by t-test with significant difference defined as P<0.05.INTRODUCION
METHODS
Unicompartmental knee arthroplasty (UKA) is one surgical option for treating symptomatic medial osteoarthritis. Clinical studies have shown the functional benefits of UKA; however, the optimal alignment of the tibial component is still debated. The purpose of this study was to evaluate the effects of tibial coronal and sagittal plane alignment in UKA on knee kinematics and cruciate ligament tension, using a musculoskeletal computer simulation. The tibial component was first aligned perpendicular to the mechanical axis of the tibia, with a 7° posterior slope (basic model). Subsequently, coronal and sagittal plane alignments were changed in a simulation programme. Kinematics and cruciate ligament tensions were simulated during weight-bearing deep knee bend and gait motions. Translation was defined as the distance between the most medial and the most lateral femoral positions throughout the cycle.Objectives
Methods
The results of modified gap balancing and measured resection technique have been still controversial. We compared PS-type TKAs for osteoarthritis performed using the modified gap technique and the measured resection to determine if either technique provides superior clinical results. The modified gap technique was used in 85 knees, and the measured technique using preoperative CT was used in 70 knees. To compare intra-operative soft tissue balance, bone gap and component gap were measured using original two paddle tensor (20,30,40lb) at 0 degree extension and 90 degrees flexion. To assess the post-operative patella congruency and soft tissue balance, we measured patella tilt, condylar twist angle (CTA) and condylar lift-off angle (LOA) in radiographs. Finally, we evaluated postoperative clinical result (1–5 years) KOOS. Statistical analysis was used by StatView.INTRODUCTION
METHODS
All animal experiments were performed on IACUC approved protocols. USA300LAC (MRSA) and RP62A(INTRODUCTION
METHODS
Little biomechanical information is available about kinematically aligned (KA) total knee arthroplasty (TKA). The purpose of this study was to simulate the kinematics and kinetics after KA TKA and mechanically aligned (MA) TKA with four different limb alignments. Bone models were constructed from one volunteer (normal) and three patients with three different knee deformities (slight, moderate and severe varus). A dynamic musculoskeletal modelling system was used to analyse the kinematics and the tibiofemoral contact force. The contact stress on the tibial insert, and the stress to the resection surface and medial tibial cortex were examined by using finite element analysis.Objectives
Materials and Methods
The systematic effects of joint replacement in rheumatoid arthritis (RA) patients are that inflamed synovium and pathological articular cartilage has dissipated. Expectations of total knee arthroplasty (TKA) are reduction of inflammatory cytokines, decreased disease activity and improvement of drug efficacy and ADL. Remission of rheumatoid arthritis is defined as having a Disease Activity Score DAS28 (ESR) of less than 2.6 and Health Assessment Questionnaire (HAQ) – Disability Index, less than 0.5. We investigated whether TKA could reduce disease activity and improve ADL, and subsequent remission levels of DAS and HAQ or not.Introduction
Purpose
Total elbow arthroplasty (TEA) has become an established procedure in the treatment of patients with rheumatoid arthritis (RA). However, there is little information on whether limited extension of the elbow affects clinical outcome scores after TEA and what causes the limited extension. We retrospectively analyzed fifty-four cases of primary TEA in patients with RA. There were seven men and thirty-nine women with a mean age of 63.6 years (range, thirty to eighty years). Thirty-seven of Coonrad-Morrey and seventeen of Discovery prostheses were used. The mean length of follow-up was 7.1 ± 4.0 years (range 2.0–14.6 years). Mayo Elbow Performing Score (MEPS) and radiological measurements were recorded. Anteroposterior and lateral radiographs were assessed before and after the operation and at the latest follow-up. Widening of the joint space was calculated by subtracting the length measured on the postoperative radiograph from that on the preoperative radiograph.Background
Methods
Malrotation of a femoral component is a cause of patellofemoral maltracking after total knee arthroplasty (TKA). We have developed a balanced gap technique in posterior stabilized total knee arthroplasty (PS-TKA) using an original tensor instrument. One of characteristics of this instrument is the ability to measure gaps even if there is a bone defect, because it has two paddles, and we can attach block augmentations. In addition it can measure the gap after a reduction of the patella with an offset mechanism. In the balanced gap technique, the femoral component rotation is decided by a tibial cut surface and ligaments balance using the tensor device. This study investigated retrospectively whether rotational alignment of femoral component rotation influenced patellofemoral joint congruency in PS- TKA. We evaluated the radiographs of 52 knees of 42 patients, who underwent TKA (NexGen LPS-Flex, fixed surface, Zimmer) by one surgeon (S.A.) for osteoarthritis or rheumatoid arthritis. All procedures were performed through a medial parapatellar approach and a balanced gap technique using a developed versatile tensor device. We measured lateral patella tilt and lateral patella shift at post-op. 6 months. To assess the rotational alignment of femoral component rotation, condylar twist angle (CTA) was measured, and to assess the postoperative flexion gap balance, a condylar lift-off angle (LOA) was measured using the epicondylar view radiographs.Introduction
Material and Methods
Malrotation of the tibial component would lead to various complications after total knee arthroplasty (TKA) such as improper joint kinematics, patellofemoral instability, or excessive wear of polyethylene. However, despite reports of internal rotation of the tibial component being associated with more severe pain or stiffness than external rotation, the biomechanical reasons remain largely unknown. In this study, we used a musculoskeletal computer model to simulate a squat (0°–130°–0° flexion) and analyzed the effects of malrotated tibial component on lateral and medial collateral ligament (LCL and MCL) tensions, tibiofemoral and patellofemoral contact stresses, during the weight-bearing deep knee flexion. A musculoskeletal model, replicating the dynamic quadriceps-driven weight-bearing knee flexion in previous cadaver studies, was simulated with a posterior cruciate-retaining TKA. The model included tibiofemoral and patellofemoral contact, passive soft tissue and active muscle elements. The soft tissues were modeled as nonlinear springs using previously reported stiffness parameters, and the bony attachments were also scaled to some cadaver reports. The neutral rotational alignment of the femoral and tibial components was aligned according to the femoral epicondylar axis and the tibial anteroposterior axis, respectively. Knee kinematics and ligament tensions were computed during a squat for malrotated conditions of the tibial component. The tibial rotational alignments were changed from 15° external rotation to 15° internal rotation in 5° increments. The MCL and LCL tensions, the tibiofemoral and patellofemoral contact stresses were compared among the knees with different rotational alignment.Introduction
Materials and Methods
Total knee arthroplasty (TKA) is one of the most successful surgeries with respect to relieving pain and restoring function of the knee. However, some studies have reported that patients are not always satisfied with their results after TKA. The aim of this study was to determine which factors contribute to patient's satisfaction after TKA. We evaluated 69 patients who had undergone 76 primary TKAs between March 2012 and June 2013, and assessed patient- and physician- reported scores using the 2011 Knee Society Scoring System and clinical variables before and after TKAs. We determined the correlation between patient satisfaction and clinical variables.Purpose
Methods
In articular cartilage defects, chemokines are upregulated and potentially induce the migration of bone marrow cells to accelerate the healing processes. The treatment of damaged articular cartilages is one of the most challenging issues in sports medicine and in aging societies. In the microfracture technique for the treatment of articular cartilage defects, bone marrow cells are assumed to migrate from the bone marrow. Bone marrow cells are well-known for playing crucial roles in the healing processes, but how they can migrate from underlying bone marrow remains to be investigated. We have previously shown that SDF-1, one of chemokines, play crucial roles in the recruitment of mesenchymal stem cells in bone healing processes, and the induction of SDF-1 can induce a successful bone repair. If the migration can be stimulated by any means in the cartilage defects, a better result can be expected. The aim of this study was to elucidate the mechanisms of the migration of bone marrow cells and which factors contribute to the processes.Summary Statement
Introduction
MCP-1/ CCR2 axis at the early phase plays a pivotal role in the fracture healing. Inflammation plays a pivotal role in fracture healing. Among them, chemokines play key roles in inflammation. Monocyte chemotactic protein-1 (MCP-1), via its receptor C-C chemokine receptor 2 (CCR2), acts as a potent chemoattractant for various cells to promote migration from circulation to inflammation site. Thus, the importance of MCP-1/CCR2 axis in fracture healing has been suggested. However, the involvement of MCP-1/CCR2 axis tofracture site is not fully elucidated. PCR Array: The expression of MCP-1 and MCP-3 had increased on day 2 than 0 or 7 in the rib fracture healing. Immunohistochemistry Staining: To verify the localization of MCP-1 expression, we examined the Wild type (WT)-mouse rib fracture healing. We observed high expression of MCP-1 and MCP-3 at the periosteum and the endosteum on post-fracture day 3. Summary Statement
Results
Modular femoral stems of Total Hip Arthroplasty (THA) have been designed to fit the metaphysis and diaphysis separately. Clinical results with modular femoral stems are reported to be satisfactory, but there exists several concerns with modular implant connections, including fretting corrosion, fracture of implant, and dissociation the stem from the proximal sleeve. Recently, we have become aware of another potential consequence of the modular design: sleeve deformation secondary to forces encountered during insertion. In our patients, we noted that the stems would not fully seat in the machined taper of the sleeve, indicating that some type deformation to the sleeve had occurred. We began an in vivo study to characterize this phenomenon. The objectives of this study were (1) Does deformation occur by impacting the sleeve into the metaphysis? (2) If so, quantify the sleeve deformation in hip arthroplasty patients. One man and 7 women undergoing primary THA were enrolled. This project was approved by IRB. This modular system (4-U CLS; Nakashima Medical Co., Japan) consists of a metaphyseal sleeve that connects with the diaphyseal stem via a Morse taper. The sleeve was impacted into the metaphysis first, followed by the stem. A custom taper gauge for each size of sleeve (Figure 1A) was inserted into the sleeve before and after impacting the sleeve into the metaphysis, and the distance between the top of the sleeve and the top of the gauge was measured using a caliper (* in Figure 1B). Deformation was defined as the difference in distance between the before and the after impacted dimensions. Preoperative femoral morphology, assessed using Dorr classification system, was type A in 2 hips, type B in 5 hips, and type C in 1 hip.INTRODUCTION:
MATERIALS AND METHODS:
The assumption that symmetric extension-flexion gaps improve the femoral condyle lift-off phenomenon and the patellofemoral joint congruity in total knee arthroplasty (TKA) is now widely accepted. For tease reasons, the balanced gap technique has been developed. However, the management of soft tissue balancing during surgery remains difficult and much is left to the surgeon's feel and experience. Furthermore, little is known about the differences of the soft-tissue stiffness (STS) of medial and lateral compartment in extension and flexion in the both cruciate ligaments sacrificed knee. It has a deep connection with the achievement of appropriate gaps operated according to the balanced gap technique. Therefore, the purpose of this study was to analyze the STS of individual compartment in vivo. The subjects presented 100 osteoarthritic knees with varus deformity underwent primary posterior stabilized (PS) – TKA (NexGen LPS-flex, Zimmer, Warsaw, USA). All subjects completed written informed consent. The patient population was composed of 14 men and 68 women with a mean age of 74.5 ± 7.5 years. The average height, weight, BMI, weight-bearing femorotibial mechanical angle (FTMA), the patella height (T/P ratio), extension and flexion angle of the knee under anesthesia were 151.9 ± 7.8 cm, 62.1 ± 9.4 kg, 26.9 ± 3.7 kg/m2, 167.7 ± 5.6 °, 0.91 ± 0.15 °, −12.0 ± 6.7° and 129.4 ± 13.8°, respectively. After finishing osteotomy and soft tissue balancing, the femoral trial prosthesis was fitted with patello-femoral joint reduction. Then, the medial and lateral compartment gaps (CG) were measured at various distraction forces (89–178 N) using a newly developed versatile tensor device at full extension and 90° flexion positioning, respectively. (Fig. 1) The STS (N/mm) was calculated from a load displacement curve generated by the intra-operative CG data and joint distraction force. Comparisons were made by Wilcoxon signed-ranks test. Correlations were analyzed with Pearson's correlation coefficient. Predictive variables were analyzed with Stepwise regression. A value of p < 0.05 was considered significant.Introduction:
Materials and Methods:
Conventional understanding of knee kinematics suggests that the femoral component should be rotationally aligned parallel to the surgical epicondylar axis (SEA). In contrast, the balanced gap technique suggests the knee be balanced in extension and flexion to achieve proper kinematics and stability of the knee without reference to fixed bony landmarks. To investigate the functional flexion-extension axis (FFEA) when a balanced gap technique was used in the posterior-stabilized total knee arthroplasty (PS-TKA), the relationships between rotational alignment of the femoral component to the postoperative flexion gap balance and to the tibial mechanical axis were evaluated radiographically. In this prospective study, 63 consecutive knees in 50 patients were included with medial osteoarthritis undergoing a primary PS-TKA (NexGen LPS-Flex, fixed surface, Zimmer; Warsaw, USA). All subjects completed written informed consent. The patient population was composed of 8 men and 42 women with a mean age of 73.0 ± 7.7 years. The average height, weight, BMI, weight-bearing femorotibial mechanical angle (FTMA), condylar twist angle (CTA), and the patella height (T/P ratio) were 150.9 ± 7.2 cm, 62.3 ± 10.1 kg, 27.3 ± 4.0 kg/m2, 167.8 ± 5.5°, 5.9 ± 1.6° and 0.94 ± 0.15, respectively. All procedures were performed through a medial parapatellar approach and a balanced gap technique used a newly developed versatile tensor device. Pre- and post-operatively, the CTA was evaluated using computed tomography (CT). To assess the postoperative flexion gap balance, a condylar lift-off angle (LOA) was evaluated using the epicondylar view radiographs. The FTMA and coronal alignment of the tibial component in reference to the tibial mechanical axis (angle β) were evaluated using plain AP radiography. The FFEA (angle θ) of the knee was calculated as the following; (angle β) + (post-operative CTA) – (LOA). Correlations were analyzed with Pearson's correlation coefficient. Predictive variables were analyzed utilizing Stepwise regression. A value of p < 0.05 was considered significant.Introduction:
Materials and Methods:
Malrotation of the femoral component is a cause of patellofemoral maltracking after total knee arthroplasty. We have developed a balanced gap technique in posterior stabilized total knee arthroplasty using an original instrument. Patellar instability is associated with an increased the tibial tubercle and the center of the groove (TT-TG) distance > 20 mm, and TT-TG is regarded as one index of a factor influencing congruity. To assess the influence on a patellofemoral joint by a modified gap technique, the purpose of this study is to compare the TT-TG distance before surgery and after total knee arthroplasty. We explored the 30 knees, 25 patients (4 male and 21 female), who underwent total knee arthroplasties (NexGen LPS-Flex, fixed surface, Zimmer; Warsaw, USA) for osteoarthritis or rheumatoid arthritis. All procedures were performed through a medial parapatellar approach and a balanced gap technique used a developed versatile tensor device. We compared the preoperative and postoperative CT at a knee flexion angle of 30 degrees. To assess the force vector of the extensor mechanism, TT-TG distance and the proximal-distal distance between the entrance of the tracheal groove and the tibial tubercle (ET-TT distance) were measured in CT. The relation of both distances (TT-TG index) that divided TT-TG in ET-TT was calculated, because the TT-TG distance was affected by the individual knee size. Three dimensional Q-angle (θ) was also calculated using TT-TG distance and ET-TT distance, sinθ = TT-TG distance/ET-TT distance. (Figure 1)Introduction
Material and Methods
It is said that the mechanical stress is a main factor to advance degenerative osteoarthritis. Therefore, to keep the joint stability is very important to minimize mechanical stress. Methods to evaluate bone-related factor are almost established, especially in hip dysplasia. On the other hand, it is unclear how much each soft tissue contribute to the joint stability. In this study we evaluated the soft tissue contribution for hip joint stability by distraction testing using MTS machine. We used seven fresh frozen hips from four donors, whose race was all western and reason of death was not related to hip disease in all cases. Average age of them at death was 83 years old. Mean average weight and height were each 52 kg and 162 cm. We retrieved hemi pelvis and proximal femur which kept hip joint intact. We removed all other soft tissue except iliofemoral ligament, pubofemoral ligament, ischiofemoral ligament and capsule. The hemi-pelvis mounted on angular-changeable fixator and the femur fixed to MTS machine (Figure 1). XY sliding table was used to minimize the horizontal direction stress during distraction. MTS machine was set to pull the femur parallel to its shaft by 0.4 mm/sec velocity against pelvis after 10N compression and to keep 5 mm distance for 5 seconds. We measured the force at 1 mm, 3 mm, 5 mm distraction. In case the joint was dislocated, the maximum force just before dislocation was recorded. The specimen was changed its posture as neutral (flexion0° abduction0° external rotation0°), flexion (flexion60° abduction0° external rotation0°), abduction (flexion0° abduction30° external rotation0°) and extension (extension20° abduction0° external rotation0°). Each position was measured in six sequential conditions, which are normal, Incised iliofemoral ligament, Circumferentially incised capsule, resected capsule, labral radial tear and resected labrum. After measurement joint surface was observed to evaluate the joint condition.[Introduction]
[Materials & Methods]
The assumption that symmetric extension-flexion gaps improve the femoral condyle lift-off phenomenon and the patellofemoral joint congruity in total knee arthroplasty (TKA) is now widely accepted. Conventional understanding of knee kinematics suggests that the femoral component should be rotationally aligned parallel to the surgical epicondylar axis (SEA). On the other hand, the theory of the balanced gap technique suggests the knee be balanced in extension and flexion to achieve proper kinematics and stability of the knee without reference to fixed bony landmarks. The purpose of our study was to evaluate the relationship between rotation alignment of the femoral component and postoperative flexion gap balance, and the femoral rotational alignment in relation to the tibial mechanical axis in patients when implanted using a balanced gap technique. The subjects presented 53 consecutive osteoarthritic (OA) varus knees underwent primary Posterior-Stabilised (PS) -TKA (NexGen LPS-flex, Zimmer). All subjects completed written informed consent. The patient population was composed of 7 men and 35 women with a mean age of 72.5 ± 8.3 years. The average height, weight, BMI, weight-bearing FTA, and the patella height (Insall-Salvati ratio: T/P ratio) were 151.7 ± 7.7 cm, 62.6 ± 11.8 kg, 27.2 ± 4.5, 184.9 ± 5.9° and 0.93 ± 0.14 respectively. All procedures were performed through a medial parapatellar approach and a balanced gap technique used a newly developed versatile tensor device which can measure the medial and lateral gaps individually and make use of the balanced gap technique guide with patellofemoral joint reduction, which had been introduced in 56th ORS 2010. Pre- and post-operatively, a condylar twist angle (CTA) was evaluated using computed tomography (CT). To assess the postoperative flexion gap balance, a condylar lift-off angle (LOA) was evaluated using the epicondylar view radiographs by adding a 1.5 kg weight at the ankle. Coronal alignment of the tibial component in reference to the tibial mechanical axis (angle θ) was evaluated using plain AP radiography. Data were expressed as mean ± SD and analysed with Stat View version 5.0.Introduction
Materials and Methods
Although Total elbow arthroplasty (TEA) generally provides favorable clinical outcomes, its complications have been reported with high rate compared with other joints. Previously, we used the Bryan & Morrey approach in TEA, which included separating the triceps muscle subperiosteally from the olecranon; however, since 2008, in order to prevent skin trouble and deficiency of the triceps, we performed TEA by MISTEA method, which required no removal of the subcutaneous tissue in the region of the olecranon and no release or stripping of the triceps tendon. The purpose of this study was to examine the utility of the MISTEA method by evaluating and comparing muscle strength and complications by using both the Bryan & Morrey approach and MISTEA method.Introduction
Objectives
In recently, Reverse shoulder arthroplasty (RSA) in patients with irreparable rotator cuff tear has been worldwidely performed. Many studies on RSA reported a good improvement in flexion of the sholulder, however, no improvement in external rotation (ER)and internal rotation motion (IR). Additionally, RSA has some risks to perform especially in younger patients, because high rates of complications such as deltoid stretching and loosening, infection, neurologic injury, dislocation, acromial fracture, and breakage of the prosthesis after long-term use were reported. Favard et al noted a 72% survival with a Constant-Murley score of <30 at 10 years with a marked break occurring at 8 years. Boileau et al noted caution is required, as such patients are often younger, and informed consent must obviously cover the high complication rate in this group, as well as the unknown longer-term outcome. Its use should be limited to elderly patients, arguably those aged over 70 years, with poor function and severe pain related to cuff deficiency. We developed a novel strategy in 2001, in which we used the humeral head to close the cuff defect and move the center of rotation medially and distally to increase the lever arm of the deltoid muscle. The aim of this study was to investigate clinical outcome of our strategy for younger patients with an irreparable rotator cuff tear.Introduction
Aim
Achieving high flexion after total knee arthroplasty is very important for patients in Asian countries where deep flexion activities are an important part of daily life. The Bi-Surface Total Knee System (Japan Medical Material, Kyoto, Japan), which has a unique ball-and-socket mechanism in the mid-posterior portion of the femoral and tibial components, was designed to improve deep knee flexion and long-term durability after total knee arthroplasty (Figure 1). The purpose of this study was to determine the in vivo three dimensional kinematics of Bi-Surface Total Knee System in order to evaluate and analyze the performance of this system with other conventional TKA designs currently available in the market today. Three dimensional kinematics were evaluated during a weight-bearing deep knee bend activity using fluoroscopy and a 2D-to-3D registration technique for 66 TKA. Each knee was analyzed to determine femorotibial kinematics, including weight-bearing range of motion, anterior/posterior contact position, and tibio-femoral rotation.Introduction
Materials and Methods
We have previously described the mid- to long-term
results of conventional simple varus intertrochanteric osteotomy
for osteonecrosis of the femoral head, showing that 19 of the 26
hips had good or excellent results. We extended the follow-up to
a mean of 18.1 years (10.5 to 26) including a total of 34 hips in
28 patients, with a mean age at surgery of 33 years (19 to 53).
There were 18 men and ten women and 25 hips (74%) had a satisfactory
result with a Harris hip score ≥ 80. In all, six hips needed total
hip replacement (THR) or hemiarthroplasty. The collapse of the femoral
head or narrowing of the joint space was found to have progressed
in nine hips (26%). Leg shortening after osteotomy was a mean of
19 mm (8 to 36). With conversion to THR or hemiarthroplasty as the
endpoint, the ten-year survival rate was 88.2% (95% confidence interval
(CI) 82.7 to 93.7) and the 20-year survival rate was 79.7% (95%
CI 72.1 to 87.3); four hips were converted at ten years and other
two hips were converted at 20 years. Shortening of the leg after osteotomy remains a concern; however,
the conventional varus half-wedge osteotomy provides favourable
long-term results in hips with less than two-thirds of the medial
part of the femoral head affected by necrotic bone and with normal
bone superolaterally.
Cam type femoro-acetabular impingement is defined by a reduced femoral head-neck offset and by excessive bone at antero-lateral femoral head-neck junction. Reconstruction of the femoral head-neck offset by removing the femoral bony prominence is a common treatment for cam type impingement. In many cases, the goal of this treatment is to make the antero-lateral head-neck offset symmetrical to the postero-lateral offset. However, guidelines for bony removal are not well established. The objective of this study is to examine if the antero-lateral and postero-lateral femoral offsets are symmetrical in normal healthy hips. CT analyses of the anatomic geometry of the femoral head and neck were performed. Hip joints with any evidence of cartilage defects and impingement were excluded. Eight cadaveric hips (3 right and 5 left hips) were examined. The average age of the cadavers was 65.1±15.1 years. A peripheral QCT scanner was used which provided 0.2 x 0.2 x 2 mm resolution. To improve the resolution of the final result, each hip joint was scanned in three different scanning directions (sagittal, coronal, and axial scanning planes). A custom imaging fixture was built to position a joint sample in three different scanning planes and a custom irrigation system supplied saline to protect the sample from dehydration. A custom segmentation program was developed to delineate the bony contours of the femoral head and neck in a fully automated manner. The segmentation data from the three differenent imaging planes were merged and a 3D solid model of each hip joint was created. The prominence of the femoral head was determined by the distance of the 3D head from an ideal sphere fitted into the 3D model. All the femoral heads were found to be asymmetric. Prominence of posteromedial femoral head averaged 0.105 mm more than the antero-medial femoral head. The antero-lateral head-neck junction was also found to be more prominent than the postero-lateral head-neck junction by an average of 1.09 mm. Asymmetry in the femoral head and femoral head-neck junction was a general finding in normal hip joints. The conventional approach of symmetric reconstruction of femoral head-neck junction may result in unnecessary removal of bone at the antero-lateral head-neck junction and potentially increase the risk of femoral neck fracture.
In Far East, including Japan and the Middle East, daily activities are frequently carried out on the floor. Deep flexion of the knee joint is therefore very important in these societies. Some patients who underwent total knee arthroplasty (TKA) in these countries often perform deep flexion activity, such as squatting, cross-leg sitting and kneeling. However it is still unknown that deep flexion activity affects long term durability after TKA. The purpose of this study was to examine the correlation between deep flexion and long term durability. Between December 1989 and May 1997, 507 total knee arthroplasties were carried out in 371 patients using the Bi-Surface Knee System (Japan Medical Material, Osaka, Japan) at two institutions and routine rehabilitation program continued for one to two months after TKA. One patient who underwent simultaneous bilateral TKA was excluded because of pulmonary embolism within one month. The other 505 knees (370 patients) were divided into two groups according to the range of flexion after our routine rehabilitation program; one group (Group A: 207 knees) consisted of more than 135 degrees flexion knees and the other group (Group B: 298 knees) consists of less than 135 degrees flexion knees. Patients whose follow-up period was less than 10 years were excluded from this clinical evaluation. Range of flexion was measured preoperatively, at the time after routine rehabilitation program, and at the latest follow-up. Knee function was evaluated on the basis of Knee Society knee score and functional score preoperatively and at the latest follow-up. Kaplan-Meier survivorship analysis was performed with revision for any operation as the end point. In Group A, the mean preoperative range of flexion was 133.0±16.3 degrees, and at the time after routine rehabilitation program, this improved to 139.7±5.1 degrees. This angle maintained to 136.2±14.3 at the latest follow-up. In Group B, the mean preoperative range of flexion was 111.6±20.4 degrees, and at the time after routine rehabilitation program, this improved to 114.5±13.6 degrees. This angle maintained to 118.2±17.8 at the latest follow-up. The Knee Society knee score and functional score was improved from 43.0±16.9 points and 39.0±20.2 points preoperatively to 95.1±5.8 points and 51.8±21.2 points at the latest follow-up, respectively in Group A. The Knee Society knee score and functional score was improved from 37.1±16.7 points and 31.9±18.4 points preoperatively to 92.5±8.7 points and 53.1±26.1 points at the latest follow-up, respectively in Group B. Kaplan-Meier survivorship at 10-year was 95.5% in Group A and 96.2% in Group B with any operation as the end point. The survivorship between Group A and Group B was not statistically significant. Good range of flexion was maintained and Knee society score was excellent after a long time follow-up for the patients who achieved deep flexion after TKA. Deep flexion was proved not to affect long term durability in this Bi-Surface Knee System.
We report the mid- to long-term (mean 20.3 years, 10 to 32.5) results of the Chiari pelvic osteotomy in patients with pre- to advanced stage osteoarthritis in dysplastic hips. We followed 163 Japanese patients (173 hips) with a mean age at surgery of 20 years (9 to 54). Overall, 124 hips (72%) had satisfactory results, with Harris hip scores ≥ 80. Satisfactory results were seen in 105 of 134 hips with pre- or early osteoarthritis (78%) and 19 of 39 hips with advanced osteoarthritis (49%). A total of 15 hips (9%) underwent a total hip replacement (THR) with a mean interval between osteotomy and THR of 16.4 years. With conversion to THR as the endpoint, the 30-year survival rate was 85.9% (95% confidence interval 82.3 to 89.5). It was 91.8% for patients with pre- or early osteoarthritis and 43.6% for those with advanced osteoarthritis (p < 0.001). We now perform the Chiari osteotomy for patients with dysplastic hips showing poor joint congruency and who prefer a joint-conserving procedure to THR.
Thigh pain appears often after THA used of the cement-less femoral components, but the appearance mechanism of thigh pain does not have been elucidated. As one factor of manifestation of thigh pain, it has been guessed that the pressure from the inside of medullary cavity of bone by the stem. The purpose of this study is confirming whether the flexor reflex is caused, by using the femur of a rabbit that applied the pressure from the inside of medullary cavity of bone. Japanese white rabbits with weight of about 3kg were used. Evaluation of the appearance of the pain by the pressure was performed by measurement of the hind leg flexor activity produced by the flexor reflex. After confirming that appearance of the muscles activity by the pain reflex from adding the pain stimulus to the hind leg skin of rabbits, we loaded of the pressure into the inside of medullary cavity of bone and observed whether the muscles activity appears. As the laboratory animals model, we prepared two kinds of rabbits by the difference in the amount of reaming. And we tested how the differences show up between these two kinds of rabbits. In the rabbits with few amounts of reaming, the flexor reflex appeared in low pressure. But, in the rabbits with many amounts of reaming, the flexor reflex did not appear in high pressure, either. It is known that the somatic sensory nerves are distributed in the bone, and it is known that the sensory nerve ends exist in the medullary cavity of bone. It was suggested that the pain is induced, when the sensory nerve ends remained in the inside of medullary cavity of bone and the pressure in whicha reaction is possible was carried out there.
We evaluated intermediate-term results of primary cementless Omniflex prostheses. Forty-nine patients (57 hips) with a mean age of 44 years were observed for an average of 8.6 years. These results were inferior to those using other recent cementless total hip systems. The increasing prevalence of loosening and osteolysis with time are problems related to this Omniflex femoral component. Although the implant design is unique, the authors no longer use this system.
Prosthetic impingement after THA is to different for the angle and shape of the implant. Purpose of this study is examine the range of motion(ROM) on a computer when angle and shape of the implant are changed. The 3D implant models were created on a computer. The angle was measured in the flexion, extension, adduction direction byevery 0.1 degrees. There are three kinds of acetabular abduction angle, two kinds of acetabular anteversion angle and two kinds of femoral anteversion angle. There are three kinds of the radius of neck and the neck shaft angle. All 324 patterns of the above model were measured. When the radius of neck decreased, the ROM increased in all cases. When the neck shaft angle decreased, the ROM increased by almost all cases. When the acetabular anteversion angle increased, the ROM of flexion direction increased and adduction direction decreased, and as for the extension direction, all the factors had influenced the change in the ROM. When the acetabular angle increased, the ROM of the extension direction increased and the flexion directions decreased. As for adduction direction, femoral anteversion angle, acetabular anteversion angles, and the radius of neck had influenced the ROM. When the femoral anteversion angle increased, the ROM of flexion direction increased and extension, adduction direction decreased. The clinical ROM is affected by the impingement of non-implant and the strain of the soft tissue. Therefore, It’ s considered that the clinical ROM is smaller than the ROM which was investigated in this study in many cases. When the radius of neck and the neck shaft angle decrease, the increase of the ROM expected. However the radius of the neck should not be decreased too much to avoid the decrease of the neck strength.
We compared the outcome of peri-operative humeral condylar fractures in patients undergoing a Coonrad-Morrey semiconstrained total elbow replacement with that of patients with rheumatoid arthritis undergoing the same procedure without fractures. In a consecutive series of 40 elbows in 33 patients, 13 elbows had a fracture in either condyle peri-operatively, and 27 elbows were intact. The fractured condyle was either fixed internally or excised. We found no statistical difference in the patients’ background, such as age, length of follow-up, immobilisation period, Larsen’s radiological grade, or Steinbrocker’s stage and functional class. There was also no statistical difference between the groups in relation to the Mayo Elbow Performance Score, muscle strength, range of movement, or radiolucency around the implants at a mean of 4.8 years (1.1 to 8.0) follow-up. We conclude that fractured condyles can be successfully treated with either internal fixation or excision, and cause no harmful effect.
We present the medium-term results of hybrid total hip arthroplasties using pre-coated stems with a second-generation cementing technique. The 128 hips in 111 patients (18 men and 93 women) were followed up at a mean of 11 years after surgery. The mean age at the time of surgery was 61 years. Both components of one hip were removed at ten months after surgery for infection. None of the other 127 femoral components showed possible, probable, or definite loosening at the most recent follow-up. Five acetabular components were revised for aseptic loosening, recurrent dislocation, or displacement of the polyethylene liner from the metal shell. The mean Harris hip score at follow-up was 84 points. A pre-coated femoral component with a second-generation cementing technique provides good clinical function and survival in the medium term.
A vascularised bone-graft procedure from the base of the second metacarpal was performed in 14 patients with nonunion of the scaphoid. There were 11 men and three women with a mean age of 22 years. In eight patients, who had dorsiflexed intercalated segment instability (DISI), an open wedge was formed at the site of nonunion, and the vascular pedicle was grafted from the volar side. In the six patients without DISI, transplantation was carried out through the same dorsal skin incision. Complete bony union was obtained in all patients after a mean post-operative period of 10.2 weeks, and DISI was corrected in all affected patients. According to Cooney’s clinical scoring system, the results were excellent in five, good in six, and fair in three patients. Because of its technical simplicity and the limited dissection needed, the procedure should be considered for the primary surgical treatment of patients with nonunion of the scaphoid.
The use of prostheses with porous surfaces in cementless total hip arthroplasty now predominates. Beads are popular for use as a porous coating, but their mechanical strength may be insufficient because of displacement of some of the beads from the coating. In this study, we propose a new porous surface, created by making direct holes in the metal surface using a YAG laser. A titanium-alloy (Ti-6Al-4V) rod was used. A Bead-type prosthesis was made by diffusion bonding pure titanium beads to the rod; it was 5 mm in diameter and 35% in porosity. A Laser type was made by directly creating holes in the same rod surface using a YAG laser; it was 5 mm in diameter and 33.7% in porosity. Both implants were evaluated in vivo using the hemitranscortical cylindrical model in two beagle dogs. Four prostheses were implanted into each femur through the lateral cortex, for a total of eight of each type, and remained in place for 12 weeks. Except for the proximal implant, push-out tests were performed to measure the shear strength of fixation of the implants to the cortical bone. For observations of the implant-bone interface, decalcified specimens of the proximal femur were stained with toluidine blue and observed with an optical microscope. The mean push-out strength of the Laser type was approximately 10.2 MPa and that of the Beads type was approximately 10.7 MPa. There was no significant difference in interface push-out strength between the groups. Bone ingrowth into both types was sufficient, however, some specimens of the Beads type demonstrated displacement of some of the beads from the rod surface. This study indicates that a porous surface created with a YAG laser might be useful not only for its shear strength, but also for the strength of the surface itself.
Hydroxyapatite (HA) is a bioactive material with a high affinity for bone. Ti-6Al-4V is lightweight and less biotoxic. Using these materials, a cementless hip prosthesis has been clinically used, consisting mainly of a Ti femoral stem coated with plasma-sprayed biocompatible HA. However, this type of stem entails several disadvantages: HA is likely to decompose at the coating; long term HA coating layer bonding to Ti is unstable and optimal HA thickness is unfeasible. In many actual cases, debonding of HA coating layer from the Ti surface was found upon removal of stems. To resolve these concerns, we started developing a new hip prosthesis using composite materials comprised of Ti-6Al-4V and HA containing bioinactive and highly stable glass in 1985. The cementless hip prosthesis, named HAPG-Profile, unites the bioactive stem surface with the surrounding bone via adhesive glass. In basic experiments, the glass-coated HAPG-Profile has been demonstrated to possess much higher bonding stability than the plasma-sprayed HA, with bone affinity and safety not compromised. On the basis of these results, we manufactured the HAPG-Profile jointly with DePuy International, UK, and initiated a clinical trial in January 1997 in the teaching Hospital, Nagoya University School of Medicine, and Tokyo Kosei Nenkin Hospital. A total of 63 patients were followed up for more than two year and evaluated according to the Japanese Orthopedic Association Score and Harris Hip Score (HHS) clinically, functionally and radiographically. The results of the two-year follow-up study indicated success of early fixation associated with favorable outcomes.
We followed, prospectively, 77 patients (90 hips) with early-stage, non-traumatic osteonecrosis of the femoral head for a mean period of nine years. At the time of final review, 56 (62%) were symptomatic. Using the Cox model, the initial radiological stage, the progression of staging, the reduction in size of the lesions and the percentage of necrotic volume on MRI were identified as risk factors. Using the Harris score of <
70 or surgery as the endpoint, the cumulative rates of survival were 60.0% at one year, 43.3% at two years, 38.9% at five years and 37.2% at ten years. Survival curves demonstrated that clinical deterioration could occur 90 months after the initial diagnosis, suggesting that asymptomatic patients should be followed carefully for several years. Radiological time-dependent reduction in size without progressive collapse may represent repair even when the collapse is minimal.
We present the mid- to long-term results of the Chiari pelvic osteotomy for dysplastic hips. We followed 135 hips in 129 patients, with a mean age at the time of surgery of 24 years, for a mean of 16.2 years. We used the anterior iliofemoral approach without trochanteric osteotomy in the initial 31 hips. Thereafter, we used transtrochanteric approaches in an attempt to ensure that the osteotomy was at the most appropriate level, and to advance the high-riding greater trochanter distally. The next 79 hips therefore underwent a posterolateral approach and the most recent 25 hips an Ollier lateral U approach. The clinical result was excellent or good in 103 hips (77%). The outcome in 104 hips in which we used a transtrochanteric approach was superior, the osteotomy level was more appropriate and a Trendelenburg gait less common than in 31 hips in which we used an anterior approach. We therefore recommend the use of a transtrochanteric approach in order to ensure that the osteotomy is at an appropriate level and in order to achieve effective distal advancement of the high-riding greater trochanter.
We present the long-term results of simple varus intertrochanteric osteotomy for osteonecrosis of the femoral head. We followed 26 hips in 20 patients, with a mean age at the time of surgery of 36 years, for a mean of 12.5 years. The mean varus angulation was 23°. The outcome in 19 of the hips (73%) was good or excellent; seven (27%) had a fair or poor result, with four needing some form of prosthetic arthroplasty. Simple varus intertrochanteric osteotomy is indicated, even if the extent of the capital infarct comprises more than 50% of the diameter of maximum radial distance from the circumference, provided that after operation the medial necrotic lesion measures less than two-thirds of the weight-bearing area, and the superolateral bone is normal.
