Should central osteophytes within the articular cartilage of the lateral compartment be considered when determining the indication of unicompartmental knee arthroplasty for medial osteoarthritis?

Patients with central osteophytes in the lateral compartment may be poor candidates for unicompartmental knee arthroplasty (UKA) for medial knee arthritis given the thin overlying articular cartilage above the central osteophytes that is inadequate for supporting weight-bearing after UKA. Therefore, attempts should be made to detect central osteophytes to confirm suitability for UKA.

A Right Angle Guide for Distal Tuberosity Osteotomy With Medial Open Wedge High Tibial Osteotomy for Varus Knee Osteoarthritis.

Medial open wedge high tibial osteotomy (OWHTO) is usually performed with proximal tuberosity osteotomy or setting the osteotomy line proximal to the tuberosity. However, OWHTO can result in patellofemoral complications due to postoperative patella infera. A new OWHTO technique, biplanar osteotomy with a distal tuberosity osteotomy, was reported in 2004 to prevent postoperative patella infera.

Surgical Approach to Pigmented Villonodular Synovitis and Synovial Osteochondromatosis in Pathological Expansion of the Popliteus Bursa.

We orthopaedic surgeons are not familiar with the popliteus bursa. It is defined as the expansion in the synovial membrane of the posterolateral part of the knee that lies between the lateral meniscus and the tendon of the popliteus muscle. The popliteus bursa extends approximately 1 cm distal to the joint line and has 4 borders; the medial border is the peripheral margin of the lateral meniscus, the lateral border is the popliteus tendon, and the superior and inferior borders are formed by 2 fascicles.

Quality of life after staged bilateral total knee arthroplasty: a minimum five-year follow-up study of seventy-eight patients.

Purpose: Although many studies have been performed to evaluate the quality of life (QOL) and patient satisfaction after total knee arthroplasty (TKA), almost all evaluations were performed in patients after unilateral TKA or in patients after mixed unilateral and bilateral TKA. Accordingly, this study aimed to evaluate QOL after staged bilateral TKA.

Methods: A total of 78 patients who underwent staged bilateral TKA for varus knee osteoarthritis were included in this study.

The effect of morphine added to periarticular multimodal drug injection or spinal anesthesia on pain management and functional recovery after total knee arthroplasty.

Background: The efficacy of morphine added to periarticular multimodal drug injection (PMDI) for pain management after total knee arthroplasty (TKA) is controversial. Adding morphine to spinal anesthesia has reportedly improved pain relief for the first 24 h. We examined the effect of morphine added to PMDI or spinal anesthesia on pain management and functional recovery after TKA.

Preliminary results of managing large medial tibial defects in primary total knee arthroplasty: autogenous morcellised bone graft.

Purpose: This study reports a case series of 44 primary total knee arthroplasties (TKAs) using autogenous morcellised bone grafting for large (≥10-mm-deep) medial tibial defects, which are generally repaired using metal augmentation. The bone-grafting technique is described in detail and the radiological outcomes are presented.

Methods: A total of 44 TKAs were followed up for a mean period of 58 months (range 24-139 months).

Comparison of intraoperative anthropometric measurements of the proximal tibia and tibial component in total knee arthroplasty.

Background: Precise matching of the tibial component and resected bony surfaces and proper rotational implanting of the tibial component are crucial for successful total knee arthroplasty. We aimed to analyze the exact anthropometric proximal tibial data of Japanese patients undergoing total knee arthroplasty and correlate the measurements with the dimensions of current total knee arthroplasty systems.

Methods: A total of 703 knees in 566 Japanese patients who underwent total knee arthroplasty for osteoarthritis were included.

Femoral footprint of the popliteus tendon may be at the risk of damage during total knee arthroplasty.

Purpose: The present study focused on the prevalence of incidental excision of the femoral footprint of the popliteus tendon during total knee arthroplasty and its associated risk factors.

Methods: A total of 275 knee arthroplasties were performed for 226 patients with varus knee osteoarthritis. The status of the femoral footprint of the popliteus tendon was intraoperatively evaluated and classified into three groups (preserved, partially excised, and completely excised), and the prevalence of the excision was identified.

Evaluation of the size and position of the insertion of the anterior medial meniscus root in varus osteoarthritic knees.

Purpose: Recent studies have suggested radial displacement of the medial meniscus as a cause of varus knee osteoarthritis (OA). Two anatomical studies reported that such displacement may be associated with anterior insertion of the medial meniscus anterior horn. It was aimed to evaluate the location and area of this insertion in patients with advanced knee OA.

Potential risk of excising the femoral insertion of the popliteus tendon during primary total knee arthroplasty: a biometric study.

Background: During total knee arthroplasty (TKA), excision of the popliteus tendon leads to extensive static gaps and reduced mobility. The purpose of this study was to determine the positional relationship between the femoral insertion of the popliteus tendon and the bone cutting lines of various TKA systems.

Methods: This study included 21 cadaveric right femurs presenting no macroscopic deformity.

Autologous morselised bone grafting for medial tibial defects in total knee arthroplasty.

Purpose: To evaluate the outcome of autologous morselised bone grafting for a medial tibial defect of ≥10 mm deep in 45 total knee arthroplasties (TKAs).

Methods: 38 patients aged 46 to 85 (mean, 73) years underwent 45 TKAs and autologous morselised bone grafting for a medial tibial defect of ≥10 (range, 10-25) mm in depth by a single surgeon. In the first 19 TKAs, 2 resected subchondral bone plates from the lateral tibial plateau were driven into 2 gutters made on the floor of the medial tibial defect as bony support posts.

Quality of life after bilateral total knee arthroplasty determined by a 3-year longitudinal evaluation using the Japanese knee osteoarthritis measure.

Background: Recently, the Japanese knee osteoarthritis measure (JKOM), a new disease-specific and patient-derived quality of life (QOL) measure, has been developed. The objectives of this study were to longitudinally evaluate QOL assessed by JKOM and objective outcomes including knee society score (KSS), range of motion (ROM), and timed up and go test (TUG) of patients who underwent bilateral total knee arthroplasties (TKAs) for osteoarthritis; to evaluate correlations between JKOM and those objective outcomes; and to test our hypothesis that increased maximum flexion leads to better JKOM.

Methods: Forty patients with bilateral TKAs and ≥ 3-year follow-up were included.

Visualization of torn anterior cruciate ligament using 3-dimensional computed tomography.

Recently, a remnant-preserving anterior cruciate ligament (ACL) reconstruction technique has been developed. However, the preoperative condition of remnant ACL is occasionally difficult to evaluate by magnetic resonance imaging. The purpose of this study is to evaluate the accuracy of pre-operative visualization of remnant ACL using three-dimensional computed tomography (3D-CT).

Bone formation within the articular cartilage of the lateral compartment of varus osteoarthritic knees.

Background: One of the causes of failure after unicompartmental knee arthroplasty (UKA) for varus osteoarthritis is the progression of osteoarthritis in the lateral compartment. Bone formation within the articular cartilage has been reported as a possible cause of the deterioration of the osteoarthritis. However, its prevalence and histology are still uncertain.

Osteochondritis dissecans of the knee in identical twins: a report of two cases.

We report the second case of osteochondritis dissecans (OCD) of the knee in identical twins (bilaterally in one and unilaterally in the other). Fixations with bio-absorbable pins, cylindrical osteochondral graft, and osteochondral mosaicplasty were all successful and bone union was achieved. We considered that genetic factors remain essential even if other factors (particularly repetitive trauma) are mainly responsible for the occurrence of OCD.

Patellar morphology and femoral component geometry influence patellofemoral contact stress in total knee arthroplasty without patellar resurfacing.

Purpose: The objective of this study was to determine the effect of patellar morphology and implant design on patellofemoral contact stress in total knee arthroplasty (TKA) without patellar resurfacing.

Methods: Radiographic investigation: One hundred and fifty-seven knees of 127 patients were included in the study. Implants used in the present series were Low Contact Stress (LCS), Genesis II and NexGen.

Incidence of medial plica in 3,889 knee joints in the Japanese population.

Purpose: This study aimed to document the incidence of medial plicae (plica synovialis mediopatellaris) in a large sample of the Japanese population and classify them in a type-dependent manner.

Methods: The incidence of medial plicae was investigated during arthroscopic surgery of 3,889 knee joints in 3,563 patients (mean age, 35 years); medial plicae were classified according to Sakakibara's classification (type A, a cord-like elevation in the synovial wall; type B, a shelf-like appearance; type C, a large shelf-like appearance covering the anterior surface of the medial femoral condyle; and type D, double insertions into the medial wall or having a central defect). Of all the knee joints examined, 2,006 knees belonged to male patients and 1,883 to female patients.

Bony island within the articular cartilage of the knee in a child: a rare condition for early osteoarthritis.

Articular cartilage is a specific type of connective tissue composed of hydrated proteoglycans within a matrix of collagen fibrils. In the elderly population, it shows degenerative changes that may results in osteoarthritis. The more severe form of osteoarthritis occasionally demonstrates bone formation within the cartilage, which is designated as a bony protuberance, however, such lesions are rare in children.

Bony island within the articular cartilage of the knee in a child: a rare condition for early osteoarthritis.

Articular cartilage is a specific type of connective tissue composed of hydrated proteoglycans within a matrix of collagen fibrils. In the elderly population, it shows degenerative changes that may results in osteoarthritis. The more severe form of osteoarthritis occasionally demonstrates bone formation within the cartilage, which is designated as a bony protuberance, however, such lesions are rare in children.

Effect of estrogen on tissue elasticity of the ligament proper in rabbit anterior cruciate ligament: measurements using scanning acoustic microscopy.

Background: Previous epidemiological studies revealed that anterior cruciate ligament (ACL) injuries were more frequently seen in female athletes than in male athletes. To elucidate the pathogenetic roles of estrogen in ACL ruptures, the elasticity of ACL tissue was measured using a scanning acoustic microscope (SAM) in an estrogen-controlled animal model.

Methods: A total of 40 ovariectomized Japanese white rabbits were randomly divided into four groups according to the administered dose of 17beta-estradiol (groups L, M, H, and C).

Histologic findings and possible causes of osteochondritis dissecans of the knee.

Background: The histologic findings of osteochondritis dissecans of the knee vary widely, leading to differences in the interpretation of its origins. Hypothesis The differences in the histologic findings of osteochondritis dissecans might represent a course of pathologic progression.

Study Design: Descriptive laboratory study.

Does estrogen alter the mechanical properties of the anterior cruciate ligament? An experimental study in rabbits.

Background: It is well known that anterior cruciate ligament (ACL) injuries are commoner in female athletes. Accordingly, we hypothesized that serum estrogen may play some role in this sex difference. We evaluated the relationship between serum estrogen levels and the mechanical properties of the ACL in rabbits.

Muscle activity during a dash shown by 18F-fluorodeoxyglucose positron emission tomography.

Background: 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) has been used to examine muscle activity during running. The dash is a basic activity in various kinds of sports but differs from running in terms of intensity and severity. The purpose of this study was to evaluate muscle activity during running at full speed using FDG PET.