Hideya Kawamura

Standing radiographs cannot determine the correction in high tibial osteotomy

The use of standing radiographs to determine correction angles for high tibial osteotomy is not appropriate because the relative angle of the articular surfaces (condylar-plateau angle) in the weight-bearing knee changes after the osteotomy. This may give unpredictable results postoperatively. We found that the condylar-plateau angle in postoperative standing films is very similar to that seen in non-weight-bearing supine views, and suggest that these latter radiographs be used for pre-operative planning. We describe our early results, using a special osteotomy jig, in 140 knees.

New suture method for radial tears of the meniscus: biomechanical analysis of cross-suture and double horizontal suture techniques using cyclic load testing.

Background: Repair of complete radial meniscal tears is a key to restoring the mechanical integrity necessary to maintain hoop tension in the meniscus. The primary stability of the meniscal repair is one of the most important factors for meniscal healing, but the biomechanical structural properties of different repair techniques for complete radial meniscal tears remain unknown. Hypothesis: Our novel cross-suture technique with suturing oblique to the collagen fibrils of the meniscus will yield better fixation than the standard double horizontal suture technique with suturing parallel to the collagen fibrils in the meniscus. Study Design: Controlled laboratory study. Methods: Biomechanical investigation was performed on 40 fresh human menisci (2 groups of 20 menisci each) from patients who underwent total knee arthroplasty. In the cross-suture technique group (group A), the sutures crossed over 5 mm from the tear and 5 mm and 10 mm from the rim. In the double horizontal suture technique group (group B), the sutures were parallel and had the same attachment points as group A. The specimens were cyclically loaded 500 times between 5 and 30 N and then loaded to failure after completion of the cyclic load testing. Results: Compared with the double horizontal suture group, the cross-suture group had a significantly higher ultimate failure load (78.96 ± 19.27 N vs 68.16 ± 12.92 N; P < .05), significantly greater stiffness (8.01 ± 1.54 N/mm vs 6.46 ± 1.12 N/mm; P < .05), and significantly lower displacement (5.74 ± 1.84 mm vs 8.56 ± 2.39 mm; P < .05) after a 500–cycle loading protocol. Conclusion: Our cross-suture technique significantly improved the structural properties of the repaired complete radial meniscal tears. Clinical Relevance: The cross-suture technique for repair of radial meniscal tears provides high stability and could be a promising solution in young and in active patients.

A New, All-Inside Technique for Meniscus Repair

A new method for arthroscopic meniscal repair using sutures with multiple knots was developed, and its mechanical strength was evaluated. Sutures are passed arthroscopically through the torn meniscus using a needle with a cleft in its tip, and when the needle is withdrawn, knots are placed both in the meniscus and the joint capsule. Our method does not require additional skin incisions and can be performed for repair of posterior tears. Furthermore, this all-inside technique minimizes the risk of popliteal neurovascular injury. Biomechanical analysis using bovine menisci showed that the maximum frictional force between the suture and meniscus was greater than the maximum strength of a suture itself. Our method is simple and rapid, making it easy to insert multiple sutures to achieve adequate stability.

Spontaneous hemarthrosis of the knee in the elderly: Etiology and treatment

The etiology of spontaneous hemarthrosis of the knee in elderly patients with osteoarthritis is still unknown. This report discusses six cases, one that was managed with conservative measures and five in which arthroscopic evaluation and treatment were performed. These patients were elderly individuals whose chief complaint was knee pain and swelling about the joint, without an obvious history of trauma. Each of the five operative patients underwent arthroscopic surgery after repeated hemorrhage into the joint that did not respond to serial aspirations of large amounts of blood and immobilization, using a knee immobilizer. The roentgenograms of each involved knee demonstrated lateral compartment osteoarthritis. Arthroscopic examination revealed a degenerative flap tear of the posterior horn of the lateral meniscus in the five operative cases. These patients underwent arthroscopic resection of the injured lateral meniscus and did not experience a recurrence of the hemarthrosis. The origin of the bleeding was most likely from the peripheral arteries of the posterior horn of the lateral meniscus.

Factors associated with functional limitation in stair climbing in female Japanese patients with knee osteoarthritis.

BACKGROUND Osteoarthritis (OA) of the knee is a common form of arthritis, and affects quality of life. We investigated factors associated with functional limitation in stair climbing among female Japanese patients with knee OA. As weight is a known risk factor for knee OA, we focused on body weight at 40 years of age, and examined the association with present weight, past weight, and weight change. METHODS Subjects were 360 Japanese women aged 40-92 years who were newly diagnosed with knee OA at 3 university hospitals over a 1-year period. Factors associated with the severity of functional limitation in stair climbing were assessed by calculating odds ratios (OR) using the proportional odds model in logistic regression. RESULTS Weight at diagnosis showed a positive association with severe functional limitation in stair climbing; however, a negative association was observed for weight change since age 40. Further analysis indicated that the association with weight at age 40 (highest vs. lowest quartile, OR=2.84, 95% confidence interval: 1.03-7.83, trend p=0.071) is stronger than weight at diagnosis. Other significant characteristics were age (70+ vs. 40-59 years, OR=7.37), previous knee pain and/or swelling 12 years or more before diagnosis (OR=2.67), and physical work (OR=1.94). In addition, higher parity was found to be a negatively associated factor (for tripara or more, OR=0.41). CONCLUSIONS This study identified factors, such as heavy weight at age 40 and physical labor, which are potentially useful for preventing severe functional limitation for female knee OA patients. In addition, higher parity was associated with milder stair climbing limitation.

Validity of an oblique posterior condylar radiographic view for revision total knee arthroplasty

We have previously developed a radiographic technique, the oblique posterior condylar view, for assessment of the posterior aspect of the femoral condyles after total knee arthroplasty. The purpose of this study was to confirm the validity of this radiographic view based upon intra-operative findings at revision total knee arthroplasty. Lateral and oblique posterior condylar views were performed for 11 knees prior to revision total knee arthroplasty, and radiolucent lines or osteolysis of the posterior aspect of the femoral condyles were identified. These findings were compared with the intra-operative appearance of the posterior aspects of the femoral condyles. Statistical analysis showed that sensitivity and efficacy were significantly better for the oblique posterior condylar than the lateral view. This method can, therefore, be considered as suitable for routine follow-up radiographs of the femoral component and in the pre-operative planning of revision surgery.

Effect of HEBP (1-hydroxyethylidene-1, 1-bisphosphonic acid) on inflammation-mediated osteopenia in the rat

Trabecular bone volume of rat leg bones decreased following the subcutaneous injection of talcum (magnesium silicate). The effect of HEBP (1-hydroxyethylidene -1, 1-bisphosphonic acid) on this osteopenia was investigated.Bone mineral content (σGs/D) of the tibia decreased at both metaphysis and diaphysis during 3 week observation period following the inflammatory stimulus, and HEBP inhibited the decrease of σGs/D at metaphysis when administrated together with talcum. Breaking stress at mid point of the femur decreased significantly and femur ash contents showed a significant percent decrease of ash weight and ash volume with talcum administration. HEBP did not improve these parameters. Talcum significantly increased serum concentration of P and alkaline phosphatase level, but HEBP had no remarkable change in these serum parameters. This type of osteopenia can serve as a working model for osteoporosis and HEBP protected the trabecular bone loss at metaphysis of this model.

Investigation of Hospitalization Days after TKA Surgery

TKA術後在院日数を短縮させるべく問題点を解析するため，2005年に行われたTKA症例を検討した．対象症例は関節リウマチ患者を除く初回TKA 51例，52膝である．術後在院日数と手術時麻酔内容，術後の疼痛の度合い，術後合併症の有無について検討した．これらの症例の術後平均在院日数は30.8日であり，術後創治癒遅延や深部静脈血栓症の合併症を生じた症例では40.4日と延長していた．このような結果をふまえて，TKA術後在院日数を延長させるような合併症の予防対策を翌年にかけて計画した．