Better clinical results after closed- compared to open-wedge high tibial osteotomy in patients with medial knee osteoarthritis and varus leg alignment.

PURPOSE: Studies comparing mid- or long-term outcomes of open- and closed-wedge high tibial osteotomy are limited. Here, the midterm survival rate and clinical and radiographic outcomes were compared for these two techniques. The study hypothesis, based on short-term follow-up, was that after midterm follow-up, the two techniques would not differ. METHODS: A prospective follow-up study was conducted for a previously reported randomized controlled trial of an original 50 patients (25 open-wedge osteotomy and 25 closed-wedge osteotomy) with medial knee osteoarthritis and a varus leg alignment. We analyzed patients without knee arthroplasty (mean age 48.7 years, SD 8.0) for clinical and radiographic follow-up. RESULTS: Five patients in each group had undergone conversion to a total knee arthroplasty or unicompartmental knee arthroplasty, leaving 19 patients for analysis in each group. At 7.9 years of follow-up (range 7-9 years), survival did not differ significantly between groups (open-wedge group 81.3% [95% confidence interval (CI) 75.2-100], closed-wedge group 82.0% [95% CI 66.7-100]). At final follow-up, total Dutch Western Ontario and McMaster Universities Arthritis (WOMAC), Knee Society Score, and visual analog scale (VAS) pain did not differ between groups. However, the results were significantly better in the closed-wedge group for VAS satisfaction and WOMAC pain and stiffness compared to the open-wedge group. Radiographic evaluation did not differ between groups for any outcome at final follow-up. CONCLUSION: After a mean follow-up of 7.9 years, patients undergoing a closed-wedge osteotomy had favorable clinical results compared to those who underwent an open-wedge osteotomy. LEVEL OF EVIDENCE: II.

No local recurrence of enchondroma after curettage and plaster filling.

INTRODUCTION: The most common treatment of enchondromas is curettage (with or without adjuvant therapy) followed by cancellous bone grafting. To avoid donor-site morbidity of the iliac crest, we applied plaster of Paris as a bone defect filler after curettage of enchondromas. MATERIALS AND METHODS: We treated 19 enchondromas of the hand and foot in 19 patients (mean age 40 years, range 21-79 years) with curettage and filling of the cavity with sterile plaster of Paris (calcium sulphate/phosphate) tablets. RESULTS: The diagnosis was histologically confirmed in all cases. After a mean follow-up of 53 months (range 15-139 months), the mean functional Muskuloskeletal Tumor Society Score was 29.1 points (97%; range 28-30). There were no local recurrences although adjuvant therapy was not utilized. CONCLUSION: Plaster of Paris appears safe and effective as a bone-filling substance after curettage of enchondroma.

Distal tuberosity osteotomy in open wedge high tibial osteotomy can prevent patella infera: a new technique.

To prevent patella infera in open wedge high tibial osteotomy, a new operation technique was developed. Instead of a proximal tibial tuberosity osteotomy, a distal osteotomy was performed and the tuberosity was fixed with one screw to the tibia. Initial experience in 17 patients was evaluated and compared with results of 20 patients with open wedge high tibial osteotomy with proximal tuberosity osteotomy. Distal tuberosity osteotomy in open wedge high tibial osteotomy appears effective in preventing patella infera.

Decrease in nerve temperature: a model for increased temporal dispersion.

A decrease in nerve temperature causes a proportional decrease in conduction velocity which, in percentage terms, is equal for all nerve fibers. The absolute decrease in conduction velocity is larger for faster conducting nerve fibers. This results in a compression and a shift to lower values of the conduction velocity distribution and an increase in temporal dispersion. The purpose of this study was to determine if these effects could be detected by a combination of two collision techniques designed to obtain the motor conduction velocity distribution and refractory period distribution. In 12 healthy volunteers we measured the conduction velocity distribution in the median nerve at nerve temperatures of 25 and 40 degrees C. The results showed that our method could detect the predicted changes in conduction velocity distribution and temporal dispersion. We conclude that temperature change is a model that can be used to study temporal dispersion. This may be a first step towards distinguishing between the effects of conduction block and (abnormal) temporal dispersion in demyelinated nerve fibers.