Innervation of the distal part of the vastus medialis muscle is endangered by splitting its muscle fibers during total knee replacement: an anatomical study using modified Sihler's technique.

Background and purpose - The distal part of the vastus medialis muscle is an important stabilizer for the patella. Thus, knowledge of the intramuscular nerve course and branching pattern is important to estimate whether the muscle's innervation is at risk if splitting the muscle. We determined the intramuscular course of the nerve branches supplying the distal part of the vastus medialis muscle to identify the surgical approach that best preserves its innervation.Material and methods - 8 vastus medialis muscles from embalmed anatomic specimens underwent Sihler's procedure to make soft tissue translucent while staining the nerves to study their intramuscular course. After dissection under transillumination using magnification glasses all nerve branches were evaluated.Results - The terminal nerve branches were located in different layers of the muscle and ran mostly parallel but also transverse to the muscle fibers. In half of the cases, the latter formed 1 to 3 anastomoses and coursed close to the myotendinous junction. Additionally, most of the branches extended into the ventromedial part of the knee joint capsule.Interpretation - To preserve the innervation of the distal part of the vastus medialis muscle, any split of the muscle during surgical approaches to the knee joint should be avoided.

Indomethacin versus meloxicam for prevention of heterotopic ossification after total hip arthroplasty.

BACKGROUND: Heterotopic ossification (HO) is a recognized postsurgical complication after total hip arthroplasty. Brooker et al. [6] established a grading system to define the degree of HO. The results of several studies have shown that non-steroidal anti-inflammatory drugs (NSAID) and radiation therapy reliably reduce the occurrence of severe HO. The exact cause and mechanism of bone formation are not known. The efficacy of indomethacin versus meloxicam for the prevention of heterotopic periarticular ossification and clinical NSAID side-effects after primary, cementless total hip arthroplasty was evaluated. METHODS: Probands underwent cementless total hip replacements at the Orthopaedic Department, Hospital Wiener Neustadt, from January 1997 to January 1998, did not take NSAID up to 4 weeks preoperatively and had no NSAID contraindications. Patients were separated into two groups by different hospitalisation floors. All patients selected for this study suffered from primary or secondary coxarthrosis. Data were collected as a prospective, randomised, parallel group study. Patients were given 50 mg indomethacin 2 times daily ( n=58) vs 7.5 mg meloxicam ( n=58) in a 12-day treatment course. RESULTS: A two-sided Cochran-Armitage trend test showed no statistically significant difference ( p<0.05) for one of the drugs regarding influence on ectopic bone formation according to the grading system of Brooker et al. CONCLUSION: Our study demonstrates that there is no statistically significant trend that indomethacin or meloxicam protects a hip arthroplasty better from heterotopic bone formation. We prefer indomethacin therapy because it is almost half the price of meloxicam therapy, and we recommend indomethacin in a 12-day treatment course given 50 mg 2 times daily as an effective, inexpensive and easily administered HO prophylaxis.