No abstract

Long-term denervation of muscles results in fibrosis and fat replacement, which prevent muscles from regaining contractile function despite reinnervation. Therefore, prevention of muscle atrophy between nerve repair and muscle reinnervation may improve the functional outcome. A variety of growth factors play significant roles in muscle mass modulation and muscle regeneration. The purpose of the present study was to investigate the effect of fibroblast growth factor-2 (FGF2) and nerve growth factor (NGF) on muscle mass modulation after denervation and reinnervation using a nerve-to-muscle neurotization model. Growth factors were injected into the anterior tibial muscle after direct neurotization of muscles every 7 days up to 4 weeks after surgery. FGF2 significantly increased the amplitude of compound muscle action potentials (CMAPs), wet muscle weight, and the number of motor endplates, especially at higher concentration, compared to the vehicle. In contrast, NGF did not increase either the amplitude of CMAPs or muscle weight, although it significantly increased the number of motor endplates. These findings indicate that both growth factors enhance reinnervation of muscles; however, only FGF2 is involved in muscle mass modulation.

We conducted a retrospective review of 11 patients with bilateral Kienbock's disease from our series of 251 patients with Kienbock's disease. There were no significant differences in radiographic parameters, including ulnar variance and carpal bone angle, between those with unilateral and those with bilateral Kienbock's disease. None of the patients with bilateral disease had been treated with corticosteroids or had a systemic disease that predisposed to osteonecrosis. Thus, this study failed to demonstrate any risk factor for bilateral, as opposed to unilateral Kienbock's disease.

No abstract

Thirty-eight patients with advanced Kienböck's disease treated by limited wrist arthrodesis (LWA: n = 10) or radial osteotomy (RO: n = 28) for a fragmented lunate were retrospectively examined after an average of 47.9 and 68.1 months, respectively. Compared with pre-operative values, the active flexion-extension range of motion decreased by about 16.0 degrees in LWA and increased approximately 9.7 degrees in RO and the grip strength improved by approximately 7.5 kg in LWA and 8.0 kg in RO. In both groups, radiographs showed no significant progression of carpal collapse. Although LWA caused some decrease in wrist flexion-extension, both procedures are appropriate for surgical treatment of advanced Kienböck's disease. Most patients experienced a reduction in pain and were able to return to work.