The Effects of Partial Wrist Denervation on Chronic Wrist Pain

PURPOSE: The purpose of this study is to evaluate analgesic benefit, patient satisfaction, range of motion and grip power of the patients after partial wrist denervation. MATERIALS AND METHODS: We retrospectively reviewed the medical records of 12 patients with chronic wrist pain treated with partial denervation. Mean age of the patients was 65 years. The leading cause of the pain was Kienbock's disease (7 cases). Berger's partial denervation technique was used, in which distal branches of the anterior and posterior interosseous nerve were resected through dorsal longitudinal incision. We recorded visual analogue scale (VAS) for pain, and range of motion and grip power for functional evaluation. RESULTS: Preoperative VAS for pain decreased from a mean of 6.1 to 1.5 during early postoperative period and 2.3 at the final follow-up (p<0.01). Flexion-extension and grip power improved significantly after surgery. All the patients could return to their daily activity. Ten patients (83%) showed satisfaction. CONCLUSION: It seems that partial denervation for chronic pain of the wrist is an easy technique that can provide satisfactory pain relief with preserving the wrist motion.

Effects of partial denervation on the differentiation of muscle fiber types in the rat / 体力科学

In this study, the rats were subjected to a partial denervation of the soleus muscle at the age of three weeks. After this, histochemical investigations were carried out to establish what kind of changes had occurred in the differentiation of the muscle fiber type as a result of this partial drop in muscle activity.<BR>The partial denervation was performed on the sinistral rat's soleus muscle, roughly 20% of the nerve bundles. After this, the dextral soleus muscle was used as the contralateral control muscle and excised after two, four and eight weeks, respectively. Frozen sections of muscle were stained with HE and myosin ATPase. The cross sectioned specimen were used for determining the muscle fiber count and type II fiber count.<BR>The results thus obtained show that, compared with the contralateral control muscle, the partially denervated muscle have an approximately 5% reduced muscle fiber count two and four weeks after the partial denervation, and the type II fiber count, too, decreased to approximately 2/3 and 1/5, respectively. However, at eight weeks post-operatively, the muscle fiber count for the partially denervated muscle become almost the same as that for the contralateral control muscle, while the type II fiber count has, at this stage, recovered to approximately half its contralateral control muscle.<BR>From these observations, it had been concluded that the reduction in muscle activity due to its partial denervation continues to act as a causal factor in the fiber type transformation untill four weeks after the partial denervation. The muscles evaluted eight weeks postoperatively showed an increase in type II fiber over the count determined four weeks after the partial denervation, and the muscle fiber count had also developed at eight weeks to value identical to that of the contralateral control muscles. Therefore, it has been concluded that the fiber type transformation in the muscle eight weeks after partial denervation is attributable to the reinnervation of the denervated muscle fibers due to the remaining intact motoneurons and to the resulting changes in motor unit size.