Prospective Clinical Trial Comparing Trapezial Denervation With Trapeziectomy for the Surgical Treatment of Arthritis at the Base of the Thumb.

BACKGROUND: Trapeziectomy is considered to be the "gold standard" procedure for first carpometacarpal joint (first CMCJ) osteoarthritis. First CMCJ denervation offers the potential benefit of a shorter procedure with bone and joint preservation and swift postoperative rehabilitation. This trial aimed to compare functional outcomes, patient satisfaction, quality of life, and cost effectiveness following these treatments. METHODS: This study was a prospective clinical trial commencing December 2005 to November 2013. A range of functional outcomes assessments were used preoperatively at 6 and 12 mo and 5 y after surgery. These included measurements of strength/motion, visual analogue score, Michigan Hand Outcomes and the European Quality of Life-5 Dimensions questionnaires. Data were analyzed using a two-sample t-test and Mann-Whitney test. RESULTS: A total of 45 patients were studied of 55 recruited. Age ranged from 41 to 72 (mean = 59). Thirty-five patients underwent denervation and 10 initially had trapeziectomy. Nine patients were converted to trapeziectomy within an average of 6 to 12 mo. There was no significant difference in the functional outcomes at different points of follow-ups. Similarly, there was no significant difference in the time of return to work or cost effectiveness. Denervation achieved a success rate of just above 70%, whereas no revisions were required for the trapeziectomy group. CONCLUSIONS: There was no difference between the two treatments. First CMCJ denervation does not appear to be superior to trapeziectomy. However, the advantage of rapid rehabilitation makes it more favored by patients but at the expense of 30% reoperation rate. LEVEL OF EVIDENCE: Level II.

Poly(L-Lactide) microfilaments enhance peripheral nerve regeneration across extended nerve lesions.

After injury, axonal regeneration occurs across short gaps in the peripheral nervous system, but regeneration across larger gaps remains a challenge. To improve regeneration across extended nerve defects, we have fabricated novel microfilaments with the capability for drug release to support cellular migration and guide axonal growth across a lesion. In this study, we examine the nerve repair parameters of non-loaded filaments. To examine the influence of packing density on nerve repair, wet-spun poly(L-Lactide) (PLLA) microfilaments were bundled at densities of 3.75, 7.5, 15, and 30% to bridge a 1.0-cm gap lesion in the rat sciatic nerve. After 10 weeks, nerve cable formation increased significantly in the filament bundled groups when compared to empty-tube controls. At lower packing densities, the number of myelinated axons was more than twice that of controls or the highest packing density. In a consecutive experiment, PLLA bundles with lower filament-packing density were examined for nerve repair across 1.4- and 1.8-cm gaps. After 10 weeks, the number of successful regenerated nerves receiving filaments was more than twice that of controls. In addition, nerve cable areas for control groups were significantly less than those observed for filament groups. Axonal growth across 1.4- and 1.8-cm gaps was more consistent for the filament groups than for controls. These initial results demonstrate that PLLA microfilaments enhance nerve repair and regeneration across large nerve defects, even in the absence of drug release. Ongoing studies are examining nerve regeneration using microfilaments designed to release neurotrophins or cyclic AMP.

Resection of the sciatic, peroneal, or tibial nerves: assessment of functional status.

BACKGROUND: Lower-extremity tumors are often treated by amputation rather than limb-sparing excision that sacrifices the sciatic nerve or a branch. This study assessed the functional outcome of major nerve sacrifice during limb-sparing resections for lower-extremity soft tissue sarcoma. METHODS: Patients who underwent division of the sciatic, tibial, or peroneal nerve(s) during limb-sparing sarcoma surgery (January 1982 through June 2000) were identified. Eleven surviving patients evaluated their pre- and postoperative functional status by self-administered questionnaire (six sciatic, two tibial, and three peroneal nerve divisions). RESULTS: Eighteen patients (10 male, 8 female; 14-84 years old) had nine primary and nine locally recurrent tumors. Tumors were high (16) or low grade (two). Five patients died of disease and two died of other causes. Median overall survival was 50 months. One of 11 reported increased pain. Eight had new phantom sensations with a median intensity of 4.5 (1 = least; 10 = most). All patients used an ankle brace to walk after a sciatic (four) or peroneal (one) division. Walking ability and distance after surgery was unchanged (nine), improved (one), and worsened (one). Standing improved in 7 of 11 patients. Proprioception in the affected extremity was retained in six. The median postoperative leg functional score was 8 (1 = worst; 10 = best). No patient developed foot ulcers. One patient underwent amputation for recurrence. All patients preferred their status over having an amputation. CONCLUSIONS: Objectively and subjectively, division of the major lower-extremity nerves causes acceptable functional deficits in most patients. Resection of affected sciatic nerve (branches) during limb-sparing tumor surgery is an excellent alternative to amputation.

Studies of neuroplasticity with transcranial magnetic stimulation.

In recent years, there has been increasing interest in studies of brain plasticity. Although still loosely defined, this term describes the ability of the brain to change. Cortical plasticity encompasses a wide variety of phenomena and mechanisms, including modifications in cortical properties such as strength of internal connections, representational patterns, or neuronal modifications, either morphological or functional (Donoghue et al., 1996). We focus on the description of different ways in which transcranial magnetic stimulation (TMS) can be used to study patterns of reorganization and some of the mechanisms involved in these changes. Correlation between TMS and neuroimaging studies in humans and animal studies addressing similar questions is discussed. It is important to identify in each situation whether plasticity plays a beneficial role or is maladaptive in terms of functional compensation. The understanding of patterns, mechanisms, and functional relevance of cortical plasticity will hopefully lead to the design of effective strategies to enhance plasticity when it is beneficial and to down-regulate it when it is maladaptive. An example of a possible strategy, using TMS, is discussed.