[Long-term results following denervation of the wrist in patients with stages II and III SLAC-/SNAC-wrist].

INTRODUCTION: Mid-carpal arthrodesis, proximal row carpectomy and wrist arthrodesis are commonly cited in the literature as successful methods for pain reduction in patients with advanced carpal collapse (SLAC-/SNAC-wrist stages II and III). However, studies of isolated wrist denervation in patients who still possess good wrist mobility appear to be an underrepresented topic, especially in the German literature.
PURPOSE: Based on follow-up results, it was possible to establish to what extent patients benefit long-term from isolated wrist denervation, whilst retaining wrist mobility. PATIENTS AND
METHOD: 46 patients (6 female, 40 male) with a diagnosis of SLAC-wrist (n = 10) or SNAC-wrist (n = 36) stages II and III underwent wrist denervation of points 1 - 4, 6, 9 and 10 according to Wilhelm, between 1990 and 2001, following a positive denervation test. No previous reconstructive wrist surgery had been performed on any of the patients, whose average age at the time of denervation was 47 years. In 29 cases the dominant hand was affected, and in 22 cases the symptoms could be classified as post-traumatic. Post-operative follow-up was possible in 32 out of 46 cases (70 %), and occurred on average 6.3 years post-denervation (range 2.3 to 14 years).
RESULTS: Twelve out of 32 patients (32 %) reported to be pain-free at follow-up, with a post-operative period ranging from 2.3 to 11.4 years (average 6.2 years). Six patients (18.75 %) continued to experience pain when load-bearing, which remained unchanged over a period of several years. Three patients (9 %) reported pain after stress, five patients (15.6 %) the recurrence of severe pain, which developed on average 3.8 years post-operatively. Two patients (6.25 %) experienced no analgesic benefits following wrist denervation, and four patients underwent wrist arthrodesis on average 13.5 months post-denervation, due to remaining or additional symptoms. Nineteen out of 32 patients subjectively reported a significant improvement following wrist denervation. Reassessment of range of movement post-denervation showed a reduction of 8.1 % in wrist extension/flexion, and 20 % in radio/ulna-abduction. Compared to the unaffected side, this represented an average loss of 28 % wrist extension/flexion, and 33.5 % radio/ulna-abduction. An average 51 % increase in hand strength could be shown at follow-up, leaving an average 30 % deficit compared to the unaffected hand. Evaluation of these results using the Krimmer score showed a good - very good outcome in 20 of the 32 patients (62.5 %); six patients were found to have a satisfactory outcome, and six patients a poor outcome. Subjective measures of pain (obtained using visual analogue scales) showed a reduction from 68.13 pre-operatively to 25.63 post-operatively. The DASH assessment (parts A and B) attained an average post-operative value of 17.1.
CONCLUSION: Denervation of the wrist in patients with SLAC-/SNAC-wrist stages II and III can achieve a long-term elimination or reduction of pain, whilst improving hand strength, and having only a minimal impact on wrist range of movement. Wrist denervation should therefore be given preference over wrist arthrodesis, midcarpal arthrodesis or proximal row carpectomy in patients with good wrist mobility.