Special aspects of wrist arthritis management for SLAC and SNAC wrists using midcarpal arthrodesis: results of bilateral operations and conversion to total arthrodesis.

Although midcarpal wrist arthrodesis is recognized as a standard procedure to treat scapholuate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) of the wrist, little has been reported about patients with bilateral involvement and the number, cause, and results of failed cases requiring conversion to total wrist arthrodesis. This study investigated the results of 20 patients with bilateral procedures and of 22 patients who underwent total wrist fusion after failed midcarpal arthrodesis out of an overall group of 907 patients treated by this method during a 12-year period. Of these, 16 bilateral and 20 converted cases were reexamined after an average of 48 months and 42 months, respectively. Patients after bilateral midcarpal arthrodesis experienced a pain reduction by an average of 54% of the preoperative pain values at rest and by 56% at stress on the visual analog scale (scale range: 0 to 100) and from intolerable (3.7) to pain only during stress (1.9) on the verbal scale (scale range: I to 4). A mean arc of wrist extension and flexion of 53 degrees on the right and 49 of the left wrist was preserved. The mean DASH score was 45 points and 70% of the patients felt impaired only during certain activities. Total arthrodesis reduced pain in 18 of 20 reexamined wrists by 67% of the previous values after the failed partial arthrodesis at rest and by 46% at stress on the visual analog scale andfrom intolerable pain (3.7) to pain only during stress (2.1) on the verbal scale. Seven of the 20 reexamined patients noted complete pain relief at rest and two also under stress conditions. The DASH score averaged 39 points. A mean Krimmer score of 46 points and a mean Buck-Gramcko and Lohman evaluation of 6 points represented a satisfactory result. Grip strength of the operated hand averaged 53% of the opposite side. Subjectively, 30% felt impaired only during certain activities, 55%felt considerably and 15% strongly limited in daily life. However, all but two patients were satisfied with the secondary total wrist fusion as pain was considerably reduced. Midcarpal arthrodesis reliably reduced pain and preserved valuable wrist mobility thus improving daily activity and quality of life also in bilateral carpal collapse. In the rare cases when midcarpal arthrodesis failed, total wrist arthrodesis markedly improved the complaints in most patients, but in contrast to other studies complete pain was seldom.