Osteophytenbedingtes Impingement verringert die Beweglichkeit bei in „Humpback“-Deformität fehlverheilter Skaphoidrekonstruktion

BACKGROUND: The gold standard in the treatment of scaphoid pseudarthrosis is reduction, interposition of an iliac crest graft and stabilization with a headless bone (Herbert) screw, aiming to reduce the frequently observed humpback deformity. This study correlated the extent of humpback deformity after scaphoid reconstruction to clinical and radiological postoperative parameters. MATERIAL AND METHODS: Between 2008 and 2010 a total of 56 patients with scaphoid pseudarthrosis were surgically treated. Of the patients 34 could be included in this retrospective study. The average follow-up period was 7.3 months. The humpback deformity was evaluated by computed tomography (CT) scan performed along the long axis of the scaphoid. The disability of the arm, shoulder and hand (DASH) score, grip strength (Jamar), range of motion (RoM), Mayo wrist score (MWS) and other parameters were used to determine the clinical outcome. The patients were divided into two groups: 1) no or only slight humpback deformity (<25°), 2) severe humpback deformity (>45°). RESULTS: The RoM and DASH scores were slightly better for the first group. The second group had a significantly increased incidence of osteophyte formation (p < 0.05) and decreased RoM (−16°). CONCLUSION: It is postulated that the main disadvantage of an nonreduced humpback deformity is the increased occurrence of osteophyte formation in the dorsal aspect of the scaphoid. This can cause an impingement during extension and leads to a significant restriction of movement of the wrist. LEVEL OF EVIDENCE: III