Management and Outcome of Unusual Cases of Scapho-Capitate Syndrome

Background
Scaphocapitate Syndrome are rare wrist hyperextension injuries, where early diagnosis and appropriate management are uncommon. The characteristic features of these injuries include fracture of both the scaphoid and capitate with rotation of the proximal fragment of the capitate. Failure to diagnose and treat these injuries appropriately could lead to avascular necrosis, neural compromise, non-union, stiffness and functional impairment. Literature available regarding these injuries are only single case reports. We present our experience of eight years in diagnosing and treating these injuries with their outcomes.  

Materials and Methods
15 patients with Scaphocapitate syndrome have been treated at our center since 2014 whose demographic data including age, gender and injury data including type of injury, mechanism, associated injuries, presence of neural deficit, time interval from injury to presentation, method of treatment and their outcomes and complications were studied retrospectively. The patients were followed up serially with radiographs at every three months till two years, grip and pinch strength measurement every six months and subjective outcome measured with patient rated wrist evaluation (PRWE) score every year.  

Results
Most common mechanism of injury was wrist hyperextension injury secondary to fall on outstretched hand. The time interval between injury and presentation ranged between day of injury to 90 days. Three patients underwent primary lunocapitate fusion, while in the remaining patients, the fractures were stabilized with headless compression screws or K wires. 13 patients have completed a minimum follow-up of 12 months (range: 9 months- 8 years). None of the 12 patients of the ORIF group demonstrated any osteonecrosis of the capitate head in the follow-up. The mean grip strength in the ORIF group was 78.6% of the uninjured hand and 70% in the Lunocapitate fusion group. The former group gave an average score of eight while the latter gave 10 with PRWE. The range of wrist motion was obviously reduced in the fusion group than the ORIF group, however they were able to carry out all their daily activities including heavy manual labour devoid of any limitations. All these patients have demonstrated radiological union of the fracture/fusion with significant improvement in the functional scores.  

Conclusion
Early diagnosis and appropriate management are the key factors in successful outcomes of these rare injuries. Though the outcomes of salvage procedures are reasonable, Open reduction of the dislocation with internal fixation of the fractures and ligamentous reconstruction preserves the complex biomechanics of the wrist joint.