Structural Versus Nonstructural Bone Grafting for the Treatment of Unstable Scaphoid Waist Nonunion Without Avascular Necrosis: A Randomized Clinical Trial.

PURPOSE: We evaluated the impact of structural versus nonstructural bone grafting on the time to union, scaphoid deformity correction, and clinical outcomes in adults with unstable scaphoid waist nonunion without avascular necrosis. We hypothesized that nonstructural grafting would provide earlier time to union, restoration of scaphoid anatomy, and equivalent clinical outcomes compared with structural grafting.

METHODS

We prospectively randomized 98 patients to undergo open reduction, iliac crest bone grafting with either corticocancellous (CC group) or cancellous bone only (C-only), and internal fixation using a Herbert screw. The lateral intrascaphoid angle (LISA) and scaphoid height length ratio (HLR) were measured on wrist computed tomography scans along the scaphoid longitudinal axis before surgery and an average of 84 weeks afterward. Pain, range of motion, grip strength, and Quick-Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score were measured before surgery and an average 84 weeks afterward.

RESULTS

The trajectory of scaphoid union showed a higher union rate of the C-only group at 12, 14, and 16 weeks after surgery. However, at 24 weeks after surgery, there was no difference between the groups, The union rate was 94% in patients treated with C-only and 90% with CC grafting. In patients with preoperative LISA less than 70° and/or HLR less than 0.80 (n = 53), there were no differences between the CC and C-only grafting techniques for radiographic and clinical outcomes, QuickDASH scores, and malunion rate. In patients who had preoperative LISA greater than 70° and/or HLR greater than 0.80 (n = 45), radiographic outcome measures, range of motion, and QuickDASH scores were significantly better in the CC than in the C-only group. Scaphoid malunion was observed in 9 of 22 of C-only patients (41%) and 4 of 23 of CC patients (18%).

CONCLUSIONS

The severity of the scaphoid deformity may be a factor in determining the best graft type, because this may affect the rate of successful deformity correction. Corticocancellous grafting in patients who had a high degree of scaphoid deformity provided consistent deformity correction and superior QuickDASH scores. Otherwise, C-only grafting provides earlier time to union and equivalent clinical and radiographic outcomes compared with CC grafting.

TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic I.