3D-Printed Patient-Specific Guides Versus Conventional Techniques for Scaphoid Reconstruction: A Comparative Study of 89 Cases.

Scaphoid non-union or malunion often produces a three-dimensional (3D) deformity that alters wrist biomechanics. Patient-specific instrumentation (PSI) has been introduced to improve reconstruction accuracy, but quantitative comparisons with conventional free-hand techniques remain limited. We retrospectively analyzed 115 scaphoid reconstructions performed between 2010 and 2019; 89 cases met inclusion criteria (45 PSI, 44 conventional). Distal-fragment rotation (flexion/extension, ulnar/radial inclination, pronation/supination) and translation were quantified using a Cartesian coordinate system centered on the proximal pole. A composite 3D deformity angle was calculated to assess global malalignment. PSI achieved greater absolute correction across several parameters. Sagittal flexion improved by 8.9° with PSI versus 5.8° with conventional reconstruction (p = 0.007 and p = 0.043, respectively). Ulnar inclination improved by 3° with PSI (p = 0.017) but not significantly with the conventional technique. The composite 3D deformity angle decreased by 8.4° with PSI and 6.9° conventionally. Despite a longer preoperative non-union duration in the PSI group, consolidation rates (91% vs 93%) and mean times to union were comparable between techniques. Vascularized grafts showed shorter, but non-significant, consolidation times. Both techniques effectively corrected scaphoid deformity. PSI enabled larger morphological corrections in cases with more severe baseline deformity. These findings suggest that PSI may facilitate correction in complex or long-standing non-unions; however, the clinical relevance of the observed 3D differences and operative efficiency remain to be determined.