Gil, Joseph A.

Abstract Introduction The costo-osteochondral autograft, vascularized medial femoral trochlear osteochondral autograft, and proximal hamate autograft have been used for the reconstruction of unsalvageable proximal pole scaphoid nonunions. Our hypothesis is that there is no difference in carpal kinematics after the proximal pole of the scaphoid is reconstructed with these three graft options. Methods Wireless sensors were mounted to the carpus that was loaded through cyclical motion. Each specimen was tested under a series of the three reconstructed conditions and their kinematics compared. Results No significant differences were found in scapholunate and lunocapitate joint motion during wrist flexion-extension and wrist radioulnar deviation between the three reconstructed conditions (p > 0.05). Discussion and Conclusion There are minimal differences in carpal kinematics when comparing reconstruction of the proximal pole of the scaphoid with the costoosteochondral, medial femoral trochlear, and proximal hamate grafts.

Background: The objective of this study was to determine whether reconstruction of the proximal pole of the scaphoid with a proximal hamate graft restores native carpal kinematics. Methods: A cadaveric study was designed assessing wrist kinematic after proximal hamate graft for proximal pole of the scaphoid nonunion. Wireless sensors were mounted to the carpus using a custom pin and suture anchor system to 8 cadavers. A wrist simulator was used to move the wrist through a cyclical motion about the flexion/extension and radial/ulnar deviation axes. Each specimen was tested under a series of 3 conditions: (1) a native state, “Intact”; (2) fractured scaphoid proximal pole, “Fracture”; and (3) post-reconstruction of the proximal pole of the scaphoid using a proximal hamate graft, “Graft.” Results: The fracture condition resulted in a statistically significant change in scapholunate kinematics across the entire arc of motion relative to the intact condition. Reconstruction with proximal hamate grafts restored scapholunate kinematics close to the intact state in both flexion/extension and radial/ulnar deviation axes. The lunocapitate flexion during wrist flexion was significantly different after the hamate graft reconstruction. Conclusions: Proximal hamate to scaphoid transfer resulted in restoration of near normal carpal kinematics to the intact state.

Background: The purpose of this study is to describe three radiographic stress tests that could be used to examine for distal radioulnar joint (DRUJ) instability intraoperatively, and to determine their ability to detect DRUJ instability after sequentially sectioning the DRUJ. Methods: Eleven fresh frozen cadaveric upper extremities (mean age 52.6 ± 14.9 years) were obtained. We sequentially sectioned the DRUJ. After each component of the DRUJ was sectioned, we performed three radiographic stress tests—squeeze test, ulnar pull in coronal plane, and simulated DRUJ ballotment test. Results: The squeeze test detected a significant increase in diastasis relative to the intact DRUJ after sectioning of the foveal insertion of the triangular fibrocartilage complex (TFCC; 1.0 mm) and the distal oblique bundle (DOB; 1.2 mm). The ulnar pull test in the coronal plane detected a significant increase in diastasis relative to the intact DRUJ after sectioning of the dorsal and volar radioulnar ligaments (2 mm), the foveal insertion of the TFCC (2.6 mm), and the DOB (4.4 mm). The simulated DRUJ ballotment test detected a significant increase in dorsal translation of the ulna relative to the intact DRUJ with sectioning of the foveal insertion of the TFCC (4.9 mm) and the DOB (5.6 mm). Conclusion: The squeeze test and simulated DRUJ ballotment test detect a significant increase in diastasis after the foveal attachment of the TFCC was sectioned. The ulnar pull test in the coronal plane was the most sensitive test for detecting a significant increase in diastasis relative to the intact DRUJ.