RESUMO
PURPOSE: Distal radius (DR) fracture repair using the volar locked plating technique typically involves indirect fracture reduction, assessed using fluoroscopy, without direct visualization of the articular surface. This method of fracture repair may be guided by the rationale that volar radiocarpal ligament disruption may cause radiocarpal instability, although direct articular visualization may facilitate improved fracture reduction. This study investigated anatomical feasibility and articular surface visualization using volar ligament-sparing radiocarpal arthrotomy pertinent to DR fracture repair. METHODS: Ten fresh-frozen cadaveric specimens of the upper extremity underwent volar arthrotomy via the standard flexor carpi radialis approach with partial longitudinal sectioning of the long radiolunate and partial transverse sectioning of the short radiolunate ligaments to visualize the articular surface of the DR. Following arthrotomy, the visible surface of the DR was analyzed using digital photography. The wrist was disarticulated, and the fully exposed articular surface was photographed. The visible area of the articular surface was quantified using digital imaging software by calculating the ratio of the surface area visualized using the arthrotomy to the total articular surface area. RESULTS: The percentage of the articular surface area of the DR visualized using the volar arthrotomy was 76% ± 7.6% (range, 69%-90%), including both the scaphoid facet, lunate facet, and scapholunate ridge. CONCLUSIONS: Volar radiocarpal arthrotomy allows clinically relevant visualization of the articular surface of the DR, including the scaphoid and lunate facets. CLINICAL RELEVANCE: Radiocarpal arthrotomy may facilitate improved articular reduction during DR fracture repair via the volar approach.
RESUMO
PURPOSE: Distal radius (DR) fracture fixation with volar locked plating typically uses indirect fracture reduction without direct visualization of the articular surface in an attempt to preserve the volar radiocarpal ligaments and prevent iatrogenic radiocarpal instability. This study assessed the biomechanical stability after a volar radiocarpal arthrotomy for direct articular visualization for DR fracture repair compared to a standard trans-flexor carpi radialis approach without arthrotomy in a cadaver model. METHODS: Ten fresh-frozen upper extremity matched-pair cadaveric specimens were tested. For each pair, one limb underwent trans-FCR approach with a volar arthrotomy that partially sectioned the long and short radiolunate ligaments to visualize the DR articular surface (Group 1). The contralateral limb underwent standard trans-FCR approach without arthrotomy (Group 2). Following capsular repair (Group 1), all specimens (Groups 1 and 2) underwent biomechanical testing, including axial loading (22.2 N, 44.5 N, 89.0 N, 177.9 N), volar translational, and dorsal translation loading (22.2 N, 44.5 N, 89.0 N) to assess carpal stability using both fluoroscopy and motion capture. Ulnar carpal translation was assessed using the Gilula method, measuring radiographic lunate overhang from the ulnar edge of the lunate fossa relative to the full width of the lunate. Dorsal and volar translation were assessed by measuring lunate overhang with respect to the dorsal or volar radial cortex. To simulate fractures with dorsal radiocarpal ligament disruption, the dorsal capsule was sectioned, and the biomechanical comparisons were repeated. RESULTS: Ulnar translation of the lunate remained below 2 mm for both groups in all testing scenarios. No significant differences were identified in ulnar, volar, or dorsal translation with increasing loads between the groups. CONCLUSIONS: This volar ligament-sparing radiocarpal arthrotomy did not cause biomechanical radiocarpal instability. CLINICAL RELEVANCE: This arthrotomy may provide enhanced visualization of the DR articular surface during fracture fixation without causing iatrogenic wrist instability.