RESUMEN
PURPOSE: This study compared the biomechanical stability of transosseous repair and transosseous combined with capsular repair techniques to reattach the triangular fibrocartilage complex (TFCC) for distal radioulnar joint instability. METHODS: Eight adult cadaveric upper-extremity specimens were studied. Each underwent peripheral ulnar-sided detachment of the deep and superficial TFCC fibers and repair. Four groups were prepared sequentially: intact TFCC, disrupted TFCC, transosseous repair, and combined transosseous with capsular repair. Forearm rotational torque was measured in three wrist positions: 60° flexion, neutral position, and 60° extension. Maximum dorsal and palmar ulnar translations in response to a 20-N traction load were measured at nine wrist positions after stabilizing the humerus and radius. Measurements were taken before and after TFCC disruption and following repair. RESULTS: Clear instability of the radius relative to the ulna was observed after sectioning the deep and superficial fibers of the TFCC, and stability was markedly improved after reconstruction in all positions. Compared with the normal group, rotational torque was similar between the two repair methods. In the pronation palmar flexion and supination dorsal extension positions, dorsal-palmar translation was smaller in the combined transosseous with capsular repair group than in the transosseous repair-alone group. CONCLUSIONS: Triangular fibrocartilage complex deep fibers are the primary stabilizing structure of the distal radioulnar joint. In this cadaveric study, the combined transosseous with capsular repair technique demonstrated less dorsal-palmar translation compared with the transosseous-alone repair technique. CLINICAL RELEVANCE: Combined transosseous with capsular repair is expected to provide improved postoperative stability for patients with peripheral TFCC tears and distal radioulnar joint instability.
RESUMEN
PURPOSE: This study aimed to investigate the optimal tension for the reconstruction of the distal radioulnar ligaments (DRULs) in the treatment of the distal radioulnar joint (DRUJ) instability. METHODS: A total of eight human cadaver upper extremities were used. First, the Tekscan sensor film system was used to measure the contact characteristics of the intact DRUJ. Following this, the DRULs were resected, and the measurement was repeated. The DRULs were then reconstructed according to Adams' procedure, and the contact forces under different initial tension were compared with that of the intact group to obtain the optimal tension. At that point, the contact force of the DRUJ was close to normal. The reliability of the obtained tension was verified by translational testing, which reflected the stability of the DRUJ. RESULTS: In the neutral position, the contact force, area, and pressure inside DRUJ were 0.51 ± 0.10 N, 64.08 ± 11.58 mm2, and 8.33 ± 2.42 kPa, respectively. After the DRULs were resected, they were 0.19 ± 0.02 N, 41.75 ± 5.01 mm2, and 4.86 ± 1.06 kPa, respectively. The relationship between the tension and contact force was linear regression (Y = 0.0496x + 0.229, R2 = 0.9575, P < 0.0001). According to the equation, when the tension was 3.64-7.68 N, the contact force was close to normal. There was no statistical difference in the stability of the reconstructed DRUJ under this tension compared with the intact group (P = 0.08). CONCLUSION: By comparing the contact forces under different reconstruction tensions with the normal value, we obtained the optimal tension, which can provide the theoretical basis for the clinical treatment of chronic DRUJ instability.