Ligament injuries causing dorsal intercalary segment instability and comparison of tenodesis methods cadaver study

Project no. 21125 · Status: Kapanmış (Yayın bekleniyor) · 2020

Summary

Objective: Scapholunate instability is the most common cause of carpal instability. When this instability is left untreated, the mechanical relationship between the carpal bones is permanently disrupted, resulting in progressive degenerative changes in the radiocarpal and midcarpal joints. Different tenodesis methods are used in the treatment of acute or early chronic reducible scapholunate instability, where arthritis has not developed yet and the scapholunate ligament cannot be repaired. Although it has been reported that pain is reduced in the early follow up in clinical studies with these methods, radiological results differ between studies. The deterioration of these radiological parameters is associated with wrist osteoarthritis as previously stated. Therefore, more studies are needed to determine the tenodesis method that will improve the wrist biomechanics better and will last longer. In our study, two new tenodesis methods, spiral antipronation tenodesis, and anatomic front and back reconstruction (ANAFAB) were radiologically compared with triple ligament tenodesis (TLT; tri-ligament- tenodesis), in the cadaver wrists Materials and Methods: The study was carried out on a total of 17 fresh frozen cadaver specimens from 8 forearm and 9 elbow joints to the fingertips. Samples were randomly allocated to the groups treated with 3 different scapholunate instability treatment methods. These are TLT (n: 6), spiral antipronation tenodesis (n: 6, 1 sample was excluded) and ANAFAB tenodesis (n: 5) groups. In all examples, SLIL, DCSS, STT, DIC, RSC and LRL ligaments were cut in the same way to create scapholunate instability. Wrist CT scans were taken on the samples in 4 different situations, in intact condition, after the ligaments were cut, after the reconstruction and after the movement cycle. In all of these 4 cases, wrist CTs were taken in 6 different wrist positions. For every situation and every position through tomography images; Scapholunate (SL) distance, Scapholunate (SL) angle, Radioscaphoid (RS) angle, Radiolunate (RL) angle, Capitolunate (CL) angle, Dorsal scaphoid translation (Dt) measurements were made. Results: The ANAFAB tenodesis method provided more improvement in many variables compared to other methods and brought it closer to the healthy condition. This finding was observed in many angle variables in different positions. In antipronation tenodesis, although in some variables, better results are recorded in the neutral position compared to TLT, returning to the intact state is impaired in loaded positions such as flexion, radial deviation and clenching fist, which force the scaphoid to flexion. Conclusion: In the presence of severe scapholunate instability in which a several number of secondary stabilizers are injured, the ANAFAB tenodesis method may be preferred to the classical method, TLT tenodesis. The results of spiral antipronation tenodesis previously defined for these injuries were found to be similar to TLT.

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