Low-profile locking-plate vs. the conventional AO system: early comparative results in wrist arthrodesis.

Introduction: Total wrist arthrodesis represents a reliable salvage procedure for severe painful conditions of the wrist. To date, wrist arthrodesis using a dorsal plate reaching from the distal radius to the third metacarpal is still recommended. A new implant (APTUS© 2.5 TriLock Wrist Fusion Plate, Medartis Suisse) that does not cross the third carpometacarpal joint (CMCJ-3) has been introduced recently. The purpose of this retrospective study was to compare both implants concerning early functional and clinical results.

Materials And Methods: A total of 20 patients underwent total wrist arthrodesis [10, using the new APTUS© implant (APT); 10 using the Depuy-Synthes© LCP plates (AO)]. The postoperative control interval was 18.2 and 37.2 months in APT and AO, respectively. Clinical assessment included functional parameters such as active range of motion (AROM) for pronation and supination, grip strength, and passive range of motion of the CMCJ-3. Additionally the DASH score and the Krimmer wrist score as well as pain levels at rest and under stress conditions were evaluated.

Results: All patients showed osseous healing without complications except one case of non-union in APT. There were no significant differences between both groups concerning grip strength, AROM of the wrist, pain levels, DASH- and Krimmer Score. APT showed a significantly increased passive range of motion of the CMCJ-3 compared to the unaffected contralateral side.

Conclusions: The new implant shows similar functional results compared to the standard procedure. The main advantage of the new implant is the fact that no implant removal is necessary due to the unaffected CMCJ-3. Furthermore the mobility of the CMCJ slightly increased and showed positive impact on hand kinematics.