A New and Easier Technique for the Treatment of Palmar Midcarpal Instability

Introduction Palmar midcarpal instability (MCI) is remains a challenging clinical entity that is not uncommonly seen in young adults, especially in young women. Generalized hypermobility plays a role, and patients become symptomatic after a trivial trauma or due to overuse. In general, patients are mainly treated nonoperatively, and reestablishing adequate proprioceptive control of the proximal row is the goal. Ultimately, in some patients where conservative treatment fails, operative treatment can be indicated in rare cases. We describe a new and easier technique for the treatment of palmar MCI.

Materials and Methods The new technique is described and the follow up of 11 patients is reported. This new technique uses only a dorsal approach. The ECRB is detached completely at its insertion on the 3rd metacarpal. It is then transposed, staying volar to the EDC tendons, to the dorsal aspect of the hamate, where it is firmly attached under appropriate tension using a bone anchor (Fig. 1). In this simple way, a dynamic stabilization of the carpus in MCI is achieved.

Results The longest FU in this series of 7 males and 4 females is now six years, the mean FU is now 2.5 years. Four patients did not have their prospective one-year FU visit yet, but were contacted by phone. Results are encouraging: 9 out of 11 patients report a more stable wrist, with, no or only mild complaints during ADL, and would have the procedure done again. Grip strength in the prospectively followed patients has improved but remains less than contralateral. On average, there is no decrease in active range of motion of the wrist. In the few prospectively followed patients with adequate FU, the VAS and PRWHE have improved dramatically. There were two failures.

Conclusion This new technique for the treatment of palmar MCI is much easier and less invasive. Preliminary results are similar to the more traditional technique and are thus encouraging.

Fig. 1 Transposition of the ECRB tendon onto the hamate (de Groot–Ritt technique) to treat palmar MCI not responding to conservative treatment.