Extensor Indicis Proprius Transfer for Extensor Pollicis Longus Tendon Rupture Following Distal Radius Fracture

Background: Rupture of the extensor pollicis longus (EPL) tendon after distal radius fracture is a well-known complication. Two mechanisms have been proposed in the literature: a mechanical irritation of the tendon caused by bony prominence or implant material and direct microcirculatory compromise of the poorly vascularized tendon. Attempts to restore the function of the thumb using tendon graft or tendon repair have been reported with unpredictable results. In this report, we performed extensor indicis proprius (EIP) tendon transfer for extensor pollicis longus tendon rupture in patients with distal radius fracture using two to three small incisions and showed reliable results without functional deficit of the donor finger. Aim and Objectives: To reconstruct the ruptured EPL tendon after distal radius fracture via EI tendon transfer can not only minimize the donor site morbidity but also offer a reliable method. Materials and Methods: Totally 16 patients were recruited in this study from January 2004 to December 2013. In all patients, distal radius fracture with fracture fragment, bony spur or prominent fixation devices were found in the imaging study. EPL tendon rupture was diagnosed and reconstruction was performed with EIP tendon transfer in all cases. The functional outcomes of thumb are evaluated by: range of motion of thumb abduction/adduction (angle between index and thumb), elevated angle between table and MCP joint of thumb; extension lag of IP joint of thumb; opposition distance of thumb tip to the little finger tip and comparing with non-operated hand. Each parameter was scored as zero, one, two, or three points. Results: Among the 16 patients, 8 were follow up postoperatively for longer than 6 months. The parameters for functional outcome of the thumb were monitored and the results of surgery were graded as good, fair, or poor according to the total scores of each parameter. A total score of 7 to 9 points was graded as good, 4 to 6 points as fair, 0 to 3 points as poor. Seven patients showed good results, and 1 patient had poor results. Conclusion: Restoring the EPL tendon function using tendon transfer with extensor indicis proprius tendon to extensor pollicis longus tendon is a simple and reliable method. No obvious functional deficit of the index finger was encountered. All patients were satisfied with the range of motion of thumb, compared to the normal side, but they were still dissatisfied with the muscle power of pinch and grip function. A complete post-operative rehabilitation program is essential to obtain satisfactory outcomes.