Scaphoid Excision and Bicolumnar Carpal Fusion with Retrograde Headless Screws.

Scaphoid excision and partial wrist fusion is used for the treatment of scapholunate advanced collapse/scaphoid nonunion advanced collapse wrist arthritis. The purpose of this study was to report midterm functional and radiographic outcomes in a series of patients who underwent bicolumnar fusion of the lunocapitate and triquetrohamate joints using retrograde headless screws.  Twenty-three consecutive patients (25 wrists) underwent surgery with this technique from January 2014 to May 2017 with a minimum follow-up of 1 year. Assessment consisted of range of motion, grip, and pinch strength. Patient-reported outcome measures included disabilities of the arm, shoulder, and hand (DASH) and patient-rated wrist evaluation (PRWE) scores. Fusion rates and the radiolunate joint were evaluated radiographically. The relationship between wrist range of motion and midcarpal fusion angle (neutral position vs. extended capitolunate fusion angle > 20 degrees) was analyzed.  Average follow-up was 18 months. Mean wrist extension was 41 degrees, flexion 36 degrees, and radial-ulnar deviation arc was 43 degrees. Grip strength was 39 kg and pinch 9 kg. Residual pain for activities of daily living was 1.6 (visual analog scale). The mean DASH and PRWE scores were 19 ± 16 and 28 ± 18, respectively. Patients with an extended capitolunate fusion angle trended toward more wrist extension but this did not reach statistical significance (  = 0.17).  With retrograde headless compression screws, the proximal articular surface of the lunate is not violated, preserving the residual load-bearing articulation. Patients maintained a functional flexion-extension arc of motion with grip-pinch strength close to normal. Capitolunate fusion angle greater than 20 degrees may provide more wrist extension but further studies are needed to demonstrate this.  This is a Level IV study.