Stabilization of the Proximal Ulnar Stump in the Sauvé-Kapandji Procedure by Reconstructing Distal Oblique Bundle

Abstract Background The most common Sauvé-Kapandji (S-K) postoperative complication is instability of the proximal Ulnar Stump. The distal oblique bundle (DOB) is a stable tissue used to stabilize the distal radioulnar joint. we have applied a method to stabilize the proximal ulnar stump by using an improved extensor carpi ulnaris to fix the ulnar stump and reconstruct the DOB to achieve a combination of dynamic and static stable tissue. Methods 15 patients who underwent the S-K operation after partial ulnar wrist extensor tendon fixation of the ulnar stump and reconstruction of DOB to stabilize the proximal ulnar stump were recruited. After surgery, the patients' wrist pain was evaluated with a visual analog scale (VAS). The Mayo scoring system was used to evaluate total function. The imaging findings included the ulnar and radial distances and the palmar/dorsal displacement distance of the proximal ulna stump. Results All 15 patients were followed up for an average of 32.5 months (ranging from 9 to 60 months). The wrist pain of all patients improved from an average of 6.5 ± 2.5 points before the operation to 2.4 ± 2.1 points after the operation. The grip strength increased from 4.5 (4.3) kg before surgery to 7.5 (3.5) kg after surgery, and the forearm rotation activity improved from 61 (16)° before surgery to 81 (13)° after surgery. The average radius of the ulna decreased from 11 mm to 9 mm, but there was no significant difference among the 12 patients. Lateral X-ray imaging revealed no instability of the proximal Ulnar Stump. Conclusion Extensor carpi ulnaris fixation of the ulnar stump and reconstruction of the DOB can achieve the combination of dynamic and static stable tissue, which is an effective method for preventing instability of the proximal ulnar stump Type of study/level of evidence Therapeutic IV.