Step-Cut Osteotomy for Ulnar Shortening
Ulnar shortening osteotomy is a widely accepted procedure for surgical treatment of ulnar impaction syndrome, but many techniques require special instrumentation to achieve accurate shortening, adequate fixation, and sufficient rotational control. In the November 2, 2016 issue of The Journal of Bone & Joint Surgery, Papatheodorou et al. report on outcomes in 164 patients who underwent so-called “step-cut” osteotomies for positive ulnar variances that ranged from +1 to +6 mm.
The technique itself, which utilizes a standard neutralization plate and lag screw for fixation, is summarized and illustrated in the article. The authors emphasize that the step-cut approach does not require special jigs or instrumentation.
Patients were followed for a median of 66 months. The overall union rate was 98.8%; postoperative ulnar variance ranged from –1 to +1.5 mm after a mean overall ulnar shortening of 2.5 mm. All patients had significant postoperative improvements in pain, range of motion, grip strength, and Mayo Modified Wrist Score. Plate removal due to irritation was necessary in only 12 (7.3%) of the patients.
The authors also found in these patients “a lower rate of degenerative changes at the distal radioulnar joint compared with rates reported in previous studies.” They attribute this to the relatively small amount of ulnar shortening with the step-cut procedure, which they surmise “diminishes the rate of articular incongruity and hence arthritis of the distal radioulnar joint.” On the cost side of the matter, the authors noted that at their institution, special ulnar osteotomy systems cost almost 10 times more than a standard neutralization plate.