Twelve patients (7.3%) had the plate removed because it was causing irritation. The removal was performed at least 18 months after the ulnar shortening osteotomy to reduce the risk of refracture7,10,17. There were no other complications except for the 2 nonunions described earlier.
Extra-articular ulnar shortening osteotomy has been widely used to manage positive ulnar variance in symptomatic patients with ulnar impaction syndrome. Many techniques for this osteotomy have been proposed, including those using special jigs, cutting guides, or shortening systems and different forms of fixation3-13. However, no technique has demonstrated clinical superiority.
The step-cut ulnar shortening osteotomy was designed to overcome the difficulties with rotational control experienced with transverse or oblique osteotomy and to decrease cost by avoiding the need for special instrumentation. The step-cut configuration of the ulna provides ample bone-to-bone contact, facilitating healing and control of rotation. Stable internal fixation in combination with rapid healing allows early wrist mobilization.
The current cohort demonstrated improvement in pain scores and wrist function as well as rapid healing postoperatively, confirming the efficacy of the step-cut ulnar shortening osteotomy. The MMWS improved in all patients, by a mean of 41.5 points. All patients returned to their previous work, at a mean of 4 months postoperatively.
Authors of previous studies have reported nonunion rates as high as 13% after ulnar shortening osteotomy8,18. In our large serial study of 164 patients, only 2 nonunions (1.2%) were noted and both healed after secondary surgery with autologous iliac crest bone-grafting. Although it is difficult to compare the actual times to union among the various studies, because of different radiographic criteria for defining union, it was usually achieved within 5 months regardless of the type of osteotomy. In the current study, the mean time to union was 8.2 weeks (range, 5 to 18 weeks), which compares favorably with the results of previous clinical studies.
Plate irritation is the most common complication leading to a reoperation after ulnar shortening osteotomy. In the current large serial cohort, the plate was removed from only 12 (7.3%) of 164 patients, whereas the implant removal rate after ulnar shortening osteotomy has been reported to be as high as 55%5,10,11,18-21. Iwasaki et al.19 documented a 55% plate removal rate in their cohort of 53 cases. In a study by Chen and Wolfe11, the plate was removed from 8 (44%) of 18 patients, and Pomerance20 reported a rate of implant removal of 35% in 40 patients. In the current cohort of patients treated with a step-cut osteotomy, the volar placement of the plate on the ulna diminished the need for plate removal. We believe that this is due to better soft-tissue coverage of the plate with volar placement. In addition, with use of techniques that require a jig, there is the potential for more extensive periosteal stripping of the ulna, which may increase the nonunion rate.
Distal radioulnar joint arthritis has been reported to develop in up to 38% of patients who have undergone ulnar shortening osteotomy7,18,22. However, the majority of patients with radiographic evidence of distal radioulnar joint arthritis are asymptomatic. Baek et al.22 reported that 6 (17%) of 36 patients developed arthritic changes in the distal radioulnar joint after ulnar shortening osteotomy, and Minami and Kato7 noted radiographic signs of distal radioulnar joint arthritis in 7 (28%) of 25 patients at a mean of 35 months. They determined the optimal amount of ulnar shortening to be a mean of 3 mm to obtain neutral ulnar variance7. Köppel et al.18 observed arthritic changes of the distal radioulnar joint in 18 (38%) of 47 patients at a mean of 18 months after ulnar shortening osteotomy, the goal of which was correction to 2 mm of negative ulnar variance. They found that the ulnar variance was reduced from a mean of +1.5 mm (range, −2 to +15 mm) preoperatively to a mean of −2.1 mm (range, −4 to +4 mm) postoperatively.
In a biomechanical study, Nishiwaki et al.2 suggested that there is some correlation between the amount of ulnar shortening and the development of distal radioulnar joint arthritis, as they found that the pressure at the distal radioulnar joint increased as the amount of the ulnar shortening increased.
Baek et al.22 reported a significant association between the amount of ulnar shortening and the development of distal radioulnar joint arthritis. They retrospectively reviewed the cases of 36 patients with idiopathic ulnar impaction syndrome. The goal of the ulnar shortening osteotomy was to obtain neutral to 2 mm of negative ulnar variance. They reported a high prevalence of arthritic changes of the distal radioulnar joint at a minimum of 5 years postoperatively in patients who underwent greater ulnar shortening. The mean ulnar shortening was 7.0 ± 2.0 mm in 6 patients with postoperative distal radioulnar joint arthritis and 4.8 ± 2.1 mm in 30 patients without such postoperative arthritic changes. However, intra-articular fractures of the distal radioulnar joint may also influence the congruity of the distal radioulnar joint and contribute to the development of arthritis at that joint.
In our retrospective review of 164 patients with idiopathic or posttraumatic ulnar impaction syndrome, we found that the step-cut ulnar shortening osteotomy resulted in a lower rate of degenerative changes at the distal radioulnar joint compared with rates reported in previous studies7,18,22. In our study, in which the median duration of follow-up was 66 months, asymptomatic degenerative changes of the distal radioulnar joint were noted on radiographs of 9 (5.5%) of the 164 patients. We believe that the reason for the lower rate of degenerative changes of the distal radioulnar joint in the current cohort is the smaller amount of ulnar shortening. The mean amount of ulnar shortening was 2.5 mm. Our goal was to unload the ulnocarpal joint by shortening the ulna by only a few millimeters and not necessarily to reduce ulnar variance to neutral. We strongly believe that this diminishes the rate of articular incongruity and hence arthritis of the distal radioulnar joint. However, the actual prevalence of distal radioulnar joint arthritis after ulnar shortening osteotomy still needs to be determined with longer follow-up since the arthritis may develop at a later time point.
The results of our statistical analysis also showed step-cut ulnar shortening osteotomy to be an effective method for decreasing pain and improving wrist function in patients with ulnar impaction syndrome, regardless of whether the postoperative ulnar variance is negative, neutral, or positive.
Our current cohort demonstrated that step-cut ulnar shortening osteotomy with a 7-hole 3.5-mm standard neutralization plate and a lag screw for fixation provides good-to-excellent functional results without the need for expensive surgical equipment. Although the outcomes of previous studies5,8,10,13,17 of ulnar shortening osteotomies done with special surgical devices were comparable with those in our current cohort, there is a noteworthy difference regarding the cost of the devices. At our institution, the cost for special ulnar osteotomy systems is almost 10 times higher than that for a 7-hole 3.5-mm standard neutralization plate.
The current study was limited by its retrospective nature and the absence of a control group. However, we found successful healing and a very low rate of implant removal in a large series of 164 ulnar shortening osteotomies performed by 2 surgeons and followed for a median of 66 months.
This study demonstrates that the step-cut ulnar shortening osteotomy is a safe and reliable technique resulting in rapid healing and an early return to functional activities. The volar placement of the plate diminishes the need for implant removal. The step-cut ulnar shortening osteotomy is a simple and less expensive technique that utilizes a 7-hole 3.5-mm standard neutralization plate and a lag screw for fixation, thereby avoiding the need for special instrumentation.
Investigation performed at the University of Pittsburgh, Orthopaedic Specialists–UPMC, Pittsburgh, Pennsylvania
Disclosure: No funding was received for this study. The Disclosure of Potential Conflicts of Interest forms are provided with the online version of this article.
1. Friedman SL, Palmer AK. The ulnar impaction syndrome. Hand Clin. 1991 ;7(2):295–310.
2. Nishiwaki M, Nakamura T, Nagura T, Toyama Y, Ikegami H. Ulnar-shortening effect on distal radioulnar joint pressure: a biomechanical study. J Hand Surg Am. 2008 ;33(2):198–205.
3. Darrow JC Jr, Linscheid RL, Dobyns JH, Mann JM 3rd, Wood MB, Beckenbaugh RD. Distal ulnar recession for disorders of the distal radioulnar joint. J Hand Surg Am. 1985 ;10(4):482–91.
4. Boulas HJ, Milek MA. Ulnar shortening for tears of the triangular fibrocartilaginous complex. J Hand Surg Am. 1990 ;15(3):415–20.
5. Wehbé MA, Cautilli DA. Ulnar shortening using the AO small distractor. J Hand Surg Am. 1995 ;20(6):959–64.
6. Hulsizer D, Weiss AP, Akelman E. Ulna-shortening osteotomy after failed arthroscopic debridement of the triangular fibrocartilage complex. J Hand Surg Am. 1997 ;22(4):694–8.
7. Minami A, Kato H. Ulnar shortening for triangular fibrocartilage complex tears associated with ulnar positive variance. J Hand Surg Am. 1998 ;23(5):904–8.
8. Rayhack JM, Gasser SI, Latta LL, Ouellette EA, Milne EL. Precision oblique osteotomy for shortening of the ulna. J Hand Surg Am. 1993 ;18(5):908–18.
9. Labosky DA, Waggy CA. Oblique ulnar shortening osteotomy by a single saw cut. J Hand Surg Am. 1996 ;21(1):48–59.
10. Mizuseki T, Tsuge K, Ikuta Y. Precise ulna-shortening osteotomy with a new device. J Hand Surg Am. 2001 ;26(5):931–9.
11. Chen NC, Wolfe SW. Ulna shortening osteotomy using a compression device. J Hand Surg Am. 2003 ;28(1):88–93.
12. Horn PC. The long ulnar sliding osteotomy. J Hand Surg Am. 2004 ;29(5):871–6.
13. Chennagiri R, Burge P. Pre-osteotomy plate application technique for ulnar shortening. J Hand Surg Br. 2004 ;29(5):453–7.
14. Darlis NA, Ferraz IC, Kaufmann RW, Sotereanos DG. Step-cut distal ulnar-shortening osteotomy. J Hand Surg Am. 2005 ;30(5):943–8.
15. Nakamura R, Horii E, Imaeda T, Nakao E, Kato H, Watanabe K. The ulnocarpal stress test in the diagnosis of ulnar-sided wrist pain. J Hand Surg Br. 1997 ;22(6):719–23.
16. Tomaino MM. The importance of the pronated grip x-ray view in evaluating ulnar variance. J Hand Surg Am. 2000 ;25(2):352–7.
17. Luria S, Lauder AJ, Trumble TE. Comparison of ulnar-shortening osteotomy with a new Trimed dynamic compression system versus the Synthes dynamic compression system: clinical study. J Hand Surg Am. 2008 ;33(9):1493–7.
18. Köppel M, Hargreaves IC, Herbert TJ. Ulnar shortening osteotomy for ulnar carpal instability and ulnar carpal impaction. J Hand Surg Br. 1997 ;22(4):451–6.
19. Iwasaki N, Ishikawa J, Kato H, Minami M, Minami A. Factors affecting results of ulnar shortening for ulnar impaction syndrome. Clin Orthop Relat Res. 2007 ;465:215–9.
20. Pomerance J. Plate removal after ulnar-shortening osteotomy. J Hand Surg Am. 2005 ;30(5):949–53.
21. Loh YC, Van Den Abbeele K, Stanley JK, Trail IA. The results of ulnar shortening for ulnar impaction syndrome. J Hand Surg Br. 1999 ;24(3):316–20.
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22. Baek GH, Lee HJ, Gong HS, Rhee SH, Kim J, Kim KW, Kong BY, Oh WS. Long-term outcomes of ulnar shortening osteotomy for idiopathic ulnar impaction syndrome: at least 5-years follow-up. Clin Orthop Surg. 2011 ;3(4):295–301. Epub 2011 Dec 1.