Is distal ulna resection influential on outcomes of distal radius malunion corrective osteotomies?

INTRODUCTION

The mechanical repercussions of distal radius malunion on the distal radio-ulnar (DRU) joint are common and inconsistently corrected by radius osteotomy alone. Ulnar resection has thus become a palliative solution.

HYPOTHESES

Does ulna resection influence the outcomes of distal radius malunion corrective osteotomies? What preoperative factors warrant preserving the distal radio-ulnar joint?

PATIENTS AND METHODS

Twenty-one corrective osteotomies of the radius were retrospectively reviewed. Ulna resection was performed in cases of cartilage damage, joint incongruence, or persistent stiffness in pronosupination after osteotomy of the radius. After the osteotomies, two groups were identified: 10 cases with preservation of the distal end of the ulna (DRU+) and eleven with distal resections (DRU-).

RESULTS

At review, all the osteotomies had united, with comparable anatomical restoration of the radial epiphysis for the two groups. We noted a statistically significant gain in mobility after osteotomy for both techniques (but no difference between them) and comparable grip strengths with 89.8% of the contralateral side for the DRU+ group versus 90.4% for the DRU- group. Pain (scale, 0-3) had significantly diminished for both groups decreasing from 1.9 to 0.3 for the DRU+ group and from 2.5 to 1.1 for the DRU- group, with no significant difference between them. The Mayo Clinic Wrist Score and the DASH score did not differ significantly with 73/100 and 13.5 for the DRU+ group compared with 68.2/100 and 20.2 for the DRU- group, respectively.

DISCUSSION

These results show that the impact of ulna resection after distal osteotomy of the radius is limited as reflected by radiological correction, mobility and grip strength. However, after resection pain in the ulnar tilt of the wrist due to instability of the distal ulnar stump was noted. Besides cartilage damage, ulnar deviation of over 5mm was, for this series, a constant factor in non-preservation of the DRU joint.

LEVEL OF EVIDENCE

Level IV. Retrospective study.