Patients with laxity of the distal radioulnar joint after distal radial fractures have impaired function, but no loss of strength.

Laxity of the distal radioulnar (DRU) joint after distal radial fractures has a worse general outcome in patients before the usual age for development of osteoporosis. The hypothesis for this study was that patients with laxity also have less strength during supination and pronation. An apparatus for measuring strength in supination and pronation was constructed and validated. 20 patients were chosen from a cohort of 76 patients who had had distal radial fractures 6 years ago. The stability of the DRU-joint was tested manually by 2 examiners and the test's reliability was good. The DRU-joint was lax in 6 patients. No differences were found between patients with stable and lax DRU-joints as regards isometric grip strength, strength in supination or pronation or radiographic characteristics. However, subjectively evaluated hand function was impaired in those with lax DRU-joints. This was noted on the subjective part of the Gartland and Werley score and 13 questions concerning everyday activities. In conclusion, DRU-joint laxity was associated with impaired hand function, but no loss of strength in forearm rotation after distal radial fractures in non-osteoporotic patients.