We prospectively assessed the diagnostic accuracy
of the gravity stress test and clinical findings to evaluate the stability
of the ankle mortise in patients with supination–external rotation-type
fractures of the lateral malleolus without widening of the medial
clear space. The cohort included 79 patients with a mean age of
44 years (16 to 82). Two surgeons assessed medial tenderness, swelling
and ecchymosis and performed the external rotation (ER) stress test
(a reference standard). A diagnostic radiographer performed the
gravity stress test. For the gravity stress test, the positive likelihood ratio (LR)
was 5.80 with a 95% confidence interval (CI) of 2.75 to 12.27, and
the negative LR was 0.15 (95% CI 0.07 to 0.35), suggesting a moderate
change from the pre-test probability. Medial tenderness, both alone
and in combination with swelling and/or ecchymosis, indicated a
small change (positive LR, 2.74 to 3.25; negative LR, 0.38 to 0.47),
whereas swelling and ecchymosis indicated only minimal changes (positive
LR, 1.41 to 1.65; negative LR, 0.38 to 0.47). In conclusion, when gravity stress test results are in agreement
with clinical findings, the result is likely to predict stability
of the ankle mortise with an accuracy equivalent to ER stress test
results. When clinical examination suggests a medial-side injury,
however, the gravity stress test may give a false negative result. Cite this article:
External fixation of distal tibial fractures is often associated with delayed union. We have investigated whether union can be enhanced by using recombinant bone morphogenetic protein-7 (rhBMP-7). Osteoinduction with rhBMP-7 and bovine collagen was used in 20 patients with distal tibial fractures which had been treated by external fixation (BMP group). Healing of the fracture was compared with that of 20 matched patients in whom treatment was similar except that rhBMP-7 was not used. Significantly more fractures had healed by 16 (p = 0.039) and 20 weeks (p = 0.022) in the BMP group compared with the matched group. The mean time to union (p = 0.002), the duration of absence from work (p = 0.018) and the time for which external fixation was required (p = 0.037) were significantly shorter in the BMP group than in the matched group. Secondary intervention due to delayed healing was required in two patients in the BMP group and seven in the matched group. RhBMP-7 can enhance the union of distal tibial fractures treated by external fixation.
