The prognostic value of radiologic parameters for long-term outcome assessment after an isolated unilateral calcaneus fracture.

OBJECTIVE

The current retrospective case-control study examines the prognostic value of radiologic parameters for long-term clinical outcome assessment after a calcaneus fracture.

METHODS

In the authors' trauma department 262 adult patients with an isolated calcaneus fracture were treated from 1995 to 2005. Using conventional x-ray and computed tomography imaging. the calcaneal fractures were classified according to Sanders system. In addition, Boehler's and Gissane's angles were measured before and after therapy and the Larsen stage of subtalar arthrosis was determined. After a mean follow-up interval of 9.5 years, 44 patients were available for clinical and radiological assessment.

RESULTS

At the time of trauma the average age of the study group was 52 (range, 29-79) years. Thirty-seven patients were treated operatively and seven conservatively. Patients with a negative Boehler's angle, upon admission, exhibited significantly worse results using four of the five clinical scoring systems than patients with a preserved or slight reduced Boehler's angle. Operative treatment in patients whose Boehler's angle was elevated to normal range or beyond exhibited %worse better results than patients with an over-correction of Boehler's angle. In 11 cases, two primary and nine secondary subtalar arthrodeses were performed. The degree of subtalar arthrosis as per Larsen was increased 2.54 ± 1.14 in the course of hospital admission, arthrodesis and/or follow up examination. The results show no significant difference between operative and conservative treatment.

CONCLUSIONS

Boehler's angle at time of admission appears to be a valuable prognosticator for functional long-term results after calcaneus fracture. An operative over-correction of a reduced Boehler's angle should be avoided.