External fixator for treatment of the sub-acute and chronic multi-ligament-injured knee.

ABSTRACT

PURPOSE: To assess whether the use of an articulated external fixator provides improvements in the mobility, stability and subjective function of patients undergoing ligament reconstruction. METHODS: Thirty-three patients with sub-acute and chronic knee dislocation were subjected to multi-ligament reconstruction surgery. These patients were randomly allocated to two groups for immobilization after reconstruction group 0-control (18 patients), with rigid knee bracing, and group 1-articulated external fixator (15 patients). The stability of the reconstructed ligaments was assessed after at least 14 months (26.6-month average) postoperatively by physical examination. Deficit of extension and flexion was measured in relation to the unaffected contralateral knee, and the Lysholm knee scoring scale questionnaire was applied. RESULTS: There was no difference in the assessment of joint stability between the groups. In group 1, patients showed less flexion deficit (4.8° ± 5.4° vs. 18.2° ± 14.8°, p < 0.05), and the percentage of patients with a flexion deficit of 5° or less were higher compared with group 0 (64 vs. 18 %, p < 0.05). There was no difference between groups in relation to extension loss. Group 1 also presented better Lysholm scores, with 73 % of patients rated as excellent or good compared with 35 % in group 0 (p < 0.05). CONCLUSIONS: Compared with the control rehabilitation protocol with rigid knee bracing in extension, the use of an articulated external fixator in the treatment of chronic multi-ligament-injured knees provided the same ligament stability, better final range of motion and improved Lysholm score. Patients presenting with chronic multi-ligament instability should be considered for articulated external fixation to supplement reconstruction procedures. LEVEL OF EVIDENCE Randomized controlled trial, Level I.