Use of a hinged external knee fixator after surgery for knee dislocation

PURPOSE: This study documents short-term clinical outcomes in patients with knee dislocations after blunt trauma and evaluates the compass knee hinge (CKH) external fixator for their treatment. TYPE OF STUDY: Nonrandomized prospective functional outcome study. METHODS: Forty patients with 43 knee dislocations were evaluated. Twelve knees underwent ligament reconstruction followed by placement of a CKH; this was group A. Group B included 27 knees that underwent the same treatment and rehabilitation protocol except that an external brace was used rather than a CKH. RESULTS: Thirty-six patients with 39 knee dislocations underwent follow-up ranging from 14 to 41 months (mean, 24). Four patients with 4 knee dislocations were lost to follow-up (1 group A, 3 group B). Group A underwent 27 knee ligament procedures with 2 (7%) failures based on clinical examination. Group B underwent 102 ligament procedures with 30 (29%) failures (P <.05). Anterior cruciate ligament (ACL) reconstruction revealed that 7 group A patients experienced 1 (14%) failure and 25 Group B patients experienced 7 (28%) failures. Posterior cruciate ligament (PCL) reconstruction in 7 group A patients included no failures, and 20 PCL reconstructions in group B included 1 failure. Reconstruction of the posterolateral corner (PLC) yielded no failures in 2 group A patients and 5 (25%) of 20 in group B. Repair of 8 PLCs in group A yielded 1 (12.5%) failure and 26 PLC repairs in group B had 14 (54%; P =.05). SF-36 data revealed low mean values with no significant differences between groups with current enrollment. CONCLUSIONS: Knee dislocation after blunt trauma requires aggressive surgical treatment and physical therapy. In the short-term evaluation, the CKH allows aggressive physical therapy without placing repaired or reconstructed ligaments under high stresses that can result in failure.