Purpose

The management of unreduced knee dislocations who present late is challenging. The aim of this study was to determine the clinical, radiological, and functional outcomes following open reduction and reconstructive surgery for chronic irreducible knee dislocations.

Methods

This retrospective study analysed prospectively collected data of patients with a chronic irreducible knee dislocation of 1 to 6 months duration, treated with open reduction, hinged external fixator application, and ligament reconstruction, who had a minimum two-year follow-up. Chronic knee dislocations with significant osteochondral loss or secondary degeneration, and pathological knee dislocations of non-traumatic origin were excluded. Patients were classified based on presence of prior peri-articular surgery, and direction of dislocation. Pre-treatment and post-treatment clinical, radiological, and functional knee scores data was analysed.

Results

21 patients of age range 19 to 43 years fulfilled all inclusion criteria. These included 13 missed dislocations and 8 neglected postoperative dislocations. There were 18 posterior and 3 anterior dislocations with no medial-lateral or complex rotatory dislocations. The mean follow-up was 6.9 years (range 2.7-16.2 years). On final follow-up, all 21 patients were independently ambulatory, with mean knee range of motion 127 degrees. No patient had symptomatic knee instability at final follow-up, despite 4 having isolated grade III PCL laxity. Anatomical reduction was achieved in 19 patients whereas 2 patients had incomplete joint reduction with a persistent grade II fixed posterior subluxation. Scanograms revealed coronal alignment within 5 degrees of the opposite unaffected limb in 17 patients. Mean functional scores improved from preoperative 9.4 (range 2-19) to postoperative 75.9 (range 64-95) for Lysholm, and preoperative 10.7 (range 8.3-13.7) to postoperative 73.5 (range 66.7-88.7) for KOOS. Prior periarticular surgery was associated with significantly inferior Lysholm scores (p value = 0.0341). Although 23.8% knees developed post-traumatic knee arthritis, no patient had undergone a conversion to knee arthroplasty or arthrodesis till latest follow-up.

Conclusion

Open reduction and reconstructive surgery is an effective surgical treatment for chronic irreducible knee dislocations of up to 6 months duration. An individualized, often staged, approach that prioritises joint reduction, early knee mobilization, and knee stability, ensures satisfactory clinical, radiological, and functional outcomes in the medium-term.