Summary

This study evaluates the long-term effects of multi-ligament reconstruction for knee dislocation, revealing stable functional outcomes after three years but significant progression of osteoarthritis in the patellofemoral compartment and in patients with initial cartilage damage.

Abstract

Background

The long-term outcomes of multi-ligament reconstructions (MLR) for knee dislocation (KD) remain unclear, with concerns about rapid progression to osteoarthritis (OA) and limited data on the ability to sustain sports and work activities.

Purpose

This study aims to assess the long-term sustainability of patient-reported outcome measures (PROMs), return to work (RTW), return to sport (RTS), and the detailed progression of OA in patients who underwent MLR following KD.

Methods

A prospective cohort study was conducted on 41 patients with Schenck grade III or higher KD who underwent MLR between 2013 and 2020, without loss to follow-up. Evaluations occurred at three time points: injury (T0), early post-injury (T1, mean 2.9 years), and late post-injury (T2, mean 6.6 years). PROMs, including IKDC, ACL-RSI, and KOOS, as well as RTW and RTS, were analyzed. Work activities were categorized as sedentary or manual using Saltin-Grimby scale while sports participation was categorized into four levels per the IKDC scale. OA progression was assessed through diagnostic arthroscopy (Outerbridge [OB] grade >2, lesion size >1 cm²) at T0, weight-bearing radiographs (Kellgren-Lawrence [KL] grade ≥2) at T1 and T2, and MRI (Modified Outerbridge Classification [MOC] grade >2) at T2. Statistical analysis included paired t-tests for continuous variables and Chi-squared tests for categorical variables.

Results

The cohort (age 38.9 ± 11.1 years, 78% male, BMI 26.3 ± 5.2 kg/m²) included KD III (61%), KD IV (17%), and KD V (22%) cases. No significant differences were observed in PROMs between T1 and T2, including all KOOS subscales. Participation in IKDC level 1 and 2 sports significantly decreased from 83% at T0 to 29% at T1 (p = 0.01) and remained stable at T2, while level 3 sports participation increased from 7% at T0 to 49% at T1 (p<0.01) and remained stable thereafter. Professional reorientation was significantly more common among manual laborers (33%) compared to sedentary workers (4%) (p = 0.001), with the proportion of manual laborers decreasing from 37% at T0 to 24% at T1 and remaining unchanged at T2. At T0, 51% had OB grade >2 cartilage damage; radiographic OA (KL ≥2) was observed in 53% at T1, with minimal progression to 56% at T2. OA progression was most pronounced in the patellofemoral compartment, increasing from 25% at T0 to 47% at T1 and 55% at T2 (p = 0.045), while no significant changes were observed in the medial (25% at T2) and lateral (15% at T2) compartments. Patients with initial traumatic cartilage damage (T0) were at higher risk for MOC > grade 2 lesions at T2 in the same compartment (OR = 6; 95% CI: 4.0–9.0, p < 0.001).

Conclusion

This study highlights that the long-term sustainability of functional outcomes following multi-ligament reconstruction for knee dislocation is generally achieved within the first three years post-injury, with minimal further deterioration observed thereafter. Osteoarthritis progression is the most pronounced in the patellofemoral compartment and in cases with initial cartilage damage.