Comparison of KD3-M and KD3-L Multiligamentous Knee Injuries and Analysis of Predictive Factors That Influence the Outcomes of Single-Stage Reconstruction in KD3 Injuries.

BACKGROUND

The knee dislocation-3 (KD3) injury pattern is the most common form of multiligamentous injury. Medial KD3 (KD3-M) and lateral KD3 (KD3-L) are 2 anatomically different varieties of this injury.

PURPOSE

To compare the surgical outcomes of KD3-M and KD3-L multiligamentous knee injury patterns and to determine the factors that could influence the outcomes after single-stage reconstruction.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A cohort of 45 patients with multiligamentous knee injuries (31 KD3-M, 14 KD3-L) who were operated on between 2011 and 2015 were compared. The cruciate ligaments were reconstructed, and the collateral ligaments were managed either conservatively or surgically depending on intraoperative laxity, tissue condition, injury site, and chronicity. The mean follow-up was 36 months (range, 24-72 months). The International Knee Documentation Committee (IKDC) score, Lysholm score, knee flexion range of motion (ROM), and laxity on stress radiographs were compared. Various factors likely to influence the outcomes were also analyzed.

RESULTS

The mean IKDC score, Lysholm score, and knee flexion ROM for the 45 patients were 74.74, 87.66, and 126.78°, respectively. There was no significant difference between the KD3-M and KD3-L groups in terms of the postoperative IKDC score ( = .768), Lysholm score ( = .689), knee flexion ROM ( = .798), and laxity on stress radiographs ( = .011). Patients with a transient dislocation had better outcomes (76.51, 89.41, and 128.61°, respectively) than those with a frank dislocation (67.62, 80.66, and 119.44°) ( = .037, .007, and .043). The acute group had better outcomes (77.00, 89.51, and 127.86°) when compared with the subacute (66.26, 86.00, and 121.00°) and chronic groups (67.40, 76.40, and 125.00°) ( = .045, .006, and .486). Regression analysis showed the influence of these factors on outcomes. The presence or absence of dislocations, time frame in which surgery was performed, and follow-up duration were found to influence the outcome. All other factors had no bearing on outcomes. Two patients had knee stiffness and underwent arthrolysis.

CONCLUSION

Despite anatomic and biomechanical differences between KD3-M and KD3-L injuries, single-stage management did not produce any significant difference in results. The presence of a frank dislocation, delay in surgery, and duration of follow-up were found to influence outcomes.