Summary

Knee dislocation(KD) with a peri-articular fracture, classified as KD-V (Schenck Classification), is a rare and Modified Schenck classification system does not describe the site and type of peri-articular fracture. With increase incidence of these complex injuries,There are no available guidelines for treatment(single stage/multiple stages).Novel classification needed for comprehensive management.

Abstract

Background

The knee dislocation(KD) with a peri-articular fracture, classified as KD-V (Schenck Classification), is a rare form of knee injury. Modified Schenck classification system does not describe the site and type of peri-articular fracture. There are no available guidelines for treatment(single stage vs multiple stages) of these complex knee injuries.

Methods

This is a retrospective case series of 14 patients with KD-type V of a total of 112 patients with multi-ligamentous injuries(MLKI) were treated during 2019 to 2022. 12 injuries resulted from high-velocity trauma due to road traffic accidents (RTAs), 1 had fall from height and 1 sustained direct contact injury due to fall of heavy object on the knee. Patients with frank dislocation underwent closed reduction in the emergency room. Patients with stable knees post-reduction were immobilized with knee brace for 48 hours and closely monitored for signs of vascular compromise and compartment syndrome. Timing of surgery was determined based on factors such as swelling, soft tissue condition, range of motion(ROM), capsule integrity(MRI), neurovascular status, and any concurrent medical conditions. Once the swelling subsided, patients were planned for definitive operative intervention. Two patients, due to unstable reduction, required immobilization with an external fixator. External fixator was removed after three weeks, Ligament reconstruction was performed using tendon autografts (hamstring or peroneus) or allografts. Following management of intra-articular injuries, peri-articular fracture was definitively fixed with implants (cannulated cancellous screws/plates) depending on fracture pattern. Functional outcomes were assessed by pre-operative and post-operative knee knee range of motion(ROM,IKDC,Lysholm score and amount of laxity based on stress x-rays. Friedman test was applied to compare pre-operative and post-operative clinical scores.Novel classification complex MLKI with rim fractures of tibial plateau or tibial condyle fractures with knee dislocation.

Results

Mean age of patients was32.07 +/- 12.96(17–53yrs), with male-to-female ratio-11:3. Majority of injuries(12) were due to high-velocity road traffic accidents. Average tourniquet time was 85.57 minutes(61–118minutes). Mean post-operative Lysholm score at final follow-up was 84.4, and mean IKDC score was71.6. Mean ROM at the final follow-up was112°. Statistical analysis revealed significant improvements in both pre-operative versus post-operative functional scores and post-operative versus final follow-up scores(p < 0.05). The mean anterior tibial translation in patients with ACL reconstruction was found to be3.13+/-1.44. mean posterior tibial translation in patients with PCL reconstruction was found to be1.63+/-0.47. Mean valgus opening at 0° and30° knee flexion in patients with MCL injury after conservative/repair was found to be3.4+/-1.94 and 2.49+/-1.14 respectively. Mean varus opening in patients with LCL injury after conservative/reconstruction was found to be5.73+/-2.16 and 6.6+/-1.94 respectively. Three patients developed post-operative stiffness at three weeks; these patients underwent manipulation under anaesthesia followed by continuous passive motion exercises, achieving 90° knee ROM by two months post-operatively. Four patients experienced superficial infections, which were managed with oral antibiotics. No patients experienced reconstruction failure or required revision surgery.Novel classification MLKI with rim fractures of tibial plateau or tibial condyle fractures with knee dislocation.

Conclusion

Single-stage management of MLKI-KD-V with rim avulsion tibial plateau injuries yields satisfactory outcomes and facilitates an early return to pre-injury activity levels at follow up of 2 years. Multiple stage management of MLKI-KD-V with tibial plateau complex knee injuries needs comprehensive management of all MLKI-KD-V injuries based on a novel, easy-to-use and reproducible classification system.