Working Diagnosis:
High energy traumatic knee dislocation resulting in complex Multi-ligament Knee Injury with ACL tear and severe blowout injury of all medial sided knee structures

Treatment:
Knee was immobilized and patient transported to the ED. Imaging revealed MLKI as above. ABI and CT-A showed no evidence of vascular injury. Patient completed 1 week of PT pre-operatively to optimize ROM and swelling.
Eleven days post-injury, he underwent Right knee open superficial MCL reconstruction with hamstring autograft, deep MCL repair, posterior lateral corner repair, medial meniscus repair and arthroscopy with arthroscopic-assisted ACL reconstruction with patella tendon autograft.

Outcome:
Post-operative rehab was initiated on POD #1. He was non-weight bearing in a knee immobilizer for 6 weeks then transitioned to a hinged knee brace and gradually weaned off crutches. He was able to fully weight-bear at 8 weeks then progressed through a strengthening program. He was cleared to return to play after he achieved a quadriceps index >90% and passed functional sports test.

Author's Comments:
Knee dislocation is an orthopedic emergency requiring prompt identification, reduction, and transfer to a trauma center for full evaluation. Requiring disruption of at least 2 major ligaments, knee dislocation often leads to concomitant meniscal, chondral and neurovascular damage. Popliteal artery disruption is a critical complication that requires emergent assessment, as failure to restore arterial flow within 8 hours may result in limb ischemia and amputation. Following acute management, patient outcomes are optimized by early single-stage knee ligament reconstruction within 3 weeks of injury followed by immediate postoperative rehabilitation emphasizing early mobility and graft protection.

Editor's Comments:
Knee dislocations occur as a result of a high velocity injury to the knee. They are a rare occurrence accounting for only 0.02% of all orthopedic injuries. However, they are thought to be under-reported and un-diagnosed as up to 50% may resolve spontaneously. Most commonly the tibia dislocates anteriorly (30-50%), followed by posteriorly (30-40%), laterally (13%), medially (3%), and rotational (5%). Rotational is a posterior lateral dislocation noted by buttoning of the skin as the medial femoral condyle through the capsule. These dislocations are usually irreducible without anesthesia.
Reduction should be attempted immediately. Gentle traction while gentle extending the knee is usually sufficient to achieve reduction. Never apply manual pressure especially to the posterior fossa to attempt to reduce the knee as this increases risk of neurovascular compromise. Patients should be splinted in 20-30 degrees of flexion and transported for further evaluation.
Vascular injury occurs commonly due to injury to the popiteal artery or due to compartment syndrome. In the literature, ranges from 5-65%, and larger studies have the incidence around 20%. Vascular status should be monitored with serial exams. ABIs are useful with a cutoff of 0.9 warranting further evaluation. Because injury could be subtle to the subintimal, some experts recommend angiography (CTA or MRA) for every suspected knee dislocation. In patients with arterial injury, the risk of subsequent amputation is significantly higher if not treated within 8 hours.
Nerve injury occurs in 4.5-40% of cases, so a detailed neurologic exam of both sensory and motor function of the foot and ankle is necessary. The common peroneal nerve is most commonly injury though isolated tibial nerve and superficial peroneal nerve injuries have been reported.
In younger and more active patient, surgical treatment is recommended. There is some debate as to the optimal surgery technique (reconstruction, direct repair, verses non-repair for the various ligamentous structures) and timing (early open repair

References:
1. Bakshi NK, Khan M, Lee S, et al. Return to Play After Multiligament Knee Injuries in National Football League Athletes. Sports Health. 2018;10(6):495-499. doi:10.1177/1941738118768812
2. Lachman JR, Rehman S, Pipitone PS. Traumatic Knee Dislocations: Evaluation, Management, and Surgical Treatment. Orthop Clin North Am. 2015;46(4):479-493. doi:10.1016/j.ocl.2015.06.004
3. Edginington and Taylor. 5-1-2020. Knee dislocations. https://www.orthobullets.com/trauma/1043/knee-dislocation

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