Medial-Sided Injuries in the Multiple Ligament Knee Injury

Abstract

Multiligament knee injuries (MLKI) are complex and challenging to treat. The posteromedial corner (PMC) structures are commonly torn in MLKI. A thorough and systematic evaluation is imperative to avoid a missed diagnosis and for planning treatment. With several structures injured, the treatment method (operative vs. nonoperative, repair vs. reconstruction), availability of allografts, timing of surgery, and rehabilitation are some of the factors that have to be considered in the decision-making. Persistent valgus instability because of untreated or not healed medial collateral ligament (MCL) tears will increase graft forces on the cruciate ligament grafts, thus increasing the risk of reconstruction graft failure. In recent years, there has been a growing body of literature on the anatomy and biomechanics of the medial structures that has aided in the development of biomechanically and clinically validated anatomic PMC reconstructions. Despite good healing potential of the MCL, in MLKI, surgical treatment is recommended for grade III PMC injuries to aid early rehabilitation and reduce the risk of surgical failure. Several studies have reported satisfactory outcomes after surgical treatment of MLKI involving the medial side. Early functional rehabilitation is imperative to reduce the risk of arthrofibrosis.

Multiple Ligament Reconstructions of the Knee and Posterolateral Corner

“…1,7,12 Successful outcomes have been reported for both medial and lateral-sided multiligament knee injuries with consistent surgical approaches, with care taken to avoid tunnel convergence, passing and securing grafts in optimized order with correct positioning of the joint and appropriate rehabilitation. 35 The importance of a systematic and biomechanically and clinically validated approach to multiligament knee reconstruction cannot be understated; revision multiligament procedures frequently must contend with extensive scarring and osteolysis, loss of autograft because of previous harvest, arthrofibrosis, and a significant quantity of retained hardware. 36 Appropriate graft tensioning sequence is important to avoid overconstraint of the joint.…”

Medial soft-tissue complex of the knee: Current concepts, controversies, and future directions of the forgotten unit

“…Historically, it was reported to be attached to the medial epicondyle (ME). 16,21,23 Still, more recent publications [4][5][6][7]14,24 have identified a different attachment based on the findings of the seminal cadaveric study of LaPrade et al 15 These authors described the sMCL femoral insertion as being 3.2mm proximal and 4.8mm posterior to the ME. However, emerging studies published by the Imperial College London 1,18 demonstrated that the sMCL covers the ME, having the attachment centered 1-2mm proximal.…”

“…This traduces injury of the sMCL, dMCL, and POL, and possibly the ACL. 2,13,14,24,31,35 Lastly, the dial test can also diagnose pathology of the MSC if there is more than 5º of asymmetry in ER. The direction of the tibial subluxation differentiates it from an injury of PLC: posterolateral for PLC, anteromedial for MSC.…”

“…5,17 IMAGING ASSESSMENT Protocols should always include standard plain radiographs to exclude fractures, bony avulsions, and dislocations. 2,17,24 In chronic injuries, long leg films should be done to characterize the mechanical axis. 5,11,13,17,24 Bilateral stress x-rays under valgus load are reliable in quantifying instability: 3.2mm side-to-side difference of medial gap opening represents a complete sMCL tear, and ≥9.8mm insufficiency of all major structures of the MSC.…”

“…2,17,24 In chronic injuries, long leg films should be done to characterize the mechanical axis. 5,11,13,17,24 Bilateral stress x-rays under valgus load are reliable in quantifying instability: 3.2mm side-to-side difference of medial gap opening represents a complete sMCL tear, and ≥9.8mm insufficiency of all major structures of the MSC. 36 Although they provide important information in chronic cases, their use in the acute setting is very limited due to pain.…”