Increased Neurovascular Morbidity Is Seen in Documented Knee Dislocation Versus Multiligamentous Knee Injury

Abstract

Background: The terms "knee dislocation" and "multiligamentous knee injury" (MLKI) have been used interchangeably in the literature, and MLKI without a documented knee dislocation has often been described as a knee dislocation that "spontaneously reduced." We hypothesized that MLKI with documented tibiofemoral dislocation represents a more severe injury than MLKI without documented dislocation. We aimed to better characterize the injuries associated with documented knee dislocations versus MLKIs without evidence of tibiofemoral dislocation.Methods: A total of 124 patients who were treated for an MLKI or knee dislocation to a single level-I trauma center between January 2001 and January 2020 were retrospectively reviewed. Patients were stratified into 2 groups, those with and those without a documented knee dislocation, and 123 of 124 patients were included in the analysis (78 in the nondislocated group and 45 in the dislocated group). Data regarding patient demographics, injury pattern, and associated neurovascular injury were collected and compared between groups.Results: Dislocated MLKIs, compared with non-dislocated MLKIs, had higher rates of peroneal nerve injury (38% versus 14%, respectively; p = 0.004), vascular injury (18% versus 4%; p = 0.018), and an increased number of medial-sided injuries (53% versus 30%; p = 0.009). There was no difference between dislocated and non-dislocated MLKIs in the number of bicruciate ligament injuries (82% versus 77%, respectively; p = 0.448), or lateral-sided injuries (73% versus 74%; p = 0.901).Conclusions: Dislocated MLKIs were found to have increased rates of neurovascular injury compared with nondislocated MLKIs, suggesting that knee dislocation and MLKI may not be synonymous in terms of associated injuries. Not all MLKIs are the result of a knee dislocation, and thus a documented tibiofemoral dislocation is a distinct entity that carries a greater risk of neurovascular compromise. We propose that these terms not be used interchangeably as previously described, and also that a high degree of vigilance must be maintained to evaluate for potential limbthreatening neurovascular injuries in any type of MLKI.

A proposal new classification in multi-ligament knee injuries based on both femorotibial joint and patellofemoral joint factors

“…Additionally, KD classi cation, Kennedy's classi cation, and SOFCOT 2008 classi cation are based on the presence of dislocation. MLKI without a documented knee dislocation has often been described as a knee dislocation that 'spontaneously reduced` [24]. It is di cult and confusing to apply these previous classi cations for the already reduced cases before consultation with the physician in the hospital.…”

Examining the Bone Bruise Patterns in Multiligament Knee Injuries With Peroneal Nerve Injury

“…Historically, ACL-sMCL injuries have not been included in MLKI studies, but the biomechanical importance of the PMC has been demonstrated, and therefore these more extensive medial-sided injuries were included in the present study. 17,18 Patients were then classified into subgroups based on the ligament injuries according to the Schenck classification 34 (Table 1).…”

“…If there was no radiographic evidence or a clinical note that documented visible deformity around the knee and no description of a reduction maneuver being performed, then the knee was not considered dislocated. 17,18…”

“…Multiligament knee injuries (MLKIs) are rare and devasting injuries that can be associated with neurovascular complications. 18,28 It is estimated that between 14% to 40% of patients with a MLKI experience concomitant common peroneal nerve (CPN) injury, 5,10,17,30 which confers a poorer prognosis than MLKIs without CPN injury. 5,7,19 Evaluation of CPN injuries is performed through multiple modalities that include physical examination, ultrasound, electromyography, and MRI findings.…”

Inclusion of open injuries in an updated Schenck classification of knee dislocations based on a global Delphi consensus study

“…A recent study has demonstrated that MLKIs with documented KDs have a significantly higher rate of vascular injuries in comparison to non-documented KDs with similar ligament injury patterns. 8 Most of the available literature on KDs constitutes a low level of evidence based on small cohort studies or underpowered prospective studies. 9 Furthermore, many classification systems still lack specificity and consistency to guide clinical decision making amongst surgeons.…”