Background: A description of the precise locations of ligamentous and myotendinous injury patterns of acute posterolateral corner (PLC) injuries and their associated osseous and neurovascular injuries is lacking in the literature. Purpose: To characterize the ligamentous and myotendinous injury patterns and zones of injury that occur in acute PLC injuries and determine associated rates of peroneal nerve palsies and vascular injuries, as well as fracture and dislocation. Study Design: Case series; Level of evidence, 4. Methods: We retrospectively identified all patients treated for an acute multiligament knee injury (MLKI) at our level 1 trauma center from 2001 to 2018. From this cohort, all patients with PLC injuries were identified. Demographics, involved ligaments and tendons, neurovascular injury, and presence of fracture and dislocation were compared with the larger multiligament knee cohort. Incidence and location of injury of PLC structures—from proximal to midsubstance and distal injury—were recorded. Results: A total of 100 knees in 100 patients were identified as having MLKIs. A total of 74 patients (74%) had lateral-sided ligament injuries. Of these, 23 (31%) had a peroneal nerve palsy associated with their injury; 10 (14%), a vascular injury; and 23 (31%), a fracture. Patients with PLC injuries had higher rates of peroneal nerve injury as compared with those having acute MLKIs without a PLC injury (31% vs 4%; P = .005). Patients with a complete peroneal nerve palsy (n = 17) were less likely to regain function than those with a partial peroneal nerve palsy (n = 6; 12% vs 100%; P < .0001). Complete injury to the lateral collateral ligament (LCL) occurred in 71 of 74 (96%) PLC injuries, with 3 distinct patterns of injury demonstrated. Fibular avulsion of the LCL was the most common zone of injury (65%), followed by femoral avulsion (20%) and midsubstance tear (15%). Location of injury to the LCL was associated with the rate of peroneal nerve injury, with midsubstance tears and fibular avulsions associated with higher rates of peroneal nerve injury. Conclusion: MLKIs with involvement of the PLC are more likely to suffer peroneal nerve injury. The LCL is nearly always involved, and its location of injury is predictive of peroneal nerve injury. Patients with a complete peroneal nerve palsy at presentation are much less likely to regain function.

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.

Background Musculoskeletal urgent care centers are a new development in the urgent care landscape. Anecdotally, these centers are known to screen patients based on their insurance status, denying care to those with Medicaid insurance. It is important to know whether the practice of denying musculoskeletal urgent care to patients with Medicaid insurance is widespread because this policy could exacerbate existing musculoskeletal healthcare disparities. Questions/purposes (1) Do musculoskeletal urgent care centers in Connecticut provide access for patients with Medicaid insurance? (2) Do musculoskeletal urgent care centers have the same Medicaid policies as the entities that own them? (3) Are musculoskeletal urgent care centers more likely to be located in affluent neighborhoods? Methods An online search was conducted to create a list of musculoskeletal urgent care centers in Connecticut. Each center was interviewed over the telephone using a standardized list of questions to determine ownership and Medicaid policy. Next, the entities that owned these musculoskeletal centers were called and asked the same questions about their Medicaid policy. Medicaid policy was compared between musculoskeletal urgent care centers and the practices that owned them. The median household income for each ZIP code containing a musculoskeletal urgent care center was compared with the median household income for Connecticut. The median household income was also compared between the ZIP codes of musculoskeletal urgent care centers that accepted or denied patients with Medicaid insurance. Results Of the 29 musculoskeletal urgent care centers in Connecticut, only four (13%) accepted patients regardless of their insurance type, 19 (66%) did not accept any form of Medicaid insurance, and six (21%) required that certain requisites and stipulations be met for patients with Medicaid insurance to receive access, such as only permitting a patient for an initial visit and then referring them to a local hospital system for all future encounters, or only permitting patients with Medicaid insurance who lived in the same town as the clinic. All 29 musculoskeletal urgent care centers were owned by private practice groups and nine of 14 of these groups had the same policy towards patients with Medicaid insurance as their respective musculoskeletal urgent care centers. All 29 musculoskeletal urgent care centers were co-located in a private practice clinic office. Musculoskeletal urgent care centers were located in areas with greater median household incomes than the Connecticut state median (95% CI, USD 112,322 to USD 84,613 versus the state median of USD 73,781; p = 0.001). Conclusions Most musculoskeletal urgent care centers in Connecticut do not accept patients with Medicaid insurance and have similar or stricter Medicaid policies as the groups that own them. Additionally, musculoskeletal urgent care centers were located in affluent neighborhoods. These findings are important because they suggest private practices are using musculoskeletal urgent care centers to capture patients with more favorable insurance. This is likely a result of the relatively low Medicaid reimbursement rates in Connecticut and reflects a need for an increase in either reimbursement or incentives to treat patients with Medicaid insurance. The financial impact of capturing well-insured patients from public and academic medical centers and directing Medicaid patients to these urgent care centers is not known. Additionally, although most of these 29 musculoskeletal urgent care clinics denied care to patients with Medicaid, the specific healthcare disparities caused by decreased access to care must be further studied.