Background: An increased posterior tibial slope (PTS) is a risk factor for primary anterior cruciate ligament (ACL) tears and graft failure, but the PTS has not been well-defined in those who have experienced bilateral ACL injuries. Purpose: The primary aim was to compare the PTS, as well as the rate of an elevated PTS (>12° on lateral radiography; >7° on magnetic resonance imaging [MRI]), between patients who have undergone bilateral ACL reconstruction (ACLR) versus unilateral ACLR. A secondary purpose was to examine whether these associations remained consistent on both plain radiography and MRI. Study Design: Cross-sectional study; Level of evidence, 3. Methods: We retrospectively identified patients who underwent primary ACLR at our institution from the years 2012 to 2020. Patients who underwent nonsimultaneous bilateral ACLR (n = 53) were matched to those who underwent unilateral ACLR (n = 53) by age, sex, and body mass index. Exclusion criteria were rotated lateral radiographs, MRI scans of inadequate quality, and concomitant ligament injuries or fractures. Those who had undergone unilateral ACLR with 12° was 41.0% compared with 13.2% in the unilateral group ( P = .012). The bilateral group had a significantly higher rate of an LPTS >7° compared with the unilateral group (53.8% vs 32.1%, respectively; P = .016) but not for an MPTS >7° ( P = .190). On MRI, the LPTS (6.90°± 2.73°) was significantly greater than the MPTS (4.41°± 2.92°) ( P < .001). There was a weak correlation between MPTS and radiographic PTS measurements ( R = 0.24; P = .021), but LPTS and radiographic PTS measurements were not significantly correlated ( R = 0.03; P = .810). Conclusion: Patients who underwent bilateral ACLR had a significantly greater PTS on radiography and a significantly greater LPTS on MRI compared with those who underwent unilateral ACLR. The rate of a radiographic PTS >12° was 2.4 times greater among patients undergoing bilateral ACLR compared with those undergoing unilateral ACLR. PTS measurements on radiography demonstrated a weak to negligible correlation with PTS measurements on MRI, suggesting that future normative PTS values should be reported specific to the imaging modality.
23 May 2023 in Knee Surgery, Sports Traumatology, Arthroscopy
Background: Previous research has found that the incidence of neurovascular injury is greatest among multiligamentous knee injuries (MLKIs) with documented knee dislocation (KD). However, it is unknown whether there is a comparative difference in functional recovery based on evidence of a true dislocation. Purpose: To determine whether the knee dislocation-3 (KD3) injury pattern of MLKI with documented tibiofemoral dislocation represents a more severe injury than KD3 MLKI without documented dislocation, as manifested by poorer clinical outcomes at long-term follow-up. Study Design: Cohort study; Level of evidence, 3. Methods: A multicenter retrospective cohort study was performed of patients who underwent surgical treatment for KD3 MLKI between May 2012 and February 2021. Outcomes were assessed using the International Knee Documentation Committee (IKDC) score, Lysholm score, Tegner activity scale, and visual analog scale (VAS) for pain. Documented dislocation was defined as a radiographically confirmed tibiofemoral disarticulation, the equivalent radiology report from outside transfer, or emergency department documentation of a knee reduction maneuver. Subgroup analysis was performed comparing lateral (KD3-L) versus medial (KD3-M) injuries. Multivariable linear regression was conducted to determine whether documented dislocation was predictive of outcomes. Results: A total of 42 patients (25 male, 17 female) were assessed at a mean 6.5-year follow-up (range, 2.1-10.7 years). Twenty patients (47.6%) were found to have a documented KD; they reported significantly lower IKDC (49.9 vs 63.0; P = .043), Lysholm (59.8 vs 74.5; P = .023), and Tegner activity level (2.9 vs 4.7; P = .027) scores than the patients without documented dislocation. VAS pain was not significantly different between groups (36.4 vs 33.5; P = .269). The incidence of neurovascular injury was greater among those with documented dislocation (45.0% vs 13.6%; P = .040). Subgroup analysis found that patients with KD3-L injuries experienced a greater deficit in Tegner activity level than patients with KD3-M injuries (Δ: –3.4 vs −1.2; P = .006) and had an increased incidence of neurovascular injury (41.7% vs 11.1%; P = .042). Documented dislocation status was predictive of poorer IKDC (β = −2.15; P = .038) and Lysholm (β = −2.85; P = .007) scores. Conclusion: Patients undergoing surgical management of KD3 injuries with true, documented KD had significantly worse clinical and functional outcomes than those with nondislocated joints at a mean 6.5-year follow-up. The current MLKI classification based solely on ligament involvement may be obscuring outcome research by not accounting for true dislocation.
Purpose: Arthroscopic Bankart repair (ABR) may be more effective than nonoperative management for patients with anterior shoulder instability following first-time dislocation. The purpose of the study was to determine the most cost-effective treatment strategy by evaluating the incremental cost-effectiveness ratio (ICER) for ABR versus nonoperative treatment. Methods: This cost-effectiveness study utilized a Markov decision chain and Monte Carlo simulation. Probabilities, health utility values, and outcome data regarding ABR and nonoperative management of first-time shoulder instability derived from level I/II evidence. Costs were tabulated from Centers for Medicaid & Medicare Services. Probabilistic sensitivity analysis was performed using >100,000 repetitions of the Monte Carlo simulation. A willingness-to-pay (WTP) threshold was set at $50,000. Results: The expected cost for operative management higher than nonoperative management ($32,765 vs $29,343). However, ABR (5.48 quality-adjusted life years (QALYs)) was the more effective treatment strategy compared to nonoperative management (4.61 QALYs). The ICER for ABR was $3943. Probabilistic sensitivity analysis showed that ABR was the most cost-effective strategy in 100% of simulations. Discussion: ABR is more cost-effective than nonoperative management for first-time anterior shoulder dislocation. The threshold analysis demonstrated that when accounting for WTP, ABR was found to be the more cost-effective strategy.