Background: Incompetence of the anterior cruciate ligament (ACL) confers knee laxity in the sagittal and axial planes that is measurable with clinical examination and diagnostic imaging. Hypothesis: An ACL-deficient knee will produce a more vertical orientation of the lateral collateral ligament (LCL), allowing for the entire length of the LCL to be visualized on a single coronal slice (coronal LCL sign) on magnetic resonance imaging. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: Charts were retrospectively reviewed from April 2009 to December 2017 for all patients treated with ACL reconstruction (constituting the ACL-deficient cohort). A control cohort was separately identified consisting of patients with a normal ACL and no pathology involving the collateral ligaments or posterior cruciate ligament. Patients were excluded for follow-up <2 years, incomplete imaging, and age >19 years. Tibial translation and femorotibial rotation were measured on magnetic resonance images, and posterior tibial slope was measured on a lateral radiograph of the knee. Imaging was reviewed for the presence of the coronal LCL sign. Results: The 153 patients included in the ACL-deficient cohort had significantly greater displacement than the 70 control patients regarding anterior translation (5.8 vs 0.3 mm, respectively; P < .001) and internal rotation (5.2° vs −2.4°, P < .001). Posterior tibial slope was not significantly different. The coronal LCL sign was present in a greater percentage of ACL-deficient knees than intact ACL controls (68.6% vs 18.6%, P < .001). The presence of the coronal LCL sign was associated with greater anterior tibial translation (7.2 vs 0.2 mm, P < .001) and internal tibial rotation (7.5° vs –2.4°, P = .074) but not posterior tibial slope (7.9° vs 7.9°, P = .973) as compared with its absence. Multivariate analysis revealed that the coronal LCL sign was significantly associated with an ACL tear (odds ratio, 12.8; P < .001). Conclusion: Our study provides further evidence that there is significantly more anterior translation and internal rotation of the tibia in the ACL-deficient knee and proves our hypothesis that the coronal LCL sign correlates with the presence of an ACL tear. This coronal LCL sign may be of utility for identifying ACL tears and anticipating the extent of axial and sagittal deformity.

IV.

Background: Previous meta-analyses have demonstrated superior outcomes in patients undergoing arthroscopic repair of medial meniscus posterior root tears (MMPRTs) compared with meniscectomy. However, these analyses have considered only short- or midterm outcomes and low-quality evidence. Purpose: To compare the mid- to long-term rates of radiographic osteoarthritis (OA) between repair and meniscectomy for MMPRT. Study Design: Systematic review and meta-analysis; Level of evidence, 4. Methods: PubMed, EMBASE, Ovid/MEDLINE, and Cochrane Central Register of Controlled Trials databases were queried for articles evaluating repair and meniscectomy for MMPRT. Articles were eligible if they had a minimum mean 4-year follow-up for radiographic OA or conversion to total knee arthroplasty (TKA) and were at least level 3 evidence. Radiographic OA was assessed using Kellgren-Lawrence (KL) progression. Rates of conversion to TKA and International Knee Documentation Committee (IKDC) scores were also extracted. DerSimonian-Laird binary random-effects models were created to evaluate differences in radiographic OA and TKA conversion rates, with odds ratios (ORs) representing pooled estimates. Continuous random-effects models with standardized mean differences (SMDs) were used to compare postoperative IKDC scores. Results: Repair and meniscectomy cohorts were followed for a mean of 64.8 months and 62.5 months, respectively, for KL progression; and 82.8 months and 73.8 months, respectively, for TKA rates and IKDC scores. Overall, 59 of 144 (41%) patients undergoing surgical intervention for MMPRT demonstrated OA progression; 18 of 82 (22%) who underwent repair for MMPRT exhibited OA progression compared with 41 of 62 (66%) who underwent meniscectomy (OR, 0.17; 95% CI, 0.03-0.83; P = .029). Overall, 30 of 143 (21%) patients converted to TKA; 9.8% (8/82) of patients who underwent repair converted to TKA (range, 47-131 months), while 36% (22/61) who underwent meniscectomy converted to TKA (range, 17.8-101 months) (OR, 0.15; 95% CI, 0.05-0.44; P < .001). No significant differences between postoperative IKDC scores were observed (SMD, 0.51; 95% CI, -0.02 to 1.05; P = .06). Conclusion: Medial meniscus posterior root repair results in significantly lower rates of radiographic OA progression and conversion to TKA at >60-month follow-up. On the basis of these findings, we recommend consideration of repair of MMPRTs when degenerative changes are not severe, as it can yield improved outcomes.

Background: Significant short-term improvements in function and pain after arthroscopic management of femoroacetabular impingement syndrome (FAIS) have been demonstrated regardless of mass index (BMI). No studies have reported the influence of obesity on mid- to long-term outcomes. Purpose: To evaluate the effect of BMI class on 5-year patient outcomes after arthroscopic treatment of FAIS. Study Design: Cohort study; Level of evidence, 3. Methods: A retrospective review of a prospective database was performed to identify patients who underwent arthroscopic treatment for FAIS. A matched-pair analysis for age and sex was performed in a 1:1:2:3 fashion for morbidly obese (BMI ≥35), obese (BMI = 30-34.9), overweight (BMI = 25-29.9), and normal weight (BMI = 18.5-24.9) patients, respectively. Patient characteristics, imaging, Hip Outcome Score Activities of Daily Living (HOS-ADL) and Sports Subscale (HOS-SS) scores, modified Harris Hip Score (mHHS), and pain scores were recorded preoperatively, with the same outcome scores recorded at 5 years postoperatively, along with satisfaction scores. Standardized modern hip arthroscopy, with labral repair, acetabuloplasty, femoroplasty, and capsular plication followed by formalized rehabilitation, was performed for all patients. Absolute outcomes along with change in outcomes were assessed between BMI groups. A between-group analysis was also conducted evaluating achievement of the minimal clinically important difference (MCID), patient acceptable symptomatic state (PASS), and substantial clinical benefit (SCB) for any outcome score. A multivariable analysis was additionally included to evaluate outcomes adjusting for known confounding variables. Results: A total of 140 patients with mean follow-up of 62.1 ± 6.5 months were identified: 20 morbidly obese, 20 obese, 40 overweight, and 60 normal weight. There were significant improvements for HOS-ADL, HOS-SS, and mHHS scores in the normal (all P < .0001) and overweight groups (all P < .0001), mHHS in the obese group ( P = .0275), and no significant improvement in functional scores in the morbidly obese group ( P > .05). Compared with normal controls, multivariable analysis, adjusting for confounders, showed similar improvement in HOS-ADL for patients in the overweight and obese groups, HOS-SS for patients in the overweight group, and mHHS for patients in the overweight and obese groups (all P > .05). All groups showed significant improvement in pain scores (all P < .01) that were not significantly different between groups in multivariable analysis (all P > .05). Obese BMI was associated with a 54.9-point decrease in 5-year HOS-SS, and morbidly obese BMI was associated with a 27.3, 35.0, and 23.7-point decrease in 5-year HOS-ADL, HOS-SS, and mHHS, respectively (all P < .05). Regarding surgical benefit in comparison with normal weight patients, patients in the overweight and obese groups were as likely to achieve MCID (reciprocal odds ratio [ROR]: 1.5 and 1.2, respectively, both P > .05), but patients in the morbidly obese group were not. All groups were significantly less likely than the normal weight group to achieve PASS (ROR: overweight 5.2, obese 14.1, morbidly obese 13.0; all P < .05) and SCB (ROR: overweight 3.9, obese 7.8, morbidly obese 20.3; all P < .05). Conclusion: There were significant improvements in at least 1 outcome score across all BMI groups with arthroscopic treatment of FAIS. While the normal weight patients demonstrated universal improvement in all patient-reported outcomes and significantly greater likelihood of achieving PASS and SCB, the higher BMI groups still demonstrated significant improvement in function and pain, except for the morbidly obese group. Patients with morbid obesity demonstrated long-term pain improvement, although they did not experience functional improvement.