Posterior tibial slope angle in contact versus non-contact anterior cruciate ligament injuries.

BACKGROUND: Increased Posterior Tibial Slope (PTS) angle has been reported to be a risk factor for primary anterior cruciate ligament (ACL) tears. However, it is unknown whether increased PTS has an associated increased risk for non-contact versus contact ACL injury. PURPOSE: The purpose of this study is to determine whether patients with non-contact ACL injury have a higher PTS angle than those with contact ACL injury. METHODS: A total of 1700 patients who underwent primary ACL reconstruction between January 2011 and June 2023 at a single academic institution were initially included. Electronic medical records were reviewed for demographic information as well as evidence that the patient sustained a contact or non-contact ACL injury. Patients in the contact cohort were propensity score matched to patients in the non-contact cohort by age, sex and BMI. Additionally, patients in the contact cohort were then propensity score matched to a control group of patients with intact ACLs also by age, sex and BMI. RESULTS: One hundred and two patients with contact injury were initially identified and 1598 patients with non-contact injuries were identified. Of the 102, 67 had knee X-rays that were suitable for measurement. These 67 contact injury patients were propensity score matched to 67 noncontact patient and 67 patients with intact ACLs based on age, sex and BMI. There were no significant differences between contact and non-contact cohorts in age (28.7±6.3 vs. 27.1±6.5, p = 0.147), sex (Female: 36.0% vs. 34.3%, p = 0.858), or BMI (26.7±5.6 vs 26.1±3.4, p = 0.475). There was no significant difference in PTS angle between contact versus non-contact ACL injury patients (11.6±3.0 vs.11.6±2.8, p = 0.894). There was a significant difference in PTS between the contact ACL injury and the intact cohort (11.6±3.0 vs. 10.0±3.9, p = 0.010) and the non-contact ACL injury and the intact cohort (11.6±2.8 vs. 10.0±3.9, p = 0.010). CONCLUSION: There was no significant difference in the degree of PTS between patients who sustained contact versus non-contact ACL injuries. Additionally, there was a significantly increased PTS in both the contact and non-contact ACL injury cohorts compared to patients with intact ACLs.

MCP-1 in synovial fluid as a predictor of inferior clinical outcomes after meniscectomy.

PURPOSE: To evaluate knee intra-articular cytokine concentrations in patients undergoing isolated meniscectomy and determine if these concentrations are associated with clinical outcomes. METHODS: Concentrations of ten biomarkers were quantified in synovial fluid aspirated from the operative knees of patients who underwent isolated meniscectomy from 10/2011-12/2019. Patients completed a survey at final follow-upincluding VAS, Lysholm, Tegner, and KOOS Physical Function Short Form (KOOS-PS). Failure was defined as subsequent TKA or non-achievement of the Patient Acceptable Symptom State (PASS) for knee pain defined as VAS > 27/100. Regression analysis investigating the relationship between cytokine concentrations and failure was performed. RESULTS: The study consisted of 100 patients, including 50 males (50.0%) with a mean age of 51.1 ± 11.7 years, a median BMI of 28.9 kg/m2 [25.5, 32.4], and a mean follow-up of 8.0 ± 2.2 years. There were no demographic or clinical differences between failures (n = 41) and non-failures (n = 59) at baseline. Monocyte Chemotactic Protein 1 (MCP-1) concentration was significantly higher in failures than in non-failures (344.3 pg/ml vs. 268.6 pg/ml, p = 0.016). In a regression analysis controlling for age, sex, BMI, symptom duration, length of follow-up, and ICRS grade, increased MCP-1 was associated with increased odds of failure (p = 0.002). CONCLUSIONS: The concentration of MCP-1 on the day of arthroscopic meniscectomy was predictive of failure as defined by an unacceptable pain level at intermediate- to long-term follow-up. This finding may help identify patients at high risk for poor postoperative outcomes following isolated meniscectomy and serve as a target for future postoperative immunomodulation research.

Differential analysis of the impact of lesions' location on clinical and radiological outcomes after the implantation of a novel aragonite-based scaffold to treat knee cartilage defects.

PURPOSE: There is limited comparative evidence on patient outcomes following cartilage repair in various knee compartments. The aim of this study was to compare clinical and imaging outcomes after treating cartilage defects in femoral condyles and trochlea with either an aragonite-based scaffold or surgical standard of care (SSoC, i.e., debridement/microfractures) in a large multicentre randomized controlled trial. METHODS: 247 patients with up to three knee joint surface lesions (ICRS grade IIIa or above) in the femoral condyles, trochlea or both ("mixed"), were enrolled and randomized to surgery with either a cell-free aragonite scaffold or SSoC. Patients were followed for up to 48 months by analysing subjective scores (KOOS and IKDC), radiological outcomes (defect filling on MRI), as well as treatment failure rates and adverse events. A differential analysis of outcomes for condylar, trochlear and mixed lesions was performed. RESULTS: The scaffold group significantly outperformed the SSoC group regardless of lesion location with statistically significantly better KOOS Overall scores at 24 months (all p ≤ 0.0009) and 48 months (all p ≤ 0.02). Similar results were observed for KOOS subscales and IKDC scores. For KOOS responder rates, superiority of the implant group was demonstrated at 24, 36, and 48 months (all p ≤ 0.004). Higher defect filling on MRI for implants was observed for all locations. Lower treatment failure rates for the implant were observed in condylar and mixed lesions. CONCLUSION: The aragonite-based scaffold was safe and effective regardless of the defect location, providing superior clinical and radiological outcomes compared to SSoC up to four years follow-up. LEVEL OF EVIDENCE: I - Randomized controlled trial.

Characterization of bone marrow edema patterns among patients with Segond fracture in the setting of acute anterior cruciate ligament injury: A comparative MRI study.

PURPOSE: The purpose of this study is to investigate the anatomic distribution of bone marrow edema on MRI among patients who sustained a Segond fracture compared to those with an isolated ACL tear. METHODS: A retrospective cohort study was performed of patients aged 18-40 years old who presented with an acute isolated ACL tear between January 2012 and May 2022. Two blinded readers reviewed all knee MRIs to assess bone marrow edema using the Whole-Organ Magnetic Resonance Imaging Score and the area of each sub-compartment was scored. RESULTS: There were 522 patients in the final analysis, of which 28 patients (5.4%) were identified to have a Segond fracture. The Segond group demonstrated significantly greater rates of WORMS grades 2 and 3 in the central lateral femoral condyle, as well as the anterior, central, and posterior lateral tibial plateau. Furthermore, the Segond group demonstrated significantly greater rates of WORMS grades 2 and 3 in the central medial femoral condyle and the anterior medial tibial plateau. Bone edema at the central lateral femoral condyle (R = 0.034, p = 0.019) and central tibial plateau (R = 0.093, p = 0.033) were significantly correlated with lateral meniscus tears, while the edema in the posterior medial femoral condyle was correlated with medial meniscus tears (R = 0.127, p = 0.004). CONCLUSION: Patients who present with ACL tear and a concomitant Segond fracture demonstrate significantly more extensive bone marrow edema in both the medial and lateral compartments of the knee compared to patients with an isolated ACL tear.

Leukocyte-Poor Platelet-Rich Plasma as a Treatment for Patellar Tendinopathy A Multicenter, Randomized Controlled Trial.

PURPOSE: The purpose of this study was to compare regimens of eccentric exercise and dry-needling, with and without an ultrasound-guided leukocyte-poor platelet-rich plasma (LP-PRP) injection, in patients with patellar tendinopathy. METHODS: Patients with symptomatic patellar tendinopathy based on physical examination and magnetic resonance imaging and who had failed at least 6 weeks of nonoperative treatment were enrolled and randomized at two centers to receive ultrasound-guided dry-needling (DN) alone or in addition to an injection of LP-PRP coupled with standardized eccentric strengthening exercises. Participants completed patient-reported outcome surveys at baseline and at 3, 6, 9, 12, and 26 weeks post-treatment. The primary outcome measure was the Victorian Institute of Sports Assessment (VISA) score for patellar tendinopathy (VISA-P) at 12 weeks, and secondary measures included the visual analog scale (VAS) for pain, Tegner activity scale, Lysholm knee scale (Lysholm), and Veterans Rand 12-Item Health Survey (VR12) questionnaire at 12 and 26 weeks. RESULTS: Thirty-one subjects were enrolled in the study (15 DN, 16 LP-PRP). Twenty-three patients were available for follow-up at all time points. There were no statistically significant differences between the two groups at baseline. At 12 weeks post-treatment, both the LP-PRP and DN groups demonstrated statistically significant (p < 0.05) improvements from baseline with respect to Lysholm score (34.5 ± 15.1 and 31.7 ± 18.4), VAS pain scale (-1.58 ± 2.1 and -2.8 ± 1.9, respectively), and VISA score (19.2 ± 15.9 and 28.4 ± 19.4, respectively). At 26 weeks post-treatment both groups demonstrated statistically significant (p < 0.05) improvements in Lysholm score (23.6 ± 23.1 and 24.5 ± 17.3, respectively) and VAS pain score (-1.67 ± 2.3 and -2.18 ± 2.9, respectively). The LP-PRP group failed to show significance for VISA-P score from 0 to 26 weeks, though the DN group did (22.0 ± 14.6). There were no statistically significant differences between the two groups in mean VISA, VAS, Lysholm, or the Short Form Health Survey (SF-12) scores at either the 12 week or 26-week follow-up time points. CONCLUSION: The results of the current study demonstrate that both DN and DN plus LP-PRP are effective treatment options in the management of symptomatic patellar tendinopathy, however, LP-PRP did not add any additional improvement over DN alone.

The Effectiveness of Alpha-2-Macroglobulin Injections for Osteoarthritis of the Knee.

BACKGROUND: Intra-articular (IA) injections of plateletrich plasma (PRP) have been increasingly used in the nonoperative treatment of knee osteoarthritis (OA) but have considerable heterogeneity in both formulation and clinical results. Alpha-2-macroglobulin (A2M) is a large plasma protein found in PRP that inhibits cartilage-degrading enzymes and could be an efficacious OA treatment independently. The purpose of this study was to compare the short-term clinical efficacy of IA injection of A2M-rich PRP concentrate to conventionally prepared PRP and corticosteroids in the management of symptomatic knee OA. METHODS: This double-blinded, randomized, controlled clinical trial was conducted at a single medical center with enrollment from June 2018 to May 2019. Subjects with symptomatic Kellgren-Lawrence (KL) grade 2 or 3 knee OA were randomized to IA injection with A2M, PRP, or methylprednisolone (MP) and followed for 12 weeks post-injection. Knee pain and function were assessed at pre-treatment baseline and at 6-week and 12-week followup with patient-reported outcome (PRO) surveys including the visual analog scale (VAS) for pain, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS), Lysholm score, and Tegner score. RESULTS: Seventy-five subjects were enrolled in the trial, of whom 68 (90.7%) completed the 12-week follow-up. The majority of subjects (73%) were female with a mean age of 59 years (range: 37 to 75 years). There were no significant differences in age (p = 0.30), sex (p = 0.44), or KL grade (p = 0.73) between treatment groups. By 12 weeks postinjection, the A2M group showed significant improvement in VAS, WOMAC, KOOS, and Tegner (p < 0.05), the PRP group showed no significant improvement in any PROs (p > 0.05), and the MP group showed significant improvement in Lysholm only (p = 0.01). However, the changes in PRO scores between baseline and 12-week follow-up did not significantly differ between the three groups (p > 0.05). CONCLUSIONS: Alpha-2-macroglobulin IA injection shows comparable efficacy to PRP and corticosteroids in the treatment of mild-to-moderate knee OA. Alpha-2-macroglobulin treatment resulted in modest improvement in knee pain and function at 6-week follow-up, albeit inconsistently across PRO measures and to a similar degree as PRP and corticosteroids. Given its non-superior short-term efficacy compared to established IA injections, as well as its increased cost of preparation, A2M may not be a justifiable option for routine treatment of knee OA.

The Impact of Adding a Tibial Tubercle Osteotomy to Medial Patellofemoral Ligament Reconstruction in the Treatment of Patellar Instability.

BACKGROUND: An isolated medial patellofemoral ligament (MPFL) reconstruction (MPFLR) has been demonstrated to be an effective treatment option in the prevention of patellar instability, but there is growing support for performing a tibial tubercle osteotomy (TTO) in patients with an elevated tibial tubercle-trochlear groove distance. The purpose of this study was to evaluate the impact of adding a TTO to MPFLR on patient reported outcomes. METHODS: A retrospective review of patients who underwent MPFLR with or without TTO with a minimum of 12-month follow-up was performed. Patients in both groups were matched based on age, sex, and follow-up time. Recurrent instability (including re-dislocation and subluxation), visual analog scale (VAS) for pain score, Kujala score, and satisfaction were evaluated. RESULTS: There were 59 patients who underwent MPFLR with concomitant TTO performed at our institution and met our inclusion and exclusion criteria. These patients were then matched to patients undergoing isolated MPFLR based on demographics and follow-up time. The mean age was 25.0, 76.3% were female, and the mean follow-up time was 49 months. There was a significant difference in mean tibial tubercle-trochlear groove distance (19.8 ± 3.9 vs. 14.1 ± 2.8) between groups. There was no significant difference in VAS (1.48 ± 2.0 vs. 1.49 ± 2.1, p = 0.972), satisfaction (86.1% ± 24.2% vs. 81.2% ± 27.9, p = 0.311), or revision surgeries (10.2% vs. 10.2%) between groups. CONCLUSION: There was a low complication rate, excellent patient reported outcomes, and a low rate of recurrent patellar instability following TTO and MPFLR with allograft.

Synovial Fluid Biomarker Alternatives Can Plasma and Urine Samples Shed Light on the Post-Traumatic Intra-Articular Microenvironment?

The purpose of this study was to analyze the relationship between the intra-articular inflammatory response and any associated systemic inflammatory response following knee injury requiring operative management. Patients undergoing primary knee arthroscopy provided synovial fluid, blood, and urine samples immediately prior to surgery. Samples were analyzed using a multiplex magnetic bead immunoassay for the concentrations of cytokines and growth factors that have been shown to be associated with post-injury inflammation. One hundred and fifty-one patients undergoing arthroscopic management of meniscus, ACL, and focal chondral lesions were included in the analysis. After correction for multiple tests, there were no statistically significant correlations between synovial fluid biomarkers and biomarkers in plasma or urine for any of the intra-articular pathologies assessed. This analysis suggests that the most accurate measurement of the post-injury inflammatory response must be sampled from the intra-articular space. In the post-traumatic knee, there is no substitute for synovial fluid biomarker analysis.

Levels of Synovial Fluid Inflammatory Biomarkers on Day of Arthroscopic Partial Meniscectomy Predict Long-Term Outcomes and Conversion to TKA: A 10-Year Mean Follow-up Study.

BACKGROUND: The purpose of the present study was to evaluate the relationships of the concentrations of pro- and anti-inflammatory biomarkers in the knee synovial fluid at the time of arthroscopic partial meniscectomy (APM) to long-term patient-reported outcomes (PROs) and conversion to total knee arthroplasty (TKA). METHODS: A database of patients who underwent APM for isolated meniscal injury was analyzed. Synovial fluid had been aspirated from the operatively treated knee prior to the surgical incision, and concentrations of pro- and anti-inflammatory biomarkers (RANTES, IL-6, MCP-1, MIP-1ß, VEGF, TIMP-1, TIMP-2, IL-1RA, MMP-3, and bFGF) were quantified. Prior to surgery and again at the time of final follow-up, patients were asked to complete a survey that included a visual analog scale (VAS) for pain and Lysholm, Tegner, and Knee injury and Osteoarthritis Outcome Score-Physical Function Short Form (KOOS-PS) questionnaires. Clustering analysis of the 10 biomarkers of interest was carried out with the k-means algorithm. RESULTS: Of the 82 patients who met the inclusion criteria for the study, 59 had not undergone subsequent ipsilateral TKA or APM, and 43 (73%) of the 59 completed PRO questionnaires at long-term follow-up. The mean follow-up time was 10.6 ± 1.3 years (range, 8.7 to 12.4 years). Higher concentrations of individual pro-inflammatory biomarkers including MCP-1 (ß = 13.672, p = 0.017) and MIP-1ß (ß = -0.385, p = 0.012) were associated with worse VAS pain and Tegner scores, respectively. K-means clustering analysis separated the cohort of 82 patients into 2 groups, one with exclusively higher levels of pro-inflammatory biomarkers than the second group. The "pro-inflammatory phenotype" cohort had a significantly higher VAS pain score (p = 0.024) and significantly lower Lysholm (p = 0.022), KOOS-PS (p = 0.047), and Tegner (p = 0.009) scores at the time of final follow-up compared with the "anti-inflammatory phenotype" cohort. The rate of conversion to TKA was higher in the pro-inflammatory cohort (29.4% versus 12.2%, p = 0.064). Logistic regression analysis demonstrated that the pro-inflammatory phenotype was significantly correlated with conversion to TKA (odds ratio = 7.220, 95% confidence interval = 1.028 to 50.720, p = 0.047). CONCLUSIONS: The concentrations of synovial fluid biomarkers on the day of APM can be used to cluster patients into pro- and anti-inflammatory cohorts that are predictive of PROs and conversion to TKA at long-term follow-up. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Partial-Thickness Rotator Cuff Tears: Current Concepts.

¼ Partial-thickness rotator cuff tears (PTRCTs) are a common pathology with a likely high asymptomatic incidence rate, particularly in the overhead athlete.¼ The anatomy, 5-layer histology, and relationship to Ellman's classification of PTRCTs have been well studied, with recent interest in radiographic predictors such as the critical shoulder angle and acromial index.¼ Depending on the definition of tear progression, rates of PTRCT progression range from 4% to 44% and appear related to symptomatology and work/activity level.¼ Nearly all PTRCTs should be managed conservatively initially, particularly in overhead athletes, with those that fail nonoperative management undergoing arthroscopic debridement ± acromioplasty if <50% thickness or arthroscopic conversion repair or in situ repair if >50% thickness.¼ Augmentation of PTRCTs is promising, with leukocyte-poor platelet-rich plasma having the most robust body of supportive data. Mesenchymal signaling cell biologics and the variety of scaffold onlay augments require more rigorous studies before regular usage.