Causal relationships between pain, medical treatments, and knee osteoarthritis: A graphical causal model to guide analyses.

OBJECTIVE: Randomized controlled trials (RCTs) are a gold standard for estimating the benefits of clinical interventions, but their decision-making utility can be limited by relatively short follow-up time. Longer-term follow-up of RCT participants is essential to support treatment decisions. However, as time from randomization accrues, loss to follow-up and competing events can introduce biases and require covariate adjustment even for intention-to-treat effects. We describe a process for synthesizing expert knowledge and apply this to long-term follow-up of an RCT of treatments for meniscal tears in patients with knee osteoarthritis (OA). METHODS: We identified 2 post-randomization events likely to impact accurate assessment of pain outcomes beyond 5 years in trial participants: loss to follow-up and total knee replacement (TKR). We conducted literature searches for covariates related to pain and TKR in individuals with knee OA and combined these with expert input. We synthesized the evidence into graphical models. RESULTS: We identified 94 potential covariates potentially related to pain and/or TKR among individuals with knee OA. Of these, 46 were identified in the literature review and 48 by expert panelists. We determined that adjustment for 50 covariates may be required to estimate the long-term effects of knee OA treatments on pain. CONCLUSION: We present a process for combining literature reviews with expert input to synthesize existing knowledge and improve covariate selection. We apply this process to the long-term follow-up of a randomized trial and show that expert input provides additional information not obtainable from literature reviews alone.

Risk factors for false positive and false negative MRI in diagnosing medial and lateral meniscal tears with concomitant ACL injury.

OBJECTIVE: To determine the diagnostic performance of MRI in evaluating meniscal abnormalities in the setting of anterior cruciate ligament (ACL) injury and recognize predictors of false positive (FP) and false negative (FN) MRI diagnosis. MATERIAL AND METHODS: Four hundred twenty patients (mean age, 27.2 years; 326 males, 94 females) who underwent arthroscopy for ACL injury between January 2017 and August 2022, and had preoperative imaging within 4 months, were retrospectively included. Images were independently interpreted by two experienced musculoskeletal radiologists, noting the presence of medial and lateral meniscal tears including tear type and location. Results were correlated with arthroscopic findings. Multivariate logistic regression was implemented to study risk factors (RF) for FP and FN MRI diagnosis. RESULTS: The sensitivity/specificity/positive predictive value/negative predictive value/accuracy of MRI for medial meniscus tear was 97.5%/74.46%/65.63%/98.35%/82.15%; for lateral meniscus tear, it was 83.5%/93.70%/70.8%/94.55% /87.86%, with substantial interreader agreement. Female gender (odds ratio (OR), 0.434), posterior horn and posterior root tears (OR, 3.268/22.588), horizontal tear (OR, 3.134), and ramp lesion (OR, 4.964) were found RF for FP medial meniscus, and meniscal body tears (OR, 308.011) were found RF for FP lateral meniscus. RF for FN medial meniscus were meniscal tear at the posterior horn, body, and posterior root (OR, 12.371/123.000/13.045). CONCLUSION: MRI is an effective screening tool for meniscal tears, but less accurate in detecting all medial meniscus injuries. Gender, meniscal tear location, and type increased the risk of FP medial meniscal tear on MRI, while meniscal tear location increased the risk of FP lateral meniscus and FN medial meniscus tears.

Retrospective evaluation of MRI findings in arthroscopically confirmed cases of hypermobile lateral meniscus.

OBJECTIVE: To identify preoperative MRI findings in patients with arthroscopically confirmed hypermobile lateral meniscus utilizing a standard MRI knee protocol, with comparison to normal control and lateral meniscal tear groups. SUBJECTS AND METHODS: All patients with arthroscopically confirmed hypermobile lateral meniscus diagnosed at our institution were retrospectively identified. The following structures were evaluated on preoperative knee MRIs: superior and inferior popliteomeniscal fascicles, lateral meniscus and meniscocapsular junction, popliteal hiatus, and soft tissue edema around the popliteal hiatus. The same MRI features were evaluated in the normal control and lateral meniscal tear groups. RESULTS: Study, normal control, and lateral meniscal tear patients (18 each) were included. In the study group, 94.4% had superior popliteomeniscal fascicle abnormality, 89.0% had inferior popliteomeniscal fascicle abnormality, and 72.2% had lateral meniscal abnormality. Incidence of these abnormalities was significantly higher than in the normal control group. Meniscal abnormalities in the study group all involved the posterior horn meniscocapsular junction, 12/13 of which had vertical signal abnormality at the junction and 1/13 with anterior subluxation of the entire posterior horn. Popliteus hiatus measurements were largest in the lateral meniscal tear group. CONCLUSION: In patients with hypermobile lateral meniscus, the combination of popliteomeniscal fascicle abnormality and vertical signal abnormality at the meniscocapsular junction was seen in the majority of patients. Popliteomeniscal fascicle signal abnormality without identifiable lateral meniscal injury was the next most common imaging appearance. Radiologists may provide valuable information by suggesting the diagnosis of hypermobile lateral meniscus in such cases.

Treatment of chronic and complex meniscal tears with arthroscopic meniscus repair augmented with collagen matrix wrapping: failure rate and functional outcomes.

PURPOSE: Meniscal wrapping is a fully arthroscopic technique that involves enhanced meniscal repair with a tissue-engineered collagen matrix wrapping. This study aims to investigate the feasibility of using the meniscal wrapping technique for the treatment of chronic or complex meniscal tears. The primary objective is to assess its failure rate. The secondary objectives are to analyse complication rate, functional outcomes and overall patient satisfaction. METHODS: This retrospective case series study included patients who sustained chronic and complex tears undergoing meniscal wrapping with autologous liquid bone marrow injection. Failure rate was considered if the patient underwent partial or complete meniscectomy or knee replacement during the follow-up, while other unexpected knee reoperations were considered as complications. Clinical outcomes were evaluated through the IKDC score, Tegner Activity Score and Short Assessment of Patient Satisfaction. RESULTS: Twenty-one patients were included (15 non-acute bucket-handle tears, three non-acute horizontal tears and three non-acute complex injuries). The failure rate was 9.5% at 33 months. The rate of other unplanned reoperations was 14.3%, but none of these complications were apparently directly related to the wrapping technique. The average postoperative IKDC was 73.3/100. No statistically significant difference was encountered between preinjury and postoperative Tegner Activity Score. The mean overall patient satisfaction was 88.3/100. CONCLUSIONS: Meniscal wrapping can be safely used as an adjunctive technique to meniscal repair in such difficult-to-treat cases to preserve the meniscus. The technique achieves a low failure rate and promising results of knee function, and patient satisfaction.

Influence of a posteromedial meniscocapsular injury on the knee anterior laxity. A cadaveric study.

PURPOSE: The number of anterior cruciate ligament (ACL) injuries has considerably increased in the recent years, especially in young adults and adolescents. Associated meniscal tears increase anterior and rotary laxity. Posterior peripheral meniscocapsular tear of medial meniscus is also called ramp lesion. Prevalence of 9% to 17% in adults and up to 23% in pediatric population has been reported. The aim of this study was to determine anterior laxity of cadaveric ACL-deficient knees with several size of ramp lesions. METHODS: Fresh cadaveric knees were explored. Major osteoarthritis and/or ACL and meniscal tears on arthroscopy were exclusion criteria. Mean age at death was 86 years old. Dynamic laximetry with GNRB® device was made in several conditions: Knee prior to any procedure, after arthroscopic exploration, after ACL section, and then after increasing sizes of ramp lesions up to 30 mm. Anteroposterior laxity was measured with 2 loading forces successively (134N and 200N). RESULTS: After ACL section only, tibiofemoral joint anterior laxity was significantly increased. Mean increase was 156% regardless of the loading force. No statistical laxity difference was found between knees with ACL section only and knees with ACL and meniscal section for any size of ramp lesions. Increasing size of ramp lesion was not correlated with increasing of laxity. CONCLUSION: We could not find a threshold size of ramp lesion which increases knee anterior laxity. We were not able to determine a threshold recommending a ramp lesion repair.

Medial meniscal posterior horn tears and ramp lesions in pediatric patients: lessons learned.

Meniscal injuries are increasingly reported in pediatric patients due to early sports participation and are commonly encountered during anterior cruciate ligament reconstruction. Preoperative identification of meniscal tears is crucial, particularly when involving the posteromedial meniscocapsular junction (ramp lesion). MRI plays an important role in detecting this particular type of meniscal injury. Consequently, pediatric radiologists should be aware of particular MRI findings related to ramp lesions including the presence of a medial meniscal tear, peripheral meniscal irregularity, meniscocapsular junctional fluid-like signal intensity, and capsular ligament tears. Thus, we illustrate the lessons we have learned from our institutional multidisciplinary arthroscopic-MR correlation conference for retrospectively identified posterior horn medial meniscal tears and ramp lesions.

Maturation-dependent patterns of knee injuries among symptomatic pediatric soccer players on MRI.

OBJECTIVE: To systematically investigate the prevalence of knee MRI findings among symptomatic pediatric soccer players with respect to skeletal maturity and to identify predictors of surgery. METHODS: This IRB-approved, HIPAA-compliant retrospective study included soccer players (< 18 years of age) who underwent MRI examinations in the past 5 years (2018-2023). Two radiologists retrospectively and independently reviewed all examinations to categorize skeletal maturity and to identify osseous and soft tissue findings. Findings were compared between maturation groups, and logistic regression models were used to identify predictors of surgery. RESULTS: Ninety-seven players (45 boys, 52 girls) included 39 skeletally immature, 21 maturing, and 37 mature knees. Kappa coefficient for interobserver reliability ranged between 0.65 and 1.00. Osgood-Schlatter disease (OSD) was more common among immature than maturing and mature knees (25% vs 14% and 5%, p = 0.04); anterior cruciate ligament (ACL) injury was more common among maturing and mature than immature knees (59% and 48%, vs 15%, p < 0.01); and meniscal tears were more common among mature than immature and maturing knees (medial, 41% vs 18% and 14%, p = 0.03; lateral, 43% vs 21% and 19%, p = 0.04). Players in the mature group were more likely to undergo surgery (p = 0.01). The presence of an effusion (OR = 19.5, 95% CI 2.8-240.9, p = 0.01), ACL injury (OR = 170.0, 95% CI 1.3-6996.9, p < 0.01), and lateral meniscal tears (OR = 10.8, 95% CI 1.8-106.1, p = 0.02) were independent predictors of surgery. CONCLUSION: Differential patterns of injury were found among symptomatic pediatric soccer players; the presence of an effusion, ACL injury, and lateral meniscal tears were independent predictors of surgery, likely contributing to the higher rates of surgery among skeletally mature players.

Internal tibial torsion is associated with medial meniscus posterior horn tears.

PURPOSE: Risk factors for meniscal tears play a decisive role in deciding on treatment and rehabilitation. The purpose of this study was to investigate the effect of tibial rotation on medial meniscus posterior horn tears (MMPHTs). METHODS: This study is a retrospective case-control study. Fifty patients with meniscal tears and 57 knees with intact meniscus were compared. Tibial rotation, femoral version, tibial slope and knee varus were measured in each participant. Knee osteoarthritis was classified according to the Kellgren-Lawrence classification. Demographic characteristics were noted. RESULTS: There were significant differences in the mean tibial torsion angles and mean mechanical axes between the groups. The mean tibial rotation and mean mechanical axis were 26.3° ± 6.7 and 3.7° ± 2.7 in the MMPHT group and 30.3° ± 8.4 and 2.05° ± 2.7 in the control group, respectively (p = 0.008, p = 0.002). CONCLUSION: The current retrospective study has shown that tibial rotation is markedly reduced in patients with MMPHTs. Although the actual mechanism is not clear, the internal torsion of the tibia causes a decrease in the foot progression angle and increases the knee adduction moment, which in turn increases the medial tibial contact pressure. Internal torsion of the tibia, such as knee varus, may play a role in the aetiology of MMPHTs by this way. Whilst there was a significant difference in the mean varus and tibial torsion between the groups, there was no significant difference in the mean femoral version or tibial slope. LEVEL OF EVIDENCE: III.

Delaying ACL reconstruction is associated with increased rates of medial meniscal tear.

PURPOSE: The aim of this study was to evaluate the relationship between the time from injury to ACL reconstruction (ACLR) and the rate as well as repairability of meniscal tears. Secondary aims were to evaluate the relationship between meniscal injury and Tegner Activity Scale, age, BMI, and gender. METHODS: Between 2012 and 2022, 1,840 consecutive ACLRs were performed. A total of 1,317 ACLRs were included with a mean patient age of 31.2 years ± 10.5 [16-60]. Meniscal tear was assessed during arthroscopy using the ISAKOS classification. Time from injury to ACLR, Tegner Activity Scale, age, BMI and gender were analysed in uni- and then in multivariate analyses. Patients were divided into four groups according to the time from injury to surgery: < 3 months (427; 32%), 3-6 months (388; 29%), 6-12 months (248; 19%) and > 12 months (254; 19%). RESULTS: Delaying ACLR > 12 months significantly increased the rate of medial meniscal (MM) injury (OR 1.14; p < 0.001). No correlation was found between a 3- or 6-month time from injury to surgery and MM tear. Performing ACLR > 3, 6, or 12 months after injury did not significantly increase the rate of lateral meniscal (LM) injury. Increasing Tegner activity scale was significantly associated with a lower rate of MM injury (OR 0.90; p = 0.020). An age > 30 years (OR 1.07; p = 0.025) and male gender (OR 1.13; p < 0.0001) was also associated with an increased rate of MM injury. Age > 30 years decreased the rate of MM repair (OR 0.85; p < 0.001). Male gender increased the rate of LM tear (OR 1.10; p = 0.001). CONCLUSION: Performing ACLR more than 12 months after injury was associated with increased rates of MM injury but not with lower rates of repairable lesions. An increased pre-injury Tegner activity score was associated with a decreased rate of MM tear. Age > 30 years was associated with an increased rate of MM tear with concomitant ACL injury and a decreased rate of repairability of MM tear. ACLR should be performed within 12 months from injury to prevent from the risk of MM injury. LEVEL OF EVIDENCE: Level III.

Subchondral bone remodeling patterns in larger animal models of meniscal injuries inducing knee osteoarthritis - a systematic review.

PURPOSE: Elucidating subchondral bone remodeling in preclinical models of traumatic meniscus injury may address clinically relevant questions about determinants of knee osteoarthritis (OA). METHODS: Studies on subchondral bone remodeling in larger animal models applying meniscal injuries as standardizing entity were systematically analyzed. Of the identified 5367 papers reporting total or partial meniscectomy, meniscal transection or destabilization, 0.4% (in guinea pigs, rabbits, dogs, minipigs, sheep) remained eligible. RESULTS: Only early or mid-term time points were available. Larger joint sizes allow reporting higher topographical details. The most frequently reported parameters were BV/TV (61%), BMD (41%), osteophytes (41%) and subchondral bone plate thickness (39%). Subchondral bone plate microstructure is not comprehensively, subarticular spongiosa microstructure is well characterized. The subarticular spongiosa is altered shortly before the subchondral bone plate. These early changes involve degradation of subarticular trabecular elements, reduction of their number, loss of bone volume and reduced mineralization. Soon thereafter, the previously normal subchondral bone plate becomes thicker. Its porosity first increases, then decreases. CONCLUSION: The specific human topographical pattern of a thinner subchondral bone plate in the region below both menisci is present solely in the larger species (partly in rabbits), but absent in rodents, an important fact to consider when designing animal studies examining subchondral consequences of meniscus damage. Large animal models are capable of providing high topographical detail, suggesting that they may represent suitable study systems reflecting the clinical complexities. For advanced OA, significant gaps of knowledge exist. Future investigations assessing the subchondral bone in a standardized fashion are warranted.

Incidence and type of meniscal tears in multilligament injured knees.

PURPOSE: Meniscal injuries occurring during multi-ligament knee injuries (MLKI) are underreported. The purpose of this study was to compare the incidence and type of meniscal tears seen at the time of multi-ligament reconstruction surgery compared to those occurring during isolated anterior cruciate ligament (ACL) surgery. METHODS: Patients undergoing surgical treatment for MLKI and ACL-only injuries between 2010 and 2020 were reviewed. Two-hundred and thirty-five patients were included in the MLKI group. There were 131 chronic injuries and 104 acute injuries. Two-hundred and twenty-two ACL-only chronic injuries were used as a control group for comparison with the chronic MLKI group. Demographic data, type of meniscal tears, ligament injury patterns (Schenck classification) and time from injury to surgery were recorded. A delayed procedure was defined by a 4-week interval after the knee injury. RESULTS: A meniscus was torn in 69 knees (29.4%): 36 knees (15.3%) with an isolated medial meniscus tear, 33 knees (17.9%) with an isolated lateral meniscus tear,.Nine knees (3.8%) had both menisci torn. MLKI with medial or lateral-sided bicruciate ligament injuries (KDIIIM-KDIIIL) were significantly associated with a lower rate of meniscal tears than knee injuries involving the ACL-only and medial/lateral-sided ligament injuries (KDI) (medial-sided injuries p = 0.025; lateral-sided injuries p = 0.049). Lateral-sided injuries had significantly less meniscal damage than medial-sided injuries: 22/124 (17.7%) vs. 41/100 (41%); (p < 0.001). No significant differences were found for frequency, type and distribution of meniscal tears between acute and chronic MLKI surgery. ACL-only chronic injuries were associated with a higher rate of meniscal tears: 123/222 knees (55.4%) vs. 35/131 (26.9%) chronic MLKI; (p < 0.001), mainly involving the medial meniscus: 102/222 (46%) vs. 18/131 (13.7%); (p < 0.001). CONCLUSIONS: Meniscal tears were less common in the MLKI group than in the isolated ACL injury group. The degree of ligament injury patterns and the side of the injured collateral ligament influenced the type and incidence of meniscal damage. Contrary to isolated ACL injuries, a delayed procedure was not associated with a higher rate of meniscal lesions but did influence the type of treatment. Understanding of meniscal tears patterns in MLKI helps to improve the treatment management of these complex injuries.

Lateral meniscus with tears or with histologic calcification does not increase the risk of lateral osteoarthritis after medial unicompartmental arthroplasty.

PURPOSE: Meniscal tears or histological meniscal calcifications (in the absence of radiological chondrocalcinosis) are frequent in osteoarthritis. Whether lateral meniscal lesions influence clinical outcomes after medial unicompartmental knee arthroplasty (UKA) is unknown. METHODS: We analyzed 130 patients (130 knees) with medial unicompartmental knee arthroplasties between 2005 and 2015. These 130 knees had full articular cartilage thickness in the lateral compartment and no radiological chondrocalcinosis on preoperative radiographs. The lateral meniscus was analyzed with preoperative MRI and a biopsy of the anterior horn at the time of surgery. Synovial fluid was collected and analyzed for calcium pyrophosphate dihydrate crystal deposition (CPPD crystals). Lateral meniscal tears were untreated when detected on MRI or during surgery, with the hypothesis that these tears on the opposite compartment would remain asymptomatic in medial UKA. At average 10-year follow-up, patients were evaluated with clinical and radiographic outcome, with a focus on the risk of joint space narrowing of the lateral femorotibial compartment. RESULTS: CPPD crystals were present in the synovial fluid of 70 knees. Lateral meniscal tears were seen on MRI in 34 (49%) normal meniscuses of the 60 knees without CPPD crystals and in six other knees without histological meniscal calcification despite CPPD crystals. Histological calcification was present on 61 lateral meniscuses with 53 meniscal tears. The results showed no significant differences in the clinical outcomes between knees with lateral meniscal tears or lateral meniscal histological chondrocalcinosis or both lesions and those without these conditions. Additionally, radiographic progression of osteoarthritis in the opposite femorotibial compartment of the knee was not more frequent in patients with these meniscal issues. The ten year cumulative survival rates, measured by the need for total knee arthroplasty, were 91% for knees without meniscal lesions and 92% for knees with these lesions. CONCLUSION: On this basis, treatment of meniscal tears of the lateral compartment and routine aspiration of the knee to assess for birefringent crystals in the planning of medial UKA do not appear necessary.

Incomplete meniscal healing in early second-look arthroscopy does not indicate failure of repair: a case series.

PURPOSE: To assess if incomplete meniscal healing during second-look arthroscopy at six to eight weeks after all-inside suture hook meniscus repair results in longer-term failure of repair in patients with restored knee stability. METHODS: From 2008 to 2013, 41 patients with post-traumatic, longitudinal, vertical, complete meniscal tears with concomitant ACL injury were treated via a two-stage surgical procedure and prospectively evaluated. In the first stage, all-inside meniscus repair was performed using suture hook passers and non-absorbable sutures. In total, there were 26 medial and 16 lateral meniscus tears. A second-stage ACL reconstruction, performed six to eight weeks later, served as an early second-look arthroscopic evaluation of meniscal healing. Clinical follow-up was performed at a minimum of 24 months. RESULTS: Second-look arthroscopy revealed 31 cases (75.6%) of complete and ten cases (24.4%) of incomplete meniscal healing. Two patients were lost prior to follow-up, and three were excluded due to recurrent instability. Therefore, 36 patients were assessed at the final follow-up. All patients with complete meniscal healing during second-look arthroscopy achieved clinical success at follow-up. Six out of nine (66.7%) of patients with incomplete meniscal healing during second-look arthroscopy achieved clinical success at follow-up (p = 0.012). One saphenous neuropathy occurred (2.4%). CONCLUSION: Incomplete meniscal healing during early second-look arthroscopy after all-inside meniscal repair using suture hook passers and non-absorbable sutures did not necessarily result in longer-term failure in patients with restored knee stability. The described method of meniscal repair was associated with a low rate of symptomatic re-tears and complications.

Long-term clinical results of using a posteromedial all-inside and anteromedial inside-out approach to repair unstable or irreducible bucket-handle medial meniscal tears.

BACKGROUND: In irreducible bucket-handle medial meniscal tears (BHMMTs), the displaced central fragment is rotated 180° or more, meaning reduction is impossible without derotation of the tear. In chronic cases, the rotated meniscus is deformed and degenerated; thus, the issue of reproducibility and repairability arises. This study presents the clinical outcomes of chronic irreducible and unstable locked BHMMTs. Radiological outcomes were also evaluated using magnetic resonance imaging (MRI). METHODS: This is a retrospective study of 37 patients with 11 cases of irreducible BHMMT and 26 cases of reducible but unstable chronic BHMMT who underwent operations between 2011 and 2016. Posterior arthroscopy was performed after temporary meniscus fixation using a provisional needle fixation technique. After the posterior repair with vertical mattress sutures was completed using an all-inside technique, the classic outside-in technique was performed for the anterior third of the meniscus. The Lysholm, International Knee Documentation Committee (IKDC), and Tegner activity scores were obtained from all patients before surgery and at the latest follow-up. Radiological evaluations were performed using MRI before surgery and at 6 months postoperatively. RESULTS: Between 2011 and 2016, a total of 37 consecutive patients with irreducible and chronic BHMMTs underwent surgery. The average postoperative follow-up was 7.2 ± 1.4 years (mean ± SD). Postoperative Lysholm (89.57 ± 2.7) and IKDC (87.22 ± 3.2) scores improved significantly at the last follow-up when compared with the pre-operative scores (38.44 ± 4.5 and 23.52 ± 7.8, respectively). According to the Tegner activity scale, patients' postoperative activity levels remained unchanged compared to preoperative levels at the last follow-up. CONCLUSION: Posterior knee arthroscopy with the all-inside posterior suture and inside-out anteromedial suture technique presented in this study yielded excellent clinical outcomes when used to repair chronic irreducible or unstable BHMMTs. LEVEL OF EVIDENCE: Level IV.

Mechanical symptoms and meniscal tear: a reappraisal.

OBJECTIVE: To identify and summarize literature related to the association between mechanical symptoms (catching and locking of the knee), the presence of meniscal tear, and outcomes after arthroscopic surgery. DESIGN: We searched PubMed and hand-searched reference lists for relevant articles and selected 38 for analysis. RESULTS: Mechanical symptoms appear to have modest sensitivity (ranging 0.32-0.69), specificity (ranging 0.45-0.74) and positive predictive value (ranging 0.75-0.81) for meniscal tear. There is also very little evidence to suggest that those with mechanical symptoms experience better outcomes after arthroscopic surgery. CONCLUSION: Our examination of the literature does not support the hypothesis that mechanical symptoms are related to the presence of meniscal tear or portend better outcomes after arthroscopic surgery.

Evidence-based rationale for treatment of meniscal lesions in athletes.

Meniscal injuries in elite athletes are a common cause of missed game time and even have the potential to be career shortening. In this patient group, care must be paid not only to the pathology, but also to a player's contract status, time in the season, specific demands of his/her sport and position on the field, and future consequences. Successful treatment requires the clinician to understand the player's goals and needs, communicate effectively between all stakeholders, and a have knowledge of the challenges posed by the different types of meniscal tear seen in this population. Paramount is the distinction between injuries to the medial and lateral meniscus. Deficiency of the lateral meniscus, as a result of a tear or a meniscectomy, leads to frequent early problems and inexorably to chondral degeneration thereby affecting an athlete's ability to perform. Therefore, it is strongly recommended to repair the majority of lateral meniscal tears. Medial meniscal tears pose a more challenging treatment dilemma, as the success of partial meniscectomy in achieving reproducible, early return to play must be balanced against the long-term degenerative consequences. Many meniscal tears are correctly treated non-operatively.Level of evidence V.

Meniscal Tear and ACL Injury Detection Model Based on AlexNet and Iterative ReliefF.

Magnetic resonance (MR) is one of the special imaging techniques used to diagnose orthopedics and traumatology. In this study, a new method has been proposed to detect highly accurate automatic meniscal tear and anterior cruciate ligament (ACL) injuries. In this study, images in three different slices were collected. These are the sagittal, coronal, and axial slices, respectively. Images taken from each slice were categorized in 3 different ways: sagittal database (sDB), coronal database (cDB), and axial database (aDB). The proposed model in the study uses deep feature extraction. In this context, deep features have been obtained by using fully-connected layers of AlexNet architecture. In the second stage of the study, the most significant features were selected using the iterative RelifF (IRF) algorithm. In the last step of the application, the features are classified by using the k-nearest neighbor (kNN) method. Three datasets were used in the study. These datasets, sDB, and cDB, have four classes and consist of 442 and 457 images, respectively. The aDB used in the study has two class labels and consists of 190 images. The model proposed within the scope of the study was applied in 3 datasets. In this context, 98.42%, 100%, and 100% accuracy values were obtained for sDB, cDB, and aDB datasets, respectively. The study results showed that the proposed method detected meniscal tear and anterior cruciate ligament (ACL) injuries with high accuracy.

The impact of body mass index on the accuracy of the physical examination of the knee.

PURPOSE: Obesity is a worldwide pandemic; however, no adaptations were made to the physical examination of obese patient's knees. The accuracy of the physical examination is critical for correct assessment and selection of treatment. We aimed to assess whether body mass index (BMI) affects the sensitivity and specificity of common provocative knee tests. METHODS: We studied 210 patients who underwent knee arthroscopy to treat anterior cruciate ligament (ACL) and meniscal pathologies. BMI and the knee's physical examination were documented pre-operatively. Sensitivity, specificity, and accuracy of ACL and meniscal provocative tests in relation to BMI were evaluated using arthroscopy as a gold standard. RESULTS: The Anterior Drawer, Lachman, and Pivot-Shift tests for ACL tears were significantly less accurate and sensitive, yet more specific, in obese patients when compared to normal and overweight patients. The McMurray, Apley Grind, and Thessaly tests for medial meniscus tears showed greater sensitivity, but lower specificity, in patients with increased BMI. Above normal BMIs, independently of age and gender, were significantly associated with higher odds for positive ACL tests. CONCLUSION: Tests for ACL tears are less sensitive in obese patients and alternatives to the classic tests should be considered. Medial meniscus tests tend to be more sensitive and less specific in patients with greater BMIs. Their results should be carefully interpreted due to possible false positives. The physician should take into consideration the impact of patient BMI on the accuracy of their physical examination of the knee to optimize treatment decision-making.

Bucket handle meniscus tears in low-resource settings can be successfully treated with a cost-effective technique.

PURPOSE: In regions of the world where resources can limit medical care (limited-resource settings, LRS), most meniscal tears are often treated with meniscectomy. A simple, low-cost option for meniscal repair has been developed. We sought to evaluate patient reported outcomes (PROMs) and clinical failure rates of bucket handle meniscus tears (BHTs) treated with meniscal repair in a LRS. METHODS: We prospectively enrolled patients over 18 who were treated for BHT with meniscal repair in a LRS. Meniscal repair was primarily accomplished using an outside-in technique. Pre-injury and final follow-up PROMs were recorded. Clinical failure was defined as the need for re-operation or symptoms that prevented the patient from returning to recreational activities or work responsibilities. RESULTS: Nineteen patients with a mean age of 25.4 years were eligible. Two patients sustained a clinical failure (10.5%). At mean follow-up of 40.6 months, there was significant improvement in all PROMs from baseline. Subgroup analysis revealed no significant difference in the failure group compared to the success group in number of knots used, pre-injury Tegner score, number of devices used, suture type, or technique. CONCLUSION: Bucket-handle meniscal tears can be repaired using a low-cost technique resulting in satisfactory healing rates and excellent outcomes.

Are structural abnormalities on knee MRI associated with osteophyte development? Data from the Osteoarthritis Initiative.

OBJECTIVE: To assess which structural abnormalities on knee MRI are associated with development of osteophytes in middle-aged subjects without radiographic knee osteoarthritis. DESIGN: We included subjects from the Osteoarthritis Initiative, aged 40-55 years, Kellgren & Lawrence grade 0 in both knees, and knee MRIs from both knees available at baseline, 24, 48 and 72 months. Structural exposures on MRI assessed using MOAKS included cartilage damage, bone marrow lesions, meniscal tear, meniscal extrusion, and Hoffa/effusion synovitis. We assessed whether each structural exposure was associated with the development of osteophytes on MRI in the medial and lateral tibiofemoral, and patellofemoral compartment. We estimated hazard ratios (HR) including 95% confidence intervals (CI) for osteophyte development using a mixed complementary log-log regression model adjusted for age, sex, and body mass index. RESULTS: We included 680 knees from 340 subjects with a mean (SD) age of 50 years (3.0), and 51% men. In the medial tibiofemoral compartment, the absolute risk of osteophyte development in the first 24-month period was 4% in knees without, and 15% in knees with medial meniscal tear. Corresponding adjusted HR was 6.6 (95%CI = 3.4-12.9). In the lateral tibiofemoral compartment, the adjusted HR for developing osteophytes having a lateral meniscal tear was 3.3 (95%CI = 1.3-8.4). In the patellofemoral compartment, patellofemoral cartilage damage was most clearly associated with developing osteophytes (HR = 2.6, 95%CI = 1.8-3.7). CONCLUSIONS: Meniscal tear seem to be the strongest structural risk factor for the development of tibiofemoral osteophytes, and patellofemoral cartilage damage for the development of patellofemoral osteophytes, respectively. Local biomechanical factors are important in early osteophyte development.