Associations among meniscal damage, meniscal symptoms and knee pain severity

Utility of MRI for Patients 45 Years Old and Older With Hip or Knee Pain: A Systematic Review

BACKGROUND. MRI utility for patients 45 years old and older with hip or knee pain is not well established. OBJECTIVE. We performed this systematic review to assess whether MRI-diagnosed hip or knee pathology in patients 45 years old and older correlates with symptoms or benefits from arthroscopic surgery. EVIDENCE ACQUISITION. A literature search (PubMed, Web of Science, Embase) of articles published before October 3, 2022, was performed to identify original research pertaining to the study question. Publication information, study design, cohort size, osteoarthritis severity, age (range, mean), measured outcomes, minimum follow-up length, and MRI field strength were extracted. Study methods were appraised with NIH's study quality assessment tools. EVIDENCE SYNTHESIS. The search yielded 1125 potential studies, of which 31 met the inclusion criteria (18 knee, 13 hip). Knee studies (10 prospective, eight retrospective) included 5907 patients (age range, 45-90 years). Bone marrow edema-like lesions, joint effusions, and synovitis on MRI were associated with symptoms. In patients with osteoarthritis, meniscal tears were less likely to be symptom generators and were less likely to respond to arthroscopic surgery with osteoarthritis progression. Hip studies (11 retrospective, two prospective) included 6385 patients (age range, 50 to ≥ 85 years). Patients with Tönnis grade 2 osteoarthritis and lower with and without femoroacetabular impingement (FAI) showed improved outcomes after arthroscopy, suggesting a role for MRI in the diagnosis of labral tears, chondral lesions, and FAI. Although this group benefited from arthroscopic surgery, outcomes were inferior to those in younger patients. Variability in study characteristics, follow-up, and outcome measures precluded a meta-analysis. CONCLUSION. In patients 45 years old and older, several knee structural lesions on MRI correlated with symptoms, representing potential imaging biomarkers. Meniscal tear identification on MRI likely has diminished clinical value as osteoarthritis progresses. For the hip, MRI can play a role in the diagnosis of labral tears, chondral lesions, and FAI in patients without advanced osteoarthritis. CLINICAL IMPACT. Several structural lesions on knee MRI correlating with symptoms may represent imaging biomarkers used as treatment targets. Osteoarthritis, not age, may play the greatest role in determining the utility of MRI for patients 45 years old and older with hip or knee pain.

Medial Meniscal Extrusion in Patients With Medial Meniscus Root Tears: A Systematic Review and Meta-analysis

Background

Medial meniscal extrusion (MME) has received significant interest because of its correlation with medial meniscus root tears (MMRTs), its potential as a diagnostic tool, and its significance in the progression of knee osteoarthritis (OA).

Purpose

To (1) evaluate if MMRTs significantly increase MME compared with nonroot tears (NRTs) and no tears and (2) determine the clinical outcomes of increased MME.

Study Design

Systematic review; Level of evidence, 4.

Methods

Electronic database searches of PubMed, Embase, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials were conducted on June 6, 2022, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 checklist criteria. The searches were conducted using the keywords "meniscus tear" and "extrusion." No restrictions were placed on the date of publication. Quality and sensitivity assessments were conducted on included studies. Major MME was defined as an extrusion ≥3 mm.

Results

Twenty-two studies involving 7882 knees were included. Compared with patients with NRTs, those with MMRTs had a 1.12-mm greater mean absolute meniscal extrusion (AME) and were 3.45 times more likely to have major MME (P < .001 for both). Compared with patients with no tears, those with MMRTs had a 2.13-mm greater AME (P < .001). Within patients with MMRT, those with widely displaced MMRT had a 1.01-mm greater AME compared with nondisplaced MMRT (P < .001). Patients with OA had a 0.73-mm greater AME and were 3.86 times more likely to have major MME compared with patients without OA (P < .001 for both). Within patients who were not stratified according to MMRT, NRT, or no tears, those who eventually developed OA had a 0.79-mm greater AME than those who did not have OA (P = .02).

Conclusion

Patients with MMRTs had higher MME values compared with those with other types of meniscal tears and those without any meniscal tears. Patients with knee OA were more likely to have higher MME compared with those without OA.

Histological Findings and T2 Relaxation Time in Canine Menisci of Elderly Dogs—An Ex Vivo Study in Stifle Joints

Osteoarthritis is a chronic disease that often affects the canine stifle joint. Due to their biomechanical function, the menisci in the canine stifle play an important role in osteoarthritis. They compensate for the incongruence in the joint and distribute and minimize compressive loads, protecting the hyaline articular cartilage from damage. Meniscal degeneration favors the development and progression of stifle joint osteoarthritis. Qualitative magnetic resonance imaging (MRI) is the current golden standard for detecting meniscal changes, but it has limitations in detecting early signs of meniscal degeneration. A quantitative MRI offers new options for detecting early structural changes. T2 mapping can especially visualize structural changes such as altered collagen structures and water content, as well as deviations in proteoglycan content. This study evaluated T2 mapping and performed a histological scoring of menisci in elderly dogs that had no or only low radiographic osteoarthritis grades. A total of 16 stifles from 8 older dogs of different sex and breed underwent ex vivo magnet resonance imaging, including a T2 mapping pulse sequence with multiple echoes. A histological analysis of corresponding menisci was performed using a modified scoring system. The mean T2 relaxation time was 18.2 ms and the mean histological score was 4.25. Descriptive statistics did not reveal a correlation between T2 relaxation time and histological score. Ex vivo T2 mapping of canine menisci did not demonstrate histological changes, suggesting that early meniscal degeneration can be present in the absence of radiological signs of osteoarthritis, including no significant changes in T2 relaxation time.

Grinding, Clicking, and Pivot Pain Resolve in Most Patients After Knee Arthroscopy

PURPOSE

To determine whether knee arthroscopy alleviates the symptom constellation of knee grinding/clicking, catching/locking, and pivot pain.

METHODS

One-year follow-up data from 584 consecutive subjects who underwent knee arthroscopy from August 2012 to December 2019 were collected prospectively. Subjects reported frequency of knee grinding/clicking, catching/locking, and/or pivot pain preoperatively and 1 and 2 years postoperatively. A single surgeon performed each procedure and documented all intraoperative pathology. We measured the postoperative resolution or persistence of these symptoms and used multivariable regression models to identify preoperative demographic and clinical variables that predicted symptom persistence. We also assessed changes in the Pain, Activities of Daily Living, and Quality of Life subscales of the Knee Injury and Osteoarthritis Outcome Score (KOOS).

RESULTS

Postoperative symptom resolution was more likely for grinding/clicking (65.6%) and pivot pain (67.8%) than for catching/locking (44.1%). Smoking status, overweight/obesity, absence of meniscal tear, and number of compartments with focal cartilage lesions predicted persistence of 1 or more patient-reported knee symptoms. KOOS subscale scores consistently improved by at least one standard deviation. Individuals who had resolution of patient-reported knee symptoms exhibited roughly 2-fold improvements in KOOS Pain, ADL and Quality of Life scores compared with those whose symptoms persisted. Persistence of pivot pain was associated with the least improvement of the 3 KOOS subscales.

CONCLUSIONS

Two in three patients with grinding/clicking or pivot pain experience symptom resolution after knee arthroscopy, although catching/locking is more likely to persist. Smoking status, overweight/obesity, absence of meniscal tear, and number of compartments with focal cartilage lesions predict symptom persistence after knee arthroscopy.

LEVEL OF EVIDENCE

Therapeutic Level IV, retrospective cohort analysis of prospective data.

Adjunctive platelet-rich plasma and hyaluronic acid injection after arthroscopic debridement in Kellgren-Lawrence grade 3 and 4 knee osteoarthritis

BACKGROUND

Osteoarthritis (OA) is the most common cause of pain and disability, predominantly affecting the knee. The current management of knee OA falls short of completely stopping disease progression, particularly in Kellgren-Lawrence (KL) grade 3 and 4 knee OA. As such, joint replacement is often recommended, although only 15%-33% of candidates accept it. Alternative therapeutic options are still needed to prevent the progression of joint damage and delay the need for knee arthroplasty.

AIM

To investigate the effect of adjunctive platelet rich plasma (PRP) and hyaluronic acid (HA) after arthroscopic debridement in KL grade 3 and 4 knee OA.

METHODS

This retrospective cohort study used the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score and WOMAC sub-scores (pain, stiffness, and function) to assess 21 patients, grouped according to medical record data of treatment received: Arthroscopic debridement (n = 7); arthroscopic debridement with PRP (n = 7); or arthroscopic debridement with HA (n = 7). WOMAC scores and sub-scores at baseline and at 3 mo and 5 mo posttreatment were recorded. The three-group data were statistically analyzed using the tests of paired t, one-way analysis of variance, and post hoc least significant difference.

RESULTS

All three treatment groups showed significant improvements in WOMAC score and sub-scores from before treatment to 3 mo and 5 mo after treatment. However, the arthroscopic debridement with PRP treatment group, in particular, showed a significantly lower WOMAC pain score than the group who received arthroscopic debridement alone at 5 mo after the procedure (P = 0.03).

CONCLUSION

Compared to arthroscopic debridement alone, adjunctive PRP after arthroscopic debridement significantly lessened the patients’ pain symptom.

Current Controversies in Arthroscopic Partial Meniscectomy

PURPOSE OF REVIEW

Given the continued controversy among orthopedic surgeons regarding the indications and benefits of arthroscopic partial meniscectomy (APM), this review summarizes the current literature, indications, and outcomes of partial meniscectomy to treat symptomatic meniscal tears.

RECENT FINDINGS

In patients with symptomatic meniscal tears, the location and tear pattern play a vital role in clinical management. Tears in the central white-white zone are less amenable to repair due to poor vascularity. Patients may be indicated for APM or non-surgical intervention depending on the tear pattern and symptoms. Non-surgical management for meniscal pathology includes non-steroidal anti-inflammatory drugs (NSAIDs), physical therapy (PT), and intraarticular injections to reduce inflammation and relieve symptoms. There have been several landmark multicenter randomized controlled trials (RCTs) studying the outcomes of APM compared to PT or sham surgery in symptomatic degenerative meniscal tears. These most notably include the 2013 Meniscal Tear in Osteoarthritis Research (MeTeOR) Trial, the 2018 ESCAPE trial, and the sham surgery-controlled Finnish Degenerative Meniscal Lesion Study (FIDELITY), which failed to identify substantial benefits of APM over nonoperative treatment or even placebo surgery. Despite an abundance of literature exploring outcomes of APM for degenerative meniscus tears, there is little consensus among surgeons about the drivers of good outcomes following APM. It is often difficult to determine if the presenting symptoms are secondary to the meniscus pathology or the degenerative disease in patients with concomitant OA. A central tenet of managing meniscal pathology is to preserve tissue whenever possible. Most RCTs show that exercise therapy may be non-inferior to APM in degenerative tears if repair is not possible. Given this evidence, patients who fail nonoperative treatment should be counseled regarding the risks of APM before proceeding to surgical management.

A literature review on plant-based foods and dietary quality in knee osteoarthritis

This literature review summarizes the role of plant-based foods and diet quality in osteoarthritis, particularly knee osteoarthritis, in observational studies and clinical trials published during 2015- 2020. The included studies have suggested favorable results on reducing the prevalence, pain, and cartilage changes related to osteoarthritis and inflammatory and oxidation markers such as inter- leukin-1, interleukin-6, tumor necrosis factor, and lipid peroxidation. Due to the lack of large lon- gitudinal cohorts to study whole foods or diets concerning knee osteoarthritis, findings from the cross-sectional studies or clinical trials require further validation, particularly in well-designed clinical trials and a more extended follow-up period. Potential mechanisms on the role of plant-based foods in body weight, inflammation, and microbiome were explored to explain their protective associations with osteoarthritis. However, most evidence examining the relationship between the microbiome and osteoarthritis joint pain is conducted in preclinical animal studies, and few observational studies show a positive association between Streptococcus species and local joint inflammation in the knee. Given the close links of plant-based foods on obesity, inflammation, and microbiome, data on the role of whole foods or diets in the change in knee osteoarthritis pain through the lens of microbial composition can provide more certainty regarding the utilization of microbiome as a potential thera- peutic target.

Radial T2* mapping reveals early meniscal abnormalities in patients with knee osteoarthritis

OBJECTIVE

We aimed to validate a 2D radial T2* mapping method and its ability to reveal subtle alterations in the menisci of patients with knee osteoarthritis (OA).

METHODS

Of 40 enrolled participants, 20 were diagnosed with OA, and 20 were age- and sex-matched asymptomatic controls. Data from the right knee of each participant were collected using a 1.5-T MRI equipped with a single-channel knee coil. T2* values were acquired using a conventional T2* mapping protocol and a radial T2* mapping method. Mean T2* values in the meniscal white zones, meniscal red zones, and total menisci were calculated. Numerical simulation was performed for validation.

RESULTS

Both simulation and clinical data confirmed that 2D radial T2* mapping provided better discrimination than the conventional method. Compared to controls, the OA group showed significantly greater mean (standard deviation) T2* values in the white zones (9.33 [2.29] ms vs. 6.04 [1.05] ms), red zones (9.18 [2.03] ms vs. 6.81 [1.28] ms), and total menisci (9.26 [2.06] ms vs. 6.34 [1.14] ms). Correlations were found between the Lequesne index and the meniscal T2* values in all three regions (r = 0.528, p = 0.017; r = 0.635, p = 0.003; and r = 0.556, p = 0.011, respectively).

CONCLUSION

These findings indicate that in early OA, radial T2* mapping is an alternative means of assessing meniscal degeneration and can be used to monitor its progression.

KEY POINTS

• Radial T2* mapping outperforms Cartesian T2* mapping. • Radial T2* measurements are useful in assessing meniscal degeneration. • Meniscal T2* values correlate well with disease severity.

Five-Year Structural Changes in Patients with Meniscal Tear and Osteoarthritis: Data from an RCT of Arthroscopic Partial Meniscectomy vs. Physical Therapy

OBJECTIVE

Data from long-term follow-up of several randomized controlled trials (RCTs) of arthroscopic partial meniscectomy (APM) vs. non-operative therapy or sham have suggested that APM may be associated with increased risk of worsening in radiographic features of osteoarthritis (OA). Our objective was to estimate the risk of MRI-based OA structural changes using baseline, 18-month, and 60-month MRI data from an RCT of APM vs. physical therapy in participants with meniscal tear and OA.

METHODS

We used data from the MeTeOR (Meniscal Tear in Osteoarthritis Research) Trial. MRIs were read using the MRI OA Knee Score (MOAKS). We used linear mixed effects models to examine the association between treatment group and continuous MOAKS summary scores, and Poisson regression to assess categorical change in joint structure. Analyses assessed change from baseline to 18 months and 18-to-60 months. We performed both intention-to-treat and as-treated analyses.

RESULTS

The analytic sample included 302 participants. For both treatment groups, more change was seen over the earlier (baseline - 18 months) interval than the later interval. APM was associated with increased risk of any worsening in cartilage surface area damage score (relative risk 1.35, 95% CI 1.14-1.61), osteophytes, and effusion-synovitis over the earlier time period. Only change in osteophytes was significantly different between treatment groups in the later time period.

CONCLUSION

These findings suggest the association between APM and MRI-based changes is most apparent in the 18 months after surgery. The reason for the attenuation of this association over longer follow-up merits further investigation.

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.

Isolated Arthroscopic Partial Meniscectomy Is More Effective at Improving Meniscal Symptoms in Comparison With Mechanical Symptoms in Patients With Concomitant Untreated Chondral Lesions

PURPOSE

To rank Knee Injury and Osteoarthritis Outcome Score (KOOS) questions from most to least improvement after arthroscopic partial meniscectomy (APM) and compare improvement of meniscal versus mechanical symptoms.

METHODS

A secondary analysis of the Chondral Lesions and Meniscus Procedures (ChAMP) Trial was performed. Inclusion criteria were age 30 years or older with degenerative meniscal tear failing nonoperative management, with or without associated unstable chondral lesions. No chondral debridement was performed. Responses to the 42 KOOS questions ranged from 0 (extreme problems) to 4 (no problems), and were answered preoperatively and at 1 year after isolated APM. The 1-year mean change, or delta (Δ), was calculated for each KOOS question and the Δ for meniscal and mechanical symptoms were statistically compared.

RESULTS

Greatest improvement in 135 eligible patients was observed for questions about (1) awareness of knee problems (Δ = 1.93, standard deviation [SD] = 1.38), (2) frequency of knee pain (Δ = 1.93, SD = 1.29), (3) degree of difficulty while twisting/pivoting on the injured knee (Δ = 1.88, SD = 1.13), (4) degree of difficulty while running (Δ = 1.67, SD = 1.30), and (5) being troubled by lack of confidence in the knee (Δ = 21.67, SD = 1.11). Least improvement was observed for questions about: (1) degree of difficulty while getting on/off the toilet (Δ = 0.94, SD = 0.96), (2) feel grinding or hear clicking when the knee moves (Δ= 0.90, SD = 1.25), 3) degree of difficulty while getting in/out of the bath (Δ= 0.88, SD = 1.00), (4) knee catches/hangs up during movement (Δ= 0.80, SD = 1.09), and (5) the ability to straighten the knee fully (Δ= 0.54, 1.44). There was greater improvement for the KOOS questions pertaining to meniscal versus mechanical symptoms (P < .00001).

CONCLUSIONS

KOOS symptoms as reported by subjects' responses to the questions pertaining to the frequency of knee pain, twisting/pivoting, running, squatting, and jumping showed the most improvement 1 year after isolated APM, whereas those relating to mechanical symptoms improved the least. Focusing on meniscal rather than mechanical symptoms may help surgeons better identify patients expected to benefit from APM.

LEVEL OF EVIDENCE

IV, retrospective analysis of prospectively collected data.

Artificial intelligence for MRI diagnosis of joints: a scoping review of the current state-of-the-art of deep learning-based approaches

Deep learning-based MRI diagnosis of internal joint derangement is an emerging field of artificial intelligence, which offers many exciting possibilities for musculoskeletal radiology. A variety of investigational deep learning algorithms have been developed to detect anterior cruciate ligament tears, meniscus tears, and rotator cuff disorders. Additional deep learning-based MRI algorithms have been investigated to detect Achilles tendon tears, recurrence prediction of musculoskeletal neoplasms, and complex segmentation of nerves, bones, and muscles. Proof-of-concept studies suggest that deep learning algorithms may achieve similar diagnostic performances when compared to human readers in meta-analyses; however, musculoskeletal radiologists outperformed most deep learning algorithms in studies including a direct comparison. Earlier investigations and developments of deep learning algorithms focused on the binary classification of the presence or absence of an abnormality, whereas more advanced deep learning algorithms start to include features for characterization and severity grading. While many studies have focused on comparing deep learning algorithms against human readers, there is a paucity of data on the performance differences of radiologists interpreting musculoskeletal MRI studies without and with artificial intelligence support. Similarly, studies demonstrating the generalizability and clinical applicability of deep learning algorithms using realistic clinical settings with workflow-integrated deep learning algorithms are sparse. Contingent upon future studies showing the clinical utility of deep learning algorithms, artificial intelligence may eventually translate into clinical practice to assist detection and characterization of various conditions on musculoskeletal MRI exams.

Relationship Between Magnetic Resonance Imaging Features and Knee Pain Over Six Years in Knees Without Radiographic Osteoarthritis at Baseline

Objective

To explore whether magnetic resonance imaging (MRI) features suggestive of knee osteoarthritis (OA) are associated with presence of knee pain in possible early‐stage OA development.

Methods

We included 294 participants from the Osteoarthritis Initiative (mean ± SD age 50 ± 3 years; 50% women) with baseline Kellgren/Lawrence grade of 0 in both knees, all of whom had received knee MRIs at 4 different time points over 6 years (baseline, 24, 48, and 72 months). Using a linear mixed model (knees matched within individuals), we studied whether MRI features (meniscal body extrusion [in mm], cartilage area loss [score 0–39], cartilage full thickness loss [range 0–16], osteophytes [range 0–29], meniscal integrity [range 0–10], bone marrow lesions [BMLs] including bone marrow cysts [range 0–20], Hoffa‐ or effusion‐synovitis [absent/present], and popliteal cysts [absent/present]) were associated with knee‐specific pain as reported on the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire using a 0–100 scale (worst to best).

Results

The differences in KOOS knee pain score for a knee with a 1 unit higher score on MRI were the following: meniscal extrusion –1.52 (95% confidence interval [95% CI] –2.35, –0.69); cartilage area loss –0.23 (95% CI –0.48, 0.02); cartilage full thickness loss –1.04 (95% CI –1.58, –0.50); osteophytes –0.32 (95% CI –0.61, –0.03); meniscal integrity –0.28 (95% CI –0.58, 0.02); BMLs including potential cysts –0.19 (95% CI –0.55, 0.16); synovitis 0.23 (95% CI –1.14, 1.60); and popliteal cysts 0.86 (95% CI –0.56, 2.29).

Conclusion

Meniscal extrusion, full thickness cartilage loss, and osteophytes are associated with having more knee pain. Although these features may be relevant targets for future trials, the clinical relevance of our findings is unclear because no feature was associated with a clinically important difference in knee pain.

Meniscal and Mechanical Symptoms Are Associated with Cartilage Damage, Not Meniscal Pathology

BACKGROUND

Traditionally defined "meniscal" and "mechanical" symptoms are thought to arise from meniscal tears. Yet meniscal tears and cartilage damage commonly coexist in symptomatic knees. To better characterize the primary driver of these symptoms, we investigated whether the presence of preoperative patient-reported knee symptoms (PRKS), including knee catching/locking, grinding/clicking/popping, and pain with pivoting, are associated with various intra-articular pathological conditions diagnosed at knee arthroscopy.

METHODS

We collected prospective data from 565 consecutive patients who underwent knee arthroscopy from 2012 to 2019 and had PRKS collected via the Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaire. The diagnosis of meniscal pathology and concomitant cartilage damage was confirmed and classified intraoperatively. We used multivariable regression models, adjusting for possible confounders, to examine the association of specific pathological conditions of the knee with the presence of preoperative PRKS.

RESULTS

Tricompartmental cartilage damage was strongly associated with significantly worse PRKS, with an increase of 0.33 point (95% confidence interval [CI] = 0.08 to 0.58; p = 0.01) on a 0 to 4-point scale. We did not observe an association between meniscal pathology and preoperative PRKS.

CONCLUSIONS

Contrary to current dogma, this study demonstrates that traditionally defined "meniscal" and "mechanical" knee symptoms are strongly associated with the burden and severity of underlying cartilage damage rather than with specific meniscal pathology.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Molecular biology of meniscus pathology: Lessons learned from translational studies and mouse models

Injury to any individual structure in the knee interrupts the overall function of the joint and initiates a cascade of biological and biomechanical changes whose endpoint is often osteoarthritis (OA). The knee meniscus is an integral component of knee biomechanics and may also contribute to the biological homeostasis of the joint. Meniscus injury altering knee function is associated with a high risk of OA progression, and may also be involved in the initiation of OA. As the relationship between meniscus injury and OA is very complex; despite the availability of transcript level data on human meniscus injury and meniscus mediated OA, mechanistic studies are lacking, and available human data are difficult to validate in the absence of patient-matched noninjured control tissues. As similarities exist between human and mouse knee joint structure and function, investigators have begun to use cutting-edge genetic and genomic tools to examine the usefulness of the mouse as a model to study the intricate relationship between meniscus injury and OA. In this review, we use evidence from human meniscus research to identify critical barriers hampering our understanding of meniscus injury induced OA and discuss strategies to overcome these barriers, including those that can be examined in a mouse model of injury-mediated OA.

Meniscal Lesions in Geriatric Population: Prevalence and Association with Knee Osteoarthritis

OBJECTIVE

This study evaluated the prevalence of different types of meniscal lesions among elderly patients with knee pain. Moreover, this study assessed the relationship between meniscal lesions and the presence of radiographic knee osteoarthritis (OA) in the elderly population.

METHODS

The radiographs and magnetic resonance images of one knee out of 306 patients with knee pain aged 65-89 years were reviewed for knee OA and meniscal lesions. The prevalence of different types of meniscal lesions was calculated, and the relationship between the prevalence of meniscal lesion types and the presence of radiographic knee OA was analyzed.

RESULTS

Among 306 participants, 274 (89.5%) showed radiographic knee OA. We found one or more meniscal lesion(s) in 93% of the total subjects, in 94% of all patients with knee OA, and in 84% of all patients without knee OA. The prevalence of surgically target, possible-target, and nontarget lesions were 24%, 72%, and 69%, respectively. The prevalence of surgically target lesions was significantly higher in patients with knee OA than in those without it. The most common lesion observed was meniscal extrusion, followed by the horizontal and complex meniscal tears.

CONCLUSIONS

Our results demonstrated that meniscal damage is considerably prevalent among elderly individuals with knee pain, especially in those with knee OA. The fact that surgically target and possible-target lesions constitute a substantial proportion of these lesions should be considered in the clinical approach to these patients.

Early Magnetic Resonance Imaging-Based Changes in Patients With Meniscal Tear and Osteoarthritis: Eighteen-Month Data From a Randomized Controlled Trial of Arthroscopic Partial Meniscectomy Versus Physical Therapy

OBJECTIVE

The present study was undertaken to evaluate changes in knee magnetic resonance imaging (MRI) findings over the course of 18 months in subjects with osteoarthritic change and meniscal tear treated with arthroscopic partial meniscectomy (APM) or nonoperatively with physical therapy (PT).

METHODS

We used 18-month follow-up data from the Meniscal Tear in Osteoarthritis Research Trial. MRI results were read with reference to the MRI Osteoarthritis Knee Score. We focused on 18-month change in bone marrow lesions (BMLs), cartilage thickness, cartilage surface area, osteophyte size, effusion-synovitis, and Hoffa-synovitis. We used multinomial logistic regression to assess associations between MRI-based changes in each feature and treatment type.

RESULTS

A total of 351 subjects were randomized, and 225 had both baseline and 18-month MRI results. In both treatment groups, patients experienced substantial changes in several MRI-based markers. In 60% of the APM group, versus 33% of the PT group, cartilage surface area damage advanced in ≥2 subregions (adjusted odds ratio 4.2 [95% confidence interval 2.0-9.0). Patients who underwent APM also had greater advancement in scores for osteophytes and effusion-synovitis. We did not find significant associations between treatment type and change in cartilage thickness, BMLs, or Hoffa-synovitis.

CONCLUSION

This cohort of patients with meniscal tear and osteoarthritis showed marked advancement in MRI-based features over 18 months. Patients treated with APM showed more advancement in some features compared to those treated nonoperatively. The clinical relevance of these early findings is unknown and requires further study.

Deep convolutional neural network-based detection of meniscus tears: comparison with radiologists and surgery as standard of reference

OBJECTIVE

To clinically validate a fully automated deep convolutional neural network (DCNN) for detection of surgically proven meniscus tears.

MATERIALS AND METHODS

One hundred consecutive patients were retrospectively included, who underwent knee MRI and knee arthroscopy in our institution. All MRI were evaluated for medial and lateral meniscus tears by two musculoskeletal radiologists independently and by DCNN. Included patients were not part of the training set of the DCNN. Surgical reports served as the standard of reference. Statistics included sensitivity, specificity, accuracy, ROC curve analysis, and kappa statistics.

RESULTS

Fifty-seven percent (57/100) of patients had a tear of the medial and 24% (24/100) of the lateral meniscus, including 12% (12/100) with a tear of both menisci. For medial meniscus tear detection, sensitivity, specificity, and accuracy were for reader 1: 93%, 91%, and 92%, for reader 2: 96%, 86%, and 92%, and for the DCNN: 84%, 88%, and 86%. For lateral meniscus tear detection, sensitivity, specificity, and accuracy were for reader 1: 71%, 95%, and 89%, for reader 2: 67%, 99%, and 91%, and for the DCNN: 58%, 92%, and 84%. Sensitivity for medial meniscus tears was significantly different between reader 2 and the DCNN (p = 0.039), and no significant differences existed for all other comparisons (all p ≥ 0.092). The AUC-ROC of the DCNN was 0.882, 0.781, and 0.961 for detection of medial, lateral, and overall meniscus tear. Inter-reader agreement was very good for the medial (kappa = 0.876) and good for the lateral meniscus (kappa = 0.741).

CONCLUSION

DCNN-based meniscus tear detection can be performed in a fully automated manner with a similar specificity but a lower sensitivity in comparison with musculoskeletal radiologists.

Rates of knee arthroplasty within one-year of undergoing arthroscopic partial meniscectomy in England: temporal trends, regional and age-group variation in conversion rates

OBJECTIVE

The aim of this study was to determine the proportion of patients undergoing arthroscopic partial meniscectomy (APM) then subsequently receiving a knee arthroplasty within one or two years, with focus on patients over the age of 60 years and regional variation.

METHODS

Patients undergoing APM in England over 20-years (01-April-1997 to 31-March 2017) were identified in the national Hospital Episode Statistics (HES). The proportion of patients undergoing arthroplasty in the same knee within one or two years of APM was determined and trends were analysed over time nationally and by NHS Clinical Commissioning Group (CCG) region.

RESULTS

806,195 APM patients were eligible for analysis with at least one-year of follow up and 746,630 with two-years. The odds of arthroplasty conversion within one year increased over the study period (odds ratio [OR] 3.10 within 1-year in 2014 vs 2000; 95% confidence interval [CI] 2.75-3.50). For patients undergoing APM aged 60 years or older in 2015-16, 9.9% (1689/17,043; 95% CI 9.5-10.4) underwent arthroplasty within 1-year and, in 2014-15, 16.6% (3100/18,734; 95% CI 16.0-17.1) underwent arthroplasty within 2-years. There was greater than 10-fold variation by CCG.

CONCLUSIONS

Over the study period, the proportion of patients undergoing arthroplasty within one-year of APM increased. In 2015-16, of patients aged 60 years or older who underwent APM, 10% subsequently underwent knee arthroplasty within one year (17% within two years in 2014-15) and there was a high level of regional variation in this outcome. The development and adoption of national treatment guidance is recommended to improve and standardise treatment selection.

Arthroscopic meniscal surgery: a national society treatment guideline and consensus statement

AIMS

The aim of the British Association for Surgery of the Knee (BASK) Meniscal Consensus Project was to develop an evidence-based treatment guideline for patients with meniscal lesions of the knee.

MATERIALS AND METHODS

A formal consensus process was undertaken applying nominal group, Delphi, and appropriateness methods. Consensus was first reached on the terminology relating to the definition, investigation, and classification of meniscal lesions. A series of simulated clinical scenarios was then created and the appropriateness of arthroscopic meniscal surgery or nonoperative treatment in each scenario was rated by the group. The process was informed throughout by the latest published, and previously unpublished, clinical and epidemiological evidence. Scenarios were then grouped together based upon the similarity of clinical features and ratings to form the guideline for treatment. Feedback on the draft guideline was sought from the entire membership of BASK before final revisions and approval by the consensus group.

RESULTS

A total of 45 simulated clinical scenarios were refined to five common clinical presentations and six corresponding treatment recommendations. The final guideline stratifies patients based upon a new, standardized classification of symptoms, signs, radiological findings, duration of symptoms, and previous treatment.

CONCLUSION

The 2018 BASK Arthroscopic Meniscal Surgery Treatment Guidance will facilitate the consistent identification and treatment of patients with meniscal lesions. It is hoped that this guidance will be adopted nationally by surgeons and help inform healthcare commissioning guidance. Validation in clinical practice is now required and several areas of uncertainty in relation to treatment should be a priority for future high-quality prospective studies. Cite this article: Bone Joint J 2019;101-B:652-659.

T2 mapping of the meniscus is a biomarker for early osteoarthritis

Purpose

To evaluate in vivo T₂ mapping as quantitative, imaging-based biomarker for meniscal degeneration in humans, by studying the correlation between T₂ relaxation time and degree of histological degeneration as reference standard.

Methods

In this prospective validation study, 13 menisci from seven patients with radiographic knee osteoarthritis (median age 67 years, three males) were included. Menisci were obtained during total knee replacement surgery. All patients underwent pre-operative magnetic resonance imaging using a 3-T MR scanner which included a T₂ mapping pulse sequence with multiple echoes. Histological analysis of the collected menisci was performed using the Pauli score, involving surface integrity, cellularity, matrix organization, and staining intensity. Mean T₂ relaxation times were calculated in meniscal regions of interest corresponding with the areas scored histologically, using a multi-slice multi-echo postprocessing algorithm. Correlation between T₂ mapping and histology was assessed using a generalized least squares model fit by maximum likelihood.

Results

The mean T₂ relaxation time was 22.4 ± 2.7 ms (range 18.5–27). The median histological score was 10, IQR 7–11 (range 4–13). A strong correlation between T₂ relaxation time and histological score was found (r_s = 0.84, CI 95% 0.64–0.93).

Conclusion

In vivo T₂ mapping of the human meniscus correlates strongly with histological degeneration, suggesting that T₂ mapping enables the detection and quantification of early compositional changes of the meniscus in knee OA.

Key Points

• Prospective histology-based study showed that in vivo T₂mapping of the human meniscus correlates strongly with histological degeneration.

• Meniscal T₂mapping allows detection and quantifying of compositional changes, without need for contrast or special MRI hardware.

• Meniscal T₂mapping provides a biomarker for early OA, potentially allowing early treatment strategies and prevention of OA progression.

Electronic supplementary material

The online version of this article (10.1007/s00330-019-06091-1) contains supplementary material, which is available to authorized users.

Adverse outcomes after arthroscopic partial meniscectomy: a study of 700 000 procedures in the national Hospital Episode Statistics database for England

BACKGROUND

Arthroscopic partial meniscectomy is one of the most common orthopaedic procedures worldwide. Clinical trial evidence published in the past 6 years, however, has raised questions about the effectiveness of the procedure in some patient groups. In view of concerns about potential overuse, we aimed to establish the true risk of serious complications after arthroscopic partial meniscectomy.

METHODS

We analysed national Hospital Episode Statistics data for all arthroscopic partial meniscectomies done in England between April 1, 1997, and March 31, 2017. Simultaneous or staged (within 6 months) bilateral cases were excluded. We identified complications occurring in the 90 days after the index procedure. The primary outcome was the occurrence of at least one serious complication within 90 days, which was defined as either myocardial infarction, stroke, pulmonary embolism, infection requiring surgery, fasciotomy, neurovascular injury, or death. Logistic regression modelling was used to identify factors associated with complications and, when possible, risk was compared with general population data.

FINDINGS

During the study period 1 088 782 arthroscopic partial meniscectomies were done, 699 965 of which were eligible for analysis. Within 90 days, serious complications occurred in 2218 (0·317% [95% CI 0·304-0·330]) cases, including 546 pulmonary embolisms (0·078% [95% CI 0·072-0·085]) and 944 infections necessitating further surgery (0·135% [95% CI 0·126-0·144]). Increasing age (adjusted odds ratio [OR] 1·247 per decade [95% CI 1·208-1·288) and modified Charlson comorbidity index (adjusted OR 1·860 per 10 units [95% CI 1·708-2·042]) were associated with an increased risk of serious complications. Female sex was associated with a reduced risk of serious complications (adjusted OR 0·640 [95% CI 0·580-0·705). The risk of mortality fell over time (adjusted OR 0·965 per year [95% CI 0·937-0·994]). Mortality, myocardial infarction, and stroke occurred less frequently in the study cohort than in the general population. The risks of infection and pulmonary embolism did not change during the study, and were significantly higher in the study cohort than in the general population. For every 1390 (95% CI 1272-1532) fewer knee arthroscopies done, one pulmonary embolism could be prevented. For every 749 (95% CI 704-801) fewer procedures done, one native knee joint infection could be prevented.

INTERPRETATION

Overall, the risk associated with undergoing arthroscopic partial meniscectomy was low. However, some rare but serious complications (including pulmonary embolism and infection) are associated with the procedure, and the risks have not fallen with time. In view of uncertainty about the effectiveness of arthroscopic partial meniscectomy, an appreciation of relative risks is crucial for patients and clinicians. Our data provide a basis for decision making and consent.

FUNDING

UK National Institute for Health Research.

National consensus on the definition, investigation, and classification of meniscal lesions of the knee

BACKGROUND

The aim of this study was to deliver standardised terminology for the identification and stratification of patients with meniscal lesions of the knee.

METHODS

A national group of expert surgeons was convened by the British Association for Surgery of the Knee (BASK) and a formal consensus process was undertaken following a validated methodology. A combination of nominal group techniques and an iterative Delphi process was used to develop and refine relevant definitions. Where appropriate, definitions were placed into categories to facilitate use in clinical practice and guideline development.

RESULTS

A degenerative meniscus develops progressively with degradation of meniscal tissue and this may be revealed by intra-meniscal high signal on magnetic resonance imaging (MRI). A meniscal tear was defined as a defect or split in the meniscocapsular complex, which can occur in a degenerative or non-degenerative meniscus. Degenerative meniscal lesions (high signal or tear) are frequent in the general population and are often incidental findings on knee MRI. Symptoms were defined and classified into three groups: (1) strongly suggestive of a treatable meniscal lesion, (2) potentially suggestive of a treatable meniscal lesion, (3) osteoarthritic. A strategy for radiological imaging (radiograph ± MRI) was agreed for the investigation of the patients with a possible meniscal tear. Meniscal lesions and tear patterns on MRI imaging were defined and classified with reference to potential treatability: (1) target, (2) possible target, (3) no target.

CONCLUSIONS

The agreed terminology will enable patients with meniscal lesions to be identified and stratified consistently in clinical practice, research and guideline development.

Editorial Commentary: Are We Running Out of Treatments for Osteoarthritis of the Knee?

A considerable body of literature with high-level evidence has been published in the past 15 years calling into question the value of arthroscopic surgery in treating osteoarthritis of the knee (OAK). This, plus recent guidelines advising against the use of conservative treatments such as hyaluronic viscosupplementation, threatens to limit patient access to treatment for a chronic disease state with no known cure. The disease burden of OAK is considerable and represents one of the largest health care dollar expenditures in the United States and the world. Orthopaedic surgeons are the primary specialty dealing with OAK and manage this disease from inception to the final endpoint of total joint arthroplasty. As the population ages and the incidence of OAK increases, we must find ways to improve our ability to show efficacy in our treatments and also promote innovative modalities and applications to ameliorate the disability and dysfunction associated with OAK. Arthroscopy is recognized as a global leader in the presentation of evidence and debate surrounding all treatments for OAK and plays an important role in improving knowledge and treatment efficacy.

Osteoarthritis year in review 2017: updates on imaging advancements

OBJECTIVE

This narrative review covers original research publications related to imaging advancements in osteoarthritis (OA) published in the English language between 1^st April 2016 and 30^th April 2017.

METHODS

Relevant human studies (excluding pre-clinical and in vitro studies), were searched and selected from PubMed database using the search terms of "osteoarthritis (OA)" in combination with "radiography", "magnetic resonance imaging (MRI)", "computed tomography (CT)", "ultrasound", "positron emission tomography (PET)," "single-photon emission computed tomography (SPECT)," and "scintigraphy". The included studies were sorted according to their relevance, novelty, and impact. Original research articles with both imaging advancements and novel clinical information were discussed in this review.

RESULTS

A large portion of the published studies were focused on MRI-based semi-quantitative and quantitative (morphological and structural) metrics of the knee joint to assess OA-related structural damages. New imaging technologies, such as PET, have been investigated for OA diagnosis and characterization, the delineation of predictive factors for OA progression, and to monitor the treatment responses.

CONCLUSION

Advanced imaging modalities play a pivotal role in OA research, and make a significant contribution to our understanding of OA diagnosis, pathogenesis, risk stratification, and prognosis.

Imaging of osteoarthritis-recent research developments and future perspective

In osteoarthritis research, imaging plays an important role in clinical trials and epidemiological observational studies. In this narrative review article, we will describe recent developments in imaging of osteoarthritis in the research arena, mainly focusing on literature evidence published within the past 3 years (2014-2017). We will primarily focus on MRI including advanced imaging techniques that are not currently commonly used in routine clinical practice, although radiography, ultrasound and nuclear medicine (radiotracer) imaging will also be discussed. Research efforts to uncover the disease process of OA as well as to discover a disease modifying OA drug continue. MRI continues to play a large role in these endeavors, while compositional MRI techniques will increasingly become important due to their ability to assess "premorphologic" biochemical changes of articular cartilage and other tissues in and around joints. Radiography remain the primary imaging modality for defining inclusion/exclusion criteria as well as an outcome measure in OA clinical trials, despite known limitations for visualization of OA features. Compositional MRI techniques show promise for predicting structural and clinical outcomes in OA research. Ultrasound can be a useful adjunct to radiography and MRI particularly for evaluation of hand OA. Newer imaging techniques such as hybrid PET/MRI may have a potential but require further research and validation.

Diagnostic Validity of Combining History Elements and Physical Examination Tests for Traumatic and Degenerative Symptomatic Meniscal Tears

BACKGROUND

The current approach to the clinical diagnosis of traumatic and degenerative symptomatic meniscal tears (SMTs) proposes combining history elements and physical examination tests without systematic prescription of imaging investigations, yet the evidence to support this diagnostic approach is scarce.

OBJECTIVE

To assess the validity of diagnostic clusters combining history elements and physical examination tests to diagnose or exclude traumatic and degenerative SMT compared with other knee disorders.

DESIGN

Prospective diagnostic accuracy study.

SETTINGS

Patients were recruited from 2 orthopedic clinics, 2 family medicine clinics, and from a university community.

PATIENTS

A total of 279 consecutive patients who underwent consultation for a new knee complaint.

METHODS

Each patient was assessed independently by 2 evaluators. History elements and standardized physical examination tests performed by a physiotherapist were compared with the reference standard: an expert physicians' composite diagnosis including a clinical examination and confirmatory magnetic resonance imaging. Participating expert physicians were orthopedic surgeons (n = 3) or sport medicine physicians (n = 2). Penalized logistic regression (least absolute shrinkage and selection operator) was used to identify history elements and physical examination tests associated with the diagnosis of SMT and recursive partitioning was used to develop diagnostic clusters.

MAIN OUTCOME MEASURES

Diagnostic accuracy measures were calculated including sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios (LR+/-) with associated 95% confidence intervals (CIs).

RESULTS

Eighty patients had a diagnosis of SMT (28.7%), including 35 traumatic tears and 45 degenerative tears. The combination a history of trauma during a pivot, medial knee pain location, and a positive medial joint line tenderness test was able to diagnose (LR+ = 8.9; 95% CI 6.1-13.1) or exclude (LR- = 0.10; 95% CI 0.03-0.28) a traumatic SMT. Combining a history of progressive onset of pain, medial knee pain location, pain while pivoting, absence of valgus or varus knee misalignment, or full passive knee flexion was able to moderately diagnose (LR+ = 6.4; 95% CI 4.0-10.4) or exclude (LR- = 0.10; 95% CI 0.03-0.31) a degenerative SMT. Internal validation estimates were slightly lower for all clusters but demonstrated positive LR superior to 5 and negative LR inferior to 0.2 indicating moderate shift in posttest probability.

CONCLUSION

Diagnostic clusters combining history elements and physical examination tests can support the differential diagnosis of SMT. These results represent the initial derivation of the clusters and external validation is mandatory.

LEVEL OF EVIDENCE

I.