Risk factors for symptomatic knee osteoarthritis fifteen to twenty-two years after meniscectomy

Unraveling sex-specific risks of knee osteoarthritis before menopause: Do sex differences start early in life?

OBJECTIVE

Sufficient evidence within the past two decades have shown that osteoarthritis (OA) has a sex-specific component. However, efforts to reveal the biological causes of this disparity have emerged more gradually. In this narrative review, we discuss anatomical differences within the knee, incidence of injuries in youth sports, and metabolic factors that present early in life (childhood and early adulthood) that can contribute to a higher risk of OA in females.

DESIGN

We compiled clinical data from multiple tissues within the knee joint-since OA is a whole joint disorder-aiming to reveal relevant factors behind the sex differences from different perspectives.

RESULTS

The data gathered in this review indicate that sex differences in articular cartilage, meniscus, and anterior cruciate ligament are detected as early as childhood and are not only explained by sex hormones. Aiming to unveil the biological causes of the uneven sex-specific risks for knee OA, we review the current knowledge of sex differences mostly in young, but also including old populations, from the perspective of (i) human anatomy in both healthy and pathological conditions, (ii) physical activity and response to injury, and (iii) metabolic signatures.

CONCLUSIONS

We propose that to close the gap in health disparities, and specifically regarding OA, we should address sex-specific anatomic, biologic, and metabolic factors at early stages in life, as a way to prevent the higher severity and incidence of OA in women later in life.

Post-Traumatic Osteoarthritis, Psychological Health, and Quality of Life After Lower Limb Injury in U.S. Service Members

INTRODUCTION

The aims of this project were to assess (1) the prevalence and timing of post-traumatic osteoarthritis (PTOA) after a traumatic lower limb injury, (2) the risk of PTOA based on injury type, and (3) the association of PTOA with psychological health and quality of life (QoL).

MATERIALS AND METHODS

The Wounded Warrior Recovery Project (WWRP) database and the Expeditionary Medical Encounters Dataset were queried to identify service members injured during deployment. The Military Health System Data Repository was utilized to extract medical record data to identify individuals with PTOA. Data on PTSD, depression symptoms, and QoL were extracted from the WWRP.

RESULTS

Of the 2,061 WWRP participants with lower limb injuries, 124 (6%) were diagnosed with PTOA, with first PTOA diagnosis occurring 3.8 ± 3.1 years after injury. Of the injury categories identified, only fractures were associated with high odds of lower limb PTOA (adjusted odds ratio [OR] = 3.92, 95% confidence interval [CI]: 2.38, 6.44). Individuals with PTOA diagnoses reported lower QoL scores relative to those without PTOA (F(1,2057) = 14.21, B = -0.05, P < .05). Additionally, rates of PTSD and depression symptoms were high but not different between those with or without PTOA.

CONCLUSIONS

Despite a low prevalence of lower limb PTOA in our study, fractures increased the risk of PTOA after deployment-related injuries. Additionally, those with PTOA reported lower QoL scores relative to those without PTOA. The findings of this study highlight the personalized needs of patients with trauma beyond just the repair of the immediate injury.

Lateral Unicompartmental Knee Arthroplasty for Osteoarthritis Secondary to Lateral Meniscectomy: High Functional Results and Survivorship and Low Osteoarthritis Progression at a Mean 10 Years of Follow-up

BACKGROUND

Meniscectomy, whether partial or total, is a common knee surgery, but it considerably increases the risk of knee osteoarthritis (OA). Lateral meniscectomy has more severe consequences than medial meniscectomy, leading to faster OA progression and worse clinical outcomes. Unicompartmental knee arthroplasty (UKA) is a suitable treatment option for lateral OA and has demonstrated better outcomes than total knee arthroplasty (TKA). The aims of this study were to evaluate the clinical and functional results, OA progression in the medial compartment, and implant survivorship following lateral UKA in patients with OA secondary to lateral meniscectomy and to compare these outcomes with those of patients who underwent lateral UKA for primary lateral OA.

METHODS

Between 2001 and 2017, 214 lateral UKAs were performed. Of these, 42 were performed for OA secondary to lateral meniscectomy. The control group was composed of patients who underwent lateral UKA for primary lateral OA and was formed through a 1:1 case-control matching process based on sex, age, body mass index, and operation date. The outcomes that were studied included range of motion, Knee Society Score, University of California Los Angeles (UCLA) Activity Score, Tegner Activity Scale, Forgotten Joint Score, visual analog scale for pain, OA progression in the medial compartment, and implant survivorship.

RESULTS

At a mean follow-up of 10.2 years, both groups demonstrated significant improvements (p < 0.01) after lateral UKA in all clinical and functional scores except the UCLA Activity Score and Tegner Activity Scale. No significant differences in clinical and functional scores were found between the groups. However, patients with OA secondary to meniscectomy exhibited significantly less OA progression in the medial compartment (p = 0.035) and higher 10-year implant survival (97.6% versus 83.3%).

CONCLUSIONS

Lateral UKA is an effective treatment option for OA secondary to lateral meniscectomy, providing excellent functional outcomes and survivorship. Patients with post-meniscectomy OA exhibited less OA progression in the medial compartment than patients with primary OA and, consequently, had better 10-year implant survivorship.

LEVEL OF EVIDENCE

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

More Is Not Merrier: Increasing Numbers of All-Inside Implants Do Not Correlate with Higher Odds of Revision Surgery

The purpose of this study was to evaluate the relationship between the number of all-inside meniscal repair implants placed and the risk of repair failure. We hypothesized that the use of higher numbers of all-inside meniscus repair implants would be associated with increased failure risk. A retrospective chart review identified 351 patients who underwent all-inside meniscus repair between 2006 and 2013 by a sports medicine fellowship-trained orthopaedic surgeon at a single institution. Patient demographics (age, body mass index [BMI], sex) and surgical data (number of implants used, concomitant anterior cruciate ligament reconstruction [cACLR], and tear type/size/location) were recorded. Patients who received repairs in both menisci or who had follow-up < 1-year postoperatively were excluded. Repair failure was identified through chart review or patient interviews defined as a revision surgery on the index knee such as partial meniscectomy, total knee arthroplasty, meniscus transplant, or repeat repair. Logistic regression modeling was utilized to evaluate the relationship between the number of implants used and repair failure. A total of 227 all-inside meniscus repairs were included with a mean follow-up of 5.0 ± 3.0 years following surgery. Repair failure was noted in 68 knees (30.3%)-in 28.1% of knees with fewer than four implants and in 35.8% of knees with four or more implants (p = 0.31). No significant increase in failure was observed with increasing number of all-inside medial (odds ratio [OR]: 1.15; 95% confidence interval [CI]: 0.79-1.7; p = 0.46) or lateral (OR: 0.86; 95% CI: 0.47-1.57; p = 0.63) implants after controlling for patient age, BMI, cACLR, tear type, or size. Tears of the lateral meniscus located in the red-white and white-white zones had lower odds of failure (OR: 0.14; 95% CI: 0.02-0.88; p = 0.036) than tears within the red-red zone, and patients with cACLR had lower odds of repair failure (OR: 0.40; 95% CI: 0.18-0.86, p = 0.024) than those without. The number of all-inside implants placed during meniscus tear repair did not affect the likelihood of repair failure leading to reoperation after controlling for BMI, age, tear type, size, location, and cACLR. LEVEL OF EVIDENCE:  III.

Is Arthroscopic Meniscectomy Associated With an Increased Risk of Total Knee Arthroplasty for Claimants in the Workers' Compensation System? A 10-Year Study of Workers' Compensation Claims From a Large Nationwide Workers' Compensation Insurance Carrier

BACKGROUND

Total knee arthroplasty (TKA) is a commonly performed knee surgery and prior arthroscopic meniscectomy (AM) has been linked to an increased risk of TKA in the general population.

OBJECTIVE

To study the relationship between AM and TKA among injured workers whose medical care is paid for under workers' compensation (WC).

METHOD

A total of 17,247 lost-time claims depicting all arthroscopic knee surgical procedures performed from 2007 to 2017 were followed to the end of 2022 and analyzed.

RESULTS

The odds ratio of undergoing a TKA for those with a preceding AM is 2.20, controlling for age, sex, and attorney involvement.

CONCLUSIONS

Undergoing an AM is associated with an increased risk of TKA in WC claimants.

Comparison of short-term clinical outcomes between open-wedge high tibial osteotomy and tibial condylar valgus osteotomy

BACKGROUND

This study aimed to compare radiological features and short-term clinical outcomes between open-wedge high tibial osteotomy (OWHTO) and tibial condylar valgus osteotomy (TCVO), to provide information facilitating decision-making regarding those two procedures.

METHODS

Twenty-seven cases involving 30 knees that had undergone OWHTO (HTO group) and eighteen cases involving 19 knees that had undergone TCVO (TCVO group) for medial compartment knee osteoarthritis (OA) were retrospectively evaluated. Patient characteristics, severity of knee OA, lower limb alignment, joint congruity and instability were measured from standing full-length leg and knee radiographs obtained before and 1 year after surgery. Range of motion in the knee joint was measured and Knee Injury and Osteoarthritis Outcome Score (KOOS) was obtained to evaluate clinical results preoperatively and 1 year postoperatively.

RESULTS

Mean age was significantly higher in the TCVO group than in the HTO group. Radiological features in the TCVO group included greater frequencies of advanced knee OA, varus lower limb malalignment, higher joint line convergence angle, and varus-valgus joint instability compared to the HTO group before surgery. However, alignment of the lower limb and joint instability improved to comparable levels after surgery in both groups. Maximum flexion angles were significantly lower in the TCVO group than in the HTO group both pre- and postoperatively. Mean values in all KOOS subscales recovered similarly after surgery in both groups, although postoperative scores on three subscales (Symptom, Pain, and ADL) were lower in the TCVO group (Symptom: HTO, 79.0; TCVO, 67.5; Pain: HTO, 80.5; TCVO, 71.1; ADL: HTO, 86.9; TCVO, 78.0).

CONCLUSIONS

Both osteotomy procedures improved short-term clinical outcomes postoperatively. TCVO appears preferable in cases of advanced knee OA with incongruity and high varus-valgus joint instability. An appropriate choice of osteotomy procedure is important to obtain favorable clinical outcomes.

Enhancing Meniscal Repair: Investigating the Impact of an Exogenous Fibrin Clot

This study conducted a comparative analysis of meniscal rupture repair, evaluating outcomes with and without the application of an exogenous fibrin clot to enhance meniscus repair. The research incorporated a relatively large sample size (24 patients) and employed a randomized control group with similar age characteristics and morphological types of meniscal ruptures as the study group. Notably, two postoperative follow-up times, at the third and 12th postoperative months, were utilized, distinguishing this study from related research. In the third postoperative month assessment, the fibrin clot technique demonstrated a significant advantage over simple stapling, as evidenced by markedly improved Tegner Lysholm Knee Scoring Scale (TLKSS) and Modified Cincinnati Rating System Questionnaire (MCRSQ) clinical assessment scores. Subsequent MRI scans at 12 months post-treatment revealed a high rate (91.67%) of complete healing in menisci treated with a fibrin clot, with only 4.17% exhibiting incomplete healing. This study expanded on previous research by including longitudinal ruptures and bucket-handle ruptures in addition to radial ruptures. The findings highlight a notable early improvement (third postoperative month) in the clinical assessment of longitudinal and bucket-handle ruptures treated with a fibrin clot during meniscus repair. This research contributes valuable insights into the efficacy of fibrin clots in enhancing meniscus repair, suggesting positive clinical and radiological outcomes, especially in the early stages postoperatively.

Predilection of Patellofemoral Cartilage Lesions in Patients with Posterior Medial Meniscal Root Lesions

OBJECTIVE

The present study aims to compare the presence and severity of patellofemoral osteoarthritis between patients with root lesions and non-root lesions.

DESIGN

A total of 102 patients were included in this study (51 root lesions and 51 non-root lesions). The root lesion cohort was matched to a non-root lesion cohort based on sex, body mass index, and age at the time of surgery. Radiographic evaluation with modified Outerbridge scoring of MRI of the knee was performed to determine the severity of degeneration of the knee joint preoperatively. Mann-Whitney and Independent t tests were used to compare the groups.

RESULTS

The root lesion group had statistically greater Outerbridge patella scores (M = 2.45 ± 1.12) and trochlear scores (M = 2.27 ± 1.37) than the non-root lesion patients (M = 1.78 ± 1.30, P = 0.006, and M = 1.55 ± 1.40, P = 0.010, respectively). When using a new scale for grading patellofemoral arthritis, the root lesion group had statistically greater scores (M = 8.33 ± 3.38) than the non-root lesion patients (M = 5.67 ± 3.07) (P < 0.001).

CONCLUSION

Patients with root lesions have a greater degree of patellofemoral cartilage lesions than patients without root lesions. The presence of cartilage lesions preoperatively in root lesion patients has presented the question of whether repair is worthwhile or if one should delay surgery until arthroplasty is indicated. Future research should be carried out on outcomes of root repair surgery in patients with patellofemoral cartilage lesions, in addition to considering the patient's age, activity level, and other risk factors.

ACTIfit™: 38% full resorption at 8 years in a cohort of 18 cases

BACKGROUND

Preserving meniscal tissue is a major priority in young, physically active patients. Extensive meniscal defects may result in exercise pain and premature osteoarthritis. ACTIfit™ is a synthetic meniscal substitute that may improve short-term functional scores via biological integration with meniscal tissue regeneration. However, long-term data on the lifespan and chondroprotective effect of this newly formed tissue are lacking. The primary objective of this study was to assess the biological integration of ACTIfit™ based on magnetic resonance imaging (MRI) findings. The secondary objective was to evaluate long-term clinical outcomes.

HYPOTHESIS

The ACTIfit™ meniscal substitute undergoes biological integration over time, suggesting chondroprotective potential.

MATERIALS AND METHODS

A 2014 report by Baynat et al. described the 2-year clinical and radiological outcomes of 18 patients after ACTIfit™ implantation at the Clermont-Tonnerre military teaching hospital (Brest, France). The patients had chronic knee pain of at least 6 months' duration after failure of primary meniscal surgery with segmental meniscal defects. Mean age was 34.0±7.9 years. A concomitant procedure was performed in 13 (60%) patients, including osteotomy in 8 and ligament reconstruction in 5. For the current study, the clinical and radiological follow-up was at least 8 years. Assessments were with the Genovese grading scale for substitute morphology on MRI scans, International Cartilage Research Society (ICRS) score for osteoarthritis progression, and Lysholm score for clinical outcome. Failure was defined as total substitute resorption (Genovese morphology grade 1) or revision surgery with implant removal, conversion to meniscus allografting, or arthroplasty.

RESULTS

MRI scans were available for 12 (66%) patients. The reason for not having long-term MRI scans was surgery for substitute removal or arthroplasty in 3 of the remaining 6 patients. Complete implant resorption (Genovese grade 1) was noted in 7/12 (58%) patients and osteoarthritis progression to ICRS grade 3 in 4/12 (33%) patients. At last follow-up, the mean Lysholm score was significantly improved vs. baseline (79±15 vs. 55±13, P=0.005).

CONCLUSION

The frequency of complete ACTIfit™ resorption 8 years after implantation was high. This finding argues against ability of this substitute to induce the regeneration of durable meniscal tissue with a chondroprotective effect. The clinical outcome score was significantly improved at last follow-up. However, no conclusions can be drawn regarding the effectiveness of ACTIfit™ given the high frequency of concomitant surgical procedures.

LEVEL OF EVIDENCE

IV, retrospective observational cohort.

Treatment for Acute Anterior Cruciate Ligament Tear in Young Active Adults

BACKGROUND: Anterior cruciate ligament (ACL) injury of the knee is common in young active adults and often has severe and sometimes lifelong consequences. The clinical management of this injury remains debated. A prior trial of early versus delayed optional ACL repair showed no differences in outcomes at 2 years. METHODS: We present the 11-year follow-up of a randomized clinical trial involving 121 young active adults (mean age 26yo, 74% male) with an acute sports-related ACL tear. We compared patient-reported and radiographic outcomes between those randomized to receive early ACL reconstruction (ACLR) followed by exercise therapy (N=62) and those treated with early exercise therapy plus optional delayed ACLR (N=59). The primary end point at 11 years was change from baseline in the mean of four subscales of the Knee Injury and Osteoarthritis Outcome Score (KOOS) — pain, symptoms, function in sports and recreation, and knee-related quality of life (KOOS4; range of scores, 0 [worst] to 100 [best]; minimal important change=9). RESULTS: In all, 88% of the cohort followed up at 11 years (53/62 in the early vs. 54/59 in the optional late ACL repair groups), and 52% of those assigned to optional delayed ACLR underwent ACLR. Mean improvement in KOOS4 from baseline to 11 years was 46 points for those assigned to early ACLR plus exercise therapy and 45 points for those assigned to exercise therapy plus optional delayed ACLR (between-group difference, 1.6 points; 95% confidence interval [CI], −8.8 to 5.6; P=0.67 after adjustment for baseline score, full analysis set). About two thirds of the full cohort reported meeting the case definition for a “patient-acceptable symptom state” (KOOS4 patient-acceptable symptom state threshold value=79), whereas 44% had developed radiographic osteoarthritis of their injured knee. Mean summed incident radiographic osteoarthritis feature scores, scores range from 0 to 30 where higher scores indicate more severe joint damage, were 2.4 for the group assigned to early ACLR and 1.0 for the group assigned to exercise therapy plus optional delayed ACLR (mean difference, 1.0; 95% CI, 0.1 to 1.9). CONCLUSIONS: At 11-year follow-up, among young active adults with acute ACL tears assigned to early ACLR plus exercise versus initial exercise therapy with the option of delayed ACLR, there were no differences in patient-reported outcomes. (Funded by the Swedish Research Council; ISRCTN number, ISRCTN84752559.)

"You're stuck in the middle here": a qualitative study of GPs' experiences of managing knee pain attributed to a degenerative meniscal tear

BACKGROUND

Exercise is the recommended first-line therapy for a degenerative meniscal tear (DMT). Despite this, knee pain attributed to DMTs are a common presentation to specialist orthopaedic clinics. In the primary care setting, the general practitioner (GP) plays a central role in managing patients with knee pain, but to date their perspective has not been explored in relation to DMTs. This study explored GPs' experiences of managing people with knee pain attributed to a DMT.

METHODS

A qualitative research design was adopted and practices in the South and Mid-West of Ireland were contacted via recruitment emails circulated through professional and research networks. Interested GPs contacted the researchers via email, and purposive and snowball sampling was used for recruitment. Semi-structured interviews were conducted online or over the telephone. Interviews were digitally recorded and transcribed. Data was analysed using an inductive approach to thematic analysis. Ethical approval was granted by the Irish College of General Practitioners (ICGP_REC_21_0031).

RESULTS

Seventeen semi-structured one-on-one interviews were conducted. Three main themes were identified with related subthemes: (1) GPs' experiences of relational aspects of care, (2) GP beliefs about what constitutes best care for patients with a DMT, and (3) how GP practice is enacted within the current healthcare setting. GPs described the challenge of maintaining a strong clinical alliance, while managing perceived patient expectations of a 'quick fix' and advanced imaging. They reported slowing down clinical decisions and feeling 'stuck' with limited options when conservative treatment had failed. GPs believed that exercise should be the core treatment for DMTs and emphasised engaging patients in an active approach to recovery. Some GPs believed arthroscopy had a role in circumstances where patients didn't improve with physiotherapy. Limited access to public physiotherapy and orthopaedic services hampered GPs' management plans and negatively impacted patient outcomes.

CONCLUSIONS

GP beliefs around what constitutes best care for a DMT generally aligned with the evidence base. Nonetheless, there was sometimes tension between these beliefs and the patient's own treatment expectations. The ability to enact their beliefs was hampered by limited access to conservative management options, sometimes leading to early escalation of care.

Effects of Lateral Opening-Wedge Distal Femoral Osteotomy on Meniscal Allograft Transplantation: A Biomechanical Evaluation

Background

Lateral meniscal deficiency with valgus malalignment increases the rate of lateral compartment osteoarthritis. Lateral meniscal allograft transplantation (LMAT) with a concomitant varus-producing opening-wedge distal femoral osteotomy (DFO) is an option yet to be evaluated biomechanically.

Purpose/Hypothesis

The purpose of this study was to clarify the biomechanical effects of the realignment procedure in the setting of LMAT. We hypothesized that (1) given the dependence of the lateral compartment on the lateral meniscus, a DFO and increasing degrees of varus would be insufficient to restore lateral compartment pressures to normal from a lateral meniscus-deficient state, and that (2) LMAT would restore lateral compartment pressures to the intact state while DFO would decrease lateral compartment pressures for any given state of the meniscus.

Study Design

Controlled laboratory study.

Methods

Ten cadaveric knees underwent opening-wedge varus-producing DFO secured by an external fixator. Anatomic alignment was standardized to 6° of mechanical valgus, and each joint was tested in full extension. Submeniscal placement of thin film pressure sensors allowed for the recording of contact pressure, peak contact pressure, and contact area. The specimens were loaded on a biaxial dynamic testing machine with loading angles between 9° valgus and 6° varus of mechanical alignment. Conditions tested included intact meniscus, meniscal deficiency, and meniscal transplantation.

Results

Isolated varus-producing DFO to 6° in the meniscus-deficient state failed to restore joint pressures and contact areas to the intact state, with significant changes in mean contact pressure (175%), mean peak contact pressure (135%), and contact area (-41%) (all P < .05 vs intact), while LMAT restored all outcome measures (all P > .05 compared with intact). After LMAT, every additional 1° of DFO correction contributed to a decrease in the mean contact pressure, peak pressure, and contact area of 5.6% (-0.0479 N/mm²), 5.9% (-0.154 N/mm²), and 1.4% (-6.99 mm²) for the lateral compartment and 7.3% (+0.034 N/mm²), 12.6% (+0.160 N/mm²), and 4.3% (+20.53 mm²) for the medial compartment, respectively.

Conclusion

Isolated DFO was inadequate to restore load distribution in meniscus-deficient knees, while concomitant LMAT restored near normal forces and improved the lateral compartment biomechanical profile.

Clinical Relevance

Our findings support the concomitant use of LMAT and varus-producing DFO in the setting of lateral meniscal deficiency with valgus malalignment. This study provides tools for the orthopaedic surgeon to individualize the correction for each patient.

Risk factors for the long-term incidence and progression of knee osteoarthritis in older adults: role of nonsurgical injury

Background

For one of the most chronic medical conditions, osteoarthritis, uncertainties remain on the impact of injury chronology, the role of repeat injury on the incidence/progression of this disease and the need for knee arthroplasty.

Objectives

To explore, in an older adult population, how nonsurgical knee injuries relate to osteoarthritis incidence/progression and the weight of independent risk factors for arthroplasty.

Design

A cohort study design evaluates the long-term impact of injuries on knee osteoarthritis outcomes.

Methods

Knees with no prior injury (n = 6358) and with at least one injury (n = 819) ⩽20 years before study inclusion were from the Osteoarthritis Initiative cohort. Sociodemographic, clinical and structural [X-ray, magnetic resonance imaging (MRI)] data at study inclusion and changes within 96 months were analysed. Statistics included a mixed model for repeated measurements, generalized estimating equations and multivariable Cox regression with covariates.

Results

At inclusion, knees with prior injury demonstrated greater incidence and severity of osteoarthritis (p ⩽ 0.001). At 96 months, there was a greater increase in symptoms [Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain, p = 0.002], joint space width (JSW, p = 0.039) loss, medial cartilage volume loss (CVL, p ⩽ 0.001) and bone marrow lesion size (BML, p ⩽ 0.049). Knees with/without injury at inclusion but with new ones over time had a pronounced increase in symptoms (all WOMAC scores, p ⩽ 0.001), JSW loss, lateral (without) and medial CVL, lateral (without) and medial meniscal extrusion and medial BML (without; all p ⩽ 0.030). Levels of lateral and medial meniscal extrusion (without) and symptoms (with/without; all WOMAC scores, p ⩽ 0.001) were all accentuated with a repeated new injury. Risk factors associated with the highest knee arthroplasty occurrence are new meniscal extrusion and new injury (p ⩽ 0.001).

Conclusion

This study highlights the importance of nonsurgical knee injury in older adults as an independent risk factor for knee osteoarthritis and arthroplasty. These data will be beneficial in clinical practice as they will help identify individuals at greater risk of significant disease progression and worst disease outcomes for a customized therapeutic approach.

Association of Medial Meniscal Volume With Decreased Joint Space Width After Medial Opening-Wedge High Tibial Osteotomy

Background

Medial opening-wedge high tibial osteotomy (MOWHTO) reduces contact stress by altering the weightbearing axis from the medial to the lateral compartment, relieves knee pain, and slows the progression of osteoarthritis.

Purpose/Hypothesis

To evaluate whether the volume of the medial meniscus affects outcomes after MOWHTO. It was hypothesized that reduced medial meniscal volume would be associated with worse midterm clinical and radiographic outcomes.

Study Design

Cohort study; Level of evidence, 3.

Methods

Included were 59 patients who underwent MOWHTO and had ≥4 years of follow-up data. The mean follow-up period was 66.5 ± 15.1 months (range, 48-110 months). The cohort was classified into 3 groups according to the status of the medial meniscus on arthroscopic examination before osteotomy: no meniscal tear, degenerative tear leading to partial meniscectomy, and degenerative tear leading to subtotal meniscectomy. The Hospital for Special Surgery score and Knee Society objective and functional scores were compared among the groups at 2 time points (preoperative and latest follow-up), and the medial joint space width (JSW) was compared among the groups at 3 time points (preoperative, 1 year postoperative, and latest follow-up).

Results

Overall, 9 patients had no meniscal tear, 20 patients underwent partial meniscectomy, and 30 patients underwent subtotal meniscectomy. The clinical scores improved significantly from preoperatively to the latest follow-up (P ≤ .001 for all), with no significant difference among the groups. Post hoc analysis indicated that at the latest follow-up, JSW was significantly lower in the subtotal meniscectomy group compared with the no-tear group on both 45° of flexion posterior-anterior (2.5 ± 1.3 vs 3.9 ± 1.8 mm; P = .004) and anterior-posterior (3.4 ± 1.1 vs 4.5 ± 0.9 mm; P = .011) radiographs.

Conclusion

Subtotal meniscectomy of the medial meniscus performed during arthroscopic examination with MOWHTO was associated with decreased JSW at midterm follow-up. Efforts should be made to preserve the medial meniscus as much as possible during MOWHTO.

Ipsilateral chondral lesions worsen the long-term prognosis following arthroscopic partial medial meniscectomy

PURPOSE

The effect of knee cartilage defects that are detected during partial meniscectomy remains controversial in terms of the long-term prognosis on knee function. This study aimed to investigate the effect of concurrent medial compartment focal cartilage lesions on the long-term prognosis of knee function in patients who underwent arthroscopic partial medial meniscectomy for traumatic medial meniscal tears.

METHODS

This retrospective study analyzed 46 patients who underwent arthroscopic partial medial meniscectomy between 1991 and 2008 by a single surgeon. Twenty-one patients who underwent arthroscopic partial medial meniscectomy due to traumatic meniscal tear had focal chondral lesions only at the medial compartment, and these patients were assigned to group A. Twenty-five patients who had no cartilage lesions in any compartments were assigned to group B. The age, sex, body mass index (BMI), follow-up time, age at the time of surgery, clinical and radiological scores, and perioperative arthroscopy findings were analyzed.

RESULTS

The mean follow-up time was 20 ± 3.7 years. No significant difference was found in the demographic data, and the average age of the patients at the time of operation was 35 ± 9.5 years. Both groups had improved Lysholm score at the last follow-up. Although no difference was found between the groups during the preoperative period, group B had a higher Lysholm score at the last follow-up than group A. The mean International Knee Documentation Committee (IKDC) and Knee injury and Osteoarthritis Outcome Score (KOOS) scores at the last follow-up were significantly higher in group B. The mean Kellgren-Lawrence grades in the operated knees of group A were higher than those of group B. In group A, a negative correlation was found between the BMI and postoperative Lysholm (r =  - 0.461, p = 0.03) IKDC (r =  - 0.433, p = 0.05) and KOOS (r =  - 0.565, p = 0.008) scores. In group B, no correlation was found between BMI and any score.

CONCLUSION

Among patients who underwent arthroscopic partial medial meniscectomy with an average follow-up of 20 years, those with concurrent focal cartilage defect in the medial compartment had clinically and radiologically worse outcomes than patients without any cartilage defect. Therefore, orthopedic surgeons should be meticulous before performing any arthroscopic partial medial meniscectomy in case of concurrent cartilage lesion.

LEVEL OF EVIDENCE

Level III.

Knee meniscus regeneration using autogenous injection of uncultured adipose tissue-derived regenerative cells

Introduction

The low healing potential of mature menisci necessitates traditional surgical removal (meniscectomy) to eliminate acute or chronic degenerative tears. However, removal of meniscal tissue is main factor causing osteoarthritis. Adipose tissue-derived regenerative cells (ADRCs), a heterogeneous cell population that includes multipotent adipose-derived stem cells and other progenitor cells, were easily isolated in large amounts from autologous adipose tissue, and same-day processing without culture or expansion was possible. This study investigated the regenerative potential of autologous ADRCs for use in meniscus defects.

Methods

In 10- to 12-week-old male SD rat partial meniscectomy model, an atelocollagen sponge scaffold without or with ADRCs (5.0 × 10⁵ cells) was injected into each meniscus defect. Reconstructed menisci were subjected to histologic, and dynamic mechanical analyses.

Results

After 12 weeks, areas of regenerated meniscal tissue in the atelocollagen sponge scaffold in rats with ADRCs (64.54 ± 0.52%, P < 0.05, n = 10) were larger than in those without injection (57.96 ± 0.45%). ADRCs were shown capable of differentiating chondrocyte-like cells and meniscal tissue components such as type II collagen. Higher elastic moduli and lower fluid permeability of regenerated meniscal tissue demonstrated a favorable structure-function relationship required for native menisci, most likely in association with micron-scale porosity, with the lowest level for tissue integrity possibly reproducible.

Conclusions

This is the first report of meniscus regeneration induced by injection of ADRCs. The results indicate that ADRCs will be useful in future clinical cell-based therapy strategies, including as a cell source for reconstruction of damaged knee menisci.

A review of Risk Factors for Post-traumatic hip and knee osteoarthritis following musculoskeletal injuries other than anterior cruciate ligament rupture

Post-traumatic osteoarthritis (PTOA) is a common form of osteoarthritis that might occur after any joint trauma. Most PTOA publications mainly focus on anterior cruciate ligament (ACL) injuries. However, many other traumatic injuries are associated with PTOA, not only for the knee but also for the hip joint. We aim to identify and summarize the existing literature on the musculoskeletal injuries associated with knee and hip PTOA and their risk factors in determining those with a worse prognosis, excluding ACL injuries. Despite the narrative nature of this review, a systematic search for published studies in the last twenty years regarding the most relevant injuries associated with a higher risk of PTOA and associated risk factors for OA was conducted. This review identified the six more relevant injuries associated with knee or hip PTOA. We describe the incidence, risk factors for the injury and risk factors for PTOA of each. Meniscal injury, proximal tibial fracture, patellar dislocation, acetabular, femoral fractures and hip dislocations are all discussed in this review.

Mapping knowledge structure and research trends of knee osteoarthritis with meniscus in two decades: A bibliometric analysis

BACKGROUND

Knee osteoarthritis (KOA) is a chronic degenerative disease that is closely related to the meniscus. Currently, no bibliometric studies have jointly analyzed KOA and the meniscus. This study aimed to provide a comprehensive analysis of the knowledge structure of KOA and the meniscus across two decades and to identify the emerging research trends from a bibliometric perspective.

METHODS

All articles reporting KOA and the meniscus from 2001 to 2021 were obtained from the Web of Science Core Collection. R software, CiteSpace, VOS Viewer, and Microsoft Excel were used to analyze the publications including the authors, cited authors, journals, cited journals, country of research, institutions, and research focus. These data were used to generate visual knowledge maps of the outputs.

RESULTS

A total of 3,218 articles were retrieved. Guermazi was identified as the author who had contributed the most to the field and Osteoarthritis and Cartilage was identified as the most productive research journal. The United States is the global leader in the field and the center for international cooperation with less international collaboration occurring in Eastern Asia. Boston University was the most prolific institution. According to the data, "articular-cartilage," "meniscectomy," "follow-up," "anterior cruciate ligament," and "cartilage" were identified as research hotspots in the field. "Consequences," "prognostic-factors," and "receptor" were predicted as future hot topics of research.

CONCLUSIONS

This study is the first comprehensive bibliometric study to jointly analyze KOA and the meniscus. Our data enable a better understanding of research trends and identify research hotspots and gaps in knowledge across the field. Our findings provide practical information for researchers to better understand the key research areas and identify the research frontiers and future hot topics.

Prevalence of and factors associated with osteoarthritis and pain in retired Olympians, with comparison to the general population: part 1 – the lower limb

Objectives

This study aims (1) to determine the prevalence of lower limb osteoarthritis (OA) and pain in retired Olympians; (2) to identify factors associated with their occurrence and (3) to compare with a sample of the general population.

Methods

3357 retired Olympians (median 44.7 years) and 1735 general population controls (40.5 years) completed a cross-sectional survey. The survey captured demographics, general health, self-reported physician-diagnosed OA, current joint/region pain and injury history (lasting >1 month). Adjusted OR (aOR) compared retired Olympians with the general population.

Results

The prevalence of (any joint) OA in retired Olympians was 23.2% with the knee most affected (7.4%). Injury was associated with increased odds (aOR, 95% CI) of OA and pain in retired Olympians at the knee (OA=9.40, 6.90 to 12.79; pain=7.32, 5.77 to 9.28), hip (OA=14.30, 8.25 to 24.79; pain=9.76, 6.39 to 14.93) and ankle (OA=9.90, 5.05 to 19.41; pain=5.99, 3.84 to 9.34). Increasing age and obesity were also associated with knee OA and pain. While the odds of OA did not differ between Olympians and the general population, Olympians with prior knee and prior hip injury were more likely than controls with prior injury to experience knee (1.51, 1.03 to 2.21 (Olympians 22.0% vs controls 14.5%)) and hip OA (4.03, 1.10 to 14.85 (Olympians 19.1% vs Controls 11.5%)), respectively.

Conclusions

One in four retired Olympians reported physician-diagnosed OA, with injury associated with knee, hip and ankle OA and pain. Although overall OA odds did not differ, after adjustment for recognised risk factors Olympians were more likely to have knee and hip OA after injury than the general population, suggesting injury is an occupational risk factor for retired Olympians.

Animal models of osteoarthritis

Cite this article: Bone Joint Res 2022;11(8):514–517.

Two Uncommon Complications Related to Suture Knots After Meniscal All-Inside Suture Repair: A Case Report

CASE

A 17-year-old male patient suffered a radial lateral meniscus tear and underwent an arthroscopic all-inside suture repair. After 7 months, the patient experienced catching. Magnetic resonance imaging and computed tomography revealed an intra-articular loose body without calcification, which was removed surgically. The excised specimen was histopathologically confirmed to be a necrotic meniscus fragment with a suture knot. In addition, cartilage damage because of suspected impingement by a residual suture knot was observed. After removing the loose body and knot, the patient's symptoms were relieved, and he returned to sports.

CONCLUSION

Suture knot-related complications should be considered while performing meniscal repairs.

Elderly Runners and Osteoarthritis: A Systematic Review

PURPOSE

The impact of running on the onset of osteoarthritis (OA) is controversial. This study compared the incidence of OA in elderly runners versus nonrunners.

MATERIAL AND METHODS

This systematic review was conducted according to the PRISMA guidelines. PubMed, Google scholar, Embase, and Web of Science databases were accessed in January 2022. All the published clinical studies investigating OA onset in runners versus non-runners were considered. Studies reporting data on OA and participants in other sports were excluded. Only studies investigating patients with a mean age older than 55 years were considered. The methodological quality of the articles was evaluated using the Newcastle-Ottawa Scale (NOS).

RESULTS

Data from 3001 participants and 6674 joints were retrieved. The mean age was 59.4±2.7 years. The mean body mass index was 24.6±2.5 kg/m2. The 5 included articles (963 runners, 2038 nonrunners) did not report significant differences in runners compared with controls.

CONCLUSION

Middle aged runners did not present greater imaging or clinical signs of OA compared with nonrunner controls. Running at elite or recreational level did not increase the rate of OA progression in individuals older than 50 years.

Osteoarthritis in Athletes Versus Nonathletes: A Systematic Review

INTRODUCTION

Joint overload and sport-related injuries may accelerate the development of osteoarthritis (OA). A systematic review of the literature was performed to establish the risk of athletes to develop premature OA compared with nonathletes.

MATERIALS AND METHODS

This systematic review was conducted according to the PRISMA guidelines. PubMed, Google scholar, Embase, and Web of Science databases were accessed in June 2021. All the published clinical studies investigating OA onset in athletes versus nonathletes were considered. Studies reporting data on secondary and/or post-traumatic OA were excluded.

RESULTS

Data from 32 articles (20,288 patients) were retrieved. The mean age was 67.8±10.0 years and the mean body mass index was 25.0±2.5 kg/m2. 74% (6859 patients) of the athletes suffered from premature OA. Of them, 21% were active in soccer, 11% in handball, 11% in ice-hockey, 3% in football, and 0.3% in rugby. 26% of the athletes reported no significant differences in OA progression compared with healthy controls. Of these athletes, 47% were runners, 5% dancers, and 1% triathletes.

CONCLUSION

Certain sports, such as soccer, handball, ice-hockey, and rugby are more likely to be associated with premature knee and hip OA. Conversely, runners and ballet dancers do not evidence significant increase in OA. Moderate and recreational exposure to aerobic sports does not accelerate the development of OA.

The Prevalence of Tibiofemoral Knee Osteoarthritis Following Arthroscopic Partial Meniscectomy Is Variably Reported in General, and Over Time: A Systematic Review With a Minimum of 5-Year Follow-Up

Purpose

Methods

Results

Conclusions

Level of Evidence

Heterogeneity of cartilage damage in Kellgren and Lawrence grade 2 and 3 knees: the MOST study

OBJECTIVE

Eligibility for clinical trials in osteoarthritis (OA) is usually limited to Kellgren-Lawrence (KL) grades 2 and 3 knees. Our aim was to describe the prevalence and severity of cartilage damage in KL 2 and 3 knees by compartment and articular subregion.

DESIGN

The Multicenter Osteoarthritis (MOST) study is a cohort study of individuals with or at risk for knee OA. All baseline MRIs with radiographic disease severity KL2 and 3 were included. Knee MRIs were read for cartilage damage in 14 subregions. We determined the frequencies of no, any and widespread full-thickness cartilage damage by knee compartment, and the prevalence of any cartilage damage in 14 articular subregions.

RESULTS

665 knees from 665 participants were included (mean age 63.8 ± 7.9 years, 66.5% women). 372 knees were KL2 and 293 knees were KL3. There was no cartilage damage in 78 (21.0%) medial tibio-femoral joint (TFJ), 157 (42.2%) lateral TFJ and 62 (16.7%) patello-femoral joint (PFJ) compartments of KL2 knees, and 17 (5.8%), 115 (39.3%) and 35 (12.0%) compartments, respectively, of KL3 knees. There was widespread full-thickness damage in 94 (25.3%) medial TFJ, 36 (9.7%) lateral TFJ and 176 (47.3%) PFJ compartments of KL2 knees, and 217 (74.1%), 70 (23.9%) and 104 (35.5%) compartments, respectively, of KL3 knees. The subregions most likely to have any damage were central medial femur (80.5%), medial patella (69.8%) and central medial tibia (69.9).

CONCLUSIONS

KL2 and KL3 knees vary greatly in cartilage morphology. Heterogeneity in the prevalence, severity and location of cartilage damage in in KL2 and 3 knees should be considered when planning disease modifying trials for knee OA.

Biodegradable polyurethane scaffolds in regenerative medicine: Clinical translation review

Early explorations of tissue engineering and regenerative medicine concepts commonly utilized simple polyesters such as polyglycolide, polylactide, and their copolymers as scaffolds. These biomaterials were deemed clinically acceptable, readily accessible, and provided processability and a generally known biological response. With experience and refinement of approaches, greater control of material properties and integrated bioactivity has received emphasis and a broadened palette of synthetic biomaterials has been employed. Biodegradable polyurethanes (PUs) have emerged as an attractive option for synthetic scaffolds in a variety of tissue applications because of their flexibility in molecular design and ability to fulfill mechanical property objectives, particularly in soft tissue applications. Biodegradable PUs are highly customizable based on their composition and processability to impart tailored mechanical and degradation behavior. Additionally, bioactive agents can be readily incorporated into these scaffolds to drive a desired biological response. Enthusiasm for biodegradable PU scaffolds has soared in recent years, leading to rapid growth in the literature documenting novel PU chemistries, scaffold designs, mechanical properties, and aspects of biocompatibility. Despite the enthusiasm in the field, there are still few examples of biodegradable PU scaffolds that have achieved regulatory approval and routine clinical use. However, there is a growing literature where biodegradable PU scaffolds are being specifically developed for a wide range of pathologies and where relevant pre-clinical models are being employed. The purpose of this review is first to highlight examples of clinically used biodegradable PU scaffolds, and then to summarize the growing body of reports on pre-clinical applications of biodegradable PU scaffolds.

Degenerative Meniscus in Knee Osteoarthritis: From Pathology to Treatment

Knee osteoarthritis is a common degenerative joint disease characterized by chronic knee pain and disability in daily living. The lesion can involve the cartilage as well as the synovium, bone, ligaments, and meniscus, indicating a complicated pathology for knee osteoarthritis. The association with the meniscus has recently attracted much attention. Meniscal tears can initiate and progress knee osteoarthritis, with deleterious effects on the important roles of the meniscus in load distribution, shock absorption, and stability of the knee joint. Degenerative meniscus lesions are commonly observed in elderly people, but they have less impact on the prognosis of osteoarthritis. However, they are often accompanied by meniscal extrusion, which substantially decreases the hoop function of the meniscus and increases the risk of knee osteoarthritis. When surgical treatment is necessary, meniscal tears should be repaired to the greatest extent possible to preserve meniscus function. Long-term studies show better clinical outcomes and less degenerative osteoarthritis changes following meniscal repair than following partial meniscectomy. For meniscal extrusion repair, centralization techniques have been proposed that involve suturing the meniscus-capsule complex to the edge of the tibial plateau. Advancements in orthobiologics, such as platelet-rich plasma or stem cell therapy, have the potential to prevent the initiation or progression of osteoarthritis.

Consequences of Progressive Full-Thickness Focal Chondral Defects Involving the Medial and Lateral Femoral Condyles After Meniscectomy: A Biomechanical Study Using a Goat Model

Background:

Full-thickness chondral defects alter tibiofemoral joint homeostasis and, if left untreated, have the potential to progress to osteoarthritis.

Purpose:

To assess the effects of isolated and dual full-thickness chondral defect size and location on the biomechanical properties of the lateral femoral condyle (LFC) and medial femoral condyle (MFC) during dynamic knee flexion in goat knees without menisci.

Methods:

In 12 goat knees, we created progressively increasing full-thickness circular chondral defects (3-, 5-, and 7.5-mm diameter) in the weightbearing contact area of flexion and extension in the MFC, the LFC, or both. Each knee was fixed into a custom steel frame and attached to a motor with sensors inserted intra-articularly. For each testing condition, the knee was loaded to 100 N and underwent a dynamic range of motion between 90° of flexion and 30° of extension. The following parameters were collected: contact area, contact pressure, contact force, peak area, and peak pressure.

Study Design:

Controlled laboratory study.

Results:

The peak pressure at the defect rim of the MFC at full extension increased by 51.51% from no defect (1.887 MPa) to a 7.5-mm defect (2.859 MPa) (P < .001), and the peak pressure at the defect rim of the LFC at full extension increased by 139.14% from no defect (1.704 MPa) to a 7.5-mm defect (4.075 MPa) (P < .001). The peak pressures for LFC defects at all 3 diameters were significantly greater when compared with dual defects consisting of increasing LFC defect diameter and constant MFC defect diameter (P < .001 for all).

Conclusion:

Extremely large increases in peak pressure were seen at the rim of articular cartilage defects when evaluated under dynamic loading conditions. Isolated LFC defects experienced a greater increase in defect rim stress concentrations when compared with isolated MFC defects for equivalent increases in defect size. Defect size played a significant role independent of location for peak pressures on the MFC and LFC.

Clinical Relevance:

Significant rim-loading effects increase with defect size under dynamic loading and may result in increasingly rapid progression of articular cartilage lesions. Within the context of this goat model, findings suggest that lateral compartment chondral lesions are more likely to progress than medial compartment lesions of equivalent size.

Knee Joint Menisci Are Shock Absorbers: A Biomechanical In-Vitro Study on Porcine Stifle Joints

The aim of this biomechanical in vitro study was to answer the question whether the meniscus acts as a shock absorber in the knee joint or not. The soft tissue of fourteen porcine knee joints was removed, leaving the capsuloligamentous structures intact. The joints were mounted in 45° neutral knee flexion in a previously validated droptower setup. Six joints were exposed to an impact load of 3.54 J, and the resultant loss factor (η) was calculated. Then, the setup was modified to allow sinusoidal loading under dynamic mechanical analysis (DMA) conditions. The remaining eight knee joints were exposed to 10 frequencies ranging from 0.1 to 5 Hz at a static load of 1210 N and a superimposed sinusoidal load of 910 N (2.12 times body weight). Forces (F) and deformation (l) were continuously recorded, and the loss factor (tan δ) was calculated. For both experiments, four meniscus states (intact, medial posterior root avulsion, medial meniscectomy, and total lateral and medial meniscectomy) were investigated. During the droptower experiments, the intact state indicated a loss factor of η = 0.1. Except for the root avulsion state (−15%, p = 0.12), the loss factor decreased (p &lt; 0.046) up to 68% for the total meniscectomy state (p = 0.028) when compared to the intact state. Sinusoidal DMA testing revealed that knees with an intact meniscus had the highest loss factors, ranging from 0.10 to 0.15. Any surgical manipulation lowered the damping ability: Medial meniscectomy resulted in a reduction of 24%, while the resection of both menisci lowered tan δ by 18% compared to the intact state. This biomechanical in vitro study indicates that the shock-absorbing ability of a knee joint is lower when meniscal tissue is resected. In other words, the meniscus contributes to the shock absorption of the knee joint not only during impact loads, but also during sinusoidal loads. The findings may have an impact on the rehabilitation of young, meniscectomized patients who want to return to sports. Consequently, such patients are exposed to critical loads on the articular cartilage, especially when performing sports with recurring impact loads transmitted through the knee joint surfaces.

Failed meniscal repair increases the risk for osteoarthritis and poor knee function at an average of 9 years follow-up

PURPOSE

The purpose of this study was to determine the effect of meniscal repair on OA in the knee joint and patient-related outcomes.

METHODS

Three-hundred and sixteen meniscal repairs performed between 1999 and 2011 were analysed. Patient-related outcome measures were assessed through mailed questionnaires including KOOS, Lysholm score and Tegner activity level. Patients answering the questionnaires were encouraged to perform a radiographic evaluation with Rosenberg views, assessed according to Kellgren-Lawrence (KL) classification. The primary endpoint was to determine the effect of meniscal repair on the development of radiographic OA defined as a KL grade 2 or more.

RESULTS

Mean follow-up time was 9.3 years (SD 3.6), 162 (51%) patients answered the questionnaires, and 86 patients completed the X-ray. The odds ratio for OA with a failed meniscus repair was 5.1 (p = 0.007) adjusted for gender and age at time of follow-up. KOOS showed a clinically important difference in the sport and recreation subscale (p = 0.041).

CONCLUSIONS

There was an increased risk for OA in the affected compartment with a failed meniscus fixation. This supports the fact that the meniscus is an important protector of the cartilage in the knee. The meniscus injury affects the long-term health-related quality of life according to KOOS and in light of this study we recommend repair of a torn meniscus whenever possible.

LEVEL OF EVIDENCE

III.

Precision 3D printed meniscus scaffolds to facilitate hMSCs proliferation and chondrogenic differentiation for tissue regeneration

Background

The poor regenerative capability and structural complexity make the reconstruction of meniscus particularly challenging in clinic. 3D printing of polymer scaffolds holds the promise of precisely constructing complex tissue architecture, however the resultant scaffolds usually lack of sufficient bioactivity to effectively generate new tissue.

Results

Herein, 3D printing-based strategy via the cryo-printing technology was employed to fabricate customized polyurethane (PU) porous scaffolds that mimic native meniscus. In order to enhance scaffold bioactivity for human mesenchymal stem cells (hMSCs) culture, scaffold surface modification through the physical absorption of collagen I and fibronectin (FN) were investigated by cell live/dead staining and cell viability assays. The results indicated that coating with fibronectin outperformed coating with collagen I in promoting multiple-aspect stem cell functions, and fibronectin favors long-term culture required for chondrogenesis on scaffolds. In situ chondrogenic differentiation of hMSCs resulted in a time-dependent upregulation of SOX9 and extracellular matrix (ECM) assessed by qRT-PCR analysis, and enhanced deposition of collagen II and aggrecan confirmed by immunostaining and western blot analysis. Gene expression data also revealed 3D porous scaffolds coupled with surface functionalization greatly facilitated chondrogenesis of hMSCs. In addition, the subcutaneous implantation of 3D porous PU scaffolds on SD rats did not induce local inflammation and integrated well with surrounding tissues, suggesting good in vivo biocompatibility.

Conclusions

Overall, this study presents an approach to fabricate biocompatible meniscus constructs that not only recapitulate the architecture and mechanical property of native meniscus, but also have desired bioactivity for hMSCs culture and cartilage regeneration. The generated 3D meniscus-mimicking scaffolds incorporated with hMSCs offer great promise in tissue engineering strategies for meniscus regeneration.

Graphical Abstract

Anterior Cruciate Ligament Reconstruction versus Nonoperative Treatment: Better Function and Less Secondary Meniscectomies But No Difference in Knee Osteoarthritis-A Meta-Analysis

OBJECTIVES

The impact of anterior cruciate ligament (ACL) reconstruction on knee osteoarthritis (OA) is still unclear. The aim of the current meta-analysis was to compare surgical treatment versus nonoperative management of ACL tears to assess the impact of these approaches on knee OA development at a 5 and 10 years of follow-up.

DESIGN

A meta-analysis was performed after a systematic literature search (May 2021) was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. Both randomized and nonrandomized comparative studies with more than 5 years of follow-up were selected. Influence of the treatment was assessed in terms of knee OA development, subjective and objective clinical results, activity level, and risk of further surgeries. Risk of bias and quality of evidence were assessed following the Cochrane guidelines.

RESULTS

Twelve studies matched the inclusion criteria, for a total of 1,004 patients. Level of evidence was rated low to very low. No difference was documented in terms of knee OA development, Tegner score, subjective International Knee Documentation Committee (IKDC), and Lysholm scores. A significant difference favoring the surgical treatment in comparison with a nonsurgical approach was observed in terms of objective IKDC score (P = 0.03) and risk of secondary meniscectomy (P < 0.0001). The level of evidence was considered very low for subjective IKDC, low for knee OA development, objective IKDC, number of secondary meniscectomies, and Lysholm score, and moderate for post-op Tegner score.

CONCLUSIONS

The meta-analysis did not support an advantage of ACL reconstruction in terms of OA prevention in comparison with a nonoperative treatment. Moreover, no differences were reported for subjective results and activity level at 5 and 10 years of follow-up. On the contrary, patients who underwent surgical treatment of their ACL tear presented important clinical findings in terms of better objective knee function and a lower rate of secondary meniscectomies when compared with conservatively managed patents.Protocol Registration: CRD420191156483 (PROSPERO).

Radiographic and Clinical Evidence for Osteoarthritis at Medium-Term Follow-up after Arthroscopic Partial Medial Meniscectomy

OBJECTIVE

The purpose of this study is to assess if incident radiographic osteoarthritis (OA) is associated with clinical OA symptoms at midterm follow-up after arthroscopic partial medial meniscectomy (APMM).

DESIGN

A total of 44 patients (43% females, mean age 50.1 ± 2.8 years, minimum 5.6-year follow-up) with isolated medial meniscal tears and no-to-mild preoperative radiographic OA underwent APMM. Incident radiographic OA was assessed using the modified Kellgren-Lawrence (K-L) classification. Patients completed the Knee Injury and Osteoarthritis Outcomes Score (KOOS), and subscale thresholds for assessment of a symptomatic knee (KOOS OA criteria) and for Patient non-Acceptable Symptom State (PASS-N) following anterior cruciate ligament reconstruction (ACL-R) were calculated.

RESULTS

Incident medial compartment OA occurred in 50% of patients. Morbidly obese patients (body mass index ≥35 kg/m²) were more likely to demonstrate incident radiographic OA (100% vs. 41%, P = 0.002). Forty-three percent of patients met KOOS OA criteria, while 77% were PASS-N. Females were more likely to meet KOOS OA criteria (73% vs. 21%, P = 0.009). Patients with incident radiographic OA in any compartment were more likely than those without radiographic OA to meet KOOS OA criteria (71% vs. 17%, P = 0.008). Patients with preoperative K-L grade 2 changes in any compartment were more likely to meet KOOS OA criteria than those without K-L grade 2 changes in any compartment (83% vs. 35%, P = 0.037).

CONCLUSIONS

Roughly half of APMM patients will have incident radiographic OA within 6 years of APMM, and this risk increases with obesity. Females and patients with incident radiographic OA are more likely to meet clinical thresholds for OA.

Outcomes of Partial Meniscectomy in Obese Patients: A Systematic Review and Meta-Analysis

OBJECTIVE

Arthroscopic partial meniscectomy (APM) is one of the most commonly performed surgical procedures. However, the indications for APM are controversial and obese patients may have worse outcomes. This study's primary purpose was to investigate differences in outcome after APM associated with elevated body mass index (BMI). Secondary objectives included differences in pathophysiology, surgical complications/failures, or osteoarthritis development.

DESIGN

MEDLINE, EMBASE, and OVID databases were systematically searched for eligible studies reporting on APM outcomes at a minimum of 1 year postoperatively. Studies that did not include BMI categorization were excluded. Meta-analysis was conducted with random-effects modeling where data from at least 2 studies was available.

RESULTS

A total of 16 articles were included. Overweight/obese BMI was associated with worse preoperative Lysholm (mean difference, -6.06 [95% CI, -11.70 to -0.42]) and visual analogue scale pain scores (0.43 [0.07 to 0.79]). Worse postoperative normalized knee-specific patient-reported outcome scores were also associated with obese BMI (-4.57 [-5.33 to -3.81]). There were no significant differences in clinical improvement or osteoarthritis progression among BMI groups. Two studies found higher complication/failure rates, 3 articles associated medial meniscus posterior root tears, and 1 article found differences in gene transcript expression with increased BMI.

CONCLUSIONS

Obesity is associated with worse knee function after APM, and patients with elevated BMI have worse preoperative knee pain and function. However, there is no difference in amount of improvement between elevated and normal BMI patients. Further prospective research is necessary to determine the comparative effectiveness of APM in patients with elevated BMI.

In Vivo Studies of Mesenchymal Stem Cells in the Treatment of Meniscus Injury

This review summarizes the literature of preclinical studies and clinical trials on the use of mesenchymal stem cells (MSCs) to treat meniscus injury and promote its repair and regeneration and provide guidance for future clinical research. Due to the special anatomical features of the meniscus, conservative or surgical treatment can hardly achieve complete physiological and histological repair. As a new method, stem cells promote meniscus regeneration in preclinical research and human preliminary research. We expect that, in the near future, in vivo injection of stem cells to promote meniscus repair can be used as a new treatment model in clinical treatment. The treatment of animal meniscus injury, and the clinical trial of human meniscus injury has begun preliminary exploration. As for the animal experiments, most models of meniscus injury are too simple, which can hardly simulate the complexity of actual meniscal tears, and since the follow-up often lasts for only 4-12 weeks, long-term results could not be observed. Lastly, animal models failed to simulate the actual stress environment faced by the meniscus, so it needs to be further studied if regenerated meniscus has similar anti-stress or anti-twist features. Despite these limitations, repair of the meniscus by MSCs has great potential in clinics. MSCs can differentiate into fibrous chondrocytes, which can possibly repair the meniscus and provide a new strategy for repairing meniscus injury.

Second-Look Arthroscopic Evaluation of Healing Rates After Arthroscopic Repair of Meniscal Tears: A Systematic Review and Meta-analysis

Background:

Evaluation of meniscal healing status after repair is important, as it allows the surgeon to inform patients whether they can increase their activities or return to sports.

Purpose:

To identify the healing rates after arthroscopic repair of meniscal tears via second-look arthroscopic evaluation.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

Searches of PubMed, Embase, Scopus, and the Cochrane databases were conducted to identify relevant studies published before June 1, 2020. Studies were eligible for this meta-analysis if they provided data regarding healing status of the meniscus at second-look arthroscopy. Random-effects meta-analyses were generated to provide pooled meniscal healing estimates. We further performed subgroup analysis to investigate the healing rates of the meniscus under different situations.

Results:

A total of 41 studies with 1908 individuals were included in the study. The pooled analysis showed the complete healing rate was 74% (95% confidence interval [CI], 67%-80%), the partial healing rate was 10% (95% CI, 6%-16%), and the failure rate was 12% (95% CI, 10%-15%) for arthroscopic repair of meniscal tears via second-look arthroscopic evaluation. Sensitivity analysis demonstrated that no individual study affected the overall healing rate by >1%. Subgroup analysis found higher meniscal healing rates in patients with the following characteristics: age <40 years, male, body mass index <26, red-red tear location, tear in posterior horn, vertical tear, outside-in technique, repair concomitant with anterior cruciate ligament reconstruction, weight-restricted rehabilitation, and time interval from meniscal repair to second-look arthroscopy >12 months.

Conclusion:

In this systematic review, the complete healing rate was 74%, the partial healing rate was 10%, and the failure rate was 12% for arthroscopic repair of meniscal tears via second-look arthroscopic evaluation.

Lateral Meniscal Tears in Young Patients: A Comparison of Meniscectomy and Surgical Repair

Background:

Meniscal tears are common in active patients, but treatment trends and surgical outcomes in young patients with lateral meniscal tears are lacking.

Purpose:

To evaluate treatment trends, outcomes, and failure rates in young patients with lateral meniscal tears.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Patients aged ≤25 years treated surgically for isolated lateral meniscal tears from 2001 to 2017 were identified. Treatment trends were compared over time. International Knee Documentation Committee (IKDC) scores and failure rates were compared by treatment modality (meniscectomy vs meniscal repair). Failure was defined as reoperation, symptomatic osteoarthritis, or a severely abnormal IKDC score. Univariate regression analyses were performed to predict failure and IKDC scores based on treatment, type and location of tear, or extent of meniscectomy.

Results:

Included were 217 patients (226 knees) with a mean age of 17.4 years (range, 7-25 years); of these patients, 144 knees (64%) were treated with meniscectomy and 82 knees (36%) with meniscal repair. Treatment with repair increased over time compared with meniscectomy (P < .001). At a minimum 2-year follow-up (mean, 6.1 ± 3.9 years), 107 patients (110 knees) had IKDC scores, and analysis indicated that although scores in both groups improved from pre- to postoperatively (repair: from 69.5 ± 13.3 to 97.4 ± 4.3; meniscectomy: from 75.7 ± 9.0 to 97.3 ± 3.9; P < .001 for both), improvement in IKDC score was greater after repair (27.9 ± 13.9) versus meniscectomy (21.6 ± 9.4) (P = .005). Included in the failure analysis were 184 patients (192 knees) at a mean follow-up of 8.4 ± 4.4 years. The rates of reoperation, symptomatic osteoarthritis, and failure were not significantly different between the meniscectomy and repair groups.

Conclusion:

An increase was seen in the rate of isolated lateral meniscal tear repair in young patients. IKDC score improvement was greater after repair than meniscectomy, although postoperative IKDC scores were similar. Symptomatic arthritis, reoperation, and failure rates were similar between groups; however, there was a trend for increased arthritis symptoms in patients treated with meniscectomy, especially total meniscectomy. Treatment modality, type and location of tear, and amount of meniscus removed were not predictive of final IKDC scores or failure.

The Danger Zone for Iatrogenic Neurovascular Injury in All-Inside Lateral Meniscal Repair in Relation to the Popliteal Tendon: An MRI Study

Background:

Lateral meniscal repair can endanger the nearby neurovascular structure (peroneal nerve or popliteal artery). To our knowledge, there have been no studies to evaluate the danger zone of all-inside meniscal repair through the anteromedial (AM) and anterolateral (AL) portals in relation to the medial and lateral edges of the popliteal tendon (PT).

Purpose:

To establish the risk of neurovascular injury and the danger zone in repairing the lateral meniscus in relation to the medial and lateral edges of the PT.

Study Design:

Descriptive laboratory study.

Methods:

Using axial magnetic resonance imaging (MRI) studies at the level of the lateral meniscus, lines were drawn to simulate a straight, all-inside meniscal repair device, drawn from the AM and AL portals to both the medial and lateral edges of the PT. In cases in which the line passed through the neurovascular structure, a risk of iatrogenic neurovascular injury was deemed, and measurements were made to determine the danger zones of neurovascular injury in relation to the medial or lateral edges of the PT.

Results:

Axial MRI images of 240 adult patients were reviewed retrospectively. Repairing the body of the lateral meniscus through the AM portal had a greater risk of neurovascular injury than repairs made through the AL portal in relation to the medial edge of the PT (P = .006). The danger zone in repairing the lateral meniscus through the AM portal extended 1.82 ± 1.68 mm laterally from the lateral edge of the PT and 3.13 ± 2.45 mm medially from the medial edge of the PT. Through the AL portal, the danger zone extended 2.81 ± 1.94 mm laterally from the lateral edge of the PT and 1.39 ± 1.53 mm medially from the medial edge of the PT.

Conclusion:

Repairing the lateral meniscus through either the AM or the AL portals in relation to the PT can endanger the peroneal nerve or popliteal artery.

Clinical Relevance:

The surgeon can minimize the risk of iatrogenic neurovascular injury in lateral meniscal repair by avoiding using the all-inside meniscal device in the danger zone area as described in this study.

Arthroscopic partial meniscectomy: did it ever work?

Arthroscopic partial meniscectomy (APM) is one the most common orthopedic surgical procedures. The most common indication for APM is a degenerative meniscal tear (DMT). High-quality evidence suggests that APM does not provide meaningful benefits in patients with DMTs and may even be harmful in the longer term. This narrative review focuses on a fundamental question: considering the history and large number of these surgeries, has APM ever actually worked in patients with DMT? A truly effective treatment needs a valid disease model that would biologically and plausibly explain the perceived treatment benefits. In the case of DMT, effectiveness requires a credible framework for the pain-generating process, which should be influenced by APM. Basic research, pathoanatomy, and clinical evidence gives no support to these frameworks. Moreover, treatment of DMT with an APM does not align with the traditional practice of medicine since DMT is not a reliable diagnosis for knee pain and no evidence-based indication exists that would influence patient prognosis from APM. A plausible and robust explanation supported by both basic research and clinical evidence is that DMTs are part of an osteoarthritic disease process and do not contribute to the symptoms independently or in isolation and that symptoms are not treatable with APM. This is further supported by the fact that APM as an intervention is paradoxical because the extent of procedure and severity of disease are both inversely associated with outcome. We argue that arthroscopic treatment of DMT is largely based on a logical fallacy: post hoc ergo propter hoc.

Native joint infections in Iceland 2003-2017: an increase in postarthroscopic infections

Objectives

Nationwide study on the epidemiology, clinical characteristics and outcomes among patients with native joint infection (NJI) in Iceland, 2003–2017.

Methods

All positive synovial fluid culture results in Iceland were identified and medical records reviewed.

Results

A total of 299 NJI (40 children and 259 adults) were diagnosed in Iceland in 2003–2017, with a stable incidence of 6.3 cases/100 000/year, but marked gender difference among adults (33% women vs 67% men, p<0.001). The knee joint was most commonly affected, and Staphylococcus aureus was the most common isolate in both adults and children, followed by various streptococcal species in adults and Kingella kingae in children. NJI was iatrogenic in 34% of adults (88/259) but comprised 45% among 18–65 years and a stable incidence. Incidence of infections following arthroscopic procedures in adults increased significantly compared with the previous decade (9/100 000/year in 1990–2002 vs 25/100 000/year in 2003–2017, p<0.01) with no significant increase seen in risk per procedure. The proportion of postarthroscopic NJI was 0.17% overall but 0.24% for knee arthroscopy. Patients with postarthroscopic infection were more likely to undergo subsequent arthroplasty when compared with other patients with NJI (p=0.008).

Conclusions

The incidence of NJI in Iceland has remained stable. The proportion of iatrogenic infections is high, especially among young adults, with an increase seen in postarthroscopic infections when compared with the previous decade. Although rare, NJI following arthroscopy can be a devastating complication, with significant morbidity and these results, therefore, emphasise the need for firm indications when arthroscopic treatment is considered.

A review of strategies for development of tissue engineered meniscal implants

The meniscus is a key stabilizing tissue of the knee that facilitates proper tracking and movement of the knee joint and absorbs stresses related to physical activity. This review article describes the biology, structure, and functions of the human knee meniscus, common tears and repair approaches, and current research and development approaches using modern methods to fabricate a scaffold or tissue engineered meniscal replacement. Meniscal tears are quite common, often resulting from sports or physical training, though injury can result without specific contact during normal physical activity such as bending or squatting. Meniscal injuries often require surgical intervention to repair, restore basic functionality and relieve pain, and severe damage may warrant reconstruction using allograft transplants or commercial implant devices. Ongoing research is attempting to develop alternative scaffold and tissue engineered devices using modern fabrication techniques including three-dimensional (3D) printing which can fabricate a patient-specific meniscus replacement. An ideal meniscal substitute should have mechanical properties that are close to that of natural human meniscus, and also be easily adapted for surgical procedures and fixation. A better understanding of the organization and structure of the meniscus as well as its potential points of failure will lead to improved design approaches to generate a suitable and functional replacement.

Nonoperative and Operative Soft-Tissue and Cartilage Regeneration and Orthopaedic Biologics of the Knee: An Orthoregeneration Network (ON) Foundation Review

Orthoregeneration is defined as a solution for orthopedic conditions that harnesses the benefits of biology to improve healing, reduce pain, improve function, and optimally, provide an environment for tissue regeneration. Options include: drugs, surgical intervention, scaffolds, biologics as a product of cells, and physical and electro-magnetic stimuli. The goal of regenerative medicine is to enhance the healing of tissue after musculoskeletal injuries as both isolated treatment and adjunct to surgical management, using novel therapies to improve recovery and outcomes. Various orthopaedic biologics (orthobiologics) have been investigated for the treatment of pathology involving the knee, including symptomatic osteoarthritis and chondral injuries, as well as injuries to tendon, meniscus, and ligament, including the anterior cruciate ligament. Promising and established treatment modalities include hyaluronic acid (HA) in liquid or scaffold form; platelet-rich plasma (PRP); bone marrow aspirate (BMA) comprising mesenchymal stromal cells (MSCs), hematopoietic stem cells, endothelial progenitor cells, and growth factors; connective tissue progenitor cells (CTPs) including adipose-derived mesenchymal stem cells (AD-MSCs) and tendon-derived stem cells (TDSCs); matrix cell-based therapy including autologous chondrocytes or allograft; vitamin D; and fibrin clot. Future investigations should standardize solution preparations, because inconsistent results reported may be due to heterogeneity of HA, PRP, BMAC, or MSC preparations and regimens, which may inhibit meaningful comparison between studies to determine the true efficacy and safety for each treatment.

Clinical Outcomes of Meniscus Repair with or without Multiple Intra-Articular Injections of Platelet Rich Plasma after Surgery

Preservation of the meniscal volume is crucial in meniscus repair. The goal of this study was to evaluate the clinical outcome of repeated intra-articular platelet-rich plasma (PRP) injections after arthroscopic repair of a traumatic meniscal tear. We retrospectively reviewed 61 primary meniscal repairs in 61 patients (PRP group: 30; non-PRP: 31) from 2017 to 2018. Patients in the PRP group received repeated intra-articular PRP injections in week 2,4,6 after the primary meniscus repair. Subsequent meniscal repair treatment or meniscectomy, knee arthroplasty, and IKDC changes of less than 11.5 points were defined as healing failures. After following up for at least 24 months, the IKDC score was 75.1 ± 13.6, and the Lysholm score was 80.6 ± 14.9 in the PRP group and 72.6 ± 15.8 (IKDC) and 77.7 ± 17.2 (Lysholm) in the non-PRP group. Healing rates of the PRP and the non-PRP groups were 93.3% (Kaplan-Meier 91.6%) and 87.1% (Kaplan-Meier 84.7%), respectively (log rank test p = 0.874). Our study is the first to use multiple intra-articular PRP injections to facilitate meniscal healing after meniscal repair. Though selection bias may be present in this study, the PRP group had similar functional outcome and healing rate compared to non-PRP group.

All-Inside Arthroscopic Repair For Longitudinal Meniscal Tears: Clinical and Functional Results

Meniscal injuries are a common challenge in orthopaedic surgery. Depending on their location and the patient's age and functional needs, they can be treated either conservatively or surgically. A surgical approach can consist of arthroscopic meniscectomy or meniscal suture. The latter is the treatment of choice in case of lesions involving the red-red or red-white areas of the meniscus, especially for young high-demanding patients. We report here our experience with the repair of longitudinal meniscal tears using the all-inside technique with the Fast-Fix™ 360 Meniscal Repair System (Smith & Nephew Endoscopy, Andover, MA). We retrospectively evaluated 20 consecutive cases of longitudinal meniscal tears. In 4 cases, concomitant ACL rupture was diagnosed and treated alongside the meniscal repair. All patients underwent periodic clinical evaluations. At the latest check-up, their functional outcomes were rated according to the Tegner-Lysholm Knee and KOOS scoring scales. The mean Tegner-Lysholm Knee score was 84.85 (44-100) and the mean KOOS score was 88.58. No failure or major complications were observed. Furthermore, a negative statistical association was observed between age at surgery and the post-operative Tegner-Lysholm Knee score (coef. = -1.01189 [-1.942073,-0.0817063], p = 0.035). This relation, independent of gender, meniscus involved, eventual associated ACL reconstruction, and chondral injury, suggests that functional outcomes worsen with increasing patient age. Our results suggest that the arthroscopic all-inside suture is both safe and effective in cases of longitudinal meniscal tear, considering the good post-operative functionality and low rates of local complications and surgical failures.

Does a Delay in Anterior Cruciate Ligament Reconstruction Increase the Incidence of Secondary Pathology in the Knee? A Systematic Review and Meta-Analysis

OBJECTIVE

Previous systematic reviews looking at timing of anterior cruciate ligament reconstruction (ACLR) examined the functional outcomes and range of motion; however, few have quantified the effect of timing of surgery on secondary pathology. The goal of this study was to analyze the effects of early ACLRs versus delayed ACLR on the incidence of meniscal and chondral lesions.

DATA SOURCES

We searched MEDLINE, EMBASE, and CINAHL on March 20, 2018, for randomized control trials (RCTs) that compared early and delayed ACLR in a skeletally mature population. Two reviewers independently identified trials, extracted trial-level data, performed risk-of-bias assessments using the Cochrane Risk of Bias tool, and evaluated the study methodology using the Detsky scale. A meta-analysis was performed using a random-effects model with the primary outcome being the total number of meniscal and chondral lesions per group.

RESULTS

Of 1887 citations identified from electronic and hand searches, we included 4 unique RCTs (303 patients). We considered early reconstruction as <3 weeks and delayed reconstruction as >4 weeks after injury. There was no evidence of a difference between early and late ACLR regarding the incidence of meniscal [relative risk (RR), 0.98; 95% confidence interval (CI), 0.74-1.29] or chondral lesions (RR, 0.88; 95% CI, 0.59-1.29), postoperative infection, graft rupture, functional outcomes, or range of motion.

CONCLUSIONS

We found no evidence of benefit of early ACLR. Further studies may consider delaying surgery even further (eg, >3 months) to determine whether there are any real benefits to earlier reconstruction.

The 50 Most Cited Articles in Meniscal Injury Research

Background:

Meniscal injuries are among the most common orthopaedic injuries, with a significant volume of published literature.

Purpose:

To perform a comprehensive bibliometric analysis that appropriately evaluates the 50 most cited articles in meniscal research.

Study Design:

Cross-sectional study.

Methods:

We performed a keyword search of the ISI Web of Knowledge database and then pared the results down to the 50 most cited articles using specific inclusion and exclusion criteria. Data extracted included title, first author, citation count, year of publication, topic, journal, article type, country of origin, and level of evidence. Correlation coefficients were calculated between publication date and citation density and between publication date and raw citation count.

Results:

The 50 most cited articles were published from 1975 to 2013. The mean number of citations was 258.24 (range, 163-926; median, 225). The majority of articles were published in The American Journal of Sports Medicine (19%), the Journal of Bone and Joint Surgery (12%), and Arthritis & Rheumatology (14%). Most articles focused on either the anatomy and biomechanics of meniscal injury or on prevention and physical rehabilitation (12 papers each).

Conclusion:

The most popular fields of meniscal research involved anatomy/biomechanics and prevention/rehabilitation, and both are areas that will likely increase the probability of an article’s being highly cited in the future. This study provided a quality selection of the most cited articles on meniscal injury and may provide a foundation for both beginner and senior clinician readers for further discussion and research.

Extrusions do not affect degenerative morphologic changes in lateral meniscus allografts during midterm follow-ups

PURPOSE

To investigate degenerative morphological changes in meniscus allograft after lateral meniscus allograft transplantation (MAT) based on extrusions.

METHODS

Ninety-one patients who underwent lateral MAT were divided into extruded and non-extruded groups. Serial magnetic resonance imaging scans obtained 6 weeks, 1 year, and at the last follow-up (midterm, 3-7 years) post-surgery were evaluated retrospectively. Degenerative morphological changes at each time point in each group were compared using the postoperative meniscal width, thickness, and intrameniscal signal intensity (IMSI) at the anterior horn, mid-body, and posterior horn. The Lysholm scores and meniscal tears based on graft extrusion were also investigated.

RESULTS

The mean age was 33.7 ± 11.1 years (64 men and 27 women). Fifty-three (58%) and 38 knees (42%) were classified into the non-extruded and extruded groups, respectively. The overall meniscal width of the mid-body decreased from 9.6 ± 1.3 to 6.5 ± 1.2 mm (p < 0.01), and IMSI of mid-body was increased from 1.2 ± 0.1 to 1.7 ± 0.1 (p < 0.01) during midterm follow-ups. No significant differences were observed between the meniscal width, thickness, and IMSI at the anterior horn (n.s.), mid-body (n.s.), and posterior horn (n.s.) of the two groups during the midterm follow-ups. The incidence of meniscus tears and Lysholm scores did not differ significantly between the groups during midterm follow-ups.

CONCLUSION

The overall meniscus width of mid-body decreased while the relative IMSI of mid-body increased during midterm follow-ups after lateral MAT. Meniscal allograft extrusions did not influence postoperative changes in meniscus width, thickness, and relative intrameniscal signal intensity.

LEVEL OF EVIDENCE

Level III.

Blood in the joint: effects of hemarthrosis on meniscus health and repair techniques

Injury to the meniscus is common and frequently leads to the development of post-traumatic osteoarthritis (PTOA). Many times meniscus injuries occur coincident with anterior cruciate ligament (ACL) injuries and lead to a bloody joint effusion. Hemarthrosis, or bleeding into the joint, has been implicated in degeneration of joint tissues. The goal of this review paper is to understand the pathophysiology of blood-induced joint damage, the possible effects of blood on meniscus tissue, and the implications for current meniscus repair techniques that involve the introduction of blood-derived products into the joint. In this review, we illustrate the similarities in the pathophysiology of joint damage due to hemophilic arthropathy (HA) and osteoarthritis (OA). Although numerous studies have revealed the harmful effects of blood on cartilage and synovium, there is currently a gap in knowledge regarding the effects of hemarthrosis on meniscus tissue homeostasis, healing, and the development of PTOA following meniscus injury. Given that many meniscus repair techniques utilize blood-derived and marrow-derived products, it is essential to understand the effects of these factors on meniscus tissue and the whole joint organ to develop improved strategies to promote meniscus tissue repair and prevent PTOA development.

Acromial and glenoid morphology in glenohumeral osteoarthritis: a three-dimensional analysis

Background

The purpose of this study was to determine the association between glenohumeral osteoarthritis (GHOA) and three-dimensional acromial and glenoid morphology.

Methods

In this retrospective study, we compared computed tomographic studies of three groups of scapulae: normal healthy, mild GHOA (Samilson-Prieto grade 1), and severe GHOA (Samilson-Prieto grade 3). All scans were segmented to create three-dimensional reconstructions. From these models, critical shoulder angle and acromial offset were measured, as normalized to scapular height. The coronal plane inclination of the glenoid was measured using a glenoid sphere-fit method. Reliability was confirmed via intraclass correlation coefficients > 0.75.

Results

Eighty scapulae were included: 30 normal, 20 mild GHOA, and 30 severe GHOA. There were no differences in acromial offset between the normal group and either the mild-GHOA group or the severe-GHOA group. The severe-GHOA group had a smaller critical shoulder angle than either the normal (30 ± 5° vs. 34 ± 4°, P = .003) or mild-GHOA groups (34 ± 4°, P = .020), but the normal and mild-GHOA groups did not differ (P = .965). The severe-GHOA group had more inferiorly inclined glenoids than either the normal (7 ± 6° vs. 12 ± 5°, P = .002) or mild-GHOA groups (14 ± 5°, P ≤ .001), but the normal and mild-GHOA groups did not differ (P = .281).

Conclusion

Normal and severe-GHOA shoulders differ in critical shoulder angle and glenoid inclination but not acromial offset. The lack of a difference in critical shoulder angle or inferior inclination between mild-GHOA and normal groups calls into question whether inclination and critical shoulder angle differences predate severe GHOA.

Development of MRI-defined Structural Tissue Damage after Anterior Cruciate Ligament Injury over 5 Years: The KANON Study

Background MRI is used to evaluate structural joint changes after anterior cruciate ligament (ACL) injury, but no long-term data are available for comparing different treatment approaches. Purpose To describe structural joint damage with MRI over a 5-year period in the Knee Anterior Cruciate Ligament, Nonsurgical versus Surgical Treatment (KANON) study and to compare frequencies of such tissue damage for a nonsurgical versus a surgical treatment strategy. Materials and Methods In this secondary analysis of a prospective trial (ISRCTN 84752559), 119 participants with an acute ACL injury were evaluated. Participants were enrolled from 2002 through 2006, the 2-year follow-up started in 2008, and the 5-year follow-up started in 2011. A 1.5-T MRI examination was performed at baseline and at 2- and 5-year follow-up. MRI scans were read according to a validated scoring instrument. Kruskal-Wallis tests were used to assess whether the frequencies of structural damage differed between the three as-treated groups. Results Of 119 participants (mean age, 26 years ± 5 [standard deviation]), 91 men were evaluated. At 2- and 5-year follow-up, respectively, 13% (15 of 117) and 13% (15 of 115) of knees showed incident cartilage damage in the medial tibiofemoral joint, 11% (13 of 117) and 17% (20 of 115) of knees showed incident cartilage damage in the lateral tibiofemoral joint, and 4% (five of 117) and 8% (nine of 115) of knees showed incident cartilage damage in the patellofemoral joint. Osteophyte development was seen in 23% (27 of 117) and 29% (33 of 115) of knees in the medial tibiofemoral joint, in 36% (42 of 117) and 43% (49 of 115) of knees in the lateral tibiofemoral joint, and in 35% (41 of 117) and 37% (42 of 115) of knees in the patellofemoral joint. No major differences between the groups were found for incident or worsening cartilage damage, bone marrow lesions, and osteophytes at 2 or 5 years. The rehabilitation-alone group showed less Hoffa-synovitis at 2 (P = .02) and 5 (P = .008) years. Conclusion Young adults with anterior cruciate ligament injury showed no major difference in frequency of structural tissue damage on MRI scans at 2 and 5 years regardless of treatment. However, the rehabilitation-alone group had less inflammation at 2 and 5 years. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Andreisek in this issue.