Modern treatment of meniscal tears

Animal models used in meniscal repair research from ex vivo to in vivo: A systematic review

This systematic review, registered with Prospero, aims to identify an optimal animal model for meniscus repair research, moving from ex vivo experimentation to in vivo studies. Data sources included PubMed, Medline, all Evidence-Based Medicine Reviews, Web of Science, and Embase searched in March 2023. Studies were screened using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Extracted data including animal model, type of experiment, type of tear, surgical techniques, and measured outcomes, were recorded, reviewed, and analyzed by four independent reviewers. The SYstematic Review Centre for Laboratory animal Experimentation (SYRCLE) Rob tool was used for critical appraisal and risk of bias assessment. Out of 11,719 studies, 72 manuscripts were included for data extraction and analysis; 41 ex vivo extra-articular studies, 20 ex vivo intra-articular studies, and only 11 in vivo studies. Six animal models were employed: porcine, bovine, lapine, caprine, canine, and ovine. Longitudinal lesions were the most frequently studied tear pattern and sutures the most common repair technique. Studied outcomes focused mainly on biomechanical assessments and gross observations. This systematic review can guide researchers in their choice of animal model for meniscus repair research; it highlighted the strengths of the porcine, caprine, and bovine models for ex vivo cadaveric studies, while the porcine and caprine models were found to be more suited to in vivo studies due to their similarities with human anatomy. Research teams should familiarize themselves with the advantages and disadvantages of various animal models before initiating protocols to improve standardization in the field.

Pulsed radiofrequency of iPACK (interspace between the popliteal artery and the posterior knee capsule) for pain control following meniscus repair - A case report

Adequate postoperative pain control is an essential factor for the success of rehabilitation programs after meniscus repair (MR). The pulsed radiofrequency of the interspace between the popliteal artery and the posterior knee capsule (PRF-iPACK) is a recently developed method. This study aimed to evaluate the use of PRF-iPACK in patients who underwent MR. We performed PRF-iPACK guided by ultrasonography for patients who underwent MR with aggravated pain. PRF-iPACK was performed following MR four weeks after surgery. The pain was evaluated using the visual analogue scale (VAS), Lysholm score, and the Euroqol-5 Dimension (EQ-5D). In this study, two patients participated. For the results, a week and three months after treatment, the mean VAS score, Lysholm score, and EQ5D improved from 7 to 1 and 0 respectively, and 42 to 86 and 90 respectively, and 0.48 to 0.82 and 0.92 respectively. We concluded that PRF-iPACK is an adequate and safe procedure for managing postoperative pain after MR. It may enhance the postoperative rehabilitation program.

Increased Age, Operative Time, American Society of Anesthesiologists Classification, Functional Dependency, and Comorbidity Burden Are Risk Factors for Adverse Events After Meniscectomy and Meniscus Repair: 10-Year Analysis of 64,223 Patients

PURPOSE

To use the National Surgical Quality Improvement Program (NSQIP) database to identify risk factors for 30-day adverse events and hospital readmission following isolated and unilateral meniscectomy or meniscus repair.

METHODS

A retrospective review of the NSQIP database from the years 2012 to 2021 identified all patients undergoing isolated, unilateral meniscectomy or meniscus repair. Multivariable analyses were performed for each procedure to identify patient characteristics associated with any adverse event (AAE) or unplanned hospital readmission within 30 days of surgery.

RESULTS

From 2012 to 2021, 59,450 (93%) patients underwent meniscectomy, and 4,773 (7%) patients underwent meniscus repair. Overall adverse event rate was 0.95% after meniscectomy and 1.40% after repair. Risk factors for AAE after meniscectomy included increased age (odds ratio [OR] = 1.010; P = .009), increased operative time (OR = 1.003; P = 0.011), American Society of Anesthesiologists (ASA) class IV (OR = 2.048; P = .045), functional dependency (OR = 3.527; P = .001), and current smoking (OR = 1.308; P = .018). Risk factors for AAE after meniscus repair included age (OR = 1.024; P = .016), operative time (OR = 1.004; P = .038), and bleeding disorders (OR = 7.000; P = .014). ASA class III increased risk of hospital readmission after both procedures (OR = 1.906; P = .008; OR = 4.101; P = .038), and medical comorbidities of heart failure (OR = 3.924; P = .016), hypertension (OR = 1.412; P = .011), and chronic obstructive pulmonary disease (OR = 2.350; P < .001) increased readmission risk after meniscectomy only.

CONCLUSIONS

Per analysis of the American College of Surgeons (ACS)-NSQIP database, surgical treatment of meniscal tears in the knee has been performed frequently over the past 10 years, with meniscectomies comprising over 90% of cases. Increased age and operative time were associated with a modest risk of adverse events after both meniscectomy and meniscus repair. Increased comorbidity burden, evidenced by ASA class, dependent functional status, current smoking, and systemic medical conditions, such as heart failure, hypertension, chronic obstructive pulmonary disease, and bleeding disorders, greatly increased rates of unfavorable outcomes within 30 days of meniscus surgery.

LEVEL OF EVIDENCE

Level III, retrospective prognostic comparative investigation.

Physical Therapist Interventions Versus or Combined With Surgical Treatment in Nontraumatic Degenerative Meniscal Pathology: A Systematic Review and Network Meta-Analysis

OBJECTIVE

This study aimed to synthesize the evidence from randomized clinical trials in people with nontraumatic degenerative meniscal pathology by comparing physical therapist interventions versus or combined with arthroscopic partial meniscectomy (APM).

METHODS

Seven electronic databases were searched. Methodological quality was evaluated using the Physiotherapy Evidence Database scale. Data synthesis was performed with random-effects network meta-analysis, and results were summarized using the standardized mean differences.

RESULTS

From 2103 studies, 10 randomized clinical trials comprising 1411 individuals were included. Ninety percent of the selected randomized clinical trials were classified as good quality according to the Physiotherapy Evidence Database scale. All interventions (physical therapist interventions, APM, and APM plus physical therapist interventions) showed reduced pain and physical impairments at 3-month follow-up. However, when a physical therapist intervention was included, greater reductions in pain at rest (APM vs physical therapist interventions: 0.73 [95% CI = 0.20 to 1.26]; APM vs APM plus physical therapist interventions: 0.59 [95% CI = 0.15 to 1.03]) and greater increases in the strength of knee extensor muscles (APM vs physical therapist interventions: 0.44 [95% CI = 0.07 to 0.80]; APM vs APM plus physical therapist interventions: 0.73 [95% CI = 0.29 to 1.16]) were observed at 3 months. By contrast, no differences were found between treatments beyond 3 months.

CONCLUSION

Physical therapist interventions based on exercise programs demonstrate superior short-term outcomes in pain reduction and knee extensor strength compared to surgical treatment.

IMPACT

For nontraumatic degenerative meniscal pathology, conservative treatment utilizing a physical therapist intervention approach should be prioritized as the first choice over surgical treatment. It offers comparable or superior short-term pain reduction and strength improvements, with a lower risk of side effects. In cases where surgery is deemed necessary, including postsurgical, physical therapist interventions are highly recommended to enhance muscle strength and alleviate pain.

The Impact of Bone Marrow Venting Augmentation on Knee Functions in the Repair of Vertical/Longitudinal Meniscus Tears: A Triple Comparison

Objective

Preserving and restoring meniscus function is crucial for maintaining knee biomechanics and overall functionality. To enhance the healing process after meniscus repair, various biological techniques have been introduced. In this study, three treatment approaches examined were bone marrow venting with stem cells (BMVP), anterior cruciate ligament reconstruction (ACLR) with meniscus repair, and isolated meniscus repair.

Materials and Methods

From 2015 to 2019, we retrospectively analyzed data from 83 patients who presented with complaints of knee pain or pain in addition to instability, were diagnosed with vertical/longitudinal meniscus tears, and underwent arthroscopic repair (30 with isolated repair, 28 with ACLR repair, and 25 with BMVP) at our University Hospital. Among the 28 patients with anterior cruciate ligament rupture, pain and instability were the predominant complaints, whereas 55 patients with meniscus tear primarily complained pain. Clinical and functional conditions were assessed using Lysholm, WOMAC, IKDC, and VAS scores before and 18 months after surgery. Surgical success was evaluated based on Barrett's criteria. Causes of failure were analyzed considering demographic data, smoking status, injury time, tear location, shape, zone, and suture type and number.

Results

Of the participants, 58 were male, 25 were female, 61 had medial meniscus lesions, and 22 had lateral meniscus lesions. The tear types included 51 simple longitudinal tears, 18 bucket handle tears, and 14 complex tears. A significant improvement was observed in the postoperative 18 month Lysholm, WOMAC, and IKDC values in all three groups (p: 0.001). At the 18 month mark, clinical and functional outcomes were comparable between BMVP and ACLR repair groups (Lysholm p: 0.951, WOMAC p: 0.241, IKDC p: 0.984). Both of these procedures yielded better results compared to isolated meniscus repair (Lysholm p: 0.001, WOMAC p: 0.027, IKDC p: 0.001).

Conclusion

The superior clinical and functional outcomes observed after meniscus repair with BMVP and ACLR, compared to isolated meniscus repair, indicate positive effects of bone marrow stem cells, blood components, and tissue healing factors on meniscus repair and knee function.

Factors associated with medial meniscal extrusion in non-osteoarthritic knees with medial meniscus tears: A cross-sectional study

BACKGROUND

Medial meniscal extrusion (MME) plays an important role in the progression of knee osteoarthritis. Exploring the factors associated with MME in non-osteoarthritic knees may assist in the prevention of osteoarthritis.

OBJECTIVE

To identify the factors associated with pathologic MME in non-osteoarthritic knees with medial meniscus tears (MMTs).

DESIGN

A cross-sectional study.

PARTICIPANTS

One hundred fifty patients with non-osteoarthritic knees who underwent arthroscopic surgery for MMT. Patients were divided into a pathologic MME group (n = 54) and a control group (n = 96) based on whether a pathologic MME was present on magnetic resonance (MR) images.

SETTING

Tertiary medical institution.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

The MME distance was measured on a coronal MR image obtained at the midpoint of the medial femoral condyle. An MME distance ≥3 mm was considered to indicate pathologic MME. Demographic and clinical data were collected as variables. Multivariable logistic regression analysis was performed to identify factors associated with pathologic MME.

RESULTS

After multivariable adjustment, body mass index (BMI) and the type of MMT were associated significantly with pathologic MME in the multivariable logistic regression model. Each unit higher in BMI was associated with a 13% higher risk of pathologic MME (odds ratio [OR] 1.13, 95% confidence interval [CI] 1.01-1.28, p = .04). The odds of pathologic MME were approximately four times and three times higher for radial tears (OR 4.34, 95% CI 1.25-15.03, p = .02) and complex tears (OR 3.07, 95% CI 1.17-8.05, p = .02) than for horizontal and longitudinal tears.

CONCLUSIONS

BMI and the type of MMT were independent factors associated with pathologic MME in non-osteoarthritic knees with MMT. A higher BMI, radial tears, and complex tears were predisposed to pathologic MME.

[Research progress of magnesium and magnesium alloy implants in sports medicine]

Objective

To review the research progress of magnesium and magnesium alloy implants in the repair and reconstruction of sports injury.

Methods

Relevant literature of magnesium and magnesium alloys for sports injury repair and reconstruction was extensively reviewed. The characteristics of magnesium and its alloys and their applications in the repair and reconstruction of sports injuries across various anatomical sites were thoroughly discussed and summarized.

Results

Magnesium and magnesium alloys have advantages in mechanical properties, biosafety, and promoting tendon-bone interface healing. Many preclinical studies on magnesium and magnesium alloy implants for repairing and reconstructing sports injuries have yielded promising results. However, successful clinical translation still requires addressing issues related to mechanical strength and degradation behavior, where alloying and surface treatments offer feasible solutions.

Conclusion

The clinical translation of magnesium and magnesium alloy implants for repairing and reconstructing sports injuries holds promise. Subsequent efforts should focus on optimizing the mechanical strength and degradation behavior of magnesium and magnesium alloy implants. Conducting larger-scale biocompatibility testing and developing novel magnesium-containing implants represent new directions for future research.

Comparison of Partial Meniscectomy With Meniscal Repair With Respect to Functional Outcome

Introduction Meniscus tear is a commonly encountered sports-related injury requiring surgical intervention due to knee mobility dysfunction and discomfort. Previously, it has been thought that these are non-functional vestigial structures and they used to be excised commonly. Recent studies have shown that meniscal repair gives superior results when compared with partial meniscectomy. Methods This quasi-experimental study was conducted at the Orthopedics Department, Khyber Teaching Hospital, Peshawar, Pakistan. A total of 92 patients of both genders with meniscal injuries were included. Forty-six of them underwent meniscal repair (Group A), and 46 underwent partial meniscectomy (Group B). Functional outcome was noted after 12 weeks and recorded. Results The age range was from 18 to 50 years with a mean of 28.630±6.64 years in Group A and 29.630±8.12 years in Group B. Functional outcome was excellent in 44 (95.7%) patients who underwent meniscal repair as compared to 23 (50%) patients who underwent partial meniscectomy (P= 0.000). Conclusion It is concluded that meniscal repair should be pursued over partial meniscectomy when surgically treating meniscal tears.

The Association between the Extent of the Osteoarthritic Meniscus Degeneration and Cigarette Smoking-A Pilot Study

Background and Objectives: The negative effects of smoking on the musculoskeletal system were presented by many authors, although the relationship between smoking and osteoarthritis remains unclear. The aim of this paper was to investigate the negative effects of smoking on meniscal tissue in osteoarthritic knees by microscopic examination, by adapting the Bonar scoring system and its modifications. Materials and Methods: The study involved 34 patients with varus knees, from whom 65 samples of knee menisci were obtained. The mean age in the studied group was 65.385 years. The smoking status of the patients concluded that there were 13 smokers and 21 nonsmokers. Results: Among smokers, the mean classical Bonar score was 8.42 and the mean modified Bonar score was 6.65, while nonsmokers were characterized by scores of 8.51 and 7.35, respectively. There was a statistically significant negative correlation between the number of cigarettes and the collagen in the medial meniscus (p = 0.0197). Moreover, in the medial meniscus, the modified Bonar score correlated negatively with the number of cigarettes (p = 0.0180). Similarly, such a correlation was observed between the number of cigarettes and the modified Bonar score in the lateral meniscus (p = 0.04571). Furthermore, no correlation was identified between the number of cigarettes and the classical Bonar score in the lateral meniscus. There was a statistically significant difference in the collagen variable value between the smokers and nonsmokers groups (p = 0.04525). Conclusions: The microscopic investigation showed no differences in the menisci of smokers and nonsmokers, except for the collagen, which was more organized in smokers. Moreover, the modified Bonar score was correlated negatively with the number of cigarettes, which supports the role of neovascularization in meniscus pathology under the influence of tobacco smoking.

Long-term follow-up of inpatients with meniscus tears who received integrative Korean medicine treatment: A retrospective analysis and follow-up survey

Evidence regarding the use of Korean medicine (KM) for the conservative treatment of meniscus tears remains lacking. We aimed to evaluate clinical effectiveness and long-term follow-up outcomes in patients undergoing integrative KM treatment for meniscus tears. We analyzed the electronic medical records (EMRs) of 86 patients with meniscus tears and administered a follow-up survey. Patients treated at 1 of 4 KM hospitals between June 1, 2015, and June 30, 2020, were reviewed. KM treatment comprised herbal medicine, acupuncture, pharmacopuncture, bee venom pharmacopuncture, Chuna therapy, and KM physiotherapy. The primary outcome was the numeric rating scale (NRS) score for knee pain; secondary outcomes were the Western Ontario and McMaster Universities Arthritis Index (WOMAC), EuroQol 5-dimension (EQ-5D) score, range of motion, and patient global impression of change. The NRS for knee pain was reduced by an average of 2.49 (95% confidence interval [CI]: 2.03-2.95) at discharge and 1.97 (95% CI: 2.03-2.95) at follow-up. The WOMAC decreased by an average of 15.52 (95% CI: 10.14-20.89) during hospital stay and 30.72 (95% CI: 24.58-36.87) at follow-up. The EQ-5D score increased by an average of 0.06 (95% CI: -0.14 to 0.02) at discharge and 0.19 (95% CI: -0.29 to -0.09) at follow up. KM treatment effectively reduced knee pain, improved knee joint function, and enhanced the quality of life in patients with a meniscus tear for a relatively long period after treatment.

Comparative, Controlled, Retrospective Study of Patient-Reported Outcomes After Meniscectomy With Adjunctive Use of Platelet-Rich Plasma or Amniotic Umbilical Cord Tissue

Background: Meniscal tears are one of the most frequent injuries to the knee, with an estimated incidence of 222 per 100,000 individuals aged 18 to 55 years based on magnetic resonance imaging. Poor outcomes following meniscal surgical interventions are common and have led many surgeons to use biologic augmentation strategies to enhance the healing. Methods: We conducted a single-center, retrospective, observational study of patients who underwent arthroscopic meniscectomy with and without adjunctive platelet-rich plasma (PRP) or the particulate form of amniotic umbilical cord (AMUC) tissue. We evaluated patient-reported outcomes on the visual analog scale for pain, International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form, Lysholm Knee Scoring Scale, 12-Item Short Form Survey, and Knee Injury and Osteoarthritis Outcome Score (KOOS) during a 1-year postoperative period. Complications and follow-up procedures were also evaluated. Results: We evaluated 113 patients who underwent meniscectomies from November 2010 to March 2017. Pain severity was significantly decreased only in the AMUC group at 6 months (P=0.0143). Patients in the AMUC group demonstrated significant improvement in functional recovery based on the IKDC and the KOOS subscales of pain, symptoms, activities of daily living, and sport and recreation function at 6 months. Patients in the PRP group had a significant benefit in the KOOS subscales of pain, symptoms, sport and recreation function, and knee-related quality of life at 3 months. Improvement in the control group was less substantial. Patients in the PRP group had more complications and follow-up procedures (30.0%) than patients in the AMUC group (8.3%). Conclusion: In our study population, arthroscopic meniscectomy with adjunctive use of AMUC tissue improved patient-reported outcomes and reduced the reoperation rate compared to conventional technique or adjunctive use of PRP.

Meniscectomy is associated with a higher rate of osteoarthritis compared to meniscal repair following acute tears: a meta-analysis

PURPOSE

Meniscal tears are common and may impair knee function and biomechanics. This meta-analysis compared meniscal repair versus resection in patients with symptomatic meniscal tears in terms of patient-reported outcomes measures (PROMs), joint width, surgical failure, and rate of progression to osteoarthritis (OA) at conventional radiography.

METHODS

This study was conducted according to the 2020 PRISMA statement. In August 2023, the following databases were accessed: PubMed, Web of Science, Google Scholar, and Embase. Two reviewers independently performed the analysis and a methodological quality assessment of the included studies. All the clinical investigations which compared repair versus resection of meniscal tears were accessed.

RESULTS

Data from 20 studies (31,783 patients) were collected. The mean BMI was 28.28 ± 3.2 kg/m2, and the mean age was 37.6 ± 14.0 years. The mean time elapsed from injury to surgery was 12.1 ± 10.2 months and the mean medial joint width was 4.9 ± 0.8 mm. Between studies comparability at baseline was found in age, women, BMI, time from injury to surgery and length of the follow-up, PROMs, medial joint width, and stage of OA. The resection group demonstrated a greater Lysholm score (P = 0.02). No difference was found in the International Knee Documentation Committee (P = 0.2). Nine studies reported data on the rate of failures at a mean of 63.00 ± 24.7 months. No difference was found between the two groups in terms of persistent meniscal symptoms (P = 0.8). Six studies reported data on the rate of progression to total knee arthroplasty at a mean of 48.0 ± 14.7 months follow-up. The repair group evidenced a lower rate of progression to knee arthroplasty (P = 0.0001). Six studies reported data on the rate of advanced knee OA at a mean of 48.0 ± 14.7 months of follow-up. The repair group evidenced a lower rate of advanced knee OA (P = 0.0001). No difference was found in the mean joint space width (P = 0.09).

CONCLUSION

Meniscal repair is associated with a lower progression to knee osteoarthritis at approximately six years of follow-up compared to partial meniscectomy. No difference in PROMs, medial joint width, and failures were evidenced.

LEVEL OF EVIDENCE

Level III, meta-analysis.

In-Office Needle Arthroscopy with Meniscal Repair for Meniscal Lesions of the Knee

Meniscal injuries are a common cause of knee pain and are often an indication for knee arthroscopy, the most common orthopedic surgical procedure in the United States. In-office needle arthroscopy (IONA) is a described technique with the ability to diagnose and treat meniscal injuries in the office. IONA allows for diagnosis and treatment at a significantly deceased cost, with both quicker patient recovery, and improved patient satisfaction. The purpose of this technical report is to describe the technique for performing in-office needle arthroscopy for meniscal injuries of the knee, including the technique for obtaining adequate local anesthesia, proper indications, adequate visualization, and the advantages of performing these procedures in the office rather than the operating room.

Health-economic evaluation of meniscus tear treatments: a systematic review

PURPOSE

To evaluate the overall evidence of published health-economic evaluation studies on meniscus tear treatment.

METHODS

Our systematic review focuses on health-economic evaluation studies of meniscus tear treatment interventions found in PubMed and Embase databases. A qualitative, descriptive approach was used to analyze the studies' results and systematically report them following PRISMA guidelines. The health-economic evaluation method for each included study was categorized following one of the four approaches: partial economic evaluation (PEE), cost-effectiveness analysis (CEA), cost-benefit analysis (CBA), or cost-utility analysis (CUA). The quality of each included study was assessed using the Consensus on Health Economic Criteria (CHEC) list. Comparisons of input variables and outcomes were made, if applicable.

RESULTS

Sixteen studies were included; of these, six studies performed PEE, seven studies CUA, two studies CEA, and one study combined CBA, CUA, and CEA. The following economic comparisons were analyzed and showed the respective comparative outcomes: (1) meniscus repair was more cost-effective than arthroscopic partial meniscectomy (meniscectomy) for reparable meniscus tear; (2) non-operative treatment or physical therapy was less costly than meniscectomy for degenerative meniscus tear; (3) physical therapy with delayed meniscectomy was more cost-effective than early meniscectomy for meniscus tear with knee osteoarthritis; (4) meniscectomy without physical therapy was less costly than meniscectomy with physical therapy; (5) meniscectomy was more cost-effective than either meniscus allograft transplantation or meniscus scaffold procedure; (6) the conventional arthroscopic instrument cost was lower than laser-assisted arthroscopy in meniscectomy procedures.

CONCLUSION

Results from this review suggest that meniscus repair is the most cost-effective intervention for reparable meniscus tears. Physical therapy followed by delayed meniscectomy is the most cost-effective intervention for degenerative meniscus tears. Meniscus scaffold should be avoided, especially when implemented on a large scale.

LEVEL OF EVIDENCE

Systematic review of level IV studies.

Strength-Based Rehabilitation on Clinical Outcomes in Patients Postpartial Meniscectomy: A Systematic Review and Meta-analysis

OBJECTIVE

The aim of the study is to determine the effect of strength-based rehabilitation programs on patients who underwent partial meniscectomy procedures.

DESIGN

Three databases MEDLINE, PubMed, and Embase were searched from inception to May 9, 2022. Data on functional outcomes such as quadriceps and hamstring strengths, as well as patient-reported outcomes such as Knee Osteoarthritis and Outcome Score and visual analog scale were recorded.

RESULTS

A total of nine studies comprising 417 patients were included in this review. There were no significant differences in quadriceps or hamstring strength measures between preinterventation and postintervention for both groups. Knee Osteoarthritis and Outcome Scores significantly increased from preintervention and postintervention in both control and exercise groups. Visual analog scale scores changed from 5.0 to 1.4 cm in the exercise arm and 3.1 to 1.9 cm in the control arm.

CONCLUSIONS

Strength-based exercise programs for patients postpartial meniscectomy did not result in significantly different improvements in quadriceps or hamstring strength compared with control programs. However, strength-based exercise programs resulted in significantly higher Knee Osteoarthritis and Outcome Scores and a greater decrease in visual analog scale scores. Further studies, specifically well-designed systematic randomized controlled trials, are necessary to elucidate the specifics behind what type of exercises to use in addition to load progression and frequency of training.

INFLUENCE OF CRYOTHERAPY WITH PULSE COMPRESSION ON THE FUNCTIONAL CONDITION OF THE KNEE JOINT AFTER PARTIAL MENISCECTOMY

OBJECTIVE

The aim: To study the effect of cryotherapy with adjustable pulse compression in patients after arthroscopic partial meniscectomy on the functional state of the knee joint in the early period of rehabilitation.

PATIENTS AND METHODS

Materials and methods: A total of 63 patients took part in the research: the experimental group included 32 patients (23 men and 9 women), and the control group - 31 patients (21 men and 10 women). In order to determine the effect on the functional state of the knee joint after arthroscopic partial meniscectomy in the experimental group, cryotherapy with adjustable pulse compression was used with the help of «GIOCO CRYO - 2» system; ice bags were used in the control group. In the research process, the following methods were used: visual analogue point scale, sonography, goniometry and myotonometry.

RESULTS

Results: It was found that in the experimental group, under the influence of cryotherapy with adjustable pulse compression, there was a progressive decrease in the intensity of the pain syndrome, the accumulation of reactive synovial fluid, a dynamic increase in the amplitude of movements of the operated joint, and an improvement in the muscle tone of the quadriceps femoris (p<0,05-0,001).

CONCLUSION

Conclusions: Thus, cryotherapy with adjustable pulse compression has shown a positive effect on the functional state of the knee joint in the early period of patients' rehabilitation, after partial meniscectomy and can be recommended for use in clinical practice.

Smoking Has No Influence on Outcomes after Repair of the Medial Meniscus in the Hypo and Avascular Zones-A Pilot Study

Complete loss of the meniscus inevitably leads to knee joint degeneration. Smoking is an important factor predicting poor outcome in orthopedics; however, data about its role in meniscus surgery are inconclusive. Smoking could be an important negative factor in isolated meniscus repair. The aim of this paper was to determine the influence of smoking on functional outcomes after isolated all-inside medial meniscus repair. This study included 50 consecutive patients with isolated, traumatic tear of the medial meniscus who underwent knee joint arthroscopy between 2016 and 2019. All-inside arthroscopic repair of the medial meniscus was performed in each case. All patients followed a uniform, postoperative rehabilitation protocol for 8 weeks. The follow-up examination was based on the functional scores at 3 and 6 months postoperatively. According to smoking status there were 17 smokers and 33 non-smokers. The mean number of cigarettes smoked per day was 11, for a mean of 7.4 years, and the mean pack-years index value was 4.9. There was no correlation between smoking years, number of cigarettes smoked per day, pack-years index, and functional outcomes. The arthroscopic inspection of the knee joints revealed cartilage lesions (≤IIº) in eight subjects, suggesting the secondary pathology to the meniscus tear. In this study, we found no evidence of an association between smoking indices and functional outcomes after all-inside repair of chronic medial meniscus tear. The nature of the chronic meniscal tear could be smoking-resistant owing to the poor blood supply to the sites in which these specific lesions occur.

The Efficacy of the Mulligan Concept to Treat Meniscal Pathology: A Systematic Review

Background

Meniscal pathologies are common knee injuries and arthroscopic surgery is the current accepted gold standard for treatment. However, there is evidence to support the use of the Mulligan Concept (MC) Mobilization with Movement (MWM) for meniscal pathologies including the 'Squeeze' technique, tibial internal rotation (IR), and tibial external rotation (ER).

Hypothesis/Purpose

The purpose of this systematic review was to critically appraise the literature to investigate the effectiveness of MC MWMs for meniscal lesions on patient reported pain, function, and multi-dimensional health status in patients with clinically diagnosed meniscal pathologies.

Study Design

Systematic Review.

Methods

A literature search was completed across multiple databases using combinations of the words "knee, function, mobilization with movement, MWM, mulligan concept, MC, meniscal pathology, meniscal derangement, and meniscal tear." Studies written within the prior 10 years that examined MC MWM techniques to treat knee meniscal injury were included. Articles that met the inclusion criteria (used MC MWM 'Squeeze' technique, tibial IR, or tibial ER for treatment of clinically diagnosed meniscal pathologies; Patient reported outcome [PRO] measures had to be used in the assessment of knee pain or function) were analyzed for quality. Randomized control trials were analyzed using the PEDro scale and the Downs & Black (D&B) checklist, case series were analyzed using the Joanna Briggs Institute (JBI) checklist, and case reports were analyzed using the CARES checklist.

Results

Six articles met the inclusion criteria and were included in this review, two randomized controlled studies, two case series, and two case reports consisting of 72 subjects. All six papers included reports of improvements in pain and function that were either statistically significant or met the minimal clinically important difference (MCID). Five studies reported the Disablement in the Physically Active (DPA) scale that also demonstrated statistically significant differences or met the MCID. The MC MWM 'Squeeze' technique, tibial IR, or tibial ER demonstrated the ability to reduce pain, improve function, and improve patient perceived disability following treatment of a clinically diagnosed meniscal pathology. These studies demonstrated short term results lasting from one week to 21 weeks.

Conclusion

Treatment interventions incorporating MC MWM techniques demonstrated reduction of pain and improvement in function in the short term in patients with clinically diagnosed meniscal pathologies.

Level of Evidence

2a.

Selective Unique Signs of Meniscus Tears as Visualized by Magnetic Resonance Imaging

The meniscus is an organized collection of fibrocartilaginous tissue that is located between the femoral condyles and the tibial plateau of the knee which primarily assists with load transmission. The complex composition of articulating soft-tissue structures in the knee causes the menisci to become a common source of injury, especially in the realm of athletic trauma. Magnetic resonance imaging (MRI) has become the imaging modality of choice for evaluating patients with suspected meniscal pathology because of its numerous advantages over plain radiographs. Most forms of meniscal tears have classic MRI findings and are used in correlation with physical examination findings to confirm or rule out a diagnosis. These imaging findings are referred to as signs and have been well studied, and the associated eponyms for each sign are well published throughout the literature. This article will review and describe a unique selection of meniscal pathology as visualized by MRI that is more commonly published in musculoskeletal radiology literature when compared with orthopedics and sports medicine literature.

Formulation and evaluation of a bioink composed of alginate, gelatin, and nanocellulose for meniscal tissue engineering

1The necessity to preserve meniscal function prompts the research and development of novel treatment options, like three-dimensional (3D) bioprinting. However, bioinks for meniscal 3D bioprinting have not been extensively explored. Therefore, in this study, a bioink composed of alginate, gelatin, and carboxymethylated cellulose nanocrystal (CCNC) was formulated and evaluated. Firstly, bioinks with varying concentrations of the aforementioned components were subjected to rheological analysis (amplitude sweep test, temperature sweep test, and rotation). The optimal bioink formulation of 4.0% gelatin, 0.75% alginate, and 1.4% CCNC dissolved in 4.6% D-mannitol was further used for printing accuracy analysis, followed by 3D bioprinting with normal human knee articular chondrocytes (NHAC-kn). The encapsulated cells' viability was > 98%, and collagen II expression was stimulated by the bioink. The formulated bioink is printable, stable under cell culture conditions, biocompatible, and able to maintain the native phenotype of chondrocytes. Aside from meniscal tissue bioprinting, it is believed that this bioink could serve as a basis for the development of bioinks for various tissues.

Sensitivity Enhancement Using Chirp Transmission for an Ultrasound Arthroscopic Probe

Meniscal tear in the knee joint is a highly common injury that can require an ablation. However, the success rate of meniscectomy is highly impacted by difficulties in estimating the thin vascularization of the meniscus, which determines the healing capacities of the patient. Indeed, vascularization is estimated using arthroscopic cameras that lack of high sensitivity to blood flow. Here, we propose an ultrasound method for estimating the density of vascularization in the meniscus during surgery. This approach uses an arthroscopic probe driven by ultrafast sequences. To enhance the sensitivity of the method, we propose to use a chirp-coded excitation combined with a mismatched compression filter robust to the attenuation. This chirp approach was compared to a standard ultrafast emission and a Hadamard-coded emission using a flow phantom. The mismatched filter was also compared to a matched filter. Results show that, for a velocity of a few millimeters per second, the mismatched filter gives a 4.4-10.4-dB increase of the signal-to-noise ratio (SNR) compared to the Hadamard emission and a 3.1-6.6-dB increase compared to the matched filter. Such increases are obtained for a loss of axial resolution of 13% when comparing the point spread functions (PSFs) of the mismatched and matched filters. Hence, the mismatched filter allows increasing significantly the probe capacity to detect slow flows at the cost of a small loss in axial resolution. This preliminary study is the first step toward an ultrasensitive ultrasound arthroscopic probe able to assist the surgeon during meniscectomy.

The triply periodic minimal surface-based 3D printed engineering scaffold for meniscus function reconstruction

Background

The meniscus injury is a common disease in the area of sports medicine. The main treatment for this disease is the pain relief, rather than the meniscal function recovery. It may lead to a poor prognosis and accelerate the progression of osteoarthritis. In this study, we designed a meniscal scaffold to achieve the purposes of meniscal function recovery and cartilage protection.

Methods

The meniscal scaffold was designed using the triply periodic minimal surface (TPMS) method. The scaffold was simulated as a three-dimensional (3D) intact knee model using a finite element analysis software to obtain the results of different mechanical tests. The mechanical properties were gained through the universal machine. Finally, an in vivo model was established to evaluate the effects of the TPMS-based meniscal scaffold on the cartilage protection. The radiography and histological examinations were performed to assess the cartilage and bony structures. Different regions of the regenerated meniscus were tested using the universal machine to assess the biomechanical functions.

Results

The TPMS-based meniscal scaffold with a larger volume fraction and a longer functional periodicity demonstrated a better mechanical performance, and the load transmission and stress distribution were closer to the native biomechanical environment. The radiographic images and histological results of the TPMS group exhibited a better performance in terms of cartilage protection than the grid group. The regenerated meniscus in the TPMS group also had similar mechanical properties to the native meniscus.

Conclusion

The TPMS method can affect the mechanical properties by adjusting the volume fraction and functional periodicity. The TPMS-based meniscal scaffold showed appropriate features for meniscal regeneration and cartilage protection.

Cost-Effectiveness Analysis of a Medial Meniscus Replacement Prosthesis for the Treatment of Patients with Medial Compartment Pain in the United Kingdom

BACKGROUND

The most common intra-articular knee injury is a meniscal tear, which commonly occurs secondary to trauma following twisting or hyperflexion. Treatment options for meniscal tears can either be surgical or non-surgical, and range from rest, exercise, bracing and physical therapy to surgical intervention, including meniscal repair and partial meniscectomy. In patients with persistent pain following loss of meniscus tissue, treatment can include partial replacement or meniscal allograft transplantation. The NUsurface^® prosthesis has been developed as a treatment option for patients experiencing persistent knee pain post medial meniscus (MM) surgery.

OBJECTIVE

The aim of this study was to assess the cost effectiveness of MM replacement using NUsurface for the treatment of patients with medial compartment pain following previous partial medial meniscectomy, from a UK health service perspective.

METHODS

An economic decision-analytic model was developed to assess the cost per quality-adjusted life-year (QALY) gained associated with the introduction of MM replacement using NUsurface compared with non-surgical standard of care, over a lifetime time horizon. The model structure was primarily informed by a previous clinical trial (VENUS) and was developed based on the clinical pathways typically followed by patients with this condition, with treatment pathways and probabilities of clinical progression adjusted depending on whether patients were receiving the intervention or undergoing current practice. A hypothetical cohort of adult patients (mean age of 50 years) was modelled, with clinical data sourced from the VENUS study as well as relevant UK literature. Both deterministic and probabilistic sensitivity analyses were carried out to explore uncertainty in the model results.

RESULTS

The base-case probabilistic results indicate that MM replacement using NUsurface is likely to be cost effective across a range of willingness-to-pay (WTP) thresholds (95% probability of being cost effective at the National Institute for Health and Care Excellence (NICE)-recommended £20,000 WTP threshold). Although per-patient costs increase, QALYs are also gained, with the incremental cost per QALY (probabilistic value = £5011) being below £20,000. Deterministic sensitivity analyses indicate that the parameters that have the greatest impact on results are the failure rate in the control group (current practice), utility scores, and the cost of undergoing MM replacement using NUsurface.

CONCLUSIONS

Based on the analysis presented, MM replacement with the NUsurface prosthetic implant is likely to be a cost-effective use of UK health care service resources compared with current standard care.

Arthroscopic Meniscal Repair With Second-Generation Platelet-Rich Fibrin Clot Augmentation

Meniscal tears are among the most common injuries in the knee, and partial as well as total meniscectomy has been advocated as the treatment for meniscal injury. Over the years, the role of the meniscus as a shock absorber, load transmitter, and secondary anterior stabilizer, along with its proprioceptive and lubrication role, has been well established, and meniscal repair is recommended, especially in younger individuals. Factors such as tear location, pattern, chronicity, size, and extent; repair technique; and patient age and habits can influence meniscal repair, and to enhance meniscal healing, a variety of augmentation techniques have been introduced. These include needling, trephination, synovial abrasion, and the use of adjuvants such as platelet-rich plasma, platelet clots, fibrin clots, bone marrow clots, and stem cells. A second-generation platelet derivative called "platelet-rich fibrin" (PRF) has predictable platelet, growth factor, and cell mediator concentrations without using any anticoagulants. We describe a reproducible and simple way to harvest PRF and create and use a PRF clot, along with detailed instructions on how to integrate the clot with a meniscal repair arthroscopically.

Arthroscopic meniscus repair and augmentation with autologous fibrin clot in Indian population: A 2-year prospective study

INTRODUCTION

This study was proposed to evaluate the efficacy of fibrin clot augmentation in meniscal tear using inside-out meniscal repair.

METHODS

A total of 35 patients with meniscus tears were operated on with inside-out meniscus repair and fibrin clot augmentation. Patients were evaluated preoperatively and postoperatively with clinical criteria, Lysholm knee scoring system, and MRI.

RESULTS

Out of the total 35 cases, 5 cases were lost to follow-up. Clinical improvement was observed in 29 out of 30 patients (96.6%). The mean Lysholm score improved significantly from 67.63 ± 6.55 points preoperatively to 92.0 ± 2.9 points postoperatively (P < 0.05) in 3 years follow-up. Follow-up MRI in all patients revealed complete healing except in 1 case where the patient presented with recurrence of symptoms such as pain and locking which resolved with partial meniscectomy. Paraesthesia in the anterior part of the knee was observed in 2 cases. (6.6%).

CONCLUSION

We conclude that fibrin clot augmentation is a good cost-effective modality of treatment for repairable meniscus tears to preserve the meniscus and decrease the point contact pressure on the condyles which may prevent the early occurrence of osteoarthritis.

Biomechanical Comparison of Meniscal Allograft Root Fixation Techniques: Anterograde Interference Bone Plug Fixation Yields Favorable Results Compared to Transosseous Suture Fixation Alone

Purpose

To compare the biomechanical properties of 2 different fixation techniques (interference bone plug fixation vs transosseous suture fixation) of the posterior horn of the medial meniscus using a porcine model.

Methods

Twenty-six matched pairs of fresh-frozen juvenile domestic porcine knees were used in this study. Specimens were randomly distributed among 3 groups: (1) native meniscus groups, (2) interference fixation, and (3) transosseous suture fixation. In each group, the posterior segments of the tested medial menisci were gripped with the freeze clamps and fixed to the tensile testing machine. Samples were preconditioned, followed by cyclic tension-relaxation for 1000 cycles between 10 and 30 N at 0.5 Hz and finally pulled to failure at a rate of 0.55 mm/s. The cyclic elongation, stiffness to failure, mode, and ultimate load to failure were recorded.

Results

There was no significant difference in ultimate load to failure between the interference fixation (169.71 ± 71.98 N) and transosseous suture fixation (222.73 ± 72.40 N) groups (P = .118), both were significantly less than that of the native meniscus (405.46 ± 95.62) (P < .001). Interference fixation displayed cyclic elongation (1.04 ± 0.71 mm) and stiffness (69.10 ± 25.8 N/mm) that were not significantly different from the native meniscus tissue (0.78 ± 0.53 mm and 83.1 ±26.28 N/mm) (P = .359 and P = .224), in comparison to transosseous suture fixation, which did show increased cyclic elongation (1.85 ± 1.44 mm) (P = .047) and decreased stiffness (34.72 ± 10.2 N/mm) (P < .001).

Conclusion

Interference fixation of the posterior horn of the medial meniscus has superior cyclic elongation and stiffness when compared to transosseous suture fixation. Interference fixation and the native meniscus model have a similar stiffness and cyclic elongation.

Clinical Relevance

The significance of our study is that using interference fixation for meniscal allograft transplantation has the potential to reduce short term surgical failures as well as long term complication rates.

Meniscus Tear: Pathology, Incidence, and Management

Meniscus tears are a common orthopedic pathology and planning a single, effective treatment is challenging. The diagnosis of meniscal tears requires detailed history-taking, physical examinations, special diagnostic tests, and most likely magnetic resonance imaging (MRI) to confirm the lesion. A good understanding of the meniscal structure including vascularity, zones, function, and affected movements with associated symptoms plays a crucial role in establishing an optimal management plan. A careful assessment of the patient's characteristics, comorbidities, post-repair rehabilitation, and patient’s overall function and satisfaction are also important for ideal management. While conservative management is commonly implemented and the only option for certain patients, partial meniscectomy remains to be the most performed treatment procedure. However, partial meniscectomy is no longer the first-line therapy due to the limitation of certain patient characteristics and side effects in the long run. Instead, meniscal repair has been shown to have better long-term outcomes and is therefore recommended for all tears, especially for young patients with acute traumatic lesions. Tissue engineering has been of high interest in the current research with promising therapeutic results. This review critically evaluates and compares the management of meniscal tears with surgical versus comprehensive management using the current literature.

Meniscus regeneration by 3D printing technologies: Current advances and future perspectives

Meniscal tears are a frequent orthopedic injury commonly managed by conservative strategies to avoid osteoarthritis development descending from altered biomechanics. Among cutting-edge approaches in tissue engineering, 3D printing technologies are extremely promising guaranteeing for complex biomimetic architectures mimicking native tissues. Considering the anisotropic characteristics of the menisci, and the ability of printing over structural control, it descends the intriguing potential of such vanguard techniques to meet individual joints’ requirements within personalized medicine. This literature review provides a state-of-the-art on 3D printing for meniscus reconstruction. Experiences in printing materials/technologies, scaffold types, augmentation strategies, cellular conditioning have been compared/discussed; outcomes of pre-clinical studies allowed for further considerations. To date, translation to clinic of 3D printed meniscal devices is still a challenge: meniscus reconstruction is once again clear expression of how the integration of different expertise (e.g., anatomy, engineering, biomaterials science, cell biology, and medicine) is required to successfully address native tissues complexities.

Medial Meniscal Allograft Transplantation With Bone Plugs Using a 3-Tunnel Technique

Meniscal allograft transplantation is an area of active research, given that the importance of the meniscus in native knee joint longevity has been increasingly recognized. This article describes a modified meniscal allograft transplantation technique using 3 bone tunnels with allograft fixation through the use of bone plugs. The addition of a third tunnel increases the strength of fixation, avoiding meniscal extrusion and improving load distribution.

Three-Dimensional-Printed Scaffolds for Meniscus Tissue Engineering: Opportunity for the Future in the Orthopaedic World

The meniscus is a critical component of a healthy knee joint. It is a complex and vital fibrocartilaginous tissue that maintains appropriate biomechanics. Injuries of the meniscus, particularly in the inner region, rarely heal and usually progress into structural breakdown, followed by meniscus deterioration and initiation of osteoarthritis. Conventional therapies range from conservative treatment, to partial meniscectomy and even meniscus transplantation. All the above have high long-term failure rates, with recurrence of symptoms. This communication presents a brief account of in vitro and in vivo studies and describes recent developments in the field of 3D-printed scaffolds for meniscus tissue engineering. Current research in meniscal tissue engineering tries to combine polymeric biomaterials, cell-based therapy, growth factors, and 3D-printed scaffolds to promote the healing of meniscal defects. Today, 3D-printing technology represents a big opportunity in the orthopaedic world to create more specific implants, enabling the rapid production of meniscal scaffolds and changing the way that orthopaedic surgeons plan procedures. In the future, 3D-printed meniscal scaffolds are likely to be available and will also be suitable substitutes in clinical applications, in an attempt to imitate the complexity of the native meniscus.

All-Cause Failure Rates Increase With Time Following Meniscal Repair Despite Favorable Outcomes: A Systematic Review and Meta-analysis

PURPOSE

The purpose of this review is to perform a meta-analysis of studies reporting meniscus repair outcomes. Pooled analyses of such studies will provide an accurate estimate of the outcomes that can be expected following meniscal repair at various postoperative time points.

METHODS

A meta-analysis of meniscal repair failure (defined as persistent symptoms, lack of healing on magnetic resonance imaging or revision surgery) and other clinical outcomes was performed following meniscal repair. Patients included had traumatic, nondegenerative meniscal tears, were skeletally mature, and had specific time-points after surgery. Repairs included were performed either in isolation, or with concomitant ACL reconstruction. Because of the inherent heterogeneity of single-arm meta-analyses, pooled analyses were performed using a random-effects model.

RESULTS

Rates of all-cause meniscal repair failure was pooled to be 12% at 0-1 years (95% CI: .09-.16), 15% at 2-3 years (95% CI: .11-.20), and 19% at 4-6 years (95% CI: .13-.24). Sensitivity analysis for studies performing meniscal repair entirely on patients with concomitant ACL reconstruction (ACLR) showed comparable rates of failure at similar time intervals. Development of osteoarthritis, in patients with knees previously free from articular pathologies, was 4% at 2-3 years (95% CI: .02-.07), and 10% at 4-6 years (95% CI: .03-.25).

CONCLUSION

Meniscus repair for traumatic injuries have an all-cause failure rate that increases from 12% to 19% through a time period ranging from 1-6 years following surgery. The failure rates were comparable for patients with meniscal repairs performed with concomitant ACLRs.

LEVEL OF EVIDENCE

IV; Systematic Review of Level II-IV Studies.

Biologic Augmentation during Meniscal Repair

We reviewed the literature regarding utility of biologic augmentation in meniscal repair. We hypothesized that the addition of biologic augmentation during meniscal repair improves postoperative knee function and reduces risk of repair failure. PubMed and Embase databases were systematically searched. Included studies were clinical studies in humans, published in English, and reported use of biologic augmentation techniques in addition to meniscal repair (including platelet-rich plasma [PRP], fibrin clot, bone marrow stimulation, meniscal wrapping, and bioscaffolds) for treatment of knee meniscal tears. Outcome measures included repair failure, repeat knee arthroscopic surgery, and magnetic resonance imaging), visual analog scale for pain, the International Knee Documentation Committee questionnaire, the Western Ontario and McMaster Universities Osteoarthritis Index Lysholm's Knee Scoring Scale, and the Knee Injury and Osteoarthritis Outcome Score. Study quality was assessed using the modified Coleman methodology score. Nineteen studies reported repair of 1,092 menisci including six studies that investigated fibrin clot augmentation, five studies that investigated PRP augmentation, three studies that investigated bone marrow stimulation augmentation, two studies that used meniscal wrapping augmentation, and three studies that used other techniques. The level of evidence ranged from I to IV and mean modified Coleman methodology score was 43 (range: 17-69), with higher scores noted in studies completed in recent years. PRP and bone marrow stimulation augmentation appear to decrease risk of failure in patients undergoing isolated meniscal repair but do not improve knee symptom scores. Fibrin clot and trephination augmentation techniques do not have sufficient evidence to support decreased failure risk at this time. Meniscal wrapping augmentation and scaffold implantation augmentation appear to be an attractive option to meniscectomy in complicated tears that are not candidates for repair alone, but further confirmatory studies are needed to support initial data. Evidence supporting augmentation of meniscal repair is limited at this time but suggests that the highest likelihood for effectiveness of augmentation is in the settings of isolated meniscal repair or meniscal repairs that would normally not be amenable to repair.

Six-Month Outcomes of Clinically Relevant Meniscal Injury in a Large-Animal Model

BACKGROUND

The corrective procedures for meniscal injury are dependent on tear type, severity, and location. Vertical longitudinal tears are common in young and active individuals, but their natural progression and impact on osteoarthritis (OA) development are not known. Root tears are challenging and they often indicate poor outcomes, although the timing and mechanisms of initiation of joint dysfunction are poorly understood, particularly in large-animal and human models.

PURPOSE/HYPOTHESIS

In this study, vertical longitudinal and root tears were made in a large-animal model to determine the progression of joint-wide dysfunction. We hypothesized that OA onset and progression would depend on the extent of injury-based load disruption in the tissue, such that root tears would cause earlier and more severe changes to the joint.

STUDY DESIGN

Controlled laboratory study.

METHODS

Sham surgeries and procedures to create either vertical longitudinal or root tears were performed in juvenile Yucatan mini pigs through randomized and bilateral arthroscopic procedures. Animals were sacrificed at 1, 3, or 6 months after injury and assessed at the joint and tissue level for evidence of OA. Functional measures of joint load transfer, cartilage indentation mechanics, and meniscal tensile properties were performed, as well as histological evaluation of the cartilage, meniscus, and synovium.

RESULTS

Outcomes suggested a progressive and sustained degeneration of the knee joint and meniscus after root tear, as evidenced by histological analysis of the cartilage and meniscus. This occurred in spite of spontaneous reattachment of the root, suggesting that this reattachment did not fully restore the function of the native attachment. In contrast, the vertical longitudinal tear did not cause significant changes to the joint, with only mild differences compared with sham surgery at the 6-month time point.

CONCLUSION

Given that the root tear, which severs circumferential connectivity and load transfer, caused more intense OA compared with the circumferentially stable vertical longitudinal tear, our findings suggest that without timely and mechanically competent fixation, root tears may cause irreversible joint damage.

CLINICAL RELEVANCE

More generally, this new model can serve as a test bed for experimental surgical, scaffold-based, and small molecule-driven interventions after injury to prevent OA progression.

Use of an Accessory Anteromedial Portal to Facilitate Repair of Mid-Body Radial Tears of the Lateral Meniscus in Children and Adolescents

Meniscal tears in adolescent patients are commonly treated with repair to preserve meniscal tissue and prevent future degenerative changes. Historically, meniscal tears best suited for repair are acute vertical tears in patients aged <40 years with a normal mechanical axis, >1 cm and <4 cm in size, within the red-red zone, and concurrent with anterior cruciate ligament reconstruction. However, with continued advancements in technology and the development of new techniques, the possibilities and indications for meniscal repair have broadened. This paper presents the use of an accessory medial portal to facilitate the repair of radial tears of the mid-body of the lateral meniscus. Previous techniques described include all-inside, outside-in, and inside-out repairs, but these techniques can be challenging to achieve optimal simultaneous meniscus reduction, visualization, and suture trajectory. In this Technical Note, we describe the use of an inside-out technique, with emphasis on an accessory anteromedial portal to improve visualization and suture trajectory.

Leaving the stable ramp lesion unrepaired does not negatively affect clinical and functional outcomes as well as return to sports rates after ACL reconstruction

PURPOSE

To evaluate the effects of untreated stable ramp lesions on clinical and functional outcomes, return to sports rates, and complications of patients who underwent anterior cruciate ligament reconstruction.

METHODS

A total of 879 patients with anterior cruciate ligament rupture were evaluated. Of these, 66 patients [33 patients with anterior cruciate ligament rupture and stable medial meniscal ramp lesion (ramp + group) and 33 patients with isolated anterior cruciate ligament rupture (ramp - group)] with a minimum 3-year of follow-up were included. Stable ramp lesions were not repaired in the ramp + group. Preoperative and postoperative Lachman and pivot-shift grades, Lysholm knee scores, International Knee Documentation Committee score and 12-Item Short Form Health Survey score were compared between groups. The return to sports rates, level of return to sports, time to return to sports and complications were compared.

RESULTS

The mean patient age was 27.8 ± 7.2 years. The mean follow-up period was 47.3 ± 9.4 months. There were no significant differences between groups regarding preoperative and postoperative Lachman and pivot-shift grades, 12-Item Short Form Health Survey mental and physical component summary scores, Lysholm and International Knee Documentation Committee scores, and complication rates (n.s.). Although the return to sports rates (84.8% vs 90.1%) and the level of the return to sports (return to preinjury level: 75% vs 78%) were similar between groups (n.s.), the time to return to sports was significantly longer for patients with ramp lesions (11.1 ± 4.0 vs. 8.7 ± 2.5 months, p = 0.007).

CONCLUSION

Leaving the stable ramp lesion unrepaired does not negatively affect clinical and functional outcomes as well as return to sports rates after ACL reconstruction. However, the time to return to sports is prolonged in patients with ramp lesions In clinical practice, surgeons should be aware that repairing stable ramp lesions is not an absolute necessity and will not affect return to sport rates.

LEVEL OF EVIDENCE

Level III.

Does Surgery for Cruciate Ligament and Meniscus Injury Increase the Risk of Comorbidities at 2 Years in the Military System?

This study aims to determine whether surgery for cruciate ligament (anterior or posterior) or meniscus injury increased risks of subsequent comorbidities in beneficiaries of the Military Health System. The study was a retrospective case-control design in which individuals with cruciate or meniscus injuries were divided into two groups (surgery or none). Data were pulled 12 months prior and 24 months following each respective event and presence of comorbidities were compared between the two groups. Bivariate analyses and logistic regression were used to determine if surgery increased the odds of comorbidities. Participants included 1,686 with a cruciate ligament injury (30.1% treated surgically) and 13,146 with a meniscus injury (44.4% treated surgically). Bivariate comparisons of surgery versus nonsurgical treatment found multiple significant differences. After adjusting for covariates, a significant (p < 0.05) protective effect was seen only for meniscus surgery for concussion, insomnia, other mental health disorders, depression, and substance abuse. Surgery had no increased/decreased risk of comorbidities for cruciate ligament injuries. For meniscus injuries, surgery demonstrated a protective effect for six of the comorbidities we assessed. The treatment approach (surgery vs. nonsurgical) did not change the risk of comorbidities in those with a cruciate ligament injury. It is noteworthy that three of the six comorbidities involved mental health disorders. Although the study design does not allow for determination of causation, these findings should compel future prospective study designs that could confirm these findings.

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.

Extracellular vesicles derived from mesenchymal stromal cells mediate endogenous cell growth and migration via the CXCL5 and CXCL6/CXCR2 axes and repair menisci

Background

Mesenchymal stromal cell-derived extracellular vesicles (MSC-EVs) are promising candidates for tissue regeneration therapy. However, the therapeutic efficacy of MSC-EVs for meniscus regeneration is uncertain, and the mechanisms underlying MSC-EV-mediated tissue regeneration have not been fully elucidated. The aims of this study were to evaluate the therapeutic efficacy of intra-articular MSC-EV injection in a meniscus defect model and elucidate the mechanism underlying MSC-EV-mediated tissue regeneration via combined bioinformatic analyses.

Methods

MSC-EVs were isolated from human synovial MSC culture supernatants via ultrafiltration. To evaluate the meniscus regeneration ability, MSC-EVs were injected intra-articularly in the mouse meniscus defect model immediately after meniscus resection and weekly thereafter. After 1 and 3 weeks, their knees were excised for histological and immunohistochemical evaluations. To investigate the mechanisms through which MSC-EVs accelerate meniscus regeneration, cell growth, migration, and chondrogenesis assays were performed using treated and untreated chondrocytes and synovial MSCs with or without MSC-EVs. RNA sequencing assessed the gene expression profile of chondrocytes stimulated by MSC-EVs. Antagonists of the human chemokine CXCR2 receptor (SB265610) were used to determine the role of CXCR2 on chondrocyte cell growth and migration induced by MSC-EVs.

Results

In the meniscus defect model, MSC-EV injection accelerated meniscus regeneration and normalized the morphology and composition of the repaired tissue. MSC-EVs stimulated chondrocyte and synovial MSC cell growth and migration. RNA sequencing revealed that MSC-EVs induced 168 differentially expressed genes in the chondrocytes and significantly upregulated CXCL5 and CXCL6 in chondrocytes and synovial MSCs. Suppression of CXCL5 and CXCL6 and antagonism of the CXCR2 receptor binding CXCL5 and CXCL6 negated the influence of MSC-EVs on chondrocyte cell growth and migration.

Conclusions

Intra-articular MSC-EV administration repaired meniscus defects and augmented chondrocyte and synovial MSC cell growth and migration. Comprehensive transcriptome/RNA sequencing data confirmed that MSC-EVs upregulated CXCL5 and CXCL6 in chondrocytes and mediated the cell growth and migration of these cells via the CXCR2 axis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02481-9.

Development of a decellularized meniscus matrix-based nanofibrous scaffold for meniscus tissue engineering

The meniscus plays a critical role in knee mechanical function but is commonly injured given its central load bearing role. In the adult, meniscus repair is limited, given the low number of endogenous cells, the density of the matrix, and the limited vascularity. Menisci are fibrocartilaginous tissues composed of a micro-/nano- fibrous extracellular matrix (ECM) and a mixture of chondrocyte-like and fibroblast-like cells. Here, we developed a fibrous scaffold system that consists of bioactive components (decellularized meniscus ECM (dME) within a poly(e-caprolactone) material) fashioned into a biomimetic morphology (via electrospinning) to support and enhance meniscus cell function and matrix production. This work supports that the incorporation of dME into synthetic nanofibers increased hydrophilicity of the scaffold, leading to enhanced meniscus cell spreading, proliferation, and fibrochondrogenic gene expression. This work identifies a new biomimetic scaffold for therapeutic strategies to substitute or replace injured meniscus tissue. STATEMENT OF SIGNIFICANCE: In this study, we show that a scaffold electrospun from a combination of synthetic materials and bovine decellularized meniscus ECM provides appropriate signals and a suitable template for meniscus fibrochondrocyte spreading, proliferation, and secretion of collagen and proteoglycans. Material characterization and in vitro cell studies support that this new bioactive material is susceptible to enzymatic digestion and supports meniscus-like tissue formation.

Return-to-Sport Rate and Activity Level Are High Following Arthroscopic All-Inside Meniscal Repair With and Without Concomitant Anterior Cruciate Ligament Reconstruction: A Systematic Review

PURPOSE

To systematically review the literature of return-to-sport outcomes following all-inside meniscus repair and evaluate whether concomitant anterior cruciate ligament reconstruction (ACLR) influenced these outcomes.

METHODS

A systematic review of the MEDLINE, PubMed, Embase, and Cochrane Registry of Systematic Reviews databases was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Two reviewers examined all literature pertaining to sport outcomes following all-inside meniscal repair. Studies were included if they had a 12-month minimum follow-up and reported return to sport rate, Tegner, or Knee injury and Osteoarthritis Outcome Score (KOOS) Sport outcomes. Studies with meniscal repair techniques other than the all-inside technique were excluded. Studies were not excluded if they contained patients receiving concomitant ACLR. Study quality was evaluated with the Methodological Index for Nonrandomized Studies.

RESULTS

Nineteen studies comprising 872 patients were included in this investigation. The weighted average patient age was 28.7 (range 14.1-42.1) years, and the weighted average follow-up was 56.0 (range 18.0-155.0) months. The mean Methodological Index for Nonrandomized Studies score was 14.4 ± 3.7. Ten investigations reported both preoperative (range 2.3-3.5) and postoperative (range 4.0-7.3) Tegner outcomes, with scores at final follow-up greater in each of the 10 reporting investigations. KOOS Sport outcomes were examined in 5 investigations, with scores at follow-up ranging from 63.6 to 91. Three studies reported a return to sport rate ranging from 89.6 to 90% at follow-up. Four investigations compared sport-related outcomes between isolated meniscal repair and meniscal repair with concomitant ACLR. Two such studies reported no difference between the 2 cohorts, 1 favored the isolated cohort, and 1 favored the combined cohort.

CONCLUSIONS

This systematic review found a 90% return-to-sport rate and high postoperative activity level following all-inside meniscal repair, as assessed by KOOS Sport and Tegner activity scales. Further, concurrent ACLR did not significantly affect these outcomes.

LEVEL OF EVIDENCE

IV, systematic review of level I-IV studies.

Autologous Minimally Invasive Cell-Based Therapy for Meniscal and Anterior Cruciate Ligament Regeneration

The meniscus is a fibrocartilaginous tissue that acts as a “shock absorber,” along with performing functions such as stabilization and lubrication of the joint, proprioception, and load distribution. Sudden twisting movements during weight bearing or trauma can cause injury to the menisci, which leads to symptoms such as pain, swelling, and difficulty in performing movements, among others. Conventional pharmacological and surgical treatments are effective in treating the condition; however, do not result in regeneration of healthy tissues. In this report, we highlight the role of cell-based therapy in the management of medial and lateral meniscal and anterior cruciate ligament tears in a patient who was unwilling to undergo surgical treatment. We injected autologous mesenchymal stem cells obtained from the bone marrow and adipose tissue and platelet-rich plasma into the joint of the patient at the area of injury, as well as intravenously. The results of our study corroborate with those previously reported in the literature regarding the improvement in clinical parameters and regeneration of meniscal tissue and ligament. Thus, based on previous literature and improvements noticed in our patient, cell-based therapy can be considered a safe and effective therapeutic modality in the treatment of meniscal tears and cruciate ligament injury.

All-inside repair of bucket handle meniscus tears - Mid-term outcomes with postoperative magnetic resonance imaging

PURPOSE

The purpose of this study was to evaluate our results of bucket handle meniscus tear (BHMT) repairs with an all-inside repair technique using postoperative radiological imaging to evaluate meniscus reduction and healing and use them as criteria for evaluation of repair success.

METHODS

Prospective recruitment of 20 patients with 21 BHMT repairs performed with an all-inside techniqueover a period from 2013 to 2015. All patients had an International Knee Documentation Committee (IKDC) Subjective Knee Form (SKF), Lysholm Score, Knee Injury and Osteoarthritis Outcome Score (KOOS) and Tegner Activity Level Scale obtained pre-operatively and at a minimum of 24 months after surgery. All patients had postoperative knee magnetic resonance imaging (MRI) performed between 18 and 24 months after surgery to assess the stability or failure of their repairs.At 5 years after surgery, the patients were assessed with regard to whether they had undergone repeat surgery or not.

RESULTS

At 2 years, the mean postoperative SKF, Lysholm and KOOS grand scores were 78.9, 88.5 and 86.8, respectively. The mean pre-injury Tegner Activity Scale was 7.6 and postoperatively it was 6.0. There was a significant difference in all pre- and postoperative outcome scores (P < 0.01). The postoperative MRIs showed that 19 of the 21 BHMT repairs had stable reduction of the tear fragment and two patients had displacement of the torn bucket handle fragment. At 5 years, one patient had undergone revision surgery.

CONCLUSION

BHMTs can be repaired with all-inside techniques with good results and successful outcomes.

Long-term National Trends of Arthroscopic Meniscal Repair and Debridement

BACKGROUND

Optimal treatment of meniscal pathology continues to evolve in orthopaedic surgery, with a growing understanding of which patients benefit from which procedure and which patients might be best treated nonsurgically. In 2002, Moseley et al found no difference between arthroscopic procedures, including meniscal debridement and sham surgery, in patients with osteoarthritis of the knee. This called into question the role of routine arthroscopic debridement in these patients. Additionally, an increased interest in understanding and maintaining the function of the meniscus has more recently resulted in a greater focus on meniscal preservation procedures.

STUDY DESIGN

Descriptive epidemiology study.

PURPOSE/HYPOTHESIS

The purpose was to evaluate the trends of arthroscopic meniscal debridement and repair and the characteristics of the patients receiving these treatments, compare the differences in practice between newly trained orthopaedic sports medicine specialists and those of other specialties, and analyze if there are differences in practice by region. It was hypothesized that the American Board of Orthopaedic Surgery (ABOS) database would evaluate practice patterns of recent graduates as a surrogate for current treatment and training and, consequently, demonstrate a decreased rate of meniscal debridement.

METHODS

Data from ABOS Part II examinees from 2001 to 2017 were obtained from the ABOS Case List. Current Procedure Terminology (CPT) codes related to arthroscopic meniscal treatment were selected. The examination year, age of the patient, practice region, and examinee subspecialty were analyzed. Patient age was stratified into 4 groups: <30, 30 to 50, 51 to 65, and >65 years. Examinee subspecialty was stratified into sports medicine and non-sports medicine. Statistical regression analysis was performed.

RESULTS

Between 2001 and 2017, ABOS Part II examinees submitted 131,047 cases with CPT codes 29880 to 29883. Meniscal debridement volume decreased for all age groups during the study period, while repair increased. Sports medicine subspecialists were more likely than their counterparts to perform repair over debridement in patients aged younger than 30 years (P = .0004) and between 30 and 50 years (P = .0005).

CONCLUSION

This study provides insights into arthroscopic meniscal debridement and repair practice trends among ABOS Part II examinees. Meniscal debridement is decreasing and meniscal repair is increasing. Younger patient age and treatment by a sports medicine subspecialty examinee are associated with a higher likelihood of repair over debridement.

Imaging of knee osteoarthritis: A review of current evidence and clinical guidelines

BACKGROUND

Knee osteoarthritis (OA) is one of the most common and debilitating degenerative joint diseases worldwide. While radiography is the most commonly used imaging modality, it is associated with drawbacks which newer modalities such as magnetic resonance imaging (MRI) and ultrasound could overcome. Nevertheless, the role of imaging in clinical practice and research in knee OA has not been clearly defined. Furthermore, guidelines on imaging in knee OA from different authoritative bodies have not been compared in previous studies. Therefore, the present review aims to summarise existing evidence and compare guidelines on the use of different imaging modalities in evaluating knee OA.

METHODS

This is a narrative review based on a search of published clinical guidelines and the PubMed database for articles published between 1 January 1990 and 31 May 2020.

RESULTS

There is no broad consensus on the value of imaging in patients with typical OA presentation. If imaging is required, current evidence and clinical guidelines support the use of radiography and MRI as first- and second-line diagnostic modalities respectively. Since radiographic OA features have limited sensitivity and do not manifest in early stages, MRI is the preferred option for whole-joint evaluation in OA research. Discrepancies exist regarding the use of alternative imaging modalities including ultrasound, computed tomography and nuclear medicine.

CONCLUSION

Radiography and MRI are the imaging modalities of choice. Other modalities have their respective advantages, and more research is warranted for the standardisation of image acquisition and interpretation methodology, in order to evaluate their validity, reliability and responsiveness in OA research.