Long-term outcome of meniscectomy: symptoms, function, and performance tests in patients with or without radiographic osteoarthritis compared to matched controls

Partial Meniscectomy Increases Risk of ACL Revision Surgery Compared to Meniscus Repair in Patients with Concurrent Meniscus and ACL Tears after ACL Reconstruction

PURPOSE

To compare the rates of revision ACL reconstruction, meniscal reoperation, and total knee arthroplasty (TKA) associated with partial meniscectomy and meniscal repair performed at the time of index ACL reconstruction in patients with concurrent meniscus and ACL tears.

METHODS

The TriNetX database was queried for patients undergoing ACL reconstruction following January 1, 2000, with minimum one year clinical follow up. Inclusion criteria for this study were patients who had partial meniscectomy, meniscal repair, or isolated ACL reconstruction without meniscus injury. Statistical analyses were performed using Python with significance thresholds of p < 0.05.

RESULTS

A total of 39,126 patients were followed for an average of 5.02 years. Patients undergoing meniscal repair were less likely to experience revision ACL reconstruction compared to those undergoing partial meniscectomy (RR: 0.78, CI: 0.71-0.85, p < 0.001). Meniscus reoperation occurred significantly more in patients undergoing meniscal repair (RR: 1.26, CI: 1.17-1.35, p = <0.001) than those undergoing partial meniscectomy. Regarding TKA, partial meniscectomy carried a more than sixfold increased risk compared to isolated ACL reconstruction (RR: 6.4, CI: 2.49-16.42, p < 0.001).

CONCLUSIONS

In patients with ACL injury, ACL reconstruction, and concurrent meniscus tear, those patients treated with meniscus repair were less likely to undergo revision surgery. In these patients, medial meniscal injuries were associated with ACL revision than lateral meniscal injury regardless of the method of treatment. When meniscus repair is performed, this is associated with lower rate of future total knee arthroplasty.

LEVEL OF EVIDENCE

Level III Retrospective Cohort Study.

Report on Evolving Indications, Technique, and Outcomes of Novel And Surgical Procedures-NUsurface

PURPOSE OF REVIEW

Meniscectomy alters knee function and known to be associated with an increased incidence of knee arthritis. Several methods and materials have been tried to replicate the function of a meniscus. One is a polycarbonate-urethane synthetic medial meniscus implant labeled as NUsurface. It is a non-anchored implant that is meant to replace the native meniscus. This article is intended to give an overview of the NUsurface implant and the experience to date.

RECENT FINDINGS

The NUsurface implant is not intended to be a substitute for arthroplasty but has indications similar to meniscal allografts. It has had both prospective double armed and single armed prospective studies. Follow up at the 2-year mark has shown the implant can be successful in decreasing patients' pain and improving function. However, the reoperation rate has been high with a little over a 1/3 requiring an additional procedure and 30% requiring implant exchanged. With improved surgical technique and knowledge of contributing anatomic variables, the reoperation rate has been decreased by half. The synthetic medial meniscus implant NUsurface is able to improve the quality of life in select patients that are symptomatic after meniscectomy. The reoperation rate is of concern but it is decreasing as we refine the variables contributing to the high rate.

Tumor Necrosis Factor-Alpha (TNF-α) and Interleukin-6 (IL-6) Cytokines in the Injured Meniscus of Patients With Knee Subchondral Insufficiency Fractures: A Potential Association With Preoperative Pain

Background The development of subchondral insufficiency fracture (SIF) of the knee following a medial meniscal posterior root tear (MMPRT) results in pain and limitations in daily activities. Pain in patients with SIF is associated with local chronic inflammation in the knee joint, involving the production of inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and nerve growth factor (NGF). This study aimed to quantify the levels of proinflammatory cytokines (TNF-α, IL-6, NGF) in the injured medial meniscus (IMM) tissue of patients with knee SIF and examine their potential association with preoperative pain and functional scores. Methods Meniscus samples were collected from 17 patients with knee SIF (mean age: 62.8 ± 2.6 years) who underwent total knee arthroplasty. The tissue samples were categorized into two groups based on the degree of injury: the IMM and the non-injured healthy lateral meniscus (HLM) as the control group. The levels of TNF-α, IL-6, and NGF in both groups were measured using an enzyme-linked immunosorbent assay (ELISA), and differences were evaluated with the Wilcoxon signed-rank test. The association between preoperative functional and pain scores and the levels of each inflammatory mediator was analyzed using Spearman's correlation. Results TNF-α and IL-6 were detectable in the meniscus tissues, while NGF levels were negligible. The levels of TNF-α and IL-6 were significantly higher in the IMM group compared to the HLM group (p<0.05). Furthermore, TNF-α and IL-6 levels in the IMM group were correlated with the pain subscale of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Conclusions This study demonstrated a significant increase in TNF-α and IL-6 cytokine levels in the IMM compared to the non-injured healthy meniscus. These findings suggest that inflammatory mediators within the IMM may be associated with preoperative pain in patients with SIF in the medial femoral condyle resulting from MMPRT.

Partial Meniscectomy Yields Comparable Outcomes and Failure Rates to Meniscal Repair for Horizontal Cleavage Tears, With Fewer Complication Rates but Greater Progression of Degenerative Changes

PURPOSE

To compare the clinical outcomes, failure rates, surgical complications, and postoperative radiographic changes following partial meniscectomy versus meniscal repair for horizontal cleavage tears (HCTs).

METHODS

A literature search was performed according to the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using the Scopus, PubMed, and Embase computerized databases. Clinical studies evaluating partial meniscectomy or meniscal repair for HCTs were included. Demographic characteristics, surgical techniques, clinical outcomes, failure rates, complications, and radiographic assessments were recorded.

RESULTS

A total of 18 studies comprising 833 patients with HCTs were included, of which 562 patients (67.5%) were treated with partial meniscectomy and 271 (32.5%) with meniscal repair. Both types of treatments reported improved clinical outcomes, including International Knee Documentation Committee, Lysholm, Knee injury and Osteoarthritis Outcome Score, and Tegner scores. Failure rates were reported to range between 0% and 15% following partial meniscectomy and from 0% to 17.6% following repair; complications were 7.5% after partial meniscectomy and between 3.8% and 21.4% following meniscal repair. Patients undergoing meniscectomy demonstrated progression of degenerative changes on radiographic assessments.

CONCLUSIONS

Repair of HCTs in the appropriately indicated patient can result in similar patient outcomes and failure rates compared to partial meniscectomy. However, especially in patients aged 42 years and younger, a greater complication rate can be expected with repair, while a greater degree of ipsilateral compartment degeneration is seen after partial meniscectomy.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I to IV studies.

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.

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.

Rates of subsequent surgeries after meniscus repair with and without concurrent anterior cruciate ligament reconstruction

OBJECTIVES

The purpose of this study was to compare the rates of secondary knee surgery for patients undergoing meniscus repair with or without concurrent anterior cruciate ligament reconstruction (ACLr).

METHODS

Utilizing a large national database, patients with meniscal repair with or without concurrent arthroscopic ACLr were identified. The two cohorts were then queried for secondary surgical procedures of the knee within the following 2 years. Frequency, age distribution, rates of secondary surgery, and type of secondary procedures performed were compared.

RESULTS

In total, 1,585 patients were identified: meniscus repair with ACLr was performed for 1,006 (63.5%) and isolated meniscal repair was performed for 579 (36.5%). Minimum of two year follow up was present for 487 (30.7% of the overall study population). Secondary surgery rates were not significantly different between meniscus repair with concurrent ACLr and isolated meniscus repairs with an overall mean follow up of 13 years (1.5-24 years) (10.6% vs. 13.6%, p = 0.126). For the 2 year follow up cohort, secondary surgery rates were not significantly different (19.3% vs. 25.6%, p = 0.1098). There were no differences in survivorship patterns between the two procedures, both in the larger cohort (p = 0.2016), and the cohort with minimum 2-year follow-up (p = 0.0586).

CONCLUSION

The current study assessed secondary surgery rates in patients undergoing meniscus repair with or without concurrent ACLr in a large patient database. Based on this data, no significant difference in rates of secondary knee surgery was identified.

Influence of Meniscal Repair vs. Meniscectomy on Anterior Cruciate Ligament Reconstruction in Terms of Knee Stability and Radiological Imaging

The menisci are essential components in the pathophysiology of knee osteoarthritis. Patients with meniscal lesions and an intact anterior cruciate ligament (ACL) undergoing meniscectomy exhibit a significantly increased prevalence of radiographic osteoarthritis. ACL reconstruction surgery enhances knee stability and mitigates the advancement of minor meniscal tears. The purpose of this study was to show the influence of meniscal repair as compared to meniscectomy on anterior cruciate ligament reconstruction in terms of knee stability and radiological imaging. This was a retrospective study performed in Dr. D.Y. Patil Hospital, Pimpri, Pune, on a sample size of 30 patients between December 2021 and January 2023. Patients were followed up clinically and radiologically post-operatively at six months and one year. ACL reconstruction with meniscectomy was performed on 16 patients (group 2), while ACL reconstruction with meniscus repair was performed on 14 patients (group 1). At the end of six months in group 1, one patient out of 14 had a grade 2 Lachman test positive, while seven patients out of 16 had a grade 2 Lachman test positive in group 2. It was a statistically insignificant value (p>0.05). Further, at the end of 12 months, X-ray evaluation of the femoral tunnel shows an average increment of 0.5 mm in Group 1, while an average femoral tunnel widening of 3 mm was observed in Group 2. It was statistically insignificant (p>0.05). The study concluded that meniscus repair significantly increases anteromedial knee stability. It has been shown that meniscectomy, when done along with ACL reconstruction, increases the chances of femoral tunnel widening, resulting in less graft bone integration.

Free-floating medial meniscus implant kinematics do not change after simulation of medial open-wedge high tibial osteotomy and notchplasty

PURPOSE

The purpose of this in-vitro study was to examine the kinematics of an artificial, free-floating medial meniscus replacement device under dynamic loading situations and different knee joint states.

METHODS

A dynamic knee simulator was used to perform dynamic loading exercises on three neutrally aligned and three 10° valgus aligned (simulating a medial openwedge high tibial osteotomy - MOWHTO) left human cadaveric knee joints. The knee joints were tested in three states (intact, conventional notchplasty, extended notchplasty) while 11 randomised exercises were simulated (jump landing, squatting, tibial rotation and axial ground impacts at 10°, 30° and 60° knee joint flexion) to investigate the knee joint and implant kinematics by means of rigidly attached reflective marker sets and an according motion analysis.

RESULTS

The maximum implant translation relative to the tibial plateau was < 13 mm and the maximum implant rotation was < 19° for all exercises. Both, the notchplasties and the valgus knee alignment did not affect the device kinematics.

CONCLUSIONS

The results of the present in-vitro study showed that the non-anchored free-floating device remains within the medial knee joint gap under challenging dynamic loading situations without indicating any luxation tendencies. This also provides initial benchtop evidence that the device offers suitable stability and kinematic behaviour to be considered a potential alternative to meniscus allograft transplantation in combination with an MOWHTO, potentially expanding the patient collective in the future.

Primary Fixation and Cyclic Performance of Single-Stitch All-Inside and Inside-Out Meniscal Devices for Repairing Vertical Longitudinal Meniscal Tears

BACKGROUND

Primary device fixation and the resistance against gap formation during repetitive loading influence the quality of meniscal repair. There are limited biomechanical data comparing primary tensioning and cyclic behavior of all-inside versus inside-out repair.

HYPOTHESIS

All-inside devices provide higher initial load on the meniscal repair than inside-out fixation, and stiffer constructs show higher resistance against gap formation during cyclic loading.

STUDY DESIGN

Controlled laboratory study.

METHODS

In total, 60 longitudinal bucket-handle tears in human cadaveric menisci were created and repaired with a single stitch and randomly assigned to 4 all-inside groups (TrueSpan, FastFix 360, Stryker AIR, FiberStich) and 2 inside-out groups (suture repair [IO-S], suture tape [IO-ST]). Residual load after repair tensioning (50 N) and relief displacement were measured. Constructs underwent cyclic loading between 2 and 20 N over 500 cycles (0.75 Hz) with cyclic stiffness, gap formation, and final peak elongation measured. Ultimate load and stiffness were analyzed during pull to failure (3.15 mm/s).

RESULTS

All-inside repair demonstrated significantly higher primary fixation strength than inside-out repair. The significantly highest load (mean ± SD; 20.1 ± 0.9 N; P < .037) and relief displacement (-2.40 ± 0.32 mm; P < .03) were for the knotless soft anchoring FiberStich group. The lowest initial load (9.0 ± 1.5 N; P < .001) and relief displacement (-1.39 ± 0.26 mm; P < .045) were for the IO-S repair group. The final gap formation (500th cycle) of FiberStich (0.75 ± 0.37 mm; P < .02) was significantly smaller than others and that of the IO-S (1.47 ± 0.33 mm; P < .045) significantly larger. The construct stiffness of the FiberStich and IO-ST groups was significantly greater at the end of cyclic testing (16.7 ± 0.80 and 15.5 ± 1.42 N/mm; P < .042, respectively) and ultimate failure testing (23.4 ± 3.6 and 20.6 ± 2.3 N/mm; P < .005). The FastFix 360 (86.4 ± 4.8 N) and Stryker AIR (84.4 ± 4.6 N) groups failed at a significantly lower load than the IO-S group (P < .02) with loss of anchor support. The FiberStich (146.8 ± 23.4 N), TrueSpan (142.0 ± 17.8 N), and IO-ST (139.4 ± 7.3 N) groups failed at significantly higher loads (P < .02) due to suture tearing.

CONCLUSION

Overall, primary fixation strength of inside-out meniscal repair was significantly lower than all-inside repair in this cadaveric tissue model. Although absolute differences among groups were small, meniscal repairs with higher construct stiffness (IO-ST, FiberStich) demonstrated increased resistance against gap formation and failure load.

CLINICAL RELEVANCE

Knotless single-stitch all-inside meniscal repair with a soft anchor resulted in less gapping, but the overall clinical significance on healing rates remains unclear.

Efficacy of Electromyographic Biofeedback in Muscle Recovery after Meniscectomy in Soccer Players

Electromyographic biofeedback (EMG-BF) is a therapeutic technique that has been used successfully in the rehabilitation of injuries. Although it has been applied to athletes, its use in this field is not very widespread. The objective of this study is to analyze its effectiveness in the recovery of electromyographic activity of the quadriceps after meniscectomy, evaluated through isometric contraction of the vastus lateralis. The sample comprised ten professional footballers in the Spanish League (2nd Division A) who had previously suffered a meniscus injury in their knee and had undergone a meniscectomy. The intervention consisted of EMG-BF treatment lasting between 6 and 10 sessions. The electromyographic signal was recorded using a Thought Technology ProComp Infiniti 8-channel biofeedback unit with a sampling rate of 2048 samples/second. For each session, a within-subject ABA design of 6 or 10 trials per session was used, with three pre- and three post-measures, which determined the gain for each session. The results indicated (1) improvements in all cases, (2) EMG-BF was effective, (3) the working model was statistically significant with an explained variance of between 67% and 75%, and (4) the generalizability analysis showed that the results are reliable and generalizable. The results indicate that EMG-BF is effective in neuromuscular rehabilitation after this type of intervention.

Sports Participation and Performance 5 Years After Arthroscopic Partial Meniscectomy: A Retrospective Cohort Study of 288 Patients

OBJECTIVE

To investigate return to sport (RTS) approximately 5 years after arthroscopic partial meniscectomy (APM).

DESIGN

Retrospective cohort study.

METHODS

Knee Arthroscopy Cohort Southern Denmark patients were asked about RTS and reasons for non-RTS approximately 5 years (range, 4-6 years) after APM using online questionnaires. Patients engaged in their sport at the pre-injury level at follow-up were classified as "RTS" (or "returned to sport") and as being engaged in their sport with (1) full participation and performance, (2) reduced performance, or (3) both reduced participation and performance. Self-reported knee function was assessed using the Knee injury and Osteoarthritis Outcome Score (KOOS).

RESULTS

We included 288 patients (mean ± SD age, 49 ± 12 years; 44% women). Of these, 172 patients (60%; 95% confidence interval, 54%-65%) were classified as returned to sport, but only 42% (72/172) reported full participation and performance. Persistent problems with the operated knee were reported by 60% of the patients as the main reason for reduced participation or performance and by 70% of the patients as the main reason for not returning to pre-injury levels of their sport. Patients who had returned to sport, on average, improved by 10.1 points (95% confidence interval, 5.7-14.4) more in KOOS4 scores from baseline to 5 years than non-RTS patients.

CONCLUSION

At approximately 5 years after APM, 6 in every 10 patients had returned to their sport at pre-injury levels, but only 1 in every 4 returned with full participation and performance, mainly due to persistent knee problems. Greater improvements in KOOS scores were observed in patients who were classified as returned to sport. J Orthop Sports Phys Ther 2022;52(4):224-232. doi:10.2519/jospt.2022.10785.

Better Outcomes but No Difference in Joint Space Narrowing at Five Years Among Patients Without Unstable Chondral Lesions Versus Those With Unstable Chondral Lesions (Left In Situ) at the Time of Arthroscopic Partial Meniscectomy

PURPOSE

To compare 5-year outcomes among patients with and without unstable chondral lesions undergoing arthroscopic partial meniscectomy (APM).

METHODS

Using data from the Chondral Lesions And Meniscal Procedures (ChAMP) Trial, we compared outcomes for patients with unstable chondral lesions found at the time of APM and left in situ (CL-noDeb, N = 71) versus patients without unstable chondral lesions (NoCL, N = 47) at 5 years after APM. Outcomes included the Western Ontario and McMaster Universities Arthritis Index (WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS), visual analog pain scale, Short-form Health Survey (SF-36), physical knee measurements, progressive joint space narrowing on radiographs, and the rate of additional knee surgery. Multivariate linear regression was used to obtain mean differences (MDs) with corresponding 95% confidence intervals (CIs) adjusted for age, body mass index, and preoperative score (for postoperative scores).

RESULTS

Compared with CL-noDeb, NoCL subjects had significantly greater improvement at 5 years in the KOOS score for function in sport and recreation (MD = 9.9 [95% CI, 0.7-19.1]), SF-36 pain (MD = 13.9 [95% CI, 5.5-22.3]), knee extension (MD = 0.8 [95% CI, 0.1-1.5]), and decreased quadriceps circumference at the mid-portion of the patella (MD = -1.5 [95% CI, -2.7 to -0.3). A greater proportion of patients in the NoCL group achieved the MCID for all outcome scores except for the WOMAC pain score (89% CL-NoDeb vs 87% NoCL) and SF-36 general (29% CL-NoDeb vs 23% NoCL). There were no significant group differences in measures of progressive radiographic joint space narrowing in any compartments of the operative knee and no significant difference in the rate of additional knee surgery within 5 years of the initial APM.

CONCLUSIONS

Patients undergoing APM without unstable chondral lesions had statistically significantly better outcomes than patients with unstable chondral lesions at 5 years after surgery; however, there were no group differences in progressive radiographic joint space narrowing.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Predictors of Disparities in Patient-Reported Outcomes before and after Arthroscopic Meniscectomy

The purpose of this study is to identify predictors of disparities in patient-reported outcome measures (PROMs) before and after arthroscopic meniscectomy. Knee injury and Osteoarthritis Outcome Score (KOOS) was used in this study. All patients who underwent single-knee arthroscopic meniscectomy from January 2012 to March 2018 performed by a single surgeon at an academic safety-net hospital were identified. We excluded patients who had undergone ipsilateral previous knee surgery, bilateral meniscectomy, or concomitant ligament, cartilage, or osteotomy procedures, and those with severe radiographic osteoarthritis in the operated knee, missing preoperative data, or military insurance. Data abstracted from medical records included demographics (age, sex, race, insurance type), clinical characteristics (body mass index, Charlson comorbidity index, and Kellgren-Lawrence [KL] grade), procedure codes, and KOOS assessed before and 90 days after surgery. Multivariable analyses investigated the associations between patient characteristics and the KOOS Pain, other Symptoms, and Function in activities of daily living (ADL) subscales. Among 251 eligible patients, most were female (65.5%), half were of nonwhite race (50.2%), and almost one third were insured by Medicaid (28.6%). Medicaid and black race were statistically significant (p < 0.05) predictors of worse preoperative values for all three KOOS subscales. Medicaid insurance also predicted a lower likelihood of successful surgery, defined as meeting the 10-point minimal clinically important difference, for the KOOS symptoms (p < 0.05) and KOOS ADL (p < 0.05) subscales. Compared with patients without definitive evidence of radiographic osteoarthrosis (KL grade 1), those with moderate radiographic osteoarthritis (KL grade 3) were less likely to have a successful surgical outcome (p < 0.05 for all subscales). Worse preoperative KOOS values predicted worse postoperative KOOS values (p < 0.001 for all subscales) and a lower likelihood of surgical success (p < 0.01 for all subscales). Insurance-based disparities in access to orthopaedic care for meniscus tears may explain worse preoperative PROMs and lower success rates of meniscectomy among Medicaid patients. Patients with meniscus tears and radiological and/or magnetic resonance imaging evidence of osteoarthritis should be carefully evaluated to determine the appropriateness of arthroscopic meniscectomy.

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.

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.

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.

Radiographic Prognostic Factors Relevant to Surgical Outcomes of Arthroscopic Partial Medial Meniscectomy in Elderly Patients with Mild Osteoarthritis

The aim of this study was to investigate radiographic factors relevant to predict surgical outcomes of arthroscopic partial meniscectomy (APM) in elderly patients with mild osteoarthritis (Kellgren-Lawrence grades 1 and 2). Data of 172 consecutive patients aged >70 years who underwent arthroscopic meniscal surgery were reviewed retrospectively. The patients who met the inclusion criteria were classified into two groups based on the minimal clinically important difference value of the Lysholm knee scoring scale comparing the score of the last visit with that of the preoperative period: group 1 (with clinically significant improvement) and group 2 (without clinically important change). Radiographic factors assessed on X-ray and magnetic resonance images were evaluated using bivariate and logistic regression analyses. A total of 73 patients were included in this study. Bivariate analysis revealed that the extent of meniscus extrusion (p = 0.031), meniscus extrusion ratio (p = 0.001), and grade of meniscus degeneration (p = 0.019) were significantly different between the groups. Multivariate logistic regression analysis showed that the meniscus extrusion ratio was the most important independent predictive factor for surgical outcomes with clinically important changes (coefficient = 0.159, p = 0.009). On receiver operating characteristic (ROC) curve analysis, the cutoff point of the meniscus extrusion ratio discriminating the two groups was 34.2% (sensitivity: 79.3%; specificity: 68.6%; accuracy: 72.6%). Meniscus extrusion ratio was the most relevant predictive factor for discriminating patients with clinically important change. Meniscus extrusion ratio, with the cutoff point of 34.2%, could serve as a guide to determine whether to perform APM in elderly patients with mild osteoarthritis. This is a Level IV, therapeutic case series study.

Observation Versus Debridement of Unstable Chondral Lesions During Partial Meniscectomy: Analysis of Patient Outcomes and Degenerative Joint Disease at 5 Years in the Chondral Lesions And Meniscus Procedures (ChAMP) Randomized Controlled Trial

BACKGROUND

The purpose of this study was to examine the effect of debridement (CL-Deb) versus observation (CL-noDeb) of unstable chondral lesions on knee pain 5 years after arthroscopic partial meniscectomy (APM) in patients enrolled in the Chondral Lesions And Meniscus Procedures (ChAMP) Trial. Secondarily, other knee symptoms, function, general health, and the rate of additional surgery on the affected knee were examined.

METHODS

Patients aged ≥30 years who had an unstable Outerbridge grade-II, III, or IV chondral lesion when undergoing APM were randomly allocated to the CL-Deb (n = 98) or CL-noDeb (n = 92) group; ∼80% in each group completed a 5-year follow-up. Outcomes were measured preoperatively and at 5 years postoperatively, and included the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee injury and Osteoarthritis Outcome Score (KOOS), visual analog scale (VAS) for pain, Short Form-36 (SF-36), physical knee measurements, knee radiographs, and rate of additional knee surgery at 5 years. The primary outcome was the 5-year WOMAC pain score. Group comparisons were made using the t test for continuous outcomes and the Fisher exact test for categorical outcomes.

RESULTS

There were no significant differences between the groups with respect to the primary outcome, the WOMAC pain score (CL-Deb: 86.0 [95% confidence interval (CI): 82.9 to 89.1]) versus CL-noDeb: 88.3 [95% CI: 85.5 to 91.1]; p = 0.27), or secondary outcomes at 5 years. There were also no differences in radiographic measurements of joint-space narrowing in any compartment (medial or lateral tibiofemoral or medial, central, or lateral patellofemoral) as well as no difference in the rate of additional knee surgery within 5 years after APM between the CL-Deb and CL-noDeb groups.

CONCLUSIONS

Outcomes for the CL-Deb and CL-noDeb groups did not differ at 5 years postoperatively, suggesting that there is no long-term benefit of arthroscopic debridement of chondral lesions encountered during APM.

LEVEL OF EVIDENCE

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

Publicly Available Rehabilitation Protocols Designated for Meniscal Repairs Are Highly Variable

Purpose

To compare publicly available rehabilitation protocols designated for meniscal repairs published online to determine the variability in meniscus repair protocols including different types of tears (radial vs nonradial repairs).

Methods

From the Fellowship and Residency Electronic Interactive Database Access System (FREIDA), a list of publicly available academic residency programs and orthopaedic sports medicine fellowships was obtained. With this list, an electronic search using Google was performed looking for meniscal repair rehabilitation protocols. In addition to academic institutions, private practice organizations with published meniscus repair rehabilitation protocols found during the search also were examined.

Results

Of 189 academic institutions, a total of 30 academic institutions had protocols that were included. Another 29 private practice programs were subsequently found and included. In total, 59 rehabilitation protocols fit the inclusion criteria. Six of the 59 specified radial repair and 53 did not. For return to full range of motion, nonradial protocols averaged 6.7 weeks and radial protocols averaged 7.3 weeks. For return to full weight-bearing, nonradial protocols averaged 6.2 weeks and radial protocols averaged 7.5 weeks. For return to sport, nonradial protocols averaged 17.8 weeks and radial protocols averaged 23.3 weeks. For time spent in a brace, nonradial protocols averaged 5.7 weeks and radial protocols averaged 6.7 weeks.

Conclusions

Of publicly available meniscal repair rehabilitation protocols, a small percentage (10.2%) changed their protocol in relation to tear type and there was a wide range of timeframes for each rehabilitation component. Protocols for radial tears tended to brace patients longer, limit their range of motion longer, delay full weight-bearing, and delay return to sport. However, it is recognized that some surgeons could be modifying their protocols in relation to tear type without publishing that information online.

Clinical Relevance

As stated in the purpose, the point of this study was to access only the protocols that would be available to the public. If anything, awareness should be raised for surgeons to look at their existing protocols and update them if they are truly incomplete and outdated. More research needs to be done to structure a rehabilitation protocol that is specific to the meniscal tear type, as the current protocols have a wide range of variance.

Time to Achievement of Clinically Significant Outcomes After Isolated Arthroscopic Partial Meniscectomy: A Multivariate Analysis

Purpose

To define the time required to achieve the minimally clinically important difference (MCID), substantial clinical benefit (SCB) and patient acceptable symptomatic state (PASS) for isolated arthroscopic partial meniscectomy (APM), and define preoperative and intraoperative factors that predict both early and late achievement of the stated metrics.

Methods

Patients who underwent isolated APM between 2014 and 2017 were retrospectively included. Patients without preoperative and 6-month patient-reported outcome measure scores, revision procedures, and significant concomitant procedures were excluded. The MCID, SCB, and PASS were calculated for knee-based patient-reported outcome measure scores using receiver operating curve analysis. Kaplan-Meier survival analysis established the time required to achieve MCID, SCB and PASS. Hazard ratios from multivariate Cox regression allowed for the isolation of demographic and intraoperative factors predictive of the delayed time required to achieve MCID, SCB and PASS.

Results

A total of 126 patients (42.86% female, age: 48.9 ± 12.4 years) were included. Overall achievement rates ranged between 73.0% and 89.7% for MCID, 43.7% and 68.2% for SCB, and 50.8% and 68.3% for PASS. Median achievement time for MCID was 5.68-5.78 months, 5.73-6.05 months for SCB and 6.54-7.72 months for PASS. Multivariate Cox regression identified older age, workers' compensation status, diabetes, and various tear types (i.e., longitudinal, transverse, bucket handle, complex) as predictors of early clinically significant outcome achievement (hazard ratio: 1.02-24.72), whereas subsequent steroid injection, higher preoperative scores and root and flap tears predicted delays in clinically significant outcome achievement (hazard ratio: 0.12-0.99).

Conclusions

The majority of patients undergoing APM achieve benefit within 6 months of surgery, with diminishing proportions at later timepoints. Important factors for consideration of the the timeline of achieving clinically significant outcome include age, diabetes, workers' compensation, preoperative score, and tear type. The timeline for achieving improvement that was established by this study may aid in setting patient expectations and designing future outcome studies involving APM.

Study design

Level IV, Therapeutic Case Series.

Degeneration alters the biomechanical properties and structural composition of lateral human menisci

OBJECTIVE

Because the literature relating to the influence of degeneration on the viscoelasticity and tissue composition of human lateral menisci remains contradictory or completely lacking, the aim of this study was to fill these gaps by comprehensively characterising the biomechanical properties of menisci with regard to the degree of degeneration.

DESIGN

Meniscal tissue from 24 patients undergoing a total knee replacement was collected and the degeneration of each region classified according to Pauli et al. For biomechanical characterisation, compression and tensile tests were performed. Additionally, the water content was determined and infrared (IR) spectroscopy was applied to detect changes in the structural composition, particularly of the proteoglycan and collagen content.

RESULTS

With an increasing degree of degeneration, a significant decrease of the equilibrium modulus was detected, while simultaneously the water content and the hydraulic permeability significantly increased. However, the tensile modulus displayed a tendency to decrease with increasing degeneration, which might be due to the significantly decreasing amount of collagen content identified by the IR measurements.

CONCLUSION

The findings of the current study may contribute to the understanding of meniscus degeneration, showing that degenerative processes appear to mainly worsen viscoelastic properties of the inner circumference by disrupting the collagen integrity.

Meniscus tears accelerate joint space loss and lateral meniscal extrusion increases risk of knee arthroplasty in middle-aged adults

We sought to use publicly available data from the Osteoarthritis Initiative (OAI), a multicenter prospective cohort study, to determine the rate of joint space loss and likelihood of knee arthroplasty due to magnetic resonance imaging (MRI)-diagnosed meniscal tears or meniscal extrusion in middle-aged adults with no to mild knee osteoarthritis. Participants (n = 2199; mean age, 60.2 years) with Kellgren-Lawrence osteoarthritis grades 2 (mild) (48.7%) or 0 to 1 (none) (51.3%) underwent knee MRIs at enrollment and were followed radiographically for 8 years and for total knee arthroplasty (TKA) for 9 years. Rate of joint space loss and risk of arthroplasty due to meniscal tears and/or extrusion were determined by multivariate modeling. Prevalence of baseline medial meniscus tears was 21.3% and lateral tears was 12.8%; 26.9% had medial meniscal extrusion (79.6%, <2 mm; 20.4%, +2 mm) and 5.4% had lateral extrusion (75.9%, <2 mm; 24.1%, +2 mm). Median medial joint space loss was 0.06 mm/y and lateral was 0.05 mm/y. Medial tears regardless of extrusion were associated with accelerated medial joint space loss (additional mean, 0.05 mm/y; P = .001). Lateral tears were associated with accelerated lateral joint space loss (additional 0.09 mm/y; P < .001) as was lateral extrusion (additional 0.10 mm/y; P < .001). The yearly incidence of knee arthroplasty was 0.5% without lateral extrusion, 1.5% with extrusion less than 2.0 mm, and 3.7% with extrusion greater than or equal to 2.0 mm. Both medial and lateral tears accelerate joint space loss in middle-aged adults. Lateral meniscal extrusion further accelerates joint space loss and increases risk of progression to TKA within 9 years.

Cartilage Restoration Using Dehydrated Allogeneic Cartilage, Platelet-Rich Plasma, and Autologous Cartilage Mixture Sealed With Activated Autologous Serum

Articular cartilage injury is a common source of knee pain and dysfunction. Patients in whom conservative treatment fails may benefit from surgical intervention to restore function and alleviate pain. Autologous cartilage procedures are a viable treatment modality for cartilage repair, providing comparable outcomes to osteochondral allografts while leaving the subchondral bone intact. This article discusses the senior author's method of cartilage restoration using BioCartilage (Arthrex, Naples, FL), platelet-rich plasma, and autologous cartilage collected using a designated collection device sealed with activated autologous serum.

Reducing the Volume of Low-Value Outpatient MRI Joint Examinations in Patients ≥55 Years of Age

Purpose:

Magnetic resonance imaging (MRI) is not beneficial in patients with joint pain and concomitant osteoarthritis (OA). We attempt to determine whether evaluation of OA via X-rays can reduce inappropriate MRI and computed tomography (CT) arthrogram use. In our jurisdiction, CT arthrograms are used as surrogate tests because of MRI wait times.

Materials and Methods:

Our intervention required patients ≥55 years of age scheduled for outpatient MRI of the knee/hip/shoulder at an urban hospital to have X-rays (weight bearing when appropriate) from within 1 year. Red flags (ie, neoplasm, infection) were identified for which MRI would be indicated regardless. Through review of radiographs on picture archiving and communication system/digital media and use of the validated Kellgren-Lawrence (KL) OA scale, radiologists assessed the presence and degree of OA. A finding of significant OA (KL > 2) without red flags would preclude MRI. Monthly averages of MRI and CT arthrogram examinations were measured 33 months before and 23 months following introduction of the intervention.

Results:

The proportion of protocoled MRI requisitions that were avoided was 21%. If extrapolated to the province of British Columbia, 2419 of 11 700 examinations could have been prevented in the past year. The average monthly number of knee/hip/shoulder MRI examinations as a percentage of total MRI examinations decreased from 4.9% to 4.3% ( P < .02) following the intervention. The average monthly number of knee/hip/shoulder CT arthrogram examinations decreased from 20.6 to 12.1 ( P < .0001).

Conclusion:

We were able to decrease the number of MRI and CT arthrogram examinations in patients ≥55 years of age with joint pain by implementing an evaluation for OA via recent X-ray imaging.

Surgical interventions for symptomatic mild to moderate knee osteoarthritis

BACKGROUND

Osteoarthritis affecting the knee is common and represents a continuum of disease from early cartilage thinning to full-thickness cartilage loss, bony erosion, and deformity. Many studies do not stratify their results based on the severity of the disease at baseline or recruitment.

OBJECTIVES

To assess the benefits and harms of surgical intervention for the management of symptomatic mild to moderate knee osteoarthritis defined as knee pain and radiographic evidence of non-end stage osteoarthritis (Kellgren-Lawrence grade 1, 2, 3 or equivalent on MRI/arthroscopy). Outcomes of interest included pain, function, radiographic progression, quality of life, short-term serious adverse events, re-operation rates and withdrawals due to adverse events.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase up to May 2018. We also conducted searches of ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform for ongoing trials. Authors of trials were contacted if some but not all their participants appeared to fit our inclusion criteria.

SELECTION CRITERIA

We included randomised controlled trials that compared surgery to non-surgical interventions (including sham and placebo control groups, exercise or physiotherapy, and analgesic or other medication), injectable therapies, and trials that compared one type of surgical intervention to another surgical intervention in people with symptomatic mild to moderate knee osteoarthritis.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials and extracted data using standardised forms. We analysed the quality of evidence using the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach.

MAIN RESULTS

A total of five studies involving 566 participants were identified as eligible for this review. Single studies compared arthroscopic partial meniscectomy to physical therapy (320 participants), arthroscopic surgery (debridement ± synovectomy ± chondroplasty) to closed needle joint lavage with saline (32 participants) and high tibial osteotomy surgery to knee joint distraction surgery (62 participants). Two studies (152 participants) compared arthroscopic surgery (washout ± debridement; debridement) to a hyaluronic acid injection. Only one study was at low risk of selection bias, and due to the difficulty of blinding participants to their treatment, all studies were at risk of performance and detection bias.Reporting of results in this summary has been restricted to the primary comparison: surgical intervention versus non-surgical intervention.A single study, included 320 participants with symptoms consistent with meniscal tear. All subjects had the meniscal tear confirmed on knee MRI and radiographic evidence of mild to moderate osteoarthritis (osteophytes, cartilage defect or joint space narrowing). Patients with severe osteoarthritis (KL grade 4) were excluded. The study compared arthroscopic partial meniscectomy and physical therapy to physical therapy alone (a six-week individualised progressive home exercise program). This study was at low risk of selection bias and outcome reporting biases, but was susceptible to performance and detection biases. A high rate of cross-over (30.2%) occurred from the physical therapy group to the arthroscopic group.Low-quality evidence suggests there may be little difference in pain and function at 12 months follow-up in people who have arthroscopic partial meniscectomy and those who have physical therapy. Evidence was downgraded to low quality due to risk of bias and imprecision.Mean pain was 19.3 points on a 0 to 100 point KOOS pain scale with physical therapy at 12 months follow-up and was 0.2 points better with surgery (95% confidence interval (CI) 4.05 better to 3.65 points worse with surgery, an absolute improvement of 0.2% (95% CI 4% better to 4% worse) and relative improvement 0.4% (95% CI 9% better to 8% worse) (low quality evidence). Mean function was 14.5 on a 0 to 100 point KOOS function scale with physical therapy at 12 months follow-up and 0.8 points better with surgery (95% CI 4.3 better to 2.7 worse); 0.8% absolute improvement (95% CI 4% better to 3% worse) and 2.1% relative improvement (95% CI 11% better to 7% worse) (low quality evidence).Radiographic structural osteoarthritis progression and quality of life outcomes were not reported.Due to very low quality evidence, we are uncertain if surgery is associated with an increased risk of serious adverse events, incidence of total knee replacement or withdrawal rates. Evidence was downgraded twice due to very low event rates, and once for risk of bias.At 12 months, the surgery group had a total of three serious adverse events including fatal pulmonary embolism, myocardial infarction and hypoxaemia. The physical therapy alone group had two serious adverse events including sudden death and stroke (Peto OR 1.58, 95% CI 0.27 to 9.21); 1% more events with surgery (95% CI 2% less to 3% more) and 58% relative change (95% CI 73% less to 821% more). One participant in each group withdrew due to adverse events.Two of 164 participants (1.2%) in the physical therapy group and three of 156 in the surgery group underwent conversion to total knee replacement within 12 months (Peto OR 1.76, 95% CI 0.43 to 7.13); 1% more events with surgery (95% CI 2% less to 5% more); 76% relative change (95% CI 57% less to 613% more).

AUTHORS' CONCLUSIONS

The review found no placebo-or sham-controlled trials of surgery in participants with symptomatic mild to moderate knee osteoarthritis. There was low quality evidence that there may be no evidence of a difference between arthroscopic partial meniscectomy surgery and a home exercise program for the treatment of this condition. Similarly, low-quality evidence from a few small trials indicates there may not be any benefit of arthroscopic surgery over other non-surgical treatments including saline irrigation and hyaluronic acid injection, or one type of surgery over another. We are uncertain of the risk of adverse events or of progressing to total knee replacement due to very small event rates. Thus, there is uncertainty around the current evidence to support or oppose the use of surgery in mild to moderate knee osteoarthritis. As no benefit has been demonstrated from the low quality trials included in this review, it is possible that future higher quality trials for these surgical interventions may not contradict these results.

Design and biomechanical characteristics of porous meniscal implant structures using triply periodic minimal surfaces

BACKGROUND

Artificial meniscal implants can be used to replace a severely injured meniscus after meniscectomy and restore the normal functionality of a knee joint. The aim of this paper was to design porous meniscal implants and assess their biomechanical properties.

METHODS

Finite element simulations were conducted on eight different cases including intact healthy knees, knee joints with solid meniscal implants, and knee joints with meniscal implants with two types of triply periodic minimal surfaces. Compression stresses, shear stresses, and characteristics of stress concentrated areas were evaluated using an axial compressive load of 1150 N and an anterior load of 350 N.

RESULTS

Compared to the solid meniscal implant, the proposed porous meniscal implant produced lower levels of compression and shear stresses on the cartilage, which facilitated the cartilage to retain a semilunar characteristic similar to the natural meniscus. Moreover, both compression and shear stresses on the artificial cartilage were found to be sensitive to the pore properties of the meniscal implant. The meniscal implants with primitive surfaces (porosity: 41%) showed a better performance in disseminating stresses within the knee joint.

CONCLUSION

The present commercial meniscal implant has the problem of equivalent biomechanical properties compared to natural menisci. The main advantage of the proposed porous structure is that it can be used to prevent excessive compression and shear stresses on the articular cartilages. This structure has advantages both in terms of mechanics and printability, which can be beneficial for future clinical applications.

Temporary postoperative treatment with compartment-unloading knee braces or wedge insoles does not improve clinical outcome after partial meniscectomy

PURPOSE

To investigate whether temporary postoperative compartment-unloading therapy after arthroscopic partial meniscectomy (APM)-with either knee braces or wedge insoles-leads to superior clinical outcome as compared to controls. This difference in clinical outcome was tested in the form of two knee scores, physical activity and general health outcome over the first postoperative year.

METHODS

Sixty-three patients who underwent arthroscopic partial meniscectomy (APM) were randomized to one of the following three groups: 12 weeks postoperative knee compartment-unloading therapy with either a knee brace (brace group) or wedge insoles (insole group) or no specific postoperative therapy (control group). Patient-reported outcome was assessed with the International Knee Documentation Committee Subjective Knee Evaluation Form (IKDC Score), the Knee Injury and Osteoarthritis Outcome Score (KOOS), the MARX score (physical activity) and the SF-12 (general health).

RESULTS

Sixty-three patients were available for analysis. Except for the SF-12 mental score, all other scores showed significant improvement over time. With regard to the hypotheses proposed, no significant group * time interactions were observed for any of the outcome parameters. This means that the group (i.e. the type of postoperative treatment) was not related to the degree of improvement of any of the scores.

CONCLUSIONS

It was concluded that 12 weeks of compartment-unloading therapy-with either a knee brace or wedge insoles-is ineffective with regard to clinical outcome after APM. This applies to the knee score outcome, physical activity and general health outcome over the first year following APM.

LEVEL OF EVIDENCE

Randomized controlled trial, Level I.

Long-term outcome after all inside meniscal repair using the FasT-Fix system

Purpose

Meniscal surgery is one of the most performed orthopaedic procedures. Because of its chondroprotective properties, meniscal repair should be attempted whenever possible. Several techniques are described in literature, e.g. all-inside repair using FasT-Fix System from Smith & Nephew. The aim of this study was to evaluate the outcome at a minimum of 12 years following meniscal repair using FasT-Fix System.

Materials and Methods

Patients who underwent meniscal repair using FasT-Fix System in the time from 2001 to 2003 were analyzed. We included isolated meniscal tears and combined tears with a concomitant ACL rupture. A median 12-year follow-up was conducted in 2015. Failure was defined as a new surgical procedure to the same meniscus. Moreover, functional outcome was evaluated using the KOOS and tegner activity score (TAS).

Results

At follow-up 27% had undergone further surgery to the repaired meniscus. There was no significant difference between isolated and combined group (p = 0.582). The failure rate was significantly higher in females (female 48% versus male 15%; p = 0.005). Comparing sports there was a significantly higher failure rate within soccer and indoor sports group (p = 0.002).Comparing isolated and combined injury groups there was no difference in the TAS (p > 0.05). Only 1 item of KOOS showed no significant difference: 95.33 versus 94.48 for daily life activities (p > 0.05). The other items showed significant differences.49 out of 51 patients with combined injuries suffered an additional ACL rupture. There was no significant difference regarding the meniscal repair failure rate when comparing the groups of simultaneous and delayed ACL repair (p = 0.521).

Conclusions

At 12 years' follow-up 73% had a successful surgery. KOOS was significantly better within isolated meniscus tears. Both groups showed no difference in the TAS. There were no differences regarding failure rate in the comparison of simultaneous or delayed ACL-reconstruction.

Rehabilitation following meniscal repair: a systematic review

Objective

To review existing biomechanical and clinical evidence regarding postoperative weight-bearing and range of motion restrictions for patients following meniscal repair surgery.

Methods and data sources

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline, we searched MEDLINE using following search strategy: ((((“Weight-Bearing/physiology”[Mesh]) OR “Range of Motion, Articular”[Mesh]) OR “Rehabilitation”[Mesh])) AND (“Menisci, Tibial”[Mesh]). Additional articles were derived from previous reviews. Eligible studies were published in English and reported a rehabilitation protocol following meniscal repair on human. We summarised rehabilitation protocols and patients’ outcome among original studies.

Results

Seventeen clinical studies were included in this systematic review. There was wide variation in rehabilitation protocols among clinical studies. Biomechanical evidence from small cadaveric studies suggests that higher degrees of knee flexion and weight-bearing may be safe following meniscal repair and may not compromise the repair. An accelerated protocol with immediate weight-bearing at tolerance and early motion to non-weight-bearing with immobilising up to 6 weeks postoperatively is reported. Accelerated rehabilitation protocols are not associated with higher failure rates following meniscal repair.

Conclusions

There is a lack of consensus regarding the optimal postoperative protocol following meniscal repair. Small clinical studies support rehabilitation protocols that allow early motion. Additional studies are needed to better clarify the interplay between tear type, repair method and optimal rehabilitation protocol.

Mechanical viability of a thermoplastic elastomer hydrogel as a soft tissue replacement material

Hydrogels are a class of synthetic biomaterials composed of a polymer network that swells with water and as such they have both an elastic and viscous component making them ideal for soft tissue applications. This study characterizes the compressive, tensile, and shear properties of a thermoplastic elastomer (TPE) hydrogel and compares the results to published literature values for soft tissues such as articular cartilage, the knee meniscus, and intervertebral disc components. The results show the TPE hydrogel material is viscoelastic, strain rate dependent, has similar surface and bulk properties, displays minimal damping under dynamic load, and has tension-compression asymmetry. When compared to other soft tissues it has a comparable equilibrium compressive modulus of approximately 0.5MPa and shear modulus of 0.2MPa. With a tensile modulus of only 0.2MPa though, the TPE hydrogel is inferior in tension to most collagen based soft tissues. Additional steps may be necessary to reinforce the hydrogel system and increase tensile modulus depending on the desired soft tissue application. It can be concluded that this material could be a viable option for soft tissue replacements.

The Utility of Biologics, Osteotomy, and Cartilage Restoration in the Knee

The management of complex cartilage and meniscal pathology in young, athletic patients is extremely challenging. Joint preservation surgery is most difficult in patients with concomitant knee pathologies, including cartilage defects, meniscal deficiency, malalignment, and/or ligamentous insufficiency. Clinical decision making for these patients is further complicated by articular cartilage lesions, which often are incidental findings; therefore, treatment decisions must be based on the confirmed contribution of articular cartilage lesions to symptomatology. Surgical management of any of the aforementioned knee pathologies that is performed in isolation typically results in acceptable patient outcomes; however, concomitant procedures for the management of concomitant knee pathologies often are essential to the success of any single procedure. The use of biologic therapy as an alternative to or to augment more conventional surgical management has increased in popularity in the past decade, and indications for biologic therapy continue to evolve. Orthopaedic surgeons should understand knee joint preservation techniques, including biologic and reconstructive approaches in young, high-demand patients.

Knee Extensor Rate of Torque Development Before and After Arthroscopic Partial Meniscectomy, With Analysis of Neuromuscular Mechanisms

Study Design Descriptive, prospective single-cohort longitudinal study. Background Though rapid torque development is essential in activities of daily living and sports, it hasn't been specifically tested by most physical therapists or incorporated into rehabilitation programs until late in the treatment process. Little evidence is available on quadriceps torque development capacity before and after arthroscopic knee surgery. Objectives To study knee extensor rate of torque development, contributing mechanisms, and associations with strength and patient-reported outcomes before and during the first 6 weeks after arthroscopic partial meniscectomy. Methods Twenty subjects (mean ± SD age, 42.3 ± 13.7 years; body mass index, 26.6 ± 3.1 kg/m²) were tested before surgery, and at 2 and 5 weeks after surgery. Quadriceps muscle volume, strength, activation, rate of torque development, and patient-reported outcomes were evaluated across the study period. Results Significant side-to-side differences in quadriceps strength and voluntary rate of torque development were observed at each time point (P<.05). Changes in muscle activity were associated with changes in rapid torque development capacity. Side-to-side rate of torque development deficits after surgery were associated with lower patient-reported outcomes scores. Conclusion Diminished rapid torque development capacity is common in arthroscopic meniscal debridement patients. This reduced capacity is associated with an inability to quickly recruit and drive the quadriceps muscles (neural mechanisms) and not muscle atrophy or other peripheral factors tested. Patient-reported outcomes are associated with quadriceps rate of torque development, but not strength or muscle size. Rapid torque development warrants greater attention in rehabilitation. J Orthop Sports Phys Ther 2017;47(12):945-956. Epub 9 Oct 2017. doi:10.2519/jospt.2017.7310.

The origin and distribution of CD68, CD163, and αSMA+ cells in the early phase after meniscal resection in a parabiotic rat model

We previously reported that circulating peripheral blood-borne cells (PBCs) contribute to early-phase meniscal reparative change. Because macrophages and myofibroblasts are important contributors of tissue regeneration, we examined their origin and distribution in the reparative meniscus. Reparative menisci were evaluated at 1, 2, and 4 weeks post-meniscectomy by immunohistochemistry to locate monocytes and macrophages (stained positive for CD68 and CD163), and myofibroblasts (stained positive for αSMA). Of the total number of cells, 13% were CD68⁺ at 1 week post-meniscectomy, which decreased to 1% by 4 weeks post-meniscectomy; of these, almost half of CD68⁺ cells (49.4%: 98.8% as PBCs) were green fluorescent protein (GFP)-positive post-meniscectomy (1, 2, and 4 weeks), indicating that the majority of CD68⁺ cells were derived from PBCs. Of the total cells, 6% were CD163⁺ at 1 week post-meniscectomy, which decreased to 1% by week 4. Of the CD163⁺ cells, the majority were GFP-positive (42.5%: 85.0% as PBCs) after 1 week; however, this decreased significantly over time, which indicates that the majority of CD163⁺ cells are derived from PBCs during the early phase of meniscal reparative change, but are derived from resident cells at later time points. Of the total cells, 38% were αSMA⁺ at 1 week post-meniscectomy, which decreased to 3% by 4 weeks. The proportion of GFP-positive αSMA⁺ cells was 2.8% after 1 week, with no significant change over time, which indicates that the majority of αSMA⁺ cells originated from resident cells. Here, we describe the origin and distribution of macrophages and myofibroblasts during meniscal reparative change.

Dynamic compression of human and ovine meniscal tissue compared with a potential thermoplastic elastomer hydrogel replacement

Understanding how human meniscal tissue responds to loading regimes mimetic of daily life as well as how it compares to larger animal models is critical in the development of a functionally accurate synthetic surrogate. Seven human and eight ovine cadaveric meniscal specimens were regionally sectioned into cylinders 5 mm in diameter and 3 mm thick along with 10 polystyrene-b-polyethylene oxide block copolymer-based thermoplastic elastomer (TPE) hydrogels. Samples were compressed to 12% strain at 1 Hz for 5000 cycles, unloaded for 24 h, and then retested. No differences were found within each group between test one and test two. Human and ovine tissue exhibited no regional dependency (p < 0.05). Human samples relaxed quicker than ovine tissue or the TPE hydrogel with modulus values at cycle 50 not significantly different from cycle 5000. Ovine menisci were found to be similar to human menisci in relaxation profile but had significantly higher modulus values (3.44 MPa instantaneous and 0.61 MPa after 5000 cycles compared with 1.97 and 0.11 MPa found for human tissue) and significantly different power law fit coefficients. The TPE hydrogel had an initial modulus of 0.58 MPa and experienced less than a 20% total relaxation over the 5000. Significant differences in the magnitude of compressive modulus between human and ovine menisci were observed, however the relaxation profiles were similar. Although statistically different than the native tissues, modulus values of the TPE hydrogel material were similar to those of the human and ovine menisci, making it a material worth further investigation for use as a synthetic replacement. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2722-2728, 2017.

Coronal Knee Alignment 40 Years after Total Meniscectomy in Adolescents: A Prospective Cohort Study

INTRODUCTION

Meniscectomies result in altered knee biomechanics and increase contact forces on the operated knee joint.

METHODS

We assessed coronal knee alignment in relation to radiological osteoarthritis grading, clinical range of movement and patient reported outcome measures 40 years after total open meniscectomies in adolescence. Thirty eight knees (30 patients) that underwent total open meniscectomy were assessed on standardised weight-bearing anteroposterior radiographs for deviation from 'physiological valgus angle' in either direction (magnitude of malalignment). These values were analysed as per site of meniscectomy for correlations with radiographic scoring systems, range of motion and patient reported outcome measures.

RESULTS

Tibiofemoral angle was significantly more varus, and the magnitude of malalignment was significantly higher for the medial meniscectomy patients. The range of flexion was lower for those patients who underwent medial and lateral meniscectomies of the same knee. The patients who underwent meniscectomies of both knees had worse scores for IKDC and KOOS quality of life. Tibiofemoral angle, magnitude of malalignment and range of flexion strongly correlated with Ahlback, and Kellgren and Laurence scores, but patient reported that outcome measures did not correlate.

CONCLUSION

Meniscectomy induced malalignment corresponds to the site of meniscectomy and the radiographic degree of osteoarthritis. While malalignment and reduced range of movement correlate well with worsening radiographic signs of arthritis, patient reported outcome measures do not correlate.

Use of pre-clinical surgically induced models to understand biomechanical and biological consequences of PTOA development

Post-traumatic osteoarthritis (PTOA) development is often observed following traumatic knee injuries involving key stabilising structures such as the cruciate ligaments or the menisci. Both biomechanical and biological alterations that follow knee injuries have been implicated in PTOA development, although it has not been possible to differentiate clearly between the two causal factors. This review critically examines the outcomes from pre-clinical lapine and ovine injury models arising in the authors' laboratories and differing in severity of PTOA development and progression. Specifically, we focus on how varying severity of knee injuries influence the subsequent alterations in kinematics, kinetics, and biological outcomes. The immediate impact of injury on the lubrication capacity of the joint is examined in the context of its influence on biomechanical alterations, thus linking the biological changes to abnormal kinematics, leading to a focus on the potential areas for interventions to inhibit or prevent development of the disease. We believe that PTOA results from altered cartilage surface interactions where biological and biomechanical factors intersect, and mitigating acute joint inflammation may be critical to prolonging PTOA development. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:454-465, 2017.

Recovery of lower extremity muscle strength and functional performance in middle-aged patients undergoing arthroscopic partial meniscectomy

PURPOSE

To investigate lower extremity muscle strength and functional performance before and after arthroscopic partial meniscectomy in middle-aged patients with degenerative meniscal tears. We hypothesized that patients would experience deficiencies in the affected leg at 3 months post-surgery, and that this deficiency would be normalized at 12 months following surgery.

METHODS

Twenty-three patients (46 ± 6.5 years) meniscectomized in 2012 and 2013 were examined for knee extension, knee flexion, and hip abduction maximal isometric muscle strength (iMVC), rate of force development (RFD₂₀₀), and knee function (single-leg hop for distance and single-leg knee bends in 30 s.) before surgery, 3 and 12 months after surgery.

RESULTS

Functional performance, knee extension iMVC and RFD₂₀₀ were impaired in the affected leg compared to the contralateral leg (p < 0.05) prior to surgery. A significant (Knee extension RFD₂₀₀, p = 0.033) or borderline significant improvement was observed in the affected leg compared to the contralateral leg from before to 12 months after surgery in most variables (leg × time interaction, n.s.).

CONCLUSION

Middle-aged patients undergoing surgery for degenerative medial meniscal tears show significant reductions in muscle strength, rapid force production, and functional performance in the leg undergoing surgery compared to the contralateral leg prior to surgery. These deficits in muscle strength and knee function were still present at 3 months post-surgery but were no longer observed at 12 months following surgery.

LEVEL OF EVIDENCE

III.

An Overview of Scaffold Design and Fabrication Technology for Engineered Knee Meniscus

Current surgical treatments for meniscal tears suffer from subsequent degeneration of knee joints, limited donor organs and inconsistent post-treatment results. Three clinical scaffolds (Menaflex CMI, Actifit® scaffold and NUsurface® Meniscus Implant) are available on the market, but additional data are needed to properly evaluate their safety and effectiveness. Thus, many scaffold-based research activities have been done to develop new materials, structures and fabrication technologies to mimic native meniscus for cell attachment and subsequent tissue development, and restore functionalities of injured meniscus for long-term effects. This study begins with a synopsis of relevant structural features of meniscus and goes on to describe the critical considerations. Promising advances made in the field of meniscal scaffolding technology, in terms of biocompatible materials, fabrication methods, structure design and their impact on mechanical and biological properties are discussed in detail. Among all the scaffolding technologies, additive manufacturing (AM) is very promising because of its ability to precisely control fiber diameter, orientation, and pore network micro-architecture to mimic the native meniscus microenvironment.

Tendon and ligament as novel cell sources for engineering the knee meniscus

OBJECTIVE

The application of cell-based therapies in regenerative medicine is hindered by the difficulty of acquiring adequate numbers of competent cells. For the knee meniscus in particular, this may be solved by harvesting tissue from neighboring tendons and ligaments. In this study, we have investigated the potential of cells from tendon and ligament, as compared to meniscus cells, to engineer scaffold-free self-assembling fibrocartilage.

METHOD

Self-assembling meniscus-shaped constructs engineered from a co-culture of articular chondrocytes and either meniscus, tendon, or ligament cells were cultured for 4 weeks with TGF-β1 in serum-free media. After culture, constructs were assessed for their mechanical properties, histological staining, gross appearance, and biochemical composition including cross-link content. Correlations were performed to evaluate relationships between biochemical content and mechanical properties.

RESULTS

In terms of mechanical properties as well as biochemical content, constructs engineered using tenocytes and ligament fibrocytes were found to be equivalent or superior to constructs engineered using meniscus cells. Furthermore, cross-link content was found to be correlated with engineered tissue tensile properties.

CONCLUSION

Tenocytes and ligament fibrocytes represent viable cell sources for engineering meniscus fibrocartilage using the self-assembling process. Due to greater cross-link content, fibrocartilage engineered with tenocytes and ligament fibrocytes may maintain greater tensile properties than fibrocartilage engineered with meniscus cells.

Biological Knee Reconstruction With Concomitant Autologous Chondrocyte Implantation and Meniscal Allograft Transplantation: Mid- to Long-term Outcomes

BACKGROUND

Treating articular cartilage defects and meniscal deficiency is challenging. Although some short- to mid-term follow-up studies report good clinical outcomes after concurrent autologous chondrocyte implantation (ACI) and meniscal allograft transplantation (MAT), longer follow-up is needed.

PURPOSE

To evaluate mid- to long-term outcomes after combined ACI with MAT.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

We performed a retrospective review of prospectively gathered data from patients who had undergone ACI with MAT between 1999 and 2013. A single surgeon treated 18 patients for symptomatic full-thickness chondral defects with meniscal deficiency. One patient was lost to follow-up. Thus, 17 patients (18 knees; mean age, 31.7 years) were evaluated over a mean 7.9-year follow-up (range, 2-16 years). A mean 1.8 lesions per knee were treated over a total surface area of 7.6 cm² (range, 2.3-21 cm²) per knee. Seventeen lateral and 1 medial MATs were performed. Survival was analyzed using the Kaplan-Meier method. The modified Cincinnati Knee Rating Scale, Western Ontario and McMaster Universities Osteoarthritis Index, visual analog scale, and Short Form-36 were used to evaluate clinical outcomes. Patients also self-reported knee function and satisfaction. Standard radiographs were scored for Kellgren-Lawrence (K-L) grade.

RESULTS

Both 5- and 10-year survival rates were 75%. Outcomes for 6 knees were considered failures. Of the 6 failures, 4 knees were converted to arthroplasty and the other 2 knees underwent biological revision surgery. Of the 12 successfully operated knees, all clinical measures significantly improved postoperatively. Ten patients representing 11 of the 12 knees rated outcomes for their knees as good or excellent, and 1 rated their outcome as fair. Eight patients representing 9 of the 12 knees were satisfied with the procedure. There was no significant osteoarthritis progression based on K-L grading from preoperatively to a mean 5.9 years after surgery. Seven of the 12 knees (58%) required subsequent surgical procedures (5 arthroscopic alone, 2 both arthroscopic and open).

CONCLUSION

Combined ACI with MAT provided significant improvement in 65% of the operated knees over a mid- to long-term follow-up. This procedure can allow patients to retain their biological knees, delay or prevent rapid degeneration to osteoarthritis, and could be recognized as a bridge procedure before artificial knee replacement. However, careful discussion between the patient and surgeon is necessary before surgery to ensure realistic expectations.

Arthroscopic Partial Meniscectomy or Conservative Treatment for Nonobstructive Meniscal Tears: A Systematic Review and Meta-analysis of Randomized Controlled Trials

PURPOSE

To conduct a meta-analysis of randomized controlled trials comparing the outcome of arthroscopic partial meniscectomy (APM) with conservative treatment in adults with nonobstructive meniscal tears and to recommend a treatment of choice.

METHODS

We systematically searched the databases of MEDLINE, Excerpta Medica Database, Cochrane, the National Health Service Centre for Reviews and Dissemination, and Physiotherapy Evidence Database from inception to May 2, 2016. Two authors independently searched the literature and selected eligible studies. The meta-analyses used a random-effects model. The primary outcome was physical function, measured by knee-specific patient-reported outcomes. Secondary outcomes included knee pain, activity level, the progression of osteoarthritis, adverse events, general health, and quality of life.

RESULTS

We included 6 randomized controlled trials, with a total of 773 patients, of whom 378 were randomized to APM and 395 were randomized to the control treatment. After pooling the data of 5 studies, we found small significant differences in favor of the APM group for physical function at 2 to 3 months (mean difference [MD] = 3.31; 95% confidence interval [CI] = 0.69-5.93; P = .01; I(2) = 0% [Lysholm knee score]), and at 6 months (MD = 3.56; 95% CI = 0.24-6.88; P = .04; I(2) = 0% (Knee injury and Osteoarthritis Outcome Score [KOOS] and Western Ontario and McMaster Universities Osteoarthritis Index); standardized MD = 0.17; 95% CI = 0.01-0.32; P = .03; I(2) = 0% [Lysholm knee score, KOOS, and Western Ontario and McMaster Universities Osteoarthritis Index]). We also found small significant differences for pain at 6 months (MD = 3.56; 95% CI = 0.18-6.95; P = .04; I(2) = 0% [KOOS] and MD = 0.56; 95% CI = 0.28-0.83; P ≤ .0001; I(2) = 0% [visual analog scale and numeric rating scale]). We found no significant differences after 12 and 24 months.

CONCLUSIONS

We found small, although statistically significant, favorable results of APM up to 6 months for physical function and pain. However, we found no differences at longer follow-up.

LEVEL OF EVIDENCE

Level I, systematic review and meta-analysis of Level I studies.

The role of meniscal tissue in joint protection in early osteoarthritis

It is widely accepted that partial meniscectomy leads to early onset of osteoarthritis (OA). A strong correlation exists between the amount and location of the resected meniscus and the development of degenerative changes in the knee. On the other hand, osteoarthritic changes of the joint alter the structural and functional integrity of meniscal tissue. These alterations might additionally compromise the limited healing capacity of the meniscus. In young, active patients without cartilage damage, meniscus therapy including partial meniscectomy, meniscus suture, and meniscus replacement has proven beneficial effects in long-term studies. Even in an early osteoarthritic milieu, there is a relevant regenerative potential of the meniscus and the surrounding cartilage. This potential should be taken into account, and meniscal surgery can be performed with the correct timing and the proper indication even in the presence of early OA.

Which patients are less likely to improve during the first year after arthroscopic partial meniscectomy? A multivariate analysis of 201 patients with prospective follow-up

PURPOSE

To determine which specific factors influence the improvements in function and pain at the first year following arthroscopic partial meniscectomy.

METHODS

Between 2012 and 2013, patients who had arthroscopic partial meniscectomy were included (n = 201) and followed prospectively before surgery and at 12 months. Multivariable stepwise analysis included preoperative variables (age, gender, limb side, height, weight, body mass index, comorbidities, smoking, Tegner activity scale, Lysholm knee score, preceding injury and duration of preoperative symptoms) and arthroscopic findings (degree of cartilage lesions, medial or lateral meniscus involvement, type of meniscal tear and concomitant cruciate tear). The Lysholm clinical score at the last follow-up and the time interval for substantial pain relief was modelled as a function of the above predictor variables.

RESULTS

At the last follow-up, the mean Lysholm score improved by 14.6 points (95 % CI 10.4-18.8, P < 0.001), from 68.0 ± 16.1 to 82.6 ± 19.6 points and 153 (76 %) patients declared they were satisfied to have had the operation. The mean time interval for substantial pain relief was 3.5 ± 1.5 months. Females and patients with lower preoperative Lysholm score were correlated with lower post-operative Lysholm score, while females and patients with lateral meniscal tears (compared to medial meniscal tears) were correlated with longer recovery.

CONCLUSIONS

Arthroscopic partial meniscectomy improved pain and function at the first year post-operatively. Female gender, lateral meniscal tear and less favourable preoperative function were relatively correlated to worse post-operative function and longer rehabilitation time.

LEVEL OF EVIDENCE

IV.

Results of meniscectomy and meniscal repair in anterior cruciate ligament reconstruction

Meniscal tears are commonly associated with anterior cruciate ligament (ACL) injuries. A deficient medial meniscus results in knee instability and could lead to higher stress forces on the ACL reconstruction. Comparison of results in meniscectomy and meniscal repairs revealed worse clinical outcomes in meniscectomy, but higher re-operation rates in meniscal repairs. Our aim was to review the results of ACL reconstruction associated with meniscectomy or meniscal repair.

State of the evidence

PURPOSE OF REVIEW

This review focuses on recent studies of osteoarthritis epidemiology, including research on prevalence, incidence, and a broad array of potential risk factors at the person level and joint level.

RECENT FINDINGS

Studies continue to illustrate the high impact of osteoarthritis worldwide, with increasing incidence. Person-level risk factors with strong evidence regarding osteoarthritis incidence and/or progression include age, sex, socioeconomic status, family history, and obesity. Joint-level risk factors with strong evidence for incident osteoarthritis risk include injury and occupational joint loading; the associations of injury and joint alignment with osteoarthritis progression are compelling. Moderate levels of physical activity have not been linked to increased osteoarthritis risk. Some topics of high recent interest or emerging evidence for association with osteoarthritis include metabolic pathways, vitamins, joint shape, bone density, limb length inequality, muscle strength and mass, and early structural damage.

SUMMARY

Osteoarthritis is a complex, multifactorial disease, and there is still much to learn regarding mechanisms underlying incidence and progression. However, there are several known modifiable and preventable risk factors, including obesity and joint injury; efforts to mitigate these risks can help to lessen the impact of osteoarthritis.