Arthroscopy with partial meniscectomy for degenerative tear does not increase the risk of total knee arthroplasty at five year follow up; however, this population undergoes total knee arthroplasty with a lower threshold of osteoarthritis

PURPOSE

Degenerative meniscus tears can cause discomfort in some patients, and when medical treatments fail to provide relief, arthroscopy may be considered before resorting to knee prosthesis. However, the benefits of arthroscopy over nonsurgical treatments in patients over 60 years old are limited, and the evidence regarding its overall efficiency and drawbacks remains scarce. Furthermore, there has been no investigation into whether those patients treated with partial meniscectomy, undergo the knee operation at an earlier stage of osteoarthritis.

METHODS

This study focused on data from a single Belgian hospital, involving patients over 60 years old with internal meniscal tears. The participants were categorized into two groups based on the treatment they received: arthroscopic partial meniscectomy (APM) or conservative management. The primary outcome assessed was the occurrence of knee arthroplasty within a five year period. Secondary outcomes included evaluating the ICRS cartilage grade and the time taken until total knee arthroplasty (TKA).

RESULTS

A total of 194 patients with internal meniscal tears were included in the study. At the 5-year mark, the overall rate of knee arthroplasty was found to be 16.5%, with 11.9% of cases occurring within two years. After the 5-year follow-up, it was observed that 19.2% (24 patients) of the APM group and 11.6% (8 patients) of the conservative management group underwent knee arthroplasty. Notably, patients over 70 years old who underwent APM had a higher risk of eventually requiring TKA compared to those who received conservative management. Additionally, patients who underwent meniscectomy and later underwent TKA showed less wear in the internal compartment of the knee compared to patients in the conservative treatment group who underwent TKA.

CONCLUSION

The study suggests that patients who underwent arthroscopy faced a similar risk of knee arthroplasty compared to those who underwent conservative management, excepted for patients over 70 years old. Despite this similar risk of arthroplasty for the whole population, they exhibited lower osteoarthritis severity when compared to the conservative group.

A unique case of anterior cruciate ligament rupture coexisting with asymptomatic tear of discoid medial meniscus: A case report

INTRODUCTION

Anterior cruciate ligament (ACL) is among the most commonly injured structure in the knee with some also suffering from meniscus injuries. However, an ACL rupture with concomitant injury of the discoid medial meniscus is a very uncommon.

PRESENTATION OF CASE

A 30 years-old male patient came with unstable left knee, with no history of locked knee and tender joint line. The Lachman and anterior drawer test were positive with no sign of meniscus involvement. The Magnetic Resonance Imaging (MRI) result revealed ACL rupture and a double PCL sign suggesting a medial meniscus tear. Arthroscopic knee surgery was performed for partial meniscectomy of the torn discoid medial meniscus followed by ACL reconstruction, followed by rehabilitation protocol. Six months after the procedure, patient was able to return to preinjury activities.

DISCUSSION

Discoid meniscus of the knee is a rare congenital condition, especially at the medial meniscus. Due to its shape, it distributes the stress differently and therefore more prone to injury. Patients may present with complains of medial knee pain, iterative effusion, locking in flexion. Surgical management is appropriate for a torn discoid medial meniscus with type of surgery depends on each case. A bucket-handle type of injury with torn ACL should be managed by meniscectomy followed by ACL reconstruction.

CONCLUSION

A proper diagnosis of ACL rupture and meniscus injury using arthroscopy is a must. A combination of partial meniscectomy of torn discoid meniscus and ACL reconstruction prevents impingement of the graft therefore reducing the risk of graft failure.

Partial meniscectomy using needle arthroscopy associated with significantly less pain and improved patient reported outcomes at two weeks after surgery: A comparison to standard knee arthroscopy

Purpose

to compare immediate post-operative pain and patient-reported outcomes (PROs) after partial meniscectomy with needle (NA) vs. standard (SA) arthroscopy technique.

Methods

A retrospective review of a consecutive series of patients who underwent partial meniscectomy before and after adoption of a needle arthroscopic technique was performed. Meniscus repairs, root repairs, and those with ligamentous injuries were excluded. Total milligram morphine equivalents (MMEs) consumed, Visual analog scale (VAS) pain, and Knee Injury and Osteoarthritis Outcome Scores (KOOS) were compared pre-operatively and at 2 and 6-weeks postoperatively. Univariate analysis was used to compare results.

Results

Nineteen patients were in each group (NA: 10 females, SA: 11 females). Mean ± SD age (NA 42.8 ± 8.4 vs. SA 47.6 ± 10.4 years, p = 0.13) and body mass index (NA 31.4 ± 5.6 vs. SA 35.1 ± 5.4 m/kg2, p = 0.06) were not significantly different. Seventeen (89%) patients in both groups had medial meniscus tears of the posterior horn. Preoperative Outerbridge score was significantly greater in the SA group (3.4 vs. 1.8, p = 0.002); however, preoperative VAS pain (NA 6.1 ± 1.7 vs. SA 6.1 ± 1.8, p = 0.98) and KOOS pain (NA 44 ± 17% vs. SA 37 ± 12.5%, p = 0.20) were similar. Amount of arthroscopic fluid used was significantly greater in the SA vs. NA group (1.4 ± 0.7 vs. 0.5 ± 0.3 L, p < 0.0001), but tourniquet time was equivalent (NA 20 ± 6 vs.16 ± 6 min, p = 0.11). VAS pain scores (NA 1.0 ± 1.1 vs. SA 2.6 ± 1.5, p = 0.0014), KOOS pain (NA 79 ± 15% vs. 58 ± 19%, p = 0.0006), and Quality of Life (QOL) scores (NA 70 ± 22% vs. SA 43 ± 24%, p = 0.001) were significantly better at 2-weeks post-op in the N group. By 6 weeks post-op, all PROs including VAS pain and KOOS scores were similar between groups.

Conclusions

Adoption of a needle arthroscopic technique for partial meniscectomy was associated with significantly improved VAS and KOOS pain scores two-weeks post-operatively. Differences were not sustained at 6 weeks after surgery.

Level of evidence

III, Retrospective Comparison Study.

arthroscopic partial meniscectomy

Objective

To evaluate sick leave after meniscal repair vs arthroscopic partial meniscectomy (APM) and, for comparison, vs the general population.

Method

Using Swedish register data we included all employed persons aged 19-49 years in the general population of Skåne region and identified those having had meniscus repair or APM in the period of 2005-2012. We retrieved data on sick leave during 1 year before until 2 years after surgery. We used logistic regression to estimate the risk differences of being on sick leave and negative binomial model to analyze differences in the number of days on sick leave.

Results

We included 192 persons with meniscus repair, 2481 with APM, and 376 ​345 references without meniscus surgery. Of these, 55% of meniscus repair group, 43% of APM group had any sick leave in the 2-year period following the surgery, while 17% of the references were on sick leave in the corresponding period. The mean (SD) number of days of sick leave after meniscus repair was 55 (77) days and for APM 37 (86) days. Meniscus repair was associated with higher probability of sick leave compared to APM with an adjusted risk difference of 0.13 (95% CI 0.07-0.19).

Conclusion

Persons undergoing meniscus repair have more frequent and 37% longer periods of sick leave in the short term than persons undergoing APM. However, sick leave in the long-term warrant further attention as successful repair may be associated with less knee osteoarthritis development than APM.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

Level III.

Biomechanical assessment of disease outcome in surgical interventions for medial meniscal posterior root tears: a finite element analysis

BACKGROUND

The adverse consequences of medial meniscus posterior root tears have become increasingly familiar to surgeons, and treatment strategies have become increasingly abundant. In this paper, the finite element gait analysis method was used to explore the differences in the biomechanical characteristics of the knee joint under different conditions.

METHODS

Based on CT computed tomography and MR images, (I) an intact knee (IK) model with bone, cartilage, meniscus and main ligaments was established. Based on this model, the posterior root of the medial meniscus was resected, and (ii) the partial tear (PT) model, (iii) the entire radial tear (ERT) model, and (iv) the entire oblique tear (EOT) model were established according to the scope and degree of resection. Then, the (v) meniscus repair (MR) model and (vi) partial meniscectomy (PM) model were developed according to the operation method. The differences in stress, displacement and contact area among different models were evaluated under ISO gait loading conditions.

RESULTS

Under gait loading, there was no significant difference in the maximum stress of the medial and lateral tibiofemoral joints among the six models. Compared with the medial tibiofemoral joint stress of the IK model, the stress of the PM model increased by 8.3%, while that of the MR model decreased by 18.9%; at the same time, the contact stress of the medial tibiofemoral joint of the ERT and EOT models increased by 17.9 and 25.3%, respectively. The displacement of the medial meniscus in the ERT and EOT models was significantly larger than that in the IK model (P < 0.05), and the tibial and femoral contact areas of these two models were lower than those of the IK model (P < 0.05).

CONCLUSIONS

The integrity of the posterior root of the medial meniscus plays an important role in maintaining normal tibial-femoral joint contact mechanics. Partial meniscectomy is not beneficial for improving the tibial-thigh contact situation. Meniscal repair has a positive effect on restoring the normal biomechanical properties of the medial meniscus.

No evidence in support of arthroscopic partial meniscectomy in adults with degenerative and nonobstructive meniscal symptoms: a level I evidence-based systematic review

PURPOSE

It is unclear whether the results of arthroscopic partial meniscectomy (APM) are comparable to a structured physical therapy (PT). This systematic review investigated efficacy of APM in the management of symptomatic meniscal damages in middle aged patients. Current available randomised controlled trials (RCTs) which compared APM performed in isolation or combined with physical therapy versus sham arthroscopy or isolated physical therapy were considered in the present systematic review.

METHODS

This systematic review was conducted according to the 2020 PRISMA statement. All the level I RCTs which investigated the efficacy of AMP were accessed. Studies which included elderlies with severe OA were not eligible, nor were those in which APM was combined with other surgical intervention or in patients with unstable knee or with ligaments insufficiency. The risk of bias was assessed using the software Review Manager 5.3 (The Nordic Cochrane Collaboration, Copenhagen). To rate the quality of evidence of collected outcomes, the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) was used.

RESULTS

Data from 17 studies (2037 patients) were collected. 48.5% (988 of 2037 patients) were women. The mean age of the patients was 52.7 ± 3.9 years, the mean BMI 27.0 ± 1.3 kg/m². The current evidence suggests no difference in functional PROMs (quality of the evidence: high), clinical PROMs (quality of the evidence: high), pain (quality of the evidence: high), quality of life (quality of the evidence: high), physical performance measures (quality of the evidence: moderate), and OA progression (quality of the evidence: moderate).

CONCLUSIONS

The benefits of APM in adults with degenerative and nonobstructive meniscal symptoms are limited. The current evidence reports similarity in the outcome between APM and PT. Further long-term RCTs are required to investigate whether APM and PT produce comparable results using validated and reliable PROMs. Moreover, future RCTs should investigate whether patients who might benefit from APM exist, clarifying proper indications and outcomes. High quality investigations are strongly required to establish the optimal PT regimes.

LEVEL OF EVIDENCE

Level I.

Treatment, Return to Play, and Performance Following Meniscus Surgery

PURPOSE OF REVIEW

The standard of care in meniscal tear management is constantly evolving, especially for athletes and high-demand patients. Meniscus repairs, meniscus transplants, and partial meniscectomies are commonly performed, and rehabilitation methods following these operations are becoming more sophisticated. The ultimate goal of these procedures is returning patients to full activity with minimal risks. Return to play should be systematic, pathology dependent, and individualized to an athlete's needs, expectations, and level of play. This article provides a review of the current treatment modalities of meniscus tears, the rehabilitation protocols following each modality, and the return to play criteria that must be met before releasing the player to competition. In addition, it overviews articles that describe performance outcomes of patients that have undergone meniscus surgery.

RECENT FINDINGS

Current research shows high return to play rates for athletes that undergo meniscus surgery and describes effective rehabilitation protocols to facilitate recovery. There is an increased emphasis on meniscus preservation in recent literature. In addition, meniscus allograft transplantation has demonstrated its efficacy as a salvage procedure and has become a stronger consideration in the athlete with meniscus pathology. No standardized return to play protocol can be applied uniformly to all kinds of meniscal surgeries, and two athletes with the same pathology cannot be expected to follow identical paths towards full recovery. A multidisciplinary approach to care should be provided to the patients, and in the case of patients with high levels of athleticism, the road to recovery starts even before the injury itself.

Treatment of post-meniscectomy knee symptoms with medial meniscus replacement results in greater pain reduction and functional improvement than non-surgical care

PURPOSE

Partial meniscectomy is a common orthopedic procedure intended to improve knee pain and function in patients with irreparable meniscal tears. However, 6-25% of partial meniscectomy patients experience persistent knee pain after surgery. In this randomized controlled trial (RCT) involving subjects with knee pain following partial meniscectomy, it was hypothesized that treatment with a synthetic medial meniscus replacement (MMR) implant provides significantly greater improvements in knee pain and function compared to non-surgical care alone.

METHODS

In this prospective, multicenter RCT, subjects with persistent knee pain following one or more previous partial meniscectomies were randomized to receive either MMR or non-surgical care. This analysis evaluated the 1-year outcomes of this 2-year clinical trial. Patient-reported knee pain, function, and quality of life were measured using nine separate patient-reported outcomes. The primary outcomes were the pain subscale of the Knee injury and Osteoarthritis Outcome Score (KOOS) and the average of all five KOOS subscales (KOOS Overall). Treatment cessation was defined as permanent device removal in the MMR group and any surgical procedure to the index knee in the non-surgical care group.

RESULTS

Treated subjects had a median age of 52 years old (range 30-69 years) and one or more previous partial meniscectomies at a median of 34 months (range 5-430 months) before trial entry. Among 127 subjects treated with either MMR (n = 61) or non-surgical care (n = 66), 11 withdrew from the trial or were lost to follow-up (MMR, n = 0; non-surgical care, n = 11). The magnitude of improvement from baseline to 1 year was significantly greater in subjects who received MMR in both primary outcomes of KOOS Pain (P = 0.013) and KOOS Overall (P = 0.027). Treatment cessation was reported in 14.5% of non-surgical care subjects and only 4.9% of MMR subjects (n.s.).

CONCLUSION

Treatment with the synthetic MMR implant resulted in significantly greater improvements in knee pain, function, and quality of life at 1 year of follow-up compared to treatment with non-surgical care alone.

LEVEL OF EVIDENCE

I.

Intrasubstance degeneration of medial meniscus horizontal cleavage tear in young patients is associated with increased joint line obliquity in the coronal plane of the knee

PURPOSE

To evaluate the effect of joint line obliquity of the knee on intrasubstance degeneration of isolated medial meniscus horizontal cleavage tear (HCT) in young patients.

METHODS

Sixty knees of 50 patients aged < 40 years (mean age, 33.3 ± 5.5 years old), who underwent arthroscopic partial meniscectomy (APM) for HCT, were retrospectively reviewed. The radiologic parameters of alignment, including mechanical hip-knee-ankle (mHKA) angle, posterior tibial slope, and joint line obliquity, were measured on preoperative long-standing whole-leg radiographs. The patients were classified into two groups, simple horizontal type (type 1) and complicated type (type 2), according to the presence of diffuse intrasubstance degeneration of the meniscus on preoperative magnetic resonance imaging. The risk factors for intrasubstance degeneration of HCT were analyzed using multiple logistic regression analysis. Medial joint space width (JSW) on weight-bearing 45° flexion posteroanterior radiographs and the mHKA were measured to evaluate the radiographic outcomes. The clinical outcomes were evaluated using the modified Lysholm score. Among patients followed-up for > 5 years, the clinical and radiologic outcomes were compared between the two groups.

RESULTS

The joint line obliquity was significantly greater in the type 2 group than in the type 1 group (2.9 ± 1.3 vs. 0.9 ± 1.4, P < 0.001), and a significant risk factor for diffuse intrasubstance degeneration (P < 0.001; odds ratio, 2.88; 95% confidence interval, 1.27-6.54). The relative changes in the JSW in the type 2 group were greater than those in the type 1 group during the mean follow-up period of 7.9 ± 2.5 years (26% vs 10%, P = 0.045). The modified Lysholm score was not significantly different between the two groups (n.s).

CONCLUSION

The diffuse intrasubstance degeneration of medial meniscus HCTs in young patients is associated with increased joint line obliquity of the knee joints. The radiologic outcomes after APM were inferior in the patients with diffuse intrasubstance degeneration. However, the clinical outcomes were not different during the mid-term follow-up.

LEVEL OF EVIDENCE

Level III.

Can an injured discoid lateral meniscus be returned to the correct anatomic position and size of the native lateral meniscus after surgery?

BACKGROUND

No previous studies have compared the position and size of the remaining discoid lateral meniscus (DLM) with that of a normal lateral meniscus. This study aimed to evaluate the postoperative position and size of DLM compared with that of normal controls using magnetic resonance imaging (MRI).

METHODS

This retrospective study involved 52 symptomatic complete type DLMs (discoid group) who underwent arthroscopic surgery and 50 normal controls (control group). Pre- and postoperative MRI evaluations, height, width, and relative percentage of extrusion (RPE) were assessed. Sagittal position parameters, including distances from articular cartilage center to anterior meniscus (CAMD) and from anterior articular cartilage margin to anterior horn (ACMD), were also assessed. Logistic regression analysis was performed to find factors with extrusion of remaining DLM.

RESULTS

The height of the discoid group was significantly lower than that of the control group (P = 0.000). RPE in the discoid group was significantly larger than in the control group (P = 0.005). Only CAMD and ACMD in the discoid group were different (positioned more anteriorly) from the control group (P = 0.000). Preoperative meniscal shift (odds ratio (OR): 12.448; P = 0.003) and operative technique, especially partial meniscectomy with repair (OR: 19.125; P = 0.000), were the major factors associated with extrusion.

CONCLUSION

The width of remaining DLM was comparable to that of normal controls, but the position was found to be more anterior and lateral than that of normal controls. Preoperative meniscal shift and combined meniscus repair were the major factors for smaller width and greater extrusion; thus, surgeons should address and counsel these factors before surgery.

Partial meniscectomy provides the favorable outcomes for symptomatic medial meniscus tear with an intact posterior root

PURPOSE

This study aimed to investigate the long-term outcomes of arthroscopic partial meniscectomy for medial meniscus tear (with intact posterior root) and to analyze the risk factors for treatment failure.

METHODS

The records of 165 patients who underwent partial meniscectomy for medial meniscus tear with intact posterior root with a minimum 5-year follow-up were included. Modified Lysholm score and radiologic outcomes were compared between preoperative and latest follow-up periods. The cumulative Outerbridge grade of the medial compartment was defined as follows: 0-4, low chondral wear; 5-6, intermediate wear; or 7-8, high wear. Kaplan-Meier survival and Cox hazard regression analyses were performed to assess the survivorship after partial meniscectomy. Conversion to total knee replacement arthroplasty, high tibial osteotomy or a Lysholm score of < 65 points indicated treatment failure.

RESULTS

Mean Lysholm score improved from 66.3 ± 14.2 preoperatively to 81.8 ± 17.9 at the latest follow-up (p = 0.001). The postoperative 10-year survival rate of the low chondral wear group [97% (95% confidence interval (CI) 141.7-152.6 months)] was higher than that of the intermediate [83.1% (95% CI 129.6-147.9 months)] and high wear groups [76.1% (95% CI 115.2-135.0 months)]. A 1 mm joint space width narrowing led to a 37.7% increase in the failure rate [B = - 0.473; hazard ratio, 0.623 (95% CI 0.423-0.917); p = 0.016]. The high chondral wear group showed a higher failure rate compared to the low wear group [B = 1.870; hazard ratio, 6.488 (95% CI 0.853-49.333); p = 0.041].

CONCLUSION

Partial meniscectomy offers pain relief and functional improvement for medial meniscus tear with intact posterior root. Preoperative joint space narrowing and higher chondral wear at surgery were significant risk factors of treatment failure. Partial meniscectomy should be considered as an effective treatment for irreparable medial meniscus tear with intact posterior root without joint space narrowing and chondral wear.

LEVEL OF EVIDENCE

Case series, Level IV.

Chondral lesions at the medial femoral condyle, meniscal degeneration, anterior cruciate ligament insufficiency, and lateral meniscal tears impair the middle-term results after arthroscopic partial meniscectomy

PURPOSE

The aim of the present study was to analyse which clinical, radiological and arthroscopic findings are able to predict the postoperative outcome after arthroscopic partial meniscectomy. Furthermore, the present study aimed to investigate the postoperative outcome after partial meniscectomy in patients with degenerative meniscal lesions.

METHODS

A total of 91 patients with a follow-up period of 34.7 ± 11.4 months after arthroscopic partial meniscectomy were included in this retrospective study. Clinical, radiological, and arthroscopic data were analysed at the time of follow-up. The multivariable linear regression analysis for postoperative outcome, based on the Western Ontario Meniscal Evaluation Tool (WOMET), included age, gender, body mass index, physical activity, presence of cartilage lesions, leg alignment, grade of radiographic osteoarthritis, location of meniscal lesions, meniscal extrusion, meniscal degeneration, presence of an anterior cruciate ligament tears as well as bone marrow lesions.

RESULTS

WOMET and WOMAC scores showed a significant improvement of 45.0 ± 48.1 points (CI 34.9-55.1; p ≤ 0.0001) and 75.1 ± 69.3 points (CI 60.6-89.6; p = 0.001) within the follow-up period. Multivariable linear regression analysis showed that poor preoperative WOMET scores (p = 0.001), presence of cartilage lesions at the medial femoral condylus (p = 0.001), meniscal degeneration (p = 0.008), the presence of an anterior cruciate ligament lesion (p = 0.005), and lateral meniscal tears (p = 0.039) were associated with worse postoperative outcomes. Patients with femoral bone marrow lesions had better outcome (p = 0.038).

CONCLUSION

Poor preoperative WOMET scores, presence of cartilage lesions at the medial femoral condylus, meniscal degeneration, concomitant anterior cruciate ligament lesions as well as lateral meniscal tears are correlated with worse postoperative outcomes after arthroscopic partial meniscectomy. Patients with femoral bone marrow lesions femoral are more likely to gain benefit from arthroscopic partial meniscectomy in the middle term. Despite justified recent restrictions in indication, arthroscopic partial meniscectomy seems to effectively reduce pain and alleviate symptoms in carefully selected patients with degenerative meniscal tears.

LEVEL OF EVIDENCE

III.

Development of osteoarthritis in patients with degenerative meniscal tears treated with exercise therapy or surgery: a randomized controlled trial

OBJECTIVE

To evaluate progression of individual radiographic features 5 years following exercise therapy or arthroscopic partial meniscectomy as treatment for degenerative meniscal tear.

DESIGN

Randomized controlled trial including 140 adults, aged 35-60 years, with a magnetic resonance image verified degenerative meniscal tear, and 96% without definite radiographic knee osteoarthritis. Participants were randomized to either 12-weeks of supervised exercise therapy or arthroscopic partial meniscectomy. The primary outcome was between-group difference in progression of tibiofemoral joint space narrowing and marginal osteophytes at 5 years, assessed semi-quantitatively by the OARSI atlas. Secondary outcomes included incidence of radiographic knee osteoarthritis and symptomatic knee osteoarthritis, medial tibiofemoral fixed joint space width (quantitatively assessed), and patient-reported outcome measures. Statistical analyses were performed using a full analysis set. Per protocol and as treated analysis were also performed.

RESULTS

The risk ratios (95% CI) for progression of semi-quantitatively assessed joint space narrowing and medial and lateral osteophytes for the surgery group were 0.89 (0.55-1.44), 1.15 (0.79-1.68) and 0.77 (0.42-1.42), respectively, compared to the exercise therapy group. In secondary outcomes (full-set analysis) no statistically significant between-group differences were found.

CONCLUSION

The study was inconclusive with respect to potential differences in progression of individual radiographic features after surgical and non-surgical treatment for degenerative meniscal tear. Further, we found no strong evidence in support of differences in development of incident radiographic knee osteoarthritis or patient-reported outcomes between exercise therapy and arthroscopic partial meniscectomy.

TRIAL REGISTRATION

www.clinicaltrials.gov (NCT01002794).

Reduction of in situ force through the meniscus with phased inner resection of medial meniscus: an experimental study in a porcine model

PURPOSE

Partial meniscectomy can cause osteoarthritic changes in knees, as inner portion as well as peripheral portion of meniscus is important. The hypothesis of this study was that the amount of the inner resection of medial meniscus affected the in situ forces through the meniscus and the tibial varus and external rotation under axial load.

METHODS

Fourteen intact porcine knees were investigated with a six-degree of freedom robotic system and force/moment, and the three-dimensional path of intact knees were recorded by universal force sensor when an axial load of 300-N was applied at four different flexion angles (30°, 60°, 90°, and 120°). The same examination was performed on three phased inner resections (30%, 60%, and 90% width) of the medial meniscus. Finally, all paths were reproduced after total medial meniscectomy, and in situ forces of the medial meniscus were calculated based on the superposition principle. Changes in tibiofemoral varus/valgus and internal/external rotation alignment during an axial load were also calculated.

RESULTS

In situ forces of the medial meniscus decreased according to the amount of meniscal resection at all flexion angles. The reduction was significant in knees with inner resections of > 60% width at all flexion angles and even of 30% width at a flexion angle of 120° (p < .05). Incremental changes in the tibiofemoral varus alignment increased depending on the inner resection width at all flexion angles (p < .05).

CONCLUSION

The amount of inner resection of the medial meniscus was related to reduction of its in situ forces and increment of the tibial varus rotation under axial load.

Medium-Term Results of Arthroscopic Partial Meniscectomy from a Single High-Volume Center

AIM

Clinical practice is moving away from treating meniscal tears in patients with osteoarthritis unless there are mechanical symptoms. This study assessed the risk of needing further surgery for osteoarthritis in the 5 years following partial meniscectomy in different age groups and different grades of knee osteoarthritis.

METHODS

All partial meniscectomies were performed by the senior author during a 31-month period. Data were collected and analyzed retrospectively using electronic patients' records and imaging database. Patients who had previous arthroscopy, anterior cruciate ligament pathology, discoid meniscus or were less than 34 years old were excluded from the study. Range of follow-up was 3 to 5 years. Osteoarthritis was classified intra-operatively using the Outerbridge classification. Knees that needed further surgical treatment in the form of joint replacement or osteotomy were considered as failures. The population was split into three groups according to their age (35-54, 55-64 and 65+). Survival analysis was calculated using the life table method.

RESULTS

207 knees were included. In the 35-54 age group, patients with no/mild OA had a survival rate of 97.59% and the severe OA group had a survival rate of 73.5%. In the 55-64 age group, these figures were 100% and 73.6%, respectively. In the >65 age group, the survival rates were 100% and 65%, respectively.

CONCLUSION

Our study shows that patients with no/mild OA should be considered for APM. Patient's with meniscal tears and severe OA should be counseled on the outcomes and risks of further surgery after an APM.

Partial medial meniscectomy leads to altered walking mechanics two years after anterior cruciate ligament reconstruction: Meniscal repair does not

BACKGROUND

Partial meniscectomy dramatically increases the risk for post-traumatic, tibiofemoral osteoarthritis after anterior cruciate ligament reconstruction (ACLR). Concomitant medial meniscus surgery influences walking biomechanics (e.g., medial tibiofemoral joint loading) early after ACLR; whether medial meniscus surgery continues to influence walking biomechanics two years after ACLR is unknown.

RESEARCH QUESTION

Does medial meniscus treatment at the time of ACLR influence walking biomechanics two years after surgery?

METHODS

This is a secondary analysis of prospectively collected data from a clinical trial (NCT01773317). Fifty-six athletes (age 24 ± 8 years) with operative reports, two-year biomechanical analyses, and no second injury prior to two-year testing participated after primary ACLR. Participants were classified by concomitant medial meniscal status: no medial meniscus involvement (n = 36), partial medial meniscectomy (n = 9), and medial meniscus repair (n = 11). Participants underwent biomechanical analyses during over-ground walking including surface electromyography; a validated musculoskeletal model estimated medial compartment tibiofemoral contact forces. Gait variables were analyzed using 3 × 2 ANOVAs with group (medial meniscus treatment) and limb (involved versus uninvolved) comparisons.

RESULTS

There was a main effect of group (p = .039) for peak knee flexion angle (PKFA). Participants after partial medial meniscectomy walked with clinically meaningfully smaller PKFAs in both the involved and uninvolved limbs compared to the no medial meniscus involvement group (group mean difference [95%CI]; involved: -4.9°[-8.7°, -1.0°], p = .015; uninvolved: -3.9°[-7.6°, -0.3°], p = .035) and medial meniscus repair group (involved: -5.2°[-9.9°, -0.6°], p = .029; uninvolved: -4.7°[-9.0°, -0.3°], p = .038). The partial medial meniscectomy group walked with higher involved versus uninvolved limb medial tibiofemoral contact forces (0.45 body weights, 95% CI: -0.01, 0.91 BW, p = 0.053) and truncated sagittal plane knee excursions, which were not present in the other two groups.

SIGNIFICANCE

Aberrant gait biomechanics may concentrate high forces in the antero-medial tibiofemoral cartilage among patients two years after ACLR plus partial medial meniscectomy, perhaps explaining the higher osteoarthritis rates and offering an opportunity for targeted interventions.

LEVEL OF EVIDENCE

Level III.

Midbody of the medial meniscus as a reference of preservation in partial meniscectomy for complete discoid lateral meniscus

PURPOSE

To evaluate the postoperative size of discoid lateral meniscus using magnetic resonance imaging (MRI) after partial meniscectomy relative to the size of medial meniscus midbody.

METHODS

This study included 48 patients who underwent arthroscopic partial meniscectomy with or without repair for symptomatic complete discoid meniscus. The intraoperative size of midbody of medial meniscus was used as a reference for partial meniscectomy. MRIs were performed pre- and postoperatively. Quantitative evaluations of the height, width, extrusion of the meniscus, and relative percentage of extrusion in the coronal and sagittal planes were completed. Demographic data, preoperative shift, type of shift, and operative technique were analyzed while considering the remaining meniscus. Logistic regression analyses were used.

RESULTS

The mean remaining discoid meniscal width in the coronal plane of MRI was not significantly different from the width of midbody of medial meniscus (9.1 ± 4.2 mm vs. 9.4 ± 1.4 mm, n.s.) Absolute meniscal extrusion and relative percentage of extrusion in the coronal plane and the ratio of t meniscus in sagittal plane of the final MRI were significantly increased as compared with the preoperative MRI. Preoperative shift was a risk factor for the reduction of remaining meniscal width (odds ratio 11.997, p = 0.016, 95% CI 1.586-90.737).

CONCLUSION

The size of midbody of medial meniscus could be a reference for partial meniscectomy in symptomatic complete discoid meniscus. Preoperative shift represents a risk factor for decreased remaining meniscal width. These findings could be helpful in ensuring appropriate surgical planning and explaining poor prognostic factors.

LEVEL OF EVIDENCE

Prospective cohort study, Level II.

Distinct degenerative phenotype of articular cartilage from knees with meniscus tear compared to knees with osteoarthritis

OBJECTIVE

To compare the transcriptome of articular cartilage from knees with meniscus tears to knees with end-stage osteoarthritis (OA).

DESIGN

Articular cartilage was collected from the non-weight bearing medial intercondylar notch of knees undergoing arthroscopic partial meniscectomy (APM; N = 10, 49.7 ± 10.8 years, 50% females) for isolated medial meniscus tears and knees undergoing total knee arthroplasty (TKA; N = 10, 66.0 ± 7.6 years, 70% females) due to end-stage OA. Ribonucleic acid (RNA) preparation was subjected to SurePrint G3 human 8 × 60K RNA microarrays to probe differentially expressed transcripts followed by computational exploration of underlying biological processes. Real-time polymerase chain reaction amplification was performed on selected transcripts to validate microarray data.

RESULTS

We observed that 81 transcripts were significantly differentially expressed (45 elevated, 36 repressed) between APM and TKA samples (≥ 2 fold) at a false discovery rate of ≤ 0.05. Among these, CFD, CSN1S1, TSPAN11, CSF1R and CD14 were elevated in the TKA group, while CHI3L2, HILPDA, COL3A1, COL27A1 and FGF2 were highly expressed in APM group. A few long intergenic non-coding RNAs (lincRNAs), small nuclear RNAs (snoRNAs) and antisense RNAs were also differentially expressed between the two groups. Transcripts up-regulated in TKA cartilage were enriched for protein localization and activation, chemical stimulus, immune response, and toll-like receptor signaling pathway. Transcripts up-regulated in APM cartilage were enriched for mesenchymal cell apoptosis, epithelial morphogenesis, canonical glycolysis, extracellular matrix organization, cartilage development, and glucose catabolic process.

CONCLUSIONS

This study suggests that APM and TKA cartilage express distinct sets of OA transcripts. The gene profile in cartilage from TKA knees represents an end-stage OA whereas in APM knees it is clearly earlier in the degenerative process.

The ACL-deficient knee and the prevalence of meniscus and cartilage lesions: a systematic review and meta-analysis (CRD42017076897)

INTRODUCTION

The purpose of this systematic review and meta-analysis was to analyze and compare the rate of secondary meniscus and cartilage lesions diagnosed at different time points of ACL reconstruction.

MATERIALS AND METHODS

A systematic search for articles comparing the rate of secondary meniscus and cartilage lesions diagnosed at different time points of ACL reconstruction was performed. PubMed central was the database used for the literature review.

RESULTS

Forty articles out of 1836 were included. In 35 trials (88%), there was evidence of a positive correlation between the rate of meniscus and/or cartilage lesions and the time since ACL injury. This correlation was more evident for the medial meniscus in comparison with the lateral meniscus. In particular, a delay of more than 6 months was critical for secondary medial meniscus injuries [risk ratio 0.58 (95% CI 0.44-0.79)] and a delay of more than 12 months was critical for cartilage injuries [risk ratio 0.42 (95% CI 0.29-0.59)]. Additionally, there is evidence that the chance for meniscal repair decreases as the time since ACL rupture increases.

CONCLUSION

Chronic instability in the ACL-deficient knee is associated with a significant increase of medial meniscus injuries after 6 months followed by a significant increase of cartilage lesions after 12 months.

Subgroups of patients with osteoarthritis and medial meniscus tear or crystal arthropathy benefit from arthroscopic treatment

PURPOSE

The purpose of this study was to perform a systematic review of prospective randomized controlled trials comparing arthroscopic treatment for knee osteoarthritis (OA) with either other therapeutic interventions or sham treatment.

METHODS

A systematic search for randomized controlled trials (RCT) about arthroscopic treatment (AT) for knee OA was performed according to the PRISMA guidelines. Arthroscopic treatment included procedures such as lavage, debridement and partial meniscectomy of the knee. Data source was PubMed central.

RESULTS

Fourteen articles could be included. Five studies compared interventive AT with either sham surgery, lavage or diagnostic arthroscopy. Nine trials compared AT with another active intervention (exercise, steroid injection, hyaluronic acid injection). In ten trials, the clinical scores improved after arthroscopic treatment of knee OA in comparison to the baseline. In seven trials, there was a significant difference in the final clinical outcome with higher scores for patients after arthroscopic OA treatment in comparison to a control group. In four trials, the intention to treat analysis revealed no significant difference between arthroscopic OA treatment and the control group. In one of those trials, which compared arthroscopic partial meniscectomy (APM) with exercise, the cross over rate from exercise to AT was 34.9%. The clinical scores of cross-over patients improved after APM. In one study, the subgroup analysis revealed that patients with tears of the anterior two-thirds of the medial meniscus or any lateral meniscus tear had a higher probability of improvement after arthroscopic surgery than did patients with other intraarticular pathology. There was no difference in the side effects between patients with AT and the control group. Despite acceptable scores in the methodological quality assessment, significant flaws could be found in all studies. These flaws include bad description of the exact surgical technique or poor control of postoperative use of non-steroidal anti-inflammatory drugs (NSAID).

CONCLUSION

Results of RCTs comparing AT with other treatment options were heterogeneous. AT in OA patients is not useless because there is evidence that a subgroup of patients with non-traumatic flap tears of the medial meniscus or patients with crystal arthropathy benefit from arthroscopy. This topic has a high relevance because several health insurances do not reimburse arthroscopy for patients with OA anymore. The results of these randomized studies, however, should be interpreted with care because in many studies, the use of other therapeutic variables such as pain killers or NSAIDs was not controlled or reported.

LEVEL OF EVIDENCE

I.

Partial meniscectomy adversely affects return-to-sport outcome after anatomical double-bundle anterior cruciate ligament reconstruction

PURPOSE

The purposes of this study were to determine whether the partial meniscectomy combined with ACL reconstruction affect the postoperative return-to-sport and to identify if partial meniscectomy has an influence on the graft failure following an anatomical double-bundle ACL reconstruction case.

METHODS

A retrospective cohort study including 426 primary double bundle ACL reconstruction cases. There were 206 males and 220 females, median age of 28.4 years, median BMI of 23.0, median preinjury Tegner score of 7.0 and median follow-up period after surgery of 24.0 months. Patients with less than 12 months of follow-up, revision surgery, multi-ligaments injury, previous contralateral knee ligaments injury and postoperative infection cases were excluded. Furthermore, patients who had meniscal repair were excluded in order to compare the outcomes between patients who had intact menisci and those who underwent partial meniscectomy. There were 227 patients with intact menisci (group A) and 199 patients with partial meniscectomy (group B). The median age was younger and the preoperative Tegner score was higher in group A. The patients in group B were subcategorized as the site of partial meniscectomy, including medial (group C), lateral (group D) and bicompartmental (group E) meniscectomy. There were 74, 94, and 31 patients in group C, D, and E, respectively. Return-to-sport (running and sport phase) and graft failure were included in our primary outcomes, and functional outcome as Lysholm knee scores was included in secondary outcome.

RESULTS

The rate of return to running phase and sport phase were 91% (387/426) and 76% (303/399), the mean time taken to return to running and sport phase were 5.7 months and 11.1 months, respectively. There was significant difference in the returning to sport phase between group A and B (p = 0.01), and between group A and D/E subgroups (p = 0.007). There were fourteen graft failures (3.5%) in total. In addition, 9 and 5 graft failures in group A and B, respectively. Of the 5 graft failures in group B, 2 and 3 graft failures in group C and D, respectively. There was no significant difference of the graft failure ratio among the groups.

CONCLUSION

Our study demonstrates that partial meniscectomy has an adverse effect on the return to sport phase following the anatomical double-bundle ACL reconstruction. Therefore, greater postoperative care would be needed to return to sport with partial meniscectomy in ACL reconstruction cases. On the contrary, partial meniscectomy is not considered to be the risk factor for graft failure at short-term follow-up.

LEVEL OF EVIDENCE

Case-control study, Level III.

Meniscal repair associated with a partial meniscectomy for treating complex horizontal cleavage tears in young patients may lead to excellent long-term outcomes

INTRODUCTION

While open repair of horizontal meniscal tears in young active patients has shown good results at mid- and long-term follow-up, complex horizontal tears (cleavage associated with meniscal flaps) are often treated by arthroscopic subtotal meniscectomy. The aim of this study was to evaluate long-term outcomes after arthroscopic removal of meniscal flaps associated with an open meniscal repair for treating complex lesions in young active patients. The hypothesis was that this salvage procedure would be efficient in such rare cases.

METHODS

Fourteen patients underwent an arthroscopic partial meniscectomy associated with an open meniscal repair to treat a painful complex horizontal meniscal cleavage between 2005 and 2010. There were two females and 12 males with a median age of 28.4 years (range 15-48 years). Patients were assessed by KOOS and IKDC scores, return to sport and the need for a secondary meniscectomy.

RESULTS

Thirty patients were evaluated at a median follow-up of 8.5 years (range 7-12 years). One patient required revision of a partial meniscectomy and one other a meniscal replacement (15% failure rate). All other patients showed improvement with regard to their symptoms and returned to sports, ten (91%) of them at the same level. The mean IKDC subjective score was 86.1 (± 10.9). The mean KOOS scores were: pain 91.4 (± 7.5), symptoms 91.4 (± 10.2), daily activity 97.1 (± 4), sports 84.4 (± 20.7) and quality of life 84 (± 14.2). For six patients, scores at median follow-up of 2.6 years were available and compared to newly obtained data. IKDC score at 8.6 years follow-up was not significantly different. KOOS scores for daily activity and sports were maintained.

CONCLUSIONS

Even in the presence of a complex lesion, horizontal cleavage can be repaired in young patients with good subjective and objective outcomes and a low rate of long-term failure as with other meniscal lesions in young active patients.

LEVEL OF EVIDENCE

IV.

Introduction of an MR-based semi-quantitative score for assessing partial meniscectomy and relation to knee joint degenerative disease: data from the Osteoarthritis Initiative

OBJECTIVES

To develop an MR-based semi-quantitative meniscus scoring technique for postoperative assessment of the degree of meniscal resection, to test its reproducibility, and to study the relationship between the amount of resection and degenerative disease burden.

METHODS

We studied the right knee of 135 participants from the Osteoarthritis Initiative that underwent meniscal surgery an average of 14 years previously. The amount of meniscal resection was assessed on baseline 3.0-T MRIs and calculated as meniscus resection score (MenRS) with a range of 0 to 18. Knee abnormalities at baseline and 48 months were graded using a modified Whole-Organ Magnetic Resonance Imaging Score (WORMS). Subjects were also stratified according to meniscal resection performed after injury versus without preceding injury. Statistical analysis included intra-class correlation coefficient (ICC) to determine reproducibility as well as regression models and partial correlations to correlate MenRS with WORMS outcomes.

RESULTS

ICC values for intra- and inter-observer reproducibility of MenRS were 0.980 and 0.977, respectively. Overall, the amount of meniscal resection showed a significant correlation with baseline WORMS grades: higher MenRS was associated with higher total WORMS grades (p = 0.004) and cartilage (p = 0.004) and ligament (p < 0.001) subscores. However, no significant association between MenRS and change in WORMS grades over 48 months was found. The relationship between MenRS and baseline WORMS grades did not change after adjusting for a reported history of knee injury.

CONCLUSIONS

Postoperative assessment of the knee following partial meniscectomy using the newly developed MenRS showed excellent reproducibility and significant cross-sectional correlation with WORMS gradings.

KEY POINTS

• The newly developed semi-quantitative MR-based meniscal resection score demonstrated excellent reproducibility. • A significant correlation between the amount of meniscal resection measured using the newly developed score and the degree of overall knee joint degenerative disease and cartilage defects was found.

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.

Polyurethane meniscal scaffolds lead to better clinical outcomes but worse articular cartilage status and greater absolute meniscal extrusion

PURPOSE

Implantation of polyurethane (PU) meniscal scaffolds has become a popular procedure to provide a scaffold for vessel ingrowth and meniscal tissue regeneration in patients with partial meniscal defects. However, it is unclear whether PU meniscal scaffolds lead to better clinical and magnetic resonance imaging (MRI) outcomes post-operatively. This meta-analysis compared the clinical and MRI outcomes in patients with partial meniscal defects treated with PU meniscal scaffolds.

METHODS

This meta-analysis reviewed all studies that assessed Lysholm score, International Knee Documentation Committee (IKDC) score, visual analogue scale (VAS) for pain, Tegner score, Knee Injury and Osteoarthritis Outcomes Score (KOOS), articular cartilage (AC), absolute meniscal extrusion (AME), morphology and size (MS), signal intensity (SI) of meniscal implant, and interface of the implant-residual meniscus complex (IIRMC) in patients with partial meniscal defects treated with PU meniscal scaffolds.

RESULTS

Eighteen studies were included in the meta-analysis. The proportion of patients who evaluated MS (OR 0.71, 95% CI 0.38-1.33; n.s.), SI (OR 1.07, 95% CI 0.53-2.18; n.s.), and IIRMC (OR 1.00, 95% CI 0.33-3.06; n.s.) did not differ significantly between baseline and final follow-up. However, AC (OR 0.31, 95% CI 0.11-0.84; P = 0.02) and AME (OR 0.05, 95% CI 0.01-0.18; P < 0.00001) worsened between baseline and final follow-up. Conversely, Lysholm score (95% CI -1.87 to -1.07; P < 0.00001), IKDC score (95% CI -2.19 to -1.08; P < 0.00001), VAS for pain (95% CI -2.29 to -1.07; P < 0.00001), Tegner score (95% CI -0.76 to -0.15; P = 0.003), and overall KOOS (95% CI -29.48 to -23.17; P < 0.00001) were significantly greater at final follow-up when compared to baseline.

CONCLUSION

This meta-analysis found no significant differences in the tested MRI parameters, including MS, SI, and IIRMC. However, AC and AME worsened between baseline and final follow-up. Conversely, patients treated with PU meniscal scaffolds showed significant functional improvement and pain relief when compared with baseline scores. Thus, PU meniscal scaffolds appear to be a viable alternative for patients with partial meniscal defects, although further studies are needed to determine whether worsened AC and AME are clinically relevant. In particular, precise measurement of PU meniscal scaffolds in combination with thorough investigation of the baseline articular cartilage status and meniscal defect size may be effective for pain relief or functional improvement in patients with PU meniscal scaffold implantation.

LEVEL OF EVIDENCE

III.

Transcriptome comparison of meniscus from patients with and without osteoarthritis

OBJECTIVE

To assess the impact of osteoarthritis (OA) on the meniscus by comparing transcripts and biological processes in the meniscus between patients with and without OA.

DESIGN

RNA microarrays were used to identify transcripts differentially expressed (DE) in meniscus obtained from 12 OA and 12 non-OA patients. The non-OA specimens were obtained at the time of arthroscopic partial meniscectomy. Real-time PCR was performed on selected transcripts. Biological processes and gene-networking was examined computationally. Transcriptome signatures were mapped with 37 OA-related transcripts to evaluate how meniscus gene expression relates to that of OA cartilage.

RESULTS

We identified 168 transcripts significantly DE between OA (75 elevated, 93 repressed) and non-OA samples (≥1.5-fold). Among these, CSN1S1, COL10A1, WIF1, and SPARCL1 were the most prominent transcripts elevated in OA meniscus, POSTN and VEGFA were most highly repressed in OA meniscus. Transcripts elevated in OA meniscus represented response to external stimuli, cell migration and cell localization while those repressed in OA meniscus represented histone deacetylase activity (related to epigenetics) and skeletal development. Numerous long non-coding RNAs (lncRNAs) were DE between the two groups. When segregated by OA-related transcripts, two distinct clustering patterns appeared: OA meniscus appeared to be more inflammatory while non-OA meniscus exhibited a "repair" phenotype.

CONCLUSIONS

Numerous transcripts with potential relevance to the pathogenesis of OA are DE in OA and non-OA meniscus. These data suggest an involvement of epigenetically regulated histone deacetylation in meniscus tears as well as expression of lncRNAs. Patient clustering based on transcripts related to OA in articular cartilage confirmed distinct phenotypes between injured (non-OA) and OA meniscus.

The risk of symptomatic knee osteoarthritis after arthroscopic meniscus repair vs partial meniscectomy vs the general population

OBJECTIVE

To compare consultation rate for knee osteoarthritis (OA) after meniscus repair, arthroscopic partial meniscectomy (APM), and in general population, respectively.

METHOD

We identified patients aged 16-45 years having had meniscus surgery due to traumatic meniscus tear in 1998-2010 in southern Sweden by a healthcare register. Patients were followed from surgery until a diagnosis of knee OA, relocation, death, or December 31st, 2015. We studied the consultation rate for knee OA compared to the general population.

RESULTS

We identified 2,487 patients diagnosed with traumatic meniscus tear (mean [SD] age 30.5 [8.6] years); 229 (9.2%) of them had had meniscus repair. The absolute risk of having consulted for knee OA during the study was 17% after APM, 10.0% after meniscus repair, and 2.3% in the general population. Hazard ratio (HR) (95% confidence interval (CI)) for knee OA after repair vs APM was: 0.74 (0.48, 1.15). Excluding cases with OA within 2 years post-surgery, yielded the HR of 0.51 (0.27, 0.96). The consultation rate for knee OA standardized to the general population was then 42 per 10,000 person-years (95% CI 12, 71) in the meniscus repair group, 118 per 10,000 person-years (95% CI 101, 135) after APM, and 20 per 10,000 person-years (95% CI 19.9, 20.1) in the general population.

CONCLUSION

The point estimates suggests about 25-50% lower risk of consultation for knee OA after meniscus repair as compared to APM. However, the consultation rate for knee OA after repair was still at least two times higher as compared to the general population.

Risk factors for radiographic progression of osteoarthritis after partial meniscectomy of discoid lateral meniscus tear

INTRODUCTION

Partial meniscectomy has been preferred in the treatment of discoid lateral meniscus (DLM) with tear, rather than total or subtotal meniscectomy, which could lead to late radiographic degenerative changes.

HYPOTHESIS

One or more risk factors contribute to radiographic progression of osteoarthritis after partial meniscectomy of DLM tear.

MATERIAL AND METHODS

Inclusion criteria were consecutive patients who underwent arthroscopic surgeries for DLM tear from January 2005 to December 2010 by one surgeon. Exclusion criteria were preoperative osteoarthritis with KL grade 3 or more, osteochondritis dissecans, minimal width of meniscal remnant less than 6mm after meniscectomy, meniscal repair of an unstable discoid meniscus, age over 60years, loss to follow-up for a minimum of 5years and simultaneous surgery on articular cartilage or anterior cruciate ligament. According to the KL grade at the last follow-up, all enrolled knees were sorted into no progression to knee osteoarthritis (KL grade 1 or 2 - NOA) and progression to osteoarthritis (KL grade 3 or 4 - POA) groups. Multivariate logistic regression was used to analyze the risk factors of high-grade osteoarthritis.

RESULTS

In comparison with NOA group (n=135) and POA group (n=67), prolonged symptom duration, increased relative percentage of DLM thickness (RPDT) and the presence of horizontal tear were significant risk factors. The presence of horizontal tear (P=0.048, adjusted OR=19.364) was the strongest predictor, compared with prolonged symptom duration (P=0.030, adjusted OR=1.150) and increased RPDT (P=0.003, adjusted OR=1.377).

DISCUSSION

Horizontal tear, prolonged symptom duration, and increased RPDT are significant risk factors for radiographic progression to high-grade osteoarthritis after partial meniscectomy of DLM tear with a minimum follow-up of 5years.

LEVEL OF EVIDENCE

III, case-control study.

Post-operative deformation and extrusion of the discoid lateral meniscus following a partial meniscectomy with repair

PURPOSE

The purpose of this study was to investigate the morphology of the discoid lateral meniscus sequentially following a partial meniscectomy with repair using magnetic resonance imaging (MRI).

METHODS

Nine patients with a symptomatic discoid lateral meniscus with a peripheral tear were enrolled in this study, and a partial meniscectomy with repair was performed arthroscopically. An MRI examination was performed 2 weeks after surgery (before weight bearing was permitted) and again 6 months after surgery (when sporting activities could resume). The width, height and distance of the discoid lateral meniscus were measured. The distance was defined as the distance between the edges of the discoid lateral meniscus and the tibia.

RESULTS

The width of the anterior, middle and posterior segments significantly decreased from 2 weeks to 6 months after surgery. The height of the middle and posterior segments significantly increased from 2 weeks to 6 months after surgery, whereas the height of the anterior segment did not significantly change. The distance of the anterior, middle and posterior segments significantly decreased from 2 weeks to 6 months after surgery.

CONCLUSION

The discoid lateral meniscus exhibited deformation and extrusion from 2 weeks to 6 months after a partial meniscectomy with repair. Therefore, the function of load transmission might not be maintained appropriately after surgery.

LEVEL OF EVIDENCE

IV.

Early in situ changes in chondrocyte biomechanical responses due to a partial meniscectomy in the lateral compartment of the mature rabbit knee joint

We determined the biomechanical responses of chondrocytes to indentation at specific locations within the superficial zone of cartilage (i.e. patellar, femoral groove, femoral condylar and tibial plateau sites) taken from female New Zealand white rabbits three days after a partial meniscectomy in the lateral compartment of a knee joint. Confocal laser scanning microscopy combined with a custom indentation system was utilized to image chondrocyte responses at sites taken from ten contralateral and experimental knee joints. Cell volume, height, width and depth changes, global, local axial and transverse strains and Young׳s moduli were determined. Histological assessment was performed and proteoglycan content from the superficial zone of each site was determined. Relative to contralateral group cells, patellar, femoral groove and lateral femoral condyle cells in the experimental group underwent greater volume decreases (p < 0.05), due to smaller lateral expansions (with greater decreases in cell height only for the lateral femoral condyle cells; p < 0.05) whereas medial femoral and medial tibial plateau cells underwent smaller volume decreases (p < 0.05), due to less deformation in cell height (p < 0.05). Proteoglycan content was reduced in the patellar (p > 0.05), femoral groove, medial femoral condyle and medial tibial plateau experimental sites (p < 0.05). The findings suggest: (i) cell biomechanical responses to cartilage loading in the rabbit knee joint can become altered as early as 3 days after a partial meniscectomy, (ii) are site-specific, and (iii) occur before alterations in tissue mechanics or changes detectable with histology.

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.

Midterm follow-up after implantation of a polyurethane meniscal scaffold for segmental medial meniscus loss: maintenance of good clinical and MRI outcome

PURPOSE

The preservation of meniscal structure and function after segmental meniscal loss is of crucial importance to prevent early development of osteoarthritis. Implantation of artificial meniscal implants has been reported as a feasible treatment option. The purpose of this study was to assess the clinical and magnetic resonance imaging (MRI) results 4 years after implantation of a polyurethane scaffold for chronic segmental medial meniscus deficiency following partial medial meniscectomy.

METHODS

Eighteen patients received arthroscopic implantation of an Actifit(®) polyurethane meniscal implant (Orteq Sports Medicine, London, UK) for deficiency of the medial meniscus. Patients were followed at 6, 12, 24, and 48 months. Clinical outcome was assessed using established patient-reported outcome scores (KOOS, KSS, UCLA Activity Scale, VAS for pain). Radiological outcome was quantified by MRI scans after 6, 12, 24, and 48 months evaluating scaffold morphology, tissue integration, and status of the articular cartilage as well as signs of inflammation.

RESULTS

Median patient age was 32.5 years (range 17-49 years) with a median meniscal defect size of 44.5 mm (range 35-62 mm). Continuing improvement of the VAS and KSS Knee and Function Scores could be observed after 48 months compared to baseline, whereas improvement of the activity level according to UCLA continued only up to 24 months and decreased from there on. The KOOS Score showed significant improvement in all dimensions. MRI scans showed reappearance of bone bruises in two patients with scaffold extrusion. No significant changes in the articular cartilage could be perceived.

CONCLUSION

Arthroscopic treatment for patients with chronic segmental meniscal loss using a polyurethane meniscal implant can achieve sustainable midterm results regarding pain reduction and knee function.

LEVEL OF EVIDENCE

IV.

Partial meniscectomy is associated with increased risk of incident radiographic osteoarthritis and worsening cartilage damage in the following year

OBJECTIVES

To assess whether partial meniscectomy is associated with increased risk of radiographic osteoarthritis (ROA) and worsening cartilage damage in the following year.

METHODS

We studied 355 knees from the Osteoarthritis Initiative that developed ROA (Kellgren-Lawrence grade ≥ 2), which were matched with control knees. The MR images were assessed using the semi-quantitative MOAKS system. Conditional logistic regression was applied to estimate risk of incident ROA. Logistic regression was used to assess the risk of worsening cartilage damage in knees with partial meniscectomy that developed ROA.

RESULTS

In the group with incident ROA, 4.4 % underwent partial meniscectomy during the year prior to the case-defining visit, compared with none of the knees that did not develop ROA. All (n = 31) knees that had partial meniscectomy and 58.9 % (n = 165) of the knees with prevalent meniscal damage developed ROA (OR = 2.51, 95 % CI [1.73, 3.64]). In knees that developed ROA, partial meniscectomy was associated with an increased risk of worsening cartilage damage (OR = 4.51, 95 % CI [1.53, 13.33]).

CONCLUSIONS

The probability of having had partial meniscectomy was higher in knees that developed ROA. When looking only at knees that developed ROA, partial meniscectomy was associated with greater risk of worsening cartilage damage.

KEY POINTS

• Partial meniscectomy is a controversial treatment option for degenerative meniscal tears. • Partial meniscectomy is strongly associated with incident osteoarthritis within 1 year. • Partial meniscectomy is associated with increased risk of worsening cartilage damage.

Weekly injections of Hylan G-F 20 delay cartilage degeneration in partial meniscectomized rat knees

Background

Cross-linked hyaluronan—also called Hylan G-F 20—is a medical device developed to treat osteoarthritis of the knee. However, it is still controversial whether Hylan G-F 20 has a cartilage protective effect in trauma-induced osteoarthritis. We investigated whether Hylan G-F 20 delayed osteoarthritis progression in a partial meniscectomized rat model.

Methods

Lewis rats were used for the experiments. The anterior medial meniscus was resected at the level of the medial collateral ligament in both knees. From 1 week after the surgery, 50 μl of Hylan G-F 20 was injected weekly into the left knee and phosphate buffered saline was injected into the right knee. Cartilage was evaluated for macroscopic findings, histology with safranin-o, and expression of type II collagen at 2, 4, and 8 weeks. Synovitis was also evaluated, and immunohistochemical analysis was performed for ED1.

Results

Macroscopic findings demonstrated that India ink positive area, representing fibrillated cartilage, was significantly smaller in the Hylan G-F 20 group than in the control group at 2, 4, and 8 weeks (n = 5). There were no significant differences in osteophyte score between the Hylan G-F 20 group and the control group at 2, 4, and 8 weeks.

Histologically, the cartilage in the medial tibial plateau was destroyed at 8 weeks in the control group, while type II collagen expression was still observed at 8 weeks in the Hylan G-F 20 group. OARSI score for cartilage histology was significantly lower in the Hylan G-F 20 group than in the control group at 4 and 8 weeks (n = 5). There were no significant differences in synovial cell number or modified synovitis score between the Hylan G-F 20 group and the control group at 2, 4, and 8 weeks (n = 5). In the Hylan G-F 20 group, foreign bodies surrounded by ED1 positive macrophages were observed in the synovium.

Conclusion

Weekly injections of Hylan G-F 20 starting 1 week after surgery delayed cartilage degeneration after meniscectomy in a rat model. Synovitis induced by meniscectomy was not alleviated by Hylan G-F 20. Insoluble gels were observed in the synovium after the Hylan G-F 20 injection.

Actifit® scaffold implantation: Influence of preoperative meniscal extrusion on morphological and clinical outcomes

BACKGROUND

Meniscal substitutes have been suggested for the treatment of knee pain after partial meniscectomy. However, despite the partial nature of the initial meniscectomy, secondary extrusion of the substitute is common. The primary objective of this study was to evaluate morphological outcomes of meniscal substitute implantation and their potential associations with preoperative meniscal extrusion.

HYPOTHESIS

Preoperative absolute meniscal extrusion in the coronal plane predicts poorer morphological and clinical outcomes.

MATERIAL AND METHODS

Consecutive patients who received an Actifit(®) meniscal substitute between 2008 and 2011 were included prospectively. After 1 year and 2 years, the IKDC score and KOOS were determined and magnetic resonance imaging performed. The morphological evaluation consisted in measuring meniscal extrusion and cartilage coverage by the substitute in the coronal and sagittal planes.

RESULTS

Twenty patients were included. Among them, 3 required subsequent removal of the substitute. The mean subjective IKDC score increased from 48.1 preoperatively to 56.4 after 2 years. Over the same period, the function/sports/recreational activities component of the KOOS improved significantly (42.9 vs. 55.0, P=0.04). Positive correlations between preoperative and 1-year values were demonstrated for both cartilage coverage in the coronal and the sagittal planes (P=0.03 and P=0.04, respectively) and coronal absolute meniscal extrusion (P=0.05). No significant differences were found between preoperative and 2-year values of cartilage coverage in the coronal and sagittal planes (P=0.38). There was a negative correlation linking preoperative meniscal extrusion in the coronal plane to 1-year cartilage coverage in the coronal and sagittal planes (P=0.01 and P=0.04, respectively). Preoperative absolute meniscal extrusion in the coronal plane correlated negatively with the subjective IKDC score after 1 year (P=0.02).

DISCUSSION

Preoperative meniscal extrusion in the coronal plane strongly predicts clinical and morphological outcomes. Marked preoperative meniscal extrusion, even in a patient with symptoms after partial meniscectomy, should prompt an appraisal of whether allograft replacement may be more appropriate than a meniscal substitute.

LEVEL OF EVIDENCE

IV, prospective study.

Meniscoplasty for lateral discoid meniscus tears: Long-term results of 14 cases

INTRODUCTION

Discoid lateral meniscus lesions are relatively rare. The objective of this study was to determine the long-term results of 14 cases of discoid lateral meniscus tears treated by arthroscopic meniscoplasty between July 1991 and May 2009, and to assess the development of osteoarthritis in the lateral compartment.

METHODS

The series consisted of 10 patients (14 knees): 3 girls under the age of 15, 3 men and 4 women aged from 16 to 47 years (mean age: 31.4±11.1 years). The main reason for consultation was pain in 10 cases, locking in 2 cases and pain associated with locking in 2 cases. The diagnosis was confirmed preoperatively by MRI in 10 cases, CT-arthrography in 1 case and arthrography in 3 cases. The indication for surgery was made because of a symptomatic discoid lateral meniscus. All cases were treated by arthroscopic meniscal reshaping. Functional results were evaluated using the Lysholm-Tegner, IKDC, KOOS and satisfaction scores. Radiological results were evaluated based on the modified Alhbäck classification for osteoarthritic (OA) changes.

RESULTS

No complications were found. Two patients were lost to follow-up. The remaining eight patients (12 knees) were reviewed at a mean of 157.5±72.1 months (61-276). The mean Lysholm-Tegner score was 88.9±10.6 points (67-100), the mean KOOS was 92.4±9.5 (65-100) and the mean IKDC score was 85.4±16.5 points (65-100). All eight of the reviewed patients were satisfied or very satisfied with the result. Radiological analysis found that five knees had no signs of OA, five knees had stage 1, one had stage 2 and one had stage 3. At last follow-up, no patient had been reoperated.

CONCLUSION

Meniscoplasty of discoid lateral meniscus tears leads to excellent long-term functional results despite signs of osteoarthritic changes in the lateral compartment of the knee.

LEVEL OF EVIDENCE

IV (retrospective study).

Is formal decompression necessary for parameniscal cysts associated with meniscal tears?

BACKGROUND

Meniscal tears and associated parameniscal cysts have good outcomes after partial meniscectomy and cyst evacuation. Good outcomes have been noted after partial meniscectomy with recurrent cysts. This investigation asks if partial meniscectomy without meniscal cyst decompression is sufficient for positive patient outcome.

METHODS

Sixteen patients treated between 2005 and 2010 for a meniscal cyst and concomitant meniscal tear. Inclusion criteria were meniscal tear and parameniscal cyst per MRI, no prior surgery on the affected knee, and Outerbridge classification of I/II. Two patients were excluded. Fourteen patients completed the study until final follow-up. Lysholm knee scores were documented at 6 months post-operatively and at final follow-up. Re-evaluation or second surgery of the treated knee was documented.

RESULTS

Eight lateral cysts and six medial cysts were diagnosed. Eight cysts were associated with a horizontal cleavage tear, while six menisci had a complex tear with a horizontal cleavage component. The average cyst size was 1.3 cm (0.5 to 3.5) at the largest diameter. At 6 months, the average Lysholm knee score was 94.1. At mean 5 years, the average score was 89.1. Patients with medial cysts, cysts greater than 1.0 cm, horizontal cleavage tears, or without simultaneous chondroplasty scored higher in the short and medium-term than their respective counterparts.

CONCLUSIONS

Excellent short and medium-term outcomes can be achieved following partial meniscectomy without cyst decompression for patients with meniscal cysts and associated meniscal tears.

LEVEL OF EVIDENCE

Level IV.

A new surgical technique of arthroscopic partial meniscectomy for unstable inferior leaf of the anterior horn in a horizontal tear of lateral meniscus

We introduce a new arthroscopic partial meniscectomy technique using a three portals and a small skin hook retractor to remove unstable inferior leaf in horizontal meniscal tear that involved the anterior portion of the lateral meniscus. The patient is positioned for a standard knee arthroscopy. After careful estimation of the depth and extent of the cleft and stability of the superior and inferior leaves is done through the standard anteromedial portal, a small skin hook retractor is inserted through the standard anterolateral portal to raise the dominant superior leaf of anterior horn, then the unstable inferior leaf is excised with a 90° rotary punch and a motorized shaver through the extreme far anteromedial portal. This technique is useful method to remove unstable inferior leaf of anterior horn of lateral meniscus which is difficult to remove with a standard technique.