Partial meniscectomy provides no benefit for symptomatic degenerative medial meniscus posterior root tears

Weight loss enhances meniscal healing following transtibial pullout repair for medial meniscus posterior root tears

PURPOSE

This study investigated the impact of weight change on the success of transtibial pullout repair for medial meniscus (MM) posterior root tears (MMPRTs).

METHODS

The study included 129 patients diagnosed with MMPRTs who had undergone transtibial pullout repair. The patients were screened between July 2018 and November 2021. Patient-reported outcomes were assessed preoperatively and at 12 months postoperatively using the Knee injury and Osteoarthritis Outcome Score (KOOS). MM extrusion (MME) and ΔMME (postoperative MME - preoperative MME) were calculated preoperatively and at 12 months postoperatively using magnetic resonance imaging.

RESULTS

Patients were divided into weight loss (body mass index [BMI] decrease of at least 0.5 kg/m2 after primary repair; n = 63) and weight gain (BMI increase of at least 0.5 kg/m2 ; n = 66) groups. Both groups had similar demographic variables and preoperative clinical scores; patient-reported outcomes significantly improved postoperatively. The weight loss group had significantly greater improvement in KOOS-quality of life (weight loss, 29.4 ± 23.7; weight gain, 23.9 ± 27.6; p = 0.034), lower postoperative MME (weight loss, 3.9 ± 1.7 mm; weight gain, 4.2 ± 1.2 mm; p = 0.043) and lower ΔMME (weight loss, 0.8 ± 0.8 mm; weight gain, 1.2 ± 0.9 mm; p = 0.002) than the weight gain group. Total arthroscopic healing scores (weight loss, 7.6 ± 1.0; weight gain, 7.2 ± 1.5; p = 0.048) and associated subscales, including anteroposterior bridging tissue width (weight loss, 4.0 ± 0.0; weight gain, 3.8 ± 0.7; p = 0.004) and MM posterior root stability (weight loss, 2.6 ± 0.7; weight gain, 2.4 ± 0.7; p = 0.041), significantly differed between the groups.

CONCLUSIONS

Weight loss was associated with better meniscal healing and less MME progression after MMPRT repair, highlighting the significance of weight management in individuals undergoing meniscal surgery. These findings provide valuable insights into the clinical significance of weight loss in the success of transtibial pullout repair for MMPRTs.

LEVEL OF EVIDENCE

Level III.

Medial joint space narrowing progresses after pullout repair of medial meniscus posterior root tear

PURPOSE

The extent to which arthropathic changes progress after medial meniscus posterior root tear (MMPRT) repair remains controversial. This retrospective study assessed medial joint space (MJS) narrowing progression after pullout repair for MMPRT and identified the correlating factors.

METHODS

We included 56 patients who underwent pullout repair for MMPRT. The MJS of the bilateral knees was assessed with radiography using the fixed-flexion view. A second-look arthroscopy was performed one year post-operatively for all patients. The baseline characteristics, clinical scores, Kellgren-Lawrence (KL) grade, and medial meniscus extrusion (MME) were identified. Statistical comparisons and correlation analyses were conducted.

RESULTS

The MJS narrowing width was significantly larger in MMPRT knees than in contralateral knees (0.51 ± 0.85 mm vs. 0.09 ± 0.49 mm, p < 0.001). KL grade progression was observed in 23.2% (13/56) of patients. There was a significant difference between pre- and post-operative MME values, indicating MME progression (p < 0.001). Each clinical score showed significant improvement one year post-operatively (p < 0.001). Positive correlations were found between MJS narrowing and pre-operative MJS (coefficient = 0.510, p < 0.001), rate of change in MJS (coefficient = 0.929, p < 0.001), and increase in MME (ΔMME) (coefficient = 0.506, p < 0.001).

CONCLUSION

Knees that underwent pullout repair for MMPRT showed progression of MJS narrowing by 0.51 mm at one year post-operatively, although clinical scores markedly improved. Correlating factors for MJS narrowing were pre-operative MJS, rate of change in MJS, and ΔMME. Preventing MME progression is essential for preventing arthropathic changes.

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.

Trans-Posterior Cruciate Ligament All-Inside Root Repair Versus Partial Meniscectomy for Medial Meniscus Posterior Root Tears: Comparison of Semiquantitative and Quantitative MRI Outcomes in Cartilage Degeneration and Osteoarthritic Progression

OBJECTIVE

To perform conventional, morphological, and T2 mapping compositional MRI imaging to assess the cartilage degeneration and osteoarthritic progression in patients with medial meniscus posterior root tears (MMPRTs) who underwent trans-posterior cruciate ligament (PCL) all-inside repair or partial meniscectomy.

DESIGN

Patients with MMPRTs after trans-PCL all-inside repair (group AR) or partial meniscectomy (group PM) between 2015 and 2018 were retrospectively identified. Preoperative and postoperative conventional MRI were collected to assess medial meniscus extrusion (MME) and the whole-organ magnetic resonance imaging score (WORMS). Postoperative morphological MRI and T2 mapping compositional MRI were collected to evaluate the quantitative cartilage thickness/volume and cartilage composition.

RESULTS

The final cohort consisted of 21 patients in group AR and 22 patients in group PM, with no differences in demographic data and baseline patient characteristics between the 2 groups. Group AR demonstrated less progression of articular cartilage wear (P < 0.05) and decreased meniscal extrusion (P = 0.008) than group PM at the final follow-up. In addition, group AR demonstrated less extracellular matrix degeneration in the cartilage subregion of the medial compartment (P < 0.05) than group PM with lower T2 relaxation times in the superficial layer of the articular cartilage.

CONCLUSION

Trans-PCL all-inside repair of MMPRTs could delay the initial cartilage deterioration and morphological cartilage degeneration compared with partial meniscectomy. However, the amount of residual meniscal extrusion is clinically important, and an improved root repair fixation method should be investigated.

ICRS scores worsen between 2-year short term and 5-year mid-term follow-up after transtibial medial meniscus root repair despite maintained functional outcomes

PURPOSE

The purpose of this study was to evaluate the mid-term results of posterior medial meniscal root tear (PMMRT) repair through assessment of functional outcome scores and magnetic resonance imaging (MRI).

METHODS

This was a single-center, retrospective study evaluating patients that had undergone a PMMRT. This was a follow-up to a previously published 2-year outcome study (all original patients were invited to participate). Clinical outcomes included pre- and postoperative International Knee Documentation Committee (IKDC) and Lysholm scores. Root healing, meniscal extrusion, and cartilage degeneration via International Cartilage Repair Society Scale (ICRS) grades were assessed on MRI by two musculoskeletal fellowship-trained radiologists.

RESULTS

10 of the original study's 18 patients were able to participate. Mean age and BMI was 48.4 ± 12.0 years and 29.5 ± 4.5, respectively, with mean follow-up 65.5 ± 8.3 months (range 52.0-75.8) (60% female). The IKDC significantly increased from 43 ± 13 preoperatively to 75 ± 16 at 5-year follow-up (p < 0.001). There was no significant change in IKDC score between 2-year and 5-year follow-up [75 ± 16 vs 73 ± 20, (n.s)]. The Lysholm also significantly increased between preoperative and 5-year follow-up (49 ± 7 vs 84 ± 11, p < 0.001). There was no significant change between Lysholm score at 2-year and 5-year follow-up [84.0 ± 11 vs 82 ± 13, (n.s)]. Mean extrusion did not significantly change from the preoperative state to 5-year follow-up [4.80 mm ± 1.9 vs 5.0 mm ± 2.5, (n.s.)]. Extrusion also did not significantly change between 2-and 5-year follow-up [6.1 ± 3.2 mm vs 5.0 mm ± 2.5, (n.s.)]. No patients with > 3 mm of extrusion on preoperative MRI had < 3 mm of extrusion on postoperative MRI. Both medial femoral condyle and medial tibial plateau ICRS grades significantly increased from preoperative to 2-year follow-up (p = 0.038, p = 0.023, respectively). Medial femoral condyle and medial tibial plateau ICRS grades again significantly increased between 2-year and 5-year follow-up (p = 0.014, p = 0.034).

CONCLUSION

Patients treated with the transtibial suture pullout technique with two locking cinch sutures had maintenance of clinical outcome improvements at 5-year follow-up. However, extrusion was widely prevalent, with worsening progression of femoral and tibial chondral disease.

LEVEL OF EVIDENCE

Level 4.

Non-anatomic repair of medial meniscus posterior root tears to the posterior capsule provided favourable outcomes in middle-aged and older patients

PURPOSE

To describe a non-anatomic arthroscopic all-inside repair technique for middle-aged and older patients with medial meniscus posterior root tears (MMPRTs) and to evaluate the short- to mid-term clinical and radiologic results. The hypothesis was that this procedure would yield good clinical outcome results and structural healing in middle- and older-aged patients.

METHODS

This was a retrospective study evaluating patients who had undergone MMPRT repair by suturing the meniscal root directly to the capsule, rather than by the transtibial technique, between 2013 and 2016. This all-inside repair technique was performed for patients with type II MMPRTs who were over 40 years old. Exclusion criteria included tibial osteotomy due to malalignment, concomitant multiple-ligament injuries and follow-up time less than 2 years. The Lysholm score, Tegner activity score and International Knee Documentation Committee (IKDC) score were evaluated preoperatively and at the final follow-up. Medial meniscal extrusion, the International Cartilage Repair Society (ICRS) grades of the medial compartment, and the healing status of the medial meniscus root were assessed on magnetic resonance imaging preoperatively and at the final follow-up.

RESULTS

Twenty-nine patients (mean age 61.7 ± 7.9) were included; the mean follow-up duration was 46.2 ± 7.9 months. The mean Lysholm score significantly improved from 33.7 ± 20.9 preoperatively to 81.7 ± 19.9 at the final follow-up (p < 0.001), the median Tegner activity score improved from 1.0 (range 1-4) to 3.0 (range 2-4, p < 0.001), and the mean IKDC score improved from 20.1 ± 16.4 to 69.6 ± 16.2 (p < 0.001). On MRI, 9 (31%) cases had complete healing; 17 (59%) had partial healing; and 3 (10%) had failed healing (ICCs ≥ 0.92). Mean meniscal extrusion significantly increased from 2.3 ± 1.7 mm preoperatively to 3.5 ± 1.5 mm postoperatively (p < 0.001, ICCs ≥ 0.92).

CONCLUSION

Non-anatomic arthroscopic all-inside repair of MMPRTs to the posterior capsule yielded good to excellent clinical results and a high rate of healing in the medial meniscus root on MRI in middle-aged and older patients at short- to mid-term follow-up, despite increased meniscal extrusion. This method is an alternative to the transtibial pullout repair technique for treating MMPRTs in middle- and older-aged patients.

LEVEL OF EVIDENCE

Level IV.

Preoperative varus alignment and postoperative meniscus extrusion are the main long-term predictive factors of clinical failure of meniscal root repair

PURPOSE

No studies have been conducted to determine long-term predictors of clinical failure after surgical root repair. This study identified long-term prognostic factors of clinical failure after pull-out repair of medial meniscus posterior root tears (MMPRTs) at a minimum of 10 year follow-up.

METHODS

A total of 37 patients who underwent MMPRT pull-out repair and had been observed for more than 10 years were recruited for this study. The mean follow-up period was 125.9 ± 21.2 months. Clinical failure of the procedures was defined as conversion to total knee arthroplasty (TKA). Participants were categorized into two groups: non-failure and failure groups. Various factors, including demographic features and radiologic findings, were analyzed and compared between the two groups. Meniscus extrusion was assessed at coronal magnetic resonance imaging preoperatively and 1 year postoperatively. Independent risk factors were determined by univariate analysis and logistic regression analysis. To determine the cut-off value for risk factors, the receiver-operating characteristic curve analysis was performed.

RESULTS

In total, eight patients (22%) were converted to TKA during the follow-up period. With univariate analysis, statistically significant differences between two groups were observed in mechanical varus alignment (P = 0.018), rate of the number of patient with more meniscal extrusion values after surgery (P = 0.024), and the difference between the preoperative and 1-year postoperative value of meniscus extrusion (mm) (P = 0.010). In a logistic analysis, OR of mechanical varus alignment and differences in meniscus extrusion value before and 1 year after surgery was 1.5 (P = 0.048) and 3.7 (P = 0.034). The cut-off values of mechanical varus alignment and differences in meniscus extrusion values were 5 degrees and 0.7 mm.

CONCLUSION

Clinically, preoperative varus alignment and increased meniscal extrusion after surgery were found to be predictive for a clinical failure after meniscal root repair in a long-term perspective. Thus, these negative prognostic factors should be taken into consideration for performing root repair in MMPRTs.

LEVEL OF EVIDENCE

Level III.

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

BACKGROUND

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

PURPOSE/HYPOTHESIS

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

STUDY DESIGN

Controlled laboratory study.

METHODS

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

RESULTS

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

CONCLUSION

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

CLINICAL RELEVANCE

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

Improvement of clinical and radiological outcomes of root repair patients with advanced articular cartilage degeneration and osteoarthritis

PURPOSE

The main purpose of this study was to investigate clinical and radiological outcomes of medial meniscus posterior root tear (MMPRT) repair in knees with advanced articular cartilage degeneration and osteoarthritis compared to those with minimal degenerative change.

METHODS

Thirty-three knees underwent MMPRT repair using an arthroscopic pullout repair tibial tunnel technique. Clinical scores including Lysholm Score, International Knee Documentation Committee (IKDC) Score and Knee injury and Osteoarthritis Outcome (KOOS) Score were collected preoperatively and sequentially at 6 months, 12 months and mean final follow-up of 39.4 months. Kellgren-Lawrence (K-L) osteoarthritis grade, Outerbridge classification of cartilage degeneration and the presence of bone marrow oedema on MRI were also evaluated.

RESULTS

All clinical scores improved at final follow-up for knees with K-L grade ≥ 2 osteoarthritis (p < 0.001), with no significant difference compared to K-L 0/1. Patients with Outerbridge class 3/4 cartilage degeneration also reported improvements in clinical scores, albeit lower than those with class 2 degeneration (p < 0.05). During recovery, the majority of patients reported clinical improvements by 6 months, and six patients further improved by at least 15 points in IKDC score between 6 and 12 months. Osteoarthritis progressed in 10 of 31 knees (32%), with an overall mean pre-operative K-L grade of 1.6 ± 0.9 compared to 2.0 ± 0.9 at final follow-up (n.s.). No knees progressed to K-L 4 or underwent re-operation. Pre-operative bone marrow oedema was present in 17 knees (52%), all of which had signal localised to the medial tibia or femur. Oedema had resolved in all but 5 knees post-operatively (p < 0.01).

CONCLUSION

Arthroscopic repair of medial meniscus posterior root tears is associated with improved outcomes in knees with advanced cartilage degeneration and osteoarthritis. Meaningful improvements in clinical outcomes can be achieved beyond 6 months, thus success of the operation is best determined at the 12-month mark. Oedema signal significantly improved post-operatively, however a relatively high proportion of knees had K-L progression.

LEVEL OF EVIDENCE

IV - Case Series.

Correlation of Femoral Trochlear Dysplasia With Anterior Cruciate Ligament Injury in Skeletally Immature Patients

Background

Reports of anterior cruciate ligament (ACL) injury in patients with skeletal immaturity have been increasing. Variations in knee joint anatomy have been linked to ACL injury risk factors.

Purpose

To identify associations between ACL injury, patella alta, and femoral trochlear dysplasia in patients with skeletal immaturity by using magnetic resonance imaging (MRI).

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

This retrospective study included 231 patients with skeletal immaturity-116 with acute complete noncontact ACL injury and 115 without ACL injury (controls)-who underwent knee MRI. Cases of femoral trochlear dysplasia were divided into 4 types according to the Dejour classification scheme. Patellar height and patellar tendon length were measured via sagittal MRI, and the Insall-Salvati ratio (ISR) was calculated.

Results

In the ACL injury group, 56 (48.3%) knees exhibited trochlear dysplasia, including 51 (91.1%) that were Dejour type A; and in the control group, 12 (10.4%) knees exhibited trochlear dysplasia, 12 (100%) Dejour type A. The prevalence of femoral trochlear dysplasia was significantly higher in the ACL injury group than in the control group (P < .001). The ISR was not significantly different between the ACL injury and control groups (0.9 ± 0.2 vs 1 ± 0.2 mm; P = .16). The correlation between ISR >1.2 and presence of ACL injury was not significant.

Conclusion

Femoral trochlear dysplasia was associated with ACL injury in patients with skeletal immaturity. In particular, Dejour type A femoral trochlear dysplasia was correlated with ACL injury patients with skeletal immaturity. Also, the possibility of ACL damage exists in patients with skeletal immaturity and femoral trochlear dysplasia.

Transtibial pullout repair of medial meniscus posterior root tears: effects on the meniscus healing score and ICRS grade among patients with mild osteoarthritis of the knee

PURPOSE

To assess the effects of transtibial pullout repair for medial meniscus posterior root tears (MMPRTs) among patients with early osteoarthritis of the knee as measured by the meniscus healing score and to determine whether the meniscus healing score correlates with the International Cartilage Repair Society (ICRS) grade progression.

METHODS

Forty-seven patients with mild osteoarthritic knees (Kellgren-Lawrence grade ≤ 2 and varus alignment < 5°) who underwent transtibial pullout repair less than 3 months after MMPRT onset were assessed. The association between meniscus healing scores at 1 year postoperatively and cartilage damage of the medial compartment (medial femoral condyle [MFC] and medial tibial plateau [MTP]) were evaluated. The MFC was divided into six zones (A to F) and the MTP into two zones (G and H). The mean ICRS grade for each zone was compared between the primary surgery and second-look arthroscopy. The correlation between cartilage damage and meniscus healing status at the time of second-look arthroscopy in each zone was analysed.

RESULTS

The mean time interval from injury to surgery was 63 days, and all clinical scores showed significant improvement. There were no significant differences in the extent of cartilage damage in areas B, C, E, or F (n.s.) for MFC or in areas G and H (n.s.) for MTP. The meniscus healing score and cartilage damage were correlated in the loading areas (B, C, E, and H; - 0.53, - 0.45, - 0.33, and - 0.38, respectively; p < 0.05).

CONCLUSION

Transtibial pullout repair of MMPRTs among patients with mild osteoarthritic knees improved the clinical outcomes and showed a negative correlation between high meniscus healing scores and ICRS grades in the medial compartment loading area. This study suggests that early surgery should be undertaken for patients with mild osteoarthritic knee who develop MMPRTs.

LEVEL OF EVIDENCE

Level IV.

Does meniscectomy have any advantage over conservative treatment in middle-aged patients with degenerative medial meniscus posterior root tear?

Background

The best treatment for degenerative medial meniscus posterior root tear (MMPRT) remains controversial. This study aimed to compare the clinical and radiological outcomes of arthroscopic meniscectomy and conservative treatment for degenerative MMPRT.

Methods

From January 2007 to December 2014, 146 patients (Meniscectomy group, 90; Conservative group, 56) were evaluated. Clinical outcomes were assessed using the Visual Analog Scale, International Knee Documentation Committee subjective scoring scale, Tegner activity scale, and Lysholm knee scoring scale at the final follow-up. Radiologic outcomes evaluated the progression of osteoarthritis (OA) according to the Kellgren-Lawrence (K-L) classification. We compared the hip-knee-ankle angle (HKAA), medial proximal tibial angle, tibial posterior slope angle, and width of medial joint space. After an average follow-up of 6.3 years, the survivorship was analyzed using the Kaplan–Meier method.

Results

All clinical outcomes were significantly improved in both groups after treatment, with no significant differences between the two groups at the final follow-up. The progression of OA according to the K-L classification, HKAA and width of medial joint space was significantly advanced in the meniscectomy group (p = 0.03, 0.04, 0.03, respectively). The 10-year survival rates in the meniscectomy and conservative groups were 87 and 88%, respectively.

Conclusions

This study demonstrated that both conservative treatment and meniscectomy provided symptomatic relief. However, it was confirmed that OA progression was more severe in the meniscectomy. We conclude that arthroscopic meniscectomy had no advantage over conservative treatment in terms of clinical outcomes and OA progression in middle-aged patients with MMPRT.

Level of evidence

Level III; retrospective comparative study.

Arthritic progression secondary to meniscus root tear treated with knee arthroplasty demonstrates similar outcomes to primary osteoarthritis: a matched case-control comparison

PURPOSE

There is limited data comparing the outcomes of knee arthroplasty for arthritis secondary to meniscus root tear versus primary osteoarthritis. The aim of this 2:1 matched case control series was to compare outcomes in patients who underwent arthroplasty for arthritis following a meniscus root tear (root tear cohort-"RTC") with a control group of patients with primary osteoarthritis (primary osteoarthritis-"controls"). The authors hypothesized that the meniscus root tear patients would have similar clinical outcomes, return to activity, complication and reoperation rates as their matched controls.

METHODS

A consecutive series of patients who had a clinically and radiographically confirmed meniscus root tear between 2002 and 2017 at a mean 4.8 year follow-up that developed secondary arthritis were matched 2:1 by laterality, surgery, age at surgery, date of surgery, sex, and surgeon to a control group of patients with primary osteoarthritis, without a root tear, who underwent arthroplasty. No patients were lost to follow-up. Patient demographics, Kellgren-Lawrence grades at the time of surgery, pre- and post-operative Knee Society Score pain and function scores, Tegner score, complications, and survival free of reoperation were analyzed between groups.

RESULTS

A total of 225 subjects were identified, including 75 root tear cohort patients (13 UKA, 62 TKA) and 150 control patients. The root tear cohort had significantly lower Kellgren-Lawrence grades than the control group at the time of arthroplasty (p ≤ 0.001), but similar baseline pre-operative Knee Society Score pain, Knee Society Score function, and Tegner activity scale score. Post-operatively, Knee Society Score pain scores were comparable, and root tear cohort Knee Society Score function scores statistically significantly improved (p ≤ 0.007). Complication rates and survival free of reoperation at final follow-up were not statistically significantly different between groups.

CONCLUSION

Patients treated with arthroplasty for secondary arthritis after a meniscus root tear demonstrated less severe radiographic arthritis, but similar pre-operative pain levels compared to matched controls with primary osteoarthritis. The root tear cohort patients demonstrated improved outcomes with respect to function, and similar outcomes with respect to pain, activity level, complication rates, and reoperation rates. The authors conclude that arthroplasty can be a reliable option for selected patients with an irreparable root tear and ongoing pain and dysfunction refractory to non-operative management, even in the setting of less advanced osteoarthritis on X-ray.

LEVEL OF EVIDENCE

III.

Gender-Based Quantitative Analysis of the Grand Piano Sign in Mechanically Aligned Total Knee Arthroplasty in Asians

In mechanically aligned (MA) total knee arthroplasty (TKA), the grand piano sign helps surgeons to further ensure the proper external rotation of the femoral component. The goal of this study was to determine the sex-related differences in the shape of the anterior resection surface using 3D magnetic resonance imaging (MRI) models. MRI scans were performed on 267 consecutive patients (202 women and 65 men) with osteoarthritis who underwent TKA in order to reconstruct a 3D model. Virtual anterior condylar resection was performed based on the surgical transepicondylar axis (sTEA), Whiteside's line (WSL), and flexion-extension axis (FEA). On the anterior resection surface, both lateral length (LatL) and medial length (MedL) were measured, and the ratio between the two (MedL/LatL) was calculated. The mediolateral width of the distal femur (ML) and anterior resection surface (M'L') were measured, and the ratio between the M'L' and ML (M'L'/ML) was calculated. Both the lateral deviation (LD) and the ratio between LD and ML (LD/ML) were also determined. Morphological classification of the anterior resection surface was conducted based on the presence of a definite medial peak. When based on the sTEA or WSL, the MedL/LatL of female subjects was significantly greater than that of male subjects (p < 0.001 and p < 0.05, respectively). The MedL/LatL of the FEA was consistently larger than that obtained using the sTEA or WSL. Among female subjects, the MedL/LatL of the sTEA was significantly greater than that of the WSL, although this was not the case in either the total study population or the male subjects alone. When based on the sTEA, the M'L'/ML was statistically greater in the female subjects (p < 0.01). The LD was greater in the male subjects (p < 0.01), but there was no difference between the male and female subjects when comparing the LD/ML (p = 0.93). The proportion of double- and single-peak types was not significantly different between the sexes (p = 0.196). Surgeons should be aware that the shape of the anterior resection surface may differ depending on the sex of the patient. The results of this study provide more consistent surgical outcomes as well as fundamental anatomical data for designing suitable prostheses applicable to the Korean population.

Anatomic Differences in the Sagittal Knee Joint Are Associated With ACL Injury: Results From a Skeletally Immature Korean Population

Background:

Differences in tibiofemoral articular morphology are associated with risks of anterior cruciate ligament (ACL) injury.

Purpose:

To determine whether bony and cartilaginous morphological characteristics are related to ACL injury in pediatric patients and to investigate any differences according to sex.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A total of 200 skeletally immature Korean patients from a single institution were included in this study; 100 patients had an ACL injury, and 100 had an intact ACL. Condylar morphology and tibial slopes were evaluated and compared between the groups, and differences between sexes were evaluated in the ACL-injured group.

Results:

The lateral femoral curvature was significantly greater and the lateral and medial tibial curvatures were significantly smaller in the ACL-injured group than in the intact group (P < .01 for all). In addition, the lateral and medial femoral curvatures as well as the lateral tibial curvature were significantly smaller in female than in male patients (P < .01 for all). Both the medial and lateral tibial slopes were greater in the ACL-injured versus intact group (medial slope, 5.5° vs 5.0°; lateral slope, 3.0° vs 1.3°, respectively); this difference was statistically significant for lateral tibial slope (P = .026). No sex-based differences were found for medial or lateral tibial slope.

Conclusion:

Femoral and tibial curvatures as well as lateral tibial slope were significantly different between the ACL-injured and ACL-intact patients, and the lateral tibial curvature was significantly smaller in female than in male patients. Medial and lateral tibial slopes were not associated with a significant difference in ACL injury between male and female patients.

Meniscal Root Repair Along with Auxiliary Procedures for Joint Preservation: Current Concepts

Meniscal root repair and joint preservation surgeries have gained increased interest in the last decade, from a better interpretation of the role of meniscal functions, from the biomechanical studies. Several published results from both biomechanical and clinical studies has proven the effectiveness of meniscal root repairs and has led to a unanimous international consensus for the need for root repair surgery. Meniscal repair by suture pull-out technique is widely followed around the world and leads to adequate healing and good clinical outcome. There are auxiliary procedures like centralization sutures (to reduce the meniscal extrusion), high tibial osteotomy, cartilage repair procedures, meniscal root reconstruction and ligament reconstructions are performed along with meniscal root repair, especially in the younger patients and recently sub-chondroplasty for the bone marrow lesions (BMLs) are also executed. This review article discusses the anatomy, types of root tears, evaluation, treatment, outcomes of root repair, and the need for additional procedures, which are imperative for joint preservation and restoration of the biomechanics of the knee.

Medio-Lateral and Flexion-Extension Gap Imbalances in Mechanically Aligned Total Knee Arthroplasty Using Measured Resection Technique in Korean Patients: 3D Simulation

Background: It is well known that the measured resection (MR) technique in mechanically aligned (MA) total knee arthroplasty (TKA) generates significant gap imbalances, but little is known about whether this applies to the knees of Asian patients. The aim of this study was to evaluate the medio-lateral and flexion-extension gap imbalances and to find the most optimal posterior femoral condyle resection method for operating on the knees of Asian patients. Methods: In total, 738 magnetic resonance imaging (MRI) scans of consecutive patients who underwent TKA were obtained. Four posterior femoral condylar resection methods were used: alignment by the surgical transepicondylar axis (TEA), Whiteside’s line (WSL), 3° external rotation to the posterior condylar axis (PCA), and flexion-extension axis (FEA). Results: For the medial compartments, there were significant differences between the flexion and extension gaps in the varus knee group in all four methods, but there were no differences between the flexion and extension gaps in the valgus knee group. For the lateral compartment, all the methods showed significant differences except for WSL of the valgus knee group and FEA of the varus knee group. Conclusions: In Asian patients, the use of the MA MR technique inevitably leads to medio-lateral or flexion-extension imbalances. Therefore, surgeons should consider which methods can minimize imbalances and choose the best method within the technically possible range.

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.

Clinical and Radiological Outcomes of Meniscal Repair Versus Partial Meniscectomy for Medial Meniscus Root Tears: A Systematic Review and Meta-analysis

Background:

Given the superiority of meniscal repair over partial meniscectomy according to biomechanical data, the clinical outcomes of meniscal repair are likely to be better than those of partial meniscectomy for a medial meniscus root tear (MMRT).

Purpose/Hypothesis:

This review was designed to compare the clinical and radiological results between meniscal repair and partial meniscectomy for MMRTs. It was hypothesized that meniscal repair would result in better clinical and radiological results compared with partial meniscectomy.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

Studies were included in the review if they (1) included patients with MMRTs who underwent primary arthroscopic meniscal repair or partial meniscectomy and (2) analyzed validated patient-reported outcomes and/or radiological evaluations. Summary odds ratios (ORs) with 95% CIs were calculated to compare partial meniscectomy with meniscal repair for each outcome.

Results:

A total of 13 studies were included. The mean duration of follow-up was 33.5 and 47.2 months in the meniscal repair group and partial meniscectomy group, respectively. The change in the Lysholm score from preoperatively to postoperatively was statistically significantly in favor of meniscal repair (OR, 2.20 [95% CI, 1.55-3.12]), while no difference was found with respect to the change in the Tegner score between the 2 surgical approaches (OR, 1.21 [95% CI, 0.65-2.24]). The prevalence of postoperative severe knee osteoarthritis (OR, 0.31 [95% CI, 0.17-0.54]) as well as that of reoperations (OR, 0.05 [95% CI, 0.01-0.19]) were significantly in favor of meniscal repair.

Conclusion

Better outcomes were seen after meniscal repair compared with partial meniscectomy for MMRTs, with greater improvements in Lysholm scores, and lower rates of progression to knee osteoarthritis, and lower reoperation rate.

Effect of the presence of the articular cartilage on the femoral component rotation in total knee arthroplasty in female and varus osteoarthritis knees

Purpose

Surgical techniques for total knee arthroplasty (TKA) require femoral rotational corrections that alter the position of the surface of the posterior femoral joint especially in kinematic alignment. However, preoperative planning of TKA based on computed tomography (CT), without knowing the femoral cartilage thickness, may cause post-surgery failures in femoral rotation. Therefore, this study aimed to evaluate the effects of posterior condyle cartilage thickness on rotational alignment in the femoral component.

Methods

Three-dimensional magnetic resonance imaging (MRI) scans were obtained for 139 male and 531 female osteoarthritis patients. The angles defined by the femoral posterior condylar axis (PCA) and the surgical transepicondylar axis (TEA) were evaluated with respect to the presence of cartilage. Additionally, these effects were evaluated with respect to patient gender and varus/valgus condition.

Results

In all patients, the angle between the TEA and PCA was significantly greater in the presence of cartilage than in the absence of cartilage. This result was also seen in female patients. However, there was no difference in the TEA/PCA angle in male patients based on the presence of cartilage. The TEA/PCA angle was significantly greater in the presence of cartilage than in the absence of cartilage in the female varus group. However, there were no differences in the TEA/PCA angle based on the presence of cartilage in the male varus/valgus and female valgus groups. Cartilage thickness in the posterior femoral condyle was significantly greater on the lateral side than on the medial side in all and male patients. However, there was no difference between the genders regarding cartilage thickness.

Conclusion

Surgical planning for TKA based on CT does not consider articular cartilage and could lead to external malrotation of the femoral implant. Therefore, the effect of the remaining posterior condylar cartilage should be considered by surgeons to prevent over-rotation of the femoral component, especially in female varus knees.

Simple Medial Meniscus Posterior Horn Root Repair Using an All-Inside Meniscal Repair Device Combined with High Tibial Osteotomy to Maintain Joint-Space Width in a Patient with a Repairable Tear

PURPOSE

To compare the radiological and clinical outcomes using simple medial meniscus posterior horn (MMPH) root repair using an all-inside meniscal repair device combined with high tibial osteotomy (HTO) and HTO alone.

METHODS

Between November 2013 and December 2016, patients treated for MMPH root tear along with HTO were enrolled. Based on the tear gap, the participants were divided into repairable (< 2 mm) and unrepairable (> 2 mm) categories. The participants in each group were divided into those amenable to simple MMPH root repair using an all-inside meniscal repair device and those that required no procedure for meniscus. Radiological parameters including mechanical femorotibial alignment (MA), posterior tibial slope (PTS) and medial joint-space width (JSW) were evaluated preoperatively and postoperatively at 2 years. For clinical evaluation, the WOMAC score was determined at the 2-year visit postoperatively.

RESULTS

A total of 81 knees including 48 repairable (group R) and 33 unrepairable (group I) knees were enrolled. A total of 43 knees underwent simple MMPH root repair using an all-inside meniscal repair device (subgroup r), whereas the other 38 knees did not (subgroup n). The MA, PTS, and their postoperative changes as well as the WOMAC scores showed no differences. However, the JSW in group Rr increased from 3.1 to 3.6 mm, but decreased from 3.7 to 3.4 in group Rn, which was a statistically significant difference.

CONCLUSION

Simple MMPH root repair using an all-inside meniscal repair device combined with HTO was more effective for the maintenance of JSW compared with HTO without a meniscal procedure in patients with repairable MMPH root tear and varus alignment. However, other options are needed for unrepairable MMPH root tear.

Posterior Meniscal Root Repair Using a Meniscal Suture Device

A greater understanding of the deleterious consequences that a meniscal root tear brings to the knee joint and how its surgical repair can be advantageous over the previously used treatment strategies brings the need for the development of surgical techniques that make the procedure less complex and more reproducible. When meniscal root rupture occurs, a mechanical overload occurs in the affected compartment similar to a total meniscectomy. Several authors have concluded that meniscal root reinsertion significantly improves postoperative outcomes and patient satisfaction, regardless of age or laterality of the meniscal injury. The Meniscus 4 A-II device (Rio de Janeiro, Brazil) allows stitching at the root of the medial and lateral menisci. In this article, we describe the surgical repair technique for posterior-medial and -lateral meniscal root tears using this meniscal suture device. This technique is fast and effective.

Suture configuration techniques have no effect on mid-term clinical outcomes of arthroscopic meniscus root repairs

BACKGROUND

The aim of this study was to evaluate the clinical and radiological outcomes of arthroscopic transtibial pullout repair (ATPR) for the medial meniscus with both two modified loop stitches (TLS) and two simple stitches (TSS) techniques.

METHODS

Between January 2013 and January 2016, 41 patients who had undergone ATPR for medial root tears with TLS and TSS techniques were retrospectively evaluated. The mean age at operation was 53 years (range 45-58). The mean follow-up period was 44.6 months (range 26-64). Lysholm knee score was used for clinical evaluation before and after surgery. For all patients, meniscal extrusion distances in the coronal plane were measured using magnetic resonance imaging and were recorded both preoperatively and at final follow-up.

RESULTS

There was no difference in terms of meniscus extrusion measurements between groups preoperatively (P > .05). Postoperative meniscus extrusion measurements were 2.1 ± 0.3 and 2.9 ± 0.6 in TLS and TSS groups, respectively. The difference between groups was statistically significant (P < .01). The increase in postoperative Lysholm score was found to be statistically significant in both groups (P < .01). Postoperative Lysholm scores were 88.8 ± 3.7 and 87.6 ± 4.8 in TLS and TSS groups, respectively. The difference between groups was statistically insignificant (P > .05).

CONCLUSIONS

There was a significant improvement in Lysholm knee scores postoperatively in patients that underwent transtibial pullout medial meniscus posterior root repair regardless of meniscus reduction level and suture configuration types. Although TLS technique was superior to TSS technique in terms of meniscus reduction, this meniscus reduction did not create any clinical difference at clinical outcome.

Treatment Outcomes of Meniscal Root Tears: A Systematic Review

Purpose

To report changes in outcomes for these 3 treatment options for meniscal root tears.

Methods

We systematically searched databases including PubMed, SCOPUS, and ScienceDirect for relevant articles. Criteria from the National Heart, Lung, and Blood Institute was used for a quality assessment of the included studies. A meta-analysis was performed to analyze changes in outcomes for meniscal repair.

Results

Nineteen studies, 12 level III and 7 level IV, were included in this systematic review, with a total of 1086 patients. Conversion to total knee arthroplasty (TKA) following partial meniscectomy ranged from 11% to 54%, 31% to 35% for nonoperative, conservative treatment, and 0% to 1% for meniscal repair. Studies comparing repair with either meniscectomy or conservative treatment found greater improvement and slower progression of Kellgren–Lawrence grade with meniscal repair. A meta-analysis of the studies included in the systematic review using forest plots showed repair to have the greatest mean difference for functional outcomes (International Knee Documentation Committee and Lysholm Activity Scale) and the lowest change in follow-up joint space.

Conclusions

In patients who experience meniscal root tears, meniscal repair may provide the greatest improvement in function and lowest risk of conversion to TKA when compared with partial meniscectomy or conservative methods. Partial meniscectomy appears to provide no benefit over conservative treatment, placing patients at a high risk of requiring TKA in the near future. However, future high-quality studies—both comparative studies and randomized trials—are needed to draw further conclusions and better impact treatment decision-making.

Level of Evidence

Level IV, systematic review of level III and level IV evidence

AANA20: The 2020 Annual Meeting of the Arthroscopy Association of North America

Arthroscopy, Arthroscopy Techniques, and Arthroscopy, Sports Medicine, and Rehabilitation will be in attendance in force at the 2020 Annual Meeting of the Arthroscopy Association of North America (AANA20). Program highlights and innovations include surgery simulcasts, "Great Debates," award-winning papers, Feature Lectures, and sessions glimpsing what is On the Horizon-and perhaps over and beyond.

Effect of medial meniscus extrusion on arthroscopic surgery outcome in the osteoarthritic knee associated with medial meniscus tear: a minimum 4-year follow-up

Background:

The potential benefit of arthroscopic surgery for osteoarthritic knee associated with medial meniscus tear is controversial. This study was conducted to determine the effect of pre-operative medial meniscus extrusion (MME) on arthroscopic surgery outcomes in the osteoarthritic knee associated with medial meniscus tear during a minimum 4-year follow-up.

Methods:

This was a retrospective review of a total of 131 patients diagnosed with osteoarthritic knee associated with medial symptomatic degenerative meniscus tear who underwent arthroscopic surgery from January 2012 to December 2014 and were observed for more than 4 years. Patients were classified into two groups: MME ≥3 mm (major MME group, n = 54) and MME <3 mm (non-major MME group, n = 77). Clinical assessments, including the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and radiographic assessments, including the Kellgren-Lawrence (K-L) grade and medial joint space width (JSW), were evaluated pre-operatively and at final follow-up. The longitudinal changes of clinical and radiographic parameters (WOMAC and the medial JSW change, K-L grade progression) were compared between groups unadjusted and adjusted for age, sex, and body mass index. Four-year survival rates (without progression to knee replacement [KR]) were also evaluated using a log-rank test and Cox proportional hazard regression model.

Results:

Major MME was present in 41% of patients. After a minimum 4-year follow-up, the mean WOMAC total and pain scores improved significantly in both groups. However, the medial JSW and K-L grade worsened significantly. Patients with pre-operative major MME worsened more in WOMAC total (adjusted mean difference [MD] 3.800, 95% confidence interval [CI]: 0.900, 11.400; P = 0.037) and function (adjusted MD 3.100, 95% CI: 0.700, 6.300; P = 0.038) scores than patients with pre-operative non-major MME, and no significant difference was observed in WOMAC pain and stiffness score between groups. The group with major MME had significantly higher joint space narrowing (adjusted MD −0.630, 95% CI: −1.250, −0.100; P = 0.021) and K-L rate progression (adjusted mean relative risk [RR] 1.310, 95% CI: 1.100, 1.600; P = 0.038) than the group with non-major MME. There was a significantly more KR progression in patients with major MME compared with those with non-major MME (adjusted RR 3.100, 95% CI: 1.100, 9.200; P = 0.042 and adjusted hazard ratio 3.500, 95% CI 1.100, 9.500; P = 0.022).

Conclusions:

Osteoarthritic knee patients associated with medial meniscus tear with non-major MME are more responsive to arthroscopic surgery in terms of the clinical and radiologic outcomes and survival for at least 4-year follow-up; however, in terms of pain relief, arthroscopic surgery in patients with major MME is also beneficial as well as in patients with non-major MME.

Treatment options for the symptomatic post-meniscectomy knee

PURPOSE

To provide a current review on the evidence for management of the symptomatic meniscus-deficient knee.

METHODS

A literature review was performed detailing the natural history and origin of symptoms in a meniscus-deficient knee, in addition to strategies for non-surgical management, meniscus scaffolds, meniscus allograft transplantation (MAT), isolated cartilage repair, unloading osteotomies, meniscus prosthesis, and joint replacements which were revealed as treatment possibilities.

RESULTS

Meniscus deficiency was recognized to lead to an early onset knee osteoarthritis (OA). A subset of patients develop post-meniscectomy syndrome: dull and nagging pain after a short pain-free interval subsequently to meniscectomy, which can be accompanied by transient effusions. Evidence for non-surgical management of post-meniscectomy knee pain is lacking. Two available meniscus scaffolds, indicated for symptomatic segmental meniscus deficiency, show pain relief at mid-term follow-up, and effect on joint preservation is unclear. MAT represents a durable solution for sub/total meniscus deficiency (80% survival at 10 years), but it is still considered a temporary solution for post-meniscectomy pain. MAT may also reduce the progression of OA. Isolated cartilage repair without a meniscus reconstruction is commonly performed, but better results were reported with preserved or reconstructed menisci. Osteotomies are used in the combination of misaligned knee and meniscus reconstruction or as pain solution for irreversible unilateral knee structural changes following a meniscectomy. Polycarbonate-urethane medial meniscus prosthesis is currently undergoing clinical trial. Joint replacements should be limited to later stages of post-meniscectomy OA.

CONCLUSIONS

Post-meniscectomy pain syndrome and post-meniscectomy knee OA are common findings after meniscus resection. Short-term pain relief is provided by non-surgical management, mid-term pain relief by meniscus scaffolds, and long-term relief by MAT, though each has differing indications. In later stages, osteotomies and joint replacements are indicated.

LEVEL OF EVIDENCE

IV.

A Novel Arthroscopic Classification of Degenerative Medial Meniscus Posterior Root Tears Based on the Tear Gap

Background:

Degenerative medial meniscus posterior root tears (MMPRTs) are reportedly associated with medial compartment osteoarthritis and meniscal extrusion with a displaced gap from the root insertion. However, degenerative MMPRTs have not yet been clearly classified according to arthroscopic findings.

Purpose:

To classify degenerative MMPRTs according to the tear gap and to investigate how the classification could reflect the joint condition properly.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Patients who underwent arthroscopic surgery, performed by a single orthopaedic surgeon, for degenerative MMPRTs between August 2006 and February 2017 were included. MMPRTs were classified according to tear patterns observed during arthroscopic surgery (type 1, incomplete root tear; types 2-5, complete root tears), with each type further divided by the size of the tear gap, defined as the degree of tear displacement from the root (type 2, no gap or overlapped; type 3, gap of 1-3 mm; type 4, gap of 4-6 mm; type 5, gap of ≥7 mm). We compared preoperative factors, including the Kellgren-Lawrence (K-L) grade, absolute extrusion, relative percentage of extrusion (RPE), tear gap on magnetic resonance imaging (MRI), and mechanical alignment, as well as intraoperative factors, including chondral wear at surgery, between each MMPRT type.

Results:

A total of 116 root tears were categorized according to this classification: type 1, 16.4% (19 knees); type 2, 9.5% (11 knees); type 3, 40.5% (47 knees); type 4, 25.0% (29 knees); and type 5, 8.6% (10 knees). Chondral wear of the medial femoral condyle (MFC) (P = .001), K-L grade (P = .001), meniscal extrusion (P = .001), and tear gap on MRI (P = .001) showed a tendency to increase with a higher tear type. Chondral wear (ρ for MFC = 0.388; ρ for MTP = 0.311), K-L grade (ρ = 0.390), and meniscal extrusion (ρ for absolute extrusion = 0.500; ρ for RPE = 0.451) showed a moderate correlation with tear type, whereas tear gap on MRI (ρ = 0.907) showed a strong correlation with tear type.

Conclusion:

Our study introduces a new classification based on the tear gap that can concisely describe a degenerative MMPRT. The classification system demonstrated that a higher tear type (increasing displacement of the tear gap in arthroscopic surgery) is associated with higher meniscal extrusion, severe chondral wear, and greater severity of arthritis.

Meniscus Root Repair vs Meniscectomy or Nonoperative Management to Prevent Knee Osteoarthritis After Medial Meniscus Root Tears: Clinical and Economic Effectiveness

BACKGROUND

Medial meniscus root tears are a common knee injury and can lead to accelerated osteoarthritis, which might ultimately result in a total knee replacement.

PURPOSE

To compare meniscus repair, meniscectomy, and nonoperative treatment approaches among middle-aged patients in terms of osteoarthritis development, total knee replacement rates (clinical effectiveness), and cost-effectiveness.

STUDY DESIGN

Meta-analysis and cost-effectiveness analysis.

METHODS

A systematic literature search was conducted. Progression to osteoarthritis was pooled and meta-analyzed. A Markov model projected strategy-specific costs and disutilities in a cohort of 55-year-old patients presenting with a meniscus root tear without osteoarthritis at baseline. Failure rates of repair and meniscectomy procedures and disutilities associated with osteoarthritis, total knee replacement, and revision total knee replacement were accounted for. Utilities, costs, and event rates were based on literature and public databases. Analyses considered a time frame between 5 years and lifetime and explored the effects of parameter uncertainty.

RESULTS

Over 10 years, meniscus repair, meniscectomy, and nonoperative treatment led to 53.0%, 99.3%, and 95.1% rates of osteoarthritis and 33.5%, 51.5%, and 45.5% rates of total knee replacement, respectively. Meta-analysis confirmed lower osteoarthritis and total knee replacement rates for meniscus repair versus meniscectomy and nonoperative treatment. Discounted 10-year costs were $22,590 for meniscus repair, as opposed to $31,528 and $25,006 for meniscectomy and nonoperative treatment, respectively; projected quality-adjusted life years were 6.892, 6.533, and 6.693, respectively, yielding meniscus repair to be an economically dominant strategy. Repair was either cost-effective or dominant when compared with meniscectomy and nonoperative treatment across a broad range of assumptions starting from 5 years after surgery.

CONCLUSION

Repair of medial meniscus root tears, as compared with total meniscectomy and nonsurgical treatment, leads to less osteoarthritis and is a cost-saving intervention. While small confirmatory randomized clinical head-to-head trials are warranted, the presented evidence seems to point relatively clearly toward adopting meniscus repair as the preferred initial intervention for medial meniscus root tears.

Pullout fixation for medial meniscus posterior root tears: clinical results were not age-dependent, but osteoarthritis progressed

PURPOSE

This study investigated the outcomes of pullout fixation for medial meniscus posterior root tears (MMPRTs) in patients ≤ 60 years old versus patients > 60 years old. It was hypothesized that older patients would demonstrate results comparable with those of younger patients.

METHODS

Patients with pullout fixation who were followed-up for more than 5 years were included. Patients were categorized into two groups based on age (group A, ≤ 60 years; group B, > 60 years). The Lysholm score, Kellgren-Lawrence (K-L, 0/1/2/3/4) grade, and medial joint space width were evaluated retrospectively. Preoperative results were compared with the final results in each group, which were compared between groups.

RESULTS

Twenty-five patients in group A (mean age, 54.7 ± 3.8 years) and 22 patients in group B (mean age, 65.6 ± 4.4 years) were recruited. The mean follow-up duration was 70.9 months. The Lysholm score (group A, 53.0 ± 9.1 to 86.0 ± 12.1, P < 0.001; group B, 51.1 ± 7.1 to 82.9 ± 9.7, P < 0.001) improved significantly. However, the joint space width (group A, 4.7 ± 1.1 to 3.9 ± 1.1 mm, P < 0.001; group B, 4.7 ± 0.9 to 3.8 ± 0.9 mm, P < 0.001) and K-L grade (group A, 3/17/5/0/0 to 0/7/11/7/0, P < 0.001; group B, 2/14/6/0/0 to 0/3/14/5/0, P < 0.001) worsened significantly. No significant differences between groups were observed in final outcomes, including Lysholm score (n.s.), K-L grade (n.s.), and joint space narrowing (n.s.). No case with operation failure that require total knee arthroplasty was not observed.

CONCLUSION

MMPRT fixation did not prevent the progression of arthrosis completely. However, clinical outcomes were not age-dependent. Thus, age may not be a critical factor to consider when applying fixation.

LEVEL OF EVIDENCE

Retrospective case-control study; Level of evidence, IV.

Arthroscopic repair of the meniscus: Surgical management and clinical outcomes

From the biomechanical and biological points of view, an arthroscopic meniscal repair (AMR) should always be considered as an option. However, AMR has a higher reoperation rate compared with arthroscopic partial meniscectomy, so it should be carefully indicated.

Compared with meniscectomy, AMR outcomes are better and the incidence of osteoarthritis is lower when it is well indicated.

Factors influencing healing and satisfactory results must be carefully evaluated before indicating an AMR.

Tears in the peripheral third are more likely to heal than those in the inner thirds.

Vertical peripheral longitudinal tears are the best scenario in terms of success when facing an AMR.

‘Inside-out’ techniques were considered as the gold standard for large repairs on mid-body and posterior parts of the meniscus. However, recent studies do not demonstrate differences regarding failure rate, functional outcomes and complications, when compared with the ‘all-inside’ techniques.

Some biological therapies try to enhance meniscal repair success but their efficacy needs further research. These are: mechanical stimulation, supplemental bone marrow stimulation, platelet rich plasma, stem cell therapy, and scaffolds and membranes.

Meniscal root tear/avulsion dramatically compromises meniscal stability, accelerating cartilage degeneration. Several options for reattachment have been proposed, but no differences between them have been established. However, repair of these lesions is actually the reference of the treatment.

Meniscal ramp lesions consist of disruption of the peripheral attachment of the meniscus. In contrast, with meniscal root tears, the treatment of reference has not yet been well established.

Cite this article: EFORT Open Rev 2018;3:584-594. DOI: 10.1302/2058-5241.3.170059

Arthroscopic scoring system of meniscal healing following medial meniscus posterior root repair

PURPOSE

Medial meniscus posterior root tear (MMPRT) leads to a rapid degradation of articular cartilage. In the treatment of MMPRT, transtibial pullout repair demonstrates a high clinical survival rate. However, there is no reliable method to evaluate the meniscal healing after surgery. We propose an arthroscopic scoring system for evaluating the meniscal healing status. The aim of this study was to investigate the correlations between second-look arthroscopic scores and clinical outcomes after transtibial pullout repair.

METHODS

Twenty patients who had MMPRTs underwent transtibial pullout repairs. Clinical outcomes were assessed using the Japanese Knee Injury and Osteoarthritis Outcome Score (KOOS) and pain score evaluated by visual analogue scale at preoperatively and 1 year postoperatively. The healing status of repaired MM was assessed at one year post-operatively using a semi-quantitative arthroscopic scoring system (total, 10 points) composed of three evaluation criteria: (i) anteroposterior width of bridging tissues, (ii) stability of the MM posterior root, and (iii) synovial coverage of the sutures. Linear regression analysis was used to assess the correlation between second-look arthroscopic scores and clinical outcomes.

RESULTS

Transtibial pullout repairs of MMPRTs significantly improved clinical evaluation scores at one year post-operatively. A median of second-look arthroscopic scores was 6.5 (5.75-8). A good correlation was observed between the arthroscopic score and KOOS quality of life (QOL) subscale. A moderate negative correlation between the arthroscopic score and pain score was observed.

CONCLUSIONS

This study demonstrated that our semi-quantitative scoring system of meniscal healing correlated with the KOOS QOL subscale following MMPRT transtibial pullout repair. Our results suggest that the second-look arthroscopic score using this system may be a useful scale to determine and compare the healing status of the MM posterior root.

Modern treatment of meniscal tears

The complex ultrastructure of the meniscus determines its vital functions for the knee, the lower extremity, and the body.

The most recent concise, reliable, and valid classification system for meniscal tears is the International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine (ISAKOS) Classification, which takes into account the subsequent parameters: tear depth, tear pattern, tear length, tear location/rim width, radial location, location according to the popliteal hiatus, and quality of the meniscal tissue.

It is the orthopaedic surgeon’s responsibility to combine clinical information, radiological images, and clinical experience in an effort to individualize management of meniscal tears, taking into account factors related to the patient and lesion.

Surgeons should strive not to operate in most cases, but to protect, repair or reconstruct, in order to prevent early development of osteoarthritis by restoring the native structure, function, and biomechanics of the meniscus.

Currently, there are three main methods of modern surgical management of meniscus tears: arthroscopic partial meniscectomy; meniscal repair with or without augmentation techniques; and meniscal reconstruction. Meniscus surgery has come a long way from the old slogan, “If it is torn, take it out!” to the currently accepted slogan, “Save the meniscus!” which has guided evolving modern treatment methods for meniscal tears. This last slogan will probably constitute the basis for newer alternative biological treatment methods in the future.

Cite this article: EFORT Open Rev 2018;3 DOI: 10.1302/2058-5241.3.170067.

Editorial Commentary: We Know We Need to Fix Knee Meniscal Radial Root Tears-But How Best to Perform the Repairs?

The present work further contributes to building the base of the research pyramid by noting the importance of repairing knee meniscal radial root tears. Because of the extensive biomechanical studies that have now been published on the restoration of joint mechanics and with what I believe results in a higher likelihood of an improved healing environment with securing the meniscus root tear down to bone, I would strongly recommend that when one does see a meniscus root tear that the transtibial pullout root repair technique be considered over a side-to-side repair. The biggest challenge going forward is to validate and improve the healing potential of knee meniscal radial root repairs.

Editorial Commentary: Knee Medial Meniscus Root Tears: "You May Not Have Seen It, But It's Seen You"

Medial meniscus root tears are becoming increasingly recognized in clinical practice as a source of profound pain and dysfunction in patients. There has been considerable debate about the cause of these distinct meniscus tears, and what the optimal treatment should be for an individual patient. Midterm medial meniscus root repair results suggest that in a well-aligned knee with minimal degenerative change, transtibial root repair is an effective technique for improving pain, function, and possibly preventing further cartilage degeneration.