Partial Meniscectomy for Degenerative Medial Meniscal Root Tears Shows Favorable Outcomes in Well-Aligned, Nonarthritic Knees

Long-term clinical and radiological outcomes after arthroscopic partial meniscectomy on stable knees are better for traumatic tears when compared to degenerative lesions: A systematic review

PURPOSE

An arthroscopic partial meniscectomy (APM) for degenerative meniscus lesions and traumatic meniscus tears are two distinct entities and their long-term outcomes are rarely reported. The aim of this review was to compare the long-term (clinical and radiological) results of APM performed on stable knees for traumatic tears (TT) or degenerative lesions (DL).

METHODS

Pubmed, Scopus and Embase databases were searched to identify relevant studies published between 2010 and 2023 using the keywords 'meniscectomy' OR 'meniscectomies' OR 'meniscal resection'. English-language, Levels I-IV evidence studies reporting either radiographic or clinical outcome measures with a minimum of 6 years' follow-up after APM were included. Studies including discoid meniscus, open meniscectomy, unstable knee and combination with other procedures were excluded. To rate the quality of evidence, the methodological index for non-randomized studies was used.

RESULTS

Thirty-two studies were included, with follow-up periods ranging from 6 to 22 years. Eleven studies dealt with TT with a mean age of 31.5 ± 6.6 years and a mean follow-up of 11.6 ± 6.9 years. At the last follow-up, radiographic osteoarthritis (OA) ranged from 36% to 76%, with an average rate of 48 ± 19%; functional scores ranged from 71 to 97, with a mean of 90 ± 4 for the Lysholm score, 86 ± 10 for the International Knee Documentation Committee (IKDC) and 94 ± 16 for the knee injury and osteoarthritis outcome (KOOS). Twenty-one studies dealt with DL with a mean age of 49.9 ± 7.2 years and a mean follow-up of 14.9 ± 6.3 years. At the last follow-up, radiographic OA ranged from 23% to 97%, with an average rate of 77 ± 28%; functional scores ranged from 40 to 87, with a mean of 79 ± 10 for the Lysholm score and 71 ± 16 for the IKDC.

CONCLUSION

Ten-year clinical outcomes of APM are better for TTs when compared to DLs. Rates of OA are difficult to compare but lower for TTs.

LEVEL OF EVIDENCE

Level IV.

Reconstruction of medial meniscus posterior portion deficiency in pigs with an autologous patellar tendon graft: an experimental study

OBJECTIVE

This study was performed to investigate the effectiveness of two surgical procedures, autologous patellar tendon graft reconstruction and trans-tibial plateau pull-out repair, using a pig model. The primary focus was to assess the repair capability of medial meniscus posterior portion (MMPP) deficiency, the overall structural integrity of the meniscus, and protection of the femoral and tibial cartilage between the two surgical groups. The overall aim was to provide experimental guidelines for clinical research using these findings.

METHODS

Twelve pigs were selected to establish a model of injury to the MMPP 10 mm from the insertion point of the tibial plateau. They were randomly divided into three groups of four animals each: reconstruction (autologous tendon graft reconstruction of the MMPP), pull-out repair (suture repair of the MMPP via a trans-tibial plateau bone tunnel), and control (use of a normal medial meniscus as the negative control). The animals were euthanized 12 weeks postoperatively for evaluation of the meniscus, assessment of tendon bone healing, and gross observation of knee joint cartilage. The tibial and femoral cartilage injuries were evaluated using the International Society for Cartilage Repair (ICRS) grade and Mankin score. Histological and immunohistochemical staining was conducted on the meniscus-tendon junction area, primary meniscus, and tendons. The Ishida score was used to evaluate the regenerated meniscus in the reconstruction group. Magnetic resonance imaging (MRI) was used to evaluate meniscal healing.

RESULTS

All 12 pigs recovered well after surgery; all incisions healed without infection, and no obvious complications occurred. Gross observation revealed superior results in the reconstruction and pull-out repair groups compared with the control group. In the tibial cartilage, the reconstruction group had ICRS grade I injury whereas the pull-out repair and control groups had ICRS grade II and III injury, respectively. The Mankin score was significantly different between the reconstruction and control groups; histological staining showed that the structure of the regenerated meniscus in the reconstruction group was similar to that of the original meniscus. Immunohistochemical staining showed that the degree of type I and II collagen staining was similar between the regenerated meniscus and the original meniscus in the reconstruction group. The Ishida score was not significantly different between the regenerated meniscus and the normal primary meniscus in the reconstruction group. MRI showed that the MMPP in the reconstruction and pull-out repair groups had fully healed, whereas that in the control group had not healed.

CONCLUSION

Autologous patellar tendon graft reconstruction of the MMPP can generate a fibrocartilage-like regenerative meniscus. Both reconstruction and pull-out repair can preserve the structural integrity of the meniscus, promote healing of the MMPP, delay meniscal degeneration, and protect the knee cartilage.

Current advances in engineering meniscal tissues: insights into 3D printing, injectable hydrogels and physical stimulation based strategies

The knee meniscus is the cushioning fibro-cartilage tissue present in between the femoral condyles and tibial plateau of the knee joint. It is largely avascular in nature and suffers from a wide range of tears and injuries caused by accidents, trauma, active lifestyle of the populace and old age of individuals. Healing of the meniscus is especially difficult due to its avascularity and hence requires invasive arthroscopic approaches such as surgical resection, suturing or implantation. Though various tissue engineering approaches are proposed for the treatment of meniscus tears, three-dimensional (3D) printing/bioprinting, injectable hydrogels and physical stimulation involving modalities are gaining forefront in the past decade. A plethora of new printing approaches such as direct light photopolymerization and volumetric printing, injectable biomaterials loaded with growth factors and physical stimulation such as low-intensity ultrasound approaches are being added to the treatment portfolio along with the contemporary tear mitigation measures. This review discusses on the necessary design considerations, approaches for 3D modeling and design practices for meniscal tear treatments within the scope of tissue engineering and regeneration. Also, the suitable materials, cell sources, growth factors, fixation and lubrication strategies, mechanical stimulation approaches, 3D printing strategies and injectable hydrogels for meniscal tear management have been elaborated. We have also summarized potential technologies and the potential framework that could be the herald of the future of meniscus tissue engineering and repair approaches.

Root Repair Has Superior Radiological and Clinical Outcomes Than Partial Meniscectomy and Nonoperative Treatment in the Management of Meniscus Root Tears: A Systematic Review

PURPOSE

To compile and analyze structural and clinical outcomes after meniscus root tear treatment as currently described in the literature.

METHODS

A review was conducted to identify studies published since 2011 on efficacy of repair, meniscectomy, and nonoperative management in the treatment of meniscus root tears. Patient cohorts were grouped into treatment categories, with medial and lateral root tears analyzed separately; data were collected on patient demographics, structural outcomes including joint space width, degree of medial meniscal extrusion, progression to total knee arthroplasty, and patient-reported outcome measures. Risk of bias was assessed using the MINORS (methodological index for non-randomized studies) criteria. Heterogeneity was measured using the I-statistic, and outcomes were summarized using forest plots without pooled means.

RESULTS

The 56 included studies comprised a total of 3,191 patients. Mean age among the included studies ranged from 24.6 to 65.6 years, whereas mean follow-up ranged from 12 to 125.9 months. Heterogeneity analysis identified significant differences between studies. Change in joint space width ranged from -2.4 to -0.6 mm (i.e., decreased space) after meniscectomy (n = 186) and -0.9 to -0.1 mm after root repair (n = 209); change in medial meniscal extrusion ranged from -0.6 to 6.5 mm after root repair (n = 521) and 0.2 to 4.2 mm after meniscectomy (n = 66); and event rate for total knee arthroplasty ranged from 0.00 to 0.22 after root repair (n = 205), 0.35 to 0.60 after meniscectomy (n = 53), and 0.27 to 0.35 after nonoperative treatment (n = 93). Root repair produced the greatest numerical increase in International Knee Documentation Committee and Lysholm scores of the 3 treatment arms. In addition, root repair improvements in Knee Injury and Osteoarthritis Outcome Score Pain (range: 22-32), Sports and Recreational Activities (range: 23-36), Quality of Life (range: 22-42), and Symptoms subscales (range: 10-19), in studies with low risk of bias.

CONCLUSIONS

The literature reporting on the treatment of meniscus root tears is heterogenous and largely limited to Level III and IV studies. Current evidence suggests root repair may be the most effective treatment strategy in lessening joint space narrowing of the knee and producing improvements in patient-reported outcomes.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II-IV studies.

Risk Factor for Clinical Failure of Medial Meniscal Allograft Transplant: Early vs Late Graft Tear

BACKGROUND

Graft tears are common postoperative findings in meniscal allograft transplant (MAT). Graft tear in medial MAT may be different from that of lateral MAT, considering the difference between medial meniscal tears and lateral meniscal tears. Moreover, medial MAT is frequently accompanied by ligament reconstruction, which is associated with graft tear. The effect of graft tear on the long-term survivorship of medial MAT has not been investigated.

HYPOTHESIS

Graft tear would adversely affect the survivorship of medial MAT and the effect would be different according to the timing of graft tear.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 55 patients undergoing medial MAT between June 2019 and March 2000 were retrospectively reviewed. Postoperative magnetic resonance imaging (MRI) scans were reviewed to identify graft tears, and the timing of their occurrence was investigated. Postoperative MRI was performed routinely during the first postoperative year and every 2 years thereafter. The patients were classified into a no graft tear (NT) group, early graft tear (occurring within 1 year; ET) group, and late graft tear (occurring 1 year after surgery; LT) group. The survival rate of medial MAT was estimated according to graft tear, with a failure being defined as (1) reoperations including arthroplasty, realignment osteotomy, revision MAT, and meniscectomy (>50% of the graft or to the zone of the meniscocapsular junction) or (2) Lysholm score <65. Clinical scores were compared between the groups.

RESULTS

The mean follow-up duration was 8.6 ± 5.3 years. During that period, clinical failures occurred in 6 (10.9%) patients. The overall survival rate at 5 years was 94.0% (95% CI, 90.6%-97.4%). Graft tears were seen in 18 patients: 6 patients in the ET group and 12 patients in the LT group. The median time when the graft tear was noted on MRI scans was 5.5 months (range, 1-11 months) postoperatively in the ET group and 99.5 months (range, 19-264 months) postoperatively in the LT group. Five patients in the ET group had root tears, whereas 9 patients in the LT group had complex or horizontal tears. The 5-year survival rate of the ET group was 62.5% (95% CI, 41.2%-83.8%), which was significantly lower than that of the NT group (96.8%; 95% CI, 93.6%-99.9%) and the LT group (85.7%; 95% CI, 72.5%-98.9%; P = .002). The mean postoperative Lysholm scores were 85.6 ± 17.9 in the NT group, 93.0 ± 2.8 in the ET group, and 79.3 ± 11.6 in the LT group, showing no significant difference between the groups (Kruskal-Wallis test, P = .058).

CONCLUSION

Clinical relevance of graft tear that occurred after medial MAT was dependent upon its timing. ET was a risk factor for clinical failure, whereas LT did not adversely affect graft survivorship. Lysholm scores did not differ according to graft tear.

Preoperative Predictors of Arthroscopic Partial Meniscectomy Outcomes: The APM Index Score

BACKGROUND

Preoperative risk factors contributing to poor outcomes after arthroscopic partial meniscectomy (APM) have not yet been consolidated and codified into an index scoring system used to predict APM success.

PURPOSE

To create an index score using available preoperative factors to predict the likelihood of favorable postoperative outcomes after APM.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

A consecutive cohort of patients undergoing primary APM were enrolled in this study. Patients completed pre- and postoperative patient-reported outcome measure (PROM) questionnaires that included the Knee injury and Osteoarthritis Outcome Score (KOOS), visual analog scale (VAS) for pain, Veterans RAND 12-Item Health Survey (VR-12 Physical and Mental), and Marx Activity Rating Scale (MARS). Multivariable logistic regression models were performed to evaluate independent predictors of KOOS Pain, Symptoms, and Activities of Daily Living scores and achievement of the minimal clinically important difference (MCID) and substantial clinical benefit (SCB). The authors assigned points to each variable proportional to its odds ratio, rounded to the nearest integer, to generate the index score.

RESULTS

In total, 468 patients (mean age, 49 years [SD, 10.4 years; range, 19-81 years]) were included in this study. In the univariate analysis, shorter symptom duration, lower Kellgren-Lawrence (KL) grade, lower preoperative KOOS Pain value, and lower VR-12 Physical score were associated with a higher likelihood of clinical improvement at 1 year. In the multivariable model for clinical improvement with MCID, symptom duration (<3 months: OR, 3.00 [95% CI, 1.45-6.19]; 3-6 months: OR, 2.03 [95% CI, 1.10-3.72], compared with >6 months), KL grade (grade 0: OR, 3.54 [95% CI, 1.66-7.54]; grade 1: OR, 3.04 [95% CI, 1.48-6.26]; grade 2: OR, 2.31 [95% CI, 1.02-5.27], compared with grade 3), and preoperative KOOS Pain value (score <45: OR, 3.00 [95% CI, 1.57-5.76]; score of 45-60: OR, 2.80 [95% CI, 1.47-5.35], compared with score >60) were independent significant predictors for clinical improvement. The scoring algorithm demonstrated that a higher total score predicted a higher likelihood of achieving the MCID: 0 = 40%, 1 = 68%, 2 = 80%, 3 = 89%, and 4 = 96%.

CONCLUSION

Using this model, the authors developed an index score that, using preoperative factors, can help identify which patients will achieve clinical improvement after APM. Longer symptom duration and higher KL grade were associated with a decreased likelihood of clinical improvement as measured by KOOS Pain at 1 year postoperatively.

Epidemiological features of acute medial meniscus posterior root tears

PURPOSE

Untreated or overlooked medial meniscus posterior root tears (MMPRTs) induce sequential knee joint degradation. We evaluated epidemiological features of acute MMPRT for its early detection and accurate diagnosis.

METHODS

Among 330 MMPRT patients from 2018 to 2020, those who underwent arthroscopic pullout repairs were enrolled. Patients who underwent non-operative treatment or knee arthroplasty, those with a cruciate ligament-deficient knee or advanced osteoarthritis of the knee, and those with insufficient data were excluded. Finally, we retrospectively evaluated data from 234 MMPRTs (female: 79.9%, complete tears: 92.7%, mean age: 65 years). Welch's t-test and Chi-squared test were used for pairwise comparisons. Spearman's rank correlation analysis was performed between age at surgery and body mass index (BMI). Multivariable logistic regression analysis with stepwise backward elimination was applied to the values as risk factors for painful popping events.

RESULTS

In both sexes, there were significant differences in height, weight, and BMI. In all patients, there was a significant negative correlation between BMI and age (ρ =  - 0.36, p < 0.001). The BMI cutoff value of 27.7 kg/m2 had a 79.2% sensitivity and a 76.9% specificity for detecting MMPRT patients aged < 50 years. A painful popping event was confirmed in 187 knees (79.9%), and the frequency was significantly reduced in partial tears as compared to complete tears (odds ratio: 0.080, p < 0.001).

CONCLUSION

Higher BMI was associated with a significantly younger age of MMPRT onset. Partial MMPRTs had a low frequency of painful popping events (43.8%).

Medial Meniscus Posterior Root Tear: How Far Have We Come and What Remains?

Medial meniscus posterior root tears (MMRTs), defined as tears or avulsions that occur within 1 cm of the tibial attachment of the medial meniscus posterior root, lead to biomechanically detrimental knee conditions by creating a functionally meniscal-deficient status. Given their biomechanical significance, MMRTs have recently been gaining increasing interest. Accordingly, numerous studies have been conducted on the anatomy, biomechanics, clinical features, diagnosis, and treatment of MMRTs, and extensive knowledge has been accumulated. Although a consensus has not yet been reached on several issues, such as surgical indications, surgical techniques, and rehabilitation protocols, this article aimed to comprehensively review the current knowledge on MMRTs and to introduce the author's treatment strategies.

Age alone does not affect the joint survivorship after arthroscopic partial meniscectomy for degenerative medial meniscus tears: a propensity-score matched survival analysis

PURPOSE

To evaluate the effect of age itself on the joint survivorship after arthroscopic partial meniscectomy (APM) for degenerative medial meniscus tears (DMTs).

METHODS

Patients undergoing APM for DMTs during 1999-2010 were retrospectively reviewed. The inclusion criteria were as follows: (1) DMTs identified on preoperative MRI scans, (2) no definite history of trauma, and (3) follow-up duration more than 5 years. In evaluation of the joint survivorship, the endpoint was defined as conversion to arthroplasty (or realignment osteotomy) or progression to Kellgren-Lawrence grade 4. The study population was divided into older and younger groups by a cutoff age at which the difference in the joint survival rates was maximized, using a time-dependent receiver operating characteristic (ROC) curve. The two groups were then matched based on propensity scores. The joint survival rates were compared between the groups using Kaplan-Meier analysis, before and after propensity score matching (PSM).

RESULTS

A total of 633 knees were included. The cutoff age was calculated as 60 years. Before PSM, 239 knees were allocated to the older group (≥ 60 years) and 394 knees to the younger group (< 60 years). A significant difference in the joint survival rates was noted between the groups (log-rank test, p < 0.001). After PSM, 183 knees remained in each group. The difference in the survival rates was no more statistically significant (n.s.). The latest Lysholm scores of the older and the younger groups before PSM were 72.2 ± 20.8 and 79.9 ± 19.6, respectively (p < 0.001); however, the scores after PSM were 73.2 ± 20.3 and 77.4 ± 20.5, respectively (n.s.).

CONCLUSIONS

Joint survivorship after APM was affected by other factors associated with the aging process, such as cartilage status and meniscal tear pattern, rather than age itself. Advanced age should not be the only reason for precluding APM in treatment of DMTs. APM is a viable option when treating DMTs in elderly patients if adopted with caution. According to this study, a surgeon should assess the age-related factors when he considers APM in elderly patients.

LEVEL OF EVIDENCE

III.

Comparative Efficacy of Root Repair versus Partial Meniscectomy and Observation for Patients with Meniscus Root Tears

The purpose of this study was to (1) compare the efficacy of root repair versus partial meniscectomy and observation for patients with meniscus root tears; (2) compare osteoarthritis (OA) progression and functional outcomes in patients with isolated repair and with adjuvant surgery; and (3) evaluate OA progression and functional outcomes after pullout repair or all-inside repair of meniscus root tears. We performed a systematic literature search in PubMed, Embase, Scopus, and the Cochrane Library up to September 1, 2020, to identify studies that evaluated the efficacy of root repair versus partial meniscectomy and observation in patients with meniscus root tears. Random-effects meta-analysis was used to pool data. A total of nine studies were included in the meta-analysis, with 485 patients comprising 238 in the root repair group, 113 in the partial meniscectomy group, and 134 in the observation group. The mean age of the patients ranged from 46.1 to 64.8 years. Compared with partial meniscectomy, root repair was associated with significantly lower postoperative Kellgren-Lawrence (K-L) grade (mean difference [MD]: -0.62, 95% confidence interval [CI]: -1.00 to -0.23) and progression to arthroplasty rate (odds ratio [OR]: 0.15, 95% CI: 0.04-0.60) at final follow-up. Compared with observation, root repair was associated with significantly lower arthroplasty rate (OR: 0.07, 95% CI: 0.01-0.44) and better International Knee Documentation Committee (IKDC) score (MD: 8.07, 95% CI: 0.72-15.41) at final follow-up. Moreover, significantly lower postoperative K-L grade and progression to arthroplasty rate, as well as higher IKDC and Lysholm scores were seen in favor of root repair in patients with isolated meniscus root tears. Additionally, significantly lower OA progression and higher function scores were found in favor of root repair when the tears were repaired with pullout technique. Current evidence indicates that root repair with pullout technique may be a better choice than partial meniscectomy and observation for patients with isolated meniscus root tears as measured by OA progression, progression to arthroplasty, as well as functional outcomes.

Medial meniscus posterior root tears and partial meniscectomy significantly increase stress in the knee joint during dynamic gait

PURPOSE

As a simple and invasive treatment, arthroscopic medial meniscal posterior horn resections (MMPHRs) can relieve the obstructive symptoms of medial meniscus posterior root tears (MMPRTs) but with the risk of aggravating biomechanical changes of the joint. The aim of this study was to analyze dynamic simulation of the knee joint after medial meniscus posterior root tear and posterior horn resection.

METHODS

This study established static and dynamic models of MMPRTs and MMPHRs on the basis of the intact medial meniscus model (IMM). In the finite element analysis, the three models were subjected to 1000 N axial static load and the human walking gait load defined by the ISO14243-1 standard to evaluate the influence of MMPRTs and MMPHRs on knee joint mechanics during static standing and dynamic walking.

RESULTS

In the static state, the load ratio of the medial and lateral compartments remained nearly constant (2:1), while in the dynamic state, the load ratio varied with the gait cycle. After MMPHRs, at 30% of the gait cycle, compared with the MMPRTs condition, the maximum von Mises stress of the lateral meniscus (LM) and the lateral tibial cartilage (LTC) were increased by 166.0% and 50.0%, respectively, while they changed by less than 5% during static analysis. The maximum von Mises stress of the medial meniscus (MM) decreased by 55.7%, and that of the medial femoral cartilage (MFC) increased by 53.5%.

CONCLUSION

After MMPHRs, compared with MMPRTs, there was no significant stress increase in articular cartilage in static analysis, but there was a stress increase and concentration in both medial and lateral compartments in dynamic analysis, which may aggravate joint degeneration. Therefore, in clinical treatments, restoring the natural structure of MMPRTs is first recommended, especially for physically active patients.

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.

Age and Meniscal Extrusion Are Determining Factors of Osteoarthritis Progression after Conservative Treatments for Medial Meniscus Posterior Root Tear

BACKGROUND

With a growing understanding of biomechanical disadvantages following medial meniscus posterior root tear (MMPRT), recent studies have focused on surgical repair of MMPRT. Because not all tears are repairable, surgical indications can be properly established when the outcomes of conservative treatments are revealed. This study tried to identify risk factors for osteoarthritis progression after conservative treatments for isolated MMPRT.

MATERIALS & METHODS

Patients who had conservative treatments for isolated MMPRT during 2013-2016 were retrospectively reviewed. To evaluate osteoarthritis progression, those who were followed up for ≤3 years and those who already showed advanced osteoarthritis of Kellgren--Lawrence (K-L) grade 4 at the time of diagnosis were excluded. Because patients with varus malalignment were candidates for realignment osteotomy, conservative treatments for MMPRT were applied to patients with well-aligned knees. Osteoarthritis progression was determined based on the K-L grading system, and risk factors including age, sex, body mass index, lower limb alignment, preoperative K-L grade, meniscal extrusion, and the presence of subchondral bone marrow lesion (BML) were analyzed using logistic regression analyses.

RESULTS

A total of 42 patients were followed up for 57.4 ± 26.8 months. During that period, osteoarthritis progression was noted in 17 (40.5%) patients. Based on univariate analyses for each risk factor, age, meniscal extrusion, and the presence of subchondral BML were included in the multivariate logistic regression analysis. The results showed that age (p = 0.028, odds ratio = 0.87) and meniscal extrusion (p = 0.013, odds ratio = 9.65) were significant risk factors. A receiver operating characteristic curve found that the cutoff age was 63.5 years, with the area under the curve being 0.72 (sensitivity, 68.0%; specificity, 70.6%).

CONCLUSIONS

About two-fifths of patients who had conservative treatments for MMPRT underwent osteoarthritis progression in the mid to long term. Age and meniscal extrusion were determining factors of osteoarthritis progression. The risk for osteoarthritis progression was decreased when the age of patients was over 63.5 years.

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.

Minimum 2-Year Clinical Outcomes of Medial Meniscus Root Tears in Relation to Coronal Alignment

BACKGROUND

The effect of coronal plane alignment on the outcomes of repairs of the medial meniscus root remains unclear.

HYPOTHESIS

Increased preoperative varus alignment is associated with higher failure rates and lower patient-reported outcomes (PROs) after isolated repair of the medial meniscus root.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Patients aged 18 years or older who underwent arthroscopy-assisted repair of the medial posterior meniscus root over a 7-year period were included. The mechanical axis of the knee was measured preoperatively. Osteoarthritis was assessed radiographically preoperatively and at the final follow-up according to the Kellgren-Lawrence grading scale. Failure was defined as any patient having to undergo revision root repair, partial meniscectomy of the previously repaired meniscus, debridement, lysis of adhesions, or conversion to arthroplasty.

RESULTS

A total of 53 patients (29 women, 24 men) with a mean age of 51.3 years were included in the follow-up analysis. The mean time of follow-up after surgery was 3.3 years (range, 22-77 months). Significant improvements were observed in all PROs analyzed. Decreased varus as measured by alignment percentage was correlated with baseline Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain (P = .023) and WOMAC Stiffness (P = .022). Alignment percentage was also significantly negatively correlated with postoperative WOMAC Stiffness (P = .005) and positively correlated with Lysholm (P = .003) and International Knee Documentation Committee (P = .009) scores. Higher baseline Kellgren-Lawrence grade was correlated with worse postoperative PROs (P < .05), except 12-Item Short Form Health Survey Mental Component Summary and satisfaction. Eight patients who underwent a concomitant high tibial osteotomy (HTO) achieved lower PROs in all scales analyzed, regardless of their alignment. When excluding patients who underwent HTO, postoperative Lysholm score (P = .004) and postoperative WOMAC Stiffness (p = 0.014) were inferior among the patients with >5° of varus.

CONCLUSION

Lower extremity alignment closest to neutral correlated with improved PROs. Patients who underwent a concurrent HTO had worse PROs than those who did not undergo HTO.

[Posterior meniscus root tears]

Meniscus root tears are radial tears in the region of the posterior insertion zones. Medial root injuries usually occur in individuals > 50 years of age without adequate trauma and are associated with obesity and varus deformities. The root lesion leads to a loss of ring tension, which results in extrusion of the meniscus and a strong increase in joint pressure that is biomechanically equivalent to a complete meniscectomy. When indicating arthroscopic transosseous refixation of the medial root lesion, factors such as accompanying cartilage damage, osteoarthritis, obesity and varus deformity must be taken into account. Injuries to the root of the lateral meniscus are mostly observed in younger patients in combination with a rupture of the anterior cruciate ligament. Arthroscopic transosseous refixation in combination with cruciate ligament surgery is therefore also recommended for type I and type II lesions. In summary, both the medial and the lateral root lesions of the menisci are injuries with high biomechanical relevance.

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.

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.

Medial Meniscus Posterior Root Tear Does Not Affect the Outcome of Medial Open-Wedge High Tibial Osteotomy

BACKGROUND

This study aimed to verify whether the presence of medial meniscus posterior root tear (MMPRT) affects the clinical and radiographic outcomes of medial open-wedge high tibial osteotomy (MOWHTO) compared to the patients without MMPRT for over a midterm follow-up.

METHODS

One hundred fifty-six knees were retrospectively enrolled that underwent MOWHTO and second-look arthroscopy concomitantly with a minimum 5 years of follow-up. Seventy-four knees with MMPRT (MMPRT group) were identified. Eighty-two knees with intact MMPR were assigned to another group (MMPRI group). All knees with torn medial meniscus with or without MMPRT had an arthroscopic partial meniscectomy during the MOWHTO. Clinical evaluation included range of motion, American Knee Society scores, and Western Ontario and McMaster Universities Osteoarthritis Index scores. Radiologically, the Kellgren-Lawrence grade was assessed preoperatively and at the latest follow-up. Cartilage status was also compared through the 2-stage arthroscopy according to the International Cartilage Repair Society grading.

RESULTS

Average age at operation was 55.8 years (range 42-67), and the average follow-up period was 82.2 months (range 60-148). There were no significant differences in clinical outcomes between the groups. Postoperative changes in Kellgren-Lawrence grade and arthroscopic cartilage status showed no significant differences between the groups. Resected MMPR was remodeled in 41.9% (31/74) of the MMPRT group through the second-look arthroscopy.

CONCLUSION

MMPRT does not affect the clinical and radiologic outcomes of MOWHTO compared to those patients without MMPRT over a mid-term follow-up.

Prognostic Factors of Mid- to Long-term Clinical Outcomes after Arthroscopic Partial Meniscectomy for Medial Meniscal Tears

Backgroud

Arthroscopic partial meniscectomy (APM) continues to be the popular treatment for meniscal tears, but recent randomized controlled trials have questioned its efficacy. To provide more evidence-based criteria for patient selection, we undertook this study to identify prognostic factors associated with clinical failure after APM for medial meniscus tears.

Methods

Medical records of 160 patients followed up for at least 5 years after APM for medial meniscal tears were retrospectively reviewed. Demographic data (age, sex, and body mass index), radiographic variables (Kellgren-Lawrence [K-L] grade and hip-knee-ankle [HKA] angle), and clinical scores (International Knee Documentation Committee score, Tegner activity scale score, Lysholm score, and Knee injury and Osteoarthritis Outcome Score) were recorded. Clinical failure was defined as the need for an additional surgical procedure (arthroscopy, osteotomy, or arthroplasty) or the presence of intolerable pain. Survivorship analysis with clinical failure as an end point was performed using Kaplan-Meier survival curves. Factors related to clinical failure were analyzed using a Cox proportional hazard model. Cutoff values were determined using areas under receiver operating characteristic (ROC) curves. Radiographic progression of osteoarthritis was analyzed using the chi-square test, and serial changes of clinical scores were analyzed using a linear mixed model.

Results

Clinical success rates were 95.7% at 5 years, 75.6% at 10 years, and 46.3% at 15 years. Age, HKA angle, and K-L grade (p = 0.01, p = 0.02, and p = 0.04, respectively) were found to be significant risk factors of clinical failure. Cutoff values at 10 years postoperatively as determined by ROC analysis were 50 years for age (sensitivity = 0.778, 1−specificity = 0.589), grade 2 for K-L grade (sensitivity = 0.778, 1−specificity = 0.109), and 5.5° for HKA angle (sensitivity = 0.667, 1−specificity = 0.258). In patients who had clinical success until 10 years after APM, radiological osteoarthritis progressed gradually. However, the clinical scores of patients who achieved clinical success did not decrease significantly over the 10-year follow-up.

Conclusions

The poor prognostic factors found to be related to clinical failure after APM for a medial meniscal tear were patient age (≥ 50 years), preoperative K-L grade (≥ grade 2), and preoperative HKA angle (≥ varus 5.5°).

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.

True Mechanical Alignment is Found Only on Full-Limb and not on Standard Anteroposterior Radiographs

Purpose

The purpose of this study was to compare alignment measured on standard anteroposterior (AP) radiographs versus full-length weight-bearing radiographs.

Methods

Patients were prospectively enrolled from June 2019 to August 2019 from a single orthopedic surgeon's practice if they were ≥ 18 years of age, obtained both AP and full-length alignment radiographs and were capable of full weight-bearing with appropriate positioning. Patients were excluded if they were < 18 years of age, had previous knee arthroplasty, previous knee or hip osteotomy, were unable to bear full weight on both limbs, and if the patient's body habitus precluded appropriate visualization of necessary landmarks on the radiographs. Tibiofemoral angles were measured on AP radiographs using 2 techniques (AP angles 1 and 2). Linear regression and paired t tests were used to compare measurements. The minimal clinically important difference was defined as < 2°.

Results

There were 120 patients (62 males, 58 females) with an average age of 45 ± 17 years who were enrolled. There were positive correlations between average alignment on full-length weight-bearing and AP radiographs for AP angle 1 (r = 0.72) and AP angle 2 (r = 0.76) measurement techniques (P < .001). There was a significant difference in mean alignment between full-length weight-bearing and AP measurements (AP angle 1: 2.5° difference; AP angle 2: 4.4° difference; P < .001). Frequency distributions for the minimal clinically important difference between true mechanical alignment and AP views demonstrated that 46.7% of patients had ≥ 2° difference for AP angle 1, and 78.3% of patients had ≥ 2° difference for AP angle 2.

Conclusion

The average absolute difference in alignment measured between standard AP radiograph and full-length weight-bearing radiograph views was significant, with 46.7% to 78.3% of patients having a greater than 2° absolute difference between these 2 views. In cases where precise objective alignment measurement is necessary, full-length weight-bearing radiographs are recommended over standard AP radiographs for presurgical planning so as to reduce potential error in over- or underestimation of the true mechanical alignment.

Study Design

Prospective case-comparison; Level of evidence, 1.

Progression of radiographic osteoarthritis after partial meniscectomy in degenerative medial meniscal posterior root tears was greater in varus- than in neutral-aligned knees: a minimum 5-year follow-up

PURPOSE

To perform a radiographic assessment of osteoarthritis, progression after partial meniscectomy (PM) in degenerative medial meniscus posterior root tears (MMPRTs) in relation to preoperative mechanical axis (MA). The hypothesis is that neutral-aligned knees with degenerative MMPRTs have better radiographic outcomes than those of varus-aligned knees after arthroscopic PM.

METHODS

Records of 114 patients with degenerative MMPRTs and Kellgren-Lawrence (KL) grade ≤ 2 osteoarthritis, who underwent PM, had preoperative weight-bearing hip-to-ankle radiographs from 2004 to 2014, and were followed-up for at least 5 years were reviewed retrospectively. The mean follow-up period was 8.3 ± 2.8 years. Preoperative MA values were used to classify the patients into either a Neutral (N valgus 3° to varus 3°; n = 60) or Varus-aligned group (V varus > 3°; n = 54). Joint space width (JSW; mm) and KL grade (0/1/2/3/4) were measured preoperatively and finally on weight-bearing 45° flexion posteroanterior and anteroposterior radiographs, respectively.

RESULTS

Preoperative JSW and KL grade did not differ significantly between the groups (N vs V; JSW 3.64 ± 0.83 vs 3.44 ± 0.81, P = 0.201; KL grade, 2/31/27/0/0 vs 0/22/32/0/0, P = 0.162); however, the final JSW and KL grade differed significantly between the groups (N vs V; JSW 3.03 ± 0.78 vs 2.07 ± 0.87; KL grade, 0/21/23/13/3 vs 0/10/26/21/6, both P < 0.001). The N group showed significantly less KL progression compared with the V group (N vs V; progression/no progression, 27/33 vs 42/12, P = 0.001).

CONCLUSION

The progression of radiographic osteoarthritis after PM for degenerative MMPRTs was greater in varus-aligned knees than in neutral-aligned knees. PM should be considered cautiously in patients with varus-aligned knees.

LEVEL OF EVIDENCE

Retrospective comparative study, Level III.

Degenerative medial meniscus posterior root tear and non-root tear do not show differences in joint survival and clinical outcome after partial meniscectomy

PURPOSE

No comparative studies of outcomes between degenerative medial meniscus posterior root tear (MM PRT) and non-root tear (NRT) have been conducted. This study aimed to compare joint survival and clinical outcome between MM PRT and MM NRT after partial meniscectomy with proper control of confounding factors.

METHODS

One hundred and ten patients each in MM PRT and MM NRT groups who underwent arthroscopic partial meniscectomy were retrospectively evaluated through propensity score matching. Joint survival was assessed on the basis of surgical and radiographic failures. Clinical outcomes were assessed using the Lysholm score.

RESULTS

The confounding variables were well balanced between the groups, with standardized mean differences of < 0.2 after propensity score matching. Failures occurred in 30 (27.3%) and 35 patients (31.8%) in the MM PRT group and MM NRT group, respectively. The estimated mean survival times were 12.5 years (95% confidence interval [CI] 11.5-13.5) and 11.7 years (10.7-12.7), respectively. There were no significant differences in the overall survival rate and Lysholm score between the two groups (n.s.).

CONCLUSION

In middle-aged patients with degenerative MM PRT, joint survival and clinical outcome showed comparable results with those with MM NRT after partial meniscectomy. Arthroscopic partial meniscectomy is one of the effective treatments for MM PRT with consideration of various patient factors.

LEVEL OF EVIDENCE

III.

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.

Spontaneous Osteonecrosis/Subchondral Insufficiency Fractures of the Knee: High Rates of Conversion to Surgical Treatment and Arthroplasty

BACKGROUND

Spontaneous osteonecrosis of the knee has recently been termed subchondral insufficiency fracture of the knee (SIFK) to appropriately recognize the etiology of mechanical overloading of the subchondral bone. The purpose of this study was to assess clinical outcomes of SIFK based on progression to surgical treatment and arthroplasty, and to evaluate the risk factors that increase the progression to arthroplasty.

METHODS

A retrospective review was performed on patients with a diagnosis of SIFK, as confirmed with use of magnetic resonance images (MRIs). Baseline and final radiographs were reviewed. Baseline MRIs were also reviewed for injury characteristics. Failure was defined as progression to surgical treatment or conversion to arthroplasty.

RESULTS

Two hundred twenty-three patients (71% female) with a mean age of 65.1 years were included. SIFK affected 154 femora (69%) and 123 tibiae (55%), with medial compartment involvement in 198 knees (89%); 74% of medial menisci had root or radial tears, with a mean extrusion of 3.6 mm. Varus malalignment was identified in 54 (69%) of 78 knees. Seventy-six (34%) of all patients progressed to surgical intervention at 2.7 years, and 66 (30%) underwent arthroplasty at 3.0 years. The rates of conversion to surgical intervention and arthroplasty increased to 47% (37 of 79; p = 0.04) and 37% (29 of 79; p = 0.09), respectively, in patients with >5 years of follow-up. The 10-year survival rate free of arthroplasty for patients with SIFK on the medial femoral condyle (p < 0.01), SIFK on the medial tibial plateau (p < 0.01), medial meniscal extrusion (p = 0.01), varus alignment (p = 0.02), and older age (per year older; p = 0.003) was significantly higher than the survival rates of those without each respective condition.

CONCLUSIONS

Subchondral insufficiency fractures predominantly involve the medial compartment of the knee and commonly present with medial meniscal root and radial tears. Approximately one-third of patients progressed to total knee arthroplasty. Baseline arthritis, older age, location of the insufficiency fracture on both the medial femoral condyle and medial tibial plateau, meniscal extrusion, and varus malalignment were all associated with progression to arthroplasty.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Comparison of Clinical and Semiquantitative Cartilage Grading Systems in Predicting Outcomes After Arthroscopic Partial Meniscectomy

OBJECTIVE. Cartilage loss on preoperative knee MRI is a predictor of poor outcomes after arthroscopic partial meniscectomy. The purpose of this study was to compare the ability to predict outcomes after arthroscopic partial meniscectomy with a clinically used modified Outerbridge system versus a semiquantitative MRI Osteoarthritis Knee Score system for grading cartilage loss. MATERIALS AND METHODS. Patients who underwent preoperative knee MRI within 6 months of arthroscopic partial meniscectomy and who had outcomes available from the time of surgery and 1 year later were eligible for inclusion. Cases were evaluated by two radiologists and one radiology fellow with the use of both grading systems. The accuracy of each system in discriminating between surgical success and failure was estimated using the ROC curve (AUC) with 95% CIs. A Wald test was used to assess noninferiority of the clinical grading system. Interreader agreement regarding the accuracy of the grading systems in predicting outcomes was also compared. RESULTS. A total of 78 patients (38 women and 40 men; mean age, 56.6 years) were included in the study. A prediction model using clinical grading (AUC = 0.695; 95% CI, 0.566-0.824) was noninferior (p = 0.047) to a model using MRI Osteoarthritis Knee Score grading (AUC = 0.683; 95% CI, 0.539-0.827). Both MRI prediction models performed better than a model using demographic characteristics only (AUC = 0.667; 95% CI, 0.522-0.812). Inter-reader agreement with clinical grading (80.8%) was higher than that with MRI Osteoarthritis Knee Score grading (65.0%; p = 0.012). CONCLUSION. A clinically used system to grade cartilage loss on MRI is as effective as a semiquantitative system for predicting outcomes after arthroscopic partial meniscectomy, while also offering improved interreader agreement.

Partial Medial Meniscectomy Using Needle Arthroscopy and a Standardized Local Anesthetic Protocol

Needle arthroscopic procedures of the knee offer potential advantages over standard arthroscopic procedures. The small size of the instruments allows for surgery without the use of a scalpel or suture, potentially decreased recovery times, and potentially reduced complication rates compared with traditional arthroscopy. In some patients, the procedure can be performed without the use of either general anesthesia or sedation. The purpose of this article is to provide a standardized technique guide for needle arthroscopic partial medial meniscectomy under local anesthesia.

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

Medial Versus Lateral Meniscus Root Tears: Is There a Difference in Injury Presentation, Treatment Decisions, and Surgical Repair Outcomes?

PURPOSE

To determine (1) the demographic characteristics as well as radiographic findings of medial versus lateral meniscal root tears at time of presentation, (2) treatment decisions and clinical outcomes of patients undergoing medial versus lateral root repair, and (3) risk factors for worse clinical and radiographic outcomes.

METHODS

A retrospective review was performed to identify patients with symptomatic, medial, or lateral meniscus posterior root tears with a minimum 2-year follow-up. Radiographs were graded using Kellgren-Lawrence scores. Subanalysis was performed on 62 patients who underwent root repair. Tegner, Lysholm, International Knee Documentation Committee scores, and progression to arthroplasty were analyzed in the repair groups. Patient demographics, radiographic findings, and clinical outcomes were compared between medial meniscus posterior horn root tear (MMRT) and lateral meniscus root repair (LMRT).

RESULTS

Of the 141 root tears, 109 were MMRTs, 30 were LMRTs, and 2 patients had both. At the time of injury, patients with MMRTs had a significantly higher age (MMRT = 51.4 vs LMRT=24.6, P < .0001), body mass index (MMRT = 32.1 vs LMRT 25.8, P < .0001), Kellgren-Lawrence score (MMRT = 1.3 vs LMRT=0.6, P < .0001), and higher rate of major meniscal extrusion (MMRT = 72% vs LMRT = 20%, P < .0001). Of the 30 LMRT, 30/30 (100.0%) were treated with meniscal repair. With MMRT, 52/109 (48%) were treated nonoperatively, 27/109 (25%) with partial meniscectomy, and 30/109 (27%) with meniscal repair. Sixty-two patients underwent meniscus root repair with an average 41-month follow-up. LMRT had significantly increased International Knee Documentation Committee (LMRT = 89.5, MMRT = 80.4, P = .02) and Tegner scores (LMRT = 6.5, MMRT = 5.1, P < .05) compared with MMRT.

CONCLUSIONS

Compared with MMRTs, LMRTs occur in younger male patients with lower body mass index, less cartilage degeneration, less extrusion on magnetic resonance imaging, and more commonly with a ligament injury. Although good to excellent clinical outcomes were attained in select patients for both medial and lateral meniscus root repair, LMRTs may have better results after repair, suggesting that differences in injury and patient characteristics may contribute to differences in these outcomes.

LEVEL OF EVIDENCE

Retrospective comparative study, Level III.

Editorial Commentary: Are We Over-treating Meniscal Root Tears?

Meniscal root tears function as a complete meniscectomy, with loss of hoop stress due to the detachment of the meniscus. Root tears have been increasingly recognized recently with improvements in diagnostic imaging and the understanding of meniscal biomechanics. Patients have a high rate of progression of osteoarthritis and subsequent knee replacement after a meniscal root tear. Recent advances in repair techniques, arthroscopic instrumentation, and biological augmentation strategies continue to offer surgeons ways to manage historically "irreparable" meniscal tears. Root repair clinical outcomes are generally favorable, although patients may still experience progressive degenerative changes.

Medial Meniscus Posterior Root Tear Treatment: A Matched Cohort Comparison of Nonoperative Management, Partial Meniscectomy, and Repair

BACKGROUND

There are limited data comparing the outcomes of similarly matched patients with a medial meniscus posterior root tear (MMPRT) treated with nonoperative management, partial meniscectomy, or repair.

PURPOSE/HYPOTHESIS

The purpose was to compare treatment failure, clinical outcome scores, and radiographic findings for a matched cohort of patients who underwent either nonoperative management, partial meniscectomy, or transtibial pull-through repair for an MMPRT. We hypothesized that patients who underwent meniscus root repair will have lower rates of progression to arthroplasty than patients who were treated with nonoperative management or partial meniscectomy.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients who underwent transtibial medial meniscus posterior horn root repair were matched by meniscal laterality, age, sex, and Kellgren-Lawrence (K-L) grades to patients treated nonoperatively or with a partial meniscectomy. Progression to arthroplasty rates, International Knee Documentation Committee and Tegner scores, and radiographic outcomes were analyzed between groups.

RESULTS

Forty-five patients were included in this study (15 nonoperative, 15 partial meniscectomy, 15 root repair). Progression to arthroplasty demonstrated significant differences among treatment groups at a mean of 74 months (nonoperative, 4/15; partial meniscectomy, 9/15; meniscal repair, 0/15; P = .0003). The meniscus root repair group had significantly less arthritic progression, as measured by change in K-L grade from pre- to postoperatively (nonoperative, 1.0; partial meniscectomy, 1.1; meniscal repair, 0.1; P = .001).

CONCLUSION

Meniscus root repair leads to significantly less arthritis progression and subsequent knee arthroplasty compared with nonoperative management and partial meniscectomy in a matched cohort based on patient characteristics.

Increased rates of knee arthroplasty and cost of patients with meniscal tears treated with arthroscopic partial meniscectomy versus non-operative management

PURPOSE

The purpose of this study was to determine the cost of arthroscopic partial meniscectomy (APM), one of the most common surgeries performed by orthopaedic surgeons, and the associated rate of progression to knee arthroplasty (KA) compared to patients treated non-operatively after diagnosis of meniscal tear.

METHODS

Utilizing data mining software (PearlDiver, Colorado Springs, CO), a national insurance database of approximately 23.5 million orthopaedic patients was queried for patients diagnosed with a meniscal tear. Patients were classified by treatment: non-operative and arthroscopic partial meniscectomy and were followed after initial diagnosis for cost and progression to knee arthroplasty.

RESULTS

There were 176,407 subjects in the non-op group and 114,194 subjects in the arthroscopic partial meniscectomy group. Arthroscopic partial meniscectomy generated more cost than non-operative ($3842.57 versus $411.05, P < 0.001). Arthroscopic partial meniscectomy demonstrated greater propensity to need future knee arthroplasty (11.4% at 676 days) than those treated non-operatively (9.5% at 402 days) (P < 0.001). Female patients demonstrated a higher rate of progression to knee arthroplasty in the arthroscopic partial meniscectomy and non-operative groups (P < 0.001).

CONCLUSION

Compared to non-operative treatment for meniscal tears, arthroscopic partial meniscectomy is more expensive and does not appear to decrease the rate of progression to knee arthroplasty. Patients undergoing arthroscopic partial meniscectomy yielded on average a delay of only 9 months (274 days) before undergoing knee arthroplasty. Female patients experienced a significantly higher rate of progression to knee arthroplasty. The authors recognize the limitations of this type of study including its retrospective nature, reliance upon accurate coding and billing information, and the inability to determine whether symptoms including mechanical locking played a role in the decision to perform an APM.

LEVEL OF EVIDENCE

IV.