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

Diagnosis and Treatment Strategies of Meniscus Root Tears: A Scoping Review

Background

Meniscus root tears comprise 10% to 21% of all meniscal tears. These tears alter knee biomechanics, elevating contact pressure, akin to a meniscectomy. Consequently, they are linked to advanced joint degeneration and cartilage damage in the affected compartment.

Purpose

To systematically evaluate and relate the current literature describing the diagnosis and treatment strategies for meniscus root tears.

Study Design

Scoping review; Level of evidence, 4.

Methods

This review was conducted following the guidelines of the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) extension for scoping reviews. Inclusion criteria encompassed English-language clinical and preclinical research, technical notes, and narrative reviews on meniscus root tears. Exclusion criteria were studies on patellar tendon rupture, studies on medial patellofemoral ligament rupture with additional knee joint ligament injuries, studies of patients <16 years old, and studies involving open fractures. The data were summarized using a descriptive analysis and a thematic analysis.

Results

After 1425 articles were identified, 461 studies were included; 17% (n = 78) were case reports or case series, 15% (n = 71) were technical notes, 9% (n = 41) addressed aspects of diagnosis, 7% (n = 32 ) were narrative reviews, and 5% (n = 21) were systematic reviews or meta-analyses. Studies presenting original data comprised 57% (n = 262) of all included studies, and 97% of the studies were of evidence levels 3 to 5. Contributions were mainly from the United States (n = 123; 27%), Republic of Korea (n = 102; 22%), and Japan (n = 99; 21%). Many studies (n = 216; 47%) focused on the treatment and outcomes of meniscus root tears. A significant chronological surge in the quantity of studies addressing the diagnosis and treatment of meniscus root tears was evident, particularly over the past 3 years. Consensus was found regarding the definition of meniscus root tears, the advantages of early repair, and postoperative rehabilitation protocols. The variations in surgical techniques and operative strategies created the greatest amount of contention, along with clinical assessment and imaging modalities.

Conclusion

High-level evidence studies for diagnosing and managing meniscus root tears were scarce. A consensus has yet to be reached regarding the role of concomitant osteotomy, comparison of repair techniques, the use of a centralization stitch, patient factors affecting outcomes, and long-term outcomes of nonoperative management.

Risk factors of incomplete healing following medial meniscus posterior root tear repair with gracilis tendon

To evaluate the clinical efficacy and meniscus healing rates of the arthroscopically assisted tendon graft fixation of the medial meniscus posterior root tears (MMPRTs), and to identify some independent risk factors correlated with meniscal root healing status. We conducted a retrospective study with 129 patients who received arthroscopically assisted tendon graft fixation of the MMPRTs between January 2018 and September 2021. Functional recovery of the knee was evaluated and meniscal root healing status was assessed. The associations between different clinical factors and meniscal root healing status were analyzed. 98 (76.0%) patients had complete meniscal root healing with a minimum 2-year follow-up, and the Lysholm score, international knee documentation committee score, and visual analogue scale score were significantly improved at final follow-up (P < 0.001; respectively). Binary logistic regression models analysis and the receiver operating characteristic curve was performed to detect independent risk factors for incomplete healing, and these results indicated that age (OR = 1.095, P = 0.039), body mass index (BMI) (OR = 1.259, P = 0.018), preoperative meniscus extrusion (OR = 5.181, P < 0.001) and varus degree (OR = 7.764, P < 0.001) were the independent risk factors correlated with incomplete healing in patients with repaired MMPRTs. In conclusion, the arthroscopically assisted tendon graft fixation of the MMPRTs can provide good clinical and radiological outcome. Additionally, we identified age > 37.5 years, BMI > 24.5 kg/m2, preoperative meniscus extrusion > 2.7 mm and varus degree > 3.3° as independent risk factors correlated with incomplete meniscus root healing status.

Insufficient restoration of meniscal extrusion by transtibial pullout repair for medial meniscus posterior root tears

PURPOSE

The long-term changes in the dynamics of the medial meniscus after transtibial pullout repair for medial meniscus posterior root tears (MMPRTs) are not completely understood. Thus, the aim of this study was to investigate the effects of transtibial pullout repair on MMPRTs and whether the effects would be sustained.

METHODS

Nineteen knees with MMPRTs that were treated by trans-tibial pullout repair were enrolled in this study. Medial meniscus extrusion (MME) was measured by ultrasonography during knee extension (no weight-bearing with the knee at 0° extension: NW0°) and 90° flexion (no weight-bearing with the knee at 90° flexion: NW90°) with the patient in the supine position and with full weight-bearing (FW0°) preoperatively and at 3 and 12 months postoperatively. The clinical outcomes were assessed using the Knee Injury and Osteoarthritis Outcome Score, Lysholm score, and International Knee Documentation Committee score.

RESULTS

The difference in MME with NW0° was not statistically significant between the preoperative (3.4 ± 1.0 mm) and 12-month postoperative (3.7 ± 0.6 mm) time points. The MME with NW90° at 3 (2.1 ± 0.7 mm) and 12 months (2.9 ± 0.6 mm) postoperatively were significantly lower than the preoperative values (3.4 ± 0.8 mm) (P < 0.05). However, the value significantly increased from 3 to 12 months postoperatively (P < 0.05). The MME with FW0° at 12 months postoperatively (4.3 ± 0.6 mm) was significantly larger than that at pre-operatively (3.6 ± 0.9 mm) (P < 0.05). All the patients' clinical conditions were significantly improved at 12 months postoperatively when compared to their preoperative clinical conditions.

CONCLUSION

Surgery did not reduce the extrusion in the no weight-bearing and weight-bearing positions at knee extension, and these values increased in the postoperative period. In addition, while the surgery reduced the extrusion in the knee flexion position, the restoration achieved by the surgery was not sustained in the long term.

LEVEL OF EVIDENCE

Level IV.

Type of medial meniscus tear does not affect the clinical and radiological outcomes of medial opening-wedge high tibial osteotomy

PURPOSE

The current study aimed to evaluate the effect of medial meniscus posterior root tear (MMPRT) on radiological and clinical outcomes after medial opening-wedge high tibial osteotomy (MOWHTO).

METHODS

This retrospective cohort study included patients who underwent MOWHTO (113 knees) at our hospital between September 2012 and June 2020 and who were followed up for > 2 years. The radiological and clinical outcomes were compared between the MMPRT group (52 knees), who included patients with MMPRT, and the non-MMPRT group (61 knees), who comprised patients without meniscal tear or with any type of meniscal tear other than MMPRT. Logistic regression analysis was performed to evaluate factors affecting osteoarthritis (OA) progression after MOWHTO.

RESULTS

The mean follow-up period was 40.6 ± 14.2 months. The mean ages of the MMPRT and non-MMPRT groups were 56.9 ± 6.4 and 54.4 ± 6.1 years, respectively (p = 0.031). There was no significant difference in the last follow-up radiological and clinical outcomes between the two groups. In the logistic regression analysis, the postoperative hip-knee-ankle angle was a risk factor of OA progression after MOWHTO (odds ratio 0.7; 95% confidence interval 0.5-0.9; p = 0.006), and the type of medial meniscus tear was not associated with OA progression (p = n.s.).

CONCLUSIONS

In the short- to mid-term follow-up of MOWHTO, the radiological or clinical outcomes of patients with MMPRT were not inferior to those of patients without MMPRT. Postoperative lower extremity alignment, but not MMPRT, was a factor influencing MOWHTO prognosis. Concurrent root repair in HTO will restore the anatomy better; however, its effect on progression of OA is yet to be proven.

LEVEL OF EVIDENCE

IV.

Meniscal Extrusion Measurements After Posterior Medial Meniscus Root Tears: A Systematic Review and Meta-analysis

BACKGROUND

Meniscal extrusion has become increasingly utilized when evaluating meniscus root abnormalities. However, no consensus definition or approach exists on how to measure extrusion.

PURPOSE/HYPOTHESIS

The purpose of this study was to evaluate the extent of heterogeneity in meniscal extrusion measurement techniques and reported extrusion values in knees with posterior medial meniscus root tears (PMMRTs). We hypothesized that meniscal extrusion measurement techniques would vary considerably throughout reported studies, with resultant wide-ranging published extrusion values.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. The inclusion criteria consisted of all clinical and cadaveric studies reporting on meniscal extrusion after PMMRTs, excluding studies lacking data in full extension, those presenting only semiquantitative analyses, articles reporting only differences in meniscal extrusion, and review articles.

RESULTS

A total of 45 studies were included. Imaging modality types included magnetic resonance imaging (89%), 3-dimensional reconstruction with computed tomography (7%), linear displacement transducers (2%), and a combination of magnetic resonance imaging and ultrasound (2%). The 3 most commonly used landmarks to acquire coronal images for meniscal extrusion measurements were the medial collateral ligament (38%), the midpoint of the anterior-posterior length of the medial meniscus (23%), and the middle of the medial femoral condyle (19%). The pooled mean extrusion values according to the measurement location were 3.5 ± 0.7 mm, 3.9 ± 0.8 mm, and 4.5 ± 2.1 mm, respectively, with no significant differences noted between the modality types (P = .23). The pooled mean meniscal extrusion from all included studies was 3.2 ± 2.0 mm.

CONCLUSION

Substantial variation exists in measurement techniques for meniscal extrusion, particularly as it relates to the coronal cross-sectional reference location. Further studies should aim to provide clear descriptions of the measurement method and have uniform measurement methodology to allow comparisons and pooling between studies.

Repair of meniscus root tear - Is there a difference between medial meniscus root repair and lateral meniscus root repair? A systematic review and meta-analysis

PURPOSE

Complete meniscus root tear is associated with meniscus extrusion; this causes a loss of meniscus function and accelerated osteoarthritis of the knee. Existing small-scale retrospective case-control studies suggested that the outcomes were different between medial and lateral meniscus root repair. This meta-analysis aims to study whether such discrepancies exist via a systematic review of the available evidence in the literature.

METHODS

Studies evaluating the outcomes of surgical repair of posterior meniscus root tears, with reassessment MRI or second-look arthroscopy, were identified through a systematic search of PubMed, Embase, and Cochrane Library. The degree of meniscus extrusion, healing status of the repaired meniscus root, and functional outcome scores after repair were the outcomes of interest.

RESULTS

Among the 732 studies identified, 20 studies were included in this systematic review. 624 knees and 122 knees underwent MMPRT and LMPRT repair, respectively. The amount of meniscus extrusion following MMPRT repair was 3.8 ± 1.7 mm, which was significantly larger than the 0.9 ± 1.2 mm observed after LMPRT repair (p < 0.001). Significantly better healing outcomes were observed on reassessment MRI after LMPRT repair (p < 0.001). The postoperative Lysholm score and IKDC score was also significantly better after LMPRT than MMPRT repair (p < 0.001).

CONCLUSIONS

LMPRT repairs resulted in significantly less meniscus extrusion, substantially better healing outcomes on MRI, and superior Lysholm/IKDC scores, when compared to MMPRT repair. This is the first meta-analysis we are aware of that systematically reviews the differences in the clinical, radiographic, and arthroscopic results of MMPRT and LMPRT repair.

High tibial osteotomy for medial meniscus posterior root tears in knees with moderate varus alignment can achieve favorable clinical outcomes

Purpose

Favorable clinical results have been reported following high tibial osteotomy (HTO) for medial meniscus posterior root tear (MMPRT) in knees with varus alignment. However, the effect on the preoperative neutral alignment of the knee is not known. This study sought to evaluate the clinical outcomes of medial open-wedge HTO for MMPRT with neutral alignment.

Methods

We retrospectively reviewed 119 medial open-wedge HTOs and analyzed 22 knees with MMPRT. The knees were divided according to the preoperative hip-knee-ankle angle into a moderate varus alignment group (≤4° of varus alignment) and a varus alignment group (> 4° of varus alignment). The Knee Injury and Osteoarthritis Outcome Score (KOOS) and Forgotten Joint Score-12 (FJS-12) values were evaluated preoperatively and at the latest follow-up. The healing status of MMPRT at the time of second-look arthroscopy, performed at a mean of 15.4 ± 4.2 months, was compared with that after the primary HTO.

Results

There were 11 knees in the moderate varus alignment group and 11 in the varus alignment group. In terms of perioperative patient-reported outcome measures, there was no significant difference in the preoperative or postoperative KOOS subscale score or FJS-12 score between the moderate varus and varus alignment groups. The healing rate was significantly higher in the moderate varus alignment group.

Conclusion

Favorable clinical results were obtained by medial open-wedge HTO in knees with MMPRT and moderate varus alignment in the short term. Surgeons should consider the indications for medial open-wedge HTO, even with moderate varus alignment, when planning treatment for MMPRT with persistent knee pain.

Level of evidence

IV

Supplementary Information

The online version contains supplementary material available at 10.1186/s40634-022-00504-9.