Knee Flexion-induced Translation of Pullout Sutures Used in the Repair of Medial Meniscus Posterior Root Tears

Medial meniscus posterior root tears (MMPRTs) have recently attracted considerable interest in orthopedics. To date, no in vivo human study has investigated suture translation changes in repaired MMPRTs with different degrees of knee flexion. This study examined suture translation at various degrees of knee flexion in 30 patients undergoing medial meniscus posterior root repair using the modified Mason-Allen suture technique between August 2016 and September 2017. Intraoperatively, sutures were provisionally fixed to an isometric positioner at the tibial site of the desired meniscal attachment, and the suture translation was measured at 0°, 30°, 60°, and 90° of knee flexion. The results showed significant increases in mean suture translation at the knee flexion positions from 0° to 30°, 30° to 60°, and 60° to 90° (p<0.01 for all). Our findings indicate that surgeons should carefully assess the degree of knee flexion at the moment when the meniscus is refixed by surgical sutures

High body mass index is a risk factor for unfavorable clinical outcomes after medial meniscus posterior root repair in well-aligned knees

BackgroundSevere chondral lesions and varus knee alignment are associated with poor outcomes following transtibial pullout repair for medial meniscus posterior root tears and meniscus tear is strongly associated with body mass index. The prognostic factors in well-aligned knees (femorotibial angle  MethodsWe retrospectively reviewed the files of 28 patients who had undergone pullout repair of medial meniscus posterior root tears between October 2016 and December 2017. We recorded the baseline characteristics (age, gender, height, weight, and body mass index) and the time between injury and surgery. We recorded the International Knee Documentation Committee scores, Knee injury and Osteoarthritis Outcome Scores, and pain visual analog scale scores. Using magnetic resonance imaging preoperatively and 1 year after surgery, we measured the medial meniscus body width and absolute and relative medial meniscus extrusion. Pearson correlation and multivariate linear regression analyses were used to assess potential associations between these factors and clinical outcomes. ResultsAge positively correlated (coefficient = 0.49, P  ConclusionsBody mass index > 30 kg/m(2) is a risk factor for unfavorable clinical outcomes following pullout repair of medial meniscus posterior root tears in well-aligned knees. Level of evidenceIII, Comparative retrospective study

Histological Analysis of Repaired Tissue after Pullout Repair of a Medial Meniscus Posterior Root Tear

A 65-year-old man presented with a left medial meniscus (MM) posterior root tear (PRT). Unicompartmental knee arthroplasty was performed 12 months after transtibial pullout repair of the MMPRT. Repaired MM posterior root tissue was subjected to histological analysis. Immunostaining and picrosirius red staining showed sufficient deposition of type I collagen, and hematoxylin-eosin staining using a polarized microscope showed well-aligned fiber orientation in the repaired tissue. The repaired posterior root (post-transtibial pullout repair) showed mature and well-aligned ligament-like tissue. Preserving the MM posterior root remnant to mimic the original posterior root tissue might be useful when performing pullout repair

Effectivity of the Outside-In Pie-Crusting Technique and an All-Inside Meniscal Repair Device in the Repair of Ramp Lesions

Ramp lesions are characteristic medial meniscus injuries seen in anterior cruciate ligament-injured knees. Anterior cruciate ligament injuries combined with ramp lesions increase the amount of anterior tibial translation and tibial external rotation. Therefore, the diagnosis and treatment of ramp lesions have received increasing attention. However, ramp lesions can be difficult to diagnose on preoperative magnetic resonance imaging. Additionally, ramp lesions are difficult to observe and treat intraoperatively in the posteromedial compartment. Although good results have been reported with the use of a suture hook through the posteromedial portal in the treatment of ramp lesions, the complexity and difficulty of the technique are further problems. The outside-in pie-crusting technique is a simple procedure that can enlarge the medial compartment and facilitate the observation and repair of ramp lesions. After this technique, ramp lesions can be properly sutured, using an all-inside meniscal repair device, without damaging the surrounding cartilage. A combination of the outside-in pie-crusting technique and an all-inside meniscal repair device (with only anterior portals) is effective in the repair of ramp lesions. This Technical Note aims to report in detail the flow of a series of techniques, including our diagnostic and therapeutic methods

Time-Dependent Increase in Medial Meniscus Extrusion Predicts the Need for Meniscal Repair in Patients with Partial Medial Meniscus Posterior Root Tears: A Case–Control Study

Purpose　This study aimed to compare medial meniscus extrusion (MME) in patients with partial medial meniscus posterior root tears (MMPRTs) through magnetic resonance imaging (MRI) conducted at two-time points and to determine whether patient characteristics or MME measurements differ in patients who respond to nonoperative treatment compared with those who require surgical treatment. Methods　Thirty-seven patients with partial MMPRTs underwent two MRI scans during nonoperative management or before pull-out repair. Among these, 17 patients received nonoperative management, and 20 underwent pull-out repair. Partial MMPRTs were diagnosed based on the MRI findings. MME measurements were performed on both MRI scans. Statistical and receiver operating curve (ROC) analyses were performed. Results　The duration between the two MRI scans was significantly shorter in the pull-out repair group than in the nonoperative management group. The increase in MME (ΔMME) on MRI scans was significantly greater in the pull-out repair group than in the nonoperative management group. Linear regression analysis revealed a weak correlation between the MRI interval and ΔMME in the nonoperative management group and a moderate correlation in the pull-out repair group. In the ROC construction, the cut-off value for ΔMME that requires surgical intervention was 0.41 mm, with a sensitivity and specificity of 85.0% and 52.9%, respectively. Conclusion　Patients with partial MMPRTs requiring surgical treatment had greater MME progression in a shorter time and a time-dependent increase in MME. Therefore, a ΔMME of ≥ 0.41 mm may be useful in deciding surgical intervention based on MRI retests. Level of evidence　III

Clinical evaluation of suture materials for transtibial pullout repair of medial meniscus posterior root tear

Background: There are no recommendations for specific suture materials in transtibial pullout repair of medial meniscus posterior root tears. This study aimed to evaluate the clinical outcomes of transtibial pullout repair of medial meniscus posterior root tears using ultrahigh-molecular-weight polyethylene sutures and suture tape. Methods: We retrospectively reviewed the data of 36 patients (27 women and 9 men, mean age 64.1 years) who had undergone transtibial pullout repair of medial meniscus posterior root tears between November 2018 and December 2019. Two groups of 18 patients each received either two different cord-like sutures or suture tape. Clinical parameters were assessed preoperatively and on second-look arthroscopy (mean postoperative period 12 months). The meniscal healing status was assessed using a previously published scoring system (ranging from 0 to 10), and the incidence rate of suture cut-out was assessed on second-look arthroscopy. Results: All clinical scores significantly improved in both groups, with no significant between-group differences on second-look arthroscopy. The arthroscopic meniscal healing scores significantly differed between sutures (mean 6.7 points) and suture tape (mean 7.4 points; p = 0.044). No significant between-group difference in the suture cut-out rate was observed. Conclusions: This study found no significant differences in the clinical outcomes between ultrahigh-molecular-weight polyethylene sutures and suture tape. Favorable clinical outcomes were obtained using both types of suture; however, the usefulness of suture tape appears to be limited

Postoperative clinical outcomes of unicompartmental knee arthroplasty in patients with isolated medial compartmental osteoarthritis following medial meniscus posterior root tear

Background: Cartilage degradation progresses rapidly following medial meniscus posterior root tear (MMPRT). Unicompartmental knee arthroplasty (UKA) has been performed for medial compartmental osteoarthritis following MMPRT. We evaluated the clinical and radiographic outcomes of UKA for medial compartmental osteoarthritis after an untreated MMPRT. Methods: Twenty-one patients who underwent UKA for isolated medial compartment osteoarthritis following MMPRT were retrospectively investigated. Clinical outcomes were assessed using the Knee Injury and Osteoarthritis Outcome Score and knee range of motion. The posterior tibial slope and tibial component inclination were evaluated using plain radiographs. Results: The mean follow-up periods were 25.5 +/- 13.8 months. Clinical outcomes improved significantly postoperatively. The mean postoperative knee extension angle was-1.1 degrees +/- 2.1 degrees, and the knee flexion angle was 134.3 degrees +/- 4.9 degrees. The posterior tibial slope angle decreased from 9.0 degrees +/- 2.0 degrees preoperatively to 5.4 degrees +/- 1.8 degrees postoperatively, and postoperative tibial component inclination at the final follow-up was 2.9 degrees +/- 1.1 degrees varus. No aseptic loosening or deep infections were observed. Conclusion: UKA significantly improved clinical outcomes and could be a viable surgical option for treating isolated medial compartmental osteoarthritis accompanied by untreated MMPRT