Time-Dependent Increase in Medial Meniscus Extrusion after Medial Meniscus Posterior Root Tear Analyzed by Using Magnetic Resonance Imaging

PURPOSE: Medial meniscus posterior root tear (MMPRT) causes progression of medial meniscus extrusion (MME). This study aims to calculate the progression rate of MME based on findings in two preoperative magnetic resonance imaging (MRI) scans and determine the associated factors. MATERIALS AND METHODS: We retrospectively reviewed 33 patients (27 females and 6 males; mean age, 60 years) who underwent MRI twice, at a mean interval of 48 days. We measured the medial meniscus body width, medial joint space width (MJSW), and MME. The MME progression rate was derived from regression analysis of the increase in MME (ΔMME) between the two MRI scans. In addition, the correlations of the MME increase rate with age, body mass index, femorotibial angle, and MJSW were evaluated. RESULTS: The mean MME increased from 3.4 mm to 4.5 mm (p<0.001). A good correlation was observed between ΔMME and the interval of MRI scans (R²=0.621), and the MME progression rate was 0.020 mm per day. A moderate correlation was observed between the MME increase rate and the MJSW (R²=0.432). CONCLUSIONS: The MME progression rate was rapid in MMPRT and narrowing of the MJSW was associated with the progression of MME. LEVEL OF EVIDENCE: V, Cross-sectional study

Clinical and Radiological Results with Second-Look Arthroscopic Findings after Open Wedge High Tibial Osteotomy without Arthroscopic Procedures for Medial Meniscal Root Tears

PURPOSE: To identify the structural integrity of the healing site after medial open wedge high tibial osteotomy (MOWHTO) in patients with a posterior root tear of the medial meniscus (PRTMM) and chondral lesion by second-look arthroscopy and to determine the clinical and radiological findings. MATERIALS AND METHODS: From August 2010 to June 2016, 52 consecutive patients underwent MOWHTO and arthroscopic examination without a chondral resurfacing procedure and meniscal treatment for PRTMM. Twenty-four patients were available for second-look arthroscopic evaluation. The mean follow-up period was 19.5 months (range, 5 to 46 months). Clinical evaluation was based on the Lysholm knee scores and Hospital for Special Surgery (HSS) scores. RESULTS: There were 5 lax healing, 6 scar tissue, 13 failed healing of PRTMM. Definite change of chondral lesion was not observed. The Kellgren-Lawrence grade did not improve according to the follow-up plain radiograph. The mean Lysholm score improved from 34.7 preoperatively to 77.1 at the last follow-up, and the mean HSS score significantly increased from 36.5 to 82.4. CONCLUSIONS: This study revealed a low rate of healing potency of PRTMM and chondral lesion after MOWHTO without any attempt for meniscal treatment or chondral resurfacing. The cartilage and healing status of PRTMM was not associated with improved clinical outcomes and radiological findings.

Medial Meniscal Root Repair Using Curved Guide and Soft Suture Anchor

Medial meniscal root tears have been repaired using various methods. Arthroscopic all-inside repair using a suture anchor is one of the popular methods. However, insertion of the suture anchor into the proper position at the posterior root of the medial meniscus is technically difficult. Some methods have been reported to facilitate suture anchor insertion through a high posteromedial portal, a posterior trans-septal portal, or a medial quadriceptal portal. Nevertheless, many surgeons still have difficulty during anchor insertion. We introduce a technical tip for easy suture anchor insertion using a 25° curved guide and a soft suture anchor through a routine posteromedial portal.

The Optimal Suture Site for the Repair of Posterior Horn Root Tears: Biomechanical Evaluation of Pullout Strength in Porcine Menisci

PURPOSE: There are few studies on biomechanical evaluation of suture points in repair of root tears. The purpose of this study was to determine the point of greatest pullout strength for root tear repair. MATERIALS AND METHODS: A total of 120 fresh porcine medial menisci were obtained. The red-red and red-white zones of the meniscus were divided by two lines designated as lines A and B (groups A and B). Groups A and B were further divided into three groups each by dividing lines A and B into three points: 3, 5, and 7 mm from the meniscal ligament root insertion. Vertical meniscal repair was performed on each point. The pullout failure strength was tested using a biaxial servohydraulic testing machine. RESULTS: The average maximal load at failure was significantly greater in group A than group B (87.65 vs. 62.93; p<0.001) The average length at maximal load failure was greater in group A than group B (4.35 vs. 3.2; p<0.001). Among the subgroups of 3, 5, and 7 mm in both groups A and B, 7 mm showed the greatest maximal load (p<0.001). CONCLUSIONS: The pullout strength was statistically significantly greater in group A than group B and in the 7 mm subgroup than the 3 and 5 mm subgroups. Thus, the 7 mm subgroup in group A showed the greatest pullout strength.

Clinical Evaluation of the Root Tear of the Posterior Horn of the Medial Meniscus in Total Knee Arthroplasty for Osteoarthritis

PURPOSE: To investigate the incidence of root tears of the posterior horn of the medial meniscus in total knee replacement arthroplasty for knee osteoarthritis and retrospectively analyze clinical results and factors associated with root tears. MATERIALS AND METHODS: There were 197 knees of 140 enrolled patients who had undergone total knee replacement arthroplasty between September 2010 and May 2014. The presence of a root tear of the posterior horn of the medial meniscus was confirmed in all patients. Statistical analysis was performed to investigate the correlation between root tears and the possible factors of meniscal tears including gender, age, severity of symptoms (visual analogue scale [VAS] score and medial joint line tenderness), grade of osteoarthritis (Kellgren-Lawrence grading scale), body mass index (BMI), varus deformity, and mechanical axis deviation. RESULTS: Meniscal tears were observed in 154 knees (78.17%). The root tear had correlation with the severity of osteoarthritis (p<0.05), varus deformity (p<0.05), mechanical axis deviation (p<0.05), and BMI (p<0.05). CONCLUSIONS: Factors considered to represent the severity of osteoarthritis were found to be associated with root tears of the medial meniscus posterior horn. Increased BMI seemed to be associated with the increased incidence of root tears of the medial meniscus posterior horn.

Diagnosis and Current Trends of Medial Meniscus Posterior Root Tear / 대한정형외과학회잡지

Medial meniscal root tears with extrusion result in the loss of transmission of circumferential hoop stresses, leading to significantly increased tibiofemoral contact pressure and changes in knee biomechanics and kinematics. Therefore, medial meniscal root tears have attracted attention in recent years with regard to their early diagnosis. With the remarkable development of magnetic resonance imaging and arthroscopy, early diagnosis of medial meniscal root tears is on the rise. This report includes diagnosis and current trends of medial meniscal root tears.

Arthroscopic Medial Meniscus Posterior Root Repair: Techniques and Current Issues / 대한정형외과학회잡지

Posterior root tears of the medial meniscus are radial tears, usually found in patients older than 50 years with degenerative articular cartilage. Partial menisectomy has been the conventional treatment for this condition. However, growing dissatisfaction with partial menisectomy for medial meniscus root tears has led to an increasing interest in meniscal repair. One method for medial meniscus root repairs involves suturing around the region of the tear where the sutures are pulled-out and fixed around the tibia. In another approach, a suture anchor was used for fixation of the medial meniscus root tear. Both methods improved functional outcome scores at least during a short-term follow-up period. However, complete healing of the repaired root seemed to be less predictable. Strict patient selection, good surgical skills and proper postoperative rehabilitation are the key factors for successful repairs of medial meniscus root tears.

Non-Operative Treatment of the Degenerative Medial Meniscus Posterior Root Tear / 대한정형외과학회잡지

Degenerative medial meniscus posterior root tear is commonly seen in middle or old age populations. Because the biomechanical status of the meniscus root tear is similar to total menisectomy state, medial meniscus posterior root tear can cause early osteoarthritis. Treatment options for the medial meniscus posterior root tear include non-operative treatment, meniscectomy, repair, and high tibia osteotomy. There is still debate regarding the exact indication of each treatment, because the natural course of the medial meniscus posterior root tear and long-term results of each treatment is not known. However, non-operative treatments provide symptomatic relief and functional improvement in patients who are not indicated for operative treatment or before operative treatment.

Medial Meniscus Posterior Root Tear: A Comprehensive Review

Damage to the medial meniscus root, for example by a complete radial tear, destroys the ability of the knee to withstand hoop strain, resulting in contact pressure increases and kinematic alterations. For these reasons, several techniques have been developed to repair the medial meniscus posterior root tear (MMPRT), many of which have shown complete healing of the repaired MMPRT. However, efforts to standardize or optimize the treatment for MMPRT are much needed. When planning a surgical intervention for an MMPRT, strict surgical indications regarding the effect of pullout strength on the refixed root, bony degenerative changes, mechanical alignment, and the Kellgren-Lawrence grade should be considered. Although there are several treatment options and controversies, the current trend is to repair the MMPRT using various techniques including suture anchors and pullout sutures if the patient meets the indications. However, there are still debates on the restoration of hoop tension and prevention of arthritis after repair and further biomechanical and clinical studies should be conducted in the future. The aim of this article was to review and summarize the recent literature regarding various diagnosis and treatment strategies of MMPRT, especially focusing on conflict issues including whether repair techniques can restore the main function of normal meniscus and which is the best suture technique to repair the MMPRT. The authors attempted to provide a comprehensive review of previous studies ranging from basic science to current surgical techniques.

Second-Look Arthroscopic Assessment and Clinical Results of Modified Pull-Out Suture for Posterior Root Tear of the Medial Meniscus

PURPOSE: To identify the structural integrity of the healing site after arthroscopic repair of a posterior root tear of the medial meniscus by second-look arthroscopy and to determine the clinical relevance of the findings. MATERIALS AND METHODS: From January 2005 to December 2010, 20 consecutive patients underwent arthroscopic modified pull-out suture repair for a posterior root tear of the medial meniscus. Thirteen patients were available for second-look arthroscopic evaluation. The healing status of the medial meniscus was classified as complete healing, lax healing, scar tissue healing, and failed healing. We evaluated the correlation between the clinical symptoms and second-look arthroscopic findings. Clinical evaluation was based on the Lysholm knee scores and Hospital for Special Surgery (HSS) scores. RESULTS: There were 4 cases of complete healing, 4 lax healing, 4 scar tissue healing, and 1 failed healing. The healing status of the repaired meniscus appeared to be related to the clinical symptoms. Patients who achieved complete tissue healing had no complaint. The healing status exhibited no relationship with age, mechanical axis, degree of subluxation, and symptom duration. The mean Lysholm score improved from 34.7 preoperatively to 75.6 at follow-up and the mean HSS score also significantly increased from 33.5 to 82.2. CONCLUSIONS: We achieved 4 complete and 8 partial healing (lax or scar) of the medial meniscus in this retrospective case series of posterior horn meniscus root repairs performed by 1 surgeon. Further research is needed to clarify why all patients showed clinical improvement despite findings of partial healing on second-look arthroscopy.

Second-Look Arthroscopic Results after Repair of Medial Meniscus Root Tears / 대한정형외과학회잡지

PURPOSE: The purpose of this study is to evaluate the healing rate of medial meniscus root repair according to the duration of symptom and to determine the association between healing status and the clinical result after medial meniscus root repair. MATERIALS AND METHODS: Eighty-four patients who underwent arthroscopic meniscal root repair and second-look arthroscopy were included. Second-look arthroscopy evaluation of meniscal healing status was performed by dividing medial meniscal posterior root into the anterior half and posterior half and classifying by contact degree on the surface of the tibia and continuity. Clinical results were analyzed according to International Knee Documentation Committee (IKDC) subjective scores and Lysholm scores. In addition, after dividing cases according to acute group and chronic group by six-month symptomatic period, differences were evaluated. RESULTS: Significant differences in post-operative clinical results were observed between the acute group and chronic group. A significant difference in meniscal healing status was observed between the two groups (p<0.001). A higher postoperative IKDC score and Lysholm score was observed for the completely healed group, as confirmed by second-look arthroscopy, than for the other groups. CONCLUSION: In the aspect of improving the clinical result, arthroscopic medial meniscal posterior root repair is a good treatment modality. Early repair of medial meniscal posterior root may lead to improvements in the clinical result such as meniscal healing status.

Modified Pull-out Suture in Posterior Root Tear of the Medial Meniscus: Using a Posteromedial Portal

In cases with root tear of the medial meniscus posterior horn, the meniscus usually can be repaired by a pull out suture technique. However, there is difficulty in manipulating a suture hook via the anteromedial portal and looking through the arthroscopic camera via anterolateral portal in the narrow medial joint space at the same time. This article describes a modified simple pull out suture technique for root tear of the medial meniscus posterior horn using a posteromedial portal that provides a safe and easy handling of the suture hook. Our indications of this technique used in patients with Outerbridge 1-2 arthritic change and minimal varus axis change. Benefits of this technique are simple, less invasive, and reduced operation time by simultaneous suture with a hook via posteromedial portal and pulling of a string with grasper. It may reduce the possibility of an additional chondral or meniscal injury.

Minimum 1 Year Results of Arthroscopic Pull-out Repair for Posterior Root Tear of Medial Meniscus / 대한스포츠의학회지

This study is to evaluate clinical and arthroscopic second-look results of arthroscopic repairs of posterior root tears of medial meniscus which may cause loss of circumferential hoop tension and extrusion of meniscus. From October 2006 to May 2009, fifty-eight patients (59 knees) underwent arthroscopic pull-out repairs. Clinical results were evaluated using Hospital for Special Surgery (HSS) score and International Knee Documentation Committee (IKDC) score for 12-month follow-up. Second-look arthroscopy was done to evaluate meniscal healing in 21 cases. Magnetic resonance imaging (MRI) was performed to assess status of repaired meniscus and tibial tunnel position in 9 patients. Average preoperative HSS score and IKDC score of 59 cases were 69.5 and 36.0, respectively. Average postoperative HSS score and IKDC score of 59 cases had been changed into 90.3 (p<0.001) and 66.8 (p<0.001), respectively. Second-look arthroscopies revealed complete or incomplete healing except one case. Two patients showed increased one grade according to the Kellgren-Lawrence radiologic classification system and others showed no change. Of 9 patients who performed MRI, six patients showed complete healing. The average position of tibial tunnel was 4.8 mm anterior and 5.7 mm medial to center of posterior cruciate ligament. Arthroscopic pull-out repair technique using transtibial tunnel seems to be simple and effective procedure for posterior root tear of medial meniscus. Further evaluation of arthroscopic repair of posterior root tear of medial meniscus should be needed to prove the effectiveness on the prevention of osteoarthritis of knee.

Evaluation of the Factors Affecting Root Tears of the Posterior Horn of the Medial Meniscus as Confirmed during Total Knee Arthroplasty

PURPOSE: We examined the incidence of root tear of the medial meniscus posterior horn among patients who had undergone total knee replacement and we analyzed the factors that cause this tear. MATERIALS AND METHODS: We enrolled 258 knees of 173 patients who had undergone total knee replacement from January 2008 to June 2009. The mean age was 68.8 (range: 50~87). There were 23 men (28 cases) and 150 women (230 cases). We performed statistical correlation analysis between the assumed causes of meniscal tears (age, gender, grade of osteoarthritis, the predisposition site, BMI and varus deformity) and root tears. RESULTS: Meniscal tears were observed in 182 cases (70.5%), and there were 18 cases (64.2%) of 28 cases and 164 cases (71.3%) of 230 cases in the men and women, respectively. Root tear had correlation with the severity of osteoarthritis (p=0.040) and varus deformity (p=0.030), but other underlying factors didn't show significant correlation (p>0.05). CONCLUSION: Root tears of the medial meniscus posterior horn in total knee arthroplasty were related to the severity of osteoarthritis and varus deformity, but active interventions are required whether or not there are predisposing factors that cause osteoarthritis.

MRI findings of Root Tear of Medial Meniscus

PURPOSE: This study was to elevate the accuracy of MRI diagnosis by means of inspection of the demonstrable findings of the root tear of medial meniscus. MATERIALS AND METHODS: From September 2003 to August 2004, MR images were obtained from 15 of 29 patients who had a root tear of medial meniscus on arthroscopic examination. Each sagittal, axial and coronal images was obtained. Of 15 patients, three were men and 12 were women. The mean age was 59.3 years. RESULTS: All of 15 patients were diagnosed as medial meniscus root tear. Sagittal images showed loss of shape and signal intensity. Axial images showed radial linear defect. And coronal images showed vertical linear defect. CONCLUSION: The characteristic findings from three planes of MRI were helpful for diagnosis of medial meniscus root tear.