The modified Nice knot has improved mechanical performance compared to the cinch stitch for meniscal root repair.

PURPOSE: According to previous biomechanical studies, the success of meniscus root repair depends on the suture-meniscus interface and optimisation of this procedure seems to be critical. A progressive, reliable and adjustable knot has numerous advantages in meniscal repair since the surgeon can adapt and meticulously tune the final strength of the fixation. We hypothesised that a single passage of one tape at two different points of the posterior meniscal root with a modified Nice knot configuration may allow similar or superior fixation for root repair compared to the cinch stitch suture technique. METHODS: Posterior root repair of medial and lateral meniscus was performed on 26 porcine knees. In group (A), two simple cinch stitches were applied, and in group (B), a modified Nice knot was used in a crossmatch configuration. For both groups, two passages through the meniscus with a 2-mm braided tape were used, and a single transosseous tibial tunnel technique was performed and tested in pull-out conditions. RESULTS: The modified Nice knot showed an improved biomechanical performance considering the maximum failure load for both the medial (600.7 ± 77.5 N) and lateral (686.1 ± 83.5 N) (p = 0.006) posterior root fixation when compared to a double cinch stitch (558.0 ± 123.9 N) and (629.0 ± 110.2 N) (p = 0.178) for medial and lateral fixation, respectively. The maximum stiffness was also higher for the modified Nice knot configuration for both medial (17.1 ± 1.5 vs. 13.3 ± 1.6 N/mm) and lateral meniscus (20.0 ± 2.6 vs. 13.8 ± 2.3 N/mm), being this difference statistically significative (p = 0.001). CONCLUSIONS: The modified Nice knot allowed better adaptation in the pull-out tests and presented higher fixation strength, stiffness and reproducibility, with lower standard deviation, being at the same time economically advantageous, since only one tape is needed. LEVEL OF EVIDENCE: Level III.

More than 3 mm of preoperative medial meniscal extrusion is identified as a key risk factor for varus progression in limb alignment after arthroscopic repair of medial meniscus posterior root tear.

PURPOSE: To investigate the risk factors for varus progression after arthroscopic medial meniscal posterior root tear (MMPRT) repair and to compare the clinical outcomes between two groups: one with more varus progression and the other with less varus progression. METHODS: Patients who underwent isolated arthroscopic repair of MMPRT between 2015 and 2020 were enroled, and 2-year follow-up data were collected. Participants were categorized into two groups based on preoperative values of the weight-bearing line (WBL) ratio: group A with <5.9% increase and group B with ≥5.9% increase. Various factors, including demographic features and radiological findings, were analysed and compared between the two groups. Intra-meniscal signal intensity, meniscal healing, medial meniscal extrusion (MME), and articular cartilage grade were assessed preoperatively and 1-year postoperatively using coronal magnetic resonance imaging. RESULTS: The final cohort consisted of 34 patients in group A and 46 in group B, with a mean age of 55.8 ± 11.2 and 59.8 ± 6.6 years, respectively. Preoperative WBL ratio and cartilage lesions in the medial compartment did not differ between the groups. Preoperative MME were significantly lower in group A than those in group B (2.6 ± 0.6 mm in group A and 3.5 ± 0.7 mm in group B, p < 0.05). Patient-reported outcomes at the 2-year follow-up did not differ between the two groups (n. s.). In a logistic analysis, the odds ratio of MME was 2.1 (p < 0.05), and the cutoff value of MME was 3.02 mm. CONCLUSION: Preoperative MME is a risk factor for varus progression. However, no differences in patient-reported outcomes were observed at 2-year follow-up, even in the group with greater varus progression. LEVEL OF EVIDENCE: Level IV.

Short-term results of tibial interference screw fixation for transtibial medial meniscus posterior root pull-out repair.

Background: To evaluate the technique of transtibial pull-out repair with tibial interference screw fixation for medial meniscus posterior root (MMPR) tear by reporting on short-term outcomes and complications. Methods: All MMPR repairs performed between January 2019 and August 2021 (n = 70) were retrospectively screened regarding demographic data and surgical parameters. The patients were questioned for performed revision surgery, symptoms and complications. The Numeric Rating Scale (NRS) for pain, Lysholm Knee Score and International Knee Documentation Committee Subjective Knee Form (IKDC) questionnaires were used to evaluate clinical outcome. In cases of revision surgery for re-tear the mode of failure was intraoperatively classified (patients with re-tear were excluded from the clinical follow-up examination). The influence of demographic and treatment parameters (surgical and rehabilitation) on the incidence and mode of re-tear and clinical scores was evaluated. Results: After 2.3 ± 0.7 years, 62 patients (88.6 %) were available for follow-up. There were no direct intra- or postoperative complications. No revision was performed due to symptoms related to the tibial fixation material. The mean surgery time was 33.5 ± 10.8 min. The overall re-tear rate was 17.7 % (11 patients) of whom 10 were treated surgically and one conservatively. Primary mode of failure was suture cut-out from the meniscus (70 %). The NRS, Lysholm Knee Score and subjective IKDC were obtained in 38 patients and improved from 6.8 ± 2.4, 40.1 ± 23.9 and 32.8 ± 16.3 to 2.2 ± 2.2, 80.5 ± 16.3 and 63.0 ± 13.9, respectively (all p < 0.001). No influence was observed from demographic and treatment parameters on re-tear rates or clinical Scores. Conclusions: Tibial interference screw fixation is a fast and promising technique for MMPR transtibial pull-out repair. In the presented technique, utilizing non-absorbable locking sutures alongside tibial interfenrence screw fixation, the primary mode of failure was suture cut-out from the meniscus.

Outcomes After Meniscal Root Repair in Patients With and Without Advanced Patellofemoral Chondromalacia: Comparison at 2-Year Follow-up.

Background: Meniscal root repair can improve patient outcomes significantly; however, several contraindications exist, including arthritic change to the medial or lateral tibiofemoral compartments. Purpose/Hypothesis: The purpose of this study was to evaluate the outcomes of meniscal root repair in patients with advanced patellofemoral chondromalacia (PFC). It was hypothesized that the presence of advanced PFC would not significantly affect the postoperative outcomes. Study Design: Cohort study; Level of evidence, 3. Methods: A retrospective review was conducted of patients who underwent meniscal root repair with at least 2 years of follow-up data. Patients with chondromalacia as determined by arthroscopic visualization (defined as Outerbridge grade 3 or 4) were placed in the PFC group; patients with Outerbridge grade 0 to 2 chondromalacia were placed in the non-PFC group. Outcomes were measured by the Lysholm knee scoring scale and the International Knee Documentation Committee (IKDC) Subjective Knee Form. Clinical outcomes including complications were also recorded. Quantitative data between the groups were analyzed using the 2-tailed independent-samples t test. Results: Overall, this study included 81 patients (35 in the PFC group, 46 in the non-PFC group). The mean follow-up times were 25.1 months in the PFC group and 24.8 months in the non-PFC group. In both groups, Lysholm and IKDC scores improved significantly with 24-month Lysholm scores averaging 85.86 in the PFC group and 86.61 in the non-PFC group (P = .62) and 24-month IKDC scores averaging 77.66 for the PFC group and 79.59 for the non-PFC group (P = .45). The cohorts demonstrated similar rates of retear, arthrofibrosis, infection, and progression to total knee arthroplasty. Conclusion: The presence of advanced PFC was not associated with inferior outcomes in patients who underwent posterior meniscal root repair, and rates of recurrent tears, postoperative infection, arthrofibrosis, and conversion to total knee arthroplasty were similar between the study groups. These findings suggest that PFC may not significantly alter the results of meniscal root repair and should not be considered an absolute contraindication for this procedure.

Prognostic Factors and Midterm Clinical Outcome of Transtibial Pullout and Partial Meniscectomy for Medial Meniscus Posterior Root Tears in Middle-Aged Patients.

Purpose: The purpose of this study was to compare clinical and radiological outcomes of transtibial pullout technique and partial meniscectomy, and to establish prognostic factors in middle-aged patients with mild knee osteoarthritis. Methods: A comparative case-control analysis was conducted. 65 patients between 40 and 60 years of age were included into two groups: 30 patients who underwent transtibial pullout technique (group 1) and 35 patients who underwent partial meniscectomy (group 2). Mean follow-up was set at 27.2 months. Primary clinical outcomes included Knee injury and Osteoarthritis Outcome Score and Lysholm Knee Questionnare. Preoperative MRI and intraoperative arthroscopic findings were recorded. The correlation between these findings and patient-reported subjective outcome were assessed. Results: The transtibial pullout group exhibited significantly greater improvement in clinical outcomes. A univariate model revealed that the presence of preoperative meniscal extrusion, body mass index (> 30), osteochondral defect, and female gender were predictors of poor clinical outcome. Multivariate regression analysis showed meniscal extrusion and osteochondral defect as significant prognostic factors for both study groups. Conclusion: Medial meniscus root repair leads to significantly improved clinical outcomes compared to partial meniscectomy in middle-aged patients with mild knee osteoarthritis. Presence of meniscal extrusion, osteochondral defect, BMI > 30, and female gender were deemed as predictors of poor postoperative patient-reported outcome. Level of Evidence: III therapeutic case-control study.

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.

Correlation of factors affecting correction of meniscal extrusion and outcome after medial meniscus root repair.

INTRODUCTION: Meniscus extrusion in medial meniscus posterior root tears (MMPRT) is a consistent MRI finding and correction of extrusion is a primary objective of the meniscal root repair. The purpose of the study is to evaluate feasibility of correction of extrusion and correlation of various factors affecting the postoperative extrusion correction and outcomes in all degenerative medial meniscus posterior roots (MMPRTs). METHODS: A retrospective study of patients who presented with degenerative MMPRTs following trivial incident (Jun 2014 and Aug 2018) and included isolated Laprade type 2 root tear with extrusion in MRI. Patients with ligament injuries, tricompartmental arthritis, malalignment (> 50) and irreparable meniscal tears excluded. All patients underwent arthroscopic trans-tibial tunnel suture pull-out repair. A screening MRI was taken at a 6-month follow-up and functional scores (IKDC and Lysholm's) at final follow-up. The effects of age, gender, duration of symptoms, hip-knee-ankle angle on weight-bearing X-rays, ICRS grading of cartilage status, and MRI data (extrusion distance, tunnel location and healing status of meniscus) on outcomes were analysed. RESULTS: MMPRT (n = 54) with a mean follow-up of 34.6 months (24-48). Mean functional outcomes improved postoperatively IKDC (43.40 ± 5.16-78.65 ± 5.11, p < 0.001) and Lysholm's (65.27 ± 4.28-83.16 ± 4.83, p < 0.001) scores at final follow-up. 57.4% (31) had good correction of extrusion, 3.7% (2) no correction and 38.8% (21) showed increase in extrusion postoperatively. Of all the factors we explored, age, ICRS (low grade) and knee varus (less 2.5 degree) affected extrusion correction. Patients with healed (41 patients), partially healed (9 patients) and anatomic tunnel placement (46 patients) had better extrusion correction than those with non-healing (4 patients) and non-anatomical tunnel (8 patients). CONCLUSION: Patients younger than 50 years, with low grade cartilage damage (ICRS 1, 2), lower KL grade and varus alignment (< 2.50) had good correction of extrusion. Correction of extrusion/progression of extrusion did not influence the clinical outcome at the short-term. The progression of meniscal extrusion is inevitable even after successful repair in elderly and high-risk patients. STUDY DESIGN: Retrospective Case series, level of evidence IV.

A comparison of the transtibial pullout technique and all-inside meniscal repair in medial meniscus posterior root tear: Prognostic factors and midterm clinical outcomes.

INTRODUCTION: There is a paucity of comparative clinical data between arthroscopic all-inside end-to-end meniscal root suture and transtibial pullout technique in medial meniscus posterior root tears (MMPRT). Therefore, this study aimed to compare treatment failure, mid-term clinical and radiological outcomes of all-inside meniscus root repair versus the transtibial pullout technique and to analyze prognostic factors of postoperative clinical and radiological outcomes. MATERIAL AND METHODS: Forty-four patients were included in two therapeutic group: arthroscopic all-inside meniscal suture (MS: 13 knees) and transtibial pullout technique (TP: 31 knees).Primary clinical outcomes at a minimum of 27.2 months postoperatively included Knee injury and Osteoarthritis Outcome Score (KOOS) and Lysholm Knee Questionnare (LKQ). Radiographic assessment of the knee was performed to determine osteoarthritis severity using the Kellgren-Lawrence (KL) grading system.In addition, pre and postoperative MRI scans and intraoperative arthroscopic findings were recorded and the correlations between these findings, as outcome predictors and postoperative patients reported subjective outcome were assessed. RESULTS: No significant differences in postoperative KOOS and LKQ scores were found between the MS and TP group (p = 0.38 and 0.17, respectively).During follow-up one patients (7.7%) in the MS group and two (6.5%) in the TP group underwent total knee arthroplasty. The difference did not reach the statistical significance (p = 0.88).No differences were observed in postoperative MRI findings such as meniscal extrusion, osteochondral defect, chondromalacia patella, and bone morrow edema (p = 0.25, 0.97, 0.97, and 0.88, respectively).A univariate model revealed that the presence of postoperative meniscal extrusion; osteochondral defect; chondromalacia patella; increased BMI; age (>40 years) and longer time lapse between clinical onset to surgery (>6 months) were predictors of poor clinical outcome. The presence of meniscal extrusion, osteochondral defect and chondropatia patella portended worst postoperative outcomes in a multiple linear regression model. CONCLUSIONS: It can be concluded that both techniques can reach good results when performed properly and if the injury pattern allows meniscal suture may be considered a treatment option for the management of MMPRT in well-selected patients.Patients with increased BMI, preoperative meniscal extrusion, chondromalacia patella, and osteochondral defect were at higher risk of poor clinical outcomes.

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.

Knotless Anchor Fixation for Transosseous Meniscal Root Repair Using Suture Tape Is Inferior Compared With Button or Screw Fixation: A Biomechanical Study.

BACKGROUND: A 2 mm-wide ultrahigh-molecular-weight polyethylene (UHMWPE) tape improves the contact pressure at root repair sites compared with high-strength suture and provides a stronger repair construct. UHMWPE tape is commonly used in rotator cuff repair, and fixation is often achieved with knotless suture anchors. The optimal method for tape fixation for meniscal root repair has not been established. HYPOTHESIS: The use of suture anchors for the tibial fixation of 2-mm UHMWPE tape transosseous root repairs will lead to better biomechanical performance compared with other fixation methods. METHODS: The medial meniscal posterior root attachment in 25 porcine knees was divided, and a standardized transtibial root repair was performed using 2-mm UHMWPE tape. The testing was performed by cyclic loading followed by load to failure. Tibial fixation was randomized to 5 tibial fixation types: (1) cortical fixation button, (2) pound-in suture anchor with screw-down interference suture locking, (3) tap-in suture anchor with inner locking plug, (4) postscrew, and (5) postscrew and washer. RESULTS: There was no difference in displacement during cyclic loading between tibial fixation groups except for a highly significant difference in the maximum load at failure. Repairs in both suture anchor fixation groups all failed by tape slippage at relatively low loads (median, 145 and 116 N, respectively). Repairs tied over a cortical button, postscrew, or screw and washer failed by tape breakage at loads of 431, 405, and 528 N. CONCLUSION: For meniscal root repairs with 2-mm UHMWPE tape, use of suture anchors offers weaker fixation compared with tying over a button or postscrew/washer. While suture anchor fixation may be adequate for nonweightbearing postoperative protocols, it may not allow for more accelerated weightbearing.

Arthroscopic direct meniscal extrusion reduction: surgical tips to reduce persistent meniscal extrusion in meniscal root repair.

Meniscal extrusion (ME) is defined as extension of the meniscal margin by at least 3 mm beyond the tibial margin. The main purpose of meniscal root repair is to restore the anatomy and function of the meniscus. Therefore, the reduction in the ME is one of the important objective outcomes. Nevertheless, the reduced meniscal extrusion was obtained in limited patients after meniscal root repair. This technical note described the arthroscopic direct meniscal extrusion reduction as surgical tips to reduce persistent meniscal extrusion in posterior meniscal root repair.

The Strength of Transosseous Medial Meniscal Root Repair Using a Simple Suture Technique Is Dependent on Suture Material and Position.

BACKGROUND: A simple suture technique in transosseous meniscal root repair can provide equivalent resistance to cyclic load and is less technically demanding to perform compared with more complex suture configurations, yet maximum yield loads are lower. Various suture materials have been investigated for repair, but it is currently not clear which material is optimal in terms of repair strength. Meniscal root anatomy is also complex; consisting of the ligamentous mid-substance (root ligament), the transition zone between the meniscal body and root ligament; the relationship between suture location and maximum failure load has not been investigated in a simulated surgical repair. HYPOTHESES: (A) Using a knottable, 2-mm-wide, ultra-high-molecular-weight polyethylene (UHMWPE) braided tape for transosseous meniscal root repair with a simple suture technique will give rise to a higher maximum failure load than a repair made using No. 2 UHMWPE standard suture material for simple suture repair. (B) Suture position is an important factor in determining the maximum failure load. STUDY DESIGN: Controlled laboratory study. METHODS: In part A, the posterior root attachment of the medial meniscus was divided in 19 porcine knees. The tibias were potted, and repair of the medial meniscus posterior root was performed. A suture-passing device was used to place 2 simple sutures into the posterior root of the medial meniscus during a repair procedure that closely replicated single-tunnel, transosseous surgical repair commonly used in clinical practice. Ten tibias were randomized to repair with No. 2 suture (Suture group) and 9 tibias to repair with 2-mm-wide knottable braided tape (Tape group). The repair strength was assessed by maximum failure load measured by use of a materials testing machine. Micro-computed tomography (CT) scans were obtained to assess suture positions within the meniscus. The wide range of maximum failure load appeared related to suture position. In part B, 10 additional porcine knees were prepared. Five knees were randomized to the Suture group and 5 to the Tape group. All repairs were standardized for location, and the repair was placed in the body of the meniscus. A custom image registration routine was created to coregister all 29 menisci, which allowed the distribution of maximum failure load versus repair location to be visualized with a heat map. RESULTS: In part A, higher maximum failure load was found for the Tape group (mean, 86.7 N; 95% CI, 63.9-109.6 N) compared with the Suture group (mean, 57.2 N; 95% CI, 30.5-83.9 N). The 3D micro-CT analysis of suture position showed that the mean maximum failure load for repairs placed in the meniscus body (mean, 104 N; 95% CI, 81.2-128.0 N) was higher than for those placed in the root ligament (mean, 35.1 N; 95% CI, 15.7-54.5 N). In part B, the mean maximum failure load was significantly greater for the Tape group, 298.5 N ( P = .016, Mann-Whitney U; 95% CI, 183.9-413.1 N), compared with that for the Suture group, 146.8 N (95% CI, 82.4-211.6 N). Visualization with the heat map revealed that small variations in repair location on the meniscus were associated with large differences in maximum failure load; moving the repair entry point by 3 mm could reduce the failure load by 50%. CONCLUSION: The use of 2-mm braided tape provided higher maximum failure load than the use of a No. 2 suture. The position of the repair in the meniscus was also a highly significant factor in the properties of the constructs. CLINICAL RELEVANCE: The results provide insight into material and location for optimal repair strength.

Increased extrusion and ICRS grades at 2-year follow-up following transtibial medial meniscal root repair evaluated by MRI.

PURPOSE: The purpose of the current study was to evaluate the short-term results of meniscal root repair surgery, assessing clinical and radiographic outcomes, utilizing MRI to assess root healing and extent of post-operative extrusion. METHODS: This was a single-center, retrospective study evaluating patients who had undergone a medial meniscus posterior root repair using a transtibial pullout technique with two locking cinch sutures. Demographic data were collected from patient charts. Clinical outcomes were assessed with pre- and post-operative IKDC and Lysholm scores. Pre-op scores were taken at the patients' initial clinical visit, mean 1.55 months prior to surgery (± 1.8 months, min 0.3, max 7.3). Radiographic outcomes were assessed with MRI evaluation of root healing, meniscal extrusion, and cartilage degeneration using ICRS criteria. Tunnel placement was evaluated and compared to the anatomic footprint. RESULTS: Eighteen patients (47.2 years ± 11.9) were evaluated at mean follow-up of 24.9 months (± 7.2, min 18.4, max 35.6). The IKDC score significantly increased from 45.9 (± 12.6) pre-operatively to 76.8 (± 14.7) post-operatively (p < 0.001). Lysholm scores also increased from 50.9 (± 7.11) to 87.1 (± 9.8) (p < 0.001). Mean tunnel placement was 5.3 mm (± 3.5, range 0-11.8) away from the anatomic footprint. Mean extrusion increased from 4.74 mm (± 1.7) pre-operatively to 5.98 (± 2.8) post-operatively (p < 0.02). No patients with > 3 mm of extrusion on pre-operative MRI had < 3 mm of extrusion on post-operative MRI. Both medial femoral condyle and medial tibial plateau ICRS grades worsened significantly (p < 0.02 and p < 0.01, respectively). On MRI, one root appeared completely healed, 16 partially healed, and one not healed. CONCLUSION: Patients treated with the transtibial suture pull-out technique with two locking cinch sutures had improved clinical outcomes, but only partial healing in the majority of cases, increased extrusion, and progression of medial compartment cartilage defect grade on follow-up MRI. Patients should be counseled that although clinical outcomes in the short term may be optimistic, long-term outcomes regarding progression to degenerative arthritis may not be as predictable. CLINICAL LEVEL OF EVIDENCE: III.

Three single loops enhance the biomechanical behavior of the transtibial pull-out technique for posterior meniscal root repair.

PURPOSE: To investigate the effect of applying an additional suture to enhance the biomechanical behavior of the suture-meniscus construct used during the transtibial pull-out repair technique. METHODS: A total of 20 fresh-frozen porcine tibiae with intact medial menisci were used. In one half of all specimens (N = 10), two non-absorbable sutures were passed directly over the meniscal root from the tibia side of the meniscus to the femoral side (2SS). In other ten specimens, three sutures were passed over the meniscal root (3SS). All specimens were subjected to cyclic loading followed by load-to-failure testing. Displacement of the construct was recorded at 100, 500, and 1000 cycles. Further, stiffness (500-1000 cycles) and ultimate load and modes of failure of the suture-meniscus construct were also recorded. RESULTS: There was no statistically significant difference between the Group 2SS and Group 3SS at the 1st (1.6 ± 0.7 vs 1.4 ± 0.4 mm) and the 100th cycle (2 ± 0.7 vs 1.8 ± 0.4 mm). At 500 and 1000 cycles, the 2SS fixation technique resulted in significantly more displacement than the 3SS fixation technique (2.8 ± 0.6 vs 2.3 ± 0.5 mm; 3.1 ± 0.7 vs 2.5 ± 0.5 mm) (p < 0.05). No differences between two groups were noted concerning ultimate load to failure and stiffness (500-1000 cycles). CONCLUSION: Three single sutures technique provided superior biomechanical properties compared with the two single sutures technique during the conducted fatigue tests. CLINICAL RELEVANCE: Applying three simple stitches during meniscal root repair might be beneficial for healing of the posterior meniscal root, potentially reducing the post-operative immobilization time.

Rehabilitation Following Meniscal Root Repair: A Clinical Commentary.

SYNOPSIS: There is a growing body of evidence surrounding the pathology and treatment of meniscal root tears. As surgical techniques are being developed and refined, rehabilitation protocols for meniscal root repairs must be defined and tested. Little information has been published regarding specific rehabilitation parameters for meniscal root repairs through all phases of rehabilitation. The goal of this commentary is to describe a rehabilitation program for meniscal root repairs that is founded on anatomical, physiological, and biomechanical principles with criteria-based progressions.

Biomechanical consequences of a nonanatomic posterior medial meniscal root repair.

BACKGROUND: Posterior medial meniscal root tears have been reported to extrude with the meniscus becoming adhered posteromedially along the posterior capsule. While anatomic repair has been reported to restore tibiofemoral contact mechanics, it is unknown whether nonanatomic positioning of a meniscal root repair to a posteromedial location would restore the loading profile of the knee joint. PURPOSE/HYPOTHESIS: The purpose of this study was to compare the tibiofemoral contact mechanics of a nonanatomic posterior medial meniscal tear with that of the intact knee or anatomic repair. It was hypothesized that a nonanatomic root repair would not restore the tibiofemoral contact pressures and areas to that of the intact or anatomic repair state. STUDY DESIGN: Controlled laboratory study. METHODS: Tibiofemoral contact mechanics were recorded in 6 male human cadaveric knee specimens (average age, 45.8 years) using pressure sensors. Each knee underwent 5 testing conditions for the posterior medial meniscal root: (1) intact knee; (2) root tear; (3) anatomic transtibial pull-out repair; (4) nonanatomic transtibial pull-out repair, placed 5 mm posteromedially along the edge of the articular cartilage; and (5) root tear concomitant with an ACL tear. Knees were loaded with a 1000-N axial compressive force at 4 flexion angles (0°, 30°, 60°, 90°), and contact area, mean contact pressure, and peak contact pressure were calculated. RESULTS: Contact area was significantly lower after nonanatomic repair than for the intact knee at all flexion angles (mean = 44% reduction) and significantly higher for anatomic versus nonanatomic repair at all flexion angles (mean = 27% increase). At 0° and 90°, and when averaged across flexion angles, the nonanatomic repair significantly increased mean contact pressures in comparison to the intact knee or anatomic repair. When averaged across flexion angles, the peak contact pressures after nonanatomic repair were significantly higher than the intact knee but not the anatomic repair. In contrast, when averaged across all flexion angles, the anatomic repair resulted in a 17% reduction in contact area and corresponding increases in mean and peak contact pressures of 13% and 26%, respectively, compared with the intact knee. CONCLUSION: For most testing conditions, the nonanatomic repair did not restore the contact area or mean contact pressures to that of the intact knee or anatomic repair. However, the anatomic repair produced near-intact contact area and resulted in relatively minimal increases in mean and peak contact pressures compared with the intact knee. CLINICAL RELEVANCE: Results emphasize the importance of ensuring an anatomic posterior medial meniscal root repair by releasing the extruded menisci from adhesions and the posteromedial capsule. Similar caution toward preventing displacement of the meniscal root repair construct should be emphasized.

Meniscal root tears: from basic science to ultimate surgery.

BACKGROUND: In meniscal root tears (MRTs), the disruption of collagen fibers that provide hoop strength results in extrusion of the menisci, altering their biomechanical properties. Clinical diagnosis is difficult, but magnetic resonance imaging usually allows to identify the lesion. Located into the vascularized zone of the meniscus, management is preferentially arthroscopic, aimed at repairing the lesions with arthroscopic transosseous sutures or suture anchors. SOURCES OF DATA: PubMed, Cochrane Library, Google Scholar and Ovid Medline were searched in July 2012 to find literature on MRT tears. We reviewed the literature on biomechanics, imaging features and current treatments of these tears. Twenty-seven appropriate articles were identified and included in the study: 6 biomechanical studies, 11 imaging-based investigations for diagnosis, 1 study on clinical diagnosis and 9 studies about treatment. AREAS OF AGREEMENT: MRTs are infrequent, accounting for 10.1% of all arthroscopic meniscectomies. When the damage occurs to the roots, the transmission of the circumferential hoop tension is impaired and, consequently, the menisci tend to be displaced anteriorly and posteriorly, altering the biomechanics and possibly the kinematics of the knee. AREAS OF CONTROVERSY: Although the importance of the integrity of the meniscal roots is well established, their diagnosis and treatment are still controversial. GROWING POINTS: Biomechanical and clinical studies demonstrate that surgical repair of acute, traumatic meniscal root injuries fully restores the biomechanical features of the menisci, leading to pain relief and functional improvement. The current available surgical techniques for the meniscal root repair (suture anchors and pullout repair) are comparable. Level of evidence IV.