Medial Meniscus Posterior Root Repair Using a Transtibial Technique

Management of Meniscus Pathology with Concomitant Anterior Cruciate Ligament Injury

PURPOSE OF REVIEW

The purpose of this review is to summarize current clinical knowledge on the prevalence and types of meniscus pathology seen with concomitant anterior cruciate ligament (ACL) injury, as well as surgical techniques, clinical outcomes, and rehabilitation following operative management of these pathologies.

RECENT FINDINGS

Meniscus pathology with concomitant ACL injury is relatively common, with reports of meniscus pathology identified in 21-64% of operative ACL injuries. These concomitant injuries have been associated with increased age and body mass index. Lateral meniscus pathology is more common in acute ACL injury, while medial meniscus pathology is more typical in chronic ACL deficiency. Meniscus tear patterns associated with concomitant ACL injury include meniscus root tears, lateral meniscus oblique radial tears of the posterior horn (14%), and ramp lesions of the medial meniscus (8-24%). These meniscal pathologies with concomitant ACL injury are associated with increased rotational laxity and meniscal extrusion. There is a paucity of comparative studies to determine the optimal meniscus repair technique, as well as rehabilitation protocol, depending on specific tear pattern, location, and ACL reconstruction technique. There has been a substantial increase in recent publications demonstrating the importance of meniscus repair at the time of ACL repair or reconstruction to restore knee biomechanics and reduce the risk of progressive osteoarthritic degeneration. Through these studies, there has been a growing understanding of the meniscus tear patterns commonly identified or nearly missed during ACL reconstruction. Surgical management of meniscal pathology with concomitant ACL injury implements the same principles as utilized in the setting of isolated meniscus repair alone: anatomic reduction, biologic preparation and augmentation, and circumferential compression. Advances in repair techniques have demonstrated promising clinical outcomes, and the ability to restore and preserve the meniscus in pathologies previously deemed irreparable. Further research to determine the optimal surgical technique for specific tear patterns, as well as rehabilitation protocols for meniscus pathology with concomitant ACL injury, is warranted.

Prognostic Factors on Preoperative MRI for Patient-Reported Outcomes After Posterior Medial Meniscus Root Repair

Background

Repair of posterior medial meniscus root (PMMR) tears has demonstrated favorable outcomes and may prevent rapid progression of knee osteoarthritis; however, there is a paucity of data regarding prognostic factors affecting postoperative outcomes.

Purpose/Hypothesis

The purpose of this study was to identify factors on preoperative magnetic resonance imaging (MRI) that predict postoperative outcomes after PMMR repair. It was hypothesized that patients with increasing levels of degenerative changes as evaluated through semiquantitative preoperative MRI scans would have worse postoperative patient-reported outcome (PRO) scores.

Study Design

Cohort study; Level of evidence, 3.

Methods

Patients who underwent PMMR repair between 2012 and 2020 and had minimum 2-year follow-up data were enrolled. Pre- and postoperative visual analog scale pain scores and postoperative PRO surveys including the Patient-Reported Outcomes Measurement Information System-Physical Function, Lysholm knee score, and Knee injury and Osteoarthritis Outcome Score (KOOS) were collected. Patients who achieved the Patient Acceptable Symptom State (PASS) on the KOOS subscales were reported. Two fellowship-trained musculoskeletal radiologists reviewed preoperative MRIs and calculated the Whole-Organ Magnetic Resonance Imaging Score for meniscus, cartilage, bone marrow edema-like lesions (BMELL), and meniscal extrusion. Statistical analysis was performed using the 2-sample t test, Mann-Whitney test, and Fisher exact test for categorical variables.

Results

A total of 29 knees in 29 patients were evaluated (22 female, 7 male; mean age at surgery, 52.3 ± 9.9 years; body mass index, 27.6 ± 5.6 kg/m2; mean follow-up, 59.6 ± 26.5 months). Visual analog scale for pain scores decreased significantly from preoperatively (4.9 ± 2.0) to final follow-up (1.6 ± 1.9) (P < .001), and the percentage of patients meeting the PASS ranged from 44.8% for KOOS Sport and Recreation to 72.4% for KOOS Pain and KOOS Quality of Life. Patients with medial tibial BMELL (MT-BMELL) had significantly lower KOOS Symptoms scores (76.1 ± 17.3 vs 88.4 ± 9.7 without MT-BMELL; P = .032). Cartilage quality and presence of meniscal extrusion were not associated with outcomes.

Conclusion

Patients with MT-BMELL on their preoperative MRI in the setting of PMMR tear were found to have worse KOOS Symptoms scores after PMMR repair.

Satisfactory Clinical Outcome, Complications, and Provisional Results of Meniscus Centralization with Medial Meniscus Root Repair for the Extruded Medial Meniscus at Mean 2-Year Follow-Up

PURPOSE

To describe the patient-reported clinical outcomes following medial meniscus root repair with meniscus centralization and to identify common complications and detail provisional results.

METHODS

Patients undergoing medial meniscus root repair with meniscus centralization from 2020 to 2022 were identified using an institutional database. Patients were followed prospectively using postoperative Tegner Activity Scale, visual analog scale (VAS) for pain, Knee Injury and Osteoarthritis Outcome Score, Joint Replacement, International Knee Documentation Committee score, and a Likert score for improvement, surgery satisfaction, and subsequent surgeries at minimum 1-year follow-up with mean 2-year follow-up. Demographics, injury characteristics, and surgical details were also collected.

RESULTS

Twenty-five patients (age: 50 ± 11 years; sex: 76% female; body mass index: 33 ± 8) were included in this study. Postoperative Tegner score was maintained at preoperative levels (P = .233), and VAS at rest, VAS with use, Knee Injury and Osteoarthritis Outcome Score, Joint Replacement, and International Knee Documentation Committee improved significantly postoperatively (P = .003; P < .001, P < .001, P = .023, respectively). Eighty-eight percent of patients reported subjective improvement in their knee at final follow-up. Postoperative radiographs did not show any significant osteoarthritis progression, and no patients had undergone a revision meniscus surgery or total knee arthroplasty at the time of follow-up.

CONCLUSIONS

At minimum 1-year follow-up and mean 2-year follow-up, patients undergoing medial meniscus root repair with meniscus centralization demonstrated significant postoperative improvements in pain, function, and quality of life and reported high rates of surgery satisfaction. There was no evidence of significant arthritic progression on postoperative imaging, and no patients underwent revision meniscus surgery or total knee arthroplasty.

LEVEL OF EVIDENCE

Level IV, case series.

A Convergent Tibial Tunnel Technique for Concomitant Anterior Cruciate Ligament Reconstruction and Meniscal Root Repair

Modern arthroscopic knee-reconstruction techniques involve the use of multiple bone tunnels and fixation devices to restore the anatomy and stability of the knee after traumatic injury. In these injuries, however, tunnel collision can be problematic, especially when combining anterior cruciate ligament reconstruction with meniscal root repairs or multiligament reconstructions. We describe a multiple tibial tunnel technique to allow fixation of both anterior cruciate ligament graft and meniscal roots through convergence to a single tibial cortical aperture.

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.

Clinical and radiologic outcomes in patients with meniscal root tears

BACKGROUND

Meniscal root tears can lead to early knee osteoarthritis and pain. This study aimed (1) to compare clinical and radiological outcomes between patients who underwent arthroscopic meniscal root repair after meniscal root tears and those who received non-surgical treatment, and (2) to identify whether baseline MRI findings could be potential predictors for future treatment strategies.

METHODS

Patients with meniscal root tears were identified from our picture archiving and communication system from 2016 to 2020. Two radiologists reviewed radiographs and MRI studies using Kellgren-Lawrence (KL) grading and a modified Whole Organ MRI Scoring (WORMS) at baseline and follow-up. The median (interquartile range [IQR]) of follow-up radiographs and MRI studies were 134 (44-443) days and 502 (260-1176) days, respectively. MR images were assessed for root tear-related findings. Pain scores using visual analogue scale (VAS) and management strategies (non-surgical vs. arthroscopic root repair) were also collected. Chi-squared tests and independent t-tests were used to assess differences regarding clinical and imaging variables between treatment groups. Logistic regression analyses were performed to evaluate the associations between baseline MRI findings and each future treatment.

RESULTS

Ninety patients were included. VAS pain scores were significantly (p < 0.01) lower after arthroscopic repair compared to conservative treatment (1.27±0.38vs.4±0.52) at the last follow-up visit with median (IQR) of 325 (180-1391) days. Increased meniscal extrusion (mm) was associated with higher odds of receiving non-surgical treatment (OR = 1.65, 95%CI 1.02-2.69, p = 0.04). The odds of having arthroscopic repair increased by 19% for every 1 mm increase in the distance of the tear from the root attachment (OR = 1.19, 95% CI: 1.05-1.36, p < 0.01). The odds of undergoing arthroscopic repair were reduced by 49% for every 1 mm increase in the extent of meniscal extrusion (OR = 0.51, 95% CI: 0.29-0.91, p = 0.02) as observed in the baseline MRI.

CONCLUSIONS

Patients who underwent arthroscopic repair had lower pain scores than patients with conservative treatment in the follow-up. Distance of the torn meniscus to the root attachment and the extent of meniscal extrusion were significant predictors for arthroscopic repair in the next three weeks (time from the baseline MRI to the surgery date).

Benefits of Meniscal Repair in Selected Patients Aged 60 Years and Older

Background

Little is known about the benefits and outcomes of meniscal repair in patients older than 60 years.

Purpose

To (1) report the clinical and radiographic outcomes of meniscal repair in patients aged ≥60 years and compare them with matched patients who underwent meniscectomy and (2) identify procedural failures.

Study Design

Cohort study; Level of evidence, 2.

Methods

We included 32 knees in 32 patients aged ≥60 years (20 female, 12 male; mean age, 64.5 ± 4.6 years) who underwent meniscal repair surgery at a single medical institution between 2010 and 2020. Patients were matched according to age, sex, body mass index, and meniscal tear type with a comparison cohort who underwent meniscectomy (n = 49 patients [49 knees]; 32 female, 17 male). For all patients, demographic information, clinical history, physical examination findings, treatment details, and radiographic images were reviewed and analyzed. At final follow-up (mean, 42.2 months; range, 13-128 months), patients completed the 2000 International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form, Knee injury and Osteoarthritis Outcome Score (KOOS), and Lysholm score. Clinical failure was defined as revision surgery and/or progression to total knee arthroplasty (TKA). A matched-pairs t test was used to analyze differences between the 2 treatment groups, and Kaplan-Meier analysis was used to determine the rates of knee osteoarthritis and progression to TKA.

Results

The majority of patients had a medial meniscal tear (72.8%), whereas the lateral meniscus was torn in 27.2% of cases. Most tears were located in the meniscal root (56.8%), followed by the posterior horn (34.6%) and midbody (8.6%). At final follow-up, all outcome scores were higher in the repair group compared with the meniscectomy group (IKDC, 78.9 ± 13.4 vs 56.0 ± 15.4; KOOS, 86.6 ± 11.9 vs 61.7 ± 16.2; Lysholm, 88.3 ± 13.3 vs 68.7 ± 15.2, respectively; P < .001 for all). Clinical failure was observed in 22% of patients in the repair group.

Conclusion

All clinical outcome scores were higher in the meniscal repair group compared with the matched meniscectomy group at final follow-up. The clinical failure rate of the repair group was 22%. These findings support meniscal repair in selected patients aged ≥60 years.

Meniscal Extrusion: A Critical Analysis Review

➢

Pathologic meniscal extrusion can compromise meniscal function, leading to increased contact forces in the tibiofemoral compartment and the acceleration of osteoarthritic changes.

➢

Extrusion is typically defined as radial displacement of ≥3 mm outside the tibial border and is best diagnosed via magnetic resonance imaging, although ultrasonography has also demonstrated encouraging diagnostic utility.

➢

Surgical management of meniscal extrusion is based on the underlying etiology, the patient's symptom profile, the preexisting health of the articular surface, and the risk of future chondral injury and osteoarthritis.

Comparison of Long-term Radiographic Outcomes and Rate and Time for Conversion to Total Knee Arthroplasty Between Repair and Meniscectomy for Medial Meniscus Posterior Root Tears: A Systematic Review and Meta-analysis

BACKGROUND

Previous meta-analyses have demonstrated superior outcomes in patients undergoing arthroscopic repair of medial meniscus posterior root tears (MMPRTs) compared with meniscectomy. However, these analyses have considered only short- or midterm outcomes and low-quality evidence.

PURPOSE

To compare the mid- to long-term rates of radiographic osteoarthritis (OA) between repair and meniscectomy for MMPRT.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

PubMed, EMBASE, Ovid/MEDLINE, and Cochrane Central Register of Controlled Trials databases were queried for articles evaluating repair and meniscectomy for MMPRT. Articles were eligible if they had a minimum mean 4-year follow-up for radiographic OA or conversion to total knee arthroplasty (TKA) and were at least level 3 evidence. Radiographic OA was assessed using Kellgren-Lawrence (KL) progression. Rates of conversion to TKA and International Knee Documentation Committee (IKDC) scores were also extracted. DerSimonian-Laird binary random-effects models were created to evaluate differences in radiographic OA and TKA conversion rates, with odds ratios (ORs) representing pooled estimates. Continuous random-effects models with standardized mean differences (SMDs) were used to compare postoperative IKDC scores.

RESULTS

Repair and meniscectomy cohorts were followed for a mean of 64.8 months and 62.5 months, respectively, for KL progression; and 82.8 months and 73.8 months, respectively, for TKA rates and IKDC scores. Overall, 59 of 144 (41%) patients undergoing surgical intervention for MMPRT demonstrated OA progression; 18 of 82 (22%) who underwent repair for MMPRT exhibited OA progression compared with 41 of 62 (66%) who underwent meniscectomy (OR, 0.17; 95% CI, 0.03-0.83; P = .029). Overall, 30 of 143 (21%) patients converted to TKA; 9.8% (8/82) of patients who underwent repair converted to TKA (range, 47-131 months), while 36% (22/61) who underwent meniscectomy converted to TKA (range, 17.8-101 months) (OR, 0.15; 95% CI, 0.05-0.44; P < .001). No significant differences between postoperative IKDC scores were observed (SMD, 0.51; 95% CI, -0.02 to 1.05; P = .06).

CONCLUSION

Medial meniscus posterior root repair results in significantly lower rates of radiographic OA progression and conversion to TKA at >60-month follow-up. On the basis of these findings, we recommend consideration of repair of MMPRTs when degenerative changes are not severe, as it can yield improved outcomes.

Current Reviews in Musculoskeletal Medicine: Current Controversies for Treatment of Meniscus Root Tears

PURPOSE OF REVIEW

The role of the meniscus in preserving the biomechanical function of the knee joint has been clearly defined. The hypothesis that meniscus root integrity is a prerequisite for meniscus function is supported by the development of progressive knee osteoarthritis (OA) following meniscus root tears (MRTs) treated either non-operatively or with meniscectomy. Consequently, there has been a resurgence of interest in the diagnosis and treatment of MRTs. This review examines the contemporary literature surrounding the natural history, clinical presentation, evaluation, preferred surgical repair technique and outcomes.

RECENT FINDINGS

Surgeons must have a high index of suspicion in order to diagnose a MRT because of the nonspecific clinical presentation and difficult visualization on imaging. Compared with medial MRTs that commonly occur in middle age/older patients, lateral meniscus root injuries tend to occur in younger males with lower BMIs, less cartilage degeneration, and with concomitant ligament injury. Subchondral insufficiency fractures of the knee have been found to be associated with both MRTs and following arthroscopic procedures. Meniscus root repair has demonstrated good outcomes, and acute injuries with intact cartilage should be repaired. Cartilage degeneration, BMI, and malalignment are important considerations when choosing surgical candidates. Meniscus centralization has emerged as a viable adjunct strategy aimed at correcting meniscus extrusion. Meniscus root repair results in a decreased rate of OA and arthroplasty and is economically advantageous when compared with nonoperative treatment and partial meniscectomy. The transtibial pull-through technique with the addition of centralization for the medial meniscus is associated with encouraging early results.

Optimal Tibial Tunnel Placement for Medial and Lateral Meniscus Root Repair on the Anteromedial Tibia in the Setting of Anterior and Posterior Cruciate Ligament Reconstruction of the Knee

BACKGROUND

Although the risk of tibial tunnel convergence in the setting of multiligamentous reconstruction has been reported in the literature, the risk of tunnel convergence in the setting of posterior cruciate ligament (PCL), anterior cruciate ligament (ACL) reconstruction and medial and lateral meniscus root repair has not been defined.

PURPOSE

To examine the risk of tunnel convergence and to determine optimal tunnel placement for ACL and PCL reconstruction performed in conjunction with posterior medial and lateral meniscus root repairs on the anteromedial proximal tibia.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Three-dimensional (3D) tibial models were created using computed tomography scans of 20 cadaveric specimens. After determining optimal tunnel entry and exit points for ACL and PCL reconstructions, and medial and lateral meniscus root reattachment to the anatomic footprints, we used image processing software to create root tunnels over the anteromedial tibia on the tibial models. ACL and PCL tunnels were kept constant. The meniscus root repair tunnels were then reoriented to match the angle of the ACL tunnel, making both tunnels parallel in the sagittal plane. Tunnel convergence risk was analyzed by identifying the shortest 3D distance between tunnel axes and subtracting the radius of each tunnel from this distance for single- and double-tunnel repair techniques in both case scenarios.

RESULTS

All specimens demonstrated convergence between the ACL and lateral meniscus root tunnels when the root tunnel's entry was created proximal to the ACL tunnel's entry for single- and double-tunnel techniques, but no convergence was seen between these tunnels using the parallel orientation in the sagittal plane. There were no cases of convergence between the ACL and medial meniscus root tunnels in any of the configurations. The greatest distance between the ACL and medial meniscus root tunnels was achieved using the single-tunnel technique in parallel orientation (12.1 ± 2.8 mm). There were no cases of convergence between the PCL and medial meniscus root tunnels in the original orientation; however, 2 of 20 specimens demonstrated convergence using the parallel orientation with the double-tunnel technique, and there were no cases of convergence using the single-tunnel technique. The PCL and lateral meniscus root tunnels did not demonstrate convergence in any configuration.

CONCLUSION

There was a high risk of convergence between ACL and posterior meniscus root tunnels when all the tunnels were created on the anteromedial tibia. Reorienting meniscus root tunnels parallel to ACL tunnels may help reduce this risk. There is increased risk of tunnel convergence with root repairs in cases of bicruciate reconstructions, and therefore a double-tunnel root repair technique should be used with caution.

CLINICAL RELEVANCE

To avoid tibial tunnel convergence when performing ACL and PCL reconstruction with medial and lateral meniscus root repair, surgeons should reorient the meniscus root repair tunnels to be parallel on the sagittal plane to the ACL tunnel to decrease the risk of convergence. In cases of bicruciate ligament reconstruction, use of the double-tunnel technique requires caution to avoid convergence risk with the PCL tunnel.

Prospective Consecutive Clinical Outcomes After Transtibial Root Repair for Posterior Meniscal Root Tears: A Multicenter Study

Background:

Prospective evaluation of clinical outcomes after posterior meniscal root repair utilizing a transtibial pullout technique is limited, and factors that may contribute to outcomes are unclear.

Hypothesis:

It was hypothesized that there would be an overall significant improvement in outcomes after root repair and that differences in clinical outcomes would correlate with age, body mass index (BMI), sex, and meniscal extrusion.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

Consecutive patients undergoing transtibial medial or lateral meniscal root repair were enrolled prospectively at 2 orthopaedic centers between March 2017 and January 2019. Pre- and postoperative magnetic resonance imaging (MRI) were obtained to assess for meniscal healing, quantification of extrusion, articular cartilage grade, and subchondral bone changes. Patient-reported outcomes including International Knee Documentation Committee (IKDC) scores, Tegner activity scale, and visual analog scale (VAS) for pain were collected preoperatively and 2 years postoperatively. Patients were then subdivided by clinical and demographic characteristics to determine factors associated with clinical outcomes.

Results:

Included were 45 patients (29 female, 16 male; mean age, 42.3 ± 12.9 years; mean BMI, 31.6 kg/m²) who underwent 47 meniscal root repairs (29 medial and 16 lateral; 2 had both). Significant improvements at 2-year follow-up were seen in IKDC score (41.1 vs 78.4; P < .001), Tegner activity level (3 vs 4; P < .001), and VAS pain (2.8 vs 0.7; P < .001). BMI, preoperative malalignment, cartilage status, and progressive meniscus extrusion (Δ = 0.7 mm) did not have a negative impact on IKDC and Tegner scores 2 years postoperatively. Age greater than or equal to 50 years and extrusion pre- and postoperatively were associated with decreased Tegner scores. Progressive meniscal extrusion was associated with a decreased overall improvement in Tegner scores.

Conclusion:

Transtibial root repair for medial and lateral posterior meniscal root tears demonstrated significantly improved clinical outcomes at 2 years postoperatively. Increased age, increased BMI, cartilage status, and meniscal extrusion did not have a negative impact on short-term functional outcomes (IKDC), but age greater than or equal to 50 years and extrusion negatively influenced patient activity level (Tegner).

Registration:

NCT03037242 (ClinicalTrials.gov identifier).

Arthroscopic Transtibial Pull-Out Repair for Meniscal Posterior Root Tear: The Slip Knot Technique

A meniscal root tear can increase the tibiofemoral contact pressure to approximate that of total meniscectomy and eventually lead to degenerative change. An anatomic and stable meniscal root repair is essential in restoring the tibiofemoral contact pressure back to that of a normal knee. Suture anchor technique and pull-out suture technique are the 2 main arthroscopic root repair procedures with equivalent success; nonetheless, there remains a lack of an optimal technique with a biomechanical property matching that of the intact root. This article presents a technically simple, fast, and robust pull-out suture construct that incorporates 2 slip-knot locking loops at the meniscus-suture interface. This technique can be used for both medial and lateral posterior root repair, as well as concomitantly with cruciate ligament reconstruction.

Arthroscopic Transtibial Pull-Out Repair for Meniscal Posterior Root Tear: The Slip Knot Technique

A meniscal root tear can increase the tibiofemoral contact pressure to approximate that of total meniscectomy, and eventually lead to degenerative change. An anatomic and stable meniscal root repair is essential in restoring the tibiofemoral contact pressure back to that of a normal knee. Suture anchor technique and pull-out suture technique are the two main arthroscopic root repair procedures with equivalent success; nonetheless, there remains a lack of an optimal technique with a biomechanical property matching that of the intact root. This article presents a technically simple, fast, and robust pull-out suture construct that incorporates two slip-knot locking loops at the meniscus-suture interface. This technique can be utilized for both medial and lateral posterior root repair as well as concomitantly with cruciate ligament reconstruction.

A review of strategies for development of tissue engineered meniscal implants

The meniscus is a key stabilizing tissue of the knee that facilitates proper tracking and movement of the knee joint and absorbs stresses related to physical activity. This review article describes the biology, structure, and functions of the human knee meniscus, common tears and repair approaches, and current research and development approaches using modern methods to fabricate a scaffold or tissue engineered meniscal replacement. Meniscal tears are quite common, often resulting from sports or physical training, though injury can result without specific contact during normal physical activity such as bending or squatting. Meniscal injuries often require surgical intervention to repair, restore basic functionality and relieve pain, and severe damage may warrant reconstruction using allograft transplants or commercial implant devices. Ongoing research is attempting to develop alternative scaffold and tissue engineered devices using modern fabrication techniques including three-dimensional (3D) printing which can fabricate a patient-specific meniscus replacement. An ideal meniscal substitute should have mechanical properties that are close to that of natural human meniscus, and also be easily adapted for surgical procedures and fixation. A better understanding of the organization and structure of the meniscus as well as its potential points of failure will lead to improved design approaches to generate a suitable and functional replacement.

Biomechanical comparison of four tibial fixation techniques for meniscal root sutures in posterior medial meniscus root repair: A porcine study

OBJECTIVE

This study hypothesized that the suture anchor of tibial fixation method of PMMR repair technique is the main factor which reduce the gap formation or over displacement of tear site in initial healing, and then investigated the fixation stability of 4 different tibial fixations through cyclic and ultimate failure load testing of meniscal root sutures.

METHODS

Twenty-four porcine tibiae with intact medial meniscus roots were randomly assigned into 4 groups: transosseous suture, washer, suture anchor, or screw with washer. Each sample underwent cyclic loading followed by a load-to-failure test. Displacement, maximum load to failure, stiffness, and elongation at failure load were recorded.

RESULTS

The maximum average load and displacement at failure for each of the repair groups were as follows: transosseous suture, 232.8 N and 12.16 mm; washer, 189.9 N and 21.5 mm; suture anchor, 140.6 N and 13.8 mm; and screw with washer, 167.9 N and 18.9 mm. The maximum stiffness values for each of the repair groups were as follows: transosseous suture, 19.5 ± 0.7 N/mm; washer, 21.5 ± 1.4 N/mm; suture anchor, 13.8 ± 0.7 N/mm; and screw with washer, 18.9 ± 3.9 N/mm. The mean elongation across the repairs for each of the repair groups after 1000 loading cycles was: transosseous suture, 3.74 ± 0.28 mm; washer, 3.04 ± 0.13 mm; suture anchor, 2.25 ± 0.33 mm; and screw with washer, 2.43 ± 0.19 mm. The mean elongation was significantly less with the suture anchor than with the other techniques (p < .05).

CONCLUSION

Under physiological loading, our results indicate that a slower rehabilitation program with limited flexion and only partial weight bearing is advised when using a suture anchor because of the lower maximum load and stiffness.

THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE

Tibial fixation using a washer or a screw with a washer is an effective and cost-saving technique when an option is required with high stiffness and low displacement at failure.

Surgical Treatment of Meniscal Extrusion: A Biomechanical Study on the Role of the Medial Meniscotibial Ligaments With Early Clinical Validation

Background

Meniscal extrusion refers to meniscal displacement out of the joint space and over the tibial margin, altering knee mechanics and increasing the risk of osteoarthritis. The meniscotibial ligaments have been shown to have an important role in meniscal stability. However, it remains unclear whether an isolated lesion of the medial meniscotibial ligaments will result in meniscal extrusion and whether repairing the detached ligament will reduce extrusion.

Hypothesis

A lesion of the medial meniscotibial ligament will result in meniscal extrusion, and repairing the joint capsule will eliminate the extrusion by returning the meniscus back to its original position.

Study Design

Controlled laboratory study.

Methods

Fresh-frozen human cadaveric knees (N = 6) were used for biomechanical testing. The test protocol involved 100 flexion-extension cycles. In full extension, meniscal extrusion was measured using ultrasound, in both an otherwise unloaded state and while subjected to a 10-N·m varus load. Each knee was tested in its native condition (baseline), after creating a detachment of the medial meniscotibial ligament, and finally with the joint capsule repaired using 3 knotless SutureTak anchors. We also performed a retrospective review of 15 patients who underwent meniscotibial ligament repair with a minimal follow-up of 5 weeks (mean, 14 weeks; range, 5-35 weeks).

Results

During biomechanical testing, the mean absolute meniscal extrusion at baseline was 1.5 ± 0.6 mm. After creation of the meniscotibial ligament lesion, the mean absolute meniscal extrusion was significantly increased (3.4 ± 0.7 mm) (P < .001). After repair, the extrusion was reduced to 2.1 ± 0.4 mm (P < .001). Clinically, a reduction in absolute meniscal extrusion of approximately 48% was reached (1.2 ± 0.6 vs 2.4 ± 0.5 mm preoperatively; P < .001).

Conclusion

This study indicates that the medial meniscotibial ligaments contribute to meniscal stability as lesions cause the meniscus to extrude and that repair of those ligaments can significantly reduce extrusion. Early clinical results using this meniscotibial ligament repair technique support our biomechanical findings, as a significant reduction in meniscal extrusion was achieved.

Clinical Relevance

Our biomechanical findings suggest that repair of medial meniscotibial ligaments reduces meniscal extrusion and clinically may improve meniscal function, with the possible long-term benefit of reducing the risk for osteoarthritis.

Meniscal Root Injuries

Meniscal root tears are an increasingly recognized injury leading to notable functional limitations, potential rapid cartilage deterioration of the affected compartment, and subsequent risk of total knee arthroplasty if left untreated. Repair of these tears is advised when articular cartilage remains intact because both medial and lateral meniscus root repairs have demonstrated favorable results. Recent literature demonstrates decreased rates of osteoarthritis and arthroplasty after medial meniscus root repair compared with partial meniscectomy and nonsurgical management. The transtibial pull-out repair technique is most commonly used and provides a biomechanically strong suture construct with standard and familiar knee arthroscopy portals. Furthermore, repair has recently been shown to be economically effective by decreasing overall societal healthcare costs when compared with more conservative management strategies. This review outlines the evaluation, treatment, and documented outcomes of meniscal root repair, which is imperative to the preservation of knee function and maintaining quality of life.

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.

Initial Biomechanical Properties of Transtibial Meniscal Root Repair are Improved By Using a Knotless Anchor as a Post-Insertion Tensioning Device

The importance of meniscal root integrity to preserve contact load distribution and stability at the knee joint is recognised. Transosseous suture technique is commonly used to repair meniscal root tears. However, clinical results are not completely satisfactory. Specifically, concern exists about the development of substantial displacements at the repaired root. This study aims to assess if the use of a post-insertion tensioning knotless-anchor at the distal exit of the tibial tunnel improves time-zero biomechanical properties of the transtibial repair compared to knotting sutures over a cortical button. Twenty porcine tibia with detached posterior medial meniscal roots were randomized into two groups depending on the method to fix the sutures after root repair: knotless-anchor (KA) or suture-button (SB). Specimens underwent cyclic and load-to-failure testing. Group KA showed significantly smaller residual root displacements after low-level repetitive loads. At the load-to-failure test, Group KA exhibited significantly lower displacements at representative subcritical loads and higher resistance to development of clinically relevant displacements. The authors conclude that use of a knotless suture anchor attached at the distal outlet of the bone tunnel may be an effective solution to reduce root displacements in transtibial meniscal root repairs, a matter reported to alter biomechanics of joint contact.

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.

Arthroscopic Repair of Double Radial Tears of the Lateral Meniscus

Double radial tears of the lateral meniscus are rare injuries that typically occur in the setting of an acute anterior cruciate ligament rupture. Full-thickness radial tears of the meniscus body and root render the meniscus nonfunctional from a loss of hoop stress resistance. Repair of these tears can normalize contact pressures in the lateral compartment and delay arthritic changes. We describe our technique for repairing a lateral meniscus body radial tear and concomitant posterior root tear, via inside-out suture repair and transtibial suture repair, respectively. This investigation was performed at Mayo Clinic.

Preoperative MRI for the Multiligament Knee Injury: What the Surgeon Needs to Know

The multiligament knee injury is devastating and potentially limb threatening. Preoperative magnetic resonance imaging for the evaluation of the multiligament knee injury is an invaluable clinical tool, and when the radiologist is familiar with how certain injury patterns influence management, optimal outcomes can be achieved. We provide a detailed description of the relationship between salient imaging features of the multiligament knee injury, focusing on the preoperative magnetic resonance imaging, and their influence on clinical decision-making.

A technique combining "U" shape suture and shared tunneling to treat the posterior cruciate ligament rupture and posterior root tears of the medial meniscus

BACKGROUND

The standard treatment of the posterior cruciate ligament (PCL) rupture accompanied with the posterior root of medial meniscus (PRMM) tears is controversial. Our research describes a minimally invasive technique for the PCL rupture accompanied with the PRMM tears.

METHODS

We described a "U" shape suture and shared tunneling technique to treat the PCL rupture accompanied with PRMM tears. Three patients (ages 28, 42, and 59 years old) who underwent this surgery have been followed up for more than 1 year at most. The MRI was done, and the hospital for special surgery (HSS) score was adopted to evaluate the clinical effect. Firstly, we built both femoral and tibial bone tunnels for the PCL reconstruction. Secondly, we used the suture hook to pass the suture line through the PRMM. Thirdly, we passed the prepared tendon through the bone tunnel and fixed the prepared tendon by an endobutton plate and an interference screw (Smith & Nephew) respectively on the side of the femur and tibia. At last, we used an endobutton plate (Smith & Nephew) outside the tibial bone tunnel to fix the PRMM.

RESULTS

These three patients did not show any complications. At 1 year after the operation, we found good knee stability, negative posterior drawer test, and normal range of motion compared with the contralateral knee joint. The MRI also showed a good union of the PRMM and PCL. The hospital for special surgery (HSS) score was 90 points.

CONCLUSIONS

With an ideal therapeutic effect, this technique is worthy to be promoted for patients with the PCL rupture and PRMM tears.

High Rate of Missed Lateral Meniscus Posterior Root Tears on Preoperative Magnetic Resonance Imaging

Background:

Lateral meniscus posterior root tears (LMPRTs), if left untreated, can cause devastating effects to the knee, with rapid articular cartilage degeneration and loss of the meniscus as a secondary stabilizer. Detection and surgical repair of these defects have been linked to favorable outcomes, but preoperative identification of LMPRTs continues to be challenging.

Purpose:

To determine the rate of LMPRTs diagnosed preoperatively on magnetic resonance imaging (MRI) in a consecutive series of arthroscopically confirmed LMPRTs.

Study Design:

Case series; Level of evidence, 4.

Methods:

A retrospective cohort of 45 consecutive patients with arthroscopically confirmed LMPRTs between 2010 and 2017 were included in this study. The preoperative MRI report for each patient was evaluated and compared with intraoperative findings. Each preoperative MRI study was then reviewed by 2 fellowship-trained musculoskeletal radiologists who worked in consensus.

Results:

A total of 45 patients (32 males, 13 females) with arthroscopically confirmed LMPRTs and a mean age of 27 years (range, 14-54 years) were included in the study. Only 15 of 45 LMPRTs (33%) were initially diagnosed on preoperative MRI. Past or concurrent anterior cruciate ligament (ACL) reconstruction was present in 37 of 45 cases (82%). Upon retrospective review, 15 of the 30 missed LMPRTs were “clearly evident,” 12 “subtly evident,” and 3 “occult” (unavoidably missed). There were no significant differences in the rate of LMPRT diagnosis based on history of prior knee surgery, meniscus extrusion, or tearing of the meniscofemoral ligament.

Conclusion:

Despite improved identification of other meniscus tear patterns on MRI, a high percentage of LMPRTs were still missed. In the setting of previous ACL reconstruction, if the root cannot be confidently identified, the MRI interpretation should indicate that “the root is poorly visualized” to alert the surgeon to thoroughly evaluate this structure. The surgeon should maintain a high index of suspicion and carefully probe the posterior root of the lateral meniscus at the time of arthroscopy, especially in cases of ACL injury.