Second look arthroscopic evaluation of repaired radial/oblique tears of the midbody of the lateral meniscus in stable knees

Clinical outcomes of repaired radial meniscal tears: A retrospective study with minimum 2-year follow-up

BACKGROUND

The management of meniscal radial tears has changed significantly in recent years in favor of meniscus repair. However, there is still limited published data on the outcomes and risk factors associated with repair failure. The objective of this study is to evaluate the clinical success rate of repaired meniscal radial tears and identify potential risk factors for failure.

METHODS

Patients who underwent repair of meniscal radial tears between 2016 and 2022 were reviewed retrospectively. The following parameters were collected: demographic data, pre-operative Kellgren-Lawrence grading, history of previous knee surgeries, time from injury to surgery, injury location, number of sutures used, use of transtibial tunnel augmentation, associated procedures, postoperative functional scores, and clinical failure rates.

RESULTS

81 patients were included, with a mean age of 29.9 ± 12.3 years. The mean follow-up time was 36.7 ± 17.0 months. Postoperatively, the mean IKDC was 81 ± 18.1, and the mean Lysholm score was 82 ± 18.4. The clinical failure rate was 19.8%. In the univariate analysis, the factors associated with failure included increased age, female gender, medial meniscus repair, isolated repairs (without ACL reconstruction), a Kellgren-Lawrence scale greater than 0, and repairs without a transtibial tunnel. However, none of these variables were statistically significant in the multivariate analysis adjusted for age and gender.

CONCLUSION

The clinical success rate of repaired meniscal radial tears was about 80% after a minimum 2-year follow-up. Increased age, female gender, repair of medial meniscus, isolated repair without ACL reconstruction, mild preoperative osteoarthritic signs, and repair without a transtibial tunnel augmentation are possible risk factors for failure.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Bone marrow lesion and medial meniscus extrusion width changes following arthroscopic partial meniscectomy for medial meniscal flap tears

BACKGROUND

The current literature evaluating meniscectomy outcomes often mixes various tear patterns, failing to elucidate the impact of specific tear types on procedure results. Flap tears, which are prone to causing mechanical symptoms, require targeted research. This study aims to examine Lysholm scores following a meniscectomy for medial meniscus flap tears, to determine if extensive resections lead to poorer one-year outcomes, and to assess their impact on postoperative bone marrow lesion (BML) risk and medial meniscus extrusion (MME) width.

METHODS

Patients undergoing arthroscopic meniscectomy for medial meniscal flap tears were classified into three groups: minimum resection, single leaf resection, and subtotal resection. Lysholm scores and medial joint space (MJS) width on Rosenberg view radiographs were measured preoperatively and one year postoperatively. BMLs and MMEs were assessed via MRI preoperatively and at 1, 3, 6, and 12 months postoperatively.

RESULTS

Fifty patients (mean age 60 ± 13 years) underwent meniscectomy: minimum resection in 21 (42%), single leaf in 23 (46%), and subtotal in 6 (12%). The Lysholm scores improved significantly, from 65.5 ± 17.6 to 93.4 ± 16.5 (n = 50) at 12 months in patients overall (p < 0.001), while MJS width decreased from 3.9 ± 0.7 mm to 3.5 ± 0.8 mm (p < 0.001). There were no significant differences in Lysholm scores or MJS widths among the three resection patterns. The occurrence rate of BMLs in the medial femoral condyle and tibial plateau increased post-surgery, peaking at 1 month, but then improved to near-baseline by 12 months. The occurrence rate of BMLs was higher in the single leaf and subtotal meniscectomy groups post-surgery, but declined across all groups by 12 months. Among the three groups with different resection patterns, MME width at 12 months was 2.7 ± 1.8 mm in the subtotal resection group, which was significantly larger than in the other groups.

CONCLUSIONS

Arthroscopic partial meniscectomy for flap tears yielded favorable 12-month outcomes. Larger resections were associated with greater BML incidence and greater MME width.

Rapid Chondrolysis After Lateral Meniscal Repair and Anterior Cruciate Ligament Reconstruction Combined With Segond Fracture Fragment Fixation: A Case Report

We present a case of rapid chondrolysis after the repair of a lateral meniscus (LM) radial tear. An 18-year-old male competitive skier sustained an anterior cruciate ligament (ACL) injury associated with a Segond fracture and LM radial tear in the posterior segment. The patient underwent a two-stage surgery, LM repair and internal fixation of the fracture fragment, followed by ACL reconstruction. Although the postoperative course was uneventful, the patient experienced persistent joint effusion after starting ski practice six months postoperatively. An arthroscopic examination was performed one year after ACL reconstruction, and severe cartilage damage was observed in the lateral femoral condyle and tibial plateau, whereas complete healing of the repaired LM was observed. Despite complete arthroscopic healing of the meniscus, meniscal function may not be fully restored by isolated meniscal repair of radial tears associated with ACL injury. The development of new surgical methods may be necessary to improve functional restoration.

Radial Tear of the Midbody in Complete Discoid Lateral Meniscus: A Case Report

To the best of our knowledge, there are no reports on the results of the repair of radial tears of the midbody of the complete discoid lateral meniscus (DLM). A 14-year-old female underwent meniscal replacement with autologous tendon transplantation for early re-tear after repair of the radial tear in the midbody of complete DLM. Two years after the tendon transplantation, there was no effusion or swelling, and the patient was able to exercise completely without symptoms. Repair without saucerization did not allow the placement of multiple sutures at the periphery and allowed destructive forces from the lateral femoral condyle to impact the tear site. Therefore, meniscectomy of the medial zone might be necessary to repair the radial tear of the midbody of complete DLM. Further follow-up is needed to conclude whether the tendon graft can replace the meniscus in the long term.

All-Inside Arthroscopic Tie-Grip Suture Repair for Radial Tear in the Midbody of Lateral Meniscus Using an All-Inside Device and Slotted Cannula

Inside-out repair of meniscal tears is the gold standard surgical approach; however, its use is limited by the need for a posterior incision and neurovascular risk. In this Technical Report, we present details of the all-inside arthroscopic tie-grip approach for repairing a radial tear of the midbody of the lateral meniscus using an all-inside device (TRUESPAN) and a slotted cannula. In contrast to the inside-out approach, this technique helps reduce surgical invasiveness and provides stable fixation as the vertical mattress sutures bundle the circumferential fibers and act as rip stops for the horizontal sutures. However, the operating surgeon must understand proper insertion techniques to successfully use the devices required for this procedure.

Modified Centralization Technique of Tibial Side Capsulodesis for Radial Tear of Incomplete Discoid Lateral Meniscus

An incomplete discoid lateral meniscus is often associated with radial tears, which cause meniscal extrusion and result in poor healing outcomes. Centralization has recently been used as a surgical method to reduce extrusion. However, various repair techniques use single point of fixation sutures exclusively on the femoral side, potentially hindering healing. In this study, a method is devised in which 2 anchor sutures are placed on the tibia and guided out of the capsule from the tibial side of the meniscus, and another anchor is placed distally to tighten the meniscotibial ligament in a plane. This method supports the repaired site against hoop stress by tightening the meniscotibial ligament and is considered a physiological repair because the sutures are confirmed to the tibial side of the meniscus rather than on the femoral side. Furthermore, an inside-out suture of the torn area with a fibrin clot derived from the bone marrow aspirate, rich in tissue-healing components, is also performed.

Significantly smaller lateral extrusion was observed within 24 weeks after all-inside suture repairs of radial tear in the middle segment of lateral meniscus compared to inside-out repairs

Purpose

To evaluate the postoperative meniscal extrusion between all-inside suture (AIS) and trans-capsular suture (TCS) repair techniques.

Methods

Thirteen patients (mean age, 19.4 years) underwent AIS repairs using only sutures (AIS group) for radial tears in the middle segment of the lateral meniscus (RTMLM), and seven patients (mean age, 20.3 years) underwent inside-out repairs among TCS (TCS group). For all cases, lateral (LE), anterior (AE) and posterior (PE) meniscal extrusions of the lateral meniscus were measured during preoperative and 3-, 12- and 24-week postoperative MRIs. Then, the change of each extrusion from preoperative to each postoperative period was calculated as ∆LE, ∆AE and ∆PE.

Results

There was no significant difference between the AIS and TCS groups in the preoperative extrusions. As for postoperative extrusions, only ∆LEs in the AIS group was significantly smaller than those in the TCS group at all postoperative periods (-1.5 ± 1.7 vs. 0.9 ± 0.7 mm at 3-week, -0.9 ± 0.9 vs. 0.4 ± 0.9 mm at 12-week and -0.3 ± 1.0 vs. 0.6 ± 1.1 mm at 24-week postoperation). In ∆AEs and ∆PEs, at all three postoperative periods, there were no significant differences.

Conclusion

Postoperative LE, AE and PE on MRIs after AIS and TCS repairs for RTMLM were investigated. Significantly smaller lateral extrusion was observed within 24 weeks after AIS repairs of RTMLM compared to TCS repairs, which could lead to stabilization of the repair site and prevent degenerative changes.

Level of Evidence

Case-control study, retrospective comparative study, Level Ⅲ.

Treatment of chronic and complex meniscal tears with arthroscopic meniscus repair augmented with collagen matrix wrapping: failure rate and functional outcomes

PURPOSE

Meniscal wrapping is a fully arthroscopic technique that involves enhanced meniscal repair with a tissue-engineered collagen matrix wrapping. This study aims to investigate the feasibility of using the meniscal wrapping technique for the treatment of chronic or complex meniscal tears. The primary objective is to assess its failure rate. The secondary objectives are to analyse complication rate, functional outcomes and overall patient satisfaction.

METHODS

This retrospective case series study included patients who sustained chronic and complex tears undergoing meniscal wrapping with autologous liquid bone marrow injection. Failure rate was considered if the patient underwent partial or complete meniscectomy or knee replacement during the follow-up, while other unexpected knee reoperations were considered as complications. Clinical outcomes were evaluated through the IKDC score, Tegner Activity Score and Short Assessment of Patient Satisfaction.

RESULTS

Twenty-one patients were included (15 non-acute bucket-handle tears, three non-acute horizontal tears and three non-acute complex injuries). The failure rate was 9.5% at 33 months. The rate of other unplanned reoperations was 14.3%, but none of these complications were apparently directly related to the wrapping technique. The average postoperative IKDC was 73.3/100. No statistically significant difference was encountered between preinjury and postoperative Tegner Activity Score. The mean overall patient satisfaction was 88.3/100.

CONCLUSIONS

Meniscal wrapping can be safely used as an adjunctive technique to meniscal repair in such difficult-to-treat cases to preserve the meniscus. The technique achieves a low failure rate and promising results of knee function, and patient satisfaction.

Meniscal Radial Tears Repaired With All-Inside and Inside-Out Techniques Result in Improved Clinical Outcome Scores, but Inside-Out Repairs May Be Associated With Higher Failure Rates Clinically and on Second-Look Arthroscopy: A Systematic Review

PURPOSE

To compare patient-reported outcomes (PROs), failure, and healing rates after all-inside (AI) repair versus inside-out (IO) repair for the treatment of meniscal radial tears.

METHODS

A literature search was performed according to the 2020 Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines using the Scopus, PubMed, and Embase computerized databases. Level of Evidence I through IV human clinical studies evaluating PROs and/or the incidence of failure and healing after AI versus IO repairs for meniscal radial tears were included. Clinical failure was defined by the presence of joint-line tenderness; a positive McMurray test; and mechanical symptoms, such as locking, catching, or giving way. Study quality was assessed using the Methodological Index for Non-Randomized Studies criteria and the Modified Coleman Methodology Score.

RESULTS

Ten studies published from 2008 to 2023 comprising 205 patients were identified, including 142 patients who underwent AI repair and 63 patients who underwent IO repair for radial meniscus tears. Postoperative Lysholm and Tegner scores ranged from 90.8 to 95.6 and 5.7 to 8.2, respectively, in the AI repair group, compared with 86.9 to 94.2 and 6 to 7.5, respectively, in the IO repair group. All patients exceeded published values for minimal clinically important difference for the Lysholm score. Clinical failure ranged from 0% to 40% in the AI group and 0% to 62.5% in the IO group. Healing assessments on second-look arthroscopy revealed failure rates ranging from 0% to 13.3% in the AI group and 0% to 39% in the IO group. Complete and partial healing ranged from 28.6% to 92.3% in the AI group and from 25% to 70% in the IO group. Chondral damage on second-look arthroscopy ranged from 0% to 95% in the IO group and 0% to 57.7% in the AI group. Postoperative complications ranged from 0% to 2% within the AI group, whereas no complications were reported in the IO group. No implant-related complications were reported in any study group.

CONCLUSIONS

Both all-inside and inside-out repairs for meniscal radial tears demonstrated improved PROs; however, current literature suggests that the IO technique may have higher failure rates both clinically and on second-look arthroscopy.

LEVEL OF EVIDENCE

Level IV, systematic review of Level III and IV studies.

Usefulness of Probing Sensor Device for Evaluating Meniscal Suture and Scaffold Implantation

Appropriate suture tension is a key factor in successful meniscal repair. This study aimed to clarify the appropriate value of meniscal stabilization with suture repair based on a probing procedure for healthy porcine menisci and a novel meniscal scaffold. After evaluating the reliability of the probing sensor, meniscal vertical tear and partial meniscectomy models were developed, in which suture repair and meniscal scaffold implantation were performed at suture intervals ranging between 20 and 2.5 mm. The residence forces at each interval were evaluated using a probing sensor. Moreover, a tensile test was conducted to evaluate the displacement and presence or absence of gaps. We found that normal and meniscal scaffolds should be fixed within 5 mm of suture interval. The probing residence forces required were at least 1.0 N for vertical tears and 3.0 N for meniscal scaffolds. These findings may be taken into consideration to reduce suture failure following meniscal tear repair and stabilizing meniscal scaffold fixation.

Lateral meniscal injury without medial meniscal injury indicates the existence of the Segond fracture in ACL-deficient knees

Background/Objective

The purpose of this study was to find factors indicating the occurrence of the Segond fracture, a specific type of anterolateral ligament injury.

Methods

From January 2015 to December 2017, we retrospectively reviewed the medical records of patients diagnosed with acute anterior cruciate ligament (ACL) injury who underwent reconstruction within 90 days of injury. Diagnosis of the Segond fracture was determined either by magnetic resonance imaging or plain radiographs. Factors examined were: age at surgery, sex, body mass index (kg/m2), status of menisci, and activities led to ACL injury. After univariate screening, multivariate logistic regression analyses were performed. Patients were divided into four groups based on the presence of lateral meniscal (LM) and/or medial meniscal (MM) injuries and compared with respect to the occurrence of Segond fractures.

Results

A total of 375 patients were included (163 males, 212 females), with mean age 25.8 years old. Among them, 22 of 375 (5.9 %) had a Segond fracture. We identified injured lateral menisci (adjusted odds ratio (aOR), 3.029; 95 % Confidence Interval (CI), 1.206-7.609; P = 0.018), intact medial menisci (aOR, 0.229; 95 % CI, 0.065-0.810; P = 0.022), and higher body mass index (aOR, 1.102; 95 % CI, 1.008-1.205; P = 0.034) as factors indicative of the occurrence of Segond fracture. LM injury without MM injury suggested the existence of a Segond fracture.

Conclusion

LM injury without a MM injury indicated the occurrence of a Segond fracture. Higher body mass index also increased the risk for Segond fracture occurrence.

Isolated radial tears of the lateral meniscus midbody: a case series of professional athletes treated with outside-in repair

PURPOSE

The main aim of the study is to assess clinical and functional outcomes of arthroscopic outside-in repair of isolated radial tears of the midbody of lateral meniscus in professional athletes and to evaluate the return to the sport activity after surgery.

METHODS

A retrospective data collection on professional athletes with isolated complete lesion of the midbody of lateral meniscus, treated with arthroscopic outside-in repair was carried out. Outcome measures included functional assessment, Limb Symmetry Index (LSI) and Hamstring Quadriceps Ratio (HQR) and Lysholm score collected before surgery and at 4-month follow-up. Data on return to sport practice and re-injury were also retrieved.

RESULTS

Fourteen patients satisfied the selection criteria. Full return to professional sport activity (Tegner 10) was registered in the 86% of the cohort at 4 months after the surgery. Functional testing of the athletes showed a return of the LSI and HQR to the pre-surgical condition, demonstrating a full recovery of the functional ability and muscle strength. Similarly, clinical evaluation through Lysholm score showed an improvement, reaching an average of 97.7 points at 4 months follow-up.

CONCLUSION

A good functional recovery and a high rate of return to play has been observed in a population of professional athletes, at 4 months after outside-in repair.

Clinical outcomes after repair of an isolated radial tear in the middle segment of the lateral meniscus - All-inside suture repair vs trans-capsular suture repair

Background/objective

For radial tears, all-inside suture (AIS) repair was clearly biomechanically superior, compared to conventional trans-capsular suture (TCS) repairs. However, clinical comparative studies of these two repairs techniques have not to be performed. Therefore, the aim of this study was to compare the clinical outcomes after AIS repair and TCS repairs for isolated radial tear at middle segment of lateral meniscus (RTMLM) in stable knees of young athletes.

Methods

Twenty-six athletes (mean age, 19.1 years) underwent AIS repair with the double horizontal suture technique, using SutureLasso™ (Arthrex, Naples, FL) for isolated RTMLM (AIS group), and 20 athletes (mean age, 19.0 years) underwent inside-out repair, one of TCS repairs, with tie-grip suture technique (TCS group). All athletes were assessed for preoperative and two-year postoperative Knee injury and Osteoarthritis Outcome Score (KOOS). At six-month after repair, the lateral meniscal extrusion on mid-coronal plane on MRI and healing status on second-look arthroscopy were also evaluated in all patients.

Results

In both groups, KOOS improved to either good or excellent postoperatively, while complete healing was found in only 23 and 25% at second-look arthroscopy. We identified no group-dependent differences in KOOS or healing status on arthroscopy. However, a close examination of failure rates revealed significant lower rates in AIS group relative to that of TCS group (p = 0.048). Moreover, the change from preoperative to postoperative lateral meniscal extrusion in AIS group was significantly smaller than that in TCS group (p = 0.038).

Conclusions

AIS and TCS repairs for RTMLM were comparable in providing satisfactory clinical results with low rates of complete healing on arthroscopy. However, AIS repair could have lower failure rate of healing on arthroscopy and minimize postoperative lateral meniscal extrusion more effectively than TCS repair on MRI.

Improved Outcomes After Reinforced Radial Meniscus Repair Augmented With Bone Marrow Aspirate Concentrate

Purpose

To assess clinical outcomes of patients who have undergone surgical repair of radial meniscal tears with reinforced suture bar (rebar) technique augmented with bone marrow aspirate concentrate.

Methods

This is a retrospective study of a single fellowship-trained sports medicine surgeon's experience on all patients who underwent a reinforced repair (rebar) of a radial meniscus tear from November 2016 to 2018, with a minimum of 12-month follow-up. Lysholm scores, IKDC (International Knee Documentation Committee) Subjective Knee Form scores, and Tegner scale were collected postoperatively at periods for at least 1 year and retrospectively studied.

Results

Patients were followed for an average of 36.3 ± 25.0 months [range: 12.0-69.0 months]. Pain scores improved from 6.1 ± 2.1 to 0.4 ± 1.4 at 1 year (P < .001). IKDC Subjective Knee Form scores improved from 63 ± 26 to 90 ± 13 (P = .021). Lysholm scores improved from 64 ± 28 to 94 ± 9 (P = .025). Based on a calculated minimal clinical important difference (MCID) of 1.5, 100% of patients had improvement above the MCID. In addition, 88% of patients had a 1-year IKDC Subjective Knee Form score above the patient acceptable symptomatic state. Preoperative Tegner activity scale improved from 3 ± 1.5 to 8 ± 2.6 (P = .007). Patients returned to their preinjury activity with little difference in the Tegner activity scale when we compared preinjury and 1-year postoperative (8.1 ± 1.3 vs 8.0 ± 2.6 respectively, P = .317).

Conclusions

The rebar repair technique for radial meniscus tears, with bone marrow aspirate concentrate augmentation, showed improved outcomes in both pain and function at minimum follow-up of 12 months. Patients were able to return to a high preinjury activity level by 1 year, and 100% of patients had improvement above the MCID and 88% met patient acceptable symptomatic state.

Level of Evidence

Level IV, therapeutic case series.

Several Techniques Exist With Favorable Biomechanical Outcomes in Radial Meniscus Tear Repair-A Systematic Review

PURPOSE

To compare biomechanical properties of various radial tear repair techniques in the medial and lateral menisci.

METHODS

A search was performed for key words regarding mechanical properties of repair of radial meniscal tears in PubMed, Embase, CINAHL, Scopus, and Cochrane databases, yielding 1791 articles. Articles were screened using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines against inclusion criteria and underwent Methodological Index for Non-Randomized Studies (MINORS) methodologic quality assessment. Repair constructs evaluated were classified based on repair technique, use of a transtibial augmentation, and the number, orientation, and pattern of stitches. Results published across different studies were compared but not subjected to meta-analysis due to variability in testing procedures and heterogeneity of repair methods.

RESULTS

We identified 20 studies that performed mechanical testing on 21 different radial meniscal tear repair techniques. The greatest reported mean load-to-failure (LtF) were the transtibial 2-tunnel + 4 horizontal inside-out sutures (191.2 N ± 17.3, cadaver) and all-inside double vertical repair (146.3 N ± 36.2, porcine). The transtibial technique improved LtF and displacement of an inside-out (IO) horizontal repair. All-inside vertical repairs demonstrated greater LtF, stiffness, and displacement compared with IO horizontal repairs in 2 studies. Compared with IO double horizontal repairs, all-inside double vertical or IO double horizontal repairs with reinforcing stitches parallel to the tear exhibited greater LtF in 3 studies and stiffness in 2 studies. Two studies reported that parallel reinforcing stitches significantly reduced suture tear-through compared with similar, nonreinforced repairs. Mean MINORS score for all studies analyzed was 19.88 ± 1.47 points.

CONCLUSIONS

A systematic review demonstrated that there may be alternatives to traditional IO horizontal repairs for radial meniscus tears. Less-invasive all-inside vertical techniques reinforced with suture parallel to the tear instead of standard IO horizontal sutures may improve strength of repair. In addition, transtibial 2-tunnel augmentation may also increase strength of radial meniscus tear repairs.

CLINICAL RELEVANCE

There may be alternatives to IO horizontal repairs for radial meniscus tears.

Second-look arthroscopy after meniscus repair and synovial mesenchymal stem cell transplantation to treat degenerative flaps and radial tears of the medial meniscus: A case report

BACKGROUND

The purpose of this study was to compare arthroscopic findings of a degenerative flap and radial tear of the medial meniscus (MM) before and one year after treatment by meniscus repair and synovial mesenchymal stem cell (MSC) transplantation.

METHODS

Patients with a degenerative flap and radial MM tear that would generally be treated by meniscectomy were included. The patients ranged in age from 45 to 62 years and all underwent meniscus repair and synovium harvest at time 0. The digested synovium was cultured with autologous serum for 12 days, and an average of 4 × 10⁷ MSCs were transplanted at two weeks. A second-look arthroscopy was performed at 52 weeks (n = 6). The average duration of symptoms was 24 months. For flap tears, arthroscopic findings were quantified in terms of the presence, stability, and smoothness of the meniscus at each zone and area. The Lysholm score was evaluated throughout the 52 week follow-up.

RESULTS

Four patients with MM flap tears showed deficiencies in the central area at the posterior junctional zone before treatment, but this zone was completely restored to a stable and smooth condition in two patients and partially restored in the other two patients. The arthroscopy score for a flap tear at the central area of the posterior junctional zone was 0.3 ± 0.5 before treatment and 4.3 ± 2.1 after treatment. The score was significantly higher after treatment (p < 0.05, n = 4). The original radial MM tears in two patients were healed one year after treatment. Lysholm scores were significantly higher at 4 and 52 weeks after treatment than before treatment (n = 6).

CONCLUSIONS

Arthroscopic findings for a degenerative flap and radial tear of the MM were improved at the central area of the posterior junctional zone one year after meniscus repair and MSC transplantation.

Two Uncommon Complications Related to Suture Knots After Meniscal All-Inside Suture Repair: A Case Report

CASE

A 17-year-old male patient suffered a radial lateral meniscus tear and underwent an arthroscopic all-inside suture repair. After 7 months, the patient experienced catching. Magnetic resonance imaging and computed tomography revealed an intra-articular loose body without calcification, which was removed surgically. The excised specimen was histopathologically confirmed to be a necrotic meniscus fragment with a suture knot. In addition, cartilage damage because of suspected impingement by a residual suture knot was observed. After removing the loose body and knot, the patient's symptoms were relieved, and he returned to sports.

CONCLUSION

Suture knot-related complications should be considered while performing meniscal repairs.

Editorial Commentary: All-Inside Double-Vertical Cross-Suture is an Effective Technique for Knee Meniscus Radial Tear Repair, but There is No Gold-Standard Evaluation Tool for Evaluating Healing and Function of the Repaired Meniscus

Treatment of radial tears of the lateral meniscus is challenging. Previous studies after repairing radial tears showed low healing rates. Various suture techniques are now being developed, and biomechanical and clinical studies using these new techniques are underway. Amid development, the all-inside double vertical cross-suture technique seemed to be effective. However, limited evaluations after meniscal repair might not fully reveal whether the repaired meniscus can maintain its function. Because the best single method that can completely evaluate meniscal healing and its function after repair is still lacking, we should introduce various assessments and consider them in a comprehensive way.

Biochemical Characteristics and Clinical Result of Bone Marrow-Derived Fibrin Clot for Repair of Isolated Meniscal Injury in the Avascular Zone

PURPOSE

To characterize bone marrow aspirate-derived fibrin clot (BMA clot) and evaluate the clinical result of meniscal repair with a BMA clot for isolated meniscal injury in the avascular zone.

METHODS

Blood counts of total leukocytes, platelets, and concentrations of basic fibroblast growth factor (bFGF), transforming growth factor β (TGF-β), and stromal cell-derived factor 1 (SDF-1) were analyzed with BMA, peripheral blood (PB), BMA clot, and PB clot from 5 patients treated for meniscal repair. In addition, a retrospective analysis of 30 patients with isolated avascular meniscal injuries who underwent repair with a BMA clot was performed to assess rate failure. Avascular meniscal injury was identified as horizontal tear, radial tear, and flap tear. Clinical failure was defined as the presence of 1 or more of Barrett's criteria. Anatomic failure was defined as the existence of equivalent signal intensity to intra-articular fluid along the repair area on follow-up magnetic resonance imaging (MRI). Patients' demographic and clinical data were compared between the overall failure group and the success group.

RESULTS

The bFGF, TGF-β, and SDF-1 levels of BMA clots were more highly concentrated compared with PB clots. The Lysholm scores and meniscal status evaluated by MRI were significantly improved from preoperatively to postoperatively (both P < .001). The Kellgren-Lawrence grading of knee radiographs did not significantly differ pre- and postoperatively (P = .140). Rates of clinical failure, anatomic failure, and retear were 10%, 6.7%, and 3.3%, respectively. The demographic characteristics and surgical and postoperative status did not significantly differ between the overall failure group and the success group.

CONCLUSIONS

BMA clots had increased levels of cytokines compared to PB clots. The retrospective analysis revealed that the rates of clinical failure and anatomic failure after meniscal repair with a BMA clot for isolated avascular meniscal injury were 10% and 6.7%, respectively.

LEVEL OF EVIDENCE

Level IV, case series.

Intra-operative assessment of the vascularisation of a cross section of the meniscus using near-infrared fluorescence imaging

PURPOSE

The purpose of this study was to assess whether the vascularisation of the meniscus could be visualised intra-operatively using near-infrared fluorescence (NIRF) imaging with indocyanine green (ICG) in patients undergoing total knee arthroplasty (TKA).

METHODS

The anterior horn (i.e., Cooper classification: zones C and D) of the meniscus that was least affected (i.e., least degenerative) was removed during TKA surgery in ten patients to obtain a cross section of the inside of the meniscus. Thereafter, 10 mg of ICG was injected intravenously, and vascularisation of the cross section of the meniscus was assessed using the Quest spectrum NIRF camera system. We calculated the percentage of patients in whom vascularisation was observed intra-operatively using NIRF imaging compared to immunohistochemistry.

RESULTS

Meniscal vascularisation using NIRF imaging was observed in six out of eight (75%) patients in whom vascularisation was demonstrated with immunohistochemistry. The median extent of vascularisation was 13% (interquartile range (IQR) 3-28%) using NIRF imaging and 15% (IQR 11-23%) using immunohistochemistry.

CONCLUSION

This study shows the potential of NIRF imaging to visualise vascularisation of the meniscus, as vascularisation was observed in six out of eight patients with histologically proven meniscal vascularisation.

LEVEL OF EVIDENCE

IV.

Repair Technique for Displaced Meniscal Flap Tears Indicated by MRI Comma Sign

The meniscus comma sign has been described for displaced flap tears of the meniscus. These meniscus tears are displaced into the tibia or femoral recesses and can be often difficult to diagnose intraoperatively. We describe the technique of diagnosis and treatment of a large displaced lateral meniscus flap tear, presenting as a meniscus comma sign. The identification of the meniscus comma sign on consecutive magnetic resonance imaging (MRI) cuts suggest a flap tear of a significant size that indicates reparability. The technique would be to lift the meniscus flap from the meniscotibial recess, reduce it and then repair it with an all-inside meniscus repair or by hybrid meniscus repair techniques.

In-Office Needle Arthroscopy Can Evaluate Meniscus Tear Repair Healing as an Alternative to Magnetic Resonance Imaging

PURPOSE

To assess the healing of horizontal cleavage tears of the meniscus 1 year after surgical repair and to determine what modality is best to determine healing.

METHODS

Patients were prospectively followed for 12 months after surgical meniscus repair using a circumferential compression stitch. Inclusion criteria were preoperative magnetic resonance imaging (MRI) evidence of horizontal cleavage tear, age between 18 and 50 years, and no concomitant anterior cruciate ligament reconstruction. Patients were excluded if they were >50 years old, had a meniscus tear pattern other than horizontal cleavage tear, and underwent concomitant ligament reconstruction. MRIs were performed 1-year postoperatively for evaluation of repair healing. Preoperative and postoperative MRIs of tears were evaluated blindly by a musculoskeletal radiologist. In-office needle arthroscopy was performed at 6 months post-operatively.

RESULTS

Eight patients were included and had surgery between March 2016 and November 2017. There were 4 medial and 4 lateral meniscus tears. No patients had recurrence of preoperative symptoms or evidence of retear. Six repairs evaluated by in-office needle (at 5.9 months postsurgery) arthroscopy demonstrated complete healing. Seven of the 8 patients had grade III changes on preoperative MRI, and 1 patient had grade IIc changes. On postoperative MRI, 5 of 7 patients had grade III changes, 1 patient had IIc changes, and 1 had IIb changes. There was no significant difference in the proportion of patients with grade III changes preoperatively compared with postoperatively (P = .57). One of 8 patients with preoperative MRIs demonstrated extrusion where no patients demonstrate postoperative MRI evidence of extrusion (P = .47).

CONCLUSIONS

Horizontal cleavage meniscal tears repaired with a circumferential compression stitch demonstrate healing on in-office needle arthroscopy 6 months after surgery. No evidence of incomplete or failed healing was found. MRI at 1 year after surgery demonstrated residual tear evidence for all patients.

LEVEL OF EVIDENCE

IV, therapeutic case series.

Second-Look Arthroscopic Evaluation of Healing Rates After Arthroscopic Repair of Meniscal Tears: A Systematic Review and Meta-analysis

Background:

Evaluation of meniscal healing status after repair is important, as it allows the surgeon to inform patients whether they can increase their activities or return to sports.

Purpose:

To identify the healing rates after arthroscopic repair of meniscal tears via second-look arthroscopic evaluation.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

Searches of PubMed, Embase, Scopus, and the Cochrane databases were conducted to identify relevant studies published before June 1, 2020. Studies were eligible for this meta-analysis if they provided data regarding healing status of the meniscus at second-look arthroscopy. Random-effects meta-analyses were generated to provide pooled meniscal healing estimates. We further performed subgroup analysis to investigate the healing rates of the meniscus under different situations.

Results:

A total of 41 studies with 1908 individuals were included in the study. The pooled analysis showed the complete healing rate was 74% (95% confidence interval [CI], 67%-80%), the partial healing rate was 10% (95% CI, 6%-16%), and the failure rate was 12% (95% CI, 10%-15%) for arthroscopic repair of meniscal tears via second-look arthroscopic evaluation. Sensitivity analysis demonstrated that no individual study affected the overall healing rate by >1%. Subgroup analysis found higher meniscal healing rates in patients with the following characteristics: age <40 years, male, body mass index <26, red-red tear location, tear in posterior horn, vertical tear, outside-in technique, repair concomitant with anterior cruciate ligament reconstruction, weight-restricted rehabilitation, and time interval from meniscal repair to second-look arthroscopy >12 months.

Conclusion:

In this systematic review, the complete healing rate was 74%, the partial healing rate was 10%, and the failure rate was 12% for arthroscopic repair of meniscal tears via second-look arthroscopic evaluation.

H-Plasty Repair Technique Improved Tibiofemoral Contact Mechanics After Repair for Adjacent Radial Tears of Posterior Lateral Meniscus Root: A Biomechanical Study

PURPOSE

To compare the time-zero tibiofemoral contact mechanics among the 4 different suturing repairs: transtibial pullout suture repair, suture anchor repair, side-to-side repair, and H-plasty repair.

METHODS

Twenty-four human cadaveric knees were included. Each lateral meniscus condition (intact, radial tear, and repair) was tested under a 1000-N axial compressive load at 0°, 30°, 60°, and 90° of flexion. Four different repair techniques, transtibial pullout, suture anchor, side-to-side, and H-plasty repair technique, were tested. Tibiofemoral mean and peak contact pressure and contact area in the lateral and medial compartments were measured by Tekscan sensors.

RESULTS

Radial tears adjacent to the posterior lateral meniscus root produced significantly decreased contact area and increased mean and peak contact pressures in the lateral compartment across all angles (P < .05). All repair groups could improve the contact mechanics relative to the torn condition (P < .05), but only H-plasty repair showed no significant difference in the mean and peak contact pressure and contact area compared with that of the intact state at all flexion angles (P > .05).

CONCLUSIONS

The results showed that the tibiofemoral contact mechanics after adjacent radial tears of the posterior lateral meniscal root were improved to the intact level by H-plasty repair at time-zero. The additional vertical mattress sutures act as "stabilizers" to provide a more stable environment in distributing vertical tibiofemoral pressure. The other 3 repair techniques also significantly improved lateral tibiofemoral contact mechanics relative to the corresponding tear conditions.

CLINICAL RELEVANCE

The results of this study suggest that H-plasty repair can restore the biomechanical properties to the intact state. Since it was a time-zero cadaveric study, the results should be carefully used in clinical practices.

A Hospital Clinic Experience with Isolated Lateral Meniscal Tears in Sports: A Chart Review on Rugby

Background: Rugby is a contact sport, and the frequency of injuries is high. In our clinical experience with patients diagnosed arthroscopically with lateral meniscus tears in the middle segment, rugby players are more prevalent than players of other sports. We hypothesized that a meniscus tear in the middle segment is a common injury in rugby players and is associated with specific positions in rugby. Objectives: This study aimed to describe a series of lateral meniscus tears in rugby players. Methods: We retrospectively reviewed the medical charts of cases with an arthroscopically confirmed isolated lateral meniscus tear in the middle segment associated with rugby players in our center between 2006 and 2020. We investigated the epidemiology of injury, including the player position and phase of play, the symptoms; as well as imaging and arthroscopic findings. Results: Of 4452 cases (4666 knees) diagnosed arthroscopically with meniscus tears, 27 cases (28 knees) were isolated radial lateral meniscus tears in the middle segment, 26 of which were sports-associated, including 11 cases related to rugby. Among the 11 rugby players, 10 were forwards, 5 of whom were in the front row. The injury was associated with a tackle in 4 patients, while the phase of play of injury was unknown in 6 patients. In the clinical manual examination, tenderness and a positive hyperextension test had a relatively high sensitivity. In imaging examination, MRI depicted a characteristic image of a partial meniscal defect in the sagittal view. All patients underwent arthroscopic partial meniscectomy. The postoperative course was favorable. All patients returned to play rugby at the pre-injury competition level. Conclusions: In this study, radial lateral meniscus tears involving the middle segment frequently occurred in rugby players, mostly in forward positions. Arthroscopic partial meniscectomy achieved a return to play in all players.

Clinical, Radiographic, and Arthroscopic Outcomes of Surgical Repair for Radial and Avulsed Lesions on the Lateral Meniscus Posterior Root During ACL Reconstruction: A Systematic Review

Background

Clinical outcomes of surgical repairs for tears of the lateral meniscus posterior root (LMPR) in patients undergoing anterior cruciate ligament (ACL) reconstruction (ACLR) have not been comprehensively investigated.

Purpose

To systematically review the clinical, radiographic, and arthroscopic results of surgical repairs for tears of the LMPR in patients undergoing ACLR.

Study Design

Systematic review; Level of evidence, 4.

Methods

A systematic electronic search of the PubMed and Embase databases was performed to identify studies reporting clinical, radiographic, or arthroscopic results of surgical repairs for tears of the LMPR in patients undergoing ACLR. Each included study was abstracted regarding study characteristics, patient characteristics, surgical technique, and outcome measures. The methodological quality of the included studies was analyzed according to the Methodological Index for Non-Randomized Studies (MINORS) criteria.

Results

Nine studies were included in this systematic review, representing a total of 215 knees in 215 patients. Overall, 123 side-to-side repairs and 89 pullout repairs were performed for tears of the LMPR during ACLR. After a mean follow-up of 33.9 months, significant improvements (P < .05) were found in the mean Lysholm score (from 58.3 to 91.4) as well as the mean International Knee Documentation Committee subjective score (from 61.1 to 87.2). Weightbearing anteroposterior radiographs of 41 patients showed no significant narrowing of lateral joint space width. On magnetic resonance imaging scans, 31 patients demonstrated no significant progression of chondral lesions, and no significant decreases in meniscal extrusion on coronal planes were reported in another 76 patients. The complete/partial healing was 93.6% on second-look arthroscopy after side-to-side repairs for radial tears of the LMPR. The MINORS value showed a high risk of bias for all 9 studies.

Conclusion

Patients with tears of the LMPR associated with ACL injuries achieved favorable functional scores after ACLR and LMPR repairs, and the side-to-side repair for radial tears of the LMPR succeeded in a high meniscal healing rate of >90%. However, the authors of this review were unable to definitively conclude whether LMPR repairs fully restore the hoop stress of the lateral meniscus.

Outcomes More Than 2 Years After Meniscal Repair for Longitudinal Tears of the Lateral Meniscus Combined With Anterior Cruciate Ligament Reconstruction

BACKGROUND

Meniscal function after repair of longitudinal tears of the lateral meniscus (LM) with anterior cruciate ligament reconstruction (ACLR) has not been comprehensively investigated.

PURPOSE

To evaluate not only the clinical outcomes and radiographic findings of patients who underwent repair of longitudinal tears of the LM combined with ACLR but also the healing status of the repaired meniscus and changes in chondral status with second-look arthroscopy.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Among 548 patients who underwent primary anatomic ACLR at our institution between 2010 and 2017, 39 who had concomitant longitudinal tears of the LM and underwent repair were studied. During follow-up for more than 2 years, all patients were evaluated clinically (pain, range of motion, swelling, and knee instability) and with imaging (plain radiograph and magnetic resonance imaging [MRI]), and compared with a matched control group (based on age, sex, body mass index, and follow-up period) without any concomitant injuries who underwent ACLR. Measurements on MRI were recorded preoperatively, immediately after surgery, and at final follow-up, and the change in the values over time was assessed. Of the 39 patients in each group, 24 were assessed by second-look arthroscopy with hardware removal 2 years postoperatively.

RESULTS

The mean follow-up times of the study and control group were at a mean of 42.4 and 45.4 months, respectively. There were no significant differences in clinical findings, lateral joint space narrowing on radiographs, and chondral status at the lateral compartment between groups, whereas lateral and posterior meniscal extrusion on MRI progressed significantly in the study group (0.43 ± 1.0 mm vs -0.29 ± 1.1 mm, P = .003; 1.9 ± 1.9 mm vs 0.14 ± 1.1 mm, P < .0001, respectively). Second-look arthroscopy revealed complete healing in 12 patients (50%), partial healing in 9 (37.5%), and failure in 3 (12.5%) in the study group, and no new tear in the control group.

CONCLUSION

The clinical and imaging outcomes after repair of longitudinal tears of the LM combined with anatomic ACLR were successful and comparable with those after isolated ACLR without any other injuries at 42 months postoperatively, although meniscal extrusion showed progression on coronal/sagittal MRI. Based on the MRI findings and the result that only half of patients achieved complete healing, meniscal function could not be fully restored even after repair. Although degenerative changes were not apparent, longer-term follow-up is needed.

Editorial Commentary: Efforts to Heal Meniscal Radial Tears Are Ongoing

Meniscal radial tears are equivalent to the meniscectomized state. However, successful healing rates by current repair methods for meniscal radial tears are still not satisfactory. Several suture configurations that could approximate the tear gap and stabilize meniscal tissue have been developed to overcome the shortcomings of simple horizontal stitches and cross stitches. The hybrid stitch method, composed of horizontal stitches and vertical stitches, has been introduced. This method can provide stable fixation because the vertical stitches suture the bundle of circumferential fibers, and the vertical stitches act as rip stops for the horizontal stitches. However, it is still challenging to heal meniscal radial tears in avascular areas or complex tears. In treating radial tears, it is important not only to improve suture mechanics but also to promote biologic healing potential.

Tibiofemoral Contact Mechanics After Horizontal or Ripstop Suture in Inside-Out and Transtibial Repair for Meniscus Radial Tears in a Porcine Model

PURPOSE

To compare tibiofemoral contact mechanics after horizontal or ripstop (horizontal plus vertical) sutures in inside-out and transtibial repair for meniscal radial tears with 10 porcine knees in each group.

METHODS

Ten matched pairs of porcine knees were tested under a 1500-N axial compressive load at 0°, 30°, 60°, and 90° of knee flexion. Each knee underwent 4 testing conditions consecutively: (1) intact, (2) medial meniscal radial tear, (3) horizontal suture repair configuration, and (4) ripstop suture repair configuration. Tekscan sensors measured tibiofemoral contact pressure and contact area in the medial and lateral compartments.

RESULTS

All repair groups improved their contact mechanics when compared with the tear state among all flexion angles analyzed (all P < .05). Furthermore, ripstop sutures with both inside-out and transtibial repairs restored intact knee contact area and pressures (peak and mean) in the medial compartment at all flexion angles, whereas the horizontal sutures alone failed to do so for contact pressures at 60° and 90° and for contact surface areas at all flexion angles. However, the aforementioned parameters were not significantly different between inside-out sutures and transtibial sutures, regardless of horizontal or ripstop configuration (P > .05).

CONCLUSIONS

Radial tears of the meniscus in a porcine model significantly decreased medial contact area and increased mean and peak contact pressure. Both inside-out and transtibial ripstop repairs for radial tears aid in restoring intact tibiofemoral contact mechanics at all assessed knee flexion angles.

CLINICAL RELEVANCE

Our results suggest that both inside-out and transtibial ripstop repairs for radial tears can restore tibiofemoral contact mechanics to the intact state. Since the study were performed in an open fashion porcine model, the results should be carefully used in clinical practices, and the efficacy of the techniques through arthroscopic method should be further explored.

Full-Thickness Radial Medial Meniscal Tear: Fixation With Inside-Out Technique With Tibial Knotless Suture Anchors

Complete radial tears of the meniscus render the entirety of the meniscus functionally incompetent (known as an ameniscal state); therefore, attempts at repair are essential. Although various techniques have been described, repair failures continue to frequently occur, especially with the medial meniscus. Inside-out repair and anchoring of the preserved meniscus to both the capsule and tibia may offer the advantage of a more robust repair. The objective of this Technical Note is to describe a method of repair for complete radial tears of the medial meniscus using a combination of inside-out sutures and secondary reinforcement to the tibia using all-suture knotless anchors.

Successful treatment of degenerative medial meniscal tears in well-aligned knees with fibrin clot implantation

PURPOSE

The purpose of this study was to examine the results of meniscal repair performed for symptomatic degenerative medial meniscal tears.

METHODS

Twenty-four knees in 24 patients with symptomatic degenerative medial meniscal tears (mostly complex horizontal tears) who underwent isolated arthroscopic repair combined with autologous fibrin clot implantation were included in this study. The patients were followed up for a minimum of 2 years. The overall clinical outcome was evaluated using the Lysholm score, while the activity level was graded on the Tegner Activity Scale. The assessment of healing status at the repair site was based on clinical signs/symptoms and follow-up MRI examination results. In addition, the effects of the patient's clinical and radiological factors on healing of the repaired menisci were analyzed.

RESULTS

The mean age of the study subjects was 47.0 ± 8.1 years with a mean follow-up period of 39.3 ± 11.6 months. The Lysholm score significantly improved after surgery (P < 0.01). During the follow-up period, meniscal repairs were deemed to have failed in 6 of the 24 knees (25%). In the analysis of factors influencing meniscal healing, varus deformity (% of mechanical axis < 30%) was identified in all knees in the repair failure group, and the presence of varus deformity was shown to be a significant risk factor correlated with repair failure, while other factors did not significantly influence the healing status.

CONCLUSIONS

The short-term follow-up results showed that arthroscopic repair of degenerative medial meniscal tears combined with fibrin clot implantation attained clinical healing in 18 of 24 knees (75%) of patients, while 6 of the 24 knees (25%) of patients experienced clinical failure. The presence of varus deformity negatively affects the healing rate. In well-aligned knees, degenerative medial meniscal tears are successfully treated by isolated repair with fibrin clot implantation.

LEVEL OF EVIDENCE

IV.

Clinical evaluation of micro-fragmented adipose tissue as a treatment option for patients with meniscus tears with osteoarthritis: a prospective pilot study

Purpose

The management of knee pain secondary to meniscal tears with osteoarthritis is limited by the poor inherent healing potential of the meniscus. Previous studies have reported on the benefit of autologous micro-fragmented fat as a therapeutic for various knee pathologies. The goal of this prospective pilot study was to determine the safety and potential treatment effect of micro-fragmented adipose tissue injection for patients with knee pain secondary to osteoarthritis and meniscal tears who have failed conservative management.

Methods

Twenty subjects with knee pain secondary to osteoarthritis with associated meniscal tear after failed conservative management were enrolled in the study. Numeric Pain Scale (NPS) and Knee Injury and Osteoarthritis Outcome Scale (KOOS) following ultrasound-guided intra-meniscal and intra-articular micro-fragmented adipose tissue injections were examined at three, six and 12 months.

Results

The mean NPS revealed a significant decrease in patient pain at the 1-year time point compared with baseline (5.45 to 2.21, p < .001). Similarly, overall, mean KOOS symptoms significantly improved from 57.7 to 78.2 (p < .001), with all 4 KOOS subscales demonstrating significant improvement at the final one year follow-up. One subject developed uncomplicated cellulitis at the harvest site which was treated with oral antibiotics. Other complications were minor and mostly limited to adipose harvest.

Conclusion

This study demonstrated that micro-fragmented adipose tissue injected directly into a torn meniscus and knee joint using ultrasound guidance represents a safe and potentially efficacious treatment option for patients with knee pain suffering from degenerative arthritis and degenerative meniscal tears. A larger, randomized, controlled trial is warranted to determine efficacy.

Trial registration

Clinicaltrials.org Identifier: NCT03714659

Radial Meniscal Tears Are Best Repaired by a Modified "Cross" Tie-Grip Suture Based on a Biomechanical Comparison of 4 Repair Techniques in a Porcine Model

Background:

The tie-grip suture can fix radial tears more rigidly than simple conventional sutures. However, one shortcoming is the residual gap at the central margin of the tear. The tie-grip suture was modified to address this issue and named the “cross tie-grip suture.”

Purpose/Hypothesis:

The purpose of this study was to compare the suture stability and strength among 4 suturing techniques: the original tie-grip, cross tie-grip, and 2 conventional sutures (double horizontal and cross). It was hypothesized that the cross tie-grip suture would show the least displacement and resist the greatest maximum load.

Study Design:

Controlled laboratory study.

Methods:

A total of 40 fresh-frozen porcine knees were dissected to acquire 80 menisci; 20 menisci were tested in each suture group. A radial tear was created at the middle third of the meniscal body. Repair was performed with the following: original tie-grip, cross tie-grip, double horizontal, and cross sutures. The mechanical strength of sutured menisci was evaluated using a tensile testing machine. All menisci underwent submaximal loading and load to failure. The gap distance and ultimate failure load were compared using analysis of variance. The failure mode was recorded after load-to-failure testing.

Results:

Displacement after 500 cycles was significantly smaller in the cross tie-grip group (0.4 ± 0.3 mm) compared with the tie-grip (0.9 ± 0.6 mm), double horizontal (1.2 ± 0.7 mm), and cross suture groups (1.4 ± 0.6 mm) (P < .05). The ultimate failure load was significantly greater in the cross tie-grip (154.9 ± 29.0 N) and tie-grip (145.2 ± 39.1 N) groups compared with the double horizontal (81.2 ± 19.9 N) and cross suture groups (87.3 ± 17.7 N) (P < .05). Tissue failure was the most common mode of failure in all groups.

Conclusion:

Upon repair of radial meniscal tears, the cross tie-grip suture showed less displacement compared with that of the tie-grip, double horizontal, and cross sutures and demonstrated equivalent load to failure to that of the tie-grip suture at time zero.

Clinical Relevance:

The cross tie-grip suture provided high resistance to displacement after repair of radial tears and may be advantageous in healing for radial meniscal tears.

All-Inside Suture Repair for Isolated Radial Tears at the Midbody of the Lateral Meniscus

In young athletes, radial tear of the midbody on the semilunar lateral meniscus in stable knees is most common. Conventionally, for this type of tear, meniscectomy has been considered as a first-line treatment. However, meniscectomy does not prevent degenerative change. Therefore, repair is another treatment option for a full radial tear, though this type of tear can be difficult to repair because of the lack of a vascular supply. Compared with conventional transcapsular suture techniques (e.g., inside-out/outside-in techniques or all-inside techniques with implants), all-inside suture (AIS) repair techniques can avoid bunching of the meniscus to the capsule. AIS is considered suitable for restoration of normal structure and movement of the meniscus after repair, which can be advantageous for meniscal healing. However, AIS repair for an isolated radial tear at the midbody of the lateral meniscus has rarely been reported. Therefore, we applied the AIS repair technique for isolated radial tear at the midbody of the semilunar lateral meniscus using a QuickPass SutureLasso with 2-0 FiberWire. This procedure is easier and less invasive, shortening the gap by drawing each stump of the meniscus in the direction of the circumference.

Outcomes More Than 2 Years After Meniscal Repair for Radial/Flap Tears of the Posterior Lateral Meniscus Combined With Anterior Cruciate Ligament Reconstruction

BACKGROUND

Meniscal function after repair of radial/flap tears of the posterior horn of the lateral meniscus (LM) with anterior cruciate ligament reconstruction (ACLR) has not been comprehensively investigated.

PURPOSE

To evaluate not only the clinical and radiographic outcomes of patients with repair of radial/flap tears of the posterior LM with ACLR but also the healing status of the repaired meniscus and changes of chondral status with second-look arthroscopy.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

From January 2008 to April 2016, 41 patients of a consecutive series of 505 primary anatomic ACLR cases had a concomitant radial/flap tear of the posterior horn of the LM and underwent side-to-side repair with an inside-out or all-inside technique. All patients were followed for >2 years, evaluated clinically and radiologically (radiograph and magnetic resonance imaging [MRI]), and compared with a control group without any concomitant injuries that underwent ACLR. Of the 41 patients, 30 were assessed by second-look arthroscopy 2 years postoperatively.

RESULTS

The mean follow-up times of the study and control groups were 3.4 and 3.9 years, respectively. The study group showed no significant differences in clinical findings, lateral joint space narrowing on radiograph, and coronal extrusion on MRI as compared with the control group, whereas sagittal extrusion on MRI progressed significantly in the study group (1.2 ± 1.5 mm vs 0.32 ± 1.0 mm, P < .001). Eighteen patients (60%) obtained complete healing; 9 (30%) showed partial healing; and 3 (10%) failed to heal on second-look arthroscopy. Changes of chondral status in the femoral condyle showed no significant difference between the groups (P = .29). However, chondral status of the lateral tibial plateau worsened significantly in the study group (P = .0011).

CONCLUSION

The clinical and radiographic outcomes after repair of radial/flap tears of the posterior horn of the LM as combined with anatomic ACLR were successful and comparable with those after isolated ACLR without any other injuries at a mean postoperative follow-up of 3.4 years, except for sagittal extrusion on MRI. Chondral lesions of the lateral tibial plateau deteriorated regardless of meniscal healing at 2 years postoperatively. Surgeons should keep in mind that chondral injuries might progress over the midterm.

The rebar repair for radial meniscus tears: a biomechanical comparison of a reinforced suture repair versus parallel and cross-stitch techniques

Background

Radial meniscus tears can cause the meniscus to be completely incompetent. This serious type of meniscus tear can be difficult to repair. Techniques have been developed that juxtapose the meniscus tear edges and are able to withstand high loads. The purpose of this study was to determine the load to failure of a reinforced suture bar repair (Rebar Repair) for radial meniscus tear and compare it to the parallel suture technique and cross-stitch technique and to compare mode of failure among all three groups. The hypothesis was that the Rebar Repair will have a higher load to failure than both the parallel technique and the cross-stitch technique and that the Rebar Repair would have a lower rate of suture cutting through the meniscus.

Methods

Forty-eight menisci were tested from 24 human knee specimens, with 16 menisci in each group evenly distributed between medial and lateral menisci. Radial mid body meniscal tears were recreated and repaired with one of three inside-out techniques: the 2-parallel suture technique, 2 cross-stitch sutures, and the Rebar Repair. The specimens were cycled between 5 N to 30 N and axially loaded to failure perpendicularly across the repair site.

Results

The average load to failure of the parallel group, cross-stitch group and Rebar Repair was 85.5 N ± 22.0, 76.2 N ± 28.8 and 124.1 N ± 27.1 respectively. The Rebar Repair had a higher load to failure than the parallel group (p < 0.01) and cross-stitch group (p < 0.01). There was no difference in the load to failure between the cross-stitch and parallel group (p = 0.49). The failure mechanism was different when comparing the 3 groups (p < 0.01). The predominant mode of failure for both the parallel and cross-stitch group was suture cutout through the meniscus (88% and 94% respectively). The Rebar Repair failed due to suture rupture in 50% and suture cutout through the meniscus in 50%.

Conclusion

The Rebar Repair for radial meniscus tear has a higher load to failure and a lower rate of suture cutout through the meniscus than the parallel technique and cross-stitch technique.

Clinical relevance

Radial meniscus tears lead to decreased hoop stresses of the meniscus and effectively a non-functional meniscus. Newer techniques may have a higher load to failure leading to more successful repairs.

Enhanced repair of meniscal hoop structure injuries using an aligned electrospun nanofibrous scaffold combined with a mesenchymal stem cell-derived tissue engineered construct

Damage to the meniscal hoop structure results in loss of biomechanical function, which potentially leads to the extrusion of the meniscus from the weight bearing area. However, there have been no established, effective treatments for such injuries. The purpose of this study was to investigate the applicability of cell-seeded nanofibrous scaffolds to repair the damaged meniscal hoop structure along with the prevention of subsequent cartilage degeneration using a rabbit model. Meniscal radial defects (5 mm width) in the medial meniscus were treated by wrapping and suturing with either an aligned electrospun nanofibrous scaffold alone or a scaffold combined with a tissue engineered construct (TEC) derived from synovial mesenchymal stem cells (MSCs), with the scaffold fiber direction matching that of the meniscal circumferential fibers. The MSC-based TEC-combined nanofibrous scaffolds contributed significantly to the prevention of meniscal extrusion and exerted a chondroprotective effect, compared with either scaffold alone or the untreated control groups. Also, meniscal defects treated with such TEC-combined nanofibrous scaffolds were consistently repaired with a fibrocartilaginous tissue. In this study, we have demonstrated the feasibility of a combined TEC-nanofibrous scaffold to repair the meniscal hoop structure, and prevent the progression to cartilage degeneration, as a potential tissue engineering method.

Meniscal repair and regeneration: Current strategies and future perspectives

The management of meniscal injuries remains difficult and challenging. Although several clinical options exist for the treatment of such injuries, complete regeneration of the damaged meniscus has proved difficult due to the limited healing capacity of the tissue. With the advancements in tissue engineering and cell-based technologies, new therapeutic options for patients with currently incurable meniscal lesions now potentially exist. This review will discuss basic anatomy, current repair techniques and treatment options for loss of meniscal integrity. Specifically, we focus on the possibility and feasibility of the latest tissue engineering approaches, including 3D printing technologies. Therefore, this discussion will facilitate a better understanding of the latest trends in meniscal repair and regeneration, and contribute to the future application of such clinical therapies for patients with meniscal injuries.