Inside-out meniscus repair

Short-term outcomes of 43 dogs treated with arthroscopic suturing for meniscal tears associated with cranial cruciate ligament disease

OBJECTIVE

To describe short-term outcomes and complications in dogs receiving meniscal suturing and concurrent tibial plateau leveling osteotomy (TPLO) with or without augmentation with an extracapsular suture.

STUDY DESIGN

Retrospective case series.

ANIMALS

Forty-three client-owned dogs submitted for cruciate ligament disease.

METHODS

Dogs were included if meniscal suturing was performed during or after a TPLO procedure. Criteria included an unstable medial meniscus without evidence of a tear, a caudal vertical longitudinal tear with or without displacement, or if a bucket-handle tear was debrided and the remaining rim was unstable. Stifle stabilization was performed by either a standard TPLO or an augmented TPLO (TPLO + internal brace [IB]). Outcome measures included physical examination findings, radiographs, subjective gait examination, Liverpool Osteoarthritis in Dogs (LOAD) scores, and second-look arthroscopy.

RESULTS

Forty-four meniscal repairs were performed in 43 dogs. Five types of meniscal tears were treated employing eight suture materials. Complications were documented in 15 cases (34%). The stabilization technique had a significant impact on the outcome (p = .049): TPLO + IB had a 93.3% success rate and the success rate was 71.4% in the TPLO-only group.

CONCLUSION

Five types of meniscal pathology were addressed successfully in the study, indicating that currently accepted criteria for meniscal suturing in dogs may be overly conservative. The majority of complications were not related to the meniscal suturing itself and did not compromise the outcome. The stifle stabilization technique had an impact on outcome.

CLINICAL SIGNIFICANCE

The authors found arthroscopic meniscal suturing to be practical and successful in this patient population. Postoperative stifle stability had an impact on successful treatment.

Neither All-Inside, nor Inside-Out, nor Outside-In Repair Demonstrates Superior Biomechanical Properties for Vertical Meniscal Tears: A Systematic Review of Human Cadaveric Studies

PURPOSE

To systematically review the literature regarding the biomechanical properties of different repair techniques and fixation methods for vertically oriented meniscal tears.

METHODS

Human cadaveric studies evaluating the biomechanical properties of different repair techniques for vertically oriented meniscal tears were identified using the PubMed, EMBASE, and Cumulative Index to Nursing & Allied Health databases. Primary outcomes included load to failure, displacement, stiffness, peak contact pressure, and contact area of repaired menisci. Repair techniques from included studies were reclassified into a total of 19 distinct all-inside (AI), inside-out (IO), or outside-in (OI) techniques.

RESULTS

Sixteen studies were included (420 total menisci). Contact pressure and area were restored to intact-state values across all 5 compressive load studies at low knee flexion angles but not at greater knee flexion angles (i.e., >60°). There were no significant differences in contact pressure or area between AI, IO, and OI techniques across all studies. Some studies demonstrated statistically significant advantages in tensile properties with IO techniques when compared with AI techniques, whereas others found AI techniques to be superior. No studies directly compared tensile properties of OI techniques with those of AI or IO techniques. Vertical mattress suture configurations resulted in significantly greater load to failure and decreased displacement compared with horizontal mattress configurations in 67% of studies comparing the 2 techniques. There was no difference in the rate of tissue failure in AI (66.97%), IO (60.38%), or OI (66.67%, χ2 = 0.83, P = .66) techniques.

CONCLUSIONS

Contact mechanics are reliably restored after repair of vertical meniscal tears at low flexion angles but inconsistently restored at greater flexion angles, regardless of technique. Vertical mattress configurations outperformed horizontal mattress configurations under tensile load. There are conflicting data regarding the comparison of tensile properties between AI and IO techniques. Ultimately, neither AI, IO, nor OI repair demonstrated superior biomechanical properties in the present literature.

CLINICAL RELEVANCE

Several repair techniques demonstrate favorable biomechanical properties for vertical meniscal tears under tensile and compressive loads. Neither AI, IO, nor OI repair techniques demonstrate superior biomechanical properties at this time.

All-Soft-Tissue Meniscus Allograft Transplantation With Circumferential Suture Tape Augmentation to Mitigate Hoop Stress and Promote Centralization

Meniscus allograft transplantation (MAT) is a technically challenging procedure. Bone plugs, slot techniques, and all-soft-tissue fixation techniques have been described in the past. Each technique comes with advantages and disadvantages. Native menisci have circumferential collagen fibers to help resist hoop stress during loading cycles. Although hoop stress resistance is a known function of the menisci, its recreation in MAT has only been targeted indirectly through anatomic root placement. The authors describe the use of a high-tensile suture tape (i.e. InternalBrace) to promote centralization by directly mitigating hoop stresses through recreation of peripheral meniscus tensioning in MAT.

More Is Not Merrier: Increasing Numbers of All-Inside Implants Do Not Correlate with Higher Odds of Revision Surgery

The purpose of this study was to evaluate the relationship between the number of all-inside meniscal repair implants placed and the risk of repair failure. We hypothesized that the use of higher numbers of all-inside meniscus repair implants would be associated with increased failure risk. A retrospective chart review identified 351 patients who underwent all-inside meniscus repair between 2006 and 2013 by a sports medicine fellowship-trained orthopaedic surgeon at a single institution. Patient demographics (age, body mass index [BMI], sex) and surgical data (number of implants used, concomitant anterior cruciate ligament reconstruction [cACLR], and tear type/size/location) were recorded. Patients who received repairs in both menisci or who had follow-up < 1-year postoperatively were excluded. Repair failure was identified through chart review or patient interviews defined as a revision surgery on the index knee such as partial meniscectomy, total knee arthroplasty, meniscus transplant, or repeat repair. Logistic regression modeling was utilized to evaluate the relationship between the number of implants used and repair failure. A total of 227 all-inside meniscus repairs were included with a mean follow-up of 5.0 ± 3.0 years following surgery. Repair failure was noted in 68 knees (30.3%)-in 28.1% of knees with fewer than four implants and in 35.8% of knees with four or more implants (p = 0.31). No significant increase in failure was observed with increasing number of all-inside medial (odds ratio [OR]: 1.15; 95% confidence interval [CI]: 0.79-1.7; p = 0.46) or lateral (OR: 0.86; 95% CI: 0.47-1.57; p = 0.63) implants after controlling for patient age, BMI, cACLR, tear type, or size. Tears of the lateral meniscus located in the red-white and white-white zones had lower odds of failure (OR: 0.14; 95% CI: 0.02-0.88; p = 0.036) than tears within the red-red zone, and patients with cACLR had lower odds of repair failure (OR: 0.40; 95% CI: 0.18-0.86, p = 0.024) than those without. The number of all-inside implants placed during meniscus tear repair did not affect the likelihood of repair failure leading to reoperation after controlling for BMI, age, tear type, size, location, and cACLR. LEVEL OF EVIDENCE:  III.

Changes in Functional Meniscal Morphology During Skeletal Growth and Maturation

Background

Little is known on how meniscal morphology develops during skeletal growth and maturation and its subsequent relationship with the corresponding bony anatomy.

Hypotheses

(1) Meniscal dimensions and morphology would change by age during skeletal growth and maturation in different ways in boys compared with girls. (2) Morphological features of the medial and lateral menisci would correlate to medial and lateral femoral condyle curvatures.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

Anatomic features of the medial and lateral menisci were measured on magnetic resonance imaging scans from 269 unique knees (age, 3-18 years; 51% female) with no prior history of injury, congenital or growth-related skeletal disorders, or bony deformities. Morphological shape-based measurements were normalized to tibial plateau width or determined as ratios of meniscal dimensions. The association between age and anatomy was analyzed with linear regression. Two-way analysis of variance with the Holm-Šídák post hoc method was used to compare anatomy between sexes in different age groups. Linear regression was used to evaluate the relationship between femoral condyle curvature radius and meniscal morphology in each compartment after adjusting for age and sex.

Results

Meniscal length, width, horn distance, mean cross-sectional area (CSA), and mean height increased with age in both sexes (R2 > 0.1; P < .001). Age-related changes in meniscal morphology were seen in normalized length, width, horn distance, and mean height; width-to-length ratio; horn distance-to-length ratio (lateral meniscus only); normalized mean CSA (except lateral meniscus in girls); and mean tip angle (R2 > 0.04; P < .02). Sex-based differences were also found, with some morphological differences (normalized length and height) throughout development (P < .03) and size differences (length, width, and mean CSA) in later development (P < .01). After adjusting for age and sex, there were significant correlations between medial condyle curvature radius and normalized width, width-to-length ratio, horn distance, horn distance-to-length ratio, mean CSA, and mean height of the medial meniscus (P≤ .041) and between lateral condyle curvature radius and normalized length, mean height, and mean tip angle of the lateral meniscus (P≤ .004).

Conclusion

Age-related changes in meniscal dimensions and morphology, most notably a nonuniform growth pattern in meniscal geometry, occurred during skeletal growth and maturation, with different trends in boys than in girls.

Continuous Vertical Inside-Out Versus Traditional Vertical Inside-Out Meniscal Repair: A Biomechanical Comparison

Background

Biomechanical assessment of meniscal repairs is essential for evaluating different meniscal suturing methods and techniques. The continuous meniscal suture technique is a newer method of meniscal repair that may have biomechanical differences compared with traditional techniques.

Purpose

To evaluate the displacement, stiffness after cyclical loading, and load to failure for a continuous vertical inside-out meniscal suture versus a traditional vertical inside-out meniscal suture in a porcine medial meniscus.

Study Design

Controlled laboratory study.

Methods

A total of 28 porcine knees were acquired and divided into 2 test groups of 14 medial meniscus each. A 2.0-cm longitudinal red-white zone cut was made in the body of the medial meniscus for each knee. The continuous suture (CS) group received 4 vertical stitches performed with a continuous vertical meniscal suture technique, and the inside-out suture (IO) group received a traditional vertical suture with 4 stitches. Two traction tapes were passed between the sutures and positioned in the biomechanical testing fixture device. Each specimen underwent load-to-failure testing at 5 mm/s, and displacement, system stiffness, and maximum load to failure were compared between the groups.

Results

The displacement after the cyclic test was 0.53 ± 0.12 and 0.48 ± 0.07 mm for the CS and IO groups, respectively. There was no significant difference between the groups (P = .2792). The stiffness at the ultimate load testing was 36.3 ± 1.9 and 35.3 ± 2.4 N/mm for groups CS and IO, respectively, with no significant difference between the groups (P = .2557). In the load-to-failure test, the ultimate load was 218.2 ± 63.9 and 238.3 ± 71.3 N in the CS and IO groups, respectively, with no significant group differences (P = .3062).

Conclusion

A continuous vertical meniscal suture created a configuration for treating longitudinal meniscal lesions that was beneficial and biomechanically similar to a traditional vertical suture technique.

Clinical Relevance

The study findings indicate that use of the continuous vertical inside-out meniscal suture technique is a possible therapeutic option.

Greater rate of return to play and re-injury following all-inside meniscal repair compared to the inside-out technique: a systematic review

INTRODUCTION

Inside-out and all-inside arthroscopic meniscal repairs are widely performed. However, it remains unclear which method promotes greater clinical outcomes. This study compared inside-out versus all-inside arthroscopic meniscal repair in terms of patient-reported outcome measures (PROMs), failures, return to play, and symptoms.

METHODS

This systematic review was conducted in accordance with the PRISMA guidelines. Two authors independently performed the literature search by accessing the following databases: PubMed, Google Scholar, and Scopus in February 2023. All clinical studies which investigated the outcomes of all-inside and/or inside-out meniscal repair were considered.

RESULTS

Data from 39 studies (1848 patients) were retrieved. The mean follow-up was 36.8 (9 to 120) months. The mean age of the patients was 25.8 ± 7.9 years. 28% (521 of 1848 patients) were women. No difference was found in PROMs: Tegner Activity Scale (P = 0.4), Lysholm score (P = 0.2), and International Knee Document Committee score (P = 0.4) among patients undergoing meniscal repair with all inside or inside-out techniques. All-inside repairs showed a greater rate of re-injury (P = 0.009) but also a greater rate of return to play at the pre-injury level (P = 0.0001). No difference was found in failures (P = 0.7), chronic pain (P = 0.05), reoperation (P = 0.1) between the two techniques. No difference was found in the rate of return to play (P = 0.5) and to daily activities (P = 0.1) between the two techniques.

CONCLUSION

Arthroscopic all-inside meniscal repair may be of special interest in patients with a particular interest in a fast return to sport, while, for less demanding patients, the inside-out suture technique may be recommended. High-quality comparative trials are required to validate these results in a clinical setting.

LEVEL OF EVIDENCE

Level III, systematic review.

Efficacy of meniscus suture absorbability on meniscus healing success rate via second-look arthroscopy after meniscal repair: a systematic review and meta-analysis

BACKGROUND

To preserve the meniscus's function, repairing the torn meniscus has become a common understanding. After which, the search for the ideal suture material is continuous. However, it is still controversial about the efficacy of suture absorbability on meniscus healing.

METHODS

This review is designed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

INCLUSION CRITERIA

(1) Studies on meniscus repair; (2) Second-look arthroscopy was performed; (3) The meniscus was repaired by absorbable and non-absorbable sutures; (4) The healing condition of repaired meniscus via second-look arthroscopy was described.

EXCLUSION CRITERIA

(1) Animal studies, cadaveric studies, or in vitro research; (2) Meniscus transplantation; (3) Open meniscus repair; (4) Reviews, meta-analysis, case reports, letters, and comments; (5) non-English studies. MEDLINE, Embase, and Cochrane Database were searched up to October 2022. Risk of bias and methodology quality of included literature were assessed according to ROBINS-I and the modified Coleman Methodological Scale (MCMS). Descriptive analysis was performed, and meta-analysis was completed by RevMan5.4.1.

RESULTS

Four studies were included in the systematic review. Among them, three studies were brought into the meta-analysis, including 1 cohort study and 2 case series studies about 130 patients with meniscal tears combined with anterior cruciate ligament injury. Forty-two cases were repaired by absorbable sutures, and 88 were repaired by non-absorbable sutures. Using the fixed effect model, there was a statistical difference in the healing success rate between the absorbable and the non-absorbable groups [RR1.20, 95%CI (1.03, 1.40)].

CONCLUSION

In early and limited studies, insufficient evidence supports that non-absorbable sutures in meniscus repair surgery could improve meniscal healing success rate under second-look arthroscopy compared with absorbable sutures. In contrast, available data suggest that absorbable sutures have an advantage in meniscal healing.

TRIAL REGISTRATION

The review was registered in the PROSPERO System Review International Pre-Registration System (Registration number CRD42021283739).

Anterolateral Radial Meniscus Tear Repair using Traction Suture and Super-Hashtag Technique

Radial meniscus tears occur commonly as traumatic tears in younger patients, as well as in association with concomitant degenerative changes. Traditional management of these tears has centered around partial meniscectomy; however, there has been a more recent trend toward preserving the meniscus and attempting repair. Because of the gapping and displacement that frequently occurs with these tears, repair is often challenging and is done under high amounts of tension. The following article describes a technique using a traction suture to aid in maintaining reduction throughout repair. This is followed by the use of a combination of techniques to form a "super-hashtag" configuration of both vertical and horizontal mattress sutures, leading to a secure repair under little tension.

Using a Combined All-Inside, Inside-Out, and Outside-In Technique to Repair Bucket-Handle Medial Meniscal Tears Without a Safety Incision

We describe a combined all-inside, inside-out, and outside-in technique for the repair of unstable bucket-handle medial meniscal tears. Notably, a greater incidence of neurovascular complications has been associated with meniscal repair techniques that employ an accessory skin incision, especially when damage involves the body of the medial meniscus. However, with the operative knee in relative extension, passing inside-out needles anteromedial to the posterior horn and posterior to the semitendinosus tendon and saphenous nerve allows for the needles to exit the posteromedial knee through a "safe zone." Therefore, we reduce iatrogenic damage by avoiding the necessity of a large safety incision while still maintaining suture placement versatility and meniscal fragment stabilization. Thus, the objective of this Technical Note is to outline an efficient technique for treating bucket-handle medial meniscal tears that yields a strong, durable repair while avoiding damage to adjacent neurovascular structures and eliminating the need for a posteromedial safety incision.

Clinical considerations of anatomy and magnetic resonance imaging in pediatric meniscus tear, with imaging-based treatment options

Background

The incidence of meniscal tears in children has been increasing. Early sport specialization, more intense training activity, and increasing participation in competitive sports may have affected to that increasing trend. Diagnosing acute menisci tear in children is based on suggestive clinical and magnetic resonance imaging findings. There are special particulars in immature menisci, due to relatively good vascular supply. Furthermore, growing skeleton makes differences in injury pattern, and a clinician needs to recognize not only meniscus but also potential injuries in growth plates and ligaments, which are usual in connection with pediatric meniscus leasion. Clinical and imaging investigation prior to treatment is crucial, because non-operative care is considerable, to achieve spontaneous healing, especially in peripherial tears of younger children. Second, repair is preferred always as possible, in spite of resection due to high rate of long-term sequelae after partial meniscectomy. High standard preoperative imaging aid in preparing to the meniscus sparing arthroscopic intervention.

Methods

In this current concept article, the clinical considerations of imaging the injured pediatric knee with a suspected meniscus tear and the treatment options by the imaging findings are reviewed.

Level of evidence

level III.

Return to sports after bucket handle medial meniscus tear repair using inside out technique in recreational sports players

The main purpose of our study is to determine the outcomes of bucket handle medial meniscus tears repaired with the inside out technique in recreational sports players, and the return of these to pre-injury sports levels. 41 athletes with medial meniscus bucket handle tear were included in the study. 28 cases were associated with ACL tear while rest were isolated tears. Medial meniscus repair was done exclusively with arthroscopy assisted inside out technique. Lysholm score, IKDC score and Tegner staging were used to evaluate functional status of patients with minimum 1-year follow-up. Data was analyzed using Wilcoxon Matched pairs test, and Friedman test. All patients were examined clinically at regular intervals. Lysholm score and IKDC score showed significant increase in their values. Tegner staging showed no significant change compared to their preinjury game level. On VAS pain scale, there was significant decrease in their pain at regular follow up intervals. 2 patients had re-tears of the repaired medial meniscus. Repairing bucket handle tears of the medial meniscus in recreational sports players with the inside out technique yields good results in terms of clinical and functional outcomes. It successfully allows them to return to sports at 1 year.

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.

Treatment strategies for meniscal lesions: from past to prospective therapeutics

Menisci play an important role in the biomechanics of knee joint function, including loading transmission, joint lubrication, prevention of soft tissue impingement during motion and joint stability. Meniscal repair presents a challenge due to a lack of vascularization that limits the healing capacity of meniscal tissue. In this review, the authors aimed to untangle the available treatment options for repairing meniscal tears. Various surgical procedures have been developed to treat meniscal tears; however, clinical outcomes are limited. Consequently, numerous researchers have focused on different treatments such as the application of exogenous and/or autologous growth factors, scaffolds including tissue-derived matrix, cell-based therapy and miRNA-210. The authors present current and prospective treatment strategies for meniscal lesions.

Inside-Out Approach to Meniscus Repair: Still the Gold Standard?

PURPOSE OF REVIEW

The purpose of this review is to provide an up-to-date summary on the current literature and trends regarding use of the inside-out approach to meniscus repair. Additionally, the paper describes the authors preferred techniques for inside-out meniscus repair utilizing posteromedial and posterolateral exposures.

RECENT FINDINGS

There has been a substantial increase in recent publications regarding meniscus repair. However, comparisons regarding the optimal repair technique have not been conclusive. Despite the recent increase in use of all-inside devices, multiple investigations with short-to-mid-term follow-up have demonstrated similar rates of meniscus healing between inside-out and all-inside repair techniques. Similarly, current literature describes comparable failure rates of around 20%. There are variations in the profile of complications, with all-inside devices having more implant-related complications and inside-out techniques with higher neurovascular injuries. Inside-out meniscus repair is a versatile, cost-effective technique that remains the gold standard for management of most meniscus tear patterns. Through a thoughtful approach, efficient suture retrieval and repair can be performed while protecting critical neurovascular structures. All-inside meniscus repair devices have increased in popularity and surgeon access, but this technique is not without limitations and comparisons to inside-out meniscus repair demonstrates equivocal outcomes.

How to Avoid Iatrogenic Saphenous Nerve Injury During Outside-In or Inside-Out Medial Meniscus Sutures

Medial meniscal sutures using outside-in or inside-out techniques are very popular. Nevertheless, a saphenous nerve entrapment may occur with these techniques. This Technical Note describes a modified outside-in medial meniscus suture without any additional skin incisions. By dissecting the space between the subcutaneous and the capsule, which is performed by grasping and knotting the sutures through the anteromedial portal, iatrogenic saphenous nerve injury is avoided.

Use of an Accessory Anteromedial Portal to Facilitate Repair of Mid-Body Radial Tears of the Lateral Meniscus in Children and Adolescents

Meniscal tears in adolescent patients are commonly treated with repair to preserve meniscal tissue and prevent future degenerative changes. Historically, meniscal tears best suited for repair are acute vertical tears in patients aged <40 years with a normal mechanical axis, >1 cm and <4 cm in size, within the red-red zone, and concurrent with anterior cruciate ligament reconstruction. However, with continued advancements in technology and the development of new techniques, the possibilities and indications for meniscal repair have broadened. This paper presents the use of an accessory medial portal to facilitate the repair of radial tears of the mid-body of the lateral meniscus. Previous techniques described include all-inside, outside-in, and inside-out repairs, but these techniques can be challenging to achieve optimal simultaneous meniscus reduction, visualization, and suture trajectory. In this Technical Note, we describe the use of an inside-out technique, with emphasis on an accessory anteromedial portal to improve visualization and suture trajectory.

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.

Meniscus Repair Techniques

The menisci play a vital role in maintaining knee function and protecting the chondral surfaces. Acute and chronic tears are common injuries among both young athletes and older patients with early degenerative changes. The progression of physiological derangement and chondral injury after meniscus injury and meniscectomy have prompted interest in expanding meniscus repair techniques. Recent literature encourages an attempt at repair in tear patterns previously declared irreparable if the tissue quality allows. The orthopedic surgeon should understand the multitude of techniques available to them and be prepared to combine techniques to optimize the quality of their repair construct. While biological augmentation may show some promising early results, the quality of the current data precludes strong recommendations in their favor.

Meniscal repair: The current state and recent advances in augmentation

Meniscal injuries represent one of the most common orthopedic injuries. The most frequent treatment is partial resection of the meniscus, or meniscectomy, which can affect joint mechanics and health. For this reason, the field has shifted gradually towards suture repair, with the intent of preservation of the tissue. "Save the Meniscus" is now a prolific theme in the field; however, meniscal repair can be challenging and ineffective in many scenarios. The objectives of this review are to present the current state of surgical management of meniscal injuries and to explore current approaches being developed to enhance meniscal repair. Through a systematic literature review, we identified meniscal tear classifications and prevalence, approaches being used to improve meniscal repair, and biological- and material-based systems being developed to promote meniscal healing. We found that biologic augmentation typically aims to improve cellular incorporation to the wound site, vascularization in the inner zones, matrix deposition, and inflammatory relief. Furthermore, materials can be used, both with and without contained biologics, to further support matrix deposition and tear integration, and novel tissue adhesives may provide the mechanical integrity that the meniscus requires. Altogether, evaluation of these approaches in relevant in vitro and in vivo models provides new insights into the mechanisms needed to salvage meniscal tissue, and along with regulatory considerations, may justify translation to the clinic. With the need to restore long-term function to injured menisci, biologists, engineers, and clinicians are developing novel approaches to enhance the future of robust and consistent meniscal reparative techniques.

The Role of the Pie-Crusting Technique of the Medial Collateral Ligament in the Arthroscopic Inside-out Technique for Medial Meniscal Repair With or Without Anterior Cruciate Ligament Reconstruction: A Satisfactory Repair Technique

Purpose

To assess the results of a technique for pie crusting of the medial collateral ligament (MCL) and inside-out medial meniscal repair and perform a comparison with the literature.

Methods

This retrospective study consisted of electronic data collection between 2012 and 2017 with a minimum of 2 years’ follow-up. The inclusion criteria were the presence of difficult medial meniscal tears with joint tightness requiring pie crusting and the presence of acute or chronic tears of zone I or II with or without anterior cruciate ligament reconstruction (ACLR) using hamstring autograft during the same session. The primary outcome of the study was the achievement of good results with the aforementioned technique. There was no control group. All patients underwent assessments at 1, 2, and 6 months in outpatient clinics. At 6 months, the Lysholm knee score was calculated. For statistical analysis, the Social Science Statistics online program was used to perform descriptive analysis and assess any associations between the variables.

Results

This study included 53 patients from a single surgeon’s practice; of these patients, 31 underwent additional ACLR using hamstring autograft during the same session. The mean age was 29.43 years (range, 14-49 years), and the mean increase in the medial joint space width was 3.21 mm (range, 2-5 mm) with pie crusting. At 6 months, the average Lysholm score was 93 (range, 67-100) and the average visual analog scale score was 0.8 (range, 0-4). There was no meaningful association between age, tear pattern, chronicity of tear, joint space width obtained after pie crusting, and associated anterior cruciate ligament tear. Patients returned to their daily activity level at 4.5 months on average and returned to sporting activities at 7.4 months on average. Saphenous nerve symptoms were observed in 5 patients, but no infection or instability was documented in the follow-up period.

Conclusions

In this study, we obtained good outcomes using arthroscopic inside-out medial meniscal repair combined with pie crusting for the release of the MCL, with or without ACLR.

Level of Evidence

Level IV, therapeutic case series.

Inside-out Medial Meniscal Repair: Improved Surgical Exposure With a Sub-semimembranosus Approach

Inside-out meniscal repair is considered the gold standard for reparable tears of the medial and lateral menisci despite the recent popularity of all-inside devices. Accurate suture passage is required to perform a stable repair as well as to prevent inadvertent neurovascular injury from the suture needles. Placement of a deep soft-tissue retractor is necessary to identify and retrieve these needles prior to tying the sutures. Several authors have recommended placement of this retractor in the interval anterior to the gastrocnemius muscle belly and above the semimembranosus tendon. However, we have noted that the needles often pass distal to the retractor when it is placed in this interval owing to the reorientation of the joint line that occurs with the knee in a relatively extended position during suture placement. We describe a modified technique in which the retractor is placed inferior to the semimembranosus, which puts it directly in line with the needles' trajectory. This modification makes inside-out medial meniscal repair safer and more efficient.

Hybrid Inside-Out-Outside-In Meniscal Repair Through a Small Skin Incision

Although the updated generation of all-inside devices for meniscal repair is more convenient to deploy and can provide comparable clinical outcomes with those of the inside-out procedure, the latter is still a very useful technique, giving many advantages over the former. The critical drawback of the conventional inside-out technique is the need for preparation of the accessory incision to prevent the risk of soft-tissue entrapment and neurovascular injury while retrieving the exiting meniscal needles, especially at the posterior corner of the knee. To minimize the space volume of the incision, a small, bluntly dissected track guided by the first exiting meniscal needle is sufficient in our hybrid inside-out-outside-in technique. The guiding cannula for the first meniscal needle passage is a commercial inside-out device, whereas the guiding cannula for retrieval in the subsequent meniscal needle passages is a spinal needle applied in an outside-in manner via the small track. Subsequent meniscal needles can be inserted in an inside-out or outside-in manner according to the design of the suture construct.

Inside-Out Bucket-Handle Meniscus Repair With a Single-Handed Self-Advancing Zone-Specific Meniscus Repair Device

Meniscus tears are among the most common knee injuries in the general population and often are treated arthroscopically with a meniscus repair. Of the various meniscus repair techniques available, the inside-out meniscus tear is considered the gold standard due to its versatility and good clinical outcomes. The purpose of this Technical Note and accompanying video is to describe an inside-out bucket-handle meniscus repair using a single handed, self-advancing meniscus repair device with an interchangeable zone-specific multicannula system to decrease the technical difficulty and operative time of the repair.

Epidemiology, Injury Patterns, and Treatment of Meniscal Tears in Pediatric Patients: A 16-Year Experience of a Single Center

Background:

Meniscal injuries in children continue to increase, which may be attributable to increasing levels of athletic participation and may be associated with additional injuries or need for additional surgeries.

Purpose:

To better understand the patterns of pediatric meniscal injuries by analyzing tear location, morphologic features, and associated injury patterns over a 16-year period.

Study Design:

Case series; Level of evidence, 4.

Methods:

Pediatric patients were identified and were included in the study if age at the time of initial surgery for meniscal tear was between 5 and 14 years for female patients and 5 and 16 years for male patients. Patients were observed until age 18, and any subsequent surgeries were noted. Demographic factors, tear type and location, associated injuries, and treatment type were analyzed.

Results:

Mean patient age at surgery was 13.3 years, and 37% of patients were female. A total of 1040 arthroscopic meniscal surgeries in 880 pediatric patients were evaluated. There were 160 reoperations in 138 patients, representing a reoperation rate of 15%. These included 98 reoperations on the ipsilateral knee in 88 patients and 62 operations for injuries to the contralateral knee in 50 patients; 53% of surgeries were meniscal repair, as opposed to partial meniscectomy, and the most common technique was an all-inside repair (91%). Significant differences were identified between male and female patients. Male patients were more likely to have lateral meniscus (74% vs 65%), posterior horn (71% vs 60%), peripheral (45% vs 30%), and vertical tears (31% vs 21%); concomitant ACL injury (50% vs 40%); and an associated osteochondritis dissecans lesion (7% vs 4%). Female patients were more likely to have medial meniscus (24% vs 17%), anterior horn (25% vs 15%), and degenerative tears (34% vs 26%); discoid meniscus (33% vs 24%); and isolated meniscal tears (47% vs 33%).

Conclusion:

This evaluation of a large series of patients has helped characterize injury patterns associated with pediatric meniscal surgeries. Most meniscal tears were repaired (53%) and were associated with additional injuries (62%), especially anterior cruciate ligament injuries (48%). More than 25% of patients had a discoid meniscus. Injury patterns differed significantly between male and female patients.

Collagen Type I: A Versatile Biomaterial

Collagen type I is the most abundant matrix protein in the human body and is highly demanded in tissue engineering, regenerative medicine, and pharmaceutical applications. To meet the uprising demand in biomedical applications, collagen type I has been isolated from mammalians (bovine, porcine, goat and rat) and non-mammalians (fish, amphibian, and sea plant) source using various extraction techniques. Recent advancement enables fabrication of collagen scaffolds in multiple forms such as film, sponge, and hydrogel, with or without other biomaterials. The scaffolds are extensively used to develop tissue substitutes in regenerating or repairing diseased or damaged tissues. The 3D scaffolds are also used to develop in vitro model and as a vehicle for delivering drugs or active compounds.

No safe zone: The anatomy of the saphenous nerve and its posteromedial branches

BACKGROUND

Following a case of medial meniscal repair via an inside-out repair, a patient developed acute postoperative electric shock-like paresthesias of the proximal medial calf with any knee flexion beyond 80°. Open saphenous nerve exploration revealed entrapment by suture material of an unnamed branch off the sartorial branch of the saphenous nerve. Symptoms resolved immediately with release. The objective of the study was to perform a cadaveric study to examine the existence and frequency of these previously under-reported branches of the sartorial branch of the saphenous nerve.

METHODS

In 16 knees from eight fresh, matched whole cadavers, the medial structures of the knee were exposed, reproducible anatomical structures were identified, and previously under-described posteromedial branches of the sartorial nerve were identified and measured in relation to surrounding structures and the joint line.

RESULTS

The saphenous nerve, its sartorial and infrapatellar branches, and its posteromedial branches were identified in all specimens. The sartorial nerve divided from the saphenous nerve an average of 4.8 cm proximal to the medial femoral epicondyle. Between one and four further posteromedial branches off the sartorial nerve were identified. These branches formed at a range of 5.3 cm proximal to 3.0 cm distal to the joint line.

CONCLUSIONS

This cadaveric study establishes the consistent presence of a posteromedial branch off the sartorial nerve. It was consistently located near the posteromedial joint line. These branches are at risk for injury during medial meniscus repairs due to entrapment by suture materials, or during other surgical procedures near the posteromedial aspect of the knee.

Popliteal neurovascular bundle is safe during inside-out repair of medial meniscus without a safety incision

PURPOSE

There is a theoretical risk of injury to neurovascular structures during inside-out meniscal repair without a safety incision, although there are limited studies assessing this risk. This simulation study on archival MRI films was performed to assess the risk for the popliteal neurovascular bundle and the peroneal nerve during passage of needles for inside-out meniscus repair without a "safety incision", thereby defining a "safe zone" of the menisci that can be safely repaired using this technique.

METHODS

Archival MRI scans (n = 50) were retrieved and axial sections through the menisci were used for simulation. The needle passage was simulated for different points on the posterior horn and body of lateral and medial menisci at "half-hour" intervals using clock method (15° intervals) with three different portals and two different needle cannulas, resulting in six different scenarios of needle passage for each point on the meniscus. The distance of the needle in each scenario was measured from popliteal vessels (n = 50) and peroneal nerve (n = 10). The value "mean-3SD" was calculated for positive means and "Mean + 3SD" was calculated if the mean was negative. An additional 2 mm was defined as "safe distance". Thus, simulation models in which the mean - 3SD was less than 2 mm (or mean + 3SD was greater than - 2 mm for negative means) were labelled as "unsafe".

RESULTS

Needle passage through medial meniscus at and medial to 1 o'clock position for a right knee (or 11 o'clock position for a left knee) was safe, irrespective of the portal and needle type. For the lateral meniscus, only the equatorial region was found to be safe with this method.

CONCLUSIONS

The popliteal neurovascular bundle is safe during the inside-out medial meniscal repair without a safety incision. For the terminal-most part of the posterior horn, the AM portal and the straight cannula should be avoided. However, this method without safety incision cannot be recommended for lateral meniscus because of the risk to the popliteal vessels and the peroneal nerve. Instead, the inside-out method with a safety incision, or an all-inside method should be used for lateral meniscus.

LEVEL OF EVIDENCE

III.

Meniscal allograft transplantation using a novel all-arthroscopic technique with specifically designed instrumentation

The present study describes a novel all-arthroscopic technique for medial and lateral meniscal allograft transplantation (MAT). Surgical instruments were specifically designed to assist in the all-arthroscopic approach for MAT. The bone plug attachment technique, either the arthroscopic-assisted or all-arthroscopic approach, attaches bone plugs to the anterior and posterior horns. In the present study, two sets of surgical implements were designed: One to produce bone plugs of predefined sizes in the anterior and posterior horns of the allograft meniscus (bone plug implements) and a second to create bone tunnels in the receptor tibial plateau to hold the bone plugs (bone tunnel implements). The present study demonstrated that an all-arthroscopic approach to MAT was feasible. Furthermore, the specifically designed surgical instruments allowed for consistent preparation of grafts and recipient tissues, contributing to a standardized approach to MAT. The present findings indicate that an all-arthroscopic approach to MAT may be achievable. They also provide the incentive for future clinical studies to directly compare the outcomes and to initiate the standardization of the procedure to optimize MAT and maximize patient outcomes and quality of life.

Multiple hybrid sutures of bucket handle injury on the lateral and medial meniscus of the knee

The objective of the study is to show possibilities of several combinations of suture techniques in a rare bicompartmental bucket handle injury. According to specific injury characteristics, combined suturing techniques were used. The option for different meniscal suture techniques in the two knee compartments allowed the patient, after completing the treatment, to return to his activities with a preserved meniscus. Although meniscectomy continues to be a chosen technique in bucket handle injury, we attempted to show a case of bicompartmental meniscal suture with different techniques. In this, which could be a case of rapid resolution and quick return to activities with bicompartmental meniscectomy, we chose to preserve the menisci with more complex techniques and longer rehabilitation, believing that the preservation of this structure could be extremely valuable in the long term.

Meniscal Preservation is Important for the Knee Joint

Native joint preservation has gained importance in recent years. This is mostly to find solutions for limitations of arthroplasty. In the knee joint, the menisci perform critical functions, adding stability during range of motion and efficiently transferring load across the tibiofemoral articulation while protecting the cartilage. The menisci are the most common injury seen by orthopedicians, especially in the younger active patients. Advances in technology and our knowledge on functioning of the knee joint have made meniscus repair an important mode of treatment. This review summarizes the various techniques of meniscus tear repair and also describes biological enhancements of healing.

Inside-Out Repair of Meniscal Ramp Lesions

Meniscal ramp lesions have been reported to be present in 9% to 17% of patients undergoing anterior cruciate ligament reconstruction. Detection at the time of arthroscopy can be accomplished based upon clinical suspicion and careful evaluation without the use of an accessory posteromedial portal. Options for surgical treatment include arthroscopic repair using an all-inside or inside-out technique. The purpose of this Technical Note is to detail our arthroscopic inside-out repair technique for meniscal ramp lesions.

Horizontal Cleavage Meniscus Tear Treated With All-inside Circumferential Compression Stitches

Horizontal cleavage meniscus tears are a common orthopedic injury often treated with partial or total meniscectomy versus repair. This Technical Note presents a technique for all-inside repair with uniform compression of the superior and inferior leaflets by placement of multiple circumferential compression stitches using an all-inside self-retrieving suture passing device. The currently described technique provides several advantages for all-inside repair of a horizontal cleavage tear: (1) eliminates the need for a posterior incision, (2) minimizes the risk of neurovascular injury, (3) uses standard arthroscopy portals (or small modifications), and (4) requires only a single suture deployment with a self-retrieving device for each circumferential compression stitch. The resulting circumferential stitch provides uniform compression to the superior and inferior leaflets, promoting meniscal healing. This configuration has been shown to have the highest load to failure of all repair patterns.

An Overview of Scaffold Design and Fabrication Technology for Engineered Knee Meniscus

Current surgical treatments for meniscal tears suffer from subsequent degeneration of knee joints, limited donor organs and inconsistent post-treatment results. Three clinical scaffolds (Menaflex CMI, Actifit® scaffold and NUsurface® Meniscus Implant) are available on the market, but additional data are needed to properly evaluate their safety and effectiveness. Thus, many scaffold-based research activities have been done to develop new materials, structures and fabrication technologies to mimic native meniscus for cell attachment and subsequent tissue development, and restore functionalities of injured meniscus for long-term effects. This study begins with a synopsis of relevant structural features of meniscus and goes on to describe the critical considerations. Promising advances made in the field of meniscal scaffolding technology, in terms of biocompatible materials, fabrication methods, structure design and their impact on mechanical and biological properties are discussed in detail. Among all the scaffolding technologies, additive manufacturing (AM) is very promising because of its ability to precisely control fiber diameter, orientation, and pore network micro-architecture to mimic the native meniscus microenvironment.

Inside-Out Repair for Radial Meniscus Tears

Understanding of meniscal function through basic science, natural history, and biomechanics has highlighted the importance of preserving the meniscus to maintain normal knee biomechanics. Tears that may alter these biomechanics can contribute to the progressive nature of degenerative joint disease in the knee. Radial tears result in the disruption of the circumferential fibers causing inability of the native meniscus to resist normal hoop stresses, thereby leading to increased focal areas of pressure that cause complications such as early onset arthrosis. In this technical note, we describe our preferred operative technique to repair radial meniscal tears using an arthroscopic inside-out approach with satisfactory clinical outcomes and healing response.

Meniscal Ramp Lesions: Anatomy, Incidence, Diagnosis, and Treatment

Meniscal ramp lesions are more frequently associated with anterior cruciate ligament (ACL) injuries than previously recognized. Some authors suggest that this entity results from disruption of the meniscotibial ligaments of the posterior horn of the medial meniscus, whereas others support the idea that it is created by a tear of the peripheral attachment of the posterior horn of the medial meniscus. Magnetic resonance imaging (MRI) scans have been reported to have a low sensitivity, and consequently, ramp lesions often go undiagnosed. Therefore, to rule out a ramp lesion, an arthroscopic evaluation with probing of the posterior horn of the medial meniscus should be performed. Several treatment options have been reported, including nonsurgical management, inside-out meniscal repair, or all-inside meniscal repair. In cases of isolated ramp lesions, a standard meniscal repair rehabilitation protocol should be followed. However, when a concomitant ACL reconstruction (ACLR) is performed, the rehabilitation should follow the designated ACLR postoperative protocol. The purpose of this article was to review the current literature regarding meniscal ramp lesions and summarize the pertinent anatomy, biomechanics, diagnostic strategies, recommended treatment options, and postoperative protocol.

Inside-Out Meniscal Repair: Medial and Lateral Approach

Preservation of meniscal tissue has been proven to be the best approach in most cases of meniscal tears. Currently available techniques for treating a peripheral meniscal tear include inside-out, outside-in, and all-inside techniques. Each of these techniques present potential advantages and disadvantages. Despite technologic advances in all-inside devices, because of implant-related complications, cost concerns, and device availability, the inside-out technique is still the preferred method among many surgeons. Although the inside-out repair technique is considered more technically demanding and requires additional incisions, it has several advantages such as the possibility for an increased number of sutures, creating a stronger construct, and greater versatility in their placement. This article describes the inside-out meniscal repair technique with its corresponding posterolateral and posteromedial surgical approaches.

Location of the popliteal artery and its relationship with the vascular risk in the suture of the posterior horn of the lateral meniscus

INTRODUCTION

The proximity of the posterior horn of the lateral meniscus to the popliteal artery determines a risk of vascular injury in its suture. The aim of this study is to determine the location of the popliteal artery, and to establish the minimal distance from the posterior wall of the lateral meniscus to the artery, the common peroneal nerve (CPN), and its correlation to other variables.

MATERIAL AND METHODS

A total of 102 magnetic resonance studies were retrospectively reviewed from patients undergoing surgery at our institution. The axial section where the lateral meniscus could be clearly defined was selected, and the measurements were performed.

RESULTS

The artery lay laterally to the midline in 94% of the cases. The minimal mean distance from the posterior wall of the lateral meniscus to the popliteal artery was 1.01cm. (0.32-1.74, SD: 0.304). The minimal mean distance to the CPN was 1.74cm. (0.75-2.87, SD: 0.374). No association was found between the minimal mean distance from the posterior wall to the popliteal artery with the height, weight, BMI, the lateral meniscus diameter, or the tibial plateau diameter. An association was found between the distance from the posterior wall to the CPN with the weight and the BMI.

CONCLUSIONS

The proximity of the posterior horn to the popliteal artery should be considered when performing sutures. This distance is within the recommended depth for all-inside meniscus repair devices. This distance is not related to height, weight, BMI, lateral meniscus nor tibial plateau diameters.