The role of meniscal tissue in joint protection in early osteoarthritis

Alignment factors affecting the medial meniscus extrusion increases the risk of osteoarthritis development

PURPOSE

Varus alignment is known as one of the major causes of medial compartment osteoarthritis (OA). Medial meniscus extrusion also plays a critical role in the in the development of OA. However, studies on the exact relationship between alignment parameters and medial meniscus extrusion are limited. Therefore, this study aimed to investigate this relationship in patients with knee OA.

METHODS

Based on a retrospective analysis of the outpatient magnetic resonance imaging (MRI) database, 190 knees were identified to be examined using weight-bearing, whole-leg radiographs and MRIs within 3 months from the first consultation. Subsequently, various parameters of lower leg alignment were measured, which affected the knee varus in radiographs. Finally, a statistical analysis was performed to assess the relationships between the OA grade, distance of medial meniscus extrusion (MME), and alignment parameters; hip-knee-ankle angle (HKAA), percentage of mechanical axis (% MA), medial proximal tibial angle (MPTA), and joint line convergence angle (JLCA). The subjects were divided according to the presence or absence of MME (Group A: MME distance below 3 mm, Group B: MME distance 3 mm and above) to assess the differences in each alignment parameter correlated with MME distance between the groups.

RESULTS

MME distance significantly increased with OA grade progression. HKAA, % MA, MPTA, and JLCA significantly correlated with medial meniscus extrusion distance (r = - 0.21, - 0.23, - 0.16, 0.3, respectively). Multiple regression analysis of each significant alignment combined with age, sex, and body mass index revealed that HKAA, % MA, MPTA, and JLCA were significant independent factors of MME distance (P = 0.008, 0.0026, 0.011, 0.0001, respectively). These significant findings were reinforced in group B. In contrast, the correlation between alignment parameters and medial meniscus extrusion distance was not significant in group A.

CONCLUSION

Varus alignment factors are related to MME distance especially in extruded meniscus knees, as the OA grade progressed. Therefore, the coexistence of varus alignment and MME can be the risk factors for OA progression. As the low MPTA was an independent alignment factor for generating varus alignment, patients with osteoarthritis of the knee with both, low MPTA and MME could be the appropriate candidates for early intervention by high tibial osteotomy.

LEVEL OF EVIDENCE

III.

Current Trends in Viral Gene Therapy for Human Orthopaedic Regenerative Medicine

Background

Viral vector-based therapeutic gene therapy is a potent strategy to enhance the intrinsic reparative abilities of human orthopaedic tissues. However, clinical application of viral gene transfer remains hindered by detrimental responses in the host against such vectors (immunogenic responses, vector dissemination to nontarget locations). Combining viral gene therapy techniques with tissue engineering procedures may offer strong tools to improve the current systems for applications in vivo.

Methods

The goal of this work is to provide an overview of the most recent systems exploiting biomaterial technologies and therapeutic viral gene transfer in human orthopaedic regenerative medicine.

Results

Integration of tissue engineering platforms with viral gene vectors is an active area of research in orthopaedics as a means to overcome the obstacles precluding effective viral gene therapy.

Conclusions

In light of promising preclinical data that may rapidly expand in a close future, biomaterial-guided viral gene therapy has a strong potential for translation in the field of human orthopaedic regenerative medicine.

Secondary Meniscal Tears in Patients With Anterior Cruciate Ligament Injury: Relationship Among Operative Management, Osteoarthritis, and Arthroplasty at 18-Year Mean Follow-up

BACKGROUND

Anterior cruciate ligament (ACL) injury is one of the most frequent orthopaedic injuries and reasons for time loss in sports and carries significant implications, including posttraumatic osteoarthritis (OA). Instability associated with ACL injury has been linked to the development of secondary meniscal tears (defined as tears that develop after the initial ACL injury). To date, no study has examined secondary meniscal tears after ACL injury and their effect on OA and arthroplasty risk.

PURPOSE

To describe the rates and natural history of secondary meniscal tears after ACL injury and to determine the effect of meniscal tear treatment on the development of OA and conversion to total knee arthroplasty (TKA).

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A geographic database of >500,000 patients was reviewed to identify patients with primary ACL injuries between January 1, 1990, and December 31, 2005. Information was collected with regard to ACL injury treatment, rates/characteristics of the secondary meniscal tears, and outcomes, including development of OA and conversion to TKA. Kaplan-Meier and adjusted multivariate survival analyses were performed to test for the effect of meniscal treatment on survivorship free of OA and TKA.

RESULTS

Of 1398 primary ACL injuries, the overall rate of secondary meniscal tears was 16%. Significantly lower rates of secondary meniscal tears were noted among patients undergoing acute ACL reconstruction within 6 months (7%) as compared with patients with delayed ACL reconstruction (33%, P < .01) and nonoperative ACL management (19%, P < .01). Of the 235 secondary meniscal tears identified (196 patients), 11.5% underwent repair, 73% partial meniscectomy, and 16% were treated nonoperatively. Tears were most often medial in location (77%) and complex in morphology (56% of medial tears, 54% of lateral tears). At the time of final follow-up, no patient undergoing repair of a secondary meniscal tear (0%) underwent TKA, as opposed to 10.9% undergoing meniscectomy and 6.1% receiving nonoperative treatment ( P = .28).

CONCLUSION

Secondary meniscal tears after ACL injury are most common among patients undergoing delayed surgical or nonoperative treatment of their primary ACL injuries. Secondary tears often present as complex tears of the medial meniscus and result in high rates of partial meniscectomy.

Repair Augmentation of Unstable, Complete Vertical Meniscal Tears With Bone Marrow Venting Procedure: A Prospective, Randomized, Double-Blind, Parallel-Group, Placebo-Controlled Study

PURPOSE

To compare the effectiveness and safety of meniscal repair in 2 groups of patients: meniscal repair with biological augmentation using a bone marrow venting procedure (BMVP) of the intercondylar notch versus meniscal repair only.

METHODS

This single-center, prospective, randomized, double-blind, placebo-controlled, parallel-arm study included 40 patients (21 menisci in control, 23 in BMVP group) with complete vertical meniscus tears. Patients underwent all-inside and outside-in meniscal repair and a concomitant BMVP of the intercondylar notch or meniscal repair alone during an index arthroscopy. The primary endpoint was the rate of meniscus healing in the 2 groups assessed during a second-look arthroscopy (at week 35). The secondary endpoints were changes in the International Knee Documentation Committee score, Knee Injury and Osteoarthritis Outcome Score, Western Ontario and McMaster Universities Osteoarthritis Index, and visual analog scale in the 2 groups at 30 months.

RESULTS

After 36 weeks, the meniscus healing rate was significantly higher in the BMVP-treated group than in the control group (100% vs. 76%, P = .0035). Functional outcomes were significantly better 30 months after treatment than at baseline in both groups. The International Knee Documentation Committee, Knee Injury and Osteoarthritis Outcome Score, Western Ontario and McMaster Universities Osteoarthritis Index, and visual analog scale scores were significantly better in the BMVP-treated group than in the control group. No adverse events were reported during the study period.

CONCLUSIONS

Our blinded, prospective, randomized, controlled trial on the role of BMVP augmentation in meniscus repair, indicates that BMVP augmentation results in a significant improvement in the rate of meniscus healing (100% vs. 76%, P = .0035). The risk of adverse events related to augmentation with BMVP of the arthroscopic meniscal repair is very low.

LEVEL OF EVIDENCE

Level I, randomized controlled trial.

Long-term Results After Repair of Isolated Meniscal Tears Among Patients Aged 18 Years and Younger: An 18-Year Follow-up Study

BACKGROUND

Meniscal repair is desirable over resection to prevent postmeniscectomy arthritis, especially among young and active patients. However, long-term data are currently lacking following isolated meniscal repair, particularly in the pediatric population.

PURPOSE/HYPOTHESIS

To report long-term follow-up of isolated meniscal tears treated by meniscal repair in a pediatric and adolescent population and to compare those results with previous midterm follow-up data reported. The authors hypothesized that these patients would have satisfactory function and reoperation rates at long-term follow-up.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Forty-four patients aged ≤18 years undergoing repair of an isolated meniscal tear (without concomitant anterior cruciate ligament injury) between 1990 and 2005 were included. At the time of final follow-up, recurrent tear, reoperations, and International Knee Documentation Committee (IKDC) and Tegner scores were determined. With logistic regression, the overall failure among tear types was calculated. Wilcoxon rank sum analysis were performed to calculate the differences in clinical outcome for different time points, and Spearman coefficients were calculated for Tegner and IKDC with different variables.

RESULTS

At a mean follow-up of 17.6 years (range, 13.1-25.9 years), 32 patients with 33 isolated meniscal repairs (29 male, 3 female) with a mean age of 16.1 years (range, 9.9-18.7 years) at surgery were included in this study. At early follow-up, the overall failure rate was 14 of 33 (42%); complex tears (80%) and bucket-handle tears (47%) had higher overall failure rates when compared with simple tears (18.2%), although only complex tears had a significantly higher failure rate. However, no further failures occurred since midterm follow-up with any tear type. At final follow-up, the mean IKDC score was 92.3, which was significantly increased when compared with preoperative (65.3, P < .0001) and midterm (90.2, P = .01) scores. The mean Tegner score (6.5) was significantly lower than both preoperative (8.3, P < .0001) and midterm (8.4, P < .0001) scores. There was no difference in Tegner or IKDC score for patients with successful versus failed repair.

CONCLUSION

In conclusion, while there was a high early failure rate, this study demonstrated overall good to excellent long-term clinical outcomes after isolated meniscal repair in an adolescent population, even for those requiring reoperation. Early failure and reoperation rates were variable, depending on tear type, with complex multiplanar tears having more failures at short-term follow-up. However, at long-term follow-up, IKDC and Tegner scores were not significantly different for those with complex tears as compared with other tear types.

Meniscal allograft transplantation after meniscectomy: clinical effectiveness and cost-effectiveness

PURPOSE

To assess the clinical effectiveness and cost-effectiveness of meniscal allograft transplantation (MAT) after meniscal injury and subsequent meniscectomy.

METHODS

Systematic review of clinical effectiveness and cost-effectiveness analysis.

RESULTS

There is considerable evidence from observational studies, of improvement in symptoms after meniscal allograft transplantation, but we found only one small pilot trial with a randomised comparison with a control group that received non-surgical care. MAT has not yet been proven to be chondroprotective. Cost-effectiveness analysis is not possible due to a lack of data on the effectiveness of MAT compared to non-surgical care.

CONCLUSION

The benefits of MAT include symptomatic relief and restoration of at least some previous activities, which will be reflected in utility values and hence in quality-adjusted life years, and in the longer term, prevention or delay of osteoarthritis, and avoidance or postponement of some knee replacements, with resulting savings. It is likely to be cost-effective, but this cannot be proven on the basis of present evidence.

LEVEL OF EVIDENCE

IV.

Autologous micro-fragmented adipose tissue for the treatment of diffuse degenerative knee osteoarthritis: an update at 3 year follow-up

BACKGROUND

Conservative therapies for the treatment of knee degenerative processes are used before resorting to surgery; nonetheless, they may offer only short-term benefits. Encouraging preliminary results have been reported using mesenchymal stem cells (MSCs), either alone or in association with surgery. Among the many sources, adipose tissue has created a huge interest, because of its anti-inflammatory and regenerative properties ascribed to the cells of its stromal vascular fraction. We previously reported the safety and feasibility of autologous micro-fragmented adipose tissue as adjuvant for the surgical treatment of diffuse degenerative chondral lesions at 1 year. Here we present the outcomes of the same cohort of patients evaluated at 3 year follow-up. Micro-fragmented adipose tissue was obtained using a minimal manipulation technique in a closed system. The safety of the procedure was evaluated by recording type and incidence of any adverse event. The clinical outcomes were determined using the KOOS, IKDC-subjective, Tegner Lysholm Knee, and VAS pain scales taken pre-operatively and at 12 and 36 months follow-up.

FINDINGS

No adverse events, lipodystrophy cases at the harvesting site nor atypical inflammatory reactions at the joint level were reported. Of the 30 patients previously treated, one was lost, and seven received additional treatments in the period of observation. On average, the 22 patients that had no other treatments in the 3-year period showed that the results observed at 1 year were maintained. Moreover, 41, 55, 55 and 64% of the patients improved with respect to the 1-year follow-up in the Tegner Lysholm Knee, VAS, IKDC-subjective and total KOOS, respectively.

CONCLUSION

Our results point to autologous and micro-fragmented adipose tissue injection as an innovative and safe approach for the management of diffuse degenerative knee chondropathy in the mid-term. The procedure is simple, affordable, minimally invasive, and compliant with the regulatory panorama.

Surgical Feasibility of a One-Stage Cell-Based Arthroscopic Procedure for Meniscus Regeneration: A Cadaveric Study

IMPACT STATEMENT

Meniscus injury remains the most common indication for orthopedic surgery, but loss of functioning meniscus tissue is strongly correlated with development of early osteoarthritis. However, current clinical options for tissue engineering of the meniscus are limited. This study demonstrates the feasibility of combining human meniscus cells with mesenchymal stromal cells to enhance a meniscus scaffold for meniscus regeneration in a one-stage solution for partial meniscal deficiency.

Arthroscopic meniscal surgery versus conservative management in patients aged 40 years and older: a meta-analysis

INTRODUCTION

The efficacy of arthroscopic meniscus surgery in old aged patients remains controversial. The purpose of the present study was to review published studies comparing arthroscopic meniscal surgery with conservative management to treat meniscal injuries in patients 40 years of age and older.

MATERIALS AND METHODS

Several electronic databases were queried for articles published until July 2017 that evaluated outcomes of arthroscopic meniscal surgery in patients aged 40 years and older. Data searches, extraction, analysis, and quality assessment were performed according to the Cochrane Collaboration guidelines, and the clinical outcomes were evaluated using various outcome values. The results are presented as the standard mean difference (SMD) for continuous outcomes with 95% confidence intervals (CIs).

RESULTS

Nine randomized controlled trials (RCTs) were included. There were no significant differences in clinical outcomes such as relief in knee pain (SMD = 0.01, 95% CIs = - 0.15 to 0.18, I² = 38%) and improved knee function (SMD = 0.01, 95% CIs = - 0.19 to 0.21, I² = 57%) between arthroscopic meniscal surgery and conservative management for degenerative meniscal tears.

CONCLUSIONS

The efficacy of arthroscopic surgery was not superior to conservative management in this type of patients. Therefore, arthroscopic meniscal surgery should not be recommended as a first choice of treatment for degenerative meniscal tears. In patients over 40 years of age, arthroscopic surgery should be cautiously considered for degenerative meniscal tears and only when there has not been a satisfactory response to conservative management.

The effects of graft shrinkage and extrusion on early clinical outcomes after meniscal allograft transplantation

BACKGROUND

Graft shrinkage or radial extrusion is a reported complication after meniscus allograft transplantation (MAT). Whether shrinkage or extrusion progress after surgery and whether they are associated with the clinical outcome of MAT remain debatable. In this study, graft shrinkage and extrusion were measured in the coronal and sagittal planes using serial postoperative magnetic resonance imaging (MRI). The purpose of this study was to evaluate if graft shrinkage or extrusion is correlated to the clinical outcome of MAT.

METHODS

MRIs acquired at 3 and 12 months postoperatively in 30 patients (21 men and 9 women) who underwent MAT (6 medial and 24 lateral menisci) from 2010 to 2016 were analyzed. Two orthopedic surgeons and two musculoskeletal specialized radiologists each performed the MRI measurements. Allograft shrinkage was measured by the width and thickness of the graft at the coronal and sagittal planes. To determine the graft extrusion, distances between the proximal tibia cartilage margin and the extruded graft margin were measured in both coronal (either lateral or medial) and sagittal (both anterior and posterior) plane and relative percentage of extrusion (RPE) were calculated. Subjective International Knee Documentation Committee (IKDC) scores at 12 months were evaluated as a clinical outcome measurement, and correlations between shrinkage or extrusion of allograft and IKDC score were analyzed.

RESULTS

In the coronal plane, radial RPE averaged 43.6% at postoperative 3 months, but there was no significant progression of extrusion at 12 months (average 42.0%) (P = 0.728). In the sagittal plane, there were no significant progressions of anterior and posterior RPE (P = 0.487 and 0.166, respectively) between postoperative 3 and 12 months. Shrinkage was calculated by multiplying the width and height of the three sections and summing these values. There was no significant progression of shrinkage between postoperative 3 and 12 months (P = 0.150). RPE in the radial (R = 0.147, P = 0.525), anterior (R = 0.249, P = 0.264), and posterior (R = 0.230, P = 0.315) directions and shrinkage (R = 0.176, P = 0.435) were not correlated to IKDC score at postoperative 12 months.

CONCLUSIONS

In the coronal and sagittal planes, extrusion and shrinkage did not progress from 3 months to 1 year. Extrusion and shrinkage had no correlation with early clinical outcomes. This finding suggests that graft extrusion or shrinkage may be not a great concern especially in early postoperative period of MAT, and multiple, serial MRI may be not necessary.

Lateral Knee Compartment Portals: A Cadaveric Study Defining a Posterolateral Viewing Safety Zone

PURPOSE

This study attempted to define a reproducible "safe zone" based on extra- and intra-articular knee anatomy for placing one or 2 accessory portals in the lateral tibiofemoral compartment for posterolateral region viewing.

METHODS

Standard portals were created in 10 cadaveric knees to enable posterolateral region arthroscopic lateral tibiofemoral joint compartment viewing. After identifying the lateral knee surface tissue "soft spot," an accessory posterolateral portal (A) was created using an 18-gauge spinal needle and 4-mm cannula under direct visualization of a 70° arthroscope through the anteromedial portal. A second accessory portal (B) was then created 1 cm posterior and 1 cm superior to portal A. Accessory portal locations were measured relative to capsular fold and popliteus tendon locations. Distances from the peroneal nerve, lateral collateral ligament, popliteus tendon, and the biceps tendon were determined. Statistical analysis compared portal location differences from key anatomical structures (P < .05).

RESULTS

Accessory portal A (mean ± 95% confidence interval) was located 8.8 ± 2.7 mm from the popliteus tendon, 11.6 ± 2.7 mm from the lateral collateral ligament (LCL), 26.8 ± 2.3 mm from the peroneal nerve, and 4.9 ± 2.5 mm from the biceps tendon. Accessory portal B was located 17.3 ± 2.8 mm from the popliteus tendon, 20 ± 2.8 mm from the LCL, 30.3 ± 3.3 mm from the peroneal nerve, and 7.0 ± 4.8 mm from the biceps tendon. Accessory portal B was located a greater distance from the LCL and the popliteus tendon than portal A (P < .0001).

CONCLUSIONS

Using intra- and extra-articular anatomic landmarks, both accessory portals could be safely placed in the lateral tibiofemoral joint compartment to enable posterolateral region viewing. Accessory portals used individually or in combination may enable easier posterolateral region viewing for arthroscopic repair of lateral tibiofemoral compartment structures.

CLINICAL RELEVANCE

Lateral tibiofemoral compartment portals can be safely created to enable improved visibility for complex arthroscopic procedures in the posterolateral viewing region.

Meniscal pathologies on MRI correlate with increased bone tracer uptake in SPECT/CT

OBJECTIVES

To assess the relationship of subchondral bone tracer uptake (BTU) on SPECT/CT and meniscal pathologies on MRI in patients with painful knees.

METHODS

Twenty-five patients who had MRI and SPECT/CT within 3 months without knee surgery or grade ≥3 cartilage lesions were prospectively included. Maximum values of each subchondral femorotibial area were quantified and a ratio was calculated in relation to a femoral shaft reference region, which represented the BTU background activity. Meniscal lesions were graded (intact/degeneration/tear) and meniscal extrusion (no/yes) was assessed using MRI by two musculoskeletal radiologists blinded to the SPECT/CT findings. One-tailed Spearman correlations served for statistics (p < 0.05).

RESULTS

Knees with meniscal degeneration or tear showed a significantly higher BTU in the medial femorotibial compartment (p = 0.045) when compared to intact menisci. Meniscal degeneration was associated with an increased BTU in the lateral femorotibial compartment; however, this was not statistically significant (p = 0.143). Patients with an extruded meniscus showed significantly higher BTU compared to a non-extruded meniscus (p < 0.020).

CONCLUSIONS

Medial femorotibial BTU in SPECT/CT was associated with meniscal pathologies. Highest BTU was found in patients with meniscal tears. SPECT/CT appears to be a useful imaging modality to identify patients with overloading or early osteoarthritis.

KEY POINTS

• Meniscal degeneration and tears correlate significantly with increased BTU using SPECT/CT. • Medial meniscus extrusion is associated with an increased BTU in SPECT/CT. • SPECT/CT allows detection of overloading and early osteoarthritis.

Modern treatment of meniscal tears

The complex ultrastructure of the meniscus determines its vital functions for the knee, the lower extremity, and the body.

The most recent concise, reliable, and valid classification system for meniscal tears is the International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine (ISAKOS) Classification, which takes into account the subsequent parameters: tear depth, tear pattern, tear length, tear location/rim width, radial location, location according to the popliteal hiatus, and quality of the meniscal tissue.

It is the orthopaedic surgeon’s responsibility to combine clinical information, radiological images, and clinical experience in an effort to individualize management of meniscal tears, taking into account factors related to the patient and lesion.

Surgeons should strive not to operate in most cases, but to protect, repair or reconstruct, in order to prevent early development of osteoarthritis by restoring the native structure, function, and biomechanics of the meniscus.

Currently, there are three main methods of modern surgical management of meniscus tears: arthroscopic partial meniscectomy; meniscal repair with or without augmentation techniques; and meniscal reconstruction. Meniscus surgery has come a long way from the old slogan, “If it is torn, take it out!” to the currently accepted slogan, “Save the meniscus!” which has guided evolving modern treatment methods for meniscal tears. This last slogan will probably constitute the basis for newer alternative biological treatment methods in the future.

Cite this article: EFORT Open Rev 2018;3 DOI: 10.1302/2058-5241.3.170067.

A Prospective, Randomized, Double-Blind, Parallel-Group, Placebo-Controlled Study Evaluating Meniscal Healing, Clinical Outcomes, and Safety in Patients Undergoing Meniscal Repair of Unstable, Complete Vertical Meniscal Tears (Bucket Handle) Augmented with Platelet-Rich Plasma

OBJECTIVE

The present study aimed to investigate the effectiveness and safety of platelet-rich plasma (PRP) application in arthroscopic repair of complete vertical tear of meniscus located in the red-white zone.

METHODS

This single center, prospective, randomized, double-blind, placebo-controlled, parallel-arm study included 37 patients with complete vertical meniscus tears. Patients received an intrarepair site injection of either PRP or sterile 0.9% saline during an index arthroscopy. The primary endpoint was the rate of meniscus healing in the two groups. The secondary endpoints were changes in the International Knee Documentation Committee (IKDC) score, Knee Injury and Osteoarthritis Outcome Score (KOOS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and analog scale (VAS) in the two groups at 42 months.

RESULTS

After 18 weeks, the meniscus healing rate was significantly higher in the PRP-treated group than in the control group (85% versus 47%, P = 0.048). Functional outcomes were significantly better 42 months after treatment than at baseline in both groups. The IKDC score, WOMAC, and KOOS were significantly better in the PRP-treated group than in the control group. No adverse events were reported during the study period.

CONCLUSIONS

The findings of this study indicate that PRP augmentation in meniscus repair results in improvements in both meniscus healing and functional outcome.

Medial meniscus grafting restores normal tibiofemoral contact pressures

BACKGROUND

Tissue excision in the setting of a meniscal tear has been shown to dramatically increase peak contact stresses in the affected tibiofemoral joint compartment, leading to the development of degenerative changes and osteoarthritis.

PURPOSE/HYPOTHESIS

The current in vitro study utilized a porcine model to evaluate the effectiveness of segmental medial meniscal grafting following partial meniscectomy. The study hypothesis was that the procedure would normalize medial tibofemoral joint compartment pressure magnitudes, areas, and locations relative to an intact meniscus.

STUDY DESIGN

Controlled laboratory study.

METHODS

Using pressure film, medial tibiofemoral joint compartment peak, and mean pressure magnitudes, peak pressure location and peak pressure area were determined using 12 potted, fresh frozen, porcine knee specimens. Data were collected at three different knee flexion angles (90°, 45°, and 0°) for three conditions: intact medial meniscus, following resection of the central third of the medial meniscus, and following segmental medial meniscal grafting. For each condition, the potted femur was positioned horizontally in a bench vise clamp, while a 20 pound (88.96 N) axial compression force was manually applied for a 60 s duration by the primary investigator through the base of the potted tibia using a digital force gauge.

RESULTS

Loss of the central 1/3 of the medial meniscus resulted in significant increases in the mean and peak pressures of the medial tibiofemoral joint compartment and decreased peak pressure area. Segmental meniscal grafting of the central third defect closely recreated the contact pressures and loading areas of the native, intact medial meniscus.

CONCLUSION

From a static, time zero biomechanical perspective, segmental medial meniscus grafting of a partially meniscectomized knee restored mean pressure, peak pressure, and mean peak contact pressure areas of the medial tibiofemoral joint compartment back to levels observed in the intact medial meniscus at different knee flexion angles. In-vivo analysis under dynamic conditions is necessary to verify the healing efficacy and ability of the healed segmental medial meniscal allograft to provide long-term knee joint homeostasis when confronted with dynamic shear, rotatory, and combined, higher magnitude physiologic loading forces.

Reinterventions after dynamic intraligamentary stabilization in primary anterior cruciate ligament repair

BACKGROUND

The goal of this study was to perform an in-depth analysis of the frequency and cause of secondary interventions subsequent to primary anterior cruciate ligament (ACL) repair with dynamic intraligamentary stabilization (DIS).

METHODS

Between July 2009 and June 2014, 455 patients underwent DIS treatment. The minimum follow-up was 21months (mean 28months, range 21-64months).

RESULTS

A total of 215 (48.2%) reinterventions were performed in 190 (42.6%) patients. One-hundred and seventy-six (39.4%) were non-revision reinterventions, and 39 (8.7%) were revision ACL reconstructions. Re-arthroscopies included 26 (5.8%) scar tissue debridements with hardware removal due to range of motion deficits, 14 (3.1%) partial meniscectomies, four (0.9%) meniscal sutures, and four (0.9%) arthroscopies due to crepitation or knee pain. Minor non-revision reinterventions performed under analgosedation consisted of 97 (21.7%) hardware removals, 20 (4.5%) hardware removals with manipulations under anesthesia, and four manipulations under anesthesia alone (0.9%).

CONCLUSIONS

In our study, the revision rate was within the range of published results after ACL reconstructions. In over 90% of patients, the native ACL was preserved with no need for a secondary reconstruction. Most of the non-revision reinterventions were minor and included hardware removals and manipulations under anesthesia. The re-arthroscopy rate was lower than that after ACL reconstruction with fewer secondary meniscal sutures and partial meniscectomies. Early treatment of meniscal tears may be one crucial benefit of ACL repair with DIS.

Clinical Management in Early OA

Knee osteoarthritis affects an important percentage of the population throughout their life. Several factors seem to be related to the development of knee osteoarthritis including genetic predisposition, gender, age, meniscal deficiency, lower limb malalignments, joint instability, cartilage defects, and increasing sports participation. The latter has contributed to a higher prevalence of early onset of knee osteoarthritis at younger ages with this active population demanding more consistent and durable outcomes. The diagnosis is complex and the common signs and symptoms are often cloaked at these early stages. Classification systems have been developed and are based on the presence of knee pain and radiographic findings coupled with magnetic resonance or arthroscopic evidence of early joint degeneration. Nonsurgical treatment is often the first-line option and is mainly based on daily life adaptations, weight loss, and exercise, with pharmacological agents having only a symptomatic role. Surgical treatment shows positive results in relieving the joint symptomatology, increasing the knee function and delaying the development to further degenerative stages. Biologic therapies are an emerging field showing early promising results; however, further high-level research is required.

Temporal development of near-native functional properties and correlations with qMRI in self-assembling fibrocartilage treated with exogenous lysyl oxidase homolog 2

Advances in cartilage tissue engineering have led to constructs with mechanical integrity and biochemical composition increasingly resembling that of native tissues. In particular, collagen cross-linking with lysyl oxidase has been used to significantly enhance the mechanical properties of engineered neotissues. In this study, development of collagen cross-links over time, and correlations with tensile properties, were examined in self-assembling neotissues. Additionally, quantitative MRI metrics were examined in relation to construct mechanical properties as well as pyridinoline cross-link content and other engineered tissue components. Scaffold-free meniscus fibrocartilage was cultured in the presence of exogenous lysyl oxidase, and assessed at multiple time points over 8weeks starting from the first week of culture. Engineered constructs demonstrated a 9.9-fold increase in pyridinoline content, reaching 77% of native tissue values, after 8weeks of culture. Additionally, engineered tissues reached 66% of the Young's modulus in the radial direction of native tissues. Further, collagen cross-links were found to correlate with tensile properties, contributing 67% of the tensile strength of engineered neocartilages. Finally, examination of quantitative MRI metrics revealed several correlations with mechanical and biochemical properties of engineered constructs. This study displays the importance of culture duration for collagen cross-link formation, and demonstrates the potential of quantitative MRI in investigating properties of engineered cartilages.

STATEMENT OF SIGNIFICANCE

This is the first study to demonstrate near-native cross-link content in an engineered tissue, and the first study to quantify pyridinoline cross-link development over time in a self-assembling tissue. Additionally, this work shows the relative contributions of collagen and pyridinoline to the tensile properties of collagenous tissue for the first time. Furthermore, this is the first investigation to identify a relationship between qMRI metrics and the pyridinoline cross-link content of an engineered collagenous tissue.

Meniscal Repair With Fibrin Clot Augmentation

Meniscal injuries and meniscal loss are associated with changes in knee kinematics and loading, ultimately leading to poor functional outcomes and increased risk of progression to osteoarthritis. Biomechanical studies have shown restored knee function, and clinical studies have reported improved outcomes and decreased risk of osteoarthritis after meniscal repair. This has led orthopaedic surgeons to try and save the meniscus by repair whenever possible, as shown by increasing incidence of meniscal repair surgeries. Historically, meniscal lesions, particularly those greater in size and located in the white-white region of the meniscus, have been shown to have poor healing. In recent years, there has been an increasing interest in the use of biologic agents to help stimulate and expedite healing in traditionally more avascular tissue. Preliminary results for biologic therapeutic agents, such as platelet rich plasma and bone marrow aspirate concentrate, have been encouraging. However, these options are more demanding in regard to time, financial burden, resources, and regulations than some more classic agents such as fibrin clots. Fibrin clot is readily available, easy to use, affordable, and minimally invasive. This Technical Note describes a step-by-step and reproducible technique for harvesting, preparation, and using a fibrin clot to augment healing of meniscal repairs.

Autologous mesenchymal stem cells or meniscal cells: what is the best cell source for regenerative meniscus treatment in an early osteoarthritis situation?

Background

Treatment of meniscus tears within the avascular region represents a significant challenge, particularly in a situation of early osteoarthritis. Cell-based tissue engineering approaches have shown promising results. However, studies have not found a consensus on the appropriate autologous cell source in a clinical situation, specifically in a challenging degenerative environment. The present study sought to evaluate the appropriate cell source for autologous meniscal repair in a demanding setting of early osteoarthritis.

Methods

A rabbit model was used to test autologous meniscal repair. Bone marrow and medial menisci were harvested 4 weeks prior to surgery. Bone marrow-derived mesenchymal stem cells (MSCs) and meniscal cells were isolated, expanded, and seeded onto collagen-hyaluronan scaffolds before implantation. A punch defect model was performed on the lateral meniscus and then a cell-seeded scaffold was press-fit into the defect. Following 6 or 12 weeks, gross joint morphology and OARSI grade were assessed, and menisci were harvested for macroscopic, histological, and immunohistochemical evaluation using a validated meniscus scoring system. In conjunction, human meniscal cells isolated from non-repairable bucket handle tears and human MSCs were expanded and, using the pellet culture model, assessed for their meniscus-like potential in a translational setting through collagen type I and II immunostaining, collagen type II enzyme-linked immunosorbent assay (ELISA), and gene expression analysis.

Results

After resections of the medial menisci, all knees showed early osteoarthritic changes (average OARSI grade 3.1). However, successful repair of meniscus punch defects was performed using either meniscal cells or MSCs. Gross joint assessment demonstrated donor site morbidity for meniscal cell treatment. Furthermore, human MSCs had significantly increased collagen type II gene expression and production compared to meniscal cells (p < 0.05).

Conclusions

The regenerative potential of the meniscus by an autologous cell-based tissue engineering approach was shown even in a challenging setting of early osteoarthritis. Autologous MSCs and meniscal cells were found to have improved meniscal healing in an animal model, thus demonstrating their feasibility in a clinical setting. However, donor site morbidity, reduced availability, and reduced chondrogenic differentiation of human meniscal cells from debris of meniscal tears favors autologous MSCs for clinical use for cell-based meniscus regeneration.

Arthroscopic all-inside ramp lesion repair using the posterolateral transseptal portal view

PURPOSE

The purpose of this study was to evaluate and describe the clinical results and outcomes of a novel method for all-inside suture repair of medial meniscus ramp lesions through posteromedial and posterolateral transseptal portals during anterior cruciate ligament (ACL) reconstruction. Further, this investigation compared the posterolateral view to the notch view for diagnosis and repair.

METHODS

Between 2011 and 2014, 166 patients had ramp lesions concomitantly with ACL injury; 128 patients (107 men and 21 women) were enrolled in the study after qualification. All patients underwent repair of the posterior horn ramp lesion of the medial meniscus, using a suture hook device with PDS No. 1 through a posteromedial portal while viewing from the posterolateral transseptal portal during ACL reconstruction, with a minimum of a 2-year follow-up.

RESULTS

Patients were followed up for a minimum of 2 years (range 24-47 months). Their average Lysholm score increased from 61.7 ± 3.2 preoperatively to 87.8 ± 3.9 at last follow-up (p < 0.001). Moreover, their average IKDC scores also improved from 53.6 ± 2.1 (pre-op) to 82.1 ± 3.5 (at last follow-up) (p < 0.001). The peroneal nerve and the popliteal neurovascular bundle were not damaged in any of the patients.

CONCLUSION

This study provides evidence that the posterolateral transseptal technique protects neurovascular structures. This technique may be used safely and easily for repair of the posterior horn ramp lesion of the medial meniscus during ACL reconstruction.

LEVEL OF EVIDENCE

IV.