Long-term follow-up of meniscectomy in athletes. A prospective longitudinal study

Alteration in ACL loading after total and partial medial meniscectomy

Anterior cruciate ligament (ACL) injuries are often caused by high impact loadings during competitive sports but may also happen during regular daily activities due to tissue degeneration or altered mechanics after a previous knee injury or surgery such as meniscectomy. Most existing research on ACL injury has focused on impact loading scenarios or the consequence of ACL injury on meniscus. The objective of the present study was to investigate the effects of varying degrees of medial meniscectomy on the mechanics of intact ACL by performing a poromechanical finite element analysis under moderate creep loadings. Four clinical scenarios with 25%, 50%, 75% and total medial meniscectomy were compared with the intact knee finite element model. Our results suggested that different medial meniscal resections may increase, at different extents, the knee laxity and peak tensile stress in the ACL, potentially leading to collagen fiber fatigue tearing and altered mechanobiology under normal joint loadings. Interestingly, the ACL stress actually increased during early knee creep (~ 3 min) before it reached an equilibrium. In addition, meniscectomy accelerated ACL stress reduction during knee creep, transferred more loading to tibial cartilage, increased contact pressure, and shifted the contact center posteriorly. This study may contribute to a better understanding of the interaction of meniscectomy and ACL integrity during daily loadings.

High tibial osteotomy is equally effective for varus malaligned knees with either virgin or wrecked medial meniscus: An age and gender-matched secondary analysis of a Francophone Arthroscopy Society Symposium

INTRODUCTION

Despite the growing concept of meniscal preservation, partial meniscectomy could be the definitive procedure in specific scenarios. And total meniscectomy was once before a frequent procedure, with current sequelae of degenerate knees. High tibial osteotomy (HTO) is an effective treatment for patients suffering from unicompartmental degenerative changes, and substantial deformities. However, it is yet to be answered, whether HTO is similarly effective in both post-meniscectomy knees and knees with not previously operated meniscus.

HYPOTHESIS

Outcomes of HTO is similar with or without previous history of total or subtotal meniscectomy.

METHODS

This study compared the clinical and radiological outcomes of 41 patients who received HTO and had no previous history of surgery in the ipsilateral knee (group I), and 41 age, and gender-matched patients who had meniscectomy surgery in the ipsilateral knee (group II). Preoperatively and postoperatively, all patients were clinically evaluated; the visual analogue scale scores, Tegner activity score, and the Western Ontario and Macmaster University scores were reported. Radiographically, osteoarthritis grade and pre- and postoperative parameters were reported, including hip-knee-ankle angle, femoral mechanical angle, medial proximal tibial angle, joint line convergence angle, proximal posterior tibial angle, and limb length discrepancy. Perioperative details and complications were reported.

RESULTS

A total of 82 patients were included; group I (n=41) and group II (n=41). The mean age was 51.18±8.64 (27-68) and 90.24% were male. The duration since the onset of symptoms was longer in group II vs. group I, 43.34±41.03 versus 38.07±36.11months respectively. No significant differences in the clinical evaluation between the two groups with a greater proportion of patients demonstrating moderate degenerative changes. Similar preoperative and postoperative radiographic parameters were reported, in group I, Δ HKA was 7.19±4.14 versus 7.65±3.16 in group II. Preoperative pain VAS scores were slightly higher in group II vs. group I, 79.23±26.35 vs. 76.31±24.45, respectively. However, postoperatively, the pain scores significantly improved in group I vs. group II, 22.84±3.65 vs. 41.69±17.33, respectively. Tegner activity scores and WOMAC scores were comparable between both groups preoperatively and postoperatively. Only the WOMAC function scores were better in group I when compared to group II, 26.13±25.84 versus 20.01±17.98. All patients returned to work at an average of 0.82±0.38months.

CONCLUSION

Knee preservation with high tibial osteotomy is equally effective in managing unicompartmental degenerative changes in varus malaligned knees with either no previous history of meniscal surgeries or where a meniscal sacrifice was inevitable, either with subtotal or total meniscectomy.

LEVEL OF EVIDENCE

III, retrospective case-control study.

Meniscal Allograft Transplantation Concomitant With Cartilage Repair for Symptomatic Lateral Meniscus-Deficient Knees With Over Two Years of Follow-up

Background and objective The treatment for symptomatic meniscus-deficient knees with cartilage defects remains challenging on account of insufficient meniscal substitutes. One solution for this might involve combining meniscal allograft transplantation (MAT) and cartilage repair. In this study, we aimed to analyze the effectiveness and safety of MAT concomitant with cartilage repair for symptomatic lateral meniscus-deficient knees in a setting with limited availability of meniscal transplants in Japan. Methods Nine patients who underwent MAT concomitant with osteochondral transplantation (five) and/or autologous chondrocyte implantations (seven) were followed up for at least two years (mean: 51.2 months, range: 24-84 months). Their demographic data and other characteristics were as follows - mean age: 51.7 years, range: 36-67 years; men/women: 4/5; cause: trauma/discoid meniscus: 8/1; cartilage defect size: mean: 6.7 cm2/knee, range: 1.0-11.3. The effectiveness and safety were evaluated clinically by using the Lysholm Knee Scoring Scale (LKSS) and Japanese Orthopaedic Association (JOA) knee score, physical examination, X-rays, and MRI preoperatively and at one, 12, and 24 months after the implantation. Differences between the variables were analyzed using the Friedman test and Scheffe's multiple comparisons. Results The median LKSS and JOA scores significantly improved from 70 points (range: 21-80) and 35 (25-45) preoperatively to 86.5 (65-98) and 87.5 (80-95) at 24 months after surgery, respectively (p<0.001, p=0.0013). The range of motion (ROM), femorotibial angle, and the lateral joint space showed no significant changes. However, lateral meniscal extrusions (LMEs) increased by 3.0 mm (range: 0-6.3 mm) at one month postoperatively and remained unchanged until two years postoperatively. Treatment failure occurred in one case, which was revised by total knee arthroplasty (TKA) at 18 months postoperatively. Additional surgeries were needed in some cases: lateral meniscal tear (three cases), contracture (two cases), and patellar instability (one case). However, neither infection nor allergic reaction was observed in the blood exams. Conclusions Although MAT concomitant with cartilage repair showed good clinical outcomes, half of the cases needed additional surgeries. Based on our findings, this technique should be adopted only in select cases and performed by a handful of highly experienced surgeons.

Minimum 10-Year Clinical Outcomes and Survivorship of Meniscal Allograft Transplantation With Fresh-Frozen Allografts Using the Bridge-in-Slot Technique

BACKGROUND

Meniscal allograft transplantation (MAT) has been shown to provide clinical benefits in patients with symptomatic meniscal deficiency in the short term and midterm. There is, however, a paucity of data regarding long-term outcomes after MAT using fresh-frozen allografts and the bridge-in-slot technique.

PURPOSE

To report clinical outcomes and revision rates after primary MAT with fresh-frozen allografts and the bridge-in-slot technique in a large case series of patients at a 10-year minimum follow-up.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A retrospective review of prospectively collected data was performed on patients undergoing primary MAT between 2001 and 2012. Lysholm, International Knee Documentation Committee subjective form, and Knee injury and Osteoarthritis Outcome Score subscales were collected preoperatively and at 1-, 2-, 5-, and minimum 10-year follow-ups. Cox proportional hazards modeling was used to identify variables associated with reoperation and failure, defined as revision MAT or conversion to arthroplasty. Reoperation was defined as a subsequent surgical intervention on the transplanted meniscus, including partial or total meniscectomy, meniscal repair, or failure as defined in the previous sentence.

RESULTS

A total of 174 patients undergoing MAT met the inclusion criteria and were followed for a mean of 12.7 ± 2.7 years (range, 10.0-21.0 years). The mean age at surgery was 28.3 ± 10.1 years. The patients were predominantly female (n = 92; 53%), and medial MAT was the most commonly performed procedure (n = 91; 52%). Concomitant procedures were performed in 115 patients (66%), with the most common procedure being osteochondral allograft transplantation (n = 59; 34%). Patients demonstrated statistically significant postoperative improvements at all time points for all patient-reported outcome measures (P≤ .0001). A total of 65 patients (37%) underwent a meniscal reoperation at a mean time of 6.6 ± 5.5 years (range, 0.3-16.7 years) postoperatively. A total of 40 patients (23%) met the criteria for failure at a mean time of 7.3 ± 5.0 years (range, 1.0-17.4 years) after MAT, with 22 of these patients having undergone a previous meniscal reoperation. At the final follow-up, 13 patients (7%) had undergone revision MAT and 27 (15%) had converted to arthroplasty. The MAT survival rates free of meniscal reoperation and failure were 73% and 85% at 10 years and 60% and 72% at 15 years, respectively. At the time of the final follow-up, 86% of patients reported that they were satisfied with their overall postoperative condition.

CONCLUSION

Primary MAT demonstrates efficacy and durability with high rates of patient satisfaction at a minimum 10-year follow-up. Patients should be counseled that although reoperation rates may approach 40% at 15 years, rates of overall revision MAT and conversion to arthroplasty remain low at long-term follow-up.

Effects of Lateral Opening-Wedge Distal Femoral Osteotomy on Meniscal Allograft Transplantation: A Biomechanical Evaluation

Background

Lateral meniscal deficiency with valgus malalignment increases the rate of lateral compartment osteoarthritis. Lateral meniscal allograft transplantation (LMAT) with a concomitant varus-producing opening-wedge distal femoral osteotomy (DFO) is an option yet to be evaluated biomechanically.

Purpose/Hypothesis

The purpose of this study was to clarify the biomechanical effects of the realignment procedure in the setting of LMAT. We hypothesized that (1) given the dependence of the lateral compartment on the lateral meniscus, a DFO and increasing degrees of varus would be insufficient to restore lateral compartment pressures to normal from a lateral meniscus-deficient state, and that (2) LMAT would restore lateral compartment pressures to the intact state while DFO would decrease lateral compartment pressures for any given state of the meniscus.

Study Design

Controlled laboratory study.

Methods

Ten cadaveric knees underwent opening-wedge varus-producing DFO secured by an external fixator. Anatomic alignment was standardized to 6° of mechanical valgus, and each joint was tested in full extension. Submeniscal placement of thin film pressure sensors allowed for the recording of contact pressure, peak contact pressure, and contact area. The specimens were loaded on a biaxial dynamic testing machine with loading angles between 9° valgus and 6° varus of mechanical alignment. Conditions tested included intact meniscus, meniscal deficiency, and meniscal transplantation.

Results

Isolated varus-producing DFO to 6° in the meniscus-deficient state failed to restore joint pressures and contact areas to the intact state, with significant changes in mean contact pressure (175%), mean peak contact pressure (135%), and contact area (-41%) (all P < .05 vs intact), while LMAT restored all outcome measures (all P > .05 compared with intact). After LMAT, every additional 1° of DFO correction contributed to a decrease in the mean contact pressure, peak pressure, and contact area of 5.6% (-0.0479 N/mm²), 5.9% (-0.154 N/mm²), and 1.4% (-6.99 mm²) for the lateral compartment and 7.3% (+0.034 N/mm²), 12.6% (+0.160 N/mm²), and 4.3% (+20.53 mm²) for the medial compartment, respectively.

Conclusion

Isolated DFO was inadequate to restore load distribution in meniscus-deficient knees, while concomitant LMAT restored near normal forces and improved the lateral compartment biomechanical profile.

Clinical Relevance

Our findings support the concomitant use of LMAT and varus-producing DFO in the setting of lateral meniscal deficiency with valgus malalignment. This study provides tools for the orthopaedic surgeon to individualize the correction for each patient.

Ipsilateral chondral lesions worsen the long-term prognosis following arthroscopic partial medial meniscectomy

PURPOSE

The effect of knee cartilage defects that are detected during partial meniscectomy remains controversial in terms of the long-term prognosis on knee function. This study aimed to investigate the effect of concurrent medial compartment focal cartilage lesions on the long-term prognosis of knee function in patients who underwent arthroscopic partial medial meniscectomy for traumatic medial meniscal tears.

METHODS

This retrospective study analyzed 46 patients who underwent arthroscopic partial medial meniscectomy between 1991 and 2008 by a single surgeon. Twenty-one patients who underwent arthroscopic partial medial meniscectomy due to traumatic meniscal tear had focal chondral lesions only at the medial compartment, and these patients were assigned to group A. Twenty-five patients who had no cartilage lesions in any compartments were assigned to group B. The age, sex, body mass index (BMI), follow-up time, age at the time of surgery, clinical and radiological scores, and perioperative arthroscopy findings were analyzed.

RESULTS

The mean follow-up time was 20 ± 3.7 years. No significant difference was found in the demographic data, and the average age of the patients at the time of operation was 35 ± 9.5 years. Both groups had improved Lysholm score at the last follow-up. Although no difference was found between the groups during the preoperative period, group B had a higher Lysholm score at the last follow-up than group A. The mean International Knee Documentation Committee (IKDC) and Knee injury and Osteoarthritis Outcome Score (KOOS) scores at the last follow-up were significantly higher in group B. The mean Kellgren-Lawrence grades in the operated knees of group A were higher than those of group B. In group A, a negative correlation was found between the BMI and postoperative Lysholm (r =  - 0.461, p = 0.03) IKDC (r =  - 0.433, p = 0.05) and KOOS (r =  - 0.565, p = 0.008) scores. In group B, no correlation was found between BMI and any score.

CONCLUSION

Among patients who underwent arthroscopic partial medial meniscectomy with an average follow-up of 20 years, those with concurrent focal cartilage defect in the medial compartment had clinically and radiologically worse outcomes than patients without any cartilage defect. Therefore, orthopedic surgeons should be meticulous before performing any arthroscopic partial medial meniscectomy in case of concurrent cartilage lesion.

LEVEL OF EVIDENCE

Level III.

A Study of the Functional Outcome of Supplementation of Hamstring Graft With Anterior Half of the Peroneus Longus Tendon in Arthroscopic Anterior Cruciate Ligament Reconstruction

INTRODUCTION

The present study was done to analyze the functional outcome, donor site morbidities, and associated parameters when using the anterior half of the peroneus longus for augmentation of an inadequate hamstring graft when performing arthroscopic anterior cruciate ligament (ACL) reconstruction.

METHODS

Thirty patients with complete ACL tears were operated on. In all these patients, the thickness or length of the hamstring graft taken was found to be inadequate (less than 8 mm and 7.5 cm, respectively). So, additionally, the anterior half of the peroneus longus tendon (AHPLT) graft was harvested to reach an optimum size of the final graft. Functional outcome was assessed using the International Knee Documentation Committee (IKDC) score at six weeks, three months, and six months. The Foot and Ankle Disability Index (FADI) score at six months was used to assess ankle stability.

RESULTS

The mean age in our study was 28.8 years with male predominance (73.33%). The mean operative time was 86.4 minutes. The mean hamstring graft thickness in our study was 6.5 mm, which improved to 9.12 mm after augmentation. The mean graft length after AHPLT augmentation was 9.38 cm. The mean IKDC score at six months was 87.35. At the end of six months, FADI scores were found within normal limits (range: 135-136) in all the patients. No complications were noted in any of the patients.

CONCLUSION

The AHPLT graft was always found to be sufficient enough for augmenting the hamstring graft to reach an acceptable thickness and length. There was no graft site morbidity and the ankle functional levels remained the same as preoperative levels, making it an excellent choice for augmentation of inadequate hamstring grafts.

The Importance of Staging Arthroscopy for Chondral Defects of the Knee

This study aims to evaluate the role of staging arthroscopy in the diagnosis of knee chondral defects and subsequent surgical planning prior to autologous chondrocyte implantation (ACI), osteochondral allograft transplantation (OCA), and meniscus allograft transplantation (MAT). All patients who underwent staging arthroscopy prior to ACI, OCA, or MAT at our institution from 2005 to 2015 were identified. Medical records were reviewed to document the diagnosis and treatment plan based on symptoms, magnetic resonance imaging (MRI) findings and previous operative records. Operative records of the subsequent staging arthroscopy procedure were reviewed to document the proposed treatment plan after arthroscopy. All changes in treatment plan following staging arthroscopy were recorded. Univariate analyses were performed to identify any significant predictors for likelihood to change. A total of 98 patients were included in our analysis. A change in surgical plan was made following arthroscopy in 36 patients (36.7%). Fourteen patients (14.3%) were found to have additional defects that warranted cartilage restoration surgery. In 15 patients (15.3%), at least one defect that was originally thought to warrant cartilage restoration surgery was found to be amenable to debridement alone. The surgical plan was changed from ACI to OCA in four cases (4.1%) and OCA to ACI in one case (1%). A previously proposed MAT was deemed unwarranted in one case (1%), and a planned meniscal repair was changed to MAT in another (1%). Patient age, sex, and the affected knee compartment were not predictors for a change in surgical plan. Body mass index (BMI) was significantly higher in patients who had a change in surgical plan (29.5 kg/m²) compared with those who did not (26.5 kg/m²). A change in surgical plan was more likely to occur for trochlear lesions (46.4%) compared with other articular surface lesions (p = 0.008). The results of our study indicate that staging arthroscopy is an important step in determining the most appropriate treatment plan for chondral defects and meniscal deficiency, particularly those with trochlear cartilage lesions.

Post-Traumatic Osteoarthritis Assessment in Emerging and Advanced Pre-Clinical Meniscus Repair Strategies: A Review

Surgical repair of meniscus injury is intended to help alleviate pain, prevent further exacerbation of the injury, restore normal knee function, and inhibit the accelerated development of post-traumatic osteoarthritis (PTOA). Meniscus injuries that are treated poorly or left untreated are reported to significantly increase the risk of PTOA in patients. Current surgical approaches for the treatment of meniscus injuries do not eliminate the risk of accelerated PTOA development. Through recent efforts by scientists to develop innovative and more effective meniscus repair strategies, the use of biologics, allografts, and scaffolds have come into the forefront in pre-clinical investigations. However, gauging the extent to which these (and other) approaches inhibit the development of PTOA in the knee joint is often overlooked, yet an important consideration for determining the overall efficacy of potential treatments. In this review, we catalog recent advancements in pre-clinical therapies for meniscus injuries and discuss the assessment methodologies that are used for gauging the success of these treatments based on their effect on PTOA severity. Methodologies include histopathological evaluation of cartilage, radiographic evaluation of the knee, analysis of knee function, and quantification of OA predictive biomarkers. Lastly, we analyze the prevalence of these methodologies using a systemic PubMed® search for original scientific journal articles published in the last 3-years. We indexed 37 meniscus repair/replacement studies conducted in live animal models. Overall, our findings show that approximately 75% of these studies have performed at least one assessment for PTOA following meniscus injury repair. Out of this, 84% studies have reported an improvement in PTOA resulting from treatment.

The Epidemiology of Meniscus Injury

Meniscus surgery is one of the most commonly performed orthopedic procedures worldwide. Modifiable risk factors for meniscus injury include body mass index, participation in athletics and occupation. Nonmodifiable risk factors include age, sex, lower extremity alignment, discoid meniscus, ligamentous laxity, and biconcave tibial plateau. Conditions commonly associated with meniscal injury are osteoarthritis, anterior cruciate ligament injury, and tibial plateau fractures. Tear type and location vary by patient age and functional status. Surgical management of meniscus injury is typically cost-effective in terms of quality-adjusted life years. The purpose of this review is to provide an overview of meniscal injury epidemiology by summarizing tear types and locations, associated conditions, and factors that increase the risk for meniscal injury. The economic burden of meniscus injury and strategies to prevent injury to the meniscus are also reviewed.

All-Inside Double-Sided Suture Repair for Longitudinal Meniscal Tears

The current consensus in the literature is that the meniscus must be saved. Even though inside-out sutures are still considered as the gold standard, the need to alternate between intra- and extra-articular structures for every stitch makes it laborious. New generations of all-inside systems are now routinely used in operating rooms and enable easier, quicker, and safer techniques. However traditional all-inside repair with limited upper fixation does not provide uniform compression from top to down, essential precondition for satisfactory meniscal healing. This Technical Note describes a simple and accessible alternative technique that provides stable fixation and overall compression of vertical meniscal tears from top to down with standard all-inside instrumentation.

A pilot study to assess the healing of meniscal tears in young adult goats

Meniscal tears are a common orthopedic injury, yet their healing is difficult to assess post-operatively. This impedes clinical decisions as the healing status of the meniscus cannot be accurately determined non-invasively. Thus, the objectives of this study were to explore the utility of a goat model and to use quantitative magnetic resonance imaging (MRI) techniques, histology, and biomechanical testing to assess the healing status of surgically induced meniscal tears. Adiabatic T1ρ, T2, and T2* relaxation times were quantified for both operated and control menisci ex vivo. Histology was used to assign healing status, assess compositional elements, and associate healing status with compositional elements. Biomechanical testing determined the failure load of healing lesions. Adiabatic T1ρ, T2, and T2* were able to quantitatively identify different healing states. Histology showed evidence of diminished proteoglycans and increased vascularity in both healed and non-healed menisci with surgically induced tears. Biomechanical results revealed that increased healing (as assessed histologically and on MRI) was associated with greater failure load. Our findings indicate increased healing is associated with greater meniscal strength and decreased signal differences (relative to contralateral controls) on MRI. This indicates that quantitative MRI may be a viable method to assess meniscal tears post-operatively.

Home-Based vs Supervised Inpatient and/or Outpatient Rehabilitation Following Knee Meniscectomy: A Systematic Review and Meta-analysis

IMPORTANCE

Arthroscopic meniscectomy is one of the most common orthopedic procedures. The optimal postoperative approach remains debated.

OBJECTIVE

To compare outcomes associated with home-based rehabilitation programs (HBP) vs standard inpatient and/or outpatient supervised physical therapy (IOP) following arthroscopic isolated meniscectomy (AM).

DATA SOURCES

A systematic literature search was conducted on PubMed, Web of Science, Cochrane Library, and Scopus databases on March 15, 2021. The included studies were published from 1982 to 2019.

STUDY SELECTION

Randomized clinical trials of patients treated with HBP vs IOP after AM were included.

DATA EXTRACTION AND SYNTHESIS

Data were independently screened and extracted by 2 authors according to the Preferred Reporting Items for Systematic Reviews (PRISMA) reporting guideline. The meta-analysis was performed using a random-effect model; when an I2 < 25% was observed, the fixed-effect model was used. The Hartung-Knapp correction was applied.

MAIN OUTCOMES AND MEASURES

The primary outcome was the Lysholm score (scale of 0-100 with higher scores indicating better knee function) and secondary outcomes were subjective International Knee Documentation Committee (IKDC) score, knee extension and flexion, thigh girth, horizontal and vertical hop test, and days to return to work, as indicated in the PROSPERO registration. Outcomes were measured in the short-term (ranging from 28 to 50 days) and the midterm (6 months).

RESULTS

In this meta-analysis of 8 RCTs including 434 patients, IOP was associated with a greater short-term improvement in Lysholm score compared with HBP, with a mean difference of -8.64 points (95% CI, -15.14 to -2.13 points; P = .02) between the 2 approached, but the sensitivity analysis showed no difference. Similarly, no statistically significant difference was detected at midterm for Lysholm score, with a mean difference between groups of -4.78 points (95% CI, -9.98 to 0.42 points; P = .07). HBP was associated with a greater short-term improvement in thigh girth, with a mean difference between groups of 1.38 cm (95% CI, 0.27 to 2.48 cm; P = .01), whereas IOP was associated with a better short-term vertical hop score, with a mean difference between groups of -3.25 cm (95% CI, -6.20 to -0.29 cm; P = .03). No differences were found for all the other secondary outcomes.

CONCLUSIONS AND RELEVANCE

No intervention was found to be superior in terms of physical and functional outcomes as well as work-related and patient-reported outcomes, both at short-term and midterm follow-up. Overall, these results suggest that HBP may be an effective management approach after AM in the general population.

Changes in Matrix Components in the Developing Human Meniscus

BACKGROUND

Treatment of meniscal tears is necessary to maintain the long-term health of the knee joint. Morphological elements, particularly vascularity, that play an important role in meniscal healing are known to change during skeletal development.

PURPOSE

To quantitatively evaluate meniscal vascularity, cellularity, collagen, and proteoglycan content by age and location during skeletal development.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Medial and lateral menisci from 14 male and 7 female cadavers aged 1 month to 11 years were collected and evaluated. For each meniscus, histologic and immunohistologic techniques were used to establish the ratio of the area of proteoglycan (safranin O) positivity to the total area (proteoglycan ratio), collagen type I and type II immunostaining positivity, number of blood vessels, and cell density. These features were evaluated over the entire meniscus and also separately in 5 circumferential segments: anterior root, anterior horn, body, posterior horn, and posterior root. Additionally, cell density and number of blood vessels were examined in 3 radial regions: inner, middle, and periphery.

RESULTS

Age was associated with a decrease in meniscal vessel count and cell density, while the proteoglycan ratio increased with skeletal maturity. Differences in vessel counts, cellular density, and proteoglycan ratio in different anatomic segments as well as in the inner, middle, and peripheral regions of the developing menisci were also observed. Collagen immunostaining results were inconsistent and not analyzed.

CONCLUSION

The cellularity and vascularity of the developing meniscus decrease with age and the proteoglycan content increases with age. All of these parameters are influenced by location within the meniscus.

CLINICAL RELEVANCE

Age and location differences in meniscal morphology, particularly in the number of blood vessels, are expected to influence meniscal healing.

Chondral lesions at the medial femoral condyle, meniscal degeneration, anterior cruciate ligament insufficiency, and lateral meniscal tears impair the middle-term results after arthroscopic partial meniscectomy

PURPOSE

The aim of the present study was to analyse which clinical, radiological and arthroscopic findings are able to predict the postoperative outcome after arthroscopic partial meniscectomy. Furthermore, the present study aimed to investigate the postoperative outcome after partial meniscectomy in patients with degenerative meniscal lesions.

METHODS

A total of 91 patients with a follow-up period of 34.7 ± 11.4 months after arthroscopic partial meniscectomy were included in this retrospective study. Clinical, radiological, and arthroscopic data were analysed at the time of follow-up. The multivariable linear regression analysis for postoperative outcome, based on the Western Ontario Meniscal Evaluation Tool (WOMET), included age, gender, body mass index, physical activity, presence of cartilage lesions, leg alignment, grade of radiographic osteoarthritis, location of meniscal lesions, meniscal extrusion, meniscal degeneration, presence of an anterior cruciate ligament tears as well as bone marrow lesions.

RESULTS

WOMET and WOMAC scores showed a significant improvement of 45.0 ± 48.1 points (CI 34.9-55.1; p ≤ 0.0001) and 75.1 ± 69.3 points (CI 60.6-89.6; p = 0.001) within the follow-up period. Multivariable linear regression analysis showed that poor preoperative WOMET scores (p = 0.001), presence of cartilage lesions at the medial femoral condylus (p = 0.001), meniscal degeneration (p = 0.008), the presence of an anterior cruciate ligament lesion (p = 0.005), and lateral meniscal tears (p = 0.039) were associated with worse postoperative outcomes. Patients with femoral bone marrow lesions had better outcome (p = 0.038).

CONCLUSION

Poor preoperative WOMET scores, presence of cartilage lesions at the medial femoral condylus, meniscal degeneration, concomitant anterior cruciate ligament lesions as well as lateral meniscal tears are correlated with worse postoperative outcomes after arthroscopic partial meniscectomy. Patients with femoral bone marrow lesions femoral are more likely to gain benefit from arthroscopic partial meniscectomy in the middle term. Despite justified recent restrictions in indication, arthroscopic partial meniscectomy seems to effectively reduce pain and alleviate symptoms in carefully selected patients with degenerative meniscal tears.

LEVEL OF EVIDENCE

III.

Does Knee Arthroscopy for Treatment of Meniscal Damage with Osteoarthritis Delay Knee Replacement Compared to Physical Therapy Alone?

BACKGROUD

To determine patient factors that lead to treatment of meniscal tears with osteoarthritis (OA) with knee arthroscopy (KA) or physical therapy only (PT-only); and to assess differences in clinical outcomes including the time to knee arthroplasty.

METHODS

Patients aged ≥ 45 years with OA at meniscal tear diagnosis were followed up from the date of surgery (KA) or first PT visit (PT-only) until partial/total knee replacement surgery, death, disenrollment, or end of study. Demographic and clinical characteristics were compared and used to derive propensity scores. A Cox proportional hazards model was used to estimate the risk of knee replacement surgery and greater healthcare utilization associated with KA vs. PT-only.

RESULTS

Among 7,026 patients (KA, 69%; PT-only, 31%), 27% had partial or total knee replacement surgery during follow-up. PT-only patients were older and more likely to be women and had more comorbidities. After accounting for differences between groups, the cumulative incidence of knee replacement was modestly but significantly higher for those who received KA than those who underwent PT-only (hazard ratio, 1.30; 95% confidence interval, 1.17-1.44; p < 0.001), although there was no significant difference in health service utilization, narcotic medication dispenses, or knee injections after initiating treatment.

CONCLUSIONS

For patients with meniscal damage complicated by OA, those who underwent KA were 30% more likely to have partial or total knee replacement surgery at any given time than those who had PT alone.

Injury of the Meniscus Root

Meniscus root tears biomechanically disrupt normal joint loading and lead to joint overload with the possible development of spontaneous osteonecrosis of the knee and early-onset osteoarthritis. Proper identification and treatment of meniscal root tears has been proven to restore joint loading and improve patient outcomes.

National Basketball Association combine performance after a partial meniscectomy

BACKGROUND

An arthroscopic meniscectomy is one of the most common orthopedic procedures in athletes. Return to play rates and deficits in muscle function have been reviewed after meniscectomy, but no study has reviewed functional performance after an isolated partial meniscectomy.

HYPOTHESIS/PURPOSE

To compare the performance of elite-level basketball players after a partial meniscectomy to a control group of players with no previous reported knee injury. We believe that there is no difference between the two groups in functional performance.

STUDY DESIGN

Case Series.

METHODS

Functional performance results from the National Basketball Association (NBA) combine were reviewed between 2000 and 2015. Twelve out of 1092 players were found to have undergone a partial meniscectomy prior to competing in the NBA combine. The partial meniscectomy group was compared to an age-, size-, and position-matched control group with respect to functional performance testing such as the shuttle run test, lane agility test, ¾ court sprint, vertical jump (no step), and vertical jump (max).

RESULTS

The meniscectomy and the control groups that there was no significant difference between the two groups in agility, quickness, sprinting, and jumping ability. However, there was a - 0.596 spearman correlation between months after surgery and agility (p = 0.041), while there was a + 0.690 and + 0.650 spearman correlation between both months after surgery and standing vertical and max vertical (p = 0.013 and p = 0.022).

CONCLUSIONS

Athletes competing in the NBA combine who have undergone a partial meniscectomy perform as well as uninjured athletes in all NBA combine performance testing. Furthermore, as athletes are further out from surgery, they have an improvement in both standing and max vertical jump.

Reducing the Volume of Low-Value Outpatient MRI Joint Examinations in Patients ≥55 Years of Age

Purpose:

Magnetic resonance imaging (MRI) is not beneficial in patients with joint pain and concomitant osteoarthritis (OA). We attempt to determine whether evaluation of OA via X-rays can reduce inappropriate MRI and computed tomography (CT) arthrogram use. In our jurisdiction, CT arthrograms are used as surrogate tests because of MRI wait times.

Materials and Methods:

Our intervention required patients ≥55 years of age scheduled for outpatient MRI of the knee/hip/shoulder at an urban hospital to have X-rays (weight bearing when appropriate) from within 1 year. Red flags (ie, neoplasm, infection) were identified for which MRI would be indicated regardless. Through review of radiographs on picture archiving and communication system/digital media and use of the validated Kellgren-Lawrence (KL) OA scale, radiologists assessed the presence and degree of OA. A finding of significant OA (KL > 2) without red flags would preclude MRI. Monthly averages of MRI and CT arthrogram examinations were measured 33 months before and 23 months following introduction of the intervention.

Results:

The proportion of protocoled MRI requisitions that were avoided was 21%. If extrapolated to the province of British Columbia, 2419 of 11 700 examinations could have been prevented in the past year. The average monthly number of knee/hip/shoulder MRI examinations as a percentage of total MRI examinations decreased from 4.9% to 4.3% ( P < .02) following the intervention. The average monthly number of knee/hip/shoulder CT arthrogram examinations decreased from 20.6 to 12.1 ( P < .0001).

Conclusion:

We were able to decrease the number of MRI and CT arthrogram examinations in patients ≥55 years of age with joint pain by implementing an evaluation for OA via recent X-ray imaging.

The effects of knee meniscectomy on the development of osteoarthritis in the patellofemoral joint 40 years following meniscectomy

Most knee osteoarthritis and meniscectomy studies focus on osteoarthritis in the tibiofemoral joint and ignore the patellofemoral joint. This study aims to assess the long-term effects of total meniscectomy on the patellofemoral joint. To our knowledge, this is the only study of osteoarthritis in the patellofemoral joint following meniscectomy that extends to a 40-year follow-up period. Twenty-two patients with osteoarthritis were evaluated at a mean of 40 years post-meniscectomy using standardised weight-bearing radiographs of the operated and non-operated knees. Patellofemoral joint osteoarthritis was diagnosed by the presence of osteophytes and joint space narrowing to less than 5 mm. Kellgren and Lawrence scores were calculated from the radiographs. Patellofemoral joint osteoarthritis and tibiofemoral joint osteoarthritis were correlated with International Knee Documentation Committee scores and range of movement measurements. A significant difference was observed between the operated and non-operated knees in terms of patellofemoral joint osteophyte formation. There was a significant difference in tibiofemoral joint Kellgren and Lawrence scores, International Knee Documentation Committee scores and range of movement measurements between knees with lateral facet patellofemoral joint space of < 5 mm and > 5 mm. This study shows an association between open total meniscectomy and patellofemoral joint osteoarthritis at 40 years following surgery. There was also an association between patellofemoral joint space narrowing in the lateral facet and tibiofemoral joint osteoarthritis. Possible causes include altered biomechanical loading patterns following meniscectomy as well as global processes within the knee.

Treatment options for the symptomatic post-meniscectomy knee

PURPOSE

To provide a current review on the evidence for management of the symptomatic meniscus-deficient knee.

METHODS

A literature review was performed detailing the natural history and origin of symptoms in a meniscus-deficient knee, in addition to strategies for non-surgical management, meniscus scaffolds, meniscus allograft transplantation (MAT), isolated cartilage repair, unloading osteotomies, meniscus prosthesis, and joint replacements which were revealed as treatment possibilities.

RESULTS

Meniscus deficiency was recognized to lead to an early onset knee osteoarthritis (OA). A subset of patients develop post-meniscectomy syndrome: dull and nagging pain after a short pain-free interval subsequently to meniscectomy, which can be accompanied by transient effusions. Evidence for non-surgical management of post-meniscectomy knee pain is lacking. Two available meniscus scaffolds, indicated for symptomatic segmental meniscus deficiency, show pain relief at mid-term follow-up, and effect on joint preservation is unclear. MAT represents a durable solution for sub/total meniscus deficiency (80% survival at 10 years), but it is still considered a temporary solution for post-meniscectomy pain. MAT may also reduce the progression of OA. Isolated cartilage repair without a meniscus reconstruction is commonly performed, but better results were reported with preserved or reconstructed menisci. Osteotomies are used in the combination of misaligned knee and meniscus reconstruction or as pain solution for irreversible unilateral knee structural changes following a meniscectomy. Polycarbonate-urethane medial meniscus prosthesis is currently undergoing clinical trial. Joint replacements should be limited to later stages of post-meniscectomy OA.

CONCLUSIONS

Post-meniscectomy pain syndrome and post-meniscectomy knee OA are common findings after meniscus resection. Short-term pain relief is provided by non-surgical management, mid-term pain relief by meniscus scaffolds, and long-term relief by MAT, though each has differing indications. In later stages, osteotomies and joint replacements are indicated.

LEVEL OF EVIDENCE

IV.

The 50 Most-Cited Articles in Meniscal Allograft Transplantation Research: A Bibliometric Analysis

OBJECTIVE

To identify the 50 most-cited articles in meniscal allograft transplantation (MAT) research and analyze their characteristics.

DESIGN

In September 2017, the Scopus database was queried to identify the 50 most-cited articles in MAT research. Variables analyzed include number of citations, publication year, journal, institution, country of origin, article type, study design, and level of evidence. Citation density was calculated for each article. The correlation between citation density and publication year and the correlation between level of evidence and number of citations, citation density, and publication year were computed.

RESULTS

The 50 most-cited articles were published in 12 journals between 1986 and 2011. The number of citations ranged from 59 to 290 (109.3 ± 48.6). Citation density ranged from 2.7 to 17.6 citations per year (7.0 ± 3.3). There was a positive correlation between citation density and publication year ( r = +0.489, P < 0.001). Overall, 56% of the articles were clinical and 44% were basic science. Of the 28 clinical articles, 61% were level IV or V evidence. Level of evidence was not significantly correlated with number of citations ( r = -0.059, P = 0.766), citation density ( r = +0.030, P = 0.880), or publication year ( r = -0.0009, P = 0.996).

CONCLUSION

This analysis provides the orthopedic community with a readily accessible list of the classic citations in MAT research and provides insight into the historical development of this procedure. Although there was a moderate positive correlation between citation density and publication year, articles with stronger levels of evidence were not more frequently cited despite the increasing trend toward evidence-based practice.

A Systematic Review and Meta-Analysis of Arthroscopic Meniscus Repair in Young Patients: Comparison of All-Inside and Inside-Out Suture Techniques

Purpose

The purposes of the present study were to review published studies that investigated arthroscopic meniscus repair to treat meniscus injury in young patients and to compare all-inside and inside-out suture techniques.

Methods

Various electronic databases were queried for published articles, and this search was updated in August 2017 for evaluating the outcomes of arthroscopic meniscus surgery in young patients. Data search, extraction, analysis, and quality assessment were performed according to the Cochrane Collaboration guidelines, and the clinical outcomes were evaluated using various outcome values in young patients according to suture techniques.

Results

Three randomized controlled trials and three prospective comparative studies were included in this systematic review and meta-analysis. There were no significant differences in clinical outcomes such as meniscus healing rate (risk ratio [RR], 1.11; 95% confidence interval [CI], 0.90 to 1.37; I²=39%) and perioperative complications (RR, 0.62; 95% CI, 0.23 to 1.72; I²=43%) between all-inside and inside-out techniques for meniscus repair.

Conclusions

The present study shows favorable results for clinical outcomes such as meniscus healing rate and perioperative complications in young patients. Furthermore, based on our results, both all-inside and inside-out meniscal suture techniques are equally effective in these patients.

Outcomes of Arthroscopic Posterior Medial Meniscus Root Repair: Association With Body Mass Index

INTRODUCTION

The purpose of this study was to assess the association of outcomes from posterior medial meniscus root repairs with patient age, sex, and body mass index (BMI).

METHODS

Patients who underwent arthroscopic posterior medial meniscus root repair completed the Knee Injury and Osteoarthritis Outcome Score (KOOS) and reported subsequent surgeries. The association of patient factors with subsequent surgery and clinical osteoarthritis (OA) based on the KOOS score was evaluated.

RESULTS

Minimum 2-year follow-up was available on 22/25 patients (88%). Two patients (9.1%) had subsequent surgeries, and 10 (45.5%) met the KOOS criteria for OA. A BMI over 35 kg/m was associated with repeat surgery (25% versus 0%; P = 0.049) and clinical OA (75% versus 28.6%; P = 0.035).

CONCLUSION

Although arthroscopic repair of posterior medial root tears has good clinical outcomes and a low rate of subsequent surgery, an elevated BMI level is associated with worse clinical outcomes and a higher rate of subsequent surgery.

Comparison of patellar tendon versus hamstrings autografts for anterior cruciate ligament reconstruction in Indian population: A randomised control trial study

Disruption of anterior cruciate ligament (ACL) is a common ligamentous injury of the knee. The best choice of graft for reconstruction remains undecided. This prospective, randomized clinical trial aimed to compare clinical results of bone-patellar tendon-bone (BPTB) grafts and four-strand semitendinosus-gracilis (QHT) grafts for ACL reconstruction over a 1-year follow-up interval in Indian population.

METHODS

42 consecutive patients with ACL injury were recruited, by pick and draw method and allotted into two groups with 21 patients in each group. Group A patients underwent arthroscopic ACL reconstruction using BPTB graft while QHT autograft was used for patients in Group B. All the patients underwent standard ipsilateral arthroscopic ACL reconstruction procedure using a single incision, antero-medial (AM) portal technique for BPTB or the QHT autograft by a same surgeon. Patients were followed up regularly for a minimum period of 1 year.

RESULTS

After one year, the Cincinnati score was 91 ± 4.117 in BPTB group and 89.29 ± 5.371 in QHT group (P = 0.282). There was no significant difference between the two groups in the mean scores with respect to pain, overall activity level and running in the Cincinnati score. None of the patients complained of the knee giving way. Similarly, at 1 year, the Lysholm score was 92.84 ± 2.630 and 90.55 ± 2.395 in the two groups respectively (P = 0.842). There were no episodes of locking or instability and there was no significant difference in the mean Lysholm scores regarding pain and squatting.

CONCLUSION

There was no significant functional difference between the two grafts in terms of Lysholm and the Cincinnati score, anterior knee laxity and altered sensation over proximal leg. The patients with QHT groups performed better than BPTB functionally at 6 month so early return to sport is possible even with QHT autograft.

Articular cartilage lesions associated with complete lateral meniscal tears in the dog

OBJECTIVE

To describe articular cartilage (AC) lesions associated with complete lateral meniscal tears in dogs.

STUDY DESIGN

Observational series.

ANIMALS

Seventeen dogs with arthroscopic evidence of a complete lateral meniscal tear and associated AC lesions.

METHODS

Medical records of dogs with arthroscopic evidence of complete lateral meniscal tear and associated AC lesions between March 2006 and December 2017 were examined for arthroscopic findings.

RESULTS

The cranial cruciate ligament (CrCL) was intact in 11 of 17 dogs, partially ruptured but competent in 4 of 17 dogs, and completely ruptured in 2 of 17 dogs. All dogs had grossly normal caudal cruciate ligament, medial meniscus, and AC of the medial compartment. In each dog, a complete radial tear of the caudal body of the lateral meniscus was associated with degenerative osteoarthritis (OA) of the lateral compartment of the stifle. The Outerbridge score of the lateral tibial condyle and lateral femoral condyle was 5 of 5 in 15 dogs, 3 of 5 in 1 dog, and 4 of 5 in 1 dog.

CONCLUSION

Dogs with complete tears of the lateral meniscus developed degenerative OA of the lateral compartment of the stifle leading to AC loss and clinical dysfunction.

CLINICAL SIGNIFICANCE

Complete lateral meniscal tears may occur as isolated injuries in dogs with a functional CrCL.

Complete tear of the lateral meniscus posterior root is associated with meniscal extrusion in anterior cruciate ligament deficient knees

This study aimed to evaluate the relationship between preoperative lateral meniscal extrusion (LME) and arthroscopic findings of lateral meniscus posterior root tear (LMPRT) in knees with anterior cruciate ligament (ACL) tear. Thirty-five knees that had LMPRTs with concomitant ACL tears on arthroscopy were evaluated. Patients were divided into two groups, partial and complete root tears, via arthroscopic findings at the time of ACL reconstruction. For comparison, we added two groups, using the same database; 20 normal knees (normal group) and 20 ACL-injured knees without LM injury (intact LM group). We retrospectively measured preoperative LMEs using magnetic resonance imaging (MRI). Twenty-three knees had partial LMPRTs. Complete LMPRTs were observed in 12 knees. The average LME was -0.1 ± 0.4 mm in the normal group, 0.2 ± 0.5 mm in the intact LM group, 0.4 ± 0.8 mm in the partial LMPRT group, and 2.0 ± 0.6 mm in the complete LMPRT group. A significant difference in preoperative LMEs was observed between the complete LMPRT group and the other groups (p < 0.001). The receiver operating curve analysis, which distinguishes a partial tear from a complete tear, identified an optimal cut-off point of 1.1 mm for preoperative LME. This LME cut-off had a sensitivity of 100% and specificity of 83% for complete LMPRT. We found that preoperative LMEs were larger in complete LMPRTs associated with ACL injuries than in partial LMPRTs. Our results suggest that preoperative MRI-detected LME may be a useful indicator for estimating LMPRT severity in ACL-injured knees.

LEVEL OF EVIDENCE

Retrospective comparative study level IV. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1894-1900, 2018.

MMP-3 in the peripheral serum as a biomarker of knee osteoarthritis, 40 years after open total knee meniscectomy

BACKGROUND

To explore potential biomarkers in a meniscectomy-induced knee osteoarthritis model, at forty years after meniscectomy.

METHODS

We carried out a forty-year study of 53 patients who, as adolescents, underwent open total meniscectomy and assessed two potential synovial and serum biomarkers, namely glycosaminoglycan (GAG) and matrix metalloproteinase-3 (MMP-3). Of the 30 patients available for review, 8 had contralateral knee operations and were excluded. Of the remaining 22 patients, 17 had successful operated knee synovial fluid aspirations and 8 also had successful contralateral control knee aspirations. GAG and MMP3 levels in the synovial fluid and peripheral serum was measured using Alcian blue precipitation and ELISA quantification, respectively. Patients also had their knee radiographs assessed and their radiographic osteoarthritis classified as per the Kellgren-Lawrence and Ahlbӓck systems.

RESULTS

At forty years after meniscectomy, synovial MMP-3 levels remain increased (p = 0.0132) while GAG levels were reduced (p = 0.0487) when compared to controls and these two levels correlate inversely. Furthermore, levels of synovial MMP-3 significantly correlated (p = 0.0032, r = 0.7734; p = 0.0256, r = 0.5552) and GAG levels significantly inversely correlated (p = 0.0308, r = - 0.6220; p = 0.0135, r = - 0.6024), respectively, with both radiological scoring systems. Interestingly, we found that the levels of serum MMP-3 correlated only with the synovial fluid levels of MMP-3 in the operated knee and not with the non-operated joint (p = 0.0252, r = 0.7706 vs. p = 0.0764, r = 0.6576). Multiple regression analysis for patient's quality of life based on these biomarkers revealed an almost perfect result with an R2 of 0.9998 and a p value = 0.0087.

CONCLUSION

Our results suggest that serum levels of MMP3 could be used as a potential biomarker for knee osteoarthritis, using a simple blood test. Larger cohorts are desirable in order to prove or disprove this finding.

Sport-specific outcomes after isolated meniscal repair: a systematic review

PURPOSE

The purpose of this systematic review was to assess sport-specific outcomes after repair of isolated meniscal tears.

METHODS

A systematic electronic search of the MEDLINE and Cochrane database was performed in May 2016 to identify studies that reported sport-specific outcomes after isolated meniscal repair. Included studies were abstracted regarding study characteristics, patient demographics, surgical technique, rehabilitation, and outcome measures. The methodological quality of the included studies was assessed with the Coleman Methodology Score (CMS).

RESULTS

Twenty-eight studies with a total of 664 patients met the inclusion criteria. The methodological quality of the included studies was moderate, with a mean CMS of 69.7 ± 8.3. The mean patient age was 26 ± 7.2 years and 71% of patients were male. Mean preoperative Tegner score improved from 3.5 ± 0.3 to 6.2 ± 0.8 postoperatively. Comparing preinjury and postoperative Tegner scores, comparable values were observed (6.3 ± 1.1 and 5.7 ± 0.8, respectively). Return to sports on the preinjury level was achieved in 89%. Mixed-level populations returned to their preinjury activity level in 90% and professional athletes in 86%. Mean delay of return to sports varied between 4.3 and 6.5 months, with comparable results between professional and mixed-level athletes. The pooled failure rate was 21%. The failure rate was lower in professional athletes compared to mixed-level athletes (9% vs. 22%).

CONCLUSION

This systematic review suggests that isolated repair of meniscal tears results in good to excellent sport-specific outcomes and a high return to sports rate in both recreational and professional athletes. The failure rate is comparable to systematic reviews not focusing on sportive patients.

LEVEL OF EVIDENCE

Level IV systematic review of Level I to Level IV studies.

Can we predict the clinical outcome of arthroscopic partial meniscectomy? A systematic review

NHS-Prospero registration number

42016048592

Objective

In order to make a more evidence-based selection of patients who would benefit the most from arthroscopic partial meniscectomy (APM), knowledge of prognostic factors is essential. We conducted a systematic review of predictors for the clinical outcome following APM.

Design

Systematic review

Data sources

Medline, Embase, Cochrane Central Register, Web of Science, SPORTDiscus, PubMed Publisher, Google Scholar

Inclusion criteria

Report an association between factor(s) and clinical outcome; validated questionnaire; follow-up >1 year.

Exclusion criteria

<20 subjects; anterior cruciate ligament-deficient patients; discoid menisci; meniscus repair, transplantation or implants; total or open meniscectomy.

Methods

One reviewer extracted the data, two reviewers assessed the risk of bias and performed a best-evidence synthesis.

Results

Finally, 32 studies met the inclusion criteria. Moderate evidence was found, that the presence of radiological knee osteoarthritis at baseline and longer duration of symptoms (>1 year) are associated with worse clinical outcome following APM. In addition, resecting >50% of meniscal tissue and leaving a non-intact meniscal rim after meniscectomy are intra-articular predictive factors for worse clinical outcome. Moderate evidence was found that sex, onset of symptoms (acute or chronic), tear type or preoperative sport level are not predictors for clinical outcome. Conflicting evidence was found for the prognostic value of age, perioperative chondral damage, body mass index and leg alignment.

Summary/conclusion

Long duration of symptoms (>1 year), radiological knee osteoarthritis and resecting >50% of meniscus are associated with a worse clinical outcome following APM. These prognostic factors should be considered in clinical decision making for patients with meniscal tears.

Coronal Knee Alignment 40 Years after Total Meniscectomy in Adolescents: A Prospective Cohort Study

Introduction:

Meniscectomies result in altered knee biomechanics and increase contact forces on the operated knee joint.

Methods:

We assessed coronal knee alignment in relation to radiological osteoarthritis grading, clinical range of movement and patient reported outcome measures 40 years after total open meniscectomies in adolescence. Thirty eight knees (30 patients) that underwent total open meniscectomy were assessed on standardised weight-bearing anteroposterior radiographs for deviation from ‘physiological valgus angle’ in either direction (magnitude of malalignment). These values were analysed as per site of meniscectomy for correlations with radiographic scoring systems, range of motion and patient reported outcome measures.

Results:

Tibiofemoral angle was significantly more varus, and the magnitude of malalignment was significantly higher for the medial meniscectomy patients. The range of flexion was lower for those patients who underwent medial and lateral meniscectomies of the same knee. The patients who underwent meniscectomies of both knees had worse scores for IKDC and KOOS quality of life. Tibiofemoral angle, magnitude of malalignment and range of flexion strongly correlated with Ahlback, and Kellgren and Laurence scores, but patient reported that outcome measures did not correlate.

Conclusion:

Meniscectomy induced malalignment corresponds to the site of meniscectomy and the radiographic degree of osteoarthritis. While malalignment and reduced range of movement correlate well with worsening radiographic signs of arthritis, patient reported outcome measures do not correlate.

Meniscal transplantation: procedures, outcomes, and rehabilitation

Meniscal allograft transplantation (MAT) is a possible treatment option for patients with joint pain after meniscectomy. It is necessary that the joint be aligned and stable. Current evidence shows that MAT improves pain and mechanical function in the mid to long term with patients reporting significantly improved outcomes at up to 15 years following surgery. Studies on survivorship showed up to 76% graft survival at 10 years. Recent studies have suggested a chondroprotective effect, but there is, at present, no evidence to support MAT in the prevention of osteoarthritis. This review article reported the current evidence for MAT showing support for fresh frozen, nonirradiated allografts. However, further research is required to determine the ideal indications for MAT, the optimal graft fixation method, and the safest rehabilitation protocol.

Transplantation of Chemically Processed Decellularized Meniscal Allografts

Objective The aim of this study was to evaluate the chondroprotective effect of chemically decellularized meniscal allografts transplanted into the knee joints of adult merino sheep. Methods Lateral sheep meniscal allografts were chemically processed by a multistep method to yield acellular, sterile grafts. The grafts were transplanted into the knee joints of sheep that were treated by lateral meniscectomy. Joints treated by meniscectomy only and untreated joints served as controls. The joints were analyzed morphologically 6 and 26 weeks after surgery by the macroscopical and histological OARSI (Osteoarthritis Research Society International) score. Additionally, the meniscal grafts were biomechanically tested by cyclic indentation. Results Lateral meniscectomy was associated with significant degenerative changes of the articular cartilage of the lateral joint compartment. Transplanted lateral meniscal allografts retained their integrity during the observation period without inducing significant synovitis or foreign body reactions. Cellular repopulation of the grafts was only present on the surface and the periphery of the lateral meniscus, but was still completely lacking in the center of the grafts at week 26. Transplantation of processed meniscal allografts could not prevent degenerative changes of the articular cartilage in the lateral joint compartment. Compared with healthy menisci, the processed grafts were characterized by a significantly reduced dynamic modulus, which did not improve during the observation period of 26 weeks in vivo. Conclusion Chemically decellularized meniscal allografts proved their biocompatibility and durability without inducing immunogenic reactions. However, insufficient recellularization and inferior stiffness of the grafts hampered chondroprotective effects on the articular cartilage.

The biology of meniscal pathology in osteoarthritis and its contribution to joint disease: beyond simple mechanics

The meniscal cartilages in the knee function to improve congruity of the medial and lateral femoro-tibial joints and play critical roles in load distribution and joint stability. Meniscal tears of various configurations are one of the most common conditions of the knee and are associated with an increased risk of developing osteoarthritis (OA). While this risk has been largely attributed to loss of the biomechanical functions of the menisci, there is accumulating evidence suggesting that other aspects of meniscal biology may play a role in determining the long-term consequences of meniscal damage for joint health. In this narrative review, we examine the existing literature and present some new data implicating synthesis and secretion of enzymes and other pro-catabolic mediators by injured and degenerate menisci, contributing to the pathological change in other knee joint tissues in OA.

Clinical and MRI Evaluation of Meniscal Tears Repaired with Bioabsorbable Arrows

Background and Aims:

Excision of meniscal tissue has been shown to increase the risk of degenerative changes of the knee joint. Whenever possible, meniscus repair has become the procedure of choice for treatment of meniscal tears.

Materials and Methods:

The present retrospective study evaluated the healing results of 77 meniscal ruptures treated with the an all-inside technique (Biofix meniscus arrow). The study group consisted of 73 patients with 77 longitudinal, vertical meniscal ruptures treated at Helsinki University Hospital between the beginning of January 1997 and the end of March 2001. The patients who had not received secondary surgery for failed repair during the follow-up period were examined clinically and with MRI.

Results:

Fifty-one out of 77 meniscal ruptures (66%) healed clinically. In repairs performed in conjunction with ligament reconstruction the healing rate was higher (79%) than in the isolated tears (56%). The poorest results were seen in the very long vertical tears with luxation of the meniscus (38% healing rate).

Conclusions:

Bioabsorbable arrows offer a good alternative for treatment of meniscal ruptures, but the arrows alone do not seem to be sufficient to provide a reliable long-lasting result in the repair of very unstable meniscal ruptures.

The Optimal Suture Site for the Repair of Posterior Horn Root Tears: Biomechanical Evaluation of Pullout Strength in Porcine Menisci

PURPOSE

There are few studies on biomechanical evaluation of suture points in repair of root tears. The purpose of this study was to determine the point of greatest pullout strength for root tear repair.

MATERIALS AND METHODS

A total of 120 fresh porcine medial menisci were obtained. The red-red and red-white zones of the meniscus were divided by two lines designated as lines A and B (groups A and B). Groups A and B were further divided into three groups each by dividing lines A and B into three points: 3, 5, and 7 mm from the meniscal ligament root insertion. Vertical meniscal repair was performed on each point. The pullout failure strength was tested using a biaxial servohydraulic testing machine.

RESULTS

The average maximal load at failure was significantly greater in group A than group B (87.65 vs. 62.93; p<0.001) The average length at maximal load failure was greater in group A than group B (4.35 vs. 3.2; p<0.001). Among the subgroups of 3, 5, and 7 mm in both groups A and B, 7 mm showed the greatest maximal load (p<0.001).

CONCLUSIONS

The pullout strength was statistically significantly greater in group A than group B and in the 7 mm subgroup than the 3 and 5 mm subgroups. Thus, the 7 mm subgroup in group A showed the greatest pullout strength.

Biomechanical Comparison of Parallel and Crossed Suture Repair for Longitudinal Meniscus Tears

Background:

Longitudinal meniscus tears are commonly encountered in clinical practice. Meniscus repair devices have been previously tested and presented; however, prior studies have not evaluated repair construct designs head to head. This study compared a new-generation meniscus repair device, SpeedCinch, with a similar established device, Fast-Fix 360, and a parallel repair construct to a crossed construct. Both devices utilize self-adjusting No. 2-0 ultra–high molecular weight polyethylene (UHMWPE) and 2 polyether ether ketone (PEEK) anchors.

Hypothesis:

Crossed suture repair constructs have higher failure loads and stiffness compared with simple parallel constructs. The newer repair device would exhibit similar performance to an established device.

Study Design:

Controlled laboratory study.

Methods:

Sutures were placed in an open fashion into the body and posterior horn regions of the medial and lateral menisci in 16 cadaveric knees. Evaluation of 2 repair devices and 2 repair constructs created 4 groups: 2 parallel vertical sutures created with the Fast-Fix 360 (2PFF), 2 crossed vertical sutures created with the Fast-Fix 360 (2XFF), 2 parallel vertical sutures created with the SpeedCinch (2PSC), and 2 crossed vertical sutures created with the SpeedCinch (2XSC). After open placement of the repair construct, each meniscus was explanted and tested to failure on a uniaxial material testing machine. All data were checked for normality of distribution, and 1-way analysis of variance by ranks was chosen to evaluate for statistical significance of maximum failure load and stiffness between groups. Statistical significance was defined as P < .05.

Results:

The mean maximum failure loads ± 95% CI (range) were 89.6 ± 16.3 N (125.7-47.8 N) (2PFF), 72.1 ± 11.7 N (103.4-47.6 N) (2XFF), 71.9 ± 15.5 N (109.4-41.3 N) (2PSC), and 79.5 ± 25.4 N (119.1-30.9 N) (2XSC). Interconstruct comparison revealed no statistical difference between all 4 constructs regarding maximum failure loads (P = .49). Stiffness values were also similar, with no statistical difference on comparison (P = .28).

Conclusion:

Both devices in the current study had similar failure load and stiffness when 2 vertical or 2 crossed sutures were tested in cadaveric human menisci.

Clinical Relevance:

Simple parallel vertical sutures perform similarly to crossed suture patterns at the time of implantation.

Meniscal transplant in children

PURPOSE OF REVIEW

The purpose is to review and discuss the fundamentals, indications, surgical technique, controversies, and outcomes regarding meniscal transplantation, focusing on available evidence in pediatric populations.

RECENT FINDINGS

Recent studies have confirmed meniscal allograft transplantation as an effective procedure to improve symptoms, knee function, and quality of life following meniscectomy, particularly in symptomatic young patients. Associated procedures, such as osteotomies and cartilage-related surgeries, have expanded the indications for transplantation. Most patients return to sports following meniscal transplantation, and the procedure does not preclude the potential return to high-level athletic competition. The chondroprotective effect of transplantation has not been proven and as a result the role of prophylactic transplantation remains unclear.

SUMMARY

Meniscal allograft transplantation is indicated following symptomatic meniscal loss in young, active patients to relieve pain and improve knee function. The quality of the available evidence regarding meniscal transplantation is limited, and no published series to date has focused exclusively on a pediatric population. Further high-quality studies are needed to establish improved indications, timing, and outcomes in a pediatric population.

Targeted transplantation of iron oxide-labeled, adipose-derived mesenchymal stem cells in promoting meniscus regeneration following a rabbit massive meniscal defect

Repair of a massive meniscal defect remains a challenge in the clinic. However, targeted magnetic cell delivery, an emerging technique, may be useful in its treatment. The present study aimed to determine the effect of targeted intra-articular injection of superparamagnetic iron oxide (SPIO)-labeled adipose-derived mesenchymal stem cells (ASCs) in a rabbit model of a massive meniscal defect. ASCs may be directly labeled and almost 100% of the ASCs were labeled with SPIO after 24 h; these SPIO-labeled ASCs may be orientated by magnet. The centrifuged SPIO-labeled ASCs precipitations may be detected by magnetic resonance imaging (MRI). The anterior half of the medial meniscus of 18 New Zealand Rabbits was excised. After 7 days, the rabbits were randomized to injections of 2×10⁶ SPIO-labeled ASCs, 2×10⁶ unlabeled ASCs or saline. Permanent magnets were fixed to the outside of the operated joints for one day, and after 6 and 12 weeks, the knee joints were examined using MRI, gross and histological observation, and Prussian blue staining. Marked hypointense artifacts caused by SPIO-positive cells in the meniscus were detected using MRI. Histological observation revealed that the anterior portion of the meniscus was similar to the native tissue, demonstrating typical fibrochondrocytes surrounded by richer extracellular matrix in the SPIO-ASCs group. Collagen-rich matrix bridging the interface and the neo-meniscus integrated well with its host meniscus. Furthermore, degenerative changes occurred in all groups, but intra-articular injection of SPIO-ASCs or ASCs alleviated these degenerative changes. Prussian blue staining indicated that the implanted ASCs were directly associated with the regenerated tissue. Overall, targeted intra-articular delivery of SPIO-ASCs promoted meniscal regeneration whilst providing protective effects from osteoarthritic damage.

The Meniscus-Deficient Knee: Biomechanics, Evaluation, and Treatment Options

Meniscal tears are the most common knee injury, and partial meniscectomies are the most common orthopaedic surgical procedure. The injured meniscus has an impaired ability to distribute load and resist tibial translation. Partial or complete loss of the meniscus promotes early development of chondromalacia and osteoarthritis. The primary goal of treatment for meniscus-deficient knees is to provide symptomatic relief, ideally to delay advanced joint space narrowing, and ultimately, joint replacement. Surgical treatments, including meniscal allograft transplantation (MAT), high tibial osteotomy (HTO), and distal femoral osteotomy (DFO), are options that attempt to decrease the loads on the articular cartilage of the meniscus-deficient compartment by replacing meniscal tissue or altering joint alignment. Clinical and biomechanical studies have reported promising outcomes for MAT, HTO, and DFO in the postmeniscectomized knee. These procedures can be performed alone or in conjunction with ligament reconstruction or chondral procedures (reparative, restorative, or reconstructive) to optimize stability and longevity of the knee. Complications can include fracture, nonunion, patella baja, compartment syndrome, infection, and deep venous thrombosis. MAT, HTO, and DFO are effective options for young patients suffering from pain and functional limitations secondary to meniscal deficiency.

A conceptual framework for a sports knee injury performance profile (SKIPP) and return to activity criteria (RTAC)

Injuries to the knee, including intra-articular fractures, ligamentous ruptures, and meniscal and articular cartilage lesions, are commonplace within sports. Despite advancements in surgical techniques and enhanced rehabilitation, athletes returning to cutting, pivoting, and jumping sports after a knee injury are at greater risk of sustaining a second injury. The clinical utility of objective criteria presents a decision-making challenge to ensure athletes are fully rehabilitated and safe to return to sport. A system centered on specific indicators that can be used to develop a comprehensive profile to monitor rehabilitation progression and to establish return to activity criteria is recommended to clear athletes to begin a progressive and systematic approach to activities and sports. Integration of a sports knee injury performance profile with return to activity criteria can guide clinicians in facilitating an athlete's safe return to sport, prevention of subsequent injury, and life-long knee joint health.

Arthroscopic repair of the meniscal injury using meniscal repair device

BACKGROUND

Total meniscus resection after meniscus tear usually leads to faster degeneration and osteoarthritis of the knee joint. Preservation and repair of the injured menisci are therefore of great clinical importance. The aim of this study was to evaluate the clinical effects of arthroscopic repair of meniscal injuries using the Fast-Fix device.

MATERIALS AND METHODS

96 patients (58 males, 38 females) with mean age of 24.3 years (range 12-46 years)) with a meniscus injury were treated with the Fast-Fix device under arthroscopy between July 2007 and June 2009. The right and left knees were involved in 46 and 50 patients respectively. In 12, 46 and 38 patients, the injury was located in the anterior horn, body and posterior horn respectively. In 38, 45 and 13 patients, it was in the red, red-white, and white regions, respectively. All-inside and outside-in techniques were used for these meniscal injuries. Criteria for successful surgery were no locking pain or swelling and a negative McMurray test.

RESULTS

The mean followup period was 3.7 years (range 2-5 years). The surgical success rate was 91.7% (n = 88). The mean Lysholm score increased from 47.8 ± 10.4 preoperatively to 85.7 ± 12.8 postoperatively. The mean Tegner activity score was 7.4 ± 1.6 (range 5-9) preinjury, 2.1 ± 0.9 (range 0-4) preoperatively and 7.2 ± 2.2 (range 4-10) postoperatively (P < 0.001). A total of 92 patients (95.8%) returned to full-time work. The International Knee Documentation Committee score increased from 32.7 ± 10.7 (range 10.3-51.7) preoperatively to 82.5 ± 5.1 (range 65.1-91.2) postoperatively (P < 0.001).

CONCLUSIONS

The Fast-Fix system is an efficient, safe and effective suture technique for meniscal repair.

Meniscal Transplantation in Symptomatic Patients Under Fifty Years of Age: Survivorship Analysis

BACKGROUND

The purpose of this study was to prospectively evaluate the long-term results and survivorship of meniscal transplantation in a consecutive series of patients.

METHODS

Forty cryopreserved menisci were implanted into thirty-eight patients. Survival end points were transplant removal, revision, or tibiofemoral compartment pain with daily activities. A worst-case scenario was also calculated for patients who did not have symptoms related to the transplant; in this scenario, additional end points were grade-3 signal intensity, extrusion (>50% of meniscal width), or tear on magnetic resonance imaging; signs of meniscal tear on examination; or radiographic loss of joint space. The Cincinnati Knee and International Knee Documentation Committee rating systems were used.

RESULTS

All patients were followed for a mean postoperative time of eleven years. The estimated probabilities of transplant survival were 88% at five years, 63% at ten years, and 40% at fifteen years. Worst-case survival rate estimates were 73% at five years, 68% at seven years, 48% at ten years, and 15% at fifteen years. The mean time to failure was 8.2 years for medial transplants and 7.6 years for lateral transplants. The functional analysis detected significant improvements for pain, swelling, the patient's perception of the knee condition, walking, stair-climbing, and squatting (p < 0.05).

CONCLUSIONS

The survivorship analysis showed that, at ten years, 63% had not required subsequent surgery and were asymptomatic with daily activities. However, this percentage decreased to 40% at fifteen years. Although the data indicated that the majority of cryopreserved meniscal transplants may fail in the long term, the resolution of symptoms and improvement in function for several years justifies the procedure in young patients who are symptomatic after meniscectomy. Patients should be advised that the procedure is not curative in the long term and additional surgery will most likely be required.

Iatrogenic injury of the anterior meniscal root attachments following anterior cruciate ligament reconstruction tunnel reaming

PURPOSE

To determine whether reaming of anterior cruciate ligament (ACL) reconstruction tibial tunnels with a 10-mm-diameter reamer would result in injury to the anterior roots of the medial and lateral menisci in an in vitro model when using a tibial aiming device at two settings (40° and 60°).

METHODS

Three-dimensional footprints of the ACL and the anterior roots of the menisci were measured for 12 human cadaveric tibias. Measurements were taken before and after attempted reaming of an ACL tibial reconstruction tunnel in the calculated ACL centre using a tibial aiming device set at two angles (40° and 60°).

RESULTS

Iatrogenic injury to the anterior root of the medial meniscus caused by overlap with the reamed tibial tunnel was found in 3/6 specimens in Group 1 (40°) and 0/6 specimens in Group 2 (60°). The average area of iatrogenic injury in Group 1 was 9.6 mm(2) (8.6 % of the root). There was iatrogenic injury to the anterior root of the lateral meniscus in 4/6 specimens for both groups. The average area of iatrogenic injury was 20.5 mm(2) (28.8 %) for Group 1 and 16.2 mm(2) (25.9 %) for Group 2.

CONCLUSIONS

Reaming of ACL tibial reconstruction tunnels carries a risk of iatrogenic injury to the anterior meniscus roots, even when tunnels are reamed based on guide pin placement in the calculated centre of the ACL. Reaming at varying tibial aiming device angle settings can affect the obliquity of the tunnel aperture and cause iatrogenic injury to the anterior meniscal roots. Caution should be exercised clinically to avoid iatrogenic injury to both the anterior meniscal roots while reaming tibial tunnels during ACL reconstructions.

Meniscal allograft transplantation: how should we be doing it? A systematic review

PURPOSE

We undertook a systematic review to assess a number of the technical aspects of meniscal allograft transplantation (MAT) that have not been covered in other reviews. Specific variables studied included the indications for MAT, graft fixation method, rehabilitation protocols, outcome scores, and definition of failure.

METHODS

We performed a systematic literature review of the PubMed, EMBASE, and Cochrane databases to determine the outcomes of meniscal transplantation at greater than 2 years postoperatively. PRISMA (Preferred Reporting for Systematic Reviews and Meta-Analyses) guidelines were followed with a PRISMA checklist. The search was completed on January 5, 2014.

RESULTS

These queries returned 629 results from which 41 articles were identified as meeting the inclusion criteria. No studies in this review were randomized or controlled.

CONCLUSIONS

MAT is a worthwhile procedure, with evidence that it provides pain relief and improved function, and good results reported in mid- to long-term studies. The procedure should be considered only in a patient with localized pain and a stable (or stabilized) and well-aligned (or realigned) knee. The controversial areas studied in this review include the following: there is no evidence to support fixation with either bone plugs or soft tissue; there is no standardized rehabilitation program, but it appears that full weight bearing by 6 weeks is not detrimental; and a clear and uniform definition of failure and use of consistent outcome scores would aid future reporting and analysis of the results of meniscal transplantation.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II to IV studies.

Resorbable collagen scaffolds for the treatment of meniscus defects: a systematic review

PURPOSE

The purpose of this study was to evaluate the clinical and structural outcomes after resorbable collagen meniscus scaffold implantation through a systematic review of the published literature.

METHODS

A systematic search of both the PubMed and Embase databases was undertaken to identify all studies that reported clinical and/or structural outcomes after resorbable collagen meniscus scaffold implantation for the treatment of defects involving either the medial or lateral meniscus. Extracted data included study characteristics; surgical methods and rehabilitation protocols; objective outcomes; and preoperative and postoperative subjective outcome scores including Lysholm, Tegner, International Knee Documentation Committee, and visual analog scale scores.

RESULTS

Thirteen studies were included in this review. There were 10 Level IV studies, 2 Level II studies, and 1 Level I study with follow-up intervals ranging from 3 months to 12.5 years. With a few exceptions, the study designs used in each study generally followed those which had been previously performed. Substantial differences in rehabilitation protocols and concomitant procedures were noted that may have had an effect on overall clinical outcomes. Objective findings were mostly consistent and typically showed minimal degenerative changes on postoperative radiographs, decreased signal intensity of the scaffold over time on magnetic resonance imaging, the presence of meniscus-like tissue at second-look arthroscopy, and good integration of new tissue as evidenced by histologic analysis of biopsy specimens. Most studies reported satisfactory clinical outcomes, and most patients showed substantial improvements in comparison with mean preoperative baseline values.

CONCLUSIONS

On the basis of this systematic review, implantation of resorbable collagen scaffolds for the treatment of meniscus defects provides satisfactory clinical and structural outcomes in most cases. There is evidence that collagen meniscus scaffold implantation provides superior clinical outcomes when compared with partial meniscectomy alone.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I, II, and IV studies.

Overexpression of TGF-β via rAAV-Mediated Gene Transfer Promotes the Healing of Human Meniscal Lesions Ex Vivo on Explanted Menisci

BACKGROUND

Direct application of therapeutic gene vectors derived from the adeno-associated virus (AAV) might be beneficial to improve the healing of meniscal tears.

PURPOSE

To test the ability of recombinant AAV (rAAV) to overexpress the potent transforming growth factor-β (TGF-β) in primary cultures of human meniscal fibrochondrocytes, in human meniscal explants, and in experimental human meniscal lesions as a new tool to enhance meniscal repair.

STUDY DESIGN

Controlled laboratory study.

METHODS

The effects of the candidate treatment on the proliferative and metabolic activities of meniscal cells were monitored in vitro for up to 21 days and in situ in intact and injured human menisci for up to 15 days using biochemical, immunohistochemical, histological, and histomorphometric analyses.

RESULTS

Efficient production of TGF-β via rAAV was achieved in vitro and in situ, both in the intact and injured meniscus. Application of the rAAV TGF-β vector stimulated the levels of cell proliferation and matrix synthesis (type I collagen) compared with control gene transfer in all systems tested, especially in situ in regions of poor healing capacity and in sites of meniscal injury. No adverse effects of the candidate treatment were observed at the level of osseous differentiation, as tested by immunodetection of type X collagen. Most remarkably, a significant reduction of the amplitude of meniscal tears was noted after TGF-β treatment, an effect that was associated with increased expression levels of the α-smooth muscle actin contractile marker.

CONCLUSION

Overexpression of TGF-β via rAAV gene transfer is capable of modulating the reparative activities of human meniscal cells, allowing for the healing of meniscal lesions by convenient injection in sites of injury.

CLINICAL RELEVANCE

Direct gene-based approaches using rAAV have strong potential to develop new therapeutic options that aim at treating human meniscal defects.