Hymovis MO.RE. in the treatment of knee and ankle chondropathy in elite athletes: preliminary results of the CHAMPS (Cohort study about HYADD4-G Administration for Pain relief on Soccer players) prospective clinical study.

OBJECTIVE: This study evaluated single intra-articular injections of Hymovis MO.RE., a hyaluronic acid hexadecyl derivative (HYADD4-G), to manage post-traumatic or degenerative knee or ankle chondropathy in professional soccer players. PATIENTS AND METHODS: Twenty-five players affected by knee (n = 12) or ankle (n = 13) chondropathy were prospectively enrolled and treated by two single Hymovis MO.RE. (32 mg/4 ml) injections at the beginning of the football season (V0, baseline) and at mid-season (V1, 19-20 weeks thereafter), and were followed-up until the end of the season (V2, after further 19-20 weeks). Knee cases were evaluated using the 2000 IKDC knee subjective examination form and the modified Lysholm scoring system. Ankle cases were evaluated using the American Orthopaedic Foot Ankle Society (AOFAS) ankle-hindfoot score. Patients were also evaluated using a VAS Likert scale and a four-category scale recording both the patient's and the doctor's assessment on joint mobility in degrees and overall treatment efficacy. Adverse events, patient withdrawals and local reaction to injections were also assessed. RESULTS: In knee patients, the 2000 IKDC subjective score improved from 46.8 ± 11.4 at V0 to 83.1 ± 12.5 at V2. Their modified Lysholm score improved from 58.8 ± 8.9 at V0 to 90.6 ± 8.3 at V2. In the ankle patients, the AOFAS score improved from 52.2 ± 5.6 at V0 to 96.4 ± 4.5 at V2. VAS Likert values and subjective evaluations improved at V1 and were maintained at V2. No side effects were recorded. CONCLUSIONS: A single Hymovis MO.RE. (32 mg/4 ml) intra-articular injection, repeated after 19-20 weeks, may be a viable option to improve symptoms and function in professional soccer players suffering from knee and ankle chondropathy.

Postoperative malrotation of humerus shaft fracture causes degeneration of rotator cuff and cartilage.

We hypothesized that postoperative malrotation of humeral shaft fractures can alter the bio-mechanical environment of the shoulder; thus, rotator cuff and cartilage degeneration could be induced. Therefore, we designed an animal experiment to evaluate the impact of malrotation deformities after minimally invasive surgery for humeral fractures on the rotator cuff and cartilage, which has rarely been described in previous studies. Twenty-four New Zealand white rabbits were randomly divided into the sham control group (A), negative control group (B) and malrotated group (C). A sham operation with surgical exposure alone was performed in group A. Humeral shaft osteotomy was performed in Group B and C. In Group B, the fractures were fixed in situ with plate -screw system. While in Group C, iatrogenic rotational deformity was created after the proximal end of the fracture being internally rotated by 20 degrees and then subsequently fixed. The animals with bone healing were sacrificed for pathological and biochemical examination. In group C, the modified Mankin scale for cartilage pathology evaluation and the modified Movin scale for tendon both showed highest score among groups with statistical significance (P < 0.05); Disordered alignment and proportion of collagen I/III of rotator cuff were confirmed with picrosirius red staining; Transmission electron microscopy also showed ultrastructural tendon damage. Immunohistochemistry showed that both MMP-1 and MMP-13 expression were significantly higher in group C than groups A and B(P < 0.05). Minimally invasive techniques for humerus shaft fracture might be cosmetically advantageous, but the consequent postoperative malrotation could increase the risk of rotator cuff and cartilage degeneration. This conclusion is supported here by primary evidence from animal experiments.

Diagnosis and Management of Articular Cartilage and Meniscus Pathology in the Posterior Cruciate Ligament-Injured Knee.

Posterior cruciate ligament (PCL) injuries commonly occur in association with participation in sporting or recreational activities or due to a direct trauma. Cartilage and meniscal lesions are prevalent in PCL-injured knees with increasing likelihood and severity based on extent and duration of trauma to the knee. As such, comprehensive diagnostics should be performed to ascertain all related pathology, and patients should be thoroughly educated regarding treatment options, likely sequelae including posttraumatic osteoarthritis, and associated outcomes. Treatments should address the joint as an organ, ensuring stability, alignment, and functional tissue restoration are optimized by the most efficient and effective means possible. Compliance with patient- and procedure-specific postoperative management protocols is critical for optimizing successful outcomes for these complex cases. The objectives of this review article are to highlight the likelihood and importance of osteochondral and meniscal pathology in the PCL-injured knee, and to provide the best current evidence regarding comprehensive evaluation and management for PCL-injured knees with cartilage and/or meniscal comorbidities.

High kinesiophobia and pain catastrophizing in people with articular cartilage defects in the knee and associations with knee function.

PURPOSE: The purpose of this study was to evaluate the extent to which individuals with knee articular cartilage defects (ACDs) have kinesiophobia and pain catastrophizing, and how these psychological factors relate to self-reported knee outcomes. METHODS: Thirty-five individuals seeking surgical consultation for an ACD in the knee confirmed with 3.0T MRI and 18 controls without history of knee injury participated in the study. Kinesiophobia was measured with the Tampa Scale of Kinesiophobia (TSK), and scored using the modified 11-item (TSK-11) methods. Pain catastrophizing was measured with the Pain Catastrophizing Scale (PCS). Data were analyzed using descriptive statistics, independent t-tests, chi-squared tests and Spearman's correlation coefficients, as appropriate (α = 0.05). RESULTS: Participants with ACDs reported higher TSK-11 scores (median 27 [IQR 25-29]) and higher PCS scores (median 10 [IQR 4-18]) than controls (median TSK-11 16 [IQR 14-17], p < 0.001; median PCS 0 [IQR 0-9], p < 0.001). Within those with knee ACDs, higher TSK-11 scores were associated with worse knee pain, function on activities of daily living, sports/recreation, and knee-related quality of life scores (rho = -0.38 to -0.61). Higher pain catastrophizing was associated with worse function with activities of daily living and knee-related quality of life (rho = -0.37 to -0.40). CONCLUSIONS: Kinesiophobia and pain catastrophizing in people with knee ACDs were higher than controls. Higher kinesiophobia and pain catastrophizing were associated with worse function and quality of life. Further study of the impact of these psychological factors on outcomes and prognosis in people with knee ACDs is warranted.

Orientation anisotropy of quantitative MRI parameters in degenerated human articular cartilage.

Quantitative magnetic resonance (MR) relaxation parameters demonstrate varying sensitivity to the orientation of the ordered tissues in the magnetic field. In this study, the orientation dependence of multiple relaxation parameters was assessed in cadaveric human cartilage with varying degree of natural degeneration, and compared with biomechanical testing, histological scoring, and quantitative histology. Twelve patellar cartilage samples were imaged at 9.4 T MRI with multiple relaxation parameters, including T1 , T2 , CW - T1ρ , and adiabatic T1ρ , at three different orientations with respect to the main magnetic field. Anisotropy of the relaxation parameters was quantified, and the results were compared with the reference measurements and between samples of different histological Osteoarthritis Research Society International (OARSI) grades. T2 and CW - T1ρ at 400 Hz spin-lock demonstrated the clearest anisotropy patterns. Radial zone anisotropy for T2 was significantly higher for samples with OARSI grade 2 than for grade 4. The proteoglycan content (measured as optical density) correlated with the radial zone MRI orientation anisotropy for T2 (r = 0.818) and CW - T1ρ with 400 Hz spin-lock (r = 0.650). Orientation anisotropy of MRI parameters altered with progressing cartilage degeneration. This is associated with differences in the integrity of the collagen fiber network, but it also seems to be related to the proteoglycan content of the cartilage. Samples with advanced OA had great variation in all biomechanical and histological properties and exhibited more variation in MRI orientation anisotropy than the less degenerated samples. Understanding the background of relaxation anisotropy on a molecular level would help to develop new MRI contrasts and improve the application of previously established quantitative relaxation contrasts.

Comparison of clinically used bilayer collagen membrane and trilayer collagen prototype fixation stability in chondral defects at the talus - An experimental human specimen study.

BACKGROUND: The purpose of this human specimen experimental study was to compare the fixation stability of clinically used bilayer collagen membrane with fibrin glue with trilayer collagen prototype without fibrin glue in chondral defects at the medial or lateral talar shoulder (both matrices from Geistlich Pharma AG, Wollhusen, Switzerland). METHODS: Eleven human specimens were used. The membranes were implanted in standardized chondral defects at the medial and lateral talar shoulder randomized. All tests were performed in load-control 15 kg. Range of motion ROM of each ankle was examined individually before testing. The average ROM was 10° dorsiflexion range 0°-20° and 30° plantarflexion range 20°-45°. 1,000 testing cycles with the defined ROM were performed. Two independent investigators, blinded to membrane and fixation type, visually assessed the membrane fixation integrity for peripheral detachment, area of defect uncovered, membrane constitution and delamination. RESULTS: The clinically used bilayer collagen membrane plus fibrin glue showed higher fixation stability than the trilayer prototype (all p < 0.05). No significant differences occurred between medial and lateral talar shoulder location (all p > 0.05). CONCLUSIONS: The fixation stability of the trilayer collagen prototype without fibrin glue is lower than of the clinically used bilayer membrane with fibrin glue in chondral defects at the medial and lateral talar shoulder in an experimental human specimen test. Clinical use of trilayer collagen prototype without fibrin glue has to be validated by clinical testing to evaluate if the lower stability of fixation is still sufficient.

The role of stromal cell-derived factor 1 on cartilage development and disease.

Stromal cell-derived factor 1 (SDF-1), also known as CXC motif chemokine ligand 12 (CXCL12), is recognized as a homeostatic cytokine with strong chemotactic potency. It plays an important role in physiological and pathological processes, such as the development of multiple tissues and organs, the regulation of cell distribution, and tumour metastasis. SDF-1 has two receptors, CXC chemokine receptor type 4 (CXCR4) and CXC chemokine receptor type 7 (CXCR7). SDF-1 affects the proliferation, survival, differentiation and maturation of chondrocytes by binding to CXCR4 on chondrocytes. Therefore, SDF-1 has been used as an exogenous regulatory target in many studies to explore the mechanism of cartilage development. SDF-1 is also a potential therapeutic target for osteoarthritis (OA) and rheumatoid arthritis (RA), because of its role in pathological initiation and regulation. In addition, SDF-1 shows potent capacity in the repair of cartilage defects by recruiting endogenous stem cells in a cartilage tissue engineering context. To summarize the specific role of SDF-1 on cartilage development and disease, all articles had been screened out in PubMed by May 30, 2020. The search was limited to studies published in English. Search terms included SDF-1; CXCL12; CXCR4; chondrocyte; cartilage; OA; RA, and forty-seven papers were studied. Besides, we reviewed references in the articles we searched to get additional relevant backgrounds. The review aims to conclude the current knowledge regarding the physiological and pathological role of SDF-1 on the cartilage and chondrocyte. More investigations are required to determine methods targeted SDF-1 to cartilage development and interventions to cartilage diseases.

Discoid Labral Meniscus Covering Two-Thirds of a Type C Glenoid: A Case Report.

BACKGROUND: Glenoid morphology and dysplasia have been extensively described in conjunction with shoulder arthritis. Dysplastic glenoids have a substantial inherent retroversion, a deficient posteroinferior rim, a short scapular neck, and an inferior inclination of the joint surface. The effect of dysplasia on fracture surgery has not been reported to the same extent. CASE PRESENTATION: A 65-year-old man presented with a proximal humeral fracture. The patient was scheduled for osteosynthesis. The head was deemed unrepairable at the time of surgery and the operative plan changed to replace the proximal humerus. A discoid meniscus-like labral extension covering two-thirds of the glenoid was encountered. This finding covered a dysplastic glenoid. The combination of a fracture and a dysplastic glenoid had not been accounted for and made the reconstruction more difficult. The patient received a reverse total shoulder arthroplasty after perioperative considerations regarding reconstruction. At the 2-month follow up, the patient had a satisfactory clinical outcome, with 90° of flexion and minimal residual pain. CONCLUSION: This case illustrates that elective disorders with dysplasia also present to the fracture team. Careful analysis of preoperative imaging should result in an operative plan taking unexpected findings into account.

The Benefit of Perineural Injection Treatment with Dextrose for Treatment of Chondromalacia Patella in Participants Receiving Home Physical Therapy: A Pilot Randomized Clinical Trial.

Introduction: Chondromalacia patella is the degeneration of articular cartilage on the posterior facet of the patella and may indicate the onset of osteoarthritis. Conservative management is the main treatment option, and surgical intervention is considered the last option in a small percentage of patients. Perineural Injection Treatment (PIT) is a recently developed treatment option that is directed adjacent to the peripheral nerves that are the source of pathology causing neurogenic inflammation and pain. Objective: The objective of this study was to evaluate the efficacy of PIT combined with a home physical therapy program in patients with a diagnosis of chondromalacia patella compared with a control group receiving physical therapy only. Methods: Two patient groups were involved in this randomized clinical trial. The first received PIT combined with physical therapy (PIT + PT group) and the second was managed with physical therapy alone (PT group). Both groups were indicated to follow a 6-week home therapy plan afterward. The Western Ontario and McMaster Osteoarthritis Index was used to assess the patients at baseline and 6 months after therapy interventions. Results: Fifty patients (38 women and 12 men, median age 54.7 ± 14.8 years) were included; sex distribution and age did not differ between groups. Both groups had chondromalacia grade II or III, but the degree of gonarthrosis did not differ significantly between groups. The PIT + PT group outperformed PT group for pain (7.3 ± 3.5 vs. 3.2 ± 2.9 points; p < 0.010), stiffness (3 ± 1.69 vs. 1.6 ± 1.5 points; p < 0.010), and functional capacity (23.2 ± 10.7 vs. 11.1 ± 8.9 points; p < 0.010). Conclusions: Compared with physical therapy alone, PIT plus physical therapy reduced pain and stiffness and restored functional capacity. ClinicalTrials.gov Register Number #NCT03515720.

Emerging pharmaceutical therapies for osteoarthritis.

The prevalence of osteoarthritis (OA) and the burden associated with the disease are steadily increasing worldwide, representing a major public health challenge for the coming decades. The lack of specific treatments for OA has led to it being recognized as a serious disease that has an unmet medical need. Advances in the understanding of OA pathophysiology have enabled the identification of a variety of potential therapeutic targets involved in the structural progression of OA, some of which are promising and under clinical investigation in randomized controlled trials. Emerging therapies include those targeting matrix-degrading proteases or senescent chondrocytes, promoting cartilage repair or limiting bone remodelling, local low-grade inflammation or Wnt signalling. In addition to these potentially disease-modifying OA drugs (DMOADs), several targets are being explored for the treatment of OA-related pain, such as nerve growth factor inhibitors. The results of these studies are expected to considerably reshape the landscape of OA management over the next few years. This Review describes the pathophysiological processes targeted by emerging therapies for OA, along with relevant clinical data and discussion of the main challenges for the further development of these therapies, to provide context for the latest advances in the field of pharmaceutical therapies for OA.

Degeneration alters the biomechanical properties and structural composition of lateral human menisci.

OBJECTIVE: Because the literature relating to the influence of degeneration on the viscoelasticity and tissue composition of human lateral menisci remains contradictory or completely lacking, the aim of this study was to fill these gaps by comprehensively characterising the biomechanical properties of menisci with regard to the degree of degeneration. DESIGN: Meniscal tissue from 24 patients undergoing a total knee replacement was collected and the degeneration of each region classified according to Pauli et al. For biomechanical characterisation, compression and tensile tests were performed. Additionally, the water content was determined and infrared (IR) spectroscopy was applied to detect changes in the structural composition, particularly of the proteoglycan and collagen content. RESULTS: With an increasing degree of degeneration, a significant decrease of the equilibrium modulus was detected, while simultaneously the water content and the hydraulic permeability significantly increased. However, the tensile modulus displayed a tendency to decrease with increasing degeneration, which might be due to the significantly decreasing amount of collagen content identified by the IR measurements. CONCLUSION: The findings of the current study may contribute to the understanding of meniscus degeneration, showing that degenerative processes appear to mainly worsen viscoelastic properties of the inner circumference by disrupting the collagen integrity.

Nonsurgical Management of Cartilage Defects of the Knee: Who, When, Why, and How?

The nonoperative practitioner managing individuals with cartilage defects should use a patient-centered, multifaceted approach that aims to individualize treatment to provide optimal benefit. These include addressing modifiable risk factors for disease progression and instituting interventions such as weight loss, nutrition, physical activity, and potentially regenerative medicine strategies. This review will focus on these nonoperative treatment strategies with a focus on when treatments are necessary, who will benefit from these approaches, why they are specifically appropriate, and, finally, how these treatments directly modify the structure of a patient's cartilage and resulting symptoms.

Clinical Application of the Basic Science of Articular Cartilage Pathology and Treatment.

The joint is an organ with each tissue playing critical roles in health and disease. Intact articular cartilage is an exquisite tissue that withstands incredible biologic and biomechanical demands in allowing movement and function, which is why hyaline cartilage must be maintained within a very narrow range of biochemical composition and morphologic architecture to meet demands while maintaining health and integrity. Unfortunately, insult, injury, and/or aging can initiate a cascade of events that result in erosion, degradation, and loss of articular cartilage such that joint pain and dysfunction ensue. Importantly, articular cartilage pathology affects the health of the entire joint and therefore should not be considered or addressed in isolation. Treating articular cartilage lesions is challenging because left alone, the tissue is incapable of regeneration or highly functional and durable repair. Nonoperative treatments can alleviate symptoms associated with cartilage pathology but are not curative or lasting. Current surgical treatments range from stimulation of intrinsic repair to whole-surface and whole-joint restoration. Unfortunately, there is a relative paucity of prospective, randomized controlled, or well-designed cohort-based clinical trials with respect to cartilage repair and restoration surgeries, such that there is a gap in knowledge that must be addressed to determine optimal treatment strategies for this ubiquitous problem in orthopedic health care. This review article discusses the basic science rationale and principles that influence pathology, symptoms, treatment algorithms, and outcomes associated with articular cartilage defects in the knee.

Cartilage damage at the time of anterior cruciate ligament reconstruction is associated with weaker quadriceps function and lower risk of future ACL injury.

PURPOSE: To determine whether articular cartilage damage noted at the time of primary anterior cruciate ligament reconstruction (ACLR) affects the likelihood of achieving ≥ 90% symmetry for isokinetic extension strength at 6 months after surgery or risk of recurrent ACL injury. METHODS: Five hundred and eight patients underwent primary ACLR and diagnostic arthroscopy. All identified cartilage lesions were graded using the Outerbridge system. All patients underwent isokinetic strength testing. The association between cartilage Outerbridge grade and a ≥ 90% Limb Symmetry Index (LSI) and recurrent ACL injury risk at mean 38.7 month follow-up (SD 31.8) was evaluated via multivariate regression analysis. RESULTS: Grade 2 or higher damage was present in 394 (77.5%) of patients, grade 3 or higher in 143 (28.1%) and grade 4 in 83 (16.4%) at time of ACLR. Ipsilateral ACLR graft rupture occurred in 31 (6.1%) of patients. Contralateral ACL injury occurred in 19 (3.7%). Patients with grade 2 or higher damage were significantly less likely to meet an LSI goal of ≥ 90% for fast (300°/s) isokinetic extension. There was no association with slow isokinetic extension. Cartilage lesion severity at or beyond grade 2 had a similar effect on isokinetic testing results regardless of compartment involvement or performance of microfracture. Patients with grade 2-4 cartilage damage were less likely to sustain a second ipsilateral ACL injury or a contralateral native ACL injury. CONCLUSIONS: Cartilage damage seen at time of ACL reconstruction is common and associated with lower likelihood of achieving ≥ 90% symmetry for isokinetic extension strength at 6 months after surgery. However, lower recurrent ACL injury rates are seen in patients with concurrent cartilage damage. These data may inform future clinical decisions regarding operative managment of recurrent ACL injuries. LEVEL OF EVIDENCE: III.

Autologous chondrocyte implantation for treatment of focal articular cartilage defects of the humeral head.

BACKGROUND: Autologous chondrocyte implantation (ACI) constitutes an established treatment option for cartilage defects of the knee joint. Experience in the shoulder, however, is limited, and the management of cartilage defects remains a challenge. The purpose of this study was to evaluate the results after ACI with 3-dimensional spheroids of human autologous matrix-associated chondrocytes in the shoulder. METHODS: Seven male patients (median age, 42.8 years [range, 18-55 years]) underwent ACI for symptomatic focal grade IV cartilage lesions of the humeral head by an open or arthroscopic approach. Clinical parameters (range of motion, visual analog scale score, Subjective Shoulder Value, Constant score, and American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form score) and osteoarthritis grades were assessed. Arthroscopic re-evaluation was additionally performed in 5 patients. RESULTS: After a median follow-up period of 32 months (range, 22-58 months), the median Subjective Shoulder Value was 95% (range, 70%-100%) compared with 60% (range, 30%-60%) preoperatively, the visual analog scale score was 0 at rest and was a median of 0 (range, 0-2) during exercise, the median Constant score was 95 points (range, 80-100 points), and the median American Shoulder and Elbow Surgeons score was 97 points (range, 90-100 points). The median preoperative size of the cartilage lesion was 3 cm2 (range, 2.3-4.5 cm2). Arthroscopically, complete coverage of the cartilage defect was observed in 4 cases whereas a circumferential residual defect of 0.25 cm2 was found in 1 patient. Grade I osteoarthritis (Samilson and Prieto classification) was observed in 2 cases. One patient had postoperative adhesive capsulitis and required revision surgery. CONCLUSION: ACI using 3-dimensional spheroids of human autologous matrix-associated chondrocytes for treatment of grade IV articular cartilage lesions of the humeral head achieves satisfactory clinical results during a short- to mid-term follow-up period and leads to successful defect coverage with only minor radiologic degenerative changes. In this case series, ACI proved to constitute a viable treatment in the shoulder joint. However, in consideration of the 2-stage surgical design and the cost intensiveness of this procedure, the indication is restricted to young and active symptomatic patients in our practice.

Effects of Controlling Abnormal Joint Movement on Expression of MMP13 and TIMP-1 in Osteoarthritis.

OBJECTIVE: Abnormal joint movement is associated with osteoarthritis (OA). Previous studies using the controlling abnormal joint movement (CAJM) model of OA reported delayed cartilage degeneration; however, none of them focused on gait performance and the localization of matrix metalloproteinase 13 (MMP13) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in chondrocytes. Therefore, we aimed to investigate the effect of controlling abnormal joint movement on gait performance and the localization of MMP13 and TIMP-1, using kinematic and histological analyses. DESIGN: Rats were assigned to 2 groups: anterior cruciate ligament transection (ACL-T) group and CAJM group (n = 5/group); contralateral hind limbs of ACL-T rats were designated as intact. After 1, 2, and 4 weeks, step length was analyzed, and after 2, 4, and 8 weeks, Safranin O-Fast Green staining and immunohistochemical staining for MMP13 and TIMP-1 were performed. RESULTS: Step length did not differ significantly between the groups. However, degeneration of articular cartilage was higher in the ACL-T group than in the intact group (P < 0.05). There was no significant difference in the CAJM group at all time points. Immunohistochemical analysis of the MMP13/TIMP-1 relationship revealed a significant increase in the expression ratio of MMP13 after 4 weeks in the ACL-T group compared to the CAJM group (P < 0.05). CONCLUSIONS: Controlling abnormal joint movement may reduce mechanical stress owing to kinematic elements of small articulation including joint instability and delayed cartilage degeneration, despite the lack of kinematic change in step length.

Determination of the Depth- and Time- Dependent Mechanical Behavior of Mouse Articular Cartilage Using Cyclic Reference Point Indentation.

Mouse models of osteoarthritis and cartilage degeneration are important and powerful tools for investigating the molecular mechanisms of the disease pathology. Because of the vast number of genetically modified mouse models that are available for research, the ability to use these models is particularly attractive for the mechanobiologic interactions in the pathogenesis of osteoarthritis. However, the very small scale of mouse articular cartilage, where the healthy tissue is only 80 µm in thickness, poses challenges in quantifying mechanical characteristics of the tissue. We introduce here a novel approach that combines experimental and analytical methods to quantify the nuanced mechanical changes during cartilage degeneration at this scale. Cyclic reference point indentation is used to directly test the murine articular cartilage to obtain the force-deformation and the phase-shift characteristics of the tissue. The cartilage zonal thicknesses are confirmed from histology. These data are then fitted to a parallel spring model to determine the depth-dependent tissue stiffness and modulus. Using this approach, we investigated the effects of trypsin degradation on the zonal mechanical behavior of mouse articular cartilage. We observe a decline of the superficial zone stiffness coupled with the loss of the superficial layer. Subsequent degradation by trypsin allowed the identification of middle- and deep- zone properties. Taken together, this approach can be a useful tool for understanding the disease mechanisms of cartilage homeostasis and degeneration, and for monitoring of therapies for osteoarthritis.

Transtibial fixation for medial meniscus posterior root tear reduces posterior extrusion and physiological translation of the medial meniscus in middle-aged and elderly patients.

PURPOSE: To investigate changes in meniscal extrusion during knee flexion before and after pullout fixation for medial meniscus posterior root tear (MMPRT) and determine whether these changes correlate with articular cartilage degeneration and short-term clinical outcomes. METHODS: Twenty-two patients (mean age 58.4 ± 8.2 years) diagnosed with type II MMPRT underwent open magnetic resonance imaging preoperatively, 3 months after transtibial fixation and at 12 months after surgery, when second-look arthroscopy was also performed. The medial meniscus medial extrusion (MMME) and the medial meniscus posterior extrusion (MMPE) were measured at knee 10° and 90° flexion at which medial meniscus (MM) posterior translation was also calculated. Articular cartilage degeneration was assessed using International Cartilage Research Society grade at primary surgery and second-look arthroscopy. Clinical evaluations included Knee Injury and Osteoarthritis Outcome Score, International Knee Documentation Committee subjective knee evaluation form, Lysholm score, Tegner activity level scale, and pain visual analogue scale. RESULTS: MMPE at 10° knee flexion was higher 12 months postoperatively than preoperatively (4.8 ± 1.5 vs. 3.5 ± 1.2, p = 0.01). MMPE at 90° knee flexion and MM posterior translation were smaller 12 months postoperatively than preoperatively (3.5 ± 1.1 vs. 4.6 ± 1.3, 7.2 ± 1.7 vs. 8.9 ± 2.0, p < 0.01). Articular cartilage degeneration of medial femoral condyle correlated with MMME in knee extension (r = 0.5, p = 0.04). All clinical scores significantly improved 12 months postoperatively. However, correlations of all clinical scores against decreased MMPE and increased MMME were not detected. CONCLUSIONS: MMPRT transtibial fixation suppressed the progression of MMPE and cartilage degeneration and progressed MMME minimally in knee flexion position at 1 year. However, in the knee extension position, MMME progressed and correlated with cartilage degeneration of medial femoral condyle. MMPRT transtibial fixation contributes to the dynamic stability of the MM in the knee flexion position. LEVEL OF EVIDENCE: IV.

Return to Sport and Outcomes After Concomitant Lateral Meniscal Allograft Transplant and Distal Femoral Varus Osteotomy.

PURPOSE: To evaluate the time and rate of return to sport (RTS), as well as outcomes, in young and active patients receiving concomitant lateral meniscal allograft transplantation (MAT) and distal femoral varus osteotomy (DFVO) for lateral meniscal deficiency and valgus malalignment. METHODS: This was a retrospective study of consecutive patients who underwent concomitant MAT and DFVO by a single surgeon. The exclusion criteria were any concomitant procedures other than cartilage restoration procedures for focal full-thickness cartilage defects of the lateral femoral condyle and less than 2 years of follow-up. At final follow-up, patients were asked to complete a subjective sports questionnaire, the Marx Activity Rating Scale, a visual analog scale (VAS), the Single Assessment Numeric Evaluation, and a satisfaction questionnaire. Changes in patient-reported outcome measures were assessed using nonparametric statistical testing. RESULTS: A total of 21 patients met the inclusion criteria, of whom 17 were included for analysis at an average follow-up of 7.5 years (range, 2.2-13.3 years). The average age at the time of surgery was 23.3 years (range, 16.9-36.2 years), and 76.5% of patients were female patients. The average VAS score decreased from 5.7 preoperatively to 2.6 postoperatively (P = .02). Of the 15 patients who participated in sports within 3 years prior to their surgical procedure, 14 (82.4%) returned to 1 or more sports at an average of 16.9 months (range, 6-36 months); however, only 46.7% were able to return to their preinjury level of participation or higher. Furthermore, 88.2% of patients reported being satisfied with their sport-related outcomes. Direct rates of sport-specific return were as follows: weightlifting, 100%; skiing, 100%; running, 66.7%; and basketball, 50%. CONCLUSIONS: In our study population, concomitant MAT and DFVO afforded a high rate of RTS at an average of 16.9 months postoperatively, as well as a significant decrease in VAS pain scores. These findings are essential to note when counseling patients receiving these procedures who wish to resume sports and physical activities so that they may expect an extensive recovery process before they can RTS. LEVEL OF EVIDENCE: Level IV, case series.