Autologous minced cartilage repair for chondral and osteochondral lesions of the knee joint demonstrates good postoperative outcomes and low reoperation rates at minimum five-year follow-up.

PURPOSE: Minced cartilage is a one-step, autologous procedure with promising short-term results. The aim of the present study was to evaluate mid-term results in a patient cohort with chondral and osteochondral lesions in the knee joint treated with minced cartilage. METHODS: From 2015 through 2016, a total of 34 consecutive patients were treated with a single-step, autologous minced cartilage for knee chondral and osteochondral lesions. Numeric analogue scale (NAS) for pain and knee function were obtained prior to surgery and at 12, 24 and 60 months postoperatively. Secondary outcomes, including Lysholm score, Tegner activity score, and the International Knee Documentation Committee (IKDC) score, were recorded at final follow-up. MRI examinations of patients with unplanned radiological follow-up were analysed using the MOCART (Magnetic Resonance Observation of Cartilage Repair Tissue) score. RESULTS: A total of 28 patients (44.1% females, age at surgery: 29.5 ± 11.5 years) were available at a mean follow-up of 65.5 ± 4.1 months. Mean defect size was 3.5 ± 1.8 cm2. NAS for pain decreased from a median of 7 (range: 2-10) preoperatively to 2 (0-8) postoperatively. NAS knee function improved from a median of 7 (range: 2-10) to 3 (0-7) after five years, respectively. Satisfactory Lysholm (76.5 ± 12.5), IKDC (71.6 ± 14.8) and Tegner activity (4, range 3-9) scores were reported at final follow-up. Of all patients, 21(75%) and 19 (67.9%) reached or exceeded the PASS for the IKDC- and Lysholm score at final follow-up, respectively. The average overall MOCART 2.0 scores for all postoperatively performed MRIs (n = 23) was 62.3 ± 17.4. Four (14.2%) postoperative complications were directly linked to minced cartilage, one (3.5%) of which required revision surgery. CONCLUSION: One-step, autologous minced cartilage repair of chondral and osteochondral lesions of the knee without the necessity for subchondral bone treatment demonstrated good patient-reported outcomes, low complication rates, and graft longevity at mid-term follow-up. Minced cartilage represents a viable treatment option to more traditional cartilage repair techniques even in mid-term. LEVEL OF EVIDENCE: Level III.

Biologic principles of minced cartilage implantation: a narrative review.

Cartilage tissue has a very limited ability to regenerate. Symptomatic cartilage lesions are currently treated by various cartilage repair techniques. Multiple treatment techniques have been proposed in the last 30 years. Nevertheless, no single technique is accepted as a gold standard. Minced cartilage implantation is a newer technique that has garnered increasing attention. This procedure is attractive because it is autologous, can be performed in a single surgery, and is therefore given it is cost-effective. This narrative review provides an overview of the biological potential of current cartilage regenerative repair techniques with a focus on the translational evidence of minced cartilage implantation.

Is There a Scientific Rationale for the Refixation of Delaminated Chondral Flaps in Femoroacetabular Impingement? A Laboratory Study.

BACKGROUND: Debonding of the acetabular cartilage is a characteristic type of hip damage found in cam-type femoroacetabular impingement (FAI), which remains a treatment challenge. In addition to resection, refixation of these flaps using fibrin sealants has been recently suggested. However, there is only limited evidence available that the proposed refixation method results in sufficient viable cartilage formation to ensure long-term flap grafting and restored tissue function. QUESTIONS/PURPOSES: To determine the flap tissue characteristics that would justify refixation of delaminated chondral flaps with a fibrin sealant, we characterized (1) the extracellular matrix (ECM) of chondral flaps in terms of chondrocyte viability and distribution of ECM components and (2) the chondrogenic potential of resident cells to migrate into fibrin and produce a cartilaginous matrix. METHODS: Ten acetabular chondral flaps and three non-delaminated control cartilage samples were resected during surgery. Chondrocyte viability was quantified using a live-dead assay. To assess the ECM, histological staining of glycosaminoglycans, collagen II, and collagen I allowed the qualitative study of their distribution. The ability of chondrocytes to migrate out of the ECM was tested by encapsulating minced flap cartilage in fibrin gels and semi-quantitatively assessing the projected area of the gel covered with migrating cells. The potential of chondrocytes to produce a cartilaginous matrix was studied with a pellet assay, a standard three-dimensional culture system to test chondrogenesis. Positive controls were pellets of knee chondrocytes of age-matched donors, which we found in a previous study to have a good capacity to produce cartilage matrix. Statistical significance of controlled quantitative assays was determined by the Student's t-test with Welch's correction. RESULTS: The proportion of viable chondrocytes in flaps was lower than in nondelaminated cartilage (50% ± 19% versus 76 ± 6%; p = 0.02). Histology showed a disrupted ECM in flaps compared with nondelaminated controls, with the presence of fibrillation, a loss of glycosaminoglycan at the delaminated edge, collagen II throughout the whole thickness of the flap, and some collagen I-positive area in two samples. The resident chondrocytes migrated out of this disrupted ECM in all tested samples. However in pellet culture, cells isolated from the flaps showed a qualitatively lower chondrogenic potential compared with positive controls, with a clearly inhomogeneous cell and matrix distribution and an overall smaller projected area (0.4 versus 0.7 mm; p = 0.038). CONCLUSION: Despite the presence of viable chondrocytes with migration potential, the cells resided in a structurally altered ECM and had limited capacity to deposit ECM, leading us to question their capacity to produce sufficient ECM within the fibrin sealant for stable long-term attachment of such flaps. CLINICAL RELEVANCE: The characterization of delaminated cartilage in cam FAI patients suggests that the refixation strategy might be adversely influenced by the low level of ECM produced by the residing cells.

Clinical and radiographical ten years long-term outcome of microfracture vs. autologous chondrocyte implantation: a matched-pair analysis.

PURPOSE: To compare the clinical and radiographical long-term outcome of microfracture (MFX) and first-generation periosteum-covered autologous chondrocyte implantation (ACI-P). METHODS: All subjects (n = 86) who had been treated with knee joint ACI-P or microfracture (n = 76) with a post-operative follow-up of at least ten years were selected. Clinical pre- and post-operative outcomes were analyzed by numeric analog scale (NAS) for pain, Lysholm, Tegner, IKDC, and KOOS score. Radiographical evaluation was visualized by magnetic resonance imaging (MRI). Assessment of the regenerate quality was performed by the magnetic resonance observation of cartilage repair tissue (MOCART) and modified knee osteoarthritis scoring system (mKOSS). Relaxation time (RT) of T2 maps enabled a microstructural cartilage analysis. RESULTS: MFX and ACI of 44 patients (24 females, 20 males; mean age 38.9 ± 12.1 years) resulted in a good long-term outcome with low pain scores and significant improved clinical scores. The final Lysholm and functional NAS scores were significantly higher in the MFX group (Lysholm: MFX 82 ± 15 vs. ACI-P 71 ± 18 p = 0.027; NAS function: MFX 8.1 ± 3.5 vs. ACI-P 6.0 ± 2.5; p = 0.003). The MOCART score did not show any qualitative differences. KOSS analysis demonstrated that cartilage repair of small defects resulted in a significant better outcome. T2-relaxation times were without difference between groups at the region of the regenerate tissue. CONCLUSION: This study did not demonstrate coherent statistical differences between both cartilage repair procedures. MFX might be superior in the treatment of small cartilage defects.

Chondrocyte Culture Parameters for Matrix-Assisted Autologous Chondrocyte Implantation Affect Catabolism and Inflammation in a Rabbit Model.

Cartilage defects represent an increasing pathology among active individuals that affects the ability to contribute to sports and daily life. Cell therapy, such as autologous chondrocyte implantation (ACI), is a widespread option to treat larger cartilage defects still lacking standardization of in vitro cell culture parameters. We hypothesize that mRNA expression of cytokines and proteases before and after ACI is influenced by in vitro parameters: cell-passage, cell-density and membrane-holding time. Knee joint articular chondrocytes, harvested from rabbits (n = 60), were cultured/processed under varying conditions: after three different cell-passages (P1, P3, and P5), cells were seeded on 3D collagen matrices (approximately 25 mm³) at three different densities (2 × 105/matrix, 1 × 106/matrix, and 3 × 106/matrix) combined with two different membrane-holding times (5 h and two weeks) prior autologous transplantation. Those combinations resulted in 18 different in vivo experimental groups. Two defects/knee/animal were created in the trochlear groove (defect dimension: ∅ 4 mm × 2 mm). Four identical cell-seeded matrices (CSM) were assembled and grouped in two pairs: One pair giving pre-operative in vitro data (CSM-i), the other pair was implanted in vivo and harvested 12 weeks post-implantation (CSM-e). CSMs were analyzed for TNF-α, IL-1ß, MMP-1, and MMP-3 via qPCR. CSM-i showed higher expression of IL-1ß, MMP-1, and MMP-3 compared to CSM-e. TNF-α expression was higher in CSM-e. Linearity between CSM-i and CSM-e values was found, except for TNF-α. IL-1ß expression was higher in CSM-i at higher passage and longer membrane-holding time. IL-1ß expression decreased with prolonged membrane-holding time in CSM-e. For TNF-α, the reverse was true. Lower cell-passages and lower membrane-holding time resulted in stronger TNF-α expression. Prolonged membrane-holding time resulted in increased MMP levels among CSM-i and CSM-e. Cellular density was of no significant effect. We demonstrated cytokine and MMP expression levels to be directly influenced by in vitro culture settings in ACI. Linearity of expression-patterns between CSM-i and CSM-e may predict ACI regeneration outcome in vivo. Cytokine/protease interaction within the regenerate tissue could be guided via adjusting in vitro culture parameters, of which membrane-holding time resulted the most relevant one.

Clinical Trial and In Vitro Study for the Role of Cartilage and Synovia in Acute Articular Infection.

OBJECTIVE: Osteoarthritis is a long-term complication of acute articular infections. However, the roles of cartilage and synovia in this process are not yet fully understood. METHODS: Patients with acute joint infections were enrolled in a prospective clinical trial and the cytokine composition of effusions compared in patients with arthroplasty (n = 8) or with intact joints (n = 67). Cytokines and cell function were also analyzed using a human in vitro model of joint infection. RESULTS: Synovial IL-1ß levels were significantly higher in patients with arthroplasty (p = 0.004). Higher IL-1ß concentrations were also found in the in vitro model without chondrocytes (p < 0.05). The anti-inflammatory cytokines IL-4 and IL-10 were consistently expressed in vivo and in vitro, showing no association with the presence of cartilage or chondrocytes. In contrast, FasL levels increased steadily in vitro, reaching higher levels without chondrocytes (p < 0.05). Likewise, the viability of synovial fibroblasts (SFB) during infection was higher in the presence of chondrocytes. The cartilage-metabolism markers aggrecan and bFGF were at higher concentrations in intact joints, but also synthesized by SFB. CONCLUSIONS: Our data suggest an anti-inflammatory effect of cartilage associated with the SFBs' increased resistance to infections, which displayed the ability to effectively synthesize cartilage metabolites.The trial is registered with DRKS 00003536, MISSinG.

Posterior root tears of the lateral meniscus.

PURPOSE: To summarize and discuss the current knowledge on posterior lateral meniscus root tears. METHODS: A comprehensive review of the MEDLINE database was carried out to identify relevant articles using different keywords (e.g. "meniscus root", "root tear", "meniscus avulsion", "radial tear" and "lateral meniscus"). The reference lists of the reviewed articles were searched for additional relevant articles. RESULTS: Posterior lateral meniscus root tears are found in 7-12% of patients with a tear of the anterior cruciate ligament (ACL). Biomechanical studies have found an increase in lateral compartment contact pressure of approximately 50% after creation of a posterior lateral meniscus root tear. There is some evidence that the biomechanical consequences of these injuries are significantly influenced by the presence and integrity of the meniscofemoral ligaments. Clinical studies have found encouraging results after repair of posterior lateral meniscus root tears. Whether root repair can prevent the development of osteoarthritis is currently unknown. CONCLUSION: A posterior lateral meniscus root tear is a clinical relevant but most likely underrecognized concomitant injury in patients with a tear of the ACL. This article may support clinicians in diagnosing and treating this unique type of meniscus tear. LEVEL OF EVIDENCE: V.

Prospective clinical trial of patients who underwent ankle arthroscopy with articular diseases to match clinical and radiological scores with intra-articular cytokines.

OBJECTIVE: There is still a lack of reliable data on cytokine concentrations in the ankle and their value for prognosis. METHODS: In a prospective clinical trial, lavage fluids were collected from 49 patients with an arthroscopy of the ankle. The fluids were investigated by ELISA for cytokine levels. Clinical scores (FFI, AOFAS) were evaluated both pre-operatively and then again 12 months after surgery (n = 43, 88%). Radiological changes were noted with the Kellgren-Lawrence-Score (KLS) and the Ankle Osteoarthritis Scoring System (AOSS). Based on the difference between the pre- and postoperative clinical scores, two groups were defined according to whether they had benefited from the surgical therapy (Δ score ≥ 10) or not (Δ score < 10). RESULTS: The average clinical scores had improved to a statistically significant extent in the one-year follow-up (p < 0.01). BMP-2 (p = 0.02), IGF-1 (p = 0.04), BMP-7 (p = 0.01) and aggrecan (p = 0.04) showed significant correlations with pre-operative clinical and radiological scores (p = 0.02, p = 0.01, p = 0.01, p = 0.01). Furthermore, BMP-2 (p = 0.01), IGF-1/TPC (p = 0.03) and aggrecan (p = 0.01) correlated with scores after one year (p = 0.02, p = 0.01). High aggrecan concentrations were associated with a low clinical and a high radiological score at both time points, both indicating progress of cartilage degeneration in contrast to BMP-2 or IGF-1. Furthermore, MMP-13 concentrations were significantly higher in the non-benefit group (p = 0.02). CONCLUSION: BMP-2, IGF-1, aggrecan and MMP-13 seem to be involved in the degenerative process of cartilage in the ankle joint. Additionally, high synovial MMP-13 concentrations indicate a worse clinical outcome.

Evaluation and analysis of graft hypertrophy by means of arthroscopy, biochemical MRI and osteochondral biopsies in a patient following autologous chondrocyte implantation for treatment of a full-thickness-cartilage defect of the knee.

Graft hypertrophy represents a characteristic complication following autologous chondrocyte implantation (ACI) for treatment of cartilage defects. Although some epidemiological data suggest that incidence is associated with first-generation ACI using autologous chondrocyte implantation, it has also been reported in other technical modifications of ACI using different biomaterials. Nevertheless, it has not been described in autologous, non-periosteum, implant-free associated ACI. In addition, little is known about histological and T2-relaxation appearance of graft hypertrophy. The present case report provides a rare case of extensive graft hypertrophy following ACI using an autologous spheres technique with clinical progression over time. Detailed clinical, MR tomographic and histological evaluation has been performed, which demonstrates a high quality of repair tissue within the hypertrophic as well as non-hypertrophic transplanted areas of the repair tissue. No expression of collagen type X (a sign of chondrocyte hypertrophy), only slight changes of the subchondral bone and a nearly normal cell-matrix ratio suggest that tissue within the hypertrophic area does not significantly differ from intact and high-quality repair tissue and therefore seems not to cause graft hypertrophy. This is in contrast to the assumption that histological hypertrophy might cause or contribute to an overwhelming growth of the repair tissue within the transplantation site. Data presented in this manuscript might contribute to further explain the etiology of graft hypertrophy following ACI.

Influence of extremely low frequency, low energy electromagnetic fields and combined mechanical stimulation on chondrocytes in 3-D constructs for cartilage tissue engineering.

Articular cartilage, once damaged, has very low regenerative potential. Various experimental approaches have been conducted to enhance chondrogenesis and cartilage maturation. Among those, non-invasive electromagnetic fields have shown their beneficial influence for cartilage regeneration and are widely used for the treatment of non-unions, fractures, avascular necrosis and osteoarthritis. One very well accepted way to promote cartilage maturation is physical stimulation through bioreactors. The aim of this study was the investigation of combined mechanical and electromagnetic stress affecting cartilage cells in vitro. Primary articular chondrocytes from bovine fetlock joints were seeded into three-dimensional (3-D) polyurethane scaffolds and distributed into seven stimulated experimental groups. They either underwent mechanical or electromagnetic stimulation (sinusoidal electromagnetic field of 1 mT, 2 mT, or 3 mT; 60 Hz) or both within a joint-specific bioreactor and a coil system. The scaffold-cell constructs were analyzed for glycosaminoglycan (GAG) and DNA content, histology, and gene expression of collagen-1, collagen-2, aggrecan, cartilage oligomeric matrix protein (COMP), Sox9, proteoglycan-4 (PRG-4), and matrix metalloproteinases (MMP-3 and -13). There were statistically significant differences in GAG/DNA content between the stimulated versus the control group with highest levels in the combined stimulation group. Gene expression was significantly higher for combined stimulation groups versus static control for collagen 2/collagen 1 ratio and lower for MMP-13. Amongst other genes, a more chondrogenic phenotype was noticed in expression patterns for the stimulated groups. To conclude, there is an effect of electromagnetic and mechanical stimulation on chondrocytes seeded in a 3-D scaffold, resulting in improved extracellular matrix production.

Association between intraarticular cytokine levels and clinical parameters of osteochondritis dissecans in the ankle.

BACKGROUND: Reliable data about in vivo regulation of cytokines in osteochondritis dissecans (OCD) of the ankle are still missing. Disease-specific regulation patterns were hypothesized. METHODS: 28 patients with a mean age of 30.7 ± 14.8 years undergoing an arthroscopy of the ankle because of OCD were prospectively included in a clinical trial. Lavage fluids were analyzed by ELISA for levels of aggrecan, BMP-2, BMP-7, IGF-1, IGF-1R, bFGF, endoglin, MMP-13, and IL-1ß. Additionally, clinical parameters and scores (FFI, CFSS, AOFAS) were evaluated and supplemented by the Kellgren Lawrence Score (KLS) for conventional X-rays and the Ankle Osteoarthritis Scoring System (AOSS) for MRI. RESULTS: Grading of OCD lesions statistically significant increased with age and was higher in case of previously performed operations (p<0.03). A worse clinical function reflected by low AOFAS and CFSS scores or high FFI was associated with high grading of cartilage damage or OCD (p<0.03). Similarly, high radiological scores (KLS and AOSS) indicating progress of OA positively correlated with grading of cartilage damage and OCD. The concordance between the MRI and arthroscopic classification was overall moderate (κ=0.52). Biochemically, only IGF/IGF-1R levels were consistently negatively associated with OCD grading, ICRS score, FFI and KLS (p<0.05). Correlation data is supported by post hoc statistics. CONCLUSIONS: Radiological and clinical parameters in association with synovial IGF-1/IGF-1R levels indicated an increasing joint degeneration with rising OCD stage. TRIAL REGISTRATION: German Clinical Trials Register DRKS00000365, 11/03/2008.

Biochemical characterization of early osteoarthritis in the ankle.

PURPOSE: Reliable data about in vivo regulation of cytokines in early ankle osteoarthritis (OA) are still missing. METHODS: 49 patients with a mean age of 33 ± 14 years undergoing an arthroscopy of the ankle with different stages of chronic OA were prospectively included in a clinical trial. Lavage fluids were analyzed by ELISA. Additionally, clinical parameters and scores (FFI, CFSS, and AOFAS) were evaluated and supplemented by the Kellgren Lawrence Score (KLS) and the ankle osteoarthritis scoring system (AOSS). RESULTS: ICRS grading of cartilage damage, previous operations, and duration of complains were strong indicators for OA progress and showed correlations to age, clinical scores, validated KLS, and AOSS (P < 0.04). Systemic and intraarticular inflammatory parameters were low in all patients. Biochemically, aggrecan and BMP-7 positively indicated OA with statistically significant associations with duration of symptoms, FFI, AOFAS, and KLS (P < 0.04). In contrast, BMP-2 levels showed statistically significant negative correlations to aggrecan or BMP-7 concentrations, which is in line with the negative association with ICRS score and KLS and the positive correlation with FFI (P < 0.03). CONCLUSIONS: We were able to identify different key markers of OA in the ankle as aggrecan, BMP-7, and BMP-2, offering starting points for new ways in diagnostics and interventional strategies.

Particulate cartilage under bioreactor-induced compression and shear.

PURPOSE: Our aim was to explore the effect of varying in vitro culture conditions on general chondrogenesis of minced cartilage (MC) fragments. METHODS: Minced, fibrin-associated, bovine articular cartilage fragments were cultured in vitro within polyurethane scaffold rings. Constructs were maintained either free swelling for two or four weeks (control), underwent direct mechanical knee-joint-specific bioreactor-induced dynamic compression and shear, or they were maintained free swelling for two weeks followed by two weeks of bioreactor stimulation. Samples were collected for glycosaminoglycan (GAG)/DNA quantification; collagen type I, collagen type II, aggrecan, cartilage oligomeric matrix protein (COMP), proteoglycan-4 (PRG-4) messenger RNA (mRNA) analysis; histology and immunohistochemistry. RESULTS: Cellular outgrowth and neomatrix formation was successfully accomplished among all groups. GAG/DNA and collagen type I mRNA were not different between groups; chondrogenic genes collagen type II, aggrecan and COMP revealed a significant downregulation among free-swelling constructs over time (week two through week four). Mechanical loading was able to maintain chondrogenic expression with significantly stronger expression at long-term time points (four weeks) in comparison with four-week control. Histology and immunohistochemistry revealed that bioreactor culture induced stronger cellular outgrowth than free-swelling constructs. However, weaker collagen type II and aggrecan expression with an increased collagen type I expression was noted among this outgrowth neotissue. CONCLUSIONS: The method of MC culture is feasible under in vitro free-swelling and dynamic loading conditions, simulating in vivo posttransplantation. Mechanical stimulation significantly provokes cellular outgrowth and long-term chondrogenic maturation at the mRNA level, whereas histology depicts immature neotissue where typical cartilage matrix is expected.

Simultaneous avulsion fracture of the posterior medial and posterior lateral meniscus root: a case report and review of the literature.

Injuries of the meniscus roots are increasingly recognized as a serious knee joint pathology. An avulsion fracture of the meniscus root is a rare variant of this injury pattern. In this article, a case of a traumatic simultaneous avulsion fracture of both the posterior medial and posterior lateral meniscus root associated with a tear of the anterior cruciate ligament is presented. Both avulsion fractures were treated by indirect arthroscopic transtibial pullout fixation of the bony fragment. Based on the findings of our literature review, root avulsion fractures seem to be more common in young male patients after an acute trauma to the knee joint.

Response of Articular Cartilage to Hyperosmolar Stress: Report of an Ex Vivo Injury Model.

BACKGROUND: Physiological 0.9% saline is commonly used as an irrigation fluid in modern arthroscopy. There is a growing body of evidence that a hyperosmolar saline solution has chondroprotective effects, especially if iatrogenic injury occurs. PURPOSE: To (1) corroborate the superiority of a hyperosmolar saline solution regarding chondrocyte survival after mechanical injury and (2) observe the modulatory response of articular cartilage to osmotic stress and injury. STUDY DESIGN: Controlled laboratory study. METHODS: Osteochondral explants were isolated from bovine stifle joints and exposed to either 0.9% saline (308 mOsm) or hyperosmolar saline (600 mOsm) and then damaged with a sharp dermatome blade to attain a confined full-thickness cartilage injury site, incubated in the same fluids for another 3 hours, and transferred to chondropermissive medium for further culture for 1 week. Chondrocyte survival was assessed by confocal imaging, while the cellular response was evaluated over 1 week by relative gene expression for apoptotic and inflammatory markers and mediator release into the medium. RESULTS: The full-thickness cartilage cut resulted in a confined zone of cell death that mainly affected superficial zone chondrocytes. Injured samples that were exposed to hyperosmolar saline showed less expansion of cell death in both the axial (P < .007) and the coronal (P < .004) plane. There was no progression of cell death during the following week of culture. Histological assessment revealed an intact cartilage matrix and normal chondrocyte morphology. Inflammatory and proapoptotic genes were upregulated on the first days postexposure with a notable downregulation toward day 7. Mediator release into the medium was concentrated on day 3. CONCLUSION: This in vitro cartilage injury model provides further evidence for the chondroprotective effect of a hyperosmolar saline irrigation fluid, as well as novel data on the capability of articular cartilage to quickly regain joint homeostasis after osmotic stress and injury. CLINICAL RELEVANCE: Raising the osmolarity of an irrigating solution may be a simple and safe strategy to protect articular cartilage during arthroscopic surgery.

Comparison of Minced Cartilage Implantation with Autologous Chondrocyte Transplantation in an In Vitro Inflammation Model.

The current gold standard to treat large cartilage defects is autologous chondrocyte transplantation (ACT). As a new surgical method of cartilage regeneration, minced cartilage implantation (MCI) is increasingly coming into focus. The aim of this study is to investigate the influence of chondrogenesis between isolated and cultured chondrocytes compared to cartilage chips in a standardized inflammation model with the proinflammatory cytokine TNFα. Articular chondrocytes from bovine cartilage were cultured according to the ACT method to passage 3 and transferred to spheroid culture. At the same time, cartilage was fragmented (<1 mm3) to produce cartilage chips. TNFα (20 ng/mL) was supplemented to simulate an inflammatory process. TNFα had a stronger influence on the passaged chondrocytes compared to the non-passaged ones, affecting gene expression profiles differently between isolated chondrocytes and cartilage chips. MCI showed less susceptibility to TNFα, with reduced IL-6 release and less impact on inflammation markers. Biochemical and histological analyses supported these findings, showing a greater negative influence of TNFα on the passaged pellet cultures compared to the unpassaged cells and MCI constructs. This study demonstrated the negative influence of TNFα on chondrogenesis in a chondrocyte spheroid culture and cartilage fragment model. Passaged chondrocytes are more sensitive to cytokine influences compared to non-passaged cells and chondrons. This suggests that MCI may have superior regeneration potential in osteoarthritic conditions compared to ACT. Further investigations are necessary for the translation of these findings into clinical practice.

Mid- and long-term efficacy of the arthroscopic patellar release for treatment of patellar tendinopathy unresponsive to nonoperative management.

PURPOSE: The purpose of this study was to evaluate the mid- and long-term efficacy of the arthroscopic patellar release (APR) in a representative number of competitive athletes. METHODS: This prospective study included 35 competitive athletes who underwent APR for treatment of chronic refractory patellar tendinopathy. The minimum follow-up period was 24 months. Preoperatively and at follow-up, we measured the Swedish Victorian Institute of Sport Assessment for Patella (VISA-P) and modified Blazina score for assessment of functional outcome. The patients rated their subjective knee function (0% to 100%) and maximum pain during exercise on a visual analog scale (0 to 10 points). We inquired about time required for full return to sports. RESULTS: Thirty athletes (27 male individuals, 3 female individuals) were available for clinical examination after a mean follow-up period of 4.4 years (σ = 3.0 years). The follow-up rate was 30 of 35 (86%). Mean age at surgery was 27.6 years (σ = 7.4). The mean VISA-P score improved from 57.3 (σ = 11.4) to 95.1 (σ = 8.2) and the mean Blazina score improved from 4.0 (σ = 0.8) to 0.3 (σ = 0.7). Average subjective knee function improved from 48.8% (σ = 18.5%) to 90.5% (σ = 9.8%). The mean pain level decreased from 5.7 (σ = 1.1) to 0.6 (σ = 1.2%). All changes were significant (P < .01). Twenty-three (76.7%) athletes were able to perform sports at previous levels without any symptoms. The mean time required for full return to sports was 4.4 months (1.5 to 12.0 months; σ = 3.3). Less pronounced symptoms recurred in 3 (10%) athletes. CONCLUSIONS: After APR, 97% of patients obtained excellent or good functional outcomes with a mean follow-up of 4.4 years. Three of 4 athletes achieved asymptomatic previous sports levels, returning to full sports at an average of 4.4 months. Symptoms partially recurred in 10% of participants. LEVEL OF EVIDENCE: Level IV: prospective therapeutic case series.

The Validity of Motion Capture Analysis System against the Gold Standard Long-Standing Radiography in the Measurement of Lower Extremity Alignment.

Motion capture analysis (MCA) has the advantage of providing a static and dynamic leg axis analysis without radiation. Nevertheless, there is a lack of evidence regarding the accuracy of this technique. To test whether mechanical femorotibial axis angle (MAA) measurement recorded with a non-invasive MCA system is equal to the gold standard static long-standing full-leg radiographs (LSX) and if the degree of malalignment or other parameters (BMI, body mass, height, age) influence the accuracy, a total of 102 consecutive patients were examined using LSX and MCA. Static as well as all gait motion phases at 3 km/h were analyzed regarding the difference between the two angles. There was no statistical difference for MAA between LSX (MAArad) and MCA (MAAstat) (p = 0.091). There was a strong correlation (rs = 0.858, p < 0.001) between the two methods. The highest accuracy was detected for values of standing MCA. Also, the gait MCA values showed strong correlation with LSX but weaker correlation compared to standing MCA (initial swing rs = 0.549; terminal stance rs = 0.815; p < 0.001). BMI, body mass, and height did not influence the accuracy of MCA. MCA enables frontal alignment analysis with high accuracy and without the side effect of radiation.

Early clinical and structural results after autologous chondrocyte transplantation at the glenohumeral joint.

BACKGROUND: The purpose of the study was to report early functional and radiographic results of a small series of patients who underwent autologous chondrocyte transplantation-collagen membrane seeding (ACT-Cs) for focal chondral defects of the shoulder. METHODS: The outcome of 4 consecutive male patients (mean age, 29.3 ± 6.2 years; range, 21-36 years) who underwent ACT-Cs for treatment of large symptomatic glenohumeral cartilage defects was retrospectively evaluated with clinical and radiographic measures at a mean of 41.3 ± 24.9 months (range, 11-71 months) after surgery. The evaluation included a visual analog scale for pain, the Constant score, the American Shoulder and Elbow Surgeons shoulder index, the Rowe score, and a satisfaction scale. Magnetic resonance imaging evaluation was performed according to the Magnetic Resonance Observation of Cartilage Repair Tissue scoring system. RESULTS: There were 3 humeral full-thickness cartilage defects (each 6.0 cm(2)) and 1 glenoid full-thickness cartilage defect (2.0 cm(2)). The mean postoperative visual analog scale score (0.3 of 10), the mean unweighted Constant score (83.3 ± 9.9), and the mean American Shoulder and Elbow Surgeons index (95.3 ± 8.1) were representative of satisfactory shoulder function. The Magnetic Resonance Observation of Cartilage Repair Tissue score was indicative of satisfactory defect coverage with signs of fibrocartilaginous repair tissue. CONCLUSIONS: Autologous chondrocyte transplantation at the glenohumeral joint is a remote option for young adults with symptomatic, isolated, large-diameter cartilage lesions. Potential complications as a result of the open approach and 2-step procedure have to be considered carefully. Long-term data, larger patient populations, and randomized studies are required to determine the potential for chondrocyte transplantation techniques to be standard procedure for treatment of symptomatic, large-diameter, full-thickness cartilage defects in the glenohumeral joint.

Autologous Minced Cartilage Implantation for Arthroscopic One-Stage Treatment of Osteochondritis Dissecans of the Elbow.

This Technical Note describes the full arthroscopic one-stage treatment of high-grade osteochondritis dissecans of the humeral capitellum of the elbow joint by means of minced cartilage implantation.