The role of autologous bone grafting in matrix-associated autologous chondrocyte implantation at the knee: Results from the German Cartilage Registry (KnorpelRegister DGOU).

PURPOSE: To investigate whether concomitant autologous bone grafting adversely affects clinical outcome and graft survival after matrix-associated autologous chondrocyte implantation (M-ACI). METHODS: The present study examines registry data of patients who underwent M-ACI with or without autologous bone grafting for large-sized chondral or osteochondral defects. Propensity score matching was performed to exclude potential confounders. A total of 215 patients with similar baseline characteristics were identified. Clinical outcome was assessed at the time of surgery and at 6, 12, 24, 36 and 60 months using the Knee Injury and Osteoarthritis Outcome Score (KOOS). KOOS change, clinical response rate, KOOS subcomponents and failure rate were determined. RESULTS: Patients treated with M-ACI and autologous bone grafting achieved comparable clinical outcomes compared with M-ACI alone. At 24 months postoperatively, the patient-reported outcome (PRO) of patients treated with M-ACI and autologous bone grafting was even significantly better as measured by KOOS (74.9 ± 18.8 vs. 79.2 ± 15.4; p = 0.043). However, the difference did not exceed the minimal clinically important difference (MCID). In patients with M-ACI and autologous bone grafting, a greater change in KOOS relative to baseline was observed at 6 (9.3 ± 14.7 vs. 15.0 ± 14.7; p = 0.004) and 12 months (12.6 ± 17.2 vs. 17.7 ± 14.6; p = 0.035). Overall, a high clinical response rate was observed in both groups at 24 months (75.8% vs. 82.0%; p = n.s.). The estimated survival at the endpoint of reoperation for any reason was 82.1% (SD 2.8) at 8.4 years for isolated M-ACI and 88.7% (SD 2.4) at 8.2 years for M-ACI with autologous bone grafting (p = 0.039). CONCLUSIONS: Even in the challenging cohort of large osteochondral defects, the additional treatment with autologous bone grafting leads to remarkably good clinical outcomes in patients treated with M-ACI. In fact, they tend to benefit more from surgery, have lower revision rates and achieve clinical response rates earlier. Subchondral bone management is critical to the success of M-ACI and should be addressed in the treatment of borderline defects. LEVEL OF EVIDENCE: Level III.

Long-Term Patient Outcomes for Treatment of Difficult Osteochondral Lesions of the Talus with Particulated Juvenile Allograft Cartilage Implantation ± Calcaneal Autograft: A Cohort Study.

BACKGROUND: Osteochondral lesions of the talus (OCLT) are common injuries that can be difficult to treat. To date, long-term patient reported outcome measures (PROMs) of patients with particulated juvenile allograft cartilage implantation with or without calcaneal autograft have not been compared. METHODS: Thirteen patients with difficult to treat OCLTs underwent arthroscopic-assisted implantation of particulated juvenile allograft cartilage (DeNovo NT®) with or without autogenous calcaneal bone grafting by a single surgeon. Calcaneal bone graft use was determined by lesion size > 150 mm2 and/or deeper than 5 mm. Patients were evaluated using physical examination, patient interviews, and PROMs. RESULTS: When comparing patients in regards to calcaneal bone graft implantation, no difference in age, BMI, pre-operative PROMs, or follow-up was noted, however, calcaneal bone graft patients did have a significantly larger lesion size (188.5 ± 50.9 vs. 118.7 ± 29.4 mm2 respectively; p value = 0.027). VAS and FAAM ADL scores during final follow-up improvement did not significantly differ between cohorts. The FAAM Sports score improved significantly more for the DeNovo alone group compared to the bone graft cohort (p value = 0.032). The AOFAS score improvement did not differ between cohorts (p value = 0.944), however, the SF-36 PCS improved significantly more for the DeNovo alone group compared to the bone graft cohort (p value = 0.038). No intraoperative/perioperative complications were observed with calcaneal bone grafting. CONCLUSION: While patients followed over the course of ~ 8 years after implantation of particulated juvenile allograft cartilage (DeNovo NT®) with/without autogenous calcaneal bone graft had positive post-operative PROMs, patients without calcaneal bone graft had significantly greater improvement in functional outcome scores. Whether these differences are due to graft incorporation or larger lesion size is unclear. LEVEL OF EVIDENCE: III, retrospective cohort study.

In vivo rAAV-mediated human TGF-ß overexpression reduces perifocal osteoarthritis and improves osteochondral repair in a large animal model at one year.

OBJECTIVE: Osteoarthritis (OA) is a serious consequence of focal osteochondral defects. Gene transfer of human transforming growth factor beta (hTGF-ß) with recombinant adeno-associated virus (rAAV) vectors offers a strategy to improve osteochondral repair. However, the long-term in vivo effects of such rAAV-mediated TGF-ß overexpression including its potential benefits on OA development remain unknown. METHOD: Focal osteochondral defects in minipig knees received rAAV-lacZ (control) or rAAV-hTGF-ß in vivo. After one year, osteochondral repair and perifocal OA were visualized using validated macroscopic scoring, ultra-high-field MRI at 9.4 T, and micro-CT. A quantitative estimation of the cellular densities and a validated semi-quantitative scoring of histological and immunohistological parameters completed the analysis of microarchitectural parameters. RESULTS: Direct rAAV-hTGF-ß application induced and maintained significantly improved defect filling and safranin O staining intensity and overall cartilage repair at one year in vivo. In addition, rAAV-hTGF-ß led to significantly higher chondrocyte densities within the cartilaginous repair tissue without affecting chondrocyte hypertrophy and minimized subarticular trabecular separation. Of note, rAAV-hTGF-ß significantly improved the adjacent cartilage structure and chondrocyte density and reduced overall perifocal OA development after one year in vivo. CONCLUSIONS: rAAV-hTGF-ß treatment improves long-term osteochondral repair and delays the progression of perifocal OA in a translational model. These findings have considerable potential for targeted molecular approaches to treat focal osteochondral defects.

Satisfactory patient-reported outcomes in patients treated with impaction bone grafting and autologous matrix-induced chondrogenesis for osteochondral knee defects.

PURPOSE: Osteochondral knee defects usually affect young, active patients and may alter knee biomechanics and progressively lead to joint degeneration. Various treatment options exist with autologous, impaction bone grafting in combination with autologous matrix-induced chondrogenesis (BG-AMIC) being a less-expensive, one-step, promising option. The purpose of this study is to evaluate the clinical and radiological mid-term outcomes of large osteochondral lesions treated with BG-AMIC, identify a possible correlation between the two and report postoperative complications and reoperation rate. METHODS: A retrospective analysis of 25 patients treated with the BG-AMIC technique for knee osteochondral lesions was performed. Patients were assessed using the following PROMs: the IKDC, the KOOS and the Lysholm score, the Tegner activity scale and a patient acceptable symptom state (PASS). The EQ-5D-5L score was used to assess health-related quality of life. Radiological assessment was performed using the MOCART 2.0 score on a 3 T MRI. RESULTS: At a mean of 3.8 (± 0.8)-year follow-up, all functional scores increased significantly (p < 0.005) when compared to the preoperative baseline. IKDC increased from 44.5 (± 15.9) to 81.4 (± 14.7), KOOS from 41.5 (± 16.1) to 91.6 (± 11.6) and Lysholm from 54.4 (± 23) to 95.2 (± 5.5) (p < 0.005). The EQ-5D-5L score also revealed a significant improvement [59.9 (± 25) to 93.4 (± 10.2), p < 0.005]. Mean Tegner score reached pre-injury levels. The PASS was positive in 100% of patients. The minimum clinically important difference was reached in all PROMs except for the KOOS Sports subscale. There were no re-operations. Morphological evaluation of the repair tissue using the MOCART 2.0 score revealed a mean total score of 52.8 (± 30.5). A statistically significant, positive correlation was found between the MOCART 2.0 score and the IKDC score, the KOOS ADL subscale and the EQ-5D-5L (p < 0.05). CONCLUSION: BG-AMIC is a safe and reliable option for treating deep, knee osteochondral lesions, providing a statistically significant and clinically important improvement in patient-reported outcomes. No complications were noticed, and no re-operations were performed after the procedure. A moderate positive correlation between the MOCART 2.0 score and the IKDC, KOOS ADL and EQ-5D-5L was noticed. However, this correlation is not necessarily clinically relevant, and excellent clinical results can be expected even in patients with low MOCART scores. LEVEL OF EVIDENCE: III.

Efficacy and safety of autologous chondrocyte implantation for osteochondral defects of the talus: a systematic review and meta-analysis.

INTRODUCTION: Studies have reported various effects of autologous chondrocyte implantation (ACI) on osteochondral defects of the talus. Therefore, to assess the effectiveness of ACI for osteochondral defects of the talus, we used the meta-analytic approach. MATERIALS AND METHODS: Electronic databases PubMed, Embase, and the Cochrane Library were systematically searched to identify eligible studies from their inception until November 2020. The random-effects model was used to calculate the incidence of success rate and American Orthopaedic Foot and Ankle Society (AOFAS) score for patients after ACI treatment. Subgroup analyses were also conducted based on age, technique, indication, size, and follow-up duration. RESULTS: For the final meta-analysis, we selected 23 case series studies with a total of 458 patients with osteochondral defects of the talus. Overall, after ACI for patients with osteochondral defects of the talus, we noted that the incidence of success rate was 89% (95% confidence interval (95% CI) 85%-92%; P < 0.001). Moreover, after ACI for patients with osteochondral defects of the talus, the AOFAS score was 86.33 (95% CI 83.33-89.33; P < 0.001). Subgroup analysis showed that the AOFAS score after ACI is significantly different when stratified by the mean age of the patients (P = 0.006). CONCLUSIONS: This study revealed that the use of ACI could provide a relatively high success rate and improve the AOFAS score for patients with osteochondral defects of the talus, which should be recommended in clinical practice.

Stem cell-based therapies for temporomandibular joint osteoarthritis and regeneration of cartilage/osteochondral defects: a systematic review of preclinical experiments.

OBJECTIVES: The aim of this systematic review was to assess the effects of stem cell-based therapies on the treatment of Temporomandibular Joint Osteoarthritis (TMJ-OA) and the regeneration of cartilage/osteochondral defects. METHODS: Data on preclinical studies evaluating the effectiveness of stem cell-based therapies for treating Temporomandibular Disorders (TMDs) were extracted from PubMed, Web of Science, and Cochrane Library and the grey literature by three independent reviewers. A manual search was performed in the databases, the reference list of review studies, and relevant journals in the field. Compliance with the ARRIVE guidelines was evaluated for quality assessment. SYRCLE's risk of bias tool for animal experimental studies was assessed to define internal validity. RESULTS: After applying the inclusion and exclusion criteria, 10 studies were included in the qualitative synthesis. Regardless of cell origin, stem cell-based therapeutic approaches induced protective, anti-inflammatory, and chondroregenerative potential in the treatment of TMJ-OA. Regeneration of the cartilage layer on the surface of the condyle was achieved when stem cells were directly flushed into the defect or when delivered within a carrier. CONCLUSION: Stem cell-based therapies may be considered a promising approach for the treatment of TMJ-OA and for the regeneration of full-thickness cartilage and osteochondral defects in the TMJ. Human studies shall be performed to validate these results found in animals.

Arthroscopic accessibility of the first metatarsophalangeal joint for osteochondral defects of the metatarsal head by two-portal technique - comparing joint distraction and plantarflexion.

BACKGROUND: Several techniques and approaches for first metatarsophalangeal (MTP1) joint arthroscopy have been reported, where joint accessibility plays a key role. This study aimed to evaluate differences in arthroscopic accessibility of the first metatarsal head (MTH1) comparing non-invasive distraction and maximum plantarflexion in a two-portal approach. METHODS: Forty fresh-frozen lower leg specimens were included and divided into a distraction group (D-group) and a plantarflexion group (PF-group). A two-portal technique (1.9 mm-30°-scope) was used for arthroscopy, maximum reach at the MTH1 was marked. Following arthroscopy, specimens were dissected and examined for iatrogenic injuries. The reached area at the chondral surface was pinned and accessibility calculated. RESULTS: Accessibility of the MTH1 was 58.03 % ± 13.64 (D-group) and 55.93 % ± 10.30 (PF-group, p = 0.51). The dorsomedial hallucal nerve was injured in one specimen (2.5 %). CONCLUSION: Maximum plantarflexion showed no difference in arthroscopic MTP1 joint accessibility compared to non-invasive distraction in a two-portal approach. During dorsomedial portal placement, the dorsomedial hallucal nerve is at risk for iatrogenic injury.

AMIC for traumatic focal osteochondral defect of the talar shoulder: a 5 years follow-up prospective cohort study.

BACKGROUND: Autologous Matrix-Induced Chondrogenesis (AMIC) is addressed to osteochondral defects of the talus. However, evidence concerning the midterm efficacy and safety of AMIC are limited. This study assessed reliability and feasibility of AMIC at 60 months follow-up. We hypothesize that AMIC leads to good clinical outcome at midterm follow-up. METHODS: Surgeries were approached with an arthrotomy via malleolar osteotomy. A resorbable porcine I/III collagen membrane (Chondro-Gide®, Geistlich Pharma AG, Wolhusen, Switzerland) was used. Patients were followed at 24 and 60 months. The primary outcome of interest was to analyse the Foot Function Index (FFI), and the subscale hindfoot of the American Orthopaedic Foot and Ankle Score (AOFAS). Complications such as failure, revision surgeries, graft delamination, and hypertrophy were also recorded. The secondary outcome of interest was to investigate the association between the clinical outcome and patient characteristics at admission. RESULTS: Data from 19 patients were included. The mean age at admission was 47.3 ± 13.2 years, and the mean BMI 24.1 ± 4.9 kg/m2. 53% (10 of 19 patients) were female. At a mean of 66.2 ± 11.6 months, the FFI decreased at 24-months follow-up of 22.5% (P = 0.003) and of further 1.3% (P = 0.8) at 60-months follow-up. AOFAS increased at 24-months follow-up of 17.2% (P = 0.003) and of further 3.4 (P = 0.2) at 60-months follow-up. There were two symptomatic recurrences within the follow-up in two patients. There was evidence of a strong positive association between FFI and AOFAS at baseline and the same scores last follow-up (P = 0.001 and P = 0.0002, respectively). CONCLUSION: AMIC enhanced with cancellous bone graft demonstrated efficacy and feasibility for osteochondral defects of the talus at five years follow-up. The greatest improvement was evidenced within the first two years. These results suggest that clinical outcome is influenced by the preoperative status of the ankle. High quality studies involving a larger sample size are required to detect seldom complications and identify prognostic factors leading to better clinical outcome. LEVEL OF EVIDENCE: II, prospective cohort study.

Suppressing PLCγ1 enhances osteogenic and chondrogenic potential of BMSCs.

Phosphatidylcholine-specific phospholipase Cγ1 (PLCγ1) is involved in regulating cell metabolism. However, little is known how PLCγ1 directs BMSC differentiation. Here, we investigated the role of PLCγ1 in rat BMSC differentiation into osteoblasts and chondrocytes. The results of Alizarin red and Alcian blue staining showed that PLCγ1 inhibitor U73122 significantly enhanced the mineralization capacity and proteoglycan deposition of BMSCs. The results of qPCR technique and Western blot analysis showed that long-term treatment of U73122 enhanced COL1A1 and OPG mRNA levels and Collagen 1A1, BMP2, and p-Smad1/5/9 protein levels and that short-term treatment of U73122 enhanced COL2A1 and SOX9 mRNA levels and Collagen 2, SOX9, Aggrecan, TGF-ß3, and p-Smad2/3 protein levels. Decreased p-mTOR and p-P38 contributed to enhanced osteogenic potentials of BMSCs and increased p-P38 contributed to enhanced chondrogenic potentials of BMSCs. The scaffold transplantation with U73122+BMSC was more efficacious than BMSC alone for osteochondral defect repair in a rat model. Therefore, suppressing PLCγ1 could improve the capacity to effectively use BMSCs for cell therapy of osteochondral defect.

Enhancing Osteochondral Tissue Regeneration of Gellan Gum by Incorporating Gallus gallus var Domesticus-Derived Demineralized Bone Particle.

Treatment for the osteochondral defects (ODs) is more challenging nowadays that needs to be addressed by developing alternative bone tissue engineering materials. Gellan gum (GG) is a widely used natural polysaccharide in the field of tissue engineering (TE) and regenerative medicine due to its versatile properties. There are many reports about the successful application of GG in cartilage tissue engineering and guiding bone formation. Functional coatings and porous composite materials have been introduced in next-generation materials for treating OD, whereas osteoconductive materials, such as demineralized bone particle (DBP) or bone derivatives, are used. However, modification of porosity, biocompatibility, cell proliferation, and mechanical properties is needed. DBP can activate human mesenchymal stem cells to differentiate into osteoblast cells. In this chapter, the potential application of GG with DBP in different combinations was reviewed, and the best suitable combinations were selected and further studied in small animal models for the soft and hard tissue engineering applications; also its application in the osteochondral integration fields were briefly discussed.

Arthroscopic lift, drill, fill and fix (LDFF) is an effective treatment option for primary talar osteochondral defects.

PURPOSE: The purpose of this study was to describe the mid-term clinical and radiological results of a novel arthroscopic fixation technique for primary osteochondral defects (OCD) of the talus, named the lift, drill, fill and fix (LDFF) technique. METHODS: Twenty-seven ankles (25 patients) underwent an arthroscopic LDFF procedure for primary fixable talar OCDs. The mean follow-up was 27 months (SD 5). Pre- and post-operative clinical assessments were prospectively performed by measuring the Numeric Rating Scale (NRS) of pain in/at rest, walking and when running. Additionally, the Foot and Ankle Outcome Score (FAOS) and the Short Form-36 (SF-36) were used to assess clinical outcome. The patients were radiologically assessed by means of computed tomography (CT) scans pre-operatively and 1 year post-operatively. RESULTS: The mean NRS during running significantly improved from 7.8 pre-operatively to 2.9 post-operatively (p = 0.006), the NRS during walking from 5.7 to 2.0 (p < 0.001) and the NRS in rest from 2.3 to 1.2 (p = 0.015). The median FAOS at final follow-up was 86 for pain, 63 for other symptoms, 95 for activities of daily living, 70 for sport and 53 for quality of life. A pre- and post-operative score comparison was available for 16 patients, and improved significantly in most subscores. The SF-36 physical component scale significantly improved from 42.9 to 50.1. Of the CT scans at 1 year after surgery, 81% showed a flush subchondral bone plate and 92% of OCDs showed union. CONCLUSION: Arthroscopic LDFF of a fixable primary talar OCD results in excellent improvement of clinical outcomes. The radiological follow-up confirms that fusion of the fragment is feasible in 92%. This technique could be regarded as the new gold standard for the orthopedic surgeon comfortable with arthroscopic procedures. LEVEL OF EVIDENCE: Prospective case series, therapeutic level IV.

Focal metallic inlay resurfacing prosthesis in articular cartilage defects: short-term results of 118 patients and 2 different implants.

BACKGROUND: The goal of this study was to share our experience with two different inlay metallic implants in the treatment of knee cartilage defects and to analyze their effects on functional scores. METHODS: This retrospective study included 118 patients operated on for focal full-thickness knee cartilage lesions, who were treated with a focal metallic inlay resurfacing prosthesis. A cobalt-chromium (Co-Cr) resurfacing implant was applied to 73 patients with a knee chondral lesion, and a biosynthetic implant was applied to 45. All patients were evaluated preoperatively and postoperatively using the KOOS, VAS, and Tegner activity scores. RESULTS: The group with the Co-Cr-resurfacing implant showed a significantly greater improvement (p < 0.001) in the Tegner and VAS scores at the 2-year follow-up examination. The KOOS scores were similar in both groups. Median patient age was similar in both groups. All patients had a follow-up of at least 2 years. The preoperative and postoperative scores were compared and significant improvements (p < 0.001) were observed. The biosynthetic implant had a higher revision rate. In the univariate analysis, age and type of implant were significantly associated with revision surgery. In the multivariate Cox-regression analysis model, the type of implant was significantly associated with revision surgery. CONCLUSION: All the patients operated with the above-mentioned implants showed significant improvements in pain and activity scores. Despite the overall good clinical results, 17% of patients with a biosynthetic implant and > 6% of patients with Co-Cr-resurfacing implant required revision surgery. Age and implant type were the main risk factors associated with revision.

Melt electrowriting onto anatomically relevant biodegradable substrates: Resurfacing a diarthrodial joint.

Three-dimensional printed hydrogel constructs with well-organized melt electrowritten (MEW) fibrereinforcing scaffolds have been demonstrated as a promising regenerative approach to treat small cartilage defects. Here, we investige how to translate the fabrication of small fibre-reinforced structures on flat surfaces to anatomically relevant structures. In particular, the accurate deposition of MEW-fibres onto curved surfaces of conductive and non-conductive regenerative biomaterials is studied. This study reveals that clinically relevant materials with low conductivities are compatible with resurfacing with organized MEW fibres. Importantly, accurate patterning on non-flat surfaces was successfully shown, provided that a constant electrical field strength and an electrical force normal to the substrate material is maintained. Furthermore, the application of resurfacing the geometry of the medial human femoral condyle is confirmed by the fabrication of a personalised osteochondral implant. The implant composed of an articular cartilage-resident chondroprogenitor cells (ACPCs)-laden hydrogel reinforced with a well-organized MEW scaffold retained its personalised shape, improved its compressive properties and supported neocartilage formation after 28 days in vitro culture. Overall, this study establishes the groundwork for translatingMEWfrom planar and non-resorbable material substrates to anatomically relevant geometries and regenerative materials that the regenerative medicine field aims to create.

A Comparison of Outcomes of Revision Surgical Options for the Treatment of Failed Bulk Talar Allograft Transfer: A Systematic Review.

Talar bulk osteochondral allograft transplantation is a useful treatment strategy for large, uncontained osteochondral lesions of talus. Complications and high revision rates from osteochondral talar allograft transfer can be common. Talar graft failure is a devastating complication that results from failure of allograft incorporation within the host bone and subsequent resorption and sometimes subsidence can occur. Treatment options and outcomes for graft failure have rarely been reported. The purpose of this study is to evaluate treatment options and their outcomes for treating talar allograft failure. A systematic review was completed to find all reports of salvage treatments for talar graft failure and outcomes of these reports were analyzed. Eleven studies involving a total of 522 ankles, in 520 patients, met the inclusion criteria. The allograft failure rate was 11.5% in these studies with a reoperation rate of 18.9%. With limited reports, satisfactory outcomes for treatment of graft failure with ankle arthrodesis were 77.3%, 50% for revision allograft procedures, and 50% for total ankle arthroplasty. Considering the large failure rate and reoperation rate for bulk talar allograft transplantations, superior revision, and salvage options are needed. More prospective cohort studies focusing on consistent and standard outcome measures are needed to further assess revision options for failed talar allograft procedures.

Mid-term results after treatment of complex talus osteochondral defects with HemiCAP implantation.

BACKGROUND: HemiCAP for complex osteochondral defects (OCDs) in talus has been on the market since 2008. Few follow-up studies exist. Patients with complex OCDs were followed for up to 81 months. METHODS: 31 consecutive patients were assessed preoperatively and at final follow-up, mean 50 months. All patients were treated with the HemiCAP®, Arthrosurface Inc., USA inlay. Inclusion criteria were complex OCDs of the medial or lateral talus dome. RESULTS: All outcome measures i.e. AOFAS, FAOS and NRS improved significantly. 71.8 % of the cohort were employed preoperatively. At final follow up 87.5% were employed. No revisions of the HemiCAP was performed, but 41,9% had supplementary surgery. 1 patient had a superficial infection otherwise no complications were found. Preoperative and final follow-up x-rays were analysed. CONCLUSIONS: Mid-term results after HemiCAP talus are good. Patient information and selection is mandatory due to the high numbers of additional surgeries following the HemiCap implantation.

Bone block augmentation from the iliac crest for treatment of deep osteochondral defects of the knee resembles biomechanical properties of the subchondral bone.

PURPOSE: Bone block augmentation from the iliac crest can be used for reconstruction of the osteochondral unit to restore the underlying subchondral bone upon restoration of the cartilaginous layer via matrix-induced chondrocyte transplantation. To critically understand the successful restoration of the defect, biomechanical and histological analysis of the implanted bone blocks is required. The aim of the study was to analyse the ability of the bone block technique to restore huge bone defects by mimicking the physiological subchondral zone. METHODS: The experiments were performed using lateral femoral condyles and iliac crest bone grafts from the same cadavers (n = 6) preserved using the Thiel method. CT scans were made to evaluate bone pathology. Bone mineral density of all specimens was evaluated in the femoral head prior to testing. A series of tests were conducted for each pair of specimens. A static compression test was performed using an electro dynamic testing machine with maximal strength and failure behavior analyzed. Biomechanical tests were performed in the medial-lateral direction for iliac crest and for femoral condyles with and without removal of the cartilage layer. Histological analysis was performed on decalcified specimens for comparison of the condyle at lesion site and the graft. RESULTS: No significant difference in failure load could be found for iliac crest (53.3-180.5 N) and femoral condyle samples upon cartilage removal (38.5-175.1 N) (n.s.). The femoral condyles with an intact cartilage layer showed significantly higher loads (118.3-260.4N) compared to the other groups indicating that native or regenerated cartilage can further increase the failure load (p < 0.05). Bone mineral density significantly influenced failure load in all study groups (p < 0.05). Histological similarity of the cancellous bone in the femoral condyle and in the iliac crest was observed. However, within the subchondral zone, there was a higher density of sponge like organized trabeculae in the bone samples from the iliac crest. Tide mark was only detected at the osteochondral interface in femoral condyles. CONCLUSION: This study demonstrated that, bone blocks derived from the iliac crest allow a biomechanical appropriate and stable restoration of huge bony defects by resembling the subchondral zone of the femoral condyle. Therefore, bone augmentation from the iliac crest combined with matrix-induced autologous chondrocyte transplantation seems to be a reasonable method to treat these challenging injuries.

Arthroscopic treatment of osteochondral knee defects with resorbable biphasic synthetic scaffold: clinical and radiological results and long-term survival analysis.

PURPOSE: The aim of our study is to evaluate the long-term results in patients treated with a fully arthroscopic TruFit system for osteochondral lesions of the femoral condyle, analyzing the clinical and radiological outcomes, survival rate, complications, and correlations. METHODS: The study included all patients treated with the TruFit system with a full-thickness focal lesion of the knee cartilage (grade IV according to the ICRS classification), entirely arthroscopically with a minimum follow-up of five years. All patients were evaluated clinically prior to surgery (T0) and at two consecutive follow-ups (T1 36.4 ± 17.03 months and T2 101.63 ± 19.02 months), using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Hospital for Special Surgery Score (HSS). At the final follow-up, the magnetic resonance imaging (MRI) was evaluated by two orthopaedists using the magnetic resonance observation of cartilage repair tissue (MOCART) score. RESULTS: The sample was formed of 21 patients, of which 14 were males (67%) and 7 females (33%), with a mean age of 51.29 ± 10.70. Of the 21 patients, two underwent prosthetic knee replacement at 24 and 65 months, respectively. At T0, the HSS and the KOOS score were, respectively, 60.71 ± 11.62 and 57.71 ± 6.11. For both clinical values, a significant improvement was noted between T0 and T1 (p < 0.05) and between T0 and T2 (p < 0.05). At the final follow-up, the MOCART value was found to be 45.78 ± 5.27. CONCLUSIONS: The study results highlighted the safety and potential of the arthroscopic TruFit system procedure, which offered a good clinical outcome with stable results at long-term follow-up although we found no correlations between the MRI and clinical results.

[Research progress on osteochondral tissue engineering].

Osteochondral defects is a common clinical joint disease. The complexity of cartilage-bone interface and the poor self-repair capacity of cartilage are both reasons for current relatively limited clinical treatments. The introduction of tissue engineering provides a new treatment method for osteochondral repair. This paper reviews three main elements of cartilage-bone tissue engineering: seed cell source and culture method, cytokines regulation and synergistic effect, and scaffold components and type. We mainly focused on current status quo and future progress of cartilage-bone repair scaffolds. This paper provides some reference for the further development of osteochondral tissue engineering.

Nanoparticles-Based Systems for Osteochondral Tissue Engineering.

Osteochondral lesions represent one of the major causes of disabilities in the world. These defects are due to degenerative or inflammatory arthritis, but both affect the articular cartilage and the underlying subchondral bone. Defects from trauma or degenerative pathology frequently cause severe pain, joint deformity, and loss of joint motion. Osteochondral defects are a significant challenge in orthopedic surgery, due to the cartilage complexity and unique structure, as well as its exposure to high pressure and motion. Although there are treatments routinely performed in the clinical practice, they present several limitations. Tissue engineering can be a suitable alternative for osteochondral defects since bone and cartilage engineering had experienced a notable advance over the years. Allied with nanotechnology, osteochondral tissue engineering (OCTE) can be leveled up, being possible to create advanced structures similar to the OC tissue. In this chapter, the current strategies using nanoparticles-based systems are overviewed. The results of the studies herein considered confirm that advanced nanomaterials will undoubtedly play a crucial role in the design of strategies for treatment of osteochondral defects in the near future.

Surgical Treatment Paradigms of Ankle Lateral Instability, Osteochondral Defects and Impingement.

Ankle sprain is amongst the most frequent musculoskeletal injuries, particularly during sports activities. Chronic ankle instability (CAI) resulting from an ankle sprain might have severe long-lasting consequences on the ankle joint. Despite the fact that most patients will respond favourably to appropriate conservative treatment, around 20% will develop symptomatic CAI with sense of giving away and recurrent sprains leading to functional impairment. "Classical" surgical repair by Brostrom-like surgery in one of its many modifications has achieved good results over the years. Recently, major advances in surgical techniques have enabled arthroscopic repair of ankle instability with favourable outcome while also enabling the treatment of other concomitant lesions: loose bodies, osteochondral defects (OCDs) or ankle impingement. Moreover, when the tissue remnant does not permit a repair technique, anatomic reconstruction by means of using a free graft has been developed. In many cases, OCDs occur as a consequence of CAI. However, traumatic and non-traumatic aetiologies have been described. There is no evidence favouring any surgical treatment over another concerning OCDs. Considering lower cost and limited aggression, microfracture is still the most frequent surgical approach. Herein, the authors describe their algorithm in the treatment of these conditions. Similarly, anterior or posterior impingement might be linked with CAI. These are clinical syndromes based on clinical diagnosis which are currently managed arthroscopically upon failure of conservative treatment.