Osteochondral Grafts Research Articles

Osteochondral Autograft Transplantation for Symptomatic Full-thickness Patellar Cartilage Defects in Adolescents.

This study aimed to review the clinical, radiographic, and magnetic resonance imaging (MRI) outcomes of osteochondral autograft transplantation applied to patellar cartilage lesions of patients under 18 years of age. Data from nine consecutive patients were retrospectively analyzed for indications, preoperative complications, and clinical-radiographic outcomes. Patients were clinically evaluated using the Pedi-IKDC and Lysholm scores. In addition, return to sports and knee pain were assessed. MRI evaluation included an analysis of osteochondral graft integration using the magnetic resonance observation of cartilage repair tissue 2.0 score and radiographic classification of osteoarthritis using the Kellgren-Lawrence system. Nine patients (9 knees, 6 males) with a mean age of 14 years (SD: 1.7, range; 11 to 17y) were analyzed. Lesions were located on the medial facet (N=5), lateral facet (N=3), and central ridge of the patella (N=1). One or 2 cylindrical osteochondral grafts were transplanted, with a median diameter of 9mm (range: 8 to 10mm). The average lesion size was 102.9mm2. At a mean follow-up of 45.1 months (range: 23 to 117mo), the mean Pedi-IKDC score was 89.2 (SD: 9.8), and the Lysholm score was 94.4 (SD: 4.8). Patients returned to sports in an average of 7.3 months (SD: 2, range: 6 to 12mo). MRI of 8 patients showed osteochondral graft integration with a mean magnetic resonance observation of cartilage repair tissue 2.0 score of 86.9 (SD: 7, range: 80 to 100). Six knees showed Kellgren-Lawrence grade 0 joint space on radiographs, and 3 showed grade 1. Eight patients were asymptomatic at the last follow-up, and 1 reported occasional mild pain with intense physical activity. One patient developed arthrofibrosis, requiring arthroscopic lysis of adhesions and manipulation. Osteochondral autograft transplantation is a safe and effective technique for treating symptomatic patellar full-thickness chondral lesions in adolescents. Long-term follow-up studies will determine whether the affected area maintains structural and functional integrity over time. Level IV-therapeutic study.

An Evidence-Based Update on Fixation Procedures for Acute and Chronic Osteochondral Lesions of the Talus

Osteochondral lesions of the talus (OLT) involve the subchondral bone and the overlying articular cartilage. Various surgical treatments for these lesions are available, such as bone marrow stimulation (BMS), autologous osteochondral grafting, and fixation of an osteochondral fragment. Treatment choice depends on the condition of the lesion, which includes lesion size, morphology, location, and the presence of cysts. Among the surgical procedures available to date, in situ fixation of the osteochondral fragment has the advantage of restoring the articular surface while preserving the native hyaline cartilage and its subchondral bone. Fixation for OLT has been shown to be clinically successful for the treatment of both acute and chronic lesions. Moreover, the indication for osteochondral fragment fixation is expanding as recent studies have found good clinical outcomes in relatively small-sized lesions. The present article describes the current evidence on fixation for acute and chronic OLT.

Hybrid Fixation for Large Unstable Juvenile Osteochondritis Dissecans Lesions: Midterm Results in Adolescent Patients With Completely or Partially Salvageable Progeny Fragment.

This study aimed to describe the midterm clinical and radiographic outcomes of a hybrid fixation technique (HFT) combining interfragmentary compression with screws and biological support provided by the osteochondral autograft transplantation system (OATS) for treating large unstable juvenile osteochondritis dissecans (JOCD) lesions involving the knee in patients aged ≤18 years. Thirteen patients (15 knees, 9 males) with unstable JOCD lesions in the knee underwent treatment. HFT was indicated for lesions that had a completely salvageable (N=10) or partially salvageable progeny fragment (N=5). Patients were evaluated at a minimum follow-up of 1 year. The mean age of the patients was 15.3 years (range, 11 to 18y), with 10 lesions involving the medial femoral condyle and 5 involving the lateral femoral condyle. The mean lesion area were 397.7mm2. The outcome measures included the Pedi-IKDC and Tegner activity scales. Radiographic evaluation consisted of assessing osteochondral graft integration using the MOCART score on MRI and determining the degree of osteoarthritis using the Kellgren-Lawrence system (KL). At a mean follow-up of 51 months (range, 12 to 143mo), the mean Pedi-IKDC and Tegner activity scale were 90.1±7.2 and 94.7±6.7 points, respectively. Patients with unilateral lesions resumed sports activities on average after 7.7 months (range, 6 to 12mo). All patients exhibited progeny fragment integration on MRI, with a mean MOCART score of 85±6.5 (range, 75 to 95). Radiographs indicated grade 1 KL joint space in 13 knees and grade 2 in 2 knees. At the last follow-up, 12 patients were asymptomatic, whereas 1 patient experienced occasional mild discomfort during intense physical activity. Six patients required additional surgery for hardware removal, and 1 patient underwent intra-articular loose body removal. The hybrid fixation technique showed promising outcomes in terms of fragment healing and midterm results for unstable JOCD lesions. These findings suggest that HFT can be considered a valid treatment option for large unstable lesions involving the femoral condyles of the knee in adolescents. Therapeutic study (level of evidence IV).

No difference between 5 and 6 weeks of non-weight bearing after osteochondral grafts for medial osteochondral defects of the talus with medial malleolar osteotomy.

The present study aimed to compare the clinical outcomes and safety at a 1-year follow-up after 5 or 6 weeks of non-weight bearing after a Talar OsteoPeriostic grafting from the Iliac Crest (TOPIC) for a medial osteochondral lesion of the talus (OLT). A retrospective comparative case-control analysis of prospectively followed patients who underwent a TOPIC procedure with medial malleolus osteotomy was performed. Patients were matched in two groups with either 5 or 6 weeks of non-weight bearing. Clinical outcomes were evaluated using the Numeric Rating Scale (NRS) during walking, rest, running, and stairclimbing. Additionally, the Foot and Ankle Outcome Score (FAOS) and American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score were assessed. Moreover, radiology and complications were assessed. Elevenpatients were included in the 5-week non-weight bearing group and 22 in the 6-week non-weight bearing group. No significant differences were found in any of the baseline variables. The NRS during walking in the 5-week group improved by 3.5 points and 4 points for the 6-week group (p = 0.58 at 1-year post-operatively). In addition, all other NRS scores, FAOS subscalesand the AOFAS scores improved (all n.s. at 1 year follow-up). No significant differences in radiological (osteotomy union and cyst presence in the graft) were found. Moreover, no significant differences were found in terms of complications and reoperations. No statistical significant differences were found in terms of clinical, radiologicaland safety outcomes between 5 or 6 weeks of non-weight bearing following a TOPIC for a medial OLT. Level III, Therapeutic.

Patient-Specific Distal Femoral Guides Optimize Cartilage Topography Matching in Osteochondral Allograft Transplantations

Background: Osteochondral allograft (OCA) transplantation is an important surgical technique for full-thickness chondral defects in the knee. For patients undergoing this procedure, topography matching between the donor and recipient sites is essential to limit premature wear of the OCA. Currently, there is no standardized process of donor and recipient graft matching. Purpose: To evaluate a novel topography matching technique for distal femoral condyle OCA transplantation using 3-dimensional (3D) laser scanning to create 3D-printed patient-specific instrumentation in a human cadaveric model. Study Design: Descriptive laboratory study. Methods: Human cadaveric distal femoral condyles (n = 12) underwent 3D laser scanning. An 18-mm circular osteochondral recipient defect was virtually created on the medial femoral condyle (MFC), and the position and orientation of the best topography-matched osteochondral graft from a paired donor lateral femoral condyle (LFC) were determined using an in silico analysis algorithm minimizing articular step-off distances between the edges of the graft and recipient defect. Distances between the entire surface of the OCA graft and the underneath surface of the MFC were evaluated as surface mismatch. Donor (LFC) and recipient (MFC) 3D-printed patient-specific guides were created based on 3D reconstructions of the scanned condyles. Through use of the guides, OCAs were harvested from the LFC and transplanted to the reamed recipient defect site (MFC). The post-OCA recipient condyles were laser scanned. The 360° articular step-off and cartilage topography mismatch were measured. Results: The mean cartilage step-off and graft surface mismatch for the in silico OCA transplant were 0.073 ± 0.029 mm (range, 0.005-0.113 mm) and 0.166 ± 0.039 mm (range, 0.120-0.243 mm), respectively. Comparatively, the cadaveric specimens postimplant had significantly larger step-off differences (0.173 ± 0.085 mm; range, 0.082-0.399 mm; P = .001) but equivalent graft surface topography matching (0.181 ± 0.080 mm; range, 0.087-0.396 mm; P = .678). All 12 OCA transplants had mean circumferential step-off differences less than a clinically significant cutoff of 0.5 mm. Conclusion: These findings suggest that the use of 3D-printed patient-specific guides for OCA transplantation has the ability to reliably optimize cartilage topography matching for LFC to MFC transplantation. This study demonstrated substantially lower step-off values compared with previous orthopaedic literature when also evaluating LFC to MFC transplantation. Using this novel technique in a model performing MFC to MFC transplantation has the potential to yield further enhanced results due to improved radii of curvature matching. Clinical Relevance: Topography-matched graft implantation for focal chondral defects of the knee in patients improves surface matching and has the potential to improve long-term outcomes. Efficient selection of the allograft also allows improved availability of the limited allograft sources.

Bone-cartilage transfer for osteochondritis dissecans of the humeral capitellum

Treatment of focal cartilage defects of the humeral capitellum with autologous bone-cartilage cylinders to prevent development of arthritis of the elbow joint. High-grade, unstable lesions (> 50% of the capitellum, gradeIII-IV according to Dipaola), including those involving the lateral edge of the capitellum and with adepth of up to 15 mm. Stable lesions and generalized osteochondritis of the capitellum (including Panner's disease), as well as arelative contraindication for lesions > 10 mm, as the largest punch has amaximum diameter of 10 mm. Arthroscopy of the elbow joint, transition to open surgery. First, the size of the cartilage defect in the capitellum is determined. Then, one (or several) osteochondral cylinders (OATS Arthex) are removed, which as far as possible completely encompass the defect zone. Corresponding intact bone-cartilage cylinders are obtained from the ipsilateral proximal lateral femoral condyle, each with a0.3 mm larger diameter via an additive miniarthrotomy. The "healthy" cylinders are then inserted into the defect zone in a"press fit" technique. An upper arm cast in neutral position of the hand for 10-14days, simultaneously beginning physiotherapy (active-assisted movements) and lymphatic drainage. As soon as painless range of motion (ROM) is restored (goal: by week6), isometric training can be started. Resistance training starts from week12. Competitive sports are only recommended after 6(-8) months. The current state of research on the surgical treatment of OCD of the humeral capitellum using autologous osteochondral grafts shows mostly promising results. Arecent meta-analysis of 24studies reports asignificantly higher (p < 0.01) rate of return to sports (94%) compared to fragment fixation (64%) or microfracture and debridement (71%) [41]. However, the increased donor-site morbidity must be taken into account (ca. 7.8%).

Paper 49: Osteochondral Allograft Transplantation for Capitellar Osteochondritis Dissecans: Excellent Patient Reported Outcomes Scores and High Return to Sports

Objectives: Unstable osteochondritis dissecans of the capitellum (OCD-C) is treated surgically, most commonly with loose body removal and marrow stimulation. This treatment has historically been associated with suboptimal return to high-demand upper extremity sports (baseball and gymnastics) and persistent elbow pain. Fresh osteochondral allograft transplantation (OAlloT) is an alternative treatment which restores subchondral bone and articular cartilage without donor site morbidity associated with autograft harvest. The purpose of this study was to evaluate the outcomes of osteochondral allograft transplantation in pediatric patients with unstable OCD-C 10mm or greater in size. Methods: A single-center prospective study was performed of consecutive pediatric patients, less than 19 years of age, with unstable OCD-C 10mm or greater in size treated with primary fresh OCAlloT using pre-cut 10mm, 12mm, or 16mm cores. Imaging, including radiographs and MRI were obtained preoperatively to assess OCD size and characteristics, as well as postoperatively to assess incorporation of the OCA. Patient reported outcome scores (PROs), including sport data, were obtained preoperatively and annually following surgery. Minimum follow-up duration was 2 years. Results: 26 elbows in 24 patients, mean age 13.4 years (11.3 – 17.1 years) met inclusion. The most common primary sport was gymnastics in 11 elbows (42%), baseball/softball in 7 elbows (27%), and cheer in 3 elbow (12%). The majority of patients (88%) played at a competitive level. Median symptom duration prior to presentation was 3 months. The most common presenting symptoms were pain (85%) and mechanical symptoms (81%). Sixteen elbows (62%) presented with a &gt;5° loss of elbow extension compared to the contralateral side. The capitellar physis was open in 23 elbows (88%). OCD location was central in 17 elbows (65%) and far lateral in 9 elbow (35%). Mean MRI size of the OCD was 11 mm in coronal width, 12 mm in sagittal length, and 6 mm in depth. Twelve elbows (48%) had a loose body on MRI. The majority of elbows (22, 85%) were treated with a single allograft plug, while 4 elbows had two allograft plugs transplanted. Median OCA size was 12 mm. There were no infections nor arthrofibrosis. Two elbows (8%) had a secondary surgery, both underwent partial synovectomy and chondroplasty at 14- and 16-months following the primary surgery. Postoperative MRIs were obtained in 15 elbows (58%) and had a mean BOGIE (Boston Osteochondral Graft Incorporation in the Elbow) score of 11, thus documenting a high degree of incorporation. Mean follow-up duration was 40 months (range 25 – 60 months). All patients had preoperative, 1-year, and 2-year PROs (Table 1). 21 elbows (81%) had returned to sports at 1-year postoperatively9, and all but 1 patient had returned to sports by 2 years following surgery. Forty-five percent of gymnasts returned to gymnastics, while the remaining pursued different sports. Five of 6 baseball players (83%) returned to baseball. Conclusions: OCAlloT as a treatment for OCD-C is a procedure associated with low rates of complications, excellent graft incorporation, high elbow function and patient satisfaction, and overall high rates of return to sports at 2-years. Return to sports, particularly among gymnasts was less than 50% in this series, which we attribute to a combination of factors, including loss of training and competition time at a critical time for an elite gymnast as well as physician counseling on alternative sports with less stress on the elbow. Continued patient follow-up is ongoing and will be critical to the assessment of this treatment on the mid- and long-term outcomes in these young athletes. [Figure: see text]

No Differences in 2-Year Reoperation Rates for Meniscus Allograft Transplant With Concomitant Cartilage Restoration or Osteotomy: A National Database Study

PurposeTo investigate reoperation rates after meniscus allograft transplant (MAT), comparing rates with and without concomitant articular cartilage and osteotomy procedures using a national insurance claims database. MethodsWe performed a retrospective cohort study of patients who underwent MAT from 2010 to 2021 with minimum 2 year follow-up using the PearlDiver database. Using Current Procedural Terminology (CPT) and International Classification of Diseases (ICD) codes, we identified patients who underwent concomitant procedures including chondroplasty or microfracture, cartilage restoration defined as osteochondral graft or autologous chondrocyte implantation (ACI), or osteotomy. Univariate logistic regressions identified risk factors for reoperation. Reoperations were classified as knee arthroplasty, interventional procedures, or diagnostic or debridement procedures. Results750 patients were included with an average age of 29.6 years (interquartile range 21.0-36.8) and average follow-up time was 5.41 years (SD: 2.51). 90-day, 2-year, and all-time reoperation rates were 1.33%, 14.4%, and 27.6% respectively. MAT with cartilage restoration was associated with increased reoperation rate at 90 days (OR: 4.88; 95% CI: 1.38-19.27; p=.015), however there was no significant difference in reoperation rates at 2 years or to the end of follow-up. ACI had increased reoperation rates at 90 days (OR: 6.95; 95% CI: 1.45-25.96; p=.006), with no difference in reoperation rates 2 years post-operatively or to the end of follow-up. Osteochondral autograft and allograft were not associated with increased reoperation rates. Conclusion14.4% of patients in our cohort had a reoperation within 2 years of MAT. Nearly one in four patients undergoing MAT had concomitant cartilage restoration, showing that it is commonly performed on patients with articular cartilage damage. Concomitant osteochondral autograft, osteochondral allograft, chondroplasty, microfracture and osteotomy were not associated with any significant difference in reoperation rates. ACI was associated with increased reoperation rates at 90 days, but not later.

Treatment of Shoulder Cartilage Defects in Athletes.

Articular cartilage defects in the glenohumeral joint may be found in laborers, the elderly, and young athletes, among others. Various factors can contribute to cartilage damage, including prior surgery, trauma, avascular necrosis, inflammatory arthritis, joint instability, and osteoarthritis. There is a wide variety of treatment options, from conservative treatment, injections, and surgical options, including arthroscopic debridement, microfracture, osteochondral autograft transfer, osteochondral graft transplantation, autologous chondrocyte implantation, and the newly emerging techniques such as biologic augmentation. There is a challenge to determine the optimal treatment options, especially for young athletes, due to limited outcomes in the literature. However, there are many options which are viable to address osteochondral defects of the glenohumeral joint.

Indications, Stability, and Surgical Outcomes of Using Osteochondral Nasal Septal Graft as a Septal Extension Graft in Rhinoplasty Patients: A Prospective Cohort Study.

Septal extension graft (SEG) is an adaptable tool that controls, supports, and stabilizes the nasal tip projection, rotation, length, and shape. Recent studies comparing SEGs to more conventional columellar strut grafts found that SEGs provided improved results. This prospective cohort study included 66 patients divided into 2 groups based on their indications. Group 1 was patients who underwent septorhinoplasty using osteochondral septal extension graft (OSEG), and group 2 underwent septorhinoplasty using cartilaginous SEG. The main reason for undergoing OSEG was insufficient septal cartilage (P<0.001). The outcomes were not significantly different between both groups, with the % of patients who experienced positive outcomes ranging from 78.8% to 97%. The OSEG is a safe, valid, and effective option in septorhinoplasty that can be used in patients with insufficient cartilaginous septum.

Enhanced hyaline cartilage formation and continuous osteochondral regeneration via 3D-Printed heterogeneous hydrogel with multi-crosslinking inks

The unique gradient structure and complex composition of osteochondral tissue pose significant challenges in defect regeneration. Restoration of tissue heterogeneity while maintaining hyaline cartilage components has been a difficulty of an osteochondral tissue graft. A novel class of multi-crosslinked polysaccharide-based three-dimensional (3D) printing inks, including decellularized natural cartilage (dNC) and nano-hydroxyapatite, was designed to create a gradient scaffold with a robust interface-binding force. Herein, we report combining a dual-nozzle cross-printing technology and a gradient crosslinking method to create the scaffolds, demonstrating stable mechanical properties and heterogeneous bilayer structures. Biofunctional assessments revealed the remarkable regenerative effects of the scaffold, manifesting three orders of magnitude of mRNA upregulation during chondrogenesis and the formation of pure hyaline cartilage. Transcriptomics of the regeneration site in vivo and scaffold cell interaction tests in vitro showed that printed porous multilayer scaffolds could form the correct tissue structure for cell migration. More importantly, polysaccharides with dNC provided a hydrophilic microenvironment. The microenvironment is crucial in osteochondral regeneration because it could guide the regenerated cartilage to ensure the hyaline phenotype.

Functional outcome after arthroscopic mosaicplasty for localized osteochondral defects in the knee

Background: Articular cartilage is complex tissue that is able to withstand tremendous amount of force over many cycle but does not have the ability to heal even after minor injury. Treatment recommendation for articular cartilage injury and arthritis includes non-operative and operative management. Mosaicplasty is a reconstructive osteochondral grafting procedure for the treatment of articular defects of the knee. Mosaicplasty entails transplantation of small cylindrical osteochondral grafts from the non-weight bearing area of the femoral condyles and transplanting them in a mosaic like fashion into a prepared defect site on the weight-bearing surfaces of the same knee. Methods: The present study was carried out in 30 patients in our hospital prospectively to determine the functional outcome results after arthroscopic mosaicplasty for localized osteochondral defects in the knee. We conducted a prospective study on 30 patients of osteochondral defect of knee. Patients were presented with pain and recurrent swelling in the knee after sustaining twisting injury in the knee. Diagnostic arthroscopy was done and the osteochondral defects is localized and treated with mosaicplasty. The graft is harvested arthoscopically from the non-weight bearing part of the femoral condyles using a harvester. Follow up of these patients is done according to Tenger Lysholm knee scoring scale at 03 months, 06 months after surgery. Results: In our study 93.33% patients showed good to excellent results and 7% patients had fair and poor results. Conclusions: Advantage of arthroscopic mosaicplasty includes implantation of hyaline cartilage without the need for any suture or adhesive, need for smaller incision minimally invasive and very less complications. Associated injuries like ACL/PCL or meniscal tear can be addressed in the same procedure. To conclude arthroscopic mosaicplasty is excellent procedure to address the focal articular cartilage injuries of knee.

Effect of Press-Fit Size on Insertion Mechanics and Cartilage Viability in Human and Ovine Osteochondral Grafts.

The osteochondral allograft procedure uses grafts constructed larger than the recipient site to stabilize the graft, in what is known as the press-fit technique. This research aims to characterize the relationships between press-fit size, insertion forces, and cell viability in ovine and human osteochondral tissue. Human (4 donors) and ovine (5 animals) articular joints were used to harvest osteochondral grafts (4.55 mm diameter, N = 33 Human, N = 35 Ovine) and create recipient sites with grafts constructed to achieve varying degrees of press fit (0.025-0.240 mm). Donor grafts were inserted into recipient sites while insertion forces were measured followed by quantification of chondrocyte viability and histological staining to evaluate the extracellular matrix. Both human and ovine tissues exhibited similar mechanical and cellular responses to changes in press-fit. Insertion forces (Human: 3-169 MPa, Ovine: 36-314 MPa) and cell viability (Human: 16%-89% live, Ovine: 2%-76% live) were correlated to press-fit size for both human (force: r = 0.539, viability: r = -0.729) and ovine (force: r = 0.655, viability: r = -0.714) tissues. In both species, a press-fit above 0.14 mm resulted in reduced cell viability below a level acceptable for transplantation, increased insertion forces, and reduced linear correlation to press-fit size compared to samples with a press-fit below 0.14 mm. Increasing press-fit size required increased insertion forces and resulted in reduced cell viability. Ovine and human osteochondral tissues responded similarly to impact insertion and varying press-fit size, providing evidence for the use of the ovine model in allograft-related research.

Free hemi-hamate arthroplasty: A review of donor site outcomes

IntroductionThe use of the dorsal hamate as a free osteochondral bone graft or vascularized bone flap has become the mainstay for large, comminuted middle phalanx volar lip fractures. To date, few studies have been conducted in the assessment of donor site morbidity for the hemi-hamate graft or flap, and none have discussed modes of repair or reconstruction of this donor site. MethodsA retrospective analysis of 14 hemi-hamate arthroplasty (HHA) procedures, including 6 vascularized and 8 non-vascularized grafts, from two surgeons was performed. Four hamate defect reconstruction techniques were utilized: no formal reconstruction, autologous bone grafting, gel foam, or synthetic bone substitute. The dorsal capsule was repaired with either extensor retinaculum grafting or by direct closure. Wrist range of motion, pain scores, and radiographic alignment were assessed. ResultsAt 6 months follow-up, all patients achieved full, pain-free wrist motion compared to the uninjured side, with visual analog scale pain scores of 0. Serial radiographs showed maintained carpal alignment without instability or subluxation. No differences based on the hamate defect reconstruction method or capsular repair technique was demonstrated. ConclusionSafe return to pain free, unrestricted wrist function is achievable after HHA, regardless of hamate donor site management. Adequate dorsal capsular repair appears critical to prevent instability. Further study is needed to compare techniques, but choice may be guided by surgeon preference in the absence of clear evidence.

A Finite Element Model to Investigate the Stability of Osteochondral Grafts Within a Human Tibiofemoral Joint

Osteochondral grafting has demonstrated positive outcomes for treating articular cartilage defects by replacing the damaged region with a cylindrical graft consisting of bone with a layer of cartilage. However, factors that cause graft subsidence are not well understood. The aim of this study was to develop finite element (FE) models of osteochondral grafts within a tibiofemoral joint, suitable for an investigation of parameters affecting graft stability. Cadaveric femurs were used to experimentally calibrate the bone properties and graft-bone frictional forces for use in corresponding image-based FE models, generated from µCT scan data. Effects of cartilage defects and osteochondral graft repair were measured by examining contact pressure changes using further in vitro tests. Here, six defects were created in the femoral condyles, which were subsequently treated with osteochondral autografts or metal pins. Matching image-based FE models were created, and the contact patches were compared. The bone material properties and graft-bone frictional forces were successfully calibrated from the initial tests with good resulting levels of agreement (CCC = 0.87). The tibiofemoral joint experiment provided a range of cases that were accurately described in the resultant pressure maps and were well represented in the FE models. Cartilage defects and repair quality were experimentally measurable with good agreement in the FE model pressure maps. Model confidence was built through extensive validation and sensitivity testing. It was found that specimen-specific properties were required to accurately represent graft behaviour. The final models produced are suitable for a range of parametric testing to investigate immediate graft stability.

Autologous Costal Chondral/Osteochondral Transplantation and Costa-Derived Chondrocyte Implantation for Articular Cartilage Repair: Basic Science and Clinical Applications.

There has been increasing application of autologous costal chondral/osteochondral transplantation (ACCT/ACOT) and costa-derived chondrocyte implantation (ACCI) for articular cartilage repair over the past three decades. This review presents the major evidence on the properties of costal cartilage and bone and their qualifications as grafts for articular cartilage repair, the major clinical applications, and the risks and strategies for costal chondral/osteochondral graft(s) harvest. First, costal cartilage has many specific properties that help restore the articular surface. Costa, which can provide abundant cartilage and cylindrical corticocancellous bone, preserves permanent chondrocyte and is the largest source of hyaline cartilage. Second, in the past three decades, autologous costal cartilage-derived grafts, including cartilage, osteochondral graft(s), and chondrocyte, have expanded their indications in trauma and orthopaedic therapy from small to large joints, from the upper to lower limbs, and from non-weight-bearing to weight-bearing joints. Third, the rate of donor-site complications of ACCT or ACOT is low, acceptable, and controllable, and some skills and accumulated experience can help reduce the risks of ACCT and ACOT. Costal cartilage-derived autografting is a promising technique and could be an ideal option for articular chondral lesions with or without subchondral cysts. More high-quality clinical studies are urgently needed to help us further understand the clinical value of such technologies.

Outcomes of Osteochondral Autologous Transplantation with Ipsilateral Lateral Talar Autograft for Medial Osteochondral Lesions of the Talus.

Osteochondral autologous transplantation (OAT) has been widely used in the treatment of osteochondral lesion of the talus (OLT). Previous studies have reported successful outcomes following the use of osteochondral autogenous grafts from the intercondylar notch of the knee or a non-weight-bearing region of the femoral condyle. However, donor-site morbidity of the knee joint has been observed in several cases. This study aimed to investigate the outcomes and safety of OAT with autografts from the ipsilateral lateral talar articular facet as an alternative donor site for medial OLT. Among 40 patients who underwent OAT, 29 patients were excluded. Eleven patients who underwent OAT with an osteochondral graft harvested from the ipsilateral lateral talar articular facet from 2011 to 2022 were retrospectively analyzed. The size of OLT was measured on ankle magnetic resonance imaging, including coronal length, sagittal length, depth, and area. Clinical outcomes were evaluated using the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale and a visual analog scale (VAS). Weight-bearing ankle radiographs were obtained postoperatively and at 1 year after surgery. The average follow-up time after surgery was 64.7 months (range, 14-137 months). The average diameter of lesions was 8.8 mm (range, 8-9.9 mm). The average size of lesions was 51.2 mm2 (range, 33.6-71.3 mm2) , and all lesions included subchondral cysts. The average depth of lesions was 7.3 mm (range, 6.2-9.1 mm). Graft sizes ranged from 8 to 10 mm in diameter (8 mm, n = 1; 10 mm, n = 10) All measured clinical outcomes improved postoperatively, including the AOFAS scores (preoperative, 55.4 ± 9.0; 1-year follow-up, 92.1 ± 7.6; p = 0.001) and VAS scores (preoperative, 5.5 ± 0.7; 1-year follow-up, 1.9 ± 0.8; p = 0.001). All weight-bearing ankle radiographs of the graft and donor sites did not reveal arthritic change in the ankle joint, lateral talar dome collapse, and graft-site delayed union or nonunion at 1 year after surgery. For a single medial OLT, harvesting autografts from the ipsilateral lateral talar articular facet without knee donor-site morbidities can be a good alternative in OAT for OLT.

Functional performance of a bi-layered chitosan-nano-hydroxyapatite osteochondral scaffold: a pre-clinical in vitro tribological study.

Osteochondral grafts are used for repair of focal osteochondral lesions. Autologous grafts are the gold standard treatment; however, limited graft availability and donor site morbidity restrict use. Therefore, there is a clinical need for different graft sources/materials which replicate natural cartilage function. Chitosan has been proposed for this application. The aim of this study was to assess the biomechanics and biotribology of a bioresorbable chitosan/chitosan-nano-hydroxyapatite osteochondral construct (OCC), implanted in an in vitro porcine knee experimental simulation model. The OCC implanted in different surgical positions (flush, proud and inverted) was compared to predicate grafts in current clinical use and a positive control consisting of a stainless steel graft implanted proud of the cartilage surface. After 3 h (10 800 cycles) wear simulation under a walking gait, subsidence occurred in all OCC samples irrespective of surgical positioning, but with no apparent loss of material and low meniscus wear. Half the predicate grafts exhibited delamination and scratching of the cartilage surfaces. No graft subsidence occurred in the positive controls but wear and deformation of the meniscus were apparent. Implanting a new chitosan-based OCC either optimally (flush), inverted or proud of the cartilage surface resulted in minimal wear, damage and deformation of the meniscus.

Treatment of osteochondritis dissecans

Osteochondritis dissecans (OD) is arare condition with an incidence of 30/100,000. It especially affects male patients aged 10-20years old. During the staged progression the osteochondral fragments can detach from their base. These can damage the adjacent articular cartilage, which can lead to premature osteoarthritis. Most commonly affected are the knee, ankle and elbow joints. The exact pathogenesis of OD has so far not been clearly confirmed. Several risk factors that can lead to the development of OD are discussed. These include repeated microtrauma and vascularization disorders that can lead to ischemia of the subchondral bone and to aseparation of the fragments close to the joint and therefore to the development of free joint bodies. For an adequate clarification patients should undergo athorough radiological evaluation including X‑ray imaging followed by magnetic resonance imaging (MRI) to assess the integrity of the cartilage-bone formation with determination of the OD stage. The assessment is based on criteria of the International Cartilage Repair Society (ICRS). The instability of the cartilage-bone fragment increases with higher stages. StagesI andII with stable cartilage-bone interconnection can be treated conservatively. For stagesIII andIV, i.e., instability of the OD fragment or the presence of free fragments, surgical treatment should be performed. Primarily, refixation of afree joint body should be carried out depending on the size and vitality of the fragment. In cases of unsuccessful conservative treatment or fixation, adebridement, if necessary in combination with a bone marrow stimulating procedure, can be employed corresponding to the size of the defect. For larger cartilage defects, an osteochondral graft transplantation should be considered. Overall, OD lesions in stagesI andII show agood healing tendency under conservative treatment. In cases of incipient unstable OD, refixation can also lead to good clinical and radiological results.

Osteochondral tissue engineering in translational practice: histological assessments and scoring systems.

Osteochondral lesions are common pathological alterations in synovial joints. Different techniques have been designed to achieve osteochondral repair, and tissue-engineered osteochondral grafts have shown the most promise. Histological assessments and related scoring systems are crucial for evaluating the quality of regenerated tissue, and the interpretation and comparison of various repair techniques require the establishment of a reliable and widely accepted histological method. To date, there is still no consensus on the type of histological assessment and scoring system that should be used for osteochondral repair. In this review, we summarize common osteochondral staining methods, discuss the criteria regarding high-quality histological images, and assess the current histological scoring systems for osteochondral regeneration. Safranin O/Fast green is the most widely used staining method for the cartilage layer, whereas Gomori and Van Gieson staining detect new bone formation. We suggest including the graft-host interface and more sections together with the basic histological information for images. An ideal scoring system should analyze both the cartilage and bone regions, especially for the subchondral bone plate. Furthermore, histological assessments should be performed over a longer period of time to minimize discrepancies caused by defect size and animal species.