Articular cartilage is often damaged, and its treatment is usually performed by surgical operation. Today, tissue engineering offers an alternative treatment option for injuries or diseases with increasing importance. Infrapatellar fat pad (IPFP) is a densely vascularized and innervated extra synovial tissue that fills the anterior knee compartment. Adipose-derived stem cells from infrapatellar fat pad (IPFP-ASCs) have multipotency means that they can differentiate into connective tissue cells and have age-independent differentiation capacity as compared to other stem cells. In this study, the osteochondral tissue construct was designed with different inner pattern due to original osteochondral tissue structure and fabrication of it was carried out by 3D printing. For this purpose, alginate (3% w/v) and carboxymethylcellulose (CMC) (9%w /v) were used as bioink. Also, IPFP-ASCs were isolated with enzymatic degradation. Osteogenic and chondrogenic differentiation of IPFP-ASCs were investigated with Alizarin Red and Alcian Blue staining, respectively. IPFP-ASCs-laden osteochondral graft differentiation will be induced by controlled release of growth factor BMP-2 and TGF-β. Before this step, nanocapsules formation with double emission technique with model protein BSA was carried out with different concentration of PCL (5%,10% and 20%). The morphology and structure of the nanocapsules were determined with scanning electron microscopy (SEM). Also, we successfully designed and printed alginate and CMC based scaffold with 20 layers. Chondrogenic and osteogenic differentiation of IPFP-ASCs with suitable culture conditions was obtained. The isolation of IPFP-ASCs, formation of the nanocapsules, and 3D printing of osteochondral graft were carried out successfully

Autologous osteochondral transplantation (AOT) is an effective treatment for large Osteochondral Lesions of the Talus (OLT), however little is reported on an athletic population, who are likely to place higher demands on the reconstruction. The aim is to report the outcomes of large OLT (>150mm. 2. ) within an athletic population. The study population was limited to professional or amateur athletes (Tegner score >6) with an OLT of size 150mm. 2. or greater. The surgical intervention was AOT with a donor site from the lateral femoral condyle. Clinical outcomes at a minimum of 24 months included Return to Sport, VAS and FAOS Scores. In addition, graft incorporation was evaluated by MRI using MOCART scores at 12 months post-surgery. 38 athletes including 11 professional athletes were assessed. Mean follow-up was 46 months. Mean lesion size was 249mm. 2. 33 patients returned to sport at their previous level and one did not return to sport (mean return to play 8.2 months). Visual analogue scores improved from 4.53 pre-operatively to 0.63 post-operatively (p=0.002). FAOS Scores improved significantly in all domains (p< 0.001). Two patients developed knee donor site pain, and both had three osteochondral plugs harvested. Univariant analysis demonstrated no association between pre-operative patient or lesion characteristics and ability to return to sport. However, there was a strong correlation between MOCART scores and ability to return to sport (AUC=0.89). Our study suggests that AOT is a viable option in the management of large osteochondral talar defects in an athletic population, with favourable return to sport levels, patient satisfaction, and FAOS/VAS scores. The ability to return to sport is predicated upon good graft incorporation and further research is required to optimise this technique. Our data also suggests that patients should be aware of the increased risk of developing knee donor site pain when three osteochondral plugs are harvested

Introduction. The purpose of this study was to examine trends in patient characteristics and clinical outcomes that occur with age as a statistical variable when performing autologous osteochondral transplantation (AOT) for the treatment of osteochondral lesions of the talus (OLT). Methods. A retrospective cohort study for AOT procedures on 78 patients from 2006 to 2019. was conducted Clinical outcomes were evaluated via FAOS scores. A multivariable linear regression was used to assess the independent factors predictive of the first post-operative FAOS after AOT. The independent variables included pre-operative FAOS, age, defect size, shoulder lesion, cystic lesion, prior traumatic injury, and history of microfracture surgery. A p-value <.05 was considered significant and 95% confidence limits (95% CL) for regression coefficient estimates (est.) were calculated. Results. 78 patients were included with a mean age of 35.5 ± 13.6years at a mean follow-up was 54.4 ± 18.9 months. The mean pre-operative FAOS was 54.3 ± 19.4 and the mean post-operative FAOS was 83.4 ± 13.6. The mean defect size was 109.3±62.4 mm2. The multivariable linear regression showed that the pre-operative FAOS was associated with a higher post-operative FAOS (est., 95% CL: 0.16, 0.012 – 0.307; p=0.034). Defect size (est., 95% CL: −0.05, −0.097 – −0.003; p=0.0358), having a shoulder lesion (est., 95% CL: −9.068, −15.448 – −2.688; p=0.006), or having a prior microfracture surgery (est., 95% CL: −7.07, −13.118 – −1.021; p=0.0226) were associated with a lower post-operative FAOS. Conclusion. Patient age was not an independent risk factor for inferior clinical outcomes after AOT for OLT. Additionally, cystic lesions, or lesions with a traumatic aetiology were not significantly associated with post-operative FAOS. Having a shoulder lesion had the largest marginal effect on post-operative FAOS. These findings provide important information for providers when counseling and selecting patients for AOT procedure for treatment of OLT

Aims. The present study investigates the effectiveness of platelet-rich plasma (PRP) gel without adjunct to induce cartilage regeneration in large osteochondral defects in a rabbit model. Methods. A bilateral osteochondral defect was created in the femoral trochlear groove of 14 New Zealand white rabbits. The right knees were filled with PRP gel and the contralateral knees remained untreated and served as control sides. Some animals were killed at week 3 and others at week 12 postoperatively. The joints were harvested and assessed by Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) MRI scoring system, and examined using the International Cartilage Repair Society (ICRS) macroscopic and ICRS histological scoring systems. Additionally, the collagen type II content was evaluated by the immunohistochemical staining. Results. After 12 weeks post-surgery, the defects of the PRP group were repaired by hyaline cartilage-like tissue. However, incomplete cartilage regeneration was observed in the PRP group for three weeks. The control groups showed fibrocartilaginous or fibrous tissue, respectively, at each timepoint. Conclusion. Our study proved that the use of PRP gel without any adjuncts could successfully produce a good healing response and resurface the osteochondral defect with a better quality of cartilage in a rabbit model. Cite this article: Bone Joint Res 2021;10(3):192–202

Autologous 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, taken from a non-loadbearing region of the knee. Despite positive clinical use, factors that cause graft subsidence or poor integration are relatively unknown. The aim of this study was to develop finite element (FE) models of osteochondral grafts within a tibiofemoral joint and to investigate parameters affecting osteochondral graft stability. Initial experimental tests on cadaveric femurs were performed to calibrate the bone properties and graft-bone frictional forces for use in corresponding FE models, generated from µCT scan data. The effects of cartilage defects and osteochondral graft repair were measured by examining contact pressure changes using in vitro tests on a single cadaveric human tibiofemoral joint. Six defects were created in the femoral condyles which were subsequently treated with osteochondral autografts or metal pins. Matching µCT scan-based FE models were created, and the contact patches were compared. Sensitivity to graft bone properties was investigated. 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 to model. These cases were well captured experimentally and represented accurately in the FE models. Graft properties relative to host bone had large effects on immediate graft stability despite limited changes to resultant cartilage contact pressure. Model confidence was built through extensive validation and sensitivity testing, and demonstrated that specimen-specific properties were required to accurately represent graft behaviour. The results indicate that graft bone properties affect the immediate stability, which is important for the selection of allografts and design of future synthetic grafts. Acknowledgements. Supported by the EPSRC-EP/P001076

Perilesional changes of chronic focal osteochondral defects were assessed in the knees of 23 sheep. An osteochondral defect was created in the main load-bearing region of the medial condyle of the knees in a controlled, standardised manner. The perilesional cartilage was evaluated macroscopically and biopsies were taken at the time of production of the defect (T0), during a second operation one month later (T1), and after killing animals at three (T3; n = 8), four (T4; n = 8), and seven (T7; n = 8) months. All the samples were histologically assessed by the International Cartilage Repair Society grading system and Mankin histological scores. Biopsies were taken from human patients (n = 10) with chronic articular cartilage lesions and compared with the ovine specimens. The ovine perilesional cartilage presented with macroscopic and histological signs of degeneration. At T1 the International Cartilage Repair Society ‘Subchondral Bone’ score decreased from a mean of 3.0 (. sd. 0) to a mean of 1.9 (. sd. 0.3) and the ‘Matrix’ score from a mean of 3.0 (. sd. 0) to a mean of 2.5 (. sd. 0.5). This progressed further at T3, with the International Cartilage Repair Society ‘Surface’ grading, the ‘Matrix’ grading, ‘Cell Distribution’ and ‘Cell Viability’ grading further decreasing and the Mankin score rising from a mean of 1.3 (. sd. 1.4) to a mean of 5.1 (. sd. 1.6). Human biopsies achieved Mankin grading of a mean of 4.2 (. sd. 1.6) and were comparable with the ovine histology at T1 and T3. The perilesional cartilage in the animal model became chronic at one month and its histological appearance may be considered comparable with that seen in human osteochondral defects after trauma

The treatment of osteochondral lesions of the talus has evolved with the development of improved imaging and arthroscopic techniques. However, the outcome of treatment for large cystic type-V lesions is poor, using conventional grafting, debridement or microfracture techniques. This retrospective study examined the outcomes of 50 patients with a cystic talar defect who were treated with arthroscopically harvested, cored osteochondral graft taken from the ipsilateral knee. Of the 50 patients, 45 (90%) had a mean good to excellent score of 80.3 (52 to 90) in the Karlsson-Peterson Ankle Score, at a mean follow-up of 36 months (24 to 83). A malleolar osteotomy for exposure was needed in 26 patients and there were no malleolar mal- or nonunions. One patient had symptoms at the donor site three months after surgery; these resolved after arthroscopic release of scar tissue. This technique is demanding with or without a malleolar osteotomy, but if properly performed has a high likelihood of success

INTRODUCTION. Osteochondral lesions of the knee are relatively common both in young and senior population. The very disabling clinical symptoms, in association to the scarce regenerative capacity of the articular cartilage and the increased risk of developing a secondary osteoarthritis make an effective treatment mandatory. MATERIALS AND METHODS. From December 2008 to January 2013, 34 patients (35 knees), 24 males and 10 females (mean age 36.2 years range 14–66) underwent implant of Maioregen® (Finceramica Faenza S.P.A, Italy) biomimetic osteochondral scaffold. In 17 cases the osteochondral lesion was cause by an osteochondritis dissecans (acute or sequela), in 13 cases by a spontaneous osteonecrosis and in 4 cases the etiology was traumatic. Patients were evaluated with subjective IKDC and Tegner Lysholm scores, VAS and Tegner Activity Scale before surgery and at regular follow up (mean follow up 38.4 months, range 13 months max 63 months). RESULTS. Both Lysholm and IKDC Subjective scores significantly increased from 57.5 and 48.2 before surgery to 89.7 and 76.3 at 1 year follow up. Mean VAS scale score decreased from 6.3 to 2 at 1 year follow up. At 3 years follow up 20 evaluated patients showed an increment on both scales (Lysholm 92.38, IKDC 84.7). Only 4 patients were evaluated at 5 years follow up with mean subjective IKDC 92.5, Lysholm 98.75 and VAS 1. DISCUSSION. Maioregen ® biomimetic osteochondral scaffold showed very good results as surgical treatment option in treating ICRS grade 3–4 osteochondral lesions whatever the etiology. In particular, the implant showed good results also in treatment of osteonecrosis and could provide an alternative to unicompartimental arthroplasty in young and active patients

Purpose. Osteochondral lesions of the knee are relatively common both in young and senior population. The very disabling clinical symptoms, in association to the scarce regenerative capacity of the articular cartilage and the increased risk of developing a secondary osteoarthritis make an effective treatment mandatory. Methods and Materials. From December 2008 to January 2013, 34 patients (35 knees), 24 males and 10 females (mean age 36.2 years range 14–66) underwent implant of Maioregen® (Finceramica Faenza S.P.A, Italy) biomimetic tri-layer osteochondral scaffold. In 17 cases the osteochondral lesion was cause by an osteochondritis dissecans (acute or sequela), in 13 cases by a spontaneous osteonecrosis and in 4 cases the etiology was traumatic. Patients were evaluated with subjective IKDC and Tegner Lysholm scores, VAS and Tegner Activity Scale before surgery and at regular follow up (mean follow up 38.4 months, range 13 months max 63 months). Results. Both Lysholm and IKDC Subjective scores significantly increased from 57.5 and 48.2 before surgery to 89.7 and 76.3 at 1 year follow up. Mean VAS scale score decreased from 6.3 to 2 at 1 year follow up. At 3 years follow up 20 evaluated patients showed an increment on both scales (Lysholm 92.38, IKDC 84.7). Only 4 patients were evaluated at 5 years follow up with mean subjective IKDC 92.5, Lysholm 98.75 and VAS 1. Conclusion. Maioregen® biomimetic osteochondral scaffold showed very good results as surgical treatment option in treating ICRS grade 3–4 osteochondral lesions whatever the etiology. In particular, the implant showed good results also in treatment of osteonecrosis and could provide an alternative to unicompartimental arthroplasty in young and active patients

Introduction and Objectives: Osteochondral lesions of the talus are difficult to treat due to difficult access, vascularisation, and because the head of the talus is a region with significant mechanical load. Among the therapeutic options for osteochondral lesions of the head of the talus, we present a treatment alternative using mosaicplasty with an autologous osteochondral graft taken from the knee. Materials and Methods: We have treated 8 patients affected with osteochondral lesions of the head of the talus (7 medial and 1 lateral) of greater than 7mm diameter, younger than 45 years of age, and with no instability of the ligament. The talus was approached in all cases by means of osteotomy of the malleolus. Osteocartilaginous cores were collected from the ipsilateral lateral condyle of the ipsilateral knee with minimal arthrotomy. Rehabilitation began between days 3 and 5 with no weight bearing before the 6th week. Results were measured by means of CTscan, MRI, and pathology, and clinically using the Maryland scale. Results: All patients presented with evidence of osteointegration of the osteochondral graft. All were classified as excellent or good on the Maryland scale. Functional results were good with flexion and extension movements of the ankle practically symmetrical with the healthy limb. There were no complications in the donor site or infections. None of the patients has required repeat treatment except in the cases in which material for osteosynthesis was removed from the malleolus. Discussion and Conclusions: We believe that in view of the results of mosaicplasty with an autologous osteochondral graft taken from the knee, this provides a new therapeutic approach to treatment of grade III and IV osteochondral lesions of the talus. The most significant advantages of this technique include the repair of articular cartilage with type II collagen and an earlier discharge time due to osseous integration. The most important disadvantages were potential morbidity associated with the donor site and the technical difficulty in achieving convexity

Aims. The purpose of this study was to explore a simple and effective method of preparing human acellular amniotic membrane (HAAM) scaffolds, and explore the effect of HAAM scaffolds with juvenile cartilage fragments (JCFs) on osteochondral defects. Methods. HAAM scaffolds were constructed via trypsinization from fresh human amniotic membrane (HAM). The characteristics of the HAAM scaffolds were evaluated by haematoxylin and eosin (H&E) staining, picrosirius red staining, type II collagen immunostaining, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Human amniotic mesenchymal stem cells (hAMSCs) were isolated, and stemness was verified by multilineage differentiation. Then, third-generation (P3) hAMSCs were seeded on the HAAM scaffolds, and phalloidin staining and SEM were used to detect the growth of hAMSCs on the HAAM scaffolds. Osteochondral defects (diameter: 3.5 mm; depth: 3 mm) were created in the right patellar grooves of 20 New Zealand White rabbits. The rabbits were randomly divided into four groups: the control group (n = 5), the HAAM scaffolds group (n = 5), the JCFs group (n = 5), and the HAAM + JCFs group (n = 5). Macroscopic and histological assessments of the regenerated tissue were evaluated to validate the treatment results at 12 weeks. Results. In vitro, the HAAM scaffolds had a network structure and possessed abundant collagen. The HAAM scaffolds had good cytocompatibility, and hAMSCs grew well on the HAAM scaffolds. In vivo, the macroscopic scores of the HAAM + JCFs group were significantly higher than those of the other groups. In addition, histological assessments demonstrated that large amounts of hyaline-like cartilage formed in the osteochondral defects in the HAAM + JCFs group. Integration with surrounding normal cartilage and regeneration of subchondral bone in the HAAM + JCFs group were better than those in the other groups. Conclusion. HAAM scaffolds combined with JCFs promote the regenerative repair of osteochondral defects. Cite this article: Bone Joint Res 2022;11(6):349–361

We used fresh small-fragment osteochondral allografts to reconstruct post-traumatic osteochondral defects in 126 knees of 123 patients with a mean age of 35 years. At a mean follow-up of 7.5 years (2 to 20), 108 knees were rated as successful (85%) and 18 had failed (15%). The factors related to failure included age over 50 years (p = 0.008), bipolar defects (p < 0.05), malaligned knees with overstressing of the grafts, and workers’ compensation cases (p < 0.04). Collapse of the graft by more than 3 mm and of the joint space of more than 50% were seen more frequently in radiographs of failed grafts. Our encouraging clinical results for fresh small-fragment osteochondral allografts show that they are indicated for unipolar post-traumatic osteochondral defects of the knee in young active patients

Post-traumatic osteoarthritis (PTOA) is a subset of osteoarthritis, which occurs secondary to traumatic joint injury which is known to cause pathological changes to the osteochondral unit. Articular cartilage degradation is a primary hallmark of OA, and is normally associated with end-stage disease. However, subchondral bone marrow lesions are associated with joint injury, and may represent localized bone microdamage. Changes in the osteochondral unit have been traditionally studied using explant models, of which the femoral-head model is the most common. However, the bone damage caused during harvest can confound studies of microdamage. Thus, we used a novel patellar explant model to study osteochondral tissue dynamics and mechanistic changes in bone-cartilage crosstalk. Firstly, we characterized explants by comparing patella with femoral head models. Then, the patellar explants (n=269) were subjected to either mechanical or inflammatory stimulus. For mechanical stimulus 10% strain was applied at 0.5 and 1 Hz for 10 cycles. We also studied the responses of osteochondral tissues to 10ng/ml of TNF-α or IL-1β for 24hrs. In general the findings showed that patellar explant viability compared extremely well to the femoral head explant. Following IL-1β or TNF-α treatment, MMP13, significantly increased three days post exposure, furthermore we observed a decrease in sulfate glycoaminoglycan (sGAG) content. Bone morphometric analysis showed no significant changes. Contrastingly, mechanical stimulation resulted in a significant decrease sGAG particularly at 0.5Hz, where an increase in MMP13 release 24hrs post stimulation and an upregulation of bone and cartilage matrix degradation markers was observed. Furthermore, mechanical stimulus caused increases in TNF-α, MMP-8, VEGF expression. In summary, this study demonstrates that our novel patella explant model is an excellent system for studying bone-cartilage crosstalk, which responds well to both mechanical and inflammatory stimulus and is thus of great utility in the study of PTOA

Aims. The hypothesis of this study was that bone peg fixation in the treatment of osteochondral lesions of the talus would show satisfactory clinical and radiological results, without complications. Methods. Between September 2014 and July 2017, 25 patients with symptomatic osteochondritis of the talus and an osteochondral fragment, who were treated using bone peg fixation, were analyzed retrospectively. All were available for complete follow-up at a mean 22 of months (12 to 35). There were 15 males and ten females with a mean age of 19.6 years (11 to 34). The clinical results were evaluated using a visual analogue scale (VAS) and the American Orthopaedic Foot and Ankle Society (AOFAS) score preoperatively and at the final follow-up. The radiological results were evaluated using classification described by Hepple et al based on the MRI findings, the location of the lesion, the size of the osteochondral fragment, and the postoperative healing of the lesion. Results. The mean VAS and AOFAS score improved significantly from 6.3 (4 to 8) and 70.6 (44 to 78) preoperatively to 1.6 (0 to 5) and 91.1 (77 to 100) at the final follow-up, respectively (p < 0.001). The classification on MRI was stage 2a in nine patients, stage 3 in 14, and stage 4 in two. The lesion was located on the posteromedial aspect of the dome of the talus in 19 patients, the anterolateral aspect in five, and the centrolateral aspect in one. The mean size of the fragment was 11.2 mm (5 to 20) horizontally, 10.4 mm (7 to 18) vertically, and 5.2 mm (3 to 10) deep, respectively. The postoperative healing state was good in 19 patients and fair in six. Conclusion. Bone peg fixation for osteochondral lesions of the talus showed satisfactory clinical and radiographic results, without complications. This technique could be a good form of treatment for patients with this condition who have an osteochondral fragment. Cite this article: Bone Joint J 2020;102-B(10):1349–1353

Introduction Twelve patients with an osteochondral lesion of the talus were treated with excision of the lesions and local osteochondral autogenous grafting. Methods The lesion was accessed through a replaceable bone block removed from the anterior tibial plafond. The graft was harvested from the medial or lateral talar articular facet on the same side of the lesion. The average age of the patients was 41 years and duration of symptoms was 90 months (average). There were six males and six females with the right talus involved in eight and the left in four patients. Graft sizes ranged from four to eight millimetres in diameter. Results There was a significant improvement in the AOFAS score from 64.4 (average) pre-operatively to 90.8 (average post-operatively (p< 0.0001) at follow-up of 25.3 months (average). The AOFAS score was slightly higher in patients under 40 years of age and in those without pre-existing joint arthritis. All patients were very satisfied with the procedure. Arthroscopy performed in two patients at six and 12 months following surgery showed good graft incorporation. No complications occurred at the donor site or the site of the bone block removal on the distal tibia. Conclusions The results showed that stage III and stage IV talar osteochondral lesions can be accessed successfully excising a tibial bone block and using local autogenous osteochondral graft harvested from the ipsilateral talar articular facet. In relation to the conduct of this study, one or more of the authors has received, or is likely to receive direct material benefits

Abstract. Background. Osteochondral allograft (OCA) transplantation is a clinically and cost-effective option for symptomatic cartilage defects. In 2017 we initiated a program for OCA transplantation for complex chondral and osteochondral defects as a UK tertiary referral centre. Aim. To characterise the complications, re-operation rate, graft survivorship and clinical outcomes of knee OCA transplantation. Methodology. Analysis of a prospectively maintained database of patients treated with primary OCA transplantation from 2017 to 2021 with a minimum of one-year follow-up. Patient reported outcome measures (PROMs), complications, re-operations and failures were evaluated. Results. 37 patients with 37 knee OCA procedures were included (mean age 31.6 years [16–49 years]). Mean BMI 26.6 kg/m2 (19.1–35.9 kg/m2). The mean chondral defect size was 3cm2 (1.2–7.3 cm2). Mean duration of follow-up was 3.1 years (1–5.3 years). 16 patients underwent meniscal allograft transplantation (MAT), 6 underwent osteotomy and 4 underwent ligament reconstruction as concurrent procedures. Significant improvements in mean PROMs were noted at 12 months. 16 patients had reoperations of which 5 had more than one surgery. Of these patients 6 were related to OCA (mainly debridement and revision OCA in one patient), and the remainder were related to additional procedures including removal of plate in 2 patients. The overall failure rate was 1 in 37 patients (3%). Conclusions. Early experience of OCA as a treatment option for complex chondral and osteochondral lesions in the knee shows satisfactory results. The reoperation rate is high but at mean follow-up of 3.1 years the survival rate was 97%

Aims. To systematically review the predominant complication rates and changes to patient-reported outcome measures (PROMs) following osteochondral allograft (OCA) transplantation for shoulder instability. Methods. This systematic review, following PRISMA guidelines and registered in PROSPERO, involved a comprehensive literature search using PubMed, Embase, Web of Science, and Scopus. Key search terms included “allograft”, “shoulder”, “humerus”, and “glenoid”. The review encompassed 37 studies with 456 patients, focusing on primary outcomes like failure rates and secondary outcomes such as PROMs and functional test results. Results. A meta-analysis of primary outcomes across 17 studies revealed a dislocation rate of 5.1% and an increase in reoperation rates from 9.3% to 13.7% post-publication bias adjustment. There was also a noted rise in conversion to total shoulder arthroplasty and incidence of osteoarthritis/osteonecrosis over longer follow-up periods. Patient-reported outcomes and functional tests generally showed improvement, albeit with notable variability across studies. A concerning observation was the consistent presence of allograft resorption, with rates ranging from 33% to 80%. Comparative studies highlighted similar efficacy between distal tibial allografts and Latarjet procedures in most respects, with some differences in specific tests. Conclusion. OCA transplantation presents a promising treatment option for shoulder instability, effectively addressing both glenoid and humeral head defects with favourable patient-reported outcomes. These findings advocate for the inclusion of OCA transplantation in treatment protocols for shoulder instability, while also emphasizing the need for further high-quality, long-term research to better understand the procedure’s efficacy profile. Cite this article: Bone Jt Open 2024;5(7):570–580

Osteochondral autologous transplantation (OATS) is a new technique for the treatment of osteochondral defects. In a prospective randomised study, between November 1996 and June 2000 we used the OATS technique to treat 136 patients (90 male, 46 female) with a mean osteochondral defect of 3.3 cm2. The defect was in the medial femoral condyle in 54 cases, the lateral femoral condyle in nine, the patella in 15, the trochlea in six, the tibial plateau in one, the talus in 29, the tibial plafond in two, the capitellum in four. There were 16 other locations. The procedure was performed either open or arthroscopically. A mean of 2.2 cylinders was transplanted. At the same time, we treated malalignment by high tibial osteotomy (HTO) in 20 patients, and instability by anterior (ACL) or posterior cruciate ligament (PCL) reconstruction in 16. Five patients required reconstruction of both ACL and PCL. The Lysholm score in the lower limbs increased from a preoperative mean of 58.3 (20 to 77) to a mean of 90.2 (70 to 100). Treatment by OATS alone increased the score from 62.9 to 91.6. The combination of OATS and HTO increased the score from 65.2 to 91.6. With additional ACL/PCL reconstruction, the score increased from 49.9 to 82.6. The combination of OATS, HTO and ACL/PCL reconstruction increased the Lysholm score from 55.5 to 85.5. Control postoperative MRI with IV contrast (Gd-DTPA) showed incorporation of all but one cylinder. Complications included one case of arthrofibrosis and sinking of one cylinder. One patient developed regional pain syndrome and three had pain at the malleolar osteotomy site, resolved by screw removal. For four weeks after the operation, 10% of patients complained of pain at the donor side in the lateral femoral condyle. There were no complications related to OATS performed in the upper limbs, and control MRI three months postoperatively showed incorporation of all cylinders. The results are encouraging, and give rise to the hope that this cost-effective and safe new treatment for limited osteochondral defects may delay or even prevent the onset of osteoarthritis

Twelve patients with an osteochondral lesion of the talus were treated with local osteochondral autogenous grafting. The graft was harvested locally from the medial or lateral talar articular facet. The procedure was combined with an osteotomy of the anterior tibial plafond modifying the technique of Flick and Gould. The average age of the patients was 41 years (range 19 to 68) with an average duration of symptoms of 90 months (range 3 – 240 months). There were six males and six females with the right talus involved in eight and the left in four patients. Results showed an improvement in the AOFAS score from an average of 69 pre-operatively to 90.2 post-operatively, at an average follow up of 15 months (range 6 to 31 months). The results tended to improve with time and was higher for patients under 40 years of age and in those without pre-existing joint arthritis. All patients were very satisfied with the procedure. Arthroscopy performed in two patients at six and 12 months following surgery showed good graft incorporation. No complications were seen from the donor site or from the osteotomy site on the distal tibia. Our results show that stage III and IV talar lesions can be treated successfully using local autogenous osteochondral graft from the medial or lateral talar articular facet

Osteochondral glenoid loss is associated with recurrent shoulder instability. The critical threshold for surgical stabilization is multidimensional and conclusively unknown. The aim of this work was to provide a well- measurable surrogate parameter of an unstable shoulder joint for the frequent anterior-inferior dislocation direction. The shoulder stability ratio (SSR) of 10 paired human cadaveric glenoids was determined in anterior-inferior dislocation direction. Osteochondral defects were simulated by gradually removing osteochondral structures in 5%-stages up to 20% of the intact diameter. The glenoid morphological parameters glenoid depth, concavity gradient, and defect radius were measured at each stage by means of optical motion tracking. Based on these parameters, the osteochondral stability ratio (OSSR) was calculated. Correlation analyses between SSR and all morphological parameters, as well as OSSR were performed. The loss of SSR, concavity gradient, depth and OSSR with increasing defect size was significant (all p<0.001). The loss of SSR strongly correlated with the losses of concavity gradient (PCC = 0.918), of depth (PCC = 0.899), and of OSSR (PCC = 0.949). In contrast, the percentage loss based on intact diameter (defect size) correlated weaker with SSR (PCC=0.687). Small osteochondral defects (≤10%) led to significantly higher SSR decrease in small glenoids (diameter <25mm) compared to large (≥ 25mm) ones (p ≤ 0.009). From a biomechanical perspective, the losses of concavity gradient, glenoid depth and OSSR correlate strong with the loss of SSR. Therefore, especially the loss of glenoidal depth may be considered as a valid and reliable alternative parameter to describe shoulder instability. Furthermore, smaller glenoids are more vulnerable to become unstable in case of small osteochondral loosening. On the other hand, the standardly used percentage defect size based on intact diameter correlates weaker with the magnitude of instability and may therefore not be a valid parameter for judgement of shoulder instability