Aims

The ulna is an extremely rare location for primary bone tumours of the elbow in paediatrics. Although several reconstruction options are available, the optimal reconstruction method is still unknown due to the rarity of proximal ulna tumours. In this study, we report the outcomes of osteoarticular ulna allograft for the reconstruction of proximal ulna tumours.

Aims

Hyaline cartilage has a low capacity for regeneration. Untreated osteochondral lesions of the femoral head can lead to progressive and symptomatic osteoarthritis of the hip. The purpose of this study is to analyze the clinical and radiological long-term outcome of patients treated with osteochondral autograft transfer. To our knowledge, this study represents a series of osteochondral autograft transfer of the hip with the longest follow-up.

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

The clinical success of osteochondral autografts is heavily reliant on their mechanical stability, as grafts which protrude above or subside below the native cartilage can have a negative effect on the tribological properties of the joint [1]. Furthermore, high insertion forces have previously been shown to reduce chondrocyte viability [2]. Commercial grafting kits may include a dilation tool to increase the diameter of the recipient site prior to insertion. The aim of this study was to evaluate the influence of dilation on the primary stability of autografts. Six human cadaveric femurs were studied. For each femur, four 8.5 × 8mm autografts were harvested from the trochlear groove and implanted into the femoral condyles using a Smith & Nephew Osteochondral grafting kit. Two grafts were implanted into dilated recipient sites (n=12) and two were implanted with no dilation (n=12). Insertion force was measured by partially inserting the graft and applying a load at a rate of 1 mm/min, until the graft was flush with the surrounding cartilage. Push-in force was measured by applying the same load, until the graft had subsided 4mm below congruency. Significance was taken as (p<0.05). Average maximum insertion force of dilated grafts was significantly lower (p<0.001) than their non-dilated equivalent [28.2N & 176.7N respectively]. There was no significant difference between average maximum push-in force between the dilated and non-dilated groups [1062.8N & 1204.2N respectively]. This study demonstrated that significantly less force is required to insert dilated autografts, potentially minimising loss of chondrocyte viability. However, once inserted, the force required to displace the grafts below congruency remained similar, indicating a similar degree of graft stability between both groups

Aims

Orthopaedic surgery requires grafts with sufficient mechanical strength. For this purpose, decellularized tissue is an available option that lacks the complications of autologous tissue. However, it is not widely used in orthopaedic surgeries. This study investigated clinical trials of the use of decellularized tissue grafts in orthopaedic surgery.

Aims

The aim of this study was to investigate the feasibility of application of a 3D-printed megaprosthesis with hemiarthroplasty design for defects of the distal humerus or proximal ulna following tumour resection.

Aims

The aim of this study was to identify risk factors for recurrent instability of the shoulder and assess the ability to return to sport in patients with engaging Hill-Sachs lesions treated with arthroscopic Bankart repair and Hill-Sachs remplissage (ABR-HSR).

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.

Abstract. Objectives. Osteochondral grafting (OCG) is one treatment strategy for osteoarthritis with good clinical results. Decellularised tissues provide a promising alternative to standard autografts or allografts. This study aimed to compare the stability of traditional OCG and decellularised scaffolds upon initial implantation. Methods. Host cubes (N=16) were extracted from porcine femoral condyles around an artificial defect hole. Grafts (N=11) were harvested from the trochlear groove; porcine decellularized osteochondral scaffold (N=5) were prepared. Each host was secured in fixtures and submerged in PBS at 37 ºC. Each graft or scaffold was press fit into one of the hosts, then pushed in for 5 mm, using an indenter (Instron3365) and pushed out in the opposite direction for 10 mm. Parameters analysed were the force required to initiate movement (Dislodging Force) and the maximum force (Max Force). Results. The Dislodging Force of grafts (mean ± std. dev) was 133±15 N for the push in test and 109±11 N for the push out test. This was significantly higher than values for scaffolds: IN 24±1 N and OUT 26±5 N. The Max Force were also larger in the grafts than the scaffolds: IN 152±16 N vs. 41±4 N and OUT 118±14 N vs. 33±3 N. Conclusions. The force required to dislodge a graft or scaffold from a host environment was similar for the push in test and the push out test, suggesting it is a good measure of initial stability. Upon initial implantation, the decellularised scaffolds were easier to dislodge than the OCG. Previously, the decellularisation process was found to soften bone, relative stiffness may thus be an important consideration in graft fixation. A greater press fit may be necessary for decellularised scaffolds in order to achieve the same level of graft stability as natural OCG when used in vivo. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Joint surface restoration of deep osteochondral defects represents a significant unmet clinical need. Moreover, untreated lesions lead to a high rate of osteoarthritis. The current strategies to repair deep osteochondral defects such as osteochondral grafting or sandwich strategies combining bone autografts with ACI/MACI fail to generate long-lasting osteochondral interfaces. Herein, we investigated the capacity of juvenile Osteochondral Grafts (OCGs) to repair osteochondral defects in skeletally mature animals. With this regenerative model in view, we set up a new biological, bilayered, and scaffold-free Tissue Engineered (TE) construct for the repair of the osteochondral unit of the knee. Skeletally immature (5 weeks old) and mature (11 weeks old) Lewis rats were used. Cylindrical OCGs were excised from the intercondylar groove of the knee of skeletally immature rats and transplanted into osteochondral defects created in skeletally mature rats. To create bilayered TE constructs, micromasses of human periosteum-derived progenitor cells (hPDCs) and human articular chondrocytes (hACs) were produced in vitro using chemically defined medium formulations. These constructs were subsequently implanted orthotopically in vivo in nude rats. At 4 and 16 weeks after surgery, the knees were collected and processed for subsequent 3D imaging analysis and histological evaluation. Micro-computed tomography (µCT), H&E and Safranin O staining were used to evaluate the degree of tissue repair. Our results showed that the osteochondral unit of the knee in 5 weeks old rats exhibit an immature phenotype, displaying active subchondral bone formation through endochondral ossification, the absence of a tidemark, and articular chondrocytes oriented parallel to the articular surface. When transplanted into skeletally mature animals, the immature OCGs resumed their maturation process, i.e., formed new subchondral bone, partially established the tidemark, and maintained their Safranin O-positive hyaline cartilage at 16 weeks after transplantation. The bilayered TE constructs (hPDCs + hACs) could partially recapitulate the cascade of events as seen with the immature OCGs, i.e., the regeneration of the subchondral bone and the formation of the typical joint surface architecture, ranging from non-mineralized hyaline cartilage in the superficial layers to a progressively mineralized matrix at the interface with a new subchondral bone plate. Cell-based TE constructs displaying a hierarchically organized structure comprising of different tissue forming units seem an attractive new strategy to treat osteochondral defects of the knee

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

Aims

The aim of this study was to evaluate the efficacy of the surgical dislocation approach and modified trapdoor procedure for the treatment of chondroblastoma of the femoral head.

Shoulder arthritis in the young adult is a deceptive title. The literature is filled with articles that separate outcomes based on an arbitrary age threshold and attempt to provide recommendations for management and even potential criteria for implanting one strategy over another using age as the primary determinant. However, under the age of 50, as few as one out of five patients will have arthritis that can be accurately classified as osteoarthritis. Other conditions such as post-traumatic arthritis, post-surgical arthritis including capsulorrhaphy arthropathy, and rheumatoid arthritis create a mosaic of pathologic bone and soft tissue changes in our younger patients that distort the conclusions regarding “shoulder arthritis” in the young adult. In addition, we are now seeing more patients with unique conditions that are still poorly understood, including arthritis of the pharmacologically performance-enhanced shoulder. Early arthritis in the young adult is often recognised at the time of arthroscopic surgery performed for other preoperative indications. Palliative treatment is the first option, which equals “debridement.” If the procedure fails to resolve the symptoms, and the symptoms can be localised to an intra-articular source, then additional treatment options may include a variety of cartilage restoration procedures that have been developed primarily for the knee and then subsequently used in the shoulder, including microfracture, and osteochondral grafting. The results of these treatments have been rarely reported with only case series and expert opinion to support their use. When arthritis is moderate or severe in young adults, non-arthroplasty interventions have included arthroscopic capsular release, debridement, acromioplasty, distal clavicle resection, microfracture, osteophyte debridement, axillary nerve neurolysis, and bicep tenotomy or tenodesis, or some combination of these techniques. Again, the literature is very limited, with most case series less than 5 years of follow-up. The results are typically acceptable for pain relief, some functional improvement, but not restoration to completely normal function from the patient's perspective. Attempts to resurface the arthritic joint have resulted in limited benefits over a short period of time in most studies. While a few remarkable procedures have provided reasonable outcomes, they are typically in the hands of the developer of the procedure and subsequently, other surgeons fail to achieve the same results. This has been the case with fascia lata grafting of the glenoid, dermal allografts, meniscal allografts, and even biologic resurfacing with large osteochondral grafts for osteoarthritis. Most surgical interventions that show high value in terms of improvement in quality of life require 10-year follow-up. It is unlikely that any of these arthroscopic procedures or resurfacing procedures will provide outcomes that would be valuable in terms of population healthcare; they are currently used on an individual basis to try to delay progression to arthroplasty, with surgeon bias based on personal experience, training, or expert opinion. Arthroplasty in the young adult remains controversial. Without question, study after study supports total shoulder arthroplasty over hemiarthroplasty once the decision has been made that joint replacement is the only remaining option

An osteochondral defect greater than 3cm in diameter and 1cm in depth is best managed by an osteochondral allograft. If there is an associated knee deformity, then an osteotomy is performed. In our series of osteochondral allografts for large post-traumatic knee defects realignment osteotomy is performed about 60% of the time in order to off-load the transplant. To correct varus we realign the proximal tibia with an opening wedge osteotomy. To correct valgus, we realign the distal femur with a closing wedge osteotomy. Our results with osteochondral allografts for the large osteochondral defects of the knee both femur and tibia, have been excellent in 85% of patients at an average follow-up of 10 years. The Kaplan-Meier survivorship at 15 years is 72%. At an average follow-up of 22 years in 58 patients with distal femoral osteochondral allograft, 13 have been revised (22%). The 15-year survivorship was 84%. Retrieval studies of 24 fresh osteochondral grafts obtained at graft revision or conversion total knee replacement at an average of 12 years (5 – 25) revealed the following. In the areas where the graft was still intact, the cartilage was of normal thickness and architecture. Matrix staining was normal except in the superficial and upper mid zones. Chondrocytes were mostly viable but there was chondrocyte clusters and loss of chondrocyte polarity. Host bone had extended to the calcified cartilage but variable remnants of dead bone surrounded by live bone persisted. With a stable osseous base the hyaline cartilage portion of the graft can survive for up to 25 years