We used demineralised bone matrix (DBM) to augment re-attachment of tendon to a metal prosthesis in an in vivo ovine model of reconstruction of the extensor mechanism at the knee. We hypothesised that augmentation of the tendon-implant interface with DBM would enhance the functional and histological outcomes as compared with previously reported control reconstructions without DBM. Function was assessed at six and 12 weeks postoperatively, and histological examination was undertaken at 12 weeks. A significant increase of 23.5% was observed in functional weight-bearing at six weeks in the DBM-augmented group compared with non-augmented controls (p = 0.004). By 12 weeks augmentation with DBM resulted in regeneration of a more direct-type enthesis, with regions of fibrocartilage, mineralised fibrocartilage and bone. In the controls the interface was predominantly indirect, with the tendon attached to the bone graft-hydroxyapatite base plate by perforating collagen fibres

Aims

Periprosthetic joint infection (PJI) occurs in approximately 1% to 2% of total knee arthroplasties (TKA) presenting multiple challenges, such as difficulty in diagnosis, technical complexity, and financial costs. Two-stage exchange is the gold standard for treating PJI but emerging evidence suggests 'two-in-one' single-stage revision as an alternative, delivering comparable outcomes, reduced morbidity, and cost-effectiveness. This study investigates five-year results of modified single-stage revision for treatment of PJI following TKA with bone loss.

We studied the effect of vitamin C on fracture healing in the elderly. A total of 80 elderly Osteogenic Disorder Shionogi rats were divided into four groups with different rates of vitamin C intake. A closed bilateral fracture was made in the middle third of the femur of each rat. Five weeks after fracture the femora were analysed by mechanical and histological testing. The groups with the lower vitamin C intake demonstrated a lower mechanical resistance of the healing callus and a lower histological grade. The vitamin C levels in blood during healing correlated with the torque resistance of the callus formed (r = 0.525). Therefore, the supplementary vitamin C improved the mechanical resistance of the fracture callus in elderly rats. If these results are similar in humans, vitamin C supplementation should be recommended during fracture healing in the elderly

Aims. The aim of this study was to analyse human muscle tissue before and after rotator cuff repair to look for evidence of regeneration, and to characterise the changes seen in the type of muscle fibre. Patients and Methods. Patients were assessed pre-operatively and one year post-operatively using the Oxford Shoulder Score (OSS) and MRI. The cross-sectional area and distribution of the type of muscle fibre were assessed on biopsies, which were taken at surgery and one year post-operatively. Paired samples from eight patients were analysed. There were three men and five women with a mean age of 63 years (50 to 73). Results. All but one patient showed improvement in OSS (p = 0.004). The mean increase in the cross-sectional area of the muscle was 1220 μm. 2. (-801 to 3712; p = 0.03). There was a reduction of type 2a fibres (p = 0.02). A clear relationship could not be seen between the MRI findings and the histological appearances. Conclusion. This is the first study to provide evidence that atrophy of the supraspinatus muscle is reversible. Changes in the types of fibre are discussed. MRI assessment of muscle atrophy may not be fully representative of myofibre atrophy. Cite this article: Bone Joint J 2016;98-B:1389–94

Aims. The purpose of this study was to review a large cohort of patients and further assess the correlation between the histological response to chemotherapy in patients with Ewing’s sarcoma with the overall (OS) and event-free survival (EFS). Patients and Methods. All patients treated for Ewing’s sarcoma between 1980 and 2012 were reviewed. Of these, 293 patients without metastases at the time of diagnosis and treated with chemotherapy and surgery were included. Patients were grouped according to the percentage of necrosis after chemotherapy: Group I: 0% to 50%, Group II: 51% to 99% and Group III: 100%. Results. The mean age at diagnosis was 16 years (1 to 62) and the mean follow-up was 9.1 years (six months to 32.6 years). The OS and EFS for the series were 75% and 65% at five years. There were significant differences in survival between the groups of necrosis: 0% to 50% (OS: 49% and EFS: 45% at five years, respectively) compared with 51% to 99% (OS: 72% and EFS: 59% at five years, respectively) and 100% (OS: 94% and EFS: 81% at five years, respectively) (p <  0.001). There were no significant differences in survival between patients treated between 1980 and 1989 compared with those treated between 1990 and 1999, and those treated between 2000 and 2012 (p = 0.55). Conclusion. Only patients with 100% necrosis after chemotherapy should be classified as having a good response to chemotherapy because they have significantly better rates of survival compared with those with any viable tumour in the surgical specimen. Cite this article: Bone Joint J 2016;98-B:1138–44

Aims

In the repair of condylar cartilage injury, synovium-derived mesenchymal stem cells (SMSCs) migrate to an injured site and differentiate into cartilage. This study aimed to confirm that histone deacetylase (HDAC) inhibitors, which alleviate arthritis, can improve chondrogenesis inhibited by IL-1β, and to explore its mechanism.

Aims

The aim of this study was to present the first retrieval analysis findings of PRECICE STRYDE intermedullary nails removed from patients, providing useful information in the post-market surveillance of these recently introduced devices.

Aims. Myxofibrosarcomas (MFSs) are malignant soft-tissue sarcomas characteristically presenting as painless slowly growing masses in the extremities. Locally infiltrative growth means that the risk of local recurrence is high. We reviewed our experience to make recommendations about resection strategies and the role of the multidisciplinary team in the management of these tumours. Patients and Methods. Patients with a primary or recurrent MFS who were treated surgically in our unit between 1997 and 2012 were included in the study. Clinical records and imaging were reviewed. A total of 50 patients with a median age of 68.4 years (interquartile range 61.6 to 81.8) were included. There were 35 men; 49 underwent surgery in our unit. Results. The lower limb was the most common site (32/50, 64%). The mean size of the tumours was 8.95 cm (1.5 to 27.0); 26 (52%) were French Fédération Nationale des Centres de Lutte Contre le Cancer grade III. A total of 21 (43%) had positive margins after the initial excision; 11 underwent further excision. Histology showed microscopic spread of up to 29 mm beyond macroscopic tumour. Local recurrence occurred in seven patients (14%) at a mean of 21 months (3 to 33) and 15 (30%) developed metastases at a mean of 17 months (3 to 30) post-operatively. Conclusion. High rates of positive margins and the need for further excision makes this tumour particularly suited to management by multidisciplinary surgical teams. Microscopic tumour can be present up to 29 mm from the macroscopic tumour in fascially-based tumours. Cite this article: Bone Joint J 2016;98-B:1682–8

Four uncemented Symax hip stems were extracted at three weeks and nine, 13 and 32 months, respectively, for reasons other than loosening. The reasons for implant removal were infection in two cases, recurrent dislocation in one and acetabular fracture in one. They were analysed to assess the effect and behaviour of an electrochemically deposited, completely resorbable biomimetic BONIT-hydroxyapatite (HA) coating (proximal part) and a DOTIZE surface treatment (distal part) using qualitative histology, quantitative histomorphometry and scanning electron microscopy (SEM). Early and direct bone-implant bonding with signs of active remodelling of bone and the HA coating were demonstrated by histology and SEM. No loose BONIT-HA particles or delamination of the coating were observed, and there was no inflammation or fibrous interposition at the interface. Histomorphometry showed bone-implant contact varying between 26.5% at three weeks and 83.5% at 13 months at the HA-coated implant surface. The bone density in the area of investigation was between 24.6% at three weeks and 41.1% at 32 months. The DOTIZE surface treatment of the distal part of the stem completely prevented tissue and bone apposition in all cases, thereby optimising proximal stress transfer. The overall features of this implant, in terms of geometry and surface texture, suggest a mechanically stable design with a highly active biomimetic coating, resulting in rapid and extensive osseo-integration, exclusively in the metaphyseal part of the stem. Early remodelling of the HA coating does not seem to have a detrimental effect on short-term bone-implant coupling. There were no adverse effects identified from either the BONIT-HA coating or the DOTIZE surface treatment

Osteofibrous dysplasia is an unusual developmental condition of childhood, which almost exclusively affects the tibia. It is thought to follow a slowly progressive course and to stabilise after skeletal maturity. The possible link with adamantinoma is controversial and some authors believe that they are part of one histological process. We retrospectively reviewed 16 patients who were diagnosed as having osteofibrous dysplasia initially or on the final histological examination. Their management was diverse, depending on the severity of symptoms and the extent of the lesion. Definitive (extraperiosteal) surgery was localised ‘shark-bite’ excision for small lesions in five patients. Extensive lesions were treated by segmental excision and fibular autograft in six patients, external fixation and bone transport in four and proximal tibial replacement in one. One patient who had a fibular autograft required further excision and bone transport for recurrence. Six initially underwent curettage and all had recurrence. There were no recurrences after localised extraperiosteal excision or bone transport. There were three confirmed cases of adamantinoma. The relevant literature is reviewed. We recommend extraperiosteal excision in all cases of osteofibrous dysplasia, with segmental excision and reconstruction in more extensive lesions

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Cell-free DNA (cfDNA) and circulating tumour DNA (ctDNA) are used for prognostication and monitoring in patients with carcinomas, but their utility is unclear in sarcomas. The objectives of this pilot study were to explore the prognostic significance of cfDNA and investigate whether tumour-specific alterations can be detected in the circulation of sarcoma patients.

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MRI has been suggested as an objective method of assessing anterior crucate ligament (ACL) graft “ligamentization” after reconstruction. It has been proposed that the MRI appearances could be used as an indicator of graft maturity and used as part of a return-to-sport assessment. The aim of this study was to evaluate the correlation between MRI graft signal and postoperative functional scores, anterior knee laxity, and patient age at operation.

We developed a new porous scaffold made from a synthetic polymer, poly(DL-lactide-co-glycolide) (PLG), and evaluated its use in the repair of cartilage. Osteochondral defects made on the femoral trochlear of rabbits were treated by transplantation of the PLG scaffold, examined histologically and compared with an untreated control group. Fibrous tissue was initially organised in an arcade array with poor cellularity at the articular surface of the scaffold. The tissue regenerated to cartilage at the articular surface. In the subchondral area, new bone formed and the scaffold was absorbed. The histological scores were significantly higher in the defects treated by the scaffold than in the control group (p < 0.05). Our findings suggest that in an animal model the new porous PLG scaffold is effective for repairing full-thickness osteochondral defects without cultured cells and growth factors

Osteochondroma is the most common benign bone tumour. The risk of sarcomatous change in an isolated lesion is approximately 1%. We report a case of an isolated osteochondroma which appeared benign on clinical and plain radiographic examination but routine histological analysis revealed non-Hodgkin’s lymphoma in the underlying bone. This association has not previously been reported and the case emphasises the importance of routine histological analysis, even if a lesion appears benign

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While a centralized system for the care of patients with a sarcoma has been advocated for decades, regional variations in survival remain unclear. The aim of this study was to investigate regional variations in survival and the impact of national policies in patients with a soft-tissue sarcoma (STS) in the UK.

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Long-term outcomes following the use of human dermal allografts in the treatment of symptomatic irreparable rotator cuff tears are not known. The aim of this study was to evaluate these outcomes, and to investigate whether this would be a good form of treatment in young patients in whom a reverse shoulder arthroplasty should ideally be avoided.

Ovine articular chondrocytes were isolated from cartilage biopsy and culture expanded in vitro. Approximately 30 million cells per ml of cultured chondrocytes were incorporated with autologous plasma-derived fibrin to form a three-dimensional construct. Full-thickness punch hole defects were created in the lateral and medial femoral condyles. The defects were implanted with either an autologous ‘chondrocyte-fibrin’ construct (ACFC), autologous chondrocytes (ACI) or fibrin blanks (AF) as controls. Animals were killed after 12 weeks. The gross appearance of the treated defects was inspected and photographed. The repaired tissues were studied histologically and by scanning electron microscopy analysis. All defects were assessed using the International Cartilage Repair Society (ICRS) classification. Those treated with ACFC, ACI and AF exhibited median scores which correspond to a nearly-normal appearance. On the basis of the modified O’Driscoll histological scoring scale, ACFC implantation significantly enhanced cartilage repair compared to ACI and AF. Using scanning electron microscopy, ACFC and ACI showed characteristic organisation of chondrocytes and matrices, which were relatively similar to the surrounding adjacent cartilage. Implantation of ACFC resulted in superior hyaline-like cartilage regeneration when compared with ACI. If this result is applicable to humans, a better outcome would be obtained than by using conventional ACI

Aims. Massive endoprostheses rely on extra-cortical bone bridging (ECBB) to enhance fixation. The aim of this study was to investigate the role of selective laser sintered (SLS) porous collars in augmenting the osseointegration of these prostheses. Materials and Methods. The two novel designs of porous SLS collars, one with small pores (Ø700 μm, SP) and one with large pores (Ø1500 μm, LP), were compared in an ovine tibial diaphyseal model. Osseointegration of these collars was compared with that of a clinically used solid, grooved design (G). At six months post-operatively, the ovine tibias were retrieved and underwent radiological and histological analysis. Results. Porous collars provided a significantly greater surface (p < 0.001) for the ingrowth of bone than the standard grooved design. Significantly greater extracortical pedicle formation was seen radiologically around the grooved design (length p = 0.002, thickness p < 0.001, surface area p = 0.002) than around the porous collars. However, the ingrowth of bone occurred from the transection site into the porous structure of both types of collar. A fivefold increase in integration was seen with the SP and a threefold increase in the LP design when compared with G (p < 0.001). Conclusion. SLS porous collars allow the direct ingrowth of more bone and are better than current designs which rely on surface ongrowth and ECBB. Cite this article: Bone Joint J 2017;99-B:276–82

Aims

We have previously reported cryoablation-assisted joint-sparing surgery for osteosarcoma with epiphyseal involvement. However, it is not clear whether this is a comparable alternative to conventional joint arthroplasty in terms of oncological and functional outcomes.