Characterisation of subchondral bone repair following transplantation of bioreactor-manufactured autologous osteochondral graft in a sheep model.

To date, no single approach to the treatment of osteochondral defects has resulted in satisfactory long-term outcomes, especially in a young and active human population. Emerging innovative tissue engineering strategies, including the use of composite scaffolds, novel cell sources and bioreactors, have shown promising results. However, these techniques need to be validated in translational animal models before they can be implemented in clinical practice. The aim of the present study was to analyse morphological and microarchitectural parameters during subchondral bone repair following transplantation of bioreactor-manufactured autologous osteochondral grafts in a sheep model. Animals were divided into 4 treatment groups: nasal chondrocyte (NC) autologous osteochondral grafts, articular chondrocyte (AC) autologous osteochondral grafts, cell-free scaffolds (CFS) and empty defects (EDs). After 6 weeks, 3 months and 12 months, bone remodelling was assessed by histology and micro-computed tomography (µCT). Although gradual remodelling and subchondral bone repair were seen in all groups across the time points, the best results were observed in the NC group. This was evidenced by the extent of new tissue formation and its best integration into the surrounding tissue in the NC group at all time points. This also suggested that nasal septum chondrocyte-seeded grafts adapted well to the biomechanical conditions of the loaded joint surface.

Paracrine effects of living human bone particles on the osteogenic differentiation of mesenchymal stem cells.

Bone autografting remains the clinical model of choice for resolving problematic fractures. The precise mechanisms through which the autograft promotes bone healing are unknown. The present study examined the hypothesis that cells within the autograft secrete osteogenic factors promoting the differentiation of mesenchymal stem cells (MSCs) into osteoblasts. Particles of human bone ("chips") were recovered at the time of joint replacement surgery and placed in culture. Then, conditioned media were added to cultures of human, adipose-derived MSCs under both basal and osteogenic conditions. Contrary to expectation, medium conditioned by bone chips reduced the expression of alkaline phosphatase and strongly inhibited mineral deposition by MSCs cultured in osteogenic medium. Real time PCR revealed the inhibition of collagen type I alpha 1 chain (Col1A1) and osteopontin (OPN) expression. These data indicated that the factors secreted by bone chips inhibited the osteogenic differentiation of MSCs. However, in late cultures, bone morphogenetic protein-2 (BMP-2) expression was stimulated, suggesting the possibility of a delayed, secondary osteogenic effect.

Rationale for more consistent choice of surgical approaches for acetabular fractures.

OBJECTIVES: All acetabular fractures are difficult to treat surgically, but there are four types involving two columns that are particularly challenging. The choice of surgical approach is crucial. The purpose of the study was to determine and evaluate the factors influencing the choice of surgical approach for two-column acetabular fractures. We hypothesised that more accurate preoperative planning, sophisticated technical capabilities, and evolution of surgeon experience will result in more consistent use of non-extensile single surgical approaches. We also evaluated the outcomes of surgical treatment and the correlation with the surgical approach used. DESIGN: Retrospective cohort study. PATIENTS AND METHODS: A total of 156 patients with 157 acetabular fractures involving two columns (Letournel T-types and both-column) treated surgically in a 25-year period (1988-2013) were included in the study. The acetabular fractures in this study were divided into two groups according to the date of surgery: 81 in Group 1 (1998-2002) and 76 in Group 2 (2003-2013). All fractures were classified preoperatively according to the Judet and Letournel classification system and Matta's categorisation of surgical approach. Four surgical approaches were used: single Kocher-Langenbeck (KL), single ilioinguinal (II), combined Kocher-Langenbeck and ilioinguinal (KL+II), and extended iliofemoral (EIF). The efficacy of the surgical approach utilised was assessed using three parameters: anatomical reduction, surgical time and intraoperative complications. RESULTS: There was no statistical difference between Group 1 and Group 2 in the distribution of T-type (p=0.424) and both-column (p=0.425) fractures. In Group 2 more acetabular fractures were treated through single non-extensile approaches compared with Group 1 (90.8% vs. 54.3%, p<0.001). Increase in single approach surgery resulted in shorter mean surgical time (p<0.001) and significant increase in anatomical reduction (p=0.039). The frequency of intraoperative complications was not statistically different (p=0.07) between the two groups, but there was a trend to fewer complications in Group 2. CONCLUSIONS: The surgical approaches chosen for acetabular fractures that involve two columns (Letournel T-types and both-column) should become more consistent. The results of this study indicate that the majority of such acetabular fractures can be treated successfully through single surgical approaches.

Patellar tendinopathy: histopathological examination and follow-up of surgical treatment.

PURPOSE OF THE STUDY: The aim of this study was to determine the exact localization of the histopathological process (bone, bone-tendon junction or tendon), and to determine whether the underlying pathologic process is predominantly of inflammatory or degenerative nature, then to evaluate the outcome of the surgical treatment of patellar tendinopathy. MATERIALS: A prospective cohort study was performed in order to analyze the outcome of surgical treatment of patellar tendinopathy, as well as to document histopathological changes in bone, bone-tendon junction, and in the patellar ligament in 34 professional athletes treated with patellar apicotomy. All the patients included in the study were classified as stage 3 according to Blazina and showed no improvement after at least 6 months of conservative treatment. The postoperative follow-up was from 1 to 8 years with a mean value of 4.7 years. METHODS: The postoperative results were analyzed using a semiquantitative scoring system where the functional outcome was classified as very good if the athlete returned to his sporting activity without any negative side effects, good if the athlete resumed his sporting activities with modest painful sensations present only at the maximum level of physical exertion, and poor if any reduction of athletic activity was present. In twenty patients a histopathological examination of resected bone and tendon tissue was performed. The specimens were stained with hematoxylin-eosin and examined under a light microscope using polarization. Special stains used were Alcian blue, to detect any increase in ground substance, and Prussian blue which enhances conspicuity of hyaline degeneration and enables detection of hemosiderin. Immunohistochemistry was performed in order to analyze presence of blood vessels, leukocytes and histiocytes. RESULTS: Very good results were achieved in 20 of operated knees, good results were achieved in 12 of knees and poor results were achieved in 2 of operated knees. Pathological changes in the bone were found in 35% of analyzed specimens, abnormality at the bone-tendon junction were found in 75% of the specimens, and changes in the patellar tendon were found in all extracted specimens. The histopatholological nature of the lesions found within the tendon tissue in all of the analyzed specimens belongs to the group of degenerative changes. DISCUSSION: Currently a consenus has been established that the expression tendinitis is "out", and the term tendinopathy should be used instead. No inflammatory cells and no increase in prostaglandins can be detected in the tendons. Histopathological studies of the tissue fibrils affected by tendinosis characteristically demonstrate hypercellularity, hypervascularity, lack of inflammatory infiltrates, and disorganization and loosening of collagen fibers. CONCLUSION: The clinical results and histopathological examination in our series justified our operative method. In the chronic stage these lesions are irreversible and constitute permanent intratendinous lesions. It thus seems logical to excise these lesions from their origin at the apex of the patella and entry into the adjacent tendon. It is also recommended on the basis of our and other authors' research that the term patellar tendinopathy should be used instead of tendonitis/tendinitis.

Articular cartilage repair by genetically modified bone marrow aspirate in sheep.

Bone marrow presents an attractive option for the treatment of articular cartilage defects as it is readily accessible, it contains mesenchymal progenitor cells that can undergo chondrogenic differentiation and, once coagulated, it provides a natural scaffold that contains the cells within the defect. This study was performed to test whether an abbreviated ex vivo protocol using vector-laden, coagulated bone marrow aspirates for gene delivery to cartilage defects may be feasible for clinical application. Ovine autologous bone marrow was transduced with adenoviral vectors containing cDNA for green fluorescent protein or transforming growth factor (TGF)-beta1. The marrow was allowed to clot forming a gene plug and implanted into partial-thickness defects created on the medial condyle. At 6 months, the quality of articular cartilage repair was evaluated using histological, biochemical and biomechanical parameters. Assessment of repair showed that the groups treated with constructs transplantation contained more cartilage-like tissue than untreated controls. Improved cartilage repair was observed in groups treated with unmodified bone marrow plugs and Ad.TGF-beta1-transduced plugs, but the repaired tissue from TGF-treated defects showed significantly higher amounts of collagen II (P<0.001). The results confirmed that the proposed method is fairly straightforward technique for application in clinical settings. Genetically modified bone marrow clots are sufficient to facilitate articular cartilage repair of partial-thickness defects in vivo. Further studies should focus on selection of transgene combinations that promote more natural healing.

One-stage operation for locked bilateral posterior dislocation of the shoulder.

A man of 52 years of age had a grand mal seizure. He presented to our unit three months later with irreducible bilateral posterior dislocation of the shoulder. CT scans revealed large compression defects on the anteromedial aspect of the heads of both humeri. The defect on the right side was of more than 50% of the articular surface, and on the left side of 40%. He was treated by a one-stage operation with a hemiarthroplasty on one side and reconstruction of the head by an osteochondral autograft on the other. Three years later the clinical and radiological results were excellent.

Current concepts in gene therapy of the musculoskeletal system.

The purpose of this article is to review the remarkable progress in the field of musculoskeletal system gene therapy. Since the introduction of this concept 15 years much of the preclinical and clinical data have emerged. The original target, rheumatoid arthritis, has been subjected to clinical phase II efficacy protocol, and osteoarthritis gene therapy efficacy is being thoroughly investigated in various animal models. The most promising area of research in this field however, is the tissue repair, because it doesn't require prolonged period of gene expression, local delivery is reasonably simple and it avoids substantial risk associated with systemic delivery, and levels of gene expression don't need to be so finely regulated. Gene transfer is successfully being used to aid the repair and regeneration of bone, cartilage, ligament tendon, meniscus and intervertebral disc. Other potential applications of gene therapy in musculoskeletal system include osteoporosis, aseptic loosening, genetic diseases and tumors. Highly encouraging data gained from these studies have confirmed that gene therapy is a promising therapeutic solution to treat various musculoskeletal system disorders.

Stress fractures of the femoral shaft in athletes: a new treatment algorithm.

BACKGROUND: Femoral shaft stress fractures in athletes are not common but pose a great diagnostic challenge to clinicians. Because of few clinical signs, diagnosis and treatment are often delayed. Furthermore, if not treated correctly, these fractures are well known for complications and difficulties. OBJECTIVE: To develop a well structured and reproducible treatment algorithm for athletes with femoral shaft stress fractures. METHODS: The proposed algorithm is carried out in four phases, each lasting three weeks, and the move to the next phase is based on the result of the tests carried out at the end of the previous phase. Over nine years, we treated seven top level athletes, aged 17-21. In all athletes, diagnosis was based on physical examination, plain radiographs, and bone scan. RESULTS: As a result of the treatment method, all the athletes were fully engaged in athletic activity 12-18 weeks after the beginning of treatment. After completion of the treatment, the athletes were followed up for 48-96 months. During the follow up, there was no recurrence of discomfort or pain, and all the athletes eventually returned to competition level. CONCLUSION: These results and data available from the literature suggest that the algorithm is the optimal treatment protocol for femoral shaft stress fractures in athletes, avoiding the common complications and difficulties.

Localized pigmented villonodular synovitis of the knee: diagnostic challenge and arthroscopic treatment: a report of three cases.

The localized form of pigmented villonodular synovitis (LPVS) is a lesion characterized by focal involvement of the synovial membrane. The knee is the most commonly affected joint. We report three cases of LPVS of the knee which were not diagnosed upon clinical evaluation. The aim is to bring the attention of clinicians to this pathological entity, which is often regarded as extremely rare and is therefore not considered in the early differential diagnosis of various knee derangements. Diagnostic and therapeutic arthroscopy was performed. The lesions were completely resected and patohistological findings confirmed the diagnosis of LPVS. All of our three patients have remained asymptomatic at 8, 10, and 12-month follow-ups.

[The female athlete triad]. / Trijas sportasica.

This review offers some basic information on a syndrome described in 1992 as the female athlete triad. The increasing participation of women in competitive sports has led to significant accumulation of knowledge about potential pathological conditions due to strenuous exercise. Participation in sports that emphasize specific body image, psychological constitution of young female athletes and significantly lower daily calory intake cause the development of disordered eating, especially anorexia nervosa. Anorexia in combination with intensive training induces menstrual disorders, exercise-associated amenorrhea being the most important one. Low serum estrogen concentrations, as well as insufficient daily calcium intake have negative influence on bone mineral density, and the athletes have greater risk of developing osteoporosis and stress fractures. We described the diagnostic and therapeutic procedures necessary to detect and treat this syndrome. Education of physicians, female athletes and their coaches, as well as the screening during the annual examination, remain the most important measures of prevention.