Infection following bone tumor resection and reconstruction with tumoral prostheses: a literature review.

Bone resection is the choice treatment of malignant bone tumors. Tumor prosthesis is one of the most common solutions of reconstruction following resection of bone tumor located to the metaphysis of long bones. Periprosthetic infections are a frequent complication of limb-salvage surgery which is largely due to prolonged and repeated surgeries, as well as to the immunocompromised condition of these patients due to neoplastic treatment. Furthermore, the large exposure of tissues during this type of surgery and the dissection across vascular distributions also contributes to the high risk of infection. The authors reviewed the literature discussing the incidence of infections of tumor prosthesis implanted following resection of bone tumors, taking into account the different sites of implantation. In the English literature, the highest risk of infection which led to limb amputation was observed after proximal tibia resection and this difference was considered to be due to the poor condition of soft tissue and also after pelvic resection due to huge dead space after sarcoma resection not filled by implant. Independent of the location, the management of infected prosthesis is similar. That is, after one or more attempts at debridement and antibiotic therapy, it consists of implant removal and insertion of a new implant in a one- or two-stage procedure, with a decreased risk of failure with the two-stage procedure

Neoadjuvant multidrug chemotherapy including High-Dose Methotrexate modifies VEGF expression in Osteosarcoma: an immunohistochemical analysis

<p>Abstract</p> <p>Background</p> <p>Angiogenesis plays a role in the progression of osteosarcoma, as well as in other mesenchymal tumors and carcinomas, and it is most commonly assessed by vascular endothelial growth factor (VEGF) expression or tumor CD31-positive microvessel density (MVD). Tumor VEGF expression is predictive of poor prognosis, and chemotherapy can affect the selection of angiogenic pattern. The aim of the study was to investigate the clinical and prognostic significance of VEGF and CD31 in osteosarcoma, both at diagnosis and after neoadjuvant chemotherapy, in order to identify a potential role of chemotherapy in angiogenic phenotype.</p> <p>Methods</p> <p>A retrospective analysis was performed on 16 patients with high grade osteosarcoma. In each case archival pre-treatment biopsy tissue and post-chemotherapy tumor specimens were immunohistochemically stained against CD31 and VEGF, as markers of angiogenic proliferation both in newly diagnosed primary osteosarcoma and after multidrug chemotherapy including high-dose methotrexate (HDMTX). The correlation between clinicopathological parameters and the degree of tumor VEGF and CD31 expression was statistically assessed using the χ²test verified with Yates' test for comparison of two groups. Significance was set at <it>p </it>< 0,05.</p> <p>Results</p> <p>Expression of VEGF was positive in 11 cases/16 of cases at diagnosis. Moreover, 8 cases/16 untreated osteosarcomas were CD31-negative, but the other 8 showed an high expression of CD31. VEGF expression in viable tumor cells after neoadjuvant chemotherapy was observed in all cases; in particular, there was an increased VEGF expression (post-chemotherapy VEGF - biopsy VEGF) in 11 cases/16. CD31 expression increased in 11 cases/16 and decreased in 3 cases after chemotherapy. The data relating to the change in staining following chemotherapy appear statistically significant for VEGF expression (<it>p </it>< 0,05), but not for CD31 (<it>p </it>> 0,05).</p> <p>Conclusions</p> <p>Even if the study included few patients, these results confirm that VEGF and CD31 expression is affected by multidrug chemotherapy including HDMTX. The expression of angiogenic factors that increase microvessel density (MVD) can contribute to the penetration of chemotherapeutic drugs into the tumor in the adjuvant stage of treatment. So VEGF could have a paradoxical effect: it is associated with a poor outcome but it could be a potential target for anti-angiogenic therapy.</p

Morphology of the toe flexor muscles in older people with toe deformities

Objective: Despite suggestions that atrophied, or weak toe flexor muscles are associated with the formation of toe deformities, there has been little evidence to support this theory. This study aimed to determine whether the size of the toe flexor muscles differed in older people with and without toe deformities. Methods: Forty-four older adults (&gt;60 years) were recruited for the study. Each participant had their feet assessed for the presence of hallux valgus or lesser toe deformities. Intrinsic and extrinsic toe flexor muscles were imaged with an ultrasound system using a standardised protocol. Assessor blinded muscle thickness and cross-sectional area was measured using Image J software. Results: Participants with lesser toe deformities (n=20) were found to have significantly smaller quadratus plantae (p=0.003), flexor digitorum brevis (p=0.013), abductor halluces (p=0.004) and flexor halluces brevis (p=0.005) muscles than the participants without any toe deformities (n=19). Female participants with hallux valgus (n=10) were found to have significantly smaller abductor hallucis (p=0.048) and flexor halluces brevis (p=0.013) muscles than the female participants without any toe deformities (n=10; p&lt;0.05). Conclusion: This is the first study to use ultrasound to investigate the size of the toe flexor muscles in older people with hallux valgus and lesser toe deformities compared to otherwise healthy older adults. The size of the abductor hallucis and flexor hallucis brevis muscles were decreased in participants with hallux valgus whereas the quadratus plantae, flexor digitorum brevis, abductor hallucis and flexor halluces brevis muscles were smaller in those participants with lesser toe deformities

Graft-tunnel healing

Several experimental studies have shown that bone\u2013tendon p0310 graft healing in ACL reconstruction occurs in a period varying from 3 to 12 weeks. The quality and rate of healing depend on many variables, predominantly the type of graft. Soft tissue grafts such as hamstring tendon grafts heal within a bone tunnel by formation of a fibrous transitional layer between the tendon and bone, which contains penetrating Sharpey-like fibers. This newly formed bone\u2013 tendon interface matures with time and resembles the indirect-type insertion observed in tendons and ligaments. Bone plug tendon grafts, such as patellar tendon, heal within bone tunnel by incorporation of the bone plug to the surrounding bone and formation of an indirect-type insertion at the interface between bone and the intraosseous fibrous portion of the graft. Bone\u2013bone healing occurs more rapidly than tendon\u2014bone healing. Resistance to pullout force appears to be similar between the two types of grafts by 8 to 12 weeks after surgery. Therefore soft tissue grafts need high primary fixation strength and stiffness because of the consistent risk of failure due to pullout from the tunnel during the first 2 months. Mechanical stresses can affect maturation and differentiation of the bone\u2013tendon graft junction depending on many factors such as bone density, fixation, placement and tensioning of the graft, gap size, and postoperative immobilization. Compression of the graft within the tunnel can enhance healing for both the bone plug and soft tissue. However, during the first 3 months after an ACL reconstruction, regardless of the type of graft used, the strength of the bone\u2013tendon graft junction does not influence the mechanical behavior of the femur\u2013ACL graft\u2013tibia complex because the weak link of the ligament replacement rapidly shifts from the fixation site to the midsubstance of the graft. Therefore the application of excessive loads during this period, such as a too-aggressive rehabilitation and early return to sport activities, may cause a permanent elongation of the graft, thus compromising the result of the reconstruction. Many efforts have been made to improve the quality and rate of bone\u2013tendon healing. Tissue engineering and gene transfer techniques have been applied to obtain a direct-type fibrocartilaginous insertion of the ACL graft, similar to that of the native ligament, and to accelerate the healing process of tendon grafts within bone tunnel. However, more investigations will be necessary in the near future to evaluate the possible employment of these biological techniques in the clinical practice

Histological analysis of the coracoacromial arch: correlation between age-related changes and rotator cuff tears

The purpose of this study was to analyze age-related changes in the coracoacromial arch and correlate these degenerative changes with rotator cuff tears. We obtained 80 shoulders from 40 cadavers. The mean age at death was 58.4 years. We performed a gross examination of the rotator cuff and the acromion and histological examination of the coracoacromial ligament. The statistical significance of any difference for each group considered was determined by Student's t-test. The rotator cuff was normal in 66 specimens; there was an articular-side partial tear in 4 cases, a bursal-side partial tear in 6 cases, and a full-thickness tear in 4 cases. Age was correlated with increasing incidence and severity of cuff tears. We noted age-related degenerative changes in the coracoacromial ligament, degeneration of the acromial bone-ligament junction, and acromial spur formation. Anterior acromial spur was not related to the morphology of the acromion. We observed an increased incidence of bursal-side and complete cuff tears when the acromion was curved or beaked. Degenerative changes in the undersurface of the acromion were also present when the rotator cuff was normal. Bursal-side and complete cuff tears were associated with severe degenerative changes in the acromion in 100% of cases. Articular-side cuff tears were not related either to acromial morphology or degenerative changes in the coracoacromial arch. The association between cuff tears and acromial spur was more evident in the presence of a type III acromion. Our results would suggest that the incidence and severity of rotator cuff tears are correlated with aging and with the morphology of the acromion. Rotator cuff tears that involve the bursal side are often associated with changes in the coracoacromial ligament and the undersurface of the acromion. However, degenerative changes in the coracoacromial arch are always related to aging, also in the presence of a normal rotator cuff. Articular-side partial tears do not cause damage to the undersurface of the acromion