Carlos Alberto de Souza Macedo

In vItro And In vIvo EvAluAtIon of lyopHIlIzEd BovInE BonE BIoCompAtIBIlIty

INTRODUCTION The use of bone grafts in orthopedic, maxillofacial and dental surgery has been growing. Nevertheless, both fresh autografts and frozen allografts have limitations, and therefore, alternative synthetic or natural biomaterials, such as processed and lyophilized bovine bone graft have been developed. OBJECTIVE To evaluate in vitro and in vivo biocompatibility of lyophilized bovine bone manufactured in a semi-industrial scale, according to a modifical protocol developed by the authors. METHODS Samples of bovine cancellous bone were processed according to a protocol developed by Kakiuchi et al., and modified to process samples of bovine cancellous bone. The following trials were performed: in vitro cytotoxicity, in vivo acute systemic toxicity, in vivo oral irritation potential, in vitro pyrogenic reaction, and bioburden. RESULTS The in vitro evaluation of lyophilized bovine cancellous bone revealed an absence of cytotoxicity in 100% of the samples. Regarding in vivo evaluation of acute systemic toxicity, neither macroscopic abnormalities nor deaths were noted in the animals. Pyrogenicity was not greater than 0.125 UE/ml in any of the samples. The bioburden revealed negative results for microbial growth before sterilization. Regarding the oral irritation potential, in vivo evaluation at 24 and 72 hours showed that the animals had no edema or erythema on the oral mucosa. CONCLUSION The protocol changes established by the authors to prepare lyophilized bovine cancellous bone at a semi-industrial scale is reproducible and yielded a product with excellent biocompatibility.

Coxa profunda in the diagnosis of pincer-type femoroacetabular impingement and its prevalence in asymptomatic subjects.

In many papers, the diagnosis of pincer-type femoroacetabular impingement (FAI) is attributed to the presence of coxa profunda. However, little is known about the prevalence of coxa profunda in the general population and its clinical relevance. In order to ascertain its prevalence in asymptomatic subjects and whether it is a reliable indicator of pincer-type FAI, we undertook a cross-sectional study between July and December 2013. A total of 226 subjects (452 hips) were initially screened. According to strict inclusion criteria, 129 asymptomatic patients (257 hips) were included in the study. The coxa profunda sign, the crossover sign, the acetabular index (AI) and lateral centre-edge (LCE) angle were measured on the radiographs. The median age of the patients was 36.5 years (28 to 50) and 138 (53.7%) were women. Coxa profunda was present in 199 hips (77.4%). There was a significantly increased prevalence of coxa profunda in women (p < 0.05) and a significant association between coxa profunda and female gender (p < 0.001) (92% vs 60.5%). The crossover sign was seen in 36 hips (14%), an LCE > 40° in 28 hips (10.9%) and an AI < 0º in 79 hips (30.7%). A total of 221 normal hips (79.2%) (normal considering the crossover) had coxa profunda, a total of 229 normal hips (75.5%) (normal considering the LCE) had coxa profunda and a total of 178 normal hips (75.3%) (normal considering AI) had coxa profunda. When the presence of all radiological signs in the same subject was considered, pincer-type FAI was found in only two hips (one subject). We therefore consider that the coxa profunda sign should not be used as a radiological indicator of pincer-type FAI. We consider profunda to be a benign alteration in the morphology of the hip with low prevalence and a lack of association with other radiological markers of FAI. We suggest that the diagnosis of pincer-type FAI should be based on objective measures, in association with clinical findings.

The prevalence of femoroacetabular impingement in radiographs of asymptomatic subjects: a cross-sectional study.

Background There is a lack of uniformity in the diagnostic criteria for femoroacetabular impingement (FAI), and few studies discuss the prevalence of radiographic changes in asymptomatic individuals. These factors make it difficult to establish a natural history of this disease. The aim of this study was to assess the prevalence of radiographic signs of CAM and Pincer FAI in an asymptomatic population. Methods A cross-sectional study was performed from July 2013 to December 2013. A total of 185 subjects were analysed. Inclusion criteria: no history of hip pain or orthopedic disease; and being 20-60 years old. Exclusion criteria: athletically active; or patients who would not allow acquisition of appropriate radiographs for analysis. Radiographs were obtained in anteroposterior and Dünn 45° view to access: alpha angle (AA), triangular index (TI), crossover sign (CS), lateral-centre edge (LCE) angle and acetabular index (AI). Results Median age was 34 years (27-49.5) and FAI was present in 53% of all subjects. 32.44% (60) was the overall CAM-type prevalence and 42.7% (79) the overall Pincer-type prevalence. Only 2 subjects presented the 3 overcoverage signs (AI, LCE and CS). An association was noted between the presence of AI <0° and the LCE >40° (p = 0.05). Conclusions Our study established a higher prevalence of radiographic markers of FAI in an asymptomatic population.

Prevalence of radiographic markers of femoroacetabular impingement in asymptomatic adults

OBJECTIVE to determine the prevalence of radiographic signs of femoroacetabular impingement (FAI) in asymptomatic adults and correlate them with data from physical examinations. METHODS We conducted a cross-sectional study with 82 asymptomatic volunteers, 164 hips, between 40 and 60 years of age, selected by convenience. They were submitted to anamnesis and clinical examination of the hip, anteroposterior (AP) pelvis radiographs with three incidences, Dunn 45° and Lequesne false profile of each hip, to measure the variables. We measured the alpha angle, anterior offset of the femoral neck, cervical diaphyseal angle, CE angle of Wiberg, acetabular index, Sharp angle, and the crossing, ischial spine and posterior wall signs. RESULTS our sample consisted of 66% women, mean age of 50.4 years. The average alpha angle was 45.10°, SD=8.6. One quarter of the hips showed alpha angle greater than or equal to 50°; among men the prevalence was 34%, and among women, 11%. We found indicative radiographic signs of femoroacetabular impingement in 42.6% of hips, whether femoral or acetabular, and the increased alpha angle was related to the decrease in hip internal rotation (p<0.001). CONCLUSION the radiographic findings of femoroacetabular impingement in asymptomatic patients were frequent in the studied sample. The increase in alpha angle was associated with decreased internal rotation.

Acetabular reconstruction with human and bovine freeze-dried bone grafts and a reinforcement device

BACKGROUND This is a cohort trial (1997–2005) of 49 patients submitted to an acetabular component revision of a total hip arthroplasty, using impacted human and bovine freeze-dried cancellous bone grafts (H&FDBG) and a reinforcement device. OBJECTIVE To compare clinical/radiographic graft incorporation capability between cancellous bone grafts. PATIENTS/METHODS There were two groups: I (n=26) receiving human grafts and II (n=25) receiving bovine grafts. The average follow-up times were 55 and 49 months, respectively. Clinical analysis was based on the Merle d’Aubigné and Postel score, and the radiographic analysis involved an established score based on Conn’s et al. criteria for radiographic bone incorporation. RESULTS No clinical/radiographic differences were found between the groups and both showed an overall rate of 88.5% and 76% of graft incorporation (p=0.424). CONCLUSION The results presented here are comparable to those in the literature with the use of deep-FG. Therefore, cancellous bone grafts can be safely and adequately used in acetabular component revision in total hip arthroplasty.

Femoral and acetabular revision using impacted nondemineralized freeze-dried bone allografts

BackgroundFavorable results have been obtained by the use of deep-frozen bone allografts in total hip arthroplasty. However, owing to the shortage of deep-frozen allografts and the risk of infectious disease, other materials have been studied, such as sterile nondemineralized freeze-dried allografts. The aim of this study was to describe midterm clinical outcomes and radiographic bone incorporation of human freeze-dried bone grafts in 42 revision total hip arthroplasty procedures using cancellous impacted bone grafting.MethodsThis report presented clinical and radiographic evidence of allograft incorporation in 42 hip reconstructions performed between 1996 and 2002. The patient group included 13 (31%) men and 29 (69%) women with mean ± SD age of 63 ± 14 years (range 28–80 years). Meanfollow-upwas 82 months (range 63–127) months. Clinical analysis was based on the D’Aubigné-Postel score. Radiographic incorporation was defined according to specific criteria.ResultsThe D’Aubigné and Postel criteria showed adequate outcome in 38 (90%) of the patients. The radiographic evaluation revealed that allograft remodeling and incorporation were found in 39 (93.0%) and 36 (86.5%) of acetabular and femoral cases, respectively. The overall graft survival rate at an average follow-up of 8 years (range 5–10 years) was 90%.ConclusionsBone grafts obtained by the lyophilization process developed and carried out in our tissue bank provide suitable grafts for revision total hip arthroplasty. Clinical and radiographic midterm results were excellent, indicating that nondemineralized freeze-dried bone allografts are suitable for replacing deep-frozen grafts.

Caracterização físico-química de ossos liofilizados de origem bovina e humana

OBJECTIVES: To determine the physical and chemical characteristics and similarities between lyophilized bone from bovine and human sources manufactured in a semi-industrial scale, according to a modified protocol developed by the authors. METHODS: The percentages of fat extract (raw fat), total protein (total nitrogen) and mineral composition (total phosphorus, total P2O5, total calcium, total sodium, ashes and chlorides) was determined on the samples of lyophilized human and bovine bones. RESULTS: The percentage of fat extract and raw protein was of 0.14% and 0.06%; and 27.20% and 27.53%; whereas the mineral composition demonstrated 4.3% and 4.3% of nitrogen; 11.9% and 11.9% of total phosphorus; 27.1% and 27.2% of P2O5; 24.6% and 23.7% of total calcium (Ca/P relation: 2.06 and 1.99); 0.57% and 0.46% of total sodium; 64.8% and 64.3% of ashes; and 1.3% and 1.3% of chlorides, for samples of bovine and human bones, respectively. No statistical significant difference was observed between bovine and human bones after the lyophilization process. CONCLUSION: The assessment of physical and chemical characteristics of bovine and human lyophilized bones has clearly demonstrated that these bones kept virtually all characteristics of a raw bone and keep similarities to human counterparts, yielding an end product with good biocompatibility.

Artroplastia total do quadril de Spotorno

Uma coorte de 48 pacientes (54 quadris) submetidos a artroplastia total primaria de quadril nao-cimentada com protese de Spotorno®. O objetivo do estudo foi avaliar o desfecho clinico-radiologico da protese de Spotorno®,em um periodo de 20 anos (1985 a 2005), com seguimento medio de 17,5 anos (8-20anos). Na avaliacao clinica e funcional foram obtidos 92,7% de bons resultados. Encontrou-se osteopenia em 24 acetabulos (44,4%) e 30 femures (55,6%). O desgaste do polietileno esteve presente em 43 acetabulos (79,6%), com media de dois milimetros (0-5mm). A analise estatistica dos resultados sugeriu que a presenca de osteopenias nao esta relacionada ao desfecho clinico (p=0,75); o desgaste do polietileno, bem como a presenca de osteopenia, foi mais pronunciado nos pacientes abaixo de 55 anos (p<0,05). Concluimos que a utilizacao da protese de Spotorno® nessa coorte apresentou bons resultados, semelhantes aos relatos previos da literatura.

Update on open reduction and internal fixation of unstable pelvic fractures during pregnancy: case reports

This article aims to report four cases of unstable pelvic fractures in pregnant women treated by open reduction and internal fixation. Cases report The study included four cases of pregnant women with unstable pelvic fractures; their outcomes were analyzed and discussed. Data were obtained from two University Hospitals. The mean age of women was 23 years; most (3/4) were primiparous, with a mean pregnancy age of 23 weeks. Two women had Malgaigne-type fractures and the other two had symphyseal disjunction associated with acetabular fractures. All fractures were treated surgically. One foetus was dead on admission to hospital. The other three developed well, along with their mothers. Good evolution was only possible with careful pre-, peri-, and postoperative care for the mother, as well as foetal assessment by a multidisciplinary team. In complex cases such as those presented in the present study, pre-, peri-, and postoperative care are mandatory, as well as the presence of a multidisciplinary team. The mothers life always takes priority in acute clinical pictures, as it offers the best chance of survival to both mother and child.

Acetabular revision in total hip arthroplasty with tantalum augmentation and lyophilized bovine xenograft

Objective To evaluate a mixed technique of acetabular reconstruction, which uses trabecular metal in the form of tantalum augments associated with lyophilized bovine xenograft. Methods Fifteen patients were evaluated prospectively, who underwent acetabular reconstruction with impacted lyophilized bovine xenograft associated with the use of tantalum augments. The main outcome was the failure of the tantalum–bone interface. Results The population had a mean age of 58.33 years ± 14.27; the majority was female, 80%. Of the total subjects, 66.7% were operated for failure in primary arthroplasty. The mean follow-up time was 45.2 months ± 11.39. The failure rate of the method in the period and population studied was 6.7%. Conclusion An extremely high index (93.3%) of success was observed in an average time of 45.2 months of follow-up. Data were comparable to current literature, demonstrating that the technique employed and proposed is adequate for hip reconstruction in young patients.