Modified cementless total coxofemoral prosthesis: development, implantation and clinical evaluation / Prótese coxofemoral não cimentada: desenvolvimento, implantação e avaliação clínica

The aim of this study was to modify canine coxofemoral prostheses and the clinical evaluation of the implantation. Fifteen canine hips and femora of cadavers were used in order to study the surface points of modification in prostheses and develop a perforation guide. Femoral stems and acetabular components were perforated and coated with biphasic calcium phosphate layer. Twelve young adult male mongrel dogs were implanted with coxofemoral prostheses. Six were operated upon and implanted with cemented canine modular hip prostheses, establishing the control group. The remaining six were implanted with a novel design of cementless porous tricalcic phosphate-hydroxyapatite coated hip prostheses. Clinical and orthopedic performance, complications, and thigh muscular hypotrophy were assessed up to the 120th post-operatory day. After 120 days, animals with cementless prostheses had similar clinical and orthopedic performance compared to the cemented group despite the increased pain thigh hypotrophy. Animals that underwent cementless hip prosthesis evidenced more pain, compared to animals with cemented hip prosthesis that required longer recuperation time. No luxations, two fractures and two isquiatic neurapraxies were identified in the course of the study. Using both the cemented and the bioactive coated cementless model were suitable to dogs, showing clinical satisfactory results. Osseointegration and biological fixation were observed in the animals with the modified cementless hip prosthesis.

O objetivo deste estudo foi modificar a prótese coxofemoral canina cimentada e avaliar os efeitos clínicos. Foram utilizadas 15 pelves e 15 fêmures de cadáveres de cães para modificações da haste, do componente acetabular e para a confecção de guia de perfuração. As hastes e componentes acetabulares foram perfurados e revestidos com uma camada de fosfato de cálcio bifásico. Doze cães machos, adultos jovens, sem raça definida, foram submetidos à cirurgia para o implante de prótese coxofemoral total. Seis cães receberam prótese modular cimentada, grupo controle, e seis, a prótese modificada não cimentada com revestimento de fosfato de cálcio bifásico. Foram avaliados a técnica de implantação, o desempenho clínico, o grau de hipotrofia muscular da coxa e as complicações durante 120 dias. Os animais com prótese não cimentada mostraram desempenho clínico similar aos animais com a prótese cimentada, porém mostraram maior hipotrofia muscular decorrente de dor e maior tempo de recuperação. Não foram observadas luxações. No entanto, duas fraturas e dois casos de neurapraxia isquiádica foram observados. A utilização de ambas as próteses coxofemorais, cimentada e não cimentada, com recobrimento bioativo são eficientes no cão, com resultados clínicos satisfatórios, mas a osteointegração e fixação biológica ocorreram na prótese com recobrimento de fosfato de cálcio bifásico, objetivo do tratamento que previne afrouxamento futuro.

Vídeo-artroscopia da articulação fêmoro-tíbio-patelar em cães após secção do ligamento cruzado cranial guiada por artroscopia / Videoarthroscopy of the stifle joint in dogs after cranial cruciate ligament rupture guided by arthroscopy

Avaliaram-se e classificaram-se por meio da vídeo-artroscopia as alterações da articulação fêmoro-tíbio-patelar (FTP), 21 dias após secção experimental do ligamento cruzado cranial (LCCr) em cães, tendo como referência os parâmetros encontrados no exame artroscópico imediatamente anterior à secção. Ao exame artroscópico, foi possível visibilizar os cotos remanescentes do LCCr e as alterações articulares, como aumento da vascularização, aumento das vilosidades na membrana sinovial, bem como fibrilação e osteófitos, principalmente nas bordas trocleares do fêmur. Os resultados sugerem que a artroscopia é um método preciso de avaliação macroscópica dos tecidos articulares moles e duros.

By the use of videoarthroscopy, the changes of the stifle joint after experimental rupture of cranial cruciate ligament (CCL) in dogs were evaluated and classified, based on the parameters found at the arthroscopic examination right before the rupture. By the arthroscopic examination, it was possible to visualize the remainings of the CCL and joint changes such as increase of the vascularity and synovial proliferation increase in the synovial membranes, as well as fibrillation and irregularities on the joint surfaces and osteophyte formation, mainly on the trochlear ridges. The results suggest that arthroscopy is a precise method for macroscopic evaluation of the smooth and bone joint tissues.

Pós-operatório tardio da substituição do ligamento cruzado cranial no cão / Late postoperative of cranial cruciate ligament replacement in dog

Realizaram-se avaliações radiográfica e clínica pós-cirúrgica tardia da substituição do ligamento cruzado cranial (LCCr) por fáscia lata autógena em casos de ruptura clínica em 14 cães, de ambos os sexos, com massa corporal média de 28,6kg e idade média de 68 meses. As articulações tratadas constituíram o grupo tratado e as contralaterais o grupo-controle, totalizando 28 articulações estudadas. O tempo médio entre o aparecimento dos sintomas e a cirurgia foi de cinco meses e 15 dias e o decorrido entre a cirurgia e a avaliação pós-cirúrgica, 14 meses. Deambulação normal foi vista em 57,1 por cento e claudicação discreta em 32,9 por cento dos casos tratados. Nestes foram observados crepitação, dor, redução da amplitude de movimento articular e do diâmetro da coxa. Ausência de claudicação foi vista em 92,8 por cento dos casos-controle. Doença articular degenerativa foi verificada radiograficamente nos dois grupos. A técnica empregada para substituição do LCCr foi efetiva clinicamente. Os resultados radiográficos, as vezes, mostravam-se diferente dos clínicos. O resultado foi melhor nos pacientes cuja cirurgia foi realizada após curto período do inicio dos sintomas e o intervalo entre a lesão e o tratamento foi o fator que mais influenciou na recuperação pós-operatória

After the replacement of the cranial cruciate ligament (CrCL) with an autogenous fascia lata graft, radiographic and clinic post-surgical evaluation were performed. Fourteen male and female dogs averaging 68 month-old and 28.6kg body weight with unilateral rupture of CrCL were selected. Twenty-eight joints were studied. The treated joints consisted of the treated and non-treated animals. The mean time from the initial onset of the symptoms to the surgery was five months and 15 days and the mean interval between the surgery and the follow-up examination was 14 months. No lameness was observed in 57.1 percent of the treated dogs and mild lameness in 42.9 percent of them. In this group, articular crepitus, pain, reduced articular motion amplitude and muscular atrophy were observed. No lameness was observed in 98.2 percent of the non-treated dogs. These joints showed mild arthrosis. Degenerative joint disease was observed in both groups. The surgical technique was efficient, the dogs showed clinical improvement after surgery, regardless of radiographic signs. The results were better in the dogs submitted to surgery soon after the onset of the symptoms. The interval between the injury and the treatment was the most important factor involved in the recovering after surgery

Avaliação pós-operatória da fixação esquelética externa em 29 cães: estudo retrospectivo / Post surgical evaluation of external skeletal fixation in 29 dogs: a retrospective study

In this retrospective study 29 dogs of both sexes of several breeds, were evaluated. Complications of external skeletal fixation were common. The most frequent post-surgical complications were chronic pin track drainage or pin loosing (11; 37.9 percent), followed by dry crust at the skin-to-pin interface (5; 17.1 percent). In five cases (17.1 percent) occurred the healing of the fracture without complications. In three dogs (10.4 percent) occurred nonunion and it was used another fixation method. It was observed individual cases of poor limb use (3.5 percent) or breakage of the pin (3.5 percent) or of the acrylic column (3.5 percent). Pin track drainage or loosing was related to the owners care. The most did not come back to the hospital as was demanded or did not follow the instructions to inspect the apparatus daily. This behaviour contributed to increase the rate of post-surgical complications. The external fixation has the advantage to be less invasive and can be used to treat closed and open fractures, limb deformities, nonunion and infected fractures.