Evaluation of a joint distractor to facilitate arthroscopy of the tibio-tarsal joint in dogs

Evaluation of a self-retaining distractor for hip joint arthroscopy in toy breed dogs

Background

Hip arthroscopy has become a viable option over the last few years for small animal orthopedic diseases, including hip dysplasia, osteoarthritis, and joint evaluation. However, the narrow joint spaces make it difficult to manipulate the instrument, and depth of tissues make it difficult to distract the joint space. In addition, it is very difficult to maintain consistent distraction over time with a manual distraction due to hand fatigue. To overcome these difficulties, distractors are used in human medicine to improve safety and accuracy of arthroscopy. Therefore, in this study, distractor devices were applied to hip joints in small toy breed dogs to evaluate their technical efficacy. Potential iatrogenic neurovascular and articular damage were also evaluated by comparing two techniques for performing hip joint arthroscopy: the self-retaining distractor and external manipulation.

Results

The mean ± SD of the joint distraction distance was 8.88 ± 3.54 mm in the self-retaining distraction group and 2.37 ± 0.82 mm in the manual traction group. As the joint space increased, surgeons could more easily place an arthroscopy portal and more comfortably manipulate the instrument with a distractor device. Furthermore, the acetabular cartilage damage (p = 0.004) was significantly greater in the external manipulation group, but articular damage to the femoral head (p = 0.940) was similar in both groups.

Conclusion

The results of this study revealed that use of a distractor device can be a viable option for performing hip arthroscopy in small animals. The device significantly improved the surgeon’s performance without surgical assistance, and it reduced iatrogenic cartilage damage compared with manual traction. Further study is needed to quantify neurapraxia associated with distractor placement.

Facilitation of arthroscopic visualization and treatment of meniscal tears using a stifle joint distractor in the dog

Background

Stifle arthroscopy has been described to have high sensitivity and specificity in the evaluation of menisci in dogs, particularly for the medial meniscus. However, the visualization of menisci can be difficult. The use of femoral distractors in human medicine has been described to simplify demanding surgical procedures, such as meniscus transplantation. In veterinary medicine, stifle distraction has been reported to facilitate access to the joint and visualization of intra-articular structures, but there are no studies reporting the use of a stifle distraction technique while performing challenging surgical procedures, such as meniscal suture, in clinical patients.

The objective of this study was to evaluate the feasibility, effectiveness and safety of stifle distraction to achieve consistent visualization of menisci and to facilitate performing arthroscopic procedures in clinical patients with stifle disease. Initial arthroscopic evaluation of the stifle joint was performed without distraction in the study population consisting of 13 dogs with naturally occurring stifle disease. The criteria for inclusion was prospectively set as the observation of a frank disease or anomaly of the menisci that could not be further treated or clarified without the risk of damaging the joint cartilage due to the requested manoeuvres. After the first examination, distraction was applied in order to complete the assessment of menisci. After achieving an accurate diagnosis, partial meniscectomy or meniscal repair was performed as needed while maintaining the distraction.

Results

Complete visualization and assessment of menisci were achieved thanks to the use of distraction. This manoeuvre facilitated access to the required area of the involved meniscus, and meniscal treatment could be successfully performed without damaging the articular cartilage. During the follow-up period, no postoperative complication related to the distraction or to the arthroscopic procedure was observed.

Conclusions

Stifle joint distraction during arthroscopy in dogs improves visualization of both menisci, and particularly the caudal horn of the medial meniscus. Despite being a subjective assessment, it is the authors’ opinion that this procedure also increases the ease of performing challenging procedures like meniscal suture, as it enlarges the space available to reach the correct working angulations.

Evaluation of a distractor to increase joint space of the stifle joint in dogs: a cadaveric study

Objective: To evaluate the technical feasibility and efficacy of a joint distraction technique to increase the stifle joint space and assess potential soft tissue damage due to the distraction.

Methods: Twenty stifle joints of twelve canine cadavers without evidence of disease were radiographically evaluated by medio-lateral, cranio-caudal and varus-valgus stressed projections. Joint distraction was applied with loads from 40 N up to 200 N, and the joint space achieved was measured on radiographic images. Distraction plus distension with saline was subsequently applied and measured. Varus-valgus stressed projections were repeated after distraction to evaluate a potential increase in joint laxity.

Results: Distraction produced a significant increase of the joint space for most of the evaluated loads. Distraction plus distension produced a significant increase for most of the loads compared to the distraction alone. No ensuing joint laxity could be inferred from the post-distraction radiographic evaluation.

Clinical significance: Stifle distraction produces an increase of the joint space, which is wider when intra-articular saline is injected. This may be potentially useful for improving joint structure visualization and facilitating arthroscopic procedures, thus reducing the potential for iatrogenic damage to intra articular structures. No soft tissue damage could be inferred by radiographic pre- and post-procedure comparison. Further clinical studies are required to evaluate potential neurovascular complications.

Desenvolvimento e avaliação de equipamento de tração, para redução de fraturas de ossos longos de cães

RESUMO Fraturas costumam ocorrer com encavalgamento das extremidades ósseas, dificultando, assim, sua redução. Esta pesquisa teve como objetivo desenvolver um equipamento de tração esquelética a ser utilizado em caninos acometidos de fraturas de ossos longos. Foram utilizados 21 cães de raças variadas, pesando entre dois e 27kg, com idade entre dois meses e 11 anos, com fraturas diafisárias ou metafisárias ocorridas entre três e 24 dias. Enquanto a fixação do corpo do paciente à mesa foi efetuada com cintas de náilon, a força de tração aplicada ao longo do eixo ósseo do membro fraturado foi realizada mediante cintas de náilon ou pinos transfixados e estribos (sendo os pinos implantados na epífise distal do osso fraturado), com a força de tração medida por um dinamômetro, não sendo aplicada carga maior que 25kg. Em todos os casos, a força de tração iniciava com o valor de cinco quilogramas, exceto em animais com peso inferior a esta, a qual começava com carga equivalente a esse peso; e em todos, se necessário, era aumentada a cada cinco minutos para se manter tração igual ao peso ou aos valores que oscilavam do seu peso até cinco quilogramas, dependendo do tamanho do animal, até se atingir a tração necessária para se proceder à redução. Para essa progressão de distensão, o equipamento possuía haste rosqueada de 25mm de diâmetro, uma porca com sistema timão e cilindro deslizante por fora da haste, este conectado ao animal por uma corrente, e o dinamômetro. Todos os animais tiveram as fraturas reduzidas sem haver perda óssea, o que evidencia que o aparelho se mostrou eficiente tanto na redução como na manutenção da redução da fratura, e eles não apresentaram, no pós-operatório, sinais de prejuízos neurológicos, vasculares, cutâneos e articulares. O distensor ósseo aqui desenvolvido tem como características: ser de simples confecção, ter baixo custo, não gerar danos ao paciente e facilitar a redução dos fragmentos tanto em fraturas recentes quanto em antigas.

Evaluation of a joint distractor to facilitate arthroscopy of the hip joint in dogs

OBJECTIVE

To evaluate the technical feasibility and efficacy of a hip joint distraction technique, any potential ligamentous damage linked to the procedure, and the effect of joint venting on the maximum distraction achieved.

METHODS

Twenty hip joints from 11 canine cadavers were evaluated radiographically by standard and stressed projections. Joint distraction was applied with loads from 40 up to 200 N, in 40 N increments, and fluoroscopic images were obtained at each load. At 200 N, a needle was inserted into the joint to achieve a venting effect, and the space was measured again. Standard and stressed radiographs were performed to evaluate potential laxity changes.

RESULTS

Distraction caused a significant increase in joint space at each load of distraction, although there were some variations. Joint venting produced a significant increase in joint space. A statistically significant difference in joint laxity evaluated radiographically before and after the procedure was recorded.

CLINICAL SIGNIFICANCE

Use of the distraction apparatus resulted in an increase in joint space. This could be useful for clinical situations where a larger joint space is required such as for arthroscopic procedures. However, loads in excess of 200 N may induce significant increases in joint laxity.