Comparative studies of radiological and arthroscopic findings of a dog’s hip joint

In the context of the study for Winkler’s PhD thesis “the aim was to examine the arthroscopy of a dog’s hip joint and to judge the sensitivity of arthroscopy in comparison to radiological examination”.

32 hip joints of 25 dogs were examined at the Small Animal Clinic of the School of Veterinary Medicine Hannover between March 2006 and August 2007. 16 of these dogs came to the clinic for check-ups and in some cases preventive operations on the hip joint, while 9 were cadaver animals. “The study showed that the correct positioning of the limb was crucial for the success of the arthroscopy. For that the limb had to be placed parallel to the surgical table in a slight adducted position to maximize the width of the joint space” and thus allow “a gentle insertion of the arthroscope.

With the exception of the medioventral portion of the femoral head all joint structures could be seen and observed in detail during the arthroscopy. A craniolateral port with a 2.7 mm arthroscope was chosen”, and the arthroscope was inserted into the joint approximately 2 cm cranially and 2 cm proximally in relation to the greater trochanter. In order to judge the sensitivity of arthroscopy in comparison to radiological examination, “all dogs were x-rayed in three different projections; the radiographic and arthroscopic findings were compared. During the radiographic and arthroscopic examination, the cranial and caudal portion of the acetabulum” were evaluated “as well as the cranial and caudal portion of the femoral head”.

During the arthroscopic examination 75% (n = 24) of the patients showed a pathological change “of the synovial fluid in form of abnormalities in colour and shape of the villi. Tears as well as fraying and even avulsion of the labrum were observed in 78.1% (n = 25) in the acetabular labrum. The ligament of the femoral head only showed” a physiological picture arthroscopically in 15.6% (n = 5). “Between 45.5% and 53.8% of the radiographic hip joints with no diagnostic findings showed arthroscopically pathological” changes of the joint.

All joints which showed full-thickness cartilage erosion arthroscopically also showed changes radiologically. However, in low-grade to medium-grade arthroscopic changes, radiologically deviant findings were only apparent in 63.2% to 70.6% of the patients.

Results show that arthroscopy of the dog’s hip joint is a sensitive method for detecting pathological changes in the joint. Nevertheless, further studies with more patients are necessary to investigate the number of complications in greater depth as well as to determine long-term effects with regard to the development of coxarthrosis. As a diagnostic treatment, arthroscopy of the hip joint is superior to radiological examination, if a detailed look at, and evaluation of, internal joint structures with minimal invasion is important.
 

Claudia Winkler: Vergleichende Untersuchungen von röntgenologischen sowie arthroskopischen Befunden am Hüftgelenk des Hundes. Dissertation an der Klinik für Kleintiere der Tierärztlichen Hochschule Hannover, 2008, https://www.deutsche-digitale-bibliothek.de/item/LPIUAE7QL72RCU4IR4XZ7NE7WMSOIOXD .