# Ultrasonographic Ventral Hip Joint Approach and Relationship with Joint Laxity in Estrela Mountain Dogs

## TL;DR

This study shows that ultrasound can detect early signs of hip dysplasia in dogs before X-rays can, potentially improving early diagnosis and treatment.

## Contribution

The study introduces a ventral ultrasonographic approach to detect early hip joint changes in Estrela Mountain dogs, correlated with joint laxity.

## Key findings

- Ultrasound measurements of synovial fluid and capsular fold thickness correlated strongly with hip joint laxity.
- The ventral hip ultrasound approach shows promise for early detection of hip dysplasia in young dogs.
- Statistically significant correlations were found between ultrasound parameters and radiographic distraction index.

## Abstract

Hip dysplasia (HD) is an orthopedic disease that affects large-sized dogs, causing pain and damage to the hip joint. Diagnosing HD is challenging because X-rays often detect this condition in late stages. Our study explored the use of ultrasound, a safer and non-invasive diagnostic tool, to identify early signs of HD progression in Estrela Mountain dogs. Using a ventral approach to the hip joint, we evaluated a series of measurements and correlated them with the distraction index, an X-ray measurement that evaluates joint looseness. We found a strong correlation between these measurements, showing that the ultrasound can detect early hip changes, associated with late HD development. Our findings can help veterinarians identify hip dysplasia earlier, leading to better treatment options and an improved quality of life in dogs.

Hip dysplasia (HD) is a prevalent disease in medium- to large-breed dogs, characterized by joint laxity and degenerative joint changes. The early diagnosis of HD poses significant challenges, as radiographic imaging often identifies the disease only in advanced stages. Conversely, ultrasonography, a non-invasive and cost-effective imaging modality, offers the potential for earlier detection by evaluating the surrounding soft tissues and synovial changes. This study aimed to assess the relationship between the ventral hip ultrasonographic findings, and hip joint laxity evaluated through stress radiographs on 22 young Estrela Mountain dogs (n = 44 hips) aged 4 to 8 months. Key ultrasound measurements included synovial fluid in the cranial femoral neck recess (CFNR) and capsular-synovial fold thickness (CFT). Radiographic laxity was estimated by measuring the distraction index (DI). The median (quartile 25–75%) of the CFNR area, CFT, and DI were 44.00 (27.00–52.25) mm2, 3.10 (2.68–3.55) mm, and 0.38 (0.34–0.40), respectively. The Spearman correlation coefficient was statistically significant between all of these variables (p < 0.05). The ventral ultrasonographic approach to the hip joint revealed potential, considering the early diagnosis of HD in dogs, by showing relationships between changes in periarticular soft tissues and joint laxity. Further studies are needed to associate ultrasonographic findings with radiographic signs of HD and related clinical signs in dogs.