Summary
Objectives: To measure one and two year effects of juvenile pubic symphysiodesis (JPS) in puppies
defined as ‘at-risk’ for canine hip dysplasia (CHD) using the following objective
hip conformation criteria: Acetabular angle (AA), dorsal acetabular rim angle (DARA)
and hip laxity (PennHIP© distraction index (DI).
Design: Controlled clinical case study. Animals: Thirty-nine dysplastic puppies (six controls).
Procedures: The dogs were anaesthetised and acetabular angle, DARA, and DI values were obtained
by computed tomography and radiography preoperatively. Electro-cautery fusion of the
pubic symphysis was performed between 12 – 24 weeks of age. The imaging was repeated
at one and two years of age.
Results: Significant hip improvements were seen at the two-year follow-up appointments for:
AA (JPS dogs 31% increase, control 3%), DARA (JPS 38% decrease, control 15%) and DI
(JPS 41% decrease in laxity, controls 20%) for all postoperative versus preoperative
values. Pubic fusion occurred with minor morbidity.
Conclusion: Juvenile pubic symphysiodesis resulted in significant improvements in hip conformation
(AA and DARA), especially in mild to moderately lax hips (DI = 0.40–0.69). Most dogs
with DI ≥0.70 increased in osteoarthritis grade by two years of age.
Clinical relevance: Juvenile pubic symphysiodesis surgery at 12–24 weeks of age significantly improved
hip conformation and decreased laxity in at-risk CHD dogs. Early-age (12 to 16 week)
recognition of hip laxity offered greater JPS benefits than surgery performed at 19-
to 24-weeks-old. Dogs with severe laxity (DI ≥0.70) continued to increase in osteoarthritis.
An early (12–16 weeks) positive laxity test (Ortolani) should alert one to obtain
objective laxity determinations (Penn-HIP© DI).
Keywords
Canine - hip dysplasia - juvenile pubic symphysiodesis