Canine hip dysplasia treated by juvenile pubic symphysiodesis

Abstract

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). Controlled clinical case study. Thirty-nine dysplastic puppies (six controls). 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. 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. 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. 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 (PennHIP© DI).