Triple pelvic osteotomy (TPO) is frequently used in immature dogs for treatment of hip dysplasia. The acetabular segment is rotated an appropriate amount after osteotomy of the pubis, ischium and ilium. The acetabulum is stabilized with a contoured plate and screws placed over the ilial osteotomy site. The positional change of the acetabulum increases the stability and decreases the chance of subluxation in dogs that meet the criteria for the procedure. The goal of the procedure is to decrease the chance of developing progressive osteoarthritis and to maintain limb function.

Surgical Technique

A standard approach to the pubis, ischium and ilium is made as described by Slocum. A pubic osteotomy is performed adjacent to the iliopectineal eminence and a small portion of pubis is removed. The ischial osteotomy is made at the lateral extent of the obturator foramen and is stabilized with a 1.0 or 1.25 mm orthopedic wire at the surgeon's discretion. The ilial osteotomy is made just caudal to the caudal extent of the sacrum. Care to avoid the sciatic nerve is taken. The acetabular segment is rotated laterally to the proper position and stabilized with a bone plate and screws of the surgeon's choice.

Arthroscopic Evaluation

Hip arthroscopy can be readily performed with minimal difficulty. Hip arthroscopy allows thorough visual assessment of the normal and pathologic intraarticular anatomy. The prime indication for hip arthroscopy is assessment of juvenile canine patients for triple pelvic osteotomy. There is a significant degree of cartilage, femoral capital ligament and joint capsule pathology with no radiographic evidence of osteoarthritis in some juvenile dogs. A poor correlation between radiographic and arthroscopic findings, shown by Holsworth et al., makes accurate assessment of suitable surgical candidates by radiography alone difficult.

A recent study by Bevin and Beale documented and described the intra-articular pathology of the dysplastic hip joint prior to and at long term following triple pelvic osteotomy. The goal of the study was to evaluate the effect of the TPO on the progression of hip osteoarthritis (OA) and to identify any variables that may predict the outcome of the procedure. Pathologic changes of both the acetabular labrum and articular cartilage were common arthroscopic findings. The primary change seen in the acetabular labrum was tearing at its articular or free margin. Eleven of the twenty hips (55%) had labral pathology preoperatively. Seven of these (35%) hips had an appreciable progression of labral pathology, and seventeen of the hips (85%) had some degree of labral tearing at the final evaluation. Cartilage lesions were graded using a modified Outerbridge system and their location was documented. Nine of the nineteen treated hips (47%) had progression of cartilage pathology. Eight of these dogs had minimal to mild changes, and one dog had moderate to severe progression of pathology. Ten hips had no change in cartilage pathology with nine of these hips having no pre-operative cartilage changes. There was a statistically significant correlation between pre-operative arthroscopic findings and post-operative radiographic evidence of OA. This suggests that pre-operative arthroscopic findings are a better predictor of outcome than radiographic evidence of OA. These findings are supported by a previous study presented in 2002 by Holsworth et al., in which there was a poor correlation between preoperative radiographic and arthroscopic findings. The results of this study suggest that the TPO procedure does not completely stop the progression of OA, however, clinical use of the affected limbs was good at the time of follow-up despite presence of OA.

	Figure 1. Lateral scope portal
	Figure 2. Round ligament as viewed arthroscopically
	Figure 3. Normal labrum
	Figure 4. Labral tear
	Figure 5. Normal acetabular cartilage
	Figure 6. Grade 4 cartilage erosion of femoral head

Radiographic evaluation was not a reliable indicator of pathologic changes following TPO

Juvenile Pubis Symphysiodesis (JPS)

JPS is a technique used to influence pubis growth and acetabular position in puppies having early hip dysplasia. Experimental studies by Dueland and Patricelli showed improved hip conformation and decreased chance of developing osteoarthritis following this procedure. The procedure must be performed between 3 and 5 months of age. Early diagnosis of hip laxity is best performed using the PennHIP technique. The pubic symphysis is closed prematurely by application of heat using an electrosurgical probe. Clinical success using this technique has been reported, however, most patients having hip laxity and dysplasia are diagnosed too late to take advantage of this procedure.