Anteverting Periacetabular Osteotomy for Acetabular Retroversion.

INTRODUCTION

The periacetabular osteotomy procedure reorients a retroverted acetabulum into a more anatomically appropriate position.

STEP 1 EVALUATION OF ACETABULAR RETROVERSION: Evaluate acetabular retroversion on the basis of a combination of radiographic signs.

STEP 2 PATIENT POSITIONING AND SKIN INCISION: After draping and sterile preparation with the patient in a supine position, make an incision following the skin lines of the inguinal fold.

STEP 3 EXPOSURE OF THE DEEP MUSCLE LAYERS AND THE PELVIC BRIM: Detach the abdominal wall muscles from the anterior iliac crest and detach the sartorius muscle and the inguinal ligament to expose the iliac fossa and the pelvic brim.

STEP 4 SURGICAL DISSECTION FOR PREPARATION OF THE ISCHIAL OSTEOTOMY: Detach the iliocapsularis muscle and mobilize it medially to allow access to the infra-articular space and palpation of the ischial bone.

STEP 5 INCOMPLETE PARTIAL ISCHIAL OSTEOTOMY: Introduce a curved chisel with a crescent-shaped tip into the infra-articular space in order to perform the osteotomy of the ischial bone.

STEP 6 OSTEOTOMY OF THE SUPERIOR PUBIC RAMUS: Place subperiosteal blunt retractors around the superior pubic ramus to ensure safe and complete pubic bone osteotomy.

STEP 7 SUPRA-ACETABULAR AND RETROACETABULAR OSTEOTOMY: Start the supra-acetabular horizontal osteotomy at the anterior superior iliac spine and end it 2 cm lateral to the pelvic brim, where the osteotomy is angled 100° distally.

STEP 8 MOBILIZATION OF THE ACETABULAR FRAGMENT: With the help of a spreader and a 4.5-mm threaded Schanz pin, free and mobilize the acetabular fragment.

STEP 9 REORIENTATION OF THE ACETABULAR FRAGMENT: Perform internal rotation of the acetabular fragment with the help of the threaded Schanz pin.

STEP 10 IMPROVEMENT OF ANTERIOR HEAD-NECK OFFSET FEMORAL NECK OSTEOPLASTY: Anterior capsulotomy and improvement of anterior head-neck offset is recommended when internal rotation is <30°.

STEP 11 ANTEROPOSTERIOR PELVIC RADIOGRAPH FOLLOWING PERIACETABULAR OSTEOTOMY: Ideally, a postoperative radiograph should show negative crossover and posterior wall signs while the ischial spine sign typically remains positive.

RESULTS

The long-term results of the periacetabular osteotomy in a series of twenty-two patients (twenty-nine hips) with symptomatic acetabular retroversion were evaluated after a mean duration of follow-up of eleven years (range, nine to twelve years).IndicationsContraindicationsPitfalls & Challenges.