At present, it is not clear whether performing a hip arthroscopy at the same time as a PAO improves patient outcomes after surgery compared to a PAO alone.

This research project will randomize patients to receive either a PAO alone, or a PAO and a hip arthroscopy at the same time.

Hip dysplasia is a developmental abnormality of the acetabulum (hip socket) that causes abnormal stresses inside the hip joint and leads to painful arthritis at a young age. Many patients develop painful symptoms in their hip before advanced arthritis occurs.

The periacetabular osteotomy (PAO) is a surgical procedure that reorients the acetabulum to reduce the stresses inside the hip joint. The PAO is very effective at improving symptoms and quality of life. However, some patients may have residual symptoms.

Frequently, people with hip dysplasia will have an MRI done before their surgery, which helps to identify other the abnormalities inside their hip joint (e.g., labral tears). These abnormalities inside the joint cannot easily be addressed through PAO alone, however they can be addressed with hip arthroscopy. Hip arthroscopy is a separate minimally invasive surgical procedure that allows the surgeon to access the inside of the hip joint with a small camera and address any abnormalities.

At present, it is not clear whether performing a hip arthroscopy at the same time as a PAO improves patient outcomes after surgery compared to a PAO alone.

This research project will randomize patients to receive either a PAO alone, or a PAO and a hip arthroscopy at the same time. Patients will be followed for 2 years after surgery. Symptomatic differences between the two patient groups will be assessed to determine added benefit of the hip arthroscopy.

Inclusion Criteria:

• Skeletally mature patient undergoing Bernese periacetabular osteotomy for symptomatic acetabular dysplasia/hip instability
• Pre-Operative MRI at 3T and/or gadolinium MR arthrogram
• Age, 16-50 years old
• Patient capable of giving informed consent

Exclusion Criteria:

• Prior hip/pelvis surgery of any kind on the surgical side
• Prior hip arthroplasty surgery on either side
• Radiographic evidence of arthritis (i.e. Tönnis grade =2)
• Known connective tissue disorder (e.g. Ehlers-Danlos Syndrome, etc.)
• Known neuromuscular disorder (e.g. Cerebral Palsy, Spina bifida, etc.)
• Known skeletal dysplasia (e.g. Achondroplasia, Multiple Epiphyseal Dysplasia, etc.)
• Cognitive impairment that prevents accurate completion of patient-reported outcome questionnaires.
• Patient unable/unwilling to complete all required follow-up visits
• Concurrent proximal femoral osteotomy and/or surgical hip dislocation