Acetabular development after bipolar hemiarthroplasty for osteosarcoma in children

Area of Science:

• Orthopedic surgery
• Pediatric oncology
• Radiology

Background:

• Osteosarcoma resection in children often requires proximal femur reconstruction.
• Hemiarthroplasty is a common reconstructive option for proximal femur defects.
• Open triradiate cartilage indicates skeletal immaturity, posing unique challenges for acetabular development post-surgery.

Purpose of the Study:

• To evaluate acetabular development changes after proximal femur hemiarthroplasty in skeletally immature patients.
• To identify radiographic parameters indicative of altered acetabular growth following this procedure.

Main Methods:

• Retrospective analysis of eight patients with open triradiate cartilage undergoing proximal femur resection for osteosarcoma and hemiarthroplasty.
• Serial radiograph analysis including centre-edge angle, teardrop-to-medial prosthesis distance, superior joint space, and lateral translation.
• Assessment of arthritic changes and prosthetic head migration.

Main Results:

• All patients exhibited progressive superior and lateral migration of the prosthetic femoral head.
• Acetabular deepening and enlargement were arrested following hemiarthroplasty in the immature acetabulum.
• The extent of femoral head migration correlated with age at diagnosis and follow-up duration.

Conclusions:

• Proximal femur hemiarthroplasty in skeletally immature patients with open triradiate cartilage can impede normal acetabular development.
• Surgeons should consider the long-term implications for acetabular morphology when performing hemiarthroplasty in this patient population.
• Further research is needed to optimize reconstructive strategies and mitigate adverse acetabular remodeling.