Can Adding BMP2 Improve Outcomes in Patients Undergoing the SUPERhip Procedure?

Area of Science:

• Orthopedic Surgery
• Pediatric Orthopedics
• Limb Reconstruction

Background:

• Congenital femoral deficiency (CFD) Paley type 1b presents with severe upper femur deformity and hip contractures.
• The Systematic Utilitarian Procedure for Extremity Reconstruction of the hip (SUPERhip) was developed to correct CFD.
• Early SUPERhip procedures using non-fixed angle devices had high rates of delayed ossification and varus deformity.

Purpose of the Study:

• To evaluate if fixed angle internal fixation and bone morphogenetic protein 2 (BMP2) reduce late complications in SUPERhip procedures for CFD Paley type 1b.
• To assess the efficacy of specific modifications in preventing recurrent varus and delayed ossification.

Main Methods:

• Retrospective review of 106 SUPERhip procedures (72 primary, 34 revisions) for Paley type 1b CFD (1997-2012).
• Comparison of outcomes between procedures with and without BMP2, and with fixed angle versus non-fixed angle internal fixation.
• Analysis of complication rates including recurrent varus and delayed femoral neck ossification.

Main Results:

• Fixed angle devices significantly reduced recurrent varus compared to non-fixed angle devices.
• BMP2 insertion significantly decreased persistent delayed ossification of the femoral neck.
• The combination of fixed angle fixation and BMP2 demonstrated the lowest incidence of recurrent coxa vara and delayed ossification.

Conclusions:

• The SUPERhip procedure effectively addresses CFD Paley type 1b pathoanatomy.
• Fixed angle internal fixation is crucial for preventing recurrent coxa vara.
• BMP2 application is essential for inducing femoral neck ossification and preventing delayed ossification.