Bone morphogenetic protein-2 augmentation during revision total hip arthroplasty was associated with radiographic bone consolidation and implant survivorship at 10 years in patients with severe acetabular defects, according to a retrospective cohort study published in Arthroplasty Today.

Researchers evaluated 15 patients (18 hips) who underwent revision total hip arthroplasty with bone morphogenetic protein-2 augmentation between 2011 and 2019 at a single tertiary referral center. Patients had a mean age of 65 years and a mean follow-up of 76 months. Most hips had advanced acetabular defects, including 56% classified as Paprosky 3B, and 61% had pelvic discontinuity. Patients had undergone a mean of nearly two prior surgeries on the affected hip.

The surgical approach used a layered technique combining cancellous allograft bone chips, bone morphogenetic protein-2 collagen sponge, and demineralized bone matrix to address residual acetabular bone loss.

Radiographic and Clinical Outcomes

At final follow-up, 83% of hips demonstrated more than 50% radiographic bone consolidation, and no cases of graft resorption were observed.

Kaplan-Meier analysis showed implant survivorship of:

• 90% at 6 years

• 70% at 10 years

when defined by all-cause reoperation. When acetabular loosening was used as the endpoint, survivorship was 90% at both time points.

Among 13 hips with available patient-reported outcomes, the mean Oxford Hip Score was 35 at a mean of 84 months. All patients were nonambulatory prior to undergoing revision total hip arthroplasty, although preoperative patient-reported outcomes were not collected.

Complications and Reoperations

Postoperative complications occurred in 28% of hips, including:

• Infection in 11%

• Dislocation in 11%

• Sciatic nerve palsy in 6%

Reoperation was required in 11% of hips.

Study Limitations

The researchers noted several limitations:

• Retrospective study design

• Small sample size

• Lack of a control group

• Absence of preoperative patient-reported outcomes

• No cost-effectiveness analysis

• Single-surgeon experience at a tertiary referral center

Conclusion

Bone morphogenetic protein-2 augmentation was associated with radiographic bone consolidation and midterm implant survivorship in revision total hip arthroplasty for severe acetabular defects. However, the researchers emphasized that further studies are needed to clarify the safety and efficacy of this approach.

“We propose a novel method involving the use of BMP-2 augmentation in revision THA, providing osteogenic activity to improve host bone stock and component support in the setting of large acetabular defects,” wrote Nathanael D. Heckmann, MD, of the Keck School of Medicine of the University of Southern California, and colleagues.

Disclosures: Heckmann reported consulting, royalties, stock holdings, and professional society roles; Daniel A. Oakes, MD, reported consulting. The remaining researchers reported no conflicts of interest.

Source: Arthroplasty Today