Treatment of Vancouver Type B Periprosthetic Femoral Fractures Using Cortical Strut Allografts.

INTRODUCTION:
The optimal surgical treatment for Vancouver B2 and B3 fractures has not been determined, and bone defects and delays in fracture healing significantly affect treatment outcomes. Some authors have argued that when a serious bone defect is present, the use of cortical strut allografts for the treatment of type B2 and B3 periprosthetic femoral fractures (PFFs) after hip joint replacement may be beneficial. This study aimed to determine the usefulness of cortical strut allografts based on mid-to long-term clinical radiologic results after surgical treatment of Vancouver B-type PFFs.

METHODS:
We retrospectively reviewed the outcomes of 48 patients with postoperative PFFs. The mean duration of follow-up was 6.7 years. The 22 patients were treated with cortical strut allograft. Each case was characterized and described in detail, including the length of allograft and the union period, and possible correlations between allograft length and strut-to-host bone union were analyzed. Clinical evaluations included Parker mobility and Harris hip scores. At the final follow-up, we assessed the radiological results using the Beals and Tower's criteria, stem subsidence, and fracture union time.

RESULTS:
All 48 fractures united at an average of 21.5 weeks, and strut-to-host bone union was typically observed within 32 months. No positive correlation was identified between the allograft length and incorporation period. There was one deep infection and four cases of dislocation, but there was no fracture or malunion of the cortical strut allografts. No evidence of femoral loosening was observed in any of the patients.

CONCLUSION:
Cortical strut allografts used to treat type B PFFs showed high rates of bone union and survival. In mid-to long-term follow-up, the cortical strut allograft length did not affect to incorporation time. The author concluded that cortical strut allografts are useful treatment for PFFs regardless subtype classification of the Vancouver type B.