Resolving the Bhandari Paradox

The preferred treatment for displaced geriatric femoral neck fractures (DGFNF) is hemiarthroplasty or total hip arthroplasty (THA). In brief, hemiarthroplasty is a faster operation with a fewer dislocations; THA offers better functional outcomes and greater longevity.

Bhandari has shown that the attributes of THA are far more valued by patients, yet only a scant minority of DGFNFs are treated with THA. We term that the Bhandari paradox – the overwhelming prevalence of an operation with underwhelming appeal. This finding is echoed in studies from England, showing that only 1/3rd of patients indicated for THA by the NICE criteria received it.

We suggest four possible resolutions to this paradox. First, patients may anticipate a short life expectancy, and thus infrequent dislocations are worth more than greater prosthetic longevity. It is also possible that patients have a high “discount rate”, attributing less value to gains in the distant future. It is also possible that patients or their surgeons recognize external costs associated with THA (including morbidity and mortality, surgeons’ lack of comfort performing THA, the delay imposed by waiting for surgeons comfortable with THA, or monetary cost, etc.) Last, it is possible that patients’ preferences are applied incorrectly.

We suggest that the resolution of the Bhandari paradox is that the THA vs hemi decision “exceeds the capacity of the unaided human mind.” (Eddy) Accordingly, we created a decision aid that solves a modified Markov process expected utility calculation, based on life expectancy, relative functional values, the costs of dislocation and prosthetic failure and longevity and dislocation risks, with discounting for deferred benefits.

We use this decision aid is to identify the loci within the decision space where hemiarthroplasty is preferable, and demonstrate that short life-expectancy and discounted values for late function combined to make hemiarthroplasty a reasonable choice in many situations.