Document Type : RESEARCH PAPER
Rothman Orthopaedic Institute, Thomas Jefferson University, Philadelphia, PA, USA
Drexel University College of Medicine, Philadelphia, PA, USA
Background: Orthopaedic surgeons rely on visual and tactile cues to guide performance in the operating
room (OR). However, there is very little data on how sound changes during orthopaedic procedures and
how surgeons incorporate audio feedback to guide performance. This study attempts to define meaningful
changes in sound during vital aspects of total hip arthroplasty (THA) within the spectrum of human hearing.
Methods: 84 audio recordings were obtained during primary elective THA procedures during sawing of the
femoral neck, reaming of the acetabulum, acetabular cup impaction, polyethylene liner impaction, femoral
broaching, planning of the femoral calcar and press-fit of a porous-coated stem in 14 patients. We graphed
changes in frequency intensity across the human spectrum of hearing and sampled frequencies showing
differences over time for statistically meaningful changes.
Results: Sawing of the femoral neck, polyethylene impaction, and stem insertion showed significant
temporal increases in overall sound intensity. Calcar planing showed a significant decrease in sound
intensity. Moreover, spectrographic analysis showed that, for each of the critical tasks in THA, there were
characteristic frequencies that showed maximal changes in loudness. These changes were above the 1 dB
change in intensity required for detection by the human ear.
Conclusion: Our results clearly demonstrate reproducible sound changes during total hip arthroplasty that
are detectable by the human ear. Surgeons can incorporate sound as a valuable source of feedback while
performing total hip arthroplasty to guide optimal performance in the OR. These findings can be extrapolated
to other orthopaedic procedures that produce characteristic changes in sound. Moreover, it emphasizes the
importance of limiting ambient noise in the OR that might make sound changes hard to distinguish.
Level of evidence: IV