Hammering sound analysis in Total hip arthroplasty using a novel musical approach

Total hip arthroplasty (THA) is considered one of the most efficient orthopedic operations. Patients with symptomatic hip osteoarthritis, hip osteonecrosis, congenital hip dysplasia, inflammatory arthritis, and femoral head fracture can benefit from THA through pain relief and functional restoration. Various articles have analyzed acoustic features during broaching and stem insertion. Still, they could not provide a conclusive and clinically usable approach to ensure the success of the surgery. In this study, we aimed to investigate sound characteristics with a musical approach using a chromatic tuner. Surgeries were performed by two experienced orthopedic hip fellowship surgeons via the direct anterior and lateral approaches. To capture the sound of the stem insertion, a smartphone was employed. After collecting the data, all the hammer impacts were isolated separately and looped at least 100 times to prepare for the precise determination of the musical note. Finally, a chromatic tuner was employed to obtain musical notes and pitch. Our results indicated that in certain cases, the pattern of sounds identified can be unpredictable, while in other patients, there is minimal change in the hammering sound throughout the procedure. On average, the musical note produced during 60% of the operations is nearly identical to the note B6b (1864 Hz), and in the insertion process, the stem vibrates around this note. Furthermore, it is more probable to identify a trend in the last set of impacts.