Development of a new palpation method using alternative landmarks for the determination of thoracic transverse processes: An in vitro study

Palpation methods (PMs) have been proposed to guide clinicians in locating the thoracic transverse processes (TTPs). However, no studies have assessed the validity of TTPs palpation or the added value of musculoskeletal ultrasound (MSU). The objectives of the present study were (1) to explore the validity of TTPs location using palpation as commonly performed by clinicians, (2) to develop an accurate and valid PM, and (3) to assess the added value of MSU. A standardized procedure was used on six cadavers. It consisted in the insertion of markers through the T3, T5, T6 and T8 TTPs and spinous processes, which were identified using palpation and MSU. First, a fresh cadaver was used to explore the validity of the common palpation method. Since poor validity was observed, one intermediate and a final PMs were tested on a total of five Thiel-embalmed specimens. A descriptive analysis was performed and agreement between MSU and the final PM was determined. The final PM led to the proper determination of all TTPs on three specimens with a mean error of 4 ± 1.8 mm in relation to the TTPs center. The coefficient of variations and root mean square errors were ≤0.15 and 0.21 mm, respectively. Bland-Altman plot showed no differences between palpation and MSU. In conclusion, this study reports the validity of a new PM using multiple landmarks to guide TTPs determination and for which MSU does not seem to add value in accuracy. These results may have important clinical implications for clinicians using palpation.