Pre- and Post-Operative Pain Intensity and Physical Activity Levels in Individuals with Acetabular Dysplasia Undergoing Periacetabular Osteotomy: A Prospective Cohort Study.

Background: Acetabular dysplasia (AD) causes pain, limited function, and development of early hip osteoarthritis. Periacetabular osteotomy (PAO) is a surgical treatment for AD that aims to reposition the acetabulum to reduce pain and improve function.

Purpose: To examine pain recovery and physical activity (PA) before and during the six months after PAO.

Study design: Case series, prospective.

Methods: Individuals with AD scheduled for PAO were enrolled. Pain intensity was evaluated before PAO and at one week and one, three, and six months following PAO. PA levels was evaluated before and six months following PAO using accelerometers (time spent in sedentary behavior, light PA, moderate-to-vigorous PA [MVPA], and daily steps) and the International Physical Activity Questionnaire (IPAQ; time spent in walking and in MVPA). Pain improvements was examined over time following PAO using a repeated-measures one-way ANOVA as well as improvements in PA levels before and six months after PAO using paired-sample t tests. In addition, time spent in MVPA was qualitatively summarized at each time point (before and six months after PAO) measured by both the accelerometers and IPAQ.

Results: Out of 49 screened participants, 28 were enrolled, and 23 individuals (22 females; age=23.1±7.9 years) completed both study visits. Compared to pre-PAO pain, participants reported significant improvements in pain at one month and onward following PAO (p\<0.011). However, PA levels at six months following PAO did not differ from pre-PAO PA levels (p>0.05). Qualitatively, participants reported spending more time in MVPA recorded by the IPAQ (pre-PAO=73.3±150.2 mins/day; six-months after PAO=121.2±192.2 mins/day), compared with MVPA recorded by accelerometers (pre-PAO=22.6±25.2 mins/day; six-months after PAO=25.0±21.4 mins/day).

Conclusions: Individuals with AD reported significant pain reduction at one month and up to six months after PAO, but PA levels did not change six months after PAO compared to baseline testing. Future studies should consider examining longitudinal pain recovery and PA improvements over longer periods of time with larger samples of individuals with AD undergoing PAO and identifying modifiable factors to minimize pain and increase PA participation.

Level of evidence: III.