Recovery and the use of postoperative physical therapy after total hip or knee replacement

BACKGROUND: Total hip or knee arthroplasties (THA/TKA) show favorable long-term effects, yet the recovery process may take weeks to months. Physical therapy (PT) following discharge from hospital is an effective intervention to enhance this recovery process. To investigate the relation between recovery and postoperative PT usage, including the presence of comorbidities, 6 months after THA/TKA. METHODS: Multicenter, observational study in primary THA/TKA patients who completed preoperative and 6 months postoperative assessments. The assessments included questions on PT use (yes/no and duration; long term use defined as ≥ 12 weeks), comorbidities (musculoskeletal, non-musculoskeletal, sensory comorbidities and frequency of comorbidities). Recovery was assessed with the HOOS/KOOS on all 5 subdomains. Logistic regression with long term PT as outcome was performed adjusted for confounding including an interaction term (comorbidity*HOOS/KOOS-subdomain). RESULTS: In total, 1289 THA and 1333 TKA patients were included, of whom 95% received postoperative PT, 56% and 67% received postoperative PT ≥ 12 weeks respectively. In both THA and TKA group, less improvement on all HOOS/KOOS domain scores was associated with ≥ 12 weeks of postoperative PT (range Odds Ratios 0.97–0.99). In the THA group the impact of recovery was smaller in patient with comorbidities as non- musculoskeletal comorbidities modified all associations between recovery and postoperative PT duration (Odds Ratios range 1.01–1.05). Musculoskeletal comorbidities modified the associations between Function-in-Daily-Living-and Sport-and-recreation recovery and postoperative PT. Sensory comorbidities only had an effect on Sport-and-recreation recovery and postoperative PT. Also the frequency of comorbidities modified the relation between Function-in-Daily-Living, pain and symptoms recovery and postoperative PT. In the TKA group comorbidity did not modify the associations. CONCLUSION: Worse recovery was associated with longer duration of postoperative PT suggesting that PT provision is in line with patients’ needs. The impact of physical recovery on the use of long-term postoperative PT was smaller in THA patients with comorbidities. TRIAL REGISTRATION: Registered in the Dutch Trial Registry on March 13, 2012. TRIAL ID NTR3348; registration number: P12.047. https://www.trialregister.nl/trial/3197. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12891-022-05429-z.