Periacetabular Osteotomy and Co-designed rehabilitation versus Co-designed rehabilitation in adolescents and young adults with hip dysplasia: a randomised controlled trial.

PAO Surgery and co-designed rehabilitation: PAO surgery is performed by expert orthopaedic surgeons in usual practice, and will be performed by these surgeons at participating treatment hospitals (partner-hospitals), using contemporary, best practice procedures (Reimer, L. et al, 2019). PAO surgery typically lasts 2-3 hours. Following PAO, patients remain in hospital four to five nights with restricted weight-bearing prior to commencing gentle mobility exercises. The PAO surgery will be followed by best practice post-operative rehabilitation, which will commence after 2 weeks, once clearance from the surgeon has been obtained at the routine post-operative surgeon review. Weight-bearing restrictions determined by the surgeon, will be incorporated into the Co-designed rehabilitation program. Registered physiotherapists will lead the targeted rehabilitation program intervention to be delivered over the 12-month period, described using the Template for Intervention Description and Replication (TIDieR) guidelines. The PAO surgery group post-operative rehabilitation intervention is the same co-designed rehabilitation program as that provided to the control group. It is a patient-centered, exercise program informed by the Danish adult Developmental Dysplasia of the Hip (DDH) randomised controlled trial (RCT) led by CI Mechlenburg (Reimer, L. et al, 2019), modified for adolescent participants and the Australian healthcare system following input from consumers, including guidance on its feasibility and appropriateness. It targets known functional impairments in those with DDH (O'Brien, M. et al, 2021). Participants will set individual goals and be educated regarding safe return to physical activity. The Co-designed rehabilitation program includes three face-to-face and twelve further face-to-face/video physiotherapy consultations over 12 months. The first session is an extended initial (60 minute) consultation (pre-operatively and occurring within two weeks of planned surgery for the surgical group) to commence all non-weightbearing exercises and commence postural sway correction training. All subsequent sessions are 30 minutes (occurring post-operatively for the surgical group). The extended-initial, two and six week sessions will be face-to-face but for all other sessions, telehealth will be offered. In Phases 1-3 participants perform 1-2 unsupervised select movement pattern training exercises, daily. In Phase 3 participants perform one unsupervised strength training session weekly, progressing to two sessions in Phases 4-5. Weight-bearing restrictions are incorporated into the co-designed rehabilitation program and both groups perform the same exercises, but the surgery group commences two to four weeks post-surgery. The approximate timeframes are as follows: • Phase 1 refers to pre-surgery to 6-8 weeks post-op (surgical group) or baseline to weeks 4-6 (non-surgical group). • Phase 2 then refers to the following weeks up to week 10 for both groups. • Phase 3 refers to weeks 10 to weeks 12-14. • Phase 4 refers to approximately week 14 to week 18. • Phase 5 (the final phase) then refers to week 20 onwards. Phase 1-4 progressions are based on acceptable pain levels (no increase >2/10) and time and Phase 5 progressions are based on rate of perceived exertion (RPE 5-6). The focus areas for the various phases are as follows: Phase 1 o Activation of key muscle groups (non-weightbearing e.g. sidelying hip abduction) o Movement pattern retraining: ensure good standing posture and weight transfer (semi-weightbearing) Phase 2 o Weightbearing uniplanar pattern retraining (full weightbearing) e.g. drinking bird o Low-risk gym exercises (e.g. calf raises) Phase 3 refers to weeks 10 to weeks 12-14 o Multiplanar movements (e.g. windmills) o Single-leg progressions (e.g. single leg control and step) o Strengthening gym-type exercises (e.g. bodyweight lunges) Phase 4 o Multiplanar single-leg movements with added complexity (e.g. triple extension drive) o Strengthening gym-type exercises (double-leg and single-leg) (e.g. squats) Phase 5 (the final phase) then refers to week 20 onwards o Sport specific rehabilitation-choice of 3 streams depending on sport (e.g. high-speed running stream, change of direction stream and conditioning stream). The Co-designed, five-phase rehabilitation program will be provided by experienced physiotherapists trained in the study rehabilitation protocol. All participants will receive weekly text messages to enhance adherence and motivation, as recommended by our consumer steering committee (Nelligan, R. et al, 2019). Fidelity checks of treatment sessions and auditing of treatment notes will take place. Screws remain in place until 4-12 months post operatively as is routine best practice internationally. In addition to Co-designed rehabilitation, all participants will receive a 60 minutes assessment by a registered mental health clinician, occurring within two weeks of intervention commencement dates for both groups (pre-operatively for the surgery group, and before the first physio appointment for the rehab group). The mental health clinician will also provide an educational intervention session (60 minutes) before the study intervention (pre-operatively for the surgery group and before the physio appointment for the rehab group). A 30-minute follow-up educational intervention session, will occur post-operatively for the surgery group and after physiotherapy commencement for the rehab group. All mental health sessions will be delivered via zoom. If the initial assessment raises concerns about the participant’s mental health, they will be referred to their general practitioner for evaluation. A mental health care plan may be provided if considered appropriate by the general practitioner. The additional support of a mental health clinician was requested by our consumer group as a critical element of the rehabilitation treatment package.