Physiotherapeutic Treat-to-target Intervention after Orthopaedic surgery; a cost-effectiveness study

INTERVENTION: Treat‐to‐target: optimized, personalized strategy implying that after receiving PT in the postoperative phase in the hospital will either or not be referred to primary care PT based on a standardized assessment of their health status, personal‐, external factors and achievement of functional milestones. Those needing PPT in primary care receive a standardized, time contingent program, focused on evidence‐based components muscle strengthening and functional exercises, with regular evaluations regarding achievement of functional milestones. After reaching the milestones, PPT is ended and patients will receive a tailored advice with home‐based exercises in combination with referral to exercise activities in the community. The treat‐to‐target PPT is based on scientific evidence and expert opinion and is presented in the form of a transmural care pathway. The final protocol has been registered. Usual care: Current PPT delivery. CONDITION: Post operative, Physiotherapy, Total knee arthroplasty, Total Hip Arthroplasty, Osteoarthritis ; ; PRIMARY OUTCOME: The difference between both groups in change between baseline and 3 month postoperative KOOS‐PS / HOOS‐PS score will be used as primary outcome.; ; Besides, differences in medical consumption, adverse events, absence from work or decreased productivity, and patient costs, will be assessed SECONDARY OUTCOME: Difference in scores of OKS/OHS, NRS, EQ5D, performance tests, physical activity level, as well as anchor questions, and satisfaction question. INCLUSION CRITERIA: Patients eligible for this trial are patients with clinical and radiological knee or hip OA who are scheduled for a primary TKA or THA, and willing to comply with the study protocol