MCID and PASS for Acute Pain and Quality of Recovery After Orthopedic Surgery

This study seeks to define what constitutes an MCID and a PASS in patients undergoing a variety of elective major orthopedic surgery.

Inclusion Criteria: * Adult patients aged 18-80 years * ASA class I - III * Primary elective surgery * unilateral major shoulder surgery e.g., stabilization and arthroplasty procedures: * unilateral total hip replacement * unilateral total knee replacement, and * spinal decompression + fusion involving ≥ 2 levels. * Hospital admission for ≥ 24 hours after the surgery Exclusion Criteria: * Inability to give informed consent * Poor English comprehension * Psychiatric disorders e.g., dementia * Known allergies to morphine / hydromorphone * Chronic substance abuse and use of recreational drugs * Any medical disorder that impairs accurate and objective completion of questionnaires