Participants include patients 18 years or older presenting to the investigators' institutions who are scheduled to undergo a primary total knee arthroplasty (TKA). Exclusion criteria include revision TKA, prior surgery or fracture involving the operative knee, preoperative knee flexion contracture greater than 10 degrees, patients with comorbidities, and those unable or unwilling to provide informed consent.
If, after evaluation, the patient remains eligible, the surgeon will introduce the study. If the patient expresses interest, a member of the study team will approach the patient to explain the study in detail. The voluntary nature of participation will be emphasized, and the prospective participant will be encouraged to ask questions and discuss participation with others. Once all questions have been addressed, the participant will be presented with the informed consent document (ICD). The study team member will step out of the room to allow time for review. If desired, the participant may take a paper copy of the ICD to discuss with family or others before signing. Once all questions have been answered to the participant's satisfaction, the ICD will be signed, preferably in the clinic. If the participant elects to take the ICD home, a follow-up time will be arranged, typically during preoperative clearance or on the day of surgery to review and sign the document.
After informed consent is obtained, preoperative baseline data including range of motion and patient-reported outcome measures will be collected. Participants will then be randomized in a 1:1 fashion to either receive or not receive photographic evidence of their postoperative knee range of motion. Randomization will be performed using stratified randomization lists generated and maintained by the Biostatistics Core at Loyola University Clinical Research Office to ensure equal allocation across sites.
During surgery, photographs of the operated knee in full flexion and full extension will be taken. Participants randomized to the intervention group will receive printed copies of the photographs and instructions to share them with their physical therapist. The control group will not receive any photographs. All participants will receive standard perioperative management, surgical technique, and rehabilitation protocols.
The primary outcome is knee flexion at six weeks postoperatively, measured using a goniometer by a blinded assessor. Secondary outcomes include knee extension, physical therapy progress metrics (total duration of therapy, time to achieve 110 degrees of flexion, and number of therapy sessions), distance walked on postoperative day one, length of hospital stay, and patient-reported outcomes via the Knee Injury and Osteoarthritis Outcome Score (KOOS) survey.
A sample size of 52 patients (26 per group) was calculated to provide 80% power to detect a 10-degree difference in knee flexion at six weeks, assuming a standard deviation of 12 degrees and a two-sided alpha level of 0.05.
Both groups will undergo standard postoperative follow-up at two weeks, six weeks, and as per routine care thereafter. Data collection at each time point will include range of motion assessments, physical therapy metrics, and KOOS surveys.
The investigators hypothesize that providing photographic evidence of postoperative knee range of motion will enhance patient motivation and engagement in rehabilitation, resulting in improved early range of motion and functional recovery compared to standard rehabilitation alone.
Participation in this study carries minimal risk. All procedures, surgical techniques, and follow-up care are consistent with the standard of care for patients undergoing TKA. The primary risk to participants is potential loss of confidentiality, which is rare. There are no additional surgical risks associated with participation. Subject safety will be monitored during routine postoperative visits, and participants will have access to the study team for any questions or concerns.
