This observational retrospective study aims to assess the rehabilitation outcomes of patients who underwent total hip arthroplasty (THA) and were monitored through a mobile application versus those who were not. The hypothesis is that patients who receive postoperative follow-up via a mobile app, which includes a recovery exercise program, will experience significantly greater improvements in functionality, quality of life, and treatment adherence compared to those who do not use the app after three months of follow-up.

The study will analyze the records of patients from two cohorts: one group monitored with the mobile application and another group receiving standard postoperative care without the app. Data on patients' functionality, quality of life, and adherence to treatment will be collected and compared between the two groups. This study seeks to provide evidence on the effectiveness of digital health interventions in enhancing postoperative recovery for THA patients.

This study adopts an observational, analytical, longitudinal, and retrospective design with two cohorts: an exposed cohort and a non-exposed cohort, aimed at evaluating the effectiveness of a follow-up program using a mobile application in patients undergoing total hip arthroplasty.

Patients selected for this study have undergone total hip arthroplasty using the Furlong Evolution® short stem and acetabular cup prosthetic design (ACE). Surgeries were performed at Hospital San Juan de Dios de Santurtzi and Hospital Universitario de Galdakao, both located in Vizcaya.

To analyze the new care model (functional recovery program and patient follow-up via a digital application), the entire study population from June 1, 2023, to March 30, 2024, will be included, conducting a complete cohort analysis with a 3-month follow-up period.

Data collection includes sociodemographic, clinical, and pre-surgical functional characteristics. Specific assessment tests were employed to evaluate pain, function, and quality of life.

Electronic health records will be used to collect data, including demographic variables (age, gender), medical history, Patient-Reported Outcome Measures (PROMs) such as the Harris Hip Score and WOMAC scale and Patient-Reported-Experience-Mesures (PREMs) as satisfaction scale.

Quality assurance procedures will be implemented to ensure data validity and registry integrity, including data validation checks, source data verification against external sources, and a comprehensive data dictionary detailing each variable's origin and coding information.

Standard Operating Procedures (SOPs) will guide registry operations, including patient recruitment, data collection, management, analysis, adverse event reporting, and change management.

A statistical analysis plan will employ appropriate analytical principles and techniques to address primary and secondary objectives outlined in the study protocol, assessing the sample size required to demonstrate significant effects and strategies for handling missing data.

This detailed description encompasses the comprehensive framework and methodology of the study, emphasizing rigorous data collection, quality assurance measures, and statistical analysis strategies essential for evaluating the effectiveness of the mobile application-based follow-up program in post-total hip arthroplasty patients.

Inclusion Criteria:

• Patients over 18 years old operated at Hospital San Juan de Dios de Santurtzi and Hospital Universitario de Galdakao, both located in Vizcaya.
• Operated on for total hip arthroplasty with the Furlong Evolution short stem prosthetic design and ACE acetabular cup.
• Patients who have started postoperative rehabilitation program with or without the mobile application.
• Ability to walk before the fracture with or without the aid of instruments or persons.
• Access to a smartphone with the ability to install applications.
• Patients with complete PROMs data using the Harris Hip Score and WOMAC scale available.

Exclusion Criteria:

• Patients with incomplete data or lack of follow-up at three months.
• Patients with severe comorbidities that may significantly affect mobility and functionality.
• Patients with cognitive impairment that precludes the use of the mobile application for recovery.

Patients undergoing total hip arthroplasty: Patients were selected who underwent total hip arthroplasty using the same prosthetic design, Furlong Evolution® short stem and ACE acetabular cup. Surgeries were performed at Hospital San Juan de Dios de Santurtzi and Hospital Universitario de Galdakao, both located in Vizcaya.