Pre-arthritic hip disorders can cause pain, interfere with daily activities and exercise, and lead to the development of osteoarthritis in young adults. Surgical and conservative treatment options are being developed and studied, but it is currently unclear why some patients improve with a particular treatment plan while others do not. The goal of this research project is to develop a tool that predicts which combination of treatment options will be most effective for each individual patient.

Significance: Pre-arthritic hip disorders (PAHD) are bony and soft tissue hip morphologies that predispose adolescents and young adults to developing hip pain, chronic impairment, and early osteoarthritis (OA). Proper management may prevent these sequelae, but current evidence, especially regarding non-operative treatment options, is limited.

Innovation: The majority of PAHD has so far addressed identification and correction of abnormal hip anatomy via surgical management. However, a growing body of evidence suggests that several other variables including patients' functional goals, movement patterns, and psychological profiles also affect their symptomatology. These risk factors are modifiable but are not routinely or adequately addressed. The innovation of this project is to improve patient outcomes by evaluating patients with a more comprehensive, patient-specific approach than is currently the standard of care.

Purpose: The purpose of this project is to identify predictors of response to non-operative PAHD treatment options and to synthesize these predictors into a clinical prediction tool that informs non-operative one-year outcomes using data available during patients' initial evaluation. In this prospective observational study, patients who present to an orthopedic physician for PAHD will be provided instruction on movement pattern training, which is a standardized activity modification protocol that addresses how patients perform routine and strenuous activities in order to reduce hip pain. It has proven to be efficacious in a randomized trial setting, but it is not yet widely discussed by physicians in the clinic setting. Patients will report adherence and response to the movement pattern training at scheduled intervals for 12 weeks, and they will also report persistent hip-related dysfunction and/or progression to surgery at 6 and 12 months. A clinical prediction tool of one-year outcomes will be developed using patients' demographics, biopsychosocial profile, movement and activity patterns, and anatomy as candidate predictors. The analysis will also determine a minimum combination of patient-reported outcome measures (PROMs) that reduces survey burden while maintaining similar predictive utility when compared to administration of a full battery of hip-specific and general health PROMs.

Impact: This study is the first step in creating and validating a clinical prediction tool which will guide management for patients with pre-arthritic hip disorders. This line of research will equip clinicians to provide more accurate prognostic counseling at initial evaluation so that an informed shared decision can be made with the patient and initiation of an appropriate comprehensive management plan can be expedited.

Inclusion Criteria:

• Clinically suspected intra-articular hip joint pain
• One or more of the following radiographic/MRI findings: Femoroacetabular impingement, acetabular dysplasia, acetabular labral tear, acetabular retroversion, femoral anteversion, hip microinstability, and/or normal radiographs

Exclusion Criteria:

• Surgery recommended and/or scheduled at initial clinic evaluation
• "At-risk" acetabular dysplasia (Lateral center edge angle < 15 degrees)
• Other intra-articular hip diagnoses including: Slipped capital femoral epiphysis, Legg-Calve-Perthes disease, Avascular necrosis
• Moderate or severe hip osteoarthritis (Tonnis grade 2 or 3)
• Hip/pelvis weakness from brain/nerve disorder (Ex: lumbosacral radiculopathy with weakness, cerebral palsy)
• Previous same-side hip surgery, hip fracture, hip infection, and/or hip tumor
• Inflammatory arthropathy
• Known pregnancy

Participants will be recruited from patients who present to a single tertiary care academic orthopedic department. Potentially eligible patients will have presented to an orthopedic surgeon or sports medicine physiatrist for a new evaluation of hip pain.

The investigators are amenable to sharing individual participant data (IPD) when all anticipated data analyses are complete. However, the data generated from this study may be used for future validation efforts of new versions of the clinical prediction tool. The IPD will likely not be made available until there is reasonable confidence that no further data analyses are planned.