'Do Patient Characteristics Associate With Poor Outcome With Femoral Acetabular Impingement Syndrome (FAIS) Following Physiotherapy-led Rehabilitation'

STUDY DESIGN The study flow is shown in Appendix A which summarises the study. Patients will be invited to participate in this observational prospective cohort study.

Setting: Participants will be screened from 4 tertiary hospital sites recognised for the management and treatment for Femoral Acetabular Impingement Syndrome (FAIS). The hospital locations were chosen to cover a diverse population ranging from urban to rural locations, offering a broad range of backgrounds and culture according to the Office for National Statistics Census of Population. Across hospital involvement will reduce spectrum and selection bias. All participants will be approached prior to attending their Physiotherapy-Led Rehabilitation (PLR) with a diagnosis of FAIS at the specialist orthopaedic hip clinics. However, alternative centres are available should the situation change at any of these between application and study onset.

Participants: will be recruited from relevant hip clinics and from the hospital that they are attending. The participants will be approached by a research assistant and a study information pack after identified by a clinician. Participants who have a formal diagnosis of FAIS by an orthopaedic doctor/registrars or physiotherapists will be screened for eligibility.

Consent: Patients with mental capacity who have a proven understanding of the English language will be approached. The consent form, questionnaires and information pack will be accessible on-line via a QR code linked to a free secure web-based data collection platform (REDCap). An information pack including a letter of invitation, Patient Information Sheet explaining the nature of the study and an informed consent form will be included in paper form, if participants would prefer a printed copy of the questionnaires and the results manually inputted.

• Outcome measures: Baseline physical hip characteristics will be collected from MRI or Xray findings: Cam size (alpha angle), Osteoarthritis (OA)(Kellgren Lawrence staging of OA), and radiological co-morbidities on MRI (e.g., gluteal tendinopathy) Pain Phenotyping • Douleur Neuropathique-4, Widespread Pain Index, Neuropathic Pain Symptom Inventory. Psychometric measurements, Tampa scale of Kinesiophobia (TSK-17), Hospital Anxiety and Depression scale (HADS), Pain Catastrophising Scale (PCS), Credibility/Expectancy Questionnaire (CEQ), Treatment Expectation Questionnaire (TEX-Q), Quality of Life: International Hip Outcome Tool (iHOT-33). • Visual analogue scale for average pain over 4 weeks, Hip range of movement The two additional outcome measures in the form of questionnaires (CEQ and TEX-Q) have been included based on feedback from the PPIE group. For participants unable to access the QR code, a paper copy of the questionnaires will be provided with a self-addressed stamped envelope.

Data collection: Baseline data will be collected and include patients' mobile number, postal code, landline number and email address, cross checked with the patient to confirm correct contact details. Participants demographics: age, sex, ethnicity, weight, height, body Mass index (BMI), duration of symptoms, smoking history, laterality of the hip pain, level of education, marital and social status, work status, medication, patient expectations of PLR, hospital location and comorbidity data. Alpha angles calculated by consultant radiologists and other features from the MRI e.g. gluteal tendinopathy (to document potential confounders) and other characteristics identified from the systematic review. The results of the patient reported questionnaires will be collated and anonymised and recorded electronically.

Sample size calculations: The investigators have based the sample size calculations on the primary purposes of the data analyses exploring the strength of the relationships between variables. The investigators plan for 9 variables identified from the questionnaires and ongoing systematic review where the number of participants required per variable for a multivariable linear regression model is 10-15. Allowing for 15 participants per variable and a 30% attrition rate lost to follow up, an a priori power analysis indicated that a minimum sample size of 175 patients would provide 80% statistical power with an alpha set at 0.05 based on the primary purposes of the data analyses. Power calculations will be crossed checked with a statistician.

Statistical analyses:

The investigators will undertake descriptive analysis of the data and will document counts, means, standard deviations or medians and interquartile ranges where appropriate. A multiple regression analyses will be performed exploring the association of the baseline variables and Correlational statistics will be used to explore the relationships between the variables.

Data management: All data will be recorded on REDCap which is a secure web-based data collection platform. Clinical data will be stored separately from patient identifying data. All data will be password and firewall protected. All paper records will be kept in a secured locked room in locked filing cabinets used to store patient data at the Physiotherapy Research Unit (Nuffield Orthopaedic Centre).

Participants will be issued appropriate questionnaires after 4 months from commencement of their PLR program. This will be done via either paper copy of the questionnaires or via a QR code that is linked to REDcap secured database or emailed automatically by REDcap.

Aim and objective. To identify whether pain phenotypes, psychological, social and demographics associate with poor outcomes after a PLR programme as defined by ongoing pain and/or hip stiffness and limited range of hip movement.

The questionnaires along with patient characteristics identified from the systematic review will be collected to determine if there is an association between the variables and poor outcome.

Recruitment and retention strategy. Clinical staff will be notified of the study via presentations in governance meetings, posters in clinic rooms and waiting areas and emails and a clear effective line of communication will be available for clinical staff to contact me. The posters are aimed to recruit the patients but will remind clinicians of the study. Regular visits are planned for the 4 sites to ensure a close working relationship with clinical staff and to monitor the recruitment process is on target and address any issues. Ongoing communication with the Patient and Public Involvement Engagement group to discuss strategies they identify which could be implemented to assist in recruitment and retention. Furthermore, strategies will be used for recruitment and retention using methods identified by including:

* Information on nature of the study, participants requirements detailing potential benefits and follow up. * Create project identity and logo on all study correspondence. * Contact and scheduling methods. * Non-financial incentives including a letter of appreciation. * Providing reminders to complete the questionnaires and self-stamped addressed envelopes for return of post. * Obtaining multiple contacts for each participant Data collection time points (from baseline to 4 months): Prior to starting PLR, the research assistant will measure hip range of movement (flexion, extension, abduction, adduction, internal rotation and external rotation, and two impingement tests Flexion Adduction Internal Rotation (FADIRS) and Flexion Abduction External Rotation (FABERS). The participant will be given the study Questionnaires: iHOT33 (Health related Quality of Life) and Visual Analogue Scale (VAS) for pain intensity, TSK, WPI, HADS, PCS, DN4, NPSI, CEQ and TEX-Q.

At 4 months after commencement of treatment the participant will be given the iHOT33 questionnaire and pain intensity score (VAS). No other measurements will be taken.

A standard routine physiotherapy-led rehabilitation and follow up provides routine care that is provided in an National Health Service (NHS) setting. A PLR programme including (i) an individualised and progressive exercise program, (ii) education and its management, and (iii) advice regarding pain relief and avoiding positions of discomfort and activity are key features to the intervention, individualisation, progression and supervision. A treatment log will be kept documenting clinical treatment type, progression and exercise prescription with sets and repetitions. Fidelity will be checked by randomly selecting 10 sets of Physiotherapy notes to ensure routine standard care physiotherapy as detailed above is adhered to. Four months will mark the duration of the study from commencement of PLR to follow up irrespective whether the participant is still undergoing PLR. At the beginning of PLR the patient's pain, function and hip range of movement will be documented.

At 4 months, the physiotherapist will direct the patient to the QR code (or a paper copy if required) to complete the questionnaires if still undergoing PLR or REDcap will automatically email the questionnaires if the participant has finished their PLR. Working closely with the PPIE group will ascertain preferred methods of filling out the questionnaires whether electronically or paper format and to advise on retention strategies. It is planned that non responders will be contacted via a follow-up telephone call and letter and email if data is still missing but this will be reviewed on feedback from the PPIE group. After three attempts contacting the participant, no further attempt will be used to contact the participant. Paper copies of the questionnaire will be posted with a self-addressed stamped envelope if requested by the participant.

Recruitment Four centres have been selected from existing clinical and research networks. The four hospital locations were chosen to cover a diverse population ranging from urban to rural locations and offering a broad range of backgrounds and culture according to the ONS Census of Population. These centres have been identified as tertiary referral centres for management of hip conditions.

Patients will be identified when attending hip clinics at their participating hospital. Following a clinical assessment by the clinician (Consultants, Registrars in Orthopaedics or Sports and Exercise Medicine or advanced practitioner physiotherapist working in the hip clinic) and appropriate imaging/referral for imaging and formal diagnosis of FAIS, patients will be introduced to the study by the assessing clinician. The initial sites for this study are the 4 sites mentioned above. The Orthopaedic and Sports and Exercise Medicine team will be informed of the study by formal meetings and posters in clinic rooms to remind them of the study and to identify potential participants.

If the participant expresses an interest in the study, they will be introduced to a research assistant. The research assistant will provide an information pack with a QR code to scan which will provide more details of the study. A paper information pack will be given upon request. If the patient agrees to register for the study and participate, then the research assistant will use a clinic room and collect baseline data and consent the patient to the study. Clinicians will not be asked to obtain consent due to the nature of the busy clinics.

Description of study intervention(s), comparators and study procedures (clinical) The participants will be referred to a PLR as part of the 'routine standard care' pathway following the diagnosis of FAIS and is not part of the study. This study is purely observational and no treatment intervention or comparators. A treatment log will be kept documenting treatment type, progression and exercise prescription with sets and repetitions. Fidelity will be checked by randomly selecting 10 sets of Physiotherapy notes to ensure routine standard care physiotherapy as detailed above is adhered to.

There is no comparator in this study design. Description of study procedure(

• Neuropathic Pain Symptom Inventory (NPSI) [Time frame: On the day of enrolment or within one week]
• • Douleur Neuropathique 4 -Interview [Time frame: On the day of enrolment or within one week]
• Hospital Anxiety and Depression scale (HADS): [Time frame: on the day of enrolment or within one week]
• Widespread pain index (WPI) [Time frame: On the day of recruitment or within one week]
• Pain Catastrophising Scale (PCS) [Time frame: On the day or enrolment or within one week.]
• Tampa Scale of Kinesiophobia (TSK17) [Time frame: This is a commonly used self-reported questionnaire quantifying the fear of movement or re-injury. The TSK shows a high level of internal consistency and demonstrated moderate construct validity. Concurrent validity is moderate ranging from r =0.33-0.59]
• Credibility/Expectancy Questionnaire (CEQ) [Time frame: On the day of enrolment or within one week.]
• Treatment Expectation Questionnaire (TEX-Q) [Time frame: On the day of enrolment or within one week]