A Safety Follow Up Study in Australian Subjects Implanted With the SMF Short Modular Femoral Stem Hip System

Terminated

Conditions: Total Hip Arthroplasty (THA)

Interventions: Device: SMF Short Modular Femoral Hip System

Registration Number: NCT03646513

Lead Sponsor: Smith & Nephew, Inc.

Brief Summary: This is a prospective, single arm, sequential enrolment study to collect relevant clinical and radiological data in approximately 26 subjects, at one site in Australia, who have been implanted with the SMF Short Modular Femoral Stem Hip System in a primary THA procedure to assess its safety and efficacy up to 20 years post-surgery.

Detailed Description: This is a single arm, consecutive series study to collect relevant clinical, laboratory and radiological data in up to 26 subjects, who have been implanted with the SMF Short Modular Femoral Stem THA system at 1 site in Australia.

The Baseline visit will be determined as the first visit to site after Ethics approval. This will be approximately 8-9 years post implant. Enrolled subjects will be followed up to 20 years post SMF implant.

Eligible patients will be contacted and patient status and implant revision status will be assessed at this initial contact. The subject will be given the option to participate in a prospective 12 year on-site follow-up visits for which they will provide written informed consent. Subjects who are lost to follow-up, deceased or are unwilling/unable to participate in the prospective study will be noted in the subject files and this data will be captured for analysis of study results. Data will be collected on the operative date, and implant status.

Post Baseline, the study will allow for metal ion assessments every 3 years for asymptomatic subjects and annual assessments for subjects with pain, swelling, and/or functional limitations if assessed by the Principal Investigator to be related to the SMF implant, having ruled out all other probable causes for the subject. If the subject has elevated whole blood cobalt or chromium (defined as \>7ppb) a MARS MRI or CT will be obtained. These types of imaging techniques are aimed at detecting inflammatory degenerative evolution of peri articular soft tissues including pseudo-tumours. A functional Questionnaire, HOOS JR Questionnaire will be completed at all patient site visits.

Safety will be evaluated by assessing the frequency and nature of adverse events, serious adverse events and revisions.

Recruitment & Eligibility

Status: TERMINATED

Sex: All

Target Recruitment: 4

Inclusion Criteria

The participant has undergone primary total hip arthroplasty with the SMF short modular femoral stem at the study site and still has the original implant at the time of Ethics Committee approval of the study.
The participant is willing and able to participate in follow-up visits at the study site.

Exclusion Criteria

The Subject, in the opinion of the PI, has an emotional or neurological condition that would affect their ability or willingness to participate in the study including mental illness, mental retardation, drug or alcohol abuse.
Subject is known to be at risk for lost to follow-up or failure to return for scheduled visits.

Study & Design

Study Type: OBSERVATIONAL

Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
SMF Short Modular Femoral Stem Implanted Subjects	SMF Short Modular Femoral Hip System	Subjects who have been implanted with the SMF Short Modular Femoral Stem for primary total hip arthroplasty.

Primary Outcome Measures

Name	Time	Method
Number of Participants With Cobalt (Co) and Chromium (Cr) Metal Ions > 7 Parts-Per-Billion (Ppb)	Baseline to study completion, up to 20 years	Number of participants with whole blood cobalt (Co) and/or chromium (Cr) \> 7 ppb (Yes/No). Participants as 'Yes' to Co and/or Cr will have Metal Artifact Reduction Sequence (MARS) Magnetic Resonance Imaging (MRI) performed (or Computerized tomography (CT) if MRI is contraindicated). This is used to detect pseudotumors, abductor muscle atrophy, and tendinous pathology in patients with painful metal-on-metal (MOM) hip arthroplasty.
Metal Ion Level	Baseline to Study Completion, up to 20 years	All participants at Baseline and every three years afterwards up to 20 years will have whole blood collected for metal ion testing of whole blood cobalt (Co) and chromium (Cr). Symptomatic participants with pain, swelling, and/or functional limitations if assessed by the Principal Investigator to be related to the implant will have whole blood collected for metal ion testing of cobalt and chromium annually.

Secondary Outcome Measures

Name	Time	Method
Number of Participants With Short Modular Femoral (SMF) Stem Revision	Study Completion, up to 20 years	Number of participants with a revision of any component of the SMF Short Modular Femoral Stem for any reason as a result of an adverse event. Revisions captured at any time during the study duration (up to 20 years) from the point of informed consent signing.
The Hip Osteoarthritis Outcomes Score Junior (HOOS JR) Questionnaire	Baseline to study completion, up to 20 years	The HOOS JR. questionnaire consists of 6 questions. These focus on 3 categories: joint pain, stiffness and function in daily living. The HOOS JR. questionnaire, allows patients to rate each activity by indicating the amount of pain or disability they experience while carrying them out. Raw scores are added up and then converted to an interval score (0-100) using an interval table. The final interval score represents a patients total joint disability where 0 corresponds to total joint disability (i.e., worse outcome) and 100 is perfect joint health (i.e., best outcome).
Radiographic Assessment: Loosening	Baseline to study completion, up to 20 years	Standard of Care Radiographic Assessment for loosening indicated by radiolucencies \> 2 millimeters (mm). In a cemented arthroplasty, this lucency at the bone-cement interface indicates the formation of a fibrous membrane (representing the lucency). Periprosthetic lucencies wider than 2 mm and/or progressive lucencies are signs of abnormality.
Radiographic Assessments: Surface Wear	Baseline to study completion, up to 20 years	Number of participants with evidence of surface wear (Yes/No) as indicated by early osteolysis, implant migration, or other clinical or radiographic abnormalities such as pseudo tumors or corrosion.