An observational study in Hip Osteoarthritis, Acute Traumatic Fracture of the Femoral Head or Neck and Avascular Necrosis of the Femoral Head, sponsored by Zimmer Biomet. Recruiting at 5 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-16.
Sponsored by Zimmer Biomet · Observational
The objectives of this study are to confirm the early to mid- term safety, performance, and clinical benefits of the Z1 Femoral Hip System in hemi- and primary total hip arthroplasty.
Cohort 0 The primary endpoint is defined by the survival of the implant system at 2 years, which is based on the absence of removal of the study device and will be evaluated using a one-sample proportion as well as using the Kaplan Meier method. The safety of the system will additionally be assessed by monitoring the frequency and incidence of adverse events, including relation to implant, instrumentation, and/or procedure.
The secondary endpoints are defined by the functional performance and clinical benefits of the study device and are assessed by patient-reported clinical outcomes measures (PROMs)(Hip dysfunction and Osteoarthritis Outcome Score for Joint Replacement (HOOS JR)).
Cohort 1 The primary performance endpoint is the assessment of the HOOS JR, specifically the within-patient change from baseline to 2-years post-op. The mean change from baseline will be compared against a minimal clinically important difference (MCID) of 9.46 points.
The key secondary safety endpoint is defined by the survival of the implant system at 2 years, which is based on the absence of removal of the study device and will be evaluated using a one-sample proportion as well as using the Kaplan Meier method. The safety of the system will additionally be assessed by monitoring the frequency and incidence of adverse events, including relation to implant, instrumentation, and/or procedure.
Exploratory outcomes include:
Total hip arthroplasty (THA) is a common operative treatment where an arthritic, degenerative or fractured hip joint is replaced with a prosthetic device if conservative options are unable to relief pain and debilitating symptoms. A femoral stem component is used in conjunction with a femoral head component for the replacement of the proximal femur in total hip or hemi hip arthroplasty. THA now includes young and active patients, as well as very old ones thanks to the continuous improvement in implant design. Major indications include osteoarthritis, rheumatoid arthritis, avascular necrosis (AVN) and hip fractures. The surgical procedure consists in replacing the head of the femur and acetabulum (socket) with a prosthesis. Another type of hip arthroplasty is called Hemi arthroplasty, which does not include the replacement of the acetabulum.
This system is composed of a femoral stem that is inserted into the femoral canal, a ball that attaches to the femoral stem, and an acetabular component or shell that replaces the acetabulum. Device components are made from durable materials that can withstand loads applied to the artificial hip joint during physical activity, are resistant to corrosion and fatigue, provide minimal friction and wear, and are biocompatible. Commonly used materials include cobalt chrome, commercially pure titanium, titanium alloy with aluminum and vanadium, ceramics, and ultrahigh molecular weight polyethylene.
Clinical studies have proven implant longevity in both cementless and cemented THA, offering patients effective long-term relief. In cementless THA, successful biological fixation is dependent on bony on-growth onto the surface of the prosthesis whereas, cemented fixation depends on a stable interface between prosthesis and cement and a solid mechanical bond between cement and bone. Ultimately, the goal of a THA is to bring the patients back to their normal routine without pain and stiffness. THA and hemiarthroplasty are both very successful procedures with an 84-97% patient satisfaction rate and an implant survival of over 90% after 10 years (THA) and implant survival of approximately 93% at 10 years (Hemiarthroplasty).
The Z1 Femoral Hip System consists of femoral hip stems intended for use in total or hemi hip arthroplasty. The triple-tapered stem is designed for implantation into the proximal femur and mates with compatible femoral heads and adapters for use in total or hemi hip arthroplasty through a 12/14 male taper connection.
The stems are manufactured from a forged titanium alloy Ti-6Al-4V and have a wedge-shaped design, with a proximal-to-distal taper. Apart from the highly polished femoral neck region, the entire surface of the stem is gritblasted and sprayed with a Ti-6Al-4V titanium alloy plasma coating followed by a hydroxyapatite (HA) overcoat. Offered in multiple sizes and neck lengths, the stems are available in Standard, High Offset, and Coxa Vara offsets to accommodate various patient anatomies. The hip stems are provided sterile and are for single use only. System-specific instrumentation is available to prepare the femur for implantation of the Z1 Hip System femoral stems. The Z1 Hip System is for use only with the Zimmer Biomet femoral heads and adapters, bipolar heads, and acetabular shells and liners identified in the package insert as compatible components.
641 studies on the registry are indexed under Osteoarthritis, Hip; 120 are open to participants now.
This study's planned enrollment of 300 is above the median of 135 across 158 observational studies indexed under Osteoarthritis, Hip.
Browse Osteoarthritis, Hip studies →Zimmer Biomet is the lead sponsor of 275 studies on the registry; 28 are open to participants now.
Of its 22 completed or terminated interventional studies of FDA-regulated products, 19 (86%) have results posted.
Counted across the registry records on this site, refreshed daily.
The study population should consist of up to 300 subjects implanted with the Z1 Femoral Hip System in hemi or total hip arthroplasty, according to the approved indications.
Inclusion and exclusion criteria are based on the indications and contraindications defined in the IFU for the Z1 Femoral Hip System.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Independent of study participation, patient is a candidate and qualifies for primary total hip or hemi-arthroplasty based on physical exam and medical history including at least one of the following:
Exclusion Criteria:
Any vulnerable subject:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Subjects implanted with the Z1 Femoral Hip System manufactured by Zimmer, Inc.: AristoTech (Luckenwalde, Germany)
Device: Z1 Femoral Hip System
Subjects implanted with the Z1 Femoral Hip System manufactured by Zimmer, Inc. (Warsaw, IN, USA)
Device: Z1 Femoral Hip System
Subjects who will be implanted with the Z1 Femoral Hip System in hemi-hip arthroplasty and primary total hip arthroplasty
2 Year Primary Outcome (Cohort 0)
The primary endpoint is defined by the survival of the implant system at 2 years, which is based on the absence of removal of the study device and will be evaluated using a one-sample proportion as well as using the Kaplan Meier method. The safety of the system will additionally be assessed by monitoring the frequency and incidence of adverse events, including relation to implant, instrumentation, and/or procedure. Cohort 1
Time frame: 2 years post-operative
2 Year Primary Outcome (Cohort 1)
The primary performance endpoint is the assessment of the HOOS JR, specifically the within-patient change from baseline to 2-years post-op. The mean change from baseline will be compared against a minimal clinically important difference (MCID) of 9.46 points.
Time frame: 2 years post-operative
HOOS Jr
Cohort 0: The functional performance and clinical benefits of the study device will be assessed by a patient-reported clinical outcomes measure (PROM)(HOOS JR).
Time frame: 5 years post-operative
Survivorship
Cohort 1: The key secondary safety endpoint is defined by the survival of the implant system at 2 years, which is based on the absence of removal of the study device and will be evaluated using a one-sample proportion as well as using the Kaplan Meier method. The safety of the system will additionally be assessed by monitoring the frequency and incidence of adverse events, including relation to implant, instrumentation, and/or procedure. Each secondary endpoint will be followed out to 5 years.
Time frame: 2 Years post-operative
Exploratory Outcome: EuroQol 5 Dimensions (EQ-5D)
Cohort 1: The EQ-5D-5L PROM will be collected preoperatively, 1, 2, and 5 years.
Time frame: 5 Years Postoperative
Exploratory Outcome: Patient Satisfaction
Cohort 1: Patient satisfaction will be collected at 6 months, 1, 2, and 5 years
Time frame: 5 years postoperative
Plan to share: Undecided
No publications or documents are linked to this record.
Started Oct 2025 (actual). Primary completion is estimated for Aug 2028, 34 months after the start.
Of 81 observational studies under Osteoarthritis, Hip, half reached primary completion within 53 months of starting (the median), counting those still running; a quarter within 13 and three quarters within 113. This study's planned 34 months is below that.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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