POLARSTEM Cementless Hip Stem (POLARSTEM)

Multicenter Clinical Observation Using the Cementless Version of the POLARSTEM

Multicenter observational study to validate that the POLARSTEM™ is a state-of-the-art implant in terms of radiographic, clinical performance and long-term survivorship.

Study Overview

• Status: Completed
• Conditions: Osteoarthritis
• Intervention / Treatment: Device: Total Hip Arthroplasty

Detailed Description

The goal of this multicenter clinical observation is to validate short-, mid-, and long-term outcome (efficacy and safety) of the POLARSTEM™.

Efficacy evaluations:

• Evaluation of function, range of motion (ROM) and pain as assessed by Harris Hip Score, Hip disability and osteoarthritis outcome score (HOOS) [7, 8], an extension of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC).
• Radiographic changes as defined by radiolucent lines, osteolysis, hypo- and hypertrophy, implant loosening or migration

Safety evaluations:

• Intra- and perioperative device-related adverse events (AE) and complications up to discharge
• Postoperative AE up to 10 years

• Study Type: Observational
• Enrollment (Actual): 218

Contacts and Locations

Study Locations

• Germany
  • Bochum, Germany, 44787
    • St. Elisabeth Hospital, Orthopedics and Rheumatology
  • Marburg, Germany
    • University Marburg, Orthopedics and Rheumatology
• Switzerland
  • Aarau, Switzerland, 5001
    • Kantonsspital Aarau, Orthopedics

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Patients enrolled in this multicenter clinical observation will have at least one of the indications listed below and meet all of the inclusion criteria. Patients meeting any of the exclusion criteria are not eligible for this study.

Indications

• Primary or secondary coxarthrosis
• Rheumatoid arthritis
• Developmental dysplasia of the hip (Crowe type I and II)
• Fracture or avascular necrosis of the femoral head

Description

Inclusion Criteria:

• Patient has no general medical contraindication to surgery
• Informed consent to participate in the MCO signed by the patient
• Routine radiographic assessment is possible
• Patient is likely to comply with study follow-up requirements
• Primary total hip replacement (THR) to the affected side, unilateral or bilateral

Exclusion Criteria:

• Previously failed endoprosthesis and /or THR components in relevant hip
• History of infection in the affected joint; systemic infections
• Grossly insufficient femoral or acetabular bone stock in the involved hip
• Charcot joint disease or other severe neurosensory deficit
• Severe spinal disorders
• Age of patient at date of surgery > 75 years
• High comorbidity
• Cemented acetabular cup

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Kaplan-Meier Estimate: Overall Survivorship of POLARSTEM	Overall survivorship of the Cementless Version of the POLARSTEM pre-operatively, 3 months, 12 months, 12 months, 36 months, 60 months, and 120 months by Kaplan-Meier estimate with overall hip survivorship defined as the time between date of treatment and date of revision for any reason.	Pre-operatively, 3 months, 12 months, 36 months, 60 months, and 120 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Harris Hip Score (HHS)	The HHS measured function, range of motion (ROM), and pain sub-scores that are combined to indicate total dysfunction on a numerical scale from 0 to 100, with a higher score indicating less dysfunction (i.e., a better outcome). Reported scores for the HHS utilized the following grading: <70 = poor; 70 to 80 = fair; 80 to 90 = good; 90 to 100 = excellent	Pre-operative, 3 Months, 12 Months, 36 Months, 60 Months, 120 months
Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC): Pain Subscale	WOMAC Pain subscale is a subset of the Hip Disability and Osteoarthritis Outcome Score (HOOS) with a range of 0 to 20. Higher WOMAC scores indicate worse pain (i.e., worse outcome) and lower scores indicate less pain (i.e., a better outcome).	Pre-operative, 3 Months, 12 Months, 36 Months, 60 Months, 120 Months
Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC): Stiffness Subscale	WOMAC Stiffness subscale is a subset of the Hip Disability and Osteoarthritis Outcome Score (HOOS) with a range from 0 to 8 with a higher score indicating a worse outcome and a low score indicating a better outcome.	Pre-operative, 3 Months, 12 Months, 36 Months, 60 Months, 120 Months
Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC): Physical Function Subscale	WOMAC Physical Function subscale is a subset of the Hip Disability and Osteoarthritis Outcome Score (HOOS) with a range from 0 to 68 with a higher score indicating a worse outcome and a low score indicating a better outcome.	Pre-operative, 3 Months, 12 Months, 36 Months, 60 Months, 120 Months
Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC): Total Score	WOMAC total score combines Stiffness, Pain, and Physical Function subscales of the Hip Disability and Osteoarthritis Outcome Score (HOOS) into a range from 0 to 96 with a higher score indicating a worse outcome and a lower score indicating a better outcome.	Pre-operative, 3 Months, 12 Months, 36 Months, 60 Months, 120 Months
Radiological: Radiolucent Lines	Number of hips identified with radiographic findings of radiolucent lines present (Yes/No) in femoral zones 1 to 14. Radiolucent lines indicated seams of 0 millimeters to 2 millimeters or greater.	3 months, 12 months, 36 months, 60 months, 120 months
Radiological: Osteolysis	Number of hips identified with radiographic findings of osteolysis present (Yes/No) in femoral zones 1 to 14.	3 months, 12 months, 36 months, 60 months, 120 months
Radiological: Atrophy	Number of hips identified with radiographic findings for atrophy in femoral zones 1 to 14 indicated as: None; Mild; Moderate; Severe; Missing	3 months, 12 months, 36 months, 60 months, 120 months
Radiological: Hypertrophy	Number of hips identified with radiographic findings for hypertrophy in femoral zones 1 to 14 indicated as: None; Mild; Moderate; Severe; Missing	3 months, 12 months, 36 months, 60 months, 120 months
Radiological: Loosening of the Implant or Migration	Number of hips identified with radiographic findings associated with loosening of the implant or migration were indicated as: Integration not assessable; Indifferent, bone unchanged; Osteointegration, integration; Bone loss; Signs of loosening; Revision indicated	3 months, 12 months, 36 months, 60 months, 120 months

Collaborators and Investigators

• Sponsor: Smith & Nephew, Inc.
• Investigators: Principal Investigator: Turgay Efe, Dr.med., Philipps University Marburg

Publications and helpful links

General Publications

• Cypres A, Fiquet A, Girardin P, Fitch D, Bauchu P, Bonnard O, Noyer D, Roy C. Long-term outcomes of a dual-mobility cup and cementless triple-taper femoral stem combination in total hip replacement: a multicenter retrospective analysis. J Orthop Surg Res. 2019 Nov 21;14(1):376. doi: 10.1186/s13018-019-1436-y.

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2009
• Primary Completion (Actual): November 1, 2020
• Study Completion (Actual): November 1, 2020

Study Registration Dates

• First Submitted: January 5, 2016
• First Submitted That Met QC Criteria: January 5, 2016
• First Posted (Estimated): January 6, 2016

Study Record Updates

• Last Update Posted (Actual): January 21, 2026
• Last Update Submitted That Met QC Criteria: January 2, 2026
• Last Verified: December 1, 2021

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Arthritis; Joint Diseases; Rheumatic Diseases; Osteoarthritis; Surgical Procedures, Operative; Arthroplasty, Replacement; Arthroplasty; Orthopedic Procedures; Plastic Surgery Procedures; Prosthesis Implantation; Arthroplasty, Replacement, Hip
• Other Study ID Numbers: D10070-1

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO