Assessment of Implant Fixation and SF-36 for Short Hip-Stems - A Prospective Clinical Study

The primary purpose of this study was to evaluate the implant fixation of the NANOS™ Neck Preserving Hip Stem (OHST Medizintechnik AG, distributed by Smith & Nephew GmbH, Marl, Germany) by measuring the migration of the implant using the model-based roentgen stereophotogrammetric analysis (MBRSA).

Study Overview

• Status: Completed
• Conditions: Primary and Secondary Coxarthrosis; Dysplasia Coxarthrosis; Post-traumatic Necrosis of the Femoral Head
• Intervention / Treatment: Device: Total Hip Arthroplasty

• Study Type: Observational
• Enrollment (Actual): 60

Contacts and Locations

Study Locations

• Germany
  • Hannover, Germany, 30625
    • Orthopädische Klinik der Medizinischen Hochschule Hannover

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 30 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients identified in the primary care clinic with need for total hip arthroplasty

Description

Inclusion Criteria:

• Subject required primary total hip arthroplasty unilateral or bilateral with a diagnosis of primary and secondary coxarthrosis, dysplasia coxarthrosis and post-traumatic necrosis of the femoral head confirmed by x-ray analysis. For bilateral subjects at least three months between surgical procedures were required.
• Subject was willing to consent to participate in the study and planned to be available for the follow-up examinations.
• Subject had normal motor function of the lower extremities, documented through clinical examinations and lack of signs of a neurological disease with changed motor function.
• Subject was 30 to 65 (inclusive) years of age at time of surgery.

Exclusion Criteria:

• Subject had previous bone or soft tissue surgery of the affected hip except for arthroscopic surgery.
• Subject had a local or systemic infection.
• Subject had previously diagnosed osteoporosis.
• Subject had a femoral neck angle of >145°.
• Subject had a femoral neck angle of <125°.
• Subject had a disease of the cardiovascular system involving particularly reduced load capacity in the everyday life, counting as contraindication of physical stress (American Society of Anaesthesiologists' (ASA) Score 3 or 4).
• Subject had a documented allergy against elements of the implanted device.
• Subject had a neurological disease with changed motor function.
• Subject was pregnant.
• Subject had a Body Mass Index (BMI) > 30.
• Subject suffered from alcoholism or addictive disorders.
• Subject needed a revision hip arthroplasty.
• Subject had an insufficient command of the language to understand patient information and consent.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
NANOS; NANOS™ Neck Preserving Hip Stem	Device: Total Hip Arthroplasty

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Evaluation of migration pattern of the Nanos stem	Measuring migration used the model-based RSA method	2 years
Change in quality of life	Measuring change in quality of life using the Short Form (SF) 36 Mental Component Score; Minimum Value: 0 (worst outcome); Maximum Value: 100 (best outcome)	2 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Harris Hip Score	Investigator assessed outcome score Minimum: 0 (worst outcome) Maximum: 100 (best outcome)	2 years
University of California, Los Angeles (UCLA) scale	Score rating the patient's current activity level; Minimum: 1 (wholly inactive subject); Maximum: 10 (totally active subject)	2 years
Pain Visual Analogue Scale	Score representing patient's current pain intensity; Minimum: 0 (no pain); Maximum: 100 (very severe pain)	2 years
Postel Merle d'Aubigné-Score	Score grading the functional value of the hip; Minimum: 0 (worst outcome); Maximum: 6 ( best outcome) Grading is done in each of the three dimensions: pain, mobility and ability to walk.	2 years
Hip Disability and Ostheoarthritis Outcome Score	Patient reported outcome; Minimum: 0 (best outcome); Maximum: 96 (worst outcome)	2 years
Radiographic Evaluation	Evaluation of radiographic images regarding implant position, implant fixation, heterotopic ossifications (HO), radiolucencies, osteolysis, atrophy and hypertrophy	2 years
Number of adverse events	Collection of adverse events	2 years

Collaborators and Investigators

• Sponsor: Smith & Nephew Orthopaedics AG
• Investigators: Principal Investigator: Henning Windhagen, Prof. Dr. med., Orthopädische Klinik der Medizinischen Hochschule Hannover

Study record dates

Study Major Dates

• Study Start (Actual): April 26, 2011
• Primary Completion (Actual): January 4, 2017
• Study Completion (Actual): February 15, 2017

Study Registration Dates

• First Submitted: November 19, 2019
• First Submitted That Met QC Criteria: November 19, 2019
• First Posted (Actual): November 21, 2019

Study Record Updates

• Last Update Posted (Actual): November 27, 2019
• Last Update Submitted That Met QC Criteria: November 25, 2019
• Last Verified: November 1, 2019

More Information

Terms related to this study

• Keywords: THA; Nanos; MBRSA
• Additional Relevant MeSH Terms: Pathologic Processes; Joint Diseases; Musculoskeletal Diseases; Rheumatic Diseases; Arthritis; Osteoarthritis; Necrosis; Osteoarthritis, Hip
• Other Study ID Numbers: R11014-3-D

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No