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

Study Overview
=================
Brief Summary
-----------------
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).

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

Conditions
-----------------
Primary and Secondary Coxarthrosis, Dysplasia Coxarthrosis, Post-traumatic Necrosis of the Femoral Head

Intervention / Treatment
-----------------
* Device: Total Hip Arthroplasty


Participation Criteria
=================
Eligibility Criteria
-----------------
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.

Ages Eligible for Study
-----------------
Minimum Age: 30 Years
Maximum Age: 65 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| NANOS<br>NANOS™ Neck Preserving Hip Stem | Device: Total Hip Arthroplasty<br> <br> |

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 | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Nanos, THA, MBRSA