Evaluation of the Trabecular Metal™ Revision Hip Cup Using Bone Mineral Density (DEXA)

The Cleveland Clinic25 enrolled

Overview

In 1997, the FDA approved the use of Trabecular Metal™ (Zimmer, Trabecular Metal Technology, Inc., Parsippany, NJ) for acetabular cups, a porous tantalum structural biomaterial that was developed to address the limitations of other implant materials, with the potential to improve implant fixation. Porous tantalum (80% porosity) offers potentially greater ingrowth and bone graft incorporation, believed to be restricted by the low porosity of other commonly used implants (30%). Additionally, the low modulus of elasticity property (3 MPa) of porous tantalum provides more normal physiological loading conditions which theoretically reduce stress shielding and resultant bone loss surrounding the implant. These properties are much desired advantages for implants used in cementless THA. Various porous tantalum implants have shown favorable clinical results. Unger et al. reported excellent bone graft incorporation of the acetabular component based on serial radiograph data at a minimum 1-year follow-up. Dual-energy X-ray absorptiometry (DEXA) is a well-established method for detecting periprosthetic bone mass changes around the femoral and acetabular THA components. The primary objective of this study is to quantify and compare periprosthetic bone mineral density (BMD) changes in THA revision patients receiving Trabecular Metal™ and metal-backed acetabular components, measured using DEXA scanning techniques. Additionally, this study will analyze and compare clinical outcomes of these patients, based on SF-12v2 and HOOS.

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Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

TRIPLE

Enrollment

Conditions

Eligibility

Sex: ALLMin age: 18 YearsMax age: 85 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Age: 18 - 85 years * Sex: Both male and female will be included. The male-to-female ratio will depend upon the patient population. * Stable Health: At the time of surgery based on physical examination and medical history. * Patient is a revision total hip recipient, which requires a metal-backed hemispherical cup. * Patient or patient's legal representative has signed the Informed Consent form. The patient is capable of making informed decisions regarding his/her healthcare. Exclusion Criteria: * Patients undergoing bilateral surgery or had prior hip arthroplasty on contralateral side less than 6 months from date of surgery. * Patients who do not plan to return to a Cleveland Clinic surgeon for follow-up visits (i.e. out of state/country patients who may choose to follow-up with a different surgeon). * Patients with history of radiation therapy. * Patients with known diagnosis of Brooker grade 3 or 4 HO (heterotopic ossification) in the hip joint region. * Patients with known diagnosis of renal disease. * Patients with known diagnosis of osteoporosis. * Patients with history of steroid use in the hip joint region. * Patients that have had a previous lumbar fusion. * Patients whose surgical reconstruction required a pelvic cage or plate. * Patient was a poor compliance risk - treated for ethanol or drug abuse, physical or mental handicap, etc. * Any female of childbearing potential who is pregnant or is planning on becoming pregnant during the study period (\~2 years postoperative).

Outcomes

Primary Outcomes

Periprosthetic Bone Mineral Density (BMD) of Hip

Quantify and compare periprosthetic bone mineral density (BMD) changes in THA revision patients receiving Trabecular Metal™ and metal-backed acetabular components, measured using DEXA scanning techniques. Region 1 forms the superior-lateral region, Region 2 forms the superior-medial region, and Region 3 forms the inferior-medial region around the acetabular component. For each region, the mean change in BMD was calculated using the following equation described by Wilkinson et al (J Bone Joint Surg Br., 2001): mean percent change in BMD = (BMD1-BMD2) x 2 x 100 / (BMD1 + BMD2). These regions were patient specific and remained the same each time the patient was scanned.

Time frame: 2 years postoperative; measured at 3 months (baseline), 6 months, 1 year, 2 year postoperative

Secondary Outcomes

Functional and General Health Outcome Assessments

Analyze and compare functional and general health outcomes of these patients, based on Hip disability and Osteoarthritis Outcomes Score (HOOS) and 12-item Short Form Health Survey (SF-12v2). All subscale scores are calculated independently and range from 0 to 100, where 100 indicates no problems: * SF-12 Physical Component Summary Subscale (SF12 PCS) assesses physical function, bodily pain, and general health. * SF-12 Mental Component Summary Subscale (SF12 MCS) assesses emotional and mental health. * HOOS Pain assesses pain in the hip * HOOS Symptoms assesses symptoms such as stiffness in the hip * HOOS activities of daily living (HOOS ADL) assesses physical function while performing common daily activities (walking, sitting, standing, etc.) * HOOS sport and recreation (HOOS Sports/Rec) assesses physical function while performing higher-level activities (running, squatting, etc.) * HOOS hip-related quality of life (HOOS QOL) assesses how much the hip impacts life

Time frame: 2 years postoperative; measured preoperatively and 3 months, 6 months, 1 year, 2 year postoperative