Osteoarthritis, Hip
Conditions
Keywords
Metal ion concentration, Total hip arthroplasty, Hip resurfacing
Brief summary
The investigators aimed to investigate the possible differences in metal ion concentrations in patients following one of two types of metal-on-metal articulating hip prosthesis regarding chromium and cobalt concentration, radiological findings, patient reported outcome measures and rate of revision at 5-years follow up.
Detailed description
The metal-on-metal large-diameter-head (MoM-LDH) hip replacements increased in popularity during the start of the 21st century. Subsequently reports raised concerns regarding adverse reactions due to elevated chromium (Cr) and cobalt (Co) concentrations as well as high rates of other complications and revisions. This was a single center parallel-group randomized controlled trial. The primary outcome was to compare Cr and Co concentrations at 5-years follow up following MoM-LDH total hip arthroplasty (MoM-LDH-THA) or MoM-LDH hip resurfacing (MoM-LDH-HR). Secondary outcomes were radiological findings, patient reported outcome measures and revision rate at 5-years follow up. The study was prematurely terminated in 2012 due to alerts and safety communications from the Danish national regulatory agency regarding early failure rates and high incidence of ARMD in patients with MoM hip implants \[13\]. At that time the study population consisted of 75 patients out of 200 planned for inclusion.
Interventions
DEVICEMagnum, Zimmer Biomet, Warsaw, IN
DEVICERecap, Zimmer Biomet, Warsaw, IN
Sponsors
Hvidovre University Hospital
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Caregiver, Outcomes Assessor)
Masking description
Both the care provider and patient were blinded until day of surgery. The laboratory analyzing blood metal concentrations were blinded to treatment allocation throughout the study.
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
* Primary or secondary hip osteoarthritis eligible for hip replacement surgery * Able to give informed consent * Able to complete follow up consultations
Exclusion criteria
* Earlier or present infection of the hip * Severe systemic or metabolic disease leading to weakening of the bone * Severe congenital hip dysplasia * Osteoporosis and/or renal disease
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Metal Ion Concentrations in Blood | at 5 years follow up | Chromium and cobalt concentrations in whole blood |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Harris Hip Score | at 5 years follow up | Harris Hip Score (0-100, higher values meaning better outcome) |
| SF-36 | at 5 years follow up | Short Form 36 Health Survey Questionnaire (SF-36) (0-100, higher values meaning better outcome) |
| Number of Patients Undergoing Revision | at 5 years follow up | Rate of revision during the follow-up period, calculated as number of revisions (numerator) out of the total number of patients starting the study (denominator) |
Participant flow
Recruitment details
The study was conducted in a tertiary health care center in Copenhagen, Denmark from November 2006 to January 2012. 5-years follow up consultations were conducted from 2011 to 2017.
Participants by arm
| Arm | Count |
|---|---|
| Magnum A metal-on-metal large diameter head total hip arthroplasty
Magnum, Zimmer Biomet, Warsaw, IN | 39 |
| Recap A metal-on-metal hip resurfacing arthroplasty
Recap, Zimmer Biomet, Warsaw, IN | 36 |
| Total | 75 |
Baseline characteristics
| Characteristic | Magnum | Recap | Total |
|---|---|---|---|
| Age, Continuous | 61.9 years | 59.4 years | 60.8 years |
| BMI | 28.4 kg/m^2 | 27.45 kg/m^2 | 27.9 kg/m^2 |
| Region of Enrollment Denmark | 39 Participants | 36 Participants | 75 Participants |
| Sex: Female, Male Female | 13 Participants | 10 Participants | 23 Participants |
| Sex: Female, Male Male | 26 Participants | 26 Participants | 52 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 2 / 39 | 0 / 36 |
| other Total, other adverse events | 0 / 39 | 0 / 36 |
| serious Total, serious adverse events | 0 / 39 | 6 / 36 |
Outcome results
Primary
Metal Ion Concentrations in Blood
Chromium and cobalt concentrations in whole blood
Time frame: at 5 years follow up
Population: The discrepancy between numbers of patients analysed and the numbers presented in Participant flow is due to patients who had bilateral MoM hip replacement at the 5-year follow-up were excluded in addition to those lost to follow up, who had revision surgery or died before 5-years follow up.
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| Magnum | Metal Ion Concentrations in Blood | Chromium | 1.36 micrograms/liter |
| Magnum | Metal Ion Concentrations in Blood | Cobalt | 1.67 micrograms/liter |
| Recap | Metal Ion Concentrations in Blood | Chromium | 1.21 micrograms/liter |
| Recap | Metal Ion Concentrations in Blood | Cobalt | 0.92 micrograms/liter |
Secondary
Harris Hip Score
Harris Hip Score (0-100, higher values meaning better outcome)
Time frame: at 5 years follow up
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Magnum | Harris Hip Score | 100 units on a scale |
| Recap | Harris Hip Score | 100 units on a scale |
Secondary
Number of Patients Undergoing Revision
Rate of revision during the follow-up period, calculated as number of revisions (numerator) out of the total number of patients starting the study (denominator)
Time frame: at 5 years follow up
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Magnum | Number of Patients Undergoing Revision | 0 Participants |
| Recap | Number of Patients Undergoing Revision | 6 Participants |
Secondary
SF-36
Short Form 36 Health Survey Questionnaire (SF-36) (0-100, higher values meaning better outcome)
Time frame: at 5 years follow up
Population: The total number of patients analyzed is different from the total number of patients who completed the study, since some patients had missing data for this questionnaire.
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| Magnum | SF-36 | Vitality | 77.5 score on a scale |
| Magnum | SF-36 | Social function | 100 score on a scale |
| Magnum | SF-36 | Physical function | 90 score on a scale |
| Magnum | SF-36 | Physical restriction | 100 score on a scale |
| Magnum | SF-36 | Bodily pain | 92 score on a scale |
| Magnum | SF-36 | General health | 74.5 score on a scale |
| Magnum | SF-36 | Emotional restriction | 100 score on a scale |
| Magnum | SF-36 | Mental Health | 92 score on a scale |
| Recap | SF-36 | Mental Health | 88 score on a scale |
| Recap | SF-36 | Vitality | 75 score on a scale |
| Recap | SF-36 | Bodily pain | 84 score on a scale |
| Recap | SF-36 | Social function | 100 score on a scale |
| Recap | SF-36 | Emotional restriction | 100 score on a scale |
| Recap | SF-36 | Physical function | 90 score on a scale |
| Recap | SF-36 | General health | 79.5 score on a scale |
| Recap | SF-36 | Physical restriction | 100 score on a scale |