Trial Outcomes & Findings for Marathon and Enduron Polyethylene at Long-Term Follow-up (NCT NCT02508428)

NCT ID: NCT02508428

Last Updated: 2020-12-01

Results Overview

Kaplan-Meier survivorship was calculated using revision for wear/osteolysis as an endpoint.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

230 participants

Primary outcome timeframe

At 15-year follow-up and every 5 years after from the date of the patient's primary total hip arthroplasty for the duration of the patient's life or until revision of the polyethylene liner (estimated to be 25 years)

Results posted on

2020-12-01

Participant Flow

Beginning in January of 1999 and continuing over an 18-month period, patients at our institution were enrolled in a prospective, randomized, Institutional Review Board approved study to compare the outcome of THA using XLPE or CPE liners.

All patients undergoing primary THA were eligible to participate in this study. A total of 226 patients (236 hips) consented to participate. Six patients (6 hips) were excluded at the time of their surgery because they were not implanted with the study components for reasons related to intra-operative hip stability.

Unit of analysis: hips

Participant milestones

Participant milestones
Measure
Crosslinked Marathon Polyethylene
Total Hip Replacement using a crosslinked Marathon polyethylene liner
Standard Enduron Polyethylene
Total Hip Replacement using a noncrosslinked Enduron polyethylene liner
Overall Study
STARTED
114 116
111 114
Overall Study
COMPLETED
62 64
44 46
Overall Study
NOT COMPLETED
52 52
67 68

Reasons for withdrawal

Reasons for withdrawal
Measure
Crosslinked Marathon Polyethylene
Total Hip Replacement using a crosslinked Marathon polyethylene liner
Standard Enduron Polyethylene
Total Hip Replacement using a noncrosslinked Enduron polyethylene liner
Overall Study
Death
32
33
Overall Study
Liner revised
3
19
Overall Study
Incomplete follow-up
17
15

Baseline Characteristics

Race and Ethnicity were not collected from any participant.

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Crosslinked Marathon Polyethylene
n=116 hips
Total Hip Replacement using a crosslinked Marathon polyethylene liner
Non-crosslinked Enduron Polyethylene
n=114 hips
Total Hip Replacement using a noncrosslinked Enduron polyethylene liner
Total
n=230 hips
Total of all reporting groups
Age, Continuous
62.5 years
STANDARD_DEVIATION 10.6 • n=116 hips
62.0 years
STANDARD_DEVIATION 11.1 • n=114 hips
62.3 years
STANDARD_DEVIATION 10.8 • n=230 hips
Sex: Female, Male
Female
65 hips
n=116 hips
57 hips
n=114 hips
122 hips
n=230 hips
Sex: Female, Male
Male
51 hips
n=116 hips
57 hips
n=114 hips
108 hips
n=230 hips
Race and Ethnicity Not Collected
0 Participants
Race and Ethnicity were not collected from any participant.
Weight
186 pounds
STANDARD_DEVIATION 47 • n=116 hips
180 pounds
STANDARD_DEVIATION 40 • n=114 hips
183 pounds
STANDARD_DEVIATION 43 • n=230 hips
Body Mass Index (BMI)
28.6 kilograms per square meter (kg/m^2)
STANDARD_DEVIATION 5.5 • n=116 hips
27.9 kilograms per square meter (kg/m^2)
STANDARD_DEVIATION 5.1 • n=114 hips
28.2 kilograms per square meter (kg/m^2)
STANDARD_DEVIATION 5.3 • n=230 hips

PRIMARY outcome

Timeframe: At 15-year follow-up and every 5 years after from the date of the patient's primary total hip arthroplasty for the duration of the patient's life or until revision of the polyethylene liner (estimated to be 25 years)

Population: All 230 total hip replacements randomized to crosslinked Marathon or non-crosslinked Enduron liners.

Kaplan-Meier survivorship was calculated using revision for wear/osteolysis as an endpoint.

Outcome measures

Outcome measures
Measure
Crosslinked Marathon Polyethylene
n=116 hips
Total Hip Replacement using a crosslinked Marathon polyethylene liner
Non-crosslinked Enduron Polyethylene
n=114 hips
Total Hip Replacement using a noncrosslinked Enduron polyethylene liner
Percentage of Hips Surviving at 15 Years
100 percentage of hips surviving at 15-years
Interval 100.0 to 100.0
86 percentage of hips surviving at 15-years
Interval 78.0 to 93.0

SECONDARY outcome

Timeframe: At minimum 14-year radiographic follow-up and every 5 years after from the date of the patient's primary total hip arthroplasty for the duration of the patient's life or until revision of the polyethylene liner (estimated to be 25 years)

Population: Hips with at least 3 serial anteroposterior pelvic radiographs that were revised or had minimum 14-year radiographic follow-up.

A single reviewer, blinded to the type of polyethylene liner, evaluated femoral head penetration among all hips using serial anteroposterior pelvic radiographs. Two-dimensional head penetration was determined for each follow-up radiograph using Hip Suite Analysis version 8.0 with elliptical correction, a validated, computer-assisted technique. A linear wear rate was evaluated for each hip that had a minimum of three follow-up radiographs using a least-squares linear regression to calculate the slope of the best-fit line for the wear vector magnitude versus time in situ data. The slope from this regression represented the steady-state linear wear rate. The steady-state linear wear rate data from all hips in a group was used to compute a mean polyethylene wear value.

Outcome measures

Outcome measures
Measure
Crosslinked Marathon Polyethylene
n=46 hips
Total Hip Replacement using a crosslinked Marathon polyethylene liner
Non-crosslinked Enduron Polyethylene
n=56 hips
Total Hip Replacement using a noncrosslinked Enduron polyethylene liner
Polyethylene Wear
0.03 mm/yr
Standard Deviation 0.05
0.25 mm/yr
Standard Deviation 0.16

SECONDARY outcome

Timeframe: At minimum 14-year radiographic follow-up and every 5 years after from the date of the patient's primary total hip arthroplasty for the duration of the patient's life or until revision of the polyethylene liner (estimated to be 25 years)

Population: Unrevised hips that had minimum 14-year radiographic follow-up and revised hips that had a pre-revision radiograph available for analysis.

The incidence of clinically important osteolysis is based on the number of unrevised THAs (total hip arthroplasties) with at least 1.5 square centimeters of pelvic and/or femoral osteolysis. Osteolysis was defined as an area of localized loss of trabecular bone or cortical erosion that was not apparent on the pre-operative or immediate postoperative radiograph. To obtain lesion sizes, the defects were outlined on the anteroposterior pelvic and lateral radiographs. The area of the osteolysis was measured using Martell's Hip Analysis Suite software. Lesions were considered clinically important if the total area of osteolysis around a hip replacement was at least 1.5 square centimeters on either the AP or lateral view.

Outcome measures

Outcome measures
Measure
Crosslinked Marathon Polyethylene
n=49 hips
Total Hip Replacement using a crosslinked Marathon polyethylene liner
Non-crosslinked Enduron Polyethylene
n=58 hips
Total Hip Replacement using a noncrosslinked Enduron polyethylene liner
Incidence of Clinically Important Osteolysis Among Unrevised THAs
1 hips
28 hips

SECONDARY outcome

Timeframe: At minimum 14-year follow-up and every 5 years after from the date of the patient's primary total hip arthroplasty for the duration of the patient's life or until revision of the polyethylene liner (estimated to be 25 years)

Population: All patients with minimum 14-year follow-up who responded to the question, "Are you satisfied with the results of your hip operation?"

Patient satisfaction was quantified by asking participants to respond "yes" or "no" to the question, "Are you satisfied with the results of your hip operation?" Because some patients had both of their hips included in the study, these patients responded to the question, "Are you satisfied with the results of your hip operation?" for their right and left hips. As a consequence, the "Units Analyzed" is reported as hips while the "Number of Participants Analyzed" reflects the number of patients.

Outcome measures

Outcome measures
Measure
Crosslinked Marathon Polyethylene
n=53 hips
Total Hip Replacement using a crosslinked Marathon polyethylene liner
Non-crosslinked Enduron Polyethylene
n=49 hips
Total Hip Replacement using a noncrosslinked Enduron polyethylene liner
Patients Who Answered "Yes" to the Question, "Are You Satisfied With the Results of Your Hip Operation?"
53 hips
48 hips

SECONDARY outcome

Timeframe: At minimum 14-year follow-up and every 5 years after from the date of the patient's primary total hip arthroplasty for the duration of the patient's life or until revision of the polyethylene liner (estimated to be 25 years)

Population: All hip replacements with minimum 14-year follow-up that had data to compute a Harris Hip Score.

The Harris Hip Score measures outcome after hip replacement and is based on a scale from 0 (worst) to 100 (best). The score includes assessments of pain, functional ability, deformity and range of motion.

Outcome measures

Outcome measures
Measure
Crosslinked Marathon Polyethylene
n=37 hips
Total Hip Replacement using a crosslinked Marathon polyethylene liner
Non-crosslinked Enduron Polyethylene
n=26 hips
Total Hip Replacement using a noncrosslinked Enduron polyethylene liner
Harris Hip Score
96 units on a scale
Interval 76.0 to 98.0
92 units on a scale
Interval 74.0 to 95.0

Adverse Events

Crosslinked Marathon Polyethylene

Serious events: 4 serious events
Other events: 0 other events
Deaths: 32 deaths

Non-crosslinked Enduron Polyethylene

Serious events: 19 serious events
Other events: 0 other events
Deaths: 33 deaths

Serious adverse events

Serious adverse events
Measure
Crosslinked Marathon Polyethylene
n=116 participants at risk
Total Hip Replacement using a crosslinked Marathon polyethylene liner
Non-crosslinked Enduron Polyethylene
n=114 participants at risk
Total Hip Replacement using a noncrosslinked Enduron polyethylene liner
Musculoskeletal and connective tissue disorders
Wear/Osteolysis without fracture
0.00%
0/116 • Adverse event data was collected from date of surgery up to 17 years after surgery.
Reoperations were evaluated by reviewing medical records and asking patients if they had any additional surgery on their hip. Please note that adverse events are reported based on the number of hips enrolled in the study, not the number of patients. Ten patients had both of their hips included in the study including two who had both hips randomized to Marathon, three who had both hips randomized to Enduron and five who had one hip randomized to Marathon and the other randomized to Enduron.
8.8%
10/114 • Number of events 10 • Adverse event data was collected from date of surgery up to 17 years after surgery.
Reoperations were evaluated by reviewing medical records and asking patients if they had any additional surgery on their hip. Please note that adverse events are reported based on the number of hips enrolled in the study, not the number of patients. Ten patients had both of their hips included in the study including two who had both hips randomized to Marathon, three who had both hips randomized to Enduron and five who had one hip randomized to Marathon and the other randomized to Enduron.
Musculoskeletal and connective tissue disorders
Recurrent Dislocation
2.6%
3/116 • Number of events 3 • Adverse event data was collected from date of surgery up to 17 years after surgery.
Reoperations were evaluated by reviewing medical records and asking patients if they had any additional surgery on their hip. Please note that adverse events are reported based on the number of hips enrolled in the study, not the number of patients. Ten patients had both of their hips included in the study including two who had both hips randomized to Marathon, three who had both hips randomized to Enduron and five who had one hip randomized to Marathon and the other randomized to Enduron.
1.8%
2/114 • Number of events 2 • Adverse event data was collected from date of surgery up to 17 years after surgery.
Reoperations were evaluated by reviewing medical records and asking patients if they had any additional surgery on their hip. Please note that adverse events are reported based on the number of hips enrolled in the study, not the number of patients. Ten patients had both of their hips included in the study including two who had both hips randomized to Marathon, three who had both hips randomized to Enduron and five who had one hip randomized to Marathon and the other randomized to Enduron.
Musculoskeletal and connective tissue disorders
Wear/Osteolysis with Fracture
0.00%
0/116 • Adverse event data was collected from date of surgery up to 17 years after surgery.
Reoperations were evaluated by reviewing medical records and asking patients if they had any additional surgery on their hip. Please note that adverse events are reported based on the number of hips enrolled in the study, not the number of patients. Ten patients had both of their hips included in the study including two who had both hips randomized to Marathon, three who had both hips randomized to Enduron and five who had one hip randomized to Marathon and the other randomized to Enduron.
6.1%
7/114 • Number of events 7 • Adverse event data was collected from date of surgery up to 17 years after surgery.
Reoperations were evaluated by reviewing medical records and asking patients if they had any additional surgery on their hip. Please note that adverse events are reported based on the number of hips enrolled in the study, not the number of patients. Ten patients had both of their hips included in the study including two who had both hips randomized to Marathon, three who had both hips randomized to Enduron and five who had one hip randomized to Marathon and the other randomized to Enduron.
Musculoskeletal and connective tissue disorders
Open reduction of dislocation
0.86%
1/116 • Number of events 1 • Adverse event data was collected from date of surgery up to 17 years after surgery.
Reoperations were evaluated by reviewing medical records and asking patients if they had any additional surgery on their hip. Please note that adverse events are reported based on the number of hips enrolled in the study, not the number of patients. Ten patients had both of their hips included in the study including two who had both hips randomized to Marathon, three who had both hips randomized to Enduron and five who had one hip randomized to Marathon and the other randomized to Enduron.
0.00%
0/114 • Adverse event data was collected from date of surgery up to 17 years after surgery.
Reoperations were evaluated by reviewing medical records and asking patients if they had any additional surgery on their hip. Please note that adverse events are reported based on the number of hips enrolled in the study, not the number of patients. Ten patients had both of their hips included in the study including two who had both hips randomized to Marathon, three who had both hips randomized to Enduron and five who had one hip randomized to Marathon and the other randomized to Enduron.

Other adverse events

Adverse event data not reported

Additional Information

C. Anderson Engh, Jr., MD

Anderson Orthopaedic Research Institute

Phone: 703-619-4411

Results disclosure agreements

  • Principal investigator is a sponsor employee Materials should be submitted to the sponsor for review at least thirty days before they are due to be submitted for publication. The sponsor will inform the authors of any changes deemed necessary to preserve confidentiality, protect intellectual property or ensure scientific accuracy and the authors agree to make these changes before submission.
  • Publication restrictions are in place

Restriction type: OTHER