Degenerative Spondylolisthesis, Pseudoarthrosis
Conditions
Keywords
Dynesys Dynamic Stabilization System, Spondylolithesis, pseudoarthrosis, neurologic impairment, failed fusion
Brief summary
The purpose of this study is to assess the safety and fusion rates following posterior lateral fusion with the Dynesys Spinal System used as an adjunct to fusion and compare to literature control.
Detailed description
Study is meant to assess the safety and fusion rates following posterior lateral fusion with the Dynesys Spinal System.
Interventions
DEVICEDynesys Spinal System
Dynesys Spinal System will be used for all subjects
Sponsors
Zimmer Biomet
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
20 Years to 80 Years
Healthy volunteers
No
Inclusion criteria
1. Skeletally mature between the ages of 20-80 2. Candidate for posterior lateral fusion between T1-S1 with autograft 3. Degenerative spondylolisthesis with evidence of neurologic impairment or failed previous fusion (pseudoarthrosis) 4. Symptoms of leg and/or back pain 5. Non-responsive to conservative/non-surgical treatment for at least three (3) months 6. Must be willing and able to comply with study requirements; including complete necessary study paperwork and return for required follow-up visits
Exclusion criteria
1. Active systemic or local infection 2. Obesity 3. Use of interbody device 4. Pregnancy 5. Mental illness 6. Incarceration 7. Alcohol or drug abuse 8. Severe osteoporosis or osteopenia 9. Use in the cervical spine 10. Sensitivities/allergy to metals, polymers, polyethylene, polycarbonate urethane and polyethylene terephthalate 11. Soft tissue deficit not allowing sound closure 12. Any medical or physical condition that would preclude the potential benefit of spinal implant surgery 13. Congenital abnormalities, tumors or other conditions that would prevent secure component fixation that has the potential to decrease the useful life of the device 14. Active malignancy or other significant medical comorbidities 15. Any medical or mental condition which would put the patient at high risk due to the severity of surgery 16. Inadequate pedicles of the thoracic, lumbar and sacral vertebrae 17. Patient unwilling or unable to follow postoperative instructions
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Fusion Rates | 24 months post surgery date | Fusion was defined by meeting three criteria: * rotation \< 5° between motion segments on flexion-extension radiographs * translation \< 3 mm between motion segments on flexion-extension radiographs * presence of bridging bone. Fusion assessment for each patient was categorized as one of the four defined outcomes: fused, not fused, partial fusion, or UA (unable to assess). Efficacy was confirmed by the achievement of fusion in the experimental group when compared to the rate established in a literature control. |
Countries
United States
Participant flow
Pre-assignment details
In the time between signing consent and application of treatment 13 subjects were discontinued. Out of 153 enrolled there were: 5- screen failures; 1- withdraw consent; 5- insurance denials; 2- Removed by investigator.
Participants by arm
| Arm | Count |
|---|---|
| Dynesys System Dynesys Spinal System will be used for all subjects | 139 |
| Total | 139 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Overall Study | Death | 2 |
| Overall Study | Determined not eligible by AEAC | 1 |
| Overall Study | Early Termination of Study | 52 |
| Overall Study | Explanted | 2 |
| Overall Study | Lost to Follow-up | 5 |
| Overall Study | Missed Visit | 2 |
| Overall Study | Physician Decision | 1 |
| Overall Study | Site Closure | 4 |
| Overall Study | Withdrawal by Subject | 5 |
Baseline characteristics
| Characteristic | Dynesys System | — |
|---|---|---|
| Age, Continuous | 63.9 years STANDARD_DEVIATION 9.9 | — |
| BMI | 30 (kg/mg^2) STANDARD_DEVIATION 5.4 | — |
| Height | 65.7 inches STANDARD_DEVIATION 3.7 | — |
| Race and Ethnicity Not Collected | — | — Participants |
| Sex: Female, Male Female | 88 Participants | — |
| Sex: Female, Male Male | 51 Participants | — |
| Weight | 184.6 pounds STANDARD_DEVIATION 39.6 | — |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 2 / 139 |
| other Total, other adverse events | 71 / 139 |
| serious Total, serious adverse events | 33 / 139 |
Outcome results
Primary
Fusion Rates
Fusion was defined by meeting three criteria: * rotation \< 5° between motion segments on flexion-extension radiographs * translation \< 3 mm between motion segments on flexion-extension radiographs * presence of bridging bone. Fusion assessment for each patient was categorized as one of the four defined outcomes: fused, not fused, partial fusion, or UA (unable to assess). Efficacy was confirmed by the achievement of fusion in the experimental group when compared to the rate established in a literature control.
Time frame: 24 months post surgery date
Population: Sixty-six (66) out of the original 140 implanted subjects completed their 24 month follow up. Sixty-one (61) subjects completed 24month radiograph for analysis of the primary end point.
| Arm | Measure | Category | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Dynesys System | Fusion Rates | Proportion fused | 33 Participants |
| Dynesys System | Fusion Rates | Proportion not fused | 19 Participants |
| Dynesys System | Fusion Rates | Proportion with Partial Fusion | 5 Participants |
| Dynesys System | Fusion Rates | Proportion unable to assess | 4 Participants |