Proximal Junctional Kyphosis Following Long Instrumented Spinal Fusion: The Effect of Implant Selection

Study Overview
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Brief Summary
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The treatment of adult deformity has improved with the development and use of modern segmental instrumentation, including posterior instrumentation. However, the incidence of proximal junctional kyphosis (PJK) caused by the accelerated degeneration of the joint capsules and smaller articular processes in the proximal junctional region has also been noted. One potential way of decreasing PJK is to decrease the structural rigidity of the construct at the top thereby providing a transition to the non-instrumented spine and allowing for less facet capsule and muscle disruption.

Detailed Description
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While a possible solution to PJK is to reduce structural rigidity at the top of the construct, there is a need to investigate it. In the proposed study, the investigators will compare the rate of proximal junctional kyphosis in patients treated with a stainless steel rod (REVERE Stabilization System) versus those treated with TRANSITION Stabilization System. Patient outcome measures (Scoliosis Research Society (SRS-22), SF12 and ODI) and radiographic measurements (including lumbar lordosis (L1-S1), adjacent segment kyphosis, thoracolumbar kyphosis (T10-L2), sagittal balance, sacral slope, and pelvic incidence) will be analyzed.

Official Title
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Proximal Junctional Kyphosis Following Long Instrumented Spinal Fusion: The Effect of Implant Selection

Conditions
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Kyphosis

Intervention / Treatment
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* Device: Less rigid rod
* Device: Rigid Rod


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patients with degenerative spondylolisthesis with objective evidence of neurologic impairment, kyphosis, and failed previous fusion (pseudoarthrosis) requiring treatment with an instrumented posterior fusion from the thoracolumbar junction (T10-L1) to the sacrum At least 18 years of age and maximum 70 years of age Ability to provide Informed Consent for study participation and patients to return for all follow-up visits Exclusion Criteria: Presence of systemic or localized infection Previous fusion attempt at the involved level(s) More than three previous open, posterior, lumbar spinal surgical procedures at the involved level(s) Trauma at the levels to be fused Previous documentation of osteopenia or osteomalacia Diagnosis of a condition or requires postoperative medication(s), which may interfere with bony/soft tissue healing Presence of a disease entity or condition which totally precludes possibility of bony fusion (e.g. metastatic cancer, HIV, long term use of steroids, etc.) Immunosuppressive disorder Pregnancy History of alcohol and/or drug abuse Any known allergy to a metal alloy Mentally incompetent or prisoner Currently a participant in another study Preoperative structural deformity in the thoracic spine (kyphosis >60 degrees, Coronal curve >40 degrees) Circumferential fusion above L1

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Less rigid rods<br>Titanium rods that have a soft, plastic end | Device: Less rigid rod<br>* Titanium rod with semi rigid end<br>* Other names: TRANSITION;|
| Active Comparator: Rigid Rods<br>Titanium rods | Device: Rigid Rod<br>* Rigid Titanium rods<br>* Other names: REVERE;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evidence of Proximal Junction Kyphosis as determined by radiographic measurements during follow up visits | Radiographs will be taken to measure lumbar lordosis, adjacent segment kyphosis, thoracolumbar kyphosis, sagittal balance, Sacral slope and pelvic incidence. | 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Patient outcome measures | Forms to be completed at follow up visits will include VAS, SRS 22, SF12, ODI, Patient Satisfaction, Work Status Assessment and Odom's criteria. | 2 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Rigid rods, less rigid rods, prevent kyphosis, long constructs