Radiographic and Clinical Evaluation of Surgical Treatment for Cervical Deformity: A Multi-Center Study 2.0

Multi-center, prospective, non-randomized study to evaluate outcomes of surgically treated patients with adult cervical spinal deformity.

Adult cervical deformity (ACD) is an uncommon but potentially severely debilitating condition with a broad range of causes that include but are not limited to spondylosis, inflammatory arthropathy, trauma, infection, iatrogenic, neoplastic, congenital, and neuromuscular processes. In general, sagittal plane deformities typically produce kyphosis, and coronal plane deformities result in scoliosis. Cervical kyphotic deformities are most commonly encountered in the setting of prior surgical destabilization, while cervical scoliosis is most commonly associated with congenital and neuromuscular conditions.

Cervical kyphosis may be progressive and can result in neurological symptoms, including myelopathy. The most severe forms, such as those associated with spondylotic arthropathies, can produce "chin-on-chest" deformity, which can compromise horizontal gaze, swallowing, and breathing. Even in the absence of these conditions, cervical deformity is often associated with pain and functional disability. For adult thoracolumbar deformities, substantial efforts have been made to characterize clinical presentations, develop standardized classification systems, define optimal treatment approaches, describes operative complication rates, and to present structured clinical outcomes. However, despite the potential for profound impact of cervical deformity on function and health-related quality of life, there remains a remarkable paucity of high-quality studies that address these complex conditions.

Health professionals providing nonoperative and surgical care for these patients are left to make important treatment decisions based on a combination of personal experience, anecdotal experience of colleagues and experts, and relatively small, often single-surgeon or single-center, retrospective case reports or case series in the literature. Recent systematic reviews have high-lighted the lack of studies relevant to cervical deformity and have failed to identify any prospective studies.

The International Spine Study Group (ISSG) consists of orthopedic and neurological spine surgeons with a practice emphasis on spinal deformity patients. These surgeons, from 12 busy surgical centers, meet regularly to design and perform clinical research focused on spinal deformity, including successful prospective enrollment of more than 1,000 adult thoracolumbar deformity patients into the ISSG database. This group has a proven track record and regularly presents a substantial number of abstracts to the major spine meetings and has an extensive publication record.

The ISSG members have currently enrolled more than 150 patients into the first generation prospective cervical deformity database and have produced approximately 50 abstracts and more than 25 manuscripts to date with the resulting data. The group has learned extensively from this first-generation database, but there is much yet to learn, as the literature remains relatively sparse on the topic of adult cervical deformity. Based on what we have learned from the first generation database; we have substantially modified the inclusion criteria for this second generation database. In addition, several new outcomes measures and functional assessments will be collected at baseline and follow-up intervals as part of this current proposal.

The resources of the ISSG offer an unprecedented opportunity to create a prospectively collected multicenter database of cervical deformity patients that includes standardized health-related quality of life measures at baseline and regular follow-up, clinical and surgical parameters, and complications. The database and questionnaires have been carefully redesigned based on what we have learned in order to better collect data that will help to clarify many of the unresolved issues that are important for the care of cervical deformity patients. This project has substantial potential to significantly impact the field of cervical deformity and the care of deformity patients beyond what we have already been able to accomplish based on the first generation cervical deformity database. Herein we propose the second iteration for this project that promises to further advance our evolving understanding of these complex deformities.

Eligibility Criteria:
Inclusion Criteria:

* ≥18 years old at time of treatment
* Diagnosis of cervical deformity- must meet one or more of the following criteria:

  * C2-C7 sagittal kyphosis (Cobb \> 15 degrees)
  * T1S-CL \> 35o
  * Segmental cervical kyphosis \> 10 degrees between any 2 vertebra between C2-T1 or \> 15 degrees across any 3 vertebra between C2-T1
  * Cervical scoliosis \> 10 degrees (Cobb angle must include end vertebra within the cervical spine)
  * C2-C7 SVA \> 4cm
  * McGregor's slope \> 20 degrees or CBVA \> 25 degrees
* Plan for surgical correction of cervical deformity in the next 6 months
* Willing to provide consent and complete study forms at baseline and follow-up intervals

Exclusion Criteria:

* Active spine tumor or infection
* Deformity due to acute trauma
* Unwilling to provide consent or to complete study forms
* Prisoner
* Pregnant or immediate plans to get pregnant