Surgical Treatment of Spinal Deformity With Sagittal Imbalance Using Patient-specific Rods: A Multicenter, Controlled, Double- Blind Randomized Trial: The PROFILE Study

Surgical Treatment of Spinal Deformity With Sagittal Imbalance Using Patient-specific Rods: A Multicenter, Controlled, Double- Blind Randomized Trial: The PROFILE Study

Lumbar degenerative diseases (LDD) are an increasingly common condition affecting millions of patients worldwide. LDD can impact not only function, but can also become markedly disabling and cause severe chronic pain. Recent studies support the idea that analysis of sagittal balance is a crucial keypoint to optimize the management of lumbar degenerative diseases, especially when spinal instrumentation is intended.

The first treatment of these pathologies is a medical treatment (medications, physical therapy and exercise). Surgical treatment is frequently necessary if the symptoms worsen and is generally a posterior spinal fusion with instrumentation (screws, hooks and rods) and bone graft. Basic principle of the surgery is to realign the spine along the rod.

Despite documented techniques for surgical planning, it appears that a significant number of patients are ultimately under-corrected after surgery Realignment failure has not only been associated with poor functional outcome but also major complications, such as pseudoarthrosis and rod breakage, which often results in additional surgical procedures.

From a pragmatic point of view, there are two main reasons for realignment failure: poor surgical planning and poor execution. One of the assumptions is that perioperative manual bending of the rod may not always allow the surgeon to restore the sagittal parameters as intended.

A new concept of patient-specific rod (PSR) is now being proposed by a French manufacturer in order to enable an optimal correction and surgical stabilization of the spine. PSR are designed to fit with the patient's unique sagittal spine profile and with surgeons' surgical planning. However, no relevant clinical data is currently available to support the expected medical benefit of this new technology.

The objective of the study is therefore to carry out a study hypothesizing that the use of PSR could improve the percentage of patients whose sagittal profile is optimally corrected after spinal surgery, as well as the patient's quality of life.

Inclusion Criteria:

• • Adult sagittal deformity of the spine defined as

  • a loss of lumbar lordosis versus the pelvic incidence (LL- PI) outside of the range of ±20°
  • PT>25° or SVA>50mm
  • Patients with functional impairment defined as an Oswestry Disability Index over 40/100
  • Spinal posterior fusion and instrumentation indicated for the patient
  • Surgery indicated for 4 or more lumbar levels: from T12 to S1
  • Patients in whom an optimal correction of the sagittal profile is considered to be feasible according to the following criteria:
  • 10°≤ LL-PI≤10°
  • PT < 20°
  • SVA < 40mm.
  • Patients older or equal to 18 years
  • Patients able to sign an informed consent form
  • Patients able to fill out a self-administered questionnaire
  • Patient has to be the beneficiary of the social security system (order n° 2006-477 from April 26th 2006);

Exclusion Criteria:

• • Coronal deformity without sagittal imbalance

  • Patients who required a vertebrectomy
  • Patients who do not required a bone graft or a bone fusion
  • Patient with congenital metabolic bone abnormalities
  • Patient with recent (less than 1month) lumbar vertebrae fracture
  • Patients with insufficient tissue coverage of the surgical site, an insufficient bone quality and quantity.
  • History of an osteoporotic fracture, joint disease with fast evolution, bone resorption, osteopenia
  • Pathologic obesity (BMI > 40)
  • Patients with active or chronic infection, fever or leukocytosis.
  • Suspected or known allergy or intolerance to the medical device used and requesting a combination of different metals.
  • Patient with a medical contraindication to the material used or for which the use of the device could interfere with anatomical structures or expected physiological function.
  • Patients with ongoing treatment of any cancer or history of any cancer of less than 5 years
  • Chronic inflammatory disease
  • Women who are pregnant
  • Patients unable to understand the purpose of the trial or refusing to follow post-surgery instructions.
  • Participation to another trial
  • Patients under legal protection