Wallis Interspinous Dynamic Stability System for Lumbar Disc Herniation: a Prospective Study
Condition: Lumbar Disc Herniation
MeSH terms: Intervertebral Disc Displacement; Hernia
Study type: Interventional
Phase: Phase 3

Summary: 
      Lumbar disc herniation is usually treated by discectomy alone. Nonfusion system such as
      Wallis interspinous implants have also been successfully used in disc degenerative diseases.
      However, the superiority of a discectomy with Wallis in comparison to a discectomy alone for
      primary lumbar disc herniation has yet to be determined.The aim of our study is to
      investigate whether lumbar discectomy combined with the Wallis device provides better
      radiographic and clinical short-term outcome than posterior lumbar discectomy alone.
    

Detailed description: 
      The most commonly used therapy for lumbar disc herniation (LDH) are partial discectomy or
      discectomy with fusion if there was an additional mechanical disorder in the underlying
      functional spinal unit. However, the problems associated with discectomy are intervertebral
      disc height loss and the segmental instability, thought to be a risk for failed back surgery
      syndrome or recurrence lumbar disc herniation. Fusion has also been criticised for its side
      effects of adjacent segment degeneration(ASD), pseudarthrosis and bone-graft morbidity. To
      prevent such complications , a new family of dynamic implants have been established. Wallis
      interspinous implant (Abbott Laboratories, Bordeaux, France) , invented by J. Senegas, is one
      of them. It consisted of a interspinous blocker made out of polyetheretherketone (PEEK) to
      limit extension and two dacron tapes around the spinous processes in order to secure the
      implant and limit flexion. The aim of using this device is to unload the facet joints, to
      restore foraminal height and to provide sufficient stability especially in extension but
      still allow motion in the treated segment. Previous clinical trials and biomechanical studies
      are promising, however, the superiority of a discectomy with Wallis in comparison to a
      discectomy alone for primary lumbar disc herniation has yet to be determined. The purpose of
      this prospective controlled study was to evaluate the clinical effect of lumbar discectomy
      combined with Wallis interspinous device, comparing with posterior lumbar discectomy alone.
      Our hypothesis was that the use of the Wallis device would have better clinical and
      radiological outcomes than lumbar discectomy alone.
    

Intervention name(s): Lumbar discectomy; Lumbar discectomy combined with Wallis interspinous dynamic stability system
Intervention type(s): Procedure; Procedure
Intervention description(s): All the patients were in prone positions on the operation table and received general anesthesia. A midline incision was made and paravertebral muscles were dissected unilaterally. Disc excision and nerve root decompression were initially accomplished through a unilateral transflaval approach. Then the wound was closed with a suction drain.; The Wallis interspinous implant is placed after a lumbar discectomy. Interspinal ligaments of operated segment were removed and supraspinal ligament were retained. And then the proper size of Wallis implant was mounted underneath the supraspinous ligament and secured to the spine with the attached Dacron bands,above and below the corresponding spinous processes.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Lumbar disc herniation; Wallis interspinous implants; lumbar discectomy; interspinous dynamic stability system