Mid- or High-flex Rods Versus Low-flex Rods of SpineShape System IV for Treatment of Degenerative Lumbar Spine Diseases

Dynamic stabilization systems for the lumbar spine are no novelty. The SpineShape System IV builds on the experience of previous systems and attempts to provide additional benefits primarily through three different and relatively elastic rod stiffnesses. 126 subjects with degenerative symptoms in 1 to 2 segments of the lumbar spine L1 to S1 will be recruited. The participants will be randomized in a 1:1:1 ratio to undergo implantation of either the elastic (experimental product group 1), medium (experimental product group 2) or stiff rod (comparison product group).

The aim of the study is to show that the treatment of degenerative lumbar spine with elastic or medium rod variants is not inferior to treatment with hard rods in terms of clinical and safety-related results. This is checked by completing a questionnaire before the surgical procedure and 3 months, 12 months, 24 months and 60 months after the surgical procedure.

Inclusion criteria

• degenerative symptoms in 1 to 2 segments in the lumbar spine L1-S1
• signed informed consent of participant
• confirmation of the participant that the attendance of follow-up visits are intended
• Body-Mass-Index < 32
• Pedicle screw axis distance < 30mm
• one or more of the following indications:

• (dynamic) stenosis in the spinal canal
• neuroforaminal stenosis
• facet joint syndrome / spondylarthrosis
• discopathy (recurrent disc hernia)
• degenerative spondylolisthesis (Meyerding <1)
• instability (hypermobility with antelishtesis, hypomobility with retrolisthesis if decompressed)

Exclusion criteria

• missing bone structure, e.g. due to congenital anomalies or sever anatomical deformities that make anchoring of the implant impossible
• damaged structural tissue, e.g. due to a bone fracture
• application to the thoracic or cervical spine
• pronounced idiopathic scoliosis
• spondylolisthesis > Meyerding grad 1
• isthmic spondolylysis
• bone tumor
• osteochondrosis modic type I, II or III
• osteoporosis, which could impair screw anchoring
• history with third party implants
• patients with an active local or systemic infection
• known allergy to titatnium alloys
• skeleton in growth (epiphyseal joints not closed)
• severe muscular neuronal or vascular disease
• immunosuppresive therapy
• long-term therapy with cortisone
• heavy smokers (regular consumption of more than six cigarettes per day), drug addicts and alcoholics
• chronic pain patients
• incapable of judgment or emergency situation
• implantation during pregnancy