[Interspinous implant "InSWing®" for the lumbar spine].

OBJECTIVE

Interspinous stabilization and, if desired, posterior spreading of the functional spinal unit (FSU).

INDICATIONS

Symptomatic spinal stenosis with or without concomitant degeneration of the lumbar spine above L5/S1. Relative Indications: Mass prolapse of the lumbar intervertebral disc, for stabilization of the FSU together with removal of the prolapse/sequester. Symptomatic recurrent stenosis after stand-alone decompression surgery, for prevention of re-stenosis in the same segment. Topping-off during fusion surgery for a more physiological introduction of loads into the adjacent segment.

CONTRAINDICATIONS

Lack of operability and sustainance of anaesthesia of the patient - this may also include severe psychiatric/psychological disorders, adipositas permagna, and severe osteoporosis. Insufficient posterior structures such as spondylolysis, more than first degree spondylolisthesis. Severe bony stenosis (if implant is used without additional decompressive surgery!). Preoperatively known, intraoperatively discovered and/or induced instability of the FSU. Too close distance of the implant towards dural sac, particularly in case of dural tears, fistulae or overt inflammation.

SURGICAL TECHNIQUE

Interspinous unfolding of the PEEK-based implant via small midline incision, from one deliberately chosen access side with preservation of the supraspinous ligament and with optional tension-band fixation around both spinous processes in contact with the implant.

POSTOPERATIVE MANAGEMENT

6 weeks restriction of lifting plus advocation of isometric physiotherapy without large motion amplitudes for warranting of a stable encapsulation of the implant via ligamentary remodelling. Sports activities not before that time period. The author prefers administration of a light brace for that time, yet the latter does not seem mandatory.

RESULTS

Proven safe, unilateral, little invasive, and versatile procedure with advantages over well-established other market-available implants.