Failed Fusion Surgery & Nerve Damage


Clinical Key Points

A patient with screws misplaced during fusion surgery and impinging upon the local nerves, HIV and severe back and leg pain.

History & Prior Treatment

Patrick first developed back pain about ten years ago with extension into the right buttock and a requirement to use a walking stick in 2003. The intensity increased in 2004 with radiation into the right knee and his walking duration was limited to 2 - 3 minutes. At that time he tried for NHS funding to receive treatment at the Spinal Foundation but was turned down upon the advice of local consultants. He underwent a Dynesis flexible fusion in London from L4-S1 but the right L5 & S1 pedicle screws were misplaced and impinged upon the nerves. After a week of agonising pain alignment was revised. Since that time he has been suffering with constant pain on the right-hand side radiating into the right buttock with associated pins and needles radiating to the right great and second toe with hyposensitivity on the dorsum of the foot. He described these symptoms as akin to putting his foot in acid and then pulling a sock over the foot. Since the time of his operation he has had difficulty in moving the toes and pulling up and pressing down with both feet. His walking duration was 3 minutes on the flat, 2 minutes on an incline with a restart time of 1 minute and a post activity penalty of several hours. Static standing was limited to seconds and sitting duration limited to 10 minutes.

Distribution of Symptoms

His pain diagram revealed stabbing pain in the lower lumbar spine with aching in the right paravertebral gutter and groins with stabbing into both buttocks and aching in the right Piriformis muscle. He had stabbing in the right hamstring, aching in the left hamstring, aching in both calves, stabbing in both shins and burning on the soles and dorsum of both feet associated with pins and needles & numbness over the right shin and lateral calf.


Weight bearing X-rays revealed his right realigned S1 screw was very oblique and the right L5 and L4 screws were medially angulated. He had a L5/S1 grade 1 anterior Spondylolisthesis which was immobile. L4/5 was Retrolisthetic which increased during extension with posterior triangulation. The L5/S1 foramen appeared to contain untreated facet joint osteophytes.

MRI scans revealed the right L5/S1 foramen to be distorted, narrowed and containing fibrosis. The right L5 recess pedicle appeared to be partially fragmented but these fragments had reunited. The right L5 screw appeared to be outside the pedicle in part.

Power in both Great Toes was reduced - severely on the right hand side.

Endoscopic Minimally Invasive Spinal Surgery: February 2009

Right L5/S1 Spinal Probing and Discography and Endoscopic Lumbar Decompression and Foraminoplasty.

This was an extremely difficult approach with massive fibrosis around the Dynesis system and in the paravertebral gutter. The orientation of the screws and Dynesis ligament blocked the normal approach. The tissues around the foramen were gritty and appeared to be calcifying. Reamers were required to gain access to predominantly the lower half of the foramen. The upper half was blocked to access. A facet joint osteophyte was removed and the extensive scarring around the nerve was removed. The foramen was undercut with trephines to gain access and decompression to the epidural space. The undercutting was extended with the laser and perineural scarring, tethering to the inferior pedicle, facet joint and disc was removed.

Patrick was able to feel his foot and move it normally after the decompression.


Patrick did well but suffered a set back following rather adventurous physiotherapy in stirrups. Consequently his symptoms recurred in more limited form requiring the removal of the screws on the right hand side. Currently instead of walking on 2 crutches he is able to walk for 30 – 60 minutes and sit for over an hour in comfort. He is involved in litigation. Should his symptoms deteriorate then a revision Endoscopic Lumbar Decompression & Foraminoplasty will be contemplated with greater prospects because the blockading screws have been removed. Currently he seems to be improving with the continued use of Muscle Balance Physiotherapy.