Background: To determine whether the operation of LSD destabilizes the lumbar spine and leads to an increase in any pre-existing scoliosis or spondylolisthesis. Lumbar spondylosis, which commonly includes a degenerative listhesis and a scoliosis, is the commonest cause for stenosis in the lumbar spine. The standard operation for spinal stenosis remains a laminectomy with fixation and fusion in the presence of possible instability. The laminectomy, however, destabilises the spine and the instrumented fusion makes it a much bigger operation in patients often not best placed to cope with it. The more limited operation of LSD, which has previously been reported to this society, avoids a simultaneous fusion or instrumentation and has been shown to give long term symptomatic relief (1) Its possible effect on the stability of the spine has not previously been reviewed.

Methods: A retrospective clinical and radiological review of consecutive patients operated on for degenerative spinal canal stenosis with either a pre-existing scoliosis or degenerative listhesis or both. Sixty-one patients (44 female and 17 male) with a mean age at operation of 72.8ys (range: 54–85). Pre-operatively 35patients (57%) had a degenerative listhesis, 14 patients (23%) a lumbar scoliosis and 12 (20%) had both. The mean postoperative follow-up was three years (range from one to fourteen years).

Results: None of the 47 patients with a preoperative degenerative spondylolisthesis had any change in grade of the listhesis. Also no patient developed a new spondylolisthesis.

Of the 26 patients with a preoperative scoliosis, 10 progressed by a mean of 4.9° (range 2°–15°)

Conclusion: The results show that the operation of LSD was not associated with the development of a spondylolisthesis or a further progression of a pre-existing listhesis, and no patient developed a scoliosis. In those who had a scoliosis pre-operatively, 38% progressed and this only to a degree which we believe falls within the natural progression to be expected in such a group of patients. We believe these results support the view that the operation of Limited Segmental Decompression for spinal stenosis does not significantly destabilize the spine, even in a group that would appear most vulnerable, and as such there is no indication in such cases to consider a simultaneous instrumentation and fusion.

Introduction and Aims: To evaluate the long-term results of an operation which does not involve instrumentation or fusion and which leaves the midline structures intact.

Method: A retrospective clinical and radiological review of consecutive patients.

Results: One hundred and sixty patients (87 females and 73 males) with a mean age at operation of 68 (range 40–90); the majority of patients (79%) had either a one or two level bilateral decompression. The most common level decompressed was the L4/5 level (91%). The mean post-operative follow-up was 22 months.

Summary of background data: spondylosis, commonly involving a degenerative listhesis, is the most common cause of stenosis in the lumbar spine. The symptoms arise from root compromise of the stenotic level and surgery offers the only permanent cure. To date, the standard procedure remains a laminectomy with fixation and fusion in the presence of possible instability. A laminectomy, however, destabilises the spine and the instrumented fusion makes it a much bigger operation in patients often not best placed to cope with it. There has been, therefore, a need for an effective operation that does not compromise spinal stability.

Conclusion: At six weeks post-operation, 141 patients (85%) reported relief of leg pain and this rose to 90% at six months. One hundred and fifty-three patients (96%) reported an increase in their walking distance. Of those patients who also presented with back pain pre-operatively, 79% reported an improvement. There were no significant post-operative complications. The results were sustained at follow-up.

The operation of limited segmental decompression for degenerative lumbar spinal stenosis has been found to be effective, safe, and providing good long-term results, without compromising the existing spinal stability. Appropriate patient selection and attention to operative technique are of paramount importance.

Introduction: Spondylolytic spondylolisthesis is a not uncommon cause of back pain in adults. The initial management, especially for the low grade slips, is usually conservative. When this fails or is deemed inadequate surgical options are considered. The principles of surgical treatment involve a fusion of the painful segment or segments (usually with instrumentation), with an associated decompression if there is radicular leg pain. Some authors also propose a simultaneous reduction of the slip. Most reports in the literature on adults have a short follow-up.

Materials and method: This paper reports the results of surgery from two centres carried out between 1993 and 1998 on 75 adult patients using the same indication for surgery and the same surgical technique. The indication for surgery was a significant reduction in the quality of life with persistent low back and/or leg pain after conservative treatment for a minimum of six months. The surgery involved an in situ posterolateral fusion with pedicular fixation (Oswestry system) with a simultaneous decompression for radicular involvement. The average operating time was 2.5 hours (range 2–4) and the average blood loss 850 mls (range 300–2300). The mean follow-up was 61 months (range 24 to 95).

Results and conclusion: A solid fusion was considered to be present in 71 of the 75 cases (95%) using the Lenke and Bridwell (1997) criteria for radiological union. Seventy-two of the 75 cases (96%) had a very satisfactory clinical outcome (Ricciardi et al 1995). The complications were limited – two superficial wound infections and one deep wound infection which resolved after debridement of the wound. There were no neurological complications.

The authors believe that with careful patient selection an instrumented in-situ posterolateral fusion is a safe and effective operation for symptomatic low grade slips providing good long term results.