Decompression of the lumber spine for spinal stenosis is the most commonly performed spinal surgical procedure in patients over 60 years old. The aims of surgery are to relieve compression of the spinal nerves and retain integrity of the structural elements of the spinal column and its function as a supportive structure. In trying to avoid excessive removal of the posterior supportive structures of the spinal column without compromising full and safe decompression of the spinal nerves, techniques are being developed to reduce bone removal but also allow access to the spinal canal. One such micro-decompression involves a hemi-laminectomy and lateral recess decompression on the more symptomatic side followed by undercutting the spinous processes and decompressing the opposite side from within the canal aided by the use the operating microscope, a high speed burr and a copper moldable retractor to protect the dura and nerves. We have reviewed our first 100 consecutive patients who have had a spinal micro-decompression over a period of 5 years. 58 Female and 42 male patients are included in this series. Mean age was 65 years. Patients were assessed by a combination of clinical review and self-assessment questionnaires. After a follow-up period of up to five years (mean 3.5 years) we have seen symptomatic late instability develop in four patients requiring a further surgical procedure in two of these. Symptoms typically developed two years after the original operation following an initial improvement in radicular symptoms and back pain. This compares favourably with published results for wide decompression where re-operation rates of 18% are reported. We have analysed the cases of delayed instability in more detail to evaluate whether the late deterioration could have been predicted. Micro-decompression is shown to be safe with few complications and has advantages over wide decompression without compromising safety.
The main objective of our review was to access the inter-net websites providing information on non operative treatment of scoliosis and to assess the evidence for each treatment in the medical literature.
These treatments were then entered for search in Medline and Embase, only 45% (9/20) of these treatments were found to have been described in the medical literature.
Spinal lipomatosis is seldom reported in spinal literature and although the condition occurs commonly, we seldom recognise it in reviewing spinal MRI scans. We aim to highlight the condition and show MRI signs to allow easier recognition. We also introduce a new method of evaluation of the severity of the condition using T1 MRI axial views to evaluate the area of the spinal canal involved in the pathological process. We have evaluated 30 patients with a diagnosis of spinal lipomatosis made on sagittal MRI scanning of the spine. The T1 and T2 axial images have been evaluated using standard digital software which allows calculation of the surface area occupied by fat and allows representation of this as a ratio to total canal diameter. This has then been correlated to the traditional method of classifying lipomatosis on sagittal MRI sequences. We have found this method useful and believe it provides a more accurate representation of how fat in the canal may produce symptoms of nerve compression. This shows that the condition behaves more like our traditional understanding of spinal stenosis with symptoms more likely when the relationship of fat to canal reaches greater than 50%. This approach to spinal lipomatosis has not been described before but we feel produces a better understanding of the condition than we have had before by using a classification based on purely on sagittal MRI sequences.
Thirty five patients who underwent surgical correction of a degenerative scoliosis were identified. The pre-operative standing antero-posterior radiographs were compared with the coronal MRI images and Cobb angles measured. The mean patient age was 64 years old. The mean increase in Cobb angle in the degenerative curve on standing was ten degrees. This was not associated with age or magnitude of curve. A degenerative scoliosis is often considered inflexible. These results show that such curves do retain some flexibility and therefore patients may present with dynamic symptoms not represented on supine MRI images. Furthermore, pre-operative supine radiographs will identify the degree of flexibility that can be expected intra-operatively.
Decompression of the lumbar spine for spinal stenosis is the most commonly performed spinal surgical procedure in patients over 60 years old. The aims of surgery are to relieve compression of the spinal nerves and retain integrity of the structural elements of the spinal column and its function as a supportive structure. In trying to avoid excessive removal of the posterior supportive structures of the spinal column without compromising full and safe decompression of the spinal nerves, techniques are being developed to reduce bone removal but also allow access to the spinal canal. One such micro-decompression involves a hemi-lami-nectomy and lateral recess decompression on the more symptomatic side followed by undercutting the spinous process and facet joints and decompressing the opposite side from within the canal aided by the use the operating microscope, a high speed burr and a metal guard to protect the dura and nerves. Although previous reports exist, as yet, there is no long-term evidence that the theoretical benefits of this “micro-decompression” translate into real clinical improvement in outcome with a reduction in the incidence of post-operative instability in comparison with the bilateral “fir-tree” type of decompression. We have reviewed our first 100 consecutive patients who have had a spinal micro-decompression carried out by a single spinal surgeon over a period of 5 years. Patients with central or lateral recess stenosis with unilateral or bilateral symptoms were considered for this procedure with 58 female and 42 male patients included in the follow-up series. Mean age was 65 years. Patients were assessed by a combination of clinical review and self-assessment questionnaires. After a follow-up period of up to 5 years (mean 3 years) we have seen symptomatic late instability develop in 4 patients requiring a further surgical procedure in 2 of these. Symptoms typically developed 2 years after the original operation following an initial improvement in radicular symptoms and back pain. This compares favourably with published results for wide decompression where re-operation rates of 18% are reported. We have analysed the cases of delayed instability in more detail to evaluate whether the late deterioration could have been predicted. This has allowed us to clarify the specific indications and contra-indications to the micro-decompression procedure. Lumbar micro-decompression has proved to be safe with few complications. It would appear that this technique has advantages over wide decompression without compromising safety but it will be important to continue with longer term follow-up of these cases.
INTRODUCTION: No previous cases of avascular necrosis (AVN) of the femoral head have been described in the World Literature, to our knowledge. This paper reports the catastrophic failure of the bony integrity of the hip in three patients (five hips) following prolonged hypotension during spinal surgery for spinal stenosis on a Montreal mattress and offers advice to prevent this complication of spinal surgery. A theory to explain this phenomenon is explored, but we recognise its limitations with such a small sample. METHOD: The case notes of all patients undergoing decompressive spinal surgery in our hospitals between March 1997 and December 2001 were examined (168 cases). Three patients had been identified as suffering from AVN following prolonged hypotensive anaesthesia prospectively. No other cases were identified after the notes review. Clinical notes and pre- and post-operative radiographs were studied in an attempt to identify the factors that caused this complication in these three patients. RESULTS: Between 1997 and 2001, 168 patients underwent surgery for multi-level symptomatic spinal stenosis in our hospitals. Forty percent of the patients had an instrumented fusion as well as a decompression. During this period, three patients had catastrophic AVN of the femoral head requiring total hip arthroplasty soon after their spinal operation. All had some clinical and radiological evidence of hip arthritis at their pre-surgery visit. All subsequently, presented with symptomatic hip AVN within six months of the index operation. In two, histology confirmed the diagnosis of AVN, and typical changes of AVN were well demonstrated on MRI in the third patient. CONCLUSIONS: The development of avascular necrosis of the femoral heads following surgery for spinal stenosis may be due to a femoral head at risk being exposed to hypotensive anaesthesia, prone positioning on a Montreal mattress or a combination of the two. Careful intra-operative positioning may reduce the risk of this occurring after spinal surgery. However, close post-operative surveillance and a high index of suspicion of worsening hip pathology in patients who appear to mobilise poorly after lumbar spinal surgery may be the only method of early detection of this condition.