With the aging of the population and the increasing demand for quality of life among the elderly, the number of surgeries for degenerative lumbar spine disorders has increased year by year, and lumbar spinal stenosis is a common disease among degenerative lumbar spine disorders in the elderly. From February 2003 to February 2009, we performed 67 cases of lumbar spinal stenosis in elderly patients over 65 years of age with different treatment strategies for different lesions, and received more satisfactory results, as reported below.
1. Data and methods
1.1 General information
Sixty-seven patients, 42 males and 25 females, aged 65-78 years old, average 68.4 years old. The duration of the disease was 2–15 years, with an average of 5.5 years. The main manifestations of the patients were low back pain and discomfort with intermittent claudication and numbness and weakness of the lower limbs, which were obvious after walking and exertion and reduced after rest. Most patients with spinal stenosis alone have no obvious positive signs on physical examination, while some patients with other disc disorders may have positive straight leg raising test, lower extremity muscle strength and nerve reflexes on physical examination, such as combined disc herniation.
The main factors causing spinal stenosis are bony factors such as degeneration of the articular eminence or thickening of the vertebral plate, hypertrophy of the ligamentum flavum, slip of the lumbar spine and adhesions in the spinal canal after lumbar spine surgery, and re-protrusion of the intervertebral disc after surgery. Arthrogryposis degeneration or plate thickening leads to bony central spinal stenosis or nerve root canal stenosis.
Among them, there were 34 cases of spinal stenosis caused by bony factors or bony factors with hypertrophy of the ligamentum flavum, 12 cases of lumbar spinal stenosis combined with disc herniation, 9 cases of bony spinal stenosis combined with degenerative slippage, 6 cases of postoperative recurrence of lumbar disc herniation and leakage of prolapsed disc tissue combined with spinal stenosis, and 6 cases of spinal stenosis combined with degenerative scoliosis. Surgical segments: 45 cases of single-segment surgery, 2 cases of lumbar 2-3 segments, 13 cases of lumbar 3-4 segments, 26 cases of lumbar 4-5 segments, 4 cases of lumbar 5-sacral 1 segments, 17 cases of double segments, and 5 cases of triple-segment lesions.
All cases had been treated with drugs, traction, massage and local closure or sacral canal closure before surgery, but the efficacy was not good.
1.2 Preoperative preparation
Preoperative routine ancillary examinations were completed, including routine blood tests, coagulation tests, liver and kidney functions, electrocardiogram, chest X-ray, etc. to understand the functions of liver, kidney, heart and lung and other important organs, and to assess the patient’s tolerance to anesthesia and surgery. The assessment of cardiopulmonary function is particularly important. Imaging examinations include frontal and lateral lumbar spine and power radiographs, and if necessary, double oblique lumbar spine radiographs, CT and MRI examinations for detailed understanding of the intervertebral disc and intravertebral canal to determine the surgical plan.
For patients with preoperative combined hypertension, diabetes and other disorders, corresponding medical treatment was given before surgery to adjust to normal or near normal level as far as possible.
1.3 Surgical method
Tracheal intubation and general anesthesia in prone position were used for surgery. The surgical treatment was performed according to the preoperative surgical plan, including 11 cases of posterior lumbar laminectomy or hemi-laminectomy for nerve root canal decompression disc removal, 37 cases of total laminectomy for canal decompression disc removal, and 19 cases of total laminectomy for canal decompression intervertebral implant internal fixation. For those who did not perform internal fixation, attention was paid to the subtle decompression of the spinal canal, the lamina was subconsciously resected from the medial side to enlarge the spinal canal, and attention was paid to the subconscious resection of the synovial joint and the extent of resection to protect the stability of the synovial joint.
Intraoperative attention was paid to the exploration to protect the nerve roots and decompression of the nerve root canal. In cases of combined disc herniation, the herniated disc is removed. If a herniated disc is considered preoperatively, but the protrusion is not obvious intraoperatively and is positioned correctly by fluoroscopy, the intervertebral space may be left untreated to maintain intervertebral stability. In reoperative patients, attention should be paid to decompression from the normal range, revealing the epidural sac and gradually releasing the epidural scar and releasing the nerve roots, and for those with obvious adhesions that are difficult to release, the adhesion zone does not need to be completely released and removed, and the free nerve roots are released as far as possible.
For combined lumbar instability and surgical decompression that affects the stability of the spine, internal fixation intervertebral bone graft fusion should be performed at the same time, paying attention to the treatment of bone graft bed and adequate bone grafting.
1.4 Postoperative treatment
After surgery, pay attention to the general condition and vital signs of the patients, pay attention to the amount of drainage blood, and supplement red blood cell suspension if necessary. Apply antibiotics to prevent infection. Bed rest is appropriate, and the bed rest time is decided according to the operation mode and the physical quality of the patient. For patients with simple laminectomy or hemi- or total laminectomy for decompression disc removal, they are generally bedridden for 3-4 weeks after surgery.
In the case of internal fixation with intervertebral implant fusion, bed rest is appropriately shortened to 1-2 weeks for those who apply intervertebral fusion device, and about 6-8 weeks for those who apply autologous bone implant. During the bed rest period, patients were encouraged to perform functional exercises for the low back muscles and active extension and flexion activities for the lower limbs of straight leg raising and ankle joint toes to prevent bed rest complications.
2.Results
In 67 cases, the operation was successfully completed and the patients passed the perioperative period, with an operation time of 60-150 minutes and blood loss of 100-750 ml. Intraoperative and postoperative complications: one case had an intraoperative dural tear, which was repaired with sutures, and two cases had a decrease in muscle strength of the dorsiflexion of the bunion and dorsiflexion of the ankle compared with the preoperative period, with a muscle strength of grade III, which was considered to be due to intraoperative nerve root pulling and was treated with neurotrophic drugs. One case of urinary tract infection during hospitalization was cured by bladder irrigation and anti-infective medication.
There were no serious complications such as pulmonary infection and pulmonary embolism. 64 cases were followed up from 13 months to 2 years after surgery, with an average of 18 months. The postoperative efficacy was evaluated according to the standard of surgery for low back pain of the Chinese Orthopedic Society Spine Group [1]. 23 cases were excellent, 35 cases were good, and 6 cases were poor. The excellent rate was 90.63%.
3. Discussion
3.1 Characteristics of lumbar spinal stenosis in the elderly
Elderly patients with lumbar spinal stenosis have the following characteristics.
① The patients are old and have a high proportion of combined chronic diseases such as hypertension, diabetes, coronary heart disease, bronchitis and other diseases;
②More factors lead to spinal stenosis, both bony spinal stenosis factors such as congenital central spinal stenosis and spinal stenosis caused by soft tissue such as ligamentum flavum hypertrophy, and some patients have a history of previous lumbar spine surgery, spinal adhesions and other factors. The treatment is relatively complicated;
(3) The elderly combined with osteoporosis, and due to the combination of other cardiovascular diseases, vascular fragility, intraoperative bleeding is relatively large, for those who need to implement internal fixation surgery due to the large decompression range, the solidity of internal fixation is also a challenge.
3.2 Surgical indications and selection of surgical methods
Indications for surgery: it is generally considered that patients with significant symptoms of low back pain, affecting daily life; intermittent claudication, progressive walking distance limitation; most or progressive neurological deficits and cauda equina symptoms; combined lumbar instability or disc herniation; invalidated by regular conservative treatment for 4-6 weeks; no obvious contraindications to surgery and confirmed by imaging are considered for surgical treatment.
The choice of surgical method mainly involves two aspects: the choice of surgical segment and the choice of surgical method.
(1) Selection of surgical segments: Since lumbar spinal stenosis in the elderly often accumulates multiple segments and in some cases is combined with lumbar disc herniation and vertebral slippage, it is important to determine the responsible segment or gap that causes symptoms for surgical management. In cases of multi-segmental stenosis with clinical signs and symptoms in a single segment or plane despite imaging, the segment or gap that matches the clinical examination and imaging is the responsible segment or gap. Only the responsible segment or gap should be treated. Otherwise, multi-segmental decompression is traumatic and affects the stability of the spine and the efficacy of surgery.
The choice of surgical approach: For spinal stenosis in the elderly, there is no definite conclusion on the surgical approach, such as whether total laminectomy decompression or decompression followed by internal fixation is necessary. The authors believe that surgery should be performed for the cause of the stenosis and an individualized treatment plan should be adopted. If the patient only has pain and numbness in one limb and the imaging confirms unilateral nerve root canal stenosis, total laminectomy is not necessary and only unilateral openings or half laminectomy with nerve root canal expansion and decompression can be performed.
If the patient shows bilateral weakness and numbness in the lower extremities and the stenosis is central or bilateral, it is necessary to perform a total laminectomy for decompression. There are different opinions on whether laminectomy and decompression should be followed by fixation and fusion. It is believed that for cases without obvious preoperative spinal instability, total laminectomy for lumbar spine disease is effective and has no significant effect on spinal stability, as long as intraoperative attention is paid to the extent of muscle stripping of the lumbar back, the extent of resection of the synovial joint is less than 50%, the stability of the small joints is maintained, and postoperative attention is paid to the functional exercise of the lumbar back and abdominal muscles.
The preservation of lumbar intervertebral joint mobility and lumbosacral joint mobility is valuable for elderly people whose lumbar spine mobility has been limited, and therefore should be preserved as much as possible.
The authors concluded that the indications for post-decompression fusion are.
(i) preoperative lumbar dynamic radiographs suggest lumbar instability and the patient has clinical manifestations of lumbar instability;
(ii) Combined lumbar spine slippage and lumbar dynamic radiographs suggest lumbar instability, and for degenerative slippage, there is no need to perform fixed fusion if there is no obvious aggravation of spinal instability on dynamic radiographs;
(3) For those who require extensive laminectomy for decompression of the spinal canal, involving bilateral synovial joints, which may produce postoperative spinal instability;
④For patients with high postoperative activity requirements and a large amount of activity, the first-stage fixed fusion should be considered at the same time of decompression.
⑤ For patients with a large decompression range in the second operation of the lumbar spine.
⑥Patients with obvious lateral lumbar lordosis deformity.
Several issues should be noted for the surgical treatment of geriatric spinal stenosis.
①When performing internal fixation surgery, attention should be paid to the treatment of the intervertebral implant surface to ensure the exactness of postoperative spinal fusion, and the treatment of the implant bed should not be neglected by only performing simple pedicle screw internal fixation.
The scope of surgical decompression should be combined with imaging to avoid blindly expanding decompression, which may affect spinal stability, and avoid incomplete decompression, which may affect surgical efficacy.
③ For cases of combined disc herniation, attention should be paid to avoid positioning errors and disc omission. Preoperative imaging data should be carefully studied and intraoperative findings such as incompatibility should not be taken as a fluke thinking that decompression will be fine and the operation should be ended easily, but the factors causing the symptoms should be found. In this group of cases, we encountered a case of recurrence of lumbar leg pain 12 years after surgery for lumbar disc prolapse. Preoperative MRI examination revealed that the last prolapsed disc was still located in the posterior part of the vertebral body, and the patient’s first postoperative symptom relief was estimated to be related to the decompression of the spinal canal.
④ Attention should be paid to the presence of other combined diseases causing low back and leg pain. In one case of recurrent lumbar leg pain 6 years after open decompression discectomy for lumbar disc herniation, the patient showed pain and numbness in both lower limbs, and MRI examination of lumbar spine showed herniated spinal stenosis in the same gap and the next gap, and the patient had more pain in the posterior part of both hips before surgery, and further examination showed positive 4-character sign of bilateral hip joints, and MRI examination showed bilateral femoral head necrosis.
(5) Management of combined osteoporosis: some authors performed internal fixation surgery for elderly patients with lumbar spinal stenosis, the nail tract was reinforced with bone cement at the same time when the pedicle nail was implanted, and we only performed cement reinforcement of the nail tract in one patient due to poor screw holding power during surgery, and routine attention was paid to the application of osteoporosis prevention drugs after surgery.
3.3 Attention should be paid to perioperative treatment
Perioperative treatment is an important factor in the success or failure of surgery for lumbar spinal stenosis in the elderly. Preoperative examination and preparation should be adequate, and the treatment of chronic diseases in the perioperative period has an important impact on the success of surgery, and combined diseases should be actively managed to adjust the patient’s condition to adapt to surgery. For example, in hypertensive patients, the application of antihypertensive drugs and the control of blood pressure at about 1.3/13.3KPa (160/100mmHg) is appropriate due to the physiological characteristics of the age group;
In diabetic patients, fasting blood glucose was adjusted between 5.6 and 9.4 mmol/L by diet control and application of hypoglycemic drugs, with a slightly higher than normal (6.4 mmol/L) as appropriate [7,8]. For cardiac function grade 3 or higher, severe heart failure, new myocardial infarction within 3 months, those who are already bedridden for a long time and unable to take care of themselves, severe osteoporosis, and failure of vital organs to remit are considered as contraindications [9]. Intraoperative application of general anesthesia with tracheal intubation is conducive to adjusting blood pressure, maintaining normal cardiopulmonary function, and stabilizing vital signs, while intraoperative attention should be paid to surgical operations to avoid unnecessary repeated decompression and shorten operative time.
During the postoperative bed rest period, patients should be instructed and encouraged to perform functional exercises, such as chest expansion, deep breathing, straight leg raising, active ankle extension and flexion exercises, and assistance in turning down to prevent long-term bed rest complications, such as pulmonary infection, venous thrombosis, pulmonary embolism, and decubitus ulcers. Encourage patients to drink more water to prevent urinary tract infections, etc.