Lumbar canal stenosis
It is an abnormaldegenerative spine condition consisting of a narrowing of the spinal canal through which nerves that give sensitivity and mobility to the legs go through. This decrease in calibre can be of the entire lumbar spine, segmental (at one or several vertebral levels), or extremely localised in the area where the nerve roots run in the canal (lateral recess) before leaving the spine.
There are often changes in the size or shape of the spinal canal as a result of ageing. In normal conditions there is enough space in the openings of the spinal bones to accommodate the nerve fibres that branch out of the spinal cord; however, when the size of these openings is reduced (due to excessive growth of the bone or the adjacent tissue) nerve compression may occur.
The structures adjacent to the spine can also be affected in the following ways:
- Spinal ligaments can thicken and harden
- Bones and joints (often affected by osteoarthritis) may enlarge; can develop bone spurs
- Discs may protrude or sink
- The vertebrae can slip out of place
You should discuss your symptoms with the doctor. A physical examination can help determine the severity of the condition and in case symptoms of weakness or numbness appear.
A neurological examination evaluates abnormalities in strength and sensation and provides objective evidence of chronic compression of the nerve root caused by spinal stenosis. The doctor may also order imaging tests such as x-rays, magnetic resonance imaging (MRI) or a computed tomography (CT) scan to confirm the diagnosis.
The narrowing of the spinal canal can affect or exert pressure on the nerve roots, causing pain and discomfort.
Patients with spinal stenosis in the back often feel pain in the buttocks or a tingling sensation in the thigh or leg that occurs when standing (extension) or walking. Discomfort is usually relieved by leaning forward (flexion) or resting. In some cases patients will complain of back pain, in addition to leg pain and weakness.
When is the intervention indicated?
Once lumbar stenosis is diagnosed, and after conservative medical treatment has failed (analgesics, physiotherapy and sometimes infiltrations), surgical treatment must be considered.
The intervention must be designed to adapt to the problem and situation of each patient. The objective must be to release nerve structures compressed by said stenosis.
What is the operation about?
The surgical approach is performed through a linear incision in the back,following the line of the spine at the height where the stenosis is located. All the surgical intervention will be monitored by X-rays. Depending on the extension of the narrowing, an opening of the posterior part of the vertebrae will either be made wider (called laminectomy), or more localised by removing part of the posterior part of the vertebra,as well as the yellow ligament that compresses the nerve structures.
In case there is instability between the vertebrae or if we need a large resection of part of the vertebra to decompress the nerves, and consequently cause instability, the operation will include a flange bracketwith screws and rods, with or without a box, between vertebrae to immobilize said spaces (arthrodesis). If this operation is necessary, the patient will retainalmost the same spine mobility as before the intervention, since the spine’sflexion and extension movements depend mainly on the hip joint.
What are the risks, complications and possible sequelae?
The complications of this intervention are very rare, but some adverse effects may occur:
1. During the first days pain is common in the intervened region.It will recede with painkillers.
2. You may experience pain in the lower extremities due to nerve irritation in the first few days.
3. Wound infection in both superficial and deep planes. Antibiotic prophylaxis is systematically used to reduce this risk.
4. The risks of thrombosis are not frequent unless you have a history of predisposition.
5. Sometimes bladder catheterisation is needed, which may cause discomfort and occasionally urinary infection.
6. If you had leg paralysis or strength loss prior to surgery, we cannot guarantee that you will recover strength with the intervention. It will depend on how long the case has been going on and how intense the injury is.
7. If you have an area of the extremities clogged or numb before the operation, it is possible that this will remain afterwards or take a long time to recover.
8. During the intervention it is necessary to manipulate the nerve roots. A very rare complication is nerve injury.
9. Other very unlikely complications may be dural rupture and leakage of cerebrospinal fluid with risk of infection, or ureter / abdominal vessels injury.
Postoperative Lumbar Canal Stenosis
After the intervention, the patient usually stays in the post-anaesthetic recovery area (REA) for a few hours and then returns to bed, remaining hospitalised for 5 to 7 days andreceiving daily care for surgical wounds, medication, postural changes, control of vital signs and commencement of rehabilitation in the pertinent cases. The stitches are usually removed after approximately 7 days.
The postoperative lumbar pain can be intense if extensive muscular dissection was required to release the nerves. To alleviate this pain you will be prescribed plenty of painkillers, including morphine derivatives if needed. This situation is usually temporary and recedes with bed rest and proper medication. By the second or third day the patient can get up and start walking, usually with a lumbar girdle.
What happens after being discharged?
The postoperative recovery period is variable and can range from one to six months. Below you will be given a series of useful tips during the first month after surgery.
When the head practitionertreating your case approves the discharge, you will receive a clinical report detailing the characteristics of your illness, the type of intervention performed and the treatment to be followed at home. To follow up on the evolution of your case, you will be sent to Neurosurgery Outpatients within a specific period.
In general, after a few weeks of the intervention patients can return to their normal activities avoiding important physical efforts. A series of physiotherapeutic or rehabilitative measures that your doctor will detail is recommended. Sometimes you should continue with medical treatment.
The initial postoperative recovery period lasts up to 6-8 weeks after the intervention. Remember that during this time you should try to keep physical and mental rest, avoid trips and journeys, and take the series of measures listed below:
FIRST TWO WEEKS
You should try to think that you will continue the period of hospitalisation at home for a few more days. The first days you will find yourself more comfortable with a lumbar girdle – try not to get too used to it. You must place it when you get up – there’s no need to use it in bed. Take the medication exactly as prescribed by your surgeon. If you are receiving any other treatment for any other disease, you should continue to do so unless you are told otherwise. The surgical wound should be kept clean and dry. You can shower, with assistance, and then dry the wound well with a sterile pad or gauze, brush it with povidone-iodine (PVP-I, Betadine) and finally cover it with a sterile dressing. Please be very careful in the shower. The stitches should be removed some seven days after surgery.
Try not to sit in low chairs or seats for a period of two weeks. Avoid a sofa if yourback is not going to be completely straight. You may sit on a high stool, or place one or two cushions on a chair, preferably with armrests. During the first week you should alternate periods where you sit on a comfortable chair, walksaround your house and bed rest. Do not leave home until sutures are removed.
From the second week, if the lumbar pain allows it, walk every day inbrief periods of time (15 minutes)while progressively increasing the distance. Do not travel by car or other means of transport during these two weeks (except to go to the health centre or visit the doctor). The first weeks will be more comfortable with a lumbar girdleyou must put on when you get up – no need to use it in bed.
You may still have pain in the wound or perhaps some residual symptoms– in the form of tingling or lack of sensitivity – persist in the leg(s), or you may notice pain in the lumbar region when moving. Keep in mind that complete healing requires between 6 and 8 weeks. Be patient. The wound must be completely healed and will not require any dressing but, if you wish, you may place a piece of gauze over the scar to avoid rubbing with your clothes. Start leaving home and walking increasingly long journeys, always on flat terrain and with sports shoes.Avoid stairs and slopes. Avoid unpaved roads. You can walk along the seashore barefoot if there is not much slope. Keep wearing the lumbar girdle during this first month especially when going for a walk – youcan take a rest from it when sitting or in bed. You may use normal chairs (i e, that are not too low): spring out your buttocks until they touch the backrest, and then proceed to sit down without bending your back.
Walk on flat terrain and with sports shoes, if you can, for one hour every day. At the end of the fourth week you should go to the doctor’s office for a review.