It is not uncommon for patients to experience no significant relief, worsening or recurrence of low back pain after low back surgery. In recent years, there has been an increase in the number of reports of post-lumbar back surgery syndrome (FBSS). FBSS is broadly defined as persistent pain or other discomfort in the low back, buttocks, or lower extremities after laminectomy or lumbar disc removal. In a narrower sense, it only refers to the absence of any improvement in clinical symptoms after multiple surgeries. Due to the autoimmune inflammatory reaction after surgery and scar formation, the incidence of FBSS is high, about 10-40%, and the treatment is more difficult to come up with, the patient suffers more physical and mental pain, and it easily leads to medical disputes. Yu Liang, Pain Clinic, Hangzhou First People’s Hospital
I. Causes
There are many reasons for the occurrence of FBSS, but most of them are related to surgery, including the mastery of surgical indications, case selection, surgical methods, operating techniques, and mental factors, which can be divided into three aspects: preoperative, intraoperative, and postoperative.
1, preoperative factors.
(1) Diagnostic errors: meeting only a single diagnosis of lumbar disc herniation or lumbar spinal stenosis, while omitting other diagnoses and inappropriate treatment accordingly, resulting in FBSS.
(2) Positioning error: wrong diagnosis of which segment the disc is herniated and which one or more lumbar nerve roots are compressed.
2. Intraoperative factors.
(1) intraoperative positioning error.
(2) Lack of thoroughness in surgery: incomplete removal of the nucleus pulposus, leading to re-protrusion; neglect of prolapse and free disc protrusion located in front of and behind the posterior longitudinal ligament; incomplete exploration and decompression of the lateral saphenous fossa, incomplete removal of the lateral wall portion of the ligamentum flavum constituting the fibrous canal on both sides of the vertebral arch and the stenosis caused by the coalescence of the articular eminence; neglect of the fibrous girdle of the dura mater; useless bending chisel to remove the bone superfluous at the posterior edge of the vertebral body; insufficient decompression of the spinal canal Insufficient decompression range of stenosis.
3. Postoperative factors.
(1) postoperative lumbar instability and slippage caused by excessive surgical scope: according to the literature, the incidence of lumbar instability and slippage is 34% for extensive laminectomy, especially for the scope of removal of the articular eminence, which is generally limited to 1/2~1/3 of the articular eminence.
(2) Re-protrusion of other segments, which is mainly caused by degeneration of adjacent segments.
(3) scar formation in the epidural space, i.e., epidural fibrosis, scar formation, which accounts for 5% to 24% of FBSS according to the relevant literature
(4) spinal stenosis due to regeneration of the vertebral plate, etc.
(5) aggravation of adhesions due to infectious factors: increased intervertebral infection due to intervertebral hemorrhage caused by surgical enlargement of the fibrocartilage plate.
II. Pathogenesis.
1, autoimmune reaction
Studies have confirmed that as the intervertebral disc ages and degenerates, the matrix lysis enzyme in the nucleus pulposus increases, and this enzyme can cause proteoglycans and linkage proteins to cleave into highly heterogeneous molecules with antigenic properties. Recent studies have also found that type I and II collagen of the disc tissue and cartilage plate matrix are also autoantigenic. After disc herniation or surgery, these autoimmune antigenic substances leak out and are exposed to the immune system to produce an immune response, mediating radiculitis and causing low back pain and leg pain in patients.
2.Inflammatory reaction of tissues
A large number of studies have found that the nucleus pulposus, phospholipase A2 (PLA2), IgG, IgM, proteoglycan ions, ATP and other disc-inflammatory substances can leak out of the intervertebral disc with disc herniation and surgery, stimulating the sinus nerve endings to cause pain. When chemical substances cause impulses in injury receptors to produce pain, neurons themselves can synthesize and release neuropeptides, such as substance P, vasoactive intestinal peptide (VIP), etc., forming a positive feedback loop that exacerbates the inflammatory response and further aggravates symptoms.
3.Degenerative changes of lumbar spine
Postoperative lumbar instability and slippage cause biomechanical dysfunction and aggravate degenerative changes in the lumbar spine, such as small joint synapses, intervertebral joint degeneration, and hypertrophy of the ligamentum flavum causing renewed stenosis and generating new compression symptoms.
4, soft tissue injury and inflammation outside the spinal canal
FBSS caused by soft tissue injury and aseptic inflammation during lumbar spine surgery.
5.Nerve root adhesions
On the basis of the original immune inflammatory reaction, together with surgical trauma and bleeding mechanization, scar formation, which makes the nerve
The nerve roots are adhered and compressed, resulting in pain and numbness in the affected nerve distribution area.
6. Increased sympathetic nerve excitability
Inflammatory reaction and abnormal immune response in the spinal canal can provoke the sinus nerve, reflexively causing increased sympathetic excitability, and the patient can feel soreness and numbness in the lumbar, hip and leg area, and be afraid of cold.
7. Non-bony lateral saphenous fossa stenosis
Non-bony lateral saphenous stenosis is a stenosis of the spinal canal caused by the herniated or bulging disc in front and the hypertrophy of the ligamentum flavum in the rear.
III. Clinical manifestations.
1.Lower back pain
It is mainly in the lower back or lumbosacral region, mostly at or adjacent to the surgical site. The nature of pain is mostly chronic dull pain, but it can also be acute severe pain, and some patients have pain allergy and touch-evoked pain. The pain is usually heavier at night, and the pain can be aggravated by cold, moisture and exertion, so that the patient cannot stand and walk.
2.Lower limb pain
Pain is mostly radiating, radiating from the hip, posterior lateral thigh, lateral calf to the back of the foot or the sole of the foot; patients with high intervertebral lesions show pain in the anterior thigh, and some even show pain in the lower abdomen.
3. Intermittent claudication
FBSS patients have more factors causing spinal stenosis, so intermittent claudication is not uncommon, which is manifested as low back pain or discomfort caused by increased walking distance, along with painful numbness in the affected limb or aggravation of the original painful numbness, and gradual relief of symptoms in squatting or lying position for a few moments.
4.Nerve function damage
Atrophy of the muscles of the lumbar and hip area and the muscles innervated by the affected nerves of the lower limbs, muscle strength loss, and foot drop may occur; sensory hypersensitivity, hypoesthesia or loss of sensation may occur in the lumbar and hip area and legs, and hypoesthesia is more common. If the patient’s cauda equina nerve is compressed or has injury inflammation, it can cause sphincter and sexual dysfunction, manifesting as constipation, frequent urination, urinary urgency, difficulty in urination, etc. Male patients may experience sexual dysfunction such as impotence.
5. patients often have weakened or involved knee tendon reflex or (and) Achilles tendon reflex.
6. there may be pressure pain at the interspinous, paraspinous, and extragluteal cutaneous nerve projections of the lumbar and gluteal regions, mostly radiating to the thighs.
7, there may be positive straight leg raise test, straight leg raise strengthening test and femoral nerve pulling test.
8, magnetic resonance enhancement examination is currently the best means of examining and evaluating FBSS, which shows protrusion of the medullary nucleus.
or prolapse, remnants of prolapsed nucleus pulposus, epidural scar adhesions, scar tissue compression of the dural sac, intradural cysts, and dural rupture; CT is better as a means to assess foraminal stenosis and other bony abnormalities, showing small articular proliferation combined with lateral saphenous fossa stenosis, disc protrusion or prolapse, and lateral saphenous fossa stenosis; where CT myelography is considered to be the best method to examine arachnoiditis and epidural fibrous ring. It shows deformation and thinning of the dural sac or complete obstruction, disappearance of the nerve root cuff, and still filling defect of the surgical gap contrast.
IV. Diagnosis
For patients with low back pain, the importance of correct diagnosis of the disease should be emphasized and awareness of the disease should be improved, especially for those with multiple complaints and heavy symptoms and unclear localization diagnosis, the medical history and detailed examination should be carefully understood, and auxiliary examinations such as CT and MRI are effective diagnostic methods.
Diagnostic criteria.
(1) A history of lumbar laminectomy.
(2) ≥ 1 year from the time of surgery.
(3) persistent pain in the lumbar, hip and leg areas or pain episodes ≥ 4 times per year, with pain affecting normal life and work.
(4) CT (or enhancement), MRI suggests recurrent disc herniation or epidural tissue hyperplasia.
V. Treatment
The treatment of this disease is quite difficult, and patients often lose confidence, causing psychological barriers and systemic dysfunction. In the treatment, doctors and patients need to build up confidence, be patient in treatment, and choose different treatment methods or combinations of methods for different causes (discogenic, neurogenic, extradural soft tissueogenic, etc.) and pathogenesis of FBSS to achieve the treatment purpose of inhibiting or eliminating inflammation, improving local tissue microcirculation, removing necrotic tissue, and accelerating tissue repair: 1.
1.Anti-inflammatory and analgesic therapy
For FBSS with inflammatory reaction as the main cause, systemic application of non-steroidal anti-inflammatory and analgesic drugs and injection of O3 and anti-inflammatory and analgesic solution into the lateral saphenous fossa can be used to suppress the autoimmune reaction, reduce the inflammatory reaction of the nerve root, reduce inflammation and analgesia, and relieve the symptoms and signs.
2.Relaxation of nerve root adhesions
After the injection of anti-inflammatory and analgesic solution or O3, the internal or external port of the intervertebral foramen or the combined internal and external ports are released by needle knife, followed by the nerve root release technique: small needle knife through the internal or external port of the intervertebral foramen is pressed against the bone surface to reach the nerve root adhesions, and the scar tissue and the compression band of the adhesions or the nerve roots are released or cut off, so that the nerve roots are released and freed. The anti-inflammatory and analgesic solution and O3 injected around the nerve root can both play a liquid and gas stripping role on the adherent nerve root and prevent re-adhesion after release. Postoperative intravenous drip of 250ml of mannitol with dexamethasone 5~10mg qd×3d can prevent the occurrence of reactive edema after nerve root stimulation.
3.Sympathetic nerve inhibition therapy
For FBSS with typical sympathetic nerve excitation symptoms (such as feeling soreness and numbness in the lumbar, hip and leg area, fear of cold), deep thermal therapy – intradiscal radiofrequency, sympathetic nerve block is feasible. Sympathetic nerve block or radiofrequency ablation can inhibit the overexcitation of sympathetic nerves and relieve the patient of symptoms such as coldness of the lower limbs caused by increased sympathetic excitability.
4.Treatment of lumbar disc protrusion
For those with symptoms caused by herniated discs (confirmed by CT or MR), treatment of the herniated discs is required. When treating FBSS, it is necessary to recognize the pathogenesis of the disc and take targeted treatment. Whether it is a recurrent or new disc herniation, different treatment methods or a combination of different methods should be selected according to the location, morphology, size, intradiscal pressure, integrity of the annulus fibrosus, and accompanying symptoms of the herniated disc. If the disc herniation is of the inclusion type (bulging herniation) and the intradiscal pressure is increased, the method of intradiscal decompression and ablation, such as low-temperature plasma ablation or pressure reducer decompression (spinotomy), is used; if the symptoms of increased sympathetic excitability are also combined, percutaneous laser decompression (PLDD) is the best choice. The results are better when O3 is injected at the same time as the above methods. If the nucleus pulposus protrudes into the vertebral canal, lateral saphenous fossa, intervertebral foramen or intervertebral orifice, radiofrequency thermal coagulation destruction within the herniation (target point) plus O3 injection is used; for prolapsed or upturned disc herniation, radiofrequency with O3 injection is used from the blind end to the basal part of the target point in a substratified manner to prevent the herniation from dislodging into the vertebral canal and nerve root canal and producing acute compression of the cauda equina and nerve root.
5.Anti-infection treatment
Apply effective antimicrobial agents systemically and inject O3 into the spinal canal once every 5 days for 3 times to reduce the symptoms significantly. Because of the serious back pain caused by postoperative disc infection, it was difficult to reach the disease area by simple application of antibiotics in the past, so the treatment effect was not good. With the addition of intralesional O3 injection, it can play a strong anti-inflammatory and anti-infective role in the infected space, so the effect is better.
6.Non-invasive treatment
Non-invasive treatment can be used as an adjunct to minimally invasive treatment to strengthen the effect of minimally invasive treatment; during the recovery period after minimally invasive treatment, non-invasive treatment can be applied to promote recovery, and during or after the course of minimally invasive treatment, non-invasive treatment can be applied to treat the more diffuse soft tissue lesions outside the spinal canal and inflammatory lesions inside the spinal canal. Non-invasive treatment mainly includes.
(1) pelvic traction: continuous hydraulic mechanical traction with a traction force of body weight minus 100 N for 30 min each time, once a day. Traction therapy can expand the volume of the spinal canal and is the conventional basic therapy for the treatment of disc lesions, but the force of traction should be reduced according to the pathological characteristics of FBSS.
(2) Tui-na massage: with tendon management, trembling pressure, leg pulling and lumbar compression, leg lifting and other techniques.
(3) physical therapy: ultra-laser, TENS, microwave heat therapy, ultra-short wave, etc. All the above treatments are 10 days 1 course, 3 days between each course, a total of 2~3 courses of treatment. Multi-electrode modulated medium-frequency pulse electrical stimulation acupuncture point method: Simultaneous stimulation of acupuncture points such as lumbar back and commissioning to treat FBSS has also shown better results: modulated medium-frequency current can improve local blood circulation, accelerate local blood flow, promote the transfer of local potassium, kinin, amines and other pain-causing substances, and can eliminate edema between tissues and nerve fibers, reduce pressure and achieve the purpose of indirect analgesia.
7.Chinese medical treatment.
(1) Internal use of Chinese herbal medicine: mainly Duluxiaosheng Tang with reduction, 1 dose daily, divided into 2 doses.
(2) Chinese medicine penetration: use DZY-1 medium frequency treatment instrument, the dose is under the sensory threshold~motor threshold, and the drug is Tong Piao liquid (blood activation and elimination of blood stasis, removing dampness and promoting ligament, tonifying liver and kidney type Chinese medicine), once a day, 25 min each time. Chinese medicine penetration therapy has obvious effects of analgesia, improving local blood circulation, anti-inflammation and softening scar, and at the same time can enhance the permeability of biofilm and promote Chinese medicine to enter the lesion, which is an effective method to enhance the local therapeutic effect of Chinese medicine.
(3) Acupuncture therapy: acupuncture points such as Kidney Yu, Huanjiao, Zhizhong, Shusanli and Chengshan.
8.Surgical treatment
Surgery has long been advocated for FBSS, but recent studies have found that although re-operation can loosen and remove scar and adhesions, adhesions and scars are recreated 3-6 months after surgery, and eventually most patients’ symptoms do not improve significantly, and the symptoms generally recur and worsen 8-16 months after surgery, causing radiating pain in the lower limbs plus lumbosacral pain. As the basic and clinical research on FBSS continues to deepen and a large number of clinical practices illustrate, it is difficult to avoid the occurrence of FBSS, especially the autoimmune inflammatory reaction, which cannot be eliminated by surgery, regardless of whether traditional or nontraditional surgery is used to treat lumbar synostosis. In recent years, more and more scholars have reported satisfactory results in the treatment of lumbar synostosis and FBSS using non-surgical methods. Therefore, physicians should strictly control the indications for reoperation. Our indications for reoperation for FBSS are.
(1) Severe radicular pain with neurological signs such as decreased muscle strength, reflex and sensory deficits, and clear pressure-causing factors by imaging, such as mislocalized or/and missed nucleus pulposus protrusion during the initial surgery, combined with lateral saphenous fossa stenosis, etc.
(2) Primary or secondary spinal stenosis after nucleus pulposus removal, mainly due to scar formation after laminectomy, or disc herniation combined with spinal stenosis with nucleus pulposus removal spinal canalplasty and decompression only
(3) Significant adhesive arachnoiditis.
(4) postoperative lumbar instability and frequent back pain, which seriously affects work and life.