THE IMPACT OF SURGICAL TREATMENT OF RADICULAR COMPRESSION SYNDROME OF LUMBAR OSTEOCHONDROSIS ON POSTURAL REGULATION Uryupin V.Yu., Konovalova N.G., Filatov E.V.

Novokuznetsk Scientific and Practical Center for Medicosocial Expertise and Rehabilitation for Disabled Persons, Novokuznetsk, Russia

More than 80 % of the world population suffers from degenerative and dystrophic processes in the spine with intense pain syndrome [1]. In 2003, the incidence of the abnormality in the population achieved 58-84 %, and the morbidity was 4-33 % [2]. Men suffer from it more often than women [3]. Most patients were patients of working age (25-55 years). Often, the disease is associated with professional activity [2]. High incidence of the disease causes the temporary loss of working capability, resulting in inevitable financial losses. The rate of disability in degenerative and dystrophic diseases of the spine is 4 cases per 100,000 of the population [4]. The modern health care has a task of increasing of quality of special medical care. Spinal abnormality is one of the priority directions in increasing quality of life. The supporters of conservative treatment often address to surgeon lately, resulting in formation of persistent neurological disorders relating to formation of continuous compression of nerve roots. Preliminary solution on necessity of surgery, and incorrect management techniques can form the opinion on low efficiency of surgical intervention. Compression radiculopathy of the lumbosacral spine shows such manifestations as pain syndrome and lower mild paresis, influencing on postural regulation and, as result, on a possibility of appropriate independent walking [5]. Surgery corrects the compression of roots as the abnormal basis of the described disorders.

Objective – to assess the impact of surgical decompression of roots in the lumbosacral spine on postural regulation in patients with radicular compression syndromes of lumbar degenerative disc disease.

MATERIALS AND METHODS

Postural regulation was studied in patients who received surgery for compression radicular pathology at the background of degenerative changes in the lumbosacral spine in the neurosurgery unit of Novokuznetsk Scientific and Practical Center for Medicosocial Expertise and Rehabilitation for Disabled Persons in 2017-2018. There were 30 patients (12 women) at the age of 28-61 (the mean age – 42.9 ± 9.3; Me = 38.7).

The inclusion criteria were presence of compression radicular symptoms of lumbosacral groups of nerves at the background of degenerative and dystrophic changes with resistance to conservative therapy and need for surgical correction; absence of clinical and radiologic signs in the spinal motional segment (SMS), and, as result, absence of the stabilizing stage of surgical intervention. The exclusion criteria were the need for decompression and stabilizing operations for the lumbosacral spine with compression radicular symptoms resistant to conservative treatment; clinical picture of the disease without need for surgical intervention, or efficient conservative treatment; concurrent neurological pathology, which could influence on integrity of the test; refusal from participation in the experiment.

All examined patients were divided into two groups: the first group included 21 patients with S1 root compression, which was isolated or combined with L5 compression. The second group included 9 patients with L5 root lesion, which was isolated or in combination with L4-5.

Before and after surgery, the standard clinical neurological examination was conducted, as well as magnetic resonance imaging (MRI) of the lumbar spine (LS), plan and functional X-ray study of LS, electromyography of the lower extremities. The intensity of pain syndrome was estimated with visual analogue scale (VAS).

The examination of postural regulation was conducted with testing during standing position and during walking, and computer stabilometrics. The stabilometric complex Trast-M Stabilo (Nevrocor) was used. The patients were examined one day before the surgery and on the 10th day after surgery. Romberg test was used. The square of migration of pressure center on the supporting surface, and deviations in frontal and sagittal planes during standing with opened and closed eyes was considered.

The results were analyzed with variational methods. Calculations were conducted with STATISTICA 10.0. Mann-Whitney’s test was used for estimation of statistical significance of differences in the unrelated groups of follow-up. Wilcoxon’s test was used for assessment of differences between the groups before and after surgery. The differences were statistically significant at p < 0.05.

The study was approved by the local ethical committee of Novokuznetsk Scientific and Practical Center for Medicosocial Expertise and Rehabilitation for Disabled Persons (the protocol No.3, 18 February 2019). Therefore, the conducted study corresponds to Helsinki Declare – Ethical Principles for Medical Research with Human Subjects, and the Rules for Clinical Practice in the Russian Federation.

RESULTS

The sample included the patients with mean age > 40. The clinical examination did not find any differences between the groups.

The complaints of pain in the lower extremities were reported by all patients. The mean VAS was 7. 23 patients complained of lumbar pain during vertical positioning (VAS = 5-8, average VAS = 6). The dynamic load increased the number of patients with pain to 26. 25 patients noted the increasing pain during supporting to the lower extremity by 1-2 points. All examined patients complained of muscular weakness and lack of confidence during supporting to the painful leg.

The manifestations of pain syndrome corresponded to the common picture of compression radiculopathy: intense burning or lightning pain from the lumbar spine spreading to distal parts of the extremity combined with decreasing sensitivity in the region of innervations of a compressed root (roots) and muscular strength in the corresponding myotome. Due to relatively short catamnesis (root compression did not exceed 1-1.5 months), we did not find any trophic disturbances.

The most common sign was rough paresis in the innervated myotome with decreasing strength to 2 points (p < 0.009, the table 1).

Table 1

Severity of paresis before and after surgical treatment, n = 30

Paresis degree	1 point	2 points	3 points	4 points	5 points
Number of patients before treatment	5	15	5	5	0
Number of patients after treatment	0	0	0	6	24

The right-sided symptoms were in the half of the examined patients. The left-sided and two-sided symptoms consisted the second group of the sample (10 and 5 cases correspondingly).

L5-S1 level was the most common one, leading to S1 root compression in most patients. L4-5 lesion was less common, as well as L5 root compression. S1 compression, as well as S1 in combination with L5 compression was more common than L5 in combination with L4, p = 0.031 (Fig. 1).

Figure 1

Compression level, compressed spinal root, n = 30.

Figure 1 Compression level, compressed spinal root, n = 30.

Most examined patients could stand and walk without additional support, but the examination showed the uneven distribution of load to the feet and body displacement towards the healthy lower extremity.

The data of stabilometrics confirms and concretizes the data of the clinical examination. At admission, the square of migration of the pressure center in most patients exceeded the statistical norm due to increasing deviations in frontal and sagittal planes. Deprivation of optical entry did not cause any significant growth of deviations and square of the statokinesiogram, resulting in significant intribution of proprioceptive information into regulation of posture (the table 2). The interesting fact is a slight decrease in deprivations in the frontal plane during standing with closed eyes as compared to the usual standing.

Table 2

Average figures of statokinesigram before and after surgery

Values	Standing with opened eyes							Standing with closed eyes						Romberg’s ratio, %
	Square, mm²		Deviation					Square, mm²		Deviation
			Frontal plane, mm			Sagittal plane, mm				Frontal plane, mm		Deviations in sagittal plane, mm
General group, n = 30
Before treatment		150.6			3.0	4.3	159.7		2.9		4.5		106.0
After treatment		94.9*			2.0*	4.2*	112.6*		2.2		4.9*		118.7
Time course, %		37.0			33.3	2.3	29.5		24.1		-8.9		-12.0
First group, patients with compression of S₁ and S₁, L₅, n = 21
Before treatment		175.7			3.6	4.3	183.6		3.5		4.3		104.5
After treatment		101.2*			2.1*	4.1*	109.9		2.3		4.6*		108.6
Time course, %		42.4			41.7	4.7	40.1		34.3		-7.0		-3.9
Second group, patients with compression of L5-L4, L5 roots, n = 9
Before treatment		92.5⁺		1.8⁺		4.8⁺	119.8		1.8		4.9⁺		129.5
After treatment		87.6*		1.8*⁺		4.4*	120.6*⁺		2.0*⁺		5.8*		137.7*
Time course, %		5.3		0		8.3	-0.5		-11.1		-18.4		-6.3

Note: * – p < 0.05 – statistical significance in the group before and after surgery; ⁺ – p < 0.05 – statistical significance of differences between the groups.

The analysis of stabilograms identified that changes were not similar in all patients. The most evident disorders of postural regulation – the increase in the square of statokinesiogram and deviations in the frontal plane – were observed in the patients of the first group with single S1 root compression and S1 in combination with L5 compression. L4-5 root compression (separately or in combination) did not cause any significant disorders of postural regulation in patients of the second group. When standing with opened eyes, all studied values of the statokinesiogram were reliable. Eye closure was accompanied by increasing range of values of the statokinesiogram in the group. The reliable differences were only differences in the range of deviations in the sagittal plane.

After treatment, all patients noted the significant improvements. The pain syndrome disappeared in 28 examined patients. Two patients demonstrated the pain with VAS = 2-3. Regression of motion disorders was in 100 % of cases and was accompanied by increasing strength of the leg muscles up to 4-5 points, resulting in equal strength of muscles of both extremities. Both factors caused the full disappearance of paresis in 24 patients (the table 1).

All examined patients demonstrated better walking and standing. The examination showed more equal distribution of load during standing and locomotions. Lateral displacement of the body disappeared. Scoliotic parameters reduced.

Postural regulation improved according to the following data of stabilometrics: decreasing square of supporting by 37 % due to decrease in deviations in the frontal plane with insignificant decrease of deviations in the sagittal plane. All changes were reliable. Optical entry deprivation was accompanied by higher square of the statokinesiogram (as compared to the primary examination) due to intense growth of deviations in the sagittal plane in insignificant increase in deviations in the frontal plane (the table 2). Comparison of values of the statokinesiogram in standing with closed eyes before and after treatment identified a statistical significance of decrease in square of the statokinesiogram and increase in deviations in the sagittal plane.

The analysis of values of stabilometrics in the groups identified some evident changes in the patients of the first group, where the square of the statokinesiogram and deviation in the frontal plane during standing with opened eyes decreased by more than 40 %. When standing with closed eyes, these values decreased by more than one-third (the table 2). As result, the Romberg’s coefficient increased.

The changes in stabilograms in the second group also testify some positive time trends in postural regulation. So, when standing with opened eyes, the square of the statokinesiogram and deviations in the sagittal plane decreased. Eye closure increased the square of migration of the pressure center along the supporting surface, and increased the deviations as compared to standing with opened eyes and even with the primary examination. As result, the Romberg’s coefficient increased slightly.

Different intensity of changes in regulation of posture in the patients of both groups as result of the treatment influenced on the reliability of differences between the groups. The recurrent study in standing position with opened eyes identified some reliable differences in only one value. However the values of vertical position support with closed eyes in both groups differed in the square of the statokinesiogram and deviations in the frontal plane, i.e. with values which did not show any reliable differences previously.

DISCUSSION

The study confirmed the data by R.A. Kozhakhmetova, K.S. Mirzaeva, F.Sh. Kadyrbekova [6, 7] and other authors concerning the decrease in age of patients with compression radicular syndromes of lumbar osteochondrosis. The specialists in preventive medicine and healthy life style can show their interest with causes and prevention of this event. The task of clinical medicine is the fastest and fullest recovery of health in this population of young people of working age.

The clinical picture of pathology includes the pain symptom and deficient symptoms. This picture determines the motional and sensitive disorders by the type of peripheral paresis of the extremity. The disorder of postural regulation manifests itself in increase in square of the statokinesiogram, deviations, and is characterized by decreasing stability of patients. Considering the intensity of root pain syndrome and presence of peripheral paresis, the identified changes in postural regulation are quite exactable. Similar studies were conducted by the employees of Novosibirsk Research Institute of Traumatology and Orthopedics. The results have been confirmed by the present studies. Some changes in stabilograms before and after surgical treatment were found. It corresponds to the changes in the first group of patients [5]. But the differences, which were found after analysis of two groups of patients with different types of root compression, requires for additional reviewing.

S1 root lesion (separate or combined with L5) caused a sharp decrease in persistence, resulting in increase in the square of the statokinesiogram and significant increase in deviations in the frontal plane. Deprivation of optical entry was not accompanied by significant increase in these values. The changes in optical entry in regulation of posture of these patients are not so significant. The main role is given to proprioceptive sense.

Single or combined compression of other roots (L4, L5) did not cause any significant changes in deviations and the square of the statokinesiogram. Eye closure highly worsened the position stability and was accompanied by multidirectional changes in deviations in the frontal and sagittal planes. It means a high possibility of necessary substitution of afferent provision of posture control from visual to proprioceptive type, which was insufficient, with change in strategy of posture control to less efficient one.

One may suppose that the executive (motional) component suffers in the first group, whereas the motional component copes with the task of posture regulation, but proprioceptive sense suffers in the second group.

For understanding the identified differences, we can review the features of lumbar radicular syndromes in lesion of the spine at L4-S1 level. Affection of each root is accompanied by pain, paresthesia or hypalgesia in the region of corresponding dermatome. A lesion of L4 root causes the weakness, hypotonia of quadriceps, a decrease in knee reflex, weakness and hypotonia of tibial muscles, with such manifestation as external rotation of the foot and its “flapping” during walking. L5 root lesion gives the weakness of long extensor of the toe, short extensor of toes and posterior tibial muscle with loss or decrease of Achilles jerk. A lesion of S1 root causes the hypotonia and weakness of fibular, gastrocnemius and salens muscles, a decrease or loss of Achilles jerk. Moreover, rotation and plantar flexion of the foot are weak.

Therefore, S1 root provides the main innervation of leg muscles, which make the important energetic contribution for controlling the vertical posture in the human. Therefore, a lesion of this root causes a more intense decrease in persistence of vertical posture.

Proprioceptive information from muscle spindle of muscles of the leg and the foot and bursa-tendon apparatus is exclusively important for sensory provision of vertical posture. It is warped in lesion of each of the mentioned roots, but the muscles, which are responsible for energetic provision of vertical posture, suffer to a lesser degree. Therefore, the patients control the vertical posture with opened eyes, when a disadvantage of one sensory flow is compensated by another one. Deprivation of the optical nerve causes the deficiency in the sensory link, and disordered balance. It was shown by the comparative analysis of stabilograms.

After the treatment, the muscular strength increased, and the pain syndrome disappeared. It allowed normal distribution of load to both feet, a decrease in migration of the pressure center in the frontal and sagittal plane. The values of stabilometrics became statistically normal. We can observe the full clinical and stabilometric parallel: the patients did not show any clinical signs of flaccid paresis on the side of the injury. These signs were absent in stabilometrics. The result was clear and expected. The more interesting thing is the analysis of changes in stabilometric values in the groups.

The patients of the first group with S1 root compression showed a decrease in the square of the statokinesiogram and deviations in the frontal plane, i.e. the analyzed values corresponded to the statistical norm. When standing with opened eyes, the positive changes were more intense than in standing position without vision control. In the last case, the deviations in the sagittal plane increased a little, resulting in increasing Robmerg’s coefficient. We associate this fact with higher importance of optical entry for controlling vertical posture due to incomplete formation of a new postural stereotype. Considering the fact, the study was conducted on the tenth day after surgery, it relies upon final formation of a new postural stereotype.

The patients of the second group with L4-5 root compression showed the further decrease in the square of the statokinesiogram within the limits of statistical norm due to decreasing deviations in the sagittal plane as a sign of increasing stability of vertical posture and disappearance of manifestations of force paresis. Deprivation of optical entry in these patients causes an increase in the square of migration of the pressure center and deviations in the frontal and sagittal planes, not only in comparison with opened eye standing position, but also in comparison with the similar examination before surgery. Therefore, a role of optical entry for vertical posture control increased in these patients.

Comparing the time trends in values of stabilometrics in both groups of patients, one can suppose that a defect is removed faster in the executive (motional) segment. After disappearance of root compression within 10 days, the postural regulation restores almost completely. When the cause of the defect was the sensory link (to a higher degree), the full recovery was not achieved within 10 days.

The conducted study showed that the surgical treatment, which is initiated within 1-1.5 months after onset of the disease, leads to fast and complete recovery. Possibly, the success of treatment depends on the fact that trophic changes do not appear within such short time intervals, as well as persistent pathologic postural and locomotor stereotypes.

CONCLUSION

The surgical treatment of compression radicular syndromes of lumbar osteochondrosis causes the fast and full clinical recovery. At the same time, the vertical posture recovers. The completeness of recovery of postural regulation depends on compression of specific roots.

S1 root compression shows more intense disorders of postural regulation with increasing square of the statokinesiogram and deviations in the frontal plane.

L4-5 root compression is not accompanied by any evident deviations from normal values of the statokinesiogram in standing position with opened eyes, but it causes a significant disorder of regulation of posture when eyes are closed.

Compression correction leads to almost full recovery of postural regulation in standing position with opened eyes within 10 days after treatment. Deprivation of optical entry does not cause any significant decrease in posture of patients with S1 root lesion, but patients with L4-5 root lesion do not demonstrate the persistent vertical position in these conditions.

Information on financing and conflict of interests

The study was conducted without sponsorship. The authors declare the absence of any clear or potential conflict of interests relating to publication of this article.