Download View PDF

Surgical staged treatment for moderate to severe adolescent cervical kyphosis
LIANG Lei, ZHOU Xu-hui, LIU Yang, GAO Rui, CHEN Hua-jiang, YANG Li-li,
SHI Sheng and YUAN Wen,
Department of Spine Surgery, Chang zheng Orthopaedics Hospital, the Second
Military Medical University, Shanghai 200003, China
ABSTRACT
Background: Adolescent cervical kyphosis refers to manifestation characterized by
loss of physiological cervical lordosis with involvement of multiple cervical vertebrae.
There is no standard treatment strategy for this disease, especially in the patients who
need surgical intervention. The aim of this study was to evaluate the surgical staged
treatment for moderate to severe adolescents cervical kyphosis.
Methods: A total of 28 adolescent with cervical kyphosis were retrospectively
assigned into following two groups according to the magnitude of kyphosis: moderate
group (n=17), the Cobb angle was 46.6 ± 4.8°. The surgical procedure was that skull
traction was first carried out for 5-7 days and then the anterior fusion and
instrumentation were performed. Severe group (n=9), the Cobb angle was 61.6 ± 4.8°.
The treatment strategy was that the anterior release were first performed, followed by
skull traction for 7-10 days, and then anterior fusion were performed. Radiographic
evaluation was performed postoperatively.
Results: Three days after surgery, the X-ray examination showed that the Cobb angle
was -8.9 ± 6.8° in the moderate group and -6.0 ± 6.3°in the severe group. The
deformed appearance was obviously corrected, with neck pain and neurologic
function improved significantly. Further magnetic resonance imaging (MRI) indicated
the physiology curvature of the cervical spine had been reconstructed.
Conclusion: Surgical staged treatment may be an ideal therapeutic intervention for
cervical kyphosis patients with a Cobb angle exceeding 35° in adolescents.
Key words: Cervical vertebrae, Kyphosis , Staged treatment, Adolescent
Cervical kyphosis seems a common disease in adolescents. While clinical
manifestations vary, the most common include a loss of segmental cervical lordosis,
decreased anterior vertebral height, joint dislocation and cervical spine instability,
cervical stenosis, and cervical degeneration, etc[1]. As the vertebral growth plate of an
adolescent is in the developmental stage, the correction of kyphosis is becoming a
challenging problem in the field of spinal surgery [1-3]. Recently, several researchers in
China have demonstrated that the posterior tangent angles and Cobb angles at
kyphosis are associated with the degree of spinal cord compression. When either of
the two angles exceeding 20°, compensatory for cervical spine reaches their limits.
Further deformity would result in aforementioned clinical manifestations of cervical
kyphosis so that therapeutic intervention is needed[4]. In this study, we focused on a
retrospective analysis of 26 adolescent cervical kyphosis patients with a Cobb angle
exceeding 35° and explored staged treatment for this disease.
METHODS
Clinical enrollment
From January 2005 to June 2010, 26 adolescent patients with cervical kyphosis
underwent treatment in the same hospital with 12 males and 14 females. Their ages
ranged from 13 to 18 years old with an average of 15.6 years old, and their course
ranged from 3 to 48 months with an average of 30.5 months. The patients all have
complainted of neck stiffness and pain. Some of the patients exhibited deformed
appearance and had difficulty in looking up. Physical examination indicated tendon
hyperreflexia of knee jerk in 24 patients, sensory disturbance in 22 patients, and a side
of deltoid muscle paralysis accompanied with decreased muscle strength of lower
limbs in 12 patients.
Lateral and dynamic cervical X-rays were all obtained prior to beginning treatment.
According to previous reports[5], the patients were divided into moderate (Cobb angle
35°-55°) and severe (Cobb angle > 55°) groups according to the magnitude of
kyphosis. There were 17 moderate patients in our study with a Cobb angle of
46.6°±4.8° and 9 severe patients with a Cobb angle of 61.6°±4.8°. Three-dimensional
CT reconstruction images showed a Luschka joint fusion were present in 18 patients.
Magnetic resonance imaging (MRI) analysis indicated spinal cord compression
present in all the 26 patients.
Surgery treatment
The surgical staged treatment was performed to each of the patients. The range of
anterior cervical fusion was determined by the angles between the posterior vertebral
body tangents measured from X-rays (Fig.1). All the operations are under general
anesthesia with intratracheal intubation.
For moderate patients, skull traction(3-5kg) was first carried out for 5-7 days,
followed by anterior cervical surgery. The patient was placed in a supine position to
expose vertebral bodies in the deformed region and anterior portion of intervertebral
discs. The anterior vertebral osteophyte and intervertebral discs were resected to the
longitudinal ligament and Luschka joint in both sides resulting in spinal cord
compression release. Each intervertebral space was distracted to restore physiological
curvature using a Caspar retractor placed on the vertebral screws. Then, an anterior
fusion was performed with an autologous bone graft, size matched Cage and internal
fixation.
For severe patients, the anterior release was first performed. Routinely, the anterior
vertebral osteophyte and intervertebral discs in the kyphosis region were removed to
the longitudinal ligament and Luschka joint in both sides. Skull traction was applied
postoperatively (1/10 body weight) in order to correct the deformity as much as
possible. Traction weight should be reduced appropriately in case neural symptoms of
limbs were aggravated. After 7-10 days, the anterior distracting and fusion was
performed through the original anterior approach.
Postoperative hormone, dehydration, prevention of infection and early rehabilitation
exercise were administered routinely. ALL the patients were suggested to ambulate
under the protection of cervical collars within one week. X-rays were taken to assess
the orthopaedic effect and success of the fusion. Pre- and postoperative symptoms,
neural functions and complications were also recorded.
Radiographic evaluation
All the X-rays were taken by a single imaging doctor and device. The imaging data
were input into the computer and analyzed using Photoshop CS4 software. Cervical
kyphosis angle was measured according to Cobb methods[6] and MRI analysis was
used to examine the spinal cord decompression effect.
Symptom and neural functions
The Visual Analogue Scale (VAS)[7] and Japanese Orthopaedic Association scoring
system (JOA)[8] were used to evaluate the pain and neural functions of the spinal cord
respectively.
Statistical analysis
Statistical analysis was conducted using the SPSS version 17.0 software (SPSS Inc.,
USA), and the results were measured by average ± standard deviation（ ±s）.The
t-test was used for comparisons between preoperative date and postoperative data of
Cobb angle, VAS and JOA scores. P-values less than 0.05 were considered
statistically significant.
RESULT
Three days after the surgery, X-ray showed that the Cobb angle has been significantly
improved from 46.6°±4.8° to-8.9°±6.8° in the moderate group (t=51.3，P<0．05), and
61.6°±4.8° to -6.0°±6.3° in the severe group (t=27.0，P<0．05) (Table 1) . In addition,
the deformed appearance was obviously corrected. In the moderate group, the VAS
scores were improved from 5.0±0.4 to 0.5±0.6 (t=49.3，P<0．05) and the JOA scores
were from 13.5±1.2 to15.6±0.9 (t=-12.3，P < 0.05). In the severe group, the VAS
scores were improved from 5.1±0.3 to 0.6±0.8 (t=24.2，P<0．05) and the JOA scores
were from 12.4±2.1 to 15.3±1.2 (t=-8.2，P < 0.05) (Table 2). Further MRI and 3D-CT
analysis indicated the physiology curvature of the cervical spine had been
reconstructed.
All the incisions in patients were healed. During the 12-18 months (mean15.6 months)
follow-up, no case of internal fixation and fusion failure was observed. The imaging
data of a typical case are shown in Fig. 2.
DISCUSSIONS
It is commonly believed that the sagittal axis passes through the posterior of C2 and
C7 vertebral bodies [8-9] and the lordotic angle should be around 15°[10]. Under normal
conditions, a less compressibility was loaded on a vertebral body and an intervertebral
disc, so that a smaller traction tension was born by the posterior structures (Luschka
joints, joint capsule, interspinal ligament, and ligamenta flava).Therefore, continuous
contraction tension of the posterior muscle is unnecessary to antagonize the gravity of
the head[11].
In an adolescent, the loss of balance between the anterior and posterior forces of the
neck due to some possible reasons may result in cervical physiology lordosis reducing
and the gravity of the skull moving forward. The centre of gravity of the head moving
forward makes the anterior vertebral body and intervertebral disk have to bear an
increased compression load, leading to the posterior ligament having to bear an
increased tension load in order to offer additional tension for maintaining mechanical
equilibrium in a sagittal plane[12-13].However, once the posterior cervical muscles are
too fatigued to antagonize a kyphotic deformity development effectively, the
deformity would be further exacerbated and form a vicious cycle[14-15].The
Hueter-Volkmann Law[16] suggested that abnormal stress interferes with the growth
and development of the vertebral endplate cartilage. Therefore, increased
compressibility stress burden on the vertebral body would restrain cartilage
osteoepiphysis growth and bring about wedging of the vertebral body and further
aggravate the kyphosis. In addition, narrowed intervertebral space, decreased cervical
intervertebral disc and anterior cervical height further accelerate kyphosis deformity
progression. Importantly, the patients are in a growth and development period, thus
the forementioned influence seems to be more significant for adolescents.
Presently, there isn’t a standard treatment strategy for cervical kyphosis in
adolescents[17-18]. In 1999, Abumi[19] et al classified a cervical kyphosis deformity into
soft and stiff types and believe that a posterior pedicle screw fixation systems,
combined with 360° osteotomies and anterior fusion could achieve the best correction
of cervical kyphosis. Stewart[20] et al suggested that the anterior correction surgery
could restore the biological characteristics of cervical vertebra by the max expansion
of the intervertebral spaces and increasing anterior column height. Recently, some
Chinese researchers suggested that the cervical kyphosis correction is a reverse
rotation process on the sagittal plain of vertebral bodies[21]. Based on these studies and
our experiences, we suggest that for adolescent cervical kyphosis patients, we should
pay more attention to a specific character in adolescents, evaluating the individual
situation and the influence on growth in long-term prognosis between different
treatments. It is necessary to institute a relatively personalized treatment strategy.
For the adolescent cervical kyphosis patients with Cobb angle exceeding 35°, a
surgical staged treatment was adopted in our study and a satisfactory therapeutic
effect was also achieved in early treatment. Further evaluation depends on a continued
follow-up. The continuous skull traction was maintained in order to correct the
deformity as much as possible before fusion in both groups, while the anterior release
was first performed in the severe group. Patients in the severe group are all belong to
the stiff type, which is characterized of vertebrae wedging at the apex, anterior
vertebral osteophytosis, Luschka joints fusion, and adjacent segment instability or
subluxation. We also found that tension of the anterior vertebral tissue increased when
passive stretching occurred in the front of the neck. These results are consistent with
recent studies of domestic scholars[22]. For moderate to severe deformed patients,
surgical staged treatment could make the vertebral artery and spinal cord adapt to the
spatial location gradually and minimize the complications such as nerve damage. In
addition, staged treatment could allow surgeons to observe the effect of treatment on
neural function. Once neurological dysfunction appeared or the patients could not
tolerate orthopedic treatment, traction can be terminated at once. Therefore, higher
security was also present in staged treatment compared with other anterior and
posterior surgery.
References
1. Daivajna S, Jones A, Hossein Mehdian SM. Surgical management of severe
cervical kyphosis with myelopathy in osteogenesis imperfecta: a case report.
Spine (Phila Pa 1976) 2005;30(7):E191-4. PMID:15803069
2. Albert TJ, Vacarro A. Postlaminectomy kyphosis. Spine (Phila Pa 1976)
1998;23(24):2738-45. PMID:9879099
3. Kaptain GJ, Simmons NE, Replogle RE, Pobereskin L. Incidence and outcome of
kyphotic deformity following laminectomy for cervical spondylotic myelopathy. J
Neurosurg 2000;93(2 Suppl):199-204. PMID:11012049
4. Fang JH, Zhou XH, Yuan W, Jia LS, Lu J, Yan WJ. Correlation between clinical
symptom and radiological measurement for cervical kyphosis [In Chinese].
Chinese Journal of Spine and Spinal Cord 2009;19(8):601-04.
5. Liang L, Zhou XH, Liu Y, Bai WS, Shen XL, Chen HJ, et al. Adolescent idiopathic
cervical kyphosis: grade and treatment [In Chinese] .Chinese Journal of
Orthopaedics 2011;31(5):413-16.
6. DD J. Application status of clinical efficacy score about of low back pain. Recent
Development of Osteopathic Medicine (Continuing Education teaching materials
of The Chinese medical association) 2004:55.
7. Ono K, Ebara S, Fuji T, Yonenobu K, Fujiwara K, Yamashita K. Myelopathy hand.
New clinical signs of cervical cord damage. J Bone Joint Surg (Br)
1987;69(2):215-9. PMID:3818752
8. Seng KY, Lee Peter VS, Lam PM. Neck muscle strength across the sagittal and
coronal planes: an isometric study. Clin Biomech (Bristol, Avon)
2002;17(7):545-7. PMID:12206947
9. Garces GL, Medina D, Milutinovic L, Garavote P, Guerado E. Normative database
of isometric cervical strength in a healthy population. Med Sci Sports Exerc
2002;34(3):464-70. PMID:11880811
10. Zdeblick TA, Zou D, Warden KE, McCabe R, Kunz D, Vanderby R. Cervical
stability after foraminotomy. A biomechanical in vitro analysis. J Bone Joint Surg
Am 1992;74(1):22-7. PMID:1734010
11. Katz JS, Wolfe GI, Burns DK, Bryan WW, Fleckenstein JL, Barohn RJ. Isolated
neck extensor myopathy: a common cause of dropped head syndrome. Neurology
1996;46(4):917-21. PMID:8780064
12. Bridwell KH, RL. D. The Textbook of Spine Surgery. Philadelphia: Lippincott
Williams & Wilkins 1997:972-80.
13. HA. P. Iatrogenic spinal deformities. The Pediatric Spine: Principles and Practice.
New York: Raven Press. 1995:101-19.
14. Zhou XH, Fang JH, Yuan W, Jia LS, Liu Y, Chi ZY et al. Surgical treatment
strategy for severe traumatic cervical kyphosis [In Chinese].Chinese Journal of
Trauma 2007;23(9):650-53.
15. Masini M, Maranhao V. Experimental determination of the effect of progressive
sharp-angle spinal deformity on the spinal cord. Eur Spine J 1997;6(2):89-92.
PMID:9209874
16. White AA, MM. P. Clinical biomechanics of the spine, 2nd. Philadelphia: JB
Lippincott 1990:318-21.
17. Yuan W, Liu Y, Chen DY, Xiao JR, Zhou XH, Chen XS, et al. Surgical treatment
for severe cervical kyphosis [In Chinese]. Chinese Journal of Orthopaedics
2007;27(9):671-76.
18. Liu Y, Yuan W. Recent Research And Development of cervical kyphosis. Chinese
Journal of Spine and Spinal Cord 2007;17(11):873-74.
19. Abumi K, Shono Y, Taneichi H, Ito M, Kaneda K. Correction of cervical kyphosis
using pedicle screw fixation systems. Spine (Phila Pa 1976) 1999;24(22):2389-96.
PMID:10586466
20. Stewart TJ, Steinmetz MP, Benzel EC. Techniques for the ventral correction of
postsurgical cervical kyphotic deformity. Neurosurgery 2005;56(1 Suppl):191-5;
discussion 91-5. PMID:15799810
21. Zhou XH, Fang JH, LS J. Clinical significance of cervical vertebral flexion and
extension spatial position alignment changes. Spine 2009;34(1):E21-26.
PMID:19127144
22. Fang JH, Jia LS, Zhou XH, Song LJ, Li X, Cai WH. Clinical assessment of rigid
cervical kyphosis and surgical approach selection [In Chinese]. Orthopedic
Journal of China 2010;18(13):1057-60.