scheuermann s disease ( juvenile kyphosis dorsalis ) is a structural kyphosis of the thoracic spine initially described by scheuermann in 1921 .
it occurs commonly in adolescents ( 0.48.3% of the general population ) and in most cases is characterized by minimal deformity and few clinical symptoms .
the purpose of the present paper is to present the case of a patient with scheuermann s disease and severe neurological deficit due to a thoracic disc hernia at the level of kyphos , to review the literature and compare with previously published similar cases .
he had gradually developed a gait disorder and bilateral numbness of lower limbs in the past 5  months . during that period
he was unable to walk and a week before his admission he developed spastic paraplegia .
he had a muscle strength of grade ii according to the medical research council ( mrc ) scale .
a barely detectable contraction could be seen below the knees by palpation over the muscles ( m1 on the mrc scale ) .
knee and ankle reflexes were brisk bilaterally , clonus was present in both ankles as well .
light touch and pin prick sensation were diminished over both lower limbs and absent from the knees downward . rectal tone and sensation while urinating were decreased .
plain radiographs of the spine in standing position revealed anterior wedging of more than 5 of several adjacent vertebrae ( t7:12 , t8:14 , t9:17 , t10:15 ) at the apex of the kyphosis and vertebral endplate irregularities .
the thoracic kyphosis from t5 to t12 measured 66 ( fig .  1 ) .
a magnetic resonance imaging scan revealed thoracic disc heniation with spinal cord compression at t8t9 level ( apex of the kyphosis ) .
the intervertebral spaces from t6 to t10 were also very narrow and the vertebral bodies had an anterior wedging ( figs .  2 , 3 ) . 

1a , b anteroposterior and lateral radiographs of the thoracic spine in standing position , at the time of admission .
2a , b magnetic resonance imaging scan revealed thoracic disc herniation with spinal cord compression at t8t9 level ( apex of the kyphosis)fig . 
3three - dimensional reconstruction computed tomography of the thoracic spine preoperatively a , b anteroposterior and lateral radiographs of the thoracic spine in standing position , at the time of admission .
the thoracic kyphosis from t5 to t12 is 66 a , b magnetic resonance imaging scan revealed thoracic disc herniation with spinal cord compression at t8t9 level ( apex of the kyphosis ) three - dimensional reconstruction computed tomography of the thoracic spine preoperatively surgical treatment was decided based on the severity of the neurological deficit .
a right seventh rib transthoracic approach to the spinal column was performed followed by decompression at t8t9 level .
we performed an anterior fusion using plate , screws , an interbody titanium cage and also a posterior fusion from t6 to t12 using a double - rod multihook and transpedicular screws segmental instrumentation system .
bone grafts were applied between t8 and t9 and intertransversaly from t7 to t10 ( fig .  4).fig . 
note the anterior and posterior spinal fusion a , b postoperative anteroposterior and lateral radiographs of the thoracic spine .
note the anterior and posterior spinal fusion postoperatively the patient had a surprisingly rapid improvement of the neurological deficit .
four weeks after the operation he could walk steadily and 2  months later his neurological examination was entirely normal . at 2  years
follow - up the patient had a normal gait , he was symptoms free and there was no increase of the spinal deformity .
scheuermann in 1921   described a condition , which he called juvenile dorsal kyphosis , distinguishing it from the more common postural kyphosis .
scheuermann proposed that the kyphosis resulted from avascular necrosis of the ring apophysis of the vertebral body .
schmorl suggested that the vertebral wedging was caused by herniation of disc material into the vertebral body ( schmorl s nodes ) .
according to ippolito and ponseti   a biochemical abnormality of the collagen and matrix of the vertebral endplate cartilage may be another contributing factor .
bradford et al .   claimed that osteoporosis may be responsible for the development of scheuermann s disease .
mechanical factors and repetitive trauma have been also considered to play a significant role in the appearance of the disease .
case reports in monozygotic twins support the theory that there is also a genetic contribution . in conclusion ,
the criteria for the diagnosis of scheuermann s disease are : ( 1 ) more than 5 of wedging of at least three adjacent vertebrae at the apex of the kyphosis , ( 2 ) endplates irregularities and ( 3 ) a thoracic kyphosis of more than 45 .
our patient had typical roentgenografic features of scheuermann s disease and his kyphosis was 66 from t5 to t12 .
neurological complications in scheuermann s disease are rare [ 24 , 7 , 11 , 15 , 18 , 21 , 24 ] .
three different types of neural compression have been reported : ( 1 ) extradural spinal cyst , ( 2 ) compression of the cord at the apex of the kyphos and ( 3 ) disk hernia at the apex of the kyphos . to the best of our knowledge
only 20 cases fall in the last category [ 24 , 8 , 12 , 14 , 17 , 2124 ] .
table  1cases of scheuermann s disease causing spinal cord compression as the result of thoracic disc herniationreferenceslevelage / sexfindingsappro achprocedureresults ( follow up)muller t1040 mparaplegianot reportednot complete recoveryvan landingham t7t8t917 mspastic paraparesis , no sphincter dysfunctionpt7t9 laminectomycomplete recovery ( 4 months)roth et al .
t9t1061 mspastic paraparesispt9t10 laminectomyparaplegiaturinese and raven t5t7t816 mspastic paraparesis , sphincter dysfunctionbed rest , minerva jacketcomplete recovery bradford and garcia t7t816 mspastic paraparesispt7t9 laminectomyresidual hypereflexia(120  months ) ryan and taylor t8t918 mspastic paraparesistt8t10 partial vertebrectomy , anterior spinal fusionspastic paraparesis(36  months)yablon et al .
t7t829 mspastic paraparesis , sphincter dysfunctionct / tt7t8 discectomy and fusioncomplete recovery ( 14  months)lesoin et al .  
( six cases ) t9t1049 fmonoparesis ( left)pt8t10 laminectomynot complete recovery ( 12  months)t8t955 fspastic paraparesistt8t9 discectomysmall motor deficit ( 8  months)t11t1261 mmonoparesis ( right)pposterior spinal fusionnot complete recovery ( 10  months)t8t927 mlower back pain , babinski s sign ( right)plt8t9 discectomy , t7t10 posterior spinal fusioncomplete recovery ( 3  months)t8t930 mlower back pain , slight motor deficit ( left)plt8t9 discectomy , t8t9 posterior spinal fusioncomplete recovery ( 3  months)t8t935 mspastic paraparesisplt8t9 discectomy , t8t9 posterior spinal fusionsmall motor deficit ( 3  months)bohlman and zdeblick   ( two cases)t11t12t12l138 fmonoparesis . back and
leg pain ( for 16  years)ctt11l1 discectomy and fusioncomplete recovery ( 36  months)t8t925 fback and leg pain ( for 7  years)tt8t9 discectomy and fusionsignificant pain relief ( 26  months)stambough et al .
t6t7t821 mspastic paraparesistt6t8 discectomy , anterior spinal fusion complete recovery ( 24  months)bhojraj and dandawate   ( three cases)t11t1216 mspastic paraparesis , urinary hesitancypt10t12 laminectomy , posterior interbody fusion complete recovery ( 36  months)t12l124 mspastic paraparesis , urinary hesitancypt12l1 laminectomy , posterior interbody fusioncomplete recovery ( 24  months)t11t1216 fspastic paraparesispt11t12 laminectomy , posterior interbody fusiontransient worsening postoperatively , subsequently complete recovery ( 15  months)chiu and luk t11l235 fspastic paraparesistt11l2 discectomy , spinal fusion small motor deficit ( 24  months)this report ( 2005)t8t914 mrapidly progressive spastic paraparesis , finally spastic paraplegiatt8t9 discectomy , anterior fusion , t6t12 posterior fusioncomplete recovery ( 25  months)m male , f female , p posterior , t transthoracic , ct costotransversectomy , pl posterolateral cases of scheuermann s disease causing spinal cord compression as the result of thoracic disc herniation m male , f female , p posterior , t transthoracic , ct costotransversectomy , pl posterolateral despite the fact that this condition has a uniform sex distribution [ 15 , 20 ] , only 6 of all 20 cases were female . males with scheuermann s disease are at greater risk for the development of spinal cord compression in the second decade of life [ 1 , 15 ] .
this is in agreement with our case ( male , 14  years old ) .
this difference between the sexes is probably due to the fact that males have more longitudinal spinal growth than females and their maximum growth in trunk length , as well as the maximum deformity of the kyphosis , occurs about 2  years later . in all cases
in which the degree of deformity was reported , the average angle was only 56.3. the severity of the neurological complications had no obvious correlation with the magnitude of the deformity [ 11 , 18 ] . in our case
.   found that in 43 cases with neurological deficits secondary to spinal deformity ( what ever the etiology ) the average angle of kyphosis was 95. he suggested that the greater the angle of kyphosis , the greater the risk of neurological impairment .
neurological complications are less likely to occur when the deformity is present over a large number of segments , instead of sharply angular deformities .
it is interesting that a relatively small disc herniation such as in our case produces such a major neurological deficit .
factors that may influence the onset of cord compromise are the tenuous vascularization and the relatively small canal diameter of the thoracic cord . additionally , in young patients the disc material is not degenerated and can act as a solid mass .
bradford and garcia   suggested that the high incidence of schmorl s nodes in scheuermann s disease can prevent disc herniation by decompressing the disc space . in our case
there were no schmorl s nodes either at this level or at any other level .
surgical treatment is indicated in the cases of scheuermann s disease with acute cord compression and generally combines anterior release with posterior instrumentation and fusion .
a posterior decompression is ineffective because the compressive force is acting from the front [ 11 , 13 , 15 , 18 ] .
although some authors have advocated posterior laminectomy and decompression , patterson and arbit   showed that 45% of patients undergoing laminectomies for thoracic disc herniations either had no relief or deteriorated .
for the 20 reported cases with thoracic disc herniation and scheuermann s disease six patients were treated with anterior spinal fusion , four patients with laminectomy , four with posterior spinal fusion , three patients with interbody fusion and pedicular screw plate fixation and one patient was treated with discectomy without spinal fusion .
only one patient was treated conservatively with bed rest and minerva jacket without any decompressive surgery . in one case  
the treatment was not reported . if a significant or progressive kyphosis , i.e. 55 or more exists , a combined posterior spinal fusion and instrumentation should be considered [ 18 , 21 ] . due to the age of the described patient and to the degree of kyphosis we performed discectomy , decompression , anterior and also posterior fusion using a double - rod multihook and transpedicular screws segmental instrumentation system .
the majority of the reported cases had good results . in 10 out of 20 cases the patients had complete recovery while only in one case the final outcome was paraplegia .
our patient had an excellent result with complete recovery in 3  months . at the final follow - up
2  years postoperatively , he is neurologically entirely normal and the spinal fusion is solid .
spastic paraparesis was the most common symptom in all cases but neurological symptoms were not so severe to result in paraplegia .
it seems that when symptomatic compression of the spinal cord occurs , surgery is the best option .
thoracic disc herniation is an extremely rare complication of scheuermann s disease , resulting in cord compression and marked neurological deficit , most commonly in young patients .
this rare form of spinal cord compression once demonstrated , should be treated as soon as possible with surgical decompression and stabilization of the spine anteroposteriorly .
 we present the case of a 14-year - old male with scheuermann s disease and significant neurological deficit due to thoracic disk herniation at the apex of kyphosis . 
 he was treated with an anterior decompression , anterior and posterior fusion in the same setting using plate , cage and a segmental instrumentation system . 
 the patient had an excellent outcome with complete neurological recovery . 
Introduction
Case report
Discussion
Conclusion