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rthopaedics & Traumatology: Surgery & Research (2013) 99S, S140—S149

Available online at

www.sciencedirect.com

EVIEW ARTICLE

ound and angular kyphosis in paediatric patients

. Miladi

ervice de chirurgie orthopédique Necker-Enfants malades, 149, rue de Sèvres, 75014 Paris, France

Accepted: 24 November 2012

KEYWORDSRound kyphosis;Angular kyphosis;Postural kyphosis;Developmentalkyphosis;Scheuermann’sdisease;Strut bone grafts;Posteriorepiphysiodesis;Vertebral

Abstract Structural kyphosis is a posterior convex deformity of the spine that may appearin childhood then worsen with growth, most notably during the pubertal growth spurt. Theabnormal curvature may be smooth, defining round kyphosis, or may display a sharp angularpattern. Angular kyphosis is the more severe of the two forms. The main causes of round kypho-sis are postural kyphosis and Scheuermann’s disease. The spontaneous outcome is favourable,and round kyphosis is well tolerated in adulthood. The treatment relies on orthopaedic meth-ods in the overwhelming majority of cases. Surgery is reserved for severe rigid kyphosis inolder children and for kyphosis responsible for refractory pain or neurological deficits. Surgicaltreatment carries a non-negligible risk of neurological, gastrointestinal, mechanical, and septiccomplications, which should be explained clearly to the family. Advances in contemporary pos-terior instrumentation have considerably limited the indications for anterior approaches. Manyconditions may cause angular kyphosis, whose greater severity is related to a greater potential

osteotomies for progression and neurological impairment. Clinical investigations are in order to identify thecause and to plan the surgical strategy. Early surgery may be indicated, via a combined ante-rior and posterior approach. Anterior strut grafting, anterior or posterior osteotomies, or evenvertebral column resections may be necessary to correct a major deformity.© 2012 Published by Elsevier Masson SAS.

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yphosis is a common reason for visits to paediatricrthopaedic clinics. The widespread belief among paediatri-ians and primary-care physicians that kyphosis is a benigneformity may lead to delays in obtaining specialised careor patients with progressive deformities.

Kyphosis is a symptom whose clinical features vary withhe underlying aetiology. Establishing the diagnosis and iden-

ifying the cause is therefore crucial to ensure that optimalreatment is provided.

E-mail address: l.miladi@nck.aphp.fr

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877-0568/$ – see front matter © 2012 Published by Elsevier Masson SASttp://dx.doi.org/10.1016/j.otsr.2012.12.004

efinition

yphosis is a marked curvature of the spine in the sagittallane, with a posterior convexity. Some degree of kyphosis isormal at the thoracic and sacral spinal segments. Accordingo the Scoliosis Research Society classification system, theurvature in the sagittal plane is normally smooth and com-rised between 20◦ and 45◦. In a recent French and Canadiantudy in 341 normal individual, the mean thoracic kyphosis

ngle in children was 44◦ [1].

Physiological kyphosis is crucial to the sagittal balancef the spine, which has generated interest among manyesearch groups in France and elsewhere [2,3].

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Round and angular kyphosis in paediatric patients

Anatomic patterns of kyphosis

Kyphosis exists as two distinct types, round and angu-lar. Two other patterns that deserve individualization arekyphosis associated with scoliosis, whether hyperrotatoryor junctional, and olisthetic kyphosis; their treatment is acomponent of the overall management of the underlyingcondition and, consequently, they will not be discussed inthis conference.

Round kyphosis

Round-back is the most common and best tolerated patternof kyphosis and is often overlooked. There is a large-radiussmooth curvature involving a large number of vertebrae. Themost common location is the thoracic or thoraco-lumbarspine. Most patients have no other abnormalities. Roundkyphosis is usually flexible and reducible during childhoodbut can evaluate to a rigid deformity during adolescence.

Angular kyphosis

Angular kyphosis is far more conspicuous, regardless of itslocation, as a sharp angle involving a small number of verte-brae disrupts the normal spinal curvature. Angular kyphosisis less frequent but more serious than round kyphosis. Pro-gression may occur during growth and prompt treatment isin required.

Angular kyphosis may be stable or unstable

In stable angular kyphosis, the abnormality involves a smallnumber of vertebrae exhibiting severe deformities, as wellas the intervening disks, which may be more or less com-plete depending on the cause. The capsules, ligaments,facet joints, and posterior part of the vertebral body areintact.

Unstable angular kyphosis may be caused by trauma orcongenital deformities. The risk of neurological compromisein this form of kyphosis is of concern.

Congenital kyphosis is related to severe local and regionalvertebral malformation that must be diagnosed at birth. Ver-tebral hypoplasia or aplasia results in loss of spinal alignmentdue to an abrupt step-off between two vertebrae, with focalkyphosis that is often very marked (Fig. 1).

Post-traumatic kyphosis is also a severe deformity thatinvolves the three columns of the spine. This form ofkyphosis occurs after a high-energy trauma and requiresimmediate treatment.

Clinical work-up

The clinical interview collects important information such asthe date of onset of the deformity, whether progression hasoccurred over time, the presence of pain, the treatmentsused to date, and any other health problems in the patient

or family.

The patient should be examined undressed in the stand-ing position, or the seated position if needed, then bentforward. The spine should be assessed from the front, back,

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igure 1 Angular thoracolumbar kyphosis with dislocation in neonate.

nd sides. The shape of the kyphosis should be recorded, asell as whether scoliosis is present also. Complete disap-earance of the deformity when the child is asked to standp straight indicates postural kyphosis or simple slouching.

The severity of the deformity is assessed by measuringhe sagittal distances from the plumbline of C7. The C7lumbline is normally tangent to T6 and S1 and the cervicalnd lumbar distances are equal to about 3 cm. These twoistances are increased in patients with kyphosis, in whomhe C7 plumbline is no longer tangent to the sacrum.

Pelvic parameter should be evaluated, as well as lowerimb alignment, i.e., the presence of overextension or per-anent flexion of the hips or of permanent flexion of the

nees. Reducibility of the kyphosis can be evaluated by sus-ending the child or having the child lie supine on a bolsterlaced under the apex of the deformity.

A detailed neurological evaluation is mandatory. Care-ul attention should be given to the deep tendon reflexes;uperficial abdominal reflexes; and presence of hypertonia,ensory abnormalities, or altered sphincter function. Thekin should be examined for café-au-lait spots and midlinebnormalities (tuft of hair, angioma, lipoma, or coccygealimple). Joint laxity should be looked for. Any facial abnor-alities should be recorded, as well as hydrocephalus, footeformities, and acromegaly.

nvestigations

n patients with marked kyphosis, full-length antero-osterior and lateral radiographs of the spine should bebtained in the upright position. The external auditoryeatus and femoral heads should be visible. Low-dose radio-

raphs obtained using the EOSTM system enable a good

nalysis of overall sagittal balance.

A lateral radiograph obtained under traction or with theatient lying supine on a bolster placed under the apexf the curvature provides information on the reducibility

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f the deformity. A determination of bone age (on a handadiograph) indicates how much growth remains to occur.

Magnetic resonance imaging of the spinal cord and spinellows an assessment of the cervico-occipital junction;pinal canal diameter at the apex of the deformity; andmpingement on the spinal canal of bone structures, discaterial, or tumour tissue. Spinal cord structure can be

ssessed and syringomyelia or congenital malformations ofhe spinal cord identified. An intra- or extra-canal tumourr dural ectasia should be looked for.

Computed tomography of the spine provides additionalnformation on any bone abnormalities antedating or causedy the kyphosis. Three-dimensional reformation improveshe assessment of bone morphology and relationships andelps to plan the surgical strategy.

Depending on the cause and possible treatment options,ther specific investigations may be obtained, such as lungunction testing, urodynamic assessement, a somestheticvoked potential recording, an upper gastrointestinal con-rast study, a spinal cord arteriogram, echocardiography,ltrasonography of the kidneys, an intradermal tuberculinest, or other investigations.

rinciples of treatment

everal orthopaedic and surgical treatments are availablend the strategy should be tailored to each individualatient.

rthopaedic treatment

rthopaedic treatment is indicated for round kyphosis of lesshan 65◦ that is still reducible in a child who has at least 1ear of remaining growth. Orthopaedic methods may also besed in some patients with angular kyphosis, as a preliminaryr addition to surgical treatment.

Physical therapy to improve posture aims at strengthen-ng the trunk muscles and stretching the hamstring muscles.hysical therapy may serve to alleviate the pain.

Bracing is the mainstay of the orthopaedic treatment ofyphosis. The goal is to correct and to stabilise the defor-ity. The brace is effective if it increases the flexibility of

he deformity and decreases the curvature by more than 15◦.he Milwaukee brace and the kyphosis bivalve brace are theost widely used devices in patients with kyphosis. A castay be fashioned to correct a marked and rigid kyphoticeformity before the use of a brace or to ensure postop-rative immobilisation after epiphysiodesis in a young child.hen there is no instability or risk of spinal cord compres-

ion, the preferred approach in patients with severe andarkedly rigid kyphosis is gradual correction of the defor-ity to facilitate the surgical treatment, decrease the risks

f surgery, and improve post-surgical outcomes.

urgical treatment

he surgical treatment of severe kyphosis, most notably inngular forms, can include two steps, one via an anteriornd the other via a posterior approach.

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Figure 2 Anterior strut grafting with tibial bone.

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trut grafting is used in patients with angular kyphosis. Tibialtrut grafts are implanted in a palisade configuration fromack to front (Fig. 2). The concavity of the deformity is thuslled with bone, producing a construct of good mechanicaltability.

In patients with round kyphosis, inlay grafting with theib removed in the surgical approach can be performed.fter excision of the discs, a longitudinal groove is fashionedlong the lateral aspect of the vertebral bodies and the ribraft is then implanted in the groove. For patients who haverreducible kyphosis with anterior fusion (kyphosis due toongenital defects, infection, or previous surgery), one orore anterior vertebral osteotomies may be needed to dis-

upt the fusion bridges and allow reduction of the deformity.n marked angular kyphosis with spinal cord compression,ecompression or even spinal cord transposition may beeeded before bone grafting can be performed. Finally, thenterior approach can be performed by video-assisted tho-acoscopic surgery to minimise morbidity and improve theosmetic outcome [4].

osterior surgery

ne option is posterior epiphysiodesis, in which the neu-al arches at the apex of the curvature are fused to ensureradual correction of the kyphosis as growth of the anteriorpine proceeds. Epiphysiodesis can be performed in childrenounger than 5 years who have angular kyphosis.

Posterior arthrodesis is used in combination with instru-entation that provides long coverage, preferably with

ooks in the proximal half and screws in the distal half. Cor-

ection is achieved either via a lever manoeuvre performeduring insertion of the rods and completed by compres-ion on either side of the apex of the deformity or vian situ bending of the rods [5]. In older children with very

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Figure 3 Kyphosis due to Scheuermann’s disease: a: 14-year-od

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Round and angular kyphosis in paediatric patients

rigid deformities, osteotomies of the fused neural archesor transpedicular osteotomies can be performed before theinstrumentation step. Advances in posterior instrumentationhave been reported to allow vertebral column resection viathe posterior approach alone to achieve single-stage, tar-geted, and focalised correction of severe spinal deformities[6]. The most widely used implants are hooks proximally andpedicular screws distally. However, surgeons are increas-ingly using screws for the entire construct. Metal wires orpolyester bands may be appropriate in some cases, as wellas plates or anterior spacers combined with bone grafts inthe event of vertebral column resection. The choice dependson each individual case and on the habitus of each surgeon.

After vertebral arthrodesis with instrumentation, earlycomplications include pulmonary, neurological, gastroin-testinal, infectious, and mechanical complications. Delayedcomplications consist of non-union, implant fractures, lossof correction, junctional kyphosis, and late osteoarthritisunder the fused segment.

Aetiologies and therapeutic indications

Kyphosis can occur in a large number of conditions. Withoutattempting to provide an exhaustive list, we will discuss themain causes of kyphosis, with the corresponding treatmentoptions.

Round kyphosis in children

Children may present with postural kyphosis or simpleslouching. The deformity can be corrected voluntarily by thepatient or disappears spontaneously in the supine position.The paediatrician or family physician should recommendproper posture while sitting, together with regular sport-ing activities. A physical examination should be performedevery 6 months and radiographs once a year to enableearly referral, if needed, to a rehabilitation physician ororthopaedic surgeon. If the deformity persists or worsens,the orthopaedic surgeon starts treatment with a Spine-Straight device or a night time brace.

Developmental kyphosis is a common cause of kypho-sis. Scheuermann’s disease is the most common form [7]and affects 4 to 8% of all children, with a predominance inboys [8,9]. The deformity is usually located at the thoracicspine (type 1); thoraco-lumbar and lumbar (type 2) formsare far less common. The cause of Scheuermann’s diseaseis unclear. Abnormal terminal ossification of the vertebralbodies results in vertebral wedging in type 1 Scheuermann’sdisease. In type 2, which affects the thoraco-lumbar or lum-bar spine, intra-osseous disc herniation may occur, withoutwedging. The deformity may be associated with persistentpain. In a tiny minority of very severe forms, neurologicalsigns may develop.

Radiographs show irregular endplates, wedging of at leastthree adjacent vertebral bodies with marginal impaction,and geodes known as Schmörl’s nodes due to the herniationof disc material into the abnormally fragile vertebral bone.

Selection of the best treatment depends chiefly on the ageof the child, the rigidity of the deformity, the location andnumber of involved vertebras, and presence of refractorypain. Type 2 disease, affecting the thoraco-lumbar or lumbar

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pine, usually produces moderate angular deformities but isore often responsible for pain related to intra-osseous disc

erniations. Orthopaedic management is the rule. In a fewases, neurological symptoms may arise, requiring surgeryo release the spinal cord followed by posterior fusion withnstrumentation. In type 1 disease affecting the thoracicpine, the deformity is rarely marked in early childhood ands always flexible and amenable to orthopaedic treatment.s soon as the curvature exceeds 50◦, full-time use of a brace

s in order. A thoracic-lumbar-sacral orthosis or Boston braceas been advocated instead of a Milwaukee brace [9]. Phys-cal therapy may be used in addition to bracing but is neverufficient to correct an established kyphotic deformity.

In the US, the recommended duration of orthopaedicreatment is 18 months. We prefer to continue the treat-ent until growth is complete, to avoid a recurrence of theeformity (Fig. 3a and 3b) [9,10]. There is widespread agree-ent that orthopaedic therapy is effective in adolescentsith flexible kyphosis or a Risser stage lower than 3; theilwaukee brace is often poorly accepted by adolescentsnd can be replaced by a kyphosis bivalve brace [10]. Inigid deformities, a series of corrective casts may be usefulnitially.

Studies have reported 10◦ to 20◦ of loss of correctionfter orthopaedic treatment discontinuation in at least 30%f cases [8].

The indications for surgical treatment are not clearlyefined in the literature [11]. In most English-language pub-ications, the criteria used to indicate surgery were a greaterhan 70◦ curvature in kyphosis of the mid-thoracic spine,ocumented negative cosmetic and psychological effects,nd pain refractory to non-surgical therapy [9,12,13]. In

rance, the indications are more restrictive given the benignharacter and natural history of the deformity (Murray),s well as the risks associated with surgical management14,15]. Surgery is thus reserved for marked, rigid, painful

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Figure 4 Round kyphosis: a: 16-year-old boy (Risser 3); b:oi

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utcome at 19 years of age, 3 years after posterior fusion withnstrumentation from T1 to L2 (Risser 5).

eformities in older children and for patients with neurolog-cal manifestations.

In young children below Risser stage 2 or 3 with deformi-ies of at least 70◦, isolated posterior fusion is adequate. Inhis situation, the subsequent growth of the vertebral bodiess sufficient to fill the modestly sized anterior gaps createdy the correction of the kyphosis (Fig. 4a and b).

At the end of the growth period, posterior surgery

lone is being increasingly recognised as sufficient givenhe improvements made in the efficiency and strength ofast-generation segmental instrumentations. An additional

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L. Miladi

nterior step is reserved for patients with deformitiesreater than 100◦ or anterior bony fusion [12,16—18]. Thenterior step can be performed by video-assisted thora-oscopic surgery [4]. We advocate a preparatory phase inatients with deformities greater than 90◦, to test the gas-rointestinal and neurological tolerance of the correction10]. Anterior fusion is usually performed over a shorter seg-ent than posterior fusion, i.e., over five to seven discs,

sually two or three on either side of the apex. Any ante-ior ossifications must be completely excised. The posteriorusion should be sufficiently long and provide enough cov-rage to prevent the development of a secondary kyphoticeformity at the junction between the fused segment andhe unfused segment. We usually end the instrumentationistally at the vertebral body located just above the firstorizontal disk on the radiograph taken in hyperextension on

support or in the standing position. In the US, the fusions ended distally at the vertebra above the first disc thats open anteriorly and no attempt is made to decrease thengle below 50◦, in order to avoid spinal malalignment andostoperative junctional kyphosis [19].

Thus, the objective of surgery should consist not only inorrecting the kyphotic deformity, but also in restoring thelobal balance of the body by adjusting the amount of cor-ection to the sagittal parameters of the adjacent segments,t the neck, lumbar spine, and pelvis. A preoperative evalua-ion of these parameters on EOSTM images can prove valuableor estimating the amount of correction that is appropriate.

yphosis due to congenital malformations

yphosis may be caused by congenital defects in vertebral

irth or even prenatally (Fig. 5). Congenital kyphosis is usu-lly angular and progressive, as a growth imbalance occursetween the anterior and posterior portions of the abnormal

thoracic block vertebrae in a foetus.

Round and angular kyphosis in paediatric patients S145

Figure 6 Lumbar kyphosis due to an L2-L3 block vertebra: Figure 7 Angular kyphosis due to a birth defect at thethoraco-lumbar junction: a: at 15 years of age; b: outcome2 years after anterior separation osteotomies and posteriorfusion with instrumentation from T3 to L4.

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region. Consequently, closely spaced follow-up visits are inorder.

Bracing is reserved for small-angle deformities withlimited progression. However, bracing can also be used asan adjunct to surgical treatment.

During the growth period, the treatment indicationsdepend on the rate of progression of the deformity. Rapidprogression indicates a need for immediate surgery, partic-ularly in the case of angular kyphosis.

In children younger than 5 years, surgical posterior epi-physiodesis without instrumentation extending proximallyand distally one or two levels beyond the kyphotic spinal seg-ment is widely advocated and ensures gradual correction ofthe deformity as growth proceeds [20,21]. In children aged 7to 12 years, posterior arthrodesis with instrumentation overa short segment is indicated [22]. When the deformity wors-ens only during the pubertal period, posterior arthrodesiswith instrumentation and broad coverage is in order to cor-rect the deformity at the levels adjacent to the congenitaldefect. In some patients with anterior block vertebrae diag-nosed at an early age, anterior separation osteotomies canbe followed immediately by posterior compression fixationwithout fusion, at a very young age (Fig. 6a and b).

In older children who were not treated in time, surgeryinvolves anterior release and osteotomy followed by poste-rior correction and fusion with instrumentation (Fig. 7a andb).

In some patients with neglected block vertebrae orprogressive anterior vertebral ossifications responsiblefor completely rigid kyphotic deformities, transpedicularosteotomies via the posterior approach may be in order(Fig. 8a and b).

Anterior ‘‘desepiphysiodesis’’(i.e., excision of the bonybridge) has been suggested to restore growth between thevertebral bodies [23]. Lumbar and lumbosacral agenesisand congenital dislocation of the spine result in angular

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igure 8 Thoraco-lumbar kyphosis with progressive anteriorertebral ossifications: a: at 16 years of age; b: same patientfter transpedicular osteotomies and posterior fixation.

yphosis with luxation. Neurological impairments may beoted at birth or may develop later on. Consequently, aadiological evaluation must be obtained at first presen-ation. These forms of kyphosis are surgical emergencieshat require stabilisation by combined anterior and posteriorusion.

For kyphosis associated with spina bifida, there is gen-ral agreement that vertebral resection at the apex of theeformity should be followed by sliding posterior instrumen-ation without fusion, from the upper thoracic spine to the

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ifida: a: at 5 years of age; b: aame patient after vertebralesection and sliding instrumentation from T1 to the pelvis.

elvis, to maintain the correction while allowing growth ofhe spine (Fig. 9a and b) [24].

yphosis due to dysplasia

his group encompasses a very large number of conditionsssociated with a variety of aetiopathogenic mechanisms.

Round kyphosis may occur in a number of skeletal dys-lasias, as a result of abnormalities affecting either the boner the soft tissues. Abnormal bone fragility leads to a gradualccumulation of vertebral crush fractures at multiple levels,ausing kyphosis. Causes of bone fragility include osteogen-sis imperfecta, punctate epiphyseal dysplasia, idiopathicuvenile osteoporosis, and a number of metabolic diseasesuch as mucopolysaccharidosis. In soft-tissue diseases, mostotably those affecting the connective tissue, the kypho-is is due to excessive ligament laxity and long remainsexible and reducible. Examples of diseases responsible forxcessive laxity are Marfan syndrome and Ehlers-Danlos syn-rome. Orthopaedic treatment should be started early and issually effective in slowing the progression of the deformitynd, therefore, in obviating the need for surgery. How-ver, patients with severe deformities may require surgicalanagement. The posterior approach can be used alone in

yphosis due to soft-tissue disorders. When a bone diseases involved, in contrast, combined anterior and posteriorurgery is required, usually with postoperative immobilisa-ion in a cast or brace, as fixation in bone of poor quality mayot be sufficiently secure. In severe forms of osteogenesismperfecta, it may be necessary to protect the fixation-aterial anchoring sites by adding bands or metal wires

round the vertebral lamina or transverse processes.Angular kyphosis may be due to severe bone dystrophy

ffecting a limited number of vertebrae, for instance inype 1 neurofibromatosis. These unstable lesions carry a risk

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f neurological compromise. Stabilisation must be achievedsing circumferential fusion, with or without instrumenta-ion depending on the patient’s age [25]. In some formsf skeletal dysplasia such as Morquio syndrome or achon-roplasia, the dystrophy may predominantly affect a fewostrum-shaped vertebrae, producing an angular kyphoticeformity that may threaten the spinal cord, which islready jeopardised by the constitutionally narrow spinalanal. During the growth period, the treatment in moder-te forms relies chiefly on orthopaedic methods. In patientsith severe deformities or neurological compromise, ante-

ior vertebral fusion with tibial strut grafting followed byosterior fusion should be performed after gradual correc-ion of the deformity. Care should be taken to identifyny neurological manifestations such as increased deep ten-on reflexes or lower limb spasticity, which may indicatencipient spinal cord damage at the apex of the deformityFig. 10a—d) [26,27].

yphosis due to paralysis

yphosis may develop in patients with a variety of neurolog-cal conditions such as paraplegia due to trauma, a tumour,r myelitis; encephalopathies; central or peripheral neu-opathies; myopathies; and other diseases. The vertebralody deformities long remain modest and the kyphosis fairlyasy to reduce, even in advanced forms. The spinal collapses well corrected by bracing during childhood but surgeryust be performed in adolescence. The internal fixation

erves as an internal spinal guide and substantially improvesomfort of the patient and family. Distal forms of kyphosisay lead to compensatory thoracic lordosis that should be

aken into account during the correction to avoid inducingosterior malalignment of the spine. Because the musclesre paralysed, posterior fusion with instrumentation extend-ng to the pelvis must be performed, as generally advocatedn the literature (Fig. 11a and b) [28].

ost-traumatic kyphosis

cute traumatic injuries of the spine in children with orithout neurological manifestations should be treated byasting followed by bracing for at least 2 years if the defor-ity is moderate and stable and by anterior and/or posteriorxation in angular or unstable deformities, with spinal cordecompression if needed. There is a general consensus inhe literature that reduction and posterior fixation withoutrafting is the appropriate strategy in forms with limitedngulation [29].

When kyphosis occurs as a sequela, the spinal malu-ions require combined anterior and posterior surgery, asescribed above for kyphosis due to congenital malforma-ions.

yphosis due to infection

iscitis due to pyogenic bacteria or to the Koch bacillusay result in destruction of the disc and vertebral body,

hereby inducing kyphosis. At the early stages, conser-ative orthopaedic treatment combined with appropriate

Round and angular kyphosis in paediatric patients S147

Figure 10 Kyphosis in a boy with spondylometaphyseal dysplasia (Kozlowski type): a: at 14 years of age; b: same patient 2 yearsafter preparation by halo-pelvic traction, anterior strut grafting, andd: clinical appearance 2 years after surgery.

Figure 11 Paralytic kyphosis: a: 16-year-old with

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encephalopathy; b: same patient immediately after posteriorfusion with instrumentation from T1 to the pelvis.

pharmacotherapy may ensure satisfactory reconstruc-tion. Later on, however, the kyphosis tends to becomeirreducible.

Among infections, tuberculous discitis in young childrenis the most common cause of kyphosis, as several discs areusually involved. Spinal cord damage due to compression at

the apex of the deformity is exceedingly rare in children,even those with severe deformities, and often producesmanifestations only very late in the course of the disease.Initially, surgery is indicated in the event of spinal cord

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finally posterior fixation; c: clinical appearance before surgery;

ompression, which is usually due to an anterior epiduralbscess. Laminectomy is not indicated, as it fails to releasehe anterior compression and may induce severe spinal insta-ility. An anterior approach should be used to allow spinalord decompression, removal of the abscess, and strut graft-ng. Then, appropriate antibiotics should be given and thepine should be immobilised by a cast or by posterior fusionith instrumentation [30].

In most cases, however, in the absence of spinal cordompression or when the abscess is controlled by the antibi-tic therapy, posterior surgery alone may be sufficient. Athe stage of residual lesions, surgery may be needed in thevent of gradual progression of the kyphotic deformity or ofpinal cord complications.

In the absence of neurological complications, the treat-ent relies on anterior strut grafting combined withosterior fusion with instrumentation. Complete rest muste instituted as an emergency measure in patients witheurological manifestations. If the radiographs taken in theupine position on a support indicate some measure of flex-bility, gradual reduction of the deformity by traction onhe head in bed or by a lengthening cast usually improveshe neurological manifestations. Stabilisation of the spines then achieved by combined anterior and posterior fusion.f the kyphotic deformity is irreducible or traction has noffect or worsens the neurological symptoms, anterior spinalord decompression by vertebral resection is required whenhe neurological impairments are significant. This decom-ression procedure is the first step of anterior surgery andhould be followed by grafting and posterior stabilisation.

yphosis due to tumours

pinal tumours are rare in paediatric patients but can causerogressive kyphosis due to collapse of the anterior part of

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he spine, with preservation of the posterior vertebral wallor a variable period. Lateral or rotational displacements doot occur until the tumour involves or destroys the pediclend facet joints.

Any primary tumour or metastasis that destroys theseomponents of the spine can cause kyphosis. In Langerhansell histiocytosis, kyphosis may antedate the developmentf vertebra plana. Kyphosis in a patient with a spinal tumourhould always prompt an evaluation for potential instability,hich may lead to dural sheath compression at the apex of

he deformity.Thus, the local treatment of these tumours should take

nto account not only the need for correcting the malalign-ent (the kyphosis), but also the need for restoring theechanical strength of the anterior spine by interbody graft-

ng [31].

atrogenic kyphosis

xtensive laminectomy that is not followed by appropriateeconstruction and adequate postoperative immobilisationan result in instability of the posterior spine, whichnevitably causes progressive kyphosis. The preventionf kyphosis involves performing laminoplasty instead ofaminectomy and ensuring prolonged postoperative immo-ilisation by a brace. Combined anterior and posteriorrafting is usually needed [32,33].

Prolonged radiation therapy may decrease the strengthf the vertebral bone tissue, allowing the gradual develop-ent of a kyphotic deformity. This complication has become

xceedingly rare since the introduction of improved treat-ent methods for tumours. When surgery is performed

o treat radiation-induced kyphosis, the combination ofaraspinal muscle wasting and skin fragility may hinder cov-rage of the fixation material, whose prominence should beinimised. Anterior fusion in good-quality underlying bone

s required to compensate for the poor quality of the poste-ior fusion and fixation. The posterior fusion should extendar beyond the radiation field boundaries and the fixationaterial should be secured to good-quality bone.Strategic errors in the treatment of abnormal spinal

urvatures (excessively short construct or inappropriateositioning of the boundaries) may lead to the develop-ent of kyphosis at the junction between the instrumented

nd non-instrumented regions. In this case, further surgi-al treatment is needed to extend the construct. Iatrogenicyphosis located in the middle of a fusion zone is completelyrreducible. Surgical correction requires osteotomies of therevious graft, in one or more stages.

onclusion

yphosis is a common spinal deformity in children and maye either round or angular. Kyphosis may progress withrowth. Primary-care physicians should be able to estab-ish the early diagnosis of a deformity that is becomingtructural, to ensure the timely provision of treatment.

reatment may be in order at a young age or even on anmergency basis in patients with unstable deformities.

Surgical indications remain poorly standardised in olderhildren with round kyphosis. In this situation, surgery

[

L. Miladi

hould be reserved for severe forms responsible for pain,iven the many possible adverse events and the good toler-nce of the deformity in adulthood.

isclosure of interest

he authors declare that they have no conflicts of interestoncerning this article.

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