BrJ Sports Med 1996;30:356-358

CASE REPORTS

Posterior element pain in an adolescent schoolgirl

Mark E Batt, Nina Skattum, Blane K Chong, Jeffrey L Tanji

AbstractA case is presented of a transitionallumbosacral vertebra in an adolescentgirl, presenting with low back pain. Therewas no evidence of a pars interarticularisdefect. Careful assessment of children oradolescents presenting with low back painis important since back pain in this agegroup is usually caused by organic dis-ease.(BrJ Sports Med 1996;30:356-358)

Key terms: adolescence; low back pain; sports; lumbo-sacral defect

Low back pain is a common complaint ofyoung athletes. Most frequently seen in ath-letes involved with sports requiring repetitiveflexion, extension, and rotation, high inci-dences have been reported in dancers, divers,figure skaters, and gymnasts.'-2 Unlike adultathletes, in this age group low back paintypically results from posterior element pathol-ogy rather than disc or degenerative disease.2While many of these injuries stem fromoveruse, a proportion arises solely or in partfrom congenital spinal anomalies. These mayinclude spina bifida, spondylolysis, spondy-lolisthesis, and transitional lumbar vertebrae.Pars interarticularis defects are a well docu-mented cause of low back pain in adolescents,yet reports of low back pain due to other verte-bral anomalies are scant. This report is of a 14year old schoolgirl involved with gymnasticswho presented with posterior element backpain.

Case reportA 14 year old schoolgirl presented with a sixmonth history oflow back pain. She was other-wise in good health and dates the onset of herdiscomfort from physical education classesduring which she undertook a series of hyper-extension manoeuvres and sustained a fall.Pain was exacerbated by prolonged standingand interfered with activities of daily livingactivity. She was a recreational athlete, wouldswim as pain permitted, but otherwise cur-tailed involvement in school sports. Pain waslimited to her low back with no radiation,neurological symptoms, or bowel and bladderdysfunction. Past medical history was unre-markable and family history non-contributory.She had previously attended ballet classesbetween the ages of 8 and 10 years.

Physical examination revealed normal spinalcurvatures with no scoliosis or other deformity.Active range of spinal motion was complete;

however, she experienced left lower lumbardiscomfort with extension, rotation, quadranttesting, and left single leg hyperextension. Skinexamination was normal with no spasm or ten-derness. There was localised bone tendernessat the level of L5/S 1, more pronounced on theleft than on the right. Straight leg raise was 900and symmetrical, with a negative Lasegue test.Neurological testing of sensation, power, anddeep tendon reflexes were within normallimits. Provocative sacroiliac tests were normal.She was noted to be flexible with no specifichamstring, quadriceps, or hip flexor tightness.

Initial investigations included plain filmradiographs which showed unilateral lefthemisacralisation of L5 on S1 and left facetjoint sclerosis at L4/5 (fig 1). There was noradiographic evidence of a pars interarticularisdefect; however, a triple phase limited bonescan (with SPECT) revealed increased uptakein the superior portion of the left sacral wingsuggestive of a stress fracture (fig 2). In orderto further define the site of pathology a CTscan was performed which showed a transi-tional vertebral body at the L5 level with apseudoarthrosis of the left L5 transverse proc-ess with a left SI transverse process (figs 3 and4). A minimal L4/5 central disc bulge wasnoted.Her initial management had been relative

rest, avoidance of extension manoeuvres, and anon-steroidal anti-inflammatory agent. Fol-lowing the imaging studies she was prescribeda lumbosacral corset which she discontinuedbecause of discomfort and instead purchased asoft corset. Her symptoms gradually resolvedover three months, allowing progressive returnto activity, starting with swimming.

DiscussionThis case shows the importance of carefulassessment of children or adolescents present-ing with low back pain. Back pain in this agegroup is usually caused by organic disease andthe spectrum and distribution of pathology isdifferent from that in the adult population."Despite problems associated with sports injurysurveillance, the increased incidence of sportsrelated injuries are mirroring increasedparticipation.' Specifically, the incidence ofback injuries is increasing, particularly in thosesports requiring repetitive extension and rota-tion of the lumbar spine.'This case involved hyperextension gymnastic

manoeuvres during a physical education class.The relatively higher incidence of injuries duringphysical education classes and of nonorganised

Primary Care SportsMedicine Clinic,Department ofFamilyPractice, University ofCalifornia, Davis,School ofMedicine,Sacramento,California, USAM E BattN SkattumB K ChongJ L Tanji

Correspondence to:Dr Mark E Batt, Centre forSports Medicine,Department of Orthopaedicand Accident Surgery,Queen's Medical Centre,Nottingham NG7 2UH,United Kingdom

Accepted for publication16 January 1996

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Posterior element pain in an adolescent

Figure 3 Coronal reformation computerised tomographyof the lumbosacral spine showing enlarged transverseprocesses ofL5 bilaterally (arrows) with a leftpseudoarthrosis with the Si transverse process. Scleroticmargins of this articulation are present (arrowhead) butthere is no evidence of sacral trabecular disruption.

Figure 1 Plain film radiograph (AP oflumbosacralspine) showing hemisacralisation ofL5 on Si and leftfacetjoint sclerosis at this level.

Figure 2 AP delayed image of triple phase bone scanshowing increased uptake in the superior portion of the leftsacral wing (arrowed).

sports over organised team sport has previouslybeen noted and reflects the larger number ofparticipants.9 The site of pathology was theposterior spinal elements and this is typical forthis mechanism and age group. Of interest wasthe finding of a transitional lumbosacral verte-bra (TLSV) and the absence of evidence of apars interarticularis defect. Of the congenitallumbar spine anomalies, spondylolysis andspondylolisthesis are recognised causes of lowback pain, but not spina bifida or TLSV.'Whether or not TLSV are associated withincreased risk oflow back pain is in dispute and

Figure 4 Axial CT of the L51Si junction showing the leftpseudoarthrosis with no bony union. A joint line is visiblewith sclerotic margins (arrowhead).

this probably reflects the variable anatomy ofthese lesions.'0 Although their occurrence isrelatively common (4-7% of the population),relatively little is known about their biome-chanics and pathophysiology.1"c

In 1917 Bertolotti described the associationofback pain and a TLSV, the pain being attrib-uted to degenerative changes at that level.'2While arthritic changes at the TLSV may exist,other degenerative processes occur and aretypically found above the affected segment. Inpatients with back pain and a TLSV the occur-rence of a disc bulge or herniation, or spinal orroot canal stenosis is more common in the seg-ment immediately above the TLSV than at otherlevels. Typically, radiologically evident degenera-tive changes in pseudoarthroses do not provide apredictable localisation of symptoms."

In this case there was a left dysplastic L5transverse processes with a fibrous pseudoar-throsis producing a hemisacralisation of the L5vertebra. A minimal disc bulge was notedabove the hemisacralisation which was asymp-tomatic. The patient' s low back pain was bilat-eral, with clinical tenderness ipsilateral to the

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358 Batt, Skattum, Chong, Tanji

asymmetrical pseudoarthrosis. The asym-metrical morphology of this lesion and lack ofsolid fusion may have contributed to theproduction of symptoms at this level. Thiswould be consistent with the findings of Barzoet al, who showed that asymmetrical anomalieshave greater clinical significance,"3 and ofJons-son et al,' who did not encounter patients withbilateral anomalous articulations seeking helpfor low back pain.3The bone scan (fig 2) and SPECT studies

showed a focal area of increased uptake in thesacral wing ipsilateral to the left hemisacralisa-tion. This finding of a sacral bone stressreaction in association with a TLSV has notpreviously been reported. Typically sacral wingfractures occur in one oftwo patterns. The firstand more frequent is an insufficiency fracturein patients with osteopenia due to involutionalosteoporosis, radiotherapy, or prolonged ster-oid use.'s6 The second less frequently re-ported group occurs as a fatigue fracture inhealthy athletes or recruits following strenuousactivity."7 The exact nature of the stress injuryto the sacral wing in this case is conjectural.These findings may have been indicative ofaccelerated bone remodelling in the sacrum ofan adolescent performing exercises which,through the asymmetric TLSV, placed abnor-mal stress on the sacral wing. The sparselyincreased uptake on the bone scan was notaccompanied by trabecular changes on a CTscan of the sacrum, which was performedseven months after the onset of symptoms,suggesting that the lesion had not progressedto a true stress fracture. Specific provocativetests of the sacroiliac joints were negative,lending credence to the suggestion that thepseudoarthrosis was not the sole cause of hersymptoms. The final working diagnoses wereback pain in association with a TLSV (Bertol-otti 's syndrome) and an ipsilateral sacral wingbone stress injury.

She was treated in a corset to limit motion atthe TLSV; however, this was not tolerated andshe instead elected to use an elastic supportbrace. Her symptoms slowly improved allow-ing a return to swimming. The prognosis isunclear, but as many individuals with a TLSV

remain asymptomatic an optimistic outlook iswarranted for conservative management. Sur-gery in cases ofTLSV is recommended in veryselected cases and has a variable successrate."8 The bone stress injury involving theipsilateral sacral wing was not accompanied bytrabecular changes on CT scan and with restthis lesion should resolve. Future studies arerequired to compare the specific symptomsand signs referable from the different morpho-logical types of TLSV and investigate theirrelations to abnormal stress patterns in thesacrum.This material was presented at The 42nd Annual Meeting ofThe American College of Sports Medicine, Minneapolis, Min-nesota, June 1995.

1 Micheli Q, Wood R. Back pain in young athletes. Arch Pedi-atrAdolesc Med 1995;149:15--18.

2 Harvey J, Tanner S. Low back pain in young athletes. SportsMed 1991;12:394-406.

3 Jonsson B, Stromqvist B, Egund N. Anomalous lumbosacralarticulations and low back pain. Spine 1989;14:831--4.

4 Papanicolaou N, Wilkinson RH, Emans JB, Treves S,Micheli U. Bone scintigraphy and radiography in youngathletes with low back pain. Am J7 Radiol 1985;145:1039--44.

5 Garrick JG, Requa RK. Girls' sports injuries in high schoolathletics. JAMA 1978;239:2245--8.

6 Garrick JG, Requa RK. Injuries in high school sports. Pedi-atrics 1978;61:465-9.

7 Landry GL. Sports injuries in childhood. PediatrAnn 1992;21:165--8.

8 Maffulli N, Baxter-Jones ADG. Common skeletal injuries inyoung athletes. Sports Med 1995;19:137--49.

9 Zaricznyj B, Shattuck LJM, Mast TA, Robertson RV, D EliaG. Sports related injuries in school-aged children. Am JfSports Med 1980;8:318--24.

10 Tini PG, Wieser C, Zinn WN. The transitional vertebra ofthe lumbosacral spine: its radiological classification,incidence, prevalence and clinical significance. RheumatolRehabil 1977;16: 180-5.

11 Elster AD. Bertolotti 's syndrome revisited -- transitionalvertebrae of the lumbar spine. Spine 1989;14:1373--7.

12 Bertolotti M. Contributo alla conoscenza dei vizi didifferenzazione regionale del rachide con speciale riguardoall assimilazione deel V lombare. Radiol Med 1917;4: 113--44.

13 Barzo P, Voros E, Bodosi M. Clinical significance oflumbosacral transitional vertebrae (Bertolotti syndrome).OrvosiHetilap 1993;134:2537--40.

14 Jones DN, Wycherley AG. Bone scan demonstration of pro-gression of sacral insufficiency stress fracture. Aust Radiol1994;38: 148-50.

15 Schneider R, Yacovone J, Ghelman B. Unsuspected sacralfractures Detection by radionuclide bone scanning. Am J7Radiol 1985;144:337--41.

16 Stroebel RJ, Ginsburg WW, McLeod RA. Sacral insuffi-ciency fractures: an often unsuspected cause of low backpain.JRheumatol 1991;18:117--9.

17 Volpin G, Milgrom C, Goldsher D, Stein H. Stress fracturesof the sacrum following strenuous activity. Clin Orthop1989;243:184--8.

18 Santavirta S, Tallroth K, Ylinen P, Suoranta H. Surgicaltreatment of Bertolotti s syndrome. Arch Orthop TraumaSurg 1993;112:82--7.

CommentaryI find this an extremely interesting case. I would, however, like to propose an alternative explana-tion for the imaging findings. Hemi-sacralisation of the lumbosacral junction is common andsymptomatic pseudoarthroses/impingement are also not rare. The ones I have personally seen inthe past do not look like the current CT images. Also, on the initial radiograph, sclerosis wouldhave been expected at that time at the site of impingement. The CT images performed sevenmonths after initial onset ofsymptoms show quite profound sclerosis and a barely perceptible lineacross the centre of the sclerotic band in the region of the lateral bar. Indeed, the appearances ofthe sclerosis and this barely perceptible line are much more akin to the appearances found else-where in the CT images of healing or healed pars defect. The current CT looks much more likethe latter than the former and therefore a partially healed stress injury across a lateral bar fromhemi-sacralisation would seem to be more likely. Such a stress injury could presumably occursecondary to the asymmetrical mobility of the lumbosacral junction. Whereas symptomatic pseu-doarthroses are not particularly uncommon, such a stress injury across the lateral bar of thehemi-sacralised vertebra would, I suspect, be exceptionally rare, which heightens the interest inthis case. I think, however, that considering the lack of sclerosis on initial radiograph and thebarely perceptible lucent line on delayed CT, that this latter diagnosis is more likely.

W W GIBBON

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