Radiological manifestations of Reiter's syndromeard.bmj.com/content/annrheumdis/38/Suppl_1/12.full.pdf · spectrum of radiological manifestations. Although ... appendicular joints,

Ann. rheum. Dis. (1979), 38, Supplement p. 12

Radiological manifestations of Reiter's syndrome

WILLIAM MARTEL

From the University of Michigan Hospital, Michigan, USA

Reiter's syndrome (RS) presents with a broadspectrum of radiological manifestations. Althoughthere is an overlap with other connective tissuediseases134, 214, 221, 248, 286 certain features appear tobe characteristic, particularly when present incombination. This report concerns the radiologicalfindings in 36 patients with RS. They are comparedwith the radiological manifestations of rheumatoidarthritis (RA), ankylosing spondylitis (AS), andpsoriatic arthritis (PSA).

Patients and methods

Records of 36 patients were selected from the files ofthe department of radiology, University of MichiganMedical Center, on the basis of previously docu-mented positive radiological findings. The recordswere then reviewed to confirm the clinical diagnosisof RS. For the purpose of this study the diagnosticcriteria were (1) objective evidence of arthritis of theappendicular joints, and (2) two of the following:mucocutaneous lesions, conjunctivitis, and urethritis.These features had to have occurred within sixweeks of one another. It was recognised that thearthritis in patients with RS may be limited to thespine, but because of the difficulty in evaluating sucharthritis, particularly in the early stages, such caseswere not included in the study.

Radiological joint surveys of the spine andappendicular joints were available in 20 cases. Sixothers had had fairly complete radiological evalua-tions, although not all joints were included. Films ofthe lumbosacral spine were available in all cases.Many patients had been followed-up clinically forseveral years, affording opportunities for extendedperiods of radiological observation.

Radiological features

Significant radiological features are summarised inTable 1.

DISTRIBUTIONJoints of the lower extremities were affected in 30cases whereas joints of the upper extremities were

Table 1 Distribution of arthritis and radiologicalfeatures in 36 cases of Reiter's syndromeDistribution No. ofcases

Joints of upper extremities 11Joints of lower extremities 30

Forefoot 18Heel 18Interphalangeal great toe 8Feet more than hands 16

Sacroiliac arthritis 26Symmetric 17Asymmetric 6Unilateral 3

Spondylitis 16Atypical for ankylosing spondylitis 14Typical for ankylosing spondylitis 2

Focal sacroiliitis 4Periosteal bone apposition

(appendicular joints) 26

affected in only 11. The most common site ofinvolvement was the foot, particularly the metatarso-phalangeal joints and heels. The posterosuperior andposteroinferior aspects of the calcaneus wereaffected (Figs 1, 2), particularly the latter, at theattachment of the plantar aponeurosis. The inter-phalangeal joint of the great toe was affected in eightinstances and this appeared to be relatively selectivein three (Fig. 3). Occasionally there was severedestruction of some metatarsophalangeal joints butadjacent ones seemed completely spared. The hipswere affected in one case bilaterally. Arthritis wasmore extensive in the feet than the hands in 16 cases.The terminal interphalangeal joints of the hands wereaffected in two patients and only one such joint wasaffected in both. The sacroiliac joints were affected in26 patients and the spinal column in 16. Focalsacroiliitis near a sarcoiliac joint was noted in fourcases.

REGIONAL OSTEOPOROSISThis was a striking finding in the early stages of thedisease in three patients. It was limited to the foot intwo cases (Fig. 4) and to the hand in one. A frequentfeature was relative absence of osteoporosis despiteextensive joint destruction. This was particularlyevident in the foot.

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L Features andprognosis Suppl. p. 13

Soft-tissue swelling, presumably non-specific dueto joint effusion and synovitis, was common in theankle, knee, and joints of the hand, wrist, and foot.

DESTRUCTION OF ARTICULAR CARTILAGEThis was common and manifested by uniform

narrowing of the interosseous space. Bone destruc-tion occasionally appeared as discrete marginalerosions within the joint at the chondro-osseousjunctions ('bare areas') (Fig. 5) or as loss of corticaldefinition within and adjacent to the joints. Sites ofbone erosion were often blurred by coexistent

Fig. 1 Progressive clacaneal erosion. Early erosion in May 1971 (arrow) was more extensive in September 1971 wit,Ablurred margins presumably due to associated minimal reactive bone formation.

Fig. 2 Note erosion at posterosuperior aspect of Fig. 3 Relatively selective arthritis of interphalangealcalcaneus (arrow) and extensive periosteal bone joint ofgreat toe with severe joint destruction andapposition at inferior aspects of calcaneus, especially reactive bone formation. Note soft tissue swelling ofposteriorly, and cuboid. Calcaneocuboid joint 4th and 5th toes with erosion ofdistal interphalangealrelatively intact but cuboidmetatarsal joint affected. joint of the 4th.

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Suppl. p. 14 Annals of the Rheumatic Diseases

Fig. 4 Osteoporosis, right foot, associated with minimal generalised soft-tissue swelling.

Fig. 5 Arthritis limited to proximal interphalangealjoint. Note fusiforn soft-tissue swelling, uniform loss ofcartilage, and marginal erosions. Erosions partiallyobscured by periosteal bone apposition.

periosteal bone apposition. Large subchondralcyst-like lesions were not seen. Severe destructivearthritis with extensive bone resorption and sub-luxation ('arthritis mutilans' or Launois's deformity)was observed in three cases. All involved themetatarsophalangeal joints. One or more joints maybe 'skipped'-that is, completely spared (Fig. 6).

K...: ::::.: ::: :- .--

Fig. 6 Severe destructive arthritis and subluxation ofmultiple joints with sparing of 4th metatarsophalangealjoint. Note involvement of interphalangeal joint ofgreat toe and relative lack of osteoporosis.

PERIOSTEAL BONE APPOSITIONThis was seen in the appendicular skeleton in 24cases, was often exuberant and fluffy during theactive stage of inflammation, and was typicallycontiguous to affected joints (Fig. 7). Later in thedisease such bone characteristically appeared linearand compact, giving the cortex a 'thickened'

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L Features and prognosis Suppl. p. 15

appearance (Fig. 8). Focal bone apposition, adjacentto a previously affected joint, was at times the onlyindicator of prior inflammation. This feature wasoften subtle (Fig 9).

SACROILIAC ARTHRITISThis occurred in 26 cases and was symmetrical in 17.In the latter it was indistinguishable from theradiological changes of ankylosing spondylitis(Fig. 10). The appearance depended on the stage ofthe disease, with the early lesion often appearing asan indistinctness ofthe subchondral cortices (Fig. 11).Reactive sclerosis in the adjacent bone varied indegree. Bc!nv ankylosis was common. In six patientssacroiliac arthritis was clearly asymmetric and inthree it was unilateral. In three cases the asymmetryor unilaterality persisted for several years (Fig. 12).In four patients there was a focal sclerosis andhyperostosis, involving both sacrum and contiguous

Fig. 7 Arthritis offirst metatarsophalangeal jointassociated with bone erosion and periosteal boneapposition ofmetacarpal and, to lesser extent,phalanx (arrows). Note minimal uniform narrowing ofinterosseous space of this joint.

~~~~~~~~~~~~~

Fig. 8 Destructive arthritis, right fourth metatarsophalangealjoint, with deformity and widening ofbones due toperiosteal bone apposition in a child. Note involvement offirst tarsometartasaljoint with marginal bone erosions andlackofosteoporosis in right foot.

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Fig. 9 Subtle periosteal bone apposition, right medialmalleolus-a residuum of earlier arthritis of the anklewhich at this time appeared normal. Compare withopposite normal side.

ilium, adjacent to the cranial margin of the joint(Fig. 13). This appeared to be analagous to thehyperostoses in the appendicular skeleton andvertebral bodies.

SPONDYLITISTwo of the 16 cases with spinal involvement showedchanges indistinguishable from those of ankylosingspondylitis. However, the others had a distinctiveappearance characterised by asymmetric bonybridges between contiguous vertebral bodies, usuallyinvolving the lateral aspects (Fig. 14). These oftenresembled massive syndesmophytes, appearing toarise from the vertebral body proper, and often therewere several such bone formations which werenon-continuous. The vertebral body margins wherethese arose occasionally showed deformity andsclerosis, suggesting that the bone formationreflected vertebral periostitis rather than inflamma-tion of the discovertebral joints. Furthermore,the intervertebral discs were often ofnormal height atthe affected levels.Although there was squaring of the vertebral

bodies in some cases the anterior surfaces of thevertebrae tended to be spared, even at those levelswhere lateral bony bridging was present. In somepatients segments of the spine appeared to be'skipped'-for example, in one case the spondylitis inthe cervical segment was fairly advanced whereas thedorsal spine:andfmuch of the lumbar segment

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I. Features and prognosis Suppl. p. 17

lOB lCC

Fig. 10 A. Bilateral sacroiliac arthritis with reactive sclerosis. B. Asymmetric lateral bony bridge between Li and L2,having appearance of large syndesmophyte. C. Anterior vertebral surface relatively normal and height of disc notreduced at this level. No other lumbar spinal lesions present. Although the sacroiliac arthritis in this case wasindistinguishable from that seen in ankylosing spondylitis the lumbar lesion is characteristic ofRS and PSA.

appeared to be spared (Fig. 15). Two cases showedunilateral, vertically-oriented ossification adjacent toa discovertebral joint (Fig. 16). The adjacent vertebralbody was unaffected and the appearance suggestedthat this lesion was related to the lateral spinalligament. In no cases of spondylitis was theresparing of the sacroiliac joints, but 10 patients withsacroiliac arthritis did not exhibit spondylitis.

Differential diagn9sis

RHEUMATOID ARTHRITIS (RA)Although erosions occur at the chondro-osseousjunctions ('bare areas') in RS this distribution ismore conspicuous in RA and the erosions appearmore discrete. The feet may occasionally be affectedbefore the hands in the early stages of RA, but it isunusual to see significantly greater involvement in

Fig. 11 Early right sacroiliac arthritis in RS. The the feet than the hands as the disease progresses;lesion consists ofan indistinctness of the cortices, predilection for the joints of the lower extremities isparticularly on the iliac side. unusual in RA..--- --- --- -1 --- -- -- - ----

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E;ig. 12 A. 1958. B. 1964. Persistent asymmetric sacroiliac arthritis: left side more severely involved than right.

Periosteal bone apposition occurs in juvenile RAadjacent to affected joints, but it is almost alwayslinear rather than fluffy and exuberant. Significantperiosteal bone apposition of any type is unusual inadult RA. Subchondral cyst-like lucencies (pseudo-cysts) are not uncommon in rheumatoid arthritis andtend to be multiple, but they are apparently rare inRS. Asymmetric arthritis does occur in adult RA butit is uncommon and not associated with otherfeatures of RS. Selective involvement of the inter-

phalangeal joint of the great toe is not a feature ofRA.The sacroiliac joints are rarely affected in RA, but

the cartilage space has been reported on occasion tohave become completely obliterated. Sclerosingosteiitis in the sacroiliac joints and bone proliferationat the vertebral body margins, however, are decidedlyunusual. The spondylitis in RA is most evidentradiologically in the cervical region and ischaracterised by bone destruction and subluxation.

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I. Features andprognosis Suppl. p. 19

Fig. 13 Focal sclerosing osteitis above right sacroiliac joint in 40-year-old man with RS. Lesion appears to involvecontiguous sacroiliac margins. Left sacroiliac joint normat, right equivocal. There were no lesions in the lumbar spin3.

_ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~..14A 14BFig. 14 A. 1963. Large, asymmetric bony bridge L3-L4 and bilateral sacroiliac arthritis in man with RS. B. 196g.Sacroiliac joints now fused andprevious bony bridge altered owing to remodelling. Other syndesmophytes now evident atL2-3 and L1-2, but generalised syndesmophyte formation as generally seen in ankylosing spondylitis has not developed.Note fairly well preserved disc heights.

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15A 15BFig. 15 A. 1963. B. 1968. Same case as in Fig. 14, showing advanced involvement of cervical spine. Dorsel spine wasnot affected. This case illustrates the tendency towards skipped segments and non-uniform spondylitis. A similardistribution may be seen in PSA.

---.......-. - _

Fig. 16 Paravertebral ossification which is lateral, adjacent to disc, but separate from vertebrae. Such ossification hasalso been described in PSA.

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I. Features andprognosis Suppl. p. 21

The latter is particularly common in the atlantoaxialjoints. Subluxation of the atlantoaxial joints has beendescribed in RS197 but it is rare. It is doubftulwhether true syndesmophyte formation occurs in RA.

ANKYLOSING SPONDYLITIS (AS)Although the spondylitis in RS is occasionallyidentical to that of AS most RS patients showdistinctive features. These include focal syndes-mophyte formation, often massive and associatedwith little change in the adjacent discovertebraljoints; relative sparing of the anterior surfaces of thevertebral bodies; and a tendancy towards non-

uniform involvement of the spinal column (oftenwith'skipped' segments).

In most cases of RS the sacroiliac arthritis is initself indistinguishable from that seen in AS.Nevertheless, asymmetric or unilateral involvementof the sacroiliac joints should prompt suspicion thatone is not dealing with ankylosing spondylitis. Focalsclerosing osteitis adjacent to the sacroiliac jointproper may be a significant differential point whichhas not been emphasised. There is a predilection forthe rhizomelic joints in AS, whereas in RS the hipsand shoulders are not commonly affected.

Irreversible structural changes, including articularbone erosion, may develop in the hands and feet inAS, but usually this is a late manifestation. As in RS,there may be periosteal bone apposition near

affected joints and marginal erosions at the chondro-osseous junctions, but mutilating destruction of thebones is unusual. Heel lesions may be identical inboth conditions but extensive bone destruction andwidespread periosteal bone apposition of thecalcaneus is unusual in ankylosing spondylitis.Selective involvement of the interphalangeal joint ofthe great toe is not a feature of AS.

PSORIATIC ARTHRITIS (PSA)There is a significant overlap between the radiologicalfeatures of PA and RS. This is particularly true of thespondylitis. As in RS, some patients with PA show a

pattern which is identical to that seen in AS. But inmost cases it is more like that of RS, includingasymmetrical involvement of the sacroiliac joints,large non-continuous syndesmophytes primarilyinvolving the lateral aspects of the vertebral bodieswith relative sparing of the anterior surfaces, and'skipped' segments.

I have never seen focal sacroiliitis adjacent to thesacroiliac joint proper in PSA, but it is not clearwhether this will prove to be a significant differentialpoint. An important differential feature is the tendencyfor the terminal interphalangeal joints ofthe fingers to

be affected in PSA, and often many such joints areinvolved. Although patients with RS occasionallyhave arthritis of a terminal interphalangeal jointmultiple involvement of such joints is rare. Resorp-tion of the terminal tufts of the fingers occasionallyoccurs in PSA but this is not a feature of RS.

Periosteal bone apposition adjacent to affectedjoints is common in PSA and is often fluffy andexuberant, as in RS. Similarly, the calcaneal changesand the tendency to involve the interphalangeal jointof the great toe are common in both diseases. Thefeet may be more severely affected than the hands inPSA, but severe involvement of the feet withrelatively little change in the hands seems to be morecommon in RS. Panarthritis of the hands andwrists is not uncommon in PSA but is distinctly rare

in RS.

Discussion

Patients were included in this study because they hadhad abnormal radiological joint findings earlier.Therefore the features described here probablyreflect a more severe form of the disease. Theobservations are significant, however, in that thayindicate the spectrum of radiological findings thatmay be encountered in RS. Since the patient samplewas small and the radiological joint survey incom-plete in many conclusions about the precise incidenceof specific features are probably not warranted.Although none of the described features are in

themselves pathognomonic ofRS certain ones shouldstrongly suggest this diagnosis, particularly whenpresent in combination. These are listed in Table 2.The significance of focal paravertebral ossification,

seen in two cases, is uncertain, This appears to lie inrelation to the lateral ligament and differs fromsyndesmophytes in that it does not seem to involvethe vertebrae. Bywaters and Dixon49 describedsimilar lesions in four patients with PsA but in threeof their cases the possibility of RS was raised.Asymmetric spondylitis with a tendency to 'skipped'

segments is characteristic though not diagnostic. Asimilar pattern has been observed in PSA.208 221 In a

Table 2 Radiological features characteristic ofReiter's syndrome

(1) Severe involvement of the feet with relative sparing of the hands(2) Predilection for the calcaneus, interphalangeal joint of the

great toe, and metatarsophalangeal joints(3) Periosteal bone apposition near affected joints(4) Sacroiliac arthritis, especially when asymmetric(5) Asymmetric, often large, bridging syndesmophytes involving

mainly the lateral aspects of the vertebral bodies with relativesparing of their anterior surfaces

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recent survey of clinical and radiographicabnormalities in 87 patients with AS it was concludedthat the pattern of spinal involvement differed inmen and women.255

Focal sclerosing sacroiliitis, seen in four casesadjacent to the sacroiliac joint, is of interest.Increased density due to osteophytes may be noted inthis location in osteoarthritis of the sacroiliac joints.However, our patients were relatively young andshowed no other features of osteoarthritis in thesejoints. To my knowledge this has not been noted inPSA, RA, or AS but additional studies are neededbefore diagnostic significance is attached to thisfinding.

Conclusion

The radiological manifestations of RS overlap thoseof other rheumatic diseases, particularly AS andPSA. Nevertheless, certain features are characteristicand, depending on the combination of findings in agiven case, the diagnosis may be suspected onradiographical grounds.

General Discussion

DR. J. T. SCOTT: What do you consider the bestradiological projection for sacroiliac joint evalu-ation ?PROF. MARTEL: I don't advocate oblique views becausethey are often confusing and hide early lesions. Iprefer to have an angled beam with the patientsupine (some radiologists prefer the patient prone).The beam is angled 150-200 towards the head. This iseffect distorts the sacroiliac joints but shows theinferior aspect of the sacroiliac area, which is thetrue joint.DR. G. R. V. HUGHES: We and others have seen typicalpatients with both seropositive erosive RA andB27-positive sacroiliitis. Have you looked at thesmall but definite percentage of rheumatoids who areB27-positive to determine whether B27 confers adifferent pattern on coincidental RA?PROF. C. M. PEARSON: We have seen cases of coincidingspondylitis and seropositive rheumatoid arthritiswith nodules which were B27-positive. Cases reportedso far have been tabulated in the April 1978 issue ofArthritis and Rheumatism. However, the pattern ofRA seems to have been quite classical as well as thatofAS ,either beginning first.DR. F. c. ARNETT: Within nearly 200 patients witheither RS or AS we have three patients withcoinciding seropositive nodular rheumatoid arthritis,

one with Felty's syndrome. This incidence is to beexpected in view of the 1-2% population prevalenceof RA.DR. E. ALBERT: We have observed a family in which,within one generation, four siblings were homo-zygous for B27 with apparently classical RA. In thesecond generation all the children were heterozygousfor B27, and four or five of them had developed AS.Has anyone information about the full genotyping oralso the phenotyping of such patients that seem tohave both AS (or RS) and RA?DR. D. A. BREWERTON: In looking at families ofpatients with AS it is all too common to find previousgenerations that have been wrongly diagnosed asRA. When they are reinvestigated clearly they have aform of polyarthritis related to B27 and spondylitis.PROF. T. BITTER: I know that Professors Vischer andFallet from Geneva have systematically tissue-typeda large series of patients with RA for B27 and got aslightly higher percentage of B27 than expectedin the general population. Would they want tocomment on the clinical features of these B27rheumatoids?PROF. G. H. FALLET: The problem has presented itselfslightly differently. Beyond three of Dr. Mason'spatients in London and one in Oxford, we haveobserved in Geneva six patients who presented withboth apparently seropositive RA and AS. Three ofthem had rheumatoid nodules identified by biopsy.Two patients had children, one child of each had AS.All but one of them had HLA-B27 and x-ray findingscompatible with both diseases. Michael Mason's andour feeling is that unless these patients had acoincidental predisposition for both diseases weshould revise our concept ofRA and AS.PROF. A. E. GOOD: From our small arthritis clinic wereported three patients in 1977 with classical findingsfor both diseases. In summing up the reports aboutpatients with RA, nodules, and AS we found thatneither disease seemed to interfere with the expressionof the other. It seems to us that the association ispurely accidential and not so rare after all.PROF. R. F. WILLKENS: Dr. Martel would you commenton a non-marginal syndesmophyte and the distinctionofAS from RS on the basis of these?DR. MARTEL: I haven't used the terms 'marginal' and'non-marginal' syndesmophyte. The syndesmophytesin RS and in PSA may be identical to those in AS-the so-called 'marginal' ones. However, the largeasymmetric syndesmophytes characteristically seenin RS are indeed so large that they appear to benon-marginal. They seem to develop as a conse-quence of vertebral osteitis and bone formation

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I. Features and prognosis Suppl. p. 23

thereafter, not necessarily related to the disco-vertebral junctions. Whenever they are present theyare useful in differentiating RS from AS. I have notseen such bone formation in classical AS. Thesacroiliac joints are the least help unless the sacroiliacarthritis is asymmetrical. Such asymmetry can beseen early in the course of AS. It is unusual to findsevere involvement on one side as the diseaseprogresses with little or no change on the other.Most of the time patients with RS present withsacroiliac arthritis which is indistinguishable fromthat of AS.PROF. B. AMOR: With the former we found moredestructive lesions. Likewise bone proliferation onthe great toes seems to be more common in psoriaticarthropathy than in RS.DR. MARTEL: The appearance I have shown in the feetis identical to what we may see in PSA, including theheels and terminal interphalangeal joints of the greattoes. In AS I am not sure. We have seen patients withAS with severe arthritis of the hands and feet as alate manifestation-a picture indistinguishable fromthat seen in RS. In the latter, however, structuralchanges in the joints of the feet often occur relativelyearly.DR. A. CALIN: What is the rate of progression of theselesions? We have had the impression that somepatients with RS have developed plantar spurs

rapidly over a period of six to twelve weeks. Haveyou any studies on sequential change?DR. MARTEL: No, I have not.DR. J. C. GERSTER: Achilles tendonitis is found verycommonly in RS. In a study with Professor Falletwe found it in AS, PSA, and especially in RS. We didnot find it in RA.DR. MARTEL: We have seen achilles tendonitis inrheumatoid arthritis. Radiologically it is oftendifferent from the three conditions you mentioned.DR. T. L. VISCHER: I was struck that you have verylittle joint narrowing in your RS patients.DR. MARTEL: I agree that the cartilage often seems tobe less affected than the bone. There is often boneerosion and bone apposition with relatively littlechange in the interosseous space. The cartilage maybe altered and yet the interosseous space is notnarrowed. The space does not reflect the degree ofcartilage destruction because the fluid and soft tissueproliferation may take its place within the joint.DR. CALIN: We have not emphasised the entheso-pathic nature of the disease. Clinically we recognisesausage digits, insertional tendinitis, and otherextrasynovial processes. These correlate withradiological evidence of periostitis, peri-insertionalosteoporosis, and other changes that differentiatethis enthesopathic disorder from the primarysynovitides, typified by RA.

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Radiological manifestations of Reiter's syndromeard.bmj.com/content/annrheumdis/38/Suppl_1/12.full.pdf · spectrum of radiological manifestations. Although ... appendicular joints,