BRITISH JOURNAL OF ORAL & MAXILLOFACIAL SURGERY

British Journal of Oral and Maxillofacial Surgery (2000) 38, 205–208© 2000 The British Association of Oral and Maxillofacial Surgeonsdoi:10.1054/bjom.1999.0181

Synovial chondromatosis of the temporomandibular joint

H. Miyamoto, * H. Sakashita, † D. F. Wilson, ‡ A. N. Goss §

*Former Visiting Research Fellow, Oral & Maxillofacial Surgery Unit; Currently Department of OMFS &Dentistry, †Head, Department of OMFS & Dentistry, Fujieda Municipal General Hospital, Fujieda,Shizuoka, Japan; ‡Associate Professor, Oral Pathology; §Professor & Director, Oral & MaxillofacialSurgery Unit, The University of Adelaide, Adelaide, Australia

SUMMARY. We report two cases of temporomandibular joint (TMJ) synovial chondromatosis, one of which wasin the early stage and treated arthroscopically. The second was more advanced and recurred after removal of the freebodies, and so required condylectomy and synovectomy.

INTRODUCTION

Synovial chondromatosis commonly affects the knee,elbow, wrist, shoulder and hip; involvement of thetemporomandibular joint (TMJ) is rare.2,3

The main symptoms are pain, swelling, and click-ing with deviation and limitation of mandibularmovement.4 Because TMJ synovial chondromatosis isso rare, it is often mistaken for an internal derange-ment which has similar symptoms.3

Computed tomography (CT) and magnetic reso-nance imaging (MRI) can show loose bodies in thejoint space, and are excellent investigations if synovialchondromatosis is suspected.5,6 Double contrastarthrotomography will help to diagnose noduleswithin the joint space,7 and direct inspection of thejoint space by arthroscopy will confirm the diagnosis.8

The histological metaplastic changes of synovialchondromatosis can be separated into three phases ofdevelopment:9 phase 1 (early) – intrasynovial involve-ment with metaplasia only in the synovial membrane

20

Fig. 1 – Preoperative MRI (T1) of the right TMJ (case 1) showingtwo masses of low signal intensity (big arrows) anterior to thebony changes in the condyle (small arrow).

and no loose bodies; phase 2 (transitional) – intrasyn-ovial involvement and free bodies with metaplasia inthe synovial membrane, and detached particles; andphase 3 (advanced) – multiple free bodies varying insize from 1–10 mm or more together with detachedparticles and no sign of intrasynovial disease.

In the earliest phase, there is proliferation of undif-ferentiated stem cells in the stratum synoviale.9 Later,cells that resemble fibroblasts form a primitive chon-droid matrix from which the resulting nodules of car-tilage grow, either by proliferation of the interstitialcell that produced the chondroid matrix or by surfacegrowth of new cells that differentiate near the surfaceto produce the matrix.9

In this paper, we report the diagnosis and manage-ment of two cases of TMJ synovial chondromatosis,one early and one transitional.

CASE REPORTS

CASE 1

A 21-year-old woman presented to the Dentistry and OralSurgery Clinic at the Ishikawa Prefectural Central Hospitalcomplaining of pain in the right TMJ for the past 15months. On physical examination, her maximal mouthopening was 34 mm, which caused pain that was constant at80 on visual analogue scale (VAS, 0–100) in the right TMJ.When she opened her mouth her mandible deviated to theright with crepitus. She also had a history of squamous cellbreast cancer (T3N2MO) which had been diagnosed severalmonths before she presented to us. She had responded wellto the operation but had a poor prognosis.

Panoramic and transcranial radiographs and coronaltomograms showed bony changes on the condyle of theright side but no calcifying lesions in the right TMJ. MRI(T1 weighted images) showed two masses of low signalintensity anteriorly in the right TMJ with bony changes inthe condyle (Fig. 1).

These findings suggested a clinical diagnosis of TMJosteoarthrosis and anterior disc displacement without reduc-tion of the TMJ. There was no sign of metastatic disease inher mandible. Conservative treatment (physiotherapy and

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Fig. 2 – Operative arthroscopic view of the anterior upper space of the TMJ (case 1) showing metaplasia (arrows) only in the synovialmembrane (A and B).

A B

BA

Fig. 3 – Histological appearance of the synovial metaplasia (case 1). (A) Low-power photomicrograph showing hyperplastic, foldedsynovial lining (L). The hypercellar synovial tissues merge with less cellular fibrous tissue and pseudo cartilage (C). (S=joint space;haematoxylin and eosin; original magnification ×40); (B) High-power photomicrograph showing hyaline cartilage-like tissue. (haematoxylinand eosin; original magnification ×400).

anti-inflammatory drugs) had been tried for three monthspreviously, but she had not responded.

We did a double puncture arthroscopic examination ofthe right TMJ under general anaesthesia, which showedmetaplasia in the synovial membrane of the upper jointspace (Fig. 2) and a section of the synovium around themetaplasia looked fibrillated.

There were pseudowall capsular adhesions with synovitisin the anterior compartment, but no loose bodies. Underarthroscopic guidance, the metaplasia and grossly abnormalsynovium were removed and the capsular adhesionsresected.

The patient was immediately able to open her mouth to 50mm with slight deviation to the right side and her pain wasrecorded as 0 (VAS). The postoperative MRI showed that themass of low signal intensity had been removed (Fig. 3).On histological examination, the specimens showed focal,chronic proliferative synovitis with early metaplasia of the

cartilage (Fig. 4). These findings confirmed the diagnosis ofearly synovial chondromatosis of the TMJ.The patient has been followed up regularly for the past 15months and has been symptom-free with no recurrence.

CASE 2

A 37-year-old woman presented to a private specialist inAdelaide with a 10-year history of intermittent clicking,locking, and painful right TMJ that had severely limited herjaw movements for the last six months. She had initiallybeen successfully treated with a bite splint by a prosthodon-tist eight years previously. No radiographs had been taken atthat time.

On physical examination, she had a maximum mouthopening of 15 mm with pain and crepitations in the rightTMJ. She was otherwise fit and well, and there was no

Synovial chondromatosis of the TMJ 207

Fig. 4 – Postoperative MRI (T1) of the right TMJ (case 1) showingthat the mass has been removed.

Fig. 5 – Preoperative CT (case 2) showing calcifications in the rightTMJ (arrows).

Fig. 6 – Histological appearance of the synovial metaplasia (case2). (A) Low-power photomicrograph showing two partiallycalcified hyaline cartilage bodies (C). These cartilage bodies lieadjacent to or are confluent with dense fibrous connective tissue(F) (haematoxylin and eosin; original magnification × 400); (B)High-power photomicrograph of a cartilage body exhibitingpatchy calcification (arrows). The calcifying cartilage is partiallycircumscribed by a layer of non-vital focally calcified cartilage(NV). (haematoxylin and eosin); (original magnification × 200).

A

B

history of injury to the jaw. A CT showed some calcifyingmasses in the right TMJ (Fig. 5), consistent with synovialchondromatosis.

At arthrotomy under general anaesthesia, there weremultiple calcifications in the upper joint space of the rightTMJ, and 20 milky-white loose bodies were removed.Because the joint space and the synovium were clear andlooked normal to the naked eye, they were preserved. As hermouth opening was only 25 mm at the time, we did a bilat-eral coronoidectomy to produce a final mouth opening of35 mm.

Subsequently, her mouth opening reduced to 23 mm byfour months and to 18 mm by six months. A CT was takeneight months postoperatively which showed recurrence ofthe synovial chondromatosis and fibrous ankylosis of theright TMJ, so we did a condylectomy and synovectomy

under general anaesthesia nine months after the initial oper-ation, which increased her mouth opening to 45 mm.

On histological examination, the loose bodies that hadbeen removed at the first operation were composed of mul-tiple nodules of hyaline cartilage covered by fibrous connec-tive tissue. The tissue that was removed at the secondoperation showed cartilaginous metaplasia (Fig. 6). Thesefindings confirmed second phase transitional synovial chon-dromatosis of the TMJ.

The patient could open her mouth to 40 mm fourmonths postoperatively and has been followed up for 10months with no recurrence.

DISCUSSION

Of our two cases of synovial chondromatosis of theTMJ, one was phase 1 of the disease and the second inphase 2 (transitional). In case 1 there was pronouncedmetaplasia in the synovial membrane on the MRI ofthe displaced and grossly altered disc. Arthroscopicexamination confirmed the diagnosis. In case 2 CTconfirmed the diagnosis in that there were loose bod-ies in the TMJ.

Various treatments have been used for synovialchondromatosis of the TMJ.2,8 When arthrography

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confirms its location in the upper space, it can beremoved by arthroscopic surgery,7 otherwise opensurgery or arthrotomy for removal of the loose bodieswith the addition of partial or complete synovectomyis required.8,10,11 In the first or second phase, removalof the mass together with all loose bodies and theaffected synovium is usually sufficient8 because therecurrence rate is low and it may even regress sponta-neously.13 If direct examination at the time of surgeryshows only loose bodies with inactive synovial disease(the third phase) synovectomy is not necessary.9

Case 1 was treated arthroscopically because thecondition was early and confined to the superior jointspace, and the patient’s general prognosis was poor.The lesion was removed arthroscopically and this wasconfirmed by postoperative MRI.

In case 2 the synovial chondromatosis recurredeight months after the first operation. The first opera-tion was aimed at removing the loose bodies and spar-ing the joint structure as it was thought that the diseasewas advanced. The synovium looked normal to thenaked eye, but histologically the synovial membranewas metaplastic. This patient’s maximum incisal open-ing decreased from 23 mm at four months to 18 mm atsix months postoperatively. The development offibrous ankylosis on the lateral pole of the joint is con-sistent with some surgical articular damage as well asrecurrence of the synovial chondromatosis. In patientswith synovial chondromatosis whose mouth-openingdecreases postoperatively recurrence should be consid-ered. Further surgery should be aggressive and includesynovectomy for the chondromatosis. Condylectomymay be required to overcome the ankylosis.

References

1. Fee WE Jr, Windorst P, Wiggins R, Pang L. Synovialchondromatosis of the temporomandibular joint. OtolaryngolHead Neck Surg 1979; 87: 741–748.

2. Wise DP, Ruskin JD. Arthroscopic diagnosis and treatment oftemporomandibular joint synovial chondromatosis: report ofa case. J Oral Maxillofac Surg 1994; 52: 90–93.

3. Mendonca-Caridad JJ, Schwartz HC. Synovialchondromatosis of the temporomandibular joint: arthroscopicdiagnosis and treatment of a case. J Oral Maxillofac Surg1994; 52: 624–625.

4. Forssell K, Happonen R-P, Forsell H. Synovialchondromatosis of the temporomandibular joint: report of acase and review of the literature. Int J Oral Maxillofac Surg1988; 17: 237–241.

5. Ingen JM van, Man K de, Bakri I. CT diagnosis of synovialchondromatosis of the temporomandibular joint. Br J OralMaxillofac Surg 1990; 28: 164–167.

6. Igarashi C, Kobayashi K, Imanaka M et al. Image findings ofsynovial chondromatosis of temporomandibular joint: reportof eight cases and review of literature. J Jpn Stomatol Soc1996; 45: 462–469.

7. Miyamoto H, Sakashita H, Miyata M, Kurita K. Arthroscopicdiagnosis and treatment of temporomandibular joint synovialchondromatosis: report of a case. J Oral Maxillofac Surg1996; 54: 629–631.

8. Carls FR, Hochstetter A von, Engelker W, Sailer HF. Loosebodies in the temporomandibular joint: the advantages of arthroscopy. J Craniomaxillofac Surg 1995; 23:215–221.

9. Milgam JW. Synovial chondromatosis: a histopathologic study of thirty cases. J Bone Joint Surg 1977; 59A:792–801.

10. Miller AS, Hardwock RD, Daley DJ. Temporomandibularjoint synovial chondromatosis: report of a case. J Oral Surg1978; 36: 467–468.

11. Coolican MR, Dandy DJ. Arthroscopic management ofsynovial chondromatosis of the knee: findings and results in18 cases. J Bone Joint Surg 1989; 71B: 498–500.

12. Swan EF, Owens WF. Synovial chondromatosis: a case reportwith spontaneous regression and review of the literature.South Med J 1972; 65: 1496–1500.

The Authors

H. MiyamotoFormer Visiting Research Fellow Oral & Maxillofacial SurgeryUnit; Currently Department of OMFS & DentistryH. SakashitaHead, Department of OMFS & Dentistry, Fujeida MunicipalGeneral Hospital, JapanD. F. WilsonAssociate Professor Oral PathologyUniversity of Adelaide, Adelaide, AustraliaA. N. GossProfessor & Director Oral & Maxillofacial Surgery UnitUniversity of Adelaide, Adelaide, Australia

Correspondence and requests for offprints to: Professor A.N.Goss, Oral & Maxillofacial Surgery Unit, University of Adelaide,South Australia, 5005

Paper received 26 October 1998Accepted 1 February 1999