Synovial Chondromatosis of the Temporomandibular Joint

Abstract

Synovial chondromatosis is a rare condition characterized by the presence of loose cartilaginous bodies, due to the abnormal proliferation of synovial membrane. However, its manifestation in the temporomandibular joint is a rare finding, occurring predominantly in females. This case report describes the clinical features, diagnosis and management of a case of synovial chondromatosis.

Introduction

Synovial chondromatosis (SC) is a rare condition characterized by the presence of loose cartilaginous bodies, due to the abnormal proliferation of synovial membrane. Synovial chondromatosis is defined by the World Health Organization as a benign nodular cartilaginous proliferation arising from the joint synovium, bursae or tendon sheaths [1]. It mainly affects large joints such as knee, hip, shoulder and elbow, commonly in males. However, its manifestation in the temporomandibular joint (TMJ) is a rare finding, occurring predominantly in females [2]. SC was originally described by Ambroise Pare in 1558, and the involvement of the TMJ was described in 1933 by Auhausen [3]. Two forms of the SC have been recognized: primary and secondary. It may develop as a primary lesion or may arise after a trauma or another disease process such as osteoarthritis. The pathogenesis of the primary form of SC is unknown. It has been proposed that the disease develops as a response to repetitive, low-grade trauma. Inflammation, parafunctional habits or joint overuse, as well as degeneration, has been seen as potential causative factors for the secondary form. SC is observed in 17% of patients treated arthroscopically due to TMJ osteoarthritis [4].

Panoramic radiographs, CBCT and CT facilitate the clinical diagnosis of SC; however, histopathological analysis is mandatory to confirm the disease. We report a case of a SC treated successfully through a surgical approach.

Case Report

A 38-year-old male patient visited the Department of Oral and Maxillofacial Surgery, Vydehi Institute of Dental Sciences and Hospital, in February 2015 with a chief complaint of pain and swelling in the right preauricular region since 8 years. He gave a history of right ear pain and preauricular tenderness while opening and closing his mouth. Physical examination revealed tenderness and swelling in the TMJ region, with a mouth opening of 38 mm. There was slight deviation to the right and a clicking sound in the right joint during mouth opening. There was no history of trauma or any parafunctional habit.

A panoramic radiograph showed multiple calcified loose bodies around the right mandibular condyle. There was an increase in the joint space with mild erosive changes in the condylar head. CBCT showed the presence of faint opacities in the medial, anterior, posterior and superior aspect of condyle which probably represented extra-articular calcifications. Axial and coronal CT images (Figs. 1, 2) show distinct nodules within an expanded upper joint compartment and also revealed widening of the TMJ space and multiple calcifications around it. The images also showed bony erosion with sclerotic changes in the adjacent articular eminence and glenoid fossa. Based on clinical and imaging findings, a presumptive diagnosis of SC of the left TMJ was made.

Fig. 1.

Coronal CT

Fig. 2.

Axial CT

Surgical exploration of the mass via an Alkayat Bramley incision was performed under general anaesthesia. Layered dissection was done to expose the tumour mass situated lateral to the right condylar region which was composed of multiple pebble-like cartilaginous structures (Fig. 3). This lateral part of the tumour was removed. Subsequently, osteotomy of the neck of the condyle was performed. Then the condyle was swung to gain approach to the medial aspect of the condyle, and calcified bodies (Fig. 4) were removed. The articular disc was repositioned and sutured, and condylar shave and glenoid fossa shave were done in the region of the erosion. The condylar neck was fixed with two titanium miniplates and screws (Fig. 5).

Fig. 3.

Exposed pathology

Fig. 4.

Fixation of osteotomized condyle

Fig. 5.

Specimen of the pathology

The diagnosis was confirmed with histopathological investigation. The gross pathologic appearance showed hyperplastic synovium covering white multilobulated nodular projections of hyaline cartilage. Histopathology of the same revealed globular masses of cartilage tissue which exhibited areas of calcification. Chondrocytes showing mild atypia in the lacunae were seen. The synovial connective tissue between the cartilages was delicate and fibrillar. The peripheries of the globular masses were cellular with numerous blood vessels.

Based on the clinical, radiological and histopathological findings, the diagnosis of SC of right TMJ was made. The patient showed good functional recovery after surgery, and no evidence of recurrence or residual disease was detected in the operated joint after 3 years (Fig. 6).

Fig. 6.

OPT after 3 years

Discussion

Synovial chondromatosis (SC) is a non-neoplastic and infrequent joint disease characterized as a proliferative disorder of the synovium associated with the formation of metaplastic cartilaginous nodules originating from the synovial membrane [5]. It is also known as synovial osteochondromatosis and synovial chondrometaplasia and commonly manifests with joint swelling, pain and joint dysfunction [6].

Because of the absence of physical signs and symptoms, SC of the TMJ often receives a delayed diagnosis or is misdiagnosed for other common diseases with similar symptoms such as TMJ disorders or arthritis. The mean latency period is relatively long, and the average time of onset of SC of the TMJ is more than 1 year. While the clinical features are not usually conclusive, diagnosis of SC of the TMJ is usually made using conventional radiography, computed tomography (CT) and magnetic resonance imaging (MRI) which reveal loose bodies in the joint space. Although conventional radiographs as the first-line technique for diagnosis of TMJ disorders can show widening of the joint spaces, those in which the cartilaginous nodules lack calcification or ossification may not be detected. CT and MRI are used to evaluate TMJ diseases and can make a more accurate diagnosis [7].

The histological staging of synovial chondromatosis was published by Milgram in 1977 and is based on disease activity and development. Stage 1 is the early stage and represents intrasynovial metaplasia without loose bodies; peri-focal macrophages may be present. Stage 2 is the transitional stage, in which synovial involvement and detached bodies are present. Stage 3 shows no more active intrasynovial disease (metaplasia), but the joint space is full of multiple detached bodies, and secondary calcification or ossification may be present. The secondary calcification is called Henderson–Jones syndrome. The loose bodies in the joint space may be surrounded by a layer of synovial membrane. Over 80% of patients are at Milgram stage 3 when the diagnosis of synovial chondromatosis is made [8].

There have been rare reports of bilateral involvement [9, 10] and involvement of both compartments [11].

A classic open surgical approach to the TMJ is the treatment of choice because of the impossibility of removing all of the loose bodies by other means. Synovectomy is the most frequent procedure because of the association with loose bodies. The synovial membrane and loose bodies are all removed from the joint space, often accompanied by articular disc resection and less frequently by condylar resection [6].

A combination of open surgery and arthroscopy for the treatment of synovial chondromatosis (SC) of the temporomandibular joint (TMJ) has also been mentioned. This technique has the benefits of the complete elimination of diseased tissues with a minimal osteotomy and a short surgical duration [12].

The recurrence rate of SC appears to be very low. The probable reasons were bony erosions on the condyle or fossa, which were ignored during the initial operation when the lesion inside the marrow was not removed thoroughly. The cause of the recurrence is probably the active metaplastic foci in the tiny bony erosion that was recorded as being in an early stage of Milgram classification. These foci probably continued to grow, proliferate and invade the bone, finally inducing recurrence [13]. The significant literature pertaining to the condition is enumerated in Table 1.

Table 1.

Literature review of significant articles related to synovial chondromatosis

No.	Authors	Journal	Incidence
1	Holmlund AB, Eriksson L, Reinholt FP	Int J Oral Maxillofac Surg 32:143, 2003	Clinical, surgical and radiological aspects
2	Leon Ardekian et al.	J Oral Maxillofac Surg 63:941–947, 2005	Report and analysis of 11 cases
3	Jong-Ki Huh	Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006;101:e83–e88	Condylar extension
4	Lieger O, Zix J, Stauffer-Brauch EJ, Iizuka T	J Oral Maxillofac Surg 2007;65:2073–80	Case report and literature review
5	Li-wei Peng, De-min Yan, Yong-gong Wang and Ya-dong Li	J Oral Maxillofac Surg 67:893–895, 2009	Bilateral involvement
6	J. Sato, K.-I. Notani, J. Goto, M. Shindoh, Y. Kitagawa	Int. J. Oral Maxillofac. Surg. 2010; 39:86–88	Involvement of both joint spaces
7	Meng J, Guo C, Yi B, et al.	Oral Surg Oral Med Oral Pathol Oral Radiol Endod 109:441, 2010	Clinical and radiological findings
8	Raquel Guijarro-Martínez et al.	Journal of Cranio-Maxillo-Facial Surgery 39 (2011) 261–265	Bilateral involvement
9	Yui Mori et al.	Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011;112:e35–e39	17-year follow-up
10	Masahiro Wake et al.	British Journal of Oral and Maxillofacial Surgery 51 (2013) 164–169	Inflammatory mediators in synovial fluid
11	Aecio Abner Campos Pinto Jr et al.	Head and Neck Pathol (2015) 9:525–529	Surgical treatment
12	Xingguang Liu, Zhongyang Huang, Wangyong Zhu, Peisheng Liang and Qian Tao	J Oral Maxillofac Surg 74:2159–2168, 2016	Analysis of 10 cases and literature review
13	Z.-X. Han, M.-J. Chen, C. Yang, M.-J. Dong	BJOMS 55 2017. 965–967	274 cases in 16 years
14	J.N. Khanna R. Ramaswami	Int. J. Oral Maxillofac. Surg. 2017; 46:1579–1583	Cranial extension
15	G. Bai, C. Yang, Y. Qiu, M. Chen	Int. J. Oral Maxillofac. Surg. 2017; 46:208–213	Open surgery assisted with arthroscopy

Compliance with Ethical Standards

Conflict of interest

None.