ANESTHESIA/FACIAL PAIN
Synovial Plicae and Temporomandibular Joint Disorders: Surgical Findings KenIchiro Murakami, DDS, DMSc,* Shinsuke Hori, DDS,y Yoshinori Yamaguchi, DDS, PhD,z Louis G. Mercuri, DDS, MS,x Naota Harayama, DDS,k Syouta Maruo, DDS,{ and Tsuneo Takahashi, DDS, PhD# Purpose:
Synovial plicae and their relation to pain and disability have been reported in the orthopedic literature in association with the knee and other extremity joints. However, the occurrence of synovial plicae in the temporomandibular joint (TMJ) have rarely been reported. This report describes the surgical appearance, distribution, and histologic findings of synovial plicae in patients with TMJ recurrent dislocation and internal derangement.
Materials and Methods:
Twenty consecutive patients, 16 with recurrent dislocation and 4 with internal derangement, who underwent open TMJ surgery by the same surgeon from 2010 to 2013 were studied retrospectively.
Results:
Synovial plicae were detected in 18 of 28 joints (64.3%). Synovial plicae were observed in 15 of 24 joints (62.5%) with recurrent dislocation and in 3 of 4 joints (75%) with internal derangement. Histologic findings of these plicae were consistent with dense fibrous or cartilaginous tissues, with some exhibiting a synovial lining.
Conclusions: Although the role of synovial plicae in TMJ disorders is unknown and unstudied, consideration should be given to investigating the possible relation of these structures to the signs and symptoms of TMJ disorders. Ó 2015 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 73:827-833, 2015
In the orthopedic literature, symptomatic synovial plicae have been reported in the knee1-3 and other extremity joints, such as the shoulder4 and elbow.5 Although the common signs and symptoms of impingement in the medial plica of the knee include crepitation, popping, snapping, instability, catching, and pain,1-3 there is major crossover of symptoms and clinical findings associated with more commonly seen diagnoses.3 Thus, the specific diagnosis of plica syndrome is controversial.1-3 The anatomic occurrence and distribution of
plicae in orthopedic joints has been visualized on magnetic resonance imaging (MRI)2,3,5-7; however, MRI has not been able to distinguish between pathologic and nonpathologic plicae.6,7 MRI findings can be useful to evaluate the thickness and extension of plica and synovitis with concomitant effusion.2,5-7 The gold standard for a diagnosis of plicae in orthopedics is arthroscopy followed by excision.1-7 To date, in the literature on the temporomandibular joint (TMJ), only cadaveric studies showing the {Staff Surgeon, Department of Oral and Maxillofacial Surgery,
*Consultant Surgeon, Department of Oral and Maxillofacial Surgery, Ako City Hospital, Visiting Professor, Department of
Kyotango City Kumihama Hospital, Kyotango, Japan.
Maxillofacial Surgery, Kanagawa Dental University, Graduate
#Professor and Head, Department of 3D Imaging Anatomy,
School of Dentistry, Yokosuka, Japan.
Kanagawa Dental University, Ako, Japan.
yChief, Department of Oral and Maxillofacial Surgery, Kyotango
Address correspondence and reprint requests to Dr Murakami:
City Kumihama Hospital, Kyotango, Japan.
Department of Oral and Maxillofacial Surgery, Ako City Hospital,
zChief, Department of Oral and Maxillofacial Surgery, Kusatsu
Nakahiro 1090, Ako city, Hyogo, Japan 678-0232; e-mail: murakeny@
General Hospital, Kusatsu, Japan. xVisiting Professor, Department of Orthopedic Surgery, Rush
yahoo.co.jp Received August 6 2014
University Medical Center, Chicago, IL; Clinical Consultant, TMJ
Accepted December 17 2014
Concepts, Ventura, CA.
Ó 2015 American Association of Oral and Maxillofacial Surgeons
kStaff Surgeon, Department of Oral and Maxillofacial Surgery,
0278-2391/14/01837-0
Kyoto City Hospital Kyoto, Japan. Formerly in the Department of
http://dx.doi.org/10.1016/j.joms.2014.12.018
Oral and Maxillofacial Surgery, Ako City Hospital, Ako, Japan.
827
828 presence, appearance, and histology of synovial plicae can be found.8-10 However, there is little description related to the clinical appearance of synovial plicae in patients with TMJ disorders.11,12 The purpose of this report is to describe the occurrence, distribution, and histologic findings of synovial plicae in patients who underwent open TMJ surgery for recurrent dislocation and internal derangement.
Materials and Methods Twenty consecutive patients, 16 patients with recurrent dislocation and 4 with internal derangement, who underwent open TMJ surgery from 2010 to 2013 were studied retrospectively. The diagnoses and surgical indications for patients with dislocations and internal derangement were based on criteria published by the American Association of Oral and Maxillofacial Surgeons.13 Any patients with a diagnosis of TMJ pathology, such as neoplasm, hyperplasia, rheumatoid arthritis, loose body disease, or ankyloses, were not included. Surgery for recurrent dislocation involved eminectomy; however, 1 patient underwent open repositioning. Discectomy without a disc substitute was used in all internal derangement cases, but 1 patient underwent a discectomy with high condylectomy. All surgeries were performed by the same surgeon (K.M.). The inclusion criteria for patients with internal derangement were nonreducible disc displacement (Wilkes stages III, IV, and V) confirmed by MRI and no response to nonsurgical treatment for at least 6 months. The exclusion criteria were patients whose condition could be managed by arthroscopy or arthrocentesis alone. In all cases, preoperative diagnostic imaging included orthopantomography and 1.5-T MRI with T1-and T2-weighted imaging in the sagittal plane in the closed and open jaw positions with or without coronal sections. For patients with recurrent dislocation, the inclusion criteria were a history of repetitive dislocations for longer than 3 months and no response to nonsurgical treatment, such as a protective bandage, occlusal splint, and observation. Preoperative diagnostic imaging included orthopantomography or computed tomography. MRI was used only when the patient had a history of clicking or limited jaw opening. Fourteen specimens of synovial plica were examined histologically by the department of surgical pathology at each hospital. Only 4 synovial plicae were documented in the surgical record owing to an earlier observation of fine or small plicae. Because of the retrospective nature of this study, it was granted an exemption in writing by the institutional review boards of Ako City Hospital (Ako Japan), the Kyotango Kumihama City Hospital (Kyotango, Japan), and Kusatsu General Hospital (Kusatsu, Japan).
SYNOVIAL PLICAE AND TEMPOROMANDIBULAR JOINT
Results Seven male and 13 female patients 25 to 85 years old (mean, 59.45 yr) were included in the study. Twentyeight 28 joints (12 unilateral and 8 bilateral) underwent open surgery. Patients 6, 12, and 13 had a diagnosis of bilateral recurrent dislocation by history; however, at surgery, these dislocations were found to be unilateral (Table 1). The average age of the 16 patients with TMJ dislocation was 63.2 years. This group consisted of 24 joints (8 unilateral and 8 bilateral). Signs and symptoms included condylar hypermobility with recurrent dislocations and 1 bilateral persistent dislocation. These patients reported pain only when their mandibles were dislocated. Eminectomy was performed in 15 patients, and 1 patient underwent bilateral discectomy and joint repositioning owing to persistent joint dislocation with the damaged disc. Four patients (mean, 44.3 yr of age) had internal derangement (3 with Wilkes stage IV and 1 with Wilkes stage V). All underwent discectomy, but 1 patient also underwent high condylectomy because of a ruptured disc and a deformed condyle. All these patients had signs and symptoms of internal derangement, limited mandibular opening with deviation to the affected side, and limited mandibular lateral and protrusive excursions. However, none had any atypical pain complaints that might be associated with entrapment of synovial plicae. Synovial plicae were seen in 14 patients (18 of 28 total operated joints [64.3%]; Table 2). Fifteen synovial plicae were seen in 11 patients (mean, 68.1 yr old; 15 of 24 joints [62.5%]) with recurrent dislocation. Plicae were not detected in 5 patients (mean, 52.6 yr old). In 3 (mean, 42.6 yr old) of the 4 patients with closed-lock internal derangements (2 with Wilkes stage IV and 1 with stage V), synovial plicae were detected in 3 of 4 joints (75%). At preoperative diagnostic imaging, there were no obvious specific findings relating to the presence of synovial plicae. At surgery, the synovial plicae found were typically broad (Figs 1-3), meniscus-like (Fig 4), or tongue-like (Fig 5) in shape. Seven were tongue-like, 4 had a broad form, 1 had a meniscus-like and fringe-like shape, and the other 5 were amorphous in shape (Table 2). The plicae were broader in the dislocation than in the internal derangement group. Four broad plicae were found in 2 cases (patients 11 and 15); 1 meniscus-like plica (patient 5) and 1 fringe-like plica (patient 7) were detected only in the dislocation group. These plicae presented as relatively thick, wide, pliable areolar tissue lying within the lateral para-discal recess (groove) and intruding into the upper joint space (Fig 6A-C). No obvious differences in the form and shape of fine
829
MURAKAMI ET AL
Table 1. OPEN SURGICAL CASES OF THE TEMPOROMANDIBULAR JOINT
Case 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Age (yr)
Gender
Diagnosis
Procedure
Side
Wilkes Stage
25 31 70 62 46 85 67 84 85 75 70 53 63 65 73 58 40 40 49 48
M F M F M F F F F F M F F M M F F M F F
Re, D Re, D B, Re, D Re, D B, Re, D B, Re, D Re, D B, Re, D B, D Re, D B, Re, D B, Re, D B, Re, D B, Re, D B, Re, D B, Re, D ID ID ID ID
eminec eminec eminec eminec eminec eminec eminec eminec reposition eminec eminec eminec eminec eminec eminec eminec discectomy discectomy discectomy discectomy + high condylectomy
L R B L B R L B B L B L R B B B L R R L
IV IV IV V
Abbreviations: B, bilateral; D, dislocation; eminec, eminectomy; F, female; ID, internal derangement; L, left; M, male; R, right; Re, recurrent. Murakami et al. Synovial Plicae and Temporomandibular Joint. J Oral Maxillofac Surg 2015.
tongue-like or other amorphous plicae were found (Fig 6D). Regarding the histopathologic finding of the plicae, the most consistent finding (12 of 14 specimens) was
dense fibrous tissues (Fig 7A) with scattered cartilaginous cells (Fig 7B, Table 2). These findings were frequently observed in association with hyalinization. Distinct cartilaginous tissue was found in 2 specimens
Table 2. CASES OF DETECTED SYNOVIAL PLICAE
Case
Age (yr)
Gender
Surgical Procedure
Side and Form
Histology
4 5 6 7 9
62 46 85 67 85
F M F F F
eminec eminec eminec eminec reposition
10 11
75 70
F M
eminec eminec
13 14 15
63 65 73
F M M
eminec eminec eminec
16
58
F
eminec
17 18 20
40 40 48
F M F
discectomy discectomy discectomy + high condylectomy
L, small tongue-like L, meniscus-like tongue-like L, small fringe R, small tongue-like L, small tongue-like L, tongue-like R, broad L, broad R, miscellaneous L, miscellaneous R, broad L, broad R, miscellaneous L, miscellaneous L, small tongue-like R, tongue-like L, miscellaneous
non fibrous cartilaginous + synovium cartilaginous non non synovium + fibrous R, fibrous L, fibrous + calcification fibrous L, fibrous R, fibrous L, fibrous R, fibrous L, fibrous non R, synovium + fibrous L, fibrous
Abbreviations: eminec, eminectomy; F, female; L, left; M, male; non, no histologic examination; R, right. Murakami et al. Synovial Plicae and Temporomandibular Joint. J Oral Maxillofac Surg 2015.
830
FIGURE 1. Broad synovial plica in the right temporomandibular joint (patient 15). Murakami et al. Synovial Plicae and Temporomandibular Joint. J Oral Maxillofac Surg 2015.
SYNOVIAL PLICAE AND TEMPOROMANDIBULAR JOINT
FIGURE 3. Synovial plicae removed from the right and left sides of the temporomandibular joint (patient 15). Murakami et al. Synovial Plicae and Temporomandibular Joint. J Oral Maxillofac Surg 2015.
(patients 6 and 7), and calcification was detected in 1 specimen (patients 11, left TMJ). Synovial tissues were observed in 3 specimens (patients 6, 10, and 18; Table 2). Cartilaginous tissue and calcification appeared only in the dislocation group, whereas there was no obvious histologic difference of fibrous and synovial tissues between the dislocation and internal derangement groups.
Discussion The aim of the study was to describe the occurrence and distribution of synovial plicae in the TMJ. The present study showed synovial plicae in 15 of 24 joints in patients with recurrent dislocation (62.5%) and in 3 of 4 patients with Wilkes stage IV and V internal derangement (75%). This study found that these unique plica structures occurred in more than half the surgically exposed TMJs. Because this is the first clinical report of synovial plicae in disordered TMJs, it is difficult to
interpret whether the prevalence of plicae is clinically important in TMJ disorders; therefore, further studies with larger numbers of patients are required. There was no apparent bias toward gender, procedure, or surgical side in the dataset. The average patient with TMJ dislocation was older (mean, 63.2 yr) than the average patient with internal derangement (mean, 44.3 yr). However, in the recurrent dislocation group, the average age of the patients in whom synovial plicae were found was somewhat older (68.1 yr; n = 11) than that in patients in whom synovial plicae were not seen (52.6 yr; n = 5). The importance of this age differential requires larger numbers of such cases.
FIGURE 2. Synovial plica in the left temporomandibular joint grasped by forceps (patient 15).
FIGURE 4. A meniscus-like synovial plica was retracted to the outside using forceps after a lateral cut of the articular tubercle (patient 5).
Murakami et al. Synovial Plicae and Temporomandibular Joint. J Oral Maxillofac Surg 2015.
Murakami et al. Synovial Plicae and Temporomandibular Joint. J Oral Maxillofac Surg 2015.
831
MURAKAMI ET AL
FIGURE 5. Surgical view of tongue-like synovial plica (patient 10). Murakami et al. Synovial Plicae and Temporomandibular Joint. J Oral Maxillofac Surg 2015.
In human TMJ cadaveric studies, tongue-like synovial8 and meniscus-like and crescent-shaped9 plicae have been described, and histologic findings of a few superficial rows of synovial cell lining with areolar subsynovial connective tissues have been reported.10 In
previously published articles, Moses11 described the presence of synovial plicae and lateral impingement syndrome of the TMJ, and Kirk12 reported that large destabilizing plicae were seen in the TMJ impingement cases. However, no descriptions of the prevalence or form of plicae were detailed in either article. In the present study, synovial plicae of different shapes were found in the TMJ, such as broad tonguelike, meniscus-like, fringe-like, and other diverse forms. Further, the plicae detected in the dislocation group seemed to occur mainly at the lateral capsular inner synovial wall and appeared to protrude deep into the upper joint space. Much larger, wider, thicker, and broad and meniscus-like plicae were seen only in cases of recurrent dislocation. Conversely, there were no obvious differences in distribution of fine plicae between the dislocation and internal derangement groups. In the orthopedic knee literature, there are varied descriptions of the thickness, width, rigidity, shape, and form of synovial plicae, and the wider plicae seem to be more likely to be impinged and symptomatic.2,3,6,7 However, it has been stated that no morphologic characteristic allows the assessment of pathologic plicae.1 Whether the wide, thick synovial plicae in TMJ dislocation contribute to any joint disability and symptoms is open to debate and further study. Histologically, the synovial plicae found in this study exhibited mostly fibrous and cartilaginous characteristics. Some exhibited highly hyalinized cartilaginous
FIGURE 6. Type and location of synovial plicae in the upper joint (schematic view of the upper joint space in the left temporomandibular joint viewed from above). A, Meniscus-like synovial plica. B, Broad synovial plica. C, Tongue-like plica. D, Plicae with fringe-like and miscellaneous forms. Murakami et al. Synovial Plicae and Temporomandibular Joint. J Oral Maxillofac Surg 2015.
832
SYNOVIAL PLICAE AND TEMPOROMANDIBULAR JOINT
FIGURE 7. A, Histologic findings of plica from the right temporomandibular joint, featuring avascular dense fibrous tissue (patient 15). B, Hyalinized histopathologic findings of scattered chondroid cells (patient 7) (original magnification, 200). Murakami et al. Synovial Plicae and Temporomandibular Joint. J Oral Maxillofac Surg 2015.
tissue and there was 1 case of calcification in the dislocation group. A synovial cell lining with or without mild inflammation was observed in 3 specimens in each group. In the internal derangement group, 1 specimen exhibited a mildly inflamed synovium with interwoven dense fibrotic tissue; in the dislocation group, 1 specimen showed cartilaginous tissue and another showed fibrous tissue (Table 2). Orthopedic review articles have suggested that in its early stages the histologic appearance of synovial plicae is consistent with an inflamed synovium, whereas in later stages these plicae become fibrotic and possibly symptomatic.1-3,7 However, in a report on the pathologic appearance of resected plicae from the knee, Richmond and McGinty14 found that, of the 45 specimens examined, 19 showed no abnormality, 14 exhibited mild synovitis, 8 showed fibrosis, 3 displayed synovitis and fibrosis, and 1 showed fibrocartilaginous metaplasia. They stated that no correlation was found between the duration of symptoms and the presence of these pathologic changes. Further, Dupont1 stated that plicae should not be considered pathologic, but rather symptomatic or asymptomatic. Although the histopathologic variation of the synovial plicae found in the TMJ in the present study might not be analogous to that found in other joints, new and thought-provoking histopathologic plica variations between TMJ dislocation and internal derangement cases were seen. The explanation and importance of these plicae in TMJ disorders can be found only by further investigations. Synovial plicae of the knee are a common finding during arthroscopy, but are rarely considered responsible for specific signs and symptoms.3 Plica syndrome in the knee is considered a mechanical internal derangement of the patellofemoral articular surfaces,
as are impinged plicae in the elbow radiohumeral joint5 and the shoulder subacromial joint.4 After appropriate workup, arthroscopic excision of these plicae provides good results in these joints. Making analogies between TMJ and orthopedic joint plicae can be problematic and confusing because of the different anatomic, biomechanical, and physiologic natures of the 2 joint systems, especially in light of the 2 different pathologies encountered in this study. However, TMJ synovial plicae were detected; therefore, these findings should be reported so that their role in TMJ disorders can be investigated further. Limitations of this study include its retrospective nature, lack of asymptomatic controls, and the small number of surgically treated internal derangements. Thus, any specific relations between clinical signs or symptoms and synovial plicae cannot be suggested in the study. Regarding preoperative diagnostic imaging, because the devices and machines differed among institutions and conditions, the obtained findings might be less definitive. In summary, various forms of synovial plicae were detected in the TMJs of surgical patients with recurrent dislocation and internal derangement. Their etiology and possible importance in the signs and symptoms of TMJ disorders are unknown, but deserve further study. Acknowledgments The authors are indebted to Drs Hideto Shibaoka, Takeshi Okano, and Kazuyuki Nishimura for their unselfish contributions regarding data collection and clinical discussions on the present investigations. Special thanks to Dr Eiro Kubota for proper advisement and comments on the project. The authors are grateful to Drs Joseph P. McCain and Reem Hamdy Hossameldin for their valuable cooperation in sharing their experiences of TMJ arthroscopic findings of synovial plicae.
MURAKAMI ET AL
References 1. Dupont JY: Synovial plicae of the knee. Controversies and review. Clin Sports Med 16:87, 1997 2. Schindler OS: Synovial plicae of the knee. Curr Orthop 18:210, 2004 3. Kent M, Khanduja V: Synovial plicae around the knee. Knee 17: 97, 2010 4. Funk L, Levy O, Even T, et al: Subacromial plica as a cause of impingement in the shoulder. J Shoulder Elbow Surg 15:697, 2006 5. Ruiz de Luzuriaga BC, Helms CA, Kosinski AS, et al: Elbow MR imaging findings in patients with synovial fringe syndrome. Skeletal Radiol 42:675, 2013 6. Jee WH, Choe BY, Kim JM, et al: The plica syndrome: Diagnostic value of MRI with arthroscopic correlation. J Comput Assist Tomogr 22:814, 1998 7. Garcıa-Valtuille R, Abascal F, Cerezal L, et al: Anatomy and MR imaging appearances of synovial plicae of the knee. Radiographics 22:775, 2002
833 8. Murakami K, Hoshino K: Regional anatomical nomenclature and arthroscopic terminology in human temporomandibular joints. Okajimas Folia Anat Jpn 58:745, 1982 9. Ohmura Y: Histological observations on the structure of the lateral wall of the human temporomandibular joint. J Stomatol 51:465, 1984 (in Japanese). 10. Murakami K, Hoshino K: Histological studies on the inner surface of the articular cavities of human temporomandibular joints with special reference to arthroscopic observations. Anat Anz 160:167, 1985 11. Moses JJ: Lateral impingement syndrome and endaural surgical technique. Oral Maxillofac Surg Clin North Am 1:165, 1989 12. Kirk W: Illustrated surgical techniques for management of impingements of the temporomandibular joint. Int J Oral Maxillofac Surg 42:229, 2013 13. AAOMS ParCare 2012. J Oral Maxillofac Surg 70:e1, 2012, Suppl 3 14. Richmond JC, McGinty JB: Segmental arthroscopic resection of the hypertrophic mediopatellar plica. Clin Orthop Relat Res 178:185, 1983
Synovial Plicae and Temporomandibular Joint Disorders: Surgical Findings KenIchiro Murakami, DDS, DMSc,* Shinsuke Hori, DDS,y Yoshinori Yamaguchi, DDS, PhD,z Louis G. Mercuri, DDS, MS,x Naota Harayama, DDS,k Syouta Maruo, DDS,{ and Tsuneo Takahashi, DDS, PhD# Purpose:
Synovial plicae and their relation to pain and disability have been reported in the orthopedic literature in association with the knee and other extremity joints. However, the occurrence of synovial plicae in the temporomandibular joint (TMJ) have rarely been reported. This report describes the surgical appearance, distribution, and histologic findings of synovial plicae in patients with TMJ recurrent dislocation and internal derangement.
Materials and Methods:
Twenty consecutive patients, 16 with recurrent dislocation and 4 with internal derangement, who underwent open TMJ surgery by the same surgeon from 2010 to 2013 were studied retrospectively.
Results:
Synovial plicae were detected in 18 of 28 joints (64.3%). Synovial plicae were observed in 15 of 24 joints (62.5%) with recurrent dislocation and in 3 of 4 joints (75%) with internal derangement. Histologic findings of these plicae were consistent with dense fibrous or cartilaginous tissues, with some exhibiting a synovial lining.
Conclusions: Although the role of synovial plicae in TMJ disorders is unknown and unstudied, consideration should be given to investigating the possible relation of these structures to the signs and symptoms of TMJ disorders. Ó 2015 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 73:827-833, 2015
In the orthopedic literature, symptomatic synovial plicae have been reported in the knee1-3 and other extremity joints, such as the shoulder4 and elbow.5 Although the common signs and symptoms of impingement in the medial plica of the knee include crepitation, popping, snapping, instability, catching, and pain,1-3 there is major crossover of symptoms and clinical findings associated with more commonly seen diagnoses.3 Thus, the specific diagnosis of plica syndrome is controversial.1-3 The anatomic occurrence and distribution of
plicae in orthopedic joints has been visualized on magnetic resonance imaging (MRI)2,3,5-7; however, MRI has not been able to distinguish between pathologic and nonpathologic plicae.6,7 MRI findings can be useful to evaluate the thickness and extension of plica and synovitis with concomitant effusion.2,5-7 The gold standard for a diagnosis of plicae in orthopedics is arthroscopy followed by excision.1-7 To date, in the literature on the temporomandibular joint (TMJ), only cadaveric studies showing the {Staff Surgeon, Department of Oral and Maxillofacial Surgery,
*Consultant Surgeon, Department of Oral and Maxillofacial Surgery, Ako City Hospital, Visiting Professor, Department of
Kyotango City Kumihama Hospital, Kyotango, Japan.
Maxillofacial Surgery, Kanagawa Dental University, Graduate
#Professor and Head, Department of 3D Imaging Anatomy,
School of Dentistry, Yokosuka, Japan.
Kanagawa Dental University, Ako, Japan.
yChief, Department of Oral and Maxillofacial Surgery, Kyotango
Address correspondence and reprint requests to Dr Murakami:
City Kumihama Hospital, Kyotango, Japan.
Department of Oral and Maxillofacial Surgery, Ako City Hospital,
zChief, Department of Oral and Maxillofacial Surgery, Kusatsu
Nakahiro 1090, Ako city, Hyogo, Japan 678-0232; e-mail: murakeny@
General Hospital, Kusatsu, Japan. xVisiting Professor, Department of Orthopedic Surgery, Rush
yahoo.co.jp Received August 6 2014
University Medical Center, Chicago, IL; Clinical Consultant, TMJ
Accepted December 17 2014
Concepts, Ventura, CA.
Ó 2015 American Association of Oral and Maxillofacial Surgeons
kStaff Surgeon, Department of Oral and Maxillofacial Surgery,
0278-2391/14/01837-0
Kyoto City Hospital Kyoto, Japan. Formerly in the Department of
http://dx.doi.org/10.1016/j.joms.2014.12.018
Oral and Maxillofacial Surgery, Ako City Hospital, Ako, Japan.
827
828 presence, appearance, and histology of synovial plicae can be found.8-10 However, there is little description related to the clinical appearance of synovial plicae in patients with TMJ disorders.11,12 The purpose of this report is to describe the occurrence, distribution, and histologic findings of synovial plicae in patients who underwent open TMJ surgery for recurrent dislocation and internal derangement.
Materials and Methods Twenty consecutive patients, 16 patients with recurrent dislocation and 4 with internal derangement, who underwent open TMJ surgery from 2010 to 2013 were studied retrospectively. The diagnoses and surgical indications for patients with dislocations and internal derangement were based on criteria published by the American Association of Oral and Maxillofacial Surgeons.13 Any patients with a diagnosis of TMJ pathology, such as neoplasm, hyperplasia, rheumatoid arthritis, loose body disease, or ankyloses, were not included. Surgery for recurrent dislocation involved eminectomy; however, 1 patient underwent open repositioning. Discectomy without a disc substitute was used in all internal derangement cases, but 1 patient underwent a discectomy with high condylectomy. All surgeries were performed by the same surgeon (K.M.). The inclusion criteria for patients with internal derangement were nonreducible disc displacement (Wilkes stages III, IV, and V) confirmed by MRI and no response to nonsurgical treatment for at least 6 months. The exclusion criteria were patients whose condition could be managed by arthroscopy or arthrocentesis alone. In all cases, preoperative diagnostic imaging included orthopantomography and 1.5-T MRI with T1-and T2-weighted imaging in the sagittal plane in the closed and open jaw positions with or without coronal sections. For patients with recurrent dislocation, the inclusion criteria were a history of repetitive dislocations for longer than 3 months and no response to nonsurgical treatment, such as a protective bandage, occlusal splint, and observation. Preoperative diagnostic imaging included orthopantomography or computed tomography. MRI was used only when the patient had a history of clicking or limited jaw opening. Fourteen specimens of synovial plica were examined histologically by the department of surgical pathology at each hospital. Only 4 synovial plicae were documented in the surgical record owing to an earlier observation of fine or small plicae. Because of the retrospective nature of this study, it was granted an exemption in writing by the institutional review boards of Ako City Hospital (Ako Japan), the Kyotango Kumihama City Hospital (Kyotango, Japan), and Kusatsu General Hospital (Kusatsu, Japan).
SYNOVIAL PLICAE AND TEMPOROMANDIBULAR JOINT
Results Seven male and 13 female patients 25 to 85 years old (mean, 59.45 yr) were included in the study. Twentyeight 28 joints (12 unilateral and 8 bilateral) underwent open surgery. Patients 6, 12, and 13 had a diagnosis of bilateral recurrent dislocation by history; however, at surgery, these dislocations were found to be unilateral (Table 1). The average age of the 16 patients with TMJ dislocation was 63.2 years. This group consisted of 24 joints (8 unilateral and 8 bilateral). Signs and symptoms included condylar hypermobility with recurrent dislocations and 1 bilateral persistent dislocation. These patients reported pain only when their mandibles were dislocated. Eminectomy was performed in 15 patients, and 1 patient underwent bilateral discectomy and joint repositioning owing to persistent joint dislocation with the damaged disc. Four patients (mean, 44.3 yr of age) had internal derangement (3 with Wilkes stage IV and 1 with Wilkes stage V). All underwent discectomy, but 1 patient also underwent high condylectomy because of a ruptured disc and a deformed condyle. All these patients had signs and symptoms of internal derangement, limited mandibular opening with deviation to the affected side, and limited mandibular lateral and protrusive excursions. However, none had any atypical pain complaints that might be associated with entrapment of synovial plicae. Synovial plicae were seen in 14 patients (18 of 28 total operated joints [64.3%]; Table 2). Fifteen synovial plicae were seen in 11 patients (mean, 68.1 yr old; 15 of 24 joints [62.5%]) with recurrent dislocation. Plicae were not detected in 5 patients (mean, 52.6 yr old). In 3 (mean, 42.6 yr old) of the 4 patients with closed-lock internal derangements (2 with Wilkes stage IV and 1 with stage V), synovial plicae were detected in 3 of 4 joints (75%). At preoperative diagnostic imaging, there were no obvious specific findings relating to the presence of synovial plicae. At surgery, the synovial plicae found were typically broad (Figs 1-3), meniscus-like (Fig 4), or tongue-like (Fig 5) in shape. Seven were tongue-like, 4 had a broad form, 1 had a meniscus-like and fringe-like shape, and the other 5 were amorphous in shape (Table 2). The plicae were broader in the dislocation than in the internal derangement group. Four broad plicae were found in 2 cases (patients 11 and 15); 1 meniscus-like plica (patient 5) and 1 fringe-like plica (patient 7) were detected only in the dislocation group. These plicae presented as relatively thick, wide, pliable areolar tissue lying within the lateral para-discal recess (groove) and intruding into the upper joint space (Fig 6A-C). No obvious differences in the form and shape of fine
829
MURAKAMI ET AL
Table 1. OPEN SURGICAL CASES OF THE TEMPOROMANDIBULAR JOINT
Case 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Age (yr)
Gender
Diagnosis
Procedure
Side
Wilkes Stage
25 31 70 62 46 85 67 84 85 75 70 53 63 65 73 58 40 40 49 48
M F M F M F F F F F M F F M M F F M F F
Re, D Re, D B, Re, D Re, D B, Re, D B, Re, D Re, D B, Re, D B, D Re, D B, Re, D B, Re, D B, Re, D B, Re, D B, Re, D B, Re, D ID ID ID ID
eminec eminec eminec eminec eminec eminec eminec eminec reposition eminec eminec eminec eminec eminec eminec eminec discectomy discectomy discectomy discectomy + high condylectomy
L R B L B R L B B L B L R B B B L R R L
IV IV IV V
Abbreviations: B, bilateral; D, dislocation; eminec, eminectomy; F, female; ID, internal derangement; L, left; M, male; R, right; Re, recurrent. Murakami et al. Synovial Plicae and Temporomandibular Joint. J Oral Maxillofac Surg 2015.
tongue-like or other amorphous plicae were found (Fig 6D). Regarding the histopathologic finding of the plicae, the most consistent finding (12 of 14 specimens) was
dense fibrous tissues (Fig 7A) with scattered cartilaginous cells (Fig 7B, Table 2). These findings were frequently observed in association with hyalinization. Distinct cartilaginous tissue was found in 2 specimens
Table 2. CASES OF DETECTED SYNOVIAL PLICAE
Case
Age (yr)
Gender
Surgical Procedure
Side and Form
Histology
4 5 6 7 9
62 46 85 67 85
F M F F F
eminec eminec eminec eminec reposition
10 11
75 70
F M
eminec eminec
13 14 15
63 65 73
F M M
eminec eminec eminec
16
58
F
eminec
17 18 20
40 40 48
F M F
discectomy discectomy discectomy + high condylectomy
L, small tongue-like L, meniscus-like tongue-like L, small fringe R, small tongue-like L, small tongue-like L, tongue-like R, broad L, broad R, miscellaneous L, miscellaneous R, broad L, broad R, miscellaneous L, miscellaneous L, small tongue-like R, tongue-like L, miscellaneous
non fibrous cartilaginous + synovium cartilaginous non non synovium + fibrous R, fibrous L, fibrous + calcification fibrous L, fibrous R, fibrous L, fibrous R, fibrous L, fibrous non R, synovium + fibrous L, fibrous
Abbreviations: eminec, eminectomy; F, female; L, left; M, male; non, no histologic examination; R, right. Murakami et al. Synovial Plicae and Temporomandibular Joint. J Oral Maxillofac Surg 2015.
830
FIGURE 1. Broad synovial plica in the right temporomandibular joint (patient 15). Murakami et al. Synovial Plicae and Temporomandibular Joint. J Oral Maxillofac Surg 2015.
SYNOVIAL PLICAE AND TEMPOROMANDIBULAR JOINT
FIGURE 3. Synovial plicae removed from the right and left sides of the temporomandibular joint (patient 15). Murakami et al. Synovial Plicae and Temporomandibular Joint. J Oral Maxillofac Surg 2015.
(patients 6 and 7), and calcification was detected in 1 specimen (patients 11, left TMJ). Synovial tissues were observed in 3 specimens (patients 6, 10, and 18; Table 2). Cartilaginous tissue and calcification appeared only in the dislocation group, whereas there was no obvious histologic difference of fibrous and synovial tissues between the dislocation and internal derangement groups.
Discussion The aim of the study was to describe the occurrence and distribution of synovial plicae in the TMJ. The present study showed synovial plicae in 15 of 24 joints in patients with recurrent dislocation (62.5%) and in 3 of 4 patients with Wilkes stage IV and V internal derangement (75%). This study found that these unique plica structures occurred in more than half the surgically exposed TMJs. Because this is the first clinical report of synovial plicae in disordered TMJs, it is difficult to
interpret whether the prevalence of plicae is clinically important in TMJ disorders; therefore, further studies with larger numbers of patients are required. There was no apparent bias toward gender, procedure, or surgical side in the dataset. The average patient with TMJ dislocation was older (mean, 63.2 yr) than the average patient with internal derangement (mean, 44.3 yr). However, in the recurrent dislocation group, the average age of the patients in whom synovial plicae were found was somewhat older (68.1 yr; n = 11) than that in patients in whom synovial plicae were not seen (52.6 yr; n = 5). The importance of this age differential requires larger numbers of such cases.
FIGURE 2. Synovial plica in the left temporomandibular joint grasped by forceps (patient 15).
FIGURE 4. A meniscus-like synovial plica was retracted to the outside using forceps after a lateral cut of the articular tubercle (patient 5).
Murakami et al. Synovial Plicae and Temporomandibular Joint. J Oral Maxillofac Surg 2015.
Murakami et al. Synovial Plicae and Temporomandibular Joint. J Oral Maxillofac Surg 2015.
831
MURAKAMI ET AL
FIGURE 5. Surgical view of tongue-like synovial plica (patient 10). Murakami et al. Synovial Plicae and Temporomandibular Joint. J Oral Maxillofac Surg 2015.
In human TMJ cadaveric studies, tongue-like synovial8 and meniscus-like and crescent-shaped9 plicae have been described, and histologic findings of a few superficial rows of synovial cell lining with areolar subsynovial connective tissues have been reported.10 In
previously published articles, Moses11 described the presence of synovial plicae and lateral impingement syndrome of the TMJ, and Kirk12 reported that large destabilizing plicae were seen in the TMJ impingement cases. However, no descriptions of the prevalence or form of plicae were detailed in either article. In the present study, synovial plicae of different shapes were found in the TMJ, such as broad tonguelike, meniscus-like, fringe-like, and other diverse forms. Further, the plicae detected in the dislocation group seemed to occur mainly at the lateral capsular inner synovial wall and appeared to protrude deep into the upper joint space. Much larger, wider, thicker, and broad and meniscus-like plicae were seen only in cases of recurrent dislocation. Conversely, there were no obvious differences in distribution of fine plicae between the dislocation and internal derangement groups. In the orthopedic knee literature, there are varied descriptions of the thickness, width, rigidity, shape, and form of synovial plicae, and the wider plicae seem to be more likely to be impinged and symptomatic.2,3,6,7 However, it has been stated that no morphologic characteristic allows the assessment of pathologic plicae.1 Whether the wide, thick synovial plicae in TMJ dislocation contribute to any joint disability and symptoms is open to debate and further study. Histologically, the synovial plicae found in this study exhibited mostly fibrous and cartilaginous characteristics. Some exhibited highly hyalinized cartilaginous
FIGURE 6. Type and location of synovial plicae in the upper joint (schematic view of the upper joint space in the left temporomandibular joint viewed from above). A, Meniscus-like synovial plica. B, Broad synovial plica. C, Tongue-like plica. D, Plicae with fringe-like and miscellaneous forms. Murakami et al. Synovial Plicae and Temporomandibular Joint. J Oral Maxillofac Surg 2015.
832
SYNOVIAL PLICAE AND TEMPOROMANDIBULAR JOINT
FIGURE 7. A, Histologic findings of plica from the right temporomandibular joint, featuring avascular dense fibrous tissue (patient 15). B, Hyalinized histopathologic findings of scattered chondroid cells (patient 7) (original magnification, 200). Murakami et al. Synovial Plicae and Temporomandibular Joint. J Oral Maxillofac Surg 2015.
tissue and there was 1 case of calcification in the dislocation group. A synovial cell lining with or without mild inflammation was observed in 3 specimens in each group. In the internal derangement group, 1 specimen exhibited a mildly inflamed synovium with interwoven dense fibrotic tissue; in the dislocation group, 1 specimen showed cartilaginous tissue and another showed fibrous tissue (Table 2). Orthopedic review articles have suggested that in its early stages the histologic appearance of synovial plicae is consistent with an inflamed synovium, whereas in later stages these plicae become fibrotic and possibly symptomatic.1-3,7 However, in a report on the pathologic appearance of resected plicae from the knee, Richmond and McGinty14 found that, of the 45 specimens examined, 19 showed no abnormality, 14 exhibited mild synovitis, 8 showed fibrosis, 3 displayed synovitis and fibrosis, and 1 showed fibrocartilaginous metaplasia. They stated that no correlation was found between the duration of symptoms and the presence of these pathologic changes. Further, Dupont1 stated that plicae should not be considered pathologic, but rather symptomatic or asymptomatic. Although the histopathologic variation of the synovial plicae found in the TMJ in the present study might not be analogous to that found in other joints, new and thought-provoking histopathologic plica variations between TMJ dislocation and internal derangement cases were seen. The explanation and importance of these plicae in TMJ disorders can be found only by further investigations. Synovial plicae of the knee are a common finding during arthroscopy, but are rarely considered responsible for specific signs and symptoms.3 Plica syndrome in the knee is considered a mechanical internal derangement of the patellofemoral articular surfaces,
as are impinged plicae in the elbow radiohumeral joint5 and the shoulder subacromial joint.4 After appropriate workup, arthroscopic excision of these plicae provides good results in these joints. Making analogies between TMJ and orthopedic joint plicae can be problematic and confusing because of the different anatomic, biomechanical, and physiologic natures of the 2 joint systems, especially in light of the 2 different pathologies encountered in this study. However, TMJ synovial plicae were detected; therefore, these findings should be reported so that their role in TMJ disorders can be investigated further. Limitations of this study include its retrospective nature, lack of asymptomatic controls, and the small number of surgically treated internal derangements. Thus, any specific relations between clinical signs or symptoms and synovial plicae cannot be suggested in the study. Regarding preoperative diagnostic imaging, because the devices and machines differed among institutions and conditions, the obtained findings might be less definitive. In summary, various forms of synovial plicae were detected in the TMJs of surgical patients with recurrent dislocation and internal derangement. Their etiology and possible importance in the signs and symptoms of TMJ disorders are unknown, but deserve further study. Acknowledgments The authors are indebted to Drs Hideto Shibaoka, Takeshi Okano, and Kazuyuki Nishimura for their unselfish contributions regarding data collection and clinical discussions on the present investigations. Special thanks to Dr Eiro Kubota for proper advisement and comments on the project. The authors are grateful to Drs Joseph P. McCain and Reem Hamdy Hossameldin for their valuable cooperation in sharing their experiences of TMJ arthroscopic findings of synovial plicae.
MURAKAMI ET AL
References 1. Dupont JY: Synovial plicae of the knee. Controversies and review. Clin Sports Med 16:87, 1997 2. Schindler OS: Synovial plicae of the knee. Curr Orthop 18:210, 2004 3. Kent M, Khanduja V: Synovial plicae around the knee. Knee 17: 97, 2010 4. Funk L, Levy O, Even T, et al: Subacromial plica as a cause of impingement in the shoulder. J Shoulder Elbow Surg 15:697, 2006 5. Ruiz de Luzuriaga BC, Helms CA, Kosinski AS, et al: Elbow MR imaging findings in patients with synovial fringe syndrome. Skeletal Radiol 42:675, 2013 6. Jee WH, Choe BY, Kim JM, et al: The plica syndrome: Diagnostic value of MRI with arthroscopic correlation. J Comput Assist Tomogr 22:814, 1998 7. Garcıa-Valtuille R, Abascal F, Cerezal L, et al: Anatomy and MR imaging appearances of synovial plicae of the knee. Radiographics 22:775, 2002
833 8. Murakami K, Hoshino K: Regional anatomical nomenclature and arthroscopic terminology in human temporomandibular joints. Okajimas Folia Anat Jpn 58:745, 1982 9. Ohmura Y: Histological observations on the structure of the lateral wall of the human temporomandibular joint. J Stomatol 51:465, 1984 (in Japanese). 10. Murakami K, Hoshino K: Histological studies on the inner surface of the articular cavities of human temporomandibular joints with special reference to arthroscopic observations. Anat Anz 160:167, 1985 11. Moses JJ: Lateral impingement syndrome and endaural surgical technique. Oral Maxillofac Surg Clin North Am 1:165, 1989 12. Kirk W: Illustrated surgical techniques for management of impingements of the temporomandibular joint. Int J Oral Maxillofac Surg 42:229, 2013 13. AAOMS ParCare 2012. J Oral Maxillofac Surg 70:e1, 2012, Suppl 3 14. Richmond JC, McGinty JB: Segmental arthroscopic resection of the hypertrophic mediopatellar plica. Clin Orthop Relat Res 178:185, 1983
