J Oral Maxill ofac Surg44:614-617.1986

Temporomandibular Joint ArthroscopyALASTAIR N. GOSS, DDSe, FRACDS, DOS,* AND ARTHUR G. BOSANQUET, BDSt

The surgical technique for arthroscopic examination of the superiorspace of the temporomandibular joint and the morbidity encountered withthe procedure in 50 cases are presented. Eighty-eight per cent of the ex­aminations provided diagnostic information. There were no serious com­plications, and minor short-term complaints were encountered in only12% of the examinations.

Arthroscopy of the human temporomandibularjoint (TMJ) was first described by Ohnishi in 1975.1

Subsequently cadaver studies--' and case reportsv"indicate that arthroscopy is a diagnostic techniqueof considerable merit in the management of TMJdisorders. Apart from the original publication ofOhnishi,' which was in Japanese, there has beenlittle detailed information on the surgical techniqueand the complications that may be encountered.Cadaver studies have confirmed the risk of damageduring TMJ arthroscopy.l-' but no large clinicalstudies of the morbidity associated with the proce­dure have been performed. This paper describesthe arthroscopic procedure, which was modifiedfrom the original Ohnishi technique after a series ofcadaver and animal studies, and reports the sur­gical difficulties and the complications encounteredin a series of 50 consecutive cases.

Instrumentation

The specialized instrumentation is shown inFigure 1. The arthroscope (S.E.S.-SelfroscopeS.E.S.-17H; external diameter, 1.7 mm; OlympusOptical Company, Tokyo, Japan) and cameracannot be heat-sterilized or totally immersed incold sterilizing solutions as these procedures woulddamage the optics. The instrument is cleaned withlukewarm surgical soap solution, and the arthro­scope tip is sterilized in 2% glutaraldehyde solutionfor not more than 20 minutes. The remaining sur­faces of the arthroscope and camera, except for thelens surfaces, are wiped with 70% alcohol.

* Senior Lecturer and t Resident. Oral and Maxillofacial Sur­gery. Depa rtment of Denti stry, The Univers ity of Adelaide,South Australia .

Address corre spondence and reprint requests to Dr. Goss:Oral and Maxillofacial Surgery, Department of Dentistry, GPOBox 498, The University of Adelaide. Adelaide, South Australia5001.

614

Procedure

Patients are examined under anesthesia inducedvia nasoendotracheal intubation . When arthros­copy is the only procedure performed, it is done onan outpatient basis. The mandibular condyle istranslated anteriorly by placement of a large mouthprop so that interincisal distance is 30 mm.

The preauricular region is shaved, if necessary,and the area is surgically disinfected and isolatedwith sterile drapes. The operating table is hori­zontal, and the patient's head is rotated away fromthe side to be examined. The surgeon and assistantsit on either side of the patient 's head . A ruler isplaced along a line from the midpoint of the tragusto the lateral canthus . Two points are marked onthe line, either with a surgical marking pen or bypuncturing the skin with a disposable needle. Thefirst point (point A) is 10 mm and the second (pointB) 15 mm from the tragus.

For hemostasis, 1 ml of 2% lidocaine containing1:80,000 adrenalin is infiltrated into the area. A 21­gauge 1.5-inch (0.81 x 38-mm) needle is inserted atpoint A (Fig. 2). The needle is inserted for 5 mm at90° to the surface and then adv anced 15 to 20 mmanteriorly and superiorly at 45° to the skin. If boneis contacted, the needle is withdrawn 1 to 2 mm,the angle of approach changed, and the needle ad­vanced so that the joint space is entered (Fig. 3a).

A 20-ml syringe filled with sterile isotonic salineis connected to the needle by an extension tube,and 1 to 2 ml is slowly injected . The skin over thejoint is palpated during the injection. If the needleis correctly placed it is possible to inject only 1 to 2ml before resistance is encountered. If it is incor­rectly placed, larger volumes can be injected , andthe excess solution is felt with the palpating fingeras it distends the extracapsular tissues. The objectof this injection is to distend the joint space; the

GOSS AND BOSANQUET 615

FIGURE I (top). Instrumentation: I, light source; 2, arthro­scope; 3, irrigating set (two required)-20-ml syringe, 30-cm ex­tension tube, 21-gauge needle; 4, biopsy forcep, sharp stylet. ob­turator, cannula; 5, camera (lead omitted).

FIGURE 2 (bottom). Needle inserted at point A, 10 mm frommidpoint of the tragus along the tragus-lateral canthus line.Cannula inserted at point B, 5 mm from point A along thetragus-lateral canthus line.

5-,.r-/j 4./r

""

o.y~ ~ .. '

"~ : ~ ..;;:-. -. -~. -.

'~ . - - _ . -J ~

~ ~ -.-- . e..:;.. --- - -~-

minimal amounts of solution, consistent with clearvision of the joint space, are used.

The essential findings of the examination can berecorded by still color photography (Fig. 4). Thisrequires an unscrubbed assistant to alter the lightsource settings on the instructions for the surgeon.Alternatively, the findings can be continuously re­corded by cinecamera or video recorder.

Small pieces of tissue may be obtained for histo­pathologic or biochemical analysis. This is doneblindly by using the punch biopsy forceps throughthe cannula. It is not difficult to obtain tissue fromthe posterior fornix of the upper joint space, butconsiderable experience and practice are requiredto grasp floating bodies within the joint space or tosever fibrous adhesions. Alternatively, biopsy canbe performed under direct vision by passing asecond cannula between points A and B.

On completion of the examination the arthro-

distention is maintained by continued pressure onthe syringe plunger.

At point B a 2-mm vertical stab incision is madethrough the skin. The sharp stylet enclosed in thecannula is inserted through the incision to a depthof 5 mm at 90° to the surface. The stylet is thendirected anteriorly and superiorly at 45°. If bone iscontacted it is withdrawn slightly and the angle ad­justed, and it is then readvanced until the joint cap­sule is penetrated. As soon as the joint capsule ispenetrated, the sharp stylet is withdrawn, and theblunt stylet is inserted into the cannula and ad­vanced into the joint space. If both the needle andthe cannula are appropriately placed, sterile salineshould flow from the cannula as it is slowly injectedvia the needle (Fig. 3b). If this does not occur theneither the needle or the cannula is not in the supe­rior joint space, and they must be repositioned toestablish the circuit.

It is essential that the stylet be used properly toavoid tissue damage. It is held in the palm of thehand, with the index finger along the cannula. Inthis manner, if the instrument should slip past thebone, penetration deep into the infratemporal fossais prevented. Once the lateral capsule is pene­trated, the blunt stylet is used. This minimizesintra-articular damage and prevents puncture of thethin medial capsule.

After the cannula has been placed properly, thesyringe is disconnected from the needle, and theend of the extension tube is placed in a kidney dishat the side of the patient's head. A second syringeand connecting tube are attached to the cannula.Thus, the initial fluid flow is reversed, allowing it tobe flushed into the joint space immediately adjacentto the arthroscope tip and exhausted via the needleat point A into the collecting dish (Fig. 3c). Thearthroscope is then placed into the cannula. Themain operating room lights are turned off, leavingonly background lighting behind the operator. Thearthroscope light source is turned on and the posi­tion of the patient altered as necessary, and, oncethe operator's eyes have accommodated, arthro­scopic examination commences. This requires ad­vancement, withdrawal, and alteration of the angu­lation of the arthroscope,' with care not to withdrawif from the joint capsule. The mouth prop is re­moved and the mandible manipulated by the assis­tant. The assistant also gently flushes solutionthrough the joint space and ensures by observationand palpation that solution is not being extrava­sated into the periarticular tissues. It is importantthat the surgeon and assistant communicate witheach other so that the arthroscopic findings can becorrelated with the mandibular position and so that

616 TMJ ARTHRCJCOPY

Results

Discussion

forward but remained in the glenoid fossa. In theremaining case, in which there was a long history ofchronic pain and limitation, it was found after sur­gical exploration that the disc was completely de­tached posteriorly. Thus, the condyle was wedgeddirectly against the glenoid fossa. In the remainingtwo nondiagnostic cases , both of which were as­sessed early in the series, it was not possible to es­tablish satisfactory placement of the needle andcannula, and arthroscopy was not attempted.

In six of the 50 arthroscopic examinations therewere minor short-term complications. In threecases persistent intraoperative bleeding from abranch of the superficial temporal artery occurred.The bleeding did not interfere with the arthroscopicexamination and was controlled by firm pressurefor 5 minutes after removal of the cannula. In threeadditional cases persistent pain and swelling re­solved spontaneously within one week. This wasdue to excessive periarticular extravasation of irri­gating solution. There was no infection, facialparesis, or gross exacerbation of the presentingsymptoms. Most patients recovered rapidly, andthe patients with chronic pain had some diminutionof symptoms. The patients who underwent both ar­throscopy and arthrography complained of greaterdiscomfort from the arthrography.

This paper presents the surgical details of asimple and reliable technique for arthroscopic ex­amination of the superior joint space of the TMJ.The technique is equally applicable to at least oneother brand of arthroscope (Needle Arthroscope;External diameter, 2.4 mm; R. Wolf Co, West Ger­many), although distraction at the angle may be re­quired to allow entrance of the larger cannula intothe joint space. The anatomic landmarks werefound to be sufficiently consistent to ensure place­ment of the instrument within the joint spacewithout involving vital anatomic structures. Thiswas confirmed in a cadaver study! in which it wasfound that the ideal puncture site was 2 mm (range,0-6 mm) below the tragus-canthal line, with -anaverage depth from skin to capsule of 27 mm(range, 18-33 mm). The wide variation in depth ofpenetration was related directly to the amount ofadipose tissue present. Dissections confirmed thatthe puncture sites did not interfere with the tem­poral artery or veins, or with the temporal branchesof the facial nerve. Occasionally, particularly in pa­tients with developmental abnormalities of the face,the landmarks may be misleading. We recently en­countered one patient with a developmentalanomaly involving the joint and ears in whom use

A ' " I ~Bt t'-----1 r-

d

ba

c

Fifty joints (in 31 patients) were examined ar­throscopically. The patients ranged in age from 9 to63 years, and 21 were female. All 50 joints weresymptomatic, with chronic pain that had failed torespond to appropriate conservative treatment in 28and acute trauma in 22. Six of the 50 examinationswere nondiagnostic. In four of the six, gross abnor­malities of the joint space prevented introduction ofthe cannula. Three of them were cases of acutetrauma, with displaced fractures of the ipsilateralcondylar process. Thus. although the mouth waswide open, the detached condyle did not translate

scope is withdrawn, and the main lights are turnedon . The joint space is then irrigated by reversingthe fluid flow so that any floating material withinthe joint space is irrigated out via the cannula (Fig.3d). In osteoarthritic joints, or in other conditionsassociated with considerable intra-articular debris,the joint space should be irrigated thoroughly withat least 100 ml of sterile isotonic saline.

The puncture wounds do not require suturing.During surgery, I million units of penicillin IV, or asuitable alternative if the patient is allergic to peni­cillin, is administered. The external auditorymeatus should be checked with an otoscope, andany blood that may have flowed into the ear fromthe puncture points should be removed. The patientis placed on a soft diet, given mild analgesics, andadvised not to make wide jaw-opening movementsduring the first few postoperative days.

FIGURE 3. Technique for arthroscopy. a. Needle inserted atpoint A. Superior joint space distended by I to 2 ml sterilenormal saline via irrigation jet. b. Cannula inserted at point Bwith sharp stylet and then obturator. Fluid flushed through jointfrom point A to B. c, Arthroscope inserted into cannula. Flowreversed and flushed past arthroscope tip from pint B to point A.d, Arthroscopy complete. Fluid flow reversed to flush out debrisfrom joint space.

GOSS AND BOSANQUET

of the usual landmarks resulted in penetrationabove the zygomatic arch.

In the report of Ohnishi;! the patients wereseated, and arthroscopy was performed with localanesthesia and nitrous oxide sedation. This facili­tates orientation, and the patient can move the jawrather than having it manipulated. Although wehave since used intravenous sedation and an au­riculotemporal local anesthetic block, our patientswere generally very resistant to having the proce­dure performed while they were conscious. Cer­tainly, general anesthesia is appropriate while thisdemanding technique is being mastered, and it isalso preferable if a brisk temporal vessel bleedoccurs.

It was found that irrigation via a syringe was con­trolled much more easily than the gravity-fed dripsystem that has been described.' Most cadaverstudies use either air2,3 or nitrogen to distend thejoint space. This is because cadaver material ismuch more rigid and joint surface tissues morefragmented. We have not used gas, mainly becauseof our concern about creating an air embolus.

Arthroscopy is performed mainly in the superiorjoint space, because this space has twice thevolume of the inferior space" and is opened poste­riorly as the mandible translates forward; in addi­tion, the converse superior surface of the disc doesnot interfere with the insertion of instruments. Thisis a limitation of the technique, although it has beenreported that the abnormalities of the temporal sur­face are either similar to or more advanced thanthose on the condylar surface.f

Arthroscopy of the inferior joint space requiresonly minor modification of the technique used forthe superior joint space. The mandible is protrudedas far anteriorly as possible, with the teeth onlyslightly apart. The needle and cannula are insertedat the same points but are directed inferiorly andposteriorly at 45° rather than anterosuperiorly. Be­cause the joint space is smaller and the disc is bell­shaped, the potential for damage to the disc is muchgreater. At this stage, we recommend that arthros­copy of the inferior joint space be performed onlyin patients in whom surgical exploration is planned.

This study shows that very little morbidity is as­sociated with arthroscopy; no significant damagefrom the procedure was observed either arthro­scopically or in 11 of the 12 cases in which surgicalexploration was done following arthroscopy. In onecase in which there were two grooves on the con­dyle, resistance was encountered during attemptsto enter the joint space. This was the case men­tioned previously in which the disc was totally dis­placed anteriorly and condylar translation was pre­vented. Cadaver studies have reported a 36% inci-

617

FIGURE 4. Arthroscopy of normal superior joint space. Discin foreground, articular surface of glenoid fossa superior.

dence of minor scratches and a 12% incidence ofdamage to the posterior disc tissue.' This higher in­cidence probably relates to the unyielding qualityof fixed cadaver tissue. The importance of correctfinger positioning during placement of the stylet isillustrated by the cadaver study.' Those authors re­ported one instance of penetration of the medialcapsule of the joint. Clearly, if such uncontrolledpenetration occurred, the probable damage to vitalstructures in the carotid sheath and intratemporalregion could be disastrous.

Generally, there was good correlation betweenthe arthroscopic diagnosis and that made by clinicaland radiologic investigation. In a cadaver study adiagnostic accuracy of 100% for osteoarthritis and57% for remodeling changes was reported.' We alsofound excellent correlation between preoperativearthroscopic and surgical findings.

References

I. Ohnishi M: Arthroscopy of the temporomandibular joint (inJapanese). J Jpn StomatoI42:207, 1975

2. Murakami K, Hoshino K: Regional anatomical nomencla­ture and arthroscopic terminology in human temporoman­dibular joints. Okajimas Folia Anat Jpn 58:745, 1982

3. Holmund A, Hellsing G: Arthroscopy of the temporoman­dibular joint-an autopsy study. Int J Oral Surg 14:169,1985

4. Ohnishi M: Clinical application of arthroscopy in the tempo­romandibular joint diseases. Bull Tokyo Med Dent Univ27:141, 1980

5. Murakami K, Matsumoto K, Lutzuka J: Suppurative ar­thritis of the temporomandibular joint. A report of a casewith special reference to arthroscopic observations. JMaxillofac Surg 12:41, 1984

6. Hellsing G, Holmlund A, Nordenstram A, et a1: Arthros­copy of the temporomandibular joint-examination of 2patients with suspected disk derangement. Int J Oral Surg13:69, 1984

7. Vickers P, Goss AN: Day stay oral surgery. Aust Dent J13(3):135, 1983

8. Blackwood HJJ: Pathology of the temporomandibular joint.J Am Dent Assoc 79:118, 1969