Arthroscopic surgery has evolved significantly since it was first introduced by Ohnishi. It is a very safe and minimally invasive way to provide many levels of treatment on patients who would historically require open surgical techniques with much higher complication rates. The most important indication for diagnostic and operative arthroscopy is pain and dysfunction that cannot be reversed through conservative measures. Regardless of disease stage, it allows the surgeon to make a diagnosis through direct visualization of the joint, simultaneously perform lavage, manipulate structures (e.g., break adhesions), take biopsies, and thoroughly debride or reconstruct the joint as indicated by the preoperative and intraoperative diagnosis. Absolute contraindications to arthroscopy include bony ankylosis, preauricular skin infection, or preauricular tumor.
Arthroscopy is performed at three different surgical levels based on the diagnosis and surgeon experience. Level I is a single posterolateral puncture technique where the scope is introduced and a diagnostic sweep completed to visualize all important structures and a patent irrigation portal is maintained to lavage the joint. Level II is a double-puncture technique with an additional anterolateral puncture site for passageway of instrumentation. Level IIIa is a double or triple puncture technique, which allows for scope entry in the posterior port and large diameter instrumentation in an anterior port for advanced debridement or partial meniscectomy in end- stage disease. Level IIIb is a reconstructive arthroscopy whereby an arthroscopic discopexy is completed.
In performing this procedure, patient preparation and correct positioning are paramount. The patient’s preauricular surgical site should be parallel to the floor so that the operator has the advantage of recognizing all anatomical landmarks. An ear wick should be in place to avoid otologic injury. Each step is carefully designed to maintain the safety of the procedure and to obtain more information about the joint space. First, the intra and extra-articular landmarks must be identified via manipulation of the jaw. Then while the mandible is distracted, 2% lidocaine in a 3.5 cc syringe with a 27 g needle is injected into the joint for insufflation from an inferolateral approach until 0.5 cc rebound is achieved (Fig. 11.7a).
After insufflation, the first puncture is placed at the maximum concavity of the glenoid fossa (Fig. 11.7b). Every puncture into the joint is incredibly technique sensitive as this is when the surgeon can cause significant iatrogenic damage to the joint if not executed properly. The trocar is rotated carefully through subcutaneous tissues until it reaches the lateral aspect of temporal bone; then it is used as a periosteal elevator to release the periosteum before gently sliding into the glenoid fossa and superior joint space. The maximum entry length of the trocar should never pass 25 mm measured from the surface of the integument or this can violate the structures medial to the joint capsule such as the middle ear. The authors cannot stress how important this puncture is in the success of this procedure. If not performed properly, it can lead to damage to adjacent structures and iatrogenic injury to the fibrocartilage and bone of the joint, and additionally, with multiple punctures this can lead to extravasation of fluid making it incredibly difficult to maintain any insufflation for the rest of the procedure.
Once inside the joint, the trocar is removed and the joint is gently backwashed with lactated ringer’s solution and 1:300,000 epinephrine to remove any clot before inserting the scope. This irrigating fluid is used for the remainder of the case. To establish a patent outflow system, the surgeon inserts a 22 gauge 1.5 inch needle approximately 5 mm anterior and 5 mm inferior from the scope port. Then the procedure can commence with an initial lavage which is completed with 120 cc of irrigating fluid (Fig. 11.7c). Once completed, the operator should perform the diagnostic sweep to evaluate all seven points of interest in the superior joint space for abnormal pathology including disc position, degeneration of structures, or inflammatory markers (Fig. 11.7d). After reaching the anterior recess, the operator can inject medication and conclude the procedure. The authors prefer to inject hyaluronic acid for Wilkes II-IV and PRP for Wilkes V stage patients.
If the operator is to continue to level II arthroscopy, a second port needs to be obtained. This is placed in the most anterior lateral aspect of the joint to ensure maximum flexibility of the instrumentation passed through it. The puncture site is identified using triangulation principles with the scope in the anterior recess focused on the most anterior lateral aspect of the joint space. The vectors of instrument orientation here create an equilateral triangle, facilitating a repeatable and safe pattern of placement for second puncture. The depth of the arthroscope is assessed from the cannula. While the scope is held still, attention is drawn back
Fig. 11.7 (a) Insufflation with local anesthetic. (b) Trocar and sharp cannula. (c) Level I arthroscopy with arthroscope and irrigating needle. (d) Triangulating and identification of irrigating needle to the skin, and a measuring cannula is laid flat against the skin with the tip (0 mm marking) in contact with the scope at point of entry while the depth of penetration is translated to this measuring cannula for a second port site (Fig. 11.8a). While the assistant insufflates the joint, the operator uses first an irrigating needle to sound the position of the port and subsequently removes it to place the trocar in the same confirmed position. This limits the amount of injury to structures inside the joint and creates less extravasation, as the needle is 22 gauge diameter compared to the 2.0 mm diameter of the cannula. The trocar is then rotated through skin and advanced at the same angulation as the irrigating needle was placed under direct visualization of the scope so that again no intra-articular structures are injured (Fig. 11.8b).
At this stage of the operation, several Level II procedures can be performed including synovial biopsy, disc manipulation, minor debridement, and contracture (Fig. 11.9a, b). In level II procedures, a contracture can be performed to tighten the lax retrodiscal tissues of a dislocated disc. Contracture can be performed via chemical (sclerosing agent) or mechanical means. The authors do not advocate the use of chemical contracture because even though it is targeted in the retrodiscal tissue, the potential for compromising the vascular supply and initiating condylar resorption or DJD exists. Contracture by mechanical means, however, is a safe and successful procedure in Wilkes II, III, and IV patients. It is performed using coblation or laser. The coblation or laser must target the redundant retrodiscal tissues, oblique protuberance, and superficial vasculature to obtain maximum effect. It is imperative that the surgeon understand and identify the appropriate intra-articular landmarks prior to contracture.
Level IIIa debridement can be achieved simply by switching out the 2.0 s puncture cannula for a 3.0 system to clean joints with arthrofibrosis, synovial
Fig. 11.8 (a) Level II arthroscopy with triangulation to identify second puncture site. (b) Level II arthroscopy with instrumentation hyperplasia, chondromalacia stages III and IV, and ankylosing osteoarthritis (Fig. 11.10a-d). It is best to start in the anterior recess and work to the posterior by opening and increasing joint space. Debridement is achieved using hand instrumentation such as curettes or bone files, holmium laser, motorized mini shavers and abraders, coblation therapy, bipolar and monopolar electrocautery, and suction punches. Level III procedures should only be performed by experienced arthroscopic surgeons.
Historically, the most common complication of arthroscopy is iatrogenic scuffing of the fibrocartilage covering the eminence and fossa because every step beginning with insufflation is aimed to reach the maximum concavity of the glenoid fossa
Fig. 11.9 (a) Arthroscopic synovial biopsy. (b) Arthroscopic coblation to create mechanical contracture
Fig. 11.10 (a) Grade III chondromalacia. (b) Grade IV chondromalacia. (c) Fibrous adhesion, chondromalacia, synovitis, and plicae. (d) Grade IV chondromalacia and perforation. (A backslope of the eminence, B chondromalacia, C condylar head, D edge of disc perforation)
Fig. 11.10 (continued)
(Fig. 11.11a, b). During insufflation, the tip of the needle is directed toward the posterior slope of the eminence, making contact with the fibrocartilage to confirm anatomic position prior to deposition. If performed more than once, and with hasty hand, it can result in scuffing of the articulating surfaces of the fossa. After insufflation, the first puncture involves elevating the periosteum over the lateral aspect of the zygomatic arch and penetrating the capsule at the greatest concavity of the fossa with the sharp trocar. If this is not positioned correctly and is too anterior, it can scuff and injure the posterior slope of the eminence and if it is done with too much force, it can scuff the fibrocartilage of the glenoid fossa or even puncture into the middle cranial fossa. Arthroscopic cadaver studies have shown the incidence of minor scuffing of the articular surface to be between 36 and 50% [19-21]. It follows that the goal is to avoid or minimize scuffing in order to maximize the success of the procedure. Although fibrocartilage has some limited self-reparative properties through regeneration of collagen and proteoglycans, it remains unclear whether regeneration or further degeneration occurs . Additionally, significant scuffing can decrease visibility for the surgeon during procedure and can cause misdiagnosis by inexperienced surgeons.
Fig. 11.11 (a) Arthroscopic scuffing and iatrogenic chondromalacia. (b) Arthroscopic scuffing and iatrogenic chondromalacia
Fig. 11.12 Complete “white out” from fibrous ankylosis
A second complication that can cause disease progression if not handled properly is hemarthrosis leading to fibrous ankylosis (“white out” joint) (Fig. 11.12). Hemarthrosis can be caused by excessive bleeding into the joint space during puncture from tearing of the superficial temporal vessels, from tearing of severely inflamed synovium/retrodiscal tissue upon entrance, and from bleeding of the pterygoid artery during lateral pterygoid myotomy in level IIIb procedures. Although extremely rare, the bleeding can be severe enough to cause termination of the procedure . Typically, pressure and irrigation in addition to some other measures can control bleeding and allow for continuation of the procedure with good visualization of the joint. If hemorrhage is not properly addressed, it will lead to a joint congested with blood. This prolongs healing, increases postoperative discomfort, extends recovery time, and can ultimately lead to fibrous ankylosis.
When hemorrhage inhibits visualization during the procedure, there is a clear protocol to follow. If there is a pointed source, cautery or laser can be used to seal the vessel. If there is not, insufflate the joint with irrigating fluid and/or hyaluronic acid and cover the outflows of the cannulas for 5 min so that sufficient pressure develops to tamponade the bleeding site. If bleeding continues, remove all instruments from the joint and apply direct, external pressure to the preauricular area for an additional 5 min. After 5 min passes, reinsert the instruments and assess the joint. If bleeding still continues, it may be possible to insert a No. 4 catheter balloon through the second portal. Inflate the balloon with normal saline and leave it for 5 min; then deflate and again assess the joint space. Finally, if bleeding still persists, the joint should be approached via open surgery and the area should be packed and any bleeding vessels clamped or cauterized. It is rare in experienced hands to require transition to open surgery as most conservative measures generally work to tamponade bleeding. To avoid fibrous ankylosis in these patients, it is of utmost importance to begin them on a rigorous physical therapy regimen postoperative day 1 and follow them closely throughout the first 6 weeks of healing.
Level IIIb arthroscopy is reserved for the carefully selected patient. It may be beneficial in these situations. The ideal candidate has no signs of active inflammation or primary arthritis and has a Wilkes II or early Wilkes III derangement. This may in fact be there first surgical intervention when the disc displacement is thought to be the primary source of their symptoms. If performed in patients who are late Wilkes III, Wilkes IV, or Wilkes V, have primary inflammatory arthritis, or have active inflammation or joint effusion, the success of the procedure significantly decreases. This is likely the result of persistent inflammation which can cause scarification and adhesions during healing. Therefore, in a patient with active inflammation, it is important to first scope and lavage the joint; then when it is quiescent, if the patient is still symptomatic or closed lock recurs, discopexy can be performed.
Arthroscopic discopexy is performed by first establishing the glenoid fossa and anterior recess portals. Then once inside the anterior recess, the surgeon must identify the disc crease - this is where the disc abuts the lateral pterygoid muscle medially. The surgeon then completes the lateral pterygoid myotomy or anterior release with laser and electrocautery to control bleeding (Fig. 11.13a, b). It is
Fig. 11.13 (a) Identify the disc crease with a probe. (b) Lateral pterygoid myotomy with a laser important to identify exactly where the disc crease is for two reasons. First, one of the most common complications here can be injury to the disc itself. Second, if the laser is aimed too high into the muscle belly where the vasculature is, this will cause increased bleeding into the joint. Once this is completed, the surgeon brings the scope and instrumentation into the posterior recess to reduce the disc (Fig. 11.14). While the disc is being reduced, two additional smaller ports are obtained. One port is to pass the suture through the disc and the other is to catch the suture (Fig. 11.15). Suture materials have varied from polypropylene suture to wire. Once the suture or wire has been successfully passed through the disc and secured into place, mechanical contracture of the retrodiscal tissue is performed with laser or coblation (Fig. 11.16).
As the disc is the most manipulated anatomical structure in this procedure, one would think it is at risk for injury. However, damage to it is very unlikely when entering the joint space or executing the procedure if the surgeon does not deviate from the standard techniques. The only part of the procedure which violates the disc fibrocartilage itself is during the actual suturing where small perforations into the disc are made with a 20 gauge needle which will heal with time.
Fig. 11.14 Disc reduction in the posterior recess
Fig. 11.15 Catching the suture as it is passed through the disc
Fig. 11.16 Mechanical contracture of lax retrodiscal tissue with laser