Elbow Arthroscopy: Basic Setup and Portal Placement S ince the first reports of elbow ar- throscopy in the American liter- ature, 1,2 advances in arthroscopic technique and equipment have made elbow arthroscopy an effective and safe method for the diagnosis and treatment of a variety of elbow ailments. 3 With elbow arthroscopy becoming more common, precise knowledge of the neurovascular anatomy, preferred arthroscopic por- tals, and considered indications for definitive arthroscopic procedures is required to maximize the success rate and improve the clinical out- come. Indications and Contraindications Diagnostic indications include in- flammatory arthritis, loose bodies, degenerative and traumatic arthritis, and intra-articular fractures. Thera- peutic indications include removal of loose bodies, synovectomy, tennis elbow release, débridement of osteo- chondritis dissecans of the capitel- lum, radial head excision, and man- agement of arthritis of the elbow (osteophyte excision and contracture release). 4-6 Evolving indications in- clude capsulectomy for arthrofibro- sis, instability management, and percutaneous pinning of fractures. Contraindications to elbow ar- throscopy include distortion of nor- mal bony or soft-tissue anatomy, making safe portal placement diffi- cult. 5 Extensive heterotopic ossifica- tion is a contraindication to elbow arthroscopy because of the frequent- ly extensive anatomic distortion and the usual necessity for open treat- ment of the associated extracapsular contractures of the elbow. Previous submuscular or subcutaneous trans- position of the ulnar nerve is a rela- tive contraindication for safe intro- duction of the arthroscope or cannula through the medial side of the elbow. In these cases, identifica- tion of the ulnar nerve is necessary before establishing a medial portal. Surgical Technique Prior to surgery, a thorough preoper- ative evaluation is performed to de- termine the presence of elbow insta- bility, heterotopic bone in the olecranon fossa or anterior capsule, ligamentous laxity, and range of mo- tion. As in any surgical procedure, the key to avoiding complications in elbow arthroscopy is to have a clear understanding of the relationship of the neurovascular structures to the topographic anatomy. 7 Because the elbow is a subcutaneous joint, it is easy to palpate the bony landmarks before surgery—specifically, the me- dial epicondyle, lateral epicondyle, olecranon process, radial head, and location of the ulnar ner ve (Figure 1). Anesthesia Most surgeons prefer to use gen- eral anesthesia for patients undergo- ing elbow arthroscopy because it pro- vides total muscle relaxation and is comfortable for the patient. Some physicians avoid the use of regional anesthesia because the patient’s postoperative neurologic status can be difficult to assess and may be compromised by an extended axil- lary or supraclavicular nerve block. 8 We prefer regional blocks, such as axillary blocks, for postoperative pain control. If there has been a pre- vious nerve injury or nerve transfer, general anesthesia alone is preferred. Infrequently, we have observed com- plete but usually transient ulnar nerve palsy following elbow arthros- Joseph A. Abboud, MD Eric T. Ricchetti, MD Fotios Tjoumakaris, MD Matthew L. Ramsey, MD Dr. Abboud is Clinical Assistant Profes- sor of Orthopaedic Surgery, Department of Orthopaedic Surgery, Pennsylvania Hospital, University of Pennsylvania Health System, Philadelphia, PA. Dr. Ricchetti is Orthopaedic Surgery Resi- dent, Department of Orthopaedic Sur- gery, University of Pennsylvania School of Medicine, Philadelphia. Dr. Tjou- makaris is Orthopaedic Surgery Resi- dent, Department of Orthopaedic Sur- gery, University of Pennsylvania School of Medicine. Dr. Ramsey is Associate Professor of Orthopaedic Surgery and Chief, Shoulder and Elbow Service, De- partment of Orthopaedic Surgery, Uni- versity of Pennsylvania School of Medi- cine. None of the following authors or the departments with which they are affiliated has received anything of value from or owns stock in a commercial company or institution related directly or indirectly to the subject of this article: Dr. Abboud, Dr. Ricchetti, Dr. Tjoumakaris, and Dr. Ramsey. Reprint requests: Dr. Abboud, Department of Orthopaedic Surgery, 3B Orthopaedics, Pennsylvania Hospital, University of Pennsylvania Health System, 800 Spruce Street, 8th Floor Preston, Philadelphia, PA 19107. J Am Acad Or thop Surg 2006;14:312- 318 Copyright 2006 by the American Academy of Orthopaedic Surgeons. The video that accompanies this article is “Elbow Arthros- copy: Basic Setup and Portal Placement,” available on the Orthopaedic Knowledge Online Web- site, at http://www5.aaos.org /oko/jaaos/ surgical.cfm Surgical Techniques 312 Journal of the American Academy of Orthopaedic Surgeons copy. In patients in whom we used an axillary nerve block, nerve activ- ity could not be accurately deter- mined postoperatively. Instrumentation A standard 4.0-mm, 30° offset ar- throscope permits excellent visual- ization of the elbow joint. A smaller 2.7-mm arthroscope typically is not necessary but can be useful for view- ing small spaces, such as the lateral compartment from the direct lateral portal, and for arthroscopy in adoles- cent patients. Side-vented inflow cannulas should be avoided in elbow arthros- copy because the distance between the skin and the joint capsule is of- ten very slight. With side-vented cannulas, the cannula can be intra- articular while the side vents remain extra-articular, resulting in fluid ex- travasation into the surrounding soft tissues. Inflow cannulas should be devoid of side vents, with fluid flow occurring directly at the end of the cannula 9 (Figure 2, A). All trocars are conical and blunt- tipped to decrease the possibility of neurovascular and articular injury. A variety of accessory handheld instru- ments (eg, probes, grasping forceps, Figure 1 Surface landmarks of the elbow for arthroscopy. Posterior view of the elbow hinged over a support padded bolster. A, The medial epicondyle, ulnar nerve, and olecranon process are outlined in relation to the elbow joint. B, The lateral epicondyle, radial head, and olecranon process are outlined in relation to the elbow joint. Figure 2 A, Inflow cannulas. Side vented inflow cannulas (right) should be avoided because the side vents may lie outside of the elbow joint, resulting in fluid extravasation into the surrounding soft tissues. Fluid flow should occur from the end of the cannula (left). B, Elbow arthroscopy instruments. Clockwise from upper left: irrigation system; grasping forceps, and grasping and cutting punches; plastic and metal trocars and cannulas for port al dilation and exposure; and 20-mL irrigation syringe, triangulation probe, spinal needle. (Panel A reproduced with permission from Ramsey ML, Naranja RJ: Diagnostic arthroscopy of the elbow, in Baker CL Jr, Plancher KD [eds]: Operative Treatment of Elbow Injuries. New York, NY: Springer-Verlag, 2002, p 165.) Joseph A. Abboud, MD, et al Volume 14, Number 5, May 2006 313 punches) and motorized instruments (eg, arthroscopic radial-sided cutting shavers, end-cutting burrs) are used during elbow arthroscopy (Figure 2, B). Patient Position Patients may be positioned in one of four ways for elbow arthroscopy: supine, supine-suspended, prone, and lateral decubitus. Each position has its advantages and disadvantag- es. We prefer the lateral decubitus position because it provides im- proved stability of the extremity and posterior elbow joint access without compromising airway access. 5,7 Arthroscopy Setup After general anesthesia is admin- istered, the patient is placed in the lateral decubitus position with the involved extremity facing upward (Figure 3, A). The arm is supported and stabilized on a padded bolster with the shoulder abducted to 90° and the elbow flexed to 90°. A tour- niquet is placed proximally on the arm with the pressure set at 250 mm Hg. The extremity is sterilely pre- pared and draped free to allow intra- operative manipulation. To mini- mize fluid extravasation into the forearm, the forearm is wrapped with an elastic bandage from the fin- gers to just below the elbow. The bony landmarks of the elbow and the portal sites are marked on the skin before joint distention (Fig- ures 1 and 3) ( video step 1).An 18-gauge needle is inserted through the lateral “soft spot,” which is bounded by the lateral epicondyle, ra- dial head, and olecranon process (Fig- ure 3, B). Using this site, the elbow is then distended with 15 to 25 mL of sterile saline. Joint insufflation in- creases the distance between the joint surfaces and neurovascular structures, helping to protect vessels and nerves from injury during joint entry 10 ( video step 2). Impor- tantly, joint distention does not in- crease the distance between the joint capsule and adjacent neurovascular structures and, therefore, does not protect the neurovascular structures from work performed against the joint capsule. Distention of the joint can be confirmed by elevation of the elbow capsule anteriorly and poste- riorly. Return of fluid from the nee- dle when the stylus is removed also confirms that the joint space has been entered and capsular distention obtained. Distention of the joint with more than 15 to 25 mL of fluid risks capsular rupture, resulting in poor ar- throscopic visualization and fluid ex- travasation during arthroscopy. 11 Portal Placement Neurovascular injury is a primary concern with elbow arthroscopy and can occur with any of the described portal sites. Several surgeons have described creating various portals around the elbow with the intention of decreasing the risk of neurovascu- lar injury while maintaining ade- quate intra-articular visualiza- tion. 1,2,5,12 The initial por tal for joint visual- ization is a matter of surgeon prefer- ence but is dictated to some extent by the underlying pathology to be ad- dressed. Some elbow surgeons de- scribe initial visualization of the pos- terolateral recess from the soft-spot portal, then progressing to the poste- rior compartment of the elbow before moving to the anterior compartment. Most elbow surgeons, however, pre- fer to visualize the anterior compart- ment of the elbow first, then the pos- terior compartment, and finally the posterolateral recess to complete joint visualization. We find that ini- tially observing the radiocapitellar Figure 3 A, After the administration of general anesthesia, the patient is placed in the lateral decubitus position with the surgical elbow supported and stabilized on a padded bolster (shoulder abducted to 90° and elbow flexed to 90°). B, Prior to beginning arthroscopy, distention of the elbow joint is performed through the lateral soft spot, bounded by the lateral epicondyle, radial head, and olecranon process. Elbow Arthroscopy: Basic Setup and Portal Placement 314 Journal of the American Academy of Orthopaedic Surgeons and ulnohumeral joints aids in intra- articular orientation. Whether the anteromedial or an- terolateral portal should be created first has been an issue of some de- bate. Many surgeons create a lateral portal initially and then establish a medial portal with a spinal needle by direct visualization from within the joint. Alternatively, an inside-out technique may be employed in which a switching stick is used to es- tablish the medial portal from inside the joint. 13 Other surgeons, using the same techniques, establish the me- dial portal first. 14 We create a medial portal first and then establish the lat- eral portal under direct visualization with the aid of a spinal needle. We think that the medial approach is safer because the average distance between the medial portals and the median nerve is greater than the dis- tance between the lateral portals and the radial or posterior interosseous nerve. 13,14 Proximal Anteromedial (Superomedial) Portal The proximal anteromedial (or su- peromedial) portal popularized by Poehling et al 2 is located just anterior to the intermuscular septum and 2 cm proximal to the medial epi- condyle (Figure 4, A). The ulnar nerve is located approximately 3 to 4 mm from this portal, posterior to the in- termuscular septum. Palpating the septum and making sure that the portal is established anterior to Figure 4 A, The proximal anteromedial portal (or superomedial portal) is just anterior to the intramuscular septum and 2 cm proximal to the medial epicondyle. Care must be taken to avoid the ulnar nerve. B, The anteromedial portal is approximately 2 cm anterior and 2 cm distal to the medial epicondyle. This portal augments the proximal anteromedial portal and is helpful for working in the medial recess of the elbow. Care must be taken to avoid the medial antebrachial cutaneous nerve. Figure 5 A, The proximal anterolateral portal is 1 to 2 cm proximal to the lateral epicondyle, just anterior to the lateral supracondylar column of the distal humerus. This proximal position minimizes the risk of radial nerve injury. B, The anterolateral portal also is favored to decrease the risk of radial nerve injury. Compared with the proximal anterolateral portal, this placement is more proximal and somewhat anterior. Creating this portal under direct visualization, after establishment of a medial portal, helps avoid injury to lateral structures. Joseph A. Abboud, MD, et al Volume 14, Number 5, May 2006 315 the septum minimizes the risk of in- jury to the nerve while providing ex- cellent visualization laterally of the radiocapitellar joint. The proximal anteromedial portal is safer than the anteromedial portal because the more proximal position allows the arthroscope to be directed distally, re- sulting in the arthroscope’s being al- most parallel to the median nerve in the anteroposterior plane. 14 The ar- throscope is inserted through this portal, and systematic examination of the anterior compartment is then performed. The capitellum and radial head are inspected; the forearm is ro- tated to evaluate the medial and lat- eral surfaces of the radial head. The anterior and lateral aspects of the capsule are viewed next by slowly withdrawing the arthroscope. A tri- angulation probe can help evaluate the trochlea, coronoid fossa, and coronoid process ( video step 3). Anteromedial Portal The anteromedial portal 1 is locat- ed 2 cm anterior and 2 cm distal to the medial epicondyle (Figure 4, B). The anteromedial portal is used pri- marily to augment the proximal an- teromedial portal when instrumen- tation of the medial recess of the elbow is required. This portal place- ment allows for excellent visualiza- tion of the lateral elbow joint, as well as of the proximal capsular in- sertion. The neurovascular structure at greatest risk when establishing this portal is the medial antebrachi- al cutaneous nerve. Proximal Anterolateral Portal Field et al 12 described a proximal anterolateral portal, 1 to 2 cm prox- imal to the lateral epicondyle, di- rectly on the anterior humerus (Fig- ure 5, A). This portal brings the arthroscope into the lateral aspect of the joint at an angle that allows visu- alization of the medial aspect of the joint, radiocapitellar joint, and later- al recess ( video step 4). In prac- tice, anterior portal placement from the lateral side of the elbow can oc- cur anywhere from the sulcus be- tween the radial head and capitel- lum to a point 2 cm proximal to the lateral epicondyle, along the anteri- or aspect of the humerus, without placing the radial nerve at increased risk. 12 In fact, the risk of neurovascu- lar injury decreases as the portal is moved more proximally. Anterolateral Portal The anterolateral portal was orig- inally described as being located 3 cm distal and 2 cm anterior to the lateral epicondyle. 1 However, this portal location places the radial nerve at significant risk for iatrogen- ic injury. 15 To decrease risk of injury to the radial nerve, several investiga- tors have stressed the importance of avoiding the distal placement of this portal in favor of a more proximal placement of the anterolateral por- tal, at the sulcus between the capi- tellum and the radial head 12 (Figure 5, B). Posterocentral Portal The posterocentral portal is locat- ed 3 cm proximal to the tip of the Pearls and Pitfalls Methods to avoid complications associated with elbow arthroscopy: 16 • Define anatomic landmarks before joint distention. • Recognize that distention increases the distance between the distal humerus and the joint capsule, thereby increasing the bone-to-nerve distance. Joint distension does not, however, increase the distance between the joint capsule and the nerves. Joint distension increas- es the safety of portal placement, but it does not protect the nerves from transcapsular procedures. • Use of proximally placed portals reduces neurovascular risk. 17 • Use only blunt trocars. The trocar and sheath should be directed to- ward the center of the joint. • When incising the skin to create portals, avoid penetrating the sub- cutaneous tissue to prevent injury to the superficial cutaneous nerves. • Use a hemostat or mosquito clamp to spread tissues down to the capsule. • Keep the elbow flexed 90° to increase the distance between the nerves and the capsule. • Do not use pressurized infusion systems. They can cause capsular rupture, extra-articular fluid extravasation, and obstruction of joint visualization. 18 • Always visualize your instrument tip. • Use a retractor introduced into the joint through a separate portal to lift the capsule away from the débriding instrument. • Use of retractors for greater visualization and exposure is probably most important in preventing nerve injury. 16 • In some cases, safe surgery requires ar throscopic identification of nerves. This technique is reserved for the most experienced elbow arthroscopists. Novice arthroscopists attempting to arthroscopically identify nerves or attempting to perform surgery that requires nerve identification are more likely to injure the nerves they are attempt- ing to protect. This is particularly true with the ulnar nerve. • Avoid suction when working against the capsule. This may cause capsular collapse and inadvertent nerve injury. • Use of local anesthetics around the portals can produce local neu- ral deficits that may confuse the postoperative neurologic status of the patient. Elbow Arthroscopy: Basic Setup and Portal Placement 316 Journal of the American Academy of Orthopaedic Surgeons olecranon in the midline (Figure 6, A). It pierces the triceps muscle just above the musculotendinous junc- tion and provides excellent visual- ization of the entire posterior com- partment of the elbow, including the medial and lateral gutters ( video step 5). The straight posterior portal passes within 23 mm of the posteri- or antebrachial cutaneous nerve and within 25 mm of the ulnar nerve. Posterolateral Portal (Proximal Posterolateral Portal) This portal is located 2 to 3 cm proximal to the tip of the olecranon at the lateral border of the triceps ten- don (Figure 6, B). The trocar is di- rected toward the olecranon fossa, passing through the triceps muscle to reach the capsule. This portal permits visualization ofthe olecranontip, olec- ranon fossa, and posterior trochlea, but the posterior capitellum is not well seen. The medial and posterior antebrachial cutaneous nerves are the two neurovascular structures most at risk; they are, on average, approxi- mately 25 mm from this portal. 15 The ulnar nerve is approximately 25 mm from this portal medially but is safe as long as the cannula is kept lateral to the posterior midline. 3 Accessory Posterolateral Portals The posterolateral anatomy of the elbow allows for portal placement anywherefromtheproximalpostero- lateral portal to the lateral soft spot (Figure 6, C). Altering the portal po- sition along the line between the proximal posterolateral portal and lateral soft spot changes the orienta- tion of the portal relative to the Figure 6 A, The posterocentral portal, the safest portal, is placed in the midline 3 cm proximal to the tip of the olecranon process. B, The posterolateral portal (or proximal posterolateral portal) is 2 to 3 cm proximal to the tip of the olecranon process at the lateral border of the triceps tendon. The medial and posterior antebrachial cutaneous nerves are most at risk. C, Accessory posterolateral portals may be placed anywhere along a line from the site of the proximal posterolateral port al to the site of the lateral soft spot distally. D, The direct lateral port al (or soft-spot portal) is at the center of the triangle formed by the lateral epicondyle, olecranon process, and radial head. Care must be taken to avoid the posterior antebrachial cutaneous nerve. Joseph A. Abboud, MD, et al Volume 14, Number 5, May 2006 317 joint. These portals are particularly useful for gaining access to the pos- terolateral recess. 7 Direct Lateral Portal (Soft-Spot Portal) This portal is located at the soft spot: the center of the triangle formed by the lateral epicondyle, olecranon process, and radial head (Figure 6, D). As discussed earlier, this portal is often used for joint dis- tention. One can create this portal under direct visualization with the use of a spinal needle. The closest neurovascular structure to the portal is the posterior antebrachial cutane- ous nerve, which passes approxi- mately 7 mm from the portal. The soft-spot portal allows visualization of the inferior aspect of the capitel- lum and the inferior portion of the radioulnar articulation. Establishing this portal is an essential component to a complete arthroscopic examina- tion of the elbow. Complications Although rare and often transient, nerve injuries are the most com- monly reported complications of el- bow arthroscopy. 1,15,19 These can be a result of direct injury from the tro- cars and instruments used, or they can result from overly aggressive joint distention/fluid extravasation, compression caused by arthroscopic sheaths, or use of local anesthesia. 1,15 More specifically, the radial nerve is at risk for injury during placement of the anterolateral portal. Injuries to the radial nerve, the superficial branch of the radial nerve, and the posterior interosseous nerve have been reported. 15,20,21 The median nerve is susceptible to injury during placement of the anteromedial por- tal; injuries to the median and ante- rior interosseous nerves also have been documented. 1,15,22 Damage to the ulnar nerve after the use of mul- tiple medial portals has been report- ed. Finally, injury t o superficial cuta- neous nerves about the elbow (ie, medial, lateral, anterior, and posteri- or antebrachial cutaneous nerves) re- sulting in neuroma formation has been described. 15 Summary and Conclusions Diagnostic and surgical arthroscopy of the elbow has become an accepted treatment modality for numerous conditions about the elbow. 8 Arthros- copy is most successful for removing loose bodies. However, as with any surgical procedure, careful preopera- tive planning, including a detailed history and physical examination, and careful portal placement are nec- essary to ensure a successful surgical outcome. The surgeon’s experience, skill level, and knowledge of local anatomy should determine the com- plexity of elbow arthroscopy cases at- tempted. Elbow arthroscopy cur- rently serves as an adjunct therapy to open surgical procedures in the treat- ment of a variety of elbow condi- tions. 8 New indications for elbow ar- throscopy are likely to emerge as surgical equipment and techniques are refined and as the clinical expe- rience of elbow surgeons increases. References Citation numbers printed in bold type indicate references published within the past 5 years 1. Andrews JR, Carson WG: Arthroscopy of the elbow. Arthroscopy 1985;1:97- 107. 2. Poehling GG, Whipple TL, Sisco L, Goldman B: Elbow arthroscopy: A new technique. Arthroscopy 1989;5: 222-224. 3. 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Ogilvie-Harris DJ, Weisleder L: Fluid pump systems for arthroscopy: A comparison of pressure control versus pressure and flow control. Arthroscopy 1995;11:591-595. 19. Poehling GG,Ekman EF: Arthroscopy of the elbow. Instr Course Lect 1995; 44:217-223. 20. Papilion JD, Neff RS, Shall LM: Com- pression neuropathy of the radial nerve as a complication of elbow ar- throscopy: A case report and review of the literature. Arthroscopy 1988;4: 284-286. 21. Thomas MA, Fast A, Shapiro D: Radi- al nerve damage as a complication of elbow arthroscopy. Clin Orthop Relat Res 1987;215:130-131. 22. Ruch DS, Poehling GG: Anterior in- terosseus nerve injury following el- bow arthroscopy. Ar throscopy 1997; 13:756-758. Elbow Arthroscopy: Basic Setup and Portal Placement 318 Journal of the American Academy of Orthopaedic Surgeons