Over the past several years, the indications for elbow arthroscopy have expanded. Currently, elbow arthroscopy is used for the removal of loose bodies, the treatment of lateral epicondylitis, synovectomy, the debridement of osteophytes, the evaluation of instability contracture release, and the treatment of osteochondritis dissecans1-5.
Although elbow arthroscopy is a relatively safe procedure, the prevalence of neurovascular complications has been reported to range from 0% to 14%1,3,6-9. In the literature, there have been a few reports of complete nerve transections during elbow arthroscopy6-9. We recently reported the case of a patient who presented from an outside institution after undergoing a revision arthroscopic contracture release that resulted in a complete transaction of the ulnar nerve10.
A thorough understanding of the elbow anatomy and how it is affected by certain abnormalities can reduce the risk of complications associated with elbow arthroscopy. Elbows with a posttraumatic contracture have a decreased compliance of the capsule, resulting in limited displacement of neurovascular structures with insufflation. These effects should be thoroughly considered during portal placement and capsular debridement, especially because most reported complications have occurred in patients with posttraumatic contractures6-11. On the medial side of the elbow, it is imperative that the location of the ulnar nerve be identified prior to the placement of medial-side portals. This can be done by means of direct palpation, ultrasonography, or open exposure12. Dodson et al. recommended avoiding an arthroscopic procedure if the patient has undergone a previous ulnar nerve transposition1.
If there has been previous surgery on the lateral aspect of the elbow, it has been suggested that an arthroscopic procedure not be attempted because of possible adherence of the radial nerve to the anterior aspect of the capsule13. Congenital abnormalities of the elbow should be considered to be a relative contraindication because the neural structures may be in unexpected locations. We also recommend extreme caution when performing an arthroscopic release if the patient has undergone a previous open contracture release.
Complications following elbow arthroscopy cannot be eliminated, but they can be minimized substantially by following a systematic approach to the procedure that includes use of the procedure for the correct indications, thorough preoperative preparation, the availability of all necessary equipment, and use of the proper surgical technique.
Positioning
Regional or general anesthesia can be used for elbow arthroscopy. We typically use regional anesthesia consisting of an auxiliary block with intravenous sedation. This allows for supine positioning and maximizes postoperative analgesia.
We utilize a modified supine-suspended position with the shoulder in 90° of flexion and the elbow in 90° of flexion. The forearm and wrist are supported over the chest by a hydraulic arm positioner (SPIDER Limb Positioner; Tenet Medical Engineering, Calgary, Alberta, Canada) attached to the contralateral side of the bed (Figs. 1 and 2). This device allows for rigid positioning of the upper extremity and does not compromise access to the anterior or posterior compartment. This position allows gravity to assist with displacing the anterior neurovascular structures away from the anterior capsule, and the radial nerve is displaced anteriorly with the elbow in 90° of flexion. Other advantages of the supine position include access to the airway for anesthesia and easy conversion to an open arthrotomy without repositioning. When an arthrotomy is required, the forearm is released from the hydraulic device and is placed on an armboard. A medial or lateral approach to the elbow can then be performed.
Principles
A variety of portals can be used, depending on the abnormality being addressed, and the surgeon must understand the associated risks of each. Several studies have examined the proximity of the portals to the neurovascular structures surrounding the elbow14-16. Commonly used portals are the anterolateral, midlateral (soft spot), anteromedial, proximal medial, proximal lateral, transtricipital, and accessory posterior lateral portals (Figs. 3, 4, and 5). The region of elbow abnormality will dictate which portals are chosen.
Following the induction of anesthesia and positioning, the elbow joint is insufflated with 20 to 30 mL of saline solution, which is injected into the soft spot of the midlateral portal. Distention of the articular capsule and elbow flexion increases the distance between the portals and the normal anatomic location of the neurovascular structures. This displacement is significantly decreased when the patient has a joint capsule contracture, and the insufflation volume may be as low as 5 mL17. Once insufflation has been performed, we begin diagnostic arthroscopy of the anterior compartment.
Anterior Arthroscopy
We establish a proximal medial or a proximal lateral portal initially. The proximal medial portal is placed 2 cm proximal to the medial epicondyle and 5 mm anterior to the intermuscular septum (Figs. 3, 4, and 5). The intermuscular septum is palpated prior to the incision to ensure that the portal is anterior to it. By staying anterior to the intermuscular septum and 2 cm proximal to the medial epicondyle, the ulnar nerve stays posterior to the portal18,19 (Fig. 6). Only the skin is incised with a number-15 scalpel blade. After the skin incision is performed, a blunt hemostat is placed on the anterior surface of the humerus and is passed distally, aiming toward the tip of the coronoid. Staying on the anterior aspect of the humerus provides protection of the ulnar nerve behind the intermuscular septum and avoids the median nerve that is a few millimeters anterior to the medial aspect of the brachialis muscle (Fig. 6). Stothers et al. showed that the medial antebrachial nerve is an average of 2.3 mm away when the trocar for the proximal medial portal is inserted and that the brachial artery is an average of 18 mm away when the elbow is in flexion14. A sheath and conical trocar are then used to pierce the capsule. Once the arthroscope is inserted, this portal provides excellent visualization of the radiocapitellar articulation and the anular ligament (Fig. 7). As the arthroscope is withdrawn, the tip of the coronoid and the medial aspect of the elbow can be evaluated. With the arthroscope in the joint, the lateral portals can be established under direct visualization.
An anteromedial portal is very infrequently used. This portal is placed 2 cm distal and 2 cm anterior to the medial epicondyle and is within 5 mm of the medial antebrachial nerve14. We believe that the visualization is not improved when compared with the proximal medial portal and that the risk of nerve injury is greater.
We visualize the anterior compartment through the proximal lateral portal initially if the patient has undergone an ulnar nerve transposition, if the patient is being evaluated for valgus extension overload, or prior to medial collateral ligament reconstruction to rule out any intra-articular abnormality. This portal is located 2 cm proximal to the lateral epicondyle and lies directly on the anterior surface of the humerus. The posterior branch of the antebrachial cutaneous nerve is an average of 6.1 mm away from the proximal lateral portal when the skin incision is made within 1 to 2 mm proximal of the lateral epicondyle. This portal should be placed with the elbow in flexion as the radial nerve will be farther out of danger14.
For patients who have undergone an ulnar nerve transposition, we use elbow arthroscopy for limited indications (i.e., diagnostic arthroscopy, removal of a loose body) that can be addressed through only laterally based portals. Steinmann reported using medially based portals for these patients following identification of the nerve with ultrasound or through an extended medial incision prior to establishing a medial portal12. However, even without prior surgery, we avoid the placement of a posteromedial portal because of the risk of neurovascular injury.
Following completion of the anterior arthroscopy, the arthroscope can be placed in a midlateral portal. However, we generally do not use a midlateral portal except to approach an osteochondral defect of the capitellum. Rather, we view the posterior radiocapitellar joint from the posterolateral portal by sliding the arthroscope down the elbow gutter with the elbow extended. This allows for examination of the posterior radiocapitellar joint, the radioulnar articulation, the lateral gutter, the trochlea, and the trochlear groove. A 2.7-mm arthroscope is occasionally required to evaluate these areas in some patients.
Posterior Arthroscopy
For the evaluation of the posterior compartment, the arm is placed in a more extended position and a posterolateral portal is established. The extended position reduces the tension of the triceps and facilitates placing the trocar toward the olecranon fossa. There are multiple options for a posterior lateral portal, and more than one may be required (Figs. 3 and 4). These portals are 15 to 20 mm from all mixed and major cutaneous nerves14 (Fig. 8). We usually place our first portal 2 to 3 cm proximal to the tip of the olecranon and lateral to the triceps tendon. A transtricipital portal is established as a working portal for any work that needs to be completed in the posterior compartment. This is a straight posterior portal that is located in the midline and 2 to 3 cm proximal to the tip of the olecranon (Fig. 4). Frequently, a motorized shaver is inserted through the transtricipital portal and soft-tissue debridement of the olecranon fossa is required to improve visualization of the posterior compartment (Fig. 9).
The medial, lateral, and central aspects of the olecranon are examined for osteophytes. Then the olecranon fossa and the posteromedial aspect of the humeral condyle are visualized for corresponding abnormalities. The medial and lateral gutters are also examined to complete the diagnostic arthroscopy.
Capsular Release
Arthroscopic capsular releases can be more technically demanding than addressing conditions that are not affected by decreased capsular compliance. The decreased compliance results in a reduction of the intracapsular working space and less displacement of neurovascular structures with insufflation. These effects should be thoroughly considered during portal placement and capsular debridement.
For these patients, we begin with the arthroscope in the anterior compartment, releasing the joint capsule and adhesions from the anterior aspect of the humerus. This can be initiated by having the arthroscope in the proximal medial portal and using a blunt trocar to define and elevate the capsular attachment from the proximal lateral portal. An oscillating full-radius shaver is used to remove adhesions and to debride within the anterior compartment. At this point, we use gravity for suction in order to reduce the risk of over-aggressive debridement of the lateral aspect of the elbow. Once sufficient working space has been established, the coronoid process can be evaluated for osteophytes limiting flexion. A motorized burr is used to resect the osteophytes from the coronoid tip, and the coronoid fossa is cleared of tissue. An anterior capsulectomy is the final portion of the anterior arthroscopy. The capsulectomy is performed with use of a combination of a full-radius shaver and an up-cutting resector until the muscular fibers of the brachialis are identified. If there is difficulty identifying the capsular layer on the lateral aspect of the elbow, a lateral capsulotomy is performed as an open procedure after the completion of the arthroscopic procedure. The suspended supine position allows for the arm to be easily placed on an armboard, and the proximal lateral portal can be incorporated into an incision exposing the lateral aspect of the elbow.
The posterior compartment is addressed in a similar fashion. Initially, soft tissue is removed from the olecranon fossa and the posterior compartment with use of a full-radius shaver that is placed through the transtricipital portal. Care must be taken when addressing the medial gutter because of the subcapsular position of the ulnar nerve. Once adequate visualization is established, impinging osteophytes from the olecranon are removed with use of a motorized burr. Occasionally, osteophytes on the olecranon fossa may be removed as well. Prior to the completion of the procedure, the arm is taken through a gentle range of motion to release any residual adhesions.
INDICATIONS:
- Capsular release, assessment and treatment of osteochondral defects, synovectomy, removal of loose bodies, excision of olecranon osteophytes, and plica debridement
CONTRAINDICATIONS:
- Any congenital or iatrogenic alteration in the elbow anatomy
- Infection along the portal track sites of insertion
- Previous ulnar nerve transposition (Fig. 10)
- When adequate joint distension is difficult (e.g., ankylosed joint)
PITFALLS:
- The portals are in close proximity to the neurovascular structures surrounding the elbow. It is crucial to have a thorough understanding of the anatomic structures around the elbow and for the portals to be placed precisely.
- There is an increased complication rate in patients with arthrofibrosis.
- There is limited intra-articular working space in patients with arthrofibrosis.
- In patients with posttraumatic elbow contractures, extracapsular heterotopic ossification cannot be addressed.
- There is limited utility for patients who have previously undergone a surgical procedure on the lateral aspect of the elbow because of the possible capsular adherence of the radial nerve or one of its branches.
- It is important to initiate postoperative physical therapy immediately to avoid loss of motion.
AUTHOR UPDATE:
There have been no substantial changes in how we perform arthroscopic capsular release since the time of publication of the original case report. However, we maintain our recommendation of proceeding with caution to the point of avoiding arthroscopic capsular release in a patient who has undergone a previous open elbow procedure involving transposition of the ulnar nerve.