Abstract

Elbow arthroscopy is a technically demanding procedure but it is very useful to evaluate the entire elbow joint for pathology with minimal surgical exposure and faster recovery than a traditional arthrotomy. The neurovascular structures of the elbow joint are in close proximity to the joint, thus there is a risk of injury to these structures, so care must be taken to fully understand elbow anatomy and to be prepared for aberrations. Elbow arthroscopy can be used diagnostically, as in this video article, or to surgically treat a variety of conditions including ligamentous tears, loose bodies, capsular stiffness, osteochondritis dissecans of the elbow, osteophyte debridement, and lateral epicondylitis. A patient with a previous ulnar nerve transposition is a relative contraindication to elbow arthroscopy, as there is a high risk of injury to the ulnar nerve during portal placement.

Case Overview

Questions to Ask while Conducting the History¹:

Is there a history of repeated elbow dislocations?
Is there elbow instability? What is the timing?
Is there pain with range of motion?
Is there complete range of motion?
What articulation is involved? It can be the hinge joint or the proximal radioulnar joint.
Was there predisposing trauma?
Has there been previous elbow trauma or surgery?
Does the elbow displace? In what direction?
- Posterolateral rotatory displacement is the most common direction.
- Anterior displacement may be seen with olecranon fractures.
- Valgus instability may be seen with post-traumatic rupture of the MCL or radial head fractures, it may also be seen in athletes with repetitive stress and overload that diminishes or ruptures the anterior band of the MCL.
Varus instability may be seen with LCL complex disruption.
- What is the degree of displacement?
- There can be posterolateral rotatory subluxation with pivot-shift testing (Stage 1)
- There can be incomplete dislocation with the coronoid perched under the trochlea (Stage 2)
- There can be complete dislocation with the coronoid behind the humerus (Stage 3)
Is there recurrent, clicking, snapping, clunking, or locking of the elbow?

Physical Exam

Tips for Conducting the Physical Exam¹:

Visually examine for gross deformity, skin lesions, erythema, or effusion.
Palpate the humerus, elbow joint, radius, and ulna. Looking for tenderness indicative of occult fracture.
Observe and document Elbow range of motion. Observe for any mechanical block to motion or painful range of motion. Assess instability at 0 and 30 degrees of flexion.
- At 30 degrees of flexion, medial collateral ligament (MCL) complex is primary stabilizer. Instability only at 30 degrees indicates MCL pathology.
- In full extension other bony and soft tissue restraints exist. Instability here indicates more extensive injury, with possible anterior and posterior capsule involvement.
- Observe Elbow supination and pronation.
Special tests:
- Lateral pivot-shift apprehension test. Patient supine with arm overhead, forearm supinated, hold distal to elbow and near the wrist and apply valgus and compressive forces while flexing. This will recreate symptoms and cause sensation that elbow is about to dislocate. With flexion, the radius and ulna should reduce with a clunk onto the humerus.

Imaging¹

Imaging should include AP and lateral views of the elbow to assess for fracture or visible loose bodies. A lateral stress view, preferably valgus and varus stress under fluoroscopy, should be taken to assess for displacement. Joint space widening >2 mm indicates instability. MRI of the elbow can provide good visualization of the MCL. CT arthrography can help to evaluate for tears on the undersurface of the MCL.²

Natural History³

Elbow stability is derived from the combination of static forces from bony articulations, capsule, and ligaments with dynamic forces from muscles and tendons. MCL complex is composed of anterior (AMCL) and posterior (PMCL) bundles of MCL and the transverse oblique bundle. The AMCL is taut throughout elbow range of motion and provides at least 70% of valgus stability. Lateral collateral ligament (LCL) complex is composed of annular ligament, radial collateral ligament (RCL), lateral ulnar collateral ligament (LUCL), and accessory lateral collateral ligament. The LUCL is the most important stabilizer against posterolateral instability. Chronic valgus instability is usually due to overuse by throwing athletes or those performing overhead activities. Repetitive stress due to frequent muscle use or extrinsic loading applies valgus force to the MCL over prolonged periods without time for adequate healing. This results in the valgus-extension overload syndrome defined by diminution of the MCL, compression of the radiocapitellar and posteromedial ulnohumeral joints. Subsequent olecranon impingement can lead to inflammation and osteophytes that can fracture and form loose bodies. Pain and flexion contracture may result. Acute MCL rupture may occur with elbow dislocation and, without repetitive stress, generally heals adequately and does not lead to valgus elbow instability. Loose bodies may also result from osteochondritis dissecans of the bony elbow structures.

Options for Treatment^4,5

Elbow arthroscopy may be used for diagnostic and therapeutic purposes as an alternative to the more invasive surgical arthrotomy. The technique may be used for diagnosis of inflammatory, degenerative, or traumatic arthritis, loose bodies, acute evaluation of elbow fractures, and evaluation of elbow pain of unclear etiology. The technique may be used for therapeutic extraction of loose bodies, debridement of capitellar osteochondritis dissecans, synovectomy for treatment of rheumatoid arthritis, tennis elbow release, radial head excision, and lysis of adhesions and osteophyte extraction in arthritic conditions, capsulectomy, elbow instability and elbow ligament reconstruction, and arthroscopic reduction of elbow fractures.

Structures to Evaluate

Proximal Anterolateral Portal: useful for evaluation of medial elbow joint, radiocapitellar joint, and the lateral recess. Take care to avoid injury to the radial nerve.
Anterolateral Portal: useful for evaluation of the distal humerus, trochlear ridges, and coronoid process. You may be able to evaluate the radial head by angling the arthroscope. Take care to avoid injury to the radial nerve.
Proximal Anteromedial (Superomedial) Portal: useful for evaluation of the anterior compartment, the capitellum and radial head. May also be possible to evaluate the annular ligament as it courses over the radial neck. Trochlear, coronoid process, and coronoid fossa may also be observed via this portal. Take care to avoid injury to the ulnar nerve.
Anteromedial Portal: useful for examination of lateral elbow joint and proximal capsular insertion. Take care to avoid injury to the medial antebrachial cutaneous nerve.
Posterolateral Portal: useful for evaluation of the olecranon fossa, olecranon process, and posterior trochlea. Take care to avoid injury to the medial and posterior antebrachial cutaneous nerves.
Accessory Posterolateral Portals: useful for evaluation of the posterolateral recess.
Direct Lateral (Soft-Spot) Portal: useful for joint distention and evaluation of the inferior capitellum and radioulnar joint. Take care to avoid injury to the posterior antebrachial cutaneous nerve.

Rationale for this Procedure

Diagnostic elbow arthroscopy is a way to fully evaluate the elbow joint with minimal surgical exposure. It is particular useful in evaluating trauma to the elbow that has resulted in ligamental tears, the joint capsule, the synovium, loose bodies, adhesions and cartilage lesion. Additionally, many therapeutic interventions can be conducted through arthroscopic portals as noted above.

Special Considerations and contraindications to elbow arthroscopy⁵

Contraindications include distorted anatomy that would make portal placement difficult or dangerous. Care should always be taken to avoid the ulnar nerve, medial nerve, radial nerve, medial and posterior antebrachial cutaneous nerves, and brachial artery during portal placement by thorough evaluation of bony landmarks prior to portal placement. Elbow structures can also be damaged by overly aggressive distention or instrument manipulation. Previous transposition of the ulnar nerve is not an absolute contraindication, but should be considered carefully before proceeding with elbow arthroscopy, as this can increase the risk of nerve injury during portal placement.