Elbow Arthroscopy (Cadaver)

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.

Questions to Ask While Conducting the History:¹

• 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 medial collateral ligament (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?

Tips for Conducting the Physical Exam:¹

• 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.When evaluating elbow motion, the examiner should observe for any crepitus, pain, or mechanical block symptoms, which could indicate cartilage irregularities or loose bodies. If the elbow has restricted motion in flexion or extension, a soft end point might suggest effusion, soft-tissue swelling, or capsular tightness. Conversely, a firm end point could indicate an osteophyte or loose body causing a mechanical block. Pain at the end point of flexion and extension, particularly localized to the medial olecranon, may be indicative of degenerative changes associated with chronic valgus extension overload and posteromedial impingement.⁶
• Assess instability at 0 and 30 degrees of flexion.
  • At 30 degrees of flexion, 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. Patients 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 a sensation that the elbow is about to dislocate. With flexion, the radius and ulna should reduce with a clunk onto the humerus.
  • Milking Maneuver is used to assess the integrity of the anterior bundle of the MCL. During this test, the patient’s elbow is flexed beyond 90 degrees, and the examiner pulls on the patient’s thumb while the forearm is supinated and the shoulder is forward-flexed. A positive test is indicated by a feeling of apprehension, instability, and medial elbow pain.⁶
  • The moving valgus stress test detects ulnar collateral ligament (UCL) tears. During this test, the patient’s shoulder is abducted to 90 degrees, and the elbow is maximally flexed while applying a modest valgus stress. The elbow is then quickly extended to 30 degrees while maintaining the valgus stress. A positive test is indicated by pain experienced between 120 and 70 degrees of elbow flexion, which correlates with the late cocking and early acceleration phases of throwing.⁶
  • Valgus Stress Test. This test evaluates the MCL by applying a valgus force to the elbow flexed at 20–30 degrees. A positive result is indicated by pain or increased laxity compared to the opposite side.⁶
  • Varus Stress Test. The varus stress test assesses the lateral collateral ligament (LCL) by applying a varus force to the elbow flexed at 20–30 degrees. Pain or increased laxity signifies a positive test.⁶
  • Posterolateral Rotary Drawer Test. This test assesses posterolateral rotatory instability. Elbow is positioned in approximately 40 degrees of flexion. Then anterior to posterior force applied to the lateral aspect of proximal radius and ulna. This maneuver attempts to translate the forearm away from the humerus on the lateral side, pivoting around the intact medial ligaments. Subluxation or apprehension indicates a positive result.⁶

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 While MRI is excellent for initial diagnosis, it may produce false positives or negatives, particularly in complex cases. Arthroscopy, although invasive, is considered the gold standard for diagnosing intra-articular pathologies due to its high sensitivity and specificity. It can resolve these ambiguities by providing a direct view of the joint. However, it carries surgical risks and is more costly. In clinical practice, the decision to use MRI, arthroscopy, or both depends on the specific case. MRI is often used as a screening tool to avoid unnecessary surgeries. When MRI findings are inconclusive or when therapeutic intervention is anticipated, arthroscopy becomes indispensable.

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.

• 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.

Diagnostic elbow arthroscopy is a way to fully evaluate the elbow joint with minimal surgical exposure. It is particularly useful in evaluating trauma to the elbow that has resulted in ligament tears, the joint capsule, the synovium, loose bodies, adhesions and cartilage lesions. 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.