The ulnohumeral arthroplasty: technical tips for safely managing the brachial artery

Abstract

One surgical option to manage idiopathic osteoarthritis of the elbow is an ulnohumeral arthroplasty. A potential complication to avoid during this procedure is inadvertent over penetration of the anterior cortex of the humerus. If this occurs, injury to the median nerve and brachial artery is possible as these structures may lie within 7 mm of the anterior humerus. This surgical technique describes technical tips in regards to patient positioning and specific instrument usage that serve to diminish the risk of this catastrophic complication occurring by allowing these critical neurovascular structures to fall away from the anterior humerus.

Osteoarthritis of the elbow originates from idiopathic disease or as a consequence of elbow trauma. True idiopathic primary osteoarthritis of the elbow is an uncommon disorder of predominantly middle-aged men.⁷ It is characterized by osteophyte formation at the tip of the coronoid and olecranon, and relative sparing of the ulnohumeral joint space. As a result of olecranon fossa osteophytes, patients typically present with pain at the extremes of motion, while remaining asymptomatic in the midrange of motion. This progressive accumulation of bone in the fossa leads to a gradual reduction in the overall arc of motion and potentially increased pain.

Surgical solutions to address this pathology are diverse and range from arthroscopic to open debridement, interposition arthroplasty, ulnohumeral arthroplasty (UHA), and finally total elbow arthroplasty.³ Discussion of all the surgical options and their indications are beyond the scope of this technique article. Instead, we will focus on a technique modification to UHA. This procedure was an innovative technique that exploits a humeral foraminotomy through a posterior approach and was first described in 1978 by Kashiwagi.⁶ Trephination of the distal humerus at the olecranon fossa permits access to the anterior joint and the tip of the coronoid. By excising the ossified olecranon fossa, as well as anterior and posterior osteophytes, a more normal arc of motion can be restored without impingement, thereby alleviating pain at terminal flexion and extension.

Reported complications of UHA include heterotopic ossification² and postoperative neuropathy of the ulnar and radial nerves.¹ While there have been no reports of iatrogenic brachial artery injury during UHA, given the direction of reaming and the proximity of the artery to the anterior wall of the humerus, a cautious approach to over-penetration with the circular reamer must be taken. Despite the potential for this catastrophic complication, until recently there has been limited objective guidance to minimize the risk of arterial injury. Our reported technique takes into account these data and demonstrates a novel positioning method of elbow flexion and shoulder external rotation to minimize the risk of this potentially devastating complication.

Surgical technique

Relevant anatomy

The most relevant anatomy for this procedure is the proximity of the brachial artery to the anterior wall of the humerus and how this is impacted by elbow positioning. In a cadaveric study, using fluoroscopy and barium in the brachial artery, Enad and Douglas⁴ demonstrated statistically significant variation in the distance of the brachial artery to the anterior wall of the humerus, dependent on the degree of flexion of the elbow and whether a bump or bolster is used (Fig. 1). In that cadaveric study the distance varied from as little as 7.0 mm up to 22.9 mm depending on the degree of elbow flexion. The distance was minimized with elbow extension and with the placement of a bump or bolster in the antecubital fossa. Based on these data, our surgical technique emphasizes elbow and shoulder position. Namely, we ream in 90 degrees of flexion, without a padded bolster encroaching on the antecubital fossa, thereby maximizing the distance between the neurovascular structures and the breaching trephine, resultantly increasing the safety of this procedure.

Figure 1.

Note the proximity of the barium enhanced brachial artery to the anterior humerus depending on elbow flexion (a) and whether a bolster is present or not (b).

Indications/Contraindications

Patients presenting with elbow pain and reduced range of motion should be evaluated in the standard fashion. A thorough history should be obtained focusing on remote and recent traumatic events and any previous surgical procedures performed on the elbow. The elbow joint should then be inspected for any abnormal angulation and palpated for any swelling or bony prominences. Active and passive elbow flexion and extension, as well as forearm pronation and supination, should be assessed. Range of motion should be documented, as well as the determination of pain generated at the end of the arcs of motion. It is also important to assess for other pain generators around the elbow including medial and lateral epicondylitis, as well as compressive neuropathies.

Standard anteroposterior and lateral radiographs of the elbow should be obtained to assess the ulnohumeral and radiocapitellar joints, as well as to determine if loose bodies are present and if there are osteophytes on the coronoid and/or olecranon (Fig. 2). Additional radiographic views such as the Greenspan view and internal/external oblique views can be obtained for a more comprehensive assessment. Finally, in some instances, advanced imaging by computed tomography can be obtained to obtain a complete assessment of the articulation.

Figure 2.

Preoperative anteroposterior (a) and lateral (b) radiographs of the left elbow, which demonstrate osteophytes and narrowing of the ulnohumeral joint space.

Once the diagnosis of ulnohumeral osteoarthritis is made, initial nonoperative treatment to manage the patient’s symptoms should be tried, especially if the loss of motion is less than 15°. This can include activity modification, physical therapy to work on range of motion, oral, nonopioid analgesics, and corticosteroid injections. If these nonoperative measures fail to provide the patient with significant enough relief and the patient’s pain and lack of range of motion are interfering with work or other physical activities, then surgical management can be discussed. Multiple surgical techniques exist including arthroscopic debridement, open debridement, UHA, distraction interposition arthroplasty, and for severe cases, total elbow arthroplasty.³ Specific indications for a UHA include moderate pain at the end points of motion and age less than 60 years.

Setup

General anesthesia or monitored anesthesia care with a regional block can be used for anesthesia. The patient is then placed on a bean bag into the lateral decubitus position with an axillary roll. All bony prominences are well padded with the unaffected extremity placed on an arm board in a relaxed semiflexed position. The operative extremity is placed over a well-padded T-shaped extremity holder (Fig. 3). The patient is then brought to the edge of the operative table and secured with the bean bag, table straps, and silk tape. The C-arm is placed parallel to the OR table and comes in from the head of the bed. Fluoroscopic images are obtained preoperatively to ensure visualization of the elbow in both the coronal and sagittal planes. The patient is sterilely prepped and draped, and administered preoperative IV antibiotics. A sterile tourniquet is then applied as proximally as possible and inflated to 250 mm Hg.

Figure 3.

The patient positioned in the right lateral decubitus position with the operative arm suspended over a padded T-bar.

Exposure

Access to the triceps tendon is obtained through a posterior midline incision. The tendon is split longitudinally at the midpoint of the olecranon and lengthened proximally until the full extent of the olecranon fossa can be visualized (Fig. 4). A posterior capsulectomy is then performed, and any loose bodies encountered are removed. Next, olecranon osteophytes are carefully excised with an osteotome, making sure to alter the angle of the osteotome both medially and laterally to avoid gouging the trochlea with a straight-in approach.

Figure 4.

A triceps splitting approach is used to expose the olecranon fossa.

Reconstruction

After olecranon osteophytes are removed, the fossa is sized with the sequential circular dowels, making sure not to encroach on the bone of the medial and lateral columns or the trochlea (Fig. 5). Then, the reamer that provides the best fit is centered on the olecranon fossa and directed along the curve of the trochlea. The surgeon needs to keep in mind the anterior rotation of the trochlea because if this is not mirrored, then the arricular surface of the trochlea could be penetrated. A footprint of the reamer is initiated (Fig. 6), and then a 2.0-mm drill bit is passed bicortically at the perimeter of the footprint in all four quadrants. A depth gauge is used to measure the thickness of the bone to be reamed (Fig. 7). A calibrated circular dowel is then used, providing feedback as to the depth of penetration.

Figure 5.

The olecranon fossa is sized with a calibrated circular dowel.

Figure 6.

The circular footprint is created by the calibrated dowel.

Figure 7.

The perimeter of the circular footprint is drilled (a) and measured (b) for thickness.

Novel positioning

As the reamer approaches the depth that was previously measured, the elbow is placed in 90 degrees of flexion and the shoulder is externally rotated, pointing the hand toward the head of the table (Fig. 8). This position is key, as it translates the neurovascular structures as far anterior as possible, thereby reducing the chance for neurovascular injury. This position also eases the reaming of the fossa in a caudad to cephalad direction. Once this position is maintained, the anterior cortex is breached, and the core is removed providing access to the anterior aspect of the elbow joint. Loose bodies are removed anteriorly, and then, the elbow is flexed beyond 90 degrees bringing the coronoid into view through the foraminectomy. Instead of an osteotome, a Kerrison punch is used in an inverted position. It is inserted through the foramen and placed over the tip of any coronoid spurs to facilitate resection (Fig. 9).

Figure 8.

The shoulder is rotated 90 degrees externally to complete the reaming of the olecranon fossa.

Figure 9.

A Kerrison punch assists in removing the coronoid and widening the foraminotomy.

Closure

Bone wax and thrombin-soaked gel foam are used to minimize hematoma formation within the foramen. Closure is performed in a standard, layered, fashion. The triceps split is closed with figure-of-eight stitches using a permanent, braided suture. The deep dermis and skin are then closed based on the surgeon’s preference.

Rehabilitation

The patient is then placed into a soft dressing with range of motion encouraged. Sutures, if present, can be removed at 10 to 14 days postoperatively. Referral to occupational therapy is not required but can be considered for patients who are not progressing with their range of motion.

Expected outcomes

Since the initial description of the UHA in 1978, there have been multiple reports of successful treatment of idiopathic primary osteoarthritis of the elbow.^1,5,8,10,12 The literature is replete with comprehensive descriptions of the ulnohumeral arthroplasty, but patient and elbow positioning, as well as the surgical approach to the posterior joint, have varied. Stanley et al describe placing the patient in the lateral decubitus position with the elbow supported over a bolster and the forearm hanging freely.¹¹ Morrey⁹ prefers the patient in the supine position with the arm across the chest and the elbow over a bolster.

Access to the posterior joint was originally described in a triceps splitting manner⁶ but can also be accomplished by elevating a portion of the triceps off of the tip of the olecranon.⁹

Based on our experience with the UHA procedure and our anatomic investigations in the laboratory, we recommend (1) placing the patient in the lateral decubitus position, (2) applying the tourniquet as proximal as possible, (3) suspending the elbow over a padded T-bar or bolster that is kept free of the antecubital fossa, and (4) executing the reaming with the elbow flexed to 90 degrees while the shoulder is externally rotated (Fig. 8). Effectively, this position eliminates the compressive effect of the bolster or T-bar in the antecubital fossa, maximizes the distance of the brachial artery to the anterior humerus, and affords an excellent fluoroscopic lateral view of the elbow.

We prefer the triceps splitting approach for its simplicity, and more importantly, for the exposure of the coronoid osteophyte through the humeral foraminectomy. The coronoid can only be visualized with the elbow in flexion, and this can be difficult when the triceps has been reflected especially in the context of a bulky arm or a muscular individual. The Kerrison punch also serves as a safe alternative to the osteotome for removing the coronoid osteophyte, as any inadvertent plunging of the osteotome could result in injury to the anterior neurovascular structures.

To avoid the risk of overzealous reaming, one should consider using the trephine to create an initial “footprint”. Drilling through the anterior cortex in each quadrant along the footprint, and then measuring with a depth gauge, defines the thickness of the olecranon fossa. Calibrated reamers, dowels with an adjustable stop, or marking a noncalibrated trephine are prudent measures that provide the surgeon with a visual cue as to the location of the far cortex.

Complications

The most concerning postoperative complication, which spurred the creation of this technique, is injury to the neurovascular structures that lie anterior to the humerus, including the brachial artery. Beyond that, more typical complications can include heterotopic ossification, nerve palsies to the ulnar and radial nerves, and formation of a hematoma from the trephination. Heterotopic ossification prophylaxis methods have varied historically, including irradiation and nonsteroidal anti-inflammatory medications. Irradiation has been shown to not be a good choice for fracture work secondary to increased non-unions rates.¹¹ Evidence for and against nonsteroidal anti-inflammatory medications is more limited and we prescribe Indomethacin 25 mg three times a day for one month. Precise dissection and placement of retractors without excess force are key to preventing nerve palsies. Finally, hematoma can be prevented by considering the placement of a drain, as well as the application of bone wax and thrombin-soaked gel foam to the bleeding bony surface from the trephination.

Conclusion

During UHA, surgeons must be cognizant of the nearby anterior anatomy when reaming the olecranon fossa, as critical structures including the median nerve and brachial artery lie within 7 mm of the anterior humerus. With thoughtful patient positioning and instrument usage, as described in this technique, the risk of injuring these structures is lessened.

Disclaimers

Funding: No funding was disclosed by the author(s).

Conflicts of interest: The authors, their immediate families, and any research foundations with which they are affiliated have not received any financial payments or other benefits from any commercial entity related to the subject of this article.