Management of a failed shoulder arthroplasty can be a perplexing problem for both the patient and the surgeon. Unlike primary shoulder arthroplasty, revision reconstruction is far less predictable and carries a significantly higher risk of complications.¹⁰,¹³,²⁰,⁶³,⁶⁷ There are many aspects to consider when treating a patient with a failed arthroplasty. First, an evaluation must be done in a systematic fashion. Elucidating a clear etiology for failure is critical and will dictate the strategy for revision surgery. Once revision surgery is undertaken, there are numerous pitfalls the surgeon must avoid. Surgical exposure is often very difficult and can lead to intraoperative complications. Implant removal can also be frustrating and time-consuming. Management of bone and soft tissue defects can be very challenging and leave few options for the surgeon. Postoperatively, close monitoring is required as these patients are typically elderly and are prone to hospital-related complications.

In the past, revision shoulder arthroplasty was a relatively uncommon procedure performed by a small subset of shoulder surgeons. Recently, however, shoulder arthroplasty has become much more routine and is performed by a broader range of orthopedic surgeons. A recent epidemiological survey found that upper extremity arthroplasty volume was increasing as fast or faster than hip and knee arthroplasty.¹⁹ They also found that the revision burden for shoulder arthroplasty will substantially increase over the next 5 years. Therefore, it is important for the surgeon to have a complete understanding of the concepts of revision shoulder arthroplasty. The goal of this chapter is to discuss all the critical aspects of revision shoulder arthroplasty, with particular focus on the techniques of exposure, revision implantation, and management of bone and soft tissue loss.

Successful management of a failed shoulder arthroplasty begins with a thorough evaluation. Only after the patient has been interviewed and examined, a diagnosis can be made. Often,
the radiographic findings do not convey the entire clinical picture and targeted interview questions can be very helpful in deciphering the underlying mode of failure. A complete patient evaluation entails patient interview, physical examination, imaging studies, and laboratory values.

Both the patient and surgeon need to be prepared for surgery. From the patient perspective, revision surgery can cause a significant strain on the body. The patient’s overall medical condition should be carefully assessed and medical optimization is crucial in preventing postoperative complications. All anti-coagulant medications should be held for approximately 1 week prior to surgery and access to matched blood products intraoperatively is recommended. Body positioning should be carefully considered, especially in patients with a history of stroke as full beach-chair position can lead to a decrease in cerebral perfusion.²¹,⁵³ Revision surgery can be unpredictable with regard to estimated blood loss and procedure length. Therefore, Foley catheter placement is recommended and possibly arterial line placement. In patients with a cardiac history, postoperative telemetry monitoring and cardiac markers should be considered.

From the surgeon’s perspective, preoperative planning and anticipating pitfalls is crucial for a successful outcome. Preoperative imaging must be closely investigated prior to surgery. Full-length humeral plain films and advanced imaging (CT or MRI) are sometimes necessary. Specific attention should be paid to the condition of the rotator cuff and constrained implant instrumentation should be available if the integrity of the rotator cuff or tuberosities is in question. Also, bone deficiencies need to be identified preoperatively. In cases of severe bone loss, allograft material must be readily available and occasionally iliac rest bone graft is preferable for glenoid bone loss. With regard to revision equipment, a variety of deep shoulder retractors is helpful in the revision setting (Fig. 24-4). A plan for implant removal is also necessary. Humeral stem removal can be very difficult, especially with well-fixed ingrowth stems. An oscillating saw, cerclage cables, and implant-specific extraction tools should all be available in the operating room. Also, power cement extraction tools and small, flexible osteotomes are necessary for removal of
well-fixed cemented stems. Long humeral stems are occasionally needed to bypass a periprosthetic fracture or area of segmental bone loss. Diaphyseal diameter should be measured and occasionally humeral stems have to be shortened with a cutting wheel-saw due to narrowing of the intramedullary canal. Custom implants are sometimes necessary and adequate time should be allotted for implant manufacturing. Ultimately, a well-executed revision arthroplasty is the result of a thorough and thoughtful preoperative plan.

Revision shoulder arthroplasty is typically performed under both general and regional anesthesia. Placement of an interscalene nerve block preoperatively has been shown to decrease the amount of narcotics administered intraoperatively and postoperatively and is associated with a low complication rate.⁷ The patient is positioned in the beach-chair position with the cervical spine immobilized in neutral and all bony prominences are well padded. The patient is brought to the edge of the table and the medial border of the scapula should be incorporated into the sterile field, especially if a posterior exposure is anticipated. It is important to ensure that the operative arm can be fully adducted as this will be necessary during humeral exposure. The sterile field is made very wide to allow for extensile exposure if necessary. Prior to beginning the procedure, a final assessment is made to ensure all necessary equipment, blood products, and implants are available.

In the revision setting, there can be multiple previous surgical incisions. Typically, there is a scar from a previous deltopectoral approach that can be incorporated into the surgical incision. If however, there are no incisions on the anterior aspect of the shoulder or it is felt that they are too far from the typical incision, a new incision can be made. The shoulder girdle has excellent vascularity and wound healing complications in this area are rare. We prefer to leave at least a 4 cm bridge between parallel incisions if possible. The ideal skin incision for revision arthroplasty is from 2 cm proximal to the coracoid tip extending distally to the deltoid insertion. This will allow for extension of the exposure to an anterolateral approach to the humerus if necessary. We prefer to keep the incision well away from the axilla for contamination concerns.

The deltopectoral approach is used for virtually all revision arthroplasty exposures. The anterosuperior approach has also been described for the difficult revision exposure, where the anterior deltoid is taken off the acromion and clavicle. Foruria et al. reported the utilization of this approach in nearly 40% of revision arthroplasty cases.²⁴ They found no complications related to deltoid detachment. We seldom find this approach necessary, but if the anterior deltoid appears to be failing during exposure this approach may be beneficial. With
the deltopectoral approach, the interval is found most reliably by identifying the area devoid of muscle attachment on the anterior aspect of the clavicle at the proximal extent of the incision. This typically appears as a triangle as the deltoid and pectoral muscles converge distally (Fig. 24-5). The cephalic vein can be found in this interval. The coracoid process is helpful in localizing this area, especially in the revision setting. The deltoid typically drapes medially over the coracoid for approximately 2 cm. Once the interval is identified, the cephalic vein is dissected and retracted laterally with the deltoid. In an anatomical study with retrograde latex injection of the cephalic vein, Radkowski et al. found more lateral branches of the vein and recommended lateral retraction during the deltopectoral approach.⁵⁹ Sometimes there is significant scarring in this area and frequently the vein has been injured during previous surgical exposures. In these cases, we prefer to identify the interval proximally at the clavicular origin of these two muscles. The pectoralis insertion is then released. The width of the pectoral insertion has been shown to be 5.7 cm (4.8 to 6.5 cm) and the superior 3 cm can be released for improved exposure.³⁹ If pectoral muscle transfer is a consideration, care should be taken to preserve as much tendon length as possible. The subdeltoid space is then developed. This is considerably more difficult in the revision setting and frequently requires meticulous dissection through extensive scar tissue. The deltoid is usually adhered to the underlying subdeltoid bursal tissue and bone. Care should be taken during this step to avoid injury to the posterior humeral circumflex artery and axillary nerve as they course around the arm on the undersurface of the deltoid. The subdeltoid space is most easily found distally and dissection is carried proximally (Fig. 24-6). Once the subdeltoid space has been developed, it is extended proximally to the subacromial space. Care should be taken to avoid injury to the underlying rotator cuff, if present. The importance of releasing the subacromial and subdeltoid space cannot be overstated; the surgeon should be able to easily pass a finger from the subdeltoid to subacromial space without intervening scar tissue. This exposure will allow for later deltoid retractor placement and humeral exposure.

The deep exposure begins with releasing the clavipectoral fascia, and a portion of the coracoacromial ligament can be released for additional exposure. The conjoint tendon is then released and retracted medially. The conjoint tendon can be scarred and adhered in a more lateral position and the lateral extent of the strap muscles should be clearly identified prior to medial retraction. Also, the conjoint tendon can have dense scarring to the underlying subscapularis. Identifying the proper plane of dissection can be difficult, but is crucial for axillary nerve localization (Fig. 24-7). The subscapularis can now be clearly visualized (if present). The anterior circumflex vessels, which course on the lower border of the subscapularis can be coagulated. The axillary nerve must now be localized. It can be found in the plane between the conjoint tendon and subscapularis at the lower border of the subscapularis. In the revision setting, this area can have scar tissue that prevents easy palpation of the nerve. Patience and careful dissection should be used to clearly palpate the nerve as its location will need to be known prior to capsular release and glenoid exposure. Identification of the biceps tendon (if intact) and bicipital groove will help identify the greater and lesser tuberosities and the rotator interval. The subscapularis is then released either by tenotomy or lesser
tuberosity osteotomy. In most revision cases, a lesser tuberosity osteotomy is not feasible and a tenotomy is performed. In order to dislocate the humerus and to gain adequate exposure of the glenoid, a capsular release directly off the humerus is performed. The arm is brought into progressive adduction, external rotation, and flexion to visualize the capsular insertion on the medial humeral calcar. The release should be taken down to the level of the latissimus tendon insertion. Care should be taken to stay directly on bone during this release as the axillary nerve can be scarred in close proximity to the capsule. If necessary, the release can be taken posteriorly until the teres minor insertion. The proximal humerus can now be dislocated anteriorly and special retractors are used to maintain exposure (Fig. 24-4C). Particular care should be taken not to aggressively externally rotate the arm before a proper release has been performed as this can lead to a spiral periprosthetic humeral fracture in these osteoporotic patients. Once the humerus has been dislocated and adequate exposure has been established, attention can then be turned to humeral component removal.