Extended deltopectoral approach for revision total elbow arthroplasty requiring humeral allograft-prosthetic composites in patients with severely compromised proximal humerus bone stock

Abstract

Background

Severe humeral bone loss in the setting of failed total elbow arthroplasty (TEA) poses a particularly challenging reconstructive problem. The objective of this study was to review the rationale, indications, contraindications, and detailed surgical technique for using an extended anterior deltopectoral approach to perform a revision TEA when substantially long allografts are required in the presence of severely compromised proximal humerus bone stock.

Methods

The authors developed this exposure and reconstructive strategy for failed elbow arthroplasties where the remaining segment of proximal humerus is extremely short, which makes adequate plate fixation of an allograft-prosthetic composite (APC) to the native bone extremely challenging. From an anterior deltopectoral approach, it is possible to use dedicated long, precontoured proximal humerus locking plates to maximize fixation in any remaining proximal humerus. This exposure still makes it possible to provide adequate access to the coupling mechanism of the humeral and ulnar components for implantation of a linked elbow arthroplasty. This exposure also allows for adequate judgment of humeral length and rotation.

Pitfalls and Challenges

Crucial steps in the surgery include extending the dissection past the elbow flexion crease such that one can obtain circumferential exposure of the distal humerus. It is also important to couple the humeral and ulnar components prior to committing to the length of the APC. Special attention must be paid to gauge appropriate APC rotation and length for proper soft tissue tension. When performing fixation of the proximal humeral plate, screw purchase must be maximized in both the remaining native proximal humerus and the APC. Compression across the allograft-host interface is paramount for healing to occur.

Conclusion

An extended anterior deltopectoral approach to perform a revision TEA when very long APCs are required is a viable option to restore humeral bone stock and regain humeral stem fixation in the setting of failed TEA with extensive humeral bone loss.

Total elbow arthroplasty (TEA) is used to treat a variety of conditions, including rheumatoid arthritis, post-traumatic arthritis, acute fractures, osteoarthritis, and malignancies.^1,4,7,11,18 The rates of TEA in the United States continue to grow at a pace higher than or comparable to that of lower extremity arthroplasty.⁵ The increasing rates of primary TEA raise the concern for increased need for revision TEA and the development of viable techniques for reconstruction in the revision setting.

Failed TEAs may present with a host of problems, including infection, loosening, and extensive bone loss.^15,17 Resection arthroplasty for failed TEA may provide acceptable pain relief but has generally poor functional outcome scores.¹⁹ As such, strategies for reconstruction in the presence of bone loss, such as impaction grafting, allograft strut augmentation, modular segmental (tumor) prostheses, and allograft-prosthetic composites (APCs) are oftentimes required.^6,8,10,12

Extensive humeral bone loss, be it in the setting of failed TEA or tumor resection, poses a challenging problem for limb reconstruction. Modular segmental prostheses (tumor prostheses) are appealing but may be fraught with relatively high rates of humeral loosening.^3,9 Alternatively, APCs, as described in the setting of both revision TEA and revision total shoulder arthroplasty, can be employed.^13,14,16

When very little proximal humerus remains in the setting of a failed TEA and/or when the remaining bone is of poor quality, achieving adequate fixation of a large allograft to the residual proximal humerus is very difficult. This is particularly challenging to perform using a posterior approach: the deltoid and axillary nerve substantially limit proximal exposure unless the posterior deltoid is formally detached from the spine of the scapula or its insertion on the humerus. In addition, there are no plates designed for multiplanar locking-plate fixation of the posterior proximal humerus. Finally, surgical management of the radial nerve is always complicated when the whole length of the humerus needs to be exposed from the elbow to the shoulder. For these reasons, we developed a surgical strategy to perform a revision TEA with a long APC through an extended anterior deltopectoral approach. To our knowledge, this strategy has not been described in the literature. To date, there has been one case report of a humeral stem with an anterior cortical breach that was excised with a mini-open anterior approach but without attempting revision of the TEA or placement of a large humeral APC.²

The objective of this study is to review the rationale, indications, contraindications, and detailed surgical technique for using an extended anterior deltopectoral approach to perform a revision TEA when the magnitude of humeral bone loss leaves a very small segment of the proximal humerus available for plate fixation across the host-graft junction.

Materials and methods

Rationale

Using an extended anterior deltopectoral approach for revision TEA in the setting of severe humeral bone loss offers several advantages. Primarily, it offers extensive exposure proximally, meaning that it can provide adequate exposure even in the most severe cases of humeral bone loss. It also allows for easier placement of commercially available, precontoured, long proximal humeral plates with multiaxial locking screw fixation into the humeral head. With an extensile posterior approach, access to the most proximal aspect of the humeral head is still limited due to the posterior deltoid and axillary nerve. As such, trying to obtain screw purchase into the humeral head in a patient who already has such limited proximal bone stock becomes difficult from a posterior exposure. Finally, management of the radial nerve becomes more cumbersome when using a posterior approach from the elbow to the shoulder, whereas a deltopectoral approach extended into Henry’s brachialis splitting exposure protects the radial nerve substantially more.

A concern with approaching an elbow revision case anteriorly is the potential for difficulties with attempting to unlink/link the humeral and ulnar components. However, we have developed a sequence of steps that allows linking the implant from an anterior approach, and we have been successful in achieving adequate linking with three implants (Stryker Tornier Latitude, Stryker, Kalmazoo, MI, USA; Zimmer-Biomet Coonrad-Morrey, Zimmer Biomet, Warsaw, IN, USA; and DJO Discovery, DJO, Lewisville, TX, USA). This is advantageous from an intraoperative positioning standpoint, where the patient would likely need to be repositioned to access the posterior aspect of the elbow, in addition to the anterior aspect of the humeral shaft.

Alternatives

An alternative to an anterior approach would be to use a posterior approach alone, or a combination of an anterior more limited approach and a posterior approach, with disadvantages as described above. A potential advantage of a posterior approach is easier access to the coupling mechanism of the humeral and ulnar stems, in addition to adequate exposure for ulnar component revision and reconstruction of the extensor mechanism.

An alternative to using a humeral APC would be the implantation of a modular segmental (“tumor”) prosthesis. These prostheses are modular in nature and can be used to restore length, albeit often only in fixed increments due to constrains in the modular segment sizing. The very short remaining proximal humerus in those elbows considered for the exposure and technique described in this article would make it extremely difficult to secure a short, cemented stem for sound fixation of a modular segmental prosthesis.

Indications

The primary indication in our practice for using an anterior approach is when the remaining humeral bone stock is proximal to the deltoid tuberosity or where using a traditional non-locking plate without a specific screw cluster for the humeral head would not provide adequate fixation in the proximal bone.

Indications for revision TEA with a very long humeral APC may include bone resorption and erosion secondary to the loosening of long-stem humeral components, as well as certain periprosthetic fractures. Severe humerus bone loss can also be the result of an extensive resection to eliminate deep periprosthetic infection. Although less common in our practice, a primary TEA with a very long APC may also be required for the surgical management of a humeral malignancy that requires sacrificing the distal humeral articulation and excision of a large segment of the humeral shaft.

Contraindications

Contraindications to the procedure include persistent, uncontrolled deep infection and absence of a minimum amount of proximal humeral bone stock for plate and screw fixation. Additionally, in patients where bone healing is substantially impaired, such as those requiring radiation for malignancy, an APC may be contraindicated and a megaprosthesis may be more suitable. Furthermore, if the surgeon anticipates that the ulnar component may require a complex revision beyond the exchange of a cemented component, a posterior approach may be more appropriate and may need to be employed instead of or in addition to the anterior approach. The need for a concomitant reconstruction of the extensor mechanism (triceps) would be another consideration in favor of an extended posterior approach or a combined approach.

Surgical technique

Exposure

The patient is placed supine with the torso angled approximately 60° cephalad in the “high beach chair” or “barber chair” position. No tourniquet is used given the proximal extent of the planned dissection. The arm is placed on a padded Mayo stand. The incision is marked from just lateral to the coracoid process proximally to mid-anterior proximal forearm distally. It is important to carry the distal dissection across and past the elbow flexion crease to facilitate component uncoupling and recoupling.

The proximal dissection is carried through the standard deltopectoral interval (Fig. 1, A). It is customary in our practice to mobilize the cephalic vein medially. The undersurface of the deltoid is mobilized off the rotator cuff and retracted laterally (Fig. 1, B). It is important to note that in cases of severe humeral bone loss, the insertions of the deltoid and pectoralis major muscles may be compromised. They may also need to be partially detached in order to place the APC. Effort should be made to tag these with sutures to make later identification and repair easier.

Figure 1.

Intraoperative photographs for surgical technique. (A) An extended deltopectoral exposure is performed from lateral to the coracoid process to past the flexion crease of the elbow anteriorly. (B) The proximal dissection is carried down to the humerus via the deltopectoral interval. (C) Distally, the radial nerve is found between the brachialis and the brachioradialis, and a vessel loop is placed around it. (D) The radial nerve is mobilized and the brachialis is split in order to expose the humeral shaft. The dissection is then carried distally to the coupling mechanism of the total elbow arthroplasty (TEA). (E) A whole humerus allograft is prepared and cemented with the humeral component of the TEA on the back table. (F) The allograft-prosthetic composite (APC) is placed into the wound and the TEA components are aligned. (G) The TEA is re-coupled. (H) Traction is applied to the arm, and the length and rotation are assessed. The APC is marked for the site of the osteotomy and then cut. (I) The APC is secured to the remaining native proximal humerus with interfragmentary screws and a long proximal humerus plate.

The dissection is then carried distally, with blunt dissection through the subcutaneous tissues as the elbow is approached, to avoid injury to the posterior cutaneous nerve of the forearm. The interval between the brachialis and brachioradialis is identified and explored to find the radial nerve (Fig. 1, C). The radial nerve is mobilized proximally to the level of the lateral intermuscular septum of the arm and a vessel loop is placed around it to protect it throughout the case (Fig. 1, D).

The brachialis is then split such that approximately one-third of its muscle belly is lateral and two-thirds is medial. The musculocutaneous nerve is not dissected out independently and is instead protected indirectly by leaving it with its soft tissues between the lateral third of the brachialis and the biceps brachii muscle belly. The brachialis split is elongated until the anterior humeral shaft is encountered. The split is then carried proximally to the level of the deltoid insertion. The deltoid is then retracted laterally to expose the subscapularis insertion. Similarly, the brachialis split is carried distally until the anterior capsular attachment of the elbow joint is encountered. At this point, the entirety to the humeral shaft from the glenohumeral joint to the elbow is exposed. The median and ulnar nerves are not specifically dissected out in this approach, to preserve their extrinsic vascularity. These nerves are protected indirectly by performing subperiosteal dissection after the brachialis split that leaves them incased in their respected soft tissues.

Uncoupling of TEA

Distally, dissection is continued by staying on the anterolateral aspect of the humeral shaft, lifting the periosteum and capsule as a sleeve off the distal humerus, thus protecting the neurovascular structures that lay directly anterior and medial to the dissection plane. This subperiosteal dissection is followed medially and posteriorly until the distal humerus is exposed and the coupling mechanism of the TEA is visible. Similarly, dissection is carried laterally and posteriorly, until the distal humerus is completely exposed. Circumferential exposure of the distal humerus is paramount to ensure safe and effective instrumentation. The TEA is then uncoupled, with mechanisms varying based on the manufacturer of the previous arthroplasty in place. Thereafter, the residual distal humerus and humeral stem are removed.

In cases where access to the coupling mechanism is difficult, the humerus can be delivered out of the wound proximally first. In cases of periprosthetic fractures, this can be accomplished relatively easily through the fracture site. Otherwise, the humerus can be osteotomized at or distal to the planned allograft-host interface. Once the proximal humerus is delivered out of the wound, proximal traction is applied such that the humerus pulls the ulna to which it is still linked and delivers the coupling mechanism into the field of view.

Additional bony fragments and debris from osteolysis or previous surgeries are excised as needed. The residual proximal humerus is examined, and old cement and cement restrictors are removed.

Allograft preparation

It is our preference to use an entire humerus allograft, as it provides the maximum amount of flexibility to restore bone stock and create varied allograft-host interfaces. The allograft is prepared on the back table (Fig. 1, E). First, the humeral condyles are resected; although the medial and lateral columns could be retained while preparing the distal portion of the graft, keeping the columns intact will make it more difficult to link the humeral and ulnar components from an anterior approach. The allograft canal is then opened with a bur and sequentially broached until the appropriate size is achieved. It is our preference to place the largest stem size that the allograft will accept, in order to create maximal interference fit and minimize the thickness of the cement mantle. In these elbows with such severe humerus bone loss, it is impractical and typically not possible to bypass the host-graft junction with the humeral stem, even when using an 8-inch off-the-shelf humeral component. A cement restrictor is then placed into the allograft and the humeral stem is cemented in place. Additional cement is placed between the anterior flange of the humeral stem and the anterior surface of the allograft to provide further stability. The anticipated location of the stem tip should be noted so that the plate used for fixation will overlap with at least a portion of the stem.

Re-coupling of TEA

It is important to note that the surgeon should not commit to the length of the humeral APC until the elbow has been rearticulated. This allows for better fine-tuning of the length and soft tissue tension. The ulnar component is essentially telescoped proximally through the soft tissues to deliver the coupling mechanism into the field of view. The humeral component already cemented inside the APC is then secured to the ulnar component according to the manufacturer's guidelines for component linking (Fig. 1, F and G).

Humeral APC orientation and length

Having the correct APC length and orientation, as well as proper soft tissue balancing, are critical aspects of the procedure. After the humeral and ulnar components have been re-coupled, the proximal portion of the allograft is brought into the field. Traction is applied to the arm with the elbow in approximately 90° of flexion. Traction should be avoided with the elbow fully extended because that risks under-tensioning the soft tissues and could potentially lead to hyperextension of the total elbow joint.

The rotation of the arm relative to the proximal humerus and torso must also be judged carefully. We typically place the arm in 30° of external rotation relative to the proximal humeral shaft to approximate native retroversion. Once satisfactory length and rotation have been achieved, a marking pen is used to delineate the site of the osteotomy of the allograft (Fig. 1, H). At this time, it is also determined what type of allograft-host interface would confer the greatest amount of stability to the construct. This can vary from a simple transverse end-to-end type construct to more elaborate constructs involving strut-like extensions or even intussusception, as previously described.¹⁴

Internal fixation

After the allograft has been prepared, it is fixed to the native residual proximal humerus. Typically, provisional fixation is achieved by bringing the desired precontoured long proximal humerus locking plate to the field and clamping it to the lateral aspect of the native humerus and allograft with reduction forceps. (Fig. 1, I). It is important to use a proximal humerus plate, instead of a simple reconstruction plate, to maximize the screw purchase options proximally into the humeral head and to confer the greatest stability to the construct (Fig. 2). If deemed necessary, an additional shorter reconstruction plate can be applied to the anteromedial aspect of the allograft-host junction. Interfragmentary screws may be placed in cases where a strut-like extension is used. It is absolutely critical at this stage to ensure that there is maximal contact and compression of the allograft against the native bone, in order to maximize the potential for osseous union and reduce the incidence of late hardware failure.

Figure 2.

Preoperative and postoperative radiographs of patients who underwent revision total elbow arthroplasty (TEA) with concomitant massive humeral allograft-prosthetic composite (APC) fixed with a long lateral locking humeral plate via the extended deltopectoral approach for either humeral bone loss, loosening, and/or periprosthetic fracture. Preoperative radiographs are labeled “a” and postoperative radiographs are labeled “b”. Arrow () in panel 3b demonstrates bony bridging and complete union across the graft-host interface at 25 months postoperatively.

Additional screws are placed distally through the proximal humerus plate. We believe that maximal screw purchase in the distal segment is critical to confer stability. It can be technically challenging to drill screw tracks around the humeral stem and through the cement mantle. Previously, cerclage cables alone were used to gain distal fixation; however, this does not confer absolute stability and has a relatively high failure rate in APC fixation, such that it led to a moratorium on APCs at our institution for some time^13,14 (Fig. 3). Once maximal screw purchase is achieved, intraoperative fluoroscopy is used to ensure no intra-articular penetration of the proximal humeral screws.

Figure 3.

Radiographs demonstrating a patient who underwent revision total elbow arthroplasty (TEA) and humeral allograft prosthetic composite (APC) via anterior approach and had failure of their construct. (A) and (B) Preoperative anteroposterior (AP) and lateral radiographs demonstrating fracture of the humeral shaft proximal to the long TEA humeral stem through the cement mantle. Intraoperatively, the humeral stem was found to be loose. (C) and (D) Early postoperative radiographs demonstrating revision TEA with APC of the humeral stem and open reduction internal fixation (ORIF) of the fracture with a long lateral humeral plate, augmented with cerclage cables. (E) and (F) Radiographs at the 6-month follow-up demonstrating failure of fixation. We believe this failure occurred due to inadequate cement removal at the allograft-host interface that prevented osseous union. Also, there was inadequate screw fixation into the APC distally and the construct was largely reliant on cerclage cables, which we have since demonstrated has a high failure rate.

Closure

Closure is performed in a systematic manner to recreate a sleeve of soft tissue around the reconstruction. The brachialis split is closed with interrupted absorbable sutures. The pectoralis major and deltoid are reattached using sutures through the plate to appose their respective tendons so that they will heal. Alternatively, a whole humerus graft with soft tissue attachments may be ordered when severe compromise of the deltoid insertion is anticipated. Alternatively, the pectoralis major and deltoid are re-approximated to each other. Standard subcutaneous and skin closure then proceeds. The patient is placed in a shoulder immobilizer with an abduction pillow postoperatively.

Clinical experience

The authors have performed this procedure in 6 elbows. The details of the outcomes regarding these procedures are summarized in Table I. An example of a patient’s postoperative range of motion and incision healing is shown in Figure 4.

Table I.

Summary of radiographic and clinical outcomes of patients undergoing revision TEA with massive humeral APCs via the extended deltopectoral approach.

Variable	Result
Nonunion at graft-host interface	1/6 (16.7%)
Hardware failure	1/6 (16.7%)
Pain score	2.7 (range 1-4)
ROM	−10 to 140 (range −20 to 140)
Satisfied with procedure	80%

APC, allograft-prosthetic composite; ROM, range of motion; TEA, total elbow arthroplasty.

Figure 4.

Clinical pictures of a patient who underwent an extended deltopectoral approach for revision total elbow arthroplasty requiring humeral APC. (A) Postoperative extension. (B) Postoperative flexion. (C) Well healed incision. APC, allograft-prosthetic composite.

Overall, given the challenging nature of this problem, complications in this patient population are expected. Chief among these are concerns for nonunion at the allograft-host interface, which could lead to fatigue failure of the instrumentation. Often, these patients have undergone multiple previous surgeries and the tissue planes are quite scarred, increasing the risk of neurovascular injury. Furthermore, loosening of the stem remains a concern, be it on the humeral or ulnar side. Finally, wound complications and infections are also not uncommon.

Conclusion

Extensive humeral bone loss in the setting of failed TEA poses a significant reconstructive challenge for the treating orthopedic surgeon. APCs are a viable option to restore humeral bone stock and regain robust humeral stem fixation. Performing this surgery through an anterior approach in cases of severely compromised remaining proximal humerus bone stock allows adequate exposure of the proximal segment and permits utilization of a long precontoured proximal humeral plate with maximal multiaxial locking screw purchase in the humeral head, while simultaneously allowing adequate distal exposure for ulno-humeral component coupling and uncoupling.

Crucial steps in the surgery include adequate distal exposure past the elbow flexion crease, circumferential exposure of the distal humerus, not committing to the humeral APC length prior to linking the components, carefully judging APC rotation and length, maximizing screw purchase in the distal fragment without over-reliance on cerclage cables, maximizing screw purchase in the residual proximal humerus, and obtaining compression across the allograft-host interface.

Disclaimers:

Funding: No funding was disclosed by the authors.

Conflicts of interest: The authors, their immediate families, and any research foundation 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.