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Table 5. Advantages and disadvantages of endoprosthesis reconstruction
Advantages Disadvantages
Modularity of prosthesis Proximal Migration (Hemiarthroplasty)
Convertibility of prosthesis Instability
Immediate stability Aseptic Loosening
Early range of motion and functionality Metal-soft tissue attachments
Lower complication rates compared to osteochondral allograft Infection
No need for allograft
Good long-term survivability
Good long-term functional outcomes

Disadvantages [Table 5]: The disadvantages of endoprosthesis reconstruction include increased risk for
dislocation, proximal migration [Figure 3], and infection. Decreased capacity for restoration of soft-
tissue attachments due to the non-biologic metal-soft-tissue interface contributes to the potential for
instability [16,18] . Proximal migration [Figure 3], subluxations, and dislocations are common with this
[18]
reconstruction [19-21] . Ross et al. reported proximal migration, subluxation or dislocations in 16/25
endoprosthetic proximal humeral reconstructions. Endoprosthetic complication rates between 4.5% and
85% have been reported, with the most common complications including proximal migration, subluxation,
[17]
infection, and aseptic loosening .
Outcomes: This reconstruction technique can result in good functional outcomes, as shown in a systemic
[17]
review performed in 2014 . In this systemic review, MSTS functional scores ranged from 61% to 77% over
[17]
[17]
10 studies in 141 patients . Implant survival ranged from 38% to 100% over 17 studies in 341 patients .
[22]
In another case series of 39 patients, Raiss reported 72% survivorship with average three-year follow-up .
Allograft Prosthetic Composite
Reconstruction of the proximal humerus using an allograft prosthetic composite (APC) provides a hybrid
of allograft and prosthetic reconstruction techniques [Figure 5]. The APC was initially designed in hip and
knee surgery to address the problems with resorption, fracture, and cartilage degeneration in osteochondral
allograft reconstructions. This reconstruction option has a hybrid advantage and disadvantage profile
combining some of the advantages and disadvantages of both the all biologic osteochondral allograft and
the endoprosthesis reconstructive options.

Indications: In patients requiring substantial bone and soft-tissue resections, an APC can help decreased
the risk of dislocations and instability associated with an endoprosthesis reconstruction. In situations where
there is tumor involvement of the glenohumeral joint, an extra-articular resection is needed to limit the
risk of local recurrence. If there is pre-existing glenohumeral arthrosis in conjunction with significant soft-
tissue resection, an APC can be a viable reconstruction option. In situations where the rotator cuff has to
[17]
be resected or compromised, but the deltoid function can be preserved, a RTSA can be used [Figures 1 and 2] .
The RTSA is more constrained, and therefore there is decreased risk of proximal migration and instability.
The RTSA accomplishes this by moving the center of rotation more inferior and medial allowing the deltoid
to act with a longer lever arm.

Technique: Prior to surgery, the planned resection of the humerus should be measured on the preoperative
[23]
advanced imaging . This is important to ensure that the appropriate length proximal humeral allograft is
available during the surgery. During the surgery, the allograft can be taken out of the packaging and placed
directly in a warm normal saline solution [Figure 9]. During the resection of the tumor, care should be
taken to preserve the uninvolved glenohumeral capsule and tendon stumps of all the muscles resected. The
deltoid insertion should be spared if possible. The glenohumeral capsule and the respective tendon stumps
should be tagged with sutures for later identification. Once the resection and the humeral osteotomy is