Endoprosthetic Reconstruction for Proximal Humerus Tumors

Abstract

Purpose of the review: Anatomic and reverse endoprosthetic reconstruction are two common surgical options used after tumor resection of the proximal humerus. The purpose of this article is to provide an overview of the functional outcomes and complications of modern anatomic and reverse endoprostheses.

Recent findings: The anatomic endoprosthesis has traditionally been a successful reconstructive technique as it provided a stable platform upon which the hand and elbow could function. However, the reverse endoprosthesis has gradually replaced the anatomic endoprosthesis given that its semi-constrained design affords greater stability. Patients with reverse endoprostheses have improved motion, patient-reported outcome scores, and revision-free implant survivorship compared to those with anatomic endoprostheses. Shoulder function may be further improved with a reverse allograft prosthetic composite (APC) due to reconstruction of the rotator cuff tendons or by transferring the latissimus dorsi and teres major tendons to recreate the function of the posterosuperior rotator cuff muscles. The short-term functional improvement observed with the use of an allograft reconstruction, however, may diminish with longer follow-up due to delayed graft complications, such as resorption, nonunion, and fracture. In most patients undergoing oncologic resection of the proximal humerus, the reverse endoprosthesis or reverse APC is recommended due to improved functional outcomes and reduced postoperative complications compared to other reconstructive techniques.

Keywords: Complications; Endoprosthesis; Megaprosthesis; Outcomes; Proximal humeral tumors; Reverse shoulder arthroplasty.

Fig. 1

Metastatic breast cancer lesion of the proximal humerus (A) T2 fat-saturated imaging demonstrates bulky edema in the joint and along the lateral cortex. B T1-weighted imaging shows likely breach of the lateral cortex. The areas of bulky edema are isointense to the lesion (arrow), which is concerning for viable tumor cells

Fig. 2

Malawer classification. The areas highlighted in red are to be resected. Type I and Type V resections are generally amenable to endoprosthetic reconstruction

Fig. 3

48 year-old female with (A) metastatic breast cancer lesion of the proximal humerus. B Cementless reverse endoprosthesis at 1-year follow-up

Fig. 4

69 year-old female with (A) dedifferentiated chondrosarcoma of the proximal humerus with extension into the subdeltoid space. B T1-weighted image with contrast shows a large expansile lesion without extension into the glenoid. C Cemented reverse endoprosthesis at 1-year follow-up

Fig. 5

63 year-old male with (A and B) undifferentiated pleomorphic sarcoma extending from the humeral shaft to the proximal humerus. The patient sustained a prior humeral shaft fracture that was treated with plate fixation. C Reverse endoprosthesis with compressive osseointegration technique (arrow) used to achieve fixation in the distal humeral shaft