Reverse shoulder-allograft prosthesis composite, with or without tendon transfer, for the treatment of severe proximal humeral bone loss

Abstract

Background: The treatment of severe proximal humeral bone loss (PHBL) secondary to tumor resection or failed arthroplasty is challenging. We evaluated the outcomes and complications of reconstruction with reverse shoulder-allograft prosthesis composite (RS-APC), performed with or without tendon transfer.

Methods: An RS-APC procedure was performed in 25 consecutive patients with severe PHBL (>4 cm): 12 after failed reverse shoulder arthroplasty, 5 after failed hemiarthroplasty for fracture, 6 after failed mega-tumor prosthesis placement, and 2 after tumor resection. The median length of humeral bone loss or resection was 8 cm (range, 5-23 cm). Humeral bone graft fixation was obtained with a long monobloc reverse stem and a "mirror step-cut osteotomy," without plate fixation. Nine infected shoulders underwent a 2-stage operation with a temporary cement spacer. In addition, 9 patients (36%) underwent an associated L'Episcopo procedure. The median follow-up duration was 4 years (range, 2-11 years).

Results: Overall, 76% of patients (19 of 25) were satisfied. In 8 patients (32%), a reoperation was needed. At last follow-up, we observed incorporation at the allograft-host junction in 96% of the cases (24/25); partial graft resorption occurred in 3 cases and severe in 1. The median adjusted Constant score was 53% (range 18-105); Subjective Shoulder Value, 50% (range 10%-95%). Additional tendon transfers significantly improved active external rotation (20° vs. 0°, P < .001) and forward elevation (140° vs. 90°, P = .045).

Conclusions: (1) Shoulder reconstruction with RS-APC provides acceptable shoulder function and high rates of graft survival and healing. (2) Additional L'Episcopo tendon transfer (when technically possible) improves active shoulder motion. (3) The use of a long monobloc (cemented or uncemented) humeral reverse stem with mirror step-cut osteotomy provides a high rate of graft-host healing, as well as a limited rate of graft resorption, and precludes the need for additional plate fixation. (4) Although rewarding, this reconstructive surgery is complex with a high risk of complications and reoperations. The main advantages of using an allograft with a reverse shoulder arthroplasty (compared with other reconstruction options) are that this type of reconstruction (1) allows restoration of the bone stock, thus improving prosthesis fixation and stability, and (2) gives the possibility to perform a tendon transfer by fixing the tendons on the bone graft to improve shoulder motion.

Keywords: Proximal humeral bone loss; failed shoulder arthroplasty; mega-tumor prosthesis (MTP); reverse shoulder–allograft prosthesis composite (RS-APC); revision; tumor of proximal humerus.