*Review* **Defect Coverage after Forequarter Amputation—A Systematic Review Assessing Different Surgical Approaches**

**Denis Ehrl 1,†, Nikolaus Wachtel 1,\* ,†, David Braig <sup>1</sup> , Constanze Kuhlmann <sup>1</sup> , Hans Roland Dürr <sup>2</sup> , Christian P. Schneider <sup>3</sup> and Riccardo E. Giunta <sup>1</sup>**


**Abstract:** Autologous fillet flaps are a common reconstructive option for large defects after forequarter amputation (FQA) due to advanced local malignancy or trauma. The inclusion of osseous structures into these has several advantages. This article therefore systematically reviews reconstructive options after FQA, using osteomusculocutaneous fillet flaps, with emphasis on personalized surgical technique and outcome. Additionally, we report on a case with an alternative surgical technique, which included targeted muscle reinnervation (TMR) of the flap. Our literature search was conducted in the PubMed and Cochrane databases. Studies that were identified were thoroughly scrutinized with regard to relevance, resulting in the inclusion of four studies (10 cases). FQA was predominantly a consequence of local malignancy. For vascular supply, the brachial artery was predominantly anastomosed to the subclavian artery and the brachial or cephalic vein to the subclavian or external jugular vein. Furthermore, we report on a case of a large osteosarcoma of the humerus. Extended FQA required the use of the forearm for defect coverage and shoulder contour reconstruction. Moreover, we performed TMR. Follow-up showed a satisfactory result and no phantom limb pain. In case of the need for free flap reconstruction after FQA, this review demonstrates the safety and advantage of osteomusculocutaneous fillet flaps. If the inclusion of the elbow joint into the flap is not possible, we recommend the use of the forearm, as described. Additionally, we advocate for the additional implementation of TMR, as it can be performed quickly and is likely to reduce phantom limb and neuroma pain.

**Keywords:** forequarter amputation; targeted muscle reinnervation; osteomusculocutaneous flap; fillet flap; epaulette flap; interscapulothoracic amputation; spare parts; microsurgery; reconstructive surgery
