Proximal Humerus Nonunion & Malunion

Head-preserving open reduction and internal fixation with a fixed-angle locked plate (or blade plate), combined with bone grafting - commonly an intramedullary FIBULAR STRUT (provides a medial buttress and improves fixation in osteoporotic/comminuted metaphysis) and/or cancellous autograft. Requires a viable head with a fragment large enough to hold fixation and adequate bone stock. Achieves reliable union and preserves the native joint.

For the elderly, poor bone stock, a non-viable or small head fragment, a deficient rotator cuff, or a failed ORIF, reverse TSA is the workhorse - it is cuff-independent and gives reliable pain relief and function. Series report large gains in Constant score and motion, but a high complication/dislocation rate. A LONG-STEM RSA (often cementless, bypassing the nonunion) is used for metadiaphyseal extension.

The pivotal technical lesson: preserve the tuberosities and their attached rotator cuff during RSA for nonunion. Intra-operative resection of the tuberosities significantly increases the dislocation rate (which is already the leading complication), so retain and repair them whenever possible.

Greater-tuberosity malunion (a prominent, superiorly/posteriorly malunited tuberosity) causes subacromial/internal impingement and lost motion - treated by tuberosity osteotomy/reduction, excision of the prominent portion, or acromioplasty. Surgical-neck malunion (angulation) may need a corrective osteotomy; severe malunion with joint damage is treated by arthroplasty (Boileau type 4, with tuberosity osteotomy).