Fracture-pattern-related therapy concepts in distal humeral fractures

Abstract

Around one third of humeral fractures and 2-6% of all fractures occur to the distal part of the humerus. There is a bimodal distribution differentiating between young male patients with high-energy and elderly female patients with low-energy trauma related to osteoporosis. The AO classification and Dubberley subclassification are used in daily routine. Most fractures are diagnosed on radiographs. For further evaluation, three-dimensional computed tomography is recommended, especially for comminuted or complex fractures. Owing to the long immobilization and resultant poor functional outcome, conservative treatment is followed for inoperable patients. The operative approach and osteosynthesis depend on the fracture pattern. In A1 avulsion fractures, open reduction and screw fixation are recommended. In A2/A3 fractures, a triceps-sparing approach following a 90° double-plate construction (radial dorsal/ulnar lateral) with locking plates is favored. Partial articular B1/B2 fractures are exposed via a medial or lateral approach using unilateral locking plates to stabilize the medial/lateral column. Coronal shear fractures (B3) are classified after Dubberley and are treated via an extended Kocher approach and headless compression screws in anteroposterior direction. If there is a further posterior comminution or a lateral column fragment, stabilization is needed for the lateral/medial column with a precontoured locking plate. In solely articular fracture patterns, a dorsal approach with either a 90° or 180° double-plate construction is advised. If a reconstruction is not possible owing to fracture complexity or bone quality, total elbow arthroplasty is a viable option. However, lifelong limitation in weight-bearing up to 5 kg, limited longevity, and the potential for complicated revision surgery should be considered.

Keywords: AO classification; Double plate constructions; Dubberley sub classification; Headless compression screws; Lateral approach; Total elbow arthroplasty.

Fig. 1

Classification of fractures of the distal humerus. a AO classification [5]: extra-articular (type A), partial articular (type B), and complete articular fracture (type C); b Dubberley classification for coronal shear fractures (AO B3 fractures; [35]): facture of the capitellum (type 1), capitellum and trochlea as single piece (type 2), and capitellum and trochlea as separate fragments (type 3) with the absence (type A) or presence of a dorsal comminution (type B)

Fig. 2

Surgical approaches: a lateral approach [36]; b paratricipital approach; c Bryan–Morrey approach (triceps reflecting); d olecranon osteotomy; e triceps-splitting approach. FCU flexor carpi ulnaris, ECU extensor carpi ulnaris. (b–e modified from [5])

Fig. 3

Extra-articular avulsion of the ulnar epicondyle, AO 13 A1.2 (14-year-old female patient). a Preoperative computed tomography (CT), b owing to the small fragment, the fracture is treated with only one screw

Fig. 4

Extra-articular metaphyseal fracture, AO 13 A2 (60-year-old male patient). a Preoperative radiographs; b 90° double-plate construction (radial dorsal/ulnar) with anatomically preshaped 3.5 mm locking compression plates (LCP) and free cortical screws

Fig. 5

Coronal shear fracture with radial metaphyseal fracture extension, AO 13 B3/Dubberley 2B (54-year-old female patient). a Preoperative computed tomography image with three-dimensional reconstruction; b extended radial approach with surgical radial dislocation; c reduction and temporary fixation with K‑wires; d headless compression screws in anterior–posterior direction and an additive locking plate

Fig. 6

Repositioning techniques for complete intra-articular fractures. a Repositioning of the joint unit, transcondylar screw, and repositioning against the shaft; b column reposition: reconstruction of one column and repositioning of the joint unit against the column

Fig. 7

Nonreconstructable distal humeral fracture, AO 13 C3 (88-year-old female patient). a Preoperative computed tomography with three-dimensional reconstruction; b, c implantation of cemented linked total elbow arthroplasty using a triceps-on approach; d postoperative radiographs