Olecranon Osteotomy Exposure for Distal Humeral Fracture Treatment.

Abstract

Background: Olecranon osteotomy (OO) is commonly utilized to improve exposure when treating intra-articular distal humeral fractures. A chevron-shaped osteotomy facilitates reduction and increases surface area for healing¹. Following distal humeral fracture reduction and fixation, the OO fragment is fixed with a precontoured plate. The OO technique yields comparable outcomes to alternative techniques^1,2.

Description: The technique is performed as follows. (1) Imaging is reviewed and preoperative planning is performed. (2) The patient is positioned in the lateral decubitus position with the operative extremity placed over a bolster. (3) A longitudinal posterior skin incision is centered just medial or lateral to the tip of the olecranon. Full-thickness skin flaps are raised medially and laterally. (4) The ulnar nerve is identified and mobilized for later anterior subcutaneous transposition. (5) An OO is performed at the non-articular "bare area" of the trochlear notch with an oscillating saw and completed with an osteotome. (6) Open reduction and internal fixation of the distal humerus is performed. (7) The osteotomy fragment is reduced, and a precontoured plate is applied. (8) A small longitudinal slit in the distal triceps over the proximal edge of the plate decreases plate prominence and is repaired with suture. (9) The subcutaneous tissues and skin are closed in the usual manner.

Alternatives: Alterative techniques include extra-articular OO, triceps splitting, triceps reflecting, and lateral para-olecranon combined with a medial approach. Multiple drill holes and a thin osteotome can help mitigate the kerf created by the oscillating saw. Alternative fixation methods include a predrilled 6.5-mm intramedullary screw, a tension band construct, suture fixation, or a one-third tubular plate.

Rationale: The OO technique provides improved exposure when compared with alternative techniques, enabling accurate reduction and fixation of distal humeral fractures^1-3. Wilkinson and Stanley found that OO exposed the distal humeral articular surface to a greater degree than the triceps-splitting and triceps-reflecting approaches³. OO has not been associated with triceps weakness, unlike some of the alternative techniques².

Expected outcomes: The incidence of good-to-excellent outcomes is similar when comparing the techniques for exposure of intra-articular distal humeral fractures⁴. Osteotomies united in all patients in 2 reported series, totaling 84 cases^1,2. Removal of symptomatic hardware used in OO fragment fixation can occur in a small subset of patients^1,2.

Important tips: Provisionally size a precontoured plate and fix it on the olecranon to aid in later reduction and fracture fixation.The bare area is the desired position for the OO because of its natural lack of cartilage^5,6. This non-articular bare area is located just distal to the deepest portion of the trochlear notch, approximately 2 to 2.5 cm distal to the olecranon tip^5,6.An (apex-distal) chevron osteotomy angle of ∼130° will help to keep the osteotomy within the non-articular bare area⁶.Beginning on the dorsal surface of the ulna, directly posterior to the bare area, an oscillating saw is utilized to create a chevron osteotomy to subchondral bone, perpendicular to the long axis of the ulna^5,6.The OO is completed by fracturing through the osteochondral surface, which leaves an irregular chondral cancellous surface that can accurately interdigitate. This facilitates later reduction and stability of the osteotomy.Anatomic articular reduction of the OO is not solely judged on the dorsal cortical bone because of the kerf removed by the saw blade. Instead, examination of the articular surface of the trochlear notch is the primary assessment of reduction.Placement of suture through the proximal portion of the plate aids in the repair of the longitudinal split of the distal triceps.Successful treatment of distal humeral fractures requires accurate reduction and rigid fixation aided by adequate exposure achieved through OO.

Acronyms and abbreviations: ORIF = open reduction and internal fixationOT = occupational therapyHWR = hardware removalK-wire = Kirschner wireROM = range of motion.