33rd Annual Scientific Meeting proceedings

Traumatic olecranon fractures are seen with relative frequency in equine clinics. Fractures  are categorised from I-V according to their location and orientation. Some non-displaced (type II,III,IV) Olecranon fractures can be managed conservatively through a long period of box rest, however displacement and non-union is not uncommon. Surgical intervention typically involves internal fixation with a combination of locking compression plates and lag screws. Fixation under general anaesthesia involves a certain degree of risk associated with implant failure during recovery. Internal fixation in the standing horse negates this risk and has similarly successful outcomes. Case selection for standing surgery is important; horses with non or minimally displaced type II or V fractures in which triceps function is maintained are optimal cases. The technique was published recently (Jimenez-Rihuete & O’Meara, 2023).

Surgical preparation: Horses are administered antimicrobials and NSAIDs and sedated as required using intravenous alpha-2 agonists (0.01mg/kg Detomidine) and morphine sulphate (60mg) and positioned in the surgery room. The affected limb should be positioned with a slightly toe-in position to improve access to the olecranon and with the limb either in front of or behind the contralateral limb to facilitate intra-operative radiography. A wide area is clipped including the forearm to the level of the carpus, the thorax and the sternum. A subcutaneous line block is placed using lidocaine at the site of the proposed incision (caudolateral olecranon) with deeper intra-muscular infiltration of local anaesthetic on either side of the olecranon. Both forelimbs are draped using sterile co-plusÒ. Two large plain drapes are placed around the neck and the thorax and fastened with towel clips.

Surgical technique: A caudolateral incision is made over the palpable olecranon between the ulnaris lateralis and the ulnar head of the deep digital flexor and continued until the fracture is visible. Further lidocaine is injected on either side of the olecranon prior to any drilling since we have observed that horses frequently react to initial drilling of the periosteum. Access to the proximal aspect of the olecranon is limited. A narrow LCP plate is used with 4.5mm AO cortical rather than locking screws, although the use of locking screws has been reported by Jimenez-Rihuete & O’Meara (2023). Placement of a separate lag screw has been attempted by the author but it has proved very difficult to achieve suitable access to complete this as compared to fracture repair performed under general anaesthesia.  Intra-operative radiography involves a weightbearing medio-lateral view. Dependant upon the position of the limb there is inevitably a degree of obliquity, especially of the proximal aspect of the olecranon, this should be taken into consideration when placing implants. 

Cases
The author reports on 5 cases of olecranon fractures that have been repaired with internal fixation in the standing sedated horse. In addition; treatment of one fracture by ostectomy of the proximal ulna and internal fixation of a proximal radial fracture in a standing sedated horse is reported. 

Reference
Jimenez-Rihuete P. and O’Meara B. (2023) Three cases of olecranon fracture repair in the standing horse. Equine Veterinary Education 35(3):e193-e199