The patient is sedated in a clean area and the surgical site clipped and prepared for aseptic surgery.
The last radiograph is placed on the viewer for intraoperative control of the screw positions.
The proximal aspect of the healed incision is excised and the plate approached. The socket for the screw driver is cleaned of tissue and potentially bone and the first screw partially retracted but not removed. One screw after the other is retracted until all screws are accounted for. For some screws additional stab incisions may have to be made, especially for locking head screws. Care has to be taken to assure solid seating of the drill guide in the screw head prior to attempting screw removal. Once all plate screws are identified and partially retracted they are removed followed by removal of the plate.
Radiographs are taken to document the implant removal and identify potential bone spurs that should be removed at the same time. Lag screws initially inserted prior to plate application are usually left in place. The subcutaneous tissues and skin are closed using routine technique. The incision is covered with a stent bandage for the first postoperative days.
2. Plate removal under anesthesia
Plate removal in foals is best performed under anesthesia. Plate removal in adult horses should only be performed under anesthesia if a pool or sling recovery system is available.
The patient is positioned in lateral recumbency on the surgery table with the involved limb uppermost.
The wide area around the surgical site is clipped and prepared for aseptic surgery.
The plate is preferably removed using a minimally invasive approach. In cases where the top of the plate is covering the proximal most aspect of the olecranon and was placed through a longitudinal incision in the triceps muscle, an approx. 7 cm skin incision is performed down to the bone. Circumferential removal of the scar of the original skin incision is optional but results in a more cosmetic result.
Loosening the screws
The indentations in the screw head are thoroughly cleaned to facilitate proper seating of the screw driver. The screws accessible through the incision are partially retracted but not removed.
With the help of a hypodermic needle and digital palpation through the incision in distal direction, the next two screw heads are identified. The needle is positioned between the two screw holes on the middle of the plate as a guide for the scalpel to reach the plate.
After properly clearing the screw heads the screws are partially retracted.
This procedure is repeated until all screws are accounted for.
Once all screws are identified they are removed one by one. Any proliferative bone covering parts of the plate are removed with the help of an old chisel and mallet.
The plate is pared loose from the bone at the top and through sideway movements and upward pull the plate is removed. Any initially inserted interfragmentary screws outside the plate are usually left in place because they are usually covered by bone. The plate bed is curetted and flushed. The incisions are sutured using routine technique and the patient carefully carefully recovered in a hydro pool or sling.
Note: if the reason for plate removal is chronic infection, it may be better to open the initial skin incision completely and curet the fracture bed carefully, followed by installation of a Penrose drain at the distal most aspect of the plate through a separate skin incision.
Prior to skin closure radiographs are taken to document implant removal.
3. Complications of implant removal
Plate removal under anesthesia may result in re-fracture of the olecranon along a screw hole.
Left: the implants of this comminuted healed olecranon fracture was removed because of the owners.
Right: the patient re-fractured the olecranon in the recovery stall, despite a non-violent recovery.
The animal was immediately re-anesthetized and the fracture repaired using the same plate but new screws. In addition a second LCP was applied to the lateral aspect of the olecranon and ulna. The animal recovered uneventfully and the plates remained in place.