Can septic pedal osteitis be managed in the standing patient?

Abstract

Infection of the hoof is probably the most common cause of lameness in horses. The clinical signs of a hoof infection are variable and septic pedal osteitis can be a potential sequelae of penetrating wounds, subsolar abscesses and laminitis (Gaughan et al. 1989). The cause of infection is normally one or more of the many ubiquitous bacteria living on the hoof or in the horse's environment. Affected horses normally have a history of chronic lameness with drainage of purulent exudate from the foot that often resolves and recurs at a later time. Radiographic examination often will reveal decreased bone density, demineralisation and irregularity of the bone margins at the level of the infected bone (Cauvin and Munroe 1998). Treatment requires a combination of surgical debridement of the infected bone and surrounding tissues in addition to systemic and local antimicrobial therapy. The surgical debridement of the infected bone is normally carried out in the standing sedated horse under regional anaesthesia with the application of a tourniquet to control haemorrhage. However, in horses with a difficult temperament, general anaesthesia is indicated. The sole or hoof wall can be approached initially with hook knifes and motorised instruments to gain access to and allow curettage of the lesion. After the infected tissues are removed the defect is lavaged, topical antibiotics and sterile bandages are applied. Systemic antibiotic administration is continued until a healthy bed of granulation tissue has covered the pedal bone. At this point, application of a hospital plate is indicated to reduce the amount of bandaging materials and reduce the pressure on the surgical site. The terms ‘septic pedal osteitis’ or ‘distal phalanx infection’ were used to search PubMed. Hand searching of references in all the articles identified provided the initial database of literature. Zero RCT, 4 retrospective studies. Articles were considered relevant if the researched terms ‘septic pedal osteitits’ were present in the title, abstract or body of the article. Only retrospective studies that were relatively small in size were identified. There were 3 studies focusing on septic pedal osteitis and one of these considered only foals (Neil et al. 2007). The fourth retrospective study, assessing solar penetrations (Kilcoyne et al. 2011), was included as a subgroup of these cases developed septic pedal osteitis. Cauvin and Munroe (1998) reported the surgical treatment of septic pedal osteitis in 18 horses, in 17 horses the procedure was carried out under general anaesthesia. Furthermore, they reported that under general anaesthesia the surgical debridement and haemorrhagic control was easily achieved. Recent publications in the literature demonstrated a tendency for a standing surgical approach for the treatment of septic pedal osteitis. They proposed several reasons why the standing approach is better compared with general anaesthesia. In addition to avoiding the cost and risk of general anaesthesia, homeostasis, exposure of the affected tissues, radiographic surgical guidance are considered easier in the standing patient. Either a solar or hoof wall approach can be achieved in the standing patient. The management of septic pedal osteitis in the standing patient with the use of regional anaesthesia and the application of a tourniquet is based on weak evidence if the hierarchical evidence based medicine pyramid is considered. Yet there are several recent review articles that suggest the standing approach of septic pedal osteitis is possible and may be advantageous for several reasons. Future studies should aim to address large randomised clinical trials comparing outcomes in the standing patient treated for septic pedal osteítis compared to outcomes of those treated when general anaesthesia is used. Outcome measures should include length of time to return to work and frequency of recurrence. No conflicts of interests have been declared.