Andy Morris BSc(Hons) BVSc CertAVP(GSAS) MRCVS*,
Angus Anderson BVetMed PhD DSAS(Orth) MRCVS
Anderson Abercromby Veterinary Referrals, 1870 Building, Jayes Park Courtyard, Forest Green Road, Ockley. Surrey. RH5 5RR (*Author for correspondence)
Companion Animal Volume 18, Issue 6, pages 264–269, August 2013
This article describes the clinical presentation, diagnosis and management of osteochondrosis dissecans (OCD) of the caudal aspect of the humeral head in an eight-month-old Border Collie.
OCD of the canine shoulder is a frequent cause of forelimb lameness in the dog. A typical presentation of lameness and pain on shoulder extension or flexion is seen in young medium- to giant-breed dogs, but it should be considered in almost all forelimb lameness work-ups. For most cases, management consists of excision of the cartilage flap and careful curettage or forage of the underlying subchondral bone to promote fibrocartilage. For all cases, a mild degenerative joint disease will ensue; however, with appropriate management, a good long-term prognosis can be expected in the majority of cases.
SIGNALMENT AND PRESENTING SIGNS
The dog in this case was an eight month old male neutered border collie. A six week history of intermittent bilateral forelimb lameness was reported with no history of trauma. A repeatable pain response was elicited on extension of both shoulder joints and on firm digital pressure over the caudal humeral head. Care was taken to differentiate shoulder and elbow pain.
Traumatic injury was not suspected. OCD of the caudal humeral head was suggested by signalment, history and clinical signs. The patient was positioned for a mediolateral radiograph of both shoulders.
Arthrotomy allowed excellent visualisation of the defect and retrieval of the cartilage flap. Insufficient healthy fibrocartilage was apparent underneath the flap and forage, or subchondral drilling, perpendicular to the defect was performed. The joint was lavaged with saline to flush out any remaining loose cartilage or bone fragments and routine closure performed.
OUTCOME AND POSTOPERATIVE CARE
The patient was hospitalised overnight with analgesia continued as clinically indicated by the Glasgow Composite Measure Pain Scale. Carprofen was continued 2 mg kg-1 orally twice daily for five days then 2 mg kg-1 once daily for a further 14 days. Confinement indoors to a single room was advised for an initial 14 days. For the next 30 days the patient was allowed twice daily 5 minute lead walks until re-examination six weeks following the surgical procedure. At this time there was no pain on full shoulder joint manipulation and no lameness evident on gait evaluation.
The caudal humeral head is the most common location for the clinical manifestation of OCD in the dog. Diagnosis is suggested by signalment, history and clinical signs. A mediolateral radiographic projection of the shoulder will normally allow conformation of the diagnosis. There is no consensus on best treatment method. Meaningful comparisons among different surgical techniques are not possible due to a failure to provide objective inclusion criteria and valid methods of outcome assessment. Nonetheless for the majority of cases a good to excellent prognosis can be expected. Large defects or those located on the caudocentral aspect of the humeral head may carry a more guarded prognosis. Recent advances in the use osteochondral transplants in dogs are exciting but the long-term advantage of these techniques is currently unknown. This is an interesting area for future development.