• Osseous sequestration is a sporadic problem encountered in cattle, associated frequently with trauma to a site with minimal soft tissue cover (such as limb trapped between metal bars). The limbs, skull, and the ribs are the most commonly encountered sites for these lesions.
• In growing animals, sequestration may occur in the growth plate following hematogenous spread of bacteria.
• The development of a persistent, purulent discharge from a draining tract over the site of sequestration will preclude transport in many countries.
• Excessive periosteal reaction over and around the site may impair normal function and result in persistent low to moderate grade lameness, which may also preclude transport.
• Surgical removal of the sequestrum will in the majority of cases hasten recovery of normal function.
• Successful medical management has been recorded, however, the medical approach often requires a longer period of recovery, may be more expensive overall due to prolonged courses of antimicrobials and pain relief, and is associated with a higher failure rate compared to surgical management.

Uses

Advantages

• Surgical removal will shorten the recovery period.
• Once removed, recurrence of presenting problem should not occur.
• Long term aesthetic appearance is better.
• Higher rate of success compared to medical management.

Disadvantages

• Short term costs are greater.
• Post-operative wound care requires some time commitment.

Technical problems

• The presence of a thick layer of periosteal reactive tissue (involuvrum) over the sequestrum will frequently preclude simply incising the skin to remove the bone fragment. This means that non-standard equipment such as an osteotome and mallet  are usually required for successful field surgery.
• Radiography is not always available on-hand in ambulatory practice. The use of radiography for surgical planning is not always necessary but does help when deciding on incision site, size and depth, as well as assessing the number of fragments for removal .
• Alternative imaging techniques such as ultrasonography or computed tomography (CT) may be used as an alternative to radiography, if available.

Time required

Preparation

• 30 minutes.

Procedure

• 1-3 hours depending on experience of surgeon and location of sequestrum.

Decision taking

Criteria for choosing surgery

• The presence of a large sequestrum (greater than 2cm diameter) is associated with a prolonged recovery if medical management is chosen. Surgery will reduce the recovery period substantially.
• A clear delineation between healthy bone and the sequestrum should be present prior to commencing surgery, to facilitate ease of removal of the sequestrum. Generally, this occurs between 3 and 6 weeks after the initial injury.

Risk assessment

• Radiography allows assessment of the site of injury, to determine whether surgery is necessary. In cases which have been left for a prolonged period (months to years) without treatment, the sequestrum may have already been expelled , in which case surgery is not necessary. In such cases however, the owner should be advised to seek treatment for similar injuries at an earlier stage to reduce welfare compromise associated with lameness due to delayed treatment.