• Midbody fractures of the proximal sesamoid bones   Proximal sesamoid: fracture  require internal fixation to achieve a bony union and to restore the function of the suspensory apparatus and fetlock joint.
• Constant tension on the fracture line by the suspensory apparatus   →   instability with poor healing, often fibrous union and chronic pain in midbody fractures unless internal fixation is used.

Approaches

• Arthroscopic - via the palmar pouch of the fetlock joint and the proximal digital flexor tendon sheath.
• Arthrotomy - of the fetlock joints and synoviotomy of the digital flexor tendon sheath.

Uses

• Mid-body fractures of the proximal sesamoid bone not amenable to other forms of surgical fixation   Proximal sesamoid bone: fracture repair - lag screw  .

Advantages

• Improves fracture stability   →   bony union and restoration of suspensory apparatus function.
• Requires no special equipment.
• Technically less demanding than lag screw fixation   Proximal sesamoid bone: fracture repair - lag screw   but requires good anatomical knowledge.

Disadvantages

• Can be difficult to acheive good apposition and stable reduction.
• Wires require removal after fracture healing.
• Less stable than lag screw technique   Proximal sesamoid bone: fracture repair - lag screw   and consequently worse prognosis for successful repair.
• Requires longer period of cast immobilization than lag screw fixation.

Alternative techniques

• Conservative treatment   Proximal sesamoid: fracture  .
• Surgical removal   Proximal sesamoid: fracture - arthroscopic removal   of very small fragments.
• Lag screw fixation   Proximal sesamoid bone: fracture repair - lag screw  .
• Cast immobilization.

Time required

Preparation

• General anesthesia induction and maintenance: 20 min.
• Aseptic preparation: 10 min.

Procedure

• Surgery (including bone grafting): 60-70 min.
• Cast application: 20-30 min   Musculoskeletal: external fixation - casts  .

Decision taking

Criteria for choosing test

• Complete assessment of case   Proximal sesamoid: fracture  with use of radiography   Forelimb: radiography  to determine fracture type and ultrasound   Ultrasonography: flexor tendon  to assess soft tissue suspensory apparatus damage.
• Other injuries of fetlock region may be present.