Salter-Harris type II metacarpal and metatarsal fracture in three foals. Treatment by minimally-invasive lag screw osteosynthesis combined with external coaptation.

The research article discusses a minimally invasive procedure used in treating Salter-Harris type II fractures in the third metacarpal and metatarsal bones of three young foals aged between 2 weeks and 4 months. The resulting outcomes were positive, with all fractures healing completely and no limb deformities observed.

Objective of the Study

• The main aim of this study was to discuss the use and effectiveness of a minimally invasive procedure, lag screw osteosynthesis, combined with external coaptation in treating Salter-Harris type II fractures in young horses.

Methodology

• The study focused on three young horses, aged from two weeks to four months, all suffering from Salter-Harris type II fractures in the third metacarpal or metatarsal bones.
• The surgery was conducted under general anaesthesia, with each foal placed in lateral recumbency (lying on their side).
• During the operation, the broken bone fragments were first realigned (fracture reduction), then the metaphyseal fragment was stabilized using two cortical screws. These screws were inserted under fluoroscopic control, a type of imaging technique using X-rays to obtain real-time moving images of the internal structures of the foal.
• After the surgical procedure, a cast was applied to the affected area for at least two weeks to support and protect the healing bone.

Results

• The procedure achieved positive results, with each of the three foals experiencing complete healing of the fractures.
• Furthermore, there were no observed cases of angular limb deformity, a potential negative outcome from broken limb fractures in young, growing animals.
• However, each foal did experience moderate transient digital hyperextension post cast removal, a temporary condition where the joints in a digit (finger or toe) overextend or bend backward.

Conclusion

• The research concluded that the combined treatment of internal fixation with two cortical screws and external coaptation (bandaging or splinting) effectively stabilizes Salter-Harris type II fractures in young horses. Furthermore, this treatment method preserved the injured physis’ potential for longitudinal growth, an essential aspect for a growing young animal.