Retrospective study of palmar/plantar annular ligament injury in 71 horses: 2001-2006.
Authors: Owen K R, Dyson S J, Parkin T D H, Singer E R, Kristoffersen M, Mair T S
Journal: Equine veterinary journal
Summary
# Editorial Summary: Palmar/Plantar Annular Ligament Injury in 71 Horses Primary injury to the palmar/plantar annular ligament (PAL) has received limited documentation in the equine literature despite the well-established problem of secondary constriction of the digital flexor tendon sheath. Owen and colleagues conducted a retrospective analysis across three veterinary clinics to characterise PAL desmopathy, establish prevalence patterns, and evaluate treatment outcomes in 71 horses presenting with ultrasonic evidence of PAL thickening (≥2 mm). The cohort comprised predominantly middle-aged and older general purpose riding horses, with hindlimb involvement more common than forelimbs, and nearly half presented with bilateral PAL thickening despite often showing unilateral lameness. Critically, less than 50% of horses returned to athletic function regardless of whether treatment was conservative or surgical (desmotomy ± tenoscopic evaluation), and prognosis was significantly worse in cases with concurrent forelimb and hindlimb involvement or simultaneous subcutaneous fibrosis and digital flexor tendon sheath lesions. These findings suggest that whilst isolated PAL desmopathy carries a more favourable prognosis, the presence of polyarticular or multifactorial pathology substantially compromises return to work—a consideration that should inform informed consent discussions with owners and refine case selection for surgical intervention in practice.
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Practical Takeaways
- •PAL injury prognosis is guarded: counsel owners that <50% return to work regardless of whether you choose conservative management or surgical desmotomy
- •Assess bilaterally and examine both front and back legs—bilateral involvement or multiple limb pathology indicates significantly poorer prognosis
- •Ultrasonographic findings (PAL thickness, fibrosis presence, DFTS involvement) can help predict outcomes; isolated PAL disease alone carries better prognosis than combined pathology
Key Findings
- •PAL desmopathy occurred more frequently in hindlimbs than forelimbs across 71 horses
- •Less than 50% of horses returned to athletic function regardless of treatment method (conservative vs. surgical desmotomy)
- •Bilateral PAL thickening and concurrent fore- and hindlimb injuries significantly worsened prognosis
- •Horses with isolated PAL desmopathy without concurrent DFTS lesions or fibrosis had the best outcome