Two-phalange fifth toe a ‘common variant’
MedWire News: UK research challenges common wisdom on the anatomy of the little toe, finding that over 40% of patients have two rather than three bones.
Just 55.3% of 606 patients who underwent foot radiography over an 8-week period at the Royal Liverpool University Hospitals National Health Service trust had the normal distribution of three phalanges and two interphalangeal joints in their fifth toe, report Laurence Moulton (Royal United Hospital Bath NHS Trust, UK) and co-workers.
Radiographs demonstrated that 44.4% of patients had two phalanges and one interphalangeal joint in their fifth toe. Bilateral imaging of 49 patients showed that 43.7% had two and 51.5% had three phalanges, with 4.8% of patients having mismatched feet.
"This observation has potential clinical implications with regard to the management of disorders of the fifth toe," say Moulton et al, in Foot and Ankle Surgery, who explain that patients undergoing deformity surgery with one rather than two joints may be suitable for screw fixation.
This technique offers benefits over wire fixation, such as increased likelihood for fusion, a reduced risk for pin-site infection, and greater stability, leading to a reduced risk for deformity recurrence, they say.
"The results of our review demonstrate the importance of obtaining adequate radiographs of the foot when assessing disorders of the fifth toe and prior to consideration of any surgical procedure," the team concludes. "This will aid in preoperative planning and ensure that incisions are placed in the correct location over the interphalangeal joint rather than over the synostosis."
By Lynda Williams