Outcomes of EXOGEN low-intensity pulsed ultrasound in the management of delayed union following elective foot and ankle surgery

M.Koziara, AB. Scrimshire, P.Torres

Introduction
EXOGEN therapy is established in the management of fracture delayed/non-unions. It has recently been recommended by NICE for use in trauma.
Use of EXOGEN in delayed unions in elective foot and ankle surgery has not been previously reported. 

We aim to review the indications and outcomes of EXOGEN therapy in managing delayed union following elective foot and ankle surgery in Freeman Hospital.

Methods
Case notes and imaging were reviewed for all patients receiving EXOGEN therapy following elective foot and ankle procedures between 07/2012-07/2017 in our centre. Collected data included: demographics, smoking status, comorbidities, indication for and type of surgery, duration of EXOGEN therapy and outcomes.

Results
58 patients(18 smokers and 8 diabetic). Mean age:55.
Type of procedure:50 arthrodesis, 8 osteotomy.
Exogen therapy commenced 244-days post-operatively (mean)
Complete Union:24 patients.
Pogress towards union:7 patients.

Union rate:53.4%(n=31).
Complete union time: 177-days(range 44–441).

Non-union rate:46.6%(n=27) despite 330-days treatment(range 72–1112). 

We found no significant differences in age, time to EXOGEN, smoking status or diabetes between the groups. Non-union group had siginificantly longer treatment (p=0.003). Union was more likely following an osteotomy(n=6/8,75%)) or surgery to the hindfoot(n=6/7,86%).

Conclusion
EXOGEN may reduce the number of revision surgeries required. No correlation between age, smoking or diabetes has been found. Union was more likely following an osteotomy / hindfoot surgery. This may help inform clinical decision-making and patient counselling.