Clinical and patient reported outcomes following low intensity pulsed ultrasound (Exogen) for established post-traumatic and post-surgical non-union in the foot and ankle

T. Karim, H. Majeed, J. Davenport, T. Clough

Background: Contention exists as to the efficacy of Low Intensity Pulsed Ultrasound (Exogen) on bony healing following non-union. We examine clinical and patient reported outcomes following Exogen treatment, in patients following post-traumatic or post-surgical non-union in the foot and ankle.

Methods: Demographics, clinical and patient reported outcomes (pre and post treatment MOXFQ, EQ5D-5L and VAS scores) were gathered for 50 consecutive patients (February 2015 - February 2018) who underwent Exogen treatment for symptomatic and radiological non-union for a variety of foot and ankle pathology. The economic impact was also analysed.

Results: There were 15 fracture non-unions (tibia, ankle), 20 non unions from midfoot/forefoot procedures (talonavicular, tarsometatarsal, base 2^nd metatarsal, base 5^th metatarsal) and 15 from hindfoot procedures (ankle/triple/TTC nailing). 13 patients (2,8,3) had diabetes mellitus and 6 (4,0,2) were smokers. 40 patients (14/16/10) clinically united, 4 (0,1,3) patients noticed no significant improvement but did not want to consider surgical intervention and 6 (1,3,2) patients failed treatment and progressed to revision surgery. Xray or CT scan was used to define radiographic confirmation of union post-treatment. Of those that clinically healed, radiographic union was found in 72% (29/40). PROM data showed statistically significant improvements (P < 0.05) at an average of 6 months post treatment. Exogen healed 93% in the fracture group, 80% in the midfoot/forefoot group and 67% in the hindfoot group. Significant cost savings were realised with the use of Exogen for this cohort of patients.

Discussion: Overall, 80% of patients with foot and ankle non-union improved clinically to discharge, (with no need for further intervention), with significant improvements in PROM scores. Poorer results may be observed in hindfoot procedures. The appropriate use of Exogen for established non-union in the foot and ankle is a safe, valuable and economically viable clinical option as an alternative to revision surgery.