Evaluation of a Novel Orthosis for the Non-Operative Management of Hallux Limitus

Abstract

Category: Midfoot/Forefoot Introduction/Purpose: Affecting an estimated 1 in 40 adults over the age of 50, hallux limitus is among the leading arthridites of the foot and ankle, with growing incidence reflecting an aging population. Despite its prevalence and disease burden, treatment of the condition remains equivocal. Many patients fail initial conservative measures (e.g., NSAIDs, physical therapy, corticosteroid injections) and may be averse to or ineligible for surgery. For others, there exists controversy surrounding the indications and outcomes of various surgical procedures. As such, there is demand for new means of non-operative management. The present study sought to examine the impact of a novel in-shoe device, the Hallux Limitus Forefoot Orthosis (HLFO), on plantar pressure, foot function, and pain in patients with hallux limitus. Methods: Twenty adult patients with symptomatic hallux limitus were recruited for the study. Diagnosis of hallux limitus was confirmed via physical exam and plain radiography. Patients with diabetes, pre-diabetes, peripheral artery disease (Ankle Brachial Index < 0.70), neuropathy (positive Semmes-Weinstein monofilament test), or lower extremity wounds were excluded. At baseline, participants completed the Foot Function Index (FFI) and reported foot pain on a visual analogue scale (VAS) from 0 to 10. Heat map profiles were also generated using a plantar pressure sensor. The HLFO was then issued to participants, who were instructed to wear it in standard athletic shoes. Participants were contacted by phone after 2 weeks for feedback and to inquire about any adverse events. One participant was lost to follow-up. At 4 weeks, participants returned, and FFI, VAS pain, and plantar pressure measurements were repeated with the HLFO on. Results: Mean FFI decreased significantly from 43.0% (± 18.8%) to 11.0% (± 9.8%) following use of the HLFO, t(18) = 6.78, p <0.001. Eighteen of the 19 (94.7%) participants experienced a decrease in FFI. One participant reported an increase of 5.9%. Mean VAS pain score also decreased significantly from 4.87 (± 2.16) to 1.18 (± 1.84) following use of the device, t(18) = 6.57, p < 0.001. Eighteen of the 19 (94.7%) participants experienced a decrease in pain, with 12 (63.2%) reporting a final pain score of 0, indicating “no pain.” One participant experienced an increase in pain score from 5.0 to 5.5. Plantar pressure profiles with the HLFO on revealed redistribution of weight from the hallux MTP joint to the lesser digits. Conclusion: The HLFO was well tolerated by participants and effectively reduced pressure on the hallux MTP joint. It resulted in significant improvements in foot function and pain for nearly all participants, with the majority reporting complete resolution of their pain. Based on these findings, the HLFO offers an enticing option for patients seeking non-operative treatment for hallux limitus. Future studies could look at the long-term impact of the device on patients’ foot health, quality of life, and decision to pursue surgery.