Duration of total contact casting for resolution of acute Charcot foot: a retrospective cohort study

Background: Charcot neuroarthropathy (Charcot foot) is a highly destructive joint disease of the foot and ankle. If there is delayed diagnosis and treatment, it can lead to gross deformity, instability, recurrent ulceration and/or amputation. Total contact casting (TCC) is a treatment commonly used to immobilise the foot and ankle to prevent trauma, further destruction and preserve the foot structure during the inflammatory phase. At present, there is limited Australian data regarding the duration of TCC treatment for resolution of acute Charcot foot, and whether there are any patient and clinical factors affecting its duration. Therefore, this study aimed to address these deficiencies. Methods: This study presents a retrospective analysis of 27 patients with acute Charcot foot attending for TCC treatment at a high-risk foot service (HRFS) in a large metropolitan health network in Melbourne, Australia. Over a three-year period, data were retrospectively collected by reviewing hospital medical records for clinical, demographic, medical imaging and foot examination information. To explore between-group differences, independent samples t-tests, Mann-Whitney U tests, Chi-square tests, and/or Fisher’s exact tests were calculated depending on data type. To evaluate associations between recorded variables and duration of TCC treatment, mean differences, odds ratios (OR) and 95% confidence intervals were calculated. Results: Mean age was 57.9 (SD, 12.6) years, 66.7% were male, 88.9% had diabetes, 96.3% had peripheral neuropathy, and 33.3% had peripheral arterial disease. Charcot misdiagnosis occurred in 63.0% of participants, and signs and symptoms consistent with acute Charcot foot were present for a median of 2.0 (IQR, 1.0 to 6.0) months prior to presenting or being referred to the HRFS. All participants had stage 1 Charcot foot. Of these, the majority were located in the tarsometatarsal joints (44.4%) or midfoot (40.7%) and were triggered by an ulcer or traumatic injury (85.2%). The median TCC duration for resolution of acute Charcot foot was 4.3 (IQR, 2.7 to 7.8) months, with an overall complication rate of 5% per cast. Skin rubbing/irritation (40.7%) and asymmetry pain (22.2%) were the most common TCC complications. Osteoarthritis was significantly associated with a TCC duration of more than 4 months (OR, 6.00). Post TCC treatment, 48.1% returned to footwear with custom foot orthoses, 25.9% used a life-long Charcot Restraint Orthotic Walker, and 22.2% had soft tissue or bone reconstructive surgery. There were no Charcot recurrences, however, contralateral Charcot occurred in 3 (11.1%) participants. Conclusions: The median TCC duration for resolution of acute Charcot foot was 4 months, which is shorter or comparable to data reported in the United Kingdom, United States, Europe, and other Asia Pacific countries. Osteoarthritis was significantly associated with a longer TCC duration. The findings from this study may assist clinicians in providing patient education, managing expectations and improving adherence to TCC treatment for acute Charcot neuroarthropathy cases in Australia.