Pedographic and clinical assessment of total contact cast immobilization in diabetic foot syndrome

Aim.
To estimate offloading efficiency of total contact cast (TCC) and determine factors, affecting trophic ulcer response to treatment with TCC, as well as ways of their compensation.
Methods.
30 patients, receiving an outpatient treatment with TCC for diabetic foot syndrome, underwent routine clinical examination, pedography and walking activity monitoring. We assessed degree of pressure reduction on the planta and the lesion area in particular, in its correlation with treatment outcome.
Results.
According to pedography data, TCC reduced peak pressure (maximum for all plantar zones) for 20% (from -70% to 84%) and pressure in the lesion area for 55% (-100%; +359%). Similar change was observed for "pressure-time" integral. Percentage of patients with peak pressure in ulceration area <100 kPa increased from 7 (23%) to 17 (57%). Healing of the ulcer was achieved in 21 patients (70%). Mean healing time was 30 days (17-278). In 2 cases treatment with TCC was ceased prematurely at the wish of the patient, while in 7 cases (23%) - due to treatment inefficiency. Risk factors for TCC inefficiency were found to be acute stage of diabetic osteoarthropathy, resistant lesion microflora and critical level of microbial colonization according to NERDS scale (p<0.05). Patients who did not respond to TCC treatment also required antibiotic therapy significantly more often and featured skin roughness under TCC (5 from 7 against 3 from 21). Walking activity, age, duration of diabetes, HbA_1c levels and percentage of smokers was not significantly different between the groups. Peak pressure in the ulceration zone was higher in patients with TCC inefficiency, although the difference was not statistically significant (156 (19-365) against 82 (12-72) kPa, p>0.05).
Conclusion.
(1) TCC is an effective day-to-day offloading method, ensuring healing of trophic ulcers in 70% of cases.
(2) During acute stage of diabetic osteoarthropathy with ulceration in projection of shifting bone fragments TCC is ineffective; in this case surgical correction (wound closure) is indicated prior to TCC treatment.
(3) If ulcer is unresponsive to TCC, while ischemia and osteomyelitis are ruled out, critical microbial colonization (including resistant strains) or inadequate offloading are probable.

diabetes mellitus, diabetes complications, diabetic foot, foot ulcer, pedography, offloading dressing