Calcified Leg Ulcers in Older Patients: Clinical Description, Morphology, and Chemical Characterization

SLR - October 2022 - Jaclyn D. Wessinger, DPM

Reference:
Hester Colboc, MD, Juliette Fontaine, MD, Dominique Bazin, PhD, Vincent Frochot, PhD, Emmanuel Letavernier, PhD, Michel Daudon, PhD, Naomi Laporte, Stéphan Rouzière, PhD, Michael Reby, MD, Agnes Galezowski, MD, Christine Forasassi, MD, Sylvie Meaume, MD, Calcified Leg Ulcers in Older Patients: Clinical Description, Morphology, and Chemical Characterization, The Journals of Gerontology: Series A, Volume 77, Issue 1, January 2022, Pages 27–32, https://doi.org/10.1093/gerona/glab223

Level of Evidence: Level III

Scientific Literature Review:
Jaclyn D. Wessinger, DPM

Residency Program: 
Geisinger Community Medical Center, Scranton PA

Podiatric Relevance:
Dystrophic calcifications (DC) perpetuate inflammatory reactions and prolong chronicity of ulcerations. DC is associated with a host of diseases although its pathogenesis is not well-fathomed. The current goal was to evaluate pathogenesis of calcified leg ulcerations including physicochemical composition. There is no standard treatment algorithm for DC. Calcium-channel blockers, minocycline, bisphosphates, topical sodium thiosulfate, and surgical debridement have been described with capricious results. Calcifications often extend beyond the borders of the ulceration making complete debridement impracticable. DC furthermore perpetuates resistance to compression in venous insufficiency. This conundrum leaves few options for patients with DC.

Methods:
A prospective study was completed at Rothschild Hospital in Paris from January 2018 to December 2019. Patients were screened for DC by palpation. Biological variables included: arteriopathy defined by ABI < 0.90; malnutrition defined by BMI < 21 kg/m2 and/or serum albumin < 35 g/L; chronic kidney disease defined by GFR < 60 mL/min; hypercalcemia defined by serum calcium > 2.6 mmol/L. Patients were clinically screened for P. aeruginosa colonization noting greenish hue to wounds. Physicochemical analysis was performed via µFourier Transform Infra-Red (FT-IR) spectroscopy, Field Emission Electron Microscopy (FE-SEM), and X-ray Fluorescence (XRF). 

Results:
Patients (n=143) were treated from January 2018 to December 2019 with ten (7%) exhibiting DC. Patients with DC were likely to have venous insufficiency (p = .015), hypercalcemia (p = .041), P aeruginosa (p = .026) exhibit longer healing (p = .0072) and be nondiabetic females. Subcutaneous calcifications associated with vascular calcifications were found on x-ray in four cases. 
Five DC were extracted for physicochemical analysis. FE-SEM showed lacunar spheres in two cases, compatible with bacterial imprints. In FT-IR, all DC were composed of apatite and calcium phosphate. Out of 5 DC, calcium and phosphor minerals were identified with zinc and strontium.

Conclusions: 
Prevalence of DC was 7%, mostly affecting women with venous insufficiency, colonization by P aeruginosa and exhibition of hypercalcemia. Calcifications were found to be composed of apatite and zinc, two with associated bacterial imprints. 
Limitations of this study include small DC sample size. Evaluation of DC is limited secondary to the rarity of the phenomena; not all chronic venous wounds exhibit calcifications. Secondarily, palpation was utilized to diagnose DC; x-ray was not performed on each patient and prevalence of DC may have been understated. Tertiarily, authors evaluated for P. aeruginosa clinically and did not quantify existence of the bacteria. Variations in evaluator perception may have perpetuated inconsistent results. Interestingly, those patients thought to be colonized with P. aeruginosa did display bacterial imprints on FE-SEM. 
It may be concluded that early management of venous insufficiency is key to DC prevention. Antimicrobial intervention may be useful with use of debridements ultimately reducing bioburden. Importance of x-ray imaging in chronic wounds cannot be understated even if imaging does not appear to be indicated. Finally, conversations with general practitioners may become standard practice for the podiatric physician in prescribing calcium-solubilizing drugs. While complete surgical debridement may not be feasible, early medical management may preclude progression of these intricate ulcerations.