INTRODUCTION

The aging process takes place in all areas of the body, and one of the most affected areas with aging is the hands, where the visibility of the veins and tendons is consid- ered to be not aesthetically pleasing for many people.¹ Different fillers have been used for hand rejuvenation.² Calcium hydroxyapatite fillers are used for both volumization (if injected in a nondiluted state) or biostimulation (if it is hyper diluted).³ In its pure form, the gel carrier is maintained, but the gel disperses if it becomes diluted.^4,5

Several types of studies reported using either nondiluted or diluted CaHA filler for hand rejuvenation, but so far, no single study describes the use of both forms in the same session for hand rejuvenation. That is why it is necessary for the current study to evaluate the use of both formulas, giving both volumization for areas of atrophy and biostimulation for the skin quality.

MATERIALS

The study was comprised of 40 White female patients aged 45–57 years, complaining of the appearance of veins and tendons and loss of skin elasticity in their hands. Only patients with grade 4 according to the five-point hand grading scale⁶ were included in the study. The postoperative patient satisfaction score was recorded by asking the patient to report how satisfied they feel about the results of the treatment on a scale from 1 to 5:
1 = Not satisfied
2 = Less satisfied
3 = Quite satisfied
4 = Satisfied
5 = Very satisfied

Postoperative recording was performed at 14 days, 2 months, 4 months, and 6 months, using the same scoring grade.

CaHA filler was used. A single syringe was used for each patient at the baseline treatment, followed by another syringe at 2 months and another one at 4 months, so a total of three syringes were used for the whole treatment plan for each patient. A single point of entry was located 2 cm medial to the ulna border, where skin pinching was performed in step 1 and 2 only; then a 22 G 50-mm cannula was introduced. The injections were performed as follows:
Step1:Injecting 0.5mL of pure CaHA filler into the right hand
Step 2: Injecting 0.5 mL of pure CaHA filler into the left hand.
Step 3: The rest of the syringe was used as a soft diluted blend (0.5mL pure CaHA filler diluted with a 1.5mL saline), which was equally distributed in both hands.

The same protocol was repeated respectively at the 2 and 4 month follow-ups. All injections were performed in a series of linear retrograde and anterograde injections. The nondiluted CaHA filler was placed at the dorsal intermediate laminae, whereas the diluted product was placed at the dorsal superficial laminae.

RESULTS

None of the patients reported any serious complications after any of the procedures at all stages. All patients reported a high satisfaction score at the 14-day follow-up; however, this score decreased at the 2-month follow-up followed by a regain in the score at the 4 and 6 month follow-ups (Figs. 1 and 2). Statistical analysis for the recorded data were done as shown in Table 1 and Figure 3.

DISCUSSION

The goal of this study was to evaluate the combined use of nondiluted and diluted calcium hydroxyapatite filler as an antiaging treatment for hand rejuvenation. The nondiluted component will give a volumizing effect for the atrophic areas, whereas the diluted component will give a biostimulation for the skin quality by collagen and elastin induction. It is of paramount importance to understand that because the calcium hydroxyapatite spheres are maintained in both formulas, this will lead to a continuous boosting of the collagen and elastin with a high degree of local and global stimulation for the tissue layers. In our study, we were aiming for a double-layered treatment to provide a synergism in terms of biostimulation on different tissue layers. We also emphasize that all our patients were followed up to 6 months and showed good results up to this period and that we only evaluated patient satisfaction. However, further studies with longer follow-up periods and larger sample sizes with further investigations using different software for skin analysis will help with better assessment for our proposed technique.

CONCLUSIONS

The use of both nondiluted and diluted CaHA fillers for hand rejuvenation will offer not only a volumization effect for the areas of volume loss because of the nondiluted component, but will also help in increasing the skin thickness and improving the skin elasticity due to the diluted component, both of which will provide synergism in terms of collagen and elastin formation.

REFERENCES
1. Akubietz RG, Kloss DF, Gruenert JG, et al. The ageing hand. A study to evaluate the chronological ageing process of the hand. J Plast Reconstr Aesthet Surg. 2008;61:681–686.
2. Vleggaar D. Soft-tissue augmentation and the role of poly-L-lactic acid. Plast Reconstr Surg. 2006;118:46S–54S.
3. De Almeida AT, Figueredo V, da Cunha ALG, et al. Consensus recommendations for the use of hyperdiluted calcium hydroxy- apatite (Radiesse) as a face and body biostimulatory agent. Plast Reconstr Surg Glob Open. 2019;7:e2160.
4. Sundaram H, Voigts B, Beer K, et al. Comparison of the rheo- logical properties of viscosity and elasticity in two categories of soft tissue fillers: calcium hydroxylapatite and hyaluronic acid. Dermatol Surg. 2010;36:1859–1865.
5. Yutskovskaya YA, Kogan EA. Improved neocollagenesis and skin mechanical properties after injection of diluted calcium hydroxylapatite in the neck and de?colletage: a pilot study. J Drugs Dermatol. 2017;16:68–74.
6. Carruthers A, Carruthers J, Hardas B, et al. A validated hand grading scale. Dermatol Surg. 2008;34:S179–S183.