Calcium hydroxylapatite

Calcium hydroxylapatite (CaHA) has become the most commonly recommended filler for rejuvenation of the aging hand. First used for medical purposes in areas such as vocal fold and maxillofacial augmentation, CaHA (Radiesse^®, Merz Aesthetics) was approved by the US Food and Drug Administration (FDA) in 2006 both for volume restoration in patients with HIV-related lipoatrophy and for cosmetic correction of moderate to severe facial wrinkles and folds. Specific approval for hand rejuvenation was obtained in Canada in 2010, but remains an off-label usage in the USA.

As an opaque, white substance, CaHA has the advantage of acting as both a filler and camouflage for underlying anatomical architecture. However, its use for hand rejuvenation was initially limited by the product’s high viscosity and pain upon injection. In 2007, Busso & Applebaum reported a novel approach that overcame both issues. Utilizing a Luer-to-Luer lock connector (Fig. 22.1A), the authors mixed 0.1 mL 2% lidocaine without epinephrine with 1.3 mL of CaHA (the standard syringe volume at that time). After tenting the skin of the central dorsal hand to separate it from underlying large vessels and tendons, they injected a single bolus of 0.5–1.4 mL of the lidocaine–CaHA mixture into the space created between the subcutaneous layer and the superficial fascia. The bolus was then massaged and molded into a cosmetically smooth appearance. The addition of lidocaine reduced both the viscosity and pain.

Figure 22.1 Technique to mix calcium hydroxylapatite (CaHA) with anesthetic: 1.5 mL of 1% lidocaine without epinephrine in a Luer lock syringe, attached to a syringe containing 1.5 mL of CaHA via a disposable Luer-to-Luer lock connector and mixed.

Since this initial report, physicians have modified the technique by increasing the volume of lidocaine used for dilution (e.g. the 2009 study by Edelson). In 2010, Marmur et al published the first organized institutional review board-approved study of CaHA filler for hand rejuvenation. They mixed 2.0 mL of 2% lidocaine without epinephrine per 1.3 mL syringe of CaHA. A total of 0.3–1.0 mL of the product was injected interdigitally using a 25-gauge 1.5-inch (3.75 cm) needle at three to five insertion points, as opposed to a single bolus injection. They reported high patient satisfaction rates in five patients who each received a single treatment with follow-up extending to 24 weeks postoperatively. Although localized edema initially resolved in all patients by 1 week, one patient had recurrent edema at day 10 that persisted for 3 additional weeks and required oral corticosteroids.

Several larger studies by Busso et al, Bank, and Marmur et al have recently been published supporting the safety and efficacy of CaHA as an anti-aging hand filler. Busso et al published a multicenter, randomized, controlled trial of 101 patients followed over 6 months and established a new hand volume severity scale 3 to assess results (Table 22.1). Following administration of a lidocaine bolus preoperatively, CaHA was administered as a bolus into the dorsal hand using a 27-gauge 0.75-inch (20 mm) needle. Aside from reporting statistically significant improvement in the treatment group, the study also found that adverse events, including bruising, itching, pain, redness, and swelling (Fig. 22.2), were frequent yet short in duration and did not affect overall patient function significantly. Similarly, Sadick noted only brief and minor side effects in 10 patients following CaHA treatment with a 25-gauge 0.5-inch (12 mm) needle to the dorsal hands and residual cosmetic correction lasting up to 1 year postoperatively.

Table 22.1 Busso hand volumizing severity scale