Other than the face, the ageing process is especially noticeable on the hands as they are continually exposed to external triggers of skin ageing, such as ultraviolet radiation. In addition, patients who undergo facial rejuvenation treatments notice a growing disparity between their rejuvenated face and hands. The loss of the subcutaneous tissue on the back of the hands in particular causes tendons to become increasingly visible and veins to become more prominent; this ultimately leads to an aesthetically undesirable ‘bony’ appearance of the hands. The calcium hydroxylapatite (CaHA)-based filler Radiesse® — characterised by its high viscosity and elasticity — can provide an immediately volumising effect in these situations. The lack of hygroscopic potential is also advantageous for hand augmentation. Previous studies of Radiesse® (also with an observation period of up to 1-year for augmentation of the hands) confirm the high efficiency and safety of this material. A number of studies on augmentation of the hands were also conducted. In the author’s experience, hand augmentation with CaHA is a safe and effective procedure, which can be used to achieve noticeable, immediate and lasting treatment results, and without significant downtime for patients.

The processes of ageing affect more than just the face; our hands in particular betray our age. This is because they frequently come into contact with harmful substances throughout life, and it is known than many of us will often forego sun protection here¹. As with the face, age-related changes occur in the epidermis, dermis and all lower layers. Superficial changes may appear as fine lines, roughness, solar lentigines, seborrhoeic and actinic keratoses, and telangiectasias. Sub-dermal ageing processes make the hands look increasingly ‘skeletonised’ ^{1, 2}. These changes will usually become visible from the fourth decade of life. This article primarily relates to the loss of volume from the back of the hands.

Firstly, a dominant fold develops in the fourth dorsal interdigital space and is surrounded by multiple small parallel folds¹. The loss of elasticity and, more importantly, the loss of volume in the tissue surrounding the veins, leads to the typical skeletonised appearance. As a result, transversal folds also develop in the third interdigital space, and dorsal ulnar-side wrist creases appear from the age of 40 years. In slim people, the extensor tendons are visible along the entire length of the retinaculum extensorum to each metacarpal head, which often concerns many patients who present for treatment. Histologically, disorganised collagen fibrils and elastotic degeneration are detectable. Reduced microcirculation and poorer lymphatic drainage have also been documented¹.

As in the face, volume deficits in the hand can be corrected using dermal fillers. The procedure is simple, safe, quick, and effective. Hyaluronic acid and calcium hydroxylapatite (CaHA)-based dermal fillers are used most often for this indication².

Properties of CaHA

The volume filler Radiesse® (Merz Aesthetics, San Mateo, CA) consists of synthetically produced CaHA microspheres between 25 and 45 μm in size (30%), which are embedded in a resorbable, viscoelastic sodium carboxymethylcellulose gel matrix (70%).

An immediate corrective effect is noticeable on implantation of the filler, as a result of augmentation by the gel matrix. An additional effect occurs in the dermis: the CaHA microspheres stimulate the formation of new collagen. This principle of neocollagenesis was confirmed in a canine model³. In one study, neocollagenesis was also histologically documented in a person following the injection of this filler⁴. Over time, the CaHA microspheres are slowly broken down and metabolised into calcium and phosphate ions through normal metabolic processes. Reports on the duration of the filler effect in the literature range from 10 to 14 months, and often exceed that of hyaluronic acid fillers⁵.

CaHA has been used for over 20 years in dentistry and surgery. Radiesse is approved by the US Food and Drug Administration (FDA) for the correction of moderate to severe facial wrinkles and folds, and the correction of lipoatrophy as a result of antiretroviral therapy in HIV patients. The efficacy and tolerability of the filler has been investigated in clinical studies in over 3000 patients. In fact, it is one of the best-documented dermal fillers^5–13. Note that the material is clearly distinguishable from surrounding structures in a CT scan (Figure 1), while not always identifiable in X-rays¹⁴.

CaHA for hand augmentation

Radiesse is more viscous and elastic than other biodegradable dermal fillers¹⁵. This makes CaHA particularly suitable for volume correction in the hands. The opaque quality of Radiesse® also means that it can be used to hide prominently protruding veins¹⁶. Homogeneous distribution with low injection pressure is advantageous in the hands. In addition, patients can easily help to ensure the success of treatment by keeping the fist clenched or sitting on their hands immediately after the treatment for a period of time (approximately 2 hours is usually advised).

Augmentation with CaHA was first described for the hands in 2007¹⁷. Since then, there have been at least five further publications which prove the safety and efficiency of the material. One study investigated the use of the filler in 101 patients⁶. After 3 and 4 months, 66% and 56% respectively showed an improvement by at least one point on a standardized scale for evaluating signs of ageing on the hands (Busso Hand Volume Severity Scale, BHVSS — Table 1). More than three quarters of patients were satisfied with the treatment, while among doctors this figure was over 85%. The treatment proved to be safe. Side-effects included temporary erythema, ecchymosis, and oedema, which healed within 2 weeks^{6–8, 16, 18}.

A further study was published which investigated the safety and efficacy of CaHA in this indication over an observation period of 1 year. The volume filler also proved safe in this case and provided lasting treatment results for 9–12 months¹⁹.

Treatment protocol

Before the start of any treatment session, it is advisable to determine the nature of the baseline status objectively using a validated scale^{10, 18}. The Merz scales (Table 2) are a modern and practical way of evaluating the loss of volume from the back of the hand¹⁹.

For increased patient comfort, CaHA can be mixed with lidocaine prior to injection. A 1.5 ml syringe is usually mixed with CaHA, with 0.26 ml of a 1% lidocaine solution. However, different mixing ratios are possible depending on the practitioner. In the author’s experience, Radiesse® implants and integrates particularly well at this location if a mixing ratio of 1 : 1 is used.

Injection method

The substance is injected into the back of the hand. Both distal (between the distal ends of the carpal bones) and proximal (over the carpal bones) access is possible.

After lifting the skin over the area to be injected, the material is placed between the subcutaneous layer and the superficial fascia in the so-called ‘tenting technique’. All interdigital spaces are treated successively in this way. Blunt cannulae (25 G, 50 mm) or sharp 27 G cannulae are most suitable for implantation in the author’s experience. Using a sharp needle, boluses are inserted at three to four injection points (each around 0.2–0.4 ml). The ease of this method makes it suitable for less experienced users also. With the blunt flexible cannula, CaHA can be administered using the ‘linear threading technique’ (three to four threads), starting from one injection point only, which is usually placed in the middle of the area overlying the carpal bones. A typical injection quantity for both methods is 1–1.5 ml per hand.

Immediately after the procedure, it is advisable to massage the material (moulding) in order to ensure an even distribution.

After treatment, cooling with ice or iced gloves (e.g. IceMask®; Liquid Ice CosMedicals AG, Switzerland) is recommended. Figure 2 shows a 77-year-old female patient before and immediately after the injection of Radiesse (1.5 ml CaHA mixed with 0.3 ml lidocaine for the back of each hand); the volume of the hands has increased significantly. Figure 3 shows that a clear improvement in the initial condition can be achieved with the volume filler, even where there is a marked volume deficiency.

As with every filler treatment, patients should be encouraged to avoid physical exercise and sun exposure until any injection-related side-effects such reddening or swelling have abated. It is advisable to schedule a follow‑up appointment with patients 2 weeks later in order to assess the cosmetic result. Similar recommendations are also found in the literature^{17, 20}.

For the treatment of photodamage, such as lentigines on the back of the hand for example, combination treatment with a non-ablative laser or intense pulsed light procedure and chemical peels for further patient satisfaction may be useful.

Conclusions

Hands, one of the ‘tell-tale’ signs of ageing, are often ignored. Looking at the typical features of ageing hands, such as volume loss, augmentation therapies that replenish the area with a dermal filler, for example, are an easy-to-perform tool, which achieve immediate results. For this purpose, the dermal filler CaHA, with its prominent volumising capacity, is an essential tool. The volumising effect is immediately visible. Side-effects such as pain, swelling or bruising are minimal and of short duration. CaHA is a dense and easy to mold filler, which wears well in the hands and provides an instant cushion replacement. Hand augmentation with CaHA is a safe and effective procedure, which can be used to correct age-related volume loss from the hands in a single treatment, and without significant side‑effects for patients.

Owing to its physiochemical properties and successful volumising effect, Radiesse is proving increasingly effective at offering the ideal treatment for this indication. This indication will become more and more important as women who undergo minimally-invasive facial procedures observe a growing discrepancy between their ‘young’ face and ageing hands, increasing the desire for equally younger-looking hands.