Combination of Microfocused Ultrasound with Visualization and Dilute Calcium Hydroxylapatite Filler for Moderate to Severe Knee Skin Laxity.

BACKGROUND

Microfocused ultrasound with visualization (MFU-V) and calcium hydroxylapatite (CaHA) filler are modalities for improving skin laxity. Their use in combination on body sites other than the face is expanding.

OBJECTIVE

To investigate the effectiveness and safety of combination MFU-V and dilute CaHA (dCaHA) for lower anterior thigh and knee laxity over 12 and 24 weeks.

METHODS

Twenty women (40-71 years) with moderate to severe laxity of the anterior thigh and knee were enrolled in this split-body trial. Subjects received dual-depth (3.0mm, 1.5mm) or triple-depth MFU-V (4.5mm, 3.0mm, 1.5mm) to the inferior anterior thigh (127-381 lines) along with dCaHA (1:1 normal saline) injection (0.5-3mL). Clinical effectiveness was monitored using photography, qualitative clinician and subject assessments, and quantitative analysis of skin topography by three-dimensional imaging and dermal thickness by optical coherence tomography.

RESULTS

At 12 and 24 weeks, the treated thigh and knee experienced significant improvement in qualitative clinician scales (<0.01), with subjective improvement on photography and subject-reported assessments; no significant changes were noted by quantitative measures. Adverse events were reported in 68 percent of patients, including mild bruising (n=12) and swelling (n=10).

CONCLUSION

Combining MFU-V and dCaHA is safe and results in clinical improvement of anterior thigh and knee laxity.