Development of a Three-Dimensional Hand Model Using Three-Dimensional Stereophotogrammetry: Assessment of Image Reproducibility

Virtual Incision Pattern Planning using Three-Dimensional Images for Optimization of Syndactyly Surgery

Syndactyly is a congenital condition characterized by fusion of the fingers. If not treated correctly during infancy, syndactyly may hinder the normal development of hand function. Many surgical techniques have been developed, with the main goal to create a functional hand with the smallest number of operative corrections. Therefore, exact preoperative planning of the reconstructive procedure is essential. An imaging method commonly used for preoperative planning is 3-dimensional (3D) surface imaging. The goal of this study was to implement the use of this technique in hand surgery, by designing a virtual planning tool for a desyndactylization procedure based on 3D hand images. A 3D image of a silicon syndactyly model was made on which the incision pattern was virtually designed. A surgical template of this pattern was printed, placed onto the silicon model and delineated. The accuracy of the transfer from the virtual delineation toward the real delineation was calculated, resulting in a mean difference of 0.82 mm. This first step indicates that by using 3D images, a virtual incision pattern can be created and transferred back onto the patient successfully in an easy and accurate way by using a template. Thereafter, 3D hand images of 3 syndactyly patients were made, and individual virtual incision patterns were created. Each pattern was transferred onto the patient by using a 3D printed template. The resulting incision pattern needed minor modifications by the surgeon before the surgery was performed. Further research and validation are necessary to develop the virtual planning of desyndactylization procedures.

Three-dimensional soft tissue analysis of the hand: a novel method to investigate effects of acromegaly

Background

Acral overgrowth is a highly common clinical sign in patients with active acromegaly. To what extent this overgrowth persists after long-term remission of acromegaly is largely unknown. Using the new imaging technique of three-dimensional (3D) stereophotogrammetry, it is possible to accurately investigate soft tissue changes of the hand. The aim of the recent study was to compare the 3D soft tissue characteristics of the hands of patients in long-term remission of acromegaly to those of a healthy pair matched control group.

Methods

A case-control study was performed at a tertiary referral center. Twelve patients in remission of acromegaly (58 % male, mean age 58.3 years, mean BMI 29.6 kg/m²) were compared to twelve age-, gender-, ethnicity-, and BMI-matched control subjects. Of each individual, 3D photographs of both hands were acquired and analyzed using a 3D computer software program.

Results

The patients in long-term remission of acromegaly have overgrowth of soft tissue of the hand compared to matched control subjects, with a larger length and width of the hand (p = 0.0025, p = 0.0017, respectively). Furthermore, the diameters measured at the proximal interphalangeal (PIP) joints of the individual fingers are larger in the acromegaly patients.

Conclusions

Significant soft tissue overgrowth of the hand persists in former acromegaly patients, even after long-term remission. Analysis of 3D hand photographs is an accurate and easy tool to evaluate the acral soft tissue patterns in acromegaly.

Level of Evidence: Level III, diagnostic study.