Residual limb health is critical for continued prosthesis use; however, many prosthesis users experience skin‐related breakdown. The interface between the residual limb and the prosthetic socket sets the local mechanical environment and plays a role in skin stresses. Motion of the residual limb in the socket adds additional mechanical strain on the limb. This article explores the relationship between motion of the limb in the socket and residual limb health. We evaluated current methods for assessing residual limb health and motion of the residual limb in the socket and compared these evaluations across different prosthetic suspension systems. While few direct studies comparing residual limb health and motion exist, it has been shown that elevated vacuum suspension systems result in both improved residual limb health compared to passive suction and pin‐lock systems and decreased motion compared to passive suction, pin‐lock, knee sleeve, and anatomical suspension systems. While motion and health have not been directly linked, elevated vacuum suspension may demonstrate a relationship that reduced motion of the residual limb in the socket improves residual limb health. Further evaluation in this area is necessary to more completely and directly understand the relationship between residual limb motion and residual limb health.

The success of cultured epithelial autografts (CEAs) in treating large surface area burns is limited by their fragility and poor adhesion to the wound bed. Rete ridges, interdigitations at the dermal-epidermal junction, are stem cell niches critical to dermal-epidermal adhesion and distribution of mechanical forces within the skin, but are slow to develop in CEA-treated burn wounds. A porcine burn-excise-autograft model was used to investigate the efficacy of an allogeneic dermal template (DT), seeded with fibroblasts and laser micropatterned to have dermal papillae-like topography, in improving outcomes with CEA. Autologous CEAs were applied to full-thickness wounds alone or with DTs that were flat (CEA+Flat) or micropatterned (CEA+Ridged). The use of a DT improved graft handleability and integration at the wound margins, and restored epidermal barrier function two weeks faster than CEAs alone. In CEA+Ridged grafts, increases in keratinocyte proliferation and basement membrane deposition were observed at 2 weeks post-grafting. Rete ridges were only present in CEA+Ridged grafts at week 2, and developed less frequently and shallower in CEA and CEA+Flat grafts over the course of the study. These results suggest that laser micropatterned DTs are suitable for co-transplantation with CEAs and can significantly improve graft adhesion and development.

In persons with limb loss, prosthetic devices cause skin breakdown, largely because residual limb skin (nonvolar) is not intended to bear weight such as palmoplantar (volar) skin. Before evaluation of treatment efficacy to improve skin resiliency, efforts are needed to establish normative data and assess outcome metric reliability. The purpose of this study was to use optical coherence tomography to (i) characterize volar and nonvolar skin epidermal thickness and (ii) examine the reliability of optical coherence tomography. Four orientations of optical coherence tomography images were collected on 33 volunteers (6 with limb loss) at 2 time points, and the epidermis was traced to quantify thickness by 3 evaluators. Epidermal thickness was greater (P < .01) for volar skin (palm) (265.1 ± 50.9 μm, n = 33) than for both nonvolar locations: posterior thigh (89.8 ± 18.1 μm, n = 27) or residual limb (93.4 ± 27.4 μm, n = 6). The inter-rater intraclass correlation coefficient was high for volar skin (0.887–0.956) but low for nonvolar skin (thigh: 0.292–0.391, residual limb: 0.211–0.580). Correlation improved when comparing only 2 evaluators who used the same display technique (palm: 0.827–0.940, thigh: 0.633–0.877, residual limb: 0.213–0.952). Despite poor inter-rater agreement for nonvolar skin, perhaps due to challenges in identifying the dermal–epidermal junction, this study helps to support the utility of optical coherence tomography to distinguish volar from nonvolar skin.

Scarring remains problematic post-burn injury even with pressure garment therapy, the current standard of care for scar suppression. Unfortunately, there is no consensus regarding the minimum pressure magnitude required for efficacy. Thus, to fill this knowledge gap, the relationship between the magnitude of applied pressure and scar outcomes was assessed using a porcine burn-excise-autograft model. Scars were treated with adjustable, low-fatigue pressure garments fit to 10, 20, or 30 mmHg; control scars were untreated (n = 16/group). Scar contraction, thickness, histological appearance, and biomechanics were assessed, and garment fatigue was measured. At all magnitudes of applied pressure, use of garments significantly reduced scar contraction and thickness, and improved scar pliability and elasticity, versus controls. Utilizing adjustable, low-fatigue garments, pressures of 10, 20, and 30 mmHg were reliably maintained throughout the study, demonstrating the efficacy of pressure garment therapy at pressures as low as 10 mmHg. While 30 mmHg pressure garments significantly reduced contraction compared to 10 or 20 mmHg, these garments required greater adjustment of the garment to reach the target pressure, which in practice could necessitate more frequent garment replacement. The results showed that although greatest improvement was observed at 30 mmHg, pressure as low as 10 mm Hg is effective at reducing post-burn scarring if that pressure is maintained throughout the garment’s use.

The skin’s physiological response to repetitive stress is not well understood in prosthesis users. Improving this understanding could facilitate the design of a diagnostic tool to determine if the skin is adapting to tolerate stress from a prosthetic socket. The objective of this research was to develop a physical system that mechanically stresses the skin in a controlled manner and then implements the imaging modalities of infrared (IR) imaging and optical coherence tomography (OCT). IR imaging characterizes the skin’s temperature response, while OCT characterizes vessel diameter changes over time in the skin. The system was implemented in a single individual with a transtibial amputation. The system reliably maintained the force profile throughout testing. IR and OCT imaging were initiated after load application, and all curves demonstrated an initial rise in temperature immediately after load removal followed by a decrease towards baseline. The system was able to effectively detect a peak outcome (temperature and vessel area) with both imaging modalities. The system’s ability to maintain the loading throughout and begin imaging to capture the peak provides promise for expanded use to better understand the skin’s physiological response to loading in prosthesis users. This improved understanding may better inform treatment strategies to optimize patient outcomes.

Skin breakdown occurs commonly within patients with lower-limb prostheses where the current clinical practice to diagnose skin breakdown is visual inspection by a clinician. Thermal imaging and optical coherence tomography angiography (OCT-A) have been proposed as early detection methods for skin breakdown and hold great promise. OCT-A is a noninvasive imaging modality that outputs a near-infrared optical signal and captures the reflective depth signal. The recorded transient behavior of the vessel area density (VAD), after repetitive dermal loading conditions, has been correlated to skin breakdown. Thermal imaging tracks the temperature profile of the skin surface after repetitive loading conditions and utilizes the temperature time-to-peak (TTP) as a metric of dermal health like VAD. Both methods are sensitive to imaging artifacts, and current resolutions are presented in this work, along with a discussion of the need to standardize data collection and advance image processing methods. Current approaches typically rely on thresholding that produces varying results based on user-selected limits followed by smoothing without any basis of the underlying physics. This review paper presents a need for a constitutive expression that captures the expected physics, thereby strengthening confidence in the use of either thermography or OCT-A, and enabling true clinical applications to aid patient health.