Measurement of morphological and physiological skin properties in aged care residents: a test–retest reliability pilot study

This test–retest pilot study investigated the intra‐rater reliability and reproducibility of non‐invasive technologies to objectively quantify morphological (colour, thickness and elasticity) and physiological (transepidermal water loss (TEWL), hydration, sebum and pH) skin properties in an aged care population. Three consecutive measurements were taken from five anatomical skin sites, with the mean of each measurement calculated. The intra‐class correlation coefficient (ICC) and the standard error of measurement (SEM) were used to examine the intra‐rater reliability and reproducibility of measurements. Non‐invasive technologies in this study showed almost perfect reliability for ultrasound measurements of the subepidermal low echogenicity band (SLEB) (ρ = 0·95–0·99) and skin thickness (ρ = 0·95–0·99) across all sites. The ICC was substantial to almost perfect for pH (ρ = 0·76–0·88) and viscoelasticity (ρ = 0·67–0·91) across all sites. Hydration (ρ = 0·53–0·85) and skin retraction (ρ = 0·57–0·99) measurements ranged from moderate to almost perfect across all sites. TEWL and elasticity were substantial to almost perfect across four sites. Casual sebum levels and most colour parameters showed poor ICC. The use of non‐invasive technologies in this study provided an objective and reliable means for quantifying ageing skin and may offer future studies a valuable option for assessing skin tear risk.     

Crosstalk among adipose tissue,vitamin D level,and biomechanical properties of hypertrophic burn scars

PurposeThis cross-sectional study aimed to investigate whether adipose tissue loss and reduced vitamin D levels following severe burn injury are associated with pathologic scar formation and biomechanical scar properties.MethodsA total of 492 male subjects with hypertrophic burn scars were enrolled from January 2014 to July 2018 and analyzed. Body fat content was measured using dual-energy X-ray absorptiometry. Values of melanin, erythema, and trans-epidermal water loss (TEWL) and the distensibility and elasticity of hypertrophic scars were examined using pigment- and TEWL-measuring devices and a suction skin elasticity meter.ResultsBurn patients with higher fat percentage tended to have higher 25(OH) vitamin D levels (P < 0.001). As body fat percentage increased, hypertrophic scars showed higher mean value of Uf (distensibility, P < 0.001) and lower mean value of Uv/Ue (viscoelasticity or interstitial fluid shifting, P < 0.001). Burn patients with higher 25(OH) vitamin D levels tended to have higher mean values of Uf (P < 0.001) and Ua/Uf (gross elasticity, P = 0.013) and lower mean value of Uv/Ue (P = 0.008).ConclusionAdipose tissue loss and decreased 25(OH) vitamin D levels following burn injury were related to scar rigidity and slow interstitial fluid shifting in hypertrophic scars.     

Ultrasound assessed thickness of burn scars in association with laser Doppler imaging determined depth of burns in paediatric patients

This study describes the ultrasound assessment of burn scars in paediatric patients and the association of these scar thickness with laser Doppler imaging (LDI) determined burn depth. A total of 60 ultrasound scar assessments were conducted on 33 scars from 21 paediatric burn patients at 3, 6 and 9 months after-burn. The mean of peak scar thickness was 0.39 ± 0.032 cm, with the thickest at 6 months (0.40 ± 0.036 cm). There were 17 scald burn scars (0.34 ± 0.045 cm), 4 contact burn scars (0.61 ± 0.092 cm), and 10 flame burn scars (0.42 ± 0.058 cm). Each group of scars followed normal distributions. Twenty-three scars had original burns successfully scanned by LDI and various depths of burns were presented by different colours according to blood perfusion units (PU), with dark blue <125, light blue 125–250, and green 250–440 PU. The thickness of these scars was significantly different between the predominant colours of burns, with the thinnest scars for green coloured burns and the thickest for dark blue coloured burns. Within light blue burns, grafted burns healed with significantly thinner scars than non-grafted burns. This study indicates that LDI can be used for predicting the risk of hypertrophic scarring and for guiding burn care. To our knowledge, this is the first study to correlate the thickness of burns scars by ultrasound scan with burn depth determined by LDI.     

The use of AlloDerm on major burn patients: AlloDerm prevents post-burn joint contracture

In efforts to prevent and reduce joint contracture and scar formation after burn, we used the acellular human dermis (AlloDerm^®) as a dermal replacement in the acute stage. A total of 64 patients received AlloDerm^® graft selectively on joint areas during the study period from March, 2005 to July, 2007. From January to March, 2008, a total of 31 patients returned to our burn center to examine the functional results by measuring range of motion of joints. Additionally, the quality of grafted skin condition criteria of skin elasticity, scar thickness, trans-epidermal water loss, melanin and erythema level was measured in a total of 11 patients among them. By analyzing the limitation level of 55 joints excluding hand areas, we found that 24 joints (43.6%) showed no limitations, 12 joints (21.8%) showed limitations below 10%, 16 joints (29.1%) showed limitations between 10 and 19% and 3 joints (5.5%) showed limitations over 20%. The scar thickness of non-AlloDerm applied areas was 2.5 ± 0.9 mm and AlloDerm applied areas was 1.8 ± 0.7 mm (p = 0.396). Trans-epidermal water loss for non-AlloDerm applied areas was 20.9 ± 7.7 g/h/m² and AlloDerm applied areas was 10.8 ± 3.4 g/h/m² (p < 0.001). Erythema value for non-AlloDerm applied areas was 436.1 ± 65.8, whereas AlloDerm applied area was 394.4 ± 61.2 (p < 0.001). Acellular dermal matrix is a good option for treating major burns to prevent scar formation after burn and loss of joint function.     

Dermal substitution with Matriderm in burns on the dorsum of the hand

Background

Dermal substitutes are used increasingly in deep partial and full-thickness burn wounds in order to enhance elasticity and pliability. In particular, the dorsum of the hand is an area requiring extraordinary mobility for full range of motion. The aim of this comparative study was to evaluate intra-individual outcomes among patients with full-thickness burns of the dorsum of both hands. One hand was treated with split-thickness skin grafts (STSG) alone, and the other with the dermal substitute Matriderm^® and split-thickness skin grafts.

Material and Methods

In this study 36 burn wounds of the complete dorsum of both hands in 18 patients with severe burns (age 45.1 ± 17.4 years, 43.8 ± 11.8% TBSA) were treated with the simultaneous application of Matriderm^®, a bovine based collagen I, III, V and elastin-hydrolysate based dermal substitute, and split-thickness skin grafting (STSG) in the form of sheets on one hand, and STSG in the form of sheets alone on the other hand. The study was designed as a prospective comparative study. Using both objective and subjective assessments, data were collected at one week and 6 months after surgery. The following parameters were included: After one week all wounds were assessed for autograft survival. Skin quality was measured 6 months postoperatively using the Vancouver Burn Skin Score (VBSS). Range of motion was measured by Finger-Tip-Palmar-Crease-Distance (FPD) and Finger-Nail-Table-Distance (FNTD).

Results

Autograft survival was not altered by simultaneous application of the dermal matrix (p > 0.05). The VBSS demonstrated a significant increase in skin quality in the group with dermal substitutes (p = 0.02) compared to the control group with non-substituted wounds. Range of motion was significantly improved in the group treated with the dermal substitute (p = 0.04).

Conclusion

From our results it can be concluded that simultaneous use of Matriderm^® and STSG is safe and feasible, leading to significantly better results in respect to skin quality of the dorsum of the hand and range of motion of the fingers. Skin elasticity was significantly improved by the collagen/elastin dermal substitute in combination with sheet-autografts.     

Non-invasive and reliable assessment of compartment elasticity by pressure related ultrasound: An in-vitro study

PurposeThe development of acute compartment syndrome is a serious threat to trauma patients. The clinical assessment alone is not reliable enough to determine the need for fasciotomy in many cases. The Physician´s assessment of the elasticity of the muscle compartment might be particularly important to objectively evaluate the pressure in this enclosed space. The purpose of this study was to determine the observer´s reproducibility, of compartment elasticity measurements by a novel ultrasonic approach.MethodsIncreasing intra-compartmental pressures (ICP) were simulated in a water filled in-vitro model. Pressure related ultrasound was used to determine the relative elasticity (RE) of soft tissue compartments. A pressure transducing probe head was combined with the ultrasonic probe to obtain cross section views of the simulated compartment and to detect the amount of applied pressure by the observer. In this model, the compartment depth without compression (P₀) was set to be 100%. Changes of the compartment depth due to a probe pressure of 80 mmHg (P₈₀) were correlated to P₀ and an elasticity quotient as a value for RE (%) was calculated. Twelve blinded observers performed measurements for RE determination (%) under three pressure conditions. Reproducibility was calculated using intraclass correlation coefficient (ICC).ResultsMeasurements (n = 432) revealed that the RE (%) in the control group was 17,06% (SD+/-2,13), whereas the RE of the group ICP₃₀ significantly decreased to 12,66% (SD+/- 1,19) (p<0,001). The ICP₅₀ group revealed a further significant decrease to 8,43% (SD+/- 0,67) (p<0,001). Repeated measurement of RE and ICP showed a high level of correlation (spearman correlation coefficient: roh=0,922). A RE <14% resulted in a sensitivity of 96% and a specificity of 90,3% for diagnosis of an ICP >30 mmHg. ICC_inter was 0,986; 95%, CI: 0,977–0,992 (p<0,001).DiscussionThe presented ultrasound-based approach reliably assesses the elasticity in a simulated compartment model. In this pioneer study investigating the inter- and intra-observer reproducibility, this method of measurement appears to be of low cost in addition to being an easy and secure approach that may have the potential to substitute invasive measurement. Further investigations are required to improve its feasibility and to confirm the reliability under clinical conditions.     

Sex differences in the skin microbiome of burn scars

Sex differences are observed in various spectrums of skin diseases, and there are differences in wound healing rate. Herein, sex differences were identified for the newly healed skin microbiome of burn patients. Fifty-two skin samples (26 normal skin, 26 burn scars) were collected from 26 burn patients (12 male, 14 female) and microbiota analysis was performed. The correlation between skin microbiota and biomechanical properties of burn scars was also investigated. There were no significant differences in clinical characteristics between male and female patients. Considering the biomechanical properties of burn scars and normal skin around it performed before sample collection, the mean erythema level of men's normal skin was significantly higher than that of women, whereas the mean levels of melanin, transepidermal water loss and skin hydration showed no significant sex differences. The erythrocyte sedimentation rate was significantly higher in females than that in males. Alpha diversity showed no significant differences between normal skin and burn scars in the male group. However, the scar was significantly higher than that of normal skin in the female group. Microbial network analysis revealed that the male group had more complex microbial network than the female group. Additionally, in the male group, the edge density and clustering coefficient were higher in burn scars when compared to normal skin, than the female group. There were sex differences in the results of microbiome of normal skin and burn scars. Some of the altered microbiota have been correlated with the biomechanical properties of burn scars. In conclusion, sex difference in the burn scar microbiome was confirmed. These results suggest that burn treatment strategies should vary with sex.     

A pilot evaluation study of high resolution digital thermal imaging in the assessment of burn depth

Thermal imaging is a tool that can be used to determine burn depth. We have revisited the use of this technology in the assessment of burns and aim to establish if high resolution, real-time technology can be practically used in conjunction with clinical examination to determine burn depth. 11 patients with burns affecting upper and lower limbs and the anterior and posterior trunk were included in this study. Digital and thermal images were recorded at between 42 h and 5 days post burn. When compared to skin temperature, full thickness burns were significantly cooler (p < 0.001), as were deep partial thickness burns (p < 0.05). Superficial partial thickness burns were not significantly different in temperature than non-burnt skin (p > 0.05). Typically, full thickness burns were 2.3 °C cooler than non-burnt skin; deep partial thickness burns were 1.2 °C cooler than non-burnt skin; whilst superficial burns were only 0.1 °C cooler. Thermal imaging can correctly determine difference in burn depth. The thermal camera produces images of high resolution and is quick and easy to use.     

The effect of burn rehabilitation massage therapy on hypertrophic scar after burn: A randomized controlled trial

ObjectiveTo evaluate the effect of burn rehabilitation massage therapy on hypertrophic scar after burn.MethodOne hundred and forty-six burn patients with hypertrophic scar(s) were randomly divided into an experimental group and a control group. All patients received standard rehabilitation therapy for hypertrophic scars and 76 patients (massage group) additionally received burn scar rehabilitation massage therapy. Both before and after the treatment, we determined the scores of visual analog scale (VAS) and itching scale and assessed the scar characteristics of thickness, melanin, erythema, transepidermal water loss (TEWL), sebum, and elasticity by using ultrasonography, Mexameter^®, Tewameter^®, Sebumeter^®, and Cutometer^®, respectively.ResultsThe scores of both VAS and itching scale decreased significantly in both groups, indicating a significant intragroup difference. With regard to the scar characteristics, the massage group showed a significant decrease after treatment in scar thickness, melanin, erythema, TEWL and a significant intergroup difference. In terms of scar elasticity, a significant intergroup difference was noted in immediate distension and gross skin elasticity, while the massage group significant improvement in skin distensibility, immediate distension, immediate retraction, and delayed distension.ConclusionOur results suggest that burn rehabilitation massage therapy is effective in improving pain, pruritus, and scar characteristics in hypertrophic scars after burn.     

Predictors of re-epithelialization in pediatric burn

Introduction

An important treatment goal for burn wounds is to promote early wound closure. This study identifies factors associated with delayed re-epithelialization following pediatric burn.

Methods

Data were collected from August 2011 to August 2012, at a pediatric tertiary burn center. A total of 106 burn wounds were analyzed from 77 participants aged 4–12 years. Percentage of wound re-epithelialization at each dressing change was calculated using Visitrak™. Mixed effect regression analysis was performed to identify the demographic factors, wound and clinical characteristics associated with delayed re-epithelialization.

Results

Burn depth determined by laser Doppler imaging, ethnicity, pain scores, total body surface area (TBSA), mechanism of injury and days taken to present to the burn center were significant predictors of delayed re-epithelialization, accounting for 69% of variance. Flame burns delayed re-epithelialization by 39% compared to all other mechanisms (p = 0.003). When initial presentation to the burn center was on day 5, burns took an average of 42% longer to re-epithelialize, compared to those who presented on day 2 post burn (p < 0.000). Re-epithelialization was delayed by 14% when pain scores were reported as 10 (on the FPS-R), compared to 4 on the first dressing change (p = 0.015) for children who did not receive specialized preparation/distraction intervention. A larger TBSA was also a predictor of delayed re-epithelialization (p = 0.030). Darker skin complexion re-epithelialized 25% faster than lighter skin complexion (p = 0.001).

Conclusions

Burn depth, mechanism of injury and TBSA are always considered when developing the treatment and surgical management plan for patients with burns. This study identifies other factors influencing re-epithelialization, which can be controlled by the treating team, such as effective pain management and rapid referral to a specialized burn center, to achieve optimal outcomes.     

A study of the cutaneous sensory reinnervation after burn injury using antibodies to neurofilament

Summary The reinnervation of neurofilament-positive sensory nerve fibers in human skin after burn injury was investigated using an indirect immunohistochemical technique. In superficial burns, which healed spontaneously, a dense innervation pattern of neurofilament positive fibers were seen after 3–5 weeks. After 1–2 years the innervation pattern resembled that of normal nonburned skin. In deep burns, subjected to early or late excision and skingrafting, neurofilament positive fibers were seen in the dermis after 3–5 weeks and after 1–2 years a less dense innervation was observed, compared to non-burned skin. In these patients fibers were often seen running in parallel to the dermis-epidermis boundary with only a few fibers entering the epidermal layer. In deep burns that healed with hypertrophic scars only sparse neurofilament positive fibers were encountered 1–2 years after the injury.     

Effect of extracorporeal shock wave therapy for burn scar regeneration: A prospective,randomized, double-blinded study

PurposeThis study aimed to investigate the regeneration effect of extracorporeal shock wave therapy (ESWT) on hypertrophic scar regeneration using objective measurements.MethodsThis was a double-blinded, randomized, controlled trial of 48 participants who had undergone autologous split-thickness skin grafting (STSG) with same artificial dermis. The ESWT group (n = 25) received shock waves with low-energy flux density (0.05–0.30 mJ/mm²). The interval between treatments is a 1-week. The ESWT group also received recommended treatment. The control group (n = 23) only received standard treatment. We measured skin characteristics before treatment and after 6 weeks for both groups.ResultsNo significant intergroup difference was noted at the initial evaluations (p > 0.05). The pre- to post-treatment change in the scar thickness (p = 0.03) and erythema (p = 0.03), greater reduction was found in the ESWT group than control group. The pre- to post-treatment change in the sebum level (p = 0.02), more increase was found in the ESWT group. We found no significant differences in the change measurements between the two groups for melanin levels (p = 0.62) and transepidermal water loss (TEWL) (p = 0.94). The changes (skin distensibility, biological skin elasticity, gross skin elasticity, and skin viscoelasticity) measured with the Cutometer showed no significant differences between the two groups (p = 0.87, p = 0.32, p = 0.37, and p = 0.29, respectively).ConclusionThis is the first report of ESWT on hypertrophic scar after burn using objective tools (melanin, erythema, sebum, TEWL, elasticity and thickness). ESWT has objective beneficial effects on burn-associated scar characteristics.     

Wound healing at adaptation zones of skin flaps harvested from acute burned skin

Background

Early reconstruction of burn defects culminates in more successful results. The wound healing process of the burned skin affects not only the curative phase of the burned area but also result of any reconstructive procedure including the regional flaps. Thus, in this study, we have evaluated the wound healing process at the distal incisions of random-pattern skin flaps prepared from burned dorsal skin of rats.

Materials and methods

Thermal burn damage was performed with dimensions of 3 cm × 3 cm on Wistar albino rats. In group 1 (n = 12), no burn was produced and 3 cm × 3 cm caudally based, random-pattern skin flaps were elevated. In group 2 (n = 12), a 5 cm × 5 cm area of partial-thickness thermal damage was produced and after three days a 3 cm × 3 cm random-pattern skin flap was elevated as in group 1 inside the burned skin site. In group 3 (n = 12), 3 cm × 3 cm area of partial-thickness thermal damage was produced and after three days 3 cm × 3 cm random-pattern skin flap was elevated. In group 4 (n = 12), 3 cm × 3 cm area of partial-thickness thermal damage was produced and after three days a 3 cm × 3 cm random-pattern skin flap was elevated at the distal margin of the burned area. The flaps were adapted to the donor sites in all groups. The histopathological evaluation was done and hydroxyproline levels were measured.

Results

There were no significant differences between groups regarding presence of epithelialization, myofibroblast numbers, and collagen texture (p > 0.05). Neovascularization level was significantly higher in group 2 than the other groups (p < 0.05). There were no statistically significant difference among the hydroxyproline levels in all four groups (p > 0.05).

Conclusion

The preference of the incision site in a burn zone while designing a flap during the acute burn period was proposed to possess no difference in terms of wound healing in an animal model.     

An effective procedure for skin stiffness measurement to improve Paediatric Burn Care

BackgroundThe objective evaluation of scar quality plays a crucial role in improving burn surgery and scar rehabilitation. Suction-based skin measurements were proposed as a method to objectively determine the mechanical properties of scars, yet their use is limited, in particular for paediatric burn care. A new device was developed which provides essential advantages for scar assessment. The aim of this study was to assess its reliability, intra- and interobserver variability.MethodsThe new device, “Nimble”, consists of a lightweight probe that measures the negative pressure needed to obtain a predefined tissue elevation, revealing information on the stiffness of the tissue. 29 former paediatric burn patients were included. Three observers measured the tissue stiffness of a predefined location on the scar and on healthy skin using the Nimble, and the established suction device, the Cutometer^®. The reliability of both instruments in distinguishing between healthy skin and scar was assessed by means of the intraclass correlation coefficient.ResultsThe Nimble successfully differentiated between scar tissue and healthy skin in 92%, the Cutometer in 80% of the patients (p < 0.05). Inter- and intraobserver variability of the Nimble (ICCs) were excellent. For the majority of the calculated ICC values the Nimble exceeded the Cutometer^®.ConclusionThe new device enables reliable and safe measurement of the stiffness of scars. Measurements are less susceptible to patient non-compliance and observer dependency. The Nimble might therefore constitute an easy to use tool for the systematic assessment of scars, thus supporting decision-making in paediatric burn care.     

Hypoalbuminemia in the first 24 h of admission is associated with organ dysfunction in burned patients

Objective

Hypoalbuminemia is a common finding in burned patients, but its association with increased morbidity and mortality has not been well established. We assessed whether hypoalbuminemia in the first 24 h of admission is associated with organ dysfunction in patients with severe burns.

Methods

For a two year period (2008–2009), we reviewed the records of burn adult patients with a total body surface area 20% admitted in our unit within the first 24 h of injury. A multiple linear regression analysis was conducted to assess hypoalbuminemia as an independent predictor of organ dysfunction.

Results

56 subjects were analyzed. Multiple linear regression analysis showed that hypoalbuminemia in the first 24 h of admission was an independent predictor of organ dysfunction. Serum albumin concentration ≤30 g/L was associated with a two-fold increase in organ dysfunction [SOFA scores at day 0 (p = 0.005), day 1 (p = 0.005) and first week mean values (p = 0.004)], but not with mortality (p = 0.061).

Conclusion

Hypoalbuminemia is associated with organ dysfunction in burned patients. Unlike unmodifiable predictors such as age, burn surface and inhalation burn, correction of hypoalbuminemia might represent a goal for a future trial in burn patients.     

Estimating severity of burn in children: Pediatric Risk of Mortality (PRISM) score versus Abbreviated Burn Severity Index (ABSI)

Objective

The purpose of our study is to validate the Pediatric Risk of Mortality (PRISM) score and compare the accuracy of PRISM predicted outcomes to the Abbreviated Burn Severity Index (ABSI). We hypothesized that the PRISM score is more accurate in predicting mortality and hospital length of stay than the ABSI in children with severe burns.

Methods

All children <18 years of age admitted to a regional pediatric burn center between January 1, 2008 and July 1, 2010 were reviewed. Those with a Total Body Surface Area (TBSA) burn ≥20% who were admitted within 7 days of injury were selected for our study. Measured parameters included: demographics, burn characteristics, PRISM and ABSI scores at admission, and outcomes (mortality, hospital length of stay (LOS), ventilator days and cause of death).

Results

A total of 83 patients met criteria and had complete data sets. The mean age (±SEM) was 8.0 ± 0.6 years, mean % TBSA burn 49.9 ± 2.1%, 62.7% were male, and 45.8% had inhalation injury. Hospital LOS was 74.4 ± 7.9 days, with 31.5 ± 4.9 ventilator days. Mean PRISM score ranged from 14.2 to 16.0, with ABSI scores 7.9 to 8.5. Actual overall mortality was 18.1% compared to a PRISM predicted mortality of 19.8 ± 2.5% (p < 0.001, r = 0.570). ABSI predicted mortality varied from 10 to 20% for a score of 7.9 to 30–50% for a score of 8.5. Logistic regression showed that both PRISM (p < 0.001) and ABSI (p < 0.001) mortality predictions accurately estimated actual mortality, which remained true in a combined model. ABSI was predictive of hospital LOS (p < 0.001) and ventilator days (p < 0.001) while PRISM was not (p = 0.326 and p = 0.863).

Conclusions

Both PRISM and ABSI scores are predictive of mortality in severely burned children. Only ABSI correlates with hospital length of stay and ventilator days, and thus may also be more useful in predicting ICU resource utilization.     

Repositioning of the humeral tuberosities can be guided by pectoralis major insertion

In complex proximal humerus fractures, positioning of the tuberosities can be a challenge. This study demonstrates the constant angle between the pectoralis major (PM) and the medial lip of the bicipital groove (BG) on the horizontal axial plane. This angle can be used to determine the rotation, as well as the positioning of the tuberosities, when planning a hemiarthroplasty or a reconstruction. Thirty-one shoulder MRIs were reviewed by three independent observers. The measurements were taken by superposing the axial cut of the proximal humerus, at the level of the distal bicipital groove, and the cut at the top of the PM insertion. By aligning the centers of rotation, we could determine the arcs of rotation between the insertion of the PM and the lips of the medial and lateral bicipital groove (MBG and LBG). Both angles were compared in terms of reliability, reproducibility, and precision. The mean PM–MBG angle was 3.7° [standard deviation (SD) 14.7°] and 27.4° (SD 14.4°) for the PM–LBG angle. We obtained good and very good intra-class correlation coefficient (ICC) results for inter- (0.675) and intra-observer (0.793) reliabilities on the medial angle, plus excellent results for the lateral angle (inter-observers 0.962 and intra-observer 0.895). This study demonstrates that the repositioning of humeral tuberosities can be guided by pectoralis major insertion. This will help achieve proper positioning of the metaphysis in relation to the diaphysis during surgery for complex proximal humerus fractures.     

Grip strength dynamometry: Reliability and validity for adults with upper limb burns

Background

Upper limb (UL) burns can result in significant loss of strength and physical function. The aim of this study was to establish the reliability and validity of grip strength dynamometry (GSD) for measuring burn-affected UL strength over time.

Methods

A retrospective sample of adult participants (n = 89) with UL burns was obtained from Royal Perth Hospital. Data were compiled from assessments conducted at discharge, one, three, six and 12 months afer burn. Within-session reliability and validity was examined through multivariable analyses.

Results

GSD demonstrated within-session reliability for all investigated timepoints (ICC's ≥ 0.87, p < 0.0005.) Criterion validity was confirmed with GSD and QuickDASH being significantly associated in both right (b = 0.17, p = 0.002) and left (b = 0.14, p = 0.002) hands. Construct validity was demonstrated through significant association of GSD values with location of burn (p < 0.35); time after burn (p < 0.012); surgical intervention (p = 0.003) and burn size (p < 0.05).

Conclusion

This study demonstrates that grip strength dynamometry is a reliable and valid outcome measure for measuring burn-affected UL strength from one month to one year after burn.     

Pentoxifylline modifies three-dimensional collagen lattice model contraction and expression of collagen types I and III by human fibroblasts derived from post-burn hypertrophic scars and from normal skin

Fibroblasts are thought to be partially responsible for the persisting contractile forces that result in burn contractures. Using a monolayer cell culture and fibroblast populated collagen lattice (FPCL) three-dimensional model we subjected hypertrophic scar and non-cicatricial fibroblasts to the antifibrogenic agent pentoxifylline (PTF – 1 mg/mL) in order to reduce proliferation, collagen types I and III synthesis and model contraction. Fibroblasts were isolated from post-burn hypertrophic scars (HSHF) and non-scarred skin (NHF). Cells were grown in monolayers or incorporated into FPCL's and exposed to PTF. In monolayer, cell number proliferation was reduced (46.35% in HSHF group and 37.73% in NHF group, p < 0.0001). PTF selectively inhibited collagen III synthesis in the HSHF group while inhibition was more evident to type I collagen synthesis in the NHF group. PTF also reduced contraction in both (HSHF and NHF) FPCL.     

Measurement of the Knee Flexion Angle With a Smartphone-Application is Precise and Accurate

We hypothesized that the measurement of the knee flexion angle measured with a specific Smartphone application was different from the reference measurement with a navigation system designed for total knee arthroplasty (TKA). Ten consecutive patients operated on for navigation assisted TKA were selected. Six navigated and 6 Smartphone measurements of knee flexion angle were obtained for each patient. The paired difference between measurements and their correlation were analyzed. The mean paired difference between navigated and Smartphone measurements was − 1.1° ± 6.8° (n.s.). There was a significant correlation between both measurements. The coherence between both measurements was good. The intra-observer and inter-observer reproducibility were good. The Smartphone application used may be considered as precise and accurate. The accuracy may be higher than other conventional measurement techniques.