Utilising 3D-printed ex vivo biomimetics to improve open reduction and internal fixation (ORIF) simulation training for hand fractures.

Background: Surgery for hand trauma accounts for a significant proportion of the plastic surgery training curriculum. The aim of this article is to create a standardised simulation training module for hand fracture fixation on open reduction and internal fixation (ORIF) techniques for residents in order to create a standardised hand-training framework that universally hones their skill and prepares them for their first encounter in a clinical setting. Methods: A step-ladder approach training using three-dimensional (3D)-printed ex vivo hand biomimetics was employed on a cohort of 15 plastic surgery residents (n = 15). Assessment of skills using a score system (global rating scale) was performed in the beginning and the end of the module by hand experts in our unit. Results: The overall average score of the cohort pre- and post-assessment were 22.08/50 (44.16%) and 41.54/50 (83.08%) respectively. Significant (p < 0.01) difference of improvement of skills was noted on all trainees. All trainees confirmed that the simulated models provided in this module were akin to the patient scenario and noted that it helped them improve their skills with regards to ORIF techniques including improvement of their understanding of the 3D bone topography. Conclusion: We demonstrate a standardised simulation training framework that employs 3D-printed ex vivo hand biomimetics proven to improve the skills of residents and which paves the way to more universal, standardised and validated training across hand surgery. This is, to our knowledge, the first standardised method of simulated training on such hand-surgical cases.Level of Evidence: Not ratable.

Intra-medullary Cannulated Headless Compression Screw for Bone Graft Fixation in Metacarpal Fractures.

High energy metacarpal fracture presenting with critical bone loss requires bone graft and hardware stabilisation. Early bone grafting and rigid internal fixation allow expedited patient recovery. Plate fixation is the most described technique when an autologous bone graft is being used. In this report, we present an alternative technique to secure bone grafts to metacarpal shafts with intra-medullary headless compression screws (HCS). In the presented patient, significant bone defects of the fourth and fifth metacarpals were bridged using iliac crest cortico-cancellous bone grafts and fixed with HCS. This method of fixation allowed controlled early active mobilisation. Bone graft incorporation and excellent active range of motion were demonstrated. Level of Evidence: Level V (Therapeutic).

Utilisation of a 3D printed ex vivo flexor tendon model to improve surgical training.

BACKGROUND: Surgery for hand trauma accounts for a significant proportion of the plastic surgery trainee activity. The aim of this article is to create a standardised simulation training module for flexor tendon repair techniques for residents prior to their first encounter in the clinical setting. METHODS: A step-ladder approach flexor tendon repair training with four levels of difficulty was conducted using a three-dimensional (3D) printed anatomical simulation model and a silicone tendon rod on a cohort of 28 plastic surgery Senior House Officers (SHOs) of various stages in their training (n=28). Assessment of knowledge (online questionnaire) and practical skills using validated score systems (global rating scale and task specific score) was performed at the beginning and end of the module by hand experts of our unit. RESULTS: The overall average knowledge-based scores of the cohort pre- and post-assessment were 1.48/5 (29.6%) and 3.56/5 (71.5%), respectively. The overall average skills-based scores of the cohort pre- and post-assessments were 3.05/5 (61%) and 4.12/5 (82.5%), respectively. Significant (p<0.01) difference of improvement of knowledge and skills was noted on all trainees. All trainees confirmed that the training module improved their confidence with flexor tendon repair. CONCLUSION: We demonstrate a standardised simulation training framework that employs a 3D printed flexor tendon simulation model proven to improve the skills of residents especially during their early learning curve and which paves the way to a more universal, standardised and validated training across hand surgery.

3D Printed Chest Wall: A Tool for Advanced Microsurgical Training Simulating Depth and Limited View.

The deep inferior epigastric perforator (DIEP) flap has become the free flap of choice for autologous breast reconstruction. However, anastomoses of DIEP pedicles to internal mammary vessels in the chest wall are difficult due to restricted access and the depth of the vessels. Successful performance of such demanding procedures necessitates advanced requirements for microsurgical training models. The current chicken thigh model has been used to acquire microsurgical skills, allowing early learning curve trainees to practice repeatedly in inconsequential environments. Despite the increasing use of this model for training purposes, the resemblance to a clinical environment is tenuous. Such models should include anastomosis practice within the depth where the recipient vessels are located. To address this, we developed a three-dimensional (3D) printed chest wall as an addition to the current chicken thigh model, which reliably mimics the complexity of the anastomosis performed during DIEP breast reconstruction. This form of rapid prototyping facilitates a newfound ability for early learning curve trainees to exercise end-to-end anastomoses on vessels located with variable depths. Our enhancement of the current chicken thigh model is simple, cost-effective and offers a significantly more realistic resemblance to a clinical situation.

Postoperative care after lymphaticovenous anastomosis.

In this report, we discuss the postoperative protocol for patients undergoing lymphaticovenous anastomosis (LVA) in our unit. Immediately after LVA, the incision site is closed over a small Penrose drain and a simple gauze dressing is applied without compression. In the first 5 days, ambulation is allowed, but limb elevation is actively encouraged to promote lymphatic flow across the newly formed anastomosis. Prophylactic antibiotics are routinely given to prevent infection because this patient group is susceptible to infections, which could trigger thrombosis in the anastomosis.

Three-dimensional Printed Customized Adjustable Mallet Finger Splint: A Cheap, Effective, and Comfortable Alternative.

Mallet finger deformity is a common and debilitating injury of the fingertip, accounting for 10% of all tendon and ligament injuries. It involves a disruption of the terminal extensor mechanism of the distal phalanx. Patients can experience significant pain and swelling of the fingertip and have significant morbidity without treatment. Nonoperative treatment using joint immobilization with splints is the mainstay of management. Traditionally, prefabricated and thermoplastic splints have been utilized; however, issues with comfort and skin complications such as maceration can lead to patient noncompliance and eventually, poor outcomes. To address this, we demonstrate our experience with the design, manufacture, and application of individualized 3D printed mallet finger splints. The splints were found to provide advantages akin to traditional thermoplastic splints, with the addition of being low cost, easy to manufacture, and environmentally friendly.

A Standardized Hand Fracture Fixation Training Framework using Novel 3D Printed Ex Vivo Hand Models: Our Experience as a Unit.

Surgery for hand trauma accounts for a significant proportion of the plastic surgery training curriculum. The aim of this study was to create a standardized simulation training module for hand fracture fixation with Kirschner wire (K-wire) techniques for residents to create a standardized hand training framework that universally hones their skill and prepares them for their first encounter in a clinical setting. METHODS: A step-ladder approach training with 6 levels of difficulty on 3-dimensional (3D) printed ex vivo hand biomimetics was employed on a cohort of 20 plastic surgery residents (n = 20). Assessment of skills using a score system (global rating scale) was performed in the beginning and at the end of the module by hand experts of our unit. RESULTS: The overall average scores of the cohort before and after assessment were 23.75/40 (59.4%) and 34.7/40 (86.8%), respectively. Significant (P < 0.01) difference of improvement of skills was noted on all trainees. All trainees confirmed that the simulated models provided in this module were akin to the patient scenario and noted that it helped them improve their skills with regard to K-wire fixation techniques, including improvement of their understanding of the 3D bone topography. CONCLUSIONS: We demonstrate a standardized simulation training framework that employs 3D printed ex vivo hand biomimetics proved to improve the skills of residents and that paves the way to more universal, standardized and validated training across hand surgery. This is, to our knowledge, the first standardized method of simulated training on such hand surgical cases.

Outcomes following head neck free flap reconstruction requiring interposition vein graft or vascular bridge flap.

BACKGROUND: Interposition vein grafts (IVG) and vascular bridge flaps (VBF) have been exploited as vascular conduit in challenging head and neck reconstructions. METHODS: A retrospective review was conducted on 6025 flaps. The effect of patients' characteristics and length of IVG on flap compromise and loss were analyzed. Comparison between IVG and VBF was performed. RESULTS: The flap compromise and loss rates for the overall group were 8.2% and 3.2%, respectively. An IVG was used in 309 free flaps. The average length of the vein grafts was 6.9 ± 4.2 cm. An unplanned return to the operation room occurred in 32 cases (10.4%) and failure of the flap in 12 patients (3.9%). Binary logistic regression found a significant association between flap compromise and loss rates and length of IVG, hypertension, prior radiation, and neck dissection. In the multiple regression model, length of IVG and prior radiation significantly influenced the outcomes. Thirty-nine patients underwent reconstruction with a long IVG (>10 cm). Twenty-six patients underwent surgical reconstruction with radial forearm flap as a VBF. The rate of flap compromise was higher in the group with a long IVG (P = .01). CONCLUSIONS: In head and neck free flap reconstruction, the length of IVGs and history of radiotherapy are associated with flap compromise and loss. In case of long distance between the pedicle and the recipient site, the use of a VBF bridge should be considered as a safe alternative.

Spontaneous closed zone IV rupture of flexor digitorum profundus tendon to the fifth finger.

We present a case of spontaneous closed flexor digitorum profundus (FDP) tendon rupture of the fifth finger occurring in the carpal tunnel region (Zone IV) of the hand. A review of literature illustrates that spontaneous rupture of FDP in Zone IV is extremely rare and we wish to highlight this.

Cross-Linked Cholecyst-Derived Extracellular Matrix for Abdominal Wall Repair.

Abdominal wall repair frequently utilizes either nondegradable or biodegradable meshes, which are found to stimulate undesirable biological tissue responses or which possess suboptimal degradation rate. In this study, a biologic mesh prototype made from carbodiimide cross-linked cholecyst-derived extracellular matrix (EDCxCEM) was compared with small intestinal submucosa (Surgisis®), cross-linked bovine pericardium (Peri-Guard®), and polypropylene (Prolene®) meshes in an in vivo rabbit model. The macroscopic appearance and stereological parameters of the meshes were evaluated. Tailoring the degradation of the EDCxCEM mesh prevents untimely degradation, while allowing cellular infiltration and mesh remodeling to take place in a slower but predictable manner. The results suggest that the cross-linked biodegradable cholecyst-derived biologic mesh results in no seroma formation, low adhesion, and moderate stretching of the mesh. In contrast to Surgisis, Peri-Guard, and Prolene meshes, the EDCxCEM mesh showed a statistically significant increase in the volume fraction (Vv) of collagen (from 34% to 52.1%) in the central fibrous tissue region at both day 28 and 56. The statistically high length density (Lv), of blood vessels for the EDCxCEM mesh at 28 days was reflected also by the higher cellular activity (high Vv of fibroblast and moderate Vv of nuclei) indicating remodeling of this region in the vicinity of a slowly degrading EDCxCEM mesh. The lack of mesh area stretching/shrinkage in the EDCxCEM mesh showed that the remodeled tissue was adequate to prevent hernia formation. The stereo-histological assays suggest that the EDCxCEM delayed degradation profile supports host wound healing processes including collagen formation, cellular infiltration, and angiogenesis. The use of cross-linked CEM for abdominal wall repair is promising.

A case of recurring multifocal giant cell tumour of the tendon sheath in a child.

Giant cell tumour of the tendon sheath is rare in children. We present an unusual case of a recurring multifocal giant cell tumour of the tendon sheath in the hand and wrist of an 11-year-old boy. We are not aware of any similar report in the literature.

Sea urchin spine arthritis of the proximal interphalangeal joint of the hand: radiological, intraoperative and histopathological findings.

Penetrating sea urchin spine injuries, can lead to devastating, irreversible consequences. Persistent inflammation, cutaneous granuloma, neuroma, tenosynovitis, arthritis and destructive arthritis, leading to permanent loss of function and digit amputation, can occur. We present a case of a patient who developed sea urchin spine arthritis of the proximal interphalangeal joint. Only 17 cases of sea urchin spine arthritis of the hand have been documented in the medical literature. However, in this case, the article also includes sequential radiographs, histopathological slides, and intra-operative photographs.

Perceptions and satisfaction of aesthetic outcome following secondary cleft rhinoplasty: evaluation by patients versus health professionals.

OBJECTIVE: To explore how improvement in facial appearance is related to patients' perception and satisfaction following cleft rhinoplasty. DESIGN: A cross-sectional survey. PARTICIPANTS: 35 cleft rhinoplasty patients treated between 2005 and 2010. 45 observers comprised of healthcare professionals. MAIN OUTCOME MEASURES: Evaluation of patient satisfaction including Rhinoplasty Outcome Evaluation (ROE) questionnaire, Preoperative and Postoperative Semi-quantitative Ordinal Scale Rating (PPSOSR) and a specifically designed semi-structured questionnaire. Evaluation by panel of observers using Asher-McDade Aesthetic Index (AMAI) Rating and PPSOSR. RESULTS: Patient satisfaction was high, based on the ROE questionnaire (score 76.1). 91% of patients rated their appearance as improved, 3% remained 'uncertain' and 6% felt 'different but not improved.' Teenage females (score 94.1) showed statistically higher satisfaction, when compared to older females (score 75.5), or their male counterparts (score 69.8). The preoperative appearance ratings were not statistically different between patients and panel members but postoperatively, patients' rating of their appearance was statistically higher. All components of the AMAI were scored between 'good' to 'fair' (score 9.3). Seventy percent of the panel rated the postoperative appearance as improved. Interestingly, 10% rated the postoperative appearance as 'unchanged', while 3% reported a 'worsened' appearance. There was no correlation between panel assessment of aesthetic outcome and patient satisfaction. CONCLUSIONS: Cleft rhinoplasty contributes to subjective patient satisfaction as a result of their perceived improvement in appearance and function, even though this was not correlated to objective aesthetic rating by panel members.

Efficacy of crosslinking on tailoring in vivo biodegradability of fibro-porous decellularized extracellular matrix and restoration of native tissue structure: a quantitative study using stereology methods.

Cholecyst-derived extracellular matrix (CEM) is a fibro-porous decellularized serosal layer of porcine gall-bladder. CEM loses 90% of its weight at 48 h of in vitro collagenase digestion, but takes two months to be completely resorbed in vivo. Carbodiimide (EDC) crosslinking helps tailoring CEM's in vitro collagenase susceptibility. Here, the efficacy of EDC crosslinking on tailoring in vivo biodegradability of CEM is reported. CEM crosslinked with 0.0005 and 0.0033 × 10(3) M of EDC/mg that lose 80% and 0% of their weight respectively to in vitro collagenase digestion, were present even after 180 days in vivo. Quantitative histopathology using stereology methods confirmed our qualitative observation that even a tiny degree of crosslinking can significantly prolong the rate of in vivo degradation and removal of CEM.

Intraoperative findings of necrotizing fasciitis of the hand caused by Staphylococcus aureus infection.

A case of a 35-year-old male with necrotizing fasciitis of the hand is presented. Clinical manifestations of necrotizing fasciitis are discussed and intraoperative findings are highlighted to illustrate the disease process that initially affects the deep layer of the superficial fascia.

Full thickness burn caused by exposure to giant hogweed: delayed presentation, histological features and surgical management.

We report the case of a 10-year-old boy with a full thickness chemical burn on his right pretibial area due to phytophotodermatitis (PPD) following contact with giant hogweed (Heracleum mantegazzianum). Although cutaneous burns due to plants are a well-established cause of chemical burn, previous reports described partial thickness burns that healed with conservative measures. This patient presented to our unit two weeks after the initial injury with an established full thickness burn. Debridement and split thickness skin grafting was required. We presented the histological features of the debrided skin specimen and discussed potential factors leading to this unexpected full thickness injury.

Tailoring the properties of cholecyst-derived extracellular matrix using carbodiimide cross-linking.

Modulation of properties of extracellular matrix (ECM) based scaffolds is key for their application in the clinical setting. In the present study, cross-linking was used as a tool for tailoring the properties of cholecyst-derived extracellular matrix (CEM). CEM was cross-linked with varying cross-linking concentrations of N,N-(3-dimethyl aminopropyl)-N'-ethyl carbodiimide (EDC) in the presence of N-hydroxysuccinimide (NHS). Shrink temperature measurements and ATR-FT-IR spectra were used to determine the degree of cross-linking. The effect of cross-linking on degradation was tested using the collagenase assay. Uniaxial tensile properties and the ability to support fibroblasts were also evaluated as a function of cross-linking. Shrink temperature increased from 59 degrees C for non-cross-linked CEM to 78 degrees C for the highest EDC cross-linking concentration, while IR peak area ratios for the free -NH(2) group at 3290 cm(-1) to that of the amide I band at 1635 cm(-1) decreased with increasing EDC cross-linking concentration. Collagenase assay demonstrated that degradation rates for CEM can be tailored. EDC concentrations 0 to 0.0033 mmol/mg CEM were the cross-linking concentration range in which CEM showed varied susceptibility to collagenase degradation. Furthermore, cross-linking concentrations up to 0.1 mmol EDC/mg CEM did not have statistically significant effect on the uniaxial tensile strength, as well as morphology, viability and proliferation of fibroblasts on CEM. In conclusion, the degradation rates of CEM can be tailored using EDC-cross-linking, while maintaining the mechanical properties and the ability of CEM to support cells.

Illness representations in patients with hand injury.

PURPOSE: Differences in illness perception about hand injury may partly explain the variation in health behaviours such as adherence to post-operative therapy, coping strategy, emotional response and eventual clinical outcome. This study examined the illness perception of patients with hand injuries in the acute trauma setting. METHODS: The disability and severity of injury were assessed using the Disability of the Arm, Shoulder and Hand (DASH) questionnaire and the Hand Injury Severity Score (HISS). The revised Illness Perception Questionnaire (IPQ-R) was used to explore patients' illness beliefs and perception on hand injury. RESULTS: Fifty seven patients were recruited over the 2 month period. The IPQ-R showed good internal reliability (Cronbach's alpha, 0.68-0.86). There was no correlation between the DASH or HISS scores and the various components of the IPQ-R scores, suggesting that illness perceptions were not influenced by the recent trauma experience. Patients with dominant hand injuries and females reported significantly higher subjective disability. Younger patients believed their injury would last for a limited duration but reported a significantly higher number of related symptoms. Overall, the cohort was optimistic about their treatment and duration of recovery (high treatment control score and low time line score). Beliefs of negative consequences, chronic/cyclical duration and low illness coherence were linked with negative emotional response. High illness identity was associated with perception of pessimistic outcome (high consequences score) and negative emotional response. CONCLUSIONS: The lack of correlations suggests that illness perceptions of patients do not necessarily relate to the recent trauma experience or the severity of their hand injury. Patients in this cohort were optimistic about treatment and their recovery. There was some evidence to suggest that patients with severe injury were over-optimistic about recovery. These findings suggest that there could be a role for psychological intervention in hand injury.

Buttressing staples with cholecyst-derived extracellular matrix (CEM) reinforces staple lines in an ex vivo peristaltic inflation model.

BACKGROUND: Staple line leakage and bleeding are the most common problems associated with the use of surgical staplers for gastrointestinal resection and anastomotic procedures. These complications can be reduced by reinforcing the staple lines with buttressing materials. The current study reports the potential use of cholecyst-derived extracellular matrix (CEM) in non-crosslinked (NCEM) and crosslinked (XCEM) forms, and compares their mechanical performance with clinically available buttress materials [small intestinal submucosa (SIS) and bovine pericardium (BP)] in an ex vivo small intestine model. METHODS: Three crosslinked CEM variants (XCEM0005, XCEM001, and XCEM0033) with different degree of crosslinking were produced. An ex vivo peristaltic inflation model was established. Porcine small intestine segments were stapled on one end, using buttressed or non-buttressed surgical staplers. The opened, non-stapled ends were connected to a peristaltic pump and pressure transducer and sealed. The staple lines were then exposed to increased intraluminal pressure in a peristaltic manner. Both the leak and burst pressures of the test specimens were recorded. RESULTS: The leak pressures observed for non-crosslinked NCEM (137.8 +/- 22.3 mmHg), crosslinked XCEM0005 (109.1 +/- 14.1 mmHg), XCEM001 (150.1 +/- 16.0 mmHg), XCEM0033 (98.8 +/- 10.5 mmHg) reinforced staple lines were significantly higher when compared to non-buttressed control (28.3 +/- 10.8 mmHg) and SIS (one and four layers) (62.6 +/- 11.8 and 57.6 +/- 12.3 mmHg, respectively) buttressed staple lines. NCEM and XCEM were comparable to that observed for BP buttressed staple lines (138.8 +/- 3.6 mmHg). Only specimens with reinforced staple lines were able to achieve high intraluminal pressures (ruptured at the intestinal mesentery), indicating that buttress reinforcements were able to withstand pressure higher than that of natural tissue (physiological failure). CONCLUSIONS: These findings suggest that the use of CEM and XCEM as buttressing materials is associated with reinforced staple lines and increased leak pressures when compared to non-buttressed staple lines. CEM and XCEM were found to perform comparably with clinically available buttress materials in this ex vivo model.