Realistic irrigation visualization in a surgical wound debridement simulator

Wound debridement refers to the removal of necrotic, devitalized, or contaminated tissue and/or foreign material to promote wound healing. Surgical debridement uses sharp instruments to cut dead tissue from a wound and it is the quickest and most efficient method of debridement. A wound debridement simulator [1,2] can ensure that a medical trainee is competent prior to performing a procedure on a genuine patient. Irrigation is performed at different stages of debridement in order to remove debris and reduce the bacteria count through rinsing the wound. This paper presents a novel approach for realistic irrigation visualization based on texture representations of debris. This approach applies image processing techniques to a series of images, which model the cleanliness of the wound. The active texture is generated and updated dynamically based on the irrigation state, location, and range. Presented results demonstrate that texture mapping and image processing techniques can provide effective and efficient solutions for irrigation visualization in the wound debridement simulator.

A simulation-based training system for surgical wound debridement

A simulation-based training system for surgical wound debridement was developed and comprises a multimedia introduction, a surgical simulator (tutorial component), and an assessment component. The simulator includes two PCs, a haptic device, and mirrored display. Debridement is performed on a virtual leg model with a shallow laceration wound superimposed. Trainees are instructed to remove debris with forceps, scrub with a brush, and rinse with saline solution to maintain sterility. Research and development issues currently under investigation include tissue deformation models using mass-spring system and finite element methods; tissue cutting using a high-resolution volumetric mesh and dynamic topology; and accurate collision detection, cutting, and soft-body haptic rendering for two devices within the same haptic space.

Conservative surgical debridement as a burn treatment : supporting evidence from a porcine burn model

In thermal deep-dermal burns, surgical debridement is normally used in conjunction with skin grafting or skin substitutes and debridement alone as a burn treatment is not usually practiced. The current study addresses whether or not debridement alone would enhance burn wound healing on small deep-dermal-partial thickness burns. This was a prospective and blinded experimental trial using a porcine deep-dermal-partial thickness burn model. Four burns, approximately 50 cm(2) in size, were created on each of eight pigs. Two burns from each pig were immediately surgically debrided and the other two were not debrided as the internal control. Hydrate gel together with paraffin gauze were used to cover the burns for four pigs and silver dressings for the other four. Clinical assessment of wound healing was conducted over a 6-week period. Skin samples were collected at the end of the experiment and histopathological evaluation was performed. The results show thinner scar formation and lower scar height in the debrided compared with nondebrided wounds in the hydrate gel/paraffin gauze groups. There were no statistically significant differences in wound healing assessment between the debrided and nondebrided wounds dressed with silver dressings. This study provides supporting evidence that immediate debridement with an appropriate dressing and without skin grafting may promote wound healing, suggesting its potential benefit for clinical patients.

Percutaneous insertion of Dual Growth Rods using a new mobile bearing implant

Growth rods are commonly used for the treatment of scoliosis in the immature spine. Many variations have been proposed but breakage of implants is a common problem. Growth rod insertion commonly involves large exposures at initial insertion followed by multiple smaller procedures for lengthening. We present our early experiences using a percutaneous technique of insertion of a new titanium mobile bearing implant (Medtronic Inc). The implant allows some rotatory motion in the middle of the construct thus reducing construct stresses and thus possibly reducing rod breakage risk. Based on this small initial series with 12 months follow-up, percutaneous insertion of growth rods using the new implant is a safe and reliable technique although the infection rate in our sample was of note. This may be related to the titanium wear and inflammation seen in the soft tissues at time of operation and visualised on histology. No implants have required removal due to infection, and all infections were treated with debridement at next lengthening and suppressive antibiotics. Propionibacterium is one of the commonest infections seen with spinal implants and sometimes does not respond to simple antibiotic suppression. The technique allows preservation of the soft tissues until definitive fusion is needed and may lead to a decrease in hospital stay. The implant is low profile and seems to offer advantages over other systems on the market. Further follow up is needed to look at longer term outcomes with this new implant type.

Is it necessary to re-fuse a non-union of a hallux metatarsophalangeal joint arthrodesis?

BACKGROUND: The standard treatment for a non-union of the hallux metatarsophalangeal joint fusion has been to revise the fusion. Revision fusion is technically more demanding, often involving bone grafting, more substantial fixation and prolonged period of immobilization postoperatively. We present data to suggest that removal of hardware and debridement alone is an alternative treatment option. ---------- MATERIALS AND METHODS: A case note review identified patients with a symptomatic non-union after hallux metatarsophalangeal joint (MTPJ) fusion. It is our practice to offer these patients revision fusion or removal of hardware and debridement. For the seven patients that chose hardware removal and were left with a pseudarthrosis, a matched control group was selected from patients who had had successful fusions. Three outcome scores were used. Hallux valgus and dorsiflexion angles were recorded.---------- RESULTS: One hundred thirty-nine hallux MTPJ arthrodeses were carried out. Fourteen non-unions were identified. The rate of non-union in males and following previous hallux MTPJ surgery was 19% and 24%, respectively. In females undergoing a primary MTPJ fusion, the rate was 2.4%. Twelve non-union patients were reviewed at 27 months (mean). Eleven patients had elected to undergo removal of hardware and debridement. Four patients with pseudarthrosis were unhappy with the results and proceeded to either revision fusion or MTPJ replacement. Seven non-union patients, who had removal of hardware alone, had outcome scores marginally worse compared to those with successful fusions.---------- CONCLUSION: Removal of hardware alone is a reasonable option to offer as a relatively minor procedure following a failed arthrodesis of the first MTPJ. This must be accepted on the proviso that in this study four out of 11 (36%) patients proceeded to a revision first MTPJ fusion or first MTPJ replacement. We also found that the rate of non-union in primary first MTPJ fusion was significantly higher in males and those patients who had undergone previous surgery.

Wound healing angiogenesis : the clinical implications of a simple mathematical model

Nonhealing wounds are a major burden for health care systems worldwide. In addition, a patient who suffers from this type of wound usually has a reduced quality of life. While the wound healing process is undoubtedly complex, in this paper we develop a deterministic mathematical model, formulated as a system of partial differential equations, that focusses on an important aspect of successful healing: oxygen supply to the wound bed by a combination of diffusion from the surrounding unwounded tissue and delivery from newly formed blood vessels. While the model equations can be solved numerically, the emphasis here is on the use of asymptotic methods to establish conditions under which new blood vessel growth can be initiated and wound-bed angiogenesis can progress. These conditions are given in terms of key model parameters including the rate of oxygen supply and its rate of consumption in the wound. We use our model to discuss the clinical use of treatments such as hyperbaric oxygen therapy, wound bed debridement, and revascularisation therapy that have the potential to initiate healing in chronic, stalled wounds.

Prevention of pelvic sepsis in major open pelviperineal injury

Compound pelvic fractures are deemed to be one of the most severe orthopaedic injuries with an extremely high morbidity and mortality. After the initial resuscitation phase the prevention of pelvic sepsis is one of the main treatment goals for patients with an open pelvic fracture. If there is a suspicion of a rectal injury or if the wounds are in the perineal area, The Princess Alexandra Hospital's management plan includes early faecal diversion combined with vigorous soft tissue debridement, VAC(®) therapy and (if indicated) external fixation of the pelvic fracture. We present our flowchart for the treatment of trauma patients with compound pelvic fractures illustrated by a case report describing a 32 year old patient who sustained an open pelvic ring injury in a workplace accident. The aim of this paper is to underline the importance of a safe, straightforward approach to compound pelvic fractures.

Australian Diabetes Foot Network : management of diabetes-related foot ulceration — a clinical update

Summary Appropriate assessment and management of diabetes-related foot ulcers (DRFUs) is essential to reduce amputation risk. Management requires debridement, wound dressing, pressure off-loading, good glycaemic control and potentially antibiotic therapy and vascular intervention. As a minimum, all DRFUs should be managed by a doctor and a podiatrist and/or wound care nurse. Health professionals unable to provide appropriate care for people with DRFUs should promptly refer individuals to professionals with the requisite knowledge and skills. Indicators for immediate referral to an emergency department or multidisciplinary foot care team (MFCT) include gangrene, limb-threatening ischaemia, deep ulcers (bone, joint or tendon in the wound base), ascending cellulitis, systemic symptoms of infection and abscesses. Referral to an MFCT should occur if there is lack of wound progress after 4 weeks of appropriate treatment.

Surgical treatment approaches and reimbursement costs of surgical site infections post hip arthroplasty in Australia : a retrospective analysis

BACKGROUND: The treatment for deep surgical site infection (SSI) following primary total hip arthroplasty (THA) varies internationally and it is at present unclear which treatment approaches are used in Australia. The aim of this study is to identify current treatment approaches in Queensland, Australia, show success rates and quantify the costs of different treatments. METHODS: Data for patients undergoing primary THA and treatment for infection between January 2006 and December 2009 in Queensland hospitals were extracted from routinely used hospital databases. Records were linked with pathology information to confirm positive organisms. Diagnosis and treatment of infection was determined using ICD-10-AM and ACHI codes, respectively. Treatment costs were estimated based on AR-DRG cost accounting codes assigned to each patient hospital episode. RESULTS: A total of n=114 patients with deep surgical site infection were identified. The majority of patients (74%) were first treated with debridement, antibiotics and implant retention (DAIR), which was successful in eradicating the infection in 60.3% of patients with an average cost of $13,187. The remaining first treatments were 1-stage revision, successful in 89.7% with average costs of $27,006, and 2-stage revisions, successful in 92.9% of cases with average costs of $42,772. Multiple treatments following 'failed DAIR' cost on average $29,560, for failed 1-stage revision were $24,357, for failed 2-stage revision were $70,381 and were $23,805 for excision arthroplasty. CONCLUSIONS: As treatment costs in Australia are high primary prevention is important and the economics of competing treatment choices should be carefully considered. These currently vary greatly across international settings.

The poor penetration of topical burn agent through burn eschar on a porcine burn model [Letter to the Editor]

We read with great interest the article entitled “Enhancing drugs absorption through third-degree burn wound eschar” by Manafi et al. [1]. The authors addressed the concern of poor penetration of topically applied anti-microbials through burn eschar and detailed the improvement of this penetration by penetration enhancers. Here, we would like to report the poor penetration of a topical agent into the viable deep dermal layer under burn eschar on a porcine burn model [2]. In burn treatment, a common practice is the topical application of either anti-microbial products or wound enhancing agents. While the activity of anti-microbial products is designed to fight against microbes on the wound surface but with the least toxicity to viable tissue, wound enhancing agents need to reach the viable tissue layer under the burn eschar. Many studies have reported the accelerated healing of superficial burn wounds and skin graft donor sites by the topical application of exogeneous growth factors [3]. It is well known that the efficacy of the penetration of a topical agent on intact skin mostly depends on the molecular size of the product [4] and [5]. While burn injury destroys this epidermal physiological barrier, the coagulated burn tissue layer on the burn wound surface makes it difficult for topical agents to reach viable tissue....

Effects of anticoagulants on outcome of femoral neck fracture surgery

PURPOSE To review records of 330 patients who underwent surgery for femoral neck fractures with or without preoperative anticoagulation therapy. METHODS Medical records of 235 women and 95 men aged 48 to 103 years (mean, 81.6; standard deviation [SD], 13.1) who underwent surgery for femoral neck fractures with or without preoperative anticoagulation therapy were reviewed. 30 patients were on warfarin, 105 on aspirin, 28 on clopidogrel, and 167 were controls. The latter 3 groups were combined as the non-warfarin group and compared with the warfarin group. Hospital mortality, time from admission to surgery, length of hospital stay, return to theatre, and postoperative complications (wound infection, deep vein thrombosis, and pulmonary embolism) were assessed. RESULTS The warfarin and control groups were significantly younger than the clopidogrel and aspirin groups (80.8 vs. 80.0 vs. 84.2 vs. 83.7 years, respectively, p<0.05). 81% of the patients underwent surgery within 48 hours of admission. The overall mean time from admission to surgery was 1.8 days; it was longer in the warfarin than the aspirin, clopidogrel, and control groups (3.3 vs. 1.8 vs. 1.6 vs. 1.6 days, respectively, p<0.001). The mean length of hospital stay was 17.5 (SD, 9.6; range, 3-54) days. The overall hospital mortality was 3.9%; it was 6.7% in the warfarin group, 3.8% in the aspirin group, 3.6% in the clopidogrel group, and 3.6% in the control group (p=0.80). Four patients returned to theatre for surgery: one in the warfarin group for washout of a haematoma, 2 in the aspirin group for repositioning of a mal-fixation and for debridement of wound infection, and one in the control group for debridement of wound infection. The warfarin group did not differ significantly from non-warfarin group in terms of postoperative complication rate (6.7% vs. 2.7%, p=0.228) and the rate of return to theatre (3.3% vs. 1%, p=0.318). CONCLUSION It is safe to continue aspirin and clopidogrel prior to surgical treatment for femoral neck fracture. The risk of delaying surgery outweighs the peri-operative bleeding risk.

Scoping study into wound management nurse practitioner models of practice

Objectives The primary objective of this research was to investigate wound management nurse practitioner (WMNP) models of service for the purposes of identifying parameters of practice and how patient outcomes are measured. Methods A scoping study was conducted with all authorised WMNPs in Australia from October to December 2012 using survey methodology. A questionnaire was developed to obtain data on the role and practice parameters of authorised WMNPs in Australia. The tool comprised seven sections and included a total of 59 questions. The questionnaire was distributed to all members of the WMNP Online Peer Review Group, to which it was anticipated the majority of WMNPs belonged. Results Twenty-one WMNPs responded (response rate 87%), with the results based on a subset of respondents who stated that, at the time of the questionnaire, they were employed as a WMNP, therefore yielding a response rate of 71% (n≤15). Most respondents (93%; n≤14) were employed in the public sector, with an average of 64 occasions of service per month. The typical length of a new case consultation was 60min, with 32min for follow ups. The most frequently performed activity was wound photography (83%; n≤12), patient, family or carer education (75%; n≤12), Doppler ankle-brachial pressure index assessment (58%; n≤12), conservative sharp wound debridement (58%; n≤12) and counselling (50%; n≤12). The most routinely prescribed medications were local anaesthetics (25%; n≤12) and oral antibiotics (25%; n≤12). Data were routinely collected by 91% of respondents on service-related and wound-related parameters to monitor patient outcomes, to justify and improve health services provided. Conclusion This study yielded important baseline information on this professional group, including data on patient problems managed, the types of interventions implemented, the resources used to accomplish outcomes and how outcomes are measured.

Superior perilimbal epitheliopathy in recurrent corneal erosion syndrome

Purpose To highlight the finding of occult areas of poor epithelial adhesion in the superior perilimbal cornea in a minority of patients with recalcitrant recurrent corneal erosion syndrome presenting with corneal erosion elsewhere on the corneal surface. Patient population 31 eyes of 31 consecutive patients with corneal erosion undergoing mechanical debridement of the epithelium prior to diamond burr keratectomy for recurrent corneal erosion. Methods Determine the location and incidence of poor epithelial adhesion distant from the initial erosion by use of mechanical debridement with a dry microsponge. Results During debridement, 8 of 31 eyes (25.8%) displayed a large arcuate area of occult dysfunction of adhesion in the superior perilimbal area. None of these patients showed recurrence over a mean of 18 month after diamond burr keratectomy (95% confidence interval 0-36.9%). Conclusion Mechanical debridement with a microsponge identified a significant minority of patients with poor adhesion in the superior perilimbal cornea away from the area of obvious erosion and increased the target area for diamond burr keratectomy. This two pronged approach allowed successful management of this group.