Aims. The aims of this study were to report the outcomes of patients with a complex fracture of the lower limb in the five years after they took part in the
Extracellular matrix (ECM) mechanical cues guide healing in tendons. Yet, the molecular mechanisms orchestrating the healing processes remain elusive. Appropriate tissue tension is essential for tendon homeostasis and tissue health. By mapping the attainment of tensional homeostasis, we aim to understand how ECM tension regulates healing. We hypothesize that diseased tendon returns to homeostasis only after the cells reach a mechanically gated exit from wound healing. We engineered a 3D mechano-culture system to create tendon-like constructs by embedding patient-derived tendon cells into a collagen I hydrogel. Casting the hydrogel between posts anchored in silicone allowed adjusting the post stiffness. Under this static mechanical stimulation, cells remodel the (unorganized) collagen representing wound healing mechanisms. We quantified tissue-level forces using post deflection measurements. Secreted ECM was visualized by metabolic labelling with non-canonical amino acids, click chemistry and confocal microscopy. We blocked cell-mediated actin-myosin contractility using a ROCK inhibitor (Y27632) to explore the involvement of the Rho/ROCK pathway in tension regulation. Tissue tension forces reached the same homeostatic level at day 21 independent of post compliance (p = 0.9456). While minimal matrix was synthesized in early phases of tissue formation (d3-d5), cell-deposited ECM was present in later stages (d7-d9). More ECM was deposited by tendon constructs cultured on compliant (1Nm) compared to rigid posts (p = 0.0017). Matrix synthesized by constructs cultured on compliant posts was less aligned (greater fiber dispersion, p = 0.0021). ROCK inhibition significantly decreased tissue-level tensional forces (p < 0.0001). Our results indicate that tendon cells balance matrix remodeling and synthesis during tissue repair to reach an intrinsically defined “mechanostat setpoint” guiding tension-mediated exit from wound healing towards homeostasis. We are identifying specific molecular mechanosensors governing tension-regulated healing in tendon and investigate the Rho/ROCK system as their possible downstream pathway.
Treatment for delayed wound healing resulting from peripheral vascular diseases and diabetic foot ulcers remain a challenge. A novel surgical technique named Tibial Cortex Transverse Transport has been developed for treating peripheral ischaemia, with encouraging clinical effects. However, its underlying mechanisms remain unclear. In present study, we aimed to explore the wound healing effects after undergoing this novel technique via multiple ways. A novel rat model of Tibial Cortex Transverse Transport was established with a designed external fixator and effects on wound healing were investigated. All rats were randomized into 3 groups, with 12 rats per group: sham group (negative control), fixator group (positive control) and Tibial Cortex Transverse Transport group. Laser speckle perfusion imaging, vessel perfusion, histology and immunohistochemistry were used to evaluate the wound healing processes. Gross and histological examinations showed that Tibial Cortex Transverse Transport technique accelerated wound closure and enhanced the quality of the newly formed skin tissues. In Tibial Cortex Transverse Transport group, HE staining demonstrated a better epidermis and dermis recovery, while immune-histochemical staining showed that Tibial Cortex Transverse Transport technique promoted local collagen deposition. Tibial Cortex Transverse Transport technique also benefited to angiogenesis and immunomodulation. In Tibial Cortex Transverse Transport group, blood flow in the wound area was higher than that ofother groups according to laser speckle imaging with more blood vessels observed. Enhanced neovascularization was seen in the Tibial Cortex Transverse Transport group with double immune-labelling of CD31 and α-SMA. The M2 macrophages at the wound site in the Tibial Cortex Transverse Transport group was also increased. Tibial cortex transverse transport technique accelerated wound healing through enhanced angiogenesis and immunomodulation.
Aims. This study aims to estimate economic outcomes associated with 30-day deep surgical site infection (SSI) from closed surgical wounds in patients with lower limb fractures following major trauma. Methods. Data from the
Drainage from the knee wound after TKA is an obvious concern for the arthroplasty surgeon. One of the inherent problems with a total knee arthroplasty is there is a focus on obtaining maximum range of motion but at the same time the wound needs to heal in a timely fashion. Consistent knee drainage after a TKA is a source of concern. The quantity and quality of drainage needs to be assessed and there are certain questions that need to be answered including: 1) Is there bloody drainage which suggests fascial dehiscence?; 2) Is the patient too active?; 3) Is the drainage in some way related to DVT prophylaxis?; 4) Is the patient obese and could the drainage be secondary to fat necrosis or seroma? and 5) Is the drainage suggestive of an infection? The work-up can include C-reactive protein and sed rate, and possibly a knee aspiration. In general, C-reactive protein >100mg/L within the first six weeks after surgery suggests the presence of an infection. The sed rate is generally not useful in the early post-operative period. In the first six weeks after surgery if the number of white cells in the aspiration is >10,000 this suggests infection especially if there are 80–90% polymorphonuclear cells. Each day of prolonged wound drainage is noted to increase the risk of infection by 29%. Morbid obesity has been shown to be an independent risk factor for infection. Some anticoagulants (i.e. low molecular weight heparin) have been associated with increased wound drainage. In a retrospective review of 11,785 total joint arthroplasties, 2.9% of joints developed wound drainage, and of these patients, 28% required further surgery. It was noted that patients that were malnourished had a 35% failure rate with respect to controlling the drainage and preventing infection versus 5% in patients that were healthy. The International Consensus Conference on Infection concluded that a wound that has been persistently draining for greater than 5–7 days requires surgical intervention. The available literature provides little guidance regarding the specifics of this procedure. In general, if the wound is draining or is red, rest the leg for a day or two. In some instances a bulky Jones dressing can be helpful. If the drainage persists one could consider using a negative pressure dressing (wound vac) but there is little data on efficacy after TKA. If there is persistent drainage or cellulitis, then operative intervention is probably necessary. Evaluation of CRP and a knee joint aspiration can be helpful. The decision to return to the OR should be made within the first 7 days after the surgery. At the time of the procedure one will need to decide to perform either a superficial washout versus a washout and polyethylene exchange.
Drainage from the knee wound after TKA is an obvious concern for the arthroplasty surgeon. One of the inherent problems with a total knee arthroplasty is there is a focus on obtaining maximum range of motion but at the same time the wound needs to heal in a timely fashion. Consistent knee drainage after a TKA is a source of concern. The quantity and quality of drainage needs to be assessed and there are certain questions that need to be answered including: 1) Is there bloody drainage which suggests fascial dehiscence?; 2) Is the patient too active?; 3) Is the drainage in some way related to DVT prophylaxis?; 4) Is the patient obese and could the drainage be secondary to fat necrosis or seroma? and 5) Is the drainage suggestive of an infection? The work up can include C-reactive protein and sed rate, and possibly a knee aspiration. In general, C-reactive protein >100 mg/L within the first six weeks after surgery suggests the presence of an infection. The sed rate is generally not useful in the early post-operative period. In the first six weeks after surgery if the number of white cells in the aspiration is >10,000 this suggests infection especially if there are 80–90% polymorphonuclear cells. Each day of prolonged wound drainage is noted to increase the risk of infection by 29%. Morbid obesity has been shown to be an independent risk factor for infection. Some anticoagulants (i.e. low molecular weight heparin) have been associated with increased wound drainage. In a retrospective review of 11,785 total joint arthroplasties, 2.9% of joints developed wound drainage, and of these patients, 28% required further surgery. It was noted that patients that were malnourished had a 35% failure rate with respect to controlling the drainage and preventing infection versus 5% in patients that were healthy. The International Consensus Conference on Infection concluded that a wound that has been persistently draining for greater than 5–7 days requires surgical intervention. The available literature provides little guidance regarding the specifics of this procedure. In general, if the wound is draining or is red, rest the leg for a day or two. In some instances a bulky Jones dressing can be helpful. If there is persistent drainage or cellulitis, then operative intervention is probably necessary. Evaluation of CRP and a knee joint aspiration can be helpful. The decision to return to the OR should be made within the first 7 days after the surgery. At the time of the procedure one will need to decide to perform either a superficial washout versus a washout and polyethylene exchange.
Fractures of the ankle are common, and they mostly affect young adults. Wound complications are not uncommon following the fixation of these fractures. This study evaluated the impact of HIV on wound healing after plate osteosynthesis in patients with closed ankle fractures. This is an observational retrospective study of patients operated on at a tertiary level hospital. We reviewed hospital records for patients above 18 years of age who presented with wound breakdown following ankle open reduction and internal fixation. The patients’ hospital records were retrieved to identify all the patients treated for closed ankle fractures and those who developed wound breakdown. Patients with Pilon fractures were excluded. The National Health Laboratory System (NHLS) database was accessed to retrieve the CD4 count, viral load, haematology study results, and biochemistry results of these patients at the time of surgery and subsequent follow-up. The x-rays were retrieved from the electronic picture archiving system (PACS) and were assessed for fracture union at a minimum of 3 months follow-up. We reviewed the medical records of 172 patients with closed ankle fractures treated from 2018 to 2022. Thirty-one (18.0%) developed wound breakdown after surgery, and they were all tested for HIV. Most of the patients were male (58.0%), and the average age of the cohort was 43.7 years (range: 21 years to 84 years). Ten of these patients (32.2%) were confirmed HIV positive, with CD4 counts ranging from 155 to 781. Viral load levels were lower than detectable in 40% of these patients. All patients progressed to fracture union at a minimum of 3 months follow-up. We observed no difference between HIV-positive and HIV-negative patients in terms of wound breakdown and bone healing post-plate osteosynthesis for closed ankle fractures.
Wound condition after primary total knee arthroplasty (TKA) is important for prevention of periprosthetic infection. Any delay in wound healing will cause deep infection, which leads to the arthroplasty failure. Prevention of soft tissue problems is thus essential to achieve excellent clinical results. However, it is unknown as to the important surgical factors affecting the wound healing using detailed wound score after primary TKA so far. It was hypothesized that operative technique would affect wound healing in primary TKA. The purpose of the present study was to investigate and to clarify the important surgical factors affecting wound score after primary TKA. A total of 139 knees in 128 patients (mean 73 years) were enrolled. All primary TKAs were done by single surgeon. All patients underwent unilateral or bilateral TKA using Balanced Knee System®, posterior stabilized (PS) design (Ortho Development, Draper, UT) or Legion®, PS design (Smith and Nephew, Memphis, TN) under general and/or epidural anesthesia. Patients with immunosuppressive therapy, hypokalemia, poor nutrition (albumin < 3.4 g/dL), diverticulosis, infection elsewhere, uncontrolled diabetes mellitus (HbA1C>7.0%), obesity (Body Mass Index > 35 kg/m2), smoking, renal failure, hypothyroidism, alcohol abuse, rheumatoid arthritis, posttraumatic arthritis, and previous knee surgery were excluded. Hollander Wound Evaluation Score (HWES) was assessed on postoperative day 14. We evaluated age, sex, body mass index, HbA1C (%), preoperative femorotibial angle (FTA) on plain radiograph. In addition, intraoperative patella eversion, intraoperative anterior translation of the tibia, patella resurfacing, surgical time, tourniquet time, unidirectional barbed suture and length of skin incision were also evaluated as surgical factors. Multiple regression analysis was done using stepwise method to identify the surgical factors affecting HWES.Introduction
Methods
The mean age was 36 years (range 18 to 57) All but one fracture resulted from a fall from height. Cases were analyzed to ascertain the mechanism of injury, associated injuries, presence of medical problems e.g. Diabetes or peripheral vascular disease, smoking. Number of days elapsed before surgery, method of wound closure, and the use of drain and Saunders grade.
CAR (CARSKNKDC) is a systemically administered wound-homing peptide that specifically recognizes angiogenic blood vessels and extravasates into sites of injury. CAR peptide requires heparan sulfate proteoglycans (HSPGs) for its cell penetrating activity. Syndecan-4 (SDC4) is a HSPG and binding to it triggers the wound re-epithelialization process. We have discovered that CAR peptide has the inherent ability to promote wound healing; wounds close and re-epithelialize significantly faster in CAR treated mice than in control groups (PBS and mutant peptide, i.e. mCAR injections). To delineate the molecular mechanism by which CAR accelerates wound healing, we focused on the requirement of HSPG binding for CAR peptide function. We demonstrate that CAR peptide endocytosis and its stimulation of keratinocyte cell migration are both dependent on SDC4. Finally, we show that the systemic administration of CAR peptide stimulates wound re-epithelialization only in WT mice, but not in SDC4 knockout (KO) mice. As SDC4 has very restricted expression in skin wounds, we propose that CAR peptide activates SDC4 function to promote re-epithelialization. CAR peptide may provide an entirely new way of enhancing wound healing, and perhaps tissue regeneration in general. This therapeutic approach is systemic, yet target organ- and cell- specific, and dependent on the naturally occurring SDC4 dependent migratory pathway that is crucial for tissue regeneration.
A prospective study was undertaken of wound healing in HIV positive patients undergoing orthopaedic implant surgery. 175 implant operations were assessed. 40 operations (23%) were in HIV positive individuals. Wounds were scored using the Asepsis scoring system. Closed fractures in HIV positive patients had 1 (3. 5%) major infection. No correlation was seen between CD4 count and risk of wound infection. With regards to early wound sepsis, implant surgery can be undertaken safely in HIV positive individuals with closed injuries regardless of CD4 count. The risk of wound sepsis rises dramatically in implant surgery for HIV positive patients with open fractures.
Skin necrosis after total knee arthroplasty can rapidly lead to infection of the prosthetic components. Risk factors for the development of skin necrosis include rheumatoid arthritis, steroid use, immunosuppression, malnutrition, peripheral vascular disease, and multiple prior scars. Vascularity of the skin over the knee will affect the rate of healing postoperatively and risk of necrosis. Johnson measured transcutaneous skin oxygen tension and found that the oxygen tension decreases for the first two to three days after surgery and then increases. In addition, the lateral skin edge is more hypoxic than the medial edge. This suggests that when multiple prior scars are present, the most vertical lateral incision should be used to minimise skin hypoxia. Constant passive motion further decreases skin oxygen tension. Particularly for patients with multiple risk factors for developing wound complications, avoidance or delayed used of early range of motion exercises may be beneficial in reducing the development of skin necrosis. If skin necrosis does occur after total knee arthroplasty, early recognition of the problem and treatment will minimise the risk of deep infection of the prosthetic components. Necrosis of the proximal wound including the area over the patella may be treated by local wound care and skin grafting. However, necrosis over the tibial tubercle or patellar tendon requires muscle flap coverage to prevent infection involving the patellar tendon. If the patellar tendon is not viable and the extensor mechanism disrupted, the medial gastrocnemius flap can also be used to augment the extensor mechanism. The tendon of the gastrocnemius is repaired to the quadriceps tendon maintaining continuity between the tibia and extensor mechanism.
In 14 cases the operations were indicated in reason of spontaneous skin necrosis or defects. These operations were: amputation with or without flap in 3 cases, wound revision in 6 cases, wound revision and flap in 5 cases (including skin transplantation in 3 of these patients).
Seven of 14 patients in the group with spontaneous skin necrosis healed uneventfully after operation. Two patients had consecutive wound infections that caused a longer healing period of 5 months; another patient also had a longer healing period but his wounds healed shortly after he quit smoking. Four patients had necrosis/infections, which required additional surgery.
Nowadays, autologous platelet-rich plasma is used commonly in wound treatment. However, platelet gel, which was derived from allogeneic platelet-rich plasma (PRP) [1,2], has never been studied about efficacy in vivo or animal models. We aimed to determine efficacy of allogeneic platelet-gel on wound healing in rats by comparing with untreated, antibiotic-gel (Mupirocin 2%) treated and gel (sodium carboxymethylcellulose(NaCMC))-treated control. Fresh frozen plasma was centrifuged at 1200-G for 15 minutes to extract PRP which would be freeze-dried at −70°c, sterilized with gamma ray of Cobalt source 25 kGy and stored at −70°c. Then, processed freeze-dried PRP was mixed with gel base (NaCMC) as in form of allogeneic platelet-gel concentrated 30 mg/1g by sterilization process (table 1). Full-thickness of 6-mm-diameter skin punch biopsies were performed on 18 female Wistar rats which each rat had four wounds at back. Each wound was applied with untreated care, antibiotic-gel, NaCMC-gel and platelet-gel, respectively. Wound healing was studied from day 0–12. Animals were sacrificed with wound tissues removal on day 3, 7, 12 post-biopsy. Digital planimetric measurement device (VISITRAK, Smith and Nephew) was used in evaluation of total wound area on day 0, 3, 7, 12 post-biopsy. Histopathological changes of wound healing were studied, using 4-μm thickness section with haematoxylin-eosin (H&E) and Masson's trichrome-stain, under light microscope.Introduction
Methods
Our previous study has revealed that silver nanoparticles (AgNPs) have potential to promote wound healing by accelerated re-epithelization and enhanced differentiation of fibroblasts. However, the effect of AgNPs on the functionality of repaired skin is unknown. The aim of this study was to explore the tensile properties of healed skin after treatment with AgNPs. Immunohistochemical staining, quantitative assay and scanning electron microscopy (SEM) were used to detect and compare collagen deposition, and the morphology and distribution of collagen fibers. Our results showed that AgNPs improved tensile properties and led to better fibril alignments in repaired skin, with a close resemblance to normal skin. Based on our findings, we concluded that AgNPs were predominantly responsible for regulating deposition of collagen and their use resulted in excellent alignment in the wound healing process. The exact signaling pathway by which AgNPs affect collagen regeneration is yet to be investigated.
The Cincinnati incision is widely utilized in clubfoot surgery and allows excellent access to the medial, lateral and posterior structures involved. Closure of the skin at the end of the procedure without undue tension may be difficult. Wound necrosis and excessive scarring may occur and may lead to inadequate correction. One alternative is to splint the foot in an initial equines position post-operatively with repeat cast changes to achieve optimal position once soft tissue swelling has decreased. A further method is to leave the wound open and allow it to granulate. The healing and final cosmetic appearance of wounds allowed to heal by granulation following the Cincinnati incision were reviewed. We reviewed 14 feet in 10 patients who had undergone partial closure of the Cincinnati incision following peritalar release. The majority of the children were male and the average age at surgery was 28 weeks. All corrections were performed as primary procedures on patients with idiopathic CTEV. At the end of the procedure an above-knee plaster was applied. The plaster was changed weekly in the outpatients department until the wound had healed. Patients were maintained in plaster for 12 weeks. All final wounds were cosmetically acceptable both to the surgeon and the parents. The widest scar was 3 mm and the average time to heal four weeks. No infection had occurred although two wounds were treated for overgranulation. Partial wound closure of the Cincinnati incision avoids undue tissue tension and allows a fully corrected position of the foot to be maintained at the end of the initial procedure. A second anaesthetic to obtain further correction is therefore avoided. Partial wound closure leaves cosmetically acceptable scarring with minimal complications. Parents should be warned about the initial appearance of the wound but may be reassured regarding final outcome.
Rivaroxaban is the first licensed oral direct inhibitor of factor Xa. Recent studies from the RECORD trials suggest rivaroxaban has superior efficacy compared to enoxaparin in preventing venous thromboembolism (VTE) with no significant increase in the major bleeding risk. Concerns remain regarding the incidence of minor bleeding, consequent delayed wound healing and subsequent risk of infection. The aim of this observational study was to assess the incidence of post-operative complications in patients receiving either rivaroxaban or enoxaparin thromboprophylaxis following elective hip and knee arthroplasty. 258 patients undergoing elective total hip or knee arthroplasty within one NHS Trust were included. 202 subjects (mean age 70.7 years ± 10.0, 43% male) received a daily dose of 10mg of oral rivaroxaban and 56 (mean age 70.9 years ± 9.8, 39% male) had a daily subcutaneous injection of 40 mg of enoxaparin as thromboprophylaxis. Endpoints included VTE (deep vein thrombosis and pulmonary embolism), haemorrhagic wound complications, hospital re-admission, requirement for blood transfusion, minor and major bleeding and death.Introduction
Methods