We performed a prospective, blind, controlled study on wound infection after implant surgery involving 41 procedures in patients infected with the human immunodeficiency virus (HIV) and 141 in HIV-negative patients. The patients were staged clinically and the CD4 cell count determined. Wound infection was assessed using the asepsis wound score. A risk category was allocated to account for presurgical contamination.

In HIV-positive patients, with no preoperative contamination, the incidence of wound infection (3.5%) was comparable with that of the HIV-negative group (5%; p = 0.396). The CD4 cell count did not affect the incidence of infection (r = 0.16). When there was preoperative contamination, the incidence of infection in HIV-positive patients increased markedly (42%) compared with that in HIV-negative patients (11%; p = 0.084).

Our results show that when no contamination has occurred implant surgery may be undertaken safely in HIV-positive patients.

Tendinopathy is a tendon pathology often resulting from a failed healing response to tendon injury. Activated protein C (APC) is a natural anti-coagulant with anti-inflammatory and wound healing promoting functions, which are mainly mediated by its receptors, endothelial protein C receptor (EPCR) and protease activated receptors (PARs). This study aimed to determine whether APC stimulates tenocyte healing and if so, to assess the involvement of the receptors. Mouse-tail tenocytes were isolated from 3-week-old wild type (WT), PAR- 1 knockout (KO) and PAR-2 KO mice. The expression of EPCR, PAR-1 and −2 and the effect of APC on tenocytes tendon healing and the underlying mechanisms were investigated by Reverse transcription real time PCR, western blot, 3- (4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay, zymography, and scratch wound healing/ migration assay. When compared to WT cells, PAR-1 KO tenocytes showed increased cell proliferation (3.3-fold, p<0.0001), migration (2.7-fold, p<0.0001) and wound healing (3-fold, p<0.0001), whereas PAR-2 KO cells displayed decreased cell proliferation (0.6-fold, p<0.05) and no change in cell migration or wound healing. APC at 1 μg/ml stimulated WT and PAR-1 KO tenocyte proliferation (~1.3, respectively, p<0.05) and wound healing (~1.3-fold, respectively, p<0.05), and additionally promoted PAR1-KO cell migration (1.4-fold, p<0.0001). APC only increased the migration (2-fold, p<0.05) of PAR-2 KO tenocytes. The activation of AKT, extracellular signal-regulated kinase (ERK)-2, and glycogen synthase kinase (GSK)-β3, the intracellular molecules that are associated with cell survival/growth, and matrix metalloproteinase (MMP)-2 that is related to cell migration and wound healing, were increased in all three cell lines in response to APC treatment. These findings show that PAR-1 and PAR-2 act differentially in tenocyte proliferation/migration/wound healing. APC likely promotes tenocyte proliferation/ wound healing via PAR-2, not PAR-1

Aim. As the number of performed total hip arthroplasties (THA) and total knee arthroplasties (TKA) has increased over the years, revision surgeries are expected to increase as well. Revision surgeries are associated with a longer operating room time, prolonged length of stay (LOS), and more frequent complications. Postoperative hematomas are a major reason for wound healing disturbances and periprosthetic joint infections (PJI). We aimed to systematically assess the use and safety of a microporous polysaccharide hemosphere (MPH) in revision THA and TKA. We focused on the risk reduction of further revision surgeries in case of wound healing disorders and hematoma, transfusion of packed red blood cells (PRBC), loss of hemoglobin (hb) and mean LOS following the use of MPH. Method. Our prospective study includes 89 patients who underwent revision surgery after THA and TKA with application of MPH and were compared to 102 patients who did not receive MPH and underwent revision surgery after THA and TKA. Five grams of MPH. 1. were applied periarticular before fascia closure and to the subcutaneous soft tissue. The follow-up was conducted in daily clinical visits during the inpatient stay and three months postoperatively in our outpatient clinic. Repeated revision surgery was performed in case of prolonged secretion (>10 days) or clinical suspicion of infection. After matching the cohorts the outcomes were statistically analyzed using paired methods. Results. A significantly lower odds ratio for repeat revisions was found for the MPH cohort (OR=0.312; 95%-CI 0.090, 0.893; p=0.027). Differences between pre- and postoperative hb levels, LOS and transfusions of PRBC did not reach significance. No intra- or postoperative complications to MPH occurred. Moreover, no infection relapse occurred after applying MPH. Conclusions. Routine use of MPH in revision arthroplasty management after TKA and THA appears to be safe and an effective way to support hemostasis, with no observed adverse events related to MPH use. There were noticeably less hematomas and revision surgeries in the MPH group. 1. Arista BD, Franklin Lakes, NJ, USA

Introduction. We aimed to determine whether there are differences in patient-reported quality of life (QoL) outcome between local flap versus free flap. Materials and Methods. All patients admitted with lower limb open fractures were retrospectively reviewed. Patient notes were assessed for demographics, time to fracture union, wound healing and patient-reported QoL with EQ-5D-5L, alongside a novel flap assessment tool. Results. A total of 40 patients had flap reconstruction of their lower limb injury; 23 local flap (Group I) and 17 free flaps (Group II). The average length of follow-up was 33.8 months. Group I - 10 revisions of flaps (43.5%) and 14 surgical complications (60.9%). Fracture union was 171 days and wound healing 130 days. EQ-5D index and EQVAS scores were 0.709 and 79.3, respectively. Group II – 8 revision of flaps (47.1%) and 12 surgical complications (70.6%). Fracture union was 273 days and wound healing 213 days. EQ-5D index and EQ-VAS scores were 0.525 and 57.2, respectively. Aesthetic appeal - 48% Group I vs. 66% Group II. Significant differences were found between the two flap groups with higher scores for daily living in Group I (p–0.007) compared to higher overall flap ratings in Group II (p–0.049). Both groups were comparable in terms of complications, while flap congestion and dehiscence were more common with free flaps. statistical interrogation did not elicit significance (p > 0.05). Conclusions. Local flap and free flap techniques offer distinct advantages. Local flaps have a better surgical outcome and patient-reported QoL in the first few years post soft tissue reconstruction. Differences between local and free reconstructive techniques in terms of patient health and function are ameliorated in the longer term

Impaired bone healing biology secondary to soft tissue deficits and chemotherapy contribute to non-union, fracture and infection following limb salvage surgery in Osteosarcoma patients. Approved bone healing augments such as recombinant human bone morphogenetic protein-2 (rhBMP-2) have great potential to mitigate these complications. rhBMP-2 use in sarcoma surgery is limited, however, due to concerns of pro-oncogenic signalling within the tumour resection bed. To the contrary, recent pre-clinical studies demonstrate that BMP-2 may induce Osteosarcoma differentiation and limit tumour growth. Further pre-clinical studies evaluating the oncologic influences of BMP-2 in Osteosarcoma are needed. The purpose of this study is to evaluate how BMP-2 signalling affects Osteosarcoma cell proliferation and metastasis in an active tumour bed. Two Osteosarcoma cell lines (143b and SaOS-2) were assessed for proliferative capacity and invasion. 143b and SaOS-2 cells were engineered to upregulate BMP-2. In vitro proliferation was assessed using a cell viability assay, motility was assessed with a scratch wound healing assay, and degree of osteoblastic differentiation was assessed using qRT-PCR of Osteoblastic markers (CTGF, ALP, Runx-2 and Osx). For in vivo evaluation, Osteosarcoma cells were injected into the intramedullary proximal tibia of immunocompromised (NOD-SCID) mice and local tumour growth and metastases were assessed using weekly bioluminescence imaging (BLI) and tumour volume measurements for 4–6 weeks. At the experimental end point we assessed radiographic tumour burden using ex-vivo micro-CT, as well as tibial and pulmonary gross and histologic pathology. SaOS-2 was more differentiated than 143b, with increased expression of Runx-2 (p = 0.009), Osx (p = 0.004) and ALP (p = 0.035). BMP-2 upregulation did not stimulate an osteoblast differentiation response in 143b, but stimulated an increase in Osx expression in SaOS-2 (p = 0.002). BMP-2 upregulation in 143b cells resulted in increased proliferation in vitro (p = 0.014), faster in vitro wound healing (p = 0.03), significantly increased tumour volume (p = 0.001) with enhanced osteolysis detected on micro-CT, but did not affect rates of lung metastasis (67% vs. 71%, BMP-2 vs. Control). BMP-2 over-expression in SaOS-2 cells reduced in vitro proliferation when grown in partial osteogenic-differentiation media (p < 0.001), had no effect on in vitro wound healing (p = 0.28), reduced in vivo SaOS-2 tumour burden at 6 weeks (photon counts, p < 0.0001), decreased tumour-associated matrix deposition as assessed by trabecular thickness (p = 0.02), and did not affect rates of lung metastasis (0% vs. 0%). Our results indicate BMP-2 signalling incites a proliferative effect on a poorly differentiated Osteosarcoma cell line (143b), but conditionally reduces proliferative capacity and induces a partial differentiation response in a moderately-differentiated Osteosarcoma cell line (SaOS-2). This dichotomous effect may be due to the inherent ability for Osteosarcoma cells to undergo BMP-2 mediated terminal differentiation. Importantly, these results do not support the clinical application of BMP-2 in Osteosarcoma limb salvage surgery due to the potential for stimulating growth of poorly differentiated Osteosarcoma cells within the tumour bed. Additional studies assessing the effects of BMP-2 in an immune-competent mouse model are ongoing

The incidence of PJI in knee replacements is 2.8% and slightly lower with hip replacement surgery. PJI make up 15% (or even more) of knee revisions. To combat PJI, antibiotic laden bone cement has been used for many decades, but antibiotic stewardship dictates more prudent management of antimicrobials. Projected increase in infection rate, due to increased surgery and latent infection to be almost 5-fold up to 2035. Biofilm is a complex structure of bacteria and polysaccharide matrix and, is recognised as a major component in PJI and other orthopaedic infections. Biofilm is responsible for high incidence of resistance to antimicrobials and ineffective host immune response. Method. Stabilized hypochlorous acid has been reported to have a rapid kill rate on all pathogens, including MDR pathogens associated with chronic and acute wound infections. It destroys biofilm on contact, is not cytotoxic, reduces inflammation and stimulates wound healing. 0,038% of Hypochlorous acid was used as prophylaxis against infection and to treat PJI. We report on our experience with hypochlorous acid as a wound irrigation as prophylaxis against infection (more than 600 cases) and for PJI. We also report on a University study where a head to head analysis was done on the anti-biofilm efficacy between hypochlorous acid 0,038% (Trifectiv Surgical Wound Irrigation) and Product X (an industry-standard product for the prevention and treatment of biofilm infection. Hypochlorous acid offers a valuable addition to the armamentarium of wound antiseptics, with added anti-inflammatory value. An in vitro study demonstrated superior efficacy against biofilm when compared to Product X

Objective. Carpal tunnel release surgery is a commonly performed procedure for alleviating symptoms of median nerve compression and restoring hand function. With pressure on theatre time these procedures are now commonly performed in a step-down out-patient facility under local anaesthetic. The choice of suture for skin closure in this procedure can impact the quality of wound healing, patient outcomes and the follow-up required however the question of the best type of suture remains unanswered. The purpose of this study was to compare the outcomes of absorbable and non-absorbable sutures using a randomised control trial design. Methods. Eighty patients diagnosed with bilateral carpal tunnel syndrome were enrolled and underwent outpatient carpal tunnel release surgery under local anaesthetic in a staged fashion. Random number generation was used to assign each hand to receive interrupted nylon or Vicryl Rapide sutures. Pre-operative data collection included patient demographics, ASA, inflammatory conditions, smoking status as well as a Boston Carpal Tunnel Questionnaire (BCTQ) for each hand. Patients were followed up at 2 and 6 weeks after each operation and the BCTQ was repeated along with the Patient and Observer Scar Assessment Scale and the VAS score for wound discomfort. This study has approval from the DHB ethics committee, Local Iwi, HDC and ANZ Clinical Trials:ACTRN12623000100695. Results. Statistical analysis assessed patient preference and the scores between the groups. Multi-variate analysis was performed to assess the factors that may be contributing to patient choice. Conclusion. Insights into patient preference and clinical outcomes associated with absorbable sutures and non-absorbable sutures in the setting of out-patient surgery are discussed

Impaired bone healing biology secondary to soft tissue deficits and chemotherapy contribute to non-union, fracture and infection following limb salvage surgery in Osteosarcoma patients. Approved bone healing augments such as recombinant human bone morphogenetic protein-2 (rhBMP-2) have great potential to mitigate these complications. rhBMP-2 use in sarcoma surgery is limited, however, due to concerns of pro-oncogenic signalling within the tumour resection bed. To the contrary, recent pre-clinical studies demonstrate that BMP-2 may induce Osteosarcoma differentiation and limit tumour growth. Further pre-clinical studies evaluating the oncologic influences of BMP-2 in Osteosarcoma are needed. The purpose of this study is to evaluate how BMP-2 signalling affects Osteosarcoma cell proliferation and metastasis in an active tumour bed. Two Osteosarcoma cell lines (143b and SaOS-2) were assessed for proliferative capacity and invasion. 143b and SaOS-2 cells were engineered to upregulate BMP-2. In vitro proliferation was assessed using a cell viability assay, motility was assessed with a scratch wound healing assay, and degree of osteoblastic differentiation was assessed using qRT-PCR of Osteoblastic markers (CTGF, ALP, Runx-2 and Osx). For in vivo evaluation, Osteosarcoma cells were injected into the intramedullary proximal tibia of immunocompromised (NOD-SCID) mice and local tumour growth and metastases were assessed using weekly bioluminescence imaging and tumour volume measurements for 4–6 weeks. At the experimental end point we assessed radiographic tumour burden using ex-vivo micro-CT, as well as tibial and pulmonary gross and histologic pathology. SaOS-2 was more differentiated than 143b, with significantly increased expression of the Osteoblast markers Osx (p = 0.004) and ALP (p = 0.035). BMP-2 upregulation did not stimulate an osteoblast differentiation response in 143b, but stimulated an increase in Osx expression in SaOS-2 (p = 0.002). BMP-2 upregulation in 143b cells resulted in increased proliferation in vitro (p = 0.014), faster in vitro wound healing (p = 0.03), significantly increased tumour volume (p = 0.001) with enhanced osteolysis detected on micro-CT, but did not affect rates of lung metastasis (67% vs. 71%, BMP-2 vs. Control). BMP-2 over-expression in SaOS-2 cells reduced in vitro proliferation when grown in osteogenic-differentiation media (p < 0.001), had no effect on in vitro wound healing (p = 0.28), reduced in vivo SaOS-2 tumour burden at 6 weeks (photon counts, p < 0.0001), decreased tumour-associated matrix deposition as assessed by trabecular thickness (p = 0.02), but did not affect rates of lung metastasis (0% vs. 0%). Our results indicate BMP-2 signalling incites a proliferative effect on a poorly differentiated Osteosarcoma cell line (143b), but conditionally reduces proliferative capacity and induces a partial differentiation response in a moderately-differentiated Osteosarcoma cell line (SaOS-2). This dichotomous effect may be due to the inherent ability for Osteosarcoma cells to undergo BMP-2 mediated terminal differentiation. Importantly, these results do not support the clinical application of BMP-2 in Osteosarcoma limb salvage surgery due to the potential for stimulating growth of poorly differentiated Osteosarcoma cells within the tumour bed. Additional studies assessing the effects of BMP-2 in an immune-competent mouse model are ongoing

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

Introduction. The condition of the soft tissues surrounding an ankle fracture influences timing and treatment of injuries. Conventional treatment used an open approach to facilitate anatomical reduction and rigid internal fixation. Intramedullary devices for fibular fractures provide a safe alternative in patients in which the condition of the soft tissue envelope or the patient's co-morbidities may benefit from a less invasive approach. We compared outcomes for patients treated with open reduction internal fixation (ORIF) with those undergoing treatment with fibular nails (FN). Methods. 13 consecutive patients treated with fibular nails (FN) were compared with 13 age-matched patients that underwent open reduction and internal fixation (ORIF). All patients were followed to union. Study outcomes were time from admission to surgery, length of stay, wound failure, implant failure, revision surgery, OMAS and SF-36. Results. There was no difference in age or sex distribution between groups. There was no difference in OMAS at 1 year (83 ± 9 in FN group; 80± 21 in ORIF group) and SF-36 (94 ± 11 and 90 ± 20). There were 2 implant failures in the ORIF group and none in the FN group. There was one wound failure in the ORIF group and none in the FN group. Patients treated with FN had a shorter time to surgery (1 day ± 24 hours vs 3 days ± 24 hours) and shorter length of stay (1 day ± 24 hours vs 4 days ± 96 hours). Conclusion. FN is a safe method to treat patients with displaced distal fibular fractures that may have a poor soft tissue envelope and risk factors for wound healing. FN reduces the time to surgery and overall length of stay compared with similar patients treated with conventional ORIF

Aim. Treatment of complicated wound healing after total joint arthroplasty is controversial. What exactly constitutes prolonged wound drainage is matter of debate and recommendations to manage it vary considerably. Nonoperative measures are often recommended. If drainage persists, surgery may be indicated. To further intricate decision-making, differentiating superficial from deep surgical site infection is also controversial and inherently complex. Specific cutoffs for synovial fluid leukocyte count and blood C-reactive protein (CRP) in the acute stage have been suggested as a way to superficial infection requiring superficial wound washout from deep infection requiring a formal debridement, antibiotics and implant retention (DAIR) procedure. The goal of this study is to analyze clinical and laboratory findings of an institutional protocol of “aggressively” proceeding with formal DAIR in all patients with complicated wound healing. Method. Our indications for DAIR in suspected acute postoperative periprosthetic joint infection (PJI) are: 1)prolonged wound drainage and CRP upward trend after day-3; 2)persistent wound drainage by day-10 regardless of CRP; 3)wound healing disturbance (e.g. “superficial” infection, “superficial” skin necrosis) anytime in early postoperative weeks. We retrospectively evaluated patients undergoing DAIR in the first 60 postoperative days between 2014–2018. Patients without multiple deep tissue cultures obtained intraoperative were excluded. Deep infection was defined by at least two positive deep tissue cultures or one positive deep culture and positive leukocyte count (>10,000 cells/mL or >90% PMN). Results. A total of 44 DAIR procedures were included. Deep infection was confirmed in 79.5%(35/44) of cases. Mean CRP in infected cases was 93mg/L with 63%(19/30) of them below the 100 mg/L threshold. Unfortunately, only a small proportion of cases (10/44) had synovial fluid leukocyte counts available. Mean leukocyte count was 15,558 cells/mL and mean proportion of PMN was 65.3%. Of these ten, six confirmed deep infections were below the proposed >10,000 cells/mL or >90% PMN cutoff. Conclusions. Early diagnosis of acute postoperative PJI is often hampered by its very subtle presentation. This study confirms that more often than not, deep infection is present when facing complicated wound healing after total joint arthroplasty, supporting our institutional “aggressive” protocol. We have been surprised by the number of confirmed acute PJI with low blood CRP levels and low synovial leukocyte counts. We hypothesize that the proposed acute PJI specific thresholds may lead to misinterpret a significant proportion of cases as superficial infections thus compromising timely intervention. The findings of this study lack confirmation in larger cohorts

Postoperative surgical site infection in patients treated with lumbosacral fusion has been believed to be caused by perioperative contamination (Perioperative Inside-Out infections) in patients with comorbidities. With the proximity of these incisions to the perianal region and limited patient mobility in the early post-operative period, local contamination from gastrointestinal and/or urogenital flora (Postoperative Outside-In infections) should be considered as a major source of complication. A single center, retrospective review of adult patients treated with open posterior lumbosacral fusions between January 2014 and January 2021. We aimed to identify common factors in patients experiencing deep postoperative infections. Oncological, minimally invasive, primary infection, and index procedures carried out at other institutions were excluded. We identified 489 eligible patients, 20 of which required debridement deep to the fascia (4.1%). Mean age (62.9 vs 60.8), operative time (420 vs 390 minutes), estimated blood loss (1772 vs 1790 mL) and median levels fused (8.5 vs 9) were similar between the infected and non-infected groups. There was a higher percentage of deformity patients (75% vs 29%) and increased BMI (32.7 vs 28.4) in the infected group. The mean time from primary procedure to debridement was 40.8 days. Four patients showed no growth on culture. Three showed Staphylococcus species (Perioperative Inside-Out infections) requiring debridement at a mean of 100.3 days (95%CI 0- 225 days). Thirteen patients showed infection with intestinal or urogenital pathogens (Postoperative Outside-In infections) requiring debridement at a mean of 20.0 days (95%CI 9-31 days). Postoperative Outside-In infections led to debridement 80.3 days earlier than Perioperative Inside-Out infections (p= 0.007). In this series, 65% of deep infections were due to early local contamination by gastrointestinal and/or urogenital tracts pathogens. These infections were debrided significantly earlier than the Staphylococcus species infections. Due to the proximity of the incisions to the perianal region, there should be increased focus on post-operative local wound management to ensure these pathogens are away from the wound during the critical stages of wound healing

Aim. Decubitus ulcers are found in approximately 4.7% of hospitalized patients, with a higher prevalence (up to 30%) among those with spinal cord injuries. These ulcers are often associated with hip septic arthritis and/or osteomyelitis involving the femur. Girdlestone resection arthroplasty is a surgical technique used to remove affected proximal femur and acetabular tissues, resulting in a substantial defect. The vastus lateralis flap has been employed as an effective option for managing this dead space. The aim of this study was to evaluate the long-term outcomes of this procedure in a consecutive series of patients. Method. A retrospective single-center study was conducted from October 2012 to December 2022, involving 7 patients with spinal cord injuries affected by chronic severe septic hip arthritis and/or femoral head septic necrosis as a consequence of decubitus ulcers over trochanter area. All patients underwent treatment using a multidisciplinary approach by the same surgical team (orthopedic and plastic surgeons) along with infectious disease specialists. The treatment consisted of a one-stage procedure combining Girdlestone resection arthroplasty with unilateral vastus lateralis flap reconstruction, alongside targeted antibiotic therapy. Complications and postoperative outcomes were assessed and recorded. The mean follow-up period was 8 years (range 2-12). Results. Of the 7 patients, 5 were male and 2 were female, with a mean age of 50.3 years at the time of surgery. Minor wound dehiscence occurred in 28.6% of the flap sites, and 2 patients required additional revisional procedures—one for hematoma and the other for bleeding. There were no instances of flap failure, and complete wound healing was achieved in an average of 32 days (range 20-41), with the ability to load over the hip area. No cases of infection recurrence or relapse were observed. Conclusions. An aggressive surgical approach is strongly recommended for managing chronic hip septic arthritis or proximal femur osteomyelitis in patients with spinal cord injuries. A single-stage procedure combining Girdlestone resection arthroplasty with immediate vastus lateralis muscle flap reconstruction proves to be an effective strategy for dead space management and localized antibiotic delivery through the vastus muscle, giving reliable soft tissue coverage around the proximal femur to avoid the recurrence of pressure ulcers. The implementation of a standardized multidisciplinary protocol contributes significantly to the success of reconstruction efforts

Aim. Smoking is known to impair wound healing and to increase the risk of peri-operative adverse events and is associated with orthopaedic infection and fracture non-union. Understanding the magnitude of the causal effect on orthopaedic infection recurrence may improve pre-operative patient counselling. Methods. Four prospectively-collected datasets including 1173 participants treated in European centres between 2003 and 2021, followed up to 12 months after surgery for clinically diagnosed orthopaedic infections, were included in logistic regression modelling with Inverse Probability of Treatment Weighting for current smoking status [1–3]. Host factors including age, gender and ASA score were included as potential confounding variables, interacting through surgical treatment as a collider variable in a pre-specified structural causal model informed by clinical experience. The definition of infection recurrence was identical and ascertained separately from baseline factors in three contributing cohorts. A subset of 669 participants with positive histology, microbiology or a sinus at the time of surgery, were analysed separately. Results. Participants were 64% male, with a median age of 60 years (range 18–95); 16% of participants experienced treatment failure by 12 months. 1171 of 1173 participants had current smoking status recorded. As expected for the European population, current smoking was less frequent in older participants (Table 1). There was no baseline association between Charlson score or ASA score and smoking status (p=0.9, p=1, Chi squared test). The estimated adjusted odds ratio for treatment failure at 12 months, resulting from current smoking at the time of surgery, was 1.37 for all participants (95% CI 0.75 to 2.50) and 1.53 for participants with recorded confirmatory criteria (95% CI 1.14 to 6.37). Conclusions. Smoking contributes to infection recurrence, particularly in people with unequivocal evidence of osteomyelitis or PJI. People awaiting surgery for orthopaedic infection should be supported to cease smoking, not only to reduce anaesthetic risk, but to improve treatment outcomes. Limitations of this study include unmeasured socioeconomic confounding and social desirability bias resulting in uncertainty in true smoking status, resulting in underestimated effect size

Introduction. 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. Methods. 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. Results. Detailed demographic data was presented in Table 1. The average HWES was 5.0 ± 0.8 point. As to the distribution of the HWES, data was shown in Figure 1. Namely, HWES was 3 point in 5 cases, 4 in 29 cases, 5 in 63 cases, and 6 in 42 cases. As any adverse events were not found in each TKA, there were no cases requiring debridement and re-closure of the wound after primary TKA. According to stepwise forward regression test, intraoperative patella eversion and anterior translation of the tibia were entered in this model, while age, Sex, BMI, HbA1C, FTA, surgical time, tourniquet time, patella resurfacing, unidirectional barbed suture and length of skin incision were not entered in the model. The multiple regression analysis in the current study would show the appropriate results, as Durbin-Watson ratio was 1.762. Standardized partial regression coefficient was as follows; 0.57 in anterior translation of the tibia, 0.38 in patella eversion (Table 2). Discussion. The results of the present study would support out hypothesis that operative technique would affect wound healing in primary TKA. Specifically, intraoperative patella eversion and anterior translation of the tibia should be avoided for quality cosmesis of the wound healing in primary TKA. To view tables/figures, please contact authors directly

Currently there is an elevated public awareness of the consequences of nosocomial infection, of which, 14.5% is due to surgical site infection (SSI). Hip fracture patients are at increased risk of SSI due to their age related poor medical health, immune response impairments and decreased capacity of wound healing. Superficial SSI following hip fracture surgery can affect up to 16.9% with deep infection affecting 3.7%. Deep infection represents a major complication, from which hip fracture patients are 4.5 times less likely to survive to discharge and carries a 50% mortality at 1 year, compared to 33% without infection. Treatment requires a prolonged hospital stay, additional diagnostic testing, antibiotic therapy and surgery, resulting in the total cost of treating deep infection to be more than double that of non-infected hip fracture surgery. Wound closure aims to accurately appose the skin edges thereby promoting rapid healing and restoration of the protective dermal barrier. Failure to provide accurate skin apposition can result in delayed wound healing which has been shown to have a 3 fold risk of developing late infection. Importantly, delayed wound healing is reflected by prolonged wound ooze. We hypothesized that skin closure via sutures is better at achieving skin edge apposition than wounds closed with staples, providing more rapid wound healing. We compared staples and sutures for wound closure in hip fracture patients by using ooze duration as an outcome measure for wound healing. Duration of wound ooze was recorded in 170 patients. 65 wounds, closed with sutures, had an average duration of ooze of 1.82 days. 105 wounds, closed with staples, had an average duration of ooze of 4.97 days. This study suggests that sutures are superior to staples with regard to early wound healing in hip fracture patients

Purpose. Adipose derived stem cells have been shown to enhance both wound and bone healing. The stem cells are harvested, purified, cultured and the viability assessed in order to provide adequate cellular yield. The isolation process requires trained laboratory staff, intensive procedures utilizing multiple purification solutions and expensive equipment for culturing and interpretation of viability of the isolated stem cells. The aim of the study was to investigate the effect of simple lipo-aspirate on wound and bone healing. Methodology. This is a prospective, interventional study to investigate the effect of adipocyte extract on wound and bone healing. 9 Young, healthy, large white female pigs were used in the study. Fat was harvested using standard liposuction technique and injected around the defects created. Skin defects were evaluated for secondary wound healing macroscopically and histologically. 3 pigs were used in a pilot study to evaluate the possibility of investigating the effects of lipo-aspirate in bone defects. Results. Histological evaluation shows accelerated secondary wound healing with the treatment of adipose tissue compared to control groups. The thickness of regenerated epidermis, the number of new vascular nests was increased and the wound surface area was decreased in adipose treated wounds. Bacteriology results showed no significant differences. Conclusion. Results indicate a potential benefit in the treatment of wounds with the use of lipo-aspirated extract. The procedure allows for a cost effective method to enhance wound healing in a developing country. Due to the encouraging results in wound healing and osteogenic potential of lipo-aspirate, a pilot study to evaluate lipo-aspirate effects on bone healing has been drawn up. NO DISCLOSURES

The aim of the study was to assess an effectiveness of S53P4 bioglass in reconstruction of postinflammatory bone loss. We have also evaluated wound healing after the surgical dead space management with use of the bioglass. A group of 7 patients with bone loss due to active osteomyelitis and with purulent fistula treated with use of S53P4 bioglass is presented in the paper. All the treated patients were male with mean of age 40,5 years. Mean time of an active inflammatory process with purulent discharge from the wound prior the surgery was 587 weeks. Wound healing pattern with an X-ray evaluation of reconstructed void was performed in postoperative period as well as in 1, 3, 6 and 12 mounth follow-up. In 6 out of 7 cases we did not observed any signs of infection recurrence in 1-year follow-up. Starting from 1-month follow-up inflammatory serum markers remained in their reference values. In all the successfully treated cases wound healing was assessed by two independent surgeons as excellent or good. Starting from 3-month follow-up we have observed gradual blurring of granular bioglass structure on an X-ray scans. In 1 complicated case we observed recurrence of septic inflammatory process with purulent fistula that required revision procedure with removal of the bioglass and extended debridement of inflammatory focus. In this case we have faced posttraumatic malunion of the femur that substantially complicated surgical access to the inflammatory focus during primary procedure. S53P4 bioactive glass is an effective solution in reconstruction of postinflammatory bone loss. Properties of this biomaterial efficiently prevent from focal infection recurrence by inhibiting of bacterial bone growth and reduction of dead space. The product requires however meticulous debridement and the access to a vital bone as a source of osteoblast cells. Underestimation of surgical debridement will likely result in reopening of the fistula due to reinfection. The study group requires further evaluation

Aim. Spinal implant-associated infections (SIAI) require combined surgical and antimicrobial treatment and prolonged hospital stay. We evaluated the clinical, laboratory, microbiological and radiological characteristics and treatment approaches in patients with SIAI. Method. Consecutive adult patients with SIAI treated between 2015 and 2017 were prosepctively included. SIAI was defined by: (i) significant microbial growth from intraoperative tissue or sonication fluid, (ii) intraoperative purulence, secondary wound dehiscence or implant on view, (iii) radiographic evidence of infection and fever (>38°C) without other recognized cause, increasing back pain or neurologic impairment, (iv) peri-implant tissue inflammation in histopathology. Results. A total of 60 patients were included, median age was 66 years (range, 28–91 years), 29 (48%) were males. The most common reason for spinal stabilization was spinal canal stenosis in 20 patients (33%) followed by vertebral degenerative disease in 14 (23%). 31 patients (52%) had one or more previous spine surgeries (range, 1–4 interventions). The anatomic site of spinal instrumentation was lumbar/sacral in 26 (43%), cervical in 23 patients (38%), thoracic in 11 (18%). The median number of fused segments was 5 (range, 1–14). Clinical manifestations included wound healing disturbance in 41 patients (68%), increasing back pain in 15 (25%), neurologic impairment in 12 patients (20%) and fever in 14 (23%). Serum CRP was abnormal (>10mg/l) in 46/59 patients (78%). Most (n=54) infections were postsurgical, 5 were hematogenous and 1 was contiguous. Imaging showed epidural, intraspinal or paravertebral abscess in 21/42 patients (50%), implant failure in 9 (21%) and implant loosening in 3 cases (7%). Monomicrobial infection was observed in 41 (68%), polymicrobial in 16 (27%) patients and culture-negative infection in 3 episodes (5%). Predominant causative pathogens were S. aureus (n=19), coagulase-negative staphylococci (n=18) and gram-negative rods (n=16). Surgery was performed in all patients including debridement and implant retention in 39 patients (65%), partial implant exchange in 10 (17%) and complete exchange in 11 (18%). Antimicrobial treatment included biofilm-active substances in 52 patients (87%). The median duration of antimicrobial therapy was 11,7 weeks (range, 6–12 weeks). 14 patients (23%) recieved suppressive therapy for a median duration of 9 months (range 3–12 months). Conclusions. Most SIAI were seen in lumbar/sacral segments and wound healing disturbance and increasing back pain were the most common manifestations. In 95% the causative pathogen was isolated, predominantly staphylococci. In half of the episodes, abscesses were present. All patients underwent surgery and biofilm-active antibiotics were administered in 87%

Aim. The optimal treatment of displaced intra-articular calcaneal fractures (DIACF) remains controversial. The operative treatment group has better anatomical recovery, functional outcome scores and less pain than non operative treatment patients, but it may lead to a higher incidence of complications, such as delayed wound healing and surgical site infections. The aim of this study was to analyze the prophylactic effect using a biphasic bone substitute (BS) eluting antibiotic on calcaneal implant-related infections. Methods. We conducted a retrospective non-randomized review of all patients with DIACF (type Sanders 2, 3, 4) from 2009 to 2017; 103 calcaneal fractures of 90 patients (13 bilaterally) were treated with plates. All cases received the same systemic antibiotic prophylaxis; BS was used on more complex cases with large bone defect and BS was added with antibiotic on higher risk patients. We collected data including complications: major (deep infections, osteomyelitis) and minor complications (wound dehiscence, superficial infection). We considered the absence of deep infections after 6 months. We compared statistically the outcomes of 3 operative groups: the first was treated with plates only (A), the second with plates and BS (B) and the third with plates added with BS eluting antibiotic (vancomicine or gentamicine) (C). Results. We examined 99 cases (group A: n33, B: n52, C: n14), 4 patients were lost; the mean age was 47,8 years (range 18–83 years). Minimal follow up was 6 months (range: 6 – 42 months). We have observed 8 (8,1%) implant-related infection (A:4, 12,1%; B:4, 7,7%), 2 (2%) superficial infection (B:2, 3,8%), 20 (20,2%) wound healing defects (A:11, 33,3%; B:7, 13,5%; C:2, 14,2%). We found a relevant reduction of the rates in the group C regarding the major complications without a statistic evidence. Conclusion. The three groups are uneven; particularly the group C has a high concentration of more severe risk patients. The low number of cases in the group C, which limited the statistic evidence, represents a second limit. The absence of major infection on group C found in this study, needs larger data to confirm this result. The open surgery has an intrinsic rate of skin complications but the use of BS eluting local antibiotic is an additional tool to manage difficult complex fractures and to prevent implanted-related infection, inhibiting bacterial colonization and biofilm protection, particularly in those patients that have suffered from a minor complication, which could lead to a deep infection