Bacterial skin recolonization in the operating room: comparison between various antisepsis protocols.

BACKGROUND: Surgical site infection (SSI) largely implicates the patient's endogenous skin microbiota. Perioperative disinfection protocols do not follow a general agreement. AIM: To compare antisepsis and skin protection protocols on quantitative analysis of recolonization in the operating room at regular time-steps. The study hypothesis was that one protocol would be more effective than others. METHODS: A single-centre prospective interventional study was conducted between January and June 2019. Healthy volunteers were randomized between protocols and served as their own controls. The protocols began ahead of scheduled orthopaedic surgery with a preoperative shower, mechanical cleansing, application of major antiseptics (alcoholic Bétadine™ 5% or alcoholic chlorhexidine 0.5%), sterile draping, then adhesive draping (3M™ Steri-Drape™ or iodine-impregnated 3M™ Ioban2™). Sampling was by swabbing in the operating room at 30 min intervals up to 90 min after draping. Cultures were performed under aerobic and anaerobic conditions. Qualitative and quantitative (cfu/mL) bacteriology was performed in the laboratory by direct reading on the blood agar plates. FINDINGS: Thirty subjects were included; none was lost to follow-up or excluded from analysis. Bacterial load before manipulation (T0) was significantly higher in males (P < 0.0001) despite a significantly shorter shower-to-sampling interval (P = 0.03). Smoking (P = 0.85), body mass index (P = 0.38), and depilation (P = 0.50) did not significantly affect preoperative load. Mean load increased significantly under all protocols up to T90 min, without significant superiority for any one protocol. Associated Bétadine™/Ioban™ showed the lowest T90 load, and chlorhexidine alone the highest, but without significant difference. Isolates at T0 were predominantly healthy skin commensals: coagulase-negative staphylococci, micrococci, and coryneforms. CONCLUSION: No one protocol demonstrated superiority, whether in immediate bactericidal action or in preventing skin recolonization in the operating room. Further studies are needed to define generally agreed protocols for SSI risk management.

Collection and reconstruction after harvesting donor tissues from the musculoskeletal system: Technique specific to the lower limbs.

The lack of available musculoskeletal grafts in France forces us to import a very large quantity of these tissues to use in complex reconstruction procedures. The goal of this article is to describe methods for collecting donor tissues from the musculoskeletal system and for reconstructing the harvested areas. We also provide a summary of the collection procedures performed, harvested grafts and available tissues. While tissue collection requires a significant time investment, the emergence of dedicated teams may be a solution for increasing the number and quality of human musculoskeletal allograft tissues.

Usefulness of sonication for diagnosing infection in explanted orthopaedic implants.

BACKGROUND: Orthopaedic implant infection is a rare but serious complication whose optimal treatment requires an accurate microbiological diagnosis. The objective of this study was to determine whether culturing sonicated explants improved sensitivity compared to culturing standard sonicated soft-tissue samples. HYPOTHESIS: Cultures of explant sonication fluid are more sensitive than cultures of soft-tissue sonication fluid in patients with implant infection. METHODS: This single-centre retrospective study included all sonication fluid samples from implants explanted in orthopaedic surgery theatres for any reason. The microbiological results of the implant sonication fluid cultures were compared to those of cultures of sonicated soft-tissue and bone samples taken during the same procedure. The primary evaluation criterion was the difference in microorganisms recovered from explant sonication fluids versus fluid/tissue cultures. RESULTS: The study included 187 explants removed between September 2009 and June 2015. Of the definite infections, 83% were identified by explant sonication, 86% by fluid/tissue cultures, and 91% by both techniques combined. Explant sonication recovered causative organisms in 10 patients with definite infection but negative fluid/soft tissue cultures. Antibiotic therapy prior to explantation was associated with lower sensitivity of explant sonication (57% vs. 67% for fluid/soft tissue cultures). CONCLUSION: Explant sonication improved the diagnosis of infection when combined with fluid/soft tissue cultures. LEVEL OF EVIDENCE: IV, retrospective single-centre study.

Complications with cement spacers in 2-stage treatment of periprosthetic joint infection on total hip replacement.

INTRODUCTION: The aim of the present study was to assess our management of infected total hip replacement in indications for 2-stage surgical treatment according to current guidelines when a cement spacer has been used. The study hypothesis was that the complications rate related to cement spacers is low. MATERIAL AND METHOD: A single-center retrospective study included 26 patients receiving a spacer between the two stages of total hip replacement, over a 5 year period. We analyzed the spacers used, mechanical complications, infectious complications and the second stage of surgery. RESULTS: During the interval between surgeries, in the 26 patients, there were 19 spacer-related mechanical complications (73% of patients): 11 dislocations (42.3%), 5 spacer fractures (19.2%), 5 femoral bone lyses or fractures (19.2%) and 3 acetabular lyses or fractures (11.5%). In 4 cases, complications were associated. The greater the femoral offset of the spacer, the more frequent were femoral bone lyses or fractures (p=0.05), and the smaller the offset the more frequent were acetabular lyses or fractures (p=0.05). The rates of mechanical complications (p=0.003) and spacer fracture (p=0.02) were significantly greater in older patients. There were 4 cases of reinfection (19%): i.e., an 81% treatment success rate. One reinfection implicated a new bacterium: methicillin-susceptible Staphylococcus aureus. The second surgical stage was significantly longer in complex bipolar revision (p=0.009). CONCLUSION: The present results showed a high risk of spacer-related complications, and thus the importance of selection of patients liable to derive real benefit and those for whom a Gilderstone procedure would be preferable. LEVEL OF EVIDENCE: IV, retrospective study.

Does using a polyethylene RM press-fit cup modify the preparation of the acetabulum and acetabular offset in primary hip arthroplasty?

INTRODUCTION: When performing total hip arthroplasty (THA), it is important to maintain the femoral and acetabular offsets to ensure good joint stability and to restore the function of the hip abductor muscles. In our practice, we mainly use a lateralized stem and hollow out the acetabulum to the quadrilateral plate to accommodate a press-fit polyethylene cup. However, the repercussions of this preparation method, which is driven by the cup's design, are not known. We carried out a retrospective study to assess: (1) the changes in the femoral and acetabular offset; (2) the height of the center of rotation; and (3) the repercussions on wear. HYPOTHESIS: We hypothesized there would be no significant differences between the preoperative and postoperative femoral and acetabular offsets. PATIENTS AND METHODS: We reviewed 88 primary THA cases performed with the RM Pressfit™ cup that had a minimum of 5 years' follow-up. A lateralized self-locking Muller-type cemented femoral stem was used in 92.0% of cases and a standard stem in 8.0%. Measurements were done on plain radiographs with MHP™ and Mesurim Pro™ software. The average follow-up was 6.5 years (5-8). RESULTS: On average, the acetabular offset was reduced by 2.75mm±5.9 mm (range: -17.5 to +10.6 mm) (P<0.001) and the femoral offset was increased by 0.01mm±5.5 mm (range: -17.8 to +11.0 mm) (P=0.99). In terms of total offset, medialization of 2.74mm±7 mm (range: -17.7 to +18.2mm) was found (P=0.001). The acetabular center of rotation was on average 4.77mm±5.1 mm higher (P<0.001). The mean annual wear at the more recent follow-up (min.: 5 years) was 0.068mm (range: 0.01 to 0.25mm) per year. The wear was not impacted by having more than 5mm change in offset. DISCUSSION: Measurements of acetabular offset revealed statistically significant medialization due to the type of implant used and the surgical technique. The anatomical technique consists of positioning the cup in subchondral bone without contacting the quadrilateral plate. This preserves bone stock, which may be useful later on if the cup is revised, particularly in younger patients. Conversely, the femoral offset did not change significantly, despite the use of lateralized stems in 92.0% of cases. We measured an annual wear rate of 0.068mm per year, which is lower than in other published studies, possibly because our patient population was older. LEVEL OF EVIDENCE: IV, retrospective study.

Acetabular bone defects in THA revision: Reconstruction using morsellised virus-inactivated bone allograft and reinforcement ring. Seven-year outcomes in 95 patients.

BACKGROUND: Acetabular cup loosening is among the main reasons for revision total hip arthroplasty (THA). The implantation of a cryopreserved morsellised bone allograft is a reference method for filling bone defects. However, the outcomes of bone grafts treated with viral inactivation and secured into the host bone (notably using a reinforcement device) are unclear. We therefore retrospectively reviewed cases of acetabular revision with morsellised bone allograft implanted into a reinforcement ring for acetabular revision to assess: (1) clinical survival of the acetabular implant (time to new revision with acetabular component removal), (2) radiological implant survival, (3) and bone graft osseointegration evaluated using Oswestry's criteria. HYPOTHESIS: Virus-inactivated bone allografts provide similar outcomes to cryopreserved allografts. MATERIAL AND METHODS: From 2004 to 2009, 95 patients underwent acetabular revision. There were 60 (63%) females and 35 (37%) males with a mean age of 71.7 years (range: 44.2-90 years). Over 90% of patients had bone defects type 2 or higher in the AAOS classification. Each patient was evaluated after at least 5 years, by an examiner who had not been involved in the revision and who determined the Postel-Merle d'Aubigné (PMA) score and patient satisfaction. We assessed the clinical survival of the acetabular implant (time to new revision with acetabular implant removal), radiological implant survival (migration>5mm, active radiolucent line, failure of graft osseointegration, or reinforcement ring failure), and allograft osteointegration evaluated using Oswestry's criteria. RESULTS: After a mean follow-up of 7years (range: 5.2-10years), 7 (7.4%) patients had been lost to follow-up and 3 (3.4%) had required surgical revision, after 3 to 73 months (for aseptic loosening in 2 cases and infection in 1 case). The estimated 10-year survival rate was 96.2% (95% confidence interval [95%CI]: 88.2-98.7). The mean PMA score at last follow-up had increased significantly, by 2.8 points (p<0.05), to 13.8 (95%CI: 78.4-88.1). Of the 88 re-evaluated patients, 78 (89%) were satisfied or very satisfied. The overall radiological survival rate was 84.5% (95%CI: 78.4-88.1) after a mean of 5.9 years (range: 0.5-10). Allograft osseointegration was satisfactory (Oswestry score≥2) in 95.8% of patients. DISCUSSION: In our population, allografts previously subjected to virus inactivation and implanted into a reinforcement ring produced outcomes similar to those reported previously with cryopreserved allografts. LEVEL OF EVIDENCE: IV, retrospective case-series study.

Opening-wedge high tibial osteotomy with a secure bone allograft (Osteopure™) and locked plate fixation: Retrospective clinical and radiological evaluation of 69 knees after 7.5years follow-up.

BACKGROUND: Medial opening-wedge high tibial osteotomy (OWHTO) provides reliable and long-lasting benefits, despite the wide range of wedge-filling and internal-fixation techniques used. The purpose of this work was to assess the clinical and radiological outcomes in a case-series of OWHTO performed using a secure bone allograft and locked plate fixation. HYPOTHESIS: The clinical and radiological outcomes of OWHTO with a high-safety bone allograft and locked plate fixation are similar to those reported in previous case-series studies. MATERIALS AND METHODS: A single-centre retrospective design was used to study 69 knees in 64 patients with a mean age of 51.8years (31-53years) and a preoperative hip-knee-ankle (HKA) angle of 173° (165°-180°). The wedge was filled with secure Osteopure™ bone allograft and fixation was achieved using an Integra Surfix(®) locked plate. Mean follow-up was 7.5years (5-9.3years). Clinical and functional outcomes were assessed by determining the IKS and KOOS-PS scores and recording complications related or unrelated to the allograft. The main criterion for assessing OWHTO survival was the time to revision surgery for symptom recurrence. Radiological assessment criteria were the HKA angle, tibial slope, patellar height, and osteoarthritis grade. GESTO criteria were used to evaluate the behaviour of the allograft. RESULTS: Of the 69 knees, 64 (92.8%) were re-evaluated. The survival rate after 9.3years was 95%±2.7% (3 failures managed with arthroplasty). The functional IKS score improved significantly, by 20 points (P<0.001). Mean increases of 7.8° for the HKA angle and 3.5° for tibial slope were recorded. Bone healing without radiological abnormalities was consistently achieved within 6months. There were no complications related to the allograft (infections, allergies; local or systemic toxicity). DISCUSSION: The clinical, radiological, and safety outcomes documented in our study were similar to those reported in earlier work. LEVEL OF EVIDENCE: IV, retrospective case-series study.