What clindamycin dose should be administered by continuous infusion during combination therapy with rifampicin? A prospective population pharmacokinetics study.

BACKGROUND: Despite its important drug-drug interaction, combined clindamycin/rifampicin therapy may achieve effective plasma clindamycin concentrations, provided clindamycin is administered by continuous infusion. However, the precise clindamycin dose remains unknown. OBJECTIVES: This study was undertaken to determine the daily clindamycin dose to be administered by continuous infusion in combination with rifampicin to achieve effective plasma clindamycin concentrations. PATIENTS AND METHODS: Two plasma clindamycin concentrations were determined prospectively for 124 patients with bone-and-joint infections treated with continuously infused clindamycin. Twenty patients received clindamycin monotherapy, 19 clindamycin combined with rifampicin and 85 received clindamycin successively without and with rifampicin. A population pharmacokinetic model was developed using NONMEM 7.5. Monte Carlo simulations were run to determine which regimens obtained clindamycin concentrations of at least 3 mg/L. RESULTS: A linear one-compartment model with first-order elimination accurately described the data. Clindamycin distribution volume was not estimated. Mean clindamycin clearances with rifampicin and without, respectively, were 33.6 and 10.9 L/h, with 12.8% interindividual variability. The lowest daily clindamycin dose achieving plasma concentrations of at least 3 mg/L in >90% of the patients, when combined with rifampicin, was 4200 mg/24 h. CONCLUSIONS: Our results support continuous infusion of 4200 mg of clindamycin/24 h, in combination with rifampicin. This high-dose regimen requires therapeutic drug monitoring-guided dose adaptation.

Systematic alignments yield balanced knees without additional releases in only 11% of knee arthroplasties: a prospective study.

PURPOSE: The literature suggests that "forgotten" knees are the most stable knees postoperatively. The main objective of our study was to determine whether a systematic alignment (mechanical, anatomical or kinematic) makes it possible to stabilise the operated joint in extension and in flexion. METHODS: This monocentric prospective cohort study was conducted between May 1st, 2021 and October 31st, 2021. A total of 132 consecutive patients undergoing primary navigated total knee arthroplasty were included, with a mean age of 72.4 years (7.9; 48.8-91.2 years), a mean body mass index (BMI) of 28.6 kg/m2 (4.6; 17.6-41.6) and 71.2% (94/132) women. Mechanical, anatomical and kinematic knee alignments were simulated using Kick software for each patient. The primary outcome was the targeted rate of balanced knees for each type of alignment, based on a three-point score, aiming for a 3/3 score for each knee. Our secondary outcome was to characterise the specific implantation finally achieved by the surgeon. RESULTS: The targeted balance was reached in 10.6% (14/132), 10.6% (14/132) and 12.9% (17/132) of knees with mechanical, anatomical and kinematic alignment simulations, respectively. None of these simulations provided a superior number of balanced knees (p = 0.87). When simulating a patient-specific implantation, the highest score was reached in 89.1% (115/132) of cases. CONCLUSION: Systematic alignment simulations achieved knee balance in only 11% of cases. Patient-specific implantation, favouring knee balancing over alignment, allowed an 89% perfect score rate without having to perform any collateral release. LEVEL OF EVIDENCE: Case series. Level 4.

Risk Factors Associated With Femorotomy or Fracture During Cementless Stem Removal and Generation of an Individual Predictive Risk Score.

BACKGROUND: Femorotomy is a commonly used technique during cementless stem removal but should be preferred in selective revision cases to prevent intraoperative femoral fracture associated with deteriorated clinical outcome. Our aim was to assess the risk factors for fracture or femorotomy and develop a predictive risk stratification score. METHODS: A monocentric retrospective cohort including 202 patients was analyzed. Thirty six candidate prognostic factors were assessed. RESULTS: The following independent predictors of fracture or femorotomy were identified: presence of a "bracket sign" (Odds Ratio [OR]: 10.857; 95% Confidence interval [CI]: 2.613-45.115; P = .001) defined as a distal spot weld between the surface of the implant and closest endosteum, bone contact in zone 2 (OR: 4.700; 95% CI: 1.827-12.089; P = .001), 6 (OR: 4.966; 95% CI: 1.823-13.530; P = .002), 12 (OR: 9.660; 95% CI: 3.715-25.116; P < .0001), 13 (OR: 2.958; 95% CI: 1.009-8.021; P = .033), and global hypertrophy (OR: 0.170; 95% CI: 0.036-0.806; P = .026). The prognostic score, named Femorotomy INcidence Numeric scoring system, had good performance and discriminability; the area under the curve of the model was 0.924 (95% CI: 0.878-0.969). CONCLUSION: The only independent risk factors were those assessed on X-ray (eg, bracket sign, bone contact in zones 2, 6, 12, and 13), while global hypertrophy was protective. We noticed the importance of differentiating pedestals and "bracket signs"; the latter is an indicator of fixation of the stem. We developed a risk prediction score (Femorotomy INcidence Numeric score) of fracture or femorotomy that can be used as a companion tool to assess the risk for doing an early osteotomy of the femur.

Revision total hip arthroplasty by a ceramic bearing surface after a third- and fourth-generation ceramic head or liner fracture.

PURPOSE: Although rare, fractures of ceramic components are difficult to revise, mainly due to the presence of residual ceramic debris that can cause catastrophic wear of the replacement components. Modern ceramic-on-ceramic bearings are suggested to improve outcomes of revision total hip arthroplasty (THA) for ceramic fractures. However, there are few published reports of mid-term outcomes of revision THA using ceramic-on-ceramic bearings. We evaluated clinical and radiographic outcomes of 10 patients who received ceramic-on-ceramic bearings during revision THA for ceramic fractures. METHODS: All patients but one received fourth-generation Biolox Delta bearings. Clinical evaluation was performed using the Harris hip score at latest follow-up, and all patients received a radiographic evaluation to analyze the fixation of the acetabular cup and of the femoral stem. Osteolytic lesions and the presence of ceramic debris were noted. RESULTS: After a mean follow-up of 8.0 years, there were no complications or implant failures, and all patients reported satisfaction with their implant. The average Harris hip score was 90.6. There was neither osteolysis nor loosening, but despite our extensive synovial debridement, ceramic debris was noted in the radiographs of five patients (50%). CONCLUSION: We report excellent mid-term outcomes, with no implant failures after eight years despite ceramic debris being found in a significant proportion of patients. We conclude that modern ceramic-on-ceramic bearings are an advantageous option for the revision of THA due to the fracture of initial ceramic components.

Managing early complications in total hip arthroplasty: the safety of immediate revision.

PURPOSE: Immediate revision refers to a reoperation that involves resetting, draping, and exchanging the implant, after wound closure in total hip arthroplasty. The purpose of this study is to investigate the impact of immediate revision after total hip arthroplasty on subsequent infection and complication rates. METHODS: A total of 14,076 primary total hip arthroplasties performed between 2010 and 2020 were identified in our institutional database, of which 42 underwent immediate revision. Infection rates were determined 2 years after the index arthroplasty. The cause and type of revision, duration of primary and revision surgeries, National Nosocomial Infections Surveillance score, implant type, changes in implants, complications, and preoperative and intraoperative antibiotic prophylaxis were all determined. RESULTS: No infections were observed within 2 years after the index arthroplasty. Leg length discrepancy (88%, n = 37) and dislocation (7.1%, n = 3) were the main causes of immediate revision. In most cases of discrepancy, the limb was clinically and radiologically longer before the immediate revision. The mean operative time was 48 ± 14 min for the primary procedure and 23.6 ± 9 min for the revision. The time between the first incision and last skin closure ranged from 1 to 3 h. None of the patients were extubated between the two procedures. Two patients had a National Nosocomial Infections Surveillance score of 2, 13 had a score of 1, and 27 had a score of 0. CONCLUSION: Immediate revision is safe for correcting clinical and radiological abnormalities, and may not be associated with increased complication or infection rates. STUDY DESIGN: Retrospective cohort study; level of evidence, 3.

Streptococcal and Staphylococcus aureus prosthetic joint infections: are they really different?

BACKGROUND: Staphylococci and streptococci are the most frequent pathogens isolated from prosthetic joint infections (PJIs). The aim of this study was to analyze the outcome of streptococcal and methicillin-susceptible Staphylococcus aureus (MSSA) PJIs. METHODS: All monomicrobial streptococcal and MSSA PJIs managed in a French Referral Center (2010-2017) were sampled from the prospective PJIs cohort study. The primary outcome of interest was the cumulative reinfection-free survival at a 2-year follow-up. RESULTS: Two hundred and nine patients with 91 streptococcal and 132 staphylococcal infections were analyzed. Patients with streptococcal PJI were older, and infection was more frequently hematogenous. Reinfection-free survival rates at 2-years after all treatment strategies were higher for patients with streptococcal PJI (91% vs 81%; P = .012), but differed according to the strategy. After exchange arthroplasty, no outcome differences were observed (89% vs 93%; P = .878); after debridement, antibiotics and implant retention (DAIR), the reinfection-free survival rate was higher for patients with streptococcal PJI (87% vs 60%; P = .062). For patients managed with prolonged suppressive antibiotic therapy (SAT) alone, those with streptococcal PJIs had a 100% infection-free survival (100% vs 31%; P < .0001). CONCLUSIONS: Reinfection-free survival after DAIR and SAT was better for patients with streptococcal than those with MSSA PJIs. No difference was observed after prosthesis exchange.

Measurement of Serum Anti-staphylococcal Antibodies Increases Positive Predictive Value of Preoperative Aspiration for Hip Prosthetic Joint Infection.

BACKGROUND: Preoperative synovial fluid culture is pivotal in the early diagnosis of prosthetic joint infection (PJI) but may yield false-positive and false-negative results. We evaluated the predictive value of synovial fluid culture results combined with the measurement of serum anti-staphylococcal antibodies (SASA). QUESTIONS/PURPOSES: (1) For hip and knee PJI, does combining positive SASA results with preoperative synovial culture results improve the positive predictive value (PPV) of preoperative synovial fluid culture alone? (2) Does combining preoperative synovial fluid culture results with a positive cell count and differential result increase the PPV of preoperative synovial fluid culture alone? (3) What proportion of isolated organisms exhibit concordance in antibiotic susceptibility: preoperative aspiration versus intraoperative isolates? METHODS: A prospective study was conducted at two French reference centers that manage bone and joint infections and included 481 adult patients who had a revision or resection arthroplasty between June 25, 2012 and June 23, 2014. Exclusion criteria including no serum sample available for immunoassay, the lack of microbiological documentation, and the absence of preoperative aspiration reduced the patient number to 353. Seven patients with an undetermined SASA result were excluded from the analysis. We also excluded patients with PJI involving more than one Staphylococcus species (polystaphylococcal infection) and those in whom more than one Staphylococcus species was recovered from the preoperative synovial fluid culture (polystaphylococcal synovial fluid culture). In total, 340 patients were included in the analysis (no infection, 67% [226 of 340]; staphylococcal infection, 21% [71 of 340]; other infection, 13% [43 of 340]). The preoperative synovial fluid analysis included a cell count and differential and bacterial culture. SASAs were measured using a multiplex immunoassay. The diagnosis of PJI was determined using the Infectious Diseases Society of America (IDSA) criteria [] and intraoperative tissue culture at the time of revision surgery was used as the gold standard (at least one positive intraoperative sample for a "virulent" organism (such as S. aureus) or two positive samples for a "non-virulent" (for example S. epidermidis). RESULTS: SASA increased the PPV compared with synovial fluid culture alone (92% [95% CI 82 to 97] versus 79% [95% CI 68 to 87]; p = 0.04); when stratified by site, an increase in PPV was seen in hip infections (100% [95% CI 89 to 100] versus 77% [95% CI 63 to 88]; p = 0.01) but not in knee infections (84% [95% CI 66 to 95] versus 80% [95% CI 64 to 91]; p = 0.75). A positive cell count and differential result increased the PPV of staphylococcal synovial fluid cultures compared with synovial fluid culture alone (86% [95% CI 70 to 95] versus 79% [95% CI 68 to 87]; p = 0.36); when stratified by site, no difference in hip and knee infections was observed (86% [95% CI 67 to 96] versus 77% [95% CI 63 to 88]; p = 0.42) and 86% [95% CI 70 to 95] versus 80% [95% CI 64 to 91]; p = 0.74). CONCLUSION: SASA measurement improves the predictive value of synovial fluid cultures of the hip for all staphylococcal organisms, including coagulase-negative staphylococci, but the PPV of SASA plus synovial fluid culture it is not superior to the PPV of synovial fluid cell count/differential plus synovial culture for the knee. LEVEL OF EVIDENCE: Level III, diagnostic study.

Over-voluming predicted by pre-operative planning in 24% of total knee arthroplasty.

PURPOSE: Numerous studies demonstrated that prosthetic overhang and over-sizing cause pain and stiffness following total knee arthroplasty (TKA), but none considered volume changes within the joint capsule. This study was designed to investigate differences in volumes of resected bone compared to implanted components in TKA, and to determine the incidence and factors related to 'over-voluming'. METHODS: Three-dimensional reconstructions were created from 100 magnetic resonance imaging scans taken to design patient-specific instruments for TKA. The preoperative simulations were used to calculate the volume ratio (VR) by dividing volume of planned components by that of planned bone resections. Uni- and multi-variable linear regressions were performed to determine associations between 'over-voluming' (VR > 1.0) and gender, implant size and version (standard versus narrow), osteophytes, resection levels, external rotation of the femoral component, hip-knee-ankle (HKA) angle, mechanical lateral distal femoral angle (mLDFA), and mechanical medial proximal tibial angle (mMPTA). RESULTS: The overall implant/bone volume ratio was 0.91 ± 0.11 (range 0.63-1.16) with 'over-voluming' observed in 24 knees. Multi-variable regression confirmed over-voluming to be associated with lower mLDFA (OR 0.66; CI 0.45-0.93; p = 0.026) and extensive osteophytes (OR 0.14; CI 0.03-0.61; p = 0.014), but not HKA angle (OR 0.98; CI 0.76-1.26; p = n.s.). CONCLUSIONS: Over-voluming was observed in 24% of knees, in which the implant volume exceeded the resected volume by up to 16%. Over-voluming was associated with intra-articular femoral valgus (low mLDFA), but not directly associated with tibial deformity (mMPTA) or HKA angle. Over-voluming could be associated with prosthetic overhang or excessive tensions within the joint capsule, and, therefore, contribute to unexplained pain and stiffness following TKA. LEVEL OF EVIDENCE: IV, Retrospective cohort study.

Cutibacterium (Formerly Propionibacterium) avidum: A Rare but Avid Agent of Prosthetic Hip Infection.

BACKGROUND: Cutibacterium spp. (formerly Propionibacterium) are slow-growing cutaneous anaerobic commensals, rarely reported in prosthetic joint infections (PJIs). We describe epidemiological, clinical, biological, and radiological characteristics of 15 Cutibacterium avidum PJIs, their treatments, and outcomes. METHODS: This study is an observational, monocenter study (January 2004 to April 2017), with comparison of C avidum vs Cutibacterium acnes (n = 40) PJI characteristics. RESULTS: Among 1179 PJIs treated during the study period, 15 (1%) PJIs were due to C avidum (14 classified as late chronic and 1 as early postoperative). They involved only obese patients with hip arthroplasties (median age 65 years, body mass index 35 kg/m2). Twelve patients' PJIs developed after primary hip arthroplasty. Thirteen patients' last clean operation had used an anterior approach. Fourteen preoperative joint aspirate cultures yielded C avidum. The 14 chronic PJIs were treated with 1-stage exchange arthroplasty, the acute case with excision synovectomy. Antibiotic therapy was administered for 12 [6-13] weeks, intravenously for 4 [2-6] weeks. The most used first-line agents were intravenous clindamycin (n = 8) or cefazolin (n = 6). After median follow-up of 27 [3-136] months, 1 relapse occurred. Compared to C acnes PJI patients, those with C avidum PJIs were significantly younger, had higher body mass indices, had only hip involvement, and had more frequent anterior surgical approach. C acnes PJIs were more frequent after revision arthroplasty. CONCLUSION: C avidum is a rare PJI agent occurring in a particular subpopulation. Joint aspiration is the key diagnostic tool. Our results suggest that PJI risk factors include obesity, primary hip arthroplasty, and anterior surgical approach. Efforts to prevent these infections in high-risk patients should be developed.

Large Cohort Study of Central Venous Catheter Thrombosis during Intravenous Antibiotic Therapy.

The frequency and risk factors for central venous catheter-related thrombosis (CRT) during prolonged intravenous (i.v.) antibiotic therapy have rarely been reported. The primary objective of this study was to evaluate the frequency, incidence, and risk factors for CRT among patients being treated with prolonged i.v. antibiotic therapy. The secondary objective was to describe the clinical manifestations, diagnostic evaluation, and clinical management. This cohort study was conducted between August 2004 and May 2010 in a French referral center for osteoarticular infections. All patients treated for bone and joint infections with i.v. antimicrobial therapy through a central venous catheter (CVC) for ≥2 weeks were included. Risk factors were identified using nonparametric tests and logistic regression. A case-control study investigated the role of vancomycin and catheter malposition. A total of 892 patients matched the inclusion criteria. CRT developed in 16 infections occurring in 16 patients (incidence, 0.39/1,000 catheter days). The median time to a CRT was 29 days (range, 12 to 48 days). Local clinical signs, fever, and secondary complications of CRT were present in 15, 8, and 4 patients, respectively. The median C-reactive protein level was 95 mg/liter. The treatment combined catheter removal and a median of 3 months (1.5 to 6 months) of anticoagulation therapy. The outcome was good in all patients, with no recurrence of CRT. Three risk factors were identified by multivariate analysis: male sex (odds ratio [OR], 5.4; 95% confidence interval [CI], 1.1 to 26.6), catheter malposition (OR, 5.3; 95% CI, 1.6 to 17.9), and use of vancomycin (OR, 22.9; 95% CI, 2.8 to 188). Catheter-related thrombosis is a rare but severe complication in patients treated with prolonged antimicrobial therapy. Vancomycin use was the most important risk factor identified.

Multiplex Antibody Detection for Noninvasive Genus-Level Diagnosis of Prosthetic Joint Infection.

We developed and evaluated a multiplex antibody detection-based immunoassay for the diagnosis of prosthetic joint infections (PJIs). Sixteen protein antigens from three Staphylococcusspecies (Staphylococcus aureus,Staphylococcus epidermidis, and Staphylococcus lugdunensis) (8 antigens),Streptococcus agalactiae(4 antigens), and Propionibacterium acnes(4 antigens) were selected by comparative immune proteomics using serum samples from PJI cases versus controls. A bead-based multiplex immunoassay that measured serum IgG against purified, recombinant forms of each of the 16 antigens was developed. We conducted a prospective study to evaluate the performance of the assay. A PJI was defined by the presence of a sinus tract and/or positive intraoperative sample cultures (at least one sample yielding a virulent organism or at least two samples yielding the same organism). A total of 455 consecutive patients undergoing revision or resection arthroplasty (hip, 66.3%; knee, 29.7%; shoulder, 4%) at two French reference centers for the management of PJI were included: 176 patients (38.7%) were infected and 279 (61.3%) were not. About 60% of the infections involved at least one of the species targeted by the assay. The sensitivity/specificity values were 72.3%/80.7% for targeted staphylococci, 75%/92.6% forS. agalactiae, and 38.5%/84.8% forP. acnes The assay was more sensitive for infections occurring >3 months after arthroplasty and for patients with an elevated C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR). However, it detected 64.3% and 58.3% of targeted staphylococcal infections associated with normal CRP and ESR values, respectively. This new multiplex immunoassay approach is a novel noninvasive tool to evaluate patients suspected of having PJIs and provides information complementary to that from inflammatory marker values.

Concomitant Multiple Joint Arthroplasty Infections: Report on 16 Cases.

BACKGROUND: Concomitant infections of several prostheses are very rare, serious events that pose particular medical and surgical therapeutic challenges. This study was undertaken to describe epidemiologic, clinical, and microbiological characteristics of concomitant multiple joint arthroplasty infections, their treatments, and outcomes. METHODS: Retrospective (January 2000 and January 2014), single-center, cohort study in a referral center for bone and joint infections. All patients with at least 2 concomitant, microbiologically documented, prosthetic joint infections, that is, during the same septic episode, were included. RESULTS: Sixteen patients were included. Median (range) age was 78 years (46-93 years), gender ratio was 1, and median (range) body mass index was 27 (21-42). Multiple joint arthroplasties (bilateral hip in 8 patients; bilateral knee in 3 patients; hip and knee in 1 patient; and 2 knees and 1 hip in 1 patient) were contaminated hematogenously in all patients, 2 after early postoperative infections. Eight Staphylococcus aureus, 1 Staphylococcus epidermidis, 6 Streptococcus, and 1 Escherichia coli strains were isolated. A curative strategy was applied to 11 patients: 3 underwent bilateral synovectomies, 6 had successive 1-stage exchange arthroplasties, and 2 were treated with other strategies. After 37 months (range, 24-132 months) of follow-up, reinfection occurred in 1 patient. The 5 other patients received prolonged suppressive antibiotic therapy. CONCLUSION: These complex infections occur during staphylococcal or streptococcal bacteremia. Treatment strategies should be discussed by a multidisciplinary team on a case-by-case basis.

Knee arthroplasty and lawsuits: the experience in France.

PURPOSE: Data regarding knee arthroplasty and lawsuit are scarce. With the expected increase in knee arthroplasty over the next 25 years, the number of claims might follow the same trend. Therefore, the most frequent causes of litigation after knee arthroplasty in France, and what is considered as malpractice by the expert, were determined. METHODS: Over 8-year period, data gathered from a French private insurance company specializing in malpractice for private practitioners were analyzed. Demographics, type of knee arthroplasty, reason for claim, details of the legal procedure and the expert's decision were reviewed. RESULTS: One hundred and five claims were processed by four jurisdictions. Most of the cases concerned primary total knee arthroplasty. Surgeons and anesthesiologists were charged in 84 and 16 % of claims, respectively. The most frequent causes of litigation were infection, neurological deficit and unsatisfactory result, whereas the most common reasons for the surgeon's liability, as stated by the expert, were delay in diagnosis or treatment of a complication, infection and technical error. CONCLUSION: Our findings show that frequent complications are not those which raise most of the claims. Patients sue the surgeon when the outcome of the surgery is different from what they were expecting. An unsatisfactory result, according to the patient's point of view, is the second most frequent cause of claim. LEVEL OF EVIDENCE: IV, Economic and Decision Analysis. See the Guidelines for Authors for a complete description of levels of evidence.

Doctor, what does my knee arthroplasty weigh?

The aim of this study was to compare the weight of the total knee arthroplasty (TKA) implants and the weight of the natural knee. A prospective study was conducted with two different brands of cemented primary TKA. During the procedure, we collected the removed bone, soft tissues and the post-implantation cement and weighed them all separately at the end. In both groups, the implants plus cement were significantly heavier than the removed bone and soft tissues. The average weight gained was 266.7 ± 35.1 g for group 1 and 279.1 ± 48.7 g for group 2. This significant local weight gained after TKA is a new parameter that should be taken into account for further studies and when creating new implants.

In silico analysis of the patient-specific acetabular cup anteversion safe zone.

INTRODUCTION: Various computer-assisted surgical systems claim to improve the accuracy of cup placement in total hip arthroplasties after assessing spinopelvic mobility to prevent prosthetic impingement. However, no study has yet analyzed the extent of the patient-specific cup anteversion safe zones. HYPOTHESIS: We hypothesized that most patients have a safe zone >10 °, except those with abnormal spinopelvic mobility, who have a much narrower safe zone. MATERIALS AND METHODS: We simulated the risks of prosthetic impingement using the planned cup anteversion. The consecutive cohort included 341 patients who underwent total hip arthroplasty. Our primary endpoint was the patient-specific impingement-free zone for cup anteversion, which was then divided into four subgroups: 0 °, 1 ° to 5 °, 6 ° to 10 °, and >10 °. This data was then secondarily analyzed for abnormal spinopelvic mobility (the difference in the spinopelvic tilt [ΔSPT] from a standing to a flexed seated position >20 °). RESULTS: The mean anteversion safe zone was 22.8 ° with 82.4% (281/341) of patients with a zone strictly >10 °. The mean safe zone was 8.9 ° (+/- 9 °) in patients with an ΔSPT ≥20 ° (18.2%), with 37.1% of these patients having a zone of 0 °, 16.13% a zone between 1 ° and 5 °, 8.06% a zone between 6 ° and 10 ° and 38.71% a zone >10 °. The mean safe zone was 25.9 ° (+/- 9 °) in patients with an ΔSPT <20 ° (81.8%), and the proportion of cases in each zone was 2.51%, 1.08%, 4.3%, and 92.11%, respectively (p < 0.001). CONCLUSION: The safe zone for anteversion appears to be fairly wide in most patients. However, identifying patients at risk of abnormal spinopelvic mobility seems necessary to identify the two-thirds of patients with a narrow safe zone. LEVEL OF EVIDENCE: IV; retrospective study.

Comparison of survival between cemented vs cementless unicompartimental knee arthroplasty: a case control study with propensity score matching.

INTRODUCTION: The first results of cementless prosthesis were rather disappointing. However recent progress in methods of cementless fixation of prosthesis should lead to better results in terms of survival of these prostheses. The main objective is to compare the survival rate at last follow-up of UKA with cemented tibial or cementless. HYPOTHESIS: We hypothesize that UKAs with uncemented tibial implants have better survival compared to UKAs with cemented tibial implants. MATERIAL AND METHODS: This single center case-control study included 94 medial UKA with a cemented tibial component that were paired by propensity score matching to 94 medial UKA with a uncemented tibial component. The main evaluation criterion was the comparison of the survivorship of the UKA between a cemented tibial implant and those with a cementless tibial implant in terms of all-cause revision surgery at last follow-up. The secondary endpoints were the analysis of the causes of failure. RESULTS: The mean final follow-up was 6.1years (2.3). The overall survival rate in our serie of medial UKA was 92.4% [88.7%-96.3%] at five years. The overall survival rate in cemented group was and 91.5% [86.0%-97.3%] at five years and at 93.2% [88.1%-98.7%] at five years, in the uncemented group. No differences significant were observed in the two groups (p.value = 0.6). Only the tibial preoperative deformity was a risk factor of failure (HR: 1.11 [1.02, 1.20], value = 0.02). DISCUSSION: The use of a cemented or a cementless tibial component in a medial UKA did not influence the survival rate. LEVEL OF EVIDENCE: III; case control study.

Collared versus collarless hydroxyapatite-coated stems for primary cementless total hip arthroplasty; a systematic review of comparative studies. Is there any difference in survival, functional, and radiographic outcomes?

INTRODUCTION: This systematic review aims to critically assess the literature comparative studies investigating collared and collarless Corail stem in primary total hip arthroplasty (THA) to find differences in revision rates, radiographic and clinical outcomes, and postoperative complications between these two types of the same stem. METHODS: Eligible studies were found by searching PubMed, Science Direct/Scopus, and the Cochrane Database of Systematic Reviews from conception till May 2023. The PRISMA guidelines were followed. The investigation encompassed randomized controlled trials, case series, comparative, cohort, and observational studies that assessed at least one comparative outcome or complication between collared and collarless Corail stems. RESULTS: Twelve comparative studies with 90,626 patients undergoing primary THA were included. There were 40,441 collared and 58,543 collarless stems. The follow-up ranged from 12 to 360 months. Our study demonstrated no significant difference in stem revision relative risk (RR = 0.68; 95% confidence interval (CI), 0.23, 2.02; p = 0.49), number of radiolucent lines (RR = 0.3; 95% CI, 0.06, 2.28; p = 0.29) and overall complication risk (RR = 0.62; 95% CI, 0.22, 1.76; p = 0.37) between collared and collarless stems. The collared stems demonstrated significantly lesser subsidence (mean difference: 1.01 mm; 95% CI, -1.77, -0.25; p = 0.009) and risk of periprosthetic fractures (RR = 0.52; 95% CI, 0.29, 0.92; p = 0.03). CONCLUSION: The comparative studies between collared and collarless stem groups showed similar survival and overall complication rates and functional outcomes. The similar revision rates between groups make the impact of higher subsidence for collarless stems uncertain. The lower risk of periprosthetic fractures in the collared stems group must be clarified further but could be related to increased rotational stability.

Campylobacter infection after prosthetic joint surgery.

Few cases of Campylobacter prosthetic joint infection (PJI) have been reported so far. We describe the demographic characteristics, underlying conditions, clinical features, treatment, and outcome of 8 patients with Campylobacter PJI in our hospital. All strains were confirmed at the French National Reference Center for Campylobacter and Helicobacter. Seven patients were infected with C. fetus and 1 with C. jejuni. Most patients were elderly and immunocompromised. Four had bacteremia, one of these with a pacemaker endocarditis. All the patients received at least 3 months of antibiotic treatment and 6 were treated surgically. The outcome was favorable at 2 years of follow-up in all except for 1 patient. Campylobacter PJI cases are rare but likely to become more frequent. C. fetus bacteremia should motivate physicians to look for a secondary localization such as a Campylobacter PJI.

One-stage revision for infected shoulder arthroplasty: prospective, observational study of 37 patients.

Background: Periprosthetic joint infection is a severe complication of joint replacement surgery. Thus two-stage exchange remains the gold standard, one-stage exchange is now widely recommended. We hypothesized that, for patients with chronic periprosthetic shoulder infection (PSI), treatment with a one-stage exchange would be an effective approach to eradicate infection, relieve pain, and restore function to the involved shoulder. Materials and methods: This monocenter cohort study in a Bone and Joint Infection Referral Center (11/2003-05/2020) included all patients with confirmed PSI treated by one-stage revision. Data were extracted from the prospective database, including demographics, infection characteristics, and functional evaluations (range of motion and Constant Score at admission and last follow-up). The primary outcome was the 2-year reinfection-free rate. Results: We included 37 patients. The refection-free rate was 5%. The most commonly isolated pathogen was Cutibacterium acnes (68%), isolated alone (15 patients, 41%) or as polymicrobial infections (10 patients, 27%). The Constant Score increased significantly from 24 to 53 (P = .001). Range of motion (forward elevation, abduction) was also significantly improved after surgery. Mean active forward elevation increased significantly by 45° from 60° to 105° postoperatively (P < .001), mean abduction increased by 42° from 55° to 97° (P < .001). Discussion: Results from our prospective cohort-extracted series suggest that one-stage revision is a reliable treatment with a low infection recurrence rate. Improved functional outcomes can be achieved with one-stage exchange. Our patients' overall functional results were similar to those previously reported for one-stage revision and better than those reported after two-stage exchange. Patients with multiple previous surgeries seem to have worse functional outcomes than the subgroup without surgery before the index arthroplasty. Conclusions: Our results and literature search findings suggest that one-stage revisions effectively eradicate PSIs, with good functional outcomes.

Are self-reported anthropometric data reliable enough to meet antibiotic prophylaxis guidelines in orthopedic surgery?

BACKGROUND: Surgical site infection is a serious complication in orthopedic surgery. The use of antibiotic prophylaxis (AP) combined with other prevention strategies has been shown to reduce this risk to 1% for hip arthroplasty and 2% for knee arthroplasty. The French Society of Anesthesia and Intensive Care Medicine (SFAR) recommends doubling the dose when the patient's weight is greater than or equal to 100 kg, and the body mass index (BMI) is greater than or equal to 35 kg/m2. Similarly, patients with a BMIgreater than40 kg/m2 orlesser than18 kg/m2 are ineligible for surgery in our hospital. Self-reported anthropometric measurements are commonly used in clinical practice to calculate BMI, but their validity has not been assessed in the orthopedic literature. Therefore, we conducted a study comparing self-reported with systematically measured values and observed the impact these differences may have on perioperative AP regimens and contra-indications to surgery. HYPOTHESIS: The hypothesis of our study was that self-reported anthropometric values differed from those measured during preoperative orthopedic consultations. MATERIALS AND METHODS: This single-center retrospective study with prospective data collection was conducted between October and November 2018. The patient-reported anthropometric data were first collected and then directly measured by an orthopedic nurse. Weight was measured with a precision of 500 g and height was measured with a precision of 1 cm. RESULTS: A total of 370 patients (259 women and 111 men) with a median age of 67 years (17-90) were enrolled. The data analysis found significant differences between the self-reported and measured height [166 cm (147-191) vs. 164 cm (141-191) (p<0.0001)], weight [72.9 kg (38-149) vs. 73.1 kg (36-140) (p<0.0005)] and BMI [26.3 (16.2-46.4) vs. 27 (16-48.2) (p<0.0001)]. Of these patients, 119 (32%) reported an accurate height, 137 (37%) an accurate weight, and 54 (15%) an accurate BMI. None of the patients had two accurate measurements. The maximum underestimation was 18 kg for weight, 9 cm for height, and 6.15 kg/m2 for BMI. The maximum overestimation was 28 kg for weight, 10 cm for height, and 7.2 kg/m2 for BMI. The verification of the anthropometric measurements identified another 17 patients who had contra-indications to surgery (12 with a BMI>40 kg/m2 and 5 with a BMI<18 kg/m2) and who would not have been detected based on the self-reported values. CONCLUSIONS: Although patients underestimated their weight and overestimated their height in our study, these had no impact on the perioperative AP regimens. However, this misreporting failed to detect potential contraindications to surgery. LEVEL OF EVIDENCE: IV; retrospective study with prospective data collection and no control group.