Impact of a Novel Antiseptic Lavage Solution on Acute Periprosthetic Joint Infection in Hip and Knee Arthroplasty.

Background: Periprosthetic joint infection (PJI) represents a challenge following hip or knee arthroplasty, demanding immediate intervention to prevent implant failure and systemic issues. Bacterial biofilm development on orthopedic devices worsens PJI severity, resulting in recurrent hospitalizations and significant economic burdens. The objective of this retrospective cohort study is to evaluate the efficacy of this novel antiseptic solution, never previously evaluated in vivo, in managing early post-operative or acute hematogenous PJI following primary hip and knee joint replacements. Methods: The inclusion criteria consist of patients with total hip arthroplasty (THA) or knee arthroplasty diagnosed with acute PJI through preoperative and intraoperative investigations, in accordance with the MSIS ICM 2018 criteria. The minimum required follow-up was 12 months from the cessation of antibiotic therapy. This novel antiseptic lavage solution is composed of ethanol, acetic acid, sodium acetate, benzalkonium chloride and water. Data included demographic characteristics, diagnostic criteria, surgical techniques, post-operative treatment and follow-up outcomes. Results: A total of 39 patients treated with Debridement, Antibiotics Pearls and Retention of the Implant (DAPRI) procedures using this solution between May 2021 and April 2023 were analyzed. At a mean follow-up of 24.6 ± 6.4 months, infection recurrence-free survival rates were 87.2%, with no local allergic reactions or relevant systemic adverse effects detected. Persistent PJI necessitated two-stage revision surgery. Conclusions: This novel antiseptic lavage solution shows promise as an adjunctive tool in the treatment of PJI, demonstrating support in infection control while maintaining a favorable safety profile.

The Role of Artificial Intelligence in Anterior Cruciate Ligament Injuries: Current Concepts and Future Perspectives.

The remarkable progress in data aggregation and deep learning algorithms has positioned artificial intelligence (AI) and machine learning (ML) to revolutionize the field of medicine. AI is becoming more and more prevalent in the healthcare sector, and its impact on orthopedic surgery is already evident in several fields. This review aims to examine the literature that explores the comprehensive clinical relevance of AI-based tools utilized before, during, and after anterior cruciate ligament (ACL) reconstruction. The review focuses on current clinical applications and future prospects in preoperative management, encompassing risk prediction and diagnostics; intraoperative tools, specifically navigation, identifying complex anatomic landmarks during surgery; and postoperative applications in terms of postoperative care and rehabilitation. Additionally, AI tools in educational and training settings are presented. Orthopedic surgeons are showing a growing interest in AI, as evidenced by the applications discussed in this review, particularly those related to ACL injury. The exponential increase in studies on AI tools applicable to the management of ACL tears promises a significant future impact in its clinical application, with growing attention from orthopedic surgeons.

Lateral UKA can be a safe solution in a young patients' population: a 10-year follow-up report.

BACKGROUND: This study aimed to assess the long-term survivorship and functional outcomes of fixed-bearing lateral unicompartmental knee arthroplasty (UKA) in a young patients' population with osteoarthritis limited to the lateral compartment. METHODS: The study included a cohort of consecutive patients who underwent lateral UKA between January 2008 and December 2014 at a single high-volume surgical center. The surgical procedures were performed by experienced surgeons using a lateral parapatellar approach and fixed-bearing implants. Patient follow-up included a retrospective re-evaluation, clinical assessments, patient-reported outcome measures (PROMs), and X-ray analysis. RESULTS: A total of 40 lateral UKAs were analyzed, with 19 performed on the left and 21 on the right knee. The mean age of the patients at the time of surgery was 57.6 years, and the mean BMI was 24.8. At the final follow-up, 80% of patients achieved excellent outcomes (OKS > 41), and 20% had good outcomes (OKS: 34-41). No patients exhibited fair or poor outcomes. The mean FJS at the final follow-up was 82.8. The mean WOMAC was 10.5. Kaplan-Meier survival analysis revealed a survivorship rate of 93.1% at 10 years, considering revision for any reason as endpoint. CONCLUSIONS: Lateral UKA proved to be an effective treatment option for osteoarthritis affecting the lateral compartment of the knee. The study demonstrated a high survivorship rate and favorable functional outcomes at a mean follow-up of 132.7 months. These findings highlight the potential benefits of fixed-bearing lateral UKA in selected patients with lateral compartment knee pathology.

The use of a modern robotic system for the treatment of severe knee deformities.

BACKGROUND: Robotic-assisted total knee arthroplasty (TKA) have shown promising results in recent years with improved clinical outcomes using standard primary implants. OBJECTIVE: The purpose of this study was to assess the experience of a single center in correcting severe coronal deformities with the use of a robotic-assisted TKA system and an increased constrained implant. METHODS: Between July 2020 and December 2022, 30 knees in 28 patients with a major deformity and an associated ligament laxity requiring an increased constrained implant treated using an imageless robotic-assisted TKA were prospectively enrolled. Patients included in the study showed a minimum 15 degrees varus or 10 degrees valgus deviation. RESULTS: 20 cases were varus knees and 10 cases were valgus knees. Postoperative neutral alignment was defined as 0∘± 2.5∘. A CCK implant was used in 20 cases while a Constrained Posterior Stabilized implant was used in 10 cases. A neutral alignment was achieved in all patients. At a minimum 6 months follow up (f-u 6-30 months) clinical outcomes including ROM, KSS, HSS, OKS and WOMAC showed significant improvement and no major complications were registered. CONCLUSIONS: The robotic system showed the achievement of a mechanical alignment with reliable radiographic outcomes and clinical results in the treatment of major deformities of the lower limb with the use of higher constrained implants at short term follow up. Further follow up and studies are necessary to confirm and verify these promising outcomes.

PCL preservation or sacrifice does not influence clinical outcomes and survivorship at mid-term follow-up of a J-curve CR total knee replacement with a medial congruent liner and a functional coronal alignment.

BACKGROUND: In recent years, increasing interest has arisen for medial pivoting TKA implants, designed to mimic the physiological knee kinematics, maximizing the contact area on the medial compartment of the knee, increasing anterior-posterior stability, and contributing to a ball-in-socket effect that allows the posterior cruciate sacrifice without a post-CAM mechanism. The medial congruent liner works with a J-curve cruciate-retaining (CR) femur without a real ball-in-socket design. The aim of this study was to evaluate the clinical outcomes and survival of these implants, with or without PCL sparing, at a medium follow-up. METHODS: Between October 2016 and October 2018, 165 TKRs were performed in 161 patients (69.2% females and 30.8% males) and prospectively followed. Mean follow-up was 72 ± 12 months. All surgeries were performed using an extramedullary device and the same prosthetic implant. Patients were matched in two groups: in 80 patients, the PCL was preserved; in 85 patients, the PCL was sacrificed with a reduction of the tibial slope. RESULTS: The OKS and KSS improved in both groups. The difference between the two groups at the final follow-up was not statistically significant. Good-to-excellent clinical results according to the KSS were achieved in 93% of the knees in the PCP group and in 95% in the PCS group. At final follow-up, the Forgotten Joint Score (FJS) was 73.6 in the PCP group and 74.1 in the PCS group with no statistical difference between the two groups (P > 0.05). CONCLUSIONS: TKA with a medially congruent insert, showed promising results at mid-term follow-up, PCL preservation or sacrifice did not affect the clinical outcomes and survival. Further follow-up will be needed to evaluate these results at long term.

Increased accuracy in component positioning using an image-less robotic arm system in primary total knee arthroplasty: a retrospective study.

BACKGROUND: Robotic-assisted total knee arthroplasty (RTKA) and navigated total knee arthroplasty (NTKA) have shown improved knee alignment and reduced radiographic outliers. Recent studies have proven that conventional mechanical alignment may not be the optimal goal for every patient. The aim of this study was to compare the accuracy of the planned implant positioning of a novel image-less robotic technique with an established navigated technique (NTKA). METHOD: The study is a retrospective analysis of prospectively collected data that compared the implant positioning and lower-limb alignment of 86 image-less RTKA with 86 image-less NTKA. Radiographic analysis was performed to evaluate the lower-limb overall alignment, femoral and tibial components positioning in the coronal and sagittal planes. Outliers were evaluated with a cutoff of ± 3°. RESULTS: No difference was noted between the two groups for radiographic outliers within ± 3° from neutral (p = 0.098). The mean hip-knee-ankle angle deviation from target was 1.3° in the RTKA group compared to 1.9° in the NTKA (p < 0.001). Femoral sagittal deviation (femoral component flexion) was smaller in the RTKA group (0.9° vs 1.9°; p < 0.001). Similarly, tibial coronal deviation (0.8° vs 1.5°; p < 0.001) and tibial sagittal deviation (tibial slope) were smaller in the RTKA group compared to the NTKA group (0.9° vs 1.7°; p < 0.001). CONCLUSIONS: The RTKA group reported a substantial and significant reduced error from the planned target angles for both tibial and femoral components. No difference in terms of radiographic outliers was noted between navigation and robotic assistance.

What Is the Most Reliable Concordance Rate of Preoperative Synovial Fluid Aspiration and Intraoperative Biopsy to Detect Periprosthetic Joint Infection in Knee, Hip and Shoulder Arthroplasty?

The accuracy of preoperative synovial fluid microbe detection in periprosthetic joint infection (PJI) is widely reported. However, the reliability of this diagnostic modality amongst the different joints is not yet described. We aimed to compare the concordance rate between preoperative synovial fluid and intraoperative tissue cultures in shoulder, knee and hip PJIs. A total of 150 patients who met the 2018 International Consensus Meeting criteria for shoulder, hip and knee PJI were retrospectively reviewed. This cohort was divided into three groups based on the involved joint (should, hip or knee), with 50 patients in each group. Cultures were collected and held for culture for 14 days. The overall concordance rate was 56.7%. Concordance rates between preoperative and intraoperative cultures were 60%, 56% and 54% for the knee, shoulder and hip joints, respectively. The analysis of high- or low-virulence and difficult- or not-difficult-to-treat germs did not reveal any significant differences between preoperative and intraoperative cultures in any of the groups. However, even considering the higher concordance in knee PJI, the overall discordance between preoperative and intraoperative cultures should prompt surgeons not to rely solely on preoperative synovial fluid culture data in determining appropriate treatment and antibiotics.

Uncemented hemiarthroplasty may have a role in the treatment of unstable intertrochanteric fractures in elderly patient. A survival complications and functional outcomes analysis.

BACKGROUND: Fractures of the proximal femur account for 30% of all fractures requiring surgical treatment. The optimal treatment for per- and intertrochanteric fractures, particularly associated with trochanter instability, is still open to debate. For these reasons, some authors have recently supported the use of bipolar arthroplasty or hemiarthroplasty as a treatment capable of reducing the risk of complications and obtaining a better functional result. The purpose of this study was to evaluate the functional and clinical outcomes at minimum six months of follow up of bipolar hemiarthroplasty as the primary treatment for intertrochanteric fracture in older patients. A secondary objective was to study the risk of early and intraoperative complications. METHODS: From November 2020 to April 2022, 102 patients with lateral proximal femur fracture underwent surgical operation with implant of a long-stemmed bipolar hemiarthroplasty. 86 patients were enrolled. The average age at the time of fracture was 87.4 ± 4.6 (range 77-98) years. Of the patients, 76.7% were female. For all patients intra- and perioperative data were extracted. All available patients were evaluated at a minimum 6-months follow-up to investigate: Charlson Comorbidity Index, autonomy (Barthel Index), use of walking aids (Koval Grade), memory quality or dementia (Mental Score), subsequent hospitalizations for surgical operations relating to the operated hip. RESULTS: The average time from trauma to surgery was 1 ± 0.7 days. The surgical time was 78.9 ± 21.9 minutes. At least one cerclage was used in 73.3% of patients. 87.5% of patients were verticalized on the first day. The average hospitalization time was 5.5 ± 2.9 days. During follow-up 20 deaths occurred, with a distance to surgery of 6.6 ± 7.2 (range 0.3-22.7) months. Six months after surgery, out of 86 patients, 12 deaths occurred, corresponding to 13.95%. 12 months after surgery, out of 57 patients, 15 deaths occurred, corresponding to 26.31%. CONCLUSIONS: Long stemmed bipolar hemiarthroplasty following intertrochanteric fracture can be considered a safe procedure, especially in patients over 80 with associated comorbidities and short life expectancy.

Do age, gender, and region affect tibial slope? A multi-center study.

INTRODUCTION: Tibial slope is a parameter that is important to recognize in knee kinematics and knee surgery. A very wide range of values governing posterior tibial slope exist in the literature. This study is based on the hypothesis that age, gender and region may have an effect on the tibial slope. MATERIALS AND METHODS: A total of 1800 lateral knee radiographies from five different countries [Turkey, Germany, Italy, Spain, and the United Kingdom (UK)] were utilized to measure the native posterior tibial slope. Participants were categorized in deciles with each decade of age after 40 years determined as a separate age group. Accordingly, four different age categories were formed in total, namely, the 40- to 49-, 50- to 59-, 60-69, and 70- to 79-year-old groups. Patients with severe knee osteoarthritis, those with a history of arthroscopic and open surgery around the knee, and those with severe morbid obesity and those outside the specified age group were excluded from the study. The angle between the line tangential to the medial tibial plateau and the proximal anatomical axis of the tibia was measured. RESULTS: The tibial slope values of both males and females in the Turkish population were found to be higher than those in other populations. It was observed that tibial slope values increased with age in females in all populations, except for those in the Spanish and UK populations. In the male population, it was found that tibial slope values increased with age in all populations except in the Spanish population. CONCLUSIONS: Region, age, and gender affect tibial slope in different populations in various ways. Our study shows that the region an individual lives in and living conditions affect the tibial slope.

What is the Safe Distance Between Hip and Knee Implants to Reduce the Risk of Ipsilateral Metachronous Periprosthetic Joint Infection?

BACKGROUND: Periprosthetic joint infection (PJI), the most common cause of revision after TKA and THA, is a devastating complication for patients that is difficult to diagnose and treat. An increase in the number of patients with multiple joint arthroplasties in the same extremity will result in an increased risk of ipsilateral PJI. However, there is no definition of risk factors, micro-organism patterns, and safe distance between knee and hip implants for this patient group. QUESTIONS/PURPOSES: (1) In patients with hip and knee arthroplasties on the same side who experience a PJI of one implant, are there factors associated with the development of subsequent PJI of the other implant? (2) In this patient group, how often is the same organism responsible for both PJIs? (3) Is a shorter distance from an infected prosthetic joint to an ipsilateral prosthetic joint associated with greater odds of subsequent infection of the second joint? METHODS: We designed a retrospective study of a longitudinally maintained institutional database that identified all one-stage and two-stage procedures performed for chronic PJI of the hip and knee at our tertiary referral arthroplasty center between January 2010 and December 2018 (n = 2352). Of these patients, 6.8% (161 of 2352) had an ipsilateral hip or knee implant in situ at the time of receiving surgical treatment for a PJI of the hip or knee. The following criteria led to the exclusion of 39% (63 of 161) of these patients: 4.3% (seven of 161) for incomplete documentation, 30% (48 of 161) for unavailability of full-leg radiographs, and 5% (eight of 161) for synchronous infection. With regard to the latter, per internal protocol, all artificial joints were aspirated before septic surgery, allowing us to differentiate between synchronous and metachronous infection. The remaining 98 patients were included in the final analysis. Twenty patients experienced ipsilateral metachronous PJI during the study period (Group 1) and 78 patients did not experience a same-side PJI (Group 2). We analyzed the microbiological characteristics of bacteria during the first PJI and ipsilateral metachronous PJI. Calibrated, full-length plain radiographs were evaluated. Receiver operating characteristic curves were analyzed to determine the optimal cutoff for the stem-to-stem and empty native bone distance. The mean time between the initial PJI and ipsilateral metachronous PJI was 8 ± 14 months. Patients were followed for a minimum of 24 months for any complications. RESULTS: The risk of ipsilateral metachronous PJI in the other joint secondary to a joint implant in which PJI develops can increase up to 20% in the first 2 years after the procedure. There was no difference between the two groups in age, sex, initial joint replacement (knee or hip), and BMI. However, patients in the ipsilateral metachronous PJI group were shorter and had a lower weight (1.6 ± 0.1 m and 76 ± 16 kg). An analysis of the microbiological characteristics of bacteria at the time of the initial PJI showed no differences in the proportions of difficult-to-treat, high virulence, and polymicrobial infections between the two groups (20% [20 of 98] versus 80% [78 of 98]). Our findings showed that the ipsilateral metachronous PJI group had a shorter stem-to-stem distance, shorter empty native bone distance, and a higher risk of cement restrictor failure (p < 0.01) than the 78 patients who did not experience ipsilateral metachronous PJI during the study period. An analysis of the receiver operating characteristic curve showed a cutoff of 7 cm for the empty native bone distance (p < 0.01), with a sensitivity of 72% and a specificity of 75%. CONCLUSION: The risk of ipsilateral metachronous PJI in patients with multiple joint arthroplasties is associated with shorter stature and stem-to-stem distance. Appropriate position of the cement restrictor and native bone distance are important in reducing the risk of ipsilateral metachronous PJI in these patients. Future studies might evaluate the risk of ipsilateral metachronous PJI owing to bone adjacency. LEVEL OF EVIDENCE: Level III, therapeutic study.

What is the rate of successful closed reduction of dislocated dual mobility cups following complex revision hip arthroplasty?

PURPOSE: The aim of this study was to assess the difference in success rates of closed reduction in septic and aseptic revision total hip arthroplasty (THA) performed with a dual mobility (DM) implant. Our objective was to answer the following questions: (1) Is there a difference in success rates of closed reduction between septic and aseptic revision THA with a DM implant? (2) Is closed or open reduction more successful in preventing re-dislocation? METHODS: Between January 2009 and October 2021, 924 revisions were performed with a DM implant. All patients presenting to our institution with a dislocation following septic or aseptic revision THA using a cemented DM cup were included in this study. We analyzed 106 cases of dislocation in 74 patients. For all patients, we collected reason for revision, and classified index surgery as septic or aseptic. RESULTS: Overall, 106 dislocations occurred (106/924, 11.5%). Thirty-nine cases (52.7%) had a dislocation after a septic exchange THA, while in 35 patients (47.3%), a dislocation occurred after an aseptic rTHA. In 29 patients (39.2%), successful closed reduction under general anesthesia was feasible, while the majority of cases required open reduction. In 31 of these patients (67.4%), open reduction was combined with a revision arthroplasty. CONCLUSIONS: In case of DM cup dislocation, there is a low success rate of closed reduction. To prevent re-dislocation, total revision leads to a significantly reduced risk compared to open or closed reduction alone. Careful X-ray analysis for a halo sign showing intra-prosthetic DM cup dislocation is mandatory to avoid futile reduction attempts. LEVEL OF EVIDENCE: III.

High accuracy of a new robotically assisted technique for total knee arthroplasty: an in vivo study.

PURPOSE: Over the last decade, robotic TKA gained popularity for improving the accuracy of implant positioning and reducing outliers in limb alignment comparing to conventional jig-based TKA. Hypothesis of this study was that this newly designed robotically assisted system will achieve a high level of accuracy for bone resection. Purpose of the study was to evaluate the accuracy of the system. METHODS: For this study, 75 knees in 75 patients were operated using a new, robotic system (ROSA® Knee System; Zimmer Biomet, Warsaw, IN) with a Posterior Stabilized Total Knee Arthroplasty (Persona® Knee System). The planned, validated and measured angles and cuts for the distal and posterior femur, for the proximal tibia and for the final coronal alignment on long standing x-rays were compared. RESULTS: A statistically significant difference was found only between the average planned and the average validated angle for femoral flexion, tibial coronal axis, medial and lateral cuts; the average difference was in any case below 1 mm or under 1 degree with SD < 1. No statistical difference was found between planned validated and measured cuts. Average difference between planned HKA and measured was 1.2 ± 1.1. No statistically significant difference was found. CONCLUSIONS: The results of this study demonstrated that using this new surgical robot in total knee arthroplasty it is possible to perform accurate bone cuts and to achieve the planned angles and resections.

Successful eradication rate following one-stage septic knee and hip exchange in selected pre-operative culture-negative periprosthetic joint infections.

PURPOSE: The main requirement for performing the one-stage septic exchange is the pre-operative identification of the pathogen and its susceptibility. The purpose of this study is to evaluate the success rate with special focus on reinfection in a cohort of patients who underwent one-stage septic knee or hip revision for pre-operative culture-negative PJI. METHODS: We retrospectively analyzed 640 patients treated by one-stage revision for chronic knee or hip PJI between January 1, 2016, and December 31, 2018. Only cases with pre-operative culture-negative PJI, with culture-negative synovial aspirations and one negative open biopsy, were analyzed. We evaluated the septic and aseptic complication and the rate of complication-free survival defined as the time from the date of first operation and the date of complication events. RESULTS: A total of 22 patients fulfilled the inclusion and were enrolled. The mean age of the group was 73.2 ± 9.8 years, with a median ASA score of 3 (range 3-4). After mean follow-up of 3.6 ± 2.6 years, 86.4% (19 out of 22) of patients reported no complications. Two patients (9.1%) after one-stage hip required revision arthroplasty due to septic failure, while one patient (4.5%) with one-stage knee had revision for femoral component aseptic loosening. CONCLUSION: Our analysis suggests that the absence of pre-operative pathogen detection may not be contraindication to the one-stage revision in selected patients. The one-stage exchange might be considered in patients with pre-operative negative cultures in presence of ASA > 3 and multiple comorbidities that are not able to tolerate multiple surgeries.

A well performing medial fixed bearing UKA with promising survivorship at 15 years.

BACKGROUND: Unicompartmental knee arthroplasty (UKA) accounts for 10% of knee arthroplasty procedures in Europe. Fixed bearing UKA designs have shown favorable survivorship in registries when compared with mobile bearings. This study analyses long-term follow-up of patients with a medial fixed bearing metal backed tibial UKA and reports 15 years survivorship and clinical outcomes. METHODS: Data were collected prospectively for 148 medial unicompartmental fixed bearing metal backed UKAs implanted in 148 patients in two high volumes knee arthroplasty centers between January 2005 and December 2007. The indication was osteoarthritis in all but 2 patients. Patients' reported outcome scores were documented at last follow up. The mean patient age at time of surgery was 65 years. RESULTS: At final follow up, outcome and survivorship data were collected for 124 medial fixed bearing UKAs. Thirteen patients underwent revision; average time to revision was 77 months (SD 35.31). The Kaplan-Meier analysis demonstrated a survivorship of 97.65% at 69 months and of 89,52%. at 120 months and 173 months of follow-up. When revisions for infection were excluded, the survivorship of the implant was 90.3% at the last of follow up. The mean OKS was 43.02 (SD 5.1) at the last follow-up, and the mean FJS was 77.6 (SD 6.9). CONCLUSION: This Medial fixed bearing metal backed UKA demonstrates promising long-term survivorship and patient outcomes. It appears to be a suitable and reasonably lasting option for the treatment of medial compartment OA.

A new robotically assisted technique can improve outcomes of total knee arthroplasty comparing to an imageless navigation system.

BACKGROUND: Robotic assisted total knee arthroplasty (RTKA) has shown improved knee alignment and reduced radiographic outliers. However, there remains debate on functional outcomes and patient-reported outcomes (PROMs). This study compares the 1-year clinical outcomes of a new imageless robotically assisted technique (ROSA Knee System, Zimmer Biomet, Warsaw, IN) with an imageless navigated procedure (NTKA, iAssist Knee, Zimmer, Warsaw, IN). METHODS: The study is a retrospective analysis of prospectively collected data that compared the functional outcomes and PROMs of 50 imageless RTKA with 47 imageless NTKA at 1-year follow-up. Baseline characteristics, intraoperative and postoperative information were collected including complications, revisions, Knee Society Score (KSS), Knee injury and Osteoarthritis Outcome Score (KOOS) score, and Forgotten Joint Score (FJS-12). Radiographic analysis of preoperative and postoperative images evaluating hip-knee-ankle (HKA) angle was performed. RESULTS: There was no difference regarding baseline characteristics between the groups. Mean operative time was significantly longer in the RTKA group (122 min vs. 97 min; p < 0.0001). Significant differences were reported for the "Pain" (85 [RTKA] vs 79.1 [NTKA]; p = 0.0283) subsection of the KOOS score. In addition, RTKA was associated with higher maximum range of motion (119.4° vs. 107.1°; p < 0.0001) and better mean improvement of the arc of motion by 11.67° (23.02° vs. 11.36°; p < 0.0001). No significant differences were noted for other subsections of KOOS, KSS, FJS-12, complications, or limb alignment at 1-year follow-up. CONCLUSIONS: Imageless RTKA was associated with longer surgical time, better pain perception and improved ROM at 12-month follow-up compared with NTKA. No significant differences were reported on other PROMs, complication rates and radiographic outcomes. LEVEL OF EVIDENCE: III.

What is the concordance rate of preoperative synovial fluid aspiration and intraoperative biopsy in detecting periprosthetic joint infection of the shoulder?

BACKGROUND: The accuracy of preoperative synovial fluid culture for microbe detection in shoulder periprosthetic joint infection (PJI) is poorly described. To evaluate the utility of preoperative culture data for early pathogen identification for shoulder PJI, we determined the concordance between preoperative synovial fluid culture results and intraoperative tissue culture results. METHODS: Fifty patients who met the 2014 Musculoskeletal Infection Society criteria for shoulder PJI between January 2016 and December 2019 were retrospectively reviewed for clinical and demographic data. This cohort of patients was divided into 2 groups based on the concordance between preoperative and intraoperative culture results. The pathogens identified on preoperative and intraoperative cultures were classified as high-virulence or low-virulence. Student's t tests and Mann-Whitney U tests were used as appropriate for continuous variables, and χ2 and Fisher's exact tests were used as appropriate for categorical variables. RESULTS: Concordance between preoperative aspiration and intraoperative tissue culture was identified in 28 of 50 patients (56%). Preoperative cultures positive for Gram-positive species were more likely to be concordant than discordant (P = .015). Preoperative cultures positive for Cutibacterium acnes were more likely to be concordant with intraoperative cultures (P = .022). There were more patients with polymicrobial infection in the discordant group compared with the concordant group (P < .001). No statistically significant correlation between the preoperative serum C-reactive protein level and the intraoperative category of bacteria was reported. Staphylococcus aureus and coagulase-negative Staphylococci were associated with high specificity and negative predictive value. Preoperative cultures positive for C. acnes demonstrated sensitivity, specificity, positive predictive value, and negative predictive value lower than 0.8. Gram-negative pathogens demonstrated the highest sensitivity (1) and specificity (1), whereas polymicrobial infections exhibited the lowest sensitivity and positive predictive value. CONCLUSION: Preoperative synovial fluid aspiration for shoulder PJI poorly predicts intraoperative culture results, with a discordance of 44%. More favorable concordance was observed for monomicrobial preoperative cultures, particularly for Gram-negative organisms and methicillin-sensitive S. aureus. The overall high rate of discordance between preoperative and intraoperative culture may prompt surgeons to base medical and surgical management on patient history and other factors and avoid relying solely on preoperative synovial fluid culture data.

Is the risk of periprosthetic joint infection in patients undergoing total hip and knee joint arthroplasty in the multi-unit operating room higher than in the classical single-unit operating room?

BACKGROUND: This study was performed to answer the question: Is the risk of PJI in patients undergoing primary TKA and THA in multi-unit OR higher than in a classical single-unit OR? We hypothesized that the risk of PJI following TKA and THA is not associated with the OR type. METHODS: We reviewed the medical records of all cases of THA and TKA in our centre, between January 2015 and September 2018, in our single- and multi-unit OR. A total of 8674 patients met the inclusion criteria. Patients were divided into two groups: group 1, surgery in the multi-unit OR (n = 8282); group 2, surgery in the single-unit OR (n = 450). The infection rate between both groups was compared using chi-square test. RESULTS: There was no significant difference between both groups regarding the septic revision rate at three (p = 0.1 and 0.58 respectively) and six months post-operatively (p = 0.22 and 0.7 respectively). In group 1, five patients after TKA and 4 patients after THA were revised within three months. At six months, 11 patients after TKA and six patients after THA required revision surgery. In group 2, one patient after TKA and one patient after THA were revised within three months. At six months, one patient after TKA and one patient after THA underwent revision surgery. CONCLUSION: The incidence of SSI does not differ significantly based on OR design in patients undergoing TKA and THA. The number of patients per surgical table in multi-unit OR is higher than in the single-unit OR. This shows that more number of surgeries can be achieved in multi-unit OR and as safe as single-unit OR.

A ligament tensor-guided extramedullary alignment technique for distal femoral cut in total knee replacement: results at a minimum 3 years follow-up.

BACKGROUND: Femoral intramedullary canal referencing is used by most knee arthroplasty systems for distal femoral cut; to avoid the opening of the femoral canal different solutions have been presented such as navigation, patient-specific instruments (PSI) or the use of an extramedullary device. The FuZion® system is a tensor device, created to merge the two main techniques for performing a total knee arthroplasty: the ligament balancing and measured resection techniques. Our idea was to use the tensor as an extramedullary cutting guide for the distal femoral cut, based on a 90° tibial resection. METHODS: A total of 110 patients were operated on with this technique. Patients were evaluated with weight-bearing long-standing X-rays, knee a-p and lateral views, validated PROMs (Oxford Knee Score, EQ-5D and EQ-VAS), the Knee Society Scoring System (KSS) and the Forgotten Joint Score (FJS). Minimum follow up was 3 years (range 38-50 months). RESULTS: Complete results were available for 104 patients (5 were lost in follow up and 1 died). Significant improvements were registered for all the evaluated scores from pre-op to the final follow up. Pre-op long-standing X-rays showed 21 valgus knees (20%) with a mean HKA of 187.6° (± 3.2°), 70 varus knees (62%) with a mean 172.2° (± 3.7°) HKA and 19 neutrally aligned knees, with a mean HKA of 179.5° (0 ± 2°). The radiographic evaluation at 3 months post-op showed 20 valgus knees (mean HKA 183.7° ± 1.5°), 67 varus knees (mean HKA 176.1° ± 1.8°) and 23 neutrally aligned knees with a mean HKA of 179.3° (0 ± 2°). At final follow up the survival rate was 100% for revision of the implant as the endpoint. With any reoperation as the endpoint Kaplan-Meier survival estimate showed a survival rate of 95.1% at 3 years. CONCLUSIONS: This technique for performing a ligament driven alignment in total knee arthroplasty showed encouraging clinical outcomes at mid-term follow up leaving a residual deformity on the coronal plane.

Simultaneous bilateral reverse shoulder arthroplasty for bilateral four-part fracture of the proximal humerus in an elderly patient: A case report.

BACKGROUND: Proximal humeral fracture is the third most common fracture in elderly people after fractures of proximal femur and distal radius. They typically occur after low-energy trauma in women affected by osteoporosis, bilateral involvement is rare and usually with a simple pattern of fracture. Bilateral four-part proximal humerus fractures are even less frequent, with only a few reports published previously, with all of them caused by a seizure or electrocution in patients < 65 years old. CASE PRESENTATION: We present a 77-year-old right-handed female that sustained a bilateral simultaneous four-part humeral fracture secondary to accidental slip-and-fall occurred at home. Patient was treated with simultaneous bilateral Reverse Shoulder Arthroplasty (RSA) in our structure. Functional assessment was undertaken at 6- and 12-months follow-up (FU) after surgery, using the Constant-Murley score (CMS) and the Disabilities of the Arm, Shoulder and Hand (DASH) score. OUTCOME: The simultaneous RSA procedure was well tolerated by the patient. Post-operative course was optimal with relatively low blood loss, rapid functional recovery, and fast pain relief. The CMS and DASH score were reasonably good at 6-months FU (right-left: 39-57 and 50.8-30.5, respectively) and they further improved at 1-year FU (right-left: 66-82 and 35.8-19.2, respectively). X-rays showed good position of the implants with no evidence of scapular notching at 1 year. Patient rated the overall satisfaction as good. DISCUSSION: Bilateral four-part proximal humeral fractures are complex injuries difficult to manage. Optimal treatment is controversial, and it can be conservative or surgical, varying from open reduction and internal fixation (ORIF) to arthroplasty. However, this last option is still directed to only one side, preferring ORIF or conservative treatment for the contralateral. In case of comminute and displaced fractures, low bone quality, rotator cuff deficiencies and eccentric osteoarthritis, RSA is to prefer as a surgical option. For these reason, in selected cases of bilateral four parts proximal humerus fracture, especially when occurs in elderly patients, the simultaneous RSA implantation can represent a valid option to achieve an adequate functional result and a fast recovery. This is the first description, to our knowledge, in English literature of a simultaneous bilateral RSA.