The effect of high tibial osteotomy and unicompartmental knee arthroplasty on patellofemoral joint in young patients with medial knee arthrosis.

INTRODUCTION: Osteoarthritis of the knee is a debilitating disease. In most cases, only the medial compartments are affected. High tibial osteotomy (HTO) and unicompartmental knee arthroplasty (UKA) are the two main procedures commonly used in the surgical treatment of unicompartmental knee osteoarthritis patients not responding to conservative treatment. The aim of our study was to compare UKA and biplanar medial open-wedge HTO in terms of patellofemoral changes and functional score in patients under 60 years of age with medial compartment arthrosis. MATERIALS AND METHODS: A retrospective study. A total of 79 patients (37 HTO, 42 UKA) who received one of the two treatments in a single center were examined preoperatively and at a single postoperative follow-up. Posterior tibial slope, lateral patellofemoral angle (LPFA), Q-angle, patellar height, Cincinnati Rating System and Knee Injury and Osteoarthritis Outcome Score (KOOS) functional scores were evaluated in all patients preoperatively and at the 6-month follow-up examination. RESULTS: Insall-Salvati ratio remained stable in the HTO group, while there was a minor decrease in the UKA group and the changes between the groups were not statistically significant. Caton-Deschamps ratio increased in the UKA group and decreased in the HTO group, and this change was statistically significant (p < 0.001). LPFA did not change in the UKA group in the postoperative period, while it increased in the HTO group (p < 0.001). Changes in Q angle and Cincinnati Rating System scores were statistically similar between the UKA and HTO groups (p = 0.827 and p = 0.340). CONCLUSIONS: In our study, biplanar medial open-wedge HTO and UKA performed with appropriate surgical technique had no negative effect on patellofemoral joint. In patients under 60 years of age with medial compartment osteoarthritis of the knee, both surgical treatments can be performed with appropriate patient selection.

The Traditional Intramedullary Axis Underestimates the Medial Tibial Slope Compared to Transmalleolar Sagittal Axis in Image-based Robotic-Assisted Unicompartimental Knee Arthroplasty.

The medial unicompartmental knee arthroplasty (mUKA) has been recognized as an excellent treatment for medial knee osteoarthritis. The posterior tibial slope (PTS) is measured radiographically with the intramedullary axis (IMA) to the tibial baseplate on the sagittal plane radiograph. However, in most computer-navigated or robotic mUKAs, the PTS is set from a transmalleolar axis (TMA).The PTS difference was evaluatedbetween the sagittal TMA and the sagittal IMA of patients undergoing a CT-based primary robotic-assisted mUKA.We retrospectively reviewed the preoperative computed tomography (CT) scans taken according to the MAKO system protocol (Stryker) of 67 patients undergoing mUKAs. We measured the angular difference between the IMA and the TMA in the sagittal plane.Using the TMA to set the PTS the estimation of the slope of the medial tibial plateau would increase by an average of 1.9 ± 3.2 degreescompared to the IMA. Furthermore, in nineknees, PTS was decreased.Tibial components implanted with the help of a CT scan-based preoperative planning MAKO will show an average of 1.9 degrees more than those measured on sagittal radiographs potentially of concern for knee kinematics. A universal language is needed to standardize the slope calculation and the respective reference axis used.

Individualized megaimplants in acetabular revision arthroplasty: what have we learned in the last 15 years?

Acetabular revision arthroplasty, a demanding field of reconstructive hip surgery, calls for innovative strategies to deal with challenging bone defects and implant failure seen in revision cases. Conventional implant solutions might fall short of adequately addressing severe bone loss and ensuring stable fixation, highlighting the necessity of customized strategies. Personalized megaimplants, distinguished by their tailor-made design and large-scale construction, present a viable option to overcome these challenges. The present article provides an elaborate analysis of custom-made megaimplants in acetabular revision arthroplasty, shedding light on the underlying principles, design complexities, manufacturing methods, applications in the clinical setting, and outcome assessment. The aim of this review is to present a comprehensive insight into personalized megaimplants and their contribution to the advancement of orthopedic surgery.

What Is the Rate of Antimicrobial Resistance of a Prosthetic Joint Infection in a Major Orthopaedic Centre?

Periprosthetic joint infections (PJIs) are important factors in decreasing the success of hip and knee arthroplasties. It is a necessity to explore the epidemiological data and develop applications for rational antibiotic use, to address future infection control concerns. We aimed to investigate the microorganisms that were responsible and the related antibiograms in 121 patients with PJI, who were managed by two-stage revision surgery. Patients' data records, demographics, comorbidities, sites of arthroplasty, synovial fluid and deep tissue culture results and antibiotic treatment were summarized on a standardized case report form. There were 43 (35.5%) culture-negative PJI cases and 12 (9.9%) polymicrobial growths. The causative pathogens included Gram-positive (50.4%) and Gram-negative microorganisms (23.1%) and fungi (0.8%). Methicillin resistance was 64.3% for S. aureus and 89.5% for coagulase-negative staphylococcus (CoNS). The extended spectrum beta lactamase (ESBL) rate for Enterobacteriaceae was 68.4%. This study shows that antibiotic resistance is encountered in more than half of the cases, which is valid for all microorganisms most common in PJI. The success of treatment decreases significantly in cases where antibiotic-resistant microorganisms are isolated or in cases where the culture is negative.

Long-term outcomes of first metatarsophalangeal hemiarthroplasty for hallux rigidus.

Hallux rigidus (HR) is arthritis of the first metatarsophalangeal joint.First metatarsophalangeal joint hemiarthroplasty surgery is one of the treatment options for end stage hallux rigidus.The aim of this study is to evaluate the long-term outcomes of hemiarthroplasty of the first MTPJ with a metallic implant in patients with end-stage HR. Patients who underwent hemiarthroplasty surgery with the diagnosis of HR were included in the study. Self-Administered Foot Evaluation Questionnaire (SAFE-Q) and Foot and Ankle Disability Index (FADI) scores were used in pre-operative and post-operative final follow-ups to evaluate the clinical status of the patients. Post-operative 1st metatarsophalangeal joint range of motion was measured and recorded separately for each patient. The intra-hospital and follow-up complications and revision surgeries of the patients were recorded. Thirty-five patients with a mean follow-up of 8.1 years were included in the study. There was a statistically significant positive change in both FADI and SAFE-Q scores compared to the pre-operative process(p = 0.0001). The average dorsiflexion angle at the final follow-up was 22.0 ± 8.2. Thus, it was determined that the 5-year and 8-year survival rates of patients in this study were 97.1% and 87.8%, respectively. In conclusion, the long-term results show that the use of hemiarthroplasty in the treatment of end-stage HR leads to high patient satisfaction, increased range of motion and a high survival rate.

Organism profile and C-reactive protein (CRP) response are different in periprosthetic joint infection in patients with hepatitis.

PURPOSE: Hepatitis B and C are important and relatively common health issues. It is known that many patients who underwent total knee and hip arthroplasty were also diagnosed with hepatitis. These patients are at higher risk of periprosthetic joint infection (PJI). This study aimed to investigate the differences in PJI cases in hepatitis B and C patients. METHODS: This is a retrospective case-controlled single-center study. A total of 270 patients with hepatitis and non-hepatitis (control group) who underwent one-stage septic exchange to the hip and knee joints were included in the study. All patients' previous surgical histories, infective organisms, C-reactive protein (CRP) values before septic exchange, and demographic data were evaluated. All microbiological and laboratory evaluations were performed separately for knee and hip arthroplasty. RESULTS: The mean CRP levels of Hep B- and C-positive patients, who underwent one-stage septic exchange in the knee joint, were 23.6 mg/L. In the control group, this value was 43.1 mg/L and a statistically significant difference was found between the groups (p = 0.004). Gram-negative organisms were identified in a larger proportion of patients with hepatitis who developed PJI in both hip and knee joints and underwent one-stage septic exchange (p = 0.041/p = 0.044). CONCLUSION: PJIs caused by Gram-negative bacteria are encountered more frequently in patients with hepatitis than in the control group. In addition, the CRP rise is less in patients with hepatitis compared to PJI cases in the control group. Patient-specific evaluation is required in cases of PJI in patient groups with co-existing hepatitis.

Is large unstained cell percentage (%LUC) a novel diagnostic marker for periprosthetic joint infections?

BACKROUND: Periprosthetic joint infection (PJI) is a very important complication that occurs after total joint replacement. Diagnosing PJI is at least as difficult as this disease. There is no biomarker that alone can diagnose PJI. OBJECTIVE: This study aimed to evaluate the effectiveness of large unstained cell percentage (%LUC) in diagnosing PJI and deciding on re-implantation in two stage septic exchange arthroplasty. METHODS: Patients who underwent revision arthroplasty between 2019 and 2023 were screened retrospectively. These patients were grouped as those who underwent two-stage septic exchange and those who underwent aseptic exchange. Prosthesis removal from the patients who underwent two-stage septic exchange, before spacer application, and on the 3rd post-operative day after spacer application, Blood parameters were collected at the 1st month and before the second stage after the spacer application, and before the revision surgery from the patients who underwent aseptic exchange. White blood cell, neutrophil percentage, %LUC, albumin, sedim and CRP values were checked and recorded one by one from all patients. RESULTS: The data of a total of 233 patients, including 133 patients in the two stage septic exchange group and 100 patients in the aseptic exchange group, were included in the study. When the predictive value of %LUC in PJI was accepted as cut-off 1.75, the sensitivity was 69.2% and the specificity was 73%. The change in %LUC over time in patients who underwent two-stage septic exchange was statistically significant (p= 0.0001). A positive correlation was found between the value of .%LUC after spacer application and the value of CRP before prosthesis protrusion/spacer application surgery, and the Spearman correlation coefficient was found to be 0.005. CONCLUSION: %LUC value can be a promising biomarker for the diagnosis of PJI by considering both sensitivity and specificity rates. Apart from this, it is an easily accessible and effective biomarker for re-implantation decision making and evaluation of response to treatment, especially in two-stage septic exchange surgeries.

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.

Six years of experience with the nationwide newborn ultrasonographic hip screening program in Turkey: a considerable change in the type of surgical interventions in developmental dysplasia of the hip.

This study aims to assess whether the nationwide newborn ultrasonographic hip screening program has influenced the rate of different types of surgical interventions performed in developmental dysplasia of the hip (DDH) in children in Turkey. A retrospective analysis of the nationwide data obtained from the National Registry System between January 1, 2015, and December 31, 2020, was carried out. The rate of minor and major surgical interventions was calculated by dividing the total number of primary closed/open reductions with or without tenotomies and the total number of primary pelvic or periacetabular osteotomies with or without femoral osteotomies by the total number of live births in the country per year, respectively. The rates of primary minor surgical interventions were found to be 0.47/1000 in 2015, 0.71/1000 in 2016, 1.07/1000 in 2017, 1.00/1000 in 2018, 1.06/1000 in 2019, and 0.89/1000 in 2020. The rates of primary major surgical intervention were found to be 0.74/1000 in 2015, 0.40/1000 in 2016, 0.33/1000 in 2017, 0.31/1000 in 2018, 0.32/1000 in 2019, and 0.21/1000 in 2020. The introduction of the nationwide newborn hip screening program has significantly changed the surgical treatment modalities in children with DDH. A nearly twofold increase in the rate of primary closed/open reduction and hip spica casting and nearly a three-quarter decrease in the rate of primary bony procedures were observed within 6 years.

An overview of the orthopedic patient profile in the first five days following February 6th, 2023 Kahramanmaras earthquake: A single-center experience in the earthquake zone.

OBJECTIVES: This study aims to investigate the patient profile at a medium-volume hospital located in the earthquake zone among patients who received orthopedic treatment within the first five days after the natural disaster that was considered a major earthquake. PATIENTS AND METHODS: Between February 6th, 2023 and February 10th, 2023, a total of 338 patients (156 males, 182 females; mean age: 42.2±9.7 years; range, 0 to 87 years) who received orthopedic treatment in our center were retrospectively analyzed. The patients were divided into four groups according to age as follows: infants (younger than one year of age), children (one to 13 years), adults (14 to 59 years), and elderly (60 years or older). RESULTS: Considering the age distribution, 291 (86%) patients were young adults. A total of 173 orthopedic surgeries were performed, including internal fixation in 63 patients, external fixation in 11 patients, upper/lower extremity fasciotomy in 47 patients, amputation in 39 patients, and soft tissue debridement in 13 patients. CONCLUSION: It is of utmost importance to recognize the principles of emergency fracture fixation and fasciotomy to successfully perform orthopedic surgeries after a natural disaster such as a major earthquake, particularly when the number of earthquake victims is considerably high.

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.

Setting the Tibial Component Rotation Based on Femoral Landmarks Allows Congruent Knee Kinematics in Robotic-Assisted Medial Unicompartmental Knee Replacement.

The accurate positioning of the prosthetic components is essential for achieving successful results in medial unicompartmental knee arthroplasty (mUKA). The tibial component rotation in image-based robotic-assisted UKA is usually based on tibial bony landmarks matched to the pre-operative CT model. The study aimed to evaluate whether setting the tibial rotation on femoral CT-based landmarks allows congruent knee kinematics. We retrospectively analyzed data from 210 consecutive image-based robotic-assisted mUKA cases. In every case, we set the tibia rotation landmark parallel to the posterior condylar axis and centered it on the trochlea groove defined on the preoperative CT scan. The implant positioning was primarily set parallel to this rotation landmark and then adjusted based on tibial sizes avoiding component over- or under-hang. During surgery, we recorded the knee kinematics under valgus stress to reduce the arthritic deformity. A femoral-tibial contact point was recorded over the entire range of motion and displayed as a tracking profile on the tibia implant. The femoro-tibial tracking angle (FTTA) was then calculated based on a tangent line to the femoro-tibial tracking-points and the difference to the femur-based rotation landmark. In 48% of the cases, we could position the tibia component exactly to the femoral rotation landmark, whereas in 52% of cases, minimal adjustments were made to avoid component's under- or over-hang. The mean tibia component rotation (TRA) with reference to our femur-based landmark was +0.24° (SD ± 2.9°). The femur-based tibia rotation landmark showed a high correspondence to the FTTA with 60% of the cases having less than 1° of deviation. Mean FTTA was +0.7° (SD ± 2.2°). The mean difference between the absolute value of the TRA and the FTTA (|TRA| - |FTTA|) was -0.18° (SD ± 2°). Setting the tibial component rotation based on CT scan femoral landmarks and not on tibial anatomical landmarks is a reliable method to obtain congruent knee kinematics during image-based robotic-assisted medial UKA with less the 2° deviations on average.

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.

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.

The anatomical shape of the proximal femur correlates with the distal femur anatomy.

PURPOSE: In the case of stemmed implants for lower limb joint arthroplasty procedures, implant stability and survivorship generally rely on the strength of fixation in the medullary canal regardless of whether the procedure is primary or revision surgery. This study aimed to investigate the relationship between the proximal (Dorr classification) and distal (Citak classification) femoral canal geometry classification systems. METHODS: A total of 200 patients who received standing long leg radiographs (hip to ankle) at our institution were identified using our institutional electronic radiology database. Patients were recruited into 4 groups. There were 100 male and 100 female patients with each of those being split into 50 right-sided and 50 left-sided long-leg standing anteroposterior (AP) radiographs. Two independent, blinded observers reviewed each radiograph on two separate occasions, with a minimum of a one-week interval between sittings to review each respective radiograph. RESULTS: No statistically significant correlation was found between demographic data and clinical measurements. A statistically significant correlation was found between the patient's age and BMI results and Citak and Dorr measurements. There was excellent inter-observer and intra-observer agreement for the Citak and Dorr Classifications. The mean Cronbach's α coefficient was 0.96 (range 0.93-0.98) for the Citak Classification and 0.95 (range 0.83-0.97) for the Dorr Classification. There was also an excellent intra-observer agreement with 95% average pairwise per cent agreement for the Citak Classification and 95% average pairwise per cent agreement for the Dorr classification. A statistically significant positive correlation was found between Dorr Calcar Isthmus and Citak Ratio (p < 0.05). CONCLUSION: In this study, the Dorr and Citak classifications are put into relation to each other for the first time. The morphology of the femur was investigated in its entirety and it was shown that there was a positive correlation between the anatomical shape of the proximal and distal medullary canals.

Anatomical risk factors for aseptic loosening of full hinge knee prosthesis in primary and revision TKAs.

INTRODUCTION: Risk factors (RF) associated with aseptic loosening (AL) in total knee arthroplasty (TKA) are poorly understood. Therefore, the aim of this study was to investigate the anatomical shape variations in relation to the inner-diameter of the femur and the tibia as prognostic RF for AL of full hinge prosthesis (FHP) in primary and revision TKA. MATERIALS AND METHODS: We retrospectively examined all patients, who underwent revision surgery (2003-2018) due to AL of the FHP in primary (n = 38) and revision TKA (n = 46). Diagnosis-appropriate controls without AL at minimum follow-up of 24 months were randomly collected for each group. Besides other risk factors, we also measured the inner diameter of the femur according to the Citak classification and of the tibia on anteroposterior radiographies. RESULTS: RF for AL are younger age in primary and revision as well as > 1 previous surgeries in revision TKA. The femoral index was shown to be a RF for AL in revision TKA (p = 0.001), but not in primary TKA. The novel tibial index was associated with AL in primary with AUC 0.776 (95% CI 0.67, 0.88), 65.8% sensitivity, 86.6% specificity and in revision TKA with AUC 0.817 (95% CI 0.73, 0.91), 82.6% sensitivity and 71.7% specificity. CONCLUSION: This is the first study to calculate the tibial measurements and the tibial index according to Citak et al. and to identify them as prognostic RF for AL of the full hinge knee prosthesis in TKA and confirm the femoral index as a RF for AL also in revision full hinge knee prosthesis. Therefore, the preoperative radiological evaluation should include the analysis of the anatomical shape variants in order to select the appropriate prosthesis design with a possibly enhanced prognosis.

The anatomical shape of the distal femur is an independent risk factor for aseptic loosening following one-stage septic knee revision using rotating hinge knee prosthesis.

PURPOSE: Aseptic loosening (AL) is the second most common reason for failure after one-stage septic knee revision. In this context, the goal of the study is to identify risk factors for AL following one-stage septic knee revision using rotating hinge implants. We aimed to answer the following research question: How does the anatomical shape of the distal femur represent an independent risk factor for AL following one-stage septic knee revision arthroplasty? METHODS: Patients, who had undergone re-revision surgery due to AL of the rotating hinge knee prosthesis after one-stage septic knee revision arthroplasty between January 2008 and December 2018, were included. For this purpose, 41 patients with AL after one-stage septic knee revision using rotating hinge implants and 37 controls without any revision surgery at latest follow-up were included in this study. Using standardized anteroposterior (AP) views of the knee in all patients, we measured the inner diameter of the femur 20 cm proximally from the joint line and at a point 2 cm proximally from the adductor tubercle. RESULTS: Among the vast majority of AL cases, we identified an isolated loosening of the femoral component. The AL group showd a high distribution of the Type C according to the Citak classification with 75.7%. Contrary to this, with 24.3% (p < 0.001) the amount of Type C cases was relatively low in the control group. Consequently, Type C configurations of the distal femur represent an independent risk factor for AL with an approximately sevenfold higher risk for AL compareed to Type A and Type B. CONCLUSIONS: The novel radiological classification system of the distal femur shows that the Type C subtype is an independent and main risk factor for AL after one-stage septic knee revision using rotating hinge knee implants.

Validity of the Novel Radiological Classification System of the Distal Femur.

OBJECTIVE: Aseptic loosening (AL) is among the most important causes of failure after total knee arthroplasty (TKA). However, while there are numerous underlying causes of AL, the morphometry of the distal femur and intramedullary canal has not been sufficiently demonstrated. This study aimed to show the interobserver and intraobserver reliability and validity of the Citak classification, which has been recently defined according to the morphometry of the distal femur and provides a risk factor definition for AL. MATERIALS AND METHODS: A total of 200 patients whose standardized anteroposterior (AP) and lateral images of the knee joint were obtained between October 2019 and April 2020 were retrospectively evaluated in this study. Patients with a history of extra-articular deformity and knee surgery were excluded from the study. For AL, morphologies of the distal femur were identified by two observers using the new radiological classification system of the distal femur. Mean pairwise Cronbach's alpha coefficient was used to assess the intra- and interobserver agreement of the classification. RESULTS: There was excellent interobserver agreement for the 20 cm proximal and 2 cm proximal to the lateral joint line (PLJL) and adductor tubercle (PAD), respectively. The mean Cronbach's alpha coefficient was 0.96 (range 0.764-0.944) for the PAD and 0.98 (range 0.734-0.929) for the PLJL. There was also an excellent intraobserver agreement, with 93% average pairwise percent agreement for the index group and 95.5% average pairwise percent agreement for the anatomical classification group. CONCLUSIONS: The level of inter- and intraobserver agreement for the morphology of the distal femur was excellent in the new radiological classification system, which was shown to be beneficial in the planning of revision knee arthroplasty for AL. However, there is a need for further studies in order to make a correlation of the classification with specific intraoperative findings.

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.

Twenty-year results of a neck-preserving short-stem prosthesis in primary total hip arthroplasty.

PURPOSE: The use of short-stemmed femoral components with preservation of the femoral neck has been advocated for younger and more active patients undergoing joint replacement. This study reports the long-term outcomes of the Collum Femoris-Preserving (CFP) prosthesis on a previous report. METHODS: Between January 1999 and December 2000, a total of 149 patients underwent total hip arthroplasty procedure using the CFP stem in a single institution. At latest follow-up, 79 patients were available and were included in this study. The mean age of the cohort was 73.4 (range, 44-92 years) with a mean follow-up of 20.7 years (range 20-21). The average age was 52.1 years at index procedure (range, 21-71 years). RESULTS: The Kaplan-Meier survivorship free from revision for any cause at 5, 10 and 20 years was 93.2% (87.8-96.3%), 93.2% (87.8-96.3%) and 83.0% (75.7-88.3%), respectively. At 20 years follow-up, the revision for any cause occurred in 26.6% (21 of 79) of patients. The most common causes for revision surgery were aseptic loosening, dislocation, and polyethylene wear with 6.3% (5 out of 79), respectively. Periprosthetic fracture occurred in four patients (5.1%) followed by periprosthetic joint infection in two patients (2.5%). Revision surgery of the femoral stem was required in four patients (5.1%). There was a statistically significant improvement of the Harris Hip Scores from 53 to 83.7 (range 56-91). CONCLUSION: The long-term outcomes of the CFP stem are excellent, demonstrating a low rate of aseptic loosening with an excellent survivorship within 2 decades.