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.

Survival analysis of 3D printed acetabular implants in revision total hip arthroplasty associated with severe pelvic discontinuities.

BACKGROUND: Surgeons still face difficulties when performing aseptic acetabular revision on patients with extensive defects. Advances in three-dimensional printing technology (3DP) have afforded to the surgeons to create a patient-specific implant matching the morphology and topography of the defect. OBJECTIVE: The aim of the current research was to determine the survivorship in the treatment of acetabular bone defects with pelvic discontinuity (PD). METHODS: In order to reconstruct Paprosky type III defects with PD, twenty-three patients underwent revision total hip arthroplasty (THA) utilizing 3D-printed implants (Mobelife). The primary outcomes were the implant-associated failure rate correlated with survivorship. As secondary variables, complications and the effect of age, sex, comorbidities, history of infections and the presence of other lower limb arthroplasties on a new revision were analyzed. RESULTS: Patients were followed out to a mean of 67.22 ± 39.44 months (range, 0.9-127 months). Mobelife implant mean survival was 102.57 ± 9.90 months (95% CI 83.17-121.96). The cohort's implant one-year survival rate was 87%; at ten years, it dropped to 78.3%. There were four revisions: three due to periprosthetic joint infection (PJI) and one case due to aseptic loosening. Cox regression analysis did not identify any variable as predictor of failure. CONCLUSION: The use of 3DP patient-specific acetabular components has shown encouraging results and it is a viable treatment option for addressing acetabular defects with combined PD in aseptic THA revision.

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.

Tranexamic acid administered intraarticularly to the knee is safer for the articular cartilage and anterior cruciate ligament compared to intravenous administration: Histological analysis of an experimental rat model.

In this study, the effects of tranexamic acid (TXA) on the knee's articular cartilage, anterior cruciate ligament (ACL), and joint capsule were assessed histologically. There were 15 rats in each of the 3 groups, totaling 45 rats. Intraarticular (IA) saline injections were applied for the first group, IA TXA injections for the second group, and intravenous (IV) TXA injections for the third group. Using samples taken from the knee joint 3 weeks later, the medial/lateral femoral condyle and medial/lateral tibial plateau articular cartilages were evaluated with Osteoarthritis Research Society International (OARSI) scoring, while ACL diameter and joint capsule thickness were analyzed histologically. In comparisons of OARSI scores for the medial/lateral femoral condyle and medial/lateral tibial plateau cartilage regions, the scores obtained for the IV TXA group were significantly higher than those of the IA saline group (P < 0.001, P = 0.001, P = 0.003, P = 0.011). In comparisons of medial/lateral femoral condyle and medial/lateral tibial plateau OARSI scores, the scores obtained for the IV TXA group were again significantly higher than those of the IA TXA group (P < 0.001, P < 0.001, P < 0.001, P = 0.002). When ACL diameters were compared, a significant decrease was observed in the ACL diameters of the IV TXA group compared to the IA saline and IA TXA groups (P < 0.001, P = 0.039). Histologically, IV TXA damages the articular cartilage and ACL more than IA TXA. IA administration of TXA is more protective when the articular cartilage and ACL are preserved.

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 tranexamic acid safe for the hip joint?

To show the effects of tranexamic acid, which is a drug frequently used to control bleeding, on the hip joint and sciatic nerve in animal experiments. There were 15 rats in each of the 3 groups, with a total of 45 rats. Topical saline injections were applied to the first group, topical TXA injections to the second group, and intravenous (IV) TXA injections to the third group. In the samples taken from the hip joint 3 weeks later, femoral head cartilage, sciatic nerve, and joint capsule thicknesses were analyzed histologically. Statistically significantly more cartilage degradation was detected in the femoral head cartilage in both the IV and intraarticular TXA group when compared to the control group. The groups were also compared in terms of acetabular cartilage; however, no histological difference was found between the groups. It was seen that when the femoral head cartilage thickness (the average of the measurements made from 3 different points were used) was examined, the cartilage thickness in the topical TXA group was less when compared to the other 2 groups. However, this difference was determined to not be statistically significant. The data of the hip joint capsule thickness measurement, it was found that the capsule thickness in the topical TXA applied group was less when compared to the other 2 groups. However, this difference was not statistically significant. When the sciatic nerves in all 3 groups were compared, no different staining characteristics were found in the immunofluorescence examination. TXA, which is frequently used in orthopedic practice, shows negative effects on hip joint cartilage in both topical and intravenous application.

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.

A Novel Radiological Classification System of the Proximal Humerus.

Different anatomical variants have been reported for the proximal and distal femur. Given this context, the goal of our study was to answer the following question: Can we also identify different anatomical variants of the proximal humerus?Two hundred anteroposterior (AP) radiographs of the proximal humerus with an equal gender distribution and equal laterality per gender were reviewed. The metaphyseal diameter of the proximal humerus at the level of the anatomical neck (X) and the intramedullary diameter at 10 cm from the apex of the greater tuberosity (Y) were measured. A new ratio was established, based on both measurements (Y/X). Radiographs showed different anatomical variants: type A: Y/X < 0.3, type B: Y/X = 0.3-0.4, type C: Y/X > 0.4. Two observers reviewed the AP radiographs independently and blindly in 2 different sessions.Three different anatomical groups (A, B and C) were identified based on the 25th and 75th percentiles. A higher percentage of type C was observed among females and a higher percentage of type A among males. A high inter-observer reliability was noted, with a Cronbach's alpha of 0.97 (ICC 0.96-0.98). The intra-observer reliability for observer 1 had a Cronbach's alpha of 0.98.A novel radiological classification of the proximal humerus has been established based on 3 different anatomical types (A, B and C). Further studies are needed to establish whether the novel classification system can be used as an indicator for aseptic loosening of cemented or cementless total shoulder arthroplasty.

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.

Investigation of Morphometric Factors Associated With Adolescent ACL Rupture.

Background: There are no definitive anatomic morphometric risk factors for adolescent anterior cruciate ligament (ACL) injury. Purpose: To compare the parameters used to define the tibial and femoral morphometric structure of the knee between adolescent patients with and without ACL rupture. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Included were magnetic resonance imaging (MRI) scans and radiographs of 115 patients aged 10 to 17 years who were evaluated for ACL rupture at a single institution between February 1, 2019, and January 31, 2022. Images from 115 patients with intact MRI scans were included as controls. We investigated the following imaging parameters: tibial slope (on lateral radiograph), lateral condylar height, tibial sulcus height, medial condylar height, condylar width, intercondylar notch with, intercondylar notch angle, notch index, eminence width, tibial plateau width, eminence width/tibial plateau width, medial/lateral/overall eminence height, medial plateau depth, and 2 different eminence angles. Parameters were compared between groups using the chi-square, Fisher exact, Student t, or Mann-Whitney U test, as appropriate. Receiver operating characteristic analysis was conducted for cutoff values of significant parameters. Results: There were no significant differences in age, sex, or side affected between groups. Only the medial plateau depth was found to be statistically significant between the ACL rupture and ACL intact groups (2.6 vs 2.2 mm; P = .015). A statistically significant cutoff value could not be obtained for the medial plateau depth. Conclusion: Medial plateau depth was found to be significantly greater in adolescent patients with ACL rupture compared with ACL-intact controls.

The effects of different taping methods on patellofemoral alignment, pain and function in individuals with patellofemoral pain: A randomized controlled trial.

BACKGROUND: Athletic taping has long been a physiotherapeutic application in individuals with patellofemoral pain (PFP). However, the therapeutic effects of local and proximal taping have not been fully determined. OBJECTIVE: To evaluate the effects of two different taping techniques applied in addition to exercise on patellofemoral alignment, pain, and function in individuals with PFP. DESIGN: Randomized controlled trial. SETTING: An outpatient hospital clinic. PARTICIPANTS: Individuals with PFP aged 18-50 years (n = 36). INTERVENTIONS: Group 1 underwent only the exercise program. Group 2 underwent the exercise plus McConnell patellar taping (MPT), and Group 3 underwent the exercise plus femoral rotational taping (FRT) (6 weeks). MAIN OUTCOME MEASURES: Bisect offset index (BOI) and patellar tilt angle (PTA) were measured in relaxed and maximum voluntary contractions of the quadriceps muscle (MVCq) using magnetic resonance imaging. Pain intensity was assessed by the Visual Analog Scale for three conditions: at daytime rest, during activity, and at nighttime. Functional level was assessed by the Kujala Patellofemoral Scoring System. RESULTS: Significant improvements in the BOI of Group 2 at rest (p = .015; r = 0.593) and in PTA of Group 3 at MVCq (p = .010; r = 0.613) were found. Improvements in pain under all three conditions were significant within groups (all, p values < .050 and r > 0.5). The change in pain was similar between groups (all, p values > .05). All groups showed significant improvement in functional level (all, p values < .010 and r > 0.5). However, the increase in Group 3 was higher than that in Group 1 (p = .019). CONCLUSION: This study shows that MPT and FRT applications increase functionality and can affect patellofemoral alignment in different ways. In the treatment of PFP, more successful results can be obtained with appropriate taping techniques for the local and proximal region.

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 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.

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.

Periprosthetic joint infection in patients with multiple arthroplasties.

Despite numerous studies focusing on periprosthetic joint infections (PJIs), there are no robust data on the risk factors and timing of metachronous infections. Metachronous PJIs are PJIs that can arise in the same or other artificial joints after a period of time, in patients who have previously had PJI. Between January 2010 and December 2018, 661 patients with multiple joint prostheses in situ were treated for PJI at our institution. Of these, 73 patients (11%) developed a metachronous PJI (periprosthetic infection in patients who have previously had PJI in another joint, after a lag period) after a mean time interval of 49.5 months (SD 30.24; 7 to 82.9). To identify patient-related risk factors for a metachronous PJI, the following parameters were analyzed: sex; age; BMI; and pre-existing comorbidity. Metachronous infections were divided into three groups: Group 1, metachronous infections in ipsilateral joints; Group 2, metachronous infections of the contralateral lower limb; and Group 3, metachronous infections of the lower and upper limb. We identified a total of 73 metachronous PJIs: 32 PJIs in Group 1, 38 in Group 2, and one in Group 3. The rate of metachronous infection was 11% (73 out 661 cases) at a mean of four years following first infection. Diabetes mellitus incidence was found significantly more frequently in the metachronous infection group than in non-metachronous infection group. The rate of infection in Group 1 (21.1%) was significantly higher (p = 0.049) compared to Groups 2 (6.2%) and 3 (3%). The time interval of metachronous infection development was shorter in adjacent joint infections. Concordance between the bacterium of the first PJI and that of the metachronous PJI in Group 1 (21/34) was significantly higher than Group 2 (13/38; p = 0.001). The findings of this study suggest that metachronous PJI occurs in more than one in ten patients with an index PJI. Female patients, diabetic patients, and patients with a polymicrobial index PJI are at significantly higher risk for developing a metachronous PJI. Furthermore, metachronous PJIs are significantly more likely to occur in an adjacent joint (e.g. ipsilateral hip and knee) as opposed to a more remote site (i.e. contralateral or upper vs lower limb). Additionally, adjacent joint PJIs occur significantly earlier and are more likely to be caused by the same bacteria as the index PJI.