An evaluation of the diagnostic performance of the triphasic bone scintigraphy in patients suspected of aseptic total knee arthroplasty loosening.

Background: Total Knee Arthroplasty (TKA) is a widely conducted and successful orthopedic procedure. However, aseptic loosening, a common cause of TKA failure, necessitates revision surgery. Diagnostic accuracy of triphasic bone scintigraphy, a common imaging modality for aseptic loosening detection, remains controversial. This study investigated the diagnostic accuracy of bone scintigraphy when separately evaluated by a nuclear physicist and an orthopedic surgeon, and the interrater reliability between the two. Methods: Patients undergoing knee revision surgery due to suspected aseptic loosening at three medical centers from 2006 to 2023 were included. Relevant demographic, clinical, and procedural data were extracted from the records. The bone scintigraphy results as noted by the nuclear physicist and orthopedic surgeon were used as index test and intraoperative findings of loosening were used as reference tests. Accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were calculated, and kappa's agreement was assessed. Results: Out of 611 revision TKAs, 59 cases were analyzed. The nuclear physicist's evaluation of bone scintigraphy had a sensitivity of 73 %, specificity of 0 %, positive predictive value of 93 %, negative predictive value of 0 %, and diagnostic accuracy of 69 %. The orthopedic surgeon's evaluation showed higher sensitivity, specificity, positive and negative predictive values, and an accuracy of 84 %. Agreement levels were moderate (kappa = 0.46) between the nuclear physicist's and orthopedic surgeons evaluation. Interpretation: The diagnostic accuracy of bone scintigraphy for aseptic loosening is 84 % when evaluated by the orthopedic surgeon compared to 69 % for the nuclear physicist's evaluation. Kappa's agreement between the two was moderate.

Comparison of cost and complications of primary total hip arthroplasty versus oncologic proximal femur replacement.

Aims and objective: Proximal femur replacement (PFR) is most commonly performed after a large resection of the proximal femur to remove tumor and is known to have high complication rates and worse function than a primary total hip replacement (THA). Many surgeons feel that current billing practices fail to adequately differentiate this procedure from a THA. This study aims to examine patients undergoing a primary THA or oncologic PFR and compare the relative economic impact and complication rates between cohorts. Materials & methods: Patient data was queried using a national database, identifying non-pediatric patients who underwent a primary THA or oncologic PFR. Exclusionary criteria were implemented, resulting in two cohorts, each with 380 patients matched in a 1:1 manner controlling for age, gender, and Charlson Comorbidity Index. Utilizing 2022 billing data, oncologic PFRs generated an average of 41.03 RVUs and primary THAs generated 19.60 RVUs. Total hospital cost was used to generate a cost:RVU ratio for each cohort. Key systemic and joint complication rates were additionally compared between cohorts. Results: The oncologic PFR cohort had significantly higher 90-day rates of anemia, deep vein thrombosis, and prosthetic dislocation compared to the primary THA cohort. The 90-day median hospital cost for oncologic PFR was $28,562.21 with a cost:RVU ratio of $696:1. The corresponding median hospital cost for primary THA was $9667.72, with a cost:RVU ratio of $493:1. Conclusion: Hospitals incur more cost per RVU for an oncologic PFR than a primary THA. Relative to primary THA, reimbursement for oncologic PFR is under-evaluated.

Comparison of outcomes after total hip arthroplasty in hip fracture versus elective cases in patients over 60 years of age.

Background: Total hip arthroplasty (THA) allows for the replacement of impaired parts of the hip joint with artificial ones. This study aimed to compare the differences in preoperative patient profiles, postoperative complications, and clinical outcomes of two patient groups: those who underwent THA for fractures and those who underwent THA electively for diseases such as osteoarthritis (OA) and avascular necrosis (AVN). Methods: We retrospectively analyzed the data of patients who underwent THA between March 2012 and December 2021. Of 232 patients, 173 patients who met the exclusion and inclusion criteria were included. Patients were divided into two groups (Group 1: 113 patients diagnosed with OA or AVN; Group 2: 60 patients diagnosed with hip fracture). Pre- and postoperative Visual Analogue Scale (VAS), Koval scores, and postoperative modified Harris Hip Score (mHHS) were used to assess clinical outcomes. Demographic data and postoperative complications of the two groups were compared. After surgery, a rehabilitation protocol was initiated. Results: Patients in Group 2 (fracture) had more preoperative comorbidities than those in Group 1 (elective). Follow-up months are 26.22 ± 19.78 (Group 1), and 27.42 ± 17.02 (Group 2) respectively (P > 0.05). There were no statistical differences in the prevalence of postoperative complications between two groups (P > 0.05). Compared with Group 1(elective), Group 2(fracture) showed lower VAS (P < 0.01) at last follow-up, and no difference in Koval score (P = 0.77) and mHHS (P = 0.96) at last follow-up. Conclusion: Considering the characteristics of the two groups and their perioperative multidisciplinary care, THA for hip fractures can provide good clinical results compared to those with elective THA.

Quadriceps angle as an outcome measure for structural integrity following total knee arthroplasty in individuals with severe knee osteoarthritis.

Purpose: Total knee arthroplasty (TKA) is routinely performed for pain relief and to improve performance of the knee in individuals with severe knee osteoarthritis (OA). The quadriceps angle (Q-angle) is a key component of knee joint stability. However, there is a dearth of literature evaluating Q-angle as an outcome measure after TKA in individuals with severe knee OA. Objectives: The objective of the study was to assess the Q-angle as an outcome measure before and after TKA and to find the correlation of Q-angle with pain, quadriceps strength, and knee flexion range of motion (ROM) after TKA in individuals with severe knee OA. Methods: The Q-angles of 34 individuals (male: female = 17:17) were measured using standardized procedures. Pain, quadriceps strength, and knee flexion ROM were measured. The measurements were taken preoperatively (one day before surgery), and postoperatively at the sixth week and third month after TKA. Results: The mean Q-angle was 19.17° (SD = 1.92°) before TKA, 16.06° (SD = 1.87°) at the sixth week and 13.43° (SD = 1.77°) at the third month after TKA. Significant linear correlations were noted between the Q-angle and pain, quadriceps strength, and knee flexion ROM following TKA. Conclusion: The Q-angle was measured before and after TKA using a standardized clinical goniometric method. Understanding the Q-angle before and after TKA and its relationship with various clinical and functional variables is imperative in clinical practice for orthopedic surgeons and rehabilitation professionals.

Geographical incidence of testosterone supplementation in total hip and knee arthroplasty.

Introduction: Prescription testosterone usage in the United States declined after 2013 following reports of its association with myocardial infarction and stroke. However, more recently there has been a documented increase in testosterone prescriptions. Recently, testosterone levels have also been hypothesized to increase infection risk in patients undergoing elective shoulder arthroplasty. Furthermore, testosterone may increase the risk of venous thromboembolism. These complications are perioperative concerns for total hip and knee arthroplasties (THA/TKA). Therefore, the purpose of our study is to identify trends in the incidence of testosterone prescriptions in patients who underwent THA/TKA with respect to geographical population data. Methods: We retrospectively reviewed 40,711 primary THAs and 50,893 primary TKAs performed in males between 1/1/2016 and 12/31/2021 using a commercial claims database. Records were reviewed for demographics, geographical location, and supplemental testosterone prescriptions within 1 year prior to surgery. Patient Metropolitan Statistical Area (MSA) was assessed with respect to United States Census Population Data. Results: We identified 91,604 males who underwent primary THA (n = 40,711) or TKA (n = 50,893). For THA/TKA, patients who were younger had a higher likelihood of having a supplemental testosterone prescription (OR = 0.99, 95 % CI [0.99-1.00], p < 0.001). TKA patients (2,507, 4.9 %) had a higher rate of testosterone prescriptions than THA patients overall (1,413, 3.4 %), (OR = 1.44 95 % CI [1.35, 1.54], p < 0.001) as well as within each year.For THA and TKA patients, patients in the Midwest (OR = 1.61, p < 0.001), South (OR = 3.04, p < 0.001), and West (OR = 2.28, p < 0.001) regions all had higher testosterone prescription rates than the Northeast. Patients living in a city (MSA population ≥200,000) were more likely to be prescribed testosterone (OR = 1.20, p = 0.002). Conclusion: Surgeons conducting TKA/THA should be aware that younger patients, those in higher population areas, and those in the Midwest, South, and West regions are more likely to be prescribed testosterone than those in the Northeast.

Feasibility of prehabilitation for patients awaiting total knee arthroplasty; a pilot study.

Objective: To examine the feasibility of conducting a preoperative home-based prehabilitation program for total knee arthroplasty patients at risk for delayed in-hospital recovery, and to explore the pre- and postoperative impact of this program. Design: A retrospective cohort study with matched controls, enabling subgroup analyses. Setting: Home-based. Subjects: Patients awaiting primary unilateral total knee arthroplasty between 2019 and 2020, were compared with matched historic cases from 2016 to 2017. Matching criteria were scoring ≤17 points on the De Morton Mobility Index and >12.5 s on the timed-up-and-go test. Intervention: Supervised home-based prehabilitation program versus no prehabilitation. Outcomes: Feasibility, determined by recruitment rate, adherence, and safety of the program. Preoperative impact, assessed for the intervention group by differences in mean values for aerobic capacity, muscle strength and functional mobility between the first and last sessions. Postoperative impact was defined as the time needed to achieve in-hospital independence of physical function and was measured by the differences in mean values between the intervention and control groups. Results: Recruitment rate was 71 %; adherence and drop-out rates were 88 % and 12 % respectively. No adverse events were reported. Preoperatively, the intervention group showed significant improvements in aerobic capacity on the 2-min walking test (84.29 m-98.06 m; p = 0.007) and 2-min step test (40.35 steps to 52.95 steps; p = 0.014), muscle strength on the 30 s chair stand test (7.3 stands to 10.1 stands; p = 0.002), and functional mobility as seen in the timed-up-and-go-test (19.52 s-15.85 s; p = 0.031). Postoperatively, the intervention group achieved in-hospital independence of physical function earlier (mean rank 16.11) than the control group (mean rank 24.89; p=<0.01). Conclusions: It is feasible to conduct a prehabilitation program 4-6 weeks preoperatively, for high-risk patients awaiting total knee arthroplasty. Additionally, the program appears to have a positive impact on physical fitness both pre- and postoperatively.

Mitigating calcar fracture risk with automated impaction during total hip arthroplasty.

Background: Automated broaching has recently been introduced for total hip arthroplasty (THA), with the goal of improving surgical efficiency and reducing surgeon workload. While studies have suggested that this technique may improve femoral sizing and alignment, little has been published regarding its safety, particularly with regard to calcar fractures. The purpose of our study was to evaluate the risk of calcar fracture during automated broaching, and to determine if this risk can be mitigated. Methods: We queried our prospective institutional database and identified 1596 unilateral THAs performed by the senior author using automated impaction between 2019 and 2023. We identified the incidence of calcar fracture with automated impaction, and whether the fracture occurred during broaching or stem insertion. We additionally determined calcar fracture incidence within two consecutive subgroups of patients using different stem insertion techniques; subgroup (1): automated broaching with automated stem insertion for all patients; versus subgroup (2): automated broaching with automated stem insertion ONLY if a cushion of cancellous bone separated the broach from the calcar, otherwise the stem was placed manually. Continuous and categorical variables were analyzed with Student's t-test and Fisher's exact test, respectively. Results: Seventeen calcar fractures occurred intraoperatively (1.1 %). Only two fractures occurred during automated broaching (0.1 %), while fifteen occurred during final stem impaction (0.9 %) (p = 0.007). Four calcar fractures (1.4 %) occurred in subgroup 1, compared to two in subgroup 2 (0.6 %) (p = 0.28). Conclusions: Our study found a calcar fracture incidence of 1.1 % using automated impaction, consistent with historically reported rates of 0.4-3.7 %. We found that calcar fractures are more likely to occur during stem insertion than during femoral broaching. We recommend that if any part of the final broach is in direct contact with the calcar, the final stem should be impacted manually to minimize fracture risk.

Use of computed tomography for shoulder arthroplasty: A systematic review.

Introduction: The prevalence of total shoulder arthroplasties is on the rise annually. Improvements in implant quality, construct stability, and surgical techniques have notably enhanced post-operative results, prompting an expansion of indications for shoulder arthroplasty. Despite its high success rate, opportunities for enhancement remain, especially in preoperative planning and intraoperative execution. Advanced imaging technologies offer significant potential in optimizing implant placement, thus improving the longevity of the procedure. To our knowledge, a comprehensive review examining the impact of advanced imaging on shoulder arthroplasty has yet to be conducted. This systematic review aims to investigate the benefits of advanced imaging technologies in this context, focusing on their application in preoperative planning, osteoarthritis assessment, intraoperative adjustments, patient-specific instrumentation, and navigational aids. Methods: This review utilized a comprehensive search of PubMed to identify relevant studies published from 2000 to 2024, focusing on the application of various imaging techniques in shoulder arthroplasty. The search was conducted by two authors and centered on plain radiography, CT scans, and MRI. The selection criteria included availability of full-text articles, English language, direct comparison of imaging techniques, and a focus on patient outcomes, including discussions on broader applications such as intraoperative navigation and patient-specific instrumentation development. Results: Enhanced imaging techniques, particularly CT scans and MRIs, have been shown to significantly improve outcomes in shoulder arthroplasty. While plain radiographs remain standard, CT scans provide superior bony detail, crucial for evaluating glenoid wear and determining augmentation needs. Preoperative CT imaging has been demonstrated to enhance implant placement accuracy. Moreover, intraoperative technologies based on CT imaging, such as patient-specific instrumentation and navigation systems, contribute to better surgical results. Conclusion: The benefits of CT imaging in shoulder arthroplasty significantly outweigh the associated costs. Current literature strongly supports the adoption of CT imaging in these procedures, particularly when used alongside modern operative technologies.

Short-term outcomes with routine use of size ≥40 femoral heads in THA: A retrospective cohort study.

Background: Using larger femoral heads during total hip arthroplasty (THA) may result in a more stable hip. Greater volumetric wear and frictional torque, however, may result in increased postoperative complications. The purpose of this study was to compare outcomes of patients with femoral head size ≥40 mm compared to those with femoral head size <40 mm. Materials and methods: A retrospective chart review of 504 THAs performed by a single surgeon at a single institution from 2009 to 2016 was conducted. Following exclusions, 131 THAs were identified with femoral heads ≥40 mm and 348 THAs were identified with femoral heads <40 mm. In addition to demographic data, all postoperative complications were recorded. Plain radiographs were used to rule out/in periprosthetic osteolysis and/or acetabular loosening. Chi-square tests and Student's t-tests were used to compare categorical and continuous variables, respectively. Results: Mean follow-up period for the entire cohort was 5.5 years. Complications with ≥40 mm femoral heads included 1 superficial infection and 1 deep periprosthetic joint infection (PJI). There were no cases of dislocation, osteolysis, acetabular loosening, or trunnionosis. In contrast, complications with <40 mm femoral heads included 9 dislocations and 7 PJIs. Conclusion: The routine use of large femoral heads (≥40-mm) during THA appears to be a safe option for patients at short-term clinical follow-up. Notably, 0 patients had a clinical course complicated by dislocation, osteolysis, acetabular loosening, or trunnionosis. Level of evidence: Level III Retrospective Cohort Study.

Patellar resurfacing in contemporary total knee arthroplasty: Frequency of complications in a matched cohort.

Introduction: Optimum patient selection and outcomes following patellar resurfacing are ongoing debates amongst the arthroplasty community. This study compared the outcomes of patients who had a total knee arthroplasty (TKA) with patellar resurfacing to those left with their native patella. Methods: A retrospective review of 1941 TKAs performed between 2016 and 2020 was conducted. 41 TKAs without patellar resurfacing and with 2-years of minimum follow-up were identified. Of these, 38 TKAs were matched on age (exact), sex (exact), and body mass index (±10) to 38 TKAs that had patellar resurfacing. The indications for patella resurfacing were subjective based upon the surgeon preference and assessment of cartilage quality. Paired t-tests and chi-square tests were used for analysis. Results: There was 1 major patellofemoral complication in both the resurfaced group (patellar fracture) and the non-resurfaced group (patellar tendon tear), requiring nonoperative management and revision surgery, respectively. However, in the non-resurfaced group there were 4 cases of subjective patellofemoral pain compared to none in the resurfaced group (p = 0.37). Additionally, 3 non-resurfaced patients required manipulation under anesthesia (MUA) compared to none in the resurfaced group (p = 0.44). Discussion: There was no difference in the frequency of major patella-specific complications between the groups. However, there was a non-statistically significant trend towards increased patellofemoral pain and MUA in the non-resurfaced group. Based on this study both methods of treatment remain viable options, but the trend towards increased pain and stiffness should continue to be closely evaluated.

Sharma's risk assessment score as a decision making tool to decide between total hip arthroplasty or hemiarthroplasty as a treatment option for elderly patients with fracture neck of femur. A prospective observational study.

Purpose: The decision to do a total hip arthroplasty (THA) or a hemiarthroplasty (HA) in an elderly with a fracture neck of femur (FNOF) is commonly based upon the surgeon's preference, pre-anesthetic fitness, hospital setup, and intensive care backup. The author devised a Sharma's risk assessment score (SRAS), based upon all the common factors that affect the surgical outcomes following FNOF in the elderly, to help orthopedic surgeons decide between THA or HA as a treatment for FNOF. Material & methods: It was a prospective observational study conducted in a tertiary-level institute. SRAS is based upon 10 parameters with each parameter having a max score of 4 and a minimum score of 1. So the maximum score a patient can score is 40 and the minimum a patient can score is 10. It was hypothesized that a patient with FNOF with a preop SRAS score >20 if subjected to a (HA) and a patient with a preop SRAS score ≤ 20 if subjected to a (THA) would have better outcomes and low complication rates. Out of Eighty-eight patients with FNOF, 7 were lost to follow-up. The remaining 81 patients with FNOF were prospectively followed between May 2018 and May 2022 and segregated into two groups THA (n = 47) and HA(n = 34) based on the SRAS. Results: The average length of follow-up was 2.6 years (6 months-4 years). The average SRAS was an average 25.7(21-32) in the HA group and 16.2 (11-20) in the THA group. Complications were seen in 12.7 % of the THA group and 17.6 % of the HA group. We had a 2.1 % 90-day mortality in the THA group and a 2.9 % 90-day mortality in the HA group. One year mortality in THA was 2.1 % and it was increased to 5.8 % in the HA group. Conclusion: SRAS is a useful decision-making tool that would guide surgeons to decide between THA or HA as a treatment option for elderly FNOF and would help minimize post-operative complications and reduce mortality. Level 3 study: Prospective observational study.

Preserving medial iliofemoral ligament avoids excessive leg lengthening in total hip arthroplasty using anterolateral-supine approach.

Background: In this study, we compared postoperative leg length discrepancy (LLD) after total hip arthroplasty using the anterolateral-supine approach (ALSA THA) with or without medial iliofemoral ligament (mILFL) preservation and examined the effect of the remaining mILFL on postoperative LLD. Methods: This was a single-center, retrospective case control study. Unilateral primary THA with a preoperative LLD <15 mm, in which the contralateral side was intact, was included. After ALSA THA, we compared the absolute values of postoperative LLDs and examined the ratio of postoperative LLD >5 mm with and without mILFL preservation. Demographic data, clinical scores, and operative data were collected. Statistical significance was set at p < 0.05. Results: We included 341 hips (preservation group: 283 hips; resection group: 58 hips). The mean (range) absolute values of the postoperative LLDs were 2.3 (0-15.9) mm and 3.4 (0-14.8) mm, respectively. There was no significant difference between the two groups (p = 0.36). The proportion of postoperative LLD >5 mm differed significantly between the groups (4.4 % and 20.0 %, respectively; p < 0.01). Multiple logistic regression analysis showed that resection of the mILFL was the only significant factor that caused excessive leg lengthening (odds ratio, 5.28; 95 % confidence interval, 2.12-13.10, p < 0.01). Significant differences were reported in surgical time (81 (38-132) and 96 (54-157), respectively; p < 0.01) and intraoperative blood loss (297 (50-1170) and 388 (100-1150), respectively; p < 0.01). However, no significant differences in clinical scores, dislocation (including instability), or reoperation rates were observed between the two groups. Conclusion: In patients with a preoperative LLD <15 mm, preserving the mILFL in ALSA THA avoids excessive leg lengthening and may lead to shorter LLD without any difficulties.

Postoperative laboratory testing in the era of outpatient total joint arthroplasty: Targeted patient selection and associated cost savings.

Background: With the advent of outpatient total joint arthroplasty (TJA), the days of routinely drawing postoperative labs (complete blood counts [CBCs] and metabolic panels [CMPs/BMPs]) to monitor for complications are behind us. However, there does exist a subset of at-risk patients that may benefit from diligent postoperative monitoring, though the circumstances under which labs should be ordered remains unclear and subject to surgeon discretion. A systematic review of the literature was therefore conducted to evaluate the utility of postoperative laboratory testing, approaches to targeted patient selection and associated cost-savings. Methods: The PubMed, MEDLINE, EBSCOhost, and Google Scholar electronic databases were searched on August 17, 2023, to identify all studies published since January 1, 2000, that evaluated the role of postoperative lab testing in TJA. (PROSPERO study protocol registration: CRD42023437334). Articles were included if a full-text English manuscript was available and the study assessed the utility of routine postoperative labs in TJA. 19 studies were included comprising 34,166 procedures. The mean Methodological index for Nonrandomized Studies score was 18.2 ± 1.5. Results: Abnormal postoperative lab results were common and infrequently required clinical intervention. Among several identified risk factors for patients that may benefit from postoperative laboratory monitoring, preoperative lab values proved excellent discriminators of transfusion requirement and metabolite-associated intervention. Selective testing demonstrated the ability to generate substantial cost-savings. Conclusion: Routine postoperative laboratory testing offers little clinical utility and produces unnecessary expenditures. Preoperative lab values offer the greatest predictive utility for postoperative transfusion requirement and metabolite-associated clinical intervention, with a preoperative hemoglobin threshold of 111.5 g/L offering an area under the curve (AUC) of 0.93 for predicting postoperative transfusion. Further investigations are needed for metabolic panel predictive models and should incorporate preoperative lab values. The refinement of such models can enable targeted patient selection to avoid unnecessary labs and generate substantial cost savings without compromising patient safety.

Greater readmission rates after total hip arthroplasty with discharge to a facility vs. home: A propensity score matched analysis.

Purpose: Provided that total hip arthroplasties (THA) are some of the most common surgical procedures performed, there is a necessity to understand all factors that contribute to risks of adverse outcomes postoperatively and to find solutions to avoid these events with preventive measures. This retrospective cohort study sought to assess differences in (1) postoperative complication rates, (2) readmission rates and reasons, and (3) demographic variables that contribute to readmissions based on discharge destination within the first 30 days after a THA. Methods: Patients undergoing THA (27130) between 2015 and 2020 were extracted from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database based on procedural codes. Propensity score matching was then employed to reduce selection bias, and Chi-square tests and one-way analysis of variance (ANOVA) were performed. Multivariable analysis was then used to look for other factors associated with readmission risk. Results: 219,960 patients were identified with 189,841 discharged to home, 19,355 to a skilled nursing facility (SNF), and 10,764 to a rehabilitation facility. The rehabilitation and SNF cohorts both had greater rates of readmission (4.56 % home vs. 6.88 % SNF vs. 6.90 % rehabilitation, P<0.001) and any adverse event (AAE, 9.02 % vs. 18 % vs. 21.3 %, P<0.001) after matching. Older age, longer operative time, American Society of Anesthesiologists (ASA) classification four, chronic obstructive pulmonary disease (COPD), bleeding disorders, steroid use, and smoking were associated with an increased risk of readmission after THA. Conclusion: Overall, THAs were shown to have low postoperative complications and readmissions in all patient populations despite differences in discharge destination which continues to demonstrate the safety and validity of this often elective procedure. However, the statistically significant risk of complications and readmissions in addition to the higher costs associated should be accounted for when considering patient discharges to a non-home facility.

A finite element analysis of patellofemoral joint biomechanics: Exploring potential causes of postoperative anterior knee pain following unicompartmental knee arthroplasty.

Purpose: Anterior knee pain is a common complication following unicompartmental knee arthroplasty (UKA). This study aimed to elucidate the mechanism of anterior knee pain after UKA by examining the biomechanical characteristics of the patellofemoral joint. Methods: This study employs the finite element analysis method. A healthy model of the right lower limb was created using CT scans of an intact right lower limb from a healthy woman. Based on this model, a preoperative pathological model was generated by removing the meniscus and part of the articular cartilage. The UKA prosthesis was then applied to this model with five different bearing thicknesses: 5 mm, 7 mm, 10 mm, 11 mm, and 13 mm. To simulate various degrees of knee joint flexion, the femur was rotated relative to the knee joint's rotational axis, producing lower limb models at flexion angles of 0°, 30°, 60°, 90°, and 120°. We applied a constant force from the center of the femoral head to the center of the ankle joint to simulate lower limb loading during squatting. The simulations were conducted using Ansys 17.0. Results: Both overstuffing and understuffing increased the peak stress on the patellar cartilage, with overstuffing having a more pronounced effect. Compared to healthy and balanced models, overstuffed and understuffed models exhibited abnormal stress distribution and stress concentration in the patellar cartilage during knee flexion. Conclusion: Overstuffing and understuffing lead to residual varus or valgus deformities after UKA, causing mechanical abnormalities in the patellofemoral joint. These abnormalities, characterized by irregular stress distribution and excessive stress, result in cartilage damage, exacerbate wear in the patellofemoral joint and consequently lead to the occurrence of anterior knee pain.

Modified notching classification in inverted-bearing and conventional-bearing reverse total shoulder arthroplasty.

BACKGROUND: Scapular notching is a common complication of reverse total shoulder arthroplasty (RTSA). Although the notching rate has reduced significantly thanks to modifications to the surgical technique and humeral and glenoid components, uncontrollable polyethylene (PE)-induced osteolysis can still occur. In contrast to conventional-bearing (CB-RTSA), inverted-bearing RTSA (IB-RTSA) systems, with PE glenospheres and metal or ceramic humeral liners, avoid PE abrasion through scapulohumeral contact. If present, the resulting notch has a different size and configuration than with CB-RTSA. Thus, a modified notching classification seems reasonable. Even in CB-RTSA, the early stages of notching show a different configuration than implied by the established Nerot-Sirveaux classification; therefore, a modification of the classification system is recommended. METHODS: In a prospective multicentre study, 250 cases underwent IB-RTSA. Of these, 39 died, and 28 were lost to follow-up for other reasons, leaving 183 shoulders for the final follow-up examination at a mean of 120.7 months (range 84.1-172.4 months). In the CB-RTSA group, we retrospectively evaluated radiographs of 59 consecutive patients with a follow-up ranging from 2 to 7 years. We analysed the appearance, evolution over time, and location of bone loss on the scapular neck according to the modified Nerot-Sirveaux classification. RESULTS: In IB-RTSA, notching resulted in a new morphological configuration: In contrast to the Nerot-Sirveaux classification, notching began far from the baseplate as an impression or abrasion of the humeral component in the inferior scapular rim. Due to simultaneous mechanical ablation, the defect gradually enlarged, but usually did not contact the baseplate or extend beyond the inferior peg. No signs of PE-induced osteolysis were found. The notching rate reached 19% after 2 years and approached 36% after 10 years. Most shoulders had grade 0 notching (64%), followed by grade 1 (29%); extensive erosion (grade 4) was not observed. In the CB-RTSA group, a small bony impression or erosion without signs of PE-induced osteolysis was observed medial to the scapular neck, without contact with the metaglene in the early phase, which was similar to the impression of the humeral component in IB-RTSA. The notching rate was 86% for CB-RTSA. CONCLUSIONS: A new classification was developed for IB-RTSA, which corresponds to the pathophysiological processes and is compatible with the existing Nerot-Sirveaux classification. Bone erosion in CB-RTSA is not adequately represented by the established classification in the early stages. For this reason, a supplement to the existing classification is presented. LEVEL OF EVIDENCE: Level 4, Case Series, Treatment Study.

Surgical decisions on implant-related parameters can enhance knowledge transfer for glenoid bone grafting in primary reverse shoulder arthroplasty: a scoping review of heterogeneity sources.

Purpose: The purpose of the present scoping review is to identify sources of heterogeneity in reporting domains that have the potential to improve surgical decision-making in reverse shoulder arthroplasty associated with glenoid bone grafting. Methods: A scoping review was conducted according to the JBI and PRISMA ScR guidelines. Articles covering glenoid bone grafting at the time of reverse shoulder replacement, published between 2012 and 2022 in MEDLINE, Scopus, Epistemonikos, Web of Science, and Cochrane Database of Systematic Reviews, were searched. Reporting of core outcome measures, as well as prosthesis-related variables, rehabilitation protocols, radiographic evaluation methods, and bone graft incorporation assessments, were collected. Results: For the final analysis, a total of 14 articles were considered. There were 649 operated shoulders with a mean patient age of 72 years, ranging from 48 to 85 years. Analysis of preoperative ranges of motion and patient-reported outcome measures revealed increased heterogeneity in patient selection between studies. Reporting of implant-related parameters was the most inconsistent. Rehabilitation protocols were scarcely reported. Assessment of graft incorporation and radiographic evaluation of choice revealed that there is no consistent method or measurement and the clinical relevance of radiolucent lines at the graft-glenoid bone interface is unclear. Conclusion: Addressing implant-related reporting gaps has the highest potential to improve surgical decision-making and provide orthopedic surgeons with a more comprehensive understanding of published results on glenoid bone grafting at the time of primary reverse shoulder arthroplasty.

Efficacy and safety of vancomycin for local application in the prevention of surgical site infection after joint arthroplasty: a systematic review and meta-analysis.

Purpose: The aim of this systematic review and meta-analysis is to explore the effect of topical vancomycin powder (VP) in surgical site infection (SSI) prevention and adverse events after joint arthroplasty and to provide a specific theoretical basis for clinical treatment. Methods: The review process was conducted according to the PRISMA guidelines. Two independent researchers meticulously screened the literature based on predefined inclusion and exclusion criteria, evaluated the quality of the selected studies, and extracted relevant data. Data analysis was conducted using RevMan 5.4 software. Results: This meta-analysis included 24 studies encompassing a total of 34 811 patients. The pooled analysis showed that the topical administration of VP significantly reduced the incidence of SSI. Subgroup analyses by doses, type of joint (hip and knee), and type of surgery (primary and revision) confirmed that vancomycin consistently lowered SSI rates. Moreover, the incidence of SSI caused by gram-negative germs and gram-positive germs decreased following the use of VP, although the reduction was not significant for infections caused by MRSA. However, the use of VP was associated with a significant increase in sterile complications at the incision site and delayed incision healing. Conclusion: The topical application of VP is effective in reducing the incidence of infections following joint arthroplasty. Despite an increased risk of complications such as delayed healing of incisions, the pros and cons should be weighed in clinical decision-making. However, it should not be discarded due to side effects.

Big data analysis reveals significant increases in complications, costs, and hospital stay in revision total knee arthroplasty compared to primary TKA.

INTRODUCTION: Despite significant advancements in total knee arthroplasty (TKA), some patients require revision surgery (R-TKA) due to complications such as infection, mechanical loosening, instability, periprosthetic fractures, and persistent pain. This study aimed to explore the specific causes leading to R-TKA, associated complications, including infection, mechanical failure, and wound issues, as well as costs, mortality rates, and hospital length of stay (LOS) using data from a large national database. METHODS: Data from the nationwide inpatient sample (NIS), the largest publicly available all-payer inpatient care database in the United States were analysed from 1 January 2016 to 31 December 2019. The study included 44,649 R-TKA cases, corresponding to 223,240 patients, with exclusions for nonelective admissions. Various statistical analyses were used to assess clinical outcomes, including in-hospital mortality, postoperative complications, LOS, and hospitalization costs. RESULTS: Among 2,636,880 TKA patients, 8.4% underwent R-TKA. R-TKA patients had higher rates of chronic conditions, including mental disorders (36.4%) and renal disease (9.9%). Additionally, these patients often experienced instability, necessitating revision surgery. Infection (22.3%) was the primary reason for R-TKA, followed by mechanical loosening (22.9%) and instability. Compared to primary TKA patients, R-TKA patients exhibited higher in-hospital mortality (0.085% vs. 0.025%), longer LOS (3.1 vs. 2.28 days), and higher total charges ($97,815 vs. $62,188). Postoperative complications, including blood transfusion (4.6% vs. 1.3%), acute kidney injury (4.4% vs. 1.8%), venous thromboembolism (0.55% vs. 0.29%), infection, and wound problems, were significantly higher in R-TKA patients. CONCLUSIONS: This study provides detailed insights into t LOS, costs, and complications associated with specific etiologies of revision TKA. Our findings emphasize the need for targeted preoperative optimization and patient education. This approach can help reduce the incidence and burden of R-TKA, improve patient care, optimize resource allocation, and potentially decrease the overall rates of complications in revision surgeries. LEVEL OF EVIDENCE: Level III.