Robotic-assisted Total Knee Arthroplasty Reduces Radiographic Outliers for Low-volume Total Knee Arthroplasty Surgeons.

Background: Most studies evaluating robotic-assisted total knee arthroplasty (RA TKA) analyzed the advantages offered to high-volume surgeons. This study aims to determine if RA TKA improves radiographic or clinical outcomes for low-volume, non-arthroplasty-trained surgeons. Methods: Radiographic and early clinical outcomes of 19 RA TKAs and 41 conventional TKAs, all performed by a single, non-arthroplasty-trained orthopaedic surgeon, were compared. Radiographic outliers were based on surgeon targets and defined as tibial posterior slope outside of 0°-5°, tibial tray varus outside of 0°-3°, and the presence of notching. Clinical outcomes included inpatient narcotic usage, length of stay, range of motion, and Patient-Reported Outcome Measurement Information System scores. Results: There was a significant decrease in tibial slope outliers (RA TKA 0% vs non-RA TKA 22%, P = .024) and notching incidence (RA TKA 0% vs non-RA TKA 19.5%, P = .044) in the RA group. Tibial tray varus/valgus outliers trended lower in the RA TKA group (10.0% vs 26.8%, P = .189). Length of stay was significantly shorter in RA patients (48.0 hours [standard deviation: 25.5] vs 67.7 hours [34.3], P = .038). RA patients trended toward lower in postoperative inpatient total mean morphine equivalents usage (79.9 [89.2] vs 140.1 [169.3], P = .142) and inpatient mean morphine equivalents usage per day (30.36 [26.9] vs 45.6 [36.7], P = .105). There was no significant difference in Patient-Reported Outcome Measurement Information System scores or range of motion at first and second postoperative follow-up within 3 months. Conclusions: RA TKA reduced the incidence of radiographic outliers when compared to conventional TKA for a low-volume arthroplasty surgeon.

Preoperative Depression Is Associated With Increased Short-term Complications But Equivalent Long-term Outcomes in Total Knee Arthroplasty.

Concomitant depression negatively impacts outcomes following total knee arthroplasty (TKA). Patient-Reported Outcomes Measurement Information System (PROMIS) surveys are validated measures that quantify depression, pain, and physical function. We hypothesized that higher preoperative PROMIS-depression scores would be associated with inferior outcomes following TKA. A total of 258 patients underwent primary TKA at a tertiary academic center between June 2018 and August 2020. PROMIS scores were collected preoperatively and at 6 weeks, 3 months, 1 year, and 2 years postoperatively. Patients with preoperative PROMIS depression scores of 55 or greater were considered PROMIS depressed (PD) and patients with scores less than 55 were considered not PROMIS depressed (ND). The primary outcomes were changes in PROMIS scores. Secondary outcomes included total and daily mean morphine milligram equivalents (MME) received during admission as well as 90-day hospital readmission and 2-year all-cause revision rates. There were 66 (25.58%) patients in the PD group and 192 (74.42%) in the ND group. Patients in the PD group had improved depression scores at all follow-up intervals (P<.001) and decreased pain scores at 1 year (P=.016). Both groups experienced similar changes in function scores at each follow-up interval. Patients in the PD group had higher total (P=.176) and daily (P=.433) mean MME use while admitted. Ninety-day hospital readmissions were higher in the PD group (P=.002). There were no differences in 2-year revision rates (P=.648). Preoperative PROMIS-depression scores of 55 or greater do not negatively impact postoperative function, depression, or pain, and patients with these scores have greater improvement in depression and pain at certain intervals. Patients in the PD group had higher readmission rates. [Orthopedics. 2024;47(1):40-45.].

The role of relaxin in anterior cruciate ligament injuries: a systematic review.

OBJECTIVE: Anterior cruciate ligament (ACL) tears are exceedingly common among the athletic population and are seen with higher incidence in females. Observational studies have noted peak ACL tear rates in the luteal phase of the menstrual cycle, a time in which the hormone relaxin peaks in serum concentration. METHODS: A systematic review of the literature was performed. Inclusion criteria specified all prospective and retrospective studies which included the role of relaxin in the pathogenesis of ACL tears. RESULTS: Six studies met inclusion criteria yielding 189 subjects from clinical studies and 51 in vitro samples. Included studies found that ACL samples exhibit selective relaxin binding. When pre-treated with estrogen prior to relaxin exposure, female ACL tissue samples exhibit increased expression of collagen degrading receptors. CONCLUSION: Relaxin displays binding specificity to the female ACL and increased serum concentrations are correlated with increased ACL tear rates in female athletes. Further research is needed in this area. LEVEL OF EVIDENCE: V.

Revision total knee arthroplasty for arthrofibrosis improves range of motion.

PURPOSE: Arthrofibrosis after primary total knee arthroplasty (TKA) is a significant contributor to patient dissatisfaction. While treatment algorithms involve early physical therapy and manipulation under anaesthesia (MUA), some patients ultimately require revision TKA. It is unclear whether revision TKA can consistently improve these patient's range of motion (ROM). The purpose of this study was to evaluate ROM when revision TKA was performed for arthrofibrosis. METHODS: A retrospective study of 42 TKA's diagnosed with arthrofibrosis from 2013 to 2019 at a single institution with a minimum 2-year follow-up was performed. The primary outcome was ROM (flexion, extension, and total arc of motion) before and after revision TKA, and secondary outcomes included patient reported outcomes information system (PROMIS) scores. Categorical data were compared using chi-squared analysis, and paired samples t tests were performed to compare ROM at three different times: pre-primary TKA, pre-revision TKA, and post-revision TKA. A multivariable linear regression analysis was performed to assess for effect modification on total ROM. RESULTS: The patient's pre-revision mean flexion was 85.6 degrees, and mean extension was 10.1 degrees. At the time of the revision, the mean age of the cohort was 64.7 years, the average body mass index (BMI) was 29.8, and 62% were female. At a mean follow-up of 4.5 years, revision TKA significantly improved terminal flexion by 18.4 degrees (p < 0.001), terminal extension by 6.8 degrees (p = 0.007), and total arc of motion by 25.2 degrees (p < 0.001). The final ROM after revision TKA was not significantly different from the patient's pre-primary TKA ROM (p = 0.759). PROMIS physical function, depression, and pain interference scores were 39 (SD = 7.72), 49 (SD = 8.39), and 62 (SD = 7.25), respectively. CONCLUSION: Revision TKA for arthrofibrosis significantly improved ROM at a mean follow-up of 4.5 years with over 25 degrees of improvement in the total arc of motion, resulting in final ROM similar to pre-primary TKA ROM. PROMIS physical function and pain scores showed moderate dysfunction, while depression scores were within normal limits. While physical therapy and MUA remain the gold standard for the early treatment of stiffness after TKA, revision TKA can improve ROM. LEVEL OF EVIDENCE: IV.

Return to Recreational Sport Following Lumbar Fusion.

STUDY DESIGN: This was a retrospective questionnaire study at a single academic medical center. OBJECTIVE: The objective of this study was to obtain information on rates of return to sport following lumbar fusion as well as sport-specific effects to improve evidence-based preoperative patient counseling. SUMMARY OF BACKGROUND DATA: Lumbar spinal fusion is one of the fastest-growing surgical procedures, with the majority being in patients aged 60 years and older. Remaining active is an important consideration for elderly patients undergoing lumbar spinal fusion. Golf, swimming, and biking are common forms of recreational exercise for an older population in whom lumbar fusion is often performed. There is a lack of data in the current literature regarding rates of return to recreational sporting activities following elective lumbar fusion. METHODS: Following Institutional Review Board approval, all patients undergoing lumbar fusion at a single institution from 2012 to 2016 were screened and included in this study. A minimum of 1-year postoperative follow-up was required. A total of 117 patients were identified undergoing single-level or multilevel lumbar fusion during this time period. The average age was 63 years. Questionnaires were obtained to screen and identify patients who participated in 1 of 3 recreational sports before surgery (golf, swimming, and biking). Preoperative and postoperative collected outcome measures were then compared using the Student t test. RESULTS: Of the 117 identified lumbar fusion patients, 32 patients (27%) participated in 1 of the 3 most common recreational sporting activities of golf, swimming, or biking. Within the golf cohort (n=13), 100% of patients returned to recreational golfing postoperatively. There was a statistically significant reduction in Visual Analog Scale (VAS) pain scores postoperatively (6.3±3.7-1.8±2.4, P=0.01). Driving distance was reduced postoperatively (223.3±42.7-212.1±44.4 yards, P=0.042) and handicaps increased (12.8±8.4-17.0±11.4, P=0.02). Within the swimming cohort (n=9), 100% of patients returned to recreational swimming following lumbar fusion. There was a statistically significant reduction in VAS pain scores postoperatively (9.1±1.7-2.2±2.3, P=0.01). There was a trend towards increased amounts of swimming (times per week) postoperatively, however, this was not statistically significant (2.1±1.7-3.7±1.5, P=0.10). Within the biking cohort (n=10), 100% of patients returned to recreational biking following lumbar fusion. There was a statistically significant reduction in VAS pain scores postoperatively (6.7±4.0-1.3±1.7, P=0.03). There was a trend towards increased amounts of biking (times per week) postoperatively, however, this was not statistically significant (2.5±1.8-3.7±1.6 postoperatively, P=0.20). CONCLUSIONS: In the cohort of patients from this study who partook in golfing, swimming or bicycling, 100% were able to return to their respective sport by 3-9 months postoperatively and all had a significant reduction in pain. With regards to golfers, lumbar fusion likely has an adverse effect on their golfing ability with an increase in handicap and an expected reduction in driving distance.

A Prospective Evaluation of Point of Care Ultrasound Teaching in Switzerland.

CONTEXT: As the utility of point-of-care ultrasound (POCUS) continues to expand in the medical field, there is a need for effective educational methods. In Switzerland, medical education follows the European model and lasts 6 years, focusing on preclinical training during the first 2 years. No previous studies have evaluated the optimal time for teaching ultrasound in European medical education. AIMS: The aim of this study is to provide ultrasound training to medical students in Switzerland at varying times during their clinical training to determine if the level of training plays a role in their ability to comprehend and to apply basic POCUS skills. METHODS: We performed an observational study utilizing a convenience sample of Swiss medical students between July 11, 2016 and August 6, 2016. They were taught a 2-day POCUS course by five American-trained 1st-year medical students. Following this course, students were evaluated with written and clinical examination. RESULTS: 100 Swiss medical students were enrolled in the study. A total of 59 of these students were early clinical students, and 41 students were late clinical students. A two-tailed t-test was performed and demonstrated that the late clinical students performed better than the early clinical students on the written assessment; however, no difference was found in clinical skill. CONCLUSION: Our data suggest that Swiss medical students can learn and perform POCUS after a 2-day instructional taught by trained 1st-year American medical students. No difference was found between students in early clinical training and late clinical training for the ability to perform POCUS.

Use of 3D Printed Models in Resident Education for the Classification of Acetabulum Fractures.

OBJECTIVE: To determine if three-dimensional (3D) printed models can be used to improve acetabular fracture pattern recognition and be a valuable adjunct in orthopedic resident education. DESIGN: Fifteen randomized testing stations with each containing plain radiographs (XRs), two-dimensional computed tomography (CT) scans, or 3D model of an acetabular fracture. SETTING: Two orthopedic residency programs based at Level 1 trauma centers. PARTICIPANTS: Forty-one orthopedic residents, PGY 1-5. RESULTS: Senior residents were superior to junior residents at correctly identifying the provided acetabular fracture pattern. Overall, use of CT scans or the 3D model improved fracture classification as compared to standard XRs, but there was no significant difference between use of the CT scans and 3D models. Subjective survey results indicated agreement among residents that 3D models were accurate representations of acetabular fractures and that models would be a desired educational modality. CONCLUSIONS: 3D models improved the accuracy of acetabular fracture identification compared to XR. In addition, trainees were able to use 3D models to obtain similar accuracy compared to CT scans despite not having previous exposure to the models. Interobserver agreement improved when comparing CT to 3D, but did not provide greater than a fair agreement indicating that fracture patterns were difficult to accurately classify even with the use of 3D models. Residents' subjective responses indicated a positive experience with the use of 3D models. We conclude that the incorporation of 3D models could be an important adjunct to orthopedic residency education for the evaluation complex fracture patterns, but is not significantly superior to identification with CT scans.

Mapping the electrophysiological and morphological properties of CA1 pyramidal neurons along the longitudinal hippocampal axis.

Differences in behavioral roles, anatomical connectivity, and gene expression patterns in the dorsal, intermediate, and ventral regions of the hippocampus are well characterized. Relatively fewer studies have, however, focused on comparing the physiological properties of neurons located at different dorsoventral extents of the hippocampus. Recently, we reported that dorsal CA1 neurons are less excitable than ventral neurons. There is little or no information for how neurons in the intermediate hippocampus compare to those from the dorsal and ventral ends. Also, it is not known whether the transition of properties along the dorsoventral axis is gradual or segmented. In this study, we developed a statistical model to predict the dorsoventral position of transverse hippocampal slices. Using current clamp recordings combined with this model, we found that CA1 neurons in dorsal, intermediate, and ventral hippocampus have distinct electrophysiological and morphological properties and that the transition in most (but not all) of these properties from the ventral to dorsal end is gradual. Using linear and segmented regression analyses, we found that input resistance and resting membrane potential changed linearly along the V-D axis. Interestingly, the transition in resonance frequency, rebound slope, dendritic branching in stratum radiatum, and action potential properties was segmented along the V-D axis. Together, the findings from this study highlight the heterogeneity in CA1 neuronal properties along the entire longitudinal axis of hippocampus.