Soft tissue laxity is highly variable in patients undergoing total knee arthroplasty.

BACKGROUND: One major goal of total knee arthroplasty (TKA) is to achieve balanced medial and lateral gaps in flexion and extension. While bone resections are planned by the surgeon, soft tissue laxity is largely intrinsic and patient-specific in the absence of additional soft tissue releases. We sought to determine the variability in soft tissue laxity in patients undergoing TKA. METHODS: We retrospectively reviewed 113 patients undergoing TKA. Data on preoperative knee deformity were collected. Data from a dynamic intraoperative stress examination were collected by a robotic tracking system to quantify maximal medial and lateral opening in flexion (85-95 degrees) and extension (-5-20 degrees). T-tests were used to assess the differences between continuous variables. RESULTS: A valgus stress opened the medial compartment a mean of 4.3 ± 2.3 mm (0.0-12.4 mm) in extension and 4.6 ± 2.3 mm (0.0-12.9 mm) in flexion. A varus stress opened the lateral compartment a mean of 5.4 ± 2.4 mm (0.3-12.6 mm) in extension and 6.2 ± 2.5 mm (0.0-13.4 mm) in flexion. The medial compartment of varus knees opened significantly more in response to valgus stress than valgus knees in both extension (5.2 mm vs. 2.6 mm; P < 0.0001) and flexion (5.4 mm vs 3.3 mm; P < 0.0001). The lateral compartment of valgus knees opened significantly more in response to varus stress than varus knees in both extension (6.7 mm vs. 4.8 mm; P < 0.0001) and flexion (7.4 mm vs. 5.8 mm; P = 0.0003). CONCLUSIONS: Soft tissue laxity is highly variable in patients undergoing TKA, contributing anywhere from 0-13 mm to the post-resection gap. Only a small part of this variability is predictable by preoperative deformity. These findings have implications for either measured-resection or gap-balancing techniques. LEVEL OF EVIDENCE: Level III.

Incidence of Lateral Femoral Cutaneous Nerve Dysfunction After Total Hip Arthroplasty Through the Anterior-Based Muscle-Sparing Surgical Approach.

Background: The anterior-based muscle-sparing (ABMS) approach, using the intramuscular interval between the tensor fascia lata and gluteus medius, is an increasingly popular total hip arthroplasty (THA) approach. Its incidence of lateral femoral cutaneous nerve (LFCN) numbness has not been defined. The incidence of LFCN symptoms in direct anterior THA ranges from 7%-32% at 1-year follow-up. The purpose of this study is to determine the incidence of LFCN symptoms in patients who underwent ABMS THA at 1-year follow-up. Methods: This was a single-center, multisurgeon retrospective study of ABMS THAs with minimum 1-year follow-up data between January 2014 and September 2021. Eight hundred sixty-nine THAs were included. Mean age of the patients was 67.2 years, with 43.4% male and 56.5% female. Mean body mass index was 26.8, and mean American Society of Anesthesiologists was 2.3. Statistical analysis included chi-square tests, 2-sample t-test, and binomial logistic regression. A P-value of .05 was considered statistically significant for all tests. Results: Nine patients (1%) reported LFCN-associated symptoms at 1-year follow-up. The most common complaint was numbness (n = 5, 55.6%), followed by diminished sensation (n = 2, 22.2%), burning (n = 1, 11.1%), and generalized pain (11.1%). There was no difference in age, sex, body mass index, or American Society of Anesthesiologists between the group that experienced symptoms and the group that did not (P = 1.00, P = .34, P = .74, P = .80). Conclusions: The incidence of LFCN dysfunction is 1% at 1 year after surgery with the ABMS approach. Additional studies may elucidate all risks and benefits of the ABMS approach with respect to LFCN injuries.

Cost-effectiveness of closed-incision negative pressure therapy in primary total joint arthroplasty: a break-even analysis.

OBJECTIVE: Surgical site complications (SSCs) are the leading cause of unplanned emergency department visits and readmissions following total joint arthroplasty (TJA). The use of closed-incision negative pressure therapy (ciNPT) has shown promise in reducing SSC occurrence. However, no study has evaluated the cost-effectiveness of ciNPT in primary TJA. The purpose of this study was to calculate the break-even absolute risk reduction (ARR) of SSCs, the break-even treatment cost of SSCs, and the break-even cost-of-use for ciNPT, based on existing literature to assess the cost-effectiveness of ciNPT in primary TJA. METHOD: Relevant values for ARR, infection treatment cost and intervention cost were obtained via literature review. A break-even analysis was conducted to investigate the cost-effectiveness of ciNPT use in primary TJA, as well as to derive the ARR, infection treatment cost (Ct) and intervention protocol cost (Cp) values at which ciNPT use becomes cost-effective. RESULTS: The values derived from the literature review were as follows: Cp=$160.76 USD; Ct=$5348.78 USD; ARR=0.0375. The break-even ARR was calculated to be 3.0%, the break-even Cp was calculated to be $200.58 USD, and the break-even Ct was calculated to be $4286.93 USD. The ARR of ciNPT use was greater than the calculated break-even ARR. CONCLUSION: This analysis demonstrated that ciNPT use in primary TJA was cost-effective. By examining the difference between the calculated break-even Cp and the Cp reported in the literature, the cost saved per patient treated with ciNPT can be calculated to be $39.82 USD.

Surgeon-Applied Stress and a Ligament Tensor Instrument Provide a Similar Assessment of Preresection Flexion Laxity During Robotic Total Knee Arthroplasty.

Background: Robotic-assisted total knee arthroplasty (RA-TKA) allows surgeons to perform intraoperative soft tissue laxity assessments prior to bone resections and is used to alter resections to achieve gap balance. This study compared 2 techniques for flexion gap laxity assessment during RA-TKA. Methods: A prospective study of 50 primary RA-TKAs performed by a single surgeon was conducted between February and October 2023. Following full exposure, anterior tibial dislocation, and osteophyte removal, maximal medial and lateral compartment flexion laxity was quantified to the nearest 0.5 mm by the robotic system using a dynamic, surgeon-applied stress (SURGEON). This data was used to plan a balanced flexion gap by adjusting the femoral component size, rotation, and anterior-posterior translation. Flexion laxity was quantified again after distal femoral and proximal tibial resections using a ligament tensor instrument (TENSOR). These new data were used to plan for the same desired flexion gap using the same variables. Paired-samples t-tests and a simple linear regression were used for analysis. Results: Both methods produced near-identical recommendations for femoral component sizing (mean deviation 0.06 sizes, range -1 to +1 size; P = .569), rotation (deviation mean 1.0°, range -3.0° to +3.0°; P = .741), and anterior-posterior translation (deviation mean 0.13 mm, range -0.5 to +0.5 mm, P = .785). SURGEON femoral component rotation predicted TENSOR rotation (R2 = 0.157; 95% confidence interval = 0.124, 0.633; P = .004). Conclusions: Assessing flexion laxity with a surgeon-applied stress vs a ligament tensor produced near-identical laxity data in RA-TKA, suggesting surgeons may comfortably choose either technique as a reliable method. Level of Evidence: Level III.

Midterm results for revision total knee arthroplasty for component malrotation.

INTRODUCTION: Accurate positioning of components in total knee arthroplasty (TKA) is essential to a satisfactory outcome. Significant malrotation may lead to chronic pain, stiffness, and dysfunction. This study aims to quantify improvements in functional outcomes following revision surgery for malrotation of either one or both components in TKA versus revision for aseptic loosening. METHODS: This was a retrospective review of TKAs that matched and compared the two-year functional outcomes of the malrotation group to a functionally similar aseptic loosening group. Functional outcomes were compared between groups using Short Form (SF-12), Western Ontario and McMaster University Osteoarthritis Index (WOMAC), and Knee Society Functional Score (KSFS). Student t-tests and chi-squared or Fisher's tests were used for statistical analysis. RESULTS: Of the patients revised, 24 had malrotation and 57 had aseptic loosening. A total of 16 femoral and 17 tibial components were revised for malrotation. All 16 femoral components were internally malrotated (mean -4.8 ± 4.1 degrees; range, -0.5 to -16.6). Of the tibial components, 15 were internally malrotated, (mean -9.5 ± 6.6 degrees; range, -2.2 to -23.5) and 2 were externally malrotated (mean 4.6 ± 2.1 degrees; range, 3.1 to 6.0). All functional outcome measures significantly improved comparably within both groups preoperatively to 24 months postoperatively. At 24 months, functional outcome measures were comparable between the groups and WOMAC function scores were significantly higher in the malrotation group. CONCLUSION: Revision TKA for malrotation can yield clinically and statistically significant functional improvements, similar in magnitude to those seen following revision TKA for aseptic loosening. LEVEL OF EVIDENCE: Level III.

Complications and Survivorship After Aseptic Revision Total Hip Arthroplasty: Is There a Difference by Surgical Approach?

BACKGROUND: Revision total hip arthroplasty (rTHA) has traditionally been performed through the posterolateral approach (PA). Anterior approaches (AA) for rTHA are increasingly being utilized. The purpose of this study was to compare complications and survivorship from re-revision and reoperation after aseptic rTHA performed using an AA versus a PA. METHODS: We retrospectively reviewed patients who underwent aseptic rTHA either through an AA (direct anterior approach [DAA], anterior-based muscle sparing [ABMS]) or PA from January 2017 to December 2021. There were 116 patients who underwent AA-rTHA (DAA 50, ABMS 66) or PA-rTHA (n = 105). Patient demographics, complications, and postoperative outcomes were collected. RESULTS: The most common indication in both groups was aseptic loosening (n = 26, 22.4% AA, n = 28, 26.7% PA). Acetabular revision alone was most common in the AA group (n = 33, 28.4%), while both components were most commonly revised in the PA groups (n = 47, 44.8%). In all the AA-rTHA group, the index total hip arthroplasty was performed through a PA in 51% of patients, while the PA-rTHA group had the index procedure performed via AA in 4.8%. There was no statistically significant difference in re-revision rate between the DAA, ABMS, or PA groups (9.55 versus 5.3% versus 11.4%, respectively, P = .11). The most common overall reason for re-revision was persistent instability, with no difference in incidence of postoperative hip dislocation (n = 4, 6.8% DAA, n = 3, 5.3%, n = 10, 9.5% PA; P = .31). CONCLUSIONS: This study demonstrates no difference in complication or re-revision survivorship after aseptic rTHA performed through a DAA, ABMS approach, or PA, nor between anterior or posterior-based approaches. LEVEL OF EVIDENCE: Level III.

2-Octyl-Cyanoacrylate Mesh Dressings for Total Joint Arthroplasty: Dressing Design Influences Risks of Wound Complications.

BACKGROUND: Recent liquid adhesive skin closure systems with a mesh patch and a 2-octyl cyanoacrylate liquid formula have shown promising results in total joint arthroplasty. Chemical accelerators are typically included to promote the rapid polymerization of 2-octyl cyanoacrylate. The goal of the study is to distinguish designs and wound complication differences between 2 similar systems. METHODS: An 18-week retrospective study was conducted from July to December 2023, including 207 total hip arthroplasty and 212 total knee arthroplasty cases from 4 attending surgeons at 1 institution that used 1 of 2 dressing designs. Both dressings had a 2-octyl cyanoacrylate liquid adhesive formula that applied topically to a polyester-based mesh overlaying the wound. Mesh A (used in 274 cases) included an accelerator, a quaternary ammonium salt, on the mesh patch, whereas Mesh B (used in 145 cases) included a similar accelerator within the adhesive applicator. RESULTS: Wound complications (3.2 versus 7.6%; X2 = 3.86; df = 1; P = .049), early periprosthetic joint infections (0 versus 2.8%; X2 = 7.63; df = 1; P = .006), and 90-day reoperations for wound complications (0.4 versus 3.4%; X2 = 6.39; df = 1; P = .011) were significantly lower in patients who received Mesh A versus B, respectively. There was no difference in superficial surgical site infections (0.7 versus 0%; X2 = 1.06; df = 1; P = .302) or allergy rates (3.3 versus 4.1%; X2 = 0.12; df = 1; P = .655) between Mesh A and B. CONCLUSIONS: We observed significantly different performance in wound complications, early postoperative periprosthetic joint infections, and 90-day reoperation between the 2 designs. Having the accelerator in the applicator rather than on the mesh patch may lead to premature polymerization before bonding appropriately with the mesh to create the desired wound closure and seal. LEVEL OF EVIDENCE: Level III.

Mechanical and structural properties of articular cartilage and subchondral bone in human osteoarthritic knees.

Knee osteoarthritis (OA), characterized by multiple joint tissue degenerations, remains a significant clinical challenge. Recent evidence suggests that crosstalk within the osteochondral unit may drive OA progression. Although structural-biomechanical properties of bone and cartilage have been studied, potential interaction within the osteochondral unit in the context of OA has yet to be investigated. We performed comprehensive structural and biomechanical quantification of the cartilage, subchondral bone plate (SBP), and subchondral trabecular bone (STB) using 101 osteochondral cores collected from tibial plateaus of 12 control human cadavers (CT, 5 male/7 female) and 19 patients undergoing total knee replacement (OA, 6 male/13 female). For each sample, we quantified SBP microstructure, plate-and-rod morphological properties of the STB using individual trabecula segmentation, and morphological and compositional properties of the articular cartilage. We also performed indentation testing on each compartment of the osteochondral unit to extract the respective structural-mechanical properties. Cartilage thickness was lower in moderate and severe OA regions, while Osteoarthritis Research Society International score was higher only in severe OA regions. GAG content did not change in any OA region. Aggregate and shear moduli were lower only in severe OA regions, while permeability was lower only in moderate OA regions. In the SBP, thickness and tissue mineral density were higher in moderate and severe OA regions. Tissue modulus of STB was lower in moderate OA regions despite a thicker and more mineralized SBP; this deterioration was not observed in severe OA regions. Regression analysis revealed strong correlations between cartilage and STB properties in CT; these correlations were also found in moderate OA regions but were not observed in severe OA regions. In summary, our findings comprehensively characterize the human OA osteochondral unit. Importantly, uncoupling cartilage and subchondral bone structural-mechanical properties may be a hallmark of OA.

Knee osteoarthritis (OA) is a complex condition involving the degradation of joint tissues. To better understand OA progression, we investigated the interplay between different components of the joint. Our study focused on how cartilage, subchondral bone plate (SBP), and subchondral trabecular bone (STB) interact in human knee OA samples. We observed distinct changes in these tissues in moderate and severe OA regions compared with healthy joints. In moderate to severe OA, we found that cartilage thickness decreased, while the SBP thickened. Interestingly, the strength of the STB decreased only in moderate OA regions, not in severe OA. Moreover, our analysis revealed strong correlations between cartilage and STB properties in healthy joints and moderate OA regions. However, these correlations were absent in severe OA regions, indicating a disruption in the usual relationship between these tissues. Overall, our findings shed light on the structural and biomechanical changes occurring within the knee joint in OA. Understanding these changes may offer insights into potential therapeutic strategies for managing OA.

Does Lack of Initial Collar-Calcar Contact Influence Performance of Collared Cementless Femoral Stems?

Background: Initial stability of cementless stems is important to minimize the risk of subsidence, pain, and periprosthetic fracture after total hip arthroplasty (THA). Collared stems improve initial component stability when contacting the femoral calcar. Direct contact is not always achieved, and collared stem performance has not been studied in this context. We hypothesized that collared stems achieving direct contact would demonstrate reduced subsidence. Methods: A single-surgeon retrospective study of 482 consecutive primary THAs implanted between February 2020 and May 2023 using collared cementless stems was performed. The 2 cohorts included stems with initial collar-calcar contact vs stems without. Subsidence was evaluated by comparing intraoperative fluoroscopy to postoperative 8-week radiographs. Binary logistic regression identified independent risk factors for subsidence. Chi-square tests were used for categorical variables and t-tests for continuous variables. Results: Of stems, 63.9% achieved initial collar-calcar contact, while 36.1% did not. The rate (1.3% vs 19.0%; P < .001) and magnitude (0.02 mm, range 0-3 mm vs 0.35 mm, range 0-3 mm; P < .001) of subsidence were significantly higher among stems without initial contact. Stems without initial collar-calcar contact (P < .001) and male gender (P = .007) were independent risk factors for subsidence. Two patients with initial contact had nondisplaced calcar cracks and <3 mm of subsidence at 4 weeks, which healed with protected weight-bearing. Stem survivorship was 100% in both groups, with all achieving osteointegration and none needing revision. Conclusions: Excellent performance of collared cementless stems was observed at 8 weeks after primary THA. Initial collar-calcar contact lowered the risk and magnitude of minor subsidence but did not affect survivorship or fracture risk. Level of Evidence: Level III.

Genicular nerve radiofrequency ablation: a systematic review of application for perioperative pain control in total knee arthroplasty and as treatment for chronic pain in well-appearing total knee arthroplasty.

BACKGROUND: Total knee arthroplasty (TKA) is a successful treatment for end-stage osteoarthritis, yet some patients still experience postoperative pain. Genicular nerve radiofrequency ablation (GNRFA) has become a potential modality to address pain in TKA. This systematic review aims to critically analyze the applicability of GNRFA in perioperative pain control prior to TKA, as well as a treatment modality for chronic painful well-appearing TKA. METHODS: PubMed, Medline, EMBASE, Google Scholar, Scopus, and COCHRANE databases, as well as the ClinicalTrials.gov register, were reviewed. The search included randomized controlled trials and cohort studies. The sample population focused on two cohorts; those who underwent TKA and utilized intentional GNRFA as a perioperative pain control modality, and those utilizing the treatment modality for chronic pain in well-appearing TKA. GNRFA was the intervention studied, and postoperative outcomes were compared with the control group, which consisted of those not receiving GNRFA. RESULT: Eight total publications were identified as relevant to this search. Among the pre-TKA studies, there was variability in results; these inconsistencies were attributed to a lack of standardization, especially with regard to type, timing, and targeted nerves with ablation. Likewise, while the results were improved among the population with chronic painful TKA receiving GNRFA, these inconsistencies still existed. CONCLUSIONS: Current evidence suggests GNRFA as a possible pre-TKA intervention to potentially minimize opioid consumption, patient-reported pain, length of stay, and increased range of motion and activity. However, the short-lived duration in the setting of chronically painful well-appearing TKA represents a major barrier that warrants further investigation. Limitations include small sample size, heterogeneity, lack of standardization of techniques among studies, and lack of direct comparison and meta-analysis. Further research should focus on the standardization of technique as well as analyzing various patient and health-system-related factors that correlate with sustained positive outcomes.

Calcification within the urachus: A case report of rare presentation of urachal cyst with calculus formation.

Urachal anomalies are rare congenital lesions of the genitourinary tract and are important causes of pediatric and adolescent hospital presentations. It can mimic many other causes of intraabdominal pathology and fever, and pose diagnostic challenges, often aided by imaging, is crucial to prevent complications such as infection and calculus formation. Surgical intervention, preferably laparoscopic, is the primary treatment, with complete excision necessary to avoid potential malignant transformation.

Aseptic Revision Total Hip Arthroplasty Through an Anterior Approach: Survivorship and Risk Factors for Re-Revision.

BACKGROUND: The utilization of anterior-based approaches for total hip arthroplasty (THA) is increasing. Literature on the outcomes of revision THA (rTHA) through an anterior approach, however, is sparse. This study reports the survivorship and risk factors for re-revision in patients undergoing aseptic rTHA through an anterior approach. METHODS: This was a single-institution, retrospective cohort analysis of patients who underwent aseptic rTHA through an anterior approach (direct anterior, anterior-based muscle sparing) from January 2017 to December 2021, regardless of the original surgical approach. Exclusion criteria were age <18 years, conversion THA, and septic revisions. Patient demographics, complications, and postoperative outcomes were collected. Kaplan-Meier curves were used to measure survivorship while Cox regression analyses were used to identify risk factors for re-revision of THA. RESULTS: We identified 251 total anterior rTHAs, of which 155 were aseptic anterior revisions. There were 111 patients (111 rTHAs; 63 anterior-based muscle sparing and 48 direct anterior) who met criteria and had a mean follow-up of 4.2 years (range, 2.1 to 6.9). There were a total of 54 (49%) anterior-based index approaches and 57 (51%) posterior index approaches. The most common indications for rTHA were femoral loosening (n = 25, 22.5%), followed by instability (n = 16, 14.4%) and wear or osteolysis (n = 16, 14.4%). At 2 years, the survivorship from reoperation and re-revision was 89% (95% confidence interval: 84 to 95) and 91% (95% confidence interval: 86 to 96), respectively. Reoperation occurred in 14 patients (12.6%) at a mean time of 7.8 months (range, 0.5 to 28.6). Re-revision occurred in 12 patients (10.8%) at a mean time of 7.3 months (range, 0.5 to 28.6). Instability was the most common reason for re-revision (4.5%). Neither index approach type, revision approach type, nor any patient-specific risk factors were identified as predictors of re-revision or reoperation in multivariable regression analysis. CONCLUSIONS: This study demonstrates an acceptable rate of re-revision when aseptic rTHA is performed through an anterior approach, with the most common reason for aseptic re-revision being instability.

Specific Preoperative Factors Increase Manipulations under Anesthesia Following Primary TKA.

Arthrofibrosis following primary total knee arthroplasty (TKA) can result in pain and limit postoperative range of motion (ROM), jeopardizing clinical outcomes and patient satisfaction. This study aims to identify preoperative risk factors associated with necessitating a manipulation under anesthesia (MUA) following primary TKA.We retrospectively reviewed 950 cases of consecutive primary TKAs performed at one institution by three arthroplasty surgeons between May 2017 and May 2019. Recorded preoperative variables included smoking status, race, preoperative ROM, presence of effusion or positive anterior drawer, and medical comorbidities. Demographic characteristics were compared with Student's t-tests or chi-square tests as appropriate. For each preoperative factor, we obtained an odds ratio (OR) for MUA risk using multivariate logistic regression.Twenty (2.3%) patients underwent MUA following their index primary TKA surgery. History of ipsilateral knee surgery (OR: 2.727, p = 0.047) and diagnosed hypertension (OR: 4.764, p = 0.016) were identified as risk factors associated with significantly increased risk of MUA. The greater the preoperative ROM, the higher likelihood needed of MUA (OR: 1.031, p = 0.034).Patients who had diagnosed hypertension or a history of prior ipsilateral knee surgery were associated with increased risk of necessitating an MUA following primary TKA. Additionally, a greater total arc of motion preoperatively increased the odds of needing MUA.Level III of evidence was present.

Use of The Risk Assessment and Prediction Tool to Predict Same-day Discharge After Primary Hip and Knee Arthroplasty.

INTRODUCTION: The Risk Assessment and Prediction Tool (RAPT) is a preoperative screening tool developed to predict discharge disposition after total hip arthroplasty (THA) and total knee arthroplasty (TKA), but its predictive value for same-day discharge (SDD) has not been investigated. The aims of this study were (1) to assess RAPT's ability to predict SDD after primary THA and TKA and (2) to determine a cutoff RAPT score that may recognize patients appropriate for SDD. METHODS: Data were retrospectively collected from patients undergoing primary THA and TKA at a single tertiary care center between February 2020 and May 2021. A receiver operating characteristic curve was generated to choose a cutoff value to screen for SDD. Logistic regression analysis was done to identify factors including age, BMI, or RAPT score that may be associated with SDD. RESULTS: Three hundred sixty-one patients with preoperative RAPT scores were included in the analysis of whom 147 (42.6%) underwent SDD. A cutoff of ≥9 was identified for TKA and ≥11 for THA. RAPT had a predictive accuracy of only 66.7% for SDD, whereas the discharge plan documented in the preoperative note was 91.7% accurate. DISCUSSION: Although there is a positive association between RAPT and SDD, it is not a useful screening tool given its low predictive accuracy.

Scheduling and Vendor Consistency Improves Turnover Time Efficiency in Total Joint Arthroplasty.

BACKGROUND: Maximizing operative room (OR) efficiency is important for hospital efficiency, patient care, and positive surgeon and staff morale. Reducing turnover time (TOT) has become a popular focus to improve OR efficiency. The present study evaluated if TOT is influenced by changing case type, implant vendor, and/or laterality. METHODS: In total, 444 turnovers from January to July 2023 were retrospectively analyzed. All turnovers were same-surgeon turnovers between primary arthroplasty cases in dedicated, overlapping rooms. Single linear regression models tested the predictability of TOT based on case type, vendor, and laterality. A multivariate multiple regression and 1-way Analyses of Variance analyzed variables against each other. Independent sample t-tests evaluated TOTs when all variables were the same or different. RESULTS: Changing versus keeping the same case type increased TOT by 2.4 minutes (95% confidence interval [CI] = 0.7, 4.0; P = .004). Changing vendors increased TOT by 2.9 minutes (95% CI = 1.1, 4.7; P = .002). Laterality did not affect TOT, with a change of 0.9 minutes (95% CI = -0.6, 2.5; P = .229). Vendor (P = .030) independently predicted TOT when analyzed as a covariate with case type (P = .410). The TOT with same case type and vendor (mean 38.2 minutes; range, 22 to 62) was less than that of different case types and vendors (mean 41.4 minutes; range, 26 to 73) (P = .017). Mean TOT differed by 5.5 minutes when keeping all variables the same versus all different (P = .018). CONCLUSIONS: Maintaining a consistent case type, vendor, and laterality had a synergistic effect in reducing TOT in arthroplasty ORs with the same primary surgeon running 2 overlapping rooms. Changing vendor representatives was found to independently predict TOT increases, which is likely attributed to a disruption in workflow and collaboration of the multidisciplinary OR team. LEVEL OF EVIDENCE: Level III.

Accuracy of the Lesser Trochanter Profile as a Marker of Femoral Rotation: Computed Tomography-Based Study of 1,722 Femora.

BACKGROUND: The lesser trochanter (LT) profile is an often-used marker for proximal femoral rotation, particularly during the operative fixation of femoral fractures. Previous studies have come to conflicting conclusions about its reliability for this purpose. METHODS: The SOMA (Stryker Orthopaedic Modeling and Analytics) database (Stryker) was used to identify 1,722 computed tomographic (CT) scans of whole femora. Each femur was taken through an 80° rotational arc in 2.5° increments, and the LT profile was constructed for each position. These 56,826 LT profile measurements were then correlated with the femoral rotation. RESULTS: Across the arc of motion studied, the LT correlated weakly with proximal femoral rotation (R 2 = 0.32). There was a 35° arc, between 10° and 45° relative external rotation of the proximal femur, within which the LT profile only changed by 1 mm. The mean overall femoral anteversion was 21.2°, and women tended to have more femoral anteversion (23.9°) than men (19.2°). On average, men had a 1.6-mm more prominent LT than women. Side-to-side differences in femoral anteversion as well as LT position and size were not significant or were clinically unimportant. CONCLUSIONS: A large-scale, CT-based study shows that the LT profile is a less reliable marker of proximal femoral rotation than previously thought. This is true particularly if there is relative external rotation of the proximal femur, where the proximal femur can undergo up to 35° of rotation before 1 mm of change in the LT profile occurs. Care must be taken to check other markers of rotation such as by clinical examination during fixation of femoral fractures and not rely solely on the LT profile. CLINICAL RELEVANCE: In the largest study of its kind, this CT-based study of 56,826 LT profile measurements found that when the proximal femur is externally rotated, the LT profile becomes an unreliable marker of rotation, which can lead to excessive internal rotation of the distal fracture fragment. The LT profile should be used with caution, and confirmation of rotation by other means is recommended.

A Network Pharmacology-based Study on the Anti-aging Properties of Traditional Chinese Medicine Sisheng Bulao Elixir.

BACKGROUND: Traditional Chinese Medicine (TCM) has a rich history of use in preventing senescence for millennia in China. Nonetheless, a systematic method to study the antiaging properties and the underlying molecular mechanism of TCM remains absent. OBJECTIVE: The objective of this study is to decipher the anti-aging targets and mechanisms of Sisheng Bulao Elixir (SBE) using a systematic approach based on a novel aging database and network pharmacology. METHODS: Bioactive compounds and target proteins in SBE were identified via the Traditional Chinese Medicine System Pharmacology (TCMSP) database. Aging-related proteins were uncovered through alignment with the Ageing Alta database. A compound-target (CT) protein network analysis highlighted key flavonoids targeting aging. Core aging-related proteins were extracted through protein-protein interaction (PPI) network analysis. Molecular docking validated binding activities between core compounds and aging-related proteins. The antioxidant activity of SBE was confirmed using an in vitro senescent cells model. RESULTS: A total of 39 active compounds were extracted from a pool of 639 compounds in SBE. Through a matching process with the Aging Alta, 88 target proteins associated with the aging process were identified. Impressively, 80 out of these 88 proteins were found to be targeted by flavonoids. Subsequently, an analysis using CT methodology highlighted 11 top bioactive flavonoids. Notably, core aging-related proteins, including AKT1, MAPK3, TP53, VEGFA, IL6, and HSP90AA1, emerged through the PPI network analysis. Moreover, three flavonoids, namely quercetin, kaempferol, and luteolin, exhibited interactions with over 100 aging-related proteins. Molecular docking studies were conducted on these flavonoids with their shared three target proteins, namely AKT1, HSP90AA1, and IL6, to assess their binding activities. Finally, the antioxidant properties of SBE were validated using an in vitro model of senescent cells. CONCLUSION: This study offers novel insights into SBE's anti-aging attributes, providing evidence of its molecular mechanisms. It enhances our understanding of traditional remedies in anti-aging research.

Tourniquet-free minimally invasive total knee arthroplasty is associated with early aseptic loosening.

BACKGROUND: While tourniquet-free (T-) total knee arthroplasty (TKA) has gained popularity, tourniquet-use during minimally-invasive (MIS)-TKA has not been adequately studied. Traditional techniques employ knee hyper-flexion, compressing vasculature and reducing impact of bleeding, while MIS-TKA embraces the semi-extended knee position, which does not restrict the effects of bleeding on cementation and visualization. We compared the risk of aseptic loosening between patients undergoing T- MIS-TKA compared to T + MIS-TKA. METHODS: This single-surgeon cohort study included 329 consecutive MIS-TKA (226 T+,103 T-) patients with minimum 3-year follow-up. Aseptic loosening, radiolucent lines (RLL), health related quality of life scores, and complications were recorded. T-test and chi-square test were used to compare continuous and categorical variables, and logistic regression included BMI, age, ASA, patellar-resurfacing, and tourniquet-use. RESULTS: There were no differences in baseline demographics. One (0.4 %) aseptic loosening occurred with T+, versus 7 (6.8 %) with T- (p = 0.002). No T + and 3 T- patients (2.9 %, p = 0.01) had revision for aseptic loosening. The incidence of RLLs was 16.8 % in T + and 30.1 % in T- (p = 0.008). Logistic regression revealed T + was significantly associated with decreased aseptic loosening and risk of RLL (odds ratio = 16.4, odds ratio = 2.8). CONCLUSION: In this consecutive series, T- MIS-TKA was associated with increased rates of revision for aseptic loosening as compared to the T + MIS-TKA, even controlling for BMI, age, ASA level, and patellar resurfacing. Radiolucent lines were increased with T- MIS-TKA compared to T + MIS-TKA. Complications, all-cause revision, ROM, and HRQoL scores were similar between tourniquet-use and tourniquet-free cohorts.

Robotic Total Knee Arthroplasty is Associated with Earlier Return of Postoperative Range of Motion.

INTRODUCTION: Postoperative range of motion (ROM) is an important measure for the functional outcome and overall success after total knee arthroplasty (TKA). While robotic knee systems have been shown to reduce pain and improve early function, the return of postoperative ROM specifically has not been adequately studied. The purpose of this study was to compare postoperative ROM in robotic and conventional TKA. We hypothesized that robotic TKA leads to an improvement in postoperative ROM. MATERIALS AND METHODS: A retrospective cohort study of 674 primary TKAs by a single surgeon between January 2018 and February 2023 was completed. Patients that did not have both a two-week follow up and eight-week follow up were excluded. Revision/conversion TKAs were excluded. The population was divided into two cohorts based on technique utilized: robotic versus conventional. Preoperative extension/flexion data, postoperative extension/flexion data at two-week and eight-week follow ups, and manipulation under anesthesia data were collected. ROM was defined as flexion minus extension. Chi-square tests were used to examine for differences between categorical variables and t-tests for continuous variables. RESULTS: A total of 307 robotic and 265 conventional knees were included. There were no differences in demographics, mean follow up, or preoperative ROM between groups. The robotic group had significantly more flexion (99.20° vs. 96.98°; p=0.034) and ROM (97.81° vs. 95.56°; p=0.047) at the two-week follow up. The loss in ROM at the two-week follow up from preoperative ROM was significantly less for the robotic group (-11.21° vs. -14.16°; p=0.031). There were no significant differences in extension at either follow up, in flexion at the eight-week follow up, or in ROM at the eight-week follow up. CONCLUSION: Robotic TKA leads to an improvement in postoperative flexion and ROM when compared to preoperative ROM at two-week follow up. These findings could partially explain the quicker recovery associated with robotic TKA.

Stem cells from human exfoliated deciduous teeth rejuvenate the liver in naturally aged mice by improving ribosomal and mitochondrial proteins.

BACKGROUND AIMS: Aging is accompanied by a decline in cellular proteome homeostasis, mitochondrial, and metabolic function. Mesenchymal stromal cell (MSC) therapies have been reported to extend lifespan and delay some age-related pathologies, yet the anti-aging rate and mechanisms remain unclear. Here, we investigated the effects and mechanism by transplantation of stem cells from human exfoliated deciduous teeth (SHED) into the naturally aged mice model. METHODS: SHED were cultured in vitro and injected into mice by caudal vein. The in vivo imaging uncovered that SHED labeled by DiR dye mainly migrated to the liver, spleen, and lung organs of wild-type mice. As the main metabolic organ and SHED homing place, the liver was selected for proteomics and aging clock algorithm (LiverClock) analysis, which was constructed to estimate the proteomic pattern related to liver age state. RESULTS: After 6 months of continuous SHED injections, the liver proteomic pattern was reversed from senescent (∼30 months) to a youthful state (∼3 months), accompanied with upregulation of hepatocytes marker genes, anti-aging protein Klotho, a global improvement of liver functional pathways proteins, and a dramatic regulation of ribosomal and mitochondrial proteins, including upregulation of translation elongation and ribosome-sparing proteins Rpsa and Rplp0; elongation factors Eif4a1, Eef1b2, Eif5a; protein-folding chaperones Hsp90aa and Hspe1; ATP synthesis proteins Atp5b, Atp5o, Atp5j; and downregulation of most ribosomal proteins, suggesting that the proteome homeostasis destruction and mitochondria dysfunction in the aged mice liver might be relieved after SHED treatment. CONCLUSIONS: SHED treatment could dramatically relieve the senescent state of the aged liver, affect ribosome component proteins and upregulate the ribosomal biogenesis proteins in the aged mice liver. These results may help understand the improvements and mechanisms of SHED treatment in anti-aging.