A Targeted Approach to Ligament Balancing Using Kinetic Sensors.

BACKGROUND: Currently, soft-tissue imbalance contributes to several of the foremost reasons for revision following primary TKA, including instability, stiffness, and aseptic loosening. In order to decrease the incidence of soft-tissue imbalance, intraoperative sensors were developed to provide real-time, quantitative load data within the knee. This study examines the intraoperative data of a group of multicenter patients to determine how targeted ligament releases affect intra-articular loading, and to understand which types of releases are necessary to achieve quantified ligament balance. METHODS: A group of 129 patients received sensor-assisted TKA, as part of a multicenter study. Medial and lateral loading data were collected pre-release, during any sequential releases, and post-release. All data were collected at 10°, 45°, and 90° during range of motion testing. Ligament release type, release technique type, and resultant loading were collected. RESULTS: Loading across the joint decreased, overall, and became more symmetrical after releases were performed. On average, between 2 and 3 corrections were made (up to 8) in order to achieve ligament balance. The ligament release type and subsequent quantified change in loading were in agreement with historical, qualified sources. CONCLUSION: Objective data from sensor output may assist surgeons in decreasing loading variability and, thereby, decreasing ligament imbalance and its associated complications.

A new method for defining balance: promising short-term clinical outcomes of sensor-guided TKA.

Recently, technological advances have made it possible to quantify pounds of pressure across the bearing surface during TKA. This multicenter evaluation, using intraoperative sensors, was performed for two reasons: 1) to define "balance" 2) to determine if patients with balanced knees exhibit improved short-term clinical outcomes. Outcomes scores were compared between "balanced" and "unbalanced" patients. At 6-months, the balanced cohort scored 172.4 and 14.5 in KSS and WOMAC, respectively; the unbalanced cohort scored 145.3 and 23.8 in KSS and WOMAC (P < 0.001). Out of all confounding variables, balanced joints were the most significant contributing factor to improved postoperative outcomes (P < 0.001). Odds ratios demonstrate that balanced joints are 2.5, 1.3, and 1.8 times more likely to achieve meaningful improvement in KSS, WOMAC, and activity level, respectively.

Are morbidly obese patients undergoing total hip arthroplasty at an increased risk for component malpositioning?

Acetabular cup positioning is a critical factor in determining adverse clinical outcomes in THA. This evaluation was performed to determine if morbid obesity (BMI ≥35kg/m(2)) is a contributing risk factor to cup malpositioning. Two groups of patients were obtained from a local arthroplasty registry and match-controlled for gender, age, and diagnosis (n=211 morbidly obese; n=211 normal). Intraoperative data and postoperative AP pelvis and cross-table lateral radiographs were obtained for each patient. The Martell Hip Analysis Suite was used to calculate cup positioning (successful positioning defined as 30°-45° of abduction, and 5°-25° of anteversion), as well as varus-valgus alignment of the femoral stem. There was a significant correlation between morbid obesity with respect to underanteversion; using multivariate analysis, there was a trend toward a combined underanteversion/overabduction of the acetabular cup. Of all variables considered, high BMI was the most significant risk factor leading to malpositioning.

Endocrine Therapy Plus Anti-HER2 Therapy as Adjuvant Systemic Therapy for Luminal HER2-Positive Breast Cancer: An Analysis of the National Cancer Database.

BACKGROUND: Guidelines regarding the usage of adjuvant systemic therapy in patients with small human epidermal growth factor receptor 2 (HER2)-positive and estrogen receptor/progesterone receptor-positive (luminal HER2 positive) tumors are nonspecific. Outcomes of chemotherapy followed by endocrine therapy (ET), with or without anti-HER2 therapy, vs ET alone (no chemotherapy) have not been widely studied in this disease subtype. We sought to examine the usage and outcomes of adjuvant systemic therapy (ET vs chemotherapy with or without trastuzumab) in stage I luminal HER2-positive breast cancer (BC), based on the large National Cancer Database. METHODS: We conducted a retrospective analysis of patients with luminal HER2-positive stage I BC, diagnosed between 2010 and 2015, in the United States, using univariable and multivariable logistic regression analyses. The Kaplan-Meier method estimated overall survival (OS). RESULTS: A total of 37 777 patients were included in the analysis; of these, n = 32 594 (86%) received adjuvant ET and n = 5183 (14%) received chemotherapy. Around 40% of all patients received anti-HER2 therapy (trastuzumab). Patients who received trastuzumab had a better 5-year OS (93.4% vs 92.0%, P = .0002) compared with those who did not. Patients who received anti-HER2 therapy plus ET had the best OS rate at 5 years (93.5%, confidence interval [CI]: 89.2%-98%, P < .0001) compared with those receiving anti-HER2 therapy plus chemotherapy (92.7%, CI: 89.4%-96.1%, P < .0001). CONCLUSIONS: Most patients in the United States, with stage I luminal HER2 positive BC, received ET, not chemotherapy but most of them do not receive anti-HER2 therapy resulting in inferior outcome. Future trials exploring the de-escalation of systemic adjuvant therapy for early-stage luminal HER2-positive BC to ET plus anti-HER2 therapy would be desirable.

A novel technique using sensor-based technology to evaluate tibial tray rotation.

Rotational tibiofemoral congruency and centralized patellar tracking are critical technical factors that affect the postoperative success of total knee arthroplasty (TKA). Several techniques are used to position the femoral component, but there is no validated method for achieving the ideal rotational position of the tibial component. It has been suggested that referencing the midmedial third of the tibial tubercle intraoperatively mitigates positional outliers. This study used data collected from intraoperative sensors to quantify the variability associated with using the midmedial third of the tibial tubercle in 170 patients undergoing primary TKA. With the sensor-equipped trial insert in place, the knee was taken into extension and the location of the femoral condylar contact point on the articular surface of the tibial insert was displayed. Rotational adjustments of the tibial tray were evaluated in real time as the surgeon corrected tray malpositioning. The initial and final angles of tibial tray rotation were captured and recorded with intraoperative video feed. When referencing the tubercle, 53% of patients had asymmetric tibiofemoral congruency in extension. Of those patients, 68% had excessive internal rotation of the tibial tray relative to the femur and 32% had excessive external rotation. The average tibiofemoral incongruency deviated from a neutral position by 6° (range, 0.5°-19.2°). Data from this evaluation suggest that use of the tibial tubercle to maximize tibiofemoral congruency is highly variable and inconsistent for confirming the final rotation of the tibial tray.

A Systematic Literature Review of Three Modalities in Technologically Assisted TKA.

In effort to reduce the revision burden of total knee arthroplasty (TKA), industry emphasis has focused on replacing manual techniques-which are subject to variability-with technological implements. Unfortunately, technological innovation often continues before adequate time for critical evaluation has passed. Therefore, the purpose of this descriptive literature review was to collect a large sample of international data and report on the clinical and economic efficacy of three major types of technologically assisted TKA: navigation, patient-specific instrumentation, and sensorized trials.

Primary TKA Patients with Quantifiably Balanced Soft-Tissue Achieve Significant Clinical Gains Sooner than Unbalanced Patients.

Although total knee arthroplasty has a high success rate, poor outcomes and early revision are associated with ligament imbalance. This multicenter evaluation was performed in order to provide 1-year followup of a previously reported group of patients who had sensor-assisted TKA, comparing the clinical outcomes of quantitatively balanced versus unbalanced patients. At 1 year, the balanced cohort scored 179.3 and 10.4 in KSS and WOMAC, respectively; the unbalanced cohort scored 156.1 and 17.9 in KSS and WOMAC (P < 0.001; P = 0.085). The average activity level scores of quantitatively balanced patients were 68.6 (corresponding to tennis, light jogging, and heavy yard work), while the average activity level of unbalanced patients was 46.7 (corresponding to light housework, and limited walking distances) (P = 0.015). Out of all confounding variables, a balanced articulation was the most significant contributing factor to improved postoperative outcomes (P < 0.001).