Multiple differing surgical techniques are currently utilized to perform total knee arthroplasty (TKA). We compared knee arthroplasties performed using either a measured resection or gap balancing technique to determine if either operative technique provides superior coronal plane stability as measured by assessment of the incidence and magnitude of femoral condylar lift-off. We performed 40 TKA using a measured resection technique (20 PCLretaining and 20 PCL-substituting) and 20 PCL-substituting TKA were implanted using gap balancing. All subjects were analyzed fluoroscopically while performing a deep knee bend. The incidence of coronal instability (femoral condylar lift-off) was then determined using a 3-D model fitting technique. The incidence of lift-off greater than 0.75 mm was 80% (maximum, 2.9 mm) and 70% (maximum, 2.5 mm) for the PCL-retaining and substituting TKA groups performed using measured resection versus 35% (maximum, 0.88 mm) for the gap-balanced group. Lift-off greater than 1 mm occurred in 60% and 45% of the PCL-retaining and -substituting TKA using measured resection versus none in the gap-balanced group. Rotation of the femoral component using a gap balancing technique resulted in better coronal stability which we suggest will improve functional performance and reduce polyethylene wear.

Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

No abstract

Patterns of motion in the native knee show substantial variability. Guided motion prosthetic designs offer stability but may limit natural variability. To assess these limits, we therefore determined the in vivo kinematic patterns for patients having a cruciate-substituting TKA of one design and determined the intersurgeon variability associated with a guided-motion prosthetic design. Threedimensional femorotibial contact positions were evaluated for 86 TKAs in 80 subjects from three different surgeons using fluoroscopy during a weightbearing deep knee bend. The average posterior femoral rollback of the medial and lateral condyles for all TKAs from full extension to maximum flexion was À14.0 mm and À23.0 mm, respectively. The average axial tibiofemoral rotation from full extension to maximum flexion for all TKAs was 10.8°. The average weightbearing range of motion (ROM) was 1098 (range, 608-1508; standard deviation, 18.78). Overall, the TKA showed axial rotation patterns similar to those of the normal knee, although less in magnitude. Surgeon-to-surgeon comparison revealed dissimilarities, showing the surgical technique and soft tissue handling influence kinematics in a guided-motion prosthetic design.

The novel coronavirus disease (COVID‐19) has limited traditional consultation and minimized health care access. Teledermatology (TD) has come to the rescue in this situation by extending consultation for nonessential conditions to the comfort of patient's homes. This limits the risk of exposure of both doctors and patients to the coronavirus (SARS‐CoV‐2). And while there is a reported increase in teleconsultations during the ongoing pandemic, there are some demerits that avert the shift to virtualized health care. The authors conducted an online survey to further understand the hesitancy, limitations, merits, and the demographic of dermatologists who were conducive to TD and these data were analyzed and presented in this article. While TD might never replace physical consultation, it definitely serves an adjunctive role in the post‐COVID era, provided adequate regulatory measures are in place.