Rushi Talati

Femoral Component Rotation in Total Knee Arthroplasty: An MRI-Based Evaluation of our Options

Proper femoral component rotation is crucial in successful total knee arthroplasty. Rotation using anatomic landmarks has traditionally referenced the transepicondylar axis (TEA), Whitesides Line (WSL), or posterior condylar axis (PCA). TEA is thought to best approximate the flexion-axis of the knee, however WSL or PCA are common surrogates in the operating room. This study evaluated 560 knees using MRI-based planning software to assess the relationship of WSL and PCA to the TEA and determine if the relationships were influenced by pre-operative coronal deformity. Results showed the WSL-TEA relationship has more variability than PCA-TEA and that the PCA is more internally rotated in females and valgus knees. Axis options and historical assumptions about axis relationships may need to be reassessed as imaging technology advances.

Retroprosthetic membrane formation in Boston keratoprosthesis: A case-control-matched comparison of titanium versus PMMA backplate

Purpose: Retroprosthetic membrane (RPM) formation is the most common complication after Boston type 1 keratoprosthesis (KPro) implantation. It affects visual acuity and can predispose to corneal melt. Two KPro backplate materials are available: titanium and polymethyl methacrylate (PMMA). This study investigates the influence of the KPro backplate material on visually significant RPM formation. Methods: A retrospective case–control-matched study involving 40 patients; 20 eyes implanted with a titanium backplate KPro were case-matched with 20 eyes implanted with a PMMA backplate KPro between 2007 and 2015 with 1-year minimum follow-up. Results: The mean follow-up duration was 28.1 ± 8.9 and 53.6 ± 24.3 months in the titanium and PMMA groups, respectively. At 12 months postoperatively, 7 eyes with titanium and 6 eyes with PMMA backplates developed a visually significant RPM. By the end of the study, a total of 11 eyes with titanium and 9 eyes with PMMA KPros developed a visually significant RPM. There was no statistically significant difference between both groups. Three of 11 eyes with titanium KPros that had a visually significant RPM required surgical membranectomy, whereas all eyes with PMMA KPros were successfully treated with the yttrium-aluminum-garnet laser. Recurrence of RPMs was found in 7/11 eyes in the titanium group and 2/9 eyes in the PMMA group with no statistical significance. Conclusions: Titanium backplate KPros do not significantly reduce RPM formation compared with PMMA backplate KPros in a case–control-matched setting. A larger prospective study is warranted to evaluate comparative long-term performance and guide newer designs.

Major FDA medical device recalls in ophthalmology from 2003 to 2015

OBJECTIVE To assess recent high-risk ophthalmic medical device recalls. METHODS The publicly available Food and Drug Administration Center for Devices and Radiological Health database was mined for Class I (high-risk) ophthalmic device recalls from January 1, 2003 to December 31, 2015. The number of Class I ophthalmic device recalls was quantified. Additionally, recall characteristics and market entry data were determined for each device. RESULTS Twelve Class I ophthalmic device recall events were identified, collectively affecting over 68 million units in distribution. A median of 147,491 units (range 20 to 57,252,581) were recalled per event. 9 out of 12 recalls (75%) had at least one documented occurrence of an adverse event to a patient. Pre-market related issues accounted for one device recall (8%), post-market related issues accounted for nine device recalls (75%), and two device recalls (17%) were indeterminate. 510(k) clearance was the most common pathway to market, accounting for 50% of Class I recalls. Three devices were approved through pre-market approval (PMA) pathway, two devices were exempt from review, and one device failed to register with the FDA. CONCLUSION Class I recalls surrounding ophthalmology are relatively infrequent compared to other medical specialties. However, given the impact of Class I recalls in the field, ophthalmologists have an impetus to advocate for stronger device regulation particularly in the context of post-marketing surveillance.