Archive | September 2019

Patient Discharge after Knee Replacement: How Soon Is Safe?

For most patients and payers, getting out of the hospital quickly after a knee replacement is very important. For orthopaedic surgeons, excellent patient outcomes are the top priority. The latest one-hour complimentary webinar from JBJS on Tuesday, October 1, 2019 at 8:00 pm EDT will reveal clinical practices that increase the odds of achieving both of those goals.

Co-authors Nelson SooHoo, MD and Armin Arshi, MD will explore data from their JBJS study comparing complication rates after outpatient and inpatient knee-replacement, emphasizing that outpatients must receive the same attention to infection prevention, thromboprophylaxis, and rehabilitation as inpatients.

Kurt Spindler, MD and Robert Molloy, MD will then delve into their JBJS study, which suggests that hospital site, surgeon, and day of the week are more accurate predictors of length of hospital stay after knee replacement than patient age, BMI, and comorbidities.

Moderated by Daniel Berry, MD of the Mayo Clinic, the webinar will also feature expert commentaries by Joseph Moskal, MD and Ronald Delanois, MD. The webinar will conclude with a 15-minute live Q&A session during which attendees can ask questions of all the panelists.

Seats are limited, so Register Now!

Plate–Tendon Contact: How Important Is It?

There are few things more discouraging for an orthopaedic surgeon than a late postoperative complication after what was an otherwise successful surgery. One such scenario occurs when patients who have undergone open reduction/internal fixation (ORIF) for a distal radial fracture subsequently experience a flexor pollicis longus (FPL) tendon rupture. While previous literature has suggested that plate positioning plays a role in that complication, no studies have evaluated whether newer plate designs decrease contact with the FPL tendon and therefore reduce the risk of rupture.

With that question in mind, Stepan et al. evaluated two cohorts of patients who had undergone ORIF for a distal radial fracture. In the September 4, 2019 issue of JBJS, they report on findings from 40 patients, 20 of whom received a standard distal radial volar locking plate, and 20 of whom received a plate designed with a distal cutout to afford the FPL more room to traverse.

Ultrasound analysis revealed that similar percentages of patients in each group had FPL–plate contact (65% in the FPL-plate group and 79% in the standard-plate group), and there were no differences between groups in terms of FPL tendon degeneration as seen on ultrasound. However, patients who received the FPL plate had significantly less of the tendon come in contact with the plate at 0° and 45° of wrist extension. The authors noted, however, that this difference may have been influenced by the fact that patients with the FPL-specific plate also had significantly lower volar tilt than patients with the standard locking plate. It is therefore not possible to determine whether it was the plate design or the bone position (or both) that led to these results.

It is also noteworthy that the two senior authors of this study work as consultants for the company that manufactures the plates that were evaluated. It is also important to note that because all the patients in this study were asymptomatic, further research is needed to determine the clinical importance of reduced tendon–plate contact area. We should temper our excitement about specially designed volar plates until we have more clinical data supporting their success in avoiding the problem for which they were designed.

Chad A. Krueger, MD
JBJS Deputy Editor for Social Media

Let’s Continue Improving Hip-Implant Longevity

In October 2017, JBJS published results from a 10-year randomized controlled trial by Devane et al. documenting the dramatic reduction in polyethylene wear in total hip arthroplasties (THAs) using highly cross-linked polyethylene (HXLPE). This followed decades of research documenting that wear debris was implicated in macrophage activity that was ultimately responsible for implant loosening. In the September 4, 2019 issue of The Journal, Hart and colleagues produce further evidence of the improved performance of HXLPE, this time showing revision rates among THA patients with osteonecrosis that rival the rates among patients with osteoarthritis.

In this matched cohort of 922 THAs performed from 1999 to 2007 that used an HXLPE bearing, the 15-year cumulative rate of revision was 6.6% among patients treated for osteonecrosis and 4.5% among patients treated for osteoarthritis (p = 0.09). There were no radiographic signs of component loosening in the entire cohort, and, despite a lower median preoperative Harris hip score (HHS) among patients with osteonecrosis, both groups had marked improvements in HHS score. These findings are especially noteworthy because patients with osteonecrosis typically undergo THA at an earlier age and have much higher functional demands than the typical 70- or 80-year-old osteoarthritis patient.

However, the 15-year revision rate—even with HXLPE—remains at 4.5% for osteoarthritis patients, which should provide impetus to continue our work identifying all possible factors and mechanisms that lead to THA revision. A partial list would include bearing-surface wear, reliability of implantation, biomechanics, biomaterials, and patient perception of postoperative pain. Also, in a subgroup analysis, Hart et al. found that the 15-year rate of any reoperation among osteonecrosis patients ranged from 0% for hips with radiation-induced osteonecrosis to 25% for hips with idiopathic osteonecrosis. These findings add to the list of factors for THA success that need further investigation.

The work list for improvements in THA will remain substantive for at least the next few decades, and we may never get to 0% revisions for all patients. But we have certainly demonstrated that our research can produce very worthwhile results.

Marc Swiontkowski, MD
JBJS Editor-in-Chief