In this post, JBJS Deputy Editor for Social Media Dr. Matt Schmitz reflects on 2 recent studies of fracture fixation and the continued quest to improve outcomes.
Proximal humeral fragility fractures can sometimes be “bad actors” in orthopaedic surgery, with osteoporotic bone challenging the ability to maintain fixation for healing. Previous research on these types of fractures has focused on medial calcar support to help provide stability for fixation. Little is known, however, about the role that the lateral wall of the greater tuberosity (GT) and its potential comminution may play in stability following fixation.
In the current issue of JBJS, Kim et al. assessed the biomechanical stability of osteoporotic proximal humeral fractures fixed with a locking plate to evaluate the impact of GT lateral wall comminution: Lateral Wall Integrity of the Greater Tuberosity Is Important for the Stability of Osteoporotic Proximal Humeral Fractures After Plate Fixation
The investigators used 10 matched pairs of cadaveric humeri to compare fractures of the surgical neck alone and fractures of the surgical neck with GT lateral wall comminution (5 mm of the GT lateral wall was removed to simulate severe comminution).
They found that comminution of the GT lateral wall significantly compromised stability in various tests, including torsional stiffness, axial compression stiffness, and varus bending stiffness. They also found that the mean single load to failure in varus bending was 62% lower for the group with a comminuted GT lateral wall vs the group with surgical neck fracture alone.
The study highlights the importance of the integrity of the GT lateral wall in stabilizing osteoporotic proximal humeral fractures fixed with a plate, even with medial calcar support. The authors discuss potential clinical implications of their findings as well as limitations of the study. Among these: the difference between cadaveric studies—which are important to the literature and may help fuel further research—and results in an in vivo setting.
On that front, a new multicenter randomized trial by Lefaivre et al. examines fixation for another type of challenging fracture, distal femoral fractures. Far cortical locking (FCL) constructs have been proposed to be superior to standard locking plates, with promising results in biomechanical studies and animal models. Lefaivre et al. conducted a comparative effectiveness clinical trial to assess whether FCLs achieve better fracture healing than the use of traditional locking bridge plates for acute, displaced fractures of the distal femur.
In the study, performed across 16 centers, the investigators found similar radiographic and clinical outcomes between the groups, with no clear advantage to the FCL construct. A commentary by Marshall and Marshall and a video summary of the findings accompany the study, now available at JBJS.org:
As scientists and researchers, it is critical that we continue to seek improvements leading to better outcomes for our patients. Biomechanical studies can help us hone our research questions and potential hypotheses. And it is incumbent upon us to take in vitro revelations with their potential to change clinical practice and rigorously test them in the in vivo setting. Not all findings from the lab may necessarily translate into superior outcomes, but the pursuit may reveal viable alternatives for challenging scenarios in musculoskeletal care.
Read the study by Kim et al.: Lateral Wall Integrity of the Greater Tuberosity Is Important for the Stability of Osteoporotic Proximal Humeral Fractures After Plate Fixation
Read the study by Lefaivre et al. and access the video abstract: Far Cortical Locking Versus Standard Constructs for Locked Plate Fixation in the Treatment of Acute, Displaced Fractures of the Distal Femur. A Multicenter Randomized Trial.
Commentary by Marshall and Marshall: Do the Types of Screws Used in Treating Distal Femoral Fractures Make a Difference?
Matthew R. Schmitz, MD
JBJS Deputy Editor for Social Media
