Common predictors successfully determine distal radius fracture outcomes

LaFontaine’s criteria, McQueen’s equation and volar hook predict change in radiographic parameters.

Issue: November 2012

CHICAGO — Researchers could predict ulnar variance, radial height and radial inclination using LaFontaine criteria and McQueen’s equation, and found that hooking the volar cortex is an important predictor of final volar tilt, according to a recently presented study.

Perspective from Charles S. Day, MD

“Both LaFontaine criteria and the McQueen equation are effective in predicting radial height and inclination. However, volar tilt and the change in ulnar tilt were predicted by hooking the volar cortex and dorsal comminution” Paul Tornetta, III, MD, told Orthopedics Today. “These findings can be used to help guide clinical practice as to who may require surgery.” The study findings were presented by Joey A. LaMartina II, MD, at the American Society for Surgery of the Hand Annual Meeting.

The investigators sought to determine the predictors of alignment for distal fractures treated definitively with closed reduction and casting. Because clinical outcomes have been correlated with alignment, they tested two previously reported predictors of alignment — the LaFontaine criteria and McQueen’s equation, according to Tornetta, who noted these “are the most commonly cited predictors of success or failure.”

The researchers also aimed to determine whether volar hook would predict volar tilt and alignment.

Tornetta and colleagues retrospectively studied 168 patients with distal radius fractures treated nonoperatively and excluded patients with dorsal tilt less than 10° on presentation and those treated operatively. They measured dorsal tilt, radial height and inclination, ulnar variance, and the presence of carpal malalignment on the initial reduction and final radiographs. The investigators then followed the patients through final fracture union at an average of 3 months.

They determined the predictive value of McQueen’s equation and LaFontaine’s criteria for each parameter, and conducted univariate analyses for each score and for volar hook, as well as for gender and age. In addition, they conducted a multivariate analysis of the factors found important in the univariate analysis: age, volar hook, dorsal comminution, intra-articular fracture and gender, and compared them to radiographic outcomes and changes during healing, according to the study abstract.

This 74-year-old man met all five Lafontaine criteria with a McQueen’s percentage of approximately 82%. This patient has lost a fair amount of radial height.

Images: Tornetta P

The researchers validated McQueen’s equation and LaFontaine’s criteria for ulnar variance, radial height and radial inclination, and found volar hook predicted volar tilt. They found that older age correlated with greater change in ulnar variance, radial height and radial inclination.

Furthermore, the authors provided a quantitative definition for “dorsal comminution,” which Tornetta said “has never been done before.” They defined dorsal comminution as at least 5 mm dorsal cortical bone that was damaged for greater than one third the height of the distal radius.

“Dorsal comminution is listed in most predictive algorithms, but no one has ever defined it. This specific definition can be used going forward to make the evaluation more consistent,” Tornetta said. – by Renee Blisard Buddle

Reference:

LaMartina J II. Paper #35. Presented at: American Society for Surgery of the Hand Annual Meeting; Sept. 6-8, 2012; Chicago.

For more information:

Paul Tornetta, III, MD, can be reached at Boston Medical Center, Department of Orthopedics, Dowling 2 North, 850 Harrison, Boston, MA 02118; email: ptornetta@gmail.com.

Disclosure: Tornetta owns intellectual property with Smith & Nephew.

Perspective

Charles S. Day, MD

This was a retrospective cohort study examining 275 displaced distal radius fractures over the last 6 years in a single level-1 trauma center. Of the 275 patients, they had excluded those that had subsequent surgery and sought to validate LaFontaine’s criteria as well as McQueen’s equation on the final radiographic outcome of these patients. Using univariate and multivariate analyses, [investigators] were able to validate McQueen’s and LaFontaine’s criteria for ulnar variance, radial height and inclination, however not for dorsal tilt or for carpal malalignment. In addition they found that hooking the volar cortex was the most important predictor at maintaining adequate dorsal tilt. I have two concerns. Number one: why would they exclude the 100 patients that subsequently underwent operative treatment and lost reduction as part of the initial reduction maneuver? And number two, looking at hooking the volar cortex as a criterion, that to me looked like it was initial adequate reduction of the fracture in the first place. And thus, both LaFontaine’s criteria and McQueen’s equation really assumes initial adequate reduction as a predictor for future outcomes.

Charles S. Day, MD

Beth Israel Deaconess Medical Center

Lexington, Mass.

Disclosures: Day received research or institutional support from Boston Scientific and Small Bone Innovations and has a consulting arrangement with Medtronic.