Gadolinium Enhanced Mr Assessment of Proximal Fragment Vascularity in Nonunions after Scaphoid Fracture: Does It Predict the Outcome of Reconstructive Surgery?

Abstract

This study investigated whether the outcome of bone graft and internal fixation surgery for nonunion of scaphoid fractures could be predicted by gadolinium-enhanced MR assessments of proximal fragment vascularity. Sixteen established scaphoid fracture nonunions underwent gadolinium-enhanced MR scanning before surgical treatment with bone grafting and internal fixation. No relationship was found between MR enhancement and the outcome of surgery. Union was achieved in eight of the 12 nonunions with more than 50% enhancement, and three of the four with less than 50% enhancement, of the proximal pole. Furthermore, union was achieved in both of the nonunions which had less than 25% enhancement of the proximal pole. We conclude that enhanced MR assessments of the vascularity of the proximal fragment of a scaphoid fracture nonunion do not accurately predict the outcome of reconstructive surgery.

Is Dynamic Gadolinium Enhancement Needed in MR Imaging for the Preoperative Assessment of Scaphoidal Viability in Patients with Scaphoid Nonunion?

“…There are contradictory data about the accuracy of assessment of scaphoid viability with use of static contrast material-enhanced magnetic resonance (MR) imaging. Although some investigators have postulated good correlation between preoperative imaging fi ndings and postoperative union rates ( 9,10 ), others have demonstrated that MR imaging fi ndings are not predictive of reconstructive success ( 11,12 ).…”

“…In addition, the area of gadolinium uptake was judged on a semiquantitative scale ( 9,12 ), as follows: 4 = 80%-100% of fragment, 3 = 50%-79% of fragment, 2 = 20%-49% of fragment, and 1 = less than 20% of fragment. Finally, readers were asked to rate the viability of the proximal scaphoid pole with use of a fi ve-point Likert scale, where 1 = defi nitely viable, 2 = probably viable, 3 = indeterminate, 4 = probably nonviable, and 5 = defi nitely nonviable.…”

Comparison of computed tomographic and magnetic resonance imaging in fracture healing after spinal injury

“…This is similar to our findings with pedicle screws in spinal fractures. Singh et al 12 used gadolinium-enhanced fat-suppressed sequences in the assessment of scaphoid fractures, particularly looking at vascularity and avascular necrosis; the additional benefit of gadolinium is not established but may be an area for further investigation in spinal fractures. The change in signal characteristics with time in vertebral compression fractures has been described by Sung et al 13 This shows T1-w hypointensity and T2-w hyperintensity in compression fractures o1 month old with signal returning to normal by 3 months.…”

Accuracy of enhanced and unenhanced MRI in diagnosing scaphoid proximal pole avascular necrosis and predicting surgical outcome

“…Some authors have demonstrated a strong correlation with the vascular status at surgery [6][7][8][9][10]; however, others have concluded the opposite [11]. Disparate conclusions have also been reported regarding the usefulness of gadolinium-enhanced MRI to evaluate proximal pole vascularity, even when dynamic imaging was used [11][12][13]. The issue is further complicated by a report describing the Bapparent increased contrast pattern^in 6 of 13 patients with surgically proven avascular proximal poles [14].…”

“…The issue is further complicated by a report describing the Bapparent increased contrast pattern^in 6 of 13 patients with surgically proven avascular proximal poles [14]. To our knowledge, only four articles have attempted to correlate surgical outcome and the preoperative MRI findings, two analyzing nonvascularized bone grafts, one analyzing vascularized bone grafts, and one analyzing both vascularized and nonvascularized grafts, [11,12,15,16].…”