Is there a difference in the acromiohumeral distances measured on radiographic and magnetic resonance images of the same shoulder with a massive rotator cuff tear?

BACKGROUND: The purpose of our study was to compare the acromiohumeral distance (AHD) between radiographic and magnetic resonance images (MRIs) of the same shoulder with massive rotator cuff tears (MRCTs). METHODS: Thirty-four shoulders with MRCTs that had an MRI and radiograph of the same shoulder within an average of 40.3 days (range: 8-109 days) were identified. AHD was measured digitally on radiograph and MRI by 3 examiners. Shoulders were grouped into Hamada grades <3 (group 1) and Hamada grades ≥3 (group 2). RESULTS: The mean age was 66.4 years (range: 51-89). There were 19 men (59%). The Kappa for inter-rater reliability was 0.982 (95% confidence interval [CI] 0.975, 0.988) for radiographs and 0.88 (95% CI 0.75, 0.94) for MRI. There was a significant difference in the mean AHD of group 1 on radiograph vs. MRI (7.9 mm vs. 2.5 mm, respectively; P < .0001), but no difference in group 2 (1.8 mm vs. 2.2 mm, respectively; P = .45). There was no difference in AHD in group 1 between shoulders with Goutallier stage <3 (8.1 ± 1.9 mm) and those with Goutallier stage ≥3 (7.3 ± 2.1 mm) (P = .3479). There was no difference in AHD in group 2 between shoulders with Goutallier stage <3 (3.0 ± 0.1 mm) and those with Goutallier stage ≥3 (1.5 ± 1.0 mm) (P = .079). CONCLUSION: There is a significant difference in AHD measurements between radiograph and MRI of the same shoulder with MRCT in early Hamada grades. AHDs measured on radiograph and MRI should not be used interchangeably in early Hamada grades to assess outcomes of superior capsule reconstruction and similar procedures.

Impact of Computed Tomography on Operative Planning for Ankle Fractures Involving the Posterior Malleolus.

BACKGROUND: The purpose of this study was to (1) Determine the effect of computed tomography (CT) on identification of fractures involving the posterior malleolus, (2) determine its effect on operative indications, and (3) determine its effect on the overall operative plan. METHODS: Patients with ankle fractures involving the posterior malleolus were identified. Only injuries with complete preoperative plain radiographs and a CT scan were included. Spiral tibia fractures and pilon variants were excluded. The plain radiographs were deidentified, randomized, and presented to 3 orthopedic surgeons. They were asked 3 questions: (1) Is this fracture simple or complex? (2) Does the injury require direct visualization and reduction? and (3) How would you position the patient and approach the fracture? The same process was repeated for the CT scans. A total of 376 posterior malleolus injuries were identified and 25 met the inclusion criteria. RESULTS: A complex fracture pattern was identified on 44% of plain radiographs and 56% of CT scans. The surgeons chose to operate in 84% of cases based on plain radiographs and 92% of cases based on CT scan. The observers changed their operative approach or positioning 44% of the time after reviewing CT images. The interobserver and intraobserver correlation coefficients were moderate. CONCLUSION: The use of CT scan changed operative positioning and approach in 44% of cases. There was no significant change in characterization or operative indications when comparing plain radiographs to CT scan. CT scan may be a valuable tool in the management of ankle fractures involving the posterior malleolus. LEVEL OF EVIDENCE: Diagnostic Level III, comparative series.

Radiographic Detection of Marginal Impaction in Supination-Adduction Ankle Fractures.

BACKGROUND: The purpose of this study was to describe the incidence of plafond impaction in supination-adduction type II (SAD-II) ankle fractures and assess the accuracy of plain radiographs in detecting plafond impaction and predicting planned operative management compared to computed tomography (CT). METHODS: Patients with SAD-II ankle fractures were retrospectively identified. All SAD-II plain radiographs were reviewed (120 fractures) and compared to CT images (55 fractures). For each plain radiograph or CT scan, 3 orthopedic surgeons were asked the following questions: (1) Is there impaction of the tibial plafond? (2) Does the impaction require direct visualization and articular reduction? The incidence of plafond impaction and the preoperative plan were calculated separately for plain radiographs and CT scans. The accuracy of plain radiographs was calculated using responses from corresponding CT imaging as the gold standard. Change in preoperative management decisions after reviewing CT images was also calculated. RESULTS: In 120 SAD-II ankle fracture plain radiographs, marginal impaction of the plafond was visualized in 61% of fractures. The diagnosis of impaction using plain radiographs was correct in 84% of fractures when compared to CT imaging, resulting in a 91% positive predictive value (PPV) and a 55% negative predictive value (NPV). Plain radiographs were able to predict planned operative management after review of CT imaging with an 87% PPV and 75% NPV. CONCLUSION: The majority of SAD-II ankle fractures involved marginal impaction of the tibial plafond. Plain radiographs were accurate in diagnosing impaction when it was present, but were not accurate in ruling out impaction. In the presence of impaction, CT likely will not change planned operative management. LEVEL OF EVIDENCE: Level III, comparative series.