Reliability of Bigliani’s Classification using Magnetic Resonance Imaging for Determination of Acromial Morphology

@#Introduction: Bigliani classification is used for determination of acromial morphology, but poor interobserver reliability has been reported on conventional radiographs. This study aims to assess inter- and intraobserver reliability using magnetic resonance imaging (MRI). Materials and methods: Forty consecutive patients diagnosed with subacromial impingement syndrome were included to study. All subjects underwent standard shoulder MRI scan and acromial shape was evaluated by nine observers of different level of expertise (three attending surgeons, three senior orthopaedic residents and three radiologists). A second set of evaluation was performed in order to assess intra-observer reproducibility. Kappa (κ) coefficient analyses both for interobserver reliability and intra-observer reproducibility were then performed. Results: Overall inter-observer agreement among nine observers was fair (κ=0.323). κ values for all 4 individual types ranged from 0.234 to 0.720 with highest agreement for type 4 and lowest agreement for type 3. Second evaluation did not result with an increase of inter-observer agreement (κ=0.338, fair). The κ coefficients for intra-observer reproducibility of nine observers ranged from 0.496 to 0.867. Overall intra-observer reproducibility was substantial. Comparison of inter- and intra-observer reliability among three groups showed no significant difference (p=0.92 and 0.22, respectively). Conclusion: Results showed that MRI did not show superior reliability compared to conventional radiographs. Moreover, inter- and intra-observer agreement did not differ between observers of different level of expertise. Findings of present study suggest that despite a sophisticated imaging modality like MRI, Bigliani’s classification apparently lacks accuracy and additional criteria, or different assessment methods are required to assess acromial morphology for clinical guidance.

Aneurysmal Bone Cyst after Femoral Derotational Osteotomy: A Case Report

@#Aneurysmal bone cysts rather than local aggressive lesions of the bone which may arise in any part of the axial or appendicular skeleton. Although several theories are available in the literature, the pathogenesis is still conflicting. We report an exceptional case of an aneurysmal bone cyst in the distal femur of a female cerebral palsy patient who underwent bilateral distal femoral derotational osteotomy and plate-screw fixation operations when she was 11 years old. Twenty-four months after the operation, radiographs showed a cystic lesion in the distal portion of the right femur around the osteotomy site. The diagnosis of Aneurysmal Bone Cyst (ABC) was made and the lesion was treated by curettage with cement application. After 36 months of follow-up, there was no recurrence. This is the first case reported in literature which raises the possibility that an osteotomy could be a cause in the development of an aneurysmal bone cyst.