Objective Our objectives were to use 3D computed tomography (CT) to define head-neck morphologic gender-specific and normative parameters in asymptomatic individuals and use the omega angle (Ω°) to provide quantification data on the location and radial extension of a cam deformity. Methods We prospectively included 350 individuals and evaluated 188 asymptomatic hips that underwent semiautomated CT analysis. Different thresholds of alpha angle (α°) were considered in order to analyze cam morphology and determine Ω°. We calculated overall and gender-specific parameters for imaging signs of cam morphology (Ω°and circumferential α°). Results The 95 % reference interval limits were beyond abnormal thresholds found in the literature for cam morphology. Specifically, α°at 3/1 o´clock were 46.9°/60.8°overall, 51.8°/ 65.4°for men and 45.7°/55.3°for women. Cam prevalence, magnitude, location, and epicenter were significantly gender different. Increasing α°correlated with higher Ω°, meaning that higher angles correspond to larger cam deformities.Conclusion Hip morphometry measurements in this cohort of asymptomatic individuals extended beyond current thresholds used for the clinical diagnosis of cam deformity, and α°was found to vary both by gender and measurement location. These results suggest that α°measurement is insufficient for the diagnosis of cam deformity. Enhanced morphometric evaluation, including 3D imaging and Ω°, may enable a more accurate diagnosis. Key Points • 95% reference interval limits of cam morphotype were beyond currently defined thresholds.• Current morphometric definitions for cam-type morphotype should be applied with care.• Cam prevalence, magnitude, location, and epicenter are significantly gender different.• Cam and alpha angle thresholds should be defined according to sex/location. • Quantitative 3D morphometric assessment allows thorough and reproducible FAI diagnosis and monitoring.

Background Surgical reconstruction of large bone defects with structural bone allografts can restore bone stock but is associated with complications such as nonunion, fracture, and infection. Vascularized reconstructive techniques may provide an alternative in the repair of critical bone defects; however, no studies specifically addressing the role of vascularized periosteal flaps in stimulating bone allograft revascularization and osseointegration have been reported.Questions/purposes (1) Does a vascularized periosteal flap increase the likelihood of union at the allograft-host junction in a critical-size defect femoral model in rats?(2) Does a vascularized periosteal flap promote revascularization of a critical-size defect structural bone allograft in a rat model? (3) What type of ossification occurs in connection with a vascularized periosteal flap?One of the authors certifies that he (MA) has received payments or benefits, during the study period, an amount of USD 10,000 to 100,000 from Societat Catalana de Cirurgia Ortopedica i Traumatologia (Barcelona, Spain). Clinical Orthopaedics and Related Research® neither advocates nor endorses the use of any treatment, drug, or device. Readers are encouraged to always seek additional information, including FDA approval status, of any drug or device before clinical use. Each author certifies that his or her institution approved the animal protocol for this investigation and that all investigations were conducted in conformity with ethical principles of research.