title: A new classification of peri-articular heterotopic ossification of the hip associated with neurological injury: 3D CT scan assessment and intra-operative findings.
abstract: In this paper we propose a new classification of neurogenic peri-articular heterotopic ossification (HO) of the hip based on three-dimensional (3D) CT, with the aim of improving pre-operative planning for its excision. A total of 55 patients (73 hips) with clinically significant HO after either traumatic brain or spinal cord injury were assessed by 3D-CT scanning, and the results compared with the intra-operative findings. At operation, the gross pathological anatomy of the HO as identified by 3D-CT imaging was confirmed as affecting the peri-articular hip muscles to a greater or lesser extent. We identified seven patterns of involvement: four basic (anterior, medial, posterior and lateral) and three mixed (anteromedial, posterolateral and circumferential). Excellent intra- and inter-observer agreement, with kappa values > 0.8, confirmed the reproducibility of the classification system. We describe the different surgical approaches used to excise the HO which were guided by the 3D-CT findings. Resection was always successful. 3D-CT imaging, complemented in some cases by angiography, allows the surgeon to define the 3D anatomy of the HO accurately and to plan its surgical excision with precision.
authors.affiliation: University of Tor Vergata, Viale Oxford 81 00133 Rome, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Arduini
authors.affiliation: University of Tor Vergata, Viale Oxford 81 00133 Rome, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Mancini
authors.affiliation: University of Tor Vergata, Viale Oxford 81 00133 Rome, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Farsetti
authors.affiliation: University of Tor Vergata, Viale Oxford 81 00133 Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Piperno
authors.affiliation: University of Tor Vergata, Viale Oxford 81 00133 Rome, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Ippolito
mesh_terms: D000328:Adult; D001930:Brain Injuries / Q000150:complications; D005260:Female; D006621:Hip Joint; D006801:Humans; D021621:Imaging, Three-Dimensional; D007432:Intraoperative Period; D007592:Joint Diseases / Q000145:classification* / Q000000981:diagnostic imaging* / Q000209:etiology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009999:Ossification, Heterotopic / Q000145:classification* / Q000000981:diagnostic imaging* / Q000209:etiology / Q000601:surgery; D013119:Spinal Cord Injuries / Q000150:complications; D014057:Tomography, X-Ray Computed; D055815:Young Adult
keywords: Heterotopic ossification; Hip; Neurological injury; Surgical approach