Increased subtalar rotational motion in patients with symptomatic ankle instability under load and stress conditions.

PURPOSE: Differentiating subtalar and ankle instability in the clinical setting is challenging. This study aims to analyze the rotational laxity of the subtalar joint bilaterally in patients with asymptomatic and symptomatic ankle instability under simulated load and stress-induced position of the subtalar joint. METHODS: A case-control study was conducted using an adjustable load device (ALD). Patients with chronic ankle instability and healthy volunteers were included. Each subject underwent a CT scan under mechanical stress and simulated weight-bearing conditions, maintaining maximum eversion and inversion hindfoot positions. The images were obtained in a single model, allowing calculations of the motion vector as well as the helical axis. The helical axis was defined by a rotation angle and a translation distance. RESULTS: A total of 72 feet were included in the study. Thirty-one patients with unilateral symptoms and five healthy controls were selected, defining two groups: symptomatic (n = 31) and asymptomatic (n = 41). An absolute difference of 4.6º (95%CI 2-11.1) rotation angle was found on the helical axis of the symptomatic vs. asymptomatic group (p = 0.001). No significant differences were detected in the translation distance (n.s.) between the groups. Additionally, a significant positive correlation was found between the rotation angle and translation distance through the helical axis in the asymptomatic group (r = 0.397, p = 0.027). CONCLUSION: Patients with chronic ankle instability suspected of having subtalar joint instability showed a wider subtalar range of laxity in terms of rotation about the helical axis. Furthermore, differences in kinematics between symptomatic and asymptomatic hindfeet was demonstrated when both feet were compared. LEVEL OF EVIDENCE: III.

Osteoma osteoide raquídeo recidivante en forma de osteoblastoma agresivo / Spinal osteoid osteoma recurring as an aggressive osteoblastoma

Presentamos el caso de un osteoma osteoide recurrente en forma de un osteoblastoma agresivo en columna lumbar. Un varón de 15 años acudió a nuestro servicio con una escoliosis dolorosa. El TC y la RM mostraron una tumoración formadora de hueso esclerótico de 7 mm compatible con un osteoma osteoide. Se realizó una ablación percutánea guiada por radiofrecuencia con remisión completa de la sintomatología. Seis meses después, dicha sintomatología recurrió. Se realizaron TC y RM que mostraron un crecimiento del nidus en la lámina L4 derecha, con un diámetro de 15 mm. Se realizó una resección marginal. La histología mostró un osteoblastoma epiteloide. Un años después, se realizaron nuevos estudios de imagen que mostraron una nueva recurrencia del tumor con rasgos agresivos e invasión del canal espinal. Se le realizó una cirugía de resección en bloque con estabilización de la columna lumbar. La histología confirmó el diagnóstico de osteoblastoma epiteloide

We report an uncommon case of osteoid osteoma recurring as an aggressive osteoblastoma of the spine. A 15-years-old male consulted in our department with long-term painful scoliosis. The CT-scans and MRI revealed a sclerotic bone forming tumor of 7 mm diameter consistent with a osteoid osteoma. A percutaneous radiofrequency ablation was performed with complete resolution of the symptoms. After 6 months, the symptoms recurred. A new CT and a MRI showed a growth of the nidus on the right L4 lamina, with a size of 15 mm. Therefore, a marginal resection by laminectomy of L4 was performed. Pathology confirmed an epithelioid osteoblastoma. A year later, subsequent imaging studies showed a new recurrence with aggressive features and invasion of the spinal canal. The patient then underwent an "in block surgery" needing concurrent stabilization of the spine. Histopathology confirmed the diagnosis of epithelioid osteblastoma

Spinal osteoid osteoma recurring as an aggressive osteoblastoma. / Osteoma osteoide raquídeo recidivante en forma de osteoblastoma agresivo.

We report an uncommon case of osteoid osteoma recurring as an aggressive osteoblastoma of the spine. A 15-years-old male consulted in our department with long-term painful scoliosis. The CT-scans and MRI revealed a sclerotic bone forming tumor of 7mm diameter consistent with a osteoid osteoma. A percutaneous radiofrequency ablation was performed with complete resolution of the symptoms. After 6 months, the symptoms recurred. A new CT and a MRI showed a growth of the nidus on the right L4 lamina, with a size of 15mm. Therefore, a marginal resection by laminectomy of L4 was performed. Pathology confirmed an epithelioid osteoblastoma. A year later, subsequent imaging studies showed a new recurrence with aggressive features and invasion of the spinal canal. The patient then underwent an "in block surgery" needing concurrent stabilization of the spine. Histopathology confirmed the diagnosis of epithelioid osteblastoma.