The role of skeletal sonography in limb lengthening procedures

Eleven patients (8 males, 3 females) undergoing limb-lengthening procedures were subjected to weekly conventional radiography along with fortnightly skeletal sonography of the distraction site, to assess the rate of new bone production and complications. The radiographs were assessed for: (i) distance between the distracted bone ends, (ii) presence of new bone formation at the distraction site, (iii) regeneration of the cortical outline and (iv) overlaying soft tissue abnormality. The sonographs were assessed for: (i) distance between the distracted bone ends, (ii) rate of new bone formation, (iii) density of the new bone produced, (iv) integrity and continuity of the cortical outline and (v) overlaying soft tissue abnormality. Our results indicate the superiority of sonography over conventional radiographs in: (i) detecting early new bone formation, (ii) establishing cortical and medullary canal remodelling, (iii) detecting soft tissue complications at the distraction site and (iv) determining the presence of fluid collection at the distraction site, in patients with delayed consolidation. Conventional radiographs were more accurate in determining the distance between the two distracted bone ends, and thus the degree of distraction achieved. Ideal assessments of events at the distraction site can be achieved by a combined assessment of conventional radiotherapy and skeletal sonography.