Tetracycline labeling as an aid to complete excision of partial physeal arrest: a rabbit model

We determined whether ultraviolet (UV) visualization of tetracycline-labeled bone allows more complete excision of experimentally created physeal arrests while minimizing required bone resection. Lateral distal femoral growth arrests were surgically created bilaterally in eight 6-week-old New Zealand white rabbits, given 3 daily oxytetracycline doses (10 mg/kg); the animals were killed 6 weeks postoperatively. Femurs were excised and dissected free of soft tissue. Ten of 16 operated femurs randomized into two groups had consistent deformity. In group I, arrest was excised with a high-speed burr without, and, in group II, with ultraviolet visualization. In group II, metaphyseal bone and calcified arrest glowed brightly, contrasting well with the epiphyseal plate. All excised specimens were examined under x 9 magnification to assess remaining bone bridges. Excision defects were filled with modeling clay, which was then removed and weighed. Thorough excision was confirmed in each specimen. Resection was easier and less bone usually was resected in the UV group (difference not statistically significant). This technique would best be used in resection of arrests involving small physes such as the distal radius, in which maximal visualization and minimal resection are essential to preserve all possible growth potential. Tetracycline labeling and intraoperative UV visualization of fluorescence allows thorough excision of partial physeal arrest while minimizing required bone resection.