Clinical Significance of the Radiolucent Zone Around the Pedicle Screws in the Lumbar Degenerative Disease / 대한척추외과학회지

STUDY DESIGN: A retrospective study. OBJECTIVE: To analyze the clinical significance of the radiolucent zones surrounding pedicle screws. SUMMARY OF LITERATURE REVIEW: Clear zones have been suggested in pseudoarthrosis and a loss of fixation. However, few reports have clearly described the long-term course and clinical significance of clear zones. MATERIALS AND METHODS: The clear zones were evaluated in 399 patients with pedicle screw fixation after 6 months, 1 year, 2 years and 3 years. The patient was considered to be clear zone positive when 1 mm or greater circumferential lucency was confirmed around a screw on film from 2 or more directions. The time-course of the clear zones was examined with regard to age, number of levels fused, bone union, fusion method and reoperation. RESULTS: After 6 months, clear zones were observed in 124 patients (31.1%) but the clear zone-positive rate decreased with time. Clear zones were observed in 89 patients(22.3%), 44 patients(11.0%) and 41 patients(10.3%) after 1 year, 2 years and 3 years, respectively. No new clear zones had developed after 6 months. At the final follow-up, pseudoarthrosis was observed in 12 patients(3.0%). Among them, 11 were clear zone-positive and 1 was clear zone-negative. There was a statistically significant relationship between the clear zone-positive rate and multi-levels, older age and nonunion during following up. In addition, there was a relatively lower clear zone-positive rate in posterolateral fusion combined with posterior lumbar interbody fusion than only posterolateral fusion. However, the difference between them was not statistically significant. CONCLUSION: The presence of clear zones does not always mean pseudoarthrosis but clear zones persisting for more than 2 years after surgery have a higher rate of pseudoarthrosis.

Costoclavicular Syndrome: A Case Report

Costoclavicular syndrome is one of the four syndromes of thoracic outlet syndrome in which have similiar symptoms, and may result from cervical and thoracic scoliosis, formation of excessive callus or nonunion after fractures of clavicle or first rib. Conservative treatment may be offered. Surgical treatment includes scalenectomy with supraclavicular approach, transaxillary first rib resection with scalenectomy and correction of clavicular abnormality. The purpose of this paper is to evaluate the result of surgical intervention in costoclavicular syndrome of a 38-year old man with clavicular nonunion after an operation.