SYMPOSIA PAPER Published: 01 January 2003

Effect of Transverse Connector Design on Development of Late Operative Site Pain: Preliminary Clinical Findings


A leading cause for reoperation in patients with idiopathic scoliosis receiving posterior instrumentation and arthrodesis is Late Operative Site Pain (LOSP), with corrosion at the transverse connection site being a common observation. Clinically, a consecutive series of 55 adolescent idiopathic scoliosis patients with Isola Drop Entry Transverse Rod Connector's (DETCs) was compared with an earlier consecutive series of 97 having Isola Threaded Transverse Rod Connectors (TRCs). Both groups were less than 21 years of age, with TRC average follow-up 87 months and DETC 32 months. Kaplan-Meier survivorship analysis, utilizing implant removal for LOSP, was performed on both groups. Biomechanically, axial and torsional gripping capacity tests were performed on the DETC and TRC interconnections to the longitudinal rod. The axial gripping capacity was 1164 and 1191 N for the two DETC connector components versus 363 N for the TRC connector component. Correspondingly the torsional gripping capacity was 4.1 and 4.7 Nm compared to 1.3 Nm. The Kaplan-Meier probability of reoperation for LOSP by 60 months was 4.7% in the TRC group compared to 0% for DETC (p = 0.3993). Seven TRC patients underwent removal for LOSP versus zero for DETC (p = 0.0504). The stronger DETC interconnections possibly correlate with a decreased incidence of LOSP.

Author Information

Cook, S
University of Kansas Medical Center, Kansas City, KS
Asher, MA
University of Kansas Medical Center, Kansas City, KS
Carson, WL
University of Missouri-Columbia, Columbia, MO
Lai, SM
University of Kansas Medical Center, Kansas City, KS
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Developed by Committee: F04
Pages: 47–54
DOI: 10.1520/STP11131S
ISBN-EB: 978-0-8031-5480-3
ISBN-13: 978-0-8031-3463-8