STUDY DESIGN: Retrospective case series. OBJECTIVE: To determine the prevalence of proximal junctional sagittal plane flexion increase after posterior instrumentation and arthrodesis. SUMMARY OF BACKGROUND DATA: Increased flexion proximal to the junction of the instrumented and fused spinal region with the adjacent mobile spine seems to be a relatively recent observation, may be increasing, and is occasionally problematic. METHODS: The proximal junctional sagittal angulation 2 motion segments above the upper end instrumentation levels was measured on lateral standing preoperative and follow-up radiographs. RESULTS: One hundred seventy-four of 208 consecutive patients (84%) at an average radiograph follow-up of 4.9 +/- 2.73 years had increased proximal junctional flexion in 9.2%. The preoperative junctional measurements were normal for both normal and increased flexion groups. At follow-up, proximal junctional flexion had increased significantly more in the increased flexion group (2.1 degrees vs. 14.1 degrees , P < 0.0001). None of the possible risk factors studied, including demographic comparisons, Lenke classification (including lumbar and sagittal modifiers), end-instrumented vertebrae, end vertebra anchor configurations, surgical sequence, additional anterior surgery, rib osteotomies, and instrumentation length, were significantly associated with increased proximal junctional flexion at follow-up. Lenke 6 curves were at marginal risk of increased proximal junctional flexion (P = 0.0108). There were no differences between the groups in total Scoliosis Research Society-22r scores at an average follow-up of 8.0 +/- 3.74 years. No patient had additional surgery related to increased proximal junctional flexion. CONCLUSION: The prevalence of increased proximal junctional flexion was 9.2%. No significant risk factors were identified. Total Scoliosis Research Society-22r scores were similar for groups with normal and increased proximal junctional flexion at follow-up.
STUDY DESIGN: Retrospective case series. OBJECTIVE: To determine the prevalence of proximal junctional sagittal plane flexion increase after posterior instrumentation and arthrodesis. SUMMARY OF BACKGROUND DATA: Increased flexion proximal to the junction of the instrumented and fused spinal region with the adjacent mobile spine seems to be a relatively recent observation, may be increasing, and is occasionally problematic. METHODS: The proximal junctional sagittal angulation 2 motion segments above the upper end instrumentation levels was measured on lateral standing preoperative and follow-up radiographs. RESULTS: One hundred seventy-four of 208 consecutive patients (84%) at an average radiograph follow-up of 4.9 +/- 2.73 years had increased proximal junctional flexion in 9.2%. The preoperative junctional measurements were normal for both normal and increased flexion groups. At follow-up, proximal junctional flexion had increased significantly more in the increased flexion group (2.1 degrees vs. 14.1 degrees , P < 0.0001). None of the possible risk factors studied, including demographic comparisons, Lenke classification (including lumbar and sagittal modifiers), end-instrumented vertebrae, end vertebra anchor configurations, surgical sequence, additional anterior surgery, rib osteotomies, and instrumentation length, were significantly associated with increased proximal junctional flexion at follow-up. Lenke 6 curves were at marginal risk of increased proximal junctional flexion (P = 0.0108). There were no differences between the groups in total Scoliosis Research Society-22r scores at an average follow-up of 8.0 +/- 3.74 years. No patient had additional surgery related to increased proximal junctional flexion. CONCLUSION: The prevalence of increased proximal junctional flexion was 9.2%. No significant risk factors were identified. Total Scoliosis Research Society-22r scores were similar for groups with normal and increased proximal junctional flexion at follow-up.
Authors: Han Jo Kim; Mitsuru Yagi; Joseph Nyugen; Matthew E Cunningham; Oheneba Boachie-Adjei Journal: Clin Orthop Relat Res Date: 2012-06 Impact factor: 4.176
Authors: M Yagi; H Ohne; T Konomi; K Fujiyoshi; S Kaneko; T Komiyama; M Takemitsu; Y Yato; M Machida; T Asazuma Journal: Osteoporos Int Date: 2016-06-24 Impact factor: 4.507