Jean-Luc Clément1, Federico Solla2, Veronica Amorese2, Ioana Oborocianu2, Olivier Rosello2, Virginie Rampal2. 1. Department of Pediatric Orthopedics and Scoliosis Surgery, Hôpitaux pédiatriques de Nice CHU LENVAL, 57 Avenue de la Californie, Nice, France. clement.jluc@wanadoo.fr. 2. Department of Pediatric Orthopedics and Scoliosis Surgery, Hôpitaux pédiatriques de Nice CHU LENVAL, 57 Avenue de la Californie, Nice, France.
Abstract
PURPOSE: Distal thoracic kyphosis (DTK) equivalent to proximal lumbar lordosis (PLL) is the sum of pelvic tilt (PT) and the difference (Δ) between lumbar lordosis (LL) and pelvic incidence (PI): PLL = DTK = PT + Δ. With the assumption that proximal thoracic kyphosis (PTK) is similar to DTK, we propose the equation TK = 2(PT + LL - PI) to express the relationship between thoracic kyphosis (TK) and pelvic parameters. The objective of this work is to verify this relationship in a normal population. METHODS: Full spine radiographs of 100 adolescents and young adults (13 to 20 years old), free from vertebral pathology, were analyzed. Measurements included pelvic parameters, LL, PLL, DLL, TK, PTK, DTK and C7 global tilt. The measured global TK was compared with the theoretical TK calculated according to the formula TK = 2(PT + LL - PI). RESULTS: The difference between measured TK and calculated TK was + 2.3° and correlated with the C7 global tilt (r = 0.86). There was a significant linear regression between TK and PT + ∆ (p < 0.0001). Given radiographs' inter-rater reliability of 5° for angled measurements, the p value (0.047) between measured TK and calculated TK is statistically significant to support the hypothesis. CONCLUSION: This work validates the formula TK = 2(PT + LL - PI) which allows the calculation of global TK as a function of PT, LL and PI. This calculated TK can be used as a target for sagittal correction of adolescents with spine deformities. These slides can be retrieved under Electronic Supplementary Material.
PURPOSE: Distal thoracic kyphosis (DTK) equivalent to proximal lumbar lordosis (PLL) is the sum of pelvic tilt (PT) and the difference (Δ) between lumbar lordosis (LL) and pelvic incidence (PI): PLL = DTK = PT + Δ. With the assumption that proximal thoracic kyphosis (PTK) is similar to DTK, we propose the equation TK = 2(PT + LL - PI) to express the relationship between thoracic kyphosis (TK) and pelvic parameters. The objective of this work is to verify this relationship in a normal population. METHODS: Full spine radiographs of 100 adolescents and young adults (13 to 20 years old), free from vertebral pathology, were analyzed. Measurements included pelvic parameters, LL, PLL, DLL, TK, PTK, DTK and C7 global tilt. The measured global TK was compared with the theoretical TK calculated according to the formula TK = 2(PT + LL - PI). RESULTS: The difference between measured TK and calculated TK was + 2.3° and correlated with the C7 global tilt (r = 0.86). There was a significant linear regression between TK and PT + ∆ (p < 0.0001). Given radiographs' inter-rater reliability of 5° for angled measurements, the p value (0.047) between measured TK and calculated TK is statistically significant to support the hypothesis. CONCLUSION: This work validates the formula TK = 2(PT + LL - PI) which allows the calculation of global TK as a function of PT, LL and PI. This calculated TK can be used as a target for sagittal correction of adolescents with spine deformities. These slides can be retrieved under Electronic Supplementary Material.
Authors: Sebastien Pesenti; Jean-Luc Clément; Brice Ilharreborde; Christian Morin; Yann Philippe Charles; Henri François Parent; Philippe Violas; Marc Szadkowski; Louis Boissière; Jean-Luc Jouve; Federico Solla Journal: Eur Spine J Date: 2022-02-28 Impact factor: 3.134