Details

Autor(en) / Beteiligte

• Han, Sang Hyun, M.D
• Hyun, Seung-Jae, M.D., Ph.D
• Kim, Ki-Jeong, M.D., Ph.D
• Jahng, Tae-Ahn, M.D., Ph.D
• Lee, Subum, M.D
• Rhim, Seung-Chul, M.D., PhD

Titel

Rod stiffness as a risk factor for proximal junctional kyphosis after adult spinal deformity surgery: Comparative study between cobalt chrome multiple-rod constructs and titanium alloy two-rod constructs

Ist Teil von

• The spine journal, 2017-07, Vol.17 (7), p.962-968

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2017

Quelle

MEDLINE

Beschreibungen/Notizen

• Abstract Background Context Little is known about the effect of rod stiffness as a risk factor for proximal junctional kyphosis (PJK) after adult spinal deformity (ASD) surgery. Purpose The aim of this study was to compare radiographical outcomes after the use of cobalt chrome multiple-rod constructs (CoCr MRC) and titanium alloy two-rod constructs (Ti TRC) for the ASD) surgery with minimum 1-year follow-up. Study Design Retrospective case-control study in two institutes. Patients Sample We included 54 patients who underwent ASD surgery with fusion to sacrum in two academic institutes between 2002 and 2015. Outcome Measures Radiographical outcomes were measured on the standing lateral radiographs before surgery, 1 month postoperatively and at ultimate follow-up. They were composed of pre-and postoperative sagittal vertical axis (SVA), pre-and postoperative lumbar lordosis (LL), pre-and postoperative thoracic kyphosis (TK)+ LL+ pelvic incidence (PI), pre-and postoperative PI minus LL, level of upper instrumented level (UIV), evaluation of fusion after surgery, the presence of proximal junctional kyphosis (PJK), and the occurrence of rod fracture. Methods We reviewed the medical records of 54 patients who underwent ASD surgery. Of these, 20 patients had CoCr MRC and 34 patients had Ti TRC. Baseline data and radiographical measurements were compared between two groups. . The Mann-Whitney U test, the chi square test, and the Fisher exact test were used to compare outcomes between groups. Results Patients of the groups were similar in terms of age, gender, diagnosis, number of three column osteotomy, levels fused, bone mineral density, preoperative TK, pre-and postoperative TK+LL+PI, SVA difference, LL change, pre-and postoperative PI minus LL and the location of UIV (upper-or lower thoracic). However, there were significant differences in the occurrence of PJK and rod breakage (PJK : CoCr MRC: 12 (60%) vs Ti TRC: 9 (26.5%), P =0.015; the occurrence of rod breakage : CoCr MRC: 0 (0%) vs Ti TRC: 11 (32.4%), P =0.004). The time of PJK was less than 12 months after surgery in CoCr MRC group. However, 55.5% (5/9) of PJK developed over 12 months after surgery in Ti TRC group. Conclusions Increasing the rod stiffness by use of CoCr and MRC can prevent rod breakage, however, adversely affects the occurrence and the time of PJK.