General Session: Adult Spinal Deformity - Hall F

Presented by: P. Passias


P. Passias(1), S. Horn(1), G. Poorman(1), A. Daniels(2), D.K. Hamilton(3), H.J. Kim(4), C. Bortz(1), F. Segreto(1), D. Ge(1), N. Frangella(1), B. Diebo(5), D. Sciubba(6), J. Smith(7), B. Neuman(6), C. Shaffrey(7), R. Lafage(4), V. Lafage(4), C. Ames(8), R. Hart(9), G. Mundis((1)0), R. Eastlack((1)0), F. Schwab(4), International Spine Study Group

(1) New York University Langone Orthopedic Hospital, Division of Spinal Surgery, New York, NY, United States
(2) Brown University Alpert Medical School, Department of Orthopaedic Surgery, Providence, RI, United States
(3) University of Pittsburgh, Department of Neurologic Surgery, Pittsburgh, PA, United States
(4) Hospital for Special Surgery, Department of Orthopaedic Surgery, New York, NY, United States
(5) SUNY Downstate Medical Center, Department of Orthopaedic Surgery, Brooklyn, NY, United States
(6) Johns Hopkins University, Department of Neurosurgery, Baltimore, MD, United States
(7) University of Virginia, Department of Neurosurgery, Charlottesville, VA, United States
(8) University of California San Francisco, Department of Neurological Surgery, San Francisco, CA, United States
(9) Swedish Neuroscience Institute, Department of Orthopaedic Surgery, Seattle, WA, United States
((1) 0) Scripps, Department of Orthopaedics, La Jolla, CA, United States


Introduction: CD development secondary to PJK was recently documented in adult spinal deformity patients after surgical correction for thoracolumbar ASD. This study aims to analyze surgical management of patients with CD secondary to proximal junctional kyphosis(PJK) versus patients with primary CD.

Methods: Retrospective review of multicenter cervical deformity(CD) database. CD defined as at least one of the following:C2-C7 coronal Cobb>10°, cervical lordosis(CL)>10°, cervical sagittal vertical axis(cSVA)>4cm, CBVA>25°. Patients were grouped into those with PJK(UIV+2< -10°) prior to cervical surgery versus who don't(Non-PJK). Independent t-tests and chi-squared tests compared radiographic, clinical, and surgical metrics between PJK and non-PJK groups.

Results: Of 123 eligible CD patients, 26(21.1%) had radiographic PJK prior to cervical surgery. There were no significant differences in age, gender, BMI, CCI, history of prior cervical surgery, or baseline HRQLs(p>0.05). PJK patients had significantly greater T2-T12 thoracic kyphosis(-58.8° vs -45.0°,p=0.002), cSVA(49.1mm vs 38.9mm,p=0.020), T1 Slope(42.6° vs 28.4°,p< 0.001), TS-CL(44.1° vs 35.6°,p=0.048), C2-T3 SVA(98.8mm vs 75.8mm,p=0.015), C2 Slope(45.4° vs 36.0°,p=0.043), and CTPA(6.4° vs 4.6°,p=0.005). Comparing their surgeries, the PJK group had significantly more levels fused(10.7 vs 7.4,p=0.01). There was significantly greater blood loss in PJK patients(1158±1063vs 738± 793cc,p=0.028); operative time, surgical approach, and BMP-2 use were similar(all p>0.05). PJK patients experienced higher rates of complications 30 and 90 days post-operatively(23.1% vs. 5.2%,p=0.004; 30.8% vs. 19.6%,p=0.026), and more instrumentation failure 30 days postoperatively(7.8% vs. 1.0%,p=0.004). However, there were no significant differences in HRQLs between PJK and non-PJK patients at 3 months, 6 months, or 1 year(all p>0.05).

Conclusions: The prevalence of pre-operative PJK was 21.1% among CD cases in this series. Patients with cervical deformity secondary to PJK had worse baseline CD, despite no differences in HRQL or demographics. Surgical correction of CD associated with PJK required more invasive surgery and had higher complication rates than non-PJK patients, despite achieving similar clinical outcomes.