Global Spine Journal - 2026-05-08 - Journal Article
Reduced Preoperative Cervical Spine Flexion-Extension Range of Motion Is Associated With the Development of Upper Thoracic Proximal Junction Kyphosis in Adult Spinal Deformity Patients.
Scheer JK, Hassan FM, Hung CW, Shi T, Lee NJ, Roth SG, Tuchman A, Walker CT, Lombardi JM, Sardar ZM, Lehman RA, Lenke LG
Topics
Key Takeaway
Preoperative cervical flexion <22.8° and total cervical ROM <48.2° are independent risk factors for symptomatic proximal junction kyphosis/failure after adult spinal deformity correction with UIV in the upper thoracic spine.
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Summary
This study evaluated whether preoperative cervical flexion-extension ROM predicts symptomatic PJK/PJF in ASD patients fused to the pelvis with UIV at T1–T4. Of 151 patients, 12.6% developed S-PJK/PJF; this group had significantly lower cervical flexion (7.7° vs 19.5° No-PJK, P=0.0029) and total ROM (39.2° vs 52.8° No-PJK, P=0.0085). Multivariable analysis identified cervical flexion <22.8° and ROM <48.2° as independent risk factors, with all S-PJK/PJF patients falling below the flexion threshold.
Key Limitation
The minimum 1-year follow-up is insufficient to capture the full incidence of PJK/PJF, which can develop beyond 2 years postoperatively, likely underestimating the true event rate.
Original Abstract
Study DesignRetrospective , Single-center.ObjectiveTo evaluate preoperative cervical range-of-motion via cervical flexion-extension radiographs and its relation to the development of PJK/PJF following ASD correction in patients with a UIV in the upper thoracic spine.MethodsPatients with an UIV between T1-T4, preoperative cervical flexion/extension radiographs and instrumented to the pelvis, and minimum 1yr follow-up were included. Cervical measurements included range-of-motion (ROM), flexion, extension and cervical SVA (cSVA). Patients were stratified into 3 groups: No-PJK, asymptomatic PJK (A-PJK) and symptomatic PJK including PJF (S-PJK/PJF).Results151 patients were included: Mean age 59.6 ± 8.0 yrs, BMI of 25.1 ± 4.5, 88.7% (n = 134) were female. PJK status: No PJK = 111 (73.5%) patients, A-PJK = 21 (13.9%), S-PJK/PJF = 19 (12.6%). S-PJK/PJF patients, however, were more likely to be diagnosed with osteopenia/osteoporosis(S-PJK/PJF: 68.4% vs
A-PJK
23.8% vs No
PJK
52.3%, P = 0.0138). S-PJK/PJF patients had significantly less cervical flexion (No
PJK
19.5 ± 14.2 vs
A-PJK
19.9 ± 10.9 vs
S-PJK/PJF
7.7 ± 11.9, P = 0.0029) and ROM than the other groups (No
PJK
52.8 ± 17.7 vs
A-PJK
53.1 ± 14.5 vs
S-PJK/PJF
39.2 ± 17.9, P = 0.0085). On multivariable models for the development of S-PJK/PJF, reduced baseline cervical flexion and ROM were independent risk factors yielding threshold values of 22.8° and 48.2°, respectively.ConclusionMultivariable models for the development of S-PJK/PJF demonstrated that reduced baseline cervical ROM and flexion were independent risk factors yielding threshold values of 48.2° and 22.8°, respectively. All of S-PJK/PJF patients had preop flexion <22.8°. Flexion-extension radiographs provide a quick and easy option at a relatively low cost to offer additional information that may aid in surgical planning and shared decision making with the patient regarding potential outcomes.