Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2016 Jun;41(12):E742-E750.
doi: 10.1097/BRS.0000000000001374.

Selecting the Last "Substantially" Touching Vertebra as Lowest Instrumented Vertebra in Lenke Type 1A Curve: Radiographic Outcomes With a Minimum of 2-year Follow-Up

Xiaodong Qin  1 , Weixiang Sun, Leilei Xu, Zhen Liu, Yong Qiu, Zezhang Zhu
Affiliations

Selecting the Last "Substantially" Touching Vertebra as Lowest Instrumented Vertebra in Lenke Type 1A Curve: Radiographic Outcomes With a Minimum of 2-year Follow-Up

Xiaodong Qin et al. Spine (Phila Pa 1976). 2016 Jun.

Abstract

Study design: Retrospective study.

Objective: To compare the long-term outcomes of correction surgery for Lenke 1A scoliosis patients among those with non-Substantially Touched Vertebra (nSTV), nSTV+1, or STV selected as lowest instrumented vertebra (LIV).

Summary of background data: Previous studies have documented good outcomes when last touching vertebra (LTV) was selected as LIV; however, it is sometimes confusing to determine the proper LTV when central sacral vertical line (CSVL) slightly touches the vertebra.

Methods: A total of 104 patients were included in the study with a minimum of 2-year follow-up after selective posterior thoracic instrumentation. STV was defined as the LTV where CSVL was between the pedicles or touching the pedicle. nSTV was defined as the LTV where CSVL was touching the corner of the vertebra lateral to the pedicle border. Patients with nSTV, nSTV+1, or STV selected as LIV were assigned to three groups with clinical outcomes compared among them. Factors associated with the incidence of adding-on were analyzed.

Results: Distal adding-on was observed in 23 patients (22.1%). The incidence of distal adding-on was significantly higher in nSTV group than STV group or nSTV+1 group. Several risk factors significantly associated with adding-on were identified, including the distance between LIV and STV/nSTV+1, preoperative proximal thoracic curve and sagittal vertical axis, postoperative lumbar lordosis, apical translation, trunk shift, and radiographical shoulder height. Logistic regression analysis showed that the distance between LIV and STV/nSTV+1 (LIV-STV <0 or LIV-(nSTV+1) <0) was the only independent factor associated with the incidence of adding-on (odds ratio = 27.1, 95% confidence interval = 2.3-311.2, P = 0.002).

Conclusion: Differentiating STV from nSTV properly can facilitate the determination of optimal LIV and decrease the incidence of distal adding-on. Selecting STV or nSTV+1 as LIV could yield a promising outcome for Lenke 1A scoliosis patients undergoing selective posterior thoracic fusion.

Level of evidence: 3.

PubMed Disclaimer

References

    1. Lenke LG. The Lenke classification system of operative adolescent idiopathic scoliosis. Neurosurg Clin North Am 2007; 18:199–206.
    1. Lenke LG, Betz RR, Harms J, et al. Adolescent idiopathic scoliosis: a new classification to determine extent of spinal arthrodesis. J Bone Joint Surg Am 2001; 83-a:1169–1181.
    1. Lee MC, Ounpuu S, Solomito M, et al. Loss in spinal motion from inclusion of a single midlumbar level in posterior spinal fusion for adolescent idiopathic scoliosis. Spine 2013; 38:E1405–E1410.
    1. Marks M, Newton PO, Petcharaporn M, et al. Postoperative segmental motion of the unfused spine distal to the fusion in 100 patients with adolescent idiopathic scoliosis. Spine 2012; 37:826–832.
    1. Sanchez-Raya J, Bago J, Pellise F, et al. Does the lower instrumented vertebra have an effect on lumbar mobility, subjective perception of trunk flexibility, and quality of life in patients with idiopathic scoliosis treated by spinal fusion? J Spinal Disord Tech 2012; 25:437–442.