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. 2022 Jan;83(1):102-111.
doi: 10.3348/jksr.2021.0017. Epub 2021 Nov 4.

To Assess Whether Lee's Grading System for Central Lumbar Spinal Stenosis Can Be Used as a Decision-Making Tool for Surgical Treatment

Do Yeon Ahn, Hee Jin Park, Jung Woo Yi, Ji Na Kim

To Assess Whether Lee's Grading System for Central Lumbar Spinal Stenosis Can Be Used as a Decision-Making Tool for Surgical Treatment

Do Yeon Ahn et al. Taehan Yongsang Uihakhoe Chi. 2022 Jan.

Abstract
in English, Korean

Purpose: To evaluate the correlation between Lee's grades and surgical intervention for central lumbar spinal stenosis (CLSS) and to assess whether this grading system can be used as a decision-making tool for the surgical treatment of this condition.

Materials and methods: This retrospective study included 290 patients (M:F = 156:134; mean age, 46 ± 16 years). Radiologists assessed the presence and grade of CLSS at the stenosis point according to Lee's grading system, in which CLSS is classified into four grades according to the shape of the cauda equina. Correlation coefficients (rs ) between Lee's grades and the operation were calculated with Spearman rank correlation.

Results: Among the operated patients, grade 2 was the most commonly assigned grade (50%-58%), grade 3 was less common (35%), and grade 0 was the least common (2%-3%). Among the non-operated patients, grade 1 was the most common (63%-65%), grade 0 was less common (15%-16%), and grade 3 was the least common (8%). The distribution of grades differed between the operated and non-operated groups (p < 0.001). Less than 25% of patients who underwent surgery were assigned grades 0 and 1, and more than 88% were assigned grades 2 and 3. A moderate correlation was found between the grade and surgical intervention (rs = 0.632 and rs = 0.583).

Conclusion: Lee's grade was moderately correlated with surgical intervention. Lee's grading system can be a decision-making tool for the surgical treatment of CLSS.

목적: 요추 중심부 협착증(central lumbar spinal stenosis; 이하 CLSS)에 대하여 Lee grading system과 외과적 수술과의 상관관계를 평가하고 이것이 CLSS에 대하여 치료 방법을 정하기 위한 의사 결정 도구로 사용될 수 있는지 평가하고자 하였다.

대상과 방법: 이 후향적 연구에는 290명의 환자가 포함되었다(남:여 = 156:134; 평균 연령, 46 ± 16세). 영상의학과 전문의들은 CLSS를 4등급으로 분류하는 Lee grading system에 따라 협착 지점에서 CLSS의 유무와 등급을 평가했다. Spearman 순위 상관관계를 사용하여 Lee의 등급과 수술 시행 여부 간의 상관 계수를 계산했다.

결과: 수술을 시행한 환자에서 2등급이 가장 흔했고(50%–58%), 3등급이 다음으로 흔했으며(35%), 0등급이 가장 흔하지 않았다(2%–3%). 수술을 받지 않은 환자의 경우 1등급이 가장 흔했고(63%–65%), 0등급이 그 다음(15%–16%), 3등급이 가장 흔하지 않았다(8%). 등급 분포는 수술 치료군과 비수술 치료군 사이에서 유의하게 차이가 있었다(p < 0.001). 수술을 받은 환자의 25% 미만에서 0과 1등급이 있었던 반면 2등급과 3등급이 88% 이상이었다. 등급과 수술 사이에 중간 정도(moderate)의 상관관계가 있었다(rs = 0.632 and rs = 0.583).

결론: Lee grading system은 수술적 치료 시행과 중간 정도의 상관관계가 있었다. Lee grading system은 CLSS의 치료 방법 결정에서 유용하게 사용할 수 있다.

Keywords: Lumbar Vertebrae; Magnetic Resonance; Spinal Canal; Spinal Stenosis; Surgery.

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Conflict of interest statement

Conflicts of Interest: Hee Jin Park has been a Editorial Board Member of the Journal of the Korean Society of Radiology since 2021; however, he was not involved in the peer reviewer selection, evaluation, or decision process of this article. Otherwise, no other potential conflicts of interest relevant to this article were reported.

Figures

Fig. 1
Fig. 1. Illustration of Lee’s grading system.
A. Grade 0: no CLSS, and the anterior CSF space is not obliterated. B. Grade 1: mild CLSS, in which the anterior CSF space is mildly obliterated, but all cauda equina can be clearly separated from each other. C. Grade 2: moderate CLSS, in which the anterior CSF space is moderately obliterated and some of the cauda equina are aggregated, making it impossible to visually separate them. D. Grade 3: severe CLSS, in which the anterior CSF space is obliterated so severely that it shows marked compression of the dural sac, and none of the cauda equina can be visually separated from each other, appearing instead as one bundle. CLSS = central lumbar spinal stenosis, CSF = cerebrospinal fluid
Fig. 2
Fig. 2. Grade 2, operated patient: a 44-year-old female with a tingling sensation and claudication in both lower extremities for two months.
A. Sagittal T2-weighted fast spin-echo image (3000/100, TR/TE) shows compression of the spinal canal by an extruded L4–5 disc. B. Axial T2-weighted fast spin-echo image (2500/100, TR/TE) shows moderate central stenosis with some cauda equina aggregation (arrows), classified as grade 2. The patient underwent surgical intervention. TE = echo time, TR = repetition time
Fig. 3
Fig. 3. Grade 3, operated patient: a 28-year-old male with radiating pain and claudication in both lower extremities for several years.
A. Sagittal T2-weighted fast spin-echo image (2500/100, TR/TE) shows extruded disc material from the L4–5 disc (arrow). B. Axial T2-weighted fast spin-echo image (2700/100, TR/TE) shows severe central stenosis with prominent aggregation of the cauda equina (arrows), classified as grade 3. The patient underwent surgical intervention. TE = echo time, TR = repetition time
Fig. 4
Fig. 4. Grade 1, non-operated patient: a 28-year-old male with lower back pain for several years.
A. Sagittal T2-weighted fast spin-echo image (3200/100, TR/TE) shows mildly protruded disc material from the L4–5 disc. B. Axial T2-weighted fast spin-echo image (2600/100, TR/TE) shows mild central stenosis without aggregation of the cauda equina, classified as grade 1. The patient underwent medical treatment. TE = echo time, TR = repetition time
Fig. 5
Fig. 5. Grade 2, non-operated patient: a 68-year-old male with lower back pain and a tingling sensation in both lower legs for two months.
A. Sagittal T2-weighted fast spin-echo image (3000/100, TR/TE) shows extruded disc material from the L3–4 disc. B. Axial T2-weighted fast spin-echo image (2700/100, TR/TE) shows central stenosis with aggregation of the cauda equina (arrow), classified as grade 2. The patient underwent conservative treatment. TE = echo time, TR = repetition time
See this image and copyright information in PMC

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