Journal List > J Korean Soc Spine Surg > v.16(3) > 1035852

Kim, Kang, Yang, Kang, Park, Park, Sung, and Choy: Radiologic Analysis of Postoperative Sagittal Plane Correction in Lumbar Degenerative Kyphosis (LDK)

Abstract

Study Design

This is a retrospective study

Objectives

We radiologically analyzed the correction of the sagittal imbalance and the proximal fusion level to prevent correction loss and the usefulness of iliac screws in LDK.

Summary of the Literature Review

Complications can be encountered during fixation and fusion as most of the LDK patients are aged, and the osteoporosis that causes fixation loss is known to affect the loss of correction.

Materials and Methods

We analyzed the cause of correction loss among 35 patients who underwent surgery and who were followed up for at least 1 year. All the patients had performed gait analysis before operation. The operative techniques were pedicle subtraction osteotomy and fixation to S1. For analyzing causes of correction loss, we analyzed the degrees of lumbar lordosis for the sagittal correction and the degrees of the preoperative thoracolumbar kyphosis for the proximal fusion range. For analyzing the usefulness of iliac screws, the subjects were divided into two groups: 1) the -iliac screw (23cases) group for the patients who were fixed without iliac screws and 2) the +iliac screw (12cases) group for the patients who were fixed with iliac screws.

Results

There were no patients who had marked anterior pelvic tilt. It is important to correct the lumbar lordosis over 20° compared with the preoperative thoracic kyphosis. There are 10 cases of preoperative thoracolumbar kyphosis ≥ 10° and 25 cases of preoperative thoracolumbar kyphosis < 10° of the total 35 cases. Among 10 cases of preoperative thoracolumbar kyphosis ≥ 10°, 4 cases that were fixed to T10 had no sagittal correction loss, and 2 of the 6 cases that were fixed to T11 or T12 had sagittal correction loss. For the 25 cases of preoperative thoracolumbar kyphosis < 10°, 5 cases that were fixed to T10 had no sagittal correction loss and 1 of the 20 cases that were fixed to T11 or T12 had sagittal correction loss (p<0.05). 6 cases (26%) in the -iliac screw group (23 cases total) and 1 case (8%) in the +iliac screw (12 cases total) showed sagittal correction loss (p<0.05).

Conclusions

It is important to make the postoperative lumbar lordosis over 20。compared with the preoperative thoracic kyphosis for correcting sagittal imbalance, to decide on the proximal fixation level according to the preoperative thoracolumbar kyphosis and to fix with iliac screws.

REFERENCES

1). Lee CS, Kim YT, Kim E. Clinical Study of Lumbar Degenerative Kyphosis. J Korean Spine Surg. 1997; 4:27–35.
2). Lee CS, Lee CK, Kim YT, Hong YM, Yoo JH. Dynamic Sagittal Imbalance of the Spine in Degenerative Flat Back. Spine. 2001; 26:2029–2035.
crossref
3). Kim HJ, Kang JW, Yeom JS, et al. .:. A Comparative Analysis of Sagittal Spinal Balance in 100 Asymptomatic Young and Older Aged Volunteers. J Korean Spine Surg. 2003; 4:327–334.
crossref
4). Noun Z, Lapresle P, Missenard G. Posterior lumbar osteotomy for flat back in adults. J spinal Disord. 2001; 14:311–316.
crossref
5). Kim HJ, Kang JW, Kim HY, et al. .:. Change of Pelvic Tilt before and after Gait in Patients with Lumbar Degenerative Kyphosis. J Korean Spine Surg. 2009; 16:95–103.
crossref
6). Kim YJ, Bridwell KH, Lenke LG, Rhim S, Cheh G. An Analysis of Sagittal Spinal Alignment Following Long Adult Lumbar Instrumentation and Fusion to L5 or S1: can we predict ideal lumbar lordosis? Spine. 2006; 31:2343–2352.
crossref
7). Swank ML. Adjacent segment failure above lumbosacral fusions instrumented to L1 or L2. Podium presentation at the. Scoliosis Research Society;37th annual meeting. September 18-21, 2002. Seattle, WA, USA.
8). Suk SI, Kim JH, Lee SM, et al. .:. Incidence of proximal adjacent failure in adult lumbar deformity correction. Podium presentation at the. Scoliosis Research Society;38th annual meeting. September 10-13, 2003. Quebec City, Canada.
9). Kim YJ, Bridwell KH, Lenke LG, Rhim S, Kim YW. Is the T9, T11, or L1 the more reliable proximal level after adult lumbar or lumbosacral instrumented fusion to L5 or S1? Spine. 2007; 32:2653–2661.
crossref
10). Lee CS, Oh WH, Chung SS, Lee SG, Lee JY. Analysis of the Sagittal Alignment of Normal Spines. J of Korean Ortho. 1999; 34:949–954.
crossref
11). Bernhardt M, Bridwell KH. Segmental Analysis of the Sagittal Plane Alignment of the Normal Thoracic and Lumbar Spines and Thoracolumbar Junction. Spine. 1989; 14:717–721.
crossref
12). Edwards CC 2nd, Bridwell KH, Patel A, Rinella AS, Berra A, Lenke LG. Long Adult Deformity Fusions to L5 and the Sacrum A Matched Cohort Analysis. Spine. 2004; 29:1996–2005.
crossref
13). Bernhardr M, Swartz DE, Clothiaux PL, et al. .:. Posterolateral lumbar and lumbosacral fusion with without pedicle screw internal fixation. Clin Orthop Rela Res. 1992; 284:109–115.
14). Horowitch A, Peek RD, Thomas JC Jr, et al. .:. The Wiltse pedicle screw fixation system. Early clinical results. Spine. 1989; 14:461–467.
15). Molinari RW, Bridwell KH, Lenke LG, Unqacta FF, Riew KD. Complications in the surgical treatment of pediatric high-grade isthmic dysplastic spondylolisthesis. A comparison of three surgical approaches. Spine. 1999; 24:1701–1711.
16). Rechtine GR, Sutterlin CE, Wood GW, Boyd RJ, Mansfield FL. The efficacy of pedicle screw/plate fixation on lumbar/lumbosacral autogenous bone graft fusion in adult patients with degenerative spondylolisthesis. J Spinal Disord. 1996; 9:382–391.
crossref
17). Kim HJ, Kang JW, Kim KH, et al. .:. Analysis of Correc-tiom Loss aster Pedicle subtraction Osteotomy in patients with Sagittal Imbalance? Radiologic Aspects-. J Korean Spine Surg. 2004; 39:629–635.
18). Kim YJ, Bridwell KH, Lenke LG, Rhim S, Cheh G. Pseudarthrosis in long adult spinal deformity instrumentation and fusion to the sacrum: prevalence and risk factor analysis of 144 cases. Spine. 2006; 31:2329–2336.
crossref
19). Tsuchiya K, Bridwell KH, Kuklo TR, Lenke LG, Baldus C. Minimum 5-Year Analysis of L5-S1 Fusion Using Sacropelvic fixation(Bilateral S1 and Iliac screws) for Spinal Deformity. Spine. 2006; 31:303–308.
20). Emami A, Deviren V, Berven S, Smith JA, Hu SS, Bradford DS. Outcome and Complications of long fusions to the Sacrum in Adult Spine Deformity: Luque-Galveston, Combined Iliac and Sacral Screws, and Sacral Fixation. Spine. 2002; 27:776–786.

Figures and Tables%

Fig. 1.
A 66-year old woman with Lumbar degenerative kyphosis. (A) Preoperative thoracolumbar kyphosis 25°(B) Postoperative sagittal balance after spinal fusion from T12 to S1 and L3 PSO (C) Sagittal balance loss due to proximal screw loosening after postoperative 4 years later. PSO, Pedicle subtraction osteotomy
jkss-16-177f1.tif
Fig. 2.
A 62-year old woman with Lumbar degenerative kyphosis. (A) Preoperative thoracic kyphosis 25°, thoracolumbar kyphosis 25° (B) Proper sagittal balance after spinal fusion from T10 to S1 and L3 PSO. Postoperative lumbar lordosis -45° (C) Maintain proper sagittal balance after 2 years later operation. PSO, Pedicle subtraction osteotomy
jkss-16-177f2.tif
Fig. 3.
A 73-year old woman with Lumbar degenerative kyphosis. (A) Preoperative thoracic kyphosis 16°, thoracolumbar kyphosis 14°, lumbar lordosis -7°(B) Proper sagittal balance after spinal fusion from T10 to S1 with iliac screw and L3 PSO. Postoperative lumbar lordosis -45° (C) Maintain proper sagittal balance after 2 years later operation. PSO, Pedicle subtraction osteotomy
jkss-16-177f3.tif
Table 1.
Radiologic analysis of patients according to lumbar lordosis correction
A group(7cases) B group(28cases) p-value
Preop. Postop. Preop. Postop.
T-Kyphosis(°) 18.8 12.2 7.5 18.5
L-Lordosis(°) -1.6 -31 -9.3 -45.9
SVA(㎝) 10.3 2.3 0.03

Preop., Preoperative angle; Postop., Postoperative angle T-kyphosis, thoracic kyphosis; L-lordosis, lumbar lordosis; SVA, sagittal vertical axis

Table 2.
No. of proximal junctional problem
Proximal fusion level T-L kyphosis≥10° T-L kyphosis<10°
T10 T11 or T12 T10 T11 or T12
No. of total case 4 6 5 20
No. of proximal junctional problem 0 2 0 1

No., number; T-L, thoracolumbar (p=0.01)

Table 3.
Demographics and preoperative radiologic measurement of patients with or without iliac screw
-iliac screw (23cases) +iliac screw (12cases) p-value
Age (year) 64 68
No. of levels fused 6.4 7.3
F/U (month) 25.4 14
T-kyphosis(°) 2.8 2.6 0.17
T-L kyphosis(°) 6.8 6.6 0.13
L-lordosis(°) -10 -11 0.08
Radiologic Pelvic tilt(°) 44 42 0.2
Pelvic tilt in Gait analysis(°) 12.7 12.0 0.15

No., number; F/U, follow up; T-kyphosis, Thoracic kyphosis T-L kyphosis, Thoracolumbar kyphosis

Table 4.
Postoperative & F/U measurement of patients with or without iliac screw
-Iliac screw (23cases) +Iliac screw (12cases) p-value
SVA (cm) Postop. 3.5 1.2
Last F/U 7.5 5.3
No. of correction loss 6(26%) 1(8.3%) 0.01

SVA, Sagittal vertical axis; Postop., Postoperative; F/U, follow up; No., number

Table 5.
Site of occurring correction loss in both group (-Iliac screw and +Iliac screw)
-Iliac screw (6cases) +Iliac screw (1case)
Proximal junction 2 1
Distal junction 3 0
Both 1 0

No., number; Both, Proximal junction + Distal junction

Table 6.
Duration of correction loss of both group (-Iliac screw and +Iliac screw)
< Pod 1m < Pod 6m < Pod 1y Average
-Iliac screw 2 4 0 2.2months
+Iliac screw 0 1 0 4.7months

Pod, postoperative day; m, month; y, year

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