Does lumbar lordosis minus thoracic kyphosis predict the clinical outcome of patients with adult degenerative scoliosis?

Odontoid incidence: a constant cervical anatomical feature evident in standing plain radiographs and supine magnetic resonance images

OBJECTIVE

To assess whether there is a difference between measurements of odontoid incidence (OI) and other cervical sagittal parameters by X-ray radiography and those by supine magnetic resonance imaging (MRI).

METHODS

Standing X-ray and supine MRI images of 42 healthy subjects were retrospectively analyzed. Surgimap software was employed to measure cervical sagittal parameters including OI, odontoid tilt (OT), C2 slope (C2S), C0-2 angle, C2-7 angle, T1 slope (T1S) and T1S-cervical lordosis (CL). Paired samples t-test was applied to determine the difference between parameters measured by standing X-ray and those by supine MRI. In addition, the statistical correlation between the parameters were compared. The prediction of CL was performed and validated using the formula CL = 0.36 × OI - 0.67 × OT - 0.69 × T1S.

RESULTS

Significant correlations and differences were found between cervical sagittal parameters determined by X-ray and those by MRI. OI was verified to be a constant anatomic parameter and the formula CL = 0.36 × OI - 0.67 × OT - 0.69 × T1S can be used to predict CL in cervical sagittal parameters.

CONCLUSIONS

OI is verified as a constant anatomic parameter, demonstrating the necessity of a combined assessment of cervical sagittal balance by using standing X-ray and supine MRI. The formula CL = 0.36 × OI - 0.67 × OT - 0.69 × T1S can be applied to predict CL in cervical sagittal parameters.

Correlation between Degenerative Thoracolumbar Kyphosis and Lumbar Posterior Muscle

The relationship between spinal alignment, particularly degenerative thoracolumbar kyphosis (DTLK) combined with lumbar spine stenosis (LSS), and paraspinal muscle content remains underexplored. This study aimed to elucidate the characteristics of paraspinal muscle distribution in DTLK patients and its association with lumbar lordosis (LL) and body mass index (BMI).

METHODS

A case-control study was conducted comparing 126 patients with DTLK and LSS against 87 control patients. The lumbar crossing indentation value (LCIV) was introduced as a novel measurement for paraspinal muscle content, and its relationship with thoracolumbar kyphosis (TLK), BMI, and LL was assessed.

RESULTS

LCIV in DTLK patients was found to be lower than in the control group, with a progressive increase from the upper to lower lumbar spine. In the control group, paraspinal muscle content was observed to increase with age and BMI, and LCIV was higher in males. However, the DTLK group showed no gender difference. LCIV in the DTLK group was more pronounced in patients with increased LL. The degree of TLK was not influenced by BMI but was associated with the content of the paravertebral muscle.

CONCLUSIONS

Paraspinal muscle content, as measured by LCIV, is significantly associated with DTLK and LSS. The study emphasizes the importance of considering paraspinal muscle health in DTLK patients and offers valuable insights for diagnosis and therapeutic interventions.

Which Global Sagittal Parameter Could Most Effectively Predict the Surgical Outcome for Patients With Adult Degenerative Scoliosis?

STUDY DESIGN

Retrospective study.

OBJECTIVE

To evaluate the predictive effect of the 3 global sagittal parameters (Sagittal Vertical Axis [SVA], T1 Pelvic Angle [TPA], and relative TPA [rTPA]) in the surgical outcome of patients with adult degenerative scoliosis (ADS), then to define the optimum corrective goal based on the best of them.

METHODS

117 ADS patients were included in this study and followed-up for an average of 3 years. Functional evaluation and radiographs were assessed preoperatively and postoperatively. The predictive accuracy of SVA, TPA, and relative TPA was analyzed through receiver operating characteristic (ROC) curve. The cutoff value of TPA was obtained at the maximal Youden index from ROC curve.

RESULTS

TPA most highly correlated with postoperative oswestry disability index (ODI). The best cutoff value of TPA was set at 19.3° (area under curve =0.701). TPA >19.3° was the highest risk factor in multivariate logistic regression analysis (OR = 7.124, P = 0.022). Patients with TPA <19.3° at 3 months after operation showed a better ODI than those with TPA >19.3°. Correcting TPA less than 19.3° for patients with preoperative TPA >19.3° attributed to a better health related quality of life (HRQOL) and sagittal balance at last follow-up. The formula "Postoperative TPA = 0.923 × PI - 0.241 × postoperative LL - 0.593 × postoperative SS - 2.471 (r = 0.914, r2 = 0.836, P < .001)" described the relation between SS, LL, PI, and TPA.

CONCLUSION

TPA was a useful global parameter for the prediction of postoperative HRQOL for patients with ADS. Keeping TPA <19.3° could improve the postoperative HRQOL for ADS patients with preoperative TPA >19.3°, and TPA <19.3° could be an optimum correction target for patients with ADS.

Physical and radiographic features of degenerative retrolisthesis in Japanese female volunteers: an observational cohort study

Hundred and twenty four females with spondylolisthesis were divided into three groups (A group: anterolisthesis; P group: retrolisthesis; and AP group: antero-retrolisthesis), We reviewed their whole-spine radiographs and measured their standard sagittal parameters, including thoracic kyphosis (TK), pelvic incidence (PI), lumbar lordosis (LL), pelvic tilt (PT), and sacral slope (SS). The muscle strengths of the trunk flexor, trunk extensor, iliopsoas, and quadriceps were measured. Health-related quality of life was assessed using the Short Form 36-item Health Survey-physical component summary (SF-36 PCS). PI, SS, and LL-TK of participants in the P group were significantly lower than those in the A and AP groups (PI: P group vs. A group, p < 0.001, P group vs. AP group, p = 0.01), (SS: P group vs. A group, p = 0.001, P group vs. AP group, p = 0.003), (LL-TK: P group vs. A group, p < 0.001, P group vs. AP group, p = 0.049). TK of participants in the P and AP groups was greater than that of those in the A group. (P group vs. A group, p = 0.04, AP group vs. A group, p = 0.0025). The SF-36 PCS score in the P group was lower than that in the A and AP groups. (P group vs. A group, p = 0.004, P group vs. AP group, p = 0.012). The muscle strengths of the trunk flexor and trunk extensor and quadriceps in the P group were lower than those in the A groups. (Trunk flexor: P group vs. A group, p = 0.012), (Trunk extensor: P group vs. A group, p = 0.018), (Quadriceps: P group vs. A group, p = 0.011). In conclusion, female participants with degenerative retrolisthesis had a smaller PI and SS and a larger TK, along with decreased physical function and QoL scores than those with anterolisthesis.

The Pelvic Incidence Stratified Sagittal Spinopelvic Alignment in Asymptomatic Chinese Population With Different Age Groups

STUDY DESIGN

Cross-sectional study.

OBJECTIVE

To provide the age- and pelvic incidence-related variations of sagittal alignment in asymptomatic Chinese population.

METHODS

This study recruited asymptomatic adult subjects. All subjects undertook the standing whole spinal radiograph and the sagittal parameters were measured: sagittal vertical axis (SVA), T1 pelvic angle (TPA), lumbar lordosis (LL), thoracic kyphosis (TK), pelvic incidence (PI) and pelvic tilt (PT). All subjects were divided into young, middle aged and elderly groups, then each age group was further divided into 5 subgroups (very low, low, average, high and very high) based on PI values. The relations between PI, age and other parameters were evaluated. The differences in sagittal parameters of each PI subgroup were compared.

RESULTS

546 subjects were included with an average age of 38.6 years (18 to 81). The number of subjects over 70 years and with very low PI was relatively small. The average of PI, TPA, PT and LL were 45.9° ± 8.4°, 6.4° ± 6.2°, 11.9° ± 6.6° and 49.2° ± 10.1°, respectively. SVA, TPA, TK and PT increased with age (P < 0.05), while SVA, TPA, PT, PI-LL also increased with PI (P < 0.05). LL, PT, TPA, PI-LL and LL-TK were different among the 5 PI subgroups (P < 0.05). However, the values of LL in elderly subjects with high and very high PI were similar.

CONCLUSION

The age- and PI-related variations in sagittal alignment of Chinese population were provided. The sagittal parameters were significantly influenced by age and PI. The individual pelvic morphology should be carefully considered during the assessment and restoration of sagittal balance.

The kyphosis–lordosis difference parameter and its utility in understanding the pathogenesis of adolescent idiopathic scoliosis

Objective

The relationship of sagittal spinal shape in the pathogenesis of adolescent idiopathic scoliosis (AIS) is recognised. What is not clear is the relationship between the sagittal shape of those without scoliosis and the potential development of AIS, including the greater prevalence in females. The use of a new parameter, the kyphosis–lordosis (KL) difference, was developed to explore this further.

Results

The KL difference was calculated for 117 males and 79 females over seven years with 831 measures made. For females, the KL difference, between the ages of 9 and 12 ½ years, decreases from 5° to nearly 0° until starting to climb again from the age of 14 years, back to 5° by the age of 16 ½ years. For males, there is a gradual decline from 9° at age 9 years to 5° at age 17 years. Both age and sex were statistically significant in the development of the parameter. When comparing to previously published data around the true, de-rotated, sagittal shape of the scoliotic spine, the KL difference has utility in explaining the female predominance in the prevalence of AIS. This adds to the weight of evidence behind understanding why AIS develops.

Correlation Between Different Sagittal Parameters in Patients With Degenerative Kyphosis

Objective

To explore the relationship between different sagittal parameters and identify the fitting formula of spino-pelvic parameters in patients with degenerative kyphosis (DK).

Summary of Background

Sagittal balance is increasingly recognized as a predictor of clinical outcomes in patients with DK, while the relationship between different sagittal parameters in patients with DK remains unidentified.

Methods

A retrospective study with 279 participants was conducted. There were 168 DK patients which were divided into a sagittal balance group (SB:52 cases) and sagittal imbalance (SIB:116 cases). Radiographic measurements included thoracolumbar kyphosis (TLK), lumbar lordosis (LL), thoracic kyphosis (TK), pelvic incidence (PI), and pelvic tilt (PT). The correlations were analyzed between different sagittal parameters.

Results

There were significant differences between the SB and SIB groups in terms of TLK, LL, PI-LL, PT, SVA, sacral slope (SS), and TK. For patients with DK, the LL was correlated with PT and TK. The linear regression was LL = 22.76−0.28 × PT + 0.62 × TK. In the SB group, TK was the influencing factor for LL and the linear regression analysis showed that LL = 33.57 + 0.33 × TK. While in the SIB group, PT and TK were in synergistic effect with PI-LL, the linear regression analysis showed that LL = 22.76−0.28 × PT + 0.62 × TK.

Conclusion

From the present study, we can see that LL has a significant correlation with PT and TK in patients with DK, while in SB, the LL was only correlated with TK. Therefore, the correction of LL in a different group should be calculated to avoid the incidence of proximal junction kyphosis (PJK).

Pelvic and sacral morphology and their correlation with pelvic incidence, lumbar lordosis, and lumbar alignment changes between standing and sitting postures

STUDY DESIGN

Retrospective Cross-Sectional Radiographic Study.

OBJECTIVE

This study aims to describe novel radiographic markers of sacropelvic morphology to further define the static and dynamic relationship between the pelvis and the spine, via the analysis of two postures - standing and sitting.

SUMMARY OF BACKGROUND DATA

There is increasing evidence underlining the importance of spinopelvic radiographic parameters in the holistic management of sagittal spinal deformity given the close relationship between pelvic morphology and spinal profile.

METHODS

This is a retrospective radiographic study of patients who presented with the first episode of isolated mechanical, low back pain of fewer than 3 months' duration. All patients underwent whole spine radiographs using EOS technology in both standing and relaxed sitting postures. Six novel distance measurements (H1, H2, H3, V1, V2, DD) to determine pelvic dimensions, and 3 novel angles (A, B, C) to determine sacral morphology were described.

RESULTS

A total of 64 males (58.2%) and 46 females (41.8%) with a mean age of 42.8 ± 18.6 (range:17-81) years old was studied. Between standing and relaxed sitting postures, differences were observed in all sagittal radiographic parameters. Multivariate analysis showed that standing LL< 50⁰ (p = 0.008), standing V1 > 13 cm(p = 0.040), and angle B> 80⁰(p = 0.002) are predictive of PI< 5⁰⁰, standing TK< 30⁰ (p = 0.003) and PI< 50⁰ (p = ⁰.006) are predictive of LL< 5⁰⁰, and standing PT< 17⁰(p = 0.034), standing H3 ≥ 4 cm (p = 0.030), standing angle C< 42⁰ (p = 0.003), sitting SS≥ 6⁰ (p = ⁰.002), and sitting PT < 45⁰ (p = 0.013) are predictive of change in LL below mean difference of 42⁰ between standing and relaxed sitting.

CONCLUSIONS

Apart from the known correlation between TK, LL and PI, low PI was found to be associated with a tall pelvis and a straight sacrum (angle B). Association between a small coccygeal inclination angle (angle C) and smaller change in LL between standing and relaxed sitting may have clinical relevance.

A hybrid therapeutic approach for decreasing postoperative complications in patients with adult lumbar degenerative scoliosis

To decrease postoperative complications in patients with adult lumbar degenerative scoliosis (ALDS), short-segment fusion surgery was used in this study. However, the incidence of adjacent segment disease was found to be remarkable. Therefore, we applied the hybrid treatment (short-segment fusion for responsibility levels plus nonfusion stabilization of lumbar segments, which was called the Wallis system, for the proximal level) to patients enrolled into this study. The purpose of this study was to investigate the feasibility of a novel hybrid therapeutic approach for treating patients with ALDS.From January 2011 to January 2017, a retrospective study was conducted consisting of 16 patients with ALDS who were treated with hybrid treatment. All patients were treated with short-segment decompression and fusion for responsibility levels and nonfusion stabilization of lumbar segments for the proximal levels. The imaging outcomes were evaluated preoperatively and at the time of follow-up.The mean visual analog score for back pain decreased from 6.1 ± 2.0 preoperatively to 2.1 ± 0.7 at 2-year follow-up (P < .05), and the mean visual analog score for leg pain reduced from 8.1 ± 0.6 preoperatively to 1.3 ± 0.8 at 2-year follow-up (P < .05). The Oswestry disability index scores improved from 65.4 ± 16.3% preoperatively to 18.3 ± 5.6% at 2-year follow-up (P < .05). The mean Cobb angle was 22.1 ± 6.2° preoperatively, and 13.8 ± 6.8° at 2-year follow-up (P < .05). The lumbar lordosis changed from -40.4 ± 14.8° to -43.5 ± 11.2° at 2-year follow-up (P < .05). Solid fusion was achieved in all the patients, and no incidence of adjacent segment disease was noted as well.The proposed hybrid treatment for patients with ALDS can achieve favorable clinical outcomes and a lower incidence of ALDS. However, the correction of deformity is still limited that highlights the necessity of further study.