A predictive scoring system for proximal junctional kyphosis after posterior internal fixation in elderly patients with chronic osteoporotic vertebral fracture: A single-center diagnostic study

Novel radiological predictors for the progression of proximal junctional kyphosis in osteoporotic vertebral compression fracture with kyphosis following posterior corrective surgery

OBJECTIVE

This study aimed to identify the effect of some novel risk factors associated with L1 vertebrae and parameters closely related to the sagittal alignment for the occurrence of proximal junctional kyphosis (PJK) following surgery for patients with osteoporotic vertebral compression fractures (OVCF) kyphosis.

METHODS

74 OVCF patients undergoing posterior corrective surgery between January 2008 and June 2021 with a minimum 2-year follow-up were included. These patients were divided into PJK and non-PJK groups. Spinopelvic parameters, including thoracolumbar slope (TLS) and the L1 plumb line (L1PL) were measured preoperatively, postoperatively, and at follow-up. Multivariate logistic analysis was performed on various risk factors and Global Alignment and Proportion (GAP) scores. Associations between novel parameters and PJK were analyzed using receiver operating characteristic (ROC) analysis.

RESULTS

PJK was identified in 28.4% of patients. The mean age and follow-up were 63.45 years and 38.17 months, respectively. There was no difference between the PJK and the non-PJK groups in baseline demographics, pre-operative and immediate post-operative pelvic incidence-lumbar lordosis mismatch. Multiple comparisons showed that the proportion of PJK in the severely disproportioned group(the group with the highest GAP scores) and that of the other two groups with lower GAP scores were statistically different (P < 0.001). Potential risk factors for PJK included preoperative thoracic kyphosis (TK) (P < 0.001), TLS (P = 0.016), postoperative TLS (P < 0.001), and L1PL (P < 0.001). Postoperative TLS and L1PL were respectively independent risk factors for PJK, with the cut-off values set at 8.6° and 10.4 mm to predict the occurrence of PJK.

CONCLUSIONS

TLS and L1PL can be used to predict the occurrence of PJK in patients undergoing surgery for OVCF and are crucial for preventing the progression of PJK. Achieving a proportionate GAP Score postoperatively seems to be a viable option as higher GAP scores were associated with higher rates of PJK.

Risk Factor Analysis of Mechanical Complications in Surgical Treatment of Thoracolumbar Deformity with Osteoporotic Vertebral Fracture

Objective: Adult spinal deformity (ASD) with osteoporotic vertebral fractures (OVF) often requires vertebral body resection and replacement. However, postoperative mechanical complications (MC) have been unsolved issues. This study retrospectively investigated the risk of MC following anterior-posterior spinal fusion (APF) with vertebral body resection and replacement for OVF with ASD. Methods: Among 91 cases undergoing APF with vertebral body resection and replacement, 43 cases met the deformity criteria. The mean age was 74.2 years, and the mean number of fused segments was 5.7. Pre and postoperative spinal alignments were measured, and the risk of MC occurrence, including PJK, DJK, and cage sinking, was determined through multivariate analysis. The AUC and cutoff values were calculated through ROC analysis. Results: The incidence of MC, PJK, and DJK were 28%, 12%, and 14%, respectively. Multivariate analysis for MC revealed postoperative PI-LL and operative time (cutoff: 40.5 degrees, 238 min) as significant risk factors, while postoperative PI-LL was a significant risk factor for PJK (cutoff: 42.4 degrees). Evaluation considering only thoracolumbar level showed postoperative local kyphosis as a significant MC risk factor (cutoff: 11 degrees). There was a positive correlation between operative time and preoperative local kyphosis, with a cutoff value of 238 min being equivalent to 21 degrees. Conclusion: The postoperative mismatch over 40 degrees and preoperative local kyphosis over 21 degrees were considered as a high risk for MCs. The postoperative kyphosis of 11 degrees was the risk factor of MC in the thoracolumbar level. The meticulous preoperative assessment, including local and global alignment, and local flexibility as well as detailed surgical planning of fixation range and the requirement of osteotomy, are crucial.

Cement-Augmented Versus Conventional Pedicle Screws in Surgical Management of Osteoporotic Vertebral Fractures

OBJECTIVE

Cement-augmented pedicle screws (CAPS) are expected to have fewer complications than conventional pedicle screws (PS), including less risk of postoperative screw loosening and loss of correction. However, use of CAPS has been associated with a risk of other complications, such as cement leakage. In this study, we investigated the usefulness of CAPS for osteoporotic vertebral fractures (OVF) by comparing its surgical outcomes with those of PS.

METHODS

The study included 46 patients (PS group, n=29; CAPS group, n=17) who underwent posterior fixation surgery for OVF at our hospital or an affiliated hospital between August 2019 and August 2023 and were followed up for 12 months postoperatively. We collected background information on each patient, including age, sex, body mass index, diagnosis, and whether they were receiving osteoporosis treatment. We also examined the level of the lesion, the range of fixation (1-1, 2-2, 3-3), whether posterior bone grafting was performed, whether anterior column reconstruction was performed, and the corrected angle. We compared surgery-related factors, including the rate of revision surgery within 12 months postoperatively, adjacent vertebral fracture, screw loosening, and loss of angle correction at 12 months postoperatively between the two groups. We also evaluated cement leakage in the CAPS group. Logistic and linear regression analyses were used to evaluate the factors associated with each outcome.

RESULTS

The Elixhauser Comorbidity Index value was significantly higher in the PS group, (P=0.042), but there were no significant differences between the groups in other factors. Cement leakage was confirmed in seven of the 17 cases in the CAPS group, all of which were asymptomatic. There was no significant difference between the groups in the incidence of adjacent vertebral fractures, screw loosening, or loss of correction. There was also no significant difference in the incidence of early revision surgery between the PS group (7/36 cases) and the CAPS group (7/40 cases). The risk of adjacent vertebral fracture was shown to be significantly higher at the thoracic level than at the thoracolumbar level (odds ratio 34, P=0.043). The risk of thoracic vertebral fracture was significantly higher than that of thoracolumbar vertebral fracture in cases with loss of angle correction (B=1.312, P=0.029). No significant risk factors for screw loosening were identified.

CONCLUSIONS

There was no significant difference in surgical outcomes between CAPS and conventional PS when used in posterior fusion surgery for thoracolumbar fractures. However, use of CAPS was associated with a risk of cement leakage. Therefore, the indications for its use should be carefully considered. Long-term, large-scale prospective studies are needed to assess the usefulness of CAPS in more detail.

Short-Term Risk Factors for Distal Junctional Kyphosis after Spinal Reconstruction Surgery in Patients with Osteoporotic Vertebrae

STUDY DESIGN

Level 3 retrospective cohort case-control study.

PURPOSE

This study aimed to investigate the risk factors for distal junctional kyphosis (DJK) caused by osteoporotic vertebral fractures following spinal reconstruction surgery, with a focus on the sagittal stable vertebra.

OVERVIEW OF LITERATURE

Despite the rarity of reports on DJK in this setting, DJK was reported to reduce when the lower instrumented vertebra (LIV) was extended to the sagittal stable vertebra in the posterior corrective fixation for Scheuermann's disease.

METHODS

This study included 46 patients who underwent spinal reconstruction surgery for thoracolumbar osteoporotic vertebral fractures and kyphosis and were followed up for 1 year postoperatively. DJK was defined as an advanced kyphosis angle >10° between the LIV and one lower vertebra. The patients were divided into groups with and without DJK. The risk factors of the two groups, such as patient background, surgery-related factors, radiographic parameters, and clinical outcomes, were analyzed.

RESULTS

The DJK and non-DJK groups included 14 and 32 patients, respectively, without significant differences in patient background. Those with instability in the distal adjacent LIV disc had a significantly higher risk of DJK occurrence (28.6% vs. 3.2%, p=0.027). DJK occurrence significantly increased in those with the sagittal stable vertebra not included in the fixation range (57.1% vs. 18.8%, p=0.020). Other preoperative radiographic parameters were not significantly different. Instability in the distal adjacent LIV disc (adjusted odds ratio, 14.50; p=0.029) and the exclusion of the sagittal stable vertebra from the fixation range (adjusted odds ratio, 5.29; p=0.020) were significant risk factors for DJK occurrence.

CONCLUSIONS

Regarding spinal reconstruction surgery in patients with osteoporotic vertebral fractures, instability in the distal adjacent LIV disc and the exclusion of the sagittal stable vertebra from the fixation range were risk factors for DJK occurrence in the short term.

A predictive scoring system for postoperative delirium in the elderly patients with intertrochanteric fracture

OBJECTIVE

To establish a scoring system to predict the postoperative delirium in elderly patients with intertrochanteric fracture.

MATERIALS AND METHODS

We retrospectively reviewed 159 elderly patients with a diagnosis of intertrochanteric fracture and underwent closed reduction and intramedullary nail fixation, and then divided them into two groups including the delirium group (23 cases) or non-delirium group (136 cases) in our hospital from January 2017 to December 2019. The following clinical characteristics were recorded and analyzed: age, gender, fracture classification, body mass index (BMI), history of diabetes mellitus, history of stroke, preoperative albumin, preoperative hemoglobin (Hb), preoperative arterial partial pressure of oxygen (PaO₂), time between admission and surgery, lower limb thrombosis, American Society of Anesthesiologists (ASA) grade, operative time, operative blood loss, and intraoperative blood transfusion. The prevalence of these clinical characteristics in delirium group was evaluated, and the scoring system was established using logistic regression analysis. The performance of the scoring system was also prospectively validated.

RESULTS

The predictive scoring system was based on five clinical characteristics confirmed as significant predictors of postoperative delirium, namely, age > 75 years, history of stroke, preoperative Hb ≤ 100 g/L, preoperative PaO₂ ≤ 60 mmHg, and time between admission to surgery > 3 days. Delirium group showed a significant higher score than non-delirium (6.26 vs. 2.29, P < 0.001), and the optimal cut-off value for the scoring system was 4 points. The sensitivity and specificity of the scoring system for predicting postoperative delirium were 82.61% and 81.62% in derivation set, respectively, and 72.71% and 75.00% in validation set.

CONCLUSION

The predictive scoring system confirmed with achieve satisfactory sensitivity and specificity in predicting postoperative delirium in the elderly with intertrochanteric fracture. The risk of postoperative delirium in patients with the score of 5 to 11 is high, while the score of 0 to 4 is low.