Development and internal validation of machine-learning models for predicting survival in patients who underwent surgery for spinal metastases

Study Design

A retrospective study.

Purpose

This study aimed to develop machine-learning algorithms for predicting survival in patients who underwent surgery for spinal metastasis.

Overview of Literature

This study develops machine-learning models to predict postoperative survival in spinal metastasis patients, filling the gaps of traditional prognostic systems. Utilizing data from 389 patients, the study highlights XGBoost and CatBoost algorithms̓ effectiveness for 90, 180, and 365-day survival predictions, with preoperative serum albumin as a key predictor. These models offer a promising approach for enhancing clinical decision-making and personalized patient care.

Methods

A registry of patients who underwent surgery (instrumentation, decompression, or fusion) for spinal metastases between 2004 and 2018 was used. The outcome measure was survival at postoperative days 90, 180, and 365. Preoperative variables were used to develop machine-learning algorithms to predict survival chance in each period. The performance of the algorithms was measured using the area under the receiver operating characteristic curve (AUC).

Results

A total of 389 patients were identified, with 90-, 180-, and 365-day mortality rates of 18%, 41%, and 45% postoperatively, respectively. The XGBoost algorithm showed the best performance for predicting 180-day and 365-day survival (AUCs of 0.744 and 0.693, respectively). The CatBoost algorithm demonstrated the best performance for predicting 90-day survival (AUC of 0.758). Serum albumin had the highest positive correlation with survival after surgery.

Conclusions

These machine-learning algorithms showed promising results in predicting survival in patients who underwent spinal palliative surgery for spinal metastasis, which may assist surgeons in choosing appropriate treatment and increasing awareness of mortality-related factors before surgery.

Safety and feasibility of ultra-long construct navigated minimally invasive spine surgery with adjuvant radiotherapy in extensive spinal metastasis : a comparative analysis

BACKGROUND

Our study compares the outcomes of extensive spinal metastasis patients treated with Ultra-Long Construct Navigated Minimally Invasive Spine Surgery (UNMISS) with Adjuvant Radiotherapy to those receiving only radiotherapy. Spinal metastasis often necessitates interventions like radiotherapy, chemotherapy, or surgery, with an increasing trend towards surgical management. minimally invasive spine surgery has demonstrated advantages over traditional open surgery, with fewer complications and better postoperative outcomes. Radiotherapy continues as a standard for those unsuitable for surgery.

METHODS

This retrospective study included extensive spinal metastasis patients treated between January 2017 and December 2020. We compared patients undergoing UNMISS in conjunction with radiotherapy to patients receiving radiotherapy alone, evaluating demographic data, disease characteristics, and treatment outcomes (VAS, survival) to establish statistical significance.

RESULTS

Twenty-three patients were included in our study. Fourteen patients underwent UNMISS, and nine patients received radiotherapy alone. There was no difference in baseline characteristics of patients. The longest construct in our case series involved T1 to iliac. Both cohorts showed significant improvement in pain scores post-treatment (p = 0.01). However, the UNMISS group demonstrated significantly lower post-treatment VAS scores (p = 0.003), indicating enhanced pain relief. Survival outcomes did not differ significantly between the two groups.

CONCLUSION

The UNMISS should be considered as an alternative treatment in a patient with symptomatic extensive spinal metastasis. The primary goal of this technique is to stabilize the multiple levels of spinal metastasis and decompression of the neural element if needed. This technique is safe and has a better outcome in pain improvement than the patient who received radiotherapy alone.

Development of Machine-Learning Models to Predict Ambulation Outcomes Following Spinal Metastasis Surgery

STUDY DESIGN

Retrospective cohort study.

PURPOSE

This study aimed to develop machine-learning algorithms to predict ambulation outcomes following surgery for spinal metastasis.

OVERVIEW OF LITERATURE

Postoperative ambulation status following spinal metastasis surgery is currently difficult to predict. The improved ability to predict this important postoperative outcome would facilitate management decision-making and help in determining realistic treatment goals.

METHODS

This retrospective study included patients who underwent spinal metastasis at a university-based medical center in Thailand between January 2009 and November 2021. Collected data included preoperative parameters and ambulatory status 90 and 180 days following surgery. Thirteen machine-learning algorithms, namely, artificial neural network, logistic regression, CatBoost classifier, linear discriminant analysis, extreme gradient boosting, extra trees classifier, random forest classifier, gradient boosting classifier, light gradient boosting machine, naïve Bayes, K-neighbor classifier, Ada boost classifier, and decision tree classifier were developed to predict ambulatory status 90 and 180 days following surgery. Model performance was evaluated using the area under the receiver operating characteristic curve (AUC) and F1-score.

RESULTS

In total, 167 patients were enrolled. The number of patients classified as ambulatory 90 and 180 days following surgery was 140 (81.9%) and 137 (82.0%), respectively. The extreme gradient boosting algorithm was found to most accurately predict 180-day ambulatory outcome (AUC, 0.85; F1-score, 0.90), and the decision tree algorithm most accurately predicted 90-day ambulatory outcome (AUC, 0.94; F1-score, 0.88).

CONCLUSIONS

Machine-learning algorithms were effective in predicting ambulatory status following surgery for spinal metastasis. Based on our data, the extreme gradient boosting and decision tree best predicted postoperative ambulatory status 180 and 90 days after spinal metastasis surgery, respectively.

Cost-utility Analysis of Anterior Cervical Discectomy and Fusion for Cervical Spondylosis Patients Comparing Polyetheretherketone Versus Tricortical Iliac Crest Bone Graft

STUDY DESIGN

Prospective cohort study.

OBJECTIVES

To perform a cost-utility analysis and to investigate the clinical outcomes and patient's quality of life after anterior cervical discectomy and fusion (ACDF) to treat cervical spondylosis compared between fusion with polyetheretherketone (PEEK) and fusion with tricortical iliac bone graft (IBG) in Thailand.

SUMMARY OF BACKGROUND DATA

ACDF is one of the standard treatments for cervical spondylosis. The fusion material options include PEEK and tricortical IBG. No previous studies have compared the cost-utility between these 2 fusion material options.

PATIENTS AND METHODS

Patients with cervical spondylosis who were scheduled for ACDF at Siriraj Hospital (Bangkok, Thailand) during 2019-2020 were prospectively enrolled. Patients were allocated to the PEEK or IBG fusion material group according to the patient's choice of fusion material. EuroQol-5 dimensions 5 levels and relevant costs were collected during the operative and postoperative periods. A cost-utility analysis was performed using a societal perspective. All costs were converted to 2020 United States dollars (USD), and a 3% discount rate was used. The outcome was expressed as the incremental cost-effectiveness ratio.

RESULTS

Thirty-six patients (18 ACDF-PEEK and 18 ACDF-IBG) were enrolled. Except for Nurick grading, there was no significant difference in patient baseline characteristics between groups. The average utility at 1 year after ACDF-PEEK and ACDF-IBG were 0.939 ± 0.061 and 0.798 ± 0.081, respectively ( P < 0.001). The total lifetime cost of ACDF-PEEK and ACDF-IBG was 83,572 USD and 73,329 USD, respectively. The incremental cost-effectiveness ratio of ACDF-PEEK when compared with that of ACDF-IBG showed a gain of 4468.52 USD/quality-adjusted life-years, which is considered cost-effective at the Thailand willingness-to-pay threshold of 5115 USD/quality-adjusted life-year gained.

CONCLUSIONS

ACDF-PEEK was found to be more cost-effective than ACDF-IBG for treating cervical spondylosis in Thailand.

LEVEL OF EVIDENCE

Level II.

Relationship between gait parameter and spinal sagittal profiles in asymptomatic subjects

BACKGROUND

To study the gait parameters in asymptomatic volunteers and investigate the correlation between the gait and several radiographic sagittal profiles.

METHODS

Asymptomatic volunteers (20-50 years of age) were included and allocated into three subgroups depending on pelvic incidence (low, normal, and high). Standing whole spine radiographs and gait analysis data were obtained. The Pearson Coefficient Correlation was used to determine the relationship between the gait and radiographic profiles.

RESULTS

A total of 55 volunteers (28 male and 27 females) were included. The mean age was 27.35 ± 6.37 years old. The average sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), and PI-LL mismatch (PI-LL) were 37.78 ± 6.59, 14.51 ± 9.19 degrees, and 52.29 ± 10.87 degrees and - 0.36 ± 11.41, respectively. The mean velocity and stride of all the volunteers were 119.00 ± 30.12 cm/s and 130.25 ± 7.72 cm, correspondingly. The correlation between each of the radiographical and gait parameters was low (ranging from - 0.24 to 0.26).

CONCLUSION

Gait parameters were not differenced significantly between each of the PI subgroups in asymptomatic volunteers. Spinal sagittal parameters also showed a low correlation with gait parameters.

The Role and Clinical Outcomes of Endoscopic Spine Surgery of Treating Spinal Metastases; Outcomes of 29 Cases From 8 Countries

OBJECTIVE

We aim to report the outcomes and feasibility of endoscopic spine surgery used to treat symptomatic spinal metastases patients. This is the most extensive series of spinal metastases patients who underwent endoscopic spine surgery.

METHODS

A worldwide collaborative network group of endoscopic spine surgeons, named 'ESSSORG,' was established. Patients diagnosed with spinal metastases who underwent endoscopic spine surgery from 2012 to 2022 were retrospectively reviewed. All related patient data and clinical outcomes were gathered and analyzed before the surgery and the followtime period of 2 weeks, 1 month, 3 months, and 6 months.

RESULTS

A total of 29 patients from South Korea, Thailand, Taiwan, Mexico, Brazil, Argentina, Chile, and India, were included. The mean age was 59.59 years, and 11 of them were female. The total number of decompressed levels was 40. The technique was relatively equal (15 uniportal; 14 biportal). The average length of admission was 4.41 days. Of all patients with an American Spinal Injury Association Impairment Scale of D or lower before surgery, 62.06% reported having at least one recovery grade after the surgery. Almost all clinical outcomes parameters statistically significantly improved and maintained from 2 weeks to 6 months after the surgery. Few surgical-related complications (4 cases) were reported.

CONCLUSION

Endoscopic spine surgery is a valid option for treating spinal metastases patients as it could yield comparable results to other minimally invasive spine surgery techniques. As the aim is to improve the quality of life, this procedure is valuable and holds value in palliative oncologic spine surgery.

Comparative effectiveness of different pedicle screw density patterns in spinal deformity correction of small and flexible operative adolescent idiopathic scoliosis: inverse probability of treatment weighting analysis

PURPOSES

An optimal pedicle screw density for spinal deformity correction in adolescent idiopathic scoliosis (AIS) remains poorly defined. We compared radiographic correction, operative time, estimated blood loss, and implant cost among different screw density patterns in operatively treated AIS patients.

METHODS

A retrospective observational cohort study of AIS patients who underwent posterior spinal fusion using all-pedicle screw instrumentation was conducted from January 2012 to December 2018. All patients were categorized into three different pedicle screw density groups: the very low density (VLD), the low density (LD), and the high density (HD) group. The comparative effectiveness between each pairwise comparison was performed under the inverse probability of the treatment weighting method to minimize the possible confounders imbalance among treatment groups. The primary endpoints in this study were the degrees of correction and deformity progression at 2 years postoperatively.

RESULTS

A total of 174 AIS patients were included in this study. The adjusted treatment effects demonstrated similar degrees of deformity correction after 2 years in the three treatment groups. However, the VLD and LD group slightly increased the curve progression at 2 years compared to the HD group by 3.9° (p = 0.005) and 3.2° (p = 0.044), respectively. Nevertheless, the limited screw density patterns (VLD and LD) significantly reduced the operative time, estimated blood loss, and implant cost per operated level.

CONCLUSION

The limited pedicle screw pattern (VLD and LD) in relatively flexible AIS spinal deformity correction results in similar coronal and sagittal radiological outcomes while reducing operative time, estimated blood loss, and implant cost compared to the high-density pedicle screw instrumentation.

Surgical outcome of scoliosis in patients with Marfan syndrome

PURPOSE

To evaluate clinical and radiographic outcomes after surgical scoliosis correction and posterior instrumented fusion in SMF patients.

METHODS

A single-center medical database was reviewed to identify MF patients who presented with scoliosis from 2000 to 2015. Patients who underwent spinal fusion surgery were included. Demographic, operative and clinical data were reviewed, and the preoperative, postoperative, and latest follow-up radiographic parameters were compared.

RESULTS

Twelve patients were identified (2 males, 10 females) with an average age at surgery of 14.4 ± 2.6 years. Comorbidities were found in 84.6%. Most patients (90.9%) presented with a right thoracic curve. The average preoperative Cobb angle was 75.6 ± 15.5 degrees. Posterior instrumented spinal fusion was performed in all patients (1 hook/pedicular screw and 11 pedicle screws only). The average follow-up period was 6.8 ± 3.1 years. The mean postoperative Cobb angle after surgery and at the final follow-up was 33.4 ± 18.0 degrees and 35.5 ± 18.4 degrees, respectively. There was a statistically significant difference among the preoperative and postoperative Cobb angles (p < 0.001), but no significant difference among the sagittal angles. Two perioperative complications including superficial wound infection and broken rods were observed.

CONCLUSIONS

Posterior scoliosis correction and instrumented spinal fusion resulted in a satisfactory outcome in MF patients. Perioperative complications are not uncommon; however, no neurological complication or spinal decompensation was observed in this study.

LEVEL OF EVIDENCE

IV.

Hidden Neuropathic Pain in Chronic Low Back Pain: Prevalence, Pattern, and Impact on Quality of Life

Objective: A patient with Neuropathic Pain (NP) may suffer from pure NP or may have mixed nociceptive and neuropathic pain. No previous study has investigated NP among Thai patients with Chronic Low Back Pain (CLBP). This study aimed to investigate the prevalence and clinical presentation of NP, and the impact of NP on Quality of Life (QoL) in Thai Chronic Low Back Pain (CLBP) patients.Materials and Methods: Adult patients with CLBP longer than 3 months were included. NP was detected by painDETECT questionnaire, and NP was defined as a score 19. Demographic data, pain characteristics, treatment, Oswestry Disability Index (ODI), and quality of life score (Short Form 36, SF-36) were recorded.Results: 371 CLBP patients were enrolled. The overall prevalence of neuropathic pain was 50.1% (95% CI: 44.9-55.3%). The prevalence of NP in patients with axial low back pain, back pain with pain radiating above the knee, and back pain with pain radiating below the knee was 28.3%, 58.21%, and 59.5%, respectively. Only 48.9% of patients with NP received neuropathic pain medication. Multivariate analysis showed only older age to be associated with NP (OR: 1.017, 95% CI: 1.002-1.033). NP patients had a significantly higher ODI score. There is no difference in most dimension of SF-36 scores, except marginally higher general health and vitality dimension scores.Conclusion: Prevalence of NP in Thai CLBP patients is high. Additionally, it is undertreated and associated with higher disability especially among patients with radiating pain above the knee. Older age is an independent predictor of NP.

Cost-Utility Analysis Compared Between Radiotherapy Alone and Combined Surgery and Radiotherapy for Symptomatic Spinal Metastases in Thailand

Objective

To investigate the patient quality of life and cost-utility compared between radiotherapy alone and combined surgery and radiotherapy for spinal metastasis (SM) in Thailand.

Methods

Patients with SM with an indication for surgery during 2018–2020 were prospectively recruited. Patients were assigned to either the combination surgery and radiotherapy group or the radiotherapy alone group. Quality of life was assessed by EuroQol-5D-5L (EQ-5D-5L) questionnaire, and relevant healthcare costs were collected pretreatment, and at 3-month and 6-month posttreatment. Total lifetime cost and quality-adjusted life-years (QALYs) were estimated for each group.

Results

Twenty-four SM patients (18 females, 6 males) were included. Of those, 12 patients underwent combination treatment, and 12 underwent radiotherapy alone. At 6-month posttreatment, 10 patients in the surgery group, and 11 patients in the nonsurgery group remained alive for a survival rate of 83.3% and 91.7%, retrospectively. At 6-month posttreatment, the mean utility in the combination treatment group was significantly better than in the radiotherapy alone group (0.804 ± 0.264 vs. 0.518 ± 0.282, respectively; p = 0.011). Total lifetime costs were 59,863.14 United States dollar (USD) in the combination treatment group and 24,526.97 USD in the radiation-only group. The incremental cost-effectiveness ratio using 6-month follow-up data was 57,074.01 USD per QALY gained.

Conclusion

Surgical treatment combined with radiotherapy to treat SM significantly improved patient quality of life compared to radiotherapy alone during the 6-month posttreatment period. However, combination treatment was found not to be cost-effective compared to radiotherapy alone for SM at the Thailand willingness-to-pay threshold of 5,113 USD/QALY.

Postoperative outcomes of subaxial cervical spine metastasis: Comparison among the anterior, posterior, and combined approaches

•

The combined therapy produced better clinical results and a longer survival.

•

Perioperative complications are significantly higher with combined approach.

•

Anterior and posterior approach have the same neurological improvement rate.

Background

The incidence of subaxial spinal metastases increases due to longer life expectancy resulting from successful modern cancer treatments. The three most utilized approaches for surgical treatment include the anterior, posterior, and combined approaches. However, despite increasing surgical volume, data on the postoperative complication profiles of different operative approaches for this patient population is scarce.

Methods

The institutional databases of two large referral centers in Thailand were retrospectively reviewed. Patients with subaxial cervical spine metastasis who underwent cervical surgery during 2005 to 2015 were identified and enrolled. Clinical presentations, baseline characteristics, operative approach, perioperative complications, and postoperative outcomes, including pain, neurological recovery, and survival, were compared among the three surgical approaches.

Results

The 70 patients (44 with anterior approach, 14 with posterior approach, 12 with combined approach) were enrolled. There were no statistically significant differences in preoperative characteristics, including Charlson Comorbidity Index (CCI), Tomita score, and Revised Tokuhashi score, among the three groups. There were no significant differences among groups for medical complications, surgical complications, neurological recovery, verbal pain score improvement, survival time, or ambulatory status improvement. However, the combined approach did show a significantly higher rate of overall perioperative complications (p = 0.01), intraoperative blood loss (p < 0.001), and operative time (p < 0.001) compared to the other two approaches.

Conclusions

Patients in the combined approach group had the highest rates of perioperative complications. However, although the differences were not statistically significant, patients in the combined group tended to have better clinical outcomes after follow-up and the longest survival time.

Pigmented epithelioid melanocytoma (PEM) of the spine with compression fracture: case report

Background

Pigmented epithelioid melanocytoma (PEM) is a sporadic type of pigmented melanocytic tumor with uncertain malignant potential. PEM arises as a solitary neoplasm that predominantly occurs spontaneously in otherwise healthy patients. Due to its rarity, a gold standard treatment regimen does not exist; however, symptomatic cases should be managed with radiotherapy and surgery.

Case presentation

A 28-year-old Thai female presented with a sudden onset of back pain and weakness of the lower extremities during the postpartum period. Magnetic resonance imaging demonstrated abnormal soft tissue formation from T4 to T7; it extended to the vertebral bodies, left neural foramina, and posterior columns of T6 and T7. The patient underwent complete tumor debulking, decompressive laminectomy from T4 to T8, and posterior instrumentation from T3 to T10. The histopathology and immunohistochemistry suggested PEM. The patient fully resolved back pain after surgery. Nevertheless, as the patient re-presented with a neurological deficit a few months after the operative intervention, it was decided to perform a surgical resection via an en bloc vertebrectomy. At the one-year follow-up, although the patient reported continued improvement of her back pain, there was no motor power improvement.

Conclusions

Spinal cord compression due to PEM is uncommon, especially in adults. Early diagnosis and treatment provide a good prognosis and help to regain lost neurological functions. Complete tumor removal and decompression of the spinal cord must be considered as a treatment strategy. Perioperative radiotherapy and chemotherapy have also been highlighted as treatment modalities for spinal tumors. With our reported case, early operative intervention coupled with radiotherapy produced satisfying outcomes.

Epidemiologic Study of Operative Treatment for Spinal Metastasis in Thailand : A Review of National Healthcare Data from 2005 to 2014

Objective

To study the factors relating to operative treatment for spinal metastasis in Thailand during 2005-2014 and to determine the hospital costs, mortality rate, and incidence of perioperative complication.

Methods

Inpatient reimbursement data from 2005 to 2014 was reviewed from three national healthcare organizations, including the National Health Security Office, the Social Security Office, and the Comptroller General's Department. The search criteria were secondary malignant neoplasm of bone and bone marrow patients (International Classification of Diseases 10th revision, Thai modification codes [ICD 10-TM], C79.5 and C79.8) who underwent spinal surgical treatment (ICD 9th revision, clinical modification procedure with extension codes [ICD 9-CM], 03.0, 03.4, 03.09, and 81.0) during 2005-2014. Epidemiology, comorbidity, and perioperative complication were analyzed.

Results

During the study period, the number of spinal metastasis patients who underwent operative treatment was significantly increased from 0.30 to 0.59 per 100000 (p<0.001). More males (56.14%) underwent surgical treatment for spinal metastasis than females. The most common age group was 45-64 (55.1%). The most common primary tumor sites were the unknown origin, lung, breast, prostate, and hepatocellular/bile duct. Interestingly, the proportion of hepatocellular/bile duct, breast, and lung cancer was significantly increased (p<0.001). The number of patients who had comorbidity or in-hospital complication significantly increased over time (p<0.01); however, the in-hospital mortality rate decreased.

Conclusion

During the last decade, operative treatment for spinal metastasis increased in Thailand. The overall in-hospital complication rate increased; however, the in-hospital mortality rate decreased.

Validity and reliability of the Thai version of the Spine Oncology Study Group Outcomes Questionnaire version 2.0 to assess Quality of Life in Patients with Spinal Metastasis

BACKGROUND CONTEXT

The Spine Oncology Study Group Outcomes Questionnaire version 2.0 (SOSGOQ2.0) is a spinal metastasis (SM)-specific quality of life (QoL) questionnaire that was previously reported to have good reliability and validity. There is currently no Thai version of the SOSGOQ 2.0. (TH-SOSGOQ2.0).

PURPOSE

To assess the psychometric properties of the TH-SOSGOQ 2.0.

STUDY DESIGN/SETTING

Cross-sectional study. Faculty of Medicine Siriraj Hospital, Mahidol University.

PATIENT SAMPLE

Patients who were confirmed diagnosis of metastatic spinal disease, age 18 to 75 years, and having already undergone surgery and/or radiotherapy for the treatment of spinal metastasis.

OUTCOME MEASURES

Validity and reliability of the TH-SOSGOQ 2.0 to assess QoL in Patients with SM.

METHODS

Using the forward-backward translation technique, the SOSGOQ2.0 was translated into Thai language to create the TH-SOSGOQ2.0. SM patients were prospectively enrolled and evaluated for patient QoL using both the TH-SOSGOQ2.0 and the EQ-5D-5L (Thai version) at baseline and 3 months after treatment. Construct validity was assessed using multi-trait scaling analysis, confirmatory factor analysis, and correlation with EQ-5D-5L. Test-retest reliability was assessed in a subgroup of patients who took the TH-SOSGOQ2.0 two times one week apart.

RESULTS

Sixty-eight patients (mean age: 57 years; 30 males, 38 females) were included. The Cronbach's alpha values for the total score, physical function, neurological function, pain, mental health, social function, and post-therapy domains were 0.87, 0.89, 0.91, 0.84, 0.82, 0.75, and 0.85, respectively. Good reliability was demonstrated (interclass correlation coefficient range: 0.70-0.84), except for the social function domain (0.60). Regarding concurrent validity, the TH-SOSGOQ2.0 domains demonstrated moderate to good correlation with the corresponding EQ-5D-5L 9 (Thai version) domains (range: -0.32 to -0.78). Physical function was the most well-correlated domain with the EQ-5D-5L (Thai version) (-0.77).

CONCLUSIONS

TH-SOSGOQ2.0 demonstrated good reliability and validity for assessing QoL in Thai SM patients.

Non-fusion palliative spine surgery without reconstruction is safe and effective in spinal metastasis patients: retrospective study

Considering the shorter life expectancy and poorer prognosis of metastatic epidural spinal cord compression patients, anterior reconstruction and fusion may be unnecessary. This study aimed to investigate the outcomes of palliative surgery for metastatic epidural spinal cord compression with neurological deficit among patients who underwent posterior decompression and instrumentation without fusion or anterior reconstruction. This single-center retrospective review included all patients aged > 18 years with thoracic or lumbar spinal metastasis who were surgically treated for metastatic spinal cord compression without fusion or anterior reconstruction at the Department of Orthopaedic Surgery, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand during July 2015 to December 2017. Data from preoperation to the 1-year follow-up, including demographic and clinical data, Frankel classification, pain scores, complication, revision surgery, health-related quality-of-life scores, and survival data, were collected and analyzed. A total of 30 patients were included. The mean age was 59.83 ± 11.73 years, and 20 (66.7%) patients were female. The mean operative time was 208.17 ± 58.41 min. At least one Frankel grade improvement was reported in 53.33% of patients. The pain visual analog scale, the EuroQOL five-dimension five-level utility score, and the Oswestry Disability Index were all significantly improved at a minimum of 3 months after surgery. No intraoperative mortality or instrument-related complication was reported. The mean survival duration was 11.4 ± 8.97 months. Palliative non-fusion surgery without anterior reconstruction may be considered as a preferable choice for treating spinal metastasis patients with spinal cord compression with neurological deficits.

Goal-Directed Fluid Therapy Based on Pulse-Pressure Variation Compared with Standard Fluid Therapy in Patients Undergoing Complex Spine Surgery: A Randomized Controlled Trial

Study Design

Prospective, randomized, controlled study.

Purpose

To determine whether the use of goal-directed fluid therapy (GDT) guided by pulse-pressure variation (PPV) and fluid management protocol can reduce intraoperative hypotension, blood transfusion requirements, and postoperative complications in adults undergoing complex spine surgery.

Overview of Literature

Complex spine surgeries involve a significant risk of blood loss and intraoperative hypotension. Previous studies showed that GDT reduces intraoperative hypotension and postoperative complications in these surgery types; however, limited information exists about GDT guided by PPV.

Methods

Sixty adults (18–70 years) patients undergoing complex spine surgeries at Siriraj Hospital, Mahidol University, Thailand were enrolled. Patients were allocated to two groups (30 patients in each) using computer-generated randomization. Intraoperative fluid and vasopressor were administrated via either GDT or standard care. The GDT algorithm used PPV and fluid protocol as the primary tool to guide hemodynamic management. The incidences and episodes of perioperative hypotension were measured as the outcomes.

Results

Fifty-seven patients were analyzed (three patients in the GDT group were excluded). The baseline characteristics and surgical procedures of the two groups did not differ significantly. The prevalence of intraoperative hypotension was 80.0% for the control group and 66.7% for the GDT group (p=0.25). Two episodes (1–3) of intraoperative hypotension occurred in the control group, and one episode (0–3) occurred in the GDT group; the difference was not significantly different (p=0.57). The intraoperative blood transfusion requirements and postoperative complications were similar in both the groups. In the subgroup analysis, patients with intraoperative hypotension exhibited a higher incidence of postoperative bowel dysfunction.

Conclusions

PPV-guided GDT and fluid protocol, as compared with standard practice, did not show significant advantages with respect to intraoperative hypotension, blood transfusion, or postoperative complications in patients undergoing complex spine surgery in the prone position.

Reliability and Validity of the Thai Version of the Swiss Spinal Stenosis Questionnaire

The original Swiss Spinal Stenosis (SSS) questionnaire was translated into the Thai version and culturally adapt for use in Thailand. The Thai version—SSS is valid and reliable to use in both clinical and research to address the functional, symptom severity, and satisfaction in Thai lumbar spinal stenosis patients.

Study Design..

Cross-sectional study.

Objective..

To evaluate the reliability and validity of the Thai version of the Swiss Spinal Stenosis (SSS) questionnaire.

Summary of Background Data..

The SSS questionnaire was developed to assess symptom severity, physical functional status, and patient satisfaction in spinal stenosis patients that was previously reported to have good reliability and validity. There is currently no Thai version of the SSS questionnaire.

Methods..

The SSS questionnaire was translated into Thai language to create the Thai version of the Swiss Spinal Stenosis (Thai-SSS) questionnaire. Translation was performed according to international standards using a forward-backward translation protocol. Translation was performed by two expert translators and one physician, and the final version was approved by an expert committee. Thai patients with degenerative lumbar spinal stenosis were enrolled and evaluated using the Thai-SSS questionnaire, the Thai version of the Short Form-36 (SF-36), and a visual analogue scale (VAS) before and after treatment. Reliability and validity of the Thai-SSS were assessed via comparison with the SF-36 and the VAS.

Results..

One hundred seven patients were included. Eighty patients underwent decompression and fusion surgery, and the others underwent decompression alone. Cronbach's alpha of all domains of the Thai-SSS showed excellent internal consistency (0.869–0.921). The intraclass correlation coefficient for test–retest reliability was 0.77 (95% CI: 0.65–0.85). Regarding concurrent validity, the physical function scale of the Thai-SSS was strongly correlated with the physical functioning domain of the SF-36 (r = 0.70). The symptom severity domain of the Thai-SSS was strongly correlated with the bodily pain domain of the SF-36 and the VAS (r = 0.76 and 0.78, respectively).

Conclusion..

The Thai-SSS was found to be a valid and reliable tool for evaluating symptom severity, physical function, and patient satisfaction after treatment in Thai patients with spinal stenosis.

Level of Evidence: 4

Nonfusion Muscle-Sparing Technique to Treat Long-Segment Thoracolumbar Extradural Arachnoid Cyst in a Child: A Case Report and Review of the Literature

BACKGROUND

Spinal extradural arachnoid cyst is an uncommon cause of spinal cord compression. It results from a small dural defect that leads to cerebrospinal fluid (CSF) accumulation in the cyst and subarachnoid space, and the cyst can compress the spinal cord and nerve roots. Surgery is the treatment of choice in symptomatic patients, and most cases have an immediately satisfying outcome after surgery.

CASE DESCRIPTION

A 10-year-old Thai boy presented with progressive weakness in both legs. Magnetic resonance imaging (MRI) demonstrated a giant cystic lesion 23 cm in length from T1-L2 level. To our knowledge, this is the longest arachnoid cyst that has been reported in children. The operation included unilateral paraspinal muscle dissection with spinous process translation techniques, T1-L4 laminectomy, total cyst excision, and dural defect repair at the T4 level. The symptoms were fully resolved within 2 months after surgery. However, thoracic kyphosis was slightly increased, but the patient still has a normal sagittal profile.

CONCLUSIONS

Spinal arachnoid cyst is rare, especially in children. Early diagnosis and treatment are essential for improving the chance of full recovery, and for avoiding complication and irreparable defect. Total cyst removal with dural repair remains the best treatment alternative; however, potential complications, especially spinal malalignment after extensive laminectomy, must be considered. Postoperative MRI showed normal CSF flow and no spinal cord compression. The muscle-sparing technique with multiple-level laminectomy without spinal fusion that we used in this case provided a satisfying outcome.

The Role of Calcium Pyrophosphate Dihydrate Deposition in the Postoperative Outcome of Lumbar Spinal Stenosis Patients

Study Design

Retrospective study.

Purpose

This study aimed to investigate the association of surgical intervention with clinical and quality of life (QoL) outcomes in patients who underwent posterior spinal surgery for lumbar spinal stenosis (LSS) with spinal calcium pyrophosphate dihydrate deposition (SCPPD) versus that in those who underwent the surgery for LSS without SCPPD.

Overview of Literature

Calcium pyrophosphate (CPP)-associated arthritis is one of the most common types of arthritis. The clinical outcomes are well studied in CPP-associated arthritis of the appendicular joints. However, few studies have investigated SCPPD.

Methods

A single-institution database was reviewed. LSS patients were categorized as those who did and did not have SCPPD, based on histologic identification. Clinical presentations and postoperative results were analyzed. Disability and QoL were assessed using the Oswestry Disability Index (ODI) and the 36-item Short-Form Health Survey.

Results

Thirty-four patients were enrolled, with 18 patients being allocated to the SCPPD group and 16 being allocated to the non- SCPPD group. Preoperative and postoperative pain scores were not significantly different between the groups (p=0.33 and p=0.48, respectively). The average preoperative ODI score in the SCPPD group was slightly higher than that in the non-SCPPD group (57 vs. 51, p=0.33); however, the postoperative ODI score was significantly lower (15 vs. 43, p=0.01). The postoperative physical function, vitality, and mental health of the SCPPD patients were also significantly improved (p=0.03, p=0.022, and p=0.022, respectively).

Conclusions

Surgical intervention resulted in good clinical outcomes in SCPPD patients. As per our findings, total removal of CPPinvolved tissue is unnecessary. As such, surgery should be performed as indicated according to clinical presentation without considering the presence of CPPD.

Allogeneic red cell transfusion and its influence on relevant humoral and cellular immunological parameters: A prospective observational trial

BACKGROUND

It is assumed that transfusion of allogeneic red cells is associated with increased peri-operative mortality and morbidity. Also assumed is the theory of transfusion-related immunomodulation.

OBJECTIVE

The aim of this study was to investigate the hypothesis that red cell transfusion specifically leads to an immunological response in surgical patients.

DESIGN

Prospective observational study.

SETTING

Departments of Orthopedic Surgery and Anaesthesia, University Hospital, Thailand.

PATIENTS

Low-risk, noncancer patients, aged 18 to 75 years undergoing elective major spine surgery, with and without red cell transfusion therapy.

INTERVENTIONS

Blood specimens were withdrawn four times (prior to surgery and on days 1, 3 and 5).

MAIN OUTCOME MEASURES

Assessment of immunocompetent cells and cytokines in transfused and nontransfused patients using flow cytometry and multiplex ELISA.

RESULTS

From a total of 78 patients, 61 met the requirements and were analysed in three groups: 19 with no transfusion and 26 and 16 transfused intra-operatively and on day 1 or 2, respectively. No patient experienced peri-operative haemorrhage. Postoperative infection or thrombosis occurred in 5.5% of nontransfused patients and 16.6% of transfused patients; the difference was not significant. There was no significant immunomodulatory effect of red cell transfusion: of 45 immunological parameters, only five little-relevant cytokines were significantly affected, although slightly and nonspecifically.

CONCLUSION

Our data indicate that red cell transfusion alone does not create an immunological response in otherwise healthy surgical patients. Our findings do not generally contradict the transfusion-related immunomodulation phenomenon, which has, however, primarily been observed in patients with an already weakened or procedure-deteriorated immune system, such as from malignant disease, significant comorbidity, extensive abdominal/thoracic surgery and cardiopulmonary bypass.

TRIAL REGISTRATION

The study was registered on 15 May 2014, before enrolment of the first patient, at www.ClinicalTrials.gov, NCT02140216.

Prognostic factors in patients with spinal metastasis: a systematic review and meta-analysis

BACKGROUND CONTEXT

Incidence of symptomatic spinal metastasis has increased owing to improvement in treatment of the disease. One of the key factors that influences decision-making is expected patient survival. To our knowledge, no systematic reviews or meta-analysis have been conducted that review independent prognostic factors in spinal metastases.

PURPOSE

This study aimed to determine independent prognostic factors that affect outcome in patients with metastatic spine disease.

STUDY DESIGN

This is a systematic literature review and meta-analysis of publications for prognostic factors in spinal metastatic disease.

PATIENT SAMPLE

Pooled patient results from cohort and observational studies.

OUTCOME MEASUREMENT

Meta-analysis for poor prognostic factors as determined by hazard ratio (HR) and 95% confidential interval (95% CI).

METHODS

We systematically searched relevant publications in PubMed and Embase. The following search terms were used: ("'spinal metastases'" OR "'vertebral metastases'" OR ""spinal metastasis" OR 'vertebral metastases') AND ('"prognostic factors"' OR "'survival'"). Inclusion criteria were prospective and retrospective cohort series that report HR and 95% CI of independent prognostic factors from multivariate analysis. Two reviewers independently assessed all papers. The quality of included papers was assessed by using Newcastle-Ottawa Scale for cohort studies and publication bias was assessed by using funnel plot, Begg test, and Egger test. The prognostic factors that were mentioned in at least three publications were pooled. Meta-analysis was performed using HR and 95% CI as the primary outcomes of interest. Heterogeneity was assessed using the I² method.

RESULTS

A total of 3,959 abstracts (1,382 from PubMed and 2,577 from Embase) were identified through database search and 40 publications were identified through review of cited publications. The reviewers selected a total of 51 studies for qualitative synthesis and 43 studies for meta-analysis. Seventeen poor prognostic factors were identified. These included presence of a neurologic deficit before surgery, non-ambulatory status before radiotherapy (RT), non-ambulatory status before surgery, presence of bone metastases, presence of multiple bone metastases (>2 sites), presence of multiple spinal metastases (>3 sites), development of motor deficit in <7 days before initiating RT, development of motor deficit in <14 days before initiating RT, time interval from cancer diagnosis to RT <15 months, Karnofsky Performance Score (KPS) 10-40, KPS 50-70, KPS<70, Eastern Cooperative Oncology Group (ECOG) grade 3-4, male gender, presence of visceral metastases, moderate growth tumor on Tomita score (TS) classification, and rapid growth tumor on TS classification.

CONCLUSIONS

Seventeen independent poor prognostic factors were identified in this study. These can be categorized into cancer-specific and nonspecific prognostic factors. A tumor-based prognostic scoring system that combines all specific and general factors may enhance the accuracy of survival prediction in patients with metastatic spine disease.

L4-L5 Total Dislocation with Cauda equina Syndrome: A Case Report

BACKGROUND

There are very few reports in the literature that describe total anterolateral fracture dislocation of L4 and L5. To present a case report of L4-L5 total dislocation with major neurological deficit and open fracture of left distal femur.

CASE REPORT

A 45-year-old Thai woman was transported to hospital with severe trauma, low back pain, a shallow lacerated wound on her back, and ecchymosis around waist and trunk. Closed reduction was initially performed and followed with posterior decompression, fusion, and instrumentation with pedicular screws and rod systems from L3-S1. Open reduction and internal fixation of distal femur was then performed.

CONCLUSION

At 1-year follow-up, the patient could ambulate with left ankle-foot orthosis (AFO) using a walker.

Cefazolin-related fever in postoperative spine surgery: a case report

BACKGROUND

There have been few reports describing antibiotic related fever especially in the beta-lactam class of antibiotics. The present report is a case of postoperative immediate-onset cefazolin-related fever in a lumbar spine surgery patient.

CASE REPORT

A 58-year-old woman presented with progressive low back pain and neurogenic claudication of both extremities for six months. Magnetic resonance imagese (MRI) of the lumbar spine indicated central canal stenosis with nerve root compression from L4 to S1. After decompressive laminectomy, pedicular screw fixation, and posterolateral fusion were performed, the patient experienced-postoperative fever without obvious evidence of infection. The blood and tip of drain bacterial culture grew no organisms. After propholactic cefazolin was discontinued in postoperative day 5, the fever began to declined and returned to normal on postoperative day 9.

CONCLUSION

Postoperative drug fever that is caused by prophylactic cefazolin may be delayed in diagnosis because drug fever is usually diagnosed by exclusion after the elimination of other potential causes. The research authors would like to encourage physicians to be aware of this entity. Prompt cause identification can obviate unnecessary diagnostic procedures and inappropriate treatments.

The effect of epidural low-dose morphine-soaked microfibrillar collagen sponge in postoperative pain control after laminectomy and instrumented fusion: a randomized double-blind placebo-controlled study

OBJECTIVE

To evaluate the postoperative analgesic effect and postoperative nausea and vomiting (PONV) after using epidural low-dose morphine-soaked microfibrillar collagen sponge (MMCS), as compared with placebo.

MATERIAL AND METHOD

A prospective randomized double-blind placebo-controlled study was performed on patients under-going single-level posterior lumbar spinal decompression and instrumented fusion at the Department of Orthopedic Surgery, Siriraj Hospital, between August 2012 and December 2013. Patients were randomly allocated into two groups to receive either an epidural MMCS or an epidural normal saline-soaked microfibrillar collagen sponge (placebo). Intensity ofpain, PONV and total amount of morphine were recorded at 4, 24, 48, and 72 hours, postoperatively.

RESULTS

The analgesic effect was enhanced significantly in the epidural MMCS group, as the amount ofmorphine used was statistically less than in the placebo group at 4 and 24 hours (p < 0.05).

CONCLUSION

A single low-dose epidural MMCS is effectiveforpain control after posterior lumbar spinal surgery with a low incidence of PONV.

Incidence of symptomatic pulmonary embolism in spinal surgery

BACKGROUND

Pulmonary embolism (PE) is a serious condition in orthopedic surgery. The incidence of PE, which is a sequelae of VTE in spinal surgery, is quite low. In the limited available published data, incidence rates of PE in spinal surgery are comparable to that of hip or knee arthroplasty surgery. The role of pharmacologic thomboprophylaxis remains controversial in spinal surgery.

OBJECTIVE

The present study was designed to evaluate the incidence of symptomatic pulmonary embolism in spinal surgery at a single tertiary care institute.

MATERIAL AND METHOD

A retrospective study of the medical records of patients that were diagnosed with symptomatic pulmonary embolism in spinal surgery from 2002-2012. The reviewed data were retrieved from the database of the Faculty of Medicine Siriraj Hospital, Mahidol University in Bangkok, Thailand.

RESULTS

Three cases of symptomatic pulmonary embolism were found from 9,184 spinal surgery cases. The incidence rate was 0.033%. There were two patients with lumbar spine surgery and one case with thoracolumnbar surgery. All three cases had different underlying conditions, operations, and clinical course. One case of fatal pulmonary embolism was found in our study.

CONCLUSION

Although there is a very low incidence of symptomatic pulmonary embolism, this is a catastrophic condition for affected patients and their families. PE can occur in spinal surgery cases at all levels of severity and complexity, even with no apparent risk factors.

Prevalence of primary spinal tumors: 15-year data from Siriraj Hospital

OBJECTIVE

To determine prevalence, demographic data and clinical presentation of primary vertebral tumors.

MATERIAL AND METHOD

A retrospective study of the primary spine tumor specimens from Siriraj bone tumor registry from 1996 to 2010.

RESULTS

From the study, primary spinal tumors constituted 85 of 1,679 bone tumor cases (5.06%). The common benign spinal tumors were giant cell tumor and hemangioma. The common malignant spinal tumors were chordoma, chondrosarcoma, and osteosarcoma. The mean age ofpresentation was 44.68 years. Fifty-three percent of tumors occurred in females. Pain was the most common presenting symptom, occurring in 73.53% of malignant and 52.94% of benign tumors. Neurological involvement occurred in 25% of malignant tumor Malignant lesions predominated in the sacral region while the most common location ofbenign specimens was thoracic region.

CONCLUSION

The present study was the first demographic study ofprimary spinal tumor in Thai showed variety of prevalence when compared with similar studies based on Western patients. Whether these results reflect differences in the population, race and data collection method.

Cervical myelopathy from retro-odontoid calcium pyrophosphate dihydrate mass: a case report

Calcium pyrophosphate dihydrate (CPPD) crystal deposition disease is one of the most common forms of crystal-associated arthropathy in the elderly. However, cervical spine is rarely affected, especially in upper cervical area. There have been previous reported cases of symptomatic retro-odontoid CPPD deposition disease in English literature but this case is the first reported in Thai patients. This is a case report of a 67-year-old man who presented with neck pain with progressive myelopathy. Neurologic examination demonstrated a cervical myelopathy with muscle weakness and sensory disturbance of both extremities. Imaging studies showed extradural retro-odontoid mass compressing the spinal cord. The patient underwent occiput to C3 fusion with plating, posterior arch of atlas resection, transoral odontoidectomy, and mass removal. Histological examination of the mass revealed fibrocartilage tissue and rhomboid shaped crystals that showed positive biferingent in polarized light microscopy consistent with CPPD crystals. After surgery, no complication was found, and his neurological function had improved.