Tomas Zamora

The Spine Instability Neoplastic Score: an independent reliability and reproducibility analysis.

BACKGROUND Metastatic vertebral instability has not yet been clearly defined in the literature; there still exists a paucity of reliable criteria to assess the risk of vertebral collapse. PURPOSE We performed an independent interobserver and intraobserver agreement evaluation of the Spine Instability Neoplastic Score (SINS) and correlated the score with selected clinical cases and the treatment they received. STUDY DESIGN Independent reliability study for the newly created SINS. PATIENT SAMPLE Thirty patients who underwent either radiotherapy alone or surgery followed by radiotherapy were randomly selected from the orthopedic surgery and radiotherapy departments databases. OUTCOME MEASURES Patients were rated and classified for spinal stability using SINS. Intraclass correlation coefficient (ICC) and Fleisss kappa measures were occupied for reliability analysis. METHODS Patients who underwent either radiotherapy alone or surgery followed by radiotherapy were randomly selected and classified for spinal stability using the SINS by orthopedic surgeons and nonorthopedic oncology specialists. ICC and Fleisss kappa were calculated for inter- and intraobserver agreement. A comparative analysis of SINS and the actual management was also conducted. RESULTS Interobserver ICC reliability for the SINS was 0.79; κ values for location, pain, bone quality, alignment, vertebral body collapse, and posterolateral involvement were 0.81, 0.58, 0.21, 0.45, 0.42, and 0.29 respectively. Intraobserver ICC for the SINS scores was 0.96; ICC values for the same components were 0.98, 0.98, 0.87, 0.88, 0.92, and 0.86, respectively. Potentially unstable lesions (SINS score≥7) were operated on in 62.5%. CONCLUSIONS SINS seem to be a reproducible tool that could be used equally by multiple specialists to estimate metastatic vertebral stability; however, prospective clinical validation is still pending.

An independent interobserver reliability and intraobserver reproducibility evaluation of the new AOSpine Thoracolumbar Spine Injury Classification System.

Study Design. Agreement study. Objective. To perform an independent interobserver and intraobserver agreement evaluation of the new AOSpine Thoracolumbar Spine Injury Classification System. Summary of Background Data. The new AOSpine Thoracolumbar Spine Injury Classification System was recently published. It showed substantial reliability and reproducibility among the surgeons who developed it; however, an independent evaluation has not been performed. Methods. Anteroposterior and lateral radiographs, and computed tomographic scans of 70 patients with acute traumatic thoracolumbar injuries were selected and classified using the morphological grading of the new AOSpine Thoracolumbar Spine Injury Classification System by 6 evaluators (3 spine surgeons and 3 orthopedic surgery residents). After a 6-week interval, the 70 cases were presented in a random sequence to the same evaluators for repeat evaluation. The Kappa coefficient (&kgr;) was used to determine the interobserver and intraobserver agreement. Results. The interobserver reliability was substantial when considering the fracture type (A, B, or C), with a &kgr;= 0.62 (0.57–0.66). The interobserver agreement when considering the subtypes was moderate; &kgr;= 0.55 (0.52–0.57). The intraobserver reproducibility was also substantial, with 85.95% full intraobserver reproducibility considering the fracture type, with &kgr;= 0.77 (0.72–0.83), and was also substantial when considering subtypes with 75.71% full agreement and &kgr;= 0.71 (0.67–0.76). No significant differences were observed between spine surgeons and orthopedic residents in the overall interobserver reliability and intraobserver reproducibility, or in the inter- and intraobserver agreement of specific A, B, or C types of injuries. Conclusion. This classification allows adequate agreement among different observers and by the same observer on separate occasions. Future prospective studies should evaluate whether this classification improves clinical decision making. Level of Evidence: 2

An assessment of the Surgical Apgar Score in spine surgery

BACKGROUND CONTEXT The Surgical Apgar Score (SAS), a simple metric based on intraoperative heart rate, blood pressure, and blood loss, was developed in general and vascular surgery to predict 30-day major postoperative complications and mortality. No validation of SAS has been performed in spine surgery. PURPOSE To perform a prospective assessment of SAS in spine surgery. STUDY DESIGN Prospective study. PATIENT SAMPLE Two hundred sixty-eight consecutive patients undergoing major and intermediate spinal surgeries in an 18-month period. OUTCOME MEASURES Occurrence of major complications or death within 30 days of surgery. METHODS Intraoperative parameters were registered, and SAS was calculated immediately after surgery. Outcome data were collected during a 30-day follow-up. The relationship between SAS and the outcomes was analyzed calculating relative risks (RRs) and likelihood ratios (LRs) for different scoring groups. A univariate logistic regression analysis was also performed. The discriminatory accuracy of SAS was evaluated calculating a C-statistic. RESULTS Eighteen patients had ≥1 complications (6.72%). Patients with SAS 9-10 exhibited a 1.64% complication rate (RR=1; LR=0.23), which monotonically augmented as the score decreased: (SAS 7-8=2.75%; RR=1.68; LR=0.39), (SAS 5-6=13.33%; RR=8.13; LR=2.14), (SAS≤4=17.39%; RR=10.61; LR=2.92). The regression analysis odds ratio was 0.66 (95% confidence interval, 0.54-0.82), p<.01. The C-statistic was 0.77 (95% confidence interval, 0.66-0.88). CONCLUSIONS Surgical Apgar Score allows risk stratification and has a good discriminatory power in patients undergoing spine surgery.

An independent inter- and intra-observer agreement evaluation of the AOSpine subaxial cervical spine injury classification system.

Study Design. An agreement study. Objective. The aim of this study was to perform an independent interobserver and intraobserver agreement assessment of the AOSpine subaxial cervical spine injury classification system. Summary of Background Data. The AOSpine subaxial cervical spine injury classification system was recently described. It showed substantial inter- and intraobserver agreement in the study describing it; however, an independent evaluation has not been performed. Methods. Anteroposterior and lateral radiographs, computed tomography scans, and magnetic resonance imaging of 65 patients with acute traumatic subaxial cervical spine injuries were selected and classified using the morphologic grading of the subaxial cervical spine injury classification system by 6 evaluators (3 spine surgeons and 3 orthopedic surgery residents). After a 6-week interval, the 65 cases were presented to the same evaluators in a random sequence for repeat evaluation. The kappa coefficient (&kgr;) was used to determine the inter- and intraobserver agreement. Results. The interobserver agreement was substantial when considering the fracture main types (A, B, C, or F), with &kgr; = 0.61 (0.57–0.64), but moderate when considering the subtypes: &kgr; = 0.57 (0.54–0.60). The intraobserver agreement was substantial considering the fracture types, with &kgr; = 0.68 (0.62–0.74) and considering subtypes, &kgr; = 0.62 (0.57–0.66). No significant differences were observed between spine surgeons and orthopedic residents in the overall inter- and intraobserver agreement, or in the inter- and intraobserver agreement of specific A, B, C, or F type of injuries. Conclusion. This classification allows adequate agreement among different observers and by the same observer on separate occasions. Future prospective studies should determine whether this classification allows surgeons to decide the best treatment for patients with subaxial cervical spine injuries. Level of Evidence: 3

Inter and intra-observer agreement evaluation of the AO and the Tronzo classification systems of fractures of the trochanteric area

INTRODUCTION We performed an agreement study of the AO and the Tronzo classifications of fractures of the trochanteric area to determine if they allow communication among practitioners with different levels of expertise. MATERIAL AND METHODS Complete radiographs of 70 patients with trochanteric fractures were classified by nine evaluators (three hip sub-specialists, three orthopaedic surgery residents and three medical interns) using the AO and the Tronzo classifications. After a six-week interval, all cases were presented in a random sequence for repeat evaluation. The Kappa coefficient (k) was used to determine inter- and intra-observer agreement. RESULTS Inter-observer: considering the main AO fracture types, the agreement was moderate for sub-specialists (k = 0.60 [0.50-0.70]), residents (k = 0.58 [0.48-0.69]) and medical interns (k = 0.56 [0.45-0.69]). Using AO sub-types, all groups achieved fair agreement (sub-specialists: k = 0.31 [0.25-0.38]; residents: k = 0.32 [0.26-0.38]; medical interns: k = 0.30 [0.24-0.36]). For the Tronzo classification, sub-specialists (k = 0.56 [0.48-0.65]) and residents (k = 0.47 [0.39-0.55]) obtained moderate agreement; medical interns reached fair agreement (k = 0.33 [0.25-0.41]). Intra-observer: considering the main AO fracture types, sub-specialists (k = 0.79 [0.69-0.89]), residents (k = 0.71 [0.60-0.81]) and medical interns (k = 0.70 [0.59-0.82]) obtained substantial agreement. Considering AO sub-types, sub-specialists (k = 0.50 [0.45-0.56]) and medical interns (k = 0.54 [0.48-0.69]) achieved moderate agreement; residents (k = 0.39 [0.33-0.45]) achieved fair agreement. Using the Tronzo classification, all groups obtained substantial agreement (sub-specialists: k = 0.66 [0.58-0.74]; residents: k = 0.63 [0.55-0.71]; medical interns: k = 0.68 [0.60-0.76]). CONCLUSION The AO classification allows an adequate communication when considering the main fracture types; the agreement within sub-types is not satisfactory. The Tronzo classification does not allow reliable communication between medical professionals.

Thoracic scoliosis prevalence in patients 50 years or older and its relationship with age, sex, and thoracic kyphosis.

Study Design. Cross-sectional study. Objective. To determine the prevalence of thoracic scoliosis in patients aged 50 years or older and to investigate the association of adult thoracic scoliosis with age, sex, and thoracic sagittal curve. Summary of Background Data. The prevalence of adult thoracic scoliosis has not been clearly determined. In addition, limited data are available on the correlation of adult thoracic scoliosis to age, sex, and thoracic kyphosis. Methods. We studied 760 patients aged 50 years or older (380 males and 380 females) who were evaluated using standing chest plain radiographs. The thoracic curvatures in the coronal and sagittal planes were measured using the Cobb method. Scoliosis was defined by the presence of a coronal curvature 10° or more. We performed a correlation analysis of the coronal curve with age and sagittal curve; in addition, a linear regression analysis was carried out to evaluate age, sex, and sagittal curve as independent predictors of the coronal Cobb angle of the thoracic spine. Results. The prevalence of thoracic scoliosis was 24.2% (184 cases); 160 patients (21.1%) had curves 10° or more but less than 20°; 20 patients (2.6%) had curves 20° or more but less than 30°; and 4 patients (0.5%) had curves 30° or more. Females exhibited a higher prevalence of scoliosis (28.9%) than did males (19.4%), P < 0.01. The older patients exhibited increased scoliosis, but no differences were observed in thoracic kyphosis with increasing scoliosis. Age and sex were independent predictors of the coronal Cobb angle; however, the sagittal angle was not. Conclusion. We found a 24.2% prevalence of thoracic scoliosis in patients 50 years or older; most curves were less than 20°. Thoracic scoliosis was more common in females and in older patients. Level of Evidence: 3

Effect of propionibacterium acnes (PA) injection on intervertebral disc degeneration in a rat model: does it mimic modic changes?

INTRODUCTION Multiple reports of bacterial isolates in human disc tissue have suggested a role of low-grade infection on intervertebral disc degeneration and modic changes (MC) generation. Animal models have been extensively used to study IDD; however, until recently, no consideration had been given to eventual infectious processes. To reproduce the phenomena by inoculating an infecting agent would support the infectious hypothesis. Therefore, we studied the effect of Propionibacterium acnes (PA) inoculation on rat-tails and determined whether it would produce MCs on the adjacent endplates. HYPOTHESIS Disc infection with PA would accelerate IDD compared with the standard model and would also lead to MCs on the adjacent endplates. METHODS Twelve Sprague-Dawley rats were randomized to receive a needle puncture in a caudal tail disc with either saline (control) or an inoculum of 5×107 CFU of strain 1a PA. Twelve weeks later, the rats were euthanized and the tails were analyzed. The main assessment criteria were obtained from the post-mortem MRI: T2 values of punctured discs and adjacent endplates, as well as disc volumes. A histological grading score for IDD was also used, measuring the morphology and cellularity of the nucleus and annulus, as well as endplate disruption. RESULTS The median T2 value and disc volume were smaller in PA-punctured discs [T2 value: 30ms (23-44) vs. 61ms (38-132), respectively, P=0.01; 0.01mm3 (0.01-0.05) vs. 0.5mm3 (0.01-5.35), respectively; P=0.049]. There was no change in the adjacent endplates. There was no significant difference in histological grading between the test and control [13 (10-14) vs. 10.5 (6-13); P=0.05]. DISCUSSION Inoculation of caudal discs with PA generated increased degeneration; however, no MCs were observed on the adjacent endplates. A better understanding of low-grade disc infections is still needed. LEVEL OF EVIDENCE V (animal study).

Do Orthopaedic Oncologists Agree on the Diagnosis and Treatment of Cartilage Tumors of the Appendicular Skeleton

BackgroundDistinguishing a benign enchondroma from a low-grade chondrosarcoma is a common diagnostic challenge for orthopaedic oncologists. Low interrater agreement has been observed for the diagnosis of cartilaginous neoplasms among radiologists and pathologists, but, to our knowledge, no study has evaluated inter- and intraobserver agreement among orthopaedic oncologists grading these lesions using initial clinical and imaging information. Determining such agreement is important since it reflects the certainty in the diagnosis by orthopaedic oncologists. Agreement also is important as it will guide future treatment and prognosis, considering that there is no gold standard for diagnosis of these lesions.Questions/Purposes(1) to determine inter- and intraobserver agreement among a multinational panel of expert orthopaedic oncologists in diagnosing cartilaginous neoplasms based on their assessment of clinical symptoms and imaging at diagnosis. (2) To describe the most important clinical and imaging features that experts use during the initial diagnostic process. (3) To determine interobserver agreement for proposed initial treatment strategies for cartilaginous neoplasms by this panel of evaluators.MethodsThirty-nine patients with intramedullary cartilaginous neoplasms of the appendicular skeleton of various histopathologic grades were selected and classified as having benign, low-grade malignant, or intermediate- or high-grade malignant neoplasms by 10 experienced orthopaedic oncologists based on clinical and imaging information. Additionally, they chose the three most important clinical or imaging features for the diagnosis of these neoplasms, and they proposed a treatment strategy for each patient. The Kappa coefficient (κ) was used to determine inter- and intraobserver agreement.ResultsInter- and intraobserver agreements were only fair to good, κ = 0.44(95% CI, 0.41–0.48) and κ = 0.62 (95% CI, 0.52–0.72), respectively. The three factors most frequently identified as helpful in making the diagnosis by our panel were cortical involvement in 65% of evaluations (253/390), neoplasm size in 51% (198/390), and pain in 50% (194/390). The interobserver agreement for the proposed initial treatment strategy after diagnosis was poor (κ = 0.21; 95% CI, 0.18–0.24).ConclusionsThis study showed barely fair interobserver and fair to good intraobserver agreement for grading of intramedullary cartilaginous neoplasms by orthopaedic oncologists using initial clinical and imaging findings. These results reflect the insufficient guidance interpreting clinical and imaging features, and the limitations of the systems we use today when making these diagnoses. In the same way, they generate concern for the implications that this may have on different treatment strategies and the future prognosis of our patients. Future studies should build on these observations and focus on clarifying our criteria of diagnosis so that treatment recommendations are standardized regardless of the treating institution or oncologist.Level of EvidenceLevel III, diagnostic study.

Do thoraco-lumbar spinal injuries classification systems exhibit lower inter- and intra-observer agreement than other fractures classifications?: A comparison using fractures of the trochanteric area of the proximal femur as contrast model.

INTRODUCTION It has been postulated that the complex patterns of spinal injuries have prevented adequate agreement using thoraco-lumbar spinal injuries (TLSI) classifications; however, limb fracture classifications have also shown variable agreements. This study compared agreement using two TLSI classifications with agreement using two classifications of fractures of the trochanteric area of the proximal femur (FTAPF). MATERIAL AND METHODS Six evaluators classified the radiographs and computed tomography scans of 70 patients with acute TLSI using the Denis and the new AO Spine thoraco-lumbar injury classifications. Additionally, six evaluators classified the radiographs of 70 patients with FTAPF using the Tronzo and the AO schemes. Six weeks later, all cases were presented in a random sequence for repeat assessment. The Kappa coefficient (κ) was used to determine agreement. RESULTS Inter-observer agreement: For TLSI, using the AOSpine classification, the mean κ was 0.62 (0.57-0.66) considering fracture types, and 0.55 (0.52-0.57) considering sub-types; using the Denis classification, κ was 0.62 (0.59-0.65). For FTAPF, with the AO scheme, the mean κ was 0.58 (0.54-0.63) considering fracture types and 0.31 (0.28-0.33) considering sub-types; for the Tronzo classification, κ was 0.54 (0.50-0.57). Intra-observer agreement: For TLSI, using the AOSpine scheme, the mean κ was 0.77 (0.72-0.83) considering fracture types, and 0.71 (0.67-0.76) considering sub-types; for the Denis classification, κ was 0.76 (0.71-0.81). For FTAPF, with the AO scheme, the mean κ was 0.75 (0.69-0.81) considering fracture types and 0.45 (0.39-0.51) considering sub-types; for the Tronzo classification, κ was 0.64 (0.58-0.70). CONCLUSION Using the main types of AO classifications, inter- and intra-observer agreement of TLSI were comparable to agreement evaluating FTAPF; including sub-types, inter- and intra-observer agreement evaluating TLSI were significantly better than assessing FTAPF. Inter- and intra-observer agreements using the Denis classification were also significantly better than agreement using the Tronzo scheme.

Surgical dislocation of the hip without trochanteric osteotomy

Background: Surgical dislocation of the hip remains an important alternative in hip preservation surgery, especially when a dynamic access to the hip is needed and arthroscopy is not a suitable option. We describe a novel technique for operative dislocation of the hip without trochanteric osteotomy and the clinical results of our patients. Methods: Surgical dislocation of the hip without trochanteric osteotomy was done through a modified lateral approach in all of the cases. A review of demographic, clinical, and radiological data was done in all of the patients operated with this technique between 2010 and 2015. Complications, walking aids, weight-bearing status, and modified Harris Hip Score (mHHS) were also recorded. Results: Six surgical dislocations of the hip were carried out. Indications were tumor resection in five and bulletectomy in one hip. There were two women (four hips) and two men. Mean age was 19 ± 3.8 years. Median follow-up was 2.5 years (range 2–4.5 years). Median mHHS was 92 (90–96). There were no intraoperative nor postoperative complications. Conclusions: Surgical dislocation of the hip without trochanteric osteotomy through a modified lateral approach appears to be a safe, simpler, and effective alternative.