Ahmet Alanay

Short-segment pedicle instrumentation of thoracolumbar burst fractures: does transpedicular intracorporeal grafting prevent early failure?

Study Design. A prospective, randomized study comparing two treatment methods for thoracolumbar burst fractures: short-segment instrumentation with transpedicular grafting and the same procedure without transpedicular grafting. Objective. To evaluate the efficacy of transpedicular grafting in preventing failure of short-segment fixation for the treatment of thoracolumbar burst fractures. Summary of Background Data. Short-segment pedicle instrumentation for thoracolumbar burst fractures is known to fail early because of the absence of anterior support. Additional transpedicular grafting has been offered as an alternative to prevent this failure. However, there is controversy about the results of transpedicular grafting. Methods. Twenty patients with thoracolumbar burst fractures were included in the study. The inclusion criterion was the presence of fractures through the T11–L3 vertebrae without neurologic compromise. The patients were randomized by a simple method into two groups. Group 1 patients were treated using short-segment instrumentation with transpedicular grafting (TPG) (n = 10), and Group 2 patients were treated by short-segment fixation alone (NTPG) (n = 10). Clinical (Likert’s questionnaire) and radiologic (sagittal index, percentage of anterior body height compression, and local kyphosis) outcomes were analyzed. Results. The two groups were similar in age, follow-up period, and severity of the deformity and fracture. The postoperative and follow-up sagittal index, percentage of anterior body height compression, and average correction loss in local kyphosis in both groups were not significantly different. The failure rate, defined as an increase of 10° or more in local kyphosis and/or screw breakage, was also not significantly different (TPG = 50%, NTPG = 40%, P = 0.99). Conclusions. Short-segment transpedicular instrumentation of thoracolumbar burst fractures is associated with a high rate of failure that cannot be decreased by additional transpedicular intracorporeal grafting.

Refinement of the SRS-22 health-related quality of life questionnaire function domain

Study Design. Prospective observational case series. Objectives. To improve the Scoliosis Research Society-22 (SRS-22) Health-Related Quality of Life (HRQL) questionnaire Function domain internal consistency for patients younger than 18 years. Summary of Background Data. During English validation as well as Spanish and Turkish transcultural adaptation studies, low internal consistency of the Function domain was discovered for patients younger than 18 years. The problem was traced to questions 15 (relating to financial considerations) and 18 (relating to going out with friends). Otherwise, the SRS-22 HRQL questionnaire has been shown to be valid and has been successfully translated into Spanish and Turkish. Methods. Based on existing data, question 18s stem and responses were revised without changing its content and added to the SRS-22 questionnaire. Question 15 remained unchanged, and the effect of inclusion or exclusion on domain score was determined. During a 3-month period, the questionnaire was completed by 111 outpatients, including four groups: idiopathic scoliosis age <18 years (n = 37), idiopathic scoliosis age ≥18 years (n = 32), other spinal disorders age <18 years (n = 17), and other spinal disorders age ≥18 years (n = 25). Results. As a result of the revision of question 18, the Function domain internal consistency, Cronbachs alpha, for patients age <18 years was increased from 0.67 to 0.78 for patients with idiopathic scoliosis and from 0.60 to 0.80 for patients with other spinal disorders. Domain internal consistency remained high, 0.77 to 0.96 for all the other domain-patient groupings. Removal of question 15 slightly improved Function domain internal consistency for idiopathic scoliosis patients <18 years old and slightly decreased it for patients <18 years old with other spinal conditions. Conclusion. With a minor revision of question 18 (related to going out) the internal consistency of the SRS-22 Function domain has been improved in idiopathic scoliosis patients <18 years of age. Deletion of question 15 (related to financial considerations) has a variable, small effect depending on patient group. Retention of question 15 is recommended unless a cultural variable, such as differences in healthcare payment schemes, substantially lowers domain psychometric properties.

The evolution of sagittal segmental alignment of the spine during childhood.

Study Design. Cross-sectional. Objectives. The purpose of this study is to describe the normative data of the sagittal plane on pediatric age population, and to document the evolution of sagittal alignment with growth. Summary of Background Data. Having normative data about the sagittal plane is an integral part in the planning of the three-dimensional reconstruction of the spine. Segmental sagittal plane analysis on adults has been studied thoroughly; however, there are inadequate data on children. Methods. A total of 151 children (72 girls, 79 boys) without musculoskeletal abnormality between the ages of 3 to 15 years were studied with the 36-inch standing lateral radiograph with the arms flexed at 30°. There were a minimum of 10 children, at least 4 of them from one sex, in each age group. Variables measured on the radiograms were as follows: segmental angulations from T1–T2 to L5–S1, angles of global kyphosis (T1–T12) and lordosis (L1–S1), segmental angulations of T2–T5, T10–T12, T10–L2, and L4–S1 levels, T1 and L1 offsets in millimeters, location of thoracic and lumbar apexes, and spinopelvic alignment measurements (angles of alpha and beta, sagittal vertebral axis, and sacropelvic translation). For statistical analysis, the children were grouped in terms of ages: Group I (3–6 years of age), Group II (7–9 years of age), Group III (10–12 years of age), and Group IV (13–15 years of age). Results. One-way analysis of variance showed significant differences between the following parameters among groups: segmental angulations of T1–T2 (P = 0.015), T10–L2 (P = 0.014), L4–S1 (P = 0.001), global kyphosis angle (P = 0.005), global lordosis angle (P = 0.000), thoracic apex (P = 0.007), T1 offset (P = 0.000), sagittal vertebral axis (P = 0.004), and beta angle (P = 0.000). As sagittal vertebral axis increases, there is found to be a higher L1 offset and lower thoracic apex, both of which result in leaning forward. With growing, total thoracic kyphosis and total lumbar lordosis particularly due to lower 2 motion segments were found to be increased, while thoracic apex moved upwards, T1 offset increased, and L1 offset decreased. Older children stood with a more negative SVA, and sacral inclination increased. Conclusion. Sagittal spinal alignment is found to be changing as a child grows. There is a statistically significant difference among different age groups, especially at cervicothoracic, thoracolumbar, and lumbosacral junc-tions. The position of the sacrum (inclination and translation), and spatial orientation, as well as the global magnitude of thoracic kyphosis, and lumbar lordosis changes with growth. These findings should be taken into consideration for the young patients who require spinal instrumentation. The question “whether sagittal alignment should be restored according to the normative data for the child’s age or to the normative data for the adulthood” remains to be answered.

Reliability and Validity of Adapted Turkish Version of Scoliosis Research Society-22 (SRS-22) Questionnaire

Study Design. Outcome study to determine the internal consistency, and validity of adapted Turkish version of Scoliosis Research Society-22 (SRS-22) Instrument. Objectives. To evaluate the validity and reliability of adapted Turkish Version of SRS-22 questionnaire. Summary of Background Data. The SRS-22 questionnaire is a widely accepted questionnaire to assess the health-related quality of life for scoliotic patients in the United States. However, its adaptation in languages other than the source language is necessary for its multinational use. Methods. Translation/retranslation of the English version of the SRS-22 was done, and all steps for cross-cultural adaptation process were performed properly by an expert committee. Later, SRS-22 questionnaires and previously validated Short Form-36 (SF-36) outcome instruments were mailed to 82 patients who had been surgically treated for idiopathic scoliosis. All patients had a minimum of 2 years follow-up. Fifty-four patients (66%) responded to the first set of questionnaires. Forty-seven of the first time respondents returned their second survey. The average age of the 47 patients (12 male, 35 female) was 19.8 years (range, 14–31 years). The two measures of reliability as internal consistency and reproducibility were determined by Cronbach α statistics and intraclass correlation coefficient, respectively. Concurrent validity was measured by comparing with an already validated questionnaire (SF-36). Measurement was made using the Pearson correlation coefficient (r). Results. The study demonstrated satisfactory internal consistency with high Cronbach α values for the four of the corresponding domains (pain, 0.72; self-image, 0.80; mental health, 0.72; and satisfaction, 0.83). However, the Cronbach α value for function/activity domain (0.48) was considerably lower than the original questionnaire. The intraclass correlation coefficient for the same domains was 0.80, 0.82, 0.78, 0.81, and 0.76, respectively, demonstrating a satisfactory test/retest reproducibility. Considering concurrent validity, two domains had excellent correlation (r = 0.75–1), while 9 had good correlation (r = 0.50 to 0.75), and 6 had moderate correlation (r =0.25–0.50). Based on these results, question 18 in the function/activity domain with lower Cronbach α value was revised while question 15 was excluded. The revised SRS-22 was given to 30 adolescent idiopathic scoliosis patients not included in the index study. The revision could improve the Cronbach α value for function/activity domain from 0.48 to 0.81. Conclusion. This study demonstrated that, if measures are to be used across cultures, the items must not only be translated well linguistically but also must be culturally adapted to maintain the content validity of the instrument at a conceptual level across different cultures. This may necessitate several validation studies to ensure and improve consistency in the content and face validity between source and target versions of a questionnaire due to difficulty in detecting subtle differences in the living habits of different cultures.

Measurement of vertebral rotation in standing versus supine position in adolescent idiopathic scoliosis

Thirty-three structural curves of 25 patients with adolescent idiopathic scoliosis were evaluated using computed tomography (CT) scans and plain radiography. The average Cobb angle on standing radiographs was 55.72° and was observed to be corrected spontaneously to 39.42° while the patients were in supine position (29.78% correction). Average apical rotation according to Perdriolle was 22.75° on standing radiographs and 16.78° on supine scanograms. The average rotation according to Aaro and Dahlborn on CT scans was 16.48°. Radiographic measurements were significantly different from axial CT slice or scanogram measurements (p = 0.000), but the two latter measurements, both obtained in the supine position, did not appear to be different (p = 0.495). Deformities on the transverse plane as well as on the coronal plane are influenced by patient positioning. If the patient lies supine, the scoliosis curve corrects spontaneously to some degree on both planes. Measurements obtained from the scanograms by the Perdriolle method in the supine position are very similar to those obtained by CT. Perdriolles is a simple, convenient, and reliable method to measure rotation on standing radiograms.

An update on bone substitutes for spinal fusion

With the current advances in spinal surgery, an understanding of the precise biological mechanism of each bone substitute is necessary for inducing successful spinal fusion. In this review, the categories of bone substitutes include allografts, ceramics, demineralized bone matrix, osteoinductive factors, autogenous platelet concentrate, mesenchymal stem cells, and gene therapy. Further, clinical studies have been evaluated by their levels of evidence in order to elucidate the precise effect of the bone substitute employed and to establish clinical guidance. This article will review both clinical studies based on evidence and basic research in current advances in order to avoid as far as possible any chances of failure in the future and to understand cellular biology in novel technologies.

Kinematic analysis of the relationship between the grade of disc degeneration and motion unit of the cervical spine.

Study Design. Kinetic MRIs of cervical spines were obtained and analyzed according to the amount of motion and the degenerative grade of the intervertebral disc. Objective. To define the relationship between the grade of disc degeneration and the motion unit of the cervical spine and elucidate changes in the role of each cervical spine unit during flexion-extension motion caused by degeneration. Summary of Background Data. Degenerative changes in the cervical disc occur with age. The correlation between the degree of cervical disc degeneration and extent of cervical spine mobility has not yet been determined. The effect of degeneration on the overall motion of the functional spinal unit also remains undefined. Methods. We studied 164 patients with symptomatic neck pain. The cervical intervertebral discs were graded by spine surgeons according to the degenerative grading system (Grades I to V). All radiologic data from kinetic MRIs were recorded on a computer for subsequent measurements. All measurements and calculations for translational motion and angular variation of each segment were automatically performed by a computer analyzer. Results. The translational motion in discs with Grade II degeneration (mild degeneration) increased to Grade III degeneration (higher degeneration). However, the translational motion and angular variation significantly decreased for the Grade V (severe degeneration). For patients with relatively low grades of degeneration, Grades I and II discs, the C4–C5 and C5–C6 segmental units contributed the majority of total angular mobility of the spine. However, for the severely degenerated segments, Grade V discs, the contributions of the C4–C5 and C5–C6 U significantly decreased. Conclusion. The changes that occur with disc degeneration progress from the normal state to an unstable phase with higher mobility and subsequently to an ankylosedstage. This study evaluated the contribution of different levels to the changes in overall motion that occur with degeneration.

Reliability and concurrent validity of the adapted chinese version of scoliosis research society-22 (SRS-22) questionnaire

Study Design. Validation study to define validity and reliability of an adapted and translated questionnaire. Objective. Assessment of the concurrent validity and reliability of a Chinese version of SRS-22 outcome instrument. Summary of Background Data. No valid health-related quality of life (HRQL) outcome instrument exists for patients with spinal deformity in Chinese. The modified SRS-22 questionnaire was proven to be an appropriate outcome instrument in English, and has already been translated and validated in several other languages. Methods. The English version of the SRS-22 questionnaire was adapted to Chinese according to the International Quality of Life Assessment Project guidelines. To assess reliability, 48 subjects with adolescent idiopathic scoliosis (mean age, 16.5 years) filled the questionnaire on 2 separate occasions (Group 1). To assess concurrent validity, 50 subjects (mean age, 21 years) filled in the same questionnaire and a previously validated Chinese version of the Short Form-36 (SF36) questionnaire (Group 2). Internal consistency, reproducibility and concurrent validity were determined with Cronbachs &agr; coefficient, interclass correlation coefficient and Pearson correlation coefficient, respectively. Results. Cronbachs &agr; coefficient for the 4 major domains (function/activity, pain, self-image/appearance and mental health) were high. Intraclass correlation was also excellent for all domains. For concurrent validity, excellent correlation was found in 1 domain, good in 12 domains, moderate in 3 domains, and poor in 1 domain of the 17 relevant domains. Discussion. Both cultural adaptation and linguistic translation are essential in any attempt to use a HRQL questionnaire across cultures. The Chinese version of the SRS-22 outcome instrument has satisfactory internal consistency and excellent reproducibility. It is ready for use in clinical studies on idiopathic scoliosis in Chinese-speaking societies.

Osteotomies/spinal column resections in adult deformity

Osteotomies may be life saving procedures for patients with rigid severe spinal deformity. Several different types of osteotomies have been defined by several authors. To correct and provide a balanced spine with reasonable amount of correction is the ultimate goal in deformity correction by osteotomies. Selection of osteotomy is decided by careful preoperative assessment of the patient and deformity and the amount of correction needed to have a balanced spine. Patient’s general medical status and surgeon’s experience levels are the other factors for determining the ideal osteotomy type. There are different osteotomy options for correcting deformities, including the Smith-Petersen osteotomy (SPO), pedicle subtraction osteotomy (PSO), bone-disc-bone osteotomy (BDBO) and vertebral column resection (VCR) providing correction of the sagittal and multiplanar deformity. SPO refers to a posterior column osteotomy in which the posterior ligaments and facet joints are removed and a mobile anterior disc is required for correction. PSO is performed by removing the posterior elements and both pedicles, decancellating vertebral body, and closure of the osteotomy by hinging on the anterior cortex. BDBO is an osteotomy that aims to resect the disc with its adjacent endplate(s) in deformities with the disc space as the apex or center of rotational axis (CORA). VCR provides the greatest amount of correction among other osteotomy types with complete resection of one or more vertebral segments with posterior elements and entire vertebral body including adjacent discs. It is also important to understand sagittal imbalance and the surgeon must consider global spino-pelvic alignment for satisfactory long-term results. Vertebral osteotomies are technically challenging but effective procedures for the correction of severe adult deformity and should be performed by experienced surgeons to prevent catastrophic complications.

The effect of transpedicular intracorporeal grafting in the treatment of thoracolumbar burst fractures on canal remodeling.

Abstract. Short-segment posterior instrumentation for the treatment of thoracolumbar burst fractures has been reported with a high rate of failure. Transpedicular intracorporeal grafting in combination with short-segment instrumentation has been offered as an alternative to prevent failure. However, concern still remains about the potential complication of further canal narrowing or failure of remodeling with this technique. The purpose of this prospective, randomized, controlled study is to evaluate the effect of transpedicular intracorporeal grafting on spinal canal restoration and remodeling in a group of patients treated with short-segment instrumentation for thoracolumbar burst fractures. Twenty-one patients with thoracolumbar burst fractures were randomised into transpedicular grafting (TPG) (n=11) and non- transpedicular grafting (NTPG) (n=10) groups, and were prospectively followed for an average of 50 months (range 25–85 months). Groups were similar in age, type of fracture, load sharing classification and kyphotic deformity. Preoperative, postoperative and follow-up computed tomographic (CT) images through the level of pedicles were obtained, corrected for differences in magnification, and digitized. Areas of the spinal canals were measured and normalized by the estimated area at that level (average of adjacent levels). Average kyphosis was 19.7°±6.2° at presentation, was corrected to 1.9°±4.9° by operation, but was found to have deteriorated to 9.1°±6.4° at final follow-up. There were no differences between groups regarding the evolution of sagittal deformity. Spinal canal narrowing was 38.5±18.2% at presentation, 22.1±19.8% postoperatively, and it further improved to –2.5±16.7% at follow-up, similar for both groups. Our results demonstrate that transpedicular intracorporeal grafting in the treatment of burst fractures does not have a detectable effect on the rate of reconstruction of the canal area or on remodeling. Spinal canal remodeling was observed to occur in all patients regardless of grafting.