Muharrem Yazici

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.

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.

Lengthening of Dual Growing Rods and the Law of Diminishing Returns

Study Design. A retrospective multicenter study. Objective. To evaluate the effect of repeated surgical lengthenings and time on spinal growth and Cobb angle in children with early onset scoliosis and dual growing rods. Summary of Background Data. Previous studies have established the effectiveness of dual growing rods for controlling spinal deformity and promoting spinal “growth.” Although anecdotal experience suggests that the effectiveness of repeated lengthenings decreases over time, this has not been previously studied. Methods. Medical records from five different centers were reviewed to identify children treated with dual growing rods for early onset scoliosis who had a minimum of 2-year follow-up and at least three lengthening procedures. Initial radiographs, postimplantation radiographs, and radiographs from before and after each lengthening were measured for T1-S1 distance and Cobb angle. Linear regression and analysis of variance were used for statistical analysis. Results. Thirty-eight patients from five centers met the inclusion criteria. The average age of our patients was 5.7 years (range 1.7–8.9 years); mean follow-up was 3.3 years (range 2–7 years). The average interval between lengthenings was 6.8 months. Cobb angle decreased from a mean value of 74° preoperatively to 36° after the primary implantation and did not change significantly with repeated lengthenings (P = 0.96). After initial implantation, the average annual T1–S1 gain was 1.76 ± 0.71 cm/year. The T1-S1 gain after a given lengthening, however, decreased significantly with repeated lengthenings (P = 0.007). When the effect of time was considered, there was also a significant decrease in T1–S1 gain over time (P = 0.014). Conclusion. There seems to be a “law of diminishing returns” with repeated lengthenings of dual growing rods. Repeated lengthenings still result in a net T1-S1 increase; however, this gain tends to decrease with each subsequent lengthening and over time. This phenomenon may be due to autofusion of the spine from prolonged immobilization by a rigid device.

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.

Next generation of growth-sparing techniques: preliminary clinical results of a magnetically controlled growing rod in 14 patients with early-onset scoliosis.

Study Design. Prospective nonrandomized study. Objective. To report the preliminary results of magnetically controlled growing rod (MCGR) technique in children with progressive early-onset scoliosis. Summary of Background Data. The growing rod (GR) technique is a viable alternative for treatment of early-onset scoliosis. High complication rate is attributed to frequent surgical lengthening. The safety and efficacy of MCGR were recently reported in a porcine model. Methods. Multicenter study of clinical and radiographical data of patients who underwent MCGR surgery and at least 3 distractions. Distractions were performed in clinic without anesthesia/analgesics. T1–T12 and T1–S1 heights and the distraction distance inside the actuator were measured after lengthening. Results. Fourteen patients (7 girls, 7 boys) with a mean age of 8 years, 10 months (3 yr, 6 mo to 12 yr, 7 mo) had 14 index surgical procedures. Of the 14, 5 had single-rod (SR) surgery and 9 had dual-rod (DR) surgery, with overall 68 distractions. Diagnoses were idiopathic (N = 5), neuromuscular (N = 4), congenital (N = 2), syndromic (N = 2), and neurofibromatosis (N = 1). Mean follow-up was 10 months (5.8–18.2). The Cobb angle changed from 60° to 34° after initial surgery and 31° at latest follow-up. During distraction period, T1–T12 height increased by 7.6 mm for SR (1.09 mm/mo) and 12.12 mm for DR (1.97 mm/mo). T1–S1 height gain was 9.1 mm for SR (1.27 mm/mo) and 20.3 mm for DR (3.09 mm/mo). Complications included superficial infection in 1 SR, prominent implant in 1 DR, and minimal loss of initial distraction in 3 SR after index. Partial distraction loss observed after 14 of the 68 distractions (1 DR and 13 SR) but regained in subsequent distractions. There was no neurological deficit or implant failure. Conclusion. Preliminary results indicated MCGR was safe and provided adequate distraction similar to standard GR. DR achieved better initial curve correction and greater spinal height during distraction compared with SR. No major complications were observed during the follow-up.

Growing rod fractures: risk factors and opportunities for prevention.

Study Design. Review of a prospectively collected growing rod database. Objective. To define risk factors for and characterize the nature of growing rod fractures. Summary of Background Data. Rod fracture is a common complication of growing rod treatment. The project sought to analyze risk factors for rod breakage and develop preventive strategies. Methods. Records of 327 patients in a prospectively collected growing rod database were studied. Risk factors studied were studied as patient-related and rod-related. Multivariate analysis was performed. Results. Eighty-six rod fractures occurred in 49 patients (49 of 327, 15%). Sixteen patients had repeat fractures with eight patients having more than two fractures (maximum six). The most common fracture locations were above or below the tandem connectors (34 of 86) and near the thoracolumbar junction (35 of 86). Other locations were adjacent to anchors (12 of 86) and cross-links (2 of 86). Syndromic diagnoses had the highest rate of fracture; significantly greater than neuromuscular diagnoses (14% vs. 2%, P = 0.01). Patients who were ambulatory had a higher fracture rate (21% vs. 8.7%, P = 0.01). Single rods had a higher fracture rate than dual rods (36% vs. 11%, P < 0.001). Repeat fracture was also more common in patients with single rods (13% vs. 2%, P = 0.0002). In dual-rod constructs, the incidence of both rods breaking at the same time was 26% (7 of 27). Stainless steel rods had a higher fracture rate than titanium rods (29% vs. 18%, P = 0.02). The nonfracture group had larger diameter rods than the fracture group (P = 0.01). The fracture group had shorter tandem connectors than the nonfracture group (P < 0.001). Neither the size of preoperative scoliosis (P = 0.2) nor kyphosis (P = 0.4) was a risk factor for fracture. Length of instrumentation (P = 0.9), anchor type (P = 0.6), and pelvic fixation (P = 0.38) had no significant effect on fracture rates. Eight wound complications were reported, including three cases of skin breakdown at the rod fracture site. Conclusion. Risk factors for rod fractures include prior fracture, single rods, stainless steel rods, small diameter rods, proximity to tandem connectors, short tandem connectors, and preoperative ambulation. Repeat fractures are common, especially with single rods. Rod replacement, with larger diameter rods if appropriate, may be a preferred strategy over connecting the broken rods as fractures signal fatigue of the rod.

Safety and efficacy of growing rod technique for pediatric congenital spinal deformities.

Background Growing rod surgery is a modern alternative treatment for young children with early onset scoliosis. This is the first study focused on its use in progressive congenital spinal deformities. Methods A retrospective study of 19 patients from the international multicenter Growing Spine Study Group with progressive congenital spinal deformities undergoing growing rod surgery who had a minimum of 2 years follow-up. We analyzed demographic and radiographic data including age at initial surgery, number of abnormal vertebrae per patient, number of lengthenings postoperatively, Cobb angle of the major curve preoperative, postoperative initial and at last follow-up, T1-S1 length, space available for the lung (SAL), length of follow up, and complications. Results The mean age at surgery was 6.9 years (range: 3.2 to 10.7 y). The mean number of affected vertebrae per patient was 5.2 (range: 2 to 9 vertebrae). The mean number of lengthening was 4.2 (range: 1 to 10 lengthening) per patient. The major Cobb angle improved from 66 degrees (range: 40 to 95 degrees) preoperatively to 45 degrees (range: 13 to 79 degrees) initial postoperative and 47 degrees (range: 18 to 78 degrees) at the last follow-up. The mean T1-S1 length increased from 268.3 mm (range: 192 to 322 mm) postoperatively to a mean of 315.4 mm (range: 261 to 357 mm) at last follow-up. The mean T1-S1 length increase was 11.7 mm/y. The SAL ratio increased from 0.81 preoperatively to 0.94 at latest follow-up. The mean postoperative follow-up was 4 years (range: 2 to 6.6 y). Five patients (38%) had undergone final fusion and 14 are still under treatment. Complications have occurred in 8 patients (42%). There were 14 (14%) complications in 100 procedures: 11 implant related, 2 pulmonary, and 1 postoperative infection. There were no neurological complications. Conclusions Growing rods are a safe and effective treatment technique in selected patients with congenital spinal deformities. The deformity, spinal growth, and the SAL improved. The incidence of complication was relatively low. Level of Evidence Level IV, case series.

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.

Fusionless instrumentation systems for congenital scoliosis: expandable spinal rods and vertical expandable prosthetic titanium rib in the management of congenital spine deformities in the growing child.

Study Design. Review of relevant literature including personal opinions. Objective. To review the current researches investigating the efficacy of growing rod and thoracic expansion techniques in the treatment of congenital spine deformity of young children, and to highlight the contrasting advantages and limitations in the fusionless treatment of progressive congenital scoliosis. Summary of Background Data. Congenital scoliosis has the potential for severe spinal deformity and thoracic insufficiency syndrome (TIS). Conventional fusion treatments in children tend to shorten the spine further exacerbating trunk shortening and TIS. In the surgical treatment of congenital spinal deformities in young children, while reconstructing the spinal deformity, one should simultaneously pursue preserving the growth potential of the vertebrae, improving the volume, symmetry, and functions of the thorax, and protecting this improvement during the growth. Today, employed in the treatment of spinal deformities of young children, there are 2 deformity reconstruction methods serving these targets: Growing rod technique and vertical expandable prosthetic titanium rib (VEPTR) with or without expansion thoracostomy. Methods. Peer-reviewed research articles and major international meeting presentations were reviewed. Methods were compared in terms of advantages and limitations. Results. The growing rod technique is a safe and reliable method in the treatment of congenital spine deformity of young children who present some flexibility in the anomalous segment, or when the congenital anomaly involves a vertebral segment too long for resection, or with compensating curve with structural pattern concomitant to the congenital deformity. Expansion thoracostomy and VEPTR are the appropriate choice for severe congenital spine deformity when a large amount of growth remains. Although ventilator dependence is significantly decreasing, thoracic volume and space available for the lung are increased after expansion thoracostomy and VEPTR. Conclusion. Growing rod technique should be used in patients where the primary problem is at the vertebral column. If the patient has rib fusions and/or TIS has developed, in other words, if the primary problem involves the thoracic cage, expansion thoracostomy and VEPTR should be an appropriate option.