Reliability of a New Digital Tool for Photographic Analysis in Quantifying Body Asymmetry in Scoliosis.

Background: Advancements in non-ionizing methods for quantifying spinal deformities are crucial for assessing and monitoring scoliosis. In this study, we analyzed the observer variability of a newly developed digital tool for quantifying body asymmetry from clinical photographs. Methods: Prospective observational multicenter study. Initially, a digital tool was developed using image analysis software, calculating quantitative measures of body asymmetry. This tool was integrated into an online platform that exports data to a database. The tool calculated 10 parameters, including angles (shoulder height, axilla height, waist height, right and left waistline angles, and their difference) and surfaces of the left and right hemitrunks (shoulders, waists, pelvises, and total). Subsequently, an online training course on the tool was conducted for twelve observers not involved in its development (six research coordinators and six spine surgeons). Finally, 15 standardized back photographs of adolescent idiopathic scoliosis patients were selected from a multicenter image bank, representing various clinical scenarios (different age, gender, curve type, BMI, and pre- and postoperative images). The 12 observers measured the photographs at two different times with a three-week interval. For the second round, the images were randomly mixed. Inter- and intra-observer variabilities of the measurements were analyzed using intraclass correlation coefficients (ICCs), and reliability was measured by the standard error of measurement (SEM). Group comparisons were made using Student's t-test. Results: The mean inter-observer ICC for the ten measurements was 0.981, the mean intra-observer ICC was 0.937, and SEM was 0.3-1.3°. The parameter with the strongest inter- and intra-observer validity was the difference in waistline angles 0.994 and 0.974, respectively, while the highest variability was found with the waist height angle 0.963 and 0.845, respectively. No test-retest differences (p > 0.05) were observed between researchers (0.948 ± 0.04) and surgeons (0.925 ± 0.05). Conclusion: We developed a new digital tool integrated into an online platform demonstrating excellent reliability and inter- and intra-observer variabilities for quantifying body asymmetry in scoliosis patients from a simple clinical photograph. The method could be used for assessing and monitoring scoliosis and body asymmetry without radiation.

Relationship between pelvic incidence-adjusted relative spinopelvic parameters, global sagittal alignment and lower extremity compensations.

PURPOSE: In response to sagittal malalignment, compensatory spinal and lower extremity mechanisms are recruited. Thoracolumbar realignment surgery has been shown to yield reciprocal changes in these compensations. Thus, whole-body radiographic assessment has come to the fore. This study aimed to evaluate the relationship between spinopelvic parameters and lower extremity compensation angles and to examine their coupled change with deformity correction. METHODS: This was a multicenter retrospective analysis of patients who had ≥ 4 levels posterior fusion, whole-body radiographs, and ≥ 2 years follow-up. Relative Pelvic Version (RPV), Relative Lumbar Lordosis (RLL), Relative Spinopelvic Alignment (RSA), Femoral Obliquity Angle (FOA), Knee Flexion Angle (KFA) and Global Sagittal Axis (GSA) were measured preoperatively and 6 week postoperatively. Kruskal-Wallis tests were performed to assess the relation of relative spinopelvic parameters to global sagittal alignment and lower extremity compensation angles. Spearman's correlations were performed to assess correlations of pre-to-postoperative changes. RESULTS: 193 patients (156F, 37 M) were included. The mean age was 57.2 ± 16.6 years. The mean follow-up duration was 50.6 (24-90) months. On average, 10.3 ± 3.8 levels were fused. Among the cohort, 124 (64.2%) had a sacral or sacroiliac fixation, and 43 (22.3%) had 3-column osteotomies. Preoperative FOA, KFA and GSA significantly differed between RPV, RLL and RSA categories. Significant weak-to-strong correlations were observed between spinopelvic parameters, global sagittal alignment and lower extremity compensation angles (rho range: - 0.351 to 0.767). CONCLUSIONS: PI-adjusted relative spinopelvic parameters significantly correlated with measurements of the lower extremity compensation. Postoperative changes in RPV, RLL and RSA reflected changes in FOA, KFA and GSA. These measurements may serve as a valuable proxy for surgical planning when whole-body imaging is not available.

Long-term opioid medication profile of European adult spinal deformity patients: minimum five years follow-up study.

BACKGROUND CONTEXT: There remains significant variability in the use of postoperative opioids. On one end, it is proven that appropriate pain control is a critical aspect of patient management; on the other end, past few decades have been associated with major increases in opioid-related overdoses and addiction treatment. We hypothesized that several pre- and postoperative risk factors affecting long-term opioid use could be identified. PURPOSE: Evaluation of factors associated with minimum 5-year postoperative opioid use following adult spinal deformity surgery. STUDY DESIGN/SETTING: Prospectively followed study group database. PATIENT SAMPLE: Adult spinal deformity patients who underwent elective spine surgery between 2009 and 2016 were included. OUTCOME MEASURES: Opioid usage or otherwise at minimum 5 years follow-up. Use of nonopioid analgesics, weak and strong opioids METHODS: Retrospective analysis of patients undergoing elective spinal deformity surgery. A total of 37 factors comprising patient characteristics, radiographic measurements, operative details, preoperative and early postoperative opioid use, and mechanical complications and revisions were analyzed. Details on identified factors were provided. RESULTS: A total of 265 patients (215F, 50M) from five sites were included. The mean follow-up duration was 68.4±11.7 (60-102) months. On average, 10.6±3.5 levels were fused. Preoperatively, 64 (24.2%) patients were using opioids. The rate of opioid users increased to 33.6% at 6 weeks and decreased to 21.5% at 6 months. During follow-up, there were patients who discontinued opioids, while others have started and/or restarted using opioids. As a result, 59 (22.3%) patients were still on opioids at the latest follow-up. Multivariate analyses showed that factors independently affecting opioid use at an average of 68 months postoperatively, in order of significance, were opioid use at sixth weeks, preoperative opioid use and opioid use at sixth months with the odds ratios of 2.88, 2.51, and 2.38 respectively. At these time points, factors such as age, number of comorbidities, tobacco use, the time of the last prior spine surgery and postoperative sagittal plane alignment affected opioid usage rates. CONCLUSIONS: Opioid usage at 6 weeks was found to be more predictive of long-term opioid use compared to preoperative use. Patients should be well informed to have realistic expectations regarding opioid use when considering adult spinal deformity surgery.

If you look this way, you will see it: cranial shift in adolescent idiopathic scoliosis.

INTRODUCTION: Anatomical variations in the spine can be seen in each transitional border, either toward the skull as 'cranial shifts' or away as caudal shifts. Cranial shifting (CS) occurs when there is presence of occipitalization, C7 cervical costae or prominent transverse processes, thoracolumbar transitional vertebrae (TLTV) at T12 level, L5 sacralization, and sacrococcygeal fusion. We termed the coexistence of sacralization of L5 and absence or remarkable reduction of T12 rib size in AIS as Abul cranial shift (ACS). In this descriptive clinical study, primary aim was to investigate the incidence of ACS in AIS. METHODS: Retrospective analysis of 187 surgically treated AIS cases was performed. Demographic data were recorded. The incidence of the specific set of anatomic variations including lumbosacral transitional vertebrae, TLTV, transverse process changes in C7 vertebrae, and posterior lumbosacral neural arch cleft formations (NACf) were evaluated in the radiological images. RESULTS: 36 (19%) of 187 cases had ACS. ACS was detected in only 1 of 19 male cases (5%), while in 35 of 168 female cases (21%). Forty-one cases had sacralization of L5 (22%). There were only eleven pair of ribs in 14 (7%) of 187 cases and 10 (28%) of 36 ACS cases. Forty cases had NACf (21%). ACS and NACf coexistence were observed in 8 (22%) of 36 ACS cases. CONCLUSION: Accurate spinal column assessment is critical in adolescent idiopathic scoliosis (AIS). ACS may be observed in up to one in five AIS cases and its presence should not be neglected to avoid wrong level surgery.

Osteotomies for the Treatment of Adult Spinal Deformities: A Critical Analysis Review.

¼: Spinal osteotomies are powerful deformity correction techniques that may be associated with serious complications. ¼: The anatomical spinal osteotomy classification system proposes 6 grades of resection corresponding to different anatomic bone, disc, facet, and ligament interventions. ¼: Surgeons should be aware of the nuances of 3-column osteotomies with regard to spinal level selection, construct composition, and posterior column reconstruction and closure techniques. ¼: There is a global tendency toward avoiding 3-column osteotomies as much as possible because of the growing evidence regarding the effectiveness of posterior column osteotomies and halo-gravity traction.

Prevalence of benign bone lesions of the lower extremity in the pediatric spinal disorders: a whole-body imaging study.

There is a paucity of knowledge about benign bone lesions. The advances in imaging methods can screen bone lesions incidentally, and missing information can be provided. The aim of the study is to collect information about the prevalence and natural history of benign bone lesions with the use of whole-body biplanar slot-scanning imaging (EOS). EOS images acquired between 2015 and 2020 were retrospectively analyzed. Anatomical locations of lesions, number of lesions with polyostotic involvement and radiographic features of each were recorded. Fibrous lesions were further categorized according to the transition stages. The natural course was noted as remained in the same stage, progressed and disappeared during follow-up. A total of 1944 EOS images of 1378 (936 women and 442 men) patients were analyzed. The mean age was 12.3 (5-18) years. Bone lesions of the lower extremities were found in 278 scans (14.3%) of 196 (139 women and 57 men) patients (14.2%). Monostotic lesions were observed in 172 patients, and 24 had polyostotic lesions. The prevalence of lesions was 10.5%, 1.8%, 1.7%, 1.7% and 1.4‰ for fibrous cortical defect (FCD), nonossifying fibroma (NOF), osteochondroma, bone island and simple bone cyst, respectively. Among 145 FCDs, 55.2% of the lesions were stage A, 27.6% were stage B, 9.6% were stage C and 7.5% were stage D. EOS images acquired predominantly for spinal pathologies revealed a prevalence of 14% of benign bone tumors in the lower extremities. With the developments in imaging methods, the probability of encountering incidental lesion increases, and information about bone pathologies can be gathered.

Does vertebral body tethering cause disc and facet joint degeneration? A preliminary MRI study with minimum two years follow-up.

BACKGROUND CONTEXT: Vertebral body tethering (VBT), a flexible compression-based growth modulation technique, was claimed to prevent disc degeneration due to its less rigid nature compared to other growth-friendly techniques. Yet, the consequences of VBT surgery on discs and facet joints have not been precisely acknowledged. PURPOSE: The purpose of this study was to determine the changes in the intermediate and adjacent levels at least 2 years after surgery. STUDY DESIGN/SETTING: Prospectively-followed consecutive patient cohort PATIENT SAMPLE: Adolescent idiopathic scoliosis patients who underwent thoracoscopic VBT between 2014 and 2017 were included. OUTCOME MEASURES: Degeneration of the intervertebral discs using the Pfirrmann classification; Degeneration of facet joints using a scale of 0 to 3. METHODS: Demographic, perioperative, clinical, radiographic data were collected. Skeletal maturity and height gain were assessed in every follow-up. Overcorrection, tether breakage, mechanical and pulmonary complications as well as readmission and reoperations were recorded. MRIs taken before surgery and at a minimum of 2 years follow-up were evaluated for degeneration at the intermediate and adjacent segment intervertebral discs and facet joints by a blinded senior radiologist and compared. RESULTS: Twenty-five patients with a mean of 38.6±10.6 months (24-62) of follow-up were included. The mean age at surgery was 12.2 (10-14), and the median Sanders stage was 3 (1-7). A mean of 7.7±1.1 (6-11) levels were tethered. The mean preoperative main thoracic curve magnitude of 46°±7.7° was corrected to 23.3°±5.9° postoperatively, which was subsequently modulated to 12° ±11.5° during the follow-up. At the time of the MRI (mean 29±9.5 (24-62) months), the median Sanders stages was 7 (5-8). A total of 217 levels of discs and bilateral facet joints were evaluated in the preoperative and follow-up MRI images. Analyses of disc and facet scores revealed no significant differences between patients. Deterioration of previously degenerated discs was noted in one patient (from grade 2 to 3), while previously healthy lower adjacent facet joints were degenerated (grade 2) in another patient. CONCLUSIONS: Intermediate discs and facet joints were preserved after growth modulation with VBT surgery at a mean of 29 months of follow-up. Studies in larger cohorts with longer follow-up are warranted to have more in-depth analyses of the effects of relative stabilization and altered biomechanical loads.

Posterior Instrumentation and Fusion in Multiple-segment Adolescent Congenital Scoliosis: When Are Posterior Column and Concave Rib Osteotomies Needed?

BACKGROUND: No clear guidelines exist for appropriate surgical treatment of congenital scoliosis. The spectrum varies from isolated posterior instrumentation and fusion (PIF-only) to vertebral column resections. Multiple posterior column osteotomies (PCOs) with and without concave rib osteotomies have previously been suggested as an alternative to invasive 3-column osteotomies. The aim of the study is to analyze outcomes of spinal surgery in congenital scoliosis patients for a new treatment algorithm based on a traction radiograph under general anesthesia (TruGA). METHODS: Surgical intervention was determined according to flexibility with TruGA: patients with >40% correction underwent PIF-only; patients with <40% of correction underwent PCO. Patients, who had <30% of correction in TruGA and/or more than 5 vertebral levels with failure of segmentation, underwent additional concave rib osteotomies. The radiologic and clinical results were compared. RESULTS: Forty-three patients met inclusion criteria (14M). The mean age was 13.8 (10 to 17) years, average follow-up 67 (24 to 107) months. Fourteen patients were in the PIF-only group, 29 in the PCO group. PCO patients were significantly older (14.5 vs. 12.3, P=0.001). Mean operative time and blood loss of PCO group were significantly greater than those of PIF-only group. Nine patients required concave rib osteotomies. While the curve magnitude of patients in the PIF-only and PCO groups did not differ significantly (54.6 vs. 63 degrees, P=0.067), curve rigidity was significantly higher in the patients of PCO group (51.2% vs. 32%, P=0.001). Despite this, postoperative correction rates for 2 groups were similar (51.1% vs. 47.8%, P=0.545). CONCLUSIONS: The number of anomalous segments and the curve flexibility on TruGA play important roles in the decision-making process in congenital scoliosis and <40% flexibility of the major curve could be an important indicator of the need for PCO. Curves with more than 5 anomalous vertebral segments might be more likely to need additional concave rib osteotomies for adequate correction. LEVEL OF EVIDENCE: Level III.

How frequent should the radiographic examination be to monitor magnetically controlled growing rods? A retrospective look two to seven years postoperatively.

PURPOSE: Magnetically controlled growing rods (MCGR) allow more frequent outpatient lengthenings to better mimic the physiological growth. The assessment of distractions with radiographs raised concerns regarding ionizing radiation exposure in growing children. The aim was to assess the necessity of radiographs after every lengthening of MCGR. METHODS: A retrospective analysis of 30 consecutive patients (19F, 11 M) treated in a single institution between 2011 and 2017. Planned radiographs were taken based on a protocol, updated over the years to involve less frequent acquisitions. Unplanned radiographs were obtained after a patient complaint or a significant clinical examination finding. Outcome measures were preoperative and postoperative radiographic measurements, and complications such as proximal and distal junctional kyphosis and failure, rod or actuator breakage, collapse of previously achieved height or failure to lengthen and worsening of deformity. RESULTS: Mean age at surgery was 7.5 (4-11) years. Mean follow-up was 45 (24-84) months. Mean number of lengthenings and radiographs per patient were 14.4 (8-23), and 13.2 (5-46), respectively. Nine patients (30%) experienced a total of 13 mechanical complications. Almost all complications were detected in unplanned radiographs. The probability of detecting a mechanical complication was significantly lower (p < 0.00001) in planned radiographs. CONCLUSIONS: Radiographs taken after routine lengthenings of MCGR are not likely to reveal any significant finding, since only 0.9% of planned radiographs displayed a mechanical complication. Exposing growing children to radiation with an intention of checking the MCGR device after every lengthening could not be justified. Obtaining post-lengthening radiographs with a decreased frequency and after a significant complaint or clinical finding may be considered.

Intraoperative neuromonitoring practice patterns in spinal deformity surgery: a global survey of the Scoliosis Research Society.

PURPOSE: Although multimodal IONM has reached a widespread use, several unresolved issues have remained in clinical practice. The aim was to determine differences in approaches to form a basis for taking actions to improve patient safety globally. METHODS: A survey comprising 19 questions in four sections (demographics, setup, routine practices and reaction to alerts) was distributed to the membership of the SRS. RESULTS: Of the estimated 1300 members, 205 (~ 15%) completed the survey. Respondent demographics reflected SRS member distribution. Most of the respondents had > 10 years of experience. TcMEP and SSEP were available to > 95%. Less than 5% reported that a MD/PhD with neurophysiology background routinely examines patients preoperatively, while 19% would consult if requested. After an uneventful case, 36% reported that they would decrease sedation and check motor function if the patient was to be transferred to ICU intubated. Reactions to dropped signals that recovered or did not fully recover varied between attempting the same correction to aborting the surgery with no rods and returning another day, with or without implant removal. After a decrease of signals, 85.7% use steroids of varied doses. Of the respondents, 53.7% reported using the consensus-created checklist by Vitale et al. Approximately, 14% reported never using the wake-up test while others use it for various conditions. CONCLUSION: The responses of 205 experienced SRS members from different regions of the world showed that surgeons had different approaches in their routine IONM practices and in the handling of alerts. This survey indicates the need for additional studies to identify best practices.

Thoracoscopic Vertebral Body Tethering for Adolescent Idiopathic Scoliosis: Follow-up Curve Behavior According to Sanders Skeletal Maturity Staging.

STUDY DESIGN: Retrospective analysis of prospectively collected data. OBJECTIVE: To report the follow-up curve behaviors in different Sanders staging groups. SUMMARY OF BACKGROUND DATA: Vertebral body tethering (VBT) is a growth modulation technique that allows gradual spontaneous follow-up curve correction as the patient grows. There is a lack of scientific evidence regarding appropriate patient selection and timing of implantation. METHODS: Patients were grouped into five as: Sanders 1, 2, 3, 4-5, and 6-7. Data were collected preoperatively, at the day before discharge, and at each follow-up. Outcome measures were pulmonary and mechanical complications, readmission, and reoperation rates. Demographic, perioperative, clinical, radiographic, and complication data were compared using Fisher-Freeman-Halton exact tests for categorical variables and Kruskal-Wallis tests for the continuous variables. RESULTS: Thirty-one (29 F, 2 M) consecutive patients with a minimum of 12 months of follow-up were included. The mean age at surgery was 12.1 (10-14). The mean follow-up was 27.1 (12-62) months. The mean preoperative main thoracic curve magnitude was 47°â€Š±â€Š7.6°. For all curves, preoperative and first erect curve magnitudes, bending flexibility, and operative correction percentages were similar between groups (for all comparisons, P > 0.05). The median height gained during follow-up was different between groups (P < 0.001), which was reflected into median curve correction during follow-up. Total curve correction percentage was different between groups (P = 0.009). Four (12.9%) patients had pulmonary and six (19.4%) had mechanical complications. One (3.2%) patient required readmission and two (6.5%) required reoperation. Occurrence of pulmonary complications was similar in Sanders groups (P = 0.804), while mechanical complications and overcorrection was significantly higher in Sanders 2 patients (P = 0.002 and P = 0.018). CONCLUSION: Follow-up curve behavior after VBT is different in patients having different Sanders stages. Sanders 2 patients experienced more overcorrection, thus timing and/or correction should be adjusted, since Sanders 3, 4, and 5 patients displayed a lesser risk of mechanical complications. LEVEL OF EVIDENCE: 3.

Titanium mesh cage as an alternative reconstruction method for epiphyseal-sparing tumour resections in children.

In this study, we introduced an alternative reconstruction option for epiphysis-sparing tumour resection in children. Eight patients with a malignant tumour in the diaphysis or metaphysis-diaphysis junction of a long bone underwent epiphysis-sparing intercalary resection. Reconstruction was performed using a titanium mesh cage filled with impacted cancellous bone allograft and autograft. A plate and screws were used to supplement the fixation. At the last follow-up, union was achieved in seven patients. Limb-length discrepancy occurred in three patients. Functional scores revealed a good functional outcome. This technique may be an alternative method for epiphyseal-sparing tumour resections in children.

Tri-layered composite plug for the repair of osteochondral defects: in vivo study in sheep.

Cartilage defects are a source of pain, immobility, and reduced quality of life for patients who have acquired these defects through injury, wear, or disease. The avascular nature of cartilage tissue adds to the complexity of cartilage tissue repair or regeneration efforts. The known limitations of using autografts, allografts, or xenografts further add to this complexity. Autologous chondrocyte implantation or matrix-assisted chondrocyte implantation techniques attempt to introduce cultured cartilage cells to defect areas in the patient, but clinical success with these are impeded by the avascularity of cartilage tissue. Biodegradable, synthetic scaffolds capable of supporting local cells and overcoming the issue of poor vascularization would bypass the issues of current cartilage treatment options. In this study, we propose a biodegradable, tri-layered (poly(glycolic acid) mesh/poly(l-lactic acid)-colorant tidemark layer/collagen Type I and ceramic microparticle-coated poly(l-lactic acid)-poly(ϵ-caprolactone) monolith) osteochondral plug indicated for the repair of cartilage defects. The porous plug allows the continual transport of bone marrow constituents from the subchondral layer to the cartilage defect site for a more effective repair of the area. Assessment of the in vivo performance of the implant was conducted in an ovine model (n = 13). In addition to a control group (no implant), one group received the implant alone (Group A), while another group was supplemented with hyaluronic acid (0.8 mL at 10 mg/mL solution; Group B). Analyses performed on specimens from the in vivo study revealed that the implant achieves cartilage formation within 6 months. No adverse tissue reactions or other complications were reported. Our findings indicate that the porous biocompatible implant seems to be a promising treatment option for the cartilage repair.

Spinal Realignment for Adult Deformity: Three-column Osteotomies Alter Total Hip Acetabular Component Positioning.

INTRODUCTION: A goal of adult spinal deformity surgery is correction of sagittal imbalance by increasing lumbar lordosis (LL), allowing a previously retroverted pelvis to normalize as evidenced by decreases in pelvic tilt (PT). Realignment of pelvic orientation may alter the position of preexisting total hip arthroplasties (THAs). METHODS: Twenty-seven patients with unilateral THA who underwent thoracolumbar fusions for adult spinal deformity from the pelvis to L1 or above were retrospectively reviewed (levels fused, 10.3 [range, 6 to 17]; age, 70 ± 9 years). Comparisons of preoperative and postoperative spinal deformity parameters, acetabular tilt (AT), and acetabular cup abduction angle (CAA) were performed, with subgroup analysis for those who had undergone three-column osteotomy and those who had not. RESULTS: Preoperative deformity was severe, with findings of a sagittal vertical axis >9 cm, PT >25°, and pelvic incidence-LL >20°. Postoperatively, AT decreased significantly (-7° ± 10°; P < 0.001), signifying relative acetabular retroversion. Comparing patients with three-column osteotomy versus those without, AT changes were greater in those with three-column osteotomy (11° ± 7° and -2 ± 10°, respectively; P = 0.024). AT was significantly correlated with changes of PT (r = 0.704; P < 0.001) and LL (r = -0.481; P = 0.011). AT decreased (ie, retroverted) 1° for every 3.23° of LL or 1.13° of PT correction. The coronal plane CAA did not change substantially. DISCUSSION: Spinal deformity correction, with techniques such as three-column osteotomy, result in significant THA acetabular component repositioning in the sagittal plane. Resultant decreased AT (ie, retroversion) theoretically may affect tribology, wear, and joint stability and warrants further investigation.

Modular cementless prosthetic reconstruction after resection of lower extremity malignant tumor.

INTRODUCTION: The aim of the study is to report the preliminary clinical and functional outcomes of a modular cementless tumor resection prosthesis system (Megasystem-C®, Waldemar Link GmbH&Co. KG, Hamburg, Germany) in patients undergoing limb salvage surgery with wide resection in a lower extremity primary or metastatic malignant bone tumor. MATERIAL AND METHODS: Fifty-two consecutive patients (33 male and 19 female; mean age 37.1 years (range, 16 to 79) with primary or metastatic lower extremity malignant bone tumor who underwent wide resection and reconstruction with cementless Megasystem-C® system were included in the study. Patients were analyzed for age at diagnosis, gender, type and localization of the tumor, time of follow-up, patient and prosthesis survival, complications, oncological and functional outcomes. RESULTS: Mean follow-up time was 43.2 months (range, 8 to 66). Cumulative patient survival rate was 92.3 percent and cumulative prosthetic survival rate was 65.4 percent. 18 complications were recorded and 9 of them required revision (17.3 percent). Mean overall Musculoskeletal Tumor Society score score was 72.7 percent (range, 52 to 86). Subgroup analyzes demonstrated no difference in complication rates, overall patient or prosthetic survivals. Functional scores according to age, diagnosis and location of the reconstruction also were not significantly different. CONCLUSION: The preliminary short-term follow-up results revealed that, the new generation modular cementless endoprosthetic system offers promising clinical and functional outcomes with reasonable complication rates. LEVEL OF EVIDENCE: Level IV, Therapeutic study.

The dosimetric impact of implants on the spinal cord dose during stereotactic body radiotherapy.

BACKGROUND: The effects of spinal implants on dose distribution have been studied for conformal treatment plans. However, the dosimetric impact of spinal implants in stereotactic body radiotherapy (SBRT) treatments has not been studied in spatial orientation. In this study we evaluated the effect of spinal implants placed in sawbone vertebra models implanted as in vivo instrumentations. METHODS: Four different spinal implant reconstruction techniques were performed using the standard sawbone lumbar vertebrae model; 1. L2-L4 posterior instrumentation without anterior column reconstruction (PI); 2. L2-L4 anterior instrumentation, L3 corpectomy, and anterior column reconstruction with a titanium cage (AIAC); 3. L2-L4 posterior instrumentation, L3 corpectomy, and anterior column reconstruction with a titanium cage (PIAC); 4. L2-L4 anterior instrumentation, L3 corpectomy, and anterior column reconstruction with chest tubes filled with bone cement (AIABc). The target was defined as the spinous process and lamina of the lumbar (L) 3 vertebra. A thermoluminescent dosimeter (TLD, LiF:Mg,Ti) was located on the measurement point anterior to the spinal cord. The prescription dose was 8 Gy and the treatment was administered in a single fraction using a CyberKnife® (Accuray Inc., Sunnyvale, CA, USA). We performed two different treatment plans. In Plan A beam interaction with the rod was not limited. In plan B the rod was considered a structure of avoidance, and interaction between the rod and beam was prevented. TLD measurements were compared with the point dose calculated by the treatment planning system (TPS). RESULTS AND DISCUSSION: In plan A, the difference between TLD measurement and the dose calculated by the TPS was 1.7 %, 2.8 %, and 2.7 % for the sawbone with no implant, PI, and PIAC models, respectively. For the AIAC model the TLD dose was 13.8 % higher than the TPS dose; the difference was 18.6 % for the AIABc model. In plan B for the AIAC and AIABc models, TLD measurement was 2.5 % and 0.9 % higher than the dose calculated by the TPS, respectively. CONCLUSIONS: Spinal implants may be present in the treatment field in patients scheduled to undergo SBRT. For the types of implants studied herein anterior rod instrumentation resulted in an increase in the spinal cord dose, whereas use of a titanium cage had a minimal effect on dose distribution. While planning SBRT in patients with spinal reconstructions, avoidance of the rod and preventing interaction between the rod and beam might be the optimal solution for preventing unexpectedly high spinal cord doses.

The Evolution of Sagittal Spinal Alignment in Sitting Position During Childhood.

STUDY DESIGN: This is a cross-sectional descriptive study. OBJECTIVE: The purposes of this study are to describe normative data of the sagittal plane in the sitting position within the pediatric population and document the evolution of sagittal alignment during the growth. SUMMARY OF BACKGROUND DATA: Surgical procedures addressing the deformity aim to make the maximal correction on the coronal and transverse planes and to restore the physiological curves on the sagittal plane. Prerequisite for sagittal plane reconstruction is to know the physiological values. METHODS: Children between 3 and 17 years of age, followed by pediatrics unit for nonskeleton disease with lateral radiographs of the entire spine and pelvis on sitting positions, were included to the study. Children with history of surgery or disease that may affect spine development were excluded. Children were evaluated in 4 age groups (3-6, 7-9, 10-12, and 13-17 yr) in terms of spinal sagittal alignment on sitting position. RESULTS: Of the screened, 124 children (49 girls, 75 boys) were included. Descriptive statistics of all possible segmental angles were summarized. Thoracic kyphosis and lumbar lordosis values were lower on sitting position than on standing position. Thoracic segmental angulations steadily increased from T1-T2 to midthoracic segments and then decreased in caudal direction. Moreover, lumbar segmental angulations steadily increased in cephalocaudal direction. Sacral slope, L4-S1 angulation, and T1-T12 and T1-S1 distance tend to increase as the age increases. CONCLUSION: Sagittal spinal alignment in the sitting position is different than that in the standing position and it changes as the child grows. There is a statistically significant difference between different age groups, especially at the cervicothoracic, thoracolumbar, and lumbosacral junctions. These findings should be taken into consideration for young nonambulatory patients who require spinal instrumentation and/or fusion. LEVEL OF EVIDENCE: 2.

Lipoma arborescens of the knee.

PURPOSE: Lipoma arborescens (LA) is a benign lesion described as replacement of mature fat cells with sub-synovial tissue, which causes the formation of villous projections. Underlying inflammatory conditions might predispose LA. This study demonstrates the treatment, post-operative survey and MRI demonstrations of this rare entity. METHODS: Five patients (6 knees) diagnosed and treated with arthroscopic (5/6) and open (1/6) synovectomy were reviewed retrospectively. An additional mini-transquadricipital incision is used for excision of the extensive suprapatellar lesions. The patients had post-operative follow-ups at first and sixth months and then yearly. Radiographs and MRI of the affected knees were taken at the final follow-up. RESULTS: The median follow-up was 59 (4-105) months. Major symptom was painless swelling of the joint. The presenting age was under 18 years in four patients. Recurrent lesions were detected in MRI scan of three patients with JRA, ARF and Tbc. Two out of three were located adjacent to the posterior capsule. The median of the Kujala questionnaire scores was 88 (74-95), and the median of the Knee Society Clinical Rating System scores was 95 (80-100) at the final follow-up. CONCLUSIONS: Lipoma arborescens should be considered in the differential diagnosis of paediatric patients who have painless swelling of the knee joint. The lesion is totally curable. However, underlying persistent disease might aggravate the inflammatory process and might cause recurrent lesions. Although resecting the lesion adjacent to the posterior capsule of the knee joint is technically demanding, arthroscopic treatment is an effective procedure and transquadricipital approach may help resection of the extensive lesions in suprapatellar pouch. LEVEL OF EVIDENCE: Case series, Level IV.