Sagittal classification in adolescent idiopathic scoliosis: original description and therapeutic implications.

INTRODUCTION: Surgical treatment of AIS aims to correct the coronal and sagittal alignment of the spine. The global alignment of the spine may be normalized through reciprocal changes between the fused spine and adjacent segments. We propose a new classification system describing the specific sagittal patterns induced by AIS to define reproducible guidelines for the surgical strategy. METHODS: We analyzed 100 consecutive AIS patients aged between 12 and 18 years candidate for spinal fusion. The following parameters were measured and compared for each pattern: spino-pelvic parameters, magnitude and length of the lumbar sagittal angle, magnitude and length of the thoracic sagittal angles (T1T12 and T4T12 angles, TKmax), T10 L2 angle, C7 slope and C2C7 angle. RESULTS: Three parameters strongly differentiated the four patterns: thoracic sagittal angles (T1T12 and T4T12 angles, TKmax), T10 L2 angle and C7 slope. Less than half of the patients (44%) had a normal sagittal shape. Within, Type 2 characterized by thoracic hypokyphosis, Type 2a (thoracic hypokyphosis) were mostly Lenke type 1 or 2 curves, and type 2b (thoracic hypokyphosis with TL kyphosis) occurred specifically in double major or TL/L curves. Type 3 were two-curve sagittal shape with cervicothoracic kyphosis and TL lordosis (9%), mainly in Lenke 1 curves. DISCUSSION: This new classification summarizes all the pathological scenarios of the sagittal alignment of AIS into four patterns. A specific surgical planning can be extrapolated for each pattern. In type 1, the objective is to preserve the sagittal shape. In type 2, the objective is to restore thoracic kyphosis. In type 2b, TL junction should be straightened. In type 3, the objective is to reshape the lower arc of thoracic sagittal angle and straighten the TL junction. These slides can be retrieved under Electronic Supplementary Material.

Surgical treatment of thoraco-lumbar kyphosis (TLK) associated with low pelvic incidence.

PURPOSE: Thoraco-lumbar kyphosis (TLK) is poorly described in the literature and its surgical treatment remains equivocal for patients with low pelvic incidence. The aim of the study was to identify which surgical correction would yield the best functional results as measured by the Oswestry score. MATERIALS AND METHODS: This is a retrospective study including patients described as a type 1 of Roussouly's classification with a thoraco-lumbar kyphosis. Fifty-six patients with degenerative spinal disease were included, 42 (75%) with scoliosis and 14 (25%) without. Patients had a median age of 56 years (49-63), and there were 6 (11%) men. The primary outcome was the functional Oswestry disability index (ODI). RESULTS: At last follow-up, the median ODI was 15 (Q1-Q3: 6-23). In the degenerative spinal disease group, the median ODI was 7 (3.5-20) at last follow-up. Ten (84%) patients were classified as Roussouly's type 1 after surgery. In the degenerative scoliosis group, the ODI was 17 (8-23) in patients classified as Roussouly's type 1 and 20 (7.5-25) in patients classified as Roussouly's type 2 with no significant difference between these groups (p = 1). There were two patients classified as Roussouly's type 3a and their ODI at last follow-up were of 60 and 50. CONCLUSION: It seems that keeping the physiological morphology is the treatment of choice. For patients with degenerative scoliosis, reducing the kyphosis could work. We do not recommend to increase the lordosis and obtain a type 3 morphology with an anteverted pelvis because of the risk of PJK and poor functional results.

Evolution of adolescent idiopathic scoliosis: results of a multicenter study at 20 years' follow-up.

INTRODUCTION: To date there is no consensus on therapeutic indications in adolescent idiopathic scoliosis (AIS) with curvature between 30° and 60° at the end of growth. OBJECTIVE: The objective of this study was to assess outcome in patients with moderate AIS. MATERIAL AND METHODS: A multicenter retrospective study was conducted. Inclusion criteria were: Cobb angle, 30-60° at end of growth; and follow-up > 20 years. The data collected were angular values in adolescence and at last follow-up, and quality of life scores at follow-up. RESULTS: A total of 258 patients were enrolled: 100 operated on in adolescence, 116 never operated on, and 42 operated on in adulthood. Mean follow-up was 27.8 years. Cobb angle progression significantly differed between the 3 groups: 3.2° versus 8.8° versus 23.6°, respectively; P < 0.001. In lumbar scoliosis, the risk of progression to ≥ 20° was significantly higher for initial Cobb angle > 35° (OR=4.278, P=0.002). There were no significant differences in quality of life scores. DISCUSSION: Patients operated on in adolescence showed little radiological progression, demonstrating the efficacy of surgical treatment for curvature greater than 50°. Curvature greater than 40° was progressive and may require surgery in adulthood. Lumbar scoliosis showed greater potential progression than thoracic scoliosis in adulthood, requiring fusion as of 35° angulation. LEVEL OF EVIDENCE: IV, retrospective study.

Estimation of sagittal pelvic orientation from frontal standard radiograph using the sacral-femoral-pubic angle: feasibility study in the pediatric population.

PURPOSE: Pelvic tilt is usually measured on a full spine sagittal view. The sacral-femoral-pubic angle (SFP) has been previously described as a reproducible method to estimate pelvic tilt on a pelvis AP view. The aim of our study is to determine the reliability of the extrapolated pelvic tilt (ePT) using the SFP angle in the pediatric population. METHODS: We selected 240 full spine X-rays in our pediatric imaging database. The cohort was equally distributed according gender and age. The following parameters were measured: SFP angle on the AP view, pelvic tilt (PT), pelvic incidence (PI) and sacral slope (SS) on the sagittal view. Concordance between the measured pelvic tilt (mPT) and the calculated (ePT) value of PT was tested by a correlation test. Intra- and inter-observer reliability was tested for each parameter using ANOVA. RESULTS: Our cohort included 240 children aged from 1 to 20 years (mean age 10.7 years). Mean SFP angle was 68.98° ± 6.8, mPT was 6.67° ± 8.56, ePT was 6.04° ± 6.79. The mean PI (45.04° ± 11.09) and SS (38.63° ± 8.12) were comparable to previously published pediatric data according to age groups. Intra- and inter-observer reliability showed acceptable correlation. Concordance between mPT and ePT was higher in older children (patients >10 years). CONCLUSIONS: Estimated value of pelvic tilt using the SFP angle showed acceptable correlation to the pelvic tilt measured on sagittal view of the pelvis in children over 10 years. However, correlation rates were lower than previous publication in adult population. This simple method could accurately estimate the pelvic orientation on a single frontal view of the pelvis, which may be of particular interest in understanding the relationship between pelvic orientation and hip pathology. LEVEL OF EVIDENCE: IV.

Osteoid osteoma of the proximal femur: treatment by percutaneous bone resection and drilling (PBRD). A report of 44 cases.

INTRODUCTION: Osteoid osteoma is a benign osteogenic tumor that is mainly located in the lower limbs. According to Campanacci the proximal femur is involved in 25% of cases. We present a series of 44 cases of osteoid osteoma located in the neck of the femur or the lesser trochanter treated by the minimally invasive method, CT-guided percutaneous bone resection and drilling (PBRD). MATERIALS AND METHODS: This series included 44 patients, 20 girls and 24 boys, treated between 1987 and 2012. The average age at surgery was 12.7 years old (range 4-34). The diagnosis was based on the "association" of scintigraphy (hyperfixation) - CT scan (nidus located on the femoral neck or near the lesser trochanter). These patients underwent CT-guided PBRD under general anesthesia. Specific ancillary material was used to reach and remove the nidus and a cylinder of bone was sent to the pathologist for assessment. A lateral or anterior approach was used in all cases except one in which a posterior incision was made. Histological confirmation was obtained in 23 cases (the bone fragment was damaged in 21 cases). RESULTS: Forty-two patients were reviewed after a minimum follow-up of one year (12-56 months). Two patients were lost to follow-up. Results were evaluated clinically and on CT scan 1 year after surgery: there were 35 cures with complete and permanent pain relief. There were 5 failures and 1 case of recurrence requiring a second CT-guided PBRD procedure as well 2 complications involving femoral fracture (one associated with failure). DISCUSSION: The proximal femur is a common location of osteoid osteoma. Treatment requires careful preoperative planning to determine the surgical approach for safe removal. PBRD is a minimally invasive technique, allowing complete resection with suitable ancillary equipment. This method should be compared with thermoablation, which is a similar technique. CONCLUSION: CT-guided PBRD is a therapeutic option in case of osteoid osteoma of the proximal femur. LEVEL OF EVIDENCE: Level IV.

Direct costs associated with the management of progressive early onset scoliosis: estimations based on gold standard technique or with magnetically controlled growing rods.

BACKGROUND: The main disadvantage of the surgical management of early onset scoliosis (EOS) using conventional growing rods is the need for iterative surgical procedures during childhood. The emergence of an innovative device using distraction-based magnetically controlled growing rods (MCGR) provides the opportunity to avoid such surgeries and therefore to improve the patient's quality of life. HYPOTHESIS: Despite the high cost of MCGR and considering its potential impact in reducing hospital stays, the use of MCGR could reduce medical resource consumption in a long-term view in comparison to traditional growing rod (TGR). MATERIALS AND METHODS: A cost-simulation model was constructed to assess the incremental cost between the two strategies. The cost for each strategy was estimated based on probability of medical resource consumption determined from literature search as well as data from EOS patients treated in our centre. Some medical expenses were also estimated from expert interviews. The time horizon chosen was 4 years as from first surgical implantation. Costs were calculated in the perspective of the French sickness fund (using rates from year 2013) and were discounted by an annual rate of 4%. Sensitivity analyses were conducted to test model strength to various parameters. RESULTS: With a time horizon of 4 years, the estimated direct costs of TGR and MCGR strategies were 49,067 € and 42,752 €, respectively leading to an incremental costs of 6135 € in favour of MCGR strategy. In the first case, costs were mainly represented by hospital stays expenses (83.9%) whereas in the other the cost of MCGR contributed to 59.5% of the total amount. In the univariate sensitivity analysis, the tariffs of hospital stays, the tariffs of the MCG, and the frequency of distraction surgeries were the parameters with the most important impact on incremental cost. DISCUSSION: MCGR is a recent and promising innovation in the management of severe EOS. Besides improving the quality of life, its use in the treatment of severe EOS is likely to be offset by lower costs of hospital stays. LEVEL OF EVIDENCE (WITH STUDY DESIGN): Level IV, economic and decision analyses, retrospective study.

Cervical spine alignment in the pediatric population: a radiographic normative study of 150 asymptomatic patients.

PURPOSE: To describe the normal cervical sagittal alignment of the pediatric spine in a normal population and to identify the changes during growth period. METHODS: We randomly selected in PACS database 150 full-spine standing views. Exclusion criteria were: age >18 years, spinal deformity and any disease affecting the spine (medical charts reviewing). For cervical alignment we measured: OC-angle according to Mc Gregor, C1C7 angle, upper cervical angle, inferior cervical angle and C7 tilt. Spino pelvic parameters were analyzed: T1 tilt, thoracic kyphosis, lumbar lordosis, pelvic incidence, sacral slope and pelvic tilt. We compared two age subgroups (juvenile and adolescent). Differences between age groups and gender were tested using Student's t test. Correlations between sagittal spinal parameters were evaluated using Pearson's test. RESULTS: Cervical spine shape was correlated to cranio cervical orientation to maintain horizontal gaze (r = 0.60) and to thoracic kyphosis (r = -0.46). Cervical spine alignment was significantly different between the two age groups except for the global C1C7 cervical lordosis, which remained stable. A significant gender difference was found for all the cervical sagittal angles (p < 0.01) whereas no differences were demonstrated for the spino pelvic parameters, except the lumbar lordosis (p = 0.047). CONCLUSIONS: This study is the first to report the cervical spinal alignment in a normal pediatric Caucasian population. Even though cervical lordosis is the common shape, our results showed variability in cervical sagittal alignment. Cervical spine is a junctional area that adjusts its alignment to the head position and to the underlying spinal alignment.

Osteoid osteoma of the acetabular fossa: five cases treated with percutaneous resection.

BACKGROUND: Osteoid osteoma is a painful benign osteogenic tumour for which the treatment objective is surgical resection of the nidus. The acetabular fossa is an uncommon site of involvement where surgical access can prove challenging. MATERIALS AND METHODS: We report a case-series composed of five patients with osteoid osteoma of the acetabular fossa treated with percutaneous bone resection and drilling under computed tomography guidance. RESULTS: All five patients had an uneventful postoperative course with immediate pain relief that was sustained over time. DISCUSSION: The outcomes achieved using our percutaneous technique compare favourably with those of other percutaneous methods, most notably regarding pain relief and patient tolerance of the procedure. CONCLUSION: Percutaneous bone resection and drilling under computed tomography guidance proved effective for the treatment of osteoid osteoma involving the acetabular fossa. LEVEL OF EVIDENCE: Level IV.

Osteoid osteoma transformation into osteoblastoma: fact or fiction?

BACKGROUND: Osteoid osteoma and osteoblastoma are rare, benign, bone-forming tumours. The clinical presentation, imaging study findings, and course indicate clearly that these two tumours are distinct entities. CLINICAL REPORTS: We report two cases suggesting transformation of osteoid osteoma into osteoblastoma and therefore inviting a discussion of the links between these two tumours. An 11-year-old girl with a small metaphyseal lesion of the proximal tibia was given a diagnosis of osteoid osteoma. Over the next few weeks, worsening pain and marked tumour growth prompted a biopsy, which was consistent with an aggressive osteoblastoma. A review of the case suggested primary osteoblastoma at the earliest stage of development. In a 14-year-old boy, en-bloc excision was performed to remove a 1cm defect located within the femoral shaft cortex and typical for osteoid osteoma. An asymptomatic recurrence measuring 20mm along the long axis was removed 18 months later. Reassessment of the histological slides indicated recurrence of an incompletely excised osteoid osteoma. DISCUSSION: The histological similarities between osteoid osteoma and osteoblastoma, together with the lesion size criterion, may result in confusion. Collaboration between the clinician and pathologist is crucial and should take the tempo of evolution into account. CONCLUSION: The histopathological differences between these two tumour types deserve to be emphasized. The data reported here challenge the concept that osteoid osteoma can transform into osteoblastoma. These two tumours are distinct entities that should no longer be differentiated based on size, as was long done in the past.

Early surgical anterior release for congenital and isolated elbow contracture in flexion: a case report of a 16-month-old child.

Isolated congenital elbow contracture is a rare upper-extremity disorder and there are few data about management of this condition. Authors report their experience after aggressive management of children with isolated congenital elbow contracture in flexion. Because of total absence of range of motion (ROM) improvement despites physical therapy (ROM 90-120°) and bone deformity, an anterior surgical release of the elbow was performed through an extensive lateral approach, at sixteen months of age. After surgery, this child was treated by three casts at maximal gained extension followed by sequential Turnbuckles splints. After five years of follow-up, the result was excellent with ROM 5-135°, normal function and absence of growth disturbance. The limiting factor of this protocol was excessive traction in elbow extension on the neurovascular structures, especially the radial nerve. This treatment represents an aggressive management with multiple general anaesthesia, but was found to be a valid option.

Induced membrane technique for reconstruction after bone tumor resection in children: a preliminary study.

AIM: Segmental long-bone defect due to tumor resection remains a challenge to treat. The induced membrane technique is a new alternative for biological reconstruction. During the first stage, a cement spacer is inserted after bone resection and stabilisation. The cement spacer is removed during a second stage procedure performed after chemotherapy, and cortico-cancellous bone autograft was placed in the biological induced chamber. The aim of this study was to assess preliminary results in eight children. PATIENTS AND METHODS: This prospective study included six girls and two boys, with a mean age of 12.1 years (range 9.5 to 18) and treated for a mean 15 cm defect (range 10 to 22 cms) due to resection of osteosarcoma (n=4), Ewing sarcoma (n=3) and low grade sarcoma. All patients except one, were given pre- and postoperative chemotherapy. Surgery was performed for three patients with a distal femur tumor, two patients with a proximal tibial tumor and three patients who had proximal humerus, shaft of humerus and fibular tumors. Fixation was mainly performed with locking compression plate (n=4) and locked nail (n=2). The mean operating times for first and second step procedures were 4.8 and 4h respectively. The healing process was radiologically assessed. RESULTS: After a mean follow-up of 21.6 months (15 to 30), all patients were free of disease and seven had bony union. For the lower limb reconstructions, full weight bearing was possible after a mean of 116 days (range 90 to 150) following the second stage. Mean time to bone union was 4.8 months (1.5 to 10). The early Musculoskeletal Tumor Society (MSTS) score was 25.2/30 (range 20-30). Complications were: non-union (n=1), paradoxical graft resorption (n=1) requiring graft revision. CONCLUSION: This two stage procedure reduces the operating time during the first stage and it also reduces early complications. Rapid bone union is objectively obtained despite major bone resection and the patients receiving chemotherapy. SIGNIFICANCE: The induced membrane technique could be an excellent alternative for biological reconstruction after tumor resection in children.