Normative spino-pelvic sagittal alignment of Lebanese asymptomatic adults: Comparisons with different ethnicities.

BACKGROUND: Normative values of sagittal alignment are used as references for the diagnosis and treatment of spinal pathologies. There are currently no reference values for the normative sagittal alignment of Lebanese subjects. The objective is to describe normative values of full body sagittal alignment parameters in asymptomatic Lebanese adults and to compare the sagittal alignment of this population to that of populations of various origins. METHODS: Included subjects were aged 18 to 28 years old. Each subject underwent a full body biplanar X-ray exam with measurement of spine, pelvis and lower limb parameters of sagittal alignment. The sagittal alignment of the Lebanese population was compared to that of other ethnicities, previously reported in the literature, using one-way ANOVA. RESULTS: Ninety-two asymptomatic Lebanese young adult volunteers (48 males, 44 females, age=21.5±2.2 years) were enrolled in this study. The mean curvature in the cervical spine was kyphotic (-4.3°) in women, while it was lordotic in men (5.4°). Men were found to be significantly more kyphotic than women (-58.3° vs. -53.0°; p<0.01) but both sexes were found to have similar lordosis (61.6°) and pelvic incidence (52.0°). Lebanese subjects had intermediate pelvic incidence compared to other ethnicities but showed significantly higher thoracic kyphosis (p<0.01) and lumbar lordosis (p<0.01) compared to all other ethnicities. CONCLUSIONS: This study established reference normative values for young adult Lebanese subjects. Most women were found to have kyphotic cervical spines. The sagittal alignment of Lebanese subjects differed significantly compared to that of other ethnicities. LEVEL OF EVIDENCE: Level IV - cross sectional study.

Selecting the lowest instrumented vertebra in adolescent idiopathic scoliosis: Comparison of the Lenke, Suk, and Dubousset criteria.

BACKGROUND: Selection of the lowest instrumented vertebra (LIV) in patients undergoing selective fusion for Lenke type 1 or 2 adolescent idiopathic scoliosis (AIS) varies widely across centres around the world. HYPOTHESIS: Lenke, Suk, and Dubousset criteria show moderate agreement for LIV selection. METHODS: Sixty-eight patients with Lenke type 1 or 2 AIS managed by selective posterior fusion and followed-up for at least 2 years were included in a retrospective observational study. Agreement among Lenke, Suk, and Dubousset criteria for LIV selection was assessed. For surgery, the LIV was selected based on Dubousset criteria. Retrospectively, in each patient, the LIV selected by the Lenke and Suk criteria sets was identified on the preoperative images. The patients were then divided into two groups based on whether the Dubousset LIV was identical versus more distal than the LIV identified retrospectively by the Lenke or Suk criteria. The primary evaluation criterion was coronal balance. RESULTS: The LIVs selected by the Lenke, Suk, and Dubousset criteria were identical in 57% of cases. The LIV selected by the Dubousset criteria were identical to that selected by the Lenke or Suk criteria in 70% of patients. No significant between-group differences were found for any of the evaluation criteria assessed preoperatively, postoperatively, or at last follow-up. DISCUSSION: Agreement among the Lenke, Suk, and Dubousset criteria was moderate, confirming the working hypothesis. No coronal malalignment developed in the patients whose actual LIV was distal to the LIV selected by the Lenke or Suk criteria, supporting the validity of Dubousset criteria for LIV selection. When selecting the LIV, all three criteria sets should be assessed. The LIV is the vertebra selected by all three if they agree or by the Dubousset criteria if they do not. LEVEL OF EVIDENCE: IV, retrospective cohort study.

Five-year outcomes of the First Distal Uninstrumented Vertebra after posterior fusion for Adolescent Idiopathic Scoliosis Lenke 1 or 2.

BACKGROUND: Tilt of the First Distal Uninstrumented Vertebra (FDUV) reflects changes in the main curve and compensatory lumbar curve after posterior fusion to treat thoracic Adolescent Idiopathic Scoliosis (AIS). HYPOTHESIS: FDUV tilt 5 years or more post-fusion depends chiefly on reduction of the main curve and on other factors such as selection of the last instrumented vertebra. MATERIAL AND METHOD: A multicenter retrospective cohort of 182 patients with Lenke 1 or 2 AIS treated with posterior instrumentation and followed up for a mean of 8 years and a minimum of 5 years was studied. The patients were divided into two groups based on whether tilt of the upper endplate of the FDUV was ≤5° or >5°at last follow-up. Variables associated with tilt were identified by multiple logistic regression. RESULTS: Six variables were significantly associated with FDUVtilt: percentage of correction at last follow-up, correction loss, lumbar modifier B, number of instrumented vertebrae, inclusion within the instrumentation of the distal neutral vertebra, and inclusion within the instrumentation of the lowest vertebra intersected by the central sacral vertical line. DISCUSSION AND CONCLUSION: The main variables associated with FDUVtilt ≤5° were a final correction percentage ≥60% and absence of correction loss between the postoperative period and last follow-up. Given the stable reduction provided by contemporary instrumentations, we recommend selective thoracic fusion of Lenke 1 or 2 AIS with lumbar modifiers A, B, and C. The lowest instrumented vertebra should be either the neutral vertebra or the vertebra intersected by the central sacral vertical line if it is distal to the neutral vertebra. LEVEL OF EVIDENCE IV: Retrospective multicenter study.

Congenital scoliosis: a frontal plane evaluation of 251 operated patients 14 years old or older at follow-up.

INTRODUCTION: Congenital scoliosis, carrying an incidence between 0.5 and 1 per 1000 births, raise the problem of their evolutive potential. HYPOTHESIS: Some predictive factors for the evolution of scoliotic curvature due to congenital vertebral malformation (CVM) can be found. MATERIAL AND METHODS: This was a retrospective multicenter study of 251 patients, at least 14 years old when evaluated at end of follow-up, with CVM and spinal deformity predominating in the frontal plane. RESULTS: 38.8% of patients showed associated neurologic, visceral or orthopedic abnormalities. CVM was single in 60.6%, double in 20.3%, triple in 6.4% and multiple in 12.7% of cases. 34.1% of CVMs were thoracic. Congenital scoliosis curvature was single in 88.8% of patients, double in 10% and triple in 1.2%. Mean curvature angle was 31.7° at diagnosis (range, 0-105°) and 41.3° preoperatively (range, 10-105°). Sixty-one patients showed associated kyphosis. Mean change in postoperative curvature angle over follow-up was 1.6° (range, -20° to 38°) in the 73 patients managed by arthrodesis, -0.4° (-24° to 30°) in the 64 managed by epiphysiodesis, and 0.4° (-18° to 35°) in the 49 managed by hemivertebral (HV) resection. Results were found to correlate significantly with age at surgery for patients managed by epiphysiodesis, but not for those managed by HV resection or arthrodesis. DISCUSSION: More than 30% of congenital scolioses involve associated intraspinal abnormality. All CVM patients should therefore undergo medullary and spinal MRI to assess the CVM in all three planes, and the medullary canal and its content. The evolution of scoliotic curvature induced by CVM is hard to predict. Several factors are to be taken into account: CVM type, number and location, and patient age. Curvature progression may be slow or very fast. It accelerates during the peak of puberty, stabilizing with bone maturity. Surgery is mandatory in evolutive scoliosis. Four procedures may be recommended, according to type of CVM and especially to patient age: arthrodesis, convex epiphysiodesis, HV resection or rib distraction. Surgery seeks to correct the spinal deformity induced by the CVM and prevent compensatory curvature and neurologic complications, while conserving sagittal and frontal spinal balance and sparing as many levels as possible. In case of HV involvement, the procedure of choice is CVM resection, which provides 87.5% good results in this indication; the procedure is relatively safe, conservative of spinal levels, and without age limit. LEVEL OF EVIDENCE: Level IV. Retrospective study.

Four sibs with dislocated elbows, bowed tibiae, scoliosis, deafness, cataract, microcephaly, and mental retardation: a new MCA/MR syndrome.

We report four sibs with an MCA/MR syndrome whose parents were first cousins. The sibs had mental retardation, microcephaly, hearing problems, cataract, and multiple osseous malformations, such as dislocated elbows, bowed tibiae, and scoliosis. Review of published reports and the use of the London Dysmorphology Database suggest that this family presents a new syndrome.