Pelvic Obliquity Correction in Distraction-Based Growth Friendly Implants

Spine to pelvis "T-Construct" using magnetic controlled growing rods in non-walkers neuromuscular early-onset scoliosis: a preliminary study

BACKGROUNDS

Magnetic controlled growing rods (MCGRs) have been proven to be effective in controlling early onset neuromuscular scoliosis but no study has evaluated the combination with a sacro-bi-iliac construct. The aim of our study is to report surgical management of early onset non-walkers neuromuscular scoliosis correction using MCGRs associated with a sacro-bi-iliac "T-construct" and its mid-term outcomes. Our hypothesis was that this set-up provided well correction of the pelvic obliquity and that this correction was maintained over time.

METHODS

A retrospective single-center study was conducted including all consecutive neuromuscular early onset scoliosis who underwent spinopelvic fixation using "T-construct" with two MCGRS. Four millimeters lengthening was performed every 4 months during outpatient clinics sessions. All children had a low-dose biplanar stereoradiography in EOS-Chair at pre/postoperative phase, each outpatient clinic appointment and last follow-up.

RESULTS

Eighteen patients were included and 17 analyzed at the last follow-up. The mean age at surgery was 9.5 (range from 5 to 12 years), the mean follow-up was 4,7 years (range from 2.5 to 6.6 years) and 8 patients had a Risser stage above four. The global complication rate was 35% (N = 6/17 patients) including three medical and three mechanical complications related to "T-construct", while the reoperation rate was 18% (N = 2 patients for wound debridement and one for iterative pelvic fixation). Cobb angle and pelvic obliquity were significantly improved by surgery (mean correction was 33.2 ° (55%) and 11 ° (77%) respectively; p < 0.001). At the last follow-up, we noted a loss of frontal Cobb angle correction (p < 0.01) whereas we did not observe any significant loss of pelvic obliquity (p > 0.9).

CONCLUSIONS

Although the global complication rate was 35% (half of which are mechanical complications), the treatment combining pelvic T-construct and MCGRs provides satisfactory correction of pelvic obliquity correction, good maintenance in the medium term and may be a procedure to consider for the surgical treatment of early onset neuromuscular scoliosis.

LEVEL OF EVIDENCE

IV; Retrospective cohort prognostic study.

Pelvic Fixation for Non-Ambulatory Patients with Neuromuscular Scoliosis Treated with Magnetically Controlled Growing Rods-A 4-Year Comparison of Two Different Fixation Methods

Background/Objectives: This study aims to analyze the efficacy and safety of the two pelvic fixation systems, S-hooks (SH) and lumbar-sacral-alar-iliac (SAI) screws, when used in association with magnetically controlled growing rods (MCGRs) in non-ambulatory children with severe neuromuscular scoliosis (NMS). Methods: Forty-one patients were retrospectively examined and subdivided corresponding to ilium hook fixation or SAI screws. The major curve correction (%) and pelvic obliquity (PO) correction (%) were assessed utilizing scoliosis plain film radiographs over time. Complications and unplanned return to the operating room (UPROR) were recorded. Patient-specific pre- and postoperative values were included in a backward stepwise regression model to assess UPROR. Results: Mean age at index intervention was 9.4 years. Preoperative main curve was 81° and PO was 22°. 21 and 20 patients were categorized into the SH and SAI subgroups, respectively. Initial curve correction was significantly better in the SAI subgroup (63 vs. 42% in the SH, p = 0.045), while PO correction was equally good. Curve and PO correction were maintained throughout the follow-up period of 55 months. UPROR rate was 38% in the SH subgroup, and 5% in the SAI subgroup (p = 0.010). Regression analysis identified postoperative curve correction as predictive value for UPROR (p = 0.006). Conclusions: SAI screw fixation has a low UPROR rate and achieves superior curve correction. S-hooks are a viable option to correct PO and NMS in children with high operative risk to reduce operative time, but revision surgery is not uncommon.

Effects of bracing on pelvic parameters in adolescent idiopathic scoliosis: A retrospective study

To evaluate the effects of Chêneau bracing on Cobb's angle (CA) and spinopelvic parameters in adolescent idiopathic scoliosis (AIS) patients. In this retrospective study, we evaluated 51 AIS patients who received Chêneau bracing treatment between January 2020 and August 2021. The prebracing and in-bracing radiographs were analyzed about the spinopelvic parameters. The CA, pelvic coronal obliquity angle, thoracolumbar kyphosis (TLK), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), sagittal vertical angle, and coronal vertical angle were measured. Paired t-test was used to compare prebracing and in-bracing spinopelvic parameters. The Pearson correlation analysis was used to identify the relationships between the variations in the spinopelvic parameters. The mean age at the initiation of bracing was 13.6 ± 1.5 years. The mean prebracing CA was 24.0° ± 6.3°. There were no statistically significant differences between prebracing and in-bracing measurements of sagittal and coronal vertical angles. However, there were statistically significant differences between the prebracing and in-bracing measurements of the CA, pelvic coronal obliquity angle, TLK, LL, PT, and SS. A significant correlation was observed between PT and thoracolumbar kyphosis variations in the sagittal plane. The pelvic coronal obliquity angle variation was correlated to the prebracing pelvic coronal obliquity angle in the coronal plane. Chêneau's bracing effects of AIS can be extended to the pelvis. Affected by the Chêneau brace, the pelvis should be retro-rotated correspondingly to TLK hyperkyphosis on the sagittal plane, whereas in the coronal plane, pelvic obliquity was improved independently. The effect of Chêneau braces on the pelvic parameters should be fully considered before bracing treatment.

Uncorrected Pelvic Obliquity Is Associated With Worse Health-related Quality of Life (HRQoL) in Children and Their Caregivers at the End of Surgical Treatment for Early Onset Scoliosis (EOS)

BACKGROUND

While largely of concern in nonambulatory patients, pelvic obliquity (PO) can be found in many patients with early onset scoliosis (EOS) and may remain following surgery. However, its association with health-related quality of life (HRQoL) in children and their caregivers at the end of treatment is not well understood. The purpose of this study was to investigate the association between residual PO and HRQoL in children and their caregivers at the end of surgical treatment in ambulatory patients with EOS.

METHODS

In this retrospective cohort study, a multicenter EOS registry was queried to identify ambulatory patients who underwent definitive posterior spinal fusion (PSF) from 2012 to 2019. Patients with fusions extending to the pelvis were excluded. PO was measured at least 1 year following PSF. HRQoL, Parental Burden, Financial Burden, and Satisfaction were assessed through the 24-Item Early Onset Scoliosis Questionnaire (EOSQ-24) also at a minimum of 1 year following PSF.

RESULTS

A total of 155 patients (12.5±2.1 y, 73.5% female) were included. Etiology distribution was 30.3% congenital, 12.9% neuromuscular, 21.3% syndromic, and 35.5% idiopathic. In congenital patients, those with residual PO >8 degrees had worse Satisfaction by 23.2 points compared with those with PO ≤8 degrees. In neuromuscular patients, those with residual PO >7 degrees had worse HRQoL by 16.1 points and Parental Burden by 22.3 points compared with their counterparts. In syndromic patients, those with residual PO >8 degrees had worse HRQoL by 14.8 points, Parental Burden by 16.4 points, and Satisfaction by 21.2 points compared with their counterparts. In idiopathic patients, those with >9 degrees of residual PO had worse HRQoL by 15.0 points and Financial Burden by 26.8 points compared with their counterparts.

CONCLUSIONS

Remaining PO at the end of surgical treatment is associated with worse HRQoL in ambulatory children and their caregivers. These results suggest that correction of PO should remain a primary goal of treatment in patients with EOS undergoing surgery.

LEVEL OF EVIDENCE

Level II-multicenter retrospective cohort study investigating prognosis.

Pelvic obliquity associated with neuromuscular scoliosis in cerebral palsy: cause and treatment

STUDY DESIGN

Literature Review.

OBJECTIVE

Review the etiology, clinical manifestations, diagnosis, and treatment of pelvic obliquity in cerebral palsy patients with neuromuscular scoliosis. Neuromuscular scoliosis (NMS) in cerebral palsy (CP) patients is rapidly progressive and often leads to an imbalance in musculoskeletal mechanics that extends to the pelvis. A horizontal misalignment of the pelvis in the frontal plane known as pelvic obliquity (PO) is a common finding in this population. When untreated, PO can exacerbate the back pain, postural strain, and walking difficulties experienced by these patients. Establishing the manifestation and treatment plan for PO in the setting of NMS can provide valuable insight for diagnosis and management.

METHODS

A comprehensive literature review was performed on the etiology, clinical manifestations, diagnosis, and treatment of pelvic obliquity in the setting of NMS in CP. The advantages and limitations of measurement and treatment options were evaluated.

RESULTS

PO is categorized into suprapelvic, infrapelvic, and intrapelvic causes, each presenting with a unique pattern of pathology. NMS in CP with hip contractures and structural deformities fall into these categories. The Maloney and O'Brien methods of pelvic measurement have demonstrated superior utility and are recommended for clinical diagnosis. The management of PO in NMS patients is focused on the cause of malalignment, with posterior fusion, contracture release, and osteotomy encompassing the mainstay of treatment.

CONCLUSION

PO is commonly found in patients with NMS in cerebral palsy. There is currently no standard method for determining the PO angle. Interventions designed to reduce scoliotic curves and release tissue contractures can level the pelvis and restore proper alignment of the spine and sacrum in the coronal plane in these patients. Further understanding of the causes of PO in NMS, as well as the establishment of a standardized measuring technique and diagnostic parameters will allow for more effective treatment options and improve outcomes in patients with CP.

LEVEL OF EVIDENCE

N/A.