Segmental Pedicle Screw Instrumentation and Fusion Only to L5 in the Surgical Treatment of Flaccid Neuromuscular Scoliosis

Distal fusion in Duchenne scoliosis: the relevance of preoperative pelvic obliquity. A case series study

PURPOSE

The aim of this study was to determine clinical and radiographic outcomes for Duchenne Muscular Dystrophy (DMD) patients who underwent posterior spinal fusion from T2/3 to L5 (without pelvic fixation), at this single centre.

METHODS

From January 2012 to January 2020, 29 consecutive DMD scoliosis patients underwent posterior spinal fusion using pedicle screws from T2/3 to L5 in a single center with a minimum of 3 years follow-up (FU). Radiologic measurements and chart review were performed.

RESULTS

Twenty nine patients aged 14 ± 1.5 years were included. No patient was lost to FU. All patients had significant correction in Cobb angle, pelvic obliquity (PO) and lumbar lordosis (LL), without loss of correction at last FU. The mean values for preoperative, immediate postoperative and last FU were CA 62o, 15o and 17o, PO: 21o, 8o and 9o; and LL 10o, -41o and -41o respectively. Correction in CA was independent of any variable analysed including implant density, rod diameter, traction, or bone density. Regarding PO, it was inversely related to age and independent of all other variables. Factors associated with postoperative complications were age and respiratory function.

CONCLUSIONS

It appears from our results that pelvic fixation might not always be required in DMD scoliosis surgery, when using pedicle screws with lowest instrumented vertebra at L5. However, larger preoperative PO values can be related with residual PO. It seems that probably related to the underlying condition, early surgery may decrease incidence of complications.

LEVEL OF EVIDENCE

IV.

Surgical and long-term functional outcomes of patients with Duchenne muscular dystrophy following spinal deformity correction

BACKGROUND

Life expectancy in patients with Duchenne muscular dystrophy (DMD) has improved due to advances in medical care. DMD patients develop progressive spinal deformity after loss of ambulatory function and onset of wheelchair dependence for mobility. There is limited published data on the effect of spinal deformity correction on long-term functional outcomes, quality of life (QoL), and satisfaction in DMD patients.

AIM

To investigate the long-term functional outcomes following spinal deformity correction in DMD patients.

METHODS

This was a retrospective cohort study from 2000-2022. Data was collected from hospital records and radiographs. At follow-up, patients completed the muscular dystrophy spine questionnaire (MDSQ). Statistical analysis was performed by linear regression analysis and ANOVA to analyse clinical and radiographic factors significantly associated with MDSQ scores.

RESULTS

Forty-three patients were included with mean age 14.4 years at surgery. Spino-pelvic fusion was performed in 41.9% of patients. Mean surgical time was 352.1 min and mean blood loss was 36% of estimated total blood volume. Mean hospital stay was 14.1 d. Postoperative complications occurred in 25.6% of patients. Mean preoperative scoliosis was 58°, pelvic obliquity 16.4°, thoracic kyphosis 55.8°, lumbar lordosis 11.1°, coronal balance 3.8 cm, and sagittal balance + 6.1 cm. Mean surgical correction of scoliosis was 79.2% and of pelvic obliquity was 80.8%. Mean follow-up was 10.9 years (range: 2-22.5). Twenty-four patients had died at follow-up. Sixteen patients completed the MDSQ at mean age 25.4 years (range 15.2-37.3). Two patients were bed-ridden and 7 were on ventilatory support. Mean MDSQ total score was 38.1. All 16 patients were satisfied with the results of spinal surgery and would choose surgery again if offered. Most patients (87.5%) reported no severe back pain at follow-up. Factors significantly associated with functional outcomes (MDSQ total score) included greater duration of post-operative follow-up, age, scoliosis postoperatively, correction of scoliosis, increased lumbar lordosis postoperatively, and greater age at loss of independent ambulation.

CONCLUSION

Spinal deformity correction in DMD patients leads to positive long-term effects on QoL and high patient satisfaction. These results support spinal deformity correction to improve long-term QoL in DMD patients.

Comparison of Distal Spine Anchors and Distal Pelvic Anchors in Children With Hypotonic Neuromuscular Scoliosis Treated With Growth-friendly Instrumentation

BACKGROUND

Lower preoperative pelvic obliquity (PO) and L5 tilt have been associated with good radiographic outcomes when the fusion ended short of the pelvis in children with neuromuscular scoliosis (NMS). Our purpose was to identify indications to exclude the pelvis in children with hypotonic NMS treated with growth-friendly instrumentation.

METHODS

This was a multicenter retrospective review. Children with spinal muscular atrophy and muscular dystrophy treated with dual traditional growing rod, magnetically controlled growing rod, or vertical expandable prosthetic titanium rib with minimum 2-year follow-up after the index surgery were identified.

RESULTS

A total of 125 patients met the inclusion criteria. Thirty-eight patients had distal spine anchors (DSAs) and 87 patients had distal pelvic anchors (DPAs) placed at the index surgery. Demographics and length of follow-up were similar between the groups but there was a greater percentage of DPA patients who were nonambulatory [79 patients (91%) vs. 18 patients (47%), P <0.0001]. Preindex radiographic measures were similar except the DSA patients had a lower PO (11 vs. 19 degrees, P =0.0001) and L5 tilt (8 vs. 12 degrees, P =0.001). Postindex and most recent radiographic data were comparable between the groups. There was no difference in the complication and unplanned returns to the operating room rates.Subanalysis of the DSA group based on ambulatory status showed similar radiographic measures except the ambulatory patients had a lower PO at all time points (preindex: 5 vs. 16 degrees, P =0.011; postindex: 6 vs. 10 degrees, P =0.045; most recent follow-up: 5 vs. 14 degrees, P =0.028). Only 1 ambulatory DSA patient had a PO ≥10 degrees at most recent follow-up compared with 6 nonambulatory DSA patients. Three (8%) DSA patients, all nonambulatory, underwent extension of their instrumentation to the pelvis.

CONCLUSIONS

Pelvic fixation should be strongly considered in nonambulatory children with hypotonic NMS treated with growth-friendly instrumentation. At intermediate-term follow-up, revision surgery to include the pelvis was rare but DSAs do not seem effective at maintaining control of PO in nonambulatory patients. DSA and DPA were equally effective at maintaining major curve control, and complication and unplanned returns to the operating room rates were similar.

LEVEL OF EVIDENCE

Level III-therapeutic.

Neuromuscular Scoliosis: A Dual-Surgeon Approach

OBJECTIVE

Neuromuscular Scoliosis (NMS) causes severe deformity and operative correction for these patients carries high complication rates. We present a retrospective study comparing a series of consecutive patients who underwent posterior fusion via a single-surgeon (SS) approach with a consecutive series of patients treated via a dual-surgeon (DS) approach.

METHODS

Patients with NMS who underwent posterior fusion via a SS approach from 2019 to 2022 were analyzed and compared to a series of patients with NMS who underwent posterior fusion via a DS approach.

RESULTS

In the SS group, the average estimated blood loss (EBL) was 675 mL, average length of stay (LOS) was 6.3 days, average operative time (OT) was 6.5 hours, average packed red blood cell transfusion was 1.5 units, with a complication rate of 30%. The DS group had an average EBL of 400 mL, a LOS of 4.8 days, an OT of 4.75 hours, an average packed red blood cell transfusion of 0.8 units, with a complication rate of 20%. The DS approach was significant for a lower EBL, OT (P < 0.001), and LOS (P < 0.03).

CONCLUSIONS

This study suggests that for patients with NMS the DS approach decreases OT, EBL, complication rates, and LOS. This further supports that this approach may benefit outcomes in NMS patients.

Pelvic fixation is not always necessary in children with cerebral palsy scoliosis treated with growth-friendly instrumentation

PURPOSE

A previous study showed that patients with neuromuscular scoliosis who underwent fusion to L5 had excellent coronal curve correction and improvement in pelvic obliquity (PO) when preoperative L5 tilt was < 15°. Our purpose was to identify indications to exclude the pelvis in children with cerebral palsy (CP) scoliosis treated with growing-friendly instrumentation.

METHODS

In a retrospective cohort study, children with CP scoliosis treated with TGR, MCGR, or VEPTR with minimum 2-year follow-up were identified from a multicenter database.

RESULTS

27 patients with distal spine anchors (DSA) and 71 patients with distal pelvic anchors (DPA) placed at the index surgery were analyzed. The DSA group had a lower pre-index PO (9° vs 16°, P = 0.0001). Most recent radiographic data were similar except the DSA patients had a smaller major curve (47° vs 58°, P = 0.038). 6 (22%) DSA patients underwent extension of the instrumentation to the pelvis (DSA-EXT), most commonly at final fusion (5 patients). DSA-EXT patients had a higher pre-index L5 tilt than patients who did not require extension (DSA-NO EXT) (19° vs 10°, P = 0.009). Sub-analysis showed a lower major curve at most recent follow-up in the DSA-EXT group compared to the DPA group (33° vs 58°, P = 0.021). The DSA-EXT group had a higher number of complications per patient compared to the DSA-NO EXT group (2.3 vs 1.1, P = 0.029).

CONCLUSION

Pre-index L5 tilt ≤ 10° and PO < 10° may be indications to exclude the pelvis in children with CP scoliosis treated with growth-friendly instrumentation. DSA may provide better long-term control of the major curve than DPA.

Is it necessary to fuse to the pelvis when correcting scoliosis in cerebral palsy?

BACKGROUND

Neuromuscular scoliosis is commonly associated with a large pelvic obliquity. Scoliosis in children with cerebral palsy is most commonly managed with posterior spinal instrumentation and fusion. While consensus is reached regarding the proximal starting point of fusion, controversy exists as to whether the distal level of spinal fusion should include the pelvis to correct the pelvic obliquity.

AIM

To assess the role of pelvic fusion in posterior spinal instrumentation and fusion, particularly it impact on pelvic obliquity correction, and to assess if the rate of complications differed as a function of pelvic fusion.

METHODS

This was a retrospective, cohort study in which we reviewed the medical records of children with cerebral palsy scoliosis treated with posterior instrumentation and fusion at a single institution. Minimum follow-up was six months. Patients were stratified into two groups: Those who were fused to the pelvis and those fused to L4/L5. The major outcomes were complications and radiographic parameters. The former were stratified into major and minor complications, and the latter consisted of preoperative and final Cobb angles, L5-S1 tilt and pelvic obliquity.

RESULTS

The study included 47 patients. The correction of the L5 tilt was 60% in patients fused to the pelvis and 67% in patients fused to L4/L5 (P = 0.22). The pelvic obliquity was corrected by 43% and 36% in each group, respectively (P = 0.12). Regarding complications, patients fused to the pelvis had more total complications as compared to the other group (63.0% vs 30%, respectively, P = 0.025). After adjusting for differences in radiographic parameters (lumbar curve, L5 tilt, and pelvic obliquity), these patients had a 79% increased chance of developing complications (Relative risk = 1.79; 95%CI: 1.011-3.41).

CONCLUSION

Including the pelvis in the distal level of fusion for cerebral palsy scoliosis places patients at an increased risk of postoperative complications. The added value that pelvic fusion offers in terms of correcting pelvic obliquity is not clear, as these patients had similar percent correction of their pelvic obliquity and L5 tilt compared to children whose fusion was stopped at L4/L5. Therefore, in a select patient population, spinal fusion can be stopped at the distal lumbar levels without adversely affecting the surgical outcomes.

ANALYSIS OF PATIENTS SUBMITTED TO SURGICAL TREATMENT FOR NEUROMUSCULAR SCOLIOSIS WITH AND WITHOUT INTRAOPERATIVE TRACTION

ABSTRACT Objectives: To compare the surgical treatment of neuromuscular scoliosis (NMS) with and without intraoperative skull-skeletal traction (ISST) in terms of the degree of curve correction, surgical time, hospitalization time, screw density, use of blood products,and complications. Methods: A comparative retrospective study, in which we analyzed the medical records and radiographs of 17 patients who underwent surgical treatment for neuromuscular scoliosis (NMS). They were divided into two groups, with 9 and 8 patients operated with and without ISST, respectively, at a referral hospital specialized in the treatment of spinal deformitiesfrom 2019 to 2021. The categorical variables were analyzed using the Chi-squared test. Results: Among the 17 patients included in the study, there was a higher prevalence of women in the group without ISST (6 and 2) and of men in group with ISST (5 and 3). The ages of the patients in the two groups ranged from 8-19 years and from 11-29 years, respectively. The screw density used in the traction group averaged 66.33%±8.49 and 82.63%±17.25 in the non-traction group, a statistically significant differencewith a P-value of 0.036. The average percent correction was 76.81%±15.61 in the traction group as compared to an average of 66.39%±12.99 in the non-traction group. In addition, there were complications in 1 patient in each of the groups. Conclusions: Surgical treatment for NMS with ISST allows surgery using fewer blood products to maintain the same hematimetric level in the postoperative period. ISST also allows the use of a lower screw density to correct more severe deformities. Level of evidence III; Comparative retrospective study.

Surgical treatment of scoliosis in Ullrich Congenital Muscular Dystrophy: a case series of 3 patients

Scoliosis in Ullrich Congenital Muscular Dystrophy (UCMD) is very common, with a reported incidence of more than 50%, and it is rapidly progressive. There are no previous studies which specifically focus on scoliosis surgery in UCMD patients. This article reports three cases of scoliosis surgery in UCMD, focusing on operative course, clinical and radiological results achieved, fusion area and complications, with a 2-year follow-up. The surgical technique adopted for vertebral arthrodesis included: high-density pedicle screw systems, asymmetric rods contouring and direct vertebral rotation. The summary results shown a significative correction of the coronal deformity, with a reduction of the mean Cobb angle from 49° to 25° post-operatively. Mean pelvic tilt remained stable, while L5-tilt showed a decrease from 10° to 6°. Mean screw density was 1.92. None of the patients required extended fixation to S2. No major complications were reported, and patients maintained their pre-operative walking ability. All the patients reported a subjective improvement in quality of life, with a better sitting comfort. In conclusion, posterior spinal fusion with high-density pedicle screw systems and direct vertebral rotation may be safe and effective in surgical correction of scoliosis in UCMD. If pelvic obliquity and L5-tilt are less than 15°, could be possible to achieve an optimal spinal and pelvic balance even without sacral or pelvic fixation.

Intraoperative traction in neuromuscular scoliosis surgery improves major curve correction when fusing to L5

BACKGROUND

Intraoperative traction has shown improved curve correction in neuromuscular scoliosis surgery. It is found to be superior to anterior release in terms of correction of both main curve and pelvic obliquity. No previous study has examined the effect of intraoperative traction in patients without pelvic fixation.

METHOD

This retrospective study included 40 non-ambulatory (GMFCS 4 or above) patients with neuromuscular scoliosis undergoing surgery with bilateral segmental pedicle screw instrumentation to L5. Twenty-two consecutive patients had intraoperative Gardner-Wells tongs and skin traction (traction group), while the remaining did not (non-traction group). Inclusion criteria were minimum 2-year follow-up, complete medical records and radiographs. Main curve (MC), pelvic obliquity (POB), T1 tilt, kyphosis, rotation, coronal and sagittal balance and preoperative bending radiographs were measured and analyzed in all patients.

RESULTS

Both groups demonstrated roughly 60% MC correction. Preoperative MC was larger in the traction group [97° (49-126) vs. 83° (40-134); P = 0.03]. The measured correction index was almost twice as large in the traction group (1.9 vs. 1.1; P = 0.001). Mean [IQR] 2-year POB was 14° [7-40] in the traction group compared to 16° [4-60] in the non-traction group (P = 0.59). Eleven patients (50%) in the traction group compared to only four (22%) in the non-traction group had a POB within 10° at 2-year follow up (RR: 2.1; 95% CI 0.8-5.2). We found no difference in kyphosis or remaining radiographic parameters. No traction-related complications were recorded.

CONCLUSION

In patients with neuromuscular scoliosis undergoing instrumented fusion to the L5, we found that intraoperative traction increased the degree of MC correction and patients were more likely to achieve POB below 10° without any effects on sagittal parameters or without any detectable significant reduction on rotation.

Current concepts in neuromuscular scoliosis

PURPOSE OF REVIEW

Spinal deformity is a common issue in pediatric patients with an underlying neurological diagnosis or syndrome. Management of neuromuscular scoliosis (NMS) is a major part of the orthopedic care of such patients, as the deformity is often progressive, and may affect gait, seating and positioning. In addition, untreated large spinal deformities may be associated with pain and/or cardiopulmonary issues over time.

RECENT FINDINGS

Recent changes in medical management of the underlying disease process appears to alter the natural history of certain neuromuscular conditions, and in the case of patients with Duchenne's muscular dystrophy significantly diminish the incidence of spinal deformity. In the most common diagnosis associated with NMS, cerebral palsy, there is evidence that despite a high complication rate, surgical management of spinal deformity is associated with measurable improvements in validated health-related quality-of-life measures. Spinal deformity is a common finding in patients with neurological diagnoses. It is important for those involved in the care of these patients to understand the natural history of NMS, as well as the potential risks and benefits to the patient and caregivers, of surgical and non-surgical interventions.