Correlation between surgical site infection and classification of early onset scoliosis (C-EOS) in patients managed by rib-based distraction instrumentation

A Comparative Analysis of Revision Surgery Before or After 2 Years After Graduation From Growth-friendly Surgery for Early Onset Scoliosis

INTRODUCTION

After discontinuation of growth-friendly (GF) surgery for early onset scoliosis, patients are termed graduates: they undergo a spinal fusion, are observed after final lengthening with GF implant maintenance, or are observed after GF implant removal. The purpose of this study was to compare the rates of and reasons for revision surgery in two cohorts of GF graduates: before or after 2 years of follow-up from graduation.

METHODS

A pediatric spine registry was queried for patients who underwent GF spine surgery with a minimum of 2 years of follow-ups after graduation by clinical and/or radiographic evidence. Scoliosis etiology, graduation strategy, number of, and reasons for revision surgery were queried.

RESULTS

There were 834 patients with a minimum of 2-year follow-up after graduation who were analyzed. There were 241 (29%) congenital, 271 (33%) neuromuscular, 168 (20%) syndromic, and 154 (18%) idiopathic. 803 (96%) had traditional growing rod/vertical expandable titanium rib as their GF construct and 31 (4%) had magnetically controlled growing rod. Five hundred ninety-six patients (71%) underwent spinal fusion at graduation, 208 (25%) had GF implants retained, and 30 (4%) had GF implants removed.In the entire cohort, there were 108/834 (13%) patients who underwent revision surgery. Of the revisions, 71/108 (66%) occurred as acute revisions (ARs) between 0 and 2 years from graduation (mean 0.6 y), and the most common AR indication was infection (26/71, 37%). The remaining 37/108 (34%) patients underwent delayed revision (DR) surgery >2 years (mean 3.8 y) from graduation, and the most common DR indication was implant issues (17/37, 46%).Graduation strategy affected revision rates. Of the 596 patients with spinal fusion as a graduation strategy, 98/596 (16%) underwent revision, compared with only 8/208 (4%) patients who had their GF implants retained, and 2/30 (7%) that had their GF implants removed (P ≤ 0.001).A significantly higher percentage of the ARs had a spinal fusion as the graduation strategy (68/71, 96%) compared with 30/37 DRs, (81%, P = 0.015). In addition, the 71 patients who underwent AR undergo more revision surgeries (mean: 2, range: 1 to 7) than 37 patients who underwent DR (mean: 1, range: 1 to 2) (P = 0.001).

CONCLUSION

In this largest reported series of GF graduates to date, the overall risk of revision was 13%. Patients who undergo a revision at any time, as well as ARs in particular, are more likely to have a spinal fusion as their graduation strategy. Patients who underwent AR, on average, undergo more revision surgeries than patients who underwent DR.

LEVEL OF EVIDENCE

Level III, comparative.

Intraoperative Antibiotic Use in Patients With Early-onset Scoliosis: Current Practices and Trends

BACKGROUND

Best Practice Guidelines (BPGs) regarding antibiotic prophylaxis in early-onset scoliosis (EOS) patients were published in September 2019. Recommendations included using intravenous cefazolin and topical vancomycin for all index procedures, plus gram-negative coverage for neuromuscular patients. Guideline adherence is unknown. This study aimed to characterize antibiotic prophylaxis at the time of index growth-friendly procedures and assess changes in practice patterns over time.

MATERIALS AND METHODS

This retrospective review of data collected through a multicenter study group included EOS patients undergoing index growth-friendly procedures between January 2018 and March 2021, excluding revisions, lengthenings, and tetherings. Demographics, clinical measurements, intraoperative antibiotics, and 90-day complications were recorded. Descriptive and univariate statistics were utilized. Antibiotic prophylaxis from April 2018 through September 2019 and October 2019 through March 2021 were compared with evaluate change after BPG publication.

RESULTS

A total of 562 patients undergoing growth-friendly procedures were included. The most common scoliosis types included neuromuscular (167, 29.7%), syndromic (134, 23.8%), and congenital (97, 17.3%). Most index procedures involved magnetically controlled growing rods (417, 74%) followed by vertical expandable prosthetic titanium rib or traditional growing rods (105, 19%). Most patients received cefazolin alone at index procedure (310, 55.2%) or cefazolin with an aminoglycoside (113, 20.1%). Topical antibiotics were used in 327 patients (58.2%), with most receiving vancomycin powder. There was increased use of cefazolin with an aminoglycoside after BPG publication (16% vs. 25%) ( P =0.01). Surgical site infections occurred in 12 patients (2.1%) within 90 days of index procedure, 10 pre-BPGs (3%), and 2 post-BPGs (0.9%), with no significant difference in surgical site infection rate by type of antibiotic administered ( P >0.05).

CONCLUSIONS

Historical variability exists regarding antibiotic prophylaxis during index growth-friendly procedures for EOS. There continues to be variability following BPG publication; however, this study found a significant increase in antibiotic prophylaxis against gram-negative bacteria after BPG publication. Overall, greater emphasis is needed to decrease variability in practice, improve compliance with consensus guidelines, and evaluate BPG efficacy.

LEVEL OF EVIDENCE

Level III-retrospective.

The evolving stall rate of magnetically controlled growing rods beyond 2 years follow-up

PURPOSE

Magnetically controlled growing rods (MCGR) have become the dominant distraction-based implant for the treatment of early onset scoliosis (EOS). Recent studies, however, have demonstrated rising rates of implant failure beyond short-term follow-up. We sought to evaluate a single-center experience with MCGR for the treatment of EOS to define the rate of MCGR failure to lengthen, termed implant stall, over time.

METHODS

A single-center, retrospective review was conducted identifying children with EOS undergoing primary MCGR implantation. The primary endpoint was the occurrence of implant stalling, defined as a failure of the MCGR to lengthen on three consecutive attempted lengthening sessions with minimum of 2 years follow-up. Clinical and radiographic variables were collected and compared between lengthening and stalled MCGRs. A Kaplan-Meier survival analysis was conducted to assess implant stalling over time.

RESULTS

A total of 48 children met inclusion criteria (mean age 6.3 ± 1.8 years, 64.6% female). After a mean 56.9 months (range of 27 to 90 months) follow-up, 25 (48%) of children experienced implant stalling at a mean of 26.0 ± 14.1 months post-implantation. Kaplan-Meier survival analysis demonstrated that only 50% of MCGR continue to successfully lengthen at 2 years post-implantation, decreasing to < 20% at 4 years post-implantation.

CONCLUSION

Only 50% of MCGR continue to successfully lengthen 2 years post-implantation, dropping dramatically to < 20% at 4 years, adding to the available knowledge regarding the long-term viability and cost-effectiveness of MCGR in the management of EOS. Further research is needed to validate these findings.

Can magnetically controlled growing rods be successfully salvaged after deep surgical site infection?

PURPOSE

The purpose is to compare the rate of recurrent deep wound infection in patients who retained MCGRs versus those who underwent implant removal and exchange following index deep wound infection.

METHODS

Using a multicenter registry, we identified patients with EOS who underwent surgical correction with MCGR. We defined deep SSI as any infection that required subsequent I&D and antibiotic therapy. Recurrent infection was defined as any additional deep SSI following treatment of index deep infection. We considered MCGR to be salvaged if implant exchange or removal was not performed for at least 1 year following date of infection. Bivariate statistical analyses were performed.

RESULTS

992 EOS patients were identified, of whom 33 (3.3%) developed deep SSI. The mean time between initial surgery and first deep SSI was 13.1 months (Interquartile range [IQR]: 1 to 25 months. Infection rates by EOS diagnosis were as follows: 13/354 patients (3.6%) had neuromuscular scoliosis (NMS), 9/225 (4.0%) syndromic, 6/248 (2.4%) idiopathic, 3/135 congenital (2.2%), and 2/30 (6.6%) unknown etiology. MCGR was salvaged in 69% of NMS patients, 77% of syndromic patients, 100% of congenital patients, and 83% of idiopathic patients (83%). There were only four recurrent infections (2/13 NMS, 2/9 syndromic) and no differences in rates of recurrent infection between salvaged or replaced/exchanged MCGR. (p = 0.97).

CONCLUSION

Deep wound infection occurred in 3% of MCGR patients at a mean of 13.1 months. There were no significant differences in rates of recurrent infection between salvaged implants and those removed or exchanged.