Adolescent idiopathic scoliosis (AIS) treated with arthrodesis and posterior titanium instrumentation: 8 to 12 years follow up without late infection

Revision Surgery After Spinal Fusion in Adolescent Idiopathic Scoliosis

STUDY DESIGN

Retrospective Aanalysis of a Large Cohort of Cases.

OBJECTIVES

To explore the rate and cause of revision surgery after spinal fusion in adolescent idiopathic scoliosis(AIS).

METHODS

The patients diagnosed with AIS who underwent spinal fusion surgery in a single center from 2002 to 2018 were retrospectively analyzed. All the patients were followed up at least 2 years. The causes of revision surgery were analyzed and the incidence of revision surgery was counted.

RESULTS

A total of 1816 AIS patients were included in the study. After an average of 8.5 years (range 3-18 years) follow-up, a total of 51 patients underwent 54 revision operations. The overall revision rate is 2.8%. The revision rate of combined approach (anterior and posterior) and anterior approach was 6.6% (8/122), and the revision rate of posterior approach was 2.5% (43/1694). The most common causes of revision were malposition of implants/implants failure (37%), followed by poor wound healing/ infection (23%). Spinal decompensation, adding on and proximal junctional kyphosis (PJK) accounted for 20%. The compensatory curve continued to worsen after selective fusion accounted for 14% and finally the discomfort with the implants accounted for 6%.

CONCLUSIONS

The overall revision rate of spinal fusion for AIS is 2.8%. The implants and incision problems were the most common causes of revision surgeries.

Late spinal infections following posterior spinal fusion in pediatric deformities: treatment using single-stage titanium implant exchange

PURPOSE

Late infection following posterior spinal fusion (PSF) for deformity is a leading cause of revision. The purpose of this study is to evaluate clinical and radiographic outcomes following a single-stage debridement and exchange of spinal implants with titanium in adolescent patients with late-onset infections following PSF METHODS: A retrospective review of prospectively collected data of adolescent patients with spinal deformity, who were surgically treated with PSF was collected. Patients were included for the study if they developed late arising infection (> 1 year after index posterior fusion for the deformity) from 2006-2019. Treatment consisted of irrigation, debridement, implant exchange with titanium screws and rods, and antibiotics. Parameters evaluated include radiographic Cobb angles, operative data, and clinical data, all at minimum 2-year follow-up.

RESULTS

31 patients (29 with AIS and 2 with Scheuermann's kyphosis) developed late spinal infections. Mean age was 11.4 ± 2.3 years, 84% female, mean time from index surgery was 52.5 months. 25 had all stainless steel implants and 6 had cobalt chrome during the index procedure. Positive cultures were obtained in 5 patients (2 Staphylococcus Aureus, 1 Staphylococcus epidermidis, 1 Peptostreptococcus, 1 Pseudomonas aeruginosa) with cultures followed till 7 days post-operatively. At 2-years following the exchange, there was no change in coronal and sagittal alignment. Three (9%) patients developed subsequent infection necessitating implant removal.

CONCLUSION

A single-stage procedure consisting of implant removal, irrigation, and debridement, and replacement with all titanium implants is an effective treatment strategy in patients developing late wound infection following PSF with regards to maintenance of curve correction and minimizing recurrent infections.

A systematic scoping review and textual narrative synthesis of long-term health-related quality of life outcomes for adolescent idiopathic scoliosis

INTRODUCTION

Idiopathic scoliosis is a musculoskeletal condition leading to deformity of the spinal column. There is strong evidence reporting short term health-related quality of life outcomes, but less is known about the longer-term impact of adolescent idiopathic scoliosis (AIS). This paper reports the current evidence on long-term non-clinical outcomes of AIS.

METHOD

A systematic scoping literature review combining descriptive and textual narrative synthesis was undertaken. Studies were included if they: sampled or followed up participants at least 10 years after diagnosis and/or treatment, contained health-related quality of life data that could be extracted, where the intervention (or diagnosis in the case of untreated) occurred after 1980, and where data was extractable for modern rod and screw or fusion techniques, non-surgical interventions or untreated patients.

RESULTS

Twenty-three studies were included. Overall, the HRQOL measures utilised by these studies suggest that HRQOL is not related to participant demographics or AIS characteristics or type or extent of surgical intervention. Some studies suggest that those with AIS scored worse than controls.

DISCUSSION

Results suggest that AIS participants had a generally good quality of life, although this was often worse than those without AIS. No other clear relationships were found. The available literature fails to address more fundamental questions about how HRQOL is conceptualised for those with AIS, and there is value in pursuing qualitative inquiry in this area.

Comparing short-term AIS post-operative complications between ACS-NSQIP and a surgeon study group

STUDY DESIGN

Prospective cohort review.

OBJECTIVE

To compare two AIS databases to determine if a performance improvement-based surgeon group has different outcomes compared to a national database. The American College of Surgeon's National Quality Improvement Program (ACS-NSQIP) and a surgeon study group (SG) collect prospective data on AIS surgery outcomes. NSQIP offers open enrollment to all institutions, and SG membership is limited to 15 high-volume institutions, with a major initiative to improve surgeon performance. While both provide important outcome benchmarks, they may reflect outcomes that are not relatable nationwide.

METHODS

The ASC-NSQIP Pediatric Spine Fusion and SG database were queried for AIS 30- and 90-day complication data for 2014 and 2015. Prospective enrollment and a dedicated site coordinator with rigorous data quality assurance protocols existed for both registries. Outcomes were compared between groups with respect to superficial and deep surgical site infections (SSI), neurologic injury, readmission, and reoperation.

RESULTS

There were a total of 2927 AIS patients included in the ASC-NSQIP data and 721 in the SG database. Total complication rate was 9.4% NSQIP and 3.6% SG. At 90 days, there were fewer surgical site infections reported by SG than ASC-NSQIP (0.6% vs. 1.6%, p = 0.03). Similarly, there were less spinal cord injuries (0.8% vs 1.5%, p = 0.006), 30-day readmissions (0.8% vs. 2.6%, p = 0.002), and 30-day reoperations (0.6% vs. 1.7%, p = 0.02) in the SG cohort.

CONCLUSIONS

Comparison of these two data sets suggests a range of complications and readmission rates, with the SG demonstrating lower values. These results are likely multi-factorial with the performance improvement initiative of the SG playing a role. Understanding the rate and ultimate risk factors for readmission and complications from big data sources has the potential to further drive quality improvement.

LEVEL OF EVIDENCE

III.

Implant density is not related to patient-reported outcome in the surgical treatment of patients with idiopathic scoliosis

Aims

There is little information about the optimum number of implants to be used in the surgical treatment of idiopathic scoliosis. Retrospective analysis of prospectively collected data from the Swedish spine register was undertaken to discover whether more implants per operated vertebra (implant density) leads to a better outcome in the treatment of idiopathic scoliosis. The hypothesis was that implant density is not associated with patient-reported outcomes, the correction of the curve or the rate of reoperation.

Patients and Methods

A total of 328 patients with idiopathic scoliosis, aged between ten and 20 years at the time of surgery, were identified in the Swedish spine register (Swespine) and had patient reported outcomes including the Scoliosis Research Society 22r instrument (SRS-22r) score, EuroQol 5 dimensions quality of life, 3 level (EQ-5D-3L) score and a Viual Analogue Score (VAS) for back pain, at a mean follow-up of 3.1 years and reoperation data at a mean follow-up of 5.5 years. Implant data and the correction of the curve were assessed from radiographs, preoperatively and a mean of 1.9 years postoperatively. The patients were divided into tertiles based on implant density. Data were analyzed with analysis of variance, logistic regression or log-rank test. Some analyses were adjusted for gender, age at the time of surgery, the flexibility of the major curve and follow-up.

Results

The mean number of implants per operated vertebra in the low, medium and high-density groups were 1.36 (1.00 to 1.54), 1.65 (1.55 to 1.75) and 1.91 (1.77 to 2.00), respectively. There were no statistically significant differences in the correction of the curve, the SRS-22r total score, EQ-5D-3L index or number of reoperations between the groups (all p > 0.34). In the SRS-22r domains, self-image was marginally higher in the medium implant density group (p = 0.029) and satisfaction marginally higher in the high implant density group (p = 0.034).

Conclusion

These findings suggest that there is no clear advantage in using a high number of implants per operated vertebra in the surgical treatment of patients with idiopathic scoliosis. Cite this article: Bone Joint J 2018;100-B:1080–6.

5-Year Reoperation Risk and Causes for Revision After Idiopathic Scoliosis Surgery

STUDY DESIGN

An actuarial "survivorship" analysis.

OBJECTIVE

The aim of this study was to define the incidence and cause of surgical revision 5 years after scoliosis surgery.

SUMMARY OF BACKGROUND DATA

Data on contemporary revision surgery rates after idiopathic scoliosis surgery beyond the 2 years postoperatively in the adolescent and young adult population are limited.

METHODS

Patients enrolled in a prospective, multicenter, idiopathic scoliosis surgical registry from 1995 to 2009 were reviewed. Any spine reoperation was defined as a "terminal event." An actuarial survivorship analysis that adjusts for patients lost to follow-up was performed to determine cumulative survival. Time intervals were defined as 0 to <3 months, 3 months to <1 year, 1 to <2 years, 2 to <5 years, and 5 to 10 years. Registry data and radiographs were reviewed and five categories for reoperation assigned: 1) implant failure and/or pseudarthrosis, 2) implant misplacement and/or prominence, 3) wound complication and/or infection, 4) residual deformity and/or progression, and 5) other.

RESULTS

One thousand four hundred thirty-five patients from 12 sites were included. The majority were female (80%), with major thoracic curves (76% Lenke 1-4), and average age of 15 ± 2 years (10-22) at surgery. Most had posterior spinal instrumentation and fusion (81%). At this time, 75 (5.2%) patients required reoperation. Twenty-two occurred within 3 months postop, 10 more before 1 year, 12 more before 2 years, another 20 by 5 years, and 10 more after 5 years. This corresponded to an actuarial cumulative survival of 98.3% at 3 months, 97.5% at 1 year, 96.6% at 2 years, 93.9% at 5 years, and 89.8% at the final interval (5-10 yrs).

CONCLUSION

Revisions for scoliosis continue to occur well after 2 years with a 5-year survivorship of 93.9%. Reasons for reoperation are not uniformly distributed over time, with implant-related issues and infection the leading cause for early revision, while late infection was the most common cause after 2 years. Long-term follow-up of these postoperative patients remains important.

LEVEL OF EVIDENCE

3.

Adolescent idiopathic scoliosis: surgical treatment and quality of life

OBJECTIVES

The purpose of this study was to determine the influence of perioperative factors and their impact on clinical and functional outcomes in Brazilian patients with adolescent idiopathic scoliosis (AIS).

METHODS

We performed a prospective study with 49 consecutive AIS patients who underwent spine fusion and had a minimum 2 year follow-up. Clinical and radiographic data were correlated to SRS-30 scores in order to predict postoperative results.

RESULTS

There was a negative association between patient age at the time of surgery and back pain. We also observed higher scores in the "satisfaction" domain in patients who underwent surgery after 15 years of age (p < 0.05). The average SRS-30 "mental health" score was significantly higher in males than in females (p= 0.035). Patients treated with braces had worse results than those who did not use them (p= 0.005).

CONCLUSIONS

Posterior spine fusion led to improvement of all domains of the SRS-30 questionnaire. Clinical results were influenced by age, sex and the use of braces prior to surgery. There was no correlation between curve correction and presence of perioperative complications. Level of Evidence IV, Case Series.

Local and systemic metal ion release occurs intraoperatively during correction and instrumented spinal fusion for scoliosis

STUDY DESIGN

Prospective pilot study.

OBJECTIVES

The aim of this study was to measure titanium, niobium and aluminium levels in various intraoperative and postoperative samples to determine patterns of metal ion release that occur within the first month following instrumented spinal fusion. Raised serum metal ion levels are reported following instrumented spinal fusion in adolescent idiopathic scoliosis. The exact topological origin and chronology of metal ion release remains conjectural. Recent literature suggests an immediate rise in serum metal levels within the first postoperative week.

METHODS

Titanium, niobium and aluminium levels were measured before, during and after surgery in serum and local intraoperative fluid samples obtained from two pediatric patients undergoing posterior correction and instrumentation for scoliosis.

RESULTS

Measurable metal ion levels were detected in all local samples obtained from wound irrigation fluid, cell saver blood, and fluid that immersed metal universal reduction screw tabs. Postoperative serum metal ion levels were elevated compared to baseline preoperative levels. In general, metal ion levels were considerably higher in the intraoperative fluid samples compared to those observed in the serum levels.

CONCLUSION

Our findings of contextually high metal ion concentrations in intraoperative and early postoperative samples provide further empirical support of a 'putting-in' phenomenon of metal ion release following instrumented spinal fusion. This challenges existing beliefs that metal ion release occurs during an intermediate 'wearing-in' phase. We recommend thorough irrigation of the operative site prior to wound closure to dilute and remove intraoperative metal ion debris. Possibilities of filtering trace metal ions from cell saver content may be considered.

Loss of correction in spinal cord injury-related scoliosis after pedicle screw fixation

PURPOSE

Spinal cord injury (SCI) in the pediatric population is an infrequent but clinically important disease to scoliosis surgeons. Spinal deformity after SCI is extremely common and almost uniformly develops in patients being injured before the growth spurt. Most treatment paradigms extrapolate management from both the adult literature as well as adolescent idiopathic scoliosis data. Since these patient populations are different in many respects, we sought out to investigate the rates of loss of correction over time as well as the factors associated with loss of correction in pediatric patients undergoing pedicle screw fixation for treatment of SCI-related scoliosis.

METHODS

All consecutive pediatric patients with spinal cord injury and paralytic scoliosis managed with pedicle screw constructs were identified at a single institution. Clinical and radiographic parameters were reviewed and analyzed with specific focus on parameters associated with loss of correction at an average follow-up of 2 years.

RESULTS

Approximately 15 % of patients had a loss of correction of greater than 10° of Cobb angle. Postoperative sagittal imbalance was found to be significantly greater in patients who lost greater than 10° of correction compared to patients who did not lose correction (53.6 ± 39.9 vs 4.3 ± 41.3 mm, p = 0.02).

CONCLUSIONS

Correction of patients with paralytic associated scoliosis should aim for a neutral sagittal balance in order to prevent postoperative loss of correction. Further study is needed on this subgroup of patients with scoliosis given the differences in strategies needed to correct and maintain their deformity correction.

Prevalence of intraoperative tissue bacterial contamination in posterior pediatric spinal deformity surgery

STUDY DESIGN

Retrospective case control study.

OBJECTIVE

To determine prevalence and risk factors for intraoperative bacterial contamination in posterior spinal deformity surgery.

SUMMARY OF BACKGROUND DATA

The prevalence of deep surgical site infection in pediatric spinal deformity surgery varies from 1% to 14%. Little evidence exists about the incidence and role of intraoperative bacterial contamination.

METHODS

A total of 114 cases of pediatric posterior instrumented deformity surgery were retrospectively identified. All patients received preoperative and every 4-hour intraoperative antibiotics and 3M Ioban 2 Antimicrobial Incise Drape. Preoperative photographs of patients' backs were used to correlate presence of back acne with contaminant bacteria. Laboratory cultures were obtained from paraspinal muscle debrided before closure.

RESULTS

Of the 114 cultures obtained, 26 (23%) were positive in 21% of idiopathic, 37% of neuromuscular (P = 0.02), and 14% of congenital patients. Contaminant bacteria included Propionibacterium acnes (69%), Staphylococcus (23%), Coryneform (4%), and Clostridium (4%). P. acnes was seen only in children 11 years or older (P = 0.02) and only with back acne (P < 0.0001). Eight of 19 (42%) patients with pelvic fusion had positive cultures (P = 0.04) and all 8 were neuromuscular patients. Eighty-one percent of culture-positive patients were older than 11 years (P = 0.01). Three of 114 (2.7%) patients developed an early deep surgical site infection, all with positive cultures (P = 0.01).

CONCLUSION

Neuromuscular patients fused to the pelvis, children older than 11 years, and surgery duration greater than 6 hours were associated with positive cultures. Back acne is a preventable risk factor for P. acnes seeding. Intraoperative bacterial contamination indicates a need to consider the type of surgery and patient age to determine prophylactic antibiotics and other modalities to prevent infection.

Serum titanium, niobium, and aluminum levels after instrumented spinal arthrodesis in children

STUDY DESIGN

A prospective cohort study.

OBJECTIVE

To determine serum titanium, niobium, and aluminum levels in pediatric patients within the first postoperative year after instrumented spinal arthrodesis.

SUMMARY OF BACKGROUND DATA

Instrumented spinal arthrodesis is a common procedure to correct scoliosis and kyphosis. Titanium-based instrumentation is increasingly favored due to enhanced biomechanical properties, but concerns have arisen regarding metal debris release and the potential for local and systemic complications.

METHODS

The pattern of systemic metal release over time was evaluated by measuring serum titanium, niobium, and aluminum levels preoperatively and 1 week, 1 month, 6 months, and 12 months after instrumented spinal arthrodesis using a titanium alloy. Serum metal levels were measured using high-resolution inductively coupled plasma mass spectrometry.

RESULTS

Thirty-two patients were included in the study group. Mean age at surgery was 14.7 years. Preoperative and postoperative concentrations of serum titanium and niobium were significantly different (P = 0.0001). Median postoperative serum concentrations of titanium and niobium were elevated 2.4- and 5.9-fold above the normal range respectively with 95% and 99% of samples elevated postoperatively. A significant and rapid rise in serum titanium and niobium levels was observed within the first postoperative week, after which elevated serum levels persisted up to 12 months.

CONCLUSION

We report abnormally elevated serum titanium and niobium levels in patients with titanium-based spinal instrumentation up to 12 months. The long-term systemic consequences of debris generated by wear and corrosion of spinal instrumentation is unclear but concerning, particularly as these implants inserted into the pediatric population may remain in situ for beyond 6 decades.

Cotrel-dubousset instrumentation for the correction of adolescent idiopathic scoliosis. Long-term results with an unexpected high revision rate

Background

For many years, the CD instrumentation has been regarded as the standard device for the surgical correction of adolescent idiopathic scoliosis (AIS). Nevertheless, scientific long-term results on this procedure are rare. Therefore, we conducted a retrospective follow-up study of patients treated for AIS with CD instrumentation and spondylodesis.

Methods

A total of 40 patients with AIS underwent CD instrumentation in our department within 3 years and between 1990 and 1992. For the retrospective analysis, first all the patient documents were reviewed, and pre-/postoperative X-ray images as well as those at the latest follow-up were analysed. Furthermore, it was attempted to conduct a clinical survey using the SRS-24 questionnaire, which was sent to the patients after a preceding announcement on the phone.

Results

Radiologically, the frontal main curvature was improved from a preoperative angle of 69.2° to a postoperative angle of 35.4°, and the secondary curvature was improved from a preoperative angle of 42.6° to a postoperative angle of 20.5°. The latest radiological follow-up at average 57.4 months post surgery showed an average loss of correction of 9.6° (main curvature) and 4.6° (secondary curvature), respectively.

Within the first 30 days post surgery, 3 out of 40 patients (7.5%) received early operative revision for the dislocation of hooks or rods.

At an average of 45.7 months (range 11 to 142 months), 19 out of 40 patients (47.5%; including 2 patients with early revision) received late operative revisions: The reasons were late infection (10 out of 40 patients; 25%) with the development of fistulae (7 cases) or putrid secretion (3 cases), which was resolved with the complete removal of instrumentation after all. The average time until revision was 35.5 months (range 14 to 56 months) after CD instrumentation. Furthermore, complete implant removal was necessary in 8 out of 40 patients (20%) for late operate site pain (LOSP). The average time until removal of instrumentation was 62.7 months (range 18 to 146 months) post surgery; and one patient received partial device removal for prominent instrumentation 11 months post surgery. Altogether, only 22 out of 40 CD instrumentations (55%) were still in situ.

After an average period of 14.3 years post surgery, it was possible to follow-up 14 out of 40 patients (35%) using the SRS-24 questionnaire. The average score was 93 points, without showing significant differences between patients with or without their instrumentation in situ.

Conclusions

Retrospectively, we documented for the first time a very high revisions rate in patients with AIS and treated by CD instrumentation. Nearly half of the instrumentation had to be removed due to late infection and LOSP. The reasons for the high rate of late infections with or without fistulae and for LOSP were analysed and discussed in detail.

Long-term outcomes after posterior spine fusion for adolescent idiopathic scoliosis

PURPOSE OF REVIEW

To summarize recent literature regarding long-term follow-up after spinal fusion for patients with adolescent idiopathic scoliosis. In particular, this review includes a review of research which provides insight into long-term results after fusion using pedicle screw stabilization, a relatively new technique for which long-term follow-up is only recently available.

RECENT FINDINGS

The literature increasingly uses patient-derived questionnaires to report outcomes. Minor residual scoliosis after fusion does not adversely affect outcomes and is well tolerated by patients without causing functional limitations. In contrast, patients who are leaning forward after fusion ('positive sagittal balance') do worse as measured by validated outcomes instruments. Although patients who undergo long fusion have higher rates of disc degeneration on magnetic resonance imaging compared with the general population, this degeneration is most often clinically silent.

SUMMARY

The best available evidence suggests that most patients do well after posterior fusion for adolescent idiopathic scoliosis, although outcomes are adversely affected if patients develop positive sagittal balance. Continued surveillance will determine whether accelerated degeneration at unfused levels becomes symptomatic at longer-term follow-up or remains clinically silent.

Spinal loop rectangle and sub laminar wiring as a technique for scoliosis correction

BACKGROUND

Most literature popularizes the efficacy of third generation instrumentation in the surgical correction of spinal deformities. A cheap and effective scoliotic deformity correction method is reviewed in this article. The aim of this study is to evaluate the efficacy of spinal loop rectangle and sub laminar wires as a modality for spinal deformity correction and its co-relation with patients' satisfaction and clinical outcome.

MATERIAL AND METHODS

Thirty six patients of scoliotic spinal deformities with various etiologies (congenital-4, idiopathic- 25, neurofibromatosis-3, neuromuscular-2 and 'syndromic'-3) with ages ranging from 8 to 23 years underwent corrective posterior spinal arthrodesis with stainless steel Hartshill loop rectangle and sublaminar wires. Clinicoradiological evaluation was done at an average follow-up of 6 (1/2) years (min-2 (1/2), years). Along with clinicoradiological outcome, patient satisfaction (as per the SRS 24), was accounted.

RESULTS

Average preoperative Cobb's angle were 73.25 degrees in the entire group and 66.48 degrees in the idiopathic group. Average percentage correction was 64.34% in the entire group and the (average degree of correction was 47.13). In the idiopathic group, the respective values were 69.19% and 46 degrees . Loss of correction in the whole group was 2.2 degrees at two year follow up. Sagittal profiles, truncal balance were well corrected too; minimal complications were seen. Patient satisfaction results were encouraging in 36 patients as per - SRS24). About 80.2% patients were ready to undergo the same surgery if required. (SRS24).

CONCLUSION

Segmental spinal fixation with locally made spinal loop rectangle and sublaminar wires is comparable as a modality to correct scoliotic spinal deformities.