Metallosis is commonly associated with magnetically controlled growing rods; results from an independent multicentre explant database.

PURPOSE: Determine the incidence of metallosis around MAGEC rods. METHODS: A multicentre explant database was searched to identify cases with complete intraoperative findings at rod removal. Surgeons removing rods detailed the presence or absence of tissue metallosis associated with rods. More recently surgeons measured the 'length' of tissue metallosis. Prior to rod disassembly, the majority underwent testing with an external remote controller (ERC). The impact of clinical and explant variables on metallosis was assessed. RESULTS: Sixty-six cases were identified. Mean age at insertion was 8.1 ± 2.3 years with mean duration of implantation 37.6 ± 15.1 months. Tissue metallosis was noted at revision surgery in 52/66 cases (79%). Metallosis was noted more commonly when rods were removed during fusion surgery than rod removal/exchange (97% vs. 58% (p = < 0.01)). The mass at insertion was greater in cases with metallosis (25.9 ± 7.8 kg vs. 21.1 ± 6.2 kg, p = 0.04). Length of tissue metallosis was reported for 45 rods, median 9 cm (range 1-25). Metallosis was noted in 43/59 (73%) rods that produced no force and 22/30 (73%) rods that produced some force on ERC activation (p = 0.96). Wear debris was found within the actuator in all rods, and all but 3 rods had damaged O-rings. CONCLUSION: MAGEC rods are associated with tissue metallosis in the majority of cases. It is seen with functional rods as well as failed rods and appears related to wear debris within the actuator and high rates of O-ring failure. Until the implications of metal debris in children are known, we urge caution with the use of this implant.

The NuVasive MAGEC Rod Urgent Field Safety Notice Concerning Locking Pin Fracture: How Does Data From an Independent Explant Center Compare?

STUDY DESIGN: Analysis of explanted MAGnetic Expansion Control (MAGEC) growing rods. OBJECTIVE: The aim of this study was to quantify the rate of locking pin breakage in explanted MAGEC rods and compare with the manufacturer's data. SUMMARY OF BACKGROUND DATA: On June 25, 2019, NuVasive released an Urgent Field Safety Notice stating that MAGEC rods manufactured before March 26, 2015 had a higher than expected locking pin breakage rate of 5%. For rods made on or after that date, no pin breakages had occurred. METHODS: From our independent explant database of 139 explanted MAGEC rods supplied from 10 UK spinal centers (Belfast, Bristol, Birmingham, Edinburgh, Exeter, Leeds, Newcastle, Nottingham, Oxford, and Sheffield) and one Danish center (Aarhus), we divided the rods into those manufactured before March 26, 2015, and those manufactured on or after that date. MAGEC rods were cut open to fully assess internal components including locking pins. From each of the two cohorts, 10 locking pins were selected at random and their diameters were measured using a micrometer. RESULTS: One hundred and five explanted MAGEC rods were made before March 26, 2015 and could be disassembled to allow the locking pin to be examined. Fifty-nine percent (62/105) of these locking pins had fractured. For the MAGEC rods manufactured on or after March 26, 2015, 21% (6/29) were found to have fractured locking pins. Locking pins in MAGEC rods made on or after March 26, 2015 were of a stronger material and a larger diameter. CONCLUSION: Fifty-nine percent of the locking pins in MAGEC rods manufactured before March 26, 2015 had fractured, far greater than the 5% stated in the Urgent Field Safety Notice. Locking pin fracture still occurred in MAGEC rods manufactured on or after that date, in 21% of cases. This contrasted with the 0% reported by the manufacturer. LEVEL OF EVIDENCE: 4.

Spinal Lengthening With Magnetically Controlled Growing Rods: Data From the Largest Series of Explanted Devices.

STUDY DESIGN: Laboratory analysis of explanted MAGnetic Expansion Control (MAGEC) rods. OBJECTIVE: The aim of this study was to identify the in vivo lengthening of MAGEC rods. SUMMARY OF BACKGROUND DATA: Little data is available regarding the lengthening achieved by MAGEC rods. METHODS: Cases were identified from the largest series of independently analyzed explanted MAGEC rods. The in vivo growth of rods was determined by the distance between the first "growth mark" and the actuator. The instrumented spinal lengthening was calculated for each construct. Constructs were considered functional if all rods could lengthen with external remote controller activation and no rods were "telescoping". RESULTS: Fifty-five MAGEC constructs (99 rods) from 53 patients treated at 10 centers were included. The mean age at insertion was 8.5 years with rods implanted a mean of 35 months. Sixty rods were suitable for analysis with mean lengthening 21.7 mm, 8.9 mm/year. Of these 60 rods, three were maximally distracted. Mean instrumented spinal lengthening for 38 suitable cases was 22.1 mm, 8.4 mm/year. This was positively correlated with the duration of implantation (r = 0.34, P = 0.04) but negatively with patient age at insertion (r = -0.35, P = 0.03). The rate of instrumented spinal lengthening was negatively correlated with duration of implantation (r = -0.47, P = 0.004). Of 55 constructs, 34 were nonfunctional at time of removal with nine functional and 12 indeterminate. Functional constructs had been implanted significantly less time (20.0 vs. 39.7 months, P < 0.001) and lengthened less than those nonfunctional (12.3 mm vs. 23.3 mm, P = 0.04). CONCLUSION: This multicenter explant study represents the largest cohort managed with MAGEC rods reported. Rods are very rarely removed having fully lengthened with mean instrumented spinal growth of 22 mm over the implant's life. This may be explained by a high rate of lengthening mechanism failure in received rods after around 3 years in vivo. Our findings question the effectiveness of the MAGEC system and mandate urgent comparative clinical studies. LEVEL OF EVIDENCE: 4.

Spondylodiscitis due to Prevotella associated with ovarian mass--a rare case report and review of literature.

BACKGROUND: Spondylodiscitis is commonly caused by aerobic bacteria. Of all the spinal infections, anaerobic organisms account for less than 3% and are usually seen in postoperative patients. CASE DESCRIPTION: We report a rare case of spontaneous onset of spondylodiscitis caused by anaerobe Prevotella that led to the diagnosis of serous cystadenofibroma of the ovaries. CONCLUSION: The finding of Prevotella species in musculoskeletal infection should prompt investigation of the genitourinary system.

Recovery of pulmonary function following endoscopic anterior scoliosis correction: evaluation at 3, 6, 12, and 24 months after surgery.

STUDY DESIGN: A series of patients with scoliosis undergoing endoscopic anterior instrumentation and fusion undertaking repeated pulmonary function assessments. OBJECTIVE: To assess recovery of pulmonary function in the 2 years following endoscopic anterior scoliosis correction. SUMMARY OF BACKGROUND DATA: Recent studies have found that pulmonary function returns to preoperative levels 12-24 months following endoscopic anterior scoliosis correction, and a small improvement in forced expiratory volume (FEV1) has also been reported. METHODS: A series of 44 patients with endoscopic anterior scoliosis correction had pulmonary function tests before surgery, and at 3, 6, 12, and 24 months after surgery. Forced vital capacity (FVC), FEV1, and total lung capacity (TLC) were measured. Nonparametric statistical analysis was used to investigate changes in pulmonary function between successive assessments. RESULTS: Pulmonary function decreased by approximately 10% at 3 months after surgery. At 24 months after surgery, FVC and FEV1 recovered to 5% to 8% higher than preoperative levels, while TLC returned to preoperative levels. Statistically significant improvements in most pulmonary function values occurred between 3 and 6, and 6-12 months. Improvements in mean FVC, FEV1, and TLC continue between 12 and 24 months, although only the increase in absolute FVC for this time is statistically significant. CONCLUSIONS: Endoscopic anterior scoliosis surgery has no lasting negative effect on pulmonary function, and with prolonged follow-up, pulmonary capacity improves beyond preoperative levels.

Student and faculty issues in distance education occupational safety and health graduate programs.

PROBLEM: There is increasing interest in delivering degree programs without requiring students to attend traditional classroom-based classes. There are many differences between classroom and distance courses that must be addressed to have effective distance programs. METHOD: Occupational safety and health faculty and occupational safety and health professionals were surveyed to determine the need for graduate occupational safety and health programs, delivered by means of distance education, and the best means to deliver the program from the perspective of faculty and working occupational safety and health professionals. RESULTS: Adequate time is the largest problem issue for potential students and the distance student's needs must be considered when developing program policies and procedures. Faculty must be sufficiently trained in pedagogy, technology, and communications so that they have the same comfort level with this method of instruction as they do for the more familiar classroom, and technical and instructional support personnel need to be readily available to work with the faculty and support course development. IMPACT ON INDUSTRY: Findings indicate that there is interest in a distance education-based program and it is believed that industry will be positively impacted as educational opportunities expand for working professionals.