Aims. The aim of this retrospective study was to compare the correction achieved using a convex pedicle screw technique and a low implant density achieved using periapical concave-sided screws and a high implant density. We hypothesized that there would be no difference in outcome between the two techniques. Methods. We retrospectively analyzed a series of 51 patients with a thoracic adolescent idiopathic scoliosis. There were 26 patients in the convex pedicle screw group who had screws implanted periapically (Group 2) and a control group of 25 patients with bilateral pedicle screws (Group 1). The patients’ charts were reviewed and pre- and postoperative radiographs evaluated. Postoperative patient-reported outcome measures (PROMs) were recorded. Results. The number of implants (14.5 vs 17.1) and the implant density (1.5 vs 1.9) were significantly lower in Group 2 (p < 0.001). Operating time was 27 minutes shorter in Group 2 than in Group 1, with a mean of 217 minutes (SD 50.5; 120 to 346). The duration of surgery per instrumented vertebra was reduced by 19% in Group 2 (p = 0.011). No statistical difference was found in the postoperative Cobb angle, vertebral rotation, the relative correction achieved, or postoperative PROMs. Conclusion. Despite a lower implant density and achieving correction through a convex rod, surgical correction of the Cobb angle and vertebral body rotation was similar in both groups. Periapical pedicle screws and primary correction on the concave side do not seem to be mandatory in order to achieve good surgical results in idiopathic thoracic scoliosis. The operating time was shorter in the group with lower implant density. In conclusion, the technique provided good results and has the potential to reduce complications and costs. Cite this article: Bone Joint J 2021;103-B(3):536–541

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

The current trend in kyphosis correction is for “every level” instrumentation to achieve intraoperative stability, correction, fusion and implant longevity. We evaluate the medium term follow up of a low implant density (LID) construct. All patients with adolescent kyphosis (idiopathic or Scheurmann's) on our deformity database were identified. Radiographs and records were analysed for neurological complications, correction and revision. The constructs included were all pedicle screw anchors with multiple apical chevron osteotomies and a proximal and distal “box” of 6 to 8 screws. A four rod cantilever reduction manoeuvre with side to side connectors completed the construct. Kyphosis for any other cause was excluded. Follow up less than 12 months was excluded. 23 patients were identified with an average follow up 27 months (72 to 12 months) and a mean implant density of 1.1 (53.5% of “available” pedicles instrumented). There was 1 false positive neurophysiological event without sequelae (4%). There were no proximal junctional failures (0%). There were no pseudarthroses or rod breakages (0%). There was 1 loss of distal rod capture (early set screw failure) (4%). This was revised uneventfully. There were 4 infections requiring debridement (early series). Average initial correction was 44% (77.7 degrees to 43.5 degrees) with a 1% loss of correction at final follow up (43.5 to 44.0 degrees). The fulcrum bending correction index was 107% (based on fulcrum extension radiographs). 85% of curves had a fulcrum flexibility of less than 50%. The average cost saving compared to “every level “instrumentation was £5700 per case. This paper shows that a LID construct for kyphosis has technical outcomes as good as high density constructs. The obvious limitation of the study is the small number of patients in the cohort. The infection rates have improved with changes to perioperative process in the later series of patients. We do not believe these are a consequence of the construct itself

Objectives: To evaluate the early coronal and sagittal correction of main thoracic adolescent idiopathic scoliosis using pedicle screw instrumentation and to determine whether implant density influences correction. Methods and results: 49 consecutive patients with Lenke I main thoracic adolescent idiopathic scoliosis underwent single stage posterior correction and instrumented spinal fusion with pedicle screw fixation between 2006 and 2008. All surgeries were performed in a single institution by a single surgeon using identical surgical technique and type of instrumentation. Pre- and postoperative radiographs were analyzed. The pre-operative main thoracic curve of 60.0 ± 13.4° was corrected to 17.4 ± 6.9° (69.9% correction) on the post-operative radiographs. The pre-operative thoracic kyphosis of 20.0 ± 10.2° decreased to 11.6 ± 4.9° post-operatively. There was a significant correlation between decrease in sagittal kyphosis and magnitude of coronal Cobb angle correction (P = 0.002). There was no correlation between implant density and magnitude of coronal or sagittal curve correction, with and without curve flexibility taken into consideration. Conclusions: Pedicle screw constructs provided excellent coronal correction of thoracic idiopathic scoliosis, however this was at the expense of sagittal contour. Decrease in sagittal kyphosis correlated with magnitude of coronal correction. Bilateral segmental pedicle screw fixation did not improve curve correction compared with unilateral or alternate segmental fixation. Ethics approval: None required. Caldicott and Data Protection Approval No. 661. Interest Statement: None

The April 2024 Children’s orthopaedics Roundup. 360. looks at: Ultrasonography or radiography for suspected paediatric distal forearm fractures?; Implant density in scoliosis: an important variable?; Gait after paediatric femoral shaft fracture treated with intramedullary nail fixation: a longitudinal prospective study; The opioid dilemma: navigating pain management for children’s bone fractures; 12- to 20-year follow-up of Dega acetabuloplasty in patients with developmental dysplasia of the hip; Physeal fractures of the distal ulna: incidence and risk factors for premature growth arrest; Analysis of growth after transphyseal anterior cruciate ligament reconstruction in children; Management of lateral condyle humeral fracture associated with elbow dislocation in children: a retrospective international multicentre cohort study

Introduction. Thoracic pedicle screws have been proven to be safe and effective in the treatment of adolescent idiopathic scoliosis (AIS). However, the effect of the instrumentation alloy has not yet been investigated. We aimed to compare segmental versus non segmental thoracic pedicle screw instrumentation in patients with AIS. Methods. A consecutive series of 143 patients with AIS (Lenke classification 1–4) surgically treated from 1998 to 2005 by means of thoracic pedicle screws were retrospectively reviewed. Considering implant density (number of fixation anchors placed per available anchors sites; segmental =60% [S], non-segmental =60% [NS]) and implant alloy used (titanium [Ti] vs stainless steel [SS]) we divided the cohort into four groups: Ti-S (48 cases); Ti-NS (34 cases); SS-S (35 cases); and SS-NS (26 cases). Groups were similar for preoperative mean age, sex distribution, Risser sign, main thoracic curve, and thoracic kyphosis. Pearson correlation coefficient and univariate analysis of variance were used. Results. At a mean follow-up of 6·2 years (range 3–10) the overall final main thoracic curve correction was a mean of 61·4% (20–89), whereas the implant density within the major curve was 71% (15–100%). We recorded a significant correlation between implant density and percentage major curve correction (r=0·41, p<0·002); when the four groups were compared we noted that the SS-S group showed the greatest average correction (75%), followed by the Ti-S, SS-NS, and Ti-NS groups. We detected no significant differences between SS-S versus Ti-S versus SS-NS (r=0·002, p>0·05; r=0·13, p>0·05; r=0·07, p>0·01, respectively), whereas the Ti-NS group showed a statistically significant inferior percentage correction when compared with all other groups (average 52%; p<0·001). Nevertheless, no significant difference between groups was recorded on the SRS-30 assessment, showing a postoperative improvement in both self-image and satisfaction. Conclusions. When an SS instrumentation is used, non-segmental pedicle screw constructs seem to be equally effective as segmental instrumentations in obtaining satisfactory results in patients with main thoracic AIS. When the implant alloy used is titanium, an implant density of greater than 60% should be guaranteed so as to achieve similar results to those recorded in this study

Aim:. The introduction of novel systems for correction of scoliosis should be subject to critical analysis and based on patient benefit. Methods:. Retrospective analysis of prospective data from a single surgeon consecutive series of Lenke 1 type curves. The two cohorts compared K2M and AOUSS2. Pre and Post operation Cobb angle, flexibility, absolute correction rate, implant related correction, levels fused, implant density, implant cost and cost per Cobb improvement analysis were collected. Results:. A total of 26 patients were analysed, 13 in each group. Both groups were similar in pre-operative parameters. The mean age was 14.62 and 14.23 respectively. The mean pre-operation Cobb angle was 71 (96–53) K2M and 70 (85–56) AOUSS2 bending to 45 in each. The flexibility was similar as was the correction in both. Post op Cobb 28 (42–16) K2M and Cobb 28 (44–16) AOUSS2. The implant density and number of screws used was similar. The average cost per construct was £6554 for K2M and £6140 AOUSS2. Discussion:. Using these simple and immediate outcome measures and a grossly simplified cost analysis there was a cost difference of £5382 with no measurable clinical advantage or disadvantage in curves of similar flexibility. The cost per case is determined by implant density and curve flexibility. In the least complex of scoliosis cases there needs to be evidence of benefit to justify the increased resource allocation in a health care system that is not fiscally driven. Conflict Of Interest Statement: No conflict of interest

Increasing health care costs, limited resources and increased demand makes cost-effective and cost-efficient delivery of Adolescent Idiopathic Scoliosis (AIS) management paramount. Rising implant costs in deformity surgery have prompted justification of high implant density. The objective of this study was to analyse the costs of thoracoscopic scoliosis surgery, comparing initial learning curve costs with those of the established technique and to the costs involved in posterior instrumented fusion from the literature. 189 consecutive cases from April 2000 to July 2011 were assessed with a minimum of 2 years follow-up using a prospective database covering perioperative factors, clinical and radiological outcomes, complications and patient-reported outcomes. The patients were divided into three groups to allow comparison; 1. A learning curve cohort, 2. An intermediate cohort and 3. A third cohort using our established technique. Hospital finance records and implant manufacturer figures were corrected to 2013 costs. A literature review of AIS management costs and implant density in similar curve types was performed. The mean pre-op Cobb angle was 53°(95%CI 0.4) and was corrected postop to mean 22.9°(CI 0.4). The overall complication rate was 20.6%, primarily in the first cohort, with a rate of 5.6% in the third cohort. The average total costs were $46,732, operating room costs of $10,301 (22.0%) and ICU costs of $4620 (9.8%). The mean number of screws placed was 7.1 (CI 0.04) with a single rod used for each case giving average implant costs of $14,004 (29.9%). Comparison of the three groups revealed higher implant costs as the technique evolved to that in use today, from $13,049 in Group 1 to $14577 in Group 3 (P<0.001). Conversely operating room costs reduced from $10,621 in Group 1 to $7573 (P<0.001) in Group 3. ICU stay was reduced from an average of 1.2 to 0 days. In-patient stay was significantly (P=0.006) lower in Groups 2 and 3 (5.4 days) than Group 1 (5.9 days). Our thoracoscopic anterior scoliosis correction has evolved to include an increase in levels fused and reduction in complication rate. Implant costs have risen, however, there has been a concurrent decrease in those costs generated by operating room use, ICU and in-patient stay with increasing experience. Literature review of equivalent curve types treated posteriorly shows similar perioperative factors but higher implant density, 69–83% compared to the 50% in this study. Thoracoscopic Scoliosis surgery presents a low density, reliable, efficient and effective option for selected curves

Aims. We present the results of correcting a double or triple curve adolescent idiopathic scoliosis using a convex segmental pedicle screw technique. Patients and Methods. We reviewed 191 patients with a mean age at surgery of 15 years (11 to 23.3). Pedicle screws were placed at the convexity of each curve. Concave screws were inserted at one or two cephalad levels and two caudal levels. The mean operating time was 183 minutes (132 to 276) and the mean blood loss 0.22% of the total blood volume (0.08% to 0.4%). Multimodal monitoring remained stable throughout the operation. The mean hospital stay was 6.8 days (5 to 15). Results. The mean post-operative follow-up was 5.8 years (2.5 to 9.5). There were no neurological complications, deep wound infection, obvious nonunion or need for revision surgery. Upper thoracic scoliosis was corrected by a mean 68.2% (38% to 48%, p < 0.001). Main thoracic scoliosis was corrected by a mean 71% (43.5% to 8.9%, p < 0.001). Lumbar scoliosis was corrected by a mean 72.3% (41% to 90%, p < 0.001). No patient lost more than 3° of correction at follow-up. The thoracic kyphosis improved by 13.1° (-21° to 49°, p < 0.001); the lumbar lordosis remained unchanged (p = 0.58). Coronal imbalance was corrected by a mean 98% (0% to 100%, p < 0.001). Sagittal imbalance was corrected by a mean 96% (20% to 100%, p < 0.001). The Scoliosis Research Society Outcomes Questionnaire score improved from a mean 3.6 to 4.6 (2.4 to 4, p < 0.001); patient satisfaction was a mean 4.9 (4.8 to 5). . Conclusions. This technique carries low neurological and vascular risks because the screws are placed in the pedicles of the convex side of the curve, away from the spinal cord, cauda equina and the aorta. A low implant density (pedicle screw density 1.2, when a density of 2 represents placement of pedicle screws bilaterally at every instrumented segment) achieved satisfactory correction of the scoliosis, an improved thoracic kyphosis and normal global sagittal balance. Both patient satisfaction and functional outcomes were excellent. Cite this article: Bone Joint J 2017;99-B:1080–7

The June 2024 Children’s orthopaedics Roundup³⁶⁰ looks at: Proximal femoral unicameral bone cysts: is ESIN the answer?; Hybrid-mesh casts in the conservative management of paediatric supracondylar humeral fractures: a randomized controlled trial; Rate and risk factors for contralateral slippage in adolescents treated for slipped capital femoral epiphysis; CRP predicts the need to escalate care after initial debridement for musculoskeletal infection; Genu valgum in paediatric patients presenting with patellofemoral instability; Nusinersen therapy changed the natural course of spinal muscular atrophy type 1: what about spine and hip?; The necessity of ulnar nerve exploration and translocation in open reduction of medial humeral epicondyle fractures in children.

Aims

The outcome following the development of neurological complications after corrective surgery for scoliosis varies from full recovery to a permanent deficit. This study aimed to assess the prognosis and recovery of major neurological deficits in these patients, and to determine the risk factors for non-recovery, at a minimum follow-up of two years.

Aim:. To evaluate the effect of a stiffer rod in normalising thoracic hypokyphosis in adolescent idiopathic scoliosis (AIS). Methods:. A retrospective review of AIS cases performed at our institution was carried out. In order to reduce variability, the analysis included only Lenke 1 cases which had all pedicle screw constructs, with similar constructs and implant density. Cases that underwent anterior release were excluded. All cases had the same implant (Expedium 5.5, Depuy-Synthes, Raynham, USA). The rod material differed in that some cases had 5.5 titanium, whilst others had 5.5 cobalt chrome. The preoperative and postoperative sagittal Cobb angle was measured. Results:. 35 patients met the inclusion criteria. 15 had titanium rods and 20 had cobalt chrome rods. The mean fulcrum correction index was similar between groups. The preoperative coronal and sagittal Cobb was similar between the two groups. There was no statistically significant difference in the postoperative sagittal Cobb between the two groups (ANOVA one way test). Discussion:. Despite the theoretical advantage of a stiffer construct improving the sagittal profile in AIS, this study identified no such benefit despite closely matching the two groups. All pedicle screw constructs do not seem to improve the sagittal profile despite the use of a stiffer rod. Conflict of interest:. Depuy-Synthes fund a fellow in this unit. Conflict Of Interest Statement: No conflict of interest

To determine if the use of high density implants (i.e. high proportion of pedicle screws relative to number of spinal levels involved) causes significant loss of thoracic kyphosis and its effect on sagittal balance in adolescent idiopathic scoliosis. Retrospective analysis of pre and post-operative radiographs to assess sagittal balance and C7-L1 kyphosis angle. 17 patients (16 females, 1 male). All right sided single thoracic curves. All surgery performed by single surgeon (Senior author, ED). Comparison of pre and post operative sagittal balance and C7-L1 kyphosis angle. Assessment of implant density (i.e. proportion of pedicle screw relative to number of spinal levels involved in correction). 9 patients demonstrated improved sagittal balance following surgery. There was no significant difference (p value 0.83) between the pre and post op C7-L1 kyphosis angle. Mean angle pre op 28.9 (95% CI 20.3 to 37.5). Mean angle post op 29.6 (95% CI 22.2 to 37.0). No correlation identified between sagittal balance correction and kyphosis angle. Metal density ranged from 79-100%. Although the sample size in this series is modest, high density implants do not significantly affect the kyphosis angle in the operative management of adolescent idiopathic scoliosis in the thoracic spine

Objective. To determine if there is a differing effect between two spinal implant systems on sagittal balance and thoracic kyphosis in adolescent idiopathic scoliosis. Methods. Retrospective analysis of pre and post-operative radiographs to assess sagittal balance, C7-L1 kyphosis angles and metal implant density. Group 1 (Top loading system): 11 patients (9 females, 2 males) Single surgeon NB. Group 2 (Side loading system): 17 patients (16 females, 1 male) Single surgeon ED. Total 28 patients. All single right sided thoracic curves. Comparison of pre and postoperative sagittal balance and C7-L1 kyphosis angle for each spinal system. Assessment of implant density (i.e. proportion of pedicle screw relative to number of spinal levels involved in correction). Results. 16 patients demonstrated improved sagittal balance following surgery. There was no significant difference between the pre and post op C7-L1 kyphosis angle in either group (p value 0.06 and 0.83 respectively) although a greater discrepancy was noted in Group 1. In group 1, the mean angle pre op was 33.1 (95% CI 27.3 to 38.9) and post op was 26.2 (95% CI 22.5 to 29.9). In Group 2, the mean angle pre op was 28.9 (95% CI 20.3 to 37.5) and post op was 29.6 (95% CI 22.2 to 37.0). No correlation identified between sagittal balance correction and kyphosis angle. Metal density ranged from 60-100%. Conclusions. Although the numbers in this series are modest they do suggest that high density metal implants do not lead to a flatback deformity in the sagittal plane. There is no significant difference in the pre and post op kyphosis angles for either implant system used in this study although the results for Group 1 do approach statistical significance. Larger prospective multicentre studies are required to quantify the true significance of these results. Ethics Approval: Audit/Service Standard in Trust

Purpose of the study. To compare the effectiveness of unilateral and bilateral pedicle screw techniques in correcting adolescent idiopathic scoliosis. Summary of Background Data. Pedicle screw constructs have been extensively used in the treatment of adolescent patients with idiopathic scoliosis. It has been suggested that greater implant density may achieve better deformity correction. However, this can increase the neurological risk related to pedicle screw placement, prolong surgical time and blood loss and result in higher instrumentation cost. Methods. We reviewed the medical notes and radiographs of 139 consecutive adolescent patients with idiopathic scoliosis (128 female-11 male, prospectively collected single surgeon's series). We measured the scoliosis, thoracic kyphosis (T5-T12), and lumbar lordosis (L1-L5) before and after surgery, as well as at minimum 2-year follow-up. SRS 22 data was available for all patients. Results. All patients underwent posterior spinal arthrodesis using pedicle screw constructs. Mean age at surgery was 14.5 years. We had 2 separate groups: in Group 1 (43 patients) correction was performed over 2 rods using bilateral segmental pedicle screws; in Group 2 (96 patients) correction was performed over 1 rod using unilateral segmental pedicle screws with the 2. nd. rod providing stability of the construct through 2-level screw fixation both proximal and distal. Group 1. Mean Cobb angle before surgery for upper thoracic curves was 37°. This was corrected by 71% to mean 11° (p<0.001). Mean Cobb angle before surgery for main thoracic curves was 65°. This was corrected by 71% to mean 20° (p<0.001). Mean Cobb angle before surgery for thoracolumbar/lumbar curves was 60°. This was corrected by 74% to mean 16° (p<0.001). No patient lost >2° correction at follow-up. Mean preoperative thoracic kyphosis was 24° and lumbar lordosis 52°. Mean postoperative thoracic kyphosis was 21° and lumbar lordosis 50° (p>0.05). Mean theatre time was 5.5 hours, hospital stay 8.2 days and intraoperative blood loss 0.6 blood volumes. Complications: 1 transient IOM loss/no neurological deficit; 1 deep wound infection leading to non-union and requiring revision surgery; 1 rod trimming due to prominent upper end. Mean preoperative SRS 22 score was 3.9; this improved to 4.5 at follow-up (p<0.001). Pain and self-image demonstrated significant improvement (p=0.001, p<0.001 respectively) with mean satisfaction rate 4.9. Group 2. Mean Cobb angle before surgery for upper thoracic curves was 42°. This was corrected by 52% to mean 20° (p<0.001). Mean Cobb angle before surgery for main thoracic curves was 62°. This was corrected by 70% to mean 19° (p<0.001). Mean Cobb angle before surgery for thoracolumbar/lumbar curves was 57°. This was corrected by 72% to mean 16° (p<0.001). No patient lost >2° correction at follow-up. Preoperative scoliosis size for all types of curves correlated with increased surgical time (r=0.6, 0.4). Mean preoperative thoracic kyphosis was 28° and lumbar lordosis 46°. Mean postoperative thoracic kyphosis was 25° and lumbar lordosis 45° (p>0.05). Mean theatre time was 4.2 hours, hospital stay 8.4 days and intraoperative blood loss 0.4 blood volumes. Complications: 1 deep and 1 superficial wound infections treated with debridement; 1 transient brachial plexus neurapraxia; 1 SMA syndrome. Mean preoperative SRS 22 score was 3.7; this improved to 4.5 at follow-up (p<0.001). Pain, function, self-image and mental health demonstrated significant improvement (p<0.001 for all parameters) with mean satisfaction rate 4.8. Comparison between groups showed no significant difference in regard to age at surgery, preoperative and postoperative scoliosis angle for main thoracic and thoracolumbar/lumbar curves, as well as SRS scores and length of hospital stay. Better correction of upper thoracic curves was achieved in Group 1 (p<0.05), but upper thoracic curves in Group 2 were statistically more severe before surgery (p<0.05). Increased surgical time and blood loss was recorded in Group 1 (p<0.05, p=0.05 respectively). The implant cost was reduced by mean 35% in Group 2 due to lesser number of pedicle screws. Conclusion. Unilateral and bilateral pedicle screw instrumentation has achieved excellent deformity correction in adolescent patients with idiopathic scoliosis, which was maintained at follow-up. This has been associated with high patient satisfaction and low complication rates. The unilateral technique using segmental pedicle screw correction has reduced surgical time, intraoperative blood loss and implant cost without compromising surgical outcome for the most common thoracic and thoracolumbar/lumbar curves. The bilateral technique achieved better correction of upper thoracic scoliosis

Aims

The purpose of this study was to evaluate the incidence and analyze the trends of surgeon-reported complications following surgery for adolescent idiopathic scoliosis (AIS) over a 13-year period from the Scoliosis Research Society (SRS) Morbidity and Mortality database.

Aims

It is uncertain whether instrumented spinal fixation in nonambulatory children with neuromuscular scoliosis should finish at L5 or be extended to the pelvis. Pelvic fixation has been shown to be associated with up to 30% complication rates, but is regarded by some as the standard for correction of deformity in these conditions. The incidence of failure when comparing the most caudal level of instrumentation, either L5 or the pelvis, using all-pedicle screw instrumentation has not previously been reported. In this retrospective study, we compared nonambulatory patients undergoing surgery at two centres: one that routinely instrumented to L5 and the other to the pelvis.

Determine the detection rate of modern spinal implants using the current technology. There is a paucity of data regarding detection rates of modern spinal implants using modern walk-through pulsed archway metal detectors (AMDs). No published reports compare detection capability with hand-held metal detectors (HHMDs). ex-vivo & in-vivo comparison of detection rates using AMD & HHMD (set to maximum DoT sensitivities), in patients of varying Body Mass Index (BMI), implants, implant mass/density and alloys. 40 patients with: lumbar disc replacement (CoCr) (n=8), cervical disc replacement (CoCr) (1), posterior deformity instrumentation (17), anterior deformity instrumentation (2), anterior reconstruction (2), PLIF (6), interspinous distraction device (1), anterior cervical plate (2) ALIF (1), All implants were titanium unless indicated. Mean metal mass was 98g (range 6g-222g). The AMD did not detect any instrumentation individually or in combination up to a titanium mass totalling 215g. The HHMD detected all instrumentation at a distance of 5cm; with the minimum mass being 2g. No implants were detected in patients by the AMD. The HHMD did not detect any anterior lumbar or thoracic surgical implants. It detected anterior cervical implants. The HHMD detected all posterior surgical implants. There was no significant relationship between detection, BMI, total metal mass, and metal density/segment. AMD detectors do not detect modern spinal implants. HHMD detect all modern posterior spinal implants; this has implications for patient documentation