The adjunct use of descending neurogenic-evoked potentials when transcranial motor-evoked potentials degrade into warning criteria in pediatric spinal deformity surgery: minimizing false-positive events

PURPOSE

This studies objective was to evaluate the utility of descending neurogenic-evoked potentials (DNEPs) in the setting of transcranial motor-evoked potentials (TCeMEPs) degradation into warning criteria during pediatric spinal deformity surgery.

METHODS

An institutional spinal cord monitoring database was queried to identify all primary and revision pediatric spinal deformity cases, < / = 21 years of age performed from 1/2006 to 12/2021, in which TCeMEPs were the primary motor tract assessment modality which degraded into warning criteria, with subsequent initiation of adjunct DNEPs.

RESULTS

Fourteen surgical cases (0.42%; 3351 total cases) in fourteen patients met inclusion criteria. Mean age was 13.2 years (7.5-21.3).

DIAGNOSES

syndromic (n = 7), kyphosis (n = 3), congenital (n = 2), and idiopathic (n = 2). Three-column osteotomies (3CO)were done in eight patients. TCeMEPs degraded into warning criteria during screw placement (n = 7), 3CO performance/closure (n = 4), or deformity correction (n = 3). DNEPs were present in all cases of warning-criteria TCeMEPs and one case had degradation of DNEPs. Intraoperative Stagnara wake-up tests were performed in only 2/14 cases, with one transient new neurologic deficit (NND). In this specific scenario, DNEPs sensitivity was 50%, specificity 100%, positive predictive value 100%, and negative predictive value 92% to detect aNND.

CONCLUSION

DNEPs were useful in assessing spinal cord function in the setting of TCeMEP data degradation in complex pediatric deformity surgeries. DNEPs demonstrated a higher specificity and positive predictive value in this clinical setting than TCeMEPs when assessing long-term neurologic function after surgery. Based on this small cohort, DNEPs appear to be a useful adjunct modality to TCeMEPs, in this challenging clinical scenario.

Posterior spinal fusion with lowest instrumented vertebra at L4 in idiopathic scoliosis: optimizing radiographic outcomes using pre-operative flexibility radiographs

PURPOSE

In idiopathic scoliosis (IS), there is general agreement ending PSFs at L3 or more cranial is preferred to optimize spinal motion, and extending PSFs to L4 may be necessary; however, this may also cause coronal imbalance or caudal disc wedging post-operatively due to leveling of L4 tilt. The purpose of this study was to identify a pre-operative radiographic measurement, which can be used to quantify the optimal amount of L4 tilt for ideal post-operative radiographic alignment.

METHODS

The study was a retrospective analysis of IS patients who underwent PSF to L4, with minimum 2-year follow-up post-operatively. Optimal outcome was defined by coronal balance, and L4-5 and L5-S1 disc wedging.

RESULTS

44 patients (84% females, mean age 13.6 years) were included. Analysis of pre-operative flexibility radiographs determined only the L5 tilt on the right side-bending (RSB) radiograph correlated with optimal outcome 2 (p = 0.03). To confirm the validity, the RSB value was subtracted from the post-operative C7-L4 tilt and the odds ratio analysis which was significantly correlated with optimal outcome 1 at final follow-up (OR 1.04, 95% CI 1-1.09).

CONCLUSIONS

In PSF to L4 for IS, L5 tilt measured from the pre-operative supine RSB radiograph can be used to optimize radiographic outcomes. Matching the pre-operative L5 tilt on RSB radiograph by leaving L4 tilted at the end of the PSF construct during surgery, quantified by the C7-L4 acute angle tilt, appears to be a useful method to achieve the desired post-operative alignment.

Rib-to-spine and rib-to-pelvis magnetically controlled growing rods: does the law of diminishing returns still apply?

PURPOSE

The Law Of Diminishing Returns (LODR) has been demonstrated for traditional growing rods, but there is conflicting data regarding the lengthening behavior of Magnetically Controlled Growing Rods (MCGR). This study examines a cohort of patients with early-onset scoliosis (EOS) with rib-to-spine or rib-to-pelvis-based MCGR implants to determine if they demonstrate the LODR, and if there are differences in lengthening behaviors between the groups.

METHODS

A prospectively collected multicenter EOS registry was queried for patients with MCGR with a minimum 2-year follow-up. Patients with rib-based proximal anchors and either spine- or pelvis-based distal anchors were included. Patients with non-MCGR, unilateral constructs, < 3 lengthenings, or missing > 25% datapoints were excluded. Patients were further divided into Primary-MCGR (pMCGR) and Secondary-MCGR (sMCGR).

RESULTS

43 rib-to-spine and 31 rib-to-pelvis MCGR patients were included. There was no difference in pre-implantation, post-implantation and pre-definitive procedure T1-T12 height, T1-S1 height, and major Cobb angles between the groups (p > 0.05). Sub-analysis was performed on 41 pMCGR and 19 sMCGR rib-to-spine patients, and 31 pMCGR and 17 sMCGR rib-to-pelvis patients. There is a decrease in rod lengthenings achieved at subsequent lengthenings for each group: rib-to-spine pMCGR (rho = 0.979, p < 0.001), rib-to-spine sMCGR (rho = 0.855, p = 0.002), rib-to-pelvis pMCGR (rho = 0.568, p = 0.027), and rib-to-pelvis sMCGR (rho = 0.817, p = 0.007). Rib-to-spine pMCGR had diminished lengthening over time for idiopathic, neuromuscular, and syndromic patients (p < 0.05), with no differences between the groups (p > 0.05). Rib-to-pelvis pMCGR neuromuscular patients had decreased lengthening over time (p = 0.01), but syndromic patients had preserved lengthening over time (p = 0.65).

CONCLUSION

Rib-to-spine and rib-to-pelvis pMCGR and sMCGR demonstrate diminished ability to lengthen over subsequent lengthenings.

Isolated main thoracic curve fusion in idiopathic scoliosis: optimizing radiographic outcomes using lumbar modifiers to guide correction

PURPOSE

Does differential correction of main thoracic curve (MTC) and instrumented LIV angulation based on lumbar modifiers affect radiographic outcomes, and can preoperative supine AP radiograph be used to guide correction for optimal final radiographic alignment.

METHODS

Retrospective analysis of idiopathic scoliosis patients who underwent selective thoracic fusions (LIV T11-L1) for Lenke 1 and 2 curve patterns, < 18 years of age. 2-year minimum follow-up. Optimal outcome meant LIV + 1 of < 5 degrees disk-wedging and C7-CSVL < 2 cm. 82 patients met inclusion criteria (70% female), mean age 14.1 years.

RESULTS

24 patients were A modifier, 21 B modifier, and 37 C modifier. There were 52 optimal and 30 suboptimal outcomes. LIV was not associated with outcome (p = 0.08). For optimal outcomes, A modifiers' MTC improved 65%, B modifiers 65%, and C modifiers 59%. C modifiers' MTC correction was less than A modifiers (p = 0.03) but equivalent to B modifiers' (p = 0.10). A modifiers' LIV + 1 tilt improved 65%, B modifiers 64%, and C modifiers 56%. C modifiers' instrumented LIV angulation was greater than A modifiers' (p < 0.01) but equivalent to B modifiers' (p = 0.06). Preoperative supine LIV + 1 tilt was 16^o in optimal outcomes and 15° in suboptimal outcomes. Instrumented LIV angulation was 9° for both. The correction between preoperative LIV + 1 tilt and instrumented LIV angulation was not significantly different between groups (p = 0.67).

CONCLUSION

Differential MTC and LIV tilt correction based on lumbar modifier may be a valid goal. Optimizing radiographic outcome by matching instrumented LIV angulation to preoperative supine LIV + 1 tilt could not be proven.

LEVEL OF EVIDENCE

IV.

Lengthening Behavior of Magnetically Controlled Growing Rods in Early-Onset Scoliosis: A Multicenter Study

BACKGROUND

The "law of diminishing returns" is described for traditional growing rods. Magnetically controlled growing rods (MCGRs) have become a preferred implant for the surgical treatment of early-onset scoliosis (EOS). We examined a large cohort of patients with EOS to determine whether the law of diminishing returns applies to MCGRs.

METHODS

A prospectively collected, multicenter registry was queried for patients with EOS treated with MCGRs. Patients with only spine-based implants and a minimum of 2 years of follow-up were included; patients with congenital scoliosis, single rods, <3 lengthenings, or >25% missing data were excluded. Patients were analyzed in 3 cohorts: primary MCGR (pMCGR) had first-time MCGR implants, secondary MCGR (sMCGR) were converted from an MCGR to a new MCGR, and conversion MCGR (cMCGR) were converted from a non-MCGR implant to MCGR.

RESULTS

A total of 189 patients in the pMCGR group, 44 in the cMCGR group, and 41 in the sMCGR group were analyzed. From post-MCGR placement to the most recent follow-up or pre-definitive procedure, there were no differences in the changes in major Cobb angle, T1-S1 height, or T1-T12 height over time between the pMCGR and cMCGR groups. There was a decrease in length achieved at subsequent lengthenings in all cohorts (p < 0.01), and the sMCGR group had a significantly poorer ability to lengthen at each subsequent lengthening versus the pMCGR and cMCGR groups (p < 0.02). The 1-year survival rate was 90.5% for pMCGR, 84.1% for sMCGR, and 76.4% for cMCGR; 2-year survival was 61.5%, 54.4%, and 41.4%, respectively; and 3-year survival was 37.6%, 36.7%, and 26.9%, respectively. Excluding MCGRs still expanding, 27.6% of pMCGRs, 8.8% of sMCGRs, and 17.1% of cMCGRs reached the maximum excursion. Overall, 21.7% reached the maximum excursion. Within the pMCGR cohort, idiopathic and neuromuscular etiologies had a decline in lengthening achieved over time (p < 0.001), while syndromic EOS demonstrated a preserved ability to lengthen over time (p = 0.51). When the etiological groups were compared with each other, the neuromuscular group had the least ability to lengthen over time (p = 0.001 versus syndromic, p = 0.02 versus idiopathic).

CONCLUSIONS

The MCGR experiences the law of diminishing returns in patients with EOS. We found that only 21.7% of rods expanded to within 80% of the maximum excursion.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

The Use of Biomarkers in the Early Diagnosis of Septic Arthritis and Osteomyelitis-A Pilot Study

BACKGROUND

The diagnosis of septic arthritis (SA) and osteomyelitis (OM) has remained challenging in the pediatric population, often accompanied by delays and requiring invasive interventions. The purpose of this pilot study is to identify a novel panel of biomarkers and cytokines that can accurately differentiate SA and OM at initial presentation using serum alone.

METHODS

Twenty patients below 18 years old whose working diagnosis included SA (n=10) and OM (n=10) were identified. Serum was collected at initial evaluation. Each sample underwent seven ELISA [C1-C2, COMP, CS-846, hyaluronan, procalcitonin, PIIANP, C-terminal telopeptide of type II collagen (CTX-II)] and 65-plex cytokine panels. Principal component and Lasso regression analysis were performed to identify a limited set of predictive biomarkers.

RESULTS

Mean age was 4.7 and 9.5 years in SA and OM patients, respectively (P=0.029). 50% of SA patients presented within 24 hours of symptom onset, compared with 0% of OM patients (P=0.033). 30% of SA patients were discharged home with an incorrect diagnosis and re-presented to the emergency department days later. At time of presentation: temperature ≥38.5°C was present in 10% of SA and 40% of OM patients (P=0.12), mean erythrocyte sedimentation rate (mm/h) was 51.6 in SA and 44.9 in OM patients (P=0.63), mean C-reactive protein (mg/dL) was 55.8 in SA and 71.8 in OM patients (P=0.53), and mean white blood cells (K/mm3) was 12.5 in SA and 10.4 in OM patients (P=0.34). 90% of SA patients presented with ≤2 of the Kocher criteria. 100% of SA and 40% of OM patients underwent surgery. 70% of SA cultures were culture negative, 10% MSSA, 10% Kingella, and 10% Strep pyogenes. 40% of OM cultures were culture negative, 50% MSSA, and 10% MRSA. Four biomarkers [CTx-II, transforming growth factor alpha (TGF-α), monocyte chemoattractant protein 1 (MCP-1), B cell-attracting chemokine 1] were identified that were able to classify and differentiate 18 of the 20 SA and OM cases correctly, with 90% sensitivity and 80% specificity.

CONCLUSIONS

This pilot study identifies a panel of biomarkers that can differentiate between SA and OM at initial presentation using serum alone.

LEVEL OF EVIDENCE

Level II-diagnostic study.

The impact of segmental spinal alignment on the development of proximal junctional kyphosis after instrumented posterior spinal fusions for idiopathic scoliosis

PURPOSE

To assess if the preservation of preoperative kyphosis within the cephalad two motion segments of instrumented posterior spinal fusions (PSF), for idiopathic scoliosis (IS), would be associated with lower frequency of proximal junctional kyphosis (PJK) at 2 years postoperatively. Previous studies on PJK in IS have reported conflicting findings; none has evaluated the relationship between segmental kyphosis within the cephalad instrumented construct and PJK.

METHODS

One hundred consecutive patients undergoing PSF for IS by a single surgeon with minimum 2-year follow-up were evaluated. Radiographic evaluation focused on sagittal alignment of the upper instrumented vertebrae (UIV), the 1 and 2 vertebrae cephalad (UIV + 1, UIV + 2) and caudal (UIV - 1, UIV - 2). This was measured between the inferior endplate of the UIV and the superior endplate of the UIV + 1 and UIV + 2 or between the superior endplate of the UIV and the inferior endplate of the UIV - 1 and UIV - 2. PJK was defined as present if the final UIV + 2 ≥ 10° and final UIV + 2-preop UIV + 2 ≥ 10°.

RESULTS

There were 78 females and 22 males whose mean age was 14.6 (± 2.1) years at surgery; mean follow-up was 3.9 (2-9.3) years. The overall frequency of PJK was 25% (25/100) at final follow-up. Preoperative mean coronal curve measured 63° (40°-107°) with a mean 66% correction at final follow-up. UIV was T2 (n = 15), T3 (n = 47) or T4 (n = 38). More caudal UIVs were associated with PJK development (p = 0.04): T2 (13%), T3 (21%) and T4 (34%). Greater preoperative T5-T12 thoracic kyphosis and UIV - 2, and lower major curve apex (below T12) were more likely to develop PJK (p = 0.019, p = 0.004 and p = 0.007, respectively). Post-operatively, larger values for UIV - 1 (p ≤ 0.001) and UIV - 2 (p = 0.002) were associated with PJK at final follow-up. Longer fusion lengths (10-13 vs. 6-9 segments, p = 0.02) and the presence of thoracolumbar/lumbar structural curves (Lenke 3-6 vs. 1-2, p = 0.032) had higher rates of PJK (32% vs 10% and 37% vs 18%, respectively). Changes in UIV - 1 and UIV - 2 (preoperatively to immediately post-op) did not influence the development of PJK. At final follow-up, no patient required revision surgery for symptomatic proximal junctional kyphosis.

CONCLUSIONS

In this study, changes in UIV - 1 and UIV - 2 at surgery were not related to PJK. Greater preoperative T5-T12 thoracic kyphosis and UIV - 2, lower major curve apex (T12 and below), and greater post-operative UIV - 1 and UIV - 2 were associated with higher frequencies of PJK. Higher UIV (T2 vs. T4) and LIV levels had a protective effect against PJK. Based on this study, the preservation of segmental kyphosis within the instrumented cephalad two levels of the PSF did not minimize the occurrence of radiographic PJK.

LEVEL OF EVIDENCE

Level IV.

Magnetically Controlled Growing Rods (MCGR) Versus Single Posterior Spinal Fusion (PSF) Versus Vertebral Body Tether (VBT) in Older Early Onset Scoliosis (EOS) Patients: How Do Early Outcomes Compare?

STUDY DESIGN

Retrospective review of prospective data from multicenter registry.

OBJECTIVE

Compare outcomes of posterior spinal fusion (PSF) versus magnetically controlled growing rods (MCGR) versus vertebral body tethers (VBT) in 8- to 11-year-old idiopathic early onset scoliosis (EOS) patients.

SUMMARY OF BACKGROUND DATA

In EOS, it is unclear at what age the benefit of growth-sparing strategies outweighs increased risks of surgical complications, compared with PSF.

METHODS

One hundred thirty idiopathic EOS patients, 81% female, aged 8-11 at index surgery (mean 10.5 yrs), underwent PSF, MCGR, or VBT. Scoliosis curve, kyphosis, thoracic and spinal height, complications, and Quality of Life (QoL) were assessed preoperatively and at most recent follow-up (prior to final fusion for VBT/MCGR).

RESULTS

Of 130 patients, 28.5% received VBT, 39.2% MCGR, and 32.3% PSF. The VBT cohort included more females (P < 0.0005), was older (P < 0.0005), more skeletally mature (P < 0.0005), and had smaller major curves (P < 0.0005). At follow-up, scoliosis curve corrected 41.1 ± 22.4% in VBT, 52.2 ± 19.9% in PSF, and 27.4 ± 23.9% in MCGR (P < 0.0005), however, not all VBT/MCGR patients finished treatment. Fifteen complications occurred in 10 VBTs, 6 requiring unplanned surgeries; 45 complications occurred in 31 MCGRs, 11 requiring unplanned surgeries, and 9 complications occurred in 6 PSFs, 3 requiring unplanned revisions. Cox proportional hazards regression adjusted for age, gender, and preoperative scoliosis curve revealed that MCGR (hazard ratio [HR] = 21.0, 95% C.I. 4.8-92.5; P < 0.001) and VBT (HR = 7.1, 95% C.I. 1.4-36.4; P = 0.019) patients were at increased hazard of requiring revision, but only MCGR patients (HR = 5.6, 95% C.I. 1.1-28.4; P = 0.038) were at an increased hazard for unplanned revisions compared with PSF. Thoracic and spinal height increased in all groups. QoL improved in VBT and PSF patients, but not in MCGR patients.

CONCLUSION

In older idiopathic EOS patients, MCGR, PSF, and VBT controlled curves effectively and increased spinal height. However, VBT and PSF have a lower hazard for an unplanned revision and improved QoL.Level of Evidence: 3.

Single distraction-rod constructs in severe early-onset scoliosis: Indications and outcomes

BACKGROUND CONTEXT

Since the study of Thompson, et al in 2005, use of dual-growing rod constructs have become the gold standard for operative treatment in early-onset scoliosis. However, use of dual-growing rod constructs may not be possible, due to patient size and the type, location and severity of the spinal deformity.

PURPOSE

The purpose of this study is to: (1) describe the deformities treated with single-growing rod constructs, and (2) report the outcomes of single-growing rods since 2005.

STUDY DESIGN

Observational, descriptive case series METHODS: A prospective, multi-center, international database of early-onset scoliosis patients were queried to identify all patients with single traditional growing rods (sTGR) or magnetically-controlled growing rods (sMCGR) since the 2005. Patients were excluded if there were greater than 1 rod or if there was less than 2 years of follow-up postoperatively. Twenty-five patients (13 female, 12 male) were identified from the database query, which satisfied the inclusion and exclusion criteria.

RESULTS

Mean age at index surgery was 4.7 years (1.3 to 9.3 years) and mean follow-up was 4.3 years (2.0 to 10.6 years). Eleven patients were classified as congenital (all mixed-type), six neuromuscular, five idiopathic and three syndromic. Proximal foundations were ribs in 23 patients and pedicle screws in two patients. The distal foundations were the spine in 25 patients and three pelvic S-hooks. All single rods were on the concave side of the deformity. Interpretation of preoperative radiographs determined in 72% (18/25) of cases dual growing rods would be difficult and/or suboptimal due to patient size (longitudinal a/o weight) and/or kyphosis/kyphoscoliosis with severe rotation. Maximal coronal deformity improved 30% (83.9 degrees to 58.6 degrees) at latest follow-up. Maximal kyphosis increased 17% (45.6 degrees to 57.4 degrees). Postoperative length increase: T1-T12, 17.0 mm (4.6 mm/year); T1-S1, 34 mm (9.4 mm/year). Total secondary surgeries for TGRs were 100: 66 lengthenings, 32 revisions, two unknown. 10 MCGRs secondary surgeries occurred in nine patients (seven for maximized actuators and three for foundation migration). At latest follow-up 20 continued with lengthenings (five TGR & 15 MCGR), four underwent definitive fusions, and one completed lengthening (implants retained).

CONCLUSIONS

Treatment of severe EOS with single rods demonstrated a 30% coronal correction. T1-S1 length increased at 9.4 mm/year and T1-T12 length at 4.6 mm/year, which are comparable to published reports on dual MCGRs. Single TGRs and MCGRs in EOS can provide acceptable short-term outcomes when dual rods are not deemed appropriate.

CLINICAL SIGNIFICANCE

The use of single growing rod constructs, in the 4-8 years old patient with EOS, can achieve reasonable short-term radiographic outcomes.

Ogden Type I to III tibial tubercle fractures in skeletally immature patients: is routine anterior compartment fasciotomy of the leg indicated?

PURPOSE

Determine the frequency of compartment syndrome of the leg after displaced, operatively treated modified Ogden I to III tibial tubercle fractures (TTFxs), evaluate the preoperative assessment and use of advanced imaging, and need for prophylactic fasciotomies.

METHODS

Retrospective analysis of operatively treated, displaced modified Ogden I to III TTFxs, at our level 1 paediatric trauma centre between 2007 and 2019. Modified Ogden Type IV and V fracture patterns were excluded. Fracture patterns were determined by plain radiographs.

RESULTS

There were 49 modified Ogden I to III TTFxs in 48 patients. None had signs nor symptoms of vascular compromise, compartment syndromes or impending compartment syndromes preoperatively. In all, 13 of the 49 fractures underwent anterior compartment fasciotomy at surgery; eight of the 13 had traumatic fascial disruptions, which were extended surgically. All incisions were primarily closed. There were no instances of postoperative compartment syndromes, growth arrest, leg-length discrepancy or recurvatum deformity postoperatively. All patients achieved radiographic union and achieved full range of movement.

CONCLUSION

The potentially devastating complications of compartment syndrome or vascular compromise following TTFx did not occur in this consecutive series of patients over 12 years. The presence of an intact posterior proximal tibial physis and posterior metaphyseal cortex (Modified Ogden TTFx Type I to III) may mitigate the occurrence of vascular injury and compartment syndrome. Plain radiographs appear appropriate as the primary method of imaging TTFxs, with use of advanced imaging as the clinical scenario dictates. Routine, prophylactic fasciotomies do not appear necessary in Ogden I to III TTFxs, but should be performed for signs and symptoms of compartment syndrome.

LEVEL OF EVIDENCE

Level IV.

Pilot Study Analysis of Serum Cytokines to Differentiate Pediatric Septic Arthritis and Transient Synovitis

BACKGROUND

In pediatric patients, the presentation of the nontraumatic acutely painful joint/limb poses a diagnostic dilemma due to the similarity of presentations of the most likely diagnoses [septic arthritis (SA), transient synovitis (TS), osteomyelitis]. Current tools employed to differentiate these diagnoses rely on nonspecific inflammatory markers, radiologic imaging, and arthrocentesis. Diagnostic algorithms utilizing these clinical, radiographic, and biochemical parameters have produced conflicting results. The purpose of this study was to identify a serum-based inflammatory signature which can differentiate SA from TS in pediatric patients.

METHODS

Serum samples were collected from 22 pediatric patients presenting with joint/extremity pain whose working diagnosis included SA or TS. Each sample was analyzed for serum abundance of 72 distinct biomarkers and cytokines using enzyme linked immunosorbent assay based arrays. Linear discriminant analysis was performed to identify a combinatorial biomarker panel to predict a diagnosis of SA or TS. Efficacy of the biomarker panel was compared with definitive diagnoses as based on laboratory tests, arthrocentesis results, and clinical scenario.

RESULTS

At the time of presentation: (1) mean erythrocyte sedimentation rate in the SA group was 56.6 mm/h and 12.4 mm/h in the TS group (P<0.001), (2) mean C-reactive protein was 55.9 mg/dL in the SA group and 13.7 mg/dL in the TS group (P=0.12), and (3) mean white blood cell was 10.9 k/mm3 in the SA group and 11.0 k/mm3 in the TS group (P=0.95). A combined panel of 72 biomarkers was examined using discriminant analysis to identify a limited set of predictors which could accurately predict whether a patient was diagnosed with SA or TS. A diagnostic algorithm consisting of transforming growth factor alpha, interleukin (IL)-7, IL-33, and IL-28A serum concentration correctly classified 20 of the 22 cases with a sensitivity and specificity of 90.9% (95% confidence interval: 73.9%-100.0%).

CONCLUSION

This study identifies a novel serum-based 4-cytokine panel that accurately differentiates SA from TS in pediatric patients with joint/limb pain.

LEVEL OF EVIDENCE

Level II-diagnostic study.

Utility of preoperative labs in posterior spinal fusions for idiopathic scoliosis

PURPOSE

Review of 216 consecutive idiopathic scoliosis (IS) patients undergoing posterior spinal fusion (PSF) demonstrated 94.9% having abnormal lab values, but only 3.9% were referred for further evaluation. A limited set of preoperative laboratory testing costing $234/patient, and thorough, adjunct review of patient/family history could identify potentially significant comorbidities preoperatively in this study. A savings of $1556/patient from current laboratory testing was identified.

METHODS

The laboratory tests routinely obtained preoperatively were investigated: abnormal preoperative laboratory outcomes were identified and further documented if additional action was taken defined as a referral to another medical provider, performance of additional lab testing or counseling, or if there was alteration of the surgical plan.

RESULTS

Overall, 94.9% (n = 205) of patients had one or more abnormal pre-operative lab values. Further actions occurred in 11.7% (n = 24) of all abnormal lab values with 3.9% (n = 8) of these being referred to other healthcare providers. Sixteen abnormal lab values underwent further testing or treatment: 11 nicotine tests, two UCx, one UA, one PT/PTT, and one bovine gelatin RAST. Eight abnormal tests prompted referral to another provider: three CBC, three platelet function tests, one UCx, and one UA. Based on these data, standard preoperative Hgb/Hct, platelet function tests, and bovine RAST (If the surgical plan involves use of bovine gelatin products) appear to be adequate to identify potential significant comorbidities in IS patients undergoing PSF for only $234/patient, a cost savings of $1556/patient from current protocol.

CONCLUSION

Based on this study of 216 patients, a limited preoperative laboratory testing and thorough, adjunct review of patient/family history appears to be adequate to identify potential comorbidities preoperatively in this study.

LEVEL OF EVIDENCE

II.

Comparing health-related quality of life and burden of care between early-onset scoliosis patients treated with magnetically controlled growing rods and traditional growing rods: a multicenter study

STUDY DESIGN

Multicenter retrospective cohort study.

OBJECTIVES

To compare pre-operative and post-operative EOSQ-24 scores in magnetically controlled growing rods (MCGR) and traditional growing rod (TGR) patients. Since the introduction of MCGR, early-onset scoliosis patients have been afforded a reduction in the number of surgeries compared to the TGR technique. However, little is known about (health-related quality of life) and burden of care outcomes between these surgical techniques.

METHODS

This is a retrospective cohort study using a multicenter registry on patients with EOS undergoing MCGR or TGR between 2008 and 2017. The EOSQ-24 was administered at preoperative and postoperative 2-year assessments. The EOSQ-24 scores were compared between MCGR and TGR as well as preoperatively and postoperatively within each procedure.

RESULTS

110 patients were analyzed in this study (TGR, N = 32; MCGR, N = 78). There were no significant differences in preoperative age, gender, etiology, main coronal curve or maximum kyphosis between TGR and MCGR groups. Patients with TGR had averaged 3.9 surgical lengthenings and MCGR had averaged 7.7 non-invasive lengthenings by the 2-year follow-up. When changes in preoperative to postoperative scores were compared, MCGR had more improvements in pain, emotion, child satisfaction and parent satisfaction than TGR although there were no statistical significance. When analyzed separately, MCGR cohort had improvement in scores for all four domains and four sub-domains; while, TGR cohort only had improvement in financial burden domain and pulmonary function sub-domain.

CONCLUSION

Although there was no statistical significance, the improvement in pain, emotion and satisfaction scores was larger in MCGR than TGR. Since these areas can be influenced more by mental well-being than other sub-domains, the results may prove our hypothesis that compared to TGR, MCGR with reduced number of surgeries have better psychosocial effects.

LEVEL OF EVIDENCE

III.

Treatment of femoral fractures in children aged two to six

Aims

Current American Academy of Orthopaedic Surgeons (AAOS) guidelines for treating femoral fractures in children aged two to six years recommend early spica casting although some individuals have recommended intramedullary stabilization in this age group. The purpose of this study was to compare the treatment and family burden of care of spica casting and flexible intramedullary nailing in this age group.

Methods

Patients aged two to six years old with acute, non-pathological femur fractures were prospectively enrolled at one of three tertiary children’s hospitals. Either early closed reduction with spica cast application or flexible intramedullary nailing was accomplished under general anaesthesia. The treatment method was selected after discussion of the options by the surgeon with the family. Data were prospectively collected on patient demographics, fracture characteristics, complications, pain medication, and union. The Impact on Family Scale was obtained at the six-week follow-up visit. In all, 75 patients were included in the study: 39 in the spica group and 36 in the nailing group. The mean age of the spica group was 2.71 (2.0 to 6.9) years and the mean age of the nailing group was 3.16 (2.0 to 6.9) years.

Results

All fractures healed without evidence of malunion or more than 2.0 cm of shortening. The mean Impact on Family score was 70.2 for the spica group and 63.2 (55 to 99) for the nailing group, a statistically significant difference (p = 0.024) in a univariate analysis suggesting less impairment of the family in the intramedullary nailing group. There was no significant difference between pain medication requirements in the first 24 hours postoperatively. Two patients in the spica group and one patient in the intramedullary nailing group required additional treatment under anaesthesia.

Conclusion

Both early spica casting and intramedullary nailing were effective methods for treating femoral fractures in children two to six years of age. Intramedullary stabilization provides an option in this age group that may be advantageous in some social situations that depend on the child’s mobility. Fracture treatment should be individualized based on factors that extend beyond anatomical and biological factors. Cite this article: Bone Joint J 2020;102-B(8):1056–1061.

The value of preoperative labs in identifying "at-risk" patients for developing surgical site infections after pediatric neuromuscular spine deformity surgery

STUDY DESIGN

This is a retrospective cohort study via a single surgeon, two-hospital database.

OBJECTIVE

PSF in NMS patients is a high-risk surgery, with rates of SSI up to 24%. There is conflicting evidence in the literature regarding a possible association between low preoperative nutritional lab values and heightened risk of SSI after PSF. A retrospective analysis of a 20-year cohort of 111 pediatric neuromuscular scoliosis (NMS) patients that underwent posterior spinal fusion (PSF) with instrumentation was performed. Overall, seven patients (6.3%) developed a postoperative surgical site infection (SSI). With the possible exception of transferrin, low preoperative lab values (prealbumin, Hgb/Hct, WBC, TLC, total protein, albumin) were not associated with SSI. These findings question the utility of the current methodology of preoperative laboratory evaluation in identifying patients at elevated risk for SSI following PSF.

METHODS

A single-surgeon, two-hospital database was reviewed to identify all patients who underwent PSF for NMS. Diagnoses included cerebral palsy (n = 82), myelomeningocele (n = 13), spinal muscular atrophy (n = 4), and other (n = 12). Medical records for 117 patients were examined; 6 were excluded due to missing lab values. SSI was defined as an infection necessitating a return to the operating room for irrigation and debridement of the surgical site. Demographic information, preoperative lab values, spinal deformity magnitude, and surgical procedure data were recorded.

RESULTS

There were 50 males and 61 females with a mean age of 14 years and 2.5 months (8-20 years). Seven patients (6.3%) experienced postoperative SSI. SSI rate for PSF to pelvis was 7.7% vs. PSF to lumbar spine, 3.0% (NS; p = 0.672). Length of PSF was not statistically associated with SSI (p = 0.172). SSI due to gram positives and polymicrobial gram negatives occurred with equal incidence. Preoperative lab values of transferrin, prealbumin, albumin, WBC count, total lymphocyte count, and total protein were not associated with SSI. Patients with postoperative SSI had higher mean Hct compared to controls (p = 0.041). While 40.6% of controls had low Hgb (< 13.8 g/dl), all patients who developed SSI had Hgb within the normal range (p = 0.043). Similarly, while 37.6% of controls had low Hct (< 40.7%), all patients who developed SSI had Hct within the normal range (p = 0.05).

CONCLUSION

Low preoperative nutritional labs, Hgb/Hct, and TLC values were not found to be associated with an increased incidence of SSI in this analysis. These findings question the utility of preoperative lab values in identifying "at-risk" populations for SSI after PSF for NMS.

LEVEL OF EVIDENCE

IV Therapeutic.

Normative Data of Pulmonary Function Tests and Radiographic Measures of Chest Development in Children Without Spinal Deformity: Is a T1-T12 Height of 22 cm Adequate?

STUDY DESIGN

Retrospective case series.

OBJECTIVES

To develop normative data of pulmonary function tests (PFTs) and radiographic measures of chest development in normal children and to determine if the prior proposed T1-T12 height of 22 cm for spinal fusion in a growing child is adequate for pulmonary function based on normative PFT values at skeletal maturity.

SUMMARY OF BACKGROUND DATA

Shortening of the spine from T1-T12 is a concern with early thoracic fusion for spinal deformity, as it has a deleterious effect on the development of the pulmonary system.

METHODS

Children with mild asthma who had pulmonary function tests (PFTs) >90% and without chest or spinal deformity were identified. PFT data included absolute forced vital capacity (FVC), %-predicted FVC, absolute forced expiratory volume in one second (FEV1), %-predicted FEV1, and FEV1/FVC. Radiographic measurements performed on chest radiographs included T1-T12 height, coronal chest width (CCW), and space available for the lung (SAL) bilaterally. These data were analyzed for all patients and for patients with T1-T12 heights 22-24 cm. To assess the impact of T1-T12 shortening on PFTs at skeletal maturity, spirometric standards for healthy adult lifetime nonsmokers were used.

RESULTS

Of 1,797 PFT studies, 149 children (average age 12.4 ± 3.0 years; girls, 97) were analyzed. For the entire cohort, PFT values were as follows: FVC 3.0 ± 0.9 L, %-predicted FVC 103.9% ± 10.6%, absolute FEV1 2.7 ± 0.9 L, %-predicted FEV1 106.9% ± 11.1%, and FEV1/FVC 90.7% ± 2.6%. The averages for T1-T12 height was 25.6 ± 3.8 cm, CCW 25.5 ± 3.4 cm, and SAL bilaterally 19.0 ± 3.5 cm. For the 21 patients (girls 11; average age 9.7 ± 1.4 years) with T1-T12 heights 22-24 cm, absolute FVC was 2.2 ± 0.3 L, %-predicted FVC was 104.0% ± 13.0%, absolute FEV1 was 2.0 ± 0.3 L, %-predicted FEV1 was 108.2% ± 15.0%, and FEV1/FVC was 91.0% ± 2.7%. If these kids with 22-24 cm T1-T12 heights maintained the same thoracic height, they were calculated to have %-predicted FVC of 44% (girl) and 42% (boy) and %-predicted FEV1 of 42% (girl) and 43% (boy) at skeletal maturity (15 years old).

CONCLUSIONS

Percent-predicted FEV1 and FVC values for normal children with a T1-T12 height of 22 cm at skeletal maturity were <50%. Though this analysis does not take into consideration radial expansion of the chest or children with scoliosis (idiopathic, congenital, neuromuscular), these values are concerning and may not be adequate to guarantee that children with early-onset scoliosis who are fused with T1-T12 heights of 22 cm will have an asymptomatic pulmonary status in adulthood.

LEVEL OF EVIDENCE

Level IV.

Nasal Swab Screening for Staphylococcus aureus in Spinal Deformity Patients Treated With Growing Rods

BACKGROUND

Surgical-site infections are one of the most concerning complications in patients treated with growing rods (GR). The purpose of this study was to evaluate the use of preoperative screening for Staphylococcus aureus (SA) for all growing spine procedures, and if this would permit alteration of prophylactic antibiotics to cover the identified resistances.

METHODS

All patients were identified who had SA screening during the course of GR treatment. In otal, 34 patients [23 neuromuscular (NMS), 4 congenital, 4 idiopathic scoliosis (IS), and 3 syndromic] were identified who had 111 preoperative screenings [79 lengthenings, 23 insertions, 6 revisions, and 3 conversions to posterior spinal fusions (PSF)]. Mean age at GR insertion was 5.5 years (2 to 11 y).

RESULTS

There were 11 methicillin-resistant Staphylococcus aureus (MRSA) "+" screenings in 6 patients (5 NMS, 1 IS): 3 in 3 patients before GR insertion and 8 in 3 patients (all 3 were negative at GR insertion screening) at subsequent surgeries. There were 23 methicillin-sensitive Staphylococcus aureus (MSSA) "+" screenings in 12 patients (7 NMS, 2 congenital, 2 IS, 1 syndromic): 2 in 2 patients before GR insertion and 21 in 10 patients at subsequent surgeries (18 lengthenings, 3 revisions). Overall, 13 patients (3 MRSA+10 MSSA) were initially negative but screened positive for the first time at a subsequent surgery (12 lengthenings, 1 GR to PSF). All patients (n=5) with positive screenings before GR insertion were in patients with NMS (3 MRSA, 2 MSSA). On the basis of sensitivities, 9 patients demonstrated SA resistance to cefazolin (8 MRSA and 1 MSSA) and 6 to clindamycin (5 MRSA and 1 MSSA). Hence, if cefazolin was routinely used for all patients 26.5% of patients (9/34) would have been inadequately covered at some point during their GR treatment; clindamycin, 17.7% (6/34).

CONCLUSION

The use of SA nasal swab screening in GR patients identified 9 patients (26.5%) whose prophylactic antibiotics (cefazolin) could be altered to permit appropriate SA coverage.

LEVEL OF EVIDENCE

Level IV-retrospective case series.

Outcomes of Primary and Conversion Magnetically Controlled Growth Rods Are Different at Two-Year Follow-up: Results of North American Release

STUDY DESIGN

Multicenter retrospective review.

OBJECTIVES

To compare the radiographic outcomes and complication rates in patients with primary and conversion magnetically controlled growing rod (MCGR) implants at one and two years after surgery.

SUMMARY OF BACKGROUND DATA

Many initial early-onset scoliosis (MCGR) implantations in the United States were conversions from other types of growth-friendly systems, and the outcome similarities and differences between primary and conversion MCGR implantation procedures are still relatively unknown.

METHODS

Multicenter retrospective review of EOS patients from two multicenter EOS registries identified consecutive EOS patients treated from 2014 to 2017 with a minimum of one-year follow-up. In addition, a subset of these patients who had two-year follow-up were further analyzed.

RESULTS

In total, 383 MCGR patients were identified, of which 272 (71%) were primary (P) and 111 (29%) were conversion (C). Group P patients had significantly greater coronal curves at the time of MCGR implantation and greater initial coronal correction. There was no statistically significant difference in Cobb correction at one year or between follow-up at one and two years. The preimplantation thoracic spine height was identical in both groups, with statistically greater improvement at initial implantation in P than in C patients. Significantly greater height gains were seen in P than in C patients in the one-year follow-up cohort. There was a higher rate of complications in the C group than in the P group; however, the difference was not statistically significant. Overall, most complications were implant-related. No loss of curve correction occurred in either group.

CONCLUSIONS

Patients with primary MCGR insertion can be expected to have greater radiographic correction and spine length gain than those with conversion from growth-friendly instrumentation to MCGR, most likely because of increased spine stiffness in conversion patients. The rate of complications, primarily implant-related, remains higher in conversion than in primary insertion patients.

LEVEL OF EVIDENCE

Level III.

Complications of Posterior Column Osteotomies in the Pediatric Spinal Deformity Patient

BACKGROUND

In spinal deformity surgery, posterior column osteotomies (PCOs) are used to increase spinal flexibility and permit greater deformity correction, while avoiding the morbidity of anterior column surgery. Complications related to use of PCOs have been well characterized in adults; however, there is a paucity of information in the pediatric population.

METHODS

A single-surgeon retrospective analysis was completed of 484 PCOs in 142 patients (average age: 14.5 years) undergoing spinal deformity surgery. All surgeries were completed by a standard posterior approach using a midline incision and dual-rod, pedicle screw constructs. PCO-related complications were recorded (intraoperative monitoring alerts, postoperative neurologic deficit, dural tear/violations, cerebrospinal fluid [CSF] leak, pseudarthrosis, etc.) and analyzed by diagnosis (idiopathic, congenital, neuromuscular, syndromic).

RESULTS

The diagnoses for the 142 patients were idiopathic (103 patients), neuromuscular (23 patients), syndromic (14 patients), and congenital (2 patients). In a subset of 87 patients with 2-year radiographic follow-up, the preoperative major coronal Cobb measurement was 75.5° ± 17.6°, which corrected to 34.9° ± 17.5° postoperatively and 37.8° ± 17.9° at last follow-up (p < .0001, p < .0001). Complications evaluated were postoperative neurologic deficit (0% of patients, 0/142), dural tears/violations at site of PCO (0.4% of PCOs, 2/484), CSF leak (0% of patients, 0/142), and pseudoarthrosis at site of PCO (0% of PCOs, 0/290).

CONCLUSION

The overall frequency of complications related to PCOs was 0.4% (0.4% dural tears/violations) with 0% postoperative neurologic deficit, CSF leak, or pseudarthrosis. Based on these data, PCOs appear to be a safe technique in pediatric spine deformity surgery, with a low rate of technique-related complications.

STUDY DESIGN

Retrospective case series.

OBJECTIVES

To report the frequency of posterior column osteotomy complications (neurologic deficit, dural tear, cerebrospinal fluid leak, and pseudarthrosis) in pediatric patients undergoing spinal deformity surgery.

LEVEL OF EVIDENCE

Level IV.

Preoperative Variables Associated With Respiratory Complications After Pediatric Neuromuscular Spine Deformity Surgery

OBJECTIVE

The objective of this study is to identify preoperative laboratory values and patient factors that are associated with postoperative respiratory complications in pediatric neuromuscular scoliosis (NMS) populations undergoing posterior spinal fusion (PSF) with instrumentation.

SUMMARY OF BACKGROUND DATA

PSF in NMS patients are high-risk surgeries. Respiratory complications are the most common postoperative event, with rates up to 28.2% following surgery.

METHODS

A single-surgeon, two-hospital pediatric spine surgery database was reviewed to identify all patients who underwent PSF for NMS. Diagnoses included cerebral palsy (n=83), myelomeningocele (n=13), spinal muscular atrophy (n=4), and other (n=11). This study defined respiratory complications as postoperative pneumonia, pleural effusion, pneumothorax, need for reintubation, respiratory status requiring a return to the pediatric intensive care unit (PICU), or prolonged (>4-day) need for mechanical ventilation. Preoperative laboratory values for transferrin, prealbumin, hemoglobin/hematocrit, total protein, albumin, and total lymphocyte count were collected.

RESULTS

There were 50 males and 61 females with a mean age of 14 years 2.5 months (8-20 years). Seventeen patients (15.3%) experienced postoperative respiratory complications. On univariate analysis, any history of pneumonia, the presence of gastrostomy tube, and low transferrin levels were associated with postoperative respiratory complications, and a strong trend (p=.06) was observed for tracheostomy. On multivariate analysis, the presence of gastrostomy tube and history of pneumonia remained as clinically significant predictors of postoperative respiratory complications.

CONCLUSION

Pediatric NMS patients undergoing PSF that have history of pneumonia or gastrostomy tube present at time of surgery are at increased risk for postoperative respiratory complications. The univariate associations of tracheostomy presence and low transferrin levels with postoperative respiratory complications deserve further examination.

LEVEL OF EVIDENCE

Level II.

Cost analysis of a growth guidance system compared with traditional and magnetically controlled growing rods for early-onset scoliosis: a US-based integrated health care delivery system perspective

Purpose

Treating early-onset scoliosis (EOS) with traditional growing rods (TGR) is effective but requires periodic surgical lengthening, risking complications. Alternatives include magnetically controlled growing rods (MCGR) that lengthen noninvasively and the growth guidance system (GGS), which obviate the need for active, distractive lengthenings. Previous studies have reported promising clinical effectiveness for GGS; however the direct medical costs of GGS compared to TGR and MCGR have not yet been explored.

Methods

To estimate the cost of GGS compared with MCGR and TGR for EOS an economic model was developed from the perspective of a US integrated health care delivery system. Using dual-rod constructs, the model estimated the cumulative costs associated with initial implantation, rod lengthenings (TGR, MCGR), revisions due to device failure, surgical-site infections, device exchange, and final spinal fusion over a 6-year episode of care. Model parameters were from peer-reviewed, published literature. Medicare payments were used as a proxy for provider costs. Costs (2016 US$) were discounted 3% annually.

Results

Over a 6-year episode of care, GGS was associated with fewer invasive surgeries per patient than TGR (GGS: 3.4; TGR: 14.4) and lower cumulative costs than MCGR and TGR, saving $25,226 vs TGR. Sensitivity analyses showed that results were sensitive to changes in construct costs, rod breakage rates, months between lengthenings, and TGR lengthening setting of care.

Conclusion

Within the model, GGS resulted in fewer invasive surgeries and deep surgical site infections than TGR, and lower cumulative costs per patient than both MCGR and TGR, over a 6-year episode of care. The analysis did not account for family disruption, pain, psychological distress, or compromised health-related quality of life associated with invasive TGR lengthenings, nor for potential patient anxiety surrounding the frequent MCGR lengthenings. Further analyses focusing strictly on current generation technologies should be considered for future research.

Radiographic Outcomes of Shilla Growth Guidance System and Traditional Growing Rods Through Definitive Treatment

STUDY DESIGN

Retrospective review of a multicenter database.

OBJECTIVES

To compare the radiographic outcomes of patients who had undergone the Shilla Growth Guidance System (SGGS) and traditional growing rod (GR) treatment for management of early-onset scoliosis (EOS) through definitive treatment.

SUMMARY OF BACKGROUND DATA

The efficacy of surgical treatment of EOS can only be determined after definitive treatment has been completed. We wanted to review our experience with the SGGS and GR for management of EOS through definitive treatment.

METHODS

Patients who had surgical treatment with SGGS or GR and had undergone definitive treatment were included. The patients were matched by age, preoperative curve magnitude, and diagnosis. The study population consisted of 36 patients (18 in each group) whose mean age at initial surgery was as follows: SGGS, 7.9 years; and GR, 7.7 years (not significant [NS]). Length of follow-up after initial surgery was 6.1 years for SGGS and 7.4 years for GR (NS). Definitive treatment was posterior spinal fusion (15 SGGS, 17 GR), implant removal (3 SGGS), or completion of lengthenings (1 GR).

RESULTS

The preoperative curve was 61 degrees for SGGS and 65 degrees for GR (NS). After index surgery, the major curve decreased to 24 degrees (-37 degrees) for SGGS and 38 (-27 degrees) for GR (p < .05). At last follow-up, the major curve was 34 degrees (44%) for SGGS and 36 degrees (45%) for GR (NS). The initial T1-T12 length for SGGS was 188 mm and for GR, 181 mm; at last follow-up, SGGS was 234 mm (46 mm increase) and GR was 233 mm (52 mm increase) (NS).

CONCLUSION

Our analysis shows the final radiographic outcomes (and changes) and complications (implant-related and infection) between the SGGS and GR groups were not statistically different. The main difference between the two groups was the threefold difference in overall surgeries.

Failure of Intraoperative Monitoring to Detect Postoperative Neurologic Deficits: A 25-year Experience in 12,375 Spinal Surgeries

STUDY DESIGN

Retrospective.

OBJECTIVE

The purpose was to categorize and evaluate intraoperative monitoring (IOM) failure to detect neurologic deficits occurring during spinal surgery.

SUMMARY OF BACKGROUND DATA

The efficacy of spinal cord/nerve root monitoring regarding undetected neurologic deficits is examined in a large, single institution series involving all levels of the spinal column and all spinal surgical procedures.

METHODS

Multimodality IOM included somatosensory-evoked potentials (SSEPs), descending neurogenic-evoked potentials (DNEPs), transcranial motor-evoked potentials (MEPs), dermatomal somatosensory-evoked potentials (DSEPs), and spontaneous and triggered electromyography (spEMG, trgEMG). We reviewed 12,375 patients who underwent surgery for spinal pathology from 1985 to 2010. There were 7178 females (59.3%) and 5197 males (40.7%); 9633 (77.8%) primary surgeries and 2742 (22.2%) revisions. Procedures by spinal level were cervical 29.7% (3671), thoracic/thoracolumbar 45.4% (5624), and lumbosacral 24.9% (3080). Age at surgery was > 18 years - 72.7% (8993) and < 18 years - 27.3% (3382).

RESULTS

Forty-five of the 12,375 patients (0.36%) had false negative outcomes. False negative results by modality were as follows: spEMG (n = 22, 48.8%), trgEMG (n = 8, 17.7%), DSEP (n = 4, 8.8%), DNEP (n = 4, 8.8%), SSEP (n = 3, 6.6%), DSEP/spEMG (n = 3, 6.6%), and trgEMG/spEMG (n = 1, 2.2%). Thirty-seven patients had immediate postoperative deficits unidentified by IOM; 30 patients (81%) involved nerve root monitoring, four patients had spinal cord deficits, and three patients had peripheral sensory deficits. Eight patients had permanent neurologic deficits, six (0.048%) were nerve root and two (0.016%) were spinal cord in nature.

CONCLUSION

Despite correct application and usage, IOM data failed to identify 45 (0.36%) patients with false negative outcomes out of 12,375 surgical patients. Eight patients (0.064%) of these 45 patients had permanent neurologic deficits, six patients had nerve root deficits in nature and two patients had spinal cord deficits. Although admittedly small, this represents the risk of undetected neurologic deficits even when properly using IOM. Deficits are at a higher risk to remain unresolved when not detected by IOM.

LEVEL OF EVIDENCE

4.

Preoperative MRSA Screening in Pediatric Spine Surgery: A Helpful Tool or a Waste of Time and Money?

OBJECTIVES

To review the use of preoperative screening for Staphylococcus aureus for all pediatric spine procedures that was instituted at our facility in a multimodal approach to decrease the frequency of postoperative wound infections.

SUMMARY OF BACKGROUND DATA

Four years ago at our facility, a multimodal approach to decrease the frequency of postoperative infections after pediatric spine surgery was instituted.

METHODS

A single-center, single-surgeon pediatric spine surgery database was queried to identify all patients who had preoperative S. aureus nasal swab screening. Data collected included demographic data, diagnoses, methicillin-resistant S. aureus (MRSA) swab findings, bacterial antibiotic sensitivities, and outcome of the spine surgery.

RESULTS

A total of 339 MRSA screenings were performed. Twenty (5.9%) were MRSA positive, and 55 (16.2%) were methicillin-sensitive S. aureus (MSSA) positive. In the MRSA-positive group, 13 were neuromuscular, 5 were adolescent idiopathic scoliosis (AIS), 1 congenital, and 1 infantile idiopathic scoliosis. Of the MRSA-positive screenings, 13 (65.0% of MRSA-positive screenings; 3.8% of entire cohort) of were newly identified cases (9 neuromuscular, 3 AIS, and 1 congenital diagnoses). In the 55 MSSA-positive, 6 documented resistance to either cefazolin or clindamycin. Hence, in up to 22 of the preoperative screenings (6.5% of entire cohort; 16 MRSA and 6 MSSA showed antibiotic resistance), the preoperative antibiotic regimen could be altered to appropriately cover the identified bacterial resistances. During the study period, there were 11 patients who were diagnosed with a postoperative deep wound infection, none of them having positive screenings.

CONCLUSION

The use of preoperative nasal swab MRSA screening permitted adjustment of the preoperative antibiotic regimen in up to 6.5% of patients undergoing pediatric spine surgery. This inexpensive, noninvasive tool can be used in preoperative surgical planning for all patients undergoing spinal procedures.

LEVEL OF EVIDENCE

Level IV.

Genetic Risk for Aortic Aneurysm in Adolescent Idiopathic Scoliosis

BACKGROUND

Scoliosis is a feature of several genetic disorders that are also associated with aortic aneurysm, including Marfan syndrome, Loeys-Dietz syndrome, and type-IV Ehlers-Danlos syndrome. Life-threatening complications of aortic aneurysm can be decreased through early diagnosis. Genetic screening for mutations in populations at risk, such as patients with adolescent idiopathic scoliosis, may improve recognition of these disorders.

METHODS

The coding regions of five clinically actionable genes associated with scoliosis (COL3A1, FBN1, TGFBR1, TGFBR2, and SMAD3) and aortic aneurysm were sequenced in 343 adolescent idiopathic scoliosis cases. Gene variants that had minor allele frequencies of <0.0001 or were present in human disease mutation databases were identified. Variants were classified as pathogenic, likely pathogenic, or variants of unknown significance.

RESULTS

Pathogenic or likely pathogenic mutations were identified in 0.9% (three) of 343 adolescent idiopathic scoliosis cases. Two patients had pathogenic SMAD3 nonsense mutations consistent with type-III Loeys-Dietz syndrome and one patient had a pathogenic FBN1 mutation with subsequent confirmation of Marfan syndrome. Variants of unknown significance in COL3A1 and FBN1 were identified in 5.0% (seventeen) of 343 adolescent idiopathic scoliosis cases. Six FBN1 variants were previously reported in patients with Marfan syndrome, yet were considered variants of unknown significance based on the level of evidence. Variants of unknown significance occurred most frequently in FBN1 and were associated with greater curve severity, systemic features of Marfan syndrome, and joint hypermobility.

CONCLUSIONS

Clinically actionable pathogenic mutations in genes associated with adolescent idiopathic scoliosis and aortic aneurysm are rare in patients with adolescent idiopathic scoliosis who are not suspected of having these disorders, although variants of unknown significance are relatively common.

CLINICAL RELEVANCE

Routine genetic screening of all patients with adolescent idiopathic scoliosis for mutations in clinically actionable aortic aneurysm disease genes is not recommended on the basis of the high frequency of variants of unknown significance. Clinical evaluation and family history should heighten indications for genetic referral and testing.

Spinal Cord Monitoring Data in Pediatric Spinal Deformity Patients With Spinal Cord Pathology

STUDY DESIGN

Retrospective.

OBJECTIVES

The purpose of this study is to review the efficacy of monitoring data and outcomes in pediatric patients with spinal cord pathology.

SUMMARY OF BACKGROUND DATA

The incidence of spinal cord pathology in pediatric patients with scoliosis has been reported between 3% and 20%. Previous studies demonstrated that intraoperative spinal cord monitoring (IOM) during scoliosis surgery can be reliable despite underlying pathology.

METHODS

A single-center retrospective review of 119 spinal surgery procedures in 82 patients with spinal cord pathology was performed. Diagnoses included Arnold-Chiari malformation, syringomyelia, myelomeningocele, spinal cord tumor, tethered cord, and diastematomyelia. Baseline neurologic function and history of prior neurosurgical intervention were identified. Outcome measures included ability to obtain reliable monitoring data during surgery and presence of postoperative neurologic deficits. Results were compared for 82 patients with adolescent idiopathic scoliosis (AIS).

RESULTS

Usable IOM data were obtained in 82% of cases (97/119). Twenty-two cases (18%) had no lower extremity data. Patients with Arnold-Chiari malformation or syringomyelia pathologies, in isolation or together, had a significantly higher rate of reliable data compared to other pathologies (p < .0001). Among study group cases with usable data, there were 1 false negative (1%) and 4 true positive (4%) outcomes. There were no permanent neurologic deficits. The spinal cord pathology group demonstrated 80% sensitivity and 92% specificity.

CONCLUSIONS

Spinal cord monitoring is a valuable tool in pediatric patients with spinal cord pathology undergoing spinal deformity surgeries. When obtained, data allow to detect changes in spinal cord function. Patients with a diagnosis of Arnold-Chiari or syringomyelia have monitoring data similar to those patients with AIS. Patients with other spinal cord pathologies have less reliable data, and surgeons should have a lower threshold for performing wake-up tests to assess spinal cord function intraoperatively.

Tapping insertional torque allows prediction for better pedicle screw fixation and optimal screw size selection

BACKGROUND CONTEXT

There is currently no reliable technique for intraoperative assessment of pedicle screw fixation strength and optimal screw size. Several studies have evaluated pedicle screw insertional torque (IT) and its direct correlation with pullout strength. However, there is limited clinical application with pedicle screw IT as it must be measured during screw placement and rarely causes the spine surgeon to change screw size. To date, no study has evaluated tapping IT, which precedes screw insertion, and its ability to predict pedicle screw pullout strength.

PURPOSE

The objective of this study was to investigate tapping IT and its ability to predict pedicle screw pullout strength and optimal screw size.

STUDY DESIGN

In vitro human cadaveric biomechanical analysis.

METHODS

Twenty fresh-frozen human cadaveric thoracic vertebral levels were prepared and dual-energy radiographic absorptiometry scanned for bone mineral density (BMD). All specimens were osteoporotic with a mean BMD of 0.60 ± 0.07 g/cm(2). Five specimens (n=10) were used to perform a pilot study, as there were no previously established values for optimal tapping IT. Each pedicle during the pilot study was measured using a digital caliper as well as computed tomography measurements, and the optimal screw size was determined to be equal to or the first size smaller than the pedicle diameter. The optimal tap size was then selected as the tap diameter 1 mm smaller than the optimal screw size. During optimal tap size insertion, all peak tapping IT values were found to be between 2 in-lbs and 3 in-lbs. Therefore, the threshold tapping IT value for optimal pedicle screw and tap size was determined to be 2.5 in-lbs, and a comparison tapping IT value of 1.5 in-lbs was selected. Next, 15 test specimens (n=30) were measured with digital calipers, probed, tapped, and instrumented using a paired comparison between the two threshold tapping IT values (Group 1: 1.5 in-lbs; Group 2: 2.5 in-lbs), randomly assigned to the left or right pedicle on each specimen. Each pedicle was incrementally tapped to increasing size (3.75, 4.00, 4.50, and 5.50 mm) until the threshold value was reached based on the assigned group. Pedicle screw size was determined by adding 1 mm to the tap size that crossed the threshold torque value. Torque measurements were recorded with each revolution during tap and pedicle screw insertion. Each specimen was then individually potted and pedicle screws pulled out "in-line" with the screw axis at a rate of 0.25 mm/sec. Peak pullout strength (POS) was measured in Newtons (N).

RESULTS

The peak tapping IT was significantly increased (50%) in Group 2 (3.23 ± 0.65 in-lbs) compared with Group 1 (2.15 ± 0.56 in-lbs) (p=.0005). The peak screw IT was also significantly increased (19%) in Group 2 (8.99 ± 2.27 in-lbs) compared with Group 1 (7.52 ± 2.96 in-lbs) (p=.02). The pedicle screw pullout strength was also significantly increased (23%) in Group 2 (877.9 ± 235.2 N) compared with Group 1 (712.3 ± 223.1 N) (p=.017). The mean pedicle screw diameter was significantly increased in Group 2 (5.70 ± 1.05 mm) compared with Group 1 (5.00 ± 0.80 mm) (p=.0002). There was also an increased rate of optimal pedicle screw size selection in Group 2 with 9 of 15 (60%) pedicle screws compared with Group 1 with 4 of 15 (26.7%) pedicle screws within 1 mm of the measured pedicle width. There was a moderate correlation for tapping IT with both screw IT (r=0.54; p=.002) and pedicle screw POS (r=0.55; p=.002).

CONCLUSIONS

Our findings suggest that tapping IT directly correlates with pedicle screw IT, pedicle screw pullout strength, and optimal pedicle screw size. Therefore, tapping IT may be used during thoracic pedicle screw instrumentation as an adjunct to preoperative imaging and clinical experience to maximize fixation strength and optimize pedicle "fit and fill" with the largest screw possible. However, further prospective, in vivo studies are necessary to evaluate the intraoperative use of tapping IT to predict screw loosening/complications.

Preoperative Halo-Gravity Traction for Severe Pediatric Spinal Deformity: Complications, Radiographic Correction and Changes in Pulmonary Function

BACKGROUND SUMMARY

The use of preoperative halo-gravity traction (HGT) improves both spinal deformity and pulmonary function and is a helpful adjuvant in the treatment of complex spinal deformity. Despite the benefits of preoperative HGT, there is no consensus on the optimal traction protocol.

METHODS

We evaluated the treatment of 33 patients treated with preoperative HGT to determine the safety and efficacy of preoperative HGT with regards to deformity correction; to quantify changes in pulmonary function; and to better define an ideal preoperative traction protocol. All patients were treated at the same tertiary-care pediatric hospital between 1998 and 2007. Inclusion criteria were preoperative HGT (before anterior and/or posterior spinal fusion), pretraction spinal Radiographs, repeat Radiographs taken during the traction period, and repeat Radiographs taken at the completion of traction and final Radiographs after surgical correction. The average duration of preoperative HGT was 70.1 days. The average traction weight applied was 38.5% of total body weight. Maximal traction weight was achieved in an average of 30.5 days.

RESULTS

Our results, 35% correction of the coronal Cobb and 35% correction of the sagittal Cobb, are consistent with others reported in the literature. Pulmonary function tests taken before and after traction were available for 22 patients. Treatment with HGT improved pulmonary function results in 19 patients. There were no serious complications.

CONCLUSION

We found that preoperative HGT is a safe and useful adjuvant to the treatment of patients with severe scoliosis. Significant deformity correction averaging 35% percent can be expected, with the majority of deformity correction occurring after 3 to 4 weeks. In the majority of patients, this correction is maintained or even improved with subsequent surgical correction.

Reliability of radiographic measures for infantile idiopathic scoliosis

BACKGROUND

Radiographic measures such as the rib vertebral angle difference (RVAD), Cobb angle, and space available for the lung (SAL) help to guide treatment and measure treatment effects in patients with infantile idiopathic scoliosis. This study aimed to evaluate the intraobserver and interobserver reliability of these radiographic measures.

METHODS

Forty-five spine radiographs of skeletally immature patients (age, two months to four years) with infantile idiopathic scoliosis were measured with use of Surgimap software. Three pediatric orthopaedic surgeons and a pediatric orthopaedic fellow identified the major curve apex, rib-vertebra phase, Cobb angle, and end vertebrae and calculated the RVAD and SAL values at two separate time points. Interobserver and intraobserver reliability of the RVAD, Cobb angle, and SAL values were assessed with use of intraclass correlation coefficients (ICCs). Fleiss kappa coefficients were calculated for categorical variables.

RESULTS

The RVAD (ICC = 0.86 to 0.92) and Cobb angle (ICC = 0.99) measurements had high reliability. The SAL value had substantial interobserver reliability (ICC = 0.66) and moderate intraobserver reliability (ICC = 0.73). Despite the high agreement for the Cobb angle, the choice of the major curve vertebrae (kappa = 0.19 to 0.39) and apical vertebra varied (kappa = 0.57 to 0.62). Observers were more likely to choose the same apical vertebra in large curves (r = 0.483, p = 0.001). The agreement for the apical rib-vertebra phase was substantial (kappa = 0.67). Paired RVAD measurements fell within ≤ 10° of each other in 82% of cases, but the remaining 18% of the RVAD measurements showed >10° of variation.

CONCLUSIONS

Measurements used to guide treatment of infantile idiopathic scoliosis curves were reliable despite standard radiographic measurement error and the difficulty in obtaining quality images in young patients. Clinicians are dependent on seemingly objective radiographic data. The reliability of the Cobb angle and RVAD measurements in infantile scoliosis was high but not devoid of variability that could skew the ability to accurately and reliably suggest the best course of treatment. The SAL value was a less reliable measure. Treatment recommendations for infantile idiopathic scoliosis should rely on the synthesis of objective and clinically subjective data, as variations in radiographic measurements can lead to inconsistencies in management and to inconsistent treatment outcomes.

The utility of erythrocyte sedimentation rate values and white blood cell counts after spinal deformity surgery in the early (≤3 months) post-operative period

PURPOSE

The erythrocyte sedimentation rate (ESR) and white blood cell (WBC) count are frequently obtained in the work-up of post-operative fever. However, their diagnostic utility depends upon comparison with normative peri-operative trends which have not yet been described. The purpose of this study is to define a range of erythrocyte sedimentation rates and white blood cell counts following spinal instrumentation and fusion in non-infected patients.

METHODS

Seventy-five patients underwent spinal instrumentation and fusion. The erythrocyte sedimentation rate and white blood cell count were recorded pre-operatively, at 3 and 7 days post-operatively, and at 1 and 3 months post-operatively.

RESULTS

Both erythrocyte sedimentation rate and white blood cell count trends demonstrated an early peak, followed by a gradual return to normal. Peak erythrocyte sedimentation rates occurred within the first week post-operatively in 98% of patients. Peak white blood cell counts occurred with the first week in 85% of patients. In the absence of infection, the erythrocyte sedimentation rate was abnormally elevated in 78% of patients at 1 month and in 53% of patients at 3 months post-operatively. The white blood cell count was abnormally elevated in only 6% of patients at 1 month post-operatively. Longer surgical time was associated with elevated white cell count at 1 week post-operatively. The fusion of more vertebral levels had a negative relationship with elevated erythrocyte sedimentation rate at 1 week post-operatively. The anterior surgical approach was associated with significantly lower erythrocyte sedimentation rate at 1 month post-operatively and with lower white cell count at 1 week post-operatively.

CONCLUSION

In non-infected spinal fusion surgeries, erythrocyte sedimentation rates are in the abnormal range in 78% of patients at 1 month and in 53% of patients at 3 months post-operatively, suggesting that the erythrocyte sedimentation rate is of limited diagnostic value in the early post-operative period.

An analysis of suboptimal outcomes of medial malleolus fractures in skeletally immature children

We retrospectively analyzed cases of intra-articular medial malleolar fractures in skeletally-immature patients (Salter-Harris III and IV) with suboptimal outcomes at St. Louis Children's Hospital and Shriner's Hospital for Children. Common causes of poor outcome were frac­ture malunion or malreduction and physeal damage. Malreductions of only 2 mm does not appear to be toler­ated and the concept of "remodeling" does not apply to these fracture patterns. Based on this study, we "recom­mend" fracture reduction and fixation if there is greater than 1 mm of fracture step-off..

Financial analysis of circumferential fusion versus posterior-only with thoracic pedicle screw constructs for main thoracic idiopathic curves between 70 degrees and 100 degrees

PURPOSE

Reports on thoracic pedicle screw (TPS) constructs have demonstrated their safety and efficacy; however, concerns exist regarding their increased cost. This is a review of adolescents with main thoracic scoliosis surgically treated with anterior release and posterior fusion or posterior fusion only. The objectives were to compare the radiographic outcomes and financial data of two surgical treatments: anterior/posterior spinal fusion (APSF) versus posterior spinal fusion (PSF-TPS) alone with TPSs, in patients with large 70-100 degrees main thoracic adolescent idiopathic scoliosis (AIS) curves.

METHODS

We identified 43 patients with main thoracic Lenke type 1-4 AIS curves between 70 and 100 degrees who had been treated with either APSF or PSF-TPS.

RESULTS

Both groups had equivalent radiographic corrections postoperatively. The PSF-TPS group patients had higher implant charges, but the APSF group had higher surgeon procedural charges, operating room charges, anesthesia charges, and inpatient room charges. Total charges were $75,295 for the APSF group and $71,236 for the PSF-TPS group (P > 0.05). Analyses of two subgroups of the APSF group, anterior release via thoracotomy versus VATS and same-day versus staged surgeries, failed to change any of the above findings.

CONCLUSION

Based on this financial analysis, there was no statistically significant differences between the APSF and PSF-TPS groups, with equivalent radiographic corrections.

Use of femoral nerve blocks in adolescents undergoing patellar realignment surgery

The purpose of this study was to analyze the efficacy of femoral nerve blocks (FNBs) in decreasing postoperative narcotic use in adolescents undergoing patellar realignment surgery (PRS). All patients who underwent PRS at 2 children's hospitals between 1998 and 2002 were included in the study. Patients were grouped according to postoperative analgesia: FNB (n = 14), as-needed intravenous morphine (PRN-IV; n = 16), or patient-controlled analgesia using morphine (PCA; n = 13). Total postoperative i.v. morphine use was statistically significantly different among the 3 groups: 9.0 mg for FNB, 26.43 mg for PRN-IV, and 64.7 mg for PCA. FNB use was effective in significantly decreasing postoperative i.v. narcotic use.

Arthroscopic findings at the time of patellar realignment surgery in adolescents

Articular cartilage injuries and loose bodies have been associated with patellar dislocations. At the time of patellar realignment surgery (PRS), direct intraarticular visualization of the structures of concern may be limited with the use of a small arthrotomy. Concomitant diagnostic arthroscopy can improve the identification of intraarticular abnormalities, both patellofemoral and nonpatellofemoral, because of the better field of view.

PURPOSE

This report details the findings from knee arthroscopy performed concomitantly with PRS in adolescents.

METHODS

All patients underwent knee arthroscopy and open PRS for patellar instability, performed by a single surgeon, during a 4-year period. Patient demographics, knee history, clinical examination, operative findings, and treatment details were collected on all patients.

RESULTS

: Thirty-eight patients (mean age, 14.9 years; 41 knees) were included in this analysis. Patellar osteochondral lesions were present in 30 knees (73%; mean size, 112 mm). Femoral lesions were documented in 11 knees (23%; mean size, 81 mm). Loose bodies were present in 6 knees (15%). In 8 patients (20%), an additional 11 nonpatellofemoral diagnoses were made at the time of arthroscopy: lateral tibiofemoral chondroses (n = 4), medial meniscal tear (n = 2), lateral meniscal tear (n = 2), discoid lateral meniscus (n = 1), partial anterior cruciate ligament tear (n = 1), and medial tibiofemoral chondrosis (n = 1). Because of these findings, 5 additional procedures were performed in 4 patients: partial lateral meniscectomy (n = 2), medial meniscal repair (n = 1), discoid meniscus saucerization (n = 1), and staged distal femoral valgus-correcting osteotomy (n = 1).

CONCLUSIONS

By performing concomitant knee arthroscopy at the time of PRS, we were able to identify significant tibiofemoral abnormality in 4 patients, which would have been missed with direct inspection by a limited arthrotomy at the patellofemoral joint. In addition, precise evaluation of the patellofemoral joint permits customization of the PRS and aids in establishing appropriate patient expectations postoperatively. We advocate diagnostic knee arthroscopy at the time of PRS in adolescents to identify all intraarticular abnormalities and to optimize discussions with the patient and the caregivers on the long-term prognosis of the knee.

SIGNIFICANCE

Arthroscopic inspection of the knee at the time of PRS permits identification of abnormality that is not routinely visual by using open arthrotomy. Twenty percent of patients had additional pathological findings; of these patients, 50% underwent an additional surgical procedure.

A new dynamic foot abduction orthosis for clubfoot treatment

Recurrent clubfoot deformity after successful initial correction with the use of the Ponseti method continues to be a common problem and is often caused by noncompliance with wear of the traditional foot abduction brace. The purpose of this study was to assess the results of a newly designed dynamic foot abduction orthosis in terms of (1) parental compliance and (2) effectiveness in preventing recurrent clubfoot deformities. Twenty-eight patients (49 clubfeet) who were treated with a dynamic foot abduction orthosis in accordance with the Ponseti method were included in this study. Of the 28 patients, 18 had idiopathic clubfeet (31 clubfeet), 2 had complex idiopathic clubfeet (4 clubfeet), 5 had myelodysplasia (8 clubfeet), and 3 were syndromic (6 clubfeet). The mean duration of follow-up was 29 months (range, 24-36 months). Noncompliance was reported in only 2 (7.1%) of the 28 patients in the new orthosis compared with the authors' previously reported 41% (21/51) noncompliance rate in patients treated with the use of the traditional foot abduction brace. The two patients in this study, in which parents were noncompliant with orthosis wear, developed recurrent deformities. There were 2 patients (7%) who experienced skin blistering in the new orthosis compared with 12 (23.5%) of 51 patients who experienced blistering with the use of traditional abduction brace in the authors' previously reported study. Logistic regression modeling compliance and recurrence revealed that noncompliance with the foot abduction orthosis was most predictive of recurrence of deformity (odds ratio, 27; 95% confidence interval, 2.2-326; P = 0.01). The articulating foot abduction orthosis is well tolerated by patients and parents and results in a higher compliance rate and a lower complication rate than what were observed with the traditional foot abduction orthosis.

Complications after titanium elastic nailing of pediatric tibial fractures

A retrospective review of 60 diaphyseal tibia fractures (31 closed and 29 open fractures) treated with flexible intramedullary fixation was conducted. All charts and radiographs were reviewed. Children ranged in age from 5.1 to 17 years. Fifty patients with 51 fractures were followed up until union and comprised the study group. The mean follow-up period for these 50 patients was 79 weeks. Forty-five fractures achieved bony union within 18 weeks (mean, 8 weeks). Five patients (11%) had delayed healing (3 had delayed unions that ultimately healed with casting or observation, and 2 had nonunions that required secondary procedures to achieve union [1 patient underwent a fibular osteotomy, and 1 underwent exchange nailing with a reamed tibial nail]). These 5 fractures ultimately healed, with a mean time to union of 41 weeks. Patients with delayed healing tended to be older (mean age, 14.1 years) versus the study population as a whole (mean age, 11.7 years). In addition to delayed union, other complications were observed in the study population. One patient healed with malunion (13-degree valgus), requiring corrective osteotomy. One patient with a grade II open fracture was diagnosed with osteomyelitis at the fracture site after attaining bony union. Two patients developed nail migration through the skin, requiring modification or nail removal. The fixation of pediatric diaphyseal tibia fractures with titanium elastic nails is effective but has a substantial rate of delayed healing, particularly in older patients.

A randomized comparison of nitrous oxide plus hematoma block versus ketamine plus midazolam for emergency department forearm fracture reduction in children

OBJECTIVES

Ketamine provides effective and relatively safe sedation analgesia for reduction of fractures in children in the emergency department. However, prolonged recovery and adverse effects suggest the opportunity to develop alternative strategies. We compared the efficacy and adverse effects of ketamine/midazolam to those of nitrous oxide/hematoma block for analgesia and anxiolysis during forearm fracture reduction in children.

METHODS

Children 5 to 17 years of age were randomly assigned to receive intravenous ketamine (1 mg/kg)/midazolam (0.1 mg/kg; max: 2.5 mg) or 50% nitrous oxide/50% oxygen and a hematoma block (2.5 mg/kg of 1% buffered lidocaine). All of the children received oral oxycodone 0.2 mg/kg (max: 15 mg) at triage > or = 45 minutes before reduction. Videotapes were obtained before (baseline), during (procedure), and after (recovery) reduction and scored using the Procedure Behavioral Checklist by an observer blinded to study purpose. The primary outcome measure was the mean change in Procedure Behavioral Checklist score from baseline to procedure, with greater change indicating greater procedure distress. Other outcome measures of efficacy included recovery times and visual analog scale scores to assess patient distress, parent report of child distress, and orthopedic surgeon satisfaction with sedation. Adverse effects were assessed during the emergency visit and by telephone 1 day after reduction. Data were analyzed using repeated measures, that is, analysis of variance, chi2, and t tests.

RESULTS

There were 102 children (mean age: 9.0 +/- 3.0 years) who were randomly assigned. There was no difference in age, race, gender, and baseline Procedure Behavioral Checklist scores between ketamine/midazolam (55 subjects) and nitrous oxide/hematoma block (47 subjects). Mean changes in Procedure Behavioral Checklist scores were very small for both groups. The mean change in Procedure Behavioral Checklist was less for nitrous oxide/hematoma block, and patients and parents reported less pain during fracture reduction with nitrous oxide/hematoma block. Recovery times were markedly shorter for nitrous oxide/hematoma block compared with ketamine/midazolam. Orthopedic surgeons were similarly satisfied with the 2 regimens. Of the ketamine/midazolam subjects, 11% had O2 saturations < 94%. Other adverse effects occurred in both groups, but more often in ketamine/midazolam both during the emergency visit and at 1-day follow-up.

CONCLUSIONS

In children who had received oral oxycodone, both nitrous oxide/hematoma block and ketamine/midazolam resulted in minimal increases in distress during forearm fracture reduction at the doses studied. The nitrous oxide/hematoma block regimen had fewer adverse effects and significantly less recovery time.

Anterior/posterior spinal instrumentation versus posterior instrumentation alone for the treatment of adolescent idiopathic scoliotic curves more than 90 degrees

STUDY DESIGN

A retrospective review of patients with adolescent idiopathic scoliosis (AIS), with curves more than 90 degrees treated with either a combined anterior/posterior spinal fusion or a posterior spinal fusion alone.

OBJECTIVES

To assess the results of spinal fusion for AIS curves >90 degrees and determine whether the use of a posterior-only approach with an all-pedicle screw construct can decrease the need for anterior release surgery.

SUMMARY OF BACKGROUND DATA

Treatment of AIS curves >90 degrees often consists of anterior release and posterior fusion to improve coronal correction and fusion rate. However, the use of pedicle screws has allowed improved coronal curve correction rates even in large curves, which may decrease the need for anterior release surgery.

METHODS

A total of 54 consecutive patients with AIS with curves >90 degrees who underwent a spinal fusion procedure at 1 institution between 1987 and 2001, with either a combined anterior/posterior spinal fusion (hooks and screws) or a posterior spinal fusion alone with an all-pedicle screw construct, were included for analysis. All patients had a minimum 2-year follow-up (mean 6.0; range 2.0-14.5), and were analyzed radiographically as well as with pulmonary function tests. Statistical analyses were performed between groups using the Wilcoxon-Mann-Whitney tests.

RESULTS

There were 20 patients treated with an anterior/posterior spinal fusion and 34 with a posterior spinal fusion alone. There were no statistically significant differences between the groups for gender, age, number of levels fused, preoperative coronal/sagittal Cobb measurements, coronal curve flexibility, or amount of postoperative coronal Cobb correction. There was less of a negative effect on pulmonary function in the group treated with posterior spinal fusion versus the group treated with a combined anterior/posterior spinal fusion (P < 0.005). There were no complications/reoperations in either group.

CONCLUSION

In this patient population with often restrictive preoperative pulmonary function, a posterior-only approach with the use of an all-pedicle screw construct has the advantage of providing the same correction as an anterior/posterior spinal fusion, without the need for entering the thorax and more negatively impacting pulmonary function.

Femoral deformity in tibia vara

BACKGROUND

Previous studies have suggested that compensatory valgus deformity of the femur is common in patients with tibia vara, or Blount disease. The availability and routine use of standing long-cassette radiographs of the lower extremities to assess angular deformities has allowed quantitative evaluation of this hypothesis.

METHODS

The cases of all patients with tibia vara, two years of age or older, seen at our institution prior to treatment, over a thirteen-year period, were reviewed. Seventy-three patients with a total of 109 involved lower limbs were identified and were classified as having either infantile tibia vara (thirty-seven patients with fifty-six involved limbs) or late-onset tibia vara (thirty-six patients with fifty-three involved limbs). Standardized standing radiographs of the lower extremity were examined to assess the deformity at the distal part of the femur and the proximal part of the tibia by measuring the lateral distal femoral angle and the medial proximal tibial angle.

RESULTS

The distal part of the femur in the children with infantile tibia vara either was normal or had mild varus deformity, with a mean lateral distal femoral angle of 97 degrees (range, 82 degrees to 129 degrees). The mean medial proximal tibial angle in these children was 72 degrees (range, 32 degrees to 84 degrees). Older children with infantile tibia vara were noted to have little distal femoral deformity, with no more than 4 degrees of valgus compared with either normal values or the contralateral, normal limb. Children with late-onset tibia vara had a mean lateral distal femoral angle of 93 degrees (range, 82 degrees to 110 degrees) and a mean medial proximal tibial angle of 73 degrees (range, 52 degrees to 84 degrees). On the average, the varus deformity of the distal part of the femur constituted 30% (6 degrees of 20 degrees) of the genu varum deformity in these patients.

CONCLUSIONS

Patients with infantile tibia vara most commonly had normal alignment of the distal parts of the femora; substantial valgus deformity was not observed. Distal femoral varus constituted a substantial portion of the genu varum in children with late-onset disease. When correction of late-onset tibia vara is planned, the surgeon should be aware of the possibility that distal femoral varus is a substantial component of the deformity.

Diaphyseal derotational osteotomy with intramedullary fixation for correction of excessive femoral anteversion in children

Nearly all children with femoral anteversion spontaneously remodel by age 8. Femoral derotational osteotomies are performed in older children with persistent excessive femoral anteversion when children or adolescents are limited in activities of daily living or sports. Procedures for correction of the anteversion vary, and no one procedure has been shown to be superior. Since 1997 the authors have corrected idiopathic excessive femoral anteversion thorough a diaphyseal osteotomy with fixation using a rigid intramedullary pediatric femoral nail. The purpose of this study was to describe the technique and results of this new technique. A retrospective study was conducted of all femoral derotational osteotomies performed with a pediatric femoral nail in 13 consecutive patients and 21 affected limbs. All patients complained preoperatively of frequent tripping during sports and activities of daily living. The mean preoperative rotation included internal rotation of 77 degrees and external rotation of 15 degrees. Standing AP radiographs of all patients were obtained at final follow-up. All patients were evaluated clinically and radiographically at a minimum of 1 year after surgery. All patients noted improvement in the ability to participate in activities without tripping. No patient limped at final follow-up. No intraoperative or postoperative complications occurred. Healing of the osteotomy was present at a mean of 6 weeks. All osteotomies healed in anatomic alignment. Mean final hip rotation included internal rotation of 40 degrees and external rotation of 57 degrees. No patient had substantial changes of valgus or femoral neck narrowing at final follow-up. Femoral derotational osteotomy with fixation using a small-diameter rigid intramedullary nail placed through the lateral aspect of the greater trochanter is a safe, accurate, and effective method of correcting excessive femoral anteversion in symptomatic children.

Outcome of hemiepiphyseal stapling for late-onset tibia vara

BACKGROUND

The results of hemiepiphysiodesis for the treatment of late-onset tibia vara have been reported to be favorable, but the technique requires careful timing and an accurate estimation of skeletal age. Hemiepiphyseal stapling does not require a careful estimation of skeletal age, and it has been reported to yield good results with low morbidity. However, we are not aware of any study evaluating the intermediate-term radiographic results or complications of this procedure.

METHODS

Twenty-six patients with thirty-three extremities with late-onset tibia vara were treated with proximal tibial hemiepiphyseal stapling. Fourteen extremities had substantial concomitant distal femoral varus and also had hemiepiphyseal stapling of the distal part of the femur. Eighteen patients (twenty-three involved extremities) had juvenileonset tibia vara and eight patients (ten involved extremities) had adolescent-onset tibia vara. The mean age at the time of stapling was 11.8 years. The mean duration of follow-up was 3.8 years. We reviewed standardized standing radiographs to determine the mechanical axis deviation, the medial proximal tibial angle, the lateral distal femoral angle, and the zone of the knee through which the mechanical axis passed.

RESULTS

The mean mechanical axis deviation improved from 58 mm (range, 27 to 157 mm) preoperatively to 22 mm (range, -33 to 117 mm) at the time of the last follow-up, and the mean medial proximal tibial angle improved from 77 degrees (range, 50 degrees to 85 degrees ) to 85 degrees (range, 48 degrees to 95 degrees ). In the fourteen lower extremities in which distal femoral hemiepiphyseal stapling was performed, the mean lateral distal femoral angle improved from 96 degrees (range, 92 degrees to 100 degrees ) to 86 degrees (range, 79 degrees to 97 degrees ). At the time of the final follow-up, seven extremities were considered to be in moderate varus; four, in mild varus; twenty, in normal alignment; and two, in valgus. No differences in radiographic outcome were noted between the juvenile and adolescent forms of tibia vara. Only one of the four extremities with severe preoperative varus was corrected to normal alignment; the remaining three were left with moderate varus.

CONCLUSIONS

Hemiepiphyseal stapling of the lateral aspect of the proximal tibial physis and, as needed, the lateral aspect of the distal femoral physis is safe and effective in children with late-onset tibia vara if the physes are sufficiently open and the varus deformity is mild to moderate. Hemiepiphyseal stapling is particularly effective in patients who are ten years of age or younger.

LEVEL OF EVIDENCE

Therapeutic Level IV.

Thoracic adolescent idiopathic scoliosis curves between 70 degrees and 100 degrees: is anterior release necessary?

STUDY DESIGN

A retrospective review of adolescents with main thoracic scoliotic curves surgically treated with either anterior release and posterior fusion or posterior fusion only.

OBJECTIVES

To compare the radiographic and clinical outcomes of two surgical treatments: anterior-posterior spinal fusion (APSF) versus posterior spinal fusion (PSF) alone in patients with large 70 degrees to 100 degrees thoracic adolescent idiopathic scoliosis (AIS) curves.

SUMMARY OF BACKGROUND DATA

Surgical treatment of thoracic AIS curves between 70 degrees and 100 degrees often consists of anterior and posterior fusion to improve the coronal correction and fusion rate, with the anterior release and fusion performed through either an open thoracotomy or by video-assisted thoracoscopy.

METHODS

All patients (n = 84) with main thoracic major AIS curves between 70 degrees and 100 degrees who underwent spinal fusion (APSF or PSF) at one center between 1987 and 2001 were included for analysis. The minimum follow-up was 2 years after surgery (mean, 4.5 years; range, 2.0-10.2 years). The mean age of patients was 13.8 years (range, 10.7-18.2 years), with 66 females and 18 males. Multiple radiographic measures were assessed. The primary and secondary statistical analyses performed were nonparametric analyses, using the Wilcoxon-Mann-Whitney tests for the primary analysis of APSF and PSF groups. The PSF subgroup analysis was performed with the Kruskal-Wallis test.

RESULTS

There were 22 patients in the APSF (open ASF in 18, and video-assisted thoracoscopy in 4) group and 62 patients in the PSF group. There were no statistically significant differences between the groups for gender, age, number of levels fused, Cobb measurement of preoperative coronal or sagittal thoracic curve magnitude, or coronal curve flexibility. The APSF group, when compared with the PSF group, had greater intraoperative correction of the coronal curve (48.3 degrees vs. 38.7 degrees, P = 0.0087) as well as final overall correction (47.2 degrees vs. 34.2 degrees, P = 0.0008). There were no significant differences seen in the sagittal alignment from T5-T12 (P = 0.3150) or the SRS outcomes data between the APSF and PSF only groups. Subanalysis of the PSF only group identified three distinct groups based on implants: hook-only constructs (n = 36), hybrid constructs of proximal hooks and distal pedicle screws (n = 15), and pedicle screw-only constructs (n = 11). Pedicle screw-only constructs corrected the coronal Cobb measurements more than the other two groups (47.5 degrees vs. hooks 37.7 degrees vs. hybrid 34.4 degrees , P = 0.0110), and to a similar extent as to the APSF group with no statistically significant difference in coronal correction (PSF, 47.5 degrees; APSF 48.3 degrees; P = 0.9014), nor any other parameter except for sagittal T5-T12 changes. There were no reoperations for implant failure/pseudarthroses in any of the patients.

CONCLUSION

APSF of large thoracic curves allows greater coronal correction of thoracic curves between 70 degrees and 100 degrees, when compared with PSF alone using thoracic hook constructs, but not with the use of thoracic pedicle screw constructs. Scoliosis surgeons not using pedicle screw constructs need to decide if the modest improvement in coronal correction with a combined approach justifies its routine use in this patient population.

Use of bone morphogenetic protein-2 for adult spinal deformity

STUDY DESIGN

Prospective, single-center, nonblinded clinical and radiographic analysis of consecutive adult deformity patients treated with recombinant human bone morphogenetic protein-2 (rhBMP-2) without iliac or rib bone graft supplementation.

OBJECTIVES

To determine the ability of rhBMP-2 to achieve both anterior and posterior spinal fusion in patients undergoing multilevel fusions for adult spinal deformity.

SUMMARY OF BACKGROUND DATA

The literature concerning one-level anterior fusions, and potentially one-level posterior fusions, using rhBMP-2 has demonstrated clinical efficacy. No published data exist on the use of rhBMP-2 in multilevel spine fusions.

METHODS

Prospective analysis of patients treated with rhBMP-2 in multilevel anterior and posterior fusions with a minimum 1-year follow-up. There were a total of 95 patient samples (70 total patients; 25 patients had rhBMP-2 used circumferentially): 46 anterior fusions (Group 1), 41 posterior fusions (Group 2), and 8 patients were "compassionate use" fusions (Group 3). In the anterior fusion group (n = 46), mean rhBMP-2/level was 10.8 mg in titanium mesh cages without any bone graft or other substance. The posterior fusion group had only local bone graft, no harvested rib or iliac bone graft (n = 41). The mean rhBMP-2/level was 13.7 mg. The "compassionate use" group (n = 8 patients) consisted of patients who had prior surgeries, prior iliac harvesting, and substantial comorbidities and therefore a higher concentration and different carrier was used. No local bone graft, no harvested bone was used. The mean rhBMP-2/level was 28.6 mg. The median dose was 40 mg for Group 3.

RESULTS

For the anterior fusion group (n = 46), operative levels were deemed fused in 89 of the 93 (96%) levels. For the posterior fusion group (n = 41), a solid fusion was assessed in 110 of the 118 (93%) operative levels. For the "compassionate-use" patients, the overall fusion rate was 100% (52 of 52 operative levels).

CONCLUSIONS

With the use of rhBMP-2, a high rate of apparent fusion was observed for anterior (96%) and posterior (93%) fusions in adult spinal deformity patients. Use of rhBMP-2 results in a promising early fusion rate without the graft harvest site morbidity.

Magnetic resonance imaging of the knee in children and adolescents. Its role in clinical decision-making

BACKGROUND

Recent studies have questioned the utility of magnetic resonance imaging in the diagnosis of pediatric knee disorders because of the morphologic changes during growth and the low accuracy of the formal interpretation of the magnetic resonance imaging scan by a radiologist. The purpose of this study was twofold: (1) to report the accuracy of formal interpretations of magnetic resonance imaging scans of the knee in children and adolescent patients by a radiologist, and (2) to determine the benefit, if any, of a personal review of the magnetic resonance imaging scan of the knee by the orthopaedic surgeon, as a routine part of the diagnostic evaluation.

METHODS

A three-year prospective study of all patients who underwent knee arthroscopy performed by a single surgeon, at two children's hospitals, was completed. The analysis focused on the six most common diagnoses: anterior cruciate ligament tear, lateral meniscal tear, medial meniscal tear, osteochondritis dissecans, discoid lateral meniscus, and osteochondral fracture. The preoperative diagnosis of the surgeon was determined by integrating the history and the findings on the clinical examination, plain radiographs, and magnetic resonance imaging scans (including the radiologist's interpretation).

RESULTS

Ninety-six patients with ninety-six abnormal knees were included. The mean age was 14.6 years at the time of surgery. Relative to operative findings, kappa values for the formal interpretations of the magnetic resonance imaging scans by a radiologist were 0.78 for an anterior cruciate ligament tear, 0.76 for a medial meniscal tear, 0.71 for a lateral meniscal tear, 0.70 for osteochondritis dissecans, 0.46 for discoid lateral meniscus, and 0.65 for osteochondral fracture. Relative to operative findings, kappa values for the preoperative diagnoses by the surgeon were 1.00 for an anterior cruciate ligament tear, 0.90 for a medial meniscal tear, 0.92 for a lateral meniscal tear, 0.93 for osteochondritis dissecans, 1.00 for discoid lateral meniscus, and 0.90 for osteochondral fracture. The preoperative diagnosis by the surgeon was better (p < 0.05) than the formal interpretation of the magnetic resonance imaging scans by the radiologist with respect to an anterior cruciate ligament tear, lateral meniscal tear, osteochondritis dissecans, and discoid lateral meniscus.

CONCLUSIONS

Integration of patient information with an orthopaedic surgeon's review of the magnetic resonance imaging scan of the knee in children and adolescent patients improves the identification of pathological disorders in four of the six categories evaluated. This study questions the necessity for and appropriateness of a routine interpretation of a magnetic resonance imaging scan of the knee in children and adolescents by a radiologist.

Primary and delayed closure after open irrigation and debridement of septic arthritis in children

Seventy-one patients with 83 septic joints due to idiopathic septic arthritis were investigated retrospectively. Forty-three joints were closed primarily while 40 underwent delayed primary closure. Two joints in each group failed treatment and had to be reopened after definitive closure. Joints in patients 7 years of age or older had a substantially higher failure rate (12%), with either primary or delayed closure, than joints in patients younger than 7 years (1.7%). Two of 13 patients with a polymorphonuclear leukocyte count in the synovial fluid greater than 100,000 required repeat debridement after final closure. Three of the four patients who required repeat debridement showed evidence of osteomyelitis. The average length of stay was longer in the delayed primary closure group (7.0 days) than in the primary closure group (5.6 days). This study suggests that primary closure is a viable alternative to delayed primary closure with shorter hospital stays and similar outcomes in children with idiopathic septic arthritis. Care should be taken in children aged 7 and older or when concurrent osteomyelitis exists.

Smoking and socio-economic status in the etiology and severity of Legg-Calvé-Perthes' disease

BACKGROUND

The etiology of Legg-Calvé-Perthes disease is poorly understood. An association has been found in the past between Legg-Calvé-Perthes disease and smoking as well as low socio-economic status.

METHODS

A prospective study was carried out in which families with a child diagnosed with Legg-Calvé-Perthes' disease were interviewed about the presence and duration of household second-hand smoke exposure to children. A control group of randomly selected families seen at our institution were interviewed with identical questions. The radiographs of children with Legg-Calvé-Perthes disease were reviewed and classified according to the Herring lateral pillar classification system.

RESULTS

Thirty-eight of the 60 patients (63.3%) with Legg-Calvé-Perthes disease were noted to have at least one smoker living in the child's household with a mean of 1.03 smoker-years per year of life exposure to smoke. The median income of the patients with Legg-Calvé-Perthes disease was USD 20,300. The median income of the patients in the control group was USD 17,000. Thirty-eight of the 96 control patients (39.6%) were noted to have at least one smoker living in the child's household with a mean of 0.48 smoker-years per year of life. A significant association was noted between living with a smoker and Legg-Calvé-Perthes disease as well as between increasing smoke exposure and increased risk of developing Legg-Calvé-Perthes disease. No significant association was noted between lower income and Legg-Calvé-Perthes disease. There was no association between increased smoke exposure and increased severity of Legg-Calvé-Perthes disease as measured by the lateral pillar classification.

CONCLUSIONS

The presence of second-hand smoke seems to be a significant risk factor in the development of Legg-Calvé-Perthes disease. The presence of second-hand smoke may represent the 'unknown industrial factor' that has been discussed.

Emergency department management of pain and anxiety related to orthopedic fracture care: a guide to analgesic techniques and procedural sedation in children

Orthopedic fractures and joint dislocations are among the most painful pediatric emergencies. Safe and effective management of fracture-related pain and anxiety in the emergency department reduces patient distress during initial evaluation and often allows definitive management of the fracture. No consensus exists on which pharmacologic regimens for procedural sedation/analgesia are safest and most effective. For some children, control of fracture pain is the primary goal, whereas for others, relief from anxiety is an additionally important objective. Furthermore, strategies for the management of fracture pain may vary by fracture location and patient characteristics; thus, no single regimen is likely to provide the best means of analgesia and anxiolysis for all patients. Effective analgesia can be provided by local or regional anesthesia, such as hematoma, Bier, or nerve blocks. Alternatively, induction of deep sedation with analgesic agents such as ketamine or fentanyl, often combined with sedative-anxiolytic agents such as midazolam, may be used to manage distress associated with fracture reduction. A combination of local anesthesia with moderate sedation, for example nitrous oxide, is another attractive option.