Journal of Pediatric Orthopaedics

Feed Category: 

End Vertebra Versus Apical Vertebra: Where Are We More Likely to Misplace in Spine Deformity?

imageBackground Data:
Pedicle screws placement remains technically demanding. The thoracic curve apex is considerably difficult due to its unique morphology and severe rotation. In comparison the upper end vertebrae have smaller pedicles and limited soft tissue exposure. This study seeks to evaluate the likelihood of screw misplacement at the end vertebra and apex.
Methods:
A retrospective review of preoperative and postoperative computed tomographic (CT) scans of spinal deformity patients who underwent posterior spinal fusion with pedicle screw constructs between 2004 and 2011 was performed. Pedicles located at the upper instrumented vertebra (UIV) and lower instrumented vertebra (LIV), and the major and minor apices were evaluated. Pedicle morphology was studied on preoperative CT and screw placement on postoperative CT.
Results:
In total, 188 patients met the inclusion criteria, 172 had preoperative CT scans and 133 had postoperative CT scans. The UIV had a significantly lower percentage of normal pedicles (type A) compared with apex major, apex minor, or LIV (59.1% vs. 76.1% vs. 77.3% vs. 98.7%; P<0.001). UIV had significantly the lowest percentage of normal normally placed screws compared with LIV, apex major, or apex minor (69.4% vs. 97.3% vs. 87.6% vs. 92.1%; P<0.001). In a logistic regression adjusted for preoperative Cobb angles, UIV was more likely to have screws misplaced (odds ratio =7.56; 95% confidence interval, 4.01-14.30; P<0.001) and abnormal pedicles (odds ratio=2.81; 95% confidence interval, 1.52-5.19; P=0.001) compared with any other location studied. In abnormal pedicles, 41 (39.8%) of the 103 UIV screws were misplaced, whereas 10 (16.4%) of the 61 apex major, apex minor, or LIV screws were misplaced (P=0.007).
Conclusions:
The UIV presents more of a risk for pedicle screw misplacement and abnormal morphology when compared with LIV and apical vertebra. We believe these findings can aid in the surgeon’s preoperative and intraoperative management to ensure increased success in accurate and safe pedicle screw placement.
Level of Evidence:
Level III.

Feed Item Url: 
https://journals.lww.com/pedorthopaedics/Fulltext/2020/02000/End_Vertebra_Versus_Apical_Vertebra__Where_Are_We.1.aspx

Relationship Between Sever Disease and Skeletal Maturity

imageBackground:
Sever disease is a common condition in active, growing children. This condition presents as pain in the heel and is thought to be an overuse condition of the calcaneal apophysis. There are currently no defined radiographic diagnostic criteria for evaluation of Sever disease, with radiographs generally showing normal appearance of the calcaneal apophysis. A better understanding of the relationship of Sever disease and skeletal maturity may allow for improved interpretation of radiographs when trying to diagnose this condition.
Methods:
ICD-9 code 732.5 was used to search for patients diagnosed with Sever disease from 2007 to 2015 at a single hospital. For every patient with Sever disease with available calcaneal imaging within 40 days of diagnosis, heel x-rays were staged for calcaneal maturity score using a previously described calcaneal skeletal maturity assessment system. Controls matched by age, race, and sex were evaluated for calcaneal stage to compare with the Sever patients.
Results:
The chart review yielded 78 patients diagnosed with Sever disease by the orthopaedic attending, 39 of which have x-rays around the time of diagnosis. Calcaneal scores averaged 2.2±0.8 for all patients, 2.1±0.9 for male individuals, and 2.3±0.8 for female individuals. The average age for male individuals was 10.4±1.9 years and for female individuals, 9.2±2.2 years. The ages of diagnosis were similar for patients with and without x-rays. Twenty-two of 39 patients with Sever disease were calcaneal stage 2, and 37 of 39 were stages 1, 2, or 3. We calculated the absolute difference from stage 2 for the Sever and control groups. Mean difference from stage 2 was 0.51±0.68 for the Sever patients and 0.95±0.79 for control patients (P=0.01).
Conclusion:
Sever disease occurs in a very narrow range of skeletal maturity, as measured by the calcaneal skeletal maturity assessment system and our observations with chronological age. When compared with age-matched and race-matched controls, stage 2 was seen more frequently in the Sever patients. If a child is not within calcaneal stages 1, 2, or 3, then a different diagnosis should be considered.
Level of Evidence:
Level III—retrospective case-control study.

Feed Item Url: 
https://journals.lww.com/pedorthopaedics/Fulltext/2020/02000/Relationship_Between_Sever_Disease_and_Skeletal.17.aspx

High Risk of Mismatch Between Sanders and Risser Staging in Adolescent Idiopathic Scoliosis: Are We Guiding Treatment Using the Wrong Classification?

imageBackground:
Despite known limitations, Risser staging has traditionally been the primary marker of skeletal maturity utilized in decision-making for treatment of adolescent idiopathic scoliosis (AIS). The purpose of this study is to assess the incidence and factors associated with mismatch between Risser Staging and Sanders classification, and determine interobserver reliability.
Methods:
We reviewed the medical records of consecutive patients aged 10 to 18 referred to our institution for evaluation of AIS from January to June 2016 with a closed triradiate cartilage. Data collected included sex, age, race, height, weight, body mass index percentile, menarchal status, Risser stage, Sanders classification, and major curve. Risser and Sanders stage was determined by 2 fellowship-trained pediatric spine surgeons and 1 pediatric orthopaedic nurse practitioner. Mismatch was defined as Risser stage 2 to 4 corresponding to Sanders 3 to 5, and Risser 0 to 1 corresponding to Sanders 6 to 7.
Results:
A total of 165 consecutive patients were identified (mean age: 13.9±1.7 y, major curve 28.2±15.4 degrees, 76% female). The risk of skeletal maturity mismatch, based on the criteria of Risser 2 to 5 (limited growth remaining) corresponding to Sanders 3 to 5 (significant growth remaining) was 21.8%, indicating that 1 of 5 patients would be undertreated if managed by Risser criteria. Conversely, the mismatch risk for Risser 0 to 1 corresponding to Sanders 6 to 7 was 3.6%, leading such patients to be treated conservatively longer than necessary. Males and those of Hispanic ethnicity were at a higher risk of mismatch (23.1% vs. 11.9%, P=0.08; 33.3% vs. 8.8%, P=0.04, respectively). Body mass index percentile, race, and major curve were not associated with mismatch. The unweighted and weighted interobserver κ for Risser staging was 0.74 and 0.82, respectively, and 0.86 and 0.91 for Sanders classification, respectively.
Conclusion:
Given the limited sensitivity of Risser staging during peak growth velocity, high mismatch risk, and lower interobserver reliability, the Sanders classification should be utilized to guide treatment options in patients with AIS. Compared with Sanders, utilizing Risser staging results in mistreatment in a total of 1 of 4 patients, with the vast majority being undertreated.
Level of Evidence:
Level II.

Feed Item Url: 
https://journals.lww.com/pedorthopaedics/Fulltext/2020/02000/High_Risk_of_Mismatch_Between_Sanders_and_Risser.2.aspx

Tension Band Plate (TBP)-guided Hemiepiphysiodesis in Blount Disease: 10-Year Single-center Experience With a Systematic Review of Literature

imageBackground:
Primary treatment for Blount disease has changed in the last decade from osteotomies or staples to tension band plate (TBP)-guided hemiepiphysiodesis. However, implant-related issues have been frequently reported with Blount cases. The purpose of our study is to evaluate the surgical failure rates of TBP in Blount disease and characterize predictors for failure.
Methods:
We performed an Institutional Review Board–approved retrospective chart-review of pediatric patients with Blount disease to evaluate the results of TBP from 2008 to 2017 and a systematic literature review. Blount cases defined as pathologic tibia-vara with HKA (hip-knee-ankle) axis and MDA (metaphyseal-diaphyseal angle) deviations ≥11 degrees were included in the analysis. Surgical failure was categorized as mechanical and functional failure. We studied both patient and implant-related characteristics and compared our results with a systematic review.
Results:
In 61 limbs of 40 patients with mean follow-up of 38 months, we found 41% (25/61) overall surgical failure rate and 11% (7/61) mechanical failure rate corresponding to 11% to 100% (range) and 0% to 50% (range) in 8 other studies. Statistical comparison between our surgical failure and nonfailure groups showed significant differences in deformity (P=0.001), plate material (P=0.042), and obesity (P=0.044) in univariate analysis. The odds of surgical failure increased by 1.2 times with severe deformity and 5.9 times with titanium TBP in the multivariate analysis after individual risk-factor adjustment. All 7 mechanical failures involved breakage of cannulated screws on the metaphyseal side.
Conclusions:
Most of the studies have reported high failure rates of TBP in Blount cases. Besides patient-related risk factors like obesity and deformity, titanium TBP seems to be an independent risk factor for failure. Solid screws were protective for mechanical failure, but not for functional failure. In conclusion, efficacy of TBP still needs to be proven in Blount disease and implant design may warrant reassessment.
Level of Evidence:
Level III—retrospective comparative study with a systematic review.

Feed Item Url: 
https://journals.lww.com/pedorthopaedics/Fulltext/2020/02000/Tension_Band_Plate__TBP__guided_Hemiepiphysiodesis.18.aspx

Risk Factors for Postoperative Distal Adding-on in Lenke Type 1B and 1C and its Influence on Residual Lumbar Curve

imageBackground:
Distal adding-on (DA) in adolescent idiopathic scoliosis is a radiographic complication that can negatively affect clinical results. However, the risk factors for DA and the influences of DA on the residual lumbar curves have not been fully elucidated in Lenke type 1B and 1C curves. The objective of this study was to investigate risk factors for postoperative DA in Lenke type 1B and 1C curves, and the influence of DA on residual lumbar curves.
Methods:
We retrospectively evaluated 46 adolescent idiopathic scoliosis patients with Lenke type 1B or 1C curves who underwent posterior correction and fusion surgery with selective thoracic fusion. Patients were grouped according to the presence or absence of DA on radiographs at the 2-year follow-up. We compared coronal radiographic parameters between the 2 groups, including the Cobb angle, L4 tilt angle, apical translation, and relative positions of the end vertebra (EV), stable vertebra (SV), neutral vertebra (NV), and last touching vertebra (LTV) to the lower instrumented vertebra (LIV).
Results:
DA was present in 11 patients (24%) at the 2-year follow-up, and the mean LIV-EV, LIV-NV, LIV-SV, and LIV-LTV relative positions were significantly smaller in the DA than in the non-DA group. Preoperative radiographic parameters were similar between the 2 groups, including the mean L4 tilt angle (non-DA, −8±4 degrees; DA, −7±4 degrees). At the 2-year follow-up, the mean apical translation of the lumbar curve was smaller in the DA group (non-DA, −16±8 mm; DA, −7±11 mm) and the mean L4 tilt angle was significantly more horizontalized (non-DA, −8±4 degrees; DA, −1±5 degrees). Multivariate analysis showed that the number of levels between the LIV and LTV (LIV-LTV) was significantly associated with DA.
Conclusions:
A LIV at or cranial to the LTV was a significant risk factor for postoperative DA in Lenke type 1B and 1C curves. Spontaneous correction of the residual lumbar curve was superior in patients with DA.
Level of Evidence:
Level III.

Feed Item Url: 
https://journals.lww.com/pedorthopaedics/Fulltext/2020/02000/Risk_Factors_for_Postoperative_Distal_Adding_on_in.3.aspx

Eight Years of the Pediatric Orthopaedic Fellowship Match: What Have We Learned?

imageBackground:
Pediatric orthopaedic surgery fellowships in North America have been organized, assigned, and administered through the San Francisco Match Program since 2011. However, trends in application numbers and match rates have not been assessed to this point. The purpose of this study is to describe these trends and applicants’ perspective of the fellowship match.
Methods:
The San Francisco Match databank was queried for program and applicant data from 2011 to 2018. Specifically, we obtained data regarding the number of applicants, programs, match rates, and match results. Each year, applicants also completed an anonymous post-match survey administered by the Pediatric Orthopaedic Society of North America fellowship committee, which included information on the number of applications, interview process, estimated costs, and suggested changes. Descriptive statistics were used to summarize the data, and univariate statistics were used to assess differences in categorical and continuous variables.
Results:
From 2011 to 2018, 524 applicants participated in the pediatric orthopaedic fellowship match, and the mean number of annual applicants was 66 (range, 55 to 76). The mean number of fellowship programs and available positions during the same time period was 43 (range, 40 to 47) and 69 (range, 63 to 74), respectively. Each fellowship interview was estimated by the applicant to cost a mean of $458 (range, $372 to $566), and annual application costs across all applicants were extrapolated to be over $200,000/year. The mean overall match rate was 81% (range, 74% to 91%). The mean match rate for North American applicants was 98.7% and international applicants were 40.9% (P<0.01). Approximately, 93% of applicants obtained one of their top 5 choices of fellowship program (range, 78% to 100%), and 50% of matched applicants obtained their top choice each year (range, 43% to 56%).
Conclusion:
In the pediatric orthopaedic fellowship match, the number of applicants and fellowship programs has remained relatively stable over the study period, and the majority of applicants match one of their top choices for fellowship. Proposed changes to the match should focus on decreasing the financial burden on applicants.
Level of Evidence:
Level II.

Feed Item Url: 
https://journals.lww.com/pedorthopaedics/Fulltext/2020/02000/Eight_Years_of_the_Pediatric_Orthopaedic.19.aspx

Changes in the Position of the Junctional Vertebrae After Posterior Spinal Fusion in Adolescent Idiopathic Scoliosis: Implication in Risk Assessment of Proximal Junctional Kyphosis Development

imageBackground:
The development of proximal junctional kyphosis (PJK) after posterior spinal fusion in adolescent idiopathic scoliosis is a major problem. Changes in the global sagittal parameters as they relate to PJK have been reported after surgery, however, the relationships between the changes in the upper-instrumented vertebra (UIV) during and after surgery as they relate to development of PJK have not been quantified. We hypothesize that the compensatory changes in the unfused segments of the spine over time are correlated with the surgically induced changes in the UIV position.
Methods:
Sixty adolescent idiopathic scoliosis patients (with at least 1-year follow-up) who underwent posterior spinal surgery were included retrospectively. Global spinal parameters were calculated using 3-dimensional models of the spine, additional parameters [proximal junctional kyphosis angle (PJKA), cervical lordosis angle] were measured manually before surgery and at 3 postoperative follow-ups. The 3-dimensional position of the vertebral body centroids was calculated for T1, UIV, and lower-instrumented vertebra at all timepoints. The sagittal position of T1, UIV, and lower-instrumented vertebra were correlated to the cervical lordosis, PJKA, lumbar lordosis, and pelvic tilt.
Results:
The position of T1 and UIV were significantly more anterior at first erect for patients who developed PJK. The posterior shift of UIV at the most recent follow-up as compared with the preoperative position was significant in both the PJK and non-PJK cohort. A larger anterior shift in UIV at first erect correlated with a larger T1 and UIV posterior shift at the most recent follow-up. At the most recent follow-up, a more posterior position of the UIV correlated with a larger angle of PJKA (P<0.05).
Conclusion:
Both a larger anterior shift of UIV between preoperative and first erect and a more posterior position of UIV at the most recent follow-up was correlated with a higher PJKA. A larger anterior shift in the position of the UIV after surgery was associated with a higher posterior shift of UIV at the last follow-up. The surgically induced changes in the UIV are an important parameter associated with the development of PJK.
Level of Evidence:
Level IV.

Feed Item Url: 
https://journals.lww.com/pedorthopaedics/Fulltext/2020/02000/Changes_in_the_Position_of_the_Junctional.4.aspx

Nonossifying Fibromas: A Computed Tomography–based Criteria to Predict Fracture Risk

imageBackground:
Nonossifying fibroma (NOF) is the most common benign osseous lesion in children; however, our understanding of which lesions progress to a fracture remains unclear. In this study, we seek to formulate a classification system for NOFs to assess for fracture risk and determine what this classification system tells us regarding fracture risk of the distal tibia and distal femur NOFs.
Methods:
Charts were retrospectively reviewed for patients with NOFs. A 4-point criteria was created and used to calculate fracture risk for distal tibia and distal femur NOFs. The analysis included incidence, specificity, and sensitivity.
Results:
One point was given for each of the following findings on computed tomography (CT) scan: (1) >50% width on coronal view; (2) >50% width on sagittal view; (3) any cortical breach; (4) lack of a neocortex. In total, 34 patients with NOFs of the distal tibia had CT scans, of which 14 fractured. Zero with a 0- or 1-point score fractured, 2 with a 2-point score fractured (20%), 4 with a 3-point score fractured (44%), and 8 with a 4-point score fractured (100%). Sensitivities of 1-, 2-, 3-, and 4-point scores were 100%, 100%, 85.7%, and 57.1%, respectively, and specificities were 71.4%, 71.4%, 80%, and 100%, respectively. A total of 41 patients with NOFs of the distal femur had CT scans, of which 5 fractured. Zero with a 0-point score fractured, 1 with a 1-point score fractured (4%), 0 with a 2-point score fractured, 1 with a 3-point score fractured (20%), and 3 with a 4-point score fractured (100%). Sensitivities of 1-, 2-, 3-, and 4-point scores were 100%, 80%, 80%, and 60%, respectively; and specificities were 60%, 87.8%, 90%, and 100%, respectively.
Conclusions:
Our 4-point CT criteria is easy to apply and identifies patients at high risk of fracture, helping surgeons make decisions regarding treatment.
Level of Evidence:
Level IV—prognostic study.

Feed Item Url: 
https://journals.lww.com/pedorthopaedics/Fulltext/2020/02000/Nonossifying_Fibromas__A_Computed_Tomography_based.20.aspx

C1-C2 Pedicle Screw Fixation for Pediatric Atlantoaxial Dislocation: Initial Results and Long-term Follow-up

imageBackground:
There are few studies reporting the use of atlantoaxial pedicle screws and the long-term effects of C1-C2 posterior fusion in children. Our study is to investigate the initial results of C1-C2 pedicle screw fixation for pediatric atlantoaxial dislocation (AAD) and assessed spontaneous change of postoperative radiography after a long-term follow-up period.
Methods:
Posterior pedicle screw fixations were performed in 21 pediatric patients with AAD. All the patients underwent implant removal 1 year after their initial surgery and had regular follow-up with an average duration of 76.4 months (range, 52 to 117 mo). Clinical and radiographic data were then collected and compared.
Results:
Frankel Grade was significantly improved at 3 months follow-up compared with pretreatment values. All patients had good bony fusion at a mean of 4.2±0.9 months (range, 3 to 6 mo) after treatment. None of the patients experienced worsening neurological symptoms or injury to the vertebral artery. However, 2 cases experienced minor complications. Following removal of the implants, no spinal deformities or subaxial instabilities were found. The mean angle of sagittal curvature increased from 12.1±2.4 degrees (range, 0 to 22 degrees) immediately postoperatively to 19.1±2.7 degrees (range, 6 to 31 degrees) at the final follow-up (P>0.05).
Conclusions:
The results demonstrated that C1-C2 pedicle screw fixation could achieve satisfactory initial results for the management of the pediatric AAD. Moreover, removal of the metal implant after bony fusion did not increase the risk of spinal deformity or subaxial instability at long-term follow-up.

Feed Item Url: 
https://journals.lww.com/pedorthopaedics/Fulltext/2020/02000/C1_C2_Pedicle_Screw_Fixation_for_Pediatric.5.aspx

The Introduction of a Preoperative MRI Protocol Significantly Reduces Unplanned Return to the Operating Room in the Treatment of Pediatric Osteoarticular Infections

imageBackground:
Pediatric osteoarticular infection can cause severe morbidity. Some infectious loci may be difficult to identify clinically, and there may be more than one. There is little agreement regarding the appropriate use of preoperative magnetic resonance imaging (MRI) in this setting. After noting an unacceptably high rate of unplanned returns to the operating room for recurrent infection, clinicians at a tertiary care children’s hospital noticed many patients had adjacent foci of infection on postoperative MRI. As a result, patients experienced prolonged treatment courses and multiple surgeries. An interdisciplinary team instituted practice guidelines whereby all patients with suspected osteoarticular infection underwent MRI for planned debridement during a reserved morning slot with a surgical suite on hold to proceed directly to surgery if indicated. Images were reviewed in real time to form the surgical plan. Young patients that required sedation for MRI were taken to surgery under the same anesthetic used for MRI without being awakened. The purpose of our retrospective study is to determine if implementing the practice guidelines for acute management of osteoarticular infection reduced unplanned returns to the operating room.
Methods:
A total of 93 patients with osteoarticular infection were included in this study. A total of 40 cases, group A, were treated before implementing practice guidelines; 53 cases, group B, were treated after implementing practice guidelines. Our primary outcomes of interest were the identification of adjacent infections prior to surgery and need for repeat surgery, either planned or unplanned.
Results:
Implementation of these guidelines reduced repeat surgery from 50% of patients to <27% (P=0.0099). Of patients requiring repeat surgery, 85% (n=17) were unplanned in group A versus 60% (n=9) in group B (P=0.0099). Adjacent infections were identified in 47.5% (n=19) of patients in group A, versus 60% (n=32) in group B. Adjacent infections were known before surgery in 32% (n=6) of patients in group A versus 72% (n=23) in group B. There were no statistically significant differences in initial patient characteristics or sites of infection.
Conclusions:
Implementing these guidelines reduced the need for repeat surgery in this population. It is difficult to predict with sufficient accuracy which patients need preoperative MRI. While resource intensive, preoperative MRI appears to offer substantial benefit in preoperative planning.

Feed Item Url: 
https://journals.lww.com/pedorthopaedics/Fulltext/2020/02000/The_Introduction_of_a_Preoperative_MRI_Protocol.21.aspx

Pages