Clinical Focus

  • pediatric orthopaedic surgery
  • pediatric spinal disorders
  • Hip Dislocation, Congenital
  • Scoliosis
  • Cerebral Palsy
  • Clubfoot
  • pediatric orthopaedic trauma
  • Pediatric Orthopedic Surgery

Academic Appointments

Administrative Appointments

  • Pediatric orthopaedics representative, Stanford Trauma quality assurance (2009 - Present)

Honors & Awards

  • Lena Sefton Clark Award, Rady Children's Hospital (2009-2010)

Professional Education

  • Medical Education: University of California San Diego School of Medicine (2003) CA
  • Fellowship: The Univ of San Diego School of Medicine (2009) CA
  • Board Certification: American Board of Orthopaedic Surgery, Orthopaedic Surgery (2011)
  • Residency: Stanford Hospital and Clinics - Dept of Orthopaedics (2008) CA
  • Internship: Stanford Hospital and Clinics - Dept of Surgery (2004) CA

All Publications

  • Better Patient Care Through Physician Extenders and Advanced Practice Providers. Journal of pediatric orthopedics Milewski, M. D., Coene, R. P., Flynn, J. M., Imrie, M. N., Annabell, L., Shore, B. J., Dekis, J. C., Sink, E. L. 2022; 42 (Suppl 1): S18-S24


    Physician extenders and advanced practice providers (APPs) are now common in most adult and pediatric orthopaedic clinics and practices. Their utilization, with physician leadership, can improve patient care, patient satisfaction, and physician satisfaction and work/life balance in addition to having financial benefits. Physician extenders can include scribes, certified athletic trainers, and registered nurses, while APPs include nurse practitioners and physician assistants/associates. Different pediatric orthopaedic practices or divisions within a department might benefit from different physician extenders or APPs based on particular skill sets and licensed abilities. This article will review each of the physician extender and APP health care professionals regarding their training, salaries, background, specific skill sets, and scope of practice. While other physician extenders such as medical assistants, cast technicians, and orthotists/prosthetists have important roles in day-to-day clinical care, they will not be reviewed in this article. In addition, medical trainees, including medical students, residents, fellows, and APP students, have a unique position within some academic clinics but will also not be reviewed in this article. With the many different local, state, and national regulations, a careful understanding of the physician extender and APP roles will help clinicians optimize their ability to improve patient care.

    View details for DOI 10.1097/BPO.0000000000002125

    View details for PubMedID 35405696

  • An Update on the Accessibility and Quality of Online Information for Pediatric Orthopaedic Surgery Fellowships CUREUS Cohen, S. A., Imrie, M., Shea, K. 2021; 13 (9)
  • An Update on the Accessibility and Quality of Online Information for Pediatric Orthopaedic Surgery Fellowships. Cureus Cohen, S. A., Shea, K., Imrie, M. 2021; 13 (9): e17802


    Introduction The internet is an important tool for applicants seeking information on pediatric orthopaedic surgery fellowship programs. Previous analysis of pediatric orthopaedic surgery fellowship websites demonstrated they were often inaccessible and incomplete. As such, the purpose of this study was to (1) perform an updated assessment of the accessibility and content of pediatric orthopaedic fellowship program websites and (2) compare the results to the previous study to discern temporal trends in website accessibility and quality.  Methods A list of pediatric orthopaedic fellowship programs was compiled from the San Francisco Match (SF Match) and the Pediatric Orthopaedic Society of North America (POSNA) online databases. All identified websites were evaluated for (1) accessibility and (2) the presence of 12 education and 12 recruitment criteria. These criteria were determined by prior fellowship website analyses and the needs of current fellowship applicants. Website accessibility and quality were compared with previously reported metrics. Results Approximately 91% of pediatric orthopaedic surgery fellowship programs had a functioning website. While the SF Match and POSNA databases listed nearly identical programs, there were discrepancies in the information provided by the two databases, and individual program website links provided on both databases were often nonfunctional. Fellowship program websites contained an average of 15.1 ± 3.9 total education and recruitment criteria (range: 3 - 21). The most common education criteria featured on program websites included information about research, affiliated hospital information, and rotations. The most common recruitment criteria featured on program websites included program descriptions, contact information, and social media links. There was an increased frequency in nearly all education and recruitment criteria evaluated when compared with 2014 metrics.  Discussion Although website accessibility and content have improved since 2014, information on pediatric orthopaedic fellowship program websites remains incomplete, with many websites failing to provide information on criteria deemed important by fellowship applicants. In addition, many discrepancies exist between the SF Match and POSNA databases, the two primary sources of information for pediatric orthopaedic fellowship applicants. Increased consistency on pediatric orthopaedic fellowship websites and both the SF Match and POSNA databases may help applicants to better assess which programs to apply to and which programs to rank highly on their match list.

    View details for DOI 10.7759/cureus.17802

    View details for PubMedID 34660012

    View details for PubMedCentralID PMC8497116

  • Health and Economic Outcomes of Posterior Spinal Fusion for Children With Neuromuscular Scoliosis. Hospital pediatrics Lin, J. L., Tawfik, D. S., Gupta, R., Imrie, M., Bendavid, E., Owens, D. K. 2020


    OBJECTIVES: Neuromuscular scoliosis (NMS) can result in severe disability. Nonoperative management minimally slows scoliosis progression, but operative management with posterior spinal fusion (PSF) carries high risks of morbidity and mortality. In this study, we compare health and economic outcomes of PSF to nonoperative management for children with NMS to identify opportunities to improve care.METHODS: We performed a cost-effectiveness analysis. Our decision analytic model included patients aged 5 to 20 years with NMS and a Cobb angle ≥50°, with a base case of 15-year-old patients. We estimated costs, life expectancy, quality-adjusted life-years (QALYs), and incremental cost-effectiveness from published literature and conducted sensitivity analyses on all model inputs.RESULTS: We estimated that PSF resulted in modestly decreased discounted life expectancy (10.8 years) but longer quality-adjusted life expectancy (4.84 QALYs) than nonoperative management (11.2 years; 3.21 QALYs). PSF costs $75400 per patient. Under base-case assumptions, PSF costs $50100 per QALY gained. Our findings were sensitive to quality of life (QoL) and life expectancy, with PSF favored if it significantly increased QoL.CONCLUSIONS: In patients with NMS, whether PSF is cost-effective depends strongly on the degree to which QoL improved, with larger improvements when NMS is the primary cause of debility, but limited data on QoL and life expectancy preclude a definitive assessment. Improved patient-centered outcome assessments are essential to understanding the effectiveness of NMS treatment alternatives. Because the degree to which PSF influences QoL substantially impacts health outcomes and varies by patient, clinicians should consider shared decision-making during PSF-related consultations.

    View details for DOI 10.1542/hpeds.2019-0153

    View details for PubMedID 32079619

  • Day of the Week of Surgery Affects Time to Discharge for Patients With Adolescent Idiopathic Scoliosis ORTHOPEDICS Tileston, K. R., Uzosike, M., Segovia, N., Rinsky, L. A., Imrie, M. N. 2020; 43 (1): 8–12


    Unnecessary delays in discharge are extraordinarily common in the current US health care system. These delays are even more protracted for patients undergoing orthopedic procedures. A traditional hospital staffing model is heavily weighted toward increased resources on weekdays and minimal coverage on the weekend. This study examined the effect of this traditional staffing model on time to discharge for patients undergoing posterior spinal instrumentation and fusion for adolescent idiopathic scoliosis. Patients undergoing surgery later in the week had a significantly longer hospital stay compared with patients undergoing surgery early in the week (5.5 days vs 4.9 days, respectively; P=.003). This discrepancy resulted in a mean cost increase of $7749.50 for patients undergoing surgery later in the week. A subsequent quality, safety, value initiative (QSVI) was undertaken to balance physical therapy resources alone. Following the QSVI, patients undergoing surgery later in the week had a decreased mean length of stay of 3.78 days (P=.002). Patients undergoing fusion early in the week also had a decreased mean length of stay of 3.66 days (P<.001). There was no longer a significant difference in length of stay between the "early" and the "late" groups (P=.84). This study demonstrates that simply having surgery later in the week in a hospital with a traditional staffing model adversely affects the timing of discharge, resulting in a significantly longer and more costly hospital course. By increasing physical therapy availability on the weekend, the length of stay and the cost of hospitalization decrease precipitously for these patients. [Orthopedics. 2020; 43(1);8-12.].

    View details for DOI 10.3928/01477447-20191001-06

    View details for Web of Science ID 000508434100012

    View details for PubMedID 31587077

  • Treatment in a Nonpediatric Hospital Is a Risk Factor for Open Reduction of Pediatric Supracondylar Humerus Fractures: A Population-Based Study. Journal of orthopaedic trauma Vorhies, J. S., Uzosike, O. B., Imrie, M. N., Rinsky, L. n., Hoffinger, S. n. 2019; 33 (9): e331–e338


    To describe the distribution of open versus closed treatment and its relationship with the location of care in pediatric specialty versus general hospitals.Patient data were extracted from the Healthcare Cost and Utilization Project's Kid's Inpatient Database for the years 2000-2012. ICD9-CM diagnosis and procedure codes were used to identify open versus closed treatment of closed supracondylar humerus fractures in children younger than 12 years. A multilevel logistic regression model to control for confounders and identify drivers of open treatment was used.An estimated 40,706 inpatient surgical fixation procedures met our inclusion criteria. Overall rate of open treatment was 13.65%. Fractures were less likely to be treated open at pediatric hospitals versus general hospitals 7.61% versus 16.13% (P < 0.0001). Over the study period, rates of open treatment have fallen at nonpediatric hospitals from 20.21% in 2000 to 17.42% in 2012 (P < 0.001) but have remained stable at pediatric hospitals: 7.8% in 2000 and 8.62% in 2012 (P = 0.4369). Mean hospital length of stay was higher for patients who had open treatment 1.63 versus 1.20 days (P < 0.0001), and mean hospital charges were higher for patients who had open treatment $21,465 versus $15,026 (P < 0.0001). After controlling for time trends as well as demographic and hospital characteristics with a logistic regression model, treatment at a nonpediatric hospital was the single most significant predictor of open treatment for an isolated closed supracondylar humerus fractures with an odds ratio of 1.96 (95% confidence interval 1.56-2.46; P < 0.001).In this comprehensive population-based study of risk factors for open treatment of supracondylar humerus fractures in the United States, we identified differences in practice patterns by hospital type. Pediatric supracondylar fractures of the elbow have almost twice the odds of open treatment at nonpediatric hospitals.Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

    View details for DOI 10.1097/BOT.0000000000001502

    View details for PubMedID 31188255

  • Trans-metaphyseal Screws Placed in Children: An Argument for Monitoring and Potentially Removing the Implants. Journal of pediatric orthopedics Gamble, J. G., Zino, C., Imrie, M. N., Young, J. L. 2018


    BACKGROUND: Surgeons frequently use trans-metaphyseal screws in children to achieve osteosynthesis after fractures or stability after reconstructive osteotomies. Screws that were initially inserted below the cortex of bone can become prominent and symptomatic due to the process of funnelization that narrows the wide metaphysis to the diameter of the thinner diaphysis.METHODS: Case series presentation of 11 children who presented with screw prominence after the cutback process range in age from 19 to 169 months. We used the screws as radiographic markers to quantitate the amount of bone "cutback" or lost during the process of funnelization.RESULTS: The average length of screw protrusion beyond the edge of the bone when symptomatic was 8.7mm (range, 3.3 to 14.3mm). Time from implantation to the last radiograph averaged 40 months (range, 19 to 84mo). The average loss of bone width at the time of presentation was 21% (range, 7% to 36%).CONCLUSIONS: These cases suggest that orthopaedic surgeons should consider monitoring children after implantation of trans-metaphyseal screws and informing parents and patients about the possibility of screw prominence necessitating removal due to the process of metaphyseal funnelization.LEVEL OF EVIDENCE: Level IV.

    View details for DOI 10.1097/BPO.0000000000001280

    View details for PubMedID 30379707

  • Endoscopic-assisted epiphysiodesis: technique and 20-year experience. Journal of pediatric orthopedics. Part B Ledesma, J. B., Wang, T., Desmond, E., Imrie, M., Gamble, J. G., Rinsky, L. A. 2016; 25 (1): 24-30


    The aim of the study was to describe the endoscopic-assisted epiphysiodesis technique and review our 20-year experience with it. A retrospective review of 44 patients who underwent proximal tibia and/or distal femur endoscopic-assisted epiphysiodesis was carried out. Only patients who had preoperative and postoperative scanograms with clinical follow-up of at least 6 months were included. The mean length of follow-up was 36.8 months. All patients had radiographic evidence of physeal fusion within 6-12 months from the index procedure. No patient required revision surgery. Endoscopic-assisted epiphysiodesis is safe, effective, and achieves predictable physeal fusion. Advantages over current techniques include reduced radiation exposure and lack of requirement for hardware placement.

    View details for DOI 10.1097/BPB.0000000000000230

    View details for PubMedID 26462167

  • Getting there--working toward minimizing blood loss in scoliosis surgery. spine journal Imrie, M. N. 2015; 15 (6): 1223-1224


    Ryan KM, O'Brien K, Reqan I, O'Byrne JM, Moore D, Kelly PM, et al. The prevalence of abnormal preoperative coagulation tests in pediatric patients undergoing spinal surgery for scoliosis. Spine J 2015;15:1217-22 (in this issue).

    View details for DOI 10.1016/j.spinee.2015.03.044

    View details for PubMedID 26001884

  • Commentary: True blood-changes in blood management in pediatric deformity surgery SPINE JOURNAL Imrie, M. N. 2012; 12 (6): 463-465

    View details for DOI 10.1016/j.spinee.2012.06.013

    View details for Web of Science ID 000307251200005

    View details for PubMedID 22857645

  • A "simple'' option in the surgical treatment of congenital scoliosis SPINE JOURNAL Imrie, M. N. 2011; 11 (2): 119-121


    Commentary on: Li X-F, Liu Z-D, Hu G-Y, et al. Posterior unilateral pedicle subtraction osteotomy of hemivertebra for correction of the adolescent congenital spinal deformity. Spine J 2011;11:111-118 (in this issue).

    View details for DOI 10.1016/j.spinee.2010.12.007

    View details for Web of Science ID 000286980400012

    View details for PubMedID 21296294

  • Adolescent Idiopathic Scoliosis: Should 100% Correction Be the Goal? JOURNAL OF PEDIATRIC ORTHOPAEDICS Imrie, M., Yaszay, B., Bastrom, T. P., Wenger, D. R., Newton, P. O. 2011; 31: S9-S13


    What constitutes optimal thoracic curve scoliosis correction is controversial. The development and application of powerful pedicle screw-aided instrumentation constructs has, in some cases, led to hypercorrection of the thoracic scoliosis with resulting coronal imbalance, trunk shift, and shoulder imbalance. The purpose of this study was to compare the clinical and radiographic outcomes between Lenke 1 patients with the highest and lowest degree of correction to assess this risk. Our hypothesis was that greater scoliosis curve correction can be done without producing secondary decompensation.Using a prospective AIS database, Lenke 1 curves, with 2-year follow-up (n=385) were ranked by percent coronal correction. The top 15% or high correction group (>80% coronal correction) were compared with the bottom 15% or low correction group (< 40% coronal correction). Clinical and radiographic outcomes, including parameters of coronal and sagittal balance, were compared using ANOVA and χ tests (P ≤ 0.007).The high correction group (n=39) and the low correction group (n=40) did not differ preoperatively except in lumbar flexibility. In the coronal plane, the high correction group did not show postoperative clinical imbalance (trunk shift and shoulder height) and had better radiographic balance (C7-CSVL shift). The deformity-flexibility quotient (DFQ), which is the ratio of residual lumbar curve to remaining unfused lumbar segments, was lower (optimal) in the high correction group. The residual rib hump was also better. In the sagittal plane, the high correction group had less kyphosis secondary to a loss of kyphosis compared with a gain (improvement) in the low correction group. Despite these differences, SRS scores were not different.Maximizing Lenke 1 curve correction to achieve greater lumbar correction and improved clinical appearance can be done without compromising coronal balance but may occur at the expense of sagittal alignment. However, surgeons who are learning to apply powerful new corrective methods should be cautious in trying to obtain full correction. Proper preoperative evaluation, fusion level selection, and surgical technique are needed to attain this outcome.

    View details for DOI 10.1097/BPO.0b013e3181fd8a24

    View details for Web of Science ID 000288462100002

    View details for PubMedID 21173626

  • Management of spinal deformity in cerebral palsy. Orthopedic clinics of North America Imrie, M. N., Yaszay, B. 2010; 41 (4): 531-547


    An understanding of the three-dimensional components of spinal deformity in children with cerebral palsy is necessary to recommend treatments that will positively affect these patients' quality of life. Management of these deformities can be challenging and orthopedic surgeons should be familiar with the different treatments available for this patient population. This article discusses the incidence, causes, natural history, and treatment of patients with scoliosis.

    View details for DOI 10.1016/j.ocl.2010.06.008

    View details for PubMedID 20868883

  • Management of Spinal Deformity in Cerebral Palsy ORTHOPEDIC CLINICS OF NORTH AMERICA Imrie, M. N., Yaszay, B. 2010; 41 (4): 531-?


    An understanding of the three-dimensional components of spinal deformity in children with cerebral palsy is necessary to recommend treatments that will positively affect these patients' quality of life. Management of these deformities can be challenging and orthopedic surgeons should be familiar with the different treatments available for this patient population. This article discusses the incidence, causes, natural history, and treatment of patients with scoliosis.

    View details for DOI 10.1016/j.ocl.2010.06.008

    View details for Web of Science ID 000208410900008

  • Is ultrasound screening for DDH in babies born breech sufficient? Journal of children's orthopaedics Imrie, M., Scott, V., Stearns, P., Bastrom, T., Mubarak, S. J. 2010; 4 (1): 3-8


    To review our incidence of developmental dysplasia of the hip (DDH) in breech infants referred for ultrasound screening and to determine if subsequent follow-up radiographs are necessary in these patients with normal clinical and ultrasound examinations.A review of the clinical data and imaging studies of all children with the risk factor of breech presentation that were referred for orthopedic evaluation over a 5-year period was conducted. All patients were examined by a fellowship-trained pediatric orthopedic surgeon and all ultrasounds were done at approximately 6 weeks of age by an experienced ultrasonographer. Ultrasounds were evaluated using the dynamic method as described by Harcke. As per our protocol, all patients with normal screening ultrasounds were brought back for a final clinical examination and radiographic check at 4-6 months. Acetabular dysplasia was indicated by radiographic parameters-if there was severe blunting of the sourcil, abnormal acetabular index for age, or if there was significant asymmetry of acetabular indices side-to-side-in the setting of clinical parameters-if there was greater than 10° difference in side-to-side abduction or symmetric abduction of less than 60°.Three hundred patients with the risk factor of breech presentation were included. Thirty-four patients had clinically unstable hips; 266 had clinically stable hips and were screened by ultrasound. Sixty-four percent were female and 36% were male. Twenty-seven percent of these breech patients had abnormal screening ultrasounds and were subsequently treated. Of the remaining 73% with normal ultrasounds, who were returned per protocol at a mean of 5 months, 29% had evidence of dysplasia and underwent treatment. The diagnosis of dysplasia following a normal ultrasound was based on both radiographic and clinical parameters. Of the hips treated with a Pavlik harness, 62% had acetabular indices at least two standard deviations from the age-corrected average versus 26% of patients not treated. The average length of follow-up was 10 months.Retrospectively, we found that, at approximately 6 weeks of age, ultrasound screening of breech patients with clinically stable hips produces an incidence of DDH of 27%. In those patients with a normal ultrasound, 29%, at 4-6 months radiographic follow-up, were found to have dysplasia requiring treatment. This data supports breech as the most important risk factor for hip dysplasia and we, therefore, recommend careful and longitudinal evaluation of these patients with: a careful newborn physical examination, an ultrasound at age 6 weeks, and an anteroposterior (AP) pelvis and frog lateral radiograph at 6 months, as the risk of subsequent dysplasia is too high to discharge patients after a normal ultrasound.

    View details for DOI 10.1007/s11832-009-0217-2

    View details for PubMedID 19915881