Department of Orthopaedic Surgery

Dr HEY Hwee Weng Dennis


Academic Appointment:

  • Clinical Senior Lecturer
    Department of Orthopaedic Surgery
    Yong Loo Lin School of Medicine
    National University of Singapore


Clinical Appointment:

  • Consultant
    University Spine Centre
    University Orthopaedics, Hand & Reconstructive Microsurgery Cluster
    National University Health System, Singapore



  • M.B.B.S., National University of Singapore (Singapore)
  • M.R.C.S., Royal College of Surgeons in Ireland (Ireland)
  • M.Med (Orth), National University of Singapore (Singapore)
  • M.C.I., National University of Singapore (Singapore)
  • F.R.C.S (Orth), Royal College of Surgeons of Edinburgh (Edinburgh)
  • F.A.M.S., Academy Medicine of Singapore (Singapore)
  • Fellowship Accreditation (Spine Surgery) Hokkaido, Japan
    • Sapporo Orthopaedic Hospital - Center for Spinal Disorders
    • Hokkaido Medical Center
    • Hokkaido Chuo Rosai Hospital – Spinal Cord Injury Center
    • Hokkaido Orthopaedic Memorial Hospital
    • Eniwa Hospital
  • Fellowship Accreditation (Spine Surgery) Seoul - Seongnam, South Korea
    • Kyung Hee University Hospital at Gangdong
    • Kyung Hee University Medical Center (Dongdaemun-gu)
    • Seoul National University Bundang Hospital
    • Wooridul Hospital (Gangnam-gu)
  • Fellowship Accreditation (Spine Surgery) Lyon, France
    • Centre Médico-Chirurgical de Réadaptation (CMCR) des Massues
  • • Fellowship Accreditation (Spine Surgery) Berlin - Munich - Bogen, Germany
    • Evangelisches Waldkrankenhaus Spandau (Berlin)
    • Schon Klinik Munchen Harlaching (Munich)
    • Pro-Spine, Klinik Bogen-Kreiskrankenhaus (Bogen)


Awards and Prizes

  • National Research Foundation - Ministry of Health (NRF-MOH) Healthcare Research Scholarship Award 2011
  • NUS Leadership in Acaedemic Medicine (NLAM) Mentoring Program Award 2012
  • Ministry of Health (MOH) Training Scholarship Award 2013
  • P Balasubramaniam Young Orthopaedic Investigator Award (YOIA) 2015
  • NUHS Orthopaedic Surgery Residency Program Best Teacher Award 2015
  • Ambassador to Jaipur, India (Combined Singapore and Indian Orthopaedic Association Programme) Award 2015
  • Health Manpower Development Programme (HMDP) – Academic Medicine Development Award (AMDA) 2016 - 2017
  • Japan Orthopaedics Traumatology Research Foundation (JOTRF) Travelling Fellowship Award 2017
  • Combined Asia Pacific Spine Society (APSS) - Société Internationale de Chirurgie Orthopédique et de Traumatologie (SICOT) Fellowship Award 2017
  • Ambassador to Hongkong (Combined Singapore and Hongkong Orthopaedic Association Programme) Award 2017
  • National Medical Research Council – Individual Research Grant - New Investigators Grant (NMRC-IRG-NIG) Award 2017-2019


Research Areas of Interests

  • Complex Spinal Instrumentation and Deformity Correction
    • Ideal Deformity Correction Targets
    • Optimal Deformity Reduction Techniques
  • Motion Preserving Spinal Reconstruction
    • Mobility of the Native and Instrumented Spine
    • Motion Analysis of the Normal and Diseased Spine
  • Minimally-Invasive Spine Surgery
    • Methods to Optimize MI Spine Surgical Techniques
    • Outcomes of MI Spine Surgery


Selected Publications

Dr. Dennis Hey's Publication List (external site)

  • The effectiveness of full body EOS compared to conventional chest X-ray in preoperative evaluation of the chest for patients undergoing spine operations - a preliminary study.
    SPINE (2018)
    Hey HWD, Chan CX, Wong YM, Sng JW, Ong HY, Tan CS, Liu KPG, Wong HK, Quek ST
  • Normal Variation in Sagittal Spinal Alignment Parameters in Adult Patients - An EOS Study Using Serial Imaging.
    European Spine Journal (2018)
    Hey HWD, Tan MKL, Moorthy V, Lau ETC, Lau LL, Liu KPG, Wong HK
  • Radiologically defining horizontal gaze using EOS® imaging - A prospective study of healthy subjects and a retrospective audit.
    The Spine Journal (2017)
    Hey HWD, Tan KA, Ho VC, Azhar S, Lim JL, Liu KPG, Wong HK
  • Using spinopelvic parameters to estimate residual lumbar lordosis assuming previous lumbosacral fusion - A study of normative values.
    The Spine Journal (2017)
    Hey HWD, Tan KA, Kantharajanna SB, Teo QA, Chan CX, Liu KPG, Wong HK
  • Supra-acetabular line is better than supra-iliac line for coronal balance referencing - A study of perioperative whole spine X-rays in degenerative lumbar scoliosis and ankylosing spondylitis patients.
    The Spine Journal (2017)
    Hey HWD, Kim CG, Lee WG, Juh HS, Kim KT
  • How are patients influenced when counselled for minimally-invasive lumbar spine surgeries? A stepwise model assessing pivotal information for decision-making.
    The Spine Journal (2017)
    Hey HWD, N Kumar, Teo QA, Tan KA, N Kumar, Liu KPG, Wong HK
  • Prevalence And Predictors of Pressure Injuries From Spine Surgery in The Prone Position - Do Body Morphological Changes During Deformity Correction Increase The Risks?
    SPINE (2017)
    Hey HWD, Lin S, Lau TE, Tan KA, Thambiah JS, Lau LL, Kumar N, Liu KPG, Wong HK
  • The Predictive Value of Preoperative Health-related quality of life scores on Postoperative Patient Reported Outcome Scores in Lumbar Spine Surgery.
    Global Spine Journal (2017)
    Hey HWD, Luo N, Chin SY, Lau ET, Wang P, Kumar N, Lau LL, Ruiz JN, Thambiah JS, Liu KPG, Wong HK
  • Cervical Alignment Variations in Different Postures and Predictors of Normal Cervical Kyphosis - A New Understanding
    SPINE (2017)
    Hey HWD, Lau TE, Wong CG, Tan KA, Liu KPG, Wong HK
  • Lumbar Spine Alignment in 6 Common Postures - A ROM Analysis With Implications for Deformity Correction
    SPINE (2017)
    Hey HWD, Lau TE, Tan KA, Lim JL, Choong AW, Lau LL, Liu KPG, Wong HK
  • Reproducibility of Sagittal Radiographic Parameters in Adolescent Idiopathic Scoliosis - A Guide to Reference Values Using Serial Imaging.
    The Spine Journal (2017)
    Hey HWD, Wong GC, Chan CX, Lau LL, Kumar N, Thambiah JS, Ruiz JN, Liu KPG, Wong HK
  • T9 Versus T10 as the Upper Instrumented Vertebra for Correction of Adult Deformity - Rationale and Recommendations.
    The Spine Journal (2017)
    Hey HWD, Tan KA, Neo CS, Lau ETC, Choong DA, Lau LL, Liu KPG, Wong HK
  • Slump Sitting X-ray of The Lumbar Spine is Superior to The Conventional Flexion View in Assessing Lumbar Spine Instability.
    The Spine Journal (2016)
    Hey HWD, Lau TE, Lim JL, Choong AWD, Tan CS, Liu KP, Wong HK
  • Differences in Erect Sitting and Natural Sitting Spinal Alignment - Insights into a New Paradigm and Implications in Deformity Correction
    The Spine Journal (2016)
    Hey HWD, Wong GC, Lau TE, Tan KA, Lau LL, Liu KPG, Wong HK
  • Delayed Lymphocele Formation Following Lateral Lumbar Interbody Fusion of the Spine - A Case Report
    European Spine Journal (2016)
    Hey HWD, Wong KL, Gatam AR, Lim JL, Wong HK
  • Is Intraoperative Local Vancomycin Powder the Answer to Surgical Site Infections in Spine Surgery?
    SPINE (2016)
    Hey HWD, Thiam WD, Koh ZS, Thambiah JS, Kumar N, Lau LL, Liu KP, Wong HK
  • Spinal Implants can be Inserted in Patients with Deep Spine Infection - Results from a Large Cohort Study.
    SPINE (2016)
    Hey HWD, Ng LW, Tan CS, Fisher D, Vasudevan A, Liu KP, Thambiah JS, Kumar N, Lau LL, Wong HK, Tambyah PA
  • How the Spine Differs in Standing and in Sitting – Important Considerations for Correction of Spinal Deformity.
    The Spine Journal (2016)
    Hey HWD, Teo QA, Tan KA, Ng LW, Lau LL, Ruiz JN, Liu KP, Wong HK
  • Subsequent vertebral fractures post cement augmentation of the thoracolumbar spine. Does it correlate with level-specific bone mineral density scores?
    SPINE (2015)
    Hey HWD, Tan JH, Tan CS, Tan HM, Lau PH, Hee HT
  • Open and Minimally Invasive Transforaminal Lumbar Interbody Fusion – Comparison of Intermediate Results and Complications.
    Asian Spine Journal (2015)
    Hey HWD, Hee HT