Dr. Stephanie Pun is the Director of the Hip Preservation Program at Stanford Children's Health and Clinical Associate Professor of Orthopaedic Surgery at Stanford School of Medicine. She specializes in both open and arthroscopic treatment of complex hip disorders for children and young adults. Her areas of expertise are adult hip dysplasia, infantile developmental dysplasia of the hip (DDH), femoroacetabular impingement (FAI), acetabular labral tears, hip sports injuries, and childhood hip diseases.

After receiving her undergraduate degree from Stanford University and medical degree from UCSF School of Medicine, she then completed orthopaedic surgery residency at Stanford University and fellowship training in child & adult hip preservation surgery at Boston Children’s Hospital/Harvard Medical School.

Dr. Pun has served as faculty and presented her research findings at both national and international orthopaedic courses and research symposiums. She is an active member of the American Academy of Orthopaedic Surgeons (AAOS), Pediatric Orthopaedic Society of North America (POSNA), the Hip Preservation Society (ISHA), and is a site director for multi-center research studies through the Academic Network of Conservational Hip Outcomes Research (ANCHOR), Global Hip Dysplasia Registry (GHDR) and Slipped Longitudinal International Prospective Registry (SCFE/SLIP).

Clinical Focus

  • Child and Adult Hip Preservation Surgery
  • Hip Dysplasia
  • Periacetabular Osteotomy (PAO) for Acetabular Dysplasia, Acetabular Retroversion, Coxa Protrusio
  • Hip Arthroscopy for Femoroacetabular Impingement (FAI), Labral Tears, Hip Cartilage Defects
  • Surgical Hip Dislocation
  • Pelvic and Femoral Osteotomies
  • Slipped Capital Femoral Epiphyses
  • Pediatric Orthopedic Surgery

Academic Appointments

Administrative Appointments

  • Director, Hip Preservation Program at Stanford Children's Health (2015 - Present)

Boards, Advisory Committees, Professional Organizations

  • Diplomate, American Board of Orthopaedic Surgery (ABOS)
  • Fellow, American Academy of Orthopaedic Surgeons (AAOS)
  • Member, The Hip Preservation Society (ISHA)
  • Member, Pediatric Orthopaedic Society of North America (POSNA)
  • Member, Ruth Jackson Orthopaedic Society (RJOS)
  • Member, Western Orthopaedic Association (WOA)
  • Member, California Orthopaedic Association (COA)
  • Faculty Mentor, Stanford School of Medicine Women and Medicine

Professional Education

  • Fellowship: Boston Children's Hospital Dept of Orthopaedic Surgery (2013) MA
  • Residency: Stanford University Orthopaedic Surgery Residency (2012) CA
  • Internship: Stanford University General Surgery Residency (2008) CA
  • Fellowship, Stanford Biodesign Faculty Fellowship, Healthcare Innovation (2017)
  • Board Certification, Orthopaedic Surgery, American Board of Orthopaedic Surgery (2015)
  • Fellowship, Harvard Medical School, Child & Adult Hip Preservation Surgery (2013)
  • Residency, Stanford University, Orthopaedic Surgery (2012)
  • Internship, Stanford University, Orthopaedic Surgery (2008)
  • Medical Education, University of California San Francisco, CA (2007)
  • Undergraduate, Stanford University, CA (2003)

Community and International Work

  • Operation Rainbow



    Ongoing Project


    Opportunities for Student Involvement


Current Research and Scholarly Interests

Dr. Pun’s research interests include advancing knowledge of the dynamic pathoanatomy in hip instability and hip impingement, defining the unique anatomy of the dysplastic acetabulum, developing new surgical techniques for improving hip function, educating and advocating for hip dysplasia awareness, and clinical outcomes of hip preservation surgery.

2023-24 Courses

All Publications

  • No Delay in Age of Crawling, Standing or Walking with Pavlik Harness Treatment: A Prospective Cohort Study. The Journal of the American Academy of Orthopaedic Surgeons Stavinoha, T. J., Pun, S. Y., McGlothlin, J. D., Uzosike, M. B., Segovia, N. A., Imrie, M. N. 2023


    BACKGROUND: Pavlik harness treatment is the standard of care for developmental dysplasia of the hip in infants younger than 6 months. The effect of Pavlik harness treatment on the achievement of motor milestones has not previously been reported.METHODS: In this prospective cohort study, 35 patients were prospectively enrolled to participate and received questionnaires with sequential clinical visits monitoring treatment of their developmental dysplasia of the hip. One-sample Student t-tests assessed differences in milestone attainment age, and the Benjamini-Hochberg procedure was conducted to decrease the false discovery rate. Post hoc power analyses of each test were conducted. The age of achievement of eight early motor milestones were recorded and compared with a previously published cohort of healthy infants.RESULTS: Infants treated with a Pavlik harness achieved four early motor milestones markedly later than the reported age of achievement in a historical control group. These milestones included "roll supine" (5.3 vs. 4.5 months; P = 0.039), "roll prone" (5.7 vs. 5.0 months; P = 0.039), "sit" (6.4 vs. 5.2 months; P < 0.001), and "crawl on stomach" (7.7 vs. 6.6 months; P = 0.039). However, there was no difference in time to achievement of later motor milestones of "crawl on knees," "pull to stand," and "independent walking."CONCLUSION: Several early motor milestones were achieved at a statistically significantly later time than historical control subjects not treated in a Pavlik harness. Despite statistical significance, the small delays in early motor milestones were not thought to be clinically significant. No differences were observed in the later motor milestones, including knee crawling, standing, and independent walking. Clinicians and parents may be reassured by these findings.LEVEL OF EVIDENCE: Therapeutic Level II-prospective study.

    View details for DOI 10.5435/JAAOS-D-21-00249

    View details for PubMedID 37862341

  • Association of Hip Dysplasia With Trochlear Dysplasia in Skeletally Mature Patients. Orthopaedic journal of sports medicine Fithian, A. T., Richey, A. E., Sherman, S. L., Shea, K. G., Pun, S. Y. 2023; 11 (10): 23259671231200805


    Developmental dysplasia of the hip (DDH) and trochlear dysplasia (TD) are distinct pathologies with several important features in common. In addition to shared risk factors, both forms of dysplasia cause abnormal joint kinematics and force transmission, predisposing patients to pain, injuries to cartilage and soft tissue stabilizers, and ultimately arthritis.To evaluate for an association between hip dysplasia and TD in skeletally mature patients with symptomatic hip dysplasia.Cross-sectional study; Level of evidence, 3.A total of 48 patients with DDH who underwent periacetabular osteotomy were compared with 48 sex-matched patients who underwent hip arthroscopy for femoroacetabular impingement (FAI) between July 2014 and February 2021. All patients were skeletally mature. The Tönnis angle and lateral center-edge angle were measured on preoperative pelvis radiographs. Femoral version, trochlear depth, lateral trochlear inclination (LTI), tibial tubercle-trochlear groove distance (TTTG-d), and posterior lateral condylar angle (PLCA) were measured on preoperative magnetic resonance imaging scans of the symptomatic hip and ipsilateral knee. Continuous variables were compared between the patient groups using 2-sample t tests. Interobserver reliability was measured using the intraclass correlation coefficient.Patients with DDH demonstrated a reduced trochlear depth compared with patients with FAI (3.6 vs 4.6 mm; P < .001). There were no differences between groups in femoral anteversion, LTI, TTTG-d, or PLCA. Two (4.2%) patients with FAI and 17 (35.4%) patients with DDH had a trochlear depth <3 mm (P < .001). One (2.1%) patient with FAI and 7 (14.6%) patients with DDH had an LTI <11° (P = .027). There was no difference between groups in frequency of a convex proximal trochlea, patient-reported ipsilateral knee pain, or ipsilateral knee procedures.Patients with DDH had reduced trochlear depth compared with patients with FAI, demonstrating a higher incidence of dysplastic trochlear features that may predispose patients to patellofemoral joint disease. Further research is needed to determine whether screening at-risk patients and treating TD will help to prevent symptomatic patellofemoral disease.

    View details for DOI 10.1177/23259671231200805

    View details for PubMedID 37822419

    View details for PubMedCentralID PMC10563471

  • Acetabular labral reconstruction with medial meniscal allograft: preliminary results of a new surgical technique. European journal of orthopaedic surgery & traumatology : orthopedie traumatologie Chen, M. J., Hollyer, I., Pun, S. Y., Bellino, M. J. 2021


    PURPOSE: Reconstruction of the acetabular labrum during femoroacetabular impingement (FAI) surgery is accepted when the labrum is deficient and irreparable. Here we describe a novel technique using fresh-frozen medial meniscal allograft for labral reconstruction during surgical hip dislocation for correction of pincer FAI due to acetabular overcoverage.METHODS: The results from seven hips (six patients) that underwent this procedure with 1 year minimum follow-up, and radiographs are presented.RESULTS: Six of the seven hips had improvements in pain, hip flexion, hip abduction, and Merle d'Aubigne-Postel scores. Only one patient with pre-existing osteoarthritis underwent reoperation with conversion to total hip arthroplasty. All digastric trochanteric osteotomies healed, and there were no cases of femoral head osteonecrosis or progression of Tonnis grades.CONCLUSIONS: The medial meniscus is a morphologically and clinically suitable option for labral reconstruction and effectively restores the hip fluid seal.

    View details for DOI 10.1007/s00590-021-02986-2

    View details for PubMedID 34028622

  • What Are the Early Outcomes of True Reverse Periacetabular Osteotomy for Symptomatic Hip Overcoverage? Clinical orthopaedics and related research Pun, S. Y., Hosseinzadeh, S., Dastjerdi, R., Millis, M. B. 2020


    BACKGROUND: Acetabular overcoverage is associated with pincer-type femoroacetabular impingement (FAI). A subtype of acetabular overcoverage is caused by a deep acetabulum with a negatively tilted acetabular roof, in which acetabular reorientation may be a preferable alternative to rim trimming to uncover the femoral head. We introduced the true reverse periacetabular osteotomy (PAO) in 2003, which in contrast to an anteverting PAO, also flexes and abducts the acetabulum relative to the intact ilium to decrease anterior and lateral femoral head coverage and correct negative tilt of the acetabular roof. To our knowledge, the clinical results of the true reverse PAO have not been evaluated.QUESTIONS/PURPOSES: For a group of patients who underwent reverse PAO, (1) Do patients undergoing reverse PAO demonstrate short-term improvement in pain, function, and hip ROM, and decreased acetabular coverage, as defined by lateral and anterior center-edge angle and Tonnis angle? (2) Are there identifiable factors associated with success or adverse outcomes of reverse PAO as defined by reoperation, conversion to THA, or poor patient-reported outcome scores? (3) Are there identifiable factors associated with early complications?METHODS: Between 2003 and 2017, two surgeons carried out 49 reverse PAOs in 37 patients. Twenty-five patients had unilateral reverse PAO and 12 patients had staged, bilateral reverse PAOs. To ensure that each hip was an independent data point for statistical analysis, we chose to include in our series only the first hip in the patients who had bilateral reverse PAOs. During the study period, our general indications for this operation were symptomatic lateral and anterior acetabular overcoverage causing FAI that had failed to respond to previous conservative or surgical treatment. Thirty-seven hips in 37 patients with a median (range) age of 18 years (12 to 41; interquartile range 16-21) were included in this retrospective study at a minimum follow-up of 2 years (median 6 years; range 2 to 17). Thirty-four patients completed questionnaires, 24 patients had radiographic evaluation, and 23 patients received hip ROM clinical examination. However, seven patients had not been seen in more than 5 years. The clinical and radiographic parameters of all 37 hips that underwent reverse PAO in 37 patients from a longitudinally maintained institutional database were retrospectively studied preoperatively and postoperatively. Adverse outcomes were considered conversion to THA or a WOMAC pain score greater than 10 at least 2 years postoperatively. Patient-reported outcomes, radiographic measurements, and hip ROM were evaluated preoperatively and at most recent follow-up using a paired t-test or McNemar test, as appropriate. Linear regression analysis was used to assess for identifiable factors associated with clinical outcomes. Logistic regression analysis was used to assess for identifiable factors associated with adverse outcomes and surgical complications. All tests were two-sided, and p values less than 0.05 were considered significant.RESULTS: At a minimum of 2 years after reverse PAO, patients experienced improvement in WOMAC pain (-7 [95% CI -9 to -5]; p < 0.001), stiffness (-2 [95% CI -3 to -1]; p < 0.001), and function scores (-18 [95% CI -24 to -12]; p < 0.001) and modified Harris Hip Score (mHHS) (20 [95% CI 13 to 27]; p < 0.001). The mean postoperative hip ROM improved in internal rotation (8° [95% CI 2° to 14°]; p = 0.007). Acetabular coverage, as defined by lateral center-edge angle (LCEA), anterior center-edge angle (ACEA), and Tonnis angle, improved by -8° (95% CI -12° to -5°; p < 0.001) for LCEA, -12° (95% CI -15° to -9°; p < 0.001) for ACEA, and 9° (95% CI 6° to 13°; p < 0.001) for Tonnis angle. The postoperative severity of radiographic arthritis was associated with worse WOMAC function scores such that for each postoperative Tonnis grade, WOMAC function score increased by 12 points (95% CI 2 to 22; p = 0.03). A greater postoperative Tonnis grade was also correlated with worse mHHS, with an average decrease of 12 points (95% CI -20 to -4; p = 0.008) in mHHS for each additional Tonnis grade. Presence of a positive postoperative anterior impingement test was associated with a decrease in mHHS score at follow-up, with an average 23-point decrease in mHHS (95% CI -34 to -12; p = 0.001). Nineteen percent (7 of 37) of hips had surgery-related complications. Four hips experienced adverse outcomes at final follow-up, with two patients undergoing subsequent THA and two with a WOMAC pain score greater than 10. We found no factors associated with complications or adverse outcomes.CONCLUSION: The early clinical and radiographic results of true reverse PAO compare favorably to other surgical treatments for pincer FAI, suggesting that reverse PAO is a promising treatment for cases of pincer FAI caused by global acetabular overcoverage. However, it is a technically complex procedure that requires substantial training and preparation by a surgeon who is already familiar with standard PAO, and it must be carefully presented to patients with discussion of the potential risks and benefits. Future studies are needed to further refine the indications and to determine the long-term outcomes of reverse PAO.LEVEL OF EVIDENCE: Level IV, therapeutic study.

    View details for DOI 10.1097/CORR.0000000000001549

    View details for PubMedID 33296152

  • Is Increased Acetabular Cartilage or Fossa Size Associated With Pincer Femoroacetabular Impingement? Clinical orthopaedics and related research Pun, S. Y., Hingsammer, A., Millis, M. B., Kim, Y. 2017; 475 (4): 1013-1023


    Surgical treatment for pincer femoroacetabular impingement (FAI) of the hip remains controversial, between trimming the prominent acetabular rim and reverse periacetabular osteotomy (PAO) that reorients the acetabulum. However, rim trimming may decrease articular surface size to a critical threshold where increased joint contact forces lead to joint degeneration. Therefore, knowledge of how much acetabular articular cartilage is available for resection is important when evaluating between the two surgical options. In addition, it remains unclear whether the acetabulum rim in pincer FAI is a prominent rim because of increased cartilage size or increased fossa size.We used reformatted MR and CT data to establish linear length dimensions of the lunate cartilage and cotyloid fossa in normal, dysplastic, and deep acetabula.We reviewed the last 200 hips undergoing PAO, reverse PAO, and surgical dislocation for acetabular rim trimming at one institution. We compared MR images of symptomatic hips with acetabular dysplasia (20 hips), pincer FAI (29 hips), and CT scans of asymptomatic hips from patients who underwent CT scans for reasons other than hip pain (20 hips). These hips were chosen sequentially from the underlying pool of 200 potential subjects to identify the first 10 male and the first 10 female hips in each group that met inclusion criteria. As a result of low numbers, we included all hips that had undergone reverse PAO and met inclusion criteria. Cartilage width was measured medially from the cotyloid fossa to the lateral labrochondral junction. Cotyloid fossa linear height was measured from superior to inferior and cotyloid fossa width was measured from anterior to posterior. Superior lunate cartilage width (SLCW) and cotyloid fossa height (CFH) were measured on MR and CT oblique coronal reformats; anterior lunate cartilage width (ALCW), posterior lunate cartilage width (PLCW), and cotyloid fossa width (CFW) were measured on MR and CT oblique axial reformats. Cohorts were compared using multivariate analysis of variance with Bonferroni's adjustment for multiple comparisons.Compared with control acetabula, dysplastic acetabula had smaller SLCW (2.08 ± 0.29 mm versus 2.63 ± 0.42 mm, mean difference = -0.55 mm; 95% confidence interval [CI] = -0.83 to -0.27; p < 0.01), ALCW (1.20 ± 0.34 mm versus 1.64 ± 0.21 mm, mean difference = -0.44 mm; 95% CI = -0.70 to -0.18; p = 0.00), CFH (2.84 ± 0.37 mm versus 3.42 ± 0.57 mm, mean difference = -0.59 mm; 95% CI = -0.96 to -0.21; p < 0.01), and CFW (1.98 ± 0.50 mm versus 2.77 ± 0.33 mm, mean difference = -0.80 mm; 95% CI = -1.16 to -0.42; p < 0.0001). Based on the results, we identified two subtypes of deep acetabula. Compared with controls, deep subtype 1 had normal CFH and CFW but increased ALCW (2.09 ± 0.42 mm versus 1.64 ± 0.21 mm; p < 0.001) and PLCW (2.32 ± 0.36 mm versus 2.00 ± 0.32 mm; p = 0.04). Compared with controls, deep subtype 2 had increased CFH (4.37 ± 0.51 mm versus 3.42 ± 0.57 mm; p < 0.01) and CFW (2.76 ± 0.54 mm versus 2.77 ± 0.33 mm; p = 1.0) but smaller SCLW (2.12 ± 0.40 mm versus 2.63 ± 0.42 mm; p < 0.01).Deep acetabula have two distinct morphologies: subtype 1 with increased anterior and posterior cartilage lengths and subtype 2 with a larger fossa in height and width and smaller superior cartilage length.In patients with deep subtype 1 hips that have increased anterior and posterior cartilage widths, rim trimming to create an articular surface of normal size may be reasonable. However, for patients with deep subtype 2 hips that have large fossas but do not have increased cartilage widths, we propose that a reverse PAO that reorients yet preserves the size of the articular surface may be more promising. However, these theories will need to be validated in well-controlled clinical studies.

    View details for DOI 10.1007/s11999-016-5063-1

    View details for PubMedID 27637612

  • Hip dysplasia in the young adult caused by residual childhood and adolescent-onset dysplasia. Current reviews in musculoskeletal medicine Pun, S. 2016; 9 (4): 427-434


    Hip dysplasia is a treatable developmental disorder that presents early in life but if neglected can lead to chronic disability due to pain, decreased function, and early osteoarthritis. The main causes of hip dysplasia in the young adult are residual childhood developmental dysplasia of the hip (DDH) and adolescent-onset acetabular dysplasia. These two distinct disease processes affect the growing hip during different times of development but result in a similar deformity and pathomechanism of hip degeneration. Routine screening for DDH and counseling regarding risks for acetabular dysplasia in families with a history of early hip osteoarthritis may allow early identification and intervention in these hips with anatomical risk factors for joint degeneration.

    View details for PubMedID 27613709

  • Review: femoroacetabular impingement. Arthritis & rheumatology Pun, S., Kumar, D., Lane, N. E. 2015; 67 (1): 17-27

    View details for DOI 10.1002/art.38887

    View details for PubMedID 25308887

    View details for PubMedCentralID PMC4280287

  • Nonarthroplasty Hip Surgery for Early Osteoarthritis RHEUMATIC DISEASE CLINICS OF NORTH AMERICA Pun, S. Y., O'Donnell, J. M., Kim, Y. 2013; 39 (1): 189-?


    The most favorable mechanical environment for the hip is one that is free of both instability and impingement, creating a concentric articulation with optimum femoral head coverage by the acetabulum. Anatomic variations such as acetabular dysplasia with associated instability, and femoroacetabular impingement with abnormal constraint, will lead to abnormal joint mechanics, articular damage, and osteoarthritis. Surgical techniques such as periacetabular osteotomies, and femoral and acetabular osteoplasties enable correction of anatomic variations that cause mechanical damage to the hip joint, thereby potentially preventing or delaying development of osteoarthritis and subsequent need for joint replacement.

    View details for DOI 10.1016/j.rdc.2012.11.004

    View details for Web of Science ID 000315170300011

    View details for PubMedID 23312416

  • Reply to Letter to the Editor: Increased Prevalence of Breast and All-cause Cancer in Female Orthopaedic Surgeons. Journal of the American Academy of Orthopaedic Surgeons. Global research & reviews Chou, L. B., Johnson, B., Shapiro, L. M., Pun, S., Cannada, L. K., Chen, A. F., Valone, L. C., Van Nortwick, S. S., Ladd, A. L., Finlay, A. K. 2023; 7 (9)

    View details for DOI 10.5435/JAAOSGlobal-D-23-00130

    View details for PubMedID 37678820

    View details for PubMedCentralID PMC10484368

  • Preliminary study on the stabilization of varus proximal femoral osteotomies using pediatric LCP plates in adults undergoing combined correction of proximal femoral and acetabular dysplasia. European journal of orthopaedic surgery & traumatology : orthopedie traumatologie Hollyer, I., Johnson, T. R., Wadwa, H., Chen, M. J., Pun, S. Y., Bellino, M. J. 2023


    PURPOSE: Proximal femoral osteotomy (PFO) with periacetabular osteotomy (PAO) improves femoral head coverage in patients with proximal femoral and acetabular dysplasia. Historically, blade plates used in the PFO cause soft-tissue irritation and often lead to implant removal. Here we present a technique using a lower profile pediatric proximal femoral locking compression plate (LCP) for the PFO in a series of adults.METHODS: The results from 13 hips in 11 patients≥18years old (age 18-37) with>10months of follow-up are presented.RESULTS: All patients had improved radiographic parameters, pain, and total Merle d'Aubigne-Postel scores postoperatively. Eleven hips (85%) had the LCP removed an average of 15.8±8.6months postoperatively, often due to pain over the greater trochanter.CONCLUSION: The pediatric proximal femoral LCP is effective for PFO in combined PAO PFO procedures but has a high rate of lateral hip discomfort leading to implant removal.

    View details for DOI 10.1007/s00590-023-03640-9

    View details for PubMedID 37428226

  • Combining Shelf Osteotomy With Proximal Femoral Reconstruction After Oncologic Resection TECHNIQUES IN ORTHOPAEDICS Zhou, J. Y., Lai, C., Pun, S. Y., Richey, A., Leshikar, H. B., Avedian, R., Steffner, R. 2023; 38 (2): 85-89
  • Increased Prevalence of Breast and All-cause Cancer in Female Orthopaedic Surgeons JOURNAL OF THE AMERICAN ACADEMY OF ORTHOPAEDIC SURGEONS GLOBAL RESEARCH AND REVIEWS Chou, L. B., Johnson, B., Shapiro, L. M., Pun, S., Cannada, L. K., Chen, A. F., Valone, L. C., Van Nortwick, S. S., Ladd, A. L., Finlay, A. K. 2022; 6 (5)
  • Increased Prevalence of Breast and All-cause Cancer in Female Orthopaedic Surgeons. Journal of the American Academy of Orthopaedic Surgeons. Global research & reviews Chou, L. B., Johnson, B., Shapiro, L. M., Pun, S., Cannada, L. K., Chen, A. F., Valone, L. C., Van Nortwick, S. S., Ladd, A. L., Finlay, A. K. 2022; 6 (5)


    INTRODUCTION: Cancer is the second leading cause of death among women in the United States. Previous studies demonstrate a higher prevalence of cancer among female orthopaedic surgeons. This study aimed to provide an updated prevalence of breast and all-cause cancer among female orthopaedic surgeons using a larger and more current study population.METHODS: We distributed surveys to female orthopaedic surgeons in national orthopaedic specialty societies. Six hundred seventy-two survey responses were collected. We calculated standardized prevalence ratios (SPRs) and 95% confidence intervals (CIs) based on gender-specific, race-specific, and age-specific cancer prevalence statistics in the US population. We compared the distribution of breast cancer risk factors with that of women in the 2018 and 2009 California Health Interview Survey.RESULTS: Fifty-one of the 672 surveyed surgeons reported a diagnosis of invasive cancer. Twenty reported breast cancer with a prevalence higher among female orthopaedic surgeons compared with the US female population (SPR: 2.89, 95% CI: 2.16 to 3.81, P < 0.001). The breast cancer prevalence was also higher among orthopaedic surgeons compared with the US female population (SPR: 3.97, 95% CI: 2.43 to 6.14, P = 0.003).DISCUSSION: The increased prevalence of breast and all-cause cancer among a larger and more diverse cohort of female orthopaedic surgeons confirms previous studies and provides an update regarding a concerning public health issue within this specialty.

    View details for DOI e22.00031

    View details for PubMedID 35587823

  • CORR Insights: Medialization of the Hip's Center with Periacetabular Osteotomy: Validation of Assessment with Plain Radiographs. Clinical orthopaedics and related research Pun, S. Y. 2021

    View details for DOI 10.1097/CORR.0000000000001657

    View details for PubMedID 33587495

  • An anatomic classification for heterotopic ossification about the hip. Journal of orthopaedics DeBaun, M. R., Ziino, C. n., LaPrade, C. n., Pun, S. n., Avedian, R. S., Bellino, M. J. 2020; 21: 228–31


    Retrospective cohort.Heterotopic ossification (HO) about the hip is a debilitating condition that can occur after fixation for acetabular fractures, total hip replacement, or polytrauma with closed head injuries. No classification exists that informs surgical treatment.To establish a classification system for HO about the hip by reviewing a consecutive series of HO at a single institution. It was hypothesized that HO about the hip could be grouped into a novel classification scheme based upon the location and involved structures of the hip.Retrospective chart review of single center's case log for HO excision from 2004 to 2018 was performed. Inclusion criteria included all patients undergoing excision of heterotopic bone excision about the hip. Demographic data, pre and post hip range of motion, surgical approach for each surgery, index surgery date and interval to excision are reported as well as presence and location of HO and Brooker classification.A total of 36 patients (21 men and 15 women) and 40 hips were identified meeting inclusion criteria. The mean age at the time of the index surgery was 47 (range, 16-77 years). Traumatic injury with fracture (35%) included 9 acetabular fractures (22%), 2 long bone fractures (5%) treated with intramedullary devices, one displaced femoral neck fracture (2%), and one pelvic ring injury (2%). Total hip arthroplasty accounted for 32% of patients. Brooker classification was type 4 (35%), 3 (25%), 2 (23%), 1(17%) which translated to 55% anterior, 48% posterior, 3% medial with respect to location. Average improvement in hip flexion and abduction was 22 and 8°, respectively.This study identified discrete locations for heterotopic ossification following hip or acetabulum surgery. Both posterior and anterior structures are implicated in the formation of HO, and this investigation presents a novel classification to guide surgical approach for HO excision based upon location.

    View details for DOI 10.1016/j.jor.2020.03.038

    View details for PubMedID 32273662

    View details for PubMedCentralID PMC7132042

  • Successful directional thoracic erector spinae plane block after failed lumbar plexus block in hip joint and proximal femur surgery JOURNAL OF CLINICAL ANESTHESIA Darling, C. E., Pun, S. Y., Caruso, T. J., Tsui, B. H. 2018; 49: 1–2
  • Successful directional thoracic erector spinae plane block after failed lumbar plexus block in hip joint and proximal femur surgery. Journal of clinical anesthesia Darling, C. E., Pun, S. Y., Caruso, T. J., Tsui, B. C. 2018; 49: 1–2

    View details for PubMedID 29775780

  • Periacetabular Osteotomy to Uncover the Hip: Uncommon Variations on a Common Procedure Pun, S., Merz, M., Bowen, G. S., Hingsammer, A., Yen, Y., Kim, Y., Millis, M. AMER ACAD PEDIATRICS. 2018
  • CORR Insights(®): The 2015 Frank Stinchfield Award: Radiographic Abnormalities Common in Senior Athletes With Well-functioning Hips but Not Associated With Osteoarthritis. Clinical orthopaedics and related research Pun, S. Y. 2016; 474 (2): 353-356

    View details for DOI 10.1007/s11999-015-4454-z

    View details for PubMedID 26178757

    View details for PubMedCentralID PMC4709321

  • Reconstruction of Lateral and Medial Elbow Ligaments for Chronic Instability Using a Single Graft With Hybrid Fixation: A New Technique of Reconstruction TECHNIQUES IN SHOULDER AND ELBOW SURGERY Pun, S. Y., Safran, M. R. 2012; 13 (1): 6–10
  • Reconstruction of both the medial and lateral collateral ligaments in the elbow using a single graft: a new technique of reconstruction. Techniques in Shoulder & Elbow Surgery Pun, S. Y., Safran, M. R. 2012; 13 (1): 6-10
  • Effect of bupivacaine on chondrocyte viability. spine journal Dragoo, J. L., Pun, S. Y. 2010; 10 (2): 172-173

    View details for DOI 10.1016/j.spinee.2009.11.015

    View details for PubMedID 20142073

  • Effect of Gender and Preoperative Diagnosis on Results of Revision Total Knee Arthroplasty Open Scientific Meeting of the Knee-Society Pun, S. Y., Ries, M. D. SPRINGER. 2008: 2701–5


    Recent studies question an effect of gender on outcome of primary TKA. We questioned whether the results of revision TKA were affected by gender. We separated 67 revision TKAs by gender and preoperative diagnosis into four groups (arthrofibrosis, infection, instability, and wear and loosening). Each revision TKA was individually matched by age and gender to two primary TKAs. Postoperative Knee Society pain and function scores after revision TKA were lower than for primary TKA for both females and males. However, postoperative Knee Society pain and function scores were similar in males and females. Postoperative pain and function scores were lower for all revision groups compared with primary TKA, except for pain and function scores after revision for instability. Postoperative pain and function scores were higher for instability and wear or loosening than for arthrofibrosis. Our data suggest the results of revision TKA are affected by preoperative diagnosis but not gender.Level III, retrospective matched cohort study. See Guidelines for Authors for a complete description of levels of evidence.

    View details for DOI 10.1007/s11999-008-0451-9

    View details for Web of Science ID 000259909000021

    View details for PubMedID 18726656

    View details for PubMedCentralID PMC2565035

  • Periodic rewetting enhances the viability of chondrocytes in human articular cartilage exposed to air JOURNAL OF BONE AND JOINT SURGERY-BRITISH VOLUME Pun, S. Y., Teng, M. S., Kim, H. T. 2006; 88B (11): 1528-1532


    Desiccation of articular cartilage during surgery is often unavoidable and may result in the death of chondrocytes, with subsequent joint degeneration. This study was undertaken to determine the extent of chondrocyte death caused by exposure to air and to ascertain whether regular rewetting of cartilage could decrease cell death. Macroscopically normal human cartilage was exposed to air for 0, 30, 60 or 120 minutes. Selected samples were wetted in lactated Ringer's solution for ten seconds every ten or 20 minutes. The viability of chondrocytes was measured after three days by Live/Dead staining. Chondrocyte death correlated with the length of exposure to air and the depth of the cartilage. Drying for 120 minutes caused extensive cell death mainly in the superficial 500 microm of cartilage. Rewetting every ten or 20 minutes significantly decreased cell death. The superficial zone is most susceptible to desiccation. Loss of superficial chondrocytes likely decreases the production of essential lubricating glycoproteins and contributes to subsequent degeneration. Frequent wetting of cartilage during arthrotomy is therefore essential.

    View details for DOI 10.1302/0301-620X.88B11.18091

    View details for Web of Science ID 000242303100023

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