May Featured Author

Mats Brittberg, MD, PhD

Cartilage Research Unit
Institute of Clinical Sciences
University of Gothenburg
Gothenburg, Sweden

From the May issue: Matrix-Applied Characterized Autologous Cultured Chondrocytes Versus Microfracture: Five-Year Follow-up of a Prospective Randomized Trial

Podcast: Listen to Dr. Brittberg discuss his article in the May issue.


Mats Brittberg is a member of the Cartilage Research Unit at University of Gothenburg and an orthopedic surgeon at Region Halland Orthopaedics at the Kungsbacka Hospital, Kungsbacka, Sweden.  He received his MD at the University of Gothenburg in 1978 and completed a specialization in orthopedics in 1985.  In 1992 he passed the Swedish Orthopedic Board Exam (S.O.B.E.), and in 1996 he earned a PhD. He is now a professor of orthopaedics connected to the Institution of clinical sciences and orthopaedic department, University of Gothenburg.

Mats Brittberg’s research has been focused on cartilage repair and with main focus on cartilage regeneration with in vitro expanded autologous chondrocytes. Another  interest is the European Connective Tissue Engineering centre (ECTEC), which is research collaboration between the Sahlgrenska Academy at University of Gothenburg with the institution of Polymer Technology, Chalmers Technical University. Mats Brittberg has also had research collaboration with Virginia Tech in USA on biotribology in cartilage and osteoarthritis as well as research collaborations with other centers in Europe and North America.

Mats Brittberg is also co-director of the cartilage program and cartilage centre at Aspetar Orthopaedic and Sports medicine Hospital, Doha, Qatar.

In September, 2010, Mats Brittberg received the ICRS Genzyme Lifetime Achievement Award in cartilage research and in 2012, the Shetty- Kim Foundation (SKF) Scientific award. In 2014, Mats Brittberg also received the SKF and UK Cartilage Club’s Life time achievement Award.

Mats Brittberg has been on the board of TESi (Tissue engineering Society International) and has been chairing the Cartilage Committee of ESSKA 2006-08. Since the start 1997, he has been working with ICRS, as a secretary, Vice-president and President (2006-2008) and finally Past-President (2008-2009). He is since January 2013  Editor-in-Chief for the SAGE journal CARTILAGE. He has also been associate editor with ESSKA journal as well as being on the editorial board of Osteoarthritis and Cartilage. Mats Brittberg is also involved in the Go:Life platform for scientific meetings in Gothenburg and clinical adviser to several cartilage repair companies.

Selected Other Published Work in AJSM

Peterson L, Brittberg M, Kiviranta I, Akerlund EL, Lindahl A. Autologous chondrocyte transplantation. Biomechanics and long-term durability. Am J Sports Med. 2002 Jan-Feb;30(1):2-12.

Brittberg M. Cell carriers as the next generation of cell therapy for cartilage repair: a review of the matrix-induced autologous chondrocyte implantation procedure. Am J Sports Med. 2010 Jun;38(6):1259-71.

Peterson L, Vasiliadis HS, Brittberg M, Lindahl A. Autologous chondrocyte implantation: a long-term follow-up. Am J Sports Med. 2010 Jun;38(6):1117-24

de Windt TS, Welsch GH, Brittberg M, Vonk LA, Marlovits S, Trattnig S, Saris DB. Is magnetic resonance imaging reliable in predicting clinical outcome after articular cartilage repair of the knee? A systematic review and meta-analysis. Am J Sports Med. 2013 Jul;41(7):1695-702

de Windt TS, Welsch GH, Brittberg M, Vonk L, Marlovits S, Trattnig S, Saris DB, Blackman AJ, Smith MV, Flanigan DC, Matava MJ, Wright RW, Brophy RH. Correlation between magnetic resonance imaging and clinical outcomes after knee cartilage repair: letter to the editor. Am J Sports Med. 2013 Nov;41(11)

Saris D, Price A, Widuchowski W, Bertrand-Marchand M, Caron J, Drogset JO, Emans P, Podskubka A, Tsuchida A, Kili S, Levine D, Brittberg M; SUMMIT study group. Matrix-Applied Characterized Autologous Cultured Chondrocytes Versus Microfracture: Two-Year Follow-up of a Prospective Randomized Trial. Am J Sports Med. 2014 Jun;42(6):1384-94

Brittberg M, Recker D, Ilgenfritz J, Saris DBF; SUMMIT Extension Study Group. Matrix-Applied Characterized Autologous Cultured Chondrocytes Versus Microfracture: Five-Year Follow-up of a Prospective Randomized Trial. Am J Sports Med. 2018 Mar 1:363546518756976.


April Featured Author

Brian J. Cole, MD, MBA

Associate Chairman and Professor, Department of Orthopedics, Rush
Chairman, Department of Surgery, Rush OPH
Shoulder, Elbow, and Knee Surgery
Section Head, Cartilage Restoration Center at Rush
Team Physician Chicago Bulls and Chicago White Sox
Rush University Medical Center
Chicago, Illinois

From the April issue: Preoperative Tibial Subchondral Bone Marrow Lesion Patterns and Associations With Outcomes After Isolated Meniscus Allograft Transplantation

Podcast: Listen to Dr. Cole discuss his article in the April issue.


Dr. Cole is a Professor in the Department of Orthopedics with a conjoint appointment in the Department of Anatomy and Cell Biology at Rush University Medical Center in Chicago, Illinois. In 2015, he was appointed as an Associate-Chairman of the Department of Orthopedics at Rush. In 2011, he was appointed as Chairman of Surgery at Rush Oak Park Hospital. He is the Section Head of the Cartilage Research and Restoration Center at Rush specializing in the treatment of arthritis in young active patients with a focus on regenerative medicine and biologic alternatives to surgery.  He also serves as the head of the Orthopedic Master’s Training Program and trains residents and fellows in sports medicine and research. He lectures nationally and internationally and holds several leadership positions in prominent sports medicine societies. Through his basic science and clinical research, he has developed several innovative techniques for the treatment of shoulder, elbow, and knee conditions. He has published more than 1,000 articles and 10 widely read textbooks in orthopedics and regenerative medicine.

Dr. Cole has been frequently chosen as one of the “Best Doctors in America” since 2004 and as a “Top Doctor” in the Chicago metro area since 2003. In 2006, he was featured on the cover of Chicago Magazine as “Chicago’s Top Doctor” and was selected as NBA Team Physician of the Year in 2009. Orthopedics This Week has named Dr. Cole as one of the top 20 sports medicine, knee, and shoulder specialists repeatedly over the last 5 years as selected by his peers. He is the head team physician for the Chicago Bulls NBA team, co-team physician for the Chicago White Sox MLB team and DePaul University in Chicago.

Selected Other Published Work in AJSM

Cole BJ, Karas V, Hussey K, Merkow D, Pilz K, Fortier, LA. Hyaluronic Acid Versus Platelet-Rich Plasma: A Prospective, Double-Blind Randomized Controlled Trial Comparing Clinical Outcomes and Effects on Intra-articular Biology for the Treatment of Knee Osteoarthritis. Am J Sports Med. 2016 Oct; 45 (2): 339-46.

Saltzman BM, Leroux T, Meyer MA, Basques BA, Chahal J, Bach BR, Yanke AB, Cole BJThe Therapeutic Effect of Intra-Articular Normal Saline Injections for Knee Osteoarthritis: A Meta-Analysis of Evidence Level 1 StudiesAm J Sports Med. 2016 Nov.

Riboh JC, Saltzman BM, Yanke AB, Cole BJHuman amniotic membrane-derived products in sports medicine:  Basic science, early results and potential clinical applicationsAm J Sports Med, 2016 Sep; 44 (9): 2425-34.

Padaki AS, Cole BJ, Ahmad CS. Concussion Incidence and Return-to-Play Time in National Basketball Association Players: Results from 2006 to 2014Am J Sports Med. 2016 Sep; 44 (9): 2263-8.

Cole BJ, Karas V, Hussey K, Pilz K, Fortier LA. Hyaluronic Acid Versus Platelet-Rich Plasma: A Prospective, Double-Blind Randomized Controlled Trial Comparing Clinical Outcomes and Effects on Intra-articular Biology for the Treatment of Knee OsteoarthritisAm J Sports Med. 2016 Sep.

Leroux TS, Saltzman BM, Meyer M, Frank RM, Bach BR Jr, Cole BJ, Romeo AA, Verma NN. The Influence of Evidence-Based Surgical Indications and Techniques on Failure Rates After Arthroscopic Shoulder Stabilization in the Contact or Collision Athlete With Anterior Shoulder InstabilityAm J Sports Med. 2016 Aug.

Getgood A, LaPrade RF, Verdonk P, Gersoff W, Cole BJ, Spalding T; IMREF Group. International Meniscus Reconstruction Experts Forum (IMREF) 2015 Consensus Statement on the Practice of Meniscal Allograft TransplantationAm J Sports Med. 2016 Aug.

Cvetanovich GL, Riboh JC, Tilton AK, Cole BJAutologous Chondrocyte Implantation Improves Knee-Specific Functional Outcomes and Health-Related Quality of Life in Adolescent PatientsAm J Sports Med. 2016 Aug.

MARS Multicenter Group. Meniscal and Articular Cartilage Predictors of Clinical Outcome After Revision Anterior Cruciate Ligament ReconstructionAm J Sports Med. 2016 Jul.

Makhni EC, Saltzman BM, Meyer MA, Moutzouros V, Cole BJ, Romeo AA, Verma NN. Outcomes After Shoulder and Elbow Injury in Baseball Players: Are We Reporting What Matters? Am J Sports Med. 2016 Apr.

Cvetanovich GL, Chalmers PN, Verma NN, Cole BJ, Bach BR. Risk Factors for Short-term Complications of Anterior Cruciate Ligament Reconstruction in the United StatesAm J Sports Med. 2016 Jan.

March Featured Author

Yoo_Jae Chul
Jae Chul Yoo, MD
Department of Orthopedic Surgery
Sungkyunkwan University, School of Medicine
Samsung Medical Center
Seoul, Korea

From the March issue: Location of Rotator Cuff Tear Initiation: A Magnetic Resonance Imaging Study of 191 Shoulders

Podcast: Listen to Dr. Yoo discuss his article in the March issue.


Jae Chul Yoo, MD is a Professor in the Department of Orthopedic Surgery at Sungkyunkwan University, School of Medicine, Samsung Medical Center in Seoul, Korea. He also serves on the editorial board for Arthroscopy: The Journal of Arthroscopic and Related Surgery, is a reviewer for The American Journal of Sports Medicine and Journal of Shoulder and Elbow Surgery, and is the Secretary General for the Korean Shoulder and Elbow Society.

He is a member, subspecialist, and/or board member of several societies including: Korea Orthopedic Association (KOA); Korean Sports Medicine Association; Korean Shoulder and Elbow Society (KSES); Korean Arthroscopy Association (KAA); International Society of Arthroscopy, Knee Surgery, and Orthopaedic Sports Medicine (ISAKOS); Korean Orthopedic Sport Medicine Association (KOSMA); European Society of Sport traumatology Knee Surgery and Arthroscopy (ESSKA); Arthroscopy Association of North America (AANA); Magellan Society; Korean Orthopedic Ultrasonography Association; American Shoulder Elbow Society (ASES); and European Shoulder & Elbow Society (SECEC).

Selected Published Work

Evaluation of the Risk Factors for a Rotator Cuff Retear After Repair Surgery. Lee YS, Jeong JY, Park CD, Kang SG, Yoo JC. Am J Sports Med. 2017 Jul;45(8):1755-1761. doi: 10.1177/0363546517695234. Epub 2017 Mar 20. PMID: 28319431

Reversibility of Supraspinatus Muscle Atrophy in Tendon-Bone Healing After Arthroscopic Rotator Cuff Repair. Park YB, Ryu HY, Hong JH, Ko YH, Yoo JC. Am J Sports Med. 2016 Apr;44(4):981-8. doi: 10.1177/0363546515625211. Epub 2016 Feb 10. PMID: 26865396

Arthroscopic Partial Repair of Irreparable Rotator Cuff Tears: Preoperative Factors Associated With Outcome Deterioration Over 2 Years. Shon MS, Koh KH, Lim TK, Kim WJ, Kim KC, Yoo JC. Am J Sports Med 2015 43: 1965. originally published online May 26, 2015.

Arthroscopic distal clavicle resection in symptomatic acromioclavicular joint arthritis combined with rotator cuff tear: a prospective randomized trial. Park YB, Koh KH, Shon MS, Park YE, Yoo JC. Am J Sports Med. 2015 Apr;43(4):985-90. doi: 10.1177/0363546514563911. Epub 2015 Jan 12.

Preoperative factors affecting footprint coverage in rotator cuff repair. Koh KH, Lim TK, Park YE, Lee SW, Park WH, Yoo JC. Am J Sports Med. 2014 Apr;42(4):869-76. doi: 10.1177/0363546513518581. Epub 2014 Feb 4.

A Magnetic Resonance Imaging Study of 100 Cases of Arthroscopic Acromioplasty. Koh KH, Laddha MS, Lim TK, Lee JH, Yoo JC. Am J Sports Med. 2012 Feb;40(2):352-8. Epub 2011 Nov 17

Patient-related factors and complications after arthroscopic tenotomy of the long head of the biceps tendon. Lim TK, Moon ES, Koh KH, Yoo JC. Am J Sports Med. 2011 Apr; 39(4):783-9. Epub 2011 Jan 6.

Clinical and Magnetic Resonance Imaging Results of Arthroscopic Full-Layer Repair of Bursal-Side Partial-Thickness Rotator Cuff Tears. Koh KH, Shon MS, Lim TK, Yoo JC. Am J Sports Med. 2011 Aug;39(8):1660-7. Epub 2011 Jul 7. PMID: 21737830

Patient-Related Factors and Complications After Arthroscopic Tenotomy of the Long Head of the Biceps Tendon. Tae Kang Lim, MD, Eun Sun Moon,y MD, Kyoung Hwan Koh, MD, and Jae Chul Yoo, MD. Am J Sports Med. Vol. 39, No. 4, 2011.

Treatment of Biceps Tendon Lesions in the Setting of Rotator Cuff Tears Prospective Cohort Study of Tenotomy Versus Tenodesis. Kyoung Hwan Koh,MD, Jae Chul Yoo, MD, Jin Hwan Ahn, MD, and Sang Min Kim, MD. Am J Sports Med. 2010 Aug;38(8):1584-90.PMID: 20551285

Clinical Results of Single-Tunnel Coracoclavicular Ligament Reconstruction Using Autogenous Semitendinosus Tendon. Jae-Chul Yoo, Jin-Hwan Ahn, Jung-Ro Yoon and Jae-Hyuk Yang. Am J Sports Med 2010 38

Increasing Incidence of Medial Meniscal Tears in Nonoperatively Treated Anterior Cruciate Ligament Insufficiency Patients Documented by Serial Magnetic Resonance Imaging Studies. Jae Chul Yoo, MD, Jin Hwan Ahn, MD, Sang Hak Lee, MD, and Young Cheol Yoon, MD. Am J Sports Med Vol. 37, No. 8, 2009

Magnetic Resonance Image appearance of a repaired capsulolabral complex after arthroscopic Bankart repair. Jae Chul Yoo, M.D., Yong Seuk Lee, M.D., Suk Kee Tae, M.D., Jung Ho Park, M.D., Jong Woong Park, M.D., Hae Chan Ha, M.D. Am J Sports Med, Vol. 36, No. 12 2008

February Featured Author

Aaron J. Krych, MD
Program Director, Sports Medicine Fellowship
Program Director, Sports Medicine Research Fellowship
Mayo Clinic Orthopedic Surgery and Sports Medicine
Rochester, MN

From the February issue: Multicenter Analysis of Midterm Clinical Outcomes of Arthroscopic Labral Repair in the Hip: Minimum 5-Year Follow-up

Podcast: Listen to Dr. Krych discuss his article in the February issue.


Aaron Krych is Professor of Orthopedic Surgery and Sports Medicine at the Mayo Clinic in Rochester, MN, USA. He is also Director of the Orthopedic Surgery Sports Medicine Fellowship and Orthopedic Surgery Sports Medicine Research Fellowship.

He received his MD and Orthopedic Surgery Residency training at Mayo Clinic. He completed his sports fellowship training at Hospital for Special Surgery in New York in 2010. He was an ICRS Travelling Fellow in 2013. His clinical focus has been on cartilage restoration in the hip and knee, and knee osteotomy and meniscus transplant. His research interests include improving cartilage allograft, adipose-derived MSC injection for hip and knee arthritis, meniscus repair, and single stage cell-based cartilage repair.

Selected Published Work

Melugin H, Wu IT, Levy BA, Stuart MJ, Krych AJIs Treatment of Segond Fracture Necessary with Combined ACL Reconstruction?  Am J Sports Med. 2017 Dec 1:363546517745280. doi: 10.1177/0363546517745280. [Epub ahead of print] PMID: 29286825

Schilaty ND, Nagelli C, Bates NA, Sanders TL, Krych AJ, Stuart MJ, Hewett TE. Incidence of Second Anterior Cruciate Ligament Tears (2001 – 2010) and Associate Factors by Geographic LocaleOrthop J Sports Med. 2017 Aug 18;5(8):2325967117724196. doi: 10.1177/2325967117724196. eCollection 2017 Aug. PMID:28840155

Sanders TL, Christensen TC, Johnson NR, Hewett TE, Stuart MJ, Dahm DL, Krych AJIncidence of Acute Lateral Patellar Dislocation: A 21-Year Population-Based Study.  Sports Health. 2017 Aug 1:1941738117725055. doi: 10.1177/1941738117725055. [Epub ahead of print] PMID: 28795924

Schilaty ND, Bates NA, Sanders TL, Krych AJ, Stuart MJ, Hewett TE. Incidence of Second Anterior Cruciate Ligament Tears (1990 – 2000) and Associate Factors by Geographic LocaleAm J Sports Med. 2017 Jun; 45 (7):1567-1573. 2017 Mar 1:363546517694026. doi: 10.1177/0363546517694026. [Epub ahead of print] PMID: 28298067

Christensen TC, Sanders TL, Pareek A, Mohan R, Dahm DL, Krych AJRisk Factors and Time to Recurrent Ipsilateral and Contralateral Patellar Dislocation: A Population-Based Study.  Am J Sports Med. 2017 May 1:363546517704178. doi: 10.1177/0363546517704178. [Epub ahead of print] PMID:28463535.

Sanders TL, Pareek A, Obey MR, Johnson NR, Carey JL, Stuart MJ, Krych AJHigh Rate of Osteoarthritis following OCD Fragment Excision Compared to Surgical Restoration at a Mean 16-Year Follow-UpAm J Sports Med. 2017 Apr 1:363546517699846. doi: 10.1177/0363546517699846. [Epub ahead of print] PMID: 28419816

Amano K, Li A, Pedoia V, Krych AJ, Rodeo S, Li X, Ma CB, Majumdar S, AF-ACL Consortium. Surgical timing is related to changes seen in cartilage matrix composition after ACL reconstructionAm J Sports Med. 2017 Apr;45(5):1075-1084. doi: 10.1177/0363546516677794. Epub 2017 Jan 27. PMID: 28768432

Sanders TL, Pareek A, Johnson NR, Stuart MJ, Dahm DL, Krych AJPatellofemoral Arthritis after Lateral Patellar Dislocation: A Population-Based AnalysisAm J Sports Med. 2017 Apr;45(5):1012-1017. doi: 10.1177/0363546516680604 PMID: 28005405

Bryan AJ, Krych AJ, Pareek A, Reardon PJ, Berardelli R, Levy BA. Are Short-term Outcomes of Hip Arthroscopy in Patients Older than 55 Years Inferior to Younger Patients? Am J Sports Med 2016 Oct; 44 (10):2526-2530. pii: 0363546516652114. [Epub ahead of print] PMID: 27416992

Allen MM, Pareek A, Krych AJ, Hewett TE, Levy BA, Stuart MJ, Dahm DL. Are Female Soccer Players At An Increased Risk of Second Anterior Cruciate Ligament Injury Compared to Their Athletic Peers? Am J Sports Med 2016 Oct; 44 (10):2492-2498. pii: 0363546516648439. [Epub ahead of print] PMID: 27261476

Sanders T, Maradit Kremers H, Bryan A, Fruth K, Larson DR, Levy BA, Stuart MJ, Dahm DL, Krych AJ. Is ACL reconstruction effective in preventing secondary meniscal tears and osteoarthritis? Am J Sports Med 2016 Jul; 44 (7):1699-707. pii: 0363546516634325. [Epub ahead of print] PMID:26957217

Sanders T, Maradit Kremers H, Bryan A, Kremers WK, Levy BA, Dahm DL, Stuart MJ, Krych AJ. Incidence of and Factors Associated with the Decision to Undergo ACL Reconstruction One to Ten Years After InjuryAm J Sports Med. 2016 Jun;44(6):1558-64. doi: 10.1177/0363546516630751 PMID: 26928338

Sanders T, Maradit Kremers H, Bryan AJ, Larson DR, Dahm DL, Levy BA, Stuart MJ, Krych AJ. Incidence of anterior cruciate ligament tears and reconstruction: A 21 year population-based studyAm J Sports Med. 2016 Jun;44(6):1502-7. doi: 10.1177/0363546516629944 PMID: 26920430

Krych AJ, King AH, Bererdelli RL, Sousa PL, Levy BA. Is MRI Subchondral Edema with Cystic Change a contraindication for hip arthroscopy in patients with FAI?  Am J Sports Med. 2016 Feb;44(2):454-9. doi: 10.1177/0363546515612448. PMID:26620297

Krych AJ, Nawabi DH, Jones K, Farshad-Amacker NA, Maak TG, Potter HP, Williams, RJ, III. Bone Marrow Concentrate lmproves Early Scaffold Plug Cartilage Phase Maturation: A Comparative MRI AnalysisAm J Sports Med. 2016 Jan;44(1):91-8. PMID: 26574602

CL Camp, MJ Heidenreich, DL Dahm, MJ Stuart, BA Levy, Krych AJIndividualizing the Tibial Tubercle to Trochlear Groove Distance: Patellar Instability Ratios That Predict Recurrent Instability.  Am J Sports Med. 2016 Feb;44(2):393-9. doi: 10.1177/0363546515602483 PMID: 26394888

Christensen J, Krych AJ, Engasser W, Vanhees M, Collins MS, Dahm DL. Lateral tibial slope is increased with patients with early graft failure following ACL reconstruction.  Am J Sports Med. 2015 Oct;43(10):2510-4. PMID: 26320223

Krych AJ, Pitts RT, Dajani KA, Stuart MJ, Dahm DL, Levy BA. Surgical treatment of meniscal tears associated with anterior cruciate ligament reconstruction in pediatric patients.  Am J Sports Med. 2010 May;38(5):976-82.

Krych AJ, McIntosh AL, Voll AE, Stuart MJ, Dahm DL. Arthroscopic repair of isolated meniscal tears in patients 18 years and younger Am J Sports Med. 2008 Jul;36(7):1283-9

January Featured Author

Thomas J. Kremen, Jr., MD
Orthopaedic Surgeon, Cedars-Sinai Medical Center
Los Angeles, California

From the January issue: The Effect of Hamstring Tendon Autograft Harvest on the Restoration of Knee Stability in the Setting of Concurrent Anterior Cruciate Ligament and Medial Collateral Ligament Injuries

Podcast: Listen to Dr. Kremen discuss his article in the January issue.


Thomas Kremen, MD is a Board Certified Orthopaedic surgeon at Cedars-Sinai Medical Center in Los Angeles, California who specializes in Sports Medicine and Shoulder Surgery. He completed medical school and his residency training at the University of California, Los Angeles followed by fellowship training in Sports Medicine and Shoulder Surgery at Duke University. A former collegiate swimmer, he now serves as a team physician for USA Swimming and currently is the Chair of their Sports Medicine and Science Committee. His research has focused on the biomechanics of shoulder and knee reconstruction procedures, in vivo non-invasive imaging of therapeutic stem cells, and novel methods for improving the biology of healing musculoskeletal injuries. He has received research funding from the Orthopaedic Research and Education Foundation, the California Institute for Regenerative Medicine, as well as the American Orthopaedic Society for Sports Medicine. He serves as a member of the Electronic Media Editorial Board for the American Journal of Sports Medicine.

Selected Other Published Work in AJSM

Kremen TJ, Polakof LS, Rajaee S, Nelson TJ, Metzger MF. The effect of Hamstring Tendon Autograft Harvest on the Restoration of Knee Stability in the Setting of Anterior Cruciate Ligament Rupture and Concurrent Medial Collateral Ligament Injury. Am J Sports Med. 2017 Oct 1:363546517732743. PMID: 29048929

Neumann JA, Zgonis MH, Rickert KD, Bradley KE, Kremen TJ, Boggess BR, Toth AP. Interposition Dermal Matrix Xenografts: A Successful Alternative to Traditional Treatment of Massive Rotator Cuff Tears. Am J Sports Med. 2017 May;45(6):1261-1268. PMID: 28141953

Bernthal NM, Seeger LL, Motamedi K, Stavrakis AI, Kremen TJ, McAllister DR, Motamedi AR. Can the Reparability of Meniscus Tears be Predicted with MRI? Am J Sports Med. 2011 Mar;39(3):506-10. PMID: 21173193

December Featured Author

Andrew T. Pennock, MD

Rady Children’s Hospital
Associate Clinical Professor of Orthopaedic Surgery, University of California San Diego
San Diego, California

From the December issue: Segond Fractures Are Not a Risk Factor for Anterior Cruciate Ligament Reconstruction Failure

Podcast: Listen to Dr. Pennock discuss his article in the December issue.


Dr. Andrew Pennock is a pediatric and sports medicine surgeon at Rady Children’s Hospital-San Diego and an associate clinical professor at UC San Diego School of Medicine.

Graduating summa cum laude from Dartmouth College, where he was an All-American skier, Dr. Pennock went on to attend the University of Chicago Pritzker School of Medicine, where he graduated with honors and was a member of the Alpha Omega Alpha Honor Society. Upon completing his orthopedic residency and an orthopedic research fellowship at UC San Diego, he completed a sports medicine fellowship at the Steadman Clinic in Vail, Colorado, and a pediatric orthopedic fellowship at Rady Children’s.

Dr. Pennock primarily treats sports injuries in adolescents and young adults, with a special interest in knee, hip and shoulder injuries. He is also a team physician with the United States Ski Team, which he travels with on a regular basis.

Dr. Pennock continues to focus time on various research pursuits, including the developing hip as it pertains to femoroacetabular impingement and labral pathology, as well as pediatric and adolescent knee injuries.

Selected Other Published Work in AJSM

Are the Current Little League Pitching Guidelines Adequate? A Single-Season Prospective MRI Study. Pytiak AV, Stearns P, Bastrom TP, Dwek J, Kruk P, Roocroft JH, Pennock AT. Orthop J Sports Med. 2017 May 19; 5(5):2325967117704851.

The Pediatric/Adolescent Shoulder Survey (PASS): A Reliable Youth Questionnaire With Discriminant Validity and Responsiveness to Change. Edmonds EW, Bastrom TP, Roocroft JH, Calandra-Young VA, Pennock AT. Orthop J Sports Med. 2017 Mar 29;5(3):2325967117698466.

Does Allograft Augmentation of Small-Diameter Hamstring Autograft ACL Grafts Reduce the Incidence of Graft Retear? Pennock AT, Ho B, Parvanta K, Edmonds EW, Chambers HG, Roocroft JH, Bastrom TP. Am J Sports Med. 2017 Feb;45(2):334-338. doi: 10.1177/0363546516677545.

Are the Current Classifications and Radiographic Measurements for Trochlear Dysplasia Appropriate in the Skeletally Immature Patient? Stepanovich M, Bomar JD, Pennock AT. Orthop J Sports Med. 2016 Oct 24;4(10):2325967116669490.

Revision Meniscal Surgery in Children and Adolescents: Risk Factors and Mechanisms for Failure and Subsequent Management. Shieh AK, Edmonds EW, Pennock AT. Am J Sports Med. 2016 Apr;44(4):838-43. doi: 10.1177/0363546515623511.

Osteochondral allograft transplantation of the knee in the pediatric and adolescent population. Murphy RT, Pennock AT, Bugbee WD. Am J Sports Med. 2014 Mar;42(3):635-40. doi: 10.1177/0363546513516747.

Idiopathic Cam Morphology Is Not Caused by Subclinical Slipped Capital Femoral Epiphysis: An MRI and CT Study. Monazzam S, Bomar JD, Pennock AT. Orthop J Sports Med. 2013 Dec 6;1(7):2325967113512467. doi: 10.1177/2325967113512467. Corrigendum in: Orthop J Sports Med. 2014 Feb;2(2):2325967114525574.

Variation in tibial tubercle-trochlear groove measurement as a function of age, sex, size, and patellar instability. Pennock AT, Alam M, Bastrom T. Am J Sports Med. 2014 Feb;42(2):389-93. doi: 10.1177/0363546513509058.

Meniscus tear patterns in relation to skeletal immaturity: children versus adolescents. Shieh A, Bastrom T, Roocroft J, Edmonds EW, Pennock AT. Am J Sports Med. 2013 Dec;41(12):2779-83. doi: 10.1177/0363546513504286.

Prevalence of abnormal hip findings in asymptomatic participants: a prospective, blinded study. Register B, Pennock AT, Ho CP, Strickland CD, Lawand A, Philippon MJ. Am J Sports Med. 2012 Dec;40(12):2720-4. doi: 10.1177/0363546512462124.

The influence of arm and shoulder position on the bear-hug, belly-press, and lift-off tests: an electromyographic study. Pennock AT, Pennington WW, Torry MR, Decker MJ, Vaishnav SB, Provencher MT, Millett PJ, Hackett TR. Am J Sports Med. 2011 Nov;39(11):2338-46. doi: 10.1177/0363546510392710.

Does subchondral bone affect the fate of osteochondral allografts during storage? Pennock AT, Robertson CM, Wagner F, Harwood FL, Bugbee WD, Amiel D. Am J Sports Med. 2006 Apr;34(4):586-91.

Analysis of stored osteochondral allografts at the time of surgical implantation. Allen RT, Robertson CM, Pennock AT, Bugbee WD, Harwood FL, Wong VW, Chen AC, Sah RL, Amiel D. Am J Sports Med. 2005 Oct;33(10):1479-84.

November Featured Author

Raffy Mirzayan, MD

Co-Director of Sports Medicine
Director of Cartilage Repair and Restoration
Director of Resident Education
Department of Orthopaedic Surgery, Kaiser Permanente, Southern California
Clinical Professor of Orthopaedic Surgery
Keck School of Medicine, University of Southern California
Baldwin Park, California

From the November issue: Surgical Treatment of Distal Biceps Tendon Ruptures: An Analysis of Complications in 784 Surgical Repairs

Podcast: Listen to Dr. Mirzayan discuss his article in the November issue.


Dr. Raffy Mirzayan attained a Bachelor of Science degree from the University of California, Los Angeles with Departmental Honors in Kinesiology. He then graduated from the University of Southern California School of Medicine with Alpha Omega Alpha medical honors. He completed his residency in orthopaedic surgery at the Los Angeles County + University of Southern California Medical Center in Los Angeles, CA, where he was Chief Resident. He then completed a sports medicine fellowship at the prestigious Kerlan-Jobe Orthopaedic Clinic in Los Angeles.  Dr. Mirzayan is the Co-Director of Sports Medicine, Director of Cartilage Repair and Restoration, and Director of Resident Education at Kaiser Permanente, Baldwin Park, CA.  He also has a faculty appointment as Clinical Professor of Orthopaedic Surgery at the University of Southern California Keck School of Medicine.

Dr. Mirzayan has published three books in the field of orthopaedic surgery and sports medicine.  He is Co-Director of the ICJR Shoulder Course held annually in Las Vegas.

He has authored numerous peer-reviewed publications and book chapters. He has received several awards including the AOA-Zimmer Award, Vernon P. Thompson Award and DePuy Research Award.  He has presented his work at various national and international meetings.  He serves on several committees of local and national orthopaedic societies.  His orthopaedic interests include athletic injuries of the knee, shoulder, and elbow, including ligament repair and reconstruction, arthroscopy, and cartilage restoration and repair.

Selected Other Published Work in AJSM

Conroy C, Sethi P, Macken C, Wei D, Kowalsky M, Mirzayan R, Pauzenberger L, Dyrna F, Obopilwe E, Mazzocca AD. Augmentation of a Distal Biceps Repair with an Acellular Dermal Graft Restores Native Biomechanical Properties in a Tendon Deficient Model. Am J Sports Med. 2017 Jul; 45(9): 2028-2033; PMID: 28419811

Spragg LS, Chen J, Mirzayan R, Love RM, Maletis GB. The Effect of Autologous Hamstring Diameter on the Likelihood for Revision Anterior Cruciate Ligament Reconstruction. Amer J Sports Med. 2016; 44(6): 1475-81; PMID 27002103