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Dive into the research topics where Warren R. Dunn is active.

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Featured researches published by Warren R. Dunn.


Journal of Bone and Joint Surgery, American Volume | 2014

Symptoms of pain do not correlate with rotator cuff tear severity: a cross-sectional study of 393 patients with a symptomatic atraumatic full-thickness rotator cuff tear.

Warren R. Dunn; John E. Kuhn; Rosemary Sanders; Qi An; Keith M. Baumgarten; Julie Y. Bishop; Robert H. Brophy; James L. Carey; G. Brian Holloway; Grant L. Jones; C. Benjamin Ma; Robert G. Marx; Eric C. McCarty; Sourav Poddar; Matthew Smith; Edwin E. Spencer; Armando F. Vidal; Brian R. Wolf; Rick W. Wright

BACKGROUNDnFor many orthopaedic disorders, symptoms correlate with disease severity. The objective of this study was to determine if pain level is related to the severity of rotator cuff disorders.nnnMETHODSnA cohort of 393 subjects with an atraumatic symptomatic full-thickness rotator-cuff tear treated with physical therapy was studied. Baseline pretreatment data were used to examine the relationship between the severity of rotator cuff disease and pain. Disease severity was determined by evaluating tear size, retraction, superior humeral head migration, and rotator cuff muscle atrophy. Pain was measured on the 10-point visual analog scale (VAS) in the patient-reported American Shoulder and Elbow Surgeons (ASES) score. A linear multiple regression model was constructed with use of the continuous VAS score as the dependent variable and measures of rotator cuff tear severity and other nonanatomic patient factors as the independent variables. Forty-eight percent of the patients were female, and the median age was sixty-one years. The dominant shoulder was involved in 69% of the patients. The duration of symptoms was less than one month for 8% of the patients, one to three months for 22%, four to six months for 20%, seven to twelve months for 15%, and more than a year for 36%. The tear involved only the supraspinatus in 72% of the patients; the supraspinatus and infraspinatus, with or without the teres minor, in 21%; and only the subscapularis in 7%. Humeral head migration was noted in 16%. Tendon retraction was minimal in 48%, midhumeral in 34%, glenohumeral in 13%, and to the glenoid in 5%. The median baseline VAS pain score was 4.4.nnnRESULTSnMultivariable modeling, controlling for other baseline factors, identified increased comorbidities (p = 0.002), lower education level (p = 0.004), and race (p = 0.041) as the only significant factors associated with pain on presentation. No measure of rotator cuff tear severity correlated with pain (p > 0.25).nnnCONCLUSIONSnAnatomic features defining the severity of atraumatic rotator cuff tears are not associated with the pain level. Factors associated with pain are comorbidities, lower education level, and race.nnnLEVEL OF EVIDENCEnPrognostic Level III. See Instructions for Authors for a complete description of levels of evidence.


American Journal of Sports Medicine | 2013

Risk Factors for Meniscectomy After Meniscal Repair

Stephen Lyman; Chisa Hidaka; Ana S. Valdez; Iftach Hetsroni; Ting Jung Pan; Huong T. Do; Warren R. Dunn; Robert G. Marx

Background: Previous research suggests that a substantial percentage of meniscal repairs fail, resulting in a subsequent meniscectomy. Risk factors for failure have been investigated using small cohorts, providing ambiguous results. Purpose: To measure the frequency of and elucidate risk factors for subsequent meniscectomies after meniscal repair using a large study population from multiple surgical centers. Study Design: Case-control study; Level of evidence, 3. Methods: A total of 9529 patients who underwent 9609 outpatient meniscal repairs between 2003 and 2010 were identified from a statewide database of all ambulatory surgery in New York. Patients who subsequently underwent a meniscectomy were then identified. A Cox regression analysis was used to calculate the hazard ratio and 95% confidence intervals. The model included patient age, sex, comorbidities, concomitant arthroscopic procedures, laterality of the meniscus, and surgeon’s yearly meniscal repair volume. Results: The overall frequency of subsequent meniscectomies was 8.9%. Patients were at a decreased risk for subsequent meniscectomies if they underwent a concomitant anterior cruciate ligament (ACL) reconstruction (P < .001). Patients undergoing isolated meniscal repairs (without concomitant ACL reconstruction) were at a decreased risk if they were older (P < .001), had a lateral meniscal injury (P = .002), or were operated on by a surgeon with a higher annual meniscal repair volume (>24 cases/year; P < .001). Conclusion: A meniscectomy after meniscal repair is performed infrequently, supporting the notion that repairing a meniscus is a safe and effective procedure in the long term. The risk for undergoing subsequent meniscectomies is decreased in patients undergoing a concomitant ACL reconstruction, in cases of isolated meniscal repairs for patients of older age, and in patients undergoing meniscal repair by surgeons with a high case volume.


American Journal of Sports Medicine | 2014

Cost-Effectiveness Analysis of Early Reconstruction Versus Rehabilitation and Delayed Reconstruction for Anterior Cruciate Ligament Tears

Richard C. Mather; Carolyn M. Hettrich; Warren R. Dunn; Brian J. Cole; Bernard R. Bach; Laura J. Huston; Emily K. Reinke; Kurt P. Spindler; Lane Koenig; Annunziato Amendola; Jack T. Andrish; Christopher K. Kaeding; Robert G. Marx; Eric C. McCarty; Richard D. Parker; Rick W. Wright

Background: An initial anterior cruciate ligament (ACL) tear can be treated with surgical reconstruction or focused rehabilitation. The KANON (Knee Anterior cruciate ligament, NON-surgical versus surgical treatment) randomized controlled trial compared rehabilitation plus early ACL reconstruction (ACLR) to rehabilitation plus optional delayed ACLR and found no difference at 2 years by an intention-to-treat analysis of total Knee injury and Osteoarthritis Outcome Score (KOOS) results. Purpose: To compare the cost-effectiveness of early versus delayed ACLR. Study Design: Economic and decision analysis; Level of evidence, 2. Methods: A Markov decision model was constructed for a cost-utility analysis of early reconstruction (ER) versus rehabilitation plus optional delayed reconstruction (DR). Outcome probabilities and effectiveness were derived from 2 sources: the KANON study and the Multicenter Orthopaedic Outcomes Network (MOON) database. Collectively, these 2 sources provided data from 928 ACL-injured patients. Utilities were measured by the Short Form–6 dimensions (SF-6D). Costs were estimated from a societal perspective in 2012 US dollars. Costs and utilities were discounted in accordance with the United States Panel on Cost-Effectiveness in Health and Medicine. Effectiveness was expressed in quality-adjusted life-years (QALYs) gained. Principal outcome measures were average incremental costs, incremental effectiveness (as measured by QALYs), and net health benefits. Willingness to pay was set at


Sports Health: A Multidisciplinary Approach | 2015

Anterior Cruciate Ligament Reconstruction Rehabilitation MOON Guidelines

Rick W. Wright; Amanda K. Haas; Joy Anderson; Gary J. Calabrese; John T. Cavanaugh; Timothy E. Hewett; Dawn Lorring; Christopher McKenzie; Emily Preston; Glenn N. Williams; Annunziato Amendola; Jack T. Andrish; Robert H. Brophy; Charles L. Cox; Warren R. Dunn; David C. Flanigan; Carolyn M. Hettrich; Laura J. Huston; Morgan H. Jones; Christopher C. Kaeding; Christian Lattermann; Robert A. Magnussen; Robert G. Marx; Matthew J. Matava; Eric C. McCarty; Richard D. Parker; Emily K. Reinke; Matthew Smith; Kurt P. Spindler; Armando F. Vidal

50,000, which is the currently accepted standard in the United States. Results: In the base case, the ER group resulted in an incremental gain of 0.28 QALYs over the DR group, with a corresponding lower overall cost to society of


Journal of Shoulder and Elbow Surgery | 2014

The Duration of Symptoms does not correlate with Rotator Cuff Tear Severity or Other Patient Related Features. A Cross Sectional Study of Patients with Atraumatic, Full Thickness Rotator Cuff Tears

Kenneth P. Unruh; John E. Kuhn; Rosemary Sanders; Qi An; Keith M. Baumgarten; Julie Y. Bishop; Robert H. Brophy; James L. Carey; Brian G. Holloway; Grant L. Jones; Benjamin C. Ma; Robert G. Marx; Eric C. McCarty; Souray K. Poddar; Matthew Smith; Edwin E. Spencer; Armando F. Vidal; Brian R. Wolf; Rick W. Wright; Warren R. Dunn

1572. Effectiveness gains were driven by the low utility of an unstable knee and the lower utility for the DR group. The cost of rehabilitation and the rate of additional surgery drove the increased cost of the DR group. The most sensitive variable was the rate of knee instability after initial rehabilitation. When the rate of instability falls to 51.5%, DR is less costly, and when the rate of instability falls below 18.0%, DR becomes the preferred cost-effective strategy. Conclusion: An economic analysis of the timing of ACLR using data exclusively from the KANON trial, MOON cohort, and national average reimbursement revealed that early ACLR was more effective (improved QALYs) at a lower cost than rehabilitation plus optional delayed ACLR. Therefore, early ACLR should be the preferred treatment strategy from a societal health system perspective.


American Journal of Sports Medicine | 2016

Meniscal and Articular Cartilage Predictors of Clinical Outcome After Revision Anterior Cruciate Ligament Reconstruction

Rick W. Wright; Laura J. Huston; Samuel K. Nwosu; Amanda K. Haas; Christina R. Allen; Allen F. Anderson; Daniel E. Cooper; Thomas M. DeBerardino; Warren R. Dunn; Brett A. Lantz; Barton J. Mann; Kurt P. Spindler; Michael J. Stuart; John P. Albright; Annunziato Amendola; Jack T. Andrish; Christopher C. Annunziata; Robert A. Arciero; Bernard R. Bach; Champ L. Baker; Arthur R. Bartolozzi; Keith M. Baumgarten; Jeffery R. Bechler; Jeffrey H. Berg; Geoffrey A. Bernas; Stephen F. Brockmeier; Robert H. Brophy; J. Brad Butler; John D. Campbell; James L. Carey

Context: Anterior cruciate ligament (ACL) reconstruction rehabilitation has evolved over the past 20 years. This evolution has been driven by a variety of level 1 and level 2 studies. Evidence Acquisition: The MOON Group is a collection of orthopaedic surgeons who have developed a prospective longitudinal cohort of the ACL reconstruction patients. To standardize the management of these patients, we developed, in conjunction with our physical therapy committee, an evidence-based rehabilitation guideline. Study Design: Clinical review. Level of Evidence: Level 2. Results: This review was based on 2 systematic reviews of level 1 and level 2 studies. Recently, the guideline was updated by a new review. Continuous passive motion did not improve ultimate motion. Early weightbearing decreases patellofemoral pain. Postoperative rehabilitative bracing did not improve swelling, pain range of motion, or safety. Open chain quadriceps activity can begin at 6 weeks. Conclusion: High-level evidence exists to determine appropriate ACL rehabilitation guidelines. Utilizing this protocol follows the best available evidence.


Journal of Bone and Joint Surgery, American Volume | 2015

Baseline Predictors of Health-Related Quality of Life After Anterior Cruciate Ligament Reconstruction: A Longitudinal Analysis of a Multicenter Cohort at Two and Six Years

Warren R. Dunn; Brian R. Wolf; Frank E. Harrell; Emily K. Reinke; Laura J. Huston; Kurt P. Spindler; Samuel K. Nwosu; Christopher C. Kaeding; Richard D. Parker; Rick W. Wright; Jack T. Andrish; Eric C. McCarty; Annunziato Amendola; Robert G. Marx; Michelle Wolcott; Zhouwen Liu; JoAnn Alvarez

HYPOTHESISnThe purpose of this cross-sectional study is to determine whether the duration of symptoms influences the features seen in patients with atraumatic, full-thickness rotator cuff tears. Our hypothesis is that an increasing duration of symptoms will correlate with more advanced findings of rotator cuff tear severity on magnetic resonance imaging, worse shoulder outcome scores, more pain, decreased range of motion, and less strength.nnnMETHODSnWe enrolled 450 patients with full-thickness rotator cuff tears in a prospective cohort study to assess the effectiveness of nonoperative treatment and factors predictive of success. The duration of patient symptoms was divided into 4 groups: 3 months or less, 4 to 6 months, 7 to 12 months, and greater than 12 months. Data collected at patient entry into the study included (1) demographic data, (2) history and physical examination data, (3) radiographic imaging data, and (4) validated patient-reported measures of shoulder status. Statistical analysis included a univariate analysis with the Kruskal-Wallis test and Pearson test to identify statistically significant differences in these features for different durations of symptoms.nnnRESULTSnA longer duration of symptoms does not correlate with more severe rotator cuff disease. The duration of symptoms was not related to weakness, limited range of motion, tear size, fatty atrophy, or validated patient-reported outcome measures.nnnCONCLUSIONSnThere is only a weak relationship between the duration of symptoms and features associated with rotator cuff disease.


Osteoarthritis and Cartilage | 2015

Meniscus treatment and age associated with narrower radiographic joint space width 2-3 years after ACL reconstruction: data from the MOON onsite cohort.

Morgan H. Jones; Kurt P. Spindler; Braden C. Fleming; Jeffrey Duryea; Nancy A. Obuchowski; Erica A. Scaramuzza; Heidi L. Oksendahl; Carl S. Winalski; Carol L. Duong; Laura J. Huston; Richard D. Parker; Christopher C. Kaeding; Jack T. Andrish; David C. Flanigan; Warren R. Dunn; Emily K. Reinke

Background: Revision anterior cruciate ligament (ACL) reconstruction has been documented to have worse outcomes compared with primary ACL reconstructions. Purpose/Hypothesis: The purpose of this study was to determine if the prevalence, location, and/or degree of meniscal and chondral damage noted at the time of revision ACL reconstruction predicts activity level, sports function, and osteoarthritis symptoms at 2-year follow-up. The hypothesis was that meniscal loss and high-grade chondral damage noted at the time of revision ACL reconstruction will result in lower activity levels, decreased sports participation, more pain, more stiffness, and more functional limitation at 2 years after revision surgery. Study Design: Cohort study; Level of evidence, 2. Methods: Between 2006 and 2011, a total of 1205 patients who underwent revision ACL reconstruction by 83 surgeons at 52 hospitals were accumulated for study of the relationship of meniscal and articular cartilage damage to outcome. Baseline demographic and intraoperative data, including the International Knee Documentation Committee (IKDC) subjective knee evaluation, Knee injury and Osteoarthritis Outcome Score (KOOS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Marx activity score, were collected initially and at 2-year follow-up to test the hypothesis. Regression analysis was used to control for age, sex, body mass index, smoking status, activity level, baseline outcome scores, revision number, time since last ACL reconstruction, incidence of having a previous ACL reconstruction on the contralateral knee, previous and current meniscal and articular cartilage injury, graft choice, and surgeon years of experience to assess the meniscal and articular cartilage risk factors for clinical outcomes 2 years after revision ACL reconstruction. Results: At 2-year follow-up, 82% (989/1205) of the patients returned their questionnaires. It was found that previous meniscal injury and current articular cartilage damage were associated with the poorest outcomes, with prior lateral meniscectomy and current grade 3 to 4 trochlear articular cartilage changes having the worst outcome scores. Activity levels at 2 years were not affected by meniscal or articular cartilage pathologic changes. Conclusion: Prior lateral meniscectomy and current grade 3 to 4 changes of the trochlea were associated with worse outcomes in terms of decreased sports participation, more pain, more stiffness, and more functional limitation at 2 years after revision surgery, but they had no effect on activity levels. Registration: NCT00625885


Journal of Shoulder and Elbow Surgery | 2016

2013 Neer Award: predictors of failure of nonoperative treatment of chronic, symptomatic, full-thickness rotator cuff tears

Warren R. Dunn; John E. Kuhn; Rosemary Sanders; Qi An; Keith M. Baumgarten; Julie Y. Bishop; Robert H. Brophy; James L. Carey; Frank E. Harrell; Brian G. Holloway; Grant L. Jones; C. Benjamin Ma; Robert G. Marx; Eric C. McCarty; Sourav Poddar; Matthew Smith; Edwin E. Spencer; Armando F. Vidal; Brian R. Wolf; Rick W. Wright

BACKGROUNDnLimited information exists regarding predictors of general quality of life following anterior cruciate ligament (ACL) reconstruction with up to six-year follow-up. We hypothesized that certain variables evaluated at the time of ACL reconstruction will predict the general quality of life as measured by the Short Form-36 (SF-36).nnnMETHODSnAll unilateral ACL reconstructions from 2002 to 2004 in patients currently enrolled in a prospective multicenter cohort were evaluated. Patients preoperatively completed the SF-36 validated outcome instrument. Surgeons documented intra-articular pathological conditions and treatment, as well as the ACL reconstruction surgical technique. At baseline and at a minimum of two and six years postoperatively, patients completed the SF-36. Longitudinal analysis was performed for the two-year and six-year end points.nnnRESULTSnOf the initial 1512 subjects, at least one follow-up questionnaire was obtained from 1411 subjects (93%). The cohort was 44% female, and the median patient age at enrollment was twenty-three years. The mean scores were 41.9 points for the Physical Component Summary (PCS) and 51.7 points for the Mental Component Summary (MCS) at baseline, 53.6 points for the PCS and 52.0 points for the MCS at two years, and 54.0 points for the PCS and 52.4 points for the MCS at six years. Significant predictors of a higher PCS score were a higher baseline PCS score, younger age, lower baseline body mass index, having >50% of the lateral meniscus excised, or having no treatment done on a lateral meniscal tear. In contrast, significant predictors of a lower PCS score were a shorter follow-up time since surgery, revision ACL reconstruction, smoking at baseline, fewer years of education, and chondromalacia of the lateral tibial plateau. The mean utility gained at six years after ACL reconstruction was 5.3 quality-adjusted life years (QALYs).nnnCONCLUSIONSnLarge improvements in the PCS (with an effect size of 1.2) were noted at two years and were maintained at six years after ACL reconstruction. Lower education and smoking were significant predictors of lower PCS and MCS scores. ACL reconstruction resulted in a relatively high gain of QALYs.


Osteoarthritis and Cartilage | 2015

KOOS pain as a marker for significant knee pain two and six years after primary ACL reconstruction: A Multicenter Orthopaedic Outcomes Network (MOON) prospective longitudinal cohort study

D. Wasserstein; Laura J. Huston; Samuel K. Nwosu; Christopher C. Kaeding; Richard D. Parker; Rick W. Wright; Jack T. Andrish; Robert G. Marx; Annunziato Amendola; Brian R. Wolf; Eric C. McCarty; Michelle L. Wolcott; Warren R. Dunn; Kurt P. Spindler

OBJECTIVEnTo identify risk factors for radiographic signs of post-traumatic osteoarthritis (OA) 2-3 years after anterior cruciate ligament (ACL) reconstruction through multivariable analysis of minimum joint space width (mJSW) differences in a specially designed nested cohort.nnnMETHODSnA nested cohort within the Multicenter Orthopaedic Outcomes Network (MOON) cohort included 262 patients (148 females, average age 20) injured in sport who underwent ACL reconstruction in a previously uninjured knee, were 35 or younger, and did not have ACL revision or contralateral knee surgery. mJSW on semi-flexed radiographs was measured in the medial compartment using a validated computerized method. A multivariable generalized linear model was constructed to assess mJSW difference between the ACL reconstructed and contralateral control knees while adjusting for potential confounding factors.nnnRESULTSnUnexpectedly, we found the mean mJSW was 0.35 mm wider in ACL reconstructed than in control knees (5.06 mm (95% CI 4.96-5.15 mm) vs 4.71 mm (95% CI 4.62-4.80 mm), P < 0.001). However, ACL reconstructed knees with meniscectomy had narrower mJSW compared to contralateral normal knees by 0.64 mm (95% C.I. 0.38-0.90 mm) (P < 0.001). Age (P < 0.001) and meniscus repair (P = 0.001) were also significantly associated with mJSW difference.nnnCONCLUSIONnSemi-flexed radiographs can detect differences in mJSW between ACL reconstructed and contralateral normal knees 2-3 years following ACL reconstruction, and the unexpected wider mJSW in ACL reconstructed knees may represent the earliest manifestation of post-traumatic osteoarthritis and warrants further study.

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Rick W. Wright

The Ohio State University Wexner Medical Center

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Jack T. Andrish

Washington University in St. Louis

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Eric C. McCarty

University of Colorado Denver

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