bluuebunny/crossref_metadata_2025_split huggingface dataset:
Knee Hyperextension as a Predictor of Failure in Revision ACL Reconstruction
Authors: Cooper Daniel E. , Dunn Warren R. , Wright Rick W. , Haas Amanda , Huston Laura J. 
Published: July 2016

Objectives: We studied the minimum 2 year follow-up outcomes in an ACL revision cohort. The hypothesis is that knees that hyperextend will have a worse outcome and greater odds of graft failure than knees that do not hyperextend. The null hypothesis is that there is no difference in outcomes or graft rupture between the two groups. Methods: Revision ACL reconstruction patients were identified and prospectively enrolled between 2006 and 2011. Data collected included baseline demographics, surgical technique and pathology, and a series of validated patient reported outcome instruments (IKDC, KOOS, WOMAC, and Marx activity rating score). Patients were followed up for 2 years, and asked to complete the identical set of outcome instruments. A regression model using graft failure as the dependent variable included graft type, age, and hyperextension greater than or equal to 5 degrees yes/no (HE) in order to assess these potential surgical risk factors for clinical outcomes 2 years after revision ACL reconstruction. Results: There were 1,145 subjects included in the analyses. The median age of the cohort was 26 (IQR= 20, 35), and 58% were male. The proportion that were enrolled for their first revision surgery was 88%, their second 10%, and third or greater 2%. The number of subjects categorized as HE was 375 (33%). The median age of subjects that failed was 18, compared to 26 for those with intact grafts. All three variables included in our regression model were significant predictors of graft failure: younger age, inter-quartile range odds ratio (IQROR) = 3.32 (95%CI 1.5, 7.2) p= 0.002; use of allograft OR = 3.1 (95%CI 1.4, 6.9) p= 0.01, and HE 2.1 (95%CI 1.02, 4.42) p= 0.04. Conclusion: The MARS Study Group has previously reported that young age and the use of allograft as a graft source are independent predictors (over 3X odds ratio) of graft rupture after revision ACLR. This study found that knee hyperextension greater than or equal to 5 degrees is present in 1/3 of patients who undergo revision ACLR. HE is also an independent predictor of graft failure after revision ACLR. This is the first study to investigate and confirm knee physiologic hyperextension as a risk factor (over 2X odds ratio) of graft rupture in ACL surgery. Future reports on ACL reconstruction results should separately evaluate the group of knees that hyperextend 5 degrees or more as compared to those that do not.
Pre-operative Thresholds for Achieving Meaningful Clinical Improvement after Arthroscopic Treatment of Femoroacetabular Impingement
Authors: Nwachukwu Benedict U. , Fields Kara G. , Nawabi Danyal H. , Kelly Bryan T. , Ranawat Anil S. 
Published: July 2016

Objectives: Knowledge of the thresholds and determinants for successful femoroacetabular impingement (FAI) treatment is evolving. The primary purpose of this study was to define pre-operative outcome score thresholds that can be used to predict patients most likely to achieve meaningful clinically important difference (MCID) after arthroscopic FAI treatment. Secondarily determinants of achieving MCID were evaluated. Methods: A prospective institutional hip arthroscopy registry was reviewed to identify patients with FAI treated with arthroscopic labral surgery, acetabular rim trimming, and femoral osteochondroplasty. The modified Harris Hip Score (mHHS), the Hip Outcome Score (HOS) and the international Hip Outcome Tool (iHOT-33) tools were administered at baseline and at one year post-operatively. MCID was calculated using a distribution-based method. A receiver operating characteristic (ROC) analysis was used to calculate cohort-based threshold values predictive of achieving MCID. Area under the curve (AUC) was used to define predictive ability (strength of association) with AUC >0.7 considered acceptably predictive. Univariate and multivariable analyses were used to analyze demographic, radiographic and intra-operative factors associated with achieving MCID. Results: There were 374 patients (mean + SD age, 32.9 + 10.5) and 56.4% were female. The MCID for mHHS, HOS activities of daily living (HOS-ADL), HOS Sports, and iHOT-33 was 8.2, 8.4,14.5, and 12.0 respectively. ROC analysis (threshold, % achieving MCID, strength of association) for these tools in our population was: mHHS (61.6, 78%, 0.68), HOS-ADL (83.8, 68%, 0.84), HOS-Sports (63.9, 64%, 0.74), and iHOT-33 (54.3, 82%, 0.65). Likelihood for achieving MCID declined above and increased below these thresholds. In univariate analysis female sex, femoral version, lower acetabular outerbridge score and increasing CT sagittal center edge angle (CEA) were predictive of achieving MCID. In multivariable analysis sagittal CEA was the only variable maintaining significance (p = 0.032). Conclusion: We used a large prospective hip arthroscopy database to identify pre-operative patient outcome score thresholds predictive of meaningful post-operative outcome improvement after arthroscopic FAI treatment. This is the largest reported hip arthroscopy cohort to define MCID and the first to do so for iHOT-33. The HOS-ADL may have the best predictive ability for achieving MCID after hip arthroscopy. Patients with relatively high pre-operative ADL, quality of life and functional status appear to have a high chance for achieveing MCID up to our defined thresholds. Hip dysplasia is an important outcome modifier. The findings of this study may be useful for managing preoperative expectation for patients undergoing arthroscopic FAI surgery.
Minimally Important Differences and Change Across Time in Patients Treated Surgically and Non-Surgically for Full-Thickness Rotator Cuff Tears
Authors: Miller Bruce S. , Robbins Christopher , Gagnier Joel Joseph 
Published: July 2016

Objectives: The minimally important difference (MID) is the smallest change in an outcome measure that is perceived by patients as beneficial. The MIDs for the ASES and WORC scores have not been established in a homogenous population of patients with rotator cuff tears. The objective of the present study was to establish the MIDs for patients with known cuff tears who were treated both surgically and non-surgically, and to compare the MIDs over time. Methods: We included 209 subjects with known full-thickness rotator cuff tears who were followed prospectively for two years. The WORC and ASES scores were collected at baseline, 4, 8, 16, 32, and 48 weeks, 1 year and 2 years. At the final follow-up point patients filled out an end-of-study form which included questions regarding change in their condition after treatment. Results: For those that indicated being minimally better, the change from baseline for the ASES score was -20.57 (-2.94 to -38.20) and for the WORC was 418.60 (70.39 to 766.81); both indicated improvement in outcomes. When converted to the percentage change score the WORC change represented 19.93%. The plots of these new MID values for the ASES and WORC indicate that not only does the operative group improve more than the non-operative group but it does so to an extent that is greater than the MID. The non-operative group also improved across time, but the magnitude did not exceed the MID for either the WORC or the ASES. Conclusion: We found that the ASES and the WORC MIDs in patients with rotator cuff tears is different from that previously reported, and that the operative group change was greater than the non-operative group change. This information will directly improve our ability to: (1) Determine when patients with RCTs are changing in a meaningful manner; (2) Accurately power clinical studies using these outcome measures; (3) Make more informed choices of treatments in these patients. This is the first study to report MIDs for the ASES and WORC in a population of patients with strictly rotator cuff disease and to explore their changes relative to MIDs across time.
Is There an Association Between the “Critical Shoulder Angle” and Clinical Outcome after Rotator Cuff Repair?
Authors: Kirsch Jacob Matthew , Nathani Amit , Robbins Christopher , Gagnier Joel Joseph , Bedi Asheesh , Miller Bruce S. 
Published: July 2016

Objectives: Variations in scapular morphology have been associated with the development of atraumatic rotator cuff tears (RCT). Current theories suggest a morphologic predisposition for altered shoulder biomechanics favoring the development of RCTs. The critical shoulder angle (CSA) is a radiographic measure that accounts for both glenoid inclination and lateral extension of the acromion, and angles >35 degrees are reported to be correlated with the development of degenerative RCTs. The impact of the CSA on outcomes following rotator cuff repair (RCR) has not previously been investigated. The purpose of this study was to investigate the relationship between the CSA and clinical outcomes after rotator cuff repair. Methods: As part of a prospective observational cohort study we obtained CSA measurements for 144 patients with documented full-thickness RCTs who were followed up for a minimum of 48 weeks. Patients were then stratified based on RCT etiology and treatment. Demographic data as well as The Western Ontario Rotator Cuff Index (WORC), American Shoulder and Elbow Surgeons (ASES) score and Visual Analog Scale (VAS) for pain were collected at baseline, four, eight, 16, 32 and 48 weeks. The CSA for all of the patients was measured retrospectively, with all assessors being blinded to the data and we calculated interclass correlation coefficients (ICC) to measure agreement. The statistical analysis included longitudinal multilevel regression modeling to investigate the association of the CSA and the WORC, ASES and VAS for pain. Results: Controlling for demographic and clinical characteristics, patients with CSAs less than 38 degrees reported better outcome scores over time compared to those with CSAs greater than 38 degrees (WORC: B=-106.6, p=0.025, ASES: B=4.83, p=0.0001, VAS: B=-12.99, p=0.0001). Interobserver and intraobserver reliability for CSA measurements resulted in an ICC of 0.969 and 0.982 respectively, indicating excellent agreement. Conclusion: We found that a CSA less than 38 degrees was associated with better outcomes in patients following surgical repair of atraumatic full-thickness rotator cuff tears. This is the first study to examine the relationship between the CSA and outcomes following RCR. These findings suggest that individual scapular morphology may influence both disease development and surgical outcomes of rotator cuff tears. This association warrants further investigation.
Prospective Randomized Study of Arthroscopic Proximal vs Open Subpectoral Biceps Tenodesis
Authors: Gobezie Reuben , Shishani Yousef , Flocken Janice 
Published: July 2016

Objectives: The biceps tendon is recognized as a significant source of pain in the shoulder for many patients. Operative techniques for tenodesis of the biceps tendon vary widely. No studies have been conducted directly comparing arthroscopic proximal vs. open subpectoral biceps tenodesis using a prospective study. We aim to compare the functional outcomes, pain relief, and complications of proximal vs. subpectoral biceps tenodesis. Methods: A prospective randomized study of 129 consecutive patients requiring biceps tenodesis for treatment of biceps tendon tears, biceps instability or superior labral tears was performed. Clinical outcome measures used to conduct the study included active range of motion, VAS pain score, ASES score and SANE scores. Complications and revisions were also documented. Results: Mean follow-up was 13.2 months (12-24 months) with 50 subpectoral tenodesis and 46 proximal tenodesis patients reaching minimum follow-up of 12 months. In the subpectoral group, the VAS improved from 5.7 to 2.0 (p < 0.001), ASES score improved from 49.8 to 77.7 (p< 0.001), and SANE scores improved from 42.1% to 77.7% (p<0.001). In the arthroscopic proximal tenodesis group, the VAS pain score improved from 5.9 to 1.8 (p<0.001), ASES score improved from 52.0 to 82.5 (p<0.001), and SANE scores improved from 42.8% to 78.6% (p<0.001). The revision rate for the subpectoral group was 4% (2/50 patients). The revision rate for the arthroscopic proximal tenodesis group was 8.6% (4/46). Twelve patients had persistent tenderness over the bicipital groove: 7 following proximal tenodesis and 5 following subpectoral tenodesis. No significant difference was found between methods in any outcome measures evaluated. Conclusion: This study found no difference in the functional outcomes or pain relief between proximal vs subpectoral biceps tenodesis. However, revision rates and occurrence of post-operative persistent bicipital groove pain for arthroscopic proximal tenodesis with internal fixation screw were slightly higher than in the subpectoral approach.
The Rise of Concussions in the Adolescent Population
Authors: Zhang Alan L. , Sing David C. , Rugg Caitlin Marie , Feeley Brian T. , Senter Carlin 
Published: July 2016

Objectives: Concussion injuries have been correlated with significant long-term deleterious effects on patients. While recent studies have shown increased traumatic brain injuries (TBI) diagnosed in U.S. emergency departments, no studies have evaluated trends in concussion diagnoses across the general U.S. population in various age groups. The objective of this study is to evaluate the current incidence and trends in concussions diagnosed across varying age groups and healthcare settings in a large cross-sectional population. Methods: Administrative health records of 8,828,248 members of a large private payer insurance group in the United States were queried. Patients diagnosed with concussion from years 2007 through 2014 were stratified by year of diagnosis, age group, gender, classification of concussion, and healthcare setting of diagnosis (e.g. ED vs. physician’s office). Chi-square testing was used to for statistical analysis. Results: From a cohort of 8,828,248 patients, 43,884 patients were diagnosed with a concussion. Fifty-five percent of concussion patients were male and over 32% were in the adolescent age group (10-19 years old). The highest incidence of concussion was seen in the 15-19 age group (16.5 cases per 1000 patients) followed by the 10-14 (10.5 per 1000), 20-24 (5.2 per 1000) and 5-9 (3.5 per 1000) age groups. Overall there was a 160% increase in concussion incidence from 2007 to 2014. The largest increases were in the 10-14 (243%) and 15-19 (187%) age groups. Based on ICD-9 classification, 29% of concussions were associated with some form of loss of consciousness. Finally, 56% of concussions were diagnosed in the ED and 29% in a physician’s office, with the remainder in urgent cares or inpatient settings. Conclusion: The incidence of concussion diagnosed in the general population in the United States is increasing, driven largely by a substantial rise in the adolescent age group. The youth population should be prioritized for ongoing work in concussion education, diagnosis, treatment and prevention.
Quality of Movement for Athletes Six Months Post ACL Reconstruction
Authors: deMille Polly , Nguyen Joseph , Brown Allison , Do Huong , Selvaggio Elizabeth , Chiaia Theresa 
Published: July 2016

Objectives: Anterior cruciate ligament (ACL) injury prevention programs evaluate quality of movement (QM) to identify and correct high-risk movement patterns. However, return to play (RTP) decisions post-ACL reconstruction (ACLR) are often based on non-sport relatedquantitative measures such as isokinetic tests and/or time from surgery, with six months post-ACLR being a common expectation for RTP. The purpose of this study was to evaluate whether athletes are ready to RTP 6 months post ACLR using a QM assessment (QMA). Methods: A QMA including nine dynamic tasks (squat, single leg [SL] stance, step down, SL squat, jump in place, side to side jump, broad jump, hop to opposite, SL hop) progressing from double- to single-limb vertical and horizontal movements was administered to 136 athletes at five to seven months post-ACLR. Tasks were viewed from the frontal and sagittal planes by a physical therapist and performance specialist. Movements were evaluated live for risk factors associated with ACL injury (strategy, depth, control, symmetry, and alignment). The proportion of patients exhibiting risky movement patterns for each task was calculated. Fisher’s Exact test was used to determine if there were differences in movement patterns between males and females. Results: The proportion of patients demonstrating risky movement patterns for a task ranged from 48% to 100%. All 136 patients exhibited risky movement patterns for at least one task and 60% of patients displayed risky movement patterns in five or more of the nine tasks. Rates of risky movement patterns were not different between males and females for all tasks (P>0.1 for all tasks). Conclusion: Six months has been cited as a probable time for RTP post-ACLR; thus this is the expectation of the athlete. Our data show that athletes demonstrate multiple QM patterns associated with initial ACL injury, as well as 2nd injury at five to seven months post-operatively. Altered movement patterns evident in tasks as simple as a SL stance remained with the athlete through tasks of increasing difficulty. We recommend that therapists integrate QM screening into rehabilitation with a focus on movement retraining to address mechanical risk factors prior to RTP.
Vertical Jump Test as a Functional Test after Anterior Cruciate Ligament Reconstruction
Authors: Kim Jin Goo , Kim Sang Bum , Chung Kyu-Sung , Ha Jeong Ku 
Published: July 2016

Objectives: Among the various functional tests to determine the return to sports after anterior cruciate ligament reconstruction (ACLR), the most popular one is single leg hop for distance due to its convenience to perform in clinic based offices. Although its popularity, not many clinicians can actually assess with this test because it requires a spacious room to jump across, and another investigator to check the hopped distance, manually. The purpose of this study is to compare vertical jump test which can be assessed easily with a computerized system in a smaller room, with other functional tests, which are used widely as a guide for determining return to sport, and to assess the validity of vertical jump test as a functional performance test after ACLR. Methods: Seventy five ACL reconstructed patients (Mean age: 29.5±9.2 years, Mean height: 172.2±8.2 cm, Mean weight: 72.3±11.0 kg, Mean time since surgery: 27.5±6.1 months) completed subjective questionnaires (International Knee Documentation Committee (IKDC), Tegner and Lysholm scores) and functional performance tests; Single leg hop for distance, vertical jump test and three other functional performance tests (Cocontraction, Shuttle run, Carioca tests). Instability was measured with KT-2000. Peak torque/body weight ratio (PT/BW ratio) of extensor and flexor muscle is used to compensate the individual differences in the absolute values of isokinetic muscle strength. Limb symmetry index (LSI, %) was calculated for single leg hop for distance and vertical jump test which were tested separately in each limb. Correlation coefficients between LSI for vertical jump test and other measurements were analyzed. Results: LSI for vertical jump test was correlated to LSI for single leg hop for distance (r=0.354, p=0.002), cocontraction (r=-0.351, p=0.002), shuttle run (r=-0.358, p=0.002), Carioca test(r=-0.285, p=0.013), IKDC (r=0.316, p=0.006) and Tegner scores (r=0.237, p=0.041). There were no correlations with KT-2000 (p=0.626) and Lysholm score(p=0.198). In isokinetic strength tests, extensor PT/BW ratio (60 deg/sec: r=0.298, p=0.009; 180 deg/sec: r=0.247, p=0.033) and extensor strength deficit (60 deg/sec: r=-0.412, p<0.001; 180 deg/sec: r=-0.306, p=0.007) were correlated to LSI for vertical jump test, whereas flexor PT/BW ratio and flexor strength deficit were not. Conclusion: As the degrees of functional performance, subjective outcome scores and recovery of extensor strength are correlated with LSI for vertical jump test which clinician can easily assess with a computerized system in clinical offices, we suggest vertical jump test as a functional test after ACLR to determine the return to sports.
O’Donoghue Award Winner
Authors: Titchenal Matthew R. , Chu Constance R. , Erhart-Hledik Jennifer C. , Andriacchi Thomas P. 
Published: July 2016

Background: Altered knee kinematics after anterior cruciate ligament injury and reconstruction (ACLR) have been implicated in the development of premature osteoarthritis (OA), leading to poor long term clinical outcomes. Purpose: This study was performed to determine (1) whether average knee center of rotation (KCOR), a multidimensional metric of knee kinematics, of the ACLR knee during walking differs from that of the contralateral uninjured knee, (2) whether KCOR changes between 2 and 4 years after surgery, and (3) whether early KCOR changes predict patient reported outcomes 8 years after ACLR. Study Design: Prospective Clinical Study. Methods: Twenty-six human subjects underwent gait analysis with calculation of bilateral KCOR during walking at 2 and 4 years after unilateral ACLR. Knee injury and Osteoarthritis Outcome Scores (KOOS) and Lysholm scores were collected at 2, 4, and 8 years after ACLR in 13 of these subjects. Results: The ACLR knee showed greater medial compartment motion due to pivoting about a more lateral KCOR (P=0.03) than the uninjured contralateral knee at 2 years. KCOR moved medially over time (P=0.047), with values approaching those of the uninjured knee by 4 years (P=0.55). KCOR was also more anterior in the ACLR knee at 2 years (P=0.02). Between 2 and 4 years, KCOR moved posteriorly in 16 (62%) and anteriorly in 10 (38%) subjects. Increasing anterior position of KCOR in the ACLR knee from 2 to 4 years showed no correlation with clinical outcomes at 4 years but correlated with worsening clinical outcomes at 8 years: Lysholm (R2=0.41); KOOS pain (R2=0.37), symptoms (R2=0.58), and quality of life (R2=0.50). Conclusions: The observed changes to KCOR during walking between 2 and 4 years after ACLR show progressive improvement suggestive of continued graft maturation and neuromuscular recovery. The finding of increasingly abnormal kinematics correlating with reduced clinical outcomes years later in a subset of subjects provides a potential explanation for the incidence of premature OA following ACLR. These findings support progressing to more comprehensive studies of larger cohorts examining the predictive potential of KCOR for OA risk as measured by advanced quantitative imaging and radiographs. Clinical Relevance: These results suggest that changes to KCOR during walking as derived from gait analysis, a clinically available metric, may provide early warning of deteriorating knee function after ACLR years before the onset of clinical symptoms.