Armando F. Vidal

Cross-cultural Comparison of Patients Undergoing ACL Reconstruction in the United States and Norway

Data from large prospectively collected anterior cruciate ligament (ACL) cohorts are being utilized to address clinical questions regarding ACL injury demographics and outcomes of ACL reconstruction. These data are affected by patient and injury factors as well as surgical factors associated with the site of data collection. The aim of this article is to compare primary ACL reconstruction data from patient cohorts in the United States and Norway, demonstrating the similarities and differences between two large cohorts. Primary ACL reconstruction data from the Multicenter Orthopaedic Outcomes Network (MOON) in the United States and the Norwegian National Knee Ligament Registry (NKLR) were compared to identify similarities and differences in patient demographics, activity at injury, preoperative Knee injury and Osteoarthritis Outcome Score (KOOS), time to reconstruction, intraarticular pathology, and graft choice. Seven hundred and thirteen patients from the MOON cohort were compared with 4,928 patients from the NKLR. A higher percentage of males (NKLR 57%, MOON 52%; Pxa0<xa00.01) and increased patient age (NKLR 27xa0years, MOON 23xa0years; Pxa0<xa00.001) were noted in the NKLR population. The most common sports associated with injury in the MOON cohort were basketball (20%), soccer (17%), and American football (14%); while soccer (42%), handball (26%), and downhill skiing (10%) were most common in the NKLR. Median time to reconstruction was 2.4 (Interquartile range [IQR] 1.2–7.2) months in the MOON cohort and 7.9 (IQR 4.2–17.8) months in the NKLR cohort (Pxa0<xa00.001). Both meniscal tears (MOON 65%, NKLR 48%; Pxa0<xa00.001) and articular cartilage defects (MOON 46%, NKLR 26%; Pxa0<xa00.001) were more common in the MOON cohort. Hamstring autografts (MOON 44%, NKLR 63%) and patellar tendon autografts (MOON 42%, NKLR 37%) were commonly utilized in both cohorts. Allografts were much more frequently utilized in the MOON cohort (MOON 13%, NKLR 0.04%; Pxa0<xa00.001). Significant diversity in patient, injury, and surgical factors exist among large prospective cohorts collected in different locations. Surgeons should investigate and consider the characteristics of these cohorts when applying knowledge gleaned from these groups to their own patient populations.

Which Preoperative Factors, Including Bone Bruise, Are Associated With Knee Pain/Symptoms at Index Anterior Cruciate Ligament Reconstruction (ACLR)? A Multicenter Orthopaedic Outcomes Network (MOON) ACLR Cohort Study

Background: Increased knee pain at the time of anterior cruciate ligament reconstruction may potentially predict more difficult rehabilitation, prolonged recovery, and/or be predictive of increased knee pain at 2 years. Hypothesis: A bone bruise and/or other preoperative factors are associated with more knee pain/symptoms at the time of index anterior cruciate ligament reconstruction, and the presence of a bone bruise would be associated with specific demographic and injury-related factors. Study Design: Cohort study (prevalence); Level of evidence, 2. Methods: In 2007, the Multicenter Orthopaedic Outcomes Network (MOON) database began to prospectively collect surgeon-reported magnetic resonance imaging bone bruise status. A multivariable analysis was performed to (1) determine if a bone bruise, among other preoperative factors, is associated with more knee symptoms/pain and (2) examine the association of factors related to bone bruise. To evaluate the association of a bone bruise with knee pain/symptoms, linear multiple regression models were fit using the continuous scores of the Knee injury and Osteoarthritis Outcome Score (KOOS) symptoms and pain subscales and the Short Form 36 (SF-36) bodily pain subscale as dependent variables. To examine the association between a bone bruise and risk factors, a logistic regression model was used, in which the dependent variable was the presence or absence of a bone bruise. Results: Baseline data for 525 patients were used for analysis, and a bone bruise was present in 419 (80%). The cohort comprises 58% male patients, with a median age of 23 years. The median Marx activity level was 13. Factors associated with more pain were higher body mass index (P < .0001), female sex (P = .001), lateral collateral ligament injury (P = .012), and older age (P = .038). Factors associated with more symptoms were a concomitant lateral collateral ligament injury (P = .014), higher body mass index (P < .0001), and female sex (P < .0001). Bone bruise is not associated with symptoms/pain at the time of index anterior cruciate ligament reconstruction. None of the factors included in the SF-36 bodily pain model were found to be significant. After controlling for other baseline factors, the following factors were associated with a bone bruise: younger age (P = .034) and not jumping at the time of injury (P = .006). Conclusion: After anterior cruciate ligament injury, risk factors associated with a bone bruise are younger age and not jumping at the time of injury. Bone bruise is not associated with symptoms/pain at the time of index anterior cruciate ligament reconstruction.

Anterior Cruciate Ligament Reconstruction Rehabilitation MOON Guidelines

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.

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

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

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

BACKGROUNDnThe purpose of this study is to help define the indications for rotator cuff repair by identifying predictors of failure of nonoperative treatment.nnnMETHODSnA prospective, multicenter, cohort study design was used. All patients with full-thickness rotator cuff tears on magnetic resonance imaging were offered participation. Baseline data from this cohort were used to examine risk factors for failing a standard rehabilitation protocol. Patients who underwent surgery were defined as failing nonoperative treatment. A Cox proportional hazards model was fit to determinethe baseline factors that predicted failure. The dependent variable was time to surgery. The independent variables were tear severity and baseline patient factors: age, activity level, body mass index, sex, Single Assessment Numeric Evaluation score, visual analog scale score for pain, education, handedness, comorbidities, duration of symptoms, strength, employment, smoking status, and patient expectations.nnnRESULTSnOf the 433 subjects in this study, 87 underwent surgery with 93% follow-up at 1 year and 88% follow-up at 2 years. The median age was 62 years, and 49% were female patients. Multivariate modeling, adjusted for the covariates listed previously, identified patient expectations regarding physical therapy (Pu2009<u2009.0001) as the strongest predictor of surgery. Higher activity level (Pu2009=u2009.011) and not smoking (Pu2009=u2009.023) were also significant predictors of surgery.nnnCONCLUSIONnA patients decision to undergo surgery is influenced more by low expectations regarding the effectiveness of physical therapy than by patient symptoms or anatomic features of the rotator cuff tear. As such, patient symptoms and anatomic features of the chronic rotator cuff tear may not be the best features to use when deciding on surgical intervention.

Ten-Year Outcomes and Risk Factors After Anterior Cruciate Ligament Reconstruction: A MOON Longitudinal Prospective Cohort Study:

Background: The long-term prognosis and risk factors for quality of life and disability after anterior cruciate ligament (ACL) reconstruction remain unknown. Hypothesis/Purpose: Our objective was to identify patient-reported outcomes and patient-specific risk factors from a large prospective cohort at a minimum 10-year follow-up after ACL reconstruction. We hypothesized that meniscus and articular cartilage injuries, revision ACL reconstruction, subsequent knee surgery, and certain demographic characteristics would be significant risk factors for inferior outcomes at 10 years. Study Design: Therapeutic study; Level of evidence, 2. Methods: Unilateral ACL reconstruction procedures were identified and prospectively enrolled between 2002 and 2004 from 7 sites in the Multicenter Orthopaedic Outcomes Network (MOON). Patients preoperatively completed a series of validated outcome instruments, including the International Knee Documentation Committee (IKDC), Knee injury and Osteoarthritis Outcome Score (KOOS), and Marx activity rating scale. At the time of surgery, physicians documented all intra-articular abnormalities, treatment, and surgical techniques utilized. Patients were followed at 2, 6, and 10 years postoperatively and asked to complete the same outcome instruments that they completed at baseline. The incidence and details of any subsequent knee surgeries were also obtained. Multivariable regression analysis was used to identify significant predictors of the outcome. Results: A total of 1592 patients were enrolled (57% male; median age, 24 years). Ten-year follow-up was obtained on 83% (n = 1320) of the cohort. Both IKDC and KOOS scores significantly improved at 2 years and were maintained at 6 and 10 years. Conversely, Marx scores dropped markedly over time, from a median score of 12 points at baseline to 9 points at 2 years, 7 points at 6 years, and 6 points at 10 years. The patient-specific risk factors for inferior 10-year outcomes were lower baseline scores; higher body mass index; being a smoker at baseline; having a medial or lateral meniscus procedure performed before index ACL reconstruction; undergoing revision ACL reconstruction; undergoing lateral meniscectomy; grade 3 to 4 articular cartilage lesions in the medial, lateral, or patellofemoral compartments; and undergoing any subsequent ipsilateral knee surgery after index ACL reconstruction. Conclusion: Patients were able to perform sports-related functions and maintain a relatively high knee-related quality of life 10 years after ACL reconstruction, although activity levels significantly declined over time. Multivariable analysis identified several key modifiable risk factors that significantly influence the outcome.

Surgical Predictors of Clinical Outcomes after Revision Anterior Cruciate Ligament Reconstruction

Background: Revision anterior cruciate ligament (ACL) reconstruction has been documented to have worse outcomes compared with primary ACL reconstruction. Hypothesis: Certain factors under the control of the surgeon at the time of revision surgery can both negatively and positively affect outcomes. Study Design: Case-control study; Level of evidence, 3. Methods: Patients undergoing revision ACL reconstruction were identified and prospectively enrolled between 2006 and 2011. Data collected included baseline demographics, intraoperative surgical technique and joint disorders, and a series of validated patient-reported outcome instruments (International Knee Documentation Committee [IKDC] subjective form, Knee Injury and Osteoarthritis Outcome Score [KOOS], Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], and Marx activity rating scale) completed before surgery. Patients were followed up for 2 years and asked to complete an identical set of outcome instruments. Regression analysis was used to control for age, sex, body mass index (BMI), activity level, baseline outcome scores, revision number, time since last ACL reconstruction, and a variety of previous and current surgical variables to assess the surgical risk factors for clinical outcomes 2 years after revision ACL reconstruction. Results: A total of 1205 patients (697 male [58%]) met the inclusion criteria and were successfully enrolled. The median age was 26 years, and the median time since their last ACL reconstruction was 3.4 years. Two-year follow-up was obtained on 82% (989/1205). Both previous and current surgical factors were found to be significant contributors toward poorer clinical outcomes at 2 years. Having undergone previous arthrotomy (nonarthroscopic open approach) for ACL reconstruction compared with the 1-incision technique resulted in significantly poorer outcomes for the 2-year IKDC (P = .037; odds ratio [OR], 2.43; 95% CI, 1.05-5.88) and KOOS pain, sports/recreation, and quality of life (QOL) subscales (P ≤ .05; OR range, 2.38-4.35; 95% CI, 1.03-10.00). The use of a metal interference screw for current femoral fixation resulted in significantly better outcomes for the 2-year KOOS symptoms, pain, and QOL subscales (P ≤ .05; OR range, 1.70-1.96; 95% CI, 1.00-3.33) as well as WOMAC stiffness subscale (P = .041; OR, 1.75; 95% CI, 1.02-3.03). Not performing notchplasty at revision significantly improved 2-year outcomes for the IKDC (P = .013; OR, 1.47; 95% CI, 1.08-1.99), KOOS activities of daily living (ADL) and QOL subscales (P ≤ .04; OR range, 1.40-1.41; 95% CI, 1.03-1.93), and WOMAC stiffness and ADL subscales (P ≤ .04; OR range, 1.41-1.49; 95% CI, 1.03-2.05). Factors before revision ACL reconstruction that increased the risk of poorer clinical outcomes at 2 years included lower baseline outcome scores, a lower Marx activity score at the time of revision, a higher BMI, female sex, and a shorter time since the patient’s last ACL reconstruction. Prior femoral fixation, prior femoral tunnel aperture position, and knee flexion angle at the time of revision graft fixation were not found to affect 2-year outcomes in this revision cohort. Conclusion: There are certain surgical variables that the physician can control at the time of revision ACL reconstruction that can modify clinical outcomes at 2 years. Whenever possible, opting for an anteromedial portal or transtibial surgical exposure, choosing a metal interference screw for femoral fixation, and not performing notchplasty are associated with significantly better 2-year clinical outcomes.

Physiologic Preoperative Knee Hyperextension Is a Predictor of Failure in an Anterior Cruciate Ligament Revision Cohort: A Report From the MARS Group:

Background: The occurrence of physiologic knee hyperextension (HE) in the revision anterior cruciate ligament reconstruction (ACLR) population and its effect on outcomes have yet to be reported. Hypothesis/Purpose: The prevalence of knee HE in revision ACLR and its effect on 2-year outcome were studied with the hypothesis that preoperative physiologic knee HE ≥5° is a risk factor for anterior cruciate ligament (ACL) graft rupture. Study Design: Cohort study; Level of evidence, 2. Methods: Patients undergoing revision ACLR were identified and prospectively enrolled between 2006 and 2011. Study inclusion criteria were patients undergoing single-bundle graft reconstructions. Patients were followed up at 2 years and asked to complete an identical set of outcome instruments (International Knee Documentation Committee, Knee injury and Osteoarthritis Outcome Score, WOMAC, and Marx Activity Rating Scale) as well as provide information regarding revision ACL graft failure. A regression model with graft failure as the dependent variable included age, sex, graft type at the time of the revision ACL surgery, and physiologic preoperative passive HE ≥5° (yes/no) to assess these as potential risk factors for clinical outcomes 2 years after revision ACLR. Results: Analyses included 1145 patients, for whom 2-year follow-up was attained for 91%. The median age was 26 years, with age being a continuous variable. Those below the median were grouped as “younger” and those above as “older” (age: interquartile range = 20, 35 years), and 42% of patients were female. There were 50% autografts, 48% allografts, and 2% that had a combination of autograft plus allograft. Passive knee HE ≥5° was present in 374 (33%) patients in the revision cohort, with 52% being female. Graft rupture at 2-year follow-up occurred in 34 cases in the entire cohort, of which 12 were in the HE ≥5° group (3.2% failure rate) and 22 in the non-HE group (2.9% failure rate). The median age of patients who failed was 19 years, as opposed to 26 years for those with intact grafts. Three variables in the regression model were significant predictors of graft failure: younger age (odds ratio [OR] = 3.6; 95% CI, 1.6-7.9; P = .002), use of allograft (OR = 3.3; 95% CI, 1.5-7.4; P = .003), and HE ≥5° (OR = 2.12; 95% CI, 1.1-4.7; P = .03). Conclusion: This study revealed that preoperative physiologic passive knee HE ≥5° is present in one-third of patients who undergo revision ACLR. HE ≥5° was an independent significant predictor of graft failure after revision ACLR with a >2-fold OR of subsequent graft rupture in revision ACL surgery. Registration: NCT00625885 (ClinicalTrials.gov identifier).

Risk Factors and Predictors of Significant Chondral Surface Change From Primary to Revision Anterior Cruciate Ligament Reconstruction: A MOON and MARS Cohort Study:

Background: Articular cartilage health is an important issue following anterior cruciate ligament (ACL) injury and primary ACL reconstruction. Factors present at the time of primary ACL reconstruction may influence the subsequent progression of articular cartilage damage. Hypothesis: Larger meniscus resection at primary ACL reconstruction, increased patient age, and increased body mass index (BMI) are associated with increased odds of worsened articular cartilage damage at the time of revision ACL reconstruction. Study Design: Case-control study; Level of evidence, 3. Methods: Subjects who had primary and revision data in the databases of the Multicenter Orthopaedics Outcomes Network (MOON) and Multicenter ACL Revision Study (MARS) were included. Reviewed data included chondral surface status at the time of primary and revision surgery, meniscus status at the time of primary reconstruction, primary reconstruction graft type, time from primary to revision ACL surgery, as well as demographics and Marx activity score at the time of revision. Significant progression of articular cartilage damage was defined in each compartment according to progression on the modified Outerbridge scale (increase ≥1 grade) or >25% enlargement in any area of damage. Logistic regression identified predictors of significant chondral surface change in each compartment from primary to revision surgery. Results: A total of 134 patients were included, with a median age of 19.5 years at revision surgery. Progression of articular cartilage damage was noted in 34 patients (25.4%) in the lateral compartment, 32 (23.9%) in the medial compartment, and 31 (23.1%) in the patellofemoral compartment. For the lateral compartment, patients who had >33% of the lateral meniscus excised at primary reconstruction had 16.9-times greater odds of progression of articular cartilage injury than those with an intact lateral meniscus (P < .001). For the medial compartment, patients who had <33% of the medial meniscus excised at the time of the primary reconstruction had 4.8-times greater odds of progression of articular cartilage injury than those with an intact medial meniscus (P = .02). Odds of significant chondral surface change increased by 5% in the lateral compartment and 6% in the medial compartment for each increased year of age (P ≤ .02). For the patellofemoral compartment, the use of allograft in primary reconstruction was associated with a 15-fold increased odds of progression of articular cartilage damage relative to a patellar tendon autograft (P < .001). Each 1-unit increase in BMI at the time of revision surgery was associated with a 10% increase in the odds of progression of articular cartilage damage (P = .046) in the patellofemoral compartment. Conclusion: Excision of the medial and lateral meniscus at primary ACL reconstruction increases the odds of articular cartilage damage in the corresponding compartment at the time of revision ACL reconstruction. Increased age is a risk factor for deterioration of articular cartilage in both tibiofemoral compartments, while increased BMI and the use of allograft for primary ACL reconstruction are associated with an increased risk of progression in the patellofemoral compartment.