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Background: A primary goal of anterior cruciate ligament reconstruction (ACLR) is to reduce pathologically increased anterior and rotational laxity of the knee, but the effects of residual laxity on patient-reported outcomes (PROs) after ACLR remain unclear. Hypothesis: Increased residual laxity at 2 years postoperatively is predictive of a higher risk of subsequent ipsilateral knee surgery and decreases in PRO scores from 2 to 6 years after surgery. Study Design: Cohort study; Level of evidence, 2. Methods: From a prospective multicenter cohort, 433 patients aged 6 mm) in laxity at 2 years postoperatively. Multiple linear regression models were built to determine the relationship between 2-year postoperative knee laxity and 2- to 6-year change in PROs while controlling for age, sex, body mass index, smoking status, meniscal and cartilage status, and graft type. Results: A total of 381 patients (87.9%) were available for follow-up 6 years postoperatively. There were no significant differences in risk of subsequent knee surgery based on residual knee laxity. Patients with a difference >6 mm in side-to-side anterior laxity at 2 years postoperatively were noted to have a larger decrease in PROs from 2 to 6 years postoperatively ( P < .05). No significant differences in any PROs were noted among patients with a difference Conclusion: The presence of a residual side-to-side KT-1000 arthrometer difference 6 mm in side-to-side anterior laxity were noted to have significantly decreased PROs at 6 years after ACLR.

Background: Although graft choice may be limited in the revision setting based on previously used grafts, most surgeons believe that graft choice for anterior cruciate ligament (ACL) reconstruction is an important factor related to outcome. Hypothesis: In the ACL revision setting, there would be no difference between autograft and allograft in rerupture rate and patient-reported outcomes (PROs) at 6-year follow-up. Study Design: Cohort study; Level of evidence, 2. Methods: Patients who had revision surgery were identified and prospectively enrolled in this cohort study by 83 surgeons over 52 sites. Data collected included baseline characteristics, surgical technique and pathology, and a series of validated PRO measures. Patients were followed up at 6 years and asked to complete the identical set of PRO instruments. Incidence of additional surgery and reoperation because of graft failure were also recorded. Multivariable regression models were used to determine the predictors (risk factors) of PROs, graft rerupture, and reoperation at 6 years after revision surgery. Results: A total of 1234 patients including 716 (58%) men were enrolled. A total of 325 (26%) underwent revision using a bone-patellar tendon-bone (BTB) autograft; 251 (20%), soft tissue autograft; 289 (23%), BTB allograft; 302 (25%), soft tissue allograft; and 67 (5%), other graft. Questionnaires and telephone follow-up for subsequent surgery information were obtained for 809 (66%) patients, while telephone follow-up was only obtained for an additional 128 patients for the total follow-up on 949 (77%) patients. Graft choice was a significant predictor of 6-year Marx Activity Rating Scale scores ( P = .024). Specifically, patients who received a BTB autograft for revision reconstruction had higher activity levels than did patients who received a BTB allograft (odds ratio [OR], 1.92; 95% CI, 1.25-2.94). Graft rerupture was reported in 5.8% (55/949) of patients by their 6-year follow-up: 3.5% (16/455) of patients with autografts and 8.4% (37/441) of patients with allografts. Use of a BTB autograft for revision resulted in patients being 4.2 times less likely to sustain a subsequent graft rupture than if a BTB allograft were utilized ( P = .011; 95% CI, 1.56-11.27). No significant differences were found in graft rerupture rates between BTB autograft and soft tissue autografts ( P = .87) or between BTB autografts and soft tissue allografts ( P = .36). Use of an autograft was found to be a significant predictor of having fewer reoperations within 6 years compared with using an allograft ( P = .010; OR, 0.56; 95% CI, 0.36-0.87). Conclusion: BTB and soft tissue autografts had a decreased risk in graft rerupture compared with BTB allografts. BTB autografts were associated with higher activity level than were BTB allografts at 6 years after revision reconstruction. Surgeons and patients should consider this information when choosing a graft for revision ACL reconstruction.

Background: The incidence of posttraumatic osteoarthritis (PTOA) based on clinical radiographic grading criteria at 10 years after anterior cruciate ligament (ACL) reconstruction (ACLR) has not been well-defined in a prospective cohort of young athletic patients. Hypothesis: Among young athletic patients, there is a high incidence of clinical radiographic PTOA at 10 years after ACLR. Additionally, there is a significant difference in clinical radiographic osteoarthritis (OA) changes (joint space narrowing and osteophyte formation) between ACL-reconstructed and contralateral knees at 10 years. Study Design: Case series; Level of evidence, 4. Methods: The first 146 patients in an ongoing nested cohort study of the Multicenter Orthopaedic Outcomes Network (MOON) prospective cohort presented for a minimum 10-year follow-up. Included patients had a sports-related ACL injury, were aged Results: Interrater reliability was substantial for the IKDC (Gwet Agreement Coefficient [AC] 1 = 0.71), moderate for the KL (0.48), and almost perfect for the OARSI (0.84) grading systems. Among patients with a contralateral radiographically normal knee, the 10-year incidence of clinical radiographic PTOA after ACLR was 37% as defined by osteophytes and 23% as defined by joint space narrowing. The maximum side-to-side difference in the OARSI osteophyte grade in the medial or lateral compartment was 0 in 65% of patients, 1 in 20%, and ≥2 in 15%. The maximum side-to-side difference in the OARSI joint space narrowing grade was 0 in 77% of patients, 1 in 19%, and ≥2 in 4%. Conclusion: In young active patients, the 10-year incidence of clinical radiographic PTOA after ACLR was 37% as defined by osteophytes and 23% as defined by joint space narrowing. The mean difference in the degree of osteophyte formation (≤1 grade in 85%) and joint space narrowing (≤1 grade in 96%) between the ACL-reconstructed and contralateral knees was small. Registration: NCT02717559 (ClinicalTrials.gov identifier)

Background: Meniscal preservation has been demonstrated to contribute to long-term knee health. This has been a successful intervention in patients with isolated tears and tears associated with anterior cruciate ligament (ACL) reconstruction. However, the results of meniscal repair in the setting of revision ACL reconstruction have not been documented. Purpose: To examine the prevalence and 2-year operative success rate of meniscal repairs in the revision ACL setting. Study Design: Case-control study; Level of evidence, 3. Methods: All cases of revision ACL reconstruction with concomitant meniscal repair from a multicenter group between 2006 and 2011 were selected. Two-year follow-up was obtained by phone and email to determine whether any subsequent surgery had occurred to either knee since the initial revision ACL reconstruction. If so, operative reports were obtained, whenever possible, to verify the pathologic condition and subsequent treatment. Results: In total, 218 patients (18%) from 1205 revision ACL reconstructions underwent concurrent meniscal repairs. There were 235 repairs performed: 153 medial, 48 lateral, and 17 medial and lateral. The majority of these repairs (n = 178; 76%) were performed with all-inside techniques. Two-year surgical follow-up was obtained on 90% (197/218) of the cohort. Overall, the meniscal repair failure rate was 8.6% (17/197) at 2 years. Of the 17 failures, 15 were medial (13 all-inside, 2 inside-out) and 2 were lateral (both all-inside). Four medial failures were treated in conjunction with a subsequent repeat revision ACL reconstruction. Conclusion: Meniscal repair in the revision ACL reconstruction setting does not have a high failure rate at 2-year follow-up. Failure rates for medial and lateral repairs were both

Background: The cause of subsequent surgery after anterior cruciate ligament (ACL) reconstruction varies, but if risk factors for specific subsequent surgical procedures can be identified, we can better understand which patients are at greatest risk. Purpose: To report the incidence and types of subsequent surgery that occurred in a cohort of patients 6 years after their index ACL reconstruction and to identify which variables were associated with the incidence of patients undergoing subsequent surgery after their index ACL reconstruction. Study Design: Cohort study; Level of evidence, 2. Methods: Patients completed a questionnaire before their index ACL surgery and were followed up at 2 and 6 years. Patients were contacted to determine whether any underwent additional surgery since baseline. Operative reports were obtained, and all surgical procedures were categorized and recorded. Logistic regression models were constructed to predict which patient demographic and surgical variables were associated with the incidence of undergoing subsequent surgery after their index ACL reconstruction. Results: The cohort consisted of 3276 patients (56.3% male) with a median age of 23 years. A 6-year follow-up was obtained on 91.5% (2999/3276) with regard to information on the incidence and frequency of subsequent surgery. Overall, 20.4% (612/2999) of the cohort was documented to have undergone at least 1 subsequent surgery on the ipsilateral knee 6 years after their index ACL reconstruction. The most common subsequent surgical procedures were related to the meniscus (11.9%), revision ACL reconstruction (7.5%), loss of motion (7.8%), and articular cartilage (6.7%). Significant risk factors for incurring subsequent meniscus-related surgery were having a medial meniscal repair at the time of index surgery, reconstruction with a hamstring autograft or allograft, higher baseline Marx activity level, younger age, and cessation of smoking. Significant predictors of undergoing subsequent surgery involving articular cartilage were higher body mass index, higher Marx activity level, reconstruction with a hamstring autograft or allograft, meniscal repair at the time of index surgery, or a grade 3/4 articular cartilage abnormality classified at the time of index ACL reconstruction. Risk factors for incurring subsequent surgery for loss of motion were younger age, female sex, low baseline Knee injury and Osteoarthritis Outcome Score symptom subscore, and reconstruction with a soft tissue allograft. Conclusion: These findings can be used to identify patients who are at the greatest risk of incurring subsequent surgery after ACL reconstruction.

Background: Anterior cruciate ligament (ACL) revision cohorts continually report lower outcome scores on validated knee questionnaires than primary ACL cohorts at similar time points after surgery. It is unclear how these outcomes are associated with physical activity after physician clearance for return to recreational or competitive sports after ACL revision surgery. Hypotheses: Participants who return to either multiple sports or a singular sport after revision ACL surgery will report decreased knee symptoms, increased activity level, and improved knee function as measured by validated patient-reported outcome measures (PROMs) and compared with no sports participation. Multisport participation as compared with singular sport participation will result in similar increased PROMs and activity level. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 1205 patients who underwent revision ACL reconstruction were enrolled by 83 surgeons at 52 clinical sites. At the time of revision, baseline data collected included the following: demographics, surgical characteristics, previous knee treatment and PROMs, the International Knee Documentation Committee (IKDC) questionnaire, Marx activity score, Knee injury and Osteoarthritis Outcome Score (KOOS), and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). A series of multivariate regression models were used to evaluate the association of IKDC, KOOS, WOMAC, and Marx Activity Rating Scale scores at 2 years after revision surgery by sports participation category, controlling for known significant covariates. Results: Two-year follow-up was obtained on 82% (986 of 1205) of the original cohort. Patients who reported not participating in sports after revision surgery had lower median PROMs both at baseline and at 2 years as compared with patients who participated in either a single sport or multiple sports. Significant differences were found in the change of scores among groups on the IKDC ( P < .0001), KOOS-Symptoms ( P = .01), KOOS–Sports and Recreation ( P = .04), and KOOS–Quality of Life ( P < .0001). Patients with no sports participation were 2.0 to 5.7 times more likely than multiple-sport participants to report significantly lower PROMs, depending on the specific outcome measure assessed, and 1.8 to 3.8 times more likely than single-sport participants (except for WOMAC-Stiffness, P = .18), after controlling for known covariates. Conclusion: Participation in either a single sport or multiple sports in the 2 years after ACL revision surgery was found to be significantly associated with higher PROMs across multiple validated self-reported assessment tools. During follow-up appointments, surgeons should continue to expect that patients who report returning to physical activity after surgery will self-report better functional outcomes, regardless of baseline activity levels.

Background: Opioid use and public insurance have been correlated with worse outcomes in a number of orthopaedic surgeries. These factors have not been investigated with anterior cruciate ligament reconstruction (ACLR). Purpose/Hypothesis: To evaluate if narcotic use, physical therapy location, and insurance type are predictors of patient-reported outcomes after ACLR. It was hypothesized that at 1 year postsurgically, increased postoperative narcotic use would be associated with worse outcomes, physical therapy obtained within the authors’ integrated health care system would lead to better outcomes, and public insurance would lead to worse outcomes and athletic activity. Study Design: Cohort study; Level of evidence, 2. Methods: All patients undergoing unilateral, primary ACLR between January 2015 and February 2016 at a large health system were enrolled in a standard-of-care prospective cohort. Knee injury and Osteoarthritis Score (KOOS) and the Hospital for Special Surgery Pediatric–Functional Activity Brief Scale (HSS Pedi-FABS) were collected before surgery and at 1 year postoperatively. Concomitant knee pathology was assessed arthroscopically and electronically captured. Patient records were analyzed to determine physical therapy location, insurance status, and narcotic use. Multivariable regression analyses were used to identify significant predictors of the KOOS and HSS Pedi-FABS score. Results: A total of 258 patients were included in the analysis (mean age, 25.8; 51.2% women). In multivariable regression analysis, narcotic use, physical therapy location, and insurance type were not independent predictors of any KOOS subscales. Public insurance was associated with a lower HSS Pedi-FABS score (–4.551, P = .047) in multivariable analysis. Narcotic use or physical therapy location was not associated with the HSS Pedi-FABS score. Conclusion: Increased narcotic use surrounding surgery, physical therapy location within the authors’ health care system, and public versus private insurance were not associated with disease-specific KOOS subscale scores. Patients with public insurance had worse HSS Pedi-FABS activity scores compared with patients with private insurance, but neither narcotic use nor physical therapy location was associated with activity scores. Physical therapy location did not influence outcomes, suggesting that patients be given a choice in the location they received physical therapy (as long as a standardized protocol is followed) to maximize compliance.

Background: The Knee injury and Osteoarthritis Outcome Score (KOOS) has demonstrated inferior psychometric properties when compared with the International Knee Documentation Committee (IKDC) subjective knee form when assessing outcomes after anterior cruciate ligament (ACL) reconstruction. The KOOS, Joint Replacement (KOOS, JR) is a validated short-form instrument to assess patient-reported outcomes (PROs) after knee arthroplasty, and the purpose of this study was to determine if augmenting the KOOS, JR with additional KOOS items would allow for the creation of a short-form KOOS-based global knee score for patients undergoing ACL reconstruction, with psychometric properties similar to those of the IKDC. Hypothesis: An augmented version of the KOOS, JR could be created that would demonstrate convergent validity with the IKDC but avoid the ceiling effects and limitations previously noted with several of the KOOS subscales. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: Based on preoperative and 2-year postoperative responses to the KOOS questionnaires from a sample of 1904 patients undergoing ACL reconstruction, an aggregate score combining the KOOS, JR and the 4 KOOS Quality of Life subscale questions, termed the KOOSglobal, was developed. Psychometric properties of the KOOSglobal were then compared with those of the IKDC subjective score. Convergent validity between the KOOSglobal and IKDC was assessed with a Spearman correlation (ρ). Responsiveness of the 2 instruments was assessed by calculating the pre- to postoperative effect size and relative efficiency. Finally, the presence of a preoperative floor or postoperative ceiling effect was defined with the threshold of 15% of patients reporting either the worst possible (0 for KOOSglobal and IKDC) or the best possible (100 for KOOSglobal and IKDC) scores, respectively. Results: The newly developed KOOSglobal was responsive after ACL reconstruction and demonstrated convergent validity with the IKDC. The KOOSglobal significantly correlated with the IKDC scores (ρ = 0.91, P < .001), explained 83% of the variability in IKDC scores, and was similarly responsive (relative efficiency = 0.63). While there was a higher rate of perfect postoperative scores with the KOOSglobal (213 of 1904, 11%) than with the IKDC (6%), the KOOSglobal was still below the 15% ceiling effect threshold. Conclusion: The large ceiling effects limit the ability to use several of the KOOS subscales with the younger, more active ACL population. However, by creating an aggregate score from the KOOS, JR and 4 KOOS Quality of Life subscale questions, the 11-item KOOSglobal offers a responsive PRO tool after ACL reconstruction that converges with the information captured with the IKDC. Also, by offering the ability to calculate multiple scores from a single questionnaire, the KOOSglobal may provide the orthopaedic community a single PRO platform to be used across knee-related subspecialties. Registration: NCT00478894 ( ClinicalTrials.gov identifier).

Background: Anterior cruciate ligament (ACL) reconstruction can effectively return athletes to the playing field, but they are still at risk of developing posttraumatic osteoarthritis (PTOA). No studies have used multivariable analysis to evaluate the predictors of radiographic PTOA in the lateral compartment of the knee at short-term follow-up after ACL reconstruction. Purpose: To determine the predictors of radiographic joint space narrowing in the lateral compartment 2 to 3 years after ACL reconstruction in a young, active cohort. Study Design: Cohort study; Level of evidence, 2. Methods: A nested cohort of 358 patients from the Multicenter Orthopaedic Outcomes Network (MOON) prospective cohort who were aged ≤33 years, were injured playing a sport, and had never undergone surgery on the contralateral knee were followed up 2 years after ACL reconstruction with questionnaires and with weightbearing knee radiographs using the metatarsophalangeal (MTP) joint technique. The joint space width in the lateral compartment was measured using a semiautomatic computerized method, and multivariable predictive modeling was used to evaluate the relationship between meniscus treatment, cartilage injury, graft type, and joint space while adjusting for age, sex, body mass index, and Marx activity score. Results: The mean lateral joint space width was 0.11 mm narrower on the ACL-reconstructed knee compared with the contralateral healthy knee (7.69 mm vs 7.80 mm, respectively; P < .01). Statistically significant predictors of a narrower joint space width on the ACL-reconstructed knee included lateral meniscectomy ( P < .001) and a Marx activity score less than 16 points ( P < .001). Conclusion: This study identifies lateral meniscectomy and a lower baseline Marx activity score to be predictors of radiographic joint space narrowing in the lateral compartment 2 to 3 years after ACL reconstruction in young, active patients without a prior knee injury.

Background:When meniscal repair is performed during anterior cruciate ligament (ACL) reconstruction (ACLR), the effect of ACL graft type on meniscal repair outcomes is unclear.Hypothesis:The authors hypothesized that meniscal repairs would fail at the lowest rate when concomitant ACLR was performed with bone--patellar tendon--bone (BTB) autograft.Study Design:Cohort study; Level of evidence, 3.Methods:Patients who underwent meniscal repair at primary ACLR were identified from a longitudinal, prospective cohort. Meniscal repair failures, defined as any subsequent surgical procedure addressing the meniscus, were identified. A logistic regression model was built to assess the association of graft type, patient-specific factors, baseline Marx activity rating score, and meniscal repair location (medial or lateral) with repair failure at 6-year follow-up.Results:A total of 646 patients were included. Grafts used included BTB autograft (55.7%), soft tissue autograft (33.9%), and various allografts (10.4%). We identified 101 patients (15.6%) with a documented meniscal repair failure. Failure occurred in 74 of 420 (17.6%) isolated medial meniscal repairs, 15 of 187 (8%) isolated lateral meniscal repairs, and 12 of 39 (30.7%) of combined medial and lateral meniscal repairs. Meniscal repair failure occurred in 13.9% of patients with BTB autografts, 17.4% of patients with soft tissue autografts, and 19.4% of patients with allografts. The odds of failure within 6 years of index surgery were increased more than 2-fold with allograft versus BTB autograft (odds ratio = 2.34 [95% confidence interval, 1.12-4.92]; P = .02). There was a trend toward increased meniscal repair failures with soft tissue versus BTB autografts (odds ratio = 1.41 [95% confidence interval, 0.87-2.30]; P = .17). The odds of failure were 68% higher with medial versus lateral repairs ( P < .001). There was a significant relationship between baseline Marx activity level and the risk of subsequent meniscal repair failure; patients with either very low (0-1 points) or very high (15-16 points) baseline activity levels were at the highest risk ( P = .004).Conclusion:Meniscal repair location (medial vs lateral) and baseline activity level were the main drivers of meniscal repair outcomes. Graft type was ranked third, demonstrating that meniscal repairs performed with allograft were 2.3 times more likely to fail compared with BTB autograft. There was no significant difference in failure rates between BTB versus soft tissue autografts.Registration:NCT00463099 (ClinicalTrials.gov identifier).

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 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.

Background: Injuries to the posterolateral corner (PLC) may occur concurrently with anterior cruciate ligament (ACL) injury. Purpose/Hypothesis: This study evaluated the outcomes of patients who underwent operative management of PLC injuries concurrently with ACL reconstruction in a prospective multicenter cohort. We hypothesized that there would be no differences in outcomes between patients who were treated with PLC repair and PLC reconstruction. Study Design: Cohort study; Level of evidence, 3. Methods: Patients undergoing ACL reconstruction were enrolled into a prospective longitudinal multicenter cohort between 2002 and 2008. Those with complete 6-year follow-up data (patient-reported outcomes and subsequent surgery information) were identified. Excluded from the study were patients with posterior cruciate ligament injuries. Patients who underwent PLC repair were compared with those who underwent PLC reconstruction with regard to interval from injury to surgery, need for revision surgery, and long-term outcomes at 6 years. Results: During the identified time frame, 3026 identified patients underwent primary ACL reconstruction; 34 (1.1%) also underwent concurrent PLC surgery (15 repairs, 19 reconstructions [18 allografts, 1 autograft]). With the numbers available, we did not detect significant differences between groups regarding the rate of meniscal or chondral injuries. Median time to PLC reconstruction was 121 days as compared with 19 days for concurrent ACL reconstruction and PLC repair ( P = .01). There were no between-group differences in Marx activity scores prior to surgery ( P = .4). At 6-year follow-up, there were no between-group differences in Knee injury and Osteoarthritis Outcome Score ( P = .36-.83) or International Knee Documentation Committee score ( P = .84); however, patients treated with PLC reconstructions had lower Marx activity scores (4.1 vs 9.4; P = .02). There was 1 ACL revision in the PLC reconstruction group, and 1 of the PLC repairs was revised to a reconstruction during the follow-up period. Conclusion: Good outcomes were achieved at 6-year follow-up with both repair and reconstruction of PLC injuries treated concurrently with ACL reconstruction. The PLC reconstruction group had lower activity levels 6 years after surgery. The present data suggest that, for appropriately selected patients undergoing acute surgical treatment of combined ACL and PLC injuries, PCL repair can achieve good long-term outcomes.

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

Background: Most surgeons believe that graft choice for anterior cruciate ligament (ACL) reconstruction is an important factor related to outcome; however, graft choice for revision may be limited due to previously used grafts. Hypotheses: Autograft use would result in increased sports function, increased activity level, and decreased osteoarthritis symptoms (as measured by validated patient-reported outcome instruments). Autograft use would result in decreased graft failure and reoperation rate 2 years after revision ACL reconstruction. Study Design: Cohort study; Level of evidence, 2. Methods: Patients undergoing revision ACL reconstruction were identified and prospectively enrolled by 83 surgeons at 52 sites. Data collected included baseline demographics, surgical technique, pathologic abnormalities, and the results of a series of validated, patient-reported outcome instruments (International Knee Documentation Committee [IKDC], Knee injury and Osteoarthritis Outcome Score [KOOS], Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], and Marx activity rating score). Patients were followed up at 2 years and asked to complete the identical set of outcome instruments. Incidences of additional surgery and reoperation due to graft failure were also recorded. Multivariate regression models were used to determine the predictors (risk factors) of IKDC, KOOS, WOMAC, Marx scores, graft rerupture, and reoperation rate at 2 years after revision surgery. Results: A total of 1205 patients (697 [58%] males) were enrolled. The median age was 26 years. In 88% of patients, this was their first revision, and 341 patients (28%) were undergoing revision by the surgeon who had performed the previous reconstruction. The median time since last ACL reconstruction was 3.4 years. Revision using an autograft was performed in 583 patients (48%), allograft was used in 590 (49%), and both types were used in 32 (3%). Questionnaire follow-up was obtained for 989 subjects (82%), while telephone follow-up was obtained for 1112 (92%). The IKDC, KOOS, and WOMAC scores (with the exception of the WOMAC stiffness subscale) all significantly improved at 2-year follow-up ( P < .001). In contrast, the 2-year Marx activity score demonstrated a significant decrease from the initial score at enrollment ( P < .001). Graft choice proved to be a significant predictor of 2-year IKDC scores ( P = .017). Specifically, the use of an autograft for revision reconstruction predicted improved score on the IKDC ( P = .045; odds ratio [OR] = 1.31; 95% CI, 1.01-1.70). The use of an autograft predicted an improved score on the KOOS sports and recreation subscale ( P = .037; OR = 1.33; 95% CI, 1.02-1.73). Use of an autograft also predicted improved scores on the KOOS quality of life subscale ( P = .031; OR = 1.33; 95% CI, 1.03-1.73). For the KOOS symptoms and KOOS activities of daily living subscales, graft choice did not predict outcome score. Graft choice was a significant predictor of 2-year Marx activity level scores ( P = .012). Graft rerupture was reported in 37 of 1112 patients (3.3%) by their 2-year follow-up: 24 allografts, 12 autografts, and 1 allograft and autograft. Use of an autograft for revision resulted in patients being 2.78 times less likely to sustain a subsequent graft rupture compared with allograft ( P = .047; 95% CI, 1.01-7.69). Conclusion: Improved sports function and patient-reported outcome measures are obtained when an autograft is used. Additionally, use of an autograft shows a decreased risk in graft rerupture at 2-year follow-up. No differences were noted in rerupture or patient-reported outcomes between soft tissue and bone–patellar tendon–bone grafts. Surgeon education regarding the findings of this study has the potential to improve the results of revision ACL reconstruction.

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 $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 $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.

Background: Identifying risk factors for inferior outcomes after anterior cruciate ligament reconstruction (ACLR) is important for prognosis and future treatment. Hypothesis: Articular cartilage lesions and meniscus tears/treatment would predict International Knee Documentation Committee (IKDC) score, Knee injury and Osteoarthritis Outcome Score (KOOS) (all 5 subscales), and Marx activity level at 6 years after ACLR. Study Design: Cohort study (prognosis); Level of evidence, 1. Methods: Between 2002 and 2004, a total of 1512 ACLR patients were prospectively enrolled and followed longitudinally, with the IKDC, KOOS, and Marx activity score completed at entry, 2 years, and 6 years. A logistic regression model was built incorporating variables from patient demographics, surgical technique, articular cartilage injuries, and meniscus tears/treatment to determine the predictors (risk factors) of IKDC and KOOS scores and Marx activity level at 6 years. Results: A minimum follow-up on 86% (1307/1512) of the cohort was completed at 6 years. The cohort was 56% male and had a median age of 23 years at the time of enrollment, with 76% reporting a noncontact injury mechanism. Incidence of concomitant injury at the time of surgery consisted of the following: articular cartilage (medial femoral condyle [MFC], 25%; lateral femoral condyle [LFC] 20%; medial tibial plateau [MTP], 6%; lateral tibial plateau [LTP], 12%; patella, 20%; trochlear, 9%) and meniscus (medial, 38%; lateral, 46%). Both articular cartilage lesions and meniscus tears were significant predictors of 6-year outcomes on the IKDC and KOOS. Grade 3 or 4 articular cartilage lesions (excluding patella) significantly reduced IKDC and KOOS scores at 6 years. The IKDC demonstrated worse outcomes with the presence of a grade 3 or 4 chondral lesion on the MFC, MTP, and LFC. Likewise, the KOOS score was negatively affected by cartilage injury. The sole significant predictor of reduced Marx activity level was the presence of a grade 4 lesion on the MFC. Lateral meniscus repairs did not correlate with inferior results, but medial meniscus repairs predicted worse IKDC and KOOS scores. Lateral meniscus tears left alone significantly improved prognosis. Small partial meniscectomies (50%) on either the medial or lateral menisci improved prognosis. Analogous to previous studies, other significant predictors of lower outcome scores were lower baseline scores, higher body mass index, lower education level, smoking, and anterior cruciate ligament revisions. Conclusion: Both articular cartilage injury and meniscus tears/treatment at the time of ACLR were significant predictors of IKDC and KOOS scores 6 years after ACLR. Similarly, having a grade 4 MFC lesion significantly reduced a patient’s Marx activity level score at 6 years.

Objectives: Multiple studies have shown patients are susceptible to post-traumatic osteoarthritis (PTOA) after anterior cruciate ligament (ACL) injury even with ACL reconstruction (ACLR). Prospective studies using multivariate analysis to identify risk factors for PTOA are lacking. This study aims to identify baseline predictors of radiographic PT OA after ACLR at an early time point and hypothesizes that meniscal injury and cartilage lesions will be associated with worse radiographic OA using the Osteoarthritis Research Society International (OARSI) atlas criteria. Methods: 421 patients who underwent ACLR returned onsite for standardized posteroanterior metatarsophalangeal radiographs a minimum of 2 years after surgery. At baseline, demographics, graft type, meniscal status/treatment, and cartilage status were collected. OARSI atlas criteria were used to grade all knee radiographs. Multivariable ordinal regression models identified baseline predictors of radiographic OARSI grades at follow-up. Results: The mean age was 19.8 years with 51.3% females. Higher age (odds ratio (OR) 1.06) and BMI (OR 1.05) were statistically significantly associated with higher OARSI grade in the medial compartment. Patients with a meniscal repair and a partial meniscectomy had statistically significantly higher OARSI grades in the medial compartment (meniscal repair OR 1.92 and meniscectomy OR 2.11) and in the lateral compartment (meniscal repair OR 1.96 and meniscectomy OR 2.97). Graft type, cartilage lesion, sex, and Marx activity scales had no significant association with OARSI grade. Conclusion: Older patients with a higher BMI who have an ACL tear with concurrent meniscal tear requiring partial meniscectomy or meniscal repair should be advised of their increased risk of developing radiographic OA. Alternatively, patients with an ACL tear with an articular cartilage lesion can be reassured that they are not at increased risk of developing radiographic knee OA at 2-3 years following ACLR.

Background:Septic arthritis is a rare but potentially devastating complication of anterior cruciate ligament (ACL) reconstruction surgery. Several studies, including one by this group, have reported short- and medium-term outcomes, but to our knowledge there are no long-term follow-up studies.Hypothesis:Postoperative septic arthritis after ACL reconstruction surgery will lead to diminished long-term outcomes compared with surgery without infectious complications, likely related to the development of arthritis.Study Design:Case series; Level of evidence, 4.Methods:Four of 831 consecutive patients undergoing arthroscopically guided ACL reconstruction surgeries performed by 1 surgeon were previously reported on by this group at an average follow-up of 36 months. These same patients were contacted and reevaluated. Each patient underwent a physical examination, functional testing, and subjective evaluations with the SF-36, Lysholm, International Knee Documentation Committee (IKDC), and Tegner activity scale scores. Plain film radiographs and magnetic resonance imaging (MRI) scans were analyzed by 2 musculoskeletal radiologists.Results:Average follow-up time for this study was 17.9 years, and average age was 44.3 years. No other injuries or surgeries had occurred from the time of the previous study. Each patient had a decline in SF-36, Lysholm, and IKDC score, and the average Tegner score was unchanged. Average vertical hop test performance and Biodex dynamometry were both improved. The average side-to-side displacement measured via the KT-1000 arthrometer was increased. Radiographic and MRI studies revealed progression of arthritis in all patients and ACL graft rupture in 1 patient.Conclusion:Patients who develop septic arthritis as a complication of ACL reconstruction surgery have diminished long-term subjective, functional, and radiographic outcomes compared with historical reports of uncomplicated cases, likely related to pain from advanced arthritis. As compared with their own earlier follow-up, these patients had declines in pain-related subjective measures but remained stable or improved in both functional testing and activity-related subjective scales.

Background: Tearing an anterior cruciate ligament (ACL) graft is a devastating occurrence after ACL reconstruction (ACLR). Identifying and understanding the independent predictors of ACLR graft failure is important for surgical planning, patient counseling, and efforts to decrease the risk of graft failure. Hypothesis: Patient and surgical variables will predict graft failure after ACLR. Study Design: Prospective cohort study. Methods: A multicenter group initiated a cohort study in 2002 to identify predictors of ACLR outcomes, including graft failure. First, to control for confounders, a single surgeon’s data (n = 281 ACLRs) were used to develop a multivariable regression model for ACLR graft failure. Evaluated variables were graft type (autograft vs allograft), sex, age, body mass index, activity at index injury, presence of a meniscus tear, and primary versus revision reconstruction. Second, the model was validated with the rest of the multicenter study’s data (n = 645 ACLRs) to evaluate the generalizability of the model. Results: Patient age and ACL graft type were significant predictors of graft failure for all study surgeons. Patients in the age group of 10 to 19 years had the highest percentage of graft failures. The odds of graft rupture with an allograft reconstruction are 4 times higher than those of autograft reconstructions. For each 10-year decrease in age, the odds of graft rupture increase 2.3 times. Conclusion: There is an increased risk of ACL graft rupture in patients who have undergone allograft reconstruction. Younger patients also have an increased risk of ACL graft failure. Clinical Relevance: Given these risks for ACL graft rupture, allograft ACLRs should be performed with caution in the younger patient population.

Background: The predictors of anterior cruciate ligament reconstruction (ACLR) outcome at 6 years as measured by validated patient-based outcome instruments are unknown. Hypothesis: Certain variables evaluated at the time of ACLR will predict return to sports function (as measured by the International Knee Documentation Committee [IKDC] questionnaire and the Knee injury and Osteoarthritis Outcome Score [KOOS] Sports and Recreation subscale), knee-related quality of life (KOOS Knee Related Quality of Life subscale), and activity level (Marx Activity Scale). Potential predictor variables include demographic factors, surgical technique and graft choice for ACLR, and intra-articular injuries and treatment. Study Design: Cohort study; Level of evidence, 2. Methods: All patients with unilateral ACLRs from 2002 currently enrolled in the MOON (Multicenter Orthopaedic Outcomes Network) cohort were evaluated. Patients completed the validated outcome instruments preoperatively. Physicians documented intra-articular pathologic abnormalities, treatment, and surgical techniques used at the time of surgery. At 2 and 6 years postoperatively, patients completed the same validated outcome instruments. Results: Follow-up was obtained at 2 years (88%) and at 6 years (84%). The cohort was 57% male with a median age of 23 years at enrollment. The ability to perform sports function was maintained at 6 years, but the Marx activity level continued to decline from baseline. Revision ACLR and use of allograft predicted worse outcomes on the IKDC and both KOOS subscales. Lateral meniscus treatment, smoking status, and body mass index at baseline were each predictors on 2 of 3 scales. The predictors of lower activity level were revision ACLR and female sex. Conclusion: Six years after ACLR, patients could perform sports-related functions and maintain a high knee-related quality of life similar to their 2-year level, although their physical activity level (Marx) dropped over time. Choosing autograft rather than allograft, not smoking, and having normal body mass index are advised to improve long-term outcomes.

Background Meniscal repair is performed in an attempt to prevent posttraumatic arthritis resulting from meniscal dysfunction after meniscal tears. The socioeconomic implications of premature arthritis are significant in the young patient population. Investigations and techniques focusing on meniscus preservation and healing are now at the forefront of orthopaedic sports medicine. Hypothesis Concomitant meniscal repair with anterior cruciate ligament reconstruction is a durable and successful procedure at 2-year follow-up. Study Design Case series; Level of evidence, 4. Methods All unilateral primary anterior cruciate ligament reconstructions entered in 2002 in a cohort who had meniscal repair at the time of anterior cruciate ligament reconstruction were evaluated. Validated patient-oriented outcome instruments were completed preoperatively and then again at the 2-year postoperative time point. Reoperation after the index procedure was also documented and confirmed by operative reports. Results A total of 437 unilateral primary anterior cruciate ligament reconstructions were performed with 82 concomitant meniscal repairs (54 medial, 28 lateral) in 80 patients during the study period. Patient follow-up was obtained on 94% (77 of 82) of the meniscal repairs, allowing confirmation of meniscal repair success (defined as no repeat arthroscopic procedure) or failure. The overall success rate for meniscal repairs was 96% (74 of 77 patients) at 2-year follow-up. Conclusion Meniscal repair is a successful procedure in conjunction with anterior cruciate ligament reconstruction. When confronted with a “repairable” meniscal tear at the time of anterior cruciate ligament reconstruction, orthopaedic surgeons can expect an estimated >90% clinical success rate at 2-year follow-up using a variety of methods as shown in our study.

Background Acute and chronic cartilage injury of the knee has an important impact on prognosis. The validity of the classification of such injuries is critical for prospective multicenter studies. The agreement among multiple surgeons at different institutions for articular cartilage lesions has not been established. Hypothesis Arthroscopic classification of articular cartilage lesions is reliable and reproducible and can be used for multicenter studies involving multiple surgeons. Study Design Cohort study (diagnosis); Level of evidence, 1. Methods A total of 6 surgeons from 5 centers reviewed 31 videos of articular cartilage lesions. With grade 2 and grade 3 combined for the analysis, observed agreement ranged from 81% to 94%, and kappa ranged from 0.34 to 0.87. An additional 22 videos comprising grade 2 and grade 3 lesions were analyzed, and the observed agreement was 80%, with an overall kappa of 0.47. Conclusion Arthroscopic grading of articular cartilage lesions is reproducible among surgeons at different centers. Clinical Relevance Articular cartilage lesions can be reliably classified among surgeons at different sites. Such reliability is important for multicenter clinical research studies involving arthroscopic knee surgery.

This study characterized knee joint kinetics during a golf swing and determined the influence of shoe type and golfer skill on the peak knee joint loads. Thirteen golfers each hit a golf ball using a five iron under two footware conditions: spiked and spikeless golf shoes. Data from a video-based motion capture system and force plates were used to compute the knee joint kinetics. Mean peak forces and moments differed significantly between the lead and trail knees, but these peak loads were not significantly affected by shoe type. Only the lead knee flexion and internal rotation moments were significantly correlated to skill level. The magnitude of some of the peak loads at the knee during the golf swing approached those reached during activities prohibited until late-stage knee rehabilitation. We concluded the following: The type of shoe worn and the skill level of the golfer need not be considered in deciding time to return to golfing; however, the leg that is recovering from surgery or injury should be considered. The most stressful phase of the golf swing, relative to the knee, is the downswing. There is probably no “normal” swing; each golfer seems to possess consistent, characteristic, patterns of knee loading.

To define the biomechanical effects of total lateral meniscectomy and of subsequent lateral meniscal al lograft replacement on load transmission and distribu tion across the human knee, we mounted 10 fresh- frozen, young human cadaveric knees on a mechanical testing system. Peak pressure and contact area profiles were determined at 0°, 30°, and 60° of knee flexion using pressure-sensitive film and a den sitometer. Load transmission profiles were determined for each knee in a sequential test order: 1)intact knee, 2) after lateral meniscectomy, 3) after implantation of size-matched meniscal allograft fixed with bone plugs, and 4) after release of the anterior and posterior horn attachments of the allograft. Total lateral meniscec tomy resulted in a 45% to 50% decrease in total con tact area. Allograft replacement increased total contact area by 42% to 65% as compared with total meniscec tomy at all flexion angles. After release of the anterior and posterior horn attachments, contact area was identical to that after total meniscectomy. Total lateral meniscectomy resulted in a 235% to 335% increase in peak local contact pressure. Allograft replacement de creased these pressures by 55% to 65% at all flexion angles, but they remained significantly greater than those in the intact state. After release of the anterior and posterior horn attachments, contact pressures were identical to those after total meniscectomy. Com pared with total meniscectomy, meniscal allograft transplantation significantly increases contact area and decreases peak local contact pressures, but any bio mechanical advantages are lost without bone plug fix ation of the anterior and posterior horns.

Objectives: Identifying risk factors for inferior outcomes after ACL reconstruction (ACLR) is important for prognosis and future treatment. Study goal: analyze a sufficiently large enough cohort to evaluate whether articular cartilage and meniscal variables are predictive of three validated sports outcome instruments. We hypothesized that articular cartilage lesions and meniscus tears/treatment would be predictors of IKDC, KOOS (all 5 subscales), and Marx Activity Level at 6 years after ACLR. Methods: From 2002-2004, 1411 ACLR subjects were prospectively enrolled and followed longitudinally with the IKDC, KOOS, and Marx completed at entry, 2 and 6 years. A logistic multivariable model consisted of patient demographics, surgical technique variables, and articular cartilage injuries and meniscus tears/treatment for determining predictors (risk factors) of IKDC, KOOS, and Marx at 6 years. Results: We completed a minimum follow-up on 93% (1307/1411) of our cohort at 6 years. Baseline results: 56% male, median age 23 years, 75% with non-contact injury mechanism, articular cartilage pathology (MFC-25%, LFC-20%, MTP-6%, LTP-12%, patella-20%, and trochlear-9%), and meniscal pathology (medial-38%, lateral-46%). Both articular cartilage lesions and meniscal tears significantly predicted 6 year outcomes on IKDC and KOOS (Table 1). Grade 3 or 4 articular cartilage lesions (excluding patella) significantly reduced IKDC and KOOS scores at 6 years. Figure 1 focuses on IKDC and demonstrates worse outcomeswith chondral injuries on the MFC, MTP, and LFC. Likewise, KOOS was negatively affected by cartilage injury. The sole significant predictor of reduced Marx activity was the presence of a grade 4 lesion on the MFC. Lateral meniscus repairs did not correlate with inferior results, but medial meniscus repairs predicted worse IKDC and KOOS scores. Lateral meniscus tears left alone significantly improved prognosis. Small partial meniscectomies (50%) improved prognosis. Analogous to previous studies, other significant predictors of worse outcome scores were lower baseline scores, higher BMI, lower education level, smoking, and revisions. Conclusion: Both articular cartilage injury and meniscal tears/treatment at the time of ACLR were significant predictors of both IKDC and KOOS scores at 6 year follow-up. Similarly, having a grade 4 MFC lesion significantly reduced a patient’s Marx activity level score at 6 years.

Ballet dancers are vulnerable to various stress-related injuries; foot and ankle injuries are the most common. This study determined if the pressure across the foot could be more evenly distributed by wearing various modified technique shoes padded with PPT, Spenco, or Sorbathane, alone or in combinations. A professional ballet dancer performed a jump by taking a single step on his left foot, jumping and landing with his right foot on the force and pressure plates with each modified shoe plus one unmodified shoe. The results of this study revealed: (1) total force cannot be reduced, (2) center of gravity and the majority of the pressure is maintained over the first and second metatarsal heads, and (3) the modified technique shoe can more evenly distribute pressure to the medial arch and away from the toes, metatarsal heads, and heel.

Objectives: Meniscus tears frequently accompany acute anterior cruciate ligament ruptures. Management of meniscus tears is highly variable and includes repair, meniscectomy, and non-treatment of tears identified at the time of ACL reconstruction. The purpose of this study is to determine the rate of subsequent reoperation and clinical outcome of meniscal tears left in situ without treatment at the time of ACL reconstruction with a minimum follow-up of 6 years. Methods: Patients with meniscus tears left untreated at the time of primary ACL reconstruction were identified from a multicenter study group between 2002 and 2004 with minimum 6-year follow-up. Patient demographic variables, comorbidities, meniscus tear characteristics, and information on subsequent surgery were obtained. The primary endpoint of the study was need for reoperation for meniscal pathology. Univariate and multivariate analyses were used in order to determine patient demographic variables and meniscus tear characteristics that served as risk factors for reoperation. Results: There were 1440 primary ACL reconstructions performed during the timeframe of the study. There were 955 patients (66.3%) with concomitant meniscal tears identified. Of these, 143 (15.3%) had meniscal tears left in situ at the time of surgery. There were 11 patients (7.9%) who underwent reoperation for meniscal pathology within the same compartment as the meniscal tear left in situ (Table 1). Reoperation was performed more frequently for medial meniscus tears as compared to lateral meniscus tears (17.6% vs. 4.3%, p = 0.048). Medial meniscus tears and tears ≥10 mm in length were identified as risk factors for reoperation. Conclusion: Lateral and medial meniscus tears left in situ at the time of ACL reconstruction did not require reoperation at minimum 6-year follow-up in 95.7% and 82.4% of patients, respectively. Our results suggest that surgeons should consider alternative treatment for medial meniscus tears and tears ≥ 10 mm in length at the time of ACL reconstruction.