Analysis of Revision Anterior Cruciate Ligament Reconstruction according to the combined injury, degenerative change, and MRI findings

Preservation of the MMPH and Status of the Notch Configurations Are Important Factors for Successful Revision ACL Reconstruction

OBJECTIVE

The aim of this study was to identify the differences in anatomical factors between the patients who underwent revision and primary anterior cruciate ligament reconstructions (ACLR) and compare the outcomes between the 2 surgeries.

DESIGN

Retrospective cohort study.

SETTING

Single institution tertiary academic center between 2014 and 2020.

PATIENTS

A total of 84 matched patients who underwent revision (group I) or primary ACLR (group II).

INTERVENTIONS

Radiological evaluations were performed using side-to-side differences (SS-D), femorotibial angle, and posterior tibial slope. The medial meniscus posterior horn status as width (MMPHW), medial tibial plateau width (MTPW), notch configurations, tunnel positions, and sagittal graft angle were measured using 3D-CT and magnetic resonance imaging (MRI).

MAIN OUTCOME MEASURES

Graft signals were assessed using MRI. The clinical outcomes were assessed.

RESULTS

Group I showed larger SS-D and higher mean Howell grade of anterior cruciate ligament (ACL) graft than group II ( P = 0.002 and P = 0.004, respectively). Multivariate regression analyses showed that the decreased MMPHW/MTPW ratio ( P = 0.010) and notch width index ( P < 0.007) were significantly independent factors associated with the higher Howell grade of ACL grafts. The decreased MMPHW/MTPW ratio ( P < 0.001) was a significantly independent factor associated with larger SS-D. In the subgroup analysis, all patients in the notchplasty group showed wider notches postoperatively ( P < 0.001).

CONCLUSIONS

Revision ACLRs resulted in worse ACL signal intensity and stability outcome. The results of this study suggest that it may be important to preserve the MMPHW as much as possible and check notch configurations, especially during a revision ACLR.

Arthroscopic Bone Graft Technique for Two-Stage Revision Anterior Cruciate Ligament Reconstruction

Revision anterior cruciate ligament reconstruction is an increasingly common procedure, with 2-stage surgery often required to address large bone defects and malpositioned tunnels. The arthroscopic bone grafting technique described herein uses morselized allograft bone to provide reproducible fill of asymmetrical bone defects without autograft harvest or additional loss of native bone. The second stage of the anterior cruciate ligament reconstruction can typically proceed 6 months following bone grafting.

Revision ACL Reconstruction: Principles and Practice

INTRODUCTION

The incidence of anterior cruciate ligament reconstruction (ACLR) surgeries is increasing and so is the number of revision surgeries for a failed ACLR. The spectrum of ACL failure includes symptoms of recurrent instability, pain, and/or stiffness.

DISCUSSION

Factors contributing to ACL failure may be classified as patient-related, surgeon-related, and biological factors. Of these, tunnel malposition and recurrent trauma are the most common causes. Detailed patient assessment, imaging, and studying details of the index surgery are critical prior to planning revision surgery. Infection has to be ruled out prior to planning any reconstructive surgical procedure. Osseous malalignment in the coronal or sagittal planes would also need correction along with or prior to revision ACL surgery. Revision ACL reconstruction maybe performed as a one-stage or two-stage procedure. Severe tunnel dilatation, infection, or arthrofibrosis necessitates a two-stage approach. Autografts are preferred for revision ACL due their lesser re-tear rates and better outcomes. Associated meniscus tears and cartilage injuries are more common in revision than in primary surgery and need to be managed appropriately. Extra-articular reconstruction for controlling anterolateral instability is frequently required as well.

CONCLUSION

Revision ACL reconstruction is a complex undertaking due to limited graft options, compromised anatomy and high frequency of associated injuries. Patient expectations must be tempered because functional outcomes and return to pre-injury sports are inferior to a primary surgery.

Primary Versus Revision Anterior Cruciate Ligament Reconstruction: Patient Demographics, Radiographic Findings, and Associated Lesions

PURPOSE

The purpose of this study was to evaluate the differences in intra-articular pathology, demographic characteristics, and radiographic characteristics of the knee associated with primary anterior cruciate ligament reconstruction (ACLR) versus revision ACLR at the time of initial presentation with either a native anterior cruciate ligament tear or an anterior cruciate ligament graft tear. Secondarily, we aimed to investigate risk factors for concomitant medial and lateral meniscal tears and cartilage injuries at the time of ACLR.

METHODS

This was a retrospective review of patients who underwent primary or revision ACLR by a single surgeon. The exclusion criteria were as follows: skeletally immature patients; patients with an intra-articular fracture; patients with an ipsilateral knee infection; or patients who underwent an osteotomy, cartilage restoration procedure, or meniscal transplantation either previously or concomitantly with the ACLR. Detailed patient demographic data, radiographic long-standing alignment, tibial slope, and intraoperative findings including articular cartilage injury grade and meniscus integrity were documented at surgery.

RESULTS

There were 487 patients included in this study (363 with primary ACLR and 124 with revision ACLR). There were no significant differences in age (P = .119), sex (P = .917), body mass index (P = .468), allograft versus autograft reconstruction (P = .916), or prevalence of meniscal tears (P = .142) between the primary and revision groups. Patients who underwent revision ACLR had a significantly increased medial tibial slope (P = .048) and a higher prevalence of chondral defects on both the medial (P < .001) and lateral (P = .003) femoral condyles when compared with primary ACLR patients. Logistic regression showed that a decreased tibial slope was correlated with femoral medial-sided chondral injuries and that varus or valgus coronal-plane malalignment was correlated with lateral meniscal tears in both groups.

CONCLUSIONS

The findings of this study show that patients undergoing a revision ACLR have significantly more chondral lesions, as well as higher-grade chondral lesions, at the time of presentation. Furthermore, coronal malalignment and a decreased tibial slope may contribute to injury patterns of the lateral meniscus and medial compartment cartilage, respectively. LEVEL OF EVIDENCE: Level III, retrospective case-control study.

Influence of Meniscal and Chondral Lesions on Patient-Reported Outcomes After Primary Anterior Cruciate Ligament Reconstruction at 2-Year Follow-up

Background:

Meniscal and chondral lesions are commonly associated with anterior cruciate ligament (ACL) tears, and these lesions may play a role in patient outcomes after ACL reconstruction.

Purpose:

To determine the effects of the presence and location of meniscal and chondral lesions at the time of ACL reconstruction on patient-reported outcomes at a minimum 2-year follow-up.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Patients with no prior knee surgery who underwent primary ACL reconstruction by a single surgeon between 2010 and 2014 were included in this study. Those meeting inclusion criteria were divided into the following groups based on the arthroscopic diagnosis: patients without concomitant meniscal or chondral lesions, patients with isolated meniscal lesions, patients with isolated chondral lesions, and patients with both chondral and meniscal lesions. Patient-reported outcomes (Short Form–12 [SF-12] physical component summary [PCS] and mental component summary [MCS], Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], and Lysholm scale) were assessed at a minimum of 2 years from the index surgery.

Results:

A total of 151 patients met the inclusion criteria and were included in the study. The mean age at the time of surgery was 36.2 years (range, 14-73 years), and the mean follow-up was 3.2 years (range, 2.0-5.6 years). At the time of surgery, 33 (22%) patients had no concomitant lesions and served as the control group, 63 (42%) patients had isolated meniscal lesions, 21 (14%) patients had isolated chondral lesions, and 34 (22%) patients had both chondral and meniscal lesions. There was significant improvement in all outcome scores postoperatively for the 3 groups (P < .05 for all outcome scores). The presence of a meniscal tear and laterality of the meniscal lesion did not have a negative effect on any postoperative outcome scores. Patients with isolated chondral lesions had significantly lower postoperative WOMAC scores compared with patients without chondral lesions (P < .05). No significant differences were found for all other scores. Patients with patellofemoral chondral lesions had significantly lower postoperative SF-12 PCS and Lysholm scores than patients with tibiofemoral chondral lesions (P < .05).

Conclusion:

Patients with ACL tears achieved improved functional scores at a mean 3.2 years after ACL reconstruction. While meniscal lesions did not affect postoperative outcomes in the short term, chondral lesions were identified as a predictor for worse outcomes.

What Is the Mid-term Failure Rate of Revision ACL Reconstruction? A Systematic Review

BACKGROUND

When anterior cruciate ligament (ACL) reconstruction fails, a revision procedure may be performed to improve knee function, correct instability, and allow return to activities. The results of revision ACL reconstruction have been reported to produce good but inferior patient-reported and objective outcomes compared with primary ACL reconstruction, but the degree to which this is the case varies widely among published studies and may be influenced by heterogeneity of patients, techniques, and endpoints assessed. For those reasons, a systematic review may provide important insights.

QUESTIONS/PURPOSES

In a systematic review, we asked: (1) What is the proportion of revision ACL reconstruction cumulative failures defined as rerupture or objective failure using prespecified clinical criteria at mean followup of at least 5 years? (2) What are the most common complications of revision ACL reconstruction?

METHODS

A systematic review was performed by searching PubMed/Medline, EMBASE, and CENTRAL. We included studies that reported the clinical evaluation of revision ACL reconstruction with Lachman test, pivot shift test, side-to-side difference with KT-1000/2000 arthrometer, and with a mean followup of at least 5 years. We excluded studies that incompletely reported these outcomes, that reported only reruptures, or that were not in the English language. Extracted data included the number of graft reruptures and objective clinical failure, defined as a knee that met one of the following endpoints: Lachman test Grade II to III, pivot shift Grade II to III, KT-1000/2000 > 5-mm difference, or International Knee Documentation Committee Grade C or D. For each study, we determined the proportion of patients who had experienced a rupture of the revision ACL graft as well as the proportion of patients who met one or more of our clinical failure endpoints. Those proportions were summed for each study to generate a percentage of patients who met our definition of cumulative failure. Complications and reoperations were recorded but not pooled as a result of inconsistency of reporting and heterogeneity of populations across the included studies. Of the 663 screened studies, 15 articles were included in the systematic review. Because one study reported two separate groups of patients with different treatments, 16 case series were considered in the evaluation.

RESULTS

The proportion of reruptures (range, 0%-25%) was > 5% in only four of 16 series and > 10% in only one of them. The objective clinical failures (range, 0%-82%) was > 5% in 15 of 16 series and > 10% in 12 of them. The proportion exceeded 20% in five of 16 series. The cumulative failures (range, 0%-83%) was > 5% in all except one series and > 10% in 12 of 16 series; five series had a cumulative failure proportion > 20%. The most frequent complications were knee stiffness and anterior knee pain, whereas reoperations were primarily débridement and meniscectomies.

CONCLUSIONS

Considering rerupture alone as a failure endpoint in patients who have undergone revision ACL reconstruction likely underestimates the real failure rate, because the percentage of failures noticeably increases when objective criteria are also considered. Whether patient-reported and subjective scores evaluating knee function, level of activity, satisfaction, and pain might also contribute to the definition of failure may be the focus of future studies.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Revision anterior cruciate ligament reconstruction: clinical outcome and evidence for return to sport

PURPOSE

An increasing number of patients undergo revision anterior cruciate ligament (ACL) reconstruction, with the intention of returning to sport being a major indication. The aim of this study is to assess the available evidence for clinical improvement and return to sport, to understand the real potential of this procedure in regaining functional activity, and to facilitate improved counselling of patients regarding the expected outcome after revision ACL reconstruction.

METHODS

The search was conducted on the PubMed database. Articles reporting clinical results for revision ACL reconstruction were included. A meta-analysis was performed on return to sport, and results were compared to the literature on primary ACL reconstruction. Other specific clinical outcomes (Lysholm, Tegner, IKDC Objective scores) were also included in the meta-analysis.

RESULTS

Of the 503 identified records, a total of 59 studies involving 5365 patients were included in the qualitative data synthesis. Only 31 articles reported the rate of return to sport. Whereas 73 % of good objective results and satisfactory subjective results were documented, 57 % of patients did not return to the same level of sport activity, significantly inferior to that of a primary procedure.

CONCLUSION

The real potential of revision ACL reconstruction should not be overestimated due to the low number of patients able to return to their previous activity level, significantly inferior with respect to that reported for primary ACL reconstruction. This finding will help physicians in the clinical practice providing realistic expectations to the patients. Future studies should focus on participation-based outcome measures such as return to sport and in strategies to improve the results in terms of return to previous activities after revision ACL reconstruction.

LEVEL OF EVIDENCE

Systematic review and meta-analysis including Level IV studies, Level IV.

Variability of tunnel positioning in fluoroscopic-assisted ACL reconstruction

PURPOSE

Intraoperative fluoroscopy has been proposed as a feasible method to improve the accuracy of anatomical tunnel positioning. However, it has so far not been determined, whether this technique reduces the variability of tunnel positioning in a clinical set-up. Therefore, the purpose of this study was to determine the variability of tunnel positions applying intraoperative fluoroscopy.

METHODS

Femoral and tibial tunnel positions of 112 fluoroscopic ACL reconstruction cases were determined according to validated radiological measurement methods. Mean positions, standard deviations and ranges were calculated to determine the variability of the tunnel positions. Subgroup variability analysis was performed to analyse cases in which tunnel positions were corrected.

RESULTS

Applying intraoperative fluoroscopy, the variability of tunnel positions was found to be 3 % at the femur (range 15.4 %) and 2.3 % at the tibia (9.7 %). In 34 cases (30.0 %), non-satisfactory tunnel positions were identified and could be corrected achieving more accurate positions regarding to radiological parameters (14× femur, 16× tibia, 4× femur and tibia).

CONCLUSIONS

The results of the presented study indicate that intraoperative fluoroscopy allows to identify non-accurate tunnel positions regarding to radiological criteria. The determined low variability indicates that fluoroscopic-based ACL reconstruction can be recommended as a feasible, easy and effective adjunct that enables surgeons to create more consistent and reliable tunnel positions in ACL reconstruction.

LEVEL OF EVIDENCE

IV.

Association of Meniscal Status, Lower Extremity Alignment, and Body Mass Index With Chondrosis at Revision Anterior Cruciate Ligament Reconstruction

BACKGROUND

Knees undergoing revision anterior cruciate ligament reconstruction (rACLR) have a high prevalence of articular cartilage lesions.

HYPOTHESIS

The prevalence of chondrosis at the time of rACLR is associated with meniscal status and lower extremity alignment.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Data from the prospective Multicenter ACL Revision Study (MARS) cohort were reviewed to identify patients with preoperative lower extremity alignment films. Lower extremity alignment was defined by the weightbearing line (WBL) as a percentage of the tibial plateau width, while the chondral and meniscal status of each weightbearing compartment was recorded at the time of surgery. Multivariable proportional odds models were constructed and adjusted for relevant factors to examine which risk factors were independently associated with the degree of medial and lateral compartment chondrosis.

RESULTS

The cohort included 246 patients with lower extremity alignment films at the time of rACLR. Mean (±SD) patient age was 26.9 ± 9.5 years and body mass index (BMI) was 26.4 ± 4.6. The medial compartment had more chondrosis (grade 2/3, 42%; grade 4, 6.5%) than did the lateral compartment (grade 2/3, 26%; grade 4, 6.5%). Disruption of the meniscus was noted in 35% of patients on the medial side and 16% in the lateral side. The mean WBL was 0.43 ± 0.13. Medial compartment chondrosis was associated with BMI (P = .025), alignment (P = .002), and medial meniscal status (P = .001). None of the knees with the WBL lateral to 0.625 had grade 4 chondrosis in the medial compartment. Lateral compartment chondrosis was significantly associated with age (P = .013) and lateral meniscal status (P < .001). Subjects with "intact" menisci were found to decrease their odds of having chondrosis by 64% to 84%.

CONCLUSION

The status of articular cartilage in the tibiofemoral compartments at the time of rACLR is related to meniscal status. Lower extremity alignment and BMI are associated with medial compartment chondrosis.

Management of an Anterior Cruciate Ligament Tear in a 5 Year-Old Boy

PURPOSE

The purpose of this retrospective case report was to describe clinical decision making during the examination and treatment of a 5-year-old boy with an anterior cruciate ligament (ACL) tear.

KEY POINTS

A paucity of research exists for the management of ACL tears in children. A combination of manual therapy interventions initially, followed by a unique and comprehensive therapeutic exercise program, was implemented during the course of a 3-month treatment period. Improvements in range of motion, quadriceps strength, single-leg stance time, and the Knee Injury and Osteoarthritis Outcome Score were noted. At discharge, the patient safely returned to unrestricted home and school activities.

CONCLUSION

This case demonstrates successful management of a child after an ACL injury.

CLINICAL IMPLICATIONS

Clinicians are encouraged to implement sound clinical reasoning in the absence of well-established evidence when treating similar patients in their clinical practice.

Coronal limb alignment and indications for high tibial osteotomy in patients undergoing revision ACL reconstruction

BACKGROUND

Failed ACL reconstruction frequently is accompanied by irreparable medial meniscal tear and/or visible osteoarthritis (OA) in the medial tibiofemoral joint. Thus, assessment for the presence of varus malalignment is important in caring for patients in whom revision ACL reconstruction is considered.

QUESTIONS/PURPOSES

We determined whether patients undergoing revision ACL reconstruction (1) have more frequent varus malalignment coupled with more severe degrees of medial meniscal injury and/or medial tibiofemoral OA, and (2) would meet potential indications for high tibial osteotomy more frequently than patients undergoing primary ACL reconstruction.

METHODS

We compared 58 patients undergoing revision ACL reconstruction and 116 patients undergoing primary ACL reconstruction. The mechanical tibiofemoral angle and the weight loading line (%) of the knee were measured. Additionally, radiographic degrees of OA in the tibiofemoral joints, and meniscal conditions were assessed. Then, proportions of potential candidates for high tibial osteotomy between the two groups were compared based on the following indications: (1) weight loading line less than 5%, (2) weight loading line less than 25% and medial tibiofemoral OA Kellgren-Lawrence Grade 3 or greater, or (3) weight loading line less than 25% and Kellgren-Lawrence Grade 2 medial tibiofemoral OA plus subtotal or total medial meniscectomy status.

RESULTS

The revision ACL reconstruction group had more frequent varus malalignment in terms of proportion of knees with more varus mechanical tibiofemoral angle than varus 5° (19% versus 8%, p = 0.029) and knees with weight loading line less than 25% (22% versus 9%, p = 0.011). This group also had more frequent high-grade injury of the medial meniscus (34% versus 16%, p = 0.007) and tended to have more frequent higher-grade radiographic OA at the medial tibiofemoral joint (19% versus 9%, p = 0.076). The percentage of patients meeting potential indications for high tibial osteotomy was greater in this group (14% versus 2%, p = 0.003).

CONCLUSIONS

We found that many patients undergoing revision ACL surgery may be reasonable candidates for concurrent high tibial osteotomy to address concomitant alignment and OA issues in the medial compartment. However, whether that additional intervention is offset by added risk and morbidity should be the focus of a future study, as it cannot be answered by a study of this design.

Inferior results after revision ACL reconstructions: a comparison with primary ACL reconstructions

PURPOSE

Anterior cruciate ligament (ACL) ruptures are common, especially among young athletes, and such injuries may have considerable impact on both sport careers and everyday life. ACL reconstructions are successful for most patients, but some suffer from persistent giving-way symptoms and/or re-ruptures requiring revision surgery. The aim of this study was to evaluate the results after revision ACL reconstructions and compare them with the results in a control group consisting of primary ACL reconstructions.

METHODS

This retrospective study included 56 patients undergoing revision ACL reconstruction and 52 patients receiving primary ACL reconstructions. The follow-up evaluation included clinical examination, instrumented laxity testing, testing of muscle strength, Tegner activity score, Lysholm score, Knee injury and osteoarthritis outcome score (KOOS) and radiological grading of osteoarthritis.

RESULTS

The median time from the last ACL reconstruction to follow-up was 90 months in the revision ACL reconstruction group and 96 months in the primary ACL reconstruction group. The revision group had significantly inferior KOOS and Lysholm scores compared with the primary group. Patients in the revision group also showed greater laxity measured with the pivot shift test, a larger reduction in the Tegner activity score, reduced muscle strength in the injured knee, and more severe radiological osteoarthritis; however, no difference in anterior-posterior translation was found.

CONCLUSION

Inferior results were found on several of the testing parameters in the revision group compared with the primary group. Patients should receive this information prior to revision ACL reconstructions.

LEVEL OF EVIDENCE

III.

Incidence and outcome after revision anterior cruciate ligament reconstruction: results from the Danish registry for knee ligament reconstructions

BACKGROUND

Revision anterior cruciate ligament (ACL) reconstruction is poorly described because of its rare incidence and mainly small case series presented in the literature. The Danish ACL reconstruction registry has monitored the development in revision ACL reconstruction since 2005.

HYPOTHESIS

We hypothesized that younger patients had a higher risk of revision ACL reconstruction than older patients and that subjective clinical outcome was worse after revision ACL reconstruction than after primary ACL reconstruction.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

All clinics performing ACL reconstructions in Denmark report to the national ACL reconstruction registry. The revision rate after primary ACL reconstruction (n = 12,193 procedures) and re-revision rate after revision ACL reconstruction (n = 1099 procedures) were calculated for the period of 2005 to 2010. Outcome at 1-year follow-up for the revision cohort was reported using the Knee Injury and Osteoarthritis Outcome Score (KOOS), Tegner function score, and objective knee stability measurement.

RESULTS

The rate of revision ACL reconstruction was 4.1% after 5 years. Revision occurred most frequently after 1 to 2 years. Patients below 20 years of age at the time of primary ACL reconstruction had a higher risk of revision (8.7%) than did patients older than 20 years of age (2.8%) (adjusted relative risk, 2.58; 95% confidence interval, 2.02-3.30). The KOOS scores 1 year after revision ACL reconstruction (mean ± standard deviation) were 73 ± 18 for symptoms, 78 ± 17 for pain, 84 ± 16 for activities of daily living, 52 ± 28 for sports, and 48 ± 21 for quality of life. All these scores were significantly lower than for primary ACL reconstruction: 77 ± 17 for symptoms, 84 ± 15 for pain, 89 ± 13 for activities of daily living, 62 ± 25 for sports, and 59 ± 21 for quality of life. Side-to-side difference in knee laxity improved from 5.8 mm before revision ACL reconstruction to 1.9 mm 1 year after revision ACL surgery. The use of allograft tissue for the revision procedure resulted in a higher risk of re-revision than did autograft tissue (relative risk, 2.05; 95% confidence interval, 1.5-2.4) (P < .01). The rate of re-revision after 5 years was 5.4%.

CONCLUSION

In this observational population-based study, the 5-year revision ACL reconstruction rate was 4.1%. Despite achieving acceptable knee stability after revision ACL reconstruction, subjective outcome is less favorable than after primary ACL reconstruction.

Association between previous meniscal surgery and the incidence of chondral lesions at revision anterior cruciate ligament reconstruction

BACKGROUND

Knees undergoing revision anterior cruciate ligament (ACL) reconstruction typically have more intra-articular injuries than do knees undergoing primary reconstruction.

HYPOTHESIS

Previous partial meniscectomy (PM) is associated with a higher rate of chondral lesions at revision ACL reconstruction, whereas previous meniscal repair (MR) is not associated with a higher rate of chondral lesions at revision ACL reconstruction, compared with knees undergoing revision ACL with no previous meniscal surgery.

STUDY DESIGN

Cohort study (Prevalence); Level of evidence, 2.

METHODS

Data from a multicenter cohort was reviewed to determine the history of prior meniscal surgery (PM/MR) and the presence of grade II/III/IV chondral lesions at revision ACL reconstruction. The association between previous meniscal surgery and the incidence of chondral lesions was examined. Patient age was included as a covariate to determine if surgery type contributes predictive information independent of patient age.

RESULTS

The cohort included 725 ACL revision surgeries. Chondrosis was associated with patient age (P < .0001) and previous meniscal surgery (P < .0001). After adjusting for patient age, knees with previous PM were more likely to have chondrosis than knees with previous MR (P = .003) or no previous meniscal surgery (P < .0001). There was no difference between knees without previous meniscal surgery and knees with previous MR (P = .7). Previous partial meniscectomy was associated with a higher rate of chondrosis in the same compartment compared with knees without previous meniscal surgery (P < .0001) and knees with previous MR (P ≤ .03).

CONCLUSION

The status of articular cartilage at the time of revision ACL reconstruction relates to previous meniscal surgery independent of the effect of patient age. Previous partial meniscectomy is associated with a higher incidence of articular cartilage lesions, whereas previous meniscal repair is not. Although this association may reflect underlying differences in the knee at the time of prior surgery, it does suggest that meniscal repair is preferable when possible at the time of ACL reconstruction.