Index Anterior Cruciate Ligament Reconstruction Research Articles

Location and Progression of Chondral Injuries at the Time of Revision Anterior Cruciate Ligament Surgery Varies by Sex

To quantify progression of chondral and meniscal injuries between primary and revision anterior cruciate ligament (ACL) surgery. Patients who underwent both index and revision ACL reconstruction between 2000 and 2020 at our institution were identified, and dates of injury and surgery, demographics, and clinical data were obtained from operative reports. Outerbridge grade was recorded in each compartment, along with presence and location of meniscal injury. The frequency of each injury between first and second cases was calculated. Differences in injury and progression were compared over time as well as between patient sex and age. The study included 189 patients (96 female, 93 male). Age at first surgery was 31.7 ± 13.2 years. Mean time to second injury was 3.3 ± 3.0 years. In total, 116 patients had a new or previous chondral injury (odds ratio, 1.6; 95% CI, 1.2-2.1). The medial femoral condyle (31%) and the patella (21%) accounted for the highest proportion of new injury to articular surfaces, whereas new injury to menisci was comparable between the medial (25%) and lateral (23%) meniscus. At the time of revision ACL reconstruction, females had a high prevalence of chondral injuries to the lateral compartment, whereas males had a high prevalence of chondral injury to the medial femoral condyle. The prevalence of new chondral injuries was comparable between sexes, with males having a slightly higher proportion. While time between surgeries, sex, and age had graphical evidence of moderating risk, the effects were small and imprecise. Revision ACL reconstruction carried a 1.6 increase in the odds for new or progressive chondral lesions in our cohort. At the time of revision, females had a relatively higher proportion of lateral-sided chondral injuries, whereas males had a relatively higher proportion of medial femoral condyle injuries. The greatest increase in the prevalence of new and progressive lesions was observed in the medial femoral condyle and trochlea. This progression appeared to be moderated by time between surgeries, patient sex, and age; however, the differences were small and imprecise. Level IV, therapeutic case series.

Effect of Concomitant Lateral Meniscal Management on ACL Reconstruction Revision Rate and Secondary Meniscal and Cartilaginous Injuries

Background: Simultaneous meniscal tears are often present with anterior cruciate ligament (ACL) injuries, and in the acute setting, the lateral meniscus (LM) is more commonly injured than the medial meniscus. Purpose: To investigate how a concomitant LM injury, repaired, resected, or left in situ during primary ACL reconstruction (ACLR), affects the ACL revision rate and cartilaginous and meniscal status at the time of revision within 2 years after the primary ACLR. Study Design: Cohort study; Level of evidence, 3. Methods: Data for 31,705 patients with primary ACLR, extracted from the Swedish National Knee Ligament Registry, were used. The odds of revision ACLR, and cartilaginous as well as meniscal injuries at the time of revision ACLR, were assessed between the unexposed comparison group (isolated ACLR) and the exposed groups of interest (ACLR + LM repair, ACLR + LM resection, ACLR + LM repair + LM resection, or ACLR + LM injury left in situ). Results: In total, 719 (2.5%) of the included 29,270 patients with 2 years follow-up data underwent revision ACLR within 2 years after the primary ACLR. No significant difference in revision rate was found between the groups. Patients with concomitant LM repair (OR, 3.56; 95% CI, 1.57-8.10; P = .0024) or LM resection (OR, 1.76; 95% CI, 1.18-2.62; P = .0055) had higher odds of concomitant meniscal injuries (medial or lateral) at the time of revision ACLR than patients undergoing isolated primary ACLR. Additionally, higher odds of concomitant cartilage injuries at the time of revision ACLR were found in patients with LM resection at index ACLR compared with patients undergoing isolated primary ACLR (OR, 1.73; 95% CI, 1.14-2.63; P = .010). Conclusion: The results of this study demonstrated higher odds of meniscal and cartilaginous injuries at the time of revision ACLR within 2 years after primary ACLR + LM resection and higher odds of meniscal injury at the time of revision ACLR within 2 years after primary ACLR + LM repair compared with isolated ACLR. Surgeons should be aware of the possibility of concomitant cartilaginous and meniscal injuries at the time of revision ACLR after index ACLR with concomitant LM injury, regardless of the index treatment type received.

Poster 317: Preoperative and Operative Characteristics in the Context of Patient-Reported Outcomes for ACLR in Patients Aged 40 or Older: Allograft versus Autograft

Poster 317: Preoperative and Operative Characteristics in the Context of Patient-Reported Outcomes for ACLR in Patients Aged 40 or Older: Allograft versus Autograft

Paper 31: Quantitative MRI of the Hamstring Muscles Ten Years After Autograft Hamstring ACLR

Paper 31: Quantitative MRI of the Hamstring Muscles Ten Years After Autograft Hamstring ACLR

Paper 29: Untreated Type 4 Ramp Injuries at Index Anterior Cruciate Ligament Reconstruction Surgery Result in Higher Rates of Revision ACL-R within the First 2 Years

Objectives: Ramp lesions are commonly associated with ACL tears and recent studies have identified these lesions in 17-42% of patients undergoing treatment with ACL reconstruction. In addition to its association with ACL tears, there is increasing recognition that ramp lesions lead to significant biomechanical changes in the knee. Our study seeks to investigate whether patients with type 4 ramp lesions at the time of initial ACL reconstruction have higher rates of reoperation, specifically revision ACL-R, compared to those that undergo ACL-R without a ramp lesion. Methods: Retrospective chart review was conducted on all patients surgically treated with ACL reconstruction at level I academic center from January 2015 to December 2019. Type 4 ramp lesions were diagnosed on preoperative MRIs by two MSK-trained radiologists blinded to clinical information. Demographic, associated injuries, intra-operative, clinical data, and re-operations were extracted from our ACL-R database. Statistical analysis using Students T-test and chi x2 for comparing cohorts. Cox Regression with covariates for re-operation surgery was used. Risk factors evaluated for revision surgery included patient age, sex, BMI, treatment of ramp, timing to surgery. Inter-reliability coefficient correlation was used for MRI reliability. Results: A total of 255 patients ACL-R were identified that met inclusion. There were 170 patients with ACL-R without a ramp present and 85 patients with ACL-R + type 4 ramp lesion. Revision ACL-R occurred in 10.5% in ramp group compared to 2.4% without ramp (P<0.005). Around 75% of the revision ACL-R for the ramp group occurred within the first 2 and half years after surgery. Risk factor associated with revision ACL-R included untreated ramp (HR 10.46 (CI: 2.13-109.70) p=0.01). Conclusions: Meniscal ramp lesions with ACL-R result in higher revision ACL-R when compared to no ramp ACL-R. Most significantly untreated type 4 ramp lesions with concomitant ACL-R were associated with increased risk of ACL-R revision surgery . Standard portals are not sufficient in diagnosing and assessing stability of ramp lesions intra-operatively. [Table: see text]

Poster 305: Hybrid Transtibial Technique for Femoral Tunnel Drilling in Anterior Cruciate Ligament Reconstruction: A Retrospective, Matched Comparison Study to Anteromedial Portal and Transtibial Approaches

Objectives: Improved biomechanical and clinical outcomes have been reported when femoral anterior cruciate ligament (ACL) tunnels are centered on the native footprint. The anteromedial portal (AMP) technique achieves improved aperture position when compared to a transtibial (TT) approach but sacrifices technical ease and creates a shorter more angulated tunnel. A hybrid transtibial technique (HTT) using medial portal guidance of a flexible transtibial guide wire may combine the strengths of both the AM and TT approaches while mitigating the technical challenges of both techniques. The purpose of our study was to evaluate the clinical efficacy of ACLR using a HTT technique for femoral tunnel drilling in comparison to matched cohorts of AMP and TT drilling approaches in terms of failure/revision requirements and patient-reported outcomes. Methods: A database consisting of all patients with isolated ACL tear and primary reconstruction at a single center between 2005 and 2020 was retrospectively reviewed. Inclusion criteria were patients age ³ 13 years at the time of index ACL reconstruction (ACLR), isolated ACL tear with/without concomitant meniscal/chondral pathology and had minimum 2 year ³ postoperative follow-up. Patients with open physes, prior surgical intervention on the ipsilateral knee, chondral pathology treated with high tibial osteotomy/distal femoral osteotomy, treated for other concurrent ligamentous pathology were excluded. Patients treated with the AMP, TT, and HTT approach meeting inclusion criteria were matched based on age ± 3 years, same sex, and body mass index (BMI) ± 3 Kg/m2. Demographical data (Table 1), surgical data, plain radiographic femoral tunnel angle measurements on anteroposterior and lateral films, postoperative complications and reoperation/revision rates, and patient reported outcome (PRO) scores were collected and reported for each of the three cohorts. Results: A total of 495 patients were included; 170 patients underwent ACLR using the HTT approach, 162 using AMP approach, and 163 using the TT approach. The most common graft of choice for HTT technique was bone patellar tendon bone (BPTB) (162/170 [95.3%]) and for AMP (131/162 [80.9%] and TT (158/163 [96.9%]) technique was hamstring (Table 2). The median (IQR) femoral tunnel angle on sagittal plane showed significant differences between HTT 40° (34°, 46°) and TT 32° (27°, 38°) cohorts ( P- value < 0.0001) (Table 3). On coronal plane the median (IQR) femoral tunnel angles showed significant differences between HTT 47° (42°, 52°) and for both AMP 44° (33°, 54°) and TT 55° (47°, 60°) cohorts ( P- value: 0.001 and <0.001 respectively. Recurrent ACL injury in the ipsilateral knee was experienced in 3/170 (1.8%) HTT patients, 6/162 (3.7%) AMP patients, and 6/163 (3.7%) TT patients at minimum 2-year clinical follow-up (Table 4). When patients were surveyed via phone or email questionnaires, 6/170 (7.4%) HTT, 11/163 AMP (20%), and 18/162 (24.3%) TT patients responded to having further ACLR procedures. The Knee injury and Osteoarthritis Outcome Score (KOOS) pain score and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) function and total scores were found to be statistically significant between HTT and TT technique patients. All other PRO scores showed comparable scores between HTT patients when compared with AMP and TT patients. Conclusions: Patients that underwent ACLR with HTT approach had lower failure/revision rates and comparable or better PRO scores at medium-term follow-up when compared to AMP and TT approach. [Table: see text][Table: see text][Table: see text][Table: see text]

Effect of Quadriceps and Hamstring Strength Relative to Body Weight on Risk of a Second ACL Injury: A Cohort Study of 835 Patients Who Returned to Sport After ACL Reconstruction.

Anterior cruciate ligament (ACL) injuries are common sports-related injuries with a high risk of reinjury after return to sport (RTS). Rehabilitation aims to regain symmetrical knee strength and function to minimize the risk of a second ACL injury after RTS. To determine the effect of absolute quadriceps and hamstring strength, normalized by body weight, on the risk of a second ACL injury during the first 2 years after RTS in patients who have undergone ACL reconstruction (ACLR). Cohort study; Level of evidence, 3. Data from patients after index ACLR at the time of RTS were extracted from a rehabilitation registry-Project ACL. Patients who had performed isokinetic tests for quadriceps and hamstring strength and hop tests before RTS were included. The endpoint was a second ACL injury or a follow-up of 2 years after RTS after ACLR. A total of 835 patients (46% women), with a mean age of 23.9 ± 7.7 years, were included. During the study period, 69 (8.3%) second ACL injuries (ipsilateral and contralateral) occurred. Greater relative quadriceps strength in the injured leg increased the risk of a second ACL injury (relative risk [RR], 1.69 [95% CI, 1.05-2.74]; P = .032). In patients who had recovered symmetrical quadriceps strength (limb symmetry index ≥90%), there was no effect of quadriceps strength on the risk of second ACL injury (RR, 1.33 [95% CI, 0.69-2.56]; P = .39). Quadriceps strength on the healthy side or hamstring strength, regardless of side, had no effect on the risk of a second ACL injury. Greater relative quadriceps strength in the injured leg at the time of RTS after ACLR was associated with an increased risk of a second ACL injury. There was no effect of relative quadriceps strength on the risk of a second ACL injury in patients who had recovered symmetrical quadriceps strength.

Different patient and activity-related characteristics result in different injury profiles for patients with anterior cruciate ligament and posterior cruciate ligament injuries

PurposeTo compare patient characteristics including patient sex, age, body mass index (BMI), activities at the time of injury and injury profiles in patients with anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) injuries.MethodsData were obtained from the Swedish National Knee Ligament Registry. Two study groups were created: (1) index ACL reconstruction (ACL group) and (2) index PCL reconstruction (PCL group). Between-group differences were investigated using Fisher’s exact test and Fisher’s non-parametric permutation test for dichotomous variables and continuous variables, respectively.ResultsOf 39,010 patients, 38,904 were ACL injuries. A larger proportion of patients with combined injuries to the PCL, meniscus and cartilage were female, aged > 25 years and with a BMI of > 35 kg/m2 compared with patients with combined injuries to the ACL, meniscus and cartilage. An isolated ACL injury was more commonly found in males, while all other injury profiles of ACL, including combined injuries with meniscus, cartilage and collateral ligament injuries, were more frequently observed in females. The PCL injuries were sustained either during pivoting sports, non-pivoting sports or were traffic-related.ConclusionDifferent patient characteristics (BMI, age and sex), and activities at the time of injury (sport- versus traffic-related activities), resulted in distinct injury profiles for the ACL and PCL groups. These findings provide valuable information of the way specific injury patterns of cruciate ligament injuries occur, and subsequently may help clinicians with the diagnostic process of ACL and PCL injuries.Level of evidenceIII.

Poster 253: Anterior Cruciate Ligament Reconstruction in 118 Competitive Wrestlers: Outcomes, Reoperations, and Return to Play at 5 years Mean Follow Up

Objectives:Introduction:Wrestling is a physically demanding sport with young athletes prone to anterior cruciate ligament (ACL) injuries. However, there is a paucity of data evaluating the results of ACL reconstruction (ACLR) in this cohort.Purpose:To assess patient-reported outcomes, reoperation rates, graft survival, and return to play (RTP) following ACLR in a large cohort of competitive wrestlersMethods:All competitive wrestlers (high school, collegiate, or professional) with a history of an ACLR at a single institution between 2000 and 2019 were retrospectively identified. Graft failure was defined as a re-tear determined by clinical or advanced imaging evaluation, and/or revision ACL reconstruction. All patients were contacted for determination of reinjury rates, current sport status, visual analog scale (VAS), International Knee Documentation Committee (IKDC) and Tegner activity scores.Results:118 knees in 114 wrestlers were included at a median follow-up time of 5.8 years (IQR: 3.6 – 10.3). The median age was 17 years (15 – 18) with 116 (98%) males. ACLR was most often performed with bone-patellar tendon-bone (BTB) autograft (n = 64; 54%) or hamstring tendon (HT) autograft (n = 43; 36%). At final follow-up, 80% of athletes were able to RTP at a median of 273 days (IQR: 203 – 379). Graft failure occurred in 17 (14%) patients at a median time of 1.4 years (IQR: 0.8 – 4.7) after the index ACLR. BTB autograft demonstrated a lower failure rate compared to HT autograft (8% vs. 21%; P = 0.044). Kaplan-Meier survivorship free from graft failure for the entire cohort was 95.3% at 1 year, 92.5% at 2 years, 89.8% at 5 years, 84.6 at 10 years, 77.6 at 20 years. BTB autograft was associated with better survival than HT autograft up to 15 years after the index ACLR (90.4% vs. 76.3%; P = 0.030).Conclusions:Return to competitive wrestling was observed in 80% of athletes after ACLR, with 14% of wrestlers experiencing graft failure. BTB autograft reconstruction may serve as a more durable graft for competitive wrestlers with lower rates of failure when compared to HT autograft even up to 15 years after surgery.Table 1.Baseline Demographic, Clinical, and Operative DataFigure 1.Kaplan-Meier survivorship curve demonstrating progression to graft failure of the entire cohort.Figure 2.Kaplan-Meier curve demonstrating progression to graft failure of each graft type.Figure 3.Kaplan-Meier curve demonstrating progression to graft failure of BTB autograft vs. hamstring autograft

Anterior Cruciate Ligament Reconstruction in 107 Competitive Wrestlers: Outcomes, Reoperations, and Return to Play at 6-Year Follow-up.

Background:Wrestling is a physically demanding sport, with young athletes prone to anterior cruciate ligament (ACL) injuries. There is a paucity of data evaluating the results of ACL reconstruction (ACLR) in this cohort.Purpose:To assess return to sport (RTS), patient-reported outcomes, reoperation rates, and graft survival after ACLR in a large cohort of competitive wrestlers at midterm follow-up.Study Design:Case series; Level of evidence, 4.Methods:We identified all competitive wrestlers (club, high school, collegiate, or professional) with a history of an ACLR at a single institution between 2000 and 2019. Graft failure was defined as a retear (as determined via clinical or advanced imaging evaluation) and/or revision ACLR. All patients were contacted for determination of reinjury rates; current sport status; and pain visual analog scale, International Knee Documentation Committee, and Tegner activity scores.Results:Included were 107 knees in 103 wrestlers, with a median follow-up time of 5.9 years (interquartile range [IQR], 3.9-10.3 years). The median age was 17 years (IQR, 15-18 years), with 106 (99%) male patients, and the distribution of bone–patellar tendon–bone (BTB) and hamstring tendon (HT) autografts was 64 (60%) and 43 (40%), respectively. At final follow-up, 80% of athletes were able to RTP at a median of 280 days (IQR, 212-381 days). Graft failure occurred in 14 (13%) knees at a median time of 1.8 years (IQR, 0.7-5.3 years) after the index ACLR. BTB autograft demonstrated a lower failure rate compared with HT autograft (8% vs 21%; P = .044) and was associated with better survival compared with HT autograft up to 15 years after the index ACLR (90.4% vs 76.3%; P = .030). When compared by graft diameter, HT autografts of at least 7.5 mm were not associated with a lower graft failure than BTB constructs of all sizes (P = .205).Conclusion:Return to competitive wrestling was observed in 80% of athletes after ACLR, with 14% of wrestlers experiencing graft failure. BTB autograft was associated with better survival than HT autograft.

Meniscal Treatment as a Predictor of Worse Articular Cartilage Damage on MRI at 2 Years After ACL Reconstruction: The MOON Nested Cohort

Background: Patients undergoing anterior cruciate ligament reconstruction (ACLR) are at an increased risk for posttraumatic osteoarthritis (PTOA). While we have previously shown that meniscal treatment with ACLR predicts more radiographic PTOA at 2 to 3 years postoperatively, there are a limited number of similar studies that have assessed cartilage directly with magnetic resonance imaging (MRI). Hypothesis: Meniscal repair or partial meniscectomy at the time of ACLR independently predicts more articular cartilage damage on 2- to 3-year postoperative MRI compared with a healthy meniscus or a stable untreated tear. Study Design: Cohort study; Level of evidence, 2. Methods: A consecutive series of patients undergoing ACLR from 1 site within the prospective, nested Multicenter Orthopaedic Outcomes Network (MOON) cohort underwent bilateral knee MRI at 2 to 3 years postoperatively. Patients were aged <36 years without previous knee injuries, were injured while playing sports, and had no history of concomitant ligament surgery or contralateral knee surgery. MRI scans were graded by a board-certified musculoskeletal radiologist using the modified MRI Osteoarthritis Knee Score (MOAKS). A proportional odds logistic regression model was built to predict a MOAKS-based cartilage damage score (CDS) relative to the contralateral control knee for each compartment as well as for the whole knee, pooled by meniscal treatment, while controlling for sex, age, body mass index, baseline Marx activity score, and baseline operative cartilage grade. For analysis, meniscal injuries surgically treated with partial meniscectomy or meniscal repair were grouped together. Results: The cohort included 60 patients (32 female; median age, 18.7 years). Concomitant meniscal treatment at the time of index ACLR was performed in 17 medial menisci (13 meniscal repair and 4 partial meniscectomy) and 27 lateral menisci (3 meniscal repair and 24 partial meniscectomy). Articular cartilage damage was worse in the ipsilateral reconstructed knee (P < .001). A meniscal injury requiring surgical treatment with ACLR predicted a worse CDS for medial meniscal treatment (medial compartment CDS: P = .005; whole joint CDS: P < .001) and lateral meniscal treatment (lateral compartment CDS: P = .038; whole joint CDS: P = .863). Other predictors of a worse relative CDS included age for the medial compartment (P < .001), surgically observed articular cartilage damage for the patellofemoral compartment (P = .048), and body mass index (P = .007) and age (P = .020) for the whole joint. Conclusion: A meniscal injury requiring surgical treatment with partial meniscectomy or meniscal repair at the time of ACLR predicted worse articular cartilage damage on MRI at 2 to 3 years after surgery. Further research is required to differentiate between the effects of partial meniscectomy and meniscal repair.

RISK FACTORS FOR FAILURE FOLLOWING ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION IN A PEDIATRIC POPULATION: A NOVEL PREDICTION ALGORITHM

Background:Pediatric anterior cruciate ligament (ACL) reconstruction is becoming increasingly common, however, there is limited literature on the risk factors for failure in this demographic.Hypothesis/Purpose:In the present study we sought to: 1. To determine the rate of pediatric ACL reconstruction (ACLR) failure requiring revision surgery in a nationally representative sample. 2. To determine the associated patient/injury-specific risk factors for ACLR failure. 3. To examine the differences in the rate and risks of failure between pediatric and adult patients.Methods:Patient records were drawn from Humana individual health plans and Medicare medical records. Adult and pediatric patients who underwent primary ACLR and subsequent reoperation for either ACL revision surgery or a revision meniscal procedure between 2011-2016 were identified. Multivariate regression was used to determine the significant risk factors for ACL revision and overall reoperation rates in pediatric and adult patients. A risk algorithm was developed to predict the risk of ACL revision following pediatric ACL reconstruction.Results:Pediatric patients were significantly more likely to require ACL revision within one year (OR=1.97, 95%CI 1.57-2.45, p<0.0001) and five years (OR=3.22, 95%CI 2.77-3.72, p<0.0001) following their index ACLR compared to adults. Survivorship of the index ACL procedure was significantly decreased in pediatric patients (log-rank test p<0.0001) (Figure 1). Pediatric patients were also at higher risk of sustaining a contralateral ACL tear compared to adults (5.9% vs. 1.4%, respectively, p<0.0001). Meniscus injury was a risk factor for overall re-operation (OR=2.18, 95%CI 1.67-2.89 p<0.0001) as well as ACL revision (OR=2.28, 95%CI=1.66-3.21, p<0.0001) in the pediatric cohort. This increased risk was sustained despite the type of meniscal tear intervention, with patients undergoing concurrent meniscal repair (OR=1.84, 95%CI 1.43-2.38, p<0.0001) or meniscectomy (OR=2.20, 95%CI 1.72-2.82, p<0.0001) having a higher likelihood of requiring a revision ACLR. Concomitant MCL injury but not LCL injury was a risk factor for ACL revision in this cohort (OR=1.70, 95%CI 1.31-2.19, p<0.0001). Male sex and (OR=0.78, 95%CI 0.63-0.96, p=0.0204) and being >14 years old (OR=0.62, 95%CI 0.45-0.86, p=0.0035) was associated with a decreased risk of overall reoperation. The risk algorithm demonstrated the highest probability for ACLR failure in females, less than 15 years of age, with concomitant meniscus and MCL injury, demonstrating a 36% risk of failure (Table 1).Conclusion:Compared to adults, pediatric patients have an increased likelihood of ACL revision surgery, contralateral ACL tears, and meniscal reoperation within 5 years of an index ACLR.Figure 1.

Risk Factors for Failure After Anterior Cruciate Ligament Reconstruction in a Pediatric Population: A Prediction Algorithm.

Background:Anterior cruciate ligament reconstruction (ACLR) in pediatric patients is becoming increasingly common. There is growing yet limited literature on the risk factors for revision in this demographic.Purpose:To (1) determine the rate of pediatric revision ACLR in a nationally representative sample, (2) ascertain the associated patient- and injury-specific risk factors for revision ACLR, and (3) examine the differences in the rate and risks of revision ACLR between pediatric and adult patients.Study Design:Case-control study; Level of evidence, 3.Methods:The PearlDiver patient record database was used to identify adult patients (age ≥20 years) and pediatric patients (age <20 years) who underwent primary ACLR between 2010 and 2015. At 5 years postoperatively, the risk of revision ACLR was compared between the adult and pediatric groups. ACLR to the contralateral side was also compared. Multivariate logistic regression was used to determine the significant risk factors for revision ACLR and the overall reoperation rates in pediatric and adult patients; from these risk factors, an algorithm was developed to predict the risk of revision ACLR in pediatric patients.Results:Included were 2055 pediatric patients, 1778 adult patients aged 20 to 29 years, and 1646 adult patients aged 30 to 39 years who underwent ACLR. At 5 years postoperatively, pediatric patients faced a higher risk of revision surgery when compared with adults (18.0 % vs 9.2% [adults 20-29 years] and 7.1% [adults 30-39 years]; P < .0001), with significantly decreased survivorship of the index ACLR (P < .0001; log-rank test). Pediatric patients were also at higher risk of undergoing contralateral ACLR as compared with adults (5.8% vs 1.6% [adults 20-29 years] and 1.9% [adults 30-39 years]; P < .0001). Among the pediatric cohort, boys (odds ratio [OR], 0.78; 95% CI, 0.63-0.96; P = .0204) and patients >14 years old (OR, 0.62; 95% CI, 0.45-0.86; P = .0035) had a decreased risk of overall reoperation; patients undergoing concurrent meniscal repair (OR, 1.84; 95% CI, 1.43-2.38; P < .0001) or meniscectomy (OR, 2.20; 95% CI, 1.72-2.82; P < .0001) had an increased risk of revision surgery. According to the risk algorithm, the highest probability for revision ACLR was in girls <15 years old with concomitant meniscal and medial collateral ligament injury (36% risk of revision).Conclusion:As compared with adults, pediatric patients had an increased likelihood of revision ACLR, contralateral ACLR, and meniscal reoperation within 5 years of an index ACLR. Families of pediatric patients—especially female patients, younger patients, and those with concomitant medial collateral ligament and meniscal injuries—should be counseled on such risks.

Risk Factors for New Meniscal Tears following Anterior Cruciate Ligament Reconstruction.

This study aims to compare the rate of meniscal tears after anterior cruciate ligament (ACL) reconstruction in patients who have undergone concomitant meniscal repair during the index procedure with that in patients who have not undergone such surgery. It also evaluates other risk factors, such as age, gender, race, body mass index (BMI), site of concomitant meniscal surgery, and ACL graft failure. This is a retrospective study conducted at a large tertiary public hospital. Patients who underwent primary anterior cruciate ligament reconstruction (ACLR) surgery with or without concomitant meniscal repair from 2011 to 2016 were identified. Patients with old meniscal tears and previous meniscal surgeries were excluded. The aforementioned demographical, injury, and surgical details were obtained and analyzed using univariate and multivariate logistic regression analysis. Our study cohort included 754 patients. Primary ACLR surgery was performed with meniscal repair in 172 (22.8%) of the patients, with meniscectomy in 202 (26.8%) of the patients, and without concomitant meniscal surgery in 380 (50.4%) of the patients. A total of 81 (10.7%) patients developed meniscal tears after the index procedure. Such tears occurred in 12.2% (21 of 172) of the patients who had undergone concomitant meniscal repair during the index ACLR, and in 10.3% (60 of 582) of the patients who had not undergone concomitant meniscal repair (p = 0.30). On multivariate analysis, only ACL graft failure was significantly associated with new meniscal tears (p < 0.001, odds ratio 18.69, 95% confidence interval 9.18-38.05). ACL graft failure is the only independent risk factor for meniscal tears after ACLR surgery in our large cohort of patients. Concomitant meniscal repair was not an associated risk factor.

Beighton Score, Tibial Slope, Tibial Subluxation, Quadriceps Circumference Difference, and Family History Are Risk Factors for Anterior Cruciate Ligament Graft Failure: A Retrospective Comparison of Primary and Revision Anterior Cruciate Ligament Reconstructions

To assess patient history, physical examination findings, magnetic resonance imaging (MRI) and 3-dimensional computed tomographic (3D CT) measurements of those with anterior cruciate ligament (ACL) graft failure compared with primary ACL tear patients to better discern risk factors for ACL graft failure. We performed a retrospective review comparing patients who underwent revision ACL reconstruction (ACLR) with a primary ACLR group with minimum 1-year follow-up. Preoperative history, examination, and imaging data were collected and compared. Measurements were made on MRI, plain radiographs, and 3D CT. Inclusion criteria were patients who underwent primary ACLR by a single surgeon at a single center with minimum 1-year follow-up or ACL graft failure with revision ACLR performed by the same surgeon. A total of 109 primary ACLR patients, mean age 33.7 years (range 15 to 71), enrolled between July 2016 and July 2018 and 90 revision ACLR patients, mean age 32.9 years (range 16 to 65), were included. The revision ACLR group had increased Beighton score (4 versus 0; P < .001) and greater side-to-side differences in quadricep circumference (2 versus 0 cm; P < .001) compared with the primary ACLR group. A family history of ACL tear was significantly more likely in the revision group (47.8% versus 16.5%; P < .001). The revision group exhibited significantly increased lateral posterior tibial slope (7.9° versus 6.2°), anterolateral tibial subluxation (7.1 versus 4.9 mm), and anteromedial tibia subluxation (2.7 versus 0.5 mm; all P < .005). In the revision group, femoral tunnel malposition occurred in 66.7% in the deep-shallow position and 33.3% in the high-low position. The rate of tibial tunnel malposition was 9.7% from medial to lateral and 54.2% from anterior to posterior. Fifty-six patients (77.8%) had tunnel malposition in ≥2 positions. Allograft tissue was used for the index ACLR in 28% in the revision group compared with 14.7% in the primary group. Beighton score, quadriceps circumference side-to-side difference, family history of ACL tear, lateral posterior tibial slope, anterolateral tibial subluxation, and anteromedial tibia subluxation were all significantly different between primary and revision ACLR groups. In addition, there was a high rate of tunnel malposition in the revision ACLR group.

High incidence of subsequent re-operation following treatments for medial meniscus tears combined with anterior cruciate ligament reconstruction: second-look arthroscopic study

BackgroundThe Multicenter Orthopaedic Outcomes Network (MOON) group recently reported that medial meniscus (MM) repairs are associated with more frequent re-operations when compared to lateral meniscus (LM) repairs. The purpose of this study was to compare the meniscal healing and the incidence of subsequent re-operation of medial and lateral meniscal tears that occurred concurrently with anterior cruciate ligament (ACL) injuries.MethodsWe retrospectively reviewed patients who underwent second-look arthroscopy after primary ACL reconstruction (ACLR) between June 2005 to December 2016. The healing of meniscal tears following repair or left in situ, and re-tear following partial meniscectomy, were evaluated via second-look arthroscopy and compared between medial and lateral meniscus. Moreover, the incidence of subsequent meniscal re-operation after the index ACLR were investigated and compared between medial and lateral meniscus. Subsequent meniscal re-operation was performed in cases of the following three symptomatic meniscus tears: re-tears at the meniscectomy site; new tears; and failed healing of repaired or left in situ meniscus.ResultsThere were 148 meniscal tears in 121 patients at index ACLR. There were 62 MM tears, 38 LM tears, and 24 bilateral meniscus tears. At second-look arthroscopy, the “successful healing” rate for tears following repair was higher in LM tears (91.2%) compared to MM tears (80.0%), although it was not statistically significant (p > 0.05). No significant differences were observed in the healing of left in situ tears or re-tear of meniscectomy site between medial and lateral meniscus. Patients with MM tears combined with ACL injuries had a higher incidence of subsequent meniscal re-operation compared to patients with LM tears (25.6% vs 16.1%, p = 0.025).ConclusionsThere was a trend for the successful healing rate to be higher in LM repairs than MM repairs. Subsequent meniscal re-operations after ACLR were more frequent in patients with medial meniscal tears concurrently with ACL injuries in comparison to patients with lateral meniscal tears.Level of studyLevel IV, retrospective case series.

Length of Time Between Anterior Cruciate Ligament Reconstruction and Return to Sport Does Not Predict Need for Revision Surgery in National Football League Players

To determine whether the length of time between primary anterior cruciate ligament reconstruction (ACLR) and return to sport (RTS) predicted the need for revision ACLR in National Football League (NFL) athletes. All NFL players who underwent ACLR from 2009 to 2015 were identified. The date of index ACLR and date of return to NFL regular-season game play after surgery were recorded. The length of time between ACLR and RTS was compared between players who required revision ACLR and those who did not. Correlation coefficients were used to assess whether players who RTS sooner sustained recurrent anterior cruciate ligament injury at an earlier date. A total of 130 NFL players (average age, 25.3 ± 3.2years) who underwent ACLR and returned to sport were identified. The average time to RTS after ACLR was 49.7weeks after surgery. Of the players, 23 (18%) required revision ACLR. There was no significant difference in the length of time between ACLR and RTS in players who did not require revision ACLR (50.2 ± 10.1weeks) and those who did (48.3 ± 11.0weeks, P= .40). Time to RTS was not found to correlate with time to reinjury in athletes requiring revision ACLR (R= 0.21; 95% confidence interval, -0.18 to 0.54). A large proportion of players (56%) sustained a reinjury within the first 10weeks of returning to NFL game play. Our study found that timing of RTS after ACLR was not a significant risk factor for revision surgery in NFL athletes. Time to RTS was also not shown to correlate with time to reinjury. Level III, case-control study.

Pediatric ACL Reconstruction and Return to the Operating Room: Revision Is Less Than Half of the Story.

Although there are several causes of unplanned return to the operating room (RTOR) following pediatric anterior cruciate ligament (ACL) reconstruction (ACLR), prior outcomes studies focus primarily on the risk of graft failure. We sought to comprehensively describe indications for RTOR in pediatric primary ACLR patients, estimate associated rates of RTOR, and assess the impact of concomitant meniscal procedures on these rates. This retrospective cohort study considered patients who underwent primary ACLR at an urban, pediatric tertiary care hospital between 2013 and 2015. Cohorts were defined based on the presence or absence of a concomitant surgical meniscal procedure with the index ACLR. The primary outcome was RTOR for an indication pertaining to ACLR or a potential predilection for knee injury. Cases of RTOR were cataloged and classified according to indication. Survival analyses were performed using the Kaplan-Meier estimation and competing-risks regression. Comparisons of any-cause RTOR rates were done using log-rank tests. After exclusion criteria were applied, 419 subjects were analyzed. RTOR indications were organized into 5 categories. The overall rate for any RTOR by 3 years after surgery was 16.5%. Graft failure and contralateral ACL tear were the most common indications for RTOR, with predicted rates of 10.3% and 7.1%, respectively. ACL graft failure accounted for less than half of RTOR cases cataloged. Patients who had a concomitant meniscus procedure had lower rates of RTOR. Approximately 1 in 6 pediatric ACLR patients underwent ≥1 repeat surgery within 3 postoperative years for indications ranging from wound breakdown to contralateral ACL rupture. While previous studies revealed high rates of complication after pediatric ACLR due primarily to graft failure, we found that re-tear is responsible for less than half of the 3-year RTOR risk. As almost half of re-tears in our sample occurred before clearance to return to full activities, we suspect that the high rate of complication is largely attributable to pediatric patients' high activity levels and difficulties adhering to postoperative restrictions. Early treatment of meniscus pathology may reduce rates of RTOR. Level III-therapeutic.

Intermediate- to Long-Term Results of Combined Anterior Cruciate Ligament Reconstruction and Autologous Chondrocyte Implantation.

Background:Cartilage injury associated with anterior cruciate ligament (ACL) ruptures is common; however, relatively few reports exist on concurrent cartilage repair with ACL reconstruction. Autologous chondrocyte implantation (ACI) has been utilized successfully for treatment of moderate to large chondral defects.Hypothesis:ACL insufficiency with relatively large chondral defects may be effectively managed with concurrent ACL reconstruction and ACI.Study Design:Case series; Level of evidence, 4.Methods:Patients undergoing concurrent ACL primary or revision reconstruction with ACI of single or multiple cartilage defects were prospectively evaluated for a minimum 2 years. Pre- and postoperative outcome measures included the modified Cincinnati Rating Scale (MCRS), Western Ontario and McMaster Universities Osteoarthritis Index, visual analog pain scales, and postsurgery satisfaction surveys. ACI graft failure or persistent pain without functional improvement were considered treatment failures.Results:Twenty-six patients were included, with 13 primary and 13 revision ACL reconstructions performed. Mean defect total surface area was 8.4 cm2, with a mean follow-up of 95 months (range, 24-240 months). MCRS improved from 3.62 ± 1.42 to 5.54 ± 2.32, Western Ontario and McMaster Universities Osteoarthritis Index from 45.31 ± 17.27 to 26.54 ± 17.71, and visual analog pain scale from 6.19 ± 1.27 to 3.65 ± 1.77 (all Ps <.001). Eight patients were clinical failures, 69% of patients were improved at final follow-up, and 92% stated they would likely undergo the procedure again. No outcome correlation was found with regard to age, body mass index, sex, defect size/number, follow-up time, or primary versus revision ACL reconstruction. In subanalysis, revision ACL reconstructions had worse preoperative MCRS scores and greater defect surface areas. However, revision MCRS score improvements were greater, resulting in similar final functional scores when compared with primary reconstructions.Conclusion:Challenging cases of ACL tears with large chondral defects treated with concurrent ACL reconstruction and ACI can lead to moderately improved pain and function at long-term follow-up. Factors associated with clinical failure are not clear. When combined with ACI, patients undergoing revision ACL reconstructions have worse function preoperatively compared with those undergoing primary reconstructions but have similar final outcomes.

Two-Stage Revision Anterior Cruciate Ligament Reconstruction.

The number of primary anterior cruciate ligament (ACL) tears is rapidly increasing. In patients who wish to return to their preoperative level of function, specifically as it pertains to participation in sports, the gold standard of treatment following an ACL tear remains an anterior cruciate ligament (ACL) reconstruction. Despite a majority of good/excellent results following primary ACL reconstruction, there is a growing subset of patients with persistent or recurrent functional instability who require revision ACL reconstruction. Preoperative planning for revision ACL reconstruction requires a careful understanding of the root cause of ACL failure, including possible technical causes of primary ACL failure and the presence of combined knee pathology that was not addressed at the index ACL reconstruction. The decision to perform 2-stage revision ACL reconstruction is multifactorial and is reached by technical considerations that may make a 1-stage revision less optimal, including tunnel widening, arthrofibrosis, active infection, and others. Concomitant knee pathology such as meniscal deficiency, malalignment (including an increase in posterior tibial slope), chondral lesions, and other ligamentous laxity may also require a staged approach to treatment. This evidence-based review covers the indications for 2-stage revision ACL reconstruction, surgical techniques, evidence for and technique of bone grafting prior ACL tunnels, and outcomes of 2-stage revision stratified by initial cause of ACL reconstruction failure. With proper preoperative planning and an understanding of the cause of failure following the primary ACL reconstruction, revision ACL reconstruction can offer excellent outcomes in the motivated patient. [Orthopedics. 2016; 39(3):e456-e464.].