Meniscal integrity predicts laxity of anterior cruciate ligament reconstruction

Does concomitant meniscus repair and meniscectomy show different efficacy in anterior cruciate ligament reconstruction? A systematic review and meta-analysis

Aims

Currently, it is advised to perform meniscal repair instead of meniscectomy in certain cases of primary anterior cruciate ligament reconstruction (ACLR). However, the level of evidence is low. Therefore, this study aimed to compare the effectiveness of meniscectomy and meniscus repair in addition to ACLR.

Methods

The systematic search was conducted in three online databases (EMBASE, MEDLINE, and Cochrane) from inception until October 2021 for the literature on primary ACLR and concomitant meniscal surgery. Eligible studies compared the following outcomes between meniscal repair and meniscectomy groups: the Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm score, International Knee Documentation Committee (IKDC) score, and KT-arthrometer examinations. Lastly, we calculated pooled mean differences (MDs) with 95 % confidence intervals (CIs) from the change between pre- and post-intervention values.

Results

Of 10,565 studies, 22 met the inclusion criteria, with a follow-up between 6 and 43 months. We found no difference when comparing the KOOS subscale changes-only in the KOOS pain subscale (MD = -1.6; CI: -2.48, -0.72). However, these results were not clinically significant. We analyzed the lateral and media meniscal injuries separately and concluded the same results regarding KOOS changes. We found no significant differences in the Lysholm score change (MD = -2.61; CI: -5.51, 0.29), changes in IKDC score (MD = 1.08; CI: -4.05, 6.21) or the change for the KT-arthrometer side-to-side difference (MD = -0.50; CI: -1.06, 0.06).

Conclusion

Based on our result, we did not find a clinically significant difference between meniscus repair and meniscectomy during primary ACLR regarding patient-reported outcomes in a short-term follow-up.

Translational potential

Our research supports the prompt integration of findings into clinical practice for treating meniscus injuries during ACL reconstruction. We recommend considering both meniscus repair and meniscectomy, as the available data indicate their effectiveness. Further studies are necessary to assess the long-term impacts, particularly on osteoarthritis, and to identify patient subgroups that may benefit most from each technique.

Secondary restraints in ACL reconstruction: State-of-the-art

At-risk patients continue to experience a high likelihood of graft rupture after anterior cruciate ligament (ACL) reconstruction (ACLR). This narrative review seeks to provide the reader with an evidence-based synopsis of state-of-the-art concepts related to secondary restraint lesions, and how addressing them surgically might result in improved outcomes of ACLR.

An Update on Emerging Techniques and Considerations in Revision Anterior Cruciate Ligament Reconstruction

» The rate of primary anterior cruciate ligament reconstruction (ACLR) failure in at-risk populations remains unacceptably high and necessitates thorough evaluation of native alignment and concomitant injuries.» Posterior tibial slope of >12° is a substantial risk factor of ACLR failure and should be corrected through anterior closing wedge osteotomy.» Varus malalignment of >5° exacerbates stress on the ACL graft, increases ACLR failure risks, and should be considered for correction through high tibial osteotomy at the time of revision ACLR.» Injuries to the anterolateral ligamentous complex are prevalent in ACL ruptures, and high-risk patients have shown benefit from anterolateral ligament reconstruction or lateral extra-articular tenodesis in the revision setting.» Addressing posterolateral corner, collateral ligament, and meniscal injuries, during revision ACLR, is vital to mitigate increased graft forces and optimize knee stability and functional outcomes.

A High Grade of Postoperative Knee Laxity Is Associated With an Increased Hazard of Revision Surgery: A Cohort Study of 4697 Patients With Primary ACL Reconstruction

BACKGROUND

There is still debate regarding the association between arthrometric knee laxity measurements and subjective knee outcome and revision surgery after primary anterior cruciate ligament reconstruction (ACLR).

PURPOSE

To assess whether arthrometric knee laxity (measured with the KT-1000 arthrometer) 6 months after primary ACLR was associated with the 1-, 2-, and 5-year subjective knee outcomes or revision ACLR at a 5-year follow-up.

STUDY DESIGN

Cohort study, Level of evidence 3.

METHODS

Patients who underwent primary ACLR with a hamstring tendon autograft at the authors' institution between January 1, 2005, and December 31, 2017, with no concomitant ligamentous injuries, were identified. Anterior knee laxity (KT-1000 arthrometer, 134 N) was assessed 6 months postoperatively. The Knee injury and Osteoarthritis Outcome Score (KOOS) was collected preoperatively and 1, 2, and 5 years postoperatively. Patients who underwent revision ACLR at any institution in the country within 5 years of primary surgery were identified through the Swedish National Knee Ligament Registry.

RESULTS

A total of 4697 patients (54.3% male) with available KT-1000 arthrometer measurements were included (normal: side-to-side [STS] ≤2 mm, 3015 [64.2%]; nearly normal: STS 3-5 mm, 1446 [30.8%]; abnormal: STS >5 mm, 236 [5.0%]). The only significant difference in subjective knee outcome between the groups was for the KOOS Symptoms subscale at the 1-year follow-up (STS ≤2 mm, 79.9 ± 16.2; STS 3-5 mm, 82.5 ± 14.8; STS >5 mm, 85.1 ± 14.2; P < .001). No other significant differences between the groups were found preoperatively or at 1, 2, or 5 years postoperatively for any of the KOOS subscales. The hazard for revision ACLR within 5 years of the primary surgery was significantly higher for the groups with an STS of 3 to 5 mm (6.6%; 95/1446) (hazard ratio [HR], 1.42; 95% CI, 1.07-1.87; P = .01) and an STS >5 mm (11.4%; 27/236) (HR, 2.61; 95% CI, 1.69-4.03; P < .001) compared with the group with an STS ≤2 mm (3.8%; 116/3015).

CONCLUSION

A high grade of postoperative knee laxity (STS 3-5 mm and STS >5 mm) 6 months after primary ACLR was associated with an increased hazard of revision ACLR within 5 years, but it was not associated with an inferior subjective knee outcome.

The Addition of the Gracilis Tendon to a Semitendinosus Tendon Autograft Is Not Associated With Knee Muscle Strength, Subjective Knee Function, or Revision Surgery After Anterior Cruciate Ligament Reconstruction

PURPOSE

To evaluate and compare isokinetic knee muscle (extension and flexion) strength, single-leg hop (SLH) test performance, anterior knee laxity, subjective knee function, and the 2-year revision surgery risk between patients who underwent anterior cruciate ligament reconstruction (ACLR) with semitendinosus tendon (ST) autografts and patients who underwent ACLR with ST and gracilis tendon (ST-G) autografts.

METHODS

We identified patients aged 16 years or older who underwent primary ACLR with hamstring tendon autografts at our institution from January 2005 to December 2020 and had no associated ligament injuries. Isokinetic knee muscle strength and SLH test performance were assessed 6 months postoperatively. Anterior knee laxity (KT-1000 arthrometer, 134 N) was assessed preoperatively and 6 months postoperatively. The Knee Injury and Osteoarthritis Outcome Score (KOOS) was collected preoperatively and 1 and 2 years postoperatively. Patients who underwent revision ACLR at any institution in Sweden within 2 years of primary surgery were identified through the Swedish National Knee Ligament Registry.

RESULTS

A total of 6,974 patients (5,479 with ST and 1,495 with ST-G) were included. There were no significant differences in extension and flexion strength or SLH test performance between the groups. Preoperatively, there was no significant difference in knee laxity between the ST and ST-G groups. Postoperatively, the ST-G group had significantly increased mean side-to-side (STS) laxity (2.1 ± 2.3 mm vs 1.7 ± 2.2 mm, P < .001) and showed a trend toward increased STS laxity according to the International Knee Documentation Committee form, with significantly fewer patients with STS laxity of 2 mm or less (58.4% vs 65.8%) and significantly more patients with STS laxity between 3 and 5 mm (35.0% vs 29.9%) or greater than 5 mm (6.6% vs 4.3%) (P < .001). The only significant difference in subjective knee function was for the KOOS Quality of Life subscale score in favor of the ST group preoperatively (37.3 ± 21.4 vs 35.1 ± 19.9, P = .001). No other significant differences between the groups were found preoperatively and 1 and 2 years postoperatively for any of the KOOS subscales. The overall revision ACLR rate within 2 years of primary surgery was 2.0% (138 of 6,974 patients). The revision ACLR risk in the ST-G group (1.7%, 25 of 1,495 patients) was not significantly different from that in the ST group (2.1%, 113 of 5,479 patients) (hazard ratio, 0.80; 95% confidence interval, 0.50-1.24; P = .32).

CONCLUSIONS

The addition of the gracilis tendon to an ST autograft was not associated with knee muscle strength, SLH test performance, subjective knee function, or the risk of revision surgery after ACLR.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Risk factors of knee reinjury after anterior cruciate ligament reconstruction

PURPOSE

This study aimed to investigate whether the return to level I sports, concomitant injuries, foot-related problems, and other factors would increase the risk of knee reinjury after anterior cruciate ligament reconstruction (ACLR).

METHODS

This study used a prospective cohort study design. Online enrolment from August 2018 to January 2019 in ACL Community Indonesia recruited 148 patients who had undergone ACLR less than one month prior to injury. Knee injury occurrence after ACLR was diagnosed through a physical examination and positive MRI or arthroscopic findings.

RESULTS

During the study, 55 knee reinjuries occurred. The proportional hazards model analysis revealed that the risk of knee reinjury at 12 and 24 months for patients who returned to level I sports (hazards ratio (HR)=3.17 and HR=3.90, respectively) was significantly higher than that of the patients who did not return to sports and that the risk for those who returned to level II/III sports did not significantly increase at 12 or 24 months. Patients with concomitant meniscus injury had a significantly higher risk of knee reinjury at 12 and 24 months (HR=3.33 and HR=2.25, respectively) than those without, and the risk of knee reinjury for patients with concomitant posterior cruciate ligament injury was significantly higher at 12 months (HR=3.05) but not at 24 months. Fewer knee symptoms after ACLR were significantly associated with a lower risk of knee reinjury (HR=0.98) at 12 and 24 months.

CONCLUSIONS

The return to level I sports, concomitant meniscus and posterior cruciate ligament injury, and knee symptoms after ACLR may increase the risk of knee reinjury for post-ACLR patients.

Increased Intra-Articular Internal Tibial Rotation Is Associated With Unstable Medial Meniscus Ramp Lesions in ACL-Injured Athletes: An MRI Matched-Pair Comparative Study

Purpose

To analyze internal tibial rotation through magnetic resonance imaging (MRI) of patients with anterior cruciate ligament (ACL) injuries with and without an unstable medial meniscal ramp lesion (MMRL).

Methods

Retrospective analysis of prospectively data was performed to include all consecutive patients who underwent primary ACL reconstruction (ACLR) between January 2022 and June 2022. Two groups, ACLR + unstable MMRL and ACLR without MMRL, were constituted. Propensity score matching analysis was used to limit selection bias. The angle between surgical epicondylar axes (SEAs) and the tangent line of the posterior tibial condyles (PTCs) was measured to analyze the rotational alignment between distal femur and proximal tibia. MMRLs were defined unstable if they were ≥1 cm, if the lesions extend beyond the lower pole of the femoral condyle, and/or if there was displacement into the medial compartment by anterior probing.

Results

Twenty-eight propensity-matched pairs were included. The ACLR + unstable MMRL presented a significantly greater internal rotation of the tibia compared to ACLR without MMRL (P < .001). An internal tibial rotation was associated with unstable ramp lesions in ACL-injured patients (odds ratio [OR], 0.36; 95% CI, 0.25-0.41; P < .0001). If SEA-PTC was 0°, the sensitivity and specificity of the SEA-PTC angle to detect unstable MMRL were respectively 100% (95% CI, 85%-100%) and 18% (95% CI, 8%-36%). Otherwise, if SEA-PTC angle was -10°, the sensitivity and specificity of the SEA-PTC angle to detect unstable MMRL were respectively 43% (95% CI, 27%-61%) and 96% (95% CI, 81%-100%). Bone edema of the posterior medial tibial plateau was significantly associated with unstable ramp lesions (OR, 1.58; 95% CI, 1.21-2.06; P = .029).

Conclusions

Unstable MMRL concomitant to an ACL rupture was associated with an increased tibial internal rotation.

Level of Evidence

Level III, retrospective comparative trial.

Re-rupture rate and the post-surgical meniscal injury after anterior cruciate ligament reconstruction with the Press-Fit-Hybrid®-technique in comparison to the interference screw technique: a retrospective analysis of 200 patients with at least 3 years follow-up

BACKGROUND

There is currently no consensus regarding the preferred surgical procedure for the reconstruction of anterior cruciate ligament (ACL). The interference screw technique is widely used, but has been associated with a risk of graft damage. The Press-Fit-Hybrid®-technique is one of the alternatives for biological ACL-reconstruction with minimal implant requirements. The hypothesis of this retrospective analysis is, that the Press-Fit-Hybrid®-technique leads to better results with respect to re-rupture rate and secondary meniscal lesion than the interference-screw-technique.

METHODS

To compare the re-rupture rate of the interference-screw-technique (IF) used until 2015 with the currently used Press-Fit-Hybrid®-technique (PFH), the last 100 patients of the IF-group and the first 100 patients of the PFH-group were retrospectively analyzed. Primary outcomes were re-rupture rate, complications and secondary meniscal injury. Additionally, laxity, Lachman and Pivot-shift and range of motion were evaluated.

RESULTS

A mean follow-up of 4.2 and 5.3 years revealed 4% and 9% re-rupture rates and 1% and 2% complication rates in the PFH- and IF-group, respectively. In the PFH-group there were no re-ruptures in patients older than 23 years. Secondary meniscal injury post-surgery was 6% and 9% for the PFH and IF-group, respectively. Knee stability was similar in both groups. Range of motion was significantly better in the PFH-group, with 136° of flexion, 6 months after surgery.

CONCLUSION

For ACL-reconstruction the Press-Fit-Hybrid®-technique is an alternative new method. Low level of secondary meniscal lesions after surgery and high stability, is known to prevent later arthrosis of the knee. The encouraging observed trend of the reduction of the re-rupture rate in revision surgery and in young patients using the Press-Fit-Hybrid®-technique in comparison to the interference-screw-technique must be confirmed with further studies.

LEVEL OF EVIDENCE

Therapeutic Level III, retrospective cohort study.

Diagnosis of medial meniscal ramp lesion is difficult by pre-operative magnetic resonance imaging evaluation and needs a methodical arthroscopic exploration

BACKGROUND

Meniscal ramp lesion (RL) is the peripheral lesion of the posterior horn of the medial meniscus (PHMM) associated with anterior cruciate ligament (ACL) tear. The purpose of this study was to evaluate the accuracy of pre-operative magnetic resonance imaging (MRI) evaluation in diagnosing RL and to identify whether the difficulty in diagnosis differs depending on the location of RL.

METHODS

ACL-injured patients undergoing ACL reconstruction from January 2017 to January 2019 were enrolled. A methodical arthroscopic exploration to identify RL was conducted intra-operatively using three steps, namely, the anterior visualization step, the inter-condylar visualization step, and the posteromedial step. The location of the RLs was evaluated and classified into two types as follows: Red-red zone (RR) - a meniscal tear of the red-red zone of the PHMM. Menisco-capsular junction (MCJ) - a lesion at the menisco-capsular junction of the PHMM, which is more peripheral than RR. Furthermore, the accuracy of 1.5-T MRI evaluation to diagnose RL by two testers using sagittal proton-density fat-saturated images was calculated.

RESULTS

Of the 81 patients enrolled, 11 had RL: 5 cases each were at the MCJ and RR, and 1 case was at both locations. The sensitivity of MRI for detecting RL was 27.3-45.5%, whereas the specificity was 84.3-95.7% in total. The sensitivity of MRI in detecting RL at the RR and MCJ was 40.0-80.0%, 0-20.0%, respectively. The intra-observer reliability of the MRI evaluation was moderate (κ coefficient: 0.40-0.46), while the inter-observer reliability was fair to moderate (κ coefficient: 0.27-0.41).

CONCLUSIONS

A low sensitivity of the MRI in detecting RL at the MCJ was observed, and the reliability of the MRI evaluation for diagnosis of RL was not high. Therefore, methodical arthroscopic exploration is essential to diagnose RL even when it is not suspected on pre-operative MRI.

Meniscal repair at the time of primary ACLR does not negatively influence short term knee stability, graft rupture rates, or patient-reported outcome measures: the STABILITY experience

PURPOSE

To assess how meniscal repair and excision impact short term patient-reported outcome measures (PROMs), knee stability, and early graft rupture rates following primary hamstring anterior cruciate ligament reconstruction (ACLR) with or without lateral extra-articular tenodesis (LET) in a group of young active patients where meniscal repair is commonly advocated.

METHODS

Six hundred and eighteen patients under 25 years of age at high-risk of graft failure following ACLR were recruited to the Stability 1 study. Multivariable regression models were developed to identify statistically and clinically significant surgical and demographic predictors of Knee Injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee Subjective Knee Form (IKDC), ACL Quality of Life Questionnaire (ACL-QOL) and Marx Activity Rating Scale (MARS) scores. Chi-Square tests of independence were used to explore the association between meniscal status (torn, not torn), meniscal treatment (excision or repair), graft rupture, and rotatory knee laxity.

RESULTS

Medial meniscus repair was associated with worse outcomes on the KOOS (β = -1.32, 95% CI: -1.57 to -1.10, p = 0.003), IKDC (β = -1.66, 95% CI: -1.53 to -1.02, p = 0.031) and ACL-QOL (β = -1.25, 95% CI: -1.61 to 1.02, p = n.s.). However, these associations indicated small, clinically insignificant changes based on reported measures of clinical relevance. Other important predictors of post-operative PROMs included age, sex, and baseline scores. Medial meniscus excision and lateral meniscus treatment (repair or excision) did not have an important influence on PROMs. There was no significant association between meniscal treatment and graft rupture or rotatory knee laxity.

CONCLUSION

While repairing the medial meniscus may result in a small reduction in PROM scores at two-year follow-up, these differences are not likely to be important to patients or clinicians. Any surgical morbidity associated with meniscal repair appears negligible in terms of PROMs. Meniscal repair does not affect rotatory laxity or graft failure rates in the short term. Therefore, meniscal repair should likely be maintained as the standard of care for concomitant meniscal tears with ACLR.

LEVEL OF EVIDENCE

III.

High-grade pivot-shift phenomenon after anterior cruciate ligament injury is associated with asymmetry of lateral and medial compartment anterior tibial translation and lateral meniscus posterior horn tears

PURPOSE

To investigate whether the high-grade pivot-shift phenomenon is associated with asymmetry of the lateral and medial compartment anterior tibial translation (L-ATT and M-ATT) and lateral meniscus posterior horn (LMPH) tears in anterior cruciate ligament (ACL) injuries.

METHODS

A retrospective analysis was performed on 192 consecutive patients who had complete ACL injuries between January 2019 and December 2020. Among these, 156 met the inclusion criteria. L-ATT and M-ATT were measured using preoperative weight-bearing magnetic resonance imaging (MRI), and the differences between L-ATT and M-ATT were calculated. Thirty-five patients who demonstrated excessive differences in L-ATT and M-ATT (> 6.0 mm) were regarded as asymmetric (study group), and 36 patients with minimal or no differences in L-ATT and M-ATT (< 3.0 mm) were allocated to the control group. Demographic data, grade of the pivot-shift test, integrality of LMPH, and medial meniscus posterior horn (MMPH) were compared between the groups. Moreover, predictors of high-grade pivot-shift phenomenon, including asymmetry of L-ATT and M-ATT, integrity of LMPH and MMPH, time from injury to surgery, sex, age, and body mass index (BMI) were assessed using multivariable logistic regression analysis.

RESULTS

The difference between L-ATT and M-ATT in the study group was significantly higher than that in the control group (mean ± SD: 8.4 ± 2.1 mm vs. 1.5 ± 1.0 mm, P < 0.001). A higher proportion of patients with high-grade pivot-shift phenomenon (2 + and 3 +) and LMPH tears were identified in the study group (high-grade pivot-shift phenomenon: 25/35 vs. 13/36, P = 0.003; LMPH tears: 18/35 vs. 5/36, P = 0.001). Additionally, asymmetry of L-ATT, M-ATT (odds ratio 5.8; 95% CI 1.7-19.8; P = 0.005), and LMPH tears (odds ratio 3.8; 95% CI 1.3-11.6; P = 0.018) were found to be good predictors of the high-grade pivot-shift phenomenon after ACL injury, whereas MMPH tears, time from injury to surgery, sex, age, and BMI were not.

CONCLUSION

In patients with ACL injury, the high-grade pivot-shift phenomenon is associated with asymmetry between L-ATT and M-ATT, and LMPH tears.

LEVEL OF EVIDENCE

III.

Risk Factors for Anterior Cruciate Ligament Graft Failure in Professional Athletes: An Analysis of 342 Patients With a Mean Follow-up of 100 Months From the SANTI Study Group

BACKGROUND

Anterior cruciate ligament (ACL) injuries are among the most common knee injuries sustained in elite sport, and athletes generally undergo ACL reconstruction (ACLR) to facilitate their return to sport. ACL graft rupture is a career-threatening event for elite athletes.

PURPOSE/HYPOTHESIS

The purpose of this study was to determine the risk factors for graft failure in professional athletes undergoing ACLR. It was hypothesized that athletes who underwent combined ACLR with a lateral extra-articular procedure (LEAP) would experience significantly lower rates of graft rupture in comparison with those who underwent isolated ACLR.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Professional athletes who underwent primary ACLR with a minimum follow-up of 2 years were identified from the Santy database. Patients were excluded if they underwent major concomitant procedures, including multiligament reconstruction surgery or osteotomy. Further ipsilateral knee injury, contralateral knee injury, and any other reoperations or complications after the index procedure were identified by interrogation of the database and review of the medical notes.

RESULTS

A total of 342 athletes with a mean follow-up of 100.2 ± 51.9 months (range, 24-215 months) were analyzed. Graft failures totaling 31 (9.1%) were reported, requiring revision surgery because of symptomatic instability. The rate of graft failure was significantly higher when ACLR was not combined with a LEAP (15.5% vs 6.0%; P = .0105) and in athletes aged 21 years or younger (13.8% vs 6.6%; P = .0290). A multivariate analysis was performed using the Cox model and demonstrated that athletes undergoing an isolated ACLR were at >2-fold risk of ACL graft rupture (hazard ratio [HR], 2.678 [1.173; 4.837], P = .0164) when compared with those undergoing a combined ACLR with a LEAP. Additionally, athletes aged ≤21 years were also at >2-fold risk of graft failure (HR, 2.381 [1.313; 5.463]; P = .0068) than those aged >21 years. Sex, sport, and graft type were not found to be significant risk factors for graft failure.

CONCLUSION

Professional athletes undergoing isolated ACLR and aged ≤21 years are at >2-fold greater risk of graft failure. Orthopaedic surgeons treating elite athletes should combine an ACLR with a LEAP to improve ACL graft survivorship.

The presence of high-grade pivot shift test preoperatively is associated with inferior functional outcomes

BACKGROUND

The effect of high-grade preoperative pivot shift test on outcomes of anterior cruciate ligament (ACL) reconstruction surgery is not very well established. The present study was conducted to study the factors associated with high-grade pivot shift test and effect of high-grade preoperative pivot shift test on functional outcomes after ACL reconstruction surgery.

METHODS

Three hundred and sixty-two patients who underwent primary ACL reconstruction surgery were enrolled in the study. The pivot shift test was performed preoperatively under anesthesia in all patients. Side of the meniscal tear, if present at the time of ACL reconstruction, was documented. Patients were divided into two groups depending upon the grade of pivot shift test: group H, high-grade pivot shift (n = 84/362; 23%); and group L, low-grade pivot shift (n = 278/362; 77%). Patients were further divided into two groups depending upon the duration of injury: acute (<6 months) and chronic (>6 months). The functional assessment was done using Lysholm score and Tegner activity scale.

RESULTS

The presence of lateral meniscus tear (27/84 vs. 53/278) or both menisci tear (29/84 vs. 60/278) was associated with high-grade pivot shift (p < 0.05). Chronic ACL tears were also observed to be associated with high-grade pivot shift (p = 0.03). The mean Lysholm score in group H and group L patients was 93.8 ± 5.1 and 95.2 ± 5.3, respectively (p = 0.04). The mean post-op Tegner activity scale in group H was 6.8 and in group L was 7.3 (p = 0.0001). Also, 181/253 (71.5%) patients returned to same or higher level of sports activity in group L as compared to 33/72 (46%) patients in group H. The incidence of graft failure in groups H and L was 6.5% (5/77) and 1.6% (4/257; p = 0.03), respectively.

CONCLUSIONS

The high-grade pivot shift is associated with chronic ACL tear (>6 months) and concomitant lateral meniscus tear. The presence of high-grade pivot shift preoperatively is associated with inferior clinical outcomes and lower rate of return to sports.

LEVEL OF EVIDENCE

Level IV, case-control study.

Risk of Graft Rupture After Adding a Lateral Extra-articular Procedure at the Time of ACL Reconstruction: A Retrospective Comparative Study of Elite Alpine Skiers From the French National Team

BACKGROUND

Elite alpine skiing is associated with a particularly high risk of anterior cruciate ligament (ACL) injuries, including graft ruptures. Despite a considerable focus on prevention, a reduction in injury rates has not been observed since the 1980s.

PURPOSE

To determine whether elite alpine skiers undergoing ACL reconstruction (ACLR) with a lateral extra-articular procedure (LEAP) had a lower rate of ACL graft rupture when compared with those who underwent isolated ACLR.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Elite skiers from the French ski team who had undergone ACLR, with or without a LEAP, and had a minimum follow-up of 2 years were identified from the national ski team database. Rates of secondary ACL injury were determined via interrogation of the database, review of medical notes, and a final telemedicine interview. A multivariable analysis using the penalized Cox model was performed to explore the relationship among graft rupture, surgical procedure type, and any potential explanatory variables.

RESULTS

Among 81 ACLR procedures analyzed, 50 were isolated and 31 were combined with a LEAP, which was performed using modified Lemaire or anterolateral ligament reconstruction. Graft rupture rates were 34.0% in the isolated ACLR group and 6.5% in the ACLR + LEAP group. Multivariable analysis demonstrated that adding a LEAP was associated with a significant reduction in risk of ACL graft rupture when compared with isolated ACLR (hazard ratio [HR], 5.286 [95% CI, 1.068-26.149]; P = .0412). Age (HR, 1.114; P = .1157), sex (HR, 1.573; P = .3743), and ACL graft type (HR, 1.417; P = .5394) were not significant risk factors.

CONCLUSION

Combined ACLR and LEAP were associated with a significant reduction in the rate of ACL graft rupture in elite alpine ski athletes. Those treated with isolated ACLR remain at extremely high risk of a second ACL injury.

Predictors of Graft Failure in Young Active Patients Undergoing Hamstring Autograft Anterior Cruciate Ligament Reconstruction With or Without a Lateral Extra-articular Tenodesis: The Stability Experience

BACKGROUND

Anterior cruciate ligament (ACL) reconstruction (ACLR) has higher failure rates in young active patients returning to sports as compared with older, less active individuals. Augmentation of ACLR with an anterolateral procedure has been shown to reduce failure rates; however, indications for this procedure have yet to be clearly defined.

PURPOSE/HYPOTHESIS

The purpose of this study was to identify predictors of ACL graft failure in high-risk patients and determine key indications for when hamstring ACLR should be augmented by a lateral extra-articular tenodesis (LET). We hypothesized that different preoperative characteristics and surgical variables may be associated with graft failure characterized by asymmetric pivot shift and graft rupture.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Data were obtained from the Stability 1 Study, a multicenter randomized controlled trial of young active patients undergoing autologous hamstring ACLR with or without a LET. We performed 2 multivariable logistic regression analyses, with asymmetric pivot shift and graft rupture as the dependent variables. The following were included as predictors: LET, age, sex, graft diameter, tear chronicity, preoperative high-grade knee laxity, preoperative hyperextension on the contralateral side, medial meniscal repair/excision, lateral meniscal repair/excision, posterior tibial slope angle, and return-to-sports exposure time and level.

RESULTS

Of the 618 patients in the Stability 1 Study, 568 with a mean age of 18.8 years (292 female; 51.4%) were included in this analysis. Asymmetric pivot shift occurred in 152 (26.8%) and graft rupture in 43 (7.6%). The addition of a LET (odds ratio [OR], 0.56; 95% CI, 0.37-0.83) and increased graft diameter (OR, 0.62; 95% CI, 0.44-0.87) were significantly associated with lower odds of asymmetric pivot shift. The addition of a LET (OR, 0.40; 95% CI, 0.18-0.91) and older age (OR, 0.83; 95% CI, 0.72-0.96) significantly reduced the odds of graft rupture, while greater tibial slope (OR, 1.15; 95% CI, 1.01-1.32), preoperative high-grade knee laxity (OR, 3.27; 95% CI, 1.45-7.41), and greater exposure time to sport (ie, earlier return to sport) (OR, 1.18; 95% CI, 1.08-1.29) were significantly associated with greater odds of rupture.

CONCLUSION

The addition of a LET and larger graft diameter were significantly associated with reduced odds of asymmetric pivot shift. Adding a LET was protective of graft rupture, while younger age, greater posterior tibial slope, high-grade knee laxity, and earlier return to sport were associated with increased odds of graft rupture. Orthopaedic surgeons should consider supplementing hamstring autograft ACLR with a LET in young active patients with morphological characteristics that make them at high risk of reinjury.

Anterior cruciate ligament reconstruction with lateral extraarticular tenodesis better restores native knee kinematics in combined ACL and meniscal injury

PURPOSE

To determine if anterior cruciate ligament (ACL) reconstruction (ACLR) with lateral extraarticular tenodesis (LET) is beneficial for restoring knee kinematics with concomitant meniscal pathology causing rotatory knee instability.

METHODS

Twenty patients with an ACL tear were randomized to either isolated ACLR or ACLR with LET. Patients were divided into four groups based on the surgery performed and the presence of meniscal tear (MT): ACLR without MT, ACLR with MT, ACLR with LET without MT, and ACLR with LET with MT. Kinematic data normalized to the contralateral, healthy knee were collected using dynamic biplanar radiography superimposed with high-resolution computed tomography scans of patients' knees during downhill running. Anterior tibial translation (ATT) and tibial rotation (TR) as well as patient-reported outcome measures (PROMs) were analyzed at 6- and 12-months postoperatively.

RESULTS

At 6 months, ACLR with LET resulted in significantly decreased ATT at heel strike compared to ACLR (ACLR without MT: 0.3 ± 0.8 mm and ACLR with MT: 1.4 ± 3.1 mm vs. ACLR with LET without MT: - 2.5 ± 3.4 mm and ACLR with LET with MT: - 1.5 ± 1.2 mm ATT, p = 0.02). At 6 months, at toe off ACLR with LET better restored ATT to that of the contralateral, healthy knee in patients with meniscal pathology, while in patients without meniscal pathology, ACLR with LET resulted in significantly decreased ATT (1.0 ± 2.6 mm ATT vs. - 2.6 ± 1.7 mm ATT, p = 0.04). There were no significant differences in kinematics or PROMs between groups at 12 months.

CONCLUSION

For combined ACL and meniscus injury, ACLR with LET restores native knee kinematics at toe off but excessively decreases ATT at heel strike in the early post-operative period (6 months) without altering knee kinematics in the long term. Future large-scale clinical studies are needed to better understand the function of LET and ultimately improve patient outcomes.

LEVEL OF EVIDENCE

III.

Physical prognostic factors predicting outcome following anterior cruciate ligament reconstruction: A systematic review and narrative synthesis

BACKGROUND

Anterior cruciate ligament (ACL) injuries are common. Many patients undergo ACL reconstruction (ACLR), with rehabilitation key to successful outcome. Understanding physical prognostic factors is integral to clinical decision-making, but factors predicting outcome are inadequately defined. The objective was to establish physical prognostic factors predicting outcome following ACLR.

METHODS

A systematic review following a published protocol (CRD42019127732) searched MEDLINE, CINAHL, EMBASE, key journals and grey literature to November 28, 2020. Prospective cohort studies, participants ≥16 years of age who had undergone ACLR were included, with multi-ligament and/or ACL repair surgery, and studies not published in English excluded. Two independent reviewers conducted searches, extracted data, assessed risk of bias (QUIPS) and overall quality of evidence (GRADE). Meta-analysis was not possible, therefore narrative synthesis was performed.

RESULTS

13 studies (16 articles) were included (1 low, 12 high risk of bias). Low-level evidence supports postoperative degenerative changes and poor lower-limb strength predicting poorer outcome long term (KOOS). Very low-level evidence supports greater postoperative quadriceps strength predicting improved functional performance medium term; with lower body mass index predicting improvement of multiple outcome measures.

CONCLUSION

Limited evidence of low or very low-level indicates multiple prognostic factors predicting outcome following ACLR. A high-quality prognostic study is required.

A Surgical Algorithm According to Pivot-Shift Grade in Patients With ACL Injury: A Prospective Clinical and Radiological Evaluation

Background:

Some patients have a positive pivot-shift finding and rotational instability after anterior cruciate ligament (ACL) reconstruction (ACLR). Three major pathologies known to affect the pivot-shift examination include ACL tear, anterolateral ligament injury, and loss of posterior lateral meniscus root function.

Purpose:

To describe a surgical algorithm determining indications for lateral extra-articular tenodesis (LET) based on intraoperative pivot-shift examination to prevent postoperative pivot shift and rotational instability and to evaluate the 2-year clinical and functional outcomes.

Study Design:

Case series; Level of evidence, 4.

Methods:

The study included 47 consecutive patients (39 men and 8 women) who underwent operative treatment for ACL injury between 2016 and 2017. Pivot-shift examination was performed under anesthesia, and the pivot shift was graded as grade 1 (glide), grade 2 (clunk), or grade 3 (gross). According to the surgical algorithm, single-bundle ACLR was performed in patients with grade 1 pivot shift. In patients with grade 2 with loss of posterior lateral meniscus root function, concurrent lateral meniscal repair was performed, and in patients with grade 2 with an intact lateral meniscus posterior root, concurrent extra-articular iliotibial band tenodesis was performed. Patients with grade 3 underwent ACLR, lateral meniscal repair, and LET. Clinical and radiographic evaluations were performed.

Results:

The mean age was 27.2 years (range, 16-56 years). In total, 26 (55.3%) patients were evaluated as having pivot-shift grade 1; 16 (34%) patients, grade 2; and 5 (10.6%) patients, grade 3. A total of 7 (14.9%) patients underwent LET in addition to ACLR. Two of these patients had pivot-shift grade 2, and LET was performed since the lateral meniscus posterior root was intact. In 14 of 16 patients with grade 2, lateral meniscus root disruption was detected, and lateral meniscal repair was performed. One patient was excluded from the further follow-up because of graft failure. At a mean postoperative follow-up of 29 months in 46 patients, the pivot-shift examination was negative in all patients. The mean Lysholm and International Knee Documentation Committee subjective scores were 95.35 ± 4.40 and 82.87 ± 9.36, respectively. Radiographic evidence of osteoarthritis was not detected.

Conclusion:

Only 14.9% of patients needed LET. With proper ACL, lateral meniscal, and anterolateral ligament surgery, it was possible to prevent positive pivot-shift findings postoperatively.

Multiple ACL Revision: Failure Analysis and Clinical Outcomes

Anterior cruciate ligament (ACL) reconstruction represents one of the most successful orthopedic surgical procedures. Nevertheless, ACL revisions are still very frequent, with a small but relevant number of failures. The purpose of this study is to analyze the failure causes and the clinical outcomes of patients who underwent a re-revision ACL reconstruction. Between January 2009 and December 2017, 263 ACL revisions were performed by a single senior surgeon. Seventeen patients (12 males and 5 females) underwent re-revision ACL reconstruction meeting the inclusion criteria. The mean age was 28.4 years (range, 19-41 years). Before the re-revision, the patients were evaluated preoperatively and after a mean follow-up of 29 months (range, 13-58 months). Assessment included subjective and objective evaluations (Lysholm and International Knee Documentation Committee [IKDC]), KT-2000 arthrometer, radiographic study, and preoperative computed tomography scan. Five patients showed a too anterior previous femoral tunnel and seven a too vertical and posterior tibial tunnel; eight meniscal tears were found. Five patients had grade III-IV according to Outerbridge cartilage lesions. IKDC showed a statistically significant improvement (A + B 35%, C + D 65% preop, A + B 82%, C + D 18% postop, odds ratio: 0.1169; p = 0.0083). The mean Lysholm score ranged from 43 ± 9 to 87 ± 7 (p < 0.001). The KT-2000 arthrometer showed a statistically significant improvement from a mean of 5.8 ± 1.4 to 1.5 ± 1.1 (p < 0.001) at last follow-up. Out of 17 patients, only 4 returned to sports activity at the same preinjury levels. Postoperatively at the last follow-up after last revision surgery, no osteoarthritis evolution was observed. This study showed good clinical and radiological results after the last revision ACL surgery in patients with multiple failures of ACL reconstruction but only one-fourth of the patients returned to the same preoperative sport level. Traumatic events, technical errors, and untreated peripheral lesions are the main causes of multiple previous failures; the worst clinical outcomes were found in the patients with high grade of chondral lesions.

Double-Bundle Anterior Cruciate Ligament Reconstruction With Lateral Extra-Articular Tenodesis Is Effective in Restoring Knee Stability in a Chronic, Complex Anterior Cruciate Ligament-Injured Knee Model: A Cadaveric Biomechanical Study

PURPOSE

To compare knee stability after intra-articular isolated double-bundle (DB) anterior cruciate ligament reconstruction (ACLR) and single-bundle (SB) and DB ACLR combined with lateral extra-articular tenodesis (LET) in a chronic, complex anterior cruciate ligament (ACL)-injured knee model.

METHODS

In 10 fresh-frozen cadaveric knees, we measured knee laxity in the following order: (1) intact knee; (2) ACL-sectioned knee; (3) complex ACL-injured knee model with additional sectioning of the anterolateral complex and the posterior horns of the medial and lateral menisci; (4) SB ACLR plus LET; (5) DB ACLR; and (6) DB ACLR plus LET.

RESULTS

In comparison with the intact knee, significantly increased internal rotation (IR) laxity persisted at 60° and 90° after DB ACLR (P = .002 and P = .003, respectively). SB ACLR plus LET and DB ACLR plus LET resulted in significant reductions in IR laxity at 90° (P = .003 and P = .037, respectively), representing overconstraint in IR. SB ACLR plus LET resulted in persistently increased external rotation (ER) laxity at 30°, 60°, and 90° (P = .001, P < .001, and P < .001, respectively). The DB ACLR condition persistently showed significant increases in anterior tibial translation laxity at 60° and 90° (P = .037 and P = .024, respectively). A greater increase in ER laxity was seen after SB ACLR plus LET versus DB ACLR plus LET at 30°, 60°, and 90° (P < .001, P < .001, and P < .001, respectively).

CONCLUSIONS

DB ACLR plus LET restored intact knee stability in IR, ER, and anterior tibial translation laxity at 0°, 30°, 60°, and 90° of knee flexion except for overconstraint in IR at 90° in a chronic, complex ACL-injured knee model.

CLINICAL RELEVANCE

This cadaveric study provides some biomechanical evidence to support performing DB ACLR combined with LET to restore knee stability after a complex, chronic knee injury involving an ACL tear combined with anterolateral complex injury and irreparable tears of the posterior horns of the medial and lateral menisci.

Prediction of improvement after anterior cruciate ligament reconstruction

Objective

The retrospective investigation was carried out to assess whether subjects who fulfilled our proposed recruitment criteria responded more favorably to anterior cruciate ligament reconstruction (ACLR) than those who did not.

Methods

We retrospectively analyzed 109 skeletally mature subjects (78 men and 31 women) according to the following proposed criteria of recruitment: (1) pre-injury Tegner activity score ≥7 and a wish to return to a professional sports activity, (2) residual knee instability following injury and/or (3) age <20 years at the operation. The primary outcome was an improvement between assessment A (before operation) and B (mean follow-up of 1.6 years) in the average score for four of the five Knee injury and Osteoarthritis Outcome Score (KOOS) subscales, covering pain, symptoms, difficulty in sports and recreational activities, and quality of life (KOOS₄).

Results

The proposed recruitment criteria for ACLR were met by 58 subjects (53%). There were 49 subjects (45%) who improved between assessment A and B. Subjects who met proposed recruitment criteria were more likely to improve clinically after ACLR (OR 5.7, 95% CI 2.5–13.3).

Conclusions

Fulfillment of proposed recruitment criteria was a strong predictive factor for outcome improvement in short- to medium-term follow-up after ACLR.

Level of evidence

Case-control study. Level of evidence 3.

Aseptic Revision and Reoperation Risks After Meniscectomy at the Time of Anterior Cruciate Ligament Reconstruction

BACKGROUND

An intact meniscus is considered a secondary stabilizer of the knee after anterior cruciate ligament reconstruction (ACLR). While loss of the meniscus can increase forces on the anterior cruciate ligament graft after reconstruction, it is unclear whether this increased loading affects the success of the graft after ACLR.

PURPOSE

To identify the risk of subsequent knee surgery when meniscectomy, either partial or total, is performed at the time of index ACLR.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

We conducted a matched cohort study using data from the Kaiser Permanente Anterior Cruciate Ligament Reconstruction Registry. Patients were identified who had a primary ACLR performed between January 1, 2005 and December 31, 2016, with up to 12 years of follow-up. The study sample comprised patients with ACLR who had a lateral meniscectomy (n = 2581), medial meniscectomy (n = 1802), or lateral and medial meniscectomies (n = 666). For each meniscectomy subgroup, patients with ACLR alone were matched to patients with a meniscectomy on a number of patient and procedure characteristics. After the application of matching, Cox proportional hazards regression was used to evaluate the risk of aseptic revision, while competing risks regression was used to evaluate the risk of cause-specific ipsilateral reoperation between meniscectomy and ACLR alone. Analysis was performed for each meniscectomy subgroup.

RESULTS

After the application of matching, we failed to observe a difference in aseptic revision risk for patients with ACLR and a meniscectomy-lateral (hazard ratio [HR], 0.80; 95% CI, 0.63-1.02), medial (HR, 0.95; 95% CI, 0.70-1.29), or both (HR, 1.25; 95% CI, 0.77-2.04)-as compared with ACLR alone. When compared with patients who had ACLR alone, patients with a lateral meniscectomy had a higher risk for subsequent lateral meniscectomy (HR, 1.89; 95% CI, 1.18-3.02; P = .008), and those with a medial meniscectomy had a lower risk for manipulation under anesthesia (HR, 0.13; 95% CI, 0.02-0.92; P = .041).

CONCLUSION

No difference in aseptic revision risk was observed for patients undergoing primary ACLR between groups with and without meniscectomy at the time of index surgery. Partial lateral meniscectomy at the time of index ACLR did associate with a higher risk of subsequent lateral meniscectomy.

A Systematic Review of Risk Factors for Anterior Cruciate Ligament Reconstruction Failure

Although most studies have introduced risk factors related to anterior cruciate ligament reconstruction failure, studies on combinations of high-risk factors are rare. To provide a systematic review of the risk factors of anterior cruciate ligament reconstruction failure to guide surgeons through the decision-making process, an extensive literature search was performed of the Medline, Embase and Cochrane Library databases. Studies published between January 1, 2009, and September 19, 2019, regarding the existing evidence for risk factors of anterior cruciate ligament reconstruction failure or graft failure were included in this review. Study quality was evaluated with the quality index. Ultimately, 66 articles met our criteria. There were 46 cases classified as technical factors, 21 cases as patient-related risk factors, and 14 cases as status of the knee joint. Quality assessment scores ranged from 14 to 24. This systematic review provides a comprehensive summary of the risk factors for anterior cruciate ligament reconstruction failure, including technical factors, patient-related factors, and the factors associated with the status of the knee joint. Emphasis should be placed on avoiding these high-risk combinations or correcting modifiable risk factors during preoperative planning to reduce the rate of graft rupture and anterior cruciate ligament reconstruction failure.

Indirect Magnetic Resonance Arthrography May Help Avoid Second Look Arthroscopy for Assessment of Healing After Bucket Handle Medial Meniscus Repairs: A Prospective Clinico-Radiological Observational Study

OBJECTIVES

The objectives were: (1) to analyze the MRI healing rates of bucket-handle meniscus repair; (2) to compare the accuracy of assessment of meniscus healing for conventional MRI and Indirect Magnetic Resonance Arthrography (IMRA); and (3) to identify patients who may require second-look arthroscopy after meniscus repair.

METHODS

This is a prospective observational case series of thirty-seven patients with repaired bucket-handle medial meniscus tear with a minimum one year follow-up. Meniscus healing rates were assessed on direct MRI and IMRA using Henning's criteria. At the same time, patients' symptoms were evaluated according to Barrett's criteria and functional outcomes were recorded using International Knee Documentation Committee (IKDC) score, Knee Osteoarthritis and Outcomes Score (KOOS) and Tegner-Lysholm scores. A further clinical review was performed 18 months after the imaging to assess the evolution of symptoms.

RESULTS

At a mean of 22.3 ± 7.8 months after the meniscus repair, 56.7% patients showed complete healing and 40.5% patients demonstrated incomplete repair healing on IMRA. 52% patients with complete healing and 40% patients with incomplete healing demonstrated meniscus symptoms. At the second clinical review, 19% patients with complete healing and 20% patients with incomplete healing had meniscus symptoms. There was no co-relation between symptoms, PROMs and healing on MRI.

CONCLUSION

Indirect MR arthrography offers distinct advantages over direct MRI for assessment of meniscus healing, especially in symptomatic patients. Patient-reported outcome measures and symptomatology are not co-related with the healing status of the meniscus and they resolve in the majority on longer follow-up. A more conservative approach guided by IMRA to assess meniscus healing will avoid early re-operations.

Predictive Value of the Magnetic Resonance Imaging-Based Coronal Lateral Collateral Ligament Sign on Adolescent Anterior Cruciate Ligament Reconstruction Graft Failure

BACKGROUND

The coronal lateral collateral ligament (LCL) sign is the presence of the full length of the LCL visualized on a single coronal magnetic resonance imaging (MRI) slice at the posterolateral corner of the knee. The coronal LCL sign has been shown to be associated with elevated measures of anterior tibial translation and internal rotation in the setting of anterior cruciate ligament (ACL) tear.

HYPOTHESIS

The coronal LCL sign (with greater anterior translation, internal rotation, and posterior slope of the tibia) will indicate a greater risk for graft failure after ACL reconstructive surgery.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Retrospective review was performed of adolescent patients with ACL reconstruction: a cohort without graft failure and a cohort with graft failure. MRI was utilized to measure tibial translation and femorotibial rotation and to identify the coronal LCL sign. The posterior tibial slope was measured on lateral radiographs. Patient-reported outcomes were collected.

RESULTS

We identified 114 patients with no graft failure and 39 patients with graft failure who met all criteria, with a mean follow-up time of 3.5 years (range, 2-9.4 years). Anterior tibial translation was associated with anterolateral complex injury (P < .001) but not graft failure (P = .06). Internal tibial rotation was associated with anterolateral complex injury (P < .001) and graft failure (P = .042). Posterior tibial slope was associated with graft failure (P = .044). The coronal LCL sign was associated with anterolateral complex injury (P < .001) and graft failure (P = .013), with an odds ratio of 4.3 for graft failure (95% CI, 1.6-11.6; P = .003). Subjective patient-reported outcomes and return to previous level of sport were not associated with failure. Comparison of MRI before and after ACL reconstruction in the graft failure cohort demonstrated a reduced value in internal rotation (P = .003) but no change in coronal LCL sign (P = .922).

CONCLUSION

Our study demonstrates that tibial internal rotation and posterior slope are independent predictors of ACL graft failure in adolescents. Although the value of internal rotation could be improved with ACL reconstruction, the presence of the coronal LCL sign persisted over time and was predictive of graft rupture (without the need to make measurements or memorize values of significant risk). Together, these factors indicate that greater initial knee deformity after initial ACL tear predicts greater risk for future graft failure.

Recent Trends in Concomitant Meniscal Procedures During Anterior Cruciate Ligament Reconstruction

BACKGROUND

The chondroprotective effect and secondary stabilizing role of the meniscus has been well-established. Meniscal preservation during anterior cruciate ligament reconstruction (ACLR) has been advocated in the literature and supported by advancements in surgical techniques.

PURPOSE

To examine the recent trends in concomitant partial meniscectomy and meniscal repair procedures with ACLR.

STUDY DESIGN

Descriptive epidemiological study.

METHODS

Patients who underwent arthroscopic meniscectomy (Current Procedural Terminology [CPT] codes 29880, 29881), meniscal repair (CPT codes 29882, 29883), and ACLR (CPT code 29888) between 2010 and 2018 were identified using the National Surgical Quality Improvement Program database. We calculated the proportion of patients who underwent each surgery type, stratified by year and by patient age and body mass index (BMI) groups. The Cochran-Armitage test for trend was used to analyze yearly proportions of concomitant meniscal surgery types.

RESULTS

During the 9-year study period, 22,760 patients underwent either isolated ACLR (n = 10,562) or ACLR with concomitant meniscal surgery (either meniscectomy [n = 8931] or meniscal repair [n = 3267]). There was a gradual decrease in the proportion of meniscectomies (from 80.8% of concomitant procedures in 2010 to 63.8% in 2018), while the proportion of meniscal repairs almost doubled (from 19.2% in 2010 to 36.2% in 2018) (trend, P < .001). ACLR with meniscal repair increased in patients aged 35 to 44 years and 45 to 54 years (trend, P = .027) between 2010 and 2018; at the same time, the proportion of normal weight patients decreased by 17.7%, the proportion of overweight patients increased by 13.2%, and increases were seen in BMI groups corresponding to obesity classes 1 to 3 (trend, P < .001). In 2010, the average BMI of patients undergoing ACLR with meniscectomy versus meniscal repair differed by 2 (P = .004), but by 2018 the difference was nonsignificant (28.83 ± 5.80 vs 28.53 ± 5.73; P = .113).

CONCLUSION

Between 2010 and 2018, there was an upward trend in the proportion of meniscal repairs performed during ACLR, with notable increases in the proportion of repairs being performed on older, overweight, and obese patients.

Single-Stage Revision Anterior Cruciate Ligament Reconstruction: Experience With 91 Patients (40 Elite Athletes) Using an Algorithm

BACKGROUND

The increased prevalence of anterior cruciate ligament (ACL) reconstruction has led to an increased need for revision ACL reconstructions. Despite the growing body of literature indicating that single-stage revision ACL reconstruction can yield good outcomes, there is a lack of data for determining when and how to safely perform a single-stage revision.

PURPOSE

To assess the outcomes, graft failure rates, and return-to-play rates of a decision-making algorithm for single-stage revision ACL reconstruction.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

We reviewed a consecutive series of revision ACL reconstructions performed by the senior author between September 2009 and July 2016 with minimum 2-year follow-up. All patients were assessed, and decision making was undertaken according to the algorithm. Outcomes measured were further surgery, graft rerupture, re-revision, Tegner score, and Knee injury and Osteoarthritis Outcome Score (KOOS). For the elite athlete population, return-to-play time, duration, and level of play after surgery as compared with preinjury were also determined.

RESULTS

During this period, 93 procedures were performed in 92 patients (40 elite athletes). Two 2-stage procedures were undertaken, leaving 91 single-stage procedures (91 patients) to form the basis for further study. At a mean 4.3 years (SD, 2.2 years) after surgery, there had been 2 re-revisions (2.2%) and 2 further instances of graft failure that had not been re-revised (total graft failure rate, 4.4%). There were 17 subsequent procedures, including 6 arthroscopic partial meniscectomies, 5 removals of prominent implants, and 1 total knee arthroplasty. The mean Tegner score was 8.02 before graft rerupture and 7.1 at follow-up. At follow-up, the mean KOOS outcomes were 79.3 for Symptoms, 88.0 for Pain, 94.2 for Activities of Daily Living, 73.6 for Sport, and 68.9 for Quality of Life. Of 40 elite athletes, 35 returned to play at a mean 11.2 months (SD, 3.6 months) after surgery.

CONCLUSION

Single-stage revision ACL reconstructions can be performed reliably in the majority of patients, with good clinical outcomes, low rerupture rates, and high-return-to play rates, even in the elite athlete population.

Meniscal ramp lesions should be considered in anterior cruciate ligament-injured knees, especially with larger instability or longer delay before surgery

PURPOSE

To determine the incidence of meniscal ramp lesions in an anterior cruciate ligament (ACL) injured knees and to clarify whether ramp lesions are related to chronic ACL deficiency and increased knee instability.

METHODS

Consecutive ACL injured patients were evaluated arthroscopically for a ramp lesion via a trans-notch view and evidence of menisco-capsular injury was recorded. Other concomitant injuries to the knee were also noted. Incidence of meniscal ramp lesions, delay before surgery, and anterior-posterior stability was analyzed. All patients underwent bilateral KT-2000 evaluation.

RESULTS

One hundred and three consecutive ACL injured patients with a mean age of 24 years were included in this study. In total, a ramp lesion was found in 10 knees (9.7%) via a trans-notch view. None of these lesions could be identified by the standard view from the anterolateral portal. Other medial meniscal lesions were found in 26 knees (25.2%) by standard arthroscopic viewing. The ramp lesion group had significantly longer delay before surgery with a median of 191 days (p < 0.01) as well as a larger side-to-side difference of KT-2000 measurement (7.3 ± 1.8 mm; p < 0.01), compared with the intact medial meniscus group (53 days and 5.5 ± 1.5 mm, respectively).

CONCLUSION

Ramp lesions that were identified using a trans-notch view were not visualized with standard arthroscopic views. Increased anterior tibial translation and longer delay before surgery were seen in knees with ramp lesions. Careful inspection of the posteromedial menisco-capsular region is required as hidden menisco-capsular lesions may occur which may result in residual knee instability.

LEVEL OF EVIDENCE

Level II.

Surgical treatment of complex meniscus tear and disease: state of the art

The meniscus is important for load distribution, shock absorption and stability of the knee joint. Meniscus injury or meniscectomy results in decreased function of the meniscus and increased risk of knee osteoarthritis. To preserve the meniscal functions, meniscal repair should be considered as the first option for meniscus injury. Although reoperation rates are higher after meniscal repair compared with arthroscopic partial meniscectomy, long-term follow-up of meniscal repair demonstrated better clinical outcomes and less severe degenerative changes of osteoarthritis compared with partial meniscectomy. In the past, the indication of a meniscal repair was limited both because of technical reasons and due to the localised vascularity of the meniscus. Meanwhile, it spreads today as the development of the concept to preserve the meniscus and the improvement of meniscal repair techniques. Longitudinal vertical tears in the peripheral third are considered the 'gold standard' indication in terms of meniscus healing. Techniques for meniscal repair include 'inside-out', 'outside-in' and 'all-inside' strategies. Surgical decision-making depends on the type, size and location of the meniscus injury. Meniscal root tears substantially affect meniscal hoop function and accelerate cartilage degeneration; therefore, meniscus root repair is necessary to prevent the progression of osteoarthritis change. For symptomatic meniscus defects after meniscectomy, transplantation of allograft or collagen meniscus implant may be indicated, and acceptable clinical results have been obtained. Recently, meniscus extrusion has attracted attention due to increased interest in early osteoarthritis. The centralisation techniques have been proposed to reduce the meniscus extrusion by suturing the meniscus-capsule complex to the edge of the tibial plateau. Long-term clinical outcomes of this procedure may change the strategy of treating meniscus extrusion. When malalignment of the lower leg is accompanied with meniscus pathologies, knee osteotomies are a reasonable option to protect the repaired meniscus by unloading the pathological compartment. Advancements in biological augmentation such as bone marrow stimulation, fibrin clot, platelet-rich plasma, stem cell therapy and scaffolds have also expanded the indications for meniscus surgery. In summary, improved repair techniques and biological augmentation have made meniscus repair more appealing to treat that had previously been considered irreparable. However, further research would be necessary to validate the efficacy of these specialised technique.

Knee laxity in anterolateral complex injuries versus medial meniscus posterior horn injuries in anterior cruciate ligament injured knees: A cadaveric study

INTRODUCTION

There is considerable debate regarding the function of anterolateral knee structures, including the anterolateral ligament (ALL) and anterolateral capsule, as knee stabilizers in anterior cruciate ligament (ACL) injured knees. Medial meniscus posterior horn (MMPH) injuries have also been associated with increased knee laxity in ACL injured knees. The purpose of this cadaveric biomechanical study was to compare the effects of the anterolateral complex (ALC) injury and meniscectomy of MMPH on knee laxity in ACL injured knees.

HYPOTHESIS

ALC injury would have a greater effect on internal rotational laxity in ACL-injured knee than meniscectomy of MMPH.

MATERIAL AND METHODS

Matched-pair 10 fresh-frozen cadaveric knees underwent biomechanical evaluation of knee laxity. After testing the intact knee and ACL sectioned knee (ACL-) in matched-pair 10 fresh-frozen cadaveric knees, two groups were established: an ALC sectioning (ACL-/ALC-) group (n=5) and a MMPH meniscectomy (ACL-/MMPH-) group (n=5). Knee laxity was measured in terms of internal-external rotation, anterior-posterior translation, and varus-valgus angulation for each condition at knee flexion angles of 0°, 30°, 60° and 90°.

RESULTS

After the additional sectioning of the ALC (ACL-/ALC-), the mean internal rotation at 0°, 30°, 60° and 90° of knee flexion showed the greater internal rotation laxity compared than intact knee (p=0.020, 0.011, 0.005 and<0.001). It also significantly increased anterior translation from ACL- at 30° and 60° (p=0.011 and 0.005). In contrast, additional meniscectomy of the MMPH (ACL-/MMPH-) significantly increased external rotation laxity compared to intact knee (p=0.021, 0.018 and 0.024) and ACL- (p=0.037, 0.011 and 0.025) at 30°, 60° and 90°. ACL-/MMPH- also resulted in significantly increased anterior translation from ACL- at 30°, 60° and 90° (p=0.004, 0.008 and 0.002).

DISCUSSION

In conclusion, the anterolateral complex, which include the ALL and anterolateral capsule, may play an important role in stabilizing the knee against internal rotation and anterior translation, while the MMPH may contribute to resisting external rotation and anterior translation stability in ACL-injured knee.

LEVEL OF EVIDENCE

II, controlled laboratory study.

The role of anterolateral augmentation in primary ACL reconstruction

The anterolateral soft tissue envelope of the knee has long been recognised as a key stabilising structure. Once the mainstay of operative management of anterior cruciate ligament (ACL) rupture, interest in the area fell away with the advent of intraarticular arthroscopic reconstruction. Renewed interest in these structures together with cadaveric data evidencing the potential for restoration of near normal knee biomechanics following ACL and anterolateral soft tissue reconstruction has driven current concepts and development of operative techniques. Options for current anterolateral augmentation techniques in primary ACL reconstruction plus patient selection considerations are reviewed, together with an outlook at future research key to development of this area.

Meniscus Repair Does Not Result in an Inferior Short-term Outcome Compared With Meniscus Resection: An Analysis of 5,378 Patients With Primary Anterior Cruciate Ligament Reconstruction

PURPOSE

To compare the preoperative and 1- and 2-year postoperative Knee Injury and Osteoarthritis Outcome Score (KOOS) subscale scores between isolated anterior cruciate ligament reconstruction (ACLR) and ACLR with additional medial meniscus (MM) and/or lateral meniscus (LM) resection or repair.

METHODS

A total of 5,378 patients who underwent primary ACLR, with no associated ligament injuries, at our institution from January 2005 to December 2015 were included. The KOOS subscale scores were used to evaluate patients preoperatively and at 1- and 2-year postoperative follow-up assessments. Patients who underwent isolated ACLR and those who underwent ACLR with additional MM resection, MM repair, LM resection, LM repair, MM plus LM resection, or MM plus LM repair were compared by use of an analysis of covariance, with age, sex, graft, and cartilage injury as covariates.

RESULTS

Postoperatively, at both 1- and 2-year follow-up assessments, no significant differences were found between the groups for any of the 5 KOOS subscales. Preoperatively, a significant difference between the groups was found for the KOOS Symptoms (P < .001), Pain (P < .001), Activities of Daily Living (ADL) (P < .001), and Sport and Recreation (Sport/Rec) (P = .01) subscale scores. The lowest scores were found for the group undergoing ACLR and MM plus LM repair (Symptoms, 70.1 ± 17.3; Pain, 71.4 ± 18.5; ADL, 80.6 ± 20.5; and Sport/Rec, 35.7 ± 28.1), whereas the mean scores for the other groups ranged from 71.2 ± 18.7 to 76.5 ± 17.1 for Symptoms, from 76.1 ± 17.0 to 80.1 ± 15.5 for Pain, from 84.5 ± 16.8 to 88.1 ± 14.2 for ADL, and from 44.2 ± 28.3 to 49.1 ± 28.5 for Sport/Rec.

CONCLUSIONS

Patients undergoing isolated ACLR and those undergoing ACLR with additional MM and/or LM resection or repair obtained equivalent results for each of the KOOS subscales at the 1- and 2-year postoperative follow-up assessments. Differences between the groups were only detectable preoperatively, with patients undergoing ACLR and MM plus LM repair showing the lowest scores for the KOOS Symptoms, Pain, ADL, and Sport/Rec subscales.

LEVEL OF EVIDENCE

Level III, retrospective comparative therapeutic trial.

Physical prognostic factors predicting outcome following anterior cruciate ligament reconstruction: protocol for a systematic review

INTRODUCTION

Injuries of the anterior cruciate ligament (ACL) are a common musculoskeletal complication and can cause significant reduction in patient function and quality of life. Many undergo ACL reconstruction, with high-quality rehabilitation key to successful outcome. Knowledge of physical prognostic factors, such as quadriceps strength, is crucial to inform rehabilitation and has important implications for outcome following ACL reconstruction. However, these factors predicting outcome are poorly defined. Therefore, the aim of this systematic review is to establish physical prognostic factors predictive of outcome in adults following ACL reconstruction. Outcome will be subdivided into two groups of outcome measures, patient-reported and performance-based. Physical prognostic factors of interest will reflect a range of domains and may be modifiable/non-modifiable. Results will help decide most appropriate management and assist in planning and tailoring preoperative and postoperative rehabilitation.

METHODS AND ANALYSIS

This systematic review protocol is reported according to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols. MEDLINE, CINAHL and EMBASE databases, key journals and grey literature will be searched from inception to July 2019. Prospective cohort studies including participants aged ≥16 years who have undergone ACL reconstruction will be included, with articles focusing on multi-ligament reconstructions and ACL repair surgery, or not published in English excluded. Two independent reviewers will conduct searches, assess study eligibility, extract data, assess risk of bias (Quality in Prognostic Studies tool) and quantify overall quality of evidence (modified Grading of Recommendations, Assessment, Development and Evaluation guidelines). If possible, a meta-analysis will be conducted, otherwise a narrative synthesis will ensue focusing on prognostic factors, risk of bias of included studies and strength of association with outcomes.

ETHICS AND DISSEMINATION

Findings will be published in a peer-reviewed journal, presented at conferences and locally to physiotherapy departments. Ethical approval is not required for this systematic review.

PROSPERO REGISTRATION NUMBER

CRD42019127732.

Knee laxity in anterolateral complex injuries versus lateral meniscus posterior horn injuries in anterior cruciate ligament deficient knees: A cadaveric study

BACKGROUND

In the anterior cruciate ligament (ACL) injured knee, additional injury of the anterolateral ligament (ALL) and capsule may increase the pathologic laxity. The purpose of this study was to compare the effects of the anterolateral complex (ALC) injury in ACL injured knee with the effects of lateral meniscus posterior horn (LMPH) meniscectomy.

METHODS

Ten fresh-frozen cadaveric knees were used. After testing the (1) intact knees and (2) ACL sectioned knees (ACL-), two groups were established: an (3) ALC sectioning group (n = 5), which underwent additional ALC sectioning (ACL-/ALC-) after ACL sectioning, and a separate (3) LMPH meniscectomy group (n = 5) that underwent LMPH meniscectomy (ACL-/LMPH-) after ACL sectioning. Knee laxity was measured in terms of internal-external rotation, anterior-posterior translation, and varus-valgus angulation for each condition at knee flexion angles of 0°, 30°, 60° and 90°.

RESULTS

After additional sectioning of the ALC (ACL-/ALC-), the mean internal rotation at 0, 30, 60 and 90° of knee flexion was 11.9 ± 1.3°, 18.1 ± 1.6°, 18.3 ± 1.8°, and 17.8 ± 2.4°, respectively, showing significant internal rotation laxity when compared to the intact knee (P = .031, .020, .001 and .033). Anterior translation also significantly increased compared to the ACL- knee at 30° (12.7 ± 1.4 to 16.8 ± 1.7 mm: P = .039). In contrast, additional meniscectomy of the LMPH (ACL-/LMPH-) significantly increased valgus laxity compared to the intact knee at 30, 60 and 90° (P = .021, .018 and .024).

CONCLUSION

These findings suggest that the anterolateral complex, which include the ALL and anterolateral capsule, may play an important role in stabilizing the knee against internal rotation and anterior translation.

Ramp lesions are frequently missed in ACL-deficient knees and should be repaired in case of instability

PURPOSE

The aim of the current study was (1) to provide an overview of common definitions and classification systems of ramp lesions (RL) and (2) to systematically review the available literature with regard to the diagnosis and treatment of RLs in anterior cruciate ligament (ACL)-deficient knees.

METHODS

Following the PRISMA guidelines, MEDLINE and Scopus were searched for articles (1) reporting on acute or chronic ACL injuries, (2) with concomitant medial meniscus injury, (3) located at the posterior meniscocapsular attachment site (and red-red zone). Ex vivo studies, reviews and technical notes were excluded.

RESULTS

Twenty-seven studies were included based on the criteria mentioned above. RLs are common in ACL-deficient knees with a prevalence ranging from 9 to 24%. RLs should especially be suspected in younger patients, patients with an increased meniscal slope and in patients with prolonged time from injury to surgery. The sensitivity of MRI for the detection of RLs ranges from 48 to 86% at a specificity of 79-99%. For arthroscopy, RLs are easily missed through standard anterior portals (sensitivity 0-38%). RL repair leads to a significant improvement of subjective knee scores, regardless of the specific fixation technique. For stable RLs, the literature suggests equivalent postoperative stability for trephination and abrasion compared to surgical RL repair.

CONCLUSION

Ramp lesions are frequently missed in ACL-deficient knees on standard arthroscopy with anterior portals only. If a RL is suspected, exploration via an additional posteromedial portal is indicated. In case of instability, RL repair should be performed.

LEVEL OF EVIDENCE

IV.

Anterior cruciate ligament reconstruction with concomitant meniscal surgery: a systematic review and meta-analysis of outcomes

PURPOSE

The aim of this review was to compare the clinical outcomes of anterior cruciate ligament reconstruction (ACLR) with either meniscal repair or meniscectomy for concomitant meniscal injury. The primary hypothesis was that short-term clinical outcomes (≤ 2-year follow-up) for ACLR concomitant with either meniscal repair or resection would be similar. The secondary hypothesis was that ACLR with meniscal repair would result in better longer term outcomes compared with meniscal resection.

METHODS

The authors searched two online databases (EMBASE and MEDLINE) from inception until March 2018 for the literature on ACLR and concurrent meniscal surgery. Two reviewers systematically screened studies in duplicate, independently, and based on a priori criteria. Quality assessment was also performed in duplicate. The Knee injury and Osteoarthritis Outcome Score (KOOS) sub-scale scores at 2 years post-operatively were combined in a meta-analysis of proportions using a random-effects model.

RESULTS

Of 2566 initial studies, 25 studies satisfied full-text inclusion criteria. Mean follow-up was 2.09 years, with a total sample of 37,087 subjects including controls. The meta-analysis demonstrated equivocal results at 2 years, except for KOOS symptom scores which favoured meniscal resection over repair. Mean KT-1000 side-to-side difference (SSD) scores were 1.51 ± 0.60 mm for meniscal repair, 1.96 ± 0.36 mm for meniscal resection, and 1.58 ± 0.20 for control patients (isolated ACLR). Medial meniscal repair showed decreased anterior knee joint laxity compared to medial meniscal resection (P < 0.001). Patients with meniscal repair had higher rates of re-operation (13.3% vs 0.8% for meniscal resection, P < 0.001).

CONCLUSION

Patients with ACLR combined with meniscal resection demonstrate better symptoms at 2-year follow-up compared to patients with ACLR combined with meniscal repair. ACLR combined with meniscal repair results in decreased anterior knee joint laxity with evidence of improved patient-reported outcomes in the long term, but also higher re-operation rates.

LEVEL OF EVIDENCE

III.

Lateral Meniscal Allograft Transplantation With Bone Block and Suture-Only Techniques Partially Restores Knee Kinematics and Forces

BACKGROUND

The ability of lateral meniscal allograft transplantation (MAT) to improve knee stability and the meniscal load-bearing function in patients after meniscectomy is critical for surgical success.

PURPOSE

To compare the effects of 2 lateral MAT fixation techniques-bone block and suture only-on knee kinematics and forces.

STUDY DESIGN

Controlled laboratory study.

METHODS

With a robotic testing system, loads were applied during flexion on 10 fresh-frozen cadaveric knees: 134-N anterior tibial load + 200-N axial compression, 5-N·m internal tibial + 5-N·m valgus torques, and 5-N·m external tibial + 5-N·m valgus torques. Kinematic data were recorded for 4 knee states: intact, total lateral meniscectomy, lateral MAT bone block, and lateral MAT suture-only fixation. In situ force in the anterior cruciate ligament and resultant forces in the lateral meniscus and in the meniscal allograft were quantified via the principle of superposition. A repeated measures analysis of variance was used to analyze variations in kinematics and forces at 0°, 30°, 60°, and 90° of knee flexion. Significance was set at P < .05.

RESULTS

When anterior loads were applied, a decrease in medial translation of the tibia that was increased after total lateral meniscectomy was observed at 30°, 60°, and 90° of knee flexion for both the lateral MAT bone block (54.2%, 48.0%, and 50.0%) and the MAT suture-only (50.0%, 40.0%, and 34.6%) fixation techniques (P < .05). Yet, most of the increases in knee kinematics after lateral meniscectomy were not significantly reduced by either lateral MAT technique (P > .05 for each MAT technique vs the total lateral meniscectomy state). Resultant forces in the meniscal allograft were 50% to 60% of the resultant forces in the intact lateral meniscus in response to all loading conditions at all flexion angles (P < .05). Overall, no significant differences between lateral MAT techniques were observed regarding kinematics and forces (P > .05).

CONCLUSION

Lateral MAT partially restored medial translation of the tibia, and the resultant forces in the meniscal allograft were only 50% to 60% of the intact lateral meniscus forces in the cadaver model. In the majority of testing conditions, no significant changes of the in situ force in the anterior cruciate ligament were observed. Surgeons should consider the potential benefits of lateral MAT when deciding the appropriate treatment for symptomatic patients after lateral meniscectomies. Both lateral MAT techniques functioned similarly.

CLINICAL RELEVANCE

The load-bearing function of the meniscal allograft observed in this study may be beneficial in ameliorating the short- and long-term disability associated with lateral meniscal deficiency.

Partial meniscectomy adversely affects return-to-sport outcome after anatomical double-bundle anterior cruciate ligament reconstruction

PURPOSE

The purposes of this study were to determine whether the partial meniscectomy combined with ACL reconstruction affect the postoperative return-to-sport and to identify if partial meniscectomy has an influence on the graft failure following an anatomical double-bundle ACL reconstruction case.

METHODS

A retrospective cohort study including 426 primary double bundle ACL reconstruction cases. There were 206 males and 220 females, median age of 28.4 years, median BMI of 23.0, median preinjury Tegner score of 7.0 and median follow-up period after surgery of 24.0 months. Patients with less than 12 months of follow-up, revision surgery, multi-ligaments injury, previous contralateral knee ligaments injury and postoperative infection cases were excluded. Furthermore, patients who had meniscal repair were excluded in order to compare the outcomes between patients who had intact menisci and those who underwent partial meniscectomy. There were 227 patients with intact menisci (group A) and 199 patients with partial meniscectomy (group B). The median age was younger and the preoperative Tegner score was higher in group A. The patients in group B were subcategorized as the site of partial meniscectomy, including medial (group C), lateral (group D) and bicompartmental (group E) meniscectomy. There were 74, 94, and 31 patients in group C, D, and E, respectively. Return-to-sport (running and sport phase) and graft failure were included in our primary outcomes, and functional outcome as Lysholm knee scores was included in secondary outcome.

RESULTS

The rate of return to running phase and sport phase were 91% (387/426) and 76% (303/399), the mean time taken to return to running and sport phase were 5.7 months and 11.1 months, respectively. There was significant difference in the returning to sport phase between group A and B (p = 0.01), and between group A and D/E subgroups (p = 0.007). There were fourteen graft failures (3.5%) in total. In addition, 9 and 5 graft failures in group A and B, respectively. Of the 5 graft failures in group B, 2 and 3 graft failures in group C and D, respectively. There was no significant difference of the graft failure ratio among the groups.

CONCLUSION

Our study demonstrates that partial meniscectomy has an adverse effect on the return to sport phase following the anatomical double-bundle ACL reconstruction. Therefore, greater postoperative care would be needed to return to sport with partial meniscectomy in ACL reconstruction cases. On the contrary, partial meniscectomy is not considered to be the risk factor for graft failure at short-term follow-up.

LEVEL OF EVIDENCE

Case-control study, Level III.

The Ratio of Tibial Slope and Meniscal Bone Angle for the Prediction of ACL Reconstruction Failure Risk

Background  A growing body of research is indicating that the tibial slope and the geometry of the tibiofemoral meniscal-cartilage interface may affect the risk of anterior cruciate ligament reconstruction (ACLR) failure. Increased lateral tibial posterior slope (LTPS) and reduced meniscal bone angle (MBA) are associated with increased risk of anterior cruciate ligament (ACL) injury. The significance of a LTPS-MBA ratio regarding the prediction of ACL failure risk remains unknown. As LTPS and MBA may eventually potentiate or neutralize each other, it is expected that a low LTPS-MBA ratio is associated with high chance of ACL graft survival while a high LTPS-MBA ratio is associated with high risk of ACL failure. Material and Methods  Out of 1,487 consecutive patients who underwent hamstring ACLR between August 2000 and May 2013, 54 ACLR failures with intact lateral menisci were included in this study and matched one-to-one with 54 control participants by age, sex, graft, surgical technique, and graft fixation method. Control participants had undergone ACLR without signs of lateral meniscal injury, graft failure, or insufficiency. MBA and LTPS were assessed on magnetic resonance imaging. Logistic regression was used to identify LTPS/MBA key cut-off ratios. Results  In this cohort, a LTPS-MBA ratio under 0.27 was associated with a 28% risk of ACLR failure (36% of patients), while a ratio exceeding 0.42 was associated with an 82% risk of ACLR failure (31% of patients). The odds of ACL failure increased by 22.3% per reduction of 1 degree in MBA (odds ratio [OR], 1.22; 95% limits, 1.1-1.34). No significant association was found between LTPS and the risk of ACL graft failure in transtibial ACLR, while the odds of ACL failure increased by 34.9% per degree of increasing LTPS in transportal ACLR (OR, 1.34; 95% limits, 1.01-1.79). No significant correlation was found between MBA and LTPS ( p  = 0.5). Conclusion  Reduced MBA was associated with significantly increased risk of ACL graft failure. A ratio of LTPS and MBA was found to be useful for the prediction of ACLR failure risk and may preoperatively help to identify patients at high risk of ACLR failure. This may have implications for patient counseling and the indication of additional extra-articular stabilizing procedures.

Meniscal repair results in inferior short-term outcomes compared with meniscal resection: a cohort study of 6398 patients with primary anterior cruciate ligament reconstruction

PURPOSE

To compare patient reported outcome measures (PROMs) during the first postoperative year between isolated anterior cruciate ligament (ACL) reconstruction and ACL reconstruction with concomitant meniscal intervention.

METHODS

Patients who underwent primary ACL reconstruction at Capio Artro Clinic, Stockholm, Sweden, between 1st Jan 2001 and 31st Dec 2014 without concomitant injuries others than meniscal and/or cartilage lesions were included. Five groups of meniscal treatment simultaneously to ACL reconstruction were established; medial meniscal (MM) resection, MM repair, lateral meniscal (LM) resection, LM repair, and MM + LM resection. Patients treated with isolated ACL reconstruction formed a separate group. Preoperative, 6-month and 1-year Knee Injury and Osteoarthritis Outcome Score (KOOS), and Lysholm knee score and Tegner Activity scale were collected. Differences in the change over time were analyzed with an ANOVA for repeated measurements with age at surgery, gender, and cartilage injury as covariates. A univariate ANOVA was applied to analyze PROMs between groups at the final follow-up.

RESULTS

A total of 6398 patients were included (56.8% males, mean age 28.5 ± 10.2 years). The KOOS improved across all subscales for all treatment groups. The mean change over time differed significantly between groups for the subscales symptoms (p = 0.017) and activities in daily living (ADL) (p < 0.001). Symptoms was least improved in the MM repair group, while the MM + LM resection group showed the largest improvement. For the ADL subscale, the isolated ACL reconstruction group showed the least improvement and the MM + LM resection group showed the major improvement. At 1-year follow-up, a significant difference between the groups was found for the subscale symptoms (p = 0.019), where the MM repair group reported the lowest score [mean 78.4 (95% CI 76.3-80.5)]. No significant differences were found between groups in change of the Lysholm score over time; however, at 6 months, the difference between groups was significant (p = 0.006) with the meniscal repair groups reporting the lowest scores.

CONCLUSION

Patients with concomitant meniscal resection are able to reach the same subjective knee function as isolated ACL reconstructions as early as 6 months postoperatively. However, patients with meniscal repair may have slightly worse subjective knee function at both 6- and 12-month follow-up. These findings could help clinicians to set realistic short-term expectations for patients undergoing ACL reconstruction with simultaneous meniscal intervention.

LEVEL OF EVIDENCE

3.

Risk Factors for Abnormal Anteroposterior Knee Laxity After Primary Anterior Cruciate Ligament Reconstruction

PURPOSE

To identify preoperative and intraoperative factors associated with abnormal anterior knee laxity after primary anterior cruciate ligament (ACL) reconstruction.

METHODS

A total of 5,462 patients who underwent primary ACL reconstruction at our institution from January 2000 to October 2015, with no associated ligament injuries, were included. Demographic data, information regarding graft used, concomitant meniscal surgery, and instrumented laxity were reviewed. The KT-1000 arthrometer, with an anterior tibial load of 134 N, was used to evaluate knee laxity preoperatively and at 6-month follow-up. Patients were considered to have abnormal anterior knee laxity if the postoperative side-to-side difference was greater than 5 mm (International Knee Documentation Committee laxity grade C or D). A logistic regression analysis was used to evaluate whether patient age, gender, preoperative knee laxity, graft type, and presence of medial or lateral meniscus resection or suture were risk factors for abnormal knee laxity.

RESULTS

The risk of having abnormal anterior knee laxity was significantly related to younger age (<30 years) (odds ratio [OR] 1.44; 95% confidence interval [CI], 1.07-1.95; P = .016), preoperative side-to-side difference greater than 5 mm (OR, 6.57; 95% CI, 4.94-8.73; P < .001), hamstring tendon graft (OR, 1.83; 95% CI, 1.08-3.11; P = .025), and medial meniscus resection (OR, 2.22; 95% CI, 1.61-3.07; P < .001). Female gender (OR, 0.96; 95% CI, 0.72-1.28; P = .80), medial meniscus suture (OR, 0.82; 95% CI 0.42-1.62; P = .58), lateral meniscus resection (OR, 0.73; 95% CI 0.49-1.10; P = .13), and lateral meniscus suture (OR, 0.99; 95% CI, 0.46-2.11; P = .98) were not associated with increased risk of abnormal knee laxity.

CONCLUSIONS

Age less than 30 years, preoperative side-to-side difference greater than 5 mm, hamstring tendon graft, and medial meniscus resection are associated with increased risk of having abnormal anterior knee laxity 6 months after primary ACL reconstruction.

LEVEL OF EVIDENCE

Level III, retrospective comparative trial.

Anterolateral Ligament Reconstruction Protects the Repaired Medial Meniscus: A Comparative Study of 383 Anterior Cruciate Ligament Reconstructions From the SANTI Study Group With a Minimum Follow-up of 2 Years

BACKGROUND

The prevalence of osteoarthritis after successful meniscal repair is significantly less than that after failed meniscal repair.

PURPOSE

To determine whether the addition of anterolateral ligament reconstruction (ALLR) confers a protective effect on medial meniscal repair performed at the time of anterior cruciate ligament reconstruction (ACLR).

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Retrospective analysis of prospectively collected data was performed to include all patients who had undergone primary ACLR with concomitant posterior horn medial meniscal repair through a posteromedial portal between January 2013 and August 2015. ACLR autograft choice was bone-patellar tendon-bone, hamstring tendons (or quadrupled hamstring tendons), or quadrupled semitendinosus tendon graft with or without ALLR. At the end of the study period, all patients were contacted to determine if they had undergone reoperation. A Kaplan-Meier survival curve was plotted, and a Cox proportional hazards regression model was used to perform multivariate analysis.

RESULTS

A total of 383 patients (mean ± SD age, 27.4 ± 9.2 years) were included with a mean follow-up of 37.4 months (range, 24-54.9 months): 194 patients underwent an isolated ACLR, and 189 underwent a combined ACLR + ALLR. At final follow-up, there was no significant difference between groups in postoperative side-to-side laxity (isolated ACLR group, 0.9 ± 0.9 mm [min to max, -1 to 3]; ACLR + ALLR group, 0.8 ± 1.0 mm [min to max, -2 to 3]; P = .2120) or Lysholm score (isolated ACLR group, 93.0 [95% CI, 91.3-94.7]; ACLR + ALLR group, 93.7 [95% CI, 92.3-95.1]; P = .556). Forty-three patients (11.2%) underwent reoperation for failure of the medial meniscal repair or a new tear. The survival rates of meniscal repair at 36 months were 91.2% (95% CI, 85.4%-94.8) in the ACLR + ALLR group and 83.8% (95% CI, 77.1%-88.7%; P = .033) in the ACLR group. The probability of failure of medial meniscal repair was >2 times lower in patients with ACLR + ALLR as compared with patients with isolated ACLR (hazard ratio, 0.443; 95% CI, 0.218-0.866). No other prognosticators of meniscal repair failure were identified.

CONCLUSION

Combined ACLR and ALLR is associated with a significantly lower rate of failure of medial meniscal repairs when compared with those performed at the time of isolated ACLR.

Lateral meniscus posterior root tear contributes to anterolateral rotational instability and meniscus extrusion in anterior cruciate ligament-injured patients

PURPOSE

The purposes of this study were to investigate (1) meniscus status and clinical findings in anterior cruciate ligament (ACL)-injured patients to clarify associations between the meniscus posterior root tear (PRT) and knee instability, and (2) magnetic resonance imaging (MRI) findings of the PRT to clarify sensitivity and specificity of MRI and prevalence of meniscus extrusion.

METHODS

Three hundred and seventeen patients with primary ACL reconstruction were included. PRTs for both medial and lateral sides were confirmed by reviewing surgical records. Preoperative MRI was reviewed to evaluate sensitivity and specificity of the PRT and meniscus extrusion width (MEW). Clinical information regarding the number of giving-way episodes, preoperative KT-1000 measurements and preoperative pivot shift was also assessed.

RESULTS

Thirty-nine patients had a lateral meniscus (LM) PRT, whereas only four patients had a medial meniscus PRT. One hundred and seventeen patients had no meniscus tear (control). Twenty-eight patients (71.8%) showed positive signs of the LMPRT based on at least one view of MR images, with the coronal view showing the highest sensitivity. MEW in the LMPRT group was significantly larger than that in the control group. The preoperative pivot shift test grade in the LMPRT group was significantly greater than that in the control group. There were no significant differences in other parameters.

CONCLUSIONS

In ACL-injured patients, the LMPRT was associated with ALRI as well as with meniscus extrusion. The coronal view of MRI was useful in identifying the LMPRT, although its sensitivity was not high. Therefore, surgeons should prepare to repair PRTs at the time of ACL reconstruction regardless of MRI findings, and they should make every effort to repair the LMPRT.

LEVEL OF EVIDENCE

III.

Concomitant meniscal injury in anterior cruciate ligament reconstruction does not lead to poorer short-term post-operative outcomes

PURPOSE

The main objective was to compare post-operative outcomes in patients undergoing anterior cruciate ligament (ACL) reconstruction both with and without concomitant meniscus injury at a mean follow-up of 3.5 years. The secondary objective was to study the effect of different meniscal injury sites and treatment modalities on post-operative outcomes (PROS).

METHODS

This is a retrospective analysis of a prospectively maintained database of patients undergoing ACL reconstruction at our tertiary institution between 2009 and 2012. Age, sex, graft type, graft fixation modality, location of meniscal tear and treatment (meniscal repair or meniscectomy) were recorded in the database. PROS used included the Tegner activity scale and the Lysholm score.

RESULTS

There were no significant differences between patients with or without meniscal injury in terms of age, BMI or preoperative PROS. There was no significant difference in the post-operative outcome scores between patients with or without meniscal injury at a mean follow-up of 3.5 years. Regardless of the location of meniscal injury, the post-operative scores improved as compared to preoperative scores.

CONCLUSION

Concomitant meniscal injury in cases of ACL reconstruction is not associated with poorer short-term post-operative PROS (mean follow-up time: 3.5 years). These findings may influence management decisions and help in preoperative counselling.

LEVEL OF EVIDENCE

IV.

Ramp lesions in ACL deficient knees in children and adolescent population: a high prevalence confirmed in intercondylar and posteromedial exploration

PURPOSE

Ramp lesions are common in ACL deficient knees. Their diagnosis is difficult and, therefore, they may be underestimated. So far, no study analyzed their prevalence in a pediatric population. The diagnosis of these Ramp lesions is of major clinical relevance because of a frequent misestimating and technic difficulties. Ramp lesions might be associated with residual knee pain and instability after ACL reconstruction. The aim of this study was to evaluate the prevalence of ramp lesions explored through a systematic intercondylar and posteromedial arthroscopic approach during an ACL reconstruction in a pediatric and adolescent population.

METHODS

Children and adolescents who underwent an ACL reconstruction were screened prospectively between October 2014 and 2016. The presence or absence of a ramp lesion was evaluated after each of three arthroscopic steps: (1) an anterior approach, (2) an intercondylar inspection, and (3) a posteromedial approach. Ramp lesions were screened at each step and their prevalence was evaluated. Furthermore, their presence was correlated to age, weight, size, sex, and state of the physis (open or closed). Finally, the meniscal status on MRI and arthroscopic findings were compared.

RESULTS

Fifty-six patients were analyzed. The median age was 14.0 ± 1.3 years (12-17). The median interval between injury and surgery was 11.5 months (1-108). During step 1 (anterior approach), only 1 ramp lesion (2%) was diagnosed. 13 (23%) ramp lesions were found after inspection through the intercondylar notch. No additional lesions were found with a direct view through the posteromedial approach. No correlation between ramp lesions and side, sex, weight, size, or state of physis was found. 10 ramp lesions out of 13 could not be diagnosed on MRI.

CONCLUSIONS

The prevalence of ACL-associated ramp lesions in children and adolescents is similar to adult populations. A systematic inspection through the intercondylar notch is recommended during ACL reconstruction to make a precise diagnosis. The posteromedial approach is essentially useful for meniscal repair LEVEL OF EVIDENCE: Testing, previously developed diagnostic criteria in a consecutive series of patients and a universally applied "gold" standard, Level I.

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.

Medial Meniscus Resection Increases and Medial Meniscus Repair Preserves Anterior Knee Laxity: A Cohort Study of 4497 Patients With Primary Anterior Cruciate Ligament Reconstruction

BACKGROUND

There are still controversies regarding the effects on knee laxity of additional meniscus resection or repair in the setting of anterior cruciate ligament reconstruction (ACLR). Hypothesis/Purpose: The purpose was to determine the effects on knee laxity of resection or repair of medial meniscus (MM) or lateral meniscus (LM) injuries in the ACLR knee. The hypothesis was that patients with an additional meniscus resection would have significantly increased postoperative knee laxity versus that of an isolated ACLR, whereas patients with meniscus repair would have laxity comparable to that of an isolated ACLR.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The KT-1000 arthrometer, with an anterior tibial load of 134 N, was used to evaluate knee laxity preoperatively and at 6-month postoperative follow-up for a total of 4497 patients with primary hamstring tendon ACLR. Patients with isolated ACLR or ACLR with additional MM resection, MM repair, LM resection, LM repair, or MM plus LM resection were compared, with the isolated ACLR group as a control.

RESULTS

All patients showed a significant reduction of knee laxity preoperatively (3.6 ± 3.1 mm) to postoperatively (1.9 ± 2.2 mm) ( P < 0.0001). Patients who had an ACLR with either an MM resection (2.2 ± 2.55 mm) or MM + LM resection (2.35 ± 2.30 mm) showed significant increased postoperative knee laxity versus isolated ACLR (1.74 mm ± 2.11 mm) ( P < 0.05), whereas patients with MM repair (1.69 ± 2.37 mm) did not show significantly different knee laxity when compared with the control group ( P > 0.05). LM resection or repair did not significantly affect knee laxity. Significantly more surgical failures, defined as side-to-side difference >5 mm, were found in the ACLR + MM resection group and the ACLR + MM + LM resection group.

CONCLUSION

In ACLR, additional MM resection increased whereas MM repair preserved knee laxity in comparison with the ACLR knee with intact menisci. Neither LM resection or LM repair showed a significant effect on knee laxity. Surgeons should make every effort to repair the meniscus whenever possible to avoid the residual postoperative laxity present in the meniscus-deficient knee.

Underappreciated Factors to Consider in Revision Anterior Cruciate Ligament Reconstruction: A Current Concepts Review

Primary anterior cruciate ligament (ACL) reconstructions (ACLRs) are being performed with increasing frequency. While many of these will have successful outcomes, failures will occur in a subset of patients who will require revision ACLRs. As such, the number of revision procedures will continue to rise as well. While many reviews have focused on factors that commonly contribute to failure of primary ACLR, including graft choice, patient factors, early return to sport, and technical errors, this review focused on several factors that have received less attention in the literature. These include posterior tibial slope, varus malalignment, injury to the anterolateral ligament, and meniscal injury or deficiency. This review also appraised several emerging techniques that may be useful in the context of revision ACL surgery. While outcomes of revision ACLR are generally inferior to those of primary procedures, identifying these potentially underappreciated contributing factors preoperatively will allow the surgeon to address them at the time of revision, ideally improving patient outcomes and preventing recurrent ACL failure.

Outcomes After Double-Bundle Anterior Cruciate Ligament Reconstruction

PURPOSE

To identify the risk factors predicting unsatisfactory postoperative clinical outcomes after double-bundle (DB) anterior cruciate ligament (ACL) reconstruction using multivariate logistic regression.

METHODS

Inclusion criteria were consecutive DB ACL reconstructions from January 2006 to September 2012 with a minimum 3-year follow-up. Exclusion criteria included (1) a delay to surgery from initial injury of more than 4 years (210 weeks); (2) contralateral knee pathology; (3) the lack of postoperative 3-dimensional computed tomography; (4) single-bundle ACL reconstruction; (5) revision ACL reconstruction; (6) meniscus allograft transplantation after total or subtotal meniscectomy; (7) multiple ligament surgeries. According to the overall International Knee Documentation Committee (IKDC) rating at the last follow-up, we sorted all enrolled subjects into superior (IKDC grade A or B) and inferior outcome groups (IKDC grade C or D). Multivariate logistic regression was used to analyze risk factors, including age, gender, body mass index, time from injury to surgery, posterior tibial slope, notch width index, cartilage injury, meniscus injury, and femoral and tibial tunnel positions.

RESULTS

In comparison between the superior outcome group (n = 240) and inferior outcome group (n = 50), anterior (adjusted odds ratio [OR]: 0.902, 95% confidence interval [CI]: 0.846-0.962) or distal (adjusted OR: 1.025, 95% CI: 1.006-1.060) femoral anteromedial tunnel position was a significant risk factor for the inferior outcomes. Partial meniscectomy of medial (adjusted OR: 49.002, 95% CI: 7.047-340.717) or lateral (adjusted OR: 14.974, 95% CI: 2.181-102.790) meniscus and delayed time from injury to surgery (adjusted OR: 1.062, 95% CI: 1.023-1.102) were also a significant predictor.

CONCLUSION

Anterior or distal anteromedial femoral tunnel position, partial meniscectomy of medial or lateral meniscus, and prolonged surgical delay of more than 11.5 weeks from injury were significant risk factors for the inferior clinical outcomes after DB ACL reconstruction.

LEVEL OF EVIDENCE

Level III, retrospective therapeutic case series.

Clinical Outcomes After Combined Anterior Cruciate Ligament and Anterolateral Ligament Reconstruction

Background

Graft rupture rate, return to sport and persistent rotational instability remain a concern postoperatively following anterior cruciate ligament (ACL) reconstruction. The anterolateral ligament (ALL) has recently been shown to act as a lateral knee stabilizer that helps improve rotational stability. To improve functional and clinical outcomes, a combined ACL reconstruction with an associated ALL reconstruction has been proposed.

Purpose

The main purpose of this study was to evaluate the clinical outcomes of the combined ACL and ALL reconstruction.

Methods

A literature search in PubMed was performed and papers reporting on clinical outcomes after combined ACL and ALL reconstruction were identified. The inclusion criteria was a minimum 2-year follow-up.

Results

Five studies were included in the review. The overall graft failure rate in patients with ACL and ALL reconstruction was <3% at 2 years minimum after surgery. Comparison analysis in a high-risk population demonstrated that the graft failure rate in combined ACL and ALL reconstruction was 2.5 times lower than with isolated bone-patella tendon-bone graft and 3.1 times lower than with isolated hamstring graft. The medial meniscal repair failure rate was also 2 times lower in the combined ACL and ALL reconstruction group compared with isolated ACL reconstruction. Return to sport and functional outcomes did not show any significant difference between the groups. The rate of reoperations was not increased in patients with combined ACL and ALL reconstruction.

Conclusions

Overall, combined ACL and ALL reconstruction provides promising results that may improve graft rupture rates and meniscal repair failure rates, while maintaining excellent functional outcomes.