Tear Rates of the Ipsilateral ACL Graft and the Contralateral Native ACL Are Similar following ACL Reconstruction

Higher Unilateral Muscle Imbalance at the Contralateral Knee 6 Months after Anterior Cruciate Ligament Reconstruction

There are a considerable number of patients who, after anterior cruciate ligament reconstruction (ACL), suffer from relapses or reduced performance. Data collected from isokinetic dynamometry can provide useful information on the condition of the knee during rehabilitation. Seventy-one young sports patients with ACL reconstruction performed concentric (CON) isokinetic dynamometry (CON/CON 90°/s and CON/CON 240°/s) to assess the muscle strength of the quadriceps (Q) and hamstrings (H) in both knees at 6 months after ACL reconstruction. Limb symmetry index (LSI) and the H/Q ratio were calculated. Comparative statistical tests and multivariate regression were performed. At 90°/s, 57 patients (80.3%) had an LSI below 90% for quadriceps and 28 (60.6%) for hamstring. The number of imbalanced patients according to H/Q ratio was higher in the non-operated knee (n = 56, 78.9%) (p < 0.001). At 240°/s, 49 cases (69.1%) had LSI values above 90% for quadriceps and 37 (52.1%) for hamstrings. Regarding H/Q, imbalanced cases were higher in the non-operated limb (n = 60, 84.5%) (p < 0.001). Strength data at 6 months after ACL reconstruction and post-operative rehabilitation indicated greater unilateral (H/Q) muscle imbalance in the non-operated knee than in the operated knee. Most patients did not achieve the adequate LSI values.

Return to Sports: A Risky Business? A Systematic Review with Meta-Analysis of Risk Factors for Graft Rupture Following ACL Reconstruction

BACKGROUND

The risk of sustaining a graft rupture after anterior cruciate ligament reconstruction (ACLR) is high. Contributing risk factors are, however, still not clearly identified.

OBJECTIVE

The aim of this systematic review was to identify and quantify risk factors for graft rupture after ACLR.

METHODS

A systematic review with meta-analysis (PROSPERO CRD42020140129) based on PRISMA guidelines was performed. MEDLINE, CINAHL and EMBASE were searched from inception to September 2021. Prospective and retrospective studies addressing risk factors for graft rupture after ACLR in males/females of all ages were considered. Meta-analyses using a random effect model (effect measure: odds ratio [OR] with 95% confidence interval [CI]) were performed. The GRADE tool was used to assess evidence quality.

RESULTS

Following full-text screening of 310 relevant papers, 117 were eventually included, incorporating up to 133,000 individuals in each meta-analysis. Higher Tegner activity level (≥ 7 vs < 7) at primary injury (OR 3.91, 95% CI 1.69-9.04), increased tibial slope (degrees) (OR 2.21, 95% CI 1.26-3.86), lower psychological readiness to return to sport (RTS) (OR 2.18, 95% CI 1.32-3.61), early surgery (< 12 vs ≥ 12 months) (OR 1.87, 95% CI 1.58-2.22), RTS (pre-injury level) (OR 1.87, 95% CI 1.21-2.91) and family history of ACL injury (OR 1.76, 95% CI 1.34-2.31) were all associated with increased odds of graft rupture. Higher age (OR 0.47, 95% CI 0.39-0.59), female sex (OR 0.88, 95% CI 0.79-0.98), fewer self-reported knee symptoms pre-reconstruction (OR 0.81, 95% CI 0.69-0.95) and concomitant cartilage injuries (OR 0.70, 95% CI 0.62-0.79) instead decreased the odds. Meta-analysis revealed no association between body mass index, smoking, joint laxity, RTS time, knee kinematics, muscle strength or hop performance and graft rupture.

CONCLUSION

Conspicuous risk factors for graft rupture were mainly sports and hereditary related. Few studies investigated function-related modifiable factors or included sports exposure data.

High Risk of New Knee Injuries in Female Soccer Players After Primary Anterior Cruciate Ligament Reconstruction at 5- to 10-Year Follow-up

BACKGROUND

A new anterior cruciate ligament (ACL) injury after ACL reconstruction is a feared outcome.

PURPOSE

To study the risk of new knee injuries in female soccer players 5 to 10 years after primary unilateral ACL reconstruction and to compare players who returned to soccer with (1) players who did not return and (2) knee-healthy soccer players (controls).

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Demographic, soccer-specific, and surgical data were recorded at baseline for 317 female soccer players (mean ± SD age, 20.1 ± 2.7 years) 1.6 ± 0.7 years after ACL reconstruction and for 119 matched controls (mean age, 19.5 ± 2.5 years). Data on new knee injuries and soccer-playing status were collected 5 to 10 years after ACL reconstruction via a questionnaire.

RESULTS

Among players with ACL reconstruction, 222 (70%) responded at a mean 6.5 ± 1.0 years after primary ACL reconstruction. We compared 3 cohorts: (1) among 163 players with ACL reconstruction who returned to soccer, 68 (42%) sustained 44 reruptures and 29 contralateral ruptures; (2) among 59 players with ACL reconstruction who did not return to soccer, 11 (19%) sustained 9 reruptures and 2 contralateral ruptures; and (3) among 113 knee-healthy controls, 12 (11%) sustained 13 ACL injuries. Players who returned had a >2-fold higher risk of a new ACL injury than players who did not return (risk ratio, 2.24; 95% CI, 1.27-3.93; P = .005) and a 4-fold higher risk than controls (risk ratio, 3.93; 95% CI, 2.23-6.91; P <.001). A new ACL, meniscal, or cartilage injury was the most frequent new knee injury. Among players who returned to soccer, 68% reported a new knee injury, and they had a 2- to 5-times higher risk of any new knee injury and knee surgery than players who did not return and controls.

CONCLUSION

Two-thirds of female soccer players with ACL reconstruction who returned to soccer sustained a new knee injury within 5 to 10 years; 42% had a new ACL injury. Their risk of a new knee injury and knee surgery was 2 to 5 times greater than that for players who did not return and for knee-healthy controls. New injury may have negative consequences for long-term knee health and should be a critical consideration in the decision to return to play.