Patient expectations and perceived social support related to return to sport after anterior cruciate ligament reconstruction in adolescent athletes

ObjectiveExamine the relationship between pre-operative competitive status and return to sport expectations post-operatively among adolescents undergoing ACL reconstruction. Assess the association between perceived levels of social support and doubts in returning to sport after ACL reconstruction.DesignCross-sectional.SettingOutpatient sports medicine clinic at a single institution.Participants12–18 years old with an ACL tear who were planning to undergo ACL reconstruction.Main outcome measuresPsychovitality questionnaire responses and Multidimensional Scale of Perceived Social Support (MSPSS) questionnaire scores.Results86% of participants expected to return to sports in six months or less after surgery; there was no significant difference in expected time to return to sport between competitive vs. recreational athletes. Competitive athletes were less likely to be content returning to a lower activity level after surgery compared to recreational athletes. There were no significant differences in MSPSS scores between those who did and did not report doubts in their ability to return to their previous sports.ConclusionMost of our adolescent athlete population expected to return to sport after ACL reconstruction within six months of surgery. Those with and without doubts in their ability to return to sports did not significantly differ in levels of perceived social support.     

Does the anterolateral ligament protect the anterior cruciate ligament in the most common injury mechanisms? A human knee model study

BackgroundAnterior cruciate ligament (ACL) reconstruction still has a risk of re-rupture and persisting rotational instability. Thus, extra-articular structures such as the anterolateral ligament (ALL) are increasingly treated. The ALL however prevents the internal rotation of the tibia and it must be doubted that the ALL protects the ACL in other common injury mechanisms which primarily include tibial external rotation. In this study we aimed to evaluate which extra-articular structures support the ACL in excessive tibial internal and external rotation using a knee finite element (FE) model.MethodsInternal and external rotations of the tibia were applied to an FE model with anatomical ACL, posterior cruciate ligament (PCL), lateral collateral ligament (LCL), medial collateral ligament (MCL) and intact medial and lateral meniscus. Three additional anatomic structures (anterolateral ligament, popliteal tendon and posterior oblique ligament) were added to the FE model separately and then all together. The force histories within all structures were measured and determined for each case.ResultsThe ACL was the most loaded ligament both in tibial internal and external rotation. The ALL was the main stabilizer of the tibial internal rotation (46%) and prevented the tibial external rotation by only 3%. High forces were only observed in the LCL with tibial external rotation. The ALL reduced the load on the ACL in tibial internal rotation by 21%, in tibial external rotation only by 2%. The POL reduced the load on the ACL by 8%, the PLT by 6% in tibial internal rotation. In tibial external rotation the POL and PLT did not reduce the load on the ACL by more than 1%.ConclusionThe ALL protects the ACL in injury mechanisms with tibial internal rotation but not in mechanisms with tibial external rotation. In injury mechanisms with tibial external rotation other structures that support the ACL need to be considered.     

Delaying ACL reconstruction beyond 6 months from injury impacts likelihood for clinically significant outcome improvement

BackgroundThe effect of surgical latency on outcomes of anterior cruciate ligament reconstruction (ACLR) is a topic that is heavily debated. Some studies report increased benefit when time from injury to surgery is decreased while other studies report no benefit. The purpose of our analysis was to compare achievement of clinically significant outcomes (CSOs) in patients with greater than six months of time from injury to ACLR to those with less than or equal to six months of time to surgery.MethodsPatients undergoing primary ACLR between January 2017 and January 2018 with minimum one year follow-up were included. International Knee Documentation Committee (IKDC) score and Knee Injury and Osteoarthritis Outcomes Score (KOOS) were collected. Multivariate logistic regression was performed for outcome achievement and risk of revision ACLR and Weibull parametric survival analysis was performed for relative time to outcome achievement. The level of significance was set at α = 0.05.Results379 patients were included of which, 140 patients sustained ACL injury greater than six months prior to surgery. This group of patients experienced reduced likelihood to achieve patient-acceptable symptomatic state (PASS) on the IKDC (p = 0.03), KOOS Pain (p = 0.01) and a greater likelihood to undergo revision ACLR (p = 0.001). There was no impact of surgical timing on minimal clinically important difference (MCID).ConclusionPatients with greater than 6 months from injury to ACLR reported reduced likelihood to achieve CSOs, delayed achievement of CSOs, and increased rates of revision surgery.     

Association between ankle angle at initial contact and biomechanical ACL injury risk factors in male during self-selected single-leg landing

BackgroundIncreasing the ankle plantar-flexion angle at initial contact (IC) during landing reduces the impact features associated with landing, such as the vertical ground reaction force and loading rate, potentially affecting the risk of anterior cruciate ligament (ACL) injury. However, the relationships between the ankle plantar-flexion angle at IC and the previously identified biomechanical factors related to noncontact ACL injury have not been studied.Research questionThus, the purpose of this study was to determine whether significant relationships exist between the ankle plantar-flexion angle at IC and the biomechanical factors related to noncontact ACL injury.MethodsThe peak anterior tibial shear force, peak external knee valgus moment, peak knee valgus angle, and combined peak external knee valgus plus tibial internal rotation moments were measured in 26 individuals while performing self-selected, single-leg landing. Pearson correlation analyses were performed to assess the relationships between the ankle plantar-flexion angle at IC and the biomechanical factors mentioned above.ResultsThe greater ankle plantar-flexion angle at IC was related to smaller the peak knee valgus moment (r = −0.5, p = 0.009) and the combined peak knee valgus plus internal rotation moments (r = −0.58, p = 0.001).SignificanceThese results suggest that large ankle plantar-flexion angle at IC might be associated with lesser loading of the knee frontal plane and altering the self-selective ankle angle may result in biomechanical changes associated with ACL injury risk.     

Electron beam sterilization does not have a detrimental effect on the ability of extracellular matrix scaffolds to support in vivo ligament healing

Extracellular matrix (ECM) scaffolds have been used to enhance anterior cruciate ligament (ACL) repair in large animal models. To translate this technology to clinical care, identifying a method which effectively sterilizes the material without significantly impairing in vivo function is desirable. Sixteen Yorkshire pigs underwent ACL transection and were randomly assigned to bridge‐enhanced ACL repair—primary suture repair of the ACL with addition of autologous blood soaked ECM scaffold—with either (i) an aseptically processed ECM scaffold, or (ii) an electron beam irradiated ECM scaffold. Primary outcome measures included sterility of the scaffold and biomechanical properties of the scaffold itself and the repaired ligament at 8 weeks after surgery. Scaffolds treated with 15 kGy electron beam irradiation had no bacterial or fungal growth noted, while aseptically processed scaffolds had bacterial growth in all tested samples. The mean biomechanical properties of the scaffold and healing ligament were lower in the electron beam group; however, differences were not statistically significant. Electron beam irradiation was able to effectively sterilize the scaffolds. In addition, this technique had only a minimal impact on the in vivo function of the scaffolds when used for ligament healing in the porcine model. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1015–1023, 2015.     

Anatomical Reconstruction of the Anterior Cruciate Ligament in Goats

A surgical procedure was developed for the implantation of an anatomical, two-banded anterior cruciate ligament (ACL) prosthesis. Prostheses were fabricated of braided long-chain polyethylene fibers. The left ACL of adult male goats was surgically excised and replaced with either an anatomical reconstruction (5 goats) or a conventional reconstruction (5 goats). The anatomical reconstruction required drilling four bone tunnels, two each in the femur and tibia. Each band of the prosthesis was placed through one tunnel in the femur and the corresponding tunnel in the tibia, recreating the anteromedial and posterolateral bands. The two bands were tensioned independently and stapled in place. In the conventional procedure, the prosthesis was doubled and placed through two larger tunnels, one in the femur and one in the tibia, tensioned and stapled together. All animals were terminated 3 months after surgery. Clinical evaluation of passive range of motion, anlero-poslerior laxity and the appearance of the joint space showed little or no difference between the reconstruction methods. The ultimate failure load for the natural (unoperated) ACL was 1691 ± 210 N, while the anatomical and conventional reconstruction groups had mean ultimate failure loads of 1233 ± 732 and 1012 ± 220 N, respectively. The elongation to failure of all groups was similar: the natural ACL group = 7.1 ± 2.8 mm, the anatomical group = 7.2 ± 2.9 mm, and the conventional group = 7.7 ± 3.9 mm. The slope of the load-deformation curve, or stiffness, was significantly higher for the natural ACL (4.53 ± 1.24 × 10⁵ N/m) than for either of the reconstruction methods (2.75 ± 1.59 × 10⁵ N/m for the anatomical and 2.34 ± 0.60 × 10⁵ N/m for the conventional). The energy to failure, or area under the load-deformation curve, showed no significant difference between groups. In conclusion, both types of reconstructions were less strong, stiff, and tough than the natural ACL. There was no significant difference observed between the anatomical and conventional reconstruction methods over the 3-month implantation time in either clinical evaluation or mechanical testing. Therefore, at 3 months postsurgery, the anatomical reconstruction technique was considered no better and no worse than the conventional reconstruction technique     

Semitendinosus tendon regeneration after anterior cruciate ligament reconstruction: can we use it twice?

Purpose

It has been demonstrated that the semitendinosus tendon can regenerate after being harvested in its whole length and thickness for anterior cruciate ligament (ACL) reconstruction. Ultrasound studies and guided biopsies of the regenerated tendon have shown compatibility and resembling features of the normal tendon. The question is if this neo-tendon is biologically and functionally adequate for re-use?

Methods

Two randomised groups of 150 volunteers were followed up for two years after harvesting the semitendinosus only (25) or the semitendinosus and gracilis tendons (25) in ACL reconstruction. The patients were followed up with clinical and ultrasound examinations, biopsies and histological tests. Surgical exploration was done in three patients for macroscopic verification. The injected arteries of four lower limbs were dissected and the tendon’s arterial supplies were examined.

Results

Seventy-two percent of the cases showed regeneration of the semitendinosus tendons. The neotendons were inserted mostly below the knee joint (83.3 %) where they had fused with the gracilis tendon, and above the joint (60 %) when the gracilis was harvested as well. The isokinetic strength of the hamstrings and quadriceps was not significantly diminished on the operated side. A macroscopic and histological analysis of the regenerated tendons demonstrates close resemblance to normal anatomy, with focal areas of fibrosis. In one patient the regenerated tendon was used for medial patellofemoral ligament reconstruction.

Conclusion

The semitendinosus muscle can recover and the tendon has great potential to regenerate after harvesting for ACL reconstruction. Our data suggest that the regenerated tendons could be used for iterative ligament reconstruction.     

Ankle Dorsiflexion displacement is associated with hip and knee kinematics in females following anterior cruciate ligament reconstruction

The purpose of this study was to examine associations between ankle dorsiflexion (ankle-DF) displacement and knee and hip kinematics and kinetics during a jump-landing task in females following anterior cruciate ligament reconstruction (ACLR). Females (n = 23) with a history of unilateral ACLR (≥ 6-months post-ACLR) underwent a three-dimensional lower extremity biomechanical evaluation. Pearson Product Moment (r) correlations assessed associations between ankle-DF displacement and knee and hip kinematic and kinetic variables. On the involved-limb, individuals with lesser ankle-DF displacement demonstrated greater knee abduction displacement during the loading phase (r = -0.645, p = 0.001). On the uninvolved-limb, individuals with greater ankle-DF displacement demonstrated greater hip flexion displacement (r = 0.599, p = 0.003) and knee flexion displacement (r = -0.545, p = 0.007). There were no other significant associations between ankle-DF displacement and ankle, knee, or hip biomechanical variables on either limb (p > 0.05). Our findings demonstrate that reduced ankle-DF motion appears to share a different relationship between the involved- and uninvolved-limbs in females post-ACLR.