Background Higher postoperative quadriceps function has been positively associated with surgical outcomes after anterior cruciate ligament reconstruction (ACLR). However, the impact of autograft harvest and/or a concomitant meniscal procedure on the recovery of quadriceps strength is not well defined. Purpose To describe postoperative recovery of quadriceps strength following ACLR related to autograft selection, meniscal status, and sex. Study Design Retrospective Cohort. Methods One hundred and twenty-five participants who underwent ACLR with either a hamstring tendon (HT), bone-patellar tendon-bone (BPTB) or quadriceps tendon (QT) autograft were included. At postoperative months 3, 6 and 9, each participant completed an isometric quadriceps strength testing protocol at 90-degrees of knee flexion. Participants’ quadriceps average peak torque (Q-AvgPKT), average peak torque relative to body weight (Q-RPKT), and calculated limb symmetry index (Q-LSI) were collected and used for data analysis. Patients were placed in groups based on sex, graft type, and whether they had a concomitant meniscal procedure at the time of ACLR. At each time point, One-way ANOVAs, independent samples t-test and chi-square analyses were used to test for any between-group differences in strength outcomes. Results At three months after ACLR, Q-RPKT was significantly higher in those with the HT compared to the QT. At all time points, males had significantly greater Q-RPKT than females and HT Q-LSI was significantly higher than BPTB and QT. A concomitant meniscal procedure at the time of ACLR did not significantly affect Q-LSI or Q-RPKT at any testing point. Conclusion This study provides outcomes that are procedure specific as well as highlights the objective progression of quadriceps strength after ACLR. This information may help better-define the normal recovery of function, as well as guide rehabilitation strategies after ACLR. Level of Evidence 3

Multiligament knee injuries (MLKIs) are debilitating injuries that increasingly occur in young athletes. Return to sport (RTS) has historically been considered unlikely due to the severity of these injuries. Reporting in the literature regarding objective outcomes following MLKI, including RTS, is lacking, as are clear protocols for both rehabilitation progressions and RTS testing. RTS following MLKI is a complex process that requires an extended recovery duration compared to other surgery types. Progressions through postoperative rehabilitation and RTS should be thoughtful, gradual, and criterion based. After effective anatomic reconstruction to restore joint stability, objective measures of recovery including range of motion, strength, movement quality, power, and overall conditioning guide decision-making throughout the recovery process. It is important to frame the recovery process of the athlete in the context of the severity of their injury, as it is typically slower and less linear. Improved reporting on objective outcomes will enhance our understanding of recovery expectations within this population by highlighting persistent deficits that may interfere with a full recovery, including RTS.M ultiligament knee injuries (MLKIs) are defined as a tear of 2 or more of the major knee ligaments, which include the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL), and lateral collateral ligament or fibular collateral ligament (FCL). 1,2 These devastating injuries are relatively uncommon, with more recent reports of 0.072 events per 100-patient years within the general population. 1,3,4 MLKIs are often associated with knee dislocation, defined as a rupture of both cruciates with or without additional grade III injury to one of the collaterals. 5 Disruption of the popliteal artery and/or common peroneal nerve (CPN) constitutes a medical emergency that can have devastating consequences if unrecognized. 6 MLKIs are seen more commonly in younger patients, with a mean age of 37 AE 15 years. 7,8 The incidence of knee dislocation has been inversely correlated with age. 7,8 MLKIs are often associated with high-energy trauma such as a motor vehicle accidents or fall from a height; however, nearly 50%, occur through a low-velocity mechanism, most commonly sport. 9,10 Rates of MLKI caused by skiing sports and ball sports are as high as 29.4% and 6.9%, respectively. In the same cohort, motor vehicle accidents only accounted for 19.2% of all injuries. 7 Given the severity of MLKI and the complexity of multiligament knee reconstruction (MLKR), return to sport (RTS) has historically been considered highly unlikely. RTS data have been inconsistent and incomplete, but existing evidence cites a RTS rate of 53%, 11 with competitive athletes having a lower RTS rate of 22%. 11 While surgical proficiency with MLKR has improved, RTS may be hindered by concerns regarding long-term joint health. MLKI patients show high rates of concomitant injury to articular cartilage (28.3%-48%) and men...

Do children and adolescents need nature? Increasingly, children and adolescents spend their life indoors and lose contact with nature. However, if one considers the needs of these children, it is clear that it is important for them to spend time in natural surroundings, where they can satisfy their needs for adventure, movement and independence. Often adolescents turn away from nature; however, if they have the possibility to make real nature experience, then nature can promote their personal development. Most important are teamwork, meaningful physical challenges and finding limits.

Anterior cruciate ligament reconstruction (ACLR) results in thigh muscle atrophy. Of the various interventions proposed to mitigate thigh muscle atrophy, exercise with blood flow restriction (BFR) appears safe and effective. Some literature suggests daily exposure to exercise with BFR may be indicated during the early phase of ACLR rehabilitation; this case report outlines the methodology utilized to prescribe clinic- and home-based BFR within an outpatient rehabilitation program. A 15-year-old male soccer player suffered a left knee injury involving the anterior cruciate ligament and both menisci. He underwent ACLR and completed exercise with BFR as part of his clinic- and home-based rehabilitation program, which included practical blood flow restriction during home-based rehabilitation. After 16 weeks of rehabilitation, surgical limb thigh girth values were objectively larger than the non-surgical limb (surgical, 52.25 cm; non-surgical 50 cm), as well as the multi-frequency bioelectrical impedance analysis of his lower-extremity lean body mass (surgical limb, 10.37 kg; non-surgical limb, 10.02 kg). The findings of this case report suggest that the inclusion of clinic- and home-based BFR within an outpatient rehabilitation program may be indicated to resolve thigh muscle atrophy early after ACLR.

BACKGROUND Few existing studies have examined the relationship between lower extremity bone length and quadriceps strength. PURPOSE/HYPOTHESIS To evaluate the relationship between lower extremity, tibia and femur lengths, and isometric quadriceps strength in patients undergoing knee surgery. The null hypothesis was that there would be no correlation between lower extremity length and isometric quadriceps strength. STUDY DESIGN Cross-sectional study METHODS Patients with full-length weightbearing radiographs that underwent isometric quadriceps strength testing after knee surgery were included. Using full-length weightbearing radiographs, limb length was measured from the ASIS to the medial malleolus; femur length was measured from the center of the femoral head to the joint line; tibia length was measured from the center of the plateau to the center of the plafond. Isometric quadriceps strength was measured using an isokinetic dynamometer. Pearson’s correlation coefficient was used to report the correlation between radiographic limb length measurements. A Bonferroni correction was utilized to reduce the probability of a Type 1 error. RESULTS Forty patients (26 males, 14 females) with an average age of 25.8 years were included. The average limb, femur, and tibia lengths were not significantly different between operative and non-operative limbs (p>0.05). At an average of 5.8±2.5 months postoperatively, the peak torque (156.6 vs. 225.1 Nm), average peak torque (151.6 vs. 216.7 Nm), and peak torque to bodyweight (2.01 vs 2.89 Nm/Kg) were significantly greater in the non-surgical limb (p<0.01). Among ligament reconstructions there was a significant negative correlation between both limb length and strength deficit (r= -0.47, p=0.03) and femur length and strength deficit (r= -0.51, p=0.02). The average strength deficit was 29.6% among the entire study population; the average strength deficit was 37.7% among knee ligament reconstructions. For the non-surgical limb, femur length was significantly correlated with peak torque (r = 0.43, p = 0.048). CONCLUSION Femur length was significantly correlated with the isometric quadriceps peak torque for non-surgical limbs. Additionally, femur length and limb length were found to be negatively correlated with quadriceps strength deficit among ligament reconstruction patients. A combination of morphological features and objective performance metrics should be considered when developing individualized rehabilitation and strength programs.