Dynamic Effect of Quadriceps Muscle Activation on Anterior Tibial Translation After Single-Bundle and Double-Bundle Anterior Cruciate Ligament Reconstruction.

PURPOSE: To examine differences in anterior tibial translation in 3 groups: single-bundle anterior cruciate ligament (ACL)-reconstructed, double-bundle ACL-reconstructed, and ACL-intact knees under gradual dynamic quadriceps muscle activation. METHODS: Thirty male patients underwent successful single-bundle (n = 15) and double-bundle (n = 15) ACL reconstructions; 15 healthy controls were included in the study. Anterior tibial translation was assessed at 30° of knee flexion in the resting position (0% quadriceps activation) and under 50% and 100% of maximum quadriceps concentric contraction using an isokinetic dynamometer with the KT-2000 arthrometer securely attached to the participants' knees. RESULTS: The 2 ACL-reconstructed groups were similar regarding International Knee Documentation Committee (IKDC), Knee Injury and Osteoarthritis Score (KOOS), Tegner, and Lysholm scores and preliminary isokinetic evaluation (P = .38). Quadriceps activation significantly affected anterior tibial translation (P = .001, α = 0.98). In all 3 study groups, anterior tibial translation was significantly higher under 100% quadriceps activation compared with 0% contraction (P = .01) and 50% quadriceps activation (P = .047). There were no between-group differences in anterior tibial translation with 0%, 50%, or 100% quadriceps activation (P = .46). CONCLUSIONS: Under quadriceps muscle activation, anteroposterior knee laxity in ACL-intact and ACL-reconstructed knees is gradually increased. Single-bundle and double-bundle ACL-reconstructed knees show a similar increase in anterior tibial translation under gradual quadriceps contraction. When comparing different ACL reconstruction techniques in the experimental setting, dynamic, in addition to static, testing is advised to reach a comprehensive assessment of anteroposterior knee stability. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Lower limb clinical and radiographic osteoarthritis in former elite male athletes.

PURPOSE: To investigate the prevalence of lower extremities clinical and radiographic OA in former elite male athletes and referents from the general population and to examine its association with the participants' demographic characteristics. METHODS: Two hundred and eighteen former elite male athletes (soccer, volleyball, martial arts, track and field and basketball players, and skiers) and 181 male controls that reported no systematic athletic activity were examined by means of questionnaire, clinical and radiographic evaluation. Exclusion criteria were age younger than 40 years and a positive history of lower extremity surgery, bone or soft tissue trauma and inflammatory arthropathy. RESULTS: Overall, the prevalence of clinical OA between former elite athletes (15.6 %) and controls (14.4 %) was similar (n.s.). The prevalence of radiographic OA was significantly higher (p = 0.03) in former elite athletes (36.6 %) compared with controls (23.9 %). All the participants with clinical OA who underwent radiographic examination also had radiographic OA. The prevalence of clinical and radiographic OA was similar (n.s.) between former athletes of different sports. Age, body mass index (BMI) and occupation variably predicted the prevalence of hip, knee and ankle OA in both study groups. CONCLUSIONS: In the absence of major bone and soft tissue lower limb trauma during their athletic career, former elite athletes may not be at increased risk of developing clinical OA. Radiographic signs of OA present at a significantly higher incidence and possibly precede the clinical onset of OA. Age, BMI and occupation are identified as strong predictors of the development of OA in former elite athletes.

Tourniquet use does not affect rehabilitation, return to activities, and muscle damage after arthroscopic meniscectomy: a prospective randomized clinical study.

PURPOSE: The purpose of this prospective randomized trial was to examine the effect of tourniquet use on rehabilitation rate, return to work and sport activities, and muscle damage after arthroscopic meniscectomy. METHODS: Eighty patients who underwent arthroscopic partial meniscectomy were randomly allocated to the use of an inflated (group A, n = 40) or deflated (group B, n = 40) pneumatic tourniquet. Patients with concomitant ligamentous deficiency or grade III and IV chondral lesions were excluded. The primary outcome measures were pain, measured with a visual analog scale (VAS), and knee range of motion (ROM) on days 8 and 15 postoperatively; time required for patients to discontinue the use of crutches; time to return to light activities and moderate sporting activities such as jogging; and serum creatine phosphokinase (CPK) levels monitored preoperatively and on days 1, 8, and 15 postoperatively. RESULTS: The 2 groups did not differ in terms of age; male-female ratio; body mass index; and preoperative International Knee Documentation Committee, Tegner, and Lysholm scores. Operative time was not significantly different between groups (mean, 27.5 for group A and 31.2 for group B; P = .83). VAS pain scores and knee ROM were not significant between groups (minimum P = .22). The patients progressed to weight-bearing without crutches within 13.4 and 12.9 days for groups A and B, respectively (P = .9). Return to work and jogging did not differ significantly between groups (minimum P = .34). Serum CPK values were also not significantly different between or within groups during consecutive measurements (P = .3). Tourniquet time did not significantly affect postoperative ROM, VAS pain scores, or serum CPK levels (minimum P = .14). CONCLUSIONS: Tourniquet use for less than 30 minutes during arthroscopic meniscectomy does not affect postoperative pain or return to light work and jogging. In addition, tourniquet-induced muscle damage after arthroscopic meniscectomy, though potentially present locally, is not detectable in the systemic circulation. LEVEL OF EVIDENCE: Level I, prospective randomized trial.

Tibial rotation under combined in vivo loading after single- and double-bundle anterior cruciate ligament reconstruction.

PURPOSE: To evaluate in vivo the differences in tibial rotation between single- and double-bundle anterior cruciate ligament (ACL)-reconstructed knees under combined loading conditions. METHODS: An 8-camera optoelectronic system and a force plate were used to collect kinematic and kinetic data from 14 patients with double-bundle ACL reconstruction, 14 patients with single-bundle reconstruction, 12 ACL-deficient subjects, and 12 healthy control individuals while performing 2 tasks. The first included walking, 60° pivoting, and stair ascending, and the second included stair descending, 60° pivoting, and walking. The 2 variables evaluated were the maximum range of internal-external tibial rotation and the maximum knee rotational moment. RESULTS: Tibial rotation angles were not significantly different across the 4 groups (P = .331 and P = .851, respectively) or when side-to-side differences were compared within groups (P = .216 and P = .371, respectively) for the ascending and descending maneuvers, nor were rotational moments among the 4 groups (P = .418 and P = .290, respectively). Similarly, for the descending maneuver, the rotational moments were not significantly different between sides (P = .192). However, for the ascending maneuver, rotational moments of the affected sides were significantly lower by 20.5% and 18.7% compared with their intact counterparts in the single-bundle (P = .015) and double-bundle (P = .05) groups, respectively. CONCLUSIONS: High-intensity activities combining stair ascending or descending with pivoting produce similar tibial rotation in single- and double-bundle ACL-reconstructed patients. During such maneuvers, the reconstructed knee may be subjected to significantly lower rotational loads compared with the intact knee. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Three-dimensional kinematic and kinetic analysis of knee rotational stability after single- and double-bundle anterior cruciate ligament reconstruction.

PURPOSE: To investigate whether anatomic restoration of the anterior cruciate ligament (ACL) functional bundles results in significant reduction in transverse-plane instability compared with the conventional single-bundle technique during a dynamic 60 degrees pivoting maneuver with the supporting knee in extension. METHODS: Using an 8-camera optoelectronic system and a force plate, we examined 10 patients with double-bundle ACL reconstruction, 12 patients with single-bundle reconstruction, 10 ACL-deficient subjects, and 10 healthy control individuals. The 4 groups did not differ in terms of age, body mass index, duration of follow-up, and number of meniscectomies performed. Kinematic and kinetic data were collected from these subjects while performing a pivoting maneuver on each side with the supporting knee in extension. Maximum range of motion for internal-external knee rotation and maximum knee rotational moment were examined. RESULTS: There was no significant difference in tibial rotation either between the 4 groups or between sides. The mean knee rotation for the single- and double-bundle groups was lower than the control group. Rotational moment values were substantially reduced on the affected side of the reconstructed and the ACL-deficient groups. However, rotational moment was not found to affect the degree of angular displacement significantly. CONCLUSIONS: Double-bundle ACL reconstruction does not reduce knee rotation further compared with the single-bundle reconstruction technique. The affected side of ACL-deficient or -reconstructed individuals is subjected to reduced knee rotational moments compared with the intact side during stressful functional maneuvers. LEVEL OF EVIDENCE: Level III, retrospective comparative study.