ACL reconstruction in 11 children using the Clocheville surgical technique: Objective and subjective evaluation.

INTRODUCTION: The over-the-top position of the femoral metaphyseal tunnel during extraphyseal ligament reconstruction of the anterior cruciate ligament (ACL) according to Clocheville may be responsible for negative anisometry. Until now, the follow-up of children operated using this pediatric technique was limited to screening for iatrogenic epiphysiodesis and the search for postoperative clinical instability. The objective of this study was to measure residual laxity using objective tests, to quantify muscle recovery, and to evaluate the quality of life of these patients in terms of the sports activities. MATERIAL AND METHODS: Eleven patients with a mean age of 13.5years were seen at a mean 2.1years of follow-up. They underwent objective clinical tests (GNRB(®) arthrometer and CON-TREX(®) dynamometer) as well as subjective questionnaires (IKDC and KOOS). RESULTS: No significant difference was found between the healthy knee and the operated knee for either the GNRB(®) at 134N (P=0.79) or at 200N (P=0.98). The CON-TREX(®) system allowed us to measure a median percentage of quadriceps recovery of 80.7% (range, 52.2-114.5) in terms of muscle power (60°/s) and 81.2% (range, 51.6-109.6) for muscle response (180°/s). The median subjective IKDC score was 94.73/100 (range, 73.68-98.93); 72.7% of the patients resumed competitive sports. DISCUSSION: This study's lack of statistical power did not show a significant difference in terms of residual laxity at rest of GNRB(®) transplants, while a mean differential of +0.4mm was observed. Although pediatric transphyseal ligament reconstruction techniques are increasingly used, the Clocheville technique remains, in our opinion, an attractive surgical alternative in the youngest subjects, with no major risk of iatrogenic epiphysiodesis even though it is theoretically anisometric. LEVEL OF EVIDENCE: IV.

The impact of recurrent dislocation on shoulder rotator muscle balance (a prospective study of 102 male patients).

PURPOSE OF THE STUDY: We performed an isokinetic analysis of both shoulders in 102 male patients suffering from shoulder instability after several trauma-related anterior or anterior-inferior dislocations. The analysis was part of a comprehensive medical and radiological assessment (with standard X-rays and cross-sectional imaging) prior to surgery. The study's objective was to measure the strength of the patients' internal and external rotators after recurrent dislocations (by comparing injured and healthy sides) and to evaluate the dislocations' impact on the muscles on the injured side. MATERIALS AND METHODS: The mean patient age was 24.8 (range: 16-47). We analysed the impact of instability on rotator muscle performance according to the side (dominant or non-dominant), the number of dislocations and the severity of any associated bone damage. The isokinetic analysis was performed at least one month after the last shoulder dislocation. The same operator performed all procedures. The modified Davies position was adopted, in order to record the peak torque of the internal and external rotators during concentric contractions at 60° and 180° per second. Means and standard deviations for peak torque to body weight ratios and external/internal rotator peak torque ratios were reported. RESULTS: After several anterior or anterior-inferior shoulder dislocations, there was a non-significant difference in the external rotator/internal rotator ratio when comparing injured and healthy sides - regardless of whether the injured side was dominant or not, the number of dislocations and the severity of bone damage. CONCLUSION: Systematic, presurgical, isokinetic testing of the shoulder does not appear to be of value in post-traumatic instability in male patients.

Ruptures of the anterior cruciate ligament in soccer.

Ruptures of the anterior cruciate ligament (ACL) are serious, common and costly injuries. The present 12-year investigation was undertaken to examine the frequency of ACL ruptures and identify the game events that may have contributed to the cause of these injuries in male soccer players across a French district. A retrospective questionnaire was used to record the players' age at the time of injury, laterality, standard of play, playing position and injured side. The characteristics of the injury situations were described in detail to investigate the game events involved in each case. A total of 934 ruptures was reported. Significantly more ruptures were sustained in a non-contact versus a contact situation (p<0.01). Of the total number of lesions, 34.5% occurred during a pivot action. The right knee was affected more than the left knee (p<0.001), irrespective of the dominant side of the player. Certain game events reported in the injury situations were shown to be related to player's age, standard and position. While these results have confirmed observations from previous investigations on ACL ruptures in soccer, the analysis of a considerably larger number of injury cases has brought new findings to the literature as well as recommendations for future research.

[Treatment of chronic anterior shoulder instability using a coracoid bone block (Latarjet procedure): 74 cases]. / Résultat de la butée coracoïdienne type Latarjet pour instabilité antérieure chronique de l'épaule.

PURPOSE OF THE STUDY: Results of the Latarjet procedure for chronic anterior shoulder instability using a coracoid block are known in terms of recurrence, but not in terms of apprehension. We studied a prospective consecutive series of shoulders treated with the Latarjet method in order to determine whether patients forget their shoulder or whether they are still bothered, particularly during sports activities. MATERIAL AND METHODS: The series included 74 patients with chronic anterior shoulder instability treated with a coracoid block according to the Latarjet procedure. Sixty-nine were available for review and 66 had complete radiographic explorations (93.2%). The Duplay score was used to classify sports activities. Mean age was 26.5 years; 90% of the patients practiced sports. The surgical procedure was performed by the same operator for 78% of patients. The Duplay score and the Constant score were determined and standard x-rays (four views) were obtained. Statistical analysis was performed with the chi-square test. Multivariate analysis was then applied to the subpopulation presenting persistent apprehension. RESULTS: Follow-up was at least 24 months, average follow-up 50 months. Four patients presented secondary dislocation and two subluxation; 85% of patients were satisfied, 6% were hesitant and 9% were dissatisfied. The Duplay score was: excellent (18.8%), good (49.9%), fair (20.2%) and poor (10.1%). External elbow rotation (RE1) was limited by 17.69 degrees compared with the other side. Eighty-seven percent of patients resumed their sports activity five months postoperatively on average; 34% presented persistent apprehension. This subpopulation was examined separately. Multivariate analysis demonstrated two significantly independent factors of persistent apprehension: recovery of RE1 at 30 days postop, and total recovery of R1 at last follow-up. The radiographies demonstrated degenerative lesions in 10.6% of patients. DISCUSSION: The satisfaction rate of 85% and the 9% failure rate are similar to earlier reports. Our series was however exceptional in terms of an unusually high rate of persistent apprehension. Statistical analysis did not demonstrate a significant link between the presence of hyperlaxity and persistent apprehension. Nevertheless, in patients with hyperlaxity associated with chronic anterior shoulder instability, we associate Latarjet coracoid block with Neer capsuloplasty.

Isokinetic and anterior cruciate ligament reconstruction with hamstrings or patella tendon graft: analysis of literature.

We report isokinetic results of anterior cruciate ligament reconstruction with patellar tendon or hamstring graft from the literature analysis. The literature was defined from two search "textwords": Isokinetic and Anterior cruciate ligament reconstruction, and from three databases: Medline, Pascal, and Herasmus. Two independent physicians (Physical Medicine and Rehabilitation) carried out an analysis according to the French National Accreditation and Health Evaluation Agency recommendations. Fifty-three studies were selected: 29 reported isokinetic results after anterior cruciate ligament reconstruction with patellar tendon graft, 15 reported isokinetic results after anterior cruciate ligament reconstruction with hamstring graft, and 9 studies compared the two surgical procedures. After discussing different bias and in reference to prospective randomised and comparative studies, the anterior cruciate ligament reconstruction with patellar tendon graft involves a knee extensors deficit during several months. The hamstring surgical procedure involves a less important knee extensor deficit (from 6 to 19 % against 8 to 21 %). Knee sprain and intra-articular surgery involve a long-lasting knee extensors deficit. Anterior cruciate ligament reconstruction with hamstrings graft involves a knee flexors deficit over several months. The patellar tendon surgical procedure involves a less important knee flexors deficit (from 1 to 15 % against 5 to 17 %). In reference to isokinetic parameters, no difference between the two surgical procedures (patellar tendon graft or hamstring graft) is shown after more than twenty-four post-surgical months.

[Eccentric isokinetic strengthening in hamstrings of patients with multiple sclerosis]. / Renforcement musculaire isocinétique excentrique des ischiojambiers chez des patients atteints de sclérose en plaque.

OBJECTIVE: To assess the benefit of a program of rehabilitation involving eccentric isokinetic muscle strengthening for hamstrings of patient with multiple sclerosis. PATIENTS AND METHODS: A total of 28 patients with multiple sclerosis and abnormalities when walking who underwent a program of rehabilitation involving eccentric isokinetic muscle strengthening associated with classical neurological rehabilitation. Assessment was by use of an isokinetic test, clinical examination and score on a visual analog scale (VAS) about quality of walking at the beginning and end of the rehabilitation program and three months later. The rehabilitation program involved eccentric isokinetic exercises during 12 sessions. RESULTS: Patients with multiple sclerosis and difficulty walking showed weak hamstrings on manual muscular testing. After 12 sessions of isokinetic eccentric rehabilitation, hamstring and quadriceps strength increased, VAS score increased, and recurvatum of the knee improved in 26 cases. Three months later, the score for quality of walking remained the same, but that for strength returned to a previous level. CONCLUSION: Hamstring strength in patients with multiple sclerosis can be improved without complication with use of eccentric isokinetic rehabilitation. This is an interesting way to improve the quality of walking in these patients.

[Isokinetic thigh muscle strength in sports: a review]. / Evaluation isocinétique des extenseurs et fléchisseurs du genou en médecine du sport: revue de la littérature.

There is growing evidence that isokinetic muscle strength, is one of the most common testing method why muscle strength is thought to be a major factor in athletic success and rehabilitation. A lot of publications during the last 20 years concerned the peak torque, the concentric ratio flexor/extensor, with comparison between males and females, sport specialties, young and old people. Isokinetic is also used for evaluation of knee disorders. The results are very useful after knee ligament surgery, less for femoro-patellar disorders and arthrosis. More recently some authors proposed the functional concept (eccentric flexors/concentric extensors ratio) as a predictive method for preventive muscle injuries or ACL lesions. They demonstrated more discomfort after muscle disorders with isokinetic eccentric testing, and proposed rehabilitation programs for prevention. However apart from a few situations, isokinetic testing does not fully predict functional measurements. It must be used with other techniques of evaluation (clinical methods and imagery).

[Consequences and prediction of hamstring muscle injury with concentric and eccentric isokinetic parameters in elite soccer players]. / Conséquences et prédiction des lésions musculaires des ischiojambiers à partir des paramètres isocinétiques concentriques et excentriques du joueur de football professionnel.

OBJECTIVE: To know if isokinetic parameters identify previous hamstring (H) injury and predict a new muscle injury in high-level soccer player. METHOD: Concentric (con) and eccentric (ecc) isokinetic torque was measured at the angular speed of 60 degrees /s in 28 elite soccer players (23 years +/- 3.3; 74 kg +/- 7.5; 178 cm +/- 6.5). First, 11 players, victims of 15 moderate or major hamstring injuries in the preceding 2 years, were compared with 17 players without previous hamstring injury. Comparisons were carried out from isokinetic knee flexors-extensors ratios [Hcon/Qcon and Hecc/Qcon] and bilateral knee flexors ratios [Hcon/Hcon and Hecc/Hecc]. Secondly, all the population was followed during 12 months and the isokinetic muscular profile of players who presented a recurrence or a new hamstring muscle injury was analysed. RESULTS: A concentric ratio hamstring-to-quadriceps lower than 0.6 and a hamstring asymmetry of more than 10% do not allow to identify previous hamstring injury. On the other hand, the mixed ratio eccentric hamstring-to-concentric quadriceps lower than 0.6 represents the best indicator (probability: 77.5%). The rate of recurrence is 30% (three cases of 10) and the rate of new hamstring muscle injury is 31% (five cases of 16) (P > 0.05). One of the five injured soccer players presented a concentric ratio hamstring-to-quadriceps lower than 0.6 and no player presented a mixed ratio lower than 0.6. However, four of the five injured players presented a concentric and an eccentric asymmetry. But, it is the strongest side, which presented a new hamstring muscle injury. CONCLUSION: The mixed ratio eccentric hamstring-to-concentric quadriceps lower than 0.6 identify a previous hamstring injury despite the resumption of competitive soccer. However, this ratio and the others isokinetic studied parameters do not predict a recurrence or a new hamstring muscle injury.

[Evaluation of pendulum testing of spasticity]. / Evaluation de la mesure de la spasticité par le pendulum test.

OBJECTIVES: To identify valid measurements of spasticity derived from the pendulum test of the leg in a representative population of spastic patients. MATERIAL AND METHODS: Pendulum testing was performed in 15 spastic and 10 matched healthy subjects. The reflex-mediated torque evoked in quadriceps femoris, as well as muscle mechanical parameters (viscosity and elasticity), were calculated using mathematical modelling. Correlation with the two main measures derived from the pendulum test reported in the literature (the Relaxation Index and the area under the curve) was calculated in order to select the most valid. RESULTS, DISCUSSION: Among mechanical parameters, only viscosity was found to be significantly higher in the spastic group. As expected, the computed integral of the reflex-mediated torque was found to be larger in spastics than in healthy subjects. A significant non-linear (logarithmic) correlation was found between the clinically-assessed muscle spasticity (Ashworth grading) and the computed reflex-mediated torque, emphasising the non-linear behaviour of this scale. Among measurements derived from the pendulum test which are proposed in the literature for routine estimation of spasticity, the Relaxation Index exhibited an unsuitable U-shaped pattern of variation with increasing reflex-mediated torque. On the opposite, the area under the curve revealed a linear regression, which is more convenient for routine estimation of spasticity. CONCLUSION: The pendulum test of the leg is a simple technique for the assessment of spastic hypertonia. However, the measurement generally used in the literature (the Relaxation Index) exhibits serious limitations, and would benefit to be replaced by more valid measures, such as the area under the goniometric curve, especially for the assessment of therapeutics.

A comprehensive model of spastic hypertonia derived from the pendulum test of the leg.

We propose a comprehensive model of spastic hypertonia based on clinical neurophysiology and validated using experimental data obtained from the pendulum test of the leg in 8 healthy volunteers and 15 spastic patients. This nonlinear computational model includes mechanical parameters and a stretch reflex representation involving three neural parameters: a threshold coefficient, the gain of the stretch reflex, and a time lag accounting for the reflex loop latency and the electromechanical coupling delay. Variation of the threshold coefficient alone allowed an overall reproduction of experimental data obtained from spastic and healthy subjects. We propose that this parameter could represent the supraspinal drive, supposed to be preserved in control subjects and decreased in spastic patients. No subsequent variation of the reflex gain was required to simulate spastic traces. Adjustment of the time lag influenced the duration of the swinging phase and oscillatory phenomena possibly occurring during the pendulum test. It could be related to the involvement of either short- or long-latency stretch reflex loops. With respect to current neurophysiological concepts of motor control, this modeling approach may help in understanding mechanisms underlying spastic hypertonia, and in predicting the clinical effect of antispasticity agents.

Blood lactate concentrations during exercise: effect of sampling site and exercise mode.

BACKGROUND: The purpose of the study was to compare blood lactate concentrations determined in blood sampled from three sites (finger capillary, ear-lobe capillary, and forearm vein) during exercise on three different ergometers (a cycle ergometer, a treadmill and an arm-crank ergometer). METHODS: A total of 312 well-trained subjects performed either a six-minute steady-state exercise (n = 219) or an incremental exercise test until exhaustion (n = 93). Blood was sampled from two sites after each exercise test and at the end of each stage of the incremental protocol, 852 pairs of blood samples were analysed. RESULTS: Results showed that, when exercise was performed on a cycle ergometer or a treadmill, no significant differences between venous and ear capillary samples were observed whereas finger capillary values were higher. On an arm-crank ergometer, venous and finger capillary lactate concentrations were usually higher than ear capillary values with some discrepancies depending on the times of sampling. CONCLUSIONS: We conclude that lactate values may differ depending on the sampling site and the type of exercise mode. An ear capillary sample may be preferred because it is less affected by lactate release in the arms and easier to obtain.

Gender effect on the relationship of time limit at 100% VO2max with other bioenergetic characteristics.

The aim of this study was to investigate the influence of gender on the possible contribution of tlim at Va max (minimal speed that elicits VO2max) in performance speeds. The male and female elite middle-distance runners had similar performance (IAAF scores). Fourteen female and fifteen male (25.2 +/- 3.6 and 25.1 +/- 4.2 yr old; VO2max = 63.2 +/- 4.2 and 77.7 +/- 6.4 ml.kg-1 min-1; Va max = 17.3 +/- 0.7 and 20.8 +/- 1.1 km.h-1, respectively) performed three exercise tests on a treadmill (3 degrees slope) within a 2-wk period: an incremental test to determine VO2max, Va max and the velocity at the onset of blood lactate accumulation (VOBLA); an exhaustive constant velocity test to determine tlim at Va max; and an exhaustive constant velocity test at 110% Va max to determine the accumulated oxygen deficit (AOD). There were no effects of gender, i.e., no significant differences were observed between female and male for tlim at Va max (421 +/- 129 vs 367 +/- 118 s respectively; P = 0.24), VOBLA as % Va max (88.4 +/- 2.7 vs 90.4 3% of Va max; P = 0.07), AOD (40.1 +/- 14.9 vs 48.9 +/- 21.3 ml.O2.kg-1; P = 0.22), running economy at the same absolute speed, i.e., 14 km.h-1 (53.4 +/- 2.6 vs 52.7 +/- 4.1 ml.O2.min-1.kg-1; P = 0.64) nor for gross oxygen cost of running (CR) at the same relative velocity (75% Va max) (0.214 +/- 0.001 vs 0.214 +/- 0.002 ml.O2.kg-1.m-1; P = 0.94). However, an effect of gender was found on the relationship between the bioenergetic parameters and performance. For male, v1500 was predicted by Va max, VOBLA, tlim at 110% of Va max, and CR (R2 = 0.96). For female, no bioenergetic parameters were strongly correlated with v1500 m. The inverse relationship found between Va max and tlim at Va max in previous literature was confirmed by the 29 runners in this study and for the subset of male only.

Energy consumption of paraplegic locomotion using reciprocating gait orthosis.

The energy cost of walking using a reciprocating gait orthosis (RGOII) with functional electrical stimulation (FES) was assessed in 14 patients with spastic complete paraplegia from six rehabilitation centres. Before and after training asing RGOII with FES, the subjects performed a progressive maximal test on an arm-crank ergometer to obtain their laboratory peak oxygen uptake (LVO2peak), heart rate (HR) and blood lactate concentration changes. At the end of the training session, oxygen uptake (VO2) was measured during a walking test with orthosis at different speeds (6 min steady state at 0.1 m.s-1, followed by 2-min stages at progressively increasing speeds up to exhaustion). Of the subjects 4 repeated this test using orthosis without FES. At a speed of 0.1 m.s-1, VO2 represented 47 (SD 23)% of LVO2peak, mean HR was 137 (SD 21) beats.min-1 and mean blood lactate concentration 2.4. (SD 1.4) mmol.l-1. Maximal speed ranged from 0.23 to 0.5 m.s-1. At maximal speed, VO2 was 91 (SD 18)% of LVO2peak, mean HR reached 96 (SD 7)% and mean blood lactate concentration only 52 (SD 19)% of the maximal values measured during the laboratory test. Walking without electrical stimulation induced an increase in HR but there was no difference in VO2 and blood lactate compared to walking with stimulation. The training period did not result in any improvement in maximal physiological data. We concluded that the free cadence walking speed with orthosis remains much lower than that of able-bodied people or wheelchair users. The metabolic cost at a given speed is much higher even if, using a stimulation device, the cardiovascular stress is reduced.

Multiparametric classification of muscle T1 and T2 relaxation times determined by magnetic resonance imaging. The effects of dynamic exercise in trained and untrained subjects.

Muscle relaxation times can now be measured accurately with magnetic resonance imaging (MRI), distinguishing working muscles from non-working muscles. A correlation between T2 increase and work intensity has been shown in healthy volunteers. The small amount of data on T1 relaxation times is contradictory. In addition, all the published studies have concerned short-duration exercise in subjects of unknown training level. The goals of this study were (i) to determine T1 and T2 variations in thigh muscles after long dynamic exercise, (ii) to analyse the effects of training and (iii) to determine the relationship between power output and relaxation times after exercise. Sedentary men, soccer players and tri-athletes performed submaximal dynamic exercise at a constant heart rate for 15 min. MRI was performed before and 5 min after the end of exercise. The results showed (i) that T1 increased in parallel to T2 in anterior thigh muscles and (ii) that multiple correspondence analysis and hierarchical ascending classification can discriminate three subjects classes according to power output, training level and relaxation times, which fitted well with our three groups of subjects.

Use of oxygen uptake recovery curve to predict peak oxygen uptake in upper body exercise.

A group of 18 well-trained white-water kayakers performed maximal upper body exercise in the laboratory and during a field test. Laboratory direct peak oxygen uptake (VO2) values were compared, firstly by a VO2 backward extrapolation estimation and secondly by an estimation calculated from VO2 measured during the first 20 s of exercise recovery. Direct peak VO2 correlated with VO2 backward extrapolation (r = 0.89), but the results of this study showed that the backward extrapolation method tended to overestimate significantly peak VO2 by [0.57 (SD 0.31) l.min-1 in the laboratory, and 0.66 (SD 0.33) l.min-1 in the field, P < 0.001]. The VO2 measured during the first 20 s of recovery, whether the exercise was performed in the laboratory or in the field, correlated well with the laboratory direct peak VO2 (r = 0.92 and r = 0.91, respectively). The use of the regression equation obtained from field data (VO2F20s), that is peak VO2 = 0.23 + 1.08 VO2F20s, gave an estimated peak VO2, the mean difference of which compared with direct peak VO2 was 0.22 (SD 0.13) l.min-1. In conclusion, we propose the use of a regression equation to estimate peak VO2 from a single sample of the gas expired during the first 20 s of recovery after maximal exercise involving the upper part of the body.

[Comparative urinary elimination of caffeine in sedentary and sportsmen after administration of Guronsan]. / Elimination urinaire comparée de la caféine chez le sédentaire et le sportif aprés administration de GURONSAN.

The authors present the results of a study on urinary excretion of caffeine, after a single oral intake of 100 mg of caffeine, in two populations of students at rest and during exercise. Whether expressed in mg/l or mg/g creatinine no significant difference in urinary excretion of caffeine was observed between the two populations and it proves to be lower than the limit level authorized by the IOC (12 mg/l).

Effects of captopril chronic intake on the aerobic performance and muscle strength of normotensive trained subjects.

Fifteen normotensive athletes specializing in dynamic sports took part in a randomized double-blind and cross-over study: captopril (50 mg/24 h) vs placebo. Each treatment lasted one month. Maximal exercise tests on cycle ergometer were performed at the end of each period. No significant differences were observed in the maximal values of oxygen uptake, power, heart rate or blood lactate value. The anaerobic threshold, defined as the exercise intensity which corresponded to a 4 mmol.l-1 blood lactate level was unchanged. With captopril, the end-of-exercise systolic and diastolic BP were slightly altered (NS). Lower limb muscle strength, as explored with a Cybex isokinetic system, was not modified by captopril intake. The results indicate that maximal aerobic performance and isokinetic strength of the lower limbs are not altered by captopril chronic administration (50 mg/day) in normotensive trained subjects.