Ultrasound measurement of the anterior leg compartment

Eight male subjects, weighing 65 to 83 kg and between 22 and 34 years of age, were measured for depth changes in the anterior leg compartment at rest and following treadmill running and weighted dorsiflexion exercises. Measurements were obtained from ultrasound scans at two points on the leg. The results showed no significant differences in the compartment's depth between rest and treadmill exercise, while significant changes were noted between rest and dorsiflexion exercises. These results suggest that the anterior leg muscles were maximally functioning during the dorsiflexion exercises, but not during the treadmill exercises. It is concluded that the ultrasound can be used to detect depth changes, and hence volume changes, in muscle compartments and may have potential use in combination with other techniques as a noninvasive diagnostic tool in assessing changes in a muscle compartment.     

Functional analysis of anterior cruciate ligament braces

Whether or not anterior cruciate ligament (ACL) braces work has been the subject of some debate. Research efforts undertaken to understand these braces have been divided into two fronts: static and functional analysis. This article explores those issues surrounding the functional analysis of ACL braces.     

Exercise induced leg pain-chronic compartment syndrome. Is the increase in intra-compartment pressure exercise specific?

Intra-compartment pressure studies remain the main investigative method in diagnosing chronic compartment syndrome (CCS). Standard exercise protocols have been used to cause the raise in pressure measured in the laboratories. This case suggests that CCS cannot be excluded without the specific sports activity being used to raise the intracompartmental pressure.     

Location of anterior knee pain affects load tolerance in isometric single leg knee extension

ObjectivesTo investigate relationships between load tolerance of single leg isometric knee extension and athlete reported knee pain location and severity during the single leg decline squat.DesignCross-sectional study.Methods175 college basketball athletes (99 women, 76 men) in Alberta, Canada participated at the start of the 2018–19 season. Knee pain location (dichotomized into focal/diffuse pain), and severity (numerical rating scale 0–10) were collected during the single leg decline squat. Athletes completed a standardized single leg isometric knee extension to determine load tolerance (defined by pain or reduced form). A quantile regression model was used to examine the association between load tolerance and pain location adjusting for sex, years played, body mass index and team.ResultsAthletes with diffuse pain had a significantly lower median load tolerance (?0.89 kg) than athletes without pain (95% confidence interval [?1.49, ?0.29]; p = 0.003). Athletes with focal pain tolerated similar median loads (?0.42 kg) to those without pain (95% confidence interval [?1.17, 0.33]; p = 0.26). Higher knee pain severity was associated with a non-linear but consistent reduction in load tolerance (p < 0.001).ConclusionsAthlete-reported knee pain location during the single leg decline squat influenced load tolerance to isometric knee extension. Athletes with focal pain tolerated similar isometric loads to their pain free teammates. Clinicians should consider load selection of isometric knee extension for athletes with diffuse pain given their lower load tolerance. Future research should consider reporting pain location in addition to pain severity to differentiate clinical presentations and response to exercise.     

Acute lower leg compartment syndrome.

Acute compartment syndromes in the lower leg are well recognized following major trauma. However, although rare, they may occur following seemingly minor sporting injury. A case of acute compartment syndrome, following a football game and affecting the peroneal or lateral compartment, is described, in which prompt diagnosis and treatment led to a satisfactory outcome. The diagnosis and surgical management of acute compartment syndromes are discussed. Early recognition and treatment are important in the prevention of long-term disability.     

The effect of gender on intramuscular pressure in patients with chronic exertional compartment syndrome of the lower leg

This study aimed to compare intramuscular pressure (IMP) in all four compartments of the lower leg between men and women in patients with suspected chronic exertional compartment syndrome (CECS), and to assess possible effects of gender in relation to covariation factors. A consecutive series of patients with exertional leg pain (n = 962, median age 27 years, 56.2% women) underwent IMP measurements between 2009 and 2019. The CECS diagnosis was confirmed (n = 491, 48% women) or ruled out (n = 471, 65% women) based on the patient's history, clinical examination, and IMP measurements. IMP values of the compartments were compared between genders. A multiple linear regression analysis was performed for IMP in the anterior and lateral compartments, where the number of patients was large enough to investigate the possible impact of other factors such as height, age, and duration of pain. Among those with a confirmed CECS diagnosis, one-minute post-exercise IMP was significantly lower in women than in men for all four muscle compartments: anterior (median [range] mmHg 44 [24–120] vs. 50 [24–130]), lateral (35 [20–89] vs. 40 [26–106]), deep posterior (31 [25–36] vs. 34 [24–53]), and superficial posterior (32 [27–39] vs. 37 [22–54]). In the multiple regression analysis, gender differences remained significant in the anterior compartment but not the lateral compartment, where only height remained a significant predictor of IMP. Gender should be considered when using cut-off values for IMP in diagnosing CECS, especially for the anterior compartment.     

Long-term results of fasciotomy of the anterior compartment in patients with exercise-induced pain in the lower leg

This prospective study aims to describe the results of fasciotomy in patients with exercise-induced pain in the lower leg with suspected (chronic) exertional compartment syndrome. The diagnosis of (chronic) exertional compartment syndrome was made if pain in the lateral side of the lower leg after a standard physical load was accompanied by elevated tissue pressures in the anterior muscle compartment. Tissue measurements were performed in 114 patients. In 56 patients (106 compartments) increased tissue pressure was found (> 50 mmHg measured immediately after exercise, or > 30 mmHg if the pressure before exercise > 20 mmHg, or if the pressure five minutes after exercise is still > 30 mmHg). Two years after fasciotomy, (remaining) complaints were evaluated on the basis of a questionnaire: 87 % of the patients had significant reduction in complaints. Patients who were not found to have increased tissue pressure were also asked to report developments through the questionnaire. In 18 patients a fasciotomy was performed on the basis of the typical history, despite normal or slightly increased intramuscular pressures. Twelve of these patients (24 compartments) were asymptomatic after surgery. Fasciotomy in patients with a (chronic) exercise-induced compartment syndrome in the anterior compartment of the lower leg, based on our criteria, gave a marked reduction in symptoms in 87 % of the patients. Further research has to be done for the minimum tissue pressures above which fasciotomy may be successful in terms of reducing complaints.     

Knee stability in orthotic knee braces

The ability of six commercially available orthotic knee braces to stabilize ligamentous injuries of the knee was evaluated using fresh cadaver specimens. Anterior, valgus, and rotational forces were applied to the intact knee, after the anterior cruciate and medial collateral ligaments were cut, and after application of the knee braces. Bony displacement was measured using half pins and an external fixator applied to the tibia and femur. There was a significant difference in brace performance, most likely due to differences in brace design. Of the six braces tested, the 3D 3-Way Brace provided the greatest knee stability.     

Evaluation of knee braces in Swedish ice hockey players.

In this retrospective investigation we have determined the rate and types of knee injuries among Swedish ice hockey players, and related these data to the use of knee braces. Thirty-seven of the originally selected 50 hockey teams (74%) of elite or first division calibre took part in the study, and 600 players answered a questionnaire. A total of 254 previous knee injuries sustained while playing hockey were reported by 243 players; tears of the medical collateral ligament (60%), meniscus (15%) or anterior cruciate ligament (12%) were the most commonly reported injuries. Prophylactic knee braces were worn by 138 (23%) of the players. Of these, 122 (88%) had earlier sustained a knee injury, and 16 had not. A total of 17 knee injuries had occurred while the players were wearing a brace. Six of these players had previously uninjured knees while 11 had repeat injury in a brace despite earlier successful rehabilitation or operation. The most common injury in braced knees was a tear of the medial collateral ligament. We conclude that the number of knee injuries is high among Swedish ice hockey players, and that the efficacy of functional knee braces to reduce knee injuries is questionable.     

Comparison of rehabilitative knee braces. A biomechanical investigation

A biomechanical comparison of eight popular commercially available rehabilitative knee braces was undertaken using a specially designed mechanical surrogate and computerized data acquisition system. Tests conducted included passive extension, valgus rotation, and anterior-posterior tibial translation. Most of the braces tested significantly reduced both translations and rotations compared to the unbraced limb under static test conditions. Braced versus braced performance varied and was found to depend upon a number of mechanical and design factors.     

Instrumented testing of functional knee braces

The ability of seven functional knee braces to control anterior tibial displacement in three severely lax ACL deficient knees using two instrumented testing devices was studied. Some braces were statistically shown to be much better in this regard than others, but not all data obtained was statistically significant. This material should aid one in determining which braces offer the greatest degree of control of anterior tibial displacement in patients with ACL insufficiency.     

Infrapatellar fat pad pressure and volume changes of the anterior compartment during knee motion: possible clinical consequences to the anterior knee pain syndrome

This biomechanical study was performed to measure tissue pressure in the infrapatellar fat pad and the volume changes of the anterior knee compartment during knee flexion–extension motion. Knee motion from 120° of flexion to full extension was simulated on ten fresh frozen human knee specimens (six from males, four from females, average age 44 years) using a hydraulic kinematic simulator (30, 40, and 50 Nm extension moment). Infrapatellar tissue pressure was measured using a closed cell sensor. Infrapatellar volume change in the anterior knee compartment was evaluated subsequent to removal of the fat pad using a water-filled bladder. We found a significant increase of the infrapatellar tissue pressure during knee flexion, at flexion angles of <20° and >100°. The average tissue pressure ranged from 343 (±223) mbar at 0° to 60 (±64) mbar at 60° of flexion. The smallest volume in the anterior knee compartment was measured at full extension and 120° of flexion, whereas the maximum volume was observed at 50° of flexion. In conclusion, the data suggest a biomechanical function of the infrapatellar fat pad at flexion angles of <20° and >100°, which suggests a role of the infrapatellar fat pad in stabilizing the patella in the extremes of knee motion.     

Analysis of pre- and postexercise compartment pressures in the medial compartment of the foot

Growing awareness of chronic exertional compartment syndrome of the foot has led to the need for site-specific analysis of normative resting and postexertional intracompartment pressures. Thirty-four asymptomatic athletes underwent pressure testing of the medial foot compartment with an intracompartmental pressure measurement apparatus. Pressure measurements were recorded before exercise and after 20 minutes of running. Mean resting intracompartment pressure was 7.7 mm Hg, whereas mean pressures 1 and 5 minutes after exercise were 19.1 mm Hg and 10.7 mm Hg, respectively. These data were then compared with data from compartment pressure studies performed in nine symptomatic subjects, each with a clinical history suggestive of chronic exertional compartment syndrome of the medial foot compartment. The results demonstrated normative compartment pressures of the medial foot compartment are comparable with previously measured pressures of the leg. This study shows that previously defined criteria for diagnosis of chronic exertional compartment syndrome of the leg may also be used for diagnosis of chronic exertional compartment syndrome of the foot.     

The effect of knee braces on lateral impact loading of the knee

Disruption of the medial supporting structures of the knee occurs commonly in contact sports such as American football and lacrosse. A limited number of clinical and laboratory studies currently document the effectiveness of bracing. The purpose of this project was to determine if commercially available bracing could be shown to produce objective evidence of medial stabilization of the knee. Our model involves the use of a cadaver lower extremity with a fixed foot and suspended femur with a free knee and a lateral impact load applied simulating a clipping injury. Force transducers were placed on the ACL and medial collateral ligament (MCL) and an electrogoniometer was attached to the extremity. The prophylactic braces studied had a limited capacity to protect the MCL from direct lateral stress with the knee in full extension. In flexion or with a change in direction of the load, the protective effect is greatly reduced. The functional braces had a capacity to limit abduction and rotational stresses on the MCL in flexion and extension.     

The use of knee braces during rehabilitation

This article has profiled the use of knee braces as an augmentation to the overall rehabilitation program following knee injury. It has also outlined other aspects of rehabilitation, the use of continuous passive motion devices, and other forms of exercises and training that, together with bracing, may enhance patient recovery. Continuous passive motion devices have been used for many different orthopedic problems with good success. Understanding the mechanics of how these devices move the knee and the forces that can be applied to the knee is helpful in deciding on their use after ligamentous reconstructions. Rehabilitation of the knee following surgery requires a good understanding of the effects that each exercise has on the knee and the reconstruction. Gradual progression of exercises to the knee following knee ligament reconstruction will not overstress healing tissues. Many different types of knee braces exist, and careful evaluation of them may enhance patient recovery.