The functional anatomy of the iliotibial band during flexion and extension of the knee: implications for understanding iliotibial band syndrome

Identifying iliotibial band graft length and incision site may minimise the potential risk of harming adjacent structures: A novel approach for surgeon guidance

PURPOSE

The Iliotibial band (ITB) is a fibrous thickening of the fascia lata originating at the iliac crest and inserting at Gerdy's tubercle on the lateral tibia. The ITB significantly contributes to lateral knee stabilisation. Due to its size, tensile strength and easy access, it is widely used in orthopaedic surgery as an autograft during reconstruction procedures. Although ITB harvesting may result in complications, such as reduced knee extension or hip flexion, no safety margins or guidelines have been proposed for the procedure. Our aim was to determine the maximal safe length of an ITB graft, that is, that does not harm the lateral collateral ligament (LCL), tensor fasciae latae (TFL), gluteus maximus (GM) or adjacent structures, and reduce the complication rate.

METHODS

The study included 50 lower limbs of 25 human cadavers, previously fixed in 10% formalin solution. The inclusion criterion was the lack of visible signs of surgical interventions in the study region. Forty lower limbs were included in the study: 16 female (mean age 83.1 ± 3.4 years) and 24 male (mean age 84.2 ± 6.8 years). Dissection was performed with a previously established protocol. Morphometric measurements were then obtained twice by two researchers.

RESULTS

The mean femur length was 404.8 mm [female (F) = 397.3 mm, male (M) = 409.9 mm, standard deviation (SD): F = 23.8 mm, M = 24.1 mm]. The mean ITB length was 318.9 mm (F = 309.4 mm, M = 325.2 mm, SD: F = 25.7 mm, M = 33.7 mm). Longer femurs were associated with longer ITB (p < 0.05). The mean distance from the insertion of the GM to the myofascial junction of TFL and ITB was 34.6 mm (F = 34.5 mm, M = 34.6 mm, SD: F = 3.2 mm, M = 3.3 mm). The longer femurs or ITBs demonstrated a greater distance from GM insertion to the myofascial junction of the TFL and ITB (p < 0.05).

CONCLUSION

ITB grafts longer than 21 cm may contribute to the greater risk of TFL rupture. Based on simple measurements of the femur length, the surgeon may assess approximate ITB length, and thus assess the length of the maximal graft length. Moreover, to avoid harming the LCL, the incision should be performed 5 cm proximal to the articular surface of the lateral femoral condyle or 13 mm proximal to the lateral femoral epicondyle. Such preparation and preoperative planning may greatly reduce the risk of complications during ITB harvesting, while performing, for instance, the over-the-top technique for anterior cruciate ligament reconstruction in skeletally immature patients.

LEVEL OF THE STUDY

Basic I.

Current iliotibial band syndrome alters patterns of running coordination in male and female runners, but not their levels of coordination variability

The aim of the present study was to compare the coordination patterns and levels of coordination variability of healthy and injured runners with iliotibial band syndrome (ITBS). Sixty runners divided into four groups (15 healthy males, 15 healthy females, 15 males with ITBS and 15 females with ITBS) ran at a steady and freely chosen pace on an over-ground track, and their coordination patterns of the lower limbs were calculated during 10 running stances using the vector coding technique. Both male and female runners with ITBS showed a greater dominance of the pelvis segment and the anti-phase patterns in the frontal plane thigh-pelvis coupling (p = 0.001, η2 = 0.36). In addition, injured female runners showed a greater hip adduction dominance, whereas injured males presented a greater anti-phase pattern in the transverse plane-frontal plane hip coupling (p = 0.003, η2 = 0.08). The levels of coordination variability during running stance did not change between ITBS injured and healthy runners in any of the couplings. Currently injured runners with ITBS appeared to present altered coordination patterns on the hip couplings that were partly dependent on gender but did not lead to changes in the coordination variability levels.

Surgical Treatment and Outcomes for Gluteal Tendon Tears

PURPOSE OF REVIEW

Gluteus medius and minimus tears, or hip abductor tendon tears, are increasingly identified as a source of lateral hip pain. Once underappreciated and undertreated, they are now recognized as a cause of greater trochanteric pain syndrome and a pathology amenable to both nonoperative and operative modalities. This review summarizes relevant anatomy, clinical presentation, and treatment options for gluteus medius tears, focusing on surgical options.

RECENT FINDINGS

When surgical intervention is indicated, repair, reconstruction, or tendon transfer may be considered. Open and endoscopic repair techniques demonstrate similar outcomes with improvements in patient-reported outcomes and low complication and retear rates for both partial and full thickness tears. Variations in fixation construct and graft augmentations have been described, though clinical evidence remains limited to support specific techniques. Gluteus maximus transfer via open approach is a salvage option for the severely atrophied, retracted, or revision gluteus tendon; however, persistent limitations in abduction strength and gait abnormalities are common. Emerging evidence continues to evolve our understanding of surgical decision-making for gluteus tendon tears. The current literature supports either open or endoscopic repair techniques and open tendon transfer as a salvAage option. Further study is needed to determine the optimal fixation construct, the role of graft augmentation, and patient-related factors that influence postoperative outcomes.

Outcome of lateral retinacular nerve transection combined with release for recalcitrant iliotibial band friction syndrome

In this retrospective study, a technique consisting in neurolysis of the lateral retinacular nerve combined with a partial release through elliptic excision of the iliotibial band (ITB) is evaluated for efficacy in recalcitrant ITB friction syndrome and compared with results from other techniques reported in literature. From April 2014 to December 2017, 21 patients suffering from recalcitrant ITB friction syndrome were surgically treated with the aforementioned technique. 15 patients (15 knees) were available for a written retrospective reassessment after completion of a follow-up period of at least 12 months. Residual pain was scored using the Visual Analogue Scale (VAS). The functional outcome was evaluated by two patient reported outcome measurement scales (PROMs), the Lysholm and the International Knee Documentation Committee (IKDC) score. Return to sport was analysed by duration of the inactivity period as well as by the Tegner score. Overall satisfaction was evaluated using a modified Boyden scale. At final follow-up of one year, the performed intervention resulted in a pain reduction (VAS 4.2 (1-8) to 1.4 (0-6)) and improved knee function (Lysholm 59.53 to 87.73, IKDC 75) with return to sport (Tegner 4.3 to 5.4) after a median of 23.8 weeks (6 to 52). Twelve patients reported good or excellent results (80%) at final follow-up, and 12 patients (80%) would undergo surgery again, if necessary. The treatment of recalcitrant ITB friction syndrome by combining neurectomy of the lateral retinacular nerve with elliptic excision of the ITB resulted in good to excellent results in 80% of treated cases with return to sport in 93%.

The effects of alteration in muscle activation on the iliotibial band during an exhaustive run

PURPOSE

Long exhausted running causes pain at the lateral femoral epicondyle for some runners. The pain has been revealed to be related to the behavior of the iliotibial band (ITB) during running. The purpose of this study is to examine the effects of in-series musculature on the behavior of the ITB in healthy participants during an exhaustive run.

METHODS

Twenty-five healthy participants (15 males, 10 females) were recruited in the current study. All participants performed a 30-minute exhaustive run at a self-selected speed with laboratory-provided footwear. Muscle activities of ITB-related muscles including tensor fascia latae (TFL), gluteus maximus (Gmax), gluteus medius (Gmed), biceps femoris (BF), and vastus lateralis (VL) were recorded using surface electromyography (EMG).

RESULTS

Maximum amplitudes at the initial stage (the first minute), the mid stage (the 15-minute), and the end stage (the 30-minute) were compared during the exhaustive running. Significant decreases (p < 0.05) were observed in the maximum amplitudes of the TFL, Gmax, Gmed, and BF at the mid (decreased by ~ 15%) and end (decreased by ~ 30%) stages compared to the initial stage. The onset and the offset remained unaltered during the running (p ≥ 0.05).

CONCLUSION

The behavior of the healthy ITB might be altered due to the activities of the in-series musculature. Excessive compression forces might be applied to the lateral femoral epicondyle from the ITB to provide stability for the knee joint during an exhaustive run. The findings could provide a basic understanding of the behavior of healthy ITB.

Iliotibial band friction syndrome after knee cementoplasty: a case report

Iliotibial band pathologies can result in lateral knee pain. These are commonly seen in runners and cyclists. Lateral knee pain following knee arthroplasty can be due to distal iliotibial band enthesopathy or impingement by the femoral component. Cementoplasty is a common procedure performed during treatment of osseous lesions. We describe a case of ITB friction syndrome due to small focus of cement following cementoplasty for GCT (giant cell tumour).

Stretching and Releasing of Iliotibial Band Complex in Patients with Iliotibial Band Syndrome: A Narrative Review

Iliotibial band syndrome (ITBS) is one of the most common overuse syndromes causing knee pain; it is especially prevalent in runners and also common in cyclists, rowers, and field athletes, with occasional cases occurring in non-athletes too. ITBS symptoms can negatively affect not only knee function, but also mental and physical aspects of health-related quality of life. Although various conservative treatment options have been investigated and discussed, there is still no consensus on a standard of care for ITBS. Moreover, the literature on the etiology and risk factors of ITBS, which could help in selecting appropriate treatment methods, is conflicting and inconclusive. The role of individual treatment modalities such as stretching and releasing techniques has not been extensively studied and remains unclear. In this article, we will critically review the available evidence for the benefits of ITB stretching and "release" methods in the treatment of ITBS. In addition to the direct evidence (clinical studies examining the effects of ITB stretching and other methods that purportedly stretch or "release" the ITB), we present several additional lines of reasoning that discuss the rationale for ITB stretching/releasing in terms of the etiology of ITBS, the mechanical properties and behavior of the ITB, and the risk factors for ITBS development. We conclude that the current literature provides some evidence for the inclusion of stretching or other "release" methods in the early rehabilitation of ITBS. Long-term interventions typically include ITB stretching; however, it remains unclear to what extent stretching within a multimodal treatment actually contributes to resolving the symptoms. At the same time, there is no direct evidence to suggest that stretching and "release" methods have any negative effects.

Effects of Running Speeds and Exhaustion on Iliotibial Band Strain during Running

Background: Iliotibial band syndrome (ITBS) is one of the most prevalent overuse injuries in runners. The strain rate in the iliotibial band (ITB) has been theorized to be the primary causative factor in the development of ITBS. Running speed and exhaustion might lead to an alteration in the biomechanics that influence the strain rate in the iliotibial band. Objectives: To identify how exhaustion states and running speeds affect the ITB strain and strain rate. Methods: A total of 26 healthy runners (including 16 males and 10 females) ran at a normal preferred speed and a fast speed. Then, participants performed a 30 min exhaustive treadmill run at a self-selected speed. Afterward, participants were required to run at similar speeds to those of the pre-exhaustion state. Results: Both the exhaustion and running speeds were revealed to have significant influences on the ITB strain rate. After exhaustion, an increase of approximately 3% in the ITB strain rate was observed for both the normal speed (p = 0.001) and the fast speed (p = 0.008). Additionally, a rapid increase in the running speed could lead to an increase in the ITB strain rate for both the pre- (9.71%, p = 0.000) and post-exhaustion (9.87%, p = 0.000) states. Conclusions: It should be noted that an exhaustion state could lead to an increase in the ITB strain rate. In addition, a rapid increase in running speed might cause a higher ITB strain rate, which is proposed to be the primary cause of ITBS. The risk of injury should also be considered due to the rapid increase in the training load involved. Running at a normal speed in a non-exhaustive state might be beneficial for the prevention and treatment of ITBS.

A new marker cluster anchored to the iliotibial band improves tracking of hip and thigh axial rotations

Tracking hip and thigh axial rotation has limited accuracy due to the large soft tissue artifact. We proposed a tracking-markers cluster anchored to the prominent distal part of the iliotibial band (ITB) to improve thigh tracking. We investigated if the ITB cluster improves accuracy compared with a traditionally used thigh cluster. We also compared the hip kinematics obtained with these clusters during walking and step-down. Hip and thigh kinematics were assessed during a task of active internal-external rotation with the knee extended, in which the shank rotation is a reference due to smaller soft-tissue artifact. Errors of the hip and thigh axial rotations obtained with the thigh clusters compared to the shank cluster were computed as root-mean-square errors, which were compared by paired t-tests. The angular waveforms of this task were compared using the statistical parametric mapping (SPM). Additionally, the hip waveforms in all planes obtained with the thigh clusters were compared during walking and step-down, using Coefficients of Multiple Correlation (CMC) and SPM (α = 0.05 for all analyses). The ITB cluster errors were approximately 25 % smaller than the traditional cluster error (p < 0.001). ITB cluster errors were smaller at external rotation angles while the traditional cluster error was smaller at internal rotation angles (p < 0.001), although the clusters' waveforms were not significantly different (p ≥ 0.005). During walking and step-down, both clusters provided similar hip kinematics (CMC ≥ 0.75), but differences were observed in parts of the cycles (p ≤ 0.04). The findings suggest that the ITB cluster may be used in studies focused on hip axial rotation.

The influence of iliotibial tract thickness on clinical outcomes in women with patellofemoral pain

BACKGROUND

The assessment of iliotibial tract thickness by ultrasonography may help identify a key, previously unexplored factor that may contribute directly to the homeostasis imbalance of the femoropatellar joint in people with patellofemoral pain (PFP).

OBJECTIVES

To compare the iliotibial tract thickness of people with PFP and asymptomatic people; and to correlate the iliotibial tract thickness with self-reported pain and function of people with PFP.

METHODS

Eighty women, separated into two groups: PFP group (n = 40) and control group consisting of asymptomatic participants (CG; n = 40). The participants answered the Anterior Knee Pain Scale (AKPS) questionnaire, to identify the self-reported knee function; they evaluated the pain in millimeters by the Visual Analog Scale for pain (VAS). For the imaging evaluation, an ultrasound was used, with a linear transducer at the distal portion of the iliotibial tract (coronal plane), with the participants positioned in dorsal decubitus, with 20° of knee flexion. The iliotibial band was visualized in its long axis, and three sequential images were recorded between the lateral femoral condyle and the lateral tibial condyle. The measurements were normalized and correlated.

RESULTS

The groups had no differences (P > 0.001) between participants for: age/weight/height/IMC. Participants in the PFP group had moderate levels of pain (58 + 2.1 mm), considerable self-reported functional limitation (d = 3.05) and greater iliotibial tract thickness compared with the CG (d = 2.41).

CONCLUSION

The iliotibial tract of women diagnosed with PFP have greater thickness compared with asymptomatic women. There was no association between iliotibial tract thickness and subjective measures of pain and function.

Intraobserver Assessment of Shear Wave Elastography in Tensor Fasciae Latae and Gluteus Maximus Muscle: The Importance of the Hip Abductor Muscles in Runners Knee Compared to Healthy Controls

Background: Iliotibial band syndrome (ITBS) represents one of the most common running related injuries. The pathophysiology is postulated to be caused by excessive ITB tension, impingement and irritation of soft tissues at the lateral femoral epicondyle. However, direct evidence has yet to be found and the multifactorial etiology is under discussion. The purpose was to evaluate stiffness of ITB, gluteus maximus (GM) and tensor fasciae latae (TFL) muscles using shear wave elastography (SWE). Methods: In 14 patients with clinically verified ITBS and 14 healthy controls, three SWE measurements each of ITB, GM and TFL in both legs was performed to determine measurement reliability and between-group and -leg differences. Results: The mean value of ITB was 12.8 m/s with ICC of 0.76, whereas the values measured in the GM were 3.02 m/s with an ICC of 0.87. No statistically significant difference in controls compared to patients were found (p = 0.62). The mean value of TFL was 5.42 m/s in healthy participants, compared to 3.89 m/s patients with an ICC of 0.98 (p = 0.002). Conclusion: Although SWE showed no difference in ITB stiffness, significant differences for TFL muscle stiffness in runner’s knee was found, suggesting that the hip abductor muscles might play a bigger role in the pathophysiology of ITBS. We aimed to implement baseline values for stiffness assessments and prove reliability for further prospective studies of SWE in runner’s knee.

Challenges of total knee arthroplasty in osteogenesis imperfecta: case report and literature review

The majority of adults with mild osteogenesis imperfecta report significant functional impairment due to musculoskeletal concerns. Knee osteoarthritis is common in these patients. Although total knee arthroplasty has become a highly efficient surgical technique for osteoarthritis, this procedure remains uncommon in patients with osteogenesis imperfecta. This current case report describes the important clinical aspects of osteogenesis imperfecta that must be considered during the planning and performance of a total knee replacement. A 62-year-old female patient with a history of osteogenesis imperfecta suffered from severe osteoarthritis of the knee with valgus deformity. Two years after posterior stabilized total knee arthroplasty, her Hospital for Special Surgery knee score had improved from preoperative 53 points to 85 points at the final follow-up. The current case report describes the crucial technical aspects of a successful total knee replacement in this uncommon scenario. Underlying deformities and concomitant pathologies constitute specific surgical challenges. Special care should be taken to protect the patient from potential complications.

Distinct displacement of the superficial and deep fascial layers of the iliotibial band during a weight shift task in runners: An exploratory study

Motion of the fascial layers of the iliotibial band (ITB), as a reinforcement of the deep fascia lata, is likely to be relevant for its function and mechanical behaviour. This exploratory study aimed to evaluate the ITB fascial layers displacement during a weight shift task. Thirteen pain-free runners performed a 6-second standing weight shift task. B-mode ultrasound imaging using an automated fascicle tracking algorithm was used to measure proximal and distal displacement of superficial and deep ITB layers at the middle region. To study the potential contributors to individual variation of fascial motion, we recorded the activity of five hip/thigh muscles with electromyography (EMG), thigh/pelvis/trunk position with accelerometers, and centre of pressure with a force plate. Linear regressions estimated the relationship between displacement of fascial layers and hip/trunk angles. Independent t-tests or Fisher's exact tests compared EMG and movement-related parameters between participants who demonstrated motion of the fascia in the proximal and distal directions. Thickness of the ITB and the loose connective tissue between its layers were calculated. Proximal displacement was observed in six (-4.1 ± 1.9 mm [superficial]) and two (-6.2 ± 2.0 mm [deep]) participants. Distal displacement was observed for seven participants for each layer (3.1 ± 1.1 mm [superficial]; 3.6 ± 1.3 mm [deep]). Four participants did not show displacement of the deep layer. Trunk lateral flexion and gluteus medius muscle activity were determinants of proximal motion of the superficial layer. Loose connective tissue was thinner in participants without displacement of the deep layer. Displacement of the ITB fascial layers varies between individuals. Variation related to differences in joint movements and muscle activity. This study highlights the complex interaction between fascia and movement.

The Iliotibial Band: A Complex Structure with Versatile Functions

The development of a pronounced iliotibial band (ITB) is an anatomically distinct evolution of humans. The mechanical behaviour of this “new” structure is still poorly understood and hotly debated in current literature. Iliotibial band syndrome (ITBS) is one of the leading causes of lateral knee pain injuries in runners. We currently lack a comprehensive understanding of the healthy behaviour of the ITB, and this is necessary prior to further investigating the aetiology of pathologies like ITBS. Therefore, the purpose of this narrative review was to collate the anatomical, biomechanical and clinical literature to understand how the mechanical function of the ITB is influenced by anatomical variation, posture and muscle activation. The complexity of understanding the mechanical function of the ITB is due, in part, to the presence of its two in-series muscles: gluteus maximus (GMAX) and tensor fascia latae (TFL). At present, we lack a fundamental understanding of how GMAX and TFL transmit force through the ITB and what mechanical role the ITB plays for movements like walking or running. While there is a range of proposed ITBS treatment strategies, robust evidence for effective treatments is still lacking. Interventions that directly target the running biomechanics suspected to increase either ITB strain or compression of lateral knee structures may have promise, but clinical randomised controlled trials are still required.

Conservative treatment of iliotibial band syndrome in runners: Are we targeting the right goals?

OBJECTIVE

Iliotibial band syndrome (ITBS) is presumably caused by excessive tension in the iliotibial band (ITB) leading to compression and inflammation of tissues lying beneath it. Usually managed conservatively, there is a lack of scientific evidence supporting the treatment recommendations, and high symptom recurrence rates cast doubt on their causal effectiveness. This review discusses the influence of common physiotherapeutic measures on risk factors contributing to tissue compression beneath the ITB.

METHODS

The potential pathogenic factors are presented on the basis of a simple biomechanical model showing the forces acting on the lateral aspect of the knee. Existent literature on the most commonly prescribed physiotherapeutic interventions is critically discussed against the background of this model. Practical recommendations for the optimization of physiotherapy are derived.

RESULTS

According to biomechanical considerations, ITBS may be promoted by anatomical predisposition, joint malalignments, aberrant activation of inserting muscles as well as excessive ITB stiffness. Hip abductor strengthening may correct excessive hip adduction but also increase ITB strain. Intermittent stretching interventions are unlikely to change the ITB's length or mechanical properties. Running retraining is a promising yet understudied intervention.

CONCLUSIONS

High-quality research directly testing different physiotherapeutic treatment approaches in randomized controlled trials is needed.

Palpation of the lateral bands of the extensor apparatus of the fingers. Anatomy of a neglected clinical finding

This study aimed to determine by ultrasonography, and cadaveric dissection, whether the firm cords felt by palpation at the sides of the proximal phalanx (PP), actively flexing, and extending the proximal interphalangeal (PIP) joint while keeping the metacarpophalangeal (MCP) joint extended are the lateral bands (LBs) of the extensor apparatus. If so, palpation of the LBs could help evaluate hand conditions that impact the digits' intrinsic muscles. To this end, the PP of the middle and ring fingers of the dominant hand of seven subjects were studied by palpation on both sides. Ultrasonography (US) was performed with a hockey-stick transducer placed on the ulnar side. Five cadaveric hands were dissected, exposing the dorsal extensor apparatus. On palpation, a firm cord was consistently felt at the PP's sides in all subjects. These cords moved widely forward on PIP flexion and backward with PIP extension. By US scanning, the cords corresponded to the LBs. However, the forward movement had only a median of 1.8 mm (range 0.7-3 mm) in the middle finger and a median of 1.1 mm (range 0.3-2.7 mm) in the ring finger compared with an estimated 5-10 mm upon palpation. Cadaveric dissection confirmed the forward movement of the LBs in PIP flexion. We concluded that the firm cords felt at the PP sides are the LBs of the extensor apparatus. We confirmed their movement with the active flexion/extension of the PIP joint. Comparing the wide palpatory and the meager US motion, a haptic illusion of motion may be present.

Current Clinical Concepts: Synthesizing the Available Evidence for Improved Clinical Outcomes in Iliotibial Band Impingement Syndrome

The current paradigm of insidious lateral knee pain involving the iliotibial band (ITB) in repetitive knee-flexion activities has been termed ITB friction syndrome since 1975. The original model for ITB pain was based on a limited or incorrect understanding of the relevant anatomy, biomechanics, and tissue science, which gradually led to a plethora of frustrating and ineffective interventional strategies. Mounting evidence from arthroscopic, cadaveric, and biomechanical studies, as well as from diagnostic imaging and histologic reports, has helped deconstruct this long-held paradigm for ITB-related pathology and treatment. By outlining the historical paradigm for our understanding of ITB pain and gathering newer evidence through extensive research, I will synthesize the available data in this clinical update to present an updated, more informed model for understanding insidious-onset ITB-related pathology and treating patients. The result is called ITB impingement syndrome.

A quantitative MRI investigation of the association between iliotibial band syndrome and patellofemoral malalignment

Background

The iliotibial band (ITB) has a wide patellar insertion that provides lateral restraint to the patella and maintains the patellofemoral joint's stability. There has been limited investigation into the relationship between patellofemoral malalignment and iliotibial band syndrome (ITBS).

Methods

We retrospectively analyzed 47 knees with ITBS by retrieving magnetic resonance imaging (MRI) data collected over an approximately 6-year period from our database. The Insall-Salvati ratio, lateral patellofemoral angle (LPA), lateral patellar tilt (LPT), lateral trochlear length (LTL), angle of the non-weight-bearing facet of the lateral femoral condyle (nwb-LFCA), and the ITB-lateral femoral condyle (IT-LFC) distance were measured on MR images. The knees of 47 age- and gender-matched subjects were enrolled as the normal group.

Results

In the ITBS group, over one third (34%, 16/47) of knees had abnormal patellofemoral measurements, including 8 (17%, 8/47) knees with patellar alta, 11 (23.4%, 11/47) knees with an abnormally decreased LPA, and 5 (10.6%, 5/47) knees with an abnormally increased LPT indicating lateral patellar tilt. Moreover, 8 knees had simultaneous combinations of two or three abnormality parameters, and 8 (17%, 8/47) knees presented with superolateral Hoffa's fat pad edema. The Insall-Salvati ratio, LPT, and nwb-LFCA in the ITBS group were significantly higher than those in the normal group (P=0.001, P<0.001, and P<0.001, respectively); the LPA and IT-LFC distances in the ITBS group were significantly lower (P=0.003, P<0.001, respectively) than those in the normal group. There were mild to moderate correlations between the MRI parameters and ITBS (P=0.006, P<0.001, respectively).

Conclusions

This study confirmed that a higher position or lateral tilt of the patella and a steeper morphology of the anterior part of the lateral femoral condyle were associated with the development of ITBS, which is helpful in understanding and further exploring the mechanism of ITBS.

The Immediate Effects of Foam Rolling and Stretching on Iliotibial Band Stiffness: A Randomized Controlled Trial

BACKGROUND

Iliotibial Band Syndrome (ITBS) is a common clinical condition likely caused by abnormal compressive forces to the iliotibial band (ITB). Stretching interventions are common in ITBS treatment and may predominantly affect tensor fascia latae (TFL). Another ITBS treatment is foam rolling, which may more directly affect the ITB. Shear wave ultrasound elastography (SWUE) measures real-time soft tissue stiffness, allowing tissue changes to be measured and compared.

PURPOSE

To examine effects of foam rolling and iliotibial complex stretching on ITB stiffness at 0˚ and 10˚ of hip adduction and hip adduction passive range of motion (PROM).

STUDY DESIGN

Randomized controlled trial.

METHODS

Data from 11 males (age = 30.5 ± 9.0 years, Body Mass Index (BMI) = 27.8 ± 4.0) and 19 females (age = 23.5 ± 4.9, BMI = 23.2 ± 2.1) were analyzed for this study. Subjects were randomly assigned to one of three groups: control, stretching, and foam rolling. Shear wave ultrasound elastography measurements included ITB Young's modulus at the mid-thigh, the distal femur and the TFL muscle belly. ITB-to-femur depth was measured at mid-thigh level. Hip adduction PROM was measured from digital images taken during the movement.

RESULTS

No significant interactions or main effects were found for group or time differences in ITB Young's modulus at the three measured locations. The ITB stiffness at the mid-thigh and distal femur increased with 10° adduction, but TFL stiffness did not increase. A main effect for adduction PROM was observed, where PROM increased 0.8˚ post-treatment (p = 0.02).

CONCLUSION

A single episode of stretching and foam rolling does not affect short-term ITB stiffness. The lack of ITB stiffness changes may be from an inadequate intervention stimulus or indicate that the interventions have no impact on ITB stiffness.

LEVELS OF EVIDENCE

1b.

Exploration of shear wave elastography measures of the iliotibial band during different tasks in pain-free runners

OBJECTIVES

To determine whether shear wave velocity (SWV) of the iliotibial band (ITB): i) increases with active and passive static tasks, and a dynamic task, ii) differs between ITB regions, iii) changes after exposure to running. Additionally, it aimed to determine the between-day reliability.

DESIGN

Case series & test-retest.

SETTING

Human movement unit laboratory.

PARTICIPANTS

Fifteen runners.

MAIN OUTCOME MEASURES

SWV was measured unilaterally in three regions of the ITB (proximal, middle and distal), during six tasks: rest and contraction (pre- and post-running), modified Ober test, standing, pelvic drop, and weight shift.

RESULTS

Compared to rest, SWV was higher during contraction and Ober test in the distal and middle regions, and higher for the middle region in standing and pelvic drop. No differences were found between regions. A tendency of decreased SWV was observed after running. Compared to the start of the dynamic task, SWV was greater at the end of the movement. Reliability was moderate-to-good for the middle region in the standing tasks (ICCs = 0.68 to 0.84).

CONCLUSION

SVW of the ITB was higher under passive or active tension. Comparisons between tasks/regions need to be considered in light of the small sample size and poor repeatability of some regions/conditions.

Influence of transducer orientation on shear wave velocity measurements of the iliotibial band

Tissue anisotropy influences estimation of mechanical properties of connective tissues, such as the iliotibial band (ITB). This study investigated the influence of ultrasound transducer rotation and tilt on shear wave velocity (SWV, an index of stiffness) measurements of the ITB and the intra-rater repeatability of SWV measurements in the longitudinal direction. SWV was measured unilaterally (dominant limb) using ultrasound shear wave elastography in the middle region of the ITB in supine at rest (20-25° knee flexion) in ten healthy volunteers (4 females). A 3-dimensional video system provided real-time feedback of probe orientation with respect to the thigh. Measurements were made at 10° increments of probe rotation, from longitudinal to transverse alignment relative to the approximate direction of ITB fibres, and 5-10° tilts about the longitudinal and sideways axes of the transducer. One-way repeated measures ANOVA compared SWV between angles and tilts. Intraclass correlation coefficients (ICCs) and standard error of measurement (SEM) were used to calculate repeatability for two to five (longitudinal only) repetitions. SWV was greatest when the transducer was aligned to ITB fibres (longitudinal: 10.5 ± 1.7 m/s) and lowest when perpendicular (transverse: 5.8 ± 2.4 m/s). Compared to longitudinal alignment, SWV decreased significantly (p < 0.01) when the transducer was rotated 20° or more. Tilted measurements did not differ between angles. Intra-rater repeatability was excellent with the average of two measurements (ICC = 0.99, 95% CI 0.95, 0.99; SEM = 0.31 m/s). These findings show that SWV changes with orientation relative to fibre direction. Transducer orientation requires careful control to ensure comparable measures.

Iliotibial band enthesopathy: an unusual cause of lateral knee pain post total knee replacement

Iliotibial band (ITB) pathology is one of the main causes of lateral knee pain. The enthesopathy of the ITB at its insertion post total knee replacement (TKR) is a rare cause of lateral knee pain. We describe a series of cases of ITB enthesopathy with sonographic findings and management.

Surgical interventions for external snapping hip syndrome

PURPOSE

Snapping hip is a common clinical condition, characterized by an audible or palpable snap of the hip joint. When the snap is perceived at the lateral side of the hip, this condition is known as external snapping hip or lateral coxa saltans, which is usually asymptomatic. Snapping hip syndrome (SHS) refers to a painful snap, which is more common in athletes who require increased hip range of motion. The aim of this article is to review the most common endoscopic techniques for the treatment of ESHS, as well as their results and limitations.

METHODS

This is a review of the current literature of endoscopic surgical procedures and of the results of the treatment of external snapping hip syndrome.

RESULTS

The pathogenesis of SHS is mechanical. The initial treatment attempt is conservative, and usually provides good results. Patients who do not respond to conservative management are candidate for surgery. The endoscopic release of the ilio-tibial band or the endoscopic release of the femoral insertion of the gluteus maximum tendon is the most popular technique.

CONCLUSION

Endoscopic techniques provide fewer complications compared to open surgery, a lower recurrence rate and good clinical outcomes. More comparative studies with a longer follow-up are required to adequate evaluate the full role of endoscopic techniques in periarticular hip surgery.

LEVEL OF EVIDENCE

Level V.

ILIOTIBIAL BAND SYNDROME IN CYCLING: A COMBINED EXPERIMENTAL-SIMULATION APPROACH FOR ASSESSING THE EFFECT OF SADDLE SETBACK

BACKGROUND

Despite abundant literature, the treatment of iliotibial band syndrome (ITBS) in cyclists remains complicated as it lacks evidence-based recommendations.

PURPOSE

The aim of this study was to develop a musculoskeletal modelling approach that investigates three potential biomechanical determinants of ITBS (strain, strain rate and compression force) and to use this approach to investigate the effect of saddle setback.

DESIGN

Cross-sectional.

METHODS

An existing 3D lower-body musculoskeletal model was adapted to cycling and to the computation of three putative pathomechanisms responsible for ITBS: ITB strain, ITB strain rate, and compression force between ITB and the lateral femoral epicondyle (LFE). Lower limb kinematics recorded from ten well-trained healthy cyclists served as input data of the model. Cyclists pedalled at a steady state (90rpm and 200W) on an ergometer, and three different saddle setback conditions were tested. The theoretical combined influence of hip and knee joint angles on ITBS was investigated and analysed through the lens of individual pedalling technique.

RESULTS

ITB-LFE compression force was the only parameter significantly affected by saddle setback and supports the hypothesis that compression force is likely to be a determinant factor in ITBS etiology. Furthermore, results showed that ITB-LFE compression force increases in individuals whose pedalling technique exacerbates hip extension-adduction and/or knee extension-internal rotation.

CONCLUSION

This approach has the potential to be advantageously implemented as an additional tool to help diagnose/correct potentially harmful sport techniques and optimize equipment setup/design.

LEVEL OF EVIDENCE

3b.

Chronic hip pain in adults: Current knowledge and future prospective

Chronic hip pain is distressing to the patient as it not only impairs the daily activities of life but also affects the quality of life. Chronic hip pain is difficult to diagnose as patients often present with associated chronic lumbar spine and/or knee joint pain. Moreover, nonorthopaedic causes may also present as chronic hip pain. The accurate diagnosis of chronic hip pain starts with a detailed history of the patient and thorough knowledge of anatomy of the hip joint. Various physical tests are performed to look for the causes of hip pain and investigations to confirm the diagnosis. Management of chronic hip pain should be mechanistic-based multimodal therapy targeting the pain pathway. This narrative review will describe relevant anatomy, causes, assessment, investigation, and management of chronic hip pain. The focus will be on current evidence-based management of hip osteoarthritis, greater trochanteric pain syndrome, meralgia paresthetica, and piriformis syndrome. Recently, there is emphasis on the role of ultrasound in interventional pain procedures. The use of fluoroscopic-guided radiofrequency in periarticular branches of hip joint has reported to provide pain relief of up to 36 months. However, the current evidence for use of platelet-rich plasma in chronic hip osteoarthritis pain is inconclusive. Further research is required in the management of chronic hip pain regarding comparison of fluoroscopic- and ultrasound-guided procedures, role of platelet-rich plasma, and radiofrequency procedures with long-term follow-up of patients.

The influence of different sample preparation on mechanical properties of human iliotibial tract

In the run-up to biomechanical testing, fresh human tissue samples are often frozen in order to inhibit initial decomposition processes and to achieve a temporal independence of tissue acquisition from biomechanical testing. The aim of this study was to compare the mechanical properties of fresh tissue samples of the human iliotibial tract (IT) to fresh-frozen samples taken from the same IT and those modified with different concentrations of Dimethylsulfoxide (DMSO) prior to freezing. All samples were partial plastinated and destructive tensile tests were conducted with a uniaxial tensile test setup. A plastination technique already established in the laboratory was modified to improve the clamping behaviour of the samples. Material failure was caused by a gradual rupture of the load-bearing collagen fibre bundles. Contrary to our expectations, no significant difference was found between the tensile strength of fresh and fresh frozen specimens. The addition of 1 wt% DMSO did not increase the tensile strength compared to fresh-frozen samples; an addition of 10 wt% DMSO even resulted in a decrease. Based on our findings, the use of simple fresh-frozen specimens to determine the tensile strength is viable; however fresh specimens should be used to generate a complete property profile.

Site dependent elastic property of human iliotibial band and the effect of hip and knee joint angle configuration

The iliotibial band (ITB) is the lateral thickening of the fascia lata. The ITB has been extensively studied for its relevance to injury, but not much is known about its elastic properties. We aimed to investigate the site- and joint angle-dependence of ITB elasticity. We tested twelve healthy males (22-30 years; in vivo) and twelve male cadavers (69-93 years; cadaver). The Young's modulus of the ITB was measured in the longitudinal direction at five sites (over the proximal, middle, and distal bellies of the vastus lateralis (VL), superior border of the patella, and between femur and tibia) of the right limb, by ultrasound shear wave elastography (in vivo) and the tensile test (cadaver). Joint angle-dependence was also studied for nine different positions (knee angles at 0, 25, 90˚ x hip angles at 0, 40, 90˚) (in vivo). Over VL, the ITB was more compliant at the distal (17.6-190.1 kPa; in vivo, 219.4 ± 68.8 MPa; cadaver, mean ± SD) than other sites (24.2-221.4 kPa, 337.9-362.7 MPa). The ITB at the superior border of the patella and between femur and tibia was stiffer in vivo (31.8-271.8 and 50.9-208.8 kPa), while it was more compliant in cadavers (113.4 ± 63.7 and 130.4 ± 73.7 MPa), compared to other sites. The ITB became stiffer associated with increasing hip extension angle and knee flexion angle, and the hip remarkably affecting the values regardless of site (in vivo). Our findings have clinical significance with respect to the site- and joint angle-dependence of ITB-related overuse injury.

Strain Assessment of Deep Fascia of the Thigh During Leg Movement: An in situ Study

Fascia is a fibrous connective tissue present all over the body. At the lower limb level, the deep fascia that is overlying muscles of the outer thigh and sheathing them (fascia lata) is involved in various pathologies. However, the understanding and quantification of the mechanisms involved in these sheathing effects are still unclear. The aim of this study is to observe and quantify the strain field of the fascia lata, including the iliotibial tract (ITT), during a passive movement of the knee. Three fresh postmortem human subjects were studied. To measure hip and knee angles during knee flexion-extension, passive movements from 0° to around 120° were recorded with a motion analysis system and strain fields of the fascia were acquired using digital image correlation. Strains were computed for three areas of the fascia lata: anterior fascia, lateral fascia, and ITT. Mean principal strains showed different strain mechanisms depending on location on the fascia and knee angle. For the ITT, two strain mechanisms were observed depending on knee movement: compression is observed when the knee is extended relative to the reference position of 47°, however, tension and pure shear can be observed when the knee is flexed. For the anterior and lateral fascia, in most cases, minor strain is higher than major strain in absolute value, suggesting high tissue compression probably due to microstructural fiber rearrangements. This in situ study is the first attempt to quantify the superficial strain field of fascia lata during passive leg movement. The study presents some limitations but provides a step in understanding strain mechanism of the fascia lata during passive knee movement.

Ultrasound of iliotibial band syndrome

Iliotibial band syndrome or friction syndrome is an overuse disorder of the lateral knee. It is commonly reported in athletes, such as runners and cyclists, and refers to pain related to physical activity. The diagnosis is based on clinical history and physical assessment. Imaging, including ultrasound, is mainly performed in recurrent or refractory cases. The purpose of this paper is to review the etiology, diagnosis, and therapy of iliotibial band syndrome with a focus on ultrasound imaging and ultrasound-guided treatment. Ultrasound findings include soft-tissue edematous swelling or discrete fluid collection, suggestive of bursitis, between the iliotibial band and the lateral femoral epicondyle. The thickening of the iliotibial band has been inconsistently reported. Treatment varies according to the disease phase and, in the acute phase, consists of rest, physical therapy, and anti-inflammatory medications. Ultrasound-guided local steroid injections are effective in relieving symptoms.

Operative Versus Nonoperative Management of Distal Iliotibial Band Syndrome-Where Do We Stand? A Systematic Review

Purpose

To systematically review the operative versus nonoperative methods for management of iliotibial band syndrome (ITBS) with comparison of the respective clinical outcomes.

Methods

By adhering to the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines, 3 databases (Medline, Scopus, Web of Science) searched from inception to October 2019 for randomized clinical trials (RCTs) and observational studies on humans that reported the outcomes following operative or nonoperative management of ITBS. Excluded were case reports, case series with <5 participants, review articles, non-English articles, and non–peer-reviewed articles. The Methodological Index for Non-Randomized Studies (MINORS) criteria for observational studies and the Cochrane Risk of Bias Tool for RCTs were used for quality control.

Results

There were 15 eligible studies (9 for operative,6 for nonoperative treatment) examining 179 athletes (mean age 27.3 years, range: 17-53) who received conservative therapy for ITBS and 200 athletes (mean age 30.1 years, range: 14-63) who underwent surgical treatment. Most athletes were runners (65%). The mean follow-up time was significantly longer in studies reporting the outcomes following operative compared with nonoperative ITBS treatment (33.5 vs 2 months, respectively, P < .05). Significant variability in the methods used to assess the clinical outcomes precluded meta-analysis. The most commonly reported (7/9 studies, 77.7%) variable for postoperative evaluation in athletes was the return to sport rate (range: 81%-100%). Significant reduction in pain was consistently (6/6 studies,100%) found among the studies reporting the results of conservative ITBS treatment. The included RCTs were of good (1/5, 20%), fair (2/5, 40%), or poor (2/5, 40%) quality, whereas the average MINORS score was 7.4 (range: 3-13) for observational studies. The level of evidence ranged from Level II (6/15 studies) to IV (9/15 studies).

Conclusions

Based on the current literature and at a maximum follow-up time of 6 months, conservative therapy can effectively reduce ITBS symptoms in athletes. Multiple surgical options exist for athletes who do not respond to nonoperative measures, with a reported return to sport rate between 81% and 100%.

Level of Evidence

Systematic review of Level II and IV studies

Magnetic resonance imaging of impingement and friction syndromes around the knee

The knee is a complex joint with its function dependent on a combination of osseous and soft tissue structures. Alteration in the relationship of these tissues, due to either acute or chronic repetitive injury with possible underlying congenital predisposing factors, can result in impingement between the structures resulting in pain, particularly on activity. The purpose of this article is to provide a comprehensive review of the MRI features of various impingement syndromes around the knee.

Iliotibial band syndrome rehabilitation in female runners: a pilot randomized study

Background

Iliotibial band syndrome (ITBS) carries marked morbidity in runners. Its management is not standardized and lacks evidence base. We evaluated the effectiveness of three different exercises programs in reducing ITBS symptoms.

Methods

Patients were divided into three equal treatment groups: ITB stretching (group A), conventional exercise (group B), and experimental hip strengthening exercise (group C). Numeric pain rating scale (NPRS; every week), lower extremity functional scale (LEFS; every 2 weeks), dynamometer (DN; weeks 0, 2, 4, 6, 8), single-limb mini squat (SLMS; week 0, 8), and Y-balance test™ (YBT), between and within group’s differences were evaluated using ANOVA model.

Results

Twenty-four female runners (age 19–45 years) were included into one of three groups (A, B, and C). Statistical significance (p < 0.05) within group C was observed for composite YBT and DN for injured and non-injured leg, the YBT (injured leg for the posterior medial), LEFS, NPRS, and the SLMS. Statistical significance (p < 0.05) was found between group A and group C. The stretching group exhibited statistically significant (p < 0.05) YBT anterior reach for the injured/non-injured leg and the LEFS.

Conclusion

There were no statistical differences between the three groups. The subjects who underwent experimental hip strengthening exercises consistently showed improvements in outcome measures, and never scored less than the other two groups.

Trial registration

ClinicalTrials.gov identifier (NCT number): NCT0229615

THE TENSILE BEHAVIORS OF THE ILIOTIBIAL BAND - A CADAVERIC INVESTIGATION

BACKGROUND

Clinical stretching is frequently recommended for iliotibial band syndrome management. Current literature lacks conclusive findings regarding isolated human iliotibial band tissue elongation and stiffness behaviors. Applying clinical-grade stretching force results to iliotibial band tissue behavior is thus challenging.

PURPOSE

This study's objectives were to determine isolated iliotibial band tissue tensile behaviors during tension-to-failure testing and to relate the results to previously reported iliotibial band stretch findings.

STUDY DESIGN

Descriptive in vitro laboratory study.

METHODS

Ten isolated un-embalmed iliotibial band specimens were exposed to tension-to-failure testing using a 10kN material testing system. Peak load, load at yield point, and ultimate failure load were measured in Newtons. Corresponding absolute (mm) and relative (%) tissue deformation was recorded. Load-deformation curves were established to calculate iliotibial band stiffness (N/mm).

RESULTS

A mean peak load of 872.8 ± 285.9N and resulting 9.0 ± 3.9% tissue deformation from initial length was recorded. An 805.5 ± 249.7N mean load at yield point and resulting 7.0 ± 1.9% tissue deformation was observed. A 727.6 ± 258.4N mean load was recorded directly prior to ultimate tissue failure. Mean tissue deformation at ultimate failure was 11.3 ± 4.2%. Mean iliotibial band system stiffness was 27.2 ± 4.5N/mm.

CONCLUSION

The iliotibial band can withstand substantial tensile forces. Clinical stretching forces likely fall within the load-deformation curve elastic region and may not result in permanent iliotibial band tissue deformation. Sustained elongation resulting from stretching the ITB may require substantial patient compliance. Future studies should investigate potential underlying factors related to positive symptom relief from iliotibial band stretching that include immunological responses, fluid accumulation, altered proprioception, and pain perception.

LEVEL OF EVIDENCE

3.

A LITERATURE REVIEW AND CLINICAL COMMENTARY ON THE DEVELOPMENT OF ILIOTIBIAL BAND SYNDROME IN RUNNERS

BACKGROUND AND PURPOSE

Iliotibial Band Syndrome (ITBS) is the second leading cause of pain in runners and there are a number of theories related to its etiology. Multiple theories exist for the etiology of ITBS related symptoms including anterior-posterior friction of the IT band on the lateral femoral condyle during knee flexion and extension activities, compression of a layer of fat near the IT band distal attachment, and inflammation of the IT band bursa. The purpose of this literature review and clinical commentary was to explore the potential factors that contribute to ITBS development in runners.

DESCRIPTION OF TOPIC WITH RELATED EVIDENCE

A literature review was performed to gather relevant evidence related to the topic and then categorized according to prospective and retrospective results. The electronic databases PubMed, EBSCOhost, CINAHL, and SportDiscus were utilized with the search terms iliotibial band, iliotibial band syndrome, iliotibial pain, and runners. The inclusion criteria included English-language, peer-reviewed journals; adult male or female runners, whether competitive or recreational with regard to mileage; subjects that either had a previous or existing diagnosis of ITBS or were at risk for developing ITBS; retrospective and prospective designs were included and the majority of studies reviewed were cohort or case-control designs.

DISCUSSION/RELATION TO CLINICAL PRACTICE

The literature was either contradictory or inconclusive to support a link between ITBS and decreased muscle strength or endurance. A weak correlation existed between strain rate of the hip abductor muscles with hip adduction and knee internal rotation, increased knee internal rotation during the stance phase of gait, and a diminished rearfoot eversion angle at heel strike. Additionally, decreased hip adduction angles during stance phase were observed in individuals without active symptoms but who had a previous history of ITBS. Finally, the female gender may be a predisposing factor.

LEVEL OF EVIDENCE

5.

Flexion First Balancer: description of new technique in TKA to reproduce joint line and pre-disease mechanical alignment

A considerable proportion of patients (19%) are dissatisfied after total knee arthroplasty (TKA). Possible factors contributing to this dissatisfaction are decreased posterior condylar offset (PCO) with subsequent joint line elevation, leading to mid-flexion instability. Secondly, the pre-disease mechanical alignment is changed into a neutral alignment. The Flexion First Balancer was developed to avoid these problems. This technique aims to maintain MCL isometry by restoring medial PCO and medial joint line to its pre-disease level. Also, to reconstruct the pre-disease mechanical alignment by adjusting the distal femoral angle. In this study we provide a detailed technical overview of the Flexion First Balancer technique.

Relationship between iliotibial band syndrome and hip neuromechanics in women runners

BACKGROUND

Atypical frontal plane hip kinematics are associated with iliotibial band syndrome in women runners. Gluteus medius is the primary muscle controlling the hip adduction angle during the loading response of stance. It is unclear if differences exist in gluteus medius activity magnitude and activity duration between runners with previous iliotibial band syndrome and controls. Furthermore, hip neuromechanics may change after a prolonged run.

RESEARCH QUESTION

Do differences exist in the hip adduction angle and gluteus medius activity between women with previous iliotibial band syndrome and controls at the beginning and end of a 30-minute moderate paced treadmill run?

METHODS

Thirty women participated (n = 15 controls). Lower extremity kinematics and gluteus medius activity were recorded at the start and end of a 30-minute treadmill run at participants' self-selected pace. Hip kinematics and gluteus medius activity were analyzed via separate two-way (group x time) mixed-model analysis of variance with time as the repeated measure.

RESULTS

Hip neuromechanics were similar at the start and end of a 30-minute treadmill run in women with previous iliotibial band syndrome and controls. However, hip adduction excursion was less in women with previous iliotibial band syndrome compared to controls. Average gluteus medius activity magnitude and activity duration were not significantly different between groups.

SIGNIFICANCE

These findings support the growing body of literature that smaller hip adduction motion is related to previous iliotibial band syndrome in women. Regardless of injury history, gluteus medius activity was similar between groups during the loading phase of stance.

THE CONSTRAINING EFFECT OF THE LATERAL FEMORAL INTERMUSCULAR SEPTUM ON PASSIVE HIP ADDUCTION IN UN-EMBALMED CADAVERS

BACKGROUND

Due to the lack of verifiable iliotibial band elongation in response to stretching, the anatomical, biomechanical, and physiological responses to treatment of iliotibial band syndrome remain unclear. The lateral intermuscular septum, consisting of multiple myofibroblasts, firmly anchors the iliotibial band to the femur.

PURPOSE AND HYPOTHESIS

The purpose of this in-situ study was to examine the constraining effect of the lateral intermuscular septum on available passive hip adduction range of motion in un-embalmed cadavers. It was hypothesized that an iliotibial band-septum-complex release would significantly increase passive hip adduction.

DESIGN

Within-specimen repeated measures in-situ design.

SETTING

Anatomy laboratory.

METHODS

Metal markers were inserted into selected anatomical landmarks in eleven (11) un-embalmed human cadavers. With the specimen supine, the test-side lower limb was passively adducted until maximum passive hip adduction was reached. This movement was repeated three times each within two conditions: (1) band-septum-complex intact and (2) band-septum-complex dissected. Digital video of marker displacement was captured throughout each trial. Still images from a start and an end position were extracted from each video sequence. A custom Matlab program was used to calculate frontal plane hip adduction angle changes from obtained images.

RESULTS

Mean change in passive hip adduction after band-septum-complex release was -0.3 ° (SD 1.6 °;95% CI: -1.33,0.76). A paired samples t-test revealed a non-significant difference (t=-.611; p=.555) in passive hip adduction for the band-septum-dissected condition (18.8 ± 3.9 °) versus the band-septum-intact condition (18.5 °±4.7 °).

CONCLUSION

The lateral intermuscular septum does not appear to have a constraining effect on passive hip adduction in un-embalmed cadavers. Future research should evaluate the constraining effect of other selected tissues and conditions on hip adduction. Furthermore, inflammatory, metabolic, viscoelastic, and sensorimotor control properties within the iliotibial band in response to stretching should be investigated.

LEVEL OF EVIDENCE

3.

Iliotibial band friction syndrome after knee arthroplasty

Iliotibial band (ITB) friction syndrome is known to be one of the main causes of lateral knee pain related to an overuse injury. In the field of knee arthroplasty, ITB traction syndrome has been reported following guided motion total knee arthroplasty, due to posterior femoral translation and internal tibial rotation during knee flexion. However, ITB friction syndrome following conventional knee arthroplasty has not been reported. This paper reports four cases of this syndrome following conventional knee arthroplasty, mainly caused by an obstruction just under the ITB. Cases 1 and 2 presented extruded cement at the femoral component's lateral side after total knee arthroplasty. Case 3 presented a highly sharp-edged bearing at the lateral compartment after bicompartmental knee arthroplasty. Case 4 presented an osteophyte at the femoral component's lateral side after total knee arthroplasty. Although none of the cases responded well to conservative treatment, ITB friction syndrome was completely relieved just after excising the obstruction. Excision of an obstruction should be considered for ITB friction syndrome caused by obstruction just under the ITB following knee arthroplasty.

Sex Differences in Iliotibial Band Strain under Different Knee Alignments

BACKGROUND

Increased strain of the iliotibial band (ITB) is a plausible contributing factor for the development of iliotibial band syndrome (ITBS). Although several studies have found relationships between the strain of the ITB and kinematic factors during running, the associations of the ITB strain with knee alignment and sex, which are considered intrinsic factors, are not well understood.

OBJECTIVE

To clarify the sex differences in the ITB strain between genu varum and normal knee alignments in different postures.

DESIGN

Observational cross-sectional study.

SETTING

Laboratory research within a university.

PARTICIPANTS

Forty-four healthy recreational athletes (21 men and 23 women) volunteered for this study and were divided into four groups by sex and knee alignment: men with genu varum alignment, men with normal knee alignment, women with genu varum alignment, and women with normal knee alignment.

METHODS

An ultrasound real-time elastography (RTE) unit was used for distal ITB strain measurements in weight bearing and for different non-weight-bearing: neutral, knee flexion, hip adduction, and hip adduction with knee flexion. Gender information and the intercondylar distance data were collected to divide the participants into two groups.

MAIN OUTCOME MEASUREMENTS

Main Outcome was the ITB strain (strain ratio) measured by the RTE.

RESULTS

There were no significant differences in neutral and hip adduction postures among the four groups. However, during weight-bearing, the women's genu varum group (6.91 ± 1.69; Mean ± SD) exhibited greater strain than both the men's normal group (3.50 ± 1.04, P = .005) and the women's normal group (4.42 ± 1.42, P = .048). In addition, there were significant positive correlations between the intercondylar distance and the ITB strain during weight-bearing (r = 0.315, P = .037).

CONCLUSIONS

The women's genu varum group exhibited a higher ITB strain during weight-bearing, which may be related to the high incidence of ITBS in women athletes. Furthermore, the changes in alignment and muscle activities during weight-bearing could influence the strain of the ITB.

LEVEL OF EVIDENCE

III.

A comparative multi-site and whole-body assessment of fascia in the horse and dog: a detailed histological investigation

Fascia in the veterinary sciences is drawing attention, such that physiotherapists and animal practitioners are now applying techniques based on the concept of fascia studies in humans. A comprehensive study of fascia is therefore needed in animals to understand the arrangement of the fascial layers in an unguligrade horse and a digitigrade dog. This study has examined the difference between the horse and the dog fascia at specific regions, in terms of histology, and has compared it with the human model. Histological examinations show that in general the fascia tissue of the horse exhibits a tight and dense composition, while in the dog it is looser and has non-dense structure. Indeed, equine fascia appears to be different from both canine fascia and the human fascia model, whilst canine fascia is very comparable to the human model. Although regional variations were observed, the superficial fascia (fascia superficialis) in the horse was found to be trilaminar in the trunk, yet multilayered in the dog. Moreover, crimping of collagen fibers was more visible in the horse than the dog. Blood vessels and nerves were present in the loose areolar tissue of the superficial and the profound compartment of hypodermis. The deep fascia (fascia profunda) in the horse was thick and tightly attached to the underlying muscle, while in the dog the deep fascia was thin and loosely attached to underlying structures. Superficial and deep fascia fused in the extremities. In conclusion, gross dissection and histology have revealed species variations that are related to the absence or presence of the superficial adipose tissue, the retinacula cutis superficialis, the localization and amount of elastic fibers, as well as the ability to slide and glide between the different layers. Further research is now needed to understand in more detail whether these differences have an influence on the biomechanics, movements and proprioception of these animals.

Influence of Previous Iliotibial Band Syndrome on Coordination Patterns and Coordination Variability in Female Runners

It is unknown if female runners that have sustained multiple iliotibial band syndrome occurrences run differently compared to runners that developed the injury once or controls. Therefore, the purpose of this study was to determine if differences existed in coordination patterns and coordination variability among female runners with recurrent iliotibial band syndrome, one iliotibial band syndrome occurrence, and controls. Overground running trials were collected for 36 female runners (n = 18 controls). Lower extremity coordination patterns were examined during running via a vector coding analysis. Coordination variability was calculated via the ellipse area method. Separate one-way (group) Kruskal-Wallis tests were performed to compare each coordination pattern and coordination variability. Lower extremity coordination between frontal plane hip - transverse plane hip, frontal plane pelvis - frontal plane thigh, and frontal plane thigh - transverse plane shank was similar among groups and so may not be related to the risk of iliotibial band syndrome. Runners with one iliotibial band syndrome occurrence demonstrated greater coordination variability for two of three couplings compared to both controls and runners with recurrent iliotibial band syndrome. Thus, the number of previous injury episodes may influence coordination variability in female runners with a history of iliotibial band syndrome.

Migrating Myofibroblastic Iliotibial Band-Derived Fibroblasts Represent a Promising Cell Source for Ligament Reconstruction

The iliotibial band (ITB) is a suitable scaffold for anterior cruciate ligament (ACL) reconstruction, providing a sufficient mechanical resistance to loading. Hence, ITB-derived fibroblasts attract interest for ligament tissue engineering but have so far not been characterized. This present study aimed at characterizing ITB fibroblasts before, during, and after emigration from cadaveric ITB explants to decipher the emigration behavior and to utilize their migratory capacity for seeding biomaterials. ITB and, for comparison, ACL tissues were assessed for the content of alpha smooth muscle actin (αSMA) expressing fibroblasts and degeneration. The cell survival and αSMA expression were monitored in explants used for cell isolation, monolayer, self-assembled ITB spheroids, and spheroids seeded in polyglycolic acid (PGA) scaffolds. The protein expression profile of targets typically expressed by ligamentocytes (collagen types I-III, elastin, lubricin, decorin, aggrecan, fibronectin, tenascin C, CD44, β1-integrins, vimentin, F-actin, αSMA, and vascular endothelial growth factor A [VEGFA]) was compared between ITB and ACL fibroblasts. A donor- and age-dependent differing percentage of αSMA positive cells could be detected, which was similar in ITB and ACL tissues despite the grade of degeneration being significantly higher in the ACL due to harvesting them from OA knees. ITB fibroblasts survived for several months in an explant culture, continuously forming monolayers with VEGFA and an increased αSMA expression. They shared their expression profile with ACL fibroblasts. αSMA decreased during the monolayer to spheroid/scaffold transition. Using self-assembled spheroids, the migratory capacity of reversible myofibroblastic ITB cells can be utilized for colonizing biomaterials for ACL tissue engineering and to support ligament healing.

Effects of running biomechanics on the occurrence of iliotibial band syndrome in male runners during an eight-week running programme-a prospective study

Iliotibial band syndrome (ITBS) is a common injury that is related to running biomechanics. This study aimed to determine the gait characteristics that easily induce ITBS and explore the gait changes after the occurrence of ITBS. Thirty healthy male recreational runners participated in our study. Amongst them, 15 developed ITBS and comprised the ITBS group; the other 15 were healthy and comprised the control group. All participants underwent two gait trials, namely, before the first day of their running and after eight weeks, during which a force platform and a motion capture system collected biomechanical data. After running, the ITBS group exhibited greater anterior pelvic tilt and hip flexion angle than the control group. The ITBS group showed increased trunk inclination angle, whereas the control group demonstrated lower hip flexion, hip adduction angle and hip abductor moment than those at the beginning of running. Decreasing hip flexion, adduction angle and abductor moment may be a reasonable strategy to avoid the occurrence of ITBS. The occurrence of ITBS may be due to the lack of timely gait adjustment. Excessive trunk inclination and anterior pelvic tilt angle may be risks factor in the development of ITBS during running.

An Overview of Anatomy and Imaging of the Anterolateral Structures of the Knee

Despite several previous articles in the literature, never before have so many studies with regard to anterolateral knee structures been performed. The anterolateral knee complex consists briefly of the iliotibial band, with its proximal and distal attachments, the joint capsule, and the anterolateral ligament (ALL). The recently introduced ALL has several different descriptions, making it difficult to build a consensus with regard to its anatomy. An extensive description of these structures, particularly the iliotibial band and the ALL, with regard to anatomy and imaging, will be provided in this article.

Proximal iliotibial band thickness as a cause for recalcitrant greater trochanteric pain syndrome

To investigate iliotibial band (ITB) diameter thickness at the greater trochanter in patients requiring iliotibial band release who have failed conservative modalities, in comparison to an asymptomatic patient population. A total of 68 subjects were selected to be reviewed using T2 axial plane MRI. The ITB diameter thickness was measured in 34 subjects who underwent surgical ITB release, and compared with a match-paired asymptomatic hip cohort consisting of 34 subjects. ITB diameter thickness was measured at the thickest location for each subject twice by two different examiners. Inter/intra class correlation coefficient was determined for ITB measurement technique accuracy, and the presence of recalcitrant proximal hip pain was evaluated. Interclass correlation coefficient with 95% confidence was measured to be 0.953. The average thickness for ITB surgical release subjects was measured to be 5.61 ± 2.10 mm, and for asymptomatic subjects 3.77 ± 0.79 mm (P < 0.001). The results of this study demonstrate a statistically significant positive relationship of an increased diameter thickness in the ITB in symptomatic patients who failed conservative therapy and underwent surgical intervention for treatment.

THE EFFECTS OF AN ACUTE BOUT OF FOAM ROLLING ON HIP RANGE OF MOTION ON DIFFERENT TISSUES

BACKGROUND

Foam Rolling (FR) has steadily gained in popularity as an intervention to increase range of motion (ROM) and reduce pain. It is believed that FR can remove restrictions due to fascial adhesions, thus improving ROM. FR has been proposed as a means to increase ITB length as a means to achieve these outcomes. Previous research has focused on the effects of FR over both muscle and fascia tissue together. However, no studies have examined the effects of FR over fascial tissue not containing muscle.

PURPOSE

The purpose of this study was to compare the acute effect of a single bout of foam rolling (FR) over the Iliotibial Band (ITB) compared to FR over the gluteal muscle group on hip adduction passive range of motion (PROM).

METHODS

Twenty-seven participants were recruited for the study. Each participant performed three sessions: FR over tissue devoid of muscle, the ITB (PFR), FR over contractile tissue, the gluteal muscles (AFR), and a session without FR (control) in a randomized order. Hip adduction PROM was measured in a pre-post manner for each session.

RESULTS

Results of the repeated measures ANOVA showed a significant interaction across session and time (F_{(2, 25)} = 25.202, p < 0.001, ηp2 = 0.502, 1 - β = 1.000). Post-hoc analysis showed the AFR post-test measure was significantly different from both control (p < 0.001) and PFR counterparts (p < 0.001). FR over the gluteal muscle group lead to a 14.8% improvement in hip adduction ROM, with PFR only a 2% improvement.

CONCLUSION

A single bout of FR over a myofascial group appears to increase PROM in healthy young adults, whereas FR over the ITB itself (primarily fascial tissue) does not. This suggests the conventional theory behind FR may need to be reevaluated.

LEVEL OF EVIDENCE

Level 1B, laboratory study, repeated measures design.