Heel fat pad involvement in rheumatoid arthritis and in spondyloarthropathies: an ultrasonographic study

Asymptomatic sonographic abnormalities of the hindfoot region in Division I collegiate gymnasts

BACKGROUND

The hindfoot region is commonly injured in gymnasts, and musculoskeletal ultrasound can be used to identify structural abnormalities in this region. Although prior studies have shown that sonographic abnormalities may not correlate with symptomatic pathology, the presence of asymptomatic sonographic abnormalities of the hindfoot in Division I collegiate gymnasts has not been evaluated.

OBJECTIVE

To identify and describe commonly seen asymptomatic sonographic abnormalities of the hindfoot region in Division I collegiate gymnasts.

DESIGN

Cross-sectional study.

SETTING

Tertiary care academic medical center.

PARTICIPANTS

39 Division I NCAA men's and women's collegiate gymnasts without current hindfoot pain or history of hindfoot injury.

INTERVENTIONS

Diagnostic musculoskeletal ultrasound of the hindfoot region.

MAIN OUTCOME MEASURES

Sonographic appearance of the hindfoot region, specifically the plantar fascia, plantar fad pad, and Achilles tendon.

RESULTS

A total of 37 of 39 gymnasts included in the study were found to have at least one asymptomatic sonographic abnormality of the hindfoot region. A total of 28.2% of athletes were found to have sonographic abnormalities within the Achilles tendon, with Doppler flow being the most common finding, and 35.8% of athletes were found to have a Haglund's deformity. However, only 7% of athletes with a Haglund's deformity demonstrated abnormal sonographic findings within the tendon. Sonographic abnormalities of the plantar fascia and plantar fat pad were seen in 30.7% and 69.2% of athletes, respectively.

CONCLUSIONS

Asymptomatic sonographic abnormalities of the hindfoot region are common in collegiate gymnasts. Clinicians should use clinical judgment when interpreting these findings as they may not represent symptomatic pathology.

Plantar Fasciitis: An Updated Review

Plantar fasciitis (PF) is a common musculoskeletal disease. Histologic findings of patients with PF showed mainly chronic degenerative processes rather than inflammation. In addition to mechanical factors, such as repetitive stress and reduced ankle dorsiflexion, PF is also linked to rheumatologic diseases and genetic factors. Ultrasound is becoming a standard imaging technique for assessing PF. Major sonographic findings included increased plantar fascia thickness and hypoechoic plantar fascia. In addition to traditional B-mode ultrasound, sonoelastography can also be utilized to diagnose PF. Ultrasound can also be used to guide therapeutic interventions. Over 80% of patients with PF improved under nonsurgical treatment. Treatment options for PF include physical therapy, modalities (laser, therapeutic ultrasound), extracorporeal shock wave therapy (ESWT), injections, transcatheter arterial embolization, and surgery. For injections, corticosteroid was mostly used in the past but has been replaced gradually by other techniques such as platelet-rich plasma or dextrose prolotherapy. There is also more and more evidence about ESWT in treating PF. Surgery serves as an option for recalcitrant PF cases, and endoscopic fasciotomy seemed to have good outcomes. Ultrasound plays an important role in diagnosing of PF and evaluating the treatment effect, and the use of sonoelastography in addition to traditional B-mode ultrasound may help in the early detection of PF and assessment of the treatment effect.

A problem-based approach in musculoskeletal ultrasonography: heel pain in adults

Musculoskeletal ultrasonography (US) has unique advantages, such as excellent spatial resolution for superficial structures, the capability for dynamic imaging, and the ability for direct correlation and provocation of symptoms. For these reasons, US is increasingly used to evaluate problems in small joints, such as the foot and ankle. However, it is almost impossible to evaluate every anatomic structure within a limited time. Therefore, US examinations can be faster and more efficient if radiologists know where to look and image patients with typical symptoms. In this review, common etiologies of heel pain are discussed in a problem-based manner. Knowing the common pain sources and being familiar with their US findings will help radiologists to perform accurate and effective US examinations.

Heel fat pad syndrome beyond acute plantar fascitis

Heel pain is a frequent cause of pain and disability in adult active population. In patients with this clinical presentation, several causes must be ruled out, among them plantar fasciitis the most common. Other etiologies of plantar heel pain are the entrapment of muscular branch of the lateral plantar nerve (Baxter nerve) or fat pad atrophy, being the last one the second cause of heel pain after plantar fasciitis. A case series of patients with pathological findings of the heel fat pad area using MRI and US to provide a differential diagnosis of heel pain. Observational case series study. Nine patients visited presented with pain in the plantar aspect of the heel. The plantar aspect of the heel was evaluated in detail with US and MRI. Main inclusion criteria were to present acute or chronic pain on the plantar aspect. In five cases the right heel was affected, in three cases the left heel. One case presented bilateral complaints. All patients presented mechanical pain. Specifically, four of them also described a constant clunk during footstep. Heel fat pad lesion was confirmed with MRI and US in the medial aspect, observed in five patients. In four patients, the heel fat pad was globally affected respectively. This case series tries to put some light on other heel conflicts beside plantar fasciitis that should be ruled out, being one of those, heel fat pad atrophy. Our presentation highlight the role that bed side ultrasound can play in the definition of a specific pattern confirmed with MRI after the US.

Subluxing fractured plantar fat pad: a case series and description of novel sonographic findings

Plantar fat pad syndrome has received little attention in the literature. A variety of structural changes of the plantar fat pad have been described in the literature, including atrophy, contusion, and fractured fat pad. This case series presents 4 patients (5 heels) with subluxation of a fractured plantar fat pad on dynamic ultrasound. Patients with subluxing fractured fat pad typically present with heel pain and a "snapping" or "popping" sensation when weight-bearing. Other causes of heel pain were excluded, and all patients in this series had an MRI that initially did not report any findings in the fat pad. Retrospective review of the MRI showed evidence of diffuse low T1 and T2 infiltration. To the authors' knowledge, subluxation of the plantar fat pad and the respective correlation to MRI findings have not been described in the literature. Here we describe the sonographic findings of this novel condition.

Heel fat pad involvement in rheumatoid arthritis: a review and case series

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease affecting not only the synovial joints but also multiple extra-articular sites, including ankle and foot soft tissue. Hindfoot abnormalities usually follow those in the forefoot, with up to 4 out of 10 patients experiencing talalgia during their disease course. Enthesophytosis, retrocalcaneal bursitis, and plantar fasciitis are among the most common etiologies, while heel fat pad abnormalities like subcalcaneal bursitis are rare. Here, we report two cases of subcalcaneal bursitis, and the first case of heel fat pad and subcalcaneal bursa herniation in patients with established RA, along with a comprehensive literature review of subcalcaneal bursitis and other heel fat pad abnormalities in RA. Subcalcaneal bursitis, also referred to as panniculitis, inflammatory-edematous lesion, or adventitial (adventitious) bursitis has been reported in up to 10% of patients with RA. It appears as a compressible, heterogeneous, and hypoechoic subcalcaneal mass on ultrasound (US), with peripheral vascularization on Doppler US. Patients may present with heel discomfort. Ultrasonographic assessment is usually sufficient to confirm the presence of heel fat pad pathologies. Rest, analgesics, and mechanical aids with or without addition of disease-modifying antirheumatic drugs are usually employed, while intervention is rarely required.

Identification of distinct transcriptome signatures of human adipose tissue from fifteen depots

The functional and metabolic characteristics of specific adipose tissue (AT) depots seem to be determined by intrinsic mechanisms. We performed a comprehensive transcriptome profiling of human AT from distinct fat depots to unravel their unique features potentially explaining molecular mechanisms underlying AT distribution and their contribution to health and disease. Post-mortem AT samples of five body donors from 15 anatomical locations were collected. Global mRNA expression was measured by Illumina® Human HT-12 v4 Expression BeadChips. Data were validated using qPCR and Western Blot in a subset of ATs from seven additional body donors. Buccal and heel AT clearly separated from the “classical” subcutaneous AT depots, and perirenal and epicardial AT were distinct from visceral depots. Gene-set enrichment analyses pointed to an inflammatory environment and insulin resistance particularly in the carotid sheath AT depot. Moreover, the epicardial fat transcriptome was enriched for genes involved in extracellular matrix remodeling, inflammation, immune signaling, coagulation, thrombosis, beigeing, and apoptosis. Interestingly, a striking downregulation of the expression of leptin receptor was found in AT from heel compared with all other AT depots. The distinct gene expression patterns are likely to define fat depot specific AT functions in metabolism, energy storage, immunity, body insulation or as cushions. Improved knowledge of the gene expression profiles of various fat depots may strongly benefit studies aimed at better understanding of the genetics and the pathophysiology of obesity and adverse body fat composition.

Local effects of adipose tissue in psoriasis and psoriatic arthritis

The structure and physiological state of the local white adipose tissue (WAT) located underneath the lesional psoriatic skin and inside of the joints affected by psoriatic arthritis play an important role in the pathophysiology of these diseases. WAT pads associated with inflammatory sites in psoriasis and psoriatic arthritis are, correspondingly, dermal WAT and articular adipose tissue; these pads demonstrate inflammatory phenotypes in both diseases. Such local WAT inflammation could be the primary effect in the pathophysiology of psoriasis leading to the modification of the local expression of adipokines, a change in the structure of the basement membrane and the release of keratinocytes with consequent epidermal hyperproliferation during psoriasis. Similar articular adipose tissue inflammation can lead to the induction of structural modifications and synovial inflammation in the joints of patients with psoriatic arthritis.

Sonographic Evaluation of the Plantar Heel in Asymptomatic Endurance Runners

OBJECTIVES

The primary purpose of this investigation was to determine the prevalence and spectrum of asymptomatic sonographically determined structural changes in the plantar fascia and plantar heel pad among experienced runners without a history of heel pain.

METHODS

Thirty-nine asymptomatic runners without a history of plantar heel pain were recruited. The following sonographic measures were recorded: power Doppler sonography in the plantar heel pad and plantar fascia, echo texture of the plantar heel pad, uncompressed heel pad thickness, compressed heel pad thickness, heel pad compressibility index, plantar fascia thickness, and plantar fascia echo texture.

RESULTS

Doppler flow was shown in the plantar heel pads of 88% (68 of 77) of heels and 92% (36 of 39) of runners. Heel pad echo texture abnormalities were found in 86% (66 of 77) of heels and 97% (38 of 39) of runners. Mean values for right and left uncompressed heel pad thickness were 13.8 and 13.7 mm, respectively. The mean heel pad compressibility indices were 0.51 for the right heel and 0.53 for the left heel. Eight percent (6 of 77) of fat pads in 10% (4 of 39) of runners had abnormal compressibility indices. Doppler flow was present in the plantar fascia in 31% (24 of 77) of heels and 44% (17 of 39) of runners. The mean plantar fascia thicknesses were 3.78 mm for the right and 3.87 mm for the left. Forty-eight percent (37 of 77) of heels had an abnormal plantar fascia echo texture.

CONCLUSIONS

At least 1 potentially abnormal sonographic finding was present in each heel of all asymptomatic runners in this study. Consequently, sonographic abnormalities in the plantar heel should be interpreted within the clinical context when evaluating runners.

Complete remission of plantar fasciitis with a gluten-free diet: relationship or just coincidence?

We report the case of a 46-year-old woman with no known history for gluten sensitivity who presented severe heel pain, and was successfully managed with a gluten-free diet. Previously she had been unsuccessfully treated with several conservative remedies. The presence of musculoskeletal problems in patients with gluten sensitivity is not rare. To the best of our knowledge, however, this is the first case report mentioning the successful management of plantar fasciitis with a gluten-free diet. The case report highlights the importance of considering gluten sensitivity among other possible differential diagnosis for musculoskeletal pain insensitive to traditional therapies.

Measurement of functional heel pad behaviour in-shoe during gait using orthotic embedded ultrasonography

The ability to measure the functional behaviour of the plantar heel pad is clinically relevant in dystrophic or pathological heel conditions and may help to inform the design and development of interventions that attempt to restore normal function. In this study we present a novel technique which utilises orthotic heel inserts with an embedded ultrasound (US) transducer to allow the functional, dynamic behaviour of the heel pad to be measured in-shoe during gait. The aim of this study was to demonstrate feasibility of the technique, determine the reproducibility of measurements, and to compare the effects of two orthotic inserts: (i) a flat orthotic heel raise and (ii) a contoured heel cup insert on the behaviour of the heel pad during gait. Dynamic compression of the heel pads of 16 healthy participants was recorded during treadmill walking and combined with plantar pressure measurements to allow stiffness and energy disappation ratio (EDR) to be estimated. Inter-session reliability of the US measurements was found to be excellent (ICC2,1=0.94-0.95), as was inter-rater reliability (ICC2,1=0.89). Use of the heel cup insert significantly reduced the maximum compression of the heel pad (p<0.0001) as well as the overall stiffness of the pad (p<0.001). There was no change in EDR (p=0.949). In-shoe embedded US is a reliable method to establish person-specific functional geometry of plantar soft tissues. Use of a contoured heel cup reduces the compression of the mid portion of the heel pad.

Joint appendages: the structures which have historically been overlooked in arthritis research and therapy development

Rheumatologists have largely conceptualised joint disease in inflammatory and degenerative arthritis in terms of bone, cartilage and the synovial lining, but have tended to overlook other integral components of the joints which are attached close to joint margins. We discuss these structures under the umbrella term of 'appendages'. These structures include ligaments, tendons, entheses or joint insertions, regional fibrocartilages, bursae and other peri-articular joint structures including fat pads and nails. In this review, we highlight how these structures play key pathophysiological roles in inflammatory arthritis and we emphasise how an understanding of these structures is collectively important for both clinical practice and future rheumatological research.

Three-dimensional morphology of heel fat pad: an in vivo computed tomography study

Heel fat pad cushioning efficiency is the result of its structure, shape and thickness. However, while a number of studies have investigated heel fat pad (HFP) anatomy, structural behavior and material properties, no previous study has described its three-dimensional morphology in situ. The assessment of the healthy, unloaded, three-dimensional morphology of heel pad may contribute to deepen the understanding of its role and behavior during locomotion. It is the basis for the assessment of possible HFP morphological modifications due to changes in the amount or distribution of the loads normally sustained by the foot. It may also help in guiding the surgical reconstruction of the pad and in improving footwear design, as well as in developing a correct heel pad geometry for finite element models of the foot. Therefore the purpose of this study was to obtain a complete analysis of HFP three-dimensional morphology in situ. The right foot of nine healthy volunteers was scanned with computed tomography. A methodological approach that maximizes reliability and repeatability of the data was developed by building a device to lock the foot in a neutral position with respect to the scan planes during image acquisition. Scan data were used to reconstruct virtual three-dimensional models for both the calcaneus and HFP. A set of virtual coronal and axial sections were extracted from the three-dimensional model of each HFP and processed to extract a set of one- and two-dimensional morphometrical measurements for a detailed description of heel pad morphology. The tissue exhibited a consistent and sophisticated morphology that may reflect the biomechanics of the foot support. HFP was found to be have a crest on its anterior dorsal surface, flanges on the sides and posteriorly, and a thick portion that reached and covered the posterior surface of the calcaneus and the achilles tendon insertion. Its anterior internal portion was thinner and a lump of fat was consistently present in this region. Finally, HFP was found to be thicker in males than in females.

Plantar enthesopathy: thickening of the enthesis is correlated with energy dissipation of the plantar fat pad during walking

BACKGROUND

The enthesis of the plantar fascia is thought to play an important role in stress dissipation. However, the potential link between entheseal thickening characteristic of enthesopathy and the stress-dissipating properties of the intervening plantar fat pad have not been investigated.

PURPOSE

This study was conducted to identify whether plantar fat pad mechanics explain variance in the thickness of the fascial enthesis in individuals with and without plantar enthesopathy.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

The study population consisted of 9 patients with unilateral plantar enthesopathy and 9 asymptomatic, individually matched controls. The thickness of the enthesis of the symptomatic, asymptomatic, and a matched control limb was acquired using high-resolution ultrasound. The compressive strain of the plantar fat pad during walking was estimated from dynamic lateral radiographs acquired with a multifunction fluoroscopy unit. Peak compressive stress was simultaneously acquired via a pressure platform. Principal viscoelastic parameters were estimated from subsequent stress-strain curves.

RESULTS

The symptomatic fascial enthesis (6.7 ± 2.0 mm) was significantly thicker than the asymptomatic enthesis (4.2 ± 0.4 mm), which in turn was thicker than the enthesis (3.3 ± 0.4 mm) of control limbs (P < .05). There was no significant difference in the mean thickness, peak stress, peak strain, or secant modulus of the plantar fat pad between limbs. However, the energy dissipated by the fat pad during loading and unloading was significantly lower in the symptomatic limb (0.55 ± 0.17) when compared with asymptomatic (0.69 ± 0.13) and control (0.70 ± 0.09) limbs (P < .05). The sonographic thickness of the enthesis was correlated with the energy dissipation ratio of the plantar fat pad (r = .72, P < .05), but only in the symptomatic limb.

CONCLUSION

The energy-dissipating properties of the plantar fat pad are associated with the sonograpic appearance of the enthesis in symptomatic limbs, providing a previously unidentified link between the mechanical behavior of the plantar fat pad and enthesopathy.

Systemic causes of heel pain

The clinical course of heel pain can be frustrating to the clinician and the patient. Most heel pain responds to conservative care in a short period of time. However, other causes should be considered, especially if the heel pain is recalcitrant to treatment. A detailed history and physical examination, along with appropriate laboratory tests and radiological studies, can direct the physician toward the correct diagnosis. There are many systemic causes of heel pain, some common and others uncommon. Regardless of the incidence, a strong index of suspicion is raised whenever the heel pain fails to respond as routine plantar fasciitis should.

The diagnosis and treatment of heel pain: a clinical practice guideline-revision 2010

Heel pain, whether plantar or posterior, is predominantly a mechanical pathology although an array of diverse pathologies including neurologic, arthritic, traumatic, neoplastic, infectious, or vascular etiologies must be considered. This clinical practice guideline (CPG) is a revision of the original 2001 document developed by the American College of Foot and Ankle Surgeons (ACFAS) heel pain committee.

The real risks of steroid injection for plantar fasciitis, with a review of conservative therapies

This article presents a review of conservative therapies for plantar fasciitis pain reduction with a discussion of steroid therapy risks. The therapies reviewed include orthoses, stretching, extracorporeal shockwave, BTX-A, and corticosteroid injection/iontophoresis. These modes were included based on the availability of double blinded randomized controlled trials. We noted the following findings. Orthoses, regardless of type, can improve pain levels. Plantar stretching shows limited short-term benefit (1 month), but can reflect significant long-term improvement (10 months). Extracorporeal shockwave therapy shows equivocal benefit with some studies showing significant improvement and others showing none. Although BTX-A injections were the least studied, significant pain improvement was demonstrated in the short and long term. Steroid injection/iontophoresis showed significant improvement in the short term (1 month). Steroid therapy, when coupled with plantar stretching, can provide efficacious pain relief; however, steroid injections should be combined with ultrasound monitoring to reduce complications.

Ultrasonography and magnetic resonance imaging of heel fat pad inflammatory-oedematous lesions in rheumatoid arthritis

OBJECTIVE

To study heel fat pad (HFP) inflammatory-oedematous lesions in selected patients with rheumatoid arthritis (RA) using ultrasonography (US) and power Doppler US (PDUS), to describe and compare US features of these lesions with those obtained with magnetic resonance imaging (MRI), and to describe changes in the lesions after a short-term follow-up with conventional or anti-tumour necrosis factor-alpha (TNFalpha) therapy.

METHODS

Twelve heels of eight RA outpatients with HFP inflammatory-oedematous lesions were studied by US, PDUS, and unenhanced MRI. All the patients were followed up and US was performed after 3 months. Five patients started on anti-TNFalpha therapy.

RESULTS

HFP lesions appeared at US as a heterogeneous and hypoechoic subcalcaneal mass, with loss of normal lobular structure and increased thickness of HFP, because of focal rupture of fibrous septae with oedema and fluid. PDUS showed peripheral vascularization of HFP lesions in 9/12 heels. In 3/12 heels some vascular signals was also detectable inside the lesion, always along the residual echoic septa. No detectable flow was observed within the central fluid-filled spaces. MRI of the HFP lesions showed areas of mean intensity in T1-weighted sequences and high intensity in T2-weighted sequences, with poorly or well-defined margins. After 3 months, PDUS showed reduction in HFP lesion vascularity (associated with reduction in pain) in 10/12 heels, while poor regression of grey-scale US abnormalities was observed.

CONCLUSIONS

Both US and MRI are capable of demonstrating structural abnormalities in the HFP. PDUS is useful to assess and monitor inflammatory vascularization of the HFP lesions.

Heel pad thickness and athletic activity in healthy young adults: a sonographic study

PURPOSE

The aim of this study was to investigate the sonographic changes of heel fat pad thickness and compressibility index in healthy young adults in relation to level of athletic activity.

MATERIALS AND METHODS

One hundred ten young adults (55 women and 55 men) with a body mass index between 18.5 and 24.9 were divided into 3 groups according to their athletic activity level: group 1, sedentary (n = 50); group 2, athletic activity <7 hours/week (n = 30); and group 3, athletic activity >or=7 hours/week (n = 30). The loaded heel pad thickness (LHPT) and unloaded heel pad thickness (ULHPT) were measured via sonography, and the heel pad compressibility index (HPCI) was calculated.

RESULTS

The mean values of ULHPT, LHPT, and HPCI in group 1 were similar to those of group 2 (p > 0.05) and group 3 (p > 0.05). The mean values of ULHPT, LHPT, and HPCI were similar in the left and right feet in the 3 groups (p > 0.05). There was no correlation between level of athletic activity and ULHPT, LHPT, or HPCI.

CONCLUSIONS

The heel pad thickness and HPCI of individuals engaging in athletic activity up to an average of 11 hours/week were similar to those of sedentary individuals.

Ultrasound detection of entheseal insertions in the foot of patients with spondyloarthropathy

The aim of the study was to evaluate entheseal involvement in the foot of patients with spondyloarthropathy (SpA) by ultrasonographic (US) examination and compare the results with clinical and radiological findings. Forty-four patients (27 men, 17 women) with a diagnosis of SpA were recruited. Patient evaluation included physical examination (swelling and pain), Bath Ankylosing Spondylitis Radiological Index, Bath Ankylosing Spondylitis Disease Activity, Bath Ankylosing Spondylitis Metrological Index, and laboratory parameters (erythrocyte sedimentation rate, C-reactive protein). Foot x-rays of the patients were assessed and scored according to SpA Tarsal Radiographic Index (SpA-TRI). A high-resolution US was used to examine the tendon and ligament insertion sites in the foot, and the findings were scored according to Glasgow Ultrasound Enthesitis Scoring System (GUESS). The mean age and disease duration of the patients were 39.9+/-12.5 and 9+/-8.2 years, respectively. US revealed pathological findings in 25 of 44 (56.8%) patients, most of whom exhibited no clinical signs of foot involvement. Pain and swelling at entheseal insertions were detected in only 16 (37%) patients. The mean GUESS score and SpA-TRI score were 2.2+/-2.5 and 3.3+/-3.7, respectively. There was a correlation between the scores of GUESS and SpA-TRI, particularly at the Achilles and plantar fascia insertion sites. The mean score of SpA-TRI was higher in patients with enthesopathy, detected by US, than in patients without enthesopathy (4.6+/-4.4 vs 1.8+/-2.1). There was no significant correlation between the mean GUESS score and clinical and laboratory variables. In conclusion, involvement of tendon and entheses is not rare, and US is a valuable diagnostic method in detecting subclinical enthesopathic changes. The GUESS and SpA-TRI are suggested in quantifying US and radiological changes in the foot of patients with SpA.