Magnetic resonance imaging evaluation of calcaneal fat pads in patients with os calcis fractures

Analysis of Nonweightbearing MRI Fat Pad Thickness Under Central Metatarsals in Patients With and Without Metatarsalgia

BACKGROUND

Metatarsalgia is a common diagnosis for patients with forefoot pain. Many have proposed metatarsal fat pad atrophy is a cause of metatarsalgia and therefore have suggested fat grafting instead of distal metatarsal osteotomies to treat metatarsalgia. For fat grafting to be a viable treatment, fat pad atrophy should correlate with metatarsalgia. This study looked to determine the relationship between metatarsal fat pad thickness and metatarsalgia and the correlation between metatarsal fat pad thickness and patient-reported outcomes.

METHODS

We conducted a retrospective review of patients with metatarsalgia and those with foot or ankle osteoarthritis who had a nonweightbearing MRI performed between February 1, 2021, and March 1, 2023. Data collected included demographics, PROMIS scores, metatarsal fat pad thickness in the second and third rays of the affected foot, and thinnest area on coronal section, measured on MRI. Student t test was used to compare continuous variables, whereas the χ2 test was used to compare categorical variables. Multivariable linear regression models were used to control for potential confounding factors.

RESULTS

A total of 112 patients were included in this study. Patients with metatarsalgia were significantly more likely to have a lower body mass index (29.3 vs 32.0, P = .03) than patients with osteoarthritis, but this finding was not present when controlling for confounding variables. We found no significant difference in fat pad thickness between patients with metatarsalgia vs patients with foot or ankle osteoarthritis (P = .43). We found no correlation between metatarsal fat pad thickness and pain interference (P = .59), physical function (P = .64), or mobility (P = .94) PROMIS scores.

CONCLUSION

In this retrospective comparative study of a relatively small cohort we found no significant difference in metatarsal fat pad thickness for patients with metatarsalgia vs patients with foot and ankle osteoarthritis based on nonweightbearing MRI, and no association between metatarsal fat pad thickness and patient-reported outcomes.

LEVEL OF EVIDENCE

Level III, case control study.

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.

Magnetic resonance elastography of the plantar fat pads: Preliminary study in diabetic patients and asymptomatic volunteers

OBJECTIVE

To test the feasibility of applying the magnetic resonance elastography (MRE) technique to map the elastic modulus of the plantar fat pads in diabetic and nondiabetic subjects.

METHODS

A prototype MRE imaging apparatus was used to produce quantitative maps of the heel fat pad in a pilot study of 12 volunteers and 4 patients with diabetes with neuropathy. Anatomic images corresponding to MRE maps allowed precise selection of regions of interest in the fat.

RESULTS

Magnetic resonance elastograms of the heel fat pads were successfully created; mean measurements in the volunteers and the diabetic patients were 4.85 and 5.26 kPa, respectively.

CONCLUSION

It is feasible to perform MRE on the plantar fat pads and to produce elasticity maps. The trend toward stiffer fat pads, as demonstrated in patients with diabetes, suggests that the fat pads were qualitatively different. Magnetic resonance elastography offers great potential to investigate the mechanical properties of soft tissues in vivo noninvasively.

Optical plantar pressure analysis following internal fixation for displaced intra-articular os calcis fractures

Using optical pedobarography, the outcome of open reduction and internal fixation of displaced os calcis fractures was assessed. In 12 patients, well reconstructed heel contact widths and no reduction in heel-ground contact times were found. In conjunction with this, patients showed lateral deviation of the plantar pressures and load bearing, indicating that subtalar and calcaneocuboid joint function remained altered despite reconstruction. These findings could not be linked to the initial fracture severity or clinical outcome score.

Fractures of the calcaneus

Displaced fractures of the calcaneous are relatively common injuries that remain a treatment enigma. Virtually all aspects of the management of calcaneal fractures are a source of debate. Contemporary imaging, reduction, and fixation techniques attempt to improve the long term results of these injuries. The complex fracture fragments displace in predictable patterns. Meticulous surgical technique, restoration of extra- and intra-articular anatomy, and obtaining rigid fracture fixation are critical to obtaining satisfactory operative results. This article extensively reviews the controversies and summarizes the current opinions in the management of displaced calcaneal fractures.

Complications of intraarticular calcaneal fractures

The treatment of intraarticular calcaneal fractures remains a controversy in orthopaedics because of the associated complications. The authors present a systematic review of complications associated with calcaneal fractures. A MEDLINE search was conducted to review the results of operative and nonoperative treatment of calcaneal fractures to determine the most common complications reported. The following were reported to be the most common complications: swelling and fracture blisters, compartment syndrome, wound dehiscence and infection, neurovascular injury, tendon injury, heel pad pain and heel exostosis, malunion, and arthritis. Each complication was reviewed as to etiology, incidence, diagnosis, prevention, and treatment. Increased awareness of these complications and their prevention will aid the practitioner in decision-making and result in better treatment outcomes for this fracture.

Plantar fat pad atrophy: a cause of metatarsalgia?

The aim of this prospective study was to evaluate if atrophy of the plantar fat pad in splay-foot deformities was a major cause of metatarsalgia. A sonographic method of measuring the thickness of the plantar fat pad under the second and third metatarsal heads was developed. The method was tested on 25 volunteers and the intraobserver reliability was calculated to be 97.1% for the second metatarsal and 96.7% for the third metatarsal. Sonographic measurement of the plantar fat pad was then performed on 100 symptomatic feet Pain frequency and pain intensity were determined by using a verbal rating scale (VRS) and a visual analog scale (VAS). The intermetatarsal angle 1/2 was measured and then compared to the thickness of the fat pad for each patient. A correlation between the increase of the intermetatarsal angle and the decrease of the fat pad thickness could not be demonstrated (r = 0.041). The frequency of metatarsalgia did not correlate with a decrease of the thickness of the plantar fat pad under the second metatarsal head (t statistic: 1.978; Durbin-Watson test: 1.999; p value = .0507) and the third metatarsal head (t statistic: 3.199; Durbin-Watson test: 1.962; p value = .0019). The pain intensity showed a similar lack of correlation with the thickness of the plantar fat pad under the second metatarsal head (t statistic: 1.828; Durbin-Watson test: 2.365; p value = .0706) and the third metatarsal head (t statistic: 1.846; Durbin-Watson test: 2.371; p value = .0678). This study shows that a splay-foot deformity is not associated with a decrease of the thickness of the plantar fat pad. Furthermore, alterations of the thickness of the plantar fat pad are not relevant to the intensity and frequency of metatarsalgia.

The surgical dilemma of the malunited calcaneal joint depression fracture: the VAMC Miami experience

During the period of October 1985 through March 1995, 25 patients presented to the Veterans Affairs Medical Center, Miami with a chief complaint of chronic pain status post calcaneal joint depression fracture. Their acute injury was treated conservatively at this and various other institutions. Nine patients were managed conservatively with orthotics, University of California Biomechanics Laboratory braces (UCBLs), shoe modification, or prosthetics. Sixteen patients underwent hindfoot fusions. Good to excellent results were obtained in 15 of the 16 fusions. The remaining patient, having an isolated subtalar fusion, was later diagnosed with multiple sclerosis. Proper evaluation of the chronic pain patient is critical when mapping out an appropriate treatment plan. Hindfoot arthrodesis with soft tissue decompression is a successful tool in eliminating chronic pain due to malunited depression fractures.