Self-reported foot strike patterns and sonographic evidence of Achilles tendinopathy in asymptomatic marathon runners.

It is unknown whether ultrasound findings and symptoms of Achilles tendinopathy in runners correlate with foot strike patterns. We aimed to examine the relationships among Achilles tendon ultrasound findings in runners with or without Achilles tendinopathy, their foot strike patterns, and their training regimens. We recruited marathon runners 18 years of age or older with no history of Achilles tendon pain or surgery participating in the 2018 DONNA Marathon. Participants completed surveys and underwent Achilles tendon sonographic evaluations and were categorized by foot strike patterns. Seventy-nine runners were included; 22 (28%) with forefoot, 30 (38%) midfoot, and 27 (34%) hindfoot strike patterns. Foot strike pattern was not associated with tendon hyperaemia (P = 1.00) or hypoechogenicity (P = .97), and there was no association of cross-sectional area of the Achilles tendon with peak weekly distance while training. Sonographic characteristics of Achilles tendinopathy did not correlate with foot strike patterns or training regimens. Although not statistically significant, it is worth noting that cross-sectional area was 1 mm2 larger per every 1 kg/m2 increase in body mass index.

The effect of magnification on sonographically measured nerve cross-sectional area.

INTRODUCTION: The primary aim of this investigation was to determine whether use of write-zoom magnification affects sonographically determined cross-sectional area (CSA) of peripheral nerves. METHODS: CSAs of the median (MN) and posterior interosseous (PIN) nerves were measured in 22 limbs from 11 asymptomatic volunteers using both standard imaging and write-zoom magnification. CSA measurements were repeated on the same images 1 week later. RESULTS: The average CSA of write-zoomed images for the MN was significantly larger at both measurement sessions (week 1: 11.1 mm(2) write-zoom vs. 10.0 mm(2) standard, P = 0.019; week 2: 11.8 mm(2) vs. 10.4 mm(2), P = 0.023). Similar differences were noted for the PIN (week 1: 2.3 mm(2) vs. 1.9 mm(2), P = 0.002; week 2: 2.5 mm(2) vs. 1.9 mm(2), P = 0.001). CONCLUSIONS: Write-zoom magnification may significantly increase the measured CSA of peripheral nerves. These changes appear to be more substantial when smaller nerves are measured.

Sonographic visualization of the first branch of the lateral plantar nerve (baxter nerve): technique and validation using perineural injections in a cadaveric model.

OBJECTIVES: The primary purpose of this investigation was to document the ability of high-resolution sonography to accurately identify the first branch of the lateral plantar nerve (FBLPN) using sonographically guided perineural injections in an unembalmed cadaveric model. METHODS: single experienced operator completed sonographically guided perineural FBLPN injections in 12 unembalmed cadaveric specimens (6 right and 6 left) obtained from 10 donors (5 male and 5 female) aged 47 to 95 years (mean, 71 years) with an average body mass index of 24.2 kg/m(2) (range, 17.2-31.6 kg/m(2)). All injections were completed using 22-gauge, 38-mm stainless steel needles to deliver 1 mL of 50% diluted colored latex adjacent to the FBLPN in the abductor hallucis-quadratus plantae (AH-QP) interval. Six injections were completed using a cart-based ultrasound (US) machine and a 17-5-MHz transducer, and 6 were completed using a portable US machine and a 12-3-MHz transducer. Nerve conspicuity was graded on a 4-point scale (1, poor; 4, excellent). After a minimum of 24 hours, study coinvestigators dissected each specimen to assess injectate placement. RESULTS: All 12 injections accurately placed latex onto the FBLPN within the AH-QP interval, with 11 of 12 (91%) resulting in complete nerve coverage. Proximal latex overflow to the lateral plantar nerve occurred in 82% of cases (10 of 12). The average distance between the plantar fascia and injected latex was 1.2 cm (range, 1.0-1.75 cm). No vascular injury was seen in any specimen. The average nerve conspicuities were 3.7 (range, 3-4) using the cart-based US machine and 1.8 (range, 1-4) using the portable US machine. CONCLUSIONS: Sonographic visualization of the FBLPN in the AH-QP interval is feasible and should be considered for diagnostic and therapeutic purposes in patients presenting with chronic or atypical heel pain syndromes. Further clinical experience should refine the role of FBLPN sonography and explore the utility of sonographically guided diagnostic and therapeutic FBLPN perineural injections.

Sonographically guided deep plantar fascia injections: where does the injectate go?

OBJECTIVES: To determine the distribution of sonographically guided deep plantar fascia injections in an unembalmed cadaveric model. METHODS: A single experienced operator completed 10 sonographically guided deep plantar fascia injections in 10 unembalmed cadaveric specimens (5 right and 5 left) obtained from 6 donors (2 male and 4 female) aged 49 to 95 years (mean, 77.5 years) with a mean body mass index of 23.2 kg/m(2) (range, 18.4-26.3 kg/m(2)). A 12-3-MHz linear array transducer was used to direct a 22-gauge, 38-mm stainless steel needle deep to the plantar fascia at the anterior aspect of the calcaneus using an in-plane, medial-to-lateral approach. In each case, 1.5 mL of 50% diluted colored latex was injected deep to the plantar fascia. After a minimum of 72 hours, study coinvestigators dissected each specimen to assess injectate placement. RESULTS: All 10 injections accurately placed latex adjacent to the deep side of the plantar fascia at the anterior calcaneus. However, the flexor digitorum brevis (FDB) origin from the plantar fascia variably limited direct latex contact with the plantar fascia, and small amounts of latex interdigitated with the FDB origin in 90% (9 of 10). In all 10 specimens, latex also covered the traversing first branch of the lateral plantar nerve (FBLPN, ie, Baxter nerve) between the FDB and quadratus plantae muscles. No latex was found in the plantar fat pad or plantar fascia in any specimen. CONCLUSIONS: Sonographically guided deep plantar fascia injections reliably deliver latex deep to the plantar fascia while avoiding intrafascial injection. However, the extent of direct plantar fascia contact is variable due to the intervening FDB. On the contrary, the traversing FBLPN is reliably covered by the injection. Deep plantar fascia injections may have a role in the management of refractory plantar fasciitis, particularly following failed superficial perifascial or intrafascial injections, in cases of preferential deep plantar fascia involvement, or when entrapment/irritation of the distal FBLPN is suspected.