The frondiform ligament sling: a sonographic landmark for injection into the sinus tarsi.

Localisation and injection of the sinus tarsi can be challenging, particularly for the less experienced musculoskeletal sonographer/practitioner. The inferior extensor retinaculum arises from the sinus tarsi in the form of three roots (medial, intermediate and lateral) which are collectively termed the frondiform ligament. This is readily identified on ultrasound and can be used as a reference point to aid the safe delivery of injectate material into the sinus tarsi. This article describes the technique and its anatomical basis.

MRI features of ERSA (exercise-related signal abnormality) lesions in professional soccer players.

OBJECTIVE: This study aims to describe the prevalence, anatomy and morphology of ERSA (exercise-related signal abnormality) lesions, a previously undescribed pattern of muscle signal changes on MRI in professional soccer players with suspected acute thigh muscle injury. METHODS: A multicenter retrospective review was performed of 287 MRIs of professional soccer players referred for suspected acute thigh injury from August 2017 to February 2020. MR images were reviewed for muscle signal abnormalities corresponding to a peritendinous ovoid region or a subfascial ring of faint increased signal on fluid-sensitive MR images. Imaging features including anatomical site, morphology, and craniocaudal length were recorded. Concomitant acute muscle injury was graded in accordance with the British Athletics Muscle Injury Classification (BAMIC). RESULTS: ERSA lesions comprising a peritendinous ovoid region, a subfascial ring, or both, were identified in 40 muscles across 31/287 studies (10.8%). These lesions had a mean length of 15.8 cm and were predominantly located in the proximal or mid-portions of muscles. Affected muscles were rectus femoris (n = 22), adductor longus (n = 11), semitendinosus (n = 6) and biceps femoris (n = 1). 21/31 studies (67.7%) had a BAMIC grade 1-4 injury in a separate muscle, which were largely (81%) in a separate anatomic compartment or contralateral. CONCLUSION: ERSA lesions were evident on MRI in 10.8% of our cohort of professional soccer players referred for suspected acute thigh muscle injury. Characteristic morphology and the longitudinal length (mean 15.8 cm) distinguish ERSA lesions from recognized patterns of acute muscle injury.

MRI findings of tibialis anterior friction syndrome: a mimic of tibial stress injury.

OBJECTIVE: To describe a distinct constellation of MRI demonstrated soft tissue abnormalities centred around the tibialis anterior tendon in a subset of patients presenting as suspected tibial stress injury. MATERIALS AND METHODS: A retrospective review was performed of the clinical and MRI imaging findings from 5 selected patients referred for MRI with suspected tibial stress injury. MRI studies at presentation of each case were systematically reviewed for peritendinous fluid, tibialis anterior tendon change, tibialis anterior muscle and myotendinous junction oedema, periosteal oedema over the tibia and tibial marrow oedema. RESULTS: All 5 cases were athletes (3 soccer players, 2 runners) of between 20 and 40 years of age. On MRI, all 5 cases demonstrated peritendinous fluid around an intact tibialis anterior tendon. This fluid was maximal at the junction of mid and distal thirds of the lower leg, and extended down to the superior extensor retinaculum, with a mean cranio-caudal length of 13 cm (range 8-17 cm). Associated oedema was present in the surrounding subcutaneous tissue, tibial periosteum and distal tibialis anterior musculotendinous junction. CONCLUSION: Peritendinous fluid around an intact tibialis anterior tendon over the mid-to-distal third tibia, with surrounding subcutaneous, periosteal and tibialis anterior myotendinous junction oedema is demonstrable on MRI in a subset of patients presenting as suspected tibial stress injury. A friction syndrome of tibialis anterior between the superior extensor retinaculum and the anterior tibia is proposed as the aetiology of this entity.

Technical report: dynamic assessment of plantar fasciitis and plantar fascia tears utilising dorsiflexion of the great toe.

Discrimination between plantar fasciitis and partial tears of the plantar fascia can be difficult on ultrasound given laxity of the plantar fascia in the region of its calcaneal insertion and anisotropy. Dynamic assessment with great toe dorsiflexion can improve visualisation of the proximal portion of the plantar fascia on ultrasound, by straightening the plantar fascia due to the windlass mechanism. This article describes the technique and its anatomical basis.

Efficacy of ultrasound-guided steroid injections for pain management of midfoot joint degenerative disease.

OBJECTIVE: To examine the efficacy of ultrasound (US)-guided injections for midfoot joint degenerative changes. MATERIALS AND METHODS: The US images and radiographs of 63 patients with midfoot joint degenerative changes were retrospectively reviewed. In those patients who had US-guided intra-articular steroid injection, the response to the injection was recorded by reviewing the 2-week pain diaries and clinical notes. Partial or complete pain relief was defined as a positive response and the same or increased level of pain as a negative response to the injection. RESULTS: Fifty-nine (59/63, 93.6%) patients with midfoot joint degenerative changes received US-guided injection. The majority of patients had a positive response up to 3 months post-injection (78.4% still experiencing pain relief at 2 weeks, 57.5% at 3 months and fewer than 15% of patients further than 3 months post-injection). The number of positive therapeutic responses did not differ significantly between patients with diagnostic and non-diagnostic response (p = 0.2636). CONCLUSIONS: US-guided intra-articular injections for midfoot degenerative changes can have a good therapeutic result in the majority of patients up to 3 months post-injection. Therapeutic response cannot be predicted by a positive diagnostic response.

Demodicosis in red-handed tamarins (Saguinus midas).

Two nonrelated but paired red-handed tamarins (Saguinus midas) presented with diffuse, multifocal, raised, nonpruritic, hyperkeratotic lesions on the appendages and face. Skin biopsies identified acarids and skin scrapings confirmed demodex-like mites. The animals were treated with ivermectin, at the endoparasite dose, which initially resulted in resolution of clinical signs; however, signs recurred after numerous treatments. After four treatments with amitraz dips, demodicosis lesions resolved.

Diagnosis and treatment of a fractured third phalanx in a Masai giraffe (Giraffe camelopardalis tippelskirchi).

A 10-yr-old male Masai giraffe (Giraffe camelopardalis tippelskirchi) presented with acute right forelimb lameness. Radiographs revealed a fracture of the medial claw of the distal phalanx penetrating into the distal interphalangeal joint. The giraffe was sedated while it was standing in a chute, and a wooden "hoof block" was applied to the lateral claw of the same limb. The animal was no longer lame 3 days after the procedure. Subsequent treatments included vitamin E, phenylbutazone, and glycosaminoglycans. For 7 wk it was maintained in a small holding yard on packed sand during the day and on deep sand during the night. The hoof block slowly wore down, and at 7 wk, it was placed back on concrete in the evening. At 8 wk, the block had completely worn off and the animal was no longer lame, but radiographs indicated minimal fracture healing. Radiographs performed at 7 mo indicated that there was still a radiolucent zone at the fracture line but calcification was evident at the margins of the fracture.

Immobilization of babirusa (Babyrousa babyrussa) with xylazine and tiletamine/zolazepam and reversal with yohimbine and flumazenil.

Twelve babirusa (Babyrousa babyrussa) (four females/eight males) were immobilized 30 times during a 4-yr interval. Significantly higher premedication and immobilizing doses were needed for females than for males (P < 0.05). An i.m. preanesthetic xylazine dose of 1.88 +/- 0.37 mg/kg (range = 1.20-2.12 mg/kg) was used for females and 1.22 +/- 0.16 mg/kg (range = 0.82-1.43 mg/kg) for males. After xylazine, the animals were induced with i.m. tiletamine/zolazepam; females received 2.20 +/- 0.47 mg/kg (range = 1.78-3.33 mg/kg) and males received 1.71 +/- 0.34 mg/kg (range = 1.08-2.05 mg/kg). Anesthesia was reversed with yohimbine (0.14 +/- 0.03 mg/kg; range = 0.07-0.20 mg/kg) and flumazenil (1 mg flumazenil/20 mg zolazepam) either i.m. or i.v. This anesthetic combination produced smooth induction, good relaxation, and sufficient immobilization to perform routine diagnostic and therapeutic procedures (venipuncture, hoof and tusk trims, transportation, radiographs, ultrasound examination, weight determinations, and skin biopsies). Supplemental ketamine HCl or isoflurane was administered to two animals to effectively deepen or prolong the anesthetic plane, with no resultant adverse effects.

Brodifacoum toxicity and treatment in a white-winged wood duck (Cairina scutulata).

A captive white-winged wood duck (Cairina scutulata) with bilateral epistaxis and anemia (packed cell volume = 16%) was treated with injectable and oral vitamin K1 and transfused with 40 ml whole blood. Brodifacoum was detected in blood at 0.002 ppm. The bird made an uneventful recovery. This report illustrates the risk of anticoagulant pest control products in a zoological setting.

Augmentation of autograft using rhBMP-2 and different carrier media in the canine spinal fusion model.

This study evaluated the use of recombinant human bone morphogenetic protein (rhBMP-2) with various types of carrier media, and the effect of rhBMP-2 as an adjunct to autogenous iliac crest bone graft in the canine spinal fusion model. BMP induces mesenchymal cells to differentiate into cartilage and bone. The recent availability of rhBMP-2 has created the opportunity to evaluate this material's properties in augmenting autogenous bone graft in spinal fusion. Currently, the most appropriate type of carrier media for rhBMP-2 is undetermined. Bilateral intertransverse spinal fusions were performed on six canine lumbar spines at L1-L2, L3-L4, and L5-L6, using autogenous posterior iliac crest bone graft at each level, creating a total of 18 segmental fusion sites. All 18 sites were then randomly assigned to one of six fusion methods: autogenous bone graft (ABG) alone, ABG + rhBMP-2, ABG + collagen (Helistat) "sandwich" + rhBMP-2, ABG + collagen (Helistat) morsels + rhBMP-2, ABG + polylactic/glycolic acid sponge (PLGA) sandwich + rhBMP-2, and ABG + open-pore polylactic acid morsels + rhBMP-2. Each material was evaluated for ease of handling and application at the index surgery. The animals underwent computed tomography (CT) scanning of the lumbar fusion sites after 8 weeks. Volumetric measurements of total fusion mass at each level were performed using two-dimensional CT scan slices and a volumetric program supplied by the Siemens Medical System. The animals were killed after imaging studies. The lumbar spine fusion sites were evaluated for integrity of the fusion mass, both visually and with manual mechanical stressing. Crossover of the fusion mass to adjoining levels was also evaluated. Histologic evaluation of all fusion sites was performed. The addition of rhBMP-2 significantly increased bone graft volume as noted on CT scan. Carrier that could be mixed with morselized bone graft offered easier handling and application and all spine segments fused. Polylactic/glycolic acid (PLGA) sites were associated with a greater incidence of voids within the fusion mass. No significant difference in carrier media for rhBMP-2 could be determined. However, PLGA was associated with a higher rate of fusion mass void formation. rhBMP-2, when added to autograft, significantly increased the volume and the maturity of the resulting fusion mass.

Observations on a new non-invasive monitor of skin blood flow.

1. A 'tissue perfusion monitor' (TPM) to non-invasively provide an index of skin blood flow (SkBF) has been developed; it employs photoelectric plethysmographic principles to measure changes in the nett flux of red blood cells in superficial microvasculature. 2. The 'tissue perfusion index' (TPI) varies in proportion to SkBF, provided local haemoglobin concentration does not change significantly. TPI of humans and experimental animals has been shown to indicate reliably, well established phenomena such as decreased SkBF in response to mechanical restriction, cold or Valsalva's manoeuvre, or increased SkBF in response to heat, acetylcholine, sodium nitrite or local nerve blockade. 3. SkBF in sheep was varied between 1 and 156 mL/100g per min as measured with radioactive microspheres. Simultaneous measurements were made using the TPM and four laser-Doppler instruments. The TPI yielded a correlation coefficient of 0.938, and when data were expressed as percentage change, the regression line did not differ significantly from the line of identity and the root-mean-square-error was 6.2%. Data for the laser-Doppler indices of SkBF were, respectively, 0.549-0.786, highly significant deviations in slopes, and 13.6-16.7%. 4. Thus, the TPI is a reliable index of changes in SkBF. Compared with some other available instruments, the TPM is more precise; it is also less sensitive to movement artefact, can be completely portable by battery operation, probes can be multiplexed to a single meter and it is likely to be much less expensive than current lasers. 5. Applications include, for example, experimental investigations of SkBF in man and animals, clinical uses such as evaluation of the efficacy of regional nerve blockade or of circulatory restitution after reconstructive surgery, and clinical tests of neurovascular function.

In vitro noradrenaline accumulation by sheep skin: partial characterization and localization.

Previous studies from this laboratory have implicated the sympathetic neurotransmitter noradrenaline (NA) in regulation of wool growth. The current study was undertaken to investigate [3H]NA accumulation and its localization by Merino skin, and to determine the effects of gonadal and glucocorticoid steroids on such uptake. The presence of an active uptake system was demonstrated and the process was partially characterized in terms of its magnitude, time course, concentration dependence and requirement for various nutrient and ionic factors. The uptake was seen to occur predominantly into cocaine- and 6-hydroxydopamine-sensitive sites in skin from various body regions of Merino sheep. None of three steroids tested in vivo or in vitro was seen to influence the uptake process. These results do not enable us to correlate the observed [3H]NA uptake process with the previously reported effects of NA on wool growth.