A 54-year-old man originally presented to his primary care physician in January 2019 complaining of two painful swellings in the arch of his left foot. An ultrasound scan (USS) examination was requested. Two well-defined hypoechoic lesions arising from the distal portion of the left plantar fascia were described. The distal lesion measured 13.5 mm in length x 5.2 mm in width (Figure 1) the proximal lesion measured 7.9 mm x 2.8 mm (Figure 2). No significant intra-substance vascularity was seen. The remaining plantar fascia was normal. Appearances were in keeping with LD.
The patient had a history of nicotine use (15-20 cigarettes a day), essential hypertension and chronic lumbar region pain. He had stable epilepsy and was recovering from alcohol abuse. His current medication was lisinopril 20 mg od, gabapentin 400 mg tds, codeine/paracetamol 30/500 mg combination prn and sodium valproate 500 mg tds. The patient had concomitant palmar Dupuytren's disease on the left hand with fascial nodules and contracture of the fourth finger. There were no known allergies and no relevant family or surgical history.
Following the results of the USS organised in primary care, he was seen by our service in February 2019 complaining of searing pain on the medial longitudinal arch of the left foot of 6 months duration. He described the pain as severe and debilitating and rated his discomfort at 9/10 on a visual analogue scale (VAS). On examination he had two firm, sub-epidermal swellings in the distal-medial aspect of the arch associated with the central slip of the plantar fascia. Normal neurovascular status was observed. His symptoms had worsened over the previous 3 months, aggravated by activity and weightbearing. Prior treatment included accommodative footwear and orthoses. Intralesional CSI in combination with a fenestration/needling was recommended and informed, written consent was obtained, backed up with a patient information leaflet. Written permission to use images for publication was obtained.
One week following initial consultation, the patient attended for their planned procedure. As the patient presented with significant pain, the procedure was performed under tibial nerve block, performed at the level of the ankle with 3 mL of 0.75% ropivacaine under aseptic technique. The injection sites were prepared with a chlorhexidine gluconate 2%/isopropyl alcohol 70% mix. A sterile cover was placed on the ultrasound probe and sterile coupling gel utilised. The ultrasound probe was placed plantarly and longitudinal to the lesion to allow for a medial injection approach. A mixture of 20 mg (40 mg/mL) triamcinolone acetonide and 1 mL of mepivacaine hydrochloride was deposited with intralesional fenestration (20-30 repeated passes with multiple micro-deposition sites from proximal to distal and medial to lateral without removing the needle from the skin) initially to the distal lesion followed by an identical preparation administered to the proximal lesion. The whole of the fibroma is targeted but avoiding being too superficial (skin atrophy), or too deep (reduced effectiveness). A sudden loss of resistance during the injection indicates that the lesion has been penetrated too deeply or adjacent to the lesion.
Both injections were performed under ultrasound guidance with confirmation of intralesional deposition. An extremely small amount of perilesional injectate leakage was noted. Importantly, a 2.5-mL Luer lock syringe with a 23 gauge/25 mm needle was utilised as experience has shown the presence of pressure when injecting a solid mass which can cause de-coupling of the syringe from needle. No significant bleeding was associated with the procedure. A simple self-adhesive dressing was applied to the injection sites. Post procedure advice included rest and foot elevation for the remaining day. The patient could return to daily living activities the following day but was to refrain from impact activity, for example, sports until follow-up at 6 weeks post procedure. As well as the usual post-injection advice, particular reference to the small risk of fascial rupture was made.
No significant beneficial effect was witnessed at the 6-week review, as such, a second injection was recommended. Eight weeks following the original procedure, the same protocol as described above was undertaken. In this instance, palpation-guided injection and fenestration was undertaken (Figure 3). Six weeks post the second procedure (total 14 weeks post index procedure), a significant reduction in the size and rigidity of both lesions was reported clinically. A repeated VAS was 2/10.
For purposes of audit, the patient was reviewed at 12 months post procedure and a further USS examination was undertaken showing a significant regression of both nodules: the distal nodule to 6 mm x 1.9 mm (Figure 4) and the proximal nodule to 2.4 mm x 1.2 mm (Figure 5). During this period, the patient had no regression of symptoms. A VAS completed at 12 months was 0/10. Clinically, the proximal nodule was no longer palpable or visible, the distal nodule remained palpable but not visible. No pain was felt on palpation. The patient remarked they were unable to feel any nodule on ambulation. No adverse signs or symptoms were reported.