Ultrasound-Guided Steroid Injection of the Pisotriquetral Joint: A Multidisciplinary Effort

Ultrasound-guided injection of the pisotriquetral joint: technique and case series

PURPOSE

To describe our techniques for ultrasound-guided injection of the pisotriquetral joint (PTJ), and to report our experience in a case series.

METHODS

Between 7/1/14 and 11/30/20, we performed 42 injections in 33 patients with ulnar-sided wrist pain, referred by clinicians who suspected the PTJ as the pain generator. There were 16 males and 17 females, average age 46.7 years. The patients were positioned in one of five ways: sitting with the hand maximally supinated; sitting with the hand maximally pronated; supine with the elbow flexed across the chest and the ulnar aspect of the wrist facing upward; supine with the elbow flexed, the arm externally rotated, and the ulnar aspect of the wrist facing upward; prone with the symptomatic hand at their side and the ulnar aspect of the wrist facing upward.

RESULTS

The procedures were performed by any of twelve fellowship-trained musculoskeletal radiologists. Fifteen patients reported immediate relief of symptoms, including 6 patients whose pisotriquetral joints were normal sonographically. Four patients underwent subsequent surgical excision of their pisiforms and the fifth underwent arthroscopic debridement of the pisotriquetral joint.

CONCLUSION

Ultrasound is a facile imaging modality for guiding pisotriquetral injections, which may be accomplished with a variety of patient positions and injection techniques.

(4-Aminopyridine)-PLGA-PEG as a Novel Thermosensitive and Locally Injectable Treatment for Acute Peripheral Nerve Injury

Traumatic peripheral nerve injury (TPNI) represents a major medical problem that results in loss of motor and sensory function, and in severe cases, limb paralysis and amputation. To date, there are no effective treatments beyond surgery in selective cases. In repurposing studies, we found that daily systemic administration of the FDA-approved drug 4-aminopyridine (4-AP) enhanced functional recovery after acute peripheral nerve injury. This study was aimed at constructing a novel local delivery system of 4-AP using thermogelling polymers. We optimized a thermosensitive (4-AP)-poly(lactide-co-glycolide)-b-poly(ethylene glycol)-b-poly(lactide-co-glycolide) (PLGA-PEG-PLGA) block copolymer formulation. (4-AP)-PLGA-PEG exhibited controlled release of 4-AP both in vitro and in vivo for approximately 3 weeks, with clinically relevant safe serum levels in animals. Rheological investigation showed that (4-AP)-PLGA-PEG underwent a solution to gel transition at 32 °C, a physiologically relevant temperature, allowing us to administer it to an injured limb while subsequently forming an in situ gel. A single local administration of (4-AP)-PLGA-PEG remarkably enhanced motor and sensory functional recovery on post-sciatic nerve crush injury days 1, 3, 7, 14, and 21. Moreover, immunohistochemical studies of injured nerves treated with (4-AP)-PLGA-PEG demonstrated an increased expression of neurofilament heavy chain (NF-H) and myelin protein zero (MPZ) proteins, two major markers of nerve regeneration. These findings demonstrate that (4-AP)-PLGA-PEG may be a promising long-acting local therapeutic agent in TPNI, for which no pharmacologic treatment exists.