METHODS: IV.

The primary aim of this study is to describe medium-term functional outcomes following first dorsal compartment decompression using a longitudinal incision in patients with de Quervain\'s syndrome. The secondary aims are to describe the improvement in health-related quality of life and patient satisfaction, and to determine the cost-effectiveness of this procedure. Pre- and postoperative QuickDASH, EQ-5D-5 L, and satisfaction scores were collected prospectively over five years. Paired data were available for 36 patients (90% at mean 32 months follow-up). The median QuickDASH score improved significantly from 50 to 9.1 (p < 0.01). Median EQ-5D-5L index scores improved from 0.65 preoperatively to 0.73 (p = 0.03). The satisfaction rate was 97% and there were no cases of superficial radial nerve injury or neuroma. The cost per quality-adjusted life year gained was £356 (€398; $449). First dorsal compartment release using a longitudinal incision results in a significant improvement in function, with high levels of patient satisfaction, and low complication rates. In addition, health economic analysis revealed that this is a cost-effective procedure for the treatment of de Quervain\'s syndrome. LEVEL OF EVIDENCE: III (cohort study).

Muscle and tendon variations in the forearm, wrist and hand are commonly reported in the anatomical and surgical literature. They are frequently the source of inflammatory conditions such as de Quervain\'s tenosynovitis or carpal tunnel syndrome. During academic dissection, a cadaver presented with bilateral, additional muscles running parallel to the abductor pollicis longus muscles (APL) in the extensor compartment of the forearm. Both additional muscles had two bellies, one proximal and one distal, with an intervening tendon. The proximal bellies were separate and distinct from the adjacent APLs. The tendons traversed the first dorsal compartments with the tendons of the APLs and the extensor pollicis brevis muscles (EPB). The distal bellies lay adjacent to the abductor pollicis brevis (APB) muscles in the thenar compartments, and inserted onto the volar base of the proximal phalanges of the thumbs. Following a thorough search of the literature, we determined that these additional muscles constitute a previously unreported variation. This report details the variation, compares it with other reported variations, presents the related embryology, and reviews the significance of this variation as it relates to inflammatory conditions and surgical procedures.

OBJECTIVE: To collate and synthesise the literature to provide estimates of the diagnostic accuracy of imaging modalities, and summarise the reported imaging findings associated with de Quervain\'s syndrome.
METHODS: A systematic search was performed in seven databases (MEDLINE, EMBASE, CINAHL, Cochrane Library, PROSPERO, Web of Science, and ProQuest Dissertations & Theses Global). Two reviewers independently performed screening, data extraction and quality assessment using a modified Quality Assessment of Diagnostic Accuracy Studies-2. Measures of diagnostic accuracy were summarised for different modalities and imaging findings.
RESULTS: Twenty-two studies were included, reporting ultrasound, magnetic resonance imaging, X-ray and scintigraphy findings. Reported imaging findings included sheath effusion, retinaculum thickening, subcutaneous oedema, tenosynovitis, hypervascularity, increased tendon size, bony erosion, apposition, calcific lesions and increased uptake on scintigraphy. The most commonly reported imaging findings related to the tendon sheath, with a sensitivity ranging from 0.45 to 1.00 for thickening, and 0.29 to 1.00 for effusions. The risk of bias of studies is largely unclear owing to a lack of reported detail.
CONCLUSIONS: The accuracy of imaging in the diagnosis of de Quervain\'s syndrome is unable to be determined because of the quality of the studies included. Ultrasound is the most frequently studied imaging modality and may be the modality of choice in clinical practice. Further research involving both symptomatic and asymptomatic participants and clear definitions of abnormal findings are required to better evaluate the effectiveness of imaging in identifying de Quervain\'s syndrome.

The purpose of this study was to find clinical or ultrasound characteristics that might predict the failure of conservative treatment in de Quervain\'s syndrome. A total of 42 ultrasound-guided injections have been performed in 41 patients after clinical and ultrasound examination. Patients were immobilized for 3 weeks with a spica splint cast, and clinically evaluated at 3 and 6 weeks and by phone call at the end of the study. Ultrasound showed a septum between the tendons of the first comportment in 34% of the wrists. At last follow-up (mean 15.6 months after the injection) ten patients (24%) had undergone surgery. When comparing ultrasound and clinical characteristics of the operated and non-operated wrists, we found that patients with a high baseline visual analogue scale, with all positive clinical tests and with a persistent intracompartmental septum, had a significantly higher risk of failure following conservative treatment.
METHODS: III.