Finger abduction as a novel function of the extensor digitorum brevis manus muscle

A 25-year-old female presented with a chronic scapho-lunate ligament injury with development of carpal instability requiring reconstruction. During a standard dorsal longitudinal mid-line approach to the carpus, an extensor digitorum brevis manus (EDBM) muscle was found taking its origin from the dorsal wrist capsule overlying the lunate with innervation from the posterior interosseous nerve (PIN). Electrical stimulation of the muscle belly demonstrated abduction of the middle finger. The EDBM is a rare anatomical variant of the extensor compartment of the wrist and may be encountered during surgical approaches. Where possible these variant muscles should be carefully dissected off underlying structures, preserved and repaired at the conclusion of a procedure to ensure no perceived functional deficit to the patient. We present a case of a previously undescribed EDBM muscle function of pure finger abduction with no extension and a surgical technique of preserving its origin. We propose that the middle finger variant of the EDBM should be re-named the extensor digitorum brevis medius to reflect our findings.

Snapping thumb: a rare case of stenosing tenosynovitis of the extensor pollicis longus tendon

Tenosynovitis of the extensor pollicis longus (EPL) is rarely reported in patients without rheumatoid arthritis but may lead to thumb snapping as a consequence of EPL stenosing tenosynovitis.This case presents painful thumb snapping that developed after a wrist trauma and repetitive loading. Ultrasound and MRI were used as diagnostic tools, before surgical release of the EPL in the third extensor compartment was performed. Neither EPL tenosynovitis nor thumb snapping were found at follow-up.

Lunate Revascularization With Temporary Internal Radiocarpal Spanning Fixation for Kienböck Disease

Background The goal in the treatment of stages II and III Kienböck disease is to restore lunate vascularity and halt the progression of avascular necrosis. Methods We report the outcomes for patients with stages II and III Kienböck disease treated with fourth extensor compartment artery vascularized bone grafting and temporary radiocarpal spanning internal fixation. Nine patients with a mean age of 28.8 years were included. Mean clinical and radiographic follow-up were 4.9 and 1.9 years, respectively. Results Six patients had no change in Lichtman stage, 2 patients regressed 1 stage, and 1 patient progressed 1 stage. Mean postoperative quick disabilities of the arm, shoulder, and hand (QuickDASH) was 17.4. Mean postoperative visual analogue pain scale (VAS) was 1.8. Patients under age 25 trended toward improved clinical outcomes compared with patients over age 25. Two patients, aged 33 and 65, underwent proximal row carpectomy at a mean 30.5 months postoperatively. Conclusions In conclusion, the use of local vascularized bone graft with temporary internal radiocarpal spanning fixation provides a treatment option with outcomes comparable to existing literature with benefits inherent to internal immobilization.

Shear wave elastography detects novel imaging biomarkers of aromatase inhibitor–induced joint pain: a pilot study

Aim: To determine whether differences in joint and tendon stiffness as measured by ultrasound shear wave elastography are present in breast cancer patients with aromatase inhibitor- associated arthralgias compared to age-comparable healthy control women. Methods: Postmenopausal women with stage I–III breast cancer who were taking adjuvant aromatase inhibitors and complained of joint pain were enrolled (n = 6). Postmenopausal women with no history of breast cancer, hormone treatment, or joint pain served as controls (n = 7). All subjects had bilateral hands and wrists evaluated by gray-scale and power Doppler ultrasound, and shear wave elastography ultrasound. Results: Patients with AI-associated arthralgias had significantly stiffer tendons than controls in the 1st extensor compartment (long axis; p = 0.001), 4th extensor compartment (long axis; p = 0.014), 3rd metacarpophalangeal joint (p = 0.002), the pooled values of the extensor compartments, both long (p = 0.044) and short axes (p = 0.035), and the pooled values for the metacarpophalangeal joints (p = 0.002). On ultrasound, the patients (but not controls) presented with hyperemia and increased tenosynovial fluid in the flexor and extensor tendon sheaths, and the median nerves were symptomatic and bifid; however, these differences were not statistically significant. Conclusions: This is the first study to identify increased tendon stiffness as a putative physiological characteristic of aromatase inhibitor–associated arthralgias. Future studies should determine whether increased tendon stiffness is a risk factor for the development of aromatase inhibitor–associated arthralgias, or a result of aromatase inhibitor treatment.

Duplication of the Extensor Pollicis Longus and Index Extensor Digitorum Communis: Report of a Novel Anomaly and Review of Literature

Accessory extensor tendons in the hand are not rare, usually asymptomatic, and recognized incidentally during elective surgery or cadaveric dissection. This report describes a novel case of symptomatic duplication of accessory extensor tendons to both the thumb and the index finger causing a painful dorsal wrist tenosynovitis. Excision of the accessory tendons with decompression and tenosynovectomy of the fourth extensor compartment alleviated the patient’s symptoms without compromising motion or function.

Dual-incision minimally invasive fasciotomy of the anterior and peroneal compartments for chronic exertional compartment syndrome of the lower leg

To evaluate the risk of iatrogenic injury when using a dual-incision minimally invasive technique to decompress the anterior and peroneal compartments of the lower leg. Forty lower extremities from 20 adult cadavers, embalmed with Thiel’s method, were subject to fasciotomy of the anterior and peroneal compartment using a dual-incision minimally invasive fasciotomy. The first incision was made 12 cm proximal to the lateral malleolus to identify and protect the superficial peroneal nerve (SPN). The second incision was made at the mid-point of the Fibula (half-way between the fibular head and the lateral malleolus). Release of the anterior and peroneal compartments was successful in all specimens. Two nerve injuries of the superficial peroneal nerve were reported. More precisely, in these cases the medial dorsal cutaneous nerve got injured during the fascial opening of the extensor compartment. Two incision minimally invasive fasciotomy to decompress the anterior and peroneal compartments of the lower leg appears to be safe with regard to the results of this study.