Perfusion of the abductor digiti quinti after transfer on a neurovascular pedicle

Low Median Nerve Transfers (Opponensplasty)

Opposition is the placement of the thumb opposite the fingers into a position from which it can work. This motion requires thumb palmar abduction, flexion, and pronation, which are provided by the abductor pollicis brevis, flexor pollicis brevis (FPB), and opponens pollicis. In the setting of a median nerve palsy, this function is typically lost, although anatomic variations and the dual innervation of the FPB may prevent complete loss at times. There are multiple well described and accepted tendon transfers to restore opposition, none of which have been proven to be superior to the others.

Abductor digit minimi opponensplasty: technique, modifications, and measurement of opposition

The abductor digiti minimi is one of several muscles described as transfers for restoration of thumb opposition, a critically important function. This operation, also known as the Huber opponensplasty, is most commonly used for reconstruction of opposition in children with type 2 or 3a thumb deficiency, when it is often combined with Z-plasty of the thumb-index web space and metacarpophalangeal ulnar collateral ligament reconstruction. In our experience this operation reliably improves thumb opposition for children with this thumb deficiency.

Congenital failure of formation of the upper limb

This article provides an overview of the various classification systems for radial longitudinal, central longitudinal, and ulnar longitudinal deficiencies. It looks specifically at radius deficiency, hypoplastic thumb, index finger pollicization, narrowed thumb web, forearm-elbow deformities, and hand abnormalities. Various surgical approaches to these conditions and their results are explored. The authors conclude that longitudinal failure of formation deformities comprises a substantial portion of the anomalies of the upper limb. Although much of the past and current congenital hand literature has been devoted to these conditions, they continue to be a reconstructive challenge to hand surgeons involved in their care.

Postoperative blood flow monitoring after free-tissue transfer by means of the hydrogen clearance technique

The hydrogen clearance technique was introduced for monitoring postoperative blood flow after free-tissue transfer in this prospective clinical study. This technique allows unlimited repeatable quantitative measurements of tissue blood flow in milliliters per minute per 100 gm of tissue at any site including buried flaps. In this study a real-time blood flow measuring system (Ameflow, Ameda, Switzerland) was employed. Two thousand eight hundred and twenty-three blood flow measurements were carried out on 72 free-tissue transfers, which were performed on 71 patients. Nine of these 72 flaps showed vascular complications (12.5 percent), including arterial thrombosis in 6.9 percent (n = 5), hematoma in 4.2 percent (n = 3), and venous thrombosis in 1.4 percent (n = 1). Complications as well as uneventful postoperative cases were monitored correctly by the hydrogen clearance technique in all cases, reaching sensitivity and specificity values of 1.0 for this technique in our study. Furthermore, all complications could be detected earlier by the hydrogen clearance technique than by clinical monitoring alone, which allowed flap salvation in 7 of 9 cases and a resulting permanent failure rate of free-tissue transfer of 2.8 percent (n = 2). From our data we conclude that the hydrogen clearance technique is a promising tool for postoperative blood flow monitoring after free-tissue transfer. For experimental pathophysiologic and pharmacologic studies of tissue blood flow in flaps, further evaluation of our measuring device including comparative studies with other established techniques is highly recommended.

Anatomic study of the ulnar nerve and related vascular anatomy at Guyon's canal: a practical classification system

Thirty-one fresh adult upper extremities were microdissected in order to delineate the regional anatomy of the ulnar nerve and artery at the wrist. Two patterns of division of the ulnar nerve trunk were identified: A and B. Three patterns of hypothenar muscle innervation-type 1, 2, and 3- and two patterns of vascular supply to the hypothenar musculature-type 1 and 2-were also identified. Pattern A occurred in 25 of the specimens where the ulnar nerve bifurcated into a main sensory trunk and a motor branch. Pattern B occurred in 6 of the specimens where the ulnar nerve trifurcated into two common digital sensory branches and a motor branch. The hypothenar innervation patterns were categorized as follows: type 1, 10 cases, single branch; type 2, 14 cases, two branches; and type 3, 7 cases, three or more branches. The patterns of hypothenar vascular supply were categorized as follows: type 1, 17 cases, major vascular arcade passing from the ulnar artery to the hypothenar musculature palmar to the entire ulnar nerve; type 2, 6 cases, arcade passing palmar to the motor portion of the nerve only; and type 3, 8 cases, no axial arterial supply identified. In no specimen did we identify a deep branch of the ulnar artery coursing with the deep motor branch of the ulnar nerve and contributing to a deep palmar arterial arcade. This classic description of a deep palmar arterial arch, we believe, is not valid, due to the mistaken identity of hypothenar arterial branches.

Measurements of tissue blood flow by the hydrogen clearance technique (HCT): a comparative study including laser Doppler flowmetry (LDF) and the Erlangen micro-lightguide spectrophotometer (EMPHO)

The purpose of this study was to compare the hydrogen clearance technique (HCT) with two different, well-established techniques, i.e., the laser Doppler flowmetry (LDF) and the Erlangen micro-lightguide spectrophotometer (EMPHO), for tissue blood flow measurements in an experimental setting. For the animal experiments, we chose a rat model for arterial and venous flap thrombosis, using the epigastric groin flap. Forty male dark Aguty rats were included in the study. The animals were divided into eight groups, each with a different vascular thrombotic model. HCT was used to collect 1,467 measurements, and 2,934 graphs were recorded; 27 measurements (54 graphs) had to be discarded due to faulty electrode placements and electronic noise. In 19 of the 27 discarded measurements the cause of failure was moving of the awaking animal with disruption of the decay signal. The LDF and EMPHO measurements were performed continuously during each measuring phase. Simple and multiple linear regression and paired t-tests were used to compare the three techniques. The reproducibility of registered blood flow values in phases 1, 3, 6 and 7 varied between 7.8% and 13.6% which is in about the same range as LDF and EMPHO. We could not find a significant difference between the three techniques in this regard. The correlation coefficient for HCT and LDF was r = 0.89. For HCT and EMPHO we found r = 0.67. Sensitivity and specificity values for HCT were both 1.0 in detecting arterial and venous flap thrombosis; for LDF we found values of 0.89 and 0.92, respectively. Sensitivity and specificity values for EMPHO were 0.92 and 0.95, respectively. After careful evaluation of three different techniques (HCT, LDF, and EMPHO) for measurements of local tissue blood flow we came to the conclusion that HCT must be favoured as a reliable tool for quantitative measurement of local tissue blood flow and early diagnosis of arterial and venous flap thrombosis.