Anatomical Variations of the Neurovascular Structures of the Hand and the Clinical Significance

The most essential prerequisite for hand surgeons is a comprehensive knowledge of variations in the arterial architecture of the hand. There are two well designed arterial arches, superficial palmar arch (SPA) and the deep palmar arch (DPA) situated superficial and deep to flexor tendons and lumbrical muscles respectively. Even though both are formed by the contribution of radial and ulnar arteries, variations are numerous and frequent in SPA that attracts the attention of surgeons. During the routine dissections we found a rare variation in the structural architecture of SPA which was formed by anastomosis of the radial - median and ulnar arteries. This triarterial combination of SPA is an advantage in reconstructive hand surgeries, microvascular surgeries and radial artery harvesting for Coronary artery bypass graft. Presence of incomplete SPA is dangerous to tackle surgically. Screening is essential to know the exact arterial pattern for successful hand surgeries without postoperative complications.

Background: Superficial palmar arterial arch is a dominant vascular structure of the palm. It is defined asan arterial arcade, formed by superficial branch of the ulnar artery and completed on lateral side by the superficial palmar branch of the radial artery or Arteria radialis indicis or Arteria princeps pollicis or arteria nervimediana. Variations can occur in the vessels contributing to the formation of superficial palmar arch (SPA). Aim: The main objective of the study is to know the formation of superficial palmar arch and different types of formation with an emphasis on its clinical relevance. Result: The present study was conducted on 50 specimens, followingthe classification of Coleman and Anson. We found complete arch of type A in 43 hands (86%) and of type B in 3 hands (6%). In this study incomplete arch was seen in 4 hands (8%, 1 right and 3 left), persistent median artery type H supplying the radial side of the palm and digits was seen in only one hand (2%). Conclusion: Knowledge of such variations is of immense help for microvascular surgeons, plastic surgeons and orthopaedicians to bring a better outcome in their surgical procedures. Also, it will be helpful for cardiovascular surgeons to carryout radial artery harvesting procedures for the purpose of Coronary Artery BypassGrafting.

Equally, the sensitive anastomosis between the median nerve (MN) and the ulnar nerve (UN) in the hand, and the superficial palmar arch (SPA) variants have been broadly publicised to be of clinical and surgical significance. In this study, we aim to analyse metrically, topographic relations between this nervous anastomosis to both the SPA and the transverse carpal ligament. Material and methods 30 10% formalin-fixed adult human cadavers' hands, readily available at the Department of Morphology of Santa Casa de Sao Paulo School of Medical Sciences, have been dissected in order to evaluate primarily, the SPA formation pattern classified in accordance to five types proposed by Loukas et al, 2005. Deep dissection henceforth ensued in 15 specimens to expose the MN and UN ramus and their potential coupling in four patterns as suggested by Meals & Shaner, modified by Bas & Kleinert, 1999. Results Amongst our samples, the SPA variants distribution has been of: 11 (36.7%) type S-I, 13 (43.4%) type S-II, 1 (3.4%) type S-III, 1 (3.4%) type S-IV and 4 (13.4%) S-V. MN and UN distal anastomosis has been found in four hands, three type-I, and one type-III: type-I cases ran profoundly to the APS, and type-III mean distance to the SPA was </a>1.6 cm distally. Conclusion We have been able to assess a topographic relation between the SPA and the sensitive anastomosis in the hand potentially valuable to clinics and surgery; nonetheless, we encourage forward study in this regard.

The superficial palmar arch (SPA) and its contributing arteries are highly variable. The palmar type of median artery (PMA) can be involved in the formation of the SPA by replacing the superficial palmar branch of the radial artery (RA) or the ulnar artery (UA). The present study was undertaken to investigate the presence of the PMA and its contribution in the formation of SPA in 42 cadavers (84 upper limbs) of Indian origin. When there was a PMA, its outer diameter was measured in the carpal tunnel. The PMA was found in 13 upper limbs (15.4%), and of these ten incidences (11.9%), the PMA took part in the formation of SPA, and in three instances (3.5%), the PMA did not make up part of the SPA. Out of the ten cases in which the PMA contributed to the formation of SPA, in six cases (7.1%), the PMA anastomosed with the UA; in three cases (3.5%), the PMA anastomosed with both the UA and the RA, and in one incidence (1.1%), the PMA joined the arteria radialis indicis (deep branch of the RA) to complete the SPA. The outer diameters of the median arteries varied between 0.8 and 2.6 mm with the mean value of 1.7mm. The present study concludes that the median-ulnar type of SPA was the most common type of SPA when the PMA was encountered as a source of superficial arterial arcade of the hand, followed by the radial-median-ulnar type. The vascular patterns found in this study are important to hand surgeons. The present study of PMA origin, course, and its contribution to the SPA will add to the existing knowledge of the vascular anatomy of forearm and hand.

Superficial palmar arch (SPA) is a dominant vascular structure in the palmar region that provides a major blood supply to fingers. Present case describes a rare formation and branching pattern of SPA in a formalin fixed cadaveric left hand. In this case, SPA was formed by the anastomoses between radial artery (RA) and the superficial brachioulnar artery (SBUA), which is defined as an ulnar artery with a high origin in the arm. More interestingly, unlike classic literature, SPA sends out six branches instead of four, and the principle artery of thumb arises directly from SPA instead of RA. The aforementioned variations have rarely been reported in previous literature and demonstrate important clinical significance for accidental intra-arterial injections, errors in blood pressure readings, as well as orthopedic, plastic and vascular surgeries of the upper limbs.

We raised thenar island flaps that were supplied by perforators that originated in the superficial palmar arch or the superficial palmar branch of the radial artery for the reconstruction of fingertip defects in eight patients. The flap was so well-vascularised that a large flap with increased mobility could be raised. The donor site was covered with well-vascularised thick tissue, and skin grafting of the donor site was avoided in all cases. No patient developed a complication, and all flaps survived. Functional and cosmetic results of both fingertips and donor sites were excellent. A perforator island flap from the thenar eminence can be raised easily without injuring any digital and palmar arteries. They have a good colour and texture that matches the fingertips and donor site defects on the palm.

Conventional open carpal tunnel release surgery is one of most successful procedures in hand surgery and has been demonstrated to be an effective treatment for carpal tunnel syndrome. However, a known sequelae in some individuals who undergo the procedure is “pillar” pain. In an effort to avoid this condition and help people return to work more quickly, the endoscopic technique was developed. Endoscopic carpal tunnel release offers a minimally invasive alternative to other traditional techniques with similar outcomes. By placing the incision proximal to the transverse carpal ligament there is potential for decreased scar sensitivity and pillar pain. The technique is technically demanding. The superficial palmar arch and common digital nerve to the ring and middle fingers are at risk for injury during the procedure. With adherence to anatomical landmarks and the proper visualization, the surgery may be safely performed.

The superficial palmar arch is an important anatomical structure that contributes to the arterial supply of the palmar side of the hand in the upper extremity. However, there is limited information on the embryological morphological structure of the superficial palmar arch in the literature. We studied the types of the superficial palmar arch and determined their variations by dissecting 80 upper extremities of 40 formalin-fixed human fetuses (19 males, 21 females) 18-37weeks of age. The types and variations of the superficial palmar arch were examined, and the median artery was imaged. The superficial palmar arch type was complete in 58 hands (72.5%) and incomplete in 22 hands (27.5%). The complete group consisted of type A (47.5%), type B (16.25%), type C (3.75%), type D (1.25%), and type E (3.75%). On the other hand, the incomplete group consisted of type F (15%), type G (8.75%), type H (2.5%), and type I (1.25%). A median artery that originated from the ulnar artery and passed through the carpal tunnel during its course was detected in two hands (2.5%). Knowledge of the superficial palmar arch variations will contribute to hand microsurgery particularly in vascular graft and free flap application interventions for arterial bleeding in the palmar region.

ANATOMY OF THE RADIAL BRANCHES OF THE PALMAR ARCH

Background: The third common digital nerve (TCDN) has been described as the most commonly injured digital nerve during carpal tunnel release (CTR). Anatomic variations of the origin and course of the TCDN from the median nerve may place this structure at risk. Anatomic landmarks may be useful to predict the location of the TCDN to minimize the risk for injury to this structure during CTR. Methods: Twenty cadaveric hands were used to determine the origin and course of the TCDN. The origin of the TCDN from the median nerve was identified in relation to the transverse carpal ligament (TCL), cardinal line, and superficial palmar arch. The course of the TCDN was inspected in relation to the scaphoid tubercle and ring finger. Results: Three specific anatomic variations for the origin of the TCDN were identified: type 1 originating proximal to the distal edge of the TCL (3 of 20 patients), type 2 originating distal to the TCL but proximal to the superficial palmar arch (14 of 20 patients), and type 3 originating distal to the TCL and at or distal to the superficial palmar arch (3 of 20 patients). The origin of the TCDN was measured as an average of 5.0 ± 1.2 mm distal to the cardinal line. The TCDN coursed along an oblique vector from the scaphoid tubercle to the midpoint of the palmar digital crease of the ring finger for type 2 or type 3 variations. Near the cardinal line, the oblique course of the TCDN traverses the vector of thelongitudinal incision used for CTR. Conclusion: The TCDN is one of the most frequently damaged neurological structures during CTR. Iatrogenic injury to this structure can be disabling and even devastating to patients. A detailed knowledge of the carpal tunnel and its underlying structures can prevent inadvertent injury to the TCDN. Anatomic landmarks to predict the origin and the course of the TCDN allow the surgeon to preoperatively predict the possible locations and paths of this important structure. This information can prove to be useful in avoiding injury to the TCDN by clinicians performing CTR in their practice, whether via the open or via endoscopic technique.

Background: The blood supply of the hand is complex and challenging. Awareness of the anatomical variationis necessary not only for the anatomist but also for surgeons.The ulnar artery provides a major blood supply to the hand with the assistance of the radial artery in the form of the superficial palmar arch.The objective of this study was reported a rareanatomical variation of the superficial palmar arch.Materials and Methods: The anatomical variation described was found during routine dissection performed by medical students of second semester in a 75-year-old male embalbed adult cadaver in the laboratory of Morphology of the University of Pamplona.Results and Discussion: In the right hand, the superficial palmar arch only gave rise to two common palmar digital arteries. In the left hand, the arch provided common palmar digital arteries which ran into the first, third and the fourth spaces and one proper palmar digital for the little finger. The arch does not supply the second intermetacarpal space.Conclusions: Less critical knowledge of vasculature of the hand might lead iatrogenic injury during surgery, microvascular surgery for revascularization, replantation and composite tissue transfers.Bangladesh Journal of Medical Science Vol.17(3) 2018 p.496-500

The quality of diagnostic accuracy studies is determined by 2 key factors: risk of bias and comparability. Bias can distort accuracy estimates and poor reporting impairs comparability. While diagnostic accuracy studies for fine-needle aspiration cytology (FNAC) are frequently published, the methodologic issues associated with this body of literature have never been reviewed. To assess the quality of design and reporting of diagnostic test accuracy studies in FNAC. Diagnostic accuracy studies were identified by a Medline (US National Library of Medicine) search. Sixty-four FNAC diagnostic test accuracy studies were randomly selected for structured review with the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) survey. Studies were divided between 2 time periods: 2000-2001 and 2009-2011. Diagnostic test accuracy studies of FNAC suffer from numerous deficiencies in study design, which negatively affect the reliability of accuracy estimates.

Background: Superficial Palmar Arch (SPA) is an arterial arcade usually formed by the continuation of ulnar artery and the superficial branch of radial artery. Variations can occur in the vessels contributing to the formation of SPA. Knowledge of such variations will be very much helpful to microvascular surgeons, plastic surgeons and orthopaedicians to bring a better outcome in their surgical procedures. Also, it will be useful to the cardiovascular surgeons to carryout radial artery harvesting procedures for the purpose of Coronary Artery Bypass Grafting. The main objective is to study the different patterns of formation of the superficial palmar arch with an emphasis on their clinical importance.

Elbow traumas represent a relatively common condition in clinical practice. However, there is a lack of evidence regarding the most accurate tests for screening these potentially serious conditions and excluding elbow fractures. The purpose of this investigation was to analyze the literature concerning the diagnostic accuracy of clinical tests for the detection or exclusion of suspected elbow fractures. A systematic review was performed using the Preferred Reporting Items for a Systematic Review and Meta-analysis of Diagnostic Test Accuracy Studies (PRISMA-DTA) guidelines. Literature databases including PubMed, Cumulative Index to Nursing and Allied Health Literature, Diagnostic Test Accuracy, Cochrane Library the Web of Science, and ScienceDirect were searched for diagnostic accuracy studies of subjects with suspected traumatic elbow fracture investigating clinical tests compared to imaging reference tests. The risk of bias in each study was assessed independently by two reviewers using the Quality Assessment of Diagnostic Accuracy Studies 2 checklist. Twelve studies (4,485 patients) were included. Three different types of index tests were extracted. In adults, these tests were very sensitive, with values up to 98.6% (95% confidence interval [CI], 95.0%–99.8%). The specificity was very variable, ranging from 24.0% (95% CI, 19.0%–30.0%) to 69.4% (95% CI, 57.3%–79.5%). The applicability of these tests was very high, while overall studies showed a medium risk of bias. Elbow full range of motion test, elbow extension test, and elbow extension and point tenderness test appear to be useful in the presence of a negative test to exclude fracture in a majority of cases. The specificity of all tests, however, does not allow us to draw useful conclusions because there was a great variability of results obtained.Level of evidenceIV.

Background: Nerve conduction studies (NCS), ultrasonography (US), Carpal Tunnel Syndrome 6 (CTS-6), Wainner, Lo, and Kamath are clinical diagnostic tools that can be used to diagnose carpal tunnel syndrome (CTS). Latent class analysis (LCA) is a proven statistical technique that can be used to evaluate diagnostic tests in a lack of a reference standard. Given that there is no accepted reference standard, we elected to perform an LCA to evaluate the 6 clinical diagnostic tests. Methods: One hundred eighty-seven wrists were prospectively evaluated by a board-certified hand surgeon using US, the CTS-6, Wainner, Lo, and Kamath. The NCS were performed by an electrophysiologist according to the standards of the American Association of Neuromuscular & Electrodiagnostic Medicine. The LCA was performed to evaluate individual performance and pairwise combinations of the tests. Results: The NCS demonstrated the highest estimated sensitivity of 97%, and the Wainner had the highest estimated specificity of 97%. Alternatively, the Lo had the lowest estimated sensitivity (36%), and NCS had the lowest estimated specificity (40%). When evaluating pairwise combinations, positive US and NCS demonstrated the highest overall sensitivity at 86%, and negative US and NCS had a specificity of 83%. Conclusions: There is no perfect clinical diagnostic test, with the 6 clinical diagnostic tests having differing sensitivities and specificities. Pairwise combinations of the test can be used to complement one another.