Anatomical snuffbox

The anatomical snuffbox, also called the fovea radialis, is a triangular deepening on the radial and dorsal side of the hand at the level of the carpal bones.鼻烟窝（anatomical snuffbox）又称桡窝，是腕骨水平手背桡侧的三角形凹陷。

Its name comes from the old habit of placing powdered tobacco in the hollow before sniffing it, and the French term tabatière is still used as a synonym.其名称源于旧时把鼻烟放在这一凹陷处再嗅吸的习惯，法语词（tabatière）至今仍作同义词使用。

Structure

• The floor of the hollow is formed by the scaphoid and the trapezium, and the proximal border by the styloid process of the radius.窝底由手舟骨（scaphoid）与大多角骨（trapezium）构成，近侧界为桡骨茎突。
• The lateral border is made up of the paired tendons of the extensor pollicis brevis and the abductor pollicis longus.外侧界由拇短伸肌（extensor pollicis brevis）与拇长展肌（abductor pollicis longus）的一对肌腱构成。
• The medial border is the tendon of the extensor pollicis longus, and the distal border is the apex where the two sides meet.内侧界为拇长伸肌（extensor pollicis longus）的肌腱，远侧界为两侧相交的顶点。
• The hollow is deepest when the thumb is extended and abducted, which is the position used to demonstrate it at the bedside.拇指伸并外展时凹陷最深，这是临床上演示该窝的体位。
• The radial pulse is taken at the wrist just proximal to the hollow, so the same landmark serves the traditional transradial approach.桡动脉搏动在窝的近侧腕部扪及，因此同一标志也服务于传统的经桡动脉入路。
• The radial artery crosses the snuffbox on its way from the wrist pulse area to the first intermetacarpal space.桡动脉跨过鼻烟窝，自腕部搏动区走向第一掌骨间隙。
• Deep to the tendons the artery lies less than 2 mm from the superficial branch of the radial nerve near the styloid process in 48% of limbs.在肌腱深面，48% 的肢体中该动脉在茎突附近与桡神经浅支相距不足 2 mm。^[1]
• In a further 24% the artery is openly related to the lateral cutaneous nerve of the forearm instead.另有 24% 的肢体中，该动脉改为与前臂外侧皮神经直接相邻。
• The cephalic vein begins within the snuffbox and ascends along the lateral side of the forearm.头静脉（cephalic vein）起于鼻烟窝内，沿前臂外侧上行。
• On the surface the hollow overlies the first dorsal compartment of the wrist, whose tendons can be felt moving when the thumb is extended.在体表，该窝对应腕的第一背侧间室，拇指伸展时可扪及该室肌腱滑动。

Function

• The snuffbox serves as a surface landmark for finding the radial artery and the scaphoid through the skin.鼻烟窝充当体表标志，用于经皮定位桡动脉与手舟骨。
• It gives access to the scaphoid for palpation when the wrist is placed in slight ulnar deviation.腕轻度尺偏时，可经该窝触诊手舟骨。
• The deepening of the hollow on thumb extension offers a quick visual check of the extensor tendons.拇指伸展时凹陷加深，为伸肌腱提供快速的目检方式。
• The tendons that border the hollow convert the pull of the forearm muscles into abduction and extension of the thumb.围成凹陷的肌腱把前臂肌的牵拉转化为拇指的外展与伸展。

Vasculature and innervation

• The radial artery passes through the snuffbox and divides into branches that help form the superficial and deep palmar arches.桡动脉穿过鼻烟窝后分支参与构成掌浅弓与掌深弓。
• The dorsal carpal branch of the radial artery also arises in this region and supplies the back of the wrist.桡动脉的腕背支亦在此区域发出，供应腕背。
• Blood reaches the scaphoid mostly through branches that enter the bone distal to its waist, and about 80% of the bone's supply follows this retrograde path.手舟骨的血供多经腰部远侧进入的支流，约 80% 的骨血供走这条逆行路径。^[2]
• The superficial branch of the radial nerve crosses the extensor pollicis longus tendon and supplies the skin of the radial two fingers and the dorsum of the hand.桡神经浅支跨过拇长伸肌腱，供应桡侧两个手指与手背的皮肤。
• Just distal to the hollow the radial artery gives off the first dorsal metacarpal artery, which supplies the dorsum of the index finger.在该凹陷远侧，桡动脉发出第一掌背动脉，供应食指背侧。
• The cephalic vein, which starts in the hollow, drains the lateral side of the hand and forearm into the axillary vein.起于该凹陷的头静脉引流手与前臂外侧，最终汇入腋静脉。

Development

• The snuffbox is not a discrete embryonic structure but a surface depression that appears as the forearm muscles and their tendons differentiate.鼻烟窝并非独立的胚胎结构，而是随前臂肌肉与肌腱分化而出现的表面凹陷。
• The scaphoid and the trapezium ossify in cartilage, and the scaphoid is the last carpal bone to finish ossifying, in the teenage years.手舟骨与大多角骨经软骨内骨化，其中手舟骨是最后完成骨化的腕骨，在青春期完成。
• The radial artery reaches the dorsum of the hand as the dorsal interosseous pattern of the limb bud is established.桡动脉在肢体芽的背侧骨间模式建立时到达手背。
• The tendons of the first dorsal compartment migrate to their adult position as the thumb gains opposability.第一背侧间室的肌腱随拇指获得对捏能力而迁移至成人位置。
• The superficial branch of the radial nerve emerges from beneath the brachioradialis about 8 cm proximal to the styloid process before it reaches the hollow.桡神经浅支在抵达该窝前，约于茎突近侧 8 cm 处自肱桡肌深面穿出。

Clinical significance

• Tenderness in the snuffbox after a fall on an outstretched hand is the classic sign of a scaphoid fracture.跌倒时手掌撑地后出现鼻烟窝压痛，是手舟骨骨折的典型体征。
• The sign is highly sensitive but not specific, so imaging is needed to confirm that a fracture is really present.该体征高度敏感但缺乏特异性，需影像检查确认是否真有骨折。
• Because most of the scaphoid blood supply enters distally, a fracture through the waist can cut off the proximal pole and lead to avascular necrosis.由于手舟骨血供多自远侧进入，经腰部的骨折可切断近侧极的血供并导致缺血性坏死。
• The snuffbox is an accepted route for percutaneous fixation of scaphoid fractures and for ultrasound-guided synovial biopsy of the wrist.鼻烟窝是手舟骨骨折经皮固定与腕关节超声引导滑膜活检的公认入路。
• In distal transradial catheterisation the radial artery is punctured inside the snuffbox, where the nerve runs within 2 mm of the vessel.在经远侧桡动脉导管术中，穿刺点选在鼻烟窝内，此处神经在血管 2 mm 以内走行。
• An ultrasound study of 213 patients measured the median horizontal and vertical distances from the distal radial artery to the nerve at 5.10 mm and 2.40 mm.一项 213 例患者的超声研究测得，远侧桡动脉与神经的水平与垂直距离中位数分别为 5.10 mm 与 2.40 mm。^[3]
• The hollow is also a common site for building an arteriovenous fistula for haemodialysis by joining the cephalic vein to the radial artery.该凹陷也是建立头静脉与桡动脉吻合的血透动静脉内瘘的常用部位。
• Scaphoid fractures rank among the most frequent causes of medico-legal dispute in hand trauma because the first radiographs often look normal.手舟骨骨折是手部外伤中最常引发法医学争议的情形之一，因为首次拍片往往看不出异常。
• Since the artery is punctured inside the hollow, occlusion of the radial artery with hand ischaemia is the main vascular worry after distal access.由于动脉在窝内被穿刺，桡动脉闭塞伴手部缺血是远侧入路术后主要的血管风险。

Comparative anatomy

• A radial depression bounded by the thumb extensor tendons is found in all primates that possess an opposable thumb.在所有具有对捏拇指的灵长类中，都能见到由拇指伸肌腱围成的桡侧凹陷。
• In quadruped mammals the equivalent region is less hollowed because the hand is not used for grasping.四足哺乳动物的相应区域凹陷较浅，因为其手不用于抓握。
• The superficial course of the radial artery in this region counts as a human specialisation tied to a mobile wrist.桡动脉在此区域的表浅走行，被视为与灵活腕关节相关的人类特化。
• No eponymous structure corresponds to the snuffbox in the standard veterinary anatomical nomina.在标准兽医解剖名词中，没有与鼻烟窝相对应的专属结构。

History

• The name snuffbox entered anatomical English in the eighteenth century together with the fashion for taking snuff.「鼻烟窝」之名随 18 世纪吸鼻烟的时尚进入解剖学英语。
• The French term tabatière, meaning the same kind of snuff container, remains in use as a synonym for the hollow.法语词（tabatière）意为同一种鼻烟容器，至今仍用作该凹陷的同义词。
• The Terminologia Anatomica lists the structure as fovea radialis, a purely descriptive name.《解剖学名词》（TA）将该结构列为（fovea radialis），纯为描述性名称。
• Gray's Anatomy illustrated the region from the mid-nineteenth century and named the tendons that border it.Gray's Anatomy 自 19 世纪中叶起绘出该区域，并标注了围成它的肌腱。
• Its role in diagnosing scaphoid fracture was established in the twentieth century and is still taught as a bedside test.其在诊断手舟骨骨折中的作用于 20 世纪确立，至今仍作为床旁检查教授。
• Snuff itself fell from fashion during the nineteenth century, yet the anatomical name outlived the habit that produced it and is still used in clinics.鼻烟在 19 世纪逐渐失宠，但这个解剖名称比产生它的习惯活得更久，至今仍在临床使用。

Research and controversies

• Whether tenderness in the hollow alone justifies immobilisation is debated, since some scaphoid fractures show no such tenderness early on and the examination has to be repeated after a week or two.单凭该窝压痛是否足以固定仍有争议，因为部分手舟骨骨折早期并无此种压痛，检查须在一两周后重复。
• The sensitivity of the sign varies widely between series, depending on how soon after injury the patient is examined.不同研究系列中该体征的敏感度差异很大，取决于伤后多久接受检查。
• Distal transradial access through the snuffbox is promoted by some cardiologists as gentler on the artery and doubted by others for the risk to the nerve.部分心脏科医生推崇经鼻烟窝的远侧桡动脉入路对动脉更温和，另一些人则因神经风险而持保留态度。
• Imaging protocols now set ultrasound against computed tomography for detecting fractures that plain films miss.在发现平片漏诊的骨折上，影像方案正将超声与 CT 作对比评估。