These eight bones are stacked neatly in two rows at the base of the hand (directly under the thicker parts of the palm). Anterior (palmar) view. Despite best efforts, some patients are unable to tolerate the positions required for these special views because of pain [5]. This may take the form of ulnar nerve contusion, or ulnar nerve compression from ulnar artery aneurysm ( Fig. Copyright © 2021 Lineage Medical, Inc. All rights reserved. The hook of hamate (Latin: hamulus) is found at the proximal, ulnar side of the hamate bone. These tests help confirm the diagnosis and rule out other causes of your pain. Hook of hamate fractures are hard to capture through imaging, even with this special view. Hamate fracture causes. Hook of hamate fx (most common) • I - avulsion • II - middle of hook • III - base of hook : Type II Body of hamate fx • IIA - coronal • IIB - transverse : Presentation: Symptoms . Hook of the Hamate (n.) 1. J Hand Surg Am 1989; 14:486. Each arm was then mounted in a jig designed to hold and stabilize the arm and hand in supination. Its medial surface to the flexor digiti minimi brevis and opponens digiti minimi; its lateral side is grooved for the passage of the flexor tendons into the palm of the hand. It bears an uncinate (unciform) hamulus (hook of hamate) which projects in a volar fashion from the distal part of its palmar surface. Clinical findings of hook of hamate tenderness had better sensitivity than carpal tunnel-view radiographs. Fractures of the hook of the hamate have rarely been reported. The hamate is found within the distal row of carpal bones, and abuts the metacarpals of the little finger and ring finger. Hook of the hamate fractures at the midpoint or distal tip are more readily detected in special views, whereas fractures at the base of the hook are more commonly obscured . Hook of hamate fractures are further subdivided according to their location in the hook: Type 1 fractures are located at the distal hook, type 2 at the middle, and type 3 are located at the base of the hook. Signs and Symptoms of Fracture of Hook of Hamate [2] Pain in the wrist. Point tenderness occurs in the palm over the hook of the hamate. Hamate fracture - Oblique view. golf, baseball, racquet sports) from a direct blow while swinging. Introduction. The hamate bone is sometimes described as triangular in shape and others describe it as more square-like. The hamate bone is one of eight carpal bones that forms part of the wrist joint. Ulnar tunnel decompression with hook of hamate excision provides good … Digit. Hook of Hamate Fracture: A fracture of one of the eight carpal bones located on the ulnar side of the distal carpal row. The lorica hamata (in Latin with normal elision: [loːr̺iːk‿(h)aːmaːt̪a]) is a type of mail armour used by soldiers for over 600 years (3rd century BC to 4th century AD) from the Roman Republic to the Roman Empire. Hamate, along with the other carpal bones, form the human wrist that works as a bridge between the lower arm and hand. There will be acute tenderness on palpation in the anatomical snuff box. The hook of the hamate pull test (15) (HPPT) is a clinical test for diagnosing a hook of hamate fracture, which was negative in this case. The characteristic hook-shaped process on the hamate bone’s palmar (volar) surface is known as the hook (hamulus) of the hamate. The mechanism of hook of hamate fractures in baseball players is predictable, most often developing secondary to repetitive swinging. Sometimes it is also called unciform bone. Point tenderness occurs in the palm over the hook of the hamate. We propose three radiographic signs of fracture that are readily seen on routine PA projections: "absence" of the hook of the hamate; "sclerosis" of the hook; and lack of cortical density, i.e., a barely visible outline, of the hamulus. Nonunion occurred in 24% of patients with non-operative treatment and did not occur in the operative group. An MRI or CT scan may be ordered as well as they can show with more sensitivity if a Hook of the Hamate fracture has occurred. The hamate has a wedge-shaped body. METHODS: One thousand pairs of hamates (2,000 hamates) from the Hamann-Todd Collection at the Cleveland Natural History Museum were analyzed. A rare case of traumatic, isolated dislocation of the hamate with hook fracture in the setting of concomitant acute hand compartment syndrome is presented. This condition is known as fracture of hook of hamate. Hook of hamate fractures account for 2-4% of all carpal fractures in athletes and generally occur in baseball, golf, or racquet sport secondary to acute trauma [1]. B, Oblique view. 5-37 ) or swelling within the ulnar tunnel, possibly associated with ulnar artery thrombosis ( Fig. Objective.—Hamate hook fractures are rare injuries, comprising 2% to 4% of all carpal fractures. Isolated transverse fracture of the body of the hamate … 5-38 ). Lorica hamata comes from the Latin hamatus (hooked) from hamus which means "hook", as the rings hook into one another. The carpal bones function as a unit to provide a bony superstructure for the hand.[1]:708. [1]:708–709, Adjacent to the hamate on the ulnar side, and slightly above it, is the pisiform bone. The ossification of the hamate starts between 1 and 12 months. The hamate is a wedge-shaped bone located on the outside of the wrist on the small-finger side. Hook of hamate fractures (also sometimes termed type 1 hamate fractures) are rare. Hook of hamate fractures are rare. Tested Concept, Contrast enhanced magnetic resonance angiogram, (OBQ04.21) The hook of hamate injuries are mainly due to repeated impact, usually, a sporting activity (racket, club, bat) exerting a direct force against the hamate 13).The hook of hamate is always at risk because of its peculiar anatomy, … Thumb on bottom. Multiple structures insert on the hook of hamate, including the transverse carpal ligament, hypothenar muscles, and pisohamate ligament. The hook of the hamate also helps to form two important structures in the wrist. Fractures of the hamate are unusual due to their location. It has four surfaces: 1. superior surface: apex of the wedge is narrow, convex, and smooth 2. inferior surface: concave facets separated by a ridge 3. volar surface: hook-like process (hamulus) on the lower and ulnar side 4. medial surface: oblong facet The hamate articulates with five b… This condition causes pain and tenderness just outside a joint. It is the most ulnar based bone within the distal carpal row. The first is the inner (medial) border of the carpal tunnel, through which the median nerve runs. There are two common injuries associated with Golfer’s Wrist, which involve fractures or tissue swelling. J Hand Surg Am 1992; 17:507. before or at their growth spurt). He is tender over the hypothenar eminence and has paresthesias in the ring and small fingers. The hook is a curved, hook-like process that projects 1–2 mm distally and radially. They occur from the hamate fracturing after blunt trauma, falls, and in sports player (e.g. A 20-year-old, right-hand dominant woman presented with left hand numbness and weakness, 10 days after undergoing a nondisplaced hook of hamate excision performed at an outside institution. Flex Digit Profundus Ext. Tested Concept, (SBQ07SM.40) Both treatment groups achieved good clinical results, with a grip strength of 80% compared … The calcification of the unciform bone is seen on X-rays during puberty and is sometimes used in orthodontics to determine if an adolescent patient is suitable for orthognathic intervention (i.e. Watson HK, Rogers WD. The hamate bone is one of eight small bones of the wrist. The hamate is bordered proximally by the pisiform and the lunate in the proximal carpal row, radially by the capitate, and distally by the bases of the fourth and fifth metacarpals.. The Guyon canal carries the ulnar artery and nerve, for this reason hook fractures should suggest a high probability of ulnar artery and nerve damage. Hook of hamate fracture, the most common swing-related wrist fracture, is commonly seen in high-level athletes. The bone is also found in many other mammals, and is homologous with the "fourth distal carpal" of reptiles and amphibians. Several professional baseball players have had the bone removed during the course of their careers. I went to a couple of doctors for opinions. It is situated in the distal row of carpal bones on the medial side of the wrist. This article incorporates text in the public domain from page 227 of the 20th edition of Gray's Anatomy (1918). Scheufler O, Radmer S, Andresen R. Dorsal percutaneous cannulated mini-screw fixation for fractures of the hamate hook. The hook is located by projecting a line from the pisiform to the center of the head of the index metacarpal. Right hand posterior view (dorsal view). Flex. Which radiographic view is most likely to reveal the pathology? Heck, I’ll throw in both nuts. It has a hook-like projection on its surface (thus its name) that can be fractured in certain activities. Undisplaced hook of hamate fracture that was completely occult on x-ray. His CT scan is shown in Figure A. What is the recommended treatment? Additional special projections for the hook of the hamate include the semi-supinated oblique view, carpal tunnel view, and lateral view with thumb abduction and radial deviation of the hand [9]. The most frequent causes of fractures of the hamate hook are sports that require a strong grip such as golf, baseball, and tennis. Transverse section across the wrist and digits. Upon evaluation, the patient presented with a positive hook-pull test with pain to touch on the hamate. The hamate bone or unciform bone (from Latin uncus, "hook") is a bone in the human wrist readily distinguishable by its wedge shape and a hook-like process ("hamulus") projecting from its palmar surface. A 24-year-old professional baseball outfielder reports persistent pain in the hypothenar region when batting for the past year. The hook of the hamate pull test (15) (HPPT) is a clinical test for diagnosing a hook of hamate fracture, which was negative in this case. Symptoms are pain aggravated by gripping, tenderness over the hamate and symptoms of irritation of the ulnar nerve. Bones of the left hand. Hover on/off image to show/hide findings. Hamate bone of the left hand. Collectively, the bones are called the carpal bonesthe word comes from the Latin word meaning \"wrist.\" Most people have heard of carpal tunnel syndrome, a condition where a nerve is pinched as it passes through a tight canal partly formed by the carpal b… Hamate fracture - Oblique view. Deep dissection. Right wrist joint. The Hamate bone is one of the small eight carpal bones located in your wrist. Hook of the hamate fractures account for only 2% to 4% of all carpal fractures.1 Athletes participating in stick-handling sports account for the vast majority of these injuries and are most at risk of long-term complications secondary to missed or delayed diagnosis.1,2,19,20 The mechanism of injury is either (1) direct Figure 39-4 Postoperative radiographs: Percutaneous scaphoid stabilization. Right hand anterior view (palmar view). Stress fractures have also been reported. Which of the following should initially be obtained in this patient to aide in the diagnosis? They have usually resulted from blunt trauma or a sharp strike against the hamate hook while swinging a golf club, baseball bat, or tennis racquet. Symptoms of a fracture of the hook of hamate usually follow a traumatic incident and include: Wrist pain on the little finger (Ulna) side of the wrist. The hook of hamate forms the ulnar border of the carpal canal. The most frequent causes of fractures of the hamate hook are sports that require a strong grip such as golf, baseball, and tennis. Hamate shown in yellow. Expansions 2-5 UlnarC8.TI Flex Digit at MCP. Hamate shown in yellow. Dorsal surface. It is the most ulnar based bone within the distal carpal row. It is located 2 cm distal along the imaginary line from the pisiform to the second metacarpal head. Patients present with acute onset of pain localised over the ulnar aspect of the wrist and reduction in grip strength. [2], It is also a common injury in baseball players. A carpal bone located between the CAPITATE BONE and the TRIQUETRUM BONE. A, Scaphoid view. Hook of hamate fractures account for 2-4% of all carpal fractures in athletes and generally occur in baseball, golf, or racquet sport secondary to acute trauma [1]. It is located 2 cm distal along the imaginary line from the pisiform to the second metacarpal head. You will have reduced grip strength. This is characterized by numbness and weakness of the pinkie finger with partial involvement of the ring finger as well, the "ulnar 1½ fingers". Tested Concept, Activity restriction and continued monitoring, Casting for 6 weeks, followed by physical therapy, Corticosteroid injection and immediate return to play, (OBQ08.23) Stress fractures have also been reported. The hamate is an irregularly shaped carpal bone found within the hand. He is tender to palpation over the hypothenar mass, and his pain is aggrevated by grasping. The hook is located by projecting a line from the pisiform to the center of the head of the index metacarpal. Nonoperative treatment of acute hamate hook fractures. The hamate hook is supplied by two blood vessels, one entering from the ulnar tip, while the other enters through the radial base [12]. An x-ray is needed in order to accurately diagnose a fracture of the Hook of the hamate. Fracture of the hook of hamate is often caused by swinging a baseball bat, tennis racket or golf club, especially when it suddenly hits a stationary object. CT scans and magnetic resonance imaging (MRI) tests may be ordered to look at the bones and soft tissues in your wrist. The hook of hamate can be palpated on the medial side of the wrist inferior and laterally to the pisiform.[1] The ulnar finger flexor tendons run around the base of the hook in a pulley fashion when the wrist is in ulnar deviation. Hook of Hamate fractures are not overly common, as it takes a very specific load to fracture it, but I’d bet my left testicle that this is the cause of your pain. Case Report: A 28-year-old man presented with a left hand crush injury. The hamate has a prominent process that projects anteriorly. The fracture is usually a hairline fracture, commonly missed on normal X-rays. PA; lateral; ER oblique . The hamate bone is the bone most commonly fractured when a golfer hits the ground hard with a golf club on the downswing or a hockey player hits the ice with a slap shot. Hamate bone shown in red. Surgical excision has a high success rate, however diagnostic delay contributes to a high complication rate. hook of the hamate is common [4–6]. The hamate bone is a wedge-shaped carpal bone on the pinky finger side, of the wrist. Positive results on the HHPT correctly predicted a hook of hamate fracture that was confirmed in each case by a CT scan and subsequent surgery. The case shows a carpal tunnel view for the diagnosis of the hook of hamate fracture. The hamate has a wedge-like shape with a distinct bony process called hook of hamate that extends from the palmar surface. neurolysis of deep motor branch of ulnar nerve is recommended. It has multiple articulation surfaces. The hook of hamate injuries are mainly due to repeated impact, usually, a sporting activity (racket, club, bat) exerting a direct force against the hamate 13). A professional baseball player develops acute hand pain after fouling off a pitch. Exercise therapy following splinting significantly decreased pain and allowed the patient to regain pre-injury wrist function. Bones of the left hand. A 24-year-old racquetball player presents after accidentally striking his racket against the wall during a match three months ago. In each case, the initial injury was considered trivial; medical attention was not sought until rupture of the little profundus/superficialis tendon occurred. We hypothesize that there are variations in the hook of the hamate in the general population. Isolated transverse fracture of the body of the hamate … Tendinitis: Inflammation or irritation of a tendon. Thumb on top. The typical natural history patterns of missed hook of the hamate fractures include uncomplicated fracture healing, asymptomatic nonunion, and symptomatic nonunion or partial union [ 5 ]. The hook of hamate (Latin: hamulus) is found at the proximal, ulnar side of the hamate bone.The hook is a curved, hook-like process that projects 1–2 mm distally and radially. A hook of hamate fracture is suggested by a medical history of acute onset of pain when swinging a bat, racquet, or club; by lingering pain in the wrist or palm, or both; and inability to return to sports. focal tenderness over hamate ; Imaging: Radiographs . Nonunion of the hook of the hamate: an argument for bone grafting the nonunion. How does the patient present with a scaphoid fracture? Four cases of undiagnosed hook of the hamate fracture are presented. The hook of hamate is involved in the formation of some important structures in the wrist. The curved portion of the hamate bone also makes up the outside (lateral) border of Guyon’s canal, a … Which of the following treatment methods has been definitively shown in the literature to have a favorable outcome, and a high chance to return to pre-injury activities in patients with this injury? The hamate specifically is located on the ulnar side of the wrist, opposite the thumb. The Hook of Hamate fractures are almost exclusively a golfing injury, and injury to the distal end of the ulna nerve are not uncommon. in 2010, along with therapeutic outcomes of hook of hamate fractures. The ulnar nerve hooks around the hook of hamate as it crosses towards the medial side of hand. The hook of the hamate is also subject to fracture from injury. What is a Hook of Hamate Fracture? (OBQ11.130) One said 12 days in a splint and full recovery in 5-6 weeks post surgery. A positive vibration test to the hamate for ulnar nerve was also recorded. The hamate is a triangular-shaped bone that forms part of the distal carpal row, articulating with the capitate (radially), triquetrum (proximally) and fifth and fourth metacarpals (distally). This injury may occur at all levels of competition. A certain type of x-ray called the carpal tunnel view, is able to visualize the hamate and make a more accurate diagnosis. [3] The hamate does not fully ossify until about the 15th year of life.[2]. Dr. Knight removes the hook of hamate after a college baseball player sustained a fracture to the hook. Hamate is a bone, which is located on the outside or the little finger side of the wrist and has a hook shaped structure at the end. The patient presents with thumb sided wrist pain following a fall onto an outstretched hand. The hook of hamate is palpable in the hypothenar area. Left hand. recommended views . Dr. Knight removes the hook of hamate after a college baseball player sustained a fracture to the hook. I am not a golfer, but I too had hamate hook surgery. Although pain and function have improved with conservative treatment 6 months following the injury, he still reports difficulty with his golf game. Closed rupture of the flexor tendons to the small finger, excision of large hook of hamate fractures, Lunate Dislocation (Perilunate dissociation), Gymnast's Wrist (Distal Radial Physeal Stress Syndrome), Scaphoid Nonunion Advanced Collapse (SNAC), Carpal Instability Nondissociative (CIND), Constrictive Ring Syndrome (Streeter's Dysplasia), Thromboangiitis Obliterans (Buerger's disease), hook of hamate fractures are rare, often missed, injuries generally as a result of a direct blow to the hamate bone most commonly seen in athletes, treatment is generally patient-specific and depends on chronicity of injury, carpal bone that is distal and radial to the pisiform, roof - superficial palmar carpal ligament, floor - deep flexor retinaculum, hypothenar muscles, ulnar border - pisiform and pisohamate ligament, one of the palpable attachments of the flexor retinaculum, vessels enter the hamate base via a radial and ulnar foramina to supply the hook of the hamate, ulnar vessel is absent in 29% of patients, absent ulnar vessel considered the reason for high non-union rate of hook of hamate fractures, positive tinel's over Guyon's canal may be present, hand held in ulnar deviation as patient flexes DIP joints of the ulnar 2 digits against resistance, the flexor tendons act as a deforming force on the fracture site, positive test elicits pain, establish diagnosis if radiographs are negative, most accurate method of diagnosis in cases of high-clinical suspicion, majority of nondisplaced acute hook of hamate fractures, majority of patients are pain-free and have full ROM despite non-union, modified volar wrist incision in lined with the ulnar border of ring finger, release of the guyon canal generally also performed, hook should be removed subperiosteally to avoid damage to motor branch of ulnar nerve, considered natural course of fracture given fracture site motion and poor blood supply. It projects outwards from the lower part of the palm, on the side of the pinkie finger, and has no bony articulations. Always obtain “tunnel view” or carpal tunnel view if there is a concern for a hook of hamate fracture. I fell mountain biking while travelling and thought it was a sprain, but when after over a month it didn't get better I got it checked. It has a hook-like projection on its surface (thus its name) that can be fractured in certain activities. Fractures of the carpal hamate are rare injuries. Fracture of hook of the hamate can also be a result of forceful muscular contractions though there may be no direct trauma. Guyon’s canal is located along the lower edge of the palm. These are estimated to occur in 2 % - 4 % of all carpal bone fractures [1, 2].Milch (1934) reported a case of the fracture of body of the hamate along with a fracture of ulnar styloid [].He suggested that these fractures can be divided into two types: those involving the body, and others involving the hook of the hamate. Left hand anterior view (palmar view). impact via the handle of a club, racquet, or bat or (2) shearing forces arising from the hyp… Multiple structures insert on the hook of hamate, including the transverse carpal ligament, hypothenar muscles, and pisohamate ligament. A radiograph and CT scan of his wrist are shown in Figures A and B. This arti-cle reviews the diagnostic imaging, clinical presentation, and treatment of hook of the ha-mate fracture, developmental anomalies, infec - Always obtain “tunnel view” or carpal tunnel view if there is a concern for a hook of hamate fracture. Hook of hamate fractures were diagnosed with advanced imaging at a median of 27 days. hook of hamate fractures are rare, often missed, injuries generally as a result of a direct blow to the hamate bone most commonly seen in athletes treatment is generally patient-specific and depends on chronicity of injury The hook of hamate forms the ulnar border of the carpal canal. The hook-like process is called hamulus. Functions: What Does the Hamate Bone Do. A custom dorsal blocking splint was recommended to treat the hamate injury. The hamate bone is one of eight carpal bones, it is a triangular bone, composed of a body and a hook (hamulus), located on the ulnar side of the distal carpal row.. ulnar-sided wrist pain and swelling ; Physical exam . Eleven patients (two with fresh fractures and nine with nonunion) were studied. The hook of hamate is palpable in the hypothenar area. The word hamate is derived from the Latin word hamulus which means “a little hook”. It bears an uncinate (unciform) hamulus (hook of hamate) which projects in a volar fashion from the distal part of its palmar surface. The hook forms the ulnar border of the carpal tunnel, and the radial border for Guyon's canal. Adjacent on the radial side is the capitate, and proximal is the lunate bone.[1]:708–709. The hook of hamate is particularly prone to fracture-related complications such as non-union due to its tenuous blood supply. Imaging plays a central role in identifying pathologic conditions affecting the hook of the hamate and in guiding clinical decision making. The hook of hamate is always at risk because of its peculiar anatomy, protruding from its body into the ulnar aspect of the palm. Position of hamate bone (shown in red). Hook of Hamate Fractures The hamate bone is one of the eight small carpal bones in the wrist that connect the forearm to the hand. Hook of Hamate Fracture: A fracture of one of the eight carpal bones located on the ulnar side of the distal carpal row. We studied the clinical and radiological findings in 12 patients who had fracture of the hook of the hamate. The hook (also known as the hamulus) is a curved bony process that extends from the palmar surface of the body ().The hook of the hamate contributes to the medial border of the carpal tunnel and the … Tap on/off image to show/hide findings. Hamate shown in yellow. The hook shaped part of the hamate bone which protrudes outwards may break easily due to injury. The hamate is found within the distal row of carpal bones, and abuts the metacarpals of the little finger and ring finger. Fractures of the hamate are unusual due to their location. The hamate is an irregularly shaped carpal bone found within the hand. Patients present with acute onset of pain localised over the ulnar aspect of the wrist and reduction in grip strength. They are a form of hamate fractures and occur from the hamate fracturing after blunt trauma, falls, and in sports player (e.g. Animation. This case shows the value of MRI in patients with persistent symptoms post FOOSH. Non-operative treatment . Tested Concept, Type in at least one full word to see suggestions list, Everything You Need to Know About the Hook of Hamate, Hamate Hook Fracture in 21M Collegiate Baseball Player, Hamate Body and Base of Ring Metacarpal Fracture Dislocation. It may result in Guyon's canal syndrome. Osteotomy of the hook of the hamate was performed through a skin incision proximal to the hook of the hamate and the transverse carpal ligament. Direct blow to the wrist. Treatment for a Hook of Hamate Fracture. This is the first described case of isolated hamate dislocation presenting with symptoms and examination consistent with acute compartment syndrome of the hand. inspection . All were treated with excision of the hook and tendon repair, which usua … Hook of the hamate fractures. Fractures of the hook of the hamate have rarely been reported. in these standard views poorly show the hook of the hamate. It is a wedge-shaped bone with a hook-like process that can be found in the medial side of the wrist. The hamate is situated in the distal carpal row at the ulnar aspect of the wrist. The hook of the hamate forms part of Guyon’s canal, also known as the ulnar canal. often seen in athletes in sports requiring gripping, small finger/ring finger flexor tendonitis or tendon rupture, deep branch of ulnar nerve lies under the hook, average of 4 weeks from injury to diagnosis, best radiograph to see hook of hamate fracture, can be missed if nondisplaced and if CT cuts greater than 1 mm, symptomatic chronic hook of hamate fractures with non-union, hook of hamate fractures with ulnar neuritis, fastest recovery and return to play noted for athletes who wish for prompt return to play, some studies show decreased small finger FDP tendon strength by 10-15% with excision, excision leads to 5 mm of ulnar displacement of small finger FDP tendon, acute and significantly displaced fractures in patient's unable to tolerate reduction in grip strength, small case series have shown nearly 100% union rate, theoretically improved grip strength compared to excision, small-fragment headless compression or countersunk screws, screws need to be countersunk to prevent irritation of the deep motor branch of the ulnar nerve. Type 3 fractures account for the majority of hook of hamate fractures (6). Cross section of wrist (thumb on left). Because the hook of the hamate bone is directly deep to the ulnar nerve and artery, direct impact on the ulnar aspect of the hand can cause injury to the ulnar nerve and artery. The fracture is rarely diagnosed on routine wrist radiographs, thus generally requiring CT or MR for diagnosis. "A Study of Ossification of Capitate, Hamate, Triquetral & Lunate in Forensic Age Estimation", https://en.wikipedia.org/w/index.php?title=Hamate_bone&oldid=1009405901, Wikipedia articles incorporating text from the 20th edition of Gray's Anatomy (1918), Creative Commons Attribution-ShareAlike License, This page was last edited on 28 February 2021, at 11:59.