Symptoms of gamekeeper's thumb are instability of the MCP joint of the thumb, accompanied by pain and weakness of the pinch grasp. The severity of the symptoms are related to the extent of the initial tear of the UCL (in the case of Skier's thumb), or how long the injury has been allowed to progress (in the case of gamekeeper's thumb).

Characteristic signs include pain, swelling, and ecchymosis around the thenar eminence, and especially over the MCP joint of the thumb. Physical examination demonstrates instability of the MCP joint of the thumb.

The patient will often manifest a weakened ability to grasp objects or perform such tasks as tying shoes and tearing a piece of paper. Other complaints include intense pain experienced upon catching the thumb on an object, such as when reaching into a pants pocket.

Gamekeeper's thumb (also known as skier's thumb or UCL tear) is a type of injury to the ulnar collateral ligament (UCL) of the thumb. The UCL may be torn, damaged or in some cases avulsed from its insertion site into the proximal phalanx of the thumb in the vast majority (approximately 90%) of cases. This condition is commonly observed among gamekeepers and Scottish fowl hunters, as well as athletes (such as volleyballers). It also occurs among people who sustain a fall onto an outstretched hand, frequently skiers.

Finger injuries are usually diagnosed with x-ray and can get to be considerably painful. The majority of finger injuries can be dealt with conservative care and splints. However, if the bone presents an abnormal angularity or if it is displaced, one may need surgery and pins to hold the bones in place.

A "Jersey finger" is an injury to an FDP tendon at its point of attachment to the distal phalanx. This injury often occurs in American football when a player grabs another player's jersey with the tips of one or more fingers while that player is pulling or running away. The force of this action hyperextends the tip of the finger at the DIP joint while the proximal portion of the finger is flexed. This action can partially or completely rupture the FDP tendon at or near its attachment point on the distal phalanx. Sometimes, the force is great enough to pull off or avulse a piece of phalangeal bone to which the tendon can remain attached. Although it is a common football injury, this injury can occur during other sports or activities as well.

After the injury occurs, the torn FDP tendon may retract slightly, remaining in the finger near the PIP joint, or can retract more fully into the palm of the hand. A person who suffers a jersey finger injury in which the FDP tendon is completely ruptured cannot flex the affected digit at the DIP joint without assistance.

Signs and Symptoms include:

- A pop or rip felt in the finger at the time of the injury

- Pain when moving the injured finger and the inability to bend the DIPjoint

- Tenderness, swelling. and warmth of the injured finger

- Bruising after 48 hours

- Occasionally a lump felt in the palm of the finger

- Mallet finger deformity

Symptoms of Bennett fracture are instability of the CMC joint of the thumb, accompanied by pain and weakness of the pinch grasp. Characteristic signs include pain, swelling, and ecchymosis around the base of the thumb and thenar eminence, and especially over the CMC joint of the thumb. Physical examination demonstrates instability of the CMC joint of the thumb. The patient will often manifest a weakened ability to grasp objects or perform such tasks as tying shoes and tearing a piece of paper. Other complaints include intense pain experienced upon catching the thumb on an object, such as when reaching into a pants pocket.

The Jersey Finger is a finger-related tendon injury that is common in athletics and can result in permanent loss of flexion of the end of the finger if not surgically repaired.

This injury often occurs in American football when a player grabs another player's jersey with the tips of one or more fingers while that player is pulling or running away.

Pain and soft-tissue swelling are present at the distal-third radial fracture site and at the wrist joint. This injury is confirmed on radiographic evaluation. Forearm trauma may be associated with compartment syndrome. Anterior interosseous nerve (AIN) palsy may also be present, but it is easily missed because there is no sensory component to this finding. A purely motor nerve, the AIN is a division of the median nerve. Injury to the AIN can cause paralysis of the flexor pollicis longus and flexor digitorum profundus muscles to the index finger, resulting in loss of the pinch mechanism between the thumb and index finger. Galeazzi fractures are sometimes associated with wrist drop due to injury to radial nerve, extensor tendons or muscles.

Fractures of the fingers occur when the finger or hands hit a solid object. Fractures are most common at the base of the little finger (boxer's fracture).

Nerve injuries occur as a result of trauma, compression or over-stretching. Nerves send impulses to the brain about sensation and also play an important role in finger movement. When nerves are injured, one can lose ability to move fingers, lose sensation and develop a contracture. Any nerve injury of the hand can be disabling and results in loss of hand function. Thus it is vital to seek medical help as soon as possible after any hand injury.

Sprains result from forcing a joint to perform against its normal range of motion. Finger sprains occur when the ligaments which are attached to the bone are overstretched and this results in pain, swelling, and difficulty for moving the finger. Common examples of a sprain are jammed or twisted fingers. These injuries are common among ball players but can also occur in laborers and handy men. When finger sprains are not treated on time, prolonged disability can result.

A Stener lesion is a type of traumatic injury to the thumb. It occurs when the aponeurosis of the adductor pollicis muscle becomes interposed between the ruptured ulnar collateral ligament (UCL) of the thumb and its site of insertion at the base of the proximal phalanx. No longer in contact with its insertion site, the UCL cannot spontaneously heal.

The primary and most common symptom in patients with CMC OA of the thumb is pain. Pain at the base of the thumb is mainly experienced when moving the thumb or when applying pressure with the thumb. However, in advanced stages of CMC OA, pain might persist at rest. Another prominent symptom is loss of strength of the thumb. Patients struggle to grab or hold an object due to weakening of the thumb. For example, tying a knot or holding a saucepan becomes increasingly difficult.

If patients present themselves with similar symptoms, physicians should also consider De Quervain syndrome, rheumatoid arthritis or flexor carpi radialis and flexor pollicis longus tendinopathy as a possible cause.

Typical signs of CMC OA can be observed from the outside of the hand. For example, the area near the base of the thumb can be swollen and could appear inflamed. Advanced stages of CMC OA can eventually lead to deformity of the thumb. This deformity, also called a ‘zigzag’ deformity, is characterized by a deviation of the thenar eminence towards the middle of the hand, whilst the thumb phalanges overextend. Also a grinding sound, known as crepitus, can be heard when the CMC1 joint is moved.

Bennett fracture is a fracture of the base of the first metacarpal bone which extends into the carpometacarpal (CMC) joint. This intra-articular fracture is the most common type of fracture of the thumb, and is nearly always accompanied by some degree of subluxation or frank dislocation of the carpometacarpal joint.

Trapeziometacarpal osteoarthritis, also known as carpometacarpal (CMC) osteoarthritis (OA) of the thumb or osteoarthritis at the base of the thumb, is a reparitive joint disease affecting the first carpometacarpal joint (CMC1). This joint is formed by the trapezium bone of the wrist and the first metacarpal bone of the thumb. Because of its relative instability, this joint is a frequent site for osteoarthritis. Carpometacarpal osteoarthritis (CMC OA) of the thumb occurs when the cushioning cartilage of the joint surfaces wears away, resulting in damage of the joint.

The main complaint of patients is pain. Pain at the base of the thumb occurs when moving the thumb and might eventually persist at rest. Other symptoms include stiffness, swelling and loss of strength of the thumb. Treatment options include conservative and surgical therapies.

Galeazzi fractures account for 3-7% of all forearm fractures. They are seen most often in males. Although Galeazzi fracture patterns are reportedly uncommon, they are estimated to account for 7% of all forearm fractures in adults. They are associated with a fall on an outstretched arm.

Stenosing tenosynovitis often presents with a painful and swollen thumb with limited range of motion, or a ring finger or middle finger with similarly limited motion. There is often a feeling of catching when the thumb is flexed. In the ring and middle fingers, often a nodule can be felt when you press the area of the hand where the palm meets the finger.

Swan neck deformity has many possible causes arising from the DIP, PIP, or even the MCP joints. In all cases, there is a stretching of the volar plate at the PIP joint to allow hyperextension, plus some damage to the attachment of the extensor tendon to the base of the distal phalanx that produces a hyperflexed mallet finger. Duck bill deformity is a similar condition affecting the thumb (which cannot have true swan neck deformity because it does not have enough joints).

Injuries to the arm, forearm or wrist area can lead to various nerve disorders. One such disorder is median nerve palsy. The median nerve controls the majority of the muscles in the forearm. It controls abduction of the thumb, flexion of hand at wrist, flexion of digital phalanx of the fingers, is the sensory nerve for the first three fingers, etc. Because of this major role of the median nerve, it is also called the eye of the hand. If the median nerve is damaged, the ability to abduct and oppose the thumb may be lost due to paralysis of the thenar muscles. Various other symptoms can occur which may be repaired through surgery and tendon transfers. Tendon transfers have been very successful in restoring motor function and improving functional outcomes in patients with median nerve palsy.

Trigger fingers is a common disorder characterized by catching, snapping or locking of the involved finger flexor tendon, associated with dysfunction and pain. It is a sub-set of stenosing tenosynovitis.

A disparity in size between the flexor tendon and the surrounding retinacular pulley system, most commonly at the level of the first annular (A1) pulley, results in difficulty flexing or extending the finger and the "triggering" phenomenon. The label of trigger finger is used because when the finger unlocks, it pops back suddenly, as if releasing a trigger on a gun.

Stenosing tenosynovitis (also known as trigger finger or trigger thumb) is a painful condition caused by the inflammation (tenosynovitis) and progressive restriction of the superficial and deep flexors fibrous tendon sheath adjacent to the A1 pulley at a metacarpal head. Repetitive forceful compression, tensile stress, and resistive flexion, causes inflammation, swelling, and microtrauma, that results in thickening (commonly a nodular formation) of the tendon distal to the pulley and stenosis of the tendon sheath leading to a painful digital base, limitation of finger movements, triggering, snapping, locking, and deformity progressively.

Patients report a popping sound at the proximal interphalangeal joint (PIP), morning stiffness with/without triggering, delayed and sometimes painful extension of the digit, and when more advanced, a locking position that requires manipulation to extend the affected finger. This condition more commonly affects the middle and ring fingers (occasionally the thumb), and the flexor rather than extensor tendons in the hand.

In rheumatic trigger finger (or in diabetes), more than one finger may be involved. Cases of stenosing peroneal tenosynovitis, have been reported where the patient presents with pain over the lateral malleolus, both with active and passive range of motion and no physical of radiographic evidence of instability.

Swan neck deformity is a deformed position of the finger, in which the joint closest to the fingertip is permanently bent toward the palm while the nearest joint to the palm is bent away from it (DIP flexion with PIP hyperextension). It is commonly caused by injury or inflammatory conditions like rheumatoid arthritis or sometimes familial (congenital, like Ehlers-Danlos syndrome).

Classification of radial dysplasia is practised through different models. Some only include the different deformities or absences of the radius, where others also include anomalies of the thumb and carpal bones. The Bayne and Klug classification discriminates four different types of radial dysplasia. A fifth type was added by Goldfarb et al. describing a radial dysplasia with participation of the humerus. In this classification only anomalies of the radius and the humerus are taken in consideration. James and colleagues expanded this classification by including deficiencies of the carpal bones with a normal distal radius length as type 0 and isolated thumb anomalies as type N.

Type N: Isolated thumb anomaly

Type 0: Deficiency of the carpal bones

Type I: Short distal radius

Type II: Hypoplastic radius in miniature

Type III: Absent distal radius

Type IV: Complete absent radius

Type V: Complete absent radius and manifestations in the proximal humerus

The term absent radius can refer to the last 3 types.

CS Campbell, an orthopedic surgeon, originally coined the term "gamekeeper's thumb" in 1955, after he observed this condition in a number of Scottish gamekeepers. The injury appeared to occur as a result of the particular manner in which they killed small animals such as rabbits. Specifically, the animals were placed on the ground, and their necks were broken as the gamekeeper exerted downward pressure with the thumb and index fingers. This maneuver would place a valgus force upon the abducted metacarpophalangeal (MCP) joint. Over time, this would lead to insufficiency of the ulnar collateral ligament of the thumb, a condition which Campbell referred to as "gamekeeper's thumb".

In 1962, Bertil Stener described a lesion which he observed to occur in a subset of patients suffering from gamekeeper's thumb. In these patients, the distal attachment of the UCL was traumatically avulsed from its site of insertion at the base of the proximal phalanx of the thumb. The severed end of the ligament would become trapped under the aponeurosis of the adductor pollicis muscle and therefore be unable to return to its proper anatomic position. Consequently, the severed ligament would fold on itself and thus be prevented from healing and restoring stability to the MCP joint.

For a Stener lesion to occur, both the proper and accessory collateral ligaments of the thumb must be completely ruptured. The Stener lesion is present in more than 80% of complete ruptures of the UCL of the thumb.

Symptoms are pain at the radial side of the wrist, spasms, tenderness, occasional burning sensation in the hand, and swelling over the thumb side of the wrist, and difficulty gripping with the affected side of the hand. The onset is often gradual. Pain is made worse by movement of the thumb and wrist, and may radiate to the thumb or the forearm.

De Quervain syndrome, is a tenosynovitis of the sheath or tunnel that surrounds two tendons that control movement of the thumb.

Radial dysplasia, also known as radial club hand or radial longitudinal deficiency, is a congenital difference occurring in a longitudinal direction resulting in radial deviation of the wrist and shortening of the forearm. It can occur in different ways, from a minor anomaly to complete absence of the radius, radial side of the carpal bones and thumb. Hypoplasia of the distal humerus may be present as well and can lead to stiffnes of the elbow. Radial deviation of the wrist is caused by lack of support to the carpus, radial deviation may be reinforced if forearm muscles are functioning poorly or have abnormal insertions. Although radial longitudinal deficiency is often bilateral, the extent of involvement is most often asymmetric.

The incidence is between 1:30,000 and 1:100,000 and it is more often a sporadic mutation rather than an inherited condition. In case of an inherited condition, several syndromes are known for an association with radial dysplasia, such as the cardiovascular Holt-Oram syndrome, the gastrointestinal VATER syndrome and the hematologic Fanconi anemia and TAR syndrome. Other possible causes are an injury to the apical ectodermal ridge during upper limb development, intrauterine compression, or maternal drug use (thalidomide).

Because lesions to different areas of the median nerve produce similar symptoms, clinicians perform a complete motor and sensory diagnosis along the nerve course. Decreased values of nerve conduction studies are used as indicators of nerve compression and may aid in determining the localization of compression.

Palpation above the elbow joint may reveal a bony consistency. Radiography images may show an abnormal bony spur outgrowth (supracondyloid process) just proximal to the elbow joint. Attached fibrous tissue (Struthers' ligament) may compress the median nerve as it passes underneath the process. This is also known as supracondylar process syndrome. Compression at this point may also occur without the bony spur; in this case, aponeurotic tissue found at the location of where Struthers' ligament should be is responsible for the compression.

If patients mention reproduction of symptoms to the forearm during elbow flexion of 120–130 degrees with the forearm in maximal supination, then the lesion may be localized to the area underneath the lacertus fibrosus (also known as bicipital aponeurosis). This is sometimes misdiagnosed as elbow strain and medial or lateral epicondylitis.

A lesion to the upper arm area, just proximal to where motor branches of forearm flexors originate, is diagnosed if the patient is unable to make a fist. More specifically, the patient's index and middle finger cannot flex at the MCP joint, while the thumb usually is unable to oppose. This is known as hand of benediction or Pope’s blessing hand. Another test is the bottle sign—the patient is unable to close all their fingers around a cylindrical object.

Carpal tunnel syndrome (CTS) is caused by compression of the median nerve as it passes under the carpal tunnel. Nerve conduction velocity tests through the hand are used to diagnosis CTS. Physical diagnostic tests include the Phalen maneuver or Phalen test and Tinel's sign. To relieve symptoms, patients may describe a motion similar to "shaking a thermometer", another indication of CTS.

Pronator teres syndrome (also known as pronator syndrome) is compression of the median nerve between the two heads of the pronator teres muscle. The Pronator teres test is an indication of the syndrome—the patient reports pain when attempting to pronate the forearm against resistance while extending the elbow simultaneously. The physician may notice an enlarged pronator teres muscle. Tinel's sign the area around the pronator teres heads should be positive. The key to discerning this syndrome from carpal tunnel syndrome is the absence of pain while sleeping. More recent literature collectively diagnose median nerve palsy occurring from the elbow to the forearm as pronator teres syndrome.

In uncooperative patients, the skin wrinkle test offers a pain-free way to identify denervation of the fingers. After submersion in water for 5 minutes, normal fingers will become wrinkled, whereas denervated fingers will not.

In "Ape hand deformity", the thenar muscles become paralyzed due to impingement and are subsequently flattened. This hand deformity is not by itself an individual diagnosis; it is seen only after the thenar muscles have atrophied. While the adductor pollicis remains intact, the flattening of the muscles causes the thumb to become adducted and laterally rotated. The opponens pollicis causes the thumb to flex and rotate medially, leaving the thumb unable to oppose. Carpal tunnel syndrome can result in thenar muscle paralysis which can then lead to ape hand deformity if left untreated. Ape hand deformity can also be seen in the hand of benediction deformity.

The Anterior Interosseus Nerve (AIN), a branch of the median nerve, only accounts for the movement of the fingers in hand and does not have any sensory capabilities. Therefore, the AIN syndrome is purely neuropathic. AINS is considered as an extremely rare condition because it accounts for less than 1% of neuropathies in the upper limb. Patients suffering from this syndrome have impaired distal interphalangeal joint, because of which they are unable to pinch anything or make and "OK" sign with their index finger and thumb. The syndrome can either happen from pinched nerve, or even dislocation of the elbow.