Wrist Pain

<中文版>

Wrist pain simply means pain over wrist area.  The wrist joint consists of the distal radius, distal ulnar, 8 small carpal bones, complex ligaments structures, tendons and cartilages.

Definition:

Wrist pain simply means pain over wrist area.  The wrist joint consists of the distal radius, distal ulnar, 8 small carpal bones, complex ligaments structures, tendons and cartilages.  Therefore, pain over the wrist may have many different causes. Musculoskeletal physicians will define whether the wrist pain is due to joint inflammation or from localized wrist injury.

Symptoms and signs:

Apart from wrist pain, patient usually gives history of difficulty in performing certain tasks or wrist movements. There may be weakness in the hand grip and patient may complain of problems in twisting a towel or in hand-writing. If there is a history of morning stiffness or multiple joint pain especially after prolong rest and at night time, rheumatoid diseases should be considered as one of the differential diagnosis. If the pain is associated with wrist movements and there is a history of either previous wrist injury or hand overuse, localized wrist injury is usually the cause. Musculoskeletal physicians will take a detail history to work up for the most probable cause.  At the same time, he/she will also note the dexterity of the patient as well as the impact of the wrist pain on patient’s activities of daily living and occupation.

A musculoskeletal examination shall follow ‘look, feel, move and special tests’. Local redness, swelling or bruising should be documented. If pain is due to past injury, the skin temperature will be the same between two sides. Increase in warmth with swelling is a pointer to inflammatory diseases or acute injury. If the painful wrist is colder, one shall consider vascular causes, such as arteritis obliterans or regional complex syndrome. Range of the movements including wrist flexion, extension, ulnar deviation, radial deviation, supination and pronation shall be noted. When pain is on the radial side, thumb movements shall also be defined. The radial styloid process, thumb ulnar collateral ligament, distal radio-ulnar joint, ulnar styloid process and the carpal bones, particularly scaphoid, and the first carpometacarpal joint shall be palpated for local tenderness. The carpal ligaments will be stressed to pick up ligament laxity and carpal bone instability. Special test(s) shall be performed to confirm the diagnostic hypothesis. Common special tests include Phalen’s test, Tinel sign for carpal tunnel syndrome, Finkelstein test for DeQuervain's tenosynovitis, Piano key test for distal radioulnar joint laxity, Watson’s test forscapholunate dissociation, lunotriquetral ballotment test for lunate triquetrum dissociation, and the TFCC grinding test for injury to the triangular fibro-cartilage complex at the distal ulnar. When nerve injury is suspected, individual muscle strength and finger sensory shall be checked.

Causes and biomechanics considerations:

Wrist pain may be grouped under 3 main causes:

1. Mechanical causes
2. Neurological or Referred pain
3. Systematic causes

Mechanical wrist pain implies that the pain comes with wrist movement.  These can be caused by movement involving injured or deformed wrist structures like wrist bone, ligaments, tendons or cartilage or by faulty wrist joint movement. Bony causes include fracture of wrist bones, non-union of fracture and avascular necrosis of carpal bones. Ligament injuries may lead to carpal bones subluxation, dissociation or instability that result in faulty joint movement. De Quervain’s tendinitis and extensor carpi ulnaris tendonitis are the two common tendinopathy presented with wrist pain. Triangular fibrocartilage complex (TFCC) is, sometimes, injured when patient falls with out-stretched hand and presents with persistent ulnar wrist pain.

Wrist pain can be caused directly or referred from compressed nerves.  Cervical radiculopathy and thoracic outlet syndrome can cause pain referring to the wrist.  Direct compression of the median nerve at the carpal tunnel and compression of the ulnar nerve at the Guyon’s canal syndrome can cause wrist pain and finger numbness.

Systemic causes of wrist pain may be autoimmune, metabolic, infective, hematological, or neurologic.  Examples are rheumatoid arthritis, gouty arthritis, osteomyelitis, haemarthrosis and regional chronic pain syndrome.

Investigations:

X-ray is the first line investigation for wrist pain. It is useful to diagnose bone fractures as well as non-union or mal-union of carpal bones. Point worth noting is that subtle carpal bone fractures may not be visible on day of injury. It is important to repeat the X-ray in 2 weeks because by that time the fracture will be made more visible by the calcification around the fracture lines. Joints instability and dissociation can be confirmed by X-ray with special manoeuvres. Ultrasonography is a non-invasive investigation which is effective in diagnosing soft tissues pathologies, such as differentiating tendonitis from tendonosis (because treatments are different), tendon or ligaments rupture, some of the cartilage damage, ganglions, synovial thickening and cysts. Colour Doppler can be very helpful in showing acute inflammation. Bone scan is effective in picking up early stress fracture and subtle scaphoid fractures.  CT can identify carpal bones fractures and articular subluxations which are not seen by routine radiography.  MRI is particularly useful in picking up soft tissues injury, like ligament tears and cartilage injury.  A musculoskeletal physician will be able to pick up the most appropriate and cost effective investigation to get to the final diagnosis. Sometimes, blood tests including autoimmune diseases markers are required to define the cause of wrist pain if rheumatic diseases are suspected.

Treatments:

Management shall be planned according to the diagnosis. Non-steroidal anti-inflammatory drugs (NSAIDs) are useful to treat tendinitis or arthritis. Manual mobilization or manipulation helps to realign the subluxed carpal bones. Splintage or wrist support may be required to stabilize the wrist joint. Prolotherapy is very effective in strengthening the weaken ligaments, tendonosis and damaged cartilages.  Physiotherapy is helpful to restore normal hand function. Occasionally, surgery is required to release nerve compression or to repair the bony or cartilaginous damages.

腕痛症

腕痛症即發生於手腕部位的疼痛。腕關節是由尺/橈骨遠端，8塊腕骨，複雜的韌帶組織，肌腱和軟骨組成。

定義:

腕痛症即發生於手腕部位的疼痛。腕關節是由尺/橈骨遠端，8塊腕骨，複雜的韌帶組織，肌腱和軟骨組成。腕部疼痛可以有很多原因，肌骼科醫生要判斷腕部疼痛是由於發炎還是受傷造成。

症狀與表徵:

腕痛症患者除腕部疼痛外，通常不能正常執行某些功能，如握拳無力和扭毛巾或寫字困難。 若有晨僵或多發性關節痛，要考慮與類風濕病鑒別；若疼痛與運動有關，且有腕部外傷和手部過勞史，則腕痛是由損傷造成。肌骼科醫生應通過詳細的病史來找出最可能的病因。同時，也應瞭解患者手的靈活度及腕痛對其日常生活和工作的影響。

肌骼檢查應按照'望，觸，動和特殊檢查'的步驟來進行。應記錄局部是否有紅、腫或瘀斑。由舊傷造成的疼痛不伴有皮膚溫度的改變，若皮溫升高伴腫脹則提示炎症或急性損傷。而觸之冰冷，應考慮血管疾病，如閉塞性動脈炎或複合性區域疼痛綜合症。注意腕部的活動範圍包括屈，伸，尺偏，橈偏，旋前，旋後。橈側的腕部疼痛，要留意拇指的活動。觸診橈骨莖突，拇指尺側副韌帶，遠端尺橈關節，尺骨莖突和腕骨，尤其是舟狀骨，以及第一腕掌關節以發現局部壓痛。特殊檢查有助於確定診斷。常用特殊檢查包括以 Phalen's 試驗，Tinel 徵，診斷腕管綜合症；以 Finkelstein 試驗診斷橈骨莖突狹窄性腱鞘炎；以 Piano key 試驗診斷遠端尺橈關節鬆弛；以 Watson's 試驗診斷舟月骨分離；以月/三角骨的衝擊觸診診斷月/三角骨分離；以 TFCC 研磨試驗診斷尺骨遠端的三角纖維軟骨複合體 (TFCC) 損傷。若懷疑神經損傷，要分別檢查各組肌肉的肌力和手指感覺。

病因和生物力學因素:

腕痛症的病因可分為三類:

1. 機械因素
2. 神經或放射痛
3. 系統性疾病

機械性腕部痛是指由腕部活動造成的疼痛。因為腕部活動時會涉及受損或異常的腕關節結構如，骨骼，韌帶，肌腱及軟骨，所以造成疼痛；而腕關節的異常活動也可造成疼痛。骨骼因素包括骨折，骨不連接和腕骨的缺血性壞死。韌帶損傷會導致腕骨半脫位，分離或不穩定，從而關節活動異常。橈骨莖突狹窄性腱鞘炎和尺側腕伸肌腱炎是腕痛常見的兩個原因。三角纖維軟骨複合體(TFCC)有時因跌倒時，手以外伸狀態著地而受傷，並引起腕部持續性疼痛。

腕部疼痛可因腕部神經受壓直接引起疼痛，也可是來自遠位受壓神經的放射痛。頸髓神經根病變和胸廓出口綜合征均可引腕部放射痛。腕管的正中神經和位於 Guyon's 管的中尺神經可因直接受壓導致腕部疼痛及手指麻木。

造成腕部疼痛的系統性疾病可以是免疫，代謝，感染，血液或神經等方面的疾病。如類風濕性關節炎，痛風性關節炎，骨髓炎，關節積血和區域慢性痛綜合症。

實驗室檢查:

X光檢查是腕部疼痛的首選檢查。用於診斷骨折，骨不連接或連接不良。值得指出的是細小的腕骨骨折在受傷當日並不明顯，所以兩星期後的重復X光檢查非常重要，因為骨折線周圍鈣化使得骨折在X光下變得明顯。關節不穩定和分離可用X光的特殊手法檢查顯示出來。超聲波檢查是非入侵性的檢查，可有效診斷軟組織病變如肌腱病，腱鞘囊腫，滑膜增厚和滑膜囊腫。骨掃描可用於發現早期應力性骨折和細小的舟狀骨骨折。普通X光不能確定的腕骨骨折和關節半脫位可用 CT 來確定。而MRI 則專門用來診斷軟組織損傷如韌帶，軟骨的損傷。肌骼科醫生應該選擇最具有成本效益的診斷方法作最終的診斷。有時也需要進行血液檢查以確明腕部疼痛的病因，若懷疑風濕病，則需作免疫系統標記物的檢測。

治療:

治療應根據診斷來決定。非類固醇抗炎藥(NSAIDs)可有效治療肌腱炎或關節炎。手法舒整治療有助半脫位的腕骨復位。夾板或腕托可用來穩定腕關節。保絡療法可有效強化鬆弛的韌帶，從而恢復手的正常功能。偶而，也需要手術來鬆解被壓的神經或修復受損的骨或軟骨。