The triangular fibrocartilage complex (TFCC) is a bundle of ligaments that connects the radius and ulna with the carpal bones of the wrist. The TFCC is often subject to traumatic injuries and ligament degeneration compromising the movement of the wrist.
The TFCC if made by multiple ligaments and cartilage tissue forming a triangular shape and is located at the little finger side of the wrist. It stabilises the wrist and allows the complexity of wrist movements in different directions (bending, straightening, twisting, lateral movement). TFCC injuries consist in tears of the articular disc and meniscus homologue. The meniscus homologue connects the articular disc to the carpal bone triquetrum and acts like an elastic band between these structures. Injuries to the TFCC can be mild and considered as a wrist sprain. When a severe tear, rupture or degeneration of the TFCC occur, the consequences can be seriously debilitating. With a severe impact, an injury to the TFCC can be associated with a distal ulnar fracture or a fracture to the ulnar fovea. This is a concave region of the ulnar head, which forms a gap with the ulnar styloid, the protruding tip of the ulna.
TFCC injuries are classified with two systems depending on the aetiology:
Class 1: Traumatic injury
Central perforation (tear)
Ulnar separation (avulsion) with or without distal ulnar fracture
Radial avulsion with or without sigmoid notch fracture
Class 2: Degenerative changes (Palmer classification)
TFCC wear with lunate and/or ulnar chondromalacia (= cartilage degeneration)
TFCC perforation with lunate and/or ulnar chondromalacia
TFCC perforation with lunate and/or ulnar chondromalacia and luno-triquetral ligament perforation
TFCC perforation with lunate and/or ulnar chondromalacia, luno-triquetral ligament perforation and ulno-carpal arthritis.
These fractures are divided into:
Anterior pillar (not weight bearing part of joint)
Posterior pillar (often associated with dislocation of the hip including the weight bearing part of joint)
Comminuted involving both column type
Sacral / coccygeal fractures
The sacrum is a triangular-shaped bone formed by 5 fused vertebrae, which provide a posterior wall to the pelvic ring. At each side of the sacrum, the ala structures articulate with the ilium bones forming the sacro-iliac joints. Sacral fractures are usually parallel to the spine and can involve the ala. Less frequently sacral fractures may display an “H” shape, including a transversal fracture uniting both sides of the sacrum. Three zones are described where sacral fractures can occur that are along vertical lines relative to the alignment of the foramina. Sacral fractures may result in sacral instability and require treatment via sacroplasty (injection of bone glue into the fracture). Surgery is necessary in case of associated neurological symptoms.
Fractures of the coccyx involve the tailbone, the terminal portion of the spine situated below the sacrum formed by 3 to 5 fused vertebrae. Coccyx fractures occur when falling on a seated position. They are more common in elderly women and seldom require surgical treatment.
A TFCC injury is mainly caused by a traumatic impact when falling on the outstretched hand while having the wrist in hyperextension. This is often seen in young athletes and gymnasts. Other injuries occur when operating construction equipment such as power drills. Other causes for TFCC injuries include wrist overuse with repetitive flexion or pronation of the hand associated with heavy loads. In the elderly, the ligaments of the TFCC undergo spontaneous degeneration.
Some activities increase the risk for TFCC injury such as:
Sports (gymnastics, tennis, baseball)
Manoeuvring vibrating power drills
Ageing due to weakening of the ligaments
Congenital conformation of the wrist anatomy: longer ulna styloid process producing excessive pressure on the TFCC
The symptoms arising from TFCC injuries include:
Sharp pain mostly felt at the little finger side of the wrist
Pain worsening when moving the wrist particularly with external wrist rotation
Clicking and popping noises
Feeling of wrist instability
Wrist bending to the ulnar side (ulnar deviation)
Pronounced bone protuberance on the ulnar side (ulnar dislocation and complete TFCC tear)
The diagnosis of TFCC injury is complicated by the similarity of symptoms common to other wrist pathologies. Medical history focuses on previous wrist dislocations and injuries. Clinical examination is based on specific tests:
Ulnar fovea sign: is useful for foveal disruption of the distal radio-ulnar ligaments and injuries to the ulna-triquetral ligament. Tenderness and pain during this test is a sign of a split-tear injury. These injuries are more common with lower energy, repetitive torque impact such as in bowling or golfing.
Press test: the patient is asked to rise from a chair by pressing the hands on the armrests. This will cause pain and feeling of weakness in the wrists.
McMurray’s test: the examiner moves the lunate and triquetrum up and down in the wrist, while the wrist is ulnarly deviated. With a TFCC tear the patient feels pain and snapping noise.
Piano key test: the examiner holds the wrist at the radius and gently moves the wrist up and down. The ulna is pressed down, like a piano key. If a TFCC tear is present the ulna moves excessively and does not return to normal position.
Load Test: the examiner holds the patient’s hand in a ‘hand shake position’ and ulnarly deviates the wrist, compressing the TFCC and subsequently rotating the wrist through an arc. If positive, the test results in crepitus, clicking and pain.
X-rays are taken in case of suspected fracture to the ulna and radius, which are often associated with traumatic disruption of the TFCC. However, with a negative X-ray, the diagnosis may not be conclusive. A MRI will allow for better detection of a TFCC tear and classification. Nowadays wrist arthroscopy may be used to directly visualise the origin of the pathology in situ. Arthrography is an additional procedure consisting in the injection of a dye in the wrist joint. With a TFCC tear the dye will diffuse through the wrist structures. However, this method lacks specificity.
The management of TFCC injuries varies in relation to the severities and characteristics. If the wrist is stable and the TFCC tear incomplete, conservative care is advised and consists of wrist immobilisation with a cast or splint for 4 to 6 weeks followed by rehabilitation for up to 12 weeks. In case of a fracture in the lower portion of the scaphoid surgery is not required and treatment with a cast is sufficient. The cast is placed either below the elbow, possibly including the thumb, or beyond the elbow. Additional conservative treatments include:
Local steroid injection
Physiotherapy while the arm is in a cast or brace
Surgery is required to repair a complete tear of the TFCC or when a TFCC pathology is associated injuries to the wrist. This can be achieved via open surgery; however, the preferred method nowadays is arthroscopy.
Arthroscopic surgery is used to repair torn ligaments and remove the cartilage fragments of the meniscal homologue that may impair the wrist movement. This procedure is defined arthroscopic debridement. With more severe TFCC rupture, the ligaments can be reattached with wires and screws.
Open surgery is preferred in case of TFCC injuries in concomitance with radio-ulnar ligament tear and joint instability and/or presence of bone fractures that require fixation. With a delayed intervention from the injury time, the retracted injured ligament(s) has to be replaced with a graft. In degenerative TFCC damage, surgery involves the shortening of the ulnar bone using two methods:
Ulnar (diaphyseal) shortening
Distal ulnar head osteotomy (Feldon wafer method)
After surgery a cast or splint is worn for a week and replaced with a fiberglass cast for 6 weeks.
Physical therapy will focus on restoring wrist function with specific activities such as ulnar deviation as well as hand supination (palm up) and pronation (palm down). To prevent joint stiffness, it is critical to maintain wrist movement and begin physical therapy soon after the injury has healed, approximately 6-8 weeks after surgery. Occasionally, pain and wrist stiffness may remain. Standard rehabilitative therapy includes:
Antiinflammatory therapy NSAIDs
Taping / bracing
Return to activity plan
The main preventative objective is reducing the risk of falls and protect the wrist during sport that put strain on the wrists. Other common strategies are:
Correct use of sports equipment (tennis racquets)
Modification of physical activities by an occupational therapist
Exercise to improve muscle strength, flexibility and posture
Use of devices to improve elderly patient stability and avoid falls
Modification of physical activities