Continuing Education Activity

The triangular fibrocartilage complex (TFCC) is a load-bearing structure between the lunate, triquetrum, and ulnar head. The function of the TFCC is to act as a stabilizer for the ulnar aspect of the wrist. The TFCC is at risk for either acute or chronic degenerative injury. Forced ulnar deviation and positive ulnar variation carry associations with injuries to the TFCC. Patients with TFCC injury will present with ulnar-sided wrist pain that may present with clicking or point tenderness between the pisiform and the ulnar head. MRI imaging is useful as a preliminary diagnostic tool; arthroscopy is the diagnostic gold standard. Treatment options include conservative therapies such as rest, NSAIDs, corticosteroid injections, and operative management. This activity reviews the evaluation and management of TFCC injuries and highlights the interprofessional team's role in caring for affected patients.

Objectives:

• Describe a patient history consistent with triangular fibrocartilage complex injury.
• Describe the physical exam consistent with triangular fibrocartilage complex injury.
• Describe the role of imaging in triangular fibrocartilage complex injury.
• Describe the interprofessional team management of triangular fibrocartilage complex injuries, including the role of surgery and the importance of post-operative care in order to avoid complications.

Introduction

The triangular fibrocartilage complex (TFCC) is a load-bearing structure between the lunate, triquetrum, and ulnar head. The function of the TFCC is to act as a stabilizer for the ulnar aspect of the wrist. The TFCC is at risk for either acute or chronic degenerative injury. Forced ulnar deviation and positive ulnar variation carry associations with injuries to the TFCC. Patients with TFCC injury will present with ulnar-sided wrist pain that may present with clicking or point tenderness between the pisiform and the ulnar head. MRI imaging is useful as a preliminary diagnostic tool; arthroscopy is the diagnostic gold standard. Treatment options include conservative therapies such as rest, NSAIDs, corticosteroid injections, and operative management.

Etiology

TFCC injury often occurs when a load is compressed on the TFCC while the wrist is in ulnar deviation. Common causes of forced ulnar deviation include swinging a racket or a bat. TFCC injury is also associated with positive ulnar variance; this is when the articular surface of the ulna is more distal than the articular surface of the radius. Positive ulnar variance is often due to prior surgery or prior fracture.

Epidemiology

One study found the prevalence of TFCC injuries increases with age. The authors found a 49% prevalence in patients age 70 or older and a prevalence of 27% in patients age 30 or younger.[1] Another study found a similar prevalence in patients younger than 30, but they also demonstrated that the prevalence of TFCC injury was similar in patients with ulnar-sided pain compared to patients who had wrist imaging for reasons other than ulnar-sided pain.[2] This research suggests that not all TFCC injuries cause ulnar-sided pain.

Pathophysiology

Anatomically the TFCC includes the triangular fibrocartilage disc, extensor carpi ulnaris tendon subsheath, ulnotriquetral and ulnolunate ligaments, dorsal and volar distal radioulnar ligaments, meniscal homolog, and the ulnocarpal collateral ligament. The triangular fibrocartilage disc attachment on the radial side is to hyaline cartilage, making this weaker than the ulnar side’s bony attachment.[3]

Positive ulnar variation can leave the TFCC vulnerable to injury. Ulnar variation will decrease with supination and increase with pronation. Small changes in ulnar length have been shown to have substantial effects on the amount of load to the ulna.[4] The extensor carpi ulnaris relies on the TFCC for movement, and thus alteration of the motion of the extensor carpi ulnaris may lead to abnormal force through the TFCC, predisposing it to injury.[5]

Histopathology

The histopathology of the components of the TFCC can be broken down as follows[6]:

• Triangular fibrocartilage disc: fibrocartilage with blood vessels on the ulnar aspect; otherwise, this structure is avascular
• Extensor carpi ulnaris tendon sub-sheath: a combination of loose and tight parallel collagen
• Ulnotriquetral and ulnolunate ligaments: a combination of loose and tight parallel collagen. The ulnolunate has less elastic fibers than the ulnotriquetral
• Dorsal and volar distal radioulnar ligaments: parallel collagen bundles
• Meniscal homolog: the majority is composed of loose connective tissue

History and Physical

Patients will complain of ulnar-sided wrist pain that often gets worse with activity. There may also be a weakness in the grip, instability, or clicking. There are some elements of history that can occur in conjunction with individual sports. For example, baseball-specific acute injury can be due to forced wrist extension while doing a head-first slide or when a hitter attempts to hit an inside pitch and gets “jammed.” Chronic injury can occur in baseball players as a result of the heavy load placed on the wrist during the swing. These athletes can sustain TFCC injuries even if they do not have positive ulnar variance.[7]

If patients have distal radioulnar joint (DRUJ) instability, this is associated with weakness in pronation and supination, which may also be a feature with TFCC injury.[8]

On exam, palpation of the TFCC is best with the wrist in pronation. It is between the flexor carpi ulnaris, ulnar styloid, and os pisiform. Several physical exam tests can suggest the diagnosis of TFCC injury. These include:

• TFCC compression test: forearm in the neutral position with ulnar deviation reproduces symptoms
• TFCC stress test: applying a force across the ulna with the wrist in ulnar deviation reproduces symptoms
• Press test: Patient lifts themselves out of a chair using the wrists in an extended position. Pain indicates a positive test.
• Supination test: The patient grabs the underside of a table with the forearms supinated; this causes a load on the TFCC and dorsal impingement, which will cause pain if there is a peripheral, dorsal tear.
• Piano key test: Place both hands on an exam table and press the palms on the table. If the distal ulna is prominent on the affected side, this suggests distal radioulnar joint instability, which can have associations with TFCC injury. If the palms are relaxed and the ulnar head goes back to normal position, this is a positive test.
• Grind test: Compress the radius and ulna and have the patient rotate the forearm. Pain could indicate a degenerative process.

Evaluation

Initial workup typically starts with a radiograph to evaluate for fracture and assess for ulnar variance. The next step will often be to get an MRI with or without an arthrogram. Recent data suggest MR arthrogram is minimally better but arguably not worth doing instead of MRI given the increased discomfort and cost associated with MRA.[9] If MR is unavailable or contraindicated, a CT can be an option, although the sensitivity is less than MRI. Arthroscopy is the most accurate means by which to diagnose TFCC injury.

Determining if the lunotriquetral ligament is intact or torn is crucial to guide treatment options; this can be via radiograph by looking for a volar tilt of the scaphoid and lunate. Alternatively, an arthrogram showing communication of contrast or direct visualization of the tear are other ways to diagnose lunotriquetral ligament tears.

One study of 85 patients with distal radius fractures treated surgically found that 53% of the patients also had a TFCC lesion diagnosed by arthroscopy. However, they found no correlation between TFCC lesion and any specific parameter on x-ray. Therefore, the initial radiograph of a distal radius fracture is not predictive of TFCC injury.[10]

Treatment / Management

Initial treatment includes rest, physical therapy, and corticosteroid injections. The length of time to attempt conservative treatment before advancing to surgical options varies. Six months of conservative treatment is reasonable if there is not DRUJ instability.

There is limited evidence to support the use of bracing as a treatment option for TFCC tears. One case report followed one patient with a TFCC tear for one year. This patient wore a new brace for 12 weeks after failing conservative management as an alternative to surgery. The results were an increase in upper extremity use immediately following wearing the brace and persistent improvements noticed at a follow-up appointment in one year. This was the first study to show a beneficial non-surgical option after failing conservative management.[11] Further information is necessary regarding the utility of bracing for TFCC.

Surgical options should be a consideration if conservative treatment fails or if there is DRUJ instability. Common surgical options include arthroscopic repair, arthroscopic debridement, ulnar shortening, and the Wafer procedure.

A debridement is a surgical option that induces bleeding to stimulate healing. Debridement has beneficial outcomes for central TFCC tears but has been shown to have worse outcomes in degenerative tears or patients with higher positive ulnar variance.[12] Regarding the arthroscopic vs. open approach, there is no significant difference in pain, reoperation rate, grip strength, or range of motion between the two approaches.[13]

Surgical treatment will depend on the Palmer classification of the injury, discussed in the staging section.

1A: This injury is in an avascular region that will not heal if it does not receive treatment. Due to the lack of vascularity, it does not respond to direct surgical management, so debridement is the intervention of choice.[3]

1B: The area has vascularization, so a direct surgical repair is an option. If the triangular fibrocartilage disc is completely detached from the ulnar insertion, then there is an injury to the radioulnar ligaments, and there will be instability. If this is the case, the amount of retraction of the tendon should be measured, and a tendon graft may be necessary as part of the surgical repair. Partial tears would not involve radioulnar ligament injury and thus are stable and could be treated with sutures arthroscopically. Tears at the foveal insertion require bony reattachment, and therefore these are of more significant consequence than styloid insertion tears.[3]

1C: Arthroscopy and debridement are both options. Debridement is an option if the ligaments are beyond repair.[3]

1D:  If the injury involves radioulnar ligament damage, surgical reattachment is the treatment of choice. If the injury spares the radioulnar ligaments, partial resection via arthroscopy is an option.[3]

Type 2 lesion treatment is separated by whether the lunotriquetral ligament is torn or intact. The best way to determine this is MR arthrography, although CT arthrography is also effective. Types 2A, 2B, and 2C lesions can have conservative therapy. If conservative management fails, a reasonable next step is the Wafer procedure, which is resection of the distal aspect of the ulnar head. Type 2E lesions can also be treated by resection of the ulnar head. Type 2D lesions can be treated via ulnar shaft-shortening with osteotomy.[3]

For patients with chronic tears who undergo surgery, one study of 57 patients who had pain for nine months on average prior to surgery found a 98% satisfaction and return to work around nine weeks.[14]

Contraindications to arthroscopy include if the radiocarpal joint is an arthritic or insufficient ligament on the scaphoid and lunate.[14]

Treating athletes can vary from treatment for non-athletes. A high school athlete who will not compete beyond high school should begin with four weeks of rest, ice, and anti-inflammatories.  For elite athletes, if there is no distal radioulnar joint instability, one week of rest with splinting and re-examination after one week is reasonable. If there is a tear of the TFCC with instability of the distal radioulnar joint, this is potentially career-threatening. If non-surgical treatment is elected, this could include long arm immobilization for 3 weeks followed by short arm immobilization for 3 weeks with a gradual return to play. If there is a chronic tear, the athlete can receive counsel that the risk of further damage is minimal. Therefore, the athlete can choose to try to play through the injury until the season is over, or the athlete could elect surgery immediately.[7] Corticosteroid injections are also an option, especially in elite athletes who elect to delay surgical intervention in an attempt to finish the season.

Differential Diagnosis

• Hypothenar hammer syndrome: Differentiate because there may be discoloration, fingertip ulcers, or splinter hemorrhages on the fourth or fifth digits. Angiogram may be able to diagnose this condition.
• Ulnar carpal impingement: Differentiate because this is commonly a result of ulnar shortening due to surgical resection from a prior injury.
• Ulnar extensor or flexor muscle tendonitis: Movements that cause the muscle to fire will provoke the pain. Pain may radiate along the muscle belly depending on the degree of inflammation.
• DRUJ chondral lesions or osteoarthritis: Differentiate via radiographic evidence suggestive of a chondral lesion or osteoarthritis.
• Ulnar styloid impingement syndrome: Symptoms consistent with TFCC injury, but the TFCC is intact.

Staging

The Palmer Classification is used to categorize TFCC injuries. Class 1 is traumatic, and class 2 is degenerative. All type 2 lesions can potentially associate with positive ulnar variance. Each class is further subclassified:

• 1A: The central aspect of the triangular fibrocartilage disc is perforated. Since the radioulnar ligaments are intact, these are stable injuries.
• 1B: Injury of the ulnar attachment of the triangular fibrocartilage disc. This injury is noncommunicating on arthrography.
• 1C: Distal disruption of the TFCC. In this case, there is a detachment of the volar ulnotriquetral and ulnolunate ligaments from the carpal attachment.
• 1D: Injury to the radial attachment of the triangular fibrocartilage disc. These injuries are communicating on MR arthrography.
• 2A: Degenerative changes of the triangular fibrocartilage disc without evidence of perforation.
• 2B: Grade 2A with the additional presence of chondromalacia of the hyaline cartilage on the articular surface.
• 2C: Full-thickness perforation of the triangular fibrocartilage disc.
• 2D: Any of the features in 2A through 2C plus lunotriquetral ligament tear.
• 2E: Grade 2D with the additional presence of ulnocarpal arthritis.

Prognosis

The prognosis for TFCC injury is generally favorable. Arthroscopic repair and arthroscopic debridement have both been shown to be effective procedures when performed in conjunction with ulnar shortening osteotomy.[15] Surgical management also has a good prognosis in children as it has been found to have successful outcomes in pediatric and adolescent high-level athletes who desire to return to sport.[16] One study of 71 patients under age 45 with a central TFCC tear found a 70% satisfaction rate after arthroscopic debridement. They also found that degenerative tears and higher positive ulnar variance generally had poorer outcomes.[12]  Some poor prognostic factors include a negative DRUJ stress test, female gender, and longer symptom duration.[17] Long-term prognosis is best when patients adhere to postoperative instructions.

Complications

Complications are mostly related to surgical management. Postoperative complications include, but are not limited to, infections, hypertrophic scarring, tendon injury, nerve injury, reflex sympathetic dystrophy, and joint stiffness with a limited range of motion.

Postoperative and Rehabilitation Care

Recovery after surgery varies, but typically four to six weeks should be expected for arthroscopy and approximately three months for an open approach. Patients will undergo physical therapy after the procedure. The exact time to begin physical therapy and the length of physical therapy depends on the type of surgery performed and the surgeon’s preference.

If an osteotomy is performed to shorten the ulna, patients are immobilized for approximately 4 weeks before they begin range of motion exercises. One way to determine when to start strength exercises is by grip strength. Estimations are that grip strength is 10% higher in the dominant hand. When grip strength is 80% of the expected normal, the athlete can begin strengthening exercises and gradually return to play. If the surgery is performed on the throwing arm, an elite athlete may be able to return to play in 8 to 12 weeks. If the surgical intervention is on the non-throwing arm, return to play in 6 to 8 weeks is possible.[18]

Deterrence and Patient Education

Patients should be educated to avoid activities that reproduce pain as soon as they initially notice the pain. If rest and strengthening exercises initiate in a timely fashion, it increases the odds of avoiding disease progression.  

Pearls and Other Issues

The pitfalls related to the diagnosis of TFCC injury largely relate to MRI misread. Some examples of common mistakes when reading MRI include:

• The prestyloid recess is a normal structure in the wrist near the ulnar styloid filled with fluid and can frequently be mistaken as an indication of injury or mass.[3]
• Cartilaginous tissue at the ulnar styloid can have a signal intensity that can be misread as a partial tear.[3]
• The ligamentum subcruentum is a normal structure at the ulnar insertion of the triangular fibrocartilage disc that often has high signal intensity.[3]
• Similarly, the radial attachment of the triangular fibrocartilage disc is a normal structure that appears with high signal intensity on MRI. Neither of these should be confused as an injury.[3]
• Another complication regarding reading MRI includes if there is wrist rotation during the timing of the imaging. If this is the case, the central disk can appear thin in the coronal plane. As long as there is no significant signal in addition to the thin-appearing disk, this is non-pathologic.[19]
• An intermediate signal in the central disk may represent intrinsic degeneration instead of a tear. Chondrocalcinosis can also appear similar to Palmer Class 2 lesions. If this is suspected, CT imaging prior to making the diagnosis of TFCC tear is in order.[19]

Enhancing Healthcare Team Outcomes

The best outcomes with TFCC injuries will occur when other etiologies of ulnar-sided wrist pain are ruled out with prompt initiation of conservative treatment. If the patient does not improve under conservative management, the next step is a surgical consultation obtained in a timely fashion. If an MRI is obtained, it is essential to have the MRI read by a radiologist who has experience with TFCC injuries. An interprofessional team of a nurse, physical or occupational therapist, and physician will provide the best follow-up care. [Level 5]