Editorial Commentary: In Cases of Concurrent Triangular Fibrocartilage Complex Tears and Ulnar Styloid Process Fracture Nonunions,We May Neither Need to Excise nor Repair the Ulnar Styloid Fracture Nonunion Fragment

The ulnar-sided wrist contains multiple potential pain generators that may present in isolation. Occasionally, however, wrist trauma results in multiple concurrent and overlapping injuries that make diagnosis and treatment of these conditions challenging. Deep/foveal tears of the triangular fibrocartilage complex (TFCC) may occur in the setting of nonunited ulnar styloid process fractures. Treatment of these injuries has historically included open TFCC repair with fixation or excision of the ulnar styloid fracture nonunion fragment; however, recent literature suggests that addressing the ulnar styloid nonunion fragment may not be as important as we think. Recent research shows that we may not need to excise or repair the ulnar styloid fracture nonunion fragment, which in turn may help preserve the complex ligamentous architecture that stabilizes the ulnar-sided wrist. One thing we know for sure is that foveal tears of the deep fibers of the TFCC, with or without ulnar styloid fracture (Palmer 1B, Atzei class 2 or 3), can produce distal radioulnar joint (DRUJ) instability and wrist dysfunction and should be addressed sooner rather than later to prevent long-term consequences, including DRUJ osteoarthritis. Whether you choose to approach the problem arthroscopically or open, the foveal TFCC tear should be repaired to prevent long-term sequalae.     

Repair of foveal detachment of the triangular fibrocartilage complex: open and arthroscopic transosseous techniques

Because the radioulnar ligament attaches to the ulnar fovea and base of the ulnar styloid, foveal detachment of the triangular fibrocartilage complex (TFCC) induces severe distal radioulnar joint instability. This article describes both an arthroscopic and open repair technique to reattach the TFCC to the fovea. Both techniques reanchor the detached TFCC to the fovea. Both techniques are reliable and promising techniques in the repair of a foveal detachment of the TFCC.     

Do triangular fibrocartilage complex foveal injuries affect the clinical outcome of ulnar shortening osteotomy for ulnar impaction syndrome?

BackgroundUlnar shortening osteotomy (USO), as its name implies, is used to shorten the ulna. It subsequently tightens the triangular fibrocartilage complex (TFCC) and ulnar wrist. TFCC foveal insertion is a primary stabilizer of the distal radioulnar joint. It is unclear whether USO is effective in TFCC foveal injuries. The purpose of this study was to review the clinical outcomes of ulnar shortening osteotomies with and without TFCC foveal injuries.MethodsWe retrospectively reviewed patients with ulnar wrist pain treated with USO and wrist arthroscopy including the distal radioulnar joint (DRUJ). Sixty-five patients were included in this study. An algorithm was used to guide surgical decision-making. After arthroscopic confirmation of ulnar impaction syndrome, we performed USO with a locking compression plate (mean length of shortening, 2.7 mm; range, 1–7.5 mm). The flattened TFCC disc due to ulnar shortening was confirmed arthroscopically. If the DRUJ was unstable after USO, we repaired the TFCC foveal insertion.ResultsThere were 32 post-traumatic and 33 idiopathic cases. We detected TFCC disc injuries in 34 wrists and TFCC foveal injuries in 33 wrists; both types were found in 15 wrists. TFCC foveal injuries were not significantly correlated with patient age, history of trauma, or clinical outcome. Most patients showed good clinical outcomes; 31 of 65 patients had preoperative DRUJ instability, with a significant number having foveal but not disc injuries.ConclusionUSO achieved reasonable outcomes, even in patients with TFCC foveal injuries. In cases demonstrating ulnar impaction, USO should be prioritized over TFCC repair.     

Relative contributions of the ulnar attachments of the triangular fibrocartilage complex to the dynamic stability of the distal radioulnar joint

PURPOSE: Laboratory studies evaluating the importance of the stabilizing structures of the distal radioulnar joint (DRUJ) largely have been limited to static design. Clinically, dynamic loading seems to be an important component of DRUJ instability. This study was designed to evaluate the influence of dynamic loading on the stability of the DRUJ with foveal versus styloid triangular fibrocartilage complex (TFCC) disruptions in a laboratory setting. METHODS: Twelve fresh-frozen cadaveric upper-extremity specimens were tested using a dynamic simulator to study the contributions of the 2 ulnar insertions of the TFCC to the dynamic stability of the DRUJ. The specimens were tested in 3 loading conditions (no load, agonist loading, antagonist loading) in 3 different states of the TFCC (intact, foveal disruption, styloid disruption). RESULTS: Without load no significant differences were found for the different conditions of the TFCC. Under loaded conditions the foveal insertion had a greater effect on stability than did the styloid insertion. Under agonist loading significant differences were found during supinating and pronating motions. With antagonist loading a significant difference was found only during supination. CONCLUSIONS: The study results support the clinical impression that dynamic loading is an important component of DRUJ instability and that disruption of the foveal TFCC insertion into the foveal region of the distal ulna can produce instability.     

Open repair of the ulnar disruption of the triangular fibrocartilage complex with double three-dimensional mattress suturing technique

Open repair technique of the ulnar disruption of the triangular fibrocartilage complex is described. This technique is indicated for a fresh or a relatively fresh (less than 1 year after the initial injury) ulnar foveal detachment tear, horizontal tear, and proximal slit tear of the triangular fibrocartilage complex, all of which are accompanied by severe dorsal, palmar, or multidirectional instability of the distal radioulnar joint. A chronic tear greater than 1 year from initial injury and a fresh triangular fibrocartilage complex tear without distal radioulnar joint instability, such as central slit tear, are excluded from our indications. A dorsal C-shaped skin incision, a longitudinal incision of the radial edge of the extensor carpi ulnaris subsheath and the dorsal distal radioulnar joint capsule, exposes the distal radioulnar joint. A small, 5-mm longitudinal incision at the origin of the radioulnar ligament exposes its fovea detachment and/or the proximal slit tear of the triangular fibrocartilage complex. The disrupted radioulnar ligament is sutured in a pullout fashion to the ulna with a 3-dimensional double mattress technique through 2 bone tunnels that is precisely made at the central portion of the fovea with 1.2-mm K-wire. An additional horizontal mattress suture is used for closure of the small incision made at the radioulnar ligament, then the extensor carpi ulnaris is repaired. This open-repair technique is complex and requires precise technical skills; however, early results have been more rewarding than the conservative treatment.     

Distal Radioulnar Joint Instability: Assessment of Three Intraoperative Radiographic Stress Tests

Background: The purpose of this study is to describe three radiographic stress tests that could be used to examine for distal radioulnar joint (DRUJ) instability intraoperatively, and to determine their ability to detect DRUJ instability after sequentially sectioning the DRUJ. Methods: Eleven fresh frozen cadaveric upper extremities (mean age 52.6 ± 14.9 years) were obtained. We sequentially sectioned the DRUJ. After each component of the DRUJ was sectioned, we performed three radiographic stress tests—squeeze test, ulnar pull in coronal plane, and simulated DRUJ ballotment test. Results: The squeeze test detected a significant increase in diastasis relative to the intact DRUJ after sectioning of the foveal insertion of the triangular fibrocartilage complex (TFCC; 1.0 mm) and the distal oblique bundle (DOB; 1.2 mm). The ulnar pull test in the coronal plane detected a significant increase in diastasis relative to the intact DRUJ after sectioning of the dorsal and volar radioulnar ligaments (2 mm), the foveal insertion of the TFCC (2.6 mm), and the DOB (4.4 mm). The simulated DRUJ ballotment test detected a significant increase in dorsal translation of the ulna relative to the intact DRUJ with sectioning of the foveal insertion of the TFCC (4.9 mm) and the DOB (5.6 mm). Conclusion: The squeeze test and simulated DRUJ ballotment test detect a significant increase in diastasis after the foveal attachment of the TFCC was sectioned. The ulnar pull test in the coronal plane was the most sensitive test for detecting a significant increase in diastasis relative to the intact DRUJ.     

Editorial Commentary: Guidelines for Wrist Triangular Fibrocartilage Complex Foveal Tears: A Compass for a Broad Voyage

The ulnar head attachment of triangular fibrocartilage complex is divided into 2 sections: the distal radioulnar ligament consists of superficial and deep bundles on both the palmar and dorsal sides, which attach at the fovea and the base of the ulnar styloid. A tear on the ulnar side of triangular fibrocartilage complex inevitably occurs at these attachments. Both magnetic resonance imaging and distal radioulnar joint (DRUJ) arthroscopy are crucial. DRUJ arthroscopy can clarify the tear location. An ulnar styloid tear can be treated by capsular repair. However, a foveal tear should be reattached to the fovea because this tear could cause gross DRUJ instability. There are several ways to reattach the bundles to the fovea, including single- or double-tunnel or bone anchors, and open versus arthroscopic.     

Editorial Commentary: The Hook Test Is More Accurate for Detecting Foveal Triangular Fibrocartilage Complex Tears but Not More Important Than the Trampoline Test

Wrist arthroscopy is a successful tool to diagnose and treat several intra-articular wrist pathologies. To assess the stability and integrity of the triangular fibrocartilage complex (TFCC), the most commonly injured structure in the ulnocarpal compartment, the trampoline and hook tests are frequently used in daily practice. However, their arthroscopic performance measures have not been well elucidated to date. While the hook test may primarily be seen as a sensitive tool to detect foveal TFCC tears, the trampoline test is of equal importance for the clinician because it can detect frequently occurring superficial (distal) tears in the peripheral TFCC area. As opposed to the hook test, however, the trampoline test might more easily lead to interrater disagreement since the rebound after probing is rather a continuum than a binary measure and might be related to a different severity of peripheral TFCC disruption. The combination of both tests should thus be pursued since they complement each other very well. Proper interpretation of the tests needs sufficient experience and should be done in concordance with the clinical evaluation (ie, fovea sign, distal radioulnar joint ballottement test). Hence, the hook test may be more accurate to detect foveal TFCC tears but all together not more important than the trampoline test to establish the correct diagnosis. For once, Captain Hook has won!     

Foveal TFCC tear classification and treatment

During the last two decades, increased knowledge of functional anatomy and pathophysiology of the triangular fibrocartilage complex (TFCC) have contributed to a change in surgeons' perspective toward it. The earlier concept of the TFCC as the "hammock" structure of the ulnar carpus has updated to the "iceberg" concept, whereby the much larger "submerged" part represents the foveal insertions of the TFCC and functions as the stabilizer of the distal radioulnar joint and the ulnar carpus, thus lending it greater functional importance. This article presents an algorithm of the treatment of traumatic peripheral TFCC tear based on clinical, radiological, and arthroscopic findings.     

Pathomechanisms of ulnar ligament lesions of the wrist in a cadaveric distal radius fracture model

Background and purpose

Mechanisms of injury to ulnar-sided ligaments (stabilizing the distal radioulnar joint and the ulna to the carpus) associated with dorsally displaced distal radius fractures are poorly described. We investigated the injury patterns in a human cadaver fracture model.

Methods

Fresh frozen human cadaver arms were used. A dorsal open-wedge osteotomy was performed in the distal radius. In 8 specimens, pressure was applied to the palm with the wrist in dorsiflexion and ulnar-sided stabilizing structures subsequently severed. Dorsal angulation was measured on digitized radiographs. In 8 other specimens, the triangular fibrocartilage complex (TFCC) was forced into rupture by axially loading the forearm with the wrist in dorsiflexion. The ulnar side was dissected and injuries were recorded.

Results

Intact ulnar soft tissues limited the dorsal angulation of the distal radius fragment to a median of 32^o (16–34). A combination of bending and shearing of the distal radius fragment was needed to create TFCC injuries. Both palmar and dorsal injuries were observed simultaneously in 6 of 8 specimens.

Interpretation

A TFCC injury can be expected when dorsal angulation of a distal radius fracture exceeds 32^o. The extensor carpi ulnaris subsheath may be a functionally integral part of the TFCC. Both dorsal and palmar structures can tear simultaneously. These findings may have implications for reconstruction of ulnar sided soft tissue injuries.A complex of ligaments on the ulnar side of the wrist supports the stability of the ulnocarpal and the distal radioulnar (DRU) joints. Included in this are the extensor carpi ulnaris (ECU) subsheath and the triangular fibrocartilage complex (TFCC), which is further subdivided into the radioulnar ligaments (RULs), the ulnotriquetral ligament (UT), and the ulnolunate (UL) ligament (Garcia-Elias 1998, Berger 2001). Injuries to the TFCC are common in dorsally angulated fractures of the distal radius fracture (Colle''s fracture) and may adversely affect functional outcome (Lindau et al. 2000). The pathomechanics of these injuries are poorly studied, however.During wrist arthroscopy, we have observed two lesions that are often present when treating TFCC lesions associated with distal radius fractures: (1) a separation of the floor of the ECU tendon sheath from the TFCC, and (2) an injury to the foveal insertion of the TFCC into the ulna. It seems probable that there must be a limit to how much the distal radius fragment can be displaced without rupture of the TFCC or fracture of the ulna.We investigated the characteristics of a TFCC injury in a cadaveric fracture model of dorsally displaced fractures. We hypothesized that (1) a TFCC lesion can be expected at a certain degree of displacement and that (2) a rupture of the foveal insertion would begin in the palmar capsule and progress dorsally, due to the dorsal displacement of the distal radius fragment.     

Arthroscopic evaluation of the foveal attachment of the triangular fibrocartilage

Anatomical and biomechanical studies have highlighted the importance of the deep attachment of the TFCC for maintaining stability of the distal radioulnar joint (DRUJ). The standard arthroscopic assessment of the TFCC does not allow one to definitively determine whether the deep fibers are indeed intact, and establishing the diagnosis of a foveal detachment remains an exacting challenge. DRUJ arthroscopy is useful to assess the foveal fibers in any patient with DRUJ instability and can aid in the surgical decision making.     

Longitudinal split tears of the ulnotriquetral ligament

Unlike tears of the peripheral triangular fibrocartilage or avulsions of the distal radioulnar ligaments, longitudinal split tears of the ulnotriquetral (UT) ligament do not cause any instability to the distal radioulnar joint or the ulnocarpal articulation. It is mainly a pain syndrome that can be incapacitating. However, because the UT ligament arises from the palmar radioulnar ligament of the triangular fibrocartilage complex (TFCC), it is by definition, an injury of the TFCC. The purpose of this article is to describe the cause of chronic ulnar wrist pain arising from a longitudinal split tear of the UT ligament.     

Effects of peripheral tears of the triangular fibrocartilage complex on distal radioulnar joint stability: A biomechanical study

BackgroundPeripheral triangular fibrocartilage complex (TFCC) tears may induce instability of the distal radioulnar joint (DRUJ). In this biomechanical study, simulated peripheral tears of the TFCC were examined on the stability of the DRUJ. Restabilization effect of the DRUJ by ulnar shortening and direct repair of those injuries were sequentially examined.MethodThe DRUJ stiffness was measured in intact, simulated two types of peripheral tears (ulnar and extended ulnodorsal) at three forearm positions: neutral, 60° pronation and 60° supination in 8 fresh frozen cadaver specimens. After the tears were sutured with stitches or after simulated ulnar shortening of 3 mm, the DRUJ stiffness was again measured.ResultsThe ulnar and ulnodorsal TFCC tears decreased the DRUJ stiffness significantly compared with the intact in all forearm positions. When ulnar shortening was done for the ulnar tear, the DRUJ stiffness increased significantly in the neutral and 60° pronated positions. When the ulnar TFCC tear was repaired, the DRUJ stiffness increased significantly in all forearm positions. DRUJ stiffness did not increase either with ulnar shortening or repair in ulnodorsal tear of the TFCC, however.ConclusionThe simulated TFCC tears indicated significant loss of DRUJ stiffness. Direct repair or ulnar shortening was effective only on treatment of the ulnar tear of the TFCC in this study.     

Traumatic disruption of the triangular fibrocartilage complex. Pathoanatomy.

The surgical pathology in 42 cases of traumatic triangular fibrocartilage complex (TFCC) disruption comprised a spectrum of injury resulting in five basic stages of increasingly severe ulnar wrist instability. In all cases, detachment of the articular disk from its ulnar insertion was the principal cause of distal radioulnar joint instability; in 28 (67%), concomitant injury to the adjacent extensor carpi ulnaris sheath, the ulnocarpal ligaments, or the peritriquetral ligaments compounded the instability. Thus, rather than an isolated event, peripheral disruption of the disk often proved the major constituent of multicomponent lesions--lesions consistently suitable for repair. In this series of destabilizing TFCC disruption requiring operative treatment, awareness that some injuries selectively affect the articular disk, whereas others compromise wider zones of wrist anatomy, was essential to successful surgery.     

Anatomy and biomechanics of the interosseous membrane: its importance in the longitudinal stability of the forearm

The interosseous membrane (IOM) links the ulna and the radius and acts as an extrinsic ligament, assisting the proximal radioulnar joint (PRUJ) and distal radioulnar joint (DRUJ) ligaments. It checks dissociating forces, transmits forces from one forearm bone to the other, and coordinates loading forces. The anterior plane of descending fibers from the radius checks the proximal displacement of this bone. Intermediate descending fibers are the strongest. The posterior plane, with ascending fibers from the radius, checks its proximal displacement. An early repair of a torn IOM is feasible and should be performed. This can be associated with an augmentation procedure.     

Editorial Commentary: Triangular Fibrocartilage Complex “Fovea”—An Attractive and Complicated Structure—Is “The Anchor” Not Only for Distal Radioulnar Joint but Also for Wrist Surgeons

A triangular fibrocartilage complex foveal lesion is one of the key structures for stabilizing the distal radioulnar joint. Its anatomy is unique and healing potential is still controversial. If surgical repair is necessary, ulnar abutment is contraindicated, evaluation of the ligament condition using distal radioulnar joint arthroscopy is crucial to achieve satisfactory results.     

Reconstructive procedure for unstable radial-sided triangular fibrocartilage complex avulsions

PURPOSE: Radial-sided avulsions of the triangular fibrocartilage complex (TFCC) (Palmer 1D) with distal radioulnar joint (DRUJ) instability remain a challenging pathology to treat. We tested an intra-articular reconstruction that addresses unstable radial-sided TFCC avulsions. METHODS: Ten preserved, dissected, cadaveric forearm specimens with intact TFCC and without ulnar-positive variance had biomechanical testing using a hydraulic testing device. The measurement of total displacement of the ulna relative to the radius was performed with an applied load ranging from 20 N in a volar direction to 20 N in a dorsal direction. Specimens were tested sequentially with intact TFCC, with surgically induced Palmer 1D lesions, and after reconstruction of the TFCC. All tests were performed at neutral, maximal pronation, and maximal supination. RESULTS: The mean total displacements of the DRUJ of the specimens at neutral rotation were as follows: 4.1 +/- 0.4 mm for the intact specimens compared with 11.8 +/- 0.8 mm after creation of the tear and 3.9 +/- 0.7 mm for the reconstructed specimens. In maximal pronation the mean total displacements were as follows: 2.4 +/- 0.3 mm intact versus 4.9 +/- 0.7 mm for torn and 2.1 +/- 0.3 mm after reconstruction. In maximal supination the mean total displacements were as follows: 1.4 +/- 0.2 mm intact versus 5.7 +/- 1.3 mm for torn and 1.0 +/- 0.1 mm after reconstruction. All specimens obtained the preoperative pronation and supination motion after the reconstruction. CONCLUSIONS: Current procedures are unable to restore DRUJ stability without a significant limitation of pronation and supination. This intra-articular reconstruction of radial-sided TFCC avulsions succeeded in restoring baseline stability to the DRUJ without interfering with pronation/supination.     

Arthrographic surface anatomy of the carpal triangular fibrocartilage complex

In a review of 364 radiocarpal and 123 distal radioulnar joint arthrograms we identified 44 (12%) patients with contrast defects at either the proximal or distal surface of the carpal triangular fibrocartilage complex (TFCC). Differences in their arthrographic characteristics distinguished two separate groups of patients; one with similar and another with dissimilar appearing TFCC surface contrast collections. Thirty-one of our 44 patients had similar appearing, isolated radial-sided collections at either the proximal or distal TFCC surfaces. Our arthrographic, demographic, and historical study of these patients suggests that the collections are not caused by traumatic partial TFCC tears but represent a normal anatomic variant, probably a synovial recess at the radial TFCC attachment. Arthrography and dissection of a limited number of cadaveric specimens confirmed this conclusion. The second group included the remaining 13 patients. This group had contrast collections at either the proximal or distal TFCC surface, which varied in location and appearance. This smaller group is more likely to represent those uncommon patients with partial TFCC defects caused by tears.     

Radioulnar laxity and clinical outcome do not correlate after a distal radius fracture

Injury to the triangular fibrocartilage complex associated with distal radius fracture may cause symptoms of ulnar instability. Assessed by a radioulnar stress test, increased laxity of the distal radioulnar joint has in two previous studies been depicted to be associated with poorer outcome. This prospective study of 40 adults investigates the correlation of this test with functional outcome as measured by DASH. No clinically significant difference was found in relation to this test at two and five years after injury. Therefore using this test alone to decide whether or not to perform an acute repair of the TFCC cannot be recommended.     

Arthroscopic treatment for ulnar-sided TFCC-tears

Objective

Ruptures of ulnar-sided triangular fibrocartilaginous complex (TFCC) often occur in cases of trauma. Golden standard for diagnosis is the arthroscopy of the wrist. TFCC lesions are classified according to their location if traumatic in origin or if degenerative according to their severity.

Materials and methods

Recent literature has focused on the ruptures of ulnar-sided triangular fibrocartilaginous complex. This article describes conservative, operative and arthroscopic surgical techniques to reconstruct the triangular fibrocartilaginous complex and restore distal radioulnar joint stability.

Results

The main therapeutic goal should be the stabilization of the DRUJ by reattachment of the torn ligaments in ulnar-sided ruptures to the deep fibers in the fovea. This reinsertion can be performed by transosseous suture, a suture anchor or open.

Conclusion

Central TFCC tears are typically located close to the sigmoid notch of the radius and are either traumatic or degenerative in origin. While central TFCC lesions are usually treated by arthroscopic debridement using small joint punches or a bipolar high frequency system, the ulnar TFCC avulsions can also be refixed arthroscopically in different techniques.