Origins and insertions of the triangular fibrocartilage complex: a histological study

The origins and insertions of the triangular fibrocartilage complex (TFCC) were examined histologically in serially sectioned fresh-frozen cadaver wrists. The radioulnar ligament arose vertically through Sharpey's fibres from a broad area in the ulnar fovea and more horizontally from a narrow area at the base of the ulnar styloid. The floor of the extensor carpi ulnaris sheath also originated firmly from the dorsal side of the fovea of the ulna, through an arrangement of Sharpey's fibres. Loose ulnocarpally oriented fibres, corresponding to a thickened ulnar joint capsule, arose from the hyaline-like cartilage matrix at the tip of the ulnar styloid and inserted onto the triquetrum without Sharpey's fibres. The ulnolunate and ulnotriquetral ligaments originated not from the ulna, but from the palmar side of the TFCC. The insertion of the TFCC into the sigmoid notch of the radius demonstrated a central transition from the fibrocartilaginous disc into hyaline cartilage and a firmer fibroosseous transition of the dorsal and palmar portions of the radioulnar ligament at the periphery.     

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.     

腕关节镜下治疗尺骨茎突骨折

目的 探讨腕关节镜监视下治疗尺骨茎突骨折的方法,以获得更好的治疗效果.方法 对15例尺骨茎突骨折的患者,在C臂透视机及腕关节镜监视下先将合并的桡骨远端骨折进行复位,经皮穿针内固定或切开复位钢板内固定,然后在腕关节镜下检查三角纤维软骨复合体(triangular fibrocartilage complex,TFCC)是否损伤,并作修整、清理等相应的处理,在关节镜监视下将尺骨茎突骨折复位,经皮作钢丝张力带内固定.结果 11例合并有TFCC损伤,经平均15.4个月的临床随访,X线片检查显示尺骨茎突骨折全部骨性愈合,骨性愈合时间平均5.2个月.按照Green-O'Brien功能评定方法进行腕关节功能评定,优良率为93.3%,无腕关节尺侧疼痛及腕关节不稳等并发症发生.结论 腕关节镜下治疗尺骨茎突骨折既可以对骨折进行有效的复位及固定,有利于骨折的愈合;又可以了解腕关节内TFCC等结构的损伤程度,便于早期处理,以免遗留慢性腕痛或腕关节不稳定.     

Editorial Commentary: Arthroscopic Capsular Repair of Wrist Triangular Fibrocartilage Complex Tears: Beware That Apparent Isolated Atzei Class 1 (Isolated Distal Component) Tears May Include a Proximal Component

Accumulating knowledge about the anatomy of the triangular fibrocartilage complex (TFCC) and its function has revealed that the foveal insertion of the TFCC plays a key role in distal radioulnar joint stability rather than the superficial fibers that insert into the ulnar styloid. Recently, the interest in torn peripheral TFCC repair has been shifting from capsular repair for Atzei class 1 to foveal repair for Atzei class 2 or 3. Most acute Atzei class 1 tears spontaneously heal without surgical repair; in contrast, in cases of sustained pain and distal radioulnar joint instability even after successful Atzei class 1 repair, the unrecognized proximal component TFCC tear concomitant with a distal component TFCC tear may exist and appropriate treatment for the proximal component TFCC tear should be combined. Although overall successful results have been reported using various repair techniques, the most important consideration is re-establishing biologic regeneration potential at the insertion site of torn TFCC.     

Peripheral Triangular Fibrocartilage Complex Tears Cause Ulnocarpal Instability: A Biomechanical Pilot Study

Background  

Instability at the ulnocarpal joint has many causes, but the common thread among these causes is the presence of abnormalities in the triangular fibrocartilage complex (TFCC). However, the biomechanical consequences at the ulnocarpal joint after detachment of the TFCC from the ulnar styloid are not clearly defined. Better delineation of whether peripheral TFCC detachments cause ulnocarpal instability will help to design surgical treatments.     

Ulnar styloid triquetral impaction.

BACKGROUND: Ulnar styloid triquetral impaction (USTI), one of many causes of ulnar sided wrist pain, is a pathological entity with clear clinical and radiographic features, distinct and different from the impaction of the ulnar head against the lunate or ulno-carpal impaction (UCI). Pain is ulnar and point-tenderness is present precisely over the ulnar styloid as opposed to the proximal lunate in UCI. The provocative maneouvre of dorsiflexion in pronation followed by supination is markedly different from the ulnar deviation grind test maneouvres used to diagnose UCI. Multiple anatomical and pathological features interplay to produce a situation in which the distance between the tip of the ulnar styloid and the triquetrum is reduced resulting in USTI. The concept of ulnar styloid variance is introduced and anatomical variations of ulnar styloid length are demonstrated. METHODS: The clinical and radiographic features of 56 patients diagnosed with USTI were analysed. One thousand standardised film-file wrist radiographs were measured to determine the average length of the ulnar styloid in the population as well as the average projection of the styloid above the radius (ulnar styloid variance). RESULTS: An aetiological classification system for USTI was developed based on the clinical and radiographic features of the aforementioned patients and radiographs. CONCLUSIONS: The causes of this syndrome are often complex and classification of the aetiological features is clinically useful. It is important for physicians and surgeons to recognise the clinical and radiographic features of this syndrome in order to properly manage the symptoms and prevent an iatrogenic production of USTI.     

尺骨茎突骨折对桡骨远端骨折手术疗效及腕关节功能的影响

目的观察尺骨茎突骨折对桡骨远端骨折手术疗效及腕关节功能的影响。方法对64例不稳定桡骨远端骨折进行回顾性分析,选择AO分型为A型和B型的不稳定桡骨远端骨折患者,均行切开复位T型桡骨远端锁定钢板内固定治疗,尺骨茎突骨折未作特殊处理,将所有资料按照未合并尺骨茎突骨折组、尺骨茎突骨折(体部骨折)Ⅰ型组及尺骨茎突骨折(基底部骨折)Ⅱ型组分组进行整理分析,记录病例AO分型及术前、术后6个月和术后1年的X线片测量结果 ,按照Bunger提出的解剖学评分(掌倾角、尺偏角、桡骨茎突高度)进行解剖学评估,同时进行GartlandWerly评分。结果随访时间为7~12个月,平均11个月,64例桡骨远端骨折均愈合。未合并尺骨茎突骨折组、尺骨茎突骨折Ⅰ型组及Ⅱ型组术前、术后6个月及术后1年解剖学评分差异无统计学意义,未合并尺骨茎突骨折组与尺骨茎突骨折Ⅰ型组Gartlant-Werley评分、优良率差异无统计学意义。但未合并尺骨茎突骨折组与尺骨茎突骨折Ⅱ型Gartlant-Werley评分、优良率差异有统计学意义,尺骨茎突骨折Ⅰ型组与Ⅱ型组相比,Gartlant-Werley评分、优良率差异有统计学意义。结论尺骨茎突骨折与否及分型对桡骨远端骨折术后解剖学评分无影响,尺骨茎突体部骨折对腕关节功能无影响,但尺骨茎突基底部骨折对腕关节功能有一定影响,值得进一步研究。     

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.     

Ulnar styloid fracture in children: a retrospective study of 46 cases

Ulnar styloid fractures are frequently ignored in the treatment of wrist fractures in children. Forty-six untreated ulnar styloid fractures (40 tip and six base fractures) associated with radial injuries (45 patients) were retrospectively analysed. At the removal of the cast, we recorded that 80% had a nonunion of the styloid fracture. Thirty-five patients were reviewed at an average of 19 months after treatment. Thirty tip fractures and five base avulsions were found. We recorded 28 patients with a good clinical result despite 21 cases of nonunion, whereas seven patients (all nonunions) had a fair result. All the fair results suffered from intermittent pain during sports and movement, radioulnar joint instability and tears of the triangular fibrocartilage complex. It can be concluded that both distal radius and ulnar styloid fractures should be taken into account in the initial treatment and pain associated with a nonunion of the ulnar styloid in a child may be due to a tear of the triangular fibrocartilage complex.     

Dynamic changes in the shape of the triangular fibrocartilage complex during rotation demonstrated with high resolution magnetic resonance imaging.

We studied in vivo dynamic changes in the triangular fibrocartilage complex (TFCC) in ten healthy volunteers using high-resolution magnetic resonance imaging (MRI). A custom made surface coil, which was specially designed to allow movements of the wrist in all directions, was used in this study. MR images in the axial and coronal planes were acquired at maximum pronation, in the neutral position and at maximum supination. During pronation and supination, little deformity of the disc proper was seen on axial sections. In contrast, the ulnar side of the TFCC around the ulnar styloid process showed obvious dynamic changes. The ulnar head translated palmarly to the radius in supination and dorsally in pronation, while there was little change in the position of the fovea of the ulna in relation to the radius. Considering the three-dimensional structure of the TFCC, these findings suggest that the disc proper is strong enough to support the ulnar carpus with little deformity during rotation and that the triangular ligament twists at its origin. During rotation there is friction between the proximal side of the disc proper and the ulnar head. On coronal sections, the disc proper became thinner in pronation due to increased ulnar variance.     

Anatomic and biomechanical analysis of the arthroscopic wafer procedure.

The ulnar impaction syndrome is a common clinical entity that is most often associated with positive ulnar variance and is characterized by triangular fibrocartilage complex (TFCC), lunate, and/or distal ulnar pathology. Traditional treatment for symptomatic ulnar impaction syndrome has been conservative; however, in cases refractory to nonoperative management, formal ulnar shortening has been successful in long-term clinical series. Recently, arthroscopic ulnar shortening, the "arthroscopic wafer procedure" (AWP) (debridement of the perforated TFCC margins and limited ulnar head resection using a motorized burr) has become an option to treat this clinical syndrome. In an attempt to evaluate the biomechanical efficacy of the AWP, an experimental study was undertaken using nine ulnar positive cadaver forearms. Each specimen was evaluated biomechanically using axial load cells and pressure-sensitive film to evaluate the effect of serial resection of the TFCC and distal ulna on axial load and ulnar carpal pressures. The results of this experimental study revealed a statistically significant unloading of the ulnar aspect of the wrist after excision of the centrum of the TFCC and resection of the radial two-thirds width of the ulnar head, to a depth of subchondral bone resection. Furthermore, additional bony resection tended to correlate favorably with the stage of TFCC pathology noted, i.e., the more advanced the stage, the more resection necessary to unload the ulnar aspect of the wrist. Based on this biomechanical study, a limited clinical series has been initiated with early favorable results. The AWP biomechanically unloads the ulnar carpal complex, and therefore has a theoretical potential of relieving the symptoms of the ulnar impaction syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)     

Should ulnar styloid be fixed following fixation of a distal radius fracture?,

IntroductionFracture of the base of the ulnar styloid has shown to have higher incidence of TFCC tears and DRUJ instability leading to nonunion and impaired function. Poorer functional outcomes of the distal radius fracture have been attributed to the untreated associated ulnar styloid fractures while some studies have shown no difference. Thus, the treatment remains controversial. However, it has been shown that fractures at the base of the ulnar styloid have a higher incidence of tears in the triangular fibrocartilage complex (TFCC) and instability in the distal radioulnar joint (DRUJ), which can lead to nonunion and impaired function. Despite this, there are currently no studies comparing the outcomes of surgically and conservatively treated patients.MethodsA retrospective study was conducted to analyze the outcomes of intra-articular distal radius fractures associated with base of ulnar fracture treated with distal radius LCP fixation. The study included 14 patients who were treated surgically and 49 patients who were treated conservatively, with a minimum follow-up of 2 years. Radiological parameters such as union and amount of displacement, VAS score for ulnar-sided wrist pain, functional assessment using the modified Mayo score and the quick DASH questionnaire and complications were analyzed.ResultsAt the final follow-up, the mean scores for pain (VAS), functional outcomes (modified Mayo score), disability (QuickDASH score), range of motion, and non-union rate were found to be statistically insignificant (p > 0.05) between the surgically treated and conservatively treated groups. However, patients with non-union had statistically significant higher scores for pain (VAS), greater post-operative displacement of the styloid, poorer functional outcomes, and higher disability (p < 0.05).ConclusionWhile there was no significant difference in ulnar-sided wrist pain and functional outcomes between the surgically treated and conservatively treated groups, the conservatively treated cases had a higher risk of non-union, which can negatively impact functional outcomes. The amount of pre-operative displacement was found to be a key factor in predicting non-union and can be used as a guide for determining the management of this type of fracture.     

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.     

An anatomical study of the ligaments of the ulnar compartment of the wrist.

The ligamentous structures of the triangular fibrocartilage complex (TFCC) and their attachments were examined anatomically and histologically using fresh and embalmed cadavers. The TFCC was observed to have a three-dimensional structure consisting of three palmar ligaments--the short radiolunate (SRL), ulnolunate (UL), and ulnotriquetral (UT) ligaments. In addition, the attachment site of the ulnocarpal ligament (UC), which had been previously unknown, was identified. The dorsal components of the TFCC have been previously reported to consist solely of the extensor carpi ulnaris (ECU) subsheath; however, the ligamentous components running from the ulnar styloid process to the triquetrum were found at a layer deeper than the floor of the ECU subsheath. The UC has been reported previously as a two-dimensional structure, but there has been some disagreement as to its attachment sites.(2-6,14,15) It is suggested that the dorsal UT ligament should be considered as a separate ligament, based on its different direction and distal attachment site as compared with those of the ulnar collateral ligament (UCL) and ECU subsheath.     

两种内固定治疗桡骨远端骨折伴尺骨茎突基底部骨折的疗效比较

目的 比较采用桡骨远端掌侧锁定钢板+尺骨茎突单皮质骨螺钉固定和单纯桡骨远端掌侧锁定钢板治疗桡骨远端骨折伴尺骨茎突基底部骨折的疗效.方法 将73例桡骨远端骨折伴尺骨茎突基底部骨折患者按治疗方法的不同分为观察组(采用桡骨远端掌侧锁定钢板+尺骨茎突单皮质骨螺钉固定治疗,38例)和对照组(采用单纯桡骨远端掌侧锁定钢板治疗,35...     

The carpal detachment injury of the triangular fibrocartilage complex

Triangular fibrocartilage complex (TFCC) injuries were suspected clinically in 22 wrists of 21 patients, but arthrography and MRI assessments of this structure were normal. As conservative therapy for 2 months did not improve their symptoms, wrist arthroscopy was then performed. Although no abnormalities of the TFCC and ligaments were observed, meniscus homologue-like tissue which arose from TFCC was riding on the articular surface of the triquetrum. After resection of this soft tissue with a shaver and a punch, the symptoms disappeared in all cases. The arthroscopic findings suggested that a portion of TFCC that was originally attached to the ulnar side of the triquetrum had become detached.     

三角纤维软骨复合体损伤后腕关节稳定性的生物力学分析

目的评估实验性创伤致三角纤维软骨复合体（triangular fibrocartilage complex，TFCC）损伤后腕关节稳定性的变化，为不同类型损伤选择不同的手术方法提供生物力学依据。方法取自愿捐赠新鲜成人上肢标本14个，其中2个标本用于测试实验装置和测量技术。使用1NSTRON 8874生物力学测试系统对标本进行扭转试验。根据Palmer关于创伤性TFCC损伤的分类，将12个标本随机分为4组（n=3），先切开背侧关节囊（arthrotomy，ART）检测，然后进行4类实验性创伤：1A类：TFCC中央部撕裂；1B类：TFCC从尺骨茎突止点上撕裂，伴或不伴尺骨茎突骨折；1C类：TFCC远端撕裂，伴尺月韧带和／或尺三角韧带损伤；1D类：TFCC从桡骨附着缘上撕脱，分别测试腕部从屈60&#176;到伸60&#176;（每变化30&#176;测量1次），被动内外旋（0～20&#176;）的扭矩值。将关节切开后测试的扭矩值与各实验组的扭矩值分别进行比较分析。结果1B类损伤仅切断TFCC在尺骨附着点（1B-1）的扭矩值为（0．709&#177;0．134）Nm，仅切开ART的扭矩值为（0．713&#177;0．121）Nm，二者比较差异无统计学意义（P〉0．05）；如合并尺骨茎突骨折（1B-2），扭矩值为（0．409&#177;0．113）Nm，与仅切开ART的扭矩值比较差异有统计学意义（P〈0．05）。1C类损伤在腕关节处于背伸和掌屈45。时扭矩值分别为（0．878&#177;0．184）、（0．988&#177;0.197）Nm，切开ART在背伸和掌屈30～60&#176;时测得的扭矩值分别为（1．510&#177;0．173）、（1，540&#177;0．093）Nm，比较差异有统计学意义（P〈0．05）。1A、1D类损伤和切开背侧关节囊测得的扭矩值比较差异无统计学意义（P〉0．05）。结论TFCC1B-2类损伤和1C类损伤对腕关节的稳定性有影响。     

累及桡尺远侧关节不稳定的尺骨茎突骨折手术治疗

目的 介绍累及桡尺远侧关节不稳定的桡骨远端合并尺骨茎突骨折的手术指征和治疗方法.方法 2005年1月至2009年6月,对12例桡骨远端骨折合并尺骨茎突骨折的患者,采用克氏针结合张力带钢丝固定尺骨茎突,同时采用骨锚修复下尺桡韧带深层结构在尺骨隐窝的止点,从而稳定桡尺远侧关节.结果 术后12例桡骨远端骨折及尺骨茎突骨折均愈合,术后随访时间为6～18个月.按改良的Mayo腕关节评分标准评定:优4例,良5例,中2例,差1例.结论 尺骨茎突在桡尺远侧关节稳定中起着重要作用,对累及下尺桡韧带结构损伤的尺骨茎突骨折进行固定并重建韧带对稳定桡尺远侧关节有较为重要的作用.     

Acute injuries of the distal radioulnar joint

Distal radioulnar joint injuries can occur in isolation or in association with distal radius fractures, Galeazzi fractures, Essex-Lopresti injuries, and both-bone forearm fractures. The authors have classified DRUJ/TFCC injuries into stable, partially unstable (subluxation), and unstable (dislocation) patterns based on the injured structures and clinical findings. Clinical findings and plain radiographs are usually sufficient to diagnose the lesion, but axial CT scans are pathognomonic. Diagnostic arthroscopy is the next test of choice to visualize stable and partially unstable lesions. Stable injuries of the DRUJ/TFCC unresponsive to conservative measures require arthroscopic debridement of the TFCC tear, along with ulnar shortening if there is ulnar-positive variance. Partially unstable injuries, on the other hand, are treated with direct arthroscopic or open repair of the TFCC tear, once again, along with ulnar shortening if ulnar-positive variance is present. Unstable injuries include simple and complex DRUJ dislocations. A simple DRUJ dislocation is easily reducible but may be stable or unstable. In complex dislocation, reduction is not possible because there is soft tissue interposition or a significant tear. After the associated injury is dealt with, treatment for complex injuries requires exploration of the DRUJ, extraction of the interposed tissue, repair of the soft tissues, and open reduction and internal fixation of the ulnar styloid fracture (if present and displaced). The early recognition and appropriate treatment of an acute DRUJ injury are critical to avoid progression to a chronic DRUJ disorder, the treatment of which is much more difficult and much less satisfying.