桡骨远端骨折对下尺桡关节稳定性的影响

目的:分析桡骨远端骨折后腕部功能与下尺桡关节稳定性之间的关系,探讨桡骨远端骨折影响下尺桡关节稳定性的原因。方法:85例桡骨远端骨折患者,男27例,女58例;年龄17~74岁,平均42.3岁。采用手法复位石膏外固定治疗,伤后6~9个月(平均6.7个月)摄腕关节正侧位X线CR片,检查下尺桡关节稳定性,采用Sarmiento改良的Gartland-Werley评分系统(GW评分)对腕部进行功能评估。结果:85例获得6~9个月随访,平均6.7个月。19例有下尺桡关节不稳定。下尺桡关节不稳与放射学检查下尺桡关节情况之间无明显的联系。下尺桡关节不稳的患者GW评分平均为12.37±5.899,稳定的患者GW评分平均为6.85±4.222,差异有统计学意义。尺骨茎突是否骨折其GW评分差异无统计学意义。是否有尺骨茎突骨折其下尺桡关节不稳发生率比较差异无统计学意义。结论:明显成角或短缩畸形的桡骨远端骨折损伤三角纤维软骨复合体可能是造成下尺桡关节不稳、影响腕部功能的主要原因。伴随桡骨远端骨折的尺骨茎突骨折对下尺桡关节稳定性无明显影响。     

Dorsoradial avulsion of the triangular fibrocartilage complex with an avulsion fracture of the sigmoid notch of the radius

We report two extremely rare cases of dorsal radial avulsion injury of the triangular fibrocartilage complex accompanied by an avulsion fracture of the sigmoid notch of the radius. Anatomical reduction of the bone fragment in conjunction with reattachment of the dorsal portion of the radioulnar ligament to the radial sigmoid notch were necessary to restore stability of the distal radioulnar joint and tension of the triangular fibrocartilage proper.     

The dorsal approach to the distal radioulnar joint

A number of different disorders or injuries require surgical intervention at the distal radioulnar joint. Depending on the underlying condition, the distal radioulnar joint is traditionally exposed via a dorsal or, less commonly, a palmar approach. Occasionally, as in the case of fractures of the distal ulna or ulnar styloid process, a lateral approach may be chosen. We describe an operative technique for a dorsal approach to the distal radioulnar joint that we have found to be extremely useful for a wide range of different pathologies. This technique not only allows excellent visualization of the head of the ulna and the distal radioulnar joint, but also the triangular fibrocartilage complex and the ulnocarpal joint as well. Furthermore, it provides a simple means of restoring normal alignment and stability to the distal radioulnar joint and the ulnar side of the carpus.     

Anatomical transosseous fixation of the deep and superficial fibers of the radioulnar ligaments

Introduction

The triangular fibrocartilage complex is in conjunction with the interosseous membrane the most important stabilizer of the distal radioulnar joint. Lesions of the triangular fibrocartilage complex may cause instability of the distal radioulnar joint with serious consequences. Therefore, the goal is to reconstruct and provide stability to prevent further harm.

Surgical technique

Based on the anatomical configuration of the radioulnar ligaments, we present a technique which addresses both the deep and the superficial fibers of the radioulnar ligaments. This surgical procedure can be performed either openly or arthroscopically assisted. Two osseous 2-mm tunnels starting from the ulnar neck to the foveal surface are created. A nonabsorbable suture is passed through the tunnels and the triangular fibrocartilage using a 20-gauge venipuncture needle in order to attach the deep fibers. Then a third osseous tunnel starting from the lateral base of the styloid process to the medial aspect is created. The suture is passed through this tunnel and through the triangular fibrocartilage and around the styloid process palmarily using the same needle as before in order to anchor the superficial fibers anatomically. After reducing the ulna head the sutures are tightened.

Conclusion

This technique is quite simple and addresses the anatomical configuration of the radioulnar ligaments.     

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.     

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.     

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.     

The value of plain X-rays in predicting TFCC injury after distal radial fractures

In this prospective study, the plain X-rays and MRI scans of 60 patients with intraarticular distal radius fractures were examined in random order. MRI evaluation revealed that 27 of the 60 patients (45%) had triangular fibrocartilage lesions. No correlation was found between triangular fibrocartilage injury and the Melone classification system, the presence of an ulnar styloid fracture, comminution of the articular surface of the distal radius, >20 degrees dorsal angulation of the distal radius or subluxation/dislocation of the distal radioulnar joint on the plain X-rays. When Frykman Type VI and VIII fractures were compared with all the other Frykman subtypes, a significant difference in the incidence of triangular fibrocartilage complex tears was observed. We conclude that triangular fibrocartilage injury should be considered with all distal radial fractures, especially the Frykman Types VI and VIII.     

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.     

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.     

Dorsal dislocation of the ulnar styloid and extensor carpi ulnaris tendon into the distal radioulnar joint: the empty sulcus sign

Two cases of distal radioulnar joint (DRUJ) disruption and diastasis secondary to distal radial fractures were associated with displacement of the ulnar styloid and extensor carpi ulnaris (ECU) into the DRUJ. Both cases had a palpable empty ECU tendon sulcus. In one case surgical exploration revealed that the ulnar styloid, triangular fibrocartilage, and extensor carpi ulnaris tendon had dislocated into the DRUJ as a unit. The end result was good. In the second case lack of recognition and reduction of the ECU tendon and ulnar styloid led to persistent subluxation and diastasis. The end result was poor. Early recognition of the dislocation of the ulnar and ECU into the DRUJ and their significance may avoid poor results.     

Distal radioulnar joint injuries

Distal radioulnar joint is a trochoid joint relatively new in evolution. Along with proximal radioulnar joint, forearm bones and interosseous membrane, it allows pronosupination and load transmission across the wrist. Injuries around distal radioulnar joint are not uncommon, and are usually associated with distal radius fractures,fractures of the ulnar styloid and with the eponymous Galeazzi or Essex_Lopresti fractures. The injury can be purely involving the soft tissue especially the triangular fibrocartilage or the radioulnar ligaments. The patients usually present with ulnar sided wrist pain, features of instability, or restriction of rotation. Difficulty in carrying loads in the hand is a major constraint for these patients. Thorough clinical examination to localize point of tenderness and appropriate provocative tests help in diagnosis. Radiology and MRI are extremely useful, while arthroscopy is the gold standard for evaluation. The treatment protocols are continuously evolving and range from conservative, arthroscopic to open surgical methods. Isolated dislocation are uncommon. Basal fractures of the ulnar styloid tend to make the joint unstable and may require operative intervention. Chronic instability requires reconstruction of the stabilizing ligaments to avoid onset of arthritis. Prosthetic replacement in arthritis is gaining acceptance in the management of arthritis.     

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.     

Resection arthroplast of the distal ulna

Controversy exists regarding the best treatment for pain and instability of the distal radioulnar joint. Until recently the Darrach distal ulna resection had been the standard procedure. The Bowers hemiresection interposition arthroplasty and the Watson matched distal ulna resection were developed to preserve the styloid attachment of the triangular fibrocartilage complex. The authors present a technique for the treatment of patients with painful distal radioulnar joints. The treatment is aimed at alleviating the problems of impingement and styloid carpal abutment during grip as well as providing stabilization. The goal is improved pain-free pronation or supination, flexion or extension, and increase in grip strength.     

Distal radioulnar joint arthroscopy and the volar ulnar portal

Pain on the ulnar side of the wrist remains poorly understood. As attention has shifted toward the myriad causes of ulnar-sided wrist pain, the utility of viewing the wrist from a volar ulnar (VU) perspective has emerged. Lunotriquetral ligament tears have been implicated in the pathogenesis of volar intercalated segmental instabilities. They often originate in the palmar subregion, which is most important for maintaining stability. These tears are difficult to visualize through the 4, 5, or 6R portals. They are well seen through a VU portal, and the direct line of sight facilitates debridement. The VU portal has potential use in the arthroscopic diagnosis and treatment of patients with injuries to the ulnar sling mechanism. It aids in triangular fibrocartilage repairs especially those involving the dorsal aspect between the ulnar styloid and the radial insertion, because the proximity of the 4, 5, and 6R portals makes triangulation of the instruments difficult. Although arthroscopy of the dorsal aspect of the distal radioulnar joint has been well described, it has largely remained a curiosity, with few clinical indications. Recent biomechanical studies have highlighted the importance of the deep attachment of the triangular fibrocartilage complex in maintaining distal radioulnar joint stability. The volar distal radioulnar portal is useful for assessing the foveal attachment. It may be used where there is the suspicion of a peripheral triangular fibrocartilage detachment due to a loss of its normal tension despite the lack of a visible tear during radiocarpal arthroscopy. The judicious use of these portals deserves consideration for inclusion as part of a thorough arthroscopic examination of selected patients with ulnar-sided wrist pain.     

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.     

Management of acute triangular fibrocartilage complex injury of the wrist

Acute trauma to the triangular fibrocartilage complex includes tears of the fibrocartilage articular disk substance and meniscal homolog as well as radioulnar ligament avulsions, with or without an associated fracture. Patient evaluation includes clinical examination, imaging studies, and wrist arthroscopy (diagnostic). The Palmer classification is typically used to define injuries to the triangular fibrocartilage complex. The critical distinction is in differentiating injuries that produce instability of the distal radioulnar joint from those that do not. Also important is the recognition of acute injuries in the context of an ongoing degenerative pattern (ie, Palmer class 2 lesions). Nonsurgical management includes temporary splint immobilization of the wrist and forearm, oral nonsteroidal anti-inflammatory medication, corticosteroid joint injection, and physical therapy. Surgical strategies include débridement, acute repair, and subacute repair. Most surgical procedures can be performed arthroscopically. However, open ligament repair may be needed in the setting of distal radioulnar joint 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.     

The "wafer" procedure. Partial distal ulnar resection.

A technique of partial resection of the distal ulna ("wafer" procedure) for the treatment of patients with symptomatic tears of the triangular fibrocartilage complex or mild ulnar impaction syndrome or both is described. The distal 2-4 mm of the distal ulna is resected while preserving the distal radioulnar joint and the styloid process of the ulna and the ligaments attached to it. The triangular fibrocartilage can be debrided, repaired, or partially excised. The wafer procedure has several advantages and avoids some of the potential complications of other treatment methods.     

The dorsopalmar stability of the distal radioulnar joint

Sixteen fresh-frozen adult human cadaveric upper extremities were used in a biomechanical analysis of distal radioulnar joint (DRUJ) stability. The relative contribution to stability of the DRUJ by the surrounding anatomic structures presumed to stabilize the joint was analyzed with respect to forearm rotation and wrist flexion and extension using a purpose-built 4-axis materials testing machine. The dominant structures stabilizing the DRUJ were the ligamentous components of the triangular fibrocartilage complex proper. The major constraint to dorsal translation of the distal ulna relative to the radius is the palmar radioulnar ligament. Palmar translation of the distal ulna relative to the radius is constrained primarily by the dorsal radioulnar ligament, with secondary constraint provided by the palmar radioulnar ligament and interosseous membrane. The ulnocarpal ligaments and extensor carpi ulnaris subsheath did not contribute significantly to DRUJ stability; however, approximately 20% of DRUJ constraint is provided by the articular contact of the radius and ulna. These relationships were consistent regardless of wrist position or degree of forearm rotation.