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.     

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.     

Arthroplasty of the distal radioulnar joint using a new ulnar head endoprosthesis: preliminary report

PURPOSE: To report our experience using a distal ulnar head endoprosthesis to treat painful disorders of the distal radioulnar joint (DRUJ) secondary to (1) instability and (2) arthrosis. METHODS: Our experience with over 2 years of follow-up study consists of 19 wrists (17 patients). All patients presented complaining of pain and functional disability of the upper limb due to convergence instability or arthrosis of the DRUJ. The patients were studied prospectively. Thirteen patients had a total of 37 previous wrist or DRUJ surgical procedures. Standardized preoperative and postoperative assessments included a patient-reported pain score, a functional satisfaction score, forearm range of motion, grip strength as a percentage of that of the opposite limb, and clinical and radiographic examinations. The Mayo Wrist Score was calculated before surgery and at the last follow-up period. RESULTS: Overall, pain scores decreased 50%, and functional satisfaction scores improved 3-fold. Average grip strength improved by 4 kg, or 16% from preoperative measurements. Forearm rotation was unchanged. All wrists were clinically stable on the latest follow-up examination. Two failures occurred early, at 7 and 14 months. Currently, all prostheses remain clinically and radiographically stable. CONCLUSIONS: Implant arthroplasty of the distal ulna combined with an adequate soft-tissue repair is recommended to improve pain, function, and strength of the wrist and forearm. Prosthetic replacement of the distal ulna restored stability to the DRUJ in patients with partial or complete excision of the ulnar head or DRUJ arthrosis and corrected radioulnar impingement. Incidences of complications or revision surgery to date have been low. Larger clinical and radiographic assessments will be needed to determine the long-term success of distal ulna prosthetic replacement. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.     

Symptoms and radiographic findings in the proximal and distal ulnar stumps after the Sauvé-Kapandji procedure for treatment of chronic derangement of the distal radioulnar joint

PURPOSE: We analyzed correlations between symptoms and radiographic findings with respect to the proximal and distal ulnar stumps after the Sauvé-Kapandji procedure for treating chronic derangement of the distal radioulnar joint. METHODS: A total of 26 patients were studied (13 men, 13 women) with a mean age of 46 years at examination. Clinical assessment included elicitation of postoperative symptoms related to the proximal and distal ulnar stumps. In the radiographic study the radioulnar distance in the neutral wrist position and the presence or absence of scalloping at the radius were determined from posteroanterior (PA) views. The total mobility distance of the proximal ulnar stump was measured on the PA and lateral views while the wrist moved from radial to ulnar deviation or from extension to flexion. RESULTS: Eleven patients complained of tenderness over the distal ulnar stump and 5 patients felt discomfort around the proximal ulnar stump during forearm rotation. The postoperative radioulnar distance in patients with tenderness was significantly smaller than in the group without tenderness. Scalloping at the radius was shown in 9 patients but it was not related to the radioulnar distance. The total mobility distance of the proximal ulnar stump on the PA view was significantly greater in patients with tenderness than in those without, and it also was significantly greater in patients with scalloping than in those without. The total mobility distance on the lateral view was significantly greater in the group with discomfort than in the group without discomfort. CONCLUSIONS: The radioulnar distance was related to tenderness over the distal ulnar stump but not to the scalloping. Tenderness and scalloping each were related to radioulnar instability of the proximal ulnar stump. Discomfort around the proximal ulnar stump was related to dorsovolar instability of the stump. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic, Level IV.     

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.     

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.     

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.     

Ulnar styloid fractures associated with distal radius fractures: incidence and implications for distal radioulnar joint instability

Ulnar-sided injuries of the wrist have received more attention recently for their potential negative impact on the outcome of distal radius fractures. Radiographs and medical records were retrospectively reviewed for 166 distal radius fractures treated during a 1-year interval. Distal radius fractures were classified according to the AO system, and accompanying ulnar styloid fractures were evaluated for both size and displacement. Each distal radius fracture was also evaluated for radiographic and clinical evidence of distal radioulnar joint instability. The distribution of ulnar styloid fractures was not random; greater than one third involved the base. All distal radius fractures complicated by distal radioulnar joint instability were accompanied by an ulnar styloid fracture. A fracture at the ulnar styloid's base and significant displacement of an ulnar styloid fracture were found to increase the risk of distal radioulnar joint instability.     

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.     

Comparison between high-resolution MRI with a microscopy coil and arthroscopy in triangular fibrocartilage complex injury

PURPOSE: To determine whether high-resolution magnetic resonance imaging (MRI) could detect injuries to the triangular fibrocartilage complex (TFCC). METHODS: Eleven patients who showed both a positive sign during the ulnocarpal stress test and tenderness at the distal end of the ulna had a high-resolution MRI using a 47-mm diameter microscopy coil. Six regions of the TFCC were investigated for injury: the radial attachment, disc, ulnar attachment of the triangular fibrocartilage (TFC), ulnotriquetral ligament, palmar radioulnar ligament (PRUL), and dorsal radioulnar ligament (DRUL). Arthroscopy was performed subsequently on each patient. RESULTS: For injuries to the radial attachment or the disc of the TFC, a high-resolution MRI showed 100% sensitivity and 100% specificity compared with arthroscopy. In 3 cases in which injury to the ulnar attachment of the TFC was detected with MRI and examination showed a positive piano-key sign and distal radioulnar joint instability, only 1 injury was confirmed with arthrotomy. For MRI diagnosis of an ulnotriquetral ulnolunate attachment injury, the sensitivity was 100% and the specificity was 70%; however, 3 cases had false-positive results. Finally MRI had 100% sensitivity for detecting DRUL and PRUL injuries, although specificities were 75% and 83%, respectively. With MRI there were 2 false-positive DRUL injury diagnoses and 1 false-positive PRUL injury diagnosis. CONCLUSIONS: High-resolution MRI using a microscopy surface coil allowed assessment of each TFCC component and showed a higher accuracy for diagnosing injuries to the radial attachment and the disc of the TFC compared with previous studies. High-resolution MRI, however, was not able to diagnose DRUL, PRUL, or ulnolunate ligament injuries accurately. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic III.     

The management of congenital and acquired problems of the distal radioulnar joint in children

Pain in the ulnar aspect of the pediatric wrist is an uncommon problem; however, when pain does occur it is usually the result of antecedent bony trauma or an underlying skeletal abnormality, which may lead to ulnar-sided wrist pain of varying etiology. The clinician must to be able to identify these entities within the pediatric wrist in order to make the appropriate diagnosis and plan for surgical intervention to prevent ongoing damage to the distal radioulnar joint (DRUJ). This article reviews the etiology, clinical presentation, and treatment strategies for the management of the unique problems that can affect the pediatric and adolescent DRUJ.     

Sauvé-Kapandji手术治疗桡尺远侧关节脱位和关节炎

目的 评价Sauve-Kapandji手术治疗桡尺远侧关节脱位和关节炎的临床疗效.方法 采用Sauve-Kapandji手术治疗桡尺远侧关节脱位和关节炎12例.随访内容包括手术前后腕关节疼痛程度、腕关节活动度、握力以及术后患侧X线片情况.X线片检查观察桡尺远侧关节愈合及测量尺桡骨间距.Mayo腕关节评分法评价手术前、后腕关节功能恢复程度,DASH问卷调查表行手术前、后腕关节功能自我评价.结果 术后随访9～32个月,平均16个月.术前腕关节疼痛值在负重后为[(39.0±17.0),(x)±s,下同],术后疼痛值为(23.0±13.0).尺桡偏活动度术前为(26.0±11.0)°,术后为(41.0±12.0)°;旋前、旋后活动度术前为(84.0±21.0)°,术后为(139.0±33.0)°.握力术前为(12.8±3.6)kg,术后为(24.0±7.4)kg.Mayo评分结果术前为(43.0±13.0),术后为(73.0±16.0),优3例,良4例,中3例,差2例.DASH值术前为(57.0±14.0),术后为(31.0±10.0).X线片检查12例桡尺远侧关节及尺骨移植处全部愈合.结论 Sauve-Kapandji手术治疗桡尺远侧关节脱位和关节炎,疼痛明显减轻,旋转活动度和握力增加,功能明显改善.     

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.     

The incidence of dorsal radiocarpal ligament tears in patients having diagnostic wrist arthroscopy for wrist pain

PURPOSE: The goal of this study was to examine the incidence of dorsal radiocarpal ligament (DRCL) tears in patients having diagnostic arthroscopy for chronic wrist pain. METHODS: A chart review was performed of 64 patients who had diagnostic wrist arthroscopy for chronic wrist pain that was refractory to conservative measures. For each case, interosseous ligament instability/tears were graded according to the Geissler classification. Tears of the triangular fibrocartilage complex and the presence or absence of a DRCL tear were noted. RESULTS: There were 35 of 64 wrists (in 64 patients) with DRCL tears. The average duration of wrist pain prior to treatment was 20 months. Only 10 patients could recall a specific injury. Five patients had an isolated DRCL tear. A scapholunate interosseous ligament injury was identified in 13 patients, of whom 7 had a concomitant DRCL tear. A lunotriquetral interosseous ligament injury was present in 7 patients, of whom 2 had a concomitant DRCL tear. Two patients had a capitohamate ligament tear: 1 of these patients had a DRCL tear. There were 7 patients with a solitary triangular fibrocartilage complex tear: 6 of 7 were in association with a DRCL tear. One patient had a chronic ulnar styloid nonunion and a DRCL tear. Two or more lesions were present in 23 patients; DRCL tears were present in 12. CONCLUSIONS: DRCL tears are commonly seen with injuries to the primary wrist stabilizers. Recognition of this condition and further research into treatment methods are needed. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic IV.     

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.     

Kinematics of ulnar head arthroplasty

This in vitro study evaluated the performance of an ulnar head replacement. A joint simulator was employed that produced active forearm rotation in cadaveric specimens, with motion measured using an electromagnetic tracking system. The kinematics of the intact forearm were compared with a partial ulnar head replacement and a full replacement (with and without soft-tissue reconstruction) and a full excision of the ulnar head. There were no differences between intact kinematics and those following prosthetic reconstruction. However, ulnar head excision produced distal radioulnar joint instability in the form of radioulnar convergence and increased anteroposterior translations.     

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.     

An analysis of causes and treatment outcome of chronic wrist pain after distal radial fractures

Healed distal radial fractures are frequently complicated by chronic wrist pain which is multifactorial and can be debilitating. An accurate delineation of the pathoanatomy is the key for successful treatment. This study reviewed 22 patients who had surgical treatment between 1997 and 2001 for chronic wrist pain after distal radial fracture. Four patterns of pathoanatomy were identified: (1) ulnar impaction caused by radial malunion and shortening; (2) ulnar styloid non-union; (3) triangular fibrocartilage complex (TFCC) tears with or without distal radioulnar joint (DRUJ) instability; and (4) intercarpal ligament injuries and chondral lesions. Surgical treatment directed towards identified abnormalities gave satisfactory outcome. At six months after surgery the mean functional score improved 36%, mean pain score decreased 50%, mean grip strength improved 25%, and 64% of patients returned to work.     

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.