Effects of radioulnar instability on the radiocarpal joint: a biomechanical study

Five fresh cadaver upper extremities were studied with use of a static positioning frame, pressure-sensitive film and a microcomputer-based videodigitizing system to assess the effect of increasing radioulnar instability on the load distribution within the proximal carpal joint. Three stages of radioulnar instability were studied: (1) an avulsion fracture at the base of the ulna styloid; (2) an avulsion fracture at the base of the ulna styloid plus disruption of the dorsal portion of the distal radioulnar joint capsule; and (3) an avulsion fracture at the base of the ulna styloid, disruption of the dorsal portion of the distal radioulnar joint capsule, and disruption of the radioulnar interosseous membrane. All stages of radioulnar instability demonstrated a decrease in the lunate contact area in positions with the forearm in supination. In stage 3 instability there was also less lunate contact area in positions with the forearm in neutral pronation/supination. In stage 3 instability the lunate high pressure area centroid was abnormally palmar in all positions and the scaphoid high pressure area centroid was abnormally palmar in positions with the forearm in pronation or supination.     

Malunion of a Complex Fracture of the Distal Radioulnar Joint (DRUJ)

Background: Generating an artificial spontaneous Sauvé-Kapandji situation after malunion of the distal radioulnar joint (DRJU) enables a patient to move forearm and wrist without pain.Case Study: A patient with an extensive combined fracture of the distal radius and ulna accompanied by a subluxation of the ulnar head and an avulsion fracture of the base of the ulnar styloid was treated with external fixator. During follow-up, an artificial fracture was observed at a former pin site. This led to nonunion approximately 3 cm proximal to the ulnar head. Comparable to a spontaneously generated Sauvé-Kapandji situation, the development of this nonunion resulted in a pain-ree situation allowing free movement of forearm and wrist. The extend of motion was 70°/0°80° pronation/supination.     

尺骨茎突骨折对外固定架治疗桡骨远端骨折的影响

目的探讨尺骨茎突骨折对外固定支架治疗不稳定性桡骨远端骨折疗效的影响。方法回顾性分析118例不稳定性桡骨远端骨折患者的随访资料。根据尺骨茎突骨折情况分为:A组(尺骨茎突基底部骨折)、B组(尺骨茎突尖部骨折)、C组(无尺骨茎突骨折)。所有患者均采用外固定支架治疗,尺骨茎突骨折不做任何治疗,术后6~8周拆除外固定支架,平均随访15.3个月,终末随访时行影像学参数(掌倾角、尺偏角、桡骨高度)、腕关节活动度(掌屈、背伸、尺偏、桡偏、旋前、旋后)及Gartland-Werley评分测定。结果终末随访时三组病例之间在影像学参数、腕关节活动度及Gartland-Werley评分方面均未发现统计学差异。结论采用外固定支架治疗不稳定性桡骨远端骨折时,若下尺桡关节稳定,对伴有的尺骨茎突骨折可不做任何治疗。     

Irreducible Galeazzi fracture-dislocation due to an avulsion fracture of the fovea of the ulna.

We report a rare case of Galeazzi fracture-dislocation with an irreducible distal radioulnar joint. The cause of the irreducibility was entrapment of a fragment avulsed from the fovea of the ulna. The patient was successfully treated with open reduction and internal fixation of the radius, ulnar styloid process and avulsed fracture at the fovea of the ulna.     

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.     

Ulnar wrist pain after Colles' fracture: 109 fractures followed for 4 years

109 patients with unilateral Colles' fracture, treated with closed reduction and cast immobilization, were re-examined after 4 (1-9) years. At follow-up, 40 patients had persistent ulnar wrist pain. The most important factor for predicting ulnar pain was final dorsal angulation of the radius. Initial and final radial shortening, fracture of the distal radioulnar joint, ulnar styloid fracture, or instability of the distal ulna were not correlated to ulnar wrist pain. We suggest that ulnar wrist pain following Colles' fracture is caused by incongruity of the distal radioulnar joint.     

手法间接复位掌侧锁定板固定治疗桡骨远端C3型骨折

目的 ：探讨手法间接复位后AO 2.4 mm桡骨远端锁定板联合经皮穿针固定治疗C3型（AO/OTA分型）桡骨远端骨折的临床疗效及操作技巧。方法：自2009年5月至2012年3月采用手法间接复位AO 2.4 mm桡骨远端掌侧锁定板联合经皮穿针固定治疗桡骨远端骨折AO/OTA分型C3型患者19例21腕（双侧2例）。年龄31~66岁,平均（45.3±17.4）岁;并发尺骨茎突骨折14腕,下尺桡关节不稳6腕;均为闭合性骨折;发病时间4.5~9 d,平均（6.7±3.5）d。采用Henry切口显露骨折部位,保留关节囊、韧带连续性,手法间接复位,C形臂X线透视关节面复位情况,仍存在塌陷者予以撬拨复位后桡骨远端掌侧锁定板固定。下尺桡关节发现不稳定和并发尺骨茎突骨折者均予前臂旋后位石膏托固定6周。结果：19例（21腕）获得随访,时间7~17个月,平均10.5个月。X线示患者桡骨远端骨折均达到骨性愈合,尺骨茎突骨折未愈合3例,下尺桡关节不稳0例,1例出现背侧伸肌腱激惹,内固定取出后激惹消除。术后随访观测患者掌倾角、尺偏角、桡骨茎突高度、关节面和下尺桡关节情况,按照Batra和Gupta评分标准行影像学评定：70分以下3腕,70~79分5腕,80分以上13腕。同时对患者进行主观和客观疗效评定,观测残留畸形和腕关节活动度、并发症情况等,根据Sarmiento改良的Gartland-Werley评分系统评定术后疗效：优17腕,良3腕,可1腕。结论：AO/OTA分型C3型桡骨远端骨折手法间接复位可获得良好复位效果,应用锁定板联合穿针可为其提供内固定架支撑式固定以满足早期功能锻炼要求,患腕功能预后良好。     

Biomechanical analysis of two ulnar head prostheses

The biomechanical effectiveness of 2 ulnar head prostheses was evaluated in 5 fresh-frozen cadaver arms. By using electromagnetic sensors, the amount of forearm rotation, diastasis, and dorsal/palmar subluxation of the radius at the level of the sigmoid notch was measured with the forearm in neutral rotation, pronation, and supination with and without dorsal/palmar loading. Testing was done in the intact specimens and after insertion of 2 types of ulnar head prostheses. Dynamic forearm rotation was also achieved by applying loads in the line of action of the appropriate pronator or supinator muscles to obtain a centroidal path of the radius relative to the ulna. Overall after ulnar head replacement forearm rotation lessened in pronation, diastasis decreased in most forearm positions, and subluxation increased in supination compared with the intact specimen. Despite these changes, both prostheses maintained near-normal biomechanics of the distal radioulnar joint when compared with the irregular behavior occurring after distal ulna resection. Therefore these prostheses are suggested for restoration of distal radioulnar joint function.     

Isolated radial shaft fractures are more common than Galeazzi fractures

PURPOSE: In contrast to isolated diaphyseal fractures of the ulna (so-called night-stick fractures), isolated fractures of the radial diaphysis generally are expected to have associated injury of the distal radioulnar joint (DRUJ), the so-called Galeazzi fracture. This study retrospectively reviewed isolated fractures of the radial diaphysis in a large cohort of patients to determine how often such fractures occur without DRUJ injury METHODS: Thirty-six patients with fracture of the radius without fracture of the ulna were followed up for at least 6 months after injury. Injury of the DRUJ was defined as more than 5 mm of ulnar-positive variance on radiographs taken before any manipulative or surgical reduction. All of the fractures were treated with plate and screw fixation (8 with autogenous bone grafting) and all healed. Patients with DRUJ injury had either temporary pinning or immobilization of the DRUJ or surgical fixation of a large ulnar styloid fracture. Patients without DRUJ injury were mobilized within 2 weeks. RESULTS: Nine patients had dislocation of the DRUJ, 4 with large ulnar styloid fractures. Among the remaining 27 patients 1 had displacement of the proximal radioulnar joint noted after surgery, leading to a secondary procedure for radial head resection. The functional results were satisfactory or excellent in all but 2 patients with functional limitations related to central nervous system injury. No patient had DRUJ dysfunction at the final follow-up evaluation. CONCLUSIONS: Isolated fractures of the radial diaphysis are more common than true Galeazzi fractures. Surgeons should take great care not to overlook injury to the distal or proximal radioulnar joint in association with isolated diaphyseal fractures of the radius; however, fractures without identifiable radioulnar disruption can be treated without specific treatment of the DRUJ and with immediate mobilization. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic, Level IV.     

Ulnar bursa distention following volar subluxation of the distal radioulnar joint after distal radial fracture: a rare cause of carpal tunnel syndrome

This report describes an eighty-four-year-old woman with persistent carpal tunnel syndrome attributable to an ulnar bursa distention associated with the subluxation of the distal radioulnar joint after distal radial fracture. During surgery, when the forearm was placed in supination, the ulna head with a sharp osteophyte was found to be displaced into the carpal tunnel through a defect of the ruptured capsule of the wrist joint. This volar subluxation of the ulnar head had caused distention of the ulnar bursa, causing compression of the median nerve, which resulted in carpal tunnel syndrome. In addition to reduce displaced fractured segment to obtain anatomic articular surface, original radial length and tilt, the anatomic restoration of the distal radioulnar joint is essential to maintain better long-term function after fracture of the distal radius.     

Bilateral traumatic dislocation of the distal radioulnar joint, ulna dorsal: case report and review of the literature

Bilateral dislocation of the distal radioulnar joint seems not to have been reported in the literature. This is a report of a 22-year-old man successfully treated with closed reduction and immobilization in long arm casts. Limited forearm rotation and wrist pain after a twisting injury are typical findings. In ulna dorsal dislocation the patient's forearm is locked in pronation. In ulna volar dislocation the wrist appears narrow and the forearm is locked in supination. The mechanism of injury for dorsal dislocations is hyperpronation; for volar dislocations it is hypersupination. Dislocation of the distal radioulnar joint injures the triangular disk and/or fractures the ulnar styloid. Suspicion is important in making the diagnosis. Fifty per cent of unilateral cases reported in the literature were missed initially or were diagnosed late. The acute case is easily treated by closed reduction under local anesthesia and immobilization in a long arm cast. Treatment of the chronic dislocation includes various soft tissue reconstructions or resection of the distal ulna depending on the degree of arthrosis.     

The Influence of Non-union of the Ulnar Styloid on Pain, Wrist Function and Instability after Distal Radius Fracture

The influence of non-union on the outcome of distal radius fractures is debated. We tested the null hypothesis that there is no difference in pain, wrist function, or instability between patients with union or non-union of an ulnar styloid base fracture after operative treatment of a fracture of the distal radius. Eighteen adults with an ulnar styloid base non-union were compared to 16 patients with union of an ulnar styloid base fracture with a mean post-operative follow-up of 30 months. None of the patients had distal radioulnar joint instability, there were no significant differences in pain, complications, or function, and patients with nonunion had significantly greater grip strength. Ulnar styloid nonunion is not associated with pain, instability, or diminished function after fracture of the distal radius.     

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。     

Free fibula and corticocancellous bone grafting for salvage of a war-injured forearm

The treatment of a complex forearm injury inflicted by a wartime mine explosion is presented in this study. Apart from the soft tissue damage, a 4-part fracture of the radius and loss of 19 cm of the ulnar diaphysis were present along with lesions of the median and ulnar nerves. The radial pulse was intact. The first formal treatment of the wounding consisted of extensive soft tissue and bone debridement and external fixation of radius with an additional intramedullary K-wire. After wound closure was obtained, a free vascular fibula grafting of the ulna and corticocancellous bone grafting of the radius were performed. Bone union of both the radius and ulna was subsequently achieved and 9 years after the injury, the patient has full flexion and extension of the elbow, full pronation and 70% of supination. Motion of the wrist is limited because of an ulnar plus variant of the distal radioulnar joint. Hand function is still limited by chronic low-moderate median nerve palsy, but the ulnar nerve has recovered completely. The patient is able to pinch, has full finger extension and can make a fist. He is satisfied that he made the correct decision in not having an initial amputation for his injury.     

Outcome Following Acute Primary Distal Ulna Resection for Comminuted Distal Ulna Fractures at the Time of Operative Fixation of Unstable Fractures of the Distal Radius

Optimal acute management of the highly comminuted distal ulna head/neck fracture sustained in conjunction with an unstable distal radius fracture requiring operative fixation is not well established. The purpose of the present study was to determine the clinical, radiographic, and functional outcomes following acute primary distal ulna resection for comminuted distal ulna fractures performed in conjunction with the operative fixation of unstable distal radius fractures. Between 2000 and 2007, 11 consecutive patients, mean age 62 years (range, 30–75) were treated for concomitant closed, comminuted, unstable fractures of the distal radius and ulna metaphysis. All 11 patients underwent distal ulna resection through a separate dorsal ulnar incision with ECU tenodesis following surgical fixation of the distal radius fracture. According to the Q modifier of the Comprehensive Classification of Fractures, there were six comminuted fractures of the ulnar neck (Q3) and five fractures of the head/neck (Q5). Operative fixation of the distal radius fracture included volar plate fixation in four patients and spanning external fixation with supplemental percutaneous Kirschner wires in seven patients. At a mean of 42 months (range, 18–61 months) postoperatively, clinical, radiographic, and wrist-specific functional outcome with the modified Gartland and Werley wrist score were evaluated. At latest follow-up, mean wrist range of motion measured 53° flexion (range, 35–60°), 52° extension (range, 30–60°), 81° pronation (range, 75–85°), and 77° supination (range, 70–85°). Mean grip strength measured 90% of the contralateral, uninjured extremity (range, 50–133%). No patient had distal ulna instability. Final radiographic assessment demonstrated restoration of distal radius articular alignment. According to the system of Gartland and Werley as modified by Sarmiento, there were seven excellent and four good results. No patient has required a secondary surgical procedure. Acute primary distal ulna resection yields satisfactory clinical, radiographic, and functional results in appropriately selected patients and represents a reliable alternative to open reduction and internal fixation when anatomic restoration of the distal ulna/sigmoid notch cannot be achieved. Primary distal ulna resection with distal radius fracture fixation may help avoid secondary procedures related to distal ulna fixation or symptomatic post-traumatic distal radioulnar joint arthrosis.     

Does an ulnar styloid fracture interfere with the results of a distal radius fracture?

Background  

The ulnar styloid is a supportive structure for the capsular ligament complex of the distal radioulnar joint. The relation between fractures of the ulna and distal radius is not clear, especially in regard to whether ulnar fractures predict worse outcomes for distal radius fractures. The objective of this study was to analyze the influence of ulnar styloid fractures in patients with reducible and unstable distal radius fractures.     

Ulnar nerve palsy associated with fracture of the distal radius

OBJECTIVE: To describe the clinical features and outcome of a series of patients with complete motor and sensory ulnar nerve palsy associated with a fracture of the distal radius. DESIGN: Retrospective case series. SETTING: Level 1 trauma center. PATIENTS/PARTICIPANTS: Five adults with acute complete motor and sensory ulnar nerve palsy associated with fracture of the distal radius were treated during a 2 year period. There were 3 men and 2 women, with an average age of 42 years (range, 33 to 56 years). All 5 distal radius fractures were high energy and widely displaced. Three patients had an associated ulna fracture (2 styloid, 1 styloid and distal diaphysis), and 1 had a complete triangular fibrocartilage complex (TFCC) avulsion from the distal ulna (associated with an open wound). Two patients had open fractures. INTERVENTION: Open reduction and internal fixation of the distal radius fracture in 4 patients and external fixation in 1 patient. Three patients had exploration and release of the ulnar nerve because it was associated with an acute carpal tunnel syndrome. MAIN OUTCOME MEASUREMENTS: Recovery of ulnar nerve function. RESULTS: At an average follow-up of 17 months, 4 patients had complete or near-complete recovery of ulnar nerve function. One patient had moderate motor and mild sensory dysfunction. CONCLUSIONS: Acute ulnar nerve palsy may occur in association with high-energy, widely displaced fractures of the distal radius. These are usually neurapraxic injuries that recover to normal or near-normal strength and sensation. We recommend exploration and release of a complete ulnar nerve palsy associated with a fracture of the distal radius fracture when there is an open wound or an acute carpal tunnel syndrome, and observation without exploration otherwise.     

The distal radioulnar joint in relation to the whole forearm.

The functional anatomy of the distal radioulnar joint was studied in relation to the whole forearm, using three fresh-frozen, above-elbow amputation specimens. The specimens demonstrate how the proximal and distal radioulnar joints together form a bicondylar joint of special character. The proximal "condyle," the radial head, rotates axially, whereas the distal "condyle," the ulnar head, is fixed with respect to rotation. The ordinary articulation of a bicondylar joint (pure axial rotation) is thereby changed into pronation-supination. Axial rotation is preserved proximally, while distally the radius swings around the ulnar head. The mobile radius is distally attached to the stable ulnar head by the dorsal and volar radioulnar ligaments, the dorsal ligament being tight for stabilization in supination and the volar ligament being tight in pronation. The ulnar head also serves as a keystone, carrying the load of the radius. Removal of the ulnar head allows the radius to "fall in" towards the ulna, with narrowing of the interosseous space.     

Condylar blade plate fixation of unstable fractures of the distal ulna associated with fracture of the distal radius

PURPOSE: To review the results of condylar blade plate fixation of unstable fractures of the distal ulna associated with fracture of the distal radius. METHODS: Twenty-four patients in whom a minicondylar blade plate was used to repair an unstable fracture of the distal ulna associated with a fracture of the distal radius were reviewed retrospectively an average of 26 months (range, 12-50 months) after injury. According to the Q modifier of the Comprehensive Classification of Fractures, there were 1 simple fracture of the ulnar neck (Q2), 20 comminuted fractures of the ulnar neck (Q3), and 3 fractures of the head and neck (Q5). Subsequent surgeries included repeat fixation and autogenous cancellous bone grafting in 2 patients with nonunion of the distal radius and 1 with nonunion of the distal ulna. Seven patients had a second operation to remove the ulnar plate secondary to discomfort from plate prominence. RESULTS: The final average motion was as follows: degrees of flexion (range, 30 degrees-80 degrees), 52 degrees of extension (range, 40 degrees-90 degrees), 76 degrees of pronation (range, 45 degrees-90 degrees), and 70 degrees of supination (range, 45 degrees-90 degrees). Grip strength averaged 64% of the contralateral, uninjured extremity (range, 35%-100%). Final radiographic measurements included an average palmar tilt of the distal articular surface of the radius of 8 degrees (range, 0 degrees-20 degrees of palmar tilt), ulnar inclination of 21 degrees (range, 15 degrees-25 degrees), and ulnar positive variance of 1 mm (range, 0-4 mm). There were no problems related to the distal radioulnar joint. According to the system of Gartland and Werley as modified by Sarmiento, there were 6 excellent, 15 good, and 4 fair results at final evaluation. CONCLUSION: For unstable fractures of the distal ulna associated with fracture of the distal radius, condylar blade plate fixation can achieve healing with good alignment, satisfactory function, and an acceptable rate of secondary surgery.     

Open reduction and internal locked fixation of unstable distal ulna fractures with concomitant distal radius fracture

PURPOSE: To evaluate the results following locking plate fixation of unstable distal ulna fractures with concomitant distal radius fracture. METHODS: A retrospective review was conducted to identify patients who had been treated with a locking plate for unstable displaced fractures of the distal ulna in which a concomitant ipsilateral distal radius fracture was also treated operatively. Medical records and radiographs were reviewed, and 5 patients were identified with an average age of 52 years (range, 47-61 years) and with follow-up averaging 11.6 months (range, 6-17 months). There were 2 open and 3 closed fractures. Included was 1 simple neck, 1 comminuted neck, 1 head, and 2 head and neck fractures of the distal ulna. All distal radius fracture implants were locked volar plates. RESULTS: All distal ulna and distal radius fractures united, and the average motion was: flexion 59 degrees ; extension 59 degrees ; pronation 67 degrees ; and supination 72 degrees . Average grip strength was 97% of the opposite extremity. Final ulnar variance averaged -0.4 mm (ulnar negative), radial inclination was 20 degrees , and volar tilt was 8 degrees . All distal radioulnar joints were stable. Two patients had mild, transient paresthesias of the dorsal sensory branch of the ulnar nerve, and both patients recovered completely within 3 months. There were no subsequent surgeries or hardware failures. There were no infections and no wound problems. Based upon the Sarmiento modification of the Gartland and Werley rating score, there were 4 excellent results and 1 good result. CONCLUSIONS: Locked plating of unstable distal ulna fractures, in the setting of an associated distal radius fracture, resulted in union, good to excellent alignment and motion, nearly symmetric grip strength, and minimal transient morbidity.