The importance of the distal radioulnar joint for reconstructive procedures in the malunited distal radius fracture

Clinically most patients complain about ulnar sided wrist pain and limited forearm rotation following malunited distal radius fractures. Possible bony reasons consist of intraarticular incongruency, malalignment of the sigmoid notch of the distal radius or the ulna-plus-situation at the wrist level. A persisting luxation of the distal radioulnar joint (DRUJ) will present itself with complete loss of forearm rotation. The ligamentous or bony detachment of the triangular fibrocartilage complex (TFCC) will lead to instability of the DRUJ. Uncorrected, each of these components will lead to arthrosis of the DRUJ. The presence of arthrosis only allows salvage procedures for the DRUJ and will lead to functional loss. Reconstructive options consist of radius correction osteotomy, ulnar shortening osteotomy, reposition of a luxation and refixation of the TFCC. To chose the necessary reconstructive procedure, the individual pathological situation has to be analysed.     

Corrective osteotomy of malunited distal radius fractures

The malunion of the distal radius may result in shortening, radial impaction, volar angulation, dorsal displacement or rotatory deformity. For restoration, the anatomy and kinematics of the distal radioulnar joint and the triangular fibrocartilaginous complex (TFCC) are of importance. This nonunion consists of the articular disk, a meniscus homologue, the ulnar collateral ligament, and the dorsal and palmar radioulnar ligaments. Malunion of the distal radioulnar joint leads to an increase in loading on the individual parts, as well as pain and a decrease in supination and pronation. Osteotomy is indicated if the angulation of the malunion is more than 20 degrees in the frontal or sagittal plane. Corrective osteotomy requires detailed preoperative planning with calculation of the correct position in all planes. The most common operation that has proved to be effective is osteotomy of the radius, insertion of a trapezoidal bone graft in place, and internal fixation with a dorsal or volar plate.     

Median neuropathy in malunited fractures of the distal radius

Purpose

Irritation of the median nerve is a well-characterized complication after acute fractures of the distal radius, but there is limited literature on median neuropathy in malunited fractures. The aims of our prospective study were to estimate the prevalence of the median neuropathy, explore the relationship between radiographic findings and the condition, and investigate whether corrective osteotomy without carpal tunnel release was a sufficient treatment.

Methods

Thirty consecutive patients, who were referred to us for treatment of symptomatic distal radial malunion, underwent nerve conduction studies of both wrists by one board-certified neurologist under standardized conditions. Test results were correlated with conventional radiographic parameters (radial tilt, radial inclination, palmar shift, ulnar variance, radiolunate and capitolunate angle) and computer tomography (CT) based measurements of the cross-sectional area of the carpal tunnel. After corrective osteotomy without carpal tunnel release, 10 of 13 patients with unilateral preoperative median neuropathy agreed to an electrodiagnostic re-examination by the same neurologist.

Results

Nineteen patients demonstrated abnormal test results, but only seven patients complained about paresthesias of median-innervated fingers. There was no correlation between median neuropathy and conventional radiographic parameters. Surprisingly, the cross-sectional area of the carpal canal was significantly greater for patients with median neuropathy. Symptoms resolved in all patients after corrective osteotomy. Postoperatively, six of ten patients demonstrated improved nerve conduction studies, although only four patients demonstrated normal test results.

Discussion

There is a high rate of subclinical median neuropathy in malunited distal radial fractures that cannot be predicted by conventional radiographic parameters. Corrective osteotomy without carpal tunnel release is a sufficient treatment for neuropathy in malunited distal radius fractures.     

Rotational deformity in malunited fractures of the distal radius

PURPOSE: To evaluate rotational deformity in malunited fractures of the distal radius and its effect on forearm rotation. METHODS: Thirty-seven patients with a symptomatic malunion of the distal radius (25 with dorsal angulation and 12 with volar angulation) were assessed for rotational deformity of the distal fragment. Spiral computed tomographic scans were taken of both wrists. Rotational deformity was evaluated by comparing the radial torsion angle of the injured and uninjured sides according to Frahm. Multivariable regression analyses were used to identify the radiologic parameter that had the most important influence on forearm rotation. RESULTS: Of the 37 patients, 23 showed a rotational deformity of the distal radius. In both dorsally and volarly angulated malunions, pronation and supination deformities were identified. There was a tendency toward more pronation deformities with volar malunion. Volar angulated malunion with a rotational deformity of less than 10 degrees showed the smallest amount of forearm supination. Losses of pronation-supination did not correlate with the amount of rotational deformity. CONCLUSIONS: This study showed that rotational deformity is common with angulated malunions of the distal radius. The effect on forearm rotation should not be overestimated. Pretreatment computed tomographic scanning of both wrists to identify and measure malrotation of the distal radius may be helpful to improve the outcome after corrective osteotomy.     

Disorders of the distal radioulnar joint following fractures of the distal end of the radius

After a fracture of the distal radius, whether healed in an anatomic position or malunited, many patients complain about problems on the ulnar side of the wrist with pain and decreased range of forearm rotation. In addition many patients are unhappy with the unpleasant appearance of the wrist joint. The complaints are related to tears of the triangular fibrocartilaginous complex, instability, and/or incongruity of the distal radioulnar joint and degenerative changes. Malunion of the distal radius must be taken into account when discussing treatment options. The purpose of this paper is to describe a treatment algorithm with respect to the clinical symptoms, the pathology as well as the presence or absence of a deformity of the distal radius.     

Effects of distal radius malunion on distal radioulnar joint mechanics--an in vivo study.

Patients with a malunited distal radius often have painful and limited forearm rotation, and may progress to arthritis of the distal radioulnar joint (DRUJ). The purpose of this study was to determine if DRUJ congruency and mechanics were altered in patients with malunited distal radius fractures. In nine subjects with unilateral malunions, interbone distances and dorsal and palmar radioulnar ligament lengths were computed from tomographic images of both forearms in multiple forearm positions using markerless bone registration (MBR) techniques. The significance of the changes were assessed using a generalized linear model, which controlled for forearm rotation angle (-60 degrees to 60 degrees ). In the malunited forearm, compared to the contralateral uninjured arm, we found that ulnar joint space area significantly decreased by approximately 25%, the centroid of this area moved an average of 1.3 mm proximally, and the dorsal radioulnar ligament elongated. Despite our previous findings of insignificant changes in the pattern of radioulnar kinematics in patients with malunited fractures, we found significant changes in DRUJ joint area and ligament lengthening. These findings suggest that alterations in joint mechanics and soft tissues may play an important role in the dysfunction associated with these injuries.     

Staged reconstruction for malunited fractures of the distal radius

This prospective study assessed the outcomes of 26 symptomatic malunited distal radial fractures which were treated with an opening wedge corrective osteotomy and bone grafting with rigid fixation. An ulnar shortening osteotomy was subsequently required as a second-stage operation in five cases to restore normal ulnar variance. A wrist arthroscopy was indicated as a third stage procedure with persistent ulnar sided wrist pain in order to address central tears of the triangular fibrocartilage. Satisfactory functional scores were achieved by 20 of the 26 patients after distal radial osteotomy alone and, 24 of the 26 after subsequent ulnar shortening osteotomies and arthroscopy when necessary. The one, two or three stage concept of reconstructing the malunited distal end radius could optimise the outcome rather than using a single-stage strategy.     

不固定下尺桡关节治疗桡骨远端骨折合并下尺桡关节不稳定的病例对照研究

目的：探讨桡骨远端骨折合并下尺桡关节不稳的治疗方式。方法：2007年6月至2009年12月,采取切开复位内固定治疗不稳定型桡骨远端骨折264例,其中42例术中发现合并下尺桡关节不稳,20例采取克氏针固定下尺桡关节或旋后位石膏外固定治疗（固定组）,22例未行固定（非固定组）。术后对握力和腕关节活动范围进行观察;采用Sarmiento改良的Gaaland-WeAey评分系统（GW评分）对腕部功能进行评估,并测试下尺桡关节稳定性。结果：41例患者均获得1年以上随访,所有患者桡骨远端骨折均在术后3个月内获得愈合,下尺桡关节均对合良好,没有出现明显半脱位或脱位。两组患者的握力、腕关节活动范围及GW评分差异无统计学意义（P〉0．05）。l例发生远期下尺桡关节不稳。结论：对桡骨远端骨折合并下尺桡关节不稳定采用锁定钢板固定系统治疗桡骨远端骨折的同时,固定与不固定下尺桡关节临床效果无差异,因此对于合并下尺桡关节不稳的桡骨远端骨折,若桡骨远端骨折能获得满意的解剖复位,不推荐l期固定下尺桡关节。     

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.     

Midcarpal instability caused by malunited fractures of the distal radius

Thirteen patients with malunited fractures of the distal radius developed symptoms of pain and instability of the midcarpal joint. In six cases, a recurrent voluntary midcarpal subluxation was also present during ulnar deviation. These symptoms were first noticed several weeks, and at times several months, after all immobilization for the treatment of the original fracture had been discontinued. We believe that the loss of the normal palmar tilt of the distal articular surface of the radius prepositions the carpus in a dorsal collapse alignment, which enables this instability to develop. Although the instability is localized to the midcarpus , it is treated best, in our opinion, by a corrective osteotomy of the distal radius. In nine patients, osteotomies resulted in relief of preoperative symptoms and correction of midcarpal instability. In one patient, osteotomy of the radius was deemed unnecessary because the loss of palmar tilt of the radius was minimal. Instead the midcarpal ( triquetrohamate ) joint was stabilized by ligament reconstruction. Only transient correction was obtained, with later recurrence of the voluntary midcarpal subluxation.     

青年桡骨远端陈旧性骨折继发下尺桡关节重度脱位的手术治疗

目的 探讨青年桡骨远端陈旧性骨折继发下尺桡关节重度脱位的手术治疗方法.方法 采用短缩尺骨、重建下尺桡关节法,对7例桡骨陈旧性骨折、短缩,下尺桡关节重度脱位患者进行治疗.术后对患者腕关节外形、功能进行随访.结果 所有患者外形恢复良好,功能评价优6例,良1例.结论 短缩尺骨、重建下尺桡关节法是治疗桡骨陈旧性骨折、短缩,下尺桡重度脱位的有效方法.     

Intra-articular distal radius fractures involving the distal radioulnar joint (DRUJ): three dimensional computed tomography-based classification

Purpose

The purpose of this study was to analyze fracture patterns and the magnitude of displacement in the distal radioulnar joint (DRUJ), by three-dimensional (3D) computed tomography (CT), for distal radius fractures with intra-articular displacement of the radiocarpal joint.

Methods

We reconstructed 3D images for 72 consecutive patients with displaced intra-articular distal radius fracture on the basis of fine-cut axial CT data. The fracture patterns involving the DRUJ were classified on the basis of the location and direction of fracture lines, and the extent of fracture comminution. We measured the maximum spatial distance of the gap and the step between the fragments in each 3D image, and the magnitudes of displacement between the groups were compared by analysis of variance followed by post-hoc analysis by use of Tukey’s test.

Results

Sixty wrists had a fracture involving the DRUJ. We classified the 60 wrists into 3 types of fracture pattern. Type 1 was a transverse fracture with minimum displacement. Type 2, in which fracture lines extended into the distal margin of the sigmoid notch, was the most common longitudinal fracture. Type 3 was a fracture with multiple fragments. The step and gap in Type 3 was significantly larger than that in the other types.

Conclusions

Eighty-three percent of intra-articular distal radius fractures had DRUJ involvement, and 28 % of the wrists had multiple fragments. For Type 3 fractures with dorsal or proximal comminution displacement was significantly larger than for simple Type 1 and 2 fractures. Surgical intervention for the DRUJ fragment may be beneficial when there is remarkable intra-articular displacement.     

Acute dislocations of the distal radioulnar joint and distal ulna fractures

This article reviews acute dislocations of the distal radioulnar joint (DRUJ) and distal ulna fractures. Acute dislocations can occur in isolation or in association with a fracture to the distal radius, radial metadiaphysis (Galeazzi fracture), or radial head (Essex-Lopresti injury). Distal ulna fractures may occur in isolation or in combination with a distal radius fracture. Both injury patterns are associated with high energy. Outcomes are predicated on anatomic reduction and restoration of the stability of the DRUJ.     

桡骨远端骨折后下尺桡关节对应关系的变化及临床意义

目的：研究桡骨远端骨折整复后桡骨纵向短缩距离（△h）对下尺桡关节旋转功能的影响。方法：临床60例患者，分别测定每一例患者桡骨远端骨折拆除外固定后桡骨纵向短缩距离△h和下尺桡关节的旋转受限角度γ，△h根据临床测定值分为0mm～、2mm～、4mm～、≥5mm4个区间，γ根据疗效评定标准分为优、良、可、差4个等级。分别计算出在每个区间上的优良可差的例数，并作统计学处理，得出相应的结论。结果：①无尺侧变异组：40例，相关系数r=0．7402，P〈0．0005，2mm～与4mm～组间P〈0．05。②正向变异组：10例，相关系数r=0．7576，0．0005〈P〈0．001，△h在0mm～与2mm～组间P=0．02〈0．05。③负向变异组：10例，相关系数r=0．8242，0．0005〈P〈0．001，△h在4mm～与≥5mm组间P：0．005〈0．01。结论：①无尺侧变异组：桡骨远端骨折整复后短缩距离△h≥4mm时，下尺桡关节旋转功能受限严重，故△h〈4mm。②正向变异组：桡骨远端骨折整复后短缩距离△h≥2mm时，下尺桡关节旋转功能受限严重，故△h〈2mm。③负向变异组：桡骨远端骨折整复后短缩距离△h≥5mm时，下尺桡关节旋转功能受限严重，故△h〈5mm。