Influence of distal radioulnar joint subluxation on restricted forearm rotation after distal radius fracture

PURPOSE: To analyze the influence of subluxation of the distal radioulnar joint (DRUJ) on restricted forearm rotation after distal radius fracture. METHODS: Twenty-two cases of healed unilateral distal radial fracture with restricted forearm rotation were included in the study. The subluxation of the DRUJ was evaluated using helical computed tomography scan at neutral, maximum pronation, and maximum supination and presented as the percent displacement of the ulnar head in both the injured and uninjured sides. The radiographic parameters of palmar tilt, radial inclination, dorsal shift, radial shift, and ulnar variance were measured on plain x-ray films and the rotational deformity of the distal radius was evaluated from the computed tomography scan. The differences of each radiographic parameter from the uninjured side were calculated. The relationships between the restricted forearm rotation and the percent displacement of the ulnar head and each of the radiographic parameters were analyzed statistically. RESULTS: When forearm pronation was restricted the ulnar head was located palmarly at neutral, maximum supination, and maximum pronation with severe dorsal tilt of the distal radius. When supination was restricted the ulnar head was located dorsally at maximum supination with severe ulnar-positive variance. CONCLUSIONS: The subluxation of the DRUJ was related to restricted forearm rotation. The radiographic parameters of palmar tilt and ulnar variance showed an adverse influence on the position of the ulnar head at the DRUJ, which might lead to restricted forearm rotation after distal radial fracture.     

Osteoarthritis of the distal interphalangeal joint

Osteoarthritis occurs with the highest prevalence in the distal interphalangeal joint of the hand and has been divided into an erosive and a nonerosive form. The pathogenesis of the early stages of osteoarthritis is poorly understood, but considerable emphasis has been placed on the role of cartilage and subchondral bone as well as soft tissue structures such as collateral ligaments and tendons. Radiographic evaluation represents the most standardized method to quantify disease progression, with different systems having been developed for defining and grading radiographic features. This current concepts article examines the recent knowledge base regarding the etiology, pathogenesis, and evaluation of osteoarthritis of the distal interphalangeal joint.     

骨软骨移植治疗儿童远侧指间关节陈旧性骨折脱位

目的探讨儿童远侧指间关节陈旧性骨折脱位的治疗方法及疗效观察。方法采用游离骨软骨移植术治疗小儿伴有骨软骨缺损的远侧指间关节陈旧性骨折脱位9例9指。结果全部患者均获18个月～13年7个月的随访，优2例，良4例，可3例。结论骨软骨移植术既能有效的矫正畸形，又可保留一定的关节活动度，不失为一种较好的治疗方法。     

Extension block pinning for the treatment of a dorsal fracture dislocation of the distal interphalangeal joint: case report

A relatively rare case of dorsal dislocation of the distal interphalangeal (DIP) joint associated with compression fracture of volar base of the distal phalanx is presented. An extension block pin was used to maintain the reduction of the DIP joint during active flexion and extension exercise after surgery. At 49-month follow-up, the clinical results and radiographic findings were satisfactory.     

Alternative to the distal interphalangeal joint arthrodesis: lateral approach and plate fixation

PURPOSE: Several fixation techniques for distal interphalangeal (DIP) joint arthrodesis have been described, with good clinical results and complication rates between 10% and 20%. We propose an alternative technique and fixation method using a lateral approach and 1.3-mm plate and screws fixation. METHODS: Between March and September 2005, 11 patients, totaling 15 fingers, had DIP joint arthrodesis by the described technique. The indications were posttraumatic arthritis in 8 fingers, degenerative or rheumatoid arthritis in 5 fingers, and isolated flexor digitorum profundus tendon lesions in 2 fingers. Patients were analyzed for osseus union, pain relief, and functional mobility of the finger. RESULTS: Arthrodesis relieved pain and restored stability at the 12th week, on average, with osseous union in all patients. All patients maintained full proximal interphalangeal joint motion with pulp-to-palm distance of zero at 6 months of follow-up evaluation. There were no rotational or angular deformities, nail bed lesions, or skin complications. CONCLUSIONS: The lateral approach with plate and screws fixation is an option for DIP joint arthrodesis. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.     

Combinatorial roles of extrinsic and intrinsic muscles in extension strength of the distal interphalangeal joint

In this study, we observed a combinatorial relationship between intrinsic and extrinsic muscles to extend the distal phalanx via the terminal tendon of the finger extensor. Eleven fresh-frozen human cadaver digit rays were used in these experiments (four index, four middle, three ring digits). All fingers had full joint motion without degenerative diseases. Fingers were individually mounted in a custom built jig fixed by a 1-mm Kirschner wire that was driven into the rotational center of the distal interphalangeal (DIP) and proximal interphalangeal joints. Loads were applied to the extensor digit and dorsal interosseous tendons without flexor tendons, via sutures attached over low-friction pulleys. Extension forces that crossed the DIP joint were measured by a force transducer coupled with a materials-testing machine. We observed a steep inclination of the extensor forces produced by the intrinsic muscles, and there were no significant differences in comparisons among loads (200, 400, 600, and 800 g). The inclination slope increased with an increase of load (p < 0.001). Additionally, the inclinations of the non-linear phases among all finger types were not statistically different. Thus, the contribution between the extrinsic and intrinsic muscles in providing extensor forces to the distal phalanx was similar.     

Use of a headless compressive screw for distal interphalangeal joint arthrodesis in digits: clinical outcome and review of complications

PURPOSE: Arthrodesis of the distal interphalangeal joint (DIPJ) or thumb interphalangeal joints can be necessary to treat pain, deformity, or instability associated with arthritis. Compression and rigid fixation are thought to influence fusion rates and time to union favorably. The purpose of the study was to review the clinical outcome and complications associated with the use of a fully threaded headless compression screw for DIPJ arthrodesis. METHODS: Twenty-seven distal interphalangeal or thumb interphalangeal fusions were performed with an axial Mini-Acutrak screw in 22 patients. Charts, surgical reports, and preoperative and postoperative x-rays were reviewed to determine the incidence, time to union, and complications. The minimal follow-up period was 3 months. RESULTS: Twenty-three of the 27 arthrodeses achieved bony union. Complications included symptomatic nonunion (n=1, treated with secondary fusion), asymptomatic nonunion (n=2, left untreated), infection (n=4; 2 patients required implant removal that resulted in nonunion but declined revision) and nail bed injury (n=3). CONCLUSIONS: The Mini-Acutrak screw technique achieves healing rates that are comparable with but not superior to other techniques. Its main advantages are ease of execution, fully buried hardware, and early mobilization; however, the procedure is associated with complications and meticulous technique is required to avoid them. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic, Level IV.     

A simple fixation method for unstable bony mallet finger

Closed treatment has provided good results in uncomplicated cases of mallet finger; however, surgical fixation is recommended when there is involvement of more than one third of the base of the distal phalanx. Various techniques have been described for this purpose. The goal of this report is to present a simple method of K-wire fixation and show our results with this procedure.     

克氏针外固定支架在治疗近指间关节骨折中的应用

目的 介绍一种克氏针外固定支架治疗近侧指间关节骨折方法.方法 自2006年7月-2009年7月,采用自行设计制作的克氏针外固定支架治疗近侧指间关节骨折9例.其中食指1例,中指3例,环指2例,小指3例;开放性骨折5例,闭合性骨折4例;单纯性骨折6例,粉碎性骨折3例.受伤至治疗时间为2h～8d,平均2d.随访5～36个月,平均13个月.手部功能恢复按TAM标准评价.结果 骨折全部愈合,按TAM标准评价：优5例,良2例,可2例,优良率77.8%.结论 克氏针外固定支架能够对近侧指间关节骨折起到良好的固定作用,而且其结构简单,方便实用,价格低廉.     

Dimensional analysis of the distal phalanx with consideration of distal interphalangeal joint arthrodesis using a headless compression screw

Background

Headless compression screws have been used for arthrodesis of the distal interphalangeal joint with good clinical results. However, some distal phalanges are too small, thus precluding their use, or increasing complication rates.

Methods

In order to validate our digital measurements, radiographs of five cadaveric hands were obtained. The distal phalanges of these fingers were measured using our institution’s digital radiograph software. The cadavers were then dissected, and the actual phalanges were measured to confirm the accuracy of the digital measurements; 200 consecutive hand radiographs were then measured to obtain average width and heights of the narrowest measurements of the distal phalanx of each finger. Subgroup analysis of each finger for age and gender was completed.

Results and Conclusions

Females were routinely smaller than their male counterparts. No age-related differences were seen. A substantial number of fingers were found to be too small to allow for use of headless compression screws; 42 % of small finger distal phalanges are too small to accommodate 2.8-mm threads, and that number increases to 81 % with 3.2-mm threads and 97 % with 3.5-mm threads. Few distal phalanges, regardless of which finger, are large enough to accommodate 3.5-mm-diameter threads; 22% of female ring finger distal phalanges are smaller than 2.8 mm, and 66 % of ring fingers are smaller than 3.2 mm. Based on our measurements, a surprising number of distal phalanges are smaller than the trailing thread diameter of commonly commercially available headless screws. Care must be taken in selecting implants for distal interphalangeal (DIP) fusion.     

桡骨远端骨折成角改变对桡腕关节影响的生物力学研究

目的:研究桡骨远端骨折后掌倾角及尺偏角改变对桡腕关节的影响.方法:12只成人上肢标本于距关节面3cm处截骨去除1cm骨块,制作桡骨远端骨折成角畸形模型.利用压敏片测试桡腕关节面的应力分布和受力面积改变情况.结果:随着桡腕关节面背倾加大,舟骨和月骨接触面向关节面背侧移位,随着背倾角度和桡偏角度的加大,舟骨的接触面积、接触应力显著减少(P＜0.01),月骨的接触面积、接触应力显著增大(P＜0.01).结论:桡腕关节面背倾10°以上时,桡偏10°以上时,舟骨和月骨的接触面积及接触应力有显著变化,影响腕关节功能.