Ulnar nerve excursion and strain at the elbow and wrist associated with upper extremity motion

Significant excursion of the ulnar nerve is required for unimpeded upper extremity motion. This study evaluated the excursion necessary to accommodate common motions of daily living and associated strain on the ulnar nerve. The 2 most common sites of nerve entrapment, the cubital tunnel and the entrance of Guyon's canal, were studied. Five fresh-frozen, thawed transthoracic cadaver specimens (10 arms) were dissected and the nerve was exposed at the elbow and wrist only enough to be marked with a microsuture. Excursion was measured with a laser mounted on a Vernier caliper fixed to the bone and aligned in the direction of nerve motion. A Microstrain (Burlington, VT) DVRT strain device was applied to the nerve at both the elbow and wrist. Nerve excursion associated with motion of the shoulder, elbow, wrist, and fingers (measured by goniometer) was measured at the wrist and elbow. An average of 4.9 mm ulnar nerve excursion was required at the elbow to accommodate shoulder motion from 30 degrees to 110 degrees of abduction, and 5.1 mm was needed for elbow motion from 10 degrees to 90 degrees. When the wrist was moved from 60 degrees of extension to 65 degrees of flexion, 13.6 mm excursion of the ulnar nerve was required at the wrist. When all the motions of the wrist, fingers, elbow, and shoulder were combined, 21.9 mm of ulnar nerve excursion was required at the elbow and 23.2 mm at the wrist. Ulnar nerve strain of 15% or greater was experienced at the elbow with elbow flexion and at the wrist with wrist extension and radial deviation. Any factor that limits excursion at these sites could result in repetitive traction of the nerve and possibly play a role in the pathophysiology of cubital tunnel syndrome or ulnar neuropathy at Guyon's canal.     

Arthroscopic capsular release for contracture of the wrist: a new technique.

SUMMARY: Stiffness of the wrist can occur following trauma or surgery. In some patients, loss of motion may be refractory to conservative treatment and operative treatment may thus be indicated. The authors report the results and technique of arthroscopic capsular release of the wrist. A cadaveric study was performed to assess the safety of arthroscopic capsular release. Arthroscopic capsular release was performed on 2 patients with limited wrist mobility. The average distance from the radiocarpal joint capsule to the neurovascular structures were 6.9 mm to the median nerve, 6.7 mm to the ulnar nerve and 5.2 mm to the radial artery. At 6 months follow-up, the average range of motion had improved from 17 degrees flexion and 10 degrees extension to 47 degrees flexion and 50 degrees extension. The average grip strength had improved from 13 to 31 kg. Pain measured on a visual analogue score (0-10) had improved from 1.5 to 1.0. There were no complications. Arthroscopic capsular release of the wrist is a safe and minimally invasive technique that provides good improvement to range of motion.     

Long-term results of silicone wrist arthroplasty in patients with rheumatoid arthritis

PURPOSE: The surgical treatment of the rheumatoid wrist is key in managing the affected hand. Wrist fusion is often the treatment of choice in cases of severe destruction and deformation although most patients would prefer a motion-preserving procedure. The implantation of a wrist prosthesis might be an alternative to partial arthrodesis for selected cases. In this series we analyzed the long-term results (minimum follow-up period, 10 y) of the Swanson silicone spacer for the wrist in patients with rheumatoid arthritis. METHODS: Sixteen patients with rheumatoid arthritis with 18 silicone spacers for the wrists were reviewed after a minimum follow-up period of 10 years (average, 15 y). Subjective evaluation, clinical examination, and radiographic analysis were included. An additional 9 patients (9 wrists) were interviewed by telephone. RESULTS: In 12 of the patients the subjective result was good or very good, mostly because of adequate pain relief. The average range of motion for flexion (average, 28 degrees )/extension (average, 15 degrees ) was 43 degrees with a wide variation within the series. Radiologically all wrists had diminished residual carpal height at follow-up evaluation and 9 of the wrists had evidence of osteolysis and foreign-body granuloma. The initial good correction of the ulnar translation of the wrist was lost partially in the follow-up period (1.1 vs 4.0 mm). Three of the patients needed surgical revision within the follow-up period; all were converted to wrist fusion. CONCLUSIONS: These long-term results suggest that the silicone wrist spacer still may be considered as an alternative to wrist fusion or more complex wrist joint prostheses in patients with rheumatoid arthritis, especially in severe cases and in patients with low demands. In the long term osteolysis caused by foreign-body granulation is to be expected and has to be considered.     

Ulnar impaction syndrome: Managed by wrist arthroscopy

Background:

The development of handicraft industry and increase of various such works that need a large amount of repeated wrist ulnar deviation strength, the incidence of ulnar impaction syndrome (UIS) is increasing, but the traditional simple ulnar shortening osteotomy has more complications. This study aimed to explore the early diagnostic criteria of UIS and its wrist arthroscopic treatment experience.

Materials and Methods:

9 UIS patients were enrolled in this study. According to magnetic resonance imaging, X-ray and endoscopic features, the diagnostic criteria of UIS were summarized and the individualized treatment schedule was made. If the ulnar positive variance was less than 4 mm, the arthroscopic wafer resection was performed. If the ulnar positive variance was more than 4 mm, the arthroscopic resection of injury and degenerative triangular fibrocartilage complex and ulnar osteotomy were conducted.

Results:

In all patients, the wound healed without any complications. All patients returned to normal life and work, with no ulnar wrist pain again. One patient had wrist weakness. There was a significant difference of the wrist activity between the last followup and before operation (P < 0.05). According to the modified wrist function scoring system of Green and O’Brien, there were 6 cases of excellent, 2 cases of good and 1 case of appropriate and the overall excellent and good rate was 92.3%.

Conclusion:

In the treatment of UIS, the arthroscopy can improve the diagnosis rate, optimize the treatment plan, shorten the treatment cycle, with good treatment results.     

Load transfer characteristics of the wrist. Part I. The normal joint

A static positioning frame allows the positioning of unembalmed human upper extremities in any combination of wrist flexion/extension, radio/ulnar deviation, and pronation/supination. Pressure-sensitive film (Fuji) was used to study the contact areas, scaphoid-lunate area ratios, average high pressures, centroid positions, and intercentroid distances of five wrist joints under a uniform load of 103 Newtons (N) in 36 different positions. The contact areas accounted for only 20.6% of the available joint surface. They shift from a primarily palmar location to a primarily dorsal location when the wrist changes from flexion to extension. Overall the scaphoid contact area was 1.47 times that of the lunate and was generally greatest with the wrist in ulnar deviation. The scapho-lunate contact area ratio increased as wrist position changed from radial to ulnar deviation and/or from flexion to extension. For the constant load of 103 Newtons the high pressure averaged 3.17 megapascals (MPa). The scaphoid and lunate high pressure centroids shifted palmar when wrist position changed from 20 degrees of flexion to 20 degrees of extension and then shifted dorsal with further extension of the wrist. The intercentroid distance averaged 14.91 mm and ranged from 10 to 20 mm.     

Effects of wafer resection and hemiresection from the distal ulna on load-sharing at the wrist: a cadaveric study

PURPOSE: Ulnar impaction syndrome is commonly the result of a naturally occurring ulnar-positive condition, distal radius fracture malunion, or collapse of a fractured radial head. The Feldon wafer procedure and the Bowers distal hemiresection procedure are designed to decrease force transmitted through the distal ulna. The purpose of this study was to measure the effects of these procedures on distal ulnar loading with varying degrees of ulnar positivity at the wrist. METHODS: Using a specially designed miniature load cell distal ulnar force was measured in 20 fresh-frozen cadaveric forearms as the wrist was loaded axially to 134 N in neutral forearm rotation; tests were performed in valgus alignment with the elbow flexed to 90 degrees . Ulnar positivity (0 mm, +2 mm, +4 mm, and +6 mm) was created by incremental shortening of the distal radius using a sliding plate. The radial neck was sectioned transversely and the radial head fragment was fixed in its anatomic position using cemented metal prongs connected to a rigid bar; this allowed the radial head to be disconnected and tilted out of the loading pathway to simulate an excised radial head. Loading tests (with and without the radial head in place) were repeated after removal of a 3-mm wafer of bone beneath the triangular fibrocartilage complex, and again after a hemiresection of the distal ulna to the base of the ulnar styloid process. RESULTS: For each ulnar status condition (intact, wafer removal, hemiresection) the mean distal ulnar force generally increased as the wrist became more ulnar positive. Both wafer removal and hemiresection significantly decreased mean distal ulnar forces under all conditions of ulnar variance, with or without the radial head in place. With the radial head in place the mean distal ulnar forces (expressed as a percentage of applied wrist force) for the 0-mm condition were 16.9% (intact), 3.8% (wafer removal), and 3.5% (hemiresection); corresponding values for the +6-mm condition were 61.6% (intact), and 39.8% (wafer removal), 15.1% (hemiresection). With the radial head removed the mean distal ulnar forces for the 0-mm condition were 31.7% (intact), 4.6% (wafer removal), and 4.4% (hemiresection); corresponding values for the +6-mm condition were 96.4% (intact), 71.6%, (wafer removal), and 27.2% (hemiresection). The decrease of distal ulnar force resulting from hemiresection was significantly greater than that for wafer removal for all ulnar-positive conditions; force reductions were not significantly different between the 2 procedures with neutral ulnar variance. CONCLUSIONS: The results of the present study can help to offer a biomechanical basis for choosing between a Feldon wafer procedure and a Bowers hemiresection procedure in patients with ulnocarpal impaction syndrome. Both procedures produced equal decreases of distal ulnar force in the intact forearm. With an ulnar-positive wrist, the condition for which the procedure would be performed commonly, the hemiresection was more effective in decreasing force transmitted through the distal ulna.     

腕投掷运动时腕关节韧带长度变化的活体研究

目的 探讨腕关节在投掷运动过程中腕关节韧带长度的变化.方法 对6例志愿者腕关节进行CT扫描,获取腕关节在投掷运动过程中的5个位置,即桡偏20°背伸60°,桡偏10°背伸30°,中立位,尺偏20°掌屈30°,尺偏40°掌屈60°时各腕骨、尺桡骨远段的三维重建图像,在重建图像基础上利用Mimics软件测得在腕关节投掷运动过程中掌、背侧腕关节韧带的长度.结果 腕关节由中立位至桡偏20°背伸60°时桡舟头韧带、长桡月韧带、尺头韧带、尺三角韧带长度显著伸长,分别延长(3.4±0.5)、(2.0±0.2)、(2.6±0.5)、(2.1±0.4)mm,差异均有统计学意义(P<0.05);腕关节由中立位至尺偏400掌屈60°时背侧桡腕韧带、背侧骨间韧带止于小多角骨部分长度显著伸长,分别延长(1.7 ±0.2)、(3.8 ±0.4)mm,差异有统计学意义(P<0.05).尺月韧带、背侧骨问韧带止于舟骨部分在投掷运动过程中其长度均较中立位时旱增长趋势.结论 腕关节在桡背伸至尺掌屈运动过程中,桡舟头韧带、长桡月韧带、尺头韧带、尺三角韧带缩短,提示张力减低,背侧桡腕韧带、背侧骨间韧带止于小多角骨部分伸长,张力增大,尺月韧带、背侧骨间韧带止于舟骨部分于中立位时张力最小,其变化规律有助于指导临床腕关节韧带损伤的修复.     

腕部X线正位片形态学测量及临床应用

目的 分析测量正常腕部X线正位片形态学参数的正常值,为判断病理状态下这些参数的变化提供依据.方法 采用标准X线摄片技术,利用Pacs系统软件测量40侧正常腕部X线正位片的9个影像学参数,其中包括7个新的影像学参数:尺骨茎突长度(ulnar styloid length,USL)、尺骨小头长度(ulnar head length,UHL)、尺骨小头直径(ulnar head diameter,UHD)、桡骨远端最大宽度(maximal distal radius width,MDRW)、桡骨远端近侧宽度(proximal distal radius width,PDRW)、乙状切迹宽度(sigmoid notch width,SNW)、乙状切迹长度(sigmoid notch length,SNL).同时将这些参数与第三掌骨长度的比值定义为相应指数.结果 40侧正常腕部X线正位片的7个新的影像学参数:尺骨茎突长度平均为[(3.01 ±1.65)mm,-x±s,下同],长度指数平均为(0.05±0.03);尺骨小头长度平均为(9.11±1.54)mm,长度指数平均为(0.15±0.02);尺骨小头直径平均为(18.56±1.96)mm,直径指数平均为(0.30±0.03);桡骨远端最大宽度平均为(29.60±2.70)mm,宽度指数平均为(0.48±0.04);桡骨远端近侧宽度平均为(27.60±2.00)mm,宽度指数平均为(0.45±0.03);背侧缘突起型乙状切迹宽度平均为(3.32±1.61)mm,宽度指数平均为(0.05±0.02),长度平均为(10.15±1.61)mm,长度指数平均为(0.16±0.02);掌侧缘突起型乙状切迹宽度平均为(3.53±1.15)mm,宽度指数平均为(0.06±0.02),长度平均为(10.96±2.33)mm,长度指数平均为(0.18± 0.03);掌背侧缘均无突起型宽度平均为(1.55±1.01)mm,宽度指数平均为(0.03±0.02),长度平均为(10.32±1.57)mm,长度指数平均为(0.17±0.02).结论 测量所得X线正位片参数可用于腕部相关疾病严重程度的判断.     

腕尺桡偏运动时腕韧带长度变化的活体研究

目的 研究腕关节在尺桡偏运动过程中,腕关节韧带长度的变化.方法 对6名志愿者腕关节进行CT扫描,获得腕关节在桡偏20°至尺偏40°内每隔20°的运动范围内各腕骨及尺桡骨远段三维重建图像.男3名,女3名,仅研究单侧右侧腕关节.年龄20～32岁,平均24岁.在腕关节尺桡偏运动过程中,在重建各腕骨及尺桡骨结构图像上以软件测量掌、背侧腕韧带的长度.结果 腕关节尺偏时桡舟头韧带、长桡月韧带、背侧腕间韧带止于舟骨、大多角骨和小多角骨部分的长度较中立位显著伸长,分别伸长(2.4±0.3)mm、(2.3±0.8)mm、(1.2±0.6)mm、(1.2±1.2)mm与(2.6±1.0)mm,差异均有统计学意义(P＜0.05);腕关节桡偏时尺头韧带与背侧桡腕韧带长度显著伸长(P＜0.05),分别为(0.8±0.6)mm和(1.0±0.5)mm.结论 在腕关节尺桡偏运动时,桡舟头韧带、长桡月韧带、背侧腕间韧带于桡偏位缩短,尺头韧带、背侧桡腕韧带长度于尺偏位缩短.这些位置可能使不同腕韧带张力降低,有利于损伤韧带的修复.     

Deformities of the hand and wrist with ulnar deficiency.

Deformities of the hand and wrist in 26 upper limbs of 20 patients with ulnar deficiency were studied. In eight limbs the ulna was totally absent. In the remainder it was severely or moderately hypoplastic. Abnormalities of the digits were present in all affected limbs. There was ectrodactyly in 25 hands. The thumb was hypoplastic in 21 hands and totally absent in five. Digital deformities also included syndactyly (14 hands) and delta phalanx (six hands). Early syndactyly release, pollicization, and rotational osteotomy of the metacarpals improved hand function in many of these patients. In only three of 26 limbs was there more than 20 degrees of fixed ulnar deviation at the wrist. In 16 patients the distal ulnar "anlage" was not removed. None of these patients developed ulnar deviation of the wrist or progressive deformity at the wrist during growth. Resection of the distal ulnar "anlage" does not appear to be warranted, unless there is progressive deformity of the wrist or elbow or increased bowing of the radius.     

Radial nerve excursion and strain at the elbow and wrist associated with upper-extremity motion

PURPOSE: This study evaluated the excursion necessary to accommodate common motions of daily living and associated strain on the radial nerve. The radial nerve was evaluated at the wrist and proximal to the elbow before it bifurcated. METHODS: Five fresh-frozen transthoracic cadaver specimens (10 arms) were dissected; the radial nerve was exposed at the elbow and wrist only enough to be marked with a microsuture. Excursion was measured using a laser mounted on a caliper fixed to the bone and aligned in the direction of nerve motion. Strain was measured with a device applied to the nerve at the elbow. Nerve excursion associated with motion of the shoulder, elbow, wrist, and fingers (measured by a goniometer) was assessed at the wrist and elbow. RESULTS: An average of 4.3 mm of radial nerve excursion was required at the wrist to accommodate wrist motion from 15 degrees of radial deviation to 30 degrees of ulnar deviation and 8.8 mm was needed for elbow motion from 10 degrees to 90 degrees . The radial nerve at the elbow experienced a 28% strain associated with the same motion of flexion and extension at the elbow. When all the motions of the wrist, fingers, elbow, and shoulder were combined 9.4 mm of radial nerve excursion was required at the wrist and 14.2 mm at the elbow. CONCLUSIONS: Any factor that limits excursion at these sites could result in repetitive traction of the nerve and possibly could play a role in the pathophysiology of a mechanical neuropathy, which in the case of the radial nerve most often manifests as pain.     

Functional ranges of motion of the wrist joint

We have examined 40 normal subjects (20 men and 20 women) to determine the ideal range of motion required to perform activities of daily living. The amount of wrist flexion and extension, as well as radial and ulnar deviation, was measured simultaneously by means of a biaxial wrist electrogoniometer. The entire battery of evaluated tasks could be achieved with 60 degrees of extension, 54 degrees of flexion, 40 degrees of ulnar deviation, and 17 degrees of radial deviation, which reflects the maximum wrist motion required for daily activities. The majority of the hand placement and range of motion tasks that were studied in this project could be accomplished with 70 percent of the maximal range of wrist motion. This converts to 40 degrees each of wrist flexion and extension, and 40 degrees of combined radial-ulnar deviation. This study provides normal standards for the functional range of motion of the wrist.     

Load-sharing at the wrist following radial head replacement with a metal implant. A cadaveric study

BACKGROUND: Surgical excision of the radial head is frequently required after a comminuted fracture of the radial head. The outcome of this procedure is often unpredictable, with some patients experiencing ulna-sided pain in the wrist secondary to proximal migration of the radius. Insertion of a radial head prosthesis could prevent proximal radial migration and restore normal load-sharing at the wrist. The thickness of the radial head implant is an important variable in restoring anatomical radial length; however, the effects of varying the length of implants that were used to reconstruct the radius on load-sharing at the wrist have not been studied biomechanically, to our knowledge. METHODS: A miniature load cell was attached to fifteen fresh-frozen cadaveric forearms to record force in the distal part of the ulna as the wrist was axially loaded to 134 N of compression force. Proximal displacement of the radius relative to the capitellum was also recorded. Loading tests on intact forearms were performed with the elbow in valgus and varus alignment and with three positions of wrist rotation (neutral, 45 degrees of pronation, and 45 degrees of supination). Loading tests were then repeated, with the same positions of varus and valgus elbow alignment and wrist rotation as had been used in the tests of the intact forearm, after radial head excision and subsequent insertion of metal radial head implants that restored anatomical length, implants that produced a radial length that was longer than the anatomical length, and implants that produced a radial length that was shorter than the anatomical length. Testing of these different implant thicknesses was repeated after sectioning of the interosseous membrane. RESULTS: The mean distal ulnar forces and mean proximal radial displacements following insertion of an implant that restored anatomical length were not significantly different from the corresponding values for the intact forearm. At neutral wrist rotation, replacing that implant with an implant that increased the radial length by 4 mm (after sectioning of the interosseous membrane) decreased the mean distal ulnar force from 13.4% to 3.3% of the applied wrist force with the elbow in valgus alignment and from 29.1% to 8.6% with the elbow in varus alignment. Replacing the implant that restored anatomical length with one that decreased the length by 4 mm (after sectioning of the interosseous membrane) significantly increased the mean distal ulnar force from 13.4% of the applied wrist load to 33.3% with the elbow in valgus alignment and from 29.1% to 51.6% with it in varus alignment. The mean distal ulnar forces were not significantly affected by the position of wrist rotation when the elbow was in valgus alignment. However, when the elbow was in varus alignment, the mean distal ulnar forces associated with all reconstructed radial lengths were significantly higher when the wrist was placed in 45 degrees of supination. CONCLUSIONS: In this cadaveric model, insertion of a metal implant maintained distal ulnar forces at normal levels, at all three positions of wrist rotation, when the radius had been restored to its original anatomical length. Distal ulnar forces and proximal radial displacements were significantly affected by the reconstructed length of the radius. CLINICAL RELEVANCE: Radial head implants are utilized to prevent proximal migration of the radius as the wrist is loaded; this is especially important when the interosseous membrane has been ruptured and thus cannot help to limit radial displacement. At the time of surgery, comminution and displacement of a radial head fracture may make estimation of the original radial length difficult. Our results demonstrate that, in terms of distal ulnar loading, it is preferable to insert an implant that is too thick rather than too thin.     

Intramedullary K-wire fixation of pediatric forearm fractures and effects on the wrist

This retrospective study evaluated the results of intramedullary Kirschner wire fixation in pediatric forearm fractures and the effects on the wrist. Twenty-seven patients with forearm fractures managed by limited open reduction and intramedullary K-wire fixation were included in this study. Differences in ulnar variance were examined on wrist radiographs. Average ulnar variance was -3.23 +/- 2.14 mm on the operated wrist and -2.30 +/- 2.06 mm on the contralateral wrist (P < .05).     

Modified technique of intramedullary fixation for wrist arthrodesis

Twenty-five normal subjects were studied to assess the possible relation of various wrist postures on grip strengths. Most subjects were found to have the strongest grip strengths in a position of neutral deviation and one half of their maximum extension. A small subpopulation normally postured their clenched fists in slight ulnar deviation rather than in neutral deviation. These patients were strongest in ulnar deviation and one half of their maximum extension. A modification of the wrist arthrodesis technique was developed using intramedullary pin fixation in a series of 10 patients. Fusion was successful in all 10 wrists. This technique retains the advantages of speed and simplicity of previous intramedullary fixation methods and also affords the additional advantage of permitting the wrist to be placed in varying degrees of extension and ulnar deviation.     

Distraction resection arthroplasty of the wrist

Proximal row carpectomy should not be done if wrist degeneration includes cartilage destruction of the capitate or lunate fossa of the radius; yet total wrist arthroplasty has been disappointing for treatment of osteoarthritis. We have used a technique we call distraction resection wrist arthroplasty in such cases. We retrospectively reviewed distraction resection wrist arthroplasty in 14 wrists and compared them to nine patients who had PRC; average follow-up was 32 months. Three patients had spastic contractures and 20 had operation for painful osteoarthritis. Patient satisfaction was high but there were four failures requiring arthrodesis (1 PRC, 3 DRA). Average postoperative wrist motion was 41 degrees of extension, 38 degrees of flexion, 11 degrees of radial deviation, and 13 degrees of ulnar deviation. Static strength averaged almost two thirds of the uninvolved side and dynamic power more than half. Differences between the DRA and PRC patients were not statistically significant in single or aggregate analysis. We believe that distraction technique extends the indications for biologic arthroplasty to patients whose only prior option was wrist arthrodesis.     

Corrective osteotomy for symptomatic increased ulnar tilt of the distal end of the radius

Twelve wrists in 10 patients with a mean age of 23.6 years were treated for symptomatic increased ulnar inclination of the joint surface with corrective osteotomy of the radius. Diagnoses included mild ulnar dysplasia, posttraumatic deformity, Madelung's disease, and multiple hereditary exostosis. All patients had radial-sided wrist pain and an ulnarly displaced arc of radioulnar deviation. Preoperative radiographs showed excessive ulnar inclination of the distal radius, ulnar carpal translation, adaptive carpal malalignment, and frequent distal radioulnar joint incongruency. The patients had decreased pain and improved wrist function at a mean of 5.1 years (range, 2-10 years) after surgery. Average radial deviation changed from 3 degrees to 16 degrees and ulnar deviation from 48 degrees to 29 degrees; flexion/extension and pronosupination remained unchanged. Realignment of the wrist was shown radiographically by a change of ulnar inclination of the radius from 33 degrees to 21 degrees, an increase in scaphoid height from 16.4 to 20.4 mm, and reversal of ulnar carpal translation as shown by an increase in lunate-covering ratio of 64% to 77%. Reduction of the ulnar inclination to normal values by corrective radial osteotomy restores a more physiologic range of motion, decreases symptomatic wrist pain, reverts adaptive carpal changes to normal, increases lunate coverage, and may prevent abnormal cartilage overload in the ulnar compartment of the wrist.     

Motion of the distal radioulnar joint in extension and flexion of the wrist using axial CT imaging of healthy volunteers

BackgroundThe midcarpal joint and the radiocarpal joint contribute to the extension and flexion of the wrist. Little is known about the contribution of the distal radioulnar joint (DRUJ) to the extension and flexion of the wrist. This study evaluated the ulnar motion in extension and flexion of the wrist using computed tomography (CT) imaging.MethodsA total of 30 wrists of healthy volunteers were enrolled. CT images of the axial sections of the DRUJ were obtained with 3 different positions of the wrist: 0° of extension (straight position), maximum active extension, and maximum active flexion. Each wrist motion was performed with 3 different forearm positions: neutral, pronation, and supination. Ulnar position at the DRUJ level was measured and ulnar position with the wrist in straight position was defined as baseline. The ulnar position was recorded as positive value when the position of the ulnar head was volar side and negative value when the position of the ulnar head was dorsal side. The difference from baseline in a position of maximum extension and flexion was evaluated.ResultsIn forearm neutral position and pronation, a value of ulnar position in maximum wrist flexion is significantly negative compared to that in the wrist straight position: the ulnar head moved dorsally from the wrist straight position to wrist flexion. In forearm supination, a value of ulnar position in maximum wrist extension is significantly positive compared to that in the wrist straight position: the ulnar head moved to the volar side from the wrist straight position to wrist extension.ConclusionsThe ulnar head moves during extension and flexion of the wrist. The direction of the ulnar motion was different according to the wrist and forearm position.     

Validation of the extensor carpi ulnaris groove as a predictor for the recognition of standard posteroanterior radiographs of the wrist

This study was designed to establish the extensor carpi ulnaris groove (ECUG) as a reliable radiographic criterion for recognition of true neutral posteroanterior (PA) radiographs and to verify precise measurements of ulnar variance in a large cohort of patients. In 197 patients 197 wrists were evaluated with a series of radiographic views obtained during routine wrist arthrography. Posteroanterior views were taken in all patients at 90 degrees, 45 degrees, and 0 degrees arm abduction and in 171 patients at 90 degrees elbow flexion and 90 degrees arm abduction with full elbow extension. The ECUG position was classified according to its profile with the ulnar styloid as excellent, acceptable, or unacceptable. Ulnar variance was measured on all x-ray films. Statistical analysis included interobserver reliability with 100 x-ray films measured by 2 evaluators. The ECUG was excellent or acceptable in 100% of the x-rays on standard PA views (arm abducted 90 degrees ), 87% excellent or acceptable and 13% unacceptable on 45 degrees arm abduction views, and 23% excellent or acceptable and 77% unacceptable on 0 degrees arm abduction (adducted) views (all with the elbow flexed at 90 degrees ). With the arm at 90 degrees abduction and full elbow extension the ECUG was excellent or acceptable in 91% of cases. These results show that the ECUG is a reliable criterion to verify arm position during PA wrist radiography and therefore provides a standard for making treatment decisions. The need for repeat radiographs should be reduced.     

Arthrodesis of the wrist: past and present

Arthrodesis of the wrist is a well established procedure that may be performed by a variety of techniques. The position of 10 degrees to 30 degrees of extension and 0 degree to 15 degrees of ulnar deviation is the most commonly accepted position for maximum hand function. Van Gemert has written an extensive monograph reviewing the results after wrist arthrodesis. He concluded that only 42% of 66 patients reviewed met all of the following desired criteria: bony union, subjective improvement of pain, improved power of grip and pinch, no loss of function in adjacent joints, and a good ergonomic score by the system that they used. A review of our cases of wrist arthrodesis shows many of the problems noted by Clendenin and Green. Our review also indicates that patients who make occupational transitions to less hand intensive activities have a better response to the procedure.