MRI follow-up of pisiform bone transposition for treatment of lunatomalacia

 Objective. Transposition of the pisiform bone is an operative treatment for lunatomalacia. The postoperative viability of the transposed pisiform bone is difficult to assess. The purpose of the study was to evaluate the utility of MRI for postoperative assessment of viability of the pisiform and lunate bones. Design and patients. Six patients who underwent transposition of the pisiform for treatment of lunatomalacia, were assessed pre- and postoperatively with conventional radiographs (including tomography), CT and MRI. Results. Conventional radiographs, conventional tomograms and CT were all useful in demonstrating the location of the transposed pisiform. CT showed the transposed pisiform without superposition. However, neither CT nor conventional techniques provided information regarding viability of the pisiform. In all patients investigated in the first year following surgery, T1-weighted MR images showed high signal intensity in the transposed bones. In all patients investigated after 1 year, the signal intensity decreased to an intermediate level on T1-weighted images. Enhancement following contrast medium administration in the transposed pisiform and the lunate was noted in all patients, indicative of viability. Conclusion. Contrast-enhanced MRI is able to provide important information regarding the viability of the transposed pisiform and the remaining parts of the lunate. Thus, contrast-enhanced MRI provides an improved means of postoperative assessment regarding short-term follow-up following pisiform transposition. In the long-term follow-up conventional radiography and CT may be equal to MRI in showing increasing sclerosis and/or fragmentation.     

Kienbock's disease: A radiological case report

Kienböck''s disease is a condition characterized by avascular necrosis of the lunate. It is also known as lunatomalacia and aseptic or ischemic necrosis of the lunate.The aim of this work is to summarize and illustrate, through a case diagnosed in our institution, the radiological aspects of this rare entity, which occupy a prominent place in the diagnosis.A better understanding of this recently described nosological entity and a wide dissemination of its diagnostic criteria, especially by radiologists, should facilitate the diagnosis and treatment of patients.     

Arthrosis of the lunate-capitate joint

Arthrosis of the lunate-capitate (LC) joint was investigated in 44 wrists from 36 patients. The symptomatology was uncharacteristic and most patients were examined because of pain, swelling or decreased function of the wrist. The LC arthrosis seemed to be secondary to trauma in most patients; 26 wrists had an increased distance between the lunate and scaphoid, indicating a rotatory luxation of the scaphoid; 5 had fracture of the scaphoid with pseudarthrosis; one had a radius fracture healed with volar and ulnar compression and 2 had penetrating trauma to the LC joint. The arthrosis was secondary to pathologic changes in the lunate in 3 patients; lunatomalacia in 2 and a cyst fracturing into the LC joint in one. In 7 wrists arthrosis was found in several carpal joints and the LC arthrosis was one of these.     

Carpal ligamentous disruptions and negative ulnar variance

Negative ulnar variance is a condition in which the ulna is relatively shorter than the radius at the carpus. It was found in 21% of 203 normal wrists. We have observed an increased incidence (49%) of this anomaly in patients with carpal ligamentous instabilities (dorsiflexion instability, palmar flexion instability, scapholunate dissociation with rotary luxation of the scaphoid, and lunate and perilunate dislocations). While the reasons for this association have yet to be adequately delineated, the presence of a negative ulnar variant may serve as an impartial clue to the presence of ligamentous instability. Many carpal instabilities present with subtle radiographic findings requiring careful evaluation of radiographs. Patients with negative ulnar variance and histories suggestive of ligamentous instability should undergo careful radiologic evaluation to assure early diagnosis of carpal disruption.     

Assessment of ulnar variance: a radiological investigation in a Dutch population

OBJECTIVE: A radiological study was performed to evaluate ulnar variance in 68 Dutch patients using an electronic digitizer compared with Palmer's concentric circle method. Using the digitizer method only, the effect of different wrist positions and grip on ulnar variance was then investigated. Finally the distribution of ulnar variance in the selected patients was investigated also using the digitizer method. DESIGN AND PATIENTS: All radiographs were performed with the wrist in a standard zero-rotation position (posteroanterior) and in supination (anteroposterior). Palmer's concentric circle method and an electronic digitizer connected to a personal computer were used to measure ulnar variance. The digitizer consists of a Plexiglas plate with an electronically activated grid beneath it. A radiograph is placed on the plate and a cursor activates a point on the grid. Three plots are marked on the radius and one plot on the most distal part of the ulnar head. The digitizer then determines the difference between a radius passing through the radius plots and the ulnar plot. RESULTS AND CONCLUSIONS: Using the concentric circle method we found an ulna plus predominance, but an ulna minus predominance when using the digitizer method. Overall the ulnar variance distribution for Palmer's method was 41.9% ulna plus, 25.7% neutral and 32.4% ulna minus variance, and for the digitizer method was 40.4% ulna plus, 1.5% neutral and 58.1% ulna minus. The percentage ulnar variance greater than 1 mm on standard radiographs increased from 23% to 58% using the digitizer, with maximum grip, clearly demonstrating the (dynamic) effect of grip on ulnar variance. This almost threefold increase was found to be a significant difference. Significant differences were found between ulnar variance when different wrist positions were compared.     

Lunate chondromalacia: evaluation of routine MRI sequences

OBJECTIVE: Chondromalacia is a commonly encountered abnormality at arthroscopy and may be responsible for significant clinical symptoms and disability. In the wrist, the most common location for chondromalacia is the lunate bone. Consequently, we sought to study the accuracy of clinical MRI in the assessment of lunate articular cartilage. MATERIALS AND METHODS: MR images of 34 patients who underwent arthroscopy and had an MRI examination within 1 month of surgery were evaluated by two reviewers for the presence and location of lunate cartilage defects and subchondral edema. RESULTS: Lunate cartilage defects were seen on MRI in 10 of the 13 patients with chondromalacia, but these defects were also incorrectly noted in three of 21 of patients without chondromalacia. The visible locations for cartilage defects were the ulnar aspect of the proximal lunate bone (n = 3), radial aspect of the proximal lunate bone (n = 4), ulnar aspect of the distal lunate bone (n = 2), and radial aspect of the distal lunate bone (n = 1). Subchondral marrow edema was observed in six of the 10 patients with chondromalacia seen on MRI; in all six patients, the edema was seen in the same quadrant as the cartilage defect. Marrow edema was detected in one patient without chondromalacia. CONCLUSION: We conclude that lunate chondromalacia can be accurately assessed using routine MRI sequences, although there are occasional false-positive interpretations.     

MR imaging of ulnar impaction

The ulnar impaction syndrome of the wrist is a well-recognized clinical entity, usually showing distinct radiographic features including a positive ulnar variance and degenerative subchondral changes of the distal ulna, proximal lunate, and proximal triquetrum. Confirmation of the clinical and plain film findings with advanced imaging is often necessary to exclude other entities with a similar clinical presentation. Although arthrography and bone scintigraphy are helpful in this work-up, magnetic resonance imaging (MRI) appears to be both a sensitive and a specific means of evaluation. The imaging studies in four patients with clinically and surgically diagnosed ulnar impaction are described, with emphasis on MRI findings. MRI appears to be the modality of choice in the evaluation of patients with suspected ulnolunate impingement.     

MR imaging of the type II lunate bone: frequency, extent, and associated findings.

OBJECTIVE: Type II lunate bones have an "extra" facet that articulates with the hamate bone, which frequently leads to arthritis. Because the only prior studies, to our knowledge, on this common and clinically significant variant involved dissection of cadavers, we performed an MR imaging study of the type II lunate. MATERIALS AND METHODS: We retrospectively reviewed MR images obtained at 1.5 T of 186 wrists for frequency of type II lunates, size of the extra facet, amount of hamatolunate apposition, and presence of hamate subchondral edema. Of the 186 wrists, 28 also had correlation with findings on wrist arthroscopy. RESULTS: One hundred seven wrists (57.5%) had type II lunates with an average extra facet size of 4.6 mm (range, 1.2-12.0 mm). Apposition (articulation) of the extra lunate facet with the hamate averaged 77.4% (range, 0-100%). Hamate edema was seen in only nine wrists (4.8%), all of which had type II lunates. Arthroscopic evidence of focal hamate chondromalacia and MR imaging evidence of marrow edema were seen in six of these nine wrists; marrow edema was seen only in wrists with frank cartilage changes on arthroscopy. CONCLUSION: An extra facet (type II lunate) was seen in approximately half of 186 wrists. On MR imaging, type II lunates usually have an innocuous appearance. A large percentage of patients with type II lunates also have chondromalacia, which often is occult on MR imaging. When visible, such chondromalacia is the cause of marrow edema similar to that seen in patients with carpal fractures.     

Kienb?ck's disease. Current data]

Aseptic osteonecrosis of the lunate bone is a rare disease of unknown aetiology. The mechanical theory of shearing of the lunate underneath the radius is generally accepted, especially in the presence of a short ulna, even if it is insufficient. The diagnosis is exclusively radiographic and requires, in the early stages, the use of MRI which is more sensitive and specific than bone scan. Plain X-rays allow the disease to be classified into various stages, which determine the therapeutic indications. Many treatments have been proposed, but the follow-up is often inadequate. Simple immobilization is atraumatic, but its efficacy is highly controversial. Equalization of the two bones, usually by shortening the radius, is the most widely used technique and, with a follow-up of more than 20 years, appears to be effective in 80% of subjects. Revascularization of the lunate has been proposed in the early forms. Partial arthrodeses are indicated in the advanced forms. Radio-carpal arthrodesis or denervation of the wrist are indicated in the presence of osteoarthritis. Functional sequelae are frequent in these young subjects, who are often manual workers.     

The hamatolunate facet: characterization and association with cartilage lesions--magnetic resonance arthrography and anatomic correlation in cadaveric wrists

The objective of this study was to characterize the appearance of the hamatolunate facet using high-resolution magnetic resonance (MR) arthrography in cadavers and to correlate the presence of this anatomic variant with the presence of osteoarthritis in the wrist. High-resolution MR images of 22 cadaveric wrist specimens were obtained after tri-compartmental arthrography. Two readers in consensus analyzed the MR images and recoded the presence or absence of a hamatolunate facet. Geometric characteristics and cartilage and ligament integrity were analyzed. A third reader, who was blinded to the purpose of the study, recorded cartilage lesions of all the bones of the proximal and distal carpal rows. A hamatolunate facet was present in 11 of 22 wrists (50%). The mean coronal size of the lunate facet at the lunate (type II lunate) was 4.5 mm (range, 2-6 mm). The highest frequencies of cartilage lesions were seen in the scapho-trapezio-trapezoid joint (45.5%) and at the proximal pole of the hamate (54.4% and 40.9% for consensus reading/blinded reading, respectively). In cases with a hamatolunate facet, the frequency of cartilage lesions in the proximal pole of the hamate was 81.8% and 63.6% versus 27.3% and 18.2% without such a facet (chi-squared, P=0.01/ P=0.03). No correlation of the presence of a hamatolunate facet with interosseous ligament tears or lesions of the triangular fibrocartilage was seen. In conclusion, the hamatolunate facet is a very common anatomic variant. The presence of a hamatolunate facet is associated with cartilage damage in the proximal pole of the hamate.     

High-resolution bone scintigraphy of the adult wrist.

Bony anatomic landmarks of the wrist (e.g., pisiform, hook of hamate, radioulnar joint, and styloid processes of the radius and ulna) were routinely identified in 28 adult patients examined for wrist pain. With the wrists prone and immobilized, bone scintigrams were obtained for 500,000 counts with an asymmetric (133 to 161 keV) Tc-99m energy window and either a converging (best choice) or straight-bore, high-resolution collimator. High-resolution scintigraphy precisely localized degenerative joint disease (nine patients), scaphoid fractures (five), pisiform fracture (one), lunate avascular necrosis (one), radioulnar arthritis (one), septic or inflammatory arthritis (six), ulnocarpal impingement (two), and reflex sympathetic dystrophy syndrome (two). Images obtained palm down with the wrist in ulnar deviation helped identify increased uptake within the scaphoid. Fracture and significant bone or joint disease were excluded in one patient.     

MRI in the diagnosis of cartilage injury in the wrist

OBJECTIVE: Our purpose was to evaluate the accuracy of MRI in identifying articular cartilage abnormalities in the distal radius, scaphoid, lunate, and triquetrum of patients with wrist pain. MATERIALS AND METHODS: Eighty-six MRI examinations of the wrist in 85 patients (41 indirect MR arthrograms and 45 unenhanced [nonarthrographic] MR images) were evaluated. The study population consisted of 47 male (54.7%) and 38 female (45.3%) patients with an average age of 37.5 years (range, 7-62 years). Three experienced musculoskeletal radiologists who were unaware of surgical findings retrospectively evaluated the MRI examinations for cartilage abnormalities in the distal radius, scaphoid, lunate, and triquetrum. All patients underwent arthroscopy of the radiocarpal joint with inspection of the articular surfaces of the distal radius, scaphoid, lunate, and triquetrum. The articular cartilage was evaluated on the basis of the 5-point scale of the Outerbridge classification system. RESULTS: When at least two of the three radiologists had concordant interpretations, sensitivity for abnormalities in the distal radius was 27%; the scaphoid, 31%; the lunate, 41%; and the triquetrum, 18%. Specificity for the distal radius was 91%; the scaphoid, 90%; the lunate, 75%; and the triquetrum, 93%. Weighted kappa values among the three observers showed only fair agreement (0.279-0.360). High-grade more extensive cartilage lesions were no more accurately identified than low-grade lesions. Indirect MR arthrograms were not statistically more sensitive, specific, or accurate than unenhanced studies. No bone was more frequently or less frequently graded correctly or incorrectly with statistical significance. The variables of sex, age, and the presence of multiple bones with lesions did not affect accuracy. CONCLUSION: Our findings suggest that MRI of the wrist with the techniques described is not adequately sensitive or accurate for diagnosing cartilage defects in the distal radius, scaphoid, lunate, or triquetrum.     

Demonstration of the scapholunate space with radiography

The importance of radiographic evaluation of the scapholunate space, which should not be wider than 2 mm, has been well established in cases of wrist injury. Unfortunately, the assessment of this space is not accurately determined with routine posteroanterior (PA) radiographs, because the scaphoid and lunate bones often overlap. Moreover, the exact portion of the scapholunate space that should be measured has never been clearly defined. Nine wrists with a scapholunate space no wider than 2 mm and without chondrocalcinosis were studied by means of plain routine views and special projections, transaxial and coronal computed tomographic scans, and dissection to determine the precise orientation and anatomy of this space. A PA radiograph with 10 degrees of tube angulation from the ulna toward the radius best demonstrated the scapholunate space. This space should be measured at the level of the midportion of the flat lateral facet of the scaphoid.     

Capitate-lunate instability: recognition by manipulation under fluoroscopy

Videotape fluoroscopy was used to diagnose a previously undescribed carpal dissociation, the capitate lunate instability pattern. In eight patients with midcarpal pain and clicking, the examiner simultaneously applied pressure to the scaphoid tuberosity while applying longitudinal traction and flexion to the wrist under fluoroscopic control. This maneuver revealed dorsal subluxation of the proximal carpal row and capitate lunate subluxation in each of the eight patients. Plain radiography and arthrography were not helpful in the diagnosis. All eight cases were managed conservatively. Videotape fluoroscopy is the best radiologic method of diagnosing capitate-lunate instability.     

深低温冷冻同种异体月骨移植临床应用6例报告

目的　研究深低温冷冻同种异体月骨移植治疗月骨无菌性坏死的临床疗效。方法　应用深低温冷冻同种异体月骨移植治疗月骨无菌性坏死 6例 ,随访 10年以上。结果　 6例患者切口一期愈合 ,术后无明显排异反应及手术并发症。随访 10年以上 ,摄X线片显示月骨轮廓清晰 ,大小正常 ,骨小梁排列整齐 ,整个月骨密度均匀一致无明显脱钙 ,腕关节活动无疼痛 ,活动范围屈和 (或 )伸 3 0～ 0～ 2 5°能完成日常劳动 ,病人关节功能恢复满意。结论　深低温冷冻同种异体月骨移植治疗月骨无菌性坏死疗效满意。     

Imaging findings in ulnar-sided wrist impaction syndromes.

Impaction syndromes related to ulnar-sided pain include ulnar impaction syndrome, ulnar impingement syndrome, ulnocarpal impaction syndrome secondary to nonunion of the ulnar styloid process, ulnar styloid impaction syndrome, and hamatolunate impingement syndrome. The most common of these, ulnar impaction syndrome, is a degenerative condition of the ulnar side of the wrist related to excessive load bearing across the ulnar carpus, triangular fibrocartilage (TFC) complex, and ulnar head. In an adequate clinical setting, characteristic osseous findings at radiography include positive ulnar variance in ulnar impaction syndrome, a short ulna in ulnar impingement syndrome, nonunion of the ulnar styloid process in ulnar impaction syndrome secondary to ulnar styloid nonunion, an excessively long ulnar styloid process in ulnar styloid impaction syndrome, and type II lunate bone in hamatolunate impingement syndrome. Nevertheless, confirmation of clinical and conventional radiographic findings with magnetic resonance (MR) imaging is often necessary to exclude other entities with similar clinical manifestations. MR imaging allows earlier detection of an abnormality in the TFC complex, cartilage, or bone marrow of carpal bones and is helpful in formulating the extensive differential diagnosis in patients with ulnar wrist pain and limitation of motion.     

Inflammatory arthritis-like and other MR findings in wrists of asymptomatic subjects

Objective To describe magnetic resonance (MR) imaging findings in the wrists of asymptomatic subjects that might be confused with pathologic findings.Design MR examination of the dominant wrist was performed in 30 asymptomatic volunteers aged 22–49 years using pre-contrast and post-contrast sequences in the coronal and axial planes. The bases of the metacarpals, the carpus and the distal radius and ulna were evaluated by two musculoskeletal radiologists for lesions, notches, blood vessels and synovial enhancement.Results There were 24 bright osseous lesions (erosions, intraosseous ganglia, oedema or cysts) in 14 subjects. Intraosseous blood vessels were seen in all but one wrist examined, most commonly in the capitate and lunate bones. Enhancement was present in 26 of 27 notches identified at the base of the second metacarpal and less commonly in the capitate, hamate and triquetral notches. A small joint effusion was present in 14 subjects. Joint or soft-tissue enhancement was identified in 16 wrists.Conclusions Many MR abnormalities and variants may be detected in the wrists of asymptomatic subjects. Many of these could be confused with pathologic findings usually associated with inflammatory arthritis.Partial funding provided by the Royal Australian and New Zealand College of Radiologists College Research Fund.     

Three-phase bone scintigraphy of Kienb?ck disease]

Thirty-three joints in 31 patients of Kienb?ck disease were evaluated with three-phase bone scintigraphy. Follow-up studies were performed in 19 cases of them. The patients with increased ulnar blood flow on arterial phase and ample perfusion on venous phase in angiograms showed good clinical prognosis. This ample ulnar blood flow and perfusion might be essential for the recovery of this disease. Although staging was possible using static images alone, blood pool images provided more information about the present condition of lesions, such as hyperemic state and remodeling reactions. Blood pool image was indispensable for staging and analyzing lesions and evaluating post-operative course. Increased lunate perfusion in venous phase of angiograms and localized lunate uptake in blood pool images were the favorable signs, which were shown in most cases with good prognosis. It is concluded that three-phase bone scintigraphy gives useful informations for evaluating Kienb?ck disease which can not be obtained by conventional bone scintigraphy.     

MSCT在腕关节外伤中的应用

目的:探讨MSCT在腕关节外伤中的应用价值。方法:连续收集本科室2008年1月~12月因外伤进行腕关节MSCT检查的病例共计34例。MSCT扫描采用16层螺旋CT扫描仪(Siemens Somatom Sensation 16)。扫描及重建参数:120kV,120mAs,准直器宽度0.75mm,螺距0.55,1.0mm重建层厚、0.5mm重建间距,采用高分辨骨算法重建。重建的薄层图像传至Siemens多功能后处理工作站(MMWP)进行图像后处理。评价各种后处理技术对腕关节外伤的诊断价值。结果:在34例腕关节外伤中,共发现骨折40处。以舟状骨的骨折最多见,共计14处,月骨骨折3处,三角骨骨折3处,大多角骨骨折2处,小多角骨骨折1处,头骨骨折1处,钩骨骨折2处,尺桡骨远端骨折7处,掌骨基底部骨折7处。上述部分骨折伴有月骨脱位、月骨周围脱位等。薄层多平面重组(MPR)图像能清晰显示细微的骨折和骨折脱位的方向;曲面重组(CPR)图像可以在一幅图像上显示不同平面的结构和骨折;容积重建(VR)图像可以清晰显示复杂骨折脱位时各腕骨间的空间关系。结论:MSCT的各种重建和重组技术能清晰显示腕关节外伤的各种骨折和脱位,在腕关节外伤的临床诊断中有较大应用价值。     

Computed tomography of wrist trauma

We devised a rapid and sensitive computed tomography (CT) method to assess the acutely injured wrist, healing carpal fractures and post-traumatic osteonecrosis, when the plain films offer insufficient information. The wrist is positioned in a simple reverse-L-shaped Perspex immobilizer. With the scaphoid as the center of the arc and the long axis of the distal radius as the reference 0 degrees line, sequential coronal scans of the wrist were done in 10 degrees increments in an arc of 40 degrees to give 0 degrees, 10 degrees, 20 degrees, 30 degrees and 40 degrees scans. The 0 degrees and 10 degrees arc scans were best for evaluating the distal radius and ulna and soft tissues, the 10 degrees and 20 degrees scans for the carpal bones other than the scaphoid, and their relation to each other, the 30 degrees and 40 degrees scans, parallel to the long axis of the scaphoid, for fractures of the scaphoid and the hook of the hamate. In addition the 40 degrees scan offered an excellent carpal tunnel view. In 22 patients examined for wrist trauma CT was found to be more accurate than plain films and plain-film tomography in determining the presence of a fracture (4 scaphoid and 1 distal radius), in assessing the degree of osseous union (12) and in evaluating intercarpal fusion (2). In addition CT detected avascular necrosis of the lunate in two patients and erosions of the scaphoid and distal radius attributed to rheumatoid arthritis in one.