Correlation of histopathology with magnetic resonance imaging in Kienböck disease

Simplifying the Decision-Making Process in the Treatment of Kienböck's Disease

Background  In recent years, the classification and treatment algorithm for adult Kienböck's disease (KD) has expanded. However, the priority of the investigations done in determining its management has not been discussed, as not every patient with KD requires magnetic resonance imaging (MRI) or wrist arthroscopy. Materials and Methods  We discuss the role of these investigations and emphasize the importance of computed tomography (CT) imaging in evaluating the cortical integrity of the lunate and its role in the decision-making process and management of KD. Results  We put forward an investigative algorithm that places into context the investigative roles of MRI, arthroscopy, and CT. Conclusion  KD is a rare condition, and there is a lack of comparative studies to help us choose the preferred treatment. The decision on the management options in adult KD may be made by determining the integrity of the lunate cortex and deciding whether the lunate is salvageable or not by CT scan. MRI may provide useful information on the vascular status if the lunate cortex is intact, and the lunate is salvageable. If the lunate is fragmented, it is not salvageable, and MRI does not provide useful information. Arthroscopy has a role in selective cases.

Analyzing Chronological Change in Postoperative Magnetic Resonance Imaging Results in Patients With Kienböck’s Disease by Using an Original Grading System

Background and objective

Signal changes in MRI for Kienböck’s disease have only been qualitatively assessed so far. In light of this, we proposed a new grading system for quantitative analysis with an ordinal scale.

Methods

The study included 31 patients (17 men, 14 women) with Kienböck's disease. By referring to Nakamura’s MRI grading system, we devised a grading system with five grades (Grades 1-5) using proton density-weighted (PDW) coronal images with respect to the signal intensity of the lunate. All cases were examined by using the MRI grading system by three hand surgeons, both preoperatively and postoperatively. We evaluated the inter-rater reliability of our grading system by using the interclass correlation coefficient. After surgery, we implemented annual MRI evaluation for as long as possible and quantitatively assessed changes in MRI grades. We also investigated the correlation between postoperative MRI grades, Mayo Wrist Scores (MWS), and age at the surgery by using Pearson’s coefficient.

Results

The MRI evaluation was performed 2-15 years after surgery. The reliability of our grading system was high; inter-rater interclass correlation coefficients were 0.783 (examiners 1-2), 0.780 (examiners 1-3), and 0.825 (examiners 2-3), representing a substantial agreement. The correlation coefficient between the MRI grade and MWS was -0.31, suggesting a mild negative correlation; postoperative MRI grade also correlated with age at surgery (Pearson’s coefficient: 0.447).

Conclusions

Our proposed MRI grading system has high reliability and could be used to assess the regeneration of a necrotic lunate for quantitative analysis on an ordinal scale. Improvements were observed one to four years postoperatively, demonstrating a mild correlation with the clinical results.

Matching Kienböck's Treatment Options to Specific Features of Each Case

Kienböck's disease is best understood as a continuous interaction between compromised perfusion and structural deterioration that transitions from an early phase to a late phase. Existing literature has failed to identify any one superior treatment for Kienböck's; many studies even demonstrate no advantage for surgery compared with the natural history. Surgical interventions for early and transitional Kienböck's are designed to preserve or reconstruct the lunate. However, in most studies, the only tool used to assess the lunate itself has been plain radiography that neither reveals critical architectural details (demonstrated by computed tomographic scan) nor the vascular status (demonstrated by magnetic resonance imaging). Most articles, therefore, do not adequately define the preoperative status of the lunate or its alteration through surgical intervention. Critical preoperative features that are best demonstrated by these advanced imaging studies have specific anatomic and physiologic relationships that better correspond with certain surgical interventions, which also pair better with specific patient characteristics. This review explains how to identify, analyze, and strategically match these variables with the treatment interventions available for Kienböck's patients through the early, transitional, and late phases of the disease.

Idiopathic Avascular Necrosis of Trapezoid in Adolescence: 3-Year Follow-Up

Avascular necrosis (AVN) is relatively uncommon in the carpal bones, although it most frequently involves the lunate and scaphoid. The trapezoid has abundant vascular channels from a rich network of dorsal and palmar vessels, and only a few cases of AVN have been reported in adults who sustained a traumatic insult. We present a rare case of idiopathic AVN of the trapezoid in an adolescent presenting with refractory pain at the second metacarpal base. Over a period of 36 months, follow-up symptom evaluations and serial magnetic resonance images showed prominent gradual improvement, consistent with spontaneous resolution.

Increased perfusion in dynamic gadolinium-enhanced MRI correlates with areas of bone repair and of bone necrosis in patients with Kienböck's disease

BACKGROUND

Osteonecrosis of the lunate, Kienböck's disease, can lead to fragmentation of the lunate, carpal collapse, and severe osteoarthritis. Since the etiology of Kienböck's disease is impaired circulation, a diagnostic method capable of assessing perfusion would be valuable. Recent studies have suggested that dynamic contrast-enhanced (DCE) MR examinations at 3 T can assess perfusion in healthy carpal bones.

PURPOSE

To evaluate the use of DCE-MR for assessing perfusion in the lunate bone in patients with Kienböck's disease. Furthermore, to compare perfusion with histopathology with a focus on bone viability.

STUDY TYPE

Prospective case-control study.

POPULATION

Fourteen patients with Kienböck's disease and a control group of 19 healthy subjects. Field Strength: 3 T with T₁ -weighted fat-saturated contrast-enhanced gradient echo series.

ASSESSMENT

Features of the enhancement curves from the DCE-MR examinations, time to peak (TTP), maximum slope (MS), and maximum enhancement (ME) assessed by a radiologist. Six of 14 patients were surgerized with lunate excision, allowing comparison between features of the enhancement curves and histopathology.

STATISTICAL TESTS

Mann-Whitney U-test. P < 0.05 was considered a statistically significant difference.

RESULTS

Patients with Kienböck's disease showed significantly higher and faster perfusion parameters compared with the control group, the mean value of the TTP in patients was 126.73 sec, in controls 189.79 sec (P = 0.024), ME in patients 173.55 AU, in controls 28.46 AU (P < 0.001), and MS in patients 5.04 AU, in controls 1.06 AU (P < 0.001). When compared with histopathology, increased perfusion was seen in areas of bone formation but also in necrosis. Areas of normal bone showed low perfusion.

DATA CONCLUSION

DCE-MRI at 3 T can diagnose altered perfusion in patients with Kienböck's disease. Increased perfusion cannot definitely be used as a marker of bone viability.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2019;50:481-489.

Interobserver Agreement in Diagnosing Early-Stage Kienböck Disease on Radiographs and Magnetic Resonance Imaging

BACKGROUND

The appearance of early Kienböck disease on radiographs and magnetic resonance imaging (MRI) may be difficult to distinguish from other conditions that affect the lunate. We aimed to assess the interobserver agreement in the diagnosis of early Kienböck disease when evaluated on different imaging modalities.

METHODS

Forty-three hand surgeon members of the Science of Variation Group were randomized to evaluate radiographs and 35 hand surgeons to evaluate radiographs and MRI scans of 26 patients for the presence of Kienböck disease, the lunate type, and the ulnar variance. We used Fleiss' kappa analysis to assess the interobserver agreement for categorical variables and compared the κ values between the 2 groups.

RESULTS

We found that agreement on the diagnosis of early Kienböck disease was fair (κ, 0.36) among observers who evaluated radiographs alone and moderate (κ, 0.58) among observers who evaluated MRI scans in addition to radiographs, and that the difference in κ values was not statistically significant ( P = .057). Agreement did not differ between observers based on imaging modality with regard to the assessment of the lunate type ( P = .75) and ulnar variance ( P = .15).

CONCLUSIONS

We found, with the numbers evaluated, a notable but nonsignificant difference in agreement in favor of observers who evaluated MRI scans in addition to radiographs compared with radiographs alone. Surgeons should be aware that the diagnosis of Kienböck disease in the precollapse stages is not well defined, as evidenced by the substantial interobserver variability.

J, Strauch RJ. The Management of Kienböck Disease: A Survey of the ASSH Membership

Background The purpose of this study was to determine the current trends and common practices for the treatment of Kienböck disease at different stages. Question/Purpose To determine the current trends and common practices by hand surgeons for the treatment of Kienböck disease. Methods A survey with hypothetical Kienböck disease cases stratified by the Lichtman staging system was distributed to the American Society for Surgery of the Hand (ASSH) members. Questions and responses reflected common treatment strategies. Results Of a total of 375 worldwide respondents, preferred treatments of Kienböck disease were as follows: for Stage I disease, an initial trial of splinting was favored (74%), followed by radial shortening osteotomy for continued symptoms. For Stage II disease, 63% of surgeons preferred surgical intervention, particularly radial shortening osteotomy. For Stage IIIa with negative ulnar variance, 69% chose radial shortening osteotomy. Responses were heterogeneous for Stage IIIa Kienböck with positive variance, and capitate shortening osteotomy and vascularized bone grafting were preferred. Salvage procedures predominated for Stage IIIb disease, including proximal row carpectomy (PRC; 42%), intracarpal arthrodesis (21%), and total wrist fusion (10.7%). Similarly, Stage IV disease was treated by 87% of respondents by either PRC or wrist fusion. Without regard to stage of disease, 90% of participants reported using the same Lichtman staging to guide treatment and would also alter treatment strategy based upon ulnar variance. Conclusions Most respondents used Lichtman staging and ulnar variance to guide treatment decisions. Results indicate that the most common surgical treatments were radial shortening osteotomy for early disease and PRC in later stages. Level of Evidence Level IV, Economic/Decision Analysis.

Characteristic features and natural evolution of Kienböck's disease: five years' results of a prospective case series and retrospective case series of 106 patients

OBJECTIVES

Scientific databases index numerous references related to the treatment of Kienböck's disease; yet little is known about the nature of the disease and its pathognomonic features. This study provides a cross-sectional analysis of the pattern and extent of osteonecrosis in a large cohort and a longitudinal analysis to determine the spontaneous disease progression in single patients who have not had surgical management until fragmentation of the lunate.

METHODS

In a prospective case series, the pattern and extent of osteonecrosis were correlated with the duration of symptoms in all patients with Kienböck's disease confirmed using high-resolution 3-T magnetic resonance imaging (MRI) and ultra-thin section computed tomographic (CT) scan since 2009. Furthermore, a retrospective consecutive case series study was conducted to determine the rate of spontaneous evolution in all consecutive patients treated conservatively in our university hospital since 1990.

RESULTS

Among the 35 consecutive patients with Kienböck's disease diagnosed in high-resolution 3-T MRI and ultra-thin section CT, 46% (16/35) presented degeneration of lunate cartilage on CT scan in the first 12 months following the onset of symptoms. Median wrist pain duration of patients presenting a fracture of the lunate was 14 months. Thirty-one percent (11/35) of the patients had arthritis of the lunate, yet no fractures at the time of examination. Of 106 consecutive patients with Kienböck's disease and complete records, who did not have surgical intervention until fragmentation of the lunate, three cases were identified with well-documented spontaneous courses from apparently intact lunate morphology until fragmentation within 6 months.

CONCLUSIONS

Kienböck's disease progresses substantially faster than previously described and, contrary to current classifications, the articular cartilage of the lunate degenerates in early stages.

LEVEL OF EVIDENCE

Diagnostic accuracy, Level IV.

External and internal bone micro-architecture in normal and Kienböck's lunates: a whole-bone micro-computed tomography study

Kienböck's disease is idiopathic osteonecrosis of the lunate, leading to its fracture and collapse. This study compares internal and external bone micro-architecture of normal and fractured lunates (Kienböck's), by using high-resolution three-dimensional (3D) micro-computed tomography (micro-CT) on the whole bone of the two lunate types, and histology. Fractured Kienböck-diseased lunates were obtained from patients undergoing proximal-row-carpectomy, while normal cadaveric lunates served as controls. 3D-micro-CT-imaging of control lunates revealed an encircling cortex surrounding trabecular bone. Trabeculae were arranged in a radial pattern, spanning from the distal to the proximal subchondral plate. Kienböck's lunates exhibited clear fracture lines, with fragmented bone, both proximally and distally, in areas the radially-patterned trabeculae and enveloping cortex were absent, producing height loss. In trabecular bone, Kienböck's lunates revealed increased bone volume fraction, trabecular thickness and number, and decreased trabecular separation and structure model index. Histologically, Kienböck's lunates revealed osteonecrosis, as well as remodeling fronts with osteoblasts and osteoid surrounding bone marrow. Whole-bone high-resolution 3D examination of normal and Kienböck's diseased lunates contributes to a better understanding of micro-architectural changes occurring in the pathology.

A hand therapy protocol for the treatment of lunate overload or early Kienbock's disease

We describe a hand therapy protocol aimed at unloading the wrist and increasing blood supply to the wrist, specifically to the lunate. The protocol was used in a series of patients with clinical radial wrist pain, dysfunction and changes on wrist imaging studies. The patients were not candidates for surgical treatment. Application of the therapy protocol improved objective and subjective parameters such as pain and motion, and may provide a viable treatment option for patients with lunate overload or early Kienbock's disease that are not candidates for surgery.

Morphology and histology of the collapsed lunate in advanced kienböck disease

Morphological and histological changes of 24 collapsed lunates in advanced Kienböck disease were investigated. Articular cartilage of a collapsed lunate were consistently attenuated or disappeared. The proximal articular cartilage facing the radius is generally more affected than the distal articular cartilage facing the capitate. There was one major fracture in addition to multiple minor fractures in the collapsed lunate. Fracture patterns were classified into three types according to the directions of major fracture, namely horizontal type, dual oblique type, and vertical type. There were viable and necrotic areas in the collapsed lunate. Active new bone formation was observed at the junction between the viable and necrotic bone area of the collapsed lunate in advanced Kienböck disease.

A new treatment strategy for Kienböck's disease: combination of bone marrow transfusion, low-intensity pulsed ultrasound therapy, and external fixation

BACKGROUND

The purpose of this study was to investigate the midterm clinical and radiographic outcomes of this new treatment for Kienböck's disease.

METHODS

We applied a new method involving drilling, bone marrow transfusion, external fixation, and low-intensity pulsed ultrasound for patients with Kienböck's disease. Between 2000 and 2006, the treatment was performed in 18 patients (10 men and 8 women; 9 right wrists and 9 left wrists). The preoperative Lichtman stages were stage II in 4 cases, stage IIIa in 11 cases, and stage IIIb in 3 cases. The mean age at surgery was 44.9 years (range 16-68 years), and the mean follow-up period was 63 months (range 28-125 months). The overall results were evaluated using the Mayo wrist score and Nakamura scoring system for Kienböck's disease. Magnetic resonance imaging (MRI) was performed for all patients.

RESULTS

Wrist pain improved to no pain in 13 patients, mild pain in 4 patients, and moderate pain in 1 patient. The average wrist flexion-extension arc was 100° and averaged 120 % of the preoperative value. The average grip strength increased from 50 to 85 % relative to the unaffected side. On roentgenograms, the carpal height ratio (change from 0.53 to 0.51) and the Stahl index (change from 0.38 to 0.32) decreased slightly. On MRI, fatty marrow was recovered in 11 patients (61 %) on proton density-weighted images.

CONCLUSIONS

This method can be used as a less-invasive surgical treatment alternative for Kienböck's disease. At an average follow-up period of 6 years, this new treatment has been shown to be a reliable and durable procedure for patients with Lichtman stage II or stage III Kienböck's disease. Caution should be exercised for patients with a fragmented lunate because of the risk of collapse and nonunion of the lunate.