Is negative ulnar variance a risk factor for Kienböck's disease? A meta-analysis

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.

Kienböck's disease: preventing disease progression in early-stage disease

Currently Kienböck's disease remains an 'unsolved' problem in hand surgery. Different factors have been associated with the avascular necrosis of the lunate. Mechanical, vascular and biological factors, alone or in combination, may have an influence in the aetiopathogenesis and determine the progress of the disease and even the results of the treatment. This is especially relevant in the early stages, in which conservative or surgical treatment may modify the natural history of the disease, maintaining the lunate structure and thus preserving the joint surfaces. There are multiple surgical treatments for Kienböck's disease in the early stages, before lunate collapse; each one is based on one of the possible factors that can cause avascular necrosis of the lunate. The objective is not only to treat symptoms but to prevent progression. This article is a review of the most frequent treatments used in the early stages and a personal view of the authors.Level of evidence: V.

Association of the Interfacet Angle and the Lunate Facet Inclination Angle With Kienböck Disease

PURPOSE

The etiology of Kienböck disease remains unclear, although mechanical, vascular, and metabolic risk factors have been suggested. We aimed to investigate the association of the angle between the curvatures of the distal radius and the development of Kienböck disease.

METHODS

The lunate facet inclination (LFI), scaphoid facet inclination, and interfacet angle (IFA) values were measured using posteroanterior plain radiographs of 82 patients diagnosed with Kienböck disease. The results were compared with normative angular reference values published based on an analysis of 400 wrists of Caucasian patients aged between 20 and 45 years. The posteroanterior radiographs were divided into 3 categories: negative, neutral, and positive based on ulnar variance, and the relationship between ulnar variance and facet angles was evaluated.

RESULTS

The IFA value was significantly higher than the normative angular reference value in the patients with Kienböck disease. Conversely, the LFI values were significantly lower in the Kienböck patient group. There were no statistically significant differences in the IFA and LFI values among the ulnar variance groups.

CONCLUSIONS

Measuring IFA and LFI allows the evaluation of the bifacet curvature of the distal radius articular surface in the coronal plane. Steep IFA and shallow LFI are associated with Kienböck disease. Increased IFA may lead to abnormal load transmission to the intermediate column, which might eventually lead to increased stress on the lunate.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.

Lunate biomechanics: application to Kienböck's disease and its treatment

Kienböck's disease was initially considered as lunate osteomalacia due to lesions of its nutrient arteries during carpal ligament tears. It has also been suggested following primary fractures, or because of repeated microtrauma. It is only in the past 20 or 30 years that it has appeared as aseptic necrosis. Based on Hultén's hypothesis that a negative radioulnar index was the cause of Kienböck's disease, equalization osteotomies (shortening of the radius or lengthening of the ulna) were developed. The observation of Kienböck's disease in subjects with a positive index and the risk of ulnar abutment after osteotomy led to the introduction of new osteotomies to get around these difficulties, still in the hope of treating the cause of Kienböck's disease. While it has been confirmed that a negative radioulnar index promotes lunate fracture, it clearly does not induce the pathology in the form of necrosis. In this scenario, perilunar osteotomies produce durable decompression, limiting the risk of lunate fracture in case of necrosis by removing the compressive constraints. After comparing the different osteotomies used to treat Kienböck's disease, it seems that the Camembert osteotomy for radius shortening, combined with selective shortening of the ulnar head as described by Sennwald, decompresses the lunate maximally, and protects it long enough for potential natural revascularization to occur.

Kienböck's disease: Where do we stand?

Avascular necrosis of the lunate, commonly known as Kienböck's disease is a disorder that can lead to carpal collapse and the need for surgeries, which can stabilize the wrist. There are different associations with the disease but the exact etiology is unknown. Kienböck's disease is believed to result from mechanical and vascular factors in genetically predisposed individuals. The newer classification based on advanced wrist arthroscopy and MRI help in a better understanding of the disease, early diagnosis, and treatment. A review of recent literature regarding newer treatment options has shown good results in the early stages of osteonecrosis. This article intends to review an update on the etiopathogenesis, classification, and the current advanced treatment options.

Evaluation for Kienböck Disease Familial Clustering: A Population-Based Cohort Study

PURPOSE

Kienböck disease (KD) is rare and its etiology remains unknown. As a result, the ideal treatment is also in question. Our primary purpose was to test the hypothesis that KD would demonstrate familial clustering in a large statewide population with comprehensive genealogical records, possibly suggesting a genetic etiologic contribution. Our secondary purpose was to evaluate for associations between KD and known risk factors for avascular necrosis.

METHODS

Patients diagnosed with KD were identified by searching medical records from a comprehensive statewide database, the Utah Population Database. This database contains pedigrees dating back to the early 1800s, which are linked to 31 million medical records for 11 million patients from 1996 to the present. Affected individuals were then mapped to pedigrees to identify high-risk families with an increased incidence of KD relative to control pedigrees. The magnitude of familial risk of KD in related individuals was calculated using Cox regression models. Association of risk factors related to KD was analyzed using conditional logistic regression.

RESULTS

We identified 394 affected individuals linked to 194 unrelated high-risk pedigrees with increased incidence of KD. The relative risk of developing KD was significantly elevated in first-degree relatives. There was a significant correlation between alcohol, glucocorticoid, and tobacco use and a history of diabetes, and the diagnosis of KD.

CONCLUSIONS

Familial clustering of KD observed in the Utah Population Database cohort indicates a potential genetic contribution to the etiology of the disease. Identification of causal gene variants in these high-risk families may provide insight into the genes and pathways that contribute to the onset and progression of KD.

CLINICAL RELEVANCE

This study suggests that there is a potential genetic contribution to the etiology of KD and that the disease has a significant association with several risk factors.

A Systematic Quality Evaluation of Meta-Analyses Related to Plastic Surgery

INTRODUCTION

Meta-analyses are considered to be an important source of evidence. This review aims to systematically assess the quality of meta-analyses addressing topics in plastic surgery.

METHODS

Electronic databases were selected for systematic review. A search was performed focusing on communication addresses containing terms related to plastic surgery, and detailed inclusion criteria were used. Related data were extracted and recorded according to the items of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. To assess the quality of the meta-analyses over time, studies published before and after PRISMA were evaluated.

RESULTS

A total of 116 meta-analyses were included. There was 1 study that was fully in compliance with the PRISMA items. The main flaws impacting the overall quality of the included studies were in the following areas: structured summary (48%), protocol and registration (2%), full electronic search strategy (35%), risk of bias in individual studies (41%), additional analyses (27%), risk of bias within studies (47%), additional analysis (30%), and funding (47%). Study quality was evaluated using relative risks (RR) with a 95% confidence interval (95% CI); this revealed that there were few significant improvements in adherence to the PRISMA statement after its release, especially in selection (RR, 1.80; 95% CI, 1.08-2.99), results of individual studies (RR, 2.88; 95% CI, 1.41-5.91), synthesis of results (RR, 3.08; 95% CI, 1.32-7.17), and funding (RR, 1.65; 95% CI, 1.21-2.24).

CONCLUSIONS

There have been measurable improvements in the quality of meta-analyses over recent years. However, several serious deficiencies remain according to the PRISMA statement. Future reviewers should pay more attention to not only reporting the main findings but also encouraging compliance with proper standards.

Intracarpal shortening osteotomy for Kienböck's disease: A retrospective study of 28 cases

INTRODUCTION

Kienböck's disease is rare in patients with a neutral or positive ulnar variance. In these situations, treatment is challenging and controversial. Various intracarpal shortening osteotomy (ICSO) procedures have been proposed.

OBJECTIVE

Study the effect of the type of ICSO (isolated capitate osteotomy or combined with hamate osteotomy) on the clinical and radiological outcomes in a retrospective series.

METHODS

Patients with Kienböck's disease were treated with ICSO. A dorsal approach centered over the capitate was used. The transverse osteotomy was located 5mm below the capitate's proximal chondral boundary. The osteotomy cut was 2mm thick. In some patients, a hamate osteotomy was done at the same level as that of the capitate. The osteotomy site was fixed with staples. Cases were classified as with or without a vascularized bone graft was added to the ICSO.

RESULTS

There were 28 cases and the average follow-up was 43 months. Three patients required surgical revision. Pain relief at rest was achieved in all patients. The flexion/extension range of motion was 84°. Strength was 75% of the opposite side. The mean QuickDASH was 32.5 and the PRWE (Patient Related Wrist Evaluation) was 30.2. Isolated capitate osteotomy resulted in better satisfaction and improved ulnar/radial deviation and flexion range of motion. There was no difference in terms of pain, strength and functional scores. However, it triggered a significant increase in the radioscaphoid angle. Adding a vascularized bone graft did not impact the outcomes.

DISCUSSION

Isolated capitate osteotomy provides better outcomes than combined capitate/hamate osteotomy (satisfaction and wrist range of motion) and should be done as the primary procedure. However, since it increases the radioscaphoid angle more than combined capitate/hamate osteotomy, the latter procedure should be used when a large radioscaphoid angle exists preoperatively. We found no benefit of using a vascularized graft.

LEVEL OF EVIDENCE

IV.

The association of Kienbock's disease and ulnar variance in the Iranian population

We retrospectively determined the distribution of ulnar variance in 60 patients with Kienböck's disease. We also measured the ulnar variances in 400 standard wrist radiographs in the normal adult population. The mean ulnar variance of the Kienböck's group was -1.1 mm (SD 1.7) and the mean ulnar variance of the general population was +0.7 (SD 1.5), which was significantly different. In the Kienböck's disease group there were 38 (63%) with ulnar negative, 16 (27%) neutral and six (10%) with ulnar positive variance. The preponderance of ulnar negative variance was statistically significant. There was an association between ulnar negative variance and the development of Kienböck's disease in this study.

Lunate trabecular structure: a radiographic cadaver study of risk factors for Kienböck's disease [corrected]

The aetiology of Kienböck's disease is unknown. Ulnar variance and lunate shape are possible mechanical risk factors. This study assessed the trabecular structure in 29 cadaveric lunates using microCT and correlated this with ulnar variance and lunate shape on plain radiographs and with bone density assessed using conventional CT. The bony trabeculae within the lunate were shown to run almost perpendicular to the proximal and distal joint surfaces in the coronal plane; these trabeculae met the subchondral bone at an angle between 72-102 degrees. In lunates whose proximal and distal articular surfaces are not parallel, the trabecular orientation may be less able to resist compressive forces and more susceptible to fracture.

Clinical research in hand surgery

Clinical research designed to enhance the quality of health care has always received a great deal of national attention. Outcomes studies, clinical trials, and evidence-based research are key components of clinical research that have advanced the field of hand surgery. The purpose of the Weiland Award is to encourage innovations and progress in clinical research in hand surgery for the betterment of patients and to promote hand surgery's visibility in American medicine. This article will highlight my efforts in clinical research through 3 specific research themes: (1) outcomes research, (2) economic analysis, and (3) evidence-based research and quality assessment in health care.

Ageing does not affect ulnar variance: an investigation in Taiwan

This paper presents a longitudinal study of the effect of ageing on ulnar variance. Between 1976 and 1985, ulnar variance in 1000 normal adult subjects was measured using the Palmer method. In 1995 to 2002, 17 to 22 years later, the ulnar variance was measured again in 864 of them. They were stratified into three age groups: Group I consisted of 351 subjects of young age (20-39 year-old), Group II of 318 subjects of middle age (40-59 year-old) and group III of 195 subjects of old age (60 year-old or older). The means of the initial and the final ulnar variance of the whole series and the three groups were compared by the paired Student's t-test. There were no significant differences between the initial and final ulnar variances in all three age groups and in the whole series. In normal subjects without diseases or injuries affecting the wrist, ageing does not affect the ulnar variance.

Is radial shortening useful for Litchman stage 3B Kienbock's disease?

Treatment of Litchman stage 3 Kienböck's disease is still controversial. In this study our aim was to evaluate the effectiveness of radial shortening on stage 3B Kienböck's disease in comparison with stage 3A cases. Radial shortening was performed for 23 patients who had stage 3A (group I, n = 13) and 3B (group II, n = 10) Kienböck's disease between 1994 and 2004. The radial osteotomy was performed 4.5 cm proximal to the distal articular surface. The mean shortening was 2.6 mm (range 2 to 4.5). The average follow-up period was 85 months (range 26-147). Based on the modified Nakamura system, the mean clinical points were 14.3 in group I and 13.3 in group II. There was no statistical difference between both groups with regard to clinical points (P = 0.483). The extension-flexion arc showed significant improvement in both groups. Based on the results of this long-term follow-up study, we concluded that radial shortening osteotomy can be performed in the treatment of type 3B Kienböck's disease as reliably as type 3A, despite the lack of evident radiological improvement.