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

Altered Ulnar Variance With Full-Body Weight-bearing During Handstands With Upper Extremity Weight-bearing CT

PURPOSE

Ulnar variance (UV) is a radiographic measurement relating the articular surface heights of the distal radius and ulna. Abnormal UV increases the risk for wrist pathology; however, it only provides a static measurement of an inherently dynamic bony relationship that changes with wrist position and loading. The purpose of this study was to investigate how full-body weight-bearing affects UV using weight-bearing computed tomography (WBCT).

METHODS

Ten gymnasts completed two 45-second scans inside a WBCT machine while performing a handstand on a flat platform (H) and parallettes (P). A non-weight-bearing CT scan was collected to match clinical practice (N). Differences in UV between weight-bearing conditions were evaluated separately for dominant and nondominant sides, and then, UV was compared between weight-bearing conditions on pooled dominant/nondominant data.

RESULTS

Pooled analyses comparing weight-bearing conditions revealed a significant increase in UV for H versus N (0.58 mm) and P versus N (1.00 mm), but no significant change in UV for H versus P (0.43 mm). Significant differences in UV were detected for H versus N, P versus N, and H versus P for dominant and nondominant extremities. The change from N to H was significantly greater in the dominant versus nondominant side, but greater in the nondominant side from N to P.

CONCLUSIONS

Ulnar variance changed with the application of load and position of the wrist. Differences in UV were found between dominant and nondominant extremities.

CLINICAL RELEVANCE

Upper extremity loading patterns are affected by hand dominance as defined by a cartwheel and suggest skeletal consequences from repetitive load on a dominantly used wrist. Although statistically significant, subtle changes detected in this investigational study do not necessarily bear clinical significance. Future WBCT research can lead to improved diagnostic measures for wrist pathologies affected by active loading and rotational wrist behavior.

An Algorithmic Approach to the Treatment of Kienböck Disease

The algorithm and rationale described is a reflection of our own surgical experience for this challenging disorder and can be compared with other publications. Our algorithm has evolved from treatment of a large volume of patients with Kienböck disease in a referral practice. However, it is limited to the management that we have found logical, effective, and within our scope of experience. The treatment guidelines for our specialty as a whole will evolve as our understanding of the etiology and our ability to quantify efficacy improves.

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.

Volar and Dorsal Blood Supply to the Lunate: A Cadaveric Study

Although various studies have proposed vascular and mechanical factors, the etiology of Kienböck disease is unknown. Kienböck theorized that lunatomalacia resulted from traumatic disruption of blood supply and bony nutrition to the lunate. Extraosseous supply to the lunate, as far as volar or dorsal vessels are concerned, is still controversial. This study evaluated the extraosseous nutrient foramina from the dorsal and volar aspects of lunate specimens. A total of 913 specimens from the Hamann-Todd Osteological Collection in Cleveland, Ohio, were examined. The nutrient artery foramina on left and right lunate specimens were examined from dorsal and volar aspects. The number of nutrient artery foramen was tabulated. Age, sex, and race data were collected. Specimens were divided into groups according to the number of nutrient artery foramina, and the dorsal and volar foramina were compared. The average number of foramina on the dorsal aspect of the lunate (1.71) was greater than the volar aspect (1.64), except in specimens younger than 35 years. A greater number of specimens had 3 or more foramina on the dorsal side compared with the volar aspect. Based on this study, there was significant contribution of dorsal arterial vessels to the blood supply of lunate specimens older than 35 years, which contrasts with findings in earlier studies. The disruption of dorsal intercarpal and radiocarpal ligaments leading to the disruption of the dorsal arterial arches may contribute to vascular insufficiency of the lunate and should be evaluated further in the etiopathogenesis of Kienböck disease. [Orthopedics. 2021;44(2):e243-e247.].

Radial Reference Points for Measuring Palmar Tilt and Ulnar Variance on Lateral Wrist Radiographs

Background: Palmar tilt and ulnar variance are crucial parameters for evaluating the distal radius. Identifying suitable reference points for these parameters on lateral wrist radiographs remains challenging. The purpose of this study was to establish reference points for measuring palmar tilt and ulnar variance on lateral wrist radiographs and to evaluate the reliability of these two parameters using the newly defined reference points. Methods: The distal articular surfaces of 25 cadaver radii were marked at four different locations using thin wires. These bones were radiographed and constant landmarks were recorded. The reliability of the palmar tilt and ulnar variance measurements was assessed using the new reference points and two serial measurements recorded by three observers on 27 standardized lateral wrist radiographs. Results: The reference points for palmar tilt on lateral radiograph were the dorsal and volar end points of the subchondral line. The subchondral line was connected to two of five metaphyseal cortical lines. The reference point for lateral ulnar variance was easily defined on the midpoint of the proximal aspect of the subchondral line. The corresponding posteroanterior central reference point for ulnar variance was at the ulnar corner of the subchondral line. Inter- and intra-observer reliabilities were overall good for the palmar tilt measurements, and excellent for the ulnar variance measurements. Conclusions: Palmar tilt can be determined accurately with a good understanding of the radiographic landmarks on lateral radiographs, and by addressing the problems caused by ulnar inclination of the articular surface of the distal radius. Lateral wrist radiographs can provide a complete picture of the ulnar border of the radius for measuring ulnar variance.

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.

Partial Capitate Shortening Osteotomy and Its Impact on Lunate Revascularization: Mid-Term Results

Background

Treatment of Kienböck disease is still a clinical challenge. The treatment used in each instance is decided according to stage of the disease at presentation. Good clinical and radiological results could be obtained with partial capitate shortening osteotomy. However, mid-term results of this technique and its effect on lunate revascularization are not well known.

Objectives

The aim of this study was to report our results of partial capitate shortening osteotomy in the treatment of stage II and IIIA Kienböck disease.

Methods

Ten patients were enrolled in the study with a mean age of 37.7 years old (standard deviation [SD] = 9.6). Patients were evaluated clinically in terms of range of motion, DASH and VAS scores, satisfaction with the outcome, and grip/tip/palmar/key pinch strength compared to the contralateral side. Radiological evaluation consisted of Lichtman staging on plain radiographs and lunate revascularization on magnetic resonance imaging (MRI) at both preoperative and postoperative evaluations.

Results

The mean duration of follow-up was 55.2 (SD = 24) months. The mean DASH and VAS scores were 14.3 (SD = 6.7) and 1.5 (SD = 1.3), respectively. For patient satisfaction, the mean score was 3.6 (SD = 0.6). The Lichtman stage of 7 patients remained unchanged. Lunate revascularization was detected with MRI in 6 patients.

Conclusions

Although the number of patients in the study prevents more strict conclusions, our results are promising, and the technique presented offers minimally but observable lunate revascularization and high success rates in preventing the progression of the disease.

Risk Factors of Lunate Collapse in Kienböck Disease

PURPOSE

Not all patients with Kienböck disease progress to collapse of the lunate and carpal malalignment, but it is difficult to determine which patients are at risk. We aimed to identify demographic or anatomical factors associated with more advanced stages of Kienböck disease.

METHODS

We included all 195 eligible patients with Kienböck disease and available preoperative posteroanterior and lateral radiographs. We compared the mean age, sex distribution, mean ulnar variance, radial height, radial (ulnarward) inclination, palmar tilt, anteroposterior distance, and lunate type among the different Lichtman stages of Kienböck disease and performed ordinal logistic regression analysis.

RESULTS

We found that patients with more negative ulnar variance had more advanced stages of Kienböck disease (adjusted odds ratio, 1.4). An increase in age was also independently associated with a higher Lichtman stage of Kienböck disease (adjusted odds ratio, 1.02).

CONCLUSIONS

Our findings suggest that more negative ulnar variance may be related to a greater magnitude of lunate collapse in Kienböck disease. Additional long-term study is needed to confirm the longitudinal relationship of negative ulnar variance with progressive Kienböck disease.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

Radiological characteristics of Kienböck's disease in the Korean population

PURPOSE

In Kienböck's disease, the wrist displays certain characteristic radiological parameters, which have been reported to differ among countries. In the present study, we aimed to identify specific radiological parameters of the unaffected wrists in patients with unilateral Kienböck's disease and to determine the extent of the association of each parameter with the disease in Korea.

METHODS

This retrospective case-control study assessed the radiological parameters of patients with Kienböck's disease ( n = 53) and controls ( n = 53), who visited our institution between January 2000 and May 2013. Ulnar variance (UV), radial inclination, lunate fossa inclination, lunate diameter, lunate height, lunate tilting angle (LTA), lunate covering index (LCI), and Ståhl index (SI) were measured and analyzed using a binary logistic regression model.

RESULTS

We observed that wrists with a high LTA and LCI, and low UV and SI had a tendency to develop Kienböck's disease.

CONCLUSION

In the Korean population, a high LTA and LCI, and low UV and SI of the unaffected wrists on plain radiography might be associated with Kienböck's disease. The radiographic characteristics of the unaffected wrists can differ between patients with unilateral Kienböck's disease and normal individuals.

A preliminary exploration of ulnar variance in healthy wrists at a tertiary hospital in Jeddah

Objectives:

To gain preliminary insight by exploring ulnar variance changes in a Saudi-based sample.

Methods:

This 6-month (December 2013 to June 2014) cross-sectional study was conducted on a randomly selected healthy adult volunteers with a sample size of 104, at King Abdulaziz University Hospital, Jeddah, Saudi Arabia. Posteroanterior (PA), anteroposterior (AP), and PA grip views are taken. The variables of interest were the PA, AP, and PA fist measurements of both right and left wrists. An independent t-test was used to compare means between groups.

Results:

A total of 104 volunteers were recruited. Among 17 participants who had a negative ulnar variance on right PA views, a significantly high proportion (n=9; 56.2%) maintained a negative value on fist views; 7 participants (43.8%) had a neutral ulnar variance while none (0%) had a positive value (p<0.001). Similarly, a significant proportion of participants who had neutral, or positive values on right PA views maintained the same values on right fist views (p<0.001). On radiographs of the right wrist, the ulnar variance decreased with a change in wrist position, with an absolute difference in magnitude of 2.13 (p<0.001) between PA and AP views. Similarly, the ulnar variance on the left side decreased significantly between PA and AP views (absolute difference in magnitude, 1.68; p<0.001).

Conclusions:

Ulnar variance changes in our sample are similar to what is reported in the literature.

Radiographic Progression of Kienböck Disease: Radial Shortening Versus No Surgery

PURPOSE

The natural course of the pathophysiology of Kienböck disease is uncertain. Shortening of the radius is believed to modify the pathophysiology by addressing mechanical influences on the lunate. The aim of this study was to compare the radiographic progression of Kienböck disease among patients who had radial shortening osteotomy and patients who had no surgical treatment, with a minimum 1-year interval between radiographs.

METHODS

Among 207 patients with Kienböck disease, we included all 48 eligible patients who had either radial shortening osteotomy or nonsurgical treatment and 2 sets of wrist radiographs available a minimum of 1 year apart. We compared changes in carpal height ratio, Stahl index, and carpal angles between the 2 sets of radiographs and between radial shortening osteotomy and nonsurgical treatment.

RESULTS

We found, on average, a small decrease in the carpal height ratio and the Stahl index in patients who did and did not have surgery, with no differences between the 2 groups. Nearly half of the patients had no decrease in the carpal height ratio and/or the Stahl index.

CONCLUSIONS

Radiographic progression of Kienböck over 1 year or more seems slight on average regardless of treatment. Future research might address the probability of and factors associated with radiographic progression of Kienböck disease.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.

Kienböck Disease: Moving Forward

Over the past decade, a plethora of new information has been reported regarding etiology, natural history, classification, and treatment options for lunate osteonecrosis. New disease classifications have been described based on advanced imaging determination of lunate viability as well as a cartilage-based arthroscopic classification. Here we review the newest literature regarding Kienböck disease and present a new treatment algorithm that incorporates the traditional osseous classification system with a perfusion/viability classification and an articular cartilage-based classification.

Negative Ulnar Variance and Kienböck Disease

PURPOSE

To test the primary null hypothesis that there is no difference in mean ulnar variance (UV) scaled to the length of the capitates between 166 wrists with Kienböck disease and an equal number of matched controls and to test the secondary null hypothesis that mean scaled UV does not vary based on age, sex, or race in both Kienböck and control wrists.

METHODS

Ulnar variance was measured on posteroanterior radiographs of the wrist as the distance between a line through the midpoint between the volar and the dorsal edges of the ulnar margin of the radius and a line tangential to the most distal aspect of the carpal surface of the head of the ulna, both perpendicular to the longitudinal axis of the radius. Measurement of UV was scaled to the length of the capitate, resulting in a UV to capitate height (UV:CH) ratio.

RESULTS

We found a significant difference in mean UV:CH ratio between patients with Kienböck disease and a control group matched by age, sex, race, and limb. The prevalence of negative UV was high in both patients with Kienböck disease and matched controls. There were no differences in mean UV:CH ratio with respect to age, sex, or race among patients with Kienböck disease or matched controls.

CONCLUSIONS

The precise role of ulna minus in the development of Kienböck disease remains uncertain and unanswered, given that many patients with Kienböck disease have neutral or positive UV. In addition, a large proportion of the normal population has negative UV, whereas Kienböck disease is rare.

Long-Term Natural Outcome (7–26 Years) of Lichtman Stage III Kienböck’s Lunatomalacia

Background and Aims:

The natural history of Kienböck’s disease is controversial. Only three papers report a pure natural history without treatment. We hypothesized that the natural course of Kienböck’s disease may be better than reported.

Material and Methods:

We examined eight patients with Lichtman stage III Kienböck’s disease without any treatment, evaluating clinical and radiological results (9 wrists; 7 men, mean age at onset of symptoms 34 years) over a period of 10–38 years (mean, 27.3 years) after symptom onset.

Results:

Lichtman stage remained the same in five of nine wrists. The inner structure of the lunate improved in three, remained the same in three, and deteriorated in three wrists, and its shape improved in two, remained the same in four, and deteriorated in three wrists. Pain averaged visual analog scale 3.1 at rest, 3.4 during motion, 3.6 with slight, and 5.2 with heavy exertion. The range of motion improved at extension 19% and at flexion 14%, reaching 81% and 72% of that of the contralateral wrist, and grip strength reaching 93%. The Disabilities of the Arm, Shoulder, and Hand averaged 11.3, Optional Disabilities of the Arm, Shoulder, and Hand 18.0, and Mayo Clinic score 70.0. The radiographic course did not correlate with clinical course.

Conclusions:

The long-term natural history of Lichtman stage III Kienböck’s disease is insufficiently good to suggest thoughtful observation alone as an option to treat it.

Epidemiology of Kienböck's disease in middle-aged and elderly Japanese women

Little research has been done on the prevalence of Kienböck's disease, and there is no consensus on the relationship between Kienböck's disease and negative ulnar variance. The goal of this cross-sectional study was to determine the prevalence of Kienböck's disease in middle-aged and elderly Japanese women and to clarify the relationship between Kienböck's disease and negative ulnar variance. The authors analyzed plain radiographs of both hands in women 40 years and older residing in the community to investigate the prevalence of Kienböck's disease and the relationship between Kienböck's disease and negative ulnar variance. Kienböck's disease was seen in 7 of the 572 participants. In the group with Kienböck's disease, ulnar variance did not differ significantly between affected (0.3 mm; SD, 1.5) and unaffected (0.3 mm; SD, 1.0; P=.285) sides. No significant difference was seen in ulnar variance values between the affected side in the group with Kienböck's disease and the normal group (P=.118). The number or proportion of participants with negative ulnar variance did not differ significantly between the affected side in the group with Kienböck's disease (3 of 7) and the unaffected side in the group with Kienböck's disease (1 of 7; P=.237) and between the affected side in the group with Kienböck's disease and the normal group (111 of 504; P=.189) by chi-square test. The prevalence of Kienböck's disease was 1.2% in middle-aged and elderly Japanese women. Negative ulnar variance is not a contributing factor to Kienböck's disease.

Proximal Row Carpectomy for Coexisting Kienböck's Disease and Giant Intraosseous Ganglion of the Scaphoid: A Case Report and Review of the Literature

The etiologies of Keinböck's disease and intraosseous ganglion remain unknown. Both entities are rare and the coexistence of these two pathologies in the same patient and hand is even less frequent. We report the case of a 40-year-old man with a longstanding history of martial arts practice (karate) who developed an avascular necrosis of the lunate concomitant with a giant intraosseous ganglion of the scaphoid bone successfully managed by proximal row carpectomy. We review the literature of these two diseases.