Negative Ulnar Variance and Kienböck Disease

Kienböck Disease: Recent Advances in Understanding and Management

➢ An at-risk lunate (due to anatomic factors) subjected to a trigger event (axial load, embolism, hypercoagulability) leads to the development of lunate osteonecrosis.➢ Children, adolescents, and elderly patients with Kienböck disease respond well to nonoperative treatments, and this should be considered before any surgical intervention.➢ For disease limited to the lunate, treatment decisions should be driven by the condition of the cartilage; intact lunate cartilage can be treated with joint leveling or core decompression, whereas disrupted cartilage surfaces should be bypassed with scaphocapitate or scaphotrapeziotrapezoid arthrodesis. Newer surgical procedures such as wrist arthroscopy and the introduction of contrast-enhanced magnetic resonance imaging have expanded the treatment options for these patients.➢ Once disease extends outside of the lunate, reconstruction with proximal row carpectomy or partial or total wrist arthrodesis should be considered on the basis of which articular surfaces are affected.➢ The new unified classification system and treatment are applicable to almost all patients with Kienböck disease.

Comparison of Clinical Outcomes in Open and Arthroscopically-Assisted Mini Open Proximal Row Carpectomy for Lichtman Stage IIIB and IIIC Kienböck Disease

PURPOSE

Proximal row carpectomy (PRC) can be performed in the late stages of Kienböck disease using the traditional open technique or arthroscopically. In this study, we describe the arthroscopically-assisted mini-open PRC technique. The aim of the study was to compare the functional results with the open PRC technique in advanced-stage Kienböck disease.

METHODS

The medical records of patients with Kienböck disease who underwent open PRC between 2006-2010 (Cohort A) and arthroscopically-assisted PRC (AAPRC) between 2010-2018 (Cohort B) were analyzed. The Quick Disabilities of the Arm, Shoulder, and Hand scores, visual analog scale, and Modified Mayo Wrist Scores were compared, which were obtained at the early postoperative (third month) and final follow-up.

RESULTS

Cohort A had 14 and Cohort B 21 patients. The preoperative, early, and final mean visual analog scale scores were 7, 3, and 0.3, respectively, for Cohort A, and 7, 0.3, and 0.1, respectively, for Cohort B. The preoperative mean Quick Disabilities of the Arm, Shoulder, and Hand scores decreased from 69 to 34 at the third-month and 6.1 on the final follow-up visit for Cohort A and from 77 to 18, and 5 for Cohort B. The final Mayo wrist scores were excellent in 4, good in 4, and moderate in 6 of the Cohort A patients, and excellent in 11, good in 8, and moderate in 2 of the Cohort B patients. Mean flexion increased to 52° from 43° for Cohort A and to 62° from 41° for Cohort B.

CONCLUSIONS

AAPRC, compared to the open PRC, resulted in increased wrist motion and increased Mayo wrist scores in the long-term. Also, the third-month patient-related outcomes revealed favorable results in the AAPRC group. We attribute these findings to the earlier initiation of postoperative wrist motion and the less invasive character of the AAPRC procedure.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Imaging of Anatomical Variants Around the Wrist and Hand

Wrist and hand anatomy may present several clinically relevant variants that involve bones, muscles, tendons, and nerves. Thorough knowledge of these abnormalities and their appearance in imaging studies is useful for proper management. In particular, it is necessary to differentiate the incidental findings that do not represent a trigger for a specific syndrome from those anomalies causing symptoms and functional impairment. This review reports the most common anatomical variants encountered in clinical practice and briefly discusses their embryogenesis, related clinical syndrome if present, and their appearance using different imaging techniques. The information each diagnostic study (ultrasonography, radiographs, computed tomography, and magnetic resonance imaging) may provide is described for each condition.

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.

Morphometric Analysis of Ulnar Variance and Its Demographic Dynamics Using High Resolution MRI: A Retrospective Study in Indian Population and Review of Literature

Background

Ulnar variance (UV) is the variation of the level of the distal articulating surface of the radius with respect to the distal articulating surface of the ulna. These variations either positive or negative can predispose to pathologies involving the wrist joint. The aim of this study was to measure the ulnar variance in a subset of Indian population using high-resolution MRI and compare our results with the existing literature.

Materials and Methods

Retrospective analysis of 100 normal wrist MRIs were done performed during November 2020 to November 2021 and the ulnar variance was calculated using the Method of Perpendiculars. All the MRI sequences were performed by an experienced radiologist with prior fixed protocol for the study. The measurements were done on the mid-coronal section based on the Method of Perpendiculars using Meddiff Rispacs software.

Results

The average age of the participants was 42 years, with Male to female ratio of 0.9:1. 47 MRIs were of the left wrist, while 53 MRIs were of the right wrist. The mean UV was - 0.7 mm (SD-0.175), ranging from - 4.5 mm to 3.5 mm. There was a significant relationship between ulnar-variance and age, as ulnar-variance increases with the age (p value = 0.039). There was no statistically significant correlation of ulnar-variance with gender distribution and handedness.

Conclusions

This study utilized high-resolution MRI for measuring ulnar-variance in a subset of Indian population and disclosed that the ulnar-variance affirms a positive correlation with age, while no specific pattern between the ulnar-variance and gender or handedness could be established.

Graphical abstract

The association of three anatomical factors with ulnar-sided wrist pain: a radiological study

BACKGROUND

Ulnar-sided wrist pain is associated with the development of multiple wrist pathologies. But the anatomical etiologies have not been fully understood.

PURPOSE

To determine the association of three anatomical factors with ulnar-sided wrist pain, including ulnar variance (UV), distal ulnar volar angle (DUVA), and pisiform-ulnar distance (PUD).

MATERIAL AND METHODS

A total of 64 patients who had ulnar-sided wrist pain associated with training injuries were retrospectively studied. A control group included 64 healthy athletes from the same unit. The UV, DUVA, and PUD of each individual was measured on radiographs.

RESULTS

The average UV and DUVA of those in the ulnar-sided pain group were 0.84 mm and 174.65°, respectively; the control group values were 0.39 mm and 175.11°. The differences between the two groups had no statistical significance (P > 0.05). The average PUD of the ulnar-sided wrist pain group was shorter than that of the control group (2.37 cm vs. 2.65 cm); the difference had statistical significance (P < 0.05). PUD had a negative correlation with ulnar-sided pain; it was an anatomical protective factor (odds ratio = 0.01; P < 0.00; 95% confidence interval=0.00-0.05). Both UV and DUVA had no significant correlations with ulnar-sided wrist pain (P > 0.05).

CONCLUSION

PUD has a significant correlation with ulnar-sided wrist pain. It is the anatomical protective factor. Both the UV and DUVA have no statistical association with ulnar-sided wrist pain, but we cannot ignore their potential pathogenic effects on wrists, and further studies are needed to confirm the results.

Medium-term clinical and radiological results of surgically treated stage 3A Kienböck's disease

The purpose of this study was to compare the methods of distal radial shortening osteotomy (RSO), lateral closing distal radial wedge osteotomy (RWO), and scaphotrapeziotrapezoid (STT) fusion in the treatment of stage 3A Kienböck's disease (KD). The research was planned as a single-center and retrospective study for the period 2008-2018. Patients were allocated to three groups according to surgical method: group 1, patients with negative ulnar variance, undergoing RSO; group 2, patients with non-negative (neutral or positive) ulnar variance, undergoing RWO; and group 3, patients with non-negative ulnar variance, undergoing STT fusion. Radiological measurements were compared: pre- and postoperative Stahl index, radioscaphoid angle, and carpal height ratio. Clinical comparison used QuickDASH and modified Mayo wrist scores. Fifty-one patients, with a mean age of 34 ± 12 years (range; 16-69 years), were included. Mean follow-up was 4.47 ± 1.8 (range 2-9) years. No statistically significant difference was observed between the groups in terms of change in carpal height ratio or Stahl index (respectively; P = 0.08, P = 0.065). A significant difference was observed in change in radioscaphoid angle between patients undergoing STT fusion versus RWO (P < 0.05). There was no statistically significant difference in postoperative functional scores between groups, and similar postoperative functional scores were achieved with STT fusion and with RWO in the surgical treatment of stage 3A KD with positive or neutral ulnar variance. Good medium-term radiological and clinical results were obtained with RSO in patients with stage 3A KD with negative ulnar variance.

Effect of gadolinium perfusion magnetic resonance imaging on surgeons' management preferences in kienböck's disease. A survey study

In literature, the use of gadolinium perfusion magnetic resonance imaging (GP-MRI) is recommended in Kienböck's disease to evaluate the lunate bone's perfusion. This survey study sought to assess how GP-MRI findings affect the management preferences of hand surgeons. A questionnaire consisting of 11 scenarios differing in ulnar variance, GP-MRI findings and management preferences was developed. The scenarios were designed based on the last published clinical guidelines. The questionnaire was sent to the members of a national hand surgery society consisting of 160 hand surgeons. Sixty-six surgeons completed the questionnaire. The surgeons' preferences changed significantly by ulnar variance in stages II and IIIA, and by GP-MRI in stages I and II. No need for other diagnostic tools was found in any of the scenarios. Management preferences of the study participants related to alterations in ulnar variance and treatment choices in all stages were in accordance with previously published clinical and survey studies. This study showed that GP-MRI findings significantly changed the management preferences of hand surgeons in early stages of Kienböck's disease. There was no significant tendency among the participants to use further assessment tools beyond direct radiography, MRI, and GP-MRI. Given the study results and the literature, we emphasize the limited and well-defined indications of GP-MRI in Kienböck's disease.

Morphology at the Distal Radioulnar Joint: Identifying the Prevalence of Reverse Obliquity

Background  Recent advances in the understanding of ulnar-sided wrist pathologies such as ulnar abutment syndrome (UAS) have brought increased attention to the anatomy of the distal radioulnar joint (DRUJ). Previous work established three anatomical variants of the sigmoid notch (parallel, oblique, and reverse oblique). The reverse oblique DRUJ poses theoretical risk of increased contact forces following ulnar shortening osteotomy, a common method of treating UAS. Purpose  As prevalence of reverse oblique morphology has been under-reported, this study aims to better define the prevalence of reverse oblique morphology in the adult population. Methods  Institutional Review Board-approved review of 1,000 radiographs over a 2-year period was performed. Demographic data and radiographic measurements were recorded (ulnar variance, notch inclination, and presence of arthritis). Correlation tests, a test of proportions, a t -test, and linear and logic regression tests were used to examine associations between ulnar variance, sigmoid inclination, sex, age, and presence of arthritis. Results  One thousand radiographs were analyzed revealing prevalence rates of: parallel-68%, oblique-26%, and reverse oblique-6%. Females were significantly more likely to have reverse inclination. No significant correlation was noted for morphology by age. Ulna positive variance was negatively correlated with reverse inclination. DRUJ arthritis was noted in 14% of patients. Higher sigmoid inclination was associated with higher odds of presence of arthritis, adjusting for sex and age. Higher incidence of arthritis was noted among patients with the oblique (20.8%) or reverse oblique (24.6%) compared with parallel (10.5%) morphology. Conclusion  This series of 1,000 radiographs demonstrates a 6% overall prevalence of reverse obliquity. This large dataset allows for better quantification of the prevalence of DRUJ morphologies and determination of correlations that have clinical implications for patients with ulnar-sided wrist pathology. Level of Evidence  This is a Level IV study.

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.

Treatment of Advanced Kienbock's Disease (Lichtman Stage IIIB with Carpal Collapse) by a Shortening Osteotomy of the Radius: 21 Cases

Purpose  To review the results of shortening osteotomies of the radius in our stage IIIB Kienbock's disease patients. Materials and Methods  In the past 30 years, we treated 52 cases of Kienbock's disease by a shortening osteotomy of the radius, of which 21 already had carpal collapse. All patient charts and X-rays were reviewed, but only the cases already with carpal collapse (stage IIIB) are presented here. Results  All patients improved after surgery. Pain, on a scale of 0 to 3, generally 2 or 3 before surgery (median: 2.3), was normally 1 or 0 afterward (median: 0.9); median flexion-extension of the wrist improved from 77 to 99 degrees; and grip strength of the other hand improved from 26 to 76%. The last clinical and radiological review was performed 1 to 23 years after surgery (median: 8 years). Conclusion  Advanced Kienbock's disease with carpal collapse is not a contraindication for carpal-sparing surgery radial shortening osteotomy.

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.

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.

Diagnostic modalities for distal radioulnar joint

The first imaging modality in patients suspected of distal radioulnar joint pathology should be conventional radiography to exclude or diagnose wrist pathology including osteoarthritis, rheumatoid arthritis, calcium pyrophosphate deposition disease, (healed) fractures, or impaction syndromes. When conventional radiography is inconclusive, high resolution 3 Tesla magnetic resonance imaging is advised. We provide a broad overview of the literature regarding the use of intra-articular contrast both with computed tomography (CTA) or magnetic resonance imaging (MRA). Conventional arthrography and unenhanced computed tomography are not indicated. This article discusses the most useful imaging techniques in terms of clinical indications, patient positioning, technical imaging requirements, and diagnostic performance in patients with suspected distal radioulnar joint pathology. Furthermore, the most prevalent pathologies are discussed, with the focus on imaging characteristics in both stable and unstable distal radioulnar joints.

Treatment of Advanced Kienböck Disease With a Vascularized Radial Bone Flap Wrapped in the Pronator Quadratus

PURPOSE

In the present study, we aimed to assess the radiologic and clinical outcomes after excision of the lunate, insertion of a vascularized radial bone flap wrapped in the pronator quadratus, and distraction with an external fixator of the joint, for the treatment of avascular necrosis of the lunate with carpal height collapse, fragmentation, and perilunar osteoarthritic changes.

MATERIALS AND METHODS

From May 2006 to July 2014, a total of 25 patients (13 men and 12 women; mean age, 38.7 years; age range, 28-52 years) with advanced Kienböck disease were treated with excision of the lunate and insertion of a vascularized radial bone flap wrapped in the pronator quadratus, followed by distraction with an external fixator of the joint; all these patients met our inclusion criteria, including symptomatic avascular necrosis of the lunate with carpal collapse and osteoarthritis of the wrist. We evaluated the scaphocapitate angle for radiologic assessment. Moreover, the overall clinical results were graded by using the wrist range of motion, modified Mayo wrist score, and disabilities of the arm, shoulder, and hand score.

RESULTS

All the patients exhibited improved symptoms, and subsequently returned to their work and recreational activities. The mean scaphocapitate angles and carpal height ratio improved from 33.7 degrees (range, 32.1-35.7 degrees) and 0.46 degrees (range, 0.42-0.51 degrees) preoperatively to 56.3 degrees (range, 54.7-59.8 degrees) and 0.50 degrees (range, 0.46-0.56 degrees) at the follow-up, respectively. The final average range of motion was as follows: wrist flexion, 73 degrees (range, 62-81 degrees); and extension, 76 degrees (range, 69-88 degrees). The average postoperative modified Mayo wrist score and disabilities of the arm, shoulder, and hand score were 91 points (range, 80-100 points) and 11 points (range, 2-24 points), respectively.

CONCLUSION

We suggest that the excision of the lunate and insertion of a vascularized radial bone flap wrapped in the pronator quadratus, followed by distraction with an external fixator of the joint, is a reliable method for the treatment of Kienböck disease with collapse or fragmentation of the lunate, and achieves high functional scores, increased range of movement, and relief of pain, without any complications.

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.