Well-founded practice or personal preference: a comparison of established techniques for measuring ulnar variance in healthy children and adolescents

Etiology and Diagnostic Challenges of Ulnar Wrist Pain in Pediatric and Adolescent Patients

PURPOSE

Diagnosing the cause of ulnar-sided wrist pain can be difficult in the pediatric and adolescent age group. While frequently used, the diagnostic accuracy of magnetic resonance image (MRI), as compared with intraoperative arthroscopic findings, is not well-described in this population. This study aimed to determine concordance rates between magnetic resonance and arthroscopic findings depending on the specific ulnar wrist pathology.

METHODS

A retrospective review was performed to identify pediatric and adolescent patients who underwent operative treatment of ulnar wrist pain between 2004 and 2021. Patients were included in the analysis if they were <18 years of age, complained of ulnar-sided wrist pain, underwent MRI of the affected wrist with an available report interpreted by a consultant radiologist, and had a diagnostic arthroscopy procedure within one year of imaging. Ulnar pathologies analyzed included triangular fibrocartilage (TFCC) tears, ulnotriquetral (UT) ligament tears, lunotriquetral ligament abnormalities, and ulnocarpal impaction.

RESULTS

A total of 40 patients with a mean age of 15-years-old (range 11 to 17) were included in the analysis. Twenty-four were female, and approximately half had their dominant extremity affected. Most had a history of antecedent trauma (n = 34, 85%), but only 15/40 (38%) had a history of fracture. The mean duration of symptoms prior to presentation was six months (standard deviation, 7). The most common etiologies were Palmer 1B TFCC tears (n = 27, 68%) followed by UT split tears (n = 11, 28%). MRI overall demonstrated high specificity (82% to 94%), but low sensitivity (14% to 71%) for ulnar-sided wrist conditions. Accuracy varied between 70% and 83% depending on the specific injury.

CONCLUSION

While MRI is a useful adjunct for determining the cause of ulnar wrist pathologies, findings are often discordant when compared with diagnostic arthroscopy. Surgeons should have a high degree of suspicion for TFCC-related pathology in the setting of positive provocative clinical examination despite negative MRI findings in young patients.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic IIb.

Pediatric Wrist

Pediatric wrist injuries pose unique diagnostic challenges due to distinct bone characteristics in children and their diverse injury patterns. The dynamic development of the wrist, marked by changes in bone age and emerging ossification centers, is crucial to evaluate growth and identify potential pathologies. The skeletal composition, rich in cartilage, renders bones relatively weaker yet more elastic, impacting their susceptibility to fracture. Forearm fractures display diverse patterns influenced by torsional forces. Scaphoid fractures, less common in children, differ from those in adults. Conditions like Madelung's deformity and ulnar variance are more common wrist disorders in the pediatric population. In addition, the scarcity and nonspecificity of symptoms in those with tendon injuries and triangular fibrocartilage complex lesions can be diagnostically challenging. This article reviews pediatric wrist injuries, emphasizing ossification patterns, common fracture types, and developmental variants. Grasping these complexities in pediatric wrist development and associated pathologies is essential for precise diagnosis and treatment.

Association between carpal height ratio and ulnar variance in normal wrist radiography

INTRODUCTION

The wrist joint is a complex anatomical structure, and various radiographic parameters are utilized to assess its normal alignment and orientation. Among these parameters are carpal height ratio (CHR) and ulnar variance (UV). Previous literature has indicated that factors such as age and gender may influence these parameters; However, there is a lack of studies investigating these differences specifically in the Middle East or Jordan. Additionally, no prior research has explored the relationship between UV and CHR. Therefore, the objective of this study is to investigate these critical radiological parameters and their associations.

METHODOLOGY

A cross-sectional study design was employed, wherein a total of 385 normal wrist X-rays were reviewed, and CHR and UV were measured. Intra-observer and inter-observer reliability assessments were conducted to ensure the consistency and accuracy of measurements. Additionally, the association between UV and CHR was measured and plotted for further analysis.

RESULTS

In our study, the mean CHR was 0.5 (range: 0.4 to 1.5), and the mean UV was - 0.3 mm (range: -5.8 mm to 4.1 mm). We found a significant negative correlation between CHR and age (p < 0.05). No significant gender differences were observed in UV and CHR. Additionally, a weak positive correlation was found between UV and CHR (Pearson correlation coefficient = 0.13, p = 0.01; adjusted R2 = 0.014, p = 0.02).

CONCLUSION

Age correlated significantly with a decline in carpal height ratio. Additionally, ulnar variance had a week positive yet significant correlation with carpal height ratio.

LEVEL OF EVIDENCE

Cross-sectional study, Level III.

Physeal Growth Arrest in Distal Radius Fracture: A Case Report

Introduction

Distal radius fractures account for nearly one-third of all pediatric fractures, making it among the most common of all pediatric fractures. Studies report that distal radius physeal arrest rates following trauma to the distal radius seem to occur in only about 5% of patients. Significant ulnar variance can develop leading to notable pain and limitations in function.

Case Report

We present a case of a 17-year-old right-hand dominant adolescent Caucasian male with persistent ulnar wrist pain. The patient presented to our outpatient clinic for evaluation of his left wrist following 6-8 months of persistent ulnar-sided pain. Ten months prior, the patient had fallen off a shed and was treated in the emergency room and referred to the outpatient clinic for follow-up. The patient initially sustained a Salter-Harris Type 2 distal radius fracture treated with closed reduction and short arm cast application in the emergency room. The short arm cast was removed at 8 weeks, and then, the patient was placed in a brace. The patient was lost to follow-up before returning to the clinic 16 months after the original injury when he noticed worsening pain in the left wrist, localized to the distal radioulnar joint with increased hand usage at a new job. Radiographs at that time showed a worsening positive ulnar variance as well as a partially open distal ulnar physis. After 6 months of occupational therapy and over-the-counter pain management, the ulnar-sided pain had not resolved. The radiograph showed a positive Ulna variance of 2.5 mm, which was corrected with a 5 mm excision osteotomy of the distal ulna. The patient reported significant pain relief and a 42-point improvement in his patient-rated wrist evaluation score.

Conclusion

Distal radius growth arrest, while uncommon, can present with ulnar-sided pain and positive ulnar variance that is safely treatable with ulnar shortening osteotomy.

Ulnar Variance in Athletes: A Scoping Review

CONTEXT

Ulnar variance (UV) is a measurement of the relative locations of the radius and ulna that may become perturbed in athletic populations. Positive UV can be associated with wrist pathologies often treated conservatively or surgically and may result in interruption of sports participation.

OBJECTIVE

This scoping review aims to summarize diagnostic measures of UV in athletes, describe its relation to separate wrist conditions, and present treatment strategies for symptomatic UV.

DATA SOURCES

A systematic search was created and modified for PubMed, CINAHL, Embase, and SPORTDiscus including articles from inception until February 2, 2022.

STUDY SELECTION

Articles including UV characterization, imaging modality style, and an athletic population were searched across multiple databases.

STUDY DESIGN

A scoping review was designed to identify the methods for imaging UV in athletic populations following the PRISMA Extension for Scoping Reviews (PRISMA-ScR).

LEVEL OF EVIDENCE

Level 4.

DATA EXTRACTION

The specific athletic population, imaging modality, measurement style, wrist pathology association, and surgical management of UV were extracted.

RESULTS

A total of 4321 records were screened independently for eligibility: 22 met inclusion criteria. Eight sports comprised the analysis. All studies referenced conventional radiography to diagnose UV; 50% specified the posteroanterior, 18.2% anteroposterior, and 13.6% pronated, gripping radiographs. Hafner's method (7×), Palmer's technique (2×), and the method of perpendiculars (3×) were used to measure UV. Athletes displayed more positive UV than nonathletes and UV became more positive over time in longitudinal studies. Triangular fibrocartilage complex tears, focal lunate necrosis, and ulnar abutment were associated with positive UV. Ulnar shortening osteotomy was the most performed operation for positive UV.

CONCLUSION

Conventional radiography is the gold standard for imaging UV in athletes. Hafner's method is the most commonly used radiograph measurement technique. Wrist pathology in athletic populations may indicate positive UV in need for operative management.

Growth, body composition, and endocrine-metabolic profiles of individuals with Kleefstra syndrome provide directions for clinical management and translational studies

Mendelian neurodevelopmental disorders caused by variants in genes encoding chromatin modification can be categorized as Mendelian disorders of the epigenetic machinery (MDEMs). These disorders have significant overlap in molecular pathways and phenotypes including intellectual disability, short stature, and obesity. Among the MDEMs is Kleefstra syndrome (KLFS), which is caused by haploinsufficiency of EHMT1. Preclinical studies have identified metabolic dysregulation and obesity in KLFS models, but proper clinical translation lacks. In this study, we aim to delineate growth, body composition, and endocrine-metabolic characteristics in a total of 62 individuals with KLFS. Our results revealed a high prevalence of childhood-onset overweight/obesity (60%; 28/47) with disproportionately high body fat percentage, which aligns perfectly with previous preclinical studies. Short stature was common (33%), likely due to advanced skeletal maturation. Endocrine-metabolic investigations showed thyroid dysregulation (22%; 9/41), elevated triglycerides, and decreased blood ammonia levels. Moreover, hand radiographs identified decreased bone mineralization (57%; 8/14) and negative ulnar variance (71%; 10/14). Our findings indicate a high (cardio)metabolic risk in KLFS. Therefore, we recommend monitoring of weight and endocrine-metabolic profile. Supporting a healthy lifestyle and screening of bone mineralization is advised. Our comprehensive results support translational research and contribute to a better understanding of MDEM-associated phenotypes.

Physeal Fractures of the Distal Ulna: Incidence and Risk Factors for Premature Growth Arrest

BACKGROUND

The aim of this study is to assess the rate of distal ulnar growth arrest following physeal fracture and to identify specific risk factors for premature physeal closure.

METHODS

A retrospective review of patients with a distal ulnar physeal fracture was performed at a single United States children's hospital. Patients without 6-month follow-up were excluded. Patient demographics, injury characteristics, treatment, and outcomes were abstracted. Fractures were classified by the Salter-Harris (SH) system. All follow-up radiographs were reviewed for changes in ulnar variance or signs of premature physeal arrest.

RESULTS

Fifty-six children with distal ulnar physeal fracture at a mean age of 10.7±3.3 years were included with a mean follow-up of 1.9 years. The most common fracture pattern was a SH II (52.7%), versus SH I (29.1%), SH III (9.1%), and SH IV (9.1%). Of displaced fractures (41.1%), the mean translation was 40.2±38.3% the and mean angulation was 24.8±20.9 degrees. Eleven fractures (19.6%) demonstrated radiographic signs of growth disturbance, including 3 patients (5.4%) with growth disturbance but continued longitudinal growth and 8 patients (14.3%) with complete growth arrest. The average ulnar variance was -3.4 mm. Three patients underwent subsequent surgical reconstruction including ulnar lengthening with an external fixator, distal ulna completion epiphysiodesis with distal radius epiphysiodesis, and ulnar corrective osteotomy. Patients with displaced fractures and SH III/IV fractures were more likely to develop a growth disturbance (34.8% vs. 3.2%, P =0.003; 50.0% vs. 11.1%, P =0.012, respectively). Children with less than 2 years of skeletal growth remaining at the time of injury had a higher risk of growth disturbance (46.2% vs. 9.5%, P =0.007).

CONCLUSIONS

SH III and IV fractures are more common injury patterns in the distal ulna compared with the distal radius. Growth disturbance or growth arrest occurs in ~20% of distal ulnar physeal fractures. Displaced fractures, intra-articular fractures, fractures requiring open reduction, and older children are at increased risk of distal ulnar growth arrest and should be followed more closely.

LEVEL OF EVIDENCE

Level IV--case series.

The effect of ulnar variance on the pisotriquetral joint

BACKGROUND

Pisotriquetral joint (PTJ) disorders are an important cause of ulnar-sided wrist pain but are often underrecognized. Ulnar variance (UV) has been associated with several wrist pathologies.

PURPOSE

To determine the effect of UV on PTJ in patients with trauma.

MATERIAL AND METHODS

A total of 143 patients (77 men, 66 women; mean age=41.64 ± 18.07 years) were included. Patients with fractures, severe and high-energy trauma, arthritic conditions, avascular necrosis, congenital deformity, bone and soft-tissue tumors, suboptimal image quality, and incorrect joint position were excluded. UV and the amount of PTJ subluxation were evaluated using coronal and sagittal computed tomography images.

RESULTS

PTJ subluxation was divided into five grades. A statistically significant difference was found between the presence of PTJ subluxation and sex (P = 0.045). PTJ subluxation was more common in men (46.8%) than in women (30.3%). There was no significant difference between the presence of PTJ subluxation and age (P = 0.758). The patients were also divided into three groups as positive, neutral, and negative UV. A statistically significant relationship was found between the UV and presence of PTJ subluxation (P = 0.01). PTJ subluxation was significantly less in the neutral (none=51.1%, present=48.9%; P < 0.05) and negative (none=77.8%, present=22.2%; P < 0.05) groups.

CONCLUSION

PTJ subluxation was found to be less among the groups with neutral and negative UV in our study population. PTJ subluxation is more common in men while there is no relationship with age. UV and gender may be risk factors for PTJ subluxation by affecting force dynamics at the wrist joint.

Indications and Timing of Guided Growth Techniques for Pediatric Upper Extremity Deformities: A Literature Review

Osseous deformities in children arise due to progressive angular growth or complete physeal arrest. Clinical and radiological alignment measurements help to provide an impression of the deformity, which can be corrected using guided growth techniques. However, little is known about timing and techniques for the upper extremity. Treatment options for deformity correction include monitoring of the deformity, (hemi-)epiphysiodesis, physeal bar resection, and correction osteotomy. Treatment is dependent on the extent and location of the deformity, physeal involvement, presence of a physeal bar, patient age, and predicted length inequality at skeletal maturity. An accurate estimation of the projected limb or bone length inequality is crucial for optimal timing of the intervention. The Paley multiplier method remains the most accurate and simple method for calculating limb growth. While the multiplier method is accurate for calculating growth prior to the growth spurt, measuring peak height velocity (PHV) is superior to chronological age after the onset of the growth spurt. PHV is closely related to skeletal age in children. The Sauvegrain method of skeletal age assessment using elbow radiographs is possibly a simpler and more reliable method than the method by Greulich and Pyle using hand radiographs. PHV-derived multipliers need to be developed for the Sauvegrain method for a more accurate calculation of limb growth during the growth spurt. This paper provides a review of the current literature on the clinical and radiological evaluation of normal upper extremity alignment and aims to provide state-of-the-art directions on deformity evaluation, treatment options, and optimal timing of these options during growth.

A prediction model for treatment decisions in distal radial physeal injuries: A multicenter retrospective study

BACKGROUND

There are no clearly defined guidelines for the management of distal radial physeal injuries. We aimed to identify the risk factors for patients with distal radial physeal trauma for the risk of deformity, physeal closure, and revision procedure and develop a predictive model.

METHODS

The retrospective study included patients less than 16 years old with displaced distal radial physeal injuries treated between 2011 and 2018 across five centers in the United Kingdom. Deformity was defined as a volar angulation of >11°, dorsal angulation of >15°, a radial inclination of <15° or >23°, or positive ulnar variance. Presence of a bony bar spanning the physis was considered physeal closure.

RESULTS

This study comprised of 479 patients. In that, 32 (6.6%) patients had a second procedure. Also, 49 (10.2%) patients had closure of physis, and 28 (6%) patients had deformity at the end of follow-up. The occurrence of deformity had a strong correlation with age (p = 0.04) and immobilization duration (p = 0.003). Receiver operating characteristic analysis showed that age >12.5 years (p = 0.006) and sagittal angulation of >21.7° (p = 0.002) had a higher odd of deformity. Immobilization for <4.5 weeks (p = 0.01) had a higher revision rate. The nomograms showed good calibration, with a sensitivity of 70% and specificity of 75%.

INTERPRETATION

The nomograms provide accurate, pragmatic multivariate predictive models. Anatomical reduction is recommended in patients >12.5 years of age with >22° of dorsal angulation with cast immobilization for no less than 4.5 weeks. Any revision procedure should be performed within 11 days from the date of injury to reduce the risk of physeal damage.

Ulnar variance and triangular fibrocartilage thickness in adolescents: a cross-sectional MRI study of healthy participants

Skeletally immature wrists are considered at risk of injury due to increased axial loading through a relatively shorter ulna. The aim of this study was to determine whether triangular fibrocartilage thickness relates to ulnar variance and age in adolescents. The radiographs and MRIs of 24 healthy adolescents were retrospectively assessed. Four observers assessed bone age and ulnar variance on radiographs and measured triangular fibrocartilage thickness on MRIs. Median calendar and bone age was 13 years and ulnar variance was -0.7 mm. Median triangular fibrocartilage thickness was 1.4 mm, with excellent inter-observer agreement (r = 0.86). It was moderately correlated with ulnar variance (ρ = -0.46) as well as with bone age (ρ = -0.49). Both variables were statistically significant predictors in a multivariate analysis. This suggests that triangular fibrocartilage thickness changes during skeletal maturation, which might influence axial load distribution in skeletally immature wrists.

Ulnar variance in distal radial fractures: assessment and interpretation

We explored patterns of shortening of the distal radius and investigated the effect of displacement on 'ulnar variance' in 250 patients with distal radial fractures. A small number of patients (5%) had a fracture that resulted in true shortening. Thirty-two per cent had fractures that appeared short, but lateral radiographs revealed that the articular surface was tilted, with either the anterior or dorsal rim of the articular surface being proximal to the distal ulna but the other rim was distal to it. We recommend initial assessment of variance on lateral radiographs. If the anterior and dorsal rims of the distal radial articular surface are proximal to the distal ulna, then true shortening is present and lengthening and stabilization, to hold the radius distracted, should be considered. If only one rim is proximal to the distal ulna, then correction of the tilt will lessen the apparent positive variance.Level of evidence: IV.

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.

Acute Bony Injuries of Hand and Wrist

Acute bony injuries to the hand and wrist are very common after a fall on an outstretched hand. In the wrist, distal radius fractures are the most common; isolated distal ulna fractures are uncommon. More serious injuries to the wrist include complicated fracture-dislocation injuries such as perilunate dislocations. At the carpal level, scaphoid fractures are the most common followed by fractures of the dorsal side of the triquetrum. The metacarpals often fracture, most commonly the base of the thumb and the subcapital region of the fifth metacarpal. In the fingers, we encounter many different types of fractures, often avulsions reflecting underlying soft tissue pathology (e.g., mallet finger). Dislocations are common in the fingers, predominantly in the distal interphalangeal joints. From an imaging standpoint, conventional radiography is always the initial examination. Complex (intra-articular) fractures, fracture-dislocation injuries, and a strong clinical suspicion of radiographically occult fractures need to be further evaluated for decision making regarding treatment. Computed tomography is the primary imaging modality of choice for the first two. In the latter, magnetic resonance imaging can be preferable, depending on clinical suspicion and the local situation in the associated hospital.

Casting in finger trap traction without reduction versus closed reduction and percutaneous pin fixation of dorsally displaced, over-riding distal metaphyseal radius fractures in children under 11 years old: a study protocol of a randomised controlled trial

INTRODUCTION

Distal radius is the most common site of fracture in children, comprising 23%-31% of all paediatric fractures. Approximately one-fifth of these fractures are displaced. Completely displaced distal metaphyseal radius fractures in children have traditionally been treated with closed reduction. Recent evidence suggests that correcting the shortening in over-riding distal metaphyseal radius fractures is not necessary in prepubertal children. To date, no published randomised controlled trial (RCT) has compared treatment of these fractures in children by casting the fracture in bayonet position to reduction and pin fixation.

METHODS AND ANALYSIS

We will conduct an RCT to compare the outcomes of casting the fracture in bayonet position in children under 11 years of age to reduction and percutaneous pin fixation. 60 patients will be randomly assigned to casting or surgery groups. We have two primary outcomes. The first is ratio (injured side/non-injured side) in the total active forearm rotation and the second is ratio (injured side/non-injured side) in total active range of motion of the wrist in the flexion-extension plane at 6 months. The secondary outcomes will include axial radiographic alignment, passive extension of the wrists, grip strength and length of forearms and hands, patient-reported outcome QuickDASH and pain questionnaire PedsQL. Patients not willing to participate in the RCT will be asked to participate in a prospective cohort. Patients not eligible for randomisation will be asked to participate in a non-eligible cohort. These cohorts are included to enhance the external validity of the results of the RCT. Our null hypothesis is that the results of the primary outcome measures in the casting group are non-inferior to surgery group.

ETHICS AND DISSEMINATION

The institutional review board of the Helsinki and Uusimaa Hospital District has approved the protocol. We will disseminate the findings through peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT04323410.

PROTOCOL

V.1.1, 29 September 2020.

Cast immobilization in bayonet position versus reduction and pin fixation of overriding distal metaphyseal radius fractures in children under ten years of age: a case control study

PURPOSE

Completely displaced distal radius fractures in children have been traditionally reduced and immobilized with a cast or pin fixed. Cast immobilization leaving the fracture displaced in the bayonet position has been recently suggested as a non-invasive and effective treatment alternative. This is a pilot comparative study between reduction and no reduction.

METHODS

We assessed subjective, functional and radiographic outcome after a minimum 2.5-year follow-up in 12 children under ten years of age who had sustained a completely displaced metaphyseal radius fracture, which had been immobilized leaving the fracture in an overriding position (shortening 3 mm to 9 mm). A total of 12 age-matched patients, whose similar fractures were reduced and pin fixed, were chosen for controls.

RESULTS

At follow-up none of the 24 patients had visible forearm deformity and the maximal angulation in radiographs was 5° Forearm and wrist movement was restored (< 10° of discrepancy) in all 24 patients. Grip strength ratio was normal in all but three surgically treated patients. All patients had returned to their previous activities. One operatively treated boy who was re-operated on reported of pain (visual analogue scale 2).

CONCLUSION

The results of this study do not demonstrate the superiority of reduction and pin fixation over cast immobilization in the bayonet position of closed overriding distal metaphyseal radius fractures in children under ten years with normal neurovascular findings.

LEVEL OF EVIDENCE

III.

The triangular fibrocartilage complex on high-resolution 3 T MRI in healthy adolescents: the thin line between asymptomatic findings and pathology

OBJECTIVE

The objective of the study is to provide a reference for morphology, homogeneity, and signal intensity of triangular fibrocartilage complex (TFCC) and TFCC-related MRI features in adolescents.

MATERIALS AND METHODS

Prospectively collected data on asymptomatic participants aged 12-18 years, between June 2015 and November 2017, were retrospectively analyzed. A radiograph was performed in all participants to determine skeletal age and ulnar variance. A 3-T MRI followed to assess TFCC components and TFCC-related features. A standardized scoring form, based on MRI definitions used in literature on adults, was used for individual assessment of all participants by four observers. Results per item were expressed as frequencies (percentages) of observations by all observers for all participants combined (n = 92). Inter-observer agreement was determined by the unweighted Fleiss' kappa with 95% confidence intervals (95% CI).

RESULTS

The cohort consisted of 23 asymptomatic adolescents (12 girls and 11 boys). Median age was 13.5 years (range 12.0-17.0). Median ulnar variance was -0.7 mm (range - 2.7-1.4). Median triangular fibrocartilage (TFC) thickness was 1.4 mm (range 0.1-2.9). Diffuse increased TFC signal intensity not reaching the articular surface was observed in 30 (33%) observations and a vertical linear increased signal intensity with TFC discontinuation in 19 (20%) observations. Discontinuation between the volar radioulnar ligament and the TFC in the sagittal plane was seen in 23 (25%) observations. The extensor carpi ulnaris was completely dislocated in 10 (11%) observations, more frequent in supinated wrists (p = 0.031). Inter-observer agreement ranged from poor to fair for scoring items on the individual TFCC components.

CONCLUSION

MRI findings, whether normal variation or asymptomatic abnormality, can be observed in TFCC and TFCC-related features of asymptomatic adolescents. The rather low inter-observer agreement underscores the challenges in interpreting these small structures on MRI. This should be taken into consideration when interpreting clinical MRIs and deciding upon arthroscopy.