Ulnar-sided wrist pain. Part I: anatomy and physical examination

Treatment of Hand and Wrist Cartilage Defects in Athletes

Cartilage injuries of the hand and wrist can be debilitating in the athlete. Diagnosis is difficult given the broad spectrum of presenting symptomatology. History and physical examination is crucial to achieve the correct diagnosis, and advanced imaging can offer helpful assistance to the clinician as well. TFCC injuries and ulnar impaction syndrome are among the most common conditions in athletes with hand and wrist pain. Treatment of these injuries is initially nonoperative, but elite athletes may elect to bypass nonoperative treatment in favor of earlier return to sport. Surgical treatment varies but can include open and arthroscopic methods. The clinician should tailor treatment plans to each athlete based on level of competition, type of sport, and individual preferences and goals.

Ulnar-Sided Wrist Pain: A Diagnostic Evaluation Guide From 30-Plus Years of Experience

INTRODUCTION

While multiple ulnar-sided wrist pain (USWP) diagnostic evaluation guides have been presented, none have included original clinical data or statistical analysis. The purpose of this study is to provide a diagnostic evaluation guide derived from original clinical data and analysis to help clinicians arrive at a differential diagnosis for USWP.

METHODS

Using a computer search of patients presenting with sprains, instability, and laxity of the wrist, 385 patient charts were identified. Patient demographics, mechanism of injury, subjective complaints, physical findings, and diagnostic test findings were reviewed. Statistical analysis was performed to determine sensitivity and specificity of diagnostic methods on their ability to identify lunotriquetral ligament tears, triangular fibrocartilage complex (TFCC) tears, and ulnar impaction syndrome. Diagnostic arthroscopy was used as the reference standard.

RESULTS

Ninety-three patients, comprising 101 cases of USWP, were included in the study. The onset of injury was traumatic in 83 out of 101 cases with motor vehicle accidents (N=46) being the most common, followed by overuse (N=18), and a fall onto an outstretched hand (N=16). The ulnocarpal tenderness test exhibited sensitivity/specificity of 72%/33%; lunotriquetral ligament laxity test of 42%/62%; bone scan of 80%/33%; radiocarpal arthrogram of 90%/98% for TFCC tears and 50%/91% for lunotriquetral ligament tears; midcarpal arthrogram of 82%/86% for lunotriquetral ligament tears. The mean ulnar variance on standard posteroanterior view radiograph was 0.95 mm, increasing to 2.67 mm on gripping posteroanterior view.

CONCLUSION

Physicians should suspect a lunotriquetral ligament and/or TFCC tear with the acute onset of USWP following a loaded dorsiflexed mechanism of injury. Ulnocarpal tenderness tests and pre-operative ulnar variance measures are effective for increasing suspicion of USW pathology. Bone scans are helpful in diagnosing ulnar impaction syndrome in conjunction with radiographic findings. A combination of midcarpal arthrogram for lunotriquetral ligament tears and radiocarpal arthrogram for TFCC tears should be employed.

Comparative Analysis of Treatment Outcomes: Modified Ulnar Gutter Slab vs. Sugar Tong Slab for Distal Radioulnar Joint Instability Following Triangular Fibrocartilage Complex Repair

The standard treatment for distal radioulnar joint (DRUJ) instability involves repairing the triangular fibrocartilage complex (TFCC) and immobilizing the joint with a sugar tong slab, but this can cause elbow stiffness. To address this, a modified ulnar gutter slab was designed to enhance elbow mobility during immobilization. A prospective randomized controlled trial was conducted on 23 DRUJ instability patients who underwent arthroscopic TFCC repair. Two post-operative splinting techniques were compared: the modified ulnar gutter slab and the sugar tong slab. The assessment included the Disabilities of Arm, Shoulder, and Hand (DASH) score; elbow, forearm, and wrist range of motion (ROM); post-operative DRUJ stability; and complications. DASH scores at 4 and 6 weeks were not significantly different. However, the modified ulnar gutter slab improved elbow extension range of motion at 4 weeks (extension lag: 20.0 vs. 6.5 in the sugar tong group) (p = 0.011). Post-operative DRUJ stability was comparable between the two groups. Notably, one patient in the sugar tong slab group experienced complex regional pain syndrome (CRPS). The modified ulnar gutter slab offers a post-operative alternative after TFCC repair. It effectively immobilizes forearm and wrist motion while enhancing elbow mobility, potentially reducing post-operative elbow stiffness.

Wrist motion is distinct between touch screen and manual or digital devices

BACKGROUND

Restricted motion during touch screen device use may contribute to wrist overuse injuries. Wrist radioulnar deviation and extension while using touch screen devices and digital or manual counterparts in male and female medical professional dominant and non-dominant hands were quantified to test the hypothesis that mobile touch screen device use reduces wrist motion.

METHODS

An active motion detection system was used to record wrist motion of 12 participants while: tablet swiping and turning book pages; raising a cell and traditional phone to the ear; texting and typing; and entering numbers on a cell phone and manual calculator. Medial and lateral wrist surface range of motion (ROM) and minimum and maximum wrist radial-ulnar deviation and flexion-extension were quantified.

RESULTS

Device, sex and handedness effects were determined (P<0.05). Maximum medial radial deviation and ROM were greater using a cell versus traditional phone. Maximum medial radial deviation was higher in the nondominant wrist during backward tablet swiping and while backward page turning versus tablet swiping. Maximum and minimum medial extension angles and ROM were greater while typing versus texting. Female nondominant hand maximum lateral extension and ROM were greater for typing versus texting and maximum medial extension and lateral extension ROM greater during manual versus cell phone calculator use with handedness combined. Maximum lateral extension and ROM were greater in females versus males using manual calculators.

CONCLUSIONS

Sex and handedness should instruct touch screen, digital and manual device design and use for optimal performance and injury prevention.

It Is Not Only the Meniscus That Flips-A Case of TFCC Tear with a Flipped Fragment in the Distal Radioulnar Joint

Acute wrist injuries with ongoing ulnar-sided wrist pain warrant a magnetic resonance imaging (MRI) to diagnose ligamentous injuries. Triangular fibrocartilage complex (TFCC) tears have been classified and described in the literature but complex tear patterns have limited representation. Bucket-handle tears of the TFCC represent only 0.5% of TFCC tears and have recently been identified, posing a diagnostic and management challenge. Preoperative diagnosis is possible with MRI and necessary for optimal and early surgical management. The authors describe a unique case of a flipped tear of the central disc of the TFCC, where the fragment was flipped into the distal radioulnar joint, a site hidden during routine arthroscopy.

Clinical and Radiographic Evaluation of Ulnar-Sided Wrist Pain

PURPOSE OF REVIEW

Ulnar-sided wrist pain is a challenging diagnostic workup. A thorough and complete physical examination followed by appropriate radiographic studies can help the clinician diagnose and treat these conditions.

RECENT FINDINGS

Recent research has been focused on diagnostic modalities such as arthroscopy and high-resolution MRI. Ulnar-sided wrist pain is a challenging clinical workup that must be approached systematically with the aid of adjunctive diagnostic modalities.

Calcific tendinopathy of the pronator quadratus muscle: A rare site and cause of ulnar sided wrist pain

Ulnar -sided wrist pain is a common complaint and can present a diagnostic challenge for a musculoskeletal clinician. Calcific tendinopathy is a well-recognised disorder related to the deposition of calcium hydroxyapatite crystals within tendons. Classically, tendons around the shoulder and the hip joints are the most commonly affected sites. We report a rare site of calcific tendinopathy of the Pronator Quadratus muscle presenting with ulnar-sided wrist pain in a 36-year-old male posing a diagnostic dilemma. This case-report highlights the importance of a thorough clinical evaluation and crucial role of cross-sectional imaging in reaching a diagnosis of calcific tendinopathy of the Pronator Quadratus muscle as unusual cause of ulnar-sided wrist pain. This is the first reported case of calcific tendinopathy in pronator quadratus in the literature we could review.

Wrist weight-bearing tolerance in healthy adults

STUDY DESIGN

Cross-sectional.

INTRODUCTION

No information is available in the literature regarding the amount of weight-bearing tolerance in a normal human wrist.

PURPOSE OF THE STUDY

To establish the normal limits of human wrist weight-bearing tolerance and to determine if gender, age and height are predictors of this weight-bearing tolerance.

METHODS

A sample (N = 465) of healthy adults ages 18-64 completed a questionnaire indicating their gender, age range and height. Subjects were instructed in performing a wrist weight-bearing tolerance test using a calibrated analog scale. The amount of pressure that the subject was able to apply to the scale in 3 independent trials was recorded and analyzed.

RESULTS

A strong positive correlation was found between average weight- bearing values achieved through the right and left hands for the subjects of this study, r(463)= .97, P < .001. A 2-way analysis of covariance revealed main effects for both gender (20.9, 95% CI [15.7, 26.0] pounds, P < .001) and age (F(4, 454) = 6.143, P < .001, partial η² = .051). The highest weight-bearing tolerance was observed in males and individuals 25-34 years of age. Multiple regression analysis affirmed that gender, height and age categories of 45-54 and 55 to 64 were all statistically significant predictors of wrist weight-bearing tolerance, P < .01.

DISCUSSION

These results establish normal wrist weight-bearing tolerance values and demonstrate that gender, age and height are predictors of this weight-bearing tolerance.

CONCLUSION

These results could allow identification of pathologies associated with wrist instability.

The Triangular Fibrocartilage Complex In The Human Wrist: A Scoping Review Towards Uniform And Clinically Relevant Terminology

The aim of this scoping review was to assess the composition, terminology, and anatomy of the triangular fibrocartilage complex (TFCC) of the wrist and propose unambiguous terminology regarding the individual components. The review was conducted according to the methodological framework by Arksey and O'Malley (International Journal of Social Research Methodology, 2005, 8, 19–32). Electronic databases were searched from inception until September 1, 2021 for original anatomical studies, using MeSH terms and keywords on terminology and anatomy of TFCC components. Studies using gross dissections or macro‐ or microscopic histology were included. Animal studies, fetal studies and studies with unknown disease status, were excluded. A total of 24 studies were included. The articular disc, the radioulnar ligaments, the meniscus homologue and the extensor carpi ulnaris tendon (sub)sheath were unanimously classified as TFCC components. One study did not include the ulnolunate and ulnotriquetral ligaments and only one study did include the ligamentum subcruentum. The largest disagreement existed regarding the inclusion of the ulnar collateral ligament. Terminological ambiguity was seen in “triangular fibrocartilage,” “triangular ligament,” “igamentum subcruentum,” and the “proximal and distal lamina.” Anatomical ambiguity existed especially regarding the radioulnar ligaments, the ulnar attachments of the TFCC and the ulnar collateral ligament. Definitions of the individual TFCC components are redundant, ambiguous, and ill‐defined and therefore subject to different interpretations. In order to preclude confusion, consensus regarding terminology is recommended. We proposed a concise definition of the healthy TFCC that can be used as a starting point for future studies and current clinical practice.

Clinical evaluation of a wrist sensorimotor rehabilitation program for triangular fibrocartilage complex injuries

Introduction

Triangular fibrocartilage complex (TFCC) injuries are associated with distal radioulnar joint (DRUJ) instability and impaired wrist proprioception. Sensorimotor training of extensor carpi ulnaris (ECU) and pronator quadratus (PQ) can enhance DRUJ stability. With limited evidence on effectiveness of TFCC sensorimotor rehabilitation, this study aimed to evaluate the effects and feasibility of a novel wrist sensorimotor rehabilitation program (WSRP) for TFCC injuries.

Methods

Patients diagnosed with TFCC injuries were recruited from May 2018 to January 2020 at an outpatient hand clinic in Singapore General Hospital. There are four stages in WSRP: (1) pain control, (2) muscle re-education and joint awareness, (3) neuromuscular rehabilitation, and (4) movement normalization and function. WSRP also incorporated dart throwing motion and proprioceptive neuromuscular facilitation. Outcome measures included grip strength measured with grip dynamometer, numerical pain rating scale, joint position sense (JPS) measurement, weight bearing measured with the 'push-off' test, and wrist function reported on the Patient Rated Wrist Hand Evaluation.

Results

Ten patients completed the WSRP. Mean changes were compared with minimal clinically important differences (MCID) for outcomes. All patients achieved MCID on pain, 70% of patients achieved MCID on grip strength, weight bearing and wrist function. Paired t-tests and Cohen's D for outcome measures were calculated. There were large effect sizes of 2.47, 1.35, and 2.81 for function, grip strength and pain respectively, and moderate effect sizes of 0.72 and 0.39 for axial loading and JPS respectively.

Discussion

WSRP presents a potential treatment approach in TFCC rehabilitation. There is a need for future prospective clinical trials with control groups.

Wrist Injury in Deployed U.S. Marine-How to Maintain the Mission

Wrist pain commonly affects military members and while most instances are benign, some require urgent orthopedic attention to prevent permanent loss of function. A 27-year-old male Marine while deployed presented with wrist pain after a seemingly benign fall during recreation. Radiographs were initially read as unremarkable and treated as a sprain. Though when reviewed by the Shock Trauma Platoon physicians, a perilunate dislocation was noted. After unsuccessful closed attempts to reduce injury, the Marine was sent to orthopedic surgery and underwent open reduction internal fixation and required a subsequent closed reduction and percutaneous pinning. Perilunate dislocations are uncommon but are among the most severe types of wrist injuries. This case is a reminder that proper evaluation of all injuries is critical. Proper evaluation of wrist injuries includes an attentive physical exam and careful examination of the radiographs; paying close attention to Gilula arcs and collinearity of the radius, lunate, and capitate. Prompt recognition and referral to specialty care for definitive treatment are important to maximize functional outcomes.

Increase of weight-bearing capacity of patients with lesions of the TFCC using a wrist brace

STUDY DESIGN

Retrospective cross-sectional case series.

BACKGROUND

Lesions of the triangular fibrocartilage complex (TFCC) can result in pain during axial load and unstable distal radioulnar joint (DRUJ). Conventional wrist orthoses decrease initial pain sufficiently but also prevent any movement during recovery and do not contribute to the stabilization of the DRUJ.

PURPOSE

In this retrospective analysis, we tested if the weight-bearing capacity of patients with lesions of the triangular fibrocartilage complex was increased by wearing a brace that stabilizes the distal radioulnar joint.

METHODS

Twenty-three patients had an arthroscopically confirmed TFCC lesion. We compared preoperative dynamic weight-bearing capacity of both hands with and without a commercially available wrist brace (WristWidget). Subgroup analysis was performed for stability of the distal radioulnar joint and etiology of the TFCC lesion. The dynamic ulnar variance was measured in a modified weight bearing test. We used parametric tests for normally distributed values.

RESULTS

The weight-bearing capacity of the hand with TFCC lesion was significantly lower than of the control hand (16 verus 36 kg; p <0.001). The relative load of the affected hand compared to the unaffected hand increased from 48 % (CI 37-60, SD 27) to 59 % (CI 47-72, SD 29 with a brace. The device had no effect on the control hand. Twelve patients with unstable DRUJ had a lower weight-bearing capacity compared to the eleven with stable joint. The percentage improvement with bracing was higher for those with unstable joints (versus stable) and traumatic lesions (versus degenrative).

CONCLUSION

The use of a wrist brace significantly increases the weight-bearing capacity and therefore the maximum tolerated axial load of patients with a lesion of the TFCC. Patients with traumatic lesion or unstable DRUJ tend to show lower values than with degenerative lesions or stable joints.

MRI of the Wrist Ligaments

Technological advances in magnetic resonance imaging (MRI) have improved radiologists' ability to evaluate wrist ligaments. MRI interpretation often guides clinical management. This article aims to review the normal and pathologic appearance of intrinsic and extrinsic wrist ligaments with a focus on MRI. Variant anatomy, imaging pearls, and clinical significance are also discussed. Special attention is paid to key wrist ligaments that play a role in carpal stability.

[The ulnocarpal complex : New clinical and radiological considerations]

CLINICAL ISSUE

The triangular fibrocartilage complex (TFCC) is an anatomically complex structure with high demands on spatial and contrast resolution in imaging.

RADIOLOGICAL METHODS

The central, predominantly avascular articular disc can be distinguished from the ligamentous, vascularized periphery. Imaging methods include magnetic resonance imaging (MRI, preferably contrast-enhanced) as well as MR and computed tomography (CT) arthrography.

DIAGNOSTIC INNOVATIONS

While high-resolution MRI represents the standard diagnostic tool for the TFCC in general, arthrographic imaging is particularly useful for assessment of the foveal (proximal) lamina of the TFCC. In radiological reporting, the convergence of the TFCC periphery towards the ulnar styloid process and the ulnar fovea must be considered.

ACHIEVEMENTS

The Palmer classification is suitable for evaluating lesions of the articular disc, whereas the Atzei classification is superior for lesions of the ulnar TFCC insertions.

PRACTICAL RECOMMENDATION

Use of a high-resolution examination technique and anatomy-based image interpretation are important for reliable MRI of the TFCC.

Ulnar-Side Wrist Pain Management Guidelines: All That Hurts is Not the TFCC!

BACKGROUND

Ulnar-sided wrist pain is a common clinical problem, most often misdiagnosed as triangular fibrocartilage complex (TFCC) injury. It may be frustrating to the patient, as one may end up wearing a wrist splint for an unusually long period, disrupting their routine.

PURPOSE

Because of the dilemmas in the diagnosing the cause of ulnar-sided wrist pain, various algorithms have been suggested but it is an individual's choice to do a systematic assessment and follow in their routine clinical practice. We propose the 'storey concept' for examining the ulnar side of the wrist, with ulnar styloid as the reference point. The lower storey identifies the pathologies of the DRUJ, the intermediate storey identifies the pathologies of the radiocarpal joint and the upper storey identifies the pathologies of midcarpal and carpometacarpal joint.

CONCLUSION

Also, it is important to ramify the cause of pain into stable or unstable wrist, with or without arthritis, as this will guide us in managing the pain arising from distal radioulnar joint. In addition to methodical clinical examination, ideal radiographs and high-resolution MRI are critical to diagnose wrist pathologies. The role of wrist arthroscopy has consistently increased, and complements in both diagnosis and treatment of wrist pain especially in ambiguous situations.

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.

The Effect of the Powerball Gyroscope as a Treatment Device for Nonspecific Wrist Pain

OBJECTIVE

The aim of this study was to determine the effect of using the Powerball gyroscope as a treatment device on pain and change in endurance in nonspecific wrist pain.

METHODS

This study was a within-participants pre- and postintervention study consisting of 40 participants between ages 18 and 35 with an equal male-to-female ratio. The participants used the Powerball gyroscope for 5 minutes per treatment session. Treatment comprised 12 sessions carried out 3 × per week over a 4-week period. Participants completed objective and subjective data before the first, seventh, and 12th sessions. Objective data were recorded using the Jamar dynamometer to measure grip strength. Subjective data were gathered using the Patient-Rated Wrist Evaluation Questionnaire. Participants then used the Powerball gyroscope in the hand with the affected wrist. The Wilcoxon signed rank test and 1-way repeated-measures analysis of variance were used to analyze the changes.

RESULTS

A significant decrease in pain was noted throughout the study, but the most significant changes occurred between the seventh and 12th treatment sessions (P < .01). A significant increase in grip strength was also noted throughout the study, with the greater increase in grip strength occurring during the first 7 treatments (P < .02).

CONCLUSION

The Powerball gyroscope showed a change in outcome regarding nonspecific wrist pain and grip strength.

Solitary osteochondroma in the pisiform bone with pisotriquetal osteoarthritis. A case study

Osteochondroma is the most common bone tumour, which appears most commonly in the long bones. However, cases have been described in the scaphoid, capitate, lunate, trapezium, and trapezoid bones, which can be a cause of pain in the hand and wrist. Osteochondromas can occur concomitantly with other traumatic or degenerative processes or generate complications in adjacent structures. Below we present an osteochondroma in the pisiform bone associated with pisotriquetral osteoarthritis.

Evaluation of ulnar variance on wrist MR imaging: is it a reliable measure?

OBJECTIVE

To determine if ulnar variance can be evaluated by magnetic resonance (MR) imaging and if this measure can be used as a reliable indicator when correlated to the gold standard technique, conventional radiography (CR).

MATERIALS AND METHODS

From January to July 2018, the MR images of 64 participants, comprising 66 wrists (mean age 34.9 years; 33 females; 31 males), were obtained. Among those, 29 were referred for evaluation of the wrist for different medical reasons and 35 were asymptomatic volunteers from our radiology group. All subjects had a plain radiography of the wrist in a posteroanterior view with a mean interval between images of 1 day. Local ethics committee approved the study and written informed consent was obtained from all patients. Two musculoskeletal radiologists evaluated the images. Correlation coefficients and a linear regression model were used for statistical analyses.

RESULTS

Intra- and inter-observer analyses were performed for both diagnostic methods with results showing concordance (intra-observer: kappa score: MR 0.915/CR 0.931; p < 0.05; inter-observer: kappa score: MR 0.857/CR 0.931; p < 0.05). The intraclass correlations of MR and CR to evaluate agreement between the radiologists was slightly higher for radiologist #1 (0.771) than for radiologist #2 (0.659). A linear regression model showed good model fit indicating that MR does correlate with the ulnar variance as measured by CR (CR = 0.554 + 0.897 × MR, R² = 0.665).

CONCLUSION

Although CR is the gold standard method for the evaluation of ulnar variance, our study demonstrated that MR can be used as a reliable qualitative option.

Functional and Surgical Anatomy of the Upper Limb: What the Radiologist Needs to Know

The anatomy of the upper limb is complex and allows for exceptional functionality. The movements of the joints of the shoulder, elbow, and wrist represent a complex dynamic interaction of muscles, ligaments, and bony articulations. A solid understanding and of the characteristics and reciprocal actions of the anatomic elements of the joints of the upper limb helps explain the mechanisms and patterns of injury. This article focuses on the anatomy and functionality of the shoulder, elbow, and wrist, with emphasis on the stabilizing mechanisms, to set the foundation for understanding the occurrence of pathologic conditions.

Current perspectives in conventional and advanced imaging of the distal radioulnar joint dysfunction: review for the musculoskeletal radiologist

Distal radioulnar joint (DRUJ) dysfunction is a common cause of ulnar sided wrist pain. Physical examination yields only subtle clues towards the underlying etiology. Thus, imaging is commonly obtained towards an improved characterization of DRUJ pathology, especially multimodality imaging, which is frequently resorted to arrive at an accurate diagnosis. With increasing use of advanced MRI and CT techniques, DRUJ imaging has become an important part of a musculoskeletal radiologist's practice. This article discusses the normal anatomy and biomechanics of the DRUJ, illustrates common clinical abnormalities, and provides a comprehensive overview of the imaging evaluation with an insight into the role of advanced cross-sectional modalities in this domain.

Where Is the Ulnar Styloid Process? Identification of the Absolute Location of the Ulnar Styloid Process Based on CT and Verification of Neutral Forearm Rotation on Lateral Radiographs of the Wrist

Background

The location of the ulnar styloid process can be confusing because the radius and the hand rotate around the ulna. The purpose of this study was to identify the absolute location of the ulnar styloid process, which is independent of forearm pronation or supination, to use it as a reference for neutral forearm rotation on lateral radiographs of the wrist.

Methods

Computed tomography (CT) images of 23 forearms taken with elbow flexion of 70° to 90° were analyzed. The axial CT images were reconstructed to be perpendicular to the distal ulnar shaft. The absolute location of the ulnar styloid process in this study was defined as the position of the ulnar styloid process on the axial plane of the ulnar head relative to the long axis of the humeral shaft with the elbow set in the position for standard lateral radiographs of the wrist. To identify in which direction the ulnar styloid is located on the axial plane of the ulnar head, the angle between “the line of humeral long axis projected on the axial plane of the ulna” and “the line passing the center of the ulnar head and the center of the ulnar styloid” was measured (ulnar styloid direction angle). To identify how volarly or dorsally the ulnar styloid should appear on the true lateral view of the wrist, the ratio of “the volar-dorsal diameter of the ulnar head” and “the distance between the volar-most aspect of the ulnar head and the center of the ulnar styloid” was calculated (ulnar styloid location ratio).

Results

The mean ulnar styloid direction angle was 12° dorsally. The mean ulnar styloid location ratio was 1:0.55.

Conclusions

The ulnar styloid is located at nearly the ulnar-most (the opposite side of the humerus with the elbow flexed) and slightly dorsal aspects of the ulnar head on the axial plane. It should appear almost midway (55% dorsally) from the ulnar head on the standard lateral view of the wrist in neutral forearm rotation. These location references could help clinicians determine whether the forearm is in neutral or rotated position on an axial CT/magnetic resonance imaging scan or a lateral radiograph of the wrist.

MRI findings in bucket-handle tears of the triangular fibrocartilage complex

The triangular fibrocartilage complex (TFCC) is an intricate ligamentous and cartilaginous structure that helps transmit axial load across the wrist, and provide stability to the ulnocarpal and distal radioulnar joints (DRUJ). Because the blood supply to the TFCC varies depending on location, certain types of tears are more amenable to surgical repair than others. Since Palmer proposed his classification system of TFCC tears in 1989, only 1 case of a "bucket-handle" type tear has been reported. In this article, we describe two new cases of bucket-handle tears of the TFCC. In both cases, the torn fragment was displaced into a previously undescribed location (intra-articular DRUJ and prestyloid recess). Because this type of injury pattern has not been previously well characterized in the literature and such cases rarely reported, MRI findings have not been fully described and its implications on clinical management have largely yet to be determined.

Ulnar Styloid Base Fractures Cause Distal Radioulnar Joint Instability in a Cadaveric Model

BACKGROUND

The deep portion of the distal radioulnar ligaments (DRUL) inserts on the ulnar fovea and is the most important stabilizer of the distal radioulnar joint (DRUJ). Ulnar styloid base fractures that include the ulnar fovea may cause DRUJ instability.

METHODS

DRUJ stability in pronosupination was evaluated in 12 fresh-frozen upper extremities (4 female) aged 52 to 68 years (mean: 58.8 years) using a custom fixture, which allowed free rotation of the radius around the fixed ulna. Optical motion capture was used to record rotation of the radius with respect to the ulna. Each specimen was subjected to 3 N m of torque in both supination and pronation under 4 conditions: intact, ulnar styloid osteotomy with disruption of the foveal insertion of the DRUL, ulnar styloid fixation, and DRUL transection. Group differences were compared using a 1-way repeated-measures analysis of variance and Tukey multiple comparison post hoc tests.

RESULTS

When compared with the intact condition, both ulnar styloid osteotomy and DRUL transection significantly increased mean pronation (by 9.40° and 15.21°, respectively) and supination (by 9.05° and 17.42°, respectively) of the forearm. Screw fixation only significantly reduced pronation compared with osteotomy (by 2.62°). Screw fixation did not significantly affect supination.

CONCLUSIONS

Ulnar styloid fractures that disrupt the fovea cause instability of the DRUJ in pronation and supination under 3 N m of torque in a cadaveric model. Screw fixation of ulnar styloid base fractures achieves anatomic reduction; however, it only partially returns rotational stability acutely to the DRUJ and only during pronation.

MR imaging of the traumatic triangular fibrocartilaginous complex tear

Triangular fibrocartilage complex is a major stabilizer of the distal radioulnar joint (DRUJ). However, triangular fibrocartilage complex (TFCC) tear is difficult to be diagnosed on MRI for its intrinsic small and thin structure with complex anatomy. The purpose of this article is to review the anatomy of TFCC, state of art MRI imaging technique, normal appearance and features of tear on MRI according to the Palmar's classification. Atypical tear and limitations of MRI in diagnosis of TFCC tear are also discussed.

High-resolution 3T Magnetic Resonance Imaging of the Triangular Fibrocartilage Complex in Chinese Wrists: Correlation with Cross-sectional Anatomy

BACKGROUND

The injury of the triangular fibrocartilage complex (TFCC) is a common cause of ulnar-sided wrist pain. The aim of this study was to investigate if the high-resolution 3T magnetic resonance imaging (MRI) could demonstrate the detailed complex anatomy of TFCC in Chinese.

METHODS

Fourteen Chinese cadaveric wrists (from four men and three women; age range at death from 30 to 60 years; mean age at 46 years) and forty healthy Chinese wrists (from 20 healthy volunteers, male/female: 10/10; age range from 21 to 53 years with a mean age of 32 years) in Beijing Jishuitan Hospital from March 2014 to March 2016 were included in this study. All cadavers and volunteers had magnetic resonance (MR) examination of the wrist with coronal T1-weighted and proton density-weighted imaging with fat suppression in three planes, respectively. MR arthrography (MRAr) was performed on one of the cadaveric wrists. Subsequently, all 14 cadaveric wrists were sliced into 2 mm thick slab with band saw (six in coronal plane, four in sagittal plane, and four in axial plane). The MRI features of normal TFCC were analyzed in these specimens and forty healthy wrists.

RESULTS

Triangular fibrocartilage, the ulnar collateral ligament, and the meniscal homolog could be best observed on images in coronal plane. The palmar and dorsal radioulnar ligaments were best evaluated in transverse plane. The ulnotriquetral and ulnolunate ligaments were best visualized in sagittal plane. The latter two structures and the volar and dorsal capsules were better demonstrated on MRAr.

CONCLUSION

High-resolution 3T MRI is capable to show the detailed complex anatomy of the TFCC and can provide valuable information for the clinical diagnosis in Chinese.

Ulnar Neuropathy in Cyclists

The form and function of the cyclist exposes the ulnar nerve to both traction and compressive forces at both the elbow and wrist. Prevention of ulnar neuropathy and treatment of early symptoms include bike fitting, avoidance of excessive or prolonged weight-bearing through the hands, and the use of padded gloves. For persisting or progressive symptoms, a thorough history and physical examination is essential to confirm the diagnosis and to rule out other sites of nerve compression. The majority of compression neuropathies in cyclists resolve after appropriate rest and conservative treatment; however, should symptoms persist, nerve decompression may be indicated.

High-Resolution 3T MR Imaging of the Triangular Fibrocartilage Complex

This study is intended as a review of 3Tesla (T) magnetic resonance (MR) imaging of the triangular fibrocartilage complex (TFCC). The recent advances in MR imaging, which includes high field strength magnets, multi-channel coils, and isotropic 3-dimensional (3D) sequences have enabled the visualization of precise TFCC anatomy with high spatial and contrast resolution. In addition to the routine wrist protocol, there are specific techniques used to optimize 3T imaging of the wrist; including driven equilibrium sequence (DRIVE), parallel imaging, and 3D imaging. The coil choice for 3T imaging of the wrist depends on a number of variables, and the proper coil design selection is critical for high-resolution wrist imaging with high signal and contrast-to-noise ratio. The TFCC is a complex structure and is composed of the articular disc (disc proper), the triangular ligament, the dorsal and volar radioulnar ligaments, the meniscus homologue, the ulnar collateral ligament (UCL), the extensor carpi ulnaris (ECU) tendon sheath, and the ulnolunate and ulnotriquetral ligaments. The Palmer classification categorizes TFCC lesions as traumatic (type 1) or degenerative (type 2). In this review article, we present clinical high-resolution MR images of normal TFCC anatomy and TFCC injuries with this classification system.

Supination and Pronation Strength Deficits Persist at 2-4 Years after Treatment of Distal Radius Fractures

Forearm rotation is a key function in the upper extremity. Following distal radius fracture, residual disability may occur in tasks requiring forearm rotation. The objectives of this study are to define pronation and supination strength profiles tested through the range of forearm rotation in normal individuals, and to evaluate the rotational strength profiles and rotational strength deficits across the testing range in a cohort of patients treated for distal radius fracture associated with an ulnar styloid base fracture. In a normative cohort of 29 subjects the supination strength profile showed an increasing linear relationship from supination to pronation. Twelve subjects were evaluated 2-4 years after anatomical open reduction and volar plate fixation of a distal radius fracture. The injured wrist was consistently weaker (corrected for hand dominance) in both supination and pronation strength in all testing positions, with the greatest loss in 60 degrees supination. Mean supination strength loss across all testing positions was significantly correlated with worse PRWE scores, highlighting the importance of supination in wrist function.

Ulnar nerve entrapment at the wrist

Presentation of ulnar nerve entrapment at the wrist varies based on differential anatomy and the site or sites of compression. Therefore, an understanding of the anatomy of the Guyon canal is essential for diagnosis in patients presenting with motor and/or sensory deficits in the hand. The etiologies of ulnar nerve compression include soft-tissue tumors; repetitive or acute trauma; the presence of anomalous muscles and fibrous bands; arthritic, synovial, endocrine, and metabolic conditions; and iatrogenic injury. In addition to a thorough history and physical examination, which includes motor, sensory, and vascular assessments, imaging and electrodiagnostic studies facilitate the diagnosis of ulnar nerve lesions at the wrist. Nonsurgical management is appropriate for a distal compression lesion caused by repetitive activity, but surgical decompression is indicated if symptoms persist or worsen over 2 to 4 months.

The role of imaging in diagnosing diseases of the distal radioulnar joint, triangular fibrocartilage complex, and distal ulna

OBJECTIVE

The purpose of this article is to review the anatomy, biomechanics, and multimodality imaging findings of common and uncommon distal radioulnar joint (DRUJ), triangular fibrocartilage complex, and distal ulna abnormalities.

CONCLUSION

The DRUJ is a common site for acute and chronic injuries and is frequently imaged to evaluate chronic wrist pain, forearm dysfunction, and traumatic forearm injury. Given the complex anatomy of the wrist, the radiologist plays a vital role in the diagnosis of wrist pain and dysfunction.

Skeletal anatomy of the hand

The skeletal anatomy of the hand is composed of phalanges, metacarpal bones, and carpal bones. Its function is a product of the complex interactions between the power provided by the intrinsic and extrinsic musculature, the stability provided by the ligaments, and the structure provided by the bones, which serve as insertion and attachment sites for the muscles and ligaments. This article provides a detailed description of the skeletal anatomy of the human hand.

Distribution of primary osteoarthritis in the ulnar aspect of the wrist and the factors that are correlated with ulnar wrist osteoarthritis: a cross-sectional study

OBJECTIVE

The purpose of this cross-sectional study was to identify the distribution of primary osteoarthritis (OA) in the ulnar aspect of the wrist, and analyze the factors correlated with OA at this site.

MATERIALS AND METHODS

A total of 1,128 cases of skeletally mature Japanese patients were collected over a 3-year period. We analyzed the posteroanterior and lateral wrist radiographs of these patients for the presence of primary OA in the ulnar aspect of the wrist, including the distal radioulnar (DRUJ), radiolunate, ulnolunate, lunotriquetral, triquetrohamate, lunohamate, and lunocapitate joints. All joints were examined for the frequency of primary OA. Multivariate logistic regression was used to investigate the factors correlated with the presence of degenerative arthritis in the ulnar aspect of the wrist joint.

RESULTS

Primary OA of the ulnar wrist was identified in 145 out of 1,128 cases (12.8 %). Degenerative changes were most frequently identified in the DRUJ (12.3 %), followed by the ulnolunate joint (8.1 %). Variations in radial inclination (RI), carpal height ratio (CHR), and ulnar variance (UV) correlated with OA of the ulnar aspect of the wrist, with variations in UV showing the highest correlation.

CONCLUSION

Primary OA of the ulnar wrist was most frequent in the DRUJ and second most frequent in the ulnolunate joint. UV correlated most with OA in the ulnar aspect of the wrist.

Anatomical study of the pisotriquetral joint ligaments using ultrasonography

OBJECTIVE

The aim of this study was to demonstrate that ultrasonography may allow a precise assessment of the primary stabilizers of pisotriquetral joint (pisohamate, pisometacarpal, and ulnar pisotriquetral ligaments).

METHODS AND MATERIALS

This study was initially undertaken in eight cadavers. Metal markers were placed in the ligaments using ultrasonographic guidance, followed by the dissection of the wrists. High-resolution ultrasonography was then performed in 15 volunteers (30 wrists) for the analysis of the presence, appearance, and thickness of the ligaments.

RESULTS

At dissection, the metal markers were located in the ligaments or immediately adjacent to them, confirming that they were correctly depicted using ultrasonography. The three ligaments could also be identified in each volunteer. The optimal positioning of the probe and the dynamic maneuvers of the wrist allowing the strain of these ligaments could be defined. No significant changes in the appearance and thickness of the ligaments could be observed.

CONCLUSIONS

The three ligaments stabilizing the pisotriquetral joint can be identified using ultrasonography. Further studies are now required to know whether this knowledge may be useful in the assessment of pain involving the ulnar part of the wrist.

Bucket-handle tear of the triangular fibrocartilage complex: case report of a complex peripheral injury with separation of the distal radioulnar ligaments from the articular disc

Palmer previously proposed a classification system of triangular fibrocartilage complex (TFCC) injuries that proved to be useful in directing clinical management. However, dorsal peripheral tears (variants of class 1C) were not described and have rarely been reported in the literature since. We herewith present a rare case of bucket-handle tear of the TFCC. To our knowledge, this is the first case demonstrating partial separation of both the palmar and dorsal distal radioulnar ligaments (DRULs) from the articular disc. The particular wrist magnetic resonance (MR) arthrographic findings of this unusual complex peripheral TFCC tear (a variant of both class 1B and 1C) were nicely appreciated upon sagittal reformatted images.

Pitfalls that may mimic injuries of the triangular fibrocartilage and proximal intrinsic wrist ligaments at MR imaging

Diagnosis of injuries to the ligamentous structures of the wrist can be a challenge, particularly when there is involvement of the small, complex structures of the proximal wrist. Recent advances in magnetic resonance (MR) imaging, especially in spatial and contrast resolution, have facilitated more precise visualization of these structures. However, there are a number of pitfalls that may cause difficulty in diagnosis of injuries to the triangular fibrocartilage complex (TFCC), lunotriquetral ligament, and scapholunate ligament. Use of inappropriate MR imaging sequences and MR imaging artifacts may decrease the accuracy of diagnosis of injuries to the TFCC and wrist ligaments, whereas variant anatomy of the proximal wrist structures may mimic disease of the TFCC and wrist ligaments. Knowledge of the detailed anatomy of the wrist, as well as variant patterns of structure morphology and signal intensity, can help differentiate actual disease from normal or variant appearances at assessment with MR imaging.

Carpal tunnel: Normal anatomy, anatomical variants and ultrasound technique

The carpal tunnel is an osteofibrous canal situated in the volar wrist. The boundaries are the carpal bones and the flexor retinaculum. In addition to the medial nerve, the carpal tunnel contains nine tendons: the flexor pollicis longus, the four flexor digitorum superficialis and the four flexor digitorum profundus. Ultrasound (US) study of the carpal tunnel generally involves short-axis imaging of the tendons, and in the presence of disease, long-axis imaging and dynamic maneuvers are added. There are numerous reports of anatomical variants of the wrist involving vessels, nerves, tendons and muscles, and they can all be studied by US. Some are particularly relevant from a clinical point of view and will therefore be accurately described. The anatomy is complex, and the US operator should therefore be thoroughly familiar with the normal anatomy as well as the anatomical variants that may have a role in the pathogenesis of carpal tunnel syndrome or influence treatment.