Comparison of distortion correction preprocessing pipelines for DTI in the upper limb

PURPOSE

DTI characterizes tissue microstructure and provides proxy measures of nerve health. Echo-planar imaging is a popular method of acquiring DTI but is susceptible to various artifacts (e.g., susceptibility, motion, and eddy currents), which may be ameliorated via preprocessing. There are many pipelines available but limited data comparing their performance, which provides the rationale for this study.

METHODS

DTI was acquired from the upper limb of heathy volunteers at 3T in blip-up and blip-down directions. Data were independently corrected using (i) FSL's TOPUP & eddy, (ii) FSL's TOPUP, (iii) DSI Studio, and (iv) TORTOISE. DTI metrics were extracted from the median, radial, and ulnar nerves and compared (between pipelines) using mixed-effects linear regression. The geometric similarity of corrected b = 0 images and the slice matched T1-weighted (T1w) images were computed using the Sörenson-Dice coefficient.

RESULTS

Without preprocessing, the similarity coefficient of the blip-up and blip-down datasets to the T1w was 0·80 and 0·79, respectively. Preprocessing improved the geometric similarity by 1% with no difference between pipelines. Compared to TOPUP & eddy, DSI Studio and TORTOISE generated 2% and 6% lower estimates of fractional anisotropy, and 6% and 13% higher estimates of radial diffusivity, respectively. Estimates of anisotropy from TOPUP & eddy versus TOPUP were not different but TOPUP reduced radial diffusivity by 3%. The agreement of DTI metrics between pipelines was poor.

CONCLUSIONS

Preprocessing DTI from the upper limb improves geometric similarity but the choice of the pipeline introduces clinically important variability in diffusion parameter estimates from peripheral nerves.

POINT-OF-CARE ULTRASOUND FOR GUIDANCE OF CLOSED REDUCTION OF FIFTH METACARPAL NECK (BOXER'S) FRACTURE

BACKGROUND

Ultrasound has been used previously in fracture identification, analgesia delivery, and fracture reduction for patients in the emergency department. It has not been previously described as a tool for the guidance of closed fracture reduction in fifth metacarpal neck fractures ("boxer's fractures").

CASE REPORT

A 28-year-old man presented with hand pain and swelling after punching a wall. Point-of-care ultrasound revealed a significantly angulated fifth metacarpal fracture, which was confirmed with a subsequent hand x-ray study. After an ultrasound-guided ulnar nerve block, closed reduction was performed. Ultrasound was used to assess reduction and ensure improvement in bony angulation during the closed reduction attempts. Post-reduction x-ray study confirmed improved angulation and adequate alignment. Why Should an Emergency Physician Be Aware of This? Point-of-care ultrasound has previously had efficacy in fracture diagnosis and anesthesia delivery for fifth metacarpal fractures. Ultrasound can also be used at the bedside to assist in the determination of adequate fracture reduction when performing closed reduction of a boxer's fracture.

Delayed motor weakness following peripheral nerve schwannoma resection: illustrative cases

BACKGROUND

Delayed facial palsy (DFP) after vestibular schwannoma resection is a well-documented, yet poorly understood condition. The exact pathophysiological mechanisms of DFP are unknown, although diminished intraoperative nerve response has been shown to be a prognostic factor. To date, no such condition has been described in regard to peripheral nerve schwannomas.

OBSERVATIONS

Here the authors present the first reported cases of delayed motor weakness (DMW) after peripheral schwannoma resection of the ulnar nerve at the elbow and peroneal nerve in the popliteal fossa. Both patients presented with a mass lesion and radiating paresthesias and had normal motor function preoperatively. Immediately after surgical resection, the patients had full strength. Within 24 hours, both patients exhibited marked weakness that gradually resolved over the course of several weeks.

LESSONS

DMW after peripheral schwannoma resection is a rare condition likely akin to delayed facial nerve palsy after VS resection. The mechanism of this phenomenon remains unknown, although symptoms appear to self-resolve with time. A better understanding of the processes driving this condition may allow for therapies that can expedite and improve long-term outcomes.

Clinical Study of Wrist Arthroscopy Combined with Oblique Ulnar Shortening Osteotomy in the Treatment of Ulnar Impaction Syndrome

Objective

To explore the clinical effects of wrist arthroscopy combined with oblique ulnar shortening osteotomy in the treatment of ulnar impaction syndrome.

Methods

This was a retrospective study of 60 patients with ulnar impaction syndrome who were admitted to our department from January 2016 to December 2019. According to different surgical methods, they were divided into an observation group and a control group, with 30 cases in each group. The control group was treated with oblique ulnar shortening osteotomy, and the observation group used wrist arthroscopy based on the control group. The two groups of patients were compared in terms of wrist function before and 12 months after surgery. We compared the Disabilities of the Arm, Shoulder, and Hand Score (DASH Score), Patient‐Rated Wrist Evaluation Score (PRWE Score), Visual Analog Score (VAS), and ulnar variation between the two groups at 12 months after surgery. The excellent and good rates by Mayo wrist score were compared between the two groups at the last follow‐up.

Results

All patients were followed up for 12–36 months, with an average of 14.5 months. Bone union was achieved at the oblique osteotomy of the ulna, with an average healing time of 13.6 weeks. The observation group was examined by wrist arthroscopy, and the triangular fibrocartilage complex (TFCC) Palmer classification was confirmed in three cases of type IIA, seven cases of type IIB, 14 cases of type IIC, and six cases of type IID. Compared with before surgery, the grip strength, flexion‐extension, ulnar radial deflection, and forearm rotation of the two groups of patients were significantly improved at 12 months after surgery. The DASH score, PRWE score, and VAS score of the observation group were better than those of the control group, and the difference in ulnar shortening length was not statistically significant between the two groups. The excellent and good rates of the observation group (93.3%) were better than those of the control group (87.5%) at the last follow‐up, and the difference was statistically significant.

Conclusion

Compared with oblique ulnar shortening osteotomy alone, combined wrist arthroscopy can better reduce the pain of patients with ulnar impaction syndrome, restore wrist function, and improve the excellent and good rates. Therefore, it is clinically worthy of promotion.

A case of distal limb arterial tortuosity and dilation: observations and potential clinical significance

Arterial tortuosity describes variation via bending of the arterial wall and has been noted in several arteries throughout the body. Tortuous blood vessels can cause nerve compression, as well as present difficulties to surgeons and radiologists. Here we present an unusual case of multi-vessel arterial tortuosity discovered in 78-year-old Hispanic male cadaver, independent of systemic pathology. The left ulnar and right tibial arteries were dissected, and using calibrated digital calipers, their external and internal diameters were measured both at the origin site and at the site of greatest dilation. Both wall thickness and the number of inflection points were also measured. Six bends were noticed in the ulnar artery and its diameter measured 8.11 mm at its widest, with a wall thickness of 0.88mm. On the lower extremity, the right tibial artery had three bends and its diameter measured 4.86 mm at its widest, with a wall thickness of 1.32 mm. This uncommon tortuosity is not only more prone to laceration during surgery, but the bending and thickening can be mistaken for tumors. Finally, fluid dynamics can be altered, resulting in an impact on blood pressure in the extremities. Thus, raising awareness is crucial to prevent both symptoms and iatrogenic complications.

Intraneural Lipoma of the Digital Nerve: A Case Report and Literature Review

Intraneural lipomas are rare soft-tissue tumors that can occur particularly within the median nerve. Even fewer cases have been reported of their occurrence within the ulnar nerve. These masses can cause compression neuropathies. In this report, we present the first documented case of an intraneural lipoma of an ulnar digital nerve.

Shear wave elastography of the ulnar nerve at the forearm

The study included 38 ulnar nerves in 20 healthy subjects. High-resolution ultrasound and Shear wave elastography were used to evaluate the ulnar nerve at the mid forearm. The mean cross-sectional area of the ulnar nerve was 7.1 mm2. The mean shear elastic modulus of the nerve in the short axis was 27.4 kPa. The mean shear elastic modulus of the nerve in long axis was 24.7 kPa. No statistical relation could be noted between elasticity measurements in long and short axes. The ulnar nerve elastic modulus also showed no correlation with CSA neither in the long axis nor short axis. Age, height, weight, and body mass index showed no correlation with the ulnar elastic modulus in short or long axes. The elastic modulus of the ulnar nerve has been determined in healthy subjects and can serve as a reference for future assessment of compressive neuropathies of the ulnar nerve.

Return to sporting activity after ulnar nerve transposition for isolated neuritis in competitive overhead athletes

BACKGROUND

Although ulnar neuritis can occur secondary to ulnar collateral ligament pathology, stress fractures, and traction apophysitis, isolated ulnar nerve dysfunction can lead to medial elbow pain. The purpose of this study was to evaluate the short-term outcomes of overhead athletes undergoing anterior ulnar nerve transposition for ulnar neuropathy.

METHODS

All overhead athletes who underwent isolated ulnar nerve transposition between 2009 and 2016 for refractory ulnar neuritis were identified. The primary outcome was return to sport, and secondary outcome measures included the Kerlan-Jobe Orthopaedic Clinic score; Mayo Elbow Performance Score; Quick Disabilities of the Arm, Shoulder and Hand score; Single Assessment Numeric Evaluation score; and visual analog scale score for pain. Complication and reoperation rates were recorded.

RESULTS

A total of 26 overhead athletes (21 male and 5 female athletes) underwent ulnar nerve transposition at an average age of 18.4 years (range, 11-25 years). Of the patients, 24 (92%) returned to their sporting activity at an average of 2.7 months postoperatively, including 16 (62%) at the previous level of play. The average visual analog scale pain score improved from 4.7 (±2.5) to 0.4 (±1.5) (P = .015). The average postoperative patient-reported outcome scores were as follows: Kerlan-Jobe Orthopaedic Clinic score, 80 (95% confidence interval [CI], 72.7-87.0); Single Assessment Numeric Evaluation score, 85 (95% CI, 75.4-94.7); Quick Disabilities of the Arm, Shoulder and Hand score, 5 (95% CI, 2.1-7.7); and Mayo Elbow Performance Score, 91 (95% CI, 86.8-96.0).

CONCLUSION

Cubital tunnel syndrome can cause medial elbow pain in overhead athletes in the presence of a normal ulnar collateral ligament. At mid-term follow-up, 92% of overhead athletes returned to sport after ulnar nerve transposition, with 62% resuming their previous level of performance.

Transosseous Suture Fixation of Avulsion Fracture of the Ulnar Collateral Ligament of the Thumb Metacarpophalangeal Joint

Acute traumatic avulsion or rupture of the ulnar collateral ligament (UCL) of the thumb metacarpophalangeal (TMP) joint is a frequent sports-related injury. If not diagnosed and treated early, it may lead to chronic instability, pain, and loss of pinch and grip strength and possibly osteoarthritis. UCL insufficiency may be treated by various techniques, such as bone anchors, transosseous sutures with or without a pull-out button, tendon grafts, or with TMP joint fusion in neglected cases with arthrosis. A simple technique of internal fixation of an avulsion fracture of the distal attachment of the UCL on the proximal phalanx of the thumb using transosseous sutures is described.

Nonoperative Treatment of Ulnar Carpometacarpal Fracture-Dislocations

Background  Ulnar carpometacarpal (CMC) joint dislocations and fracture-dislocations are uncommon injuries that are often overlooked. Most authors advocate surgical stabilization in order to prevent a secondary dislocation assuming that these injuries are inherently unstable. Case Description  This is a series of eight ulnar CMC joint dislocations and fracture-dislocations treated by closed reduction and splint immobilization after assessing the joint stability. Mean follow-up was 30.2 months, and minimum follow-up was 12 months. Satisfactory results were obtained in range of motion, grip strength, pain, DASH (Disabilities of the Arm, Shoulder and Hand) questionnaire, and time to return to working activities. In the same period, the closed reduction and cast failed two (20%) cases that were referred for surgery. Literature Review  There is little published literature on the nonoperative treatment of these injuries. Most of them are isolated case reports, whereas the largest series reports four cases. All of them have reported satisfactory results. Clinical Relevance  Based on our results, we believe that if the diagnosis of an ulnar CMC joint dislocation or fracture-dislocation is early accomplished and a concentric and stable reduction is initially achieved, the nonoperative treatment may be a successful option to take into account but requiring a close follow-up for the first week.

Radial Artery Access for Percutaneous Cardiovascular Interventions: Contemporary Insights and Novel Approaches

Since its introduction, the transradial access for percutaneous cardiovascular procedures has been associated with several advantages as compared to transfemoral approach, and has become the default for coronary angiography and intervention. In the last 30 years, a robust amount of evidence on the transradial approach has been mounted, promoting its diffusion worldwide. This article provides a comprehensive review of radial artery access for percutaneous cardiovascular interventions, including the evidence from clinical trials of transradial vs. transfemoral approach, technical considerations, access-site complications and limitations, alternative forearm accesses (e.g., ulnar and distal radial artery), and ultimately the use of the radial approach for structural interventions.

Ulnar Neuropathy at the Elbow Associated With Focal Demyelination in the Proximal Forearm and Intraoperative Imaging Correlation

Ulnar nerve focal demyelination (FD) in the forearm [defined as conduction block (CB) and or temporal dispersion (TD)] has been described with immune-mediated neuropathy and with compression affecting the forearm segment of the nerve. The association of FD in the forearm with entrapment ulnar neuropathy at the elbow, as well as the intraoperative imaging of the abnormal ulnar nerve at the flexor carpi ulnaris muscle level (FCU), has not been reported before. We report a 33-years-old woman presented with only sensory symptoms of the right hand suggestive of right ulnar neuropathy for the last 10 years. On clinical examination, she had reduced pinprick sensation on the little and ring fingers with no motor deficit. Nerve-conduction study showed slowing of conduction velocity across the elbow on the right when recording at the abductor digiti minimi (ADM) and first dorsal interossei (FDI). There was 63% amplitude drop when stimulating below the elbow compared to distal stimulation at the wrist. Increment inching study localized the block at 5 cm distal to the medial epicondyle. During surgical transposition, the ulnar nerve was swollen, and edematous in the segment where the nerve enters the FCU muscle, which provides a physiological explanation for the electrophysiological findings. After the surgery, the patient reported complete resolution of the symptoms. This case demonstrate that ulnar nerve motor potential FD at the proximal forearm could be recorded and it is still compatible with ulnar-nerve entrapment at the elbow.

Medial elbow anatomy: A paradigm shift for UCL injury prevention and management

To improve the management outcomes and diagnostic accuracy of the ulnar collateral ligament (UCL) injury, the anatomy of the medial side of the elbow joint is necessary to be understood in terms of the periarticular surroundings rather than the specific ligaments. The aim of this study was to anatomically clarify the medial side of the elbow joint in terms of the tendinous structures and joint capsule. We conducted a descriptive anatomical study of 23 embalmed cadaveric elbows. We macroscopically analyzed the relationship between the flexor pronator muscles (FPMs) and the joint capsule in 10 elbows, histologically analyzed in 6 elbows, and observed the bone morphology through micro computed tomography in 7 elbows. The two tendinous septa (TS) were found: between the pronator teres (PT) and flexor digitorum superficial (FDS) muscles, and between the FDS and flexor carpi ulnaris (FCU) muscles. These two TS are connected to the medial part of the brachialis tendon, deep aponeurosis of the FDS, and FCU to form the tendinous complex, which linked the humeroulnar joint and could not be histologically separated from each other. Moreover, the capsule of the humeroulnar joint under the tendinous complex had attachment on the ST of 7 mm width. The two TS, the brachialis tendon, the deep FDS and FCU aponeuroses, and the joint capsule linked the humeroulnar joint. These anatomical findings could lead to a paradigm shift in the prevention, diagnosis, and treatment of UCL injuries in baseball players. Clin. Anat. 32:379–389, 2019. © 2018 The Authors. Clinical Anatomy published by Wiley Periodicals, Inc. on behalf of American Association of Clinical Anatomists.

Ulnar paddlefish carpometacarpal dislocation of the three lesser fingers: a case report

The long fingers’ paddlefish carpometacarpal (CMC) dislocation is exceptional. Most dislocations occur after high energy trauma. Untreated, these lesions can result in chronic instability of the CMC joints and early osteoarthritis. We report the case of a 20-year-old patient presenting with an ulnar paddlefish CMC fracture-dislocation of the three lesser fingers resulting from a hand trauma in the context of an occupational accident. Treatment is usually surgical though no strict consensus can be found upon literature review. If diagnosed early and no associated fractures are found, CMC dislocation could benefit from conservative treatment.

The Accuracy of Ultrasonography in Detection of Ulnar Collateral Ligament of Thumb Injuries; a Cross-Sectional Study

INTRODUCTION

Timely diagnosis and treatment of traumatic injury to ulnar collateral ligament (UCL) of thumb is of special importance for preserving the full function of the hand. Therefore, the present study has been designed with the aim of evaluating the accuracy of ultrasonography in detection of these injuries.

METHODS

The present diagnostic accuracy study was performed on trauma patients over 15 years old who had clinical evidence of injury to UCL of thumb and were admitted to the emergency department. All patients were evaluated regarding injury to the mentioned ligament via ultrasonography and MRI and finally, the accuracy of ultrasonography in this regard was measured considering MRI as the reference test.

RESULTS

20 individuals with the mean age of 38.60 ± 13.45 (16 - 64) years were evaluated (60% male). Based on ultrasonography and MRI findings 7 (35%) individuals and 7 (35%), respectively had complete ligament rupture (kappa: 0.560 (95% CI: 0.179 - 0.942)). Sensitivity, specificity, positive and negative predictive value, and positive and negative likelihood ratio of ultrasonography in detecting injuries of the mentioned ligament were 71.42 (30.25 - 94.88), 84.61 (53.66 - 97.28), 71.42 (30.25 - 94.88), 84.61 (53.66 - 97.28), 2.5 (0.71 - 8.82), and 0.18 (0.04 - 0.67), respectively.

CONCLUSION

Based on the findings of the present study, performance of ultrasonography by a radiologist in the emergency department has 80% accuracy in detecting traumatic injuries of UCL of the thumb.

"False" Ligaments: A Review of Anatomy, Potential Function, and Pathology

This paper, although not an exhaustive review of "false" ligaments in the body, describes eight such ligaments. False ligaments are defined as ligamentous structures connecting separate parts of the same bone and are thus immobile. The ligaments reviewed include the suprascapular ligament, the transforaminal lumbar ligaments, the mamillo-accessory ligament, the transverse atlantal ligament, the transverse occipital ligament, the transverse humeral ligament, the coracoacromial ligament, and the transverse part of the ulnar collateral ligament. In this review, the anatomy and histological characteristics of each ligament are reviewed. Furthermore, possible functions and associated pathologies are described.

Motor Examination in the Diagnosis of Carpal Tunnel Syndrome

The relative importance and use of motor evaluation to diagnose carpal tunnel syndrome (CTS) is not clear. Because the ulnar nerve is not affected in CTS, we evaluated comparing the strength of the median-nerve innervated muscles to the ulnar innervated muscles in the same patient, through manual muscle testing (MMT) and a handheld dynamometer. Our purpose was to evaluate whether this method, which takes into account patient-dependent factors that would affect both groups of muscles equally, can provide better assessment of CTS. A retrospective case-control review of MMT and dynamometer-measured strength for CTS was performed. The study was performed retrospectively but prior to surgery or other treatment. There were 28 cases (CTS) and 14 controls (without CTS). Positive nerve conduction tests defined cases. MMT of the thenar musculature was found to be unreliable as a test for CTS. Comparisons to ulnar nerve innervated muscle strength did not improve sensitivity or specificity of the MMT examination. Use of the dynamometer improved sensitivity and specificity of motor testing in CTS over MMT. Motor evaluation is important for the diagnosis of CTS, but further study is warranted, specifically to define the method of motor evaluation and delineate the subgroup of patients (predominantly thenar motor presentation) that would benefit most from motor testing and motor-focused treatment.

Hypothenar hammer syndrome: long-term follow-up after ulnar artery reconstruction with the lateral circumflex femoral artery

In symptomatic patients with hypothenar hammer syndrome, the occluded part of the ulnar artery can be reconstructed with an autologous graft. Venous grafts are used frequently, but they are known for their low patency rate. Arterial grafts show better patency rates than venous grafts in coronary bypass surgery. We performed 11 ulnar artery reconstructions with the descending branch of the lateral circumflex femoral artery and compared these with previously performed venous reconstructions. All patients with an arterial graft reconstruction had a patent graft at a mean follow-up of 63 months. In addition, nine out of 11 patients reported improvement in their symptoms. The patency rate of venous reconstructions in hypothenar hammer syndrome is significantly lower. Arterial grafting for hypothenar hammer syndrome has superior patency compared with venous grafting; we recommend it as the surgical treatment of choice for symptomatic hypothenar hammer syndrome.

LEVEL OF EVIDENCE

4.

Superficial upper limb vasculature and its surgical implications

Any kind of anatomical variation whether encountered during cadaveric dissections or routine clinical or surgical procedures needs to be reported and taken into account. This can be quite helpful in planning surgeries accordingly and avoid disastrous complications. During routine cadaveric dissection, authors found a superficial course of arteries of the arm as well as the forearm, unilaterally in one cadaver. In this case, there were two brachial arteries – superficial and deep. Superficial brachial artery terminated into superficial radial and superficial ulnar artery. Deep brachial artery was trifurcated into common interosseous, medial and lateral artery branches. Authors have also discussed the developmental anomaly, which could have led to the observed morphological variation. Superficial vessels can provide large size pedicles for raising flaps for local reconstructive surgeries in the region of axilla, elbow, wrist or hand, or other regions.

Ring finger sensorial conduction studies in grading carpal tunnel syndrome

BACKGROUND

Comparing the distal sensory latencies of median and ulnar nerve over wrist-to-ring finger (RF) segment is a sensitive conduction parameter in the diagnosis of carpal tunnel syndrome (CTS). However to the best of our knowledge, there is not any research questioning whether the RF studies are useful in grading the CTS or not.

OBJECTIVES

To determine whether the hands with moderate degree CTS and elicitable median nerve sensory responses over second finger and unelicitable responses over RF represent a more severe electrophysiological grade than the hands with elicitable responses over both fingers.

MATERIAL AND METHODS

In patients with clinical diagnosis with CTS, obtained values on sensory and motor nerve conduction studies of median and ulnar nerves were compared between median nerve-to-RF sensorial responders (group 1) and nonresponders (group 2).

RESULTS

Seventy-four recordings belong to 59 patients with moderate degree CTS were included. There were 55 hands in group 1, and 19 in group 2. Mean sensory onset latency of median nerve over second finger was longer (4.17 ± 0.53 msec versus 3.47 ± 0.46 msec; p< 0.001), sensory conduction velocity was slower (34.1 ± 5.5 m/sec versus 40.1 ± 5.3 m/sec; p< 0.001), SNAP amplitude was smaller (7.0 ± 3.3 μ V versus 13.7 ± 6.7 μ V; p< 0.001), and distal motor latency was longer (5.75 ± 0.96 msec versus 4.76 ± 0.42 msec; p< 0.001) in group 2 than in group 1.

CONCLUSION

Median nerve-to-RF sensorial nonresponders have a more progressed compressive neuropathy, and represent a more severe electrophysiological grade than the responders.

Ultrasound guided distal peripheral nerve block of the upper limb: A technical review

Upper extremity surgery is commonly performed under regional anesthesia. The advent of ultrasonography has made performing upper extremity nerve blocks relatively easy with a high degree of reliability. The proximal approaches to brachial plexus block such as supraclavicular plexus block, infraclavicular plexus block, or the axillary block are favored for the most surgical procedures of distal upper extremity. Ultrasound guidance has however made distal nerve blocks of the upper limb a technically feasible, safe and efficacious option. In recent years, there has thus been a resurgence of distal peripheral nerve blocks to facilitate hand and wrist surgery. In this article, we review the technical aspects of performing the distal blocks of the upper extremity and highlight some of the clinical aspects of their usage.

Sonographic assessment of the medial ulnar collateral ligament distal ulnar attachment

OBJECTIVES

The purpose of this study was to determine whether the long distal attachment of the medial ulnar collateral ligament (MUCL) can be delineated on sonography.

METHODS

We used 12 fresh-frozen cadaveric elbows for this study. We performed sonography of the elbow using a coronal-equivalent long-axis view of the MUCL. All sonographic examinations and measurements were performed by a board-certified, fellowship-trained musculoskeletal radiologist. Measurements were performed from the anteroinferior aspect of the medial epicondyle to the sublime tubercle and then from the sublime tubercle to the terminal fibers of the MUCL long ulnar attachment. We then measured the length of the MUCL from its attachment at the medial epicondyle of the humerus to the sublime tubercle and then from the sublime tubercle to the distal extent of its terminal fibers at the ulnar attachment with digital calipers.

RESULTS

On sonography, the average length of the MUCL from its humeral attachment to the sublime tubercle (transarticular) was 19.6 mm. The average length of the ulnar attachment was 27.9 mm. The MUCL was thickest (mediolateral dimension) at its humeral attachment and tapered as it coursed distally along the ulnar attachment. The MUCL was clearly identified on sonography and in all anatomic specimens. On gross measurement, the average lengths of the transarticular portion of the MUCL and its ulnar footprint were 21.5 and 30.2 mm, respectively.

CONCLUSIONS

We have successfully shown that the distal ulnar attachment of the MUCL can be visualized on high-resolution sonography. This preliminary work provides a framework for developing protocols for diagnosis of injuries to the distal ulnar collateral ligament.

Use of a pedicled adipose flap as a sling for anterior subcutaneous transposition of the ulnar nerve

In patients with primary cubital tunnel syndrome, we hypothesize that using a vascularized adipose sling to secure the ulnar nerve during anterior subcutaneous transposition will lead to improved patient outcomes. The adipose flap is designed to surround the ulnar nerve with a pliable, vascularized fat envelope, mimicking the natural fatty environment of peripheral nerves. This technique may offer advantages in securing the anteriorly transposed ulnar nerve and reducing instances of postoperative perineural scarring. Patients experience good functional outcomes; most experience resolution of symptoms.

Ultrasound diagnosis of ulnar neuropathy: comparison of symptomatic and asymptomatic nerve thickness

There is still no consensus on a normal value for the cross-sectional area of the ulnar nerve at the elbow. Such data would be valuable for the ultrasound diagnosis of ulnar neuropathy. Comparison of the symptomatic and contralateral asymptomatic sides has been recommended. The aim of this study was to investigate whether or not the asymptomatic ulnar nerve could be a reference value. High-resolution ultrasonic measurements of the cross-sectional areas of the ulnar nerves at the elbow were compared with 38 contralateral asymptomatic elbows of patients with unilateral ulnar neuropathy and 38 healthy controls. There were significant differences in the cross-sectional areas at all levels between the healthy control subjects and asymptomatic side of the ulnar neuropathy patients (p < 0.05). The findings of this study suggest that there is a limitation in using the asymptomatic side for obtaining reference values in ultrasonographic studies. Each ultrasonographic laboratory should determine its own reference values.