Prevalence and distribution of sesamoid bones in the hand determined using digital tomosynthesis

The Application of Sesamoid Position in Diagnosing Thumb Metacarpophalangeal Joint Dorsal Dislocation: A Retrospective Study

OBJECTIVES

The position of sesamoid of thumb metacarpophalangeal (MCP) joint changed clearly when the joint was dislocated dorsally. However, the significance of sesamoid location in diagnosing joint dislocation was unclear. The present study aimed to explore the positional relationship between sesamoid bone and thumb metacarpophalangeal joint in normal and dorsal dislocation joints.

METHODS

Between January 2018 and August 2023, we collected 60 isometric plain films from sixty outpatients and reviewed 56 anisometric plain films from twenty-eight emergency patients with dorsal dislocation of thumb MCP joint at Tianjin Hospital, then took measurements on the hand X-ray images. The sesamoid length on its longitudinal axis was defined as DP, the distance between the distal edge of sesamoid and thumb MCP joint was defined as DJ, and the ratio of DJ and DP was R. An independent-samples t-test and paired-samples t-test was utilized to analyze difference among data groups.

RESULTS

The 60 isometric images were from 30 male and 30 female outpatients with normal bone structure in their hands, and the 56 anisometric images of the 28 emergency patients included both preoperative and postoperative materials. Among the outpatients, the actual distance between the distal edge of sesamoid and thumb MCP joint space (DJ) was 2.09 mm and 1.40 mm in males and females, respectively. The authentic average length of sesamoid (DP) was 4.46 mm in males and 4.22 mm in females. The average value of R (the ratio of DJ and DP) in males and females was 0.49 and 0.34, respectively. There were gender-related statistical differences in DJ (p < 0.01) and R (p=0.01), but no statistical difference in DP (p > 0.05). For the 28 emergency patients, the mean value of R was -0.47 before joint reduction and 0.58 after joint reduction, with statistical difference between them (p < 0.01).

CONCLUSIONS

There was significant difference in the relative position between sesamoid and thumb MCP joint when joint dislocation and joint reduction. The distal edge of sesamoid beyond thumb MCP joint could be an evidence in diagnosing joint dorsal dislocation. The distal edge of sesamoid below thumb MCP joint could be an evidence of joint reduction.

Thumb Injuries and Instabilities. Part 1: Anatomy, Kinesiology, and Imaging Techniques of the Thumb

The unique anatomical characteristics of the thumb offer a broad range of motion and the ability to oppose thumb and finger, an essential function for grasping. The motor function of the thumb and its orientation make it particularly vulnerable to trauma. Pathologic lesions encountered in this joint are varied, and imaging techniques play a crucial role in injury detection and characterization. Despite advances in diagnostic accuracy, acute thumb injuries pose a challenge for the radiologist. The complex and delicate anatomy requires meticulous and technically flawless image acquisition. Standard radiography and ultrasonography are currently the most frequently used imaging techniques. Computed tomography is most often indicated for complex fractures and dislocations, and magnetic resonance imaging may be useful in equivocal cases. In this article, we present the relevant anatomy and imaging techniques of the thumb.

Prevalence of metacarpophalangeal sesamoid bones of the hand in Turkish population

OBJECTIVES

This study aims to investigate the prevalence and location of the metacarpophalangeal (MCP) sesamoid bones using computed tomography (CT) images.

PATIENTS AND METHODS

A total of 767 hands of 735 patients (503 males, 232 females; mean age: 36.9±17.0 years; range, 18 to 105 years) obtained from picture archiving and communication system were retrospectively analyzed between January 2016 and December 2019. The sesamoid bones of MCP joints I, II, III, IV, and V were recorded. Data including age, sex, side, number, pathologies, and location of the sesamoid bones were recorded.

RESULTS

The prevalence of sesamoid bones was found to be 100%, 37.61%, 1.17%, 0.5%, and 80% in MCP I, II, III, IV, and V, respectively. There was no significant correlation between the sex of the patient and presence of sesamoid bone at MCP II or MCP V (p>0.970 and p=0.176, respectively). The presence of sesamoid bone at MCP II was statistically significantly correlated with the presence of sesamoid bone at MCP V (p<0.001). There was no statistically significant difference in the side and sesamoid prevalence in the remaining 703 patients (p>0.05).

CONCLUSION

The prevalence of MCP V sesamoid bone is higher than previous studies from our country. The CT of hand can be used to determine sesamoid fractures and degenerative conditions of sesamoids.

Clinical value of digital tomographic fusion imaging in the diagnosis of avascular necrosis of the femoral head in adults

Background

To explore the clinical significance of digital tomographic fusion imaging in the diagnosis of avascular disease of the femoral head in adults.

Methods

Eighty-two adult patients with avascular necrosis of the femoral head confirmed by MRI in the department of orthopedics of our hospital were studied retrospectively. The related signs of adult avascular necrosis of the femoral head were diagnosed by digital tomographic fusion imaging, and the detection rates of digital X-ray (DR) and digital tomosynthesis (DTS) were compared to clarify the clinical value of digital tomographic fusion imaging in the diagnosis of adult avascular necrosis of the femoral head.

Results

DTS detected DR and 78 cases identified 55 cases. Taking the results of CT/MRI as the gold standard, the sensitivity, specificity, positive predictive value, and negative predictive value of DR and DTS in the diagnosis of ANFH were calculated. There was a significant difference in the detection rate between the two methods (P < 0.05).

Conclusion

The digital tomographic fusion imaging technique has the advantages of high detection rate and excellent image quality, is economical, and is worth popularizing. For those with negative X-rays, DTS diagnosis and CT or/and MRI can avoid unnecessary CT and MRI examinations, which is helpful to reduce the waste of medical resources.