Flexor tendon ruptures caused by an intraosseous ganglion of the hook of the hamate

Radiographic signs of hook of hamate fracture: evaluation of diagnostic utility

OBJECTIVE

Hook of hamate fracture, the most common swing-related wrist fracture, is commonly seen in high-level athletes. The fracture is rarely diagnosed on routine wrist radiographs, thus generally requiring CT or MR for diagnosis. Surgical excision has a high success rate, however diagnostic delay contributes to a high complication rate. Radiographic signs of hook of hamate fracture have been published, but uncertainty of the diagnostic accuracy limits application. The purpose of this study is to determine accuracy and interobserver reliability of radiographic signs of hook of hamate.

MATERIALS AND METHODS

This retrospective case-control study evaluated wrist radiographs of 50 patients, including 24 positive and 26 negative, for hook of hamate fracture, each proven by CT or MR. Five reviewers performed blinded, randomized evaluation of radiographs documenting whether the hook of hamate was normal or fractured, and if fractured, the radiographic signs present (ring sign, ghostly shadow, and diffuse sclerosis) and views that contributed to diagnosis.

RESULTS

Radiographic signs demonstrated high sensitivity (85%; 95% CI: 77-91), specificity (92%; 95% CI: 86-96), and accuracy (89%; 95% CI: 84-92) with substantial interobserver reliability (k = 0.652). The ring sign was the most sensitive radiographic sign. Diagnosis was most often supported by the oblique view (38%) and rarely the lateral view (15%).

CONCLUSIONS

Radiographic signs of hook of hamate fracture on routine radiographs can accurately and reliably diagnose hook of hamate fractures. Evaluation for discontinuity of the cortical ring will optimize sensitivity, allowing for timely diagnosis and treatment, and a reduction of complications.

Are Flexor Tendon Ruptures Ever Spontaneous? - A Literature Review on Closed Flexor Tendon Ruptures of the Little Finger

Background: When closed ruptures of flexor tendons of fingers occur, there is often an identifiable pathology, which should be addressed in the same surgical setting as the tendon repair. The concept of “spontaneous” tendon rupture, occurring in the absence of identified pathology, however, has also been reported in a significant number of papers. This controversy has prompted us to do a review of the existing literature.

Methods: We did a review of cases of closed ruptures of the flexor digitorum profundus (FDP) of the little finger in existing literature. Fifty-three publications were retrieved by searching “FDP tendon rupture” and “little finger” using PubMed database. We analyzed data such as the zone of rupture noted intra-operatively; and any precipitating factors, pathology or trauma. We also conducted a review on papers which discussed the concept of “spontaneous rupture”.

Results: Fifty-three publications were retrieved. There were 8 cases of ruptures in Zone I; 2 in Zone II; 30 in Zone III; 59 in Zone IV and 5 in Zone V. Majority of cases were associated with an element of trauma of varying severity, or pathology. A precipitating cause was not documented in 12 cases. Amongst all 36 cases of ruptures labelled as “spontaneous”, only 1 case was truly “spontaneous” without any associated trauma or pathology.

Conclusions: Most reports labeled as spontaneous rupture occurred in Zone III, where tendon ruptures are rare. There are documented pathological causes or evidence of trauma to most of these cases. We conclude these ruptures may have been mislabeled as spontaneous ruptures. Bearing in mind the propensity for tendon excursion, we suspect the lack of documentation of exploration in proximal zones contributed to this mislabeling. Understanding this concept of non-spontaneity to most tendon ruptures and the common sites of rupture or pathology is crucial for a surgeon to make strategic incisions and minimize future recurrence.

Hook of the Hamate: The Spectrum of Often Missed Pathologic Findings

OBJECTIVE

The purposes of this article are to review hook of the hamate anatomy, describe the imaging features of the spectrum of pathologic conditions, and discuss the pearls and pitfalls of imaging for clinical decision making for pathologic entities affecting the hook of the hamate.

CONCLUSION

Knowledge of the anatomy, imaging appearance, and clinical management of hook of the hamate abnormalities is important for radiologists in guiding the care of patients with ulnar-sided wrist symptoms.

Closed rupture of both flexor digitorum profundus and superficialis tendons of the small finger in zone II: case report

We report a rare case of closed rupture of both flexor digitorum profundus (FDP) and flexor digitorum superficialis tendons in zone II in the small finger. We performed delayed, primary end-to-end suture of the FDP and excision of the flexor digitorum superficialis, because myostatic contracture of the FDP tendon was not severe and the FDP tendon remnants were not frayed.

Spontaneous flexor tendon ruptures of the hand: case series and review of the literature

Spontaneous flexor tendon ruptures within the hand are incompletely understood. We report 5 cases of spontaneous tendon rupture involving the flexor digitorum profundus tendon. One case involves an abnormal intertendinous connection between the ring and small finger profundus tendons and another involves a lumbrical muscle variant. To our knowledge, the latter has not been reported in association with spontaneous tendon rupture. In reviewing the literature for spontaneous flexor tendon ruptures, a total of 50 spontaneous ruptures in 43 cases was found. The majority involve the profundus tendon of the small finger in the palm. The ruptures most often occur during periods of peak strain but can also occur without identifiable trauma. The pathogenesis of spontaneous tendon ruptures is still unclear and is likely multifactorial. Spontaneous flexor tendon ruptures of the hand occur more often than one might recognize.

Imaging of hamate bone fractures in conventional X-rays and high-resolution computed tomography. An in vitro study

RATIONALE AND OBJECTIVES

To examine the ability to image fractures of the body and hook of the hamate bone in conventional X-rays and high-resolution computed tomography (HR-CT).

MATERIALS AND METHODS

In an in vitro experiment using 18 cadaver hands, the hamate bone was fractured at different places. Before and after fracture, conventional X-rays were taken in different planes (anteroposterior, lateral, oblique, and carpal tunnel), and HR-CT was performed with 2-mm layer thickness in the axial, sagittal, and coronal plane.

RESULTS

Taking into account all the conventional X-ray projections applied, the in vivo experiment revealed a sensitivity of 72.2%, a specificity of 88.8%, and an accuracy of 80.5%. For the HR-CT, the sensitivity was 100%, the specificity was 94.4%, and the accuracy was 97.2%.

CONCLUSIONS

Fractures of the body and hook of the hamate cannot always be detected with certainty in the conventional X-ray image, even if different projectional planes are used. The HR-CT is the imaging procedure of choice for further clarification, and an axial or sagittal plane should be selected.