Cadaveric Analysis of the Distal Tibiofibular Syndesmosis

BACKGROUND

Unstable ankle fractures with syndesmotic injuries commonly occur and can result in significant morbidity. Although the need for an anatomic reduction is clear, there is still debate surrounding the optimal operative treatment. Recent literature shows an increasing interest in anatomic ligament repair or reconstruction in the acute and chronic syndesmosis injury. Despite this trend, there is insufficient literature detailing anatomy of the distal tibiofibular syndesmosis. In the literature that does exist, there is controversy regarding the ligamentous anatomy of the syndesmosis. None of the current literature describes an anatomic constant that may be used as an intraoperative reference for anatomic ligament reconstructions.

METHODS

Ten sets of tibia and fibula free of all soft tissue were used to analyze osseous structures. Another 10 nonpaired, fresh-frozen specimens were used to study the distal tibiofibular syndesmosis. These were measured using a 3-dimensional tracking system. Measurement of each ligament width at origin and insertion, length, and distance from the tibial articular cartilage was performed.

RESULTS

The superior and inferior insertions of the anterior inferior tibiofibular ligament measured 22.7 mm and 3.4 mm proximal to the distal articular cartilage of the tibia, respectively. The superior insertion of the posterior inferior tibiofibular ligament measured 15.2 mm proximal to the articular cartilage. The superior and inferior insertions of the interosseous ligament measured 31.8 mm and 9.2 mm proximal to the distal articular cartilage, respectively. The inferior transverse ligament was a prominent identifiable structure in 70% of specimens.

CONCLUSIONS

The superior margin of the distal articular cartilage could serve as a consistent anatomic landmark for reconstruction. The inferior transverse ligament is an identifiable structure in 70% of the specimens studied.

CLINICAL RELEVANCE

This article clarifies the anatomy and provides measurements from an anatomic constant that can guide reconstruction and intraoperative evaluation of the syndesmosis.

Prophylactic appendectomy: unnecessary in children with incidental appendicoliths detected by computed tomographic scan

PURPOSE

Controversy exists regarding the clinical significance of an isolated appendicolith on computed tomographic (CT) scan. We sought to determine the risk of developing appendicitis in children with an incidentally noted appendicolith.

METHODS

We retrospectively reviewed all pelvic CT scans in patients 18 years or younger at a tertiary care children's hospital from October 2005 to September 2008. Patients with an appendicolith and no radiographic evidence of acute appendicitis were selected for further review. Written questionnaire and telephone follow-up were attempted in all patients.

RESULTS

Two thousand nine hundred thirteen pelvic CT scans were performed during the study period. The incidence of an isolated appendicolith during the study period was 2.6% (n = 75). Seven patients underwent appendectomy at initial presentation. Nine children underwent appendectomy subsequently: 3 electively and 6 at the time of return with abdominal pain. Only 6 of these 16 appendectomy specimens had histologic evidence of appendicitis, whereas only 3 demonstrated an appendicolith. Subsequent appendicitis developed in 5.8% (n = 4) of patients with an isolated appendicolith. Follow-up was achieved in 50% of patients who did not have an appendectomy (median, 2.8 years).

CONCLUSION

Children with an incidental appendicolith are at low risk for developing appendicitis. The appendicoliths were often a transient finding not confirmed on surgical pathologic condition or subsequent imaging.