Closed Traumatic Rupture of Tibialis Anterior Tendon

Citation: Hui Chen, Gang-Rui Jia, Xin-Qiang Wang, Xin-Qiang Wang. Closed Traumatic Rupture of Tibialis Anterior Tendon. Biomed J Sci & Tech Res 34(5)-2021. BJSTR. MS.ID.005607.


Introduction
Closed rupture of Tibialis Anterior Tendon (TAT) is very uncommon. It not only be related to trauma, but also occurs spontaneously in tendons weakened by underlying chronic diseases, such as psoriatic arthritis, diabetes, gout, and local corticoid injection [1]. For a variety of reasons, early diagnosis of the closed traumatic rupture of the TAT is challenging We hear report such a closed TAT rupture combined with multiple fractures of ribs and discuss diagnosis and treatment of such a condition.

Case Report
A 50-year-old male patient came to the clinics with a chief complaint of weakened dorsal extension of the right foot and steppage gait. More than a month ago, he stumbled over the staires and felt an intense pain on his chest [2]. As the chest pain faded, he gradually experienced extension weakness in his right ankle, with occasional walking pain. Physical examination revealed mild swelling of the anteromedial malleolus. A mobile and painful soft mass could be touched at the joint level, while the most distal part of TAT was vacant [3]. Approximately 6 weeks later, ultrasound of the right ankle was carried out after the trauma, and the report was subcutaneous hematoma (Figure 1). At our clinic, 5ml light ischemic liquid was obtained from the pain point of right anterior ankle by manual syringe, then local area was compressed, but the "hematoma"  Delayed repair of the ruptured tendon was performed 42 days after the injury. An anteromedial approach along the route of the tendon was used. Exploration revealed that the inferior extensor retinaculum was partially broken, and the TAT ruptured from its insertion of cuneiform with the proximal stump retracted. There was no obvious pathological change in the end of the ruptured tendon. After an careful debridement, a mild defect about 1.0cm appeared at the insertion point of the tendon [4][5][6][7]. Silfverskiöld test was again performed to evaluate the contracture of gastrocnemius ( Figure 3). After the original insertion point was decortexed the TAT was fixed anatomically 5mm suture anchor ( Figure 4). Meanwhile, medial surface of the scaphoid was decortexed, and the tendon was fixed consecutively on the scaphoid by a 1.0cm spiked staple ( Figure   5). Inferior extensor retinaculum was repaired and the wound was then closed in layers with absorbable sutures. The ankle was immobilized in a short leg cast in maximum ankle extension for 6 weeks followed by protecting brace for another month. After the removal of the cast, rehabilitation was practiced [8]. Two and half months after surgery, the patient returned to full weight bearing.
Three months after surgery, his activity level of the right ankle was slightly less than previously, and there was a mild slapping gait. He denied pain in his right foot. Physical examination revealed that the tendon was palpable along its normal course and there was no tenderness. The AOFAS Scores was improved to 77.

Discussion
The tibialis anterior muscle is the major extensors of the ankle.
Covered with euangiotic sheathes, the tendon slides underneath the superior and inferior extensor retinaculum and inserts mainly into the medial aspect of the first cuneiform. Blood supply of the tendon tissue comes from the well vascularized peritendinous, and the avascular zone around the superior and inferior retinacula is prone to be ruptured [9]. Due to the existing avascularity, an osseous rupture of the tendon can also occur, but would be rarer in closed rupture. Because of the above mentioned blood supply anatomy, more attention to the intraoperative protection and repair of tendon tissue around is essential. Diagnosis of closed traumatic rupture of the TAT may be difficult. The patients often present a relatively mild pain for weeks to years following the injury [10].
When it is associated with other impairments, the rupture of the TAT is inclined to be neglected, especially with immobilization by cast Surgical intervention has shown fewer complications [3].
Although several surgical techniques of for TAT repaire have been reported, anatomic reconstruction is always emphasized.
Although repair by tendon grafting or free tendon transfer procedures obtains satisfied results, these methods remain additional risk of functional deficiency in the donor area. If the tendon contracture is not evident, primary repair may be accomplished by end-to-end suturing through a suture anchor or fixation through an osseous tunnel. Additional fixation on navicular bone by spiked staple is a way of adding a healing spot and partially decreasing bow-string potency. Decortexing is necessary for suture fixing through an anchor to promote tendon-bone healing.
Although possibility of gastrocnemius contracture within 6 weeks is minimal, Silfverskiöld test makes sense in surgical planning.
Once contracture of gastrocnemius is confirmed, achilles tendon loosening or lengthening should be performed. Repairs of the peritendineum and extensor retinaculum are very important.
Vascularized peritendineum is the main blood supply of TAT, which is also a sliding tissue to prevent adhesion. If the retinaculum is not repaired, bowstringing may occurre, and the strength will be weakened. Some authors [11] claimed that anatomical closure of the extensor retinaculum is associated with adhesion formation and restrictions, the open superior extensor retinaculum may free up the adhesions.

Conclusion
We report a 50-year-old male patient with the closed traumatic rupture of TAT. Early diagnosis of this condition is very difficult.
Early recognization of this rupture is very important for good function. This patient underwent surgical repair 6 weeks after the injury. A good function was obtained, despite the delay in surgical intervention. The authors propose that surgical technique should be performed through anatomy reconstruction as soon as possible.