CHAPTER 32 Tibialis Anterior Tendon Rupture: A Case Report James Uh, DPM Cameron Barr, MD INTRODUCTION weave technique. This patient had a predisposing factor that may have contributed to her rupture, which was the use of Closed rupture of the tibialis anterior tendon is a rare injury. local corticosteroids. However, she had no history of acute Bruning fi rst described it in 1905 and there have been fewer trauma to the area of her tibialis anterior tendon or any than 120 cases reported in literature since (1). The rupture other systemic factors that could have been attributed to can be a result of a direct, closed trauma without ankle her tibialis anterior tendon rupture. motion. However, it is more commonly associated with forced ankle plantarfl exion against resistance (1). It has also been CASE REPORT established that a normal tendon rarely ruptures. Conditions that increase the likelihood of rupture are systemic lupus A 70-year-old female presented to our clinic with complaint erythematosus, hyperparathyroidism, and psoriasis (2). Other of vague pain and weakness of 1 month duration that was factors may contribute to tibialis anterior tendon ruptures localized to the anterior aspect of her right ankle. She denied including metabolic disorders such as diabetes mellitus, gout, any history of trauma to the area. However, she did recall rheumatoid arthritis, or after local injections or chronic use that while walking normally that she felt a discomfort that of corticosteroids (1). The typical patient is a male older than was present to the anterior aspect of her ankle that presented the age of 45 years with a complaint of slapping of the foot as a popping type of sensation. Per the patient’s report, she during gait or frequent tripping. felt discomfort even before this popping sensation. Prior The tibialis anterior muscle is one of the strongest to this visit she had seen a different podiatric physician, dorsifl exors at the ankle joint. It provides up to 80% of the who injected her with some sort of unknown steroid dorsifl exory power (3). Extensor hallucis longus, extensor in the region of her anterior ankle prior to this popping digitorum longus, and peroneus tertius provide the rest sensation. However, following the injection she did not of the dorsifl exory force. The mechanism of rupture is notice any improvement in her pain and was continuing supination at the ankle joint and an abrupt plantarfl exion to have diffi culties in her daily activities. Her past medical against resistance (2). history was signifi cant for fi bromyalgia, hypothyroidism, Rupture of the tibialis anterior tendon can be subtle, and hypertension. thus a careful physical examination must be performed. At the time of presentation, it was noted that her right Patients diagnosed with rupture of this tendon often-present tibialis anterior tendon was not actively fi ring during gait weeks to years following the injury due to a relatively mild analysis compared to her contralateral unaffected side. On degree of pain (3). On physical examination there is mild seated examination, with active dorsifl exion there was noted pain to palpation at the insertion of the tendon. A tender to be a palpable void at the tibialis anterior near its insertion. bulbous mass is encountered, most commonly at the level of During manual muscle testing there was recruitment of her the ankle joint (3). The tendon is usually not palpable from extensor halluces longus tendon on the injured side with the point distal to its insertion. Another clue in diagnosing dorsifl exion. Compared to her uninjured side, the right foot a rupture is to have the patient dorsifl ex and invert the was noted to have less inversion. Light touch sensation was ankle. This would cause the tendon to become visible (in intact throughout her bilateral feet. She had brisk capillary a rupture the tendon is no longer visible), or palpable in refi ll time to her toes bilaterally. Subsequent magnetic the patient with closed rupture of the tendon. Extensor resonance imaging (MRI) revealed a complete tear of the substitution occurs in patients with tibialis anterior tendon patient’s tibialis anterior tendon at its insertion with 3-4 ruptures, in which the extensor digitorum longus, extensor centimeters of retraction (Figure 1). hallucis longus, and if present peroneus tertius compensate A discussion with the patient was had regarding for the loss of tibialis anterior tendon function during active treatment options for her pathology. The patient opted dorsifl exion of the ankle (1). for surgical intervention given that she had been dealing In this case report we present a rare case of an isolated with this for quite some time. Given the extent of the tibialis anterior tendon rupture in a 70-year-old female, patient’s rupture as seen on MRI, an end-to-end repair was detailing a unique surgical treatment involving the Pulvertaft 140 CHAPTER 32 Figure 1. Magnetic resonance image demonstrating rupture of the tibialis anterior tendon. Figure 2. Intraoperative view showing chronic scar tissue formation. to 250 mm Hg. A 12-cm incision was made along the anterior aspect of the ankle coursing over the dorsomedial aspect of the foot. This was positioned approximately 1 cm lateral to the course of the tibialis anterior, so as to try to minimize skin tension during the repair. After sharply coming through skin, blunt dissection was made down to the tendon sheath and extensor retinaculum. Care was taken to protect and retract the traversing branch of the superfi cial peroneal nerve. The tibialis anterior tendon sheath was then sharply incised. The extensor retinaculum was incised and marked for later repair. There was found to be a chronic rupture of the tibialis anterior just proximal to its insertion with retraction up above the level of the extensor retinaculum. There Figure 3. Intraoperative view following excision of scar tissue from the was extensive scar tissue that appeared almost tendon-like tibialis anterior tendon ends. traversing from the distal stump all the way to the proximal stump at the level of the ankle (Figure 2). Just proximal and determined not to be feasible. Thus the decision was made distal to this, was more normal appearing tendon. This scar to use a semitendinosus allograft. tissue was excised with a knife. This measured approximately The patient was brought back to the operating 6 cm in length. After removing this, there was more clear room suite where the anesthesiologist administered a representation of the tendon stumps (Figure 3). There was regional nerve block. Intravenous antibiotics were given no feasibility of end-to-end repair. for perioperative prophylaxis. An SCD was placed on the Dissection was carried down to the medial cuneiform. A contralateral limb for deep vein thrombosis prophylaxis. Beath pin was then driven from dorsal to plantar through the The patient was induced under general anesthesia. A well- medial cuneiform. Appropriate positioning and trajectory padded thigh tourniquet was placed high on the right thigh. was confi rmed under fl uoroscopy. A semitendinosus The right lower extremity was then prepped and draped allograft was then sized. A 6 mm drill hole was made over in the usual sterile fashion. A time-out was called and all the Beath pin. A whipstitch was placed through one end of those present confi rmed operative site, patient name, and the semitendinosus allograft and then it was brought up and procedure to be performed. An Esmarch bandage was used through the created drill hole through the medial cuneiform. to exsanguinate the limb and the tourniquet was insuffl ated One end of the allograft was brought up to the proximal CHAPTER 32 141 and a well-padded short-leg splint was applied. Care was taken to splint the ankle resting in approximately 10 degrees of dorsifl exion. Following surgery the patient was kept strict non- weightbearing for 6 weeks, followed by an additional 6 weeks of walking in a boot. At the patient’s 11 weeks postoperative visit, she was fully ambulatory in a CAM boot with no pain. On physical examination, she was able to actively dorsifl ex her ankle with fi ring of the tibialis anterior graft. At her 6 month postoperative visit she was fully ambulatory in regular shoes. She relayed some mild residual weakness but it was improved from her preoperative visit. She had no signifi cant pain to her right ankle. Manual muscle testing revealed 4/5 strength with dorsifl exion. There was no tenderness along the course of her tibialis anterior tendon. DISCUSSION Tibalis anterior tendon rupture is a rare injury, which may Figure 4. Intraoperative view demonstrating be the reason why the optimal treatment continues to semitendinosus allograft tenodesised with the distal remain a debate. It is generally accepted that surgical repair aspect of tibialis anterior tendon under tension utilizing the Pulvertaft weave technique. is warranted for the more active patients. While conservative treatment with casting and immobilization for patients with tendon stump. The more distal aspect of the allograft was a more sedentary lifestyle have yielded satisfactory results. then tied back onto itself, so that the tendon was secured Markarian et al found no difference when comparing the in and around the medial cuneiform. FiberWire (2-0) was results of 16 tibialis anterior tendon ruptures, in which 8 used to secure the tendon to itself. For added stability, a 5 were treated surgically and 8 were treated conservatively x 15 mm tenodesis screw was placed through the drill hole. (4). On the contrary, Ouzounian et al compared 12 tibialis It had excellent purchase and compression against the graft. anterior tendon ruptures, in which 7 were treated surgically With the distal aspect of the allograft secured, it was and 5 conservatively and found that the group that was then tensioned.