Twenty consecutive patients with an anterior tibialis tendon rupture were managed between February 1988 and November 2005. During this time, two patients with limited functional demands were managed nonoperatively and were excluded from the present study. The remaining eighteen patients were managed operatively and were included in the study. The study group included eight women (eight ruptures) and ten men (eleven ruptures) with an average age of fifty-eight years (range, twenty-one to seventy-eight years). Ten ruptures involved the left leg, and nine involved the right leg.
The retrospective review of all cases included a review of the medical record, a final patient interview, and a physical examination at an average of 53.3 months (range, twenty-four to 180 months) after the date of surgery. The preoperative evaluation included a history and a physical examination that included gait assessment, manual strength testing of ankle dorsiflexion, and measurement of ankle range of motion. Manual strength testing was done with use of a 0 to 5 scale, with 0 indicating no evidence of contractibility, 1 (trace) indicating evidence of muscle contraction with no joint motion, 2 (poor) indicating range of motion with gravity eliminated, 3 (fair) indicating range of motion against gravity, 4 (good) indicating range of motion against some resistance, and 5 (normal) indicating range of motion against strong resistance22. An American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score was calculated at the time of the initial visit23. This 100-point standard rating system is designed for the comparison of the results of different methods of treatment in patients with the same disorder. It assigns 50 points for pain, 40 points for function (including gait, range of motion, and strength), and 10 points for alignment. This score is not validated.
The final postoperative evaluation was done by one of two authors (S.C. or C.H.) who were not present during the operation and did not participate in the postoperative care of the patients. The final evaluation included the calculation of a postoperative AOFAS hindfoot score and a physical examination that included manual testing of ankle dorsiflexion strength. Gait evaluation was also done by observing the patient walk barefoot toward and away from the examiner for a distance of 15 ft (4.6 m). A normal gait at the time of the latest follow-up was defined as a nonantalgic reciprocating gait pattern without a visible limp. The ability to heel-walk (to walk with the ankle dorsiflexed above 0°) for 15 ft (4.6 m) was also assessed.
The diagnosis of a tibialis anterior tendon rupture was made on the basis of a history and physical examination. All patients had functional complaints at the time of the initial evaluation, including a foot slap secondary to weak dorsiflexion or an unsteady gait, limping, and increased fatigue with walking. Six patients had pain at the site of the ruptured tendon. Physical findings were usually diagnostic and included the classic triad of (1) a pseudotumor at the anterior part of the ankle that corresponded with the ruptured tendon end, (2) loss of the normal contour of the tendon, and (3) weak dorsiflexion of the ankle accompanied by hyperextension of all of the toes (Fig. 1). Radiographs were made for all patients; these images showed glass fragments in one case but were otherwise unremarkable. Magnetic resonance imaging was used to define the extent of the injury and to confirm the diagnosis in all cases. Medical comorbidities were found to be present in ten patients with atraumatic ruptures. These included diabetes mellitus (one patient), gout (one patient with a bilateral rupture), hypothyroidism (two patients), psoriasis (one patient), osteoarthritis (two patients), chronic corticosteroid use (one patient), and hypertension (two patients). No patient with a traumatic rupture had an associated medical comorbidity.
A traumatic rupture was defined as a rupture that occurred as a result of direct blunt trauma or laceration to the tendon. An atraumatic rupture was defined as a rupture that occurred following a prodrome of swelling that either was spontaneous or followed a minor misstep or twisting injury to the ankle. The etiology was traumatic in the cases of three ruptures (including two that occurred as a result of laceration and one that occurred as the result of blunt trauma) and atraumatic in the cases of sixteen ruptures. Early repair (six weeks after the rupture or less) was performed for one traumatic and seven atraumatic ruptures; in these cases, the average time from rupture to surgery was 2.5 weeks (range, three days to six weeks). Delayed reconstruction (more than six weeks after the rupture) was performed for two traumatic ruptures and nine atraumatic ruptures; in these cases, the average time from rupture to surgery was 42.8 weeks (range, seven weeks to sixty months).
Of the eighteen patients, seventeen were available for the latest follow-up evaluation. One patient with a bilateral tibialis anterior tendon rupture died of unrelated causes four years after surgery; an AOFAS hindfoot score could not be calculated for this patient, but strength and gait data were well documented in the medical record and were included in the results.
Seven patients had been managed before the initial evaluation at our clinic. Two patients with lacerations had been managed by other physicians with closure of the skin wound alone and neglect of a complete tendon transection. One of these two patients had a 10-cm laceration that initially had been treated with irrigation and wound closure. She presented to us after six weeks with a grossly infected, dehisced wound and infection of the ankle. This patient had severe neurogenic pain at the time of presentation because of injury to the sensory branch of the deep peroneal nerve at the initial laceration site. One patient was referred to us three months after a primary repair of an iatrogenic tendon laceration that had been performed during a midfoot fusion. The tendon reruptured at the repair site once immobilization was discontinued. Three patients with an atraumatic rupture had been managed, by other physicians, with steroid injections of the dorsomedial aspect of the foot during the prodrome phase. One of these patients had been managed nonoperatively with immobilization in a splint and a boot walker but had persistent symptoms three months after the injury and elected surgical repair.
Surgical Technique
An intraoperative Silfverskiold test was performed to assess gastrocnemius tightness in all cases following the administration of a general anesthetic, and after complete muscle paralysis was achieved following intubation24. Ankle dorsiflexion was assessed with the subtalar joint held in neutral inversion-eversion, first with the knee in flexion and then with the knee in extension. A gastrocnemius recession was done if 5° of dorsiflexion could not be achieved when the knee was in full extension. The gastrocnemius recession was done through a small vertical midline incision placed just proximal to the myotendinous junction. Care was taken to identify and protect the sural nerve, which lies in the surgical field. The overlying aponeurosis of the gastrocnemius muscle was divided transversely while being held under tension by dorsiflexing the ankle. Care was taken not to divide the underlying muscle, and in no case was division of the soleus fascia performed. This procedure was performed in the case of one rupture that was treated with early reconstruction and in the cases of three ruptures that were treated with delayed reconstruction.
Next, an anteromedial incision overlying the tibialis anterior tendon was made, with the incision extending from the level of the medial cuneiform proximally to the level of the superior extensor retinaculum. Attempts were made to preserve the superior extensor retinaculum, when possible, to avoid adhesions of the repaired tendon to a repaired retinaculum. The proximal ruptured tendon end typically retracted to the inferior edge of this retinaculum or just beneath it. Complete release of the superior extensor retinaculum for exposure and repair was required in four cases, whereas only the inferior 2 cm needed to be released in fifteen cases.
If the tendon ends could be approximated or if the tendon could be brought to its insertion, the ends were freshened and a direct tendon repair was performed. In four cases, the tendon was repaired directly to bone with a suture anchor (ThRevo Suture Anchor; ConMed Linvatec, Largo, Florida) by placing the suture into normal tendon proximally with use of a locking technique25. One suture anchor was placed at the anatomic insertion of the tendon on the medial cuneiform or the medial aspect of the first metatarsal base, and, in cases in which the quality of fixation with a single anchor was uncertain, an additional anchor was placed in the dorsal aspect of the navicular. Direct repair was achieved in the cases of seven ruptures, including four that underwent early repair and three that underwent delayed reconstruction. If the tendon ends could not be approximated or if the tendon could not be apposed onto its insertion site, an interpositional tendon graft was used to bridge the gap and to reinforce the repair (Fig. 2). Autogenous tendon graft sources included the plantaris tendon (five cases), the extensor digitorum longus tendon (four cases), the peroneus tertius tendon (one case), and the Achilles tendon (two cases). A plantaris tendon graft was used preferentially. In the absence of the plantaris, alternate graft sites were selected on the basis of surgeon preference and the anatomy of the individual patient. When the extensor digitorum longus or peroneus tertius was used as the graft, 8 to 10 cm of tendon was harvested, and the remaining free segment of the distal part of the tendon was then sutured to the intact extensor digitorum communis tendons. The harvested grafts were of much smaller diameter than the tibialis anterior was; however, the defect that needed to be bridged was never >3 cm in length. This allowed the grafts to be folded two or three times to achieve a satisfactory overall diameter. In two cases, a preoperative magnetic resonance imaging scan revealed a plantaris tendon; however, at the time of surgery, the tendon was found to be of inadequate diameter. In these cases, a 4-mm-diameter graft was harvested from the Achilles tendon through the same incision with use of a blunt tendon harvester (ConMed Linvatec). A tendon graft was used in the cases of four early and eight delayed reconstructions. After reconstruction of the tendon, the extensor retinaculum was repaired to prevent bowstringing and adhesion of the reconstructed tendon to the subcutaneous tissue.
The patient was managed with immobilization in a short-leg cast with the ankle in 0° of dorsiflexion for four to six weeks. After three weeks, the patient was allowed to bear weight in the cast. The duration of cast immobilization was determined in part by the surgeon's perception of the quality of the repair at the time of surgery. In cases in which a primary repair was possible but tendon or bone quality seemed poor, and in all cases in which an intercalated graft was used, casting was maintained for six weeks postoperatively. Once the cast was discontinued, the patient was allowed to bear full weight in a boot with a hinged ankle joint (MaxTrax ROM Walker; DJO, Vista, California). Full dorsiflexion was allowed, but a stop prevented plantar flexion. Plantar flexion was gradually increased, and the boot was eventually discontinued ten to twelve weeks after surgery.
Statistical Analysis
Statistical analysis of the preoperative and postoperative AOFAS scores was performed with use of the paired Student t test. The level of significance was set at p < 0.05.
Source of Funding
There was no external funding for this study.
The average AOFAS hindfoot score (and standard deviation) improved significantly from 55.5 ± 19.7 points (range, 11 to 80 points) preoperatively to 93.6 ± 8.4 points (range, 65 to 100 points) postoperatively (p < 0.05). The average score for the early repair group improved significantly from 57.3 ± 15.7 points (range, 32 to 76 points) preoperatively to 96.1 ± 4.5 points (range, 88 to 100 points) postoperatively (p < 0.05). The average score for the late repair group improved significantly from 53.5 ± 22.7 points (range, 11 to 80 points) preoperatively to 91.8 ± 10.1 points (range, 65 to 100 points) postoperatively (p < 0.05). The sample size was too small to allow for statistical comparison of the means between early and delayed repairs, and the small differences seen may not be clinically important.
Normal ankle dorsiflexion strength (5/5 on manual testing) was present in fifteen ankles postoperatively, and a substantial improvement in strength was noted in comparison with the preoperative examination (Table I). The patient who presented with an infected wound had 3/5 strength and continued to have severe pain following delayed reconstruction despite a palpably intact reconstructed tendon and resolution of the infection. The pain in this patient was thought to be due to ongoing ankle arthritis, continued neurogenic pain, and dense adhesions of the extensor tendons. An ankle arthrodesis was offered, but further surgery was declined by the patient.
At the time of the latest follow-up, sixteen patients had a nonantalgic reciprocating gait pattern without a visible limp. The one patient who presented with an open wound and infection continued to have an antalgic gait with a decreased stance phase on the involved extremity secondary to pain. This gait pattern was unchanged from the preoperative status. One patient required the use of a walker because of hip and knee arthritis, which prevented an adequate gait assessment. All fifteen patients with 5/5 ankle dorsiflexion strength were able to heel-walk for at least a few steps, but only twelve patients were able to heel-walk for a distance of 15 ft (4.6 m). Two patients with 4/5 ankle dorsiflexion strength had continued hyperextension of the toes observed during gait, and both were unable to heel-walk.
Complications occurred in three patients. A partial wound dehiscence combined with cellulitis occurred in one patient who had undergone delayed reconstruction with an autogenous tendon graft. This patient was returned to surgery for incision and débridement and closure of the wound. Culture specimens that were obtained during surgery demonstrated growth of methicillin-resistant Staphylococcus aureus, and the patient was managed with intravenous vancomycin therapy for six weeks. The infection resolved, and the wound healed without further complication. Adhesions of the tendon to the extensor retinaculum and entrapment of the intermediate branch of the superficial peroneal nerve necessitated surgical release following one early reconstruction. At the time of the latest examination, the patient reported no residual pain, demonstrated 5/5 strength in dorsiflexion, and walked with a normal gait. One early repair of an atraumatic rupture had to be revised with the use of suture anchors and plantaris tendon graft three weeks later secondary to loss of tendon fixation.
Tibialis anterior tendon rupture was first described by Brüning in 1905 and is an uncommon finding12,20. A delay in diagnosis is common because of intact ankle dorsiflexion that occurs as a result of secondary function of the extensor hallucis longus and extensor digitorum communis muscles1,8,9,26. In the present series, the diagnosis was made at an average of 2.5 weeks after the onset of symptoms for the early reconstruction group and at an average of 42.8 weeks after the onset of symptoms for the delayed reconstruction group. The diagnosis is straightforward on the basis of physical examination alone, with all patients demonstrating weakness of ankle dorsiflexion and a palpable and visible defect of the subcutaneous portion of the tendon at the anterior part of the ankle and dorsal part of the foot. A palpable mass (pseudotumor) usually is present at the anterior aspect of the ankle; this mass corresponds with the retracted ruptured tendon end, which becomes entrapped at the distal extent of the superior extensor retinaculum. Ankle dorsiflexion in the involved extremity is weaker than that in the uninvolved extremity and is accomplished during walking by recruitment of the extensor hallucis longus and extensor digitorum communis, which then hyperextend the digits. A steppage gait is characteristic but is not universally present. In the present series, plain radiographs were of little benefit other than to identify a foreign body (glass) associated with a laceration in one case. We believe that magnetic resonance imaging can be useful for planning surgical reconstruction as it may show the presence of a peroneus tertius or plantaris tendon, which can be harvested if a graft is needed. Magnetic resonance imaging is of limited use for determining whether an intercalated graft will be necessary because this determination is made intraoperatively, primarily on the basis of the amount of excursion that is achieved after freeing the débrided tendon and muscle from adhesions.
We are not aware of any prospective studies in the literature regarding the treatment of tibialis anterior tendon ruptures. Most reports of tibialis anterior tendon rupture and its treatment have consisted of isolated case reports and small series1-7,9-17,19,26-29. The consensus in those isolated reports has favored early operative treatment with direct tendon repair to restore function in most patients, but recommendations have diverged when addressing treatment in the case of a neglected or delayed diagnosis.
Ouzounian and Anderson reviewed their clinical experience with twelve patients who had tibialis anterior tendon ruptures18. Two types of ruptures were identified on the basis of clinical presentation: (1) atraumatic ruptures, which occurred in low-demand older patients who presented late with minimal dysfunction and (2) traumatic ruptures, which occurred in higher-demand younger patients who presented earlier with more disability. The authors concluded (1) that patients with traumatic ruptures, regardless of the time of presentation, demonstrated better function after operative intervention and (2) that patients with atraumatic ruptures who present early should be managed surgically, whereas those with delayed presentation could be managed with bracing. Markarian et al. retrospectively reviewed the records of sixteen patients who had been managed operatively or nonoperatively for the treatment of a tibialis anterior tendon rupture10. The nonoperative treatment group was primarily made up of older, low-demand patients, whereas the operative treatment group tended to include younger, more active patients. The authors found a lack of significance between the operative and nonoperative treatment groups and attributed this finding to the age difference between the two groups. The authors recommended surgical reconstruction of the tendon for active patients and believed that nonsurgical treatment was appropriate only for elderly, low-demand patients with a delayed diagnosis.
In the current series, patients who were managed surgically both early and late had improvements in dorsiflexion strength and gait pattern and had a significant improvement in the AOFAS hindfoot score as compared with the preoperative value. It is our recommendation that tendon repair should be performed in all cases, regardless of age, when the patient is symptomatic with an unsteady or slapping gait or weakness and fatigability due to lack of dorsiflexion strength. Delay in diagnosis continues to complicate treatment. If the tendon cannot be directly approximated, a reconstruction with a tendon graft or an extensor hallucis longus tendon transfer are available treatment options9,10,29. Nonsurgical treatment seems to be poorly tolerated in younger active patients10.
In the current series, contracture of the gastrocnemius muscle was actively treated with a gastrocnemius recession in four cases. Doing so weakens plantar flexion strength, but it can restore muscle balance between dorsiflexion and plantar flexion and can protect the repair in the early postoperative period against reavulsion and later against recurrent tendon degeneration. We consider this to be an important part of the treatment of this condition when contracture of the gastrocnemius is present as shown by a positive Silfverskiold test.
Nonsurgical treatment and bracing should be reserved for elderly individuals with limited functional demands or for cases in which surgery may not be tolerated because of medical comorbidity. In the present study, the age of the patient was not taken into account when planning treatment. Rather, the patient's level of activity and functional deficits were the primary reasons for pursuing surgical repair to restore the primary ankle dorsiflexion tendon. Other authors have also reported good results in elderly patients with higher functional demands who are managed with surgical repair8,18. Dooley et al. recommended nonsurgical treatment for patients with a delay of diagnosis of more than three months8. In the current series, good results were noted despite a delay in diagnosis, although final function was somewhat impacted and the surgery was more complicated, often requiring a free tendon graft and sometimes a gastrocnemius recession.
The present study is limited by the use of the AOFAS hindfoot score as the clinical outcome measurement because this instrument is not validated. This score was selected because the primary motions affected by the tibialis anterior tendon (dorsiflexion-plantar flexion and inversion-eversion) are the motions that are included in the functional section of that score, and we believed that it was the best tool available at the time when the data were collected. There are also some limitations to our interpretation as only manual strength testing was done. As some patients with 5/5 strength were unable to heel-walk for 15 ft (4.6 m), it is likely that there is some permanent, subtle loss of strength and increased fatigability following surgical repair that is not shown by manual strength-testing alone.
The current series is also limited by its retrospective nature and by the lack of a control group of nonoperatively managed patients. The results cannot necessarily be extrapolated to all patients with tibialis anterior rupture as the current series represents only patients who were symptomatic at the time of presentation and were actively seeking treatment. The study demonstrates that symptomatic loss of the tibialis anterior tendon can be effectively treated with surgical repair. When reconstruction was delayed for more than six weeks, a higher number of complications were observed, but significant improvement was still noted. Therefore, we recommend that the functional deficit and the desired level of activity of the patient, rather than the time from the injury or the age of the patient alone, should be used as indicators for surgical repair. 