Subcutaneous rupture of the tibialis anterior (TA) tendon has been reported predominantly in case reports and small case series because of the relative rarity of the injury. Unlike traumatic lacerations or open injuries to the tendon, subcutaneous injuries often go unnoticed by patients because of compensation by surrounding dorsiflexors of the foot and toes—namely, the extensor hallucis longus (EHL) and the extensor digitorum longus (EDL).1 This can delay presentation to an orthopedic surgeon and lead to difficulties in treatment, such as allograft or autograft being required if primary repair is no longer possible. Case reports and series have described treatment methods as well as anecdotal evidence of outcomes after operative repair or conservative treatment, but there have been no comprehensive systematic reviews of outcomes after various types of treatment. Authors have come to conclusions about expected outcomes based on patient age, time to treatment, treatment used, and other variables, but no reviews have examined these variables across multiple studies. Given the low level of the evidence presented in most of these reports, it is difficult to perform a meta-analysis of the data.
Instead, we systematically reviewed 87 cases from all pertinent studies and examined commonly reported data, such as patient age, time to treatment, treatment used, and outcome. Using the PICO (population, intervention, comparison, outcome) model for systematic reviews, we looked at patients who had closed, spontaneous, complete rupture of the TA tendon and underwent operative repair or conservative treatment of the injury. Outcomes surveyed included successful operative repair or conservative treatment, as measured by objective systems, such as MMSS (Manual Muscle Strength Scale) score, AOFAS (American Orthopaedic Foot and Ankle Society) hindfoot score, and FAOS (Foot and Ankle Outcome Score) testing, or by subjective description of posttreatment outcome.
We intend this review to serve as a guide for surgeons who find themselves treating a ruptured TA tendon, a relatively rare injury. They will be able to select the operative technique or conservative treatment that best matches the patient’s needs, based on comparison with previous case studies.
Materials and Methods
The cases reviewed for this study were found through a comprehensive PubMed search and an independent review of references cited in similar articles. Articles included were published between 1975 and 2012, inclusive. The latest search was performed on March 22, 2013. The search criteria were tibialis anterior [Title/Abstract] OR anterior tibial [Title/Abstract] AND rupture [Title/Abstract]) AND surgery. Only English-language articles, or articles already translated into English, were included. Eligible studies described cases of closed tendon rupture. No traumatic lacerations or open ruptures were included. If a study described both open and subcutaneous ruptures, only the subcutaneous cases were included. Further, partial ruptures were not included. In addition, ruptures caused directly by a known comorbid condition—for example, a rupture caused by a gouty tophaceous deposit at the site of rupture2—were not included. Data were extracted from publications independently and analyzed in a Microsoft Excel workbook (Microsoft, Redmond, Washington). Variables examined included patient age and sex, side involved, time to treatment, mechanism of injury, defect size, predisposing comorbidities, surgery or conservative treatment, type of operative repair (if applicable), graft used (if applicable), pretreatment function (by independent scoring system, if applicable), and posttreatment function. These variables were not necessarily reported in all the studies.
A potential bias exists in our PubMed search. As the query was specific for studies that included operative repair of a ruptured TA tendon, case studies that involved only conservative treatment were excluded. However, the primary goal of this review was to compare operative possibilities and the patient characteristics and outcomes associated with these surgeries.
Results
Figure 1 shows the criteria used to select eligible papers for review. Twenty-three papers matched the criteria.3-25 Data were independently extracted from these papers, as described in the Methods section. Again, not all variables were reported by all authors. Sammarco and colleagues21 reported time to treatment as a mean for 2 groups: 8 cases defined as “early” treatment (mean time to treatment, 0.625 months) and 11 defined as “late” treatment (mean time to treatment, 10.7 months). These mean times were therefore used independently for each case in calculating mean time to treatment for this systematic review.
Table 1 lists the demographics. There were 40 male and 25 female patients, and 22 cases in which sex was not specified. Mean age was 63.9 years (surgery group), 72.4 years (conservative treatment group), and 65.8 years (overall). Of the 87 patients, 72 underwent surgery, and 15 were treated with conservative measures.
