Anatomical Study of the Accessory Tendon of the Extensor Hallucis Longus Muscle and Its Clinical Application.

BACKGROUD: The accessory tendon of the extensor hallucis longus (ATEHL) muscle is a common abnormal structure, and its clinical significance remains debatable. In this study, we provide the incidence of the ATEHL and characterize its morphological types in Asian cadavers and investigate its clinical applications. METHODS: The tendons from 50 adult cadaveric feet, fixed in 10% formalin, were analyzed. We measured the length and width of both the ATEHL and the extensor hallucis brevis (EHB). RESULTS: All dissected specimens had an ATEHL. The first metatarsophalangeal joint was surrounded by an accessory tendon that inserted onto the joint capsule and the dorsal base of the proximal phalanx. We classified the ATEHL into 3 types based on their directions. Differences in ATEHL type based on sex were not statistically significant. CONCLUSIONS: We found an ATEHL in all cadaveric specimens in this study. We surmise that the ATEHL acts as an antagonist with the EHB when the toe is extending, which might help prevent the occurrence of hallux valgus deformity.

Modified Broström Procedure for Chronic Lateral Ankle Instability in Patients With Generalized Joint Laxity.

BACKGROUND: Generalized joint laxity (GJL) has been considered a risk factor for late failure of ligament reconstruction in the knee; however, it is not known whether GJL is the cause of recurrent instability after the modified Broström procedure for chronic lateral ankle instability. PURPOSE: To compare the clinical results of the modified Broström procedure for chronic lateral ankle instability in patients with or without GJL. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 100 patients (100 ankles) who underwent the modified Broström procedure were divided into 2 groups, with or without GJL, according to the Beighton criteria. Age and body mass index were matched between the 2 groups. The mean follow-up duration was 43.3 months in the laxity group (44 ankles; Beighton score ≥5) and 42.9 months in the nonlaxity group (56 ankles). RESULTS: The mean preoperative Karlsson and American Orthopaedic Foot and Ankle Society (AOFAS) scores were a respective 53.2 and 60.9 in the laxity group and 53.9 and 62.6 in the nonlaxity group, and these scores improved to 87.4 and 89.5, respectively, in the laxity group and to 94.1 and 94.8, respectively, in the nonlaxity group at final follow-up. The mean preoperative talar tilt angle and anterior talar translation were a respective 12.5° and 8.8 mm in the laxity group and 10.8° and 8.5 mm in the nonlaxity group, and these values improved to 7.3° and 6.0 mm, respectively, in the laxity group and to 5.2° and 5.0 mm, respectively, in the nonlaxity group at final follow-up. Failure rates were 11.4% (5 patients) in the laxity group and 1.8% (1 patient) in the nonlaxity group. Significant differences were found between the 2 groups in terms of the Karlsson score, AOFAS score, talar tilt angle, anterior talar translation, and failure rate at final follow-up (P < .05). CONCLUSION: Patients with GJL showed inferior outcomes and a higher failure rate compared with patients without GJL. Therefore, GJL appears to be a risk factor associated with recurrent instability after the modified Broström procedure.

Gender Differences in Outcome After Modified Broström Procedure for Chronic Lateral Ankle Instability.

BACKGROUND: The modified Broström procedure is commonly used for anatomic repair of chronic lateral ankle instability. However, no studies have compared outcomes of gender-based differences after the modified Broström procedure. We compared outcomes of the modified Broström procedure in men and women. METHODS: A total of 155 patients (155 ankles) treated with the modified Broström procedure for chronic lateral ankle instability constituted the study cohort. The 155 ankles were divided into 2 groups: a men's group (94 ankles) and a women's group (61 ankles). The Karlsson score, American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score, talar tilt, and anterior talar translation were used to evaluate clinical and radiographic outcomes. The mean follow-up duration was 42.8 months (range, 24-101). RESULTS: Mean preoperative Karlsson scores were 53.6 points (39-65) in the men's group and 54.9 points (39-65) in the women's group, and these improved to 93.2 (72-100) and 92.2 (80-100), respectively, at the final follow-up. Mean preoperative AOFAS ankle-hindfoot scores were 62.4 points (44-79) in men and 63.6 points (49-77) in women and 93.7 (72-100) and 92.3 (79-100), respectively, at the final follow-up. Mean preoperative talar tilt angles decreased from 11.9 degrees (2.5-27.5) in men and 11.4 degrees (0.9-24.7) in women to 6.0 (1.0-11.5) and 6.0 (2.3-11.9), respectively, at the final follow-up. Mean preoperative anterior talar translation in men and women improved from 8.6 mm (5.1-14.6) and 8.7 mm (2.3-11.9) to 6.0 (4.3-8.7) and 5.8 (3.3-9.9), respectively, at the final follow-up. No significant differences were found between men and women in terms of Karlsson scores, AOFAS scores, talar tilt angle, and anterior talar translation. CONCLUSIONS: The modified Broström procedure showed similar good functional and radiographic outcomes in men and women. These results suggest that the modified Broström procedure is effective and reliable for treating chronic lateral ankle instability regardless of gender. LEVEL OF EVIDENCE: Level III, retrospective comparative cohort study.

Neurologic injuries after primary total ankle arthroplasty: prevalence and effect on outcomes.

BACKGROUND: Neurologic injuries are complications that can arise after total joint arthroplasty. However, no comprehensive study has been conducted on peripheral nerve injuries after total ankle arthroplasty. The purpose of the present study was to identify the prevalence of neurologic injury following primary total ankle arthroplasty, the predisposing factors, and evaluate the effect on clinical outcomes. METHODS: We retrospectively analyzed 150 consecutive primary total ankle arthroplasty using the mobile-bearing prosthesis between January 2005 and December 2011, in 150 patients with symptomatic ankle end-stage arthritis. All the patients were divided into groups according to whether they had postoperative peripheral neuropathy (23 patients) or not (127 patients). We investigated the prevalence, predisposing factors, and effect on clinical outcomes of neurologic injuries. The mean age was 61.3 years, and the mean follow-up period was 41.8 months. RESULTS: There were 23 nerve injuries (15.3 %), including nine in posterior tibial nerves, six superficial peroneal nerves, six deep peroneal nerves, one saphenous nerve, and one sural nerve. Neurologic injury was significantly associated with the development of posttraumatic osteoarthritis, but it was not significantly associated with other predisposing factors, such as age, gender, body mass index, and symptom duration. Of the 23 nerve injuries, 13 (56.5 %) presented a complete, spontaneous recovery, 9 (39.1 %) presented an incomplete recovery, and 1 (4.3 %) presented no recovery. The patients with neurologic injury had significantly lower American Orthopaedic Foot and Ankle Society scores and lower levels of patient satisfaction. CONCLUSIONS: The results of this study suggest that the prevalence of neurologic injury after total ankle arthroplasty is considerable, and that neurologic injury is associated with low levels of patient satisfaction and poor clinical outcomes at mean of 3 years, postoperatively. Care is needed to reduce the occurrence of neurologic injuries.