Ligaments of the os trigonum: an anatomical study

Purpose The aim of the study was to examine the ligaments of the os trigonum. Methods The ankle joint magnetic resonance imaging (MRI) of 104 patients with the os trigonum (experimental group) and 104 patients without the os trigonum (control group) were re-reviewed. The connections of the os trigonum and posterior talofibular ligament (PTFL), the fibulotalocalcaneal ligament (FTCL), the paratenon of the Achilles tendon, the posterior talocalcaneal ligament (PTCL), the osteofibrous tunnel of the flexor hallucis longus (OF-FHL) and the flexor retinaculum (FR) were studied. Results The os trigonum is connected to structures. The posterior part of the PTFL inserted on the os trigonum in 85.6% of patients, whereas in all patients in the control group, the posterior part of the PTFL inserted on the posterior talar process (p < 0.05). The connection of the PTCL was seen in 94.2% of patients in the experimental group, while it was seen in 90.4% of patients in the control group (p > 0.05). The connection to the FTCL in the experimental group was 89.4%, while in the control group, it was 91.3% (p > 0.05). The communication with the paratenon was seen more often in the control group compared to that in the experimental group (31.7% vs. 63.8%, p < 0.001). The FTCL was prolonged medially into the FR in 85.6% of patients in the experimental group and in 87.5% of patients in the control group (p > 0.05). The flexor hallucis longus (FHL) run at the level of articulation between the os trigonum 63.5% and the posterior process of the talus 25% and less often on the os trigonum 11.5%. Conclusion The os trigonum is connected with all posterior ankle structures and more connections than previously reported.

Posterior Talofibular Ligament: The Relationship between its Length and Talar Morphometric Profiles

Category: Ankle, Sports Introduction/Purpose: Posterior talofibular ligament is one of the lateral ligamentous complex of the ankle. However, little is known about its anatomic profile especially on the relationship between its length and the morphometric profiles of talus. The present was to analyze the correlations between PTFL length and the talar morphometric profiles in the cadaveric specimens. The PTFL variation was also reported in this study. Methods: A total of twenty four cadaveric ankles as twelve matched pairs of ankle were collected in this study. All ankles were measured with a Vernier caliper which provided the data for further analysis regarding the PTFL length and the talar morphometric profiles. The data was calculated to demonstrate the relationship between PTFL length and the morphometric profiles of talus. There was a cadaveric ankle which was not used in the study due to its absence of PTFL. Results: An average length of PTFL was 23.9+/-6.9 mm. In overall, an average talar length (TaL) was 53.5 millimeters (mm). An average talar dome height (TaH) was 31.2 mm. An average talar body width (TaW) was 41.3 mm. The average anterior trochlear width (TrAW), middle trochlear width (TrMW), posterior trochlear width (TrPW), and trochlear length (TrL) were 31.8, 31.2, 28.3, and 30.7 mm. Based on twenty three ankles, the paired samples T-test showed the significantly negative correlations between PTFL length and TrL (Pearson’s r correlation coefficient: -0.432; P-value: 0.039). Other correlations were in negative values but P-values > 0.05. There were 16 ankles (84.2%) with 1 PTFL band and 3 ankles (15.8%) with 2 bands from 19 ankles with complete data. Conclusion: The present study may be a first study which delineates the relationship between PTFL length and the morphometric profiles of talus. The PTFL length was negatively correlated with talar size especially on the trochlear length of talus.

Posterior Ankle and Hind Foot Arthroscopy

Objectives: While anterior ankle arthroscopy is a widely accepted technique, posterior ankle/hind foot arthroscopy is still a relatively new procedure. The arthroscopic visualisation was often initially limited and vulnerabilty of the posteromedial neurovascular structures to injury scared orthopaedic surgeons. The goal of this review is to highlight the indications, and to present the long term follow up results of posterior ankle/hind foot arthroscopy. Methods: The study included 21 ankles in 21 patients (12 male and 9 female ).The mean age was 37.7 , the mean duration of preoperative symptoms 12.8 months . Arthroscopy performed with the patient prone , under general and spinal anesthesia with tourniquet hemostasis . Preoperative intravenous antibiotic prophylaxis is performed (cefazolin 1g) , sand bag placed under ipsilateral anteresuperior iliac spine to correct natural external rotated posture of the ankle and ankle is left hanging of the table so that it can moved freely during surgery. We applied noninvasive distraction method with simple rope which tied and knotted waist of the surgeon . The posterolateral and posteromedial portals which described by Van Dijk was utilized . The arthroscopic visualisation was often initially limited and careful debritement of some adipose tissue of the kager fat pad (Kager's fat pad, also known as the pre-Achilles fat pad) was necessary to create more space to aid visualization .The most valuable point to stay clear from trouble is to understand , know and aware where the flexor hallucis longus tendon exist .So neurovascular structures located beyond this tendon. Principally the process must advance into lateral to medial manner. The mean follow up period was 55 months. The most common preoperative diagnoses were osteochondral lesions of talus (ten ),painful os trigonum syndrome with (five )or without (three) FHL tenosynovitis (total eight ), posterior talofibular ligament thickenning (two ), Haglund’s deformity (one ) Results: The mean pre operative AOFAS score was 50.75, the mean post operative AOFAS score was 93.75. Complications were noted. Complex regional pain syndrome (CRPS) and oedema was diagnosed during early post operative period in one patient (%4.7), resolved with physical therapy. Conclusion: The most common procedures were osteochondral lesion debritement and curettage with multidrilling /microfracture (10), isolated os trigonum excision (2), tenolysis of the flexor hallucis longus tendon with os trigonum excision (6 ), debritment of the thickened posterior talofibular ligament (2), endoscopic partial calcanectomy for Haglund’s deformity (1) . Our experience demostrated that posterior ankle and hind foot arthroscopy can be performed with low rate of major postoperative complication.