Calcaneofibular Ligament Research Articles

Preliminary Results of Calcaneofibular Ligament Transfer for Recurrent Peroneal Subluxation in Children and Adolescents

Subluxation of the peroneal tendons over the lateral malleolus is an uncommon condition in both pediatric and adult populations. The primary dislocation is thought to occur with rupture of the superior peroneal retinaculum and may be associated with marginal fractures of the lateral malleolus or a preexisting shallow groove inferiorly. Various operative techniques have been reported earlier, but little data exists regarding surgical management and outcome in a pediatric and adolescent population with open physes. A retrospective review of patients presenting to our institution over a 5-year period yielded 9 cases of recurrent peroneal subluxation refractory to nonoperative management in 7 children or adolescents (mean age 12 y). Both traumatic and atraumatic etiologies were represented. All patients failed nonoperative treatment and were treated operatively with calcaneofibular ligament (CFL) transfer to reroute the peroneal tendons underneath the CFL. All patients were observed in follow-up and sent validated outcomes questionnaires, including the Foot and Ankle Ability Measure and the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale. Mean clinical follow-up was 20.9 months (range: 12 to 35 mo). At follow-up, all patients had returned to sports and activity and there were no instances of recurrence of subluxation. Complications included 1 postoperative infection and 1 patient requiring revision surgery for fibrosis. Six of 9 ankles (66.6%) returned the outcomes surveys. The average Foot and Ankle Ability Measure activities of daily living score was 90.8 (±4.4) and the sports subscale was 62.5 (±9.3). The mean American Orthopaedic Foot and Ankle Society score was 86 (±3.2). Peroneal subluxation is an uncommon condition in pediatric and adolescent athletes. CFL transfer over the peroneal tendons should be considered as it provides excellent stability, a low rate of recurrent subluxation, and good functional outcomes without risk of injury to the distal fibular physis which can occur with distal fibular osteotomy or groove deepening procedures. IV (Case series).

Modified Chrisman–Snook repair for the treatment of chronic ankle ligamentous instability in children and adolescents

Chronic ankle ligamentous instability is not uncommonly encountered in children and adolescents. A number of operative procedures have been developed and described in the literature, including variations on the original Chrisman-Snook (CS) repair. The purpose of this study is to describe a modification of the CS repair and report the outcomes of this surgery for the treatment of chronic ankle ligamentous instability in children and adolescents. A retrospective review was conducted of 100 consecutive surgeries in 66 children performed by a single surgeon who modified the CS repair using a split peroneus brevis tendon to reinforce the anterior talofibular and calcaneofibular ligaments in chronic ligamentously lax patients. All charts were reviewed for complications. Fifty-three cases had at least a 2-year follow-up and were evaluated for the following outcomes: return to activity, ligamentous laxity, pain, and subsequent sprains. Of the 100 surgeries performed, no patient required repeat ligamentous repair. There were no deep wound infections. There were 10 cases of minor wound healing problems and two cases of temporary nerve dysfunction, one of which resolved without surgical intervention and the other is resolving with no plans for surgical intervention. There were two cases of sural nerve branch entrapment which required subsequent surgery due to neuroma formation. Of the 53 cases with at least a 2-year follow-up, the following outcomes were obtained: all patients returned to full activities of their choice; all but one case maintained ≤45° of ankle inversion postoperatively; all patients were pain free or had only occasional discomfort; and 23% of the ankles experienced subsequent minor sprains, but all were minor and resolved without consequence. A modification of the CS repair where the split peroneus brevis tendon is used to create ankle stability has been routinely successful in 100 consecutive cases of chronic ligamentous instability in children and adolescents with very few complications.

Anatomical reconstruction of the lateral ligaments using Gracillis tendon in chronic ankle instability; a new technique

Many surgical technique have been described to assess the outcome of anatomical reconstruction of the lateral ligaments using Gracillis tendon. This technique aims to restore the stability of the ankle by reconstruction of the talofibular ligament (ATFL) and the calcaneofibular ligament (CFL) using the Gracillis tendon. From January 2004 to February 2008; inclusive, 16 patients; 11 male and 5 female, underwent an anatomic reconstruction of the lateral ankle ligament for chronic ankle instability. Their ages ranged from 18 to 29 giving a mean age of 25 years. Patients were then subjected to radiologic and clinical assessments for a period of at least 33.5 months. For pain scoring the Americans Orthopaedic Foot and Ankle Society (AOFAS) scores were used; whilst subjective symptom was evaluated using the Olerud and Molander ankle scoring system. All patients returned for the final evaluation and subjective excellent or good results were recorded on self-assessment, pain scores, AOFAS and Karissons scores. Additionally Olerud and Molander ankle scoring was also done. During the final follow-up, the mean post-operative AOFAS score was 96 (range 80-100), the Visual analog score was 6 (range 0-4), Karissons score was 94.7 (range 80-100) and last but not least Olerud and Molander score was 87.5 (range 70-100). It was noted that the ankle range of motion was not affected by lateral ankle reconstruction. The talar tilt was reduced from a mean of 12-4° (p<0.0001) and the anterior drawer was reduced from a mean of 11-4mm (p<0.001) by the ankle ligament reconstruction. Anatomical reconstruction of the lateral ligaments of chronic ankle instability using Gracillis tendon graft resulted in successful results, excellent ankle stability, significant reduction in pain and negligible loss of ankle and hind foot motion.

Lateral Ligament Repair and Reconstruction Restore Neither Contact Mechanics of the Ankle Joint nor Motion Patterns of the Hindfoot

Ankle sprains may damage both the lateral ligaments of the hindfoot and the osteochondral tissue of the ankle joint. When nonoperative treatment fails, operative approaches are indicated to restore both native motion patterns at the hindfoot and ankle joint contact mechanics. The goal of the present study was to determine the effect of lateral ligament injury, repair, and reconstruction on ankle joint contact mechanics and hindfoot motion patterns. Eight cadaveric specimens were tested with use of robotic technology to apply combined compressive (200-N) and inversion (4.5-Nm) loads to the hindfoot at 0° and 20° of plantar flexion. Contact mechanics at the ankle joint were simultaneously measured. A repeated-measures experiment was designed with use of the intact condition as control, with the other conditions including sectioned anterior talofibular and calcaneofibular ligaments, the Broström and Broström-Gould repairs, and graft reconstruction. Ligament sectioning decreased contact area and caused a medial and anterior shift in the center of pressure with inversion loads relative to those with the intact condition. There were no significant differences in inversion or coupled axial rotation with inversion between the Broström repair and the intact condition; however, medial translation of the center of pressure remained elevated after the Broström repair relative to the intact condition. The Gould modification of the Broström procedure provided additional support to the hindfoot relative to the Broström repair, reducing inversion and axial rotation with inversion beyond that of intact ligaments. There were no significant differences in center-of-pressure excursion patterns between the Broström-Gould repair and the intact ligament condition, but this repair increased contact area beyond that with the ligaments intact. Graft reconstruction more closely restored inversion motion than did the Broström-Gould repair at 20° of plantar flexion but limited coupled axial rotation. Graft reconstruction also increased contact areas beyond the lateral ligament-deficient conditions but altered center-of-pressure excursion patterns relative to the intact condition. No lateral ankle ligament reconstruction completely restored native contact mechanics of the ankle joint and hindfoot motion patterns.

Outcome of the functional treatment of first-time ankle inversion injury

BackgroundAvulsion fractures of the lateral malleoli in ankle inversion injuries are often undetected on routine radiographs. Undetected avulsion fractures have been managed as ankle sprain, which may affect the outcome of the treatment of the ankle sprain. The purposes of this study are to compare the outcomes of functional treatment between the first-time severe ligament injury and avulsion fracture of the lateral ankle, and to investigate how the anterior talofibular ligament (ATFL) view or the calcaneofibular ligament (CFL) view affects the diagnosis of the avulsion fracture and outcome of functional treatment of the ankle inversion injury. MethodsA total of 276 consecutive patients with a first-time severe ankle inversion injury were classified into a ligament injury group (group I) or an avulsion fracture group (group II) on the basis of physical examination and radiographs. The patients with a negative finding on routine radiographs and a positive finding on the ATFL or CFL view derived from group II (group IIA). Age, sex, and activity level were analyzed. Patients were treated by stirrup splint. ResultsA total of 202 (73.2%) patients were in group I and 74 (26.8%) were in group II. In all, 50 patients in group II showed negative standard radiographs and a positive ATFL or CFL view. Altogether, 240 patients were followed up for at least 1 year and assessed clinically and radiographically. Differences in age, sex, and activity level before injury between groups were not statistically significant. Clinical and radiographic results of group II were inferior to those of group I. The outcome of group IIA was comparable to that of group I. ConclusionsThe outcome of functional treatment of avulsion fracture was inferior to that of ligament injury. The ATFL and CFL views provide a more precise diagnosis but do not affect the outcome of the functional treatment.

Evaluation of Arthrometer for Ankle Instability: A Cadaveric Study

Stress tests are used to diagnose both acute and chronic lateral ankle instability. Commonly used stress tests require radiography and their reliability and sensitivity is still under debate. We developed a non radiographic ankle arthrometer to objectively assess mechanical ankle stability. This device was validated against stress radiographs in a cadaver investigation. Nine cadaver specimens were tested under: 0, 15, and 30 degrees ankle plantarflexion and 50 N, 100 N, 150 N, and 200 N anterior drawer load application. First, intact specimens were tested. Then the anterior talofibular ligament, calcaneofibular ligament and posterior talofibular ligament were sequentially cut. Anterior drawer displacement was analyzed simultaneously by a displacement transducer and by radiographic measurement. Stiffness was calculated as the linear increment of the load deformation curve. Results of a commercially available stress testing device served as a standard. Stable and unstable ankles were differentiated by ankle arthrometer displacement and stiffness analyses (p = 0.012 and 0.003) with the arthrometer adjusted to 0 degrees of plantarflexion and 50 N anterior drawer load application. Standardized stress testing device and ankle arthrometer stress radiographic measurements correlated significantly (p = 0.000 to 0.027). Transducer measured anterior drawer instability was highly sensitive (96.3%), while specificity was 44.4%. Setting a cut off value of 4.5 N/mm, the stiffness analyses discriminated stable and unstable ankles with a sensitivity of 91.7% while the specificity was 62.5%. The ankle arthrometer was able to measure anterior subluxation of the talus in relation to the tibia in a cadaver experiment. The procedure is non-radiographic and highly sensitive in differentiating unstable from stable ankles. Availablity of a nonradiographic device to measure ankle instability could improve diagnostic accuracy and facilitate decision making in patients with chronic ankle instability.

Ankle Stability in Simulated Lateral Ankle Ligament Injuries

We performed a laboratory-based study of the ankle-hindfoot complex in normal cadaveric ankles with simulated lateral ankle ligament injuries, utilizing an ankle stability testing device. The ankle stability testing device distinguished between intact, injury to anterior talofibular ligament (ATFL) and combined injury to ATFL and calcaneofibular ligament (CFL). Ankles were tested in an ankle stability testing device, with a specified inversion torque applied through the range of sagittal plane motion, then internal rotation torque applied through the entire range of sagittal plane motion. Three-dimensional motion of the calcaneus and talus in relation to the tibia were determined with a magnetic tracking system. The specimens were tested in the intact condition, then after sectioning the ATFL, then the CFL. Upon sectioning the ATFL, there was a significant increase in the internal rotation motion at the tibiotalar joint. Subsequent sectioning of the CFL did not significantly increase ankle-hindfoot internal rotation, but it did significantly increase the motion in inversion testing. This increase occurred primarily at the tibiotalar level. The isolated ATFL injury was clearly distinguished from the intact condition by increased talar-tibial internal rotation, but not inversion. The more severe combined ATFL/CFL injury was distinguished from the ATFL injury condition with inversion torque. Inversion torque may disclose combined ATFL/CFL injury, and internal rotation torque may be the key to distinguish isolated ATFL and combined ATFL/CFL injuries.

Combination of Modified Broström Procedure With Ankle Arthroscopy for Chronic Ankle Instability Accompanied by Intra-articular Symptoms

To evaluate the effectiveness of the modified Broström procedure combined with ankle arthroscopy for chronic ankle instability (CAI) accompanied by intra-articular symptoms. We identified 85 consecutive patients with CAI (87 ankles). There were 58 male patients (58 ankles) and 27 female patients (29 ankles) with a mean age of 24.4 years (range, 14 to 36 years). All the patients had intra-articular symptoms. Ankle arthroscopic surgery was performed initially to manage any intra-articular lesions. This was followed by the modified Broström procedure, including shortening of the anterior talofibular ligament and/or calcaneofibular ligament, as well as extensor retinaculum augmentation. All the intra-articular lesions found during surgery were recorded. American Orthopaedic Foot & Ankle Society (AOFAS) scores were obtained before surgery and at follow-up. Intra-articular lesions were found in 79 ankles (90.8%), including 75 with synovitis and soft-tissue impingement, 33 with chondral injuries, 23 with anterior tibial osteophytes, 7 with loose bodies, and 6 with distal tibiofibular syndesmosis injuries. A total of 79 patients (92.9%) (81 ankles) were followed up for a mean of 29 months (range, 12 to 47 months). The mean AOFAS score improved from 46.6 +/- 8.1 preoperatively to 86.5 +/- 7.6 postoperatively (P < .05). Mean postoperative AOFAS scores were significantly higher in patients without chondral lesions than in those with chondral lesions (89.76 +/- 5.88 and 81.35 +/- 7.18, respectively; P < .05). Improvements in AOFAS scores after surgery were significantly greater in patients without chondral lesions than in those with chondral lesions (42.28 +/- 9.04 and 36.06 +/- 11.85, respectively; P < .05). The modified Broström procedure combined with ankle arthroscopy produced satisfactory surgical outcomes in patients with CAI and intra-articular symptoms. Accompanying chondral injuries were associated with poorer surgical outcomes. Level IV, therapeutic case series.

Visibility of the lateral collateral ligaments in routine computed tomography of the ankle

Sir, I have read with great interest the article of Hua et al. [2] in a recent issue. They reported the detailed cross-sectional anatomy of the lateral collateral ligaments of the ankle on computed tomography (CT) and magnet resonance imaging (MRI). They used anatomic specimen and coated the ligaments with contrast media for CT imaging. Whether the ligaments could also be seen on CT scans in vivo was not addressed, but this could be a clinical relevant issue. Here routine CT scans of the ankle were reviewed. The sample consisted of eight patients; all patients were examined for purposes other than acute trauma to the ankle (imaging of orthopaedic hardware, arthrodesis, osteomyelitis, suspected complex regional pain syndrome) and had no clinical suspicion of ankle sprain. All patients were examined using the same 16-slice scanner with identical parameters (slice thickness 0.5 mm, 50 mA s, 120 kV) and were reviewed on a standard workstation. The anterior talofibular ligament could be clearly depicted in all patients as a hyperdense ligament (Fig. 1). The posterior talofibular ligament could be depicted in five of the eight patients and the calcaneofibular ligament could be depicted completely in three of the eight patients and in part in another two patients. Fig. 1 Axial slices of a computed tomography of the ankle in a soft tissue window (left) and a bone window setting (right). The anterior talofibular ligament could be easily depicted as a slight hyperdense ligament, especially in the soft tissue window setting ... Imaging of the lateral collateral ligaments is possible using arthrography, sonography and MRI, with MRI being the imaging method of choice in complicated or equivocal cases. CT has mostly been used to search for subtle fractures in complicated ankle sprains, but there are also a few reports about imaging of the ligaments [1, 3, 5]. In this small series the anterior talofibular ligament could be seen in all patients and the other ligaments in a large portion of patients. An intact anterior talofibular ligament could help to rule out a rupture of the lateral collateral ligaments, because it is the first to be torn in ankle sprains. This approach has been recently shown to be reliable for the imaging of the cruciate ligaments of the knee in CT imaging [4]. So clearly a large study to compare MRI and CT is warranted to establish the exact role of CT imaging of the lateral collateral ligaments and to make sure we use the full potential of the widespread available and often performed CT scans of the ankle.

Ultrasound of the ankle.

Ultrasound of the ankle.

An Anatomic and Autologous Lateral Ankle Stabilization

A new technique for stabilization of the lateral ankle ligaments is presented. The procedure uses a split peroneus longus tendon to recreate the calcaneofibular and anterior talofibular ligaments. The new ligaments follow a precise anatomic course that replicates the pathway of the original ligaments. The procedure also capitalizes on interference screw technology so that accurate ligament tension can be obtained. This technique is most useful for severe ligamentous insufficiency involving both the calcaneofibular and anterior talofibular ligaments. Biomechanical rationale for the use of peroneus longus is also discussed.

Mechanical Stability of the Subtalar Joint After Lateral Ligament Sectioning and Ankle Brace Application

Background The roles of each ligament supporting the subtalar joint have not been clarified despite several biomechanical studies. The effects of ankle braces on subtalar instability have not been shown. Hypothesis The ankle brace has a partial effect on restricting excessive motion of the subtalar joint. Study Design Controlled laboratory study. Methods Ten normal fresh-frozen cadaveric specimens were used. The angular motions of the talus were measured via a magnetic tracking system. The specimens were tested while inversion and eversion forces, as well as internal and external rotation torques, were applied. The calcaneofibular ligament, cervical ligament, and interosseous talocalcaneal ligament were sectioned sequentially, and the roles of each ligament, as well as the stabilizing effects of the ankle brace, were examined. Results Complete sectioning of the ligaments increased the angle between the talus and calcaneus in the frontal plane to 51.7° ± 11.8° compared with 35.7° ± 6.0° in the intact state when inversion force was applied. There was a statistically significant difference in the angles between complete sectioning of the ligaments and after application of the brace (34.1° ± 7.3°) when inversion force was applied. On the other hand, significant differences in subtalar rotation were not found between complete sectioning of the ligaments and application of the brace when internal and external rotational torques were applied. Conclusion The ankle brace limited inversion of the subtalar joint, but it did not restrict motion after application of internal or external rotational torques. Clinical Relevance In cases of severe ankle sprains involving the calcaneofibular ligament, cervical ligament, and interosseous talocalcaneal ligament injuries, application of an ankle brace might be less effective in limiting internal-external rotational instabilities than in cases of inversion instabilities in the subtalar joint. An improvement in the design of the brace is needed to restore better rotational stability in the subtalar joint.

Modified Incision for Brostrom Lateral Ligament Reconstruction of the Ankle

To describe a modified incision for the Brostrom procedure to correct lateral ankle instability. 14 men and 12 women aged 23 to 38 (mean, 27) years with lateral ankle instability underwent the Brostrom procedure with a modified incision to repair both the anterior talofibular and calcaneofibular ligaments, without endangering the sural or superficial peroneal nerves. The incision ran longitudinally over the distal fibula extending 2.5 cm distal to the tip of the lateral malleolus. There were no instances of wound healing problems, neurological damage, and repair failure. Surgical exposure of all patients was graded as excellent. The modified incision enables easy repair without endangering the sural and superficial peroneal nerves. Access to the peroneal tendons is allowed if necessary.

Accuracy of MRI scan in the diagnosis of ligamentous and chondral pathology in the ankle

The aim of our study is to determine the accuracy of magnetic resonance imaging (MRI) scan in relation to arthroscopic findings in patients presenting with chronic ankle pain and/or instability. All patients who underwent arthroscopy of the ankle as well as MRI from December 2005 to July 2008 in our institution were reviewed by the Orthopaedic surgeons. Twenty-four patients were identified and the results of MRI scans were compared with arthroscopic findings. This study specifically looked at anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL) and osteochondral lesions (OCD). Arthroscopic findings were considered as a gold standard. There were 12 female and 12 male patients with an average age 39 years (11-65 years). Time interval between MRI scan and arthroscopy was 7.0 months (2-18 months). In our study MRI showed 100% specificity for the diagnosis of ATFL and CFL tears and osteochondral lesions. However sensitivity was low particularly for CFL tears. Accuracy of MRI in detecting ATFL tear was 91.7%, CFL tear was 87.5% and osteochondral lesion was 83.3%. We conclude that MRI scan has very high specificity and positive predictive value in diagnosing tears of ATFL, CFL and osteochondral lesions. However sensitivity was low with MRI. In a symptomatic patient negative results on MRI must be viewed with caution and an arthroscopy may still be required for a definitive diagnosis and treatment. However high resolution scans may differ in their ability to pick up these lesions and further research is required to assess their efficiency as evidence is not currently available.

Sustantial Observation on Foot Taeyang Meridian Muscle in Human Lower Limb from a Anatomical Viewpoint

Objective : This study was carried to identify the anatomical component of FTMM(Foot Taeyang Meridian Muscle) in human lower limb, and further to help the accurate application to real acupunc- ture. Methods : FTM at the surface of the lower limb was labelled with latex. And cadaver was stripped off to demonstrate muscles, nerves and the others and to display the internal structures of FTMM, being divided into outer, middle, and inner layer. Results : FTMM in human lower limb is composed of muscles, nerves, ligaments etc. The internal composition of the FTMM in human lower limb are as follows : 1) Muscle : Gluteus maximus. biceps femoris, semitendinosus, gastrocnemius, triceps calf, fibularis brevis tendon, superior peroneal retinacula, calcaneofibular ligament, inferior extensor retinaculum, abductor digiti minimi, sheath of flexor tendon at outer layer, biceps femoris, semimembranosus, plantaris, soleus, posterior tibialis, fibularis brevis, extensor digitorum brevis, flexor digiti minimi at middle layer, and for the last time semimembranosus, adductor magnus, plantaris, popliteus, posterior tibialis, flexor hallucis longus, dorsal calcaneocuboidal ligament at inner layer. 2) Nerve : Inferior cluneal nerve, posterior femoral cutaneous n., sural cutaneous n., proper plantar branch of lateral plantar n. at outer layer, sciatic nerve, common peroneal n., medial sural cutaneous n., tibial n. at middle layer, and for the last time tibial nerve, flexor hallucis longus branch of tibial n. at inner layer. Conclusions : This study proves comparative differences from already established studies from the viewpoint of constituent elements of FTMM in the lower limb, and also in the aspect of substantial assay method. We can guess that there are conceptional differences between terms (that is, nerves which control muscles of FTMM and those which pass near by FTMM) in human anatomy.

A new one-DOF fully parallel mechanism for modelling passive motion at the human tibiotalar joint

Knowledge on how ligaments and articular surfaces guide passive motion at the human ankle joint complex is fundamental for the design of relevant surgical treatments. The paper presents a possible improvement of this knowledge by a new kinematic model of the tibiotalar articulation. Passive motion, i.e. in virtually unloaded conditions, was captured in vitro in four lower leg specimens by means of a surgical navigation system with cluster of active markers attached to the tibia and talus. The anatomical geometry of the passive structures, i.e. articular surfaces and attachment areas of the ligaments, were taken by digitisation with a pointer. An equivalent spatial mechanism for the passive motion simulation was defined by three sphere-to-sphere contact points and two rigid links. These contact points were identified at the lateral talo-fibular articulation and at the medial and lateral aspects of the articulation between tibial mortise and trochlea tali. The two rigid links were identified by the isometric fibres at the calcaneofibular and tibiocalcaneal ligaments. An optimisation algorithm was developed for the identification of the final geometrical parameters resulting from an iterative refining process, which targets best matching between model predictions and corresponding experimental measurements of the spatial motion. The specimen-specific equivalent spatial mechanisms replicated the original passive motion very well, with mean discrepancies in position smaller than 2.5mm and in rotation smaller than 1°. The study demonstrates that the articular surfaces and the ligaments, acting together as a mechanism, control the passive kinematics of the ankle joint.

Ankle Instability

Acute ankle sprains are common, and if inadequately treated may result in chronic instability. Lateral ankle injuries are most common, with deltoid injuries rare and associated with ankle fractures/dislocation. Medial ankle instability is rare. Functional management of acute lateral ankle sprains is the treatment of choice, with acute ligament repair reserved for athletes. Chronic lateral ankle instability is initially managed conservatively, however, failure of rehabilitation is an indication for surgical management. Nonanatomic tenodesis reconstructions have poor long-term results, sacrifice peroneal tendons, and disrupt normal ankle and hindfoot biomechanics. Anatomic repair of the anterior talofibular and calcaneofibular ligaments is recommended when the quality of the ruptured ligaments permits. Anatomic reconstruction with autograft or allograft should be performed when ligaments are attenuated. The role of arthroscopic reconstruction is evolving. Ankle arthroscopy should be performed at the time of repair or reconstruction and should address any other intra-articular causes of pain.

Arthroscopic release to treat subtalar stiffness after calcaneal fracture

To report the results of arthroscopic release to treat subtalar stiffness after calcaneal fractures. From September 2004 to December 2006, 10 cases of subtalar stiffness were treated. There were 8 male and 2 female cases, with an average age of 36 years old (ranging from 18 to 48). All, but 2 cases, had single subtalar involvement. The routine triple portals (lateral, anterolateral, posterolateral portals) were applied with the patient placed in the lateral decubitus position. The anterior capsule, lateral gap, calcaneofibular ligament, posterior capsule together with the posteromedial corner of the subtalar joint were released step by step under arthroscopic control. Finally, manual release was performed. All cases were followed-up for 12 to 36 months (mean, 24.5 months). According to the AOFAS hindfoot activity rating scale, 10 cases were rated as Grade III, 2 as Grade II before the surgery. Nine cases were improved to Grade I, 3 to Grade II at the last follow-up after the surgery. AOFAS hindfoot scores were significantly improved from 71.4 before the surgery to 90.6 at the last follow-up (P < 0.01). All cases returned to the previous work at an average of 1.8 months (range, 1 to 3 months) after the surgery. Arthroscopic release to treat subtalar stiffness after calcaneal fracture has such advantages as minimally-invasiveness, simplicity and effectiveness.

Alterations in oestrogen metabolism: implications for higher penetrance of familial pulmonary arterial hypertension in females

Mutations in bone morphogenetic protein receptor type 2 (BMPR2) cause familial pulmonary arterial hypertension (FPAH), but the penetrance is reduced and females are significantly overrepresented. In addition, gene expression data implicating the oestrogen-metabolising enzyme CYP1B1 suggests a detrimental role of oestrogens or oestrogen metabolites. We examined genetic and metabolic markers of altered oestrogen metabolism in subjects with a BMPR2 mutation. Genotypes for CYP1B1 Asn453Ser (N453S) were determined for 140 BMPR2 mutation carriers (86 females and 54 males). Nested from those subjects, a case-control study of urinary oestrogen metabolite levels (2-hydroxyoestrogen (2-OHE) and 16alpha-hydroxyoestrone (16alpha-OHE(1))) was conducted in females (five affected mutation carriers versus six unaffected mutation carriers). Among females, there was four-fold higher penetrance among subjects homozygous for the wild-type genotype (N/N) than those with N/S or S/S genotypes (p = 0.005). Consistent with this finding, the 2-OHE/16alpha-OHE(1) ratio was 2.3-fold lower in affected mutation carriers compared to unaffected mutation carriers (p = 0.006). Our findings suggest that variations in oestrogens and oestrogen metabolism modify FPAH risk. Further investigation of the role of oestrogens in this disease with profound sex bias may yield new insights and, perhaps, therapeutic interventions.

Function of anterior talofibular and calcaneofibular ligaments during in-vivo motion of the ankle joint complex

BackgroundDespite the numerous in-vitro studies on the mechanical properties and simulated injury mechanisms of the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL), the in-vivo biomechanical behavior of these two ligaments has not yet been described.MethodsApparent length of the ATFL and CFL was measured in four ankles in healthy male subjects between 32 and 45 years of age (two left and two right) during a dorsiflexion-plantarflexion and supination-pronation arc of motion using a combined dual-orthogonal fluoroscopic and magnetic resonance imaging technique.ResultsThe ATFL elongated from the neutral position at 16.3 +/- 3.0 mm to 20.8 +/- 2.7 mm at maximal plantarflexion and shortened significantly from the neutral position to 13.9 +/- 2.9 mm at maximal dorsiflexion (p = 0.01). The CFL shortened from the neutral position at 28.0 +/- 2.9 mm to 26.6 +/- 2.2 mm at maximal plantarflexion (p = 0.08) and elongated significantly from the neutral position to 29.9 +/- 3.0 mm at maximal dorsiflexion (p = 0.003). The ATFL elongated significantly from 14.8 +/- 2.5 mm at maximal pronation to 17.4 +/- 3.0 mm at maximal supination (p = 0.08). At the same time, the CFL shortened from 31.0 +/- 3.8 mm at maximal pronation to 26.9 +/- 3.6 mm at maximal supination (p = 0.02).ConclusionThe results showed that the ATFL elongates more during plantarflexion and supination whereas the CFL increases in length with dorsiflexion and pronation. Concurrently, these data also demonstrated the reciprocal function between the two ligaments. While one shortens, the other one elongates. The different elongation of the ATFL and CFL during the same motion arc suggests that under excessive loading conditions the ATFL might be more vulnerable in plantarflexion and supination while the CFL might be more susceptible to injury in dorsiflexion and pronation. Furthermore, in the case of surgical reconstruction the grafts used to reconstruct the two ligaments may need to be tensioned at different positions of the ankle in order to reproduce their natural in vivo function.