Subtalar Joint Complex Research Articles

Passive motion characteristics of the talocrural and the subtalar joint by dual Euler angles

The objective of this study is to validate previous descriptions of hindfoot kinematics using dual Euler angle methods in a passive cadaveric model. The dual Euler angle method was chosen so as to facilitate description of the translational and rotational movement occurring at both the ankle and subtalar joints. A non-metal experimental set-up was fabricated to generate motion in foot cadaver specimens. Three-dimensional kinematic data of the ankle joint complex was collected from ten knee-below foot cadaver specimens using a ‘Flock of Birds’ electromagnetic tracking device. The data correlates well with previously published kinematic descriptions of the ankle subtalar joint complex. Both the ankle and subtalar joint show 6 degree of freedom motion and multiaxial characteristics. The motions of the talocrural joint, the talocalcaneal joint, and the gross motion between the foot and the shank were analyzed. During dorsiflexion–plantarflexion the motion of the calcaneus with respect to the tibia occurs mainly at the ankle joint, with little motion at the subtalar joint. The subtalar joint contributes more than the ankle joint during inversion–eversion.

Mobility of the subtalar joint in the intact ankle complex

A previous study by these authors showed that the calcaneus follows a unique path of unresisted coupled motion relative to the tibia during passive flexion and that most of this motion occurred at the ankle level. Subtalar motion in the intact ankle complex was observed only when perturbations from this path were induced by the application of force to the calcaneus. Relative motion of the bones of the ankle complex was tracked by stereophotogrammetry in seven specimens. Anatomical landmarks, reference frames and joint angles were defined by standard techniques. Sequential moments were applied to the calcaneus about the long axis of the tibia. Measured movements at subtalar level demonstrated plantarflexion coupled to supination and internal rotation (inversion) and dorsiflexion coupled to pronation and external rotation (eversion). These movements were resisted and were fully recovered when the external load was removed. Subtalar motion diminished as the ankle approached maximal dorsi- and plantarflexion. Two clearly distinguished mean axes of rotation were observed for inversion and eversion runs. The axes of inversion and eversion of the subtalar complex changed orientation along a preferred and repeatable path. The subtalar joint complex occupied only a single stable position in the unloaded state and with no range of unresisted motion. It is inferred that mobility was possible only by the stretching and lengthening of the ligaments and the indentation of the articular surfaces, requiring the application of loads. The subtalar joint complex behaves like a flexible structure.

Relationship of ankle joint involvement with subtalar destruction in patients with rheumatoid arthritis.A 20-year follow-up study

Aims. In the present study we evaluated radiographically involvement of the ankle joint and its relationship to destruction of the subtalar joint in rheumatoid arthritis (RA). Methods. An inception cohort of 103 patients with seropositive RA was followed over a period of 20 years. Follow-up examinations were conducted after onset, 1, 3, 8, 15, and 20 years from entry. A total of 83 patients attended the 15-year and 68 patients the 20-year follow-up. Radiographic evaluation was performed using a lateral weight-bearing ankle radiograph. A simplified grading was applied for the talocrural joint, in which the ankles (patients) were divided into three groups: no changes, minor changes and major changes. In the end-point analysis the last radiograph was assigned. Subtalar destruction was recorded (Larsen grade ≥ 2). Severity of RA in different groups was evaluated using the Larsen score of 0–100 of hands and feet. Difference between patient groups was evaluated using Cuzick’s test. Results. At the endpoint major changes of the ankles were detected in seven patients (7%) only, minor changes were observed in 17 patients (16%). The first minor involvement of the ankle was observed at the three-year follow-up in two patients. First major changes were detected at the 15-year follow-up in three ankles of two patients. Subtalar pathology preceded that of TC joint in all ankles with major changes. In 17 patients with minor changes, simultaneous subtalar pathology was observed in all but two ankles, while preceding subtalar involvement was radiographically manifest in 13 of 21 ankles. The means of Larsen scores of 0–100 were in the three ankle grading groups 40, 54 and 63, respectively. Cuzick’s test for the trend was highly significant ( P < 0.001). No reconstructive surgery was performed on the ankle joint during the follow-up, whereas the subtalar joint complex was fused cumulatively in 12 patients. Conclusions. The ankle joint is involved in a late stage of RA and is usually affected only in the patients with severe disease. Subtalar pathology precedes the changes in the talocrural joint almost regularly.

Relation entre arthrite de cheville et destruction sous-astragalienne au cours de la polyarthrite rhumatoïde. Une étude prospective de 20 ans

Objectives. In the present study we evaluated radiographically involvement of the ankle joint and its relationship with destruction of subtalar joint in rheumatoid arthritis (RA). Patients and methods. An inception cohort of 103 patients with seropositive RA was followed over a period of 20 years. Follow-up examinations were conducted after onset 1, 3, 8, 15, and 20 years from entry. A total of 83 patients attended the 15-year and 68 patients the 20-year follow-up. Radiographic evaluation was performed using a lateral weight-bearing ankle radiograph. A simplified grading was applied for the talocrural joint, in which the ankles (patients) were divided into 3 groups: no changes, minor changes and major changes. In the end point analysis the last radiograph was assigned. Subtalar destruction was recorded (Larsen grade ≥ 2). Severity of RA in different groups was evaluated using the Larsen score of 0 – 100 of hands and feet. Difference between patient groups was evaluated using Cuzicks test. Results. At the end point major changes of the ankles were detected in 7 patients (7%) only, minor changes were observed in 17 patients (16%). The first minor involvement of the ankle was observed at the 3-year follow-up in 2 patients. Fist major changes were detected at the 15-year follow-up in 3 ankles of 2 patients. Subtalar pathology preceded that of TC-joint in all ankles with major changes. In 17 patients with minor changes, simultaneous subtalar pathology was observed in all but 2 ankles, while preceding subtalar involvement was radiographically manifest in 13 of 21 ankles. The means of Larsen scores of 0–100 were in the three ankle grading groups 40, 54 and 63, respectively. Cuzicks test for the trend was highly significant (p < 0.001). No reconstructive surgery was performed on the ankle joint during the follow-up, whereas the subtalar joint complex was fused cumulatively in 12 patients. Conclusion. Ankle joint is involved in a late stage of RA and it usually is affected only in the patients with severe disease. Subtalar pathology precedes the changes in talocrural joint almost regularly.

Surgical treatment of congenital vertical talus using the cincinnati approach

Objectives Complete correction of a congenital vertical talus at the subtalar joint complex in 1 sitting. The goal is a restoration of normal shape and function of the foot.

The development of a three plane system for the measurement of the ankle/subtalar joint complex in gait

Current instrumentation renders foot analysis in gait expensive, complicated and unreliable. The Polhemus Isotrak Magnetic Tracking System offers an accurate, low cost alternative to other systems which measure the ankle and subtalar joint complex. By fixing the transmitter above the tibia and aligning it to the cardinal body planes the reference frame moves with the proximal segment. The receiver is attached to the calcaneum permitting instant measurement of calcaneal movement relative to the tibia in standard clinical planes. The system has been tested on a non-metallic model and on 29 subjects giving accurate (within 2° for frontal and sagittal planes) and repeatable readings through large ranges (up to 180°). Dynamic data from 22 healthy subjects were collected on a 9 m walkway. Readings vary with sensor position and the calcaneum moves through a significantly different range (mean ±2.1°) to the shoes so that the sensor should be attached to the calcaneum rather than the heel counter of the shoe.

Simulated lateral ankle ligamentous injury. Change in ankle stability.

The effect of simulated ankle ligamentous injury on ankle-subtalar joint complex laxity was studied. Thirty-six intact ankles were loaded in inversion-eversion and anterior-posterior directions. Motions of the talus and calcaneus were measured with respect to the tibia. Ankles were tested at neutral, 15 degrees of dorsiflexion, and 15 degrees of plantar flexion. In all the specimens the anterior talofibular ligament was sectioned and then the calcaneofibular ligament was sectioned; testing was then repeated. With sectioning of the anterior talofibular ligament, motion increased primarily in dorsiflexion with both anterior-posterior and inversion-eversion loading. This increase was primarily caused by a large increase in subtalar motion. Additional sectioning of the calcaneofibular ligament produced little change in ankle subtalar joint motion except in dorsiflexion. Clinically, these findings show that if an anterior-posterior drawer test shows less laxity in dorsiflexion than in neutral and greater laxity than the contralateral asymptomatic side, then an isolated anterior talofibular ligamentous tear exists. Similarly, laxity in 15 degrees of dorsiflexion and in neutral suggests calcaneofibular ligament disruption. During inversion-eversion loading, the increase in ankle-subtalar joint complex rotation with calcaneofibular ligament sectioning occurred primarily in the ankle joint, implying that the calcaneofibular ligament constrains the talus through the calcaneus. Therefore, a talar tilt on stress radiographs demonstrates a torn calcaneofibular ligament.

Correction of clubfoot through a peritalar release using the cincinnati approach

Surgical Principles The Cincinnati approach described by Crawford et al. [1] allows a complete medial, posterior and lateral exposure of hind- and midfoot as well as a correction of any deformity of the subtalar, talonavicular, and calcaneocuboid joints (subtalar joint complex): Correction of the rotational malposition between talus and os calcis with simultaneous reduction of the talonavicular and calcaneocuboid joints. After wound closure the corrected position is maintained by a long leg cast. In severe clubfeet an additional fixation with Kirschner wires of the talonavicular and the subtalar joints may be indicated.

Biomechanics of the Subtalar Joint Complex

The subtalar joint complex is formed by the posterior talocalcaneal joint and the acetabulum pedis lodging the talar head. The basic motion at the joint is that of male ovoid surfaces moving over female ovoid surfaces and vice versa. The motion generated at the joint is that of flexion-supination-adduction or extension-pronation-abduction. The subtalar motion is generated by the contour and orientation of the articular surfaces and is guided by the intrinsic ligaments: the interosseous talocalcaneal ligament of the canalis tarsi and the cervical ligament. Further support is provided by the extrinsic ligaments: the calcaneofibular ligament and the tibiocalcaneal fascicle of the deltoid ligament. Under tibiotalar vertical loading with internal rotation, the subtalar joint complex is in a close-pack position with maximum talar head surface contact in the acetabulum pedis. The component ligaments of the latter are under maximum tension. The posterior talocalcaneal surfaces are interlocked laterally.

Subtalar arthrosis following ankle arthrodesis

27 patients treated by ankle arthrodesis (bilateral in 1 case) have been followed up for median 5.8 years (range 1–11). The patients were evaluated according to an ankle score system except for range of motion. Radiographic examination revealed 4 28 subtalar arthroses preoperatively and 15 28 at follow-up. Apart from that, the material was complicated by 6 28 deep infections and 4 28 non-unions. 2 28 had below-knee amputations. 13 28 had pain in the operated area. Of the 11 cases developing subtalar arthrosis during the period of follow-up, 6 were found to be caused by either compression across the subtalar joints or compression pins passing through the joints. This was significantly different from the results in patients treated without this complication ( P < 0.001). On the basis of the results, it was concluded that ankle arthrodesis carries a high percentage of complications, not at least in the subtalar joints. This last complication may be reduced by surgical avoidance of the subtalar joint complex.

Partial immobilization of the ankle and talar joints complex and its effect on the ground--foot force characteristics.

A combined qualitative–quantitative approach towards the analysis of the ground reaction forces is suggested so as to detect deficiencies and predict hazards in human locomotion. The population studied is a group of patients who have undergone partial or full arthrodesis of the ankle–subtalar joint complex. The various ways in which the effects of ankle fusion are reflected on the force characteristics are discussed. The non-uniformity of reflection suggests an elaborate compensatory mechanism which is also being considered. As a conclusion it is suggested that surgical corrections such as immobilization of joints may be hazardous to the skeletal elements unless adequate compensatory walking habits are developed. The reduced flexibility of the system has to be compensated either by involving other joints, such as the knee, in the force attenuation process or by provision of flexible footware.