Anatomic Arthroscopic Graft Reconstruction of the Interosseous Talocalcaneal Ligament for Subtalar Instability

Talocalcaneal Ligament Reconstruction Kinematic Simulation for Progressive Collapsing Foot Deformity

BACKGROUND

In progressive collapsing foot deformity (PCFD), an internal and plantar rotation of the talus relative to the calcaneus may result in painful peritalar subluxation. Medial soft tissue procedures (eg, spring ligament repair) aim to correct the talar position via the navicular bone if bony correction alone is not sufficient. The effect of the medial soft tissue reconstruction on the talar reposition remains unclear. We hypothesized that a subtalar talocalcaneal ligament reconstruction might be favorable in PCFD to correct talar internal malposition directly. This pilot study aims to evaluate the anatomical feasibility and kinematic behavior of a subtalar ligament reconstruction in PCFD.

METHODS

Three-dimensional surface model from 10 healthy ankles were produced. A total of 1089 different potential ligament courses were evaluated in a standardized manner. A motion of inversion/eversion and talar internal/external in relation to the calcaneus were simulated and the ligament strain, expressed as a positive length variation, for each ligament was analyzed. The optimal combination for the ligament reconstruction with increased length in internal rotation of the talus, isometric kinematic behavior in inversion/eversion, and extraarticular insertion on talus and calcaneus was selected.

RESULTS

A laterodistal orientation of the talar insertion point in respect to the subtalar joint axis and laterodistal deviation of the calcaneal insertion point presents the highest ligament lengthening in internal talar rotation (+0.56 mm [3.8% of total length]) and presented a near-isometric performance in inversion/eversion (+0.01 to -0.01 mm [0.1% of total length]).

CONCLUSION

This kinematic model shows that a ligament reconstruction in the subtalar space presents a pattern of length variation that may stabilize the internal talar rotation without impeding the physiological subtalar motion.

CLINICAL RELEVANCE

This study investigates the optimal location, feasibility, and kinematic behavior of a ligament reconstruction that could help stabilize peritalar subluxation in progressive collapsing foot deformity.

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Reconstruction of the interosseous talocalcaneal ligament using allograft for subtalar joint stabilization is effective

PURPOSE

The aim of this study was to assess the biomechanical effects of subtalar ligament injury and reconstruction on stability of the subtalar joint in all three spatial planes.

METHODS

Fifteen fresh frozen cadaveric legs were used, with transfixed tibiotalar joints to isolate motion to the subtalar joint. An arthrometer fixed to the lateral aspect of the calcaneus measured angular displacement in all three spatial planes on the inversion and eversion stress tests. Stress manoeuvres were tested with the intact joint, and then repeated after sequentially sectioning the inferior extensor retinaculum (IER), cervical ligament (CL), interosseous talocalcaneal ligament (ITCL), arthroscopic graft reconstruction of the ITCL, and sectioning of the calcaneo-fibular ligament (CFL).

RESULTS

Sectioning the ITCL significantly increased angular displacement upon inversion and eversion in the coronal and sagittal planes. Reconstruction of the ITCL significantly improved angular stability against eversion in the axial and sagittal planes, and against inversion in the axial and coronal planes, at the zero time point after reconstruction. After sectioning the CFL, resistance to eversion decreased significantly in all three planes.

CONCLUSION

Progressive injury of ligamentous stabilisers, particularly the ITCL, led to increasing angular displacement of the subtalar joint measured with the inversion and eversion stress tests, used in clinical practice. Reconstruction of the ITCL using tendon graft significantly stabilised the subtalar joint in the axial and sagittal planes against eversion and in the axial and coronal planes against inversion, immediately after surgery.

Acute and Chronic Subtalar Joint Instability: Does It Really Exist?

Acute and chronic subtalar instability and commonly coexistent with other hindfoot pathology but can be difficult to diagnose. A high degree of clinical suspicion is required as most imaging modalities and clinical maneuvers are poor at detecting isolated subtalar instability. The initial treatment is similar to ankle instability, and a wide variety of operative interventions have been presented in the literature for persistent instability. Outcomes are variable and limited.

Role of the intrinsic subtalar ligaments in subtalar instability and consequences for clinical practice

Subtalar instability (STI) is a disabling complication after an acute lateral ankle sprain and remains a challenging problem. The pathophysiology is difficult to understand. Especially the relative contribution of the intrinsic subtalar ligaments in the stability of the subtalar joint is still controversial. Diagnosis is difficult because of the overlapping clinical signs with talocrural instability and the absence of a reliable diagnostic reference test. This often results in misdiagnosis and inappropriate treatment. Recent research offers new insights in the pathophysiology of subtalar instability and the importance of the intrinsic subtalar ligaments. Recent publications clarify the local anatomical and biomechanical characteristics of the subtalar ligaments. The cervical ligament and interosseous talocalcaneal ligament seem to play an important function in the normal kinematics and stability of the subtalar joint. In addition to the calcaneofibular ligament (CFL), these ligaments seem to have an important role in the pathomechanics of subtalar instability (STI). These new insights have an impact on the approach to STI in clinical practice. Diagnosis of STI can be performed be performed by a step-by-step approach to raise the suspicion to STI. This approach consists of clinical signs, abnormalities of the subtalar ligaments on MRI and intraoperative evaluation. Surgical treatment should address all the aspects of the instability and focus on a restoration of the normal anatomical and biomechanical properties. Besides a low threshold to reconstruct the CFL, a reconstruction of the subtalar ligaments should be considered in complex cases of instability. The purpose of this review is to provide a comprehensive update of the current literature focused on the contribution of the different ligaments in the stability of the subtalar joint. This review aims to introduce the more recent findings in the earlier hypotheses on normal kinesiology, pathophysiology and relation with talocrural instability. The consequences of this improved understanding of pathophysiology on patient identification, treatment and future research are described.

A high rate of talocalcaneal interosseous ligament tears was found in chronic lateral ankle instability with sinus tarsi pain

PURPOSE

To evaluate the arthroscopic findings of subtalar joints, including interosseous talocalcaneal ligament (ITCL) tear, in patients with chronic lateral ankle instability (CLAI) and sinus tarsi pain.

METHODS

A total of 118 ankles (109 patients) having CLAI with sinus tarsi pain who had undergone subtalar arthroscopy and lateral ankle ligament surgery were evaluated. The medical records, radiologic images, and the arthroscopic images and videos were reviewed. ITCL tears were classified into 4 grades: grade 0 (no tear), grade 1 (mild), grade 2 (moderate), and grade 3 (severe). The efficacy of magnetic resonance imaging (MRI) in diagnosing ITCL tears was also evaluated by comparing preoperative official readings of MRI to arthroscopic findings. The pre- and postoperative functional scores were also assessed.

RESULTS

The overall tear rate of ITCL was 107/118 (90.7%). There were 29 ankles (23.6%) with grade 1, 42 ankles (35.6%) with grade 2, and 36 ankles (30.5%) with grade 3 tears. Isolated lateral ankle instability (LAI) was diagnosed in 43 ankles (36.4%), subtalar instability (STI) in 30 ankles (25.4%), and LAI with STI in 45 ankles (38.1%). There was a statistically significant relationship between the ITCL tear grade and the final diagnosis. ITCL tear was confirmed or suspected in 81 ankles (68.6%) on preoperative MRI. Pain Visual Analog Score and functional outcome scores including the American Orthopaedic Foot & Ankle Society and Karlsson-Peterson scores showed significant improvement after the surgery.

CONCLUSION

A high rate (90.7%) of ITCL tears was noted in CLAI patients with sinus tarsi pain. ITCL damage may play an important role in subtalar instability in patients with CLAI and sinus tarsi pain. Subtalar arthroscopic evaluation for ITCL tear is important for correct diagnosis for CLAI with sinus tarsi pain.

LEVEL OF EVIDENCE

IV.