A novel approach for joint line restoration in revision total ankle arthroplasty based on the three-dimensional registration of the contralateral tibia and fibula.

PURPOSE: The use of total ankle arthroplasty (TAA) is increasing over time, as so will the need for revision TAAs in the future. Restoration of the ankle joint line (JL) in revision TAA is often difficult due to severe bone loss. This study analyzed the accuracy of a three-dimensional (3D) registration of the contralateral tibia and fibula to restore the ankle joint line (JL) and reported side-to-side differences of anatomical landmarks. METHODS: 3D triangular surface models of 96 paired lower legs underwent a surface registration algorithm for superimposition of the mirrored contralateral lower leg onto the original lower leg to approximate the original ankle JL using a proximal, middle and distal segment. Distances of the distal fibular tip, anterior and posterior medial colliculus to the JL were measured and absolute side-to-side differences reported. Anterior lateral distal tibial angle (ADTA) and lateral distal tibial angle (LDTA) were measured. RESULTS: Mean JL approximation was most accurate for the distal segment (0.1 ± 1.4 mm (range: -3.4 to 2.8 mm)) and middle segment (0.1 ± 1.2 mm (range: -2.8 to 2.5 mm)) compared to the proximal segment (-0.2 ± 1.6 mm (range: -3.0 to 4.9 mm)) (p = 0.007). Distance of the distal fibular tip, the anterior, and posterior medial colliculus to the JL, ADTA and LDTA yielded no significant side-to-side differences (n.s.). CONCLUSION: 3D registration of the contralateral tibia and fibula reliably approximated the original ankle JL. The contralateral distal fibular tip, anterior and posterior medial colliculi, ADTA and LDTA can be used reliably for the planning of revision TAA with small side-to-side differences reported. LEVEL OF EVIDENCE: IV.

Mid- to long-term results of total ankle replacement in patients with haemophilic arthropathy: A 10-year follow-up.

INTRODUCTION: Haemophilic ankle arthropathy is caused by recurrent spontaneous joint haemorrhaging and leads to pain, deformity and loss of function. In the presence of advanced articular deterioration, therapeutic options are confined to either arthroplasty or arthrodesis, the latter still being referred to as the procedure of choice. However, total ankle replacement (TAR) has recently gained acceptance as an alternative. AIM: To investigate the mid- to long-term results of TAR in haemophilic ankle arthropathy. MATERIALS AND METHODS: Seventeen TARs in 14 male patients (mean age: 43 years [range, 27.4-57.6]), implanted between 1998 and 2012, were retrospectively analysed. Implant survival was estimated using Kaplan-Meier analysis. Haemophilic/viral status, complications and revision surgeries were recorded. Follow-up assessment of 12 TARs was performed 9.6 years (range, 3.3-17.8) postoperatively, including clinical examination, pain and satisfaction scales, the American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score, and the SF-36. Radiographic evaluation of pre- and follow-up radiographs was conducted. RESULTS: Estimated implant survival was 94% at 5, 85% at 10 and 70% at 15 years, respectively. Three cases required revision surgery. At follow-up, 9.6 years (range, 3.3-17.8) postoperatively, the level of satisfaction was 76% (range, 50-100) and of pain 2/10 (range, 0-6) on the VAS. Range of motion had increased significantly (P = .037). The SF-36 summary scores were comparable to those of a matched standard population. The AOFAS hindfoot score averaged 81 points (range, 73-90). All radiographs revealed component loosening or periprosthetic radiolucency. CONCLUSION: Total ankle replacement in the presence of advanced haemophilic arthropathy is a viable treatment option with favourable mid-/long-term results, maintaining mobility of the ankle joint.