Artrosis de tobillo y su tratamiento con artroplastía total de tobillo

Durante la última década ha crecido la inquietud en relación a los resultados a largo plazo de la artrodesis de tobillo como tratamiento para la artrosis de esta articulación, lo que ha generado nuevamente interés en la Artroplastía Total de Tobillo (ATT). Nuevos han sido diseñados, los cuales están enfocados en reproducir la anatomía normal del tobillo, cinemática de la articulación; estabilidad de los ligamentos y alineación mecánica. Resultados clínicos alentadores para artroplastias de segunda generación son prometedores para pacientes con osteoartritis avanzada del tobillo. Sin embargo, las características mecánicas y fisiológicas únicas de la articulación del tobillo siguen siendo un desafío. A la fecha, los fracasos de implantes de tobillo continúan siendo más altos que implantes para otras articulaciones. De cierto modo, esto puede estar relacionado con la inhabilidad del cirujano para restaurar adecuadamente el rol estabilizador crítico de los ligamentos junto con una reproducción insuficiente de la mecánica normal de la articulación del tobillo. Sin embargo, la selección adecuada de pacientes, planificación preoperatoria cuidadosa, tratamiento apropiado de trastornos asociados (por ejemplo, inestabilidad, mal alineación y osteoartritis de articulaciones adyacentes) y la minimización de complicaciones perioperatorias, ayudarán a maximizar la posibilidad de un resultado exitoso

Ankle arthritis and the treatment with ankle replacement

Concerns about the long-term outcomes of ankle arthrodesis, has created renewed interest in total ankle replacement over the last decade. New implants have been designed with attention to reproducing normal ankle anatomy, joint kinematics, ligament stability, and mechanical alignment. Encouraging intermediate clinical results for second-generation arthroplasties hold promise for patients with end-stage ankle osteoarthritis. The unique physiological and mechanical characteristics of the ankle joint, however, remain a challenge. Failures of ankle implants are, to date, still higher than implants in otherjoints. To a certain extent, this may be related to the inabilityof a surgeon to adequately restore the critical stabilizing role of the ligaments, as well as to poor reproduction of the normal mechanics of the ankle joint. However, adequate patient selection, careful preoperative planning, appropriate treatment of associated disorders (for example, instability, malalignment, and osteoarthritis of adjacent joints), and minimizing perioperative complications will help to maximize the chance for a successful outcome

Syndesmotic Instability After Total Ankle Replacement

Category: Ankle Arthritis Introduction/Purpose: Total ankle replacement (TAR) evolved over the last decades and has been shown to be an effective concept in the treatment of ankle osteoarthritis (OA). In three-component designs, the second interface between polyethylene insert (PI) and tibial component allows the PI to find its position according the individual physiological properties. This was believed to decrease shear forces within the ankle joint. However, it is not clarified to which extent such an additional degree of freedom may overload the ligamentous structures of the ankle joint over time. This may in particular be the case for the syndesmotic ligaments. Therefore, the purpose of this study was to analyze all ankles after TAR that showed a symptomatic overload of the syndesmotic ligaments and to determine the potential consequences. Methods: Between 2003 and 2017, 31 ankles (females, 17; males 14; mean age 60 [40-79] years) were treated with a tibio-fibular fusion for a symptomatic instability of the syndesmosis. The indication for TAR was posttraumatic OA in 27 (87%), primary OA in 3 (10%), and hemochromatosis in one ankle (3%). The 31 ankles included 23 primary TAR (74%), 6 revision TAR (19%), and two take-down of a fusion and conversion to TAR (7%). Criteria for fusion were the presence of at least two of the followings: (1) tenderness over the syndesmosis, (2) pain while compressing the fibula against the tibia (squeeze test), (3) pain while rotating the foot externally (external rotation test), (4) widening of the syndesmosis on an anteroposterior view. Alignment of TAR (tibial articular surface [TAS] angle) and hindfoot alignment were measured on standard radiographs. Intraoperatively, the syndesmotic instability was confirmed before fusion. The wear of PI was documented. Results: After a mean of 63 (range, 4 – 152) months after TAR, all patients evidenced pain at the level of the syndesmosis of at least 3 months. 25 ankles (81%; 24 after posttraumatic OA) showed a widening of the syndesmotic space and 22 ankles (71%) of the medial clear space with lateral translation of the talus. The PI was seen to overlap the tibial component in 15 ankles (48%). Nine ankles (29%) evidenced cyst formation, and eight ankles (26%) showed a decrease in height of the PI; whereas, in 3 ankles (10%) a fracture of the PI was found. A valgus misalignment of the heel was found in 25 ankles (81%), a valgus TAS in 16 (52%) and a varus TAS in 11 ankles (36%). Conclusion: A syndesmotic instability after a three-component TAR apparently occurred mostly after posttraumatic OA, in particular if the heel was left in valgus. If the talus starts to move lateralward, the PI seems to be at risk for increased wear and finally mechanical failure (Figure 1). Therefore, a valgus misaligned heel should always be corrected during TAR implantation. If there is any sign of syndesmotic instability, a fusion should be considered. Further studies must proof whether in cases with a syndesmotic instability the use of a two-component design will be superior, as it stabilizes the talus in the coronal plane

Novel Double Osteotomy Technique of Distal Tibia for Correction of Asymmetric Varus Osteoarthritic Ankle

Category: Ankle, Ankle Arthritis Introduction/Purpose: A most challenging condition for balancing a varus arthritic ankle is the presence of a defect in the medial tibial plafond. After our initial results with a medial tibial plafond plasty did not fulfill our expectations of success, we hypothesized that adding a correcting supramalleolar osteotomy of the distal tibia would move the loading force to the tibiotalar joint more medially and thus act as an evertor force to the talus. In this study we asked (1) what surgical technique was used in detail; (2) what complications were observed; (3) what is the postoperative pain relief; (4) what is the patients’ mid-term functional outcome including range of motion; (5) what is the patients’ mid-term radiographic outcome including hindfoot alignment and progression of ankle osteoarthritis? Methods: Twenty consecutive patients were included into this study, no patients were lost for follow-up with a 4-year minimum required by the study. The mean age of the patients was 44 ± 12 years (range, 17-60 years). Followup averaged 5.9 ± 2.1 years (range, 4-11.2 years). All intraoperative and postoperative complications were recorded. The postoperative pain relief was assessed using a visual analog scale (VAS). Functional outcomes were assessed using the American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score and by measuring the ankle’s range of motion. Weight-bearing radiographs were used to assess osteotomy union and hindfoot alignment. Hindfoot alignment was assessed by measurement of the tibial ankle surface (TAS) angle, the tibiotalar (TT) angle, tibial lateral surface (TLS) angle, the tibiotalar tilt, and the moment arm of the calcaneus. Osteoarthritis grading was performed preoperative and postoperatively according to Takakura et al. Results: There were no intraoperative or perioperative complications. All patients had osseous fusion within 6 postoperative months. The average VAS pain score decreased significantly from 7.9 ± 1.3 (range, 6-10) to 1.3 ± 1.6 (range, 0-7). The average AOFAS hindfoot score increased significantly from 49 ± 15 points (range, 36-68) preoperatively to 86 ± 12 points (range, 66-96) postoperatively. The mean preoperative and postoperative ankle range of motion were comparable with 39° ± 11° (range, 25°- 46°) and 38° ± 9° (range, 28°-46°). The varus tilt improved significantly from 19.4° ± 8.2° (range, 6°-32°) to 6.9° ± 3.9° (range, 1°- 12°). According to Takakura’s classification, three ankles deteriorated by one stage, 11 ankles improved by one stage, and six ankles showed no changes. Conclusion: The novel double osteotomy was found to be an efficient and successful method to restore tibiotalar joint congruency and to normalize hindfoot alignment. The key of success of medial tibial plafond plasty may be the move of the joint load medially by the additional supramalleolar correcting osteotomy, thus creating an eversion force to the talus. Further in vitro studies are needed to evaluate these hypotheses

Assessment of progressive collapsing foot deformity using semiautomated 3D measurements derived from weightbearing CT scans

Background: In progressive collapsing foot deformity (PCFD), hind- and midfoot deformities can be hard to characterize based on weightbearing plain radiography. Semiautomated 3-dimensional (3D) measurements derived from weightbearing computed tomography (WBCT) scans may provide a more accurate deformity assessment. In the present study, automated 3D measurements based on WBCT were used to compare hindfoot alignment of healthy individuals to patients with PCFD. Methods: The WBCT scans of 20 patients treated at our institution with either a flexible (N = 10) or rigid (N = 10) PCFD were compared with the WBCT scans of a control group of 30 healthy individuals. Using semiautomated image analysis software, from each set of 3D voxel images, we measured the talar tilt (TT), hindfoot moment arm (HMA), talocalcaneal angle (TCA; axial/lateral), talonavicular coverage (TNC), and talocalcaneal overlap (TCO). The presence of medial facet subluxation as well as sinus tarsi/subfibular impingement was additionally assessed. Results: With the exception of the TCA (axial/lateral), the analyzed measurements differed between healthy individuals and patients with PCFD. The TCA axial correlated with the TNC in patients with PCFD. An increased TCO combined with sinus tarsi impingement raised the probability of predicting a deformity as rigid. Conclusion: Using 3D measurements, in this relatively small cohort of patients, we identified relevant variables associated with a clinical presentation of flexible or rigid PCFD. An increased TCO combined with sinus tarsi impingement raised the probability of predicting a deformity as rigid. Such WBCT-based markers possibly can help the surgeon in decision-making regarding the appropriate surgical strategy (eg, osteotomies vs realignment arthrodesis). However, prospective studies are necessary to confirm the utility of the proposed parameters in the treatment of PCFD

High reliability for semiautomated 3D measurements based on weightbearing CT scans

Background: A reliable assessment of the ankle using weightbearing radiography remains challenging. Semiautomated 3-dimensional (3D) measurements derived from weightbearing computed tomography (WBCT) scans may provide a more reliable approach. Methods: Thirty healthy individuals without any foot and ankle disorder were analyzed. We assessed 6 widely used ankle parameters (4 angles and 2 distances) using either semiautomated 3D (based on WBCT scans) or traditional 2-dimensional (2D; based on conventional radiographs) measurements. The reliability and discrepancy between both techniques were compared using intraclass correlation coefficients and the Bland-Altman method. Results: Five of 6 variables showed a lower reliability when derived from 2D measurements. The mean of 3 variables differed between the techniques: the 3D technique assessed that the talonavicular coverage angle was 18.9 degrees higher, the axial talocalcaneal angle was 5.5 degrees higher, and the talocalcaneal overlap was 3.7 mm lower when compared with 2D measurements. Conclusion: Semiautomated 3D measurements derived from WBCT scans provide more reliable information on ankle alignment compared with 2D measurements based on weightbearing radiographs. Future studies may show to what extent these parameters could contribute to current diagnostic algorithms and treatment concepts

Supramalleolar osteotomy for ankle varus deformity alters subtalar joint alignment

Background: Although correction of ankle and hindfoot deformity after supramalleolar osteotomy has been investigated extensively, the specific effect on the subtalar joint alignment remains elusive. This can be attributed to the limitations of 2-dimensional measurements, which impede an exact quantification of the 3-dimensional subtalar joint alignment. Therefore, we determined both the ankle, hindfoot, and subtalar joint alignment before and after supramalleolar osteotomy using autogenerated 3-dimensional measurements based on weightbearing CT imaging. Methods: Twenty-nine patients with a mean age of 50.4 +/- 10.6 years were retrospectively analyzed in a pre-post study design using weightbearing CT. Inclusion criteria were correction of ankle varus deformity by an opening wedge (n = 22) or dome osteotomy (n = 7). Exclusion criteria consisted of an additional inframalleolar arthrodesis or osteotomy. Corresponding 3-dimensional bone models were reconstructed to compute following autogenerated measurements of the ankle- and hindfoot alignment: tibial anterior surface (TAS), tibiotalar surface (TTS), talar tilt (TT) angle, hindfoot angle (HA). In addition, the talocalcaneal angle (TCA) in the axial (TCA(ax)), sagittal (TCA(sag)), and coronal (TCA(cor)) plane were measured to assess the subtalar joint alignment. Results: The preoperative radiographic parameters of the ankle joint alignment (TAS=88 +/- 4 degrees, TTS=82 +/- 7 degrees, TT=5.8 +/- 4.9 degrees) improved significantly relative to their postoperative equivalents (TAS = 93 +/- 5 degrees, TTS = 88 +/- 7 degrees, TT=4.2 +/- 4.5 degrees; P .05). Conclusion: This study quantified the 3-dimensional ankle, hindfoot, and subtalar joint alignment after a solitary supramalleolar osteotomy. We found alterations in the subtalar joint alignment, which occurred by 2 to 3 degrees in each anatomic plane. However, before recommendations can be given related to inframalleolar procedures in conjunction to supramalleolar osteotomies, further studies on the variation of subtalar joint alignment change are needed

FAI760273-ICMJE – Supplemental material for Intraoperative Findings of Lateral Ligament Avulsion Fractures and Outcome After Refixation to the Fibula

<p>Supplemental material, FAI760273-ICMJE for Intraoperative Findings of Lateral Ligament Avulsion Fractures and Outcome After Refixation to the Fibula by Jasmin Diallo, Joe Wagener, Christine Schweizer, Tamara Horn Lang, Roxa Ruiz and Beat Hintermann in Foot & Ankle International</p