[Diagnostics and Therapy of Ankle Instability]. / Sprunggelenksinstabilität.

Diagnostics and Therapy of Ankle Instability Abstract. Ankle sprains are among the most common musculoskeletal injuries and therefore often treated in the emergency department or in the general practitioner's office. In the majority of cases, the lateral ligamentous complex is affected. If treated correctly, ligamentous ankle injuries have a good prognosis and in about 80% of cases full recovery can be achieved. Risk factors for the development of chronic ankle instability are an inappropriate treatment of the ankle sprain, injury of the deltoid ligament, hyperlaxity and rearfoot deformities (e.g., cavovarus foot). Diagnostics after an ankle sprain include a medical history, focused physical examination, and appropriate imaging. Concomitant injuries such as fractures, osteochondral defects or tendon injuries should be excluded. Ankle sprains are usually treated conservatively, involving bracing or immobilization - depending on the severity of ligament damage - followed by functional rehabilitation. Patients with chronic ankle instability refractory to conservative treatment, should be considered for surgical interventions.

[Update on total ankle arthroplasty]. / Update Sprunggelenksprothetik.

Update on total ankle arthroplasty Abstract. Ankle arthritis is a major cause of impaired quality of life and affects approximately 1 % of the world population. Treatment options in end stage arthritis include ankle arthrodesis and total ankle replacement. As ankle arthroplasty preserves motion at the ankle joint it has become a popular alternative to fusion. Due to modern implantation techniques and improved prothesis designs ankle arthroplasty has emerged as a safe and effective treatment of ankle arthritis.

Subtalar joint alignment in ankle osteoarthritis.

BACKGROUND: Although it has been proposed that in mid-stage ankle osteoarthritis, the subtalar joint can compensate for deformities above the ankle joint, the evidence is weak. We thus investigated subtalar joint alignment in different stages of ankle osteoarthritis using weightbearing computed tomography (CT) scans. METHODS: The subtalar joint of 88 patients with osteoarthritis of the ankle joint and a control group of 27 healthy volunteers were assessed. Subgroups were performed according to the ankle deformity (varus and valgus) and stage of ankle joint osteoarthritis. Subtalar joint alignment was assessed on weightbearing CT scans. RESULTS: A more valgus subtalar joint alignment was found in patients with varus ankle osteoarthritis. No significant difference of the subtalar joint alignment was evident when comparing different stages of ankle osteoarthritis. CONCLUSIONS: Varus ankles compensate in the subtalar joint for deformities above the ankle joint. Compensation does not correlate with the stage of ankle osteoarthritis.

Material and biofilm load of K wires in toe surgery: titanium versus stainless steel.

BACKGROUND: Recurrence rates for toe deformity correction are high and primarily are attributable to scar contractures. These contractures may result from subclinical infection. QUESTIONS/PURPOSES: We hypothesized that (1) recurrence of toe deformities and residual pain are related to low-grade infections from biofilm formation on percutaneous K wires, (2) biofilm formation is lower on titanium (Ti) K wires compared with stainless steel (SS) K wires, and (3) clinical outcome is superior with the use of Ti K wires compared with SS K wires. METHODS: In this prospective nonrandomized, comparative study, we investigated 135 lesser toe deformities (61 patients; 49 women; mean ± SD age, 60 ± 15 years) temporarily fixed with K wires between August 2010 and March 2011 (81 SS, 54 Ti). K wires were removed after 6 weeks. The presence of biofilm-related infections was analyzed by sonication. RESULTS: High bacterial loads (> 500 colony-forming units [CFU]/mL) were detected on all six toes requiring revision before 6 months. Increased bacterial load was associated with pain and swelling but not recurrence of the deformity. More SS K wires had greater than 100 CFU/mL bacteria than Ti K wires. For K wires with a bacterial count greater than 100 CFU/mL, toes with Ti K wires had a lower recurrence rate, less pain, and less swelling than toes with SS K wires. CONCLUSIONS: Ti K wires showed superior clinical outcomes to SS K wires. This appears to be attributable to reduced infection rates. Although additional study is needed, we currently recommend the use of Ti K wires for the transfixation of toe deformities. LEVEL OF EVIDENCE: Level II, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Surgical technique: talar neck osteotomy to lengthen the medial column after a malunited talar neck fracture.

BACKGROUND: Treatment of malunited talar neck fractures is challenging, and few studies address anatomic reconstruction as an alternative to arthrodesis. We describe a new surgical approach attempting to improve function and avoid development of degenerative changes in the adjacent joints. DESCRIPTION OF TECHNIQUE: Indications included malunited talar neck fractures. Through a dorsomedial approach, a correcting osteotomy with interposition of an autograft or allograft was performed and internally fixed using buttress plate and/or screws. METHODS: We retrospectively reviewed seven patients in whom the new technique was indicated for malunited talar neck fractures. The mean age of the patients was 42 years (range, 17-60 years). We analyzed the patients clinically and radiographically with a minimum followup of 2.5 years (mean, 4 years; range, 2.5-9.8 years). RESULTS: At followup, all patients experienced substantial pain relief. No development of avascular necrosis or radiographic arthritic changes were observed. Physical categories of the SF-36 score showed great improvements. The American Orthopaedic Foot and Ankle Society hindfoot score increased from 41±19 preoperatively (range, 20-62) to 84±11 (range, 68-97). The average talar-first metatarsal angle increased dramatically. All but one patient showed radiographic union of the talar osteotomy. Implant removal was performed in three patients. CONCLUSIONS: Based on these observations, correctional osteotomy is a reasonable option for treating patients with malunited talar neck fractures by providing a pain-free foot with good function, recreating anatomy, and involving a low risk of postoperative complications. Further studies with longer followups are required to confirm these findings persist with time. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Outcomes of Combined Posterior Tibial Tendon Tendoscopy and Medializing Calcaneal Osteotomy for Stage IA Progressive Collapsing Foot Deformity.

BACKGROUND: Posterior tibial tendon (PTT) tendoscopy and medializing calcaneal osteotomy (MCO) are among the available techniques for patients presenting with symptomatic flexible hindfoot valgus (stage IA) progressive collapsing foot deformity (PCFD). The aim of this study was to determine clinical and radiographic outcomes of combined PTT tendoscopy and MCO for patients presenting with symptomatic stage IA PCFD. METHODS: A retrospective cohort study was performed in order to determine clinical and radiographic outcomes of 30 combined PTT tendoscopies and MCO on 27 patients presenting with symptomatic stage IA PCFD, with a minimum follow-up of 24 months. Patient satisfaction was assessed at last available follow-up as very satisfied, satisfied, and unsatisfied. Clinical assessment was performed evaluating preoperative and last available follow-up visual analog scale for pain (VAS-P), Foot and Ankle Outcome Score (FAOS), and the 36-Item Short Form Health Survey (SF-36). Magnetic resonance imaging (MRI) was performed preoperatively on all patients. Standard weightbearing anteroposterior, lateral, and long axial view radiographs of the foot and ankle were taken preoperatively, immediate postoperatively, at 6 weeks, 3 months, 6 months, 1 year postoperatively, and last follow-up evaluation available for each patient. RESULTS: The mean follow-up was 38.6 (range, 26-62) months. We registered 27 very satisfied, 1 satisfied, and 2 unsatisfied patients. There was statistically significant improvement on all clinical scores (VAS-P, FAOS and SF-36), as well as on lateral talo-first metatarsal and hindfoot alignment angles. We found low-grade PTT tears in 5 patients (16.67%) in whom preoperative MRI documented PTT tenosynovitis alone. CONCLUSION: We found that combined PTT tendoscopy and MCO provide significant clinical and radiographic improvement for patients presenting with symptomatic stage IAB PCFD. PTT tendoscopy should be considered in the treatment of all surgically addressed flexible valgus feet as it detects tendon tears which are frequently missed on an MRI. LEVEL OF EVIDENCE: Level IV, retrospective case series.

The reliability and validity of radiographic measurements for determining the three-dimensional position of the talus in varus and valgus osteoarthritic ankles.

OBJECTIVE: To assess the most accurate radiographic method to determine talar three-dimensional position in varus and valgus osteoarthritic ankles, we evaluated the reliability and validity of different radiographic measurements. MATERIALS AND METHODS: Nine radiographic measurements were performed blindly on weight-bearing mortise, sagittal, and horizontal radiographs of 33 varus and 33 valgus feet (63 patients). Intra- and interobserver reliability was determined with the intraclass coefficient (ICC). Discriminant validity of measurements between varus and valgus feet was assessed with effect size (ES). Convergent validity (Pearson's r) was evaluated by correlating measurements to the dichotomized varus and valgus groups. Obtained measurements in both groups were finally compared with each other and with 30 control feet. RESULTS: Reliability was excellent (ICC > 0.80) in all but two measurements. Whereas frontal plane validity was excellent (ES and r > 0.80), horizontal and sagittal measurements showed poor to moderate validity (ES and r between 0.00 and 0.60). Four measurements were significantly different among all groups (p < 0.05). Talar positional tendency was found towards dorsiflexion or endorotation in the varus group and towards plantarflexion or exorotation in the valgus group. The frontal tibiotalar surface angle, sagittal talocalcaneal inclination angle, and horizontal talometatarsal I angle showed the best reliability, validity, and difference among the groups. CONCLUSION: The frontal tibiotalar surface angle, sagittal talocalcaneal inclination angle, and horizontal talometatarsal I angle accurately determine talar three-dimensional radiographic position in weight-bearing varus and valgus osteoarthritic ankles. Careful radiographic evaluation is important, as these deformities affect talar position in all three planes.

Mini-open sinus tarsi approach with percutaneous screw fixation of displaced calcaneal fractures: a prospective computed tomography-based study.

BACKGROUND: Open reduction and internal fixation (ORIF) of calcaneal fractures using an extended lateral approach results in soft tissue disruption and theoretically subtalar joint stiffness. A minimally invasive sinus tarsi approach for posterior facet exposure and percutaneous screw fixation of the calcaneal body has been implemented. This report details the reduction and stability of the internal fixation resulting from this approach. METHODS: Twenty-one consecutive patients (18 male, 3 female, 45 ± 16 years) with 22 calcaneal fractures underwent ORIF with minimal exposure through the sinus tarsi for reduction, lateral plate fixation, and percutaneous screw fixation. There were nine Sanders type II fractures and 13 type III fractures. Sixteen fractures had calcaneocuboid joint involvement. Nineteen patients (19 fractures) were available for follow-up (mean, 32 ± 14 months). Two computed tomography scans were obtained on each patient, one immediately postoperatively and one after a minimum of 1 year, to evaluate reduction and fixation stability, respectively. The posterior facet and calcaneocuboid joint were graded excellent, good, fair, or poor, according to articular step, defect, and angulation. Any change was considered loss of stability. Similarly, on a conventional two-dimensional radiograph, more than 5° of Bohler's angle difference was defined as loss of calcaneal height. RESULTS: Postoperative posterior facet and calcaneocuboid joint reduction was good (step < 1 mm, defect < 5 mm, angulation < 5°) or excellent (no step, defect, angulation) in 14/22 (64%) and 11/16 fractures, respectively. At follow-up, no loss of reduction at the posterior facet and calcaneocuboid joint was noted. More than 5° of Bohler's angle decrease was found in three patients. CONCLUSION: Even complex calcaneal fractures can be sufficiently exposed by a minimally invasive sinus tarsi approach for anatomic reduction and stable fixation. Most patients had good or excellent functional results, which may have resulted from minimal soft tissue disruption.

Patient-Specific Instrumentation vs Standard Referencing in Total Ankle Arthroplasty: A Comparison of the Radiologic Outcome.

BACKGROUND: Existing literature on the superiority of patient-specific instrumentation (PSI) in total ankle arthroplasty (TAA) over standard referencing (SR) is limited. Advantages presented include better implant alignment, shorter operating times, and increased accuracy of implant size prediction. The aim of this retrospective study was to analyze PSI in the hands of an experienced foot and ankle surgeon new to both PSI and SR for this specific implant, in regard to determining implant alignment, operative times, and radiologic short-term outcome and predicting implant size for tibial and talar components. METHODS: Twenty-four patients undergoing TAA using PSI were compared to 25 patients using SR instrumentation. Outcome measures included alignment of the tibial component (α coronal plane, γ sagittal plane), the tibiotalar tilt (ß), and the talar offset x on the sagittal view as well as the presence of radiolucent lines, operation time, and wound healing. Postoperative outcome was assessed at 6 weeks, 4 months, and 1 year postoperatively. RESULTS: Implant positioning was similar in both groups, and no advantage in regard to the operative time could be seen when comparing TAA using PSI to SR. Implant size prediction was more reliable for the tibia than for the talus. Three patients (1 from the SR group and 2 from the PSI group) showed radiolucent lines around the tibial component. Two patients (both SR group) suffered delayed wound healing, albeit not requiring any additional measures. CONCLUSION: The PSI method did not show an advantage over SR in regard to positioning of the components or the duration of the surgery. The current study suggests that no initial advantage of PSI over SR are to be expected in standard total ankle replacement. LEVEL OF EVIDENCE: Level III, retrospective study.

Difference in orientation of the talar articular facets between healthy ankle joints and ankle joints with chronic instability.

Since both the talocrural and subtalar joints can be involved in chronic ankle instability, the present study assessed the talar morphology as this bone is the key player between both joint levels. The 3D orientation and curvature of the superior and the posteroinferior facet between subjects with chronic ankle instability and healthy controls were compared. Hereto, the talus was segmented in the computed tomography images of a control group and a chronic ankle instability group, after which they were reconstructed to 3D surface models. A cylinder was fitted to the subchondral articulating surfaces. The axis of a cylinder represented the facet orientation, which was expressed by an inclination and deviation angle in a coordinate system based on the cylinder of the superior talar facet and the geometric principal axes of the subject's talus. The curvature of the surface was expressed as the radius of the cylinder. The results demonstrated no significant differences in the radius or deviation angle. However, the inclination angle of the posteroinferior talar facet was significantly more plantarly orientated (by 3.5°) in the chronic instability group (14.7 ± 3.1°) compared to the control group (11.2 ± 4.9°) (p < 0.05). In the coronal plane this corresponds to a valgus orientation of the posteroinferior talar facet relative to the talar dome. In conclusion, a more plantarly and valgus orientated posteroinferior talar facet may be associated to chronic ankle instability.

Total ankle replacement in obese patients: component stability, weight change, and functional outcome in 118 consecutive patients.

BACKGROUND: Obesity is a growing problem in Europe and the United States. While obesity has been linked to poor outcomes after total knee or hip replacement, there are no data addressing outcomes in obese patients who underwent total ankle replacement (TAR). METHODS: This retrospective chart review included 118 patients (123 ankles) with a minimum body mass index (BMI) of 30 kg/m2 who underwent TAR between May 2000 and June 2008. There were 61 male (51.7%) and 57 female (48.3%) patients with a mean age of 59.8 +/- 11.6 years (range, 25.4 to 85.0). All patients were evaluated pre- and postoperatively (mean followup 67.7 +/- 27.0 months; range, 29 to 126). Radiological outcomes were assessed using standardized weightbearing radiographs. Clinical outcomes were assessed using the visual analogue scale (VAS) and American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot scale. RESULTS: There were nine intraoperative complications. All patients experienced significant pain relief (VAS change from 7.0 +/- 1.7 to 1.4 +/- 1.1, p < 0.001) and functional improvement (AOFAS score change from 35.4 +/- 14.9 to 75.4 +/- 9.6, p < 0.001; total ROM change from 26.9 +/- 13.7 to 35.3 +/- 8.1 degrees, p < 0.001). BMI measured preoperatively, and at 1 and 2 years postoperatively was 32.9 +/- 2.5 (range, 30.0 to 40.0) kg/m2, 32.4 +/- 2.4 (range, 28.6 to 41.0) kg/m2, and 32.2 +/- 2.4 (range, 28.6 to 40.5) kg/m2, respectively. Gender had a significant effect on weight loss, but not age or postoperative sports activity. Revision surgery was performed in six patients, resulting in a 6-year survivorship of 93%. CONCLUSION: Our findings confirm that TAR gives significant pain relief and functional improvement. In this study, the survivorship of the prosthesis components was comparable to the results obtained in non-obese patients.

Measurement of the medial distal tibial angle.

BACKGROUND: The aim of this study was to describe the difference between the medial distal tibial angle (MDTA) when measured on whole lower limb radiographs and mortise radiographs of the ankle. MATERIALS AND METHODS: A total of 48 legs were included of 24 healthy volunteers. Standard radiographs were obtained of the whole lower leg. Mortise radiographs were obtained of the ankle. The MDTA was measured on the digitized radiographs by three orthopaedic residents, one orthopaedic surgeon and one biomechanical movement scientist. For each leg, the angles measured from the two images were compared. The inter-observer reliability of each method was calculated. RESULTS: The MDTA as measured on whole lower leg images (94.6 ± 2.6 degrees) was significantly different compared with the angle measured on mortise ankle images (92.1 ± 2.2 degrees) (p < 0.01). The mean measurement difference between observers was less than 1 degree. Reliability of the measurements was good with a high association (κ = 0.85) between observers for the angles measured on the whole lower leg images and also a high association (κ = 0.83) between the observers for the mortise ankle image measurements. CONCLUSION: The MDTA is not the same on whole lower leg images and mortise views of the ankle. There was an excellent interobserver reliability for the angles measured. CLINICAL RELEVANCE: Foot and ankle surgeons should take this into account when planning coronal deformity correction of the distal tibia. We believe whole lower leg images should be used to assess the medial distal tibial angle.

Classification and treatment of supramalleolar deformities.

BACKGROUND: Supramalleolar osteotomies are increasingly popular for addressing asymmetric arthritis of the ankle joint. Still, recommendations for the indication and the use of additional procedures remain arbitrary. We preoperatively grouped different types of asymmetric arthritis into several classes and assessed the usefulness of an algorithm based on these classifications for determining the choice of supramalleolar operative procedure and the risk factors for treatment failure. METHODS: Ninety-two patients (94 ankles) were followed prospectively and assessed clinically and radiographically 43 months after a supramalleolar osteotomy for asymmetric arthritis of the ankle joint. RESULTS: Significant improvement of the clinical scores was found. Postoperative reduction of radiological signs of arthritis was observed in mid-stage arthritis. Age and gender did not affect the outcome. Ten ankles failed to respond to the treatment and were converted to total ankle replacements or fused. CONCLUSIONS: Supramalleolar osteotomies can be effective for the treatment of early and midstage asymmetric arthritis of the ankle joint. However, certain subgroups have a tendency towards a worse outcome and may require additional surgery. Therefore preoperative distinction of different subgroups is helpful for determination of additional procedures.

Effect of supramalleolar varus and valgus deformities on the tibiotalar joint: a cadaveric study.

BACKGROUND: Distal tibia coronal plane malalignment predisposes the ankle joint to asymmetric load. The purpose of this cadaveric study was to quantify changes in pressure and force transfer in an ankle with a supramalleolar deformity. MATERIALS AND METHODS: Seventeen cadaveric lower legs were loaded with 700 N after creating supramalleolar varus and valgus deformities. The fibula was left intact in 11 specimens and osteotomized in six. Tekscan© sensors were used to measure the tibiotalar pressure characteristics. RESULTS: In isolated supramalleolar deformity, the center of force and peak pressure moved in an anteromedial direction for valgus and posterolateral direction for varus deformities. The change was in an anteromedial direction for varus and in a posterolateral direction for valgus deformities in specimens with an osteotomized fibula. CONCLUSION: Two essentially different groups of varus and valgus deformities of the ankle joint need to be distinguished. The first group is an isolated frontal plane deformity and the second group is a frontal plane deformity with associated incongruency of the ankle mortise. CLINICAL RELEVANCE: Our findings underline the complexity of asymmetric osteoarthritis of the ankle joint. In addition, results from this study provide useful information for future basic research on coronal plane deformity of the hindfoot and for determining appropriate surgical approaches.

Simultaneous bilateral total ankle replacement using a 3-component prosthesis: outcome in 26 patients followed for 2­10 years.

BACKGROUND AND PURPOSE: Total ankle replacement is an established surgical procedure in patients with end-stage ankle osteoarthritis. We analyzed complications and medium-term results in patients with simultaneous bilateral total ankle replacement. PATIENTS AND METHODS: 10 women and 16 men, mean age 60 (SD 13) years, were followed for a median of 5 (2-10) years. RESULTS: There were no intraoperative or perioperative complications, with the exception of 1 patient with prolonged wound healing. Major revision surgery was necessary in 6 of the 52 ankles, including 4 revisions of prosthetic components. The average pain score decreased from 6.9 (4-10) to 1.8 (0-4) points. The American Orthopaedic Foot and Ankle Society hindfoot score increased from 32 (SD 14) points preoperatively to 74 (SD 12) points postoperatively. The average range of motion increased from 28° (SD 12) preoperatively to 38° (SD 9) postoperatively. All 8 categories of SF-36 score improved. INTERPRETATION: Simultaneous bilateral total ankle replacement is a suitable method for restoration of function and attainment of pain relief in patients with bilateral end-stage ankle osteoarthritis. The results of this procedure, including complication rates, revision rates, and functional outcome, are comparable to those reported in patients with unilateral total ankle replacement.

Outcomes of Posterior Arthroscopic Subtalar Arthrodesis for Medial Facet Talocalcaneal Coalition.

BACKGROUND: Medial facet talocalcaneal coalition can be a painful condition. This study aimed to determine clinical and radiographic outcomes of posterior arthroscopic subtalar arthrodesis (PASTA) for adult patients presenting with symptomatic medial facet talocalcaneal coalition and normal hindfoot alignment, with a minimal follow-up of 18 months. METHODS: Between June 2017 and July 2019, this procedure was performed on 8 feet (8 patients; mean age, 55 [42-70] years; mean BMI, 29.8 [24.4-45.0] kg/m2). Clinical assessment was performed using Visual Analog Scale for Pain (VAS-P), Foot and Ankle Outcome Score (FAOS) and the 36-Item Short-Form Health Survey (SF-36). Patient satisfaction was assessed at the last available follow-up as "very satisfied", "satisfied" or "unsatisfied". Radiographic analysis was performed using plain radiography, computed tomography (CT) scan and magnetic resonance imaging (MRI). The primary outcome was to determine both clinical and radiographic outcomes. RESULTS: The mean follow-up was 25.1 (18.2-34.2) months. The authors found statistically significant improvement on all clinical scores (VASP-P, FAOS and SF-36). They registered 6 "very satisfied" patients, 2 "satisfied" patients and no "unsatisfied" patient. Fusion of the subtalar joint was observed in all patients by 12 weeks and in 5 of them as soon as 8 weeks postoperatively (mean, 9.5 [8-12] weeks). There were no cases of delayed fusion or nonunion of the subtalar joint, superficial or deep infection, neurovascular damage, thromboembolic event, screw breakage, need for hardware removal or revision surgery. CONCLUSION: This study found that PASTA is a safe and reliable technique for adult patients presenting with symptomatic medial facet talocalcaneal coalition and normal hindfoot alignment, demonstrating and maintaining clinical improvement at an average follow-up of 2 years. LEVEL OF EVIDENCE: Level IV, case series.

Anterior double plating for rigid fixation of isolated tibiotalar arthrodesis.

BACKGROUND: Arthrodesis is the most common procedure used to treat end-stage osteoarthritis of the ankle, particularly in patients with difficult conditions such as poor bone quality. While many techniques are available to fuse the ankle, current recommendations favor the use of internal fixation with screws and/or plates. Despite of progress, the complication rate remains a major concern. Non-union is one difficult problem especially with difficult bone conditions, particularly the loss of bone stock on the talar side. Therefore, fusion of the tibiotalar joint is often extended to the talocalcaneal joint to provide sufficient stability. To preserve the subtalar joint, an anterior double plate system for rigid fixation of isolated tibiotalar arthrodesis was developed. This is a preliminary report on the clinical and radiological outcome with this technique. MATERIALS AND METHODS: Twenty-nine patients (15 men, 14 women; one ankle per patient) were treated from October 2006 to September 2007. We converted 16 ankles with osteoarthritis and difficult bone conditions, four non-united ankle arthrodeses, and nine failed total ankle replacements to an isolated tibiotalar arthrodesis using anterior double plating. If necessary, we used solid allograft to fill bony defects. Outcomes included bone union as assessed by radiographs, pain as indicated by the American Orthopaedic Foot and Ankle Society scores, and patient satisfaction. RESULTS: Solid arthrodesis was achieved after an average of 12.3 (eight to 26) weeks in the 16 ankles without bone graft interposed between the tibia and talus, and 14.3 (range, 8 to 26) weeks in the 13 ankles with interpositional bone allograft. Radiographs showed that the position of arthrodesis obtained at the time of surgery did not change in any patient up to one year after surgery. The mean American Orthopaedic Foot and Ankle Society (AOFAS) Hindfoot Score increased from 37 (range, 20 to 63) preoperatively to 68 (range, 50 to 92) at the last followup. Twenty-seven patients (93%) were satisfied with their outcome and indicated they would have the operation again. No complications were noted. CONCLUSION: The anterior double plating system was shown be a reliable method to achieve solid isolated tibiotalar arthrodesis, even in ankles with difficult conditions such as loss of bone stock due to failed total ankle arthroplasty.

Realignment surgery for valgus ankle osteoarthritis.

OBJECTIVE: Improvement of joint congruence, reduction of pain, slowdown of osteoarthritis progression, and prevention or delay of total ankle arthroplasty or ankle fusion. INDICATIONS: Active patients with lateral valgus ankle joint degeneration. CONTRAINDICATIONS: Patients in poor general condition. Inability to adhere to postoperative non-weight-bearing rehabilitation. Distinct cartilage degeneration of more than half of tibiotalar joint surface. Systemic joint disease. Insufficiency of the deltoid ligament with tibiotalar subluxation malalignment. SURGICAL TECHNIQUE: Depending on stage of deformity: Stage I--collapse of the lateral tibia plafond and/or lateral malleolar gutter with subsequent valgus ankle arthritis: medial closing-wedge osteotomy of the distal tibia. Derotation- lengthening osteotomy in case of fibula malunion. Stage II--excessive calcaneus valgus: add medial sliding calcaneus osteotomy. Stage III--forefoot-induced hindfoot valgus (flatfoot deformity with forefoot abduction): add repair/augmentation of the posterior tibial tendon, superficial delta and spring ligaments; gastrocnemius/triceps release; flexion osteotomy of the first cuneiform or metatarsal bone or fusion of the first tarsometatarsal joint. POSTOPERATIVE MANAGEMENT: Continuous active and passive range of motion starting at the 2nd postoperative day. Removable short leg cast during nights. Partial weight bearing for 6-8 weeks until osseous healing has occurred, followed by gradual return to full weight bearing and activity. RESULTS: 14 patients with stage I, three with stage II, and five with stage III valgus ankle osteoarthritis were treated. In two cases realignment surgery failed and progressive painful arthritis was treated by arthroplasty. The other 20 patients improved at an average follow-up of 4.5 years (range 3-6.5 years). Eight patients (41%) were free of pain. Tibiotalar arthritis and alignment (Takakura Score) improved significantly and correlated with significant improvement of pain (visual analog scale) and function (American Orthopaedic Foot and Ankle Society Score).

Study on the three-dimensional orientation of the posterior facet of the subtalar joint using simulated weight-bearing CT.

The purpose of this study was to describe the normal 3D orientation and shape of the subtalar calcaneal posterior facet. This is not adequately described in current literature. In a supine position both feet of 20 healthy subjects were imaged in a simulated weight-bearing CT. A cylinder and plane were fitted to the posterior facet of the surface model. The orientation of both shapes was expressed by two angles in (1) the CT-based coordinate system with the axis of the foot aligned with the sagittal axis and (2) a coordinate system based on the geometric principal axes of the subject's calcaneus. The subtalar vertical angle was determined in the intersection in three different coronal planes of the cylinder. The cylinder's axis oriented from supero-postero-laterally to infero-antero-medially. The plane's normal directed supero-antero-medially in the CT-based coordinate system, and supero-antero-laterally in the other coordinate system. The subtalar vertical angle was significantly different (p < 0.001) between the three defined coronal planes and increased from anterior to posterior. The mean diameter of the fitted cylinder was 42.0 ± 7.7 mm and the root mean square error was 0.5 ± 0.1 mm. The posterior facet can be modelled as a segment of a cylinder with a supero-postero-lateral to infero-antero-medial orientation. The morphometry of the posterior facet in a healthy population serves as a reference in identifying abnormal subtalar joint morphology. More generally this study shows the need to include the full 3D morphology in assessing the orientation of the subtalar posterior facet. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 9999:1-8, 2018.