The influence of footwear on functional outcome after total ankle replacement, ankle arthrodesis, and tibiotalocalcaneal arthrodesis

Background: Gait analysis after total ankle replacement and ankle arthrodesis is usually measured barefoot. However, this does not reflect reality. The purpose of this study was to compare patients barefoot and with footwear. Methods: We compared 126 patients (total ankle replacement 28, ankle arthrodesis 57, and tibiotalocalcaneal arthrodesis 41) with 35 healthy controls in three conditions (barefoot, standardized running, and rocker bottom shoes). Minimum follow-up was 2 years. We used dynamic pedobarography and a light gate. Main outcome measures: relative midfoot index, forefoot maximal force, walking speed. Findings: The relative midfoot index decreased in all groups from barefoot to running shoes and again to rocker bottom shoes (p < 0.001). The forefoot maximal force increased wearing shoes (p < 0.001), but there was no difference between running and rocker bottom shoes. Walking speed increased by 0.06 m/s with footwear (p < 0.001). Total ankle replacement and ankle arthrodesis were equal in running shoes but both deviated from healthy controls (total ankle replacement/ankle arthrodesis smaller RMI p = 0.07/0.017; increased forefoot maximal force p = 0.757/0.862; slower walking speed p < 0.001). In rocker bottom shoes, this ranking remained the same except the relative midfoot index merged to similar values. Tibiotalocalcaneal arthrodesis were inferior in both shoes. Interpretation: Runners are beneficial and the benefit is greater for fusions and replacements. Rocker bottom shoes have little added benefit. Total ankle replacement and ankle arthrodesis were equal but inferior to healthy controls. Tibiotalocalcaneal arthrodesis has an inferior outcome

The biomechanical influence of tibio-talar containment on stability of the ankle joint

Chronic ankle instability (CAI) is a frequent sport orthopaedic entity. Although many risk factors have been studied extensively, little is known how it is influenced by the osseous joint configuration. Based on lateral X-rays, the radius of the talar surface and the tibial coverage of the talus (sector α) were measured on a DICOM/PACS system in 52 patients with CAI and an age- and sex-matched control group. The talar radius was found to be larger in patients with CAI (21.2±2.4mm) than in the control group (17.7±1.9mm; P<0.0001). The tibio-talar sector was smaller in patients with CAI (80°±5.1°) than in the control group (88.4°±7.2°; P<0.0001). The aim of this study is to analyse the biomechanical influence of the clinical data on stability of the ankle joint. A two-dimensional model of the tibio-talar joint in the sagittal plane was developed. The joint configuration was described by the tibio-talar sector (α) and the radius (r) of the talus. The force (F=F BW tan α/2) and energy (E=F BWr [1−cos α/2]) to dislocate the talus out of the tibial plafond were deduced. Ankle stability is a function of the tibio-talar sector: the force necessary to dislocate the joint is decreasing with a smaller sector. The clinical data show that the force needed to dislocate the ankle of CAI patients was 14% weaker than the one needed in the case of healthy subjects (P<0.0001). The energy to dislocate the ankle depends both on the sector and the radius. The clinical data do not show a significant difference between the energy needed to dislocate the joint of CAI patients and the one of healthy subjects. This is because there is a correlation of a small sector and a large radius for CAI ankles. CAI is associated with an unstable osseous joint configuration, which is characterized by a larger radius of the talus and a smaller tibio-talar sector. The findings of the biomechanical model explain the clinical observations and demonstrate how stability of the ankle joint is influenced by the osseous configuration. Surgical ankle ligament stabilization might be more recommended in patients with an unstable osseous configuration as such patients have a disposition for recurrent sprains. Removing anterior osteophytes for anterior impingement should be done carefully in CAI patients because this would decrease the tibial coverage of the talus and thus dispose the talus to dislocate anteriorly. People who have an unstable ankle configuration and who nevertheless engage in activities with high risk of ankle sprains could be asked to wear ankle protecting sports equipmen

Facilitating the interpretation of pedobarography: the relative midfoot index as marker for pathologic gait in ankle osteoarthritic and contralateral feet

Background Pedobarography offers dynamic information about the foot, but the interpretation of its large data is challenging. In a prior study it was shown that attention can be restricted to pedobarographic midfoot load data. We aim to verify this observation in ankle osteoarthritic and contralateral feet. Methods We assessed both feet of 120 patients with end-stage ankle osteoarthritis (OA) and 35 healthy volunteers with AOFAS-score and dynamic pedobarography in barefoot condition. We introduce a new parameter, the Relative Midfoot Index (RMI), representing the depth of the midfoot weighted by the maximal force (MF) in the hindfoot and forefoot. Main outcome measures were the RMI, MF and contact times in the hindfoot, midfoot and forefoot. Ankle OA, contralateral and healthy feet were compared with ANOVA. Results The RMI was significantly smaller in OA feet (0.65 ± 0.19) and contralateral feet (0.69 ± 0.15) than in healthy feet (0.84 ± 0.08, p < 0.0001). There was no significant difference between OA and contralateral feet. The RMI showed a correlation of 0.48 with the AOFAS score. Contralateral and OA feet were significantly different from healthy feet (p < 0.001) in all parameters except the hindfoot MF. An RMI <0.8 showed a positive predictive value of 80% and sensitivity of 78% for being unhealthy. Conclusion The RMI assists the interpretation of pedobarographic parameters and provides a user-friendly indicator for unhealthy foot conditions with a cut-off value of 0.8. The contralateral feet of ankle OA patients differed significantly from healthy feet and are therefore not suitable as control group

Can Porous Tantalum Be Used to Achieve Ankle and Subtalar Arthrodesis?: A Pilot Study

A structural graft often is needed to fill gaps during reconstructive procedures of the ankle and hindfoot. Autograft, the current gold standard, is limited in availability and configuration and is associated with donor-site morbidity in as much as 48%, whereas the alternative allograft carries risks of disease transmission and collapse. Trabecular metal (tantalum), with a healing rate similar to that of autograft, high stability, and no donor-site morbidity, has been used in surgery of the hip, knee, and spine. However, its use has not been documented in foot and ankle surgery. We retrospectively reviewed nine patients with complex foot and ankle arthrodeses using a tantalum spacer. Minimum followup was 1.9years (average, 2years; range, 1.9-2.4years). Bone ingrowth into the tantalum was analyzed with micro-CT in three of the nine patients. All arthrodeses were fused clinically and radiographically at the 1- and 2year followups and no complications occurred. The American Orthopaedic Foot and Ankle Society score increased from 32 to 74. The micro-CT showed bony trabeculae growing onto the tantalum. Our data suggest tantalum may be used as a structural graft option for ankle and subtalar arthrodesis. All nine of our patients achieved fusion and had no complications. Using tantalum obviated the need for harvesting of the iliac spine. Level of Evidence: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidenc

Can Complications of Titanium Elastic Nailing With End Cap for Clavicular Fractures Be Reduced?

Background: We found treatment of clavicular midshaft fractures using titanium elastic nails (TENs) in combination with postoperative free ROM was associated with a complication rate of 78%. The use of end caps reduced the rate to 60%, which we still considered unacceptably high. Thus, we explored an alternative approach. Questions/purposes: We investigated whether (1) the complication rate could be reduced by cautious lateral advancement of the TENs, intraoperative oblique radiographs to rule out lateral perforation, and limited ROM postoperatively; (2) fluoroscopy time could be reduced; and (3) shoulder function would be reasonable. Patients and Methods: From March 2006 to December 2009, we treated 44 patients with midshaft clavicular fractures with TENs and end caps. In the first group (n = 15), the TEN was advanced laterally using an oscillating drill. The patients were permitted free ROM. In the second group (n = 29), the TEN was advanced by hand, conversion to open reduction followed two failed closed attempts and lateral perforation was checked with an intraoperative oblique radiograph. Furthermore, anteversion and abduction of the shoulder were limited to 90° for the first 6weeks. Minimum followup was 12months (mean, 16.7months; range, 12-28months). Results: The total complication rate was reduced from nine of 15 in the first group to five of 29 in the second group. Medial perforations ceased with the use of the end cap. Fluoroscopy time was reduced from a mean of 10 to 4 minutes by converting to open reduction after two failed closed attempts. All but three patients exhibited full shoulder ROM at three months and these three had a slight deficit of 10° to 20° in anteversion and/or abduction. At last followup, the mean American Shoulder and Elbow Surgeons score was 92 (range, 88-100) and the Disability of the Arm, Shoulder, and Hand score 1.4 (range, 0-12.5). Conclusions: Cautious insertion of the TENs, intraoperative oblique radiographs, and limiting the ROM for 6weeks postoperatively reduced the complication rate. Using TENs with end caps for midshaft clavicular fractures is minimally invasive while associated with comparable complication rates and function to plate osteosynthesis. Level of Evidence: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidenc

Does Alignment in the Hindfoot Radiograph Influence Dynamic Foot-floor Pressures in Ankle and Tibiotalocalcaneal Fusion?

Background: The Saltzman-el-Khoury hindfoot alignment view (HAV) is considered the gold standard for assessing the axis from hindfoot to tibia. However, it is unclear whether radiographic alignment influences dynamic load distribution during gait. Questions/purposes: We evaluated varus-valgus alignment by the HAV and its influence on dynamic load distribution in ankle and tibiotalocalcaneal (TTC) arthrodesis. Patients and Methods: We clinically assessed 98 patients (ankle, 56; TTC, 42) with SF-36 and American Orthopaedic Foot and Ankle Society (AOFAS) scores, visual hindfoot alignment, HAV angle, and dynamic pedobarography using a five-step method. For comparison, 70 normal feet were evaluated. Minimum followup was 2years (average, 4.11years; range, 2-6years). Results: The mean HAV angle was −0.8°±7.8° for ankle and −1.2°±6.9° for TTC arthrodesis. The HAV angle correlated with pedobarographic load distribution (r=0.35-0.53). Radiographic alignment did not influence SF-36 or AOFAS scores; however, load distribution correlated to qualities of these scores. Visual alignment only predicted the corresponding HAV angle in 48%. To reproduce the dynamic load of healthy subjects, HAV angles of 5° to 10° valgus were needed. Conclusions: Visual positioning is inadequate to determine intraoperative positioning and resulted in a varus position with a relatively large SD. The HAV should be used to assess the hindfoot alignment correctly. HAV angles of 5° to 10° valgus are needed to reproduce a physiologic gait patter

The influence of footwear on functional outcome after total ankle replacement, ankle arthrodesis, and tibiotalocalcaneal arthrodesis

Background: Gait analysis after total ankle replacement and ankle arthrodesis is usually measured barefoot. However, this does not reflect reality. The purpose of this study was to compare patients barefoot and with footwear. Methods: We compared 126 patients (total ankle replacement 28, ankle arthrodesis 57, and tibiotalocalcaneal arthrodesis 41) with 35 healthy controls in three conditions (barefoot, standardized running, and rocker bottom shoes). Minimum follow-up was 2 years. We used dynamic pedobarography and a light gate. Main outcome measures: relative midfoot index, forefoot maximal force, walking speed. Findings: The relative midfoot index decreased in all groups from barefoot to running shoes and again to rocker bottom shoes (p b 0.001). The forefoot maximal force increased wearing shoes (p b 0.001), but there was no difference between running and rocker bottom shoes. Walking speed increased by 0.06 m/s with footwear (p b 0.001). Total ankle replacement and ankle arthrodesis were equal in running shoes but both deviated from healthy controls (total ankle replacement/ankle arthrodesis smaller RMI p = 0.07/0.017; increased forefoot maximal force p = 0.757/0.862; slower walking speed p b 0.001). In rocker bottom shoes, this ranking remained the same except the relative midfoot index merged to similar values. Tibiotalocalcaneal arthrodesis were inferior in both shoes. Interpretation: Runners are beneficial and the benefit is greater for fusions and replacements. Rocker bottom shoes have little added benefit. Total ankle replacement and ankle arthrodesis were equal but inferior to healthy controls. Tibiotalocalcaneal arthrodesis has an inferior outcome

Can Porous Tantalum Be Used to Achieve Ankle and Subtalar Arthrodesis?: A Pilot Study

A structural graft often is needed to fill gaps during reconstructive procedures of the ankle and hindfoot. Autograft, the current gold standard, is limited in availability and configuration and is associated with donor-site morbidity in as much as 48%, whereas the alternative allograft carries risks of disease transmission and collapse. Trabecular metal (tantalum), with a healing rate similar to that of autograft, high stability, and no donor-site morbidity, has been used in surgery of the hip, knee, and spine. However, its use has not been documented in foot and ankle surgery. We retrospectively reviewed nine patients with complex foot and ankle arthrodeses using a tantalum spacer. Minimum followup was 1.9 years (average, 2 years; range, 1.9–2.4 years). Bone ingrowth into the tantalum was analyzed with micro-CT in three of the nine patients. All arthrodeses were fused clinically and radiographically at the 1- and 2 year followups and no complications occurred. The American Orthopaedic Foot and Ankle Society score increased from 32 to 74. The micro-CT showed bony trabeculae growing onto the tantalum. Our data suggest tantalum may be used as a structural graft option for ankle and subtalar arthrodesis. All nine of our patients achieved fusion and had no complications. Using tantalum obviated the need for harvesting of the iliac spine

Complications After Resection of Os Trigonum or Posterior Talar Process

Category: Sports Introduction/Purpose: The resection of os trigonum or posterior talar process for posterior ankle impingement is a technically easy and frequent operation. So far, the scientific literature has focused only on the surgical approach and perioperative problems. However, the author has encountered unfavorable followup results (professional athletes had to stop their career), which also other surgeons tell to have encountered. This study aims to describe for the first time this complication rate and possible reasons therefore. Methods: From 3/11 to 7/15 29 patients (17male, 12 female, 32+/-14 years) with 30 feet were operated (22 endoscopic, 8 open resections). Average followup was 27+/-13 months. All charts and pre- and postoperative radiographs were retrospectively evaluated. Patients were grouped into “no complications”, “minor temporary (< 3 months)”, “major follow up (end of athletic career)” complications. The following radiographic parameters were measured referenced on the intersection of the talar radius with the calcaneus (Fig. 1): (1) length of posterior talar process/ os trigonum, (2) length of the calcaneus below the posterior process/os trigonum, (3) length of the uncovered subtalar joint after resection. Results: The major complication rate was 13.3% (4 of 30 feet, 2 os trigonum, 2 posterior talar process): all 4 had symptomatic talar edema and 3 of 4 had symptomatic subtalar osteoarthritis. 1 minor complication (persistent pain for 3 months) was found. The length of the posterior talar process was preoperatively 9.37 +/- 2.89 mm (os trigonum 8.62+/- 2.62 mm) postoperatively 0.64+/-1.8 mm. The length of the posterior calcaneus preoperatively was 8.35 +/- 4.63 mm, postoperatively 1.97 +/-3.0 mm. The uncovered subtalar joint surface postoperatively was 1.77+/- 2.92 mm. All patients with major complications showed retrospectively what we call the “deadly configuration”: the radius of the talus ends within the subtalar joint. Consequently the free subtalar joint surface was significantly larger (6.4 mm +/- 3.33) in feet with major complications than in feet without (1.06 mm +/- 2.15, P < 0.001). Feet without complications but with this deadly configuration (7/26) had a lower free subtalar surface (3.27 mm +/- 1.81, P=0.09) than feet with major complications. Conclusion: The resection of os trigonum or posterior talar process has a high complication rate of 13.3% with symptomatic talar edema and subtalar osteoarthritis at follow up which can be career-ending in professional athletes. The only risk factor found was what we call the “deadly configuration” characterized by the ending of the talar radius into the subtalar joint. In such cases, the resection has to be made sparingly preferably not anterior into the subtalar joint and patients have to be informed about this possible unfavorable course

Pes Planovarus – The Description of a New Foot Form

Category: Hindfoot Introduction/Purpose: In classic anatomy textbooks probably based on dissections of European executed convicts it is written, that according to the direction of the subtalar joint, a deformity of the foot is generally going either into supination (cavovarus foot) or pronation (planovalgus foot). However today we live in a multiethnic society and the author has encountered feet with hindfoot varus and flat mid- and forefoot, without mueller-weiss-syndrome. This deformity should theoretically not exist and has not been described in the literature yet. Its treatment is unclear. Methods: From 8/2012 to 8/2015 984 new patients were seen in the clinic and included in the study if they showed clinically a hindfoot varus and flat mid-/forefoot on exam. 29 patients (2.9%) with 38 feet were identified (44.6+/-16.2 years, 12 male/17 female). Their main complaints and therapy were retrospectively analyzed. Two independent observers (intraobserver variability ICC 0.998) measured on a DICOM/PACS-monitor the following radiographic parameters (Fig. 1): (1) position in the Saltzman- view, (2) talus-metatarsal-1 angle dorso-plantar (dp) and lateral, (3) talus-calcaneus angle dp and lateral, (4) calcaneal pitch angle. Standard values were taken from the literature. Results: Main complaints were chronic ankle instability (n=22), pain in sports (n=18), achillestendon-tendinitis (n=14), heel pain (n=14), hallux valgus (n=10), metatarsalgia (n=8), midfoot pain (n=6), posterior tibial tendon tendinitis (n=3), midfoot osteoarthritis (n=3). There was no mueller-weiss disease. 25 feet were treated conservatively, 13 with operation. Radiological results: The hindfoot alignment view was significantly in varus 6.57+/-3.74mm (standard 1.6+/-7.2mm, P < 0.001), the talus-MT1 angel lateral was significantly flat with 5.97+/-8.3° towards a negative arch (standard 8.4+/-5.85° positive arch, P < 0.001), the talus- MT1- angle dp was 2.4+/-8.2° in abduction (standard 7.7+/-8.2°, P=0.2), the calcaneus pitch angle was 18.63+/-6.45° (standard 24.5+/- 3.0, P < 0.001), the talus-calcaneus angle lateral was 48.13+/-6.76° (standard 43.4+/-7.1°, P < 0.001), the talus calcaneus angle dp was 25.35+/-8.22° (standard 24.1+/-5.7+, P=0.38). Conclusion: We found in 2.9% of our patients this new foot form, which is significantly different from standard feet characterized by a simultaneous hindfoot varus and flatfoot with negative arch. This seems paradox, as this is not in line with the axis of the subtalar joint. These feet pose a difficulty in treatment as for example a correction of the hindfoot varus in chronic ankle instability would increase the flatfoot and the correction of flatfoot in midfoot pain/metatarsalgia/heel pain would increase the hindfoot varus. Therefore conservative treatment was the primary choice because surgery would include a simultaneous correction of both deformities. Further research is necessary