End-stage Ankle Arthritis Research Articles

The Ankle-Hindfoot Kinematics of Current Generation Total Ankle Replacement: A Cadaveric Gait Simulation

Category:Ankle ArthritisIntroduction/Purpose:Total ankle replacement (TAR) has developed as a standard treatment option for end-stage ankle arthritis with the primary benefit of pain relief and ankle-hindfoot motion preservation. The current generation of TARs features limited bone resection and improved initial fixation of components to restore physiologic constraint and the anatomic articulation of the ankle. However, the ankle-hindfoot kinematics of current TAR designs compared to the baseline native ankle have not yet been extensively studied. Cadaveric gait simulation is a valuable tool for investigating direct effects of surgical procedures on foot and ankle biomechanics. The objective of this study was to assess whether this current generation TAR system could provide normal ankle-hindfoot kinematics as the baseline native ankle using cadaveric gait simulation.Methods:Eleven mid-tibia cadaveric specimens were secured to a static mounting fixture with a six-degree of freedom robotic platform to simulate gait in native-intact and TAR conditions. A force plate was moved relative to the stationary specimen through an inverse tibial kinematic path calculated from in vivo data while extrinsic tendons were actuated using physiologic loads (Figure 1A). Ankle-hindfoot kinematics were measured from reflective markers attached to bones via surgical pins. TAR was performed using a current generation, fixed-bearing system by a fellowship-trained foot-ankle surgeon using the manufacturer described protocol (PROPHECY Patient-specific instrumentation, Infinity, Wright Medical Technology). Ankle-hindfoot joint kinematics were measured using the same tibial kinematic inputs and muscle forces as the intact condition. Non-parametric, bias-corrected bootstrapping was used to calculate 95% confidence intervals to compare motion between intact and total ankle replacement.Results:Analyses demonstrated no significant difference in average ankle-hindfoot joint kinematics between the intact and TAR conditions (Figure 1B). The result was consistent for the ankle, subtalar, and talonavicular joints, in each plane of motion.Conclusion:These findings demonstrate that the current generation of fixed-bearing TAR can recreate normal ankle-hindfoot kinematics patterns seen in normal ankles. Restoring ankle kinematics can be a significant factor in slowing down the progression of adjacent joint arthritis in the foot. However, it is still inconclusive whether ankle-hindfoot kinematics can be restored in patients with long standing ankle arthritis, and this should be addressed in future studies.

The “Joint Line Height Ratio” Assessing the Ankle Joint Line Level Before and After Total Ankle Replacement

Category:Ankle ArthritisIntroduction/Purpose:n important principle of joint replacement is to restore the joint line to its native level. Previous studies have demonstrated a correlation between clinical outcomes and our ability to restore the joint in total knee arthroplasty. To date, there has been no study to assess restoration of joint height in total ankle replacement (TAR). In addition, there is no accepted method for assess joint line height in patients who undergo TAR. The objective of this study is to develop a reliable radiographic ankle joint line level measurement. Additionally, the measure will be used to evaluate and compare ankle joint line levels seen on pre-TAR, post-TAR, and non-arthritic contralateral ankle radiographs.Methods:One hundred and twelve primary TAR patients with weightbearing preoperative (pre-TAR) and 1-year postoperative (post-TAR) anteroposterior (AP) ankle radiographs were retrospectively reviewed. Patients with bilateral disease, concomitant malleolar osteotomy, and component subsidence were excluded. Two raters measured the vertical intermalleolar distance (VIMD, Figure 1) and the vertical joint line distance (VJLD, Figure 1) for all radiographs (pre-TAR, post-TAR, and contralateral normal ankle) on two separate occasions. The measurement ”joint line height ratio” was calculated as the ratio of the VJLD to the VIMD (Figure 1). Reliability was assessed using intraclass correlation coefficients (ICCs). Pearson correlation test was used to assess the level of correlation between the VJLD and the VIMD. The comparisons of pre-TAR, non-arthritic contralateral ankle, and post- TAR “joint line height ratio” were performed using paired t-tests and considered significantly different if p < 0.05.Results:Inter/intra-rater reliabilities of all measurements were excellent (r>0.9). Pearson correlation test demonstrated strong positive correlations of VIMD and VJLD with r 0.809 for pre-TAR and r 0.756 for post-TAR, p<0.001. Mean(SD) VIMDs for pre- TAR, non-arthritis contralateral ankle, and post-TAR were 17.91(4.79), 18.96(4.67) and 17.37(4.76) mm. Mean(SD) VJLDs for pre- TAR, non-arthritis contralateral ankle, and post-TAR were 26.49(4.64), 25.47(4.12) and 26.70(5.31) mm. Additionally, mean(SD) ”joint line height ratio” for pre-TAR, non-arthritic contralateral, and post-TAR ankle radiographs were 1.54(0.31), 1.39(0.26) and 1.62(0.49). The “joint line height ratio” of pre- and post-TAR was significantly higher compared to non-arthritic contralateral ankle (p 0.0001 and < 0.0001), respectively. No significant difference in ”joint line height ratio” was found between pre- and post-TAR(p = 0.15).Conclusion:The “joint line height ratio” was a reliable tool for assessing the ankle joint line pre and post-TAR. End-stage ankle arthritis leads to an elevated joint line compared to non-arthritic ankle. The joint line level after TAR was preserved to that measured before TAR, but not restored compared to the non-arthritic contralateral ankle. When performing TAR, joint line level restoration should be evaluated compared to the contralateral non-arthritic ankle radiograph. The amount of tibial cut should be minimized as much as possible to prevent further bone loss and ankle joint line elevation.

Influence of Depressive Symptoms on Clinical Outcomes of Total Ankle Arthroplasty

Category:Ankle ArthritisIntroduction/Purpose:Recently, there have been many reports on the relationship between depression and clinical outcome of knee or hip arthroplasty. However, there is no study on the association between depression and total clinical outcome of total ankle arthroplasty (TAA). This study investigated the relationship between depressive symptoms and clinical outcome after TAA.Methods:Forty patients who underwent TAA for end-stage ankle arthritis from July 2014 to July 2017 and were able to follow- up at least 12 months were selected. Depressive symptoms were evaluated using Center for Epidemiologic Studies Depression Scale (CES-D) and Patient Health Questionnaire-9 (PHQ-9). The subjects were divided into Depressive group and Non-depressive group, and the preoperative and postoperative clinical results were compared using a visual analogue scale (VAS), American orthopedic foot and ankle-hindfoot score (AOFAS). The preoperative and postoperative radiological results were also compared using anterior surface angle of distal tibia (TAS), talar tilt of ankle joint (TT), lateral surface angle of distal tibia (TLS), and heel alignment distance (HD).Results:The mean age of the patients was 61.6±18.2 years and the average follow-up period was 24.3±7.3 months. 13 subjects were in Depression group and 27 subjects were in Non-depression group. There was no statistical difference in baseline characteristics between the two groups. Additionally, there was no statistical difference in preoperative VAS and AOFAS between the two groups (p>.05). Preoperative and postoperative VAS and AOFAS showed statistically significant improvement in both groups (p<.05). However, the depressive group showed higher result in postoperative VAS than the Non-depressive group significantly (3.1±2.4 vs 1.4±2.3, p<.05). The postoperative AOFAS was also higher in the non-depressive group significantly (89.3±13.4 vs 95.0±8.1, p<.05). Both groups showed improvement in postoperative radiologic index. Preoperative and postoperative radiologic index showed no difference in both groups.Conclusion:The clinical outcome after TAA was poor in patients with depressive symptoms when compared to patients without depressive symptoms. Since depressive symptoms is a patient-specific factor that result in less improvement in clinical outcomes after TAA, clinical considerations for depressive symptoms are needed prior to TAA surgery.

Miniopen vs Lateral Approach for Ankle Arthrodesis, Which Approach is Superior in Joint Preparation: A Cadaver Study

Category:Ankle, Ankle Arthritis, Arthroscopy, Basic Sciences/BiologicsIntroduction/Purpose:Ankle arthrodesis is a gold standard for end-stage ankle arthritis after conservative managements fail. It may be done through direct anterior, lateral, arthroscopic or mini open approaches. Joint preparation, apposition of joint surfaces and stable fixation are very important for successful outcomes. Ankle arthrodesis maybe associated with infection, chronic pain and nonunion - of these, nonunion is the most common complication reported. Achieving union is of utmost importance while minimizing complications associated with the procedure.Regardless of approach or fixation method, preparation of articular surface is of paramount importance for successful union and may be limited by the approach used. Our study aims to evaluate the difference between direct lateral and dual mini-open approaches (extended arthroscopic portals) in terms of joint preparation.Methods:We used 10 below knee fresh-frozen cadaver legs for this cadaveric study. Ankle joints of five specimens were prepared through the lateral approach, while the remaining five ankles were prepared using dual mini incisions. After the completion of preparation, all ankles were dissected to open, photographic images of tibial plafond and talar articular were taken. Surface areas of each articular facet and unprepared cartilage of the talus, distal tibia, and distal fibula were measured and analyzed using ImageJ software.Results:Significantly greater amount of total surface area was prepared among specimens using mini-open approach compared to those with trans-fibular approach. The percentage of total articulating surface area prepared (including talus and tibia/fibula), talus, tibia and fibula in trans-fibular approach were 76.9%, 77.7% and 75% respectively. The percentages were 90.9%, 92.9%, and 88.6% in mini-open approach.While the medial gutter was well prepared with mini incision technique (unprepared surface 44 .64% vs 91.08%), lateral gutter was well prepared in trans-fibular technique (88.82vs 82.04 square cm).There is no difference in the amount of unprepared surface of talar dome between the two approaches. When excluding the medial gutter, there was no significant difference between trans-fibular and mini open techniques (83.94 vs 90.85, p=0.1412).Conclusion:Joint preparation using the mini-open approach (extended arthroscopic portal) is equally as efficacious as the transfibular approach for preparation of the tibiotalar joint. When including preparation of the medial gutter, the mini-open approach provides superior joint preparation. This may be advantageous with decreased rate of nonunion and less complications. But many surgeons fuse only tibiotalar surface, considering that, both approaches yield equal amount of joint preparation. But it needs to be confirmed with clinical studies.

Total ankle arthroplasty and ankle arthrodesis affect the biomechanics of the inner foot differently

Ankle arthrodesis and total ankle arthroplasty are the two primary surgeries for treatment of end-stage degenerative ankle arthritis. The biomechanical effects of them on the inner foot are insufficient to identify which is superior. This study compared biomechanical parameters among a foot treated by ankle arthrodesis, a foot treated by total ankle arthroplasty, and an intact foot using computational analysis. Validated finite element models of the three feet were developed and used to simulate the stance phase of gait. The results showed total ankle arthroplasty provides a more stable plantar pressure distribution than ankle arthrodesis. The highest contact pressure, 3.17 MPa, occurred in the medial cuneonavicular joint in the total ankle arthroplasty foot. Neither of the surgeries resulted in contact pressure increase in the subtalar joint. The peak stress in the metatarsal bones was increased in both surgical models, especially the second and third metatarsals. This study enables us to get visual to the biomechanics inside of an intact foot, and feet treated by total ankle arthroplasty and ankle arthrodesis during walking.

Considerations in the Surgical Management of End-Stage Ankle Arthritis: Commentary on an article by Andrea N. Veljkovic, BComm, MPH, MD, FRCSC, et al.: "Outcomes of Total Ankle Replacement, Arthroscopic Ankle Arthrodesis, and Open Ankle Arthrodesis for Isolated Non-Deformed End-Stage Ankle Arthritis".

Considerations in the Surgical Management of End-Stage Ankle Arthritis: Commentary on an article by Andrea N. Veljkovic, BComm, MPH, MD, FRCSC, et al.: "Outcomes of Total Ankle Replacement, Arthroscopic Ankle Arthrodesis, and Open Ankle Arthrodesis for Isolated Non-Deformed End-Stage Ankle Arthritis".

Role of Postoperative Patient-Reported Outcomes to Predict Ankle Arthroplasty and Arthrodesis Revision.

Patient-reported outcomes are becoming common for measuring patient-centric outcomes in surgery. However, there is little known about the relationship between postoperatively collected patient-reported outcomes and objective clinical outcomes. The objective of this study was to measure whether postoperative Ankle Osteoarthritis Scale (AOS) values were associated with risk of revision among patients having ankle arthrodesis or total ankle arthroplasty for treatment of symptomatic end-stage ankle arthritis. This is a retrospective analysis of a longitudinal cohort of ankle arthrodesis and total ankle arthroplasty patients. A single center recruited patients between 2003 and 2013 and follow-up was at least 4 years. Patients completed the AOS preoperatively and annually following surgery. An extended Cox regression model incorporating time-varying AOS values was used to model risk of failure. A total of 336 patients and 348 ankles were included, representing 139 ankle arthrodesis procedures and 209 total ankle arthroplasties. The median follow-up time for revisions was 8.2 years and 46 patients had a revision. Higher values of patients' AOS scores in the postoperative period were associated with a higher likelihood of revision (hazard ratio, 1.04 per 1-point increase; 95% confidence interval, 1.03-1.05). Ankle arthrodesis was associated with a reduced risk of revision compared with ankle fusion (hazard ratio, 0.12; 95% confidence interval, 0.03-0.49). This study showed that persistent pain and poor function after fusion or replacement surgery, as measured by elevated values of the AOS, were associated with higher risk of further surgery. Level III, retrospective cohort study.

Role of Rotation in Total Ankle Replacement.

The importance of total ankle replacement (TAR) implant orientation in the axial plane is poorly understood with major variation in surgical technique of implants on the market. Our aim was to better understand the axial rotational profile of patients undergoing TAR. In 157 standardized computed tomography (CT) scans of patients with end-stage ankle arthritis planning to undergo primary TAR surgery, we measured the relationship between the knee posterior condylar axis, the tibial tuberosity, the transmalleolar axis (TMA), and the tibiotalar angle. The foot position was measured in relation to the TMA with the foot plantigrade. The variation between the medial gutter line and the line bisecting both gutters was assessed. The mean external tibial torsion was 34.5 ± 10.3 degrees (11.8-62 degrees). When plantigrade, the mean foot position relative to the TMA was 21 ± 10.6 degrees (0.7-38.4 degrees) internally rotated. As external tibial torsion increased, the foot position became more internally rotated relative to the TMA (Pearson correlation, 0.6; P < .0001). As the tibiotalar angle became more valgus, the foot became more externally rotated relative to the TMA (Pearson correlation, -0.4; P < .01). The mean difference between the medial gutter line and a line bisecting both gutters was 4.9 ± 2.8 degrees (1.7-9.4 degrees). More than 51% of patients had a difference greater than 5 degrees. The mean angle between the medial gutter line and a line perpendicular to the TMA was 7.5 ± 2.6 degrees (2.8-13.7 degrees). There was a large variation in rotational profile of patients undergoing TAR, particularly between the medial gutter line and the TMA. Surgeon designers and implant manufacturers should develop consistent methods to guide surgeons toward judging the appropriate axial rotation of their implant on an individual basis. We recommend careful clinical assessment and preoperative CT scans to enable the correct rotation to be determined. Level IIc, outcomes research.

Outcome after total ankle arthroplasty with a minimum of five years follow-up: A systematic review and meta-analysis

BackgroundTotal ankle arthroplasty (TAA) is increasingly gaining recognition as an alternative to ankle arthrodesis in the treatment of end-stage ankle arthritis. Despite high rates of adverse events during early inception, newer generations of uncemented prosthesis and design modifications have improved outcomes. Questions remain regarding the long-term outcomes and implant survivorship of TAA. AimThis analysis aims to establish an updated review of intermediate and long-term clinical outcome and complication profile of TAA. Patients and methodsA multi database search was performed on 14th October 2018 according to PRISMA guidelines. All articles that involved patients undergoing uncemented TAA with 5 years minimum follow-up, reported clinical outcome or complication profile of TAA were included. Seventeen observational studies were included in the review, with 1127 and 262 ankles in the 5 and 10 years minimum follow-up groups respectively. ResultsMean difference between pre- and post-operative AOFAS score was 43.60 (95%CI: 37.51–49.69, p<0.001) at 5 years minimum follow-up. At 5 years minimum follow-up, pooled proportion (PP) of prostheses revision for any reason other than polyethylene exchange was 0.122 (95%CI: 0.084–0.173), all cause revision was 0.185 (95%CI: 0.131–0.256), unplanned reoperation was 0.288 (95%CI: 0.204–0.390) and all infection was 0.033 (95%CI: 0.021–0.051). At 10 years minimum follow-up, PP of prostheses revision for any reason other than polyethylene exchange was 0.202 (95%CI: 0.118–0.325), all cause revision was 0.305 (95%CI: 0.191–0.448), unplanned reoperation was 0.422 (95%CI: 0.260–0.603) and all infection was 0.029 (95%CI: 0.013–0.066). ConclusionDespite good intermediate and long-term functional outcome measures, TAA has relatively higher revision surgery prevalence with longer follow-up periods. Further research should be directed towards identifying patient populations that would best benefit from TAA and those at greatest risk of requiring revision surgery.

Ankle Arthritis.

Ankle arthritis is a major source of morbidity impacting a younger working age population than hip and knee arthritis. Unlike the hip and knee, more than 70% of ankle arthritis cases are post-traumatic, with the remainder being inflammatory or primary arthritis. Nonoperative treatment begins with lifestyle and shoe-wear modifications and progresses to bracing, physical therapy, anti-inflammatory medications, and intra-articular injections. Ankle arthrodesis and total ankle arthroplasty are the 2 main surgical options for end-stage ankle arthritis, with debridement, realignment osteotomy, and distraction arthroplasty being appropriate for limited indications.Level of Evidence:Level V, expert opinion.

Total Ankle Arthroplasty Survival and Risk Factors for Failure.

Total ankle arthroplasty (TAA) is an increasingly selected treatment for end-stage ankle arthritis; however, failure and revision of the tibial and talar components remains an issue. Although multiple risk factors have been shown to contribute to early component revision, no study has looked at combining such risk factors into a predictive model that could potentially decrease revision rates and improve implant survival. This study aimed to develop a predictive model for TAA failure based on patient characteristics, patient-reported outcomes (PROs), and immediate postoperative radiographs. A retrospective review of a single-site ankle arthritis database was conducted. All patients with current-generation ankle replacements including the Hintegra and Infinity prostheses implanted between 2004 and 2015 and with complete postoperative radiographs taken between 6 and 12 weeks postoperatively were included. Eight coronal and sagittal radiographic parameters were assessed and performed twice by 2 independent orthopedic surgeons on included TAAs. These radiographic parameters were then analyzed in association with patient demographics and PRO. Advanced statistical methods including survival analysis were used to construct a predictive model for TAA survival. A total of 107 patients were included and analyzed with a median clinical follow-up of 49 months (minimum 24 months). A predictive model was created, with 4 parameters identified as being statistically associated with TAA metal-component revision: diabetes mellitus, poor baseline Ankle Osteoarthritis Scale (AOS) score, excessively dorsiflexed talar component, and an anteriorly/posteriorly translated talus relative to the tibial axis. The presence of 3 parameters predicted TAA survival of 0.60 whereas presence of all 4 parameters predicted survival of only 0.13 in the period studied. Our predictive model is based on a combination of patient factors, PROs, and radiographic TAA alignment. We believe it can be used by surgeons to predict failure in their TAA patients, thereby optimizing postoperative outcomes by improving patient selection and modifiable outcome-specific parameters. Level III, retrospective cohort study using prospectively collected data.

Bipolar Fresh Osteochondral Allograft Transplantation of the Tibiotalar Joint: A Concise Mid-Term Follow-up of a Previous Report★.

Despite advances in managing degenerative arthritis of the ankle joint, there are few optimal treatment options for young patients with symptomatic, end-stage degenerative disease. Popular surgical options consist of traditional arthrodesis and, more recently, arthroplasty. Additional techniques, including arthroscopic debridement and joint distraction, have gained little traction. An alternative option is bipolar fresh osteochondral allograft (OCA) transplantation of the tibiotalar joint. We previously reported on a cohort of 86 ankles that had undergone bipolar OCA of the tibiotalar joint and now present the results after longer, mid-term follow-up (mean, 9.2 years) of the same cohort. OCA survivorship was 74.8% at 5 years and 56% at 10 years. Of the patients with a surviving graft, 74% were satisfied with the results. At the latest follow-up, 86% reported better function and 79% reported less pain compared with preoperatively. Bipolar OCA transplantation of the tibiotalar joint is an effective alternative treatment for selected young patients with end-stage ankle arthritis who wish to avoid arthrodesis or prosthetic arthroplasty. LEVEL OF EVIDENCE:: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

The Effect of Sagittal and Coronal Balance on Patient-Reported Outcomes Following Mobile-Bearing Total Ankle Replacement

Total ankle replacement (TAR) is an established technique for the treatment of end-stage ankle arthritis. The aims of TAR include pain relief, preservation of tibiotalar movement, protection of adjacent joints, and restoration of anatomic alignment in the coronal and sagittal planes. The aims of this study were to determine the relative importance of pre- and post-TAR coronal and sagittal balance on postoperative patient-reported outcome measures (PROMs). A total of 101 ankles in 99 patients were included in this retrospective cohort study. Patients were scored preoperatively and at a minimum of 2 years by using the Foot and Ankle Outcome Score (FAOS), the American Orthopedic Foot and Ankle Society (AOFAS) hindfoot-ankle score, the Short Form-36 measures, and a set of radiographic measurements to define the sagittal and coronal alignment. There was no significant difference between the groups regarding the anterior or posterior translation of the talus preoperatively. There were no statistically significant correlations between any preoperative measure and any domain of the PROM data. Significant correlations were observed between postoperative medial distal tibial angle and the function domain of the FAOS and the AOFAS hindfoot-ankle score. Preoperative coronal and sagittal plane deformity are not markedly different, depending on the diagnosis. Preoperative deformity does not appear to correlate significantly with postoperative function, as measured by the PROM scores. Postoperative sagittal plane alignment does not correlate significantly with postoperative function, as measured by PROMs. Coronal plane alignment, as measured by the medial distal tibial angle, may be associated with postoperative function, as measured on the AOFAS hindfoot-ankle and FAOS function subscales.

Do preoperative patient-reported outcomes predict hospital length of stay for surgically-treated end-stage ankle osteoarthritis patients?

BackgroundEnd-stage ankle arthritis is often debilitating, associated with diminished mobility, pain, and reduced health related quality of life. Direct hospital costs of AA and TAA differ, with hospital length of stay being a major contributor. The objective of this study is to test the association between four patient-reported outcome measures with hospital length of stay, potentially important for preoperative planning and care. MethodsThis study is based on a prospective cohort of patients scheduled for AA or TAA for end-stage ankle arthritis in the Vancouver Coastal Health authority, Canada. Participants completed a condition-specific instrument, the AOS, and three generic instruments, the PHQ-9, PEG and EQ-5D(3L) shortly after being scheduled for surgery. Multivariate mixed-effects Poisson regression models were used to measure the association between preoperative patient-reported outcome measures and length of stay. ResultsAmong the 183 patients eligible to participate, the participation rate was 48.5%. There were 89 participants. Participants reported a high level of preoperative ankle impairment and pain. The adjusted results found no relationship between the AOS, EQ-5D(3L) VAS or PHQ-9 values and participants’ LOS. Participants with at least one chronic health condition and lowest SES category had longer LOS. ConclusionsThis study found no evidence of an association between four PROs collected prior to AA or TAA with hospital LOS. This finding suggests collecting these PROs preoperatively may not help with discharge planning.

Surgeon Type and Outcomes After Inpatient Ankle Arthrodesis and Total Ankle Arthroplasty: A Retrospective Cohort Study Using the Nationwide Premier Healthcare Claims Database.

Two main treatments for end-stage ankle arthritis are ankle arthrodesis and total ankle arthroplasty (TAA). While both procedures can be performed either by a foot and ankle orthopaedic surgeon or a podiatrist (when within a particular state's scope of practice), studies comparing the surgical outcomes of the 2 surgeon types are lacking. Therefore, in this study, we compared outcomes by surgeon type for TAA and for ankle arthrodesis. This retrospective cohort study utilized data from the nationwide Premier Healthcare claims database (2011 to 2016) regarding TAA (n = 3,674) and ankle arthrodesis (n = 4,980) procedures. Multivariable models estimated associations between surgeon type (podiatrist versus orthopaedic foot and ankle surgeon) and opioid utilization (in oral morphine equivalents [OMEs]), length of stay, and cost of hospitalization. We report percent change (compared with reference) and 95% confidence intervals (CIs). Overall, 76.5% (n = 2,812) and 18.8% (n = 690) of TAA procedures were performed by orthopaedic foot and ankle surgeons and podiatrists, respectively; surgeon type was unknown for 4.7% (n = 172). For ankle arthrodesis, 75.3% (n = 3,752) and 18.3% (n = 912) of the procedures were performed by orthopaedic foot and ankle surgeons and podiatrists, respectively; surgeon type was unknown for 6.3% (n = 316). The proportion of TAA and ankle arthrodesis procedures performed by podiatrists increased over time, from 12.8% and 13.6% in 2011 to 24.6% and 26.0% in 2016, respectively. When adjusting for relevant covariates, procedures performed by podiatrists (compared with orthopaedic foot and ankle surgeons) were associated with increased length of stay: for TAA, +16.7% (95% CI, 7.6% to 26.5%; median, 2 days in both groups) and for ankle arthrodesis, +14.2% (95% CI, 7.9% to 20.9%; median, 3 compared with 2 days) (p < 0.05 for both). In addition, ankle arthrodesis performed by podiatrists was associated with increased cost of hospitalization: +28.5% (95% CI, 22.1% to 35.2%; median, $19,236 compared with $13,433) (p < 0.05). Differences in opioid utilization were nonsignificant in the main analysis: +10.9% (95% CI, -3.1% to 26.8%; median, 345 compared with 250 OMEs) and +2.8% (95% CI, -5.9% to 12.4%; median, 351 compared with 315 OMEs) for TAA and ankle arthrodesis, respectively. An increasing trend in the proportion of procedures performed by podiatrists was coupled with apparent increases in length of stay and cost compared with procedures performed by orthopaedic foot and ankle surgeons. Given the increasing demand for these procedures, factors associated with resource utilization, such as type of surgeon, may be increasingly important on the population level. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Validation of the Ankle Osteoarthritis Scale Instrument for Preoperative Evaluation of End-Stage Ankle Arthritis Patients Using Item Response Theory

Significant ankle arthritis results in functional limitations and patient morbidity. There is a need to measure symptoms and the impact of interventions on patient's quality of life using valid and reliable patient-reported measurement instruments. The objective of this research was to validate the Ankle Osteoarthritis Scale instrument in the preoperative setting using factor analysis, item response theory, and differential item function methods. This research is based on secondary analysis of patients scheduled for ankle arthrodesis or total ankle replacement in Vancouver, Canada. Participants completed the instrument between September 2014 and August 2017. Item response theory was used to estimate item difficulty and discrimination parameters, controlling for study participants' underlying level of ankle function. Differential item function was examined for sex, age group, and surgery. There were 88 participants. Modification indices suggested that item 10, "walking around the house," would better fit the pain domain rather than the disability domain. Items in the pain domain displayed a range of discrimination and difficulty. Items in the disability domain exhibited a range of discrimination, though the disability domain had low difficulty. Differential item functioning for sex, age group, and ankle arthrodesis or total ankle replacement appeared to be ignorable. This evaluation of the Ankle Osteoarthritis Scale found the instrument to be a strong measure of the effect of pain and dysfunction among patients with end-stage ankle arthritis, even when removing items 7 and 8, supporting its prior use in numerous clinical studies. Level II, prospective comparative study.

A Critical Radiographic Analysis of Coronal Plane Deformity Correction Using a 3-Piece Mobile Bearing Ankle Joint Replacement: A Retrospective Study of 25 Patients

Total ankle replacement can be a viable option for patients with end-stage ankle arthritis associated with coronal plane deformity. With proper ankle balancing, a well-aligned ankle implant can be maintained over time and provide successful patient outcomes. The purpose of this study was to evaluate radiographic and subjective outcomes in patients with ankle arthritis along with coronal plane deformity who underwent total ankle arthroplasty with a 3-piece mobile-bearing implant. Our primary inclusion criterion was patients who demonstrated more than 5° of tibiotalar coronal deformity in either varus or valgus direction. Sixty-three consecutive patients who underwent total ankle replacement were reviewed. Of these, 25 (39.7%) met the inclusion criteria. Sixteen (64%) patients had a varus deformity (Group 1) and 9 (36%) had valgus deformity (Group 2) preoperatively. Alignment was evaluated radiographically at 5 different intervals: preoperative, immediate postoperative, and 6, 12, and 36 months postoperative. In patients with varus deformity, the mean tibiotalar angle was 12.6°, 0.8°, 1.0°,1.0°, and 0.8° for preoperative, immediate postoperative, and 6, 12, and 36 months, respectively. The same measurements and intervals for patients with valgus deformity were found to be 10.3°, 1.4°, 1.6°, 1.4°, and 1.4°. A statistically significant difference was observed in preoperative and postoperative coronal plane deformity. This correction was maintained at final follow-up visit. American Orthopaedic Foot and Ankle Society scores and visual analogue scale scores were recorded as well, and statistically significant improvements in preoperative and postoperative scores were found (p < .001). In conclusion, coronal plane deformity correction of the ankle can be accomplished and maintained in total ankle replacement procedures with proper soft tissue balancing and osseous procedures as indicated.

Initial stability and stress distribution of ankle arthroscopic arthrodesis with three kinds of 2-screw configuration fixation: a finite element analysis

BackgroundArthroscopic ankle arthrodesis (AAA) is recognized as the standard treatment for the end-stage ankle arthritis. Two-screw configuration fixation is a typical technique for AAA; however, no consensus has been reached on how to select most suitable inserted position and direction. For better joint reduction, we developed a new configuration (2 home run-screw configuration: 2 screws are inserted from the lateral-posterior and medial-posterior malleolus into the talar neck) and investigated whether it turned out to be better than the other commonly used 2-screw configurations.MethodsIn this study, we investigated three kinds of 2-screw configurations: 2 “home run”-screw configuration (group A), crossed transverse configuration (the screw is inserted from the medial malleolus into the anterior talus and the other from the lateral tibia maintains posterior talus, group B), and 2 parallel screw configuration (2 parallel screws are inserted from the posteromedial side of the tibia into talus, group C). The effects of the above three insertions on the loading stress of the tibio-talar joint were comparatively analyzed with a three-dimensional finite element model.ResultsGroup A was better than groups B and C in respect of stress distribution uniformity and superior to both groups B and C in anti-flexion strength and anti-internal rotation strength. Group A was slightly worse than group C but better than group B in anti-dorsiflexion and anti-valgus and varus strength.ConclusionsTwo “home run”-screw configuration facilitates the reduction of anterior talus dislocation of end-stage ankle arthritis. Our finite element analysis demonstrates the configuration is superior to crossed transverse and parallel configuration for arthroscopic ankle arthrodesis in terms of stress distribution and initial stability.

Total ankle replacement: is pre-operative varus deformity a predictor of poor survival rate and clinical and radiological outcomes?

The objective of this study was to compare survival rate and clinical and radiological outcomes of a cementless mobile-bearing total ankle replacement (TAR) between two groups of patients, affected by end-stage ankle arthritis, with or without a pre-operative varus deformity. A total of 81 patients (81 ankles) were included in the study and divided in two groups. Group A, "varus" group, includes 11 patients with pre-operative varus deformity of more than 10° and group B, "neutral" group, includes 70 patients, with a varus/valgus deformity of less than 10°. American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, visual analogue scale (VAS), and Short Form (SF)-12 score were used to compare clinical outcomes. Radiological parameters, complications, and survival rate at last follow-up were also recorded. In both groups, all clinical and radiological parameters improved after surgery (p< 0.05) without statistically significant difference. Complications were similar between two groups. Overall in three cases, an implant revision was necessary: 1 in group A (9%) at 3.1years follow-up and 2 (3%) in group B at 3.8years, without statistically significant difference (p> 0.001). Severe varus malalignment should not be considered a contraindication for a mobile-bearing TAR. Nevertheless, TAR in severe deformity should be performed only by experienced surgeons.

Outcome after 52 Salto Ankle Prostheses Implanted by a Single Surgeon.

While ankle arthrodesis was traditionally the gold standard method of treatment for disabling end-stage ankle arthritis, total ankle replacement (TAR) has been an acceptable alternative. The satisfaction rate of patients with TAR however differs. The purpose of our study is to investigate whether implant survival and results with special emphasis on the satisfaction rate of patients treated with a TAR implanted by a single surgeon were comparable to the literature. This was a retrospective cohort study in a teaching hospital. Data was collected from 52 patients who received a total ankle replacement (TAR) between 05/2002 and 06/2014. The mean follow-up time was 4.2 years (95% CI 3.3 – 5.0). Results showed a high satisfaction rate of 94% and 94% survival of the TAR after 5 years. We conclude that TAR with the Salto prosthesis is, in our hands, a reliable solution for end-stage ankle arthritis, with results comparable to the literature.