Ankle arthritis

Comparative finite element analysis of contact and stress distribution in tibiotalar articular cartilage: Healthy versus varus ankles

Background

The distribution of forces within the ankle joint plays a crucial role in joint health and longevity. Loading disorders affecting the ankle joint can have significant detrimental effects on daily life and activity levels. This study aimed to enhance our understanding of the mechanical behavior of tibiotalar joint articular cartilages in the presence of varus deformity using finite element analysis (FEA) applied to patient-specific models.

Methods

Two personalized ankle models, one healthy and another with varus deformity, were created based on CT scan images. Four static loading scenarios were simulated at the center of pressure (COP), coupled to the hindfoot complex. The contact area, contact pressure, and von Mises stress were computed for each cartilage.

Results

It was found that the peak contact pressure increased by 54% in the ankle with varus deformity compared to the healthy ankle model. Furthermore, stress concentrations moving medially were observed, particularly beneath the medial malleolus, with an average peak contact pressure of 3.5 MPa and 4.7 MPa at the tibial and talar articular cartilages, respectively.

Conclusion

Varus deformities in the ankle region have been consistently linked to elevated contact pressure, increasing the risk of thinning, degeneration, and eventual onset of osteoarthritis (OA), emphasizing the need for prompt interventions aimed at mitigating complications.

Patient-specific modelling of contact characteristics in the ankle joint following triple arthrodesis in valgus, neutral and varus hindfoot positions

The aim of the current study was to understand the importance of the joint alignment following triple arthrodesis by analysing the contact characteristics in a normal and arthritic ankle joint using a patient-specific numerical model developed using open source software. The alignment of the hindfoot with respect to tibia is calculated from CT scans and the ankle joint model was numerically analysed for neutral, valgus and varus positions in both normal and arthritic conditions. The contact area, the magnitude and distribution of the contact pressure on the articular surface of the talar dome was evaluated using a cell-centred Finite Volume Method implemented in open-source software OpenFOAM. It was found that all positions of the hindfoot predict higher lateral pressures during heel strike. The varus position predicts the maximum increase in lateral pressures. Comparing the valgus and neutral positions, although the neutral position predicts 9.1 % higher increase in lateral pressures during heel strike than valgus, it predicts 33.6 % decrease in pressures during heel-rise and the distribution is more medial during toe-off. In the case of arthritic ankle, it could be observed that the neutral and varus hindfoot fusion positions result in a concentrated increase of lateral pressures in heel strike and flat-foot. In the case of toe-off, the neutral alignment results in an increase of 62.3 % in the contact pressures compared to the arthritic pressure of the unfused foot and is 20.8 % higher than the valgus alignment. The study helps to conclude that the fusion is more beneficial at the neutral position of the hindfoot for the patient specific ankle. However, the 5° valgus position of hindfoot alignment could be more beneficial in the arthritic ankle. Patient-specific approach to the placement of the hindfoot with the help of numerical analysis could help address the issue of ankle degradation following arthrodesis.

Association of Timing of Hindfoot Arthrodesis and Early Reoperation Rates for Total Ankle Arthroplasty

BACKGROUND

Prior literature has demonstrated that ipsilateral hindfoot arthrodesis may increase the risk for reoperation after total ankle arthroplasty (TAA) and that simultaneous hindfoot arthrodesis with TAA could result in short-term clinical and radiologic improvements. The purpose of this study is to compare the reoperation rates after TAA with prior hindfoot arthrodesis vs simultaneous arthrodesis and TAA.

METHODS

Patients who underwent primary TAA were identified in the PearlDiver database. Patients were sorted into 2 study cohorts: hindfoot arthrodesis prior to TAA and simultaneous arthrodesis and TAA. Propensity matched control cohorts were identified for each study group. Multivariate analysis was conducted to account for any confounding variables and covariates when identifying differences in complications between cohorts.

RESULTS

297 patients underwent TAA with prior hindfoot arthrodesis and 174 underwent TAA and hindfoot arthrodesis concurrently. The incidence of reoperation (13.8% vs 5.2%, P < .001) and infection (12.6% vs 5.9%, P = .011) for the simultaneous cohort was higher when compared to the matched control cohort. In contrast, there was no statistically significant difference when comparing the prior arthrodesis cohort to the matched control cohort in reoperation rates (5.1% vs 4.7%, P = .787) or infection rates (4.4% vs 4.8%, P = .734). Those undergoing simultaneous procedures had increased incidences of reoperation, wound complications, infection, and emergency department visits (P < .0167) when compared to the TAA with prior arthrodesis cohort.

CONCLUSION

Patients undergoing TAA and hindfoot arthrodesis concurrently were found to have higher rates of reoperation and infection when compared to the matched control cohort . In contrast, there was no difference in these rates in patients undergoing TAA with prior hindfoot arthrodesis compared with their matched control cohort. Patients undergoing simultaneous procedures had increased rates of reoperations, wound complications, infection, and emergency department visits compared to the TAA with prior arthrodesis cohort.

Ankle Osteoarthritis

Ankle osteoarthritis (OA) is less common than knee and hip OA, and 75% to 80% of all presentations are posttraumatic in nature, resulting from either ligamentous or bony injury to the ankle. While the ankle joint cartilage demonstrates capacity for self-restoration, the ankle joint is sensitive to aberrancies in biomechanics and the inflammatory milieu after an injury is thought to contribute to the onset of posttraumatic ankle OA. Conservative care for ankle OA is currently centered on pain reduction, and derivatives that may delay the progression of ankle OA are the subject of ongoing investigation. Surgical management for end-stage ankle OA currently focuses on ankle arthrodesis and total ankle arthroplasty. Specific indication for one procedure over the other is the topic of much debate. While total ankle arthroplasty has become more frequently used with the advent of newer generation systems, ankle arthrodesis may still be favored in younger patients with high-demand occupations.

Body Mass Index, Sex, and Age Are Predictors of Discharge to a Post-acute Care Facility Following Total Ankle Arthroplasty

BACKGROUND

The utilization of total ankle arthroplasty (TAA) continues to increase. Discharge to a post-acute care (PAC) facility can increase patient morbidity and postoperative costs. The purpose of this study is to investigate the effects of age and body mass index (BMI) on discharge to a PAC facility and hospital length of stay (LOS) following TAA.

METHODS

A retrospective review of patients who underwent TAA from the National Surgical Quality Improvement Program (NSQIP) database was performed. Using overweight patients as the reference BMI group, sex- and age-adjusted log-binomial regression models were utilized to estimate risk ratios of BMI categories for being discharged to a PAC facility. A linear regression was utilized to estimate the effect of BMI category on hospital LOS.

RESULTS

Obese patients had 1.36 times the risk of overweight patients (P = .040), and morbidly obese patients had 2 times risk of overweight patients (P = .001) of being discharged to a PAC facility after TAA. Men had 0.48 times the risk of women (P < .001). Compared with patients aged 18 to 44 years, patients aged ≥65 years had 4.13 times the risk (P = .012) of being discharged to a PAC facility after TAA. Relative to overweight patients, on average there was no difference in hospital LOS for underweight patients, but healthy weight patients stayed an additional 0.30 days (P=.003), obese patients stayed an additional 0.18 days (P = .011), and morbidly obese patients stayed an additional 0.33 days (P = .009). Men stayed 0.29 fewer hospital days than women (P < .001) on average.

CONCLUSION

Women and patients who are obese or morbidly obese have a longer hospital LOS and an increased chance of being discharged to a PAC facility. Increasing age is also associated with an increased risk of being discharged to a PAC. These may be important factors when developing and discussing the postoperative plan with patients prior to TAA.

LEVELS OF EVIDENCE

Level III.

The Relationship Between Calcaneofibular Ligament Injury and Ankle Osteoarthritis Progression: A Comprehensive Analysis of Stress Distribution and Osteophyte Formation in the Subtalar Joint

BACKGROUND

Ankle osteoarthritis (OA) mainly arises from trauma, particularly lateral ligament injuries. Among lateral ligament injuries, ankles with calcaneofibular ligament (CFL) injuries exhibit increased instability and can be a risk factor ankle OA progression. However, the relationship between CFL injury and OA progression remains unclear. Therefore, this study aims to assess the relationship between CFL injuries and ankle OA by investigating stress changes and osteophyte formation in subtalar joint.

METHODS

We retrospectively reviewed the magnetic resonance imaging (MRI) and plain radiographic evaluations of 100 ankles of 91 patients presenting with chronic ankle instability (CAI), ankle OA, or other ankle conditions. The association between CFL injuries on the oblique view of MRI and the severity of ankle OA (based on Takakura-Tanaka classification) was statistically evaluated. Additionally, 71 ankles were further subjected to CT evaluation to determine the association between the CFL injuries and the Hounsfield unit (HU) ratios of the subtalar joint and medial gutter, and the correlation between the subtalar HU ratios and osteophyte severity were statistically evaluated.

RESULTS

CFL injury was observed in 35.9% (14/39) of patients with stage 0, 42.9% (9/21) with stage 1, 50.0% (10/20) with stage 2, 100% (9/9) with stage 3a, and 90.9% (10/11) with stage 3b. CFL-injured ankles exhibited higher HU ratios in the medial gutter and lower ratios in the medial posterior subtalar joint compared to uninjured ankles. A negative correlation was observed between medial osteophyte severity and the medial subtalar joint HU ratio.

CONCLUSION

Our findings suggest that CFL injuries are common in severe ankle OA impairing the compensatory function of the subtalar joint through abnormal stress distribution and osteophyte formation.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Effect of novel polyethylene insert configurations on bone-implant micromotion and contact stresses in total ankle replacement prostheses: a finite element analysis

Purpose

This study investigates the impact of elastic improvements to the artificial ankle joint insert on prosthesis biomechanics to reduce the risk of prosthesis loosening in TAR patients.

Methods

CT data of the right ankle was collected from one elderly female volunteer. An original TAR model (Model A) was developed from CT images and the INBONE II implant system. The development of the new inserts adopts an elastic improvement design approach, where different geometric configurations of flexible layers are inserted into the traditional insert. The structure can be divided into continuous flexible layers and intermittent flexible layers. The flexible layers aim to improve the elasticity of the component by absorbing and dispersing more kinetic energy. The newly designed inserts are used to replace the original insert in Model A, resulting in the development of Models B-D. A finite element model of gait analysis was based by gait parameters. Discrepancies in micromotion and contact behaviour were analysed during the gait cycle, along with interface fretting and articular surface stress at 50% of the gait cycle.

Results

In terms of micromotion, the improved elastic models showed reduced micromotion at the tibial-implant interfaces compared to the original model. The peak average micromotion decreased by 12.1%, 13.1%, and 14.5% in Models B, C, and D, respectively. The micromotion distribution also improved in the improved models, especially in Model D. Regarding contact areas, all models showed increased contact areas of articular surfaces with axial load, with Models B, C, and D increasing by 26.8%, 23.9%, and 24.4%, respectively. Contact stress on articular surfaces increased with axial load, reaching peak stress during the late stance phase. Models with continuous flexible layer designs exhibited lower stress levels. The insert and the talar prosthetic articular surfaces showed more uniform stress distribution in the improved models.

Conclusion

Improving the elasticity of the insert can enhance component flexibility, absorb impact forces, reduce micromotion, and improve contact behavior. The design scheme of continuous flexible layers is more advantageous in transmitting and dispersing stress, providing reference value for insert improvement.

Quality of Outcomes Research in Total Ankle Arthroplasty

Total ankle arthroplasty is a topic that has recently gained increasing interest, largely due to the improved outcomes, which have been demonstrated by short- and mid-term research studies on the newer, third-generation implant designs. The purpose of this review is to provide an updated assessment of the quality of outcomes research on total ankle arthroplasty.

Morphological features of the non-affected side of the hindfoot in patients with unilateral varus ankle osteoarthritis

BACKGROUND

The innate shape characteristics of the hindfoot bones alter the loading conditions of the foot and thus may be associated with an increased risk of developing varus ankle osteoarthritis (OA). This study aimed to clarify the innate morphological patterns of the hindfoot bones that may be associated with ankle OA by analyzing the differences between the bone morphology of the non-affected side of patients with unilateral varus ankle OA and that of healthy participants.

METHODS

In this case-control study, computed tomography images were used to develop three-dimensional models of three hindfoot bones (distal tibia with fibula, talus, and calcaneus) from 23 non-affected sides of patients with radiography-diagnosed unilateral ankle OA and 22 healthy control participants. Anatomical and sliding landmarks were placed on the surface of each bone, and the principal components (PCs) of shape variation among specimens were independently calculated for each bone, preserving homology between individuals. The PC modes representing 5% or more of the overall variation were statistically compared between the ankle OA and control groups.

RESULTS

Significant differences were identified between the OA and control groups in the fifth PC mode for the tibia with fibula (proportion of variance, 5.1%; p =.025), fifth PC mode for the talus (6.7%, p =.031), and third PC mode for the calcaneus (7.4%, p =.001). The hindfoot bones of the participants who developed ankle OA had the following innate morphological characteristics: the lateral malleolar articular surface of the fibula was shifted superiorly, tibial plafond was enlarged posteroinferiorly, posterior width of the talar trochlea was narrower, talonavicular articular surface of the talus was oriented more frontally, anterior-middle talocalcaneal articular surfaces of the talus were more medially shifted and those of the calcaneus were flatter, calcaneal sustentaculum tali was less protruding, and lateral plantar process of the calcaneus was more superiorly positioned.

CONCLUSIONS

These distinctive morphological alterations may increase the incidence and progression of varus ankle OA through aberrant anterior translation, internal rotation, and varus tilting of the talus.

The Role of Supramalleolar Osteotomies in Ankle Arthritis

The supramalleolar osteotomy (SMO) is a joint-preserving surgical procedure that allows realignment of the ankle joint in severe deformity secondary to arthritis. This osteotomy realigns the mechanical axis to provide better weight distribution through the ankle joint. With an aligned mechanical axis, the overloaded asymmetric ankle joint will shift toward the preserved joint area in a valgus or varus ankle joint. The SMO also can be used via a staged approach to correct severe deformity in an end-stage arthritic ankle before total ankle arthroplasty to optimize the implant's longevity and improve overall functional outcomes.

Assessment of articular cartilage of ankle joint in stable and unstable unilateral weber type-B/SER-type ankle fractures shortly after trauma using T2 relaxation time

Background

Early detection of post-traumatic cartilage damage in the ankle joint in magnetic resonance images can be difficult due to disturbances to structures usually appearing over time.

Purpose

To study the articular cartilage of unilateral Weber type-B/SER-type ankle fractures shortly post-trauma using T2 relaxation time.

Material and Methods

Fifty one fractured ankles were gathered from consecutively screened patients, compiled initially for RCT studies, and treated at Oulu University Hospital and classified as stable (n = 28) and unstable fractures (n = 23) based on external-rotation stress test: medial clear space of ≥5 mm was interpreted as unstable. A control group of healthy young individuals (n = 19) was also gathered. All ankles were imaged on average 9 (range: 1 to 25) days after injury on a 3.0T MRI unit for T2 relaxation time assessment, and the cartilage was divided into sub-regions for comparison.

Results

Control group displayed significantly higher T2 values in tibial cartilage compared to stable (six out of nine regions, p-values = .003-.043) and unstable (six out of nine regions, p-values = .001-.037) ankle fractures. No differences were detected in talar cartilage. Also, no differences were observed between stable and unstable fractures in tibial or talar cartilage.

Conclusions

Lower T2 relaxation times of tibial cartilage in fractured ankles suggest intact extra cellular matrix (ECM) of the cartilage. Severity of the ankle fracture, measured by ankle stability, does not seem to increase ECM degradation immediately after trauma.

Subchondral bone cysts remodel after correction of varus deformity in ankle arthritis

BACKGROUND

Subchondral bone cysts (SBCs) of the talus are frequently observed in ankle osteoarthritis (OA). It is unclear whether the cysts need direct treatment after correction of the varus deformity in ankle OA. The purpose of this study is to investigate the incidence of SBCs and the change after supramalleolar osteotomy (SMOT).

METHODS

Thirty-one patients treated by SMOT were retrospectively reviewed, and 11 ankles had cysts preoperatively. After SMOT without management of the cysts, the evolution of cysts was evaluated on weightbearing computerized tomography (WBCT). The American Orthopaedic Foot and Ankle Society (AOFAS) clinical ankle-hindfoot scale and a visual analog scale (VAS) were compared.

RESULTS

At baseline, the average cyst volume was 65.86 ± 60.53 mm3. The number and volume of cysts were reduced dramatically (P＜.05), and the cysts vanished in 6 ankles after the SMOT. The VAS and AOFAS scores improved significantly after SMOT (P＜.001), there was no significant difference between ankles with cysts and without cysts.

CONCLUSIONS

The SMOT alone without direct treatment of the SBCs led to a decrease in the number and volume of SBCs in varus ankle OA.

LEVEL OF EVIDENCE

Level IV, case series.

Five-Factor Modified Frailty Index as a Predictor of Complications Following Total Ankle Arthroplasty

INTRODUCTION

Ankle arthritis adversely affects patients' function and quality of life. Treatment options for end-stage ankle arthritis include total ankle arthroplasty (TAA). A 5-item modified frailty index (mFI-5) has predicted adverse outcomes following multiple orthopaedic procedures; this study evaluated its suitability as a risk-stratification tool in patients undergoing TAA.

METHODS

The National Surgical Quality Improvement Program (NSQIP) database was retrospectively reviewed for patients undergoing TAA between 2011 and 2017. Bivariate and multivariate statistical analyses were performed to investigate frailty as a possible predictor of postoperative complications.

RESULTS

In total, 1035 patients were identified. When comparing patients with an mFI-5 score of 0 versus ≥2, overall complication rates significantly increased from 5.24% to 19.38%, 30-day readmission rate increased from 0.24% to 3.1%, adverse discharge rate increased from 3.81% to 15.5%, and wound complications increased from 0.24% to 1.55%. After multivariate analysis, mFI-5 score remained significantly associated with patients' risk of developing any complication (P = .03) and 30-day readmission rate (P = .005).

CONCLUSIONS

Frailty is associated with adverse outcomes following TAA. The mFI-5 can help identify patients who are at an elevated risk of sustaining a complication, allowing for improved decision-making and perioperative care when considering TAA.

LEVELS OF EVIDENCE

III, Prognostic.

Reflections on Presurgical and Postsurgical Gait Mechanics After 50 Years of Total Ankle Arthroplasty and Perspectives on the Next Decade of Advancement

Although not the most prevalent form of lower limb pathology, ankle arthritis is one of the most painful and life-limiting forms of arthritis. Developing from overuse and various traumatic injuries, the effect of ankle arthritis on gait mechanics and effective treatment options for ankle arthritis remain an area of extensive inquiry. Although nonsurgical options are common (physical therapy, limited weight-bearing, and steroidal injections), surgical options are popular with patients. Fusion remains a common approach to stabilize the joint and relieve pain. However, starting in the early 1970s, total ankle arthroplasty was proposed as an alternative to fusion.

Passive Dynamic Ankle Foot Orthoses Use in Civilian Patients with Arthritic Conditions of the Foot and Ankle

Background

Nonsurgical interventions such as bracing with ankle foot orthoses (AFOs) aim to assist, restore, and redirect weightbearing forces to address difficulty with mobilization. We identified a custom carbon fiber passive dynamic ankle foot orthosis (PDAFO) that was designed to meet the needs of military combat veterans. We sought to evaluate the off-loading properties of one model of PDAFO (ExoSym) in a civilian population.

Methods

Civilian patients 18 years or older were prescribed a PDAFO by a single surgeon. Pedobarographic data were obtained using the Tekscan F-Scan system. With the insole, participants were instructed to walk at a self-selected pace along a 20 m walkway under 3 conditions: (1) insole placed in between the brace and foot (over); (2) insole placed between the brace and insole of the shoe (under); (3) without the brace, the insole was placed in between the foot and insole of the shoe in both limbs (without).For assessment, forefoot and heel areas were evaluated with respect to maximal force, force*time integral (FTI), maximal contact area, maximal contact pressure, pressure*time integral (PTI), center of force (COF) excursion.

Results

Six patients with arthritic foot and ankle conditions completed pedobarographic assessment for analysis. The brace reduced forefoot maximal force and contact pressures by 66% and 49%, respectively (538 ± 236 to 185 ± 130 N [P < .001], and 99 ± 38 to 50 ± 24 P < .002). Additionally, participants were observed to load the forefoot portion of the brace with double the maximum contact pressures compared to the unbraced foot (204 ± 57 to 99 ± 38 kPa, P < .001).

Conclusion

The results of this study showed that the PDAFO unloaded substantial force and pressure experienced by the forefoot. Participants loaded the brace to a greater extent than when going unbraced. ADAFO can provide measurable pressure relief for patients with arthritic conditions.

Level of Evidence

Level IV, case series.

Complications after total ankle arthroplasty- A systematic review

BACKGROUND

Total ankle arthroplasty was developed as an alternative option to ankle arthrodesis in patients with end-stage ankle osteoarthritis. Multiple trials have assessed the outcomes of ankle arthroplasty, but complication risk or relative effectiveness is not systematized in literature.

AIM

Review complications of new designs of total ankle arthroplasty and the relationship between their severity and failure rates.

METHODS

We reviewed complications and revision rates of prospective studies of primary total ankle arthroplasty that included more than 50 patients and with minimum 2 years follow-up.

RESULTS

We included 22 studies (4412 ankles, median age of 61.9 years) with an adjusted mean follow-up time of 66.6 ± 40.9 months. The adjusted mean complication rate was 23.7 % (2.4-52 %), mostly high-grade complications (35.6 %). We found a statistically significant positive correlation between high- and medium-grade complications and revision rates.

CONCLUSION

Patient selection is crucial to successfully treat end-stage ankle osteoarthritis. Further multicenter clinical trials with consistent reporting of complications are warranted.

Foot and Ankle Motion after Tibiotalocalcaneal Arthrodesis: Comparison with Tibiotalar Arthrodesis Using a Multi-Segment Foot Model

BACKGROUND

Tibiotalocalcaneal arthrodesis is an established surgical procedure for treating patients with end-stage ankle joint arthritis and subtalar joint arthritis. Although it greatly relives pain, a major drawback is loss of range of motion. Although it is known to restrict an additional subtalar joint compared to tibiotalar arthrodesis, there is a lack of gait analysis studies comparing the two methods. This study aimed to evaluate the differences in kinematics of the foot and ankle joints between tibiotalar and tibiotalocalcaneal arthrodesis. We also compared preoperative and postoperative statuses for each surgical method.

METHODS

The study included 12 and 9 patients who underwent tibiotalar and tibiotalocalcaneal arthrodesis, respectively, and 40 healthy participants were included in the control group. The DuPont foot model was used to analyze intersegmental foot and ankle kinematics during gait.

RESULTS

Compared to controls, both tibiotalar and tibiotalocalcaneal arthrodesis resulted in slow gait speed with reduced stride length, increased step width, and decreased range of sagittal plane motion. Both fusion methods showed similar range of motion in all segments and planes following surgery. Coronal positions showed more supination of the forefoot and pronation of the hindfoot segment after each operation, particularly tibiotalocalcaneal arthrodesis. Gait after tibiotalocalcaneal arthrodesis did not significantly differ from that after tibiotalar arthrodesis, but there was a tendency of more pronation in the hindfoot segment.

CONCLUSIONS

Both fusion methods limited foot and ankle motion in similar ways. Comparing tibiotalar and tibiotalocalcaneal arthrodesis suggests that additionally fusing the subtalar joint does not cause greater movement restriction in patients. Objectively comparing tibiotalar and tibiotalocalcaneal arthrodesis will facilitate further understanding of the effect of tibiotalocalcaneal arthrodesis on movement and the value of subtalar joint motion for improved preoperative counselling.

97 HINTEGRA ankle prostheses: Results and survival at more than 5 years' follow-up

BACKGROUND

In Europe, fixed-bearing implants predominate again in total ankle replacement (TAR). The present single-center single-surgeon study assesses the Hintegra® mobile-bearing implant (NEWDEAL).

METHODS

Between November 2008 and November 2015, 97 Hintegra® were implanted in 94 patients: mean age, 62.4±10.9 years (26-83); 59% (57/97) male; normal mean body-mass index (BMI), 27.5 ± 4.3 kg/m². Indications mainly comprised posttraumatic (40.2%), instability (29.9%) and primary osteoarthritis (16.5%). 17.5% of patients had prior surgery during the previous 6 months (9 fusions, 8 ligament reconstructions, and 4 osteotomies); in 59.8%, other procedures were associated to TAR. Functional, clinical and radiological follow-up was conducted at 1 year, 2 years and last follow-up (>5 years).

RESULTS

Ninety-four TARs were analyzed at a mean 81 ± 21.6 months (19-124). Revision-free survival was 76% (95% confidence interval (95%CI): 0.66-0.8), and explantation-free survival 92% (95%CI: 0.85-1) with 10 cases of curettage and 5 explantations. Mean AOFAS score improved from 41.8 ± 12.5 (21-69) to 77.5 ± 16.5 (24-100) up (p < 0.001); 75% of patients had no or only mild pain (p < 0.001). Clinical ranges of motion were 8.0 ± 7.1° dorsiflexion (p < 0.001) and 35.1 ± 9.4° plantar flexion (preoperatively, 34.1 ± 7.9°) (p = 0.71). Radiologically, tibial components were well-positioned; 87% of talar components were well-centered. Global ankle range of motion was 23.5 ± 10.2° (5-48) (p = 0.17). 54.6% of TARs showed posterior tibial calcification at follow-up. Risk of severe cyst (>1 cm) on CT was 36% (95%CI: 23-47) at a mean 77 ± 21.9 months (18-123).

CONCLUSION

Hintegra® TAR incurred a low risk of revision, and is a reliable option for ankle osteoarthritis.

LEVEL OF EVIDENCE

IV.

Cadaveric Gait Simulation of the Effect of Subtalar Arthrodesis on Total Ankle Replacement Kinematics

BACKGROUND

Patients undergoing total ankle replacement (TAR) often have symptomatic adjacent joint arthritis and deformity. Subtalar arthrodesis can effectively address a degenerative and/or malaligned hindfoot, but there is concern that it places abnormal stresses on the TAR and adjacent joints of the foot, potentially leading to early TAR failure. This study hypothesized that ankle and talonavicular joint kinematics would be altered after subtalar arthrodesis in the setting of TAR.

METHODS

Thirteen mid-tibia cadaveric specimens with neutral alignment were tested in a robotic gait simulator. To simulate gait, each specimen was secured to a static mounting fixture about a 6-degree of freedom robotic platform, and a force plate moves relative to the stationary specimen based on standardized gait parameters. Specimens were tested sequentially in TAR and TAR with subtalar arthrodesis (TAR-ST_fuse). Kinematics and range of motion of the ankle and talonavicular joint were compared between TAR and TAR-ST_fuse.

RESULTS

There were significant differences in kinematics and range of motion between TAR and TAR-ST_fuse groups. At the ankle joint, TAR-ST_fuse had less internal rotation in early-mid stance (P < .05), with decreased range of motion in the sagittal (-2.7 degrees, P = .008) and axial (-1.8 degrees, P = .002) planes in early stance, and increased range of motion in the coronal plane in middle (+1.2 degrees, P < .001) and late (+2.5 degrees, P = .012) stance. At the talonavicular joint, there were significant differences in axial and coronal kinematics in early and late stance (P < .05). Subtalar arthrodesis resulted in significantly decreased talonavicular range of motion in all planes in early and late stance (P < .003).

CONCLUSION

In ankles implanted with the TAR design used in this study, kinematics of the ankle and talonavicular joint were found to be altered after subtalar arthrodesis. Aberrant motion may reflect altered contact mechanics at the prosthesis and increased stress at the bone-implant interface, and affect the progression of adjacent joint arthritis in the talonavicular joint.

CLINICAL RELEVANCE

These findings may provide a correlate to clinical studies that have cited hindfoot arthrodesis as a risk factor for TAR failure.

Short-Term Outcomes of Primary Total Ankle Arthroplasty in Octogenarians: A National Database Analysis

BACKGROUND

Total ankle arthroplasty (TAA) is an increasingly popular option for end-stage ankle arthritis. Americans over the age of 80 years grew to 16.7 million in 2010, but there are scarce data assessing the outcomes of octogenarians undergoing TAA. This study evaluated (1) perioperative factors, (2) 30-day postoperative complications compared to a nonoctogenarian cohort, and (3) independent risk factors for adverse outcomes.

METHODS

A national database registry was queried for patients who had undergone primary TAA. This yielded 1113 patients, under (n = 1059) and over (n = 54) age 80 years. Demographics and perioperative data were compared using Fisher's exact, χ², and independent-samples t tests. Logistic and Poisson regressions were used to calculate odds ratio (OR) of complications and independent risk factors.

RESULTS

The octogenarian cohort had longer in-hospital length of stay (1.9 vs 2.5 days, P < .0001). Octogenarians were not significantly more likely to develop any complication (OR = 1.32; 95% confidence interval = 0.29-6.04; P = .722), or increased number of complications (OR = 1.18; 95% CI = 0.27-5.18; P = .820). Octogenarians had significantly increased risk of being discharged to rehab/skilled nursing (OR = 6.60; 95% CI = 2.16-20.15; P < .001) instead of home.

CONCLUSION

Although the elderly population may carry inherent risk factors, octogenarians do not present an increased risk of short-term complications following TAA.

LEVELS OF EVIDENCE

Therapeutic, Level III: Retrospective cohort study.

Total ankle replacement with INBONE-II prosthesis: A short-to-medium-term follow-up study in China

BACKGROUND

Total ankle replacement (TAR) is a viable option for the treatment of end-stage ankle arthritis. In China, the INBONE-II implant is the only total ankle prosthesis approved since 2016. The purpose of this study is to report a large sample of findings for the TAR with INBONE-II prosthesis.

METHODS

A total of 65 patients with end-stage ankle arthritis, who underwent primary TAR using INBONE-II by the same surgeon from 2016 to 2019, at a single institution were included in this retrospective, single-center study. Clinical data, radiographic findings, survival rate, and complications were recorded and assessed pre-operatively and at the most recent follow-up.

RESULTS

A total of 64 patients were available for follow-up at least 2 years after surgery; the mean follow-up duration for clinical outcomes was 37.9 months (24-59 months), and for radiographic findings was 22.8 months (12-59 months). There were significant improvements (P < 0.01) in the American Orthopedic Foot and Ankle Society hindfoot scale, the visual analog scale for pain, and the Short Form-36. There were statistically significant differences between pre-operative and post-operative comparisons of the talar tilt angle (TT) and the tibial lateral surface angle (TLS) in the radiographic findings (TT from 4.7 ± 4.3° to 1.3 ± 1.3°, TLS from 80.4 ± 7.7° to 87.4 ± 2.3°, P < 0.01). There was no statistically significant difference in improvement of the tibial anterior surface angle (P = 0.14). Ten complications (all low grade) were recorded according to the Glazebrook classification system. The survivorship of the prosthesis was 100% (64/64).

CONCLUSION

Patients who underwent TAR with INBONE-II prosthesis demonstrated significant improvements in all measures of pain and function as well as in radiographic findings. High survival and a low incidence of complications were observed in this study.

Ankle osteoarthritis: comprehensive review and treatment algorithm proposal

Ankle osteoarthritis (OA) is much less frequent than knee or hip OA, but it can be equally disabling, greatly affecting the quality of life of the patients.

Approximately 80% of ankle OA is post-traumatic, mainly secondary to malleolar fractures, being another of the main causes untreated in chronic instability. The average age of the patient affected by ankle OA is around 50 years, being therefore active patients and in working age who seek to maintain mobility and remain active.

The authors conducted a comprehensive review of the conservative, medical, and surgical treatment of ankle OA.

Initial conservative treatment is effective and should be attempted in any stage of OA. From a pharmacological point of view, non-steroidal anti-inflammatory drugs (NSAIDs) and intra-articular infiltrations can produce temporary relief of symptoms.

After the failure of conservative-medical treatment, two large groups of surgical treatment have been described: joint-preserving and joint-sacrificing procedures.

In the early stages, only periarticular osteotomies have enough evidence to recommend in ankle OA with malalignment. Both ankle arthrodesis and ankle replacement can produce satisfactory functional results if correctly indicated in the final stages of the disease.

Finally, the authors propose a global treatment algorithm that can aid in the decision-making process.

Preliminary Report of a Hybrid Total Ankle Arthroplasty Combining a Stemmed Intramedullary Tibial Component With Chamfer-Cut Talar Dome

Total ankle arthroplasty (TAA) is a viable treatment for end-stage ankle arthritis. In our experience, a stemmed intramedullary tibial component combined with a chamfer-cut talar component provides the most stable construct for TAA. We present our technique for placement of this hybrid prosthesis utilizing the INBONE tibial component in combination with the INFINITY talar component. This technique differs from the standard protocol by minimizing use of both patient-specific and standard intraoperative guides. The primary aim of this study is to report our preliminary outcomes with our novel technique. Secondarily, we aim to demonstrate that placement of this hybrid prosthesis is radiographically reproducible and accurate. The first 10 patients undergoing this technique with at least 1 year of follow-up were retrospectively reviewed. Average visual analog pain scale decreased from 7.4 preoperatively to 0.5 at 1 year postoperatively. The average time to weightbearing was 6.4 weeks. Complications were minimal, and no implant-related complications were encountered. First weightbearing ankle radiographs postoperatively were evaluated by 3 reviewers to determine accuracy of the tibial intramedullary stem in relation to the anatomical axis of the tibia. We found that the deviation of the tibial implant from the anatomic axis was on average 0.9°± 0.5° in the coronal plane, and 2.2°± 2.7° in the sagittal plane. Inter-rater reliability was 83%. We conclude that this hybrid technique utilizing a stemmed intramedullary tibial component in combination with a chamfer-cut talar component for TAA is reproducible, accurate, and safe.

The Most-Cited Ankle Arthroplasty Implant Articles

Background:

Citation analysis is a useful way of evaluating the impact, importance, and merit of articles within a medical specialty. Our study identified and analyzed the most-cited articles on ankle arthroplasty implants to evaluate their importance in the field of ankle arthroplasty research.

Methods:

Using the keywords “ankle arthroplasty” and “ankle replacement” and the search period 1970-2021, we found 3728 articles on ankle arthroplasty implants in the Scopus, Web of Science, and MEDLINE/PubMed databases. We included original articles, reviews, clinical trials, and case reports in the study. We retrieved the 50 most-cited articles published during the time frame and then screened them for studies of specific ankle arthroplasty implants and their postoperative outcomes. We also recorded and analyzed the articles’ subjects, authorship, journals, countries of origin, and years of publication.

Results:

The 50 most-cited articles were published between 1983 and 2014, with the majority (33) published between 2000 and 2010. They generated 9012 citations in the literature. The most-cited study accounted for 497 citations; the mean number of citations per article was 180.24 ± 76.24. Twenty-three (46%) of the articles addressed postoperative outcomes following a specific type of arthroplasty implant. Arthroplasty implant studies accounted for 4726 citations, or 52.4% of the citations of the 50 articles. The most frequently studied arthroplasty implant was STAR (15), followed by Agility (7), Buechel Pappas (5), and Salto (4). STAR accounted for 3311 citations, or 37% of the total citations of the 50 articles.

Conclusion:

Ankle arthroplasty research has made great progress in the past 2 decades, particularly in the area of postoperative outcomes of specific ankle implants, but continued research and publication on additional arthroplasty implants should become a priority.

Level of Evidence:

Level V, Review Article.

Effects and Safety of Intra-Articular Sodium Hyaluronate Injection for the Treatment of Ankle Osteoarthritis: A Prospective Clinical Trial

Various nonoperative treatments have been implemented to reduce pain and improve the quality of life in patients with ankle osteoarthritis. Among these treatments, intra-articular hyaluronate injection has proven efficacy and safety in patients with knee osteoarthritis. The purpose of this study was to evaluate the efficacy and complications of hyaluronate injection using various clinical scoring systems. This study included 37 patients with unilateral ankle osteoarthritis (grade 2 or 3 according to the Takakura classification) who did not respond to previous pharmacological treatment. 3 weekly hyaluronate injections (2 mL Hyruan Plus®) were administered. The efficacy of intra-articular hyaluronate injection was evaluated on the basis of patient-reported foot and ankle clinical assessment at a mean follow-up of 13.8 ± 8.3 (range 6-33) months. Ankle Osteoarthritis Scale scores for pain and disability, American Orthopedic Foot and Ankle Society ankle-hindfoot scores, and visual analog scale for pain significantly improved at the final follow-up compared to that before intra-articular hyaluronate injection (p ≤ .05). When patients were dichotomized according to age, sex, body mass index, symptom duration, and Takakura classification, all these factors were not related to clinical outcomes. This study suggests that 3 weekly intra-articular hyaluronate injections can be performed safely to reduce pain and improve function without serious complications in patients with early or intermediate-grade ankle osteoarthritis when patients inadequately respond to medication. Larger controlled studies are needed to clarify the effects of hyaluronate injection and identify patients who can benefit most from hyaluronate injection.

The Role of Distraction Arthroplasty in Managing Ankle Osteoarthritis

Ankle distraction arthroplasty (DA) is a joint-preserving option for the treatment of ankle osteoarthritis. The ideal patient is a young, active person who is compliant with follow-up and understands that clinical improvements may not be fully evident until 1 year after surgery. The procedure promotes cartilage healing and regeneration by removing mechanical stress at the joint surface through the application of a joint-spanning external fixator. There is an array of adjuvant procedures commonly performed to optimize healing potential-including microfracture, osteophyte removal, osteotomies, and soft tissue balancing procedures. Short- and intermediate-term studies have been promising, though there is a wide variance in reported failure and complication rates.

Visualization and quantification of the degenerative pattern of the distal tibia and fibula in unilateral varus ankle osteoarthritis

The present study aimed to quantify and visualize the degenerative patterns of the distal tibia and fibula due to ankle osteoarthritis (OA). We analyzed differences in tibial and fibular surface deviation between sides of patients with unilateral varus ankle OA (medial talar tilt > 4°) by registering each surface model to the mirror image of corresponding bone. Computed tomography images of both feet of 33 patients (OA: 22, control: 11) were examined. Statistically significant surface depression of approximately 2.5 mm on the anterior articular surface of the medial malleolus, and surface elevation of approximately 1 mm on the anterodistal edge of the tibiofibular joint and the lateral malleolus were observed in OA patients. These bone degenerations were found to be correlated with those on the other side of the ankle joint, the medial margin of the talar trochlea and the lateral articular surface of the talus, respectively. In contrast, the amount of bone depression on the plafond was smaller than previously anticipated. Such quantitative information about stereotypical patterns of bone degeneration in ankle OA would contribute to better understanding of the development of ankle OA and possible therapeutic interventions.

Ankle fusion and replacement gait similar post-surgery, but still exhibit differences versus controls regardless of footwear

Persons with ankle osteoarthritis (AOA) often seek surgical intervention to alleviate pain and restore function; however, recent research has yielded no superior choice between the two primary options: fusion and replacement. One factor yet to be considered is the effect of footwear on biomechanical outcomes. Comparisons of AOA biomechanics to a normative population are also sparse. The objectives of this study were to (1) determine how footwear uniquely affected gait in persons with ankle fusion and replacement and (2) provide context for AOA biomechanics via comparisons to a healthy adult sample. Thirty-four persons with AOA performed overground walking trials barefoot and shod before surgical intervention and then received either an ankle fusion (n = 14) or replacement (n = 20). Two and/or three years post-surgery, patients returned for gait analysis. Nineteen controls performed the same gait procedures during a single study visit. Spatiotemporal variables and peak angles, internal moments, powers, and forces were calculated to quantify gait behavior. Overall, the two surgical groups performed similarly to each other but demonstrated marked differences from controls both pre- and post-surgery. No significant differences were detected when examining the effect of footwear. The motion of the midfoot with respect to the hindfoot and forefoot may be instrumental in gait biomechanics following an ankle fusion or replacement and should be considered in future investigations.

Open versus arthroscopic ankle arthrodesis in high-risk patients: a comparative study

PURPOSE

Arthroscopic ankle arthrodesis is known to offer high fusion rates, improvements in pain and functional outcomes, low risks of complications, and reinterventions. The aim of this study is to compare open vs. arthroscopic ankle arthrodesis in patients at high risk of complications.

METHODS

A single-centre retrospective comparative analysis of ankle fusions was conducted. Patient records were screened for demographics, type of arthrodesis, follow-up length, pre-operative diagnosis, risk factors for non-union, operative time, radiographic union, time to union, complications, and reinterventions. The American Orthopedic Foot & Ankle Society (AOFAS) Ankle-Hindfoot Scale, the Italian version of the Foot Function Index (FFI), and a visual analog scale (VAS) for pain scores collected pre-operatively and in the last follow-up were used to assess clinical outcomes.

RESULTS

There were 23 open and 21 arthroscopic ankle fusions. Union rate was higher (90.5% vs. 65.2%, p < 0.05) and complication rate was lower (14.3% vs. 47.8%, p < 0.05) in the arthroscopic group. In addition, patients who underwent arthroscopic arthrodesis reported better pain control, with higher improvements in VAS for pain scores. There was no significant difference in length of operative time, time to fusion, AOFAS, and FFI scores improvements between the two groups.

CONCLUSIONS

Arthroscopic ankle arthrodesis resulted in higher union rates, fewer complications, and lower reoperation rates in patients at high risk of complications.

Improvement in Health-Related Quality of Life After Total Ankle Arthroplasty Compares Well With Other Successful Orthopaedic and Nonorthopaedic Procedures

Background. Ankle arthritis is a major cause of disability. Orthopaedic literature suggests improvement in health-related quality of life (HRQOL) after total ankle arthroplasty (TAA). This has not been compared with improvements observed in successful orthopaedic and nonorthopaedic procedures, including anterior cervical discectomy/fusion (ACDF), total knee arthroplasty (TKA), coronary artery bypass grafting (CABG), and orthotopic liver transplant (OLT). We hypothesize that the effects after TAA are comparable to several successful surgical procedures. Methods. 500 consecutive TAA patients were included and grouped with 2 other large series. Short Form-36 (SF36) were collected at standardized intervals. A systematic literature review identified studies comparing preoperative and postoperative SF36 physical (PCS) and mental component summary (MCS) scores. Using meta-analyses, we pooled the data for each procedure to compare with the TAA group. Results. Patients in all cohorts had preoperative SF36 MCS and PCS scores that were significantly lower than that in the general population. Improvements in HRQOL after TAA were not statistically different from improvements reported in PCS and MCS after ACDF, TKA, and OLT. However, improvement in PCS after TAA was better than that observed after CABG. Conclusions. Disability with ankle arthritis is severe. Disability associated with cervical disc disease, knee arthrosis, coronary artery disease, and liver failure is also severe, with surgical intervention providing major improvements in HRQOL postoperatively. The improvement in HRQOL after TAA did not differ statistically from ACDF, TKA, CABG, and OLT. Our investigation suggests that the HRQOL benefits of TAA meet benchmarks set by some of modern medicine's best.Levels of Evidence: Level III: Systematic review.

Ankle Osteoarthritis Aetiology

Ankle osteoarthritis affects 1% of the population and, unlike gonarthrosis or coxarthrosis, is secondary to previous trauma in more than 75% of cases. Another peculiarity of this disease is that it affects a younger and active population, with socio-occupational implications. Mechanical factors, such as incongruity, instability, malalignment, and impacts, which increase stress on isolated areas of the ankle cartilage, have been clearly associated with the development of osteoarthritis. However, we cannot ignore the importance of pro-inflammatory mediators present from the moment of fracture as triggers of the cascade that eventually causes chondrocyte cell death, ultimately responsible for ankle osteoarthritis.

Efficacy and Safety of a Single Intra-articular Injection of Platelet-rich Plasma on Pain and Physical Function in Patients With Ankle Osteoarthritis-A Prospective Study

Ankle osteoarthritis (OA) can cause disabling symptoms, and some patients prefer to be treated with minimally invasive procedures. The aim was to evaluate the efficacy and safety of a single intraarticular injection of platelet-rich plasma (PRP) for patients with ankle OA. In a prospective study done in a university-affiliated tertiary care medical center, 44 patients with symptomatic ankle OA for at least 6 months were recruited. Patients received a single injection of PRP (3 mL) into symptomatic ankles. The primary outcome was the change from baseline in the visual analog scale (VAS) pain (0-10 cm) at 6 months. Secondary outcomes included the Ankle Osteoarthritis Scale (AOS) score, American Orthopedic Foot and Ankle Society (AOFAS) hindfoot-ankle score, single-leg stance test (SLS), rescue analgesics consumption and patient satisfaction. Thirty-nine participants (88.64%) completed the study. Significantly improvement in the VAS and AOS was noted at 1-, 3-, and 6-month follow-ups (p < .001). The mean VAS pain decreased significantly from 4.1 ± 1.7 at baseline to 2.2 ± 1.9, 1.7 ± 1.5, and 1.8 ± 1.6 at 1, 3, and 6 months (p < .001). The mean total AOS score reduced by 1.5, 2.2, and 2.1 from baseline respectively postinjection (p < .001). The mean AOFAS hindfoot-ankle score improved from 80.3 points at baseline to 87.2, 91.6, and 89.7 points at 1, 3, and 6 months (p < .001). SLS tests improved significantly (p < .001) at each follow-up. Acetaminophen consumption dropped significantly (p < .001) and no serious adverse events occurred. The study showed promise for a single intraarticular injection of PRP in the treatment of ankle OA.

Clinical Outcomes of Total Ankle Arthroplasty Versus Ankle Arthrodesis for the Treatment of End-Stage Ankle Arthritis in the Last Decade: a Systematic Review and Meta-analysis

Ankle arthrodesis (AA) and total ankle arthroplasty (TAA) are the 2 primary surgical treatments for patients with end-stage ankle arthritis. The comparative outcomes between AA and TAA using modern techniques remain unclear. A systematic search to identify all relevant articles comparing AA with TAA was conducted through 3 online databases. The clinical outcomes were extracted for meta-analysis, including AOFAS (American Orthopaedic Foot & Ankle Society) score, VAS (visual analog scale), AOS (Ankle Osteoarthritis Scale), gait analysis, ROM (range of motion), satisfaction, complication, and reoperation. Our meta-analysis shows no heterogeneity in any subgroup analyses. There were no significant differences in AOFAS total, pain, and alignment scores between the AA and TAA groups. The TAA group had significant improvement in AOFAS function score compared with the AA group. There was no significant difference in VAS and AOS total scores between the 2 groups. No significant differences in gait analysis were observed between the 2 groups. The TAA group had significant improvement in both ROM and change in ROM compared with the AA group. There was no significant difference in satisfaction rate between the 2 groups. The TAA group had significantly higher complication and reoperation rates compared with the AA group. Our meta-analysis provides updated evidence on clinical outcomes comparing AA with TAA using third-generation implants. The TAA group had better improvement in AOFAS function and ROM than the AA group. No significant differences in pain relief, gait analysis, or patient satisfaction were observed between the 2 groups.

The use of intra-articular injection of autologous micro-fragmented adipose tissue as pain treatment for ankle osteoarthritis: a prospective not randomized clinical study

PURPOSE

The objective of this study was to evaluate the safety and the efficacy of intra-articular injections of autologous micro-fragmented adipose tissue in patients affected by early or moderate ankle osteoarthritis (AOA).

METHODS

A total of 31 symptomatic patients, aged 28-71 years, affected by AOA, were treated with 5 ml of autologous micro-fragmented adipose tissue. Clinical evaluations before the treatment and after six, 12, and 24 months were performed through American Orthopaedic Foot and Ankle Society (AOFAS) scale, the Foot and Ankle Disability Index (FADI), and Visual Analogue Scale (VAS) scores. Adverse events were recorded.

RESULTS

No severe complications were noted during the treatment and the follow-up period. A statistically significant improvement from basal evaluation to the six, 12-, and 24-month follow-up visit was observed, whereas a statistically significant worsening from the 12-month to the 24-month follow-up visit was showed.

CONCLUSION

The autologous micro-fragmented adipose tissue for the treatment of pain in ankle osteoarthritis seems safe and able to provide positive clinical outcomes, potentially offering a new minimally invasive therapeutic option for patients who are not eligible for more invasive approaches. Further high-quality studies are needed to confirm these findings.

Effect of Patient Demographics on Minimally Important Difference of Ankle Osteoarthritis Scale Among End-Stage Ankle Arthritis Patients

BACKGROUND

Ankle replacement and ankle arthrodesis are standard treatments for treating end-stage ankle arthritis when conservative treatment fails. Comparing patient-reported outcome scores to the instrument's minimal important difference (MID) helps physicians and researchers infer whether a meaningful change in health from the patient's perspective has occurred following treatment. The objective of this study was to estimate the MID of the Ankle Osteoarthritis Scale among a cohort of operatively treated end-stage ankle arthritis patients undergoing ankle replacement or arthrodesis.

METHODS

A survey package including the Ankle Osteoarthritis Scale was completed by participants preoperatively and 2 years postoperatively. Distribution and anchor-based approaches to calculating the MID were used to estimate the MID of the Ankle Osteoarthritis Scale and its 2 domains. The distribution-based approaches used were the small and medium effect size methods, while the mean absolute change method and linear regression method were the anchor-based approaches. Bootstrap sampling was used to obtain the variance of MID estimates. The MID was estimated for sex, age, operative, and baseline health subgroups. The cohort comprised 283 participants, totaling 298 ankles.

RESULTS

The MID did not vary with sex or operative procedure. Age-based differences in MID values may exist for the Ankle Osteoarthritis Scale total score, and MID values were generally smallest among the oldest patients. Patients with the best and worst ankle-related health preoperatively had higher MID values than patients reporting mid-range Ankle Osteoarthritis Scale values preoperatively.

CONCLUSION

The best estimate of the MID of the Ankle Osteoarthritis Scale total score is 5.81. Our findings indicate that the MID of the Ankle Osteoarthritis Scale may not vary by sex or operative subgroups but likely varies by age and preoperative Ankle Osteoarthritis Scale score.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Clinical outcome results of total ankle replacement and ankle arthrodesis: a pilot randomised controlled trial

BACKGROUND

Ankle arthrodesis (AA) and replacement (TAA) are widely accepted options in managing end-stage ankle arthritis (ESAA). We hypothesize that clinical outcomes would be similar for both interventions.

METHODS

We conducted a multicenter randomized controlled trial that collected data on patient demographics, complication rates, Ankle Osteoarthritis Scale (AOS) and Short Form-36 (SF-36) scores. We evaluated pre and postoperative scores within and between cohorts.

RESULTS

The thirty-nine ankles enrolled had a mean follow-up of 5.1 ± 2.8 years. Total AOS scores improved significantly in both groups; 59.4 ± 15.9 to 38 ± 20 (p-value = 0.002) for TAA and 64.6 ± 19.7 to 31.8 ± 16.5 (p-value < 0.001) for AA at last follow-up. Complication rate was higher in the AA cohort with four major complications (20%).

CONCLUSION

We observed a statistically significant benefit with TAA and AA. As a pilot trial, this study is meant to inform on design and feasibility of future RCTs.

LEVEL OF EVIDENCE

II.

Converting Ankle Arthrodesis to a Total Ankle Arthroplasty

Several articles in the literature discuss the positive results of converting a painful ankle fusion to an ankle replacement. Our results confirm that in well-selected cases a conversion to a total ankle replacement is not only possible, but also significantly improves quality of life and reduces pain. The outcome of a total ankle replacement after an ankle fusion depends to a degree on the method of fusion. Less destructive fusion that is arthroscopic has better results than conventional transfibular open fusions. Absence of a fibula should be an absolute contraindication for a conversion.

A Survey for End-Stage Ankle Arthritis Treatment: Ankle Arthrodesis Versus Ankle Arthroplasty

With promising technological advances, ankle arthroplasty has become an alternative to arthrodesis, traditionally the gold standard, for treating end-stage ankle arthritis. We collected knowledge and perceptions on both procedures to determine the need for a patient decision aid for these patients by administering a cross-sectional survey to 103 orthopaedic surgeons. Respondents were predominantly male and 41 to 50 years old. Half of those who stated that they do not perform arthroplasty said this was because they do not have adequate training. Additionally, certain variables were associated with the surgeon's choice of intervention: patient gender, age, body mass index, postoperative activity level, employment type, perceived risk of infection, neurovascular injury or wound complication, risk of developing or pre-existing adjacent arthritis, deformity, malalignment, bone loss or abnormal bone quality, number of prior ankle operations, cause of arthritis, and desire for motion preservation. The majority agreed that they always incorporate patient preferences into their decisions and that a decision aid would be beneficial. This survey revealed that several patient characteristics are influential in the surgeon's preference for either arthroplasty or arthrodesis for end-stage ankle arthritis. Because the majority of surgeons incorporate patient preferences in their decisions and report that a decision aid would be beneficial for informed decision-making in this clinical scenario, this survey identified an unmet need supporting the development of such a tool for these patients.

Infinity ankle arthroplasty with traditional instrumentation and PSI prophecy system: preliminary results

Ankle arthrodesis has been considered the surgical Gold Standard for advanced ankle arthritis; prosthetic replacement of the tibio-talar joint played a secondary role.The introduction of last generation ankle prostheses lead to better outcome and a lower rate of complication. PSI represents the most recent innovations introduced on the market of ankle arthroplasty:PSI is proposed as a surgical technique capable of making ankle arthroplasty more accurate and more reproducible compared to standard referencing guides Aim of the study is to report early clinical and radiographic outcomes obtained from a single surgeon experience by implanting the same ankle prosthesis using a standard (STD) or a PSI instrumentation Unlike no difference in the average increment of normalized sub score related to function in each group (PSI vs STD), the analysis of normalized pain sub score pointed out a greater average improvement in the PSI group(+75%)compared to the STD group(+62%);this result has been adovacated to the absence of post operative gutter impingement syndrome in the PSI group compared to the STD referencing group. The analysis of radiographic angles revealed a more accurate and reproducible positioning of the components in the PSI group; ankle arthroplasty performed with PSI reported a reduction of both surgical times and the need of intraop.fluoroscopy. PSI ankle arthroplasty achived more accurate and reproducible clinical and radiographic results compared to STD instrumentation;long-term follow-up are needed to demonstrate whether a better positioning of the implant is associated with an increased survival of the prosthesis and therefore justifies the additional costs of PSI.

Clinical evaluation of arthrodesis with Ilizarov external fixator for the treatment of end-stage ankle osteoarthritis: A retrospective study

To analyze the efficacy of arthrodesis with Ilizarov external fixator for the treatment of end-stage ankle osteoarthritis.This retrospective study included 88 patients with end-stage (stage-3) ankle osteoarthritis according to Morrey-Wiedeman classification who underwent arthrodesis with Ilizarov external fixator from January 2016 to January 2019. There were 47 males and 41 females with a mean age of (57.21 ± 7.12) years old (range 49-76). Outcomes were measured by the American Orthopaedic Foot and Ankle society (AOFAS) Ankle Hindfoot Scale, Visual Analog Scale (VAS) pain scores, complications, subjective satisfaction, ankle function, correction of deformity, and complications.With an average follow-up of (13.50 ± 5.41) months (range 10-21), all 88 patients returned for final follow-up. All patients achieved bony healing with a success rate of 100%. Mean postoperative healing time (3.56 ± 1.04) months (range 3-6). Two patients developed sinus tract infection, delayed healing in 1 patient, and 2 patients had pain and swelling again in the ankle joint. No serious complications occurred in other patients. All the patients evaluated with the VAS scores and AOFAS scores at final follow-up showed significant improvement (P < .05). Through imaging analysis, medical tibial talar angle (MTTA) improved from (85.76 ± 6.01) degrees to (88.98 ± 1.35) degrees postoperative. Lateral talar station (LTS) decreased from (5.32 ± 3.81) mm to (2.71 ± 2.62) mm after operation (P < .05). The overall satisfaction of patients is 88.64%.In the treatment of end-stage ankle osteoarthritis, arthrodesis with Ilizarov external fixator can achieve good radiological and clinical outcomes with low prevalence of ankle joint malalignment and high fusion rates and satisfaction.

A case of osteophyte excision and arthroscopic arthrodesis for tarsal tunnel syndrome with traumatic osteoarthritis of the ankle

•

We successfully treated tarsal tunnel syndrome (TTS) accompanied with traumatic osteoarthritis of the ankle.

•

Osteophyte excision for the TTS and arthroscopic for the osteoarthritis was effective for even TTS with traumatic osteoarthritis of the ankle.

•

There were many advantages in arthroscopic ankle arthrodesis, compared with open ankle arthrodesis.

Introduction

There are some reports of tarsal tunnel syndrome (TTS) entrapment/impingement from bony factors, including exostosis and fragment, but there are no reports on TTS with traumatic osteoarthritis of the ankle that were treated with osteophyte excision for TTS and arthroscopic arthrodesis for osteoarthritis of the ankle.

Presentation of case

A 61-year-old woman with left trimalleolar fracture had undergone surgery 3 years earlier and was referred to our hospital for further investigation of persistent left ankle pain and numbness around the left medial malleolus and plantar aspect of the foot. Clinical examination demonstrated plantar hypesthesia and a positive Tinel’s sign at the tarsal tunnel. Imaging showed severe osteoarthritic change in the ankle and an osteophyte of the posteromedial distal tibia that appeared to be impinging on the tibial nerve. We performed arthroscopic ankle arthrodesis, which is less invasive than the open procedure, with removal of the osteophyte as the cause of TTS. Tarsal tunnel exploration revealed a large osteophyte pushing on the tibial nerve, and the osteophyte was removed.

Discussion

About 8 weeks after surgery, bony union was achieved. At the 2-year follow-up visit, the patient could perform daily activities with almost no pain or numbness. This case offers further insight into the management of TTS with traumatic osteoarthritis of the ankle.

Conclusion

We report here successful treatment of a rare case of tarsal tunnel syndrome (TTS) accompanied with traumatic osteoarthritis of the ankle, treated with osteophyte excision for the TTS and arthroscopic for the osteoarthritis.

Blood-induced cartilage damage alters the ankle joint load during walking

Ankle cartilage damage due to repeated joint bleeds often leads to altered gait in adult patients with hemophilia. It is therefore of clinical importance to develop an understanding of the biomechanical gait features in hemophilia patients with and without blood-induced cartilage damage and age-matched control subjects. We recruited a control group (n = 17), patients with hemophilia (PwH) without blood-induced ankle cartilage damage (PwH__NoCartDam , n = 5) and PwH with severe blood-induced ankle cartilage damage (PwH__CartDam , n = 19). We collected three-dimensional gait analysis data with following outcome variables in the ankle, Chopart and the first metatarsophalangeal (MTP 1) joints: range of motion (ROM) during stance phase, peak joint moment and powers. Biomechanical loading (BW) was quantified as the joint reaction forces using inverse dynamic analysis. Loading rate (BW/s) and impulse (BW*s) were calculated between 50% and 70% of stance phase. All biomechanical variables of the ankle joint were significantly lowered in the PwH__CartDam group compared with both the control subjects and the PwH__NoCartDam group. No compensatory biomechanical function was observed in other foot joints. An ankle loading rate of 2.64 ± 0.83 BW/s was observed in the control group, which was significantly higher than 1.75 ± 0.43 BW/s (P = .049) and 1.22 ± 0.59 BW/s (P < .001) in respectively the PwH__NoCartDam group and PwH__CartDam group. Patients with severe blood-induced cartilage damage demonstrated a (mal)adaptive gait strategy as they experience difficulties to properly unload the ankle cartilage during walking.

Functional and radiological medium term outcome following supramalleolar osteotomy for asymmetric ankle arthritis- A case series of 33 patients

Introduction

Ankle arthritis is one of the most disabling and painful conditions. Up to 37.5% of ankle arthritis presents as asymmetric arthritis with ankle malalignment. Supramalleolar osteotomy is a joint sparing operation, which aims to realign the ankle joint that will prevent progression of arthritis and relieve patient's symptoms.

Aim

The aim of this study is to analyse the medium term functional and radiographic outcomes of patients who underwent supramalleolar osteotomy for asymmetric ankle arthritis.

Materials and methods

This is a retrospective outcome study of medium term outcome for 33 patients who underwent Supramalleolar osteotomy for asymmetric ankle arthritis by a single surgeon. We assessed the functional outcome of the patients with AOFAS and VAS score. The radiological parameters measured were Tibial articular surface ankle (TAS), Hind foot alignment angle (HFA) and Talar tilt angle (TT). We used the paired Student's t-test to compare the preoperative and postoperative radiographic measurements, AOFAS and VAS scores. We set the significance level at P < 0.05.

Results

We had 21 patients who underwent lateral closing wedge osteotomy for varus deformity and 12 patients who underwent medial closing wedge osteotomy for valgus deformity. The mean followup was 72 months [29-73]. The mean AOFAS score significantly improved by 44.82 ± 7.97 (p < 0.0001). The VAS score significantly improved by 5.06 ± 1.41 (p < 0.0001). All the radiological parameters showed statistically significant improvement. All osteotomy united by 8-10 weeks. We had one case of late deep wound infection, which settled down with by metalwork removal. The arthritis progressed in three cases, two patients had fusion and one patient had ankle replacement. We had 90.9% survival rate for our osteotomy at 6 years.

Conclusion

Supramalleolar osteotomy is an excellent option for patients with asymmetric ankle arthritis with good functional and radiological outcome and good medium term survival rate.

Ligament stabilization improved clinical and radiographic outcomes for individuals with chronic ankle instability and medial ankle osteoarthritis

PURPOSE

Chronic ankle instability with a long symptom duration is often accompanied by medial compartment ankle osteoarthritis (OA). However, the outcomes of individuals after ligament stabilization have rarely been reported. The radiographic and clinical outcomes after ligament stabilization in individuals with chronic ankle instability and medial compartment OA were investigated.

METHODS

The study investigated 27 ankles with chronic ankle instability and medial compartment OA that underwent lateral ankle ligament reconstruction from 2007 to 2015 with a follow-up period of at least 1 year. Ligament stabilization was performed via either the modified Broström procedure (MBP) or lateral ankle reconstruction (LAR) using semitendinosus tendon allografts.

RESULTS

The median instability duration was 60 (range 12-480) months, and the median follow-up period was 39 (range 12-108) months. The preoperative Takakura ankle OA stage was predominantly stage I (20 patients (74.1%)), followed by stage II (five patients (18.5%)). Ankle MRI (20 ankles) revealed medial cartilage denudation in three cases (15%), cartilage thinning in nine cases (45%), osteophyte formation in ten cases (50%), and loose body formation in six cases (30%). According to the arthroscopic results, the modified Outerbridge grade was two in nine cases and four in ten cases, so these grades were the most common (37.5% and 41.7%, respectively). The MBP was performed in 14 patients, and LAR was performed in 13 patients (52% and 48%, respectively); the bone marrow stimulation procedure was performed in 15 patients (55%). The visual analogue scale score decreased from 6.0 (SD 1.6) preoperatively to 1.8 (SD 1.6) postoperatively (p = 0.000). The American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score improved from 61.9 (SD 14.2) to 89.7 (SD 6.2), and the Karlsson-Peterson score improved from 54.7 (SD 13.9) to 88.3 (SD 9.0) (p = 0.000). There were no serious complications, and all patients were satisfied.

CONCLUSIONS

Ligament stabilization with arthroscopic procedures for individuals with chronic ankle instability and medial ankle OA yielded significant functional outcomes with high patient satisfaction, even without radiographic improvement.

LEVEL OF EVIDENCE

IV.

Low Tibial Valgization Osteotomy for More Severe Varus Ankle Arthritis

BACKGROUND

Low tibial valgization osteotomy with medial opening wedge (LTO) is generally indicated for ankle arthritis with a small talar tilt (TT). We addressed the following research questions: the efficacy of LTO for more significant varus ankle arthritis, the effect of additional inframalleolar correction followed by LTO, and the preoperative or operation-related factors influencing postoperative TT decrease.

METHODS

We retrospectively reviewed the radiographic and clinical findings of 31 patients with more significant varus ankle arthritis (≥8 degrees) who underwent LTO or LTO plus inframalleolar correction. We grouped the included patients according to combination with inframalleolar correction and postoperative decreased TT. Furthermore, a binary logistic regression analysis was performed to determine the factors influencing postoperative TT decrease.

RESULTS

Even though the mean TT was unchanged postoperatively (from 12.1 to 9.9 degrees, P = .052), clinical parameters were significantly increased. In the group with concomitant inframalleolar correction, we found that TT was more corrected (3.9 vs 1.8 degrees, P = .023) with a greater lateralization of the talar center and a greater correction of the hindfoot alignment to valgus. The results of the binary logistic regression analysis showed a significant relationship between postoperative decreased TT and preoperative talar center migration (P = .016), hindfoot alignment angle (P = .033), hindfoot moment arm (P = .041), and hindfoot alignment ratio (P = .016).

CONCLUSION

LTO in more significant varus ankle arthritis could result in clinical improvement, although TT was not significantly changed. We recommend adding inframalleolar correction after LTO for the patients with more significant varus ankle arthritis.

LEVEL OF EVIDENCE

Level III, comparative series.