Total ankle replacement

The morphometry of distal tibia and posterior malleolus and its clinical implications in total ankle prosthesis

PURPOSE

The aim of this study is to reveal the morphometry of the distal tibia and posterior malleolus and to generate morphometric reference data for the tibial component of total ankle prosthesis.

METHODS

This study was performed on 121 human dry tibiae (47 right, 74 left). The morphometric measurements of distal tibial structures, tibial length and the distance between the medial and posterior malleolus were measured in this study. Measurements on 44 tibiae were repeated three times and averaged for minimizing intra-observer error.

RESULTS

The tibial length was found 34.19 ± 2.31 cm. Mean values of width of fibular notch at tibial plafond and 10 mm proximal to the tibial plafond were 25.71 ± 2.44 mm and 17.81 ± 2.46 mm, respectively. Mean depth of fibular notch at tibial plafond and 10 mm proximal to the tibial plafond were 3.60 ± 1.04 mm and 3.37 ± 1.24 mm, respectively. Mean height of fibular notch was found 48.21 ± 10.51 mm. Mean width and height of medial malleolus were 25.08 ± 2.13 mm and 14.73 ± 1.85 mm, respectively. Mean width and length of tibial plafond were 27.71 ± 2.74 mm and 26.96 ± 2.62 mm, respectively. Mean values of width and height of posterior malleolus were measured 21.41 ± 3.26 mm and 6.74 ± 1.56 mm, respectively. Mean distance between medial and posterior malleolus was found 37.17 ± 3.53 mm. Mean width and depth of malleolar groove were 10.26 ± 1.84 mm and 1.73 ± 0.75 mm, respectively. The mean intra-class correlation values were found between the 0.959 and 0.999.

CONCLUSIONS

Knowing the distal tibial morphometry is crucial for designing convenient ankle replacement implants for Turkish population. To our knowledge, this study is the first in the literature that identifies posterior malleolar morphometry on dry tibiae. We believe that this study will make a significant contribution to the literature about distal tibial morphometry and especially the posterior malleolus and the data of our study can be used for designing total ankle prosthesis in Turkish population.

Outcome after total ankle replacement or ankle arthrodesis in end-stage ankle osteoarthritis on the basis of german-wide data: a retrospective comparative study over 10 years

BACKGROUND

In symptomatic end-stage osteoarthritis of the ankle joint, total ankle replacement and ankle arthrodesis are the two primary surgical options for patients for whom conservative treatment fails. Published revision rates are often biased and difficult to compare. In this study, unplanned reoperation rates and revision rates were determined for both surgical interventions based on a large dataset, and risk factors for unplanned reoperations were identified.

METHODS

German-wide health data of the largest German health-care insurance carrier between 2001 and 2012 were retrospectively analyzed, and unplanned reoperation rates within 10 years were determined for index surgeries conducted in 2001 and 2002. Unplanned reoperation rates within 5 years for index surgeries conducted in 2001/2002 were compared to index surgeries conducted in 2006/2007. Multivariate logistic regression was used to identify risk factors for unplanned reoperations.

RESULTS

After ankle arthrodesis, 19% (95% confidence interval [CI], 16-22%) of 741 patients needed to undergo an unplanned reoperation within ten years. After total ankle replacement, the unplanned reoperation rate was 38% [95% CI, 29-48%] among 172 patients. For initial surgeries conducted at a later date, unplanned reoperation rates within five years were 21% [95% CI, 19-24%] for 1,168 ankle arthrodesis patients and 23% [95% CI, 19-28%] for 561 total ankle replacement patients. Significant risk factors for unplanned reoperations after ankle arthrodesis in the initial cohort were age < 50 years (odds ratio [OR] = 4.65 [95% CI 1.10;19.56]) and osteoporosis (OR = 3.72 [95% CI, 1.06;13.11]); after total ankle replacement, they were osteoporosis (OR = 2.96 [95% CI, 1.65;5.31]), Patient Clinical Complexity Level (PCCL) grade 3 (OR = 2.19 [95% CI, 1.19;4.03]), PCCL grade 4 (OR = 2.51 [95% CI, 1.22;5.17]) and diabetes mellitus (OR = 2.48 [95% CI, 1.33;4.66]). Kaplan-Meier analyses including 1,525 ankle arthrodesis patients and 644 total ankle replacement patients revealed an average unplanned reoperation-free time of approximately 17 years for both procedures.

CONCLUSIONS

Similar revision rates and unplanned reoperation rates for both procedures in the later-date cohort can likely be attributed to a learning curve for surgeons as well as advances in implant design. This analysis of billing health insurance data supports an increase in total ankle replacement surgeries.

Revision Total Ankle Arthroplasty Using a Novel Modular Fixed-Bearing Revision Ankle System

INTRODUCTION

Large bone defects such as those encountered after failed total ankle replacement have previously been a relative contraindication to revision ankle replacement due to inadequate bone stock. We describe our experience and patient reported outcomes with a modular ankle replacement system with tibial and talar augments.

METHODS

This is a retrospective case series analysis of patients who underwent a total ankle replacement using the INVISION system across 2 centers between 2016 and 2022. Patients completed the Manchester-Oxford Foot Questionnaire (MOXFQ), Ankle Osteoarthritis Scale (AOS), and EQ-5D pre-operatively and then post-operatively at 6 months, 1 year, 2 years, 3 years, and 5 years. Medical records were reviewed for complications and re-operations. X-rays were reviewed for lucencies and alignment.

RESULTS

A total of 17 patients were included in the study; 14 men and 3 women with an average age at the time of surgery of 67.9 years (range 56-80 years). The average follow-up post-operatively was 40.5 months (range 7-78) at the time of this study. The indication for surgery was revision of failed total ankle replacement (TAR) in 16 and revision of failed ankle fusion in 1. An augmented tibia was used in 13, an augmented talus in 13, and both augmented tibia and talus in 9 cases. There were no early surgical complications. One patient required debridement and implant retention for late deep infection. No implants have been revised. The average MOXFQ score improved by 19.3 points at most recent follow-up. The average AOS score improved by 25.2 points.

CONCLUSION

The early results of a modular augmented ankle arthroplasty system have shown satisfactory patient outcomes with a low complication and re-operation rate and present another option for patients with larger bone defects. This is a small series, and a larger series with long-term follow-up would be beneficial.

LEVELS OF EVIDENCE

Level IV: Case series.

A Novel Orthoplastic Reconstruction of Relapsed Clubfoot With Total Ankle Arthroplasty

Congenital clubfoot is addressed in infancy and rarely persists into adulthood. Ankle arthroplasty is an increasingly popular surgical intervention for patients with ankle arthritis since it allows a natural ankle range of motion and completely replaces a degenerative hindfoot. Here, we describe the first successful total ankle arthroplasty (TAA) for a patient with previously treated congenital clubfoot that reverted later in life. To address the patient's poor soft-tissue integument and reduce the likelihood of post-surgical complications, a perioperative latissimus muscle-free flap was performed. This two-staged, novel orthoplastic intervention addressed our patient's ankle issues and appears to be a viable option for clubfoot patients.

Fast-Track for Total Ankle Replacement: A Novel Enhanced Recovery Protocol for Select Patients

BACKGROUND

Enhanced recovery after surgery programs, also called fast-track protocols, were developed and successfully applied in the last decade for hip and knee reconstruction. Specific fast-track protocols have not yet been applied to ankle prostheses. The aim of the study was to develop and validate an enhanced recovery protocol for total ankle replacement (TAR) evaluating the clinical and radiographic results. We hypothesize that on the basis of well-defined pre- and postoperative characteristics, the current knowledge on ankle replacement, and referring to hip and knee reconstruction, it is possible to identify a "patient type" to be safely eligible to a Fast-Track Protocol with at least comparable results and without increasing the complications risk.

METHODS

We identified 8 predictive variables that might affect the outcome of TAR. Those variables were the body mass index, the state of anxiety or depression, the functional preoperative status, ankle equinus, the coronal malalignment, the surgical time, the surgical accessory procedures, and the bone quality. These characteristics were evaluated for each patient with almost validated outcome tools attributing a specific score. Based on the score obtained, the patients were divided into 2 groups: the Standard Protocol group (Control Group) and the Fast-Track Protocol group (Study Group). The main difference between treatment of the 2 groups relates to the use of postoperative plaster casts: in the Fast-Track group the cast was removed the first day after surgery and walking was allowed in sports shoes assisted with crutches, whereas in the Standard Protocol group, the cast was removed after 3 weeks. Clinical and radiographic evaluation was performed for all patients preoperatively and postoperatively every 6 months.

RESULTS

A total of 163 patients received a score between 1 and 5 and were included in the control group (Standard Protocol); 47 patients received a score of 0 and were allocated to the study group (Fast-Track Protocol). Clinically, except for the preoperative American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scale score, no statistically significant differences were recorded in the multiple comparisons between the 2 groups. No significant differences were found regarding complications.

CONCLUSION

In selected patients, it is possible to apply an enhanced recovery protocol of rehabilitation, focused on immediate weightbearing and mobilization without any plaster or boot.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

[Postprimary early elective total arthroplasty in severe ankle fractures]

Treatment of the ankle joint with total ankle arthroplasty (TAA) is an established and safe surgical treatment for osteoarthritis of the ankle. Modern implants have low revision rates and are superior to ankle arthrodesis in terms of patient-reported outcomes. The importance of primary TAA treatment of ankle fractures is unclear. There are currently no studies in the literature on this topic. In view of the increasing number of cases of unstable ankle fractures, especially in older patients and with increasing functional demands also in old age, it is important to consider TAA in the management of these fractures in the future. Clinical studies are necessary to evaluate the treatment of ankle fractures using TAA.

Intermediate to long-term clinical outcomes and survival analysis of the Salto Mobile Bearing total ankle prothesis

INTRODUCTION

Osteoarthritis of the ankle is a major burden to affected patients. While tibio-talar arthrodesis has been the gold-standard regarding the treatment of osteoarthritis of the ankle joint for many years, at present total ankle arthroplasty (TAA) provides appealing clinical outcomes and is continually gaining popularity. The aim of this study was to evaluate the intermediate- to long-term clinical outcome including the survival rate of Salto Mobile Bearing TAA (Tonier SA, Saint Ismier, France).

MATERIAL AND METHODS

In this retrospective study intermediate- to long-term outcomes measures [Ankle Range of Motion (ROM), American Orthopaedic Foot and Ankle Score (AOFAS score) and survival rate] of 171 consecutive TAA were analysed and compared before and after surgery. Revision was defined as secondary surgery with prothesis component removal, while reoperation was defined as a non-revisional secondary surgery involving the ankle.

RESULTS

At a mean follow-up (FU) period of 7.2 ± 2.7 years (range 2.0 to 14.1 years) there was a significant improvement in ankle ROM (total ROM improved from 25.0° ± 15.0° to 28.7° ± 11.3°, p = 0.015; plantarflexion improved from 18.4° ± 11.7° to 20.6° ± 8.2°, p = 0.044; dorsiflexion improved from 6.6° ± 5.7° to 8.1° ± 4.9°, p = 0.011). AOFAS score increased significantly by 41 ± 15 points after surgery (43.3 ± 11.1 before and 84.3 ± 12.0 after surgery, p < 0.001). Overall survival rate within the FU was 81.3% (95% CI 75.3% to 87.3%) with any secondary surgery, 89.9% (95% CI 84.1% to 93.6%) with revision and 93.6% (95% CI 89.8% to 97.3%) with reoperation as endpoint.

CONCLUSION

This study endorses the previously reported appealing intermediate- to long-term outcomes of the Salto Mobile Bearing TAA. There was a significant increase in ROM and AOFAS score as well as decent implant survival at final FU.

The Impact of Hospital Size and Teaching Status on Outcomes Following Total Ankle Arthroplasty

The popularity and utilization of total ankle arthroplasty (TAA) as treatment for ankle arthritis has increased exponentially from 1998 to 2012. Overall the outcomes have improved for TAA with the introduction of new-generation implants and this has increased the focus on optimizing other variables affecting outcomes for TAA. The purpose of this study was to examine the effects of hospital characteristics and teaching status on outcomes for TAA. The Nationwide Inpatient Sample database was queried from 2002 to 2012 using the ICD-9 procedure code for TAA. The primary outcomes evaluated included: in-hospital mortality, length of stay, total hospital charges, discharge disposition, perioperative complications, and patient demographics. Analyses were carried out based on hospital size: small, medium, and large; and teaching status: rural nonteaching, urban nonteaching, and urban teaching. A total weighted national estimate of 16,621 discharges for patients undergoing TAA was reported over the 10-year period. There were significant differences in length of stay and total charges between all hospitals when comparing location and teaching status; however, no significant differences were noted for in-hospital mortality. Rural, nonteaching hospitals had higher odds of perioperative complications. There were also significant differences in length of stay and total charges when comparing hospital sizes. Overall, there is no increased risk of mortality after TAA regardless of hospital size or setting. However, rural hospitals had increased rates of perioperative complications compared to urban hospitals. Our analyses demonstrated important factors affecting cost and resource utilization for TAA, clearly additional work is needed to optimize this relationship, especially in the upcoming bundled payment models.

[Mid- and long-term effectiveness analysis of distraction arthroplasty in treatment of moderate to severe ankle arthritis]

Objective

To investigate the mid- and long-term effectiveness of external fixator distraction arthroplasty in the treatment of moderate to severe ankle arthritis.

Methods

The clinical data of 23 patients with moderate to severe ankle arthritis treated with external fixation distraction arthroplasty who met the selection criteria between January 2007 and November 2019 were retrospectively analyzed. There were 20 males and 3 females; the age ranged from 21 to 65 years, with an average age of 43.7 years. Etiology included 8 cases of primary ankle arthritis, in which 5 cases combined with varus deformity; 15 cases of traumatic ankle arthritis, the cause of injury was 5 cases after ankle fracture surgery, 3 cases after Pilon fracture surgery, 5 cases of chronic ankle instability and repeated sprain, and 2 cases of other causes. According to Takakura staging system, there were 4 cases of stage ⅢA, 12 cases of stage ⅢB, and 7 cases of stage Ⅳ; according to Giannini staging system, there were 5 cases of stage Ⅱ and 18 cases of stage Ⅲ; according to Cheng staging system, 16 cases were in stage Ⅲ, and 7 cases stage Ⅳ. American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score and visual analogue scale (VAS) score were used to evaluate the improvement of ankle pain and function before operation and at last follow-up, and the data were analyzed according to different etiological groups. At last follow-up, the surgical results were evaluated subjectively and objectively. The changes of ankle joint space before operation and at last follow-up were compared. The patients were divided into two groups according to their age: ≤45 years old group [young group, 10 cases, aged (35.62±7.41) years old] and >45 years old group [middle-aged and elderly group, 13 cases, aged (54.20±6.20) years old]. The AOFAS ankle-hindfoot score and VAS score were compared before and after operation between the two groups, and the influence of age on distraction arthroplasty was analyzed.

Results

The external fixator was removed after 3 months of continuous distraction,12 patients got infection around the wire tunnels. All the 23 patients were followed up 13-143 months, with an average of 56.9 months; the follow-up time was (43.46±32.77) months and (69.80±37.79) months in the young group and middle-aged and elderly group, respectively. At last follow-up, the AOFAS ankle-hindfoot score and VAS score significantly improved when compared with those before operation ( P<0.05). According to etiological analysis, there was no significant difference in AOFAS ankle-hindfoot score and VAS score before and after operation ( P>0.05) in Pilon fracture patients, while the significant difference was found in remaining patients ( P<0.05). There was significant difference in AOFAS ankle-hindfoot score before operation between the young group and the middle-aged and elderly group ( t=2.110, P=0.040), but no significant difference in preoperative VAS score and the differences in VAS score and AOFAS ankle-hindfoot score before and after operation between the two groups ( P>0.05). The subjective and objective results of pain evaluation at last follow-up showed that 4 patients had no pain, 12 patients had moderate pain relief, 5 patients had mild pain relief, and 2 patients had no significant pain relief; among the 10 patients who were followed up more than 5 years, there were 2, 5, 2, and 1 patient, respectively; 2 patients who were followed up more than 10 years had moderate pain relief. At last follow-up, the ankle joint space was (3.7±0.4) mm, which significantly increased when compared with before operation [(1.5±0.2) mm] ( t=1.791, P=0.002). The ankle joint space was (2.9±0.5) mm in 10 patients who were followed up more than 5 years, and 3.3 mm and 3.0 mm in 2 patients who were followed up more than 10 years.

Conclusion

Distraction arthroplasty of the ankle joint can achieve satisfactory results in patients with moderate to severe ankle arthritis (except for arthritis caused by Pilon fracture), and age has no significant effect on distraction arthroplasty.

The talar body prosthesis treated end-stage ankle arthritis with talar body deficient: a 6-13 years of follow-up outcomes and 6-year survivorship

INTRODUCTION

Talar body deficient provides a unique challenge for ankle arthritis treatment. We studied the clinical-radiographic outcomes at 6 to 13 years and 6 year prosthesis survivorship of patients treated for ankle arthritis with poor talar body bone stock using a talar body prosthesis (TBP).

MATERIALS AND METHODS

Between 2008 and 2015, we treated 32 consecutive end-stage ankle arthritis patients with talar body deficiency by TBP implantation and fascia interposition. One patient was excluded with a diagnosis of inflammatory arthritis. We assessed visual analogue scale (VAS) of ankle pain, sagittal range of motion, American Orthopaedics Foot and Ankle Society (AOFAS) ankle-hindfoot score, Foot Ankle Ability Measure (FAAM) of activity daily living (ADL), prosthesis tibiotalar surface angle, radiographic prosthesis loosening, adjacent joint arthritis and complication. Pre-operative to last follow-up outcomes (at 6-13 years) were compared. Prosthesis survivorship was analyzed at 6 year follow-up. p < 0.05 was considered a significant difference.

RESULTS

There was statistically significant improvement of median VAS ankle pain, as 8.0 (IQR 1.0) to 1.0 (IQR 2.0), AOFAS ankle-hindfoot score from 48 (IQR 21) to 80 (IQR 7.0), FAAM of ADL from50.0 (28.0) to 88.0 (IQR 15.0), and sagittal ROM from 20^o (IQR 19°) to 33° (IQR 14°), p < 0.05. The median tibiotalar surface angle was statistically significant improved from 85.0° (IQR 8.0°) to 89.0° (IQR 3.0°), p < 0.001. No radiographic prosthesis loosening or adjacent talonavicular-calcaneocuboid joint arthritis. The 6 year prosthesis survivorship was 93.5% (95% CI 84.9-100.0%). End of survivorship was observed in 2 patients due to progressive valgus tilting at 16° and 18°, respectively. No prosthesis was revised.

CONCLUSIONS

TBP implantation with fascia replacing the articular end of distal tibia provided significant better pre- to post-operative clinical outcomes and had 6 year survivorship as 93.5% for the treatment of ankle arthritis with talar body deficient.

LEVEL OF EVIDENCE

IV.

Total Ankle Replacement Provides Symmetrical Postoperative Kinematics: A Biplane Fluoroscopy Imaging Study

BACKGROUND

In vivo measurements of tibiotalar and subtalar joint motion following TAR are unavailable. Using biplane fluoroscopy, we tested the hypothesis that the prosthetic tibiotalar joint and adjacent subtalar joint would demonstrate kinematic and range of motion differences compared to the contralateral untreated limb, and control participants.

METHODS

Six patients of 41 identified candidates that all underwent unilateral Zimmer TAR (5.4 ± 1.9 years prior) and 6 control participants were imaged with biplane fluoroscopy during overground walking and a double heel-rise activity. Computed tomography scans were acquired; images were segmented and processed to serve as input for model-based tracking of the biplane fluoroscopy data. Measurements included tibiotalar and subtalar kinematics for the TAR, untreated contralateral, and control limbs. Statistical parametric mapping quantified differences in kinematics throughout overground walking and the double heel-rise activity.

RESULTS

Patients with this TAR performed walking and heel-rise activities symmetrically with no significant kinematic differences at the tibiotalar and subtalar joints between limbs. Compared to control participants, patients exhibited reduced dorsi/plantarflexion range of motion that corresponded to decreased peak dorsiflexion, but only in the late stance phase of walking. This reduction in tibiotalar dorsi/plantarflexion range of motion in the TAR group became more apparent with double heel-rise activity.

CONCLUSION

Patients with a Zimmer TAR had symmetric kinematics during activities of walking and double heel-rise, but they did exhibit minor compensations in tibiotalar kinematics as compared to controls.

CLINICAL RELEVANCE

The lack of significant kinematic compensation at the subtalar joint may explain why secondary subtalar osteoarthritis is reported as being relatively uncommon in patients with some TAR designs.

Transfibular total ankle arthroplasty : a new reliable procedure at five-year follow-up

AIMS

This study reports updates the previously published two-year clinical, functional, and radiological results of a group of patients who underwent transfibular total ankle arthroplasty (TAA), with follow-up extended to a minimum of five years.

METHODS

We prospectively evaluated 89 patients who underwent transfibular TAA for end-stage osteoarthritis. Patients' clinical and radiological examinations were collected pre- and postoperatively at six months and then annually for up to five years of follow-up. Three patients were lost at the final follow-up with a total of 86 patients at the final follow-up.

RESULTS

A total of 86 patients were evaluated at a mean follow-up of 65.4 months (60 to 90). At five-year follow-up, statistically significant improvements (p < 0.001) were found in the mean American Orthopaedic Foot & Ankle Society Ankle Hindfoot Score (from 33.8 (SD 14.3) to 86.1 (SD 8.8)), visual analogue scale for pain (from 8.5 (SD 1.7) to 1.5 (SD 1.2)), Short Form-12 Physical and Mental Component Scores (from 29.9 (SD 6.7) and 43.3 (SD 8.6) to 47.3 (SD 7.5) and 52.2 (SD 8.0), respectively), and mean ankle dorsiflexion and plantarflexion (from 6.2° (SD 5.5°) and 9.6° (SD 5.8°) to 23.9° (SD 7.7°) and 16.9° (SD 7.2°), respectively). Radiologically, the implants maintained neutral alignment without subsidence. Tibial or talar radiolucency was found in eight patients, but none of these patients was symptomatic. At five-year follow up, 97.7% of implants (95% confidence interval 91.2 to 99.4) were free from revision or removal with 84 implants at risk. We recorded two cases (2.3%) of failure for septic loosening.

CONCLUSION

Transfibular TAA is safe and effective with a high survival rate at mid-term follow-up and satisfactory clinical and radiological results. Further studies are required to determine the long-term performance of these implants. Cite this article: Bone Joint J 2022;104-B(4):472-478.

Superiority of upper ankle arthrodesis over total ankle replacement in the treatment of end-stage posttraumatic ankle arthrosis

PURPOSE

Surgical treatment of end-stage posttraumatic upper ankle arthrosis is challenging. Highly variable revision rates have been reported with total ankle arthroplasty (TAA) of the upper ankle joint. The aim of this retrospective study was to compare revision rates with tibiotalar arthrodesis (TTA) and TAA with a prosthesis to determine the superior treatment approach.

METHODS

Data for 148 patients (96 males and 52 females) with end-stage posttraumatic upper ankle arthrosis-including 88 treated with TTA and 60 with TAA between 2008 and 2013, with a mean follow-up of 59 months-were analysed. Bone fusion was confirmed by x-ray radiography and computed tomography.

RESULTS

The overall revision rate was 28%; the rate was higher with TAA (42%) than with TTA (18%). The TAA group showed an increase in revisions from 12- to 24-month postsurgery. The most common cause of revision in the TAA group was cysts (20%), and the most frequent reason for revision was nonunion (8%). Mean American Orthopaedic Foot and Ankle Society (AOFAS) and Foot and Ankle Outcome (FAO) scores in all patients were 55.5 and 53.1, respectively, with no significant difference between the TTA and TAA groups (p > 0.05). In nine cases (15%) the prosthesis was explanted or converted to TTA. TAA patients who underwent conversion to TTA had worse outcomes (AOFAS score = 39; FAO score = 35.29).

CONCLUSION

TAA is associated with a high rate of revisions, especially from the 2nd year postsurgery. Therefore, TTA is the treatment of choice for end-stage posttraumatic upper ankle arthrosis. Level of evidence Level III, comparative series.

[Salvage options following failed total ankle arthroplasty]

The number of patients with osteoarthritis of the ankle, which are treated by arthroplasty, has continuously increased in recent years. The survival time of these implants is far below the results following hip and knee arthroplasty. In some cases a failure rate of approximately 1% per year or a survival rate of 70% after 10 years has been reported. The most frequent reasons for revision of an ankle prosthesis are aseptic loosening, technical implantation errors and persisting pain. For the revision of an ankle prosthesis there are basically two treatment options. For a long time, ankle arthrodesis was considered the gold standard after a failed prosthesis. In recent years, there has been an increasing trend towards re-implantation of an ankle prosthesis, as this preserves the functionality and mobility of the ankle joint as far as possible. Depending on the reason for failure and the size of the bony defect, a decision must be made regarding a one-stage and a two-stage procedure with bone augmentation. This article presents the advantages and disadvantages of arthrodesis and revision arthroplasty after failed primary ankle arthroplasty and highlights the special features of surgery.

Ankle Osteoarthritis

Osteoarthritis (OA) is characterized by a chronic, progressive and irreversible degradation of the joint surface associated with joint inflammation. The main etiology of ankle OA is post-traumatic and its prevalence is higher among young and obese people. Despite advances in the treatment of fractures around the ankle, the overall risk of developing post-traumatic ankle OA after 20 years is almost 40%, especially in Weber type B and C bimalleolar fractures and in fractures involving the posterior tibial border. In talus fractures, this prevalence approaches 100%, depending on the severity of the lesion and the time of follow-up. In this context, the current understanding of the molecular signaling pathways involved in senescence and chondrocyte apoptosis is fundamental. The treatment of ankle OA is staged and guided by the classification systems and local and patient conditions. The main problems are the limited ability to regenerate articular cartilage, low blood supply, and a shortage of progenitor stem cells. The present update summarizes recent scientific evidence of post-traumatic ankle OA with a major focus on changes of the synovia, cartilage and synovial fluid; as well as the epidemiology, pathophysiology, clinical implications, treatment options and potential targets for therapeutic agents.

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.

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.

Investigation of the Average Shape and Principal Variations of the Human Talus Bone Using Statistic Shape Model

Due to the complexity of articular interconnections and tenuous blood supply to the talus, talus fractures are often associated with complications (e.g., avascular necrosis). Currently, surgically fusing the talus to adjacent bones is widely used as treatment to talus fractures, but this procedure can greatly reduce mobility in the ankle and hindfoot. Alternatively, customized talus implants have shown an overall satisfactory patient feedback but with the limitation of high expenses and time-consuming manufacturing process. In order to circumvent these disadvantages, universal talus implants have been proposed as a potential solution. In our study, we aimed to develop a methodology using Statistical Shape Model (SSM) to simulate the talus, and then evaluate the feasibility of the model to obtain the mean shape needed for universal implant design. In order to achieve this, we registered 98 tali (41 females and 57 males) and used the registered dataset to train our SSM. We used the mean shape derived from the SSM as the basis for our talus implant template, and compared our template with that of previous works. We found that our SSM mean shape talus implant was geometrically similar to implants from other works, which used a different method for the mean shape. This suggests the feasibility of SSM as a method of finding mean shape information for the development of universal implants. A second aim of our study was to investigate if one scalable talus implant can accommodate all patients. In our study, we focused on addressing this from a geometric perspective as there are multiple factors impacting this (e.g., articular surface contact characteristics, implant material properties). Our initial findings are that the first two principal components should be afforded consideration for the geometrical accuracy of talus implant design. Additional factors would need to be further evaluated for their role in informing universal talus implant design.

Quality measure of total ankle replacement outcomes in a non-designer centre

BACKGROUND

Total ankle replacement (TAR) is a high-risk procedure with significant revision rates, post-op complications and implant failures. Long term follow-up data is less available for TAR compared to other joint replacement surgeries. To identify optimal follow-up parameters for patients with TAR, we conducted a study on the clinical outcomes and patient-reported outcome measurements (PROMs) in patients who had TAR performed in a non-designer's centre belonging to one of the hospitals of East Lancashire Hospitals NHS Trust (ELHT).

METHODS

60 TAR procedures were identified. Clinical outcomes being studied include post-op ankle range of movement (ROM), American Orthopaedic Foot & Ankle Society (AOFAS) Ankle-Hindfoot scores, reoperation/revision rates, radiological parameters and general surgical outcomes. A Kaplan-Meier survival analysis was also conducted. PROMs data included the EQ-5D index and the Manchester-Oxford Foot Questionnaire (MOX-FQ).

RESULTS

Ankle range of movement and AOFAS scores improved from pre-op to post-op with statistical significance. The reoperation rate and revision rate were 3.3% and 8.3% respectively. 5-year survival of implant was 97.3% and 10-year survival was 84.2%. Overall PROMs data showed improvement from pre-op to post-op.

CONCLUSION

The clinical outcomes of TARs were comparable with conventional literature. Improvements in clinical, radiological and patient-reported outcomes were observed from pre-op to post-op. Further follow-up studies are required to assess the long-term survival of implants.

End-stage Ankle Arthritis Treated by Ankle Arthrodesis with Screw Fixation Through the Transfibular Approach: A Retrospective Analysis

OBJECTIVE

To evaluate the clinical outcome of ankle arthrodesis with screw fixation through the transfibular approach for end-stage ankle arthritis.

METHODS

Data of 22 patients (28 ankles) with end-stage ankle arthritis admitted to the Department of Orthopedics and Surgery of the First Hospital of Jilin University from May 2015 to December 2018 were analyzed retrospectively. The study included 9 men and 13 women, with a mean age of 56.86 ± 11.27 years (range, 37-75 years). The mean duration of the disease was 11.36 ± 12.80 years (range, 3 months-50 years). A total of 16 patients had posttraumatic arthritis, 5 patients had osteoarthritis, and 1 patient had rheumatoid arthritis. There were 12 cases of the left ankle and 16 cases of the right ankle; 16 cases were unilateral and 6 were bilateral. The same surgical procedure was applied to all patients. Collected data included the operation time, intraoperative and postoperative blood loss, hospitalization time, bone union rate, time to bone union, and complications. The American Orthopedic Foot and Ankle Society (AOFAS) ankle hindfoot score and the visual analogue scale (VAS) were used to evaluate the preoperative status and the postoperative outcome at the last follow up.

RESULTS

The mean follow-up period was 26.14 ± 10.99 months. The mean operation time was 101.82 ± 33.33 min. The mean blood loss was 116.78 ± 68.86 mL during the procedure and 111.07 ± 52.18 mL after the procedure. The mean hospitalization time was 14.22 ± 5.42 days. Bone union of the ankle joint was achieved in all patients. The mean time to bone union was 14.83 ± 2.14 weeks. There was significant difference in the operation time between the patients undergoing unilateral and bilateral ankle arthrodesis. The AOFAS ankle hindfoot score increased from the preoperative value of 43.46 ± 4.39 points to 80.39 ± 5.37 points at the last follow up. During the same interval, the VAS score improved from 6.14 ± 0.80 points to 1.64 ± 0.73 points. The AOFAS ankle hindfoot score of patients who underwent unilateral ankle arthrodesis improved from the preoperative 43.19 ± 3.95 points to 81.75 ± 5.23 points at the last follow up, and the VAS score improved from 6.19 ± 0.83 points to 1.69 ± 0.70 points. The AOFAS ankle hindfoot score of patients undergoing bilateral ankle arthrodesis improved from the preoperative value of 43.83 ± 5.08 points to 78.67 ± 5.05 points at the last follow up, while the VAS score improved from 6.08 ± 0.82 points to 1.58 ± 0.79 points. There was significant difference in the maximum walking distance and walking on any surface between the patients undergoing unilateral and bilateral ankle arthrodesis. One patient developed superficial peroneal nerve palsy, which resolved within 1 year after the operation. In another patient, healing of the incision skin was delayed. During the follow-up period, none of the patients developed an infection of the incision or local skin necrosis; screw loosening, withdrawal, or breakage did not occur in any patient.

CONCLUSION

The ankle arthrodesis with screw fixation through the transfibular approach provides satisfactory clinical outcomes for end-stage ankle arthritis.

Methodology for Measurement of in vivo Tibiotalar Kinematics After Total Ankle Replacement Using Dual Fluoroscopy

Biomechanical data could improve our clinical understanding of failures in total ankle replacement (TAR) patients, leading to better surgical approaches and implant designs. Kinematics of the prosthetic tibiotalar joint in TAR patients have yet to be measured using dual fluoroscopy. With dual fluoroscopy, computed tomography (CT) images are acquired to track bone motion. One challenge with this approach is dealing with metal artifact in the CT images that distorts implant visualization and the surrounding bone to implant interfaces. The aim of this study was to develop a methodology to measure in vivo TAR kinematics using inputs of computer-aided design (CAD) models, dual fluoroscopy and CT imaging with metal artifact reduction. To develop this methodology, we created a hybrid three-dimensional (3D) model that contained both: (1) the segmented bone; and (2) the CAD models of the TAR components. We evaluated a patient following total ankle replacement to demonstrate feasibility. The patient performed a self-selected overground walk during which dual fluoroscopy images were collected at 200 Hz. In vivo tracking verifications were performed during overground walking using a distance calculation between the implant articular surfaces to evaluate the model-based tracking 3D solution. Tracking verification indicated realistic alignment of the hybrid models with an evenly distributed distance map pattern during the trial. Articular surface distance calculations were reported as an average of 1.3 mm gap during the entirety of overground walking. The successful implementation of our new tracking methodology with a hybrid model presents a new approach to evaluate in vivo TAR kinematics. Measurements of in vivo kinematics could improve our clinical understanding of failures in TAR patients, leading to better long-term surgical outcomes.

Better implant survival with modern ankle prosthetic designs: 1,226 total ankle prostheses followed for up to 20 years in the Swedish Ankle Registry

Background and purpose - We have previously reported on the prosthetic survival of total ankle replacements (TAR) in Sweden performed between 1993 and 2010. Few other reports have been published on 5- and 10-year survival rates. Furthermore, there is a lack of long-term outcome data on modern prosthetic designs. Therefore, we compared early and current prosthetic designs after a mean 7-year follow-up.Patients and methods - On December 31, 2016, 1,230 primary TARs had been reported to the Swedish Ankle Registry. We analyzed prosthetic survival, using exchange or permanent extraction of components as endpoint for 1,226 protheses with mean follow-up of 7 years (0-24). Differences between current (Hintegra, Mobility, CCI, Rebalance, and TM Ankle) and early prosthetic designs (STAR, BP, and AES) were examined by log rank test.Results - 267/1,226 prostheses (22%) had been revised by December 31, 2016. We found an overall prosthetic survival rate at 5 years of 0.85 (95% CI 0.83-0.87), at 10 years 0.74 (CI 0.70-0.77), at 15 years 0.63 (CI 0.58-0.67), and at 20 years 0.58 (CI 0.52-0.65). For early prosthetic designs the 5- and 10-year survival rates were 0.81 (CI 0.78-0.84) and 0.69 (CI 0.64-0.73) respectively, while the corresponding rates for current designs were 0.88 (CI 0.85-0.91) and 0.84 (CI 0.79-0.88). Current prosthetic designs had better survival (log rank test p < 0.001).Interpretation - Our results point to a positive time trend of prosthetic survival in Sweden; use of current prosthetic designs was associated with better prosthetic survival. Improved designs and instrumentation, more experienced surgeons, and improved patient selection may all have contributed to the better outcome.

[Postoperative MRI of the ankle]

CLINICAL/METHODICAL ISSUE

Postoperative imaging of the ankle can be challenging, even for the experienced radiologist. Pathological and postoperative changes to the primarily complex anatomy of the ankle with its great variety of bone structures, tendons, ligaments, and soft tissue in a very limited space may cause great difficulty in differentiating underlying pathology from expected postoperative changes and artifacts, especially in magnetic resonance imaging (MRI).

STANDARD RADIOLOGICAL METHODS

Selecting the appropriate radiological modality is key to making the correct diagnosis. Therefore, knowledge of the initial and current symptoms is just as important as familiarity with the most frequently performed operations in the ankle.

PRACTICAL RECOMMENDATIONS

This article aims to give its reader a summary of the most important and frequently performed operation techniques of the ankle and discusses the expected appearance and possible complications in postoperative imaging.

Periprosthetic Infection in Joint Replacement

BACKGROUND

The volume of joint replacement surgery has risen steadily in recent years, because the population is aging and increasingly wishes to reserve a high functional status onward into old age. Infection is among the more common complications of joint replacement surgery, arising in 0.2% to 2% of patients, or as many as 9% in special situations such as the implantation of megaprostheses. The associated morbidity and mortality are high. It is thus very important to minimize risk factors for infection and to optimize the relevant diagnostic and therapeutic strategies.

METHODS

This review is based on pertinent publications retrieved by a selective search in PubMed, including current guidelines and expert recommendations.

RESULTS

The crucial diagnostic step is joint biopsy for the identification of the pathogenic organism, which succeeds with over 90% sensitivity and specificity. If the prosthesis is firmly anchored in bone, the pathogen is of a type that responds well to treatment, and symptomatic infection has been present only for a short time, then rapidly initiated treatment can save the prosthesis in 35-90% of cases. The pillars of treatment are thorough surgical care (radical débridement) and targeted antibiotic therapy. On the other hand, if the prosthesis is loose or the pathogen is of a poorly treatable type, the infection can generally only be cured by a change of the prosthesis. This can be performed in either one or two procedures, always in conjunction with systemic antibiotic therapy tailored to the specific sensitivity and resistance pattern of the pathogen.

CONCLUSION

The risk of infection of an artificial joint is low, but the overall prevalence of such infections is significant, as the number of implanted joints is steadily rising. Artificial joint infections should be treated by a standardized algorithm oriented toward the recommendations of current guidelines. Many of these recommendations, however, are based only on expert opinion, as informative studies providing high-grade evidence are lacking. Thus, for any particular clinical situation, there may now be multiple therapeutic approaches with apparently comparable efficacy. Randomized trials are urgently needed.

[Rheumatism operations in a state of flux-"Foot"]

Surgical management of rheumatic feet has dramatically changed over the last decades influenced by the development of new pharmacological drugs and tissue-preserving surgical procedures. It has switched from joint resection to joint-sparing procedures as the method of choice. Nevertheless, the surgical interventions commonly used for non-rheumatic patients cannot be applied to rheumatic patients without reflection: in addition to the basic treatment, comorbidities, degree of mobilization of the patient, orthopedic shoe engineering and orthotic treatment play a major role. Due to the decreasing incidence of the classical rheumatic foot, it has become even more important for physicians, physiotherapists and ergotherapists to recognize the development of such a disease as early as possible and immediately start the appropriate treatment.

The Top 50 most-cited articles on Total Ankle Arthroplasty: A bibliometric analysis

Total Ankle Arthroplasty (TAA) is a relatively new and evolving field in Foot and Ankle surgery. We conducted a citation analysis to identify the characteristics of the top 50 most cited articles on total ankle arthroplasty. Using the Web of Science database and the search strategy total ankle arthroplasty OR total ankle replacement, we identified 2445 articles. After filtering for relevant articles, the top 50 cited articles on total ankle arthroplasty were retrieved for descriptive and statistical analysis. The publication years ranged from 1979 to 2013. USA was the most productive country in terms of research output, followed by the UK. Though citation analysis has its flaws, this is a comprehensive list of the top 50 articles significantly impacting literature on total ankle arthroplasty. Based on our study, we conclude that there is marked deficiency of high level articles with respect to the number of citations and future researches need to cater to this question to produce high quality studies.

Good outcome scores and high satisfaction rate after primary total ankle replacement

Background and purpose - Total ankle replacement (TAR) is gaining popularity for treatment of end-stage ankle arthritis. Large patient-centered outcome studies are, however, few. Here, we report data from the Swedish Ankle Registry. Patients and methods - We examined outcomes after primary TAR in patients from the Swedish Ankle Registry using PROMs (Patient Reported Outcome Measures; generic: EQ-5D and SF-36, region specific: SEFAS (Self-Reported Foot and Ankle Score), and a question on satisfaction). We included 241 patients registered with primary TAR between 2008 and 2016 and who completed PROMs preoperatively and postoperatively up to 24 months. We evaluated changes in PROMs following surgery and estimated effects of age, diagnosis, prosthetic design, and preoperative functional score on the outcomes. Results - All absolute scores improved from preoperative to 24 months after surgery (p ≤ 0.001). 71% of the patients were satisfied or very satisfied at the latest follow-up and 12% dissatisfied or very dissatisfied. Postoperative SEFAS correlated with age (r = 0.2, p = 0.01) and preoperative SEFAS (r = 0.3, p < 0.001), as did patient satisfaction (r = -0.2; p ≤ 0.03). Postoperative SEFAS and EQ-5D were similar between different diagnoses or prosthetic designs. Preoperative SF-36 was associated with diagnosis (p ≤ 0.03), postoperative SF-36 with age (r = 0.2, p = 0.01) and diagnosis (p < 0.03). Interpretation - We found statistically and clinically significant improvements in patient-reported outcomes following TAR surgery. The postoperative region-specific SEFAS was positively associated with older age. Prosthetic design seemed not to influence patient-reported outcome, whereas diagnosis partly did. Studies with longer follow-up are necessary to establish the long-term outcome of TAR and to elucidate whether short- and mid-term outcomes may predict implant failure.

Can a Three-Component Prosthesis be Used for Conversion of Painful Ankle Arthrodesis to Total Ankle Replacement?

BACKGROUND

In patients with painful ankle arthrodesis, the surgical treatment is challenging, and may include takedown of ankle arthrodesis and conversion to a total ankle replacement (TAR). This procedure is technically demanding given the altered anatomy after arthrodesis. Few studies have evaluated TAR in the setting of prior arthrodesis.

QUESTIONS/PURPOSES

(1) What intraoperative and perioperative complications were observed in patients who underwent conversion of an ankle arthrodesis to a TAR? (2) Was durable fixation achieved at short term, and what was the alignment of the components? (3) What subsequent surgical procedures were performed, including revisions? (4) What improvements were observed in pain, tibiotalar range of motion (ROM), and quality of life?

METHODS

Between January 2007 and December 2014, 18 patients with a painful ankle arthrodesis underwent conversion to TAR at our tertiary referral center. During this period, the indications for conversion of ankle arthrodesis to TAR were tibiotalar nonunion or malunion after attempted arthrodesis in patients who declined revision ankle arthrodesis. The goal of revision surgery was to help patients regain hindfoot mobility and to decrease pain. During the study period, all patients who met indications were treated with a conversion procedure. Of the 18 patients included, 14 were men and four were women. The mean age of the patients was 51 ± 7 years. The mean followup was 54 ± 27 months, with no loss to follow up observed. The initial ankle arthrodesis was performed 6 ± 3.5 years before conversion to TAR. In all patients, the conversion to TAR was performed using a nonconstrained cementless three-component prosthesis. Intraoperative and postoperative complications, revision procedures, and prosthesis component loosening were evaluated. Weightbearing radiographs were used to determine the angular alignment of the tibial and talar components using α/β/γ angles and to analyze the bone-implant interface. Osseointegration was defined as visible trabecular structures at the bone-implant interface without radiolucent lines. The criteria for radiographic loosening was defined as subsidence or migration of prosthesis components and/or a cystic lesion with a diameter at least 2 mm. Clinical assessment included pain evaluation, measurement of ankle ROM, and quality of life.

RESULTS

Two of the 18 patients sustained an intraoperative medial malleolar fracture. In three patients, delayed wound healing was observed. At latest followup, four patients had incomplete osseointegration (posterior quarter of the bone-prosthesis interface on the tibial side). None of the 18 patients had prosthesis loosening. In all patients, both components were neutrally aligned. Two patients had painful arthrofibrosis with reduced ROM, which we treated with an open arthrolysis and exchange of mobile-bearing inlay; one other patient is considering a revision for substantial tibial component medial tilt with collapse of the medial arch. At the latest followup, the mean dorsiflexion and plantar flexion were 8.5° ± 3° and 15° ± 5°, respectively. The mean visual analog scale (VAS) score decreased from 9 ± 0.8 to 1.7 ± 1.6 (p < 0.001). The Short Form Health Survey questionnaire (SF-36) physical and mental outcome scores improved from 34 ± 5 to 74 ± 11 (p < 0.001) and from 49 ± 4 to 75.5 ± 7 (p < 0.001).

CONCLUSIONS

Conversion of an ankle arthrodesis to a TAR is a technically challenging procedure. In this small series, it was associated with frequent complications including arthrofibrosis, and functional outcomes including postoperative ROM were lower than reported for primary TAR. However, pain and function did improve. Further studies are necessary to address long-term clinical and radiographic outcomes in this patient cohort.

LEVEL OF EVIDENCE

Level IV, therapeutic study.