Total ankle arthroplasty in inflammatory joint disease with use of two mobile-bearing designs

Nonunion after medial malleolar osteotomy in total ankle arthroplasties for severe varus deformity: a report of 3 cases

Of the three ankles after total ankle arthroplasty (TAA) with medial malleolar osteotomy for severe varus deformity (talar varus tilt >10°), two failed in varus migration of the tibial component. In these two cases, tibial osteotomy was performed with varus alignment of 5°and 2°, and with medially shifted placement of tibial component, while one ankle showed no migratoin of prostheses after 5 years, even with nonunion. In this case, tibial osteotomy was performed with a valgus alignment of 4°. Internal fixation after medial malleolar osteotomy should be done for severe varus cases. Medially shifted placement of tibial component should be avoided. Fortunately, the failure did not occur in a case of valgus of the distal tibia. Valgus tibial osteotomy might help to reduce the collision of the talus against the medial malleolus.

Outcomes of Total Ankle Replacement with Preoperative Varus Deformity

Historically, coronal plane deformities of greater than 10° to 15° have been deemed contraindications for total ankle replacement (TAR). However, recent studies show satisfactory results in TAR with severe preoperative varus deformity. When correctly applying ancillary procedures, preoperative varus deformity can be structurally corrected, resulting in similar clinical scores to those obtained with "regular TAR." However, complications and revisions appear to increase with increasing deformity. Unfortunately, results of TAR in varus ankles consist of heterogeneous data (eg, with regards to prosthetic brands, bearing-types, duration of follow-up, and ancillary procedures) precluding strict conclusions. This could be solved by an international consensus group.

Navigating the Challenges of Total Ankle Replacement: Deformity Correction and Infection Considerations

In recent years, total ankle replacement (TAR) has gained widespread acceptance as a surgical treatment for end-stage ankle arthritis. This shift is due to notable improvements in implant design, surgical instrumentation, technique, and surgeon expertise, resulting in high levels of patient satisfaction comparable to ankle fusion. Additionally, indications for TAR have expanded to include advanced deformities that were previously considered unsuitable for the procedure, making ankle arthrodesis the only option. Despite these advancements, TAR still carries a higher complication rate compared to other ankle surgeries. The complex anatomy of the ankle, coupled with limited soft tissue, presents significant challenges in managing complications associated with TAR.

Managing Intraoperative Fractures During Total Ankle Replacement

Intraoperative complications during total ankle replacement (TAR) can be devastating. As surgeons' experience with total ankles grow and surgical techniques are refined, intraoperative complications, such as fractures, can still occur. Surgeons must be able to recognize a problem, identify the options to remediate, and then execute a solution readily. Unfortunately, given the heterogeneity of TAR outcome studies, it is difficult to garner the true incidence of complications in the peri-operative period following ankle replacements. The purpose of this review is to focus on perioperative fractures during TAR. Fractures can occur intraoperatively and postoperatively as stress fractures or post-operative trauma.

Total Ankle Replacement Infections: A Systematic Review of the Literature

Periprosthetic infection (PJI) after TAR is a serious complication, often requiring further surgery, including revision arthroplasty, conversion to ankle arthrodesis, or even amputation. This systematic review aims to summarize the current evidence on the management of TAR PJI and provide a comprehensive overview of this topic, especially from an epidemiologic point of view. Three different databases (PubMed, Scopus, and Web of Science) were searched for relevant articles, and further references were obtained by cross-referencing. Seventy-one studies met the inclusion criteria, reporting on cases of TAR PJI. A total of 298 PJIs were retrieved. The mean incidence of PJI was 3.8% (range 0.2-26.1%). Furthermore, 53 (17.8%) were acute PJIs, whereas most of them (156, 52.3%) were late PJIs. Most of the studies were heterogeneous regarding the treatment protocols used, with a two-stage approach performed in most of the cases (107, 35.9%). While the prevalence of ankle PJI remains low, it is potentially one of the most devastating complications of TAR. This review highlights the lack of strong literature regarding TAR infections, thus highlighting a need for multicentric studies with homogeneous data regarding the treatment of ankle PJI to better understand outcomes.

Robotic-assisted foot and ankle surgery: a review of the present status and the future

The surgical application of robotics has increased significantly since its first application in 1985 for a brain biopsy acquisition. Robotic-assisted surgery has been one of the viable options in various surgical areas, and also in orthopaedic surgery. Robotic-assisted orthopaedic surgery has gained popularity as a mean of improving accuracy, reducing complications and achieving better patient satisfaction. Numerous clinical research studies have demonstrated advantages of robotic-assisted orthopaedic surgery, however, most of that researches were about the total knee arthroplasty, total hip arthroplasty and spine surgery. The application of robotic technology in foot and ankle surgery is in a very nascent stage. Furthermore, there has been little research on intraoperative use of robotics in foot and ankle surgery in literature. A review of previous preclinical studies in foot and ankle robotics and clinical research studies in various fields of robot-assisted orthopaedic surgery shows that its potential application and benefits over conventional techniques, such as total ankle arthroplasty, minimally invasive surgery for foot and ankle trauma or other corrective procedure, and intraoperative biomechanical testing. More studies on practical application of robotic technology to surgical procedure in the field of foot and ankle surgery are needed to confirm its clinical usefulness and cost effectiveness.

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.

Effect of diabetes mellitus on the outcomes of total ankle arthroplasty: is controlled diabetes mellitus a risk factor?

BACKGROUND

It is still uncertain whether diabetes mellitus (DM) is a risk factor for poor outcomes and increased complications after total ankle arthroplasty (TAA). The objective of this study was to compare clinical outcomes and complication rates of TAA in patients with and without DM.

METHODS

This study enrolled patients with symptomatic end-stage ankle osteoarthritis with a minimum follow-up period of 24 months after TAA. A total of 252 patients (266 ankles) were classified into two groups according to the presence of DM: (1) DM group (59 patients, 67 ankles) and (2) non-DM group (193 patients, 199 ankles). We defined controlled diabetes as (1) HbA1c level < 7.0%, or (2) fasting glucose level < 130 mg/dL with HbA1c level ≥ 7.0% for hospitalization period. Clinical outcomes data (Ankle Osteoarthritis Scale, American Orthopedic Foot and Ankle Society ankle-hindfoot score, Short Form-36 Physical Component Summary score, and visual analog scale for pain) were compared preoperatively and at the final follow-up between the two groups. Complications following TAA were also compared between the two groups.

RESULTS

All clinical variables had improved in both groups by the final follow-up (mean follow-up = 77.8 months). There was no significant difference in any clinical variable between the two groups at the final follow-up (P > 0.05). Of the 266 ankles, 73 ankles (19 in the DM group, 54 in the non-DM group) developed periprosthetic osteolysis. Although the DM group showed a higher prevalence of aseptic loosening or subsidence, the difference between the two groups was not statistically significant (P = 0.236).

CONCLUSIONS

In the intermediate-term follow-up, TAA in patients with controlled DM showed clinical outcomes and complication rates comparable to patients without DM. Our results suggest that TAA can be done safely in diabetic patients if the DM is controlled in the perioperative period.

LEVEL OF EVIDENCE

Therapeutic Level III.

Risk Factors for Failure of Total Ankle Replacements: A Data Linkage Study Using the National Joint Registry and NHS Digital

BACKGROUND

Despite the increasing numbers of ankle replacements, there remains debate about which patients should undergo an ankle replacement, and there are limited studies analyzing risk factors for failure of an ankle replacement. The primary aim of this study is to analyze the risk factors for failure of total ankle replacements.

METHODS

A data linkage study combining the National Joint Registry (NJR) Data and NHS (National Health Service) Digital data was performed. The primary outcome of failure is defined as the removal or exchange of any components of the implanted device. Kaplan-Meier survival charts were used to illustrate survivorship. Multivariable Cox proportional hazards regression models were fitted to analyze potential risk factors for failures or ankle replacements.

RESULTS

The overall 5-year survival was 90.2% (95% CI 89.2%-91.1%). In multivariable (adjusted) Cox regression models, only age (hazard ratio [HR] 0.96, 95% CI 0.94-0.97), body mass index (BMI; HR 1.03, 95% CI 1.01-1.06), and underlying etiology (HR 0.88, 95% CI 0.80-0.97) were associated with an increased risk of failure.

CONCLUSION

This study demonstrates that younger patients and those with an increased BMI have an increased risk of failure of a primary ankle replacement. We also show that rheumatoid patients have higher survivorship than those with osteoarthritis.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Computed Tomography Derived Patient-specific Instrumentation Total Ankle Arthroplasty Survivorship Outcomes

Computed tomography (CT) derived patient-specific total ankle arthroplasty (TAA) systems have been utilized for improved accuracy and reproducible implant alignment. The purpose of the present study was to report the overall implant survivorship as well as radiographic analysis of patients who underwent primary TAA utilizing CT-derived patient-specific instrumentation. A retrospective review of medical charts and radiographs were performed on patients who had undergone primary TAA at a single institution in the Midwest region from March 2013 to October 2020. Radiographic analysis included preoperative, initial postoperative, and final follow-up coronal and sagittal tibiotalar alignment as well as periprosthetic radiolucency. A total of 96 patients with a mean follow-up of 3 years (range, 0.3-7.3 years) were included. Implant survivorship was found to be 92% at median follow-up of 3 years. A total of 8 cases (8.3%) required revision/reoperation, with 6 (6.3%) of these reoperations directly related for failure of one of the metallic implant components. There was significant improvement in both coronal and sagittal tibiotalar alignment from preoperative to initial postoperative follow-up (p < .001). At latest postoperative follow-up, there were 88% of TAAs that remained in a neutral alignment following surgery. A total of 10 cases were found to have radiolucency at latest follow-up. In conclusion, the use of CT derived patient-specific TAA showed high implant survivorship with significant improvement of sagittal and coronal tibiotalar alignment. With better implant alignment and position, it potentially reduces the risk of early implant failure or implant loosening in long-term follow-up.

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.

Addressing varus and valgus deformity of the ankle: Algorithmic approach to total ankle arthroplasty

Total ankle replacements have become increasingly popular, providing a viable alternative to ankle arthrodesis in patients with end stage ankle arthritis. Continued advancements in implant design have substantially improved long term survival outcomes as well as patient pain relief, range of motion, and quality of life. Surgeons continue to advance the indications for implantation of total ankle replacements in patients with more severe varus and valgus coronal plane deformity. This report of twelve cases demonstrates our algorithmic approach to total ankle arthroplasty in patients with deformity of the foot and ankle. By proposing a clinical algorithm with case examples, we aim to aid clinicians in successfully approaching coronal plane deformities of the foot and ankle when using total ankle replacement to ultimately improve clinical outcomes.

Midterm Outcomes of the INBONETM II Total Ankle Arthroplasty

As the number of total ankle arthroplasties (TAA) performed continues to increase, understanding midterm outcomes can guide both implant selection and preoperative patient counseling. The purpose of this study was to investigate midterm results including the survival rate and reasons for revision for the INBONE^TM II TAA. Patients undergoing a primary TAA with the study implant and minimum of 4.6 years postoperative follow-up were reviewed from a prospectively collected database. The primary outcome was implant survival. Secondary outcomes included coronal plane radiographic alignment, evaluation for cysts and osteolysis, and failure mode when applicable. Patients were eligible for inclusion in this study if they had a minimum of 4.6-year follow-up TAA with the study implant. Eighty-five TAAs in 83 patients were eligible for inclusion; 75 TAA in 73 patients were included in the study. The mean duration of follow up was 6.2 ± 0.9 years (range 4.7-8.1 years). Thirty-six percent of the TAAs had a preoperative coronal plane deformity of at least 10^°, and 12% of the TAAs had at least 20^°. There were 6 (8%) implant failures that occurred at a mean 2.0 ± 1.4 years postoperatively. Eighty-one percent of the TAAs had no reoperation events in the follow-up period. Midterm outcomes at a minimum of 4.6 years postoperatively in patients undergoing a TAA using this implant demonstrates acceptable implant survival, an approximately 20% reoperation rate, and maintenance of coronal plane alignment.

Short-Term Clinical Outcomes Following Total Ankle Arthroplasty Without Concomitant Osteotomy in Ankles with Severe Preoperative Varus Deformity: Comparison to Ankles with Preoperative Neutral Alignment

BACKGROUND

It remains controversial whether satisfactory outcomes can be obtained following total ankle arthroplasty (TAA) without osteotomy in patients with severe varus ankle deformities. This study aimed to examine outcomes following TAA without concomitant osteotomies in patients with severe varus ankle alignment by comparing them with those in patients with neutral alignment.

METHODS

Fifty-one patients (53 ankles; mean age, 71.4 ± 5.6 years) who underwent TAA using the TNK ankle prosthesis were examined (mean follow-up, 36.8 ± 17.8 months). Patients were allocated into groups according to the preoperative talar tilt (TT) angle: the neutral group (preoperative TT angle <10°; n = 37) and the varus group (preoperative TT angle ≥10°; n = 16). Outcome measures, including the Japanese Society for Surgery of the Foot scale, Self-Administered Foot Evaluation Questionnaire, ankle range of motion, and radiographic parameters, were assessed before surgery and at the final follow-up.

RESULTS

Significant improvements were observed in clinical and radiographic outcomes in both groups after surgery. Postoperative Japanese Society for Surgery of the Foot scale and subscale scores of pain and shoes in the Self-Administered Foot Evaluation Questionnaire were not significantly different between the groups, whereas subscale scores of function, social, and health were greater in the varus group than in the neutral group at the final follow-up. Radiographic parameters, including TT angle and tibial axis-medial malleolus (TMM) angle, improved postoperatively and were not significantly different between the neutral (mean TT angle, 0.5 ± 0.7°; mean TMM angle, 16.0 ± 4.6°) and varus (meanTT angle, 0.4 ± 0.7°; meanTMM angle, 17.0 ± 5.3°) groups at the final follow-up. To achieve neutral alignment, adjunctive procedures were required more often in the varus group.

CONCLUSIONS

Outcomes of TAA using the TNK ankle prosthesis were favorable in patients with severe varus ankle and in those with neutral ankle without concomitant osteotomy. Satisfactory outcomes could be achieved in patients with severe varus ankle alignment after TAA without concomitant osteotomy.

Risk factors for total ankle arthroplasty failure: A Dutch Arthroplasty Register study

BACKGROUND

Studies concerning total ankle arthroplasty could be influenced by several forms of bias. Independent national arthroplasty registries represent objective data on survival and patient reported outcomes. The aim of this study was to determine survival and identify risk factors for early failure in a nationwide series of total ankle arthroplasties from the Dutch Arthroplasty Register (LROI).

PATIENTS AND METHODS

Data of 810 patients, who received 836 total ankle arthroplasties between 2014 and 2020 were obtained from the Dutch Arthroplasty Register (LROI) with a median follow-up of 38 months (range 1-84 months). Survival was expressed in Kaplan-Meier analysis and associated hazard ratios for implant failure were determined. Implant failure was defined as the need for revision surgery for any reason or (pan)arthrodesis.

RESULTS

During follow-up, we recorded 39 failures (4.7%) resulting in a implant survival of 95.3% with a median follow-up of 38 months (range 1-84 months). Medial malleolus osteotomy (HR = 2.27), previous surgery (HR = 1.83), previous osteotomy (HR = 2.82) and previous ligament reconstruction (HR = 2.83) all showed potentially clinically meaningful associations with a higher incidence of implant failure, yet only previous OCD treatment (HR = 6.21), BMI (HR = 1.09) and age (HR = 0.71) were statistically significant.

INTERPRETATION

Excellent short-term survival (95.3%) with a median follow-up of 38 months was reported for TAA patients from the Dutch Arthroplasty Register. Patients with a lower age, a higher BMI or who had a prior surgical OCD treatment before TAA surgery appear to have a higher risk for revision after short-term clinical follow-up. Thorough patient selection with emphasis on risk factors associated with early implant failure might be essential to improve TAA survivorship.

Medial malleolar osteotomy for the correction of tibiotalar varus deformity during total ankle arthroplasty: Results in 95 ankles

BACKGROUND

The importance of deformity correction before or during total ankle replacement (TAR) has been recognized for a long time. Our results of TAR, combined with medial malleolar lengthening osteotomy, for the reconstruction of osteoarthritic ankles with varus deformity are hereby reported.

METHODS

All ankles in which a medial malleolar osteotomy was performed during implantation of an ankle prosthesis during the period 1998-2018 were filtered out of our database. Preoperative coronal talar alignment was evaluated by measuring the angle between the tibial shaft and talar dome on the weightbearing mortise ankle radiograph. Patient-reported outcomes were measured with the Foot and Ankle Outcome Score (FAOS) and the Foot and Ankle Ability Measure (FAAM). A Kaplan-Meier survival curve was constructed and the number of revisions per 100 observed component years was calculated for interprosthetic comparison.

RESULTS

A total of 95 TARs were included, consisting of the Alpha Ankle Arthroplasty (n = 22); Buechel-Pappas (n = 14) and the Ceramic Coated Implant Evolution (n = 59) prostheses. The preoperative average talar angle in these ankles was 12.4 degrees varus. In 33% (31/95) corrective procedures, in addition to the medial malleolar osteotomy, were performed. A reoperation rate of 44% (42/95) was found, including 28 revisions (revision rate 29% (4% septic; 25% aseptic) at an average follow-up of 5.9 years, resulting in a survival of 0.69 for the total cohort at 10 years of follow-up. At an average follow-up of 6.6 years the average FAOS scores were: FAOS_symptoms 66, FAOS_pain 73, FAOS_function 78, FAOS_sport 45 and FAOS_{quality of life} 56 respectively. The FAAM_adl score averaged 64.

CONCLUSION

This is the largest cohort of TAR combined with medial malleolar osteotomy to date. A 29% revision rate at 5.9 years of average follow-up compares unfavorably with regular cohort studies and with most other results in varus-deformed ankles. Scores on the FAOS and FAAM are comparable to those obtained in regular cohorts with similar length of follow-up. TAR in varus-deformed ankles necessitating medial malleolar osteotomy has an even higher failure rate than regular TAR. Obtaining a stable prosthesis with a neutrally-aligned hindfoot at the end of the procedure is of paramount importance.

LEVEL OF EVIDENCE

IV.

Long-Term Clinical Outcomes and Implant Survivorship of 151 Total Ankle Arthroplasties Using the HINTEGRA Prosthesis: A Minimum 10-Year Follow-up

BACKGROUND

Few studies have investigated long-term clinical outcomes of a mobile-bearing total ankle arthroplasty (TAA) system. This study analyzed long-term outcomes of TAA using the HINTEGRA prosthesis at a single, non-developer center.

METHODS

Primary TAAs were performed on 213 ankles in 194 patients, and 151 consecutive ankles [71%] in 136 patients with a minimum follow-up of 10 years after the primary TAA were included in this study. Clinical results were assessed using a visual analog scale (VAS) pain score, the American Orthopaedic Foot & Ankle Society (AOFAS) Ankle-Hindfoot Scale score, the Ankle Osteoarthritis Scale (AOS) pain and disability subscores, and ankle range of motion. Prosthesis survivorship, reoperations, and risk factors were also evaluated.

RESULTS

The mean follow-up was 135.5 months (range, 120.0 to 204.0 months). All clinical scores and ankle range of motion improved significantly from preoperatively to 2 years, 4 to 6 years, and ≥10 years after TAA (p < 0.001). A total of 43 ankles (28.5%) required revision procedures, with the most common reason being periprosthetic osteolysis (32 ankles [21.2%]). The overall implant survivorship was 93.5% in Kaplan-Meier survival analysis at the mean follow-up of 11.3 years after the TAA.

CONCLUSIONS

TAA using the HINTEGRA prosthesis with careful follow-up observation and appropriate adjunct procedures for the treatment of end-stage ankle arthritis produced satisfactory clinical results, which were maintained at a follow-up of ≥10 years, and resulted in 93.5% of implant survivorship.

LEVEL OF EVIDENCE

Prognostic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Postoperative Infection Rates After Total Ankle Arthroplasty: A Comparison With and Without the Use of a Surgical Helmet System

Following total joint arthroplasty, surgical site infections (SSI) and periprosthetic joint infections (PJI) are associated with increased patient morbidity and healthcare utilization. Current positive-pressure surgical sterile helmet system (SHS) were developed as a feasible, useful version of the body exhaust system.The use of SHS has not yet been proven to decrease infection rates in the orthopedic literature. The primary purpose of this study is to compare the infection rates between patients who underwent total ankle arthroplasty (TAA) with a surgical team wearing SHS versus without SHS.A retrospective chart review in patients undergoing primary TAA with the surgeon wearing SHS (Group 1) or standard surgical attire (Group 2) was conducted. The primary outcome was postoperative SSI and PJI. The rate of wound complications, revision rates, and associated procedures were also analyzed. We identified 109 patients in Group 1 and 151 patients in Group 2. The rate of SSI was 12.8% in Group 1 and 14.6% in Group 2 (p = .411). The rate of PJI was 0.92% in Group 1 and 2.6% in Group 2 (p = .411). There was no difference in revision rates between the two groups. This study suggests that SHS does not appear to protect against postoperative SSI or PJI after TAA. Conversely, we did not find a higher infection rate compared to standard surgical attire despite recent in-vitro studies suggesting SHS as a source of wound contamination. The utility of SHS does not appear to influence the prevalence of postoperative SSI or PJI.

Malalignment of the total ankle replacement increases peak contact stresses on the bone-implant interface: a finite element analysis

Introduction

Malalignment of the Total Ankle Replacement (TAR) has often been postulated as the main reason for the high incidence of TAR failure. As the ankle joint has a small contact area, stresses are typically high, and malalignment may lead to non-homogeneous stress distributions, including stress peaks that may initiate failure. This study aims to elucidate the effect of TAR malalignment on the contact stresses on the bone-implant interface, thereby gaining more understanding of the potential role of malalignment in TAR failure.

Methods

Finite Element (FE) models of the neutrally aligned as well as malaligned CCI (Ceramic Coated Implant) Evolution TAR implant (Van Straten Medical) were developed. The CCI components were virtually inserted in a generic three-dimensional (3D) reconstruction of the tibia and talus. The tibial and talar TAR components were placed in neutral alignment and in 5° and 10° varus, valgus, anterior and posterior malalignment. Loading conditions of the terminal stance phase of the gait cycle were applied. Peak contact pressure and shear stress at the bone-implant interface were simulated and stress distributions on the bone-implant interface were visualized.

Results

In the neutral position, a peak contact pressure and shear stress of respectively 98.4 MPa and 31.9 MPa were found on the tibial bone-implant interface. For the talar bone-implant interface, this was respectively 68.2 MPa and 39.0 MPa. TAR malalignment increases peak contact pressure and shear stress on the bone-implant interface. The highest peak contact pressure of 177 MPa was found for the 10° valgus malaligned tibial component, and the highest shear stress of 98.5 MPa was found for the 10° posterior malaligned talar model. High contact stresses were mainly located at the edges of the bone-implant interface and the fixation pegs of the talar component.

Conclusions

The current study demonstrates that TAR malalignment leads to increased peak stresses. High peak stresses could contribute to bone damage and subsequently reduced implant fixation, micromotion, and loosening. Further research is needed to investigate the relationship between increased contact stresses at the bone-implant interface and TAR failure.

CT Scan Assessment and Functional Outcome of Periprosthetic Bone Grafting After Total Ankle Arthroplasty at Medium-term Follow-up

BACKGROUND

Periprosthetic cysts can occur in up to 95% of total ankle arthroplasties (TAA) and have been correlated with implant failure. The aim of this study was to determine the clinical and radiologic outcomes, using computed tomographic (CT) scan, after periprosthetic cyst bone grafting and assess for the minimum cyst size that should be grafted.

METHODS

A retrospective review was performed of all TAA procedures performed between 2007 and 2014 (n=93). A CT scan was done to assess cyst size and operative planning. Eight patients with 9 periprosthetic cysts larger than 1.75 cm³ were grafted and specimens sent for histology. The mean time to bone grafting was 7.3 (3.8-9.5) years. Functional outcome was assessed using the American Orthopaedic Foot & Ankle Society ankle score, visual analog scale, and Self-reported Foot and Ankle Score. A CT scan was performed at follow-up to assess graft incorporation and cyst size progression. The mean time to CT scan post grafting was 3.0 (0.7-4.7) years.

RESULTS

There was no implant malalignment identified and no differences in the pre- and postoperative functional scores. Preoperatively cysts had a mean volume of 8.16 (2.04-14.03) cm³. The mean percentage incorporation was 89% (69%-100%). Eight of the grafted cysts were considered successful on CT, with the ninth having 69% incorporation. Five cysts were not grafted, as they were below 1.75 cm³, and remained the same size or had minimal enlargement.

CONCLUSION

The satisfactory results in this small cohort suggests that prophylactic bone grafting may extend implant survival. We recommend that periprosthetic cysts greater than 1.75 cm³ be prophylactically bone grafted, and that cysts smaller than 1.75 cm³ be monitored for progression in size.

LEVEL OF EVIDENCE

Level IV, Case Series.

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.

The INFINITY Total Ankle Prosthesis: Outcomes at Short-Term Follow-up

BACKGROUND

The INFINITY total ankle prothesis remains the most widely used fourth-generation total ankle arthroplasty (TAA) system in the United States. The purpose of the present study was to assess radiographic outcomes for INFINITY at short-term follow-up.

METHODS

All patients who underwent primary TAA with INFINITY between August 2015 and June 2018 at a single institution and who were at least 1 year postoperative were included. A total of 55 ankles with a mean follow up 22 months (range, 12-43 months) met the criteria. Weightbearing radiographs were assessed using coronal and sagittal alignment parameters preoperatively, at 6 to 8 weeks postoperatively, and at the most recent follow-up. Medical records and charts were reviewed and revisions, reoperations, and complications were classified according to the criteria established by Vander Griend et al and Glazebrook at el, respectively.

RESULTS

Overall, INFINITY survivorship was 98.2%. Coronal and sagittal tibiotalar alignment improved after surgery (P < .001, P = .09, respectively), and was maintained during the latest follow-up (P = .62, P = .47, respectively). Only 1 ankle (1.8%) required early revision; while 5 (9.1%) indicated non-implant-related revision; 85.5% required no reoperation. In nineteen ankles (34.5%), postoperative periprosthetic lucency was observed; most were not progressive (17 ankles, 89.5%). Twelve complications (3 high grade, 3 intermediate, and 6 low grade) in 11 ankles (20%) were recorded according to the Glazebrook classification system.

CONCLUSION

INFINITY survivorship was 98.2% at a mean of 1.8 years of follow-up, and only 1 ankle required prosthetic revision. Additional studies with longer follow-up are warranted for fourth-generation TAA prostheses.

LEVELS OF EVIDENCE

Level IV: Case series.

The Impact of Coronal Plane Deformity on Ankle Arthrodesis and Arthroplasty

BACKGROUND

Ankle coronal plane deformity represents a complex 3-dimensional problem, and comparative data are lacking to guide treatment recommendations for optimal treatment of end-stage ankle arthritis with concomitant coronal plane deformity.

METHODS

In total, 224 patients treated for end-stage ankle arthritis were enrolled in an observational trial. Of 112 patients followed more than 2 years, 48 patients (19 arthrodesis, 29 arthroplasty) had coronal plane deformity and were compared to 64 patients without coronal plane deformity (18 arthrodesis, 46 arthroplasty) defined as greater than 10 degrees of varus or valgus. The arthroplasty implants used had different internal constraints to intracomponent coronal plane tilting. Patients completed Musculoskeletal Functional Assessment (MFA) and SF-36 preoperatively and at 3, 6, 12, 24, and 36 months postoperatively. Measures included change in SF-36 and MFA, as well as compared reoperation rates and pain scales.

RESULTS

For the groups with coronal plane ankle deformity, the median for the arthrodesis group was 19.0 degrees and the median for the arthroplasty group was 16.9 degrees. In the deformity cohort during the follow-up period, we had 7 major reoperations: 2 in the arthrodesis group and 5 in the arthroplasty group, all with the less constrained implant design. MFA, vitality, and social function of the SF-36 improved for all groups. Patients without preoperative deformities had greater improvement with fusion or replacement at both 2 and 3 years. There was no difference in improvement between those patients with coronal deformity who received arthroplasty vs arthrodesis.

CONCLUSION

Patients with and without coronal plane deformity may benefit from ankle arthroplasty and arthrodesis, although greater improvements may be expected in those without preoperative deformity. In this study, at final follow-up of 3 years, overall we found no meaningful difference in patient-reported outcomes between the patients with preoperative coronal plane deformities whether they had a fusion or a replacement as treatment for end-stage ankle arthritis.

LEVEL OF EVIDENCE

Level II, comparative study.

Relationship between ankle varus moment during gait and radiographic measurements in patients with medial ankle osteoarthritis

Background

Kinetic data obtained during gait can be used to clarify the biomechanical pathogenesis of osteoarthritis of the lower extremity. This study aimed to investigate the difference in ankle varus moment between the varus angulation and medial translation types of medial ankle osteoarthritis, and to identify the radiographic measurements associated with ankle varus moment.

Methods

Twenty-four consecutive patients [mean age 65.8 (SD) 8.0 years; 9 men and 15 women] with medial ankle osteoarthritis were included. Fourteen and 10 patients had the varus angulation (tibiotalar tilt angle≥3 degrees) and medial translation (tibiotalar tilt angle<3 degrees) types, respectively. All patients underwent three-dimensional gait analysis, and the maximum varus moment of the ankle was recorded. Radiographic measurement included tibial plafond inclination, tibiotalar tilt angle, talar dome inclination, and lateral talo-first metatarsal angle. Comparison between the two types of medial ankle osteoarthritis and the relationship between the maximum ankle varus moment and radiographic measurements were analyzed.

Results

The mean tibial plafond inclination, tibiotalar tilt angle, talar dome inclination, lateral talo-first metatarsal angle, and maximum ankle varus moment were 6.4 degrees (SD 3.3 degrees), 5.0 degrees (SD 4.6 degrees), 11.4 degrees (SD 5.2 degrees), -6.5 degrees (SD 11.7 degrees), and 0.185 (SD 0.082) Nm/kg, respectively. The varus angulation type showed a greater maximum ankle varus moment than the medial translation type (p = .005). The lateral talo-first metatarsal angle was significantly associated with the maximum ankle varus moment (p = .041) in the multiple regression analysis.

Conclusion

The varus angulation type of medial ankle osteoarthritis is considered to be more imbalanced biomechanically than the medial displacement type. The lateral talo-first metatarsal angle, being significantly associated with the ankle varus moment, should be considered for correction during motion-preserving surgeries for medial ankle osteoarthritis to restore the biomechanical balance of the ankle.

The effect of ankle osteoarthritis and total ankle arthroplasty on center of pressure position

Total ankle arthroplasty (TAA) is a common surgical approach for patients with end-stage ankle osteoarthritis (OA). However, very little is known about the path of the center of pressure (COP) of the foot, and thus important aspects of load transfer, muscle mechanical advantage, and balance, in patients before or after surgery. The objective of this study was to trace the pathway of the COP under the foot in patients with symptomatic ankle OA, comparing asymmetry between affected and unaffected limbs. From force plate data, proximodistal and mediolateral positions of the COP beneath the foot were calculated and compared for the affected and unaffected foot in patients with unilateral ankle OA (N = 93) before and after TAA. Gender and age at surgery had little or no effect in this study. Patients with ankle OA had minimal COP position asymmetry before surgery, and this asymmetry was reduced following surgery. Before surgery, patients had a slower walking speed and a shorter path of the COP which began relatively distal to the heel and ended relatively proximal to the hallux. TAA increased the proximodistal distance the COP traveled under both the unaffected and affected foot, a pattern that was maintained for over 2-year postsurgery. TAA allows patients with ankle OA to maintain a longer COP path than they had before surgery on both sides that is closer to that reported for unaffected individuals, extending effectively from the heel to the hallux, potentially improving pedal mechanics.

Treatment of Severe Ankle and Hindfoot Deformity: Technique Using Femoral Head Allograft for Tibiotalocalcaneal Fusion Using a Cup-and-Cone Reamer

Limb shortening due to structural bone loss in tibiotalocalcaneal arthrodesis is a concern that can negatively impact the patient's gait and weight-bearing. To aid in preventing the risk of limb shortening, the use of a femoral head allograft and intramedullary nail in tibiotalocalcaneal arthrodesis has been shown to successfully preserve limb length in patients with structural bone deficits. We present our technique using a femoral head allograft with a cup-and-cone reamer for the treatment of severe ankle and hindfoot deformity.

Long-term follow-up of Bologna-Oxford (BOX) total ankle arthroplasty

PURPOSE

The purpose of this retrospective study was to evaluate the long-term results with a minimum of ten years follow-up of primary Bologna-Oxford (BOX) TAA.

METHODS

Between December 2004 and December 2009, 80 patients (82 ankles) underwent a primary BOX TAA performed by a single senior surgeon, expert in foot and ankle surgery. Pain and functional outcomes were analysed using Visual Analogue Scale (VAS) for pain, American Orthopaedic Foot & Ankle Society (AOFAS) scoring system, Foot Functional Index Disability and Pain (FFI-Disability, FFI-Pain) score for comparative analysis.

RESULTS

A total of 52 patients (54 implants) in a cohort of 80 (82 implants) were examined at a minimum ten years follow-up. Twenty implants out of 54 underwent implant failure (37 %) and 34 patients were enrolled in the present study. The mean VAS for pain decreased significantly from 8.5 ± 1.2 to 2.9 ± 2.2 (p<0.01) and the mean AFOAS score changed from 28.6 ± 11.8 pre-operatively to 72.7 ± 16.9 (p<0.01) at last follow-up. Ninety-seven percent was satisfied with a mean FFI-Disability score that improved from 77.6 ± 19.3 to 26.7 ± 25.4 (p<0.01) and FFI-Pain score that decreased from 76.2 ± 14.2 to 31.4 ± 25.6 (p<0.01). We calculated post-operative alignment using alpha, beta and gamma angles with no difference at long-term follow-up. The survival rate of the implant was 66% at ten years of follow-up.

CONCLUSIONS

Our data suggest that BOX TAA is an implant with a good patient satisfaction rate at long-term follow-up; therefore, it is a valid option to increase the quality of life in subjects with end-stage osteoarthritis; however, long-term survivorship is unsatisfactory when compared to modern knee and hip implant.

The 50 most cited articles in ankle surgery

This paper aims to establish a ranking of the 50 most cited research articles pertaining to ankle surgery in the field of orthopaedics. In addition, the demographic features such as the date of publications, location of primary author and country of the publisher were all analysed. Studies similar to these have been completed in other subspecialties, however we were not able to find studies relevant to ankle surgery. The Web of Science Cor Collection Database was utilised to identify the target articles. The most cited article was cited 394 times and the least was cited 120 times, and the majority of articles were published in the United States of America. This research will benefit the scientific community in identifying popular research topics, identifying lacking fields and identifying key hubs in the field of ankle surgery.

Sagittal Tibiotalar Alignment May Not Affect Functional Outcomes in Fixed-Bearing Total Ankle Replacement: A Retrospective Cohort Study

BACKGROUND

In total ankle replacement (TAR), correct positioning of the implant is crucial. Malposition of the components may increase contact pressures and diminish prosthesis survival. The effect of sagittal tibiotalar alignment on functional outcomes after fixed-bearing TAR remains unclear, however, and no studies have compared fixed-bearing implants with respect to the anteroposterior (AP) position of the talar component.

QUESTIONS/PURPOSE

The purposes of this study were (1) to evaluate the effect of sagittal tibiotalar alignment on functional outcomes in fixed-bearing TAR and (2) to compare post-operative sagittal tibiotalar alignment in two types of fixed-bearing implants.

METHODS

In a retrospective analysis of 71 primary TARs performed at a single center, we studied the INBONE™ II Total Ankle System and the Salto Talaris^® Ankle. Radiographic measurements of the tibial axis-talus (T-T) ratio and the AP offset ratio were performed before and after surgery, respectively, and we evaluated Foot and Ankle Outcome Scores (FAOSs) and the 12-item Short Form Health Survey (SF-12) mental component summary (MCS) and physical component summary (PCS) scales pre-operatively and at 2 years after surgery. The Pearson correlation and independent-samples t test were used to evaluate differences in FAOSs, SF-12 MCS scores, and SF-12 PCS scores regarding post-operative sagittal alignment.

RESULTS

Post-operative sagittal tibiotalar alignment was neutral in 39 ankles and anterior in 32 ankles. We observed no significant between-group differences in clinical outcome scores. Patients with a Salto Talaris Ankle prosthesis had a greater AP offset ratio (0.12) than patients with an INBONE II implant (0.05). However, the greater translation did not correlate with outcome scores.

CONCLUSION

At the 2-year follow-up, no correlation between the post-operative AP offset ratio and functional outcome scores was observed between the two fixed-bearing-implant groups. Further studies with longer follow-up are needed to determine whether the difference in sagittal alignment has an effect on functional outcomes in the long term.

Current practices in haemophilic patients undergoing orthopedic surgery - a systematic review

Haemophilia is an inherited disease that requires a different approach in order to evaluate, monitor and treat patients. Despite the great advances in therapeutic agents that have emerged, reports on the impact of monitoring outcomes on treatment decisions are rarely presented. Haemophilia A and haemophilia B are inherited bleeding disorders caused by deficiencies in blood clotting factor proteins. A systematic review was performed to identify literature reports on the current practices in haemophilic patients undergoing orthopedic surgery. The best therapy for haemophilic patients consists in performing primary prophylaxis to prevent joint bleeding and other complications. Besides the primary prophylaxis, thromboprophylaxis is used to prevent venous thrombosis in patients with hemophilia who undergo surgical orthopedic procedures. Further research is needed to better manage the pharmacologic approaches in haemophilic patients undergoing orthopedic surgery. Although patients with haemophilia present low risk for thromboembolic complications, such events have been reported in surgical procedures. The recommendations in patients with haemophilia are considerably variable in the current guidelines and clinical practice. The best therapy for haemophilic patients consists in performing primary prophylaxis to prevent joint bleeding and other complications.

Arthrodesis of the Foot or Ankle in Adult Patients with Congenital Clubfoot

Background

Although clubfoot that was corrected in childhood rarely recurs in adulthood, persistent deformities or arthritic pain may require further treatment during adulthood. Little evidence exists on the operative procedures utilized in adult clubfoot patients, who were previously treated for congenital clubfoot in childhood, for residual or recurrent deformity or pain.

Objective

The objective of this study is to characterize the types and frequencies of procedures utilized in adult clubfoot patients, who were previously treated for congenital clubfoot in childhood.

Methods

A two-pronged approach was employed to describe the operative procedures used in adult clubfoot patients. First, a literature review of all reported cases of operative treatment in adult clubfoot patients who were previously treated in childhood was performed. Second, an analysis of the operative treatments used in adult patients with a diagnosis of congenital clubfoot was conducted using a large, administrative claims database.

Results

In the literature review, arthrodesis was the most cited operative treatment and reported in four out of the eight studies included. Osteotomies were also reported in the literature. In the database analysis, 94 hindfoot arthrodesis procedures were identified in 73 patients, out of 1,198 adult patients in the database with a diagnosis of congenital clubfoot. Sixty-two patients out of 1,198 adult clubfoot patients received osteotomies. An insufficient number of total ankle arthroplasties were reported for further analysis.

Conclusions

Operative treatment in adult clubfoot patients who were treated for congenital clubfoot in childhood includes hindfoot arthrodesis and osteotomy procedures. Total ankle arthroplasty has not been reported in the literature for these patients.

The Salto total ankle arthroplasty - Clinical and radiological outcomes at five years

BACKGROUND

Modern designs of total ankle arthroplasty (TAA) have the potential to treat symptomatic ankle OA without adversely affecting ankle biomechanics. We present the mid-term results of a modern, mobile-bearing TAA design.

METHODS

TAA was performed in 50 consecutive patients (55 ankles) in an independent, prospective, single-centre series. Implant survival, patient-reported outcome measures (PROMs) and radiographic outcomes are presented at a mean of five years (range 2-10.5years).

RESULTS

A total of three patients (four ankles) died and two (two ankles) were lost to follow-up. Three TAAs were revised for aseptic loosening (in two cases) or infection. Two further patients underwent reoperations, one for arthroscopic debridement of anterolateral synovitis and one for grafting of an asymptomatic tibial cyst. With all-cause revision as an endpoint, implant survival was 93.3% at five to ten years (95% CI 80.5%-97.8%). If reoperations are included this falls to 90.2% (95% CI 75.6%-96.3%) at five years. No other patient demonstrated radiographic evidence of loosening or subsidence. PROMs and satisfaction were excellent at latest follow-up.

CONCLUSION

At five years, the outcomes for this design of TAA in this series were excellent, and were similar to those of previously published series from the designer centre.

What Is the Definition of Acute and Chronic Periprosthetic Joint Infection (PJI) of Total Ankle Arthroplasty (TAA)?

RECOMMENDATION

There is a paucity of data for defining acute or chronic periprosthetic joint infection (PJI) following total ankle arthroplasty (TAA) in the literature. Any discussion of PJI after ankle replacement is entirely reliant on the literature surrounding knee and hip arthroplasty.

LEVEL OF EVIDENCE

Consensus.

DELEGATE VOTE

Agree: 100%, Disagree: 0%, Abstain: 0% (Unanimous, Strongest Consensus).

Two-Stage Varus Correction

Coronal plane deformity following total ankle arthroplasty has been associated with poor clinical outcomes and early prosthesis failure. Neutral mechanical alignment and prosthetic joint stability must be achieved through meticulous surgical planning and precise technical execution. Cavovarus foot deformity and varus malalignment of the lower extremity is reviewed, with particular emphasis as it relates to total ankle arthroplasty. Correction of varus malalignment may be performed at the time of total ankle arthroplasty or as a 2-stage procedure. Surgeon experience, revision total ankle arthroplasty, and subtalar arthrodesis should be considerations when contemplating 2-stage varus correction.

Long-term Follow-up Results of Buechel-Pappas Ankle Arthroplasty

BACKGROUND

Total ankle replacement (TAR) is gaining popularity as a treatment option for ankle osteoarthritis. Long-term implant survival is a critical outcome to determine the success of the TAR implant. The Buechel-Pappas (BP) implant is a second-generation mobile bearing implant. The aim of this study was to analyze the BP implant survivorship at 10-year follow-up, make a subanalysis between patient groups, and evaluate long-term functional outcomes.

METHODS

Data of 86 patients who received 101 BP implants between 1993 and 2010 were obtained from a prospectively documented database. Subanalyses were done for patients diagnosed with inflammatory joint disease and noninflammatory joint disease, and patients with preoperative tibiotalar neutral and nonneutral alignment. A Kaplan-Meier curve was used for survival analysis. Long-term functional outcomes were assessed with the following patient-reported outcome measures: Foot and Ankle Outcome Score (FAOS), Foot and Ankle Ability Measure (FAAM), Short Form-36 (SF-36) Stand Version 2.0 Health Survey and 3 anchor questions.

RESULTS

The survival rate of the BP implant at 10 years was 86% (95% confidence interval, 78%-93%). A total of 31 patients (36%) required 55 reoperations, and in 13 patients (15%) a revision procedure was performed. In this series, no significant difference in 10-year survival rate was found between neither the inflammatory joint disease and noninflammatory joint disease group ( P = .47), nor the tibiotalar neutral and nonneutral alignment group ( P = .16). At a mean follow-up of 16.8 years for 21 patients, the mean FAOS activities of daily living (ADL) and FAAM ADL subscale scores were 75/100 and 56/100 points. The mean physical component summary (PCS) and mental component summary (MCS) of the SF-36 were 34/100 and 51/100 points, respectively.

CONCLUSION

A survival rate of 86% was found at 10-year follow-up for the Buechel-Pappas implant. Our series demonstrated no significant difference in 10-year survival rates between the 2 patient subgroups. Long-term results of the various functional outcomes varied between poor and moderate.

LEVEL OF EVIDENCE

Level II, prospective cohort study.

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

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

Ankle Arthrodesis using Ilizarov Ring Fixator: A Primary or Salvage Procedure? An Analysis of Twenty Cases

Introduction: Ankle arthrodesis using the Ilizarov technique provides high union rate with the added benefits of early weight-bearing, and the unique advantage of its ability to promote regeneration of soft tissue around the bone, including skin, muscle and neuro-vascular structures, and its versatility to allow correction of the position of the foot by adjusting the frame post-operatively as needed. We describe our experience with this technique and the functional outcomes in our patients.

Materials and Methods: This retrospective study was conducted in 20 ankle fusion cases using the Ilizarov method between the years 2007 and 2017. We defined success in treatment by loss of preoperative symptoms and radiological union on plain radiographs of the ankle.

Results: Fusion was achieved in all patients (100%). Immediate post-operative ambulation was with full weight bearing (FWB) in 16 (83%) of the participants and non-weight bearing (NWB) in 3 patients (17%). Post-procedure 11 patients (67%) of the participants who were full weight bearing required some form of support for walking for 2-3 weeks. Post-operatively three patients had pin tract infection requiring intravenous antibiotics. Radiological union took range of 6-12 weeks, mean union time was 8 weeks. Only one patient required bone grafting due to bone loss. Average follow-up period was 10-45 months.

Conclusion: The Ilizarov technique has a high union rate and leads to general favourable clinical outcome and may be considered for any ankle arthrodesis but is especially useful in complex cases such as for revisions, soft-tissue compromise, infection and in patients with risk for non-union. Early weight bearing is an extra benefit.

Following the correction of varus deformity of the knee through total knee arthroplasty, significant compensatory changes occur not only at the ankle and subtalar joint, but also at the foot

PURPOSE

This study aimed to assess radiological changes of the ankle joint, subtalar joint and foot following the correction of varus deformity of the knee with total knee arthroplasty (TKA). It was hypothesized that following the correction of varus deformity by TKA, compensatory reactions would occur at the subtalar joint in accordance with the extent of the correction.

METHODS

For this prospective study, 375 knees of patients who underwent TKA between 2011 and 2012 were enrolled. The varus angle of the knee, talar tilt of the ankle joint (TT), ground-talar dome angle of the foot (GD), anterior surface angle of the distal tibia and lateral surface angle of the distal tibia, heel alignment ratio (HR), heel alignment angle (HA), and heel alignment distance (HD) were measured on radiographs obtained pre-operatively and at post-operative 6 months.

RESULTS

The mean correction angle in varus deformity of the knee was 10.8 ± 4.1°. TT and GD changed significantly from 0.4 ± 1.9° and 6.5 ± 3.1° pre-operatively to 0.1 ± 1.8° and 0.2 ± 2.1°, respectively (p = 0.007, p < 0.001). No correlation was found between the preop-postop variance in mechanical axis of the lower extremity (MA) and TT, but there was a strong correlation between the preop-postop variance in MA and GD (r = 0.701). HR, HA and HD also changed significantly post-operatively, and the preop-postop variance in MA showed correlations with the preop-postop variances in HR, HA and HD (r = 0.206, - 0.348, and - 0.418). TT and the three indicators of hindfoot alignment all shifted to varus whereas GD was oriented in valgus.

CONCLUSION

Following the correction of varus deformity of the knee through TKA, significant compensatory changes occurred not only at the ankle and subtalar joints, but also at the foot. The findings of this study are useful in predicting the orientation of changes in the ankle and subtalar joints and the foot following TKA, and in determining the sequence of surgery when both the ankle and knee have a problem. In other words, changes in the parts of the lower extremity below the ankle joint following the correction of varus deformity of the knee must be considered when TKA is planned and performed. Patients who have problems at the ankle, subtalar, and foot joints in addition to varus deformity of the knee are recommended to undergo knee joint correction first.

LEVEL OF EVIDENCE

II.

Patient-Related Risk Factors for Periprosthetic Ankle Joint Infection: An Analysis of 6977 Total Ankle Arthroplasties

Periprosthetic joint infection (PJI) after total ankle arthroplasty (TAA) is a devastating complication that often results in explantation to resolve the infection. The purpose of the present investigation was to determine the patient-related risk factors for PJI after TAA. A national insurance database was queried for patients undergoing TAA using the Current Procedural Terminology and International Classification of Diseases, ninth revision, procedure codes from 2005 to 2012. Patients undergoing TAA with concomitant fusion procedures or more complex forefoot procedures were excluded. PJI within 6 months was then assessed using the International Classification of Diseases, ninth revision, codes for diagnosis or treatment of postoperative PJI. Multivariate binomial logistic regression analysis was performed to evaluate the patient-related risk factors for PJI. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for each risk factor, with p < .05 considered statistically significant. A total of 6977 patients were included in the present study. Of these 6977 patients, 294 (4%) had a diagnosis of, or had undergone a procedure for, PJI. The independent risk factors for PJI included age <65 years (OR 1.44; p = .036), body mass index <19 kg/m² (OR 3.35; p = .013), body mass index >30 kg/m² (OR 1.49; p = .034), tobacco use (OR 1.59; p = .002), diabetes mellitus (OR 1.36; p = .017), inflammatory arthritis (OR 2.38; p < .0001), peripheral vascular disease (OR 1.64; p < .0001), chronic lung disease (OR 1.37; p = .022), and hypothyroidism (OR 1.32; p = .022). The independent patient-related risk factors identified in the present study should help guide physicians and patients considering elective TAA and develop risk stratification algorithms that could decrease the risk of deep, postoperative infection.

The effect of patient age and diagnosis on the 5-year outcomes of mobile-bearing total ankle replacement

Total Ankle Replacement is an established technique for the management of end-stage ankle arthritis. However, there are few studies focussing on patient-reported outcomes in the medium and long term related to age or arthritis type. We compared demographic data and patient-reported outcomes preoperatively and at five years postoperatively for patients who underwent total ankle replacement with the aim of establishing whether differences exist in outcome depending on patient age or diagnosis. The Foot and Ankle Score (FAOS) and 36-item Short-Form (SF-36) Health Survey were analysed by diagnosis (osteoarthritis, rheumatoid arthritis, post-traumatic arthritis) and age (under or over 60 years). At 5 years, the post-traumatic arthritis group had a significantly higher composite score than the osteoarthritis (p<0.0001) or rheumatoid arthritis groups (p<0.0001). Only the post-traumatic arthritis group experienced a significant increase in composite SF-36 score from baseline (p<0.0001). There was a significant improvement from pre-operatively to 5 years in all three domains of the FAOS and in total scores in both groups (over 60 p<0.0001; 60 and under p=0.0002). There was a significant improvement in composite SF-36 score from pre-operative to 5 years in the patients 60 years or younger at the time of surgery (p=0.0006), but not for the patients over 60. Three patients have been revised (4%), at a mean of 4.8 years following surgery with one patient awaiting revision.

Ankle arthroplasty: A review and summary of results from joint registries and recent studies

Total ankle arthroplasty offers a reasonable alternative to ankle arthrodesis in carefully selected patients.

It is debatable whether rheumatoid arthritis patients have better outcomes compared with those who have ankle arthroplasty for either primary osteoarthritis or post-traumatic arthritis.

Aseptic loosening and infection are the most common complications requiring revision.

It is worth noting that some of the best survival rates are seen in the surgeon-designer case series.

The uncemented mobile or fixed bearing prostheses have better outcomes compared with their older counterparts.

There is no convincing evidence to suggest superiority of one design over another among the currently available prostheses.

Ankle arthroplasty surgery has a steep learning curve; the prosthesis choice should be driven by the surgeon’s training and experience.

Cite this article: EFORT Open Rev 2018;3:391-397. DOI: 10.1302/2058-5241.3.170029

Treatment of Ankle Osteoarthritis with Total Ankle Replacement Through a Lateral Transfibular Approach

Total ankle replacement (TAR) is a valid option for the treatment of ankle osteoarthritis. The traditional surgical approach for TAR is the anterior approach. Recently, the lateral transfibular approach to the ankle has gained popularity since a new TAR implant was designed to be performed via this approach that results in an ideal visualization of the center of rotation of the ankle and curved resections that allow for sparing bone cuts. The aim of the present paper is to present our preoperative, operative, and postoperative protocols for the treatment of the osteoarthritis of the ankle with TAR via lateral approach. We present our preoperative clinical and radiographic protocol. In addition, we describe our surgical technique with some technical tips. Finally, we report our follow-up schedule that includes the collection of clinical, functional, and radiographic data. The results of this procedure are encouraging: TAR through a lateral transfibular approach provides reliable pain relief and improvements in functional outcomes in patients with ankle osteoarthritis.

Finite element analysis of biomechanical effects of total ankle arthroplasty on the foot

Background

Total ankle arthroplasty is gaining popularity as an alternation to ankle arthrodesis for end-stage ankle arthritis. Owing to the complex anatomical characteristics of the ankle joint, total ankle arthroplasty has higher failure rates. Biomechanical exploration of the effects of total ankle arthroplasty on the foot and ankle is imperative for the precaution of postoperative complications. The objectives of this study are (1) to investigate the biomechanical differences of the foot and ankle between the foot with total ankle arthroplasty and the intact foot and (2) to investigate the performance of the three-component ankle prosthesis.

Methods

To understand the loading environment of the inner foot, comprehensive finite element models of an intact foot and a foot with total ankle arthroplasty were developed to simulate the stance phase of gait. Motion analysis on the model subject was conducted to obtain the boundary and loading conditions. The model was validated through comparison of plantar pressure and joint contact pressure between computational prediction and experimental measurement. A pressure mapping system was used to measure the plantar pressure during balanced standing and walking in the motion analysis experiment, and joint contact pressure at the talonavicular joint was measured in a cadaver foot.

Results

Plantar pressure, stress distribution in bones and implants and joint contact loading in the two models were compared, and motion of the prosthesis was analysed. Compared with the intact foot model, averaged contact pressure at the medial cuneonavicular joint increased by 67.4% at the second-peak instant. The maximum stress in the metatarsal bones increased by 19.8% and 31.3% at the mid-stance and second-peak instants, respectively. Force that was transmitted in three medial columns was 0.33, 0.53 and 1.15 times of body weight, respectively, at the first-peak, mid-stance and second-peak instants. The range of motion of the prosthetic ankle was constrained in the frontal plane. The lateral side of the prosthesis sustained higher loading than the medial side.

Conclusion

Total ankle arthroplasty resulted in great increase of contact pressure at the medial cuneonavicular joint, making it sustain the highest contact pressure among all joints in the foot. The motion of the prosthesis was constrained in the frontal plane, and asymmetric loading was distributed in the bearing component of the ankle prosthesis in the mediolateral direction.

The translational potential of this article

Biomechanical variations resulted from total ankle arthroplasty may contribute to negative postoperative outcomes. The exploration of the biomechanical performance in this study might benefit the surgeons in the determination of surgical protocols to avoid complications. The analysis of the performance of the ankle prosthesis could enhance the knowledge of prosthetic design.

Total Ankle Arthroplasty for Rheumatoid Arthritis in Japanese Patients: A Retrospective Study of Intermediate to Long-Term Follow-up

Background:

Outcomes after total ankle arthroplasty (TAA) combined with additive techniques (augmentation of bone strength, control of soft-tissue balance, adjustment of the loading axis) for the treatment of rheumatoid arthritis were evaluated after intermediate to long-term follow-up. The influences of biologic treatment on the outcomes after TAA were also evaluated.

Methods:

We performed a retrospective observational study involving 50 ankles (44 patients) that underwent TAA for the treatment of rheumatoid arthritis. The mean duration of follow-up was 7.1 years. Clinical outcomes were evaluated with use of the Japanese Society for Surgery of the Foot (JSSF) scale score and a postoperative self-administered foot-evaluation questionnaire (SAFE-Q). Radiographic findings were evaluated as well. These parameters also were compared between patients managed with and without biologic treatment.

Results:

This procedure significantly improved the clinical scores of the JSSF rheumatoid arthritis foot and ankle scale (p < 0.0001). Forty-eight of the 50 ankles had no revision TAA surgery. Subsidence of the talar component was seen in 8 ankles (6 in the biologic treatment group and 2 in the non-biologic treatment group); 2 of these ankles (both in the biologic treatment group) underwent revision TAA. The social functioning score of the SAFE-Q scale at the time of the latest follow-up was significantly higher in the biologic treatment group (p = 0.0079). The dosage of prednisolone (p = 0.0003), rate of usage of prednisolone (p = 0.0001), and disease-activity score (p < 0.01) at the time of the latest follow-up were all significantly lower in the biologic treatment group.

Conclusions:

TAA is recommended for the treatment of rheumatoid arthritis if disease control, augmentation of bone strength, control of soft-tissue balance, and adjustment of the loading axis are taken into account. The prevention of talar component subsidence remains a challenge in patients with the combination of subtalar fusion, rheumatoid arthritis, and higher social activity levels.

Level of Evidence:

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Knee and Ankle Arthroplasty in Hemophilia

Today, major surgical procedures can be safely performed in hemophilic patients with chronic arthropathy, using available factor concentrates. In this setting, total knee replacement is considered the "gold standard", while the use of total ankle replacement is still debated. Indeed, the unsatisfactory results obtained with the previous available design of implants did not raise enthusiasm as knee or hip replacement. Recently, the introduction of new implant designs and better reported outcomes have renewed the interest in total ankle replacement in people with hemophilia. In this review, the role of replacement surgery in the treatment of chronic hemophilic arthropathy will be described.

Comparison of the outcome of total ankle arthroplasty for osteoarthritis with moderate and severe varus malalignment and that with neutral alignment

AIMS

The purpose of this study was to compare the clinical and radiographic outcomes of total ankle arthroplasty (TAA) in patients with pre-operatively moderate and severe arthritic varus ankles to those achieved for patients with neutral ankles.

PATIENTS AND METHODS

A total of 105 patients (105 ankles), matched for age, gender, body mass index, and follow-up duration, were divided into three groups by pre-operative coronal plane tibiotalar angle; neutral (< 5°), moderate (5° to 15°) and severe (> 15°) varus deformity. American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, a visual analogue scale (VAS), and Short Form (SF)-36 score were used to compare the clinical outcomes after a mean follow-up period of 51 months (24 to 147).

RESULTS

The post-operative AOFAS, VAS scores, range of movement and complication rates did not significantly differ among three groups. However, there was less improvement in the SF-36 score of the severe varus group (p = 0.008). The mean post-operative tibiotalar alignment was 2.6° (0.1° to 8.9°), 3.1° (0.1° to 6.5°) and 4.6° (1.0° to 10.6°) in the neutral, moderate and severe groups respectively. Although the severe varus group showed less corrected alignment than the neutral group, the mean tibiotalar angles of the three groups were within neutral alignment.

CONCLUSION

TAA for moderate and severe varus arthritic deformity showed similar satisfactory clinical and radiographic outcomes as those obtained by patients in the neutral group when post-operative neutral alignment was achieved. Cite this article: Bone Joint J 2017;99-B:1335-42.

Are There Differences in Gait Mechanics in Patients With A Fixed Versus Mobile Bearing Total Ankle Arthroplasty? A Randomized Trial

BACKGROUND

Total ankle arthroplasty (TAA) is an alternative to arthrodesis, but no randomized trial has examined whether a fixed bearing or mobile bearing implant provides improved gait mechanics.

QUESTIONS/PURPOSES

We wished to determine if fixed- or mobile-bearing TAA results in a larger improvement in pain scores and gait mechanics from before surgery to 1 year after surgery, and to quantify differences in outcomes using statistical analysis and report the standardized effect sizes for such comparisons.

METHODS

Patients with end-stage ankle arthritis who were scheduled for TAA between November 2011 and June 2013 (n = 40; 16 men, 24 women; average age, 63 years; age range, 35-81 years) were prospectively recruited for this study from a single foot and ankle orthopaedic clinic. During this period, 185 patients underwent TAA, with 144 being eligible to participate in this study. Patients were eligible to participate if they were able to meet all study inclusion criteria, which were: no previous diagnosis of rheumatoid arthritis, a contralateral TAA, bilateral ankle arthritis, previous revision TAA, an ankle fusion revision, or able to walk without the use of an assistive device, weight less than 250 pounds (114 kg), a sagittal or coronal plane deformity less than 15°, no presence of avascular necrosis of the distal tibia, no current neuropathy, age older than 35 years, no history of a talar neck fracture, or an avascular talus. Of the 144 eligible patients, 40 consented to participate in our randomized trial. These 40 patients were randomly assigned to either the fixed (n = 20) or mobile bearing implant group (n = 20). Walking speed, bilateral peak dorsiflexion angle, peak plantar flexion angle, sagittal plane ankle ROM, peak ankle inversion angle, peak plantar flexion moment, peak plantar flexion power during stance, peak weight acceptance, and propulsive vertical ground reaction force were analyzed during seven self-selected speed level walking trials for 33 participants using an eight-camera motion analysis system and four force plates. Seven patients were not included in the analysis owing to cancelled surgery (one from each group) and five were lost to followup (four with fixed bearing and one with mobile bearing implants). A series of effect-size calculations and two-sample t-tests comparing postoperative and preoperative increases in outcome variables between implant types were used to determine the differences in the magnitude of improvement between the two patient cohorts from before surgery to 1 year after surgery. The sample size in this study enabled us to detect a standardized shift of 1.01 SDs between group means with 80% power and a type I error rate of 5% for all outcome variables in the study.

RESULTS

This randomized trial did not reveal any differences in outcomes between the two implant types under study at the sample size collected. In addition to these results, effect size analysis suggests that changes in outcome differ between implant types by less than 1 SD. Detection of the largest change score or observed effect (propulsive vertical ground reaction force [Fixed: 0.1 ± 0.1; 0.0-1.0; Mobile: 0.0 ± 0.1; 0.0-0.0; p = 0.0.051]) in this study would require a future trial to enroll 66 patients. However, the smallest change score or observed effect (walking speed [Fixed: 0.2 ± 0.3; 0.1-0.4; Mobile: 0.2 ± 0.3; 0.0-0.3; p = 0.742]) requires a sample size of 2336 to detect a significant difference with 80% power at the observed effect sizes.

CONCLUSIONS

To our knowledge, this is the first randomized study to report the observed effect size comparing improvements in outcome measures between fixed and mobile bearing implant types. This study was statistically powered to detect large effects and descriptively analyze observed effect sizes. Based on our results there were no statistically or clinically meaningful differences between the fixed and mobile bearing implants when examining gait mechanics and pain 1 year after TAA.

LEVEL OF EVIDENCE

Level II, therapeutic study.

The AES total ankle arthroplasty analysis of failures and survivorship at ten years

BACKGROUND

AES mobile-bearing total ankle replacement was developed from the Buechel Pappas model. It was withdrawn in 2009, after identification of a higher than expected complication rate. The purpose of the current study was to analyse clinical outcomes, failures and survival of the initial series of 50 AES published in 2009.

METHODS

In this single-centre continuous prospective study (2003-2006), 50 AES prostheses were included. Pre-operative osteoarthritis was mainly post-traumatic (50%) and secondary to instability (36%). All patients were assessed with clinical and radiographic follow-up at six months, one year, two years and every two to three years thereafter. A CT-scan was systematically performed before procedure, and at two years, five years and ten years. At last follow-up, all patients with TAR had a functional (SF 36, AOFAS) and clinical assessment. All complications or surgical events were analysed.

RESULTS

The mean follow-up was ten ± two years (range, 9-13). The mean AOFAS score was 75 points (range, 26-100). The mean SF 36 score was 69 points (range, 35-97). There was a significant deterioration in AOFAS score at five years and at last follow-up (p < 0.05). Fifteen TARs underwent reoperation for cyst curettage-graft because of development of periprosthetic lesions. Six of them ended up with prosthesis removal-arthrodesis. At the last follow-up, 14 TARs were removed for arthrodesis. Of the 30 prostheses seen at last follow-up, four are awaiting prosthesis removal-arthrodesis and one for cyst curettage-graft. The ten year survivorships free of any prosthesis removal or arthrodesis and free of any reoperation were 68% (95% CI, 55-85) and 57% (95% CI, 44-74), respectively.

CONCLUSION

Our data suggested a high rate of reoperation. Overall ten year survival was lower than with other designs, particularly due to cyst lesions.

LEVEL OF EVIDENCE

Level IV, prospective case series.

The effects of total ankle replacement on ankle joint mechanics during walking

BACKGROUND

End-stage ankle arthritis impairs joint function and patients' mobility. Total ankle replacement is a surgical procedure to treat severe ankle arthritis. Salto Talaris Anatomic Ankle^TM (STAA) was designed to mimic the normal ankle anatomy and flexion/extension of the ankle movement. The purpose of this study was to examine the effect of an STAA ankle replacement on ankle joint function and mechanics during gait.

METHODS

Five patients with end-stage unilateral ankle arthritis were recruited. Patients performed level walking in a laboratory setting on 2 occasions, prior to and 3 months after the STAA ankle surgeries. American Orthopedic Foot and Ankle Society (AOFAS) hindfoot score was obtained. A 12-camera motion capture system was used to perform walking analysis. Gait temporo-spatial parameters and ankle joint mechanics were evaluated. Paired Student's t tests and non-parametric Wilcoxon matched tests were performed to examine the differences in biomechanical variables between the pre- and post-surgery walking conditions.

RESULTS

Compared to the pre-surgical condition, at 3 months of post-STAA surgery, patients experienced greater improvement in AOFAS hindfoot score (p = 0.0001); the STAA ankle demonstrated a 31% increase in ankle joint excursion (p = 0.045), a 22% increase in ankle plantarflexor moment (p = 0.075), a 60% increase in ankle power absorption (p = 0.023), and a 68% increase in ankle power production (p = 0.039). Patients also demonstrated a 26% increase in walking speed (p = 0.005), a 20% increase in stride length (p = 0.013), a 15% decrease in double support time (p = 0.043), and a 5% decrease in total stance time (p = 0.055).

CONCLUSION

Three months after surgeries, the STAA patients experienced improvements in ankle function and gait parameters. The STAA ankle demonstrated improved ankle mechanics during daily activities such as walking.

Patient selection for total ankle arthroplasty

Total ankle arthroplasty is a treatment option for end-stage osteoarthritis of the ankle, as is ankle arthrodesis. Many variables, including patient characteristics, are thought to influence clinical outcome and survival. As with any surgery, but especially with total ankle replacement (TAR), patient selection is considered critical for good (long-term) outcome. In this review, we summarize the available scientific evidence regarding patient characteristics and its influence on the results of TAR.