Total ankle arthroplasty: a historical perspective

Design Rational for Total Ankle Arthroplasty: An Update

The design of total ankle arthroplasty (TAA) systems is rapidly evolving as device companies try to keep pace with the expansion of surgical indications and a refinement of techniques for TAA. Even since the publication of the latest "update," published in 2018, three new designs and three updates on preexisting third-generation implants came onto the market. Improvements in third-generation TAA systems include minimal bone resection, retaining ligamentous support, and anatomic balancing. Fourth-generation systems use 3D printing technology, improved talus and tibia designs based on CT scans of arthritic and normal ankles, and include patient-specific instrumentation. We will then explore the short-term and mid-term outcomes of the previously discussed six TAA systems-INBONE, INFINITY, INVISION (Stryker), Salto-Talaris (Smith and Nephew), Scandinavian Total Ankle Arthroplasty (Enovis), Trabecular Metal Total Ankle (Zimmer Biomet), and VANTAGE (Exactech). As more research pours in regarding mid- to long-term outcomes of these implants, it is important to assess the design rationale and summarize current outcome data for these implants.

Midterm Clinical Outcomes, Radiographic Outcomes, and Survivorship of the Infinity Total Ankle Arthroplasty

BACKGROUND

The Infinity Total Ankle Arthroplasty (Stryker, Mahwah, NJ) is a low-profile fixed-bearing implant first introduced in 2014. Although the short-term survivorship (2-4 years follow-up) and complication rates of the Infinity TAA have been reported, there are limited midterm outcome reports. The aim of this study was to describe the survivorship and clinical outcomes of a single-center experience with the Infinity implant at minimum 5-year follow-up.

METHODS

Retrospective review of 65 ankles that underwent primary total ankle arthroplasty (TAA) with the Infinity implant was conducted. Mean clinical follow-up was 6.5 years (range, 5.0-8.0). Preoperative and postoperative radiographs were measured to assess tibiotalar alignment, periprosthetic lucencies, and cysts. Preoperative, 2-year, and 5-year postoperative Foot and Ankle Outcome Score (FAOS) subscores were compared to assess midterm clinical outcomes. Survivorship assessment was determined by removal of 1 or both metallic implant components.

RESULTS

Survivorship of the implant was 93.8% at final follow-up. There were 4 revisions: 2 for tibial implant loosening, 1 for talar loosening, and 1 for loosening of both components. Three of the 4 revisions occurred within the first 2 years following implantation, and the last failure occurred at 7 years postoperatively. There were 11 reoperations in 10 (15%) ankles and 3 wound complications. There were 17 ankles (26.2%) with radiographic abnormalities around the implants, including 14 cases with tibial component lucencies and 4 cases of periimplant cysts. FAOS outcome measurement showed general stability between 2 and 5 years and substantial improvement from preoperative status.

CONCLUSION

To date this study is the largest midterm report on the Infinity total ankle prosthesis, with 65 implants at a mean follow-up of 6.5 years. We found good midterm implant survivorship, and patients experienced significant improvements in FAOS outcome scores and radiographic alignment at final follow-up.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

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.

Management of Periprosthetic Bone Cysts After Total Ankle Arthroplasty

Modern improvements in total ankle arthroplasty (TAA) have increased the performance of this procedure for treatment of end-stage ankle arthritis. A common finding after TAA is the formation of periprosthetic bone cysts, which can be clinically silent or result in TAA failure. The exact cause of periprosthetic bones cysts has not been established, but major theories are related to osteolysis secondary to implant wear, micromotion, and stress shielding. Treatment can be nonoperative with clinical observation for small, asymptomatic cysts. Large, progressive, and symptomatic cysts often merit surgical treatment with debridement and grafting, revision TAA, or salvage arthrodesis.

Early Radiographic and Clinical Outcomes of a Novel, Fixed-Bearing Fourth-Generation Total Ankle Replacement System

BACKGROUND

The Cadence Total Ankle System is a 2-component, fixed-bearing fourth-generation total ankle arthroplasty (TAA) system that was introduced for clinical use in 2016. The purpose of this study was to report non-inventor, non-industry funded survivorship, radiographic and clinical outcomes, and early complications following use of this implant at a minimum of 2 years.

METHODS

This single-center retrospective study included patients who underwent TAA by 2 surgeons with this novel fixed-bearing system between January 2017 and September 2018. Forty-eight patients were evaluated at an average of 33.6 months. Radiographic outcomes included preoperative and postoperative tibiotalar angle on anteroposterior radiographs of the ankle, sagittal tibial angle (STA) on lateral radiographs of the ankle, and periprosthetic lucency formation and location. Revision and reoperation data were collected, and patient-reported outcomes were assessed using Patient Reported Outcomes Measurement Information System (PROMIS). Subgroup analysis assessed associations between preoperative deformity, postoperative implant alignment, PROMIS scores, and periprosthetic lucency formation.

RESULTS

Survivorship of implant was 93.7%, with 3 revisions, 1 due to infection and 2 due to loosening of the implant (1 tibial and 1 talar component). Three patients had reoperations (6.3%): 2 for superficial infection and 1 for gutter debridement due to medial gutter impingement. Fifteen patients (35.8%) developed periprosthetic lucencies, all on the tibial side. PROMIS scores improved after surgery in all domains except Depression. Patients with significant postoperative periprosthetic lucency had worse postoperative PROMIS Physical function scores than patients without lucency (P < .05).

CONCLUSION

This study demonstrated excellent minimum 2-year clinical and radiographic outcomes and low revision and reoperation rates of this new fourth-generation TAA system. Future studies with longer follow-up, especially on patients with periprosthetic lucency, are necessary to investigate the long-term complications and understand the long-term functional and radiographic outcomes of this implant.

Infinity Ankle Arthroplasty Early Latin-America Experience and Patient Outcomes

INTRODUCTION

The promising data from Ankle Arthroplasty are consequence of the evolution of instruments and implants. Recent studies have shown good results in the short and intermediate follow-up, in addition to high patient satisfaction. The aim of this study is to present the results obtained with 49 cases treated with the Infinity total ankle prosthesis in 2 South America countries.

METHODS

This is a case series of 48 patients (27 women and 22 men), treated with 49 Infinity prostheses in Brazil and Colombia. They underwent surgical treatment between April 1, 2016, and January 18, 2020. We used the visual-analogue pain scale (VAS), the AOFAS score for ankle and hindfoot and the measurement of range of motion (ROM) in the pre- and post-surgical period. The radiological evaluation was performed on ankle radiographs in anteroposterior and lateral views, obtained in orthostasis, measuring the parameters suggested by Hintermann. Average follow-up was 4 years.

RESULTS

VAS reduced from an average of 7.94 to 1.98; AOFAS increased from 28.02 to 83.16 and ROM increased from 11.45 to 28.08. Distal Tibial Slope is higher for higher improvements in VAS and lower for higher improvements in AOFAS and ROM. We observed 4 wound infections, 1 intra-op medial malleolus fracture. No bone cysts, tibial or talar components subsidence, polyethylene component wear or failure were observed. No salvation procedures were required in this series.

DISCUSSION

This study results corroborates literature data showing great improvements in pain, functional pattern, and movement.

CONCLUSION

Infinity Ankle Arthroplasty is a safe and reproducible procedure with good outcomes at a short-term follow-up.

LEVEL OF EVIDENCES

4 - Case series.

Midterm Survivorship of the INBONE II Total Ankle Arthroplasty

BACKGROUND

The use of total ankle arthroplasty (TAA) in the treatment of ankle arthritis has grown substantially as advancements are made in design and surgical technique. Among the criteria guiding the choice between arthroplasty and arthrodesis, the long-term survival and postoperative outcomes are of crucial importance. Although outcomes of the INBONE I have been published, there is limited midterm survival data for the INBONE II. The purpose of this study was to determine the radiographic and patient-reported outcomes, and survivorship of this prosthesis in patients with a minimum 5-year follow-up.

METHODS

We retrospectively identified 51 ankles (46 patients) from 2010 to 2015 who underwent TAA with the INBONE II prosthesis at our institution. Of these, 44 cases had minimum clinical follow-up of 5 years (mean, 6.4; range 5-9). Median age was 66 years (range 42-81) and median BMI was 27.5 (range 20.1-33.0). A chart review was performed to record the incidence of revision and reoperation. Preoperative and postoperative radiographs were analyzed to assess the coronal tibiotalar alignment (TTA), the talar inclination angle, and the presence of periprosthetic lucencies and cyst formation. Preoperative and minimum 5-year postoperative Foot and Ankle Outcome Score (FAOS) subscales were compared. Survivorship was determined by incidence of revision, defined as removal of a metallic component.

RESULTS

The survivorship at 5 years was 98% and the rate of reoperation was 7.8% (n = 4); 2 patients underwent irrigation and debridement for infection, 1 patient underwent a medializing calcaneal osteotomy, and 1 patient underwent open gutter debridement, 1 patient underwent a revision of a subsided talar component at 3.2 years after index surgery. Average postoperative TTA was 88.6 degrees, with 42 rated as neutral (85-95 degrees), 2 varus (<85 degrees), and no valgus (>95 degrees) ankles. At final follow-up, asymptomatic periprosthetic cysts were observed in 8 patients. All FAOS domain scores improved between preoperative and final follow-up.

CONCLUSION

At midterm follow-up, we observed significant improvement in radiographic alignment and patient-reported outcome scores for the INBONE II total ankle prosthesis. In addition, this cohort has had a relatively low reoperation rate and high survivorship.

LEVEL OF EVIDENCE

Level IV, case series.

Intermediate-Term Outcomes of a Third-Generation, 2-Component Total Ankle Prosthesis

BACKGROUND

Short-term outcomes for the INBONE I and INBONE II tibial stems have been favorable. The INBONE-II talus has been shown to have lower reoperation and failure rates compared to its predecessor at short term follow-up. The purpose of the present study was to assess mid-term outcomes for the third generation, two component total ankle prosthesis at 5 to 9 years follow-up, evaluating both the tibial and talar components.

METHODS

All patients who underwent primary total ankle arthroplasty (TAA) with INBONE-II between July 2010 and July 2014 at a single institution and who were at least 5 years postoperative were included. A total of 15 ankles with a mean follow-up of 85 months (range, 61-113 months) met the criteria. Radiographs were assessed using coronal and sagittal alignment parameters preoperatively, at 6 weeks postoperatively, and at the most recent follow-up. Medical records were reviewed and revisions, reoperations, and complications were classified according to the criteria established by Vander Griend et al and Glazebrook et al, respectively.

RESULTS

The survivorship of the prosthesis at a mean of 85 months was 93.7%. The coronal and sagittal tibiotalar alignments 6 weeks after surgery were 2.1 degrees (P = .081) and 36% (P = .15), respectively. Maintenance of this alignment was observed during the latest follow-up (P = .684 and P = .837, respectively). One ankle (6.7%) required early component revision, while 4 (26.7%) required a non-implant-related revision. Six complications (2 high grade, 1 intermediate, and 3 low) in 5 ankles (33.3%) were recorded according to the Glazebrook classification system.

CONCLUSION

The present study is the first to report midterm follow-up after TAA with this third-generation, 2-component prothesis. High survivorship, maintenance of correction, and a low incidence of major complications were observed in this small case series. The most common complication overall was lateral gutter impingement, which accounted for the majority of the nonrevisional reoperations.

LEVEL OF EVIDENCE

Level IV, case series.

Comparison of the Efficiency and Safety of Total Ankle Replacement and Ankle Arthrodesis in the Treatment of Osteoarthritis: An Updated Systematic Review and Meta-analysis

While osteoarthritis is a common degenerative disease, ankle osteoarthritis is a subdivision that has received little attention. Two effective ways to treat osteoarthritis of the ankle are total ankle replacement (TAR) and ankle arthrodesis (AAD). Whether TAR or AAD is more beneficial for treatment is controversial. The purpose of this meta‐analysis was to compare the efficiency (clinical outcome and patient satisfaction) and safety (complications and survival) of these two procedures. The Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) statement was performed as a guideline for this study. Three electronic databases, PubMed, Web of Science, and Cochrane Library, were searched up to May 2019, with no language restrictions. Prospective or retrospective comparative studies were identified. The outcomes included clinical outcome, patient satisfaction, complications, and survival. Review Manager (Revman) 5.3 software was used to conduct the data analysis. We only selected literature from the past 5 years (no earlier than 2015). Seven comparative studies were included. There were six cohort studies and one cross‐sectional study. The Newcastle–Ottawa Scale (NOS) was used to assess the quality of cohort studies, and The Agency for Healthcare Research and Quality (AHRQ) checklist was chosen to assess the quality of cross‐sectional studies. No significant difference was observed for efficiency and safety. Clinical outcome was included in five studies with four different scoring systems. Two of them used the American Orthopaedic Foot & Ankle Society (AOFAS) questionnaire scores to assess the two procedures (mean difference, −4.26; 95% confidence interval [CI], −11.37–2.85; P = 0.24; I² = 1%). Patient satisfaction (risk ratio [RR], 0.96; 95% CI, 0.65–1.40; P = 0.82; I² = 54%), complications (RR, 1.15; 95% CI, 0.16–8.21; P = 0.89; I² = 84%), and survival (RR, 1.91; 95% CI, 0.33–11.08; P = 0.47; I² = 90%) showed no significant difference between the TAR group and the AAD group. This meta‐analysis showed no statistically significant difference between TAR and AAD in clinical outcome, patient satisfaction, complications, and survival. This revealed that TAR and AAD could appear to have similar results in these aspects. Therefore, the present results are not sufficient to conclude which of these two methods is better. Further studies are needed to obtain more clues.

Outcome of ankle arthrodesis and ankle prosthesis: a review of the current status

INTRODUCTION

In advanced stages of ankle osteoarthritis (OA), ankle arthrodesis (AA) or total ankle arthroplasty (TAR) may be necessary. Our purpose is to compare AA and total ankle replacement for the surgical management of end stage ankle OA.

SOURCES OF DATA

We conducted a literature search of PubMed, Medline, CINAHL, Cochrane, Embase and Google Scholar databases using the terms 'ankle' in combination with 'OA', 'arthrodesis', 'arthroplasty', 'joint fusion', 'joint replacement'. Studies where treatment was exclusively total ankle replacement or AA were excluded. Treatment characteristics and outcome parameters (overall postoperative outcome and complication rate) were reviewed.

AREAS OF AGREEMENT

When counseling patients who are considering their options with regard to ankle arthritis treatment, surgeons should determine on an individual basis which procedure is more suitable.

AREAS OF CONTROVERSY

TAR has become an accepted treatment for end-stage OA, but revision rates for TAR are significant higher than for AA (odds ratio 2.28 95% confidence interval [CI], 1.63-3.19; P < 0.0001).

GROWING POINTS

The results of TAA are gradually improving, but the procedure cannot yet be recommended for the routine management of ankle OA.

AREAS TIMELY FOR DEVELOPING RESEARCH

Although there is some evidence to support TAR to conserve ankle motion and offer improved function and decreased pain with high satisfaction rates, revision rates for TAR are significantly higher than revision rates for AA. Proper patient selection should be better addressed in future studies for successful treatment of end-stage ankle OA.

LEVEL OF EVIDENCE

Systematic review, level III.

Hallux valgus, ankle osteoarthrosis and adult acquired flatfoot deformity: a review of three common foot and ankle pathologies and their treatments

The pathogenesis of hallux valgus deformity is multifactorial. Conservative treatment can alleviate pain but is unable to correct the deformity. Surgical treatment must be adapted to the type and severity of the deformity. Success of surgical treatment ranges from 80% to 95%, and complication rates range from 10% to 30%.Ankle osteoarthrosis most commonly occurs as a consequence of trauma. Ankle arthrodesis and total ankle replacement are the most common surgical treatments of end stage ankle osteoarthrosis. Both types of surgery result in similar clinical improvement at midterm; however, gait analysis has demonstrated the superiority of total ankle replacement over arthrodesis. More recently, conservative surgery (extraarticular alignment osteotomies) around the ankle has gained popularity in treating early- to mid-stage ankle osteoarthrosis.Adult acquired flatfoot deformity is a consequence of posterior tibial tendon dysfunction in 80% of cases. Classification is based upon the function of the tibialis posterior tendon, the reducibility of the deformity, and the condition of the ankle joint. Conservative treatment includes orthotics and eccentric muscle training. Functional surgery is indicated for treatment in the early stages. In case of fixed deformity, corrective and stabilising surgery is performed. Cite this article: Crevoisier X, Assal M, Stanekova K. Hallux valgus, ankle osteoarthrosis and adult acquired flatfoot deformity: a review of three common foot and ankle pathologies and their treatments. EFORT Open Rev 2016;1:58-64. DOI: 10.1302/2058-5241.1.000015.

Failure modes for total ankle arthroplasty: a statistical analysis of the Norwegian Arthroplasty Register

BACKGROUND

It is imperative to understand the most common failure modes of total ankle arthroplasty (TAA) to appropriately allocate the resources, healthcare costs, enhancing surgical treatment methods, and improve design and longevity of the implant. The objective of this study was to investigate the primary mode or modes of failure (Loose talar component, loose tibial component, dislocation, instability, misalignment, deep infection, Fracture (near implant), Pain, defect polyethylene (PE), other, and missing information) of TAA implants, so these failure mode/modes can be targeted for future improvement.

METHODS

The Norwegian Total Hip Arthroplasty Register 2008 was chosen as the primary source of data since the register have been in existence for 20 years and also gives more specific failure modes than other registries. Tukey-Kramer method was applied to Norwegian Arthroplasty Register.

RESULTS

After the application of the Tukey-Kramer method, it is evident that there is no significant difference between any of the failure modes that are pertinent to the ankle. However, there is significant evidence that the number of ankle arthroplasties are increasing with time.

CONCLUSIONS

Since there is no statistical evidence showing which failure mode contributes most to revision surgeries, it is concluded that more information/data is needed to further investigate failure modes in ankle arthroplasties. Since the numbers of such surgeries are increasing, sufficient data should become available in time.

Mobile- and fixed-bearing total ankle prostheses: is there really a difference?

Approximately 1% of the world's adult population is affected by ankle osteoarthritis (OA). Therapeutic options include conservative and surgical measures. Because of substantial progress in total ankle replacement, ankle fusion is no longer the "gold standard" therapy for end-stage ankle OA. Various ankle prostheses have been designed and are currently available. This article reviews the in vitro studies addressing the biomechanics and kinematics of the replaced ankle. Furthermore, a systematic literature review was conducted to assess possible differences in clinical outcomes, including prosthesis survivorship and postoperative range of motion between mobile- and fixed-bearing total ankle prostheses.

Outcome evaluation of ankle osteoarthritis treatments: plantar pressure analysis during relatively long-distance walking

BACKGROUND

This study aimed to use plantar pressure analysis in relatively long-distance walking for objective outcome evaluation of ankle osteoarthritis treatments, i.e., ankle arthrodesis and total ankle replacement.

METHODS

Forty-seven subjects in four groups: three patient groups and controls, participated in the study. Each subject walked twice in 50-m trials. Plantar pressure under the pathological foot was measured using pressure insoles. Six parameters: initial contact time, terminal contact time, maximum force time, peak pressure time, maximum force and peak pressure were calculated and averaged over trials in ten regions of foot. The parameters in each region were compared between patient groups and controls and their effect size was estimated. Besides, the correlations between pressure parameters and clinical scales were calculated.

FINDINGS

We observed based on temporal parameters that patients postpone the heel-off event, when high force in forefoot and high ankle moment happens. Also based on maximum force and peak pressure, the patients apply smoothened maximum forces on the affected foot. In ten regions, some parameters showed improvements after total ankle replacement, some showed alteration of foot function after ankle arthrodesis and some others showed still abnormality after both surgical treatments. These parameters showed also significant correlation with clinical scales in at least two regions of foot.

INTERPRETATION

Plantar pressure parameters in relatively long-distance trials showed to be strong tools for outcome evaluation of ankle osteoarthritis treatments.

Total ankle arthroplasty in France

OBJECTIVES

After more than 10 years' experience in France, the French Foot Surgery Association (Association française de chirurgie du pied [AFCP]) presents an update on mobile-bearing ankle prostheses, based on a multicenter study. META-ANALYSIS - BIOMECHANICS - ASSESSMENT AND INDICATIONS: A preliminary comparative meta-analysis of the literature studies on ankle and prosthesis biomechanics, reviews validated indications and contra-indications, and details clinical and radiological outcomes assessment protocols.

PROFESSIONAL SURVEY

Sixty-three surgeons (95% AFCP members) answered a professional online survey, by email or regular post: 70% performed total ankle replacement (TAR), 39% of them at least two per year and 16% more than 10 per year, resulting in 317 TARs per year or 50% of the French activity and 312 arthrodeses per year or 17% of the French activity - which gave the survey considerable power. In 2004-2005, 46% of the TARs implanted were AES, 38% Salto and 9% Hintegra.

GAIT ANALYSIS FOLLOWING TAR

This study included two series of patients (15 in Brussels and six in Paris) with laboratory gait analysis preoperatively and at 6 months' and 1 year's FU. Following TAR, speed, cadence and strides increased and mean total work approximated normal values. These two independent studies quantified the advantages of TAR over arthrodesis.

MULTICENTER STUDY

This retrospective study had a minimum follow-up of 1 year. Results were not distinguished between the four types of prosthesis (approved by the French Healthcare Agency [HAS]) involved. Inclusion criteria for operators were: AFCP membership, and experience of more than 20 prostheses of a given type. Twelve out of 15 centers responded and undertook to include continuous series. Data were centralized on a dedicated anonymous online site. Five hundred and ninety-two TARs (388 Salto, 173 AES, 22 Hintegra, nine Star) in 555 patients (mean age, 56.4 years; range 17-84 yrs) were included. Indications were post-traumatic arthritis (48%), arthritis associated with laxity (15%), inflammatory arthropathy (20%), primitive arthritis (9%), prosthetic revision (2%), and miscellaneous (5%). Sixty-one percent of operations included associated procedures: 208 Achilles lengthenings, 45 subtalar arthrodeses, nine calcaneal osteotomies and 45 lateral ligament reconstructions. Complications comprised 53 malleolar fractures, and 39 cutaneous and seven infections (9%). At a mean 37 months' FU, 87.5% of patients were satisfied or very satisfied; mean functional score was 82.1/100; radiographic mobility, 23.2 degrees ; and total SF 36 score (on the Short Form Health Survey), 66. X-ray found stable anchorage in 98% of cases, cysts in 15%, and calcification in 4%.

REVISION FOR FAILURE

Overall cumulated survivorship was 88% at 71 months: 22 patients underwent arthrodesis (61% satisfied), and 10 implant replacement (50% satisfied).

CONCLUSION

This multioperator, multi-implant series of 592 patients confirmed literature data. Prospective follow-up of the cohorts managed in these expert centers is essential, in order to make available long-term data.

Total ankle arthroplasty in the rheumatoid patient

Total ankle replacement in the rheumatoid patient is a feasible and effective treatment for ankle arthritis. The benefits of ankle prosthesis are good pain relief, acceptable function, and patient satisfaction. It is a joint-sparing procedure for restoring functionality. All investigators of total ankle replacement feel that, as clinicians gain experience with the procedure and related products, difficulties and risks associated with the procedure will decline. Following an early history of failure and poor patient satisfaction, more recent results have shown promise.

Analysis of ankle range of motion and functional outcome following total ankle arthoplasty

The success of ankle joint replacement has primarily been reviewed with respect to patient morbidity and survivorship rather than patient satisfaction. A retrospective review was performed of 95 patients who had undergone a total ankle replacement and who had completed both postoperative range of motion fluoroscopy and a subjective patient score sheet. Collected data included age, body mass index, length of follow-up, presence of complications, performance of adjunctive procedures, range of motion, and the etiology of the end-stage arthritis. These variables were then compared with patient satisfaction to see if there were any predictive conditions of successful outcomes. Patients older than 60 years and those with a body mass index (BMI) less than 30 demonstrated a significant positive association with subjective satisfaction scores (P = .0023 and .0008, respectively). The amount of postoperative range of motion did not appear to correlate with patient satisfaction. Furthermore, there were no significant associations of patient satisfaction with a patient age younger than 60 years, a BMI greater than 30, additional procedures, perioperative complications, the length of time after surgery, and the presenting etiology.

Posttraumatic ankle arthritis: an update on conservative and surgical management

This manuscript offers current information regarding the examination, conservative treatment, and surgical treatment for individuals with posttraumatic arthritis. Although inflammatory and osteoarthritis can occur, posttraumatic arthritis is the most common form of arthritis to affect the ankle. Posttraumatic ankle arthritis occurs in a generally younger, active population. It is radiographically characterized by an asymmetrical degenerative process and may be associated with a history of trauma, instability, and/or lower extremity malalignment. When choosing between conservative/nonoperative versus surgical intervention, the extent of subchondral bone exposed and the time over which the arthritis has developed are factors that should be considered. The role and effectiveness for conservative treatment, such as medication, patient education, shoe modification, bracing, stretching, mobilization, strengthening, and symptom management, needs to be further determined. Surgical procedures for posttraumatic ankle arthritis can include distraction arthroplasty, arthrodesis, or total ankle arthroplasty. Unlike the relatively new procedure of distraction arthroplasty, the outcomes for arthrodesis have been well defined. Arthrodesis generally has a good outcome, but its limitations have been recognized. These limitations include the extended time required to achieve fusion, potential for nonunion, arthritis developing in adjacent joints, leg length discrepancy, malalignment, chronic edema, symptoms due to the hardware, stress fractures, and continued pain. While first generation total ankle arthroplasty led to poor results, advancements in prosthetic design and surgical technique have revived optimism regarding total ankle arthroplasty as an alternative to arthrodesis. The key for the future of total ankle arthroplasty may not be related to the development of newer ankle components but rather in refining the criteria to determine who would best benefit from joint replacement versus fusion.

The use of autologous concentrated growth factors to promote syndesmosis fusion in the Agility total ankle replacement. A preliminary study

BACKGROUND

The Agility (DePuy, Warsaw, Indiana) total ankle replacement has been in use since 1984. One of the most common complications continues to be delayed union or nonunions of the distal tibiofibular syndesmosis. In the reported studies on the Agility ankle the delayed union and nonunion rate can be as high as 38%.

METHODS

Since 1999, 114 Agility total ankle replacements were done at two centers in the United States without the use of autologous concentrated growth factors. Since July of 2001, 66 Agility ankles were implanted with Symphony (DePuy, Warsaw, Indiana) augmented bone grafting. The standard operative technique was followed in all the patients. Prospective data was collected on all patients. The standard ankle radiographs were taken preoperatively and postoperative at 8 weeks, 12 weeks, 16 weeks, 6 months, and yearly. CT scans were obtained at 6 months if fusion at the syndesmosis was questionable. The Graphpad Instat software (Graphpad Software Inc., San Diego, CA) was used for statistical analysis. The two-tailed unpaired t-test was used, and the value <0.05 was considered significant.

RESULTS

There was no statistical difference in the demographic data for the two groups. In 114 ankle replacements without autologous concentrated growth factors 70 fused at 8 weeks (61%), 14 fused at 12 weeks (12%), 13 fused at 6 months (12%). There were 17 nonunions (15%); delayed unions (3 to 6 months) and nonunions, therefore, equaled 27%. The syndesmosis fused in 50 of the 66 ankle replacements (76%) that had autologous concentrated growth fractures at 8 weeks (76%); 12 fused at 3 months (18%), 2 fused at 6 months (3%), 2 had nonunions (3%). Delayed unions (3 to 6 months) and nonunions equaled 6%. There was a statistically significant improvement in the 8- and 12-week fusion rates, and a statistically significant reduction in delayed unions and nonunions.

CONCLUSION

Autologous concentrated growth factors appear to make a significant positive difference in the syndesmosis union rate in total ankle replacements.

Enhancement of syndesmotic fusion rates in total ankle arthroplasty with the use of autologous platelet concentrate

BACKGROUND

One of the challenges of total ankle arthroplasty continues to be achieving a solid distal fusion of the tibiofibular joint. Delayed union rates of 29% to 38% and the nonunion rates of 9% to 18% for syndesmotic fusion have been documented. The risk of tibial component migration has been reported to increase 8.5 times if a solid syndesmotic fusion is absent. Growth factors have been shown to accelerate bone healing and may enhance the fusion of the syndesmosis and, thereby, decrease the frequency of nonunion and subsequent tibial component migration.

METHODS

An autologous platelet concentrate was used to increase the amount of growth factors at the site of the distal tibiofibular joint fusion in 20 total ankle arthroplasties.

RESULTS

Our 6-month fusion rate was 100%. When compared to historical controls (6-month fusion rate of 62%) the difference was statistically significant (p < 0.0001).

CONCLUSION

The improved rate of distal tibiofibular fusion may be attributable to the increased presence of growth factors provided by an autologous platelet concentrate.