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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Outcomes after total ankle arthroplasty with an average follow-up of 10 years: A systematic review and meta-analysis

BACKGROUND

The literature demonstrating positive outcomes after total ankle arthroplasty (TAA) is mounting. However, the long-term outcomes of TAA (≥ 10 years) remain minimally reported. The purpose of this systematic review and meta-analysis was to evaluate outcome metrics over multiple TAA studies with greater than 10 years of average follow-up.

METHODS

TAA studies were searched in Medline, Embase, and Scopus from the date of inception to September 12, 2022. Inclusion criteria included 1) studies of patients that underwent uncemented TAA, and 2) studies with an average follow-up time of at least ten years. Manuscripts in non-English languages and isolated abstracts were excluded. We collected American Orthopaedic Foot and Ankle Score (AOFAS) and Visual Analog Scale (VAS) scores from the included studies for pooled meta-analysis. Due to the varying definition of survivability between studies, this metric was not assessed in our final evaluation.

RESULTS

Our data included approximately 3651 patients (3782 ankles). Of the 25 studies with an average follow-up of 10 years included in the systematic review, 5 provided pre- and post-operative AOFAS means and 5 provided pre- and post-operative VAS means with associated measures of variability and were included in our meta-analysis. The weighted mean difference between pre-and post-operative AOFAS and VAS scores was -40.36 (95% CI -47.24 to -33.47) and 4.52 (95% CI: 2.26-6.43), respectively. The risk of bias was low to moderate for the included studies.

CONCLUSION

Outcomes following TAA are favorable and indicate patient-reported outcome improvement over long-term follow-up. However, a significant amount of heterogeneity exists between studies. Future, prospective, randomized research should focus on standardizing outcome measures, survivorship, and complication reporting methodologies to allow for pooled meta-analyses of these important outcome metrics.

A single-centre experience of 29 total ankle replacement in haemophiliac patients: Therapeutic management, factor consumption and cost

INTRODUCTION

In patients with haemophilia, repeated bleeding in large joints leads to chronic haemophilic arthropathy, a rare disease that can be managed surgically with ankle arthrodesis or with total ankle replacement (TAR). TAR has been reported to provide good surgical results in the medium/long-term and allow preservation of joint mobility but the medical therapeutic management of the patients has not been described.

AIM

To describe the medical therapeutic management of TAR.

METHODS

All patients with haemophilia A/B, with haemophilic ankle arthropathy, and who underwent TAR between April 2006 and October 2019 were retrospectively included. Factor consumption, perioperative and early complications, volume of blood lost, and orthopaedic data were collected.

RESULTS

A total of 25 patients underwent 29 TAR (mean age was 44.7 years [range: 26-65]). In the 17 patients with HA without history of anti-FVIII inhibitor, the mean ± SD consumption the day of surgery was 116 ± 16 UI/kg when clotting factors were administered by continuous infusion, 106 ± 13 UI/kg when SHL factors were administered by bolus infusion, and 75 ± 22 UI/kg when EHL factors were administered by bolus infusion. During hospitalisation, the mean factor cost was €38,073 (83.7% of the total cost of surgery). Mean blood loss was significantly lower in patients treated with tranexamic acid (164 mL, range: 40-300) than in those not (300 mL, range: 70-800; p = .01). Six patients had haematoma. The 10-year survival free of any prosthesis removal/arthrodesis was estimated to be 92.2% (95% CI [83; 100]).

CONCLUSION

The medical therapeutic management of TAR is complex, carried out by a multidisciplinary team but effective in avoiding the occurrence of complications.

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.

The ceramic coated implant (CCI). Evolution total ankle replacements: a retrospective analysis of 40 ankles with 8 years follow-up

Diminutive data is available on the outcome of several previously used total ankle replacement implants. The purpose of this study was to investigate the medium-term functional and radiological outcome and implant survival of the CCI Evolution implant. Consecutive series of 40 ankles operated in our hospital with primary TAR using the CCI Evolution implant in 2010-2013 were available for follow-up. The prospective clinical and radiographic data including the Kofoed score, subjective satisfaction and standard radiographs were collected preoperatively and at fixed time-points postoperatively. A CT was obtained in cases where osteolysis or loosening were suspected. The improvement of the Kofoed score and subjective satisfaction were statistically significant (p<0.0001). The implant survival was 97% (95% confidence interval (CI) 81%-100 %) at 5 years, and 81 % (95% confidence interval (CI) 60 %-92%) at 8 years. There were altogether 25 (64%) complications. Overall revision rate was 28% and failure rate 13%. The CCI implant outcome was not acceptable. The malposition of prosthetic components, subsidence, and peri-implant osteolysis were recorded often. Although the patient reported outcome measures improved, mostly due to positive changes in pain severity, overall revision and failure rates were high and comparable with previous findings of the CCI implant.

Metal debris release is commonly seen from explanted total ankle replacements

This study aimed to characterise the damage mechanisms present on the metal components used in various contemporary total ankle replacements. Twenty-seven explanted total ankle replacements comprising 8 different designs (3 fixed bearing and 5 mobile bearing) were analysed using various explant analysis techniques. Pitting and scratching were the most commonly observed wear features. Microscopic analysis revealed metallic pitting on 52% of tibial components and 95% of talar components. Pitting was identified on more cobalt-chromium than titanium alloy tibial components (63% versus 0%). Non-contact profilometry confirmed the presence of pitting, with significant (p < 0.05) differences in the measured average surface roughness values of pitted and unpitted areas for tibial and talar components. There was macroscopically visible sliding plane scratching, indicating the presence of hard third body particles, on 78% of talar components. Changes to the non-articulating surfaces coatings in terms of coating loss and/or changes in reflectivity was identified visually on 80% of metal components. Scanning electron microscopy with energy dispersive X-ray spectroscopy identified metallic embedded debris in 19% of polyethylene inserts. This explant study demonstrates the release of metal debris from both the metallic tibial and talar component articulating surfaces and non-articulating surface coatings of various contemporary total ankle replacements. Metal particulate debris release from total ankle replacements may be more common than previously recognised. Metal debris should be considered in further study into the aetiology of failed total ankle arthroplasty.

Complications after total ankle arthroplasty- A systematic review

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

IV.

Long-term Follow-up of 254 Ceramic Coated Implant (CCI) Evolution Total Ankle Replacements

BACKGROUND

The ceramic coated implant (CCI) Evolution was a third-generation implant design used in approximately 2000 total ankle replacements (TARs) between 2003 and 2016. Because this implant was abandoned, long-term follow-up studies are lacking.

METHODS

All patients undergoing TAR using a CCI prosthesis between 2004 and 2012 were included for analysis. Preoperatively the tibiotalar alignment was measured, and postoperatively the patients were followed up clinically, with radiographs and by questionnaire. The primary outcome was implant survival at 10 years of follow-up. Implant survival was also compared for (1) inflammatory joint disease vs noninflammatory joint disease and (2) preoperative tibiotalar neutral vs varus or valgus alignment. The secondary outcomes were complications, reoperations, and function (assessed by patient-reported outcome measures).

RESULTS

Two hundred fifty-four TARs were performed in 237 patients. Two hundred twelve additional procedures were performed to achieve stable ankles. At 10-year follow-up, the survival was 67.5%, with an average time to revision of 4.5 years. The 10-year survival of the inflammatory joint disease group was 76.8% and of the noninflammatory joint group 63.1% (P = .44). In 248 TARs, the preoperative tibiotalar alignment was measured; (62% neutral, 25% varus, and 13% valgus), these showed 10-year survival rates of 74.7%, 48.2%, and 68.9% respectively (P = .07). The complication rate was 54%; 37% of patients underwent reoperation. At a mean of 8.5 years, postoperative satisfaction scored an average of 7.0 (SD 2.26) on a 0- to 10-point numeric rating scale. The mean Foot and Ankle Ability Measure sports subscore was 24.7, the mean Foot and Ankle Outcome Score (FAOS) sports subscore was 42.8, and the mean 36-Item Short Form Health Survey score was 40.0. Regarding daily activities, the mean FAOS was 81.0.

CONCLUSION

This is currently the sole study reporting the long-term results of the CCI prosthesis. The survival and functional outcomes were inferior to other third-generation mobile-bearing ankle implants.

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.

Post-operative management after total ankle arthroplasty: A systematic review of the literature

BACKGROUND

Currently, there is no consensus on the most appropriate post-operative management for patients undergoing total ankle arthroplasty. The aim of this study is therefore to offer a systematic review of the pertaining literature to identify current post-operative protocols and describe possible differences.

METHODS

A systematic review to identify recent studies concerning the post-operative management after total ankle arthroplasty was conducted. Five topics were analyzed: length of hospital stay, type and duration of immobilization, weight-bearing management, post-operative pharmacological therapies, adopted rehabilitation scheme.

RESULTS

Eighty-four studies met the inclusion criteria and were included in the review process. Most of the papers appear to have conflicting opinions with no consensus and homogeneous protocols.

CONCLUSION

Due to various methodological limitations, it is not possible to provide sufficiently supported evidence-based recommendations, and it is therefore difficult to determine the superiority of one post-operative protocol over the others after total ankle arthroplasty.

Patient reported outcome measures in ankle replacement versus ankle arthrodesis - A systematic review

OBJECTIVES

Compare the functional outcomes of comparative studies of ankle arthrodesis (AA) and total ankle replacements (TAR).

DESIGN

Systematic review using PRISMA guidelines.

DATA SOURCES

Medline, Cochrane and EMBASE databases in July 2020.

ELIGIBILITY CRITERIA

Studies that directly compared TAR and AA which reported patient reported outcomes measures (PROMs) of pain, function and quality of life.

DATA EXTRACTION AND SYNTHESIS

Two authors independently reviewed all papers. PROMs were allocated into pain, function or quality of life domains. Two summary statistics were created to allow for analysis of the PROMs. These statistics were the mean difference in post-operative score and the mean difference in the change of score.

RESULTS

1323 papers were assessed of which 20 papers were included. 898 ankle arthrodesis and 1638 ankle replacements were evaluated. The mean follow up was 3.3 years (range 0.5-13.0 years). AA patients had a mean age of 55.7 (range 20-82) and TAR 62.5 (range 21-89). There was major heterogeneity in outcomes used. We were unable to find a significant difference between the reported change in PROMs following TAR and AA. 29.3% of PROMs and their subscores showed TAR had better outcomes, 68.7% showed no significant difference and only 2.0% showed AA to have better outcomes.

CONCLUSIONS

The majority of published studies found equality in patient reported outcomes following TAR and AA although the quality of the studies was of low-level evidence. There is an urgent need for randomised controlled studies to definitively answer this important clinical question.

Short-Term Complications and Outcomes of the Cadence Total Ankle Arthroplasty

BACKGROUND

Total ankle arthroplasty (TAA) is an increasingly popular option for the operative treatment of ankle arthritis. The Cadence TAA entered clinical use in 2016 and was designed to address common failure modes of prior systems. We report early complications and radiographic and clinical outcomes of this total ankle system at a minimum of 2 years of follow-up.

METHODS

We performed a retrospective review of a consecutive cohort of patients undergoing primary Cadence TAA by a single surgeon from 2016 to 2017. Complications and reoperations were documented using the American Orthopaedic Foot & Ankle Society (AOFAS) TAA reoperation coding system. Patients completed the Foot and Ankle Ability Measure (FAAM) Activities of Daily Living (ADL) and Sport subscales, SF-12 Mental (MCS) and Physical (PCS) Component Summaries, and visual analog scale (VAS) pain rating (0-100). Radiographic evaluation was performed to assess postoperative range of motion (ROM) of the sole of the foot relative to the long axis of the tibia, alignment, and implant complications.

RESULTS

Fifty-eight patients with a mean age of 63.3 years and mean body mass index of 31.9 kg/m² were included. Twelve of 58 patients (20.7%) underwent an additional procedure(s) within 2 years, including 3 (5.2%) who required removal of one or both components, 2 for infection and 1 for osteolysis. Forty-three patients were followed for a minimum of 2 years with radiographic imaging; 1 patient's (2.3%) radiographs had signs of peri-implant osteolysis, with no cases demonstrating loosening or subsidence. FAAM-ADL, FAAM-Sport, SF-12 PCS, and VAS pain scores all improved at a mean of 27.4 months postoperatively, with mean score changes (± SD) of 16.3 (± 22.0), 25.3 (± 24.5), 6.0 (± 11.1), and -32.3 (± 39.8), respectively. Radiographic analysis revealed that average coronal alignment improved from 6.9 degrees from neutral preoperatively to 2.3 degrees postoperatively. The average ROM of the foot relative to the tibia was 36.5 degrees total arc of motion based on lateral radiographs.

CONCLUSION

Early experience with this 2-component total ankle replacement was associated with a high component retention rate, improved coronal plane alignment, good postoperative ROM, radiographically stable implants, and improved patient function.

LEVEL OF EVIDENCE

Level IV, case series.

Comparison of Preoperative Bone Density in Patients With and Without Periprosthetic Osteolysis Following Total Ankle Arthroplasty

BACKGROUND

Modern total ankle arthroplasty (TAA) prostheses are uncemented press-fit designs whose stability is dependent on bone ingrowth. Preoperative insufficient bone density reduces initial local stability at the bone-implant interface, and we hypothesized that this may play a role in periprosthetic osteolysis. We aimed to investigate the preoperative bone density of the distal tibia and talus and compare these in patients with and without osteolysis.

METHODS

We enrolled 209 patients (218 ankles) who underwent primary TAA using the HINTEGRA prosthesis. The overall mean follow-up duration was 66 (range, 24-161) months. The patients were allocated into 2 groups according to the presence of periprosthetic osteolysis: the osteolysis group (64 patients, 65 ankles) and nonosteolysis group (145 patients, 153 ankles). Between the 2 groups, we investigated and compared the radiographic outcomes, including the Hounsfield unit (HU) value around the ankle joint and the coronal plane alignment.

RESULTS

HU values of the tibia and talus measured at 5 mm from the reference points were higher than those at 10 mm in each group. However, comparing the osteolysis and nonosteolysis groups, we found no significant intergroup difference in HU value at every measured level in the tibia and talus (P > .05). Concerning the coronal plane alignment, there were no significant between-group differences in the tibiotalar and talar tilt angles (P > .05).

CONCLUSION

Patients with osteolysis showed similar preoperative bone density of the distal tibia and talus compared with patients without osteolysis. Our results suggest that low bone density around the ankle joint may not be associated with increased development of osteolysis.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

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.

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

BACKGROUND

Total ankle arthroplasty (TAA) is increasingly gaining recognition as an alternative to ankle arthrodesis in the treatment of end-stage ankle arthritis. Despite high rates of adverse events during early inception, newer generations of uncemented prosthesis and design modifications have improved outcomes. Questions remain regarding the long-term outcomes and implant survivorship of TAA.

AIM

This analysis aims to establish an updated review of intermediate and long-term clinical outcome and complication profile of TAA.

PATIENTS AND METHODS

A multi database search was performed on 14th October 2018 according to PRISMA guidelines. All articles that involved patients undergoing uncemented TAA with 5 years minimum follow-up, reported clinical outcome or complication profile of TAA were included. Seventeen observational studies were included in the review, with 1127 and 262 ankles in the 5 and 10 years minimum follow-up groups respectively.

RESULTS

Mean difference between pre- and post-operative AOFAS score was 43.60 (95%CI: 37.51-49.69, p<0.001) at 5 years minimum follow-up. At 5 years minimum follow-up, pooled proportion (PP) of prostheses revision for any reason other than polyethylene exchange was 0.122 (95%CI: 0.084-0.173), all cause revision was 0.185 (95%CI: 0.131-0.256), unplanned reoperation was 0.288 (95%CI: 0.204-0.390) and all infection was 0.033 (95%CI: 0.021-0.051). At 10 years minimum follow-up, PP of prostheses revision for any reason other than polyethylene exchange was 0.202 (95%CI: 0.118-0.325), all cause revision was 0.305 (95%CI: 0.191-0.448), unplanned reoperation was 0.422 (95%CI: 0.260-0.603) and all infection was 0.029 (95%CI: 0.013-0.066).

CONCLUSION

Despite good intermediate and long-term functional outcome measures, TAA has relatively higher revision surgery prevalence with longer follow-up periods. Further research should be directed towards identifying patient populations that would best benefit from TAA and those at greatest risk of requiring revision surgery.

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

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

Positive and negative factors for the treatment outcomes following total ankle arthroplasty? A systematic review

BACKGROUND

Patient selection, surgeon's experience and implant design play an integral role and affect the treatment outcomes of total ankle arthroplasty (TAA). The aims of this study were to investigate the positive and negative attributes that correlate with different clinical and radiographic outcomes.

METHODS

Eight-nine studies matched the inclusion criteria: (1) studies of primary TAA with uncemented prosthesis; (2) mean follow-up of no less than 2-year; (3) reports of clinical and radiographic outcomes, and exclusion criteria: (1) non-English study; (2) more than one type of prosthesis without separated data; (3) kin studies with shorter follow-up or smaller cohort. Age, etiology, preoperative deformity, surgeon's experience, follow-up duration and prosthetic type were studied with respect to different outcomes by mixed-effects logistic regression analysis.

RESULTS

Patients factor: older patients reported less pain or stiffness and demonstrated less radiographic loosening which did not require additional surgical intervention. More traumatic arthritis experienced adjacent joints degeneration after TAA. Surgeon factor: less experienced surgeons had more intraoperative complications. Lack of experience for complications management without implant retrieval during early period might result in more revisions or fusion was done. Prosthetic factor: updated instrumentation decreased malalignment. If the polyethylene (PE) insert was significantly narrower than the metal components more implant instability and subsequent severe particulate wear was seen. Designs with flat-on-flat articulation and ridge at the center of the talar component associated with more PE fracture. Minimal bone resection reduced postoperative fractures. A flat cut of the tibial component and a flat undersurface with press-fit by two screws or pegs of the talar component demonstrated less postoperative fractures, whereas a syndesmosis fusion and a small triangular shape with one central fin of the talar component experienced more loosening which did not require additional surgery. Anatomic conical shape of the talar component seemed to reduce adjacent joint degeneration. Finally, fewer failures were found in patients who received HINTEGRA and Salto Talaris.

CONCLUSIONS

Based on our investigation, some positive and negative factors for different clinical and radiographic outcomes were found, which should be taken into consideration in clinical practice and ankle implant design.

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.

Comparison of 25 ankle arthrodeses and 25 replacements at 67 months' follow-up

INTRODUCTION

In the treatment of osteoarthritis of the ankle, controversy persists between advocates of arthrodesis and of joint replacement.

HYPOTHESIS

Results of total ankle replacement (TAR) are equivalent to those of ankle arthrodesis (AA).

MATERIAL AND METHODS

A single-center continuous retrospective series included 50 patients (25 TAR, 25 AA) operated on by a single surgeon. TAR used the standard Salto^® mobile-bearing prosthesis, and arthrodesis used screws or plates. Results were assessed clinically on AOFAS score, visual analog scale (VAS) and satisfaction questionnaire, and radiologically on X-ray and CT. Survivorship in the 2 procedures was estimated on the Kaplan Meier method.

RESULTS

At a mean 67 months' follow-up (range, 40-105 months), mean AOFAS and VAS scores were significantly better in the AA group (74.1 and 1.9, respectively) than in the TAR group (67 and 3.5, respectively) (p<0.001). In the AA group, 80% of patients were satisfied or very satisfied, compared to 64% after TAR. Five-year survival without revision for non-union (AA) or implant removal (TAR) was similar between groups: AA, 96%; TAR, 90% (p=0.72). In contrast, survival with no revision procedures was significantly better with AA (96%) than TAR (75%) (p=0.03).

DISCUSSION

At 5 years, surgical revision rates were significantly greater than after standard Salto^® mobile-bearing TAR than for arthrodesis, notably due to onset of cysts; we therefore decided to abandon this implant.

LEVEL OF EVIDENCE

IV, comparative retrospective study.