Survival and risk assessment in revision arthroplasty of the ankle.

Aims: Implant failure has become more common as the number of primary total ankle arthroplasties (TAAs) performed has increased. Although revision arthroplasty has gained attention for functional preservation, the long-term results remain unclear. This study aimed to assess the long-term outcomes of revision TAA using a mobile-bearing prosthesis in a considerably large cohort; the risk factors for failure were also determined. Methods: This single-centre retrospective cohort study included 116 patients (117 ankles) who underwent revision TAA for failed primary TAA between July 2000 and March 2010. Survival analysis and risk factor assessment were performed, and clinical performance and patient satisfaction were evaluated preoperatively and at last follow-up. Results: The mean duration from initial revision TAA to last follow-up was 15.0 years (SD 3.0; 11.2 to 20.5). The cumulative survival rates of the revised ankles were 81% (95% confidence interval (CI) 74% to 88%), 74% (65% to 82%), and 70% (61% to 79%) at five, ten, and 15 years, respectively. Comorbidities prior to primary TAA, aseptic loosening, instability, or grafting of cysts were found to be the most common risk factors for secondary revision. The median value for preoperative pain, as assessed using the visual analogue scale, declined from 6 (interquartile range (IQR) 5 to 8) to 2 (IQR 0 to 5) (p < 0.001) and the mean American Orthopaedic Foot and Ankle Society ankle-hindfoot score improved from 43 (SD 17) preoperatively to 70 (SD 20) (p < 0.001) at last follow-up. Conclusion: Revision TAA offers acceptable survival rates after 15 years; it therefore offers a valuable option for treatment of implant failure in carefully selected cases. Although patient-reported outcomes improve substantially, the degree of improvement reported following primary TAA is not achieved.

How Does a Novel In Situ Fixed-bearing Implant Design Perform in Revision Ankle Arthroplasty in the Short Term? A Survival, Clinical, and Radiologic Analysis.

BACKGROUND: Given the growing number of primary total ankle replacements (TAR), an increase in the number of patients undergoing subsequent revisions might be expected. Achieving a stable and balanced ankle while preserving the remaining bone stock as much as possible is crucial for success in revision TAR. Most reported techniques rely on bulky implants with extended fixation features. Since 2018, we have used a novel, three-component ankle prosthesis for revision that is converted in situ to a fixed-bearing, two-component ankle prosthesis once the components have found their position according to an individual's anatomy. The results of this novel concept (fixation, revision, pain, or function) have not, to our knowledge, been reported. QUESTIONS/PURPOSES: What are the short-term results with this new revision TAR design, in terms of (1) repeat revision surgery, (2) patient-reported outcomes on the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, (3) pain according to the VAS, and (4) radiographic signs of fixation? METHODS: Between February 2018 and February 2020, we performed 230 TAR surgeries (in 206 patients) for any indication in our clinic. The novel semiconstrained, uncemented Hintermann Series H2 © implant was used in 96% (220 of 230) of procedures (201 patients). Fifty-four percent (119 of 220) of these were converted from an existing TAR to H2, which was the focus of the present study. However, only 45% (54 of 119) of these conversions to H2 were eligible for analysis. These patients had a mean age of 63 ± 12 years, and 43% (23 of 54) were women. The median (range) follow-up time was 3.2 years (2.0 to 4.3). The H2 design allows in situ conversion to a fixed-bearing system, with minimal bone resection. It achieves translational and rotational stability while preserving function and supporting the periarticular soft tissues. We defined repeat revision as exchange of one or both metal components, ankle fusion, or amputation and assessed it using a cumulative incidence survivorship estimator. Factors potentially associated with revision were assessed using Cox regression analyses. Clinical and radiologic outcomes were assessed preoperatively and at the most recent follow-up interval. Clinical outcomes included pain on the VAS (average pain during normal daily activity during the past seven days) and AOFAS score. Radiologic outcomes were the tibial articular surface angle, tibiotalar surface angle, talar tilt angle in the coronal plane, and AP offset ratio in the sagittal plane, as well as radiolucent lines and radiographic signs of loosening, defined as change in position greater than 2° of the flat base of the tibia component in relation to the long axis of the tibia, subsidence of the talar component into the talus greater than 5 mm, or change in position greater than 5° relative to a line drawn from the top of the talonavicular joint to the tuberosity of the calcaneus, as seen on plain weightbearing radiographs. RESULTS: The cumulative incidence of repeat revision after 1 and 2 years was 5.6% (95% CI 0% to 11%) and 7.4% (95% CI 0% to 14%), respectively. With the numbers available, no clinical factors we analyzed were associated with the risk of repeat revision. The median values of all assessed clinical outcomes improved; however, not all patients improved by clinically important margins. The median (range) AOFAS ankle-hindfoot score increased (from 50 [16 to 94] to 78 [19 to 100], difference of medians 28; p < 0.01), and the median pain on the VAS decreased (from 5 [0 to 9] to 2 [0 to 9], difference of medians 3; p < 0.01) from before surgery to follow-up at a minimum of 2 years. Radiographically, lucency was seen in 12% (6 of 49 patients) and loosening was seen in 8% (4 of 49). One of these patients showed symptomatic loosening and was among the four patients overall who underwent revision. We could not assess risk factors for repeat revision because of the low number of events (four). CONCLUSION: The investigated new in situ fixed-bearing ankle design achieved overall better short-term results than those reported in previous research. Destabilization of the ankle joint complex, soft tissue insufficiency, and possible changes of the joint configuration need an optimal solution in revision arthroplasty. The studied implant might be the answer to this complex issue and help surgeons in the perioperative decision-making process. However, a relatively high percentage of patients did not achieve a clinically important difference. Observational studies are needed to understand long-term implant behavior and possibly to identify ankles benefiting the most from revision. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Mid- to long-term outcome in patients treated with a mini-open sinus-tarsi approach for calcaneal fractures.

BACKGROUND: While the extended lateral approach was the gold standard for treatment of calcaneal fractures for decades, the mini-open approach through the sinus tarsi gained popularity in recent years. Although widely used, there are only a few reports available in the literature reporting on mid- to long-term results. Therefore, the purpose of the study was to report on mid- to long-term radiographic and clinical outcomes of calcaneal fractures treated surgically using a mini-open sinus tarsi approach. MATERIALS AND METHODS: In this retrospective review, radiographic and clinical outcome measures of 30 consecutive patients (34 fractures) were analyzed. Conventional radiographs were used to measure the Boehler's angle before and after surgical fixation. Computed tomography (CT) scans were analyzed to distinguish between joint depression and tongue-type calcaneal fractures. Each calcaneal fracture was additionally categorized according to the Sanders classification. The clinical outcome was measured using a 5-point Likert scale ranging from 0 (very unsatisfied) to 4 (very satisfied), the Visual Analog Scale (VAS) for pain, and the Maryland Foot Score. RESULTS: The Boehler's angle improved from 12.6 degrees preoperatively to 26.3 degrees postoperatively (P < 0.001). Loss of sagittal reduction (i.e., a decline of the Boehler's angle of > 5 degrees) from postoperative to the last follow-up was evident in nine (26%) fractures. Out of 29 patients with an available satisfaction score, 20 (69%) were very satisfied, 8 (28%) were satisfied, and one (3%) was moderately satisfied. Satisfaction at the last follow-up declined with higher age at surgery. An overall low complication rate was evident, with painful hardware needing removal being the most common complication. CONCLUSIONS: Approaching calcaneus fractures through the sinus tarsi provides satisfactory mid- to long-term radiographic and clinical outcomes, independent of the severity of the fractures according to the Sanders classification. LEVEL OF EVIDENCE: Level IV, Retrospective Case Series.

Ankle Range of Motion Following 3-Component Total Ankle Arthroplasty.

BACKGROUND: Although surgeons have argued that preserving motion at the level of the ankle joint may be crucial for the long-term success in the treatment of end-stage ankle osteoarthritis, there is little evidence regarding the potential of total ankle arthroplasty (TAA) to increase ankle range of motion (ROM). In addition, the effect of a percutaneous heel cord lengthening (HCL) during TAA on ankle motion is poorly understood. METHODS: A total of 357 primary TAAs treated with a 3-component device (336 patients, mean age 62.6 [24-85] years) performed between May 2003 and November 2017 were retrospectively analyzed. Sagittal ankle ROM was assessed according to a previously published protocol preoperatively (PreOP), 1 year postoperatively (PostOP), and at the last available follow-up (LastFU). Pain assessed on a visual analog scale (VAS) was assessed at the same time points. The effect of a percutaneous HCL on ankle ROM and VAS for pain was also evaluated. RESULTS: Preoperative ankle ROM increased from mean 31.3 (0-69) to 33.9 (5-65) degrees 1 year postoperatively (P = .0002) and decreased to 31.9 (5-70) degrees at the LastFU (P = .007). Percutaneous HCL showed no effect on ankle ROM development after TAA (P = .141). Ankle ROM improvement after TAA (PreOP to LastFU) was higher in ankles with lower preoperative ankle motion (P < .0001). A lower ankle ROM at the last follow-up tended to be associated with a higher pain level (P = .056). CONCLUSION: Although ankles with a lower preoperative sagittal ROM gained motion, the current data suggest that TAA has little potential to increase the preoperative available ankle motion. In some patients with a high preoperative ankle ROM, a slight decrease of ankle motion was observed postoperatively. Patients with limited ankle motion at long-term follow-up tended toward experiencing higher pain levels. The short- and long-term effect of a percutaneous HCL on ankle ROM following TAA was minimal. LEVEL OF EVIDENCE: Level III, retrospective comparative series.

Hindfoot balancing in total ankle replacement: the role of supramalleolar osteotomies.

PURPOSE: To compare the obtained deformity correction and clinical/functional outcomes between patients who underwent total ankle replacement (TAR) with or without a concurrent supramalleolar osteotomy (SMO) to address a varus and/or recurvatum deformity of the distal tibia. METHODS: Data of 23 patients treated with an additional SMO to correct a varus and/or recurvatum deformity of the distal tibia at the time of TAR were prospectively collected. Twenty-three matched patients who underwent TAR only served as controls. RESULTS: The American Orthopaedic Foot and Ankle Society (AOFAS)-hindfoot scale and pain assessed on a Visual Analogue Scale (VAS) did not significantly differ between the two groups at the final follow-up (AOFAS-hindfoot scale SMO/TAR group = 82 ± 10; TAR group = 82 ± 12; VAS pain SMO/TAR group = 1 (range, 0-4); TAR group = 1 (range, 0-5)). Ankle range of motion (ROM) did not improve in the SMO/TAR group (pre-operative = 27 ± 13 degrees, last follow-up = 30 ± 9 degrees; P = .294), but did improve in the TAR group (pre-operative = 31 ± 14 degrees, last follow-up = 39 ± 14 degrees; P = .049). Two patients who underwent SMO/TAR showed non-union of the tibial osteotomy, and two patients who underwent TAR only suffered from an intra-operative medial malleolar fracture. CONCLUSION: An additional SMO during TAR in patients with a varus and/or recurvatum deformity of the distal tibia is not beneficial in most cases and should only be considered in pronounced multiplanar deformities.

Effect of age on outcome and revision in total ankle arthroplasty.

AIMS: To assess the effect of age on clinical outcome and revision rates in patients who underwent total ankle arthroplasty (TAA) for end-stage ankle osteoarthritis (OA). METHODS: A consecutive series of 811 ankles (789 patients) that underwent TAA between May 2003 and December 2013 were enrolled. The influence of age on clinical outcome, including the American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score, and pain according to the visual analogue scale (VAS) was assessed. In addition, the risk for revision surgery that includes soft tissue procedures, periarticular arthrodeses/osteotomies, ankle joint debridement, and/or inlay exchange (defined as minor revision), as well as the risk for revision surgery necessitating the exchange of any of the metallic components or removal of implant followed by ankle/hindfoot fusion (defined as major revision) was calculated. RESULTS: A significant improvement in the AOFAS hindfoot score and pain relief between the preoperative assessment and the last follow-up was evident. Age had a positive effect on pain relief. The risk for a minor or major revision was 28.7 % at the mean follow-up of 5.4 years and 11.0 % at a mean follow-up of 6.9 years respectively. The hazard of revision was not affected by age. CONCLUSION: The clinical outcome, as well as the probability for revision surgery following TAA, is comparable between younger and older patients. The overall revision rate of the Hintegra total ankle is comparable with other three component designs. TAA should no longer be reserved for low demand elderly patients, but should also be recognized as a viable option for active patients of younger age. Cite this article: Bone Joint J 2020;102-B(7):925-932.

An excellent 5-year survival rate despite a high incidence of distal femoral cortical hypertrophy in a short hip stem.

BACKGROUND: Although reported results on short stems sound very promising, the occurrence of distal femoral cortical hypertrophy is often observed. The aim of the present study was to report 5-year survival data of a commercially available trochanter sparing short stem and investigate the clinical impact of distal femoral cortical hypertrophy on the outcome. METHODS: 123 total hip arthroplasties were performed on 120 patients from April 2008 to May 2010 (mean age 62, range 29-89 years; 71 hips from male patients, 58%). Clinical and radiological data were collected preoperative, at 6 weeks, 1, 2, 3, and 5 years postoperative to assess the outcome. Radiographs taken immediately postoperative as well as 1 and 5 years postoperative were used to identify and assess cortical hypertrophy. RESULTS: 1 stem had to be revised due to aseptic loosening, resulting in a Kaplan-Meier survival analysis with endpoint for stem revision of 99.2% (95% Confidence Interval 94.1-99.9) at 5 years. 96 radiological and 95 clinical follow-ups were analysed 5 years postoperative. 68 (71%) hips showed distal femoral cortical hypertrophy after 5 years. The average Harris Hip Score and Oxford Hip Score improved 33 (standard deviation (SD) 15.1, range 2-70), 18 (SD 12.1, range -10-43) points, respectively. Overall 16% of the patients reported thigh pain, unrelated to the presence of cortical hypertrophy. DISCUSSION: This short stem shows an excellent 5-year survival rate and good clinical outcome despite a high incidence of cortical hypertrophy. However, the question of the mechanism of load transfer arises.

Secondary Subtalar Joint Osteoarthritis Following Total Ankle Replacement.

BACKGROUND: An advantage of total ankle replacement (TAR) compared to ankle fusion is that by maintaining motion, the occurrence of hypermobility of adjacent joints may be prevented. This could affect the development of symptomatic subtalar joint osteoarthritis (OA). The aim of the study was to determine the incidence of subtalar joint fusion and the progression of subtalar joint OA following TAR. METHODS: Secondary subtalar joint fusion rate was determined from a cohort of 941 patients receiving primary TAR between 2000 and 2016. The indication for fusion, the time interval from primary TAR to fusion, and the union rate were evaluated. To assess the progression of subtalar joint OA, degenerative changes of the subtalar joint were classified in 671 patients using the Kellgren-Lawrence score (KLS) prior to TAR and at latest follow-up. RESULTS: In 4% (37) of the patients, a secondary subtalar joint fusion was necessary. The indication for fusion was symptomatic OA in 51% (19), hindfoot instability in 27% (10), osteonecrosis of the talus in 19% (7), and cystic changes of the talus in 3% (1) of the patients. Time from primary TAR to subtalar joint fusion due to progressive OA was 5.0 (range, 0.3-10) years and for other reasons 1.6 (range, 0.2-11.6) years (P = .3). In 68% (456) of the patients, no progression of subtalar joint OA was observed. CONCLUSION: The incidence of secondary subtalar joint fusion was low. The most common reason for subtalar joint fusion following TAR was symptomatic OA. LEVEL OF EVIDENCE: Level IV, case series.

Vascularized Bone Autograft for the Treatment of Chondroblastoma of the Talus at Imminent Risk of Joint Breakdown: Three Case Reports.

Surgical treatment options in a chondroblastoma of the talus breaching the subchondral layer with imminent risk of talar collapse in the weightbearing area are limited. A joint-preserving surgery should be advocated. Because current treatment options such as curettage, cryosurgery, or radiofrequency ablation may not be able to prevent a talar dome breakdown in large defects, nonvascularized bone grafting has been advocated to fill the void. To overcome the lack of vitality, a vascularized bone autograft might be an attractive alternative. We present 3 cases where a large talar defect owing to a chondroblastoma was treated with a vascularized bone autograft. In 1 of the cases, a free microvascular iliac crest bone graft was used, whereas in the other 2 cases, a vascularized graft was harvested from the medial femoral condyle. Computed tomographic scans demonstrated a stable incorporation of the graft in all cases. All patients were highly satisfied with the obtained results and showed a clinical functional outcome similar to the contralateral foot after 36, 60, and 72 months. At the latest radiographic follow-up, no evidence of recurrence was observed. In conclusion, a free vascularized bone autograft can be used to treat a large talar defect owing to chondroblastoma in young patients.

The subtalar joint: A complex mechanism.

Subtalar joint anatomy is complex and can vary significantly between individuals.Movement is affected by several adjacent joints, ligaments and periarticular tendons.The subtalar joint has gained interest from foot and ankle surgeons in recent years, but its importance in hindfoot disorders is still under debate.The purpose of this article is to give a general overview of the anatomy, biomechanics and radiographic assessment of the subtalar joint.The influence of the subtalar joint on the evolution of ankle joint osteoarthritis is additionally discussed. Cite this article: EFORT Open Rev 2017;2:309-316. DOI: 10.1302/2058-5241.2.160050.

Isolated talonavicular fusion with tension band for Müller-Weiss syndrome.

BACKGROUND: There are still controversies with regard to the operative treatment in advanced Müller-Weiss syndrome (MWS), where the navicular undergoes avascular necrosis and the talonavicular (TN) joint becomes arthritic. Most authors advocate extended fusion, sacrificing hindfoot mobility. To restore TN alignment and to achieve stable fixation, we developed a new isolated TN fusion technique applying the principles of a static tension band. The aim of the present study was to report the midterm results of a preliminary series of patients and their clinical and radiographic outcomes. METHODS: Ten feet (10 patients; 8 females, 2 males; age 63 ± 16.7 [range, 34-83] years) with advanced deformity of MWS (3 Maceira's stage III and 7 stage IV) were treated with isolated TN arthrodesis using the tension band technique. The American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score was used to evaluate the functional outcome. Standard angles were measured to determine the amount of correction achieved through the operative treatment. The minimum follow-up was 24 (range, 24-43) months. RESULTS: Trabeculation was seen to cross the fusion site on radiographs in 8 patients after 2 and in 1 patient after 3 months. One case needed revision after 13 months due to implant failure; after additional screw fixation, bony healing was achieved 2 months later. At last follow-up, all cases described a high level of satisfaction. Postoperatively, the AOFAS score improved from 33 (range, 18-48) to 88.3 (range, 79-100) (P < .0001) points, the AP talocalcaneal angle increased from 14.2 (range, 1-22) to 22.7 (range, 12-30) degrees (P = .0007), and the calcaneal pitch increased from 10.3 (range, 3-22) to 14.7 (range, 8-22) degrees (P = .0006). CONCLUSION: The static tension band technique is a new, promising technique to treat MWS patients, providing stability against the counteracting deforming forces. Therefore, we consider this technique as our treatment of choice in patients with stage III and stage IV MWS. LEVEL OF EVIDENCE: Level IV, prospective case series.

Subtalar joint configuration on weightbearing CT scan.

BACKGROUND: Standard values that describe the morphology of the subtalar (ST) joint have previously been obtained from cadaveric studies or by using conventional unloaded radiographs. It is known that these parameters differ significantly from those measured in vivo and in loaded images, limiting the diagnostic value of the previously published morphological parameters in the literature. However, the morphology of the ST joint clearly affects its function. The objective of this study was to determine the morphology of the posterior facet of the ST joint using loaded computed tomography (CT) images and to describe the different configurations found in asymptomatic patients. METHODS: A weightbearing CT scan was performed on 59 patients without any history of hindfoot and ankle pathology. The shape of the posterior facet and the subtalar vertical angle (SVA) were measured in 3 different coronal planes of the ST joint. RESULTS: The posterior facet was concave in 88% and flat in 12%. The posterior facet was oriented in valgus in 90% and varus in 10% when measured in the middle coronal plane. However, the SVA changed depending on which coronal plane it was measured in. CONCLUSION: We believe it is important to get a better insight into the morphological parameters of the ST joint. CLINICAL RELEVANCE: Knowledge of subtalar joint morphology could help clarify why certain failures have occurred in reconstructive hindfoot surgery and thus might help plan the surgical procedure to reduce these failures in the future.

Effect of supramalleolar osteotomy and total ankle replacement on talar position in the varus osteoarthritic ankle: a comparative study.

BACKGROUND: In varus osteoarthritic ankles, joint congruency is usually lost leading to progressive wear of the medial tibiotalar joint. Recent studies have shown that balancing the hindfoot with the aid of supramalleolar osteotomy (SMOT) is an effective method to decrease symptoms and to delay progression of osteoarthritis of the ankle joint. Resurfacing the articular surfaces with total ankle replacement (TAR), in contrast, may compensate for the lost joint congruency and lost stability of the talus at the peritalar joint. However, no literature exists with regard to the overall correction of talar position in all 3 planes when using these 2 treatment modalities. The purpose of this study was to determine the effect of SMOT and TAR on talar position in all 3 planes, and to compare the efficiency of both procedures in restoring overall hindfoot geometry. METHODS: Out of 104 ankles with a varus-tilted ankle, 52 patients were treated with SMOT and 52 with TAR. Weight-bearing radiographs were analyzed to measure the talar position in all 3 planes, including the talar tilt angle (TT), the sagittal talocalcaneal inclination angle (TCI), and the talometatarsal 1 angle (TMT1) pre- and postoperatively. RESULTS: Although after TAR the talar position was corrected in all the 3 planes, SMOT on the other hand did not fully correct the TT, and furthermore TMT1 remained unchanged. CONCLUSIONS: Resurfacing of the worn-out articular surface and tensioning of ligaments, as is the case in TAR, radiographically restores the hindfoot geometry in the neutral position better than SMOT does. LEVEL OF EVIDENCE: Level III, retrospective comparative study.