Clinical Outcome and Fusion Rate Following Simultaneous Subtalar Fusion and Total Ankle Arthroplasty

Influence of Isolated Talonavicular and Subtalar Joint Arthrodesis on Hindfoot Kinematics and Range of Motion During Cadaveric Gait Simulation

BACKGROUND

Isolated subtalar and talonavicular joint arthrodeses have been associated with adjacent joint arthritis and altered hindfoot kinematics during simplified loading scenarios. However, the effect on kinematics during dynamic activity is unknown. This study assessed changes in subtalar and talonavicular kinematics after isolated talonavicular (TNiso) and subtalar (STiso) arthrodesis, respectively, during stance simulations.

METHODS

Fourteen midtibia specimens received either a TNiso or STiso arthrodesis, with 7 randomized to each group. A 6-degree-of-freedom robot sequentially simulated the stance phase for the intact and arthrodesis conditions. Bootstrapped bias-corrected 95% CIs of the talonavicular and subtalar joint kinematics were calculated and compared between conditions.

RESULTS

The TNiso decreased subtalar inversion, adduction, and plantarflexion in late stance (P < .05). The subtalar range of motion in the sagittal and coronal planes decreased by 40% (P = .009) and 46% (P = .002), respectively. No significant changes in talonavicular joint kinematics were observed after isolated subtalar arthrodesis; however, the range of motion was reduced by 61% (P = .007) and 50% (P = .003) in the coronal and axial planes, respectively.

CONCLUSION

In this model for arthrodesis, changes in subtalar kinematics and motion restriction were observed after isolated talonavicular arthrodesis, and motion restriction was observed after isolated subtalar arthrodesis. Surprisingly, talonavicular kinematics did not appear to change after isolated subtalar arthrodesis.

CLINICAL RELEVANCE

Both joint fusions substantially decrease the motion of the reciprocal adjacent joint. Surgeons should be aware that the collateral costs with talonavicular fusion appear higher, and it has a significant effect on subtalar kinematics during the toe-off phase of gait.

Association of Timing of Hindfoot Arthrodesis and Early Reoperation Rates for Total Ankle Arthroplasty

BACKGROUND

Prior literature has demonstrated that ipsilateral hindfoot arthrodesis may increase the risk for reoperation after total ankle arthroplasty (TAA) and that simultaneous hindfoot arthrodesis with TAA could result in short-term clinical and radiologic improvements. The purpose of this study is to compare the reoperation rates after TAA with prior hindfoot arthrodesis vs simultaneous arthrodesis and TAA.

METHODS

Patients who underwent primary TAA were identified in the PearlDiver database. Patients were sorted into 2 study cohorts: hindfoot arthrodesis prior to TAA and simultaneous arthrodesis and TAA. Propensity matched control cohorts were identified for each study group. Multivariate analysis was conducted to account for any confounding variables and covariates when identifying differences in complications between cohorts.

RESULTS

297 patients underwent TAA with prior hindfoot arthrodesis and 174 underwent TAA and hindfoot arthrodesis concurrently. The incidence of reoperation (13.8% vs 5.2%, P < .001) and infection (12.6% vs 5.9%, P = .011) for the simultaneous cohort was higher when compared to the matched control cohort. In contrast, there was no statistically significant difference when comparing the prior arthrodesis cohort to the matched control cohort in reoperation rates (5.1% vs 4.7%, P = .787) or infection rates (4.4% vs 4.8%, P = .734). Those undergoing simultaneous procedures had increased incidences of reoperation, wound complications, infection, and emergency department visits (P < .0167) when compared to the TAA with prior arthrodesis cohort.

CONCLUSION

Patients undergoing TAA and hindfoot arthrodesis concurrently were found to have higher rates of reoperation and infection when compared to the matched control cohort . In contrast, there was no difference in these rates in patients undergoing TAA with prior hindfoot arthrodesis compared with their matched control cohort. Patients undergoing simultaneous procedures had increased rates of reoperations, wound complications, infection, and emergency department visits compared to the TAA with prior arthrodesis cohort.

Implant Choice May Reduce the Risk of Early Mechanical Failure in Total Ankle Replacement

BACKGROUND

Total ankle replacements (TARs) have rapidly advanced in terms of volume, technique, design, and indications. However, TARs are still at risk for early mechanical failure and revision. Prior studies have investigated potential risk factors for failure, but have been limited to smaller series or older implants. This study sought to identify risk factors for early mechanical failure in modern TAR.

METHODS

This is a retrospective study of a single-institution registry. Five surgeons contributed cases involving patients who underwent a primary TAR with any implant. Implants were grouped on the basis of the type of fixation. The primary outcome was early mechanical failure (revision with component removal for a non-infectious etiology, that is, subsidence, aseptic loosening, and/or malalignment). Logistic regression determined the effects of age, weight, hindfoot arthrodesis, implant type, and radiographic deformity on failure.

RESULTS

The 731 included patients had a mean follow-up of 2.7 years. Ten percent (71 patients) had hindfoot arthrodesis. There were 33 mechanical failures (4.5%) at a mean of 1.7 years after the index surgical procedure. Our model demonstrated that hindfoot arthrodesis was associated with 2.7 times greater odds of failure (p = 0.045), every 10 kg of body weight increased the odds of tibial-sided failure by 1.29 times (p = 0.039), and implants with more extensive tibial fixation (stems or keels) lowered the odds of tibial failure by 95% (p = 0.031).

CONCLUSIONS

In patients with uncontrollable risk factors (hindfoot arthrodesis) or risk factors that may or may not be modifiable by the patient (weight), implants with more robust tibial fixation may be able to reduce the risk of early mechanical failure. Further research is warranted to support efforts to decrease early failure in TAR.

LEVEL OF EVIDENCE

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

Hindfoot Arthrodeses and the Order of Joint Fixation Influence Tibiotalar Kinematics During Simulated Stance

BACKGROUND

Although hindfoot arthrodeses relieve pain and correct deformity, they have been associated with progressive tibiotalar degeneration. The objective was to quantify changes in tibiotalar kinematics after hindfoot arthrodeses, both isolated subtalar and talonavicular, as well as double arthrodesis, and to determine if the order of joint fixation affects tibiotalar kinematics.

METHODS

Hindfoot arthrodeses were performed in 14 cadaveric mid-tibia specimens. Specimens randomly received isolated fixation of the subtalar or talonavicular joint first, followed by fixation of the remaining joint for the double arthrodesis. A 6-degree-of-freedom robot sequentially simulated the stance phase of level walking for intact, isolated, and double arthrodesis conditions. Tibiotalar kinematic changes were compared for the intact and arthrodesis conditions. A subsequent analysis assessed the effect of the joint fixation order on tibiotalar kinematics.

RESULTS

Isolated and double hindfoot arthrodeses increased tibiotalar plantarflexion, inversion, and internal rotation during late stance. Tibiotalar kinematics changes occurring after isolated arthrodesis remained consistent after the double arthrodesis for both the subtalar- and talonavicular-first conditions. The order of joint fixation influenced tibiotalar kinematics through some portions of stance, where the talonavicular-first double arthrodesis increased tibiotalar plantarflexion, eversion, and internal rotation compared to the subtalar-first double.

CONCLUSION

Tibiotalar kinematics were modestly altered for all conditions, both isolated and double hindfoot arthrodeses. Changes in tibiotalar kinematics were consistent from the isolated to the double arthrodesis conditions and varied depending on which isolated hindfoot arthrodesis was performed first. Further research is needed to assess the clinical implications of the observed changes in tibiotalar kinematics, particularly as it pertains to the development of adjacent joint arthritis.

CLINICAL RELEVANCE

These findings may correlate with clinical research that has cited hindfoot arthrodesis as a risk factor for adjacent tibiotalar arthritis. Once either the subtalar or talonavicular joint is fused, avoiding the arthrodesis of the second joint may not necessarily protect the tibiotalar joint.

CT-Verified Union Rate Following Arthrodesis of Ankle, Hindfoot, or Midfoot: A Systematic Review

BACKGROUND

Ankle, hindfoot, and midfoot arthrodesis surgeries are standard procedures performed in orthopaedics to treat pain and functional disabilities. Although fusions can effectively improve pain and quality of life, nonunions remain a significant concern for surgeons. With the increased availability of computed tomography (CT), more surgeons rely on this modality for increased accuracy in determining whether a fusion was successful. The objective of this study was to report the rates of CT-confirmed fusion following ankle, hindfoot, or midfoot arthrodesis.

METHODS

A systematic review was performed using EMBASE, Medline, and Cochrane central register from January 2000 to March 2020. Inclusion criteria included studies with adults (<18 years) that received 1 or multiple fusions of the ankle, hindfoot, or midfoot. At least 75% of the study cohort must have been evaluated by CT postoperatively. Basic information was collected, including journal, author, year published, and level of evidence. Other specific information was collected, including patient risk factors, fusion site, surgical technique and fixation, adjuncts, union rates, criteria for successful fusion (%), and time of CT. Once data were collected, a descriptive and comparative analysis was performed.

RESULTS

Included studies (26, n = 1300) had an overall CT-confirmed fusion rate of 78.7% (69.6-87.7). Individual joints had an overall fusion rate of 83.0% (73-92.9). The highest rate of union was in the talonavicular joint (TNJ).

CONCLUSION

These values are lower than previous studies, which found the same procedures to have greater than 90% fusion rates. With these updated figures, as confirmed by CT, surgeons will have better information for clinical decision making and when having informed consent conversations.

Preoperative incongruent subtalar joint predicts less favorable clinical outcome in total ankle arthroplasty

BACKGROUND

This study aimed to determine the clinical effect of incongruent subtalar joint space on total ankle arthroplasty (TAA).

METHODS

Thirty-four consecutive patients who underwent TAA were grouped according to the status of subtalar joint incongruency. A comparison of clinical and radiographic parameters between groups as well as multiple regression analysis was performed to identify contributing factors to the final functional outcome.

RESULTS

The final American Orthopaedic Foot and Ankle Society (AOFAS) score was significantly higher in the congruent group compared to that of the incongruent group (p = 0.007). There were no significant differences between the two groups in measured radiographic angles. In multiple regression analysis, the female sex (p = 0.006) and incongruency of the subtalar joint (p = 0.013) were found to be significant contributing factors to the final AOFAS score.

CONCLUSIONS

A thorough preoperative investigation should be taken into the state of the subtalar joint for TAA.

Biomechanics and Tribology of Total Ankle Replacement

This article discusses the biomechanics and tribology of total ankle replacements considering the influence of implant design and generation on functional outcome, before discussing the interplay between biomechanics and tribology in the clinical success of total ankle replacement. It reflects on what we know and highlights areas for further research, as well as identifying factors to consider in clinical practice.

How to assess consolidation after foot and ankle arthrodesis with computed tomography. A systematic review

PURPOSES

Many studies have been performed that investigate consolidation after arthrodesis of foot and ankle joints. Consolidation in foot and ankle joints is best assessed by computed tomography (CT). However, no golden-standard methodology exists for radiological consolidation assessment from CT after ankle and foot arthrodesis. The aim of this review is to present an overview of the radiological methodologies for consolidation assessment, outcomes on reliability and validity and to advise which methodology should be used.

METHOD

Scientific databases were systematically searched. Eligible studies were studies that 1) performed foot or ankle arthrodesis, 2) mentioned radiological or CT follow-up in abstract, 3) performed postoperative CT in > 50% of patients. Two authors selected eligible studies and performed a risk of bias assessment with the COSMIN tool.

RESULTS

Risk of bias assessment showed that most studies (80%) were at high risk of bias due to poor methodology. The most popular method for consolidation assessment is by subjectively categorizing consolidation into consolidation groups, with a substantial reliability score. Another popular method is to calculate the fusion ratio and then apply a fusion threshold, to distinguish between fused and non-fused joints. This method had an excellent reliability score. In most studies a fusion threshold of 50% is used. However, four studies in this review showed that a 30% fusion threshold may by more valid.

CONCLUSION

Based on the results of this review we would advise to calculate fusion threshold and apply a 30% fusion threshold to distinguish fused from non-fused foot and ankle joints.

Cadaveric Gait Simulation of the Effect of Subtalar Arthrodesis on Total Ankle Replacement Kinematics

BACKGROUND

Patients undergoing total ankle replacement (TAR) often have symptomatic adjacent joint arthritis and deformity. Subtalar arthrodesis can effectively address a degenerative and/or malaligned hindfoot, but there is concern that it places abnormal stresses on the TAR and adjacent joints of the foot, potentially leading to early TAR failure. This study hypothesized that ankle and talonavicular joint kinematics would be altered after subtalar arthrodesis in the setting of TAR.

METHODS

Thirteen mid-tibia cadaveric specimens with neutral alignment were tested in a robotic gait simulator. To simulate gait, each specimen was secured to a static mounting fixture about a 6-degree of freedom robotic platform, and a force plate moves relative to the stationary specimen based on standardized gait parameters. Specimens were tested sequentially in TAR and TAR with subtalar arthrodesis (TAR-ST_fuse). Kinematics and range of motion of the ankle and talonavicular joint were compared between TAR and TAR-ST_fuse.

RESULTS

There were significant differences in kinematics and range of motion between TAR and TAR-ST_fuse groups. At the ankle joint, TAR-ST_fuse had less internal rotation in early-mid stance (P < .05), with decreased range of motion in the sagittal (-2.7 degrees, P = .008) and axial (-1.8 degrees, P = .002) planes in early stance, and increased range of motion in the coronal plane in middle (+1.2 degrees, P < .001) and late (+2.5 degrees, P = .012) stance. At the talonavicular joint, there were significant differences in axial and coronal kinematics in early and late stance (P < .05). Subtalar arthrodesis resulted in significantly decreased talonavicular range of motion in all planes in early and late stance (P < .003).

CONCLUSION

In ankles implanted with the TAR design used in this study, kinematics of the ankle and talonavicular joint were found to be altered after subtalar arthrodesis. Aberrant motion may reflect altered contact mechanics at the prosthesis and increased stress at the bone-implant interface, and affect the progression of adjacent joint arthritis in the talonavicular joint.

CLINICAL RELEVANCE

These findings may provide a correlate to clinical studies that have cited hindfoot arthrodesis as a risk factor for TAR failure.

Range of motion of foot joints following total ankle replacement and subtalar fusion

BACKGROUND

In severe cases of ankle and subtalar arthritis, arthrodesis of the subtalar joint is performed in combination with ankle arthroplasty. In these special cases gait analysis reveals real motion at the replaced tibiotalar joint.

METHODS

Twenty-three patients affected by ankle and subtalar arthritis, treated either with a 3-component or a 2-component prosthesis in combination with subtalar arthrodesis, were clinically evaluated preoperatively and at a minimum of 1-year follow-up. Gait analysis was performed postoperatively using a multi-segment foot protocol. Foot kinematics were compared to corresponding data from a healthy control group.

RESULTS

Clinical scores significantly improved from preoperative to follow-up. The clinically measured passive ankle dorsiflexion/plantarflexion significantly improved at the follow-up. Patients' normalized walking speed and stride length were significantly lower than those in control. With exception of the ankle frontal-plane motion, sagittal-plane mobility of foot joints was about 50% than that in healthy joints.

CONCLUSIONS

Improvement in clinical scores was found for both prostheses. Normal spatio-temporal parameters were not restored. In these patients, fusion of the subtalar joint appeared to be compensated by larger frontal-plane motion at the tibiotalar joint.

LEVEL OF EVIDENCE

Level III- retrospective comparative study. The study was approved by the local Ethics Committee as protocol MAT (protocol registration at clinicaltrials.gov NCT03356951).

Talus Fractures: Evaluation and Treatment

The talus is unique in having a tenuous vascular supply and 57% of its surface covered by articular cartilage. Fractures of the head, neck, or body regions have the potential to compromise nearby joints and impair vascular inflow, necessitating surgical treatment with stable internal fixation in many cases. The widely preferred approach for many talar neck and body fractures is a dual anterior incision technique to achieve an anatomic reduction, with the addition of a medial malleolar osteotomy as needed to visualize the posterior talar body. Percutaneous screw fixation has also demonstrated success in certain patterns. Despite this modern technique, osteonecrosis and osteoarthritis remain common complications. A variety of new treatments for these complications have been proposed, including vascularized autograft, talar replacement, total ankle arthroplasty, and improved salvage techniques, permitting some patients to return to a higher level of function than was previously possible. Despite these advances, functional outcomes remain poor in a subset of severely injured patients, making further research imperative.

Return to Sport After Arthroscopic Autologous Matrix-Induced Chondrogenesis for Patients With Osteochondral Lesion of the Talus

OBJECTIVE

To determine the rate of return of patients to sport after arthroscopic autologous matrix-induced chondrogenesis (AT-AMIC) for outcomes 2 years after surgery.

DESIGN

Retrospective observational cross-sectional study.

SETTING

C.A.S.C.O.-Foot and Ankle Unit, Istituto Ortopedico Galeazzi, Milan, Italy.

PATIENTS AND INTERVENTION

Twenty-six consecutive patients, 65.4% male (mean ± SD age: 33.7 ± 11.0 years), that underwent AT-AMIC procedure between 2012 and 2015 were selected retrospectively. From this population, only sporting patients at amateur's level were included. Arthroscopic autologous matrix-induced chondrogenesis was proposed in patients with pain and persistent disability.

MAIN OUTCOME MEASURES

All patients were assessed with the American Orthopaedic Foot and Ankle Score (AOFAS), physical component score of the 12-Item Short Form Health Survey (SF-12), Halasi ankle activity score, and University of California, Los Angeles (UCLA) activity scale preoperatively and at 24 months postoperatively.

RESULTS

Overall, 80.8% of the patient group returned to the same preinjury sport. The mean follow-up was 42.6 ± 10.9 months (range from 25 to 62 months). Significant differences were observed with reference to AOFAS, SF-12, Halasi, and UCLA scores at the last follow-up in patients who had undergone AT-AMIC (all, P < 0.001).

CONCLUSIONS

A high percentage of patients return to their preinjury sport after AT-AMIC surgery.

Total ankle arthroplasty and national registers: What is the impact on scientific production?

PURPOSE

The purpose of this systematic review was to analyze clinical studies on total ankle replacement (TAR) whose data were extracted from national registers.

METHODS

A systematic review of the literature, to identify all studies reporting outcomes after TAR, was performed. Two independent investigators performed the research using MEDLINE, CINAHL (Cumulative Index to Nursing and Allied Health Literature), Embase and Cochrane Databases (1950 to December 2017). The search terms used were "total ankle replacement" or "total ankle arthroplasty" AND "register" or "registers" or "registry" or "registries" or "national registry" or "national register".

RESULTS

Analysis of the literature included 18 articles from 2007 to 2017. Of these 5 articles performed a comprehensive analysis of the national registers, 5 articles evaluated complications and reasons of failure after TAR, 6 articles made a specific outcome register analysis, one article compared TAR and ankle arthrodesis while the last one analyzed the role of TAR in patients with rheumatoid arthritis.

CONCLUSIONS

Scientific publications extracted from national joint registers for total ankle replacement provide useful but heterogeneous information on implants survivorship, implant models and risk factors. There is still a discrepancy between the data reported by designers in clinical studies and the data reported by the registries. The centralization of registers in specialized hospitals with dedicated surgeons, the use of patient reported outcomes (PROMs) in association with surgeon assessments and periodical publications can improve the development of registries and consequently of the literature in this regard.

Total Replacement of Varus Ankle: Three-Component Prosthesis Design

In the past few decades, total ankle replacement (TAR) has become an increasingly recommended and accepted treatment in patients with end-stage ankle osteoarthritis. However, controversy still exists about the appropriate indications for TAR, specifically in ankles with coronal plane deformities. Although not explicitly proved, the long-term success of TAR seems to largely depend on the extent to which the surgeon is able to balance the ankle joint complex.

Inframalleolar Varus Deformity: Role of Calcaneal Osteotomies

The cavo varus foot is a complex pathology due to skeletal deformity and neuro-muscular unbalance. The key concept for a successful treatment is to consider the whole foot and ankle complex from a bone and soft tissue perspective. Undercorrection is the main issue in cavo varus foot management, which may be attributed to intrinsic correction defects of the described calcaneal osteotomies or to a lack of understanding about the pathology and the subsequent algorithm of treatment. The authors disclose their daily algorithm of treatment, considering the foot and ankle complex and the role of calcaneal osteotomies in ankle inframalleolar deformities.

Reliability of the Phi angle to assess rotational alignment of the talar component in total ankle replacement

BACKGROUND

The purpose of this study was to investigate the test-retest reliability of the Phi angle in patients undergoing total ankle replacement (TAR) for end stage ankle osteoarthritis (OA) to assess the rotational alignment of the talar component.

METHODS

Retrospective observational cross-sectional study of prospectively collected data. Post-operative anteroposterior radiographs of the foot of 170 patients who underwent TAR for the ankle OA were evaluated. Three physicians measured Phi on the 170 randomly sorted and anonymized radiographs on two occasions, one week apart (test and retest conditions), inter and intra-observer agreement were evaluated.

RESULTS

Test-retest reliability of Phi angle measurement was excellent for patients with Hintegra TAR (ICC=0.995; p<0.001) and Zimmer TAR (ICC=0.995; p<0.001) on radiographs of subjects with ankle OA. There were no significant differences in the reliability of the Phi angle measurement between patients with Hintegra vs. Zimmer implants (p>0.05).

CONCLUSIONS

Measurement of Phi angle on weight-bearing dorsoplantar radiograph showed an excellent reliability among orthopaedic surgeons in determining the position of the talar component in the axial plane.

LEVEL OF EVIDENCE

Level II, cross sectional study.

Hindfoot Arthrodesis Screw Position and Trajectory Effect on Talus Subsidence When Performed With Total Ankle Arthroplasty

BACKGROUND:

Total ankle arthroplasty (TAA) is increasingly being recognized as an effective surgical option for end-stage ankle arthritis. Associated hindfoot arthrodesis procedures are at times needed to correct malalignment or to address adjacent joint arthritis. Results following TAA and associated hindfoot arthrodesis have at times been underwhelming and the devascularization of the talar blood supply has been postulated as a potential cause. This study explored the association between hindfoot arthrodesis fixation and talar component subsidence.

METHODS:

The study included 81 consecutive patients who underwent a TAA with either an isolated subtalar arthrodesis or combined subtalar and talonavicular arthrodesis with a minimum of 2 years of follow-up. Radiographic and clinical evaluations including patient-reported outcomes were performed at each postoperative visit. The primary outcome measure was the presence of talar component subsidence while patient-reported outcomes were the secondary outcome measure.

RESULTS:

30.9% of patients had evidence of talar component subsidence. Subsidence was seen in 55.5% of patients with dorsal to plantar subtalar fixation compared to 11.1% of patients with plantar to dorsal screws ( P < .001) and in 44.4% of patients with screws violating the sinus tarsi compared to 3.7% of patients without screws in the sinus tarsi ( P < .001). Screws that were placed from dorsal to plantar were more likely to violate the sinus tarsi ( P < .001). Patients with evidence of talar subsidence reported higher pain scores and lower functional scores. There were 8 TAA failures, and the presence of dorsal to plantar screws was associated with failure ( P < .01).

CONCLUSION:

Screws that are placed across the subtalar joint from a dorsal to plantar approach are more likely to violate the sinus tarsi, contributing to a significantly higher rate of talar component subsidence when associated with TAA.

LEVEL OF EVIDENCE:

Level II, prospective comparative series.

Infections in primary total ankle replacement: Anterior approach versus lateral transfibular approach

BACKGROUND

Total ankle replacement (TAR) represents an alternative to fusion for the treatment of end-stage ankle osteoarthritis. The aim of the present study was to retrospectively assess the frequency of infections between TARs with anterior and lateral transfibular approach at 12-months follow-up.

METHODS

81 TARs through an anterior approach and 69 TARs through a lateral approach were performed between May 2011 and July 2015. We compared surgical time and tourniquet time, as well as superficial and deep infections frequency during the first 12 postoperative months.

RESULTS

In the anterior approach group, there were 3 (3.7%) deep infections and 4 (4.9%) superficial wound infections. In the lateral approach group, there were 1 (1.4%) deep infection and 2 superficial wound infections (2.9%). There were not statistically significant differences between the groups. There was a significant difference between anterior approach (115minutes) and lateral approach group (179minutes) in terms of surgical time (P<0.001).

CONCLUSIONS

The frequency of superficial and deep periprosthetic infections during the first postoperative year was not significantly different in the lateral approach group compared to the anterior approach group, despite the significantly longer surgical time in the lateral transfibular approach group.

Bone-block arthrodesis procedure in failures of first metatarsophalangeal joint replacement

BACKGROUND

The treatment for the failure of a first metatarsophalangeal joint (MTP1) prosthesis can be complex. There is no consensus regarding the ideal treatment. One of the main issues is the available bone stock after prosthesis removal. The aim of the study was to report the clinical and radiographic results for MTP1 arthrodesis with autologous calcaneus bone graft (bone-block fusion) as a revision procedure of a previous MTP1 implant failure.

METHODS

This study included 12 patients diagnosed with failure of a MTP1 prosthesis. All patients were treated with MTP1 arthrodesis using ipsilateral calcaneal bone graft. Patients were evaluated with the Foot Ankle Disability Index (FADI), the visual analogue pain scale (VAS) and AOFAS Hallux Metatarsophalangeal Interphalangeal scoring system (AOFAS-HMI), weight-bearing radiograph of the foot, and a computed tomography scan. The 1-2 intermetatarsal angle, hallux valgus angle, and first ray length were measured before surgery and at final follow-up.

RESULTS

Complications included 3 cases of arthrodesis nonunion, (1 symptomatic, 2 asymptomatic) with 2 of the 3 patients experiencing hardware failure and 1 superficial wound infection. The average FADI improved from 41.8 preoperatively to 84.6 at final follow-up (p<0.05); the average VAS improved from 8.5 preoperatively to 2 at final follow-up (p<0,05); the average AOFAS-HMI significantly improved from 50.7 preoperatively to 73.8 at final follow-up (p<0.05). The average length of the bone-block used was 14.3mm (range 11-19mm). The 1-2 intermetatarsal angle decreased from 9.5° preoperatively to 8.4° at final follow-up (p<0.05); hallux valgus angle improved from 19.7° preoperatively to 14.3° at final follow-up (p<0.05).

CONCLUSIONS

The management of a failed first metatarsophalangeal joint prosthesis remains controversial. Bone-block arthrodesis using ipsilateral calcaneal autograft appears to be a viable option restoring the bone loss, and avoiding hallux shortening. Nonunion is the most frequent complication with 25% of patients affected, but only 1/3 of patients with nonunion were symptomatic and required revision.

Patient selection for total ankle arthroplasty

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

Pearls and Pitfalls for a Surgeon New to Ankle Replacements

The role of the surgeon learning curve in total ankle replacement (TAR) has produced contradictory results. It is important for a new surgeon to know what clinical and radiological parameters are considered reliable and ideal. It is clear that exposure to a high-volume center will increase the reliability of a new surgeon approaching TAR. Implant choice may be influenced by surgeon training, and the debate of mobile versus fix-bearing prosthesis is still open. Anterior versus lateral approach is still an open debate, with any hypothetical advantages given by the direct vision on the center of rotation to be proven.

Malalignment Correction of the Lower Limb Before, During, and After Total Ankle Arthroplasty

One of the main challenges in ankle replacement is correction of any deformities in the operative limb. Deformity can be found proximal and distal to the ankle joint as well as in the ankle joint. There are static and dynamic deformities that can create unbalanced ankle joints causing early and often catastrophic failure. Surgeons must recognize the deformities that are present and use sound judgment to balance the ankle joint with procedures before, during, or after total ankle implantation. This article helps clinicians to identify deformity and provides a basic template to consider how to address each challenge.

A Review of 399 Total Ankle Replacements: Analysis of Ipsilateral Subtalar Joint Arthrodesis and Associated Talar Component Subsidence

Total ankle replacement (TAR) is an accepted treatment for end-stage ankle arthritis. When concurrent subtalar joint pathologic features exist, ipsilateral subtalar joint arthrodesis (STJA) can be performed either simultaneous with TAR or as a staged procedure. Limited data exist on the effect of talar component subsidence and prosthesis survivorship. The present study purpose was to evaluate the effect of STJA on talar component subsidence after primary TAR and its effect on TAR survivorship. All patients, a minimum of 18 years old, from a single institution with modern-generation TAR and 1-year minimum follow-up data available were evaluated. The study group included patients who had also undergone STJA, and the control group (no STJA) was matched 1:1 by age, gender, and prosthesis. The initial postoperative weightbearing and most recent weightbearing radiographs were compared for talar component subsidence. We reviewed 399 primary TARs from 2004 to 2012. A total of 33 patients with ipsilateral STJA met the inclusion criteria and had an appropriate control group match. In the study group, 8 patients required a return to the operating room for 4 revisions and 4 reoperations at a median follow-up point of 24.3 months. Of the controls, 9 patients required a return to the operating room, with 4 revisions and 5 reoperations at a median follow-up point of 38.4 months. No statistically significant radiographic differences were found between the 2 groups. Primary TAR and ipsilateral STJA were infrequently required (41 of 399; 10.3%). TAR did not result in decreased survivorship when performed with ipsilateral STJA at an early follow-up point. Further study is warranted to determine any differences among previous, simultaneous, and subsequent STJA with ipsilateral TAR, and a matched longitudinal analysis is needed to determine longer term survivorship.