Pre- and postoperative gait analysis following conversion of tibiotalocalcaneal fusion to total ankle arthroplasty

Outcomes of Ankle Arthrodesis Conversion to Total Ankle Arthroplasty: A Systematic Review

Ankle arthrodesis (AA) provides reliable pain relief, good patient satisfaction scores, and improved overall function. However, this procedure has been associated with numerous complications and sequelae, such as pseudoarthrosis, malunion, gait abnormalities, increased demand on surrounding joints, and a long period of convalescence. Conversion to total ankle arthroplasty (TAA) is a potential option in the management of these complex and challenging situations. The purpose of this study is to investigate the outcomes of AA conversion to TAA. A systematic review of electronic databases was performed. Six studies involving 172 ankles met inclusion criteria. The weighted mean preoperative Visual Analogue Scale (VAS) score at the time of TAA conversion was 7.8 and the weighted mean postoperative VAS score at the time of final follow-up was 2.5. The weighted mean preoperative AOFAS score at the time of TAA conversion was 32 and the weighted mean postoperative AOFAS score at the time of final follow-up was 72.4. The rate of salvage tibiotalocalcaneal arthrodesis was 2.3% and rate of transtibial amputation was also 2.3% after attempted conversion from initial AA to TAA. Conversion of AA to TAA appears to be a viable option to improve patient outcomes and prevent extensive hindfoot arthrodesis and transtibial amputation. More prospective studies with consistent reporting of outcomes, complications, and revision rates with long-term follow-up are needed.

Converting Ankle Arthrodesis to a Total Ankle Arthroplasty

Several articles in the literature discuss the positive results of converting a painful ankle fusion to an ankle replacement. Our results confirm that in well-selected cases a conversion to a total ankle replacement is not only possible, but also significantly improves quality of life and reduces pain. The outcome of a total ankle replacement after an ankle fusion depends to a degree on the method of fusion. Less destructive fusion that is arthroscopic has better results than conventional transfibular open fusions. Absence of a fibula should be an absolute contraindication for a conversion.

Multisegment Foot Models and Clinical Application After Foot and Ankle Trauma: A Review

Since the end of the 1990s, several multisegment foot models (MSFMs) have been developed. Several models were used to describe foot and ankle kinematics in patients with foot and ankle pathologies; however, the diagnostic value for clinical practice of these models is not known. This review searched in the literature for studies describing kinematics in patients after foot and ankle trauma using an MSFM. The diagnostic value of the MSFMs in patients after foot and ankle trauma was also investigated. A search was performed on the databases PubMed/MEDLINE, Embase, and Cochrane Library. To investigate the diagnostic value of MSFMs in patients after foot and ankle trauma, studies were classified and analyzed following the diagnostic research questions formulated by Knottnerus and Buntinx. This review was based on 7 articles. All studies were published between 2010 and 2015. Five studies were retrospective studies, and 2 used an intervention. Three studies described foot and ankle kinematics in patients after fractures. Four studies described foot and ankle kinematics in patients after ankle sprain. In all included studies, altered foot and ankle kinematics were found compared with healthy subjects. No results on patient outcome using MSFMs and costs were found. Seven studies were found reporting foot and ankle kinematics in patients after foot and ankle trauma using an MSFM. Results show altered kinematics compared with healthy subjects, which cannot be seen by other diagnostic tests and add valuable data to the present literature; therefore, MSFMs seem to be promising diagnostic tools for evaluating foot and ankle kinematics. More research is needed to find the additional value for MSFMs regarding patient outcome and costs.

Conversion of painful tibiotalocalcaneal arthrodesis to total ankle replacement using a 3-component mobile bearing prosthesis

BACKGROUND

The aim of this study was to assess the short-term clinical and radiographic outcomes in patients who underwent conversion of a painful tibiotalocalcaneal arthrodesis to a total ankle replacement.

METHODS

Six patients with painful ankle arthrodesis after tibiotalocalcaneal arthrodesis were included in this study. In all patients, conversion to total ankle replacement was performed using a 3^rd-generation, non-constrained, cementless three-component prosthesis. The outcomes were analyzed at a mean follow-up of 3.4±1.9years (range 1.0-6.5).

RESULTS

One patient with painful arthrofibrosis underwent two open arthrolysis procedures at 1.2 and 5.6 years post index surgery, respectively. No revision of tibial or talar prosthesis components was necessary in this study. All patients reported significant pain relief and significant improvement in functional status.

CONCLUSION

In the present study, the conversion of a painful ankle arthrodesis following tibiotalocalcaneal arthrodesis to a total ankle replacement was a reliable surgical treatment.

Comparison of Multisegmental Foot and Ankle Motion Between Total Ankle Replacement and Ankle Arthrodesis in Adults

BACKGROUND

Total ankle replacement (TAR) and ankle arthrodesis (AA) are usually performed for severe ankle arthritis. We compared postoperative foot segmental motion during gait in patients treated with TAR and AA.

METHODS

Gait analysis was performed in 17 and 7 patients undergoing TAR and AA, respectively. Subjects were evaluated using a 3-dimensional multisegmental foot model with 15 markers. Temporal gait parameters were calculated. The maximum and minimum values and the differences in hallux, forefoot, hindfoot, and arch in 3 planes (sagittal, coronal, transverse) were compared between the 2 groups. One hundred healthy adults were evaluated as a control.

RESULTS

Gait speed was faster in the TAR ( P = .028). On analysis of foot and ankle segmental motion, the range of hindfoot sagittal motion was significantly greater in the TAR (15.1 vs 10.2 degrees in AA; P = .004). The main component of motion increase was hindfoot dorsiflexion (12.3 and 8.6 degrees). The range of forefoot sagittal motion was greater in the TAR (9.3 vs 5.8 degrees in AA; P = .004). Maximum ankle power in the TAR (1.16) was significantly higher than 0.32 in AA; P = .008). However, the range of hindfoot and forefoot sagittal motion was decreased in both TAR and AA compared with the control group ( P = .000).

CONCLUSION

Although biomechanical results of TAR and AA were not similar to those in the normal controls, joint motions in the TAR more closely matched normal values. Treatment decision making should involve considerations of the effect of surgery on the adjacent joints.

LEVEL OF EVIDENCE

Level III, case-control study.

Can a Three-Component Prosthesis be Used for Conversion of Painful Ankle Arthrodesis to Total Ankle Replacement?

BACKGROUND

In patients with painful ankle arthrodesis, the surgical treatment is challenging, and may include takedown of ankle arthrodesis and conversion to a total ankle replacement (TAR). This procedure is technically demanding given the altered anatomy after arthrodesis. Few studies have evaluated TAR in the setting of prior arthrodesis.

QUESTIONS/PURPOSES

(1) What intraoperative and perioperative complications were observed in patients who underwent conversion of an ankle arthrodesis to a TAR? (2) Was durable fixation achieved at short term, and what was the alignment of the components? (3) What subsequent surgical procedures were performed, including revisions? (4) What improvements were observed in pain, tibiotalar range of motion (ROM), and quality of life?

METHODS

Between January 2007 and December 2014, 18 patients with a painful ankle arthrodesis underwent conversion to TAR at our tertiary referral center. During this period, the indications for conversion of ankle arthrodesis to TAR were tibiotalar nonunion or malunion after attempted arthrodesis in patients who declined revision ankle arthrodesis. The goal of revision surgery was to help patients regain hindfoot mobility and to decrease pain. During the study period, all patients who met indications were treated with a conversion procedure. Of the 18 patients included, 14 were men and four were women. The mean age of the patients was 51 ± 7 years. The mean followup was 54 ± 27 months, with no loss to follow up observed. The initial ankle arthrodesis was performed 6 ± 3.5 years before conversion to TAR. In all patients, the conversion to TAR was performed using a nonconstrained cementless three-component prosthesis. Intraoperative and postoperative complications, revision procedures, and prosthesis component loosening were evaluated. Weightbearing radiographs were used to determine the angular alignment of the tibial and talar components using α/β/γ angles and to analyze the bone-implant interface. Osseointegration was defined as visible trabecular structures at the bone-implant interface without radiolucent lines. The criteria for radiographic loosening was defined as subsidence or migration of prosthesis components and/or a cystic lesion with a diameter at least 2 mm. Clinical assessment included pain evaluation, measurement of ankle ROM, and quality of life.

RESULTS

Two of the 18 patients sustained an intraoperative medial malleolar fracture. In three patients, delayed wound healing was observed. At latest followup, four patients had incomplete osseointegration (posterior quarter of the bone-prosthesis interface on the tibial side). None of the 18 patients had prosthesis loosening. In all patients, both components were neutrally aligned. Two patients had painful arthrofibrosis with reduced ROM, which we treated with an open arthrolysis and exchange of mobile-bearing inlay; one other patient is considering a revision for substantial tibial component medial tilt with collapse of the medial arch. At the latest followup, the mean dorsiflexion and plantar flexion were 8.5° ± 3° and 15° ± 5°, respectively. The mean visual analog scale (VAS) score decreased from 9 ± 0.8 to 1.7 ± 1.6 (p < 0.001). The Short Form Health Survey questionnaire (SF-36) physical and mental outcome scores improved from 34 ± 5 to 74 ± 11 (p < 0.001) and from 49 ± 4 to 75.5 ± 7 (p < 0.001).

CONCLUSIONS

Conversion of an ankle arthrodesis to a TAR is a technically challenging procedure. In this small series, it was associated with frequent complications including arthrofibrosis, and functional outcomes including postoperative ROM were lower than reported for primary TAR. However, pain and function did improve. Further studies are necessary to address long-term clinical and radiographic outcomes in this patient cohort.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Total Ankle Arthroplasty for the Treatment of Symptomatic Nonunion Following Tibiotalar Fusion

Background Nonunion of an ankle arthrodesis is associated with significant pain and morbidity. Revision arthrodesis presents greater short-term morbidity and long-term sequelae. 1-6 Recent reports have demonstrated the feasibility of converting a symptomatic nonunion of an ankle arthrodesis to a total ankle arthroplasty.7-9 The objective of the present study was to evaluate the short-term outcome associated with take down of symptomatic nonunions of ankle arthrodeses and conversion to a fixed bearing, intramedullary total ankle arthroplasty. Methods Five patients with symptomatic, aseptic tibiotalar arthrodesis nonunions (average age, 62.2 years), who underwent conversion to a total ankle arthroplasty were retrospectively identified and assessed at a prospective office visit. Minimum follow-up was 12 months (average, 21.3 months). Clinical outcomes were assessed on the basis of the American Foot and Ankle Society (AOFAS) ankle-hindfoot score10 and the Foot Function Index.11,12 Radiographic analysis, patient satisfaction and pain levels were also evaluated. Results The average post-operative AOFAS ankle-hindfoot score was 82.6, while the FFI was 28.2%. The average clinical range of motion was 35 degrees. Visual analog scale (VAS) pain scores averaged 31.1 out of 100. Four out of the five patients were very satisfied or satisfied. Radiographically, the tibial and talar components were stable in all patients without evidence of loosening, migration, or subsidence. There were no complications requiring additional procedures. Conclusions Patients undergoing ankle arthrodesis that is complicated by an aseptic nonunion pose a difficult clinical problem. Conversion to a total ankle arthroplasty with a fixed bearing, intramedullary implant is a viable treatment option with reliable short-term results.

LEVELS OF EVIDENCE

Therapeutic, Level IV: Case series.

The influence of footwear on functional outcome after total ankle replacement, ankle arthrodesis, and tibiotalocalcaneal arthrodesis

BACKGROUND

Gait analysis after total ankle replacement and ankle arthrodesis is usually measured barefoot. However, this does not reflect reality. The purpose of this study was to compare patients barefoot and with footwear.

METHODS

We compared 126 patients (total ankle replacement 28, ankle arthrodesis 57, and tibiotalocalcaneal arthrodesis 41) with 35 healthy controls in three conditions (barefoot, standardized running, and rocker bottom shoes). Minimum follow-up was 2 years. We used dynamic pedobarography and a light gate.

MAIN OUTCOME MEASURES

relative midfoot index, forefoot maximal force, walking speed.

FINDINGS

The relative midfoot index decreased in all groups from barefoot to running shoes and again to rocker bottom shoes (p<0.001). The forefoot maximal force increased wearing shoes (p<0.001), but there was no difference between running and rocker bottom shoes. Walking speed increased by 0.06 m/s with footwear (p<0.001). Total ankle replacement and ankle arthrodesis were equal in running shoes but both deviated from healthy controls (total ankle replacement/ankle arthrodesis smaller RMI p=0.07/0.017; increased forefoot maximal force p=0.757/0.862; slower walking speed p<0.001). In rocker bottom shoes, this ranking remained the same except the relative midfoot index merged to similar values. Tibiotalocalcaneal arthrodesis were inferior in both shoes.

INTERPRETATION

Runners are beneficial and the benefit is greater for fusions and replacements. Rocker bottom shoes have little added benefit. Total ankle replacement and ankle arthrodesis were equal but inferior to healthy controls. Tibiotalocalcaneal arthrodesis has an inferior outcome.

Trends in treatment of advanced ankle arthropathy by total ankle replacement or ankle fusion

BACKGROUND

Total ankle replacement (TAR) and ankle fusion (AF) are the 2 major operative options for treatment of advanced ankle arthropathy; there is, however, no large epidemiologic study comparing nationwide trends of these 2 procedures. The current study used a nationwide database to compare epidemiologic profiles of TAR and AF.

METHODS

Data collected for the Nationwide Inpatient Sample (NIS) from 2000 to 2010 were reviewed. Procedures were identified by searching for ICD-9-CM codes 81.11 (AF) and 81.56 (TAR). Patients' demographics and comorbidities, geographic distribution, and cost of procedures were compared.

RESULTS

The NIS analysis identified 2666 TAR and 16 419 AF cases which was extrapolated to 13 145 TAR and 80 426 AF nationwide. Spearman's ρ showed an increase in the number of AF per year while the number of TAR cases remained relatively flat per year until 2006, after which there was a steady increase in the number of TAR performed. Patients receiving a TAR tended to be older, female, and white. Patients who underwent AF were more likely to be obese or diabetic than TAR patients. Both TAR and AF were performed more frequently in private urban hospitals through 2007. However, in 2010, the number of TAR procedures was greater in academic centers compared to private urban hospitals.

CONCLUSIONS

Despite recent increases in the number of TAR implanted, AF was still performed more than 6 times more frequently for advanced ankle arthropathy. A trend was demonstrated toward an increasing number of TAR being implanted in academic centers, and in patients with more underlying comorbidities than was previously seen.

LEVEL OF EVIDENCE

Level II, prognostic study.

Gait analysis in orthopedic foot and ankle surgery--topical review, part 1: principles and uses of gait analysis

Gait analysis, the systematic study of human walking, is a field that has been studied for well over 100 years. With the technological and scientific advancements of the last several decades, there has been substantial improvement in our understanding of the mechanics of human walking. Particularly important has been the advancement in understanding of the differences between normal and pathological gait. The purpose of this paper is to review the principles of gait analysis, with a particular focus on the underlying methods and science. This will assist orthopedic foot and ankle surgeons in better understanding the methods and meaning of gait research and the publications that commonly appear in the orthopedic foot and ankle surgery literature.

LEVEL OF EVIDENCE

Level V, expert opinion.

The midfoot load shows impaired function after ankle arthrodesis

BACKGROUND

A large number of parameters are registered by pedobarography, usually requiring a research setting for interpretation. The purpose of this study was to evaluate which pedobarographic parameters (adjusted for walking speed and body weight) discriminate between healthy volunteers and patients after ankle or tibiotalocalcaneal arthrodesis. Furthermore, we evaluated which parameters are associated with the American Orthopaedic Foot and Ankle Society (AOFAS) score.

METHODS

Thirty-five healthy volunteers, 57 patients with ankle and 42 with tibiotalocalcaneal arthrodesis were assessed by AOFAS scores and dynamic pedobarography. The arthrodesis patients were further investigated with radiographs. Median follow up was 4 years. Eighteen basic parameters were measured each in the hind-, mid-, and forefoot. For dimension reduction, we represented a pre-selected set of 9 parameters by two indices (load, rollover). We used ordinal logistic and multiple linear regression to address the questions.

FINDINGS

The midfoot index of load was the most important pedobarographic predictor (interquartile range odds ratio 100; 95% confidence interval 13, 771) for belonging to the healthy volunteers rather than the ankle or tibiotalocalcaneal arthrodesis groups. Similarly, it was an independent predictor for the AOFAS score (interquartile range effect 5 points; 95% confidence interval 1, 9). Healthy volunteers had a deeper midfoot depression in the force/pressure time graphs compared to patients after arthrodesis.

INTERPRETATION

When evaluating foot function after ankle or tibiotalocalcaneal arthrodesis, the interpretation of a large number of pedobarographic parameters can be reduced to the interpretation of the midfoot index of load and the evaluation of the force/pressure time graphs.