Revision ankle fusion using internal compression arthrodesis with screw fixation

Non-Union Treatment in the Foot, Ankle, and Lower Leg: A Multicenter Retrospective Study Comparing Conventional Treatment with the Human Allogeneic Cortical Bone Screw (Shark Screw®)

Addressing non-unions involves stabilizing the affected area through osteosynthesis and improving bone biology using bone grafts. However, there is no consensus on the optimal treatment method. This study aims to compare outcomes of non-union surgery using conventional treatment methods (metal hardware ± graft) versus osteosynthesis with the human allogeneic cortical bone screw (Shark Screw®) alone or in combination with a metallic plate. Thirty-four patients underwent conventional treatment, while twenty-eight cases received one or more Shark Screws®. Patient demographics, bone healing, time to bone healing, and complications were assessed. Results revealed a healing rate of 96.4% for the Shark Screw® group, compared to 82.3% for the conventionally treated group. The Shark Screw® group exhibited a tendency for faster bone healing (9.4 ± 3.2 vs. 12.9 ± 8.5 weeks, p = 0.05061). Hardware irritations led to six metal removals in the conventional group versus two in the Shark Screw® group. The Shark Screw® emerges as a promising option for personalized non-union treatment in the foot, ankle, and select lower leg cases, facilitating effective osteosynthesis and grafting within a single construct and promoting high union rates, low complications, and a rapid healing process.

Republication of "Total Ankle Replacement Conversion to Tibiotalocalcaneal Arthrodesis With Bulk Femoral Head Allograft and Pseudoelastic Intramedullary Nail Providing Sustained Joint Compression"

Tibiotalocalcaneal (TTC) arthrodesis is commonly performed to salvage a failed total ankle replacement. These salvage procedures are complicated by significant bone loss from the ankle replacement and are associated with low patient satisfaction. Here, we describe 2 cases of patients who presented with a failed total ankle replacement and underwent arthrodesis using a bulk femoral head allograft and a novel pseudoelastic intramedullary nail. The intramedullary nail contains an internal pseudoelastic element that adapts to bone resorption and settling allowing for compression to be maintained at the arthrodesis sites throughout healing. In the first case, a 65-year-old woman with a failed total ankle replacement underwent TTC arthrodesis. The second case involved an obese 53-year-old woman who had previously undergone 2 total ankle replacement procedures that resulted in unsuccessful outcomes. In both cases, union was demonstrated on computed tomographic scan by 6 months. At 2 years postsurgery, both patients were satisfied with the procedure. These cases provide preliminary evidence that tibiotalocalcaneal arthrodesis with a pseudoelastic IM nail and structural allograft is an appropriate treatment for failed total ankle replacements. Level of Evidence: Level IV, therapeutic, case series.

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.

Outcomes of Salvage Arthrodesis and Arthroplasty for Failed Osteochondral Allograft Transplantation of the Ankle

BACKGROUND

Osteochondral allograft (OCA) transplantation is a useful treatment for posttraumatic ankle arthritis in young patients, but failure rates are high and reoperations are not uncommon. The aim of this study was to evaluate the outcomes of failed ankle OCA transplantation converted to ankle arthrodesis (AA) or total ankle arthroplasty (TAA).

METHODS

We evaluated 24 patients who underwent salvage procedures (13 AA and 11 TAA) after primary failed ankle OCA transplantation. Reoperations were assessed. Failure of the salvage procedure was defined as an additional surgery that required a revision AA/TAA or amputation. Evaluation among nonfailing ankles included the American Academy of Orthopaedic Surgeons Foot and Ankle Module (AAOS-FAM), pain, and satisfaction.

RESULTS

In the salvage AA cohort, 3 patients were classified as failures (2 revision AA and 1 amputation). The 10 nonfailing patients had a mean follow-up of 7.4 years. Eighty-eight percent were satisfied with the procedure, but 63% reported continued problems with their ankle (eg, pain, swelling, stiffness). Mean pain level was 1.9 and AAOS-FAM core score was 83±13. In the salvage TAA cohort, 2 patients were classified as failures (both revision TAA). The 9 nonfailing patients had a mean follow-up of 3.8 years. Fifty percent were satisfied with the procedure, but 40% reported continued problems with their ankle. The mean pain level was 1.3, and the median AAOS-FAM core score was 82±26.

CONCLUSION

Revision and reoperation rates for salvage procedures following failed OCA transplantation of the ankle are higher compared to published data for primary AA and TAA procedures. However, we believe OCA transplantation can serve as an interim procedure for younger patients with advanced ankle joint disease who may not be ideal candidates for primary AA or TAA at the time of initial presentation.

LEVEL OF EVIDENCE

Level IV, case series.

Total Ankle Replacement Conversion to Tibiotalocalcaneal Arthrodesis With Bulk Femoral Head Allograft and Pseudoelastic Intramedullary Nail Providing Sustained Joint Compression

Tibiotalocalcaneal (TTC) arthrodesis is commonly performed to salvage a failed total ankle replacement. These salvage procedures are complicated by significant bone loss from the ankle replacement and are associated with low patient satisfaction. Here, we describe 2 cases of patients who presented with a failed total ankle replacement and underwent arthrodesis using a bulk femoral head allograft and a novel pseudoelastic intramedullary nail. The intramedullary nail contains an internal pseudoelastic element that adapts to bone resorption and settling allowing for compression to be maintained at the arthrodesis sites throughout healing. In the first case, a 65-year-old woman with a failed total ankle replacement underwent TTC arthrodesis. The second case involved an obese 53-year-old woman who had previously undergone 2 total ankle replacement procedures that resulted in unsuccessful outcomes. In both cases, union was demonstrated on computed tomographic scan by 6 months. At 2 years postsurgery, both patients were satisfied with the procedure. These cases provide preliminary evidence that tibiotalocalcaneal arthrodesis with a pseudoelastic IM nail and structural allograft is an appropriate treatment for failed total ankle replacements.

Level of Evidence:

Level IV, therapeutic, case series.

Long-term Follow-up of Revision Osteochondral Allograft Transplantation of the Ankle

BACKGROUND

Osteochondral allograft (OCA) transplantation is a useful alternative for treatment of posttraumatic ankle arthritis in young patients but has a relatively high failure rate and further procedures are often required. The purpose of this study was to evaluate outcomes of patients who underwent revision OCA transplantation of the ankle after failed primary OCA transplantation.

METHODS

Twenty patients underwent revision OCA transplantation of the ankle between 1988 and 2015. Mean age was 44 years, 55% (11 of 20) were female. The mean time from primary to revision OCA was 3.0 ± 1.7 years. All patients had a minimum follow-up of 2 years. Outcomes included the American Academy of Orthopaedic Surgeons Foot and Ankle Module (AAOS-FAM) and questionnaires evaluating pain and satisfaction. Failure of the revision OCA was defined as a conversion to arthroplasty, arthrodesis, or amputation.

RESULTS

Ten of 20 ankles required further surgery, of which 30% (6 of 20) were considered OCA revision failures (4 arthrodeses, 1 arthroplasty, and 1 amputation). The mean time to failure was 6.7 (range, 0.6-13.1) years. Survivorship of the revision OCA was 84% at 5 years and 65% at 10 years. The 14 patients with grafts remaining in situ had an average follow-up of 10.3 years; mean AAOS-FAM Core Score was 70.5 (range, 42.3-99). Of the patients who answered the follow-up questions, 4 of 7 reported moderate to severe pain, and 5 of 12 were satisfied with the results of the procedure.

CONCLUSION

Although the results of revision ankle OCA transplantation are not inferior to primary OCA transplantation, the high rates of persistent pain, further surgery, and graft failure suggest that the indications for OCA as a revision procedure should be carefully evaluated, with proper patient selection. Considering the treatment alternatives, revising a failed OCA transplantation can be a useful treatment option, especially for young and active patients who wish to avoid arthrodesis or arthroplasty.

LEVEL OF EVIDENCE

Level IV, case series.

Hindfoot Arthrodesis with the Blade Plate: Increased Risk of Complications and Nonunion in a Complex Patient Population

BACKGROUND

Previous hindfoot surgeries present a unique challenge to hindfoot arthrodesis, as the patients may have multiple incisions around the hindfoot. In high-risk patients with compromised soft tissues, a posterior approach can provide an alternative for a fresh soft tissue plane for the surgery. The use of a blade plate construct is widely accepted; however, there are limited data supporting the use of a posterior approach.

QUESTIONS/PURPOSES

We asked (1) what proportion of patients treated with this technique achieved osseous union; (2) what complications were observed; (3) were any patient-demographic or health-related factors associated with the likelihood that a patient would have a complication develop?

METHODS

Between December 2001 and July 2014, 42 patients received a posterior blade plate. During the period in question, indications for hindfoot arthrodesis using posterior blade fixation were subtalar osteoarthritis below an ankle fusion, malunion or nonunion, failed tibiotalocalcaneal arthrodesis attributable to nonunion of the tibiotalar and/or subtalar joint; or tibiotalar and subtalar osteoarthritis in patients with impaired bone or soft tissue quality (particularly if the soft tissue problem was anterior). During that period, all patients who met those indications were treated with a posterior blade plate. Forty (95%) were included in this study, and two were lost to followup before the 1-year minimum required by the study. Demographics (age, gender, BMI, smoking status, and comorbidities) and surgical data (indication, previous treatment, and additional procedures) were analyzed. Of the 40 patients included, 27 (68%) were male and 13 (33%) were female, with a median of two previous hindfoot or ankle surgeries (range, 0-9 surgeries). The mean age of the patients was 56 ± 13 years. Followup averaged 47 ± 28 months (range, 14-137 months). Twenty-eight of 40 (70%) patients had a tibiotalocalcaneal arthrodesis as a primary (n = 6), primary staged (n = 10), revision (n = 9), or revision staged (n = 3) procedure. Eleven of 40 patients (28%) underwent ankle arthrodesis (primary n = 7, revision n = 4). One of the 40 patients (3%) underwent tibiotalocalcaneal arthrodesis for a failed total ankle arthroplasty. Weightbearing radiographs were used to assess fusion. Osseous fusion was defined as visible trabecular bridging on the lateral and AP ankle views within 6 postoperative months. Delayed union was defined as osseous fusion occurring between 6 and 12 months. Nonunion was defined as no visible trabecular bridging at the latest followup (longer than 12 months). Clinic and surgery notes were reviewed for complications. Univariate analysis was performed to compare patient groups: patients with solid union versus nonunion, and patients with versus without complications.

RESULTS

Twenty-nine of 40 (73%) patients had osseous fusion within 6 postoperative months. Four of 40 (10%) patients had a delayed union between 6 and 12 months, and seven of the 40 (18%) patients had nonunions, which occurred in the ankle (n = 3), subtalar (n = 3), or both (n = 1) joints. There were 26 complications observed: 18 (69%) were considered major and eight (31%) were minor. With the numbers available, we did not identify any demographic or surgical factors associated with complications, delayed union, or nonunion.

CONCLUSIONS

The proportion of patients treated with a posterior blade plate hindfoot fusion who had delayed union or nonunion is greater than that reported for patients in other series who underwent primary hindfoot arthrodesis with other approaches, and the proportion of patients who had complications develop is high. Further studies are needed to address alternative approaches to achieve hindfoot fusion in patients with complex hindfoot problems.

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.

Clinical and Operative Factors Related to Successful Revision Arthrodesis in the Foot and Ankle

BACKGROUND

Arthrodesis is a common operative procedure used to manage arthritis and deformity in the foot and ankle. Nonunion is a possible and undesirable outcome in any arthrodesis surgery. Rates of nonunion in the foot and ankle literature range from 0% to 47% depending on the patient population and joint involved. Multiple factors can contribute to developing a nonunion including location, fixation method, tobacco use, diabetes, infection, and others.

METHODS

The case logs of 3 foot and ankle surgeons were reviewed from January 2007 to September 2014 to identify nonunion arthrodesis revision cases. The patient factors reviewed included diabetes, inflammatory arthropathy, tobacco use, history of infection, nonunion elsewhere, neuropathy, Charcot arthropathy, posttraumatic arthritis, and prior attempt at revision arthrodesis at the same site. Operative records were reviewed to identify location of the nonunion, instrumention, use of allograft or autograft bone, use of iliac crest bone marrow aspirate (ICBMA) and use of orthobiologics such as bone morphogenetic protein (BMP) during the revision arthrodesis. Successful revision was defined as radiographic union on the final radiograph during follow-up. Eighty-two cases of revision arthrodesis were identified with an average follow-up of 16 months.

RESULTS

The overall nonunion rate was 23%. Neuropathy and prior attempts at revision were identified as significant risks (P <.05) for persistent nonunion. Odds ratio calculated based on previous attempts at revision arthrodesis found a 2.8-fold increase in the risk of failure for each attempt at revision.

CONCLUSION

Revision arthrodesis for nonunion in the foot and ankle was successful (77%) under a variety of patient and operative conditions. Neuropathy was a significant patient risk factor for persistent nonunions, and we believe it is important to identify even in the nondiabetic patient. As the number of attempts at revisions increases, there is a subsequent 3-fold increase in the risk of persistent nonunion.

LEVEL OF EVIDENCE

Level IV, case series.

The use of the 4.5 mm 90° titanium cannulated LC-angled blade plate in tibiotalocalcaneal and complex ankle arthrodesis

BACKGROUND

Tibiotalocalcaneal arthrodesis is used to manage end stage arthritis, often associated with severe bone loss. The goal is to relieve pain through a stable, well-aligned hindfoot and ankle. We describe our initial results and outcome of ankle and tibiotalocalcaneal arthrodesis using a 90° blade plate.

METHODS

We retrospectively reviewed the records of patients managed at our institution between 2010 and 2014. Twenty cases were identified who had either talocrural (n = 9) or TTC fusion (n = 11) with 1 patient having both ankle and then TTC fusion in separate sittings.

RESULTS

Fusion occurred in 18 of the 20 cases (90%) with correction of angular deformity and restoration of hindfoot alignment. None of the 18 patients developed complications and all discharged to follow-up when independently mobile and satisfied with the outcome.

CONCLUSIONS

This study demonstrated that using a 90° blade plate for ankle or TTC arthrodesis in a diverse group of complex primary and revision indications associated with severe deformity and bone loss resulted in a high rate of bony union and stable deformity correction.

Does autogenous bone graft work? A logistic regression analysis of data from 159 papers in the foot and ankle literature

BACKGROUND

While autogenous cancellous iliac crest bone graft is the gold standard for foot and ankle surgery, it lacks Level I evidence. Although one third of all graft cases performed in the United States today rely on allograft, some surgeons believe no graft is necessary. We hypothesized that a systematic review of the foot and ankle literature would reveal that (1) autogenous bone graft during foot and ankle arthrodesis would demonstrate healing rates that were superior to the use of either using allograft or no bone graft at all, and (2) these differences would be even more dramatic in patients having risk factors that impair bone healing. To our knowledge, neither of these assessments to date has ever been performed with this body of literature. The goal of this study was to review the use and union rates of bone graft during foot and ankle arthrodesis and determine if autogenous bone graft was superior.

METHODS

A literature search was performed to include articles between 1959 and 2012 using autograft, allograft, and/or no bone graft for foot and/or ankle arthrodesis. Case reports involving fewer than four patients, investigations failing to incorporate outcome data, those involving orthobiologic augmentation, and those including vascularized graft, xenograft, or pediatric patients were excluded. Recorded search results included patient demographics, comorbidities, pre-operative diagnosis, surgical procedure, bone graft type and indication, union rate, method of fixation, patient satisfaction, all outcome scores, definition of healing/success, and any listed complications including revision. Final data were stratified based upon the type of graft material.

RESULTS

This search generated 953 related articles, of which 159 studies (5327 patients) met inclusion criteria. The majority (153/159) were retrospective case series. Systematic review demonstrated a trend toward higher union rates for cancellous autograft (OR 1.39, p=0.11), structural autograft (OR 1.52, p=0.09), and cancellous allograft (OR 1.31, p=0.52) relative to no graft material, but none reached statistical significance. Compared to no graft, structural allograft trended toward worse performance (OR 0.62, p=0.17). The overall probability of union was 93.7% for cancellous autograft, 94.2% for structural autograft, 93.3% for cancellous allograft, 91.4% for no graft, and 86.9% for structural allograft. When only comparing the 19 papers that included a no graft arm (91.9% union rate), data revealed the highest union using cancellous autograft (95.1%, OR 1.73, p=0.09) and structural autograft (96.3%, OR 2.33, p=0.06) while only 76% for structural allograft. No significant statistical association existed between union rates and other recorded variables.

CONCLUSION

Systematic analysis of bone graft use in foot and ankle fusions favors the use of autograft and cancellous allograft for optimized healing rates, although no differences were statistically significant. If we assume that graft material been chosen for more complex procedures having lower anticipated union rates, then these data lend further support to the use of autograft and cancellous allograft.

LEVEL OF EVIDENCE

Level IV.

Applications of the medial femoral condyle free flap for foot and ankle reconstruction

BACKGROUND

Avascular necrosis (AVN) or persistent nonunion occurs in situations of poor vascular supply. Some specific situations that plague the foot and ankle surgeon are talus nonunion, talus AVN, navicular AVN, and failed ankle arthrodesis with bone loss. The medial femoral condyle (MFC) flap has emerged as a popular source of vascularized corticocancelous bone. We present a series of cases demonstrating the versatility of the MFC flap in complex foot and ankle pathology.

METHODS

A retrospective review was completed of all MFC flaps used in the foot and ankle over the past 5 years. Five patients were identified (average age 48). Surgical indications included talar AVN and ankle arthritis, talar nonunion, and navicular AVN. All patients had undergone conventional bone grafting techniques, which failed, prior to being treated with a MFC free flap; this series of patients did not possess significant medical comorbidities. Fixation techniques included compression screw fixation, plate osteosynthesis, or fine wire external fixation. The average follow-up was 20 months (range 8 to 40 months).

RESULTS

There was a 100% flap success rate with no returns to the operating room for thrombosis. The volume of the bone flaps was 5.6 cm(3) (range 1 cm(3) to 12 cm(3)). The average follow-up time was 20 months (range 8 to 40 months). All cases resulted in union, and full weight bearing status was achieved at a mean of 23.8 weeks (range 10 to 52 weeks) postoperatively.

CONCLUSIONS

Vascularized bone transfer in the form of the MFC free flap was a valuable method for foot and ankle reconstruction. The MFC flap provided an alternative for those defects that were smaller then 3 cm in length. In our experience, for small bone defects requiring vascularized bone, the MFC flap is currently the ideal donor location supplanting the iliac crest.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

The slot graft technique for foot and ankle arthrodesis in a high-risk patient group

BACKGROUND

High rates of arthrodesis nonunion have been described in the ankle, hindfoot and midfoot in patients with significant risk factors. The purpose of this study was to evaluate fusion rates, risk of reoperation, postoperative pain scores and patient satisfaction for a slot graft inlay arthrodesis technique used in a high-risk group of foot and ankle patients.

MATERIALS AND METHODS

We retrospectively reviewed all ankle, hindfoot and midfoot arthrodeses by two foot and ankle surgeons in our institution between January 2000 and January 2009. Seventeen arthrodesis procedures in 16 patients using the slot graft technique were identified. Patient charts were reviewed for medical history, risk factors, previous surgery and postoperative complications. Time to union was evaluated on radiographs. Patients provided final followup by phone with an assessment of pain, overall satisfaction and use of orthotic or assistive devices.

RESULTS

Union occurred in 13 arthrodesis procedures (77%) with an average time to union of 5 months. Postoperative infection occurred in one patient. Additional surgery was performed in nine patients. At final followup patients reported low pain scores (3 of 10) and high satisfaction (8 of 10). Fourteen of 15 patients contacted indicated that they would choose to undergo the procedure again.

CONCLUSION

The slot graft arthrodesis technique provided satisfactory results in this small group of patients with a low complication rate. Patient satisfaction rates were high with low pain scores at an average of 62 months postoperatively.

Compression forces of internal and external ankle fixation devices with simulated bone resorption

BACKGROUND

Internal and external fixation techniques have been developed to provide rigidity and stability to a fusion site such as in tibiotalocalcaneal (TTC) arthrodesis. Compression of the fusion site plays an integral role in primary bone healing, though little work has been done to quantify the compressive force values of ankle fixation devices.

MATERIALS AND METHODS

Using synthetic and cadaveric bone models, a Newdeal/Integra PantaNail and DePuy VersaNail were tested as compressive intramedullary (IM) nails while an Encore True/Lok and an Ace-Fischer frame were tested as external fixators.

RESULTS

The PantaNail experienced maximum compressive loads of 1898 and 1255 N in synthetic and cadaveric constructs, respectively. The VersaNail experienced max compressive loads 388 N during installation. All IM nails tested experienced decreased compressive loads after removal of the external guide and instrumentation. The external fixators were loaded to approximately 1200 N in both synthetic and cadaveric constructs. The decrease in compressive load was recorded as a function of simulated fusion site bone resorption for all devices. The IM nails experienced a 90% reduction in load with less than 1 mm of resorption, while the external fixators held 50% load for over 4 mm of resorption. These data were verified using a simple constitutive model of IM nails and external fixators.

CONCLUSION

Intramedullary nails are capable of generating compression, however, are unable to provide sustained compression for any considerable amount of resorption. External fixators are inherently capable of applying and sustaining greater amounts of compression.

CLINICAL RELEVANCE

Surgeons who perform TTC arthrodesis procedures should be aware of a device's ability to generate and sustain compression with respect to bone resorption.

Ankle arthrodesis

Numerous techniques for ankle arthrodesis have been reported since the original description of compression arthrodesis. From the early 1950s to the mid 1970s, external fixation was the dominant technique utilized. In the late 1970s and 1980s, internal fixation techniques for ankle arthrodesis were developed. In the 1990s, arthroscopic ankle arthrodesis was developed for ankle arthrosis with minimal or no deformity. The open technique is still widely used for ankle arthrosis with major deformity. For complex cases that involve nonunion, extensive bone loss, Charcot arthropathy, or infection, multiplanar external fixation with an Ilizarov device, with or without a bone graft, may achieve successful union. The fusion rate in most of the recently published studies is 85% or greater, and may depend on the presence of infection, deformity, avascular necrosis, and nonunion.

Revisional hindfoot arthrodesis

Salvage of a failed hindfoot arthrodesis is an extensive undertaking for the surgeon and patient. With increased morbidity and postoperative convalescence and complications, patients must understand the risk involved in this type of revisional surgery. This article provides a systematic approach to revisional hindfoot arthrodeses, focusing on patient evaluation, surgical technique, and postoperative treatment.

An approach to the failed ankle arthrodesis

Ankle arthrodesis remains the gold standard of surgical treatment for advanced ankle joint arthritis. Failure can occur as a result of infection, nonunion or malunion, resulting in pain and poor function. This paper offers a systematic approach to preventing, and managing these problems should they occur. Revision arthrodesis performed with a detailed understanding of the appropriate alignment and mechanics of the ankle joint, combined with meticulous attention to understanding and reversing the cause of the failure can result in successful salvage and restoration of function.

Revision tibiotalar arthrodesis

BACKGROUND

Contemporary recommendations for primary and revision ankle arthrodesis favor internal compression techniques involving the use of screw and/or plate fixation. While tibiotalocalcaneal arthrodesis with internal fixation may be a suitable method of salvage for the treatment of a failed tibiotalar arthrodesis in selected patients, ring external fixation has been reported as an alternative. We reviewed our experience with revision tibiotalar arthrodesis, with a focus on ring external fixation.

METHODS

Forty-five consecutive patients underwent revision tibiotalar arthrodesis with use of repeat internal fixation (eleven patients), ring external fixation (twenty-two patients), or tibiotalocalcaneal arthrodesis (twelve patients). Union rates were assessed radiographically, and functional outcome was determined with use of preoperative and postoperative American Orthopaedic Foot and Ankle Society ankle-hindfoot scores.

RESULTS

All forty-five patients were available for follow-up at an average of 50.3 months. The average ankle-hindfoot score improved from 31.1 points preoperatively to 65.8 points at the time of the most recent follow-up. At the time of the most recent follow-up, the union rate was 88.9% (forty of forty-five). Fusion was achieved with revision tibiotalar arthrodesis in thirty-six (80%) of forty-five patients, including eight of the eleven patients in the repeat internal fixation group, nineteen of the twenty-two patients in the ring external fixation group, and nine of the twelve patients in the tibiotalocalcaneal arthrodesis group. Re-revision led to union in four of five patients. The overall union rate for ring external fixation, including revision and re-revision tibiotalar arthrodeses, was 84.6% (twenty-two of twenty-six). The five patients with persistent nonunion following revision ankle arthrodesis opted for transtibial amputation.

CONCLUSIONS

Revision tibiotalar arthrodesis leads to satisfactory limb salvage in a majority of patients. Ring external fixation may facilitate clinically acceptable limb salvage in complex cases when methods of internal fixation are limited or even contraindicated.

Outcome of Ilizarov ankle arthrodesis

BACKGROUND

Many operative techniques have been described for ankle arthrodesis, with varying fusion rates. In revisions, the fusion rate is lower than in primary arthrodesis. Recent reports have described good results after Ilizarov ankle arthrodesis. However, descriptions were qualitative, with none using an accepted score. We describe our experience with this technique and functional outcomes in our patients.

METHODS

Seventeen patients (average age 48 years) had primary or revision unilateral ankle arthrodesis using the Ilizarov technique at two centers. Diagnoses included post-traumatic arthritis and Charcot arthropathy. Three patients had talar osteonecrosis. Time in the frame averaged 15 weeks and in a cast 4 weeks. Followup averaged 6 years. Outcome was assessed using the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale.

RESULTS

All ankles achieved solid fusion. The average AOFAS score was 65 out of 86 possible. Based on this, results were defined as excellent in three patients, good in eight, fair in four, and poor in two. Minor complications were common, all resolving with local treatment. No deep infection developed. One fusion malunited in 8 degrees of varus.

CONCLUSIONS

The Ilizarov external fixator has numerous advantages applicable to ankle fusion, including: stable fixation, respect for soft tissues, and the possibility of postoperative alignment 'fine-tuning'. Additionally, the ability to direct forces through or around skeletal elements allows varying of the load through the skeletal elements, allowing early weightbearing. The Ilizarov technique, with its high union rate, may be considered for any ankle arthrodesis but is especially useful in complex cases such as revisions, talar osteonecrosis, soft-tissue compromise, and infection. Early weightbearing is an added benefit.

Transfibular ankle arthrodesis with rigid internal fixation: an assessment of outcome

BACKGROUND

Transfibular ankle arthrodesis with internal fixation and fibular onlay grafting has resulted in acceptable fusion rates. This study analyzed the results of ankle arthrodesis using one operative technique in a large series of patients with high and low risks for nonunions.

METHODS

Fifty consecutive patients had a transfibular ankle arthrodesis with rigid internal fixation and fibular onlay strut grafting from 1997 to 2004. Two patients were lost to followup. The remaining 48 patients had preoperative and postoperative clinical and radiographic examinations and then were stratified into high-risk and low-risk groups for ankle nonunions. Fifteen of 48 patients were considered at high risk for nonunion. Rate of osseous fusion, satisfaction with the procedure, correction of the deformity, and relief of pain were evaluated. Thirty-five of 48 patients were evaluated with the AOFAS ankle-hindfoot scale at an average 45 months after surgery.

RESULTS

Forty-six of 48 patients had bony union (96% union rate). Fourteen of 15 (93%) high-risk patients had bony fusion in an average of 83 days. Thirty-two of 33 patients (97%) in the low-risk group had bony fusion at an average of 81 days. The AOFAS ankle-hindfoot score improved from 38 to 74 in 12 of 15 patients in the high-risk group and from 34 to 69 in 24 of 33 patients in the low-risk group from preoperative to postoperative scores.

CONCLUSIONS

A transfibular ankle arthrodesis with rigid internal fixation and fibular onlay strut grafting can achieve a high rate of union in both a low-risk and high-risk patient populations. This technique can be an effective approach for most primary and revision cases with or without significant deformity. In addition the AOFAS ankle-hindfoot score improved significantly both in the high-risk and low-risk groups.

The role of cyclooxygenase-2 inhibition in foot and ankle arthrodesis

Cyclooxygenase-2 (COX-2) inhibitors are an important adjunct in controlling postoperative pain. Concerns exist regarding the use of NSAIDs for postoperative pain management because of the possible deleterious impact on bone healing in patients undergoing hindfoot arthrodesis. Orthopedic surgeons are concerned with: (1) a multimodal approach for postoperative pain control, and (2) bone healing following arthrodesis, fracture repair with rigid internal fixation, and cementless implants. The use of COX-2 inhibitors has been shown to be an important component of a pain control strategy but questions about their effects on bone healing have inhibited their use. This article discusses the laboratory and clinical data available on the use of COX-2 inhibitors on bone healing and their effects on foot and ankle arthrodesis procedures.

Treatment of malunion and nonunion at the site of an ankle fusion with the Ilizarov apparatus

BACKGROUND

Malunion and nonunion of an ankle fusion site are associated with pain, osteomyelitis, limb-length discrepancy, and deformity. The Ilizarov reconstruction has been used to treat these challenging problems.

METHODS

We reviewed the results in twenty-one ankles that had undergone a revision of a failed fusion, with simultaneous treatment of coexisting pathologic conditions, with use of the Ilizarov technique. Eight patients had undergone ankle fusion only, eleven had undergone ankle and subtalar fusion, and two had undergone pantalar fusion. Eighteen patients with an average limb-length discrepancy of 4 cm underwent limb lengthening simultaneously with the revision surgery. The average patient age was forty years. Indications for treatment were malunion (eleven patients), aseptic nonunion (eight patients), and infected nonunion (two patients). Clinical, subjective, objective, gait, and radiographic analyses were performed after an average duration of follow-up of 83.4 months.

RESULTS

Solid union was achieved in all ankles. The functional result was excellent for fifteen patients, good for three, fair for two, and poor for one. The bone result was excellent for ten ankles, good for nine, fair for one, and poor for one. All eighteen patients who underwent gait analysis had a heel-to-toe progression gait, and twelve achieved normal walking velocity with their shoes on. A plantigrade foot was achieved in each case, and only two patients had >5 degrees of residual deformity. During the Ilizarov treatment, forty-one minor complications (treated conservatively) and twenty major complications (treated surgically) occurred. After removal of the circular frame, seven other complications, which required four additional operations, occurred.

CONCLUSIONS

In patients with a failed ankle fusion, infection, limb-length discrepancy, and foot deformity can be addressed simultaneously with use of the Ilizarov apparatus to achieve a solid union and a plantigrade foot, usually with a clinically satisfactory result.

The use of circular wire external fixation in the treatment of salvage ankle arthrodesis

The authors retrospectively reviewed their experience with circular wire external fixation in the treatment of salvage ankle arthrodesis during the past 9 years. The results of 43 cases in a difficult patient population are presented with an average follow-up of 27.0 months. Thirty-three patients (80.5%) went on to achieve a solid fusion or stable pseudarthrosis. A minimum of a 4-ring frame construct was applied for an average of 96.1 days. The major complication rate was 51.2%, including 3 below-knee amputations (7.3%), 7 unstable nonunions (17.1%), 7 cases of osteomyelitis and/or deep-space infection (16.3%), 3 malunions (7.3%), and 2 tibial stress fractures (4.7%). The incidence of complications occurred similarly in patients with Charcot arthropathy, failed total ankle arthroplasty, septic fusion, posttraumatic deformity, or avascular necrosis of the talus, whereas it was relatively higher in patients who were diabetics, smokers, or had an increased body mass index. In addition, the incidence of a nonunion tended to increase with longer follow-up, suggesting that early presumption of a solid union may be erroneous. Based on our defined criteria of a stable, well-aligned fusion without severe pain or activity restrictions, 28 patients (68.3%) had a good result. Circular wire external fixation can be a viable treatment for complex ankle salvage pathology; however, it is difficult to predict the prospects of success or failure.

Avascular necrosis of the talus: current treatment options

AVN of the talus is a challenging disease process with respect to patho-physiology and treatment. We believe that our algorithm is a legitimate approach to aid the orthopedic surgeon in initiating a promising treatment. It is divided into different levels and allows to change between some. This is not the only way to proceed but it seems promising, especially if the long-term results with the vascularized bone grafts show revascularization of the talus. As always in medicine, the treatment needs to be individualized. Arthrodesis always should be the last option and is a challenging procedure.

PEMF as treatment for delayed healing of foot and ankle arthrodesis

BACKGROUND

Arthrodesis is the most common surgical treatment for foot and ankle arthritis. In adults, these procedures are associated with a 5% to 10% rate of nonunion. Pulsed electromagnetic field (PEMF) stimulation was approved by the Federal Drug Administration (FDA) for treatment of delayed unions after long-bone fractures and joint arthrodesis. The purpose of this study was to examine the results of PEMF treatment for delayed healing after foot and ankle arthrodesis.

METHODS

Three hundred and thirty-four foot and ankle arthrodeses were done. Nineteen resulted in delayed unions that were treated with a protocol of immobilization, limited weightbearing, and PEMF stimulation for a median of 7 (range 5 to 27) months. All patients were followed clinically and radiographically.

RESULTS

The use of PEMF, immobilization, and limited weightbearing to treat delayed union after foot and ankle arthrodesis was successful in 5 of 19 (26%) patients. Of the other 14 patients with nonunions, nine had revision surgery with autogenous grafting, continued immobilization, and PEMF stimulation. Seven of these eventually healed at a median of 5.5 (range 2 to 26) months and two did not heal. One patient had a below-knee amputation, and four refused further treatment.

CONCLUSIONS

The protocol of PEMF, immobilization, and limited weightbearing had a relatively low success rate in this group of patients. We no longer use this protocol alone to treat delayed union after foot and ankle arthrodesis.

Fusion of the Septic Ankle: Experience with 15 Cases Using Hybrid External Fixation

BACKGROUND

In cases of septic joint destruction, an unfavorable situation of soft tissues and chronic osteomyelitis are responsible for high failure rates of ankle fusions. We wanted to evaluate the control of infection and the fusion rate using hybrid external fixators for the fusion of the septic ankle in a prospective study.

METHODS

From 1996 to 1998, 15 arthrodeses were performed using hybrid external fixators. All patients had a combination of bone and soft tissue infections. Fourteen patients suffered from sequelae of posttraumatic osteoarthritis, and one patient suffered from rheumatoid arthritis. In 14 patients, pathogens could be identified; in 87%, Staphylococcus aureus was found. Eight patients had relevant concomitant diseases.

RESULTS

The preservation of limbs by solid tibiotalar fusion was achieved in 14 patients (93%). One patient maintained an infected pseudarthrosis. During the 12-month follow-up, three patients had a fistula that persisted, with two patients having a solid arthrodesis. Full weight-bearing was possible for all the patients with a successful fusion. Seventy-five percent of the patients that had not retired at the time of the study regained their fitness for work.

CONCLUSION

The hybrid external fixator presents a successful alternative for those arthrodeses of ankle joints where complications such as bone/joint infections or poor soft tissue conditions occur.

Revision of ankle arthrodesis

From 1989 to 1996, we treated 18 cases (10 males, eight females; average age 48.2 years) of failed ankle arthrodesis by revision of ankle arthrodesis and followed their progress for at least two years. The average time interval between original surgery and revision was 17.3 months. Revisions were needed due to infection in one case, nonunion in 10 cases, and malalignment in seven cases. The salvage operations included debridement in the infected case, refreshed pseudoarthrosis in nonunion cases, and corrective osteotomy in malalignment cases. Sixteen cases were fixed by crossed screws with internal compression, one infected case was fixed by an external fixator, and one case with bone loss was fixed with buttress plate. The average follow-up period was 40.4 months. There was one nonunion and two delayed unions, with an ultimate fusion rate of 94%. The average AOFAS ankle-hindfoot score was 70.9 at final follow up. There was one excellent result (5.6%), five good results (27.8%), 11 fair results (61%), and one poor result (5.6%), and the overall results were poorer compared with our series of primary arthrodesis. The time to fusion also took longer in the revision cases (average 2.7 months in primary cases and 4.8 months in revision cases). Fusion techniques that ensure solid union in a functional position are essential. If an ankle arthrodesis fails, however, revision is a salvage procedure that can achieve an acceptable result.

Revision ankle arthrodesis

Between 1996 and 1999, we performed successful revision ankle arthrodesis for aseptic nonunion in 10 patients using external fixation with bone graft and an implantable bone stimulator. The etiology of the ankle arthrosis in the patients was post-traumatic in eight and rheumatologic in two. The average age of the patients was 54. On average, each patient had received 2.5 previous surgeries (range, 1 to 5) prior to the original fusion attempt. Fusion occurred in all 10 of these patients at an average of 12.8 weeks following revision (range, nine to 20 weeks). Complications occurred in two patients: one had a pin tract infection which resolved with local pin care and oral antibiotics; the second patient had a varus malalignment which was accommodated with orthotics. This patient also had a deep peroneal nerve neuropraxia which resolved with observation. We evaluated all 10 patients with clinical and radiographic examination, and determined their functional results for a duration of follow-up of 15 months (range, six to 36 months). Using a modification of the AOFAS ankle/hindfoot scoring system, the results were: three excellent, four good, two fair, and one poor. All but one of these patients were satisfied with the outcome of this procedure. Radiographic analysis supported good clinical alignment and solid fusion.