Reproducibility of computed tomography to evaluate ankle and hindfoot fusions

Dedicated locking plate reduces non-union risk in open ankle fusion in obese patients

INTRODUCTION

Obesity is a growing public health concern. In ankle osteoarthritis, non-conservative treatment in advanced stages consists in ankle fusion, or else total ankle replacement, for which obesity is a relative contraindication. One of main complications of ankle fusion is non-union. Devascularization, obesity and fixation material are all factors involved in postoperative non-union, and have to be taken into account in surgical strategy for reliable results. The objective of this study was to compare the rate of ankle non-union in obese patients using quadruple screwing or a dedicated locking plate. The hypothesis was that the locking plate limits the risk of non-union in this population.

METHODS

All patients were obese (BMI>30kg/m2) and presented ankle osteoarthritis with>10° intra-articular deformity. The approach and joint preparation were performed via an anteromedial approach. Group S was composed of 32 patients, operated on by quadruple screwing; group P comprised 10 patients operated on using a dedicated locking plate. The main endpoint was a significant difference in the rate of non-union between the 2 groups. The secondary endpoint was improvement in pre- and 6-month postoperative AOFAS score.

RESULTS

Group S presented 31% non-union (10/32) and group P 0% (0/10) (p<0.05). Postoperative AOFAS score was significantly higher in group P: 67.8±10.4 [range, 40-92] vs. 83.1±8.0 [range, 64-92] (p<0.05).

CONCLUSION

The dedicated anterior locking plate is a technique of choice for ankle fusion in obese patients with intra-articular deformity>10°, to limit the risk of non-union.

LEVEL OF EVIDENCE

IV; retrospective study.

Determination of the Inter- and Intra-rater Reliability of Fusion Assessment in First Tarsometatarsal Joint Arthrodesis Using CT Scan: An Observational Study

Background

First tarsometatarsal joint arthrodesis is a common procedure performed by podiatrists and orthopedic surgeons. There remains debate on how useful CT scans are in assessing fusion status in the post-operative patient. The purpose of our study was to determine the reliability among both orthopedic surgeons and radiologists in reviewing both postoperative radiographs and CT in order to determine if fusion had occurred in patients undergoing 1st tarsometatarsal arthrodesis. A secondary purpose of this study was to determine if CT offered improved inter- and intra-rater reliability when compared to plain radiographs.

Methods

Patients who underwent 1st tarsometatarsal arthrodesis were retrospectively reviewed and those who underwent CT post-operatively for persistent pain were identified. Orthopedic surgeons and radiologists then analyzed the radiographs and CT of these patients for union with a threshold for union being set at 50% of the joint being fused. Imaging was then re-evaluated by the same provider 6 months later.

Results

24 patients were identified meeting inclusion criteria. Inter-rater reliability and intra-rater reliability for assessment of 1st tarsometatarsal arthrodesis were better with CT compared to radiographs; however, this association was not deemed reliable. Both imaging modalities were not able to assess union status confidently and reliably across reviewers, although CT scan had better intra-rater reliability.

Conclusions

While CT is frequently used to assess fusion in patients who have underwent 1st tarsometatarsal arthrodesis, it was not found to be better than radiographs. Practitioners should reconsider the use CT as the gold standard when assessing fusion in this population.

The value of bone SPECT/CT in evaluation of foot and ankle arthrodesis and adjacent joint secondary osteoarthritis

OBJECTIVE

To evaluate the value of SPECT/CT (single photon emission computed tomography/computed tomography) in foot and ankle arthrodesis and development of secondary osteoarthritis in the adjacent joints.

MATERIALS AND METHODS

SPECT/CT of 140 joints in the foot and ankle (34 upper ankle (UA), 28 lower ankle (LA), 27 talonavicular (TN), 12 calcaneo-cuboidal (CC), and 39 other smaller joints after arthrodesis in 72 patients were evaluated retrospectively regarding fusion grade in CT (0 = no fusion, 1 =  < 50% fusion, 2 =  > 50% fusion, 3 = complete fusion) and radiotracer uptake (0 = no uptake, 1 = mild uptake, 2 = moderate uptake, 3 = high uptake) on SPECT/CT. Severity of osteoarthritis (1 = mild, 2 = moderate, 3 = severe) and radiotracer uptake grade in adjacent joints was also assessed. In 54 patients, clinical information about interventions in the follow-up was available.

RESULTS

According to the SPECT/CT, arthrodesis was successful (grade 2 or 3 CT fusion and grade 0 or 1 uptake) in 73% (25/34) of UA joints, 71% (20/28) of LA joints, 67% (18/27) TN, 100% (12/12) CC joints, and 62% (24/39) of other smaller joints. In 12 joints, there were discrepant findings in SPECT/CT (fusion grade 2 and uptake grade 2 or 3 (n = 9); or, fusion grade 0 or 1 and uptake grade 1 (n = 3)). The fusion rate 6-12 months after arthrodesis was 42% (14/33), 59% (20/34) after 13-24 months, and 89% (65/73) after more than 24 months, respectively. Average radiotracer uptake in arthrodesis decreased with age: 6-12 months: 1.60, 12-24 months: 1.32,  > 24 months: 0.38. There was a significant negative correlation between radiotracer uptake grade and CT fusion grade. Osteoarthritis was observed in 131 adjacent joints. During the post scan follow-up, additional arthrodeses were performed in 33 joints, of which 11 joints were re-arthrodesis and 22 were new arthrodeses in osteoarthritic adjacent joints. All these 11 joints with failed arthrodesis had grade 0 of CT fusion and grade 2 or 3 of radiotracer uptake. All 22 adjacent joints with osteoarthritis, which subsequently underwent arthrodesis, had grade 2 or 3 radiotracer uptake, and the primary arthrodesis joints were healed and fused in all these cases.

CONCLUSION

Bone SPECT/CT is a valuable hybrid imaging tool in the evaluation of foot and ankle arthrodesis and gives additional useful information about the development of secondary osteoarthritis in the adjacent joints with higher value for the assessment of secondary osteoarthritis. A practical four-type classification ('Lucerne Criteria') combining metabolic and morphologic SPECT/CT information for evaluation of arthrodesis joints has been proposed.

Subtalar Arthrodesis in Patients With Prior Tibiotalar Arthrodesis for Posttraumatic Osteoarthritis

BACKGROUND

The tibiotalar arthrodesis for end-stage ankle osteoarthritis is a surgical procedure that leads to a modification of the kinematics of the adjacent joints and may result in the development of secondary osteoarthritic degeneration of the subtalar joint. It has previously been observed that subtalar arthrodesis in this context shows a lower fusion rate than isolated subtalar arthrodesis. This retrospective study reports the results of subtalar joint arthrodesis with previous ipsilateral tibiotalar arthrodesis and suggests some factors that may compromise the fusion of the joint.

METHODS

Between September 2010 and October 2021, 15 arthrodeses of the subtalar joint with screw fixation were performed in 14 patients, with a fusion of the ipsilateral tibiotalar joint. Fourteen of 15 cases used an open sinus tarsi approach, 13 were augmented with iliac crest bone graft, and 11 had supplemental demineralized bone matrix (DBM). The outcome variables were fusion rate, time to fusion, and revision rate. Fusion was assessed by radiographs and computed tomography scan.

RESULTS

Twelve of the 15 subtalar arthrodeses (80%) fused at the first attempt with an average fusion time of 4.7 months.

CONCLUSION

In this limited retrospective case series, compared to the fusion rate of isolated subtalar arthrodesis reported in the literature, the rate of subtalar fusion in the presence of an ipsilateral tibiotalar arthrodesis was found to be lower.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Blade Plate With Autogenous Bone Grafting to Salvage Peri Ankle Nonunions

BACKGROUND

Salvage surgery for a nonunion around the ankle is challenging. Poor bone stock, stiffness, scarring, previous (or persistent) infection, and a compromised soft tissue envelope are common in these patients. We describe 15 cases that underwent blade plate fixation as salvage for a nonunion around the ankle, including patient/nonunion characteristics, Nonunion Scoring System (NUSS), surgical technique, healing rate, complications, and long-term follow-up with 2 patient-reported outcome measures.

METHODS

This is a retrospective case series from a level 1 trauma referral center. We included all patients that underwent blade plate fixation for a long-standing nonunion of the distal tibia, talus, or failed subtalar fusion. All patients had autogenous bone grafting, including 14 with posterior iliac crest grafts and 2 with femoral reamer irrigator aspirator grafting. Median follow-up was 24.4 months (interquartile range [IQR], 7.7-40). Main outcome measures were (time to) union, and functional outcomes using the 36-item Short Form Health Survey (SF-36) physical component summary (PCS) and mental component summary (MCS), and the Foot and Ankle Outcome Score (FAOS).

RESULTS

We included 15 adults with a median age of 58 years (IQR, 54-62). The median NUSS score at the time of index surgery was 46 (IQR, 34-54). Union was achieved after the index procedure in 11 of 15 patients. Additional surgery was performed in 4 of 15 patients. Union was achieved in all patients at a median of 4.2 months (IQR, 2.9-11). The median score for the PCS was 38 (IQR, 34-48, range 17-58, P = .009), for the MCS 52 (IQR, 45-60, range 33-62, P = .701), and for the FAOS 73 (IQR, 48-83).

CONCLUSION

In this series, our use of blade plate fixation with autogenous grafting was an effective method for managing a nonunion around the ankle allowing for alignment correction, stable compression and fixation, union, and fair patient-reported outcome scores.

LEVEL OF EVIDENCE

Level IV, therapeutic.

High complication rates following revision first metatarsophalangeal joint arthrodesis: a retrospective analysis of 79 cases

BACKGROUND

The most common indications for revision of first metatarsophalangeal joint (MTPJ) arthrodesis are symptomatic failures of prior arthrodesis, failed hallux valgus correction, and failed MTPJ arthroplasty implants. However, the outcomes of revision MTPJ arthrodesis have rarely been studied. The purpose of this study was to compare the clinical, radiographic, and patient-reported outcomes of revision MTPJ arthrodesis following different primary procedures.

METHODS

A retrospective review of revision MTPJ arthrodesis cases between January 2015 and December 2019 was performed. The radiographic results, patient-reported outcomes, and rates of complications, subsequent revisions, and nonunions, were analyzed and compared preoperatively and postoperatively. A multivariate analysis was utilized to determine risk factors for complications and reoperations.

RESULTS

This study yielded a total of 79 cases of revision MTPJ arthrodesis. The mean follow-up time was 365 days (SD ± 295). The overall complication rate was 40.5%, of which the overall nonunion rate was 19.0%. Seven cases (8.9%) required further revision surgery. The multivariate analysis revealed that Diabetes mellitus was associated with significantly higher overall complication rates (p = 0.016), and nonunion was associated with "in-situ" joint preparation techniques (p = 0.042). Visual Analog Scale (VAS) significantly improved postoperatively (p < 0.001); However, PROMIS-10 physical health and PROMIS-10 mental health did not change significantly during the study period.

CONCLUSION

Treatment of MTPJ surgery failures is a clinical challenge in orthopedic surgery. In our study, revision of first MTPJ surgery resulted in higher nonunion rates and overall complication rates compared to typical outcomes from primary MTPJ arthrodesis. Diabetes, Tobacco use, and "in-situ" joint preparation technique were found to be independent risk factors for complications and reoperations.

LEVEL OF EVIDENCE

III-Retrospective Cohort Study.

Histopathological assessment of a two-stage reconstructive procedure of the infected Charcot foot

INTRODUCTION

Charcot neuropathic osteoarthropathy (CN) can be complicated by osteomyelitis (OM). Surgery is a standard procedure to treat OM including debridement and interposition of antibiotic-loaded cement (ABLC) spacer. The course of CN and OM was investigated on a histopathological level.

MATERIALS AND METHODS

Diabetic patients (n = 15) suffering from CN and midfoot OM underwent surgical debridement and interposition of ABLC was interposed. 6 weeks later, ABLC was removed and bone samples were taken again. Histopathological Charcot Score (HCS), Histopathological Osteomyelitis Evaluation Score (HOES) and microbiological assessment were used to evaluate osteomyelitic and neuroosteoarthropathic activity at both time points.

RESULTS

Interposition of ABLC leads to microbiological/histopathological eradication of OM in 73%/87% of patients. CN activity-measured by HCS-could be reduced from moderate to low activity by ABLC spacer and correlated with HOES.

CONCLUSIONS

CN activity could be reduced by surgery. It can be suggested that neuroosteoarthropathic activity measured by HCS is triggered by OM.

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.

A Retrospective Analysis of Outcomes From Foot and Ankle Arthrodesis and Open Reduction and Internal Fixation Using Cellular Bone Allograft Augmentation

BACKGROUND

ViviGen is an allogeneic cellular bone matrix product containing lineage-committed bone cells, and can be used as an alternative to autograft bone or other augments to aid in arthrodesis or to enhance bony healing in open reduction and internal fixation (ORIF) procedures.

METHODS

This study included 153 consecutive patients undergoing ankle, midfoot, or hindfoot arthrodesis or ORIF procedures from January 2017 to October 2018, in which an allogeneic cellular bone matrix product was used to aid in bony healing. Retrospective chart review identified patient demographic factors and medical comorbidities and evaluated clinical and radiographic data to determine fusion/union rate and complications.

RESULTS

The overall fusion rate for the arthrodesis cohort was 97/113 (85.8%). The overall complication rate in this cohort was 22/113 (19.5%). Smokers had significantly lower rates of fusion compared with nonsmokers (P = .01). The observed bony healing rate for the ORIF cohort was 19/22 (86.4%), with a complication rate of 3/22 (13.6%).

CONCLUSION

With satisfactory fusion rates and relatively few complications, our findings suggest that ViviGen is a safe and efficacious alternative to other forms of bone graft augmentation for fusion and ORIF procedures about the foot and ankle. Further study is needed to compare the efficacy of ViviGen with autograft bone and other augments.

LEVELS OF EVIDENCE

Level IV: Case series.

Larger sagittal inter-screw distance/tibial width ratio reduces delayed union or non-union after arthroscopic ankle arthrodesis

BACKGROUND

Arthroscopic ankle arthrodesis (AAA) has risks of complications, such as delayed union and non-union. The number and direction of the inserted screws have been reported as important factors affecting the time to union of AAA. However, the ratio of inter-screw distance (ISD) to tibial width (TW) in different planes has not been investigated. Therefore, we aimed to explore the effect of this ratio on bone union following AAA.

METHODS

We retrospectively enrolled 63 patients (64 ankles) undergoing AAA from 2013 to 2019. Then, their age, body mass index (BMI), sex, diabetes mellitus (DM) status, Takakura-Tanaka classification, number of screws and radiographic parameters were analysed.

RESULTS

The patients had a mean age of 70.3 (range, 45-91) years. Bone fusion was achieved in 57 ankles (89%) in a mean period of 3.3 (range, 2-6) postoperative months. There were four cases of delayed union and three of non-union. No significant differences in age, BMI, sex, DM, Takakura-Tanaka classification, and number of screws could be detected between the groups. However, the sagittal ISD/TW ratio was significantly larger in the union group than in the delayed/non-union group with a cut-off value of 57.0%.

CONCLUSION

Larger sagittal ISD/TW ratios result in reduced post-AAA delayed union or non-union. The surgeon should be aware that the anterior and posterior screw widths should be approximately 60% or more of the anteroposterior width of the tibia.

Does Concurrent Distal Tibiofibular Joint Arthrodesis Affect the Nonunion and Complication Rates of Tibiotalar Arthrodesis?

Tibiotalar arthrodesis successfully treats ankle arthritis but carries risk of nonunion. It is unclear whether concurrent distal tibiofibular arthrodesis affects tibiotalar nonunion rate. The purpose of this study is to compare tibiotalar nonunion and complication rates in patients with versus without a distal tibiofibular arthrodesis. This is a retrospective review of 516 consecutive ankle arthrodesis performed between March 2002 and May 2016. A total of 319 ankles (312 patients) underwent primary, open tibiotalar arthrodesis (227 with distal tibiofibular arthrodesis, 92 without). Primary outcome measure was nonunion rate. Secondary outcome measures were time to tibiotalar union, rate of development of post-operative deep vein thrombosis (DVT)/pulmonary embolism (PE), rate of deep wound complications, and rate of return to operating room (OR). No differences in nonunion rates were observed in both cohorts of patients with versus without distal tibiofibular arthrodesis: 17/227 (7.5%) versus 11/92 (12%) (p = 0.2), respectively, odds ratio was 0.74, 95% CI: 0.29~2.08 (p = 0.55). There was no difference in deep wound complications (5.3% versus 10.9%, p = 0.42), time to union (3.7 months versus 4.1 months, p = 0.72), or rate of development of DVT/PE (5.2% versus 2.2%, p = 0.18) between patients with and without distal tibiofibular arthrodesis, respectively. This is the first study directly comparing nonunion and complication rates in primary, open ankle arthrodesis with and without distal tibiofibular arthrodesis. Inclusion of the distal fibular joint with the tibiotalar fusion was not associated with a change in tibiotalar nonunion rate, time to union, wound complications, or postoperative DVT/PE.

Locked Dorsal Compression Plate Arthrodesis for Degenerative Arthritis of the Midfoot

Midfoot arthrodesis is the accepted surgical treatment for symptomatic midfoot arthritis. The published literature has focused on joint-spanning static fixation. Several companies have developed diamond-shaped locked dorsal compression plates, which allow for longitudinal joint compression. After dorsal plate insertion, a spreader device opens the arms of the plate mediolaterally, which allows the plate to compress longitudinally. This work describes outcomes of such locked dorsal compression plates for midfoot arthritis at a single institution. We reviewed 62 patients who underwent midfoot arthrodesis for symptomatic midfoot arthritis using locked dorsal compression plates over a 7-year period. A total of 173 joints were spanned for fusion. The primary outcome measure was radiographic union and visual analog scale pain scores. Characteristics of patients who experienced nonunion versus those who had union were evaluated. Of the 173 joints, there was a 81.5% fusion rate (141/173 joints) and 14 patients experienced nonunion. There was a statistically significant difference in the average number of joints spanned in patients with nonunion (3.6) and patients with union (2.5) (p = .02). Locked dorsal compression plate arthrodesis is a viable technique for achieving midfoot fusion. This mechanical method of compression does not, however, lend itself to improved fusion rates compared with prior reports. A greater number of arthrodesis sites is associated with a higher nonunion rate. Emerging technology using newer materials and improved biomechanical designs may show improved results.

Can a fibular malunion be corrected by a Z-shaped fibular osteotomy?

BACKGROUND

The aim of this study was to assess the short-term clinical and radiographic outcomes in patients who underwent realigning Z‑shaped fibular osteotomy.

METHODS

Between January 2007 and December 2014, 28 patients with a painful fibular malunion underwent a Z-shaped realignment fibular osteotomy. The mean age was 42.2 ± 14.1 years (range 19.1-67.8 years) and the mean follow-up was 7.0 ± 1.7 years (range 4.0-9.7 years), with no loss to follow-up. Weight-bearing radiographs were used to determine the distal fibula alignment based on Weber's criteria. Degenerative changes of the tibiotalar joint were assessed using the Kellgren-Lawrence scale. Clinical assessment included pain evaluation, measurement of ankle range of motion (ROM), sports activities, and quality of life outcomes.

RESULTS

There were no intraoperative or perioperative complications. No delayed unions or nonunions were observed. One patient had radiographic progression of degenerative changes in the tibiotalar joint. Postoperative complications included removal of hardware (n = 15) and arthroscopic tibiotalar joint debridement (n = 2). At the last follow-up the mean visual analog scale (VAS) decreased from 6.5 ± 1.1 to 2.1 ± 1.1 (p < 0.001),the ROM improved from 39º ± 6º to 45º ± 4.5º (p < 0.001), the short form health survey questionnaire (SF-36) physical and mental outcome scores improved from 49 ± 8 to 84 ± 7 (p < 0.001) and from 61 ± 4 to 83 ± 5 (p < 0.001), respectively.

CONCLUSION

The Z‑shaped realignment osteotomy of the distal fibula can provide pain relief and functional improvement in the treatment of fibular malunion. Further studies are needed to address long-term outcomes in this patient cohort.

A high-profile thread with grit-blasted and acid-etched surface reduces loosening of medial column fusion bolt in instable Charcot foot

BACKGROUND

Intramedullary fusion bolts (FB) were introduced to stabilize the medial column of the instable Charcot foot (ICF), but complications as bolt loosening or breakage are frequent. We compared the use of a standard FB and a high-profile threaded FB with a grit-blasted surface. We hypothesized that implant related complications occurred less often and osseous consolidation of fusion sites was more distinctive using the latter type of FB.

METHODS

Consecutive patients suffering from an ICF were stabilized with a high-profile threaded and surface-modified FB (HTFB) (n=20) or with a standard FB (n=20) which was placed into the first ray. Additional bolts and dorsal low-profile plates were applied in every patient. In a retrospective assessment osseous consolidation of the fusion sites was analyzed at 3 month and quantified by CT scan. At 3 and 12 month longitudinal foot arch collapse and rate of bolt loosening were assessed.

RESULTS

Compared to the control group, the HTFB group reached significant higher consolidation after 3 month. No dislocation and a single bolt breakage was observed in the HTFB group after the fourth month, while the control group included 3 patients with bolt dislocation at 3±1 month and 5 patients with bolt breakage at 6±1.8 month. Compared to preoperative values, the improvement of Meary's angle after one-year was significant higher in the HTFB group (23.4°±14) than in controls (11.7°±13).

CONCLUSIONS

Modification of bolt design improves the stability of the medial column: A higher rate of osseous consolidation of the medial column leads to lower rate of bolt dislocation/breakage and finally to permanently erected longitudinal foot arch. Initially disappointing results following medial column stabilization with fusion bolts can be rejected by modifications of bolt design and its technical application.

Ankle Arthroscopy as an Adjunctive Method for Diagnosis of Nonunion After Tibiotalar Arthrodesis

The definition of consolidation after ankle arthrodesis can be challenging in some situations. Computed tomography has increased diagnostic accuracy; however, there are still no clear criteria for nonunion. In this context, arthroscopy with direct visualization of the arthrodesis may provide crucial data to inform the choice of treatment. The present report illustrates a case in which arthroscopy prompted a change in treatment strategy. More extensive surgery, with the potential for greater morbidity due to revision arthrodesis, could be avoided.

Tibiotalocalcaneal Arthrodesis Utilizing a Titanium Intramedullary Nail With an Internal Pseudoelastic Nitinol Compression Element: A Retrospective Case Series of 33 Patients

Nitinol has been shown to generate durable compression under loading via pseudoelastic shape memory. The purpose of this study was to evaluate the effectiveness of a hindfoot arthrodesis nail with an internal pseudoelastic nitinol compression element. Patients who had undergone tibiotalocalcaneal arthrodesis from 2013 to 2016 were identified at 2 tertiary referral centers (12-week follow-up minimum). Patients managed with a tibiotalocalcaneal nail with an internal nitinol compression element were identified for review. Sagittal computed tomographic scan reformats were reviewed to calculate a percentage of joint surface bony union. Intraoperative and postoperative radiographs were compared to calculate postoperative screw position change generated by the nitinol element, a surrogate for postoperative unloading of compressive forces. Thirty-three patients were included in analysis and 81% of patients had successful union of both tibiotalar and subtalar joints. Overall, 90% of all arthrodesis surfaces united. The union rate of arthrodesis surfaces among patients without Charcot osteoarthropathy was 94%. A history of Charcot was identified as a risk factor for subtalar nonunion (p = .04) and was associated with less complete computed tomography-based tibiotalar union: 94% versus 71% (p < .01). The posterior-to-anterior screw translated an average of 3.9 mm proximally relative to the rigid portion of the nail from intraoperative to initial postoperative radiographs (p < .0001). High rates of computed tomography-confirmed union were demonstrated in the face of challenging clinical scenarios. Shortening of the pseudoelastic nitinol element occurs early in the postoperative period, indicating continued unloading of the nitinol compression element through the arthrodesis sites after initial implantation.

Early Clinical and Radiographic Outcomes of Trabecular Metal Total Ankle Replacement Using a Transfibular Approach

BACKGROUND

In the last 2 decades, total ankle replacement has gained greater acceptance as a treatment option in patients with end-stage ankle osteoarthritis. However, there is a lack of literature on total ankle replacement using a lateral transfibular approach. Therefore, we sought to report early clinical and radiographic results for a patient cohort treated with total ankle replacement using a lateral transfibular approach, performed by a single surgeon.

METHODS

From October 2012 to December 2014, 55 primary total ankle arthroplasties using the Zimmer Trabecular Metal Total Ankle implant were performed in 54 patients (29 male and 25 female; mean age, 67.0 years). Clinical assessment, including pain evaluation and measurement of ankle range of motion, was conducted preoperatively and at the latest follow-up. Weight-bearing radiographs were used to determine angular alignment of the tibial and talar components and to analyze the bone-implant interface. Intraoperative and postoperative complications, revision surgeries, and survivorship were evaluated.

RESULTS

Implant survival was 93% at 24 months of follow-up. There were 3 revisions of a tibial component due to aseptic loosening. In 10 of the 55 cases, a secondary procedure was performed during follow-up. The mean follow-up duration was 26.6 ± 4.2 months. No delayed union or nonunion was observed for fibular healing. The average visual analog scale (VAS) pain score decreased significantly, from 7.9 ± 1.3 to 0.8 ± 1.2. The average total range of motion increased significantly, from 22.9° ± 12.7° to 40.2° ± 11.8°.

CONCLUSIONS

Early results of total ankle replacement using the Zimmer trabecular metal implant and the lateral transfibular approach demonstrated improved patient-reported outcomes and increased ankle motion at a minimum follow-up of 2 years. In the 55 consecutive cases, the fibular osteotomy required for access to the ankle healed without complications. Painful early loosening due to lack of osseous ingrowth required revision in 3 of 55 cases.

LEVEL OF EVIDENCE

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

Hybrid Fixation for Ankle Fusion in Diabetic Charcot Arthropathy

BACKGROUND

Ankle fusion is difficult to achieve in the diabetic Charcot ankle Brodsky type 3a because of the poor quality of the bone and the inability to achieve a stable biomechanical construct. The aim of this study was to report the outcome of ankle fusion using a combination of an intramedullary nail and a circular external fixator in patients with diabetic Charcot arthropathy.

METHODS

We prospectively studied 24 patients with diabetic Charcot arthropathy of the ankle who were treated by fusion of the tibiotalar joint using a combined retrograde intramedullary nail and Ilizarov external fixator. Their mean age was 50.7 ± 6.9 (range, 43-62) years. The mean follow-up after surgery was 36.4 ± 5.8 (range, 24-98) months.

RESULTS

Twenty-two patients (92%) achieved clinical and radiographic solid bony fusion. No patients in this series needed amputation. All the patients were pain free, and the mean American Orthopaedic Foot & Ankle Society Score (AOFAS) improved significantly from 34.6 ± 6.8 to 66.4 ± 4.5 at the last follow-up. Two patients developed an ulcer over the heel due to a prominent nail. The ulcer healed after nail removal. Eight patients developed pin tract infection.

CONCLUSION

We report a successful outcomes of ankle fusions using combined intramedullary nail locked only proximally and ring external fixator (hybrid fixation) in patients with diabetic Charcot arthropathy.

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.

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

BACKGROUND

Patients with arthritis or severe dysfunction involving both the ankle and subtalar joints can benefit from tibiotalocalcaneal (TTC) arthrodesis or total ankle replacement and subtalar fusion. TTC fusion is considered by many as a salvage operation resulting in a stiff ankle and hindfoot, considerably limiting global foot function. With the evolution of prosthetic design and operative techniques, total ankle replacement (TAR) has become a reasonable alternative to arthrodesis. The aim of this study was to investigate the fusion rate of the subtalar joint in patients simultaneously treated with total ankle replacement (TAR) and subtalar joint fusion.

METHODS

This study included 25 patients who underwent primary TAR and simultaneous subtalar fusion between May 2011 and November 2014. Sixteen males (64%) and 9 females (36%) were enrolled with a mean age of 58 years (25-82). Patients were clinically assessed preoperatively and at 6 and 12 months postoperatively. Total follow-up time was 24.2 ± 11.6 months. Radiographic examination included a postoperative computed tomographic (CT) scan obtained 12 months after surgery. Three surgeons independently reviewed the CT scans and interobserver reliability was calculated. Functional scores were also assessed.

RESULTS

At 12 months postoperatively, the subtalar fusion rate in patients treated with TAR and simultaneous subtalar fusion was 92%. There was a statistically significant increase in American Orthopaedic Foot & Ankle Society ankle/hindfoot score from 27.9 to 75.1. Ankle range of motion significantly increased from 12 to 32.8 degrees. Additionally, there was a statistically significant decrease in visual analog scale pain score from 8.6 to 2.1.

CONCLUSIONS

TAR and simultaneous subtalar joint fusion were reliable procedures for the treatment of ankle and subtalar joint arthritis. Furthermore, CT scans showed an excellent reliability among orthopedic surgeons in determining the degree of successful fusion of subtalar arthrodesis.

LEVEL OF EVIDENCE

Level IV, case series.

Reliability of the Radiographic Sagittal and Frontal Tibiotalar Alignment after Ankle Arthrodesis

Background

Accurate measurement of the tibiotalar alignment is important in radiographic outcome assessment of ankle arthrodesis (AA). In studies, various radiological methods have been used to measure the tibiotalar alignment leading to facultative misinterpretation of results. However, to our knowledge, no previous study has investigated the reliability of tibiotalar alignment measurement in AA. We aimed to investigate the reliability of four different methods of measurement of the frontal and sagittal tibiotalar alignment after AA, and to further clarify the most reliable method for determining the longitudinal axis of the tibia.

Methods

Thirty-eight weight bearing anterior to posterior and lateral ankle radiographs of thirty-seven patients who had undergone AA with a two screw fixation technique were selected. Three observers measured the frontal tibiotalar angle (FTTA) and the sagittal tibiotalar angle (STTA) using four different methods. The methods differed by the definition of the longitudinal tibial axis. Method A was defined by a line drawn along the lateral tibial border in anterior to posterior radiographs and along the posterior tibial border in lateral radiographs. Method B was defined by a line connecting two points in the middle of the proximal and the distal tibial shaft. Method C was drawn „freestyle”along the longitudinal axis of the tibia, and method D was defined by a line connecting the center of the tibial articular surface and a point in the middle of the proximal tibial shaft. Intra- and interobserver correlation coefficients (ICC) and repeated measurement ANOVA were calculated to assess measurement reliability and accuracy.

Results

All four methods showed excellent inter- and intraobserver reliability for the FTTA and the STTA. When the longitudinal tibial axis is defined by connecting two points in the middle of the proximal and the distal tibial shaft, the highest interobserver reliability for the FTTA (ICC: 0.980; CI 95%: 0.966–0.989) and for the STTA (ICC: 0.997; CI 95%: 0.996–0.999) is provided. Intergroup analysis for FTTA measurements revealed a statistically significant difference between the method in which the lateral border of the tibia was used to determine the longitudinal axis of the tibia, and the other methods in which the longitudinal axis was defined by bisecting the tibia.

Conclusions

When the longitudinal axis of the tibia is defined by connecting two points in the middle of the proximal and the distal tibial shaft for measuring the FTTA and STTA, the most favorable interobserver reliability is provided. Therefore, this method can be recommended for evaluating the frontal and the sagittal alignment on anterior to posterior and lateral radiographs after ankle arthrodesis.