TTC Fusion Research Articles

Factors affecting the outcomes of tibiotalocalcaneal fusion.

Tibiotalocalcaneal (TTC) fusion is used to treat a variety of conditions affecting the ankle and subtalar joint, including osteoarthritis (OA), Charcot arthropathy, avascular necrosis (AVN) of the talus, failed total ankle arthroplasty, and severe deformity. The prevalence of postoperative complications remains high due to the complexity of hindfoot disease seen in these patients. The aim of this study was to analyze the relationship between preoperative conditions and postoperative complications in order to predict the outcome following primary TTC fusion. We retrospectively reviewed the medical records of 101 patients who underwent TTC fusion at the same institution between 2011 and 2019. Risk ratios (RRs) associated with age, sex, diabetes, cardiovascular disease, smoking, preoperative ankle deformity, and the use of bone graft during surgery were related to the postoperative complications. We determined from these data which pre- and perioperative factors significantly affected the outcome. Out of the 101 patients included in the study, 29 (28.7%) had nonunion, five (4.9%) required below-knee amputation (BKA), 40 (39.6%) returned to the operating theatre, 16 (15.8%) had hardware failure, and 22 (21.8%) had a postoperative infection. Patients with a preoperative diagnosis of Charcot arthropathy and non-traumatic OA had significantly higher nonunion rates of 44.4% (12 patients) and 39.1% (18 patients) (p = 0.016) and infection rates of 29.6% (eight patients) and 37% (17 patients) compared to patients with traumatic arthritis, respectively (p = 0.002). There was a significantly increased rate of nonunion in diabetic patients (RR 2.22; p = 0.010). Patients with chronic kidney disease were 2.37-times more likely to have a nonunion (p = 0.006). Patients aged over 60 years had more than a three-fold increase in the rate of postoperative infection (RR 3.60; p = 0.006). The use of bone graft appeared to be significantly protective against postoperative infection (p = 0.019). We were able to confirm, in the largest series of TTC ankle fusions currently in the literature, that there remains a high rate of complications following this procedure. We found that patients with a Charcot or non-traumatic arthropathy had an increased risk of nonunion and postoperative infection compared to individuals with traumatic arthritis. Those with diabetes, chronic kidney disease, or aged over 60 years had an increased risk of nonunion. These findings help to confirm those of previous studies. Additionally, our study adds to the literature by showing that autologous bone graft may help in decreasing infection rates. These data can be useful to surgeons and patients when considering, discussing and planning TTC fusion. It helps surgeons further understand which patients are at a higher risk for postoperative complications when undergoing TTC fusion. Cite this article: Bone Joint J. 2020;102-B(3):345-351.

Outcomes of Defect Management at Tibiotalocalcaneal Fusion Treated with Innovative ‘Bamboo Hut’ Technique

Category:HindfootIntroduction/Purpose:Tibiotalocalcaneal (TTC) fusion is a salvage procedure for post-traumatic as well as neuropathic cases. Many of these cases are characterised by some or other form of loss of talus resulting in a defect. At TTC fusion, prevention of shortening following such a defect is a challenge. Though allografts have helped solve this issue, they may not be easily available in developing countries. A retrospective analysis of prospectively collected data of 14 cases of TTC fusion with loss of talus is presented here. Cases were managed with innovative defect bridging ‘Bamboo Hut’ technique.Methods:Cases with either preoperative or perioperative loss of talus who required bridging of defect were included in the present study. Resultant defect following excision of the talus was bridged with two or three vertically placed fibular strut grafts. Grafts were snugly tied with each other with sutures to prepare a construct like a hut supported with wooden steaks (Bamboo). Fixation was carried out with indigenous TTC nail with a built-in compression device to generate compression of grafts between tibia and calcaneus.Results:Present series comprised of 6 post-traumatic cases, 7 cases of diabetic Charcot neuroarthropathy and 1 case of neuroarthropathy following operated meningomyelocele. Cases were followed up for an average period of 36 months with the average time to union being six months. All posttraumatic cases went on to the bony union but two out of eight neuropathy cases ended up in fibrous union with collapse & loss of fixation. Wound healing issues were noticed in two cases. None of the cases required amputation.Conclusion:With non-availability of allografts, prevention of shortening at TTC fusion is a challenge. This issue can be successfully managed with innovative ‘Bamboo Hut’ grafting technique, supported with in-built compression of the fusion site with the use of an indigenous nail.

Comparison of Custom 3D Printed Spherical Implants vs Femoral Head Allografts for Tibiotalocalcaneal Arthrodeses

Category:Ankle Arthritis, HindfootIntroduction/Purpose:Tibiotalocalcaneal (TTC) arthrodesis is a common treatment option for hindfoot arthritis, deformity correction and salvage of failed total ankle replacement. However, union can be difficult to achieve in patients with bulk bone defects. Femoral head allograft is commonly used in the setting of TTC fusion with severe bone loss, but recent studies have reported concerns of arthrodesis rates of 50% or worse and graft collapse in these patients. Retrograde intramedullary nail placement through custom 3D spherical implants is a novel option for these patients. The purpose of this study was to compare fusion rates, graft resorption and complication rates between patients undergoing TTC fusion with 3D sphere implants versus femoral head allografts.Methods:All patients who underwent TTC arthrodesis with an intramedullary nail along with a 3D spherical implant or femoral head allograft by the senior author at a single institution from 2013 to 2017 and who had at least one year of follow-up were included in this study. There were 7 patients who received a femoral head allograft and 8 patients who received a 3D printed sphere. Baseline patient and operative characteristics were collected and compared between the 3D sphere and femoral head allograft groups. The rate of successful fusion of the tibia, calcaneus and talar neck to the 3D sphere or femoral head allograft, as determined by radiographs and CT scan, as well as graft resorption and complications were compared between the groups.Results:The rates of union of the tibia (87.5% vs 71.4%), calcaneus (87.5% vs 71.4%), and talar neck (100% vs 42.9%) were higher in the 3D sphere group than in the femoral head allograft group. The rate of union of the talar neck was significantly higher to the 3D sphere implant than to the femoral head allograft (p=0.016). The number of patients achieving successful fusion of all three articulations was higher in the 3D sphere group (75%) than the femoral head allograft group (42.9%), although not statistically significant (p=0.22). The rate of graft resorption was significantly higher in the femoral head allograft group (57.1%) than the 3D sphere group (0%, p=0.016).There were no differences between the groups in terms of complications.Conclusion:These data demonstrate that the use of a custom 3D-printed sphere implant is safe in patients with severe bone loss undergoing TTC arthrodesis with a retrograde intramedullary nail. The rate of successful fusion of all three tibial, calcaneal and talar neck articulations was higher to the 3D sphere than to the femoral head allograft, although not statistically significant. Union of the talar neck was significantly higher to the 3D sphere implants than it was to the femoral head allograft. Subsidence was significantly higher with the femoral head allograft than the 3D sphere.

3D Printed Cage in Patients with Tibiotalocalcaneal Arthrodesis Using a Retrograde Intramedullary Nail: Early Outcomes

Category:Diabetes, Hindfoot, Trauma, salvage procedureIntroduction/Purpose:Segmental bone loss in the hindfoot hinders the chance of successful outcomes. Tibiotalocalcaneal arthrodesis is a reliable option; however, the risk of nonunion is high. Structural graft is needed to fill the gap, but the use of bone grafts are limited by the availability, risk of collapse, and disease transmission. Three-dimensional (3D) printed titanium implants offer a strong scaffold that can be customized and present similar healing rates. The purpose of the study was to describe the clinical outcomes and the radiologic union rate of a case series of patients with hindfoot arthrodesis, using a retrograde intramedullary nail associated to a 3D printed titanium cage.Methods:After obtaining approval from our institution review board, a retrospective chart review was performed on seven patients undergoing hindfoot arthrodesis, using a retrograde intramedullary nail associated to a custom 3D printed titanium cage from March 2015 to December 2017. Demographic and clinical data were collected. Functional outcomes were assessed using The American Orthopedic Foot and Ankle Score (AOFAS) and the Visual Analog Scale (VAS) for pain. Hindfoot alignment was evaluated using preoperative and postoperative weightbearing radiographs that included anteroposterior, lateral and Saltzman views. Radiographic union was assessed using computed tomography scan at 6 and 12 months postoperatively.Results:All patients had ankle arthritis and six of them (85%) had prior surgery in the compromised hindfoot. The average age at TTC fusion was 57 (range, 29 to 71) years. The mean follow-up time was 21 (range, 12 to 32) months. Six patients had a healed fusion and one patient underwent below knee amputation due to recurrence of chronic osteomyelitis in the ankle. Two additional patients had minor complications. The average AOFAS at pre-op was 35 (range, 20 to 42) points as compared to 68 (range, 53 to 78) points at final follow-up; P=0.004. Preoperative VAS pain was 80.4 (range, 70 to 85) points as compared to 26.8 (range, 6 to 60) points; P=0.002.Conclusion:Tibiotalocalcaneal arthrodesis using customized titanium cages for patients with large bone defects has shown a high rate of union in those at high risk of nonunion. Further research is needed to monitor the development of late complications.

Ankle Arthrodesis With Structural Grafts Can Work for the Salvage of Failed Total Ankle Arthroplasty.

Background. Treatment options after failed total ankle arthroplasty (TAA) are limited. This study reports midterm outcomes and radiographic results in a single-surgeon group of patients who have undergone ankle arthrodesis with intramedullary nail fixation and structural allograft augmentation following failed TAA. Methods. A retrospective review on patients who underwent failed TAA revision with structural femoral head allograft and intramedullary tibiotalocalcaneal (TTC) nail fixation was completed. Foot Function Index (FFI), American Orthopaedic Foot & Ankle Society (AOFAS) outcome scores, and radiographs were obtained at each visit with 5-year follow-up. Results. Five patients were followed to an average of 5.2 years (range 4.7-5.6). Enrollment FFI was 34.82 (range 8.82-75.88); at midterm follow-up it was 20.42 (range 0-35.38). Enrollment AOFAS scores averaged 66.6 (range 61-77); at midterm follow-up it was 70.33 (range 54-88). Radiographs showed union in 4 of 5 patients at enrollment and 2 of 3 patients at midterm. Conclusions. Utilization of TTC fusion with femoral head allograft is a salvage technique that can produce a functional limb salvage. Our results show continued improvement in patient-reported outcomes, with preservation of limb length and reasonable union rate. Levels of Evidence: Therapeutic, Level II: Prospective, comparative trial.

Case Series: Allograft Tibiotalocalcaneal Arthrodesis Utilizing Fresh Talus.

Background:Talar body osteonecrosis can be a difficult condition to treat. Recent reports highlight a high rate of failure with the use of femoral head allograft. Additionally, higher rates of failure have been reported in diabetics and smokers. Our institution attempted a novel technique utilizing fresh allograft talus in attempt to improve on a reported 50% nonunion rate.Methods:Five patients who underwent tibiotalocalcaneal (TTC) fusion utilizing fresh talar allograft were clinically and radiographically reviewed to evaluate fusion rates and functional outcomes.Results:Our case series of 5 patients had a 100% union rate, including 2 former smokers and 2 diabetic patients. There were no infections or complications. Functional outcomes also improved in our series of patients postoperatively as noted by their FAAM and SF-36 scores.Conclusion:TTC fusion using fresh allograft talus has a higher union rate than reported with femoral head allograft. This case series requires further study to evaluate whether this technique can be used beyond patients with osteonecrosis of the talus.Level of Evidence:Level IV, case series.

Tibiotalocalcaneal Arthrodesis Using a Straight Intramedullary Nail

Category: Hindfoot Introduction/Purpose: Tibiotalocalcaneal (TTC) arthrodesis using a hindfoot intramedullary nail has been shown to be a safe and reliable technique in patients with severe ankle and hindfoot disease. There is debate about the use of straight nails versus curved nails. Proponents of the curved nail argue that straight nails predispose to greater risk of lateral plantar nerve injury, poor calcaneal bone purchase and inability to maintain satisfactory hindfoot valgus alignment. However, the subtalar joint is a condyloid joint enabling rotation of the talus on the calcaneum to create varus/valgus position of the calcaneal tuberosity. We present a clinical series of patients undergoing TTC fusion using a straight nail assessed by clinical and radiological outcomes to establish whether theoretical risks of straight nails are reflected in clinical practice. Methods: This single centre, retrospective study of prospectively collected data on a sequential series of patients to undergo TTC fusion, with pre and post-operative weight bearing CT imaging. Data was collected on indication for procedure, co-morbidities, post-operative complications, union rate as well as clinical scores, EQ5D and MOXFQ. Weight bearing CT imaging was analysed using the validated TALUS™ (torque ankle lever arm system) method on weight bearing CT, providing calcaneal offset, hindfoot angle and hindfoot alignment. These were used as markers of hindfoot alignment. Results: 65 patients (37 males, 28 females) were included in the study, with an average age of 57 years. Average follow-up was 20 months. Indications for TTC fusion included Charcot arthropathy, talar avascular necrosis, post traumatic arthritis and non-union of previous arthrodeses. Union rate was 91% (59/65). Overall complication rate was 11% (7/65) and most were minor wound complications. There were no plantar nerve injuries noted. There were no nail cut outs from the calcaneum. On all markers of hindfoot alignment, cases showed a more physiological degree of hindfoot valgus compared to pre-operative measures. There were significant improvement in both EQ5D and MOXFQ scores (p<0.05). Conclusion: We present the largest series of TTC fusion using a straight intramedullary nail and the first series to analyse hindfoot alignment using weight bearing 3D CT imaging. Our data regarding correction of hindfoot alignment is supported by biomechanical theories of subtalar varus/valgus, being related to rotatory changes at the subtalar joint, questioning the perceived need for a curved nail. This is particularly at the level of the entry point of the nail. The principles of valgus hindfoot nails are based on biomechanical laboratory studies and cadaveric studies, neither of which reflect our findings in clinical practice.

Tibiotalocalcaneal Fusion Rate with a Novel Pseudoelastic Intramedullary Nail with NiTiNOL

Category: Ankle Arthritis Introduction/Purpose: Tibiotalocalcaneal (TTC) fusion is a salvage operation for patients with significant arthritis and deformity of ankle and subtalar joints. Despite overall clinic success, fusion across both joints continues to be a major challenge with nonunion rates reported up to 48% [Franceschi]. Aside from certain patient comorbidities, nonunion may result when compression across the joint is lost in the setting of bone resorption. The use of a pseudoelastic intramedullary nail has been shown to maintain compression across fusion site in response to bone resorption. The purpose of this study was to evaluate the fusion rate in a high-risk population at a tertiary care center using a psuedoelastic intramedullary nail with an internal nitinol element. Methods: After obtaining IRB approval, a retrospective review of consecutive patients that underwent procedures with TTC fusion with novel intramedullary nail system with super elastic internal nickel titanium (NiTiNOL, DynaNail, Medshape Inc, Atlanta, GA) was performed at a single academic institution. From 2014 to 2016, 58 patients were identified, 55 of which had minimum one year follow up or clinical and radiographic fusion (20 months average, range 6-41 months). The primary outcome was radiographic fusion analysis which was reviewed by three authors. Fusion was determined by consensus with criteria of 3 of 4 cortices with osseous bridging in asymptomatic patients[1, 2] or CT fusion based on Glazebrook et. al. criteria for hindfoot fusion[3, 4]. Average age of this cohort was 59 (SD= 16.3) years with BMI average 33.1 (SD= 8.87). Exclusion criteria include: follow-up less than 12 months in non-fused patients, and incomplete clinical or radiologic data. Results: The fusion rate in this high-risk population was 80.0% with the use of the NiTiNOL tibiotalocalcaneal nailing system. Univariate analysis demonstrated no significant difference (p>0.05) in fusion rates with patient comorbidities that portend to non-union: current or former history of tobacco use, diabetes mellitus, rheumatoid arthritis, nor patients with chronic kidney disease. The average BMI in the fusion group was 31.97 compared to 27.4 in the non-union group (p=0.016). There were 5 deep infections requiring reoperation with a single patient requiring a below the knee amputation. Seven patients required a second operation for removal of prominent interlocking screws. Conclusion: This preliminary data demonstrates fusion rates with this novel intramedullary device are consistent with historical data. These findings are encouraging in that this nailing system shows equal rates of fusion in patients with high risk comorbidities for non-union compared to historical controls demonstrating increased non-union rates in diabetics, patients with chronic renal failure and those with a history of smoking. This Tibiotalocalcaneal nailing system is safe and offers theoretical sustained compression with up to 6 mm of resorption or settling.

Prognostic risk factors for complications associated with Tibiotalocalcaneal fusion with a nail

Category: Ankle Introduction/Purpose: Tibiotalocalcaneal (TTC) fusion with a nail is an effective salvage procedure for several foot and ankle pathologies, but it is associated with a relatively high complication rate and often performed on patients with multiple medical comorbidities. There is a paucity of literature that aids in predicting outcomes for patients undergoing TTC fusion with a nail. Methods: Clinical and radiographic outcomes for 82 patients from 2012-2016 who underwent TTC fusion with intramedullary nailing were retrospectively evaluated. Postoperative complications of nonunion, infection, reoperation, and hardware failure were included for comparison. Patient dependent variables and surgeon dependent variables were evaluated for association with these postoperative complications. Results: The overall complication rate for TTC fusion with a nail was 47/82 (57.3%). Diabetes (p=.049), diabetic neuropathy (p=.031), ASA classification (p=.005), and Charcot neuropathy (p=.003) were associated with nonunion of either the tibiotalar or subtalar joints in 29/82 (35.3%) patients. Diabetic neuropathy was associated with need for reoperation (p=.016) in 21/82 (25.6%) patients. Diabetic neuropathy (p=.022) and HbA1C >7.5 (p=.047) was associated with hardware failure in 13/82 (15.9%) patients. The odds ratio (OR) for diabetic neuropathy was 2.99 (p=0.038) for nonunion in the tibiotalar or subtalar joints, 3.46 (p=0.021) for re-operation, and 4.11 (p=0.035) for hardware failure. High ASA classification had an odds ratio of 3.93 (p=0.006) for nonunion in the tibiotalar or subtalar joints. Conclusion: Patients with diabetic neuropathy, Charcot neuropathy, elevated HbA1C, and higher ASA classification demonstrated a higher complication rate in patients undergoing TTC fusion with a nail.

Tibiotalocalcaneal arthrodesis with distal tibial allograft for massive bone deficits in the ankle

BackgroundThe purpose of this study was to assess the outcomes of distal tibial structural allograft to obtain a stable TTC fusion. MethodsRetrospectively, ten patients were carried out with a minimum one year follow-up. The median age was 72 (33–81). The median BMI was 28 (24–33). Indications for TTC arthrodesis included failed total ankle arthroplasty (n=7 patients), prior nonunion (n=2 patients), and a trauma injury. ResultsUnion rate was 80%. The median initial height of the distal tibial allograft was 19mm (14–24mm). In seven cases the allograft did not lose height. The AOFAS score median was 69 (31–84). SF-12 median physical component was 39 (30–53), and 59 (23–62) for mental component. The VAS median was 2 (0–8). ConclusionsTTC using distal tibial allograft shows a lower rate of collapse than other structural grafts and provides a fusion rate higher or in accordance with the literature. Level of evidenceLevel IV, retrospective case series.

Tibiotalocalcaneal Arthodesis via a Nitinol Containing Intramedullary Nail

Category: Ankle, Ankle Arthritis, Hindfoot Introduction/Purpose: Tibiotalocalcaneal (TTC) arthrodesis is a common procedure used in the management of foot and ankle pathologies. TTC fusions are frequently performed in patients with limited bone stock and poor vascular status. Adequate compression at the arthrodesis site is vital to successful fusion as even small amounts of bone resorption greatly increase nonunion risk. A recently designed hindfoot nail contains a built in nickel titanium alloy (nitinol) that has psuedoelastic properties which maintains compression across joint surfaces in the setting of bone resorption. The authors present a case series of patients who were managed with this nitinol containing intramedullary hindfoot nail system. Methods: Patients treated by one board certified orthopaedic foot and ankle surgeon who were managed with the nitinol containing hindfoot nailing system were retrospectively reviewed over a two year span. Electronic medical records were reviewed to collect demographic information and details regarding the patient’s procedure. Operative specifics collected included the data of the procedure and the preoperative diagnosis. Records were reviewed postoperatively as well to document the incidence of postoperative complications and functional outcomes. Proximal migration of the distal interlocking screw on lateral radiographs were measured in a standardized fashion at two, six, and twelve weeks to objectively assess additional compression obtained through the nitinol nailing system. Results: Eight patients were included in the case series with an average follow up time of 7 months postoperative (minimum of 4 months for one patient). The most common preoperative diagnosis was posttraumatic arthritis (n = 4). One patient suffered from wound dehiscence postoperatively that required operative intervention within the first three months – this patient’s wound healed by six months with no further complications. All patients were cleared for full weight bearing and activities as tolerated by six months, except only had four months of follow up available. The compression obtained through this nailing system increased at each follow up for all patients. The average compression obtained was 2.9 mm at two weeks, 3.8 mm at six weeks, and 4.4 mm at twelve weeks. Conclusion: Tibiotalocalcaneal arthrodesis can be an excellent procedure that provides significant pain relief and restores function. The patients in this case series all had excellent results with only one postoperative complication that ultimately did not result in any functional deficits. Furthermore, patients all demonstrated increased compression at each follow up radiographs which demonstrates the sustained compression obtained at the arthrodesis site through this hindfoot nail system. Further prospective work with a larger patient cohort is warranted to determine if this nailing system is superior to other TTC hindfoot nails.

Patient-Specific Finite-Element Analysis of Three Intramedullary Nails for Tibiotalocalcaneal Fusion

Category: Ankle, Hindfoot Introduction/Purpose: Tibiotalocalcaneal (TTC) arthrodesis is a salvage procedure for patients with severe osteoarthritis and other degenerative ankle conditions. Oftentimes, an intramedullary (IM) nail is implanted across the joints and then fixed with tibial and calcaneal screws. Maintaining compression and load sharing are both largely desired to promote fusion via primary bone healing; however, compression can be lost due to small amounts of bone resorption and IM nails are now being made from carbon-fiber epoxy to minimize stress shielding. To date, no one has been able to directly characterize or compare the specific amount of these parameters across nails in a single model. The purpose of this study is to compare influence of nail design and materials for compressive and load-sharing properties using a patient-specific finite-element model. Methods: A titanium nail, a pseudoelastic nickel-titanium nail, and carbon fiber-epoxy nail were investigated for (1) load sharing between the nail body and tibia under gait loading and (2) compression loss as a function of resorption in the talus. A patient- specific model of the ankle, both in geometry and material properties, was generated from a quantitative computed tomography (QCT) scan of a healthy leg. The models were segmented and meshed using SCANIP and exported into ABAQUS for finite- element analysis. Compression in the nickel-titanium nail was simulated by pre-stretching the pseudoelastic compressive element. Conversely, compression in the titanium and carbon-fiber nails were generated by giving the nail jacket an orthotropic contraction coefficient in the model. After compression was set, each nail was subjected to an applied gait load that peaked at 1121 N. Resorption was simulated using a thin compressible layer of bone in the talus and decreasing the modulus and Poisson’s ratio. Results: Surprisingly, the carbon-fiber nail showed similar stress shielding to the titanium nail, with 72% and 77% of the stress being transferred through the devices instead of the ankle, respectively. Even though carbon fiber-epoxy has a significantly lower modulus than titanium (75 GPa vs 110 GPa), the overall stiffness of the nails was still much greater than that of bone (~30,000 N/mm vs. ~44,000 N/mm vs. ~3,000 N/mm, respectively). The pseudoelastic nail only shielded 32% of the stress values by comparison. For the titanium and carbon-fiber nails, over 85% of the initial compression provided by the nail drops with 0.10 mm of resorption. The pseudoelastic nail maintained 90% of its initial compression after 0.10 mm of resorption. Conclusion: IM nail design and materials played a significant role in maintaining compression and load sharing. The pseudoelastic nail had the lowest degree of stress-shielding (32%) and maintained compression for over 0.10 mm of simulated resorption. Constant compression and the avoidance of “resorption gapping” is paramount to drive primary bone healing in joint fusions due to lack of periosteal/endosteal anatomy crossing the fusion site, thus impairing the ability for secondary bone healing (callus healing). This model allows for direct comparison between devices and can be used pre-operatively to predict patient-specific performance and help aid in device selection for TTC fusion.

Curved Retrograde TTC Fusion Nails

Category: Hindfoot Introduction/Purpose: Retrograde intramedullary nailing is an established surgical procedure for tibiotalocalcaneal (TTC) fusion. The clinical incidence of plantar neurovascular damage secondary to TTC is poorly reported. Neurovascular structures at risk include the lateral plantar nerve and artery and first branch of the lateral plantar nerve. Curved TTC nails with lateral entry points theoretically reduce the risk of injury. The purpose of this study was to assess the incidence of iatrogenic injury to the plantar branches of the tibial nerve and posterior tibial artery and to propose a neurovascular safe-zone regarding entry point of retrograde TTC fusion nails. Methods: Ten below-knee thawed fresh-frozen cadaveric specimens were used in the study. None had gross deformity or malalignment of the hindfoot. Ankle and subtalar joints were not prepared before nail insertion but were maintained in neutral dorsiflexion and 5 degrees of valgus of the hindfoot. Surgical technique followed specific technical steps described for the T2 Ankle Arthrodesis Stryker nail (Schonkirchen, Germany), measuring 11 mm diameter and 200 mm long. Shortest distance between the nail and the main plantar neurovascular branches and injured structures were recorded during dissection. We also evaluated the relative position of these branches as they crossed two different lines: a longitudinal line connecting the most posterior point of the plantar surface of the calcaneus (Point A) to the base of the first metatarsal (Point B) and a transverse line connecting point B to the base of the fifth metatarsal (Point C). Results: Shortest distance between the nail and main branches of the plantar neurovascular bundle: medial plantar nerve 21.5 mm (17.7-25.2), lateral plantar nerve 4.7 mm (2.2-7.1), Baxter’s nerve 6.6 mm (2.1-11) and lateral plantar artery 1 mm (0-2.7). Lateral plantar artery was found to be in direct contact with the nail 70% of the time, 30% with a macroscopic laceration. Baxter’s nerve and lateral plantar nerve were injured in 20% of the cadavers. The medial plantar artery and nerve were not injured. Position of the structures in AB line, from proximal to distal: Baxter’s nerve (33.5%), lateral plantar artery (39%), nail (42%), lateral plantar nerve (47%) and medial plantar nerve (63%). Distance from point B in the line BC was respectively 26% and 56% for medial and lateral plantar nerves. Conclusion: Our cadaveric anatomical study shows that the most common structures at risk for iatrogenic injury by lateral curved retrograde TTC fusion nails are the lateral plantar artery, lateral plantar nerve and Baxter’s nerve. The proposition of a true neurovascular “safe-zone” is difficult to ascertain given individual anatomic variations. More lateral entry points would decrease the risk of iatrogenic injury to these structures. We propose that a longer plantar longitudinal approach (4-5 cm) and blunt dissection performed deeper to the plantar fascia would decrease risk of plantar neurovascular structure injury by the nail.

Curved retrograde TTC fusion nails: Neurovascular structures at risk and entry point safe-zone

Tendoscopy has been proposed in treating several conditions affecting tendons around the ankle. We reviewed literature to investigate the efficacy of Achilles, peroneal and tibialis posterior tendoscopy.Following the PRISMA checklist, the Medline, Scopus and EMBASE databases were searched, including studies reporting patients affected by disorders of Achilles, peroneal and tibialis posterior tendons and treated by tendoscopy (or tendoscopic-assisted procedures). The tendoscopic technique, rehabilitation protocol, clinical scores, patient satisfaction, success and failure rates and complications were evaluated.Sixteen studies (319 procedures) dealt with Achilles tendoscopy, nine (108) and six (78) about peroneal and tibialis posterior, respectively. Wound healing, cosmetic results, complication rate, work and sport resumption delay were satisfactory. Clinical scores, classification methods and rehabilitation protocols adopted were heterogeneous.The recent scientific evidence suggests that tendoscopy and endoscopic-assisted percutaneous procedures are a safe and effective treatment in chronic and acute disorders of tendons around the ankle.

Ankle Arthrodesis with Structural Grafts Can Work for the Salvage of Failed Total Ankle Replacement

Category: Ankle, Ankle Arthritis Introduction/Purpose: Surgical treatment options after failed total ankle replacement (TAR) are limited to revision total ankle replacements, revision bone block interposition arthrodesis, or amputation. In patients where revision TAR is not an option and limb salvage is desired, conversion to an ankle arthrodesis can provide a stable, plantigrade foot. Revision arthrodesis is challenged by significant bone loss with removal of the TAR implant. The purpose of this study was to report midterm outcomes and radiographic results in a single surgeon’s group of patients who have undergone revision ankle arthrodesis with intramedullary nail fixation and structural allograft augmentation following failed TAR. Methods: Institutional review board approval was obtained for this study. A retrospective chart and radiographic review was performed. Patients with a minimum follow-up of 1 year who underwent failed TAR revision with structural femoral head allograft and intramedullary tibiotalocalcaneal (TTC) nail fixation were included. Patients with less than 1-year follow-up and alternative fixation or graft constructs were excluded from the study. Data were collected upon enrollment visit and again at midterm follow-up ranging from 3-7 years post-operatively. Foot Function Index (FFI), American Orthopaedic Foot & Ankle Society (AOFAS) outcomes scores and radiographs were obtained at each visit. Primary outcomes of interest were the rate of limb salvage and patient reported outcome scores. Secondary outcomes include limb length correction and the fate of the structural allograft. Results: Five patients were available for enrollment. Average age at surgery was 63.2 (range 56-69) years. Enrollment visits averaged 1.68 years post-operative (range 0.95 - 3.78). Midterm follow-up was at an average of 5.2 years (range 4.7-5.6). Upon enrollment average FFI was 34.82 (range 8.82-75.88) and at midterm follow-up was 20.42 (range 0-35.38). AOFAS scores upon enrollment averaged 66.6 (range 61-77) and at midterm follow-up averaged 70.33 (range 54-88). Radiographic results show union in 4 of 5 patients at enrollment and in 2 of 3 patients upon midterm follow-up. Average limb length discrepancy at enrollment was 1.4 cm (range 0.5 - 2.0) and 1.6 cm (range 0.2 – 2.4) at midterm follow-up. Conclusion: Conversion of failed TAR to TTC fusion with femoral head allograft is a salvage technique that can lead to a functional arthrodesis and limb salvage in a situation where options are challenging. Our results show continued improvement in patient reported outcomes scores moving from short-term to midterm follow-up with preservation of limb length and no trend towards structural allograft resorption.

Uncontrolled diabetes as a potential risk factor in tibiotalocalcaneal fusion using a retrograde intramedullary nail

BackgroundTibiotalocalcaneal (TTC) fusion using a retrograde intramedullary (IM) nail is an effective salvage option for terminal-stage hindfoot problems. However, as many patients who receive TTC fusion bear unfavorable medical comorbidities, the risk of nonunion, infection and other complications increases. This study was performed to identify the factors influencing outcomes after TTC fusion using a retrograde IM nail. MethodsBetween September 2008 and February 2012, 34 consecutive patients received TTC fusion using a retrograde IM nail for limb salvage. All patients had a minimum follow-up of two years. Throughout follow-up, standard ankle radiography was performed along with clinical outcome assessment using a visual analog scale (VAS) for pain, the American Orthopaedic Foot and Ankle Society Ankle-Hind Foot Scale (AOFAS A/H scale) and the Foot and Ankle Outcome Score (FAOS). For the retrospective analysis, demographic factors, preoperative medical status, laboratory markers, and etiology were comprehensively reviewed using medical records. The success of the index operation was determined using clinical and radiological outcomes. Finally, the effect of each factor on failure after the operation was analyzed using univariate logistic regression. ResultsIn a mean of seven months, 82% (28/34) achieved union, as evaluated by standard radiography. All clinical outcome parameters improved significantly after the operation, including VAS, AOFAS A/H scale, and FAOS (P<0.001). At the last follow-up, five cases of nonunion with less than AOFAS A/H scale of 80 and two cases of below knee amputation due to uncontrolled infection were determined to be failures. None of the factors (etiology, demographics, laboratory markers and medical status) significantly influenced failures. However, uncontrolled DM significantly increased the failure rate with an odds ratio of 10 (P=0.029). ConclusionsTTC fusion with a retrograde intramedullary nail is a successful treatment for complicated hindfoot problems such as traumatic osteoarthritis, Charcot arthropathy and failed TAA. However, it should be used judiciously in patients with uncontrolled DM, as the risk of failure increases. DesignRetrospective cohort study.

Neurovascular Structures at Risk With Curved Retrograde TTC Fusion Nails.

The purpose of this study was to assess the risk of iatrogenic injury to plantar neurovascular structures of the foot during insertion of a curved retrograde tibiotalocalcaneal (TTC) fusion nail. Ten below-knee thawed fresh-frozen cadaveric specimens underwent curved retrograde nailing of the ankle. The shortest distance between the nail and the main plantar neurovascular branches and injured structures were recorded during dissection. We also evaluated the relative position of these structures along 2 lines (AB, connecting the calcaneus to the first metatarsal, and BC, connecting the first and fifth metatarsal). The lateral plantar artery was found to be in direct contact with the nail 70% of the time, with a macroscopic laceration 30% of the time. The Baxter nerve was injured 20% of the time, as was the lateral plantar nerve. The medial plantar artery and nerve were never injured. The most proximal structure to cross line AB was the Baxter nerve followed by the lateral plantar artery, the nail, the lateral plantar nerve, and the medial plantar nerve. Our cadaveric anatomic study found that the most common structures at risk for iatrogenic injury by lateral curved retrograde TTC fusion nails were the lateral plantar artery and nerve, and the Baxter nerve. Determination of a true neurovascular safe zone is challenging and therefore warrants careful operative dissection to minimize neurovascular injuries.

Retrospective Case Study of TTC Fusion Treated with Carbon Fiber Nail

Category: Ankle Introduction/Purpose: Tibiotalocalcaneal arthrodesis is a salvage option reserved for severe ankle and hindfoot deformities, arthritis of the ankle and subtalar joints, avascular necrosis of the talus, failed total ankle arthroplasty, and Charcot arthropathy. Implants have long been made from various metals most commonly stainless steel or titanium alloys. Disadvantages of metal implants include limited fatigue life, mismatch of modulus of elasticity, potential for wear debris, corrosion, and radiodensity that can preclude accurate radiographic visualization. Carbon fiber implants have been available for years. The advantageous properties of carbon fiber for use as orthopaedic implants include a similar modulus of elasticity to bone to decrease stress shielding, biocompatilibity, with minimal cellular response when studied invitro and invivo, ability to withstand prolonged fatigue straining and radiolucency on XR. Methods: A Carbofix TM carbon fiber TTC fusion nail was used in 15 patients with for Tibiotalocalcaneal /TC fusion. All patients received preop, intra op xrays, and follow up xrays at weeks 2/6/12. After 12 weeks xrays were taken every 3 months until 1 year. All xrays were read by a radiology attending to assess for consolidation and maintenance of alignment. We also performed CT scan for the nonunion [clinical &amp; Radiological] Results: We were able to find comparable results [patients operated with carbon fiber nail] to the historical data of the patients treated with different metal implants. We were also able to check the safety of using the implant [no tissue reaction or reactivity], easily able to see the fusion across the joints secondary to radioluceny and artifact free CT scan or MRI when required. There were no metal related complications noted. Conclusion: These studies have shown the usefulness of carbon fiber implants but there are no studies which explicitly review Tibiotalocalcaneal/Tibiocalcaneal fusion. We present a retrospective case series of 15 patients who were treated with carbon fiber tibiotalocalcaneal fusion nail.

Total Ankle Replacement and Simultaneous Subtalar Arthrodesis

Category: Ankle Arthritis Introduction/Purpose: Patients with arthritis or severe malfunctions involving both the ankle and the subtalar joints can benefit tibiotalocalcaneal (TTC) arthrodesis or total ankle replacement and subtalar fusion. Actually, TTC fusion is considered as a salvage option resulting in a completely stiff ankle and hindfoot, considerably limiting global foot function. With the evolution of prosthetic design and surgical 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 includes 25 patients who underwent primary TAR and simultaneous subtalar fusion from May 2011 to November 2014. Sixteen males (64%) and 9 females (36%) were enroled with a mean age of 58 years (25-82). Patients were clinically assessed preoperatively and at 6 and 12 months postoperatively. Radiographic examination included a postoperative CT scan obtained 12 months after surgery. 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 Orthopedic Foot &amp; Ankle Society ankle/hindfoot score from 27.9 to 75.1. Range of motion significantly increased from 12 to 32.8 degrees. In addition, there was a statistically significant decrease in visual analog scale (VAS) pain score from 8.6 to 2.1. Conclusion: TAR and simultaneous subtalar joint fusion are reliable procedures for the treatment of ankle and subtalar joint arthritis. Furthermore, CT scans showed an excellent reliability among orthopaedic surgeons in determining the degree of successful fusion of subtalar arthrodesis.

Secondary Procedures in Third Generation Total Ankle Arthroplasties

Category: Ankle Arthritis Introduction/Purpose: As surgeons have become more comfortable with performing more complex total ankle replacements (TAR) with larger amounts of deformity, it is unclear whether or not to address additional pathology at the time of surgery. Currently, we address all foot and ankle pathology at time of the index arthroplasty. It is unclear however, how often and for what reasons secondary surgery is performed after TAR. We hypothesize that there were no differences in the type or rate of secondary surgeries performed. Methods: We identified a consecutive series of 761 primary TARs performed between January 1998 and December 2014. We identified patients who required a secondary surgery to treat foot and ankle pathology following a STAR, INBONE I/II, or Salto- Talaris. We then analyzed if there were differences between the implants in terms of time to secondary surgery or types of procedures performed. Results: 193 patients (25.3%) required a secondary procedure with an average time to a secondary procedure of 24.5 months. The rate of second surgery in both the Salto (25/113, HR=0.64 with 95%CI=0.408-0.996; p=0.048) and STAR (81/333, HR=0.694 with 95%CI=0.507-0.949; p=0.022) is less when compared to the INBONE group (87/315). The STAR had a significantly longer time to secondary procedure (33.8 months) versus a Salto-Talaris (12.8 months) or an INBONE (19.2 months, p=001). The number of secondary procedures (p&lt; .001), polyethylene exchanges (p&lt; .001), cyst grafting (p=.036) were similar in INBONE and STAR, but significantly more than the Salto. The INBONE prosthesis had a significantly higher talar component failure rate (p=.038), but similar rate of subtalar, ankle, and TTC fusion. Conclusion: Knowledge of the rates and types of secondary surgeries is useful information on the natural history of third generation ankle implants. While there are differences in the rate of failure or revisions between implants, no implant has proven superior to one another.