Porous tantalum as a structural graft in foot and ankle surgery

Clinical, Radiographic, and Patient-Reported Outcomes of First Metatarsophalangeal Interposition Arthrodesis Using Porous Titanium Wedges

BACKGROUND

First metatarsophalangeal (MTP) arthrodesis is a common surgical procedure for addressing hallux MTP pathology. In the setting of revision procedures with significant bone loss, porous titanium wedges may provide an alternative to structural bone autograft or allograft.

OBJECTIVE

The purpose of this study is to report the clinical and radiographic outcomes achieved in first MTP interposition arthrodesis using porous titanium wedges.

METHODS

A retrospective analysis of 9 patients with a mean age 65.4 years (45-82 years) who underwent first MTP interposition arthrodesis with the use of porous titanium wedges from February 2014 to September 2017 was performed. Outcomes were assessed using both plain-film radiographs and computed tomography (CT) scans, as well as patient-reported outcome measures, including Foot and Ankle Ability Measure (FAAM) (Sports and Activities of Daily Living), pain Visual Analogue Scale (VAS), and 36-Item Short Form Survey (SF-36). Average follow-up time was 34.2 months (14-72 months).

RESULTS

At final follow-up, the average FAAM score was 91.1 ± 14.7 (75.1 ± 5.3 FAAM Activities of Daily Living; 17.9 ± 9.9 FAAM Sports). Average pain VAS score was 1.9 ± 1.7. Postoperative computed tomography (CT) imaging was obtained for 5 patients, all of which demonstrated good bony apposition or osseous integration of the wedge. Four patients underwent subsequent surgical procedures, including 3 isolated dorsal fixation revisions, and 1 complete MTP arthrodesis revision.

CONCLUSION

To our knowledge, this study represents the first reported clinical and radiographic outcomes in patients undergoing first MTP interposition arthrodesis with use of porous titanium wedges. While we found this technique to be a viable alternative to bone grafting for this difficult problem, further research should focus on comparative data with other commonly performed operative techniques.

LEVEL OF EVIDENCE

Level IV: Case series.

Republication of "Preliminary Experience Using Bioactive Glass Wedges for Cotton Osteotomy"

Background

Medial cuneiform dorsal opening wedge (Cotton) osteotomy is often used for treating forefoot varus in patients undergoing surgery for stage II posterior tibialis tendon dysfunction. The goal of this study was to examine the radiographic outcomes of Cotton osteotomy with bioactive glass wedge to assess for both maintenance of correction and clinical results and complications. We hypothesized that bioactive glass wedges would maintain correction of the osteotomy with low complication rates.

Methods

Between December 2015 and June 2016, the charts of 17 patients (10 female and 7 male) who underwent Cotton osteotomy using bioactive glass wedges were retrospectively reviewed. Patient age averaged 56.8 years (range, 16-84). The average follow-up was 6.5 months. Radiographs were reviewed to assess for initial correction and maintenance of correction of medial column sag as well as for union. Charts were reviewed for complications.

Results

The medial column sag correction averaged 15.6% on the final postoperative lateral radiograph. Meary angle averaged 19 degrees (3.14-42.8 degrees) preoperatively and 5.5 degrees (0.4-20.7 degrees) at final follow-up. All patients achieved clinical and radiographic union. One patient developed neuropathic midfoot pain and was managed with sympathetic blocks. One patient had a delayed union that healed at 6 months without surgical intervention. No patients required the use of custom orthotics or subsequent surgical procedures.

Conclusion

Cotton osteotomy with bioactive glass wedges produced consistent correction of the medial column with low risk.

Level of Evidence

Level IV, case series.

Radiographic Outcomes of Titanium Augment vs Bone Graft in Lateral Column Lengthening for Adult-Acquired Flatfoot Deformity

Background

Lateral column lengthening (LCL) is a surgical procedure used to manage forefoot abduction and, in theory, also increases the longitudinal arch by plantarflexion of the first ray through tensioning the peroneus longus for patients with stage IIB adult acquired flatfoot deformity (AAFD). This procedure utilizes an opening wedge osteotomy of the calcaneus, which is then filled with autograft, allograft, or a porous metal wedge. The primary aim of this study was to compare the radiographic outcomes of these different bone substitutes following LCL for stage IIB AAFD.

Methods

We conducted a retrospective review of all patients who underwent LCL from October 2008 until October 2018. Preoperative weightbearing radiographs, initial postoperative radiographs, and 1-year weightbearing radiographs were reviewed. The following radiographic measurements were recorded: incongruency angle, talonavicular coverage angle (TNCA), talar-first metatarsal angle (T-1MT), and calcaneal pitch.

Results

A total of 44 patients were included in our study. The mean age of the cohort was 54 (range, 18-74). The study cohort was divided into 2 groups. There were 17 (38.7%) patients who received a titanium metal wedge and 27 (61.5%) that received autograft or allograft. Patients that underwent LCL with the autograft/allograft group were significantly older (59 vs 47 years old, P = .006). Patients who underwent LCL with a titanium wedge had a significantly higher preoperative talonavicular angle (32 vs 27 degrees, P = .013). There were no significant differences in postoperative TNCA, incongruency angle, or calcaneal pitch at 6 months or 1 year.

Conclusion

At 6 months and 1 year, no radiographic differences were found between autograft/allograft bone substitutes vs titanium wedge in LCL.

Level of Evidence

Level III, retrospective cohort study.

Transfibular total ankle arthroplasty : a new reliable procedure at five-year follow-up

AIMS

This study reports updates the previously published two-year clinical, functional, and radiological results of a group of patients who underwent transfibular total ankle arthroplasty (TAA), with follow-up extended to a minimum of five years.

METHODS

We prospectively evaluated 89 patients who underwent transfibular TAA for end-stage osteoarthritis. Patients' clinical and radiological examinations were collected pre- and postoperatively at six months and then annually for up to five years of follow-up. Three patients were lost at the final follow-up with a total of 86 patients at the final follow-up.

RESULTS

A total of 86 patients were evaluated at a mean follow-up of 65.4 months (60 to 90). At five-year follow-up, statistically significant improvements (p < 0.001) were found in the mean American Orthopaedic Foot & Ankle Society Ankle Hindfoot Score (from 33.8 (SD 14.3) to 86.1 (SD 8.8)), visual analogue scale for pain (from 8.5 (SD 1.7) to 1.5 (SD 1.2)), Short Form-12 Physical and Mental Component Scores (from 29.9 (SD 6.7) and 43.3 (SD 8.6) to 47.3 (SD 7.5) and 52.2 (SD 8.0), respectively), and mean ankle dorsiflexion and plantarflexion (from 6.2° (SD 5.5°) and 9.6° (SD 5.8°) to 23.9° (SD 7.7°) and 16.9° (SD 7.2°), respectively). Radiologically, the implants maintained neutral alignment without subsidence. Tibial or talar radiolucency was found in eight patients, but none of these patients was symptomatic. At five-year follow up, 97.7% of implants (95% confidence interval 91.2 to 99.4) were free from revision or removal with 84 implants at risk. We recorded two cases (2.3%) of failure for septic loosening.

CONCLUSION

Transfibular TAA is safe and effective with a high survival rate at mid-term follow-up and satisfactory clinical and radiological results. Further studies are required to determine the long-term performance of these implants. Cite this article: Bone Joint J 2022;104-B(4):472-478.

I am Afraid of Lateral Column Lengthening. Should I Be?

Lateral column lengthening has long been used in conjunction with other soft tissue and bony procedures to correct the midforefoot abduction seen in class B progressive collapsing foot deformity. The effectiveness of this osteotomy to restore the physiologic shape of the foot has been used by foot and ankle surgeons around the world to provide functional improvement for patients suffering from this disease. The overall low complication rates, low nonunion rates, and improved radiographic and functional outcomes provided by lateral column lengthening make this a valuable option for the treatment of class B progressive collapsing foot deformity.

Use of Three-dimensional Titanium Trusses for Arthrodesis Procedures in Foot and Ankle Surgery: A Retrospective Case Series

Periarticular osseous defects pose a challenge when considering arthrodesis. Failure to restore the cubic content of bone can result in shortening and malalignment, as well as subsequent biomechanical issues. This study reports on 12 patients treated with patient-specific 3-D printed (7) and prefabricated titanium trusses (5). Twelve consecutive patients were treated for osseous defects of the forefoot, hindfoot, and ankle with patient-specific, 3D printed or prefabricated manufacturer titanium trusses. Seven were customized, patient-specific 3D printed trusses (4WEB, Frisco, Texas) and 5 were prefabricated manufacturer titanium trusses. All patients had a minimum of 6 months of clinical and radiographic follow-up. and no patients were lost to follow-up. Seven of the 12 patients had a computed tomography (CT) scan performed following surgery. Successful limb or ray salvage was achieved in 11 of 12 patients (91.7%). Six of 7 patients (85.7%) with a postoperative CT scan, went on to complete radiographic consolidation across all arthrodesis sites. The remaining 5 patients showed complete consolidation across the arthrodesis sites on plain film radiographs. Complications included one patient with a residual midfoot deformity that required a subsequent midfoot osteotomy in order to obtain a plantigrade foot following successful tibiotalocalcaneal (TTC) arthrodesis, and a below knee amputation in one patient who underwent revision TTC arthrodesis to salvage avascular necrosis of the talus that developed following the index procedure. Eleven of 12 patients undergoing arthrodesis demonstrated successful union with both customized, patient-specific 3D printed and prefabricated manufacturer titanium trusses on CT scans or radiographs. The average follow-up was 14 months. Reports on traditional methods of addressing periarticular defects in patients requiring arthrodesis show mixed results and relatively high complication rates. Custom, 3D printed and prefabricated titanium truss technology offers an alternative to traditional methods for large, periarticular osseous defects.

The Clinical Application of Porous Tantalum and Its New Development for Bone Tissue Engineering

Porous tantalum (Ta) is a promising biomaterial and has been applied in orthopedics and dentistry for nearly two decades. The high porosity and interconnected pore structure of porous Ta promise fine bone ingrowth and new bone formation within the inner space, which further guarantee rapid osteointegration and bone-implant stability in the long term. Porous Ta has high wettability and surface energy that can facilitate adherence, proliferation and mineralization of osteoblasts. Meanwhile, the low elastic modulus and high friction coefficient of porous Ta allow it to effectively avoid the stress shield effect, minimize marginal bone loss and ensure primary stability. Accordingly, the satisfactory clinical application of porous Ta-based implants or prostheses is mainly derived from its excellent biological and mechanical properties. With the advent of additive manufacturing, personalized porous Ta-based implants or prostheses have shown their clinical value in the treatment of individual patients who need specially designed implants or prosthesis. In addition, many modification methods have been introduced to enhance the bioactivity and antibacterial property of porous Ta with promising in vitro and in vivo research results. In any case, choosing suitable patients is of great importance to guarantee surgical success after porous Ta insertion.

Outcomes of Tibiocalcaneal Arthrodesis in High-Risk Patients: An Institutional Cohort of 18 Patients

INTRODUCTION

Tibiocalcaneal (TC) arthrodesis is commonly performed in patients with severe hindfoot disease. These include severe Charcot deformities, ankle malformations, chronic osteomyelitis (COM), and avascular necrosis (AVN). The talar vascular becomes disrupted to the point that the bone can no longer be salvaged. The procedure involves performing a talectomy and fusing the tibia to the calcaneus. This helps in preserving the remaining hindfoot anatomy, while allowing the patient to regain function and mobility. Our study highlights certain risk factors that influence the rate of postoperative complication after tibiocalcaneal surgery.

MATERIALS AND METHODS

We retrospectively reviewed the charts of 18 patients from a single institution who underwent tibiocalcaneal between the years of 2011 and 2019. Preoperative diagnoses, comorbidities, and post-operative outcomes were noted among all patients. Then, the rates of non-union, below-knee amputations, revision surgeries, postoperative infections, and hardware failure were recorded. These data were then analyzed to determine which preoperative and perioperative factors affected postoperative outcomes for patients after tibiocalcaneal arthrodesis surgery.

RESULTS

Nonunion was the most commonly reported complication in this series. Eight of the eighteen patients were documented to have nonunion including three patients with stable pseudarthrosis. Diabetic patients had a slightly higher incidence of nonunion (4 of 7 patients) compared to those without diabetes (4 of 11 patients). Of the nine patients diagnosed with Charcot arthropathy, five had nonunion. Three of the five individuals with a BMI ranging from 25 to 30, and four of the six individuals with a BMI of greater than 30 had a nonunion. Infection was a post-operative complication for four of the eighteen patients. Two of the four patients had multiple comorbidities in addition to chronic infections in the joint which were recurrent after surgery.

CONCLUSION

In conclusion, TC arthrodesis provides a viable option for high-risk patients with complicated ankle pathology who have not had successful outcomes from previous treatment. It is not without complications considering the comorbidities the patients present with before requiring this procedure. Further studies are necessary to validate the trends of outcomes and comorbidities of patients with TC arthrodesis.

Distal tibial distraction osteogenesis-an alternative approach to addressing limb length discrepancy with concurrent hindfoot and ankle reconstruction

Background

Limb length discrepancy (LLD) in the setting of concurrent hindfoot and ankle deformity poses an added level of complexity to the reconstructive surgeon. Regardless of etiology, a clinically significant LLD poses additional challenges without a forthright and validated solution. The purpose of the current study is to determine whether reconstructive hindfoot and ankle surgery with concurrent lengthening through a distal tibial corticotomy is comparable to other treatment alternatives in the literature.

Patients and methods

A retrospective review of hindfoot and ankle deformity correction utilizing Ilizarov circular external fixation with concurrent distal tibial distraction osteogenesis from July 2009 to September 2014 was conducted.

Results

This study included 19 patients with a mean age of 47.47 ± 13.36 years with a mean follow up of 576.13 ± 341.89 days. The mean preoperative LLD was 2.70 ± 1.22 cm and the mean operatively induced LLD was 2.53 ± 0.59 cm. The mean latency period was 9.33 ± 3.47 days and distraction rate was 0.55 ± 0.16 mm/day. The mean distraction length was 2.14 ± 0.83 cm and mean duration of external fixation was 146.42 ± 58.69 days. The time to union of all hindfoot and ankle fusions was 121.00 ± 25.66 days with an overall fusion rate of 85.71%.

Conclusions

The successful treatment of hindfoot and ankle deformity correction in the setting of LLD using the technique of a distal tibial corticotomy and distraction osteogenesis is reported and illustrates an additional treatment technique with comparable measured outcomes to those previously described. We urge that each patient presentation be evaluated with consideration of all described approaches and associated literature to determine the current best reconstructive approach as future studies may validate or replace the accepted options at present.

Complications and Early Radiographic Outcomes of Flatfoot Deformity Correction With Metallic Midfoot Opening Wedge Implants

Background:

Forefoot varus is a common component of flatfoot deformity that is often surgically addressed. Multiple options exist to plantarflex the medial column, with midfoot fusion and the Cotton osteotomy being the most common. This study analyzes radiographic outcomes and complications when a titanium wedge is used for structural support in a dorsal opening wedge Cotton osteotomy of the medial cuneiform.

Methods:

Between December 2016 and May 2018, 32 feet in 31 patients were treated with medial column titanium wedges for residual forefoot varus in association with flatfoot corrections. All participants had preoperative and weight-bearing postoperative radiographs examined for analysis of radiographic correction. The average age of the patients was 41.1 (range: 12-70). The average follow-up time for patients was 12.2 months (8-24).

Results:

All radiographic parameters were statistically significantly improved from preoperative to postoperative (P < .05). There were no instances of nonunion of the medial cuneiform osteotomy. There was 1 implant that loosened and was revised to a larger implant that healed uneventfully. No wedges were removed for continued pain at the osteotomy site.

Conclusion:

This study suggests that metal wedges are both safe and effective for use in medial column correction based on early follow-up data. Future studies comparing titanium wedges versus traditional bone grafting for Cotton osteotomies may provide further analysis of radiographic correction, operative time, procedure cost, and outcomes. There were no instances of pain over the titanium wedge site. Radiographic outcomes are similar to those reported for opening wedge Cotton osteotomies including bone grafting and wedge plates with screws. Future studies will help determine the long-term maintenance of correction and hardware survivorship.

Level of Evidence:

Level IV, case series.

Subtalar Joint Distraction Arthrodesis Utilizing a Titanium Truss: A Case Series

Subtalar joint distraction arthrodesis has been recommended for the treatment of conditions such as nonunion or malunion of subtalar joint arthrodesis posttraumatic arthritis. Both conditions are difficult to treat, because the deformities created in the frontal and sagittal planes of these conditions are complex. If these malalignments are not addressed, ankle joint instability and wear occur over time. In general, either autograft or allograft bone has been used to perform distraction arthrodesis of the subtalar joint. Although studies have shown successful use, there have been complications. Autografts have resulted in donor site morbidity and limitations on graft size, and allografts have shown high nonunion rates. Both autografts and allografts have shown graft collapse over time. Recent literature has discussed the use of tantalum technology to span large defects in bone healing. Studies have shown that tantalum provides superior strength and bone incorporation compared with autografts and allografts. This case series presents 2 cases in which tantalum truss technology was used for distraction arthrodesis. Although this series is limited in patient numbers, both cases show effective graft incorporation with no loss in height over time and earlier return to activity compared with previous studies that used autograft and allograft wedges.

Severe Flexible Pes Planovalgus Deformity Correction Using Trabecular Metallic Wedges

BACKGROUND:

Lateral column lengthening and plantarflexion dorsal opening wedge osteotomy of the medial cuneiform are 2 commonly used procedures to address the deformity seen in severe flexible pes planovalgus deformity. Traditionally, iliac crest allograft or autograft has been used to fill the osteotomy sites. Porous metallic wedges can be used as an alternative to avoid the concerns associated with both autograft and allograft.

METHODS:

We performed a retrospective review of patients who had corrective osteotomies utilizing metallic wedges to address flexible pes planovalgus with at least 2 years of follow-up data. Preoperative radiographic measurements (anteroposterior [AP] and talo-first metatarsal angle, calcaneal pitch, talocalcaneal angle, and talonavicular uncoverage angle) and functional scores (visual analog scale [VAS] pain, Foot and Ankle Ability Measure [FAAM] Activities of Daily Living [ADL], FAAM Sports) were compared to postoperative radiographic measurements and functional scores.

RESULTS:

There were statistically significant improvements in all radiographic parameters and functional scores. Two nonunions were seen, one of which healed with revision surgery while the other was asymptomatic. At the time of last radiographic follow-up, there were no recurrences of deformity or collapse.

CONCLUSION:

Porous metallic wedges offer an attractive alternative to autograft and/or allograft in the setting of corrective osteotomies for severe flexible pes planovalgus. Patients who underwent corrective osteotomies using these wedges demonstrated reliable, effective, and stable radiographic correction as well as significant improvements in function and pain.

LEVEL OF EVIDENCE:

Level IV, case series.

Long-Term Outcomes of Corrective Osteotomies Using Porous Titanium Wedges for Flexible Flatfoot Deformity Correction

Common corrective osteotomies used in flexible flatfoot deformity reconstruction include Cotton and Evans osteotomies, which require structural graft to maintain correction. Auto-, allo-, and xenografts are associated with a number of limitations, including disease transmission, rejection, donor site morbidity, technical challenges related to graft fashioning, and graft resorption. Porous titanium is a synthetic substance designed to address these flaws; however, few studies have been reported on the efficacy, safety, and long-term outcomes. A multicenter retrospective cohort of 63 consecutive preconfigured porous titanium wedges (PTWs) used in flexible flatfoot reconstructions from June 1, 2009 to June 30, 2015 was evaluated. The primary outcome measure was the pre- to postdeformity correction efficacy. The secondary outcomes included maintenance of correction at a minimum follow-up point of 12 months, complications, graft incorporation, and graft safety profile. Multivariate linear regression found a statistically significant improvement in all radiographic parameters from preoperatively to the final weightbearing radiographs (calcaneocuboid 18.850 ± 4.020 SE, p < .0001; Kite's, 7.810 ± 3.660 SE, p = .04; Meary's 13.910 ± 3.100 SE, p = .0001; calcaneal inclination, 5.550 ± 2.140 SE, p = .015). When restricted to patients with >4 years of follow-up data, maintenance of correction appeared robust in all 4 measurements, demonstrating a lack of bone or graft resorption. No patients were lost to follow-up, no major complications or implant explantation or migration occurred, and all implants were incorporated. Minor complications included hardware pain from plates over grafts (8%), 1 case of scar neuritis, and a 5% table incidence of transfer pain associated with the PTWs. These results support the use of PTWs for safety and degree and maintenance of correction in flatfoot reconstruction.

The Use of Tantalum Metal in Foot and Ankle Surgery

There are several reconstructive procedures in foot and ankle surgery wherein structural grafts are needed to fill defects, restore height, and maintain correction while providing an osteoconductive environment until fusion occurs. Traditionally used autografts and allografts have their disadvantages and limitations. Porous tantalum, with stiffness similar to bone and its biocompatibility, can be a viable option in foot and ankle reconstructive procedures.

Titanium Scaffolding: An Innovative Modality for Salvage of Failed First Ray Procedures

Shortening of the first ray is a potential complication associated with first metatarsal procedures. Correction of this deformity conventionally has required the use of a tricortical bone graft to lengthen the bone. Graft complications, including donor site morbidity, poor graft stability, and graft resorption, have revealed a need for an alternative procedure. The present report shows that titanium cage scaffolding has lower extremity applications beyond its previous uses in the ankle and spine. Two patients underwent surgical correction for failed first ray procedures using a titanium cage apparatus with a calcaneal autograft and other biologic agents. The scaffolds were appropriately sized to fill the defect. Patients remained non-weightbearing until radiographic evidence of healing appeared. Success was determined by diminished pain, a return to activity, ambulation, and patient satisfaction. Patients exhibited faster-than-anticipated healing, including a return to protected weightbearing activities and increased stability within 6 weeks. Titanium cage implants provide long-term stability and resistance to stress and strain in the forefoot. The implant we have described, newly applied to the first ray, is analogous to a system used in salvage of failed ankle replacements. In addition to reducing reliance on the iliac crest bone graft, the titanium cage apparatus is advantageous because it is customized to fill a defect using computed tomography scanning, thereby reducing graft failure secondary to an improper shape. These cases demonstrate the potential beneficial applications for titanium cages in failed first ray reconstruction.

Preliminary Experience Using Bioactive Glass Wedges for Cotton Osteotomy

Background:

Medial cuneiform dorsal opening wedge (Cotton) osteotomy is often used for treating forefoot varus in patients undergoing surgery for stage II posterior tibialis tendon dysfunction. The goal of this study was to examine the radiographic outcomes of Cotton osteotomy with bioactive glass wedge to assess for both maintenance of correction and clinical results and complications. We hypothesized that bioactive glass wedges would maintain correction of the osteotomy with low complication rates.

Methods:

Between December 2015 and June 2016, the charts of 17 patients (10 female and 7 male) who underwent Cotton osteotomy using bioactive glass wedges were retrospectively reviewed. Patient age averaged 56.8 years (range, 16-84). The average follow-up was 6.5 months. Radiographs were reviewed to assess for initial correction and maintenance of correction of medial column sag as well as for union. Charts were reviewed for complications.

Results:

The medial column sag correction averaged 15.6% on the final postoperative lateral radiograph. Meary angle averaged 19 degrees (3.14-42.8 degrees) preoperatively and 5.5 degrees (0.4-20.7 degrees) at final follow-up. All patients achieved clinical and radiographic union. One patient developed neuropathic midfoot pain and was managed with sympathetic blocks. One patient had a delayed union that healed at 6 months without surgical intervention. No patients required the use of custom orthotics or subsequent surgical procedures.

Conclusion:

Cotton osteotomy with bioactive glass wedges produced consistent correction of the medial column with low risk.

Level of Evidence:

Level IV, case series.

Large Osseous Defect Reconstruction Using a Custom Three-Dimensional Printed Titanium Truss Implant

Treatment of large osseous defects remains a difficult surgical challenge. Autografts and allografts have been known to undergo late collapse, because these options are not specifically designed to withstand the high loads of the foot and ankle. The inability to achieve the correct shape for reconstruction further limits their application. Large osseous defects will result during salvage after failed Lapidus bunionectomy, explantation of failed total ankle replacements, and nonunion of Evans calcaneal osteotomy. Each of 3 patients received a 4WEB custom 3-dimensional (3D) titanium truss implant (Patient Specific Custom Implant; 4WEB Medical, Inc., Frisco, TX) for reconstruction. The mean follow-up period was 17.33 ± 3.51 months. Significant improvement was seen in pain, with a successful return to activities of daily living. The 12-month postoperative computed tomography findings demonstrated incorporation of the implant to the surrounding cortical and cancellous bone. No signs of delayed complications, such as stress shielding or implant failure, were found. This is the first case series to describe the use of a custom 3D-printed titanium truss implant to successfully contribute to reconstruction in the setting of failed elective foot and ankle surgery. This technology might play an important role in limb salvage of osseous defects that would otherwise require bone block arthrodesis with structural allograft or autograft bone.

Porous Titanium Wedges in Lateral Column Lengthening for Adult-Acquired Flatfoot Deformity

Lateral column lengthening (LCL) is a common procedure for reconstruction of stage II flexible adult-acquired flatfoot deformity (AAFD). The recent development of porous titanium wedges for this procedure provides an alternative to allograft and autograft. The purpose of this study was to report radiographic and clinical outcomes achieved with porous titanium wedges in LCL. A retrospective analysis of 34 feet in 30 patients with AAFD that received porous titanium wedges for LCL from January 2011 to October 2014. Deformity correction was assessed using both radiographic and clinical parameters. Radiographic correction was assessed using the lateral talo-first metatarsal angle, the talonavicular uncoverage percentage, and the first metatarsocuneiform height. The hindfoot valgus angle was measured. Patients were followed from a minimum of 6 months up to 4 years (mean 16.1 months). Postoperative radiographs demonstrated significant correction in all 3 radiographic criteria and the hindfoot valgus angle. We had no cases of nonunion, no wedge migration, and no wedges have been removed to date. The most common complication was calcaneocuboid joint pain (14.7%). Porous titanium wedges in LCL can achieve good radiographic and clinical correction of AAFD with a low rate of nonunion and other complications.

LEVELS OF EVIDENCE

Level IV: Case series.

First Metatarsal-Phalangeal Joint Arthrodesis: Primary, Revision, and Salvage of Complications

Arthrodesis of the first metatarsal-phalangeal joint has been proposed for treatment of severe hallux valgus, end-stage hallux rigidus, rheumatoid arthritis, and revision of failed surgery due to the perceived safety and efficacy. This article discusses the principles of first metatarsal-phalangeal joint arthrodesis in primary and revision situations, joint preparation, configurations of osteosynthesis, and common complications, including salvage of nonunion and revision of malunion with realignment osteotomy.

Technique for Use of Trabecular Metal Spacers in Tibiotalocalcaneal Arthrodesis With Large Bony Defects

There are many causes of large bone defects in the tibiotalar joint that need to be definitively treated with a tibiotalocalcaneal (TTC) arthrodesis. Some of the challenges of a large defect are its effect on leg length and the complications associated with trying to fill the defect with structural bone graft. We present an operative strategy involving the use of a trabecular metal implant, a TTC nail that utilized 2 forms of compression, and Reamer/Irrigator/Aspirator (RIA) autograft, to address limitations of previous operative approaches and reliably treat this operative challenge.

Varus Deformity of the Distal Tibia From Physeal Growth Arrest Treated Using a Titanium Metal Porous Wedge

During a cheerleading event, a 14-year-old female sustained a right ankle physeal fracture that was treated nonoperatively with casting. She developed a distal medial tibial physeal arrest, and as the onset of menses was at age 16, she subsequently developed a varus distal tibial deformity. At the age of 19, she was no longer able to participate in collegiate cheerleading due to lateral ankle pain, ankle instability, and peroneal subluxation. After failing conservative treatment, she underwent an ankle arthroscopy, Broström-Gould procedure, peroneal retinacular repair with peroneal tenolysis, and a distal tibial medial opening wedge osteotomy using a porous titanium metal wedge and a one-third tubular plate. At 6-month follow-up, her osteotomy site showed abundant callus formation, and her lateral ankle pain had almost completely resolved. At 22-month follow-up, there were no residual ankle instability or pain complaints, and she had returned to collegiate cheerleading. This case report highlights a very useful, previously not described, application of porous titanium metal wedges for medial supramalleolar opening wedge osteotomies of the tibia. Such wedges are familiar to many foot and ankle orthopaedic surgeons and continue to have expanding indications.

LEVELS OF EVIDENCE

Therapeutic, Level IV: Case report.

Tantalum coating of porous carbon scaffold supplemented with autologous bone marrow stromal stem cells for bone regeneration in vitro and in vivo

Porous tantalum metal with low elastic modulus is similar to cancellous bone. Reticulated vitreous carbon (RVC) can provide three-dimensional pore structure and serves as the ideal scaffold of tantalum coating. In this study, the biocompatibility of domestic porous tantalum was first successfully tested with bone marrow stromal stem cells (BMSCs) in vitro and for bone tissue repair in vivo. We evaluated cytotoxicity of RVC scaffold and tantalum coating using BMSCs. The morphology, adhesion, and proliferation of BMSCs were observed via laser scanning confocal microscope and scanning electron microscopy. In addition, porous tantalum rods with or without autologous BMSCs were implanted on hind legs in dogs, respectively. The osteogenic potential was observed by hard tissue slice examination. At three weeks and six weeks following implantation, new osteoblasts and new bone were observed at the tantalum-host bone interface and pores. At 12 weeks postporous tantalum with autologous BMSCs implantation, regenerated trabecular equivalent to mature bone was found in the pore of tantalum rods. Our results suggested that domestic porous tantalum had excellent biocompatibility and could promote new bone formation in vivo. Meanwhile, the osteogenesis of porous tantalum associated with autologous BMSCs was more excellent than only tantalum implantation. Future clinical studies are warranted to verify the clinical efficacy of combined implantation of this domestic porous tantalum associated with autologous BMSCs implantation and compare their efficacy with conventional autologous bone grafting carrying blood vessel in patients needing bone repairing.

Patient-Specific 3-Dimensional Printed Titanium Truss Cage With Tibiotalocalcaneal Arthrodesis for Salvage of Persistent Distal Tibia Nonunion

Management of large structural defects of the ankle and hindfoot is challenging with modest outcomes in the literature. Tibiotalocalcaneal (TTC) arthrodesis using a retrograde intramedullary nail has been used for the treatment of talar avascular necrosis, severe tibial plafond fractures, ankle and hindfoot nonunions, Charcot arthropathy, and failed total ankle arthroplasty. External fixators and spatial frames provide robust multiplanar correction of deformity, but little is known in the literature regarding the salvage treatment of persistent nonunion refractory to frame treatment. In this report, we present the case of an open tibial plafond fracture with nonunion despite 1 year of fixator and frame management that was successfully treated using a patient-specific 3-dimensional printed titanium truss cage in combination with a retrograde TTC nail. At most recent 1-year follow-up, the patient had minimal pain, no wound complications, and was able to ambulate and work independently without an assistive device for the first time in 2 years since his original injury. The case presented here serves as a proof of principle that requires future research to determine its long-term clinical benefits, cost-effectiveness, and complications.

LEVEL OF EVIDENCE

Level V: Expert Opinion.

Radiographic Outcomes Following Lateral Column Lengthening With a Porous Titanium Wedge

BACKGROUND

Lateral column lengthening (LCL) is commonly utilized in treating stage II posterior tibialis tendon dysfunction. This study aimed to analyze the outcomes of LCL with porous titanium wedges compared to historic controls of iliac crest autograft and allograft. We hypothesized that the use of a porous titanium wedge would have radiographic improvement and union rates similar to those with the use of autograft and allograft in LCL.

METHODS

Between May 2009 and May 2014, 28 feet in 26 patients were treated with LCL using a porous titanium wedge. Of the 26 patients, 9 were males (34.6%). The average age for males was 43 years (range, 17.9-58.7), 48.7 years (range, 21-72.3) for females. Mean follow-up was 14.6 months. Radiographs were examined for correction of the flatfoot deformity and forefoot abduction. All complications were noted.

RESULTS

Radiographically, the patients had a significant deformity correction in the anteroposterior talo-first metatarsal angle, talonavicular coverage angle, lateral talo-first metatarsal angle, and calcaneal pitch. All but 1 patient (96%) had bony incorporation of the porous titanium wedge. The average preoperative visual analog scale pain score was 5; all patients but 3 (12%) had improvements in their pain score, with a mean change of 3.4.

CONCLUSION

LCL with porous titanium had low nonunion rates, improved radiographic correction, and pain relief.

LEVEL OF EVIDENCE

Level IV, case series.

Tibiocalcaneal Arthrodesis With a Porous Tantalum Spacer and Locked Intramedullary Nail for Post-Traumatic Global Avascular Necrosis of the Talus

Global avascular necrosis of the talus is a devastating complication that usually occurs as a result of a post-traumatic or metabolic etiology. When conservative options fail, tibiocalcaneal arthrodesis is generally indicated in conjunction with massive bone grafting to maintain the functional length of the extremity. Several bone grafting options are available, including the use of a freeze-dried or fresh-frozen femoral head allograft or autograft obtained from the iliac crest or fibula, all of which pose their own inherent risks. The noted complications with massive bone grafting techniques have included graft collapse, infection, immune response, donor site morbidity, and nonunion. In an effort to avoid many of these complications, we present a case report involving post-traumatic talar avascular necrosis in a 59-year-old male who was successfully treated with the use of a porous tantalum spacer, an autogenic morselized fibular bone graft, and 30 mL of bone marrow aspirate in conjunction with a retrograde tibiocalcaneal nail. Porous tantalum is an attractive substitute for bone grafting because of its structural integrity, biocompatibility, avoidance of donor site complications, and lack of an immune response. The successful use of porous tantalum has been well-documented in hip and knee surgery. We present a practical surgical approach to tibiotalocalcaneal arthrodesis with a large segmental deficit. To our knowledge, this is the first published report describing an alternative surgical technique to address global avascular necrosis of the talus that could have additional applications in salvaging the ankle with a large bone deficiency.

Salvage of failed total ankle replacement using tantalum trabecular metal: case series

BACKGROUND

Although newer generations of total ankle arthroplasty designs have better clinical outcomes, failure due to aseptic loosening remains a frequent major complication. Arthrodesis is the most common salvage procedure for a failed total ankle replacement. There are several arthrodesis techniques each with its advantages and disadvantages. We present a technique of ankle arthrodesis for failed total ankle replacements using tantalum Trabecular Metal™ (Zimmer, Warsaw, IN) with internal fixation, thus sparing the subtalar joint.

METHODS

Three patients who had undergone arthrodesis for a failed total ankle replacement using tantalum Trabecular Metal were retrospectively reviewed. The mean follow-up period was 57 (range, 31-86) months. The mean age at ankle arthroplasty was 57 (range, 33-72) years and at ankle arthrodesis was 63 (range, 44-74) years. The mean time from arthroplasty to arthrodesis was 7 (range, 2-11) years.

RESULTS

The American Orthopaedic Foot and Ankle Society (AOFAS) score improved from 30.7 (range, 20-39) preoperatively to 72.7 (range, 65-77) postoperatively at the time of last follow-up. Arthrodesis was achieved at a mean of 3 months, and there were no complications.

CONCLUSION

The technique described has several advantages when compared to other methods of salvage ankle arthrodesis. The subtalar joint is not included in the fusion unless it is degenerative and symptomatic. Height of the ankle is maintained throughout the fusion process. Furthermore, Trabecular Metal is abundantly available; it avoids donor site morbidity and eliminates the risk of transmissible diseases.

Ankle salvage surgery with autologous circular pillar fibula augmentation and intramedullary hindfoot nail

Tibiotalocalcaneal arthrodesis with an intramedullary hindfoot nail is an established procedure for fusion of the ankle and subtalar joints. In cases involving ankle bone loss, such as in failed total ankle replacement, it can be difficult to salvage with sufficient bone restoration stability and a physiologic leg length and avoiding below the knee amputation. In addition to the alternatives of using a structural allograft or metal bone substitution, we describe the use of autologous ipsilateral circular pillar fibula augmentation in tibiotalocalcaneal retrograde nail arthrodesis combined with a ventral (anterior) plate in a prospective series of 6 consecutive cases with a mean follow-up duration of 26 ± 9.95 (range 12 to 34) months. The 6 patients (3 female and 3 male), with a mean age of 55 ± 13.89 (range 38 to 73) years were treated with revision surgery of the ankle (1 after talectomy, 5 [83.33%] after failed ankle replacement). The visual analog scale for pain and the American Orthopaedic Foot and Ankle Society hindfoot score were used to assess functional outcome, and radiographs and computed tomography scans were used to determine the presence of fusion. All patients improved clinically from pre- to postoperatively in regard to the mean pain visual analog scale score (from 7.5 to 2.0) and American Orthopaedic Foot and Ankle Society hindfoot score (from 29 to 65 points, of an 86-point maximum for fused joints). Radiologically, no loss in the reduction or misalignment of the hindfoot was detected, and all cases fused solid. One patient (16.67%) required hardware removal. The fixation construct provided good clinical and radiologic outcomes, and we recommend it as an alternative to structural allografts or metallic bone grafts for revision ankle surgery with severe bone loss.

Commercially available trabecular metal ankle interpositional spacer for tibiotalocalcaneal arthrodesis secondary to severe bone loss of the ankle

Retrograde tibiotalocalcaneal nailing arthrodesis has proved to be a viable salvage procedure; however, extended bone loss around the ankle has been associated with high rates of nonunion and considerable shortening of the hindfoot. We present the surgical technique and the first 2 cases in which a trabecular metal™ interpositional spacer, specifically designed for tibiotalocalcaneal nailing arthrodesis, was used. The spacer can be implanted using either an anterior or a lateral approach. An integrated hole in the spacer allows a retrograde nail to be inserted, which provides excellent primary stability of the construct. Trabecular metal™ is a well-established and well-described material used to supplement deficient bone stock in surgery of the spine, hip, and knee. It has shown excellent incorporation and reduces the need for auto- and allografts. The trabecular metal™ interpositional ankle spacer is the first trabecular metal spacer designed specifically for ankle surgery. Its shape and variable size will make it a valuable tool for reconstructing bone loss in tibiotalocalcaneal nailing arthrodesis.

Three-year follow up utilizing tantal cones in revision total knee arthroplasty

There still is no consensus on the treatment of choice in revision knee arthroplasty associated with severe femoral and/or tibial bone loss. A total of 44 patients underwent revision knee arthroplasty procedures using porous tantalum cones (TM cones) to reconstruct tibial and/or femoral bone defects. At latest follow up after 37 months (32-48), 38 patients remained in the study. Tibial and femoral bone loss was categorized according to the AORI-Classification. The average preoperative KSS improved from 34 (range, 6-90) to 63 points (range, 7-90 points). The VAS improved from 7.5 to 4.8. Two patients required a re-revision due to aseptic loosening. There was no correlation between the different types of knee prosthesis implanted. Our study shows favourable clinical and radiological outcomes using TM cones in managing significant bone loss in revision total knee surgery.