Prospective, Multicenter Evaluation of Allogeneic Bone Matrix Containing Viable Osteogenic Cells in Foot and/or Ankle Arthrodesis

Radiographic Fusion Outcomes for Trinity Cellular Based Allograft versus Local Bone in Posterolateral Lumbar Fusion

INTRODUCTION

Cellular-based autograft (CBA) is being used in posterolateral lumbar arthrodesis as a fusion supplementation alternative.

OBJECTIVE

To assess radiographic fusion in patients undergoing posterolateral lumbar fusion with unilateral Trinity CBA compared with contralateral local bone autograft as an internal control.

METHODS

A single surgeon's practice database was interrogated for consecutive patients undergoing primary posterolateral lumbar fusion with Trinity from 2018 to 2021. Patients had Trinity applied unilaterally, with local bone autograft applied contralaterally. Fusion was assessed postoperatively by using CT after 9 months. Demographics and patient-reported outcome measures were collected preoperatively and up to 12 months postoperatively.

RESULTS

Thirty-nine patients were included. There were 81 attempted fusion levels. Overall fusion rate, defined as bony bridging on at least one side of a given level for all levels fused, was 85.2% of patients. No statistically significant difference was observed in fusion rates between CBA versus local bone (79.0% versus 76.54% of levels attempted, respectively, P = 0.3527). Oswestry Disability Index improved by 3 months (P = 0.0152) and was maintained. Two patients required revision for symptomatic nonunion.

CONCLUSIONS

Similar radiographic fusion rates were achieved with Trinity and local bone. Trinity is a viable alternative to local bone in posterolateral lumbar fusion.

Radiographical outcomes of a cellular based allograft following foot/ankle arthrodesis in patients with risk for non-union

Morbidity associated with autograft harvest has led to the need for alternative bone grafts during fusion surgical procedures. The purpose of this study is to evaluate the efficacy of a cellular bone allograft (CBA) in patients who underwent foot/ankle fusion surgery. Retrospective data of patients who underwent foot/ankle arthrodesis using a CBA between XXXX and XXXX were collected from a single site. Patients were at least 18 years of age at the time of surgery and had ankle/foot surgery with Trinity ELITE CBA as the primary or only bone graft. Patients' radiographic union was assessed at three (3) months, six (6) months, nine (9) months, and twelve (12) months. Twenty-two (22) patients and 29 joints were evaluated. The mean age and BMI of the cohort were 54±9yrs and 30.5±6kg/m2, respectively. The surgical indications were degenerative joint diseases, trauma, and arthritis. All patients except one had at least one risk factor for non-union. At 12 months, 21 of the 22 patients (95%) attained successful fusion with an average time of 6 months. In addition, there was a 100% fusion among patients with prior failed fusion, nicotine use, diabetes, neuropathy, and osteoporosis. There was no significant difference in time to fusion between patients with non-union risk factor(s) ≤ 1 and ≥ 2 (p=0.71). No complication or adverse event was reported following the surgery. The use of CBA resulted in high fusion among patients with the risk of non-union. CBA is a viable bone graft substitute for autograft in foot/ankle arthrodesis procedures.

Evaluating Failure Mechanisms for Total Talus Replacement: Contemporary Review

BACKGROUND

As total talus replacement (TTR) grows in popularity as a salvage option for talar collapse, a critical evaluation of the complications associated with this procedure is indicated.

METHODS

In this review of the literature, we present a patient report and provide a review of several complications seen after TTR, including ligamentous instability, infection, and adjacent joint osteoarthritis, which we have encountered in our practice.

RESULTS

Total talus replacement has the potential to reduce pain and preserve range of motion. However, the treating surgeon must be cognizant of the variety of adverse outcomes. We have presented cases of potential devastating complications from our own clinical experience and the literature.

CONCLUSIONS

In conclusion, TTR may have utility in the properly selected patient with end-stage talar collapse, but implant composition, indications, and patient demographic variables complicate the interpretation of the literature.Levels of Evidence: Level III.

A retrospective review of recombinant human platelet-derived growth factor with beta-tricalcium phosphate bone graft substitute use in hindfoot and/or ankle arthrodesis

Background

Nonunion following foot and ankle arthrodesis can cause chronic pain and disability, poor patient satisfaction, and increased healthcare costs. Nonunion rates are reported in 10%-12% of primary foot and/or ankle arthrodesis procedures, with significantly greater rates among patients with high-risk factors such as smoking, diabetes, obesity, or Charcot neuroarthropathy. Recombinant human platelet-derived growth factor BB-homodimer with beta-tricalcium phosphate (rhPDGF-BB/β-TCP) is a bone graft substitute that has demonstrated efficacy in foot and ankle fusion rates that are comparable to autograft.

Methods

Charts and radiographs were retrospectively reviewed on consecutive adult patients undergoing talonavicular, calcaneal-cuboid, subtalar, and/or ankle arthrodesis utilizing rhPDGF-BB/β-TCP bone graft substitute. The primary outcome measures were rate of and mean time to fusion, mean time to return to function, and incidence of adverse events.

Results

This study reviewed133 patients who underwent 209 hindfoot and/or ankle joint arthrodesis procedures with a mean follow-up 20.34 ± 11.05 months. The overall fusion rate was 92.82% (194/209 joints) with a mean time to fusion of 13.14 ± 2.52 weeks and return to function of 16.56 ± 3.26 weeks. Overall, there were 7 (5.26%) patients who experienced an adverse event (AE) with 15 (7.18%) joints experiencing a nonunion.

Conclusion

Fusion rates with rhPDGF-BB/β-TCP bone grafting material compared favorably to autograft controls when used in hindfoot and/or ankle arthrodesis. No AEwas related to rhPDGF-BB/β-TCP. This study suggests that using rhPDGF-BB/β-TCP is effective in hindfoot and/or ankle arthrodesis, even among patients with comorbidities who are at a higher risk of developing a nonunion.

Level of clinical evidence

3.

Characterization of an advanced viable bone allograft with preserved native bone-forming cells

Bone grafts are widely used to successfully restore structure and function to patients with a broad range of musculoskeletal ailments and bone defects. Autogenous bone grafts are historically preferred because they theoretically contain the three essential components of bone healing (ie, osteoconductivity, osteoinductivity, and osteogenicity), but they have inherent limitations. Allograft bone derived from deceased human donors is one alternative that is also capable of providing both an osteoconductive scaffold and osteoinductive potential but, until recently, lacked the osteogenic component of bone healing. Relatively new, cellular bone allografts (CBAs) were designed to address this need by preserving viable cells. Although most commercially-available CBAs feature mesenchymal stem cells (MSCs), osteogenic differentiation is time-consuming and complex. A more advanced graft, a viable bone allograft (VBA), was thus developed to preserve lineage-committed bone-forming cells, which may be more suitable than MSCs to promote bone fusion. The purpose of this paper was to present the results of preclinical research characterizing VBA. Through a comprehensive series of in vitro and in vivo assays, the present results demonstrate that VBA in its final form is capable of providing all three essential bone remodeling properties and contains viable lineage-committed bone-forming cells, which do not elicit an immune response. The results are discussed in the context of clinical evidence published to date that further supports VBA as a potential alternative to autograft without the associated drawbacks.

How to assess consolidation after foot and ankle arthrodesis with computed tomography. A systematic review

PURPOSES

Many studies have been performed that investigate consolidation after arthrodesis of foot and ankle joints. Consolidation in foot and ankle joints is best assessed by computed tomography (CT). However, no golden-standard methodology exists for radiological consolidation assessment from CT after ankle and foot arthrodesis. The aim of this review is to present an overview of the radiological methodologies for consolidation assessment, outcomes on reliability and validity and to advise which methodology should be used.

METHOD

Scientific databases were systematically searched. Eligible studies were studies that 1) performed foot or ankle arthrodesis, 2) mentioned radiological or CT follow-up in abstract, 3) performed postoperative CT in > 50% of patients. Two authors selected eligible studies and performed a risk of bias assessment with the COSMIN tool.

RESULTS

Risk of bias assessment showed that most studies (80%) were at high risk of bias due to poor methodology. The most popular method for consolidation assessment is by subjectively categorizing consolidation into consolidation groups, with a substantial reliability score. Another popular method is to calculate the fusion ratio and then apply a fusion threshold, to distinguish between fused and non-fused joints. This method had an excellent reliability score. In most studies a fusion threshold of 50% is used. However, four studies in this review showed that a 30% fusion threshold may by more valid.

CONCLUSION

Based on the results of this review we would advise to calculate fusion threshold and apply a 30% fusion threshold to distinguish fused from non-fused foot and ankle joints.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVELS OF EVIDENCE

Level IV: Case series.

Treatment of Infected Nonunions With Bone Defects Using Autologous Bone Graft and Absorbable Antibiotic-Loaded Calcium Sulfate-Hydroxyapatite Paste

BACKGROUND

Revision surgery in the presence of infection carries high risks. We describe our results using a new technique to treat these challenging problems. We treated infected nonunions with cavitary voids with adjuvant antibiotic loaded calcium sulfate-hydroxyapatite paste composite and autologous bone graft (ABG) layer technique coupled with stable fixation.

METHODS

Thirty consecutive patients who underwent revision foot and ankle surgery for an infected nonunion were prospectively studied. Following multidisciplinary team workup, surgical debridement and biopsies were undertaken. Bone voids were measured and classified according to containment and size. ABG was mixed and layered with an adjuvant antibiotic-loaded calcium sulfate-hydroxyapatite paste followed by surgical reconstruction including arthrodesis and fixation. Empirical and pathogen-specific antibiotics were instituted until intraoperative sample-specific antibiotics were identified and used. Patients were prospectively followed up for a minimum of 1 year.

RESULTS

The male-female ratio was 16:14, mean age was 51.3 years, and 23.3% smoked at definitive surgery. Void volume was <1 cm³ (n=9), 1-2 cm³ (n = 13), and >2 cm³ (n=8). No patients either were lost to follow-up or had a further infective episode at a mean of 38.3 months; 86.7% united with fusion on imaging. Four patients had radiographic evidence of nonunion; 3 were asymptomatic and 1 required revision surgery (void >2 cm³). Independent ambulation was achieved at an average of 12 weeks, at 1 year mean American Orthopaedic Foot & Ankle Society score was 77.7 (SD 9.59), and the Manchester-Oxford Foot Questionnaire reached an effect size >0.5 in all domains at 1 year following surgery. The union rate was independent of smoking status and vitamin D deficiency (P = .94).

CONCLUSION

Layered autologous bone grafting with adjuvant antibiotic-loaded calcium sulfate-hydroxyapatite paste has been shown to be effective and safe in revision arthrodesis, with low comorbidities in void gaps without infection recurrence.

Limited Evidence for Biological Adjuvants in Hindfoot Arthrodesis: A Systematic Review and Meta-Analysis of Clinical Comparative Studies

BACKGROUND

The purpose of the present study was to evaluate the efficacy of biological adjuvants in patients managed with hindfoot arthrodesis.

METHODS

A systematic review of the PubMed and Embase databases was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines with use of specific search terms and eligibility criteria. Assessment of evidence was threefold: level of evidence by criteria as described in The Journal of Bone & Joint Surgery, quality of evidence according to the Newcastle-Ottawa scale, and conflicts of interest. Meta-analysis was performed with fixed-effects models for studies of low heterogeneity (I2 < 25%) and with random-effects models for studies of moderate to high heterogeneity (I2 ≥ 25%).

RESULTS

A total of 1,579 hindfeet were recruited across all studies, and 1,527 hindfeet were recorded as having completed treatment and follow-up visits. The duration of follow-up ranged from 2.8 to 43 months. Twelve of the 17 included studies comprised patients with comorbidities associated with reduced healing capacity. Based on the random-effects model for nonunion rates for autograft versus allograft, the risk ratio was 0.82 (95% CI, 0.13 to 5.21; I2 = 56%; p = 0.83) in favor of lower nonunion rates for autograft. Based on the random-effects model for rhPDGF/β-TCP versus autograft, the risk ratio was 0.90 (95% CI, 0.74 to 1.10; I2 = 59%; p = 0.30) in favor of lower nonunion rates for rhPDGF/β-TCP.

CONCLUSIONS

There is a lack of data to support the meaningful use of biological adjuvants as compared with autograft/allograft for hindfoot arthrodesis. The meta-analysis favored the use of autograft when compared with allograft but favored rhPDGF/β-TCP when compared with autograft in the short term.

LEVEL OF EVIDENCE

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

A Multicenter, Retrospective, Case Series of Patients With Charcot Neuroarthropathy Deformities Undergoing Arthrodesis Utilizing Recombinant Human Platelet-derived Growth Factor With Beta-Tricalcium Phosphate

Charcot neuroarthropathy has traditionally been treated using both nonsurgical and surgical strategies. Recently, orthobiologics have been used to promote arthrodesis in Charcot reconstructions, obviating the need for bone graft in some cases. Recombinant human platelet-derived growth factor BB homodimer (rhPDGF-BB) in combination with beta-tricalcium phosphate scaffold (β-TCP) is a bone graft substitute shown to have comparable efficacy to autograft in incidence of foot and ankle fusion. This multicenter, consecutive case series analyzed patients undergoing Charcot reconstructions utilizing rhPDGF-BB/β-TCP for joint fusion. In this cohort, 98 patients (62.24% male) with a mean age of 62.82 ± 10.28 years (range 40-87) had a fusion incidence of 217 of 223 joints (97.31%) with a mean time to fusion of 13.09 ± 4.87 weeks (range 6-30). There were 6 nonunions in the patient population. Fusion was defined as ≥50% osseous bridging based on computed tomography and/or radiographic consolidation, in addition to clinical findings. With an overall complication rate of 26.53% (26/98), adverse events occurring in more than 1 patient limb included hardware failures (n = 7, 7.14%), infection (n = 4, 4.08%), wound dehiscence (n = 4, 4.08%), amputation (n = 3, 3.06%), and death (n = 2, 2.04%). There were no adverse events related to the grafting material. From this review, we found rhPDGF-BB/β-TCP to be a safe and effective graft material that can be considered a viable alternative to autograft, even in high-risk patients such as those with Charcot neuroarthropathy.

Comparison of 3D Printed Spherical Implants versus Femoral Head Allografts for Tibiotalocalcaneal Arthrodesis

Successful tibiotalocalcaneal (TTC) arthrodesis can be difficult to achieve in patients with bulk bone defects even with the use of femoral head allograft. Retrograde intramedullary nail placement through custom 3-dimensional (3D) spherical implants is an innovative 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. Patients who underwent TTC arthrodesis with an intramedullary nail along with a 3D spherical implant (n = 8) or femoral head allograft (n = 7) were included in this study. The rate of successful fusion of the tibia, calcaneus, and talar neck to the 3D sphere or femoral head allograft was compared between the groups. The rate of total fused articulations was significantly higher in the 3D sphere group (92%) than the femoral head allograft group (62%; p = .018). The number of patients achieving successful fusion of all 3 articulations was higher in the 3D sphere group (75%) than the femoral head allograft group (42.9%, p = .22). The rate of graft resorption was significantly higher in the femoral head allograft group (57.1%) than the 3D sphere group (0%, p = .016). There were no significant differences between the groups in terms of complications. 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 and may result in improved rates of successful arthrodesis.

A New Treatment for the Reconstruction of the Medial Compartment of the Ankle: The Combined Use of Biological Materials

Fractures, especially if articular and periarticular, are frequently associated to functional and clinical disabling outcomes and chronic pain. In particular, the injuries with loss of bone, ligament, and/or tendon tissue in which the full recovery of the wound area is not obtained are the worst anatomical/pathological conditions to heal. In this study, three different biological materials were used as regenerative approaches to rebuild the medial malleolus fracture of the ankle in which loss of bone, ligament, and tendon tissue occur. In particular, the morselized human bone tissue was combined with the human dermis decellularized, both augmented with homologous platelet-rich plasma. The magnetic resonance imaging study with contrast at the follow-up showed a signal compatible with vascularization of the tissue without sign of degeneration. Our new regenerative approach in which different biological materials were combined together showed a good choice of treatment for the reconstruction of not repairable outcome of a fracture.

Use of Osteobiologics for Fracture Management: The When, What, and How

Osteobiologics are defined as a group of natural and synthetic materials used to augment bone healing. The selection of the most appropriate osteobiologic from the growing list of available options can be a challenging task. In selecting a material, surgeons should weigh a variety of considerations, including the indication for their use (the when), the most suitable substance (the what), and the correct mode of application (the how). This summary reviews these considerations and seeks to provide the surgeon with a basis for informed clinical evidence-based decision-making in their choice of a successful option.

Cortical strut allografts in salvage revision arthroplasty: Surgical technique and clinical outcomes

BACKGROUND

The aim of this study was to present our clinical outcomes and surgical technique in strut allografts preparation using staggered holes to enhance osteointegration and demineralised bone matrix (DBM) as an adjunct to cortical strut allografts in salvage revision arthroplasty patients.

METHODS

Retrospective consecutive series of patients who required strut allograft femoral reconstructions with minimum 2 years follow up between 2012 and 2018. Frozen washed irradiated, cortical struts were used and prepared adding 2 mm staggered drill holes along the length of the strut and applying DBM paste on the graft-host interface. Outcome measures included radiographic strut union, graft resorption, infection and complications.

RESULTS

15 patients included; 3 males and 12 females with median age 72 years (range 60-93). All had significant bony defects (Paprosky III/IV in 12 cases including 3 cases of periprosthetic hip fractures and further 3 cases of periprosthetic knee fractures around revision hinged implants). At final follow up, median 3.8 years (range 2.7-7.2), 14/15 (93.3%) struts had united at a median 6 months (range 5-8), complete incorporation with cortical round-off was seen at median 12 months (range 8-48) in 12/15 (80%) struts, 2/15 (13.3%) show radiographic evidence of proximal minimal graft resorptions although the remainder of the strut had integrated and were asymptomatic. There were no cases of infection.

CONCLUSIONS

Use of strut allografts helps to reconstruct bone defects, restore bone stock, and provide stable fixation for complex patterns of periprosthetic fractures around hip/knee implants and salvage revision cases with 93.3% union rate at median 6 months.

Tibiotalocalcaneal Arthrodesis Using a Novel Retrograde Intramedullary Nail

Background. Tibiotalocalcaneal (TTC) arthrodesis is a common treatment option for complex hindfoot pathology. Overall union rates range from 50% to 86% but can be even lower in certain populations. A novel retrograde intramedullary nail has recently been developed. The purpose of this study was to report fusion rates, time to weight-bearing, and complications with the use of the A3 Fusion Nail. Methods. All patients 18 years or older who underwent TTC arthrodesis with an A3 Fusion Nail at a single institution from 2010 to 2015 with a minimum 3-month follow-up were included in this study. Rates of successful fusion, time to union, time to weight-bearing, and complications were evaluated. A total of 20 patients with an average age of 58.1 years and an average follow-up of 12.5 months met inclusion criteria. Results. Successful TTC arthrodesis was achieved in 14 of 20 patients (70%) overall. Average time to union was 8.1 months, and average time to weight-bearing was 6.8 weeks. Of 20 patients, 17 (85%) required femoral head allograft for bulk bone defects, and the union rate in this subset of patients was 76.5%. The rates of revision surgery (10%) and complications were low. Conclusion. The A3 Fusion Nail demonstrated a favorable safety profile and achieved TTC arthrodesis at a rate consistent with historical data despite being used in a patient population at high risk for nonunion. In patients with bulk bone defects at high risk for nonunion, the A3 Fusion Nail demonstrated superior rates of fusion (76.5%) to those reported in the literature (50%).Level of Evidence: Level III: Retrospective cohort study.

Comparison of Tibiotalocalcaneal Arthrodeses Using a Sustained Dynamic Compression Nail Versus Nondynamized Nails

Background. Tibiotalocalcaneal (TTC) arthrodesis is a common treatment option for hindfoot arthritis and deformity. Loss of compression over time with statically locked nails may contribute to nonunion. A novel retrograde intramedullary nail with an internal pseudoelastic component has recently been used to provide sustained dynamic compression (SDC). The purpose of this study was to compare fusion rates and time to union between the SDC and nondynamized (ND) nails. Methods. All patients who underwent TTC arthrodesis with an intramedullary nail at a single institution from 2013 to 2017 and who had at least 1 year of follow-up were included in this study. Baseline patient and operative characteristics were collected and compared between the sustained SDC and ND nail groups. The rate of successful fusion, time to union, and complications were compared between the groups. Results. The SDC cohort had a significantly faster time to union by 3.9 months (P = .049). The SDC cohort had a higher fusion rate (78.0%) compared with the ND nail cohort (75.0%), although this was not statistically significant (P = .75). The SDC nail was used significantly (P < .05) more often in patients with known risk factors for nonunion, including female sex, smoking, revision surgery, prior trauma, and patients requiring 3D cage implants for significant bone loss. There were no differences between the groups in terms of complications. Conclusion. The SDC nail has been shown to achieve successful arthrodesis in a population at high risk for nonunion, using less hardware, and at a faster rate than ND nails. Level of Evidence: Level III: Retrospective, comparative study.

A Comparative Evaluation of Commercially Available Cell-Based Allografts in a Rat Spinal Fusion Model

Background

To evaluate the comparative abilities of commercially available, viable, cellular bone allografts to promote posterolateral spinal fusion.

Methods

Human allografts containing live cells were implanted in the athymic rat model of posterolateral spine fusion. Three commercially available allogeneic cellular bone matrices (Trinity Evolution, Trinity ELITE and Osteocel Plus) were compared with syngeneic iliac crest bone as the control. All spines underwent radiographs, manual palpation, and micro-computed tomography (CT) analysis after excision at 6 weeks. Histological sections of randomly selected spines were subjected to semiquantitative histopathological scoring for bone formation.

Results

By manual palpation, posterolateral fusion was detected in 40% (6/15) of spines implanted with syngeneic bone, whereas spines implanted with Trinity Evolution and Trinity ELITE allografts yielded 71% (10/14) and 77% (10/13) fusion, respectively. Only 7% (1/14) of spines implanted with Osteocel Plus allografts were judged fused by manual palpation (statistically significantly less than ELITE, P < .0007, and Evolution, P < .0013). The mineralized cancellous bone component of the allografts confounded radiographic analysis, but Trinity Evolution (0.452 ± 0.064) and Trinity ELITE (0.536 ± 0.109) allografts produced statistically significantly higher bone fusion mass volumes measured by quantitative micro-CT than did syngeneic bone (0.292 ± 0.109, P < .0001 for ELITE and P < .003 for Evolution) and Osteocel Plus (0.258 ± 0.103, P < .0001). Semiquantitative histopathological scores supported these findings because the total bone and bone marrow scores reflected significantly better new bone and marrow formation in the Trinity groups than in the Osteocel Plus group.

Conclusions

The Trinity Evolution and Trinity ELITE cellular bone allografts were more effective at creating posterolateral fusion than either the Osteocel Plus allografts or syngeneic bone in this animal model.

Clinical Relevance

The superior fusion rate of Trinity cellular bone allografts may lead to better clinical outcome of spinal fusion surgeries.

Results of Tibia and Fibula Osteotomies Performed Concomitant to Total Ankle Replacement

BACKGROUND

Neutral ankle alignment along with medial and lateral support are paramount to the success of total ankle replacement (TAR). Fibula, intra-articular medial malleolus, and supramalleolar tibia osteotomies have been described to achieve these goals; however, the literature is scant with outcomes and union rates of these osteotomies performed concomitant to TAR. The purpose of this study was to describe our results.

METHODS

A retrospective review was performed to identify patients who had a concomitant tibia, fibula, or combined tibia and fibula osteotomy at the same time as TAR. Routine radiographs were used to assess osteotomy union rates and changes in alignment. Outcomes questionnaires were evaluated preoperatively and at most recent follow-up. Twenty-six patients comprising 4% of the total TAR cohort were identified with a mean follow-up of 3.9 years.

RESULTS

There were 12 combined tibia and fibula osteotomies, 9 isolated tibia osteotomies, and 5 isolated fibula osteotomies. The union rate for these osteotomies was 92%, 100%, and 100%, respectively. Mean coronal alignment improved from 15.2 to 2.1 degrees (P < .001). There was significant improvement in patient-reported outcome scores, including Short Form-36, Short Musculoskeletal Function Assessment, and visual analog scale pain. There was 1 failure in the study.

CONCLUSION

These data demonstrate successful use of tibia, fibula, or combined tibia and fibula osteotomies at the same time as TAR in order to gain neutral ankle alignment. The overall union rate was 96% with significant improvement in alignment, pain, and patient-reported outcomes. We believe concomitant osteotomies can be considered a successful adjunctive procedure to TAR.

LEVEL OF EVIDENCE

Level III, retrospective comparative series.

Methods of Cryoprotectant Preservation: Allogeneic Cellular Bone Grafts and Potential Effects

Debridement of the bone surface during a surgical fusion procedure initiates an injury response promoting a healing cascade of molecular mediators released over time. Autologous grafts offer natural scaffolding to fill the bone void and to provide local bone cells. Commercial bone grafting products such as allografts, synthetic bone mineral products, etc., are used to supplement or to replace autologous grafts by supporting osteoinductivity, osteoconductivity, and osteogenesis at the surgical site. To assure osteogenic potential, preservation of allogeneic cells with cryoprotectants has been developed to allow for long-term storage and thus delivery of viable bone cells to the surgical site. Dimethyl sulfoxide (DMSO) is an intracellular cryoprotectant commonly used because it provides good viability of the cells post-thaw. However, there is known cytotoxicity reported for DMSO when cells are stored above cryogenic temperatures. For most cellular bone graft products, the cryoprotectant is incorporated with the cells into the other mineralized bone and demineralized bone components. During thawing, the DMSO may not be sufficiently removed from allograft products compared to its use in a cell suspension where removal by washing and centrifugation is available. Therefore, both the allogeneic cell types in the bone grafting product and the local cell types at the bone grafting site could be affected as cytotoxicity varies by cell type and by DMSO content according to reported studies. Overcoming cytotoxicity may be an additional challenge in the formation of bone at a wound or surgical site. Other extracellular cryoprotectants have been explored as alternatives to DMSO which preserve without entering the cell membrane, thereby providing good cellular viability post-thaw and might abrogate the cytotoxicity concerns.

Orthobiologics

Use of orthobiologics in sports medicine and musculoskeletal surgery has gained significant interest. However, many of the commercially available and advertised products are lacking in clinical evidence. Widespread use of products before fully understanding their true indications may result in unknown adverse outcomes and may also lead to increased health care costs. As more products become available, it is important to remain judicial in use and to practice evidence-based medicine. Likewise, it is important to continue advances in research in hopes to improve surgical outcomes. This article reviews clinical evidence behind common orthobiologics in the treatment of foot and ankle pathology.

The Use of Bone Grafts, Bone Graft Substitutes, and Orthobiologics for Osseous Healing in Foot and Ankle Surgery

Achieving fusion in osseous procedures about the foot and ankle presents unique challenges to the surgeon. Many patients have comorbidities that reduce osseous healing rates, and the limited space and high weightbearing demand placed on fusion sites makes the choice of bone graft, bone graft substitute, or orthobiologic agent of utmost importance. In this review, we discuss the essential characteristics of grafts, including their osteoconductive, osteoinductive, osteogenic, and angiogenic properties. Autologous bone graft remains the gold standard and contains all these properties. However, the convenience and lack of donor site morbidity of synthetic bone grafts, allografts, and orthobiologics, including growth factors and allogenic stem cells, has led to these being used commonly as augments.

What Is the Treatment "Algorithm" for Infection After Ankle or Hindfoot Arthrodesis?

RECOMMENDATION

There is no universal algorithm for addressing the infected ankle or subtalar arthrodesis. A potential algorithm created by consensus is.

LEVEL OF EVIDENCE

Consensus.

DELEGATE VOTE

Agree: 100%, Disagree: 0%, Abstain: 0% (Unanimous, Strongest Consensus).

Clinical applications of allografts in foot and ankle surgery

PURPOSE

The purpose of this review is to systematically analyse current literature on the use of allografts in the surgical treatment of foot and ankle disorders in adult patients. Based on this study, we propose evidence-based recommendations.

METHODS

The database for PubMed was searched for all published articles. No timeframe restrictions were applied. Clinical studies eligible for inclusion met the following criteria: performed on patients over 18 years old; subject to surgical treatment of foot and ankle disorders; with report on the outcome of the use of allografts; with a report and assessment of pain and function, or equivalent; minimum follow-up of 1 year was required. Two reviewers independently screened and selected studies for full-text analysis from title and abstract. 107 studies were included from 1113 records. Studies were grouped according to surgical indications into ten categories: musculoskeletal tumours (n = 16), chronic ankle instability (n = 15), ankle arthritis (n = 14), osteochondral lesions of the talus (n = 12), Achilles tendon defects (n = 11), other tendon defects (n = 9), fusions (n = 9), fractures (n = 8), hallux rigidus (n = 3) and other indications (n = 10).

RESULTS

Most studies displayed evidence level of IV (n = 57) and V (n = 39). There was one level I, one level II and nine level III studies. Most studies reported allografting as a good option (n = 99; 92.5%). Overall complication rate was 17% (n = 202).

CONCLUSIONS

Fair evidence (Grade B) was found in favour of the use of allografts in lateral ankle ligament reconstruction or treatment of intra-articular calcaneal fracture. Fair evidence (Grade B) was found against the use of allogeneic MSCs in tibiotalar fusions.

LEVEL OF EVIDENCE

V.

Autograft, Allograft, and Bone Graft Substitutes: Clinical Evidence and Indications for Use in the Setting of Orthopaedic Trauma Surgery

Bone grafts are the second most common tissue transplanted in the United States, and they are an essential treatment tool in the field of acute and reconstructive traumatic orthopaedic surgery. Available in cancellous, cortical, or bone marrow aspirate form, autogenous bone graft is regarded as the gold standard in the treatment of posttraumatic conditions such as fracture, delayed union, and nonunion. However, drawbacks including donor-site morbidity and limited quantity of graft available for harvest make autograft a less-than-ideal option for certain patient populations. Advancements in allograft and bone graft substitutes in the past decade have created viable alternatives that circumvent some of the weak points of autografts. Allograft is a favorable alternative for its convenience, abundance, and lack of procurement-related patient morbidity. Options include structural, particulate, and demineralized bone matrix form. Commonly used bone graft substitutes include calcium phosphate and calcium sulfate synthetics-these grafts provide their own benefits in structural support and availability. In addition, different growth factors including bone morphogenic proteins can augment the healing process of bony defects treated with grafts. Autograft, allograft, and bone graft substitutes all possess their own varying degrees of osteogenic, osteoconductive, and osteoinductive properties that make them better suited for different procedures. It is the purpose of this review to characterize these properties and present clinical evidence supporting their indications for use in the hopes of better elucidating treatment options for patients requiring bone grafting in an orthopaedic trauma setting.

[Recent progress in foot and ankle surgery]

The article focuses on the recent progress in foot and ankle surgery, including the diagnosis of disease, treatment protocols, outcomes, and evaluation tools as well as other innovations. New and accurate diagnostic modalities and measurements have undergone a breakthrough. Diagnostic modalities tend to be simpler and less expensive. Measurement tools also change to simpler and more accurate. The accuracy and efficacy of surgery and the minimally invasive method have become more popular and important. New treatments and basic research have also made breakthroughs.

Living Cryopreserved Bone Allograft as an Adjunct for Hindfoot Arthrodesis

Hindfoot arthrodesis is a frequently performed procedure by foot and ankle surgeons. The relatively high nonunion rate associated with these procedures has led surgeons to use adjunctive bone graft to help augment osseous union. Cellular bone allografts are a specific type of graft that incorporates osteoconductive, osteoinductive, and osteogenic properties while also eliminating the common disadvantages of autografts and traditional allografts. This article discusses the role of cellular bone allografts in hindfoot arthrodesis procedures, a review of current literature, and a comparison of available products.

An original fibular shortening osteotomy technique in tibiotalar arthrodesis

Tibiotalar arthrodesis (TTA) is the gold-standard treatment for advanced ankle osteoarthritis. We describe an original fibular shortening osteotomy (FSO) performed during TTA, to allow complete talar ascension and reduce the nonunion rate. Forty-two FSOs were associated to TTA (19 fixed by cross-screwing and 23 by anatomic plates) and assessed clinically and radiographically. At 24.7 months' follow-up, fusion rates were 97.6% for TTA and 100% for FSO, with mean fusion time of 5.2 months. One infection and 1 nonunion (4.7%) required further surgery, with complete resolution. Radiological and clinical outcome in TTA, lack of specific complications of FSO and ease of implementation encourage us to publish the technique.

Osseous Healing in Foot and Ankle Surgery with Autograft, Allograft, and Other Orthobiologics

In the surgical treatment of foot and ankle abnormality, many problems require bone grafting for successful osseous union. Nonunion, reconstruction, and arthrodesis procedures pose specific challenges due to bony defects secondary to trauma, malunions, or previous surgery. Nonunion in foot and ankle arthrodesis is a significant risk and is well documented in recent literature. This article is a review of the recent literature regarding the use of bone graft and orthobiologics in foot and ankle surgery.

Efficacy of a Cellular Bone Allograft for Foot and Ankle Arthrodesis and Revision Nonunion Procedures

BACKGROUND

Bone graft substitutes are often required in patients at risk for nonunion, and therefore, an allograft that most closely mimics an autograft is highly sought after. This study explored the utility and efficacy of a cellular bone allograft used for foot and ankle arthrodesis and revision nonunion procedures in a patient population at risk for nonunion.

METHODS

An institutional review board-approved retrospective review of consecutive patients who underwent arthrodesis and revision nonunion procedures with a cellular bone allograft was performed at a single academic institution. No external sources of funding were provided for this study. Inclusion criteria included patients who were more than 1 year after surgery or less than 1 year after surgery if they had undergone a second operative procedure for nonunion or if they had computed tomography-documented union. Forty operative procedures in 36 patients with a mean follow-up of 13 months (range, 6-25 months) were included for data analysis. All patients had at least one of the following risk factors associated with nonunion: current smoker, diabetes, avascular necrosis (AVN) of the involved bone, active same-site operative infection, history of nonunion, previous same-site surgery, or gap of 5 mm or greater after joint preparation. The primary outcome was radiographic union.

RESULTS

The union rate in this high-risk population was 83% (33/40). Univariate analysis demonstrated that the use of a cellular bone allograft helped mitigate the presence of risk factors known to cause nonunion. There was no significant difference in fusion rates among groups with current smoking, AVN of the involved bone, active same-site operative infections, history of nonunion, rheumatoid arthritis on medication, previous same-site operative procedures or infections, or a gap of 5 mm or greater after joint preparation. However, in this population, diabetic and female patients remained at a high risk of recurrent nonunion ( P = .0015), despite the use of a cellular bone allograft. Chi-square analysis of patients with increasing numbers of risk factors directly correlated with an increased risk of nonunion ( P = .025). Four wound complications were reported in this cohort that required irrigation and debridement (10%).

CONCLUSION

These data demonstrated a union rate of 83% in patients with risk factors known to cause nonunion. The benefits of the use of a cellular bone allograft allowed for the avoidance of morbidity associated with autograft harvesting while still improving the local biology to facilitate fusion in a difficult patient population to attain a successful fusion mass.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Arthroscopic arthrodesis for ankle arthritis without bone graft

Background

Ankle arthrodesis is considered by many to be the standard operative treatment for end-stage ankle arthritis. The purpose of this study was to perform a new technique for ankle joint surface and determine the outcome for the union rates of ankle arthroscopic arthrodesis.

Methods

A total of 68 patients with posttraumatic arthritis, primary osteoarthritis, and rheumatoid arthritis were treated by ankle arthroscopic arthrodesis between May 2007 and December 2012. Our surgical indication was deformity less than 15° measured by weight-bearing radiographs. Firstly, the remaining articular cartilage was removed with different curettes and shavers. Then, the new technique (microfracture) was done at tibiotalar surfaces. Finally, the ankle was fixed with two cannulated percutaneous screws. The wound healing, complications, postoperative radiographs, and American Orthopaedic Foot and Ankle Society (AOFAS) score were evaluated.

Results

The average follow-up time was 32 months (range 25–58 months). There was no bone grafting, and a fusion rate of 100% was achieved. The average fusion time was 12.1 weeks. One patient developed superficial infection at 2 weeks postoperatively and was cured by nonsurgical treatment. No deep infections, deep venous thrombosis, or revision surgery were observed. Screws had been removed in four patients because of prominence. One patient had fusion in the subtalar joint because of arthritis at 5 years postoperatively. At the last follow-up, radiographic signs of developed or progressing arthritis were observed in nine patients at subtalar joint and in four patients at talonavicular joint. At 1-year follow-up, the mean AOFAS ankle/hindfoot score had increased to 84 from a mean preoperative value of 38 (P < 0.01).

Conclusions

Arthroscopic arthrodesis provides surgeons with an alternative to traditional open techniques for the management of severe ankle arthritis. Our data show that preparation of the joint surface with microfracture is an effective technique to increase the union rate of arthroscopic ankle arthrodesis, while bone graft and other promoting substances are not necessary to be routinely used.

Electronic supplementary material

The online version of this article (doi:10.1186/s13018-016-0490-y) contains supplementary material, which is available to authorized users.

Efficacy of a Cellular Allogeneic Bone Graft in Foot and Ankle Arthrodesis Procedures

A cellular allogeneic bone graft can be used in patients at high risk for nonunion after arthrodesis surgery. This study explores the utility and efficacy of MAP3 in foot and ankle arthrodesis procedures. Map3 is a cellular allogeneic bone graft that contains osteogenic, osteoconductive, osteoinductive, and angiogenic properties. A total of 23 mostly high-risk patients were included in this study. The overall fusion rate was 83%. Univariate analysis demonstrated diabetic patients remain at risk of recurrent nonunion (P<.001) despite supplementation with MAP3. These data demonstrate successful fusion in high-risk patients when MAP3 is used.

The Importance of Sufficient Graft Material in Achieving Foot or Ankle Fusion

BACKGROUND

Nonunion, an important complication following foot and ankle arthrodesis, causes substantial morbidity and disability. In patients undergoing hindfoot and ankle arthrodesis, autogenous bone graft (autograft) or a suitable alternative is often used to promote osseous fusion across the joint. This study assessed the importance of adequate graft material in the fusion space to achieve joint fusion during ankle and hindfoot arthrodesis.

METHODS

This study used data from a previously published clinical trial of grafting material (recombinant human platelet-derived growth factor-BB with beta-tricalcium phosphate [rhPDGF-BB/β-TCP] or autograft) for healing in hindfoot and ankle arthrodesis to correlate the amount of graft fill at 9 weeks with ultimate healing. Patients who received supplemental graft material for ankle or hindfoot arthrodesis for end-stage ankle or hindfoot arthritis were stratified according to nonunion risk factors and surgical fusion site. Patients underwent arthrodesis using standard rigid internal fixation. Graft fill was defined as "adequate" if the material occupied ≥50% of the cross-sectional area of the fusion space on a computed tomography (CT) scan made at 9 weeks. Fusion was defined as osseous bridging of ≥50% of each articulation on a CT scan made at 24 weeks. Three hundred and seventy-nine patients with 573 joints (383 managed with rhPDGF-BB/β-TCP and 190 managed with autograft) that underwent arthrodesis had complete follow-up with 9-week and 24-week CT scans available.

RESULTS

Overall, 472 (82%) of 573 joints had adequate graft fill; of those, 383 (81%) were successfully fused at 24 weeks compared with 21 (21%) of 101 joints without adequate graft fill (p < 0.0001). Absolute fusion rate differences (joints with adequate fill minus those without adequate fill) were consistent across joints (61% to 63%) and for graft materials. The overall odds ratio (OR) of successful fusion in joints with adequate graft fill compared with those without adequate graft fill was 16.4 (95% confidence interval, 9.6 to 27.9).

CONCLUSIONS

This study demonstrates an association between the amount of graft material and successful hindfoot and ankle arthrodesis. Graft material filling of ≥50% of the fusion space at 9 weeks, regardless of type or origin, was associated with significantly higher fusion rates at 24 weeks.

LEVEL OF EVIDENCE

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

Clinical evaluation of an allogeneic bone matrix containing viable osteogenic cells in patients undergoing one- and two-level posterolateral lumbar arthrodesis with decompressive laminectomy

Background

Trinity Evolution® cellular bone allograft (TE) possesses the osteogenic, osteoinductive, and osteoconductive elements essential for bone healing. The purpose of this study is to evaluate the radiographic and clinical outcomes when TE is used as a graft extender in combination with locally derived bone in one- and two-level instrumented lumbar posterolateral arthrodeses.

Methods

In this retrospective evaluation, a consecutive series of subject charts that had posterolateral arthrodesis with TE and a 12-month radiographic follow-up were evaluated. All subjects were diagnosed with degenerative disc disease, radiculopathy, stenosis, and decreased disc height. At 2 weeks and at 3 and 12 months, plain radiographs were performed and the subject’s back and leg pain (VAS) was recorded. An evaluation of fusion status was performed at 12 months.

Results

The population consisted of 43 subjects and 47 arthrodeses. At 12 months, a fusion rate of 90.7 % of subjects and 89.4 % of surgical levels was observed. High-risk subjects (e.g., diabetes, tobacco use, etc.) had fusion rates comparable to normal patients. Compared with the preoperative leg or back pain level, the postoperative pain levels were significantly (p < 0.0001) improved at every time point. There were no adverse events attributable to TE.

Conclusions

Fusion rates using TE were higher than or comparable to fusion rates with autologous iliac crest bone graft that have been reported in the recent literature for posterolateral fusion procedures, and TE fusion rates were not adversely affected by several high-risk patient factors. The positive results provide confidence that TE can safely replace autologous iliac crest bone graft when used as a bone graft extender in combination with locally derived bone in the setting of posterolateral lumbar arthrodesis in patients with or without risk factors for compromised bone healing.

Trial registration

Because of the retrospective nature of this study, the trial was not registered.