Dynamizations and Exchanges: Success Rates and Indications

Reconstruction of gap non-union tibia with composite use of extramedullary fixation and bone transport by monorail fixator: a prospective case series

Introduction

Non-union is a complex, multifactorial orthopaedic problem that requires multiple treatment modalities for its management. It can result from infection, segmental bone loss, soft-tissue loss, and associated host factors. External fixators as management of gap non-union are bulky and give rise to a number of complications In our study, we have described a technique where we have used extramedullary fixation in the form of a tibial locking plate and transportation of part of the tibial bone after corticotomy by a monorail fixator.

Materials and Methods

The procedure was done in two stages where internal and external fixation was done after creating a gap at the non-union site. The bone was transported after corticotomy and fixed to the internal fixation device in the second stage. The external fixator was removed in the second stage and the patient was then followed up till the bony union. The evaluation was done by functional and radiological assessment along with the complications noted with the described procedure.

Results

Ten patients were enrolled in the study with a mean age of 33 years. The mean age of the patients was 33.7 ± 11.32 years with a mean size of the defect was 4.8 ± 1.7 cm. At 30 weeks out of nine patients, three patients had excellent and six had good functional results on the Association of Surgeons for Application and Methodology of Ilizarov (ASAMI) scale. The composite Musculoskeletal Tumor Society (MSTS) score was 76.66 % at the end of 30 weeks of follow-up. The mean time of consolidation was 134.4 days, whereas the mean union time was 145 days from index surgery. Ankle stiffness was the most common complication affecting 50% of the patients. Following closely was pin tract infection, which was present in 40% of the patients. According to Paley's classification, there were 11 obstacles, two problems and none were true complications.

Conclusion

The integrated fixation is both safe and effective and has the advantage of early removal of the external fixator and a low complication rate as compared to use of a bulky conventional fixator alone. Moreover, it gives protection to the regenerated bone for a long period. So, this technique can be recommended for the management of segmental tibial defects.

Polytherapy versus monotherapy in the treatment of tibial non-unions: a retrospective study

BACKGROUND

Treating tibial non-unions efficiently presents a challenge for orthopaedic trauma surgeons. The established gold standard involves implanting autologous bone graft with adequate fixation, but the addition of biologicals according to the so-called diamond concept has become increasingly popular in the treatment of non-unions. Previous studies have indicated that polytherapy, which involves implanting mesenchymal stem cells, bioactive factors and osteoconductive scaffolds, can improve bone healing. This study aims to evaluate the efficacy of polytherapy compared with monotherapy in treating tibial non-unions of varying severity.

MATERIALS AND METHODS

Data from consecutive tibial non-unions treated between November 2014 and July 2023 were retrospectively analysed. The Non Union Scoring System (NUSS) score before non-union surgery, and the Radiographic Union Score for Tibial fractures (RUST), scored at 1, 3, 6, 9, 12 and 18 months post-surgery, were recorded. Initially, a comparison was made between the polytherapy and monotherapy groups. Subsequently, patients receiving additional surgical non-union treatment were documented, and the frequency of these treatments was tallied for a subsequent per-treatment analysis.

RESULTS

A total of 34 patients were included and divided into a polytherapy group (n = 15) and a monotherapy group (n = 19). The polytherapy group demonstrated a higher NUSS score (44 (39, 52) versus 32 (29, 43), P = 0.019, z = -2.347) and a tendency towards a higher success rate (93% versus 68%, P = 0.104) compared with the monotherapy group. For the per-treatment analysis, 44 treatments were divided into the polytherapy per-treatment group (n = 20) and the monotherapy per-treatment group (n = 24). The polytherapy per-treatment group exhibited a higher NUSS score (48 (43, 60) versus 38 (30, 50), P = 0.030, z = -2.173) and a higher success rate (95% versus 58%, P = 0.006) than the monotherapy per-treatment group. Within the monotherapy per-treatment group, the NUSS score displayed excellent predictive performance (AUC = 0.9143). Setting the threshold value at 48, the sensitivity and specificity were 100.0% and 70.0%, respectively.

CONCLUSIONS

Polytherapy is more effective than monotherapy for severe tibial non-unions, offering a higher success ratio. The NUSS score supports decision-making in treating tibial non-unions.

LEVEL OF EVIDENCE

Level III.

Approach to Tibial Shaft Nonunions: Diagnosis and Management

The tibia is the most common long bone at risk for nonunion with an annual incidence ranging from 12% to 19%. This topic continues to be an area of research as management techniques constantly evolve. A foundational knowledge of the fundamental concepts, etiology, and risk factors for nonunions is crucial for success. Treatment of tibial shaft nonunions often requires a multidisciplinary effort. This article provides guidance based on the most recent literature that can be used to aid the treating provider in the diagnosis, workup, and management of tibial shaft nonunions.

Radiographic Union Assessment in Surgically Treated Distal Femur Fractures: A Systematic Review

BACKGROUND

Distal femur fractures are known to have challenging nonunion rates. Despite various available treatment methods aimed to improve union, optimal interventions are yet to be determined. Importantly, there remains no standard agreement on what defines radiographic union. Although various proposed criteria of defining radiographic union exist in the literature, there is no clear consensus on which criteria provide the most precise measurement. The use of inconsistent measures of fracture healing between studies can be problematic and limits their generalizability. Therefore, this systematic review aims to identify how fracture union is defined based on radiographic parameters for surgically treated distal femur fractures in current literature.

METHODS

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, Medline, EMBASE, Cochrane Central Register of Controlled Trials, and Web of Science Core Collection databases were searched from inception to October 2022. Studies that addressed surgically treated distal femur fractures with reported radiographic union assessment were included. Outcomes extracted included radiographic definition of union; any testing of validity, reliability, or responsiveness; reported union rate; reported time to fracture union; and any functional outcomes correlated with radiographic union.

RESULTS

Sixty articles with 3,050 operatively treated distal femur fractures were included. Operative interventions included lateral locked plate (42 studies), intramedullary nail (15 studies), dynamic condylar screw or blade plate (7 studies), dual plate or plate and nail construct (5 studies), distal anterior-posterior/posterior-anterior screws (1 study), and external fixation with a circular frame (1 study). The range of mean follow-up time reported was 4.3 to 44 months. The most common definitions of fracture union included "bridging or callus formation across 3 of 4 cortices" in 26 (43%) studies, "bony bridging of cortices" in 21 (35%) studies, and "complete bridging of cortices" in 9 (15%) studies. Two studies included additional assessment of radiographic union using the Radiographic Union Scale in Tibial fracture (RUST) or modified Radiographic Union Scale in Tibial fracture (mRUST) scores. One study included description of validity, and the other study included reliability testing. The reported mean union rate of distal femur fractures was 89% (range 58%-100%). The mean time to fracture union was documented in 49 studies and found to be 18 weeks (range 12-36 weeks) in 2,441 cases. No studies reported correlations between functional outcomes and radiographic parameters.

CONCLUSION

The current literature evaluating surgically treated distal femur fractures lacks consistent definition of radiographic fracture union, and the appropriate time point to make this judgement is unclear. To advance surgical optimization, it is necessary that future research uses validated, reliable, and continuous measures of radiographic bone healing and correlation with functional outcomes.

LEVEL OF EVIDENCE

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

Effects of dynamization timing and degree on bone healing of different fracture types

Dynamization, that is, increasing interfragmentary movement (IFM) by reducing fixation stiffness from a rigid to a more flexible state, has been successfully used in clinical practice to promote fracture healing. However, it remains unclear how dynamization timing and degree affect bone healing of different fracture types. Finite element models of tibial fractures based on the OTA/AO classification (Simple: A1-Spiral, A2-Oblique, A3-Transverse; Wedge: B2-Spiral, B3-Fragmented; Complex: C2-Segment, C3-Irregular), in combination with fuzzy logic-based mechano-regulatory tissue differentiation algorithms, were used to simulate the healing process when dynamization of varied degrees (dynamization coefficient or DC = 0-0.9; 0.9 represents 90% reduction in the fixation stiffness relative to a rigid fixation) were applied at different time points after fracture. The fuzzy logic-based algorithms have been validated with a preclinical animal model. The results showed that the healing responses of type A fractures were more sensitive to the changes in dynamization degree and timing comparing with type B or C fractures. Additionally, the optimal dynamization regime for each fracture type was different. For type A fractures, a moderate dynamization degree (e.g., DC = 0.5) applied after Week 1 promoted the recovery of biomechanical integrity. For type B and C fractures, the effective dynamization included a greater dynamization degree (DC = 0.7) applied after Week 2. Our results further demonstrated that the fracture morphology affected interfragmentary strain environments within the callus, leading to varied healing results for different fracture types. These results suggest that the effects of dynamization are highly dependent of the fracture types. Therefore, specific dynamization strategies should be chosen for different fracture types to achieve optimal healing outcomes.

Fixators dynamization for delayed union and non-union of femur and tibial fractures: a review of techniques, timing and influence factors

The optimal balance between mechanical environment and biological factors is crucial for successful bone healing, as they synergistically affect bone development. Any imbalance between these factors can lead to impaired bone healing, resulting in delayed union or non-union. To address this bone healing disorder, clinicians have adopted a technique known as "dynamization" which involves modifying the stiffness properties of the fixator. This technique facilitates the establishment of a favorable mechanical and biological environment by changing a rigid fixator to a more flexible one that promotes bone healing. However, the dynamization of fixators is selective for certain types of non-union and can result in complications or failure to heal if applied to inappropriate non-unions. This review aims to summarize the indications for dynamization, as well as introduce a novel dynamic locking plate and various techniques for dynamization of fixators (intramedullary nails, steel plates, external fixators) in femur and tibial fractures. Additionally, Factors associated with the effectiveness of dynamization are explored in response to the variation in dynamization success rates seen in clinical studies.

Great debates in trauma biomechanics

At the 2021 annual meeting of the Orthopaedic Trauma Association, the Basic Science Focus Forum hosted its first ever debate-style symposium focused on biomechanics and fracture repair. The 3 subjects of debate were "Mechanics versus Biology-Which is 'More Important' to Consider?" "Locked Plate versus Forward Dynamization versus Reverse Dynamization-Which Way Should I Go?" and "Sawbones versus Cadaver Models-What Should I Believe Most?" These debates were held because fracture healing is a highly organized synergistic response between biological factors and the local mechanical environment. Multiple studies have demonstrated that both factors play roles in governing bone healing responses, and the causal relationships between the 2 remain unclear. The lack of clarity in this space has led to a spectrum of research with the common goal of helping surgeons make good decisions. Before reading further, the reader should understand that the questions posed in the debate titles are unanswerable and might represent a false choice. Instead, the reader should appreciate that the debates were held to gain a more thorough understanding of these topics based on the current state of the art of experimental and clinical studies, by using an engaging and thought-provoking format.

Use of Teriparatide in preventing delayed bone healing and nonunion: a multicentric study on a series of 20 patients

BACKGROUND

Delayed bone healing and nonunions represent a great challenge for the orthopedic surgeon. In addition to traditional surgical approaches, increasing attention is being given to the use of systemic anabolic therapy with Teriparatide, whose efficacy in preventing osteoporotic fractures is widely validated and whose application as a promoter of bone healing has been described but it is still debated. The aim of the study was to evaluate bone healing in a series of patients with delayed unions or nonunions treated with Teriparatide in conjunction with eventual appropriate surgical procedure.

METHODS

Twenty patients with an unconsolidated fracture that were treated at our Institutions from 2011 to 2020 with Teriparatide were retrospectively included into the study. The pharmacological anabolic support was used off-label with a planned duration of 6 months; radiographic healing was evaluated at 1-, 3- and 6-months follow-up outpatient visits over plain radiographs. Also, eventual side-effects were registered.

RESULTS

Radiographic signs indicative of favorable evolution of the bone callus were observed as early as at 1 month of therapy in 15% of cases; at 3 months, healing progression was appreciated in 80% of cases and complete healing in 10%; at 6 months, 85% of delayed and nonunions had healed. In all patients, the anabolic therapy was well tolerated.

CONCLUSIONS

In accordance to Literature, this study suggests that Teriparatide plays a potentially important role in the treatment of some forms of delayed unions or nou-nions, even in the presence of failure of hardware. The results suggest a greater effect of the drug when associated with a condition in which the bone is in an active phase of callogenesis, or with a "revitalizing" treatment which represents a local (mechanical and/or biological) stimulus to the healing process. Despite the small sample size and the variety of cases, the efficacy of Teriparatide in treating delayed unions or nonunions emerged, highlighting how this anabolic therapy can represent a useful pharmacological support in the treatment of such a pathology. Although the results obtained are encouraging, further studies, particularly prospective and randomized, are needed to confirm the efficacy of the drug, and define a specific treatment algorithm.

Plate Augmentation in Aseptic Femoral Shaft Nonunion after Intramedullary Nailing: A Literature Review

BACKGROUND

Femoral shaft fractures (FSFs) are a frequent injury in traumatology for which intramedullary nailing (IMN) is considered the gold standard treatment. Nonunion (NU) is one of the most frequent complications in FSF treated with IMN, with a percentage from 1.1% to 14%. Plate augmentation (PA), the addition of a compression plate and screws, with or without bone graft has been described as an effective option for the treatment of NU, improving the biomechanical conditions at the fracture site. The aim of this review was to analyze the literature relating to the use of PA in NU after IMN in FSFs to assess the efficacy of the technique.

METHODS

An electronic search on PubMed, Google Scholar, and Web of Science was conducted to search for all studies concerning PA of femoral shaft NUs after IMN.

RESULTS

Twenty-four studies were included in the review comprising a total of 502 patients with a mean age of 39.5 years. Of these, 200 hundred patients had atrophic pseudoarthrosis and 123 had hypertrophic pseudoarthrosis, while in 179, the type of pseudoarthrosis was not reported. The most frequently used plate for PA was the dynamic compression plate (DCP); in 87.1% of the cases, the authors added a bone graft to the plate fixation. In 98.0% of the patients, a complete bone union was achieved in a mean time of 5.8 ± 2.12 months.

CONCLUSION

The patients treated with PA included in this review showed a good rate of consolidation in the femoral shaft NUs, with good functional recovery and a low incidence of complications.

Contemporary management of aseptic diaphyseal tibia non-unions - A systematic review

INTRODUCTION

Tibia fractures are the most common long bone injuries encountered in the trauma population. The majority are treated successfully but non-union remains a common complication. A systematic review of current evidence regarding the management for aseptic diaphyseal tibial non-unions was undertaken.

METHODS

A systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), was conducted.

RESULTS

A total of 632 publications were screened for inclusion. Full text review of 91 studies resulted in 26 publications being retained for final review. The majority of patients included in the studies either underwent exchange nailing (n=315) or primary intramedullary nailing (n=174) with respective union rates of 88% and 95% being achieved. The highest union rate (97%) was achieved with the use of fine wire external fixation. The major adjuvant treatment modalities were fibula osteotomies (n=372; 41%), fixation dynamization (n=208; 23%) and bone grafting (n=183; 20%).

CONCLUSION

The lack of standardization in reporting of outcomes and the diversity of management strategies employed precludes definitive conclusions or recommendations. Further research is required to ascertain the ideal treatment strategy in the management of aseptic tibial diaphyseal non-unions.

LEVEL OF EVIDENCE

IV.

Plate augmentation and bone grafting in treatment of femoral shaft nonunion initially fixed by intramedullary nail

INTRODUCTION

This study aims to evaluate the results of plate augmentation and bone grafting without removing the nail in the treatment of nonunited, nailed femoral shaft fractures.

METHODS

Twenty patients with atrophic nonunion femoral shaft fractures initially fixed by intramedullary nail were treated by augmentation plating and iliac bone graft with retention of the nail. Patients were evaluated at regular intervals using an X-ray and Wu scoring system, which assesses clinical and radiological signs of healing.

RESULTS

All 20 patients achieved bony union at a mean time of 4.9 months (3-8 months). According to Wu's score, 12 cases showed excellent results, and 8 cases obtained good results with no complications recorded.

CONCLUSION

augmentation plating and iliac bone graft provide a good and safe method of treatment of previously nailed and non-united femoral shaft fractures.

LEVEL OF EVIDENCE

Level 4; Case Series.

The combined effects of dynamization time and degree on bone healing

Dynamization, increasing the interfragmentary movement (IFM) by reducing the fixation stiffness from a rigid to a more flexible condition, is widely used clinically to promote fracture healing. However, it remains unknown how dynamization degree (relative change in fixation stiffness/IFM from a rigid to a flexible fixation) affects bone healing at various stages. To address this issue, we used a fuzzy logic-based mechano-regulated tissue differentiation algorithm on published experimental data from a sheep osteotomy healing model. We applied a varied degree of dynamization, from 0 (fully rigid fixation) to 0.9 (90% reduction in stiffness relative to the rigid fixation) after 1, 2, 3, and 4 weeks of osteotomy (R1wF, R2wF, R3wF, and R4wF) and computationally evaluated bone regeneration and biomechanical integrity over the healing process of 8 weeks. Compared with the constant rigid fixation, early dynamization (R1wF and R2wF) led to delays in bone bridging and biomechanical recovery of the osteotomized bone. However, the effect of early dynamization on healing was dependent of the degree of dynamization. Specifically, a higher dynamization degree (e.g., 0.9 for R1wF) led to a prolonged delay in bone bridging and largely unrecovered bending stiffness (48% relative to the intact bone), whereas a moderate degree of dynamization (e.g., 0.5 or 0.7) significantly enhanced bone formation and biomechanical properties of the osteotomized bone. These results suggest that dynamization degree and timing interactively affect the healing process. A combination of early dynamization with a moderate degree could enhance the ultimate biomechanical recovery of the fractured bone.

Collagen X Longitudinal Fracture Biomarker Suggests Staged Fixation in Tibial Plateau Fractures Delays Rate of Endochondral Repair

OBJECTIVES

To use a novel, validated bioassay to monitor serum concentrations of a breakdown product of collagen X in a prospective longitudinal study of patients sustaining isolated tibial plateau fractures. Collagen X is the hallmark extracellular matrix protein present during conversion of soft, cartilaginous callus to bone during endochondral repair. Previous preclinical and clinical studies demonstrated a distinct peak in collagen X biomarker (CXM) bioassay levels after long bone fractures.

SETTING

Level 1 academic trauma facility.

PATIENTS/PARTICIPANTS

Thirty-six patients; isolated tibial plateau fractures.

INTERVENTION

(3) Closed treatment, ex-fix (temporizing/definitive), and open reduction internal fixation.

MAIN OUTCOME MEASUREMENTS

Collagen X serum biomarker levels (CXM bioassay).

RESULTS

Twenty-two men and 14 women (average age: 46.3 y; 22.6-73.4, SD 13.3) enrolled (16 unicondylar and 20 bicondylar fractures). Twenty-five patients (72.2%) were treated operatively, including 12 (33.3%) provisionally or definitively treated by ex-fix. No difference was found in peak CXM values between sexes or age. Patients demonstrated peak expression near 1000 pg/mL (average: male-986.5 pg/mL, SD 369; female-953.2 pg/mL, SD 576). There was no difference in peak CXM by treatment protocol, external fixator use, or fracture severity (Schatzker). Patients treated with external fixation (P = 0.05) or staged open reduction internal fixation (P = 0.046) critically demonstrated delayed peaks.

CONCLUSIONS

Pilot analysis demonstrates a strong CXM peak after fractures commensurate with previous preclinical and clinical studies, which was delayed with staged fixation. This may represent the consequence of delayed construct loading. Further validation requires larger cohorts and long-term follow-up. Collagen X may provide an opportunity to support prospective interventional studies testing novel orthobiologics or fixation techniques.

LEVEL OF EVIDENCE

Level II, prospective clinical observational study.

A Review of Proximal Tibia Entry Points for Intramedullary Nailing and Validation of The Lateral Parapatellar Approach as Extra-articular

Tibial shaft fractures are the most common long bone injury and are often treated surgically in an attempt to minimize complications. Although treatment options for tibial shaft fractures vary based on factors including open injury, severity of fracture, and soft tissue status, intramedullary nailing in adults has emerged as the preferred definitive option for stabilization. Therefore, the primary purposes of this review and cadaveric study were to evaluate the entry points for reamed tibial nails and the risks, benefits, and advantages of each approach. Due to concerns of violating the joint capsule and the generalized applicability to everyday practice of the extra-articular lateral parapatellar semi-extended technique, the secondary goal of this manuscript was to evaluate whether an intramedullary tibial nail can be consistently placed extra-articularly using the lateral parapatellar technique described by Kubiak et al. and generalizability to surgeons of varying experience.

Addition of shock wave therapy to nail dynamization increases the chance of long-bone non-union healing

Background

Long-bone non-unions after intramedullary nailing can be treated by nail dynamization or focused high-energy extracorporal shock wave therapy (fESWT). The objective of this study was to assess the effect of the combination therapy of nail dynamization and fESWT on long-bone non-unions.

Materials and methods

49 patients with long-bone non-unions (femur and tibia) after nailing were treated with nail dynamization (group D, n = 15), fESWT (group S, n = 17) or nail dynamization in addition to fESWT (group DS, n = 17). Patients were followed up for 6 months retrospectively. Furthermore, age, sex, Non-Union Scoring System (NUSS) score, time intervals from primary and last surgery until intervention and smoking status were analysed for their correlations to bone union.

Results

Union rates were 60% for group D, 64.7% for group S and 88.2% for group DS, with a significant difference between group D and DS (p = 0.024). Successful treatment was correlated with high age (OR 1.131; 95% CI 1.009–1.268; p = 0.034), female gender (OR 0.009; 95% CI 0.000–0.89; p = 0.039), low NUSS score (OR 0.839; 95% CI 0.717–0.081; p = 0.028) and negative smoking status (OR 86.018; 95% CI 3.051–2425.038; p = 0.009).

Conclusions

Data from the present study indicate that the combination therapy of nail dynamization and fESWT leads to a higher union rate than dynamization or fESWT alone.

Level of evidence

Level 3.

Effectiveness of Nail Dynamization in Delayed Union of Tibial Shaft Fractures: Relationship Between Fracture Morphology, Callus Diameter, and Union Rates

OBJECTIVE

Dynamization has already been described as a secondary intervention for delay unions of tibial shaft fractures treated with intramedullary nailing. Although it's a common procedure, it is not widely supported in the literature. The purpose of this study was to determine the union rate of nail dynamization in cases of delayed union of diaphyseal tibial fractures, and assess the effect of fracture morphology on union rates.

MATERIALS AND METHODS

We retrospectively analyzed a series of 199 consecutive tibial shaft fractures. We recorded the dynamization rate, period from nailing to dynamization, nailing to the union, the fracture pattern (according to AO/ASIF and whether it was closed or open), the callus diameter before dynamization (fracture healing index; FHI) and union/failure rates.

RESULTS

Out of a total of 199 fractures treated during the study period, 41 (20.6%) were dynamized. After applying inclusion and exclusion criteria, 39 patients with 39 fractures were included in the study. The mean time from nailing to dynamization was 18.4 ± 7.2 weeks. The union rate was 92.3% (n = 36) over a mean time of 14.1 ± 5.6 weeks as from dynamization. The overall failure rate was 6.7% (n = 3). There was no significant association between failure and AO/ASIF classification (p > 0.05) or fracture exposure (X ² = 0.19; p = 0.66). The pre-dynamization FHI of ≥ 1.17 was significantly associated with consolidation (p < 0.05).

CONCLUSION

In cases of delayed union of tibial fractures, dynamization offered a high union rate associated with pre-dynamization FHI, while fracture morphology did not affect the failure rate.

Functional and Radiological Outcome Analysis of Osteoperiosteal Decortication Flap in Nonunion of Tibia

Introduction

The treatment of long bone shaft nonunions is challenging. The technique of osteoperiosteal decortications flap for approaching the nonunion site coupled with fixation modalities was first described by Judet in 1963. Despite promising clinical and radiological union, this technique is not popular among orthopaedic surgeons. Our study aimed to evaluate the radiological union and functional results of shaft tibia nonunions treated by the osteoperiosteal decortication approach.

Methods

This retrospective study included all the cases with established tibial shaft nonunion following stringent inclusion and exclusion criteria and operated upon by following the principle of osteoperiosteal flap technique from April 2015 to July 2019. Further subgroups were made based on nonunions complexity based on nonunion scoring system (NUSS) score. The outcome measures included radiological union scale in tibial fractures (RUST) and lower extremity functional scale (LEFS). The preoperative scores for union and function were recorded, and the subsequent scores were obtained at three, six, and nine months and one year. Appropriate statistical analysis of the data was done.

Results

Thirty-four cases were shortlisted for analysis, fulfilling our inclusion and exclusion criteria. There were 22 males (64.7%) and 12 females (35.3%) with a mean age of 34.17 ± 10.3 years. Subgroup analysis based on the complexity of nonunion (NUSS score) revealed 14 cases in group A, 10 cases in group B, 10 cases in group C, and 0 cases in group D. The average time from fracture to surgery in these cases was 14.6 months. The average time to achieve union was 9.6 months, with patients in groups A, B, and C, having a mean duration of 9, 10.5, and 12 months, respectively. Statistically, significant improvement was seen in both RUST scores and LEFS score. Complications included infection in seven cases, wound dehiscence in two cases, and four cases of persistent nonunion.

Conclusion

Osteoperiosteal decortication remains a highly effective surgical technique in the management of nonunion of long bones. NUSS scoring is an essential tool for prognosticating nonunion cases. This score is inversely related to the radiological union (RUST score) of the bone and functional recovery (LEFS score) of the patient.

Poller blocking screw augmentation to treat delayed union of proximal tibial shaft fracture after locked IM nailing

CASES

We present the cases of two adult male patients with painfully delayed union of proximal tibia diaphyseal fracture after intramedullary nailing. Patients underwent to nail dynamization and Poller blocking screw augmentation at 3 and 5 month, respectively, after the index surgery. Both patients were pain-free after the surgery and bone-union were radiographically evident after 3 months. At 12-month follow-up, patients returned to their previous activities.

CONCLUSIONS

Although nail dynamization is the choice treatment to obtain fracture compression for delayed union of tibial shaft fractures, augmentation with Poller blocking screw could provide additional mechanical stiffness in unstable supra-isthmic shaft fractures of the tibia and favour bone union.

Treatment options for aseptic tibial diaphyseal nonunion: A review of selected studies

In aseptic tibial diaphyseal nonunions after failed conservative treatment, the recommended treatment is a reamed intramedullary (IM) nail.Typically, when an aseptic tibial nonunion previously treated with an IM nail is found, it is advisable to change the previous IM nail for a larger diameter reamed and locked IM nail (the rate of success of renailing is around 90%).A second change after an IM nail failure is also a good option, especially if bone healing has progressed after the first change.Fibular osteotomy is not routinely advised; it is only recommended when it interferes with the nonunion site.In delayed unions before 24 weeks, IM nail dynamization can be performed as a less invasive option before deciding on a nail change.If there is a bone defect, a bone graft must be recommended, with the gold standard being the autologous iliac crest bone graft (AICBG).A reamer-irrigator-aspirator (RIA) system might also obtain a bone autograft that is comparable to AICBG.Although the size of the bone defect suitable to perform bone transport techniques is a controversial issue, we believe that such techniques can be considered in bone defects > 3 cm.Non-invasive therapies and biologic therapies could be applied in isolation for patients with high surgical risk, or could be used as adjuvants to the aforementioned surgical treatments. Cite this article: EFORT Open Rev 2020;5:835-844. DOI: 10.1302/2058-5241.5.190077.

The biology and treatment of acute long-bones diaphyseal fractures: Overview of the current options for bone healing enhancement

Diaphyseal fractures represent a complex biological entity that could often end into impaired bone-healing, with delayed union and non-union occurring up to 10% of cases. The role of the modern orthopaedic surgeon is to optimize the fracture healing environment, recognize and eliminate possible interfering factors, and choose the best suited surgical fixation technique. The impaired reparative process after surgical intervention can be modulated with different surgical techniques, such as dynamization or exchange nailing after failed intramedullary nailing. Moreover, the mechanical stability of a nail can be improved through augmentation plating, bone grafting or external fixation techniques with satisfactory results. According to the "diamond concept", local therapies, such as osteoconductive scaffolds, bone growth factors, and osteogenic cells can be successfully applied in "polytherapy" for the enhancement of delayed union and non-union of long bones diaphyseal fractures. Moreover, systemic anti-osteoporosis anabolic drugs, such as teriparatide, have been proposed as off-label treatment for bone healing enhancement both in fresh complex shaft fractures and impaired unions, especially for fragility fractures. The article aims to review the biological and mechanical principles of failed reparative osteogenesis of diaphyseal fractures after surgical treatment. Moreover, the evidence about the modern non-surgical and pharmacological options for bone healing enhancement will discussed.

Controversies in Fracture Healing: Early Versus Late Dynamization

Dynamization of fracture fixation constructs provides early rigidity for primary bone healing and late motion for secondary healing. A review of laboratory, animal, and clinical studies investigating the impact, and optimal timing, of dynamization is limited by lack of standardization across studies. However, in animal models, dynamization improves histologic and biomechanical properties compared with statically rigid or flexible controls. In animals, dynamization at 3 to 4 weeks showed improved histologic results. In clinical studies, it showed faster, stronger, and stiffer bone healing. Clinical success dynamizing external fixators and intramedullary nails suggests a role for late dynamization in other fixation types, such as bridge plating. [Orthopedics. 2020;43(3):e125-e133.].

Nonunion - consensus from the 4th annual meeting of the Danish Orthopaedic Trauma Society

Nonunions are a relevant economic burden affecting about 1.9% of all fractures. Rather than specifying a certain time frame, a nonunion is better defined as a fracture that will not heal without further intervention.

Successful fracture healing depends on local biology, biomechanics and a variety of systemic factors. All components can principally be decisive and determine the classification of atrophic, oligotrophic or hypertrophic nonunions. Treatment prioritizes mechanics before biology.

The degree of motion between fracture parts is the key for healing and is described by strain theory. If the change of length at a given load is > 10%, fibrous tissue and not bone is formed. Therefore, simple fractures require absolute and complex fractures relative stability.

The main characteristics of a nonunion are pain while weight bearing, and persistent fracture lines on X-ray.

Treatment concepts such as ‘mechanobiology’ or the ‘diamond concept’ determine the applied osteosynthesis considering soft tissue, local biology and stability. Fine wire circular external fixation is considered the only form of true biologic fixation due to its ability to eliminate parasitic motions while maintaining load-dependent axial stiffness. Nailing provides intramedullary stability and biology via reaming. Plates are successful when complex fractures turn into simple nonunions demanding absolute stability. Despite available alternatives, autograft is the gold standard for providing osteoinductive and osteoconductive stimuli.

The infected nonunion remains a challenge. Bacteria, especially staphylococcus species, have developed mechanisms to survive such as biofilm formation, inactive forms and internalization. Therefore, radical debridement and specific antibiotics are necessary prior to reconstruction.

Cite this article: EFORT Open Rev 2020;5:46-57. DOI: 10.1302/2058-5241.5.190037

The PRECICE magnetic IM compression nail for long bone nonunions: a preliminary report

INTRODUCTION

The magnetic intramedullary (IM) compression nail is capable of providing sustained compression for the treatment of nonunions of long bones. This ability was previously only possible with the use of external fixation. We asked the following questions: How effective is the IM compression nail at achieving union? How do we know when adequate compression has been attained? Which types of nonunions are good candidates for this treatment?

MATERIALS AND METHODS

Fourteen patients with nonunions of the tibia (5) or femur (9) were treated with the PRECICE IM compression nail. The average age was 49 years number of previous surgeries was 1.9, 7 were atrophic and 7 normotrophic, 3 were metaphyseal and 11 diaphyseal. All PRECICE IM nails were pre-distracted prior to implantation. Compression was applied post-operatively until the locking bolts were seen on X-ray to be bending or the nail was no longer shortening despite applying the external magnet.

RESULTS

Union was achieved in 13/14 cases. The time to union was 24.5 weeks (range 11-60). The two proximal tibia metaphyseal nonunions, both deformed into varus (4°) and flexion (10°) after compression was applied with one failing to unite. The distal tibia metaphyseal and diaphyseal nonunions did not deform upon compression. Three patients had positive cultures and were treated with IV antibiotics for 6 weeks followed by 3 months of oral suppression without subsequent infection. No mechanical nail failures were seen.

CONCLUSIONS

The IM compression nail was successful at applying compression, preventing deformity, and obtaining union in all diaphyseal and in distal tibia metaphyseal nonunions. Signs of active compression are bending of the locking bolts and failure of the nail to shorten. Proximal tibia metaphyseal nonunion may not be suited for this treatment.

Clinical outcomes of femoral shaft non-union: dual plating versus exchange nailing with augmentation plating

Background

By comparing clinical outcomes between dual plating (DP) and exchange nailing with augmentation plating (EN/AP), we aimed to provide better treatment strategies for femoral shaft non-union.

Methods

We retrospectively reviewed 30 patients with aseptic femoral shaft non-union at our level 1 trauma center between January 2014 and January 2017. All patients underwent a one-stage, definitive revision procedure, including DP for 16 patients and EN/AP for 14 patients. Perioperative surgical trauma, fracture healing, complications, and the time to return to work were evaluated.

Results

Twenty-nine patients achieved fracture healing. In the EN/AP group, the fracture healing rate was 100%, the healing time was 5.7 ± 1.7 months, and the time of return to work was 8.2 ± 2.9 months. In the DP group, the fracture healing rate was 94%, the healing time was 8.4 ± 4.1 months, and the time of return to work was 18.4 ± 10.3 months. In terms of fracture healing and return to work, the patients in the EN/AP group required less time than those in the DP group, and the differences were statistically significant (p = 0.024 and p < 0.01 respectively). Except for the length of the incision, the two groups showed no statistically significant differences in operative time, postoperative deformity, and complications.

Conclusions

Both EN/AP and DP are important surgical options for femoral shaft non-union. Compared to DP, EN/AP resulted in a shorter incision, faster fracture healing, and a shorter time to return to work.

Trial registration

ChiCTR-ORC-17014062

Load-sharing through elastic micro-motion accelerates bone formation and interbody fusion

BACKGROUND CONTEXT

Achieving a successful spinal fusion requires the proper biological and biomechanical environment. Optimizing load-sharing in the interbody space can enhance bone formation. For anterior cervical discectomy and fusion (ACDF), loading and motion are largely dictated by the stiffness of the plate, which can facilitate a balance between stability and load-sharing. The advantages of load-sharing may be substantial for patients with comorbidities and in multilevel procedures where pseudarthrosis rates are significant.

PURPOSE

We aimed to evaluate the efficacy of a novel elastically deformable, continuously load-sharing anterior cervical spinal plate for promotion of bone formation and interbody fusion relative to a translationally dynamic plate.

STUDY DESIGN/SETTING

An in vivo animal model was used to evaluate the effects of an elastically deformable spinal plate on bone formation and spine fusion.

METHODS

Fourteen goats underwent an ACDF and received either a translationally dynamic or elastically deformable plate. Animals were followed up until 18 weeks and were evaluated by plain x-ray, computed tomography scan, and undecalcified histology to evaluate the rate and quality of bone formation and interbody fusion.

RESULTS

Animals treated with the elastically deformable plate demonstrated statistically significantly superior early bone formation relative to the translationally dynamic plate. Trends in the data from 8 to 18 weeks postoperatively suggest that the elastically deformable implant enhanced bony bridging and fusion, but these enhancements were not statistically significant.

CONCLUSIONS

Load-sharing through elastic micro-motion accelerates bone formation in the challenging goat ACDF model. The elastically deformable implant used in this study may promote early bony bridging and increased rates of fusion, but future studies will be necessary to comprehensively characterize the advantages of load-sharing through micro-motion.

Tibial Fracture Nonunion and Time to Healing After Reamed Intramedullary Nailing: Risk Factors Based on a Single-Center Review of 1003 Patients

OBJECTIVE

To determine factors associated with nonunion of adult tibial fractures.

DESIGN

Retrospective review with data collection for logistic regression and survival analysis.

SETTING

Scottish Level I trauma center, 1985-2007.

PATIENTS

During this period, 1590 adult tibial fractures were treated by reamed nailing and 1003 fractures met all inclusion criteria for the chosen analysis.

INTERVENTION

Reamed intramedullary nailing.

MAIN OUTCOME MEASURES

Record of nonunion diagnosis and final union time with characteristics, including age, gender, closed or open injury, OTA/AO classification, Gustilo classification, fasciotomy, infection, polytrauma, smoking, and injury severity score.

RESULTS

The overall nonunion rate was 12%, and median time to healing was 18 weeks. Age significantly influenced nonunion, with middle-aged patients at highest risk. Both fracture type (closed/open) and morphology (OTA/AO classification) significantly influenced nonunion risk and time to union. Among closed injuries, the highest nonunion rate was for OTA/AO type B fractures (15%). Among open injuries, the highest nonunion rate was for OTA/AO type C (61%). Both compartment syndrome and smoking did not significantly influence nonunion risk but did significantly extend time to union.

CONCLUSIONS

Injury characteristics including fracture morphology and severity of soft tissue injury were strong predictors of compromised fracture healing. Age also influenced nonunion risk in an unexpected way, with highest rates in the middle decades of adulthood. Future studies should consider the possibility of similar age-related effects and clinical studies should seek to identify explanations for why this may arise, including both physiological and socio-behavioral factors.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Distal femur: dynamization of plating

With advances in osteosynthesis technology providing improved stability of fixation and better outcomes, surgical treatment has become the standard of care for distal femur fractures. Pre-contoured distal femoral locking plates are the most commonly used implants for fixation. However, healing problems such as delayed union, failure of fixation, and /or nonunion are not uncommon. The fixation construct being "too stiff" is a commonly quoted reason when nonunion/failure of fixation occurs on distal femur fractures fixed with a plate. A flexible fixation construct allowing controlled axial micromotion could help stimulate the bone healing. In order to achieve this goal, plating construct stiffness can be modified by several methods.

[Recent advances in treatment of aseptic femoral shaft nonunion]

Objective

To review the recent advances in treatment of aseptic femoral shaft nonunion.

Methods

The clinical studies about the treatments of aseptic femoral shaft nonunion in recent years were widely reviewed and analyzed.

Results

There are several surgical methods for aseptic femoral shaft nonunion. Due to uncertain clinical outcome, dynamization of nail should be carefully selected. The exchange nailing is suitable for the hypertrophic nonunion of the isthmal femoral shaft fracture. The exchange lateral plating is suitable for nonunion with obvious malformation. However, wave plate or dual plate should be chosen when the bone nonuinon is combined with the medial defect. The augmentation plating improves the success rate of nailing for femoral shaft nonunion, but it should be carefully selected for patients with obvious deformity or bone defect. Ilizarov technique is suitable for various bone nonunion, especially with complicated or large segmental bone defects. Induced membrane technique is also an important method for the treatment of bone nonunion with large bone defects. The clinical efficacy of the blocking screw remains to be supported by further evidence. Biological stimulants are mainly used for atrophic nonunion, and the clinical efficacy of them alone are still controversial.

Conclusion

Due to lack of comparative studies between different surgical methods, the orthopedist should choose the appropriate treatment according to the individual situations of the patient and the types of bone nonunion.

Diaphyseal long bone nonunions - types, aetiology, economics, and treatment recommendations

The intention of the current article is to review the epidemiology with related socioeconomic costs, pathophysiology, and treatment options for diaphyseal long bone delayed unions and nonunions. Diaphyseal nonunions in the tibia and in the femur are estimated to occur 4.6-8% after modern intramedullary nailing of closed fractures with an even much higher risk in open fractures. There is a high socioeconomic burden for long bone nonunions mainly driven by indirect costs, such as productivity losses due to long treatment duration. The classic classification of Weber and Cech of the 1970s is based on the underlying biological aspect of the nonunion differentiating between "vital" (hypertrophic) and "avital" (hypo-/atrophic) nonunions, and can still be considered to represent the basis for basic evaluation of nonunions. The "diamond concept" units biomechanical and biological aspects and provides the pre-requisites for successful bone healing in nonunions. For humeral diaphyseal shaft nonunions, excellent results for augmentation plating were reported. In atrophic humeral shaft nonunions, compression plating with stimulation of bone healing by bone grafting or BMPs seem to be the best option. For femoral and tibial diaphyseal shaft fractures, dynamization of the nail is an atraumatic, effective, and cheap surgical possibility to achieve bony consolidation, particularly in delayed nonunions before 24 weeks after initial surgery. In established hypertrophic nonunions in the tibia and femur, biomechanical stability should be addressed by augmentation plating or exchange nailing. Hypotrophic or atrophic nonunions require additional biological stimulation of bone healing for augmentation plating.

Minimally invasive plate augmentation in the treatment of long-bone non-unions

INTRODUCTION

Exchange nailing is most acceptable for treating hypertrophic non-union of the long bones, requiring the removal of previously fixed implant. However, its main effect of mechanical stabilization is controversial in non-isthmal area. We hypothesized that minimally invasive plate augmentation over the non-union site may have a better option, without the need of bone grafting or removing pre-existing implants.

MATERIALS AND METHODS

Seventeen patients with hypertrophic non-union of the long bones between 2010 and 2014 on radiography who previously underwent intramedullary (IM) nailing or plate osteosynthesis for long-bone fractures were included. A locking compression plate was inserted with at least three mono- or bicortical screws at each proximal and distal segment. Broken or loosened interlocking screws of IM nail were simultaneously re-fixed. Fracture site exposure, pre-fixed implant removal, and bone grafting were not performed. We investigated whether union occurred and analyzed functional outcomes and complications.

RESULTS

Eleven femoral and six tibial non-unions were prospectively included. In the pre-existing implants, 13 nails and 4 plates were found. All cases achieved union at a mean 22.7 weeks. One case of superficial infection was managed with oral antibiotics. Deep infection or implant failure did not occur.

CONCLUSIONS

Minimally invasive plate augmentation can achieve additional stability and promote healing of hypertrophic non-union of the long bones. When indicated, this technique is the least invasive alternative to exchange nailing and reduces surgical risks in the treatment of diaphyseal non-union.

Role of Bone Marrow Aspirate in Orthopedic Trauma

Bone marrow aspirate grafting entails mesenchymal stem cell-containing bone marrow harvesting and injection into a fracture site to promote bone formation. Although the use of bone marrow aspirate in orthopedic trauma is not widespread, an increasing number of studies are reporting clinical success. Advantages of using bone marrow aspirate are that it is readily obtainable, has low harvest morbidity, and can be easily and quickly injected. However, no universally accepted role for its use exists. Future studies directly comparing bone marrow aspirate with conventional techniques are needed to define its role in the treatment of orthopedic trauma patients.

Treatment of aseptic non-union after intramedullary nailing without removal of the nail

Failure of bone healing after intramedullary nailing of a diaphyseal long bone fracture is a severe complication that requires an effective management to ensure the best chances for successful bone-union and termination of a long period of incapacity and morbidity for the sufferers. Traditional procedures require removal of the existing nail and re-fixation with wider nail, plate or external fixation constructs. The concept that bone union can be obtained with the existing nail in situ is gaining popularity as its removal adds trauma and potential complications and prolongs the operating time. This article reviews all techniques that have been proposed for the management of aseptic diaphyseal long bone non-unions that stimulate bone healing without removing the existing nail.

Comparison of intramedullary nail, plate, and external fixation in the treatment of distal tibia nonunions

PURPOSE

The purpose of this study was to examine time to union of extra-articular distal tibia nonunions based on fracture type and fixation methods: intramedullary nail (IMN), plate osteosynthesis (PO), and external fixation (EF).

METHODS

This retrospective chart review included all patients who presented at a Level I trauma center with AO/OTA 43A & distal third 42A-C fracture nonunions between 2008 and 2014. Fixation methods were recorded and patient course was followed until nonunion had healed clinically.

RESULTS

Thirty-three distal tibia nonunions were included, and 29 reached eventual union (88%). Five AO/OTA fracture types were present. Mean times to union from nonunion diagnosis between original fracture types were compared (p = 0.203). Comminuted fracture types had longer times to union from nonunion diagnosis compared to simple fracture types (78 vs. 46 weeks, p = 0.051) and more revision fixations (1.5 vs. 0.5, p = 0.037). Mean time to union from nonunion diagnosis was shorter when no revision fixation was done compared to revisions (15 vs. 42 weeks, p = 0.102). Times to union from nonunion diagnosis without revision fixation were: IMN (12 weeks), PO (27 weeks), and EF (13 weeks) (p = 0.202). Times to union from definitive revision fixation were: IMN (17 weeks), PO (21 weeks), and EF (66 weeks) (p = 0.009), with EF taking significantly longer than both other methods. 21 patients (64%) underwent revision fixation. Revision fail rates were: IMN (0/6, 0%), PO (2/8, 25%), and EF (15/21, 71%). Time to union was longer in revisions that changed fixation method compared to revisions that used the same method (51 vs. 18 weeks, p = 0.030). Deep infections were also associated with longer union times (81 vs. 47 weeks, p = 0.040).

CONCLUSIONS

In this nonunion population, comminuted fracture types needed more time and revisions to reach union. Time to union was only clinically shorter when revision fixation was not performed, but IMN and PO were both successful fixation options with significantly shorter times to union than EF. Mean time to union increased even more when revision of fixation method was performed vs. exchange revision, as did nonunions with deep infections.

Nonunion of the Femur and Tibia: An Update

Delayed union and nonunion of tibial and femoral shaft fractures are common orthopedic problems. Numerous publications address lower extremity long bone nonunions. This review presents current trends and recent literature on the evaluation and treatment of nonunions of the tibia and femur. New studies focused on tibial nonunion and femoral nonunion are reviewed. A section summarizing recent treatment of atypical femoral fractures associated with bisphosphonate therapy is also included.