The radiographic union scale in tibial (RUST) fractures: Reliability of the outcome measure at an independent centre

Patient-Reported Outcome Measurement Information Systems Physical Function and Pain Interference Scores Are Correlated With Tibial Shaft Fracture Nonunion Following Intramedullary Nailing

OBJECTIVES

To assess trends in Patient-Reported Outcome Measurement Information Systems (PROMIS) Physical Function (PF) and Pain Interference (PI) in surgically treated tibial shaft fracture patients progressing to union versus nonunion.

METHODS

DESIGN

Retrospective cohort study.

SETTING

Level 1 trauma center.

PATIENT SELECTION CRITERIA

Patients with operatively treated tibial shaft fractures (AO/OTA 42-A, B, C) using an intramedullary nail.

OUTCOME MEASURES AND COMPARISONS

PROMIS PF and PI were compared between patients progressing to union and patients requiring nonunion repair.

RESULTS

A total of 234 patients (196 union, 38 nonunion) were included consisting 144 men and 90 women. The mean age of included patients was 40.8 years. A significant difference in mean PROMIS PF between union and nonunion patients was observed at 1-3 months ( P = 0.005), 3-6 months ( P < 0.001), 6-9 months ( P = 0.003), and 6-12 months ( P = 0.018). The odds of developing nonunion for every unit decrease in PROMIS PF was significant at 3-6 months (OR 1.07, P = 0.028) and 6-9 months (OR 1.17, P = 0.015). A significant difference in mean PROMIS PI between union and nonunion patients was observed at 1-3 months ( P = 0.001), 3-6 months ( P = 0.005), and 6-9 months ( P = 0.005). The odds of developing nonunion for every unit increase in PROMIS PI was significant at 1-3 months (OR 1.11, P = 0.005), 3-6 months (OR 1.10, P = 0.011), and 6-9 months (OR 1.23, P = 0.011).

CONCLUSIONS

Poorly trending PROMIS PF and PI in the clinical setting is a factor that can be used to evaluate progression to nonunion following tibial shaft repair where imaging studies may lag behind.

LEVEL OF EVIDENCE

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

In Vivo Investigation of 3D-Printed Calcium Magnesium Phosphate Wedges in Partial Load Defects

Bone substitutes are ideally biocompatible, osteoconductive, degradable and defect-specific and provide mechanical stability. Magnesium phosphate cements (MPCs) offer high initial stability and faster degradation compared to the well-researched calcium phosphate cements (CPCs). Calcium magnesium phosphate cements (CMPCs) should combine the properties of both and have so far shown promising results. The present study aimed to investigate and compare the degradation and osseointegration behavior of 3D powder-printed wedges of CMPC and MPC in vivo. The wedges were post-treated with phosphoric acid (CMPC) and diammonium hydrogen phosphate (MPC) and implanted in a partially loaded defect model in the proximal rabbit tibia. The evaluation included clinical, in vivo µ-CT and X-ray examinations, histology, energy dispersive X-ray analysis (EDX) and scanning electron microscopy (SEM) for up to 30 weeks. SEM analysis revealed a zone of unreacted material in the MPC, indicating the need to optimize the manufacturing and post-treatment process. However, all materials showed excellent biocompatibility and mechanical stability. After 24 weeks, they were almost completely degraded. The slower degradation rate of the CMPC corresponded more favorably to the bone growth rate compared to the MPC. Due to the promising results of the CMPC in this study, it should be further investigated, for example in defect models with higher load.

Treatment of non-hypertrophic pseudoarthrosis of long bones with a Tissue Engineered Product loaded with autologous bone marrow-derived Mesenchymal Stromal Cells: Results from a phase IIa, prospective, randomized, parallel, pilot clinical trial comparing to iliac crest autograft

BACKGROUND

Atrophic pseudoarthrosis is a serious complication with an incidence of 5-10 % of bone fractures located in the diaphysis of long bones. Standard treatments involve aggressive surgical procedures and re-interventions requiring the use of autografts from the iliac crest as a source of bone-forming biological activity (Standard of Care, SoC). In this context, regenerative ex vivo expanded osteogenic cell-based medicines could be of interest. Particularly, Mesenchymal Stromal Cells (MSC) offer new prospects to promote bone tissue repair in pseudoarthrosis by providing biological activity in an osteoconductive and osteoinductive environment.

METHODS

We conducted a phase IIa, prospective, randomised, parallel, two-arms, open-label with blinded assessor pilot clinical trial to compare SoC vs. a tissue-engineered product (TEP), composed of autologous bone marrow (BM)-derived MSCs loaded onto allogeneic decellularised, lyophilised spongy bone cubes, in a cohort of 20 patients with non-hypertrophic pseudoarthrosis of long bones. Patients were followed up for 12 months. Radiological bone healing was evaluated by standard X-ray and computed tomography (CT) scanning. Quality of life was measured using the EUROQOL-5D questionnaire.

RESULTS

Ten patients were randomized to TEP and 10 to SoC with iliac crest autograft. Manufacturing of TEP was feasible and reproducibly achieved. TEP implantation in the bone defect was successful in all cases and none of the 36 adverse events (AE) reported were related to the treatment. Efficacy analyses were performed in the Full Analysis Set (FAS) population, which included 17 patients after 3 patients withdrew from the study. The degree of consolidation, estimated by measuring Hounsfield units (HU) on CT, showed no significant differences between the two treatment groups at 12 months post treatment (main efficacy variable) (p = 0.4835) or at 6 months.

CONCLUSIONS

Although only a small number of patients were included in our study, it is notable that no significant differences were observed between the experimental treatment and SoC, thus suggesting TEP as an alternative where autograft is not available or contraindicated.

Bone union and mobility outcomes for reconstructed open tibial fractures: a plastic surgical experience from a major trauma center

Introduction

The goal in open tibial fracture management is to achieve a united tibia in an extremity that allows pain free mobilization. The objective of this study was to assess factors that lead to this functional outcome in lower limb reconstruction, from a plastic surgical perspective.

Materials and methods

The Plastic and Reconstructive Surgery lower limb database at a tertiary trauma hospital was searched for open tibial injuries from February 2015 to March 2020. The nature and severity of injury, timing and details of all operations including reconstructions were collected prospectively. Mobility including gait aids, pain, and complications were retrospectively collected. Union was assessed in two ways, depending on fracture location. Metaphyseal and diaphyseal tibial fractures were provided mRUST scores (union defined as RUST > 13) and epiphyseal tibial fractures were categorically classified as "united" or "non-union" by two independent radiologists.

Results

During the five-year study period there were 148 open leg injuries in the database. Twenty-one patients underwent a primary amputation due to severity of their initial injury. One hundred patients underwent primary limb salvage. Sixty-one patients in the limb salvage group achieved primary tibial union with a mean follow-up time of 19.4 months post injury. Twenty-three additional patients were confirmed to subsequently unite. Patient who achieved union were more likely to mobilise without gait aids.

Discussion

In this study definitive external fixation and soft tissue infection were both associated with higher rates of non-union. Longer times to soft tissue reconstruction was not associated with an increase in acute soft tissue complications. More importantly bone union, pain and mobility did not decline. After undertaking a primary limb salvage pathway for 100 patients, the ultimate tibial fracture union rate was 84% and the confirmed ambulation rate was 96%.

The value of ultrasonography in predicting the outcomes of simple long bone fractures treated by closed intramedullary nail fixation

PURPOSE

Ultrasonography has been used increasingly in orthopaedic practice credited to its low cost, easy accessibility, non-invasiveness, reproducibility, and safety from radiation. The purpose of this study was to test the validity and efficacy of ultrasonography as an adjunct in the assessment of fracture healing in long bones treated with intramedullary interlocking devices and its predictive value in determining the need for a secondary surgical procedure.

METHODS

This was a descriptive longitudinal study of 40 skeletally mature patients who sustained long bone fractures of the tibia or femur treated using intramedullary interlocking nails. Patients with comminuted and segmental fracture patterns were excluded from the study. Each patient was evaluated at 6- and 12-week post-surgery using standard orthogonal radiographs and ultrasonography to assess fracture healing. Patients were then followed up until fracture union. Quantitative data was analyzed using frequency statistics and descriptive data with inferential statistics.

RESULTS

Ultrasonography predicted 87.5% union and 12.5% delayed or non-union as early as 6 weeks after surgery, while radiographs predicted 22.5% union as late as 3 months of follow-up. The sensitivity and specificity of ultrasonography in assessing fracture healing were 100% and 97.2%, respectively, with a positive predictive value of 80.0%. Vascular resistance index was less than 0.5 in all patients who developed delayed or non-union.

CONCLUSION

Ultrasonography is able to predict fracture outcomes much earlier than standardized radiographs with comparable sensitivity and specificity. Vascular resistance index is an objective parameter in assessing callus quality and predicting fracture outcomes.

Intramedullary Fixation for Pediatric Femoral Nonunion in Low- and Middle-Income Countries

BACKGROUND

Pediatric femoral shaft nonunion after use of a plate or intramedullary nail (IMN) is uncommon in the United States. In low and middle-income countries, as defined by The World Bank, these complications may occur with greater frequency. We assessed the rates of union and painless weight-bearing after IMN fixation of pediatric femoral shaft nonunion in lower-resource settings.

METHODS

We queried the SIGN (Surgical Implant Generation Network) Fracture Care International online database to identify all pediatric femoral shaft nonunions that had occurred since 2003 and had ≥3 months of follow-up after their treatment; our query identified 85 fractures in 83 patients. We defined nonunion as failure of initial instrumentation >90 days following its placement, lack of radiographic progression on radiographs made >3 months apart, or the absence of signs of radiographic healing >6 months after initial instrumentation. We evaluated the most recent follow-up radiograph to determine a Radiographic Union Scale in Tibial fractures (RUST) score. We also recorded rates of painless full weight-bearing as assessed by the treating surgeon.

RESULTS

Fifty-seven patients with pediatric femoral shaft nonunions (including 42 male and 15 female patients from 18 countries) were included. The average age (and standard deviation) at the time of revision surgery was 13.8 ± 3.0 years (range, 6 to 17 years). The median duration of follow-up was 67 weeks (range, 13 weeks to 7.7 years). The initial instrumentation that went on to implant failure included plate constructs (56%), non-SIGN IMNs (40%), and SIGN IMNs (4%). At the time of the latest follow-up, 52 patients (91%) had a RUST score of ≥10 and 51 (89%) had painless full weight-bearing. No patient had radiographic evidence of femoral head osteonecrosis at the time of complete fracture-healing or the latest follow-up.

CONCLUSIONS

Pediatric femoral shaft nonunion can occur after both plate and IMN fixation in low and middle-income countries. IMN fixation is an effective and safe treatment for these injuries.

LEVEL OF EVIDENCE

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

The Radiographic Union Score for ulnar fractures (RUSU) predicts ulnar shaft nonunion

AIMS

To develop a reliable and effective radiological score to assess the healing of isolated ulnar shaft fractures (IUSF), the Radiographic Union Score for Ulna fractures (RUSU).

METHODS

Initially, 20 patients with radiographs six weeks following a non-operatively managed ulnar shaft fracture were selected and scored by three blinded observers. After intraclass correlation (ICC) analysis, a second group of 54 patients with radiographs six weeks after injury (18 who developed a nonunion and 36 who united) were scored by the same observers.

RESULTS

In the initial study, interobserver and intraobserver ICC were 0.89 and 0.93, respectively. In the validation study, the interobserver ICC was 0.85. The median score for patients who united was significantly higher than those who developed a nonunion (11 vs. 7, p < 0.001). A ROC curve demonstrated that a RUSU ≤ 8 had a sensitivity of 88.9% and specificity of 86.1% in identifying patients at risk of nonunion. Patients with a RUSU ≤ 8 (n = 21) were more likely to develop a nonunion (n = 16/21) than those with a RUSU ≥ 9 (n = 2/33; OR 49.6, 95% CI 8.6-284.7). Based on a PPV of 76%, if all patients with a RUSU ≤ 8 underwent fixation at 6 weeks, the number of procedures needed to avoid one nonunion would be 1.3.

CONCLUSION

The RUSU shows good interobserver and intraobserver reliability and is effective in identifying patients at risk of nonunion six weeks after fracture. This tool requires external validation but may enhance the management of patients with isolated ulnar shaft fractures.

Assessment of Bone Healing: Opportunities to Improve the Standard of Care

➤ Bone healing is commonly evaluated by clinical examination and serial radiographic evaluation. Physicians should be mindful that personal and cultural differences in pain perception may affect the clinical examination. Radiographic assessment, even with the Radiographic Union Score, is qualitative, with limited interobserver agreement.➤ Physicians may use serial clinical and radiographical examinations to assess bone healing in most patients, but in ambiguous and complicated cases, they may require other methods to provide assistance in decision-making.➤ In complicated instances, clinically available biomarkers, ultrasound, and magnetic resonance imaging may determine initial callus development. Quantitative computed tomography and finite element analysis can estimate bone strength in later callus consolidation phases.➤ As a future direction, quantitative rigidity assessments for bone healing may help patients to return to function earlier by increasing a clinician's confidence in successful progressive healing.

Validation of the Radiographic Union Score for HUmeral fractures (RUSHU): A retrospective study in an independent centre

Background

Early diagnosis and fixation of fractures unlikely to unite can prevent months of morbidity. The Radiographic Union Score for Humeral fractures (RUSHU) is a summative scoring system developed to aid identification of patients at higher risk of developing humeral shaft non-union. Plain radiographs taken six weeks after injury are given a score between four and 12 based on signs of union. Our aim was to assess the validity of the RUSHU prognostic model in an external population.

Methods

The radiographs of fifty-seven patients were scored independently according to RUSHU methodology by three reviewers (blinded to patient outcome). Interobserver intraclass correlation (ICC) was calculated.

Results

Of the cohort, six (10.5%) progressed to non-union after six months. We observed an interobserver ICC co-efficient of 0.89 (95%CI0.84,0.93) in RUSHU score at six weeks. Median score was significantly higher in the union cohort (10v5 p < 0.001). Using the score of < 8 to predict non-union gave an area under the ROC curve of 0.87 (95%CI 0.83,0.90).

Conclusions

In this retrospective single-centre study, we have demonstrated good inter-rater reliability. We would suggest that the RUSHU model be assessed in further external validation studies. RUSHU has the potential to reduce morbidity of delayed treatment of non-union.

Open fractures: Current treatment perspective

Severe open fractures present challenges to orthopaedic surgeons worldwide, with increased risks of significant complications. Although different global regions have different resources and systems, there continue to be many consistent approaches to open fracture care. Management of these complex injures continues to evolve in areas ranging from timing of initial operative debridement to the management of critical-sized bone defects. This review, compiled by representative members of the International Orthopaedic Trauma Association, focuses on several critical areas of open fracture management, including antibiotic administration, timing of debridement, bone loss, soft tissue management, and areas of need for future investigation.

Bone Regeneration Using Mesenchymal Stromal Cells and Biocompatible Scaffolds: A Concise Review of the Current Clinical Trials

Bone regenerative medicine is a clinical approach combining live osteoblast progenitors, such as mesenchymal stromal cells (MSCs), with a biocompatible scaffold that can integrate into host bone tissue and restore its structural integrity. Over the last few years, many tissue engineering strategies have been developed and thoroughly investigated; however, limited approaches have been translated to clinical application. Consequently, the development and clinical validation of regenerative approaches remain a centerpiece of investigational efforts towards the clinical translation of advanced bioengineered scaffolds. The aim of this review was to identify the latest clinical trials related to the use of scaffolds with or without MSCs to regenerate bone defects. A revision of the literature was performed in PubMed, Embase, and Clinicaltrials.gov from 2018 up to 2023. Nine clinical trials were analyzed according to the inclusion criteria: six presented in the literature and three reported in Clinicaltrials.gov. Data were extracted covering background trial information. Six of the clinical trials added cells to scaffolds, while three used scaffolds alone. The majority of scaffolds were composed of calcium phosphate ceramic alone, such as β-tricalcium phosphate (TCP) (two clinical trials), biphasic calcium phosphate bioceramic granules (three clinical trials), and anorganic bovine bone (two clinical trials), while bone marrow was the primary source of the MSCs (five clinical trials). The MSC expansion was performed in GMP facilities, using human platelet lysate (PL) as a supplement without osteogenic factors. Only one trial reported minor adverse events. Overall, these findings highlight the importance and efficacy of cell-scaffold constructs in regenerative medicine under different conditions. Despite the encouraging clinical results obtained, further studies are needed to assess their clinical efficacy in treating bone diseases to optimize their application.

Fractures in elderly mice demonstrate delayed ossification of the soft callus: a cellular and radiographic study

OBJECTIVES

The aim of this study was to assess the cellular age-related changes in fracture repair and relate these to the observed radiographic assessments at differing time points.

METHODS

Transverse traumatic tibial diaphyseal fractures were created in 12-14 weeks old (young n = 16) and 18 months old (elderly n = 20) in Balb/C wild mice. Fracture calluses were harvested at five time points from 1 to 35 days post fracture for histomorphometry (percent of cartilage and bone), radiographic analysis (total callus volume, callus index, and relative bone mineral content).

RESULTS

The elderly mice produced an equal amount of cartilage when compared to young mice (p > 0.08). However, by day 21 there was a significantly greater percentage of bone at the fracture site in the young group (mean percentage 50% versus 11%, p < 0.001). It was not until day 35 when the elderly group produced a similar amount of bone compared to the young group at 21 days (50% versus 53%, non-significant (ns)). The callus area and callus index on radiographic assessment was not significantly different between young and elderly groups at any time point. Relative bone mineral content was significantly greater in the young group at 14 days (545.7 versus -120.2, p < 0.001) and 21 days (888.7 versus 451.0, p < 0.001) when compared to the elderly group. It was not until day 35 when the elderly group produced a similar relative bone mineral content as the young group at 21 days (888.7 versus 921.8, ns).

CONCLUSIONS

Elderly mice demonstrated a delay in endochondral ossification which was associated with a decreased relative bone mineral content at the fracture site and may help assess these cellular changes in a clinical setting.

Initial Displacement of Humeral Shaft Fractures Is Associated With Failure of Nonoperative Management

OBJECTIVES

To determine whether the initial radiographic displacement of humeral shaft fractures is associated with failure of nonoperative management.

DESIGN

Retrospective cohort study.

SETTING

Urban level 1 trauma center.

PATIENTS/PARTICIPANTS

106 patients with humeral shaft fractures (OTA/AO 12) initially managed nonoperatively.

INTERVENTION

Functional bracing.

MAIN OUTCOME MEASUREMENTS

Failure of nonoperative management, defined as conversion to surgery, malunion, and delayed union/nonunion.

RESULTS

Nonoperative management failed in 33 (31%) of 106 included patients with 27 patients (25%) requiring surgery. On multivariate analysis, female sex [odds ratio (OR): 3.50, 95% confidence interval (CI): 1.09 to 11.21], American Society of Anesthesiologist classification >1 (OR: 7.16, CI: 1.95 to 26.29), initial fracture medial/lateral (ML) translation (OR: 1.09, CI: 1.01 to 1.17, per unit change), and initial fracture anterior-posterior (AP) angulation (OR: 1.09, CI: 1.02 to 1.15, per unit change) were independently associated with failure of nonoperative management. Initial fracture displacement values that maximized the sensitivity (SN) and specificity (SP) for failure included an AP angulation >11 degrees (SN 75%, SP 64%) and ML translation >12 mm (SN 55%, SP 75%). The failure rate in patients with none, 1, or both of these fracture parameters was 3.1% (1/32), 35.6% (20/56), and 66.6% (12/18), respectively.

CONCLUSIONS

Nearly one-third of patients experienced failure of initial nonoperative management. Failure was found to be associated with greater initial fracture AP angulation and ML translation. Fracture displacement cut-off values were established that may be used by surgeons to counsel patients with these injuries.

LEVEL OF EVIDENCE

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

Reliability of the Modified Radiographic Union Score for Tibia Fractures (mRUST) for Femoral Shaft Fractures

OBJECTIVES

To evaluate the interobserver and intraobserver reliability of the modified Radiographic Union Score for Tibia Fractures (mRUST) and the effect of rater experience in evaluation of femoral fractures.

DESIGN

Retrospective cohort study.

SETTING

Single Level 1 trauma center.

PATIENTS/PARTICIPANTS

Patients 18-55 years of age with a femur shaft fracture.

INTERVENTION

Intramedullary nail fixation.

MAIN OUTCOME MEASUREMENT

Interobserver and intraobserver reliability using the intraclass correlation coefficient.

RESULTS

The overall interobserver reliability was 0.96. Among fellowship-trained evaluators, the interobserver reliability was 0.94, and it was 0.92 among trainees. The overall intraobserver reliability was 0.98. The intraobserver reliability was 0.97 among fellowship-trained evaluators and 0.96 for trainees.

CONCLUSIONS

These results show high interobserver and intraobserver reliability of mRUST in the evaluation of radiographic healing for femur shaft fractures treated with intramedullary nail. This high reliability was further demonstrated throughout different postoperative healing time frames. In addition, mRUST appears to be reliable when used both by trainees and experienced surgeons for the evaluation of femur shaft fractures.

LEVEL OF EVIDENCE

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

Sustained delivery of a heterodimer bone morphogenetic protein-2/7 via a collagen hydroxyapatite scaffold accelerates and improves critical femoral defect healing

Despite the glimmer of hope provided by the discovery and commercialization of bone morphogenetic protein-2 (BMP-2) as a bone graft substitute, side effects related to the use of supraphysiological doses have hindered its clinical usage. In this study, we compared the osteoinductive potential of BMP-2 homodimer with a heterodimer of BMP-2/7, both delivered via a collagen-hydroxyapatite (CHA) scaffold delivery system, with the aim to reduce the overall therapeutic BMP doses and the associated side-effects. We first show that the incorporation of hydroxyapatite in collagen-based BMP delivery systems is pivotal for achieving efficient BMP sequestration and controlled release. Using an ectopic implantation model, we then showed that the CHA+BMP-2/7 was more osteoinductive than CHA+BMP-2. Further evaluation of the molecular mechanisms responsible for this increased osteoinductivity at an early stage in the regeneration process indicated that the CHA+BMP-2/7 enhanced progenitor cell homing at the implantation site, upregulated the key transcriptomic determinants of bone formation, and increased the production of bone extracellular matrix components. Using fluorescently labelled BMP-2/7 and BMP-2, we demonstrated that the CHA scaffold provided a long-term delivery of both molecules for at least 20 days. Finally, using a rat femoral defect model, we showed that an ultra-low dose (0.5 µg) of BMP-2/7 accelerated fracture healing and performed at a level comparable to 20-times higher BMP-2 dose. Our results indicate that the sustained delivery of BMP-2/7 via a CHA scaffold could bring us a step closer in the quest for the use of physiological growth factor doses in fracture healing. STATEMENT OF SIGNIFICANCE: • Incorporation of hydroxyapatite (HA) in a collagen scaffold dramatically improves bone morphogenic protein (BMP) sequestration via biophysical interactions with BMP, thereby providing more controlled BMP release compared with pristine collagen. • We then investigate the molecular mechanisms responsible for increased osteoinductive potential of a heterodimer BMP-2/7 with is clinically used counterpart, the BMP-2 homodimer. • The superior osteoinductive properties of BMP-2/7 are a consequence of its direct positive effect on progenitor cell homing at the implantation site, which consequently leads to upregulation of cartilage and bone related genes and biochemical markers. • An ultra-low dose of BMP-2/7 delivered via a collagen-HA (CHA) scaffold leads to accelerated healing of a critical femoral defect in rats while a 20-times higher BMP-2 dose was required to achieve comparable results.

The Effect of Free versus Local Flaps on Time to Union in Open Tibia Fractures

BACKGROUND

Early soft-tissue reconstruction of open fractures has been shown to decrease infection rates and improve rates of bony union. The purpose of this study was to compare the rates and time to union of open tibia fractures that underwent soft-tissue coverage.

METHODS

A retrospective chart review of 118 patients with open tibia fractures requiring soft-tissue reconstruction treated at a single level 1 trauma center was performed. Demographic data as well as flap type were collected. Union status was determined using modified Radiographic Union Scale in Tibia Fractures score greater than 11.

RESULTS

Limb salvage was achieved in 90% of patients. The overall rate of nonunion was 33%. Flap type significantly affected time to union, with local fasciocutaneous and keystone flaps having significantly longer time to union [202 days (SD 120.3)] than all other flap groups ( P = 0.01). Free flaps had significantly shorter time to union than local flaps [115 days (SD 49.6) versus 149 days (SD 75.4); P = 0.02]. Muscle flaps had significantly shorter time to union than fasciocutaneous flaps [123 days (SD 52.4) versus 165 days (SD 104.1); P = 0.04]. This remained true after controlling for fracture location, patient age, need for second flap, and fixation method ( P = 0.037). Patients who underwent an initial soft-tissue reconstruction with a local muscle flap were more likely to require a second flap to achieve wound closure (OR, 3.7; P = 0.008) and needing a second flap significantly increased time to union [162 days (SD 95.9) versus 122 days (SD 51.9); P = 0.03].

CONCLUSION

Flap type affects time to union but not nonunion rate in open tibia fractures.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Outcome of tibial shaft fractures treated with the SIGN FIN nail at Addis Ababa Emergency, Burn, and Trauma Hospital (AaEBT) Addis Ababa, Ethiopia

Objectives

To determine the outcome of tibial fractures treated with the SIGN FIN nail.

Study Design

Retrospective case series study.

Study Setting

Trauma center.

Methods and Materials

We included 14 patients aged 18-51 years with 16 tibial fractures in this study. Patients were followed clinically and radiographically, and the minimum time followed was 6 months. Johner and Wruhs criteria with modification were used to assess the outcome.

Result

There were 11 male (78.6%) and three female (21.4%) patients. The mean age was 32.44 ± 8.98 (range 18-51) years. The right-sided tibia was injured in six as compared with the left side in four, and four patients had bilateral injuries. Eight (50%) fractures were closed fractures, whereas the rest eight (50%) were open types of fractures. Among the latter, half (n = 4; 50%) fractures were Gustilo type II fractures, while three (37.5%) fractures were Gustilo type III fractures, and one (12.5%) patient had a Gustilo type I fracture. All patients had radiologic union. There were no infections or secondary surgery for any reason. Excellent, good, and fair results were achieved in 62.5%, 25%, and 12.5%, respectively. All patients were able to return to their preinjury activity except two patients.

Conclusion

SIGN FIN nail is an option for treating tibial shaft fractures with good outcomes and few complications in selected fractures.

Level of evidence

Level IV.

The decisive early phase of bone regeneration

Bone has a remarkable endogenous regenerative capacity that enables scarless healing and restoration of its prior mechanical function, even under challenging conditions such as advanced age and metabolic or immunological degenerative diseases. However - despite much progress - a high number of bone injuries still heal with unsatisfactory outcomes. The mechanisms leading to impaired healing are heterogeneous, and involve exuberant and non-resolving immune reactions or overstrained mechanical conditions that affect the delicate regulation of the early initiation of scar-free healing. Every healing process begins phylogenetically with an inflammatory reaction, but its spatial and temporal intensity must be tightly controlled. Dysregulation of this inflammatory cascade directly affects the subsequent healing phases and hinders the healing progression. This Review discusses the complex processes underlying bone regeneration, focusing on the early healing phase and its highly dynamic environment, where vibrant changes in cellular and tissue composition alter the mechanical environment and thus affect the signalling pathways that orchestrate the healing process. Essential to scar-free healing is the interplay of various dynamic cascades that control timely resolution of local inflammation and tissue self-organization, while also providing sufficient local stability to initiate endogenous restoration. Various immunotherapy and mechanobiology-based therapy options are under investigation for promoting bone regeneration.

Combination of radiographic apparent bone gap and nonunion risk determination score improves accuracy of prediction of tibial shaft delayed union

BACKGROUND

There is a need for a novel therapeutic strategy for an earlier prediction of long bone union failure as compared to previous methodologies. This study aimed to determine whether a combination of two diagnostic tools would result in a more accurate diagnosis of delayed union.

METHODS

The inclusion criteria were as follows: patients with tibial shaft fracture who underwent treatment with intramedullary nailing (IMN) as definitive internal fixation (IF). The study included a total of 114 patients with 116 tibial shaft fractures treated with IMN as definitive IF. Radiographic apparent bone gap (RABG) and nonunion risk determination score (NURDS) can be used to predict nonunion. However, this study aimed to determine whether combination of RABG and NURDS could help deduce a more accurate prediction of delayed union.

RESULTS

The union rate was found to be 85% (99 fractures), the delayed union rate was found to be 15% (17 fractures), and the rate of nonunion requiring additional surgical intervention was estimated to be 4% (5 out of the 17 delayed union cases). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of RABG were found to be 82.3%, 76.0%, 36.8%, and 96.2%, respectively, when an RABG cutoff value of 5.0 mm was applied to our patient cohort. The sensitivity, specificity, PPV, and NPV of NURDS were found to be 47.1%, 82.0%, 30.8%, and 90.1%, respectively, when a NURDS cutoff value of 8.0% was applied to our patient cohort. When RABG and NURDS were above their respective cutoff values, the sensitivity and PPV were estimated to be 90.0% and 56.3%, respectively. When RABG and NURDS were below their respective cutoff values, the specificity and NPV were estimated to be 90.1% and 98.5%, respectively.

CONCLUSIONS

The combination of RABG and NURDS evaluation immediately after surgery helps surgeons identify patients who are at a high risk of delayed union, facilitating careful monitoring of these patients and consideration of additional treatments.

The Effect of Vitamin D Supplementation for Bone Healing in Fracture Patients: A Systematic Review

While most literature on vitamin D supplementation in fracture patients focuses on fracture prevention, the effect of vitamin D on bone healing is a much less studied concept. The primary aim of this systematic review was to assess whether vitamin D supplementation in fracture patients improves clinical or radiological union complications. The secondary aims were to assess supplementation effect on patient functional outcome scores and bone mineral density (BMD). A systematic search of all relevant articles was performed using the following databases: MEDLINE, Embase, Google Scholar, and Web of Science. The population selection included human patients with a fresh fracture treated conservatively or operatively. The intervention included any form of vitamin D supplementation, compared to no supplementation or a placebo. The primary outcomes assessed were clinical or radiological union rates or complications arising from the nonunion. The secondary outcomes assessed were functional outcome scores, BMD scores after treatment, and pain scores. A total of fourteen studies, assessing a total of 2734 patients, were included. Eight studies assessed the effect of vitamin D on clinical or radiological union. Five studies reported no significant difference in complication rates when supplementing fracture patients. Alternatively, three studies reported a positive effect with supplementation between the groups. One of these studies found a difference only for early orthopaedic complications (<30 days), but no differences in late complications. The other two studies found significant differences in clinical union; however, no changes were observed in radiological union. Six studies investigated functional outcome scores after supplementation. Four of these studies found no significant differences between most functional outcome scores. Only three studies reported BMD outcomes, one of which found limited effect on total hip BMD. The overall findings are that vitamin D alone does little to influence fracture healing and subsequent union rates or functional outcome. The studies suggestive of a positive effect were generally of a lower quality. Further high quality RCTs are needed to justify routine supplementation at the time of fracture.

Effect of Vitamin D3 Supplementation on Acute Fracture Healing: A Phase II Screening Randomized Double-Blind Controlled Trial

Nearly half of adult fracture patients are vitamin D deficient (serum 25-hydroxyvitamin D [25(OH)D] levels <20 ng/mL). Many surgeons advocate prescribing vitamin D supplements to improve fracture healing outcomes; however, data supporting the effectiveness of vitamin D₃ supplements to improve acute fracture healing are lacking. We tested the effectiveness of vitamin D₃ supplementation for improving tibia and femur fracture healing. We conducted a single-center, double-blinded phase II screening randomized controlled trial with a 12-month follow-up. Patients aged 18-50 years receiving an intramedullary nail for a tibia or femoral shaft fracture were randomized 1:1:1:1 to receive (i) 150,000 IU loading dose vitamin D₃ at injury and 6 weeks (n = 27); (ii) 4000 IU vitamin D₃ daily (n = 24); (iii) 600 IU vitamin D₃ daily (n = 24); or (iv) placebo (n = 27). Primary outcomes were clinical fracture healing (Function IndeX for Trauma [FIX-IT]) and radiographic fracture healing (Radiographic Union Score for Tibial fractures [RUST]) at 3 months. One hundred two patients with a mean age of 29 years (standard deviation 8) were randomized. The majority were male (69%), and 56% were vitamin D₃ deficient at baseline. Ninety-nine patients completed the 3-month follow-up. In our prespecified comparisons, no clinically important or statistically significant differences were detected in RUST or FIX-IT scores between groups when measured at 3 months and over 12 months. However, in a post hoc comparison, high doses of vitamin D₃ were associated with improved clinical fracture healing relative to placebo at 3 months (mean difference [MD] 0.90, 80% confidence interval [CI], 0.08 to 1.79; p = 0.16) and within 12 months (MD 0.89, 80% CI, 0.05 to 1.74; p = 0.18). The study was designed to identify potential evidence to support the effectiveness of vitamin D₃ supplementation in improving acute fracture healing. Vitamin D₃ supplementation, particularly high doses, might modestly improve acute tibia or femoral shaft fracture healing in healthy adults, but confirmatory studies are required. The Vita-Shock trial was awarded the Orthopaedic Trauma Association's (OTA) Bovill Award in 2020. This award is presented annually to the authors of the most outstanding OTA Annual Meeting scientific paper. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Definitive Taylor Spatial Frame management for the treatment of high-energy open tibial fractures: Clinical and patient-reported outcomes

BACKGROUND

High energy open tibial fractures are complex injuries with no consensus on the optimal method of fixation. Treatment outcomes are often reported with union and re-operation rates, often without specific definitions being provided.  We sought to describe union, reoperation rates, and patient reported outcomes, using the validated EQ-VAS and Disability Rating Index (DRI) scores, following stabilisation with a Taylor Spatial Frame (TSF) and a combined orthoplastic approach for the management of soft tissues. A literature review is also provided.

METHOD

A prospective cross-sectional follow up of open tibial fractures, treated at a level 1 major trauma centre, managed with a TSF using a one ring per segment technique between January 2014 and December 2019 were identified. Demographic, injury and operative data were recorded, along with Patient Reported Outcome Measures (PROM) scores, specifically the EQ-VAS and Disability Rating Index (DRI). Union rates, defined by radiographic union scale in tibia (RUST) scores, and re-operation rates were recorded. Appropriate statistical analyses were performed, with a p<0.05 considered statistically significant.

RESULTS

Overall, 51 patients were included. Mean age was 51.2 ± 17.4 years, with a 4:1 male preponderance. Diaphyseal and distal fractures accounted for 76% of cases. Mean time in frame was 206.7 ± 149.4 days. Union was defined and was achieved in 41/51 (80.4%) patients. Deep infection occurred in 6/51 (11.8%) patients. Amputation was performed in 1 case (1.9%). Overall re-operation rate was 33%. Time to union were significantly longer if re-operation was required for any reason (uncomplicated 204±189 vs complicated 304±155 days; p = 0.0017) . EQ-VAS and DRI scores significantly deteriorated at 1 year follow-up (EQVAS 87.5 ± 11.7 vs 66.5 ± 20.4;p<0.0001 and DRI 11.9 ± 17.8 vs 39.3 ± 23.3;p<0.0001). At 1 year post op, 23/51(45.1%) required a walking aid, and 17/29 (58.6%) of those working pre-injury had returned to work.

CONCLUSION

Open tibial fracture have significant morbidity and long recovery periods as determined by EQVAS and DRI outcome measures.  We report the largest series of open tibial feature treated primarily with a TSF construct, which has similar outcomes to other techniques, and should therefore be considered as a useful technique for managing these injuries.

Intra-Observational and Inter-Observer Agreement of The Radiographic Humerus Union Measurement (RHUM) in Patients Treated with Dynamic Compression Plate for Humeral Shaft Nonunion

BACKGROUND

It is important for orthopedic surgeons to follow the union of the fracture after surgery. This becomes even more important after nonunion surgery. The radiological union scale is popular in the follow-up of unions. However, the intraobserver and interobserver agreement of this scale in humeral nonunion surgery is still not found in the literature.

OBJECTIVE

This study aimed to reveal the intra/interobserver agreement of the Radiographic Union scale (RHUM) for the humerus as well as the relationship between this agreement, plate placement characteristics, and the number of plates in cases where plates were used for surgical treatment of humeral diaphysis nonunion.

MATERIALS AND METHODS

Twenty patients who received surgical treatment for aseptic humeral nonunion at our hospital between 2010-2019 were studied retrospectively. According to RHUM, two observers scored the patients' anteroposterior and lateral radiographs in the postoperative 12th week. The data obtained were statistically analyzed.

RESULTS

The mean age was 52.05±15.88 years. While a single plate was used in 14 cases, a double plate was used in 6 cases. Interobserver agreement was fair-moderate. The interobserver agreement values of the single plate group were significantly higher than those of the double plate group (p<0.05). Interobserver agreement in cases with a lateral plate was significantly higher than in the group where the lateral + posterior plate was applied (p:0.01).

CONCLUSION

In humeral diaphyseal fracture nonunion cases, the number and location of the plate following surgery negatively impact the evaluation of RHUM scores. Given the importance of the union's follow-up and the decision to proceed with additional treatment in these cases, it may be necessary to develop a new method for determining and monitoring the union if a plate was used in the surgical treatment of humeral nonunion.

Evaluation of a modified radiographic union scale for tibial fractures scoring system in staged bilateral tibial plateau leveling osteotomy procedures and comparison of first and second side radiographic bone healing

OBJECTIVE

To evaluate the inter- and intra-rater reliability of the tibial plateau leveling osteotomy (TPLO) modified radiographic union scale for tibial fractures (mRUST), a semiquantitative scoring system, as compared with the subjective evaluation of radiographic union for staged TPLOs.

STUDY DESIGN

Retrospective study.

ANIMALS

Forty-eight dogs, 96 stifles.

METHODS

Medical records were reviewed for dogs with bilateral cranial cruciate ligament injuries diagnosed at presentation that underwent staged bilateral TPLOs within 6 months and had both immediate and recheck postoperative radiographs. Radiographs were anonymized, reviewers were blinded, radiographic union was evaluated subjectively, and TPLO mRUST scores were assigned.

RESULTS

The subjective evaluation's intra-rater reliability was 0.72 (Kappa 95% CI 0.65-0.79) and inter-rater reliability was 0.33 (Kappa 95% CI 0.28-0.39). The TPLO mRUST scoring system intra-rater reliability was 0.73 (95% CI 0.68-0.78) and inter-rater reliability was 0.56 (95% CI 0.41-0.68). There was no difference in the degree of bone healing quantified by the TPLO mRUST scoring system (95% CI - 0.1-1.2, P = .09) or subjective evaluation (P = .48) between the first and second side TPLOs. The TPLO mRUST scores were positively correlated with subjective healing (r = 0.94, 95% CI 0.92-0.96, P < .0001, and for scores ≥10/12, 99%, 244/246) were subjectively assigned as radiographically healed.

CONCLUSION

The TPLO mRUST scoring system improved inter-rater reliability compared to subjective evaluation of radiographic union.

CLINICAL SIGNIFICANCE

The TPLO mRUST scoring system should be considered as a semiquantitative supplemental tool for evaluating radiographic union.

Validation of the modified radiographic union score for tibia fractures (mRUST) in murine femoral fractures

Bony union is a primary predictor of outcome after surgical fixation of long bone fractures. Murine models offer many advantages in assessing bony healing due to their low costs and small size. However, current fracture recovery investigations in mice frequently rely on animal sacrifice and costly analyses. The modified Radiographic Union Score for Tibia fractures (mRUST) scoring system is a validated metric for evaluating bony healing in humans utilizing plain radiographs, which are relatively inexpensive and do not require animal sacrifice. However, its use has not been well established in murine models. The aim of this study was to characterize the longitudinal course of mRUST and compare mRUST to other conventional murine fracture analyses. 158 mice underwent surgically created midshaft femur fractures. Mice were evaluated after fracture creation and at 7, 10, 14, 17, 21, 24, 28, 35, and 42 days post-injury. mRUST scoring of plain radiographs was performed by three orthopaedic surgeons in a randomized, blinded fashion. Interrater correlations were calculated. Micro-computed tomography (μCT) was analyzed for tissue mineral density (TMD), total callus volume (TV), bone volume (BV), trabecular thickness, trabecular number, and trabecular separation. Histomorphometry measures of total callus area, cartilage area, fibrous tissue area, and bone area were performed in a blinded fashion. Ultimate torque, stiffness, toughness, and twist to failure were calculated from torque-twist curves. A sigmoidal log-logistic curve fit was generated for mRUST scores over time which shows mRUST scores of 4 to 6 at 7 days post-injury that improve to plateaus of 14 to 16 by 24 days post-injury. mRUST interrater correlations at each timepoint ranged from 0.51 to 0.86, indicating substantial agreement. mRUST scores correlated well with biomechanical, histomorphometry, and μCT parameters, such as ultimate torque (r=0.46, p<0.0001), manual stiffness (r=0.51, p<0.0001), bone percentage based on histomorphometry (r=0.86, p<0.0001), cartilage percentage (r=-0.87, p<0.0001), tissue mineral density (r=0.83, p<0.0001), BV/TV based on μCT (r=0.65, p<0.0001), and trabecular thickness (r=0.78, p<0.0001), among others. These data demonstrate that mRUST is reliable, trends temporally, and correlates to standard measures of murine fracture healing. Compared to other measures, mRUST is more cost-effective and non-terminal. The mRUST log-logistic curve could be used to characterize differences in fracture healing trajectory between experimental groups, enabling high-throughput analysis.

[Update on non-unions 2022 : Imaging diagnostics, classification and treatment algorithms]

BACKGROUND

Fracture healing is a complex regenerative process. An unconsolidated fracture that will not heal without further surgical intervention is called non-union. The causes are multifactorial. Diagnostic imaging is a central pillar and provides insights into the morphology and biology of the fracture as a basis for optimal surgical treatment decisions.

AIM

Knowledge of fracture healing, targeted radiological and nuclear medical diagnostics, and interdisciplinary standardized classification are of high importance for optimal treatment.

METHODS

In this article, the proven and modern diagnostic procedures are presented, an overview of the currently used scoring and classification models is given and the optimal therapeutic approach based on the extended "diamond concept" is addressed. A possible diagnostic and therapeutic approach is shown using an algorithm.

CONCLUSION

For successful treatment of pseudarthrosis, targeted radiological and nuclear medical diagnostics with old established but also newest methods, such as dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and hybrid imaging, are necessary. An exact classification of non-unions using additional classification models makes it possible to determine and carry out the optimal surgical treatment at an early stage.

High Rate of Radiographic Union at the Fibular Osteotomy Site With No Complications After an Acute Oblique Osteotomy and Ligation Procedure to Shorten the Fibula in High Tibial Osteotomy

Background:

A fibular shortening osteotomy is needed to perform lateral closing-wedge high tibial osteotomy (LCW-HTO). To achieve this shortening, we have recently developed an acute oblique osteotomy and ligation (AO/L) procedure for the center of the fibular shaft, based on the AO procedure.

Purpose:

To compare the 2-year follow-up outcomes between the AO/L procedure and the AO procedure.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

A prospective comparative cohort study was conducted involving 83 patients (83 knees) who underwent shortening osteotomy of the fibula in LCW-HTO between April 2017 and March 2019. The first consecutive 41 knees (AO group) underwent fibular osteotomy with the AO procedure. The remaining 42 knees (AO/L group) underwent fibular osteotomy with the AO/L procedure. All of the patients were evaluated for at least 2 years postoperatively via clinical and radiological assessments. To determine the time needed for complete union at the osteotomy site, we evaluated the radiographs using a radiographic union score for tibial fractures, which was modified for fibular osteotomy. Comparison of outcomes between the 2 groups was performed using the Student t test for continuous variables and the Mann-Whitney U test or Fisher exact test for discrete variables.

Results:

Around the fibular osteotomy site, no perioperative complications were found in either group. The radiographic union score was significantly higher in the AO/L group than in the AO group (P < .0001 at 2, 3, and 6 months; P = .0290 at 12 and 24 months). The union rate at the fibular osteotomy site was significantly higher in the AO/L group (97.6%) than in the AO group (82.9%) at 12 months (P = .0290).

Conclusion:

The AO/L procedure significantly accelerated the formation of bridging callus at the fibular osteotomy site and provided a significantly higher union rate compared with the AO procedure. Both AO/L and AO procedures were free from perioperative complications. These results suggest that the AO/L procedure is clinically useful as an osteotomy procedure to shorten the fibula in LCW-HTO.

Interleukin-1 receptor antagonist enhances the therapeutic efficacy of a low dose of rhBMP-2 in a weight-bearing rat femoral defect model

In the clinical treatment of fractures, rhBMP-2 administration is associated with a well-established profile of side-effects, including osteolysis and ectopic bone formation, which are driven by pro-inflammatory processes triggered by the use of high doses. Immunomodulatory strategies could minimize the incidence of side-effects by enabling the use of lower, and safer, rhBMP-2 doses. This study investigated whether interleukin-1 receptor antagonist (IL-1Ra) can enhance the therapeutic efficacy of a low dose of rhBMP-2 in a weight-bearing femoral fracture healing model. Exogenous IL-1Ra, in combination with rhBMP-2, was delivered using a collagen-hydroxyapatite scaffold (CHA) to attenuate IL-1β produced in response to fracture. Femoral defects were treated with CHA scaffolds alone, or loaded with IL-1Ra (2.5 µg), rhBMP-2 (1 µg), IL-1Ra (2.5 µg) in combination with rhBMP-2 (1 µg). Bone healing was assessed over 14 weeks in comparison to control groups, empty defect, and a higher dose of rhBMP-2 (5 µg), which were recently demonstrated to lead to non-union, and successful bridging of the defect, respectively. The combination of IL-1Ra and rhBMP-2 led to significantly faster early bone formation, at both week 4 and 6, compared to a low dose of rhBMP-2 alone. By 14 weeks, the combination of IL-1Ra and a rhBMP-2 promoted full bridging of femurs, which were 3-fold more mechanically reliable compared to the femurs treated with a low dose of rhBMP-2 alone. Taken together, this study demonstrates that IL-1Ra can significantly enhance femoral bone healing when used in combination with a low dose of rhBMP-2. STATEMENT OF SIGNIFICANCE: Enabling the use of lower and safer doses of rhBMP-2, a potent inducer of bone formation, is of clinical relevance in orthopaedic medicine. In this study, the immunomodulatory interleukin-1 receptor antagonist (IL-1Ra) was investigated for its capacity to enhance the therapeutic efficacy of rhBMP-2 when used at lower doses in a weight-bearing femoral fracture healing model. The combination of IL-1Ra and rhBMP-2 led to significantly faster early bone formation, and resulted in more mechanically reliable healed femurs, compared to a low dose of rhBMP-2 alone. This demonstrates for the first time in a rat long bone healing model that IL-1Ra can significantly enhance bone healing when used in combination with a low dose of rhBMP-2.

Is a staged reloading protocol effective to time the removal of circular frames?

Aims

The timing of when to remove a circular frame is crucial; early removal results in refracture or deformity, while late removal increases the patient morbidity and delay in return to work. This study was designed to assess the effectiveness of a staged reloading protocol. We report the incidence of mechanical failure following both single-stage and two stage reloading protocols and analyze the associated risk factors.

Methods

We identified consecutive patients from our departmental database. Both trauma and elective cases were included, of all ages, frame types, and pathologies who underwent circular frame treatment. Our protocol is either a single-stage or two-stage process implemented by defunctioning the frame, in order to progressively increase the weightbearing load through the bone, and promote full loading prior to frame removal. Before progression, through the process we monitor patients for any increase in pain and assess radiographs for deformity or refracture.

Results

There were 244 frames (230 patients) included in the analyses, of which 90 were Ilizarov type frames and 154 were hexapods. There were 149 frames which underwent single-stage reloading and 95 frames which underwent a two-stage reloading protocol. Mechanical failure occurred after frame removal in 13 frames (5%), which suffered refracture. There were no cases of change in alignment. There was no difference between refracture patients who underwent single-stage or two-stage reloading protocols (p = 0.772). In all, 14 patients had failure prevented through identification with the reloading protocol.

Conclusion

Our reloading protocol is a simple and effective way to confirm the timing of frame removal and minimize the rate of mechanical failure. Similar failure rates occurred between patients undergoing single-stage and two-stage reloading protocols. If the surgeon is confident with clinical and radiological assessment, it may be possible to progress directly to stage two and decrease frame time and patient morbidity.

Cite this article: Bone Jt Open 2022;3(5):359–366.

Autologous osteophyte grafting for ankle arthrodesis

Purpose: Various graft sources had been identified to facilitate gap-filling in ankle arthrodesis procedures with related articular defects. This was a preliminary study with the aim of analyzing the efficacy and feasibility of using autologous osteophyte as a grafting source. Methods: Retrospective evaluation of ten patients having ankle arthrodesis procedure using identical anterior approach and plate fixation technique was conducted. Basic anthropometric measurements and underlying disease were recorded. Functional outcome and fusion rate were assessed at a 12-month post-surgery follow-up visit. Results: The underlying diseases include primary osteoarthritis (OA), post-traumatic OA, rheumatoid arthritis, and Charcot arthropathy. The patient’s age mean was 56.6 years (range 36–71 years), and BMI varied from 17.9 kg/m² to 29.3 kg/m². Nearly all patients had improved functional outcomes as described by foot and ankle ability measure (FAAM) score and fusion rate as described by modified radiographic union score for tibia (RUST). One patient had failed surgery due to implant failure with diminished protective foot sensory. Conclusion: Osteophytes from the distal tibia and talar neck were a viable source of bone graft, especially for ankle arthrodesis using anterior approach among various ages and BMI, in which the surgeons would not need additional incision for graft harvesting.

Future modalities to assess fracture healing

Objectives:

Methods:

Results:

Conclusions:

Progression of Tibia Fracture Healing Using RUST: Are Early Radiographs Helpful?

OBJECTIVES

To report the progression of radiographic healing after intramedullary nailing of tibial shaft fractures using the Radiographic Union Score for Tibial fractures (RUST) and determine the ideal timing of early postoperative radiographs.

DESIGN

Retrospective case series.

SETTING

Urban academic Level 1 trauma center.

PATIENTS/PARTICIPANTS

Three hundred three patients with acute tibial shaft fractures underwent intramedullary nailing between 2006 and 2013, met inclusion criteria, and had at least 3 months of radiographic follow-up.

INTERVENTION

Baseline demographic, injury, and surgical data were recorded for each patient. Each set of postoperative radiographs were scored using RUST and evaluated for implant failure.

MAIN OUTCOME MEASUREMENTS

Postoperative time distribution for each RUST score, RUST score distribution for 4 common follow-up time points, and the presence and timing of implant failure.

RESULTS

The fifth percentile and median times, respectively, for reaching "any radiographic healing" (RUST = 5) was 4.0 weeks and 8.4 weeks, "radiographically healed" (RUST = 9) was 12.1 and 20.9 weeks, and "healed and remodeled" (RUST = 12) was 23.5 weeks and 47.7 weeks. At 6 weeks, 84% of radiographs were scored as RUST ≤ 6 (2 or fewer cortices with callus). No implant failure occurred within the first 8 weeks after surgery, and the indication for all 7 reoperations within this period was apparent on physical examination or immediate postoperative radiographs.

CONCLUSIONS

The median time to radiographic union (RUST = 9) after tibial nailing was approximately 20 weeks, and little radiographic healing occurred within the first 8 weeks after surgery. Routine radiographs in this period may offer little additional information in the absence of clinical concerns such as new trauma, malalignment, or infection.

LEVEL OF EVIDENCE

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

Effect of Lactobacillus casei fermented milk on fracture healing in osteoporotic mice

The interaction between the gut microbiota and the host has been described experimentally by germ-free animals or by antibiotic-disturbed gut microbiota. Studies on germ-free mice have shown that gut microbiota is critical for bone growth and development in mice, emphasizing that microbiota dysbiosis may interfere with normal bone development processes. This study aimed to clarify the effect of antibiotic treatment on disturbed gut microbiota on bone development in mice and to investigate the effect of probiotic treatment on fracture healing in mice with dysbiosis. Our results showed that 4 weeks old female Kunming mice showed significantly lower abundance and diversity of the gut microbiota and significantly lower bone mineral density after 12 weeks of antibiotic treatment and significantly increased levels of RANKL and Ang II in serum (p<0.05). Mice with dysbiosis received 5 mL of Lactobacillus casei fermented milk by daily gavage after internal fixation of femoral fractures, and postoperative fracture healing was evaluated by X-ray, micro-CT scan, and HE staining, which showed faster growth of the broken ends of the femur and the presence of more callus. Serological tests showed decreased levels of RANKL and Ang II (p<0.05). Similarly, immunohistochemical results also showed increased expression of α smooth muscle actin in callus tissue. These results suggest that oral antibiotics can lead to dysbiosis of the gut microbiota in mice, which in turn leads to the development of osteoporosis. In contrast, probiotic treatment promoted fracture healing in osteoporotic mice after dysbiosis, and the probiotic effect on fracture healing may be produced by inhibiting the RAS/RANKL/RANK pathway.

A pilot study of circulating levels of TGF-β1 and TGF-β2 as biomarkers of bone healing in patients with non-hypertrophic pseudoarthrosis of long bones

Background

Pseudoarthrosis or non-union is a complication with an incidence of 5-10% of bone fractures, most frequently located in the diaphysis of long bones. The management of this complication is addressed by means of complex surgical procedures and is a concern for orthopaedic and trauma surgeons nowadays. The use of biomarkers for diagnosing patients at risk of non-union would help us to establish special measures for early corrective treatment.

Methods

Prospective exploratory pilot study with a cohort of 20 patients diagnosed of non-hypertrophic pseudoarthrosis of long bones who were treated surgically with either autologous bone graft or a Tissue Engineering Product composed of bone marrow-derived Mesenchymal Stromal Cells. Patients were followed for 12 months and plasma blood samples were obtained to determine circulating levels of Transforming Growth Factor Beta 1 and Beta 2 (TGF-β1 and TGF-β2, respectively) at inclusion, and at 1 week, 2 weeks, and months 1, 2, 3, 6 and 12 after surgery. Radiological bone healing was evaluated by the Tomographic Union Score (TUS).

Results

Basal levels of TGF-β1 and TGF-β2 were determined in the twenty patients (26,702 ± 14,537 pg/mL and 307.8 ± 83.1 pg/mL, respectively). Three of them withdrew from the study, so complete follow-up was conducted on 17 patients (9 successfully healed vs. 8 that did not heal). Statistically significant differences between the bone healing group and the non-union group were found at month 12 for both TGF-β1 (p = 0.005) and TGF-β2 (p = 0.02).

Conclusions

TGF-β1 and TGF-β2 are biomarkers that correlate with clinical evidence of bone regeneration and may be used to monitor patients, although early predictive value after intervention needs to be further studied in combination with other molecules.

3D ultrasound reconstruction of sonographic callus : a novel imaging modality for early evaluation of fracture healing

AIMS

The aim of this study was to establish a reliable method for producing 3D reconstruction of sonographic callus.

METHODS

A cohort of ten closed tibial shaft fractures managed with intramedullary nailing underwent ultrasound scanning at two, six, and 12 weeks post-surgery. Ultrasound capture was performed using infrared tracking technology to map each image to a 3D lattice. Using echo intensity, semi-automated mapping was performed to produce an anatomical 3D representation of the fracture site. Two reviewers independently performed 3D reconstructions and kappa coefficient was used to determine agreement. A further validation study was undertaken with ten reviewers to estimate the clinical application of this imaging technique using the intraclass correlation coefficient (ICC).

RESULTS

Nine of the ten patients achieved union at six months. At six weeks, seven patients had bridging callus of ≥ one cortex on the 3D reconstruction and when present all achieved union. Compared to six-week radiographs, no bridging callus was present in any patient. Of the three patients lacking sonographic bridging callus, one went onto a nonunion (77.8% sensitive and 100% specific to predict union). At 12 weeks, nine patients had bridging callus at ≥ one cortex on 3D reconstruction (100%-sensitive and 100%-specific to predict union). Presence of sonographic bridging callus on 3D reconstruction demonstrated excellent reviewer agreement on ICC at 0.87 (95% confidence interval 0.74 to 0.96).

CONCLUSION

3D fracture reconstruction can be created using multiple ultrasound images in order to evaluate the presence of bridging callus. This imaging modality has the potential to enhance the usability and accuracy of identification of early fracture healing. Cite this article: Bone Joint Res 2021;10(12):759-766.

Assessment of clinical and radiographic outcomes following retrograde versus antegrade nailing of infraisthmic femoral shaft fractures without the use of intraoperative fluoroscopy in Tanzania

To compare clinical and radiographic outcomes following antegrade versus retrograde intramedullary nailing of infraisthmic femoral shaft fractures.

Design

Secondary analysis of prospective cohort study.

Setting

Tertiary hospital in Tanzania.

Participants

Adult patients with infraisthmic diaphyseal femur fractures.

Intervention

Antegrade or retrograde SIGN intramedullary nail.

Outcomes

Health-related quality of life (HRQOL), radiographic healing, knee range of motion, pain, and alignment (defined as less than or equal to 5 degrees of angular deformity in both coronal and sagittal planes) assessed at 6, 12, 24, and 52 weeks postoperatively.

Results

Of 160 included patients, 141 (88.1%) had 1-year follow-up and were included in analyses: 42 (29.8%) antegrade, 99 (70.2%) retrograde. Antegrade-nailed patients had more loss of coronal alignment (P = .026), but less knee pain at 6 months (P = .017) and increased knee flexion at 6 weeks (P = .021). There were no significant differences in reoperations, HRQOL, hip pain, knee extension, radiographic healing, or sagittal alignment.

Conclusions

Antegrade nailing of infraisthmic femur fractures had higher incidence of alignment loss, but no detectable differences in HRQOL, pain, radiographic healing, or reoperation. Retrograde nailing was associated with increased knee pain and decreased knee range of motion at early time points, but this dissipated by 1 year. To our knowledge, this is the first study to prospectively compare outcomes over 1 year in patients treated with antegrade versus retrograde SIGN intramedullary nailing of infraisthmic femur fractures.Level of Evidence: III.

Radiographic union score for tibia (RUST) scoring system in adult diaphyseal femoral fractures treated with intramedullary nailing: an assessment of interobserver and intraobserver reliability

OBJECTIVES

The Radiographic Union Score for Tibia (RUST) scoring system has been validated in multiple studies assessing the healing of tibial fractures. Our objective was to assess the interobserver and intraobserver reliability for the RUST in diaphyseal femoral fractures treated with intramedullary (IM) nailing.

PATIENTS AND METHODS

A total of 60 sets of anteroposterior (AP) and lateral radiographs of diaphyseal femoral fractures treated by reamed IM nailing were randomly selected from a prospectively collected database. The 60 sets of radiographs were then scored by three reviewers using the RUST system. Interobserver reliability was measured at initial scoring. The 60 sets of radiographs were scored again by the three reviewers to calculate the intraobserver reliability.

RESULTS

The RUST scores ranged from 4 to 12 with a mean score of 11.3 ± 1.3. The interobserver intraclass correlation coefficient (ICC) was 0.87 (95% CI, 0.81-0.92) and the intraobserver ICC was 0.91 (95% CI, 0.88-0.94), which indicated excellent agreement.

CONCLUSION

This study demonstrated that the RUST system can be used reliably in the assessment of healing in diaphyseal femur fractures treated by reamed intramedullary nailing, with excellent interobserver and intraobserver reliability.

Sensitivity and specificity of modified RUST score using clinical and radiographic findings as a gold standard

Aims

The modified Radiological Union Scale for Tibia (mRUST) fractures score was developed in order to assess progress to union and define a numerical assessment of fracture healing of metadiaphyseal fractures. This score has been shown to be valuable in predicting radiological union; however, there is no information on the sensitivity, specificity, and accuracy of this index for various cut-off scores. The aim of this study is to evaluate sensitivity, specificity, accuracy, and cut-off points of the mRUST score for the diagnosis of metadiaphyseal fractures healing.

Methods

A cohort of 146 distal femur fractures were retrospectively identified at our institution. After excluding AO/OTA type B fractures, nonunions, follow-up less than 12 weeks, and patients aged less than 16 years, 104 sets of radiographs were included for analysis. Anteroposterior and lateral femur radiographs at six weeks, 12 weeks, 24 weeks, and final follow-up were separately scored by three surgeons using the mRUST score. The sensitivity and specificity of mean mRUST score were calculated using clinical and further radiological findings as a gold standard for ultimate fracture healing. A receiver operating characteristic curve was also performed to determine the cut-off points at each time point.

Results

The mean mRUST score of ten at 24 weeks revealed a 91.9% sensitivity, 100% specificity, and 92.6% accuracy of predicting ultimate fracture healing. A cut-off point of 13 points revealed 41.9% sensitivity, 100% specificity, and 46.9% accuracy at the same time point.

Conclusion

The mRUST score of ten points at 24 weeks can be used as a viable screening method with the highest sensitivity, specificity, and accuracy for healing of metadiaphyseal femur fractures. However, the cut-off point of 13 increases the specificity to 100%, but decreases sensitivity. Furthermore, the mRUST score should not be used at six weeks, as results show an inability to accurately predict eventual fracture healing at this time point.

Cite this article: Bone Jt Open 2021;2(10):796–805.

Tibia Nailing Without C-Arm Guidance: Challenges and Successes

Purpose

There are increased trends in the last two to three decades to operate tibia fractures to ensure acceptable reduction over long period of time and to ensure early mobilization and return to work. This leads to frequent use of C-arm to perform the procedures. The purpose of our study is to reduce the exposure of radiation to the patient and healthcare workers during closed nailing of fractures.

Methods and materials

This is an institute-based retrospective cohort study. Patients operated with tibia interlocking nailing between November 2016 and November 2018 were shortlisted from the OT records. Seventy-six patients were shortlisted and their clinical records were retrieved. Fifty-eight patients fulfilling the inclusion criteria were included in the study. 28 patients had Tibia interlocking nailing done without using C-arm and 30 patients had tibia interlocking nailing done under C-arm guidance. IBM SPSS software was used to compare data between the groups using Chi-square test and Independent T-test with a 95% confidence interval to determine the significance.

Results

All the patients progressed to the union by six months of surgery. Average blood loss, Infection rates and time to union in both the groups were comparable. Though the average duration of surgery was significantly higher in non-C-arm group as compared to with C arm group, when the duration of individual surgeries was analysed and plotted sequentially on a chart, we found it was comparable in later cases.

Conclusions

With adequate practice, tibial nailing without C-arm is easy, requires minimal manpower, equipment and can also prove to be a lifesaver in case of equipment failure.

Site-Specific Fracture Healing: Comparison between Diaphysis and Metaphysis in the Mouse Long Bone

The process of fracture healing varies depending upon internal and external factors, such as the fracture site, mode of injury, and mechanical environment. This review focuses on site-specific fracture healing, particularly diaphyseal and metaphyseal healing in mouse long bones. Diaphyseal fractures heal by forming the periosteal and medullary callus, whereas metaphyseal fractures heal by forming the medullary callus. Bone healing in ovariectomized mice is accompanied by a decrease in the medullary callus formation both in the diaphysis and metaphysis. Administration of estrogen after fracture significantly recovers the decrease in diaphyseal healing but fails to recover the metaphyseal healing. Thus, the two bones show different osteogenic potentials after fracture in ovariectomized mice. This difference may be attributed to the heterogeneity of the skeletal stem cells (SSCs)/osteoblast progenitors of the two bones. The Hox genes that specify the patterning of the mammalian skeleton during embryogenesis are upregulated during the diaphyseal healing. Hox genes positively regulate the differentiation of osteoblasts from SSCs in vitro. During bone grafting, the SSCs in the donor’s bone express Hox with adaptability in the heterologous bone. These novel functions of the Hox genes are discussed herein with reference to the site-specificity of fracture healing.

NURD 2.0: Prediction of tibial nonunion after intramedullary nail fixation at any time within 3 months after injury

Introduction Nonunion after fixation of long bones negatively impacts outcomes and requires additional surgery. The ability to predict likelihood of nonunion after tibial shaft fracture would be helpful to clinicians and patients. The goal of this work was to combine three previous models of tibial shaft nonunion at different time points into one overall model that incorporates time as a continuous variable. Methods We conducted a retrospective review at a Level I academic trauma center. The study cohort consisted of patients with tibial shaft fractures treated with nail insertion from 2007 through 2014, excluding patients who did not have contact between bone ends, those who had planned bone grafting for acute bone defects, and those who lacked adequate follow-up. Three previous models were combined: 382 patients at time 0, 323 at 6 weeks, and 240 at 12 weeks. The primary outcome variable was surgery for nonunion. Bivariate and multivariate regression analyses determined which of 42 clinical and radiographic variables were significantly associated with nonunion. Predictive power was evaluated using area under the curve (AUC). Results The original nonunion risk determination (NURD) score was significantly improved through addition of 6- and 12-week radiographic union scores for tibial fractures, infection and complications, smoking status, and need for flaps. Overall, over the course of 12 weeks, the NURD-based model produced an AUC of 0.87 at initial time of fixation that improved to >0.9 at 6 and 12 weeks. Data were used to bin patients into five clinically important risk strata (p < 0.001). Patients in the lowest risk strata had 0% probability of nonunion (0 of 97 patients); in the second lowest risk strata, 4% (three of 73 patients); and in the highest risk strata, 48% (38 of 80 patients). Conclusions We created a NURD 2.0 score that predicts nonunion at various time points during the first 3 months after fracture. The new model is a notable improvement over previous models. A computerized version allows surgeons and patients to use the score when making treatment decisions regarding need for nonunion surgery.

Monitoring of fracture healing. Update on current and future imaging modalities to predict union

Fracture nonunion causes considerable patient morbidity and an associated burden to society. Traditional reliance on radiographs to monitor union has limitations as bridging callus of long bone fractures can take three or more months to occur. Computed Tomographic (CT) scanning is becoming increasingly popular and can evaluate bridging callus in the late stages of healing to confirm union. The use of dynamic contrast enhanced Magnetic Resonance Imaging (MRI) and advances in nuclear imaging may yield benefits in the assessment of the infected nonunion. Emerging evidence supports the use of ultrasound to detect bridging callus prior to radiographic confirmation and it may be of use to predict patients at high risk of nonunion. This paper is part of a Supplement supported by The Osteosynthesis and Trauma Care Foundation (OTCF).

Effect of compression fracture on trabecular bone score at lumbar spine

Bone mineral density (BMD) may be increased due to vertebral compression fractures (VCF). Our study showed trabecular bone scores (TBS) was less affected than BMD by fractured vertebrae. The TBS of most compression fractures, including old and recent VCF with mild or moderate deformity and old VCF with severe deformity, could still be used in predicting fracture risk.

INTRODUCTION

Trabecular bone score (TBS), a noninvasive tool estimating bone microarchitecture, provides complementary information to lumbar spine bone mineral density (BMD). Lumbar spine BMD might be increased due to both degenerative disease and vertebral compression fractures (VCF). Lumbar spine TBS has been confirmed not influenced by osteoarthrosis, but the effects of VCF are still not been well evaluated. This study aimed to investigate whether lumbar spine TBS was affected by fractured vertebrae.

METHODS

We studied postmenopausal women and men above 50 years old who underwent DXA between January 1, 2017, and May 31, 2019. By calculating the difference of BMD and TBS between L1 and the mean of L2-3, the study compared the difference of values between the control group and fracture group to determine the effects of fractured vertebrae on BMD and TBS.

RESULTS

A total of 377 participants were enrolled with 202 in the control group (157 females; age: 68.06 ± 6.47 years) and 175 in the fracture group (147 females; age: 71.71 ± 9.44 years). The mean BMD of the L1 vertebrae in the fracture group was significantly higher than that in the control group (p < 0.0001). There was no significant difference between the mean differences of TBS between L1 and the means of L2-3 vertebrae in the control group and the most compression fractures, including old and recent VCF with mild or moderate deformity and old VCF with severe deformity.

CONCLUSION

Lumbar spine TBS, unlike BMD, is less affected by fractured vertebrae. The TBS of most compression fractures, including old and recent VCF with mild or moderate deformity and old VCF with severe deformity, could still be used in predicting fracture risk.

Reamed intramedullary nailing versus circular frame external fixation for segmental tibial fractures (STIFF-F): a mixed methods feasibility study

BACKGROUND

Segmental tibial fractures are fractures in two or more areas of the tibial diaphysis resulting in a separate intercalary segment of the bone. Surgical fixation is recommended for patients with segmental tibial fractures as non-operative treatment outcomes are poor. The most common surgical interventions are intramedullary nailing (IMN) and circular frame external fixation (CFEF), but evidence about which is better is of poor quality. An adequately powered randomised controlled trial (RCT) to determine optimum treatment is required. STIFF-F aimed to assess the feasibility of a multicentre RCT comparing IMN with CFEF for segmental tibial fracture.

METHODS

STIFF-F was a mixed-methods feasibility study comprising a pilot RCT conducted at six UK Major Trauma Centres, qualitative interviews drawing on Phenomenology and an online survey of rehabilitation. The primary outcome was recruitment rate. Patients, 16 years and over, with a segmental tibial fracture (open or closed) deemed suitable for IMN or CFEF were eligible to participate. Randomisation was stratified by site using random permuted blocks of varying sizes. Participant or assessor blinding was not possible. Interviews were undertaken with patients about their experience of injury, treatment, recovery and participation. Staff were interviewed to identify contextual factors affecting trial processes, their experience of recruitment and the treatment pathway. An online survey was developed to understand the rehabilitation context of the treatments.

RESULTS

Eleven patients were screened and three recruited to the pilot RCT. Nineteen staff and four patients participated in interviews, and 11 physiotherapists responded to the survey. This study found the following: (i) segmental tibial fractures were rarer than anticipated, (ii) the complexity of the injury, study setup times and surgeon treatment preferences impeded recruitment, (iii) recovery from a segmental tibial fracture is challenging, and rehabilitation protocols are inconsistent and (iv) despite the difficulty recruiting, staff valued this research question and strived to find a way forward.

CONCLUSION

The proposed multicentre RCT comparing IMN with CFEF is not feasible. This study highlighted the difficulty of recruiting patients to an RCT of a complex rare injury over a short time period.

TRIAL REGISTRATION

The study was registered with the International Standard Randomised Controlled Trials Number Registry: ISRCTN11229660.

The accuracy of computed tomography for clavicle non-union evaluation

BACKGROUND

The primary aim of this study is to determine the accuracy of CT scanning when evaluating non-union of the clavicle.

METHODS

A retrospective review was performed of all CT scans undertaken for suspected nonunion of midshaft clavicle fractures over a 10-year period. The influence of scan timing, callus and patient characteristics was evaluated.

RESULTS

One hundred eighty-four CT scans were analysed. No patient was incorrectly diagnosed with union (n = 85). Ninety-nine scans were reported as non-union with inadequate bridging callus, 19 of which were united at operation or on repeat CT imaging and represented delayed unions. Atrophic callus was found in 57 patients and all of which had a confirmed non-union (positive predictive value 100%). A hypertrophic callus was found in 42 patients, all of the delayed unions were found in this group (positive predictive value for non-union 55%, p < 0.001). CT compared to radiographs showed greater inter-observer agreement for union (weighted kappa 0.75 vs. 0.50 respectively). Overall, CT is 100% sensitive and 81.7% specific for non-union diagnosis.

DISCUSSION

CT has excellent accuracy to determine clavicle union but approximately one in five suspected non-unions went onto unite. Hypertrophic callus finding resulted in a delayed union in approximately half of the cases in our study.

Risk factors associated with delayed and aseptic nonunion following tibial diaphyseal fractures managed with intramedullary nailing

Aims

The primary aim of this study was to identify independent predictors associated with nonunion and delayed union of tibial diaphyseal fractures treated with intramedullary nailing. The secondary aim was to assess the Radiological Union Scale for Tibial fractures (RUST) score as an early predictor of tibial fracture nonunion.

Methods

A consecutive series of 647 patients who underwent intramedullary nailing for tibial diaphyseal fractures were identified from a trauma database. Demographic data, comorbidities, smoking status, alcohol consumption, use of non-steroidal anti-inflammatory drugs (NSAIDs), and steroid use were documented. Details regarding mechanism of injury, fracture classification, complications, and further surgery were recorded. Nonunion was defined as the requirement for revision surgery to achieve union. Delayed union was defined as a RUST score < 10 at six months postoperatively.

Results

There were 41 nonunions (6.3%), of which 13 were infected (31.7%), and 77 delayed unions (11.9%). There were 127 open fractures (19.6%). Adjusting for confounding variables, NSAID use (odds ratio (OR) 3.50; p = 0.042), superficial infection (OR 3.00; p = 0.026), open fractures (OR 5.44; p < 0.001), and high-energy mechanism (OR 2.51; p = 0.040) were independently associated with nonunion. Smoking (OR 1.76; p = 0.034), open fracture (OR 2.82; p = 0.001), and high-energy mechanism (OR 1.81; p = 0.030) were independent predictors associated with delayed union. The RUST score at six-week follow-up was highly predictive of nonunion (sensitivity and specificity of 75%).

Conclusion

NSAID use, high-energy mechanisms, open fractures, and superficial infection were independently associated with nonunion in patients with tibial diaphyseal fractures treated with intramedullary nailing. The six-week RUST score may be useful in identifying patients at risk of nonunion.

Cite this article: Bone Jt Open 2021;2(4):227–235.

Virtual mechanical tests out-perform morphometric measures for assessment of mechanical stability of fracture healing in vivo

Finite element analysis with models derived from computed tomography (CT) scans is potentially powerful as a translational research tool because it can achieve what animal studies and cadaver biomechanics cannot-low-risk, noninvasive, objective assessment of outcomes in living humans who have actually experienced the injury, or treatment being studied. The purpose of this study was to assess the validity of CT-based virtual mechanical testing with respect to physical biomechanical tests in a large animal model. Three different tibial osteotomy models were performed on 44 sheep. Data from 33 operated limbs and 20 intact limbs was retrospectively analyzed. Radiographic union scoring was performed on the operated limbs and physical torsional tests were performed on all limbs. Morphometric measures and finite element models were developed from CT scans and virtual torsional tests were performed to assess healing with four material assignment techniques. In correlation analysis, morphometric measures and radiographic scores were unreliable predictors of biomechanical rigidity, while the virtual torsion test results were strongly and significantly correlated with measured biomechanical test data, with high absolute agreement. Overall, the results validated the use of virtual mechanical testing as a reliable in vivo assessment of structural bone healing. This method is readily translatable to clinical evaluation for noninvasive assessment of the healing progress of fractures with minimal risk. Clinical significance: virtual mechanical testing can be used to reliably and noninvasively assess the rigidity of a healing fracture using clinical-resolution CT scans and that this measure is superior to morphometric and radiographic measures.

Augmented compression in exchange nailing for femoral and tibial non-unions accelerates time to radiographic union

PURPOSE

Exchange nailing is widely used for the management of aseptic femoral and tibial non-union. Compressive forces markedly reduce strain, increasing rate and incidence of union. Additional compressive forces can be applied to the non-union site by using the design features of some modern nailing systems. This study hypothesises that the use of additional compression in exchange nailing results in faster time to union.

METHODS

All femoral and tibial shaft non-unions were identified over a 4-year period between 2014-2018. Intraoperative compression during exchange nailing was either applied or not applied with a dedicated active compression device through the intramedullary nail. An initial 'radiographic union score for tibia' (RUST) score was calculated from preoperative lateral and AP radiographs and compared with the postoperative radiographs at 6-8 weeks. Healing was defined as bridging callus on at least three cortices (RUST > 10).

RESULTS

A total of 119 patients were identified. Following application of exclusion criteria, we analysed data for 19 patients, 10 undergoing exchange nailing with intraoperative compression and 9 without. The pre-exchange RUST score was comparable between the compressed group and standard exchange group with mean of 7.11 versus 7.5 (p = 0.636). At 6-8 weeks post-op, there was a significant difference between the median RUST score in the compressed group vs standard exchange group, 11 compared to 8.39 (p = 0.001).

CONCLUSIONS

Our study shows that time to union was accelerated when additional compression was applied to exchange nailing, resulting in reduced follow-up visits and number of radiographs required.

The degree of correction in open-wedge high tibial osteotomy compromises bone healing: A consecutive review of 101 cases

BACKGROUND

The bone healing in open-wedge high tibial osteotomy (OWHTO) proceeds gradually by a filling of the osteotomy gap. This can comprise several risk factors.

METHODS

A retrospective study analysed the clinical and radiological course of 101 consecutive OWHTOs in 96 patients. The following risk factors were considered: age, body mass index, tobacco consumption, amount of tobacco consumption, severity of comorbidities, infection of the surgical area, occurrence of a lateral hinge fracture and the degree of correction. The bone healing was evaluated by using the modified Radiographic Union Score for Tibial fractures (RUST).

RESULTS

A disturbance in bone healing was observed in 16 of the 101 osteotomies. Binary logistic regression analysis showed a correlation between the angle of the opening wedge and the development of a disturbance in bone healing (P = 0.002). The odds ratio indicated an increase in the risk of a disturbance in bone healing of 56% with each additional degree of correction. For the risk factor 'age' a statistical trend was recognizable (P = 0.077) with the risk of a disturbance in bone healing in higher age.

CONCLUSION

Lateral hinge fractures seem not to have a detrimental effect on the filling of the osteotomy gap. An increase in the opening wedge bears the risk of a disturbance in bone healing.

Acute correction and intramedullary nailing of aseptic oligotrophic and atrophic tibial nonunions with deformity

Objectives

This study aims to describe the important points for treatment of aseptic tibial oligotrophic and atrophic nonunions by intramedullary nailing (IMN).

Patients and methods

The retrospective study included 17 biologically nonactive nonunion patients (12 males, 5 females; mean age 36.4 years; range, 19 to 49 years) operated between February 2010 and November 2017 by deformity correction, static IMN and autografting. The mean follow-up time was 4.2 (range, 3 to 7) years. The initial fracture management was external fixator for all patients. Fourteen patients had open fractures initially. Six patients had valgus, four patients had varus, three patients had oblique plane, and four patients had external rotational deformity. Nonunion diagnosis was established on the basis of the patient history and physical examination based on plain radiographs, computed tomography or both. All patients were evaluated by the same protocol to exclude any infection.

Results

The median time from injury to nailing was mean 10.3 (range, 6.1 to 36.5) months. Radiologic and clinical union was achieved in all patients. The mean union time was 3.64 (range, 3 to 6) months. Three patients had positive intraoperative bacteriological culture. In four patients, dynamization was necessary for consolidation. Late deep infection developed in three patients after union, and all infected cases were operated by implant removal, debridement, and appropriate antibiotics.

Conclusion

Intramedullary nailing and autografting after external fixator provide good results for the treatment of aseptic biologically nonactive nonunions with deformity. Reamed IMN ensures sufficient deformity correction, biological environment, and mechanical stability. The infection risk should always be kept in mind and patients should be followed-up closely to prevent complications.