Outcome assessment in clinical trials of fracture-healing

The methodology and interpretation of radiographic measures for malunion in proximal humerus fractures: a systematic review

BACKGROUND

Radiographic imaging is an essential tool for surgeons in classifying injury, guiding treatment decision-making, and assessing for adequate intraoperative reduction. However, the heterogeneity in radiographic outcome measures utilized in clinical studies evaluating proximal humerus fracture treatment has made it difficult for surgeons to interpret and analyze the available evidence, leading to continued controversy in the optimal management of these injuries. The aims of this systematic review are to 1) examine the literature to describe the methods for measuring and interpreting radiographic outcomes for malunion and 2) identify studies that have correlated functional outcome measures and radiographic outcome measures.

METHODS

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline, a systematic review of the literature was performed using EMBASE, MEDLINE, and the Cochrane Database of Systematic Reviews from inception to January 30, 2024. Outcomes of interest included radiographic outcome measures and functional outcome measures including pain assessment and range of motion measurements.

RESULTS

A total of 36 studies that used radiographic measures of alignment following treatment and union of proximal humerus fractures were identified. The most common measure was the head-shaft angle, utilized in 33 studies (92%). Tuberosity position was reported in 22 studies (61%). Only 21 studies (58%) provided a clear and reproducible technique for obtaining radiographic measures. The interpretation for radiographic malunion varied between studies. Varus malunion, using head-shaft angle measures, was defined as under 105° to under 130° in different studies. Although there is known variation between patients, only 3 studies utilized the imaging from the contralateral shoulder to define patient specific measures for malunion. Twenty-two studies assessed for an association between head-shaft angle malunion and patient functional outcome measures.

DISCUSSION AND CONCLUSION

Given the broad and inconsistent definition of malunion used between the included studies, there remains a lack of clear threshold for radiographic measures of alignment that surgeons can use in their clinical decision-making for proximal humerus fractures. Based on the evidence available, we propose a consistent definition of head-shaft angle measurement drawn from specified radiographic views, with varus malunion defined as <125° and valgus malunion >140°. To optimize the management and outcome of these fractures, radiographic outcomes must be standardized and correlated with function.

Nonunion of Adult Forearm Fractures: Evaluation of Intramedullary Nailing With Grafting as a Treatment Option

OBJECTIVES

To evaluate the effectiveness of intramedullary nailing combining with iliac or fibular autograft for the treatment of adult forearm nonunions.

METHODS

DESIGN

Retrospective case series.

SETTING

Two academic trauma referral centers.

PATIENT SELECTION CRITERIA

Adult patients who sustained surgical treatment for forearm fracture (OTA/AO 2R2-2U2) nonunion with intramedullary nailing and grafting from May 2005 to January 2023 were included.

OUTCOME MEASURES AND COMPARISONS

The primary outcome was to determine the bone union rates after nonunion surgery with intramedullary nail and grafting. Secondary outcomes were to assess functional scores including The Visual Analog Score; the shortened version of the Disabilities of the Arm, Shoulder, and Hand (QuickDASH) questionnaire; Grace-Eversmann evaluation criteria.

RESULTS

The study included 24 patients comprising 19 men and 5 women (7 radius, 14 ulna, 3 both bones) with an average age at the time of surgery of 40.5 ± 11.2 years (range, 23-61 years) and union was achieved for 24 out of 27 bones (88.8%) in 22 out of 24 patients. The mean (average) preoperative and postoperative QuickDASH scores were found as 64.5 ± 18.2 and 15.3 ± 18.9, respectively. The functional improvement was found statistically significant ( P < 0.001). The mean (average) preoperative and postoperative Visual Analog Score was found to be 7.2 ± 2.1 and 1.52 ± 1.5, respectively. The difference was found statistically significant ( P < 0.001). Two cases of radius nonunion healed with 10 degrees and 15 degrees of angulation and shortening, while nonunion persisted in 2 patients. All remaining cases healed without deformity. Excellent to acceptable results were obtained for 83.3% of patients according to Grace-Eversmann criteria.

CONCLUSONS

Intramedullary nailing with autologous grafting is a viable option for the treatment of adult forearm nonunions.

LEVEL OF EVIDENCE

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

Improving agreement in assessing subtrochanteric fracture healing among orthopedic surgeons using the Radiographic Union Score for Hip (RUSH)

BACKGROUND

Prompt identification of fracture healing is crucial for medical decision-making and clinical research. This study aims to assess the effectiveness of the Radiographic Union Score for Hip (RUSH) in subtrochanteric fractures and determine the optimal scoring threshold for fracture healing.

METHODS

We obtained 94 sets of X-ray films from the postoperative follow-up of 35 patients who underwent intramedullary nail fixation for subtrochanteric fractures. Six orthopedic trauma surgeons evaluated the imaging data and determined fracture healing based on subjective judgment. They then scored the X-ray images using the RUSH form. After four weeks, the same observers re-evaluated 47 randomly selected sets of radiographs. Subsequently, the observers and study designer conducted a consensus meeting where they agreed on whether the fractures had healed. We used Fleiss kappa to evaluate agreement among observers based on subjective impressions, and the intraclass correlation coefficient assessed RUSH score consistency. Regression analysis examined the relationship between scores and fracture healing consensus using a receiver operator characteristic (ROC) curve.

RESULTS

Based on overall impressions, the agreement level among orthopedic trauma surgeons for determining the healing status of subtrochanteric fractures was moderate (Kappa = 0.564, 95% CI: 0.511-0.616). However, utilizing the RUSH scoring system can improve the consistency to a substantial level of agreement (ICC = 0.748, 95% CI: 0.663-0.817). Regarding intraobserver reliability, there were significant differences among orthopedic trauma surgeons in judging fracture healing based on overall impressions. However, using the RUSH scoring form, the attending group achieved better intraobserver consistency than the resident group. Regression analysis and ROC curve analysis revealed a strong correlation between the RUSH total score, cortical bone score, cancellous bone score, and consensus on fracture healing. The AUC values are 0.769 (95% CI: 0.670-0.868), 0.779 (95% CI: 0.681-0.876), and 0.771 (95% CI: 0.674-0.867), respectively.

CONCLUSIONS

Our study highlights the effectiveness of the RUSH scoring system in enhancing interobserver agreement and intraobserver consistency when evaluating subtrochanteric fracture healing in orthopedic trauma surgeons. We propose setting 21 points as the threshold for the simplified RUSH scoring system to determine fracture healing. This system includes only eight items related to cortical bone, with a total score of 24 points.

Distal femur fractures in elderly treated with internal fixation or distal femoral replacement - retrospective cohort study on 75 patients assessing functional outcomes, reoperations, and mortality

PURPOSE

This cohort study aimed to describe the functional outcomes, complications, and mortality of patients over 65 with acute distal femur fractures treated with open reduction and internal fixation (ORIF) or distal femoral replacement (DFR).

METHODS

We retrospectively analyzed all patients older than 65, operated consecutively for a distal femur fracture treated with ORIF or DFR. We included 75 patients (9 33A, 5 33B, and 61 33C AO/OTA fractures), 55 treated with ORIF, and 20 with DFR. We used Parker's mobility index (PMI) to assess functional outcomes at 1, 3, and 12 months and study closure. We analyzed complications, reoperations, and mortality at 30 days, one year, and at the end of the study.

RESULTS

The PMI was significantly higher in the DFR group at months 1 (p = 0.023) and 3 (p = 0.032). We found no significant differences between cohorts at one year and the end of follow-up. Postoperative complications were significantly more frequent in the ORIF group (38.10% vs. 10%, p = 0.022). Reoperations were similar in both cohorts (p = 0.98). Mortality at one month was 4% and 20% at one year, and at the end of follow-up, there were no significant differences between groups.

CONCLUSION

The outcomes of this study suggest that DFR offers a faster functional recovery with lower complication rates than those treated with ORIF. Additionally, both options have similar reoperation and mortality rates. Appropriately designed studies are needed to define the best treatment strategy for this type of patient.

The outcomes of the management of complex distal tibia and ankle fractures in elderly with tibiotalocalcaneal nail in a minimum 12-month follow-up period

PURPOSE

To evaluate the clinical outcomes of the use of tibiotalocalcaneal nail for the treatment of complex distal tibia and ankle fractures in elderly people, in a major trauma centre.

METHODS

Elderly patients (age > 65) with distal tibia or ankle fractures that underwent stabilization with a tibiotalocalcaneal nail were eligible to participate. Exclusion criteria were patients that died or were lost to follow-up and cases in which the nail was used in a chronic setting, such as malunion and non-union. Main parameters evaluated were fracture union, complications and functional outcomes. The functional outcome was assessed using the Olerud-Molander Ankle Score (OMAS). The minimum follow-up was 12 months.

RESULTS

Thirty-two consecutive patients (12 males) with a mean age of 80.2 years (range 66-98) met the inclusion criteria and formed the basis of this study. Fracture union was achieved in 93.8% of the cases at a mean time of 3.9 months (range 2-8). Two patients developed surgical site infections and underwent reoperation before union. The overall complication rate was 25.1%, while the respective reintervention rate was 18.8%. In terms of functional outcomes, the mean OMAS score was 45, ranging from 20 to 70.

CONCLUSION

Tibiotalocalcaneal nailing can be considered as an acceptable less invasive option with good functional outcomes for the treatment of complex distal tibia and ankle fractures in frail patients with problematic local soft tissues.

Effect of humeral rotation on the reliability of radiographic measurements for proximal humerus fractures

BACKGROUND

There are concerns as to the reliability of proximal humerus radiographic measurements, particularly regarding the rotational position of the humerus when obtaining radiographs.

METHODS

Twenty-four patients with proximal humerus fractures fixed surgically with locked plates received postoperative anteroposterior radiographs with the humerus in neutral rotation and in 30° of internal and external rotation. Radiographic measurements for head shaft angle, humeral offset and humeral head height were performed in each humeral rotation position. Intra-class correlation coefficient was used to assess inter-rater and intra-rater reliability. Mean differences (md) in measurements between humeral positions was evaluated using one-way ANOVA.

RESULTS

Head shaft angle demonstrated good-to-excellent reliability; the highest estimates for inter-rater reliability (ICC: 0.85; 95% CI: 0.76, 0.94) and intra-rater reliability (ICC: 0.96; 95% CI: 0.93, 0.98) were achieved in neutral rotation. There were significant differences in measurement values between each rotational position, with mean head shaft angle of 133.1° in external rotation, and increasingly valgus measurements in neutral (md: 7.6°; 95% CI: 5.0, 10.3°; p < 0.001) and internal rotation (md: 26.4°; 95% CI: 21.8, 30.9°; p < 0.001). Humeral head height and humeral offset showed good-to-excellent reliability in neutral and external rotation, but poor inter-rater reliability in internal rotation. Humeral head height was significantly greater using internal compared to external rotation (md: 4.5 mm; 95% CI: 1.7, 7.3 mm; p = 0.002). Humeral offset was significantly greater in external compared to internal rotation (md: 4.6 mm; 95% CI: 2.6, 6.6 mm; p < 0.001).

CONCLUSIONS

Views of the humerus in neutral rotation and 30° of external rotation displayed superior reliability. Differences in radiographic measurement values, depending on humeral rotation views, can make for problematic correlations with patient outcome measures. Studies assessing radiographic outcomes following proximal humerus fractures should ensure standardized humeral rotation for obtaining anteroposterior shoulder radiographs, with neutral rotation and external rotation views likely yielding the most reliable results.

LEVEL OF EVIDENCE

Level IV.

Advances in Hand Therapy: Best Practice in Conservative Management of Proximal Phalangeal Fractures in Children

BACKGROUND

Proximal phalangeal fractures are one of the most commonly treated hand injuries in children. Conservative management of these fractures is often to splint for 5 weeks post injury, despite children presenting as clinically healed at 3 weeks post injury. Therefore, we investigated the effect of splinting for only 3 weeks in children who present with clinically healed proximal phalangeal fractures at 3 weeks compared with usual care.

METHODS

Participants (n=80, aged 10.3 ±2.5 years) presenting to the Hand Clinic of a tertiary Children's Hospital in Sydney, Australia, were randomly allocated into a Current Protocol and a New Protocol group. Following were the inclusion criteria: aged between 5 and 16 years; present with an non-displaced or minimally displaced and stable fracture; no surgical intervention; assessed as clinically healed at 3-week visit. The primary outcome measure was total active motion (TAM) of the injured digit compared with the contralateral digit (deg), at 5 weeks post injury. Secondary outcome measures were grip strength, and a parent-reported questionnaire. Statistical analysis used χ 2 test and the absolute difference described by a 90% CI. The New Protocol was considered noninferior if the 90% CI overlap was > 20% of the Current Protocol. Analysis was by intention to treat.

RESULTS

There was a 10% loss to follow up at 5 weeks (Current Protocol =4, New Protocol =4). All CIs between groups overlapped by >10%. TAM 90% CI for Current Protocol was 17.7 to 5.4 degrees and for the New Protocol was 4.7 to 1.6 degrees.

CONCLUSIONS

A change in practice is warranted to cease immobilization for children with conservatively managed proximal phalangeal fractures who present as clinically healed at 3 weeks. Therapist assessment of fracture healing is an appropriate indicator for intervention and can be utilized in a therapist-led model of care.

LEVEL OF EVIDENCE

Level 1-noninferiority randomized control trial with 2 parallel arms.

Ultrasound assessment of humeral shaft nonunion risk: a feasibility and proof of concept study

PURPOSE

To determine the feasibility and reliability of ultrasound in the assessment of humeral shaft fracture healing and estimate the accuracy of 6wk ultrasound in predicting nonunion.

METHODS

Twelve adults with a non-operatively managed humeral shaft fracture were prospectively recruited and underwent ultrasound scanning at 6wks and 12wks post-injury. Seven blinded observers evaluated sonographic callus appearance to determine intra- and inter-observer reliability. Nonunion prediction accuracy was estimated by comparing images for patients that united (n = 10/12) with those that developed a nonunion (n = 2/12).

RESULTS

The mean scan duration was 8 min (5-12) and all patients tolerated the procedure. At 6wks and 12wks, sonographic callus (SC) was present in 11 patients (10 united, one nonunion) and sonographic bridging callus (SBC) in seven (all united). Ultrasound had substantial intra- (weighted kappa: 6wk 0.75; 12wk 0.75) and inter-observer reliability (intraclass correlation coefficient: 6wk 0.60; 12wk 0.76). At 6wks, the absence of SC demonstrated sensitivity 50%, specificity 100%, positive predictive value (PPV) 100% and negative predictive value (NPV) 91% in nonunion prediction (overall accuracy 92%). The absence of SBC demonstrated sensitivity 100%, specificity 70%, PPV 40% and NPV 100% in nonunion prediction (overall accuracy 75%). Of three patients at risk of nonunion (Radiographic Union Score for HUmeral fractures < 8), one had SBC on 6wk ultrasound (that subsequently united) and the others had non-bridging/absent SC (both developed nonunion).

CONCLUSIONS

Ultrasound assessment of humeral shaft fracture healing was feasible, reliable and may predict nonunion. Ultrasound could be useful in defining nonunion risk among patients with reduced radiographic callus formation.

Experimental study on determining the degree of bone healing by wall thickness ratio analysis

To verify the reliability and accuracy of wall thickness ratio analysis to determine the degree of bone healing, fracture models were established with 6 beagles. X-ray, micro-CT, and CT scans were performed at 24 weeks. The healthy side and the affected side were used to simulate the three-dimensional geometric model after internal fixation, and the mesh was divided. The mean and median CT wall thickness values were obtained through the wall thickness analysis. X-ray, CT, micro-CT, and gross appearance were used to determine the degree of bone healing, which was compared with wall thickness analysis. There was a positive correlation between the average CT value and the median wall thickness. The correlation coefficient analysis of the median wall thickness ratio (R2) and healing index ratio (R3) showed a positive correlation. The results of the wall thickness ratio (R2) and the healing index ratio (R3) were used to determine bone healing, and the results were consistent with the results of the actual mechanical test and image analysis. The results of wall thickness ratio analysis were significantly correlated with the degree of bone healing. This method is simple, rapid, and practical to analyze and judge the degree of bone healing.

Follow-up non-attendance after long-bone fractures in a low-resource setting: a prospective study of predictors and interventions to increase attendance rates

BACKGROUND

While the majority of traumatic injuries occur in low- and middle-income countries, the published literature comes chiefly from high-income countries due to poor follow-up. Clinical and radiographic post-surgical trauma follow-up is essential to high-quality research and objective monitoring for healing and/or complications. This study aimed to identify the predictors of follow-up non-attendance in a low-resource setting and investigate the extent to which interventional efforts based on mobile phone technology (MPT) and home visits improved the follow-up rates for fractures treated with SIGN nails.

METHODS

This was a prospective study of 594 patients with long-bone fractures. Socio-demographic (e.g. age, gender, marital status, education level, etc.) and clinical (e.g. fracture type, concomitant injuries, comorbidity, etc.) data were collected on each patient. Before discharge, the importance of follow-up was explained to patients and their relations. They were encouraged to attend even if they felt well. Their residential addresses and telephone numbers were validated and securely stored. Patients who missed their appointments were contacted by phone. Those who failed to honour 2 or 3 rescheduled appointments were visited in their home. The patients were divided into those who returned for the primarily scheduled follow-up without prompting (volition group) and those who did not come (non-attenders). Univariate analyses and binary logistic regression were conducted to determine the significant predictors of non-attendance.

RESULTS

The proportion of patients in the volition group reduced from 96.1% at 6 weeks to 53.0% at 12 weeks and 39.2% at 6 months. However, interventional efforts increased these values to 98.5%, 92.5%, and 72.4% respectively. Walking unaided before the primarily scheduled 12-week appointment was the major reason for not attending the follow-up. Education, occupation, post-operative length of hospital stay (PLOS) and infection were significantly associated with non-attendance but younger age, long distances from the hospital, being separated or divorced, difficulty paying the in-patient care bill, closed fracture, having no (or a non-limb) concomitant injury, achieving painless weight bearing ≤ 6 weeks post-operatively and needing no additional surgery were independent predictors of non-attendance.

CONCLUSIONS

Our study sheds light on the predictors of follow-up non-attendance and demonstrates how interventional efforts improved attendance rates in a low-resource setting. In addition, efforts that better the socio-economic status of people such as more-encompassing health insurance coverage and greater work flexibility can improve the follow-up attendance rates.

Novel approaches to correlate computerized tomography imaging of bone fracture callus to callus structural mechanics

Estimating the mechanical properties of bone in vivo without destructive testing would be useful for research and clinical orthopedic applications. Micro-computerized tomography (μCT) imaging can provide quantitative, high-resolution 3D representations of bone morphology and is generally the basis from which bone mechanical properties are non-destructively estimated. The goal of this study was to develop metrics using qualitative and quantitative aspects of bone microarchitecture derived from μCT imaging to estimate the mechanical integrity of bone fracture calluses. Mechanical testing data (peak torque) and μCT image data from 12 rat femur fractures were collected at 4 weeks after fracture. MATLAB was used to analyze the callus μCT imaging data which were then correlated to the empirically determined peak torque of the callus. One metric correlated Z-rays, linear contiguities of voxels running parallel to the neutral axis of the femur and through the fracture callus, to peak torque. Other metrics were based on voxel linkage values (LVs), which is a novel measurement defined by the number of voxels surrounding a given voxel (ranging from 1 to 27) that are all above a specified threshold. Linkage values were utilized to segment the callus and compute healing scores (termed eRUST) based on the modified Radiographic Union Score for Tibial fractures (mRUST). Linkage values were also used to calculate linked bone areas (LBAs). All metrics positively correlated with peak torque, yielding correlations of determination (R2) of 0.863 for eRUST, 0.792 for Z-ray scoring, and 0.764 for a normalized Linked Bone Area metric. These novel metrics appear to be promising approaches for extrapolating fracture callus structural properties from bone microarchitecture using objective analytical methods and without resorting to computationally complex finite element analyses.

Wall thickness analysis method for judging the degree of lower extremity long bone healing

To evaluate the possibility of judging the degree of bone healing by wall thickness analysis provide reference for quantitative analysis of bone healing. Patients with lower limb fracture from April 2014 to October 2019 were recruited and divided into bone healing (group A), poor bone healing (group B), and nonunion (group C). Models were built in Mimics 20.0 with DICOM 3.0 data obtained from patient's CT. Three-dimensional geometric models of unaffected limb and affected limb after simulated removal of internal fixation were established, corresponding to basic phase and simulated phase, respectively. Wall thickness analysis was performed to obtain median wall thickness after meshing. R2 (median wall thickness ratio), R4 (CT value ratio), and R5 (healing index ratio) were obtained by calculating the ratio of each value in simulated phase to that in basic phase. Receiver operating characteristic curve analysis was used to evaluate the ability of Wall Thickness Analysis to indicate fracture healing. 112 CT scans of 79 patients were included in the study. The frequency of categorization in groups A, B, and C was 49, 37 and 26, respectively. The median R2 in groups A, B, and C was 0.91, 0.80, and 0.67, respectively (group A > group B > group C, all P < 0.05). The best cutoff point for R2 in predicting bone healing was 0.84, and predicting bone nonunion was 0.74. The Wall Thickness Analysis can be used to quantitatively evaluate fracture healing state, with median wall thickness ratio as a more intuitive and reliable judgment index.

Antibiotic cement-coated rigid locked nails in infected femoral and tibial nonunion. Reoperation rates of commercial versus custom-made nails

INTRODUCTION

The objective of this study is to assess bone union, infection control, and reoperation rates in a series of patients with infected femoral or tibial nonunion treated with antibiotic-cement-coated rigid nails and to compare the results obtained with custom-made nails versus commercial nails.

METHODS

We retrospectively analyzed a series of consecutive patients with infected nonunion of the femur or the tibia treated with antibiotic-cement-coated rigid nails between January 2010 and 2020. We assessed patients' distinctive characteristics, initial injury, type of nail used (custom-made nail with vancomycin or commercial nail with gentamicin), success rate (bone union + infection control), reoperation rate, and failure rate. Comparative analyses were conducted between reoperated and non-reoperated patients regarding the type of nail used. A multivariate regression analysis was performed to assess the risk variables that impacted reoperation rates.

RESULTS

We included 54 patients with 22 (40.74%) infected femoral nonunions and 32 (59.25%) tibial nonunions, who were treated with 38 (70.37%) custom-made antibiotic-cement coated nails and 16 (29.62%) commercial nails. Bone union and infection control were achieved in 51 (94.44%) cases. The reoperation rate was 40.74% (n = 22), and the failure rate was 5.55% (n = 3). The use of custom-made nails was associated with a higher risk of reoperation (Odds Ratio 4.71; 95% Confidence Interval 1.10 - 20.17; p = 0.036).

CONCLUSION

Antibiotic-cement-coated nails reached a 94.44% success rate. Nails manufactured in the OR coated with vancomycin cement were associated with a higher risk of reoperation than commercial nails loaded with gentamicin cement.

LEVEL OF EVIDENCE

III comparative, observational, non-randomized.

The double-plate fixation technique prevents varus collapse in AO type C3 supra-intercondylar fracture of the distal femur

INTRODUCTION

Varus collapse followed by osteosynthesis for distal femoral fractures with conventional implants has been well documented but is seldom mentioned in fractures managed with locking plates. The purpose of this study was to assess the incidence of varus collapse after treating complex supra-intercondylar fractures of the distal femur (AO type C3) using a Single Plate (SP) or Double Plate (DP) fixation technique.

MATERIALS AND METHODS

We retrospectively reviewed 357 patients with distal femoral fractures who were treated at our hospital between 2006 and 2017. After excluding cases of infection, malignancy, periprosthetic fracture, revision surgery, pediatric fracture, and extra-articular fracture, 54 patients were included in the study. All demographic data and radiological and clinical outcomes were reviewed and analyzed.

RESULTS

There were 54 patients enrolled into this study with age from 15 to 85 years old (mean 41.6, SD = 19.9), and 32 of them were open fractures (59%). The patients were further divided into either an SP (n = 15) or a DP group (n = 39). Demographics, including age, sex, injury severity score, and open fracture type, were all compatible between the two groups. The overall nonunion rate was 25.9% (n = 14; 6 from the SP and 8 from the DP group; p = 0.175). The varus collapse rate was 9.3% (n = 5; 4 from the SP and 1 from the DP group (p = 0.018).

CONCLUSIONS

The varus collapse rate after osteosynthesis with a single lateral locking plate could be as high as 26.7% in AO type C3 fractures of the distal femur, which would be decreased to 2.6% by adding a medial buttress plate. Surgeons should consider DP fixation to avoid varus collapse in severely comminuted complete intra-articular fractures of the distal femur.

Effect of fracture level on the residual fracture gap during tibial intramedullary nailing for tibial shaft fractures

INTRODUCTION

The development of fracture gap during intramedullary nailing in tibial fractures is associated with poor fracture fragment contact and increased time to union and complications. This study aimed to evaluate the effect of the fracture level in the development of the fracture gap and the effect of the fracture gap on pain, radiologic and functional outcomes, and complication rate.

MATERIAL AND METHOD

A total of 45 patients who underwent reamed intramedullary nailing due to closed transverse or short oblique tibial shaft fractures were divided into the proximal fracture group and the distal fracture group. The correlations between the visual analog scale (VAS) score, modified radiograph union score for tibias (RUST), and postoperative 1-year lower extremity functional scale scores, residual fracture gap, and time to union were evaluated.

RESULTS

The mean fracture gap amounts in the immediate postoperative anteroposterior and lateral radiographs were 5.6 ± 1.7 and 6.0 ± 1.7 mm in proximal fractures and 0.3 ± 2.4 mm and 0.4 ± 2.3 mm in distal fractures, respectively (p < 0.001 and p < 0.001, respectively). The mean time to union was 21.9 ± 2.9 weeks in the proximal fracture group and 16.7 ± 2.4 weeks in the distal fracture group (p < 0.000). The residual fracture gap amount significantly correlated with the level of fracture (r = 0.811, p < 0.001).

DISCUSSION

Tibial shaft fractures proximal to the isthmus level tend to develop significantly larger fracture gaps than distal fractures. It is associated with increased time to union and radiographic union scores as well as slightly higher complication and reoperation rates.

Bone Healing of Critical-Sized Femoral Defects in Rats Treated with Erythropoietin Alone or in Combination with Xenograft

Critical-size bone defect models are the standard in studies of the osteogenic potential of biomaterials. The present investigation aimed to evaluate the ability of recombinant human erythropoietin (EPO) to induce trabecular bone healing either alone or combined with a xenograft in a rat femoral critical-size defect model. Five-mm bone defects were created in the femoral diaphysis of fifty-six skeletally mature male Wistar albino rats. The animals were divided into six groups: one control group and five experimental groups. The defects in the control group were left empty, whereas an absorbable collagen cone soaked either with saline or erythropoietin (alone or in combination with xenograft) was placed in locally treated groups. The systemic treatment group received EPO subcutaneously. Bone formation was objectively evaluated through radiography, osteodensitometry and histological examination on post-operative days 30 and 90. The results demonstrate that EPO, locally applied on a collagen scaffold, was capable of inducing bone healing, whereas the single systemically administered high EPO dose had only an insignificant effect on bone formation. The combination of EPO with a bone substitute under the form of cancellous granules resulted in more rapid integration between the xenograft and host bone.

Non-destructive characterization of bone mineral content by machine learning-assisted electrochemical impedance spectroscopy

Continuous quantitative monitoring of the change in mineral content during the bone healing process is crucial for efficient clinical treatment. Current radiography-based modalities, however, pose various technological, medical, and economical challenges such as low sensitivity, radiation exposure risk, and high cost/instrument accessibility. In this regard, an analytical approach utilizing electrochemical impedance spectroscopy (EIS) assisted by machine learning algorithms is developed to quantitatively characterize the physico-electrochemical properties of the bone, in response to the changes in the bone mineral contents. The system is designed and validated following the process of impedance data measurement, equivalent circuit model designing, machine learning algorithm optimization, and data training and testing. Overall, the systematic machine learning-based classification utilizing the combination of EIS measurements and electrical circuit modeling offers a means to accurately monitor the status of the bone healing process.

Comparison of supraclavicular nerve injuries after clavicle mid-shaft surgery via minimally invasive plate osteosynthesis versus open reduction and internal fixation

INTRODUCTION

Only a few previous studies have evaluated the factors related to supraclavicular nerve (SCN) injury after clavicle mid-shaft fracture surgery. We analyzed the frequency and risk factors for SCN injury after clavicle mid-shaft fracture surgery via open reduction and internal fixation (ORIF) versus minimally invasive plate osteosynthesis (MIPO) MATERIALS AND METHODS: We retrospectively reviewed the cases from 59 patients who had undergone surgery for clavicle mid-shaft fractures between January 2018 and April 2019. Twenty-nine patients had undergone ORIF and 30 had undergone MIPO. The frequency of SCN injury in the two groups was evaluated, and preoperative patient demographics (age, sex, body mass index, smoking, alcohol, diabetes mellitus, and trauma mechanism), and radiological parameters (fracture displacement and shortening) were measured and evaluated as risk factors for SCN injury. When neurological symptoms, such as numbness, were present on the anterior chest wall or at the incision site, electromyography (EMG) was conducted.

RESULTS

Neurological symptoms were present in 12 patients. Numbness in the anterior upper chest around the incision site was present in eight and four patients who underwent ORIF and MIPO, respectively (p < 0.001). Furthermore, fracture displacement evaluated on preoperative three-dimensional computed tomography was significantly associated with the occurrence of SCN injury in patients who underwent MIPO (odds ratio, 1.038; 95% confidence interval, 1.001-1.077; p = 0.047). Although EMG was conducted in all patients with SCN injury, peripheral neuropathy was not found in any cases.

CONCLUSIONS

SCN injury, which is a possible complication of clavicle mid-shaft fracture surgery, occurred significantly less frequently in MIPO than in ORIF. In MIPO, greater preoperative fracture displacement was associated with a higher risk of SCN injury. Additional studies are required to reach a consensus regarding accurate methods to evaluate SCN injuries.

LEVEL OF EVIDENCE

IV, case series, treatment study.

Routine fixation of humeral shaft fractures is cost-effective

Aims

The primary aim was to estimate the cost-effectiveness of routine operative fixation for all patients with humeral shaft fractures. The secondary aim was to estimate the health economic implications of using a Radiographic Union Score for HUmeral fractures (RUSHU) of < 8 to facilitate selective fixation for patients at risk of nonunion.

Methods

From 2008 to 2017, 215 patients (mean age 57 yrs (17 to 18), 61% female (n = 130/215)) with a nonoperatively managed humeral diaphyseal fracture were retrospectively identified. Union was achieved in 77% (n = 165/215) after initial nonoperative management, with 23% (n = 50/215) uniting after surgery for nonunion. The EuroQol five-dimension three-level health index (EQ-5D-3L) was obtained via postal survey. Multiple regression was used to determine the independent influence of patient, injury, and management factors upon the EQ-5D-3L. An incremental cost-effectiveness ratio (ICER) of < £20,000 per quality-adjusted life-year (QALY) gained was considered cost-effective.

Results

At a mean of 5.4 yrs (1.2 to 11.0), the mean EQ-5D-3L was 0.736 (95% confidence interval (CI) 0.697 to 0.775). Adjusted analysis demonstrated the EQ-5D-3L was inferior among patients who united after nonunion surgery (β = 0.103; p = 0.032). Offering routine fixation to all patients to reduce the rate of nonunion would be associated with increased treatment costs of £1,542/patient, but would confer a potential EQ-5D-3L benefit of 0.120/patient over the study period. The ICER of routine fixation was £12,850/QALY gained. Selective fixation based on a RUSHU < 8 at six weeks post-injury would be associated with reduced treatment costs (£415/patient), and would confer a potential EQ-5D-3L benefit of 0.335 per ‘at-risk patient’.

Conclusion

Routine fixation for patients with humeral shaft fractures to reduce the rate of nonunion observed after nonoperative management appears to be a cost-effective intervention at five years post-injury. Selective fixation for patients at risk of nonunion based on their RUSHU may confer even greater cost-effectiveness, given the potential savings and improvement in health-related quality of life. Cite this article: Bone Jt Open 2022;3(7):566–572.

Continuous Implant Load Monitoring to Assess Bone Healing Status—Evidence from Animal Testing

Background and Objectives: Fracture healing is currently assessed through qualitative evaluation of radiographic images, which is highly subjective in nature. Radiographs can only provide snapshots in time, which are limited due to logistics and radiation exposure. We recently proposed assessing the bone healing status through continuous monitoring of the implant load, utilizing an implanted sensor system, the Fracture Monitor. The device telemetrically transmits statistically derived implant parameters via the patient’s mobile phone to assist physicians in diagnostics and treatment decision-making. This preclinical study aims to systematically investigate the device safety and performance in an animal setting. Materials and Methods: Mid-shaft tibial osteotomies of different sizes (0.6–30 mm) were created in eleven Swiss mountain sheep. The bones were stabilized with either a conventional Titanium or stainless-steel locking plate equipped with a Fracture Monitor. Data were continuously collected over the device’s lifetime. Conventional radiographs and clinical CT scans were taken longitudinally over the study period. The radiographs were systematically scored and CTs were evaluated for normalized bone volume in the defect. The animals were euthanized after 9 months. The sensor output was correlated with the radiologic parameters. Tissue samples from the device location were histologically examined. Results: The sensors functioned autonomously for 6.5–8.4 months until energy depletion. No macroscopic or microscopic adverse effects from device implantation were observed. The relative implant loads at 4 and 8 weeks post-operation correlated significantly with the radiographic scores and with the normalized bone volume metric. Conclusions: Continuous implant load monitoring appears as a relevant approach to support and objectify fracture healing assessments and carries a strong potential to enable patient-tailored rehabilitation in the future.

Factors Associated with Patient-Reported Outcomes Following a Humeral Shaft Fracture: Nonunion Results in a Poorer Outcome Despite Union after Surgical Fixation

OBJECTIVES

The primary aim was to assess patient-reported outcomes ≥1 year following a humeral diaphyseal fracture. The secondary aim was to compare outcomes of patients who united after initial management (operative/nonoperative) with those who united after nonunion fixation (NU-ORIF).

DESIGN

Retrospective.

SETTING

University teaching hospital.

PATIENTS AND INTERVENTION

From 2008 to 2017, 291 patients [mean age, 55 years (17-86 years), 58% (n = 168/291) female] were available to complete an outcomes survey. Sixty-four (22%) were initially managed operatively and 227 (78%) nonoperatively. After initial management, 227 (78%) united (n = 62 operative, n = 165 nonoperative), 2 had a delayed union (both nonoperative), and 62 (21%) had a nonunion (n = 2 operative, n = 60 nonoperative). Fifty-two patients (93%, n = 52/56) united after NU-ORIF.

MAIN OUTCOME MEASURES

QuickDASH, EuroQol-5 Dimension (EQ-5D)/EuroQol-Visual Analogue Scale (EQ-VAS), 12-item Short Form Physical (PCS) and Mental Component Summary (MCS).

RESULTS

At a mean of 5.5 years (range, 1.2-11.0 years) postinjury, the mean QuickDASH was 20.8, EQ-5D was 0.730, EQ-VAS was 74, PCS was 44.8 and MCS was 50.2. Patients who united after NU-ORIF reported worse function (QuickDASH, 27.9 vs. 17.6; P = 0.003) and health-related quality of life (HRQoL; EQ-5D, 0.639 vs. 0.766; P = 0.008; EQ-VAS, 66 vs. 76; P = 0.036; PCS, 41.8 vs. 46.1; P = 0.036) than those who united primarily. Adjusting for confounders, union after NU-ORIF was independently associated with a poorer QuickDASH (difference, 8.1; P = 0.019) and EQ-5D (difference, -0.102; P = 0.028).

CONCLUSIONS

Humeral diaphyseal union after NU-ORIF resulted in poorer patient-reported outcomes compared with union after initial management. Targeting early operative intervention to at-risk patients may mitigate the potential impact of nonunion on longer-term outcome.

LEVEL OF EVIDENCE

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

Cortical allograft strut augmented with platelet-rich plasma for the treatment of long bone non-union in lower limb- a pilot study

Background

The autogenous iliac bone graft is the first choice of surgical treatment for long bone non-union. However, many factors limit the use of autogenous bone, such as insufficient bone harvest and complications in the donor site. This study aimed to pilot-test the effectiveness of the cortical allograft strut augmented with Platelet-rich plasma (PRP) on long bone non-union in the lower limb.

Method

This study was a one-armed pilot trial, with thirteen men and four women patients scheduled for surgery. Revision surgery for managing long bone non-union included debridement, internal fixation of the cortical allograft strut, and adding PRP in the fracture site. After surgery, outcome measurements of healing rate, healing time, the incidence of revision, and complications, were assessed at least one-year follow-up.

Results

Fourteen of seventeen participants completed all follow-ups. The mean age of 14 patients was 35.9 years (range, 18–56 years), and the mean BMI was 22.44 ± 1.53 kg/m². All nonunions united after the operation. The mean healing time was 4.6 ± 0.7 months. There was no revision or complication.

Conclusion

Cortical allograft strut augmented with PRP led to healing long bone non-union in the lower limb. More clinical research is required before widespread use.

The diagnostic performance of ultra-low-dose 320-row detector CT with different reconstruction algorithms on limb joint fractures in the emergency department

BACKGROUND

The aim of the study was to evaluate whether ultra-low-dose computed tomography (ULD-CT) could replace conventional-dose CT (CD-CT) for diagnosis of acute wrist, ankle, knee, and shoulder fractures in emergency departments (ED).

METHODS

We developed CD-CT and ULD-CT scanning schemes for the various joints of the four limbs and scanned emergency patients prospectively. When performing CD-CT, a conventional bone reconstruction algorithm was used, while ULD-CT used both soft tissue and bone algorithms. A five-point scale was used to evaluate whether ULD-CT image quality affected surgical planning. The image quality and diagnostic performance of different types of scanned and reconstructed images for diagnosing fractures were evaluated and compared. Effective radiation dose of each group was calculated.

RESULTS

Our study included 56 normal cases and 185 fracture cases. The combination of bone and soft tissue algorithms on ULD-CT can improve diagnostic performance, such that on ULD-CT, the sensitivity improved from 96.7% to 98.9%, specificity from 98.2% to 100%, positive predictive value from 99.4% to 100%, negative predictive value from 90.2% to 96.6% and diagnostic accuracy ranged from 97.5% to 99.1%. There were no statistically significant differences between ULD-CT and CD-CT on diagnostic performance (p values, 0.40-1.00). The radiation doses for ULD-CT protocols were only 3.0-7.7% of those for CD-CT protocols (all p < 0.01).

CONCLUSIONS

In the emergency department, the 320-row detector ULD-CT could replace CD-CT in the diagnosis of limb joint fractures. The combination of bone algorithm with soft tissue algorithm reconstruction can further improve the image quality and diagnostic performance.

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.

Extracorporeal Shockwave Therapy in the Treatment of Nonunion in Long Bones: A Systematic Review and Meta-Analysis

Background: Nonunion is one of the most challenging problems in the field of orthopedics. The aim of this study was to perform a systematic review of the literature to evaluate the effectiveness of extracorporeal shockwave therapy (ESWT) in the treatment of nonunion in long bones. Methods: We conducted a search of three databases (PubMed, Scopus, and Web of Science) and found 646 total publications, of which 23 met our inclusion criteria. Results: Out of 1200 total long bone nonunions, 876 (73%) healed after being treated with ESWT. Hypertrophic cases achieved 3-fold higher healing rates when compared to oligotrophic or atrophic cases (p = 0.003). Metatarsal bones were the most receptive to ESWT, achieving a healing rate of 90%, followed by tibiae (75.54%), femurs (66.9%) and humeri (63.9%). Short periods between injury and treatment lead to higher healing rates (p < 0.02). Conversely, 6 months of follow-up after the treatment appears to be too brief to evaluate the full healing potential of the treatment; several studies showed that healing rates continued to increase at follow-ups beyond 6 months after the last ESWT treatment (p < 0.01). Conclusions: ESWT is a promising approach for treating nonunions. At present, a wide range of treatment protocols are used, and more research is needed to determine which protocols are the most effective.

Return to work and sport after a humeral shaft fracture

Aims

The primary aim of this study was to determine the rates of return to work (RTW) and sport (RTS) following a humeral shaft fracture. The secondary aim was to identify factors independently associated with failure to RTW or RTS.

Methods

From 2008 to 2017, all patients with a humeral diaphyseal fracture were retrospectively identified. Patient demographics and injury characteristics were recorded. Details of pre-injury employment, sporting participation, and levels of return post-injury were obtained via postal questionnaire. The University of California, Los Angeles (UCLA) Activity Scale was used to quantify physical activity among active patients. Regression was used to determine factors independently associated with failure to RTW or RTS.

Results

The Work Group comprised 177 patients in employment prior to injury (mean age 47 years (17 to 78); 51% female (n = 90)). Mean follow-up was 5.8 years (1.3 to 11). Overall, 85% (n = 151) returned to work at a mean of 14 weeks post-injury (0 to 104), but only 60% (n = 106) returned full-time to their previous employment. Proximal-third fractures (adjusted odds ratio (aOR) 4.0 (95% confidence interval (CI) 1.2 to 14.2); p = 0.029) were independently associated with failure to RTW. The Sport Group comprised 182 patients involved in sport prior to injury (mean age 52 years (18 to 85); 57% female (n = 104)). Mean follow-up was 5.4 years (1.3 to 11). The mean UCLA score reduced from 6.9 (95% CI 6.6 to 7.2) before injury to 6.1 (95% CI 5.8 to 6.4) post-injury (p < 0.001). There were 89% (n = 162) who returned to sport: 8% (n = 14) within three months, 34% (n = 62) within six months, and 70% (n = 127) within one year. Age ≥ 60 years was independently associated with failure to RTS (aOR 3.0 (95% CI 1.1 to 8.2); p = 0.036). No other factors were independently associated with failure to RTW or RTS.

Conclusion

Most patients successfully return to work and sport following a humeral shaft fracture, albeit at a lower level of physical activity. Patients aged ≥ 60 yrs and those with proximal-third diaphyseal fractures are at increased risk of failing to return to activity.

Cite this article: Bone Jt Open 2022;3(3):236–244.

Modal Frequencies Associations with Musculoskeletal Components of Human Legs for Extracorporeal Bone Healing Assessment Based on a Vibration Analysis Approach

Reliable and quantitative assessments of bone quality and fracture healing prompt well-optimised patient healthcare management and earlier surgical intervention prior to complications of nonunion and malunion. This study presents a clinical investigation on modal frequencies associations with musculoskeletal components of human legs by using a prototype device based on a vibration analysis method. The findings indicated that the first out-of-plane and coupled modes in the frequency range from 60 to 110 Hz are associated with the femur length, suggesting these modes are suitable quantitative measures for bone evaluation. Furthermore, higher-order modes are shown to be associated with the muscle and fat mass of the leg. In addition, mathematical models are formulated via a stepwise regression approach to determine the modal frequencies using the measured leg components as variables. The optimal models of the first modes consist of only femur length as the independent variable and explain approximately 43% of the variation of the modal frequencies. The subsequent findings provide insights for further development on utilising vibration-based methods for practical bone and fracture healing monitoring.

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.

Teriparatide and pelvic fracture healing: a phase 2 randomized controlled trial

Pelvic fracture patients were randomized to blinded daily subcutaneous teriparatide (TPTD) or placebo to assess healing and functional outcomes over 3 months. With TPTD, there was no evidence of improved healing by CT or pain reduction; however, physical performance improved with TPTD but not placebo (group difference p < 0.03).

INTRODUCTION

To determine if teriparatide (20 μg/day; TPTD) results in improved radiologic healing, reduced pain, and improved functional outcome vs placebo over 3 months in pelvic fracture patients.

METHODS

This randomized, placebo-controlled study enrolled 35 patients (women and men >50 years old) within 4 weeks of pelvic fracture and evaluated the effect of blinded TPTD vs placebo over 3 months on fracture healing. Fracture healing from CT images at 0 and 3 months was assessed as cortical bridging using a 5-point scale. The numeric rating scale (NRS) for pain was administered monthly. Physical performance was assessed monthly by Continuous Summary Physical Performance Score (based on 4 m walk speed, timed repeated chair stands, and balance) and the Timed Up and Go (TUG) test.

RESULTS

The mean age was 82, and >80% were female. The intention to treat analysis showed no group difference in cortical bridging score, and 50% of fractures in TPTD-treated and 53% of fractures in placebo-treated patients were healed at 3 months, unchanged after adjustment for age, sacral fracture, and fracture displacement. Median pain score dropped significantly in both groups with no group differences. Both CSPPS and TUG improved in the teriparatide group, whereas there was no improvement in the placebo group (group difference p < 0.03 for CSPPS at 2 and 3 months).

CONCLUSION

In this small randomized, blinded study, there was no improvement in radiographic healing (CT at 3 months) or pain with TPTD vs placebo; however, there was improved physical performance in TPTD-treated subjects that was not evident in the placebo group.

Contrast-Enhanced Ultrasound: A Viable Diagnostic Tool in Predicting Treatment Failure after Non-union Revision Surgery for Upper- and Lower-Limb Non-unions

Non-unions remain a major complication in the treatment of long-bone fractures and affect quality of life considerably. Both early detection and treatment of non-unions are essential to secure subsequent fracture union. Sufficient vascularization plays a key role in the healing process. The aim of this prospective study was to quantify the microperfusion within non-unions by means of contrast-enhanced ultrasound (CEUS) as early as 12 wk after non-union surgery and to examine the prognostic capability of CEUS in predicting treatment failure. Among 112 patients who had undergone non-union surgery, consolidation within 36 mo was achieved in 89 patients ("responders"), whereas 23 patients showed persistent non-unions ("non-responders") and required further surgery. CEUS quantification parameters such as peak enhancement, wash-in area under the curve and wash-in perfusion index revealed significantly higher perfusion levels in "responders" compared with "non-responders" (p < 0.05). Receiver operator characteristic curve analysis revealed that persistent fracture non-unions could be predicted with a sensitivity/specificity of 88.7%/72.2% in lower-limb non-unions and a sensitivity/specificity of 66.7%/100.0% in upper-limb non-unions. CEUS is a suitable diagnostic tool in predicting treatment failure as early as 12 wk after non-union surgery and should be integrated into the clinical routine when deciding on revision surgery at an early stage.

Effect of Bone Morphogenetic Protein-2 in the Treatment of Long Bone Non-Unions

Background: Delayed fracture healing continues to cause significant patient morbidity and an economic burden to society. Biological stimulation of non-unions includes application of recombinant bone morphogenetic protein-2 (rhBMP-2). However, rhBMP-2 use continues to be a matter of controversy as literature shows scarce evidence for treatment effectiveness. Questions: The objective of this study was to evaluate the effectiveness of rhBMP-2 treatment on long bone non-unions measuring union rate and time to union. Furthermore, we assess risk factors for treatment failure. Methods and patients: A total of 91 patients with non-unions of long bones were treated with rhBMP-2 (n = 72) or standard care without BMP (n = 19) at our institution. Patient characteristics, comorbidities, nicotine consumption, and complications were recorded. Bone healing was assessed by plane X-rays and clinical examination. Patients were followed up with for 24 months. Results: Overall, there was significantly faster bone healing after rhBMP-2 application compared to the no-BMP group (p < 0.001; HR = 2.78; 95% CI 1.4–5.6). Union rates differed significantly between rhBMP-2 compared to the no-BMP group (89% vs. 47%; p < 0.001). At the humerus, there was neither a significantly higher union rate in the rhBMP-2 (83%) compared to the no-BMP group (50%) (p = 0.26; n = 12) nor a faster bone healing with a median time of 9 months in both groups (HR = 2.01; 95% CI 0.49–8.61; p = 0.315). The 33 femora treated using rhBMP-2 healed significantly faster than 9 femora in the no-BMP group (HR = 2.93; 95% CI 1.00–8.4; p = 0.023) with significant differences in union rate with 85% and 44%, respectively (p = 0.022). Regarding tibia non-unions, 25 out of 27 (93%) healed with a median of 9 months after rhBMP-2 application with no significant difference in the no-BMP group (33%) in time to union (p = 0.097) but a significantly higher union rate (p = 0.039). There was no effect of comorbidities, age, sex, soft tissue damage, or nicotine use on time to union, union rate, or secondary interventions. Conclusion: Consistent with the literature, overall, significantly higher union rates with reduced time to union were achieved after rhBMP-2 application. Femoral and tibial non-unions in particular seem to profit from rhBMP-2 application.

Factors associated with humeral shaft nonunion

BACKGROUND

The primary aim was to identify patient and injury factors independently associated with humeral diaphyseal fracture nonunion after nonoperative management. The secondary aim was to determine the effect of management (operative/nonoperative) on nonunion.

METHODS

From 2008-2017, a total of 734 humeral shaft fractures (732 consecutive skeletally mature patients) were retrospectively identified from a trauma database. Follow-up was available for 663 fractures (662 patients, 90%) that formed the study cohort. Patient and injury characteristics were recorded. There were 523 patients (79%) managed nonoperatively and 139 (21%) managed operatively. Outcome (union/nonunion) was determined from medical records and radiographs.

RESULTS

The median age at injury was 57 (range 16-96) years and 54% (n = 359/662) were female. Median follow-up was 5 (1.2-74) months. Nonunion occurred in 22.7% (n = 119/524) of nonoperatively managed injuries. Multivariate analysis demonstrated preinjury nonsteroidal anti-inflammatory drugs (NSAIDs; odds ratio [OR] 20.58, 95% confidence interval [CI] 2.12-199.48; P = .009) and glenohumeral arthritis (OR 2.44, 95% CI 1.03-5.77; P = .043) were independently associated with an increased risk of nonunion. Operative fixation was independently associated with a lower risk of nonunion (2.9%, n = 4/139) compared with nonoperative management (OR for nonoperative/operative management 9.91, 95% CI 3.25-30.23; P < .001). Based on these findings, 5 patients would need to undergo primary operative fixation in order to avoid 1 nonunion.

CONCLUSIONS

Preinjury NSAIDs and glenohumeral arthritis were independently associated with nonunion following nonoperative management of a humeral diaphyseal fracture. Operative fixation was the independent factor most strongly associated with a lower risk of nonunion. Targeting early operative fixation to at-risk patients may reduce the rate of nonunion and the morbidity associated with delayed definitive management.

Non-union bone fractures

The human skeleton has remarkable regenerative properties, being one of the few structures in the body that can heal by recreating its normal cellular composition, orientation and mechanical strength. When the healing process of a fractured bone fails owing to inadequate immobilization, failed surgical intervention, insufficient biological response or infection, the outcome after a prolonged period of no healing is defined as non-union. Non-union represents a chronic medical condition not only affecting function but also potentially impacting the individual's psychosocial and economic well-being. This Primer provides the reader with an in-depth understanding of our contemporary knowledge regarding the important features to be considered when faced with non-union. The normal mechanisms involved in bone healing and the factors that disrupt the normal signalling mechanisms are addressed. Epidemiological considerations and advances in the diagnosis and surgical therapy of non-union are highlighted and the need for greater efforts in basic, translational and clinical research are identified.

Percutaneous administration of allogeneic bone-forming cells for the treatment of delayed unions of fractures: a pilot study

Background

Overall, 5–10% of fractures result in delayed unions or non-unions, causing major disabilities and a huge socioeconomic burden. Since rescue surgery with autologous bone grafts can cause additional challenges, alternative treatment options have been developed to stimulate a deficient healing process. This study assessed the technical feasibility, safety and preliminary efficacy of local percutaneous implantation of allogeneic bone-forming cells in delayed unions of long bone fractures.

Methods

In this phase I/IIA open-label pilot trial, 22 adult patients with non-infected delayed unions of long bone fractures, which failed to consolidate after 3 to 7 months, received a percutaneous implantation of allogeneic bone-forming cells derived from bone marrow mesenchymal stem cells (ALLOB; Bone Therapeutics) into the fracture site (50 × 10⁶ to 100 × 10⁶ cells). Patients were monitored for adverse events and need for rescue surgery for 30 months. Fracture healing was monitored by Tomographic Union Score (TUS) and modified Radiographic Union Score. The health status was evaluated using the Global Disease Evaluation (GDE) score and pain at palpation using a visual analogue scale. The presence of reactive anti-human leukocyte antigen (HLA) antibodies was evaluated.

Results

During the 6-month follow-up, three serious treatment-emergent adverse events were reported in two patients, of which two were considered as possibly treatment-related. None of the 21 patients in the per-protocol efficacy population needed rescue surgery within 6 months, but 2/21 (9.5%) patients had rescue surgery within 30 months post-treatment. At 6 months post-treatment, an improvement of at least 2 points in TUS was reached in 76.2% of patients, the GDE score improved by a mean of 48%, and pain at palpation at the fracture site was reduced by an average of 61% compared to baseline. The proportion of blood samples containing donor-specific anti-HLA antibodies increased from 8/22 (36.4%) before treatment to 13/22 (59.1%) at 6 months post-treatment, but no treatment-mediated allogeneic immune reactions were observed.

Conclusion

This pilot study showed that the percutaneous implantation of allogeneic bone-forming cells was technically feasible and well tolerated in patients with delayed unions of long bone fractures. Preliminary efficacy evidence is supporting the further development of this treatment.

Trial registration

NCT02020590. Registered on 25 December 2013. ALLOB-DU1, A pilot Phase I/IIa, multicentre, open proof-of-concept study on the efficacy and safetyof allogeneic osteoblastic cells (ALLOB®) implantation in non-infected delayed-union fractures.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02432-4.

Combining a Vascular Bundle and 3D Printed Scaffold with BMP-2 Improves Bone Repair and Angiogenesis

Vascularization is currently considered the biggest challenge in bone tissue engineering due to necrosis in the center of large scaffolds. We established a new expendable vascular bundle model to vascularize a three-dimensional printed channeled scaffold with and without bone morphogenetic protein-2 (BMP-2) for improved healing of large segmental bone defects. Bone formation and angiogenesis in an 8 mm critical-sized bone defect in the rat femur were significantly promoted by inserting a bundle consisting of the superficial epigastric artery and vein into the central channel of a large porous polycaprolactone scaffold. Vessels were observed sprouting from the vascular bundle inserted in the central tunnel. Although the regenerated bone volume in the group receiving the scaffold and vascular bundle was similar to that of the healthy femur, the rate of union of the group was not satisfactory (25% at 8 weeks). BMP-2 delivery was found to promote not only bone formation but also angiogenesis in the critical-sized bone defects. Both insertion of the vascular bundle alone and BMP-2 loading alone induced comparable levels of angiogenesis and when used in combination, significantly greater vascular volume was observed. These findings suggest a promising new modality of treatment in large bone defects. Level of Evidence: Therapeutic level I.

Squat and smile assessment in predicting healing of lower limb fractures fixed with a SIGN nail

BACKGROUND

Irrespective of the treatment method, union is the ultimate goal of any fracture treatment. However, nowadays, rather than the physician-based clinico-radiological methods, the patient-reported outcome measurements assessing their quality of life and function are gaining much popularity. This is specifically true in the part of the world where the patient needs almost complete degree of hip/knee flexion - for social, cultural, religious or occupational reason(s). The ability to squat can assess the mobility and stability of joints and thus the quality of squatting is a proxy reflection of the functional outcome after fixation of lower limb fracture. Thus, we studied to determine the inter-observer and intra-observer reliability of Radiographic Union Score for Tibia (RUST) and Squat and Smile (S & S) test in clinical photograph. We further calculated the sensitivity and specificity of S & S test in predicting healing of lower limb fracture fixed by intramedullary interlocking nail considering RUST as the gold standard.

METHODS

This was a retrospective study of prospectively collected data of solid Surgical Implant Generation Network (SIGN) intramedullary interlocking nailing from a single, university-based, high volume tertiary center where 56 consecutive adults with either tibial or femoral shaft fractures fixed with a SIGN nail within one year and not requiring any surgery till minimum of eighteen-month follow-up were included. Cases without either Anterior-Posterior (AP) view and/or Lateral (Lat.) view follow-up x-ray(s) or proper S & S clinical photograph (at least 1.5-year post fixation) were excluded. The x-rays (RUST criteria) and clinical photograph (S & S grading) were scored by two independent and blinded observers each and repeated after 1 month.

RESULTS

The overall intra-observer reliability was from 0.773 to 0.825 and inter-observer reliability from 0.635 to 0.757 for RUST scoring which was from 0.687 to 0.785 and from 0.301 to 0.650 respectively for S & S scoring. The sensitivity and specificity of S & S in predicting fracture healing were up to 82.22% and 63.64% respectively.

CONCLUSION

The S & S test is reliable to predict the healing of lower limb fracture fixed with an intramedullary nail. The test is more useful to determine healed fractures than to determine non-healed ones. (sensitivity being higher than specificity).

Evaluating reliability and validity of the modified radiographic union scale for tibia (mRUST) among North American and Tanzanian surgeons

Objectives

To determine the international reliability and validity of the modified Radiographic Union Scale for Tibial fracture (mRUST) scoring method for open tibial shaft fractures based on ratings of radiographs by separate groups of North American and Tanzanian surgeons.

Methods

Seven North American and 9 Tanzanian surgeons viewed 100 pairs of AP and lateral radiographs of open tibial shaft fractures obtained in Dar Es Salaam, Tanzania. The radiographs showed 25 patients' fractures at 4 time points postfracture after treatment with either external fixation or intramedullary nailing. Surgeons evaluated each fracture using the mRUST scoring method and indicated their confidence that the fracture was healed on a scale from 1 to 10. Reliability of mRUST was determined using inter-rater agreement among North American and Tanzanian surgeons. Validity was determined via analysis of correlation between mRUST scores and EQ-5D-3L index scores at each time point postfracture.

Results

mRUST scores demonstrated strong reliability overall (ICC = 0.64) as well as within each group of North American (ICC = 0.72) and Tanzanian (ICC = 0.69) surgeons. Reliability was stronger for external fixation than for intramedullary nailing cases. mRUST scores were significantly correlated with overall healing confidence at all time points and with quality of life at 6 months and 1 year postfracture. mRUST scores also correlated significantly with patients' quality of life scores (EQ-5D index) at 6 months and 1 year postfracture.

Conclusion

North American and Tanzanian surgeons exhibited strong agreement in rating open tibial shaft fractures. Using mRUST scores is a valid means of assessing radiographic healing of tibial fractures in austere environments like Tanzania.

The use of low intensity pulsed ultrasound in the foot and ankle

Low intensity pulsed ultrasound (LIPUS) therapy has demonstrated clinical effectiveness in achieving union in a variety of fracture situations.Few studies have investigated the effectiveness of LIPUS therapy in foot and ankle surgery.The overall rate of union in all published studies relating to the use of LIPUS in a variety of foot and ankle fracture and fusion situations is 95%.Some studies suggest lower healing rates (~ 67%) when LIPUS therapy is used to treat hindfoot fusion nonunion.A well-powered, high-quality, randomized controlled trial is needed to demonstrate the clinical and cost effectiveness of LIPUS therapy in foot and ankle surgery. Cite this article: EFORT Open Rev 2021;6:217-224. DOI: 10.1302/2058-5241.6.200045.

Measuring Lateral Screw Protuberance Is a Clinically Accurate Method for Quantifying Femoral Neck Shortening

OBJECTIVES

The purpose of this study is to compare the reliability and accuracy of the screw protuberance method (SPM) and overlay method (OM) for measuring femoral neck shortening on anterior-posterior (AP) radiographs. The secondary aim is to investigate the changes in reliability and accuracy with varying femoral rotation.

METHODS

Radio-opaque femur sawbone models were fitted with either 3 cancellous screws or a sliding hip screw implant. Anterior-posterior radiographs were obtained using C-arm fluoroscopy with femoral neck shortening up to 15 mm and with the femoral shaft in 30 degrees of internal rotation to 30 degrees of external rotation (ER). Four observers measured femoral neck shortening at 2 time points. Intraobserver and interobserver reliability were calculated using the intraclass coefficient. Accuracy was analyzed through a Bland-Altman agreement statistic stratified by femoral rotation.

RESULTS

Both measurement techniques displayed excellent reliability, regardless of femoral rotation or implant. There was a significant difference in femoral neck shortening measurements with rotation for both the OM (P < 0.001) and SPM (P < 0.001). Both methods are accurate within 1 mm of the actual magnitude of shortening from 30-degree internal rotation to 15-degree ER. At 30-degree ER, shortening was underestimated by -2.10 mm using the OM (95% confidence interval, -2.43 to -1.76; P < 0.01) and by -1.64 mm using the SPM (95% confidence interval, -1.83 to -1.45; P < 0.01).

CONCLUSION

This study demonstrates that both the OM and SPM are accurate and reliable assessments for femoral neck shortening; however, both methods are sensitive to extreme ER. Given the simplicity of the SPM technique, it may have increased utility for pragmatic research studies.

Improved diagnostic confidence in evaluating bone non-union using virtual monochromatic dual-energy CT

PURPOSE

The aim of this study was to determine whether virtual monochromatic dual-energy CT imaging improves the evaluation of suspected non-union of the appendicular skeleton treated with titanium or stainless steel intramedullary nails and plates.

METHOD

Forty-one patients with a clinical suspected non-union with hardware in place were included and scanned on a dual-source CT-scanner using 100/Sn150kVp. Images including titanium hardware were extracted at 130 keV. Images including stainless steel hardware were extracted at 150 keV. Monochromatic 70 keV images served as reference. Non-union confirmed during revision surgery was used as gold standard. A musculoskeletal radiologist and orthopedic trauma surgeon evaluated images on image quality, degree and location of consolidation, non-union type and diagnostic confidence.

RESULTS

Likert scores with respect to image quality improved from 0.88 to 1.83 (p < 0.001) in high (130 and 150) keV images. High keV images reduced the number of false negative non-unions based on consolidation grade with 5% (p = 0.283). Agreement between observers regarding location of consolidation and non-union type did not improve in 130 and 150 keV images. Diagnostic confidence improved from 1.43 to 2.37 in high keV images compared to 70 keV images (p < 0.001). Overall diagnostic confidence was higher in intramedullary nails than plates (p < 0.05).

CONCLUSIONS

Use of virtual monochromatic 130 and 150 keV dual-energy CT compared to 70 keV images improves the evaluation of suspected non-union of the appendicular skeleton treated with titanium or stainless steel intramedullary nails and plates.

Role of Prx1-expressing skeletal cells and Prx1-expression in fracture repair

The healing capacity of bones after fracture implies the existence of adult regenerative cells. However, information on identification and functional role of fracture-induced progenitors is still lacking. Paired-related homeobox 1 (Prx1) is expressed during skeletogenesis. We hypothesize that fracture recapitulates Prx1's expression, and Prx1 expressing cells are critical to induce repair. To address our hypothesis, we used a combination of in vivo and in vitro approaches, short and long-term cell tracking analyses of progenies and actively expressing cells, cell ablation studies, and rodent animal models for normal and defective fracture healing. We found that fracture elicits a periosteal and endosteal response of perivascular Prx1+ cells that participate in fracture healing and showed that Prx1-expressing cells have a functional role in the repair process. While Prx1-derived cells contribute to the callus, Prx1's expression decreases concurrently with differentiation into cartilaginous and bone cells, similarly to when Prx1+ cells are cultured in differentiating conditions. We determined that bone morphogenic protein 2 (BMP2), through C-X-C motif-ligand-12 (CXCL12) signaling, modulates the downregulation of Prx1. We demonstrated that fracture elicits an early increase in BMP2 expression, followed by a decrease in CXCL12 that in turn down-regulates Prx1, allowing cells to commit to osteochondrogenesis. In vivo and in vitro treatment with CXCR4 antagonist AMD3100 restored Prx1 expression by modulating the BMP2-CXCL12 axis. Our studies represent a shift in the current research that has primarily focused on the identification of markers for postnatal skeletal progenitors, and instead we characterized the function of a specific population (Prx1+ cells) and their expression marker (Prx1) as a crossroad in fracture repair. The identification of fracture-induced perivascular Prx1+ cells and regulation of Prx1's expression by BMP2 and in turn by CXCL12 in the orchestration of fracture repair, highlights a pathway in which to investigate defective mechanisms and therapeutic targets for fracture non-union.

Reliability of RUST and Modified RUST Scores for the Evaluation of Union in Humeral Shaft Fractures Treated with Different Techniques

BACKGROUND

The study aimed to evaluate the agreement between the radiographic union scale (RUST) and modified RUST (mRUST) in humeral shaft fractures treated with different techniques, and the effect of surgeons' experience and thresholds for determining bone union.

MATERIALS AND METHODS

A total of 20 orthopedic surgeons reviewed and scored radiographs of 30 patients with humeral shaft fractures treated by external fixation, intramedullary nailing, and plating using the RUST and mRUST on the 0 day, 6 weeks, 12 weeks and 24 weeks follow-up radiographs. Bone healing, interrater agreement between RUST and mRUST scores, and the threshold for radiographic union were evaluated.

RESULTS

The intraclass correlation coefficient (ICC) was slightly higher for the mRUST score than the RUST score (0.71 versus [vs.] 0.67). There was substantial agreement between the mRUST and RUST scores for external fixation (0.75 and 0.69, respectively) and intramedullary nailing (0.79 and 0.71); there was moderate agreement between them for plating (0.59 and 0.55). Surgeons with varying experience had a similar agreement for both scores and scores for each humeral cortex. The external fixation and intramedullary nailing group had higher RUST and mRUST scores than the plating group. The ICC for union was substantial (0.64; external fixation: 0.68, intramedullary nailing: 0.64, and plating: 0.61). More than 90% of the reviewers recorded scores of 10/12 for RUST and 13/16 for mRUST at the time of union.

CONCLUSIONS

RUST and mRUST scores can be used reliably for the evaluation of bony union in humeral fractures treated with an external fixator and intramedullary nailing. In cases of humeral plating, a more sensitive tool for evaluation of fracture union is needed.

The Life of a Fracture: Biologic Progression, Healing Gone Awry, and Evaluation of Union

New knowledge about the molecular biology of fracture-healing provides opportunities for intervention and reduction of risk for specific phases that are affected by disease and medications. Modifiable and nonmodifiable risk factors can prolong healing, and the informed clinician should optimize each patient to provide the best chance for union. Techniques to monitor progression of fracture-healing have not changed substantially over time; new objective modalities are needed.

Tibial Fracture Healing Score: A Novel Tool to Predict Tibial Nonunion

The aim of the study was to investigate the utility of a simple office-based tool in predicting the need for secondary intervention to obtain union in patients with tibial fractures. All patients 18 years and older with isolated tibial shaft fractures (OTA 41A, 42A-C, and 43A) treated with intramedullary nailing from 2013 to 2017 were screened. Eighty-seven patients met enrollment criteria. Surgeon assessment of the following 3 clinical parameters was performed at routine office visits and scored as follows: (1) pain (none/mild/decreased=1, no change/increased=0); (2) function (minimal limp/able to perform a single-leg stance=1, significant limp/unable to perform single-leg stance=0); and (3) examination (no/minimal pain with manipulation=1, pain with manipulation=0). Radiographic healing was assessed by the adjusted radiographic union scale in tibial fractures (aRUST). The tibial fracture healing score (TFHS) is the sum of 3 clinical scores (0 to 3) and aRUST score (1 to 3) at 3 months postoperatively. The overall nonunion rate was 11%. A RUST score of 5 or less and a sum of the 3 clinical scores of less than 2 at 3 months were found be predictive of nonunion. A TFHS of less than 3 at 3 months was more reliable in identifying patients requiring nonunion repair, especially for those with minimal radiographic healing (RUST score 6 or 7) at 3 months. The TFHS is a simple office-based clinical tool that may identify patients at high risk of nonunion (TFHS <3) following isolated tibial shaft fracture more effectively than clinical examination or radiographic assessment alone. [Orthopedics. 2020;43(4);e323-e328.].

Bioinformatic analysis and experimental identification of blood biomarkers for chronic nonunion

Background

Incomplete fracture healing may lead to chronic nonunion; thus, determining fracture healing is the primary issue in the clinical treatment. However, there are no validated early diagnostic biomarkers for assessing chronic nonunion. In this study, bioinformatics analysis combined with an experimental verification strategy was used to identify blood biomarkers for chronic nonunion.

Methods

First, differentially expressed genes in chronic nonunion were identified by microarray data analysis. Second, Dipsaci Radix (DR), a traditional Chinese medicine for fracture treatment, was used to screen the drug target genes. Third, the drug-disease network was determined, and biomarker genes were obtained. Finally, the potential blood biomarkers were verified by ELISA and qPCR methods.

Results

Fifty-five patients with open long bone fractures (39 healed and 16 nonunion) were enrolled in this study, and urgent surgical debridement and the severity of soft tissue injury had a significant effect on the prognosis of fracture. After the systems pharmacology analysis, six genes, including QPCT, CA1, LDHB, MMP9, UGCG, and HCAR2, were chosen for experimental validation. We found that all six genes in peripheral blood mononuclear cells (PBMCs) and serum were differentially expressed after injury, and five genes (QPCT, CA1, MMP9, UGCG, and HCAR2) were significantly lower in nonunion patients. Further, CA1, MMP9, and QPCT were markedly increased after DR treatment.

Conclusion

CA1, MMP9, and QPCT are biomarkers of nonunion patients and DR treatment targets. However, HCAR2 and UGCG are biomarkers of nonunion patients but not DR treatment targets. Therefore, our findings may provide valuable information for nonunion diagnosis and DR treatment.

Trial registration

ISRCTN, ISRCTN13271153. Registered 05 April 2020—Retrospectively registered.

Epidemiology, Clinical Assessments, and Current Treatments of Nonunions

PURPOSE OF REVIEW

The failure of bony union following a fracture, termed a fracture nonunion, has severe patient morbidity and economic consequences. This review describes current consensuses and future directions of investigation for determining why, detecting when, and effective treatment if this complication occurs.

RECENT FINDINGS

Current nonunion investigation is emphasizing an expanded understanding of the biology of healing. This has led to assessments of the immune environment, multiple cytokines and morphogenetic factors, and the role of skeletogenic stem cells in the development of nonunion. Detecting biological markers and other objective diagnostic criteria is also a current objective of nonunion research. Treatment approaches in the near future will likely be dominated by the development of specific adjunct therapies to the nonunion surgical management, which will be informed by an expanded mechanistic understanding of nonunion biology. Current consensus among orthopedists is that improved diagnosis and treatment of nonunion hinges first on discoveries at the bench side with later translation to the clinic.

Nonunion in Patients with Tibial Shaft Fractures: Is Early Physical Status Associated with Fracture Healing?

Background

Nonunions of tibial shaft fractures have devastating physical and psychological consequences for patients. It remains unknown if early functional status can identify patients at risk for nonunion.

Questions/Purposes

To determine if functional status at three months after surgery, as measured by either the short form 36 (SF-36) or the short form 12 (SF-12) health survey physical component summary (SF-12 PCS) score, can serve as a prognostic indicator for nonunion at one year in patients with fractures of the tibial shaft.

Patients/Methods

This study was an observational cohort study nested within two multicenter, randomized controlled trials. Patients who met the following eligibility criteria were included: (1) sustained a tibial shaft fracture that was treated with intramedullary nailing, (2) were unhealed at the three-month follow-up, (3) had a reported SF-36 or SF-12 PCS score at three months, (4) had the final 12-month follow-up with a reported radiographic healing status (bone union or nonunion), and (5) were enrolled in either the Study to Prospectively Evaluate Reamed Intramedullary Nails in Patients with Tibial Shaft Fractures (SPRINT) or Fluid Lavage of Open Wounds (FLOW) randomized trials. Multivariable logistic regression was performed to evaluate the association between healing status at 12 months and seven prognostic variables (open fracture, fracture pattern, nailing technique, smoking, fracture gap, three-month PCS score, and FLOW vs. SPRINT trial).

Results

A total of 940 patients were included in this study with an overall rate of radiographic nonunion of 13.3% (n=125) at the 12-month follow-up. Absolute nonunion risk increased with incrementally lower PCS scores (8.2%, 12.8%, 15.9%, 23.7% for scores ≥ 40, 30.0-39.99, 20.0-29.99, and < 20, respectively). In the multivariable regression analysis, PCS scores of < 20 were associated with a 2.6-times greater odds and 10% absolute risk increase of non-union, as compared to scores of ≥ 40 (OR 2.58, 95%CI: 1.02-6.53, ARI: 10.3, 95% CI: 0.1 - 28.2), whereas scores between 20 and 30 were associated with a nearly two-times greater odds of nonunion and a 6.4% absolute risk increase of nonunion (OR 1.94, 95%CI: 1.08-3.49, ARI: 6.4, 95% CI 0.6 - 15.3). Open fractures also conferred a 2.8-fold increase in odds of nonunion as compared to closed injuries (OR 2.77, 95%CI: 1.58-4.83), as did complex fractures when compared to simple fractures (OR 2.57, 95%CI: 1.64-4.02).

Conclusion

A considerable portion of patients with fractures of the tibial shaft treated with intramedullary nailing will experience nonunion at one-year postoperatively. Nonunion can be accurately predicted by patient functional recovery at three months as measured by the PCS of the SF-36 and SF-12 instruments.

Effect of changes in serum levels of endogenous hydrogen sulfide on fracture healing: Study protocol clinical trial (SPIRIT compliant)

BACKGROUND

Fracture is a common disease; many factors affect fracture healing. Recent studies have confirmed that hydrogen sulfide (H2S) plays an essential role in bone formation, but most of these studies are drawing conclusions based on animal experiment; whether H2S could promote fracture healing in patients is still unclear. We aim to investigate the change of serum H2S in fracture patients, and analyze its effort on fracture healing.

METHODS

This is a single-center, prospective cohort study. Patients with spinal or limb fracture will be recruited. Patient's serum and urine will be collected at baseline for examination (serum H2S, β-CTX, OC, PINP, 25-OH-VitD3, S-CTX, urinary calcium, and urinary creatinine). All patients will be followed-up for 24 months in outpatients settings, the image of X-ray or CT will be reviewed and fracture healing will be judged by 2 experienced orthopedic physicians. The difference in serum parameters especially H2S will be compared between patients with fracture healed within 9 months and those with fracture unhealed at 9 months.

DISCUSSION

Results of the trial could provide insight into influence of H2S on fracture healing.

ETHICS AND DISSEMINATION

The study was approved by the ethics committee of School of Medicine UESTC & Sichuan Provincial People's Hospital Ethics Committee. All the participants will be asked to provide written informed consent before data collection. The findings of the study will be published in peer-reviewed journals and will be presented at national or international conferences.

Validation of a long bone fracture non-union healing score after treatment with mesenchymal stromal cells combined to biomaterials

The available scores to clinically evaluate fracture consolidation encounter difficulties to interpret progression towards consolidation in long-bone non-union, particularly when incorporating biomaterials in the surgical treatment. The aims of this study were to validate the REBORNE bone healing scale in tibia, humerus and femur non-unions treated by a combination of mesenchymal stromal cells (MSCs) and biomaterials, through the interclass correlation (ICC) among raters, and to define reliability and concordance in anteroposterior and lateral radiographs, compared to computed tomography (CT).

METHODS

Twenty-six cases from the EudraCT 2011-005441-13 clinical trial underwent bone healing evaluation, if at least 3 out of 4 cortical views clearly identified. Three senior orthopaedic surgeons evaluated radiographs and CTs at 3 and 6 months FU. All cases included preoperative imaging and radiographs at 12 months. The 4-stage scale score was obtained from each cortical view in orthogonal radiographs or CTs. A score of 0.6875 (11/16) was set as a threshold for bone healing. Statistically, ICC evaluated agreement among raters. Cronbach's alpha coefficient tested reliability. Lin's concordance correlation coefficients (CCC) were estimated between mean CT scores and mean radiographic scores. Bland and Altman graphs provided the limits of agreement between both imaging techniques. Sensitivity and specificity were assessed in radiographs (against CT), and the Area Under the Receiver Operating Characteristics (ROC) Curve was estimated. The probability to predict bone consolidation with REBORNE scores obtained from radiographs was modelled.

RESULTS

An ICC of 0.88 and 0.91 (CT and radiographs) confirmed agreement in the REBORNE score for non-union bone healing, with an inter-rater reliability of 0.92 and 0.95. Scores through the radiographic evaluation were found equivalent to the CTs at 6 months FU. A CCC of 0.79 was detected against CT. The radiographic scores in the REBORNE bone healing scale correctly classified bone consolidation in 77%, with an accuracy of 83% based on ROC curves.

CONCLUSIONS

The REBORNE score measured with CT or radiographic images was reliable among raters at a follow-up time above 6 months for long bone non-union fractures. The REBORNE scale measured with radiographs proved valid to assess consolidation against CT measurements.

Biomechanics of callus in the bone healing process, determined by specimen-specific finite element analysis

As fractures heal, immature callus formed in the hematoma is calcified by osteoblasts and altered to mature bone. Although the bone strength in the fracture-healing process cannot be objectively measured in clinical settings, bone strength can be predicted by specimen-specific finite element modeling (FEM) of quantitative computed tomography (qCT) scans. FEM predictions of callus strength would enable an objective treatment plan. The present study establishes an equation that converts material properties to bone density and proposes a specimen-specific FEM. In 10 male New Zealand white rabbits, a 10-mm long bone defect was created in the center of the femur and fixed by an external fixator. The callus formed in the defect was extracted after 3-6 weeks, and formed into a (5 × 5 × 5 mm³) cube. The bone density measured by qCT was related to the Young's modulus and the yield stress measured with a mechanical tester. For validation, a 10-mm long bone defect was created in the central femurs of another six New Zealand white rabbits, and fixed by an external fixator. At 3, 4, and 5 weeks, the femur was removed and subjected to Computed tomography (CT) scanning and mechanical testing. A specimen-specific finite element model was created from the CT data. Finally, the bone strength was measured and compared with the experimental value. The bone mineral density σ was significantly and nonlinearly correlated with both the Young's modulus E and the yield stress σ. The material-property conversion equations were E = 0.2391e^8.00ρ and ρ = 30.49σ^2.41. Moreover, the experimental bone strength was significantly linearly correlated with the prospective FEM. We demonstrated the Young's moduli and yield stresses for different bone densities, enabling a FEM of the bone-healing process. An FEM based on these material properties is expected to yield objective clinical judgment criteria.