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

Postoperative outcome of screw fixation with autogenous bone grafting for the management of hallux sesamoid fracture nonunion

INTRODUCTION

Although sesamoid-preserving procedures have been attempted to complement sesamoidectomy for hallux sesamoid fracture nonunion, few reports document the results. Accordingly, the objective of this study was to review the outcomes of patients with hallux sesamoid fracture nonunion who underwent screw fixation with autogenous bone grafting.

MATERIALS AND METHODS

Medical records of patients who underwent surgery between January 2013 and September 2022 were reviewed. Outcomes were assessed using the foot function index (FFI) and the visual analog scale (VAS) for pain. Fracture union was assessed using plain radiographs and computed tomography scans.

RESULTS

Ten patients (4 males and 6 females) were enrolled. The mean age was 39.4 years (standard deviation [SD], 14.0), and the mean follow-up duration was 23.4 months (SD, 14.5). The FFI score improved from 72.3 (SD, 8.7) preoperatively to 8.2 (SD, 10.7) 12 months postoperatively and to 6.6 (SD, 8.3) at the final follow-up (p < 0.01, respectively). The VAS score improved from 67.8 (SD, 13.5) preoperatively to 2.2 (SD, 3.8) 12 months postoperatively, finally improving to 3.6 (SD, 4.8) at the final follow-up (p < 0.01, respectively). Union was achieved in all patients 3 months postoperatively. Although no complications were observed, hardware removal was performed in two patients owing to discomfort and psychological anxiety.

CONCLUSION

Given that the symptoms improved in all patients without complications, as observed in this study, screw fixation with autogenous bone grafting appears to be a viable option for treating hallux sesamoid fracture nonunion.

Utility of ultrasound imaging in monitoring fracture healing in rat femur: Comparison with other imaging modalities

Objective

Fractures are common injuries and various imaging modalities are employed to diagnose and monitor bone union. However, the follow-up of fracture healing using ultrasound imaging (US) remains a topic of debate. In this study, we analyzed of fracture healing process and compared US and radiological analyses with histological analyses to clarify the characteristics and limitations of each modality.

Methods

An osteotomy model was created using the femur of Wistar rats, and US, radiological (radiography and micro-computed tomography (micro-CT)), and histological analyses were performed. Radiological assessments were conducted for the evaluation of calcified tissue. The gap between the bony callus and cartilaginous callus was measured.

Results

US effectively captured changes on the fracture surface, potentially reflecting the early healing processes. Both US and radiographic findings showed strong correlation in terms of the decrease in the bony callus gap. US was unable to distinguish cartilaginous callus from the surrounding soft tissue. During the remodeling stage, micro-CT offered a detailed assessment of the internal fracture surface, whereas US was limited to evaluating the outer bone surface and lacked accuracy in visualizing the entire fracture site. Radiography provided a general overview of the fractures. The decrease in the bony callus gap measured using US correlated with the reduction in cartilaginous callus observed histologically.

Conclusion

This study demonstrated that US could be a valuable tool for evaluating fracture healing. Combining fracture management with US and radiological examinations may provide a more accurate assessment of healing progress.

Autopsy doesn't always tell all: The importance of exhuming skeletal remains of cemetery unidentified decedents

The process of personal identification differs according to the state of preservation of the corpse, becoming more complicated when dealing with remains altered by taphonomic variables. Since 2015, the staff of the Laboratory of Forensic Anthropology and Odontology (LABANOF) of the University of Milan has been engaged in recovering the skeletons of 36 unknown people from the cemeteries of the city of Milan, to redraw their biological profiles and give them back the possibility of being identified. Of the 36 starting skeletons, 7 have been identified and therefore are not the object of this study, 25 individuals were previously subjected to an autopsy examination and 4 skeletons were studied for the first time in the present work. The post-mortem data of all the individuals who had previously undergone autopsy and had not yet been identified (n = 25) have been retrieved from the archives of the Institute of Forensic Medicine in Milan and allowed for a comparison with those obtained from the new anthropological study of each exhumed skeleton. The authors aim to present the three most interesting cases to better highlight the results that emerged from the comparison. The autopsy information alone lacked important details. In all cases, the anthropological examination proved to be capable of detailing the biological profile of the unknowns even after a long period of inhumation (even more than 20 years). The limitations of instrumental investigations in achieving the goal single-handedly and the importance of recovering the unknown skeletons from cemeteries for identification purposes are discussed.

Role of Whey Protein in the Treatment Outcome of Maxillofacial Trauma Patients: An Interventional Study

Introduction

Maxillofacial fracture severely affects the diet of the patients leading to reduction of body weight. Facial trauma affects the muscles of mastication and the bones of face leading to reduction in bite force. The purpose of our study was to investigate the effect of whey protein supplement in the postoperative period of maxillofacial trauma patients with respect to body weight, bite force and callus formation.

Methodology

Patients were divided into control group and study group having 20 patients each. The control group received usual modified diet for maxillofacial fracture and study group received same diet along with whey protein for 6 weeks.

Results

There was mean weight loss of 3.15 kg in control group whereas there was no weight loss of in the study group. There was statistically significant increase in bite force in the study group compared to the control group with p value < 0.05. Early callus formation was seen in study group compared to control group.

Conclusion

Our results showed that patients who were supplemented with whey protein had no loss of body weight, better masticatory efficiency, better healing of the fracture sites and overall early recovery.

The Impact of Blood Flow Restriction Training on Tibial Bone Stress Injury Rehabilitation: An Exploratory Case Series

Background

Lower extremity bone stress injuries (BSI) are common injuries among athletes and military members. Typical management involves a period of restricted weightbearing which can have rapid detrimental effects upon both muscle and bone physiology. Few studies have investigated the effect of blood flow restriction (BFR) training on bone in the rehabilitative setting.

Purpose

The purpose of this study was to investigate the effects of lower extremity exercise with the addition of BFR upon bone mineral density, bone mineral content, and lean body mass in military members with tibial BSIs.

Study Design

Case series.

Methods

Twenty military members with MRI-confirmed tibial BSI were recruited to complete lower extremity exercise with the addition of BFR twice per week for four weeks. The BFR cuff was applied proximally to the participant's involved limb while they performed gluteal, thigh, and leg resistance exercises. Outcomes were assessed at baseline and four weeks. The primary outcomes were whole leg bone mineral density (BMD), bone mineral content (BMC), and lean body mass (LM) as measured by dual-energy x-ray absorptiometry. Secondary outcomes included thigh and leg circumference measures and patient-reported outcomes, including the Lower Extremity Functional Scale (LEFS), Patient-Reported Outcomes Measurement Information System 57 (PROMIS-57), and Global Rating of Change (GROC).

Results

No significant differences were found in BMD (p=0.720) or BMC (p=0.749) between limbs or within limbs over time. LM was generally less in the involved limb (p=0.019), however there were no significant differences between or within limbs over time (p=0.404). For thigh circumference, significant main effects were found for time (p=0.012) and limb (p=0.015), however there was no significant interaction effect (p=0.510). No significant differences were found for leg circumference (p=0.738). Participants showed significant mean changes in LEFS (15.15 points), PROMIS physical function (8.98 points), PROMIS social participation (7.60 points), PROMIS anxiety (3.26 points), and PROMIS pain interference (8.39 points) at four weeks.

Conclusion

The utilization of BFR in the early rehabilitative management of tibial BSI may help mitigate decrements in both bone and muscle tissue during periods of decreased physical loading.

Level of Evidence

4.

Clinical management and innovation in fracture non-union

INTRODUCTION

With the introduction and continuous improvement in operative fracture fixation, even the most severe bone fractures can be treated with a high rate of successful healing. However, healing complications can occur and when healing fails over prolonged time, the outcome is termed a fracture non-union. Non-union is generally believed to develop due to inadequate fixation, underlying host-related factors, or infection. Despite the advancements in fracture fixation and infection management, there is still a clear need for earlier diagnosis, improved prediction of healing outcomes and innovation in the treatment of non-union.

AREAS COVERED

This review provides a detailed description of non-union from a clinical perspective, including the state of the art in diagnosis, treatment, and currently available biomaterials and orthobiologics.Subsequently, recent translational development from the biological, mechanical, and infection research fields are presented, including the latest in smart implants, osteoinductive materials, and in silico modeling.

EXPERT OPINION

The first challenge for future innovations is to refine and to identify new clinical factors for the proper definition, diagnosis, and treatment of non-union. However, integration of in vitro, in vivo, and in silico research will enable a comprehensive understanding of non-union causes and correlations, leading to the development of more effective treatments.

Clinical and radiological outcomes of ankle joint preserving surgical reconstruction for talar neck non-unions-A series of 8 cases

BACKGROUND

Talar neck non-unions result in significant hindfoot deformity and morbidity and are infrequently reported in the literature. The optimal surgical management for this condition is evolving, with various authors reporting the results of open reduction and internal fixation (ORIF) with bone grafting (BG), ankle fusion and modified Blair fusion. We performed this study to report the clinical and radiological outcomes of a cohort of talar neck non-unions managed by ankle joint preserving reconstruction.

METHODS

This was an ambispective study which included 8 patients (7 male and 1 female) with talar neck non-unions. All patients underwent ORIF+BG through dual approaches. Additional medial malleolar osteotomy was done in 2 cases, and calcaneofibular split approach to the subtalar joint in 3. Adjunct subtalar fusion was done in 5 cases. Clinical and radiological evaluation was performed pre- and post-operatively. Functional outcomes were assessed by the Manchester Oxford Foot Questionnaire (MOxFQ).

RESULTS

The mean age of patients 32.3 ± 13.1 years. The mean surgical delay was 4.1 ± 1.7 months. As per Zwipp and Rammelt classification of post-traumatic talar deformities, 5 cases were classified as Type 3, 2 were Type 4, and 1 was Type 1. Union was achieved in 7 cases at a mean of 3.4 ± 1.3 months. One case had progressive collapse, which was managed by pantalar arthrodesis. All 3 cases where subtalar fusion was not performed primarily demonstrated subtalar arthrosis, but none required a secondary subtalar fusion. The MOxFQ score from 61.1 ± 10.1 to 41 ± 14.1 postoperatively (P = 0.005). The mean follow-up was 14.6 ± 6.8 months.

CONCLUSION

ORIF+BG of the talar neck, with or without subtalar fusion has the potential to achieve solid union, correct the hindfoot deformity and improve functional outcomes. However, larger studies with longer follow-up are needed to evaluate the long-term efficacy of this procedure.

Approach to Tibial Shaft Nonunions: Diagnosis and Management

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

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.

Metacarpal and Phalangeal Nonunions

The majority of phalangeal and metacarpal fractures will proceed to union when appropriately treated. However, when a nonunion does occur, it can lead to significant functional impairment for patients and societal costs. Operative intervention is typically required in these cases, but the technique can vary depending on each individual patient scenario. This article provides an overview of nonunions of the metacarpals and phalanges in the hand, including incidence, risk factors, current treatment options, and postoperative care.

Principles and Evaluation of Bony Unions

Nonunion is a common and costly problem. Unfortunately, there is no widely agreed upon and standardized definition for nonunion. The evaluation of bony union should start with a thorough history and physical examination. The clinician should consider patient-dependent as well as patient-independent characteristics that may influence the rate of healing and evaluate the patient for physical examination findings suggestive of bony union and infection. Radiographs and clinical examination can help confirm a diagnosis of union. When the diagnosis is in doubt, however, advanced imaging modalities as well as laboratory studies can help a surgeon determine when further intervention is necessary.

Time to surgery and outcomes following open reduction and internal fixation of both-bone forearm fractures

PURPOSE

To determine the effect of time to surgery on outcomes following open reduction and internal fixation (ORIF) of both-bone forearm fractures (BBFFs).

METHODS

Ninety-nine patients who underwent ORIF of BBFFs in a single academic medical center over a 16-year time period were retrospectively reviewed. Demographic and clinical data including age, sex, current smoking status, time from injury to surgery (tsurg), presence of open injury, polytrauma status, and complications were obtained. Radiographs of the affected extremity were reviewed for fracture morphology, reduction quality, and time to union (or presence of nonunion). In addition to descriptive statistics, Chi-square and Wilcoxon-Mann-Whitney tests were used to compare categorical and interval, respectively, with a significance level of 0.05.

RESULTS

A tsurg > 48 h was associated with increased rate of delayed unions (tsurg < 48 h: 25% vs tsurg > 48 h: 59%, p = 0.03), but not complications (tsurg < 48 h: 44% vs tsurg > 48 h: 47%, p = 0.79). Open BBFFs were not associated with increased rates of delayed unions (closed: 16% vs open: 19%, p = 0.77) or complications (closed: 42% vs open: 53%, p = 0.29). A trend toward increased time to union with tsurg > 48 h was also seen, but did not reach significance (tsurg < 48 h: 13.5 weeks vs tsurg > 48 h: 15.7 weeks, p = 0.11).

CONCLUSION

A tsurg > 48 h is associated with an increased rate of delayed union, but not complications, after ORIF of BBFFs.

LEVEL OF EVIDENCE

Therapeutic Level III (Retrospective Cohort).

Application of stacked autoencoder for identification of bone fracture

This study presents a stacked autoencoder (SAE)-based assessment method which is one of the unsupervised learning schemes for the investigation of bone fracture. Relatively accurate health monitoring of bone fracture requires considering physical interactions among tissue, muscle, wave propagation and boundary conditions inside the human body. Furthermore, the investigation of fracture, crack and healing process without state-of-the-art medical devices such as CT, X-ray and MRI systems is challenging. To address these issues, this study presents the SAE method that incorporates bilateral symmetry of the human legs and low-frequency transverse vibration. To verify the presented method, several examples are employed with plastic pipes, cadaver legs and human legs. Virtual spectrograms, created by applying a short-time Fourier transform to the differences in vibration responses, are employed for image-based training in SAE. The virtual spectrograms are then classified and the fine-tuning is also carried out to increase the accuracy. Moreover, a confusion matrix is employed to evaluate classification accuracy and training validity.

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

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

Outcomes After Superior Capsular Reconstruction With an Achilles Tendon-Bone Allograft Using the Modified Keyhole Technique: A 2-Year Follow-up of a Novel Technique for Irreparable Rotator Cuff Tears

Background

Despite improved outcomes, failure or nonhealing of graft materials has been reported after superior capsular reconstruction (SCR) for massive irreparable rotator cuff tears.

Purpose

To evaluate the short-term clinical and radiological outcomes of a novel technique for SCR using an Achilles tendon-bone allograft.

Study Design

Case series; Level of evidence, 4.

Methods

We performed a retrospective review of patients who underwent SCR using an Achilles tendon-bone allograft with the modified keyhole technique and who had a minimum follow-up of 2 years. The visual analog scale score for pain, American Shoulder and Elbow Surgeons score, and Constant score were evaluated as subjective outcomes, while range of motion of the shoulder joint and isokinetic strength were evaluated as objective outcomes. The acromiohumeral interval (AHI), bone-to-bone healing of the allograft and humeral head on computed tomography, and graft integrity on magnetic resonance imaging were evaluated as radiological outcomes.

Results

This study included 32 patients with a mean age of 56.8 ± 4.2 years and a mean follow-up of 28.4 ± 6.2 months. A significant improvement from preoperatively to the last follow-up was seen in the mean visual analog scale score for pain (from 6.7 to 1.8), American Shoulder and Elbow Surgeons score (from 42.7 to 83.8), Constant score (from 47.2 to 78.5), and AHI (from 4.8 to 8.2 mm) (P < .001 for all) as well as range of motion in forward elevation and internal rotation (P < .001 for both). Medial-to-lateral graft integrity was good in all patients. Nonunion at the fitting zone of the keyhole on the greater tuberosity was diagnosed in 1 case (3.1%), and failure of incorporation between the allograft and remnant tendon at the site of posterior margin convergence was observed in 4 cases (12.5%).

Conclusion

The outcomes after SCR using an Achilles tendon-bone allograft and the keyhole technique improved, with an increased AHI and excellent integrity in the medial and lateral directions compared with preoperatively. This technique is a reasonable option for the surgical treatment of irreparable rotator cuff tears.

Computer-Based Mechanobiological Fracture Healing Model Predicts Non-Union of Surgically Treated Diaphyseal Femur Fractures

As non-unions are still common, a predictive assessment of healing complications could enable immediate intervention before negative impacts for the patient occur. The aim of this pilot study was to predict consolidation with the help of a numerical simulation model. A total of 32 simulations of patients with closed diaphyseal femoral shaft fractures treated by intramedullary nailing (PFNA long, FRN, LFN, and DePuy Synthes) were performed by creating 3D volume models based on biplanar postoperative radiographs. An established fracture healing model, which describes the changes in tissue distribution at the fracture site, was used to predict the individual healing process based on the surgical treatment performed and full weight bearing. The assumed consolidation as well as the bridging dates were retrospectively correlated with the clinical and radiological healing processes. The simulation correctly predicted 23 uncomplicated healing fractures. Three patients showed healing potential according to the simulation, but clinically turned out to be non-unions. Four out of six non-unions were correctly detected as non-unions by the simulation, and two simulations were wrongfully diagnosed as non-unions. Further adjustments of the simulation algorithm for human fracture healing and a larger cohort are necessary. However, these first results show a promising approach towards an individualized prognosis of fracture healing based on biomechanical factors.

Ultrasensitive capacitive sensing system for smart medical devices with ability to monitor fracture healing stages

Bone fractures are a global public health problem. A sustained increase in the number of incident cases has been observed in the last few decades, as well as the number of prevalent cases and the number of years lived with disability. Current monitoring techniques are based on imaging techniques, which are highly subjective, radioactive, expensive and unable to provide daily monitoring of fracture healing stages. The development of reliable, non-invasive and non-subjective technologies is mandatory to minimize non-union risks. Delayed healing and non-union conditions require timely medical intervention, such that preventive procedures and shortened treatment periods can be carried out. This work proposes the development of an ultrasensitive capacitive sensing system for smart implantable fixation implants with ability to effectively monitor the evolution of bone fractures. Both in vitro experimental tests and numerical simulations highlight that networks of co-surface capacitive systems are able: (i) to detect four different bone healing phases, capacitance decrease patterns occurring as the healing process progresses and (ii) to monitor the callus evolution in multiple target regions. These are very promising results that highlight the potential of capacitive technologies to minimize the individual and social burdens related to fracture management, mainly when delayed healing or non-union conditions occur.

The decisive early phase of bone regeneration

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