Current Options for Determining Fracture Union

Design of osteosynthesis plate for detecting bone union using wire natural frequency

We have developed a novel osteosynthesis plate with bone union detection using a wire's natural frequency (BUDWF) to provide the quantitative result of bone union detection. The concept for detecting bone union is measuring the rate of frequency change. The frequency is measured from sound generated from the wire attached to a modified plate. The plate is modified from a Syncera ADLER B0409.10 and attached with 0.3 mm diameter 316L stainless steel wire. The sound generation mechanism was created by PEEK and installed on the plate to generate the sound. The preliminary experiments were conducted on a Sawbones tibia composite mimic. We used the cut Sawbones to create fracture samples with a 0, 0.5, 1-, 2-, and 5-mm gap representing the fractured bone with different gap sizes and prepared uncut Sawbones as a union sample. These samples were tested five times, and the sound was recorded from a condenser microphone and analyzed. We found that the BUDWF can differentiate samples with a fracture gap above 2 mm from the union sample, as the differences in the rates of frequency change between samples with a fracture gap above 2 mm and union samples were statistically significant. However, there was a limitation that the BUDWF plate was still unable to differentiate the 0 mm fracture gap and the union sample in this study.

Murine Progeria Model Exhibits Delayed Fracture Healing with Dysregulated Local Immune Response

Background

Bone fracture is one of the most globally prevalent injuries, with an estimated 189 million bone fractures occurring annually. Delayed union or nonunion occurs in up to 15% of fractures and involves the interruption or complete failure of bone continuity following fracture. Preclinical testing is essential to support the translation of novel strategies to promote improved fracture repair treatment, but there is a paucity of small animal models that recapitulate clinical attributes associated with delayed fracture healing. This study explores whether the Zmpste24 -/- (Z24 -/- ) knockout mouse model of Hutchinson-Gilford progeria syndrome presents with delayed fracture healing. Leveraging the previously characterized Z24 -/- phenotype of genomic instability, epigenetic changes, and fragility, we hypothesize that these underlying alterations will lead to significantly delayed fracture healing relative to age-matched wild type (WT) controls.

Methods

WT and Z24 -/- mice received intramedullary fixed tibia fractures at ∼12 weeks of age. Mice were sacrificed throughout the time course of repair for the collection of organs that would provide information regarding the local (fracture callus, bone marrow, inguinal lymph nodes) versus peripheral (peripheral blood, contralateral tibia, abdominal organs) tissue microenvironments. Analyses of these specimens include histomorphometry, μCT, mechanical strength testing, protein quantification, gene expression analysis, flow cytometry for cellular senescence, and immunophenotyping.

Results

Z24 -/- mice demonstrated a significantly delayed rate of healing compared to WT mice with consistently smaller fracture calli containing higher proportion of cartilage and less bone after injury. Cellular senescence and pro-inflammatory cytokines were elevated in the Z24 -/- mice before and after fracture. These mice further presented with a dysregulated immune system, exhibiting generally decreased lymphopoiesis and increased myelopoiesis locally in the bone marrow, with more naïve and less memory T cell but greater myeloid activation systemically in the peripheral blood. Surprisingly, the ipsilateral lymph nodes had increased T cell activation and other pro-inflammatory NK and myeloid cells, suggesting that elevated myeloid abundance and activation contributes to an injury-specific hyperactivation of T cells.

Conclusion

Taken together, these data establish the Z24 -/- progeria mouse as a model of delayed fracture healing that exhibits decreased bone in the fracture callus, with weaker overall bone quality, immune dysregulation, and increased cellular senescence. Based on this mechanism for delayed healing, we propose this Z24 -/- progeria mouse model could be useful in testing novel therapeutics that could address delayed healing.

The Translational Potential of this Article

This study employs a novel animal model for delayed fracture healing that researchers can use to screen fracture healing therapeutics to address the globally prevalent issue of aberrant fracture healing.

Retrograde intramedullary nailing with supplemental plate and lag screws allows early weight bearing following distal end-segment femur fractures (AO/OTA 33) in a low-resource setting

PURPOSE

To underline the feasibility of achieving early weight bearing in patients with distal end-segment femur fractures (AO/OTA 33) treated with retrograde intramedullary nailing and supplemental plate or lag screws in the absence of C-arm.

METHODS

41 distal end-segment femur fractures (DFFs) included in the study were treated with SIGN nails with or without a side plate in a center that lacked intraoperative fluoroscopy and fracture table. A medial or lateral para-patellar incision was used for fracture reduction, nail insertion and side plate placement. Follow-ups were done at six weeks, 12 weeks, and six months post-operatively.

RESULTS

Distal end-segment fractures constituted 13.2% of all femur fractures treated. The patients' mean age and range were 49.6 and 23-83 years respectively. They were mostly injured in road traffic accidents. 27 were daily-income earners. By the 12th week post-operatively, 82.1% of them could flex their knee beyond 90°, all of them could bear weight fully, and 71.8% could squat & smile.

CONCLUSION

The study highlighted the procedure for retrograde nailing of DFFs in a setting without the requisite facilities for minimally-invasive surgeries. The findings demonstrated the feasibility of achieving an expedited weight bearing for the predominantly daily-income-earning victims to ensure early return to work and poverty reduction. While the small sample size is a limitation, the study does provide information that could serve as a basis for future randomized controlled trials in low-resource settings.

Assessing the effectiveness of intramedullary nailing for tibial shaft fractures in a low-income setting: a prospective study in Yemen

BACKGROUND

Tibial shaft fractures are common injuries that can be treated with various methods, including interlocked intramedullary nail (IMN). However, there is limited data on the clinical outcomes of IMN for tibial shaft fractures in Yemen.

OBJECTIVE

To evaluate the clinical outcomes of primary IMN for tibial shaft fractures in Yemen.

METHODS

This was a prospective study of 134 patients who underwent primary IMN for tibial shaft fractures et al.-Thawra Modern General Hospital in Sana'a, Yemen, between June 2016 and June 2020. The patients were between 18 and 70 years old, and the fractures were classified according to the AO classification system. The fractures were treated with IMN using a standard technique. The patients were followed up for a minimum of 2 years. The outcome measures included union time, complications, and functional scores.

RESULTS

The mean union time was 17 weeks. The overall complication rate was 18.7%. The most common complications were infection (8.2%), delayed union (6.7%), and nonunion (3.7%). The mean functional scores at the final follow-up were 91.4 for the Knee Society Score and 90.2 for the American Orthopaedic Foot and Ankle Society Score.

CONCLUSION

Primary IMN is an effective and reliable method for treating tibial shaft fractures in Yemen, with acceptable union time, complication rate, and functional outcomes.

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.

Increased Osteoblast GαS Promotes Ossification by Suppressing Cartilage and Enhancing Callus Mineralization During Fracture Repair in Mice

GαS, the stimulatory G protein α-subunit that raises intracellular cAMP levels by activating adenylyl cyclase, plays a vital role in bone development, maintenance, and remodeling. Previously, using transgenic mice overexpressing GαS in osteoblasts (GS-Tg), we demonstrated the influence of osteoblast GαS level on osteogenesis, bone turnover, and skeletal responses to hyperparathyroidism. To further investigate whether alterations in GαS levels affect endochondral bone repair, a postnatal bone regenerative process that recapitulates embryonic bone development, we performed stabilized tibial osteotomy in male GS-Tg mice at 8 weeks of age and examined the progression of fracture healing by micro-CT, histomorphometry, and gene expression analysis over a 4-week period. Bone fractures from GS-Tg mice exhibited diminished cartilage formation at the time of peak soft callus formation at 1 week post-fracture followed by significantly enhanced callus mineralization and new bone formation at 2 weeks post-fracture. The opposing effects on chondrogenesis and osteogenesis were validated by downregulation of chondrogenic markers and upregulation of osteogenic markers. Histomorphometric analysis at times of increased bone formation (2 and 3 weeks post-fracture) revealed excess fibroblast-like cells on newly formed woven bone surfaces and elevated osteocyte density in GS-Tg fractures. Coincident with enhanced callus mineralization and bone formation, GS-Tg mice showed elevated active β-catenin and Wntless proteins in osteoblasts at 2 weeks post-fracture, further substantiated by increased mRNA encoding various canonical Wnts and Wnt target genes, suggesting elevated osteoblastic Wnt secretion and Wnt/β-catenin signaling. The GS-Tg bony callus at 4 weeks post-fracture exhibited greater mineral density and decreased polar moment of inertia, resulting in improved material stiffness. These findings highlight that elevated GαS levels increase Wnt signaling, conferring an increased osteogenic differentiation potential at the expense of chondrogenic differentiation, resulting in improved mechanical integrity. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

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.

Stabilization of Tibial Fractures at Risk of Complications With the Bactiguard Intramedullary Nail: Early to Medium Results With a Novel Metal-Coated Device

OBJECTIVES

The purpose of this study was to investigate the safety and early clinical results from the use of a novel, noble metal-coated titanium tibial nail for the definite stabilization of tibial shaft fractures at risk of developing complications.

DESIGN

This is a retrospective case series with prospectively collected data.

SETTING

Level I Trauma Centre in the United Kingdom.

PATIENTS AND INTERVENTION

Thirty-one patients who were managed with the Bactiguard-coated Natural Nail and achieved a minimum of a 12-month follow-up.

MAIN OUTCOME MEASUREMENTS

The main outcomes of this study were the incidence of adverse events (related to implant safety), complications (particularly infection), and reinterventions.

RESULTS

Thirty-one patients with a mean age of 41.6 years were included in this study. Active heavy smokers or intravenous drug users were 25.8% and 9.7% of them were diabetic. Five fractures were open while 13 had concomitant soft-tissue involvement (Tscherne grade 1 or 2). Twenty-seven patients healed with no further intervention in a mean time of 3.3 months. Three patients developed nonunion and required further intervention. The overall union rate was 96.7%. One patient developed deep infection after union (infection incidence 3.2%). Six patients (6/31; [19.3%]) required reinterventions [2 for the treatment of nonunion, 3 for removal of screws soft-tissue irritation, and 1 for the management of infection).

CONCLUSIONS

The management of tibial shaft fractures with a noble metal-coated titanium tibial nail demonstrates encouraging outcomes. Further studies are desirable to gather more evidence in the performance of this innovative implant.

LEVEL OF EVIDENCE

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

To Bury or Not to Bury the K-wires After Fixation of Both Bone Forearm Fractures in Patients Younger Than 11 Years Old: A Randomized Controlled Trial

PURPOSE

The primary objective was to compare the re-fracture incidence of both radius and ulna fracture in 2 groups treated using intramedullary Kirschner wires (K-wires) where the wires were exposed in group I and buried in group II. The secondary objective was to compare the final functional outcomes and complications incidence.

METHODS

Between March 2019 and February 2021, 60 pediatric patients with unstable radius and ulna fractures amenable to surgical intervention using intramedullary K-wires were randomized into group I (K-wires were exposed above the skin by 2 cm) or group II (K-wires were buried under the skin). In group I, K-wires were removed in the outpatient clinic, while in group II, they were removed under general anesthesia as a day-case procedure. Functional outcome per Price criteria was reported at 1-year follow-up.

RESULTS

Included patients had a mean age of 7.6 years (range: 5 to 10 y). The mean operative time was significantly higher in group II (32.33±7.51 vs. 36.77±8.70 min, P =0.03), with no difference regarding intraoperative x-ray exposure (43.12±15.52 vs. 41.6±11.96 s, P =0.67). Fracture union was achieved after a mean of 44±2.6 days in group I and 43±1.87 days in group II, with no difference between both groups ( P =0.34). One patient had re-fracture in group I and no patients in group II; however, the difference was insignificant ( P =0.12). Infection occurred in 2 patients in each group. All patients reported excellent scores per Price criteria and achieved full wrist and elbow range of motion compared with the contralateral noninjured side.

CONCLUSIONS

Exposed implants are a safe option when dealing with forearm fractures in patients younger than 11 years old, with the added advantage of fewer hospital admissions. Furthermore, it had a similar complication rate and functional outcomes compared with buried implants.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT03906929.

LEVEL OF EVIDENCE

Level II.

The contribution of lower-mineralized tissue to the healing of distal radius fractures assessed using HR-pQCT

High-resolution peripheral quantitative CT (HR-pQCT) enables quantitative assessment of distal radius fracture healing. In previous studies, lower-mineralized tissue formation was observed on HR-pQCT scans, starting early during healing, but the contribution of this tissue to the stiffness of distal radius fractures is unknown. Therefore, the aim of this study was to investigate the contribution of lower-mineralized tissue to the stiffness of fractured distal radii during the first twelve weeks of healing. We did so by combining the results from two series of micro-finite element (μFE-) models obtained using different density thresholds for bone segmentation. Forty-five postmenopausal women with a conservatively-treated distal radius fracture had HR-pQCT scans of their fractured radius at baseline (BL; 1-2 weeks post-fracture), 3-4 weeks, 6-8 weeks, and 12 weeks post-fracture. Compression stiffness (S) was computed using two series of μFE-models from the scans: one series (Msingle) included only higher-mineralized tissue (>320 mg HA/cm3), and one series (Mdual) differentiated between lower-mineralized tissue (200-320 mg HA/cm3) and higher-mineralized tissue. μFE-elements were assigned a Young's Modulus of 10 GPa (higher-mineralized tissue) or 5 GPa (lower-mineralized tissue), and an axial compression test to 1 % strain was simulated. The contribution of the lower-mineralized tissue to S was quantified as the ratio Sdual/Ssingle. Changes during healing were quantified using linear mixed effects models and expressed as estimated marginal means (EMMs) with 95 %-confidence intervals (95 %-CI). Median time to cast removal was 5.0 (IQR: 1.1) weeks. Sdual and Ssingle gradually increased during healing to a significantly higher value than BL at 12 weeks post-fracture (both p < 0.0001). In contrast, Sdual/Ssingle was significantly higher than BL at 3-4 weeks post-fracture (p = 0.0010), remained significantly higher at 6-8 weeks post-fracture (p < 0.0001), and then decreased to BL-values at the 12-week visit. EMMs ranged between 1.05 (95 %-CI: 1.04-1.06) and 1.08 (95 %-CI: 1.07-1.10). To conclude, combining stiffness results from two series of μFE-models obtained using single- and dual-threshold segmentation enables quantification of the contribution of lower-mineralized tissue to the stiffness of distal radius fractures during healing. This contribution is minor but changes significantly around the time of cast removal. Its course and timing during healing may be clinically relevant. Quantification of the contribution of lower-mineralized tissue to stiffness gives a more complete impression of strength recovery post-fracture than the evaluation of stiffness using a single series of μFE-models.

Diabetes impairs fracture healing through Foxo1 mediated disruption of ciliogenesis

Foxo1 upregulation is linked to defective fracture healing under diabetic conditions. Previous studies demonstrated that diabetes upregulates Foxo1 expression and activation and diabetes impairs ciliogenesis resulting in defective fracture repair. However, the mechanism by which diabetes causes cilia loss during fracture healing remains elusive. We report here that streptozotocin (STZ)-induced type 1 diabetes mellitus (T1DM) dramatically increased Foxo1 expression in femoral fracture calluses, which thereby caused a significant decrease in the expression of IFT80 and primary cilia number. Ablation of Foxo1 in osteoblasts in OSXcretTAFoxo1f/f mice rescued IFT80 expression and ciliogenesis and restored bone formation and mechanical strength in diabetic fracture calluses. In vitro, advanced glycation end products (AGEs) impaired cilia formation in osteoblasts and reduced the production of a mineralizing matrix, which were rescued by Foxo1 deletion. Mechanistically, AGEs increased Foxo1 expression and transcriptional activity to inhibit IFT80 expression causing impaired cilia formation. Thus, our findings demonstrate that diabetes impairs fracture healing through Foxo1 mediated inhibition of ciliary IFT80 expression and primary cilia formation, resulting in impaired osteogenesis. Inhibition of Foxo1 and/or restoration of cilia formation has the potential to promote diabetes-impaired fracture healing.

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.

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.

Filling the gap: a series of 3D-printed titanium truss cages for the management of large, lower limb bone defects in a developing country setting

INTRODUCTION

Large segmental long bone defects are notoriously difficult to manage. Treatment is resource-intensive due to the complexity, cost, and specialized skills required. Truss designs are known for their triangular shapes organized in web configurations. This allows for maximal mechanical strength, the least mass, and a lattice that can be filled with bone graft. Using a truss cage combined with contemporary internal fixation provides immediate stability for bone ingrowth and long-term potential union. The implant is designed using virtual 3D modelling of the patient's bone defect based on a CT scan. The truss cage can be used in a staged procedure combined with Masquelet's induced membrane technique. This study aims to review the outcomes of patient-specific, locally designed 3D titanium truss cages packed with cancellous autograft in treating segmental, long bone defects in the lower limb in a developing country setting.

METHODS

This retrospective series reviewed cases performed at various institutions between January 2019 and March 2022. Parameters assessed included patient demographics, size and location of the defect, time to clinical and radiological union and complications.

RESULTS

Nine cases were included for review, with a mean age of 36 years (range 19-52). Defects ranged from 60 to 205 mm, and eight cases were staged procedures. Eight cases used intramedullary reamings as bone graft. Contemporary intramedullary nails were used for fixation in all cases. No peri- or post-operative complications occurred. All cases progressed to functional union.

CONCLUSION

3D-printed titanium truss cages combined with bone graft appear to be an effective treatment of large bone defects in the lower limb in a developing country setting in the short term. No complications were encountered, but longer follow-up is needed before definitive recommendations can be made.

LEVEL OF EVIDENCE

Level IV (retrospective case series).

Trimalleolar Fractures Treated by Open Reduction Internal Fixation Compared With Arthroscopically Assisted Reduction and Minimally Invasive Surgery

BACKGROUND

Currently, the standard of treatment for trimalleolar (TM) fracture is osteosynthesis through open reduction and internal fixation (ORIF). This study assessed whether arthroscopically assisted reduction and minimally invasive surgery (AARMIS) can be an alternative surgical method for TM fractures.

METHODS

This retrospective cohort study included 49 patients with TM that were surgically treated. 27 patients received ORIF and 22 patients underwent AARMIS . At baseline, we recorded the patient's demographic features, fracture pattern (AO-OTA and Haraguchi classification), and surgical method. For postoperative results, we examined the patient's radiographic outcome, including time to union, quality of fracture reduction, as well as functional outcomes (American Orthopaedic Foot & Ankle Society ankle hindfoot score, ankle range of motion, and visual analog scale of pain) and perioperative complications.

RESULTS

At mean follow-up of 46.6±24.6 (ORIF) and 36.4±18.5 months (AARMIS), both groups had comparable radiographic outcomes. No significant difference in rates of early ankle OA were detected. In terms of functional outcome, VAS pain and AOFAS score at postoperative day 3, postoperative month 3, and at final follow-up were not different. In terms of range of motion, we did not find a significant difference in mean range of motion.

CONCLUSION

Patients with TM fractures treated with AARMIS achieved satisfactory results and was not significantly different in radiographic and functional performance compared with ORIF.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Arthroscopic treatment of stable nonunion, unstable nonunion, or nonunion of the scaphoid with early degenerative radioscaphoid arthritis

BACKGROUND

This study was designed to analyze the clinical follow-up results (minimum of 2 years) in patients with stable nonunion, unstable nonunion, or nonunion of the scaphoid with early degenerative radioscaphoid arthritis (Lichtman classification stage I-III) treated with arthroscopic osteosynthesis with autogenous bone graft.

METHODS

We retrospectively recruited 44 consecutive patients with scaphoid fracture nonunion treated with arthroscopy-assisted percutaneous internal fixation with autogenous bone grafts from January 2010 to November 2019. We recorded union and return to activity and analyzed data with regular clinical follow-up at a mean duration of 33 months (range 24-46 months). Clinical (i.e., visual analog scale pain score, grip strength, and range of motion), radiographic, and functional (Mayo Modified Wrist Score (MMWS)) outcomes at the final follow-up were compared with the preoperative assessments and analyzed in patients with different stages.

RESULTS

We confirmed union in 39 of the 44 patients (88.6%) after a mean 15.4 weeks post-operatively according to clinical examinations and standard radiography. All clinical parameters improved significantly. For the MMWS, there were 25 excellent and 14 good results. Of the 44 patients, 40 (90.9%) returned to work or sports activities at their preinjury levels. Comparisons of the outcomes between patients in different stages of scaphoid nonunion revealed no significant difference in the aspect of union rate, VAS pain score, and functional score improvement.

CONCLUSIONS

Arthroscopic osteosynthesis with autogenous bone grafts is a reliable and minimally invasive method for achieving nonunion healing and improving clinical outcomes in stage I-III scaphoid nonunion.

LEVEL OF EVIDENCE

Level IV, case series.

Does matching degree matter for proximal femoral intramedullary nail on reoperation rate in intertrochanteric fractures?

INTRODUCTION

Previous articles reported on the tip-apex distance, lag screw placement, fracture pattern, reduction quality, osteoporosis and other factors associated with second surgery. The current study focused on investigating the association of the matching degree between proximal femoral intramedullary nail and femoral medullary cavity on reoperation rate.

PATIENTS AND METHODS

A retrospective cohort study was conducted. It included patients with intertrochanteric fracture who were treated with proximal femoral anti-rotatory intramedullary nail (PFNA) between January 2016 and April 2021. The gap between the intramedullary nail and the femoral medullary cavity was equal to the difference in diameter between the two. According to the gap size, all patients were divided into three groups, as follows: high-matching group: gap ≤ 2 mm; middle-matching group: 2 < gap < 4 mm; and low-matching group: gap ≥ 4 mm. The mean gap was measured through standard images. The primary observational index was whether the reoperation was needed, and secondary observational indexes included operative time, length of hospital stay. Patient characteristics were recorded, as follows: age, sex, follow-up time, fracture pattern, reduction grade and length of intramedullary nail.

RESULTS

A total of 203 eligible patients were recorded, including 78 males (38.4%) and 125 females (61.6%). They had a mean age of 77.8 ± 9.9 years old and an average follow-up time of 58.1 ± 24.0 weeks. Twenty-seven patients (13.3%) needed a second operation. Coxa varus combined with screw cutting was the most common reason for reoperation (11 cases). Unstable fracture pattern with poor reduction grade tended to contribute to reoperation, whose odds ratio (OR) was 6.61 (95% confidence interval [CI], 1.98-22.09; P = 0.002). The three groups had 11 cases (13.7%), 12 cases (13.8%) and 4 cases (11.1%) of reoperation, respectively, and logistic regression showed no significant association was noted between matching degree of intramedullary nail and reoperation rate.

CONCLUSIONS

The matching degree between proximal femoral intramedullary nail and femoral medullary cavity did not seem to be an important factor for reoperation, which offered more options of intramedullary nail size intraoperatively and reduced implants stock from inventory.

Solid locked intramedullary nailing for expeditious return of bone-setting-induced abnormal fracture union victims to work in South-western Nigeria

Wage earning in low- and middle-income countries (LMICs) is predominantly through physical labour. Consequently, limb-related disabilities caused by abnormal fracture unions (AFUs) preclude gainful employment and perpetuate the cycle of poverty. Many AFUs result from traditional bone-setting (TBS), a pervasive treatment for long bone fractures in LMICs. The objective of this study was to accentuate the expediency of solid locked intramedullary nail in the early restoration of victims of TBS-induced abnormal fracture unions (AFUs) to their pre-injury functioning, including work. One hundred AFUs in 98 patients treated with a solid locked intramedullary nail in our center over a period of 7 years were prospectively studied. We found the mean age to be 47.97 years. Males constituted 63.9% of the patients' population. Atrophic non-union accounted for 54.1% of the AFUs. The mean fracture-surgery interval was 21.30 months. By the 12th post-operative week, more than 75% of the fractures had achieved knee flexion/shoulder abduction beyond 90°, were able to squat and smile (or do shoulder abduction-external rotation), and were able to bear weight fully. The study demonstrated the expediency of solid locked nail in salvaging TBS-induced abnormal fracture unions in a way that permitted early return to pre-injury daily activities and work, thereby reducing fracture-associated poverty.

Co-registered speckle contrast optical tomography and frequency domain-diffuse optical tomography for imaging of the fifth metatarsal

A co-registered speckle contrast optical tomography and frequency domain-diffuse optical tomography system has been designed for imaging total hemoglobin concentration, blood oxygenation, and blood flow with the future aim of monitoring Jones fractures of the fifth metatarsal. Experimental validation was performed using both in vitro tissue-mimicking phantoms and in vivo cuff occlusion experiments. Results of these tissue phantom experiments ensure accurate recovery of three-dimensional distributions of optical properties and flow. Finally, cuff occlusion experiments performed on one healthy human subject demonstrate the system's ability to recover both decreasing tissue oxygenation and blood flow as caused by an arterial occlusion.

Effectiveness and Biomechanical Analysis of the Ortho-Bridge System on Femoral Fracture Healing: A Retrospective Analysis

BACKGROUND

Among the surgical methods for femoral fractures, the Ortho-Bridge System (OBS) appears to heal fractures via an uncommon process. We compared its effectiveness and biomechanical aspects to those of a locking compression plate (LCP) and explained the healing process demonstrated by the OBS.

METHODS

Eleven femoral shaft fracture cases treated with OBS between July 2017 and May 2020 were retrospectively reviewed. Clinical and radiographic data were collected during regular postoperative follow-up visits and assessed via the Harris Hip Score and Knee Society Score. We performed biomechanical experiments of OBS. We simulated different fracture conditions and selected appropriate screw holes at the fracture's far and near segments. The OBS module was placed according to the position of LCP's locking hole at both ends of the fracture; then, a static three-point bending test was performed.

RESULTS

All patients had contralateral callus growth with secondary fracture healing. Healing time was 3-5 months with excellent hip and knee function. When the key screw distance was 22-34 mm, the OBS was significantly less stiff than the LCP (P < 0.05). The stiffness of LCP and OBS decreased significantly when the key screw distance was 49-82 mm, with the LCP being slightly stronger (P < 0.05).

CONCLUSIONS

Femoral shaft fracture treatment with OBS demonstrated secondary healing. When the distance between the key screws was 20-40 mm, the elasticity was higher in OBS than in LCP, possibly producing axial micro-motion to stimulate callus formation and promote fracture healing, which differ from the plate's primary healing process.

Design considerations for piezocomposite materials for electrical stimulation in medical implants

Incidence of non-union following long bone fracture fixation and spinal fusion procedures is increasing, and very costly for patients and the medical system. Direct current (DC) electrical stimulation has shown success as an adjunct therapy to stimulate bone healing and increase surgery success rates, though drawbacks of current devices and implantable battery packs have limited widespread use. Energy harvesting utilising piezoelectric materials has been widely studied for powering devices without a battery, and a preclinical animal study has shown efficacy of a piezocomposite spinal fusion implant resulting in faster, more robust fusion. Most piezoelectric energy harvesters operate most effectively at high frequencies, limiting power generation from loads experienced by orthopaedic implants during human motion. This work characterises the efficient power generation capability of a novel composite piezoelectric material under simulated walking loads. Building on compliant layer adaptive composite stacks (CLACS), the power generation of mixed-mode CLACS (MMCLACS) is defined. Utilising poling direction to capitalise on in-plane strain generation due to compliant layer expansion, MMCLACS significantly increased power output compared to a standard piezo stack. The combination of radial and through-thickness poled piezoelectric elements within a stack to create MMCLACS significantly increases power generation under low-frequency dynamic loads. This technology can be adapted to a variety of architectures and assembled as a load-bearing energy harvester within current implants. MMCLACS integrated with implants would provide enough power to deliver bone healing electrical stimulation directly to the fusion site, decreasing non-union rates, and also could provide quantitative assessment of healing progression through load sensing.

Treatment of distal radius fractures using a cemented K-wire frame

BACKGROUND

This retrospective study included an alternative treatment for types A2, A3, and B1 distal radius fractures using percutaneous fixation with a cemented K-wire frame.

METHODS

From January 2017 to January 2020, 78 patients with distal radius fractures were treated with percutaneous internal fixation using a cemented K-wire frame. There were 47 male patients and 31 female patients. The fractures were classified into types A2 (n = 10), A3 (n = 46), and B1 (n = 22). X-rays were taken immediately after surgery and after the bone had healed. Wrist function was assessed using the Mayo Wrist Score (90-100, excellent; 80-90, good; 60-80, satisfactory; < 60, poor). Patient satisfaction was assessed using the 10-cm visual analog scale.

RESULTS

Neither fixation failure nor K-wire migration was found (P > 0.05). Osteomyelitis was not observed in this series. All patients achieved bone healing after a mean of 4.5 weeks (range, 4 to 8 weeks). Follow-up lasted a mean of 27 months (range, 24 to 33 months). The mean score of wrist function was 97 (range, 91 to 100). Among them, 66 results were excellent and 12 results were good. The mean patient satisfaction was 10 cm (range, 8 to 10 cm).

CONCLUSIONS

Percutaneous fixation with cemented K-wire frame is a safe and preferred choice for the treatment of types A2, A3, and B1 distal radius fractures. The frame provides support to prevent wire migration. The fixation technique is a minimally invasive procedure that is easy to perform.

LEVEL OF EVIDENCE

Therapeutic study, Level IVa.

The Effect of Hand Dominance, Age, Gender, Fracture Comminution and ASA Status on Time to Fracture Healing Following Surgical Fixation of Distal Radius Fractures

Background: There is recent renewed interest in the effect of hand dominance on distal radius fractures. Current studies focus on functional or patient-reported outcomes, with lack of studies pertaining to radiological outcomes. The primary aim of this study is to examine the effect of hand dominance on time to fracture healing following surgical fixation of distal radius fracture. We also looked at the effect of age, gender, fracture comminution and American Society of Anaesthesiologists (ASA) status on time to fracture healing.

Methods: Patients who underwent distal radius fracture fixation surgery in our department from 1 January 2015 to 31 December 2015 were included. Time to fracture healing was taken from the day of surgery to when radiographic union was present as evidence by bridging callus or osseous bone. We looked at the effect of hand dominance, age, gender, fracture comminution and ASA status on time to fracture healing.

Results: One hundred and forty-five consecutive patients (80 females and 65 males) had a mean period of 56.2 ± 41.8 days to fracture healing post-operatively. Patients with dominant hand injury had a shorter duration to fracture healing than patients with non-dominant hand injury (mean 47.3 ± 31.1 days versus 62.1 ± 46.8 days, p = 0.023). Patients ≥ 65 years and with pre-existing medical conditions (ASA Class II and above) had a longer duration to fracture healing (mean 63.7 ± 53.0 days versus 51.9 ± 33.4 days, p = 0.036 and mean 47.9 ± 30.0 days versus 62.0 ± 47.7 days, p = 0.016, respectively). In addition, patients with comminuted fractures took longer to heal than patients with non-comminuted fractures (mean 57.6 ± 33.4 days versus 48.3 ± 20.8 days, p = 0.038).

Conclusion: Time to fracture healing post distal radius fracture fixation surgery was significantly related to hand dominance, as well as age, ASA classification and fracture configuration. Dominant wrist injuries had shorter time to fracture healing.

Level of Evidence: Level IV (Therapeutic)

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.

Animal models of impaired long bone healing and tissue engineering- and cell-based in vivo interventions

Bone healing after injury typically follows a systematic process and occurs spontaneously under appropriate physiological conditions. However, impaired long bone healing is still quite common and may require surgical intervention. Various complications can result in different forms of impaired bone healing including nonunion, critical-size defects, or stress fractures. While a nonunion may occur due to impaired biological signaling and/or mechanical instability, a critical-size defect exhibits extensive bone loss that will not spontaneously heal. Comparatively, a stress fracture occurs from repetitive forces and results in a non-healing crack or break in the bone. Clinical standards of treatment vary between these bone defects due to their pathological differences. The use of appropriate animal models for modeling healing defects is critical to improve current treatment methods and develop novel rescue therapies. This review provides an overview of these clinical bone healing impairments and current animal models available to study the defects in vivo. The techniques used to create these models are compared, along with the outcomes, to clarify limitations and future objectives. Finally, rescue techniques focused on tissue engineering and cell-based therapies currently applied in animal models are specifically discussed to analyze their ability to initiate healing at the defect site, providing information regarding potential future therapies. In summary, this review focuses on the current animal models of nonunion, critical-size defects, and stress fractures, as well as interventions that have been tested in vivo to provide an overview of the clinical potential and future directions for improving bone healing.

Bone turnover markers as surrogates of fracture healing after intramedullary fixation of tibia and femur fractures

Aims

Bone turnover markers (BTMs) follow distinct trends after fractures and limited evidence suggests differential levels in BTMs in patients with delayed healing. The effect of vitamin D, and other factors that influence BTMs and fracture healing, is important to elucidate the use of BTMs as surrogates of fracture healing. We sought to determine whether BTMs can be used as early markers of delayed fracture healing, and the effect of vitamin D on BTM response after fracture.

Methods

A total of 102 participants aged 18 to 50 years (median 28 years (interquartile range 23 to 35)), receiving an intramedullary nail for a tibial or femoral shaft fracture, were enrolled in a randomized controlled trial comparing vitamin D₃ supplementation to placebo. Serum C-terminal telopeptide of type I collagen (CTX; bone resorption marker) and N-terminal propeptide of type I procollagen (P1NP; bone formation marker) were measured at baseline, six weeks, and 12 weeks post-injury. Clinical and radiological fracture healing was assessed at three months.

Results

CTX and P1NP concentrations peaked at six weeks in all groups. Elevated six-week CTX and P1NP were associated with radiological healing at 12 weeks post-injury (odds ratio (OR) 10.5; 95% confidence interval 2.71 to 53.5, p = 0.002). We found no association between CTX or P1NP and functional healing. Baseline serum 25(OH)D showed a weak inverse relationship with P1NP (p = 0.036) and CTX (p = 0.221) at 12 weeks, but we observed no association between vitamin D supplementation and either BTM.

Conclusion

Given the association between six-week BTM concentrations and three-month radiological fracture healing, CTX and P1NP appear to be potential surrogate markers of fracture healing.

Cite this article: Bone Joint Res 2022;11(4):239–250.

Minimally Invasive Distal Chevron Osteotomy for Symptomatic Bunionette: Clinical and Radiologic Results of a 31-Case Retrospective Study

Background

Bunionette is a common forefoot deformity that usually leads to significant discomfort. Multiple surgical techniques have been described for correcting bunionette. The purpose of this study is to analyze the clinical and radiologic outcomes of a new surgical technique via minimally invasive distal Chevron osteotomy of the fifth metatarsal without fixation, trying to find an effective technique with fewer complications.

Methods

We retrospectively analyzed the data of 28 patients (31 feet) who presented with symptomatic bunionette that was resistant to conservative treatment and who underwent surgery at our center from February 2018 to February 2020. A minimum follow-up of 20 months was obtained (mean follow-up 26 months, range 20-37). Clinical results were evaluated using the visual analog scale (VAS) and the American Orthopaedic Foot & Ankle Society (AOFAS) score; 5 different radiologic parameters were analyzed.

Results

After surgery, the mean AOFAS score increased by 29 points (P < .001) and the mean VAS scores decreased by 6 points (P < .001). An adequate radiologic correction was observed with a decrease in the M4-M5 intermetatarsal angle from 10.3 to 4.8 degrees (P < .001), metatarsophalangeal angle by a mean of 16.05 degrees (P < .001), and lateral deviation angle of the fifth metatarsal from 8.5 to 0.97 degrees (P < .001). Moreover, the length of the fifth metatarsal and the forefoot width was reduced (P < .001). The only complication was an asymptomatic delay in bone healing, but a complete bone consolidation was achieved after therapy.

Conclusion

The proposed surgical technique shows a good correction capacity with excellent clinical and radiologic results and low complication rates.Level of Evidence: Level IV, retrospective case series.

Open Ankle Arthrodesis: A Retrospective Analysis Comparing Different Fixation Methods

A wide variation of surgical options, complications, and union rates are reported in the treatment of end-stage ankle arthritis. However, open ankle arthrodesis remains the golden standard for ankle arthritis. The purpose of this study was to evaluate the union rate and complication rate as well as identify potential risk factors for different methods of fixation in patients with end-stage ankle arthritis of different etiology. In total, 42 ankles of 41 patients with ankle osteoarthritis were included for this single-center retrospective study. The mean age was 50 years (range 22-75 years). Twenty patients were treated with screw-fixation, 14 with plate(s) and 8 with intramedullary nail. The results of this study showed an overall union rate of 97.6% (41 of the 42 operated ankles) and an overall complication rate of 21.4% (9 events). The mean follow-up time was 16 months (range 2.5-83.0 months). Complications consisted of 1 nonunion, 4 deep infections, 2 cases of wound dehiscence, 1 delayed union and 1 malalignment of the ankle joint. The plate-fixation group demonstrated significantly higher infections when compared with screw and intramedullary nail fixation (p = .017). There were no other significant variables for incidence of complications between patients in the uncomplicated and complicated group. This study achieved good clinical results for different methods of fixation in open ankle arthrodesis. In specific, the use of intramedullary nail provides excellent results for end-stage ankle arthritis with high union rate and a low complication rate.

Anti-Glide Plate Fixation for Lateral Malleolus Fractures by Minimally Invasive Technique in Geriatric Patients

The objective was to evaluate the functional outcomes of anti-glide fixation by minimally invasive plate osteosynthesis (MIPPO) in lateral malleolus ankle fractures.

The study was a retrospective cohort study conducted at a single trauma center. We reviewed 39 patients >60 years old with either isolated or non-isolated lateral malleolus Weber B ankle fractures.

The main outcome measures were postoperative functional assessment performed with the American Orthopaedic Foot and Ankle Society (AOFAS) and Short Musculoskeletal Functional Assessment (SMFA) scores. Our results showed that the mean time to surgery was 1 day. Seventeen patients underwent surgery within 24 hours after sustaining the injury. The mean AOFAS and SMFA scores were 87.8 and 209.7, respectively. No patient developed implant failure or wound complications.

It was concluded that the anti-glide plating of the lateral malleolus had better functional outcomes compared to lateral plating by open reduction and internal fixation (ORIF), as shown by the higher AOFAS scores and fewer postoperative complications.

The intersection of fracture healing and infection: Orthopaedics research society workshop 2021

Infection is a common cause of impaired fracture healing. In the clinical setting, definitive fracture treatment and infection are often treated separately and sequentially, by different clinical specialties. The ability to treat infection while promoting fracture healing will greatly reduce the cost, number of procedures, and patient morbidity associated with infected fractures. In order to develop new therapies, scientists and engineers must understand the clinical need, current standards of care, pathologic effects of infection on fractures, available preclinical models, and novel technologies. One of the main causes of poor fracture healing is infection; unfortunately, bone regeneration and infection research are typically approached independently and viewed as two separate disciplines. Here, we aim to bring these two groups together in an educational workshop to promote research into the basic and translational science that will address the clinical challenge of delayed fracture healing due to infection. Statement of clinical significance: Infection and nonunion are each feared outcomes in fracture care, and infection is a significant driver of nonunion. The impact of nonunions on patie[Q2]nt well-being is substantial. Outcome data suggests a long bone nonunion is as impactful on health-related quality of life measures as a diagnosis of type 1 diabetes and fracture-related infection has been shown to significantly l[Q3]ower a patient's quality of life for over 4 years.  Although they frequently are associated with one another, the treatment approaches for infections and nonunions are not always complimentary and cannot be performed simultaneously without accepting tradeoffs. Furthermore, different clinical specialties are often required to address the problem, the orthopedic surgeon treating the fracture and an infectious disease specialist addressing the sources of infection. A sequential approach that optimizes treatment parameters requires more time, more surgeries, and thus confers increased morbidity to the patient. The ability to solve fracture healing and infection clearance simultaneously in a contaminated defect would benefit both the patient and the health care system.

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.

Radiographic Outcomes Following the Suture Fixation of Mid-pole Patellar Fractures

Background

Mid-pole patellar fractures are typically fixed with metal implants in the conventional “11-8” tension band construct. However, this technique is fraught with numerous implant-related complications. The aim of this study is to evaluate the union rate following “all-suture” fixation of mid-pole patellar fractures.

Methods

We retrospectively evaluated a consecutive case series of patients with displaced mid-pole patella fractures treated with “all-suture” fixation in our institution. Fifteen cases were available for this study. The average age was 61.5 years. Clinical and radiological outcomes were evaluated. Union time, complications, and revision rate were recorded. The minimum follow-up was one year.

Results

There were eight males and seven females, with a mean age of 61.5 ± 13.3 years. Fourteen out of 15 cases (93.3%) achieved radiographic union at 12 weeks postoperatively. The average time to radiographic union was 8.0 ± 2.7 weeks. Five cases (33.3%) had an increase in the fracture gap (>2 mm) at around four to six weeks postoperatively. Four of these cases had an eventual union, whereas one patient had fibrous non-union. There was one case of superficial surgical site infection and one case of infected hematoma. None of the patients required revision surgery.

Conclusion

“All-suture” fixation of mid-pole transverse patellar fractures is a safe and viable alternative to the conventional “11-8” tension band constructs with metal implants, with good union time, rates, and added benefits of not requiring additional surgery for implant removal.

Vibration therapy as an intervention for enhancing trochanteric hip fracture healing in elderly patients: a randomized double-blinded, placebo-controlled clinical trial

BACKGROUND

There are more than 300,000 hip fractures yearly in the USA with mortality rates of 20% within 1 year. The treatment of osteoporotic fractures is a major challenge as bone quality is poor, and healing is expected to delay due to the impaired healing properties with respect to bone formation, angiogenesis, and mineralization. Enhancement of osteoporotic fracture healing and function is therefore critical as a major goal in modern fracture management. Previous pre-clinical studies have shown that low-magnitude high-frequency vibration (LMHFV) accelerates osteoporotic fracture healing. The objective of this study is to investigate the effect of LMHFV on accelerating trochanteric hip fracture healing and functional recovery.

METHODS

This is a randomized, double-blinded, placebo-controlled clinical trial to evaluate the effect of LMHFV in accelerating trochanteric hip fracture healing. All fractures undergo cephalomedullary nail fixation. The primary outcome of this study is time to fracture healing by X-ray. Computed tomography (CT) and dual-energy X-ray absorptiometry (DXA) will also be performed. Blood circulation at the fracture site will be assessed by dynamic perfusion magnetic resonance (MR). Clinical results include functional recovery by muscle strength, timed up and go test (TUG), quality of life questionnaire (SF-36), balancing, falls, and mortality.

DISCUSSION

Previous animal studies have demonstrated LMHFV to improve both normal and osteoporotic fracture healing by accelerating callus formation and mineralization. The mechanical stimulation stimulates angiogenesis by significantly enhancing vascular volume and blood flow velocity. This is the first study to translate LMHFV to enhancing hip fracture healing clinically. Positive results would provide a huge impact in the recovery of hip fracture patients and save healthcare costs.

TRIAL REGISTRATION

Clinicaltrials.gov NCT04063891. Registered on August 21, 2019.

Diabetes impairs fracture healing through disruption of cilia formation in osteoblasts

Diabetes-associated fracture risk and impaired fracture healing represents a serious health threat. It is well known that type 1 diabetes mellitus (T1DM) impairs fracture healing due to its effect on osteoblasts and their progenitor cells. Previous studies have showed that primary cilia and intraflagellar transport protein 80 (IFT80) are critical for bone formation. However, whether TIDM impairs fracture healing due to influencing ciliary gene expression and cilia formation is unknown. Here, we investigated the effect of T1DM on primary cilia in a streptozotocin induced diabetes mouse model and examined the impact of cilia on fracture healing in osteoblasts by deletion of IFT80 in osteoblast linage using osterix (OSX)-cre (OSXcretTAIFT80f/f). The results showed that diabetes inhibited ciliary gene expression and primary cilia formation to an extent that was similar to normoglycemic mice with IFT80 deletion. Moreover, diabetic mice and normoglycemic mice with cilia loss in osteoblasts (OSXcretTAIFT80f/f) both exhibited delayed fracture healing with significantly reduced bone density and mechanical strength as well as with reduced expression of osteoblast markers, decreased angiogenesis and proliferation of bone lining cells at the fracture sites. In vitro studies showed that advanced glycation end products (AGEs) downregulated IFT80 expression in osteoblast progenitors. Moreover, AGEs and IFT80 deletion significantly reduced cilia number and length which inhibited differentiation of primary osteoblast precursors. Thus, this study for the first time report that primary cilia are essential for bone regeneration during fracture healing and loss of cilia caused by diabetes in osteoblasts resulted in defective diabetic fracture healing.

Ablation of Proliferating Osteoblast Lineage Cells After Fracture Leads to Atrophic Nonunion in a Mouse Model

Nonunion is defined as the permanent failure of a fractured bone to heal, often necessitating surgical intervention. Atrophic nonunions are a subtype that are particularly difficult to treat. Animal models of atrophic nonunion are available; however, these require surgical or radiation-induced trauma to disrupt periosteal healing. These methods are invasive and not representative of many clinical nonunions where osseous regeneration has been arrested by a "failure of biology". We hypothesized that arresting osteoblast cell proliferation after fracture would lead to atrophic nonunion in mice. Using mice that express a thymidine kinase (tk) "suicide gene" driven by the 3.6Col1a1 promoter (Col1-tk), proliferating osteoblast lineage cells can be ablated upon exposure to the nucleoside analog ganciclovir (GCV). Wild-type (WT; control) and Col1-tk littermates were subjected to a full femur fracture and intramedullary fixation at 12 weeks age. We confirmed abundant tk+ cells in fracture callus of Col-tk mice dosed with water or GCV, specifically many osteoblasts, osteocytes, and chondrocytes at the cartilage-bone interface. Histologically, we observed altered callus composition in Col1-tk mice at 2 and 3 weeks postfracture, with significantly less bone and more fibrous tissue. Col1-tk mice, monitored for 12 weeks with in vivo radiographs and micro-computed tomography (μCT) scans, had delayed bone bridging and reduced callus size. After euthanasia, ex vivo μCT and histology showed failed union with residual bone fragments and fibrous tissue in Col1-tk mice. Biomechanical testing showed a failure to recover torsional strength in Col1-tk mice, in contrast to WT. Our data indicates that suppression of proliferating osteoblast-lineage cells for at least 2 weeks after fracture blunts the formation and remodeling of a mineralized callus leading to a functional nonunion. We propose this as a new murine model of atrophic nonunion. © 2021 American Society for Bone and Mineral Research (ASBMR).

One-Third Tubular Plate Remains a Clinically Good Option in Danis-Weber Type B Distal Fibular Fracture Fixation

OBJECTIVE

To compare the clinical outcomes of locking plate (LP) and non-locking one-third tubular plate (TP) fixation, and to provide guidance on plate selection for Danis-Weber type B distal fibular fracture treatment.

METHODS

In total, 83 patients who underwent plate fixation for Danis-Weber type B distal fibular fractures between March 2013 and July 2018 were retrospectively reviewed: 41 (49.0%) received LPs and 42 (51.0%) received TPs. Patients' demographic data, follow-up durations, the proportion of comminuted fractures, and ankle range of motion were investigated. The American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale, Karlsson scale, Foot and Ankle Ability Measure (FAAM), and Lower Extremity Functional Scale (LEFS) scores were assessed. The radiographic union progression and implant removal time were evaluated, along with postoperative complications. Data from the LP and TP groups were compared statistically.

RESULTS

The mean patient ages were 53.3 ± 17.5 years (range, 16-80 years) and 47.6 ± 17.0 years (range, 14-68 years) in the LP and TP groups, respectively (P > 0.05). The gender distribution did not differ significantly between groups (P > 0.05). Other demographic data also did not differ significantly between groups (P > 0.05). The mean follow-up durations were 16.8 ± 7.7 months (range, 13.0-19.0 months) in the LP group and 16.1 ± 6.2 months (range, 12.0-20.0 months) in the TP group (P > 0.05). Comminuted fractures were observed in 18 of 41 (43.9%) patients with LP and 10 of 42 (23.8%) patients with TP (P > 0.05). Forward bending ankle dorsiflexion was possible at the final follow-up in 82.9% and 85.7% of LP and TP patients, respectively (P > 0.05). The AOFAS ankle-hindfoot scale, Karlsson scale, FAAM, and LEFS scores did not differ significantly between groups at the final follow-up (P > 0.05). The pre-fracture and final postoperative scores on these four instruments did not differ significantly in the LP or TP group (P > 0.05). The mean times to radiographic union progression were 13.5 ± 7.1 weeks and 15.1 ± 10.2 weeks in the LP and TP groups, respectively (P > 0.05). The mean times to implant removal surgery reaffirming solid union were 15.6 ± 5.5 months and 14.8 ± 4.9 months in the LP and TP groups, respectively (P > 0.05). Hardware irritation was detected in five patients in the LP group (12.2%) and three in the TP group (7.1%) (P > 0.05). One patient in the LP group and two in the TP group developed superficial wound infections, which resolved without further surgical intervention.

CONCLUSION

Conventional TP remains a good option for the fixation of Danis-Weber type B distal fibular fractures, regardless of the biomechanical properties.

Avascular necrosis of the first metatarsal head in a young female adult: A case report and review of literature

BACKGROUND

This case study describes an atypical presentation of avascular necrosis (AVN) of the first metatarsal head, which is largely unfounded in the literature.

CASE SUMMARY

A healthy 24-year-old female initially presented with pain at the first metatarsophalangeal joint (MTPJ) and was diagnosed with AVN by physical examination and magnetic resonance imaging. The patient demonstrated atypically poor progress in recovery, despite being in otherwise good health and being of young age, with no history of corticosteroid or alcohol use. The patient also did not have any history or clinical features of autoimmune disease or vasculitis, such as systemic lupus erythematosus. The patient was managed with conservative treatment for 18 mo, which allowed for gradual return of full range of motion of the first MTPJ and subsiding pain, permitting the patient to return to high-intensity sports training and full weight-bearing. Throughout her recovery, many differential diagnoses were ruled out through specific investigations leading to further reinforcement of the diagnosis of AVN of the 1^st metatarsal head.

CONCLUSION

Atypical AVN may occur with no predisposing risk factors. Treatment is mainly conservative, with unclear guidelines in literature on management.

Autogenous Onlay Graft with Compression Plate for Treatment of Persistent Humeral Shaft Aseptic Non-union with Failed Previous Surgery

BACKGROUND: The humeral shaft fractures have a good rate of union, despite this fact, still there is a significant rate of nonunion after nonoperative treatment and more often after operative treatment. AIM: The aim of the study is to evaluate the autogenous onlay graft with compression plate for treatment of persistent humeral shaft non-union with failed previous surgery both radiological and functional outcome. MATERIALS AND METHODS: A prospective study on twenty patients having persistent aseptic non-union age between 20 and 60 years old, after failed surgical treatment of fractures humeral shaft in Al-Zahra teaching and Al-Kindy teaching hospitals, while infected nonunion, diabetes mellitus, secondary metastasis, smoking, alcoholism, and patients on long medication with corticosteroid were excluded from the study. All our patients were treated with corticocancellous onlay bone grafting harvesting from the ipsilateral upper tibia and compression plating (graft parallel to plate) and follow-up for at least 18 months post-operative to evaluate both radiology and functional using Mayo elbow performance index. RESULTS: All the patients ended with a solid union without hardware failure, and no one patient needs further surgery, even with significant resorption of the graft, there is a good chance of graft re-calcification and solid union with good to excellent functional outcome. CONCLUSION: Very successful solid union results achieve in those patients with established aseptic nonunion and pseudoarthrosis of the humerus.

Open plate fixation versus nailing for humeral shaft fractures: a meta-analysis and systematic review of randomised clinical trials and observational studies

PURPOSE

This meta-analysis compares open reduction and internal fixation with a plate (ORIF) versus nailing for humeral shaft fractures with regard to union, complications, general quality of life and shoulder/elbow function.

METHODS

PubMed/Medline/Embase/CENTRAL/CINAHL was searched for observational studies and randomised clinical trials (RCT). Effect estimates were pooled across studies using random effects models. Results were presented as weighted odds ratio (OR) or risk difference (RD) with corresponding 95% confidence interval (95% CI). Subgroup analysis was performed stratified for study design (RCTs and observational studies).

RESULTS

Eighteen observational studies (4906 patients) and ten RCT's (525 patients) were included. The pooled effect estimates of observational studies were similar to those obtained from RCT's. More patients treated with nailing required re-intervention (RD 2%; OR 2.0, 95% CI 1.0-3.8) with shoulder impingement being the most predominant indication (17%). Temporary radial nerve palsy secondary to operation occurred less frequently in the nailing group (RD 2%; OR 0.4, 95% CI 0.3-0.6). Notably, all but one of the radial nerve palsies resolved spontaneously in each groups. Nailing leads to a faster time to union (mean difference - 1.9 weeks, 95% CI - 2.9 to - 0.9), lower infection rate (RD 2%; OR 0.5, 95% CI 0.3-0.7) and shorter operation duration (mean difference - 26 min, 95% CI - 37 to - 14). No differences were found regarding non-union, general quality of life, functional shoulder scores, and total upper extremity scores.

CONCLUSION

Nailing carries a lower risk of infection, postoperative radial nerve palsy, has a shorter operation duration and possibly a shorter time to union. Shoulder impingement requiring re-intervention, however, is an inherent disadvantage of nail fixation. Notably, absolute differences are small and almost all patients with radial nerve palsy recovered spontaneously. Satisfactory results can be achieved with both treatment modalities.

Restoration of Stiffness During Fracture Healing at the Distal Radius, Using HR-pQCT and Finite Element Methods

Finite element analysis (FE) coupled with high-resolution peripheral quantitative computed tomography (HR-pQCT) allows for noninvasive in vivo assessment of fracture stiffness at peripheral locations including the distal radius. Previous studies have reported the ability of FE analysis to capture significant longitudinal changes in fracture stiffness. We hypothesized that continuum-based FE methods are necessary to capture significant changes in FE-estimated stiffness in men and women, with closed reductions and casting, over the course of their fracture healing process. The primary aim of the study was to evaluate the performance of 3 micro-FE (μFE) methods, 2 density-based (continuum) methods, and a homogeneous method. A total of 30 participants with stable distal radius fractures completed follow-ups at 2, 4, 6, 8, 12, and 26 weeks postfracture. Participants had their fractured wrist scanned using HR-pQCT at each follow-up; the contralateral wrist was also scanned at the initial assessment to represent baseline conditions. Images were used to generate continuum and homogeneous µFE models. Uniaxial compression and torsional tests were completed, with apparent stiffness determined as the primary outcome measure. Stiffness of the fractured wrist was compared to stiffness of the uninjured contralateral wrist to quantify the change in stiffness. Days since fracture significantly predicted change in stiffness for continuum and homogeneous µFE methods (p < 0.05). Continuum µFE methods appeared to account for partially mineralized tissues, resulting in a graduated recovery of stiffness (1% per week). Homogeneous µFE methods were more sensitive to stages of healing progression, resulting in a faster recovery of stiffness (3% per week). Our findings demonstrate the capability of µFE to capture the restoration of stiffness at the fractured side to prefracture stiffness in men and women, up to 6 months postfracture.

Measuring Orthopedic Plate Strain to Track Bone Healing Using a Fluidic Sensor Read via Plain Radiography

OBJECTIVE

We describe a fluidic X-ray visualized strain indicator under applied load (X-VISUAL) to quantify orthopedic plate strain and inform rehabilitative care.

METHODS

The sensor comprises a polymeric device with a fluidic reservoir filled with a radio-dense fluid (cesium acetate) and an adjoining capillary wherein the liquid level is measured. A stainless-steel lever attaches to the plate and presses upon the acrylic bulb with a displacement proportional to plate bending strain. The sensor was attached to a plate in a Sawbones composite tibia mimic and a human cadaveric tibia. An osteotomy model (5 mm gap) was used to simulate an unstable fracture, and allograft repair to simulate a stiffer healed fracture. The cadaveric and Sawbones tibia were cyclically loaded five times (0-400 N) using a mechanical test stand, and fluid displacement was measured from plain radiographs.

RESULTS

The sensor displayed reversible and repeatable behavior with a slope of 0.096 mm/kg and fluid level noise of 50-80 micrometer (equivalent to 5-10 N). The allograft-repaired composite fracture was 13 times stiffer than the unstable fracture.

CONCLUSION

An analysis of prior external fracture fixation studies and fatigue curves for internal plates indicates that the threshold for safe weight bearing should be 1/5^th-1/10^th of the initial bending for an unstable fracture. The precision of our device (<2% body weight) should thus be sufficient to track fracture healing from unstable through safe weight bearing.

SIGNIFICANCE

The X-VISUAL fluidic sensor enables orthopedic plate strain quantification to monitor facture healing via X-ray imaging.

Scoring systems for early prediction of tibial fracture non-union: an update

Purpose

To evaluate the available tibial fracture non-union prediction scores and to analyse their strengths, weaknesses, and limitations.

Methods

The first part consisted of a systematic method of locating the currently available clinico-radiological non-union prediction scores. The second part of the investigation consisted of comparing the validity of the non-union prediction scores in 15 patients with tibial shaft fractures randomly selected from a Level I trauma centre prospectively collected database who were treated with intramedullary nailing.

Results

Four scoring systems identified: The Leeds-Genoa Non-Union Index (LEG-NUI), the Non-Union Determination Score (NURD), the FRACTING score, and the Tibial Fracture Healing Score (TFHS). Patients demographics: Non-union group: five male patients, mean age 36.4 years (18–50); Union group: ten patients (8 males) with mean age 39.8 years (20–66). The following score thresholds were used to calculate positive and negative predictive values for non-union: FRACTING score ≥ 7 at the immediate post-operative period, LEG-NUI score ≥ 5 within 12 weeks, NURD score ≥ 9 at the immediate post-operative period, and TFHS < 3 at 12 weeks. For the FRACTING, LEG-NUI and NURD scores, the positive predictive values for the development of non-union were 80, 100, 40% respectively, whereas the negative predictive values were 60, 90 and 90%. The TFHS could not be retrospectively calculated for robust accuracy.

Conclusion

The LEG-NUI had the best combination of positive and negative predictive values for early identification of non-union. Based on this study, all currently available scores have inherent strengths and limitations. Several recommendations to improve future score designs are outlined herein to better tackle this devastating, and yet, unsolved problem.

Ultrasound Frequency-Based Monitoring for Bone Healing

Correct assessment of the bone healing process is required for the management of limb immobilization during the treatment of bone injuries, including fractures and defects. Although the monitoring of bone healing using ultrasound poses several advantages regarding cost and ionizing radiation exposure compared with other dominant imaging methods, such as radiography and computed tomography (CT), traditional ultrasound B-mode imaging lacks reliability and objectivity. However, the body structures can be quantitatively observed by ultrasound frequency-based methods, and therefore, the disadvantages of B-mode imaging can be overcome. In this study, we created a femoral bone hole model of a rat and observed the bone healing process using the quantitative ultrasound method and micro-CT, which provides a reliable assessment of the tissue microstructure of the bone. This study analyzed the correlation between these two assessments. The results revealed that the quantitative ultrasound measurements correlated with the CT measurements for rat bone healing. This ultrasound frequency-based method could have the potential to serve as a novel modality for quantitative monitoring of bone healing with the advantages of being less invasive and easily accessible. Impact statement Bone healing monitoring with ultrasound is advantageous as it is less invasive and easily accessible; however, the traditional B-mode method lacks reliability and objectivity. This study demonstrated that the proposed ultrasound frequency-based monitoring method can quantitatively observe bone healing and strongly correlates with the computed tomography measurements for rat bone healing. This method has the potential to become a reliable modality for monitoring bone healing.

Short and long-term outcomes of three-dimensional printed surgical guides and virtual surgical planning versus conventional methods for fibula free flap reconstruction of the mandible: Decreased nonunion and complication rates

BACKGROUND

To determine whether virtual surgical planning and three-dimensional printed cutting guides (3D/VSP) improved radiographic bone union compared to conventional methods (CM) in fibula free flap (FFF) reconstruction of the mandibles.

METHODS

Retrospective study from the years 2000-2018 at a tertiary hospital. Osseous union was evaluated by a radiologist blinded to each patient's treatment.

RESULTS

Two hundred sixty patients who underwent FFF tissue transfer, 28 with VSP and 3D cutting guides. Bony union was not achieved in 46 (20%) patients who underwent CM compared to 1 (4%) of patients with VSP and guides (p = 0.036). FFF complication was significantly higher in CM with 87 patients (38%) compared to three patients (11%) in 3D/VSP (p = 0.005). Median time to bony union for patients who underwent CM was 1.4 years compared to 0.8 years in 3D/VSP.

CONCLUSIONS

3D/VSP reduced the rate of radiographic nonunion and flap-related complications in FFF reconstruction for mandibular defects.

Reliability of RUST and modified RUST scores for evaluation of union in pediatric and adult femoral shaft fractures

OBJECTIVE

This study aimed to determine the reliability levels of the radiographic union scale for tibial fractures (RUST) and the modified version of the system, mRUST, for femoral shaft fractures in pediatric and adult patients and to evaluate the value of the scores for total and each cortex in the decision making on fracture union.

METHODS

A total of 15 orthopedic surgeons scored the radiographs of 24 pediatric and 24 adult patients with femoral shaft fractures that were obtained at 0, 4, 8, 12, and 16 postoperative weeks treated with elastic stable intramedullary nail in pediatric patients and locked intramedullary nail in adult patients using the RUST and mRUST scores. Intra-class correlation coefficient (ICC) was used in the evaluation of reliability of the RUST and mRUST scores. The Fleiss kappa (k) coefficient was used in the agreement between evaluators regarding union decision (united or non-united). The thresholds for RUST and mRUST for radiographic union decision were determined. Receiver operating curves were created to evaluate the contribution of total and individual cortical scores in the decision of united or non-united.

RESULTS

Intra- and inter-rater reliabilities of mRUST (ICC: 0.92 and 0.86, respectively) were slightly higher than those of RUST (ICC: 0.81 and 0.77, respectively) with perfect intra- and inter-rater reliabilities for RUST (ICC: 0.92 and 0.90, respectively) and mRUST (ICC: 0.88 and 0.83, respectively) in pediatric patients and substantial intra- and inter-rater reliabilities in adult patients (ICC: 0.80 and 0.76, respectively, for mRUST, and 0.76 and 0.71, respectively, for RUST). At each time point, the mean mRUST and RUST scores were higher for pediatric fractures (p<0.001). The Fleiss k coefficient for union decision was perfect for pediatric fractures (0.88) and substantial for adult fractures (0.79). The total mRUST score had a higher predictive value of union than the total RUST score (area under the curve: 0.984 vs. 0.922 in adult fractures and 0.990 vs. 0.943 in pediatric fractures). A RUST score of ≥10 and mRUST score of ≥12 were excellent predictors of fracture union.

CONCLUSION

Fracture union of simple two-part pediatric and adult femoral shaft fractures treated with intramedullary fixation can be reliably assessed using the RUST and mRUST scores. The diagnostic value of the mRUST score is more evident in adult fractures.

LEVEL OF EVIDENCE

Level II, Diagnostic Study.

Early systemic immune biomarkers predict bone regeneration after trauma

Severe traumatic injuries are a widespread and challenging clinical problem, and yet the factors that drive successful healing and restoration of function are still not well understood. One recently identified risk factor for poor healing outcomes is a dysregulated immune response following injury. In a preclinical model of orthopedic trauma, we demonstrate that distinct systemic immune profiles are correlated with impaired bone regeneration. Most notably, elevated blood levels of myeloid-derived suppressor cells (MDSCs) and the immunosuppressive cytokine interleukin-10 (IL-10) are negatively correlated with functional bone regeneration as early as 1 wk posttreatment. Nonlinear multivariate regression also implicated these two factors as the most influential in predictive computational models. These results support a significant relationship between early systemic immune responses to trauma and subsequent local bone regeneration and indicate that elevated circulating levels of MDSCs and IL-10 may be predictive of poor functional healing outcomes and represent novel targets for immunotherapeutic intervention.

A quantitative and non-invasive vibrational method to assess bone fracture healing: a clinical case study

Orthopaedics needs a robust diagnostic tool that can help or even replace traditional radiography in bone healing assessment, thus reducing patient exposure to ionizing radiation. We used a vibrational method to assess the healing of a complex fracture treated with external fixation, exploiting a quantitative and non-invasive procedure. Callus stiffening was monitored from the time of surgery until the fixator was removed. Our approach overcomes previous limitations and involves a longer period of healing monitoring (about 9 months), very frequent tests (bi-weekly), and the analysis of a single test configuration. The healing process was monitored by analysing the percentage increments of the squared resonant frequencies (SFIs), related to the stiffness variation and the changes in the frequency response functions. The results were validated by X-rays images, and revealed that the most sensitive parameter to quantify the healing was the SFI of the first resonant frequency which increased by about 20% per month during the formation of the woven callus and up to about 50% at the end of healing completion. This study confirms the potential of the vibrational method as an alternative to radiography in fracture healing assessment.

Improvements in radiographic and clinical assessment of distal radius fracture healing by FE-estimated bone stiffness

Bone strength determined from finite element (FE) modelling provides an estimate of fracture healing progression following a distal radius fracture (DRF), but how these measures relate to patient-reported outcomes and functional outcomes remains unknown. We hypothesized that changes in bone stiffness and bone mineral density measured using high-resolution peripheral quantitative computed tomography (HR-pQCT) are associated with clinically available measures of functional and patient-reported outcomes. We also aimed to identify which clinical outcome measures best predict fracture stiffness and could therefore be used to inform cast removal.

Participants (n = 30) with stable distal radius fractures were followed for two week intervals from the time of fracture until two months post-fracture, then at three months and six months post-fracture. At each follow-up, participants underwent clinical, radiographic, and functional assessments, as well as had their fractured wrist scanned using HR-pQCT. Recovery of bone stiffness during fracture healing was determined from micro-FE (μFE) models generated from HR-pQCT image data.

During the DRF healing process, significant longitudinal changes were found in μFE-estimated stiffness, patient-reported outcomes, grip strength, range of motion (ROM), tenderness, number of cortices healed based on radiographs, and fracture line visibility (p < 0.05); however, no significant change was detected in HR-pQCT based total bone mineral density. Patient-reported outcomes, such as the Patient-Rated Wrist Evaluation (PRWE) and the Quick Disability of the Arm, Shoulder and Hand (QuickDASH) questionnaire, correlated strongly with μFE-estimated stiffness (0.61 ≥ r_m ≥ 0.66). Based on μFE-estimated stiffness, PRWE and QuickDASH are the best predictors of stiffness recovery (p < 0.05) and may be used to guide duration of cast immobilization in the clinical setting.

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Recovery of fracture stiffness may inform time required for cast immobilization.

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Patient reported outcomes predict rate of fracture stiffness recovery.

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Radiographic outcomes correlate weakly with fracture stiffness.

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Patient reported outcomes may inform duration of cast immobilization.