Fracture nonunion in long bones: A literature review of risk factors and surgical management

Nonunion of conservatively treated humeral shaft fractures is not associated with anatomic location and fracture pattern

INTRODUCTION

Humeral shaft fractures make up 1-3% of all fractures and are most often treated nonoperatively; rates of union have been suggested to be greater than 85%. It has been postulated that proximal third fractures are more susceptible to nonunion development; however, current evidence is conflicting and presented in small cohorts. It is our hypothesis that anatomic site of fracture and fracture pattern are not associated with development of nonunion.

MATERIALS AND METHODS

In a retrospective cohort study, 147 consecutive patients treated nonoperatively for a humeral shaft fracture were assessed for development of nonunion during their treatment course. Their charts were reviewed for demographic and radiographic parameters such as age, sex, current tobacco use, diabetic comorbidity, fracture location, fracture pattern, AO/OTA classification, and need for intervention for nonunion.

RESULTS

One hundred and forty-seven patients with 147 nonoperatively treated humeral shaft fractures were eligible for this study and included: 39 distal, 65 middle, and 43 proximal third fractures. One hundred and twenty-six patients healed their fractures by a mean 16 ± 6.4 weeks. Of the 21 patients who developed a nonunion, two were of the distal third, 10 of the middle third, and nine were of the proximal third. In a binomial logistic regression analysis, there were no differences in age, sex, tobacco use, diabetic comorbidity, fracture pattern, anatomic location, and OTA fracture classification between patients in the union and nonunion cohorts.

CONCLUSIONS

Fracture pattern and anatomic location of nonoperatively treated humeral shaft fractures were not related to development of fracture nonunion.

Biophysical Enhancement in Fracture Healing: A Review of the Literature

Bone healing constitutes a complex process involving cellular and pathophysiological mechanisms. Despite progress in osteosynthesis techniques, fracture union continues to be challenging. In some cases, it is not ultimately achieved or is delayed relative to the expected time resulting in economic and social outcomes for the patient and the health system. In addition to surgical treatment, biophysical methods have been developed to assist in fracture healing used in combination or individually. Biophysical stimulation is a non-invasive therapy used in orthopedic practice to increase and enhance tissue's reparative and anabolic activities. This study reviewed the existing literature, including electromagnetic fields, ultrasound, laser, extracorporeal shockwave therapy, and electrical stimulation, and revealed the efficacy of biophysical stimulation for bone healing. This study aims to define if these methods are helpful, especially in cases of non-union. Biophysical stimulation requires care and precision in use to ensure the success expected of it by physicians and patients.

Consistent Protocol-Based Management of Humerus Shaft Nonunion: An Analysis of 100 Cases

Introduction

Humerus shaft nonunions are very disabling and challenging to treat. The current study aims to analyse the rate of union and the incidence of complications following a consistent protocol in treating humerus shaft nonunion.

Methodology

We did a retrospective analysis of 100 patients with humerus shaft nonunion treated over an eight-year period from 2014 to 2021. The mean age was 42 years (range 18-75 years). There were 53 male and 47 female patients. The average time interval from injury to nonunion surgery was 23 months (range 3 months to 23 years). The series included 12 recalcitrant nonunions and 12 patients with septic nonunion. All patients underwent freshening of fracture edges to increase the contact surface area, stable fixation with a locking plate and intramedullary iliac crest bone grafting. Infective nonunions were treated in a staged manner, following a similar treatment protocol after the elimination of infection in the first stage.

Results

Complete union was achieved in 97% of the patients with a single procedure. One patient achieved union after an additional procedure, while two patients were lost to further follow-up. The mean time to union was 5.7 months (range 3-10 months). Three patients (3%) had postoperative radial nerve palsy, which recovered completely within 6 months. Three patients (3%) had a superficial surgical site infection, while one patient (1%) developed a deep infection.

Conclusion

Intramedullary cancellous autologous grafts combined with stable fixation by compression plating achieve a high union rate with minimal complications.

Level of Evidence

III.

Level of Clinical Care

Level I Tertiary trauma centre.

Comparative study on the effectiveness of bone grafting for arthrodesis of the thumb carpometacarpal arthritis

The aim of this retrospective study was to assess the effectiveness of autogenous bone grafting for arthrodesis of the thumb carpometacarpal joint by comparing the bone union rates with and without bone grafting. We included 36 patients who underwent arthrodesis of the thumb carpometacarpal joint for arthritis (20 patients with bone grafts and 16 without bone grafts). Implants used for internal fixation were K-wire, tension band wiring, headless compression screw and locking plate. The presence of bone union and the time from surgery to bone union were evaluated. The bone union rate was 20/20 (100%) in the bone grafting group and 12/16 (75%) in the non-bone grafting group (p = 0.03). There were no significant differences between the two groups in the time from surgery to bone union and patient characteristics. In conclusion, autogenous bone grafting may contribute to the bone union in the arthrodesis of thumb carpometacarpal arthritis.Level of evidence: III.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Nail breakage in patients with hypertrophic pseudoarthrosis after subtrochanteric femur fracture: treatment with exchanging nail and decortication

In this study, we aimed to show the results of exchange nail and decortication in patients whose subtrochanteric femur fractures were treated with intramedullary nails and subsequently developed fracture nonunion and nail breakage com- plications. This study consisted of patients presenting with subtrochanteric femur fractures between January 2013 and April 2019 who underwent surgery and later experienced nail breakage due to hypertrophic nonunion. There were a total of 10 patients aged 26-62 years (Avg 40,30, SD: 9,989). Nine patients were smokers, and 1 patient had diabetes and hypertension. Three patients were admitted to the trauma center due to a car accident and 7 patients were admitted because of a fall. The infection parameters of all patients were normal. All patients had pathological movement complications and pain at the fracture site. Preoperatively, medulla diameter was measured with standard radiography in all patients. The diameters of the old nails applied to the patients ranged from 10 to 12 mm, and the diameters of the newly applied nails ranged from 14 to 16 mm. The fracture lines of all patients were opened to remove the broken nails, and decortication was performed. No additional autograft or allograft was applied to any patient. Union was achieved in all patients. We conclude that the use of larger diameter nails in conjunction with decortication will prevent nail breakage, improve healing and provide early union in patients with subtrochanteric femur fractures with hypertrophic pseudoarthrosis.

Multifunctional Three-Dimensional Printed Copper Loaded Calcium Phosphate Scaffolds for Bone Regeneration

Bone regeneration using inorganic nanoparticles is a robust and safe approach. In this paper, copper nanoparticles (Cu NPs) loaded with calcium phosphate scaffolds were studied for their bone regeneration potential in vitro. The pneumatic extrusion method of 3D printing was employed to prepare calcium phosphate cement (CPC) and copper loaded CPC scaffolds with varying wt% of copper nanoparticles. A new aliphatic compound Kollisolv MCT 70 was used to ensure the uniform mixing of copper nanoparticles with CPC matrix. The printed scaffolds were studied for physico-chemical characterization for surface morphology, pore size, wettability, XRD, and FTIR. The copper ion release was studied in phosphate buffer saline at pH 7.4. The in vitro cell culture studies for the scaffolds were performed using human mesenchymal stem cells (hMSCs). The cell proliferation study in CPC-Cu scaffolds showed significant cell growth compared to CPC. The CPC-Cu scaffolds showed improved alkaline phosphatase activity and angiogenic potential compared to CPC. The CPC-Cu scaffolds showed significant concentration dependent antibacterial activity in Staphylococcus aureus. Overall, the CPC scaffolds loaded with 1 wt% Cu NPs showed improved activity compared to other CPC-Cu and CPC scaffolds. The results showed that copper has improved the osteogenic, angiogenic and antibacterial properties of CPC scaffolds, facilitating better bone regeneration in vitro.

Traumatic Humeral Shaft Non-union With Ulnar Nerve Transection: An Orthobiologics Success Story

Long bone non-union is a detrimental, yet common condition that affects many individuals after injury. It can lead to significant pain and weakness that may impact lifetime productivity and quality of life. This report describes a patient who suffered from greater than two years of a distal humerus fracture non-union along with an ulnar nerve transection that failed traditional surgical management and underwent a percutaneous injection with bone marrow aspirate concentrate, platelet-rich plasma, and platelet lysate, demonstrating subsequent fracture resolution and strength improvement.

A comparison of exchange nailing and plate augmentation over a retained intramedullary nail in aseptic oligotrophic and atrophic femoral shaft pseudoarthrosis

OBJECTIVES

This study aims to evaluate the success of plate augmentation over a retained intramedullary nail (IMN) against exchange nailing performed with autologous bone grafting in oligotrophic and atrophic pseudoarthrosis of the femoral shaft.

PATIENTS AND METHODS

Between May 2005 and October 2020, a total of 42 of 56 patients (28 males, 14 females; mean age: 47.3±17.2 years; range, 19 to 84 years) with aseptic atrophic or oligotrophic femoral nonunion were retrospectively analyzed. The patients, 20 were operated with plate over a retained IMN, and the rest (n=22) by exchange nailing. Data including demographic and clinical characteristics of the patients, treatment success, duration of surgery, blood loss during surgery, infection rates, length of hospital stay, time to bridging of the nonunion site, and time to obliteration of the fracture line (solid union) were recorded.

RESULTS

The mean follow-up was 23.8±20.4 (range, 12 to 96) months in the plate over an IMN group and 34.7±27.4 (range, 12 to 90) months in the exchange nailing group. At the final follow-up, solid union occurred in all of the patients in the plate augmentation over a retained IMN group, and 21 of 22 (95.45%) patients in the exchange nailing group. Blood loss during surgery was significantly less in the plate augmentation over IMN group (p=0.027). There was no statistically significant difference in the other variables between the two groups (p>0.05).

CONCLUSION

Our study results demonstrate that plate over a retained IMN is effective as exchange nailing in the surgical treatment of oligotrophic and atrophic pseudoarthrosis of the femoral shaft. However, it can be speculated that plate application over IMN is more advantageous in terms of blood loss during surgery.

Long Non-Coding RNAs Within Macrophage-Derived Exosomes Promote BMSC Osteogenesis in a Bone Fracture Rat Model

Purpose

To investigate the effect of macrophage exosomal long non-coding (lnc)RNAs on bone mesenchymal stem cell (BMSC) osteogenesis and the associated mechanism.

Methods

Rat BMSCs and spleen macrophages were co-cultured with serum derived from the fracture microenvironment of rat tibia. BMSC osteogenesis was evaluated using Alizarin red staining and the expression of BMP-2, RUNX2, OPN, and OC mRNA. BMSC osteogenesis was evaluated after co-culture with macrophages stimulated using hypoxic conditions or colony-stimulating factor (CSF). The uptake of macrophage-derived exosomes by BMSCs was evaluated using the exosome uptake assay. High-throughput sequencing and bioinformatics analyses were performed to identify key lncRNAs in the macrophage exosomes. The effect of lncRNA expression levels on BMSC osteogenesis was also assessed using a lncRNA overexpression plasmid and siRNA technology. M1 and M2 macrophages were distinguished using flow cytometry and the key exosomal lncRNA was detected by in situ hybridization.

Results

In the fracture microenvironment, macrophages (stimulated using either hypoxia or CSF) significantly increased the osteogenic ability of BMSCs. We showed that BMSCs assimilated macrophage-derived vesicles and that the inhibition of exosomal secretion significantly attenuated the macrophage-mediated induction of BMSC osteogenesis. The hypoxia condition led to the up-regulation of 310 lncRNAs and the down-regulation of 575 lncRNAs in macrophage exosomes, while CSF stimulation caused the up-regulation of 557 lncRNAs and the down-regulation of 407 lncRNAs. In total, 108 lncRNAs were co-up-regulated and 326 lncRNAs were co-down-regulated under both conditions. We eventually identified LOC103691165 as a key lncRNA that promoted BMSC osteogenesis and was expressed at similar levels in both M1 and M2 macrophages.

Conclusion

In the fracture microenvironment, M1 and M2 macrophages promoted BMSC osteogenesis by secreting exosomes containing LOC103691165.

Proximal ulna non-union: treatment concept and postoperative outcome

PURPOSE

Non-union of the proximal ulna is a serious complication after surgical treatment of olecranon and complex elbow fractures, frequently leading to poor functional outcome. To date, there is a lack of data regarding optimal treatment strategies and functional outcome parameters after surgical revision.

METHODS

From 02/2010 to 12/2018, 31 patients undergoing surgical treatment of proximal ulna non-union could be included. Follow-up period was seven years (SD 2.5 years). All patients were clinically assessed using a clinical assessment tool set and standard elbow scores (MEPS, OES, DASH score). All complications and unplanned revision surgeries were recorded and all radiographic material was analyzed.

RESULTS

Initial non-union procedures were performed at an average of 6.6 months (SD 3 months) after the index procedures. Those included the use of autologous spongiosa graft in all patients and concomitant compression re-osteosynthesis in 28 patients. Radiological consolidation was achieved in all patients. Overall, patients achieved a good to fair functional outcome with Mayo elbow performance score measuring 78.5 (SD 9.1), DASH score 34.7 (SD 14.4), and Oxford elbow score 31.2 (SD 6.6) points. Initial malreduction/implant-malposition could be identified as a main reason for the occurrence of the non-union. Furthermore, inferior postoperative outcome was detected in patients > 60 years and BMI > 30 kg/m².

CONCLUSION

Using a standardized protocol, bony union and acceptable functional outcomes can be achieved in proximal ulna non-unions. However, surgeons should be aware of potential risk factors and proper initial fracture reduction as key to achieve sufficient bone healing.

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

BACKGROUND

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Comparison of the clinical outcomes between vascularized bone graft and the Masquelet technique for the reconstruction of Gustilo type III open tibial fractures

BACKGROUND

Gustilo type III tibial fractures commonly involve extensive soft tissue and bony defects, requiring complex reconstructive operations. Although several methods have been proposed, no research has elucidated the efficacies and differences between vascular bone graft (VBG) and the Masquelet technique (MT) to date. We aimed to evaluate and compare the clinical effectiveness of VBG and the MT for the reconstruction of Gustilo type III tibial fractures.

METHODS

This retrospective cohort study enrolled patients who underwent reconstruction for Gustilo type III tibial fractures using VBG or the MT in a single center from January 2000 to December 2020. The patients' demographics, injury characteristics, and surgical interventions were documented for analysis. The clinical outcomes including union status, time to union, postoperative infections, and the causes of union failure were compared between the two groups.

RESULTS

We enrolled 44 patients: 27 patients underwent VBG, and 17 underwent MT. The average union time was 20.5 ± 15.4 and 15.1 ± 9.0 months in the VBG and MT groups, respectively (p = 0.232). The postoperative deep infection rates were 70.4% and 47.1% in the VBG and MT groups (p = 0.122), respectively. Though not statistically significant, the VBG group had a shorter union time than did the MT group when the bone defect length was > 60 mm (21.0 ± 17.0 versus 23.8 ± 9.4 months, p = 0.729), while the MT group had a shorter union time than did the VBG group when the bone defect was length < 60 mm (17.2 ± 5.6 versus 10.7 ± 4.7 months, p = 0.067).

CONCLUSIONS

VBG and MT are both promising reconstruction methods for Gustilo type III tibial fractures. VBG appears to have more potential in reconstructing larger bone defects, while MT may play an important role in smaller bone defects, severe surgical site infections, and osteomyelitis. Therefore, flexible treatment strategies are required for good outcomes in Gustilo type III open tibial fractures.

Bioresorbable Chitosan-Based Bone Regeneration Scaffold Using Various Bioceramics and the Alteration of Photoinitiator Concentration in an Extended UV Photocrosslinking Reaction

Bone tissue engineering (BTE) is an ongoing field of research based on clinical needs to treat delayed and non-union long bone fractures. An ideal tissue engineering scaffold should have a biodegradability property matching the rate of new bone turnover, be non-toxic, have good mechanical properties, and mimic the natural extracellular matrix to induce bone regeneration. In this study, biodegradable chitosan (CS) scaffolds were prepared with combinations of bioactive ceramics, namely hydroxyapatite (HAp), tricalcium phosphate-α (TCP- α), and fluorapatite (FAp), with a fixed concentration of benzophenone photoinitiator (50 µL of 0.1% (w/v)) and crosslinked using a UV curing system. The efficacy of the one-step crosslinking reaction was assessed using swelling and compression testing, SEM and FTIR analysis, and biodegradation studies in simulated body fluid. Results indicate that the scaffolds had comparable mechanical properties, which were: 13.69 ± 1.06 (CS/HAp), 12.82 ± 4.10 (CS/TCP-α), 13.87 ± 2.9 (CS/HAp/TCP-α), and 15.55 ± 0.56 (CS/FAp). Consequently, various benzophenone concentrations were added to CS/HAp formulations to determine their effect on the degradation rate. Based on the mechanical properties and degradation profile of CS/HAp, it was found that 5 µL of 0.1% (w/v) benzophenone resulted in the highest degradation rate at eight weeks (54.48% degraded), while maintaining compressive strength between (4.04 ± 1.49 to 10.17 ± 4.78 MPa) during degradation testing. These results indicate that incorporating bioceramics with a suitable photoinitiator concentration can tailor the biodegradability and load-bearing capacity of the scaffolds.

Subtrochanteric femoral fractures: A case series of 194 patients treated with long and short intramedullary nails

BACKGROUND

IM nails are the gold standard of subtrochanteric fractures management. Indications to use a short rather than a long nail remain unclear. Operative complications of subtrochanteric fractures reach up to 25%.

OBJECTIVE

Retrospectively compare clinical and radiographic outcome of subtrochanteric fractures treated by long and short intramedullary nailing, analysing rates of complications.

METHODS

390 patients were chosen from the archives. 194 patients were available: 70 treated with a short intramedullary nail (Group A), while 124 with long one (Group B). Radiographic evaluation at 6 and 12 months assess failure of the osteosynthesis. Clinical outcomes were the return to normal activities prior trauma and VAS scale. Group A mean age was 81.37 years, group B mean age was 78.9 years (29-99, SD: 15.38).

RESULTS

Radiografic Healing was found in 66 patients (94.28%) in group A, while in 116 patients (94.54%) in group B. Pseudarthrosis was found in 4 cases (5.71%) in group A, while in 8 cases (6.45%) in group B. Implant failure occurred in 5 cases: one required revision of fixation, while 4 require hip replacement. 59 patients of group A (84.29%) returned to social life, while 102 patients (81.94%) in group B. Group A mean VAS was 1.55, Group B mean VAS was 1.49.

CONCLUSION

Comparison of the two group showed no differences. Complication percentages are in line with literature. Optimal reduction and fixation allow high percentage of healing and return to social life.

Delayed union, non-union and mal-union in 442 dogs

OBJECTIVES

(1) To estimate the prevalence of delayed union, non-union and mal-union in canine fractures; (2) to describe fracture, demographic, and treatment characteristics for these outcomes; (3) to identify risk factors for delayed or non-union.

STUDY DESIGN

Retrospective study.

SAMPLE POPULATION

Four hundred and forty two dogs (461 fractures).

METHODS

A review was conducted of clinical records and radiographs from 2 teaching hospitals. "Union," "delayed union," "non-union" and "mal-union" were defined, and fracture, demographic, treatment, and outcome variables described. Differences in proportions or medians between "union," "delayed union" and "non-union" were tested using χ² and Mann-Whitney U-tests for categorical and continuous variables respectively. Potential explanatory variables for "delayed or non-union" were tested using logistic regression to identify risk factors.

RESULTS

Median radiographic follow up was 53 days (14-282). Delayed union occurred in 13.9% of fractures (64/461), non-union in 4.6% (21/461), and mal-union in 0.7% (3/461). Risk factors for delayed or non-union were age (OR 1.21, 95% CI 1.12-1.31); comminuted fracture (OR 4.24, 95% CI 2.4-7.5); treatment with bone graft (all types) (OR 3.32, 95% CI 1.3-8.5); surgical site infection (OR 3.24, 95% CI 1.17-8.97), and major implant failure (OR 12.94, 95% CI 5.06-33.1).

CONCLUSION

Older dogs, dogs with comminuted fractures, surgical site infection, or major implant failure were at increased odds of delayed or non-union. Radius and ulna fractures in toy breed dogs were not at increased odds of delayed or non-union.

CLINICAL SIGNIFICANCE

The identified risk factors should inform fracture planning and prognosticating. The prognosis for radial fractures in toy breeds appears better than historically believed.

Effects of electric charge on fracture healing

Fracture nonunion is a common and challenging complication. Although direct current stimulation has been suggested to promote fracture healing, differences in cell density near the positive and negative electrodes have been reported during direct current stimulation. This study aimed to explore the effects of these differences on osteoblast proliferation and fracture healing. MC3T3-E1 cells were stimulated by positive and negative charges to observe cell proliferation, apoptosis, and osteogenic factor expression in vitro, while positive and negative charges were connected to the Kirschner wires of the fractures in an in vivo double-toe fracture model in New Zealand white rabbits and fracture healing was assessed in digital radiography (DR) examinations performed on days 1, 15, 30. Bone tissue samples of all rabbits were analysed histologically after the last examination. The results showed that in comparison with the control group, after DC stimulation, the number of cells near the positive electrode decreased significantly (P < 0.05), apoptosis increased (P < 0.05), the expression of osteocalcin, osteoblast-specific genes, and osteonectin decreased significantly near the positive electrode (P < 0.05) and increased significantly at the negative electrode (P < 0.05). The fracture at the positive electrode junction of New Zealand white rabbits did not heal. Histomorphological analysis showed more bone trabeculae and calcified bone in the bone tissue sections of the control group and the negative electrode group than in the positive electrode group. The bone trabeculae were thick and showed good connections. However, positive charge inhibited osteoblast proliferation and a positive charge at fracture sites did not favour fracture healing. Thus, a positive charge near the fracture site may be a reason for fracture nonunion.

A novel bone graft technique combined with plating for aseptic recalcitrant long bone nonunion

Background

To evaluate the outcomes and efficacy of a new technique of autogenous iliac crest bone grafting combined with locking compression plate (LCP) vertical fixation for aseptic recalcitrant long bone nonunion.

Methods

From July 2010 to September 2020, 36 aseptic recalcitrant long bone nonunions were treated with a bone-forming channel technique and internal LCP fixation. All the patients had received one or more failed treatments. The injury mechanism, nonunion type and duration, and prior treatments were recorded pre-operation. The routine treatment process included nonunion area exposure, previous implant removal, sclerotic bone debridement, LCP fixation, bone-forming channel creation, and iliac bone grafting, and a second LCP fixation when required. At follow-up, X-ray images were obtained to assess bone healing and implant failure. Visual analog scale (VAS), fracture site stability, limb function, activity, muscle strength, limb length, and complications were recorded.

Results

A total of 34 patients (24 males and 10 females) were finally enrolled, with a mean age of 49.8 ± 12.3 years. At a mean follow-up of 35.6 ± 22.0 months, 32 patients displayed bone union, with a healing rate of 94.1% and mean union time of 6.8 ± 2.4 months. The VAS score was 0.7 ± 1 at the final follow-up. The functional results showed that 19 patients were excellent, 11 patients were good, 2 patients were poor, and 2 patients did not heal.

Conclusion

Bone-forming channel technique combined with LCP vertical fixation is an excellent option to treat recalcitrant long bone nonunion.

Level of evidence

Therapeutic Level IV.

Method for generating transparent porcine tibia showing the intraosseous artery

Background

The occurrence of nonunion after tibial fracture surgery is mainly related to insufficient blood supply. Therefore, anatomical study of the internal and external tibial artery is very important, but there is no good method for displaying the intraosseous artery clearly and intuitively. This hinders the protection and reconstruction of it by surgeons, as well as the development of new instruments and techniques by researchers.

Objective

To develop a transparent specimen that could clearly display the intraosseous artery of the tibia.

Methods

In 10 isolated pig calves with popliteal vessels, the popliteal artery was exposed and a tube was placed. A casting agent was then injected at constant pressure, and the tissue around the blood vessel was preliminarily removed after solidification. The perivascular tissue and periosteum were further removed via alkali corrosion, and the tibia was fixed with an external fixator to protect the non-corrosive areas at both ends. Alternate acid corrosion and flushing were then applied until the intraosseous artery was completely exposed. The distribution and branches of intraosseous nutrient arteries were observed with the naked eye and via microscopy. Three-dimensional (3D) scanning and 3D printing filling techniques were used to make transparent tibia specimens with preservation of intraosseous arteries.

Results

A cast specimen of the intraosseous artery of porcine tibia was successfully generated via epoxy resin perfusion combined with acid–alkali etching, and the intraosseous artery was clearly visible. The 3D printing and filling technique successfully produced a transparent tibia specimen with preservation of internal bone arteries, and accurately restored the external shape of the tibia. The foramen of the nutrient artery appeared near the middle upper third of the lateral edge of the tibia. After entering the tibia, the nutrient artery proceeded forward, medial, and downward for a certain distance, twisted and turned near the midpoint of the medullary cavity, and divided into the ascending and descending branches. After going in the opposite direction for a distance, the ascending trunk sent out 2–3 branches, and the descending trunk sent out 2–3 branches.

Conclusion

The cast specimen of pig intraosseous artery generated via the above-described perfusion corrosion method provides methodological guidance for the study of anatomical characteristics of the intraosseous artery, and a theoretical basis for the study of new methods of internal fixation and reconstruction of the blood supply of the lower tibia.

Comparison of outcomes and operative course between septic and aseptic nonunion in long bones

PURPOSE

The treatment of nonunion of long bones is difficult particularly in the presence of infection, which often involves staged surgical management. There is limited literature to compare the post operative course and outcomes of patients treated for septic versus aseptic nonunion. Thus, the purpose of this study was to determine if a difference exists between the number of surgical procedures, time to union, and rate of successful union for these two groups.

METHODS

A retrospective cohort study was performed at a single tertiary care center. Patients suffering nonunion of the humerus, tibia and femur were included. Patient demographic data and characteristics of the post operative course were collected to include number and reason for repeat operations, antibiotic course, time to union, and development of a successful union.

RESULTS

About 28 of 122 patients had septic nonunion. After diagnosis of nonunion, the septic group averaged 3.9 surgeries compared to 1.5 in the aseptic group (p < 0.001). There was no difference in the rate of successful union (79.8% versus 85.7%; p = 0.220), though the septic group took 129 days longer on average for successful union. (376 versus 247; p = 0.018).

CONCLUSION

Septic nonunion of long bones is associated with the need for significantly more operations as well as time to union, though union rates remain similar. The identification of infection is critical for both the appropriate treatment as well as counseling patients on the expected post operative course.

Outcomes after primary intramedullary nail fixation of open tibial and femoral fractures in low resource settings

INTRODUCTION

Open fractures are unique in the urgency they impart to the injury and the therapeutic challenge they pose. Non-union and infection are among the major concerns. Open tibial and femoral shaft fractures are among the commonest orthopaedic urgencies. Primary intramedullary (IM) nailing requires a skillset and knowledge of the principles of open fracture management and also a well-equipped operating room with the necessary implants and instruments. In a low resource setting, one or more of these prerequisites may not be met, and the outcome may thus be affected similarly. The objective of this study was to study these outcomes.

METHODS

We prospectively studied primary IM nailing of open 1, 2 and 3A tibial and femoral fractures done in our hospital, in a simple non-modular operating room without an image intensifier.

RESULTS

There were 106 fractures in 104 patients: 93 tibial and 13 femoral. The mean time from injury to surgical debridement was 19.6 h. Mean duration of antibiotics therapy was 4.3 days, and the mean duration of hospital stay was 4.1 days. All patients were followed up to union. Mean time to radiographic union was 6.1 months for the tibia and 5.7 months for the femur. Non-union was seen in 4 tibial and 1 femoral fractures. There were 3 superficial infections but no deep infection.

CONCLUSION

The outcomes were comparable to, and in some cases better than, those found in existing literature. We conclude that primary IM nailing in open long bone fractures can be performed in austere environments with good success, in expert hands if the principles are adhered to.

Concepts and clinical aspects of active implants for the treatment of bone fractures

Nonunion is a complication of long bone fractures that leads to disability, morbidity and high costs. Early detection is difficult and treatment through external stimulation and revision surgery is often a lengthy process. Therefore, alternative diagnostic and therapeutic options are currently being explored, including the use of external and internal sensors. Apart from monitoring fracture stiffness and displacement directly at the fracture site, it would be desirable if an implant could also vary its stiffness and apply an intervention to promote healing, if needed. This could be achieved either by a predetermined protocol, by remote control, or even by processing data and triggering the intervention itself (self-regulated 'intelligent' or 'smart' implant). So-called active or smart materials like shape memory alloys (SMA) have opened up opportunities to build active implants. For example, implants could stimulate fracture healing by active shortening and lengthening via SMA actuator wires; by emitting pulses, waves, or electromagnetic fields. However, it remains undefined which modes of application, forces, frequencies, force directions, time durations and periods, or other stimuli such implants should ideally deliver for the best result. The present paper reviews the literature on active implants and interventions for nonunion, discusses possible mechanisms of active implants and points out where further research and development are needed to build an active implant that applies the most ideal intervention. STATEMENT OF SIGNIFICANCE: Early detection of delays during fracture healing and timely intervention are difficult due to limitations of the current diagnostic strategies. New diagnostic options are under evaluation, including the use of external and internal sensors. In addition, it would be desirable if an implant could actively facilitate healing ('Intelligent' or 'smart' implant). Implants could stimulate fracture healing via active shortening and lengthening; by emitting pulses, waves, or electromagnetic fields. No such implants exist to date, but new composite materials and alloys have opened up opportunities to build such active implants, and several groups across the globe are currently working on their development. The present paper is the first review on this topic to date.

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

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

Perioperative Radiographic Predictors of Non-Union in Infra-Isthmal Femoral Shaft Fractures after Antegrade Intramedullary Nailing: A Case-Control Study

Antegrade intramedullary (IM) nailing is the gold standard treatment for femoral shaft fractures; however, the non-union rate of infra-isthmal femoral shaft fractures is still high after antegrade IM nailing. This retrospective case−control study aimed to determine the association between perioperative radiographic factors and the non-union of infra-isthmal femoral shaft fractures after antegrade IM nailing. Univariate and multivariate analyses were used to evaluate the radiographic risk factors of non-union. Ninety-three patients were included, with thirty-one non-unions and sixty-two matched controls between 2007 and 2017. All were regularly followed up for 2 years. Receiver operating characteristic analysis revealed that a ratio of the unfixed distal segment > 32.5% was strongly predictive of postoperative non-union. The risk factors for non-union were AO/OTA type B and C (odds ratio [OR]: 2.20), a smaller ratio of the distal fragment (OR: 4.05), a greater ratio of the unfixed distal segment (OR: 7.16), a higher ratio of IM canal diameter to nail size at the level of fracture (OR: 6.23), and fewer distal locking screws (OR: 2.31). The radiographic risk factors for non-union after antegrade IM nailing for infra-isthmal femoral shaft fractures were unstable fractures, shorter distal fragments, longer unfixed distal fragments, wider IM canal, and fewer distal locking screws. Surgeons must strive to avoid non-union with longer and larger nails and apply more distal locking screws, especially for unstable, wider IM canal, and shorter distal fragment fractures.

Bone Engineering Scaffolds With Exosomes: A Promising Strategy for Bone Defects Repair

The treatment of bone defects is still an intractable clinical problem, despite the fact that numerous treatments are currently available. In recent decades, bone engineering scaffolds have become a promising tool to fill in the defect sites and remedy the deficiencies of bone grafts. By virtue of bone formation, vascular growth, and inflammation modulation, the combination of bone engineering scaffolds with cell-based and cell-free therapy is widely used in bone defect repair. As a key element of cell-free therapy, exosomes with bioactive molecules overcome the deficiencies of cell-based therapy and promote bone tissue regeneration via the potential of osteogenesis, angiogenesis, and inflammation modulation. Hence, this review aimed at overviewing the bone defect microenvironment and healing mechanism, summarizing current advances in bone engineering scaffolds and exosomes in bone defects to probe for future applications.

Prior use of antibiotics and immunosuppression are risk factors for fracture-related infection during the COVID-19 pandemic period: a Brazilian prospective cohort study

Background

Little is known about the role of COVID-19 pandemic period on the epidemiology of fracture-related infection (FRI). The present study summarizes the changes in the prevalence, microbiology, and risk factors of FRI during this period.

Methods

A prospective single-center cohort study assessed in the setting of COVID-19 pandemic (2020–2021), clinical, microbiological aspects, and independent risk factors (RF) of FRI. RFs were estimated by bivariate and multivariable analyses using prevalence ratio (PR) with significance at P < 0.05. Kaplan–Meier analysis was performed to evaluate treatment outcomes.

Results

Overall, 132 patients were analyzed, with patients with age over 65 years accounting 65.1%. FRI was diagnosed in 21(15.9%) patients. Independent RFs for FRI were recent and preoperative use of systemic antibiotics (PR: 7.0, 95% confidence interval (95% CI): 2.2 – 22.4, p = 0.001) and cancer (PR: 9.8, 95% CI: 2.0 – 48.8, p = 0.005). Cultures yielded Gram-negative bacteria in 77.8%, 33.3% were MDR.

Conclusions

We found higher rates of FRI, predominating in the elderly with closed femoral fractures during the COVID-19 pandemic. Prior use of antibiotics and immunosuppression conditions were independent factor for FRI. Our outcomes provide evidence to avoid the empirical use of antibiotics prior to surgery for fracture stabilization.

Alcohol-induced inhibition of bone formation and neovascularization contributes to the failure of fracture healing via the miR-19a-3p/FOXF2 axis

Aims

Alcoholism is a well-known detrimental factor in fracture healing. However, the underlying mechanism of alcohol-inhibited fracture healing remains poorly understood.

Methods

MicroRNA (miR) sequencing was performed on bone mesenchymal stem cells (BMSCs). The effects of alcohol and miR-19a-3p on vascularization and osteogenic differentiation were analyzed in vitro using BMSCs and human umbilical vein endothelial cells (HUVECs). An in vivo alcohol-fed mouse model of femur fracture healing was also established, and radiological and histomorphometric analyses were used to evaluate the role of miR-19a-3p. The binding of miR-19a-3p to forkhead box F2 (FOXF2) was analyzed using a luciferase reporter assay.

Results

miR-19a-3p was identified as one of the key regulators in the osteogenic differentiation of BMSCs, and was found to be downregulated in the alcohol-fed mouse model of fracture healing. In vitro, miR-19a-3p expression was downregulated after ethanol administration in both BMSCs and HUVECs. Vascularization and osteogenic differentiation were independently suppressed by ethanol and reversed by miR-19a-3p. In addition, the luciferase reporter assay showed that FOXF2 is the direct binding target of miR-19a-3p. In vivo, miR-19a-3p agomir stimulated callus transformation and improved the alcohol-impaired fracture healing.

Conclusion

This study is the first to demonstrate that the miR-19a-3p/FOXF2 axis has a pivotal role in alcohol-impaired fracture healing, and may be a potential therapeutic target.

Cite this article: Bone Joint Res 2022;11(6):386–397.

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

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

Classification of Proximal Humerus Fractures According to Pattern Recognition is Associated with High Intraobserver and Interobserver Agreement

Background

The Mayo-Fundación Jiménez Díaz (FJD) classification for proximal humerus fractures aims to identify specific fracture patterns and apply displacement criteria to each pattern. The classification includes 7 common fracture patterns: isolated fractures of the greater or lesser tuberosity, fractures of the surgical neck, impacted fractures involving head rotation in a varus and posteromedial direction or in valgus, and fractures where the humeral head is dislocated (head dislocation), split (head splitting), or depressed (head impaction). The purpose of this study was to evaluate the intraobserver and interobserver agreement of the Mayo-FJD classification system using plain radiographs (xR) and computed tomography (CT).

Methods

Three fellowship-trained shoulder surgeons blindly and independently evaluated the xR and CT of 103 consecutive proximal humerus fractures treated at a Level I trauma center. Each surgeon classified all fractures according to the Mayo-FJD classification system on 4 separate sessions at least 6 weeks apart. K values were calculated for intraobserver and interobserver reliability.

Results

The average intraobserver agreement was 0.9 (almost perfect) for xR and 0.9 (almost perfect) for CT scans. The average interobserver agreement was 0.69 (substantial) for xR and 0.81 (almost perfect) for CT scans at the first round, and 0.66 (substantial) for xR and 0.75 (substantial) for CT scans at the second round.

Conclusion

The pattern-based Mayo-FJD classification scheme for proximal humerus fractures was associated with adequate intraobserver and interobserver agreement using both xR and CT scan. Interobserver agreement was best when fractures were classified using CT scans.

Evaluation of complications associated with bifocal bone transport as treatment for either proximal, intermediate or distal femoral defects caused by infection: outcome analysis of 76 patients

BACKGROUND

The purpose of this study was to evaluate the outcomes of bifocal bone transport in the treatment of femoral bone defects caused by infections.

METHODS

Clinical and radiographic data of patients with infected femoral nonunion treated by the bifocal bone transport at our hospital were analyzed retrospectively, from January 2008 to December 2019. Depending on the location of bone defects, the patients were divided into three groups (proximal, intermediate, and distal). The Association for the Study and Application of the Method of Ilizarov (ASAMI) criteria was applied to assess the bone and functional outcomes. Postoperative complications of three groups were documented and compared.

RESULTS

Seventy-six cases of infected femoral bone defects (31 cases of proximal, 19 cases of intermediate, and 26 cases of distal) were managed by bifocal bone transport successfully with a mean follow-up time of 30.8 months (range, 23 to 41 months). There were 58 men (76.3%) and 18 women (23.6%), with a mean age of 38.8 years (range, 23 to 60 years). The bone union was received in 76 cases with a mean of 6.9 months (range, 5 to 8 months). Pin tract infection was observed in twenty-nine cases (38.1%), 7 cases (9.2%) of muscle contractures, 3 cases (7.9%) of joint stiffness, 13 cases (17.1%) of axial deviation, 2 cases (2.6%) of delayed union, one case (1.3%) of nonunion, and none (0%) of transport gap re-fracture. One patient (1.3%) was scheduled for knee arthroplasty when bone transport treatment ended.

CONCLUSIONS

Bone transport using an external rail fixator was a practical method to treat the femoral bone defects, since the satisfactory rate of bone union and limb function recovery. Complications of distal femoral bone transport were more severe than the proximal and intermedia, but the rate of complication was the least of the three groups. Soft-tissue-related complications were more likely to occur in the intermediate bone transport.

Obesity Increases Time to Union in Surgically Treated Pediatric Fracture Patients

Introduction:

To determine whether obesity affects time to radiographic union in surgically treated pediatric extremity fractures.

Methods:

A retrospective review of pediatric patients with extremity fractures at a Level 1 trauma center from 2010 to 2020. Those treated conservatively and patients with nonunions were excluded. Union was defined as radiographic evidence of bridging callus on all sides of the fracture and absence of the previous fracture line.

Results:

Obese patients had a markedly increased time to union when compared with others, even when age, sex, fracture type, race, and ethnicity were controlled for. The mean time to union for obese and nonobese patients were 152 and 93.59 days, respectively (P < 0.001). Obese patients had 3.39 times increased odds of having increased time to union. Obese patients had 6.64 times increased odds of having fractures with delayed union of 4 months or greater (P < 0.001).

Conclusions:

There is a positive correlation between obesity and time to union in surgically treated pediatric fracture patients.

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

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

Delayed Tibial Shaft Fracture Healing Associated with Smoking: A Systematic Review and Meta-Analysis of Observational Studies Conducted Worldwide

Tibial fractures represent a great burden of disease globally, being the most common long-bone fracture; smoking is a known risk factor for delayed skeletal healing and post-fracture complications. This systematic review and meta-analysis aims to analyse the effect of smoking on healing of tibial shaft fractures. PubMed, CINAHL, EMBASE, and Cochrane Library databases were searched from inception to March 2021, with no limitation on language, to find relevant research. All observational studies that assessed the association between cigarette smoking and tibial shaft fracture healing in adults (≥18 years) were included. The quality of studies was evaluated using the Newcastle Ottawa Quality Assessment Scale. A random effects model was used to conduct meta-analysis. Tobacco smoking was associated with an increased rate of non-union and delayed union as well as an increase in time to union in fractures of the tibial shaft. Among the 12 included studies, eight reported an increased rate of non-union, three reported delayed union, and five reported an increase in time to union. However, the results were statistically significant in only three studies for non-union, one for delayed union, and two studies for increased time to union. This review confirms the detrimental impact of smoking on tibial shaft fracture healing and highlights the importance of patient education regarding smoking cessation.

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.