Reamed intramedullary exchange nailing in the operative treatment of aseptic tibial shaft nonunion

Mechanical comparison of straight and pre-bent interlocking nails used for the stabilization of a tibial gap fracture model

OBJECTIVE

To compare the mechanical behavior of straight (STRT) and pre-bent (BENT) I-Loc angle-stable interlocking nails (AS-ILN) used for stabilization of canine mid-diaphyseal tibial fractures.

STUDY DESIGN

In vitro experimental study.

SAMPLE POPULATION

Tibial gap fracture models (n = 5/group).

METHODS

Tibial models simulating a comminuted mid-diaphyseal fracture were stabilized with either a STRT or BENT I-Loc AS-ILN. Bent nails were contoured to match the 10° tibial recurvatum of a mid-size dog. Constructs were subjected to cyclic eccentric compressive loads followed by ramp load until failure. Construct compliance, maximum compressive load and resistive torque, yield load and angular deformation at 450 N were statistically compared using t-tests (p < .05). Failure modes were described.

RESULTS

Compliance was 45% lower in BENT than STRT groups (p < .0001). Constructs in the BENT group sustained ~20% and 34% greater maximum and yield loads, respectively, than STRT constructs. Maximum resistive torques were similar between groups (p = .16). At 450 N, sagittal plane angular deformation increased from 0° to 4° in procurvatum (STRT group) and decreased from 10° to 8° in recurvatum (BENT group-p < .0001). Construct yield failure occurred at the nail isthmus in both groups.

CONCLUSION

These results demonstrated that, in a tibial gap fracture model, pre-bending I-Loc AS-ILNs provided mechanical advantages by increasing their ability to resist bending resulting from eccentric compressive loads.

CLINICAL SIGNIFICANCE

Pre-bending may reduce the occurrence of tibial nail yield failure. Surgeons should therefore consider pre-bending tibial I-Loc nails to match the bone anatomical recurvatum prior to implantation.

Modified Radiological Union Score of Tibia (RUST) Scores in Diaphyseal Fractures Treated by the Ilizarov Frame: A Retrospective Analysis Evaluating Reliability

Introduction The number of cases of tibia diaphyseal fractures treated by Ilizarov fixation is increasing. Fractures with infective etiology and altered bone biology due to the requirement of revision surgery or open wounds, which are often treated by the Ilizarov method, have challenges in ascertaining radiological signs of union. In this study, we aim to demonstrate the application of the modified Radiological Union Score of Tibia (m-RUST) scores in the assessment of fracture union in patients operated by the Ilizarov method. The secondary aim is to assess the interobserver and intraobserver variability of the m-RUST score validated by orthopaedicians and radiologists. Methodology A total of 119 patients who were treated with an Ilizarov fixator from February 2017 to December 2023 were included in the study. Four observers (two orthopaedicians and two radiologists) independently applied the m-RUST score for the included patients. Clinical data were not disclosed to the observers who worked independently of each other. Intraclass correlation coefficients (ICC) with 95% confidence intervals (CI) were used to measure the reliability of the m-RUST score. Interobserver reliability was measured by examining the scores of four observers from the second assessment, and intra-observer variability was assessed by a repeat evaluation after two weeks following the first assessment. Results The m-RUST score of the 119 X-rays analysed ranged from 8 to 16. The mean score in the first assessment was 11.36±3.51, and in the second assessment was 11.42±3.39. The reliability between all the observers was "substantial agreement" (ICC: 0.74, 95% CI). The ICC among the orthopaedicians was 0.77 and that among the radiologists was 0.72. Conclusion The m-RUST score has potential in other long bone fractures such as femur or humerus. Assessment of the m-RUST score in the healing of infective sequel and bone grafting conditions has been found effective. The m-RUST score is a dependable score in evaluating union in tibia fractures treated by the Ilizarov frame.

Callus formation and bone remodeling in a tibial nonunion after minimal invasive percutaneous screw fixation followed by extracorporeal shockwave therapy 17-months after initial trauma - A case report

INTRODUCTION

The treatment of tibial nonunion is challenging and treatment may be conservative or surgical. Conservative strategies include functional braces and weight bearing, or focused extracorporeal shockwave therapy (fESWT).

CASE DESCRIPTION

A 45-year-old male patient sustained spiral tibial shaft fractures and was treated surgically within 24 hours after the initial accident with intramedullary nails. The tibial fracture was later classified as nonunion after 11 months. Radiologic evaluation 17 months after the initial trauma demonstrated clinical nonunion, and subsequently the patient was offered a conservative approach with fESWT to facilitate an increase in callus formation. The handpiece was fitted with a stand-off II (long), penetration depth of 15 mm. Three cycles were administered in month 17, 19 and 20 after baseline. Each cycle consisted of three treatments sessions spaced with 6-8 days apart, and consisted of 3000 to 4000 impulses each given at 0.25-0.84 mJ/mm2. The number of impulses and the power at the focus point varied according to the pain response.

OUTCOMES

The patient achieved union 23 months after fracture. A clinical important improvement was observed with both Lower Extremity Functional Scale (LEFS) (18-point difference) and Patient Specific Functional Scale (PSFS) (average: 4.7 points,) The "worst pain last 24 hours" was reduced by 5 points. These values express minimal clinically important difference (MCID) values in these functional patient-reported outcome measures.

CONCLUSION

This treatment strategy may be viable in a broader setting, including private practice physiotherapy thereby treating the patient in close proximity to the patient's everyday life.

Augmentation plate without bone graft in the management of distal tibial diaphyseal non-union

PURPOSE

The objective of this study was to assess the efficacy of augmentation plating with retaining of previous implant in situ in cases of non-united oligotrophic or atrophic aseptic distal tibial diaphyseal and metaphyseal fractures without bone grafting depending on the unified bone healing and non-union theory.

METHODS

Through the period between December 2019 and December 2022, twelve patients with distal third tibial non-unions who were fixed at time of fracture either by intramedullary interlocking nails (seven cases) or by minimally invasive plate osteosynthesis (five cases) were included. Non-union was diagnosed on basis of absence of any healing progression in three months period or absence of fracture healing after six months from index surgery. All patients had oligotrophic or atrophic non-union. Augmentation plating through an anterolateral approach was done on average of 7.25 months after initial surgery (6-9 months). Circumferential exposure of the fracture site and debridement of fibrous tissue were not necessary. No bone grafting was done as no cases had major bone defect.

RESULTS

All patients achieved complete radiological union with a mean time of 21.8 weeks (range 18-30 weeks) that mean full callus formation in all cortices. All patients were walking independently after three months (13weeks) from surgery and returned to work even in cases of absent complete radiological union. No cases had been complicated with wound healing problems (infection or dehiscence). One patient had incomplete ankle dorsiflexion (10°) due to tight calf muscles and one patient had paresthesia on the dorsum of the foot that was not improved at last follow up (one year after surgery).

CONCLUSION

Augmentation plating is a safe and effective option for management of distal tibial diaphyseal nonunion even in cases of oligotrophic or atrophic non-union.

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.

[Infected nonunion: diagnostic and therapeutic work-up]

BACKGROUND

Septic nonunion is one of the major complications in fracture healing. The challenge is to identify the infection as the cause of nonunion first and then to achieve healing of the infection and the bone.

OBJECTIVE

Because of the more heterogeneous appearance of an infected nonunion, the prevalence of germ detection in surgical nonunion revision is often underestimated.

MATERIAL AND METHODS

In a retrospective study between 2010 and 2017, 86 patients with radiologically confirmed femoral shaft nonunion without clinical evidence and unremarkable medical history of a florid infection as the cause of nonunion, who had undergone primary single-stage surgical nonunion revision were analyzed. At least four intraoperatively obtained samples were evaluated for microbiological diagnosis. A distinction was made between tissue samples with subsequent 48‑h short-term incubation and tissue samples with 14-day long-term cultivation. The finding "germ detection" was made if at least two of the samples demonstrated bacterial growth.

RESULTS

In 18 of 86 patients with a nonunion preoperatively judged to be aseptic, positive bacterial evidence was obtained after short-term incubation. After long-term cultivation, positive bacterial detection was possible in 38 of 86 patients with a femoral shaft nonunion initially classified as aseptic. Regarding potential risk factors, the two groups demonstrated no relevant differences. In 29 patients, 1 pathogen was isolated from the obtained samples, whereas in the remaining 9 patients, a mixed culture with an average of 2.9 ± 0.5 different bacteria was detected. Identification revealed mainly low-virulence bacteria, most commonly Staphylococcus epidermidis.

CONCLUSION

If the preoperative diagnostics including clinical, laboratory and radiological examination as well as a careful anamnesis reveal indications of a possible infectious event, the surgical nonunion revision should be performed in two stages with specimen collection before definitive nonunion revision. For microbiological diagnosis, several representative tissue samples should independently be obtained from the nonunion site and incubated for 14 days. Only in the absence of evidence of septic nonunion is a single-stage procedure suggested.

The role of low-grade infection in the pathogenesis of apparently aseptic tibial shaft nonunion

PURPOSE

Aim of this study was to determine the rate of low-grade infection in patients with primarily as aseptic categorized tibial shaft nonunion and lack of clinical signs of infection.

METHODS

In a retrospective study between 2006 and 2013, all patients who underwent revision surgery for treatment of tibial shaft nonunion without clinical evidence of infection were assessed. Bacterial cultures harvested during nonunion revision, C-reactive protein (CRP) and/or white blood cell (WBC) values at hospital admission, outcome, and epidemiological data were analyzed.

RESULTS

In 88 patients with tibial shaft nonunion without any clinical signs of infection, bacterial samples remained negative in 51 patients. In 37 patients, microbiological diagnostic studies after long-term culturing demonstrated positive bacterial cultures whereas after short-term culturing for 2 days only 17 positive cultures were observed. In 12 cases a mixed culture with 2.3 different bacteria on average was detected. Among patients with negative bacterial cultures bone healing was achieved after 13.2 months. Nonunion with positive bacterial cultures required 19 (range 2-42) months until osseous healing (p = 0.009). Furthermore, nonunion with positive bacterial cultures require statistically more surgical revisions to achieve healing (2.9 ± 0.5 vs. 1.3 ± 0.1 additional procedure; (p = 0.003). Hematological studies carried out before surgical intervention did not demonstrate significant differences in CRP values (negative vs. positive cultures: 0.3 (range 0.3-2.8) mg/dl vs. 0.5 (range 0.3-5.7) mg/dl (p = 0.181) and in WBC values (negative vs. positive cultures: 7.4 (range 3.5-11.9) /nl vs. 7.3 (range 3.7-11.1) /nl (p = 0.723). Limitations of this study may include the varying amount of the at least four samples for microbiological diagnostics as well as the circumstance that for diagnosing low-grade infection swabs and tissue samples were included in this evaluation as being equivalent.

CONCLUSION

The pathogenesis of nonunion may originate from low-grade infection even in patients without clinical signs of infection. In addition, nonunion with positive bacterial cultures require statistically more surgical revisions to achieve healing. Therefore, during any revision surgery, multiple bacterial samples are intended to be harvested for long-term culturing. Particularly, in tibial shaft nonunion following Gustilo-Anderson type III open fractures, low-grade infection should be suspected.

TRIAL REGISTRATION NUMBER

DRKS00014657.

DATE OF REGISTRATION

04/26/2018 retrospectively registered.

Healing the Index Tibial Nonunion: Risk Factors for Development of a Recalcitrant Nonunion in 222 Patients

OBJECTIVES

To compare and stratify the healing rates after our index nonunion surgery using contemporary methods of fixation, report the prevalence of recalcitrant non-union, and identify specific demographic, injury, and treatment-related risk factors for the development of a recalcitrant nonunion.

DESIGN

Retrospective analysis of a prospectively collected database.

SETTING

Academic Level 1 Trauma Center.

PATIENTS/PARTICIPANTS

Two hundred twenty-two tibial nonunions treated with internal fixation by a single surgeon.

INTERVENTION

Bivariate and multivariate regression analysis were performed to compare healing rates by the type of fixation and graft augmentation and to identify specific demographic, injury, and treatment-related risk factors for the development of a recalcitrant nonunion.

RESULTS

Of the 222 patients, 162 (73%) healed as intended and 51 (23%) required 1 or more subsequent interventions to achieve union (96%). Nine fractures (4%) failed to unite. The 60 fractures (27%) that required a subsequent intervention(s) or failed to consolidate were defined as recalcitrant nonunions. There were no statistically significant differences in the recalcitrant rate when we compared plates versus nails or types of bone graft. Risk factors for developing a recalcitrant nonunion were multifactorial and included grade III open fractures, compartment syndrome, deep infection, and 2 or more prior surgical procedures.

CONCLUSIONS

Internal fixation remains a successful method of treatment for most tibial nonunions. However, 27% of patients required a subsequent intervention because of failure to heal our index nonunion procedure. Factors that are associated with recalcitrant nonunions were a grade III open fracture, compartment syndrome, deep infection, and 2 or more or more prior surgical procedures.

LEVEL OF EVIDENCE

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

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

Nonunion following a long bone fracture causes considerable morbidity when it occurs. Risk factors depend on specific fractures but there is a complex interplay of injury severity, comorbidities, patient medication and infection. The majority of nonunions occur after long bone fractures with the tibia, femur, forearm, humerus and clavicle predominating. Despite interest in the biological augmentation of fracture healing, the majority of nonunions can be effectively managed with conventional surgical techniques. In this review we present a review of risk factors for nonunion and the outcome following surgical management.

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

Objectives

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

Patients and methods

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

Results

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

Conclusion

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

Double plating with autogenous bone grafting as a salvage procedure for recalcitrant humeral shaft nonunion

Background

Although most cases of humeral shaft nonunion respond well to surgical intervention, surgeons still encounter patients with humeral shaft nonunion who have already undergone repeated surgeries for nonunion. This study retrospectively analyzed the efficacy of double locking compression plate (LCP) fixation in combination with autogenous iliac crest bone grafting for recalcitrant humeral shaft nonunion.

Methods

A consecutive series of patients with aseptic recalcitrant humeral shaft nonunion underwent surgical treatment between May 2010 and August 2017 in our institution. Standardized treatment included thorough debridement, double LCP and screw fixation, and autogenous iliac bone grafting. The injury type and the duration of nonunion were recorded for all patients. The main outcome measurements were the Constant and Murley scale for shoulder function, Mayo elbow performance index (MEPI) for elbow function, and visual analog scale (VAS) for pain. In addition, all complications were documented.

Results

The study cohort comprised six females and nine males with a mean age of 45.3 ± 13.1 years. Each patient had already undergone at least one failed surgery for humeral shaft nonunion. The average duration of nonunion before the index intervention was 126.8 ± 124.2 months. All patients achieved bone union without implant failure. At final follow-up, the mean Constant and Murley score and mean MEPI were significantly improved, and the mean VAS score was significantly decreased. Each patient was very satisfied with the treatment. Four patients had complications, including one with a superficial wound infection, one with radial nerve palsy, one with ulnar nerve palsy, and one with discomfort at the iliac crest.

Conclusion

Double plate fixation combined with autogenous iliac crest bone grafting results in successful salvage of humeral shaft nonunion after prior failed surgical interventions.

Variability of orthopedic physician fracture location identification: Implications for bone stimulator treatment

INTRODUCTION

Aseptic non-union is a significant complication in approximately 5% of long-bone fractures. External bone stimulation treatment is often attempted before more invasive surgical interventions. Bone stimulators can have favorable results, but have a limited 1.7cm therapeutic radius. This study evaluated the accuracy by which clinicians locate a fracture on a cadaveric model. This has implications for the clinician's ability to accurately counsel patients on daily bone stimulator placement. Additionally, physicians (orthopedic attending surgeons and residents) were compared with pre-clinical (M1 and M2) medical students to evaluate if higher levels of training improved accuracy.

HYPOTHESIS

Orthopedic physicians and pre-clinical medical students will localize a radiographic fracture within 1.7cm less than 100% of the time, which represents the ideal consistency for patient care. Furthermore, orthopedic physicians will achieve a higher percentage accuracy than pre-clinical medical students.

MATERIALS AND METHODS

The sample included 20 orthopedic physicians and 16 pre-clinical medical students. Upper (radius) and lower (tibia) extremity cadaver models were prepared by inducing a single, transverse diaphyseal fracture. Plain reference radiographs of each model were obtained. Participants placed a radiopaque marker onto each model at the perceived fracture location, and radiographs were taken to document placement. Perpendicular marker-to-fracture distance was measured to the nearest mm along each bone's long axis using the PACS system.

RESULTS

Placement within the therapeutic radius was achieved by 70-80% of physicians, and 69-75% of medical students. In the remaining participants, improper placement distances were lower among physicians than among medical students (radius: 2.1±0.5 vs. 3.6±0.9cm, p=0.02; tibia: 2.6±0.5 vs 3.5±0.5cm, p=0.89).

DISCUSSION

In two cadaveric fracture models, up to 30% of orthopedic surgeons perceived a fracture location to be outside a bone stimulator's 1.7cm therapeutic radius. This finding suggests that physicians and their patients may benefit from additional methods for specifying the location of a non-union before commencing daily bone stimulator treatment.

LEVEL OF EVIDENCE

Level IV, prospective cohort study-evidence from a well-designed prospective cohort study.

Reamed Exchange Nailing in Nonunion of Tibial Shaft Fractures: A Review of the Current Evidence

One of the most dreaded complications of fracture management is a nonunion. Nonunions are usually difficult to manage and can be a source of significant mental, physical, and financial distress to the patient. The incidence of nonunion is dependent on multiple factors including degree of comminution, open versus closed, concomitant infection, and vascular status, and therefore the management of such nonunions continues to be an often debated topic. Currently, there is no clear consensus on the role of reamed exchange nailing for tibial shaft nonunions. While reamed exchange nailing for aseptic tibial shaft nonunions has shown promising results, with very high union rates, many surgeons prefer newer novel techniques such as plating along with osteoperiosteal decortication or the use of more conventional compressive plating with bone grafts. The aim of this article is to critically review and understand the available evidence base on reamed exchange nailing in nonunion of tibial shaft fractures and to explore the other options available and their indications.

Surgical treatment outcomes of the Ilizarov and internal osteosynthesis methods in posttraumatic pseudarthrosis of the tibia-a retrospective comparative analysis

Introduction

This study compared surgical treatment outcomes of the Ilizarov and internal osteosynthesis methods in posttraumatic pseudarthrosis of the tibia.

Material and methods

In a retrospective comparative study, 75 patients were treated with the Ilizarov technique for aseptic posttraumatic pseudarthrosis of the tibia in the period 2000–2016. We compared them with the 51 patients from the control group, treated for tibial bone union disturbances using internal osteosynthesis methods, i.e., internal-fixation plates and intramedullary nails. The study groups were compared in terms of the rates of union, time to union, and the baseline-to-postoperative difference in lower leg deformity.

Results

Union rate in the Ilizarov group was 100% and the control group was 51.92% (p < 0.001). The median time to union suggests that patients from the Ilizarov group needed a shorter time to achieve bone union (203.00 days vs. 271.00 days) (p = 0.091). The effect size in the Ilizarov group was larger both in terms of reducing both limb deformity and shortening (it is worth noting, however, that the Ilizarov treatment was used in patients with higher baseline values of both these parameters). We observed no significant difference in terms of time to union between the group of patients with at least one risk factor for disturbance in fracture healing and the group with no risk factors. The following risk factors were considered: diabetes mellitus, corticosteroid therapy, smoking, alcohol dependence, and advanced lower-extremity vascular disease (p = 0.827).

Discussion

Our study demonstrated a high effectiveness of the Ilizarov method in the treatment of aseptic posttraumatic pseudarthroses of the tibia. The Ilizarov method seems to be worth considering in all cases where either the patient or the nature of injury is associated with additional risk factors and whenever there is a need for leg deformity correction or leg elongation.

[Evolution and principles of intramedullary locked nailing]

Key factors for successful osteosynthetic fracture stabilization are anatomical fracture reduction, restoration of axis and torsion alignment as well as tissue-preserving operative techniques. In long bone fractures, the use of intramedullary long bridging nailing offers ideal conditions for bone healing, as axial and rotational stability is provided by canal-filling nails and locking screws. In addition, the tissue in the fracture region is protected as the intramedullary nail insertion is distant from the fracture. The indication spectrum for modern intramedullary locked nailing includes diaphyseal fractures of long bones, metaphyseal fractures and reconstructions, as well as treatment of nonunion, osteotomy and arthrodesis of the lower extremities. Continuous improvements in nail design and instrumentation as well as the introduction of anatomical reconstruction nails will optimize the spectrum and effectiveness of intramedullary osteosynthesis even further.

Minimally Invasive Percutaneous Plate Osteosynthesis (MIPPO) Combined with Onionskin-Like Autologous Bone Grafting: A New Technique for Treatment of Tibial Nonunion

BACKGROUND Established tibial nonunions rarely heal without secondary intervention; revision surgery is the most common intervention. Herein, we evaluated the clinical outcomes of patients with tibial nonunion treated with a new technique - minimally invasive percutaneous plate osteosynthesis (MIPPO) - combined with a new onionskin-like autologous bone grafting method. MATERIAL AND METHODS From 2010 to 2013, 18 patients with tibial nonunions (average bone defect: 9.5 mm) were treated with MIPPO technology combined with onionskin-like autologous bone grafting. Indices for clinical evaluation included operative time, fluoroscopy time, blood loss, hospital stay, healing time, postoperative complaints, radiographic performances, the Short Musculoskeletal Function Assessment (SMFA) questionnaire, and the American Orthopedic Foot & Ankle Society (AOFAS) ankle-hindfoot score. RESULTS The average operation and fluoroscopy times for tibial nonunion were 65 min and 15.5 s, respectively, with a total blood loss of 107.7 mL. The mean duration of hospital stay was 12.8 days. The mean follow-up time was 11.9 months, and all patients achieved radiologically confirmed bony healing in an average time of 13.1 weeks. No lower-leg deformity, fixation failure, infection, and vascular, or nerve injuries were recorded in any patient, and only 4 patients complained of slight limb pain upon total weight-bearing at the end of follow-up. The SMFA and AOFAS ankle-hindfoot scores of patients were graded excellent in 14 (77.8%) and good in 4 (22.2%), indicating high functional recovery. CONCLUSIONS MIPPO technology combined with onionskin bone grafting is an efficient method to treat patients with tibial nonunion, especially for patients with poor soft tissue condition.

Exosomes in the Repair of Bone Defects: Next-Generation Therapeutic Tools for the Treatment of Nonunion

Nonunion with bone defects, a common complication after long bone fracture, is a major challenge for orthopaedic surgeons worldwide because of the high incidence rate and difficulties in achieving successful treatment. Bone defects are the main complications of nonunion. The conventional biological treatments for nonunion with bone defects involve the use of autologous bone grafts or bone graft substitutes and cell-based therapy. Traditional nonunion treatments have always been associated with safety issues and various other complications. Bone grafts have limited autologous cancellous bone and there is a risk of infection. Additionally, problems with bone graft substitutes, including rejection and stimulation of bone formation, have been noted, and the health of the stem cell niche is a major consideration in cell-based therapy. In recent years, researchers have found that exosomes can be used to deliver functional RNA and mediate cell-to-cell communication, suggesting that exosomes may repair bone defects by regulating cells and cytokines involved in bone metabolism. In this review, we highlight the possible relationships between risk factors for nonunion and exosomes. Additionally, we discuss the roles of exosomes in bone metabolism and bone regeneration.

Nonunions of the humerus - Treatment concepts and results of the last five years

PURPOSE

Fractures of the humerus account for 5%-8% of all fractures. Nonunion is found with an incidence of up to 15%, depending on the location of the fracture. In case of a manifest nonunion the surgeon faces a challenging problem and has to conceive a therapy based on the underlying pathology. The aim of this study was to describe our treatment concepts for this entity and present our results of the last five years.

METHODS

Twenty-six patients were treated for nonunion of the humerus between January 2013 and December 2017. Their charts were reviewed retrospectively and demographic data, pathology, surgical treatment and outcome were assessed.

RESULTS

The most frequent location for a nonunion was the humeral shaft, with the most common trauma mechanism being multiple falls. Most often atrophic nonunion (n = 14), followed by hypertrophic and infection-caused nonunion (each n = 4), were found. Our treatment concept could be applied in 19 patients, of which in 90% of those who were available for follow-up consolidation could be achieved.

CONCLUSION

Humeral nonunion is a heterogeneous entity that has to be analyzed precisely and be treated correspondingly. We therefore present a treatment concept based on the underlying pathology.

Diaphyseal long bone nonunions - types, aetiology, economics, and treatment recommendations

The intention of the current article is to review the epidemiology with related socioeconomic costs, pathophysiology, and treatment options for diaphyseal long bone delayed unions and nonunions. Diaphyseal nonunions in the tibia and in the femur are estimated to occur 4.6-8% after modern intramedullary nailing of closed fractures with an even much higher risk in open fractures. There is a high socioeconomic burden for long bone nonunions mainly driven by indirect costs, such as productivity losses due to long treatment duration. The classic classification of Weber and Cech of the 1970s is based on the underlying biological aspect of the nonunion differentiating between "vital" (hypertrophic) and "avital" (hypo-/atrophic) nonunions, and can still be considered to represent the basis for basic evaluation of nonunions. The "diamond concept" units biomechanical and biological aspects and provides the pre-requisites for successful bone healing in nonunions. For humeral diaphyseal shaft nonunions, excellent results for augmentation plating were reported. In atrophic humeral shaft nonunions, compression plating with stimulation of bone healing by bone grafting or BMPs seem to be the best option. For femoral and tibial diaphyseal shaft fractures, dynamization of the nail is an atraumatic, effective, and cheap surgical possibility to achieve bony consolidation, particularly in delayed nonunions before 24 weeks after initial surgery. In established hypertrophic nonunions in the tibia and femur, biomechanical stability should be addressed by augmentation plating or exchange nailing. Hypotrophic or atrophic nonunions require additional biological stimulation of bone healing for augmentation plating.

Long-term outcome following additional rhBMP-7 application in revision surgery of aseptic humeral, femoral, and tibial shaft nonunion

Background

Surgical revision concepts for the treatment of aseptic humeral, femoral, and tibial diaphyseal nonunion were evaluated. It was analyzed if the range of time to bone healing was shorter, and if clinical and radiological long-term outcome was better following application of additional recombinant human Bone Morphogenetic Protein-7 (rhBMP-7) compared to no additional rhBMP-7 use.

Methods

In a retrospective comparative study between 06/2006 and 05/2013, 112 patients diagnosed with aseptic diaphyseal humerus (22 patients), femur (41 patients), and tibia (49 patients) nonunion were treated using internal fixation and bone graft augmentation. For additional stimulation of bone healing, growth factor rhBMP-7 was locally administered in 62 out of 112 patients. Follow-up studies including clinical and radiological assessment were performed at regular intervals as well as after at least one year following nonunion surgery.

Results

One hundred and two out of 112 (humerus: 19, femur: 37, tibia: 47) nonunion healed within 12 months after revision surgery without any significant differences between the cohort groups. According to the DASH outcome measure for the humerus (p = 0.679), LEFS for the femur (p = 0.251) and the tibia (p = 0.946) as well as to the SF-12 for all entities, no significant differences between the treatment groups were found.

Conclusions

Aseptic diaphyseal nonunion in humerus, femur, and tibia healed irrespectively of additional rhBMP-7 application. Moreover, the results of this study suggest that successful nonunion healing can be linked to precise surgical concepts using radical removal of nonunion tissue, stable fixation and restoration of axis, length and torsion, rather than to the additional use of signaling proteins.

Trial registration

This clinical trial was conducted according to ICMJE guidelines as well as to the approval of the National Medical Board (Ethics Committee of the Bavarian State Chamber of Physicians; TRN: 2016-104) and has been retrospectively registered with the German Clinical Trails Register (TRN: DRKS00012652).