Hypertrophic nonunion management with distraction osteogenesis: a scoping review of the literature.

Introduction: Traditionally, stiff hypertrophic nonunions have been managed with open preparation of the nonunion site, which is then secured with internal fixation. Alternative surgical options are available including distraction osteogenesis with an external fixator. There is currently a limited amount of literature pertaining to the use of distraction osteogenesis in the management of hypertrophic nonunion. The aim of this systematic review was to collate and assess the effectiveness of distraction osteogenesis (DO) in the management of hypertrophic nonunions and to evaluate the complications that are commonly reported in the literature. Methods: We searched for articles pertaining to the treatment of hypertrophic nonunion using distraction osteogenesis. Several electronic bibliographic databases and clinical trial registries were searched using the MeSH terms "hypertrophic non-union," "distraction osteogenesis," "stiff non-union," and "External Fixation" in various combinations to return the maximal number of studies for review. We performed a systematic review and identified a total of 11 studies eligible for review. Results: The review of the literature demonstrated that this technique is highly effective in achieving bony union with minimal complications. The most common complication is mild superficial pin site infections, usually managed with oral antibiotics and effective wound hygiene. Other complications reported were deep pin tract infections, broken hardware, and deformity recurrence due to collapse of regenerate bone. Conclusion: The use of distraction osteogenesis with external fixator devices is an effective and safe method for producing bony union in hypertrophic nonunions. There were minimal associated complications.

Universal Long Bone Nonunion Classification.

Aim and background: The management of bone union disorders is a complex problem in orthopaedics, requiring a reliable and comprehensive classification system for accurate diagnosis and treatment. Despite advances in understanding pathophysiology, diagnosis, and treatment in this area, there is no generally accepted classification system. The aim of our work was to create a comprehensive classification, which will systemize the vast majority of bone union disorders, underline their differences and form the basis for their treatment. Methods: The key criteria for nonunion evaluation and treatment were identified based on the conducted literature review: Time from the initial event (delayed union or nonunion), location, type of pathology (A, Hypertrophic; B, Normotrophic; C, Oligotrophic) and the presence of hardware. Based on these criteria the ULBNC has been developed. Atrophic nonunions were excluded from this classification as they are considered segmental bone defects with special classification. Results: The ULBNC is based on the same principles of coding as the "gold standard" AO/OTA Fractures Classification system with alpha-numeric coding "from simple to complex." The choice of treatment method depends on the type, group, and subgroup of the nonunion as described. Conclusion: Universal Long Bone Nonunion Classification (ULBNC) is an alphanumeric system that describes the localization, type of pathology and morphologic characteristics of a nonunion. The use of ULBNC in practice and research will optimize and standardize the treatment of various types of bone healing disorders and eventually improve clinical outcomes. How to cite this article: Solomin LN, Semenistyy AA, Komarov AV, et al. Universal Long Bone Nonunion Classification. Strategies Trauma Limb Reconstr 2023;18(3):169-173.

Compresión-distracción en el tratamiento de pseudoartrosis de tibia distal utilizando el aparato de Ilizarov: reporte de casos / Compression-distraction in the treatment of distal tibial no union using the Ilizarov apparatus: case report / Compressão-distração no tratamento da pseudoartrose distal da tibia com Ilizarov: relato de caso

El método de Ilizarov, con sus diferentes variantes y mediante la utilización de su aparato, desarrollado en la década del 50, continúa vigente, sobre todo en el tratamiento de las complicaciones de fracturas, principalmente aquellas vinculadas a la infección y a las dificultades de la consolidación. Reportamos 2 pacientes adultos con diagnóstico de pseudoartrosis hipertrófica, rígida, con deformidad, sin infección activa y sin dismetría, tratados mediante el método de distracción y compresión realizado con el aparato de Ilizarov. En ambos casos se logró la alineación y consolidación del miembro con escasas complicaciones.

The Ilizarov method, with its different variants and using its apparatus, developed in the 1950s, is still valid, especially in the treatment of fracture complications, mainly those linked to infection and consolidation difficulties. We report 2 adult patients with a diagnosis of hypertrophic, rigid nonunion, with deformity, without active infection and without dysmetria, treated by the distraction and compression method performed with the Ilizarov device. In both cases, the alignment and consolidation of the limb was achieved with few complications.

O método de Ilizarov, com suas diferentes variantes e pelo uso de seu aparato, desenvolvido na década de 1950, ainda é válido, principalmente no tratamento de complicações de fraturas, principalmente aquelas ligadas à infecção e dificuldades de consolidação. Relatamos 2 pacientes adultos com diagnóstico de pseudoartrose hipertrófica, rígida, com deformidade, sem infecção ativa e sem dismetria, tratados pelo método de distração e compressão realizado com o dispositivo de Ilizarov. Em ambos os casos, o alinhamento e a consolidação do membro foram alcançados com poucas complicações.

Human Non-Hypertrophic Nonunion Tissue Contains Osteoblast Lineage Cells and E-BMP-2 Activates Osteogenic and Chondrogenic Differentiation.

In this study, we examined the proliferation capability and osteogenic and chondrogenic differentiation potential of non-hypertrophic nonunion cells (NHNCs), and the effect of Escherichia coli-derived BMP-2 (E-BMP-2) on them. We enrolled five patients with non-hypertrophic nonunion. NHNCs isolated from nonunion tissue sampled during surgery were cultured, passaged, counted every 14 days, and analyzed. NHNCs were homogenous fibroblastic adherent cells and long-lived through at least 10 passages, with a slight decline. The cells were consistently positive for mesenchymal stem cell-related markers CD73 and CD105, and negative for the hematopoietic markers CD14 and CD45. NHNCs could differentiate into osteoblast lineage cells; however, they did not have strong calcification or sufficient chondrogenic differentiation capability. E-BMP-2 did not affect the proliferative capability of the cells but improved their osteogenic differentiation capability by increasing alkaline phosphatase activity and upregulating the gene expression of osterix, bone sialoprotein, and osteocalcin. E-BMP-2 enhanced their chondrogenic differentiation capability by upregulating the gene expression of aggrecan and collagen type II. We showed, for the first time, that NHNCs have the capacity to differentiate into osteoblast-lineage cells, although the chondrogenic differentiation potential was poor. Local application of E-BMP-2 with preservation of nonunion tissue is a potential treatment option for non-hypertrophic nonunion.

Morel-Lavallee Lesion Associated with Subtrochanteric Femur Fracture in a Young Female Resulting in Extensive Soft-Tissue Necrosis and Hypertrophic Non-union Managed with Staged Surgeries and Exchange Nailing: A Rare Injury Pattern and Review of Literature.

Introduction: Morel-Lavallee lesion is a closed degloving soft-tissue injury which occurs as a result of acute traumatic separation of skin and subcutaneous tissue from the underlying fascia and muscle layer. The most common sites include thigh (peritrochanteric region), abdomen, scapula, and paraspinal area. Early diagnosis and management of the lesion is essential so as to prevent complications such as infections or extensive skin necrosis. The management options include conservative or operative depends on extent, location of lesion, and duration since injury. For the management of underlying fracture, one should take into the consideration, the soft tissue compromises which can occur if lesion is large at presentation and plan accordingly for either primary definitive fixation or staged surgeries as necessary. Case Report: A 25-year-old female patient presented with pain and swelling over the anterolateral aspect of the right thigh after a traumatic road traffic accident 2 days back. On radiological investigation, there was subtrochanteric femur fracture with a butterfly fragment. The patient also had Morel-Lavallee lesion on local ultrasound. Emergency management was done for Morel-Lavallee lesion in the form of percutaneous drainage and compression bandage; fixation was done in the form of external fixator. The wound progressed into complete skin necrosis so external fixator was removed and thorough wound debridement was done. Fracture stabilized with four TENS nails (titanium elastic nail). Removal of the TENS nail and exchange nailing in the form of intramedullary interlocking nail was performed after complete soft-tissue healing. Bony union seen at the fracture site clinically and radiologically at 3-month follow-up. Conclusion: Initial screening of lesion is very important at time of presentation. Early definitive fixation should not be done if the lesion is large and one should fix the bone once the lesion is resolved.

Quantitative bone single-photon emission computed tomography imaging for uninfected nonunion: comparison of hypertrophic nonunion and non-hypertrophic nonunion.

BACKGROUND: Recently, a standardized uptake value (SUV) has been used to evaluate bone single-photon emission computed tomography (SPECT). The aim of this study was to investigate quantitative SPECT imaging of uninfected nonunion to compare hypertrophic nonunion and non-hypertrophic nonunion using volume-based parameters. METHODS: We evaluated 23 patients with uninfected nonunion who underwent SPECT acquisition 3 h after an injection of 99mTc-hydroxymethylene diphosphonate or 99mTc-methylene diphosphonate from April 2014 to November 2019. We reconstructed the acquired data and performed voxel-based quantitative analysis using the GI-BONE software. Quantitative parameters, maximum SUV (SUVmax), peak SUV (SUVpeak), and mean SUV (SUVmean) in the high and low uptake areas of nonunion were compared between hypertrophic nonunion and non-hypertrophic nonunion. The contralateral limb was used as a control, and the ratios of the quantitative parameters were calculated. RESULTS: The values for the quantitative parameters (high uptake area/low uptake area, respectively), SUVmax control ratio (12.13 ± 4.95/6.44 ± 4.71), SUVpeak control ratio (11.65 ± 4.58/6.45 ± 4.64), and SUVmean control ratio (11.94 ± 5.03/6.28 ± 4.95) for hypertrophic nonunion were higher than those for non-hypertrophic nonunion (7.82 ± 4.76/3.41 ± 2.09 (p = 0.065/0.12), 7.56 ± 4.51/3.61 ± 2.23 (p = 0.065/0.22), and 7.59 ± 5.18/3.05 ± 1.91 (p = 0.076/0.23)). CONCLUSIONS: SUVmax, SUVpeak, and SUVmean control ratios obtained from bone SPECT images can quantitatively evaluate the biological activity of nonunions and may be an effective evaluation method for treatment decisions, especially the necessity of autologous bone grafting.

Establishing a rat model of atrophic nonunion by using circular external fixator combined with periosteum cauterization / 中国组织工程研究

BACKGROUND: Establishment of a standard experimental animal model of atrophic nonunion is necessary for experimental study and related treatment of atrophic nonunion. However, the common modeling methods cannot accurately simulate atrophic nonunion in the clinical practice. OBJECTIVE: To construct a standard animal model of atrophic nonunion. METHODS: Thirty male Sprague-Dawley rats were randomly divided into experimental and control groups. All animals were subjected to bone cutting at the middle-lower segment of the right tibia and the circular external fixator was applied to keep a 4 mm defect interval. The animals in the experimental group were subjected to an additional cauterization of the periosteum at the fracture end of the tibia with a length of 1 mm. The periosteum was not treated in the control group. The study protocol was approved by the Experimental Animal Ethics Committee of the First Affiliated Hospital of Guangzhou University of Chinese Medicine on January 01, 2018, with approval No. TCMF1-2018002. RESULTS AND CONCLUSION: After modeling, there was one case of loose external fixation in each group, and no infection occurred in both groups. Imaging examination showed no bone connection and no sign of healing between the fractures of the tibia in the two groups at 6 weeks after modeling. Imaging and histological findings showed no healing at the end of fracture but typical atrophic nonunion in the experimental group at 12 weeks after modeling. By contrast, six animals had atrophic nonunion, and eight had hypertrophic nonunion in the control group. Overall, the animal model of atrophic tibial nonunion can be successfully constructed using circular external fixator combined with periosteal cauterization at the fracture end.

Treatment of distal clavicle nonunion with and without bone grafting.

The management of distal clavicle nonunion represents a challenging task for orthopaedic trauma surgeon. Both the choice of the implant and whether a bone graft is needed are controversial points which must be addressed. Particularly, in the case of a hypertrophic nonunion, grafting may not necessarily be needed, but given a poor underlying biological environment, a bone graft becomes necessary in order to enhance fracture healing. We report the case of a 62-year-old patient who came to us with a hypertrophic nonunion of the left distal clavicle. She was initially treated with a hook plate without bone grafting. After an early peri-implant fracture she was treated again with anatomical S-shaped locking plate associated with autologous cancellous bone graft.

Compression Osteosynthesis - An Effective Solution for Hypertrophic Nonunion of Tibia in Children.

INTRODUCTION: Hypertrophic non-union of the tibia is rare in children. Gradual deformity correction by distraction osteogenesis is the conventional management strategy for this problem. In cases with significant multiplanar deformities, this needs careful pre-operative planning and execution that involves long periods of "dynamic" phase of Ilizarov method. CASE REPORT: We devised a simpler strategy of complete intraoperative deformity correction in one or two stages followed by compression osteosynthesis. We report the good outcome in four patients (3 males, and 1 female, age 4--years) with regard to union, alignment, limb length, and function, with significantly short duration of the "dynamic" phase of Ilizarov osteosynthesis. CONCLUSION: Acute deformity correction and compression osteosynthesis is are an effective strategy in hypertrophic non-union of tibia in children. This is applicable for cases with significant deformity without shortening. This considerably shortens the "dynamic" phase of Ilizaov osteosynthesis, facilitating early return to home of patients who need to travel long distances for treatment.

Etiology and Management of Nonunion / 대한정형외과학회잡지

Nonunion is caused by various factors related to fracture characteristics, patient characteristics, treatment, and infection. Aseptic nonunion, is divided into three categories in accordance with the biological activity of the fracture: atrophic nonunion, oligotrophic nonunion, and hypertrophic nonunion. Treatment of nonunion depends on the cause and classification. Here, we report our experiences and review the various causes of nonunion and treatment methods available.

Multi-Rod Constructs Can Prevent Rod Breakage and Pseudarthrosis at the Lumbosacral Junction in Adult Spinal Deformity.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To determine if patients fused with multi-rod constructs to the pelvis have a lower incidence of lumbosacral rod failure and pseudarthrosis than those fused with dual-rod constructs. METHODS: We performed a retrospective review of consecutive adult spinal deformity patients who underwent long fusion to the pelvis. Inclusion criteria were >5 levels, primary fusion or revision for L5-S1 pseudarthrosis, and minimum 1-year follow-up. Revision patients with indications other than L5-S1 pseudarthrosis were excluded. One-year follow-up plain radiographs were reviewed for rod integrity, and computed tomography scan (CT) was obtained whenever rod breakage was observed. Dual-rod and multi-rod (3 or 4 rods) cohorts were statistically compared. RESULTS: There were 31 patients with 15 in the dual-rod group and 16 in the multi-rod group, with average ages of 68 ± 9 and 63 ± 12 years, respectively. No patients in the multi-rod group experienced rod fracture, whereas 6 in the dual-rod group fractured a rod (P = .007), with 4 occurring at the lumbosacral junction (P = .04). CT scan in the 4 lumbosacral rod fracture cases, and surgical exploration in 3, confirmed pseudarthrosis and hypertrophic nonunion at the L5-S1 junction. CONCLUSION: Patients with dual-rod constructs had a statistically greater incidence of lumbosacral pseudarthrosis with implant failure than those with multi-rod constructs. CT and surgical exploration showed hypertrophic nonunion as opposed to oligo- or atrophic nonunion. This suggests that mechanical instability, not biology, is the main reason for failure, and could be addressed with the use of multi-rods.

Minimally invasive plate augmentation in the treatment of long-bone non-unions.

INTRODUCTION: Exchange nailing is most acceptable for treating hypertrophic non-union of the long bones, requiring the removal of previously fixed implant. However, its main effect of mechanical stabilization is controversial in non-isthmal area. We hypothesized that minimally invasive plate augmentation over the non-union site may have a better option, without the need of bone grafting or removing pre-existing implants. MATERIALS AND METHODS: Seventeen patients with hypertrophic non-union of the long bones between 2010 and 2014 on radiography who previously underwent intramedullary (IM) nailing or plate osteosynthesis for long-bone fractures were included. A locking compression plate was inserted with at least three mono- or bicortical screws at each proximal and distal segment. Broken or loosened interlocking screws of IM nail were simultaneously re-fixed. Fracture site exposure, pre-fixed implant removal, and bone grafting were not performed. We investigated whether union occurred and analyzed functional outcomes and complications. RESULTS: Eleven femoral and six tibial non-unions were prospectively included. In the pre-existing implants, 13 nails and 4 plates were found. All cases achieved union at a mean 22.7 weeks. One case of superficial infection was managed with oral antibiotics. Deep infection or implant failure did not occur. CONCLUSIONS: Minimally invasive plate augmentation can achieve additional stability and promote healing of hypertrophic non-union of the long bones. When indicated, this technique is the least invasive alternative to exchange nailing and reduces surgical risks in the treatment of diaphyseal non-union.

The callus fracture sign: a radiological predictor of progression to hypertrophic non-union in diaphyseal tibial fractures.

We report a radiological sign which predicts progression to hypertrophic non-union for fractures of the tibial diaphysis. Radiographs of 46 tibial fractures were reviewed independently by four orthopaedic trauma surgeons and two musculoskeletal radiologists. Patients were identified from a database of tibial fractures managed with Ilizarov frame fixation. There were 23 fractures that progressed to non-union requiring further surgery. The controls were 23 fractures that had united without need for further surgery at 1-year follow-up. Radiographs selected were the first images taken following frame removal. All radiographs were anonymised and randomized prior to review. Presence of the callus fracture sign was identified in 16 radiographs of the fractures that progressed to non-union, and 7 of the united fracture group. Sensitivity is 69.6 %. Specificity is 91.4 %. Positive and negative predictive values are 88.9 and 75.0 %, respectively. These results compare favourably with computerised tomography for predicting non-union. Intra- and inter-observer reliability was good (κ = 0.68), and moderate (κ = 0.57), respectively. The callus fracture sign is a useful radiological predictor of progression to non-union and may represent insufficient mechanical stability at the fracture site.

Management of hypertrophic nonunion with failure of internal fixation by distraction osteogenesis.

INTRODUCTION AND AIM: Distraction osteogenesis is employed in the management of hypertrophic nonunion associated with angular deformity and shortening. This study was aimed at evaluating the outcomes of Ilizarov apparatus without bone graft or open osteotomy in cases of hypertrophic nonunion not responding to treatment with internal fixation. METHODS: We retrospectively reviewed the data of 12 patients (mean age, 46.5 years) treated for hypertrophic nonunion at our institution. All patients had two-plane angular deformities (mean, 19° and 23.5° in sagittal and frontal plane, respectively) and limb-length discrepancy (mean, 3.8cm). The Ilizarov apparatus was used to simultaneously treat the nonunion, malalignment, and limb-length discrepancy. RESULTS: The mean follow-up duration after the removal of the apparatus was 42 months. In all cases, bone union had been achieved within an average of 8 months after a single surgery, without the need for any additional procedure. Additionally, none of the patients had recurrence of limb-length discrepancy or malalignment during the follow-up period. Complications of superficial pin-tract infections and mild Achilles tendon contracture were observed, but they resolved over time. All patients were satisfied with the outcome of the surgery. CONCLUSION: Patients with hypertrophic nonunion associated with internal fixation failure can be treated by using the Ilizarov apparatus, thereby eliminating the need for bone graft or open osteotomy. Distraction osteogenesis appears to be effective as a minimally invasive percutaneous procedure in the treatment of hypertrophic nonunion with deformity and shortening.

The Use of Poller Screws in Nonunion of Femoral Shaft Following Intramedullary Nailing of Femoral Shaft Fracture: A Case Report / 대한정형외과학회잡지

As intramedullary nailing became more common in the treatment of femur shaft fractures, the incidence of nonunion increased which led to various treatment modalities for this complication. Accurate diagnosis of the etiology of nonunion and appropriate treatment is essential. Poller screws can help in preventing possible sagittal malalignment after intramedullary nail fixation and also be a minimally invasive method to treat hypertrophic nonunion derived from bone fragment mobility. We report 1 case along with literature review for the treatment of hypertrophic nonunion in femur.

Hypertrophic Non-union of the First Rib Causing Thoracic Outlet Syndrome: A Case Report

We experienced a rare case of thoracic outlet syndrome caused by hypertrophic nonunion of the first rib. A diagnosis was made mainly upon provocative tests and imaging studies. Pain and tingling could be reproduced and the radial pulse obliterated by the hyperabduction test. Abundant callus formation on the posterior aspect of the first rib with fracture line was visible on plain radiograph. Two-dimensional computed tomography showed right thoracic outlet narrowing mainly caused by the mass-effect of the callus. Dynamic arteriographic studies revealed an external compression of the right subclavian artery and duplex ultrasonography demonstrated a reduction in right subclavian artery blood flow when the shoulder is in 90 degrees of abduction. Surgery was performed after the conservative management for three months which failed to relieve the patient of his complaints. Resection of the first rib via transaxillary approach was undergone uneventfully in combination with the myotomy of the scalenus anticus muscle. At postoperative one year follow up, the patient was free of symptoms, and had a full range of motion of the right shoulder with no evidence of arterial insufficiency.