Polytherapy versus monotherapy in the treatment of tibial non-unions: a retrospective study

BACKGROUND

Treating tibial non-unions efficiently presents a challenge for orthopaedic trauma surgeons. The established gold standard involves implanting autologous bone graft with adequate fixation, but the addition of biologicals according to the so-called diamond concept has become increasingly popular in the treatment of non-unions. Previous studies have indicated that polytherapy, which involves implanting mesenchymal stem cells, bioactive factors and osteoconductive scaffolds, can improve bone healing. This study aims to evaluate the efficacy of polytherapy compared with monotherapy in treating tibial non-unions of varying severity.

MATERIALS AND METHODS

Data from consecutive tibial non-unions treated between November 2014 and July 2023 were retrospectively analysed. The Non Union Scoring System (NUSS) score before non-union surgery, and the Radiographic Union Score for Tibial fractures (RUST), scored at 1, 3, 6, 9, 12 and 18 months post-surgery, were recorded. Initially, a comparison was made between the polytherapy and monotherapy groups. Subsequently, patients receiving additional surgical non-union treatment were documented, and the frequency of these treatments was tallied for a subsequent per-treatment analysis.

RESULTS

A total of 34 patients were included and divided into a polytherapy group (n = 15) and a monotherapy group (n = 19). The polytherapy group demonstrated a higher NUSS score (44 (39, 52) versus 32 (29, 43), P = 0.019, z = -2.347) and a tendency towards a higher success rate (93% versus 68%, P = 0.104) compared with the monotherapy group. For the per-treatment analysis, 44 treatments were divided into the polytherapy per-treatment group (n = 20) and the monotherapy per-treatment group (n = 24). The polytherapy per-treatment group exhibited a higher NUSS score (48 (43, 60) versus 38 (30, 50), P = 0.030, z = -2.173) and a higher success rate (95% versus 58%, P = 0.006) than the monotherapy per-treatment group. Within the monotherapy per-treatment group, the NUSS score displayed excellent predictive performance (AUC = 0.9143). Setting the threshold value at 48, the sensitivity and specificity were 100.0% and 70.0%, respectively.

CONCLUSIONS

Polytherapy is more effective than monotherapy for severe tibial non-unions, offering a higher success ratio. The NUSS score supports decision-making in treating tibial non-unions.

LEVEL OF EVIDENCE

Level III.

Research on the morphological structure of partial fracture healing process in diabetic mice based on synchrotron radiation phase-contrast imaging computed tomography and deep learning

The prevalence of diabetes mellitus has exhibited a notable surge in recent years, thereby augmenting the susceptibility to fractures and impeding the process of fracture healing. The primary objective of this investigation is to employ synchrotron radiation phase-contrast imaging computed tomography (SR-PCI-CT) to examine the morphological and structural attributes of different types of callus in a murine model of diabetic partial fractures. Additionally, a deep learning image segmentation model was utilized to facilitate both qualitative and quantitative analysis of callus during various time intervals. A total of forty male Kunming mice, aged five weeks, were randomly allocated into two groups, each consisting of twenty mice, namely, simple fracture group (SF) and diabetic fracture group (DF). Mice in DF group were intraperitoneally injected 60 mg/kg 1 % streptozotocin(STZ) solution for 5 consecutive days, and the standard for modeling was that the fasting blood glucose level was ≥11.1 mmol /l one week after the last injection of STZ. The right tibias of all mice were observed to have oblique fractures that did not traverse the entire bone. At three, seven, ten and fourteen days after the fracture occurred, the fractured tibias were extracted for SR-PCI-CT imaging and histological analysis. Furthermore, a deep learning image segmentation model was devised to automatically detect, categorize and quantitatively examine different types of callus. Image J software was utilized to measure the grayscale values of different types of callus and perform quantitative analysis. The findings demonstrated that:1)SR-PCI-CT imaging effectively depicted the morphological attributes of different types of callus of fracture healing. The grayscale values of different types of callus were significantly different(P < 0.01).2)In comparison to the SF group, the DF group exhibited a significant reduction in the total amount of callus during the same period (P < 0.01). Additionally, the peak of cartilage callus in the hypertrophic phase was delayed.3)Histology provides the basis for training algorithms for deep learning image segmentation models. The deep-learning image segmentation models achieved accuracies of 0.69, 0.81 and 0.733 for reserve/proliferative cartilage, hypertrophic cartilage and mineralized cartilage, respectively, in the test set. The corresponding Dice values were 0.72, 0.83 and 0.76, respectively. In summary, SR-PCI-CT images are close to the histological level, and a variety of cartilage can be identified on synchrotron radiation CT images compared with histological examination, while artificial intelligence image segmentation model can realize automatic analysis and data generation through deep learning, and further determine the objectivity and accuracy of SR-PCI-CT in identifying various cartilage tissues. Therefore, this imaging technique combined with deep learning image segmentation model can effectively evaluate the effect of diabetes on the morphological and structural changes of callus during fracture healing in mice.

Interaction between Mesenchymal Stem Cells and Immune Cells during Bone Injury Repair

Fractures are the most common large organ trauma in humans. The initial inflammatory response promotes bone healing during the initial post-fracture phase, but chronic and persistent inflammation due to infection or other factors does not contribute to the healing process. The precise mechanisms by which immune cells and their cytokines are regulated in bone healing remain unclear. The use of mesenchymal stem cells (MSCs) for cellular therapy of bone injuries is a novel clinical treatment approach. Bone progenitor MSCs not only differentiate into bone, but also interact with the immune system to promote the healing process. We review in vitro and in vivo studies on the role of the immune system and bone marrow MSCs in bone healing and their interactions. A deeper understanding of this paradigm may provide clues to potential therapeutic targets in the healing process, thereby improving the reliability and safety of clinical applications of MSCs to promote bone healing.

[Update on non-unions 2022 : Imaging diagnostics, classification and treatment algorithms]

BACKGROUND

Fracture healing is a complex regenerative process. An unconsolidated fracture that will not heal without further surgical intervention is called non-union. The causes are multifactorial. Diagnostic imaging is a central pillar and provides insights into the morphology and biology of the fracture as a basis for optimal surgical treatment decisions.

AIM

Knowledge of fracture healing, targeted radiological and nuclear medical diagnostics, and interdisciplinary standardized classification are of high importance for optimal treatment.

METHODS

In this article, the proven and modern diagnostic procedures are presented, an overview of the currently used scoring and classification models is given and the optimal therapeutic approach based on the extended "diamond concept" is addressed. A possible diagnostic and therapeutic approach is shown using an algorithm.

CONCLUSION

For successful treatment of pseudarthrosis, targeted radiological and nuclear medical diagnostics with old established but also newest methods, such as dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and hybrid imaging, are necessary. An exact classification of non-unions using additional classification models makes it possible to determine and carry out the optimal surgical treatment at an early stage.

Rat bone healing induced by natural nanocrystalline carbonated hydroxyapatite in combination with human amniotic fluid stem cells (AFSCs)

The present study was aimed at identifying a new scaffold/stem cell combination useful to treat large bone defects. Human amniotic fluid stem cells (AFSCs) were expanded in vitro, labeled with a fluorescent cell-permeable dye (PKH26) and transplanted in vivo in a femoral injured rat model. The femoral defect was left untreated (control rats) or filled with hydroxyapatite (HA; natural nanocrystalline carbonated hydroxyapatite-Orthoss®) scaffold alone or loaded with PKH26-labeled AFSCs. All animals were killed 3 weeks after implantation. Both gross anatomy and histological observations revealed a major bone regenerative response in rat specimens treated with HA scaffold, alone or supplemented with AFSCs. Samples injected with HA plus AFSCs displayed the presence of abundant fibrotic tissue, the formation of periosteal woven bone, and an increased presence of blood vessels in the bone marrow, with still fluorescent AFSCs in close proximity. These observations provide evidence that natural HA plus AFSCs represents a promising alternative therapeutic strategy to autologous bone grafting procedures.

Contrast-Enhanced Ultrasound Quantifies the Perfusion Within Tibial Non-Unions and Predicts the Outcome of Revision Surgery

Vascularity is one of the factors determining successful bone regeneration. This prospective study focused on quantifying the microperfusion of tibial non-unions with contrast-enhanced ultrasound (CEUS) 12 wk after revision surgery and comparing it with the osseous consolidation at a maximum of 24 mo assessed with standard radiography and computed tomography. Of 36 patients with tibial non-unions, 28 (77.8%) manifested consolidation, and 8 patients required further revision surgery. CEUS revealed significantly higher perfusion in consolidated versus persistent non-unions for all quantification parameters (e.g., wash-in perfusion index p = 0.036). Receiver operating characteristic analysis revealed a sensitivity of 82.1% and specificity of 75.0% with a wash-in perfusion index cutoff at 19.9 a.u. for diagnosing persisting non-unions. More than 1 y ahead of the final radiologic diagnostic examination, CEUS could predict eventual consolidation based on the osseous perfusion as soon as 12 wk postoperatively. This information can be crucial for the decision-making process for re-revision at an early stage.

Reconstruction of patellar tendon following implantation of proximal tibia megaprosthesis for the treatment of post-traumatic septic bone defects

INTRODUCTION

Latest advances made in joint replacement implants allows reconstruction of entire limbs. These special prostheses or megaprostheses were originally designed for the treatment of severe oncological bone loss. Nowadays, however, the indications and applications of these devices are expanding to other orthopaedic and trauma clinical conditions. Since 2008 we have implanted 152 megaprostheses in non-oncological conditions: 87 were implanted for post-traumatic failures aseptic/septic (represented by complex non-unions and critical size bone defects); 26 total femur, 52 distal femur and 9 proximal tibia. In this group of patients bone and soft tissues conditions are completely different compared to patients with oncological back ground. The presence of infection and previous surgeries can lead to adhesion, scar interference, muscular and tendon impairment and skin problems that lead to reduced function and severe joint stiffness. The purpose of this study is to evaluate the results of treatment of reconstruction of patellar tendon during implantation of proximal tibia megaprosthesis for the treatment of septic post traumatic critical bone defects.

PATIENTS AND METHODS

In this retrospective study, we evaluated 9 patients treated with proximal tibia megaprosthesis who underwent patellar tendon reconstruction. All patients presented a complete patellar tendon disruption at the time of prosthesis implantation. Procedures of reconstruction included a tendon-plasty of quadriceps and/or patellar tendons, a pie crusting of quadriceps fascia, a reinforcement of the apparatus with synthetic tendon graft substitutes (LARS) and a medial gastrocnemius muscular flap to reconstruct the extensor mechanism and obtain skin coverage when needed. The average follow up was 18 months (9-36). For each of the cases, we analysed the complications occurred regarding septic recurrence, patellar fracture, quadriceps and patellar tendon rupture and number of reinterventions. The clinical outcome was assessed by the WOMAC Score.

RESULTS

In all cases there was no infection recurrence or skin related problems. None of the patients require prosthesis revision due to loosening or device failure. No patellar fracture or quadriceps tendon failure was recorded. One patient presented a rupture of the reconstructed patellar tendon due to a trauma incident 18 months after the implantation and he required revision surgery. From a clinical point of view the average WOMAC score was 62.4 at 1 month rising to 72.6 at 3 months, 78.2 at 6 months, 76.4 at 1 year and 74.8 at 18 months.

CONCLUSION

When proximal tibia megaprosthesis is implanted and there are soft tissue and patellar tendon deficiency, soft tissue reconstruction can be achieved by appropriate lengthening of the tendon and a gastrocnemius flap reinforced by LARS. Such an approach allows restoration of the extensor mechanism and coverage of the prosthesis in an area where skin problems are frequently very common.

Complications in proximal humeral fractures

Necrosis of the humeral head, infections and non-unions are among the most dangerous and difficult-to-treat complications of proximal humeral fractures. The aim of this work was to analyse in detail non-unions and post-traumatic bone defects and to suggest an algorithm of care. Treatment options are based not only on the radiological frame, but also according to a detailed analysis of the patient, who is classified using a risk factor analysis. This method enables the surgeon to choose the most suitable treatment for the patient, thereby facilitating return of function in the shortest possible time. The treatment of such serious complications requires the surgeon to be knowledgeable about the following possible solutions: increased mechanical stability; biological stimulation; and reconstructive techniques in two steps, with application of biotechnologies and prosthetic substitution.

Megaprostheses in the management of trauma of the knee

OBJECTIVE

Review the outcome of patients with complex fractures around the knee treated with megaprosthesis.

METHOD

Retrospective observational study of 10 patients was undertaken.

RESULTS

Six patients were treated with a distal femoral endoprosthesis (DEFPR) and four with an augmented rotating hinge knee replacement (RHK). The mean post-operative Toronto Extremity Salvage Score (TESS) was 62.5 for the whole cohort (RHK group 79.3, compared with 49.2 in the DFEPR group (p = 0.038), peri-prosthetic fracture group was 46.3, compared with 75.6 in native knee fracture group (p = 0.04)).

CONCLUSION

A megaprosthesis is a viable option in complex fractures around the knee.

Megaprosthesis in post-traumatic and periprosthetic large bone defects: Issues to consider

INTRODUCTION

The recent evolution of prosthesis technology has enabled the surgeon to replace entire limbs. These special prostheses, or megaprostheses, were developed for the treatment of severe oncological bone loss; however, the indications and applications of these devices have expanded to other orthopaedic and trauma situations. For some years, surgeons have been implanting megaprostheses in non-oncological conditions, such as acute trauma in severe bone loss and poor bone quality; post-traumatic failures, both aseptic and septic (represented by complex non-unions and critical size bone defects); major bone loss in prosthetic revision, both aseptic and septic; periprosthetic fractures with component mobilisation and poor bone stock condition. The purpose of this study was to evaluate retrospectively the complications during and after the implantation of megaprosthesis of the lower limb in post-traumatic and prosthetic bone loss, and to propose tips about how to avoid and manage such complications.

MATERIALS AND METHODS

All the complications and difficulties we have encountered during or after the implantation of megaprosthesis in non-oncology patients were evaluated retrospectively. A total of 72 patients were treated with large resection mono-and bi-articular prostheses between January 2008 and January 2014.

RESULTS

The main critical problems found in the study were: restoration of the correct length and rotation of the limb; reconstruction of the knee extensor mechanism; trochanteric reconstruction; stability/dislocation of the implant; mobility/range of motion (ROM) of the implant; skin cover; sepsis, and bone quality.

CONCLUSION

Megaprosthesis in severe bone loss can be considered as an available solution for the orthopaedic surgeon in extreme, appropriately selected cases. This type of complex surgery must be performed in specialised centres where knowledge and technologies are present. Patients with severe bone loss should not be treated in the same way as oncology patients because life expectancy is definitely longer; therefore, the surgical technique and the system implantation must be extremely rigorous to ensure longevity of the prosthesis. The characteristics of the bone and soft tissue conditions in these patients are very different from those presented by oncology patients, which creates critical problems that the surgeon should be able to manage to avoid serious complications.

Incidence of donor site morbidity following harvesting from iliac crest or RIA graft

INTRODUCTION

Clinical management of non-union of long bone fractures and segmental bone defect is a challenge for orthopaedic surgeons. The use of autologous bone graft (ABG) is always considered the gold standard treatment. Traditional techniques for harvesting ABG from iliac crest usually involve several complications, particularly at the donor site. The Reamer-Irrigator-Aspirator (RIA) is an intramedullary reaming system that generates a large volume of cancellous bone material in a single-step reaming process; this bone material can be collected and potentially used as an ABG source. Our interest is to compare the complications associated with the standard technique of harvesting from iliac crest with those of the innovative RIA harvesting device.

MATERIALS AND METHODS

A database of 70 patients with long bone non-unions was studied. The patients were divided into two groups according to the surgical harvesting technique used: RIA system ABG (35 patients) and iliac crest ABG (35 patients).

RESULTS

At the 12-month follow-up, pain at the donor site was reported in no patients in the RIA system ABG group and five of 35 patients (14.28%) in the iliac crest ABG group. Local infections at the donor site were found in no patients in the RIA system ABG group compared with five patients (14.28%) in the iliac crest ABG group. There were no fractures in the RIA system ABG group and one case (2.85%) of anterior superior iliac spine (ASIS) dislocation in the iliac crest ABG group. No systemic infections were detected in either group.

DISCUSSION

We analysed the scientific literature on the use of RIA technique to collect ABG for use in patients with anthropic-oligotrophic non-unions, with a focus on the complications associated with this technique.

CONCLUSION

RIA bone graft for the treatment of non-unions and segmental bone defect of long bones seems to be a safe and efficient procedure with low donor site morbidity.

Validation of the Non-Union Scoring System in 300 long bone non-unions

INTRODUCTION

Non-union of long bones is a significant consequence of fracture treatment. The ideal classification for non-union of long bones would give sufficient significant information to the orthopaedic surgeon to enable good management of the treatment required and to facilitate the creation of comparable study groups for research purposes. The Non-Union Scoring System (NUSS) is a new scoring system to assist surgeons in the choice of the correct treatment in non-union surgery. The aim of this study was to determine the evidence supporting the use of the NUSS classification in the treatment of non-unions of long bones and to validate the treatment algorithm suggested by this scoring system.

MATERIALS AND METHODS

A total of 300 patients with non-union of the long bones were included in the clinical study.

RESULTS

A radiographic and clinical healing was reached in 60 of 69 non-unions (86%) in group 1 (0-25 points), in 102 of 117 non-unions (87%) in group 2 (26-50 points), and in 69 of 84 (82%) in group 3 (51-75 points). The mean time to clinical healing was 7.17 ± 1.85 months in group 1, 7.30 ± 1.72 months in group 2 and 7.60 ± 1.49 months in group 3. The mean time to radiographic healing was 8.78 ± 2.04 months in group 1, 9.02 ± 1.84 months in group 2 and 9.53 ± 1.40 months in group 3.

DISCUSSION

There are few articles in the scientific literature that examine the classification systems for non-union.

CONCLUSIONS

A statistical analysis of the first results we have obtained with the use of NUSS showed significant rates of union in all the evaluated groups. This indicates that NUSS could be an appropriate scoring system to classify and stratify non-unions and to enable the surgeon to choose the correct treatment.

Treatment of AVN using the induction chamber technique and a biological-based approach: indications and clinical results

OBJECTIVE

To determine the efficacy of core decompression (CD) technique combined with recombinant morphogenetic proteins, autologous mesenchymal stem cells (MSCs) and xenograft bone substitute into the necrotic lesion of the femoral head on clinical symptoms and on the progression of osteonecrosis of the femoral head.

PATIENTS AND METHODS

A total of 38 patients (40 hips) with early stage osteonecrosis of the femoral head were studied over a 4-year period.

RESULTS

CD technique combined with recombinant morphogenetic proteins, autologous MSCs and xenograft bone substitute was associated with a significant reduction in both pain and joint symptoms and reduced the incidence of fractural stages. At 36 months, 33 patients achieved clinical and radiographic healing.

CONCLUSION

This long-term follow-up study confirmed that CD technique combined with recombinant morphogenetic proteins, autologous MSCs and xenograft bone substitute may be an effective treatment for patients with early stage osteonecrosis of the femoral head.

Megaprosthesis in large bone defects: opportunity or chimaera?

INTRODUCTION

The development of new megaprosthesis for the treatment of large bone defects provides important options to orthopaedic oncologic surgeons for the replacement of skeletal segments, such as the long bones of the upper and lower limbs and the relative joints. We implanted megaprosthesis using either a one-step or two-step technique depending on the patient's condition. The aim of this study was to evaluate retrospectively both clinical and radiological outcomes in patients who underwent lower limb megaprosthesis implant.

MATERIALS AND METHODS

A total of 32 patients were treated with mono- and bi-articular megaprosthesis subdivided as follows: proximal femur, distal femur, proximal tibia and total femur. The mean follow-up of patients was about 18 months (range 3 months to 5 years). Clinical and serial radiographic evaluations were conducted using standard methods (X-ray at 45 days, 3, 6, 12, 18 and 24 months) and blood parameters of inflammation were monitored for at least 2 months.

RESULTS

Although the mean length of follow-up was only 18 months, the first patients to enter the study were monitored for 5 years and showed encouraging clinical results, with good articulation of the segments, no somato-sensory or motor deficit and acceptable functional recovery. During surgery and, more importantly, in pre-operative planning, much attention should be given to the evaluation of the extensor apparatus, preserving it and, when necessary, reinforcing it with tendon substitutes.

DISCUSSION

Megaprosthesis in extreme cases of severe bone loss and prosthetic failure is a potential solution for the orthopaedic surgeon. In oncological surgery, the opportunity to restore functionality to the patient (although not ad integrum) is important for both the patient and the surgeon. The high mortality associated with cancer precludes long-term patient follow-up; therefore, there is a lack of certainty about the survival of this type of prosthesis and any medium- to long-term complications that may occur. Nevertheless, patients should be considered as an oncologic patient, not because of the disease, but because of the limited therapeutic options available.

CONCLUSIONS

Megaprosthesis provides a valuable opportunity to restore functionality to patients with highly disabling diseases.

Monotherapy vs. polytherapy in the treatment of forearm non-unions and bone defects

OBJECTIVE

To determinate the efficacy of "polytherapy", a surgical technique that utilize all the components of the diamond concept (mesenchymal stem cells, bone morphogenetic proteins and scaffold) versus a "monotherapy", a surgical technique that utilize only one component of the diamond conceptin the treatment of severe forearm non-unions.

METHODS

We studied a database of 52 patients with 52 forearm non-unions; we classified the patients with the NUSS SCORE and we divided the patients in two group according to the treatment received. So we distinguished a group of patients treated according to the principles of "monotherapy" (33 patients) and a group of patients treated according to the principles of "polytherapy" (19 patients). The minimum follow up was 12 months.

RESULTS

In the monotherapy group 21/33 non-unions (63.64%) went on to develop a radiographic and clinical healing within a period of 12 months, the calculated DASH SCORE showed a mean value of 55.15 points. In the polytherapy group 17/19 (89.47%) nonunions went on to develop clinical and radiographic healing within 12 months, and the average DASH score showed a mean value of 45.47 points.

CONCLUSION

The polytherapy technique with the use of recombinant morphogenetic proteins, autologous MSCs and scaffold in the same surgical time appears to be an effective treatment for patients with severe forearm non-unions.