Tissue engineered strategies for pseudoarthrosis

Acute shortening and re-lengthening versus antibiotic calcium sulfate-loaded bone transport for the management of large segmental tibial defects after trauma

Background

The purpose of this paper was to compare the clinical effects of acute shortening and re-lengthening (ASR) technique with antibiotic calcium sulfate-loaded bone transport (ACSBT) technique for the management of large segmental tibial defects after trauma.

Methods

In this retrospective study, 68 patients with large segmental tibial defects were included and completely followed. The bone loss was 3–10 cm. ASR group included 32 patients, while ACSBT group contained 36. There was no significant difference in demographic information between the two groups. The external fixation time (EFT) and external fixation index (EFI) were compared. Bone defect healing and limb functions were evaluated according to the Association for the Study and Application of the Method of Ilizarov (ASAMI) criteria. Complications were compared by Paley classification.

Results

The mean EFT was 9.2 ± 1.8 months in ASR group and 10.1 ± 2.0 months in ACSBT group, respectively. The mean EFI was 1.5 ± 0.2 month/cm and 1.4 ± 0.3 month/cm. According to the ASAMI criteria, in ASR group bone defect healing was excellent in 22 cases, good in 7 cases and fair in 3 cases. In ACSBT group, it was excellent in 23 cases, good in 11 cases and fair in 2 cases. In ASR group, the limb function was excellent in 15 cases, good in 7 cases and fair in 10 cases, while it was excellent in 14 cases, good in 9 cases and fair in 13 cases with ACSBT group. There was no significant difference in EFI, bone defect healing and limb functions between the two groups (p > 0.05). The mean number of complications per patient in ACSBT group was significantly lower than that in ASR group (p < 0.05).

Conclusion

Both techniques can be successfully used for the management of large segmental tibial defects after trauma. There was no significant difference in EFI, limb functions and bone defect healing between the two groups. Compared with ASR group, the complication incidence in ACSBT group was lower, especially the infection-related complications. Therefore, for patients with large segmental bone defects caused by infection or osteomyelitis, ACSBT technique could be the first choice.

Early definitive internal fixation for infected nonunion of the lower limb

Background

The management of an infected nonunion of long bones is difficult and challenging. A staged procedure comprising radical debridement followed by definitive internal fixation was favored. However, no standard treatment has been established to determine the appropriate waiting period between initial debridement and definitive internal fixation. We propose a management method that incorporates early definitive internal fixation in infected nonunion of the lower limb.

Methods

Thirty-four patients (28 men and 6 women; mean age 46.09 years; range 25–74 years) with infected nonunion of the tibia or femur were included. Initial infected bone resection and radical debridement were performed in each patient in accordance with the preoperative plans. Definitive surgery was performed 2–3 weeks after the resection (4 weeks after flap surgery was required), and a third surgery was performed to fill the bone defect through bone grafting or transport (three-stage surgery). In cases of unplanned additional surgery, the reason for the requirement was analyzed, and radiological and functional results were investigated in accordance with the Association for the Study and Application of the Method of Ilizarov criteria.

Results

Bone union was achieved in all patients, and treatment was conducted as planned preoperatively in 28 patients (28/34, 82.35%). The mean interval between primary debridement and secondary definitive fixation was 2.76 weeks (range 2–4 weeks). Six unplanned additional surgeries were performed, and the infection relapsed in two cases. The radiological and functional outcomes were good or better in 32 and 31 patients, respectively.

Conclusions

Early definitive surgery can be performed to treat infected nonunion by thorough planning and implementation of radical resection, active response to infection, restoration of defective bones, and soft tissue healing through a systemic approach.

Biomorphic Transformations: A Leap Forward in Getting Nanostructured 3-D Bioceramics

Obtaining 3-D inorganic devices with designed chemical composition, complex geometry, hierarchic structure and effective mechanical performance is a major scientific goal, still prevented by insurmountable technological limitations. With particular respect to the biomedical field, there is a lack in solutions ensuring the regeneration of long, load-bearing bone segments such as the ones of limbs, due to the still unmet goal of converging, in a unique device, bioactive chemical composition, multi-scale cell-conducive porosity and a hierarchically organized architecture capable of bearing and managing complex mechanical loads in a unique 3D implant. An emerging, but still very poorly explored approach in this respect, is given by biomorphic transformation processes, aimed at converting natural structures into functional 3D inorganic constructs with smart mechanical performance. Recent studies highlighted the use of heterogeneous gas-solid reactions as a valuable approach to obtain effective transformation of natural woods into hierarchically structured apatitic bone scaffolds. In this light, the present review illustrates critical aspects related to the application of such heterogeneous reactions when occurring in the 3D state, showing the relevance of a thorough kinetic control to achieve controlled phase transformations while maintaining the multi-scale architecture and the outstanding mechanical performance of the starting natural structure. These first results encourage the further investigation towards the biologic structures optimized by nature along the ages and then the development of biomorphic transformations as a radically new approach to enable a technological breakthrough in various research fields and opening to still unexplored industrial applications.

Platelet-Rich Plasma, Mesenchymal Stem Cell, and Non-metallic Suture-Based Fixation Technique in a Patellar Fracture Nonunion: A Technical Note and Systematic Review

Backgroud

We performed a systematic review on the management of patellar fracture nonunion and report a novel suture-based non-metallic fixation technique associated with platelet-rich plasma and mesenchymal stem cell injections in the management of this injury.

Methods

A systematic search was performed up to August 2020 in PubMed and Scopus electronic databases of scholarly articles evaluating different surgical techniques used for nonunion of patellar fractures, with no restrictions on language or year of publication. Furthermore, we describe our novel non-metallic suture fixation technique and a patient in whom this technique was applied.

Results

A total of 9 articles were included in the systematic review. Tension band wiring was the most commonly used procedure (62.7%). Nonoperative procedures (8.1%) resulted in nonunion in all patients. The most common complication after open reduction and internal fixation was infection (7.8%). Our patient at the latest follow-up reported full functional recovery and full extension and flexion of the affected knee with no pain and subjectively normal strength.

Conclusions

The management of patella nonunions is still a challenge. The technique reported here can be used in patellar fracture nonunion, as well as in primary patellar fractures.

Tips and tricks to achieve osteotomy healing and prevent refracture after ulnar shortening osteotomy

BACKGROUND

Parallel osteotomy is essential for favorable osteotomy reduction and healing and technically challenging during diaphyseal ulnar shortening osteotomy (USO). This study aimed to evaluate the advantages of guided osteotomy for parallel osteotomy and reduction osteotomies, healing over freehand osteotomy. It also aimed to identify surgical factors affecting healing after diaphyseal USO.

METHODS

Between June 2005 and March 2016, 136 wrists that had undergone diaphyseal USO for ulnar impaction syndrome (UIS) were evaluated. The wrists were divided into two groups according to the osteotomy technique (group 1: freehand osteotomy, 74 wrists; group 2: guided osteotomy, 62 wrists). The osteotomy reduction gap and time to osteotomy healing (union and consolidation) were compared between the groups. A multiple regression test was performed to identify the surgical factors affecting healing. The cut-off length of the reduction gap to achieve osteotomy union on time and the cut-off period to decide the failure of complete consolidation were statistically calculated.

RESULTS

The baseline characteristics did not differ between the two groups. The osteotomy reduction gap and time to osteotomy union, and complete consolidation were shorter in group 2 than in group 1 (p = 0.002, < 0.001, 0.002). The osteotomy reduction gap was a critical surgical factor affecting both time to osteotomy union and complete consolidation (p < 0.001, < 0.001). The use of a dynamic compression plate affected only the time to complete consolidation (p < 0.001). The cut-off length of the osteotomy reduction gap to achieve osteotomy union on time was 0.85 mm. The cut-off period to decide the failure of complete consolidation was 23.5 months after osteotomy.

CONCLUSIONS

The minimal osteotomy reduction gap was the most important for timely osteotomy healing in the healthy ulna, and guided osteotomy was beneficial for reducing the osteotomy reduction gap.

The Effect of Smoking on Posttraumatic Pseudoarthrosis Healing after Internal Stabilization, Treated with Platelet Rich Plasma (PRP)

Disturbed or delayed healing remains one of the most serious fracture-related complications, despite bone capacity for internal regeneration and reabsorption. Considerable progress in the understanding and treatment of fractures has been noted. The aim of our study was to evaluate treatment outcome in patients (smokers and non-smokers) with post-traumatic pseudoarthrosis.

Hypothesis

Determinate when administration of growth factors is most beneficial, and whether it accelerates bone union.

Material and methods

The study included patients treated for post-traumatic pseudoarthrosis resulting from multiple bone fractures. The study group and controls were further subdivided into: non-smokers, non-smokers >2 years after quitting, and smokers. Independent tests were performed for men and women. The study group, apart from other methods of treatment, received concentrated PRP (platelet-rich plasma) to aid the process of bone healing, or in cases of delayed healing confirmed by radiological assessment on follow-up visits.

Results

Mean time of fracture healing was 8 weeks for non-smokers and non-smokers >2 years after quitting, whereas in smokers the healing process was significantly prolonged (18 weeks in both, men and women).

Conclusions

The risk for infection is smaller in non-smokers as compared to smokers, with the latter being at an elevated risk for bone inflammation and delayed union.

Subcutaneous emphysema of the leg after hardware removal and bone allografting for infected non-union of the distal femur

Background

Infected non-unions of the supracondylar region of the femur are uncommon. Even though hardware removal is a common procedure, it may lead to complications, including neurovascular injury, refracture, worsening pain or recurrence of deformity.

Case presentation

We report on a male who developed subcutaneous emphysema of the leg after hardware removal and bone allografting for an infected non-union of the distal femur. He was managed by debridement of the surgical wound, antibiotic therapy, multiple fasciotomies, and application of a VAC (vacuum-assisted closure) system.

Conclusions

Although subcutaneous emphysema of the leg after hardware removal and bone allografting for infected non-union of the distal femur is extremely rare, the potential life treating complications and their potential impact on the functional status of the patient have to be taken into consideration when counseling patients about this procedure. Even when it is not possible to identify a bacterial pathogen responsible for the subcutaneous emphysema of the leg, prompt intervention may save the limb of the patient.

Guided tissue regeneration with heterologous materials in primary subtalar arthrodesis: a case report

BACKGROUND

Calcaneal fractures are relatively rare and difficult to treat. Treatment options vary based on the type of fracture and the surgeon's experiences. In recent years, surgical procedures have increasingly been used due to the better long-term results. We present a case where guided tissue regeneration was performed in a calcaneal fracture that needed primary subtalar arthrodesis. We used the principles of guided tissue regeneration from oral surgery to perform primary subtalar arthrodesis and minimize the risk of non-union. We used a heterologous collagen membrane, which acts as a mechanical barrier and protects the bone graft from the invasion of unwanted cells that could lead to non-union. The collagenous membrane also has osteoconductive properties and is therefore able to increase the osteoblast proliferation rate.

CASE PRESENTATION

A 62-year-old Caucasian woman sustained multiple fractures of her lower limbs and spine after a fall from a ladder. Her left calcaneus had a comminuted multifragmental fracture (Sanders type IV) with severe destruction of the cartilage of her subtalar joint and depression of the Böhler's angle. Therefore, we performed primary arthrodesis of her subtalar joint with elevation of the Böhler's angle using a 7.3 mm titanium screw, a heterologous cortico-cancellous collagenated pre-hydrated bone mix, a heterologous cancellous collagenated bone wedge, and a heterologous collagen membrane (Tecnoss®, Italy). The graft was fully incorporated 12 weeks after the procedure and a year and a half later our patient walks without limping. We present a new use of guided tissue regeneration with heterologous materials that can be used to treat extensive bone defects after bone injuries.

CONCLUSIONS

We believe that guided tissue regeneration using heterologous materials, including a heterologous collagen membrane that presents a mechanical barrier between soft tissues and bone as well as a stimulative component that enhances bone formation, could be more often used in bone surgery.

Treatment of nonunion in neglected long bone shaft fractures by osteoperiosteal decortication

In emerging countries, nonunion in the shaft of fractured long bones is common.

PATIENTS AND METHODS

In a 3-year long prospective study, 50 patients (38 men, 12 women) with an average age of 40.9 years (range 17-60) were treated for neglected diaphyseal nonunion an average of 11 months (range 6-48) after the fracture event. The femur was involved 14 times, tibia 22 times, humerus eight times and forearm bones six times. All of these patients had consulted initially with a traditional bone setter at the time of fracture. The surgical procedure consisted of osteoperiosteal decortication followed by repermeabilization of the medullary canal and then internal fixation. Compression plating was used for the humerus, radius and ulna. Nonunion of the middle-third of the femur and tibia was treated by intramedullary nailing and nonunion of the proximal third of the femur with an inverted DCS screw-plate. Patients were reviewed clinically and with X-rays on postoperative days 21, 45, 90 and 120.

RESULTS

Bone union was obtained in under 90 days in the upper limb and under 120 days in the lower limb. No additional grafting was needed. There were only two cases of leg length differences.

DISCUSSION

Osteoperiosteal decortication is a reliable technique that leads to predictable, satisfactory results, given the limited materials required to treat long bone nonunion in emerging countries.

New insights into osteogenic and chondrogenic differentiation of human bone marrow mesenchymal stem cells and their potential clinical applications for bone regeneration in pediatric orthopaedics

Human mesenchymal stem cells (hMSCs) are pluripotent adult stem cells capable of being differentiated into osteoblasts, adipocytes, and chondrocytes. The osteogenic differentiation of hMSCs is regulated either by systemic hormones or by local growth factors able to induce specific intracellular signal pathways that modify the expression and activity of several transcription factors. Runt-related transcription factor 2 (Runx2) and Wnt signaling-related molecules are the major factors critically involved in the osteogenic differentiation process by hMSCs, and SRY-related high-mobility-group (HMG) box transcription factor 9 (SOX9) is involved in the chondrogenic one. hMSCs have generated a great interest in the field of regenerative medicine, particularly in bone regeneration. In this paper, we focused our attention on the molecular mechanisms involved in osteogenic and chondrogenic differentiation of hMSC, and the potential clinical use of hMSCs in osteoarticular pediatric disease characterized by fracture nonunion and pseudarthrosis.