Aim

Segmental bone defects following osteomyelitis in pediatric age group may require specifically designed surgical options. Clinical and radiographic elements dictate the option. Different elements play a role on the surgeon's choice. Among them, the size of the defect, the size and the quality of the bone stock available, the status of the skin envelope, the involvement of the adjacent joint. When conditions occur, vascularized fibula flap may represent a solution in managing defects of the long bones even during the early years of life.

Non-traumatic osteonecrosis of the femoral head is a potentially devastating condition, the prevalence of which is increasing. Many joint-preserving forms of treatment, both medical and surgical, have been developed in an attempt to slow or reverse its progression, as it usually affects young patients.

However, it is important to evaluate the best evidence that is available for the many forms of treatment considering the variation in the demographics of the patients, the methodology and the outcomes in the studies that have been published, so that it can be used effectively.

The purpose of this review, therefore, was to provide an up-to-date, evidence-based guide to the management, both non-operative and operative, of non-traumatic osteonecrosis of the femoral head.

Cite this article: Bone Joint J 2017;99-B:1267–79.

Aims

The aims of this study were to analyse the long-term outcome of vascularised fibular graft (VFG) reconstruction after tumour resection and to evaluate the usefulness of the method.

Aims

The aim of the study was to compare measures of the quality of life (QOL) after resection of a chordoma of the mobile spine with the national averages in the United States and to assess which factors influenced the QOL, symptoms of anxiety and depression, and coping with pain post-operatively in these patients.

We developed a 3D vascularized bone remodeling model embedding human osteoblast and osteoclast precursors and endothelial cells in a mineralized matrix. All the cells included in the model exerted their function, resulting in a vascularized system undergoing mineralized matrix remodeling.

Bone remodeling is a dynamic process relying on the balance between the activity of osteoblasts and osteoclasts which are responsible for bone formation and resorption, respectively. This process is also characterized by a tight coupling between osteogenesis and angiogenesis, indicating the existence of a complex cross-talk between endothelial cells and bone cells. We have recently developed microscale in vitro hydrogel-based models, namely the 3D MiniTissue models, to obtain bone-mimicking microenvironments including a 3D microvascular network formed by endothelial cell self-assembly [1–2]. Here, we generated a vascularized 3D MiniTissue bone remodeling model through the coculture of primary human cells in a 3D collagen/fibrin (Col/Fib) matrix enriched with CaP nanoparticles (CaPn) to mimic bone mineralized matrix.

Human umbilical vein endothelial cells (HUVECs), bone marrow mesenchymal stem cells (BMSCs), osteoblast (OBs) and osteoclast (OCs) precursors were cocultured in plain and CaPn-enriched Col/Fib according to the following experimental conditions: a) HUVECs-BMSCs; b) OBs-OCs; c) HUVECs-BMSCs-OBs-OCs. Undifferentiated BMSCs were used to support HUVECs in microvascular network formation. BMSCs and peripheral blood mononuclear cells were respectively pre-differentiated into OB and OC precursors through 7 days of culture in osteogenic or osteoclastogenic medium. Needle-shaped CaPn (Ø ∼20 nm, length ∼80 nm) were added to a collagen/fibrinogen solution. Cells were resuspended in a thrombin solution and then mixed with plain or CaPn-enriched collagen/fibrinogen. The cell-laden mix was injected in U-shaped PMMA masks and let to polymerize to generate constructs of 2×2×5 mm³. Samples were cultured for 10 days. Microvascular network formation was evaluated by confocal microscopy. OB differentiation was analyzed by quantification of Alkaline Phosphatase (ALP) and cell-mediated mineralization. OC differentiation was assessed by Tartrate-Resistant Acid Phosphatase (TRAP) and cell-mediated phosphate release quantification.

HUVECs developed a robust 3D microvascular network and BMSCs differentiated into mural cells supporting vasculogenesis. The presence of CaPn enhanced OB and OC differentiation, as demonstrated by the significantly higher ALP and TRAP levels and by the superior cell-mediated mineralization and phosphate release measured in CaPn-enriched than in plain Col/Fib. The coculture of OBs and OCs with HUVECs and BMSCs further enhanced ALP and TRAP levels, indicating that the presence of HUVECs and BMSCs positively contributed to OB and OC differentiation. Remarkably, higher values of ALP and TRAP activity were measured in the tetraculture in CaPn-enriched Col/Fib compared to plain Col/Fib, indicating that also in the tetraculture the mineralized matrix stimulated OB and OC differentiation.

The 3D MiniTissue bone remodeling model developed in this study is a promising platform to investigate bone cell and endothelial cell cross-talk. This system allows to minimize the use of cells and reagents and is characterized by a superior ease of use compared to other microscale systems, such as microfluidic models. Finally, it represents a suitable platform to test drugs for bone diseases and can be easily personalized with patient-derived cells further increasing its relevance as drug screening platform.

Autologous bone grafting is a standard procedure for the clinical repair of skeletal defects, and good results have been obtained. Autologous vascularized bone grafting is currently the procedure of choice because of high osteogenic potential and resistance against reabsorption. Disadvantages of this procedure include limited availability of donor sites, clinical difficulty in handling, and a failure rate exceeding 10%. Allografts are often used for massive bone loss, but since only the marginal portion is newly vascularized after the implantation non healing fractures are often reported, along with a graft reabsorption. To overcome these problems, some studies in literature tried to conjugate bone graft and vascular supply, with encouraging results. On the other side, several studies in literature reported the ability of bone marrow derived cells to promote neo-vascularization. In fact, bone marrow contains not only hematopoietic stem cells (HSCs) and MSCs as a source for regenerating tissues but also accessory cells that support angiogenesis and vasculogenesis by producing several growth factors. In this scenario a new procedure was developed, consisting in an allogenic bone graft transplantation in a critical size defect in rabbit radius, plus a deviation at its inside of the median artery and vein with a supplement of autologous bone marrow concentrate on a collagen scaffold.

Twenty-four New Zealand male white rabbits (2500–3000 g) were divided into 2 groups, each consisting of 12 animals. Surgeries were performed as follow:

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Group 1 (#12): allogenic bone graft (left radius) / allogenic bone graft + vascular pedicle + autologous bone marrow concentrate (right radius)

For each group, 3 experimental time: 8, 4 and 2 weeks (4 animals for each time).

The bone used as graft was previously collected from an uncorrelated study. An in vitro evaluation of bone marrow concentrate was performed in all cases, and at the time of sacrifice histological and histomorphometrical assessment were performed with immunohistochemical assays for VEGF, CD31 e CD146 to highlight the presence of vessels and endothelial cells. Micro-CT Analysis with quantitative bone evaluation was performed in all cases.

The bone marrow concentrate showed a marked capability to differentiate into osteogenic, chondrogenic and agipogenic lineages. No complications such as infection or intolerance to the procedure were reported. The bone grafts showed only a partial integration, mainly at the extremities in the group with vascular and bone marrow concentrate supplement, with a good and healthy residual bone. immunohistochemistry showed an interesting higher VEGF expression in the same group. Micro CT analysis showed a higher remodeling activities in the groups treated with vascular supplement, with an area of integration at the extremities increasing with the extension of the sacrifice time.

The present study suggests that the vascular and marrow cells supplement may positively influence the neoangiogenesis and the neovascularization of the homologous bone graft. A longer time of follow up and improvement of the surgical technique are required to validate the procedure.

Aims

Chronic conditions of the wrist may be difficult to manage because pain and psychiatric conditions are correlated with abnormal function of the hand. Additionally, intra-articular inflammatory cytokines may cause pain.

We aimed to validate the measurement of inflammatory cytokines in these conditions and identify features associated with symptoms.

Aims. This retrospective cohort study compared the results of vascularised and non-vascularised anterior sliding tibial grafts for the treatment of osteoarthritis (OA)of the ankle secondary to osteonecrosis of the talus. . Patients and Methods. We reviewed the clinical and radiological outcomes of 27 patients who underwent arthrodesis with either vascularised or non-vascularised (conventional) grafts, comparing the outcomes (clinical scores, proportion with successful union and time to union) between the two groups. The clinical outcome was assessed using the Mazur and American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scores. The mean follow-up was 35 months (24 to 68). Results. The mean outcome scores increased significantly in both groups. In the vascularised graft group, the mean Mazur score improved from 36.9 to 74.6 and the mean AOFAS scale improved from 49.6 to 80.1. . In the conventional arthrodesis group, the mean Mazur score improved from 35.5 to 65 and the mean AOFAS scale from 49.2 to 67.6. . Complete fusion was achieved in 13 patients (76%) in the vascularised group, but only four (40%) in the conventional group. The clinical outcomes and proportion achieving union were significantly better in the vascularised group compared with the conventional arthrodesis group, although time to union was similar in the two groups. Take home message: Vascularised sliding tibial grafts may be used to achieve arthrodesis in patients with OA of the ankle secondary to osteonecrosis of the talus. Cite this article: Bone Joint J 2016;98-B:359–64

Vascularised fibular grafts (VFGs ) are a valuable surgical technique in limb salvage after resection of a tumour. The primary objective of this multicentre study was to assess the risk factors for failure and complications for using a VFG after resection of a tumour. . The study involved 74 consecutive patients (45 men and 29 women with mean age of 23 years (1 to 64) from four tertiary centres for orthopaedic oncology who underwent reconstruction using a VFG after resection of a tumour between 1996 and 2011. There were 52 primary and 22 secondary reconstructions. The mean follow-up was 77 months (10 to 195). . In all, 69 patients (93%) had successful limb salvage; all of these united and 65 (88%) showed hypertrophy of the graft. The mean time to union differed between those involving the upper (28 weeks; 12 to 96) and lower limbs (44 weeks; 12 to 250). Fracture occurred in 11 (15%), and nonunion in 14 (19%) patients. . In 35 patients (47%) at least one complication arose, with a greater proportion in lower limb reconstructions, non-bridging osteosynthesis, and in children. These complications resulted in revision surgery in 26 patients (35%). VFG is a successful and durable technique for reconstruction of a defect in bone after resection of a tumour, but is accompanied by a significant risk of complications, that often require revision surgery. Union was not markedly influenced by the need for chemo- or radiotherapy, but should not be expected during chemotherapy. Therefore, restricted weight-bearing within this period is advocated. Cite this article: Bone Joint J 2015;97-B:853–61

A new method of vascularised tibial grafting has been developed for the treatment of avascular necrosis (AVN) of the talus and secondary osteoarthritis (OA) of the ankle. We used 40 cadavers to identify the vascular anatomy of the distal tibia in order to establish how to elevate a vascularised tibial graft safely. Between 2008 and 2012, eight patients (three male, five female, mean age 50 years; 26 to 68) with isolated AVN of the talus and 12 patients (four male, eight female, mean age 58 years; 23 to 76) with secondary OA underwent vascularised bone grafting from the distal tibia either to revascularise the talus or for arthrodesis. The radiological and clinical outcomes were evaluated at a mean follow-up of 31 months (24 to 62). The peri-malleolar arterial arch was confirmed in the cadaveric study. A vascularised bone graft could be elevated safely using the peri-malleolar pedicle. The clinical outcomes for the group with AVN of the talus assessed with the mean Mazur ankle grading scores, improved significantly from 39 points (21 to 48) pre-operatively to 81 points (73 to 90) at the final follow-up (p = 0.01). In all eight revascularisations, bone healing was obtained without progression to talar collapse, and union was established in 11 of 12 vascularised arthrodeses at a mean follow-up of 34 months (24 to 58). MRI showed revascularisation of the talus in all patients.

We conclude that a vascularised tibial graft can be used both for revascularisation of the talus and for the arthrodesis of the ankle in patients with OA secondary to AVN of the talus.

Cite this article: Bone Joint J 2015; 97-B:802–8.

The December 2014 Oncology Roundup³⁶⁰ looks at: metaphyseal and diaphyseal osteosarcoma subtly different beasts; sports and endoprosthetic reconstruction of the knee; is curettage without tissue diagnosis sensible in cartilaginous tumours?; autoclaved autograft in bone tumour reconstruction; vascularised graft a step too far in bone defects?; interdigitated neoadjuvant chemoradiotherapy in high-grade sarcoma; predicting life expectancy in patients with painful metastasis; and osteolytic lesions of the hands and feet.

Resection of a primary sarcoma of the diaphysis of a long bone creates a large defect. The biological options for reconstruction include the use of a vascularised and non-vascularised fibular autograft. The purpose of the present study was to compare these methods of reconstruction. Between 1985 and 2007, 53 patients (26 male and 27 female) underwent biological reconstruction of a diaphyseal defect after resection of a primary sarcoma. Their mean age was 20.7 years (3.6 to 62.4). Of these, 26 (49 %) had a vascularised and 27 (51 %) a non-vascularised fibular autograft. Either method could have been used for any patient in the study. The mean follow-up was 52 months (12 to 259). Oncological, surgical and functional outcome were evaluated. Kaplan–Meier analysis was performed for graft survival with major complication as the end point. At final follow-up, eight patients had died of disease. Primary union was achieved in 40 patients (75%); 22 (42%) with a vascularised fibular autograft and 18 (34%) a non-vascularised (p = 0.167). A total of 32 patients (60%) required revision surgery. Kaplan–Meier analysis revealed a mean survival without complication of 36 months (0.06 to 107.3, . sd. 9) for the vascularised group and 88 months (0.33 to 163.9, . sd. 16) for the non-vascularised group (p = 0.035). . Both groups seem to be reliable biological methods of reconstructing a diaphyseal bone defect. Vascularised autografts require more revisions mainly due to problems with wound healing in distal sites of tumour, such as the foot. Cite this article: Bone Joint J 2014;96-B:1258–63

This preliminary study evaluates a combination of bone morphogenetic protein (BMP)-7 and non-vascularised autologous fibular grafting (AFG) for the treatment of osteonecrosis of the femoral head.

BMP-7/AFG combination was applied in seven pre-collapse femoral heads (five Steinberg stage II, two stage III) in six patients. Pre- and post-operative evaluation included clinical (Harris hip score (HHS), visual analogue scale (VAS) for pain) and radiological assessment (radiographs, quantitative CT) at a mean follow-up of 4 years (2 to 5.5).

A marked improvement of function (mean HHS increase of 49.2) and decrease of pain level (mean VAS decrease of 5) as well as retention of the sphericity of the femoral head was noted in five hips at the latest follow-up, while signs of consolidation were apparent from the third post-operative month. One patient (two hips) required bilateral total hip replacement at one year post-operatively. In the series as a whole, quantitative-CT evaluation revealed similar densities between affected and normal bone. Heterotopic ossification was observed in four hips, without compromise of the clinical outcome.

In this limited series AFG/BMP-7 combination proved a safe and effective method for the treatment of femoral head osteonecrosis, leading to early consolidation of the AFG and preventing collapse in five of seven hips, while the operative time and post-operative rehabilitation period were much shorter compared with free vascularised fibular grafts.

Cite this article: Bone Joint J 2014;96-B:31–5.

Congenital pseudarthrosis of the tibia (CPT) is a rare but well recognised condition. Obtaining union of the pseudarthrosis in these children is often difficult and may require several surgical procedures. The treatment has changed significantly since the review by Hardinge in 1972, but controversies continue as to the best form of surgical treatment. This paper reviews these controversies.

Cite this article: Bone Joint J 2013;95-B:1027–34.

The June 2013 Hip & Pelvis Roundup³⁶⁰ looks at: failure in metal-on-metal arthroplasty; minimal hip approaches; whether bisphosphonates improve femoral bone stock following arthroplasty; whether more fat means more operative time; surgical infection; vascularised fibular graft for osteonecrosis; subclinical SUFE; and dentists, hips and antibiotics.

Purpose. We retrospectively evaluated the outcome of fibula grafts in upper limb post infectious diaphyseal gap nonunions and assessed the following modifiers: age, site, vascularised/ nonvascularised, and length of the graft on time to union, graft incorporation, complication rate and reoperation rate. Methods. Thirty seven paediatric upper limb segmental defects treated over a period of 10 years were identified. Twenty two post septic defects in 21 children were treated with intramedullary fixation and vascularised/ nonvascularised fibula grafting. Union time was assessed from records and radiographs. Graft incorporation was assessed using Pixel value ratio (Hazra et al). Complications were defined as nonunion, delayed union, implant failure, refractures, graft loss and infection. Results. Twenty one children with 22 nonunions, 9 boys and 12 girls, mean age 6.5 years were followed up for a mean of 24 months. Defects (humerus-8, radius-8, ulna-6) ranged from 10 mm to 85 mm before surgery. Seven vascularised grafts(mean length = 69.9 mm) 3 in ulna and 4 in radius and 14 nonvascularised (48.8 mm) were 8 in humerus, 4 in radius, 3 in ulna. Primary union was 81% at a mean of 4.7 months. Mean pixel value for graft incorporation was 1.3 (SD = 0.2) on immediate postoperative radiograph and 1.08 (SD 0.16) at mean of 2 years. Complications included nonunion requiring surgery in 4, delayed union in 6, wire migration in 6, refractures in 4, infection reactivation in 2 with loss of graft in 1. Time to union was 5.5 (SD 2.9) months in nonvascularised and 3.1 (SD 0.6) in vascualrised group (P = 0.04). Complication rate was 1.2 and 0.2 in nonvascularised and vascularised grafts(p = 0.04). Bone, age and the graft length did not significantly affect union time, graft incorporation, complication and reoperation rate. The complication rate was significantly higher in children ≤8 year; however other outcomes were not significantly different. Conclusion. Vascularised grafts and children aged >8 year did significantly better in fibular grafting for post-septic upper limb diaphyseal nonunions

Infected non-union after severe open fracture or unsuitable fracture operation is frequently associated with bone defect and its treatment has been controversial. We have used microsurgical vascularised composite graft for these problematic cases. Fifty one patients aged 17∼70 year old (43.6 years old in average), including 41 men and 10 women. Follow-up has been more than 6 months. The vascularised composite graft included a free fibular osteocutaneous flap in 41 cases, a vascular pedicled fibular osteocutaneous flap in 2 cases, a free iliac osteocutaneous flap in 5 cases, a vascularised cutaneous flap in 2 cases and other in one case. All infected non-unions were united without trouble and co-existing infection was successfully eradicated. This method also enables the patients rapid bone union and subsequent early functional recovery. This success was attributed to greater transport of oxygen and good antibiotic perfusion in presence of good blood supply. We conclude that microsurgical vascularised composite graft for infected non-union is an extremely useful method with early bone union and subsidence of infection.

The October 2012 Oncology Roundup³⁶⁰ looks at: the causes of primary bone tumours; adjuvant chemotherapy in the longer term; vascularised fibular grafts to salvage massive femoral allografts; a new look at old risks; reconstruction with excised irradiated bone; predicting chemosensitivity in osteosarcoma ; and chemotherapy, osteoporosis and the risk of fracture.

Aims

The objective of our study is to identify the causes for recurrence and to evaluate the results of our technique.