Periacetabular Tumour Resection under Anterosuperior Iliac Spine Allows Better Alloprosthetic Reconstruction than Above: Bone Contact Matters

Periacetabular resections are more affected by late complications than other pelvic resections. Reconstruction using bone allograft is considered a suitable solution. However, it is still not clear how the bone-allograft contact surface impacts on mechanical and functional outcome

Custom Reconstruction Around the Knee

With rapid prototyping technique, an individual-based solution can be performed on the patient anatomy and his clinical needs. Different products can be obtained starting from custom-made prostheses and specifc instruments. 3D printing allows to design an architecture with similar mechanical characteristic of bone [8], able to induce osteointegration and decrease the stress-shielding phenomenon due to the porosity and the elasticity of trabecular titanium [9]. Moreover, rapid prototyping can be used to develop specifc instruments for each single step, minimizing the approach and bone loss, reducing the time of surgery and improving the reconstruction. The aim of our research is to develop a new customized implant for knee repair to treat wide defects that alternatively may require commercial implants such as UKA, TKA, modular prostheses or massive allograft transplantation. The idea is an hybrid prosthesis composed by a metallic frame with poly-caprolactone (PCL), a biodegradable material on the joint surface that be considered as a scaffold with similar mechanical characteristic of the implant itself in the short term, but potentially able to be substituted from the regenerative activity of the patient during time confguring a sort of biological prosthesis. This procedure allows to preserve the most bone stock possible, respecting the stability given by soft tissue (ligaments) and maintaining the articular surface on the opposit

A Pelvic Reconstruction Procedure for Custom-Made Prosthesis Design of Bone Tumor Surgical Treatments

In orthopaedic oncology, limb salvage procedures are becoming more frequent thanks to recent major improvements in medical imaging, biomechanical modelling and additive manufacturing. For the pelvis, surgical reconstruction with metal implants after tumor resection remains challenging, because of the complex anatomical structures involved. The aim of the present work is to define a consistent overall procedure to guide surgeons and bioengineers for proper implant design. All relevant steps from medical imaging to an accurate 3D anatomical-based model are here reported. In detail, the anatomical 3D models include bone shapes from CT on the entire pelvic bone, i.e., including both affected and unaffected sides, and position and extension of the tumor and soft tissues from MRI on the affected side. These models are then registered in space, and an initial shape of the personalized implant for the affected side can be properly designed and dimensioned based on the information from the unaffected side. This reported procedure can be fundamental also for virtual pre-surgical planning, and the design of patient-specific cutting guides, which would result is a safe margin for tumor cut. The entire procedure is here shown by describing the results in a single real case

Minimally invasive treatment of long bone non-unions with bone marrow concentrate, demineralized bone matrix and platelet-rich fibrin in 38 patients

To determine the efficacy of percutaneous injection of autologous bone marrow concentrated (BMC), demineralized bone matrix (DBM), and platelet rich fibrin (PRF) in the treatment of long bone non-unions. From January 2011 to January 2018 patients with non-union of the lower limbs who were on the waiting list for open grafting with established tibial or femoral non-union and minimal deformity were eligible to participate in this study. Patients were treated with a single percutaneous injection of DBM, BMC and PRF. Our study group comprised 38 patients (26 males and 12 females; mean age 39, range 18 to 65). Non-unions were located in the femur (18 cases) and in the tibia (20 cases). Clinical and imaging follow-up ranged from 4 to 60 months (mean 20 months). Bone union occurred in 30 out of 38 patients (79%) in an average of 7 months (range 3 to 12) and all healed patients had full weight bearing after 9 months on average (range 6 to 12) from injection. In 19 cases the osteosynthesis was removed 12 months on average (range 3 to 36) from surgery. One patient developed infection at the non-union site after treatment. Percutaneous injection of DBM, BMC, and PRF is an effective treatment for long-bone non-unions. This technique allows the bone to heal with a minimally invasive approach and with a hospitalization of 2 days. Key elements of bone regeneration consist of a combination of biological and biomechanical therapeutic approach

Changes of Bone Turnover Markers in Long Bone Nonunions Treated with a Regenerative Approach

International audienceIn this clinical trial, we investigated if biochemical bone turnover markers (BTM) changed according to the progression of bone healing induced by autologous expanded MSC combined with a biphasic calcium phosphate in patients with delayed union or nonunion of long bone fractures. Bone formation markers, bone resorption markers, and osteoclast regulatory proteins were measured by enzymatic immunoassay before surgery and after 6, 12, and 24 weeks. A satisfactory bone healing was obtained in 23 out of 24 patients. Nine subjects reached a good consolidation already at 12 weeks, and they were considered as the " early consolidation " group. We found that bone-specific alkaline phosphatase (BAP), C-terminal propeptide of type I procollagen (PICP), and beta crosslaps collagen (CTX) changed after the regenerative treatment, BAP and CTX correlated to the imaging results collected at 12 and 24 weeks, and BAP variation along the healing course differed in patients who had an " early consolidation. " A remarkable decrease in BAP and PICP was observed at all time points in a single patient who experienced a treatment failure, but the predictive value of BTM changes cannot be determined. Our findings suggest that BTM are promising tools for monitoring cell therapy efficacy in bone nonunions, but studies with larger patient numbers are required to confirm these preliminary results

Conservative versus surgical treatment of osteogenesis imperfecta: a retrospective analysis of 29 patients

The aim of our study was to compare the surgical and conservative treatment of patients affected by fragility fractures and deformities of long bones in osteogenesis imperfecta (OI). Our series consisted of 29 consecutive OI patients treated at our Institute. The series comprised 14 females and 15 males of different ages. The mean age at the time of the first treatment was 8 years (median 6 years; SD ± 15; range 1 to 75). The mean follow-up was 88 months. The Sillence classification was used to classify OI. Fifteen patients were classified as Type I; five as Type III and nine as Type IV. A total number of 245 procedures were recorded. Of these, 147 were surgical (pinning; intramedullary nailing and plating) while 98 were conservative (cast, braces and bandages). Bisphosphonate use was a major variable in the study. Clinical charts and radiographic films were analyzed for complications (delayed union, nonunion, malunion, hardware loosening). We recorded 58 complications: 13 in Type I; 28 in Type III and 17 in Type IV OI. The rate of each complication was: 15/245 nonunions (6.1%), 14/245 delayed unions (5.7%), 14/245 malunions (5.7%) and 15/245 hardware loosenings (6.1%). We found no statistically significant differences between surgical and conservative treatments. Type III OI, which is a very crippling form of the disease, was associated with radiographically poorer results than the other types. In our analysis, the two groups were unbalanced and only five patients were treated with bisphosphonates. Nevertheless, bisphosphonate use can be considered a good adjuvant to both the conservative and surgical treatment of OI in order to reduce the rate of complication

Renal Thrombotic Microangiopathy in Concurrent COVID-19 Vaccination and Infection

We report on the development of nephrotic proteinuria and microhematuria, with histological features of renal thrombotic microangiopathy (TMA), following the first dose of BNT162b2 COVID-19 vaccine (Pfizer-BioNTech) and COVID-19 diagnosis. A 35-year-old previously healthy man was admitted at our hospital due to the onset of foamy urine. Previously, 40 days earlier, he had received the first injection of the vaccine, and 33 days earlier, the RT-PCR for SARS-CoV-2 tested positive. Laboratory tests showed nephrotic proteinuria (7.9 gr/day), microhematuria, serum creatinine 0.91 mg/dL. Kidney biopsy revealed ultrastructural evidence of severe endothelial cell injury suggestive of a starting phase of TMA. After high-dose steroid treatment administration, complete remission of proteinuria was achieved in a few weeks. The association of COVID-19 with renal TMA has been previously described only in patients with acute renal injury. Besides, the correlation with COVID-19 vaccine has not been reported so far. The close temporal proximity (7 days) between the two events opens the question whether the histological findings should be ascribed to COVID-19 itself or to vaccine injection