Aims: Purpose of this study was to evaluate the results of a staged revision technique in the treatment of deep infection after limb salvage surgery for bone tumors and to identify factors possibly affecting the outcome. Methods: A retrospective study of 19 consecutive patients with an infected bone tumor reconstruction treated at our Institution in the period 1986–1997 was undertaken. All the patients underwent staged revision (two stages in 13 cases, three stages in 5, four stages in 1) using one or more antibiotic loaded cement spacers after debridement and partial (10 cases) or complete (9 cases) removal of the original implant. Postoperatively, all the patients received oral or parenteral antibiotics for a minimum of 4 weeks. Delayed reimplantation was performed in 15 cases, average time to reimplantation being 7 months (4–14). A minimum follow up of 3 years was available in all patients. Cultures identiþed S. Epider-midis in 12 cases (63%), S. Aureus in 4 (21%), mixed organisms in 2 (11%), and were negative in 1 case (5%) despite clinical evidence of infection. Results: At a minimum follow-up of 3 years, 13 patients were continuously infection-free (68%) while 6 relapsed (32%). Two of the 6 relapses were cleared by amputation while 4 remained infected. Average functional result of infection-free patients according to the International Society Of Limb Salvage (ISOLS) was 71% (21.2 points), ranging from 60% to 80% (18 to 24 points). Conclusions: Staged revision with antibiotic loaded cement spacer for infected bone tumor reconstruction is a demanding and expensive technique requiring prolonged inability. Overall success rate in this series approaches 70%. Complete removal of the infected implant, microbiology, appropriate antibiotic selection, and negative cultures before reimplantation are crucial

We aim to establish the likely functional scores following different types of surgery for bone tumours. All living patients who had undergone treatment for a bone tumour were contacted and invited to complete a TESS self-report questionnaire. The TESS contains 32 items of day-to-day activities which the patient scores themselves against. The final score is a percentage, with 100% being ‘normal’. The project was approved by the local ethical committee.

723 responses were obtained from just over 1000 letters that were sent. Thirty seven sets of data were incomplete leaving a total of 686. There were 369 males and 317 females, with an average age of 49 (range 15 to 93). The mean interval from their initial operation was 12 years (range 1 to 42). 590 of the procedures were in the lower limb and 96 in the upper limb. 126 patients had an amputation and 560 limb salvage (82%).

Mean scores obtained for each procedure were: EPR mid-femur 86%; EPR distal femur 77%; EPR proximal tibia 74%; EPR proximal humerus 71%; EPR proximal femur 71%; Below knee amputation 70%; EPR total femur 63%; Disarticulation of the hip 61%; Above knee amputation 60%; Hindquarter amputation 57%; EPR pelvis 54%.

Younger patients had much better scores (80% for those under 30 vs. 69% for those over 30, p< 0.0001) than those over 30. Additionally, the scores for those that had had an amputation following a EPR procedure were no worse than those who had had an amputation originally. Significantly, EPR proximal tibia was better than AKA (78% vs. 67% p = 0.0003), as was EPR distal femur (80% vs. 67% p < 0.0001).

This data from a large series is helpful in indicating likely outcomes following surgical treatment of sarcomas, both for patients and surgeons.

In recent years, some attempts have been made to develop a method that generates finite element (FE) models of the femur and pelvis using CT. However, due to the complex bone geometry, most of these methods require an excessive amount of CT radiation dosage. Here we describe a method for generating accurate patient-specific FE models of the total hip using a small number of CT scans in order to reduce radiation exposure.

A previously reported method for autogenerating patient-specific FE models of the femur was extended to include the pelvis. CT osteodensitometry was performed on 3 patients who had hip replacement surgery and patient-specific FE models of the total hip were generated. The pelvis was generated with a new technique that incorporated a mesh morphing method called ‘host mesh fitting’. It used an existing generic mesh and then morphed it to reflect the patient specific geometry. This can be used to morph the whole pelvis, but our patient dataset was limited to the acetabulum. An algorithm was developed that automated all the procedures involved in the fitting process.

Average error between the fitted mesh and patient specific data sets for the femur was less than 1mm. The error for the pelvis was about 2.5mm. This was when a total 18 CT scans with 10mm gap were used – 12 of the femur, and 6 of the pelvis. There was no element distortion and a smooth element surface was achieved.

Previously, we reported a new method for automatically generating a FE model of the femur with as few CT scans as possible. Here we describe a technique that customizes a generic pelvis mesh to patient-specific data sets. Thus we have developed a novel hybrid technique which can generate an accurate FE model of the total hip using significantly less CT scans.

An automated method of generating FE models for the total hip with reduced CT radiation exposure will be a valuable clinical tool for surgeons.

In recent years, some attempts have been made to develop a method that generates finite element (FE) models of the femur and pelvis using CT. However, due to the complex bone geometry, most of these methods require an excessive amount of CT radiation dosage. Here we describe a method for generating accurate patient-specific FE models of the total hip using a small number of CT scans in order to reduce radiation exposure.

A previously reported method for autogenerating patient-specific FE models of the femur was extended to include the pelvis. CT osteodensitometry was performed on 3 patients who had hip replacement surgery and patient-specific FE models of the total hip were generated. The pelvis was generated with a new technique that incorporated a mesh morphing method called ‘host mesh fitting’. It used an existing generic mesh and then morphed it to reflect the patient specific geometry. This can be used to morph the whole pelvis, but our patient dataset was limited to the acetabulum. An algorithm was developed that automated all the procedures involved in the fitting process.

Average error between the fitted mesh and patient specific data sets for the femur was less than 1mm. The error for the pelvis was about 2.5mm. This was when a total 18 CT scans with 10mm gap were used – 12 of the femur, and 6 of the pelvis. There was no element distortion and a smooth element surface was achieved.

Previously, we reported a new method for automatically generating a FE model of the femur with as few CT scans as possible. Here we describe a technique that customizes a generic pelvis mesh to patient-specific data sets. Thus we have developed a novel hybrid technique which can generate an accurate FE model of the total hip using significantly less CT scans.

Introduction: Allograft-Prosthesis Composite represents a reliable option for proximal femur replacement after resection for bone tumor. It provides advantages over megaprostheses because of better soft tissue repair and superior abduction strength, quality of gait, hip stability, and load transfer by healed bone rather than prosthetic stem, with potential impact on implant survival. Purpose of this paper was to review details of the surgical technique and results.

Methods: A retrospective study of 62 patients who had resection of the proximal femur because of a bone tumor and reconstruction with an Allograft-Prosthesis Composite was undertaken. The basic surgical technique consisted of an uncemented tapered long stem prosthesis (i.e. Wagner or Wagner-type stem) cemented in the allograft and press-fitted in the host bone, achieving bone-bone contact through a transverse osteotomy. Details of the surgical technique included: 1) accurate preoperative planning, canal sizing and implant selection; 2) under-reaming of the proximal 5–10 mm of the host medullary canal, depending upon bone quality and diameter of the selected stem; 3) allograft preparation and prosthesis cementation in the allograft; 4) introduction of the composite implant, pressfitted in host medullary canal, until bone-bone contact is achieved; 5) careful repair of abductors and iliopsoas to corresponding allograft tendon insertions.

Key points for successful fixation are absolute rotational stability and satisfactory circumferential bone-bone contact at the time of surgery.

Postoperative regimen consisted of hip, followed by progressive bracing and toe-touch weight-bearing for 6 weeks, weight-bearing.

Results: There were 2 septic failures. Two patients developed asymptomatic nonunion. There were no dislocations. Most common complication was fracture of the allograft greater trochanter (30%), which required surgery in only 1 case and never substantially affected function. The incidence of trochanteric fracture decreased from 63% in the first 27 patients to 5% in the following 35 patients by switching implant design from a valgus 145° neck angle to 135° neck angle, improving offset and abductors function. Bone grafting of the allograft-host union was required in 10% of the cases.

According to MSTS, results were satisfactory in 90% of the patients, with average score 91% (75%–96%).

Discussion and Conclusion: Allograft-Prosthesis Composite is a successful procedure for reconstruction of the proximal femur. Careful surgical technique is the key to excellent function and low complication rate.

Purpose: Intra-op localisation of small nidus in Osteiod osteoma and Osteoblastomas is often difficult resulting in failed excision with persistent pain. We report two year follow-up results of the efficacy and reliability of using an intra-operative gamma probe in conjunction with fluoros-copy to aid resection in primary and revision surgeries.

Method: Eight patients (6M; 2F) with a diagnosis of osteoid osteoma (7) and osteoblastoma (1) were seen at our centre. The mean age at presentation was 20.9 years (9–31y). The tumour was localised to cervical (2), thoracic(4) and lumbar (2) posterior elements. All had back or neck pain of varying duration with a mean of 20 months (6–48mo). Three patients had failed treatments including CT-guided radiofrequency ablation in one and surgical excision under fluoroscopy in two. No case had previously utilised an intra-op gamma probe for localisation. All patients had work-up with plain X-rays, CT, MRI and 99 m Technetium bone scan to identify and localise the lesion. A pre-requisite for use of intra-op gamma probe was a positive pre-op bone scan. On the day of surgery, 600 MBq Tech HMDP (hydroxy-methylene-di-phosphate) was administered IV 3 hours prior to surgery. Fluoroscopy was used to confirm anatomical level, permanent mark made on skin and area exposed surgically. A 5 mm cadmium telluride (Cd Te) probe (which converts gamma radiation into electrical signal) and rate meter were used to scan the area containing lesion and counts per second(cps) recorded. The tumour nidus was then excised and cps from tumour bed and excised specimen recorded.

Results: The mean follow-up was 5.85 years (2–12.3y). The mean cps for osteoid osteoma pre-excision was 203.8 (60–515), which fell to 72.5 (10–220) post-excision. The cps reduced from 373 to 40.5 post-operatively for Osteoblastoma. Complete excision was recorded every time and all patients reported characteristic disappearance of pre-operative pain. All had discontinued analgesic medication and returned to normal activity by three months. All patients were followed-up regularly when they filled NDI, ODI and SF-36.

Conclusion: Gamma probe guided surgical excision facilitates accurate localisation of lesion, is less invasive and most importantly confirmation of complete excision of the tumour nidus consistently every time.

Aim. Local antibiotics released through a carrier is a commonly used technique to prevent infection in orthopaedic procedures. An interesting carrier in aseptic bone reconstructive surgery are bone chips impregnated with AB solution. Systemically administered Cefazolin (CFZ) is used for surgical site infection prophylaxis however in vitro study showed that fresh frozen and processed bone chips impregnated with CFZ solution completely release the CFZ within a few hours. On the other hand irradiated freeze-dried bone chips, treated with supercritical CO2 (scCO2) have been shown to be an efficient carrier for the antibiotics vancomycine or tobramycine. With this pilot study we wanted to investigate if CFZ solution impregnation of bone chips treated with scCO2 shows a more favorable release pattern of CFZ. Method. The bone chips were prepared using the standard scCO2 protocol and were impregnated with 100 mg/ml cefazolin at different timepoints during the process: before freeze drying (BC type A), after freeze drying (BC type B) and after gamma-irradiation. 0.5g of the impregnated bone grafts were incubated with 5ml of fetal calf serum (FCS) at 37°C. At 2, 4, 6, 8 and 24h of incubation 200µl of eluate was taken for analysis. After 24h the remaining FCS was removed, bone grafts were washed and new FCS (5ml) was added. Consecutive eluate samples were taken at 48, 72 and 96h of incubation. The concentration of CFZ in the eluates was measured with the validated UPLC-DAD method. Analysis was performed in triplicate. Results. The mean concentration of CFZ in the eluate obtained from BC type A incubated for 2h was higher compared to BC type B, respectively 581 mg/l and 297 mg/l. However, the elution profile is the same for both types: the CFZ concentration in the eluates drops within the first 24h from 581 mg/l to 365 mg/l (37%) for BC type A and from 297 mg/l to 132 mg/l (56%) for BC type B. After 24h no further significant CFZ release is seen. Impregnation of the bone chips before or after gamma irradiation did not affect this elution profile. Conclusions. Bone chips treated with scCO2 show a comparable elution pattern compared to non-scCO2 treated bone chips. AB release depends on the properties of the AB, making it impossible to copy the same impregnation protocol for different antibiotics. The stability of CFZ in solution at 37°C and its release are a major concern when establishing an impregnation protocol with CFZ

To analyze the effect of tooth extraction site preservation on bone mineral density 6 months after surgery. From 2020 to 2021, two adjacent teeth (37, 38) of the same patient were extracted at the same time, and then 37 were selected for site preservation, implanted with Bio-oss bone powder, covered with double Bio-gide membrane, reduce tension and sutured. After 6 months of self-healing, 38 was taken CBCT, and the gray value measurement tool in the software was used to measure the bone mineral density of 37 bone graft areas and 38 extraction sockets. Bone density was high in the center of the bone graft area after the extraction site, and the density decreased in the adjacent alveolar socket, but the gray value was still higher than 38 for natural healing. Extraction site surgery can improve bone mass and quality at the extraction site. It is good for implanting

Introduction. Fibrous dysplasia is a pathological condition, where normal medullary bone is replaced by fibrous tissue and small, woven specules of bone. Fibrous dysplasia can occur in epiphysis, metaphysis or diaphysis. Occationally, biopsy is necessary to establish the diagnosis. We present a review of operative treatment using the Ilizarov technique. The management of tibial fibrous dysplasia in children are curettage or subperiosteal resection to extra periosteal wide resection followed by bone transport. Materials and Methods. A total of 18 patients were treated between 2010 – 2020; 12 patients came with pain and 6 with pain and deformity. All patients were treated by Ilizarov technique. Age ranges from 4–14 years. 12 patients by enbloc excision and bone transportation and 6 patients were treated by osteotomy at the true apex of the deformity by introducing the k/wires in the medullary cavity with stable fixation by Ilizarov device. The longest duration for bone transport was 16 weeks (14–20 weeks) for application, after deformity correction was 20 weeks. We have never used any kind of bone grafts. Results. All the 18 patients were treated successfully by Ilizarov compression distraction device. The patients with localized tibial pathology with deformity had the shortest period on the Ilizarov apparatus, 14 weeks. Conclusions. Preservation and bone regeneration by distraction histogenesis constitutes a highly conservative limb saving surgery. Patients with bone defects of <10 cm, a great deal of preserved healthy tissue and good prognosis are good candidates for these methods

Segmental bone transport (SBT) using an external fixator is currently a standard treatment for large-diameter bone defects at the donor site with low morbidity. However, long-term application of the device is needed for bone healing. In addition, patients who received SBT treatment sometimes fail to show bone repair and union at the docking site, and require secondary surgery. The objective of this study was to investigate whether a single injection of recombinant human bone morphogenetic protein 2 (rhBMP-2)-loaded artificial collagen-like peptide gel (rhBMP-2/ACG) accelerates consolidation and bone union at the docking site in a mouse SBT model. Six-month-old C57BL/6J mice were reconstructed by SBT with external fixator that has transport unit, and a 2.0-mm bone defect was created in the right femur. Mice were divided randomly into four treatment groups with eight mice in each group, Group CONT (immobile control), Group 0.2mm/d, Group 1.0mm/d, and Group BMP-2. Mice in Group 0.2mm/d and 1.0mm/d, bone segment was moved 0.2 mm per day for 10 days and 1.0 mm per day for 2 days, respectively. Mice in Group BMP-2 received an injection of 2.0 μg of rhBMP-2 dissolved in ACG into the bone defect site immediately after the defect-creating surgery and the bone segment was moved 1.0 mm/day for 2 days. All animals were sacrificed at eight weeks after surgery. Consolidation at bone defect site and bone union at docking site were evaluated radiologically and histologically. At the bone defect site, seven of eight mice in Group 0.2mm/d and two of eight mice in Group 1.0mm/d showed bone union. In contrast, all mice in Group CONT showed non-union at the bone defect site. At the docking site, four of eight mice in Group 0.2 mm/d and three of eight mice in Group 1.0 mm/d showed non-union. Meanwhile, all mice in Group BMP-2 showed bone union at the bone defect and docking sites. Bone volume and bone mineral content were significantly higher in Group 0.2mm/d and Group BMP-2 than in Group CONT. HE staining of tissue from Group 0.2mm/d and Group BMP-2 showed large amounts of longitudinal trabecular bone and regenerative new bone at eight weeks after surgery at the bone defect site. Meanwhile, in Group CONT and Group 1.0mm/d, maturation of regenerative bone at the bone defect site was poor. Differences between groups were analyzed using one-way ANOVA and a subsequent Bonferroni's post-hoc comparisons test. P < 0.05 was considered significant. rhBMP-2/ACG combined with SBT may be effective for enhancing bone healing in large bone defects without the need for secondary procedures

Aims

While internet search engines have been the primary information source for patients’ questions, artificial intelligence large language models like ChatGPT are trending towards becoming the new primary source. The purpose of this study was to determine if ChatGPT can answer patient questions about total hip (THA) and knee arthroplasty (TKA) with consistent accuracy, comprehensiveness, and easy readability.

Aims

This study examined whether systemic administration of melatonin would have different effects on osseointegration in ovariectomized (OVX) rats, depending on whether this was administered during the day or night.

Aims

Research on hip biomechanics has analyzed femoroacetabular contact pressures and forces in distinct hip conditions, with different procedures, and used diverse loading and testing conditions. The aim of this scoping review was to identify and summarize the available evidence in the literature for hip contact pressures and force in cadaver and in vivo studies, and how joint loading, labral status, and femoral and acetabular morphology can affect these biomechanical parameters.

Aims

The risk of postoperative complications after resection of soft-tissue sarcoma in the medial thigh is higher than in other locations. This study investigated whether a vessel sealing system (VSS) could help reduce the risk of postoperative complications after wide resection of soft-tissue sarcoma in the medial thigh.

Aims

Open lower limb fracture is a life-changing injury affecting 11.5 per 100,000 adults each year, and causes significant morbidity and resource demand on trauma infrastructures. This study aims to identify what, and how, outcomes have been reported for people following open lower limb fracture over ten years.

Aims

To evaluate mid-to long-term patient-reported outcome measures (PROMs) of endoprosthetic reconstruction after resection of malignant tumours arising around the knee, and to investigate the risk factors for unfavourable PROMs.

Aims

The purpose of this study was to compare reoperation and revision rates of double plating (DP), single plating using a lateral locking plate (SP), or distal femoral arthroplasty (DFA) for the treatment of periprosthetic distal femur fractures (PDFFs).

Introduction and Objective. Senescent bone cell overburden accelerates osteoporosis. Epigenetic alteration, including microRNA signalling and DND methylation, is one of prominent features of cellular senescence. This study aimed to investigate what role microRNA-29a signalling may play in the development of senile osteoporosis. Materials and Methods. Bone biopsy and serum were harvested from 13 young patients and 15 senior patients who required spine surgery. Bone mass, microstructure, and biomechanics of miR-29a knockout mice (miR-29aKO) and miR-29a transgenic mice (miR-29aTg) were probed using mCT imaging and three-point bending material test. Senescent cells were probed using senescence-associated b-galactosidase (SA-b-gal) staining. Transcriptomic landscapes of osteoblasts were characterized using whole genome microarray and KEGG bioinformatics. miR-29a and senescence markers p16. INK4a. , p21. Waf/cipl. and inflammatory cytokines were quantified using RT-PCR. DNA methylome was probed using methylation-specific PCR and 5-methylcytosine immunoblotting. Results. Senescent osteoblast overburden, DNA hypermethylation and oxidative damage together with significant decreases in serum miR-29a levels were present in bone specimens of aged patients. miR-29aKO mice showed a phenotype of skeletal underdevelopment, low bone mineral density and weak biomechanics. miR-29a knockout worsened age-induced bone mass and microstructure deterioration. Of note, aged miR-29aTg mice showed less bone loss and fatty marrow than aged wild-type mice. Transgenic overexpression of miR-29s compromised age-dysregulated osteogenic differentiation capacity of bone-marrow mesenchymal cells. In vitro, miR-29a promoted transcriptomic landscapes of antioxidant proteins in osteoblasts. The microRNA interrupted DNA methyltransferase (Dnmt3b)-mediated DNA methylation, inhibiting reactive oxygen radicals burst, IL-6 and RANKL production, and a plethora of senescent activity, including increased p16. INK4a. , p21. Waf/cipl. signalling and SA-b-gal activity. Conclusions. miR-29a loss is correlated with human age-mediated osteoporosis. miR-29a signalling is indispensable in bone mase homeostasis and microstructure integrity. Gain of miR-29a function is advantageous to delay age-induced bone loss through promoting antioxidant proteins to inhibit DNA hypermethylation-mediated osteoblast senescence. Collective investigations shine light onto the anabolic effects miR-29a signalling to bone integrity and highlight a new epigenetic protection strategy through controlling microRNA signalling to delay osteoblast senescence and senile osteoporosis development

Patients undergoing revision surgery of a primary total hip arthroplasty often exhibit bone loss and poor bone quality, which make achieving stable fixation and osseointegration challenging. Implant components coated in porous metals are used clinically to improve mechanical stability and encourage bone in-growth. We compared ultra-porous titanium coatings, known commercially as Gription and Porocoat, in an intra-articular model by press-fitting coated cylindrical implants into ovine femoral condyles and evaluating bone in-growth and fixation strength 4, 8 and 16 weeks post-operatively. Bilateral surgery using a mini-arthrotomy approach was performed on twenty-four Dorset-Rideau Arcott rams (3.4 ± 0.8 years old, 84.8 ± 9.3 kg) with Institutional Animal Care Committee approval in accordance with the Canadian Council on Animal Care. Cylindrical implants, 6.2 mm in diameter by 10 mm in length with surface radius of curvature of 35 mm, were composed of a titanium substrate coated in either Porocoat or Gription and press-fit into 6 mm diameter recipient holes in the weight-bearing regions of the medial (MFC) and lateral (LFC) femoral condyles. Each sheep received 4 implants; two Gription in one stifle (knee) and two Porocoat in the contralateral joint. Biomechanical push-out tests (Instron ElectroPuls E10000) were performed on LFCs, where implants were pushed out relative to the condyle at a rate of 2 mm/min. Force and displacement data were used to calculate force and displacement at failure, stiffness, energy, stress, strain, elastic modulus, and toughness. MFCs were fixed in 70% ethanol, processed undecalcified, and polished sections, approximately 70 µm thick (Exakt Micro Grinding system) were carbon-coated. Backscattered electron images were collected on a scanning electron microscope (Hitachi SU3500) at 5 kV and working distance of 5 mm. Bone in-growth within the porous coating was quantified using software (ImageJ). Statistical comparisons were made using a two-way ANOVA and Fisher's LSD post-hoc test (Statistica v.8). Biomechanical evaluation of the bone-implant interface revealed that by 16 weeks, Gription-coated implants exhibited higher force (2455±1362 N vs. 1002±1466 N, p=0.046) and stress (12.60±6.99 MPa vs. 5.14±7.53 MPa, p=0.046) at failure, and trended towards higher stiffness (11510±7645 N/mm vs. 5010±8374 N/mm, p=.061) and modulus of elasticity (591±392 MPa vs. 256±431 MPa, p=0.61). Similarly, by 16 weeks, bone in-growth in Gription-coated implants was approximately double that measured in Porocoat (6.73±3.86 % vs. 3.22±1.52 %, p=0.045). No statistically significant differences were detected at either 4 nor 8 weeks, however, qualitative observations of the exposed bone-implant interface, made following push-out testing, showed more bony material consistently adhered to Gription compared to Porocoat at all three time points. High variability is attributed to implant placement, resulting from the small visual window afforded during surgery, unique curvatures of the condyles, and presence of the extensor digitorum longus tendon which limited access to the LFC. Ultra-porous titanium coatings, know commercially as Gription and Porocoat, were compared for the first time in a challenging intra-articular ovine model. Gription provided superior fixation strength and bone in-growth, suggesting it may be beneficial in hip replacement surgeries where bone stock quality and quantity may be compromised

Aims

We aimed to evaluate the utility of ⁶⁸Ga-citrate positron emission tomography (PET)/CT in the differentiation of periprosthetic joint infection (PJI) and aseptic loosening (AL), and compare it with ^99mTc-methylene bisphosphonates (^99mTc-MDP) bone scan.