Endoprosthetic reconstruction following distal femur tumour resection has been widely advocated. In this paper, we present the design of an uncemented endoprosthesis system featuring a short, curved stem, with the goal of enhancing long-term survivorship and functional outcomes. This study involved patients who underwent implantation of an uncemented distal femoral endoprosthesis with a short and curved stem between 2014 and 2019. Functional outcomes were assessed using the 1993 version of the Musculoskeletal Tumour Society (MSTS-93) score. Additionally, we quantified five types of complications and assessed osseointegration radiologically. The survivorship of the endoprosthesis was evaluated according to two endpoints. A total of 134 patients with a median age of 26 years (IQR 16 to 41) were included in our study. The median follow-up time was 61 months (IQR 56 to 76), and the median functional MSTS-93 was 83% (IQR 73 to 91) postoperatively.Aims
Methods
Hydroxyapatite (HA)-coated collars have been shown to reduce aseptic loosening of massive endoprostheses following primary surgery. Limited information exists about their effectiveness in revision surgery. The aim of this study was to radiologically assess osteointegration to HA-coated collars of cemented massive endoprostheses following revision surgery. Retrospective review of osseointegration frequency, pattern, and timing to a specific HA-coated collar on massive endoprostheses used in revision surgery at our tertiary referral centre between 2010 to 2017 was undertaken. Osseointegration was radiologically classified on cases with a minimum follow-up of six months.Aims
Methods
Bone metastasis ultimately occurs due to a complex multistep process, during which the interactions between cancer cells and bone microenvironment play important roles. Prior to colonization of the bone, cancer cells must succeed through a series of steps that will allow them to gain migratory and invasive properties; epithelial-to-mesenchymal transition (EMT) is known to be integral here. The aim of this study was to determine the effects of G protein subunit alpha Q (GNAQ) on the mechanisms underlying bone metastasis through EMT pathway. A total of 80 tissue samples from patients who were surgically treated during January 2012 to December 2014 were used in the present study. Comparative gene analysis revealed that the GNAQ was more frequently altered in metastatic bone lesions than in primary tumour sites in lung cancer patients. We investigated the effects of GNAQ on cell proliferation, migration, EMT, and stem cell transformation using lung cancer cells with GNAQ-knockdown. A xenograft mouse model tested the effect of GNAQ using micro-CT analyses and histological analyses.Aims
Methods
Massive endoprostheses rely on extra-cortical bone bridging (ECBB)
to enhance fixation. The aim of this study was to investigate the
role of selective laser sintered (SLS) porous collars in augmenting
the osseointegration of these prostheses. The two novel designs of porous SLS collars, one with small pores
(Ø700 μm, SP) and one with large pores (Ø1500 μm, LP), were compared
in an ovine tibial diaphyseal model. Osseointegration of these collars
was compared with that of a clinically used solid, grooved design
(G). At six months post-operatively, the ovine tibias were retrieved and
underwent radiological and histological analysis.Aims
Materials and Methods
Cancellous allograft bone chips are commonly
used in the reconstruction of defects in bone after removal of benign tumours.
We investigated the MRI features of grafted bone chips and their
change over time, and compared them with those with recurrent tumour.
We retrospectively reviewed 66 post-operative MRIs from 34 patients
who had undergone curettage and grafting with cancellous bone chips
to fill the defect after excision of a tumour. All grafts showed
consistent features at least six months after grafting: homogeneous
intermediate or low signal intensities with or without scattered
hyperintense foci (speckled hyperintensities) on T1 images; high
signal intensities with scattered hypointense foci (speckled hypointensities)
on T2 images, and peripheral rim enhancement with or without central
heterogeneous enhancements on enhanced images. Incorporation of
the graft occurred from the periphery to the centre, and was completed
within three years. Recurrent lesions consistently showed the same signal
intensities as those of pre-operative MRIs of the primary lesions.
There were four misdiagnoses, three of which were chondroid tumours. We identified typical MRI features and clarified the incorporation
process of grafted cancellous allograft bone chips. The most important
characteristics of recurrent tumours were that they showed the same
signal intensities as the primary tumours. It might sometimes be
difficult to differentiate grafted cancellous allograft bone chips
from a recurrent chondroid tumour. Cite this article:
The most concerning infection of allografts and operative procedures
is methicillin resistant An iontophoresis cell was set up with varying concentrations
of Vancomycin within the medulla of a section of sheep tibia, sealed
from an external saline solution. The cell was run for varying times,
Vancomycin concentrations and voltages, to gain information on optimisation
of conditions for impregnating the graft. Each graft was then sectioned
and dust ground from the exposed surface. The dust was serially
washed to extract the Vancomycin and concentrations measured and
plotted for all variables tested.Objectives
Methods
In skeletally immature patients, resection of
bone tumours and reconstruction of the lower limb often results
in leg-length discrepancy. The Stanmore non-invasive extendible
endoprosthesis, which uses electromagnetic induction, allows post-operative
lengthening without anaesthesia. Between 2002 and 2009, 55 children
with a mean age of 11.4 years (5 to 16) underwent reconstruction
with this prosthesis; ten patients (18.2%) died of disseminated
disease and one child underwent amputation due to infection. We
reviewed 44 patients after a mean follow-up of 41.2 months (22 to
104). The mean Musculoskeletal Tumor Society score was 24.7 (8 to
30) and the Toronto Extremity Salvage score was 92.3% (55.2% to
99.0%). There was no local recurrence of tumour. Complications developed
in 16 patients (29.1%) and ten (18.2%) underwent revision. The mean length gained per patient was 38.6 mm (3.5 to 161.5),
requiring a mean of 11.3 extensions (1 to 40), and ten component
exchanges were performed in nine patients (16.4%) after attaining
the maximum lengthening capacity of the implant. There were 11 patients
(20%) who were skeletally mature at follow-up, ten of whom had equal
leg lengths and nine had a full range of movement of the hip and
knee. This is the largest reported series using non-invasive extendible
endoprostheses after excision of primary bone tumours in skeletally
immature patients. The technique produces a good functional outcome,
with prevention of limb-length discrepancy at skeletal maturity.
Segmental resection of malignant bone disease in the femoral diaphysis with subsequent limb reconstruction is a major undertaking. This is a retrospective review of 23 patients who had undergone limb salvage by endoprosthetic replacement of the femoral diaphysis for a primary bone tumour between 1989 and 2005. There were 16 males and seven females, with a mean age of 41.3 years (10 to 68). The mean overall follow-up was for 97 months (3 to 240), and 120 months (42 to 240) for the living patients. The cumulative patient survival was 77% (95% confidence interval 63% to 95%) at ten years. Survival of the implant, with failure of the endoprosthesis as an endpoint, was 85% at five years and 68% (95% confidence interval 42% to 92%) at ten years. The revision rate was 22% and the overall rate of re-operation was 26%. Complications included deep infection (4%), breakage of the prosthesis (8%), periprosthetic fracture (4%), aseptic loosening (4%), local recurrence (4%) and metastases (17%). The 16 patients who retained their diaphyseal endoprosthesis had a mean Musculoskeletal Tumour Society score of 87% (67% to 93%). They were all able to comfortably perform most activities of daily living. Femoral diaphyseal endoprosthetic replacement is a viable option for reconstruction following segmental resection of malignant bone disease. It allows immediate weight-bearing, is associated with a good long-term functional outcome, has an acceptable complication and revision rate and, most importantly, does not appear to compromise patient survival.
Dedifferentiated chordoma is a rare and aggressive variant of the conventional tumour in which an area undergoes transformation to a high-grade lesion, typically fibrous histiocytoma, fibrosarcoma, and rarely, osteosarcoma or rhabdomyosarcoma. The dedifferentiated component dictates overall survival, with smaller areas of dedifferentiation carrying a more favourable prognosis. Although it is more commonly diagnosed in recurrences and following radiotherapy, there have been a few reports of spontaneous development. We describe four such cases, which were diagnosed