A heavy infiltrate of foreign-body macrophages is commonly seen in the fibrous membrane which surrounds an aseptically loose cemented implant. This is in response to particles of polymethylmethacrylate (PMMA) bone cement and other biomaterials. We have previously shown that monocytes and macrophages responding to particles of bone cement are capable of differentiating into osteoclastic cells which resorb bone. To determine whether the radio-opaque additives barium sulphate (BaSO. 4. ) and zirconium dioxide (ZrO. 2. ) influence this process, particles of PMMA with and without these agents were added to mouse monocytes and cocultured with osteoblast-like cells on bone slices. Osteoclast differentiation, as shown by the presence of the osteoclast-associated enzyme tartrate-resistant acid phosphatase (TRAP) and lacunar bone resorption, was observed in all cocultures. The addition of PMMA alone to these cocultures caused no increase in TRAP expression or bone resorption relative to control cocultures. Adding PMMA particles containing BaSO. 4. or ZrO. 2. , however, caused an increase in TRAP expression and a highly significant increase in bone resorption. Particles containing BaSO. 4. were associated with 50% more bone resorption than those containing ZrO. 2. . Our results suggest that radio-opaque agents in bone cement may contribute to the bone resorption of aseptic loosening by enhancing macrophage-osteoclast differentiation, and that PMMA containing is BaSO. 4. likely to be associated with more osteolysis than that containing ZrO. 2.

We investigated the possibility that the macrophages which are seen around implants may stimulate bone resorption and cause loosening. We found that macrophages release mediators that stimulate bone resorption, and that the amount of resorption increased by between 2.5 and 10 times when the macrophages adhered to a foreign surface. This bone resorption depended on the surface energy and roughness of the foreign surface, varying with these physical properties rather than with the chemical nature of the material. It is concluded that loosening of orthopaedic implants is likely to be influenced by the surface energy and roughness of the implant

We investigated in vitro a mechanism by which particulate debris may induce bone resorption and cause implant loosening. We first studied two standard particles: latex, which is considered to be inert, and zymosan, which is inflammatory. Macrophages that phagocytosed either particle became activated, and stimulated 15 times as much bone resorption as did control macrophages. For activation to occur, 100 times more latex than zymosan had to be phagocytosed. We also found that bone cement and polyethylene particles activated macrophages in a similar manner, and that the necessary amounts of these were intermediate between those of latex and zymosan. None of the particles were toxic. It was concluded that implant loosening may result from bone resorption stimulated by mediators released by macrophages that have phagocytosed particles of bone cement or polyethylene

Calvaria from six-day-old infant mice were grown on a grid culture in a chemically defined medium under varying oxygen tensions. Quantitative isotope studies demonstrated a linear association between bone resorption and oxygen tension in the physiological range. This result was supported by histological, histochemical and vital staining experiments. The clinical finding of osteoporosis in areas of hyperaemia could therefore be attributed to a rise in oxygen tension causing increased bone resorption

Using a rat model, we created a bone-to-titanium interface and applied phagocytosable high-density polyethylene pArticles between the bone and implant, either initially or when the interface had matured. No fibrous membrane developed and no bone resorption was found. If sliding movements were initiated at the interface after two weeks, there was formation of a fibrous membrane. The additional application of pArticles did not change the thickness of the membrane, and there were only minor qualitative changes. Creation of a membrane by movement followed by cessation of movement and the application of pArticles caused the membrane to persist, whereas in a pArticle-free control group bone-to-metal contact was re-established. Our findings suggest that mechanical stimuli are of primary importance for prosthetic loosening, and that pArticles may modulate the later stages of the loosening process

We reviewed at a minimum elapsed time of five years a consecutive series of 143 primary Exeter hip replacements in which matt-surfaced femoral stems had been used. Twenty-five patients had died and six stems and two sockets had been revised before follow-up. The remaining 110 hips were all examined clinically and radiographically. In 15 hips there were radiographic signs of definite loosening of the stem and in eight suspected loosening. The acetabulum was loose in four hips. In another eight hips localised bone resorption was present without signs of loosening. Half the patients with loosening or localised bone resorption had mild pain or no pain at all. The late complication rate with the matt-surfaced Exeter femoral stem is unacceptably high

Wear particles commonly used for experiments may carry adherent endotoxin on their surfaces, which may be responsible for the observed effects. In this study, we attached titanium plates to the tibiae of 20 rats. After osseointegration, endotoxin-contaminated or uncontaminated high-density-polyethylene (HDPE) particles were applied. Contaminated specimens showed a dramatic resorption of bone after seven days but new bone filled the site again at 21 days. Uncontaminated specimens showed no resorption. In 18 rats we implanted intramuscularly discs of ultra-high-molecular-weight polyethylene (UHMWPE) with baseline or excess contamination of endotoxin. Excess endotoxin disappeared within 24 hours and the amount of endotoxin remained at baseline level (contamination from production). Uncontaminated titanium discs did not adsorb endotoxin in vivo. The endotoxin was measured by analytical chemistry. Locally-applied endotoxin stimulated bone resorption similarly to that in experiments with wear particles. Endotoxin on the surface of implants and particles appeared to be inactivated in situ. A clean implant surface did not adsorb endotoxin. Our results suggest that endotoxin adhering to orthopaedic implants is not a major cause for concern

Inadequate bone stock is often found in revision surgery of femoral components of total knee replacements. Our aim was to test the hypothesis that these remodelling patterns can be explained by stress shielding, and that prosthetic bonding characteristics affect maintenance of bone mass. We made a three-dimensional finite-element model of an average male femur with a cemented femoral knee component. This model was integrated with iterative remodelling procedures. Two extreme prosthetic bonding conditions were analysed and gradual changes in bone density were calculated. The long-term bone loss under the femoral knee component resembled clinical findings which confirms the hypothesis that stress shielding can cause distal femoral bone loss. Our study predicts, contrary to clinical findings, that an equilibrium situation is not reached after two years, but that bone resorption may continue. This hidden bone loss may be so drastic that large reconstructions are needed at the time of revision

Matrix metalloproteinases (MMPs) may have a role in the process of aseptic loosening. Doxycycline has been shown to inhibit MMPs. Our aim was to investigate the potential pharmacological effect of doxycycline on aseptic loosening. We used radiolabelled mouse calvariae cultured with human interface membrane cells from aseptically loosened hips. Bone resorption was confirmed in this model. The effect of doxycycline was assessed by culturing dead radiolabelled bone discs with cells from the interface membrane with doxycycline. The control group consisted of the same culture system without doxycycline. Supernatant . 45. calcium and the total . 45. calcium remaining in the bone discs at the completion of the culture were used to measure osteolysis. We found that doxycycline can inhibit osteolysis at the interface membrane of aseptically loosened hips. This may have therapeutic implications for the treatment of patients with aseptic loosening of total joint replacements

Aims

It has been hypothesized that proximal radial neck resorption (PRNR) following press-fit radial head arthroplasty (RHA) is due to stress-shielding. We compared two different press-fit stems by means of radiographs to investigate whether the shape and size of the stems are correlated with the degree of PRNR.

Peri-prosthetic osteolysis and subsequent aseptic loosening is the most common reason for revising total hip replacements. Wear particles originating from the prosthetic components interact with multiple cell types in the peri-prosthetic region resulting in an inflammatory process that ultimately leads to peri-prosthetic bone loss. These cells include macrophages, osteoclasts, osteoblasts and fibroblasts. The majority of research in peri-prosthetic osteolysis has concentrated on the role played by osteoclasts and macrophages. The purpose of this review is to assess the role of the osteoblast in peri-prosthetic osteolysis.

In peri-prosthetic osteolysis, wear particles may affect osteoblasts and contribute to the osteolytic process by two mechanisms. First, particles and metallic ions have been shown to inhibit the osteoblast in terms of its ability to secrete mineralised bone matrix, by reducing calcium deposition, alkaline phosphatase activity and its ability to proliferate. Secondly, particles and metallic ions have been shown to stimulate osteoblasts to produce pro inflammatory mediators in vitro. In vivo, these mediators have the potential to attract pro-inflammatory cells to the peri-prosthetic area and stimulate osteoclasts to absorb bone. Further research is needed to fully define the role of the osteoblast in peri-prosthetic osteolysis and to explore its potential role as a therapeutic target in this condition.

Cite this article: Bone Joint J 2013;95-B:1021–5.

Aims

The primary aim of this study was to compare the wear properties of vitamin E-diffused, highly crosslinked polyethylene (VEPE) and one formulation of moderately crosslinked and mechanically annealed ultra-high molecular weight polyethylene (ModXLPE) in patients five years after primary total hip arthroplasty (THA). The secondary aim was to assess the clinical results of patients treated with VEPE by evaluating patient-reported outcome measures (PROMs), radiological evidence of fixation, and the incidence of mechanical failure.

Aims

The aim of this study was to evaluate the clinical and radiological outcome of using an anatomical short-stem shoulder prosthesis to treat primary osteoarthritis of the glenohumeral joint.

Bone defects are frequently observed in anterior shoulder instability. Over the last decade, knowledge of the association of bone loss with increased failure rates of soft-tissue repair has shifted the surgical management of chronic shoulder instability. On the glenoid side, there is no controversy about the critical glenoid bone loss being 20%. However, poor outcomes have been described even with a subcritical glenoid bone defect as low as 13.5%. On the humeral side, the Hill-Sachs lesion should be evaluated concomitantly with the glenoid defect as the two sides of the same bipolar lesion which interact in the instability process, as described by the glenoid track concept. We advocate adding remplissage to every Bankart repair in patients with a Hill-Sachs lesion, regardless of the glenoid bone loss. When critical or subcritical glenoid bone loss occurs in active patients (> 15%) or bipolar off-track lesions, we should consider anterior glenoid bone reconstructions. The techniques have evolved significantly over the last two decades, moving from open procedures to arthroscopic, and from screw fixation to metal-free fixation. The new arthroscopic techniques of glenoid bone reconstruction procedures allow precise positioning of the graft, identification, and treatment of concomitant injuries with low morbidity and faster recovery. Given the problems associated with bone resorption and metal hardware protrusion, the new metal-free techniques for Latarjet or free bone block procedures seem a good solution to avoid these complications, although no long-term data are yet available. Cite this article: Bone Joint J 2024;106-B(10):1100–1110

Aims. The aim of this study was to analyze how proximal radial neck resorption (PRNR) starts and progresses radiologically in two types of press-fit radial head arthroplasties (RHAs), and to investigate its clinical relevance. Methods. A total of 97 patients with RHA were analyzed: 56 received a bipolar RHA (Group 1) while 41 received an anatomical implant (Group 2). Radiographs were performed postoperatively and after three, six, nine, and 12 weeks, six, nine, 12, 18, and 24 months, and annually thereafter. PRNR was measured in all radiographs in the four radial neck quadrants. The Mayo Elbow Performance Score (MEPS), the abbreviated version of the Disabilities of the Arm, Shoulder, and Hand questionnaire (QuickDASH), and the patient-assessed American Shoulder and Elbow Surgeons score - Elbow (pASES-E) were used for the clinical assessment. Radiological signs of implant loosening were investigated. Results. The mean follow-up was six years (2 to 14). PRNR started after a mean of 7.5 weeks (SD 2.1) and progressed significantly during the first two years, by the end of which the bone resorption stabilized. PRNR was detected in 81% (n = 45) of patients in Group 1 and 88% (n = 36) in Group 2. The final mean PRNR was 3.0 mm (SD 2.3) in Group 1 and 3.7 mm (SD 2.5) in Group 2. The mean MEPS, QuickDASH, and pASES-E were 95.9 (SD 11.5), 4.4 (SD 9.2), and 94.8 (SD 10.9) in Group 1 and 92.2 (SD 16.2), 9.9 (SD 21.5), and 90.8 (SD 15) in Group 2, respectively. No significant differences were observed between groups in the clinical and radiological outcomes. No correlations were found between PRNR and the clinical results. Conclusion. PRNR after press-fit RHA is a common radiological finding that develops in the first 24 months before stabilizing definitively. PRNR does not affect the clinical results or implant survival in the mid term. Cite this article: Bone Joint J 2023;105-B(8):905–911

Aims. Osteopetrosis (OP) is a rare hereditary disease that causes reduced bone resorption and increased bone density as a result of osteoclastic function defect. Our aim is to review the difficulties, mid-term follow-up results, and literature encountered during the treatment of OP. Methods. This is a retrospective and observational study containing data from nine patients with a mean age of 14.1 years (9 to 25; three female, six male) with OP who were treated in our hospital between April 2008 and October 2018 with 20 surgical procedures due to 17 different fractures. Patient data included age, sex, operating time, length of stay, genetic type of the disease, previous surgery, fractures, complications, and comorbidity. Results. The mean follow-up period was 92.5 months (25 to 140). Bony union was observed in all of our patients. Osteomyelitis developed in two patients with femoral shaft fractures, and two patients had peri-implant stress fractures. Conclusion. Treatment of fractures in OP patients is difficult, healing is protracted, and the risk of postoperative infection is high. In children and young adults with OP who have open medullary canal and the epiphyses are not closed, fractures can be treated with surgical techniques such as intramedullary titanium elastic nail (TENS) technique or fixation with Kirschner (K)-wire. Cite this article: Bone Joint J 2020;102-B(8):1082–1087

1. In growing rats oestrogen, cortisone and thyroxine in high doses suppress bone formation, and this effect is probably part of a general suppression of body growth. 2. Growth hormone and thyroxine in small doses stimulate both body growth and bone formation. 3. Testosterone has no effect on bone formation. 4. Oestrogen and cortisone suppress bone resorption. The effect of cortisone may be modified in conditions of calcium depletion. 5. Thyroxine appears on the other hand to increase bone resorption. 6. Testosterone has no effect on bone resorption

Aims

Loosening of components after total knee arthroplasty (TKA) can be associated with the development of radiolucent lines (RLLs). The aim of this study was to assess the rate of formation of RLLs in the cemented original design of the ATTUNE TKA and their relationship to loosening.

Ununited fractures of the scaphoid with extensive bone resorption are usually treated by bone grafting and internal fixation, using either an open or a minimally invasive technique. We studied the feasibility of percutaneous fixation without bone grafting in a consecutive series of 27 patients with established nonunion of an undisplaced fracture of the scaphoid and extensive local resorption of bone. They were treated by a single surgeon with rigid fixation alone, using a headless cannulated screw inserted through a volar percutaneous technique. Clinical examination, standard radiographs and CT confirmed that the fracture had united in all patients at a mean of 11.6 weeks (8 to 16), and that their functional scores had improved. We concluded that extensive resorption at the fracture site is not an absolute indication for bone grafting, and that percutaneous fixation alone will eventually produce healing of ununited undisplaced fractures of the scaphoid regardless of the size of the gap

Aims

Accurate diagnosis of chronic periprosthetic joint infection (PJI) presents a significant challenge for hip surgeons. Preoperative diagnosis is not always easy to establish, making the intraoperative decision-making process crucial in deciding between one- and two-stage revision total hip arthroplasty (THA). Calprotectin is a promising point-of-care novel biomarker that has displayed high accuracy in detecting PJI. We aimed to evaluate the utility of intraoperative calprotectin lateral flow immunoassay (LFI) in THA patients with suspected chronic PJI.

The effects of the method of fixation and interface conditions on the biomechanics of the femoral component of the Birmingham hip resurfacing arthroplasty were examined using a highly detailed three-dimensional computer model of the hip. Stresses and strains in the proximal femur were compared for the natural femur and for the femur resurfaced with the Birmingham hip resurfacing. A comparison of cemented versus uncemented fixation showed no advantage of either with regard to bone loading. When the Birmingham hip resurfacing femoral component was fixed to bone, proximal femoral stresses and strains were non-physiological. Bone resorption was predicted in the inferomedial and superolateral bone within the Birmingham hip resurfacing shell. Resorption was limited to the superolateral region when the stem was not fixed. The increased bone strain observed adjacent to the distal stem should stimulate an increase in bone density at that location. The remodelling of bone seen during revision of failed Birmingham hip resurfacing implants appears to be consistent with the predictions of our finite element analysis

Aims

This multicentre retrospective observational study’s aims were to investigate whether there are differences in the occurrence of radiolucent lines (RLLs) following total knee arthroplasty (TKA) between the conventional Attune baseplate and its successor, the novel Attune S+, independent from other potentially influencing factors; and whether tibial baseplate design and presence of RLLs are associated with differing risk of revision.

We examined the cellular responses to various particles injected into the knees and the intramedullary femoral cavities of rats in the presence of polymethyl-methacrylate (PMMA) plugs. The intra-articular particles were mainly ingested by synovial fibroblasts. Increased numbers of macrophages were not detected and there was only a slight increase in synovial thickness. Cellular responses in the intramedullary space were similarly mild and bone resorption around the PMMA plug did not occur. Bone formation was inhibited only by polyethylene particles. In contrast to current views, our study shows that wear particles per se do not initiate bone resorption

The purpose of this study was to determine the biological effects of the elastic modulus of the femoral stem in canine hip arthroplasty. Cementless total hip arthroplasty was performed in 12 dogs, six had a low elastic modulus polyacetal resin stem and six had a high modulus stainless steel stem. The components were otherwise similar. At six and 12 months after operation, radiographic and histomorphometric analysis showed that those with steel implants had more cortical porosity than did the other group (p less than 0.01). We suggest that the elastic modulus of the implant is an important factor in controlling cortical bone resorption. A low modulus femoral prosthesis can significantly decrease bone resorption which might otherwise eventually lead to implant failure

Our aim was to investigate the relationship between urinary excretion of deoxypyridinoline (DPD) as a marker of bone resorption, and Perthes’ disease. There were 39 children with Perthes’ disease in the florid stage who collected first-morning urine samples at regular intervals of at least three months. The level of urinary DPD was analysed by chemiluminescence immunoassay and was correlated with the radiological stage of the disease as classified by Waldenström, and the severity of epiphyseal involvement according to the classification systems of Catterall and Herring. The urinary DPD levels of a group of 44 healthy children were used as a control. The median urinary DPD/creatinine (CREA) ratio was significantly reduced (p < 0.0001) in the condensation stage and increased to slightly elevated values at the final stage (p = 0.05) when compared with that of the control group. Herring-C patients showed significantly lower median DPD/CREA ratios than Herring-B patients (p = 0.03). The significantly decreased median DPD/CREA ratio in early Perthes’ disease indicated a reduced bone turnover and supports the theory of a systemic aetiology. Urinary levels of DPD may therefore be used to monitor the course of Perthes’ disease

Cancer-induced bone diseases are often associated with increased bone resorption and pathological fractures. In recent years, osteoprotective agents such as bisphosphonates have been studied extensively and have been shown to inhibit cancer-related bone resorption in experimental and clinical studies. The third-generation bisphosphonate, ibandronate (BM 21.0955), is a potent compound for controlling tumour osteolysis and hypercalcaemia in rats bearing Walker 256 carcinosarcoma. We have studied the effect of ibandronate given as an interventional treatment on bone strength and bone loss after the onset of tumour growth in bone. Our results suggest that it is capable of preserving bone quality in rats bearing Walker 256 carcinosarcoma cells. Since other bisphosphonates have produced comparable results in man after their success in the Walker 256 animal models our findings suggest that ibandronate may be a powerful treatment for maintaining skeletal integrity in patients with metastatic bone disease

The release of prostaglandins E and F from the tibiae of rabbits and the surrounding muscle in vitro after fracture and pinning, or pinning alone, has been compared to the release from unoperated tissues. The fractured tibiae released significantly more prostaglandins E and F than the control tibiae three to 14 days after operation. The pinned tibiae also released more of the two prostaglandins, although this was significant only after 14 days. Consequently it was only around the third day that the fractured tibiae released significantly more prostaglandin E than the tibiae which had been pinned, but not fractured. Similar results were obtained for the release from the muscles surrounding the tibiae. Prostaglandins are important mediators of inflammation as well as potent stimulators of bone resorption. Their increased formation in response to fracture and pinning may stimulate the vascular changes, bone resorption and the proliferation of osteogenic cells observed after trauma to bone

We present the clinical and radiological results of percutaneous vertebroplasty in the treatment of 58 vertebral compression fractures in 51 patients at a minimum follow-up of two years. Group 1 consisted of 39 patients, in whom there was no associated intravertebral cleft, whilst group 2 comprised 12 patients with an intravertebral cleft. The Oswestry disability index (ODI) and visual analogue scale (VAS) scores were recorded prospectively. The radiological evidence of kyphotic deformity, vertebral height, leakage of cement and bone resorption around the cement were studied restrospectively, both before and after operation and at the final follow-up. The ODI and VAS scores in both groups decreased after treatment, but the mean score in group 2 was higher than that in group 1 (p = 0.02 (ODI), p = 0.02 (VAS)). There was a greater initial correction of the kyphosis in group 2 than in group 1, although the difference was not statistically significant. However, loss of correction was greater in group 2. Leakage of cement was seen in 24 (41.4%) of 58 vertebrae (group 1, 32.6% (15 of 46); group 2, 75% (9 of 12)), mainly of type B through the basal vertebral vein in group 1 and of type C through the cortical defect in group 2. Resorption of bone around the cement was seen in three vertebrae in group 2 and in one in group 1. There were seven adjacent vertebral fractures in group 1 and one in group 2. Percutaneous vertebroplasty is an effective treatment for osteoporotic compression fractures with or without an intravertebral cleft. Nonetheless, higher rates of complications related to the cement must be recognised in patients in the presence of an intravertebral cleft

We investigated the circulating levels of the main cytokines involved in bone resorption (IL-1β, IL-6, TNF-α), prostaglandins (PGE. 2. ) and metalloproteases (MMP-1), as possible early markers of osteolysis, in the serum of eight patients with periprosthetic osteolysis and ten patients without osteolysis. All had received a cementless hip prosthesis (ABG-1). We also assessed the serum levels of IL-11 and TGF-β anti-inflammatory cytokines exerting protective effect on bone resorption. The mean serum levels of IL-1β, IL-6, TNF-α, TGF-β, MMP-1, and PGE. 2. in patients with periprosthetic osteolysis did not differ significantly from those of patients without osteolysis or from those of normal controls. IL-11 serum levels were not detectable at all in any of the patients, while they were detected within normal reference values in the control subjects (significant inverse correlation). We believe that circulating cytokines cannot be regarded as markers of osteolysis, a condition characterised by a local inflammation without systemic signs of inflammation. On the contrary, the undetectable levels of IL-11 in implanted patients could provide evidence for a lack of balance between pro- and anti-inflammatory cytokines in these patients

We evaluated the effect of low-intensity pulsed ultrasound stimulation (LIPUS) on the remodelling of callus in a rabbit gap-healing model by bone morphometric analyses using three-dimensional quantitative micro-CT. A tibial osteotomy with a 2 mm gap was immobilised by rigid external fixation and LIPUS was applied using active translucent devices. A control group had sham inactive transducers applied. A region of interest of micro-CT was set at the centre of the osteotomy gap with a width of 1 mm. The morphometric parameters used for evaluation were the volume of mineralised callus (BV) and the volumetric bone mineral density of mineralised tissue (mBMD). The whole region of interest was measured and subdivided into three zones as follows: the periosteal callus zone (external), the medullary callus zone (endosteal) and the cortical gap zone (intercortical). The BV and mBMD were measured for each zone. In the endosteal area, there was a significant increase in the density of newly formed callus which was subsequently diminished by bone resorption that overwhelmed bone formation in this area as the intramedullary canal was restored. In the intercortical area, LIPUS was considered to enhance bone formation throughout the period of observation. These findings indicate that LIPUS could shorten the time required for remodelling and enhance the mineralisation of callus

Mononuclear osteoclast precursors are present in the wear-particle-associated macrophage infiltrate found in the membrane surrounding loose implants. These cells are capable of differentiating into osteoclastic bone-resorbing cells when co-cultured with the rat osteoblast-like cell line, UMR 106, in the presence of 1,25(OH). 2. vitamin D. 3. In order to develop an in vitro model of osteoclast differentiation which more closely parallels the cellular microenvironment at the bone-implant interface in situ, we determined whether osteoblast-like human bone-derived cells were capable of supporting the differentiation of osteoclasts from arthroplasty-derived cells and analysed the humoral conditions required for this to occur. Long-term co-culture of arthroplasty-derived cells and human trabecular-bone-derived cells (HBDCs) resulted in the formation of numerous tartrate-resistant-acid-phosphatase (TRAP) and vitronectin-receptor (VNR)-positive multinucleated cells capable of extensive resorption of lacunar bone. The addition of 1,25(OH). 2. vitamin D. 3. was not required for the formation of osteoclasts and bone resorption. During the formation there was release of substantial levels of M-CSF and PGE. 2. Exogenous PGE. 2. (10. −8. to 10. −6. M) was found to stimulate strongly the resorption of osteoclastic bone. Our study has shown that HBDCs are capable of supporting the formation of osteoclasts from mononuclear phagocyte precursors present in the periprosthetic tissues surrounding a loose implant. The release of M-CSF and PGE. 2. by activated cells at the bone-implant interface may be important for the formation of osteoclasts at sites of pathological bone resorption associated with aseptic loosening

Aims

The aim of this study was to compare the mid-term patient-reported outcome, bone remodelling, and migration of a short stem (Collum Femoris Preserving; CFP) with a conventional uncemented stem (Corail).

Aims

The purpose of this study was to compare clinical results, long-term survival, and complication rates of stemless shoulder prosthesis with stemmed anatomical shoulder prostheses for treatment of osteoarthritis and to analyze radiological bone changes around the implants during follow-up.

The ageing population and an increase in both the incidence and prevalence of cancer pose a healthcare challenge, some of which is borne by the orthopaedic community in the form of osteoporotic fractures and metastatic bone disease. In recent years there has been an increasing understanding of the pathways involved in bone metabolism relevant to osteoporosis and metastases in bone. Newer therapies may aid the management of these problems. One group of drugs, the antibody mediated anti-resorptive therapies (AMARTs) use antibodies to block bone resorption pathways. This review seeks to present a synopsis of the guidelines, pharmacology and potential pathophysiology of AMARTs and other new anti-resorptive drugs. . We evaluate the literature relating to AMARTs and new anti-resorptives with special attention on those approved for use in clinical practice. Denosumab, a monoclonal antibody against Receptor Activator for Nuclear Factor Kappa-B Ligand. It is the first AMART approved by the National Institute for Health and Clinical Excellence and the US Food and Drug Administration. Other novel anti-resorptives awaiting approval for clinical use include Odanacatib. Denosumab is indicated for the treatment of osteoporosis and prevention of the complications of bone metastases. Recent evidence suggests, however, that denosumab may have an adverse event profile similar to bisphosphonates, including atypical femoral fractures. It is, therefore, essential that orthopaedic surgeons are conversant with these medications and their safe usage. . Take home message: Denosumab has important orthopaedic indications and has been shown to significantly reduce patient morbidity in osteoporosis and metastatic bone disease. Cite this article: Bone Joint J 2016;98-B:160–5

Aims

This study compared the cobalt and chromium serum ion concentration of patients treated with two different metal-on-metal (MoM) hinged total knee arthroplasty (TKA) systems, as well as a titanium nitride (TiN)-coated variant.

Aims

We aimed to evaluate the long-term outcome of highly cross-linked polyethylene (HXLPE) cemented acetabular components and assess whether any radiolucent lines (RLLs) which arose were progressive.

Aims

Highly cross-linked polyethylene (HXLPE) has greatly improved the durability of total hip arthroplasty (THA) in young patients because of its improved wear characteristics. Few studies have followed this population into the second decade, and therefore the purpose of this investigation was to evaluate the clinical outcome for THA patients 50 years of age and younger at a minimum of 15 years postoperatively. The second purpose was to evaluate the radiological findings secondary to wear or mechanical failure of the implant.

Aims

Cement-in-cement revision of the femoral component represents a widely practised technique for a variety of indications in revision total hip arthroplasty. In this study, we compare the clinical and radiological outcomes of two polished tapered femoral components.

Aims

Adverse local tissue reactions associated with abnormal wear considerably slowed down the general use of metal-on-metal (MoM) hip resurfacing arthroplasty (HRA), now limited to a few specialized centres. In this study, we provide the clinical results of 400 consecutive MoM HRAs implanted more than 20 years ago in one such centre.

Aims

Stemmed tibial components are frequently used in revision total knee arthroplasty (TKA). The purpose of this study was to evaluate patient satisfaction, overall pain, and diaphyseal tibial pain in patients who underwent revision TKA with cemented or uncemented stemmed tibial components.

An operation is described in which a microvascular technique was used to transfer a living fibula, with its vascular pedicle intact, to replace the lower end of the radius after massive resection for giant-cell tumour. Angiography carried out six weeks later showed that the grafted bone was viable. Six months after operation the transplanted fibula showed no osteoporosis or bone resorption and bony union at the junction of host and graft

Aims

The purpose of this study was to report bone adaptive changes after anatomical total shoulder arthroplasty (TSA) using a standard-length hydroxyapatite (HA)-coated humeral component, and to report on a computer-based analysis of radiographs to determine changes in peri-implant bone density objectively.

Chronic recurrent multifocal osteomyelitis (CRMO) is characterised by an insidious onset of fever, local swelling and pain in affected bones, and radiological abnormalities suggestive of osteomyelitis. The histopathological features in 14 patients are described. Morphologically CRMO begins as an acute inflammatory process with a predominance of polymorphonuclear leucocytes, which occasionally form an abscess and osteoclastic bone resorption. At a later stage the predominant features are lymphocytes in the inflammatory infiltrates and occasional granulomatous foci and sigans of bone formation. The clinical course may be prolonged for many years

Three madreporic prostheses in two patients were examined to evaluate resorption and formation of the surrounding bone tissue. All three prostheses were firmly fixed and had no clinical or radiographic signs of loosening. Transverse sections were examined by scanning electron microscopy at 40 days, 11 months and 2.5 years after implantation. The findings suggest that adaptive bone remodelling varies along the length of the stem; that bone resorption and formation are related to the time after implant; and that new bone formation (woven bone) can be found very close to the madreporic surface

1. The phosphonates are simple chemical compounds containing P-C-P bonds which are resistant to the action of naturally occurring phosphatases and pyrophosphatases. They inhibit the formation and dissolution of apatite crystals in vitro and prevent ectopic mineralisation and bone resorption in animals. 2. In man one diphosphonate (EHDP) has been shown to reduce the excessive turnover of bone in Paget's disease and also appears to slow the mineralisation of ectopic bone matrix in myositis ossificans progressiva. 3. The possible uses of the diphosphonates in bone disorders with excessive resorption and in ectopic mineralisation are being further investigated

1. Tetracycline labelling methods have been used to measure the rate of growth in length and the rate of growth in width of the tibia of the normal rat. 2. The main limitations of the tetracycline methods are that in very young animals the bands of labelled bone are indistinct and remodelling occurs quickly; in animals nearing maturity, the growth in width is very slow and periods of at least fourteen days are required to give reliable results. 3. The tetracycline labelling methods can be used also to determine changes in the basic processes of bone formation and bone resorption

1. Twenty-three patients were treated by cross screwing for diastasis of the tibia and fibula in fractures at the ankle. 2. It is suggested that limitation of ankle dorsiflexion after this treatment was caused by the presence of a mechanical block to dorsiflexion by spur formation at the margins of tibia and talus. 3. An ordinary bone screw controlled the diastasis satisfactorily in twenty patients. 4. The screw did not interfere with movement at the inferior tibio-fibular joint because bone resorption about that part of the screw in the fibula allowed a small range of movement. 5. Discomfort from the screw was relieved by its removal

1. The bone changes in four autopsied cases of Cushing's syndrome are described. The changes take the form of osteoporosis, which is most marked in the spine and the ribs. 2. The osteoporosis results from impaired osteoblastic bone formation in the presence of a normal degree of osteoclastic bone resorption. 3. Histological abnormalities of fracture callus in Cushing's syndrome indicate interference with the proliferation of osteoblasts and cartilage cells and with the formation of new tissue by these cells. 4. The bone changes in Cushing's syndrome are comparable with those produced in experimental animals by the administration of A.C.T.H. or cortisone

We treated 50 patients with bony malignancy by en-bloc resection, extracorporeal irradiation with 50 Gy and re-implantation of the bone segment. The mean survivor follow-up was 38 months (12 to 92) when 42 patients were alive and without disease. There were four recurrences. The functional results were good according to the Mankin score (17 excellent, 13 good, nine fair, three failures), the Musculoskeletal Tumour Society score (mean 77) and the Toronto Extremity Salvage score (mean 81). There was solid union, but bone resorption was seen in some cases. The dose of radiation was lethal to all cells and produced a dead autograft of perfect fit. Extracorporeal irradiation is a useful technique for limb salvage when there is reasonable residual bone stock. It allows effective re-attachment of tendons and produces a lasting biological reconstruction. There should be no risk of local recurrence or of radiotherapy-induced malignancy in the replanted bone

We have investigated whether the particle-stimulated release of inflammatory cytokines from human primary macrophages in vitro was dependent upon the type of bone cement used. Particles of clinically relevant size were produced from Palacos R without radio-opacifier, Palacos R with BaSO. 4. , Palacos R with ZrO. 2. and from CMW3 which contains BaSO. 4. All four preparations produced significantly greater release of tumour necrosis factor alpha, interleukin-6 and interleukin-1 beta than a negative control but there were no significant differences between them. The differences in the ability to stimulate bone resorption and in clinical performance between proprietary bone cements previously recorded are not explained by the release of the cytokines most commonly implicated in osteolysis