Dislocation post THA confers a higher risk of re-dislocation (Kotwal et al, 2009). The dual mobility (DM) cup design (1974) was aimed at improving the stability by increasing the femoral head to neck ratio (Cuthbert et al., 2019) combining the ideas of low friction arthroplasty with increased jump distance associated with a big head arthroplasty. Understand the dislocation rates, rates of aseptic loosening, infection rate and revision rates between the 2 types of constructs to provide current and up-to date evidence. Medline, pubmed, embase and Cochrane databases were used based on PRISMA guidelines. RevMan software was used for the meta-analysis. Studies (English literature) which used DM construct with atleast 6 months follow-up used as intervention and non DM construct as control were included. 2 independent reviewers conducted the review with a third reviewer in case of difference in opinion regarding eligibility. Primary outcome was dislocation rate and secondary outcome was rate of revision. 564 articles identified out of which 44 articles were screened for full texts and eventually 4 systematic review articles found eligible for the study. Thus, study became a review of systematic reviews. From the 4 systematic reviews, another 35 studies were identified for data extraction and 13 papers were used for meta-analysis. Systematic reviews evaluated, projected an average follow up of 6-8 years with significantly lower dislocation rates for DM cups. The total number of patients undergoing DM cup primary THA were 30,559 with an average age 71 years while the control group consisted of 218,834 patients with an average age of 69 years. DM group had lower rate of dislocation (p < 0.00001), total lower rate of cup revision (p < 0.00001, higher incidence of fracture (p>0.05). DM THA is a viable alternative for conventional THA. The long-term results of DM cups in primary THA need to be further evaluated using high quality prospective studies and RCTs

Abstract. Introduction. Dislocation post THA confers a higher risk of re-dislocation (Kotwal et al, 2009). The dual mobility (DM) cup design (1974) was aimed at improving the stability by increasing the femoral head to neck ratio (Cuthbert et al., 2019) combining the ideas of low friction arthroplasty with increased jump distance associated with a big head arthroplasty. Aims. Understand the dislocation rates, rates of aseptic loosening, infection rate and revision rates between the 2 types of constructs to provide current and up-to date evidence. Methods. Medline, pubmed, embase and Cochrane databases were used based on PRISMA guidelines. RevMan software was used for the meta-analysis. Studies (English literature) which used DM construct with atleast 6 months follow-up used as intervention and non DM construct as control were included. 2 independent reviewers conducted the review with a third reviewer in case of difference in opinion regarding eligibility. Primary outcome was dislocation rate and secondary outcome was rate of revision. Results. 564 articles identified out of which 44 articles were screened for full texts and eventually 4 systematic review articles found eligible for the study. Thus, study became a review of systematic reviews. From the 4 systematic reviews, another 35 studies were identified for data extraction and 13 papers were used for meta-analysis. Systematic reviews evaluated, projected an average follow up of 6–8 years with significantly lower dislocation rates for DM cups. The total number of patients undergoing DM cup primary THA were 30,559 with an average age 71 years while the control group consisted of 218,834 patients with an average age of 69 years. DM group had lower rate of dislocation (p < 0.00001), total lower rate of cup revision (p < 0.00001, higher incidence of fracture (p>0.05). Conclusion. DM THA is a viable alternative for conventional THA. The long-term results of DM cups in primary THA need to be further evaluated using high quality prospective studies and RCTs. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Introduction and Objective. Despite pure alumina have shown excellent long-term results in patients undergoing total hip arthroplasty (THA), alumina matrix composites (AMCs) composed of alumina and zirconium oxide are more commonly used. There are no comparative studies between these two different ceramics. We performed a retrospective case-control study to compare results and associated complications between AMC from two manufacturers and those with pure alumina from another manufacturer. Materials and Methods. 480 uncemented THAs with ceramic on ceramic (CoC) bearing surfaces (288 men and 192 women; mean age of 54.1 ± 12.4 years), were implanted from 2010 to 2015. Group 1: 281 THAs with pure alumina; Group 2A: 142 with AMC bearing in a trabecular titanium cup. Group 2B: 57 hips with AMC bearing with a porous-coated cup. Results. The mean follow-up was 7.3 years. There was one late infection in group 1, eight dislocations, three in group 1 (1.1%), three in group 2A (2.1%), all with a 36 mm femoral head, and two in group 2C (3.5%). Liner malseating was found in one hip in group 1, and in five hips in group 2C, of these, there were four liner fractures (7.0%). Four cups were revised for iliopsoas impingement (three in group 1 and one in group 2B). Two cups were revised for aseptic loosening, one in group 1 and one in group 2A, and four revised femoral stems in group 2A, three for subsidence and another for postoperative periprosthetic B. 2. fracture. The mean preoperative Harris Hip Score was 48.6 ± 3.3 in the whole series and 93.9 ± 7.2 at the end of follow-up. The survival rate of revision for any cause was 98.2% (95% Confidence Interval: 96.6–99.8) at ten years for group 1, 95.8% (95% CI: 92.1–99.5) for group 2A, and 91.1% (95% CI: 83.7–98.5) for group 2B (log-rank 0.030). Conclusions. Outcome of uncemented CoC THA in young patients was satisfactory at mid-term in all three groups. However, liner fractures were frequent in group 2B. All dislocated hips in group 2A had a 36 mm femoral head diameter, and revision due to any cause was less frequent in group 1. Pure alumina CoC THA can be used as a benchmark for comparison with newer CoC THAs

Introduction. The management of periprosthetic pelvic bone loss is a challenging problem in hip revision surgery. This study evaluates the minimum 10-year clinical and radiographic outcome of major column structural allografts combined with the Burch-Schneider antiprotrusio cage for acetabular reconstruction. Methods. From January 1992 to August 2005, 106 hips with periprosthetic osteolysis underwent acetabular revision using massive allografts and the Burch-Schneider antiprotrusio cage. Forty-five patients (49 hips) died for unrelated causes without further surgery. Fifty-nine hips in 59 patients underwent clinical and radiographic evaluation at an average follow-up of 15.1 years. There were 17 male and 42 female patients, with age ranging from 29 to 83 years (mean 59). Results. Ten hips required rerevision because of infection (3), aseptic loosening (6), and flange breakage (1). Moreover, 4 cages showed x-ray signs of instability with severe bone resorption. The survivorship of the Burch-Schneider cage at 21.9 years with removal for any reason or radiographic migration and aseptic or radiographic failure as the end points were 76.3 and 81.4, respectively. The average Harris hip score improved from 33.2 points preoperatively to 75.7 points at the latest follow-up (p < 0.001). Discussion. In hip revision surgery, severe deficiency of pelvic bone stock is a critical concern because of the difficulty in providing a stable and durable fixation of the prosthesis. Although antiprotrusio cages have a limited role in acetabular revision, the use in association with massive allografts in extended bone loss demonstrated highly successful long-term results, enabling bone stock restoration and cup stability

Objectives. Our objective was to perform a systematic review of the literature and conduct a meta-analysis to investigate the outcomes of open versus arthroscopic methods of ankle fusion. Methods. In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement standards, we performed a systematic review. Electronic databases MEDLINE, EMBASE, CINAHL and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched to identify randomised and non-randomised studies comparing outcomes of arthroscopic and open ankle arthrodesis. The Newcastle-Ottawa scale was used to assess the methodological quality and risk of bias of the selected studies. Fixed-effect or random-effects models were applied to calculate pooled outcome data. Results. We identified one prospective cohort study and 5 retrospective cohort studies, enrolling a total of 286 patients with ankle arthritis. Our analysis showed that open ankle fusion was associated with a lower fusion rate (OR 0.26, 95% CI 0.13–0.52, P = 0.0002), longer tourniquet time (MD 16.49, 95% CI 9.46–23.41, P<0.00001), and longer length of stay (MD 1.60,95% CI 1.10–2.10, P<0.00001) compared to arthroscopic ankle fusion; however, there was no significant difference between two groups in terms of infection rate (OR 2.41, 95% CI 0.76–7.64, P = 0.14), overall complication rate (OR: 1.54, 95% CI 0.80–2.96, P = 0.20), and operation time (MD 4.09, 95% CI −2.49–10.66, P = 0.22). The between-study heterogeneity was high for tourniquet time but low or moderate for other outcomes. The direction of the effect sizes remains unchanged throughout sensitivity analyses. Conclusions. The best available evidence demonstrates that arthroscopic ankle fusion may be associated with a higher fusion rate, shorter tourniquet time, and shorter length of stay compared to open ankle fusion. We found no significant difference between two groups in terms of infection rate, overall complication rate, and operation time. The best available evidence is not adequately robust to make definitive conclusions. Long-term results of the comparative efficacy of arthroscopic ankle fusion over open ankle fusion are not currently available. Further high quality randomised controlled trials that are adequately powered are required

Objectives. Our objective was to perform a systematic review of the literature and conduct a meta-analysis to investigate the outcomes of open versus arthroscopic methods of ankle fusion. Methods. In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement standards, we performed a systematic review. Electronic databases MEDLINE, EMBASE, CINAHL and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched to identify randomised and non-randomised studies comparing outcomes of arthroscopic and open ankle arthrodesis. The Newcastle-Ottawa scale was used to assess the methodological quality and risk of bias of the selected studies. Fixed-effect or random-effects models were applied to calculate pooled outcome data. Results. We identified one prospective cohort study and 5 retrospective cohort studies, enrolling a total of 286 patients with ankle arthritis. Our analysis showed that open ankle fusion was associated with a lower fusion rate (OR 0.26, 95% CI 0.13–0.52, P = 0.0002), longer tourniquet time (MD 16.49, 95% CI 9.46–23.41, P<0.00001), and longer length of stay (MD 1.60,95% CI 1.10–2.10, P<0.00001) compared to arthroscopic ankle fusion; however, there was no significant difference between two groups in terms of infection rate (OR 2.41, 95% CI 0.76–7.64, P = 0.14), overall complication rate (OR: 1.54, 95% CI 0.80–2.96, P = 0.20), and operation time (MD 4.09, 95% CI −2.49–10.66, P = 0.22). The between-study heterogeneity was high for tourniquet time but low or moderate for other outcomes. The direction of the effect sizes remains unchanged throughout sensitivity analyses. Conclusions. The best available evidence demonstrates that arthroscopic ankle fusion may be associated with a higher fusion rate, shorter tourniquet time, and shorter length of stay compared to open ankle fusion. We found no significant difference between two groups in terms of infection rate, overall complication rate, and operation time. The best available evidence is not adequately robust to make definitive conclusions. Long-term results of the comparative efficacy of arthroscopic ankle fusion over open ankle fusion are not currently available. Further high quality randomised controlled trials that are adequately powered are required

Total Hip Arthroplasty (THA) is a well-established, cost-effective treatment for improving function and alleviating pain in patients who have disabling hip disease with excellent long-term results. Based on the excellent results, there is an ongoing trend for THA to be performed in younger and more active patients, having higher physical demands on their new total joints. Polyethylene (PE) wear and its biological consequences are one of the main causes of implant failure in THA. Macrophages phagocytise PE wear particles and this will result in osteolysis and loss of periprosthetic bone. The risk of these complications can be estimated in relation to the amount of volumetric wear based on two assumptions: that the number of PE particles dispersed in the peri-prosthetic tissues is controlled by the amount of PE wear; and that the development of osteolysis and the resulting aseptic loosening is triggered by these PE particles. Based on these assumptions, a model was developed to estimate the osteolysis-free life of a THA, depending on the Linear Wear Rate (LWR) and femoral head size of the PE bearing. A review of the literature was conducted to provide an estimate of the radiologic osteolysis threshold based on the volumetric wear of the PE bearing. This review demonstrates that this radiologic osteolysis threshold is approximated 670 mm3 for conventional PE. The osteolysis-free life of the THA was estimated by simply dividing this threshold volume by the annual Volumetric Wear Rate (VWR) of the bearing. The annual VWR is basically controlled by two parameters: (1) annual LWR and (2) head size, and was calculated by using published formulae. For 28 mm heads, following osteolysis-free life was determined in function of the annual LWR. LWR: 10 µm/y => 116.6 years / LWR: 25 µm/y => 46.6 years / LWR: 50 µm/y => 23.3 years / LWR: 100 µm/y => 11.6 years. For 40 mm heads, following osteolysis-free life was determined in function of the annual LWR. LWR: 10 µm/y => 57.1 years / LWR: 25 µm/y => 22.9 years / LWR: 50 µm/y => 11.4 years / LWR: 100 µm/y => 5.7 years. The osteolysis-free life determined by this model is in good agreement with the clinical results of PE bearings having a 28 mm head size and demonstrates that extreme low LWRs are mandatory to assure a descent osteolysis-free life for THA (PE bearings) using large heads, such as 40 mm. For such head sizes, small variations of the LWR may have large impacts on the osteolysis-free life of the THA

Background. To determine if double needle ultrasound-guided hydrodissolution and aspiration of intratendinous calcification is more effective treatment than blind subacromial corticosteroid injection. Methods. A prospective randomised comparative clinical study of 32 patients suffering from chronic symptomatic calcific tendinosis of the supraspinatous tendon. Group A (16 patients) received a double needle ultrasound-guided aspiration of the calcification, while group B (16 patients) underwent a blind subacromial betamethazone injection. As far as group A, we attached a syringe in the first needle, including 10cc. of normal saline (N/S), that we injected targeting the calcium deposit. Then we tried to achieve consecutive aspirations through the second needle. Results. Patients were evaluated by an independent researcher who measured the visual analogue scale (VAS) 100/100 and the range of motion (ROM): a. before, b. 10 days and c. 6 months after the injection. In most cases of group A, we observed a noticeable amount of aspirated milky or mixed white-red coloured fluid at the bottom of the syringe. This fact proves right and effective guidance of the ultrasound. After six months, we documented full –or almost full- decline (VAS: 0–20/100) of the symptoms in 62.75 % of the group A patients and in 43.75% of the group B patients. The 6 month's mean VAS fall rate was 45/100 in group A and 33/100 in group B. Corticosteroid injected patients proved to have better outcome inside the first 10 days. The mean abduction of the humerus in the 6 month's follow-up was 110 degrees (from 77.5 degrees prior to aspiration) for the group A and 85 degrees for group B (from 72.5 degrees -prior). Conclusion. Double needle dissolution -and aspiration- with N/S represents better long-term results (regarding ROM and pain release) than blind corticosteroid injection in the treatment of chronic symptomatic calcific tendinosis. Level I

Background. Focal resurfacing can treat localised articular damage of the knee not appropriate for arthroplasty or biological repair. Independent results on these implants are limited. We previously published early results showing significantly improved Knee Injury & Osteoarthritis Outcome Score (KOOS4) without complication or re-operation, demonstrating this system gives good analgesia and functional improvement in selected patients. We present long-term follow-up of these patients. Methods. We prospectively evaluated medium- to long-term results in patients with localised, full-thickness articular cartilage defects of the knee undergoing HemiCAP resurfacing. All procedures were performed by one consultant surgeon. Post-operative rehabilitation was standardised. Outcome measures were KOOS4 score, visual analogue score (VAS), Kellgren and Lawrence arthritis grade, and re-operation rates. Results. Six patients were evaluated with mean follow-up time of 74 months (range 61–96). Mean age was 44.8 years (range 33–51). One lateral and five medial compartments were resurfaced. Mean pre-operative KOOS4 was 39.1, mean 22-month follow-up KOOS4 improved significantly to 79.6, and mean latest follow-up KOOS4 remained good at 71.3. Mean VAS was 8.8 at latest follow-up. There was no loosening, migration or increase in osteoarthritis grade. One patient underwent revision to unicondylar knee replacement for pain after three years with comparable results at another centre (medial compartment, two year follow-up pre-revision KOOS4 84.6, latest follow-up post-revision KOOS4 73.6, VAS 6). Cause of pain was unclear (heel pain causing prolonged altered weight-bearing or failure of HemiCAP). Conclusion. Our results demonstrate that the use of the joint-preserving HemiCAP system provides good pain relief and functional improvement in both the short and longer-term. Few studies assess functional outcomes of focal resurfacing for localised full thickness articular cartilage defects. Our study assesses both the contemporaneous and time-dependent behaviour of focal resurfacing. We believe this is one of the longest follow-up series to date

Dysplasia Epiphysealis Hemimelica (DEH) also known as Trevor's Disease is a rare developmental disorder resulting in cartilaginous overgrowth of the epiphysis of long bones. DEH is usually diagnosed in children between two and eight years old and it is three times more often diagnosed in boys. The most reported complaints are pain, limitation in range of motion, and deformity or swelling of the affected joint. Treatment of symptomatic lesions consists of surgical resection of the lesion, resulting in good long-term results. Based on histological evaluation, DEH is often described as an osteochondroma or an osteochondroma-like lesion, although there are clinical, radiological and genetic differences between DEH and osteochondromas. To investigate the hypothesis that DEH and osteochondromas are histologically identical, two cases of DEH and two cases of osteochondromas in patients with Hereditary Multiple Osteochondroma (HMO) are compared at histological level. Tissue samples from patients with a histopathologically confirmed diagnosis of DEH were compared with two age and gender matched patients diagnosed with HMO. After tissue sampling and processing, (immuno)histological stainings were performed for Collagen type II, Collagen type X, Sox-9 and Safranin-O. Histologically, clumping of chondrocytes in a fibrillar matrix, a thick disorganized cartilage cap and ossification centres with small amounts of unresorbed cartilage were observed in DEH. In contrast, chondrocyte organisation in cartilage of osteochondromas displays characteristics of the normal growth plate. In addition, differences in expression of collagen type II, collagen type X and Sox9 were observed. Collagen type II was expressed in the extracellular matrix surrounding proliferative and hypertrophic chondrocytes in osteochondromas, while weak expression was observed in the entire cartilage cap in DEH. Collagen type X was not expressed in DEH, while expressed in the pericellular matrix surrounding hypertrophic chondrocytes in osteochondromas. Staining for Sox9 was positive in the hypertrophic chondrocytes in osteochondromas, while expressed in the nuclei of all chondrocyte clusters in DEH. Both morphological and immunohistological differences were observed in histological sections of DEH and osteochondromas. These findings reject our hypothesis, and supports the earlier observed clinical, radiological and genetic differences and implies a different aetiology between DEH and osteochondroma formation in HMO

While stable long-term clinical results have been achieved in total joint arthroplasty, periprosthetic joint infection (PJI) has been actualized as difficult issue in this decade. For accurate diagnosis, it is important to establish standard criteria such as MSIS criteria, and it is prevailing now. As an issue involving PJI, however, the existence of viable, but non-culturable (VNC) bacteria must be noticed. It is difficult to identify the VNC state infection, because microbiologic culture result shows negative and other markers tend to be negative. Here, molecular diagnosis based on polymerase chain reaction (PCR) has certain role as potential diagnostic tools for such VNC infection. We have applied a real-time PCR system for the diagnosis of PJI, which is able to detect methicillin-resistant Staphylococcus (MRS) and distinguish gram-positive from gram-negative bacteria. The prominent advantage is that PCR is the singular way to identify MRS in such culture negative cases. Recent development of full-automatic PCR system may improve the time efficiency for routine application. In this presentation, we will show the overall sensitivity and specificity of our PCR system for diagnosing PJI and discuss the current problem and future prospect

Summary Statement. A three dimensional meniscal scaffold with controlled fibre diameter and orientation was fabricated by an improved E-Jetting system that mimic the internal structure of natural meniscus. In vitro cellular tests proved its feasibility in meniscal tissue engineering applications. Introduction. Current surgical and repair methods for complex meniscal injuries still do not often give satisfactory long-term results. Thus, scaffold-based grafts are the subject of much research interest. However, one major hurdle is that current techniques are unable to replicate the precise 3D microstructure of meniscus, nor the variations in the fibrillar structure and tissue content from layer to layer. In this work, an improved electrohydrodynamic jet printing system (E-Jetting system) was developed to fabricate biomimetic meniscal scaffold for tissue regeneration. Methods. Polycaprolactone (PCL) and ACS reagent grade acetic acid were purchased from Sigma-Aldrich. 70% w/v PCL solution was prepared by dissolving polymer in acetic acid. A customised hydrodynamic E-Jetting system was employed to fabricate the scaffold. Scaffold topography was observed by optical microscope (OM) and scanning electron microscope (SEM). Chondrocytes were used to evaluate the in vitro biological properties of scaffolds, including cell viability, sulfated glycosaminoglycan (sGAG) production, as well as gene expression of chondrogenic markers. Mechanical testing was also performed on the scaffolds with and without cell loading. Results. Meniscal scaffolds of specific fiber orientation were fabricated in a single fabrication run at room temperature. These scaffolds were printed with circumferentially oriented PCL fibers interspersed with radial fibers, which mimic the internal structure of the natural meniscus. In vitro cell culture tests demonstrated that chondrocytes attached and spread well on the scaffolds, and produced significant extracellur matrix of cartilage (sGAG and collagen type II). Mechanical test was conducted on the meniscus scaffolds. Significantly enhanced tensile strength was seen on cell-laden scaffolds compared with that without cells. Discussion/Conclusion. The three dimensional meniscal scaffold with controlled fibre diameter and orientation fabricated by the improved E-Jetting system was able to approach the internal structure of natural meniscus. Chondrocytes attached and spread well on the scaffolds, maintained their healthy phenotypes within the scaffold, and produced cartilage-like extracelluar matrix. Cell loading further enhanced the mechanical strength of scaffolds and replicated the anisotropic mechanical property of natural meniscus. It is proposed that the E-jetted meniscal scaffold has the potential for future applications in meniscal replacement therapeutic options

Cheilectomy of the big toe is offered in the early stages of arthritis affecting the big toe MTPJ, with the understanding that if it fails then a more definitive surgical treatment (e.g. MTPJ fusion or replacement) may be required. When considering treatment options, patients want to know how long will a cheilectomy procedure last. There is limited evidence available about the long term results after cheliectomy, particularly with regards to time to revision surgery. Our aim was to establish the long-term results of cheilectomy with regards to revision surgery and patient-satisfaction over a period of 10 years. A retrospective review of big toe MTPJ cheilectomies was performed at our institute from 2002 to 2012. The patients were identified using a combination of medical coding system, clinical records, operative log, and radiographs. A systemic review of chielectomy by Roukis (2010) was identified as the clinical standard and revision surgery after cheilectomy, average time to revision and patient satisfaction was assessed. 204 cheilectomies were identified in 192 patients over a period of 10 years. Majority had grade 2 OA (n = 106, 54 %) with grade 3 (n= 65, 33 %) and grade 1 (n= 24, 12 %). The mean follow-up was 4 yrs. (range 6 m to 9 yrs. and 8 m). The overall revision rate to any surgery was 4.4% (n=9), and revision to MTPJ arthrodesis was 3.4% (n =7). The average time to revision was 1 yr. 4 m. 101 patients (55%) were contactable over the phone, and majority (82 %) of them were satisfied with the clinical outcome. This study shows slightly better overall revision rate (4.4% vs. 8.8%), with revision to arthrodesis being similar (3.4% vs. 3.25%) as compared to the clinical standard. It also suggests that cheilectomy of the big toe can last for a minimum of up to 4 years in 95 % of cases. The 5 % of cases that may require revision surgery are likely to present within the first 2 years. This information is very useful to a patient who wants to know “how long will my cheilectomy last?” whilst making an informed choice

Introduction. Osteonecrosis of the femoral head occurs in young patients. The preservation of the hip joint is vitally important, because hip arthroplasty does not guarantee satisfactory long-term results in young and active patients. Curved intertrochanteric varus osteotomy is one of several joint preserving procedures used for this disease. Methods. Between June 2004 and June 2007, 52 patients (55 hips) who had osteonecrosis of the femoral head were treated with curved intertrochanteric varus osteotomy. There were 29 men and 23 women who had a mean age at the time of osteotomy of 33 years (range, 18 to 52 years). The osteotomy was fixed with a 120 degree compression hip screw in the first 34 hips and with a 95 degree dynamic condylar screw in the remaining 21 hips. Clinical evaluation was performed using the scoring system of Merle d'Aubigne et al. Results. The mean duration of follow-up was 32 months (range, 24 to 60 months). Six patients (six hips) required a total hip arthroplasty, due to loss of fixation in two hips, shortening of the operated limb in two hips, and further collapse with persistent pain in two hips. In two patients (two hips), the plate fractured at 3 and 4 months after the operation, which was changed to a new plate. Thus, 49 of the 55 hips survived at a mean follow-up 32 months. In these hips, the mean Merle d'Aubigne hip score was 17.4 points at the latest evaluation. Conclusion. Curved intertrochanteric varus osteotomy is a satisfactory joint preserving method to treat osteonecrosis of the femoral head

Aims

Second-generation metal-on-metal (MoM) articulations in total hip arthroplasty (THA) were introduced in order to reduce wear-related complications. The current study reports on the serum cobalt levels and the clinical outcome at a minimum of 20 years following THA with a MoM (Metasul) or a ceramic-on-polyethylene (CoP) bearing.

Aternatives to autogenous bone graft for spinal fusion have been investigated for many years. It has been shown that osteoconductive materials alone do not give a rate of fusion which is comparable to that of autogenous bone graft. We analysed the effectiveness of porous ceramic loaded with cultured mesenchymal stem cells as a new graft material for spinal fusion in an animal model. Posterolateral fusion was carried out at the L4/L5 level in 40 White New Zealand rabbits using one of the following graft materials: porous ceramic granules plus cultured mesenchymal stem cells (group I); ceramic granules plus fresh autogenous bone marrow (group II); ceramic granules alone (group III); and autogenous bone graft (group IV). The animals were killed eight weeks after surgery and the spines were evaluated radiographically, by a manual palpation test and by histological analysis. The rate of fusion was significantly higher in group I compared with group III and higher, but not significantly, in group I compared with groups II and IV. In group I histological analysis showed newly formed bone in contact with the implanted granules and highly cellular bone marrow between the newly formed trabecular bone. In group II, thin trabeculae of newly formed bone were present in the peripheral portion of the fusion mass. In group III, there was a reduced mount of newly formed bone and abundant fibrous tissue. In group IV, there were thin trabeculae of newly formed bone close to the decorticated transverse processes and dead trabecular bone in the central portion of the fusion mass. In vitro cultured mesenchymal stem cells may be loaded into porous ceramic to make a graft material for spinal fusion which appears to be more effective than porous ceramic alone. Further studies are needed to investigate the medium- to long-term results of this procedure, its feasibility in the clinical setting and the most appropriate carrier for mesenchymal stem cells

Summary. The 80% porous structure of trabecular metal allows for bone ingrowth in more than 90% of the available surface. The Nexgen LPS Uncemented Knee using a trabecular metal tibial component has performed well at minimum of 5 years’ follow-up. Introduction. Total Knee Arthroplasty prostheses most frequently used in today's practice have cemented components. These have shown excellent clinical results. The fixation can however weaken with time, and cement debris within the articulation can lead to accelerated wear. Cementless implants are less commonly used, but some have also shown good long-term clinical results. The potential advantages of cementless implants are retention of bone stock, less chance of third-body wear due to the absence of cement, shorter operative time, and easier treatment of periprosthetic fractures. The posterior stabilised knee replacement has been said to increase tangential shear stresses on the tibial component and increases contact stresses on the cam and post mechanism hence the great debate of cruciate retaining or cruciate sacrificing implants. Objectives. We report the results of a prospective cohort of consecutive primary total knee arthroplasties using an uncemented posterior stabilised prosthesis using a trabecular metal (tantalum) tibial component at a minimum 5-year follow-up. Methods. Prospective 5 year follow-up of patients undergone an uncemented posterior stabilised total knee replacement using a trabecular metal tibial component (NexgenLPS). Clinical examination, Oxford knee score, Knee society score, SF12 and radiological evaluation undertaken at review. Results. 81 patients, 45 female, 36 male. Left 31, Right 50. Mean age 74.3 yrs range (51–90). SF12, mean: 31.8 range (25–37). Oxford Knee Score Pre-op Mean 20.1 range (9–36) Post op: Mean 32.1 range (9–48). Knee Society score. Pain Mean 91.8; range (60–100). Functional score mean 76.2; range (30–100). Mean Range of movement 110.5 degrees range (90–125). No evidence of loosening at 5 yrs. No deep infection. No Revisions. Conclusion. Although there are a variety of methods of achieving satisfactory initial fixation in cementless components, trabecular metal has an advantage owing to its cellular structure resembling bone. The 80% porous structure of trabecular metal allows for bone ingrowth in more than 90% of the available surface. The Nexgen LPS Uncemented Knee using a trabecular metal tibial component used in this series has shown no evidence of loosening at a minimum of 5 years’ follow-up and the prosthesis as a whole has performed very well clinically. Its early results are comparable to those prostheses most commonly used as reported by the arthroplasty registers. The longer term results from this prosthesis are awaited with interest

We have previously shown that joint distraction and movement with a hinged external fixation device for 12 weeks was useful for repairing a large articular cartilage defect in a rabbit model. We have now investigated the results after six months and one year. The device was applied to 16 rabbits who underwent resection of the articular cartilage and subchondral bone from the entire tibial plateau. In group A (nine rabbits) the device was applied for six months. In group B (seven rabbits) it was in place for six months, after which it was removed and the animals were allowed to move freely for an additional six months. The cartilage remained sound in all rabbits. The areas of type II collagen-positive staining and repaired soft tissue were larger in group B than in group A. These findings provide evidence of long-term persistence of repaired cartilage with this technique and that weight-bearing has a positive effect on the quality of the cartilage.

We used a biodegradable mesh to convert an acetabular defect into a contained defect in six patients at total hip replacement. Their mean age was 61 years (46 to 69). The mean follow-up was 32 months (19 to 50). Before clinical use, the strength retention and hydrolytic in vitro degradation properties of the implants were studied in the laboratory over a two-year period. A successful clinical outcome was determined by the radiological findings and the Harris hip score.

All the patients had a satisfactory outcome and no mechanical failures or other complications were observed. No protrusion of any of the impacted grafts was observed beyond the mesh. According to our preliminary laboratory and clinical results the biodegradable mesh is suitable for augmenting uncontained acetabular defects in which the primary stability of the implanted acetabular component is provided by the host bone. In the case of defects of the acetabular floor this new application provides a safe method of preventing graft material from protruding excessively into the pelvis and the mesh seems to tolerate bone-impaction grafting in selected patients with primary and revision total hip replacement.

Thrombin has many biological properties similar to those of growth factors. In a previous study, we showed that thrombin improves healing of the rat tendo Achillis. Low molecular weight heparin (LMWH) inhibits the activity and the generation of thrombin. We therefore considered that LMWH at a thromboprophylactic dose might inhibit tendon repair.

Transection of the tendo Achillis was carried out in 86 rats and the healing tested mechanically. Low molecular weight heparin (dalateparin) was either injected a few minutes before the operation and then given continuously with an osmotic mini pump for seven days, or given as one injection before the operation. In another experiment ,we gave LMWH or a placebo by injection twice daily. The anti-factor Xa activity was analysed.

Continuous treatment with LMWH impaired tendon healing. After seven days, this treatment caused a 33% reduction in force at failure, a 20% reduction in stiffness and a 67% reduction in energy uptake. However, if injected twice daily, LMWH had no effect on tendon healing. Anti-factor Xa activity was increased by LMWH treatment, but was normal between intermittent injections.

Low molecular weight heparin delays tendon repair if given continuously, but not if injected intermittently, probably because the anti-factor Xa activity between injections returns to normal, allowing sufficient thrombin stimulation for repair. These findings indicate the need for caution in the assessment of long-acting thrombin and factor Xa inhibitors.