Introduction. Total hip arthroplasty (THA) using short design stem is surging with increasing movement of minimally invasive techniques. Short stems are easier to insert through small incisions preserving muscles. We have used these types of short stems since 2010. Almost all of the patients have shown good clinical results. However, two patients developed fatigue fractures on femurs post operatively. We have reviewed the clinical and radiographic results of these patients. Patients and methods. From April 2010, we have performed 621 THAs with short design stems, Microplasty. R. , Biomet, using a muscle preservation approach, the Direct Anterior Approach (DAA). The age ranged from 31 to 88 years old. Case1: 56y.o. male, BMI 23.1kg/m. 2. Preoperative diagnosis was bilateral osteoarthritis. Simultaneous THAs were performed on bilateral hips. He was allowed to bear as much weight as he could tolerate using an assistive device immediately after surgery, and followed standard hip precautions for the first 3 weeks. He was discharged from hospital seven days after surgery and returned to his job two weeks after surgery. He noticed sudden left thigh pain three weeks after surgery without any obvious cause. Crutches were recommended to partially bear his weight. Six weeks after surgery, a fracture line became visible on the radiographs and new callus formation also became visible. Three months after surgery, he felt no pain and was able to walk without any crutches. Case2: 66y.o. female, BMI 27.5 kg/m. 2. Preoperative diagnosis was bilateral osteoarthritis. THAs were performed on the hips at a six month interval. The right hip was operated on first, followed by the left hip. She was discharged from hospital four days after surgery and returned to her job six weeks after surgery. Two months later after left hip surgery, she suddenly felt pain on her left femur without any obvious cause, and was unable to walk. Three weeks later, X-rays showed fatigue fracture lines and new callus formations. After two or three months using crutches, her pain improved and X-rays showed good callus formation and no stem subsidence. Discussions. Several reports showed insufficiency fractures of the pelvis following THA. But most of them occurred due to repetitive stress on fragile bones. But our cases showed no evidence of osteoporosis. They had no history of trauma. But they had some points in common, which were they were bilateral cases and their BMI were not low. The incident rate of fatigue fractures of femur with this short stem THAs was 0.3% in our cases. We suggested that one of the causes of these fatigue fractures was the shortness of the stems. The shortness of the stems concentrate the body weight to limited contact area of the femur, and the stress causes the fatigue fractures. We should consider the risk of fatigue fractures on the patients who are operated on bilaterally. However these two patients showed good callus formations and no stem subsidence after a few weeks of partial weight bearing

Femoral component fracture is a rarely reported but devastating complication of total knee arthroplasty. It has occurred most frequently with Whiteside Ortholoc II replacements uncemented knee replacements. Presentation may be with acute pain, progressive pain or returning deformity. It occurs more commonly in the medial condyle of the femoral component. It is rarely seen in cemented replacements. All currently available literature describing fractures of condylar replacements, both cemented and uncemented. Predisposing factors include varus deformity either pre or post operatively. The mechanism of failure is thought to be failure of the infiltration of bone into the replacement. This is often due to polyethylene wear or metallosis causing abnormal tissue reaction with or without osteolysis. We present the case of a fractured Press Fit Condylar (PFC) cemented implant (DePuy, Johnson&Johnson, Raynham, Massachusettes, USA) affecting the medial condyle. To our knowledge this is only the third reported case of fracture in a PFC implant, and the first in a cemented PFC implant. Our patient was a 64 year old male who presented with unresolving knee pain post total knee arthroplasty, caused by fatigue fracture of the medial condyle of the femoral component. This was identified as loosening on plain radiographs and replaced with a revision prosthesis with a good post operative result. Given our aging population and with the increase of joint arthroplasty, this case sheds light on a potentially under recognised and increasingly important cause of knee pain following arthroplasty

Introduction. A significant burden of disease exists with respect to critical sized bone defects; outcomes are unpredictable and often poor. There is no absolute agreement on what constitutes a “critically-sized” bone defect however it is widely considered as one that would not heal spontaneously despite surgical stabilisation, thus requiring re-operation. The aetiology of such defects is varied. High-energy trauma with soft tissue loss and periosteal stripping, bone infection and tumour resection all require extensive debridement and the critical-sized defects generated require careful consideration and strategic management. Current management practice of these defects lacks consensus. Existing literature tells us that tibial defects 25mm or great have a poor natural history; however, there is no universally agreed management strategy and there remains a significant evidence gap. Drawing its origins from musculoskeletal oncology, the Capanna technique describes a hybrid mode of reconstruction. Mass allograft is combined with a vascularised fibula autograft, allowing the patient to benefit from the favourable characteristics of two popular reconstruction techniques. Allograft confers initial mechanical stability with autograft contributing osteogenic, inductive and conductive capacity to encourage union. Secondarily its inherent vascularity affords the construct the ability to withstand deleterious effects of stressors such as infection that may threaten union. The strengths of this hybrid construct we believe can be used within the context of critical-sized bone defects within tibial trauma to the same success as seen within tumour reconstruction. Methodology. Utilising the Capanna technique in trauma requires modification to the original procedure. In tumour surgery pre-operative cross-sectional imaging is a pre-requisite. This allows surgeons to assess margins, plan resections and order allograft to match the defect. In trauma this is not possible. We therefore propose a two-stage approach to address critical-sized tibial defects in open fractures. After initial debridement, external fixation and soft tissue management via a combined orthoplastics approach, CT imaging is performed to assess the defect geometry, with a polymethylmethacrylate (PMMA) spacer placed at index procedure to maintain soft tissue tension, alignment and deliver local antibiotics. Once comfortable that no further debridement is required and the risk of infection is appropriate then 3D printing technology can be used to mill custom jigs. Appropriate tibial allograft is ordered based on CT measurements. A pedicled fibula graft is raised through a lateral approach. The peroneal vessels are mobilised to the tibioperoneal trunk and passed medially into the bone void. The cadaveric bone is prepared using the custom jig on the back table and posterolateral troughs made to allow insertion of the fibula, permitting some hypertrophic expansion. A separate medial incision allows attachment of the custom jig to host tibia allowing for reciprocal cuts to match the allograft. The fibula is implanted into the allograft, ensuring nil tension on the pedicle and, after docking the graft, the hybrid construct is secured with multi-planar locking plates to provide rotational stability. The medial window allows plate placement safely away from the vascular pedicle. Results. We present a 50-year-old healthy male with a Gustilo & Anderson 3B proximal tibial fracture, open posteromedially with associated shear fragment, treated using the Capanna technique. Presenting following a fall climbing additional injuries included a closed ipsilateral calcaneal and medial malleolar fracture, both treated operatively. Our patient underwent reconstruction of his tibia with the above staged technique. Two debridements were carried out due to a 48-hour delay in presentation due to remote geographical location of recovery. Debridements were carried out in accordance with BOAST guidelines; a spanning knee external fixator applied and a small area of skin loss on the proximal medial calf reconstructed with a split thickness skin graft. A revision cement spacer was inserted into the metaphyseal defect measuring 84mm. At definitive surgery the external fixator was removed and graft fixation was extended to include the intra-articular fragments. No intra-operative complications were encountered during surgeries. The patient returned to theatre on day 13 with a medial sided haematoma. 20ml of haemoserous fluid was evacuated, a DAIR procedure performed and antibiotic-loaded bioceramics applied locally. Samples grew Staphylococcus aureus and antibiotic treatment was rationalised to Co-Trimoxazole 960mg BD and Rifampicin 450mg BD. The patient has completed a six-week course of Rifampicin and continues on suppressive Co-Trimoxazole monotherapy until planned metalwork removal. There is no evidence of ongoing active infection and radiological evidence of early union. The patient is independently walking four miles to the gym daily and we believe, thus far, despite accepted complications, we have demonstrated a relative early success. Conclusions. A variety of techniques exist for the management of critical-sized bone defects within the tibia. All of these come with a variety of drawbacks and limitations. Whilst acceptance of a limb length discrepancy is one option, intercalary defects of greater than 5 to 7cm typically require reconstruction. In patients in whom fine wire fixators and distraction osteogenesis are deemed inappropriate, or are unwilling to tolerate the frequent re-operations and potential donor site morbidity of the Masqualet technique, the Capanna technique offers a novel solution. Through using tibial allograft to address the size mismatch between vascularised fibula and tibia, the possible complication of fatigue fracture of an isolated fibula autograft is potentially avoidable in patients who have high functional demands. The Capanna technique has demonstrated satisfactory results within tumour reconstruction. Papers report that by combining the structural strength of allograft with the osteoconductive and osteoinductive properties of a vascularised autograft that limb salvage rates of greater than 80% and union rates of greater than 90% are achievable. If these results can indeed be replicated in the management of critical-sized bone defects in tibial trauma we potentially have a treatment strategy that can excel over the more widely practiced current techniques

Ti-6Al-4V is the most common alloy used for orthopaedic implants. Its popularity is due to low density, superior corrosion resistance, good osseointegration and lower elastic modulus when compared to other commonly used alloys such as CoCrMo and stainless steel. In fact, the use of Ti64 has even further increased lately since recent controversy around adverse local tissue reactions and implant failure related to taper corrosion of CoCrMo alloy. However, implants made from Ti64 can fail in some cases due to fatigue fracture, sometimes related to oxide induced stress corrosion cracking or hydrogen embrittlement, or preferential corrosion of the beta phase. Studies performed with Ti-6Al-4V do often not consider that the alloy itself may have a range of characteristics that can vary and could significantly impact the implant properties. These variations are related to the material microstructure which depends not only on chemical composition, but also the manufacturing process and subsequent heat treatments. Different microstructures can occur in implants made form wrought alloys, cast alloys, and more recently, additive manufactured (AM) alloys. Implant alloy microstructure drives mechanical and electrochemical properties. Therefore, this study aims to analyse the microstructure of Ti-6Al-4V alloy of additive manufactured and conventional retrieved orthopaedic implants such as acetabular cups, tibial trays, femoral stem and modular neck by means of electron backscatter diffraction (EBSD). Microstructural features of interest include grains shape and size, phase content and distribution, preferred grain orientation (texture), alloying elements distribution (homogenization) and presence of impurities. Additionally, we demonstrate the direct impact of different microstructural features on hardness. We analysed 17 conventional devices from 6 different manufacturers, 3 additive manufactured devices from 2 different manufactures and 1 control alloy (bar stock). The preliminary results showed that even though all implants have the same chemical composition, their microstructural characteristics vary broadly. Ti64 microstructure of conventional alloys could be categorized in 3 groups: equiaxed grains alloys (Fine and Coarse), bimodal alloys and dendritic alloys. The additive manufactured implants were classified in an additional group on its own which consists of a needle-like microstructures - similar to Widmanstätten patterns, Fig. 1, with a network of β phase along α phase grains. Furthermore, AM alloys exhibited residual grain boundaries from the original β grains from the early stage of the solidification process, Fig. 2. These characteristics may have implication on the fatigue and corrosion behaviour. In addition, it we observed inhomogeneous alloying element distribution in some cases, Fig. 3, especially for the additive manufactured alloys, which also may have consequences on corrosion behaviour. Finally, the hardness testing revealed that the implants with large grain size, such as AM alloys, exhibit low hardness values, as expected, but also the amount of beta phase correlated positively with lower hardness. Grain aspect ratio and beta phase grain size correlated positively with higher hardness. In summary, we found that common Ti64 implants can exhibit a broad variety of different alloy microstructures and the advent of AM alloys introduces an entirely new category. It is imperative to determine the ideal microstructure for specific applications

Cement fixation of the glenoid implants in total shoulder arthroplasty has been the norm since the procedure has existed. Yet, an unacceptably high rate of lucent lines, representing prosthetic loosening, and a high rate of resultant failure of fixation of these implants continues to be the single most common cause for revision surgery in total shoulder arthroplasty. Dissatisfaction with a higher than acceptable rate of lucent lines, cement fixation of the glenoid component has led us to evaluate and employ an implant anchored into the glenoid vault with a woven tantalum (trabecular metal) fixation stem. We have employed this implant in patients with healthy bone stock with a minimum 2-year follow-up in well over 100 cases with only one revision performed in a first generation implant due to fatigue fracture. No cases have demonstrated lucency or loosening. The procedure does require meticulous attention to detail to ensure precise surface and glenoid vault preparation providing complete intraosseous seating of the trabecular metal anchor and flush apposition and support of the polyethylene surface upon the face of the glenoid. This process has reduced surgical preparation time as well as time required for cement setting by an average of 20 minutes per case

In a society whereby the incidence of obesity is increasing and medico-legal implications of treatment failure are more frequently ending with the consulting doctor, clarity is required as to any restrictions placed on common orthopaedic implants by manufacturing companies. The aim of this study was to identify any restrictions placed on the commonly used femoral stem implants in total hip replacement (THR) surgery, by the manufacturers, based on patient weight. The United Kingdom (UK) National Joint Registry (NJR) was used to identify the five most commonly used cemented and uncemented femoral stem implants during 2012. The manufacturing companies responsible for these implants were asked to provide details of any weight restrictions placed on these implants. The Corail size 6 stem is the only implant to have a weight restriction (60Kg). All other stems, both cemented and uncemented, were free of any restrictions. Fatigue fracture of the femoral stem has been well documented in the literature, particularly involving the high nitrogen stainless steel cemented femoral stems and to a lesser extent the cemented cobalt chrome and uncemented femoral stems. In all cases excessive patient weight leading to increased cantilever bending of the femoral stem was thought to be a major factor contributing to the failure mechanism. From the current literature there is clearly an association between excessive patient weight and fatigue failure of the femoral stem. We suggest avoiding, where possible, the insertion of small stems (particularly cemented stems) and large offset stems (particularly those with a modular neck) in overweight patients

Modular femoral stems for total hip arthroplasty (THA) were introduced to allow additional options for surgeons in controlling leg lengths, offset and implant stability. This option is widely used in our Region, where the study was conducted, having a modular neck stem nearly 35% of primary THA in 2013. Great majority of modular neck is made of Titanium alloy. The study was designed as a retrospective descriptive case series of 67 hips in patients who underwent revision of a THA. All had a Titanium modular neck. In 44 cases revision was due to breakage of the neck, in the remaining 23 it was due to different reasons unrelated to modular neck such as bone fracture, breakage of a ceramic component, cup loosening. Mean follow up was 3.5 yrs. For all patients excised capsule and surrounding tissue were graded for presence of necrosis, inflammatory exudate, lymphocytes, and wear particles using light microscopy of routine paraffin sections stained with hematoxylin and eosin. The retrieved modular neck-body and head-neck junctions were examined for evidence of fretting and corrosion. For some patient dosage of circulating Titanium was obtained. Approval was obtained from institutional review board. It resulted that a variable amount of wear was observed in the first group of patients, with no evidence of lymphocytic reaction, but with variable notes of necrosis. Broken necks showed different patterns of damage, with different degree of corrosion, beside the fatigue fracture. In the second group wear was less evident or absent and negativity of lymphocyte reaction was substantially confirmed. Circulating Titanium ions were one order of magnitude higher in first group (mean 35 micrograms /liter). It can be concluded that fracture of Titanium modular necks occurs progressively, wear does not induce lymphocytic reaction and circulating ions increase

Introduction. Highly crosslinked polyethylene (HXLPE) was clinically introduced approximately a decade and a half ago to reduce polyethylene wear rates and subsequent osteolysis. Clinical and radiographic studies have repeatedly shown increased wear resistance, however concerns of rim oxidation and fatigue fracture remain. Although short to intermediate term retrieval studies of these materials are available, the long-term behavior of these materials remains unclear. Methods. Between 2000 and 2015, 115 1st generation HXLPE acetabular liners implanted for 5 or more years were collected and analyzed as part of an ongoing, multi-institutional orthopaedic implant retrieval program. There were two material cohorts based on thermal processing (annealed (n=45) and remelted (n=70)). Each cohort was stratified into two more cohorts based on implantation time (5 – 10 years and >10 years). For annealed components, the intermediate-term liners (n=30) were implanted on average (±SD) for 7.3 ± 1.7 years while the long-term liners (n=15) were implanted for 11.3 ± 1.8 years. For remelted components, the intermediate-term liners (n=59) were implanted on average (±SD) for 7.2 ± 1.3 years while the long-term liners (n=11) were implanted for 11.3 ± 1.2 years. For each cohort, the predominant revision reasons were loosening, instability, and infection (Figure 1). Short-term liners (in-vivo <5ys) from previous studies were analyzed using the same protocol for use as a reference. For oxidation analysis, thin slices (∼200 μm) were taken from the superior/inferior axis and subsequently boiled in heptane for 6 hours to remove absorbed lipids that may interfere with the oxidation analysis. 3mm line profiles (in 100μm increments) were taken perpendicular to the surface at each region of interest. Oxidation indices were calculated according to ASTM 2102. Penetration was measured directly using a calibrated micrometer (accuracy=0.001mm). Results. The penetration rates for both the annealed and remelted cohorts were low and similar between the two material cohorts (Figure 2). There were several cases of fractured zirconia heads associated with a manufacturer recall that resulted in higher penetration rates. At the bearing and rim surfaces, the annealed liners had higher oxidation indices than the remelted components (p<0.001). For the remelted components, the intermediate-term liners had higher oxidation indices than the short-term liners (p=0.001). For the annealed liners, both the long-term and intermediate-term liners had higher oxidation indices compared with the short-term liners (p=0.007 and 0.001, respectively). Discussion. Thermally treated first generation HXLPEs were introduced to reduce polyethylene wear and prevent oxidative degradation. The results of this study suggest that both thermally treated HXLPEs demonstrate lower penetration rates than conventional polyethylene, however, the resistance to oxidation was formulation dependent. Specifically, the remelted components were more effective at preventing oxidation than the annealed liners. However, despite the lack of measurable free radicals, we were able to observe temporal changes in the oxidation of the remelted liners. Future work will include analysis of long-term 1stgeneration annealed HXLPE to fully assess its performance in the second decade of service

Background. The bearing surface is one of the important factors that affect the longevity of total hip replacement (THR). The ceramic on ceramic bearing decreases the rate of dislocation event and the amount of wear debris. We encountered cases of incomplete seating of the liner with the TriAD acetabular system. Patients and Methods. We examined 25 hips in 24 patients who had undergone total hip replacement by using the TriAD shell with a metal-backed alumina liner. We used the Hardinge approach for performing surgery in all patients. Incomplete seating was judged on the basis of plain anteroposterior and/or oblique radiographs obtained immediately and 3 months after the operation. Result. Six hips (24%) were found to have incomplete seating of the liner. Four cases were confirmed on the basis of plain radiographs obtained in the early postoperative period, and 2 were identified at a follow-up examination conducted more than 3 months postoperatively. All patients showed clinical improvement. Revision surgery was not required to rectify incomplete seating. Conclusions. We agreed with Langdown AJ. et al who reported that this implant design had an elevated rim and that shell deformity upon implantation can cause incomplete seating. Therefore, when using this implant, due care should be taken during implantation of the liner. It is necessary to conduct follow-up examination in patients with incomplete seating of the liner because these patients can have problems such as metallosis, corrosion, fatigue fracture of implants, and implant loosening

Introduction. In vivo, UHMWPE bearing surfaces are subject to wear and oxidation that can lead to bearing fatigue or fracture. A prior study in our laboratory of early antioxidant (AO) polyethylene retrievals, compared to gamma-sterilized and highly cross-linked (HXL) retrievals, showed them to be more effective at preventing in vivo oxidation. The current analysis expands that early study, addressing the effect of:. manufacturing-variables on as-manufactured UHMWPE;. in vivo time on these initial properties;. identifying important factors in selecting UHMWPE for the hip or knee. Methods. After our prior report, our IRB-approved retrieval laboratory received an additional 96 consecutive AO-retrievals (19 hips, 77 knees: in vivo time 0–6.7 years) of three currently-marketed AO-polyethylenes. These retrievals represented two different antioxidants (Vitamin E and Covernox) and two different delivery methods: blending-prior-to and diffusing-after irradiation cross-linking. Consecutive HXL acetabular and tibial inserts, received at retrieval, with in vivo time of 0–6.7 years (260 remelted, 170 annealed) were used for comparison with AO-retrievals. All retrievals were analyzed for oxidation and trans-vinylene index (TVI) using a Thermo-Scientific iN10 FTIR microscope. Mechanical properties were evaluated for 35 tibial inserts by uniaxial tensile testing using an INSTRON load frame. Cross-link density (n=289) was measured using a previously published gravimetric gel swell technique. Oxidation was reported as maximum ketone oxidation index (KOI) measured for each bearing. TVI was reported as the average of all scans for each material. Cross-link density and mechanical properties were evaluated as a function of both TVI and oxidation. Results. Minimal increase in oxidation was seen in these AO-retrievals, out to almost 7 years in vivo. In contrast, HXL-retrievals showed increasing KOI with time in vivo (annealed-HXL = 0.127/year, remelted-HXL = 0.036/year, p<0.001). HXL oxidation rate was higher in knees (0.091/year) than in hips (0.048/year), p<0.001. Cross-link density (XLD) correlated positively with TVI for both HXL (Pearson's correlation=0.591, p<0.001) and AO (Pearson's correlation=0.598, p<0.001) retrievals. AO-materials had higher TVI for the same or similar XLD than did HXL polyethylene. XLD correlated negatively with KOI for HXL retrievals (Pearson's correlation=−0.447, p<0.001). Mechanical properties varied by material across all materials evaluated, with tensile toughness correlating negatively with increasing TVI (Pearson Correlation=−0.795, p<0.001). Discussion. Irradiation cross-linking has been used effectively to improve wear resistance. Residual free radicals from irradiation are the target of AO-polyethylene, to prevent loss of UHMWPE XLD, resulting from in vivo oxidation of free radicals as seen in HXL retrievals, and toughness, resulting from oxidation or initial remelting. Despite different manufacturing variables, AO-polyethylene retrievals in this cohort had minimal oxidation and no change in XLD or toughness due to oxidation. However, toughness did vary with irradiation dose as did cross-link density. To achieve the same level of cross-linking as HXL-polyethylene required a higher irradiation dose in blended AO-polyethylene. AO-polyethylenes evaluated in this study had toughness that decreased with irradiation dose, but avoided loss of toughness due to remelting. Because AO-polyethylenes did not oxidize, they did not show the decrease of cross-link density, and potential loss of wear resistance, seen in HXL-polyethylene. For any figures or tables, please contact authors directly

Introduction. Arthrodesis is usually offered to patients in whom a two stage exchange arthroplasty has already failed or is likely to fail because of local factors (such as soft tissue damage, bone loss or poor perfusion), or because of systemic conditions which categorise the patient as a C-host (e.g. immune deficiency, diabetes and malnutrition). In other words arthrodesis is selected for patients with the worst prognosis. Method. I use an intramedullary nail extending from trochanter to just above the ankle which is locked distally only. The nail is curved with an arc of a 2 meter radius. This conforms to the shape of the femur and when passed through to the straight tibia it ends against the posterior cortex of the distal tibia where the bone is thickest. It creates an angle of between 9° and 11° of flexion at the knee. The nail is bent into 5° of valgus at the point where the femur and tibia meet. This allows the two bones to coapt, dynamise and unite. The procedure is performed in two stages. At the first every effort is made to eradicate the infection by debridement and appropriate local and systemic antibiotics. The nail is inserted at the second procedure and again every effort is made to deal with infection. If infection persists one can easily remove the nail when the knee has fused, and repeat the attempt to eradicate the infection in better circumstances. I have devised a scoring system in order to evaluate the eradication of infection based on clinical grounds, laboratory investigations and radiological examination. This allows for the fact that cure of an infection is not based on any one parameter. Results. I have performed such an arthrodesis in 99 patients. Fusion occurred in 74% of those who had more than six months follow-up. The affected limb was shortened on average by 4 cm. After nailing, pain was relieved in 80% of patients using a sliding scale. Using the scoring system, 31% were definitely cured of infection, 34.5% were intermediate and 34.5% definitely failed. 29 patients had their nail removed and the infection was re-addressed. Using the same evaluation system 12 (24%) were definitely cured, 12 (24%) had a probable cure and 5 (18%) remained infected. This gives an overall eradication of infection of 84%. In 4 patients apparent union of the knee broke down resulting in a jog of movement at the knee. Three of these patients were made comfortable with a gaiter to support the knee. One had his knee re-fixed with a long intramedullary nail. Three nails fractured in situ. In one of these patients the nail had locking screws proximally and distally which prevented dynamisation and union. In the other two non-union was apparent and the nail sustained a fatigue fracture. NO DISCLOSURES

Introduction. Total Hip Arthroplasty (THA) is currently one of the most widely performed surgical procedures in clinical orthopaedic practice. Despite the recorded number of uncemented implants has steadily increased in recent years, cemented fixation still remains the benchmark in THA, accounting for most of the procedures performed nowadays. The Friendly Short is a novel cemented short-stem that grants a less invasive and more bone conservative approach due to its shortened height and innovative cementing technique. It is indicated to treat elderly patients with the aim of preserving bone diaphysis while decreasing postoperative recovery times. Its instrument set allows to optimize the cement mantle thickness via an improved pressurization and stem centralization system. Objectives. Aim of this prospective study was to evaluate functional recovery and implant stability after THA with this cemented short-stem. Methods. Between June 2011 and October 2012, 96 consecutive patients (100 hips) underwent THA with the Friendly Short stem (Lima Corporate). All patients received DELTA-PF cups with UHMWPE cross-linked liners and CoCrMo femoral heads (Lima Corporate). A minimally invasive postero-lateral surgical approach was used in all cases. There were 60 women and 36 men, with a mean age and BMI of 72.6 ± 6.2 (59–85) years and of 26.6 ± 3.9 (18.7–35.6) kg/m2. Most patients were retired (87%) and led a moderately active lifestyle (79%). Underlying pathology was mostly primary coxarthrosis (94%), followed by aseptic necrosis (AVN) (4%) and post-traumatic osteoarthritis (2%). Radiographic and clinical evaluation (Harris Hip Score HHS, Oxford Hip Score OHS) were performed preoperatively, and postoperatively, at 45 days, and at 6, 12, and 24 months. Results. Mean HHS and OHS improved from 36.0 ± 11.3 (7–57) and 10.9 ± 4.9 (0–24) preoperatively, to 96.4 ± 6.1 (78–100) and 46.5 ± 3.1 (33–48) at 2 years. Most significant improvements were recorded already at 45 days after surgery, with a mean HHS of 78.6 ± 9.9 (27–100) and a mean OHS of 34.0 ± 7.4 (18–48). Despite old age, all patients reported remarkable early recovery, especially in terms of joint functionality [Mean flexion: preoperative 77.7 ± 11.1 (40–90), 101.7 ± 8.9 (70–110) at 45 days] and pain relief [Mean HHS pain domain: preoperative 9.6 ± 4.2 (0–20), 41.4 ± 3.6 (20–44) at 45 days); mean OHS pain sub-domain: preoperative 0.2 ± 0.5 (0–4), 3.4 ± 0.8 (1–4) at 45 days)]. X-rays demonstrated good implant stability thanks to optimal cement fixation; there was only 1 case of non-progressive 1-mm radiolucent lines, but no osteolytic areas, subsidence or loosening were observed. Absence of fatigue fractures in the cement mantle proved that there was good stress distribution. Acetabular cups were all stable: only 1 case of non-progressive 1-mm radiolucent lines was reported, but no case of either sclerosis or osteolysis was observed. No revision or implant failure occurred up to 2-year follow-up. Conclusions. Clinical and patient-subjective outcomes were very satisfactory, indicating a significant early functional recovery. Although longer follow-up is required, radiographic assessment demonstrated good implant stability already at 2 years as result of this innovative cementing technique

Background. Short stem has potential advantages of bone and muscle preservation. Current papers demonstrate that direct anterior approach (DAA) is a significant minimally invasive muscle-sparing approach to total hip arthroplasty. Theoretically, a short length stem with a reduced lateral shoulder is the most appropriate design for DAA. Objectives. To clarify the necessity of the standard length stem in tapered-wedge stem. Patients and methods. We prepared two kinds of tapered-wedge stem, Taperloc (standard length stem) and Microplasty (short stem) (Biomet, warsaw, Indiana) at the surgery. If the rasp for the short stem had not been fixed rigidly intra-operatively, it would have been changed to the standard length stem. Between May in 2010 and April in 2011, 94 patients (107 hips, 13 bilateral) were included in this study. All THAs were performed by direct anterior approach (DAA) on a standard surgical table. We analyzed the early clinical and radiographic results of 107 THAs in 94 patients (60 women, 34 men). The mean age was 61 (33∼84) years. The mean height was 161 (142∼182) cm and the mean weight was 63 (40∼92) kg. Results. All hips were implanted with the short stem. There was no need of the standard length stem. The mean operative time was 54 (28–140) minutes and the mean operative blood loss was 422 (60∼2400) ml. There was a significant improvement in functional outcome of these patients as measured by Japanese Orthopedic association hip scores. There were three complications intra-operatively or post-operatively. These were one intraoperative femoral fracture which was salvaged with circular wiring, one femoral fatigue fracture which occurred 6 weeks and cured conservatively, and one pulmonary embolism. There were no stem subsidence, dislocations and infections. Conclusion. This study confirms that there is no need of a standard length stem in THA using tapered-wedge stem. The short stem and DAA would be a winning combination for THA

Introduction. While advances in joint-replacement technology have made total ankle arthroplasty a viable treatment for end-stage arthritis, revision rates for ankle replacements are higher than in hip or knee replacements [1]. The questions asked in this study were (1) what retrieved ankle devices demonstrate about ankle arthroplasty failures, and (2) how do these failures compare to those seen in the hip and the knee?. Materials and Methods. An IRB-approved retrieval laboratory received retrieved polyethylene inserts and surgeon-supplied reason for revision from 70 total-ankles (7 designs, including five currently-marketed designs) from 2002 to the present. All retrievals were rated for clinical damage. Polyethylene inserts received six months or less after retrieval (n=45) were analyzed for oxidation using Fourier Transform Infrared (FTIR) spectroscopy, reported as maximum ketone oxidation index [2]. Insert sterilization method was verified using trans-vinylene index [3]. Oxidation measured in the 45 ankle inserts versus their time in vivo was compared to oxidation rates previously published for gamma-sterilized hip and knee polyethylene retrievals [6]. Statistical analysis was performed using IBM SPSS v.22. Results. The ankle devices were retrieved most commonly for loosening (n=22) followed by polyethylene fracture (n=9). These failure modes occurred after statistically different in vivo time (loosening: mean=4.4±3.6 years; polyethylene insert fracture: mean=9.5±4.1 years; p=0.002). Presence of clinical fatigue (cracking and/or delamination) was identified in 24 of the 70 retrieved inserts, and its presence correlated with in vivo time (Spearman's rho =0.449, p<0.001). Thirteen of these fatigued inserts were analyzed by FTIR. TVI analysis confirmed the sterilization method of the fatigued inserts: 12 gamma, 1 non-gamma sterilized. All 13 fatigued inserts had maximum ketone oxidation index (KOI) of 1.2 or higher. Presence of fatigue correlated with measured oxidation (Spearman's rho =0.685, p<0.001). Six of the 9 inserts that fractured in vivo were analyzed by FTIR. All were gamma-sterilized, and all had oxidation of 1.2 or higher. Oxidation rate determined for most of the 45 ankle inserts was at or above oxidation rates previously published for gamma-sterilized hip and knee polyethylene retrievals [6]. Discussion. This retrieval study concurs with the ankle arthroplasty literature that loosening is the most common reason for ankle revision [4]. Ankle inserts retrieved as a result of implant loosening had lower oxidation and no fatigue damage resulting from their shorter in vivo time. Fatigued and/or fractured inserts were in vivo for longer times, allowing more oxidation to occur. The effect of oxidation on polyethylene tensile strength and ductility has been reported for tibial inserts [5]. Oxidation above the critical value [5] has a dramatic effect on the ability of the polyethylene to resist fatigue damage and fracture, since the toughness of the polyethylene drops to near zero. All fatigued and fractured ankle inserts had oxidation that exceeded this critical oxidation. Most ankle inserts, whether gamma or non-gamma sterilized, oxidized at or above the oxidation rates previously published for gamma-sterilized hip and knee polyethylene retrievals [6]

Background. Titanium, in particular Ti6Al4V, is the standard material used in cementless joint arthroplasty. Implants are subjected to cyclic loading where fracture is the reason for re-operation in 1.5–2.4% of all revisions in total hip arthroplasty. In order to strengthen critical regions, surface treatments such as shot peening may be applied. A superficial titanium oxide layer is naturally formed on the surface as a protective film at ambient conditions. However, as its thickness is only in the range of several nanometers, it is prone to be destroyed by high loads - as present at the surface during bending - leading to an ‘oxidative wear’ in a corrosive environment [1]. The present study aims to evaluate the shot peening treatment on Ti6Al4V regarding its potential for cyclically loaded parts under a dry and a corrosive testing medium. Materials and Methods. Hour-glass shaped titanium specimens (Ti6Al4V) with a minimal diameter of 10 mm have been subjected to an annealing treatment at 620°C for 10h to remove initial residual stresses introduced during machining. Subsequently, a high-intensity shot peening treatment with cut wire followed by a low-intensity cleaning process with glass beads have been performed (Metal Improvement, Germany). Arithmetic mean roughness R. a. of the treated surfaces was measured (Mahr Perthometer M2, Germany). Residual stress depth profiles prior to and after shot peening have been measured by a Fe-filtered Co-K(alpha) radiation (GE Measurement&Control, USA) and calculated using the sin. 2. (psi) method. Fatigue strength has been determined by two servo-hydraulic hydropulsers (Bosch Rexroth, Germany) at 10 Hz and a load ratio of R=0.1 either under dry conditions (8 specimens) or surrounded by a 0.9-% saline solution (6 specimens) (BBraun, Germany) (Fig. 1). Testing has been performed until fracture occurred or the total number of 10 × 10. 6. cycles has been reached. All fracture surfaces have been analyzed after testing using FEG-SEM (Zeiss LEO 1530 VP Gemini, Germany). Results. Surface roughness increased significantly (p<0.01) after shot peening treatment from R. a, annealed. = 0.24 μm (±0.09 μm) to R. a, peened. = 2.02 μm (±0.16μm). Residual stresses have been introduced during shot peening up to a depth of 200μm with a maximum of 870 MPa at the surface (Fig. 2, left). All specimens showed clear signs of fatigue fracture after failure. Regarding fatigue strength, no differences have been observed between testing in saline solution or a dry environment (Fig. 2, right). Discussion. Shot peening has shown to significantly increase fatigue strength of a Ti6Al4V alloy after testing up to 10 × 10. 6. cycles. Thus, it seems to be an appropriate treatment for highly loaded components in cementless joint arthroplasty. In this context, a corrosive environment around a cyclically loaded implant does not seem to have any influence on their long term mechanical behaviour. However, it still needs to be clarified to which extend shot peening might decrease the risk of an early implant failure due to micro-motion between assembled parts (fretting) [2]

Acetabular cages are necessary when an uncemented or cemented cup cannot be stabilised at the correct anatomic level. Impaction grafting with mesh for containment of bone graft is an alternative for some cases in centers that specialise in this technique. At our center we use three types of cage constructs:. (A). Conventional cage ± structural or morselised bone grafting. This construct is used where there is no significant bleeding host bone. This construct is susceptible to cage fatigue and fracture. This reconstruction is used in young patients where restoration of bone stock is important. (B). Conventional cage in combination with a porous augment where contact with bleeding host bone can be with the ilium and then by the use of cement that construct can be unified. The augment provides contact with bleeding host bone and if and when ingrowth occurs, the stress is taken off the cage. (C). Cup Cage Construct – in this construct there must be enough bleeding host bone to stabilise the ultra-porous cup which functions like a structural allograft supporting and eventually taking the stress off the cage. This construct is ideal for pelvic discontinuity with the ultra-porous cup, i.e., bridging and to some degree distracting the discontinuity. If, however, the ultra-porous cup cannot be stabilised against some bleeding host bone, then a conventional stand-alone cage must be used. In our center the cup cage reconstruction is our most common technique where a cage is used, especially if there is a pelvic discontinuity

Acetabular cages are necessary when an uncemented or cemented cup cannot be stabilised at the correct anatomic level. Impaction grafting with mesh for containment of bone graft is an alternative for some cases in centers that specialise in this technique. At our center we use three types of cage constructs –. Conventional cage ± structural or morselised bone grafting. This construct is used where there is no significant bleeding host bone. This construct is susceptible to cage fatigue and fracture. This reconstruction is used in young patients where restoration of bone stock is important. Conventional cage in combination with a porous augment where contact with bleeding host bone can be with the ilium and then by the use of cement that construct can be unified. The augment provides contact with bleeding host bone and if and when ingrowth occurs, the stress is taken off the cage. Cup Cage Construct – in this construct there must be enough bleeding host bone to stabilise the ultra-porous cup which functions like a structural allograft supporting and eventually taking the stress off the cage. This construct is ideal for pelvic discontinuity with the ultra-porous cup, i.e., bridging and to some degree distracting the discontinuity. If, however, the ultra-porous cup cannot be stabilised against some bleeding host bone, then a conventional stand-alone cage must be used. In our center the cup cage reconstruction is our most common technique where a cage is used, especially if there is a pelvic discontinuity

Acetabular cages are necessary when an uncemented or cemented cup cannot be stabilised at the correct anatomic level. Impaction grafting with mesh for containment of bone graft is an alternative for some cases in centers that specialise in this technique. At our center we use three types of cage constructs –. (A). Conventional cage ± structural or morselised bone grafting. This construct is used where there is no significant bleeding host bone. This construct is susceptible to cage fatigue and fracture, This reconstruction is used in young patients where restoration of bone stock is important. (B). Conventional cage in combination with a porous augment where contact with bleeding host bone can be with the ilium and then by the use of cement that construct can be unified. The augment provides contact with bleeding host bone and if and when ingrowth occurs, the stress is taken off the cage. (C). Cup-Cage Construct – in this construct there must be enough bleeding host bone to stabilise the ultra-porous cup which functions like a structural allograft supporting and eventually taking the stress off the cage. This construct is ideal for pelvic discontinuity with the ultra-porous cup, i.e., bridging and to some degree distracting the discontinuity. If, however, the ultra-porous cup cannot be stabilised against some bleeding host bone, then a conventional stand-alone cage must be used. In our center the cup-cage reconstruction is our most common technique where a cage is used, especially if there is a pelvic discontinuity. Acetabular bone loss and presence of pelvic discontinuity were assessed according to the Gross classification. Sixty-seven cup-cage procedures with an average follow-up of 74 months (range, 24–135 months; SD, 34.3) months were identified; 26 of 67 (39%) were Gross Type IV and 41 of 67 (61%) were Gross Type V (pelvic discontinuity). Failure was defined as revision surgery for any cause, including infection. The 5-year Kaplan-Meier survival rate with revision for any cause representing failure was 93% (95% confidence interval, 83.1–97.4), and the 10-year survival rate was 85% (95% CI, 67.2–93.8). The Merle d'Aubigné-Postel score improved significantly from a mean of 6 pre-operatively to 13 post-operatively (p < 0.001). Four cup-cage constructs had non-progressive radiological migration of the ischial flange and they remain stable

Acetabular cages are necessary when an uncemented or cemented cup cannot be stabilised at the correct anatomic level. Impaction grafting with mesh for containment of bone graft is an alternative for some cases in centers that specialise in this technique. At our center we use three types of cage constructs –. (A) Conventional cage ± structural or morselised bone grafting. This construct is used where there is no significant bleeding host bone. This construct is susceptible to cage fatigue and fracture. This reconstruction is used in young patients where restoration of bone stock is important. (B) Conventional cage in combination with a porous augment where contact with bleeding host bone can be with the ilium and then by the use of cement that construct can be unified. The augment provides contact with bleeding host bone and if and when ingrowth occurs, the stress is taken off the cage. (C) Cup Cage Construct – in this construct there must be enough bleeding host bone to stabilise the ultra-porous cup which functions like a structural allograft supporting and eventually taking the stress off the cage. This construct is ideal for pelvic discontinuity with the ultra-porous cup, i.e., bridging and to some degree distracting the discontinuity. If, however, the ultra-porous cup cannot be stabilised against some bleeding host bone, then a conventional stand-alone cage must be used. In our center the cup cage reconstruction is our most common technique where a cage is used, especially if there is a pelvic discontinuity. Acetabular bone loss and presence of pelvic discontinuity were assessed according to the Gross classification. Sixty-seven cup-cage procedures with an average follow-up of 74 months (range, 24–135 months; SD, 34.3) months were identified; 26 of 67 (39%) were Gross Type IV and 41 of 67 (61%) were Gross Type V (pelvic discontinuity). Failure was defined as revision surgery for any cause, including infection. The 5-year Kaplan-Meier survival rate with revision for any cause representing failure was 93% (95% confidence interval, 83.1–97.4), and the 10-year survival rate was 85% (95% CI, 67.2–93.8). The Merle d'Aubigné-Postel score improved significantly from a mean of 6 pre-operatively to 13 post-operatively (p < 0.001). Four cup-cage constructs had non-progressive radiological migration of the ischial flange and they remain stable

Acetabular cages are necessary when an uncemented or cemented cup cannot be stabilised at the correct anatomic level. Impaction grafting with mesh for containment of bone graft is an alternative for some cases in centers that specialise in this technique. At our center we use three types of cage constructs –. (A) Conventional cage ± structural or morsellised bone grafting. This construct is used where there is no significant bleeding host bone. This construct is susceptible to cage fatigue and fracture. This reconstruction is used in young patients where restoration of bone stock is important. (B) Conventional cage in combination with a porous augment where contact with bleeding host bone can be with the ilium and then by the use of cement that construct can be unified. The augment provides contact with bleeding host bone and if and when ingrowth occurs, the stress is taken off the cage. (C) Cup Cage Construct – in this construct there must be enough bleeding host bone to stabilise the ultra-porous cup which functions like a structural allograft supporting and eventually taking the stress off the cage. This construct is ideal for pelvic discontinuity with the ultra-porous cup, i.e., bridging and to some degree distracting the discontinuity. If, however, the ultra-porous cup cannot be stabilised against some bleeding host bone, then a conventional stand-alone cage must be used. In our center the cup cage reconstruction is our most common technique where a cage is used, especially if there is a pelvic discontinuity