Introduction

Primary ankle arthroplasty (TAR) is increasingly used to treat end-stage ankle arthritis. Reported revision rates of TAR vary from 8.5% to 11.1% at 9 years. Revision surgery remains technically challenging with options ranging from simple joint debridement to tibio-talar-calcaneal fusion. The efficacy of these procedures remains unclear and there is no consensus on optimal revision options.

Precision medicine tailoring the patient pathway based on the risk, prognosis, and treatment response may bring benefits to the patients. To identify risk factors contributing to the early failure of treatment (development of events of interest) and when possible to change the prognosis via modifying these factors may improve the outcome and/or lower the risk of complications. There is an emerging goal to identify such parameters in total knee arthroplasty (TKA) thus lower the risk of revision surgery. The goal of this study was to identify factors explaining the risk for early revision of TKA using an artificial intelligence method appropriate for this task.

We applied a patient similarity network (PSN) for the identification of risk factors associated with early reoperations (n=109, 5.8%) in patients with TKA (n=1885). Next, an algorithm based on formal concept analysis was developed to support the patient decision on how to change modifying personal characteristics with respect to the estimated probability of reoperations.

The early reoperations were less frequent in women (4.4%, median time to reoperation 4.5 mo) than in men (8.2%, 10 mo), reaching the highest incidence in younger men (10.9%).

The purpose of this study is to compare 90-day costs and outcomes for primary total hip arthroplasty (THA) patients between a non-obese (BMI 18.5–24.9) versus overweight (25–29.9), obese (30–34.9), severely-obese (35–39.9), morbidly-obese (40–44.9), and super-obese (45+) cohorts.

We conducted a retrospective review of a prospective institutional database of primary THA patients from 2006–2013, including patients with a minimum of three-year follow-up. Thirty-three super-obese patients were identified, and the other five cohorts were randomly selected in a 2:1 ratio (total n = 363). Demographics, 90-day outcomes (costs, reoperations, and readmissions), and outcomes after three years (revisions and change scores for SF12, HHS, and WOMAC) were collected. Costs were determined using unit costs from our institutional administrative data for all in-hospital resource utilization. Comparisons between the non-obese and other groups were made with Kruskal-Wallis tests for non-normal data and chi-square and Fisher's exact test for categorical data.

The 90-day costs in the morbidly-obese ($13,134 ± 7,250 mean ± standard deviation, p <0.01) and super-obese ($15,604 ± 6,783, p <0.01) cohorts were statistically significantly greater than the non-obese cohorts ($10,315 ± 1,848). Only the super-obese cohort had statistically greater 90-day reoperation and readmission rates than the non-obese cohort (18.2% vs 0%, p <0.01 and 21.2% vs 4.5%, p=0.02, respectively). In addition, reoperations and septic revisions after 3 years were greater in the super-obese cohort compared to the non-obese cohort 21.2% vs 3.0% (p = 0.01), and 18.2% vs 1.5% (p= 0.01), respectively. There were no other statistical differences between the other cohorts with the non-obese cohort at 90-days or after 3 years. Improvements in SF12, HHS, and WOMAC were comparable in all cohorts.

The 90-day costs of a primary total hip arthroplasty for morbidly-obese (BMI 40–44.9) and super-obese (BMI>45) are significantly greater than for non-obese patients, yet these patients have comparable improvements in outcome scores. Health care policies, when based purely on the economic impact of health care delivery, may place morbidly-obese and super-obese patients at risk of losing arthroplasty care, thereby denying them access to the comparable quality of life improvements.

Purpose: To determine frequency of reoperations after definitive spinal fusion in patients with AIS and identify factors responsible

Methods and results: We undertook a retrospective review of surgical logs of patients with AIS who underwent surgical fixation during 1994–2004 and detailed case notes review of patients who required > 1 operation after definitive fusion. Results were compared according to approach used during primary operation.

We reviewed surgical logs of 310 patients who underwent instrumented spinal fusion for AIS. Approach at primary operation was anterior 101, posterior 109 and combined 100. Of these, 33 patients underwent 58 reoperations (10.6 %) after definitive fusion. Median age was 14.7 years; median follow up 5.4 years. Amongst these, primary operation was Anterior in 5 patients (7 reoperations, 5%), Posterior 13 patients (25 re-ops, 11.9%) and Combined 15 patients (26 re-ops, 15%). 12 patients required more than 1 reoperation.

Common indications were infection (9), failure of fixation either due to curve progression (10), junctional kyphosis (7) or pseudoarthrosis (3). 16 revisions were undertaken due to implant related symptoms. 5 patients with posterior instrumentation requested removal of implant. Only 1 patient had a neurological deficit that required removal of implant. 13 patients required secondary costoplasty.

Discussion: Risk of reoperation after definitive fusion in AIS is 10.6 % in our institution. Reoperation rates were maximal with combined approach and least with anterior approach (15% v 5%). Common indication with posterior instrumentation was implant related and in anterior surgery due to curve progression (wrong level fixation).

Ethics approval: Audit/service standard in trust number: 1236

Interest Statement: None

Antibiotic-impregnated cement is frequently used for fixation of total knee prostheses as a measure to prevent postoperative infection. In recent years, more cementless knee prostheses have been implanted especially for younger patients.

In 1997 to June 2004, 35044 primary total knee arthroplasties for primary or secondary osteoarthritis were performed in Finland and registered in nationwide arthroplasty register. The patients aged 70 years (range 21–96) on average, and 71.7% were women.

During the median follow-up of 39 months (range 0–104), 978 (2.8%) knees were revised. There were 188 (0.58%), 21 (1.09%) and 10 (1.18%) reoperations due to infection after cemented, hybrid and cementless arthroplasties, respectively (p=0.003). In hybrid arthroplasties with cemented tibial component, the septic reoperation rate did not significantly differ from cemented arthroplasties. Instead, the higher number of infections after hybrid arthroplasty was related to use of cementless tibial components (5.3% vs. 0.9%, p< 0.008). In Cox regression model adjusted for age, gender and diagnosis, the hazard ratio for septic reoperation after knee replacement with cementless tibial component was 2.4 (95% CI 1.4–4.1) compared to the cemented alternative. The fixation method did not affect the rate of septic reoperations occurring after the first postoperative year.

Cementless fixation of tibial component in primary total knee arthroplasty may associate with an increased risk of early septic reoperation. Until this finding is confirmed in other materials, cementless fixation in primary knee arthroplasty should be used cautiously in patients with increased risk for infection.

Aims

The aims of this study were to determine the rates of surgical complications, reoperations, and readmissions following herniated lumbar disc surgery, and to investigate the impact of sociodemographic factors and comorbidity on the rate of such unfavourable events.

Periprosthetic joint infections (PJI) are challenging complications following arthroplasty. Staphylococci are a frequent cause of PJI and known biofilm producers. Reoperations for PJI of the hip or knee between 2012 and 2015 performed at Sahlgrenska University Hospital were identified. Medical records were reviewed, and clinical parameters recorded for patients whose intraoperative bacterial isolates had been stored at the clinical laboratory. Staphylococcal strains isolated from reoperations due to first-time PJI were characterised by their ability to form biofilms using the microtiter plate test. The study group included 49 patients (70 bacterial strains) from first-time PJI, whereof 24 (49%) patients had recurrent infection. Strong biofilm production was significantly associated with recurrent infection. Patients infected with strong biofilm producers had a five-fold increased risk for recurrent infection. Strong biofilm production was significantly associated with increased antimicrobial resistance and PJI recurrence. This underscores the importance of determining biofilm production and susceptibility as part of routine diagnostics in PJI. Strong staphylococcal biofilm production may have implications on therapeutic choices and suggest more extensive surgery. Furthermore, despite the increased biofilm resistance to rifampicin, results from this study support its use in staphylococcal PJI

Essex-Lopresti injuries are often unrecognized acutely with resulting debilitating adverse effects. Persistent axial forearm instability may affect load transmission at both the elbow and wrist, resulting in significant pain. In the setting of both acute and chronic injuries metallic radial head arthroplasty has been advocated, however there is little information regarding their outcome. The purpose of this study was to assess the efficacy of a radial head arthroplasty to address both acute and chronic Essex-Lopresti type injuries. A retrospective review from 2006 to 2016 identified 11 Essex-Lopresti type injuries at a mean follow-up of 18 months. Five were diagnosed and treated acutely at a mean of 11 days (range, 8 to 19 days) from injury, while 6 were treated in a delayed fashion at a mean of 1.9 years (range, 2.7 months to 6.2 years) from injury with a mean 1.5 (range, 0 to 4) prior procedures. The cohort included 10 males with a mean age was 44.5 years (range, 28 to 71 years). A smooth stem, modular radial head arthroplasty was used in all cases. Outcomes included range of motion and radiographic findings such as ulnar variance, capitellar erosion, implant positioning and implant lucency using a modification of the method described by Gruen. Reoperations, including the need for ulnar shortening osteotomy, were also recorded. Three patients in each group (55%) reported persistent wrist pain. The mean ulnar variance improved from +5 mm (range, 1.8 to 7 mm) to +3.7 mm (range, 1 to 6.3 mm) at the time of final follow-up or prior to reoperation. Three (50%) patients in the chronic group underwent a staged ulnar shortening osteotomy (USO) to correct residual ulnar positive variance and to manage residual wrist pain. There were no reoperations in the acute group. Following USO, the ulnar variance in those three cases improved further to +3.5, +2.1, and −1.1 mm. No radial head prostheses required removal. Capitellar erosion was noted in five (45%) elbows, and was rated severe in one, moderate in two, and mild in two. Lucency about the radial head prosthesis stem was noted in eight (73%) cases, and rated as severe in 2 (18%), based on Gruen zones. Treatment of acute and chronic Essex-Lopresti lesions with radial head arthroplasty often results in persistent wrist pain. In the chronic setting, a planned USO was often necessary to restore axial forearm stability after radial head arthroplasty. Essex-Lopresti lesions represent a rare clinical entity that are difficult treat, particularly in the chronic setting. Early recognition and management with a smooth stem modular radial head arthroplasty may provide improved outcomes compared to chronic reconstruction

Femoroacetabular impingement (FAI) is a condition of the hip where there is a mismatch of the femoral head and hip acetabulum. This mismatch creates abnormal contact between the bones and causes hip pain which can lead to damage, and eventually osteoarthritis of the hip. The diagnosis and treatment of FAI has become one of the most popular clinical scenarios in orthopaedic surgery, with hip arthroscopy procedures increasing exponentially over the past five years. Surgical intervention usually involves correcting the existing deformities by reshaping the ball and socket (“osteoplasty” or “rim trimming”) so that they fit together more easily while repairing any other existing soft tissue damage in the hip joint (e.g. labral repair). Although correction of the misshaped bony anatomy and associated intra-articular soft tissue damage of the hip is thought to appease impingement and improve pain and function, the current evidence is based on small, observational, and low quality studies. A lack of definitive evidence regarding the efficacy of osteochondroplasty in treating FAI fueled the design and execution of the FIRST randomized controlled trial (RCT). FIRST evaluated the impact of surgical correction of the hip impingement morphology with arthroscopic osteochondroplasty versus arthroscopic lavage on pain, function, and quality of life in adults aged 18–50 years diagnosed with non-arthritic FAI at one year. FIRST was a large definitive RCT (NCT01623843) enrolling patients with FAI requiring surgical intervention across 11 international clinical sites. Participants were randomized to either arthroscopic osteochondroplasty (shaving of bone) or lavage (washing the joint of painful inflammation debris). The primary outcome was patient-reported pain within one year of the initial surgery measured using the Visual Analogue Scale (VAS). Secondary outcomes included function, health utility, and health-related quality of life using several general and hip-centric health questionnaires. An independent, blinded adjudication committee evaluated the quality of surgery, re-operations, and other patient complications. Patients and data analysts were blinded to the treatment groups. Two-hundred and twenty participants were enrolled into the FIRST trial over a six-year period (pilot phase: N=50, from 2012–2013 and definitive phase: N=170, from 2015–2018) at 11 clinical sites in Canada, Finland, and Denmark. The FIRST results will be released at the ISAKOS annual meeting as follows. The absolute difference in rate of pain reduction between groups was XX (95% CI: YY-YY, p=X). The mean differences of the Short-Form 12 (SF-12, MCS and PCS), Hip Outcome Score (HOS), International Hip Outcome Tool (iHOT-12), and EuroQol 5-Dimensions (EQ-5D) between groups are XX (95% CI: YY-YY, p=X)…, respectively. Reoperations occurred in XX of 220 (X%) patients over the one-year follow up period (OR:XX, 95% CI: YY-YY, p=X) and the patients treated with arthroscopic osteochondroplasty conferred the following risk of reoperation within one-year compared to arthroscopic lavage (RR:XX, 95% CI: YY-YY, p=X). This RCT represents major international efforts to definitively identify the optimal treatment strategy for FAI. The results of this trial will change practice, being used to prevent chronic hip pain and loss of function caused by hip osteoarthritis

Introduction. Infection following TKA can be a catastrophic complication that can cause significant pain, morbidity and jeopardize limb viability. The integrity of the soft tissue envelope is critical to successful treatment and infection control. While local tissue flaps can provide adequate coverage for most soft tissue defects around the knee, there are cases that require salvage using microvascular free tissue transfers. The purpose of this study is to evaluate the 1) rate of limb salvage; 2) infection control; and 3) clinical function following free flap coverage for salvage of the infected TKA. Materials and Methods. We retrospectively reviewed 23 microvascular free tissue transfers for management of soft tissue defects in infected TKA. There were 16 men and 7 women with a mean age of 61.2 years (range 39–81). The median number of procedures performed prior to soft tissue coverage was 5 (range 2–9) and all patients had failed at least one 2 stage reimplantation procedure. Clinical outcomes were measured using the Knee Society Scoring system for pain and function. The rate of limb salvage and infection control were recorded. Results. One patient was lost to follow up prior to 12 months. The remainder 22 patients were followed for a mean of 46 months (range 12–92 months). At latest follow up, 4 patients (18%) had undergone amputation for failure of treatment and persistent infection. For the remainder 18 patients, 11 patients (50%) have maintained a knee prosthesis in place while 7 patients had undergone resections for persistent infection but maintained their limbs (32%). Reoperations were common following coverage and reimplantation procedure. The median number of additional procedures was 2 (range 0–6). Clinical function was poor in patients who were reimplanted and retained a knee prosthesis following free flap coverage with a mean KSS score for pain and function of 44 (range 0–70) and 30 (range 0–65). All patients required an assistive device. Extensor mechanism problems and extensor lag requiring bracing were common following limb salvage and prosthesis reimplantation. Conclusions. Microvascular tissue transfer for management of infected TKA can be successful in limb salvage (81%) but clinical outcomes in salvaged limbs were poor. The data should be used to counsel patients when contemplating limb salvage in these severe, end-stage cases. For figures, tables, or references, please contact authors directly

Reoperations may be a better way of tracking adverse outcomes than complications. Repeat surgery causes cost to the system, and often indicate failure of the primary procedure resulting in the patient not achieving the expected improvement in pain and function. Understanding the cause of repeat surgery at the primary site may result in design improvements to implants or improvements to fusion techniques resulting in better outcomes in the future. The COFAS group have designed a reoperation classification system. The purpose of this study was to outline the inter and intra observer reliability of this classification scheme. To verify the inter- and intra-observer reliability of this new coding system, six fellow ship trained practicing foot and ankle Orthopaedic surgeons were asked to classify 62 repeat surgeries from a single surgeons practice. The six surgeons read the operation reports in random order, and reread the reports 2 weeks later in a different order. Reliability was determined using intraclass correlation coefficients (ICC) and proportions of agreement. The agreement between pairs of readings (915 for inter observer for the first and second read – 61 readings with 15 comparisons, observer 1 with observer 2, observer 1 with observer 3, etc) was determined by seeing how often each observer agreed. This was repeated for the 366 ratings for intra observer readings (61 times 6). The inter-observer reliability on the first read had a mean intra-class correlation coefficient (ICC) of 0.89. The range for the 15 comparisons was 0.81 to 1.0. Amongst all 1830 paired codings between two observers, 1605 (88%) were in agreement. Across the 61 cases, 45 (74%) were given the same code by all six observers. However, the difference when present was larger with more observers not agreeing. The inter-observer reliability test on the second read had a mean ICC of 0.94, with a range of 0.90. There were 43 (72%) observations that were the same across all six observers. Of all pairs (915 in total) there was agreement in 804 pairs for the first reading (88%) and disagreement in 111 (12%). For the second reading there was agreement in 801 pairs (86%) and disagreement in 114 (14%). The intra-observer reliability averaged an ICC value of 0.92, with a range of 0.86 to 0.98. The observers agreed with their own previous observations 324 times out of 366 paired readings (89% agreement of pairs). The COFAS classification of reoperations for end stage ankle arthritis was reliable. This scheme potentially could be applied to other areas of Orthopaedic surgery and should replace the Claiden Dindo modifications that do not accurately reflect Orthopaedic outcomes. As complications are hard to define and lack consistent terminology reoperations and resource utilisation (extra clinic visits, extra days in hospital and extra hours of surgery) may be more reliable measures of the negative effects of surgery

Reoperations may be a better way of tracking adverse outcomes than complications. Repeat surgery causes cost to the system, and often indicate failure of the primary procedure resulting in the patient not achieving the expected improvement in pain and function. Understanding the cause of repeat surgery at the primary site may result in design improvements to implants or improvements to fusion techniques resulting in better outcomes in the future. The COFAS group have designed a reoperation classification system. The purpose of this study was to outline the inter and intra observer reliability of this classification scheme. To verify the inter- and intra-observer reliability of this new coding system, six fellow ship trained practicing foot and ankle Orthopaedic surgeons were asked to classify 62 repeat surgeries from a single surgeons practice. The six surgeons read the operation reports in random order, and reread the reports 2 weeks later in a different order. Reliability was determined using intraclass correlation coefficients (ICC) and proportions of agreement. The agreement between pairs of readings (915 for inter observer for the first and second read – 61 readings with 15 comparisons, observer 1 with observer 2, observer 1 with observer 3, etc) was determined by seeing how often each observer agreed. This was repeated for the 366 ratings for intra observer readings (61 times 6). The inter-observer reliability on the first read had a mean intra-class correlation coefficient (ICC) of 0.89. The range for the 15 comparisons was 0.81 to 1.0. Amongst all 1830 paired codings between two observers, 1605 (88%) were in agreement. Across the 61 cases, 45 (74%) were given the same code by all six observers. However, the difference when present was larger with more observers not agreeing. The inter-observer reliability test on the second read had a mean ICC of 0.94, with a range of 0.90. There were 43 (72%) observations that were the same across all six observers. Of all pairs (915 in total) there was agreement in 804 pairs for the first reading (88%) and disagreement in 111 (12%). For the second reading there was agreement in 801 pairs (86%) and disagreement in 114 (14%). The intra-observer reliability averaged an ICC value of 0.92, with a range of 0.86 to 0.98. The observers agreed with their own previous observations 324 times out of 366 paired readings (89% agreement of pairs). The COFAS classification of reoperations for end stage ankle arthritis was reliable. This scheme potentially could be applied to other areas of Orthopaedic surgery and should replace the Claiden Dindo modifications that do not accurately reflect Orthopaedic outcomes. As complications are hard to define and lack consistent terminology reoperations and resource utilisation (extra clinic visits, extra days in hospital and extra hours of surgery) may be more reliable measures of the negative effects of surgery

INTRODUCTION. THA as primary treatment for displaced femoral neck fractures in elderly still remains a prominent concern. Overall dislocation rate after total hip arthroplasty (THA) is reported form 1∼5%. But, it is quiet different in situation of femur neck fracture in elderly. The THA is associated with higher rates of dislocation (8%∼11%) in eldery compared to hemiarthroplasty even though THA showed better clinical and functional scores. Recently resurgence about THA using DMC comes after improvement of manufacturing technology. The aim of this prospective multicenter study is to assess the rates of dislocation and re-operation for displaced femoral neck fractures in elderly with THA with Dual Mobility Cup (DMC) and to review systematically comparison of previous reports. Up to our knowledge, this is first report from asian conutry about the clinical outcomes THA using DMC for displaced femur neck fracture in elderly. METHODS. Prospective consecutive groups of patients treated for displaced femoral neck fractures by three surgeons at each three center were included. 131 hips underwent THA with DMC for acute displaced femoral neck fracture in patients aged older than 70 years. Data regarding rates of dislocation and re-operation were obtained by review of medical records. Additionally From 2009 which the US FDA first approved the DMC, the authors searched reports regarding to THA using DMC for displaced femur neck fracture in elderly using the MEDLINE including cases series and comparative studies with bipolar hemiarthroplasty and THA. Therefore, current report was compared with previous reports. RESULTS. The reports about THA using DMC for displaced femur neck fracture in elderly were limited. Most of them comes from European countries. Comparative study with THA from Sweden reported the dislocation rate of THA using DMC with average aged 75-year is 0%. In Denmark study, the bipolar hemiarthroplasty showed 14% of dislocation rate for femur neck fracture in patient aged 75 years but, THA using DMC is 4.6%. Two cases series from French reported about 1–4% in patients aged 80 years. In our multicenter study, dislocation occurred in 6/131 hips (4.6%) treated with total hip arthroplasty using DMC for displaced femur neck fracture over 70 years older patients. Reoperations including periprosthetic fracture and fixation failure of cup were required in 1/43 (2.3%) hips treated with total hip arthroplasty using DM cup. These result is comparable to European reports. DISCUSSION AND CONCLUSION. Our findings indicate that THA with DMC can not guarantee to prevent the dislocation for high risk elderly patients, but the overall rate of dislocation can be comparable to those of bipolar hemiarthroplasty and reduced compared to conventional total hip arthroplasty. This result might be a valuable messages for burden of the medical cost by dislocation after arthroplasty especially for older patient. Therefore, adding advnatages of THA compared with hemiarthroplasty, the THA with DMC can be a wise option for displaced femoral neck fracture in eldely. But, the randomized controlled study still is needed to clarify to confirm this findings

Introduction. Ceramic total knee arthroplasty (TKA) was introduced as a new-generation of knee prostheses in clinical practice, and are expected to reduce polyethylene wear due to its resistance to abrasion and lubrication. In 1992, we developed a cruciate retaining LFA-I total knee prosthesis (KYOCERA Medical Co., Japan), which comprises an alumina ceramic femoral component and a titanium-alloy tibial component with a polyethylene insert. The purpose of this study was to evaluate clinical results in rheumatoid patients who were treated with the alumina-ceramic LFA-I prosthesis with a minimum 15-year follow-up period. Methods. A total of 70 primary TKAs were performed in 51 patients between 1993 and 1996 using the cemented alumina-ceramic LFA-I prosthesis. Sixteen of these patients (20 knees) had died by the time of this study, of causes unrelated to the index arthroplasty, and 11 patients (16 knees) were lost to the follow-up. The remaining 34 knees were clinically and radiographically evaluated in the present study. The average follow-up time was 16.7 years. The average age of the patients was 58.2 years at the time of the operation. The clinical assessment was conducted with the Hospital for Special Surgery Knee rating score and the Knee Society scoring system. The component alignment and bone-implant interface were evaluated according to the Knee Society Roentgenographic Evaluation System. Results. The cumulative survival rate for revision for any reason at 15 years was 94.1%. The mean postoperative range of motion was 115.3 degrees at the time of the most recent follow-up. The mean postoperative knee score was 90.1 and 84.7 using the Knee Society and the Hospital for Special Surgery rating systems, respectively. Reoperations had been required on two knees due to loosening and on one knee due to infection. Periprosthetic radiolucencies or osteolysis were present in six knees. All lesions occurred around the prosthetic rim; 3 lesions at the anterior femoral flange, 5 lesions at the medial tibia, 2 lesions at the lateral tibia, and 1 lesion at the anterior tibia. These implants did not migrate, subside, or have circumferential radiolucencies that would indicate radiographic loosening. Discussion. In this series of patients with rheumatoid arthritis, the alumina-ceramic LFA-I prosthesis has performed well for the average 16.7 years of follow-up. It is not possible to draw any conclusions regarding the superiority of the ceramic prosthesis with respect to wear and survivability, however, the lack of a ceramic breakage with this anatomical design has encouraged us to continue to use this ceramic prostheses

Aims

Our primary aim was to assess reoperation-free survival at one year after the index injury in patients aged ≥ 75 years treated with internal fixation (IF) or arthroplasty for undisplaced femoral neck fractures (uFNFs). Secondary outcomes were reoperations and mortality analyzed separately.

Aims

Total hip arthroplasty (THA) is considered the preferred treatment for displaced proximal femoral neck fractures. However, in many countries this option is economically unviable. To improve outcomes in financially disadvantaged populations, we studied the technique of concomitant valgus hip osteotomy and operative fixation (VOOF). This prospective serial study compares two treatment groups: VOOF versus operative fixation alone with cannulated compression screws (CCSs).

Introduction. Reoperations to manage unstable total hip arthroplasty are reported with a high failure rate. The dual mobility cup (figure 1) (mobile polyethylene component between the prosthetic head and the outer metal shell) is a useful option in such cases. The purpose of this retrospective study was to assess the clinical and radiologic features associated with the dual mobility cup. Materials and Methods. Fifty one unstable total hip arthroplasties (32 females, 19 males) were revised using a dual mobility socket at our institution between March 2000 and February 2005. Mean age at reoperation was 67 year old (range, 35 to 98). The outcome of the revision procedure was assessed using the Harris Hip Score, and complications were determined by detailed review of the patient's records. Anteroposterior and lateral radiographs of the involved joint were reviewed to assess the position of the prosthesis and to look for osteolysis and signs of loosening of the implant. Results. Mean follow-up was 4 years (range, 2 to 6.7). At last review 4 patients had died and one was lost to follow up. Postoperatively there was a significant improvement of the Harris Hip Score. Fifty patients (98%) had no further episodes of dislocation. There were 3 revisions for deep infection, and 2 for dissociation of the bipolar component. No cup required a revision for aseptic loosening. No radiolucent lines around the components and no osteolysis were observed at latest follow up. Conclusion. The dual mobility cup is a highly effective option to manage unstable total hip arthroplasty. Unlike constrained devices, such components provide encouraging radiologic results regarding the potential for loosening and osteolysis. Longer follow up is needed to confirm these results

Zirconium total knee replacements theoretically have a low incidence of failure as they are low friction, hard wearing and hypo allergenic; we present the five year survival data. Data was collected prospectively from 212 patients who underwent Profix zirconium total knee replacements with an all-polyethylene tibial component. Revision surgery or a Knee Society Roentgenographic Evaluation System (KSRES) score of 10 or more was considered failure. SF 12 and WOMAC scores were recorded preoperatively, at three months, at one year, at three years and at five years. KSRES scores were recorded at all postoperative intervals. There were 92 male and 120 female patients with a median age of 63 years, range 25 to 87. 188 implants were for osteoarthritis and 24 were for rheumatoid arthritis. Eight patients died and six were lost to follow up, the remaining 198 patients reached a minimum of five year follow-up. At five years, the mean WOMAC score improved from 56 to 35 and the mean SF12 physical component score improved from 28 to 34. The mean SF12 mental component score remained unchanged at 51. The five year survival with failure due to implant related reasons was 99.5% (95% CI 97.3 - 100). This was due to one tibial component becoming aseptically loose in the first year. Reoperations excluded from this analysis were downsizing of the tibial component for stiffness and patella resurfacing. When these were included the five year survival was 98.1% (95% CI 95.1 - 99.3). Our results demonstrate that the Profix zirconium total knee replacement has a low medium term failure rate comparable to the best implants. Further research is needed to establish if the beneficial properties of zirconium improve long term implant survival

Reoperations for total hip arthroplasty instability are reported with high failure rates. The “dual mobility” socket is an attractive option in such cases. The goal of this retrospective study was to assess the clinical and radiographic features associated with such a design. Fifty four unstable total hip arthroplasties (35 females, 19 males) were revised using a “dual mobility” socket at our institution between March 2000 and June 2005. Mean age at reoperation was 66.5 year old (range, 35.7 to 98.7). Harris Hip Score was used to assess the revision procedures’ outcome, and complications were determined by detailed review of the patient’s records. Anteroposterior and lateral radiographs of the involved joint were reviewed to assess the position of the prosthesis and to look for osteolysis and signs of loosening of the implant. Mean follow-up was 4 years (range, 26 to 81 months). At last review 4 patients had died and one was lost to follow up. Postoperatively there was a significant improvement of the Harris Hip Score. Among the surviving patients, one (2%) redislocated and was successfully managed with closed reduction. This patient remained stable at latest follow-up. There were 3 revisions for deep infection, and 2 for dissociation of the bipolar component. Technical errors were found to be conducive to these dissociations. No cup required a revision for aseptic loosening. No radiolucent lines around the components and no osteolysis were observed at latest follow up. The “dual mobility” socket is a highly effective option to manage unstable total hip arthroplasty. Unlike constrained devices, such components did not raise any concern regarding the potential for loosening and for osteolysis. Longer follow up is needed to confirm these results

Introduction and aims. Recently many implants for ankle arthroplasty have been developed around the world, and especially some mobile bearing, three-component implants have good results. Nevertheless, at our institution fixed two-component, semi-constrained alumina ceramic total ankle arthroplasty (TAA) with TNK Ankle had been performed since 1991 and led to improved outcomes. We report clinical results and in vivo kinematic analyses for TNK Ankle. Method. Between 1991 and 2006, total ankle arthroplasties with TNK Ankle were performed with 102 patients (106 ankles) with osteoarthritis at our institution. There were 91 women and 11 men. The mean age was 69 years and mean follow-up was 5.4 years. These cases were evaluated clinically and radiographically. Besides in vivo kinematics, in TNK Ankle was analysed using 3D-2D model registration technique with fluoroscopic images. Between 2007 and 2008, prospectively ten TAA cases examined with fluoroscopy at postoperative one year. Results. In clinical results, excellent were 48 cases, good were 31 cases, fair were 10 cases, poor were nine cases, and death and loss to follow-up were 10 cases. Reoperations are performed on eight cases, one was arthrodesis, seven were talar component revision or talar revision with ceramic whole talus prosthesis. TNK Ankle have the rough surfaces by beadworks, and added surface treatment with hydroxyapatite granules, calcium phosphate paste or tissue engineered mesenchymal cells. Recently, only talar components were fixed with bone cement. Loosening has been more frequent in talar than tibial, whereas no reoperation was on cemented talar component cases. According to 3D-2D model registration, both components rotated a little each other and the contact region between both components variously sifted during weight bearing flexion of ankle. It was supposed that replaced position and angle of components concerned with the contact region. Conclusions. TAA with TNK Ankle have led to better results with improvement for surface treatments. Kinematics of ankle prostheses was derived by 3D-2D model registration, more appropriate position and angle to replace