Abstract. Introduction. Choosing a hinged implant in the revision knee arthroplasty (rTKA) setting is challenging and limited data on implant performance exists. We present the survivorship and reason for failure in rTKA performed at our institution using the LINK hinge prosthesis, predominantly the cemented modular Endo-Model prosthesis. Methodology. 260 consecutive revision knee cases performed between 2012 and 2020 were reviewed retrospectively. Mean follow up was 27 months (range 0 to 107). Survivorship was analysed in Stata using a Log Rank test to compare performance in patients stratified according to age (≥80 years old (76 cases), 70–79 years (104 cases) and ≤70 years (80 cases). Results. 53 patients died and 48/207 (23%) cases in 40 patients underwent re-revision. Reasons for re-revision were aseptic loosening (21), infection (12), instability (4), extensor failure (1), stiffness (1), fracture (1) and other (8). Loosening was seen in the femur (8), tibia (5), and both the femur and tibia (8). Sub-group analysis of patients according to age showed a significantly higher failure rate in younger patients (6 failures (8%) in patients ≥80, 27 failures (26%) in 70–79 and 15 (19%) in ≤70 (p = 0.02). Failure in patients ≤70 was predominantly due to aseptic loosening (8/15). Conclusion. Here we report a significantly higher rate of LINK hinge prostheses failure in patients <70 undergoing rTKA. Consent should consider the risk of re-revision in this patient group

Aim. Antimicrobial suppression has shown to significantly improve treatment success of streptococcal periprosthetic joint infection (PJI) compared to 12-week standard antimicrobial therapy, however, only short-term follow-up was investigated. In this study we assessed the impact of suppression on the long-term outcome of streptococcal PJI. Method. Consecutive patients with streptococcal PJI (defined by EBJIS criteria) treated 2009–2021 were prospectively included and allocated into standard and suppression (> 6 months) treatment group. Infection-free survival was assessed with Kaplan-Meier-method and compared between the groups with log rank test. Rates of infection-free, streptococcal infection-free and relapse-free status as well as tolerability of suppression were assessed. Results. Sixty-three PJI episodes (36 knee, 26 hip and one shoulder prosthesis) of patients with a median age of 70 (35–87) years were included. Twenty-seven (43%) were females. Predominant pathogens were S. agalactiae (n=20), S. dysgalactiae (n=18) and S. mitis/oralis (n=13). The main surgical procedures used were two-stage exchange (n=35) and prosthesis retention (n=21). Standard 12-week treatment was administered in 33 patients and suppression in 30 patients, of whom 10 had ongoing suppression and 20 had discontinued antibiotics at time of follow-up. Used oral antibiotics for suppression were amoxicillin (n=29), doxycycline (n=5) and clindamycin (n=2); 6 patients changed antibiotic substance due to side effects. The median follow-up time was 3.9 (0.3–13.3) years. Infection-free survival after 7.5 years was 38% with standard treatment and 62% with suppression (p=0.038). Of all failures, 52% (14/27) were due to streptococci. Suppression was effective in preventing streptococcal infection for the duration of antimicrobial treatment, however, after discontinuation relapses or new infections due to streptococci occurred in 5/20 (25%) patients and infection with any Streptococcus spp. was observed in 9/19 (47%) failures with standard treatment, 5/6 (83%) failures after discontinuing suppression and none during suppression. All failures in patients with ongoing suppression were caused by gram-negative rods. Conclusion. At long-term follow-up, the success rate was superior with suppression compared to standard treatment. Most failures after stopping suppression were caused by streptococci, whereas failures under suppression were caused by aerobic gram-negative rods

Background. A few patients undergoing a total hip replacement need a subsequent revision of the cup. In some of these cases, the treating surgeon may be confronted with Unexpected Positive Intraoperative Cultures (UPIC). The exact incidence of this finding is unclear. Moreover, it is unknown what the clinical outcome of these patients is when the stem is left in situ. The aim of our study was to describe the incidence of UPIC in patients undergoing cup revision and to determine the need for total revision in this patient group during follow-up. Methods/design. In this retrospective multicenter cohort study, we included all consecutive patients that underwent a cup revision between 2015–2017 and had a minimal follow-up of 2 years. Patients were divided in 3 cohorts: i) no positive intra operative cultures; ii) one UPIC; iii) two or more UPIC. Cases in whom 2 or fewer cultures were obtained during cup revision were excluded from the analysis. Results. From the 334 evaluated cases, 77 were excluded because an inadequate number of cultures were obtained. From the total of 257 included cases, the incidence of UPIC was 16% (n=39). 21 cases had one (8%), and 18 cases had two or more UPIC (7%). After two years of follow up, implant survival in the no UPIC group was 88% (95% CI 0.83 – 0.93), in the one UPIC group 95% (95% CI 0.86 – 1.0), and in the two or more UPIC group 77% (95% CI 0.57 – 0.97). Survival analysis showed no statistically significant differences between the cohorts as determined by cox regressive analysis and log rank test (P = 0.19). Conclusion. The incidence of UPIC in patients who undergo cup revision is relatively high but does not seem to have a major influence on the need for total revision of the hip during a follow-up of 2 years

Open debridement and Outerbridge and Kashiwagi debridement arthroplasty (OK procedure) are common surgical treatments for elbow arthritis. However, the literature contains little information on the long-term survivorship of these procedures. The purpose of this study was to determine the survivorship after elbow debridement techniques until conversion to total elbow arthroplasty and revision surgery. We performed a retrospective chart review of patients who underwent open elbow surgical debridement (open debridement, OK procedure) between 2000 and 2015. Patients were diagnosed with primary elbow osteoarthritis, post-traumatic arthritis, or inflammatory arthritis. A total of 320 patients had primary surgery including open debridement (n=142) and OK procedure (n=178), and of these 33 patients required a secondary revision surgery (open debridement, n=14 and OK procedure, n=19). The average follow-up time was 11.5 years (5.5 - 21.5 years). Survivorship was analyzed with Kaplan-Meier curves and Log Rank test. A Cox proportional hazards model was used assess the likelihood of conversion to total elbow arthroplasty or revision surgery while adjusting for covariates (age, gender, diagnosis). Significance was set p<0.05. Kaplan-Meier survival curves showed open debridement was 100.00% at 1 year, 99.25% at 5 years, and 98.49% at 10 years and for OK procedure 100.00% at 1 year, 98.80% at 5 years, 97.97% at 10 years (p=0.87) for conversion to total elbow arthroplasty. There was no difference in survivorship between procedures after adjusting for significant covariates with the cox proportional hazard model. The rate of revision for open debridement and OK procedure was similar at 11.31% rand 11.48% after 10 years respectively. There were higher rates of revision surgery in patients with open debridement (hazard ratio, 4.84 CI 1.29 – 18.17, p = 0.019) compared to OK procedure after adjusting for covariates. We also performed a stratified analysis with radiographic severity as an effect modifier and showed grade 3 arthritis did better with the OK procedure compared to open debridement for survivorship until revision surgery (p=0.05). However, this difference was not found for grade 1 or grade 2 arthritis. This may suggest that performing the OK procedure for more severe grade 3 arthritis could decrease reoperation rates. Further investigations are needed to better understand the indications for each surgical technique. This study is the largest cohort of open debridement and OK procedure with long term follow-up. We showed that open elbow debridement and the OK procedure have excellent survivorship until conversion to total elbow arthroplasty and are viable options in the treatment of primary elbow osteoarthritis and post traumatic cases. The OK procedure also has lower rates of revision surgery than open debridement, especially with more severe radiographic arthritis

Open debridement and Outerbridge and Kashiwagi debridement arthroplasty (OK procedure) are common surgical treatments for elbow arthritis. However, the literature contains little information on the long-term survivorship of these procedures. The purpose of this study was to determine the survivorship after elbow debridement techniques until conversion to total elbow arthroplasty and revision surgery. We performed a retrospective chart review of patients who underwent open elbow surgical debridement (open debridement, OK procedure) between 2000 and 2015. Patients were diagnosed with primary elbow osteoarthritis, post-traumatic arthritis, or inflammatory arthritis. A total of 320 patients had primary surgery including open debridement (n=142) and OK procedure (n=178), and of these 33 patients required a secondary revision surgery (open debridement, n=14 and OK procedure, n=19). The average follow-up time was 11.5 years (5.5 - 21.5 years). Survivorship was analyzed with Kaplan-Meier curves and Log Rank test. A Cox proportional hazards model was used assess the likelihood of conversion to total elbow arthroplasty or revision surgery while adjusting for covariates (age, gender, diagnosis). Significance was set p<0.05. Kaplan-Meier survival curves showed open debridement was 100.00% at 1 year, 99.25% at 5 years, and 98.49% at 10 years and for OK procedure 100.00% at 1 year, 98.80% at 5 years, 97.97% at 10 years (p=0.87) for conversion to total elbow arthroplasty. There was no difference in survivorship between procedures after adjusting for significant covariates with the cox proportional hazard model. The rate of revision for open debridement and OK procedure was similar at 11.31% rand 11.48% after 10 years respectively. There were higher rates of revision surgery in patients with open debridement (hazard ratio, 4.84 CI 1.29 - 18.17, p = 0.019) compared to OK procedure after adjusting for covariates. We also performed a stratified analysis with radiographic severity as an effect modifier and showed grade 3 arthritis did better with the OK procedure compared to open debridement for survivorship until revision surgery (p=0.05). However, this difference was not found for grade 1 or grade 2 arthritis. This may suggest that performing the OK procedure for more severe grade 3 arthritis could decrease reoperation rates. Further investigations are needed to better understand the indications for each surgical technique. This study is the largest cohort of open debridement and OK procedure with long term follow-up. We showed that open elbow debridement and the OK procedure have excellent survivorship until conversion to total elbow arthroplasty and are viable options in the treatment of primary elbow osteoarthritis and post traumatic cases. The OK procedure also has lower rates of revision surgery than open debridement, especially with more severe radiographic arthritis

Background. Total hip arthroplasty (THA) is increasingly used for active patients with displaced intracapsular hip fractures. Dislocation rates in this cohort remain high postoperatively compared to elective practice, yet it remains unclear which patients are most at risk. The aim of this study was to determine the dislocation rate for these patients and to evaluate the contributing patient and surgeon factors. Methods. A five-year retrospective analysis of all patients receiving THA for displaced intracapsular hip fractures from 2013–18 was performed. Data was collected from the institutions' hip fracture database, including data submitted to the National Hip Fracture Database (NHFD). Cox regression analysis and log-rank tests were implemented to evaluate factors associated with THA dislocation. Patient age, sex, ASA grade, surgeon seniority, surgical approach, femoral head diameter and acetabular cup type were all investigated as independent factors. Results. A total of 196 patients, with a mean age of 72 (range 49–90), received THA for hip fracture between 2013–18. A posterior approach, using standard cemented acetabular components and a 28mm femoral head, was used in 133 cases (72%). Fourteen dislocations (7%) were observed during this period, with 5 patients requiring revision surgery. Of these dislocations, all were performed through posterior approaches with standard cemented cups. 28mm femoral heads were used in all cases except one, which used a 32mm femoral head. In Cox regression analysis, ASA grade, but not age or sex, was significantly associated with dislocation (hazard ratio = 4.5; 95% confidence interval 2.0–10.0; p<0.001). On log rank testing no statistically, significant association was found between dislocation and surgeon grade (p=0.85), surgical approach (p=0.31), femoral head size (p=0.85) or cup type (p=0.30). Discussion. This study demonstrates an increased risk of dislocation following THA for hip fracture with higher ASA grades. It may be appropriate to offer more stable implants to this cohort of patients

Introduction. Prior to the introduction of alternative bearing surfaces, patients were typically counseled to expect that their total hip arthroplasty (THA) using conventional polyethylene would last for 10 years. With the introduction of crosslinked polyethylene and hard-on-hard bearing surfaces, revisions related to bearing surface wear were expected to decrease. We examined six different bearing surfaces used at our institution over three decades to evaluate how the overall survivorship, reasons for revision and Harris Hip Scores have changed with time. Methods. We identified six cohorts of patients with 754 primary hips done between 1983 and 2007. With the exception of 81 Birmingham hip resurfacings (BHR), all femoral components were straight, extensively porous-coated cylindrical (EPC) stems (AML and Prodigy). All cups were porous coated. In addition to the BHRs, the bearing surfaces included 223 conventional polyethylene (CPE) in a non-modular shell, 114 CPE in a modular shell, 116 crosslinked polyethylene (XLPE), 130 metal-on-metal (MOM), and 90 ceramic-on-ceramic (COC). The mean follow-up for all hip replacements is 13.0±6.0 years. Kaplan-Meier survivorship using revision for any reason as an endpoint with log rank testing was used to evaluate differences among groups. Results. Although there were no differences in survivorship at 10-year follow-up among the groups (p=0.53), the XLPE liners demonstrated improved survivorship at 15-years compared to both CPE groups owing to the absence of wear-related revisions (97% versus 83% for non-modular and 85% for modular cups respectively, p=0.001 and p=0.008). Revisions for femoral loosening have only occurred among 0.6% (4/673) of EPC stems. Revisions for cup loosening have occurred among 4% (10/223) of the non-modular cups but there are none among the other groups. The incidence of dislocation was reduced with the MOM, BHR and COC bearings that used 36-mm or larger femoral heads compared to the THAs that used 28-mm or 32-mm heads [1.1 % (3/261) versus 5.1% (25/493), p<0.01]. Infection has led to revision among 2 THAs with CPE in non-modular cups (0.9%), 2 MOM (1.5%), and 2 COC (2.2%). At 10-year follow-up, Harris Hip Scores tended to be higher among the BHRs compared to the other groups (92.1 versus 82.9, p<0.01). Discussion. The introduction of XLPE has eliminated wear-related revisions through 15-year follow-up. Hard-on-hard bearing surfaces are performing relatively well but differences are not yet discernable compared to CPE. Dislocation incidence has been reduced with the introduction of larger diameter heads but remains a persistent concern. Infection continues to occur although the incidence remains low. For any tables or figures, please contact the authors directly

Introduction. Total knee arthroplasty (TKA) is a successful treatment for degenerative end stage knee arthritis. Younger patients who undergo TKA may face multiple revisions during their lifetime due to aseptic loosening, infection, and instability. The purpose of this study was to compare the early complication rates and revision free survivorship between age groups undergoing TKA in a nationwide database. Methods. The PearlDiver national insurance database was queried from 2007–2015 for all patients who underwent primary TKA. Kaplan-Meier Curve survival analysis and log rank test were performed to evaluate revision rates between age groups (<40, 40–49, 50–59, 60–69, 70–79, 80–89, and ≥90 years). Complication rates were compared to rates in the age 60–79 group using multiple logistic regressions controlling for baseline demographics and comorbidities. Results. There were 114,698 patients included in the analysis. Patients under age 40 years had higher rates of diabetes mellitus, inflammatory arthritis, drug abuse, and smoking status compared to the rest of the cohort (p<0.001). After controlling for baseline comorbidities using multiple logistic regressions, patients under age 40 and those age 40–49 had an increased rate of early mechanical complications (OR 2.84, p=0.01 and 2.95, p<0.001 respectively). 90-day readmission rates were significantly higher in the under age 40 group (OR 1.63, p=0.03). Revision free survivorship at 5 years was significantly worse in patients less than 60 years of age (77.2% in age <40 group, 88.9% in age 40–49 group, and 91.7% in age 50–59 group, p<0.01). Conclusions. Young patients under 40 years of age had a higher risk of early revision after TKA with 77% revision free survivorship at 5 years. Additionally, these patients have an increased risk of mechanical complications and readmission at 90 days. These outcomes may be used to shape preoperative counseling for the young patient

Introduction. Reverse hybrid total hip replacement (THR) offers significant theoretical benefits but is uncommonly used. Our primary objective was to evaluate implant survival with all cause revision and revision for aseptic loosening of either component as endpoints. Patients/Materials & Methods. Data was collected prospectively on 1, 088 (988 patients) consecutive reverse hybrid THRs. Mean patient age was 69.3 years (range, 21–94) and mean follow-up was 8.2 years (range, 5–11.3). No patients were lost to follow-up. Overall, 194 (17.8%) procedures were performed in patients under 60 years, 666 (61.1%) were performed in female patients and 349 (32.1%) were performed by a trainee. Acetabular components were ultra-high molecular weight polyethylene in 415 (38.1%) hips, highly cross-linked polyethylene in 669 (61.5%) hips and vitamin E stabilised polyethylene in 4 (0.4%) hips. Femoral stems were collared in 757 (69.7%) hips and collarless in 331 (30.3%) hips. Femoral head sizes were 28 mm in 957 (87.9%) hips and 32 mm in 131 (12.1%) hips. Survival analysis was performed using Kaplan Meier methodology. Log rank tests were used to asses differences in survival by age, gender, head size and surgeon grade. Results. Ten-year implant survival (122 hips at risk) was 97.2% (95% CI 95.8–98.1%) for all cause revision (Figure 1), 100% for aseptic acetabular loosening and 99.6% (95% CI 99.0–99.9%) for aseptic stem loosening (Figure 2). There was no difference in implant survival by age (p = 0.39), gender (p = 0.68), head size (p = 0.76) or surgeon grade (p = 0.20) for all cause revision. There was no difference in survival by gender (p = 0.12), head size (p = 0.38) or surgeon grade (p = 0.76) for stem revision. Four (0.4%) stems failed at mean 2.5 years (range, 0.6–4.8) because they were undersized. These were associated with patient age under 60 years (p = 0.015). Discussion. This is the largest reported study on the outcomes of reverse hybrid THR in a consecutive series of patients at medium to long term follow-up. Cemented acetabular components are less costly than uncemented cups and offer other significant benefits such as improved fixation in osteoporotic or pathological bone, reduced risk of intraoperative periprosthetic fracture, easier revision and local antibiotic delivery which can reduce deep infection rates. Advantages of uncemented stems over cemented stems include biological fixation, shorter operating times, fewer adverse pulmonary events and reduced proximal stress shielding. Our results indicate high implant survival rates at ten-year follow-up with low rates of aseptic loosening (0.4%). Meticulous surgical technique is required to avoid stem undersizing which may lead to early failure particularly in younger patients. Conclusion. This study confirms that reverse hybrid THR offers highly successful outcomes, irrespective of age, gender, head size and surgeon grade. For any figures and tables, please contact the authors directly

Purpose. To investigate the prognostic effect of surgical margins in soft tissue sarcoma on Local Recurrence (LRFS), Metastasis (MFS) and Disease Free Survival (DFS). Patients and Methods. This is a retrospective, single center study of 105 consecutive patients operated with curative intent. Quality of surgery was rated according to the International Union Against Cancer classification (R0/R1) and a modification of this classification (R0M/R1M) to take into account growth pattern and skip metastases in margins less than 1mm. Univariate and multivariate analysis was done to identify potential risk factors. Kaplan-Mayer estimated cumulative incidence for LRFS, MFS and DFS were calculated. Survival curves were compared using Log rank tests. Results. Estimated LRFS was 0.64 [0.52;0.76] at 5 years following R1 surgery, 0.9 [0.85;0.95] following R0 (p=0.023), 0.64 [0.519;0.751] following R1M surgery and 0.92 [0.87;0.96] following R0M (p=0.01). The R status was associated with DFS (p=0.028), but not MFS (p=0.156). The RM status was associated with both outcomes (p=0.001 and p=0.007). Multivariate analysis showed an independent association with LRFS for RM status (HR 6.77 [1.78–25.7], p=0.005), with DFS for RM status (HR 2.83 [1.47–5.43], p=0.001) and Grade (HR=3.17 [1.38–7.27], p=0.003) and with MFS for Grade (HR=3.96 [1.50–10.5], p=0.006). Conclusions. In Soft Tissue Sarcoma, surgical margins are the strongest prognostic factor for LRFS. In this study, taking growth pattern and skip metastases into account for margins less than 1mm increased prognostic significance of surgical margins for LRFS, DFS and MFS

Aims: To asses the outcome of the knee arthroplasty in patients under 55 years old. Methods: 59 knees were performed in patients who were 55 years old and above between 1976 and 1990. No patient was lost to follow-up. The assessment was done using the Knee Society scoring systems. Survivorship analysis was done using the Kaplan-Meier method and analysed with log rank test. Results: The average age at surgery was 48 (19–55) years. There were 25 male and 34 female. Osteoarthrosis was diagnosis in 38 knees and 21 had rheumatoid arthritis. All living patients had a minimum of 10 years (10–23) of follow up. Failure occurred in five (8.4%). 82% of patients had complete pain relief and 91% the knee had excellent knee score (of more than 85) at the final follow up. Survivorship analysis showed implant survival of 90% at 15 years, and 75% at 23 years for revision as end point. Diagnosis had no significant effect on the survivorship (p=0.66). Conclusions: The conventional total knee arthroplasty provides in this young group of patients with excellent clinical results and moderate survivorship analysis for 23 years follow-up

Aim: The purpose of this study is to evaluate the longest results of Total Condylar knee arthroplasty. Material: Between 1976 and 1982, 159 consecutive primary total knee replacements were performed. All knees were followed in prospective fashion. Assessment was done by Knee Society methods. Survivorship analysis was done using the Kaplan-Meier method and analysed with log rank test. Results: No patient was lost to follow-up. One hundred three knees lost to natural cause (death), while 56 knees were available at þnal follow-up with their average of 20 years (19 to 24 years). The average age of follow-up was 65 years. 57 knees were done in male and 102 knees were in female. Revision surgery was carried out in 7 knees (4.4%). 90% of living patients were pain free. 90% had excellent knee score while only 10% had excellent function. 24 years survivorship was 89% (77 to 95%) for endpoint of revision surgery. Conclusions: Total Condylar knee arthroplasty provides excellent pain relief and knee score with only moderate improvement in the functional status. Total Condylar knee arthroplasty continues to be gold standard in total knee arthroplasty. This is longest reported results of Total Condylar knee arthroplasty

Aim: To analyze results of flat on flat geometry with posterior retaining arthroplasty. Materials: 469 knees were performed in patients between 1988 and 1990 done by one surgeon and followed prospectively. Survivorship analysis and log rank test were done. Assessment was done with Knee Society evaluation system. Results: The average age at surgery was 70 years. No patient was lost to follow-up. 294 were done in males and 175 in females. Osteoarthrosis was diagnosis in 445 knees (94.2%) and rheumatoid arthritis in 24 knees (5.8%). The average follow up was 10.2 years. All living patients had a minimum of 10 years of follow up. There was significant improvement in the knee score, function score and range of motion following surgery. Failure occurred in eight knees (1.7%). The survivorship analysis showed cumulative survivor of implant was 99.4% at 14 years (CI- 97.1% to 99.8%). Gender, age at surgery, and diagnosis were not significant factor in outcome. Conclusions: The geometry of flat on flat design continues to work satisfactory despite the retention of posterior cruciate at follow-up of 10 years. Results compares well reported results of more conforming designs knee arthroplasty during the same period

Alveolar Rhabdomyosarcoma (RMA) are characterised by chromosomal translocations fusing the PAX3 or PAX7 gene with FKHR in ~85%. Previous studies have suggested that PAX3/7-FKHR fusion types are related to prognosis. In order to prove these findings we performed a retrospective analysis of the PAX-FKHR fusion status and its relation to outcome in patients treated in the CWS trials. Between 1986 and 2004, out of 446 RMA patients treated in four consecutive CWS trials (CWS-86, -91, -96 or -2002-P), tumor samples from 121 patients with adequate quality for analysis of PAX-FKHR fusion status by RT-nested PCR were available. Survival analysis depending on clinical risk factors and fusion status was performed using the Kaplan-Meier Method, the log rank test and the Cox regression model. There were no major differences in distribution of known risk factors in the analysed cohort of 121 patients compared to all patients enrolled in the CWS trials. PAX-FKHR fusions were detected in 83%: 72 PAX3-, 29 PAX7-FKHR fusions. Patients with PAX3-FKHR positive tumors more often showed a pattern of adverse clinical risk factors (age > 10 years, primary metastases, lymph node involvement) than the PAX7-FKHR positive group. The 5-year event free survival rate of patients with initially metastatic tumors positive for either of the two fusion transcripts was significantly lower compared with the fusion transcript negative cohort and the non-analysed RMA patients. There was no significant outcome difference between patients with PAX3-FKHR and PAX7-FKHR positive tumors in uni- and multivariate analysis. In the present analysis, which is to our knowledge the largest reported so far, PAX-FKHR fusion type was no significant predictor for prognosis, thus not supporting results of previous studies

Aims

The aim of this study was to investigate the association between fracture displacement and survivorship of the native hip joint without conversion to a total hip arthroplasty (THA), and to determine predictors for conversion to THA in patients treated nonoperatively for acetabular fractures.

Purpose: Acetabular revision has become a challenging situation due to the importance of bone stock loss encountered in SOFCOT stage III acetabula. The number of failures due to loosening are explained by the strong mechanical stress on the bone grafts or inadequate restitution of the rotation centre of the hip. The purpose of this study was to evaluate mid-term results of the Kerboull support used to achieve anatomic recentring of the hip and progressive weight bearing on the bone grafts. Material and methods: This retrospective series included 54 acetabular revisions performed for stage III loosening between 1989 and 1996. A Kerboull support was used in all cases. The patients were assessed with the Postel Merle d’Aubigné score and radiographically on plain pelvis films in order to search for recurrent loosening or arthroplasty failure. The log rank test was used to compare actuarial survival. Results: The series included 62% women. Mean age was 62.3 years (33–87). This was the first revision for 78% and a second or more revision for 22%. The preoperative Postel Merle d’Aubligné score was 9.18 points. This score was 12.3 postoperatively, 15.6 at one year, 15.5 at five years and 14.8 at last follow-up. Dislocation was the most frequent complication, with 55% occurring on cups more than 46° oblique. Grafts were considered radiographically integrated in 58% of the cases. There were 5.5% failures due to migration, 13.8% due to fracture of the superior screw. The actuarial survival was 97.4% at three years, 94.7% at four years, 89.2% at five years and 73% at seven and ten years. Conclusion: On the basis of these good short-, mid- and long-term clinical and radiographic results, we recommend Kerboull support for the treatment of stage III acetabular loosening

Aims: Analyze the long-term survival of cementless meniscal bearing total knee arthroplasty (TKA). Methods: Two hundred and thirty-two consecutive cementless primary meniscal bearing Low Contact Stress TKA were performed on 203 patients in our institution from November 1988 to June 1996. The diagnosis was osteoarthritis in 192 knees (83%) and rheumatoid arthritis in 40 cases (17%). Mean age at surgery was 66.5 years (range:16–90). Cruciate retaining prosthesis was implanted in 81% and a cruciate sacrificing prosthesis in 19%. Twenty patients died and ten patients (4,3%) were lost to follow-up. The remaining 202 knees (87%) had an average follow-up of 116.7 months (range:70–165). Survival analysis was done using as end point revision surgery or recommended revision. Results: Twenty-six TKAs (11.2%) required revision: infection (3), patelar failure (2), tibial/femoral loosening (2) and polyethylene failure (19). Age, gender, diagnosis and sacrificing cruciate ligaments were not related with prosthesis failure (p> 0.05). The Kaplan-Meier survival analysis showed a mean of 155 months (95%CI:150–159). The life table survival estimate at 10 years was 90.4% (85–95). The cumulative survival rate for patellar failure was 99% (98–100), for mechanical loosening 99% (98–100) and 91.3% (87–96) for polyethylene failure. The Log Rank Test was significant for poliethylene failure (p=0.0005). Conclusions: In our experience overall long-term survival of cementless meniscal bearing TKAwas acceptable. Mobile bearing knee prosthesis satisfactorily resolved problems related with patellar failure or tibial/femoral loosening. Polyethylene failure continues to be the main problem in long-term survival of knee prosthesis

Purpose: Matrix metalloproteinases are important for matrix turnover in development of metastasis and angiogenesis. Our purpose was to investigate the expression of MMP-9 and itsb prognostic significance in knee osteosarcomas. Patients: 55 patients with osteosarcoma IIB of the knee area have been studied with respect to the expression of MMP-9 in the surviving tumour cells in the surgical resection specimens. Patients were followed up for at least two and a half years. Methods: We studied the MMP-9 expression in the resection specimens using immunohistochemistry. The importance of the prognostic factors was assessed using single (log rank test) and multiple variable (Cox regression) analysis. Independence between the factors found significant using the log rank test was studied using the yf test. Significance was set at P< 0.05. Results: On single variable analysis factors significantly associated with poor survival were high alkaline phosphatase at diagnosis and tumour cells expressing MMP-9 in the resection specimens. The only factor strongly associated with disease free survival was immunohistochemical status of tumour cells for MMP-9 in the resection specimens. Percentage of necrosis after chemotherapy failed marginally to reach statistical significance. On Cox regression analysis only MMP-9 remained significant for overall and disease free survival. Discussion: Once new blood vessels penetrate a microscopic primary tumour or a distant metastasis, the lesions acquire the potential to grow into larger and potentially life threatening tumours. MMP-9 is a factor associated with matrix remodeling during angiogenesis and is also associated with leaky vessels because of its ability to degrade basement membranes. These two properties are very important for tumour growth and development of haematogenous metastases and we believe may explain our findings

Our study examines a group of patients less than fifty years of age who underwent Total Elbow Arthroplasty with the Souter Strathclyde Elbow Replacement and compares their survivorship with a dataset of older group of patients. 309 patients were who underwent standard long stemmed Souter Implants as a primary procedure for rheumatoid arthritis over the last 16 years were included in this study. Patients were divided into two groups according to the their age at the time of surgery. In the first group of older patients greater than or equal to 50 years of age (Mean Age =64.4 years) there were 263 patients with a mean follow up of 7.3 years. The second group consisted of patients less than 50 years of age (Mean Age 42.04 years) who had a longer mean follow up period of 9.3 years. The survivorship of the implants for three different failure events was compared for both groups. The radiographs were evaluated using the Kaplan-Meir survival analyses, to produce survival curves for revision, revision due to aseptic loosening of the humeral component and finally gross loosening of the humeral implant (Hidex> 1). For each terminal event there were two curves and the age group analyses were all non-significant when log rank tested. The rates of loosening/revision were comparable in all curves. We set out to determine the role of age as predictive factor for loosening. Our conclusions were that Total Elbow Arthroplasty is suitable for younger patients with rheumatoid elbow. Using survivorship data there does not appear to be any difference in loosening when compared to patients of an older age group. As previously published the position of the humeral component within the humerus is crucial for long-term survivorship. Thus age alone should not be the sole discretionary factor for withholding the benefits of elbow Arthroplasty in younger patients

Introduction: By compromising bone structure, peri-prosthetic osteolysis may increase the risk of fracture and/or aseptic loosening of components leading to revision surgery. Our purpose was to develop a reproducible rabbit model of periprosthetic osteolysis and observe the effects of implant type and fixation on the latency to onset and size of the osteolytic lesions. Methods: Thirty-seven New Zealand White rabbits (71 knees) underwent knee arthrotomy and placement of cylindrical intramedullary stainless steel or polymethylmethacrylate (PMMA) implants. Each knee contained both a metallic and PMMA implant in either the femur or tibia that communicated with a common synovial space. A suspension of polyethylene particles (size < 4.5 um and concentration of 1-5 x 106 particles/ul) was injected into each knee at two-week intervals for ten weeks to induce osteolysis. Serial radiographs were taken at 4, 8, 14, 18, and 22 weeks postoperatively to document the progression of osteolysis. Statistical analysis was performed utilizing a two-tailed, unpaired t-test and a Mantel-Cox test with the level of significance set a p < 0.05. Results: Radiographic analysis revealed that 96.9% of the stainless steel implants had evidence of osteolysis by 22 weeks compared to 22.9% of the PMMA implants (p< 0.001). The earliest onset of lesions in the metal implant group occurred at four weeks compared to 14 weeks in the PMMA group. We also found the area and volume of the osteolytic lesions to be significantly larger in the metal implants when compared to the implants composed of PMMA (p < 0.01). Conclusions: Onset of osteolysis around metal implants occurred in a significantly shorter period of time and more frequently when compared to implants composed of PMMA. Also, the area and volume of the osteolytic lesions around the metal implants was found to be significantly larger than those of the PMMA. We concluded that relative material effects on osteoclast induced bone resorption and differences in ease of transport of particulate debris along metallic compared to PMMA surfaces may account for observed differences in frequency and severity of osteolytic lesions