Impact of video recordings review with structured debriefings on trauma team performance: a prospective observational cohort study.

PURPOSE: To determine the impact of structured debriefings (SD) with audio/video review of trauma patients' resuscitation events on trauma team (TT) technical and non-technical skills. METHODS: Single-center prospective observational cohort study. The study included all emergency department patients aged 18 years or older who received resuscitation from the TT. Virtual meeting was held with the TT using SD to review one trauma patient resuscitation video. Technical skills improvement was based on adherence to the ATLS protocol and non-technical skills based on T-NOTECHS scale. RESULTS: There was statistically significant improvement in adherence to the ATLS protocol: 73% [55-82%] vs 91% [82-100%] (p < 0.001); and improvement in T-NOTECHS scale: 12 [10-14] vs 16 [14-19] points (p < 0.001). CONCLUSION: In this study, we found that structured debriefings with review of patients' resuscitation video recordings can have a significant positive impact on trauma team performance in the emergency department in both technical and non-technical skills.

Interrater agreement between student and teacher assessments of endotracheal intubation skills in a self-directed simulation learning environment.

BACKGROUND: Practical skill assessment is an important part of the learning process to confirm competencies in acquired medical knowledge. OBJECTIVE: This study aimed to compare the assessments of endotracheal intubation skills using the HybridLab® methodology between students and teacher in terms of interobserver reliability. METHODS: Reliability analysis was performed with observational data (data are reported according to STROBE guidelines). The study was conducted in two countries, the Lithuanian University of Health Science (LUHS) and Pennsylvania State University (PSU) in the US, between 1 January and 30 June 2020. A total of 92 students (60 from LUHS and 32 from PSU) were trained in endotracheal intubation using an algorithm-driven hybrid learning method. At the end of the training session, the participants had to complete the evaluation scenario, which was assessed by one of the students and evaluated remotely by a single teacher. The student assessment of the endotracheal intubation procedure was compared with the teacher's assessment using correlation and estimation of the intraclass correlation coefficient. RESULTS: Overall, the medians of the student and teacher assessments were both 100% (0%). Spearman's correlation coefficient between the student and teacher assessments was 0.879 (p = 0.001). The intraclass correlation coefficient used for interobserver variations between the students and teacher was 0.883 (95% confidence interval from 0.824 to 0.923). CONCLUSIONS: The algorithm-driven hybrid learning method allows students to reliably assess endotracheal intubation skills to a level comparable with that of the teacher's evaluation. This learning method has the potential to be a cost-effective and efficient way to provide high-quality education while also saving human resources.

A novel algorithm-driven hybrid simulation learning method to improve acquisition of endotracheal intubation skills: a randomized controlled study.

BACKGROUND: Simulation-based training is a clinical skill learning method that can replicate real-life situations in an interactive manner. In our study, we compared a novel hybrid learning method with conventional simulation learning in the teaching of endotracheal intubation. METHODS: One hundred medical students and residents were randomly divided into two groups and were taught endotracheal intubation. The first group of subjects (control group) studied in the conventional way via lectures and classic simulation-based training sessions. The second group (experimental group) used the hybrid learning method where the teaching process consisted of distance learning and small group peer-to-peer simulation training sessions with remote supervision by the instructors. After the teaching process, endotracheal intubation (ETI) procedures were performed on real patients under the supervision of an anesthesiologist in an operating theater. Each step of the procedure was evaluated by a standardized assessment form (checklist) for both groups. RESULTS: Thirty-four subjects constituted the control group and 43 were in the experimental group. The hybrid group (88%) showed significantly better ETI performance in the operating theater compared with the control group (52%). Further, all hybrid group subjects (100%) followed the correct sequence of actions, while in the control group only 32% followed proper sequencing. CONCLUSIONS: We conclude that our novel algorithm-driven hybrid simulation learning method improves acquisition of endotracheal intubation with a high degree of acceptability and satisfaction by the learners' as compared with classic simulation-based training.

Different microbial and resistance patterns in primary total knee arthroplasty infections - a report on 283 patients from Lithuania and Sweden.

BACKGROUND: The microbiology and the susceptibility patterns of infected total knee arthroplasties (TKAs) vary depending on demographic, local antimicrobial stewardship, and surgical factors. We wanted to compare the recent microbial profile and antimicrobial resistance pattern in revisions due to infections after primary TKAs in Sweden and Lithuania. Our hypothesis was that there is a difference in bacteriology and resistance pattern based on patient related, societal and local hospital factors as almost similar praxis have been applied for TKA surgery, short term systemic prophylaxis and routine use of local gentamicin containing bone cement. METHODS: Primary TKAs revised for the first time due to verified or suspected infection were collected nationwide in Sweden during 2018, and in Lithuania between 2011 and 2020 from a single major TKA revision centre in Kaunas. We identified 202 TKAs in Sweden from the Swedish Knee Arthroplasty Register and 84 from Kaunas revised due to infection. We collected available culture reports and evaluated the type of microorganisms with antimicrobial resistance pattern at revision. RESULTS: The majority of the infected cases in Sweden were early-type prosthetic joint infection (PJI) (44%), whereas late-type PJI (52%) were more common in the Kaunas cases. Gram-positive bacteria prevailed in both Sweden (55%) and Lithuania (80%). Staphylococcus aureus was the most frequent organism identified in both countries (33% in Sweden and 34% in Lithuania). More polymicrobial infections were observed in Sweden than in Lithuania (16 and 6% respectively). Methicillin resistance in Staphylococcus aureus and coagulase-negative staphylococci were higher in Lithuania (4/28 and 19/29) than in Sweden (1/42 and 9/41). CONCLUSIONS: The type of infections, microbial profile, and drug resistance pattern differed between Sweden and Lithuania. Societal and local hospitals factors with emerging resistance in Lithuania are the most plausible explanation for the difference. Lack of complete data on a national level in Lithuania underlines the importance of adding microbiology of PJIs in implant registers for national aggregation and allow cross country comparisons.

Bipolar hemiarthroplasty versus total hip arthroplasty in femoral neck fracture patients: results from Lithuanian Arthroplasty Register.

INTRODUCTION: Elderly patients with displaced femoral neck fractures (FNF) are usually operated with arthroplasty but with various combinations of implants and approaches. Thus, the optimal treatment is still controversial. We aimed to compare the results between the cemented bipolar hemiarthroplasty (HA) and total hip arthroplasty (THA) patients operated for FNF regarding revision rate at 1 year postoperatively. METHODS: The data were derived from the Lithuanian Arthroplasty Register. We included patients operated with cemented bipolar HA and compared them to the most frequently used cemented THA with 28-mm head during 2011-2016. For survival analysis, we used both revision for all reasons and for dislocations as an endpoint. Cox proportional hazards models were used to analyse the influence of covariates (age groups, gender, surgical approaches and arthroplasty groups). RESULTS: There were 1177 bipolar HA and 514 THA included in our study. 26 (2.2%) revisions had occurred among the bipolar HAs as compared to 25 (4.9%) among the THAs 1 year after surgery. The main reason for revision was dislocation. The unadjusted cumulative revision rate for any reason at 1 year after surgery was 2.4% for the bipolar HA group and 5.1% for the THA group (p = 0.0054). Cox regression analysis showed that the use of bipolar HA, anterolateral approach and younger age groups had lower risk of revision for all reasons. CONCLUSION: Bipolar HA and anterolateral approach had a significantly lower overall 1-year risk of revision in femoral neck fracture patients as compared to THA with 28-mm femoral heads.

Inadequate evaluation and management of suspected -infections after TKA surgery in Lithuania: a retrospective study of 2,769 patients with 2-year follow-up.

Background and purpose - The evidence-based algorithms for treatment of periprosthetic joint infection (PJI) recommend surgical intervention in combination with the use of systemic antibiotics. However, still it is not unusual to treat total knee arthroplasty (TKA) patients with suspected infection using only antibiotics. We investigated treatment pathways for TKA patients with suspected infection in Lithuania. Patients and methods - Of the 4,069 TKA patients (4,269 knees) registered in the Lithuanian Arthroplasty Register (2013-2015) 2,769 patients (2,825 knees) were interviewed 2 years after the surgery. The patients were asked if they had been subject to antibiotic treatment after the TKA surgery and/or if any additional surgical interventions on the operated knee had been performed. The number of patients treated with antibiotics due to problems in the operated knee was identified and cumulative revision rates (CRR) were calculated. Results - 180 (7%) patients of the total 2,769 reported that they had been prescribed antibiotics after the primary TKA; 132 of these patients (70%) said they had received antibiotics due to problems with the operated knee. The 2-year CRR after TKA in patients not treated with antibiotics was 0.7% (95% CI 0.4-1), as compared with 24% (95% CI 17-32) in those who had used antibiotics due to the problems in the operated knee for more than 1 week. Interpretation - In Lithuania there seems to be a lack of adherence to evidence-based treatment guidelines when infection is suspected after primary TKA.

Outcomes and mortality after hip fractures treated in Kazakhstan.

INTRODUCTION: Patients with hip fractures are usually treated operatively in Western Europe. However, in Mid-Asia different indications are used to decide whether this patient is suitable for operative treatment and those are related to specific traditions and rules in hospital. Thus, traditions and surgeon/patient fears seem to affect treatment choices in hip fractures and subsequent outcomes. The aim of our study was to investigate patients with hip fractures and compare outcome at 1-year follow-up in the operated and nonoperated patient groups. METHODS: All patients over 50 years old who sustained a hip fracture, between January 2014 and December 2014, were included. Patients were assessed preoperatively and at 1-year follow-up, using questionnaires from National Swedish Hip Fracture Register and quality of life (Euroqol EQ-5D). RESULTS: Out of 398 included patients, 299 were operated on and 99 were not. 344 patients remained for our analysis before the end of 1-year follow-up. 51 patients (65%) deceased in the nonoperated group as compared to 55 (21%) in the operated group, p<0.001. Out of 27 patients in the nonoperated group hip function was evaluated at 1-year follow-up, 11 (41%) were walking independently or using 1 stick, as compared to 192 (91%) in the operated group. CONCLUSIONS: We conclude that nonoperative treatment of hip fracture patients is associated with higher mortality and worse functional outcome as compared to those who were treated operatively. We therefore advocate operative treatment of the hip fracture in the vast majority of cases.

Comparison of dual mobility cup and other surgical construts used for three hundred and sixty two first time hip revisions due to recurrent dislocations: five year results from Lithuanian arthroplasty register.

PURPOSE: Recently, there has been increasing interest in the use of dual mobility systems in the treatment of hip instability. The aim of this study was to investigate the re-revision rate of dual mobility cup compared to different surgical concepts when used for first-time hip revisions due to recurrent dislocations. METHODS: The data were derived from the Lithuanian Arthroplasty Register. For survival analysis, we used both re-revision for all reasons and for dislocations as an end-point. Cox proportional hazards models were used to analyze the influence of various covariates (age, gender, and implant concept). RESULTS: A total of 1388 revisions were recorded from 2011 to 2015, of which 362 were performed due to recurrent dislocation. Of the revisions, 247 were performed using dual mobility cups, while 115 were performed using a variety of other surgical constructs including constrained acetabular cups, conventional cups, femoral head exchanges, stem exchanges or anti-luxation rings. There were 27 re-revisions of which 15 were for additional dislocations. There were only 2% re-revisions due to dislocation with dual mobility vs 9% when using other surgical constructs. Cox regression adjusting for age and gender showed that in the short-term, dual mobility cup had a lower risk of revision due to dislocation as well as for all reasons compared to the other surgical constructs. CONCLUSION: In revision of total hip arthroplasties for dislocation, significantly lower short-term re-revision rate was observed for patients revised with dual mobility cup.

Outcomes and mortality after hip fractures treated in Kazakhstan.

INTRODUCTION: Patients with hip fractures are usually treated operatively in Western Europe. However, in Mid-Asia different indications are used to decide whether this patient is suitable for operative treatment and those are related to specific traditions and rules in hospital. Thus, traditions and surgeon/patient fears seem to affect treatment choices in hip fractures and subsequent outcomes. The aim of our study was to investigate patients with hip fractures and compare outcome at 1-year follow-up in the operated and nonoperated patient groups. METHODS: All patients over 50 years old who sustained a hip fracture, between January 2014 and December 2014, were included. Patients were assessed preoperatively and at 1-year follow-up, using questionnaires from National Swedish Hip Fracture Register and quality of life (Euroqol EQ-5D). RESULTS: Out of 398 included patients, 299 were operated on and 99 were not. 344 patients remained for our analysis before the end of 1-year follow-up. 51 patients (65%) deceased in the nonoperated group as compared to 55 (21%) in the operated group, p<0.001. Out of 27 patients in the nonoperated group hip function was evaluated at 1-year follow-up, 11 (41%) were walking independently or using 1 stick, as compared to 192 (91%) in the operated group. CONCLUSIONS: We conclude that nonoperative treatment of hip fracture patients is associated with higher mortality and worse functional outcome as compared to those who were treated operatively. We therefore advocate operative treatment of the hip fracture in the vast majority of cases.

Short-term outcome after total hip arthroplasty using dual-mobility cup: report from Lithuanian Arthroplasty Register.

PURPOSE: The purpose of the study was to investigate how the use of dual-mobility cups (DMCs) affected the risk of revision due to dislocation as well as overall risk of revision compared with a conventional total hip arthroplasty (THA) system in the short term. METHODS: A total of 12,657 primary THAs were registered from the start of 2011 to the end of 2014. 620 THAs were with DMCs. For comparison, we included all registered THAs with Exeter cup and a cemented Exeter stem combined with 28-mm femoral head. Patients were followed up with respect to revision and/or death until 1 January 2016. For survival analysis, we used revision as an endpoint. Cox proportional hazards models were used to analyse the influence of various covariates (age, gender, surgical approach, THA model and pre-operative diagnosis). RESULTS: Of the 620 dual-mobility THAs and 2170 Exeter THAs, 100 had been revised. The overall unadjusted cumulative revision rate (CRR) for any reason of revision at five years after surgery was 3.9% in the dual-mobility group and 5.2% in the Exeter group. Cox regression analysis, adjusting for age, gender, THA type, surgical approach and pre-operative diagnosis, showed that the risk of revision was less in patients operated with DMCs and in patients having their operation for osteoarthritis. CONCLUSION: The DM implant had a lower short-term complication rate than a conventional well defined THA. Low dislocation rate suggests that it is a good choice for high risk patients.

Measuring long radiographs affects the positioning of femoral components in total knee arthroplasty: a randomized controlled trial.

INTRODUCTION: The aim of this study was to investigate if preoperative measurements of the femoral valgus angle (FVA) affected the mechanical alignment, individual component positions and clinical outcome in total knee arthroplasty (TKA). METHODS: 120 patients were randomized into two groups. In one group (control), a fixed FVA for the intramedullary femoral guide was set at 7°, whereas in the other group (measured) FVA was measured preoperatively on long hip-knee-ankle radiographs, and the angle for the distal femoral cut was set accordingly. Preoperatively and 1 year after TKA, range of motion (ROM) and Knee Society Score (KSS) were assessed. Postoperatively, the coronal alignments of the components and the mechanical alignment were measured comparing the rate of outliers which deviated more than 3° from the neutral mechanical axis. RESULTS: 104 patients remained for the radiological analysis (52 in each group). There were no significant differences either in the mean preoperative or postoperative mechanical alignment, or femoral or tibial component alignment; also, there were no differences in the number of postoperative mechanical axis or tibial component alignment outliers. However, the number of femoral component alignment outliers was significantly higher in the control group. 97 patients were available for clinical outcome analysis. Preoperatively, the groups did not differ significantly with respect to KSS or ROM. The postoperative ROM and KSS functional subscale scores were similar between the groups. However, there was slightly but significantly better postoperative KSS objective subscale score in the measured group. CONCLUSIONS: Preoperative FVA measurement and following femoral distal cut adjustments did not affect overall leg alignment postoperatively, while positioning of femoral component was improved together with minor improvements in objective KSS subscale scores.

Excellent long-term results of the Müller acetabular reinforcement ring in primary total hip arthroplasty: A prospective study on radiology and survival of 321 hips with a mean follow-up of 11 years.

BACKGROUND AND PURPOSE: The original Müller acetabular reinforcement ring (ARR) shows favorable medium-term results for acetabular reconstruction in total hip arthroplasty, where it is used when the acetabular bone stock is deficient. However, there are no data regarding long-term survival of the device. We therefore investigated long-term survival and analyzed radiological modes of failure. PATIENTS AND METHODS: Between 1984 and 2002, 321 consecutive primary arthroplasties using an ARR were performed in 291 patients. The mean follow-up time was 11 (0-25) years, and 24 hips were lost to follow-up. For survival analysis, we investigated 321 hips and the end of the follow-up was the date of revision, date of death, or the last patient contact date with implant still in situ. Radiological assessment was performed for 160 hips with a minimum of 10 years of follow-up and with radiographs of sufficient quality. It included evaluation of osteolysis, migration, and loosening. RESULTS: 12 ARR THAs were revised: 1 isolated ARR revision for aseptic loosening, 4 revisions of the ARR and the stem for aseptic loosening, 6 for infection, and 1 for recurrent dislocation. The cumulative revision rate for all components, for any reason, at 20 years was 15% (95% CI: 10-22), while for the ARR only it was 7% (95% CI: 4-12) for any reason and 3.4% (95% CI: 1-9) for aseptic loosening. 21 (13%) of 160 ARR THAs examined had radiological changes: 7 had osteolysis but were not loose, and 14 were radiologically loose but were not painful and not revised. INTERPRETATION: Our data suggest that the long-term survival of the ARR is excellent.

Moderate varus/valgus malalignment after total knee arthroplasty has little effect on knee function or muscle strength.

BACKGROUND AND PURPOSE: Postoperative muscle strength and component alignment are important factors affecting functional results after total knee arthroplasty (TKA). We are not aware of any studies that have investigated the relationship between them. We therefore investigated whether coronal malalignment of the mechanical axis and/or of individual implant components would affect knee muscle strength and function 1 year after TKA surgery. PATIENTS AND METHODS: We included 120 consecutive osteoarthritis (OA) patients admitted for TKA. Preoperative active range of motion (ROM) of the knee, patient age, sex, and BMI were recorded and the Knee Society score (KSS) and knee joint extensor/flexor muscle strength were assessed. At 1-year follow-up, the mechanical and coronal component alignment was measured from a postoperative long standing radiograph, and ROM, KSS, and muscle strength measurements were taken in 91 patients. Functional outcome and muscle strength measurements were compared between normally aligned and malaligned TKA groups. RESULTS: 29 of 91 TKAs were malaligned, i.e. they deviated more than 3° from the neutral mechanical axis. 18 femoral components and 15 tibial components were malaligned. Before surgery, the malaligned and normally aligned groups were similar regarding sex distribution, BMI, ROM, KSS, and muscle strength. At the 1-year follow-up, the differences between the groups regarding knee joint function and muscle strength were small, not statistically significant, and barely clinically relevant. INTERPRETATION: Moderate varus/valgus malalignment of the mechanical axis or of individual components has no relevant clinical effect on function or muscle strength 1 year after TKA surgery.

The analysis of posterior soft tissue repair durability after total hip arthroplasty in primary osteoarthritis patients.

BACKGROUND AND PURPOSE: The posterior soft tissue repair is 1 of the preventing factors for dislocation after total hip arthroplasty (THA).The aim of our study was to analyse THA patients with posterior soft tissue repair in terms of suture durability, time of suture failure and correlate the changes in leg length and offset postoperatively to suture durability. METHODS: A total of 37 consecutive THA patients operated for osteoarthritis were included in the study. The posterior repair included reattaching the piriformis, conjoined tendons and posterior capsule to the greater trochanter through 2, 2 mm drill holes with 2 grasping stitches. A metal indicator wire was stitched into the piriformis tendon at distance of 1 cm from the greater trochanter after the prosthesis had been implanted and the joint reduced. Anteroposterior radiographs were taken immediately after the patients returned from the operating theatre to the intensive care unit, the next day after mobilisation, and at the 5th day of stay and at 3 months postoperatively. RESULTS: Out of 37 THA hips, 6 (16%) had failed immediately after surgery, 25 (68%) at the 1st postoperative day after mobilisation, 2 (5%) at the 5th postoperative day, and 1 (3%) repairs had failed at 3 months after THA. In the remaining 3 hips no failure occurred. INTERPRETATION: We conclude that posterior soft tissue repair in THA often fails and suggest that new posterior soft tissue repair methods be developed.

Choice of approach, but not femoral head size, affects revision rate due to dislocations in THA after femoral neck fracture: results from the Lithuanian Arthroplasty Register.

PURPOSE: Hip dislocation after arthroplasty for femoral neck fractures (FNF) remains a serious complication. The aim of our study was to investigate FNF patients treated with THA, with a special focus of comparing the effect of surgical approach and femoral head size on the risk of revision for dislocation. METHODS: Data were derived from the Lithuanian Arthroplasty Register, and we calculated the cumulative revision rates after surgery. For survival analysis, we used revision due to dislocation as an end-point. Cox proportional hazards models were used to analyse the influence of various covariates (age, gender, femoral head size, surgical approach). RESULTS: A total of 8,813 primary THAs were registered from 1 January 2011 to 31 December 2013, of which 1,412 were due to FNF: 899 involved 28-mm femoral heads and the remaining 513 received 32-mm heads. The posterior approach was used in 1,156 cases and the anterolateral approach in 256.. At the end of the follow-up period, 74 hips had been revised for recurrent dislocation. Cox regression adjusting for age, gender and head size showed that the posterior approach had 2.3-times [95% confidence interval (CI): 1.0-5.0, p = 0.04] greater risk of revision for dislocation CONCLUSIONS: We conclude that in order to reduce the early dislocation rate in FNF patients treated with THA, it is more effective to use the anterolateral approach than it is to select a femoral head size of 32 mm instead of 28 mm.

First outcome results after total knee and hip replacement from the Lithuanian arthroplasty register.

BACKGROUND AND OBJECTIVE: In 2010, the Lithuanian Association of Arhtroplasty was established and on January 1, 2011, initiated a national study of all reoperations after total knee (TKR) and total hip replacement (THR) in Lithuania. The aim of the study was to investigate the revision rates after TKR and THR at two years follow-up. MATERIALS AND METHODS: Lithuanian patients undergoing primary TKR and THR from January 1, 2011, to December 31, 2012, were included in the study. The patient, surgery and prosthetic implantation data were collected via internet database. For reoperations we recorded the reason and type of revision, primary implantation date. We analyzed implant survival rates using any revision as an endpoint on included primary procedures, performed until September 1, 2013. RESULTS: The completeness of the register verified with state patients fund data reached 85% of all replacements. Out of 3823 primary TKR during the study period 25 revisions were performed with overall implant survival rate 99%. The main reason for knee revision was infections. During the inclusion period we registered 6072 primary THR and 149 revisions with overall implant survival rate 97%. Recurrent dislocation of prosthetic component was the main reason for hip revision. Significantly inferior survival results for femoral neck fracture patients were observed as compared with patients operated for osteoarthritis. Posterior approach as compared to others significantly affected inferior implant survival rates for femoral neck fracture patients. CONCLUSIONS: The overall survival after total knee and hip replacements revealed a high treatment quality of this surgery in Lithuania.

Size of cup affects the anterior capsular distance in total hip arthroplasty, as measured with ultrasound.

BACKGROUND: Previously was found that sonography is a reliable method to measure a capsular distance in total hip arthroplasty hips. The aim of our current study was to investigate the relation between the implanted size of the cup and the anterior capsular distance, as measured with ultrasound one year after THA. METHODS: 50 osteoarthritis (OA) patients operated on with total hip arthroplasty one year before were included in the study and the anterior capsular distance was measured sonographically. Patients were grouped with respect to cup size. The correlation between the implanted cup size and capsular distance was determined. RESULTS: The mean capsular distance in the whole group was 1.37 (SD 0.19) cm. The mean capsular distance in the group with small cups was 1.27 (SD 0.13) cm, in large cups it was 1.45 (SD 0.20) cm, p = 0.02. Spearman correlation analysis showed a statistically significant correlation between a greater capsular distance and the larger size of the cup (r = 0.5, p < 0.0001). CONCLUSION: The greater capsular distance in successful THA hips is affected by cup size. We propose that this should be considered when evaluating sonography of the anterior capsular distance after THA.

Dynamics of femoral bone remodelling in well fixed total hip arthroplasty. A 20-year follow-up of 20 hips.

The aim of our study was to investigate the dynamics of cortical thinning around well fixed cemented Muller straight stems without osteolysis at different time periods during long term follow-up. We investigated patients operated on for osteoarthritis with a cemented Muller straight stem, all with more than 15 years follow-up and no radiological signs of osteolysis. Cortical thinning in 20 THA hips (19 patients) followed for a mean of 20 (16 to 22) years was measured medially and laterally at six levels from the first postoperative, five, 10 years and the last follow-up x-rays. Sixty percent of observed cortical thinning occurred during the first five postoperative years, which was more evident proximally. We conclude that significantly greater cortical bone loss occurs around cemented Muller straight stems during the first five years, than is seen subsequently. We feel that this is a non-pathological process mainly related to the Muller straight stem.

Long-term femoral bone remodeling after cemented hip arthroplasty with the Müller straight stem in the operated and nonoperated femora.

We investigated the cortical bone changes in 35 patients with total hip arthroplasty operated on only for osteoarthritis with more than 10 years of follow-up and with nonrevised femoral components and without radiologic signs of loosening. The mean follow-up was 16 ± 5 years. The thicknesses of femoral cortices were measured medially and laterally at 6 levels from the first postoperative and the last follow-up x-rays. A comparison with 10 patients who had a nonoperated contralateral hip was performed. We found a significant decrease in cortical thicknesses in total hip arthroplasty. The cortical thinning was significant at all periprosthetic levels but less expressed distally. Prosthetic femora were associated with greater cortical thinning as compared with the contralateral nonoperated femora, exceeding that caused by natural aging.