Systemically administered zoledronic acid activates locally implanted synthetic hydroxyapatite particles enhancing peri-implant bone formation: A regenerative medicine approach to improve fracture fixation.

Fracture fixation in an ageing population is challenging and fixation failure increases mortality and societal costs. We report a novel fracture fixation treatment by applying a hydroxyapatite (HA) based biomaterial at the bone-implant interface and biologically activating the biomaterial by systemic administration of a bisphosphonate (zoledronic acid, ZA). We first used an animal model of implant integration and applied a calcium sulphate (CaS)/HA biomaterial around a metallic screw in the tibia of osteoporotic rats. Using systemic ZA administration at 2-weeks post-surgery, we demonstrated that the implant surrounded by HA particles showed significantly higher peri­implant bone formation compared to the unaugmented implants at 6-weeks. We then evaluated the optimal timing (day 1, 3, 7 and 14) of ZA administration to achieve a robust effect on peri­implant bone formation. Using fluorescent ZA, we demonstrated that the uptake of ZA in the CaS/HA material was the highest at 3- and 7-days post-implantation and the uptake kinetics had a profound effect on the eventual peri­implant bone formation. We furthered our concept in a feasibility study on trochanteric fracture patients randomized to either CaS/HA augmentation or no augmentation followed by systemic ZA treatment. Radiographically, the CaS/HA group showed signs of increased peri­implant bone formation compared with the controls. Finally, apart from HA, we demonstrated that the concept of biologically activating a ceramic material by ZA could also be applied to ß-tricalcium phosphate. This novel approach for fracture treatment that enhances immediate and long-term fracture fixation in osteoporotic bone could potentially reduce reoperations, morbidity and mortality. STATEMENT OF SIGNIFICANCE: • Fracture fixation in an ageing population is challenging. Biomaterial-based augmentation of fracture fixation devices has been attempted but lack of satisfactory biological response limits their widespread use. • We report the biological activation of locally implanted microparticulate hydroxyapatite (HA) particles placed around an implant by systemic administration of the bisphosphonate zoledronic acid (ZA). The biological activation of HA by ZA enhances peri­implant bone formation. •Timing of ZA administration after HA implantation is critical for optimal ZA uptake and consequently determines the extent of peri­implant bone formation. • We translate the developed concept from small animal models of implant integration to a proof-of-concept clinical study on osteoporotic trochanteric fracture patients. • ZA based biological activation can also be applied to other calcium phosphate biomaterials.

Arthroscopic Electromechanical Assessment of Human Articular Cartilage Injury Correlates with ICRS Scores.

PURPOSE: This study aimed to conduct arthroscopic evaluation of cartilage electromechanical properties and establish their correlation with International Cartilage Repair Society (ICRS) grading scores. METHODS: In 18 patients, quantitative parameter (QP) measurements were taken on the weight-bearing surface of the medial femoral condyle. Adjacently, the same site was graded using ICRS scores (0-4). Electromechanical QPs for ICRS grades 0 to 3 were obtained during arthroscopy, while complete grade 4 injuries were assessed using femur cartilage-bone blocks from knee arthroplasty. The QP values for ICRS grades 0 to 2 were compared with grades 3 and 4 using Welch t test. The corresponding QP values were assigned to ICRS grades 0 to 4 and compared using Welch ANOVA (analysis of variance). Pearson's coefficient evaluated QP-ICRS grade relationship. RESULTS: Healthy grade 0 cartilage displayed a mean QP value of 10.5 (±2.8 SD, n = 4). The ICRS grade 1 and grade 2 injuries were associated with QP values of 12 (±0.7, n = 2) and 13.25 (±1.77, n = 2), respectively. The grade 3 defects had QP values of 20.43 (±4.84, n = 4), whereas complete grade 4 defects showed electromechanical values of 30.17 (±2.19, n = 6). Significant differences in QP values were observed between ICRS grades 0 to 2 (mean QP 11.56 ± 2.3, n = 8) and grades 3 and 4 (26.27 ± 6, n = 10; P < 0.0001). Pearson's correlation coefficient of 0.9 indicated a strong association between higher ICRS cartilage injury grades and elevated QP values (P < 0.0001). CONCLUSION: Arthroscopic electromechanical QP assessment robustly correlates with ICRS scores. The QP values for ICRS grades 0 to 2 are significantly lower, compared with grades 3 and 4.

Arthroscopic treatment of intra-articular osteoid osteoma in the bicipital groove. A case report.

INTRODUCTION AND IMPORTANCE: Rare presence of intra-articular osteoid osteoma may be difficult to diagnose due to the lack of typical radiographic features and clinical appearance similar to other articular pathologies. Additionally traditional treatment choices for osteoid osteoma may not suit the given environment of the shoulder joint area. CASE PRESENTATION: We presented a 50-year-old male with a prolonged history of anterior shoulder pain and shoulder stiffness after physical activity. Intra-articular joint pathology was suspected after initial clinical and radiographic assessment. Magnetic resonance imaging revealed an osteoid osteoma in the humeral bicipital groove. CLINICAL DISCUSSION: The surgical goal is to resect the benign bony tumour. Though the established treatment by open surgery or radiological minimally invasive techniques may not be optimal since pathologies in the shoulder joint cannot be addressed without the risk of damage to articular structures and increased complications. In this case to avoid joint incision site morbidity and address adjacent pathology arthroscopic removal of the tumour with refixation of the biceps longus tendon was carried out. At follow up of 12 months post-surgery physical activity did not provoke stiffness and resting pain has subsided. CONCLUSION: Arthroscopic intra-articular osteoma resection in shoulder joint was optimal to address adjacent osteoma induced pathology, achieve great visualization, reduce incision site complication rates and achieve good results. Additional synovectomy during arthroscopic treatment can be performed, due to concomitant synovitis causing joint stiffness in most reported intra-articular OO cases.

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.

Can the inferior vena cava collapsibility index be useful in predicting hypotension during spinal anaesthesia in a spontaneously breathing patient? A mini fluid challenge.

The study was performed at the Department of Orthopaedics and Traumatology of the Kauno Klinikos Hospital of Lithuanian University of Health Sciences. BACKGROUND: Intravascular fluids are empirically administered to prevent hypotension induced by spinal anaesthesia. Ultrasound measurements of the inferior vena cava (IVC) and the IVC collapsibility index (IVC-CI) is a non-invasive method to evaluate the intravascular volume status. The aim of the study was to identify the prognostic value of the IVC collapsibility index in spontaneously breathing patients to predict severe intraoperative hypotension. MATERIALS AND METHODS: Sixty patients undergoing elective knee arthroplasty under spinal anaesthesia were included in the prospective study. The diameters of IVCex, IVCin, and IVC-CI were measured before and 15 min after spinal anaesthesia when administration of 500 ml of normal saline using infusion pump was finished. The haemodynamic parameters (heart rate, systolic, diastolic, and mean blood pressures, breathing rate) were collected. RESULTS: Severe arterial hypotension was noticed in 18.3% of the patients. No statistically significant differences were detected between changes in IVCex, IVCin, and IVC-CI comparing hypotensive and non-hypotensive patients at the baseline and after the interventions (p > 0.005). According to receiver operating characteristic (ROC) analysis, IVC-CI is not effective in the prediction of severe hypotension during spinal anaesthesia in spontaneously breathing patients: the area under the ROC curve for IVC-CI was <0.7, p > 0.05. CONCLUSIONS: IVC-CI is not an effective predictor of severe hypotension after induction of spinal anaesthesia followed by normal saline administration in spontaneously breathing patients undergoing elective knee arthroplasty. More trials, including different patient subgroups, will be needed.

Clinical outcome after treatment of single and multiple cartilage defects by autologous matrix-induced chondrogenesis.

PURPOSE: Characterized cartilage lesions have a distinct impact on postoperative clinical outcome, which is still being evaluated. The purpose of this study was to assess the postoperative clinical outcome of autologous matrix-induced chondrogenesis (AMIC) for characterized cartilage lesions. METHODS: Fifteen patients with articular cartilage (AC) defects of the knee were included in the study. AC defects were characterized intraoperatively by International Cartilage Repair Society score. Grade III-IV AC lesions were treated with AMIC; grade I-II lesions were left untreated. Patients were divided into subgroups and clinically evaluated by subjective autologous matrix-induced chondrogenesis (IKDC) and Tegner scores at median follow-up of 4.5 years. RESULTS: Twenty-eight AC defects were diagnosed (1.9/patient). Multiple subgroup had larger diagnosed (7 ± 2.3 cm2, p = 0.022) and untreated (3.1 ± 2.3 cm2, p = 0.012) lesion areas than the single subgroup. Partly treated subgroup had larger untreated defect areas (3.6±2.3 cm2, p = 0.025) than the Treated subgroup. Average subjective IKDC values of total group and individual subgroups improved significantly at follow-up. More patients restored their previous activity levels ( p = 0.026) and had higher incremental subjective IKDC scores ( p = 0.014) in the single subgroup than the multiple subgroup. Diagnosed defect size negatively correlated to subjective IKDC incremental ( r = -0.624, p = 0.023) and postoperative scores ( r = -0.545, p = 0.054) in total group. CONCLUSIONS: AMIC can have a clinically relevant outcome for patients with single or multiple knee AC lesions; however, clinical outcome is superior in patients with a single defect per knee. Patients with single defects returned to previous physical activity levels significantly faster than patients with multiple defects. Diagnosed AC defect areas negatively correlate to clinical improvement at follow-up.

The Patello-Femoral Joint Degeneration and the Shape of the Patella in the Population Needing an Arthroscopic Procedure.

Background: the main goal of the study was to investigate the prevalence of the articular cartilage defects (ACD) in the patellofemoral (PF) region of the knee joint based on the anatomical shapes of patella and its impact on the level of physical activity in the population needing arthroscopic procedures for all types of pathologies in the knee. Methods: The articular cartilage status of the PF region was obtained from 1098 arthroscopic procedures of the knee joint. The ACD were correlated to Wiberg's shape of the patella and classified according to the degree, size and depth of the ACD in the PF region using the ICRS (International Cartilage Repair Society) system: group I consisting of patients with Wiberg type I shape (W1), group II-patients with Wiberg type II shape (W2) and group III-patients with Wiberg type III shape (W3). The Tegner physical activity scale was used to evaluate the physical activity of the patients. Results: The mean of ACD size (PF region) in the W3 group was 3.10 ± 0.99 cm², which was a statistically significantly larger area in comparison with the W1 (1.90 ± 0.63 cm²; p < 0.0000) and W2 (1.95 ± 0.71 cm²; p < 0.0000). The patients from the W3 group (mean 3.10 ± 0.99) were less physically active (<4 Tegner) compared to the W2 group (mean of 4.48 ± 0.88; p = 0.004) and W1 group (mean of 4.55 ± 0.72; p = 0.002). Conclusions: The patients with the Wiberg type III patella shape had a higher incidence and larger size of ACD in the PF of the knee compared to the groups of Wiberg type I and II. Wiberg III patients with a lower level of physical activity had a larger size of ACD in the PF joint.

Measurements of Inferior Vena Cava Diameter for Prediction of Hypotension and Bradycardia during Spinal Anesthesia in Spontaneously Breathing Patients during Elective Knee Joint Replacement Surgery.

Background and objective: Hypotension and bradycardia are the most common hemodynamic disorders and side effects of spinal anesthesia (SA) on the cardiovascular system. SA-induced sympathetic denervation causes peripheral vasodilatation and redistribution of central blood volume that may lead to decreased venous return to the heart. The aim of the study was to evaluate the changes of inferior vena cava collapsibility index (IVC-CI) during SA in spontaneously breathing patients during elective knee joint replacement surgery to prognose manifestation of intraoperative hypotension and bradycardia. Materials and methods: 60 patients (American Society of Anesthesiologists (ASA) physical status I or II, no clinically significant cardiovascular pathology) of both sexes undergoing elective knee joint replacement surgery under SA were included in the prospective study. Inspiratory and expiratory inferior vena cava (IVCin, IVCex) diameters were measured using an ultrasound device in supine position before and immediately after SA, then 15 min, 30 min, and 45 min after SA was performed. The heart rate, along with systolic, diastolic, and mean arterial blood pressures were collected. The parameters were measured at the baseline and at the next four time points. Results: There were no significant changes in IVCin, IVCex, and IVC-CI compared to baseline and other time point measurements in hypotensive versus nonhypotensive and bradycardic versus nonbradycardic patients (p > 0.05). Changes in IVC diameter do not prognose hypotension and/or bradycardia during SA: the area under the curve (AUC) of the receiver operating characteristic (ROC) curve for IVC-CI at all measuring points was <0.7, p > 0.05. Conclusions: Reduction in IVC diameters and increase in IVC-CI do not predict hypotension and bradycardia during SA in spontaneously breathing patients undergoing elective knee joint replacement surgery.

Calcium Sulphate/Hydroxyapatite Carrier for Bone Formation in the Femoral Neck of Osteoporotic Rats.

This study investigated bone regeneration in the femoral neck canal of osteoporotic rats using a novel animal model. A calcium sulphate (CS)/hydroxyapatite (HA) carrier was used to deliver a bisphosphonate, zoledronic acid (ZA), locally, with or without added recombinant human bone morphogenic protein-2 (rhBMP-2). Twenty-eight-week-old ovariectomized Sprague-Dawley rats were used. A 1 mm diameter and 8 mm long defect was created in the femoral neck by drilling from the lateral cortex in the axis of the femoral neck, leaving the surrounding cortex intact. Three treatment groups and one control group were used: (1) CS/HA alone, (2) CS/HA + ZA (10 µg) (3) CS/HA + ZA (10 µg) + rhBMP-2 (4 µg), and (4) empty defect (control). The bone formation was assessed at 4 weeks post surgery using in vivo micro computed tomography (micro-CT). At 8 weeks post surgery, the animals were sacrificed, and both defect and contralateral femurs were subjected to micro-CT, mechanical testing, and histology. Micro-CT results showed that the combination of CS/HA with ZA or ZA + rhBMP-2 increased the bone formation in the defect when compared to the other groups and to the contralateral hips. Evidence of new dense bone formation in CS/HA + ZA and CS/HA + ZA + rhBMP-2 groups was seen histologically. Mechanical testing results showed no differences in the load to fracture between the treatments in either of the treated or contralateral legs. The CS/HA biomaterial can be used as a carrier for ZA and rhBMP-2 to regenerate bone in the femoral neck canal of osteoporotic rats.

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.

Influence of Graft Diameter on Functional Outcomes After Anterior Cruciate Ligament Reconstruction: A Prospective Study with a 1-Year Follow-Up.

BACKGROUND The aim of this study was to determine whether graft size is associated with recurrent instability and insufficient functional outcomes after ACL reconstruction. MATERIAL AND METHODS We analyzed 214 consecutive patients with a completed follow-up of 12 months: 55 (25.7%) women and 159 (74.3%) men. Patients were divided into 3 groups according to the diameter of the middle of the hamstring graft. Follow-up examinations were performed pre-surgery and 3, 6, and 12-months postoperatively, and laxity assessments were performed using GNRB®. Differential laxity measured at 134N (Δ134=heathy vs. operated side). A "residual laxity" of the ACLR was defined as Δ134N>3 mm. RESULTS The results of the General Linear Model (Repeated Measures) showed that there was a significant main effect of time factor (F=379.759, p<0.001, η²p=0.681) on differential laxity. We found statistically significant differences (p<0.001) in assessments of differential laxity pre-surgery and at 3, 6, and 12 months postoperatively (time factor). Tegner activity score at 12 months after reconstruction significantly differed when comparing patients with "residual laxity" (4.23±0.83) and others (4.85±1.17) (p=0.038). The study revealed a positive correlation between Tegner activity score at 12 months after surgery and pre-injury Tegner activity score (r=0.728, p<0.001) and negative correlation between age (r=-0.43, p<0.001) or BMI (r=-0.33, p<0.001). CONCLUSIONS Our study revealed that graft diameter is not associated with recurrent instability and does not affect laximetry results. The multiple regression model we developed made it possible to predict the Tegner activity score at 12 months after reconstruction based on pre-injury Tegner activity score, age (years), and BMI (kg/m²) of the patient.

Comparison of Return to Pre-Injury Sport After 10 mm Size Bone-Patellar Tendon-Bone (BPTB) versus 8 mm Hamstring Anterior Cruciate Ligament Reconstruction: A Retrospective Study with a Two-Year Follow-Up.

BACKGROUND The aim of this study was to evaluate the reconstruction of a torn anterior cruciate ligament (ACL) with 10 mm diameter BPTB (bone-patellar tendon-bone) autograft versus 8 mm HT (hamstring tendon) autografts, to compare the ability to restore pre-injury sports activities and reduce revision risk after these procedures. MATERIAL AND METHODS A prospective clinical review was performed to compare results of patients who underwent primary anatomical ACLR with 10 mm BPTB autografts with patients who underwent 8 mm diameter HT autografts, between January 2011 and January 2014. RESULTS There were 183 patients evaluated: the 8 mm HT group showed statistically significant higher knee laxity values compared to the 10 mm BPTB group (p=0.042), and significant difference were detected in subjective International Knee Documentation Committee (IKDC) evaluation scores; the average subjective IKDC evaluations after two-year follow-up in the HT group was 88.45±2.8 versus 89.24±2.5 in BPTB group (p=0.047). In the evaluation of the IKDC objective protocol, results were excellent and good in 83 patients (94.3%) after BPTB and in 78 patients (82%) after HT ACLR (p<0.05). The average score on the Tegner activity scale in the HT group decreased from 6.5 at pre-injury to 5.8 at two-year follow-up (p<0.001) and from 6.7 at pre-injury to 6.5 at two-year follow-up in the BPTB group (p=0.4). The ability to restore pre-injury sports activities was higher in the BPTB group (6.5) versus the HT group (5.8) (p<0.001). Revision was required for two patients (2.2%) in the BPTB group compared with 14 patients (14.7%) in the HT group (p<0.05). CONCLUSIONS Smaller HT graft size was a predictor of higher knee laxity and greater revision risk at two-year post primary ACL reconstruction. Larger diameter BPTB ACL grafts had a better ability to restore knee stability and greater ability to restore pre-injury sports activities.

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.

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.