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Background Because loosening of total knee arthroplasty (TKA) occurs due to poor osseous integration at component-bone interfaces, interface assessment may be helpful in diagnosing loosening at MRI. Purpose To determine interreader reproducibility for characterizing component interfaces and diagnosing loosening and to evaluate the diagnostic performance of MRI for diagnosing loosening after TKA compared with radiography. Materials and Methods Consecutive knees with TKA that underwent revision between July 2018 and June 2019 and were imaged at MRI and radiography were included in this retrospective study. Interface type (normal, fibrous membrane, fluid, or osteolysis), percent integration (33%, 33%-66%, or66%), and presence of bone marrow edema pattern were assessed. Loosening was diagnosed at MRI if no or almost no normal interface was present. Sensitivity and specificity were compared with radiographs by using surgical findings as reference. Gwet agreement coefficient evaluated interreader reproducibility between two readers and multivariable logistic regression assessed risk factors for loosening. Results Among 116 knees in 114 patients (mean age, 63 years ± 10 [SD]; 59 women), 61 of 116 knees (52.6%) had at least one loose component. Interreader reproducibility of MRI was substantial to excellent (Gwet agreement coefficient, 0.67-0.96). Loosening was associated with fluid interface (odds ratio [OR], 20.1; 95% CI: 5.7, 70.9) or osteolysis (OR, 3.1; 95% CI: 1.8, 5.3), absence of any normal interface (OR, 11.8; 95% CI: 6.3, 22.2), poor (33%) osseous integration (OR, 20.4; 95% CI: 9.7, 42.6), and bone marrow edema pattern (OR, 4.7; 95% CI: 2.8, 7.8). Sensitivity and specificity of MRI for loosening were 84% (27 of 32; 95% CI: 72, 97) and 85% (71 of 84; 95% CI: 77, 92) for the patellar, 31% (eight of 26; 95% CI: 13, 49) and 100% (90 of 90; 95% CI: 100, 100) for the femoral, and 81% (22 of 27; 95% CI: 66, 96) and 98% (87 of 89; 95% CI: 95, 100) for the tibial component, respectively. MRI had higher sensitivity (84% vs 31%

Background and purpose: Elective total hip replacement (THR) was halted in our institution during the COVID-19 surge in March 2020. Afterwards, elective THR volume increased with emphasis on fast-track protocols, early discharge, and post-discharge virtual care. We compare early outcomes during this “return-to-normal period” with those of a matched pre-pandemic cohort.Patients and methods: We identified 757 patients undergoing THR from June to August 2020, who were matched 1:1 with a control cohort from June to August 2019. Length of stay (LOS) for the study cohort was lower than the control cohort (31 vs. 45 hours; p < 0.001). The time to first postoperative physical therapy (PT) was shorter in the study cohort (370 vs. 425 minutes; p < 0.001). More patients were discharged home in the study cohort (99% vs. 94%; p < 0.001). Study patients utilized telehealth office and rehabilitation services 14 times more frequently (39% vs. 2.8%; p < 0.001). Outcomes included post-discharge 90-day unscheduled office visits, emergency room (ER) visits, complications, readmissions, and PROMs (HOOS JR, and VR-12 mental/physical). Mann–Whitney U and chi-square tests were used for group comparisons.Results: Rates of 90-day unscheduled outpatient visits (5.0% vs. 7.3%), ER visits (5.0% vs. 4.8%), hospital readmissions (4.0% vs. 2.8%), complications (0.04% vs. 0.03%), and 3-month PROMs were similar between cohorts. There was no 90-day mortality.Interpretation: A reduction in LOS and increased telehealth use for office and rehabilitation visits did not adversely influence 90-day clinical outcomes and PROMs. Our findings lend further support for the utilization of fast-track arthroplasty with augmentation of postoperative care delivery using telemedicine.

There is a paucity of data on blood loss and the risk of allogeneic blood transfusion after simultaneous bilateral total hip arthroplasty (SBTHA) with contemporary blood management including neuraxial anesthesia, routine tranexamic acid use, and a restrictive transfusion protocol. As such, we sought to determine the in-hospital outcomes of SBTHA, specifically analyzing blood loss and the rate and risk factors for transfusion.We identified 191 patients who underwent SBTHA at a single institution from 2016 to 2019. No drains were utilized and no patients donated blood preoperatively. Mean age was 59 years with 96 females (50.3%). The surgical approach was posterior in 138 (72.3%) and direct anterior in 53 (27.7%) patients. We analyzed blood loss, the rate of allogeneic blood transfusions, and in-hospital thromboembolic complications. We analyzed risk factors for transfusion with a logistic regression analysis.Twenty-two patients (11.5%) underwent allogeneic blood transfusion. All transfused patients were female. Univariate analysis revealed female gender as a transfusion risk factor since it had statistically significant higher proportion in the transfusion group than the nontransfusion group (100% vs 43.5%, respectively, P.001). We did not identify any other singular significant risk factors for transfusion in a multivariable regression analysis. However, females with a preoperative Hb12 had an elevated risk of transfusion at 37.5% (15/40 patients).With contemporary perioperative blood management protocols, there is a relatively low (11.5%) risk of a blood transfusion after SBTHA. Females with a lower preoperative Hb (12 g/dL) had the highest risk of transfusion at 37.5%.

Hip resurfacing (HR) requires a larger approach and soft tissue dissection and might therefore be associated with increased blood loss compared to total hip arthroplasty (THA). However, the effect of the adoption of tranexamic acid (TXA) in this setting is unknown. Therefore, the current study compares the blood loss and transfusion requirements between HR and posterior THA in patients receiving TXA.This retrospective cohort study included patients undergoing primary, unilateral THA or HR using a posterior approach between February 2016 and 2020 in which TXA was administered. THA and HR patients were propensity score matched using nearest neighbor greedy matching accounting for demographic, health and surgical variables. Postoperative hemoglobin (Hgb) levels and Hgb drop from preoperative to post-operative day (POD) 1 were compared using t-tests and associated risk factors were assessed using linear mixed modelling.After matching, each cohort consisted of 1395 patients. Cohorts were similar regarding age, sex, BMI, and Charlson Comorbidity Index. No significant differences were found for Hgb levels on POD 1 (12.3 g/dl; p = 0.90) or Hgb drop (2.3 g/dl; p = 0.87). Duration of surgery was significantly longer for HR patients (82 vs 77 min; p 0.01). Transfusion rate was 0.1% in both cohorts (p = 1.00). Hospital stay was significantly shorter for HR patients (1 vs 2 days; p 0.01).HR using a standard TXA regimen is not associated with greater perioperative blood loss than posterior THA and does not result in increased transfusion requirements. Both surgical procedures can be considered equally safe in terms of perioperative blood management when TXA is used.

Dislocation in Total hip arthroplasty (THA) is a common postoperative complication and reason for revision surgery. The direct anterior approach has become more popular over the last decade. The purpose of this study was to compare postoperative dislocation rates of the direct anterior and the posterior approach at a one-year follow-up. 797 consecutive hips operated through a posterior approach [698 patients (307 male, 391 female)] between 2009 and 2012, were compared to 690 selected THA [610 patients (423 female, 187 male)] operated since 2012. Anterior hip replacement surgery was primarily indicated for patients demanding increased flexibility after surgery (Yoga) or were considered a higher risk for dislocation. During a one-year follow-up there were eight dislocations out of 797 THA (1%) in the posterior group and none in the 690 THA (0%) in the anterior group (p-value of 0.008). Average time to dislocation was 7.5 weeks in the posterior group. Five of eight patients with dislocations needed revision surgery due to persistent instability. Even in a higher-risk patient population, the direct anterior approach showed a lower dislocation rate compared to the posterior approach in the first year after surgery.

Background The present article analyzes the association of the functional anterior cruciate ligament (ACL) status and the overall varus deformity and coronal tibiofemoral subluxation (CTFS) in varus OA of the knee. Methods One hundred consecutive knees with varus OA in 84 patients were prospectively included. Knees were divided into two groups, in accordance with the ACL status (functionally sufficient or insufficient). All included patients were potential candidates for unicompartmental knee arthroplasty with predominantly medial compartment OA. Knees with Kellgren/Lawrence ≥ grade 3 in the lateral compartment were excluded leaving 79 knees to be included in this study. Mechanical varus deformity and CTFS were evaluated on AP radiographs and valgus stress radiographs, and compared between the two groups. Results Knees with a functionally insufficient ACL had significantly more varus deformity on hip-to-ankle AP standing radiographs (P = .001) and on valgus stress radiographs (P = .017). CTFS on AP standing radiographs was significantly higher (P = .045) in knees with a functionally insufficient ACL. Seventy-three percent (8/11) of the ACL-insufficient knees had a varus deformity of ≥10° and 64% (7/11) of ACL-insufficient knees had CTFS ≥ 6mm. By contrast, only one patient (2%, 1/41) with an insufficient ACL had Conclusion Functional ACL insufficiency in osteoarthritic varus knees is associated with greater varus deformity and more advanced CTFS. Seventy-three percent of ACL-insufficient knees had a varus deformity of ≥10° and 64% of ACL-insufficient knees a CTFS of ≥ 6mm. In the work-up for medial unicompartmental knee arthroplasty, functional ACL insufficiency is likely in knees with varus deformity of ≥10° and CTFS of ≥ 6mm.

Introduction: In conjunction with impaction bone grafting (IBG), metal meshes have been proposed to minimise defects of the medial and superolateral walls in order to convert combined complex uncontained segmental defects into contained cavitary defects to facilitate IBG. Methods: The US National Library of Medicine (PubMed/MEDLINE), EMBASE, and the Cochrane Database of Systematic Reviews were queried for publications from January 1980 to March 2019 utilising keywords pertinent to total hip arthroplasty (THA), acetabular impaction bone grafting, clinical or functional outcomes, revision THA, or postoperative complications. Results: 7 articles were found to be suitable for inclusion in the present study. The mean modified Coleman methodology score for methodological deficiencies of the studies was 45.3 (range 38–59). Severe acetabular bone loss was present in 56% of cases having moderate bone loss in 18%, and mild in 26%. The all-cause reoperation rate was 7.4%, while the all-cause revision rate of the acetabular component was 6.2%. Conclusions: IBG with mesh is effective for selected patients with acetabular bone defects. Most patients with moderate bone loss as well as selected patients with large superolateral defects can be successfully treated with IBG combined with mesh. There is limited data to show that IBG with mesh might be associated with decreased survival rates in patients with severe lateral defects (Paprosky IIIA) combined with ischial or medial wall osteolysis who require combined medial and lateral meshes. In addition, patients with severe superomedial migration of the cup (Paprosky IIIB) should not be treated with IBG and mesh.

Purpose The proximal chevron osteotomy and the modified Lapidus arthrodesis are both procedures utilized for deformity correction in patients with severe symptomatic hallux valgus. The aim of the current study was to compare their biomechanical stability when using locking plate fixation. Methods Twelve matched pairs of human anatomical lower leg specimens underwent on one side a proximal chevron osteotomy with a medial locking plate and on the other side a modified Lapidus arthrodesis with a plantar locking plate utilizing an interfragmentary compression screw. All specimens underwent bone mineral density (BMD) assessment and were tested in a servohydraulic load frame which applied a load on the centre of the metatarsal head over 1000 loading cycles with subsequently ultimate load testing. Displacement of the proximal and distal bone segment, ultimate load, and bending stiffness were analyzed. Results Mean displacement of both procedures showed no statistically significant difference throughout all the loading cycles (0.213 ≤ p ≤ 0.834). The mean ultimate load of the proximal chevron osteotomy was 227.9 N (± 232.4) and of the modified Lapidus arthrodesis 162.9 N (± 74.6) (p = 0.754). The proximal chevron osteotomy (38.2 N/mm (± 24.9)) had a significantly higher bending stiffness compared to the modified Lapidus arthrodesis (17.3 N/mm (± 9.9)) (p = 0.009). There was no correlation between BMD and displacement in all loading cycles, ultimate load, and bending stiffness of either procedure (p > 0.05). Conclusion Although the bending stiffness of the chevron osteotomy was higher, there was no statistically significant difference between the surgical techniques in mean displacement and ultimate load. The BMD did not influence the overall stability of either reconstruction. Locking plate fixation increases the clinical value of the modified Lapidus arthrodesis by outweighing most of the biomechanical disadvantages in comparison to the proximal chevron osteotomy.

A radiographic overlap of the lateral femoral condyle and the lateral tibial spine (‘tibial spine sign’) might indicate lateral compartment cartilage damage and might be considered a contraindication for unicompartmental knee arthroplasty (UKA). Therefore, the following research questions were asked: (1) does the presence of a ‘tibial spine sign’ on radiographs correlate with cartilage lesions on the medial aspect of the lateral femoral condyle on corresponding MRIs?; (2) do cartilage lesions on the medial aspect of the lateral femoral condyle indicate cartilage damage in the central area of the distal lateral femur?; and 3) is the ‘tibial spine sign’ impacted by the degree of varus deformity, the amount of coronal tibiofemoral subluxation or the functional status of the ACL? One hundred consecutive knees with varus OA in 84 patients were prospectively included. The relationship of the lateral femoral condyle and the tibial spine was graded from 0 to 2 based on the degree of overlap on AP standing knee radiographs. On MRI, cartilage on the medial aspect of the lateral femoral condyle was assessed. Cartilage in the weight-bearing area of the distal lateral femur was analysed according to the OARSI system. The ‘tibial spine sign’ assessment correlated well with the degree of cartilage damage on the medial aspect of the lateral condyle (rs = 0.7, p

There has been a considerable increase in total joint arthroplasty (TJA) research using machine learning (ML). Therefore, the purposes of this study were to synthesize the applications and efficacies of ML reported in the TJA literature, and to assess the methodological quality of these studies.PubMed, OVID/MEDLINE, and Cochrane libraries were queried in January 2021 for articles regarding the use of ML in TJA. Study demographics, topic, primary and secondary outcomes, ML model development and testing, and model presentation and validation were recorded. The TRIPOD (Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis or Diagnosis) guidelines were used to assess the methodological quality.Fifty-five studies were identified: 31 investigated clinical outcomes and resource utilization; 11, activity and motion surveillance; 10, imaging detection; and 3, natural language processing. For studies reporting the area under the receiver operating characteristic curve (AUC), the median AUC (and range) was 0.80 (0.60 to 0.97) among 26 clinical outcome studies, 0.99 (0.83 to 1.00) among 6 imaging-based studies, and 0.88 (0.76 to 0.98) among 3 activity and motion surveillance studies. Twelve studies compared ML to logistic regression, with 9 (75%) reporting that ML was superior. The average number of TRIPOD guidelines met was 11.5 (range: 5 to 18), with 38 (69%) meeting greater than half of the criteria. Presentation and explanation of the full model for individual predictions and assessments of model calibration were poorly reported (30%).The performance of ML models was good to excellent when applied to a wide variety of clinically relevant outcomes in TJA. However, reporting of certain key methodological and model presentation criteria was inadequate. Despite the recent surge in TJA literature utilizing ML, the lack of consistent adherence to reporting guidelines needs to be addressed to bridge the gap between model development and clinical implementation.

To evaluate the transfusion rates for octogenarians and nonagenarians following total knee and hip arthroplasty (TKA, THA), we compared transfusion rates and associated risk factors among sexagenarians, septuagenarians, octogenarians, and nonagenarians.This retrospective cohort study included 13,603 sexagenarians, 9796 septuagenarians, 2706 octogenarians, and 158 nonagenarians that received a primary, unilateral THA or TKA between 2016 and 2020 at a high-volume institution. Using multivariable logistic regression analysis, the study analyzed risk factors for postoperative transfusions including use of tranexamic acid (TXA) and compared preoperative and postoperative hemoglobin (Hgb) levels and the drop in Hgb.Nonagenarians had significantly higher transfusion rates (THA 25.5%, TKA 26.7%) than octogenarians (THA 9.9%, TKA 9.2%), septuagenarians (THA 3.3%, TKA 4.5%), and sexagenarians (THA 1.9%, TKA 2.9%) (P.01). Significant risk factors for transfusion requirement following THA were American Society of Anesthesiologists level III (odds ratio [OR] 5.3, P.01) and American Society of Anesthesiologists level IV (OR 8.0, P = .01), nonuse of TXA (intravenous: OR 0.3, P.01; topical: OR 0.5, P.01), lower preoperative Hgb levels (OR 0.4, P.01), longer duration of surgery (OR 1.0, P.01), and hepatopathy (OR 3.1, P.01). Significant risk factors following TKA were nonuse of TXA (intravenous: OR 0.3, P.01; topical: OR 0.5, P.01; combined: OR 0.2, P.01), lower preoperative Hgb levels (OR 0.4, P.01), and longer surgery time (OR 1.0, P.01).The strongest independent risk factors for increased transfusion rates among octogenarians and nonagenarians were lack of TXA application and lower preoperative Hgb levels. Routine TXA application and preoperative patient optimization are recommended to reduce transfusion rates in patients aged 80+.

Background Proponents of the direct anterior approach (DAA) for total hip arthroplasty (THA) claim a faster recovery, whereas critics claim an increased risk of early femoral complications. This study analyzed intraoperative and postoperative complications requiring reoperation within one year after THA through the DAA and posterior approach (PA). Methods A total of 2348 elective, unilateral DAA THAs in patients with osteoarthritis performed between 2016 and 2019 were matched 1:1 for age (±5 years), gender, body mass index (±5), and femoral fixation with 2348 patients who underwent PA THA during the same period. Mixed-effects logistic regression was used. Odds ratios were reported for the occurrence of intraoperative femoral fracture, postoperative femoral fracture, infection, dislocation, and other etiologies requiring reoperation within one year. Results Intraoperative femoral fracture occurred in 12 DAA (0.5%) and 14 PA (0.6%) patients. Twenty-five patients (1.06%) in the DAA and 28 (1.19%) in the PA group underwent reoperation within the first year. Reoperations were due to periprosthetic fracture (40%), infection (28%), dislocation (23%), and other (9%). Regression analysis revealed no difference in intraoperative femoral fracture (odds ratio (OR): 0.86, 95% confidence interval (CI): 0.40-1.86, P = .69), postoperative femoral fracture (OR: 1.10, 95% CI: 0.47-2.60, P = .83), infection (OR: 1.50, 95% CI: 0.53-5.23, P = .44), or reoperation within one year for other reasons (OR: 1.50, 95% CI: 0.25-9.00, P = .65). DAA had fewer dislocations requiring reoperation (OR: 0.20, 95% CI: 0.04-0.91, P = .02). Conclusion This comparative study did not find differences in intraoperative or postoperative fracture or infection between DAA and PA. DAA was associated with a lower likelihood of reoperation for dislocation within one year of surgery.

Correct acetabular component positioning improves hip biomechanics, impingement free range of motion and may lead to a reduced risk of postoperative dislocation. The C-arm is a simple and cost-effective tool for THA in a supine position, however, evaluation of the images can be challenging due to parallax. The current study aimed to investigate whether a software app-based measurement technique can control acetabular component position and leg length in anterior THA. Ninety-three patients with end-stage osteoarthritis aged 65.2 ± 9.6 years (range 30–86 years) were included in this prospective study. All patients underwent direct anterior THA using a Hana orthopedic surgery table. C-arm imaging and an iPad software app were used to determine intraoperative acetabular anteversion, inclination and leg length discrepancy. The app provides a measuring tool that is applied to intraoperative c-arm images. The intraoperative measurements were compared to the measurements of standard postoperative AP-pelvis radiographs. Intraoperative software app-based anteversion measurements averaged 20.5° (range 16.0° to 24.0°) compared to 20.9° (range 14.7° to 25.6°) postoperatively. Mean intraoperative inclination was 40.5° (range 35° to 48°) compared to postoperative 40.7° (range 35° to 49°). Mean intraoperative leg length discrepancy was 0.9 mm (range – 4–5 mm) compared to postoperative 0.6 mm (range – 5–6 mm). A strong Pearson’s correlation was observed between the intraoperative and postoperative measurements for anteversion (r = .701; P

Advanced valgus osteoarthritis (OA) is one of the most challenging indications for total knee arthroplasty (TKA). There is no information in the literature about the optimal timing of surgery. The current study investigates the impact of the preoperative deformity and degree of arthritis on postoperative outcome after TKA.The study evaluated 133 knees in 107 patients with valgus OA that failed nonoperative treatment with a minimum 2-year follow-up. Mechanical alignment, Kellgren and Lawrence (K/L) score, and minimal joint space width (minJSW) were measured on AP- and hip-to-ankle radiographs. All knees had advanced OA (i.e., K/L grades 3 or 4 and less than 50% minJSW). Pre- and postoperative WOMAC, VR-12, UCLA, VAS, ROM were recorded.There was no difference in clinical outcome (WOMAC, UCLA, VR-12, VAS or ROM) between patients with different degrees of valgus deformities ( 5.0 deg., 5.0-9.9 deg., 10.0-14.9 deg., ≥ 15.0 deg.). There was also no correlation between K/L score or minimal joint space width and any of the outcome parameters.The degree of valgus deformity and the grade of osteoarthritis do not predict the outcome of TKA in patients with valgus OA. Since the risk of complication and the need for implant constraint increases with increasing deformity and instability of the knee, surgery appears to be justified in patients with advanced OA that failed nonoperative treatment, regardless of the degree of deformity.

Introduction The direct anterior approach (DAA) is suggested to accelerate postoperative recovery and decrease the dislocation risk after primary total hip arthroplasty (THA). However, exposure of the femur can be challenging. Insufficient exposure increases the risk for intraoperative femoral fracture. Materials and methods Of 435 consecutive anterior THA, the first 102 consecutive THA in 94 patients were treated with an external rotator tendon “release-on-demand” (RoD). The following 311 consecutive patients (333 THA) underwent routine release of the conjoint tendon (CTR) of its bony insertion on the greater trochanter only. Retrospective analysis recorded trochanteric fractures, intraoperative calcar fractures, postoperative periprosthetic fractures, stem subsidence, ossifications, and dislocations. Results Three (2.9%) fractures of the greater trochanter were recorded in the RoD group, but no (0.0%) fractures occurred in the CTR group (p = 0.002). There was no significant difference in the occurrence of intraoperative calcar fractures (0% (RoD) vs. 1.2% (CTR), p = 0.267), postoperative periprosthetic fractures (0% (RoD) vs. 0.3% (CTR), p = 0.560), stem subsidence (2.0% (RoD) vs. 1.2% (CTR), p = 0.565) or ossifications (2.9% (RoD) vs. 1.6% (CTR), p = 0.344) between these groups. There were no dislocations within a minimum 12 months follow-up period. Conclusion The routine release of the conjoined tendon (CTR group) decreases the shear forces on the tip of the greater trochanter during DAA THA and eliminates the risk of greater trochanter fractures. The routine release of the conjoined tendon did not increase the risk of postoperative dislocations.

AimsTo compare patients undergoing total knee arthroplasty (TKA) with ≤ 80° range of movement (ROM) operated with a 2 mm increase in the flexion gap with matched non-stiff patients with at least 100° of preoperative ROM and balanced flexion and extension gaps.MethodsIn a retrospective cohort study, 98 TKAs (91 patients) with a preoperative ROM of ≤ 80° were examined. Mean follow-up time was 53 months (24 to 112). All TKAs in stiff knees were performed with a 2 mm increased flexion gap. Data were compared to a matched control group of 98 TKAs (86 patients) with a mean follow-up of 43 months (24 to 89). Knees in the control group had a preoperative ROM of at least 100° and balanced flexion and extension gaps. In all stiff and non-stiff knees posterior stabilized (PS) TKAs with patellar resurfacing in combination with adequate soft tissue balancing were used.ResultsOverall mean ROM in stiff knees increased preoperatively from 67° (0° to 80°) to 114° postoperatively (65° to 135°) (p < 0.001). Mean knee flexion improved from 82° (0° to 110°) to 115° (65° to 135°) and mean flexion contracture decreased from 14° (0° to 50°) to 1° (0° to 10°) (p < 0.001). The mean Knee Society Score (KSS) improved from 34 (0 to 71) to 88 (38 to 100) (p < 0.001) and the KSS Functional Score from 43 (0 to 70) to 86 (0 to 100). Seven knees (7%) required manipulations under anaesthesia (MUA) and none of the knees had flexion instability. The mean overall ROM in the control group improved from 117° (100° to 140°) to 123° (100° to 130°) (p < 0.001). Mean knee flexion improved from 119° (100° to 140°) to 123° (100° to 130°) (p < 0.001) and mean flexion contracture decreased from 2° (0° to 15°) to 0° (0° to 5°) (p < 0.001). None of the knees in the control group had flexion instability or required MUA. The mean KSS Knee Score improved from 48 (0 to 80) to 94 (79 to 100) (p < 0.001) and the KSS Functional Score from 52 (5 to 100) to 95 (60 to 100) (p < 0.001). Mean improvement in ROM (p < 0.001) and KSS Knee Score (p = 0.017) were greater in knees with preoperative stiffness compared with the control group, but the KSS Functional Score improvement was comparable (p = 0.885).ConclusionTKA with a 2 mm increased flexion gap provided a significant improvement of ROM in knees with preoperative stiffness. While the improvement in ROM was greater, the absolute postoperative ROM was less than in matched non-stiff knees. PS TKA with patellar resurfacing and a 2 mm increased flexion gap, in combination with adequate soft tissue balancing, provides excellent ROM and knee function when stiffness of the knee had been present preoperatively. Cite this article: Bone Joint J 2020;102-B(4):426–433.

Different alignment types for a better outcome after TKA were described. However, it is not clear how kinematic alignment influences knee joint kinematic. The purpose of this study was to analyze whether adapted tibial cuts in constitutional varus knees affect knee joint kinematics regarding femoral roll-back, varus/valgus angle, and femorotibial rotation. Seven cadaveric knees with constitutional varus alignment were examined in the native state and after implantation of a cruciate retaining (CR)-TKA with 0°, 3° and 6° tibia cuts using an established knee joint simulator. The effects of varus alignment on femorotibial rollback and rotation was determined. In addition, the native knee joint and different tibial cuts in CR-TKA were compared with Student’s t test. Total knee replacement with a 3° and 6° varus tibia cut had the greatest varus deviation to the native knee (mean 1.6° ± 0.09°, respectively); while, knees with a 0° (mean 0.2° ± 0.01°) tibia cut were most similar to the constitutional varus knee joint. The femoral roll-back in the medial compartment was increased in the native knee (5.7–12.5 mm). A 6° varus cut had a restricted translation in the medial compartment (2–3.2 mm). In the lateral compartment, the extensive translation was observed with a 0° varus cut, followed by 3° and 6° and the native knee. All cuts showed significantly different mean values. Only the cuts at 3° and at 6° in the medial compartment and the cuts at 0° and at 3° in the lateral compartment did not differ significantly. In respect to tibiofemoral rotation, 0° and 3° varus cuts across all loads had the least difference to the native knee (3.4°), with a 0° varus cut showing a higher absolute internal rotation of the tibia than the native knee. Changes in knee kinematics of the tibiofemoral rotation showed significantly different mean values. The potentially improved outcome parameters in TKA with adapted tibia cuts in constitutional varus knees cannot be completely explained by the changes to knee kinematics. Mechanical alignment seems to result in more balanced load distribution and kinematics more closely resembling the native knee. From a kinematic point of view, it is not recommended to place the tibia in more than 3° of varus. Biomechanical study.

Introduction. Two-stage revision is the gold standard for the treatment of deep implant infection after knee or hip arthroplasty. Irrigation and debridement may be a treatment option for failed 2-stage revisions in cases where a reinfection occurs within 30 days or the symptoms exist not longer than 3 weeks and is appealing because of its low morbidity. We determined the incidence of recurrent infections following irrigation and debridement for failed two-stage revision hip and knee arthroplasty. Methods. We performed a single center retrospective review of periprosthetic hip and knee infections treated with a two-stage procedure from 2002 to 2010. All patients that subsequently underwent irrigation and debridement for a subsequent infection were selected for the current study. Results. 440 two-stage revisions were performed between 2002 and 2010. Fifty-one two-stage revisions failed (11.6%). Nineteen failed two-stage revisions were treated with irrigation and debridement; 12 (63.2%) patients remained free of infection at follow-up (mean follow-up: 39 months; range, 24-90 months), infection persisted in 6 patients (31.6%), and 1 patient died (5.3%). Conclusions. Success rates of irrigation and debridement for failed two-stage procedures are similar to the success rates of irrigation and debridement in primary implant infections. According to the current paper, irrigation and debridement are an acceptable treatment for acute reinfections after failed two-stage revision if performed within the first 30 postoperative days after failed two-stage procedure or if symptoms are present for less than 3 weeks in the presence of a susceptible organism.

Tranexamic acid (TXA) reduces bleeding and the need for transfusion after total knee arthroplasty. Most literature has focused on intravenous (IV) administration of TXA, with less data available on the efficacy of topically administered TXA. This multicenter randomized clinical trial specifically assessed the efficacy of topical TXA compared with IV TXA as measured by calculated blood loss, drain output, and transfusion rates. Complications, including venous thromboembolism (VTE), were reported.A total of 640 patients who underwent primary unilateral total knee arthroplasty for osteoarthritis at 2 large academic centers were randomized to receive 1 g of IV TXA prior to tourniquet inflation and 1 g at closure, or 3 g of TXA diluted in 45 mL of normal saline solution (total volume of 75 mL) and topically applied after cementation. Age, sex, body mass index, American Society of Anesthesiologists (ASA) score, and preoperative hemoglobin level were similar between the groups. Univariate, multiple linear regression, and multiple logistic regression analyses were performed.Patients who received topical TXA had significantly greater calculated blood loss compared with those who received IV TXA (mean of 324 compared with 271 mL; p = 0.005). Drain output was significantly higher in the topical TXA group compared with the IV TXA group (mean of 560 compared with 456 mL; p0.0001). The rate of transfusion was low in the topical and IV groups, with no significant difference on univariate analysis (1.6% compared with 0.6%, respectively; p = 0.45); however, on multiple logistic regression analysis, patients who received topical TXA were 2.2-fold more likely to receive a transfusion (p0.0001). The topical and IV TXA groups did not differ significantly with respect to the rate of thrombotic events (0.6% compared with 1.6%, respectively; p = 0.45).In this large, randomized clinical trial involving patients undergoing total knee arthroplasty, both IV and topical TXA were associated with a low rate of transfusion. While IV TXA was associated with less calculated blood loss, lower drain output, and fewer transfusions, the small differences between the groups may not be clinically important. Given the low prevalence of thrombotic complications, the relative safety of one formulation of TXA over the other cannot be definitely established.Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Although metal-on-metal (MoM) total hip arthroplasty (THA) and hip resurfacings (HR) have similar bearing surfaces and comparable wear rates, metal ion levels and risk of failure are higher for MoM–THA. The mechanism behind the increased metal ion levels in large head MoM–THA is not completely understood. The current study aims to identify predictive factors for increased metal ion levels in unilateral and bilateral large head MoM–THA. 99 Birmingham modular MoM–THA in 87 patients with metal ion levels at least 36 months after index procedure were analyzed. Mean follow-up time was 61.3 months (range 37–108) and the relationship of the following variables (gender, age, BMI, follow-up time, UCLA Activity Score, cup inclination, femoral head size, bilateral surgery) on metal ion levels were analyzed with multivariate regression models. Multivariate regression analysis revealed that bilateral MoM–THA surgery (p

The medial parapatellar arthrotomy (MPPA) is a commonly utilized surgical approach; however, the placement of the arthrotomy and its influence on intraoperative patellar tracking has not been evaluated. Six knees from three fresh frozen cadavers with transthoracic amputations were operated on. All underwent standard posterior stabilized total knee arthroplasty using a medial parapatellar approach placed at the border of the vastus medialis oblique (VMO)–quadriceps junction. Patellae were resurfaced in the standard fashion. All patellae tracked normally with the first arthrotomy placed at the junction of the VMO–quadriceps tendon using the “no touch” technique. Measurement of patellar lift-off from the implant surface of the medial aspect of the trochlea on the femoral component was made at 50°, 75°, and 90° of flexion and a merchant view radiograph taken to evaluate radiographic patellar tilt. To simulate a more lateral placement of the MPPA, a 5–6 mm slice of quadriceps tendon was then removed from the lateral aspect of the tendon from the patellar insertion to the most proximal portion of the arthrotomy. This simulated a 5–6 mm more lateral placement of the parapatellar arthrotomy. The same measurements and radiographs were taken as described previously. Two more times the same size slices was removed from the quadriceps tendon with subsequent measurements and radiographs obtained. The mean patellar lift-off with the first arthrotomy was 0 ± 0 mm for 50°, 75°, and 90° of flexion. The mean lift with the second arthrotomy was 2 ± 2, 3 ± 3, and 4 ± 3 mm respectively. The third arthrotomy had a mean patellar lift-off of 3 ± 2, 4 ± 3, and 8 ± 2 mm respectively, while the fourth arthrotomy had a mean lift-off of 6 ± 2, 8 ± 2, and 9 ± 4 mm. There was a significant correlation between percentage of quadriceps cut at 1 cm above the superior pole of the patella and patellar lift-off at 50° (R 2 = 0.70; p

The histopathological synovitis score evaluates the immunological and inflammatory changes of synovitis in a graduated manner generally customary for diagnostic histopathological scores. The score results from semiquantitative evaluation of the width of the synovial surface cell layer, the cell density of the stroma and the density of the inflammatory infiltration into 4 semiquantitative levels (normal 0, mild 1, moderate 2, severe 3). The addition of these values results in a final score of 0-9 out of 9. On the basis of this summation the condition is divided into low-grade synovitis and high-grade synovitis: A synovitis score of 1 to≤4 is called low-grade synovitis (arthrosis-associated/OA synovitis, posttraumatic synovitis, meniscopathy-associated synovitis and synovitis with haemochromatosis). A synovitis score of≥5 to 9 is called high-grade synovitis (rheumatoid arthritis, psoriatic arthritis, Lyme arthritis, postinfection/reactive arthritis and peripheral arthritis with Bechterew's disease). By means of the synovitis score it is therefore possible to distinguish between degenerative/posttraumatic diseases (low-grade synovitis) and inflammatory rheumatic diseases (high-grade synovitis) with a sensitivity of 61.7% and a specificity of 96.1%. The diagnostic accuracy according to ROC analysis (AUC: 0.8-0.9) is good. Since the first publication (2002) and an associated subsequent publication (2006), the synovitis score has nationally and internationally been accepted for histopathological assessment of the synovitis. In a PubMed data analysis (status: 14.02.2017), the following citation rates according to Cited by PubMed Central articles resulted for the two synovitis score publications: For DOI: 10.1078/0344-0338-5710261 there were 29 Cited by PubMed Central articles and for the second extended publication DOI:10.1111/j.1365-2559.2006.02508 there were 44 Cited by PubMed Central articles. Therefore a total of 73 PubMed citations are observed over a period of 15 years, which demonstrates an international acceptance of the score. This synovitis score provides for the first time a diagnostic, standardised and reproducible histopathological evaluation method enabling a contribution to the differential diagnosis of chronic inflammatory general joint diseases. This is particularly the case by incorporation into the joint pathology algorithm. To specify the synovitis score an immunohistochemical determination of various inflammation-relevant CD antigens is proposed to enable a risk stratification of high-grade synovitis (e.g.: progression risk and sensitivity for biologicals).

Progression of arthritis in the lateral compartment is one of the main failure modes of unicompartmental knee arthroplasty (UKA). The decision regarding whether to perform a medial UKA sometimes is made based on whether lateral-compartment osteophytes are visible on plain radiographs obtained before surgery, but it is not clear whether the presence of lateral-compartment osteophytes signifies that the cartilage in the lateral compartment is arthritic. (1) Is the presence of lateral compartment osteophytes associated with biomechanical properties of lateral-compartment cartilage, and (2) are osteophytes in the lateral compartment associated with particular histologic features of cartilage in the lateral compartment? Between May 2010 and January 2012, we performed 201 TKAs for varus osteoarthritis confirmed on standardized AP hip-to-ankle standing radiographs. All patients with a varus deformity were considered for this prospective study. During the enrollment period, 100 patients (101 knees) were not enrolled for this study because of declined consent or because they were unable to perform all required preoperative radiographic examinations. That left 84 patients (100 knees), of whom an additional 23 patients (27%) were excluded because either radiographic or biomechanical data were missing. For final analysis, 61 patients (71 knees) were available. There were 29 males (48%) and 32 females (52%) with a mean age of 65 years (range, 49–89 years). Their mean BMI was 26 kg/m2 (range, 17–47 kg/m2). Lateral-compartment osteophytes were graded by two observers on AP standing knee radiographs based on a template of the Osteoarthritis Research Society International (OARSI) radiographic atlas. During surgery, osteochondral plugs were harvested from the lateral tibial plateau and the distal lateral femur for biomechanical and histologic assessments. The intrinsic material coefficients aggregate modulus (Ha) and dynamic modulus (DM) were determined by applying a compressive load of 20 g for 1 hour. The histologic analysis was performed according to the qualitative osteoarthritis cartilage histopathology assessment system. The Mann-Whitney U test was performed to compare the distribution of variables. Power analysis was performed for the Mann-Whitney U test using an alpha of 0.05, a power of 80%, and a sample size of 71 resulting in a detectable effect size of 0.6. Owing to the limited sample size, only medium or large effects in changes of biomechanical properties can be excluded with adequate power. Ha and DM were not different with the numbers available when comparing knees with osteophyte Grades 0, 1, and 2 on the lateral tibia. For Grade 3 tibial osteophytes (n = 3), the lateral tibia cartilage showed low Ha (0.39 MPa; SD, 0.17 MPa) and low DM (2.85 MPa; SD, 2.12 MPa). On the lateral femur, no differences of Ha and DM were observed with the numbers available between Grades 0 to 3 osteophytes. No differences with the numbers available in the OARSI histologic grades on the lateral tibia plateau and the distal lateral femur were observed between the different osteophyte grades. Lateral-compartment osteophytes are not associated with biomechanically weaker cartilage or with more-advanced histologic signs of degeneration of lateral-compartment cartilage in knees with varus arthritis. Given the small sample size of 71, the study was underpowered to detect small-to-modest decreases in biomechanical properties. Future studies with larger sample sizes are needed to confirm the current findings. Factors other than the presence or absence of lateral-compartment osteophytes should be considered when evaluating patients with medial-compartment arthritis for medial UKA. Future studies are required to define the limitations of plain radiographs to rule out cartilage degeneration in the lateral compartment of varus knees.

Topical tranexamic acid (TXA) was introduced to replace the previous targeted preoperative autologous blood donation (PABD) program. This study aims to analyze the efficacy of topical TXA compared with targeted PABD in anemic patients undergoing primary total hip arthroplasty (THA).Two thousand two hundred fifty-one patients underwent primary THA between 2009 and 2013 using targeted autologous blood donation for 280 anemic patients (12%; Hb12.5 g/dL). One thousand nine hundred seventy-one nonanemic patients (88%; ≥12.5 Hb/dL) received no blood management intervention. Starting in 2014, 505 consecutive patients were operated using 3 grams of topical TXA and abandoning PABD. Ninety-one patients (18%) were anemic and 414 (82%) nonanemic.The utilization of topical TXA in anemic patients resulted in higher hemoglobin levels on the first postoperative day (P = .014), but not on the second postoperative day (P = .198) compared with PABD. There was no difference in allogeneic transfusion rates between both groups: 12% vs 13% (P = .848). In the nonanemic group, TXA significantly increased hemoglobin levels on the first postoperative day (P = .001) as well as on the second postoperative day (P.001), and resulted in a reduction in allogeneic transfusion rates from 8% to 1%.The present study suggests that topical TXA is equivalent to PABD in anemic patients and reduces transfusion rates and increases Hb-levels in nonanemic patients.

The stem/keel location varies between anatomic and symmetric revision tibial baseplates. The current study investigates the impact of an anatomic versus symmetric stem location on the need for offset couplers in revision total knee arthroplasty. Hip to ankle standing radiographs and lateral radiographs of 75 patients were analyzed using digital templating software. The offset in the anterior–posterior as well as medial–lateral plane between the center of the tibial diaphysis and the stem of the tibial baseplate were determined for an anatomic and symmetric tibial baseplate, respectively. Measurements were repeated for 4 resection levels: tip of fibular head (0), 10 mm (1), 15 mm (2) and 20 mm (3) below the tip of the fibula head. Anatomic tibial baseplates require less offset for resection levels up to the tip of the fibula: total offset 2.28 versus 5.44 mm (p

Background We present the early institutional experience with the use of impaction bone grafting, mesh augmentation, and cement fixation of an all-polyethylene cup for the treatment of Paprosky 3B acetabular defects during revision total hip arthroplasty. Methods Between 2005 and 2014, 21 patients (9 men, 12 women) with Paprosky 3B acetabular defects who underwent revision total hip arthroplasty using this technique were reviewed clinically and radiographically. Average age and body mass index were 72.4 (range, 48-91) years and 24.5 (range, 18.9-31) kg/m 2 , respectively. All patients underwent revision for aseptic loosening. Surgical technique included the use of a peripheral mesh to contain the defect, followed by impaction of morselized fresh-frozen bone graft and cement fixation of a polyethylene cup. Results Complications occurred in 6 patients (29%) including limp (2), sciatic nerve palsy that resolved (1), limb length discrepancy (1), and greater trochanteric fracture (1). After an average follow-up of 47 months (range, 13-128 months), the average Hospital for Special Surgery hip score was 35.5 (range, 20-40). Radiographic assessment revealed cephalad cup migration of 2.29 mm (range, 0-20 mm) and medial migration of 1.57 mm (range, 0-6 mm). One patient has radiographic loosening and no symptoms 120 months postoperatively. No patient returned to the operating room for a related reason or is scheduled to undergo acetabular re-revision surgery. Conclusion Impaction bone grafting is a reliable technique for the treatment of Paprosky 3B acetabular defects. It restores bone stock like no other available for addressing these defects. Longer follow-up is required to assess potential deterioration of fixation.

Background The present study investigates the novel Synovasure periprosthetic joint infection (PJI) lateral flow test device for detection of alpha-defensin and attempts to determine its diagnostic accuracy for the intraoperative diagnosis of PJI and compares it to frozen section. Methods Forty consecutive patients, who underwent revision surgery, between September 2014 and September 2015 were included. The patients underwent 29 revision total knee arthroplasties and 11 revision total hip arthroplasties. Twelve patients had a confirmed PJI based on Musculoskeletal Infection Society criteria, and 28 patients were considered aseptic. Results The overall accuracy to detect PJI using the lateral flow assay was 85% (95% CI 70%-93%). The device has a positive predictive value of 80% (95% CI 44%-96%) and a negative predictive value of 87% (95% CI 68%-96%) and showed a sensitivity of 67% (95% CI 35%-89%) and specificity of 93% (95% CI 75%-99%). Frozen section had a lower sensitivity (58% [95% CI 29%-84%]) but a higher specificity (96% [95% CI 80%-100%]). Receiver operator curve analysis demonstrates an area under the curve of the Synovasure PJI Lateral Flow Test Kit and frozen section of 0.80 and 0.77, respectively. Conclusion The present study suggests that the intraoperative lateral flow test is at least equivalent to intraoperative frozen section and is a useful tool to confirm the absence of PJI. Although the clinical results are promising, they are not as good as previous studies using alpha-defensin levels measured in a laboratory.

Approximately 10% of all patients that require a total knee arthroplasty present with valgus osteoarthritis (OA) of the knee. Valgus OA goes along with posterolateral bone loss and lateral soft tissue tightness. The role of malalignment on the development of OA is not fully understood. The current study investigates whether the femoral offset (FO), femoral mechanical–anatomical (FMA) angle, anatomical lateral distal femur angle (aLDFA), mechanical lateral distal femur angle (mLDFA), medial proximal femur angle (MPFA), medial proximal tibia angle (MPTA) or lateral distal tibia angle (LDTA) differ in patients with valgus OA of the knee. FO, FMA angle, aLDFA, mLDFA, MPFA, MPTA and LDTA were assessed and compared between 100 consecutive knees with minimal valgus OA (50 male, 50 female) and 100 consecutive knees with minimal varus OA (50 male, 50 female). FO was significantly higher in males with valgus OA (p = 0.002) and females with varus OA (p = 0.01). The observed values for the FMA angle were significantly higher in males with valgus OA (p = 0.002) and females with varus OA (p = 0.041). The aLDFA and mLDFA were significantly smaller in all patients with valgus OA (p

Background To treat the increasing number of patients with osteoarthritis (OA) of the knee, high-volume institutions rely on central referral services as first contact point. Depending on the grading of arthritis, patients will be referred to a nonoperative or operative care provider. The present study reports on a simple 5-step questionnaire to identify patients with OA (Kellgren/Lawrence [KL] grade ≥2) of the knee to improve efficiency of referrals. Methods We included 998 patients who contacted the physician referral service at the author’s institution complaining of knee pain and divided them into 2 groups. The study group included patients with an appointment and consisted of 646 patients (345 women [53.4%] and 301 men [46.6%]). X-rays of the knee were graded according to the KL classification system. The control group of patients who did not make an appointment consisted of 352 patients (187 women [53.1%] and 165 men [46.9%]). These patients were contacted to evaluate whether they had been diagnosed with OA of the knee since their initial call, to assure that the study group was not exposed to a selection bias. Results Logistic regression revealed 5 questions as significant predictors for OA of the knee (KL grade ≥2). When combining both groups, an 86.9% sensitivity, a 73.3% specificity, and an 84.3% overall accuracy were reached, when patients answered 3 or more questions positively. Conclusion The present study revealed a simple 5-step questionnaire to identify patients with OA of the knee. Implementation of the questionnaire has the potential to improve the accuracy of referral processes and streamline organization before the first appointment.

Background Elevated serum levels of chromium and cobalt ions in metal-on-metal (MoM) bearing surfaces is a well-known phenomenon in THA. However, few studies have addressed this issue in complex primary and revision knee arthroplasty using a MoM hinged mechanism, and no study, to our knowledge, has investigated knees with MoM hinges in patients without megaprostheses (tumor prostheses). Questions/purposes We analyzed a series of patients who received MoM hinged revision knee prostheses and asked: (1) What are the serum metal ion levels at short-term followup? (2) Is there any correlation between metal ion levels and the Knee Society Score (KSS) at this followup? Methods Between 2013 and 2017, we performed 198 revision knee arthroplasties, of which 32 (17.7%) were performed with a latest-generation MoM hinge knee design. In addition, three complex primary TKAs utilizing the same design were included in this study. The device features a metal-on-polyethylene bearing with a MoM hinge. During that period, our general indications for using a hinge were single-stage and two-stage revision surgeries, revisions with large bone defects, and primary TKA with > 20° mechanical malalignment or collateral ligament insufficiency. Of the 35 patients who received this device, 23 patients (65% of the overall group who received this implant; 11 males, 12 females) were available for followup at a median of 28 months (range, 13-61 months), and the remaining 12 (35%) patients were lost to followup. Our rationale for reporting before the more typical 2-year minimum was the finding of elevated serum ion levels with unclear clinical significance. Median age at the time of surgery was 68 years (range, 52-84 years). None of the patients included in the study had other implants with MoM bearings. Serum ion levels of chromium (III) and cobalt were assessed using mass spectrometry. Ion levels > 5 ppb were considered elevated. Clinical outcome was assessed using the original KSS. Results Median chromium serum level was 6.3 ppb (range, 0.6-31.9 ppb) and median cobalt serum level was 10.5 (range, 1.0-47.5 ppb). Of the 23 patients, 16 had elevated serum ion levels. There was a moderate correlation between KSS and both chromium (p = 0.029, r = 0.445) and cobalt (p = 0.012, r = 0.502) levels. Conclusions Elevated metal ion levels and radiolucent lines are common after surgery with this MoM hinge design at short-term followup, and we believe this finding is of great concern. Although no patient has yet been revised, these patients will be closely monitored. We recommend that serum ion analysis become a routine part of followup after any hinge TKA in an attempt to better understand the potential consequences of this phenomenon. Level of evidence Level IV, therapeutic study.

Progression of osteoarthritis over time is poorly understood. The aim of the current study was to establish a timeline of "cartilage survival rate" per subregion of the knee in relation to mechanical alignment of the lower extremity. The study hypothesized that there are differences in progression of osteoarthritis between varus, valgus and physiologic lower extremity alignment.Based on hip-knee-ankle standing radiographs at baseline, 234 knees had physiologic (180° ± 3°, mean 179.7°), 158 knees had varus ( 177°; mean 174.5°) and 66 knees valgus ( 183°; mean 185.2°) alignment (consecutive knees of the OAI "Index Knee" group, n = 458; mean age 61.7; 264 females). The Osteoarthritis Initiative (OAI; a multi-center, longitudinal, prospective observational study of knee osteoarthritis [30] using MRIs) defines progressive OA as a mean decrease of cartilage thickness of 136 µm/year and a mean decrease of cartilage volume by 5% over 1 year (DESS sequences, MRI). A Kaplan-Meier curve was generated for osteoarthritis progression based on OAI criteria.Osteoarthritis progression based on volume decrease of 5% in varus knees occurred after 30.8 months (medial femoral condyle), after 37 months (medial tibia), after 42.9 months (lateral femoral condyle) and 43.4 months (lateral tibia), respectively. In a valgus alignment progression was detectable after 31.5 months (lateral tibia), after 36.2 months (lateral femoral condyle), after 40.4 months (medial femoral condyle) and 43.8 months (medial tibia), respectively. The physiological alignment shows a progression after 37.8 months (medial femoral condyle), after 41.6 months (lateral tibia), after 41.7 months (medial tibia) and after 43 months (lateral femoral condyle), respectively.Based on data from the OAI, the rate and location (subregion) of osteoarthritis progression of the knee is strongly associated with lower extremity mechanical alignment.Level I (prognostic study).

Radiostereometric analysis (RSA) is the most accurate technique to measure implant migration. However, it requires special equipment, technical expertise and analysis software and has not gained wide acceptance. The current paper analyzes a novel method to measure implant migration utilizing widely available computer tomography (CT). Three uncemented total hip replacements were performed in three human cadavers and six tantalum beads were inserted into the femoral bone similar to RSA. Six different 28 mm heads (−3, 0, 2.5, 5.0, 7.5 and 10 mm) were added to simulate five reproducible translations (maximum total point migration) of the center of the head. Implant migration was measured in a 3-D analysis software (Geomagic Studio 7). Repeat manual reconstructions of the center of the head were performed by two investigators to determine repeatability and accuracy. The accuracy of measurements between the centers of two head sizes was 0.11 mm with a CI 95 % of 0.22 mm. The intra-observer repeatability was 0.13 mm (CI 95 % 0.25 mm). The interrater-reliability was 0.943. CT based measurement of head displacement in a cadaver model were highly accurate and reproducible.

Metal-on-metal (MoM) bearings are known to release metal ions secondary to wear and corrosion. This may cause local reactions (adverse soft tissue reactions and osteolysis) and systemic effects. Little is known about the exact pattern and the differences between large head MoM total hip replacements (THA) and resurfacings (HR).(1) Is there a difference in metal ion concentrations between HR and MoM-THR using the same bearing design (Birmingham Hip Resurfacing System, SmithNephew, Inc. Memphis, TN, USA)? (2) Are metal ion levels changing over time in MoM-THA or HR? (3) Do acetabular inclination angle and femoral component size influence cobalt and chromium levels? Is there a correlation between clinical outcome and metal ion levels?A retrospective analysis was conducted in 77 well functioning unilateral Birmingham HR and 42 well functioning unilateral modular Birmingham MoM-THA (SmithNephew, Inc. Memphis, TN, USA) operated on between 2007 and 2012. Blood samples were taken at a minimum of 13 months and subsequent during annual follow-ups.(1) Cobalt levels were significantly higher in MoM-THA compared to HR (p 0.001). There was no significant difference in chromium levels (p = 0.313). (2) Cobalt is increasing over time in MoM-THA (p = 0.030) whereas metal ions remain stable in HR. (3) Metal ion levels were not affected by acetabular inclination angle and femoral component size in MoM-THA. Chromium levels correlate with the femoral component size (r = -0.240; p = 0.037), the UCLA activity score (r = -0.344; p = 0.003) and the VAS (r = 0.263; p = 0.38) in HR.Considering that HR and MoM-THA used the same MoM bearing design, increased cobalt levels may be related to trunnion wear or corrosion. Elevated cobalt levels should raise concern for corrosion related failure in MoM-THA.

We studied whether the presence of lateral osteophytes on plain radiographs was a predictor for the quality of cartilage in the lateral compartment of patients with varus osteoarthritic of the knee (Kellgren and Lawrence grade 2 to 3). The baseline MRIs of 344 patients from the Osteoarthritis Initiative (OAI) who had varus osteoarthritis (OA) of the knee on hip-knee-ankle radiographs were reviewed. Patients were categorised using the Osteoarthritis Research Society International (OARSI) osteophyte grading system into 174 patients with grade 0 (no osteophytes), 128 grade 1 (mild osteophytes), 28 grade 2 (moderate osteophytes) and 14 grade 3 (severe osteophytes) in the lateral compartment (tibia). All patients had Kellgren and Lawrence grade 2 or 3 arthritis of the medial compartment. The thickness and volume of the lateral cartilage and the percentage of full-thickness cartilage defects in the lateral compartment was analysed. There was no difference in the cartilage thickness or cartilage volume between knees with osteophyte grades 0 to 3. The percentage of full-thickness cartilage defects on the tibial side increased from < 2% for grade 0 and 1 to 10% for grade 3. The lateral compartment cartilage volume and thickness is not influenced by the presence of lateral compartment osteophytes in patients with varus OA of the knee. Large lateral compartment osteophytes (grade 3) increase the likelihood of full-thickness cartilage defects in the lateral compartment. Cite this article: Bone Joint J 2015;97-B:1634–9.

Increased age, obesity, and American Society of Anesthesiologists (ASA) Physical Status class III and IV have been reported as predictors for mortality and perioperative complications. High-volume institutions rely on central referral services as first contact point for patients. The current study reports on a simple four-step questionnaire to identify patients with ASA-physical status class III and IV to improve referral processes and optimize perioperative work ups. Seven hundred and seventy-five patients who called the physician referral service (PRS) at the author’s institution and subsequently underwent surgery were enrolled in this study. The answers to the initial PRS questionnaire were analyzed. The study cohort consisted of 414 women (53.4%) and 361 men (46.6%) with an average age of 61.4 years (range 44–90 years) at the time of surgery. Binary logistic regression revealed hypertension, diabetes mellitus (using medication), using blood thinner (other than Aspirin) and a number of 4–9 prescribed medication, respectively, as predictors for ASA III and IV. Receiver-operating characteristic (ROC) curve analysis identified a sensitivity of 82.4%, a specificity of 82.9%, and an accuracy of 82.8%, when two of these four questions are answered “yes”. The area under the curve for this analysis was 0.876 [95% confidence interval (CI) 0.845–0.908]. Positive and negative likelihood ratios were 4.8 (95% CI 4.0–5.8) and 0.2 (95% CI 0.1–0.3), respectively. This study revealed a simple four-step questionnaire to identify patients with ASA III or IV before a medical appointment. This helps to balance referrals between multiple providers in high-volume medical groups.

Malpositioning of the cup in total hip arthroplasty (THA) is associated with dislocation, early polyethylene wear, and impingement. The direct anterior approach (DAA) THA allows for intraoperative fluoroscopy imaging (IF). The current study investigates the following research hypotheses: (1) intraoperative measurements of radiographic cup inclination (RI) are reliable and reproducible. (2) A correction factor can compensate for the complex parallax effects when using IF. In 2016, 100 consecutive hips underwent primary THA utilizing DAA and IF for cup placement. RI was measured on intraoperative fluoroscopy images and postoperative AP pelvis radiographs. Determination of RI on IF images is reliable and reproducible (ICC 0.851–0.950). RI measurement on IF images had a good correlation with the corresponding postoperative RI on AP pelvis radiographs (r = 0.538, p

Background and purpose - Systematic comparisons of anterior approach (A) versus posterior approach (P) in primary total hip arthroplasty (THA) have largely focused on perioperative outcomes. In this systematic review with meta-analysis, we compared complication risk of A versus P in studies of primary THA with at least 1-year mean follow-up. Patients and methods - We performed a systematic review of prospective and retrospective studies with at least 1-year mean follow-up that reported complications of A and P primary THA. Complications included infection, dislocation, reoperation, thromboembolic event, heterotopic ossification, wound complication, fracture, and nerve injury. Random effects meta-analysis was used for all outcomes. Complication risk was reported as rate ratio (RR) to account for differential follow-up durations; values1 indicated higher complication risk with A and values1 indicated lower risk with A. Results - 19 studies were included; 15 single-center comparative studies with 6,620 patients (2,278 A; 4,342 P) and 4 multicenter registries with 157,687 patients (18,735 A; 138,952 P). Median follow-up was 16 (12-64) months) with A and 18 (12-110) months with P. Anterior approach was associated with lower rate of infection (RR =0.55, p = 0.002), dislocation (RR =0.65, p = 0.03), and reoperation (RR =0.84, p0.001). No statistically significant differences were observed in rate of thromboembolic event (RR =0.59, p = 0.5), heterotopic ossification (RR =0.63, p = 0.1), wound complication (RR =0.93, p = 0.8), or fracture (RR =1.0, p = 0.9). There was a higher rate of patient-reported nerve injury with A (RR =2.3, p = 0.01). Interpretation - Comparing A with P in primary THA, A was associated with lower risk of reoperation, dislocation, and infection, but higher risk of patient-reported nerve injury.

Distal femoral preparation and sizing are important for overall balancing and function.Femoral sizing and subsequent osseous resections can be performed with use of either an anterior or a posterior referencing technique.With the anterior referencing technique (that is, referencing the anterior and

The introduction of new materials and better implant coatings seems to provide the prerequisites for more intense physical activities after total joint arthroplasties of the lower extremity. Despite recent advances in implant design and materials, recommendations for sport after total joint arthroplasty have not been updated over the past 20 years. The introduction of modern uncemented fixation as well as highly cross-linked polyethylene into total hip arthroplasty allow for a more active life-style without an increased risk of loosening or complications. This publication reviews the literature and presents the current knowledge to provide guidelines for orthopaedic surgeons treating patients after total joint replacement surgery.Mit der Einführung neuer Materialien in die Hüft- und Knieendoprothetik, sowie der Verbesserung der Prothesenverankerung im Knochen, scheinen die Voraussetzungen für eine stärkere Belastung künstlicher Endoprothesen erfüllt. Die Empfehlungen hinsichtlich der sportlichen Betätigung nach Implantation einer Knie- oder Hüftprothese sind in den letzten 20 Jahren jedoch den implantattechnischen Verbesserungen nicht angepasst worden. Gerade in der Hüftendoprothetik erlaubt die heute bevorzugte Verwendung von unzementierten Implantaten sowie der Einzug von hoch vernetztem Polyethylen einen deutlich aktiveren Lebenswandel ohne das erhöhte Lockungsraten und Komplikationen befürchtet werden müssen. Die hier vorgestellte Veröffentlichung fasst den gegenwärtigen Kenntnisstand aus der Literatur zusammen und gibt dem operativ tätigen orthopädischen Chirurgen Leitlinien für eine individuelle Beratung des Patienten.

The enhanced posterior soft tissue repair has reduced the frequency of dislocation after primary THA performed through the posterolateral approach. However, the long-term integrity of the repair is unknown and could influence surgeon choice regarding surgical technique and THA approach.We asked: (1) What is the durability of the enhanced posterior soft tissue repair at a minimum of 49 months using MRI to evaluate soft tissue to bone integrity? (2) How does the appearance of the posterior soft tissues change during this time? (3) Are there patient characteristics associated with the long-term imaging appearance of the posterior repair?All patients without a contraindication for MRI who were undergoing unilateral primary uncemented THA through a posterior approach between February and May 2005 were eligible for inclusion. Ninety percent consented to participate (36 of 40 patients), and 30 patients were followed prospectively with MRI postoperatively and again at 3 months; of those, 22 (73%; 12 men, 10 women) completed the study by having another MRI study at a minimum of 49 months (mean, 51 months; range, 49-59 months). Each patient underwent metal-artifact-reduction sequence MRI to evaluate the integrity of the posterior soft tissues, which had been repaired anatomically during primary THA at a minimum of 4 years earlier. The results were compared with those of prior MR images obtained immediately after surgery and at 3 months postoperatively. All patients were given a self-reported modified Harris hip score at the time of the most recent MRI study (maximum score = 81).At latest followup, 21 of 22 (96%) patients had a posterior capsule in contact with bone, and 21 of 22 (96%) had an intact quadratus femoris. Twenty-one patients (96%) had soft tissue or a scar from the piriformis and conjoined tendons in continuity with bone. In these cases, the interface between the piriformis and conjoined tendons and the greater trochanter observed immediately postoperatively and at 3 months postoperatively became filled with hypointense tissue, with signal characteristics similar to tendon. Time from surgery was most associated with changes in native tendon-to-bone distances (p0.001) and MRI signal intensity of the repair (p0.001).At followup of just more than 4 years, the posterior capsule and quadratus femoris most often were healed to bone. In the majority of patients, scar tissue between the piriformis and conjoined tendons and bone matured to achieve orientation and signal intensity resembling native tendon. We believe the enhanced posterior soft tissue repair facilitates this process. Our results provide a plausible explanation for improved postoperative stability observed in patients receiving an enhanced soft tissue repair compared with those in whom a repair is not performed.Level IV, therapeutic study.

Fracture of a ceramic liner of a total hip arthroplasty is rare and is radiographically occult if not displaced. We report on two patients in whom ceramic liner fracture was radiographically occult but was diagnosed on subsequent CT scan through appropriate windowing.

Postoperative hip dislocations have been reported in 0.5 to 10.6 % of patients after primary posterolateral total hip arthroplasty (THA). Hip precautions are currently recommended for 6 weeks postoperatively to reduce early dislocation and facilitate healing of the posterior soft tissue repair. To determine the impact of a modified 4-week precaution protocol on the dislocation rate, 698 consecutive patients (797 hips) operated by a single surgeon between September 2008 and December 2012 were retrospectively evaluated. All patients had a standard THA using a minimal invasive posterior approach with posterior soft tissue repair and 28–36-mm head size. 98.7 % of the patients were available for follow-up. There were eight (1 %) dislocations in 797 hips in the first 12 months after surgery with 4 weeks of hip precautions. The average time to dislocation was 7.5 weeks after surgery (range 1.0–16.9 weeks); two dislocations (25 %) took place in the first 4 weeks. Shortening the time of posterolateral hip precautions from 6 to 4 weeks after surgery does not increase the risk of postoperative dislocation.

As the rate of revision total hip arthroplasty (THA) rises, attention must be paid to potential complications relating to bone loss, soft tissue deficiencies, and loss of tissue planes. Using modular femoral stems in revision surgery allows for varying amounts of bone loss in the proximal and distal femur while letting the surgeon adjust rotation, leg length, and offset. We retrospectively reviewed 125 patients that underwent revision THA with a modular femoral component system and had minimum 2 year follow-up. Ten patients required reoperations for infection, recurrent dislocation, or fracture treatment. There was no evidence of radiographic loosening or mechanical failure in the remaining patients. Modular femoral components provide excellent intraoperative flexibility and significant radiographic and clinical benefits as seen in this patient cohort.

The aim of this study is to determine whether the posterior–anterior (PA)-flexed view improves the radiographic assessment of patients with knee pain compared with the standard standing anterior–posterior radiograph. Three hundred and sixty-five patients with knee pain underwent anterior–posterior (AP), PA flexed, lateral, and Merchant radiographs of the knee. Knees were grouped as mild (Kellgren and Lawrence [K-L] 1–2) or severe (K-L 3–4) osteoarthritis (OA) and either varus (medial compartment), valgus (lateral compartment), or patellofemoral OA. In knees with mild valgus OA on AP view (K–L 1–2), the PA flexed view was more sensitive than the AP view. The measured lateral minimal joint space width (minJSW) decreased more than 2 mm in 68% of the patients, resulting in an increase in K–L grade (3 or 4). In patients with severe valgus OA and in all patients with varus and patellofemoral OA, there was no difference between AP and PA flexed view with regard to radiographic measurements or KL grade. Based on the Medicare reimbursement rate using the PA flexed view alone instead of both views reduced imaging costs by 47%. The PA flexed view better classifies the severity of lateral compartment disease in patients with mild valgus OA and provides comparable diagnostic sensitivity for joint space narrowing in varus- and patellofemoral OA. Using the PA flexed view alone was more cost effective than using the combination of AP and PA flexed imaging.

The choice between anterior approach (AA) and posterior approach (PA) in primary total hip arthroplasty (THA) is controversial. Previous reviews have predominantly relied on data from retrospective studies.This systematic review included prospective studies comparing postoperative outcomes through 90 days of AA vs PA in primary THA. Outcomes were pain severity, narcotic usage, hip function using Harris Hip Score, and complications. Random effects meta-analysis was performed for all outcomes. Efficacy data were reported as standardized mean difference (SMD) where values of 0.2, 0.5, 0.8, and 1.0 were defined as small, medium, large, and very large effect sizes, respectively. Complications were reported as the absolute risk difference (RD) where a positive value implied higher risk with AA and a lower value implied lower risk with AA.A total of 13 prospective comparative studies (7 randomized) with patients treated with AA (n = 524) or PA (n = 520) were included. The AA was associated with lower pain severity (SMD = -0.37, P .001), lower narcotic usage (SMD = -0.36, P = .002), and improved hip function (SMD = 0.31, P = .002) compared to PA. No differences between surgical approaches were observed for dislocation (RD = 0.2%, P = .87), fracture (RD = 0.2%, P = .87), hematoma (RD = 0%, P = .99), infection (RD = 0.2%, P = .85), thromboembolic event (RD = -0.9%, P = .42), or reoperation (RD = 1.3%, P = .26). Conclusions of this study were unchanged when subjected to sensitivity analyses.In this systematic review and meta-analysis of prospective studies comparing postoperative outcomes through 90 days of AA vs PA in primary THA, patients treated with AA reported less pain, consumed fewer narcotics, and reported better hip function. No statistical differences in complication rates were detected between AA and PA. Ultimately, the choice of surgical approach in primary THA should consider preference and experience of the surgeon as well as preference and anatomy of the patient.

The preoperative prediction of medical complications is essential to optimize perioperative management. SpineSage™ is a free of charge online calculator to predict medical complications in spine surgery. The current study utilizes it in patients undergoing spine surgery to assess whether the predicted risks would correlate with the actual complication rate in clinical practice.A total of 273 consecutive patients who underwent spinal surgery were assessed. The risk of medical complications was predicted for each patient, and all medical complications were recorded within 30 days of surgery. Based on their predicted risk of complication, patients were divided into three risk groups ( 15, 15-30, 30%).The predicted overall risk of medical complications was 14.7% and was comparable to the observed complication rate of 16.1%. The predicted risk for major medical complications (3.8%) was also similar to the observed complication rate (3.3%). Detailed analysis of the segmented risk groups suggests a close correlation between predicted and actual complication rates. Receiver operating characteristic analysis revealed an area under the curve of 0.71 (p 0.001) for the prediction of overall medical complications and 0.85 (p 0.001) for major complications.The online risk calculator predicted both overall and major medical complications. The tool can assist in preoperative planning and counseling of patients. These slides can be retrieved under Electronic Supplementary Material.

Revision of failed modular metal-on-metal total hip replacement (MoM-THA) can be technically difficult. A dual mobility liner can help to salvage a well-fixed acetabular component. The present paper reports the clinical and radiographic outcome of revision of failed Birmingham modular MoM-THA using a dual mobility liner. The present study reports on ten patients (3 female and 7 male) with 11 revision THAs. Patients underwent revision an average of 51 months (range 40–73 months) after index procedure. Mean follow-up after the revision was 31 months (range 24–37 months) and all patients underwent an MRI with metal artifact reduction software (MARS) at least two years after revision to assess for local polyethylene wear and osteolysis. The Harris Hip score improved from 92.2 (range 63.0–100.0) to 100.0 (p = 0.072). One patient had a one-time dislocation within seven days of surgery. No patient required additional surgeries. Radiographs showed no signs of component loosening and osteolysis and MRI imaging revealed no evidence of polyethylene wear or osteolysis. A dual mobility liner in an existing Birmingham cup can provide excellent clinical and radiological short-term results without MRI evidence of increased polyethylene wear. Post-operative hip precautions should be enforced.

The study analyzed the influence of synovitis on the histological and biomechanical properties of lateral-compartment cartilage. In a prospective cohort study, 84 patients (100 knees) with varus deformity of the knee were included. Osteochondral samples from the distal lateral femur underwent biomechanical and histologic analysis. Synovial tissue was sampled for histological (chronic synovitis score) and immunohistochemical evaluation of the degree of synovitis. CD15 (neutrophils), Ki-67 (dividing cells), and CD68 (macrophages) were tested in all synovial samples. While the histological synovitis score did not correlate with the degree of cartilage degeneration (histological OARSI grades), both CD15 (r

Periprosthetic infection remains one of the most serious complications following megaendoprostheses. Despite a large number of preventive measures that have been introduced in recent years, it has not been possible to further reduce the rate of periprosthetic infection. With regard to metallic modification of implants, silver in particular has been regarded as highly promising, since silver particles combine a high degree of antimicrobial activity with a low level of human toxicity. This review provides an overview of the history of the use of silver as an antimicrobial agent, its mechanism of action, and its clinical application in the field of megaendoprosthetics. The benefits of silver-coated prostheses could not be confirmed until now. However, a large number of retrospective studies suggest that the rate of periprosthetic infections could be reduced by using silver-coated megaprostheses.