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Proponents of the direct anterior approach (DAA) for THA claim patients recover faster compared to primary THA through the posterior approach (PA). Blood loss and transfusion have substantially declined with the use of tranexamic acid (TXA). However, it is still controversial if hemoglobin drops and transfusion rates are affected by the surgical approach when TXA is routinely used. 2418 patients undergoing DAA THA were matched 1:1 with patients undergoing PA THA according to preoperative hemoglobin (± 1 g/dl), age (± 5 years), sex, BMI (± 5 kg/m2) and year of surgery (± 2 years). All patients received perioperative TXA. None of the patients donated autologous blood. Hemoglobin levels, drain placement and output, blood transfusion rates and volume as well as length of stay were recorded. A closed suction drain was used in 121 (5.0%) DAA and in 135 (5.6%) PA THAs (p = 0.369). Mean drain output was higher in the DAA compared to the PA group (134 ml (0–520 ml) versus 92.3 ml (0–600 ml), p = 0.004). There was no difference in hemoglobin drop [2.6 g/dl versus 2.6 g/dl (p = 0.143)] and transfusion rate [n = 31 (1.3%) versus n = 29 (1.2%), p = 0.793)] between DAA and PA THA. Mean transfusion amounts were 421.8 ml (250–1120.8 ml) in the DAA and 353.9 ml (250-560 ml) in the PA group (p = 0.801). The length of stay was shorter in the DAA group with a mean 1.6 days versus 2.1 days in the PA group (p ≤ 0.001). In this large matched cohort study, there was no difference in the perioperative hemoglobin drop, the transfusion rate and the transfusion amount between DAA and PA THA.

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.

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 (

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

Introduction: In acute COVID-19, D-Dimer levels can be elevated and those patients are at risk for thromboembolic events. This study aims to investigate differences in preoperative D-Dimer levels in SARS-CoV-2 IgG positive and negative patients undergoing primary total knee and total hip replacement (TJA) or spine surgery. Methods: D-Dimer levels of 48 SARS-CoV-2 IgG positive and 718 SARS-CoV-2 IgG negative spine surgery patients were compared to those of 249 SARS-CoV-2 IgG positive and 2102 SARS-CoV-2 IgG negative TJA patients. Patients were assigned into groups based on D-Dimer levels as follows: 400 ng/mL D-Dimer Units (DDU). Results: D-Dimer levels did neither differ significantly between SARS-CoV-2 IgG positive spine surgery patients and TJA patients (p = 0.1), nor between SARS-CoV-2 IgG negative spine surgery and TJA patients (p = 0.7). In addition, there was no difference between SARS-CoV-2 IgG positive and negative spine surgery patients and SARS-CoV-2 IgG positive and negative TJA patients (p = 0.3). Conclusions: There is no difference in D-Dimer levels between SARS-CoV-2 IgG positive and negative patients and there does not seem to be any difference for different orthopedic specialty patients. Routine testing of D-Dimer levels is not recommended for patients undergoing elective orthopedic surgery.

Introduction In the acute phase of COVID-19, elevated d-dimer levels indicate a hypercoagulable state putting the patients at increased risk for venous thromboembolic disease (VTE). It is unclear, if prior COVID-19 disease increases the risk for VTE after total joint arthroplasty (TJA) and if d-dimer levels can be used to identify patients at risk. Materials and methods d-Dimer levels of 313 consecutive SARS-CoV-2 IgG-positive and 2,053 -negative patients undergoing TJA between 05/20 and 12/20 were evaluated. d-Dimer levels were divided into three groups: 400 ng/ml d-dimer units (DDU). 277 SARS-CoV-2 IgG-positive patients underwent a Doppler ultrasound to rule out deep-vein thrombosis (DVT) 4–6 weeks after TJA. Results d-Dimer levels did not differ significantly between SARS-CoV-2 IgG-positive and -negative patients (p value 0.53). Among SARS-CoV-2 IgG-negative patients, 1687 (82.17%) had d-dimer levels 400 ng/ml. Of the SARS-CoV-2 IgG-positive patients, 257 (83.71%) had d-dimer levels 400 ng/ml. A postoperative DVT was detected in nine patients (2.9%) in the SARS-CoV-2 IgG-positive group and a PE in one patient (0.3%). 7/229 patients with 400 ng/ml had a DVT or PE (p = 0.43). Conclusions The findings of this investigation suggest there is no difference in d-dimer levels between SARS-CoV-2 IgG-positive and -negative patients undergoing TJA. Although there is a trend for increased VTE rates with increased d-dimer levels, routine d-dimer testing is not recommended based on the current data. SARS-CoV-2 IgG-positive patients have a low risk of VTE in the current study.

Increased cobalt (Co) and chromium (Cr) serum levels are one reason for revision surgery in metal on metal (MoM) total hip arthroplasty (THA) patients. Dual mobility liners are a simple revision option; however, they preserve the metal shell and stem and it is therefore not clear if metal ion levels will fully normalize after revision surgery. Between April 2013 and December 2017 25 hips (24 patients) underwent revision from a MoM THA to an off-label dual mobility liner. Five patients were lost to follow-up and one patient refused leaving 18 patients (11 men, 7 female, average age 63.9 years) for pre- and postoperative metal ion level blood tests at a minimum follow-up of 2 years. Fourteen patients were revised for osteolysis, two for elevated metal ion levels and two for fluid or cysts around the femoral or acetabular component. The average preoperative Co and Cr levels were 8.3 µg/l and 5.0 µg/l, respectively. At a minimum follow-up of 2 years (30–95 months), metal ions dropped to 0.8 µg/l. Harris Hip Score (HHS), Hip Osteoarthritis Outcome Score (HOOS), Visual Analog Scale (VAS) and the UCLA activity score improved non-significantly from pre- to postoperative. There was one postoperative complication in the study cohort. One patient with persisting pain required revision surgery to a standard acetabular component during the follow-up period. The off-label use of a dual-mobility liner in the current study resulted in normalization of the metal ion levels suggesting that preserving the cobalt-chromium acetabular component has little impact on ion levels. In addition, dual mobility liners have a low complication and revision rate.

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

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.

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.

Fracture of a well-ingrown femoral component is a rare and often challenging complication. Modular junctions and sleeve interfaces have been identified as one potential point of weakness with corrosion and fretting being contributing factors to ultimate femoral component fracture. Stem fractures at the sleeve interface were reported occasionally for the proximal ingrowth modular Emperion System (Smith and Nephew, Memphis, TN). However, this failure mechanism has been reported infrequently, often associated with corrosion at the modular junction, for the similarly designed S-ROM system (DePuy Orthopedics Inc., Warsaw, IN). We present the case of a 52-year-old patient, with a body weight of 84 kg (185 lbs) and a body mass index of 30.6 kg/m2, who suffered a fatigue fracture of a 14 × 09 × 130 mm S-ROM stem 42 months after implantation. The present study presents the results of the surface analysis, discusses possible failure mechanisms, provides treatment guidelines, and a review of the literature revealing 15 cases of failure at the level of the stem-sleeve junction. In particular, modifiable risk factors for potential stem failure, including stem diameter, stem offset, and the resulting cantilever bending forces on the proximal sleeve-stem junction, are discussed in detail. Keywords: Stem fracture, Removal technique, Breakage, Failure, Corrosion

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; values >1 indicated higher complication risk with A and values

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.

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

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

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).

In histopathologic SLIM diagnostic (synovial-like interface membrane, SLIM) apart from diagnosing periprosthetic infection particle identification has an important role to play. The differences in particle pathogenesis and variability of materials in endoprosthetics explain the particle heterogeneity that hampers the diagnostic identification of particles. For this reason, a histopathological particle algorithm has been developed. With minimal methodical complexity this histopathological particle algorithm offers a guide to prosthesis material-particle identification. Light microscopic-morphological as well as enzyme-histochemical characteristics and polarization-optical proporties have set and particles are defined by size (microparticles, macroparticles and supra- macroparticles) and definitely characterized in accordance with a dichotomous principle. Based on these criteria, identification and validation of the particles was carried out in 120 joint endoprosthesis pathological cases. A histopathological particle score (HPS) is proposed that summarizes the most important information for the orthopedist, material scientist and histopathologist concerning particle identification in the SLIM.

There is little data on whether preexisting allergies to implant materials and bone cement have an impact on the outcome of TKA.This review article analyzes the current literature to evaluate the prevalence and importance of metal and cement allergies for patients undergoing total knee arthroplasty.A review of the literature was performed using the following search criteria: "knee," "arthroplasty," and "allergy" as well as "knee," "arthroplasty," and "hypersensitivity."One hundred sixteen articles were identified on PubMed, Seventy articles could be excluded by reviewing the title and abstract leaving 46 articles to be included for this review. The majority of the studies cited patch testing as the gold standard for screening and diagnosis of hypersensitivity following TKA. There is consensus that patients with self-reported allergies against metals or bone cement and positive patch test should be treated with hypoallergenic materials or cementless TKA. Treatment options include the following: coated titanium or cobalt-chromium implants, ceramic, or zirconium oxide implants.Allergies against implant materials and bone cement are rare. Patch testing is recommended for patients with self-reported allergies. The use of special implants is recommended for patients with a confirmed allergy.

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

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.

Incidence of revision total knee arthroplasty is growing. Revision surgery aims at preserving the collateral ligaments to minimize implant constraint and stress on the implant-cement-bone interface. Exposure in the stiff knee can be challenging as a result of loss of soft tissue elasticity and capsular scarring brought on by multiple surgeries. If a quadriceps snip does not provide adequate visualization a quadriceps turndown or a tibial tubercle osteotomy is recommended to improve exposure. Such extensile approaches have various limitations and might risk compromising the extensor mechanism, recovery time, bone fixation, or wound healing. The current case report describes a novel technique to combine a quadriceps snip with cutting the medial collateral ligament to gain exposure. While patients require a hinged implant, the integrity of the extensor mechanism is preserved. This allows for immediate active and passive range of motion and places this approach at an advantage over a quadriceps turndown or tibial tubercle osteotomy.

After total hip replacement surgery, patients are eager to resume the activities of daily life, particularly driving. Most surgeons recommend waiting 6 weeks after surgery to resume driving; however, there is no evidence to indicate that patients cannot resume driving earlier.Our purpose was to evaluate when in the recovery period following THA that patients regain or improve upon their preoperative braking reaction time, allowing them to safely resume driving.We measured and compared pre- and postoperative braking reaction times of 90 patients from 3 different surgeons using a Fully Interactive Driving Simulator (Simulator Systems International, Tulsa, OK). We defined a return to safe braking reaction time as a return to a time value that is either equal to or less than the preoperative braking reaction time.Patients tested at 2 and 3 weeks after surgery had slower braking reaction times than preoperative times by an average of 0.069 and 0.009 s, respectively. At 4 weeks after surgery, however, patients improved their reaction times by 0.035 s (p = 0.0398). In addition, at 2, 3, and 4 weeks postoperatively, the results also demonstrated that patient less than 70 years of age recovered faster.Based upon the results of this study, most patients should be allowed to return to driving 4 weeks following minimally invasive primary total hip arthroplasty.

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.

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.

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 aim of this prospective study was to determine the clinical value of lateral radiographs and corresponding MRI scans in the preoperative evaluation of the functional integrity of the anterior cruciate ligament (ACL) in a consecutive series of 78 patients (93 knees) with medial compartment osteoarthritis. All knees received standardised radiographs and MRI imagery. The wear pattern on the lateral radiograph was described based on a modified Keyes classification. On MRI, the ACL and the percentage of intact posterior cartilage in relation to the anteroposterior tibia width were assessed. The MRI showed an intact ACL in 23 (25 %) knees, evidence of ACL degeneration in 54 (58 %) knees and a complete ACL tear in 16 (17 %) knees. All knees with an intact ACL showed ≥14 % intact posterior cartilage on sagittal MRI scans, except for one knee. All knees with a torn ACL demonstrated

Reducing allogeneic blood transfusions remains a challenge in total knee arthroplasty. Patients with preoperative anemia have a particularly high risk for perioperative blood transfusions. 176 anemic patients (Hb

We investigated the effectiveness of non-image-guided hip injections. We retrospectively evaluated 369 intra-articular hip injections in 331 patients using anatomical landmarks. The percentage and duration of pain relief was documented. Hip injections were grouped in responders and nonresponders (50 % maximum pain relief as a cut off). In 82% (n = 304) of hip injections, patients responded positively and experienced >50 % pain relief. Nonresponders had a significantly higher body mass index (p = 0.007). Hip injections using anatomical landmarks are an effective treatment option for patients with osteoarthritis of the hip.

Background and Objectives A feared complication of spinal or epidural anesthesia is the development of epidural or spinal hematoma with subsequent neural element compression. Most available data are derived from the obstetric literature. Little is known about the frequency of hematoma occurrence among patients undergoing orthopedic joint arthroplasty, who are usually elderly and experience significant comorbidities. We sought to study the incidence of clinically significant lesions after spinal and epidural anesthesia and further describe their nature. Methods We retrospectively analyzed a database of all patients who underwent total hip or total knee arthroplasty under neuraxial anesthesia at our institution between January 2000 and October 2010. Patients with radiographically confirmed epidural lesions were identified and further analyzed. Results A total of 100,027 total knee and hip replacements under neuraxial anesthesia were performed at our institution. Ninety-seven patients underwent imaging studies to evaluate perioperative neurologic deficits (0.96/1000; 95% confidence interval, 0.77–1.16/1000). Eight patients were identified with findings of an epidural blood or gas collection (0.07/1000; 95% confidence interval, 0.02–0.13/1000). No patients receiving only spinal anesthesia were affected. All patients diagnosed with hematoma took at least 1 drug that potentially impaired coagulation (5 nonsteroidal anti-inflammatory agents, 1 a tricyclic antidepressant, and 1 an antiplatelet drug). No patient incurred persistent nerve damage. Conclusions The incidence of epidural/spinal complications found in this consecutive case series is relatively low but higher than previously reported in the nonobstetric population. Further research using large data sets could quantify the significance of some of the potentially contributing factors observed in this study.

Purpose Unicompartmental knee arthroplasty (UKA) can be a surgical treatment option for patients with high expectations regarding the post-operative level of physical activity. A systematic review was undertaken to answer three research questions: (1) is there an improvement of physical activity based on validated activity scores following UKA? (2) What are the sport disciplines and the sport patterns of UKA patients? (3) What are the pre- and post-operative sport participation rates and the return to activity rates of UKA patients? Methods Following the PRISMA guidelines, EMBASE, MEDLINE, ISI Web of Science and the Cochrane Central Register of Controlled Trials were searched for studies reporting the level of sport and/or physical activity before and after UKA, and/or included at least one activity score before and after UKA. Results Seventeen studies were identified reporting on 2972 UKAs, of which 89 % were medial UKAs and 92 % were mobile-bearing implants, respectively. Ten studies reported a statistically significant improvement of physical activity following UKA according to the UCLA activity score, the Tegner activity score or the High Activity Arthroplasty Score, respectively. Hiking, cycling and swimming are the most common activities following UKA. Sport participation before the onset of restricting symptoms ranged from 64 to 93 % and slightly decreased by 2–9 % following UKA. The return to activity rate ranged from 87 to 98 %. Conclusion Patients following UKA are physically active according to validated activity scores. A significant increase in low-impact activities and a decrease in high-impact activities after UKA was observed. Patients with a UKA regularly participate in sports; however, sport participation slightly decreased compared to pre-arthritic levels. This systematic review helps physicians to manage the expectations of patients regarding the level of physical activity following UKA. Level of evidence III.

Arthroscopic femoral osteoplasties might be technically demanding, might cause prolonged operative times and restrict the intraoperative overview. An automated navigated matching process of preoperative CT-data and intraoperative fluoroscopy should allow for noninvasive registration for FAI-surgery.Six hip joints were used with a conventional navigation system. Defined osseous lesion (2 × 2 mm) in the femoral neck, head neck junction, and head region were created followed by automated segmentation including CT-fluoro image fusion by the navigation system. Precision of registration process was tested trough a lateral arthroscopic portal. In vivo distances between pointer tip to bone were measured. Secondary in vivo distances between an inserted navigated shaver and the osseous lesions were measured.Our results allow a CT-fluoroscopy matching procedure for noninvasive registration process for navigated FAI-surgery in multiplanar planes. Precision is more accurate at the femoral neck and head-neck junction than at the femoral head area.Future navigated applications might simplify and increase precision of FAI-surgery.

Many patients have difficulty with pain control after transition from patient-controlled analgesia modalities to oral analgesics. The creation of a Recuperative Pain Medicine (RPM) service was intended to bridge this gap in pain management at the Hospital for Special Surgery. Specific goals were to improve patient and staff satisfaction with management of postoperative oral analgesics by improving clinical care, administrative policies, and patient and staff education. Primary outcome measures for improved satisfaction were Press Ganey surveys and staff surveys. From inception in Aug 2007 to Dec 2008, RPM has seen 6,305 patients for discharge planning and education and 997 patients for pain management consultation. Administrative and educational accomplishments have included creation of a patient "Helpline" for emergent phone questions regarding postdischarge home pain medications, a policy for prescribing pain medications for home discharge, patient education booklets, a pain management webpage on the Hospital for Special Surgery website, and direct education of staff. Press Ganey measurements of patient satisfaction increased from 87th percentile up to the 99th percentile among peer institutions since the implementation of RPM. Staff satisfaction was 92% positive regarding the RPM service's function and patient management. An RPM appears to be an effective means to optimize postoperative pain management after transition off patient-controlled analgesia devices. Further research is needed to ascertain the exact cost-benefit and potential impact on postoperative quality-of-life measurements.

Postoperative alignment is a predictor for long-term survival of total knee arthroplasty (TKA). The purpose of this study was to evaluate whether or not preoperative deformities predispose to intraoperative malposition of TKA components. A retrospective radiographic analysis of 53 primary TKA cases was performed. Preoperative AP hip to ankle and lateral knee radiographs were compared with postoperative views to evaluate component positioning. The following angles were measured: the hip–knee–ankle (HKA) angle expressing the mechanical axis of the leg, the mechanical lateral distal femur angle (mLDFA), the medial proximal tibia angle (MPTA), the posterior distal femur angle (PDFA), and the posterior proximal tibia angle (PPTA). Postoperative measurement of the HKA revealed 34.0% of the cases had a deviation of >±3° from neutral alignment. Sixteen knees (30.2%) were in varus and, with one exception, all presented with severe varus gonarthrosis prior to surgery with a mean tibiofemoral angle of 12.4° compared with 1.0° of valgus in the optimally aligned group. Patients (93.3%) with preoperative valgus malalignment showed optimal postoperative HKA. Odds ratios for malalignment of TKA for varus knees in comparison with valgus knees were 7.1 for HKA, 2.4 for MPTA, 4.9 for PDFA, and 1.7 for PPTA. The overall number of outliers in the presented data corresponds well with reports from other authors using different implants and guide systems. The presented data indicate that patients with preoperative varus alignment have a higher risk of postoperative implant malposition than patients with valgus alignment. The data supports that preoperative varus deformity predisposes to varus malposition of TKA. The risk for intraoperative malposition is significantly lower in valgus knees.

Although posterior capsule repair reduces the incidence of dislocation after THA, radiographic imaging studies suggest a high failure rate of the repair. Using MRI, we prospectively followed patients to evaluate the integrity of the posterior soft tissue repair after primary THA. Thirty-six patients (21 men, 15 women) underwent arthroplasty using a standard posterior approach. The posterior capsule and external rotators were repaired as separate layers using nonabsorbable sutures through two drill holes in the greater trochanter. Patients observed postoperative hip precautions for 6 weeks after surgery. All patients underwent initial MRI between postoperative Days 2 and 4. Thirty patients returned for followup MRI 3 months after surgery. At 3 months followup, the posterior capsule remained intact in 27 of 30 patients (90%) and the quadratus femoris repair remained intact in 29 of 30 patients (97%). Thirteen of 30 piriformis tendon repairs (43%) and 17 conjoined tendon repairs (57%) showed a gap between the hypointense tendon end and the greater trochanter greater than 25 mm. Our data show repaired posterior soft tissues provide a biologic scaffold allowing formation of a posterior pseudocapsule.