Background

It has been suggested that routine follow-up of primary THR patients could be performed by GPs in primary care, rather than by orthopaedic specialists. Essential radiographic follow-up would likely be based on radiographic reports, rather than on inspection of the radiographs themselves.

Simultaneous bilateral total hip arthroplasties (THAs) present unique and unwarranted dangers to the patient and surgeon alike. These include a significantly increased risk of blood transfusion (up to 50% in contemporary series even with the use of tranexamic acid), longer operative times, longer length of stays, and higher mortality rates in patients with minimal risk factors (age > 75 years, rheumatoid arthritis, higher ASA class, and/or male sex). This is even in light of the fact that the vast majority of literature has a substantial selection bias in which only the healthiest, youngest, non-obese, and most motivated patients are included. Traditionally, simultaneous bilateral THAs were completed in the lateral decubitus position. This required the surgeon and surgical team to reposition the patient onto a fresh wound, as well as additional prepping and draping. To mitigate these additional limitations of simultaneous bilateral THAs, there has been a recent trend towards utilizing the direct anterior approach. However, this particular approach presents its own unique set of complications such as an increased risk of periprosthetic femoral fracture and early femoral failure, an increased risk of impaired wound healing (particularly in obese patients), potential injury to the lateral femoral cutaneous nerve with subsequent neurogenic pain, and traction-related neurologic injuries. When compounded with the risks of simultaneous bilateral THAs, the complication profile becomes prohibitive for an elective procedure with an otherwise very low morbidity

Introduction. Impingement of total hip arthroplasties (THAs) has been reported to cause rim damage of polyethylene liners, and in some instances has led to dislocation and/or mechanical failure of liner locking mechanisms in modular designs. Elevated rim liners are used to improve stability and reduce the risk of dislocation, however they restrict the possible range of motion of the joint, and retrieval studies have found impingement related damage on lipped liners. The aim of this study was to develop a tool for assessing the occurrence of impingement under different activities, and use it to evaluate the effects a lipped liner and position of the lip has on the impingement-free range of motion. MATERIALS & METHOD. A geometrical model incorporated a hemi-pelvis and femur geometries of one individual with a THA (DePuy Pinnacle® acetabular cup with neutral and lipped liners; size 12 Corail® stem with 32mm diameter head) was created in SOLIDWORKS (Dassault Systèmes). Joint motions were taken from kinematic data of activities of daily living that were associated with dislocation of THA, such as stooping to pick an object off the floor and rolling over. The femoral component was positioned to conform within the geometry of the femur, and the acetabular component was orientated in a clinically acceptable position (45° inclination and 20° anteversion). Variation in orientation of the apex of the lip was investigated by rotating about the acetabular axes from the superior (0°) in increments of 45° (0°−315°), and compared to a neutral liner. Results. When a lipped liner was used, implant (neck on acetabular rim) impingement was found to occur when performing sit-to-stand from a normal seat, leg cross and pivot, whereas no impingement occurred with a neutral liner. The presence and position of the lip reduced the impingement-free range of motion, compared to the neutral liner. Impingement occurred when the lip was positioned superiorly and anteriorly, when performing most of the activities that were prone to posterior dislocation, and posteriorly, posterior-superiorly and posterior-inferiorly when performing activities prone to anterior dislocation. During sit-to-stand from a normal seat no impingement occurred when a lipped or neutral liner was used. Bone impingement was observed when the performing the roll activity with both lipped and neutral liners. DISCUSSION. Impingement was observed more with lipped liners compared to neutral liners, this agrees with the findings of some clinical studies. The results indicate that the positioning of the lip influences the possible range of impingement-free motion. Considering this and the improved joint stability of using a lipped liner, a balance is required to achieve an optimal range of motion without increasing the risk of dislocation. This tool could potentially to be used to optimise lipped liner design and position, and could assist with the liner selection for patients based on their activities

Uncemented metal-on-polyethylene total hip arthroplasties (THAs) have had a modular cobalt-chrome alloy head since their introduction in the early 1980's. Retrieval analysis studies and case reports in the early 1990's first reported corrosion between the femoral stem trunnion (usually titanium alloy) and cobalt-chrome alloy femoral head. However, then this condition seemed to disappear for about two decades? There are now numerous recent case series of this problem after metal-on-polyethylene THA, with a single taper or dual taper modular femoral component. Metal ion elevation, corrosion debris, and effusion are caused by mechanically assisted crevice corrosion (MACC). These patients present with diffuse hip pain, simulating trochanteric bursitis, iliopsoas tendinitis, or even deep infection. Trunnion corrosion, with adverse local tissue reaction, is a diagnosis of exclusion, after infection, loosening, or fracture. The initial lab tests recommended are: ESR, CRP, and serum cobalt and chromium ions. With a metal-on-polyethylene THA, a cobalt level > 1ppb is abnormal. Plain radiographs are usually negative, but may show calcar osteolysis or acetabular erosion or cyst. MARS MRI may be the best imaging study to confirm the diagnosis. Hip aspiration for culture and cell-count may be necessary. The operative treatment is empiric, with debridement, and head exchange with a ceramic head-titanium sleeve (or oxidised zirconium head) placed on the cleaned trunnion. The femoral component may have to be removed if there is “whole trunnion failure”. This usually relieves the symptoms, but the complication rate of this procedure may be high

The Danish Hip Arthroplasty Register (DHR) is a national database on total hip arthroplasties (THAs) with a high completeness and validity of registration for primary procedures. The aim was to validate the registration in DHR for revisions due to Prosthetic Joint Infection (PJI). We identified a cohort of patients in the DHR who underwent primary THA from January 1, 2005 to December 31, 2012 and we followed these patients until first-time revision, death, emigration or December 31, 2012. The PJI diagnosis registered was tested against a gold standard encompassing information from microbiology, prescription, and clinical biochemistry registries in combination with clinical findings retrieved from medical records. We estimated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) with 95% confidence interval (CI) for PJI in DHR alone and in DHR combined with microbiology registries. Out of 37,828 primary THAs, 1,382 were registered with any revision, 232 of which were due to PJI. For PJI revisions in DHR, the sensitivity was 67.0% (CI: 61.0 – 72.6), specificity 95.2% (CI: 93.8 – 96.4), PPV 77.2% (CI: 71.2 – 82.4), and NPV 92.3% (CI 90.7 – 93.8). Combining DHR with microbiology registries led to a notable increased in the sensitivity for PJI revision to 90.3% (CI: 86.1 – 93.5) and likewise for specificity 99.6% (CI: 99.1 – 99.9), PPV 98.4% (CI: 95.9 – 99.6) and NPV 98.5% (CI: 97.6 – 99.1). Only two thirds of PJI revisions were captured in DHR and the PPV was moderate. However, combining DHR with microbiology registries improved the accuracy remarkably. The study was supported by Region of Southern Denmark and Lillebaelt Hospitals

Background/Purpose. Total hip arthroplasties (THAs) with ceramic bearings are widely performed in young, active patients and thus, long-term outcome in these population is important. Moreover, clinical implication of noise, in which most studies focused on ‘squeaking’, remains controversial and one of concerns unsolved associated with the use of ceramic bearings. However, there is little literature regarding the long-term outcomes after THAs using these contemporary ceramic bearings in young patients. Therefore, we performed a long-term study with a minimum follow-up of . 1. 5 years after THAs using contemporary ceramic bearings in young patients with osteonecrosis of the femoral head (ONFH) less than fifty. Materials and Methods. Among sixty patients (71 hips) with a mean age of 39.1 years, 7 patients (7 hips) died and 4 patients (4 hips) were lost before 15-year follow-up. The remaining 60 hips were included in this study with an average follow-up period of 16.3 years (range, 15 to 18). All patients underwent cementless THA using a prosthesis of identical design and a 28-mm third-generation alumina head by single surgeon. The clinical evaluations included the modified Harris hip score (HHS), history of dislocation and noise around the hip joint: Noise was classified into squeaking, clicking, grinding and popping and evaluated at each follow-up. Snapping was excluded through physical examination or ultrasonography. Radiographic analysis was performed regarding notching on the neck of femoral component, loosening and osteolysis. Ceramic fracture and survivorship free from revision were also evaluated. Results. The mean Harris hip score improved from 55.3 to 95.5 points (range, 83 to 100) at the time of the final follow-up. Seventeen patients (34.7%) reported noise around the hip joint: “squeaking” in one and “clicking” in 16 patients. Notching on the neck of femoral component suggesting impingement between neck and ceramic liner was demonstrated in 9 hips (15%) at average of 6.9 years postoperatively and located at 2 to 3.5 mm distal to edge of ceramic head. Although no chip fracture of ceramic ‘liner’ occurred, notching was associated with “clicking” sound (p<0.01). One patient who reported clicking sound underwent a revision THA because of ceramic ‘head’ fracture. Loosening, osteolysis or dislocation was not observed in any hip and survivorship free from revision at 5 years was 98%. Conclusion. Cementless THAs using 28-mm contemporary alumina ceramic head demonstrated excellent long-term outcome in young, active patients with ONFH. Despite this encouraging result, however, we remain concerned about ‘clicking’ sound, because we did observe it associated with notching on the neck of stem. Acknowledgement. This work was supported by Institute for Information & communications Technology Promotion (IITP) grant funded by the Korea government (MSIP) (#B0101-14-1081)

Metal-on-metal resurfacing offers an alternative strategy to hip replacement in the young active patient with severe osteoarthritis of the hip. The aim of this study was to compare functional outcomes, failure rates and impending revisions in hybrid total hip arthroplasties (THAs) and Birmingham Hip Resurfacings (BHRs) in young active patients. We compared the 5-7 year clinical and radiological results of the metal-on-metal BHR with hybrid THA in two groups of 54 hips each, matched for sex, age, body mass index and activity. Function was excellent in both groups as measured by the Oxford hip score (median 13 in the BHRs and 14 in the THAs, p=0.14), but the resurfacings had higher UCLA activity scores (median 9 v 7, p=0.001) and better EuroQol quality of life scores (0.90 v 0.78, p=0.003). The THAs had a revision or intention to revise rate of 8% and the BHRs 6%. Both groups demonstrated impending failure on surrogate end-points. 12% of THAs had polyethylene wear and osteolysis under observation, and there was femoral component migration in 8% of resurfacings. Polyethylene wear was present in 48% of hybrid hips without osteolysis. Of the femoral components in the resurfacing group which had not migrated, 66% had radiological changes of unknown significance (classification proposed). In conclusion, the early to mid-term results of resurfacing with the BHR appear at least as good as those of hybrid THA. Only by longer term follow-up will we establish whether the change of practice recorded here represents a true advance

Tracked B-mode ultrasound (US) potentially provides a non-invasive and radiation-free alternative to percutaneous pointer digitization for intra-operative determination of the anterior pelvis plane (APP). However, most of the published approaches demand a direct access to the corresponding landmarks, which can only be presumed for surgical approaches with the patient in supine position. In order to avoid any change of the clinical routine for total hip arthroplasties (THAs), we propose a new method to determine the pelvic orientation, which could be performed in lateral position. Our proposed method is based on the acquisition of ultrasound images of the ipsilateral hemi-pelvis, namely the posterior superior iliac spines (PSISs) and iliac crest region. The US images are tracked by a navigation system and further processed to extract three-dimensional point clouds. As only one side of the pelvis is accessible, we estimate the symmetry plane (midsagittal plane) of the pelvis based on additionally digitized bilateral anterior superior iliac spine (ASIS) landmarks. This symmetry plane is further used to mirror the ipsilateral US-derived points to the contralateral side of the pelvis and to register and instantiate a pelvic SSM constructed from 30 CT-scans. The proposed registration method was evaluated using two plastic pelvis models and two cadaveric pelvises together with special custom-made silicone phantoms to simulate the missing soft-tissue. In each trial, the required data were collected with the pelvis rigidly fixed in lateral decubitus position together with ground truth APP landmarks. A registration error of 3.48° ± 1.10° was found for the anteversion angle, while the inclination angle could be reconstructed with a mean error of 1.26° ± 1.62°. The performed in-vitro experiments showed reasonably good results, taking the sparsity of the input point clouds into consideration

Incorrect restoration of leg length (LL) and offset is a major source of patient dissatisfaction and dysfunction after total hip arthroplasties (THAs). Evaluations on anterior-posterior x-ray images are state-of-the-art to assess the accuracy of such techniques. However, x-ray based measurements of LL and offset are challenging and limited in terms of accuracy. Within this study, we evaluated the accuracy of such measurements by analysing a series of clinical data. We evaluated the results on the non-treated side, since we know that there should be no significant difference between pre- and postoperative measurements on this side. A series of 44 consecutive patients was analysed regarding changes in the difference between pre- and post-operative LL and offset measurements. Anterior-posterior x-rays were taken pre- (pre-OP) and post-operatively (post-OP) with a calibration by a scaling ruler (pre-OP) or implant size (post-OP). The LL and offset measurements were performed with a digital planning software based on the teardrop and transischial line. The distance between the teardrop/transischial line and the trochanter minor was measured to assess LL differences. Femoral offset (FO) was calculated as the orthogonal distance between the centre of the femoral head and the proximal shaft axis. Global offset (GO) was calculated as the distance between the inferior aspect of the teardrop figure and the shaft axis along the teardrop line. Descriptive statistics (mean value ± standard deviation) were calculated for the different types of measurements. Statistically significant differences were checked according to a student's t-test (α = 0.05). The differences between the pre-and post-operative situation was 0.8±3.2 mm for LL, 0.2±3.5 mm for GO, and −0.5±2.5 mm for FO when referencing to the teardrop line and 0.9±4.0 mm (LL) and −0.3±2.7 mm (FO) for the transischial line. The error distributions did not show statistically significant differences when referencing to the teardrop or transischial line. But high differences (0.1±6.6 mm) were found when comparing the LL values (teardrop vs. transischial) case-by-case. Within this study we demonstrated that x-ray based offset and LL measurements show reasonable inaccuracies. X-ray based evaluations of navigation-based techniques to assist LL and offset restoration cannot produce significantly better results than these analysed limits. That is, even if the navigation technique would be perfectly accurate, the evaluation would not achieve better accuracies than approximately ±3.5 mm for LL, ±3.5 mm for GO, and ±2.5 mm for FO

Limited postoperative range-of-motion (ROM) can lead to patient dissatisfaction and dislocation in total hip arthroplasties (THAs). To avoid this, femur first approaches have been developed which optimise particular aspects of ROM by using a virtual analysis of ROM. This study analysis whether it is possible to accurately assess ROM based on an intra-operative acquisition of anatomical structures by using an image-free navigation system. It compares the outcome of a collision detection algorithm when using 3d models from computerised tomography (CT) scans on the one side and intra-operatively acquired 3D models on the other side within a cadaver study. It focuses on peri-acetabular impingements. During the cadaver session 14 hips (7 cadavers) were treated surgically by using press-fit implants. 3D models of the pelvis and femora were generated based on segmented pre-operative CT data sets. Intra-operative data acquisition was performed by using a CT-free navigation software. Beside standard landmarks, points at the acetabular rim and femoral resection plane were acquired. For assessing ROM, a 3D model of the pelvis was generated. The information about the femoral resection plane was directly entered into the collision detection algorithm. 3D Computer Aided Design (CAD) models provided by the implant manufacturer were used for the implants. Based on this setup, the ROM values for flexion (FLEX), external rotation at 0° flexion (EXT), and internal rotation at 90° flexion (INTROT90) were compared. Differences within intended ROM were considered relevant, since the goal was to enable the prevention of clinically relevant ROM limitations. The average difference between the CT based and navigation data based ROM analysis was 2.13° ± 3.11° for FLEX, 3.33° ± 5.51° for EXT, and 1.6° ± 3.66° INTROT90. The values reduce to 1.58° ± 2.78° (FLEX) and 0.91° ± 3.77° (INTROT90) when only ROM values within the intended ROM are considered. For EXT all ROM values lied above the threshold for intended ROM. Thus, no relevant differences were found for this motion direction. In this study, a real-time collision detection based approach was developed and evaluated, which allows to virtually detect prosthetic and bony impingements. It was shown that ROM can be assessed accurately based on an image-free navigation technique. This information can be used intra-operatively to adjust the position of the implants and thus avoid postoperative ROM limitations. In particular, it enables a comprehensive femur first approach which allows us to optimise the post-operative results regarding functional parameters like ROM

Aims

In the UK, the NHS generates an estimated 25 megatonnes of carbon dioxide equivalents (4% to 5% of the nation’s total carbon emissions) and produces over 500,000 tonnes of waste annually. There is limited evidence demonstrating the principles of sustainability and its benefits within orthopaedic surgery. The primary aim of this study was to analyze the environmental impact of orthopaedic surgery and the environmentally sustainable initiatives undertaken to address this. The secondary aim of this study was to describe the barriers to making sustainable changes within orthopaedic surgery.

Aims

There is little published on the outcomes after restarting elective orthopaedic procedures following cessation of surgery due to the COVID-19 pandemic. During the pandemic, the reported perioperative mortality in patients who acquired SARS-CoV-2 infection while undergoing elective orthopaedic surgery was 18% to 20%. The aim of this study is to report the surgical outcomes, complications, and risk of developing COVID-19 in 2,316 consecutive patients who underwent elective orthopaedic surgery in the latter part of 2020 and comparing it to the same, pre-pandemic, period in 2019.

Aims

This study aimed to identify patients receiving total hip arthroplasty (THA) for trauma during the peak of the COVID-19 pandemic in the UK and quantify the risks of contracting SARS-CoV-2 virus, the proportion of patients requiring treatment in an intensive care unit (ICU), and rate of complications including mortality.

Aims

Currently, there is no single, comprehensive national guideline for analgesic strategies for total joint replacement. We compared inpatient and outpatient opioid requirements following total hip arthroplasty (THA) versus total knee arthroplasty (TKA) in order to determine risk factors for increased inpatient and outpatient opioid requirements following total hip or knee arthroplasty.