Polyethylene wear represents a significant risk factor for the long-term success of knee arthroplasty [1]. This work aimed to develop and in vivo validate an automated algorithm for accurate and precise AI based wear measurement in knee arthroplasty using clinical AP radiographs for scientifically meaningful multi-centre studies. Twenty postoperative radiographs (knee joint AP in standing position) after knee arthroplasty were analysed using the novel algorithm. A convolutional neural network-based segmentation is used to localize the implant components on the X-Ray, and a 2D-3D registration of the CAD implant models precisely calculates the three-dimensional position and orientation of the implants in the joint at the time of acquisition. From this, the minimal distance between the involved implant components is determined, and its postoperative change over time enables the determination of wear in the radiographs. The measured minimum inlay height of 335 unloaded inlays excluding the weight-induced deformation, served as ground truth for validation and was compared to the algorithmically calculated component distances from 20 radiographs. With an average weight of 94 kg in the studied TKA patient cohort, it was determined that an average inlay height of 6.160 mm is expected in the patient. Based on the radiographs, the algorithm calculated a minimum component distance of 6.158 mm (SD = 81 µm), which deviated by 2 µm in comparison to the expected inlay height. An automated method was presented that allows accurate and precise determination of the inlay height and subsequently the wear in knee arthroplasty based on a clinical radiograph and the CAD models. Precision and accuracy are comparable to the current gold standard RSA [2], but without relying on special radiographic setups. The developed method can therefore be used to objectively investigate novel implant materials with meaningful clinical cohorts, thus improving the quality of patient care

Introduction. By utilising the inherent variability achievable with circular frames, surgeons can manage a wide spectrum of complex injuries, and can deal with deformity at multiple levels, in multiple planes. The aim of this study was to assess functional outcomes utilising patients reported outcome measures (PROMs) of patients being treated with circular (Ilizarov) frame fixation for complex lower limb injuries and assess these results in conjunction with the observed postoperative alignment of the patients’ limbs. Materials & Methods. Cases were identified using a prospectively collected database of adult patients presenting between July 2018 and August 2021. Functional outcomes were assessed using the American Orthopaedic Foot and Ankle Score (AOFAS), the 5-level EQ-5D (EQ5D5L), the Lysholm Knee Scoring Scale (LKSS), the Olerud-Molendar Ankle Score (OMAS), and the Tegner Activity Scale (TAS). Postoperative radiographs were analysed for fracture union and to quantify malunion (as described in Dror Paleys Principles of Deformity Correction). Results. The mean AOFAS, EQ5D5L, LKSS and OMAS scores showed an initial drop from pre-op to early time points and then steady increase over the early, mid, late and frame-off time points, with a resultant score higher than pre-op. Malunion was found in 35 (41.7%) patients, 7 patients had a malunion within 5 degrees of normal, 15 from 5–10 degrees of normal, 12 from 10–15 degrees of normal and 2 out with 15 degrees of normal. Conclusions. Circular frame fixation is an attractive option in complex lower limb trauma where alternative fixation methods are unsuitable. Whilst post-operative success to the surgeon might be determined radiographically, patient reported outcomes give a functionally important, objective measure of the success of the surgery to the patient

Management of acetabular fractures in the elderly population remains somewhat controversial in regards to when to consider is open reduction internal fixation (ORIF) versus acute primary total hip. study aims to (1) describe outcome of this complex problem and investigate predictors of successful outcome. This retrospective study analyzes all acetabular fractures in patients over the age of 60, managed by ORIF at a tertiary trauma care centre between 2007 and 2018 with a minimum follow up of one year. Of the 117 patients reviewed, 85 patients undergoing ORIF for treatment of their acetabular fracture were included in the analysis. The remainder were excluded based management option including acute ORIF with THA (n=10), two-stage ORIF (n=2), external fixator only (n=1), acute THA (n=1), and conservative management (n=1). The remainder were excluded based on inaccessible medical records (n=6), mislabelled diagnosis (n=6), associated femoral injuries (n=4), acetabular fracture following hemiarthroplasty (n=1). The mean age of the cohort is 70±7 years old with 74% (n=62) of patients being male. Data collected included: demographics, mechanism of injury, Charlson Comorbidity Index (CCI), ASA Grade, smoking status and reoperations. Pre-Operative Radiographs were analyzed to determine the Judet and Letournel fracture pattern, presence of comminution and posterior wall marginal impaction. Postoperative radiographs were used to determine Matta Grade of Reduction. Outcome measures included morbidity-, mortality- rates, joint survival, radiographic evidence of osteoarthritis and patient reported outcome measures (PROMs) using the Oxford Hip Score (OHS) at follow-up. A poor outcome in ORIF was defined as one of the following: 1) conversion to THA or 2) the presence of radiographic OA, combined with an OHS less than 34 (findings consistent with a hip that would benefit from a hip replacement). The data was analyzed step-wise to create a regression model predictive of outcome following ORIF. Following ORIF, 31% (n=26) of the cohort had anatomic reduction, while 64% (n=54) had imperfect or poor reduction. 4 patients did not have adequate postoperative radiographs to assess the reduction. 31 of 84 patients undergoing ORIF had a complication of which 22.6% (n=19) required reoperation. The most common reason being conversion to THA (n=14), which occurred an average of 1.6±1.9 years post-ORIF. The remainder required reoperation for infection (n=5). Including those converted to THA, 43% (n=36) developed radiographic OA following acetabular fracture management. The mean OHS in patients undergoing ORIF was 36 ± 10; 13(16%) had an OHS less than 34. The results of the logistic regression demonstrate that Matta grade of reduction (p=0.017), to be predictive of a poor outcome in acetabular fracture management. With non-anatomic alignment following fixation, patients had a 3 times greater risk of a poor outcome. No other variables were found to be predictive of ORIF outcome. The ability to achieve anatomic reduction of fracture fragments as determined by the Matta grade, is predictive of the ability to retain the native hip with acceptable outcome following acetabular fracture in the elderly. Further research must be conducted to determine predictors of adequate reduction in order to identify candidates for ORIF

Introduction. Orientation of the acetabular component in total hip arthroplasty has been shown to influence component wear, stability, and impingement. Freehand placement of the component can lead to widely variable radiographic outcomes. Accurate abduction, in particular, can be difficult in the lateral decubitus position due to limited ability to appreciate and control positional obliquity of the pelvis. A CT-based mechanical navigation device has been shown to decrease cup placement error. This is an independent report of a single-surgeon's radiographic results using the device to control cup abduction. Patients and Methods. Sixty-four (64) consecutive elective THRs in 58 patients were performed via a supercapsular percutaneously-assisted (SuperPATH) surgical approach. Intraoperatively, the acetabular components were aligned with the aid of the CT-based mechanical navigation device (HipXpert; Surgical Planning Associates, Medford, MA). The cup orientation was then further adjusted to ensure that the anterior rim of the acetabular component was not prominent to avoid psoas impingement. Postoperatively, radiographic abduction was measured on standing postoperative radiographs. Results. Measured on standing postoperative radiographs, the cup radiographic abduction angle averaged 42.7° with a standard deviation of ± 3.9° and a range of 35° to 51°. Conclusions. Total hip arthroplasty using a CT-based navigation device as a guide for abduction led to cup implantation within a very narrow abduction range. This navigation device deserves more widespread interest and study, as acetabular component malposition remains a major concern in THR

Slipped capital femoral epiphysis (SCFE) is traditionally treated with in situ fixation using a threaded screw, leading to physeal arrest while stabilizing the femoral head. Recently, there has been interest in alternative methods of fixation for SCFE, aiming to allow growth and remodelling of the femoral neck postoperatively. One such option is the Free Gliding SCFE Screw (Pega Medical), which employs a telescopic design intended to avoid physeal compression. The objective of this study is to evaluate radiographic changes of the proximal femur following in situ fixation using the Free Gliding SCFE Screw. This study retrospectively evaluated 28 hips in 14 consecutive patients who underwent in situ hip fixation using the Free Gliding SCFE Screw between 2014 and 2018. Initial postoperative radiographs were compared to last available follow-up imaging. Radiographic assessment included screw length, articulotrochanteric distance (ATD), posterior sloping angle (PSA), alpha angle, head-neck offset (HNO) and head-shaft angle (HSA). Of the 28 hips reviewed, 17 were treated for SCFE and an additional 11 treated prophylactically. Average age at surgery was 11.7 years, with an average follow-up of 1.44 years. Screw length increased by 2.3 mm (p < 0.001). ATD decreased from 25.4 to 22.2 mm (p < 0.001). Alpha angle decreased from 68.7 to 59.8 degrees (p = 0.004). There was a trend towards an increase in HNO (p = 0.07). There was no significant change in PSA or HAS. There were three complications (two patients with retained broken guide wires, and one patient requiring screw removal for hip pain). With use of the Free Gliding SCFE Screw, there was evidence of screw expansion and femoral neck remodelling with short-term follow-up. More research is required to determine the long-term impact of these changes on hip function, and to aid in patient selection for this technology

Background. We occasionally came across cortical atrophy of femurs with cemented collarless polished triple-taper stem in a short term period. This study aimed to estimate radiographs of cemented collarless polished triple-taper stem taken 6 months after the initial operation. Methods. Between May 2009 and April 2011, 97 consecutive patients underwent primary total hip arthroplasty and hemiarthroplasty using SC-stem or C-stem implants. At the 6 month follow-up, a radiographic examination was performed on 70 patients (71 hips). 44 hips had Total Hip Arthoplasty, 35 had osteoarthritis, 5 had idiopathic osteonecrosis, 2 had other diseases and 27 hips had hemiarthroplasty for femoral neck fractures. The postoperative radiographs were used to estimate the cementing grade. Then the 6 month postoperative radiographs were analyzed for changes in stem subsidence, cortical atrophy and cortical hypertrophy. According to the system of Gruen- cortical atrophy and cortical hypertrophy were classified on the femoral side. We defined no cortical atrophy as grade 0, cortical atrophy less than 1 mm as grade 1, more than 1 mm and less than 2 mm as grade 2, more than 2 mm as grade 3. Result. A cortical atrophy adjacent to the stem was found in zone II according to Gruen on grade 0 thirty-five radiographs (49%), grade 1 twenty (28%), grade 2 eleven (16%), grade 3 five (7%). in zone III grade 0 twenty-seven (38%), grade 1 thirty (42%), grade 2 ten (14%), grade 3 four (6%), in zone V grade 0 fifty (70%), grade 1 twenty (28%), grade 2 one (1%), grade 3 zero (0%), in zone VI grade 0 forty-nine (69%), grade 1 twenty (28%), grade 2 two (3%), grade 3 zero (0%). Cortical hypertrophy was only demonstrated in zone V in one case. In all cases the stem subsidence was less than 1 mm. Cortical atrophy including grade 1 was recognized in 38% of THA, and in 52% of femoral neck fractures. In one case the slight radiolucent line of the postoperative X-ray disappeared after 6 months. Discussion. Cortical atrophy was recognized more in the femoral neck fracture group than in the THA group. And Cortical atrophy was recognized in zone 2 and zone 3 more frequently than in zone 5 and zone 6. According to the finite element analysis of SC-stem more stress is received on the medial aspect of the stem during weight bearing, so it is suspected that more cortical atrophy on the lateral aspect is associated with stem design. This is compatible with the cortical hypertrophy reported with Exeter stem in zone 5. Conclusion. Cortical atrophy, including minor degree atrophy, occurred in 65% of cemented collarless polished triple-taper stem in short term periods after implantation. Cortical atrophy occurred in the lateral aspect of the stem more severely and more frequently than in the medial aspect. Cortical atrophy was also recognized in the femoral neck fracture group more more severely and more frequently than in the THA group

Background. Failed ingrowth and subsequent separation of revision acetabular components from the inferior hemi-pelvis constitutes a primary mode of failure in revision total hip arthroplasty (THA). Few studies have highlighted other techniques than multiple screws and an ischial flange or hook of cages to reinforce the ischiopubic fixation of the acetabular components, nor did any authors report the use of porous metal augments in the ischium and/or pubis to reinforce ischiopubic fixation of the acetabular cup. The aims of this study were to introduce the concept of extended ischiopubic fixation into the ischium and/or pubis during revision total hip arthroplasty [Fig. 2], and to determine the early clinical outcomes and the radiographic outcomes of hips revised with inferior extended fixation. Methods. Patients who underwent revision THA utilizing the surgical technique of extended ischiopubic fixation with porous metal augments secured in the ischium and/or pubis in a single institution from 2014 to 2016 were reviewed. 16 patients were included based on the criteria of minimum 24 months clinical and radiographic follow-up. No patients were lost to follow-up. The median duration of follow-up for the overall population was 37.43 months. The patients' clinical results were assessed using the Harris Hip Score (HHS), Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index and Short form (SF)-12 score and satisfaction level based on a scale with five levels at each office visit. All inpatient and outpatient records were examined for complications, including infection, intraoperative fracture, dislocation, postoperative nerve palsy, hematoma, wound complication and/or any subsequent reoperation(s). The vertical and horizontal distances of the center of rotation to the anatomic femoral head and the inclination and anteversion angle of the cup were measured on the preoperative and postoperative radiographs. All the postoperative plain radiographs were reviewed to assess the stability of the components. Results. At the most recent follow-up, 11 (68.8%) patients rated their satisfaction level as “very satisfied” and 4 (25.0%) were “satisfied.” The median HHS improved significantly and the WOMAC global score decreased significantly at the latest follow-up (? 0.001). No intraoperative or postoperative complications were identified. All constructs were considered to have obtained bone ingrowth fixation. The median vertical distance between the latest postoperative center of rotation to the anatomic center of the femoral head improved from 14.7±10.05 mm preoperatively to 6.77±9.14 mm at final follow-up (p=0.002). The median horizontal distance between the latest postoperative center of rotation to the anatomic center of femoral head improved from 6.3±12.07 mm laterally preoperatively to 2.18±6.98 mm medially at the most recent follow-up (p=0.013) postoperatively. The median acetabular cup abduction angle improved from 55.04°±10.11° preoperatively to 44.43°± 5.73° at the most recent follow-up postoperatively (p=0.001). However, there was no difference in the median cup anteversion angles preoperatively (9.15°±5.36°) to postoperatively (9.66°±3.97°) (P=0.535). Conclusions. Early follow-up of patients reconstructed with the technique of extended ischiopubic fixation with porous metal augments demonstrated satisfactory clinical outcomes, restoration of the center of rotation and adequate biological fixation. For any figures or tables, please contact the authors directly

The PowerPoint (2007 Version; Microsoft, Redmond, Wash) method is reported to have improved repeatability and reproducibility and is better able to detect differences in radiographs than previously established manual wear measurement methods. In this study, the PowerPoint method and the Dorr and Wan method were used to calculate the polyethylene liner wear volume. The wear volumes of retrieved polyethylene liners calculated from the 3D laser scanning method were compared with each method. This study hypothesized that the wear volume calculated by the PowerPoint method would correlate well with the wear volume measured by 3D laser scanning method. Between March 2004 and June 2009, 22 polyethylene liners from 20 patients were collected during revision Total hip arthroplasty(THA). Exclusion criteria included (1) missing an early primary postoperative radiograph or prerevision radiograph, (2) evidence of acetabular loosening or migration, (3) existence of significant mismatch between early primary postoperative radiograph and prerevision radiographs on vertical axis, and (4) liner wear-through. After applying these exclusion criteria, 17 retrieved polyethylene liners from 16 patients were included in this study. Wear volumes were calculated using the PowerPoint, the Dorr and Wan methods by 3 independent experienced observers who were unaware of the study design, and 3-dimensional (3D) laser scanning methods. Spearman correlation coefficients for wear volume results indicated strong correlations between the PowerPoint and 3D laser scanning methods (range, 0.89–0.93). On the other hand, Spearman correlation analysis revealed only moderate correlations between the Dorr and Wan and 3D laser scanning methods (range, 0.67–0.77). The PowerPoint method is an efficient tool for the sequential radiologic follow-up of patients after THA. The PowerPoint method can be used to monitor linear wear after THA and could serve as an alternative method when computerized methods are not available

INTRODUCTION. Acetabular cup malpositioning has been implicated in instability and wear-related complications after total hip arthroplasty. Although computer navigation and robotic assistance have been shown to improve the precision of implant placement, most surgeons use mechanical and visual guides to place acetabular components. Authors have shown that, when using a bean bag positioner, mechanical guides are misleading as they are unable to account for the variability in pelvic orientation during positioning and surgery. However, more rigid patient positioning devices may allow for more accurate free hand cup placement. To our knowledge, no study has assessed the ability of rigid devices to afford surgeons with ideal pelvic positioning throughout surgery. The purpose of this study is to utilize robotic-arm assisted computer navigation to assess the reliability of pelvic position in total hip arthroplasty performed on patients positioned with rigid positioning devices. METHODS. 100 hips (94 patients) prospectively underwent total hip Makoplasty in the lateral decubitus position from the posterior approach; 77 stabilized by universal lateral positioner, and 23 by peg board. After dislocation but prior to reaming, one fellowship trained arthroplasty surgeon manually placed the robotic arm parallel to both the longitudinal axis of the patient and the horizontal surface of the operating table, which, if the pelvis were oriented perfectly, would represent 0 degrees of anteversion and 0 degrees of inclination. The CT-templated computer software then generated true values of this perceived zero degrees of anteversion and inclination based on the position of the robot arm registered to a preoperative pelvic CT. Therefore, variations in pelvic positioning are represented by these robotic navigation generated values. To assure the accuracy of robotic measurements, cup anteversion and inclination at times of impaction were recorded and compared to those calculated via the trigonometric ellipse method of Lewinnek on standardized 3 months postoperative X-rays. RESULTS. Mean alteration in anteversion and inclination values were 1.7 degrees (absolute value 5.3 degrees, range −20 – 20 degrees) and 1.6 degrees (absolute value 2.6 degrees, range −8 – 10 degrees) respectively. 22% of anteversion values were altered by >10 degrees; 41% by > 5 degrees. There was no difference between positioners (p=0.36) and regression analysis revealed that anteversion differences were correlated with BMI (p=0.02). Robotic navigation acetabular cup anteversion (mean 21.8 degrees) was not different from postoperative X-ray anteversion (mean 21.9 degrees)(p=0.50), nor was robotic navigation acetabular cup inclination (mean 40.6 degrees) different from postoperative X-ray inclination (mean 40.5 degrees)(p=0.34). DISCUSSION AND CONCLUSION. Rigid pelvic positioning devices present 5 to 20 degrees of variability in acetabular cup orientation, particularly with regards to anteversion. Compounding this with 20 degree safe zones and prior author demonstrations that human error is prone to 10 degrees of anteversion inaccuracy in a fixed pelvis model, there is a clear need to pay particular attention to anatomic landmarks or computer assisted techniques to assure accurate acetabular cup positioning. Patient positioning by itself should not be trusted

Introduction. Navigation in total hip arthroplasty (THA) has the goal to improve accuracy of cup orientation. Measurement of cup orientation on conventional pelvic radiographs is susceptible to error due to pelvic malpositioning during acquisition. A recently developed and validated software using a postoperative radiograph in combination with statistical shape modelling allows calculation of exact 3-dimensional cup orientation independent of pelvic malpositioning. Objectives. We asked (1) what is the accuracy of computer-navigated cup orientation (inclination and anteversion) and (2) what is the percentage of outliers (>10° difference to aimed inclination and anteversion) using postoperative measurement of 3-dimensional cup orientation. Methods. We performed a retrospective comparative study including a single surgeon series with 114 THAs (109 patients). Surgery was performed through the anterolateral approach with the patient in supine position. An image-free navigation system (PiGalileo, Smith & Nephew) with a passive digital reference base for the pelvic wing and one for the distal femur was used. The anterior pelvic plane (APP) was registered manually using a pointer and used as anatomical reference. After implantation of the press-fit cup (EP-Fit plus, Smith & Nephew) the final cup orientation (inclination and anteversion) was registered with the navigation system. Postoperative orientation was calculated using validated software to calculate 3-dimensional cup orientation. The postoperative anteroposterior pelvic radiograph in combination with a statistical model of the pelvis allowed calculation of inclination and anteversion referenced to the APP. The software was previously validated using CT measurements and revealed a mean accuracy of 0.4° for inclination 0.6° for anteversion with a maximum error of 3.3° and 3.6°, respectively. The mean postoperative inclination in the current series was 46° ± 4° (range, 35° – 60°) and the mean anteversion was 23° ± 6° (range, 11° – 37°). Accuracy was calculated as the absolute difference of the intraoperative registered cup orientation and the postoperative calculated orientation. An outlier was defined if cup orientation was outside a range of ±10° of inclination and/or anteversion. Results. (1) The mean accuracy for inclination was 3 ± 3° (0 – 17°) and 6 ± 5° (0 – 22°) for anteversion. (2) Three out of 114 cups (3%) were outliers for inclination. An increased percentage of outliers was found for anteversion with 23 out of 114 cups (20%; p<0.001). In total, 25 cups (22%) were outliers (See Figure 1). Conclusions. Previous studies evaluating accuracy of cup orientation were limited in numbers of hips due to the use of CT or used measurements on conventional postoperative radiographs which are prone to error due to pelvic malpositioning. Novel and validated software allows accurate and anatomically referenced measurement of postoperative cup orientation. This study is the single largest case series with 3-dimensional measurement of cup orientation for validation of navigated THA. Computer-assisted image-free navigation of cup orientation showed a high accuracy of cup orientation with 78% within a narrow range of ±10° of inclination and anteversion. Accuracy of cup inclination was increased compared to cup anteversion. For any figures or tables, please contact authors directly (see Info & Metrics tab above).

INTRODUCTION. Proponents of the THA anterior approach have advocated for the use of dedicated surgical tables similar to those used in lower extremity fracture care that allow for traction, rotation, and angulation of the limb during surgery. Some tables require a specially-trained assistant to manipulate the table, whereas some may be manipulated by the surgeon. The purpose of this study is to compare the clinical outcomes in patients who underwent THA through an anterior approach on an assistant-controlled (AC) versus a surgeon-controlled (SC) table. METHODS. This is a retrospective study of 343 consecutive THA patients from January 2017 – October 2017. Surgical and clinical data included surgical time, LOS, presence of pain (groin, hip, or thigh pain) at latest follow-up, and revision for any reason. Immediate postoperative radiographs were compared with latest follow-up radiographs to assess for LLD, stem alignment, and stem subsidence. RESULTS. 167 (48.7%) cases were performed using the AC table, and 176 (51.3%) were performed using the SC table. Overall, surgical time was significantly greater for surgeries which utilized the self-controlled table (70.2 minutes vs. 66.1 minutes, respectively). There was a statistically significant difference between the first and last third of cases performed on the SC table (73.6 minutes vs. 68.0 minutes, respectively). There were no significant differences in any clinical or radiographic outcomes. DISCUSSION. Surgeons who routinely perform an anterior approach for THA can expect similar outcomes using an SC table as opposed to an AC table. Although surgical time with the SC table was longer by approximately four minutes, this difference is not clinically significant. In addition, surgical time with the SC table may be decreased following an initial learning curve. The SC table allows for greater surgeon control during the procedure and a significantly smaller institutional financial investment due to the reduced manpower required

Background. We occasionally come across cortical atrophy of the femur with cemented collarless polished triple-taper stem, a short time after the operation. This study aimed to estimate the radiographs of cemented collarless polished triple-taper stem taken at three, six, twelve, and twenty-four months after the initial operation. Methods. Between May 2009 and April 2011, 97 consecutive patients underwent primary total hip arthroplasty and hemiarthroplasty using a SC-stem or C-stem implant. During the 24 month follow-up, radiographic examination was performed on a total of 95 patients (98 hips). Out of those 95 patients, 52 hips had total hip arthroplasty, 45 had osteoarthritis, 5 had idiopathic osteonecrosis, there were two 2 other cases and 46 hips had hemiarthroplasty for femoral neck fractures. The cementing grade was estimated on the postoperative radiographs. The 24 month postoperative radiographs were analyzed for changes in stem subsidence, cortical atrophy and cortical hypertrophy. According to the Gruen zone, cortical atrophy and cortical hypertrophy were classified on the femoral side. We defined no cortical atrophy as grade 0, cortical atrophy less than 1 mm as grade 1, more than 1 mm and less than 2 mm as grade 2, and more than 2 mm as grade 3. We defined Grade 1 as 1 point, Grade 2 as 2 points, and Grade 3 as 3 points. The points in every zone were calculated, and the average per zone was determined. Result. The mean points of the cortical atrophy adjacent to the stem was 1.19 in THA, and 1.58 in BHA in zone II, 0.98 in THA, and 1.15 in BHA in zone III, 0.34 in THA, and 0.6 in BHA in zone V, and 0.63 in THA, and 0.93 in BHA in zone VI. Statistical significance was found between the two groups (THA and BHA). Stem subsidence slightly increased with time. During the following 2 years there was not a single case with over 1.5mm of stem subsidence. The average stem subsidence after 24 months was 0.72 in THA, and 0.78 in BHA. Cortical hypertrophy was only demonstrated in 5 cases. Discussion. Cortical atrophy was recognized more in the femoral neck fracture group than in the THA group, and cortical atrophy was recognized in zone 2 and zone 3 more frequently than in zone 5 and zone 6. According to the finite element analysis of the SC-stem, more stress is received on the medial aspect of the stem during weight bearing, so it is suspected that more cortical atrophy on the lateral aspect is associated with stem design. These findings are compatible with the cortical hypertrophy reported with Exeter stem in zone 5. Conclusion. Cortical atrophy (cancellizaton) was recognized in 70% of THA group, and in 80% of BHA group, 2 years after the operation. Cortical atrophy in most cases was recognized in Gruen Zones 2 & 3 (P<0.01). Cortical atrophy was found more severely and more frequently in the femoral neck fracture group than the THA group (P<0.01)

Aims. The incidence of thigh pain with the short stem varies widely across different studies. We aimed to evaluate the incidence and characteristics of post-operative thigh pain after using a particular bladed short stem and its potential risk factors. Patients and Methods. We respectively reviewed 199 consecutive patients who underwent unilateral total hip replacement using the Tri-lock stem from 2013–2016, of which 168 patients were successfully followed up with minimum two year clinical follow-up. All information about thigh pain and pre- and postoperative HHS score were gathered and all preoperative and immediate postoperative radiographs were available for review. Any complications were recorded. Results. Of the 168 patients, 34 (20.2%) patients reported thigh pain at a mean 3.1 years after surgery. Of these, 2 (5.9%) reported severe pain (NRS 5 or more). The pain was persistent (from surgery to final follow-up) in 13 patients (38.2%) and subsided within 2 years in 10 cases (29.4%). The most common site of pain was the lateral thigh (70.6%). The HHS improved from a mean 54.2 points preoperatively to 79.8 postoperatively. In 123 cases with radiographs at more than 2 years follow-up, all femoral stems were well-fixed and no revision surgery was needed at the latest. BMI and CFI were found to be independent risk factors for thigh pain after using this particular stem component. Conclusions. The incidence of thigh pain in Chinese THA patients with a bladed short stem component design is as high as 20%. Among them, nearly 40% will have some disruption in sleep or daily life. More than one-third of the cases of thigh pain were persistent. A larger BMI and patients with a funnel-type morphology of the femoral canal are independent risk factors for thigh pain in the setting of this particular stem component

The use of endoprosthesis implants is frequent for tumours involving the proximal third of the femur and not amenable to primary arthroplasty or internal fixation. In this population, these implants are preferentially cemented given poor bone quality associated with systemic diseases and treatments. Loosening is a common complication of these implants that have been linked to poor bone quality, type of implants and importantly cementing technique. Thus, these techniques vary between different surgeons and based mainly on previous experience. One of the most successful cementing techniques in the arthroplasty literature is the French paradox. This technique involves removing the cancellous bone of the proximal femoral metaphysis and selects the largest stem to tightly fit the created cavity delineated by cortical bone. Cementing the implant results in a very thin cement layer that fills the inconsistent gaps between the metal and the bone. To our knowledge, no previous report exists in the literature assessing loosening in proximal femur replacement using the French paradox cementing technique. In this study, we sought to examine (1) rates of loosening in proximal femur replacement, and (2) the oncological outcomes including tumour recurrence and implant related complications. A retrospective study of 42 patients underwent proximal femur replacement between 1990 and 2018 at our institution. Of these, 30 patients met our inclusion criteria. Two independent reviewers have evaluated the preoperative and the most recent postoperative radiographs using the International Society of Limb Salvage (ISOLS) radiographic scoring system and Gruen classification for femoral stem loosening. Additionally, the acetabulum was evaluated for erosion according to the criteria of Baker et al. The mean age of this cohort was 60.5 (19–80), with 60% being males. The primary origin was metastatic in 17 (56.7%) patients, bone sarcoma in 10 (33.3%) patients and soft tissue sarcoma in 3 (10%) patients. Pathological fractures were present in 11 (36.7%) patients. Seven (23.3%) patients had prior intramedullary nailing. Preoperative radiotherapy was used in 8 (26.7%) and postoperative radiotherapy in 17 (56.7%) patients. The mean clinical follow-up was 25.2±26.3 months and the mean radiographical follow-up was 24.8±26 months. The mean ISOLS score for both reviewers was found to be 89±6.5% and 86.5±6.1%, respectively. Additionally, the first reviewer found two patients to be possibly loos (6.7%) compared to one (3.3%) patient for the second reviewer. No components scored as probably or definitely loose and non-required revision for either loosening or metal failure. Furthermore, both reviewers showed no acetabular erosion in 25 (83.3%) and 24 (80%) patients, respectively. On the other hand, the overall rate of complications was 36.6% with 11 complications reported in 30 patients. Local recurrence occurred in five (16.6%) patients. Prosthetic Dislocation was the most frequent complications with eight dislocations in four patients. Despite complications, our results showed no radiographic evidence of stem loosening. Cementing proximal femur prosthesis with a tight canal fit and with a thin cement mantle appears to be a viable option at short and medium term

Objective. While the short-stem design is not a new concept, interest has risen with increasing utilization of less invasive techniques. Especially, short stems are easier to insert through the direct anterior approach. In the radiographic evaluation of patients who underwent primary uncemented total hip arthroplasty (THA) using a TaperLoc Microplasty femoral component (Biomet, Warsaw, IN, USA), cortical hypertrophy was occasionally detected on three-month postoperative radiographs. The purpose of this study was to evaluate the radiographic changes associated with cortical hypertrophy of the femur three months postoperatively. Methods. Between May 2010 and September 2014, 645 hips in 519 patients who received the TaperLoc Microplasty stem were evaluated. Six hips in four patients were lost to follow-up. Finally, 639 hips in 515 patients were included in this study; 248 hips underwent bilateral simultaneous THA and 391 hips underwent unilateral THA. There were 103 males and 412 females (average age, 63 ± 10.1 years; average height, 156 ± 8.13 cm; and average weight, 58 ± 12.2 kg). The postoperative radiographs immediately taken after the operation and three months postoperatively were compared. We evaluated cortical hypertrophy around the stem. Cortical hypertrophy >2 mm on anterior-posterior X-ray was defined as “excessive periosteal reaction” (Figure 1). Results. Twenty-four (3.76%) of the 639 hips had an excessive periosteal reaction. Eight (1.25%) hips underwent bilateral simultaneous THA and sixteen (2.5%) hips underwent unilateral THA. With regard to the prevalence of the excessive periosteal reaction, there were no significant differences between the patients who underwent the unilateral procedure compared with those who underwent the bilateral procedure. Of these 24hips, 12 (50%) showed thigh pain in patients after surgery. The patients with an excessive periosteal reaction had an average age of 66 ± 9.02 years, an average height of 157 ± 6.4 cm, and an average weight of 61 ± 10.3 kg. There were no significant differences in age, height, and weight between the patients with an excessive periosteal reaction and all study patients. The thigh pain resolved spontaneously within three months after surgery in all patients, and no patient required revision surgery. Six (0.94%) hips had femoral periprosthetic fractures in the early postoperative period. Conclusions. Excessive periosteal reaction, which was defined as cortical hypertrophy >2 mm on anterior-posterior X-ray three month postoperatively, occurred in 3.75% of the patients who received the TaperLoc Microplasty stem. Thigh pain occurred in half of the patients who had an excessive periosteal reaction. We speculated that this reaction was caused by the concentration of the torque or vertical load on the limited area of the femur in the early postoperative period. This stress was accompanied by femoral periprosthetic fractures in the early postoperative period, and patients without femoral periprosthetic fractures experienced an excessive periosteal reaction with thigh pain

Recent innovations in total ankle replacement (TAR) have led to improvements in implant survivorship, accuracy of component positioning and sizing, and patient outcomes. CT-generated pre-operative plans and cutting guides show promising results in terms of placement enhancement and reproducibility in clinical studies. The purpose of this study was to determine the accuracy of 1) implant sizes used and 2) alignment corrections obtained intraoperatively using the cutting guides provided, compared to what was predicted in the CT generated pre-operative plans. This is a retrospective study looking at 36 patients who underwent total ankle arthroplasty using a CT generated pre-operative planning system between July 2015 and December 2017. Personalized pre-operative planning data was obtained from the implant company. Two evaluators took measurements of the angle corrected using pre- and post-operative weight bearing ankle AP X-rays. All patients had a minimum three-month follow-up with weightbearing postoperative radiographs. The actual correction calculated from the radiographic assessment was compared with the predicted angles obtained from pre-operative plans. The predicted and predicted alternative component sizes and actual sizes used were also compared. If either a predicted or predicted alternative size was implanted, we considered it to be accurate. Average age for all patients was 64 years (range 40–83), with a body mass index of 28.2 ± 5.6. All surgeries were performed by two foot and ankle surgeons. The average total surgical time was 110 ± 23 minutes. Pre-operative alignment ranged from 36.7 degrees valgus to 20 degrees varus. Average predicted coronal alignment correction was 0.8 degrees varus ± 9.3 degrees (range, 18.2 degrees valgus to 29 degrees varus) and average correction obtained was 2.1 degrees valgus ± 11.1 degrees. Average post-op alignment was consistently within 5 degrees of neutral. There were no significant differences between the predicted alignments and the postoperative weightbearing alignments. The predicted tibia implant size was accurate in all cases. The predicted sizes were less accurate for talar implants and predicted the actual talar implant size used in 66% of cases. In all cases of predicted talar size mismatch, surgical plans predicted 1 implant size larger than used. Preliminary analyses of our data is comparable to previous studies looking at similar outcomes. However, our study had higher pre-operative deformities. Despite that, post-op alignments were consistently within 5 degress of neutral with no significant difference between the predicted and actual corrections. Tibial implant sizes are highly accurate while talar implant sizes had a trend of being one size smaller than predicted. Moreover, this effect seems to be more pronounced in the earlier cases likely reflective of increasing surgeon comfort with the implant with each subsequent case. These results confirm that pre-operative cutting guides are indeed helpful in intra-operative implant selection and positioning, however, there is still some room for innovation

Acetabular cup positioning remains a real challenge and component malpositioning after total hip arthroplasty (THA) can lead to increased rates of dislocation and wear. It is a common cause for revision THA. A novel 3D imageless mini-optical navigation system was used during THA to provide accurate, intraoperative, real-time, and non-fluoroscopic data including component positioning to the surgeon. This retrospective comparative single surgeon and single approach study examined acetabular component positioning between traditional mini-posterolateral THA and mini-posterolateral THA using the 3D mini-optical navigation system. A retrospective chart review was conducted of 157 consecutive (78 3D mini-optical navigation and 79 traditional non-navigation methods) THAs performed by the senior author using a mini-posterolateral approach at an ambulatory surgery center and hospital setting. Two independent reviewers analyzed postoperative radiographs in a standardized fashion to measure acetabular component positioning. Demographic, clinical, surgical, and radiographic data were analyzed. These groups were found to have no statistical difference in age, gender, and BMI (Table I). There was no difference between groups in acetabular components in the Lewinnek safe zone, 31.2% vs 26.6% (p = 0.53). Cup anteversion within the safe zone did not differ, 35.1% vs 40.5% (p = 0.48); while cup inclination within the safe zone differed, with more in the navigation group, 77.9% vs 51.9% (p < 0.01). Change in leg length was significantly different with the navigation group's leg length at 1.9 ± 6.3, less than the traditional at 5.4 ± 7.0 (p < 0.01). There was no difference in mean change in offset between groups (4.5 ± 5.9 vs 6.2 ± 7.9, p = 0.12); navigation, traditional) (Table II). The 3D mini-optical navigation group did have significantly longer operative time (98.4 ± 17.5 vs 89.3 ± 15.5 p < 0.01). Use of the novel 3D Mini-optical Navigation System significantly improved cup inclination compared to traditional methods while increasing operative time. For any figures or tables, please contact the authors directly

Introduction. The aim of this study was to see if the evaluation of the initial postoperative radiograph following primary knee and hip arthroplasty correlated with clinical outcome at five years postoperatively. Methodology. Using our institution database we identified forty-nine hip replacements and fifty-two knee replacements performed between 2000 and 2006. All the patients underwent postoperative radiographs one day after surgery and clinical evaluation up to at least five years postoperatively. A consultant radiologist evaluated the radiographs for alignment and component position. The hip arthroplasty patients were assessed clinically using the Harris hip score, Oxford hip score, and the Western Ontario and McMaster Universities Osteoarthritis index (WOMAC). The knee arthroplasty patients were assessed using the Knee Society score, Oxford knee score, and the WOMAC score. Results. In the hip group a significant positive linear relationship was found between the superior measurement for location of the centre of rotation of hip relative to teardrop and the Oxford hip score at 5 years, as well as the WOMAC hip score, and between cup inclination and the WOMAC Hip score at a minimum of five years follow-up. The acetabular cup inclination was found to be significantly related to functional outcome as measured by the WOMAC hip score at a minimum of five years follow-up with unadjusted regression analysis. In the knee group there was no significant relationship found between radiographic findings and functional outcome as measured by the Knee Society score and Oxford knee score. Correlation analysis revealed a significant negative relationship between anteroposterior tibial lucency and functional outcome as measured by the WOMAC knee score at a minimum of five years follow-up. Conclusion. Further studies would be required with a larger sample size to evaluate possible relationships identified by this study, to develop an assessment tool to predict outcomes of arthroplasty procedures

Purpose. Anterior column screw fixation has been a useful tool in the management of acetabular fractures, either alone or in combination with other fixation techniques. Percutaneous insertion may be advantageous by limiting surgical dissection but little has been reported on its safety. The purpose of this study is to report on the efficacy and safety of percutaneous anterior column stabilization. Method. In a consecutive series of 122 operatively treated acetabular fractures, 56 patients were treated with antegrade percutaneous anterior column stabilization either alone or in combination with other fixation techniques by a single surgeon (JY). The technique was selected when the anterior column portion of the fracture was undisplaced or could be reduced via indirect methods. Intraoperative fluoroscopy was used to guide the placement of either a 6.5 mm or 7.3 mm cannulated antegrade anterior column lag screw. Postoperative radiographs (anteroposterior and Judet views) were obtained in the recovery room, prior to discharge and at clinic follow up. Results. The mean age of patients in the series was 52 years (range 17 91). Mean follow up was 13 months. There was one death from associated injuries. Based on the classification system described by Letournel, there were 22 anterior column, 8 transverse, 11 transverse / posterior wall, 9 anterior column / posterior hemitransverse, 1 associated both column and 5 T-type fractures. There were no vascular, neurologic, or urologic complications in the series. There were no cases of intraarticular screw placement. In two cases, the screw did not completely cross the entire fracture line on postoperative radiographs. There were no cases of hardware failure or loss of reduction. There were two cases of hardware removal for hardware prominence. There was one case of chronic proximal femur osteomyelitis, and two cases requiring subsequent total hip arthroplasty for associated injuries. All fractures healed. Conclusion. This study supports percutaneous anterior column stabilization as a safe and effective technique in the treatment of selected acetabular fractures

Background. Under- or oversizing of either component of a total knee implant can lead to early component loosening, instability, soft tissue irritation or overstuffing of joint gaps. All of these complications may cause postoperative persistent pain or stiffness. While survival of primary TKA's is excellent, recent studies show that patient satisfaction is worse. Up to 20% of the patients are not satisfied with the outcome as and residual pain is still a frequent occurrence. The goal of this study was therefore to evaluate if the sizing of the femoral component, as measured on a 3D-reconstructed projection, is related to patient reported outcome measures. From our prospectively collected TKA outcome database, all patients with a preoperative CT and a postoperative X-ray of their operated knee were included in this study. Of these 43 patients, 26 (60,5%) were women and 17 (39,5%) were men. The mean age (+/−SD) was 74,6 +/− 9 years. Methods. CT scans were acquired. All patients underwent TKA surgery in a single institution by one surgical team using the same bi- cruciate substituting total knee (Journey II BCS, Smith&Nephew, Memphis, USA). Using a recently released X-ray module in Mimics (Materialise NV, Leuven, Belgium), this module allows to align the post-operative bi-planar x-rays with the 3D- reconstructed pre-operative distal femur and to determine the 3D position of the bone and implant models using the CAD- file of the implant. This new technique was validated at our department and was found to have a sub-degree, sub-millimeter accuracy. Eleven zones of interest were defined. On the medial and the lateral condyle, the extension, mid-flexion and deep flexion facet were determined. Corresponding trochlear zones were defined and two zones were defined to evaluate the mediolateral width. In order to compare different sizes, elastic deforming mesh matching algorithms were implemented to transfer the selected surfaces from one implant to another. The orthogonal distances from the implant to the nearest bone were calculated. Positive values represent a protruding (oversized) femoral component, negative values an undersized femoral component. The figure shows the marked zones on the femoral implant. The KOOS subscores and KSS Satisfaction subscore were evaluated. Results. Two-step cluster analysis based on the clinically relevant zones on both medial (zone 12, 14 and 17) and lateral (zone 2, 5 and 9) femoral condyle of the implant, led to the formation of two clusters. Cluster 1 contained 23 patients with, in general, an undersized femoral component (negative values) whilst cluster 2 contained 20 patients with in general an oversized femoral component (positive values). (see graph) No significant differences were found between both clusters regarding demographics. Regarding PROM data, a significant difference was found for KOOS Symptoms (p=0.037) and a KOOS Pain (p=0.05). Other PROMs are not significantly different between both clusters. Conclusion. Our data shows that undersizing the femoral component results in less postoperative pain and symptoms. The clinical consequence of this study is that in case of in between femoral component sizes, the smallest size should be chosen to diminish the occurrence of postoperative pain and symptoms