Aims

The liner design is a key determinant of the constraint of a reverse total shoulder arthroplasty (rTSA). The aim of this study was to compare the degree of constraint of rTSA liners between different implant systems.

Aims. This study compared patient-reported outcomes of three total knee arthroplasty (TKA) designs from one manufacturer: one cruciate-retaining (CR) design, and two cruciate-sacrificing designs, anterior-stabilized (AS) and posterior-stabilized (PS). Methods. Patients scheduled for primary TKA were included in a single-centre, prospective, three-armed, blinded randomized trial (n = 216; 72 per group). After intraoperative confirmation of posterior cruciate ligament (PCL) integrity, patients were randomly allocated to receive a CR, AS, or PS design from the same TKA system. Insertion of an AS or PS design required PCL resection. The primary outcome was the mean score of all five subscales of the Knee injury and Osteoarthritis Outcome Score (KOOS) at two-year follow-up. Secondary outcomes included all KOOS subscales, Oxford Knee Score, EuroQol five-dimension health questionnaire, EuroQol visual analogue scale, range of motion (ROM), and willingness to undergo the operation again. Patient satisfaction was also assessed. Results. Patients reported similar levels of pain, function, satisfaction, and general health regardless of the prosthetic design they received. Mean maximal flexion (129° (95% confidence interval (CI) 127° to 131°) was greater in the PS group than in the CR (120° (95% CI 121° to 124°)) and AS groups (122° (95% CI 120° to 124°)). Conclusion. Despite differences in design and constraint, CR, AS, and PS designs from a single TKA system resulted in no differences in patient-reported outcomes at two-year follow-up. PS patients had statistically better ROM, but the clinical significance of this finding is unclear. Cite this article: Bone Joint J 2023;105-B(12):1271–1278

Aims

Glenoid bone loss is a significant problem in the management of shoulder instability. The threshold at which the bone loss is considered “critical” requiring bony reconstruction has steadily dropped and is now approximately 15%. This necessitates accurate measurement in order that the correct operation is performed. CT scanning is the most commonly used modality and there are a number of techniques described to measure the bone loss however few have been validated. The aim of this study was to assess the accuracy of the most commonly used techniques for measuring glenoid bone loss on CT.

Aims

The aim of this study was to report the long-term prognosis of patients with multiple Langerhans cell histiocytosis (LCH) involving the spine, and to analyze the risk factors for progression-free survival (PFS).

Tumours of the sacrum are difficult to manage. The sacrum provides the structural connection between the torso and lower half of the body and is subject to both axial and rotational forces. Thus, tumours or their treatment can compromise the stability of the spinopelvic junction. Additionally, nerves responsible for lower limb motor groups as well as bowel, bladder, and sexual function traverse or abut the sacrum. Preservation or sacrifice of these nerves in the treatment of sacral tumours has profound implications on the function and quality of life of the patient. This annotation will discuss current treatment protocols for sacral tumours.

Cite this article: Bone Joint J 2022;104-B(12):1284–1291.

Introduction and Objective. Trochanteric fractures are associated with increasing incidence and represent serious adverse effect of osteoporosis. Their cephalomedullary nailing in poor bone stock can be challenging and associated with insufficient implant fixation in the femoral head. Despite ongoing implant improvements, the rate of mechanical complications in the treatment of unstable trochanteric fractures is high. Recently, two novel concepts for nailing with use of a helical blade – with or without bone cement augmentation – or an interlocking screw have demonstrated advantages as compared with single screw systems regarding rotational stability and cut-out resistance. However, these two concepts have not been subjected to direct biomechanical comparison so far. The aims of this study were to investigate in a human cadaveric model with low bone density (1) the biomechanical competence of cephalomedullary nailing with use of a helical blade versus an interlocking screw, and (2) the effect of cement augmentation on the fixation strength of the helical blade. Materials and Methods. Twelve osteoporotic and osteopenic femoral pairs were assigned for pairwise implantation using either short TFN-ADVANCED Proximal Femoral Nailing System (TFNA) with a helical blade head element, offering the option for cement augmentation, or short TRIGEN INTERTAN Intertrochanteric Antegrade Nail (InterTAN) with an interlocking screw. Six osteoporotic femora, implanted with TFNA, were augmented with 3 ml cement. Four study groups were created – group 1 (TFNA) paired with group 2 (InterTAN), and group 3 (TFNA augmented) paired with group 4 (InterTAN). An unstable pertrochanteric OTA/AO 31-A2.2 fracture was simulated. All specimens were biomechanically tested until failure under progressively increasing cyclic loading featuring physiologic loading trajectory, with monitoring via motion tracking. Results. T-score in groups 3 and 4 was significantly lower compared with groups 1 and 2, p=0.03. Stiffness (N/mm) in groups 1 to 4 was 335.7+/−65.3, 326.9+/−62.2, 371.5+/−63.8 and 301.6+/−85.9, being significantly different between groups 3 and 4, p=0.03. Varus (°) and femoral head rotation around neck axis (°) after 10,000 cycles were 1.9+/−0.9 and 0.3+/−0.2 in group 1, 2.2+/−0.7 and 0.7+/−0.4 in group 2, 1.5+/−1.3 and 0.3+/−0.2 in group 3, and 3.5+/−2.8 and 0.9+/−0.6 in group 4, both with significant difference between groups 3 and 4, p<=0.04. Cycles to failure and failure load (N) at 5° varus in groups 1 to 4 were 21428+/−6020 and 1571.4+/−301.0, 20611+/−7453 and 1530.6+/−372.7,21739+/−4248 and 1587.0+/−212.4, and 18622+/−6733 and 1431.1+/−336.7, both significantly different between groups 3 and 4, p=0.04. Conclusions. From a biomechanical perspective, cephalomedullary nailing of trochanteric fractures with use of helical blades is comparable to interlocking screw fixation in femoral head fragments with low bone density. Moreover, bone cement augmentation of helical blades considerably improves their fixation strength in poor bone quality

Aims

The purpose of our study was to determine which groups of orthopaedic providers favour virtual care, and analyze overall orthopaedic provider perceptions of virtual care. We hypothesize that providers with less clinical experience will favour virtual care, and that orthopaedic providers overall will show increased preference for virtual care during the COVID-19 pandemic and decreased preference during non-pandemic circumstances.

Aims

Up to one in five patients undergoing primary total hip (THA) and knee arthroplasty (TKA) require contralateral surgery. This is frequently performed as a staged procedure. This study aimed to determine if outcomes, as determined by the Oxford Hip Score (OHS) and Knee Score (OKS) differed following second-side surgery.

Abstract. Introduction. Long term survivorship in Total Knee Arthroplasty is significantly dependent on prosthesis alignment. The aim of this study was to determine, compare and analyse the coronal alignment of the tibial component of a single implant system using 3 different techniques. Method. Retrospective study of cases from a prospectively collected database. Radiological assessment included measurement of the coronal alignment of tibial components of total knee arthroplasties, and its deviation from the mechanical axis. A comparison study of intramedullary, extramedullary and tibial crest alignment methods was performed. Results. 66 consecutive patients (3 groups of 22 each). Mean BMI was 26. The mean angle of deviation from the mechanical axis was significantly lesser (p< 0.05) in the Tibial crest alignment group patients compared to the other 2 groups. Moreover, the number of outliers (+/-3 degrees) were 2 and 4 in the intra and extramedullary group, whereas there were none in the tibial crest group. The inter and intraclass correlation coefficient was 0.8 and 0.9 respectively. Conclusion. The Tibial Crest Alignment Technique is an effective technique to produce consistent results to achieve optimal coronal alignment of the tibial component in TKA, even in patients with high BMI. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Aims

Echocardiography is commonly used in hip fracture patients to evaluate perioperative cardiac risk. However, echocardiography that delays surgical repair may be harmful. The objective of this study was to compare surgical wait times, mortality, length of stay (LOS), and healthcare costs for similar hip fracture patients evaluated with and without preoperative echocardiograms.

Aims

The direct anterior (DA) approach has been associated with rapid patient recovery after total hip arthroplasty (THA) but may be associated with more frequent femoral complications including implant loosening. The objective of this study was to determine whether the addition of a collar to the femoral stem affects implant migration, patient activity, and patient function following primary THA using the DA approach.

Aims

This study explores the reported rate of surgical site infection (SSI) after hip fracture surgery in published studies concerning patients treated in the UK.

The purpose of this study was to examine the influence of weight-bearing on the measurement of in vivo wear of total knee replacements using model-based RSA at 1 and 2 years following surgery. Model-based RSA radiographs were collected for 106 patients who underwent primary TKR at a single institution. Supine RSA radiographs were obtained post-operatively and at 6-, 12-, and 24-months. Standing (weight-bearing) RSA radiographs were obtained at 12-months (n=45) and 24-months (n=48). All patients received the same knee design with a fixed, conventional PE insert of either a cruciate retaining or posterior stabilized design. Ethics approval for this study was obtained. In order to assess in vivo wear, a highly accurate 3-dimensional virtual model of each in vivo TKA was developed. Coordinate data from RSA radiographs (mbRSA v3.41, RSACore) were applied to digital implant models to reconstruct each patient's replaced knee joint in a virtual environment (Geomagic Studio, 3D Systems). Wear was assessed volumetrically (digital model overlap) on medial and lateral condyles separately, across each follow-up. Annual rate of wear was calculated for each patient as the slope of the linear best fit between wear and time-point. The influence of weight-bearing was assessed as the difference in annual wear rate between standing and supine exams. Age, BMI, and Oxford-12 knee improvement were measured against wear rates to determine correlations. Weight bearing wear measurement was most consistent and prevalent in the medial condyle with 35% negative wear rates for the lateral condyle. For the medial condyle, standing exams revealed higher mean wear rates at 1 and 2 years, supine, 16.3 mm3/yr (SD: 27.8) and 11.2 mm3/yr (SD: 18.5) versus standing, 51.3 mm3/yr (SD: 55.9) and 32.7 mm3/yr (SD: 31.7). The addition of weight-bearing increased the measured volume of wear for 78% of patients at 1 year (Avg: 32.4 mm3/yr) and 71% of patients at 2 years (Avg: 48.9 mm3/yr). There were no significant (95% CI) correlations between patient demographics and wear rates. Volumetric, weight-bearing wear measurement of TKR using model-based RSA determined an average of 33 mm3/yr at 2 years post-surgery for a modern, non-cross-linked polyethylene bearing. This value is comparable to wear rates obtained from retrieved TKRs. Weight-bearing exams produced better wear data with fewer negative wear rates and reduced variance. Limitations of this study include: supine patient imaging performed at post-op, no knee flexion performed, unknown patient activity level, and inability to distinguish wear from plastic creep or deformation under load. Strengths of this study include: large sample size of a single TKR system, linear regression of wear measurements and no requirement for implanted RSA beads with this method. Based on these results, in vivo volumetric wear of total knee replacement polyethylene can be reliably measured using model-based RSA and weight-bearing examinations in the short- to mid–term. Further work is needed to validate the accuracy of the measurements in vivo

Aims

Thresholds for operative eligibility based on body mass index (BMI) alone may restrict patient access to the benefits of arthroplasty. The purpose of this study was to evaluate the relationship between BMI and improvements in patient-reported outcome measures (PROMs), and to determine how many patients would have been denied improvements in PROMs if BMI cut-offs were to be implemented.

Purpose. The purpose of this study was to examine the influence of weight-bearing on the measurement of in vivo wear of total knee replacements using model-based RSA at 1 and 2 years following surgery. Methods. Model-based RSA radiographs were collected for 106 patients who underwent primary TKR at a single institution. Supine RSA radiographs were obtained post-operatively and at 6-, 12-, and 24-months. Standing (weight-bearing) RSA radiographs were obtained at 12-months (n=45) and 24-months (n=48). All patients received the same knee design with a fixed, conventional PE insert of either a cruciate retaining or posterior stabilized design. Ethics approval for this study was obtained. In order to assess in vivo wear, a highly accurate 3-dimensional virtual model of each in vivoTKA was developed. Coordinate data from RSA radiographs (mbRSA v3.41, RSACore) were applied to digital implant models to reconstruct each patient's replaced knee joint in a virtual environment (Geomagic Studio, 3D Systems). Wear was assessed volumetrically (digital model overlap) on medial and lateral condyles separately, across each follow-up. Annual rate of wear was calculated for each patient as the slope of the linear best fit between wear and time-point. The influence of weight-bearing was assessed as the difference in annual wear rate between standing and supine exams. Age, BMI, and Oxford-12 knee improvement were measured against wear rates to determine correlations. Results. Weight bearing wear measurement was most consistent and prevalent in the medial condyle with 0–4% of calculated wear rates being negative compared to 29–39% negative wear rates for the lateral condyle. For the medial condyle, standing exams revealed higher mean wear rates at 1 and 2 years; supine, 16.3 mm. 3. /yr (SD: 27.8) and 11.2 mm. 3. /yr (SD: 18.5) versus standing, 51.3 mm. 3. /yr (SD: 55.9) and 32.7 mm. 3. /yr (SD: 31.7). The addition of weight-bearing increased the measured volume of wear for 78% of patients at 1 year (Avg: 32.4 mm. 3. /yr) and 71% of patients at 2 years (Avg: 48.9 mm. 3. /yr). There were no significant (95% CI) correlations between patient demographics and wear rates. Discussion and Conclusion. This study demonstrated TKA wear to occur at a rate of approximately 10 mm. 3. /year and 39 mm. 3. /year in patients imaged supine versus standing, respectively, averaged over 2 years of clinical follow-up. In an effort to eliminate the effect of PE creep and deformation, wear was also calculated between 12 and 24 months as 9.3 mm. 3. (standing examinations), This value is comparable to wear rates obtained from retrieved TKRs. Weight-bearing exams produced better wear data with fewer negative wear rates and reduced variance. Limitations of this study include: supine patient imaging performed at post-op, no knee flexion performed, and unknown patient activity level. Strengths of this study include: large sample size of a single TKR system, linear regression of wear measurements and no requirement for implanted RSA beads with this method. Based on these results, in vivo volumetric wear of total knee replacement polyethylene can be reliably measured using model-based RSA and weight-bearing examinations in the short- to mid–term. For any figures or tables, please contact authors directly

Background. The purpose of this study was to determine if thresholds regarding the percentage of maximal improvement in the Simple Shoulder Test (SST) and American Shoulder and Elbow Surgery (ASES) score exist that predict “excellent” patient s­atisfaction (PS) following reverse total shoulder arthroplasty (RSA). Methods. Patients undergoing RSA using a single implant system were evaluated pre-operatively and at a minimum 2-year follow-up. Receiver-operating-characteristic (ROC) curve analysis determined thresholds to predict “excellent” PS by evaluating the percentage of maximal improvement for SST and ASES. Pre-operative factors were analyzed as independent predictors for achieving SST and ASES thresholds. Results. 198 (SST) and 196 (ASES) patients met inclusion criteria. For SST and ASES, ROC analysis identified 61.3% (p<.001) and 68.2% (p<.001) maximal improvement as the threshold for maximal predictability of “excellent” satisfaction respectively. Significant positive correlation between the percentage of maximum score achieved and “excellent” PS for both groups were found (r=.440, p<.001 for SST score; r=0.417, p<.001 for ASES score). Surgery on the dominant hand, greater baseline VAS Pain, and cuff arthropathy were independent predictors for achieving the SST and ASES threshold. Conclusion. Achievement of 61.3% of maximal SST score improvement and 68.3% of maximal ASES score improvement represent thresholds for the achievement of “excellent” satisfaction following RSA. Independent predictors of achieving these thresholds were dominant sided surgery and higher baseline pain VAS scores for SST, and rotator cuff arthropathy for ASES. Keywords. Percentage of maximal improvement; Predictors; American Shoulder and Elbow Surgery Score; Simply Shoulder Test; Reverse shoulder Arthroplasty; Satisfaction. Level of Evidence. Level III

Aims

Acromial fractures following reverse shoulder arthroplasty (RSA) have a wide range of incidences in reported case series. This study evaluates their incidence following RSA by systematically reviewing the current literature.

Introduction. Contemporary total knee systems accommodate for differential sizing between femoral and tibial components to allow surgeons to control soft tissue balancing and optimize rotation. One method some manufacturers use to allow differential sizing involves maintaining coronal articular congruency with a single radius of curvature throughout sizes while clipping the medial-lateral width, called a single coronal geometry system. Registry data show a 20% higher revision rate when the tibial component is smaller than the femur (downsizing) in the DePuy PFC system, a single coronal system, possibly from increased stresses from edge loading or varying articular congruency. We examined a different single coronal geometry knee system, Smith & Nephew Genesis II, to determine if edge loading is present in downsized tibial components by measuring area and location of deviation of the polyethylene articular surface damage. Methods. 45 Genesis II posterior-stabilized polyethylene inserts (12 matched and 33 downsized tibial components) were CT scanned. 3D reconstructions were registered to corresponding pristine component reconstructions, and 3D deviation maps of the retrieved articular surfaces relative to the pristine surfaces were created. Each map was exported as a point cloud to a custom MATLAB code to calculate the area and weighted center of deviation of the articular surfaces. An iterative k-means clustering algorithm was used to isolate regions of deviation, and a shrink-wrap algorithm was applied to calculate their areas. The area of deviation was calculated as the sum of all regions of deviation and was normalized to the area of the articular surface. The location of deviation was described using the weighted center of deviation and the location of maximum deviation on the articular surfaces relative to the center of the post (Fig. 1). Pearson product moment correlations were conducted to examine the correlation between length of implantation (LOI) and the medial and lateral areas of deviation for all specimens, matched components, and downsized components. Results. The mean LOIs for downsized and matched tibial components were not different (36±28 months vs 46±26 months, p=0.24). Areas of deviation for the medial and lateral sides for both downsized and matched components increased with LOI (p<0.001). Medial and lateral sides of matched retrievals were not different in location of maximum deviation, maximum deviation, and weighted center of deviation (p>0.4). The matched and downsized retrievals did not have different centers of deviation in the medial-lateral direction, maximum deviations, or locations of maximum deviations (p>0.1). Discussion. Our results suggest that downsizing the tibial component in the Genesis II system, a single coronal geometry system, did not affect the area or location of deviation on the articular surface. Overall, the weighted center of deviation remained close to the dwell point and did not change as a function of tibial downsizing. However, we saw deviation patterns biased peripherally for inserts with low LOI in both matched and downsized cohorts. With increasing LOI, the deviation expanded to cover the majority of the available articular surface. Our results suggest the need to further examine this and other systems determine the effects of differential sizing. For figures/tables, please contact authors directly.

Introduction. The mobile-bearings were introduced in total knee arthroplasty (TKA) to improve the knee performance by simulating more closely ‘normal’ knee kinematics, and to increase the longevity of TKA by reducing the polyethylene wear and periprosthetic osteolysis. However, the superiority between posterior-stabilized mobile-bearing and fixed-bearing designs still remains controversial. The objective of the present study was to compare the mid-term results of Scorpio + Single Axis system (Stryker Howmedica Osteonics, Allendale, New Jersey) for the mobile-bearing knees and Duracon system (Stryker Howmedica Osteonics, Allendale, New Jersey) for the fixed bearing design with regard to clinical and roentgenographic outcome with special reference to any complications and survivorship. Methods. Prospective, randomized, double-blinded controlled study was carried out on 56 patients undergoing primary, unilateral total knee arthroplasty for osteoarthritis, who were divided into two groups. Group I received mobile-bearing knee prosthesis (29 patients) and Group 2 received fixed-bearing prosthesis (27 patients). The patients were assessed by a physical examination and knee scoring systems preoperatively, at a follow-up of three months, six months, and one year after surgery by independent researcher who was not part of the operating team, and was blinded as to the type of implant inserted. We used the Oxford knee score (OKS) and Knee society score (KSS), with Knee Society Knee Score (KSKS) and Knee Society Functional Score (KSFS) being the subsets. The questionnaire for OKS was printed in our national language, and handed over to the patient at each visit. Results. The Knee Society knee scores, pain scores, functional scores and Oxford knee scores were not statistically different (P > 0.05) between the two groups. Mean postoperative range-of-motion of mobile-bearing knees was significantly greater than that of fixed-bearing knees (127º versus 111º, P = 0.011). 72% of patients could sit cross legged, 48% could sit on the floor, and 17% could squat. Kaplan–Meier survival rate was 100%. No spin-out of mobile bearing was observed. The radiological analysis showed no osteolysis or implant loosening. Conclusion. Mobile-bearing, and fixed-bearing knees demonstrated no statistically significant difference in the Oxford knee score, Knee society score, and radiological outcome with 100% survivorship, at 4 to 6.5 years (mean: 5.5 years) follow up. However, the post-operative range-of-motion of mobile-bearing knees was significantly higher than the fixed-bearing designs (mean, 127° versus 111°; range, 95° to 145° versus 80° to 125°)