The December 2023 Research Roundup. 360. looks at: Tissue integration and chondroprotective potential of acetabular labral augmentation with autograft tendon: study of a porcine model; The Irish National Orthopaedic Register under cyberattack: what happened, and what were the consequences?; An overview of machine learning in orthopaedic surgery: an educational paper; Beware of the fungus…; New evidence for COVID-19 in patients undergoing joint replacement surgery

Aims

Most patients with advanced malignancy suffer bone metastases, which pose a significant challenge to orthopaedic services and burden to the health economy. This study aimed to assess adherence to the British Orthopaedic Oncology Society (BOOS)/British Orthopaedic Association (BOA) guidelines on patients with metastatic bone disease (MBD) in the UK.

Aims. Orthopaedic surgery requires grafts with sufficient mechanical strength. For this purpose, decellularized tissue is an available option that lacks the complications of autologous tissue. However, it is not widely used in orthopaedic surgeries. This study investigated clinical trials of the use of decellularized tissue grafts in orthopaedic surgery. Methods. Using the ClinicalTrials.gov (CTG) and the International Clinical Trials Registry Platform (ICTRP) databases, we comprehensively surveyed clinical trials of decellularized tissue use in orthopaedic surgeries registered before 1 September 2022. We evaluated the clinical results, tissue processing methods, and commercial availability of the identified products using academic literature databases and manufacturers’ websites. Results. We initially identified 4,402 clinical trials, 27 of which were eligible for inclusion and analysis, including nine shoulder surgery trials, eight knee surgery trials, two ankle surgery trials, two hand surgery trials, and six peripheral nerve graft trials. Nine of the trials were completed. We identified only one product that will be commercially available for use in knee surgery with significant mechanical load resistance. Peracetic acid and gamma irradiation were frequently used for sterilization. Conclusion. Despite the demand for decellularized tissue, few decellularized tissue products are currently commercially available, particularly for the knee joint. To be viable in orthopaedic surgery, decellularized tissue must exhibit biocompatibility and mechanical strength, and these requirements are challenging for the clinical application of decellularized tissue. However, the variety of available decellularized products has recently increased. Therefore, decellularized grafts may become a promising option in orthopaedic surgery. Cite this article: Bone Joint Res 2023;12(3):179–188

Introduction and Objective. The patients with a total hip arthroplasty is growing in world manly in Europe and USA, and this solution present a high success at 10years in several orthopaedic registers. The application of total press-fit hip fixation presents the most used solution, but presents some failures associated to the acetabular component fixation, associated to the load transfer and bone loss at long term. The aim of this work is to investigate the influence of different acetabular bone loss in the strain distribution in iliac bone. To evaluate implant fixation, an experimental study was performed using acetabular press-fit component simulating different acetabular bone loss and measuring the strain distribution. Materials and Methods. The experimental samples developed was based in an iliac bone model of Sawbones supplier and a acetabular component Titanium (Stryker) in a condition press-fit fixation and was implanted according surgical procedure with 45º inclination angle and 20º in the anteversion angle. Were developed five models with same initial bone, one with intact condition simulating the cartilage between bones and four with different bone loss around the acetabular component. These four models representing the evolution of bone support of acetabular components presented in the literature. The evolution of bone loss was imposed with a CAD CAM process in same iliac bone model. The models were instrumented with 5 rosettes in critical region at the cortical bone to measure the strain evolution along the process. Results. The results of strain gauges present the influence of acetabular component implantation, reducing the bone strains and presented the effect of the strain shielding. The acetabular component works as a shield in the load transfer. The critical region is the posterior region with highest principal strains and the strain effect was observed with different bone loss around acetabular component. The maximum value of principal strain was observed in the intact condition in the anterior region, with 950μ∊. In the posterior superior region, the effect of bone loss is more important presenting a reduction of 500% in the strains. The effect of bone loss is presented in the strains induced with acetabular implantation, in the first step of implantation the maximum strain was 950μ∊ and in the last model the value was 50μ∊, indicating lower press-fit fixation. Conclusions. The models developed allows study the effect of bone loss and acetabular implant fixation in the load transfer at the hip articulation. The results presented a critical region as the anterior-superior and the effect of strain shielding was observed in comparison with intact articulation. The results of press-fit fixation present a reduction of implant stability along bone loss. The process of bone fixation developed present some limitation associated to the bone adhesion in the interface, not considered. Acknowledgement. This work was supported by POCI-01-0145-FEDER-032486,– FCT, by the FEDER, with COMPETE2020 - (POCI), FCT/M

Introduction. Shoulder arthoplasty has increased in the last years and its main goal is to relieve pain and restore function. Shoulder prosthesis enters in the market without any type of pre-clinical tests. Within this paper we present study experimental and computational tests as pre-clinical testing to evaluate total shoulder arthoplasty performance. Materials and methods. An in vitro experimental simulator was designed to characterize experimentally the intact and implanted shoulder glenoid articulation. Fourth generation Sawbones® composite left humerus and scapula were used and the cartilage was replicated with silicone for the intact articulation (figure 1). In the intact experimental articulation we considered the inferior glenohumeral ligament as an elastic band with equivalent mechanical properties. For the implanted shoulder, the Comprehensive® Total Shoulder System (Biomet®) with a modular Hybrid® glenoid base and Regenerex® central post was considered (figure 2). The prostheses were implanted by an experienced surgeon and clinical results from orthopedic registers were collected. The system structures were placed to simulate 90º in abduction, including the following muscle forces: Deltoideus 300N, Infraspinatus 120N, Supraspinatus 90N and Subscapularis 225N. The finite element model was created with tetrahedral linear elements with linear elastic and isotropic material for the humerus in figure 3, (Young's modulus for cortical bone − 16.5 GPa; trabecular bone − 124 MPa). Anisotropic behavior was considered for the scapula model (E11 = 342.1 MPa, E22 = 212.8 MPa, E33 = 194.4 MPa). The shoulder prosthesis was of polyethylene with 1GPa and titanium with 110 GPa. The Poisson's ratio was 0.3 in all material, except for polyethylene where we assumed a value of 0.4. A long-term post-operative condition was simulated. Results. The experimental results were compared with numerical ones for model validation. The strains measured evidence the effect of the implant presence, manly in the scapula. In the anterior region presents an increase of strains (+26%) was observed for the anterior region and decrease (−52%) in the posterior region, suggesting strain shielding in figure 4. At the glenoid cavity, the numerical principal strains present safety values of strains (200 to 2500) µε in both axial and coronal planes. This indicates that on the long-term the glenoid prosthesis is well fixed to the surrounding bone tissue and bone integrity is maintained despite the presence of the implant. However there are some peak values (2500, 25 000 µε) that were observed in some small areas in the posterior and distal regions. Results were compared with clinical ones. Discussion and Conclusions. The proposed pre-clinical test with the articulation at 90º in abduction can predict bone behavior when total shoulder prosthesis is implanted and in the long term post-operative condition. The results obtained evidence some critical regions around the glenoid component. This pre-clinical test can be implemented to improve the concepts before market

Total shoulder arthroplasty is a well-tested procedure that offers pain relief and restores the joint function. However, failure rate is still high, and glenoid loosening is pointed as the main reason in orthopedic registers. In order to understand the principles of failure, the principal strain distributions after implantation with Comprehensive® Total Shoulder System of Biomet® were experimental and numerically studied to predict bone behavior. Fourth generation composite left humerus and scapula from Sawbones® were used. These were implanted with Comprehensive® Total Shoulder System (Biomet®) with a modular Hybrid® glenoid base and Regenerex® glenoid and placed in situ by an experienced surgeon. The structures were placed in order to simulate 90º abduction, including principal muscular actions. Muscle forces used were as follows: Deltoideus 300N, Infraspinatus 120N, Supraspinatus 90N, Subscapularis 225N. All bone structures were modeled considering cortical and the trabecular bone of the scapula. The components of prosthesis were placed in the same positions than those in the in vitro models. Geometries were meshed with tetrahedral linear elements, with material properties as follows: Elastic modulus of cortical bone equal to 16 GPa, elastic modulus of trabecular bone equal to 0.155 GPa, polyethylene equal to 1GPa and titanium equal to 110 GPa. The assumed Poisson's ratio was 0.3 in all except for polyethylene where we assumed a value of 0.4. The prosthesis was considered as glued to the adjacent bone. The finite element model was composed of 336 024 elements. At the glenoid cavity, the major influence of the strain distributions was observed at the posterior-superior region, in both cortical and trabecular bone structures. The system presents critical region around holes of fixation in glenoid component. At the trabecular bone, the maximum principal strains at the posterior-superior region ranged from 2250 µε to 3000 µε. While at the cortical bone, the maximum principal strains were 300 µε to 400 µε. The results observed evidence some critical regions of concern and the effect of implant in the bone strains mainly at the posterior-superior region of the glenoid cavity is pronounced. This indicates that this region is more affected by the implant if bone remodeling is a concern and it is due to the strain-shielding effect, which has been connected with loosening of the glenoid component

Using data from the Norwegian Hip Fracture Register, 8639 cemented and 2477 uncemented primary hemiarthroplasties for displaced fractures of the femoral neck in patients aged > 70 years were included in a prospective observational study. A total of 218 re-operations were performed after cemented and 128 after uncemented procedures. Survival of the hemiarthroplasties was calculated using the Kaplan-Meier method and hazard rate ratios (HRR) for revision were calculated using Cox regression analyses. At five years the implant survival was 97% (95% confidence interval (CI) 97 to 97) for cemented and 91% (95% CI 87 to 94) for uncemented hemiarthroplasties. Uncemented hemiarthroplasties had a 2.1 times increased risk of revision compared with cemented prostheses (95% confidence interval 1.7 to 2.6, p < 0.001). The increased risk was mainly caused by revisions for peri-prosthetic fracture (HRR = 17), aseptic loosening (HRR = 17), haematoma formation (HRR = 5.3), superficial infection (HRR = 4.6) and dislocation (HRR = 1.8). More intra-operative complications, including intra-operative death, were reported for the cemented hemiarthroplasties. However, in a time-dependent analysis, the HRR for re-operation in both groups increased as follow-up increased.

This study showed that the risk for revision was higher for uncemented than for cemented hemiarthroplasties.

With the established success of the National Joint Registry and the emergence of a range of new national initiatives for the capture of electronic data in the National Health Service, orthopaedic surgery in the United Kingdom has found itself thrust to the forefront of an information revolution. In this review we consider the benefits and threats that this revolution poses, and how orthopaedic surgeons should marshal their resources to ensure that this is a force for good.

Our aim was to ascertain the opinion of Orthopaedic Consultants, General Practitioners, and Patients on the proposed primary care based follow up of joint replacements. An email questionnaire was sent Orthopaedic Consultants registered with the BOA. Responders had to answer simple questions regarding follow up practices after hip and knee arthroplasty and safe alternatives to the existing system. General practitioners in London were sent a different questionnaire to assess their familiarity with follow up of arthroplasty patients and their competence in identifying complications. Finally, arthroplasty patients were directly questioned on their preference for follow up. Eigthy-one Orthopaedic Consultants who undertake lower limb arthroplasty responded, 89.06% advocated follow up and review of radiographs by the surgeon. The Arthroplasty Practitioner, the Radiologist and the Physiotherapist were deemed suitable for follow up of patients by 50%, 14.06% and 4.69 % respectively. All responders unanimously disagreed with initial follow up by General Practitioners (0%). However, after a 12 month review, 30.15% thought primary arthroplasty patients could be discharged to the care of their General Practitioner and 11.11% were happy to discharge revision arthroplasty patients. Of the 52 General Practitioners who returned our questionnaire, only 37% were confident of interpreting symptoms related to prosthetic loosening or infection and 98% did not feel competent identifying radiological changes after arthroplasty. 94% of the General Practitioners did not think that they would be happy to follow up arthroplasty patients even if they were offered further training. The reasons for this were lack of specialty skills, work-load concerns, funding issues and surgeons’ duty of care towards the patient. All of the 104 patients who were questioned preferred to be followed up by the arthroplasty team. In conclusion, Orthopaedic Surgeons, General Practitioners and patients prefer a hospital based dedicated Orthopaedic team for the post operative follow-up of arthroplasty patients

This article considers the establishment, purpose and conduct of knee arthroplasty registers using the Swedish register as an example. The methods of collection of appropriate data, the cost, and the ways in which this information may be used are considered.

One of the problems of keeping an orthopaedic register is that radiographs, which are an integral part of records (particularly with total joint arthroplasties) are cumbersome and costly to store. We have developed a cheap and simple digital storage system, photographing radiographs with a digital camera and storing pictures in a specially designed database. Retrieval is rapid and hard copies can be printed. Over 10 000 arthroplasty radiographs have been digitalised by this inexpensive method, which could prove useful for most orthopaedic surgeons

In Scandinavia registers of locomotor system disease and trauma were developed in the mid 1970’s. In Sweden since then there exists registers of hip and knee arthroplasties and some years later similar registers were developed in Norway, Finland and Denmark. In 1988 a register on the treatment and rehabilitation of hip fractures started in Sweden and also since 1993 a spine register has been in use. The arthroplasty registers contain parameters concerning age, sex, diagnosis and technical factors for the operation. The outcome parameter is survival of the prosthesis e.g. if it has been revised or not. The real need to perform a revision arthroplasty has been considered a sufficiently well defined parameter to register. The hip fracture registration contains also background parameters as well as rehabilitation outcome including functional outcome parameters above all walking capacity and place of living. Functional outcome and patient rated quality of life are also included in the spine register. The arthroplasty registers have been very useful to separate better from not so well performing models as well as showing the importance of good cementing technique, type of cement as well as the influence of age, sex and diagnosis in a more rapid and reliable way because of the large-scale magnitude of the study. The hip fracture register has shown the importance of optimised operation and rehabilitation, which saves considerable resources in this increasing group of elderly patients. The symposium will exemplify performance, spread and results of orthopedic registers, which is an efficient way to evaluate on a large-scale everyday orthopedic practise. This way of registration has attracted great interest and is now spreading internationally. For hip fractures a European project has started called SAHFE (Standardised Audit of Hip Fractures in Europe)

Three or more years after completion of treatment, we re-examined 16 patients with orthopaedic problems associated with neurofibromatosis I (NF-I) who were treated at our institution between 1976 and 1999. Seven boys and five girls between the ages of 5 and 15 years presented with congenital pseudarthrosis of the tibia (CPT). All had undergone previous surgery elsewhere. The patients had typical skin lesions and the associated radiological appearances of pseudarthrosis of the tibia. There were two cystic types of CPT, five hourglass and five normotrophic types, mostly at the level of the distal third of the tibia. Primary consolidation of the CPT was not obtained in any patient. Three patients underwent below-knee amputation after multiple surgical procedures. Eight had consolidations of the pseudarthrosis after multiple operations, but all had residual deformities and/or shortening. One patient remained with a non-consolidation. The surgical procedures included intramedullary rodding with or without bone grafting, fibular bypass grafting, Soffield turn-about rodding, electrical stimulation, and, in patients seen since 1989, various Ilizarov techniques including lengthening and bone transport. Our results suggest that the best treatment of this perplexing paediatric orthopaedic problem remains undetermined. Considerations for the selection of treatment include the pathologic anatomic pattern of NF-I and the patient’s age and expectations. A National Orthopaedic Neurofibromatosis Register will be useful in the decision-making process