Aims. The aim of this study was to develop and evaluate machine-learning-based computerized adaptive tests (CATs) for the Oxford Hip Score (OHS), Oxford Knee Score (OKS), Oxford Shoulder Score (OSS), and the Oxford Elbow Score (OES) and its subscales. Methods. We developed CAT algorithms for the OHS, OKS, OSS, overall OES, and each of the OES subscales, using responses to the full-length questionnaires and a machine-learning technique called regression tree learning. The algorithms were evaluated through a series of simulation studies, in which they aimed to predict respondents’ full-length questionnaire scores from only a selection of their item responses. In each case, the total number of items used by the CAT algorithm was recorded and CAT scores were compared to full-length questionnaire scores by mean, SD, score distribution plots, Pearson’s correlation coefficient, intraclass correlation (ICC), and the Bland-Altman method. Differences between CAT scores and full-length questionnaire scores were contextualized through comparison to the instruments’ minimal clinically important difference (MCID). Results. The CAT algorithms accurately estimated 12-item questionnaire scores from between four and nine items. Scores followed a very similar distribution between CAT and full-length assessments, with the mean score difference ranging from 0.03 to 0.26 out of 48 points. Pearson’s correlation coefficient and ICC were 0.98 for each 12-item scale and 0.95 or higher for the OES subscales. In over 95% of cases, a patient’s CAT score was within five points of the full-length questionnaire score for each 12-item questionnaire. Conclusion. Oxford Hip Score, Oxford Knee Score, Oxford Shoulder Score, and Oxford Elbow Score (including separate subscale scores) CATs all markedly reduce the burden of items to be completed without sacrificing score accuracy. Cite this article: Bone Jt Open 2022;3(10):786–794

Background. Medical advances and an ageing population mean that more people than ever rely on artificial joints. In the past years, shoulder joint replacement has developed rapidly and the numbers of shoulder prostheses implanted increased dramatically. Wear is one of the main contributors to the failure of shoulder implants. It is therefore important to measure the wear properties of the articulating surfaces within the joint in vitro. Investigation of wear characteristics through a comprehensive range of motion using a sophisticated shoulder simulator would reveal the durability of the material, the performance of component design and the safety analyses of prostheses. The purpose of the work was to develop and validate a multi-station shoulder simulator, which could accurately simulate physiological gleno-humeral forces and displacements during activities of daily living. Materials and Methods. Imperial shoulder simulator was designed with six articulating stations and one loaded soak control station for anatomical shoulder system wear simulation. It gives an adduction-abduction (AA) range of-15° to 55°, flexion-extension (FE) range of −90° to 90° and internal external rotation (IER) range of 15° to −90°. The rotations are applied simultaneously to the humeral implants by using stepper motors with integral position encoders. Axial and shear loadings to each glenoid implant were applied using pneumatic cylinders. Force controlled translations were recorded using load cells and LVDTs, and a data acquisition system. Pneumatic cylinders were also installed to work to counterbalance weights during the motion of adduction-abduction. All bearing pairs are within isolated and sealed test chambers to prevent loss of fluid through evaporation, and cross contamination of third body wear (as recommended in F1714-96). The simulator is controlled by LabVIEW program allowing to reproduce shoulder activities of daily living. Results. A commissioning trial was conducted when shoulder implants were subject to rotational and translational motions and loading to replicate the ‘combing’ activity of daily living. The motion ranges were typically 5° to 15° in AA, 15° to 80° in FE, and −30° to −20° in IER with applied loads from 60 to 440 N, principally along the medio-lateral direction. The waveform was at frequency of 1 Hz. The activity was loaded at 250,000 cycles around 3 full days, when test and control specimens should be cleaned, measured and then re-installed into the simulator. The results from kinematic and kinetic inputs and outputs were obtained from the trial study. Discussion. A multi-station shoulder simulator was successfully developed, which is capable of reproducing typical activities of daily living by applying physiological patterns of motion and load. The performance of the simulator was validated in the commissioning trial, which leads to evaluation of novel implant designs

The purpose of this prospective pilot study is to examine the feasibility of a physiotherapist led rapid access shoulder screening clinic (RASC). The goal of this study is to assess for improvements in patient access to care, patient reported outcome measures, patient reported experience measures, and cost outcomes using time driven activity based costing methods. Patient recruitment began in January 2021. Consultation requests from general practitioners and emergency rooms are analyzed and triaged through a central system. One half of patients awaiting consultation were triaged to the traditional route used at our center while the other half were triaged to be assessed at the RASC. Outcome measures consisting of the Simple Shoulder Test and SF-12 were recorded at the initial consultation and at follow up appointments. Cost benefit analysis was conducted using time driven activity based costing methods (TD-ABC). From January to August of 2021, 123 new patients were triaged for RASC assessment. On average, the RASC gets 10 new referrals per month. As of September 2021, there are 65 patients still on waitlist for RASC assessment with 58 having been assessed. Of the 58, 11% were discharged through the RASC, 48% pursued private physiotherapy, 14% had injections, 19% proceeded on for surgical consultation, and 8% did not show. Over time same time period, approximately 15 new patients were seen in consultation by the surgeon's office. Thirty-five responses were obtained from RASC patients during their initial intake assessment. The average age of respondents was 54.7 with 21 females and 14 males. Median SF-12 scores in the physical dimension (PCS-12) for RASC patients were 36.82 and mental (MCS-12) 49.38927. Median Simple Shoulder Test scores measured 6. Of the patients who responded to the follow up questionnaires after completing physiotherapy at the RASC, both the SF-12 and Simple Shoulder Test scoring improved. Median PCS-12 measured 47.08, MCS-12 of 55.87, and Simple Shoulder Test measured 8. RASC assessments by PT saved $172.91 per hour for consultation and $157.97 per hour for patient follow ups. Utilization of a physiotherapy led rapid access shoulder clinic resulted in improvements in patient outcomes as measured by the SF-12 and Simple Shoulder Test as well as significant direct cost savings. Proper triage protocols to identify which patients would be suitable for RASC assessment, buy-in from physiotherapists, and timely assessment of patients for early initiation of rehabilitation for shoulder pain is paramount to the success of a RASC system at our centre. Future research direction would be geared to analyzing a larger dataset as it becomes available

Shoulder septic arthritis is uncommon and frequently misdiagnosed, resulting in severe consequences. This study evaluated the demographics, bacteriological profile, antibiotic susceptibility, treatment regimens, and clinical outcomes. This is a 10-year retrospective observational analysis of 30 patients (20 males and 10 females) who were treated for septic arthritis of the shoulder. The data collecting process utilised clinical records, laboratory archives, and x-ray archives. We gathered demographic information, pre- and post-intervention clinical data, serum biochemical markers, and the results of imaging examinations. All patients had a surgical arthrotomy and joint debridement in the operating room, and specimens were taken for culture and sensitivity testing. The specimens were cultivated for at least seventy-two hours. Shoulder joint ranges of motion, comorbidities, and the presence of osteomyelitis were assessed clinically to determine the outcome. All statistical analyses were conducted using the STATA 17 statistical software. Analysis of correlation between categorical variables was performed using the chi-squared test. The majority of the study patients were black Africans (97%). The age range of the group was from 8 days to 17 years. At presentation, 33% of patients had a low-grade fever, whereas the majority (60%) had normal body temperature. The average length of symptoms was 3.9 days (ranged from 1 day to 15 days), and the majority of patients had an increased white cell count (83%) and C-reactive protein (98%). There was accumulation of fluid in the joint of all individuals who received shoulder ultrasound imaging. We noted a significant incidence of gram-positive cocci, which were mostly susceptible to first-line antibiotics. Shoulder stiffness affected 63% of patients and chronic osteomyelitis affected 50% of individuals. Neither the severity nor the duration of the symptoms was related to an increased risk of osteomyelitis. The results of this study revealed that the clinical characteristics and bacterial profile of septic arthritis of the shoulder conform to typical patterns. The likelihood of osteomyelitis and an unfavourable prognosis is considerable

The diagnosis of infection following shoulder arthroplasty is notoriously difficult. The prevalence of prosthetic shoulder infection after arthroplasty ranges from 3.9 – 15.4% and the most common infective organism is Cutibacterium acnes. Current preoperative diagnostic tests fail to provide a reliable means of diagnosis including WBC, ESR, CRP and joint aspiration. Fluoroscopic-guided percutaneous synovial biopsy (PSB) has previously been reported in the context of a pilot study and demonstrated promising results. The purpose of this study was to determine the diagnostic accuracy of percutaneous synovial biopsy compared with open culture results (gold standard). This was a multicenter prospective cohort study involving four sites and 98 patients who underwent revision shoulder arthroplasty. The cohort was 60% female with a mean age was 65 years (range 36-83 years). Enrollment occurred between June 2014 and November 2021. Pre-operative fluoroscopy-guided synovial biopsies were carried out by musculoskeletal radiologists prior to revision surgery. A minimum of five synovial capsular tissue biopsies were obtained from five separate regions in the shoulder. Revision shoulder arthroplasty was performed by fellowship-trained shoulder surgeons. Intraoperative tissue samples were taken from five regions of the joint capsule during revision surgery. Of 98 patients who underwent revision surgery, 71 patients underwent both the synovial biopsy and open biopsy at time of revision surgery. Nineteen percent had positive infection based on PSB, and 22% had confirmed culture positive infections based on intra-operative tissue sampling. The diagnostic accuracy of PSB compared with open biopsy results were as follows: sensitivity 0.37 (95%CI 0.13-0.61), specificity 0.81 (95%CI 0.7-0.91), positive predictive value 0.37 (95%CI 0.13 – 0.61), negative predictive value 0.81 (95%CI 0.70-0.91), positive likelihood ratio 1.98 and negative likelihood ratio 0.77. A patient with a positive pre-operative PSB undergoing revision surgery had an 37% probability of having true positive infection. A patient with a negative pre-operative PSB has an 81% chance of being infection-free. PSB appears to be of value mainly in ruling out the presence of peri-prosthetic infection. However, poor likelihood ratios suggest that other ancillary tests are required in the pre-operative workup of the potentially infected patient

Osteoarthritis (OA) is a disease of the synovial joint with synovial inflammation, capsular contracture, articular cartilage degradation, subchondral sclerosis and osteophyte formation contributing to pain and disability. Transcriptomic datasets have identified genetic loci in hip and knee OA demonstrating joint specificity. A limited number of studies have directly investigated transcriptional changes in shoulder OA. Further, gene expression patterns of periarticular tissues in OA have not been thoroughly investigated. This prospective case control series details transcriptomic expression of shoulder OA by analysing periarticular tissues in patients undergoing shoulder replacement for OA as correlated with a validated patient reported outcome measure of shoulder function, an increasing (clinically worsening) QuickDASH score. We then compared transcriptomic expression profiles in capsular tissue biopsies from the OA group (N=6) as compared to patients undergoing shoulder stabilisation for recurrent instability (the control group, N=26). Results indicated that top ranked genes associated with increasing QuickDASH score across all tissues involved inflammation and response to stress, namely interleukins, chemokines, complement components, nuclear response factors and immediate early response genes. Some of these genes were upregulated, and some downregulated, suggestive of a state of flux between inflammatory and anti-inflammatory signalling pathways. We have also described gene expression pathways in shoulder OA not previously identified in hip and knee OA, as well as novel genes involved in shoulder OA

This study aims to correlate Oxford shoulder score (OSS) to EQ5D score in healthy patients presenting to a shoulder clinic with shoulder pain. OSS and EQ5D scores were collected prospectively from 101 consecutive patients presenting with shoulder pain in a shoulder clinic at one specialist centre. Patients with ASA > 2 and other significant joint arthritis were excluded from the study. Scores were collected from electronic patient records. Spearman's rho correlation of oxford shoulder scores and EQ5D scores was completed. Mean age of subjects was 51.8 (range 19.1–81.9) years, 55 of 101 subjects were men (54%). Median OSS was 26 (range 3–48) and median EQ5D score was 0.76 (range 0–0.76). Correlation for all patients was 0.624 (Sig p<0.001). This study demonstrates a strong correlation between Oxford shoulder scoring and EQ5D in a fit and well shoulder surgery clinic population. It is possible that Oxford shoulder scores may be a useful indicator of quality of life in healthy shoulder clinic patients presenting with shoulder pain

The choice of whether to perform antegrade intramedullary nailing (IMN) or plate fixation (PF) poses a conundrum for the surgeon who must strike the balance between anatomical restoration while reducing elbow and shoulder functional impairment. Most humeral middle third shaft fractures are amenable to conservative management given the considerable acceptable deformity and anatomical compensation by patients. This study is concerned with the patient reported outcomes regarding shoulder and elbow function for IMN and PF respectively. A prospective cohort study following up all the cases treated surgically for middle third humeral fractures from 2016 to 2022 at a single centre. Telephonically an analogue pain score, an American Shoulder and Elbow Society (ASES) score for shoulder function and the Oxford Elbow score (OES) for elbow function were obtained. One hundred and three patients met the inclusion criteria. Twenty four patients participated in the study, fifteen had IMN (62.5%) and nine had PF (37.5%.). The shoulder function outcomes showed no statistical difference with an average ASES score of sixty-six for the IMN group and sixty-nine for the PF group. Women and employed individuals expressed greater functional impairment. Hand dominance has no impact on the scores of elbow and shoulder function post operatively. The impairment of abduction score post antegrade nailing was higher in the antegrade nailing group than the plated group. The OES demonstrated greater variance in elbow function in the PF group with the IMN group expressing greater elbow disfunction. This study confirms that treatment of middle third humerus shaft fractures by plate fixation is marginally superior to antegrade intramedullary nailing in preserving elbow function and abduction ability

Os acromiale is a developmental defect caused by failure of fusion of the anterior epiphysis of the acromion between the ages of 22 and 25. The prevalence of os acromiale in the general population ranges from 1.4% to 15%. Os acromiale has been reported as a contributory factor to shoulder impingement symptoms and rotator cuff injuries, despite being a common incidental observation. In this retrospective study, we examined the prevalence of os acromiale in black African patients with shoulder pain. We retrospectively reviewed the clinical records, radiographs, and magnetic resonance imaging (MRI) scans of 119 patients who presented with atraumatic and minor traumatic shoulder pain at a single institution over a one-year period. Anteroposterior, scapula Y-view, and axillary view plain images were initially evaluated for the presence of os acromiale, and this was corroborated with axial MRI image findings. Patients with verified os acromiale had their medical records reviewed to determine their first complaint and the results of their clinical examination and imaging examination. Radiographs and MRI on 24 patients (20%) revealed an osacromiale. This cohort had a mean age of 59.2 years, and there were significantly more females (65%) than males. Meso-acromion was identified as the most prevalent type (n=11), followed by pre-os acromion (n=7). All patients underwent bilateral shoulder x-rays, and 45 percent of patients were found to have bilateral meso- acromion. Most patients (70%) were reported to have unstable os acromiale with subacromial impingement symptoms, and nine patients (36%) had confirmed rotator cuff tears based on clinical and Mri findings. Surgery was necessary for 47% of the 24 patients with confirmed Os acromiale (arthroscopic surgery, n=7; open surgery, n=1) in order to treat their symptoms. The prevalence of os acromiale in our African patients with atraumatic shoulder symptoms is greater than that reported in the general population. Os acromiale is a rare condition that should always be considered when evaluating shoulder pain patients

Anatomically specific fixation devices have become mainstream, yet there are anatomical regions and clinical conditions where no pre-contoured plates are available, such as for glenohumeral arthrodesis. In a case series of 4 glenohumeral arthrodesis patients, a consultant orthopaedic surgeon at GCUH implemented 3D printing technology to create reconstructions of each patient's shoulder girdle to pre-contour arthrodesis plates. Our aim was to quantify the cost-benefit & intra-operative time savings of this technique in glenohumeral arthrodesis. We hypothesized that the use of 3D printing for creating patient specific implants through pre-operative contouring of plates will lead to intra-operative time and cost savings by minimising time spent bending plates during surgery. This study analysed 4 patients who underwent shoulder arthrodesis by a single consultant orthopaedic surgeon at GCUH between 2017-2021. A CT-based life-size model of each patient's shoulder girdle was 3D printed using freely available computer software programs: 3D Slicer, Blender, Mesh Mixer & Cura. Once the patient's 3D model was created, plate benders were used to contour the plate pre-op, which was then sterilised prior to surgery. Arthrodesis was performed according to AO principles of fixation. The time spent pre-bending the plate using the 3D model was calculated to analyse the intra-op time and cost-saving benefits. For the 4 cases, the plate pre-bending times were 45, 40, 45 & 20 minutes (average 38.8 mins). The intra-op correction time to make small adjustments to the plate was 2 min/ case. 3 plates needed minor (3 degree) adjustment to fine-tune scapula spine contouring. 1 plate needed a 5 degree correction to fine-tune hand position. On average, the pre-bending of the plate saved approximately 38.8 mins intra-op/ case. These shorter anaesthetic and operating times equate to approximately $2586 saving/ case, given an estimate of $4000/hour of theatre costs. We conclude that pre-bending plates around 3D-printed life-size models of an individual's shoulder girdle prior to surgery results in approximately 38.8 mins time saving intra-op when used in shoulder arthrodesis. This is a viable and effective technique that will ultimately result in significant operative time and financial savings

Aim. Studies have shown that retention of antibiotic cement spacer in selected elderly patients with low functional demand represents a viable option for periprosthetic joint infections (PJI) treatment. 1,2. . The aim of this study is to compare the efficacy in infection treating among modular taylored preformed and hand-made antibiotic spacers. Our hypothesis is that modular tailored preformed spacer provides a better rate of infection resolution, better radiological and functional outcomes compared to hand-made spacers. Materials and methods. We identified 48 patients treated with antibiotic cement spacer for shoulder chronic infection between 2015 and 2021 in our institution; (13 hand-made spacers and 35 modular tailored preformed spacers). We collected data about comorbidities, associated microorganism, infection resolution, clinical and radiographic evaluation. Results. The mean age at surgery was 63.2 years, (45.8% female − 54.2% male), mean BMI 28.3. The mean time of infection diagnosis after first surgery was 30 months; (31.2% infection after ORIF in proximal humeral fractures, 68.8% PJI after shoulder arthroplasty). The main pathogens were Propionibacterium Acnes (37.5%), Staphylococcus Epidermidis (29.2%), Staphylococcus Aureus (16.7%), negative intraoperative coltures (14.6%), Enterococcus (4.17%), Pseudomonas Aeruginosa (4.17%). The mean time of antibiotic spacer retention was 18 months: 23 patients (47.9%) underwent second stage surgery for prosthesis implantation; 2 removed the spacer because of spacer dislocation, 2 died during follow up; while 21 patients still hold the antibiotic spacer (17 patients in treatment with prefabricated spacers and 4 with self-constructed spacer). The mean value for clinical assessment for patients with modular tailored preformed spacer were: Constant Score 34 – QuickDASH 40 – SST 33 – ASES Score 66 – VAS 2. Patients treated with hand-made spacer registered the following scores: Constant Score 20 – QuickDASH 51 – SST 25 – ASES Score 38 – VAS 6. Two patients presented fracture of the spacer (one hand-made spacer and one tailored preformed). Conclusions. According to our data patients treated with modular tailored preformed antibiotic spacer show better functional outcomes. Patients are more likely to retain the spacer as a permanent implant, avoiding the risks of a second stage surgery in those low-demanding patients, achieving a reasonable satisfying quality of shoulder motion without pain

Aim. Diagnosis of periprosthetic shoulder infections (PSI) is difficult as they are mostly caused by low-virulent bacteria and patients do not show typical infection signs, such as elevated blood markers, wound leakage, or red and swollen skin. Ultrasound-guided biopsies for culture may therefore be an alternative for mini-open biopsies as less costly and invasive method. The aim of this study was to determine the diagnostic value and reliability of ultrasound-guided biopsies for cultures alone and in combination polymerase chain reaction (PCR), and/or synovial markers for preoperative diagnosis of PSI in patients undergoing revision shoulder surgery. Method. A prospective explorative diagnostic cohort study was performed including patients undergoing revision shoulder replacement surgery. A shoulder puncture was taken preoperatively before incision to collect synovial fluid for interleukin-6 (IL-6), calprotectin, WBC, polymorphonuclear cells determination. Prior to revision surgery, six ultrasound-guided synovial tissue biopsies were collected for culture and two additional for PCR analysis. Six routine care tissue biopsies were taken during revision surgery and served as reference standard. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV; primary outcome measure), and accuracy were calculated for ultrasound-guided biopsies, and synovial markers, and combinations of these. Results. Fifty-five patients were included. In 24 patients, routine tissue cultures were positive for infection. Cultures from ultrasound-guided biopsies diagnosed an infection in 7 of these patients, yielding a sensitivity, specificity, PPV, NPV, and accuracy of 29.2%, 93.5%, 77.8%, 63.0%, and 65.6%, respectively. Ultrasound-guided biopsies in combination with synovial WBC increased the NPV to 76.7% and accuracy to 73.8%. When synovial WBC and calprotectin were combined with ultrasound-guided biopsies, it resulted in a better diagnostic value: sensitivity 69.2%, specificity 80.0%, PPV 69.2%, NPV 80.0%, and accuracy 75.8%. Ultrasound-guided biopsies in combination with calprotectin and ESR yielded a sensitivity of 50.0%, specificity of 93.8%, PPV of 80.0%, NPV of 78.9%, and accuracy of 79.2%. Synovial fluid was obtained in 42 patients. Sensitivities of WBC, PMN, IL-6, and calprotectin were between 25.0% and 35.7%, specificities between 89.5% and 95.0%, PPVs between 60.0% and 83.3%, NPVs between 65.4% and 69.4%, and accuracies between 64.5% and 70.6%. Conclusions. In this prospective study we showed that ultrasound-guided biopsies for cultures alone and in combination with PCR and/or synovial markers are not reliable enough to use in clinical practice for the preoperative diagnosis of low grade PSI

Aim. Clavicular osteotomy was described as an adjunct to deltopectoral approach for improved exposure of the glenohumeral joint. This study aims to present contemporary outcomes and complications associated with the routine use of clavicular osteotomy by a single surgeon in a regional setting within New Zealand. Methods. A retrospective case series of patients who have undergone any shoulder arthroplasty for any indication between March 2017 to August 2022. This time period includes all patients who had clavicular osteotomy(OS) and patients over an equal time period prior to the routine use of osteotomy as a reference group (N-OS). Oxford Shoulder Score (OSS) and a Simple Shoulder Test (STT) were used to assess functional outcomes and were compared with the reported literature. Operative times and Complications were reviewed. Results. 66 patients were included in the study. 33 patients in the OS group and 33 in the N-OS group. No difference in age, sex, indications for operative intervention and the surgery provided was identified. No significant difference in operative time between groups (N-OS 121 minutes; OS 128 minutes). No clinically significant difference was identified in the OSS (N-OS; mean 38 vs OS 39) or the STT (N-OS 8.3 vs OS 9). The outcomes scores of both groups are in keeping with published literature. Two post operative clavicle fractures, one prominent surgical knot occurred in the OS that required further surgical intervention. Two cases of localized pain over the clavicle and one case of the prominent lateral clavicle were reported in the OS group. Two cases of localized pain over clavicle reported in the N-OS group. Conclusion. Use of clavicular osteotomy is not associated with inferior patient reported. The osteotomy introduces specific risks, however, the study provides evidence that these complications are infrequent and avoidable. Surgeons should feel confident in using this adjunct when exposure to the shoulder is difficult

While clinically important improvements in Oxford Shoulder Scores have been defined for patients with general shoulder problems or those undergoing subacromial decompression, no threshold has been reported for classifying improvement after shoulder replacement surgery. This study aimed to establish the minimal clinically important change (MCIC) for the Oxford Shoulder Score in patients undergoing primary total shoulder replacement (TSR). Patient-reported outcomes data were sourced from the Australian Orthopaedic Association National Joint Replacement Registry Patient-Reported Outcome Measures Program. These included pre- and 6-month post-operative Oxford Shoulder Scores and a rating of patient-perceived change after surgery (5-point scale ranging from ‘much worse’ to ‘much better’). Two anchor-based methods (using patient-perceived improvement as the anchor) were used to calculate the MCIC: 1) mean change method; and 2) predictive modelling, with and without adjustment for the proportion of improved patients. The analysis included 612 patients undergoing primary TSR who provided pre- and post-operative data (58% female; mean (SD) age 70 (8) years). Most patients (93%) reported improvement after surgery. The MCIC derived from the mean change method was 6.8 points (95%CI 4.7 to 8.9). Predictive modelling produced an MCIC estimate of 11.6 points (95%CI 8.9 to 15.6), which reduced to 8.7 points (95%CI 6.0 to 12.7) after adjustment for the proportion of improved patients. For patient-reported outcome measures to provide valuable information that can support clinical care, we need to understand the magnitude of change that matters to patients. Using contemporary psychometric methods, this analysis has generated MCIC estimates for the Oxford Shoulder Score. These estimates can be used by clinicians and researchers to interpret important changes in pain and function after TSR from the patient's perspective. We conclude that an increase in Oxford Shoulder Scores of at least 9 points can be considered a meaningful improvement in shoulder-related pain and function after TSR

While clinically important improvements in Oxford Shoulder Scores have been defined for patients with general shoulder problems or those undergoing subacromial decompression, no threshold has been reported for classifying improvement after shoulder replacement surgery. This study aimed to establish the minimal clinically important change (MCIC) for the Oxford Shoulder Score in patients undergoing primary total shoulder replacement (TSR). Patient-reported outcomes data were sourced from the Australian Orthopaedic Association National Joint Replacement Registry Patient-Reported Outcome Measures Program. These included pre- and 6-month post-operative Oxford Shoulder Scores and a rating of patient-perceived change after surgery (5-point scale ranging from ‘much worse’ to ‘much better’). Two anchor-based methods (using patient-perceived improvement as the anchor) were used to calculate the MCIC: 1) mean change method; and 2) predictive modelling, with and without adjustment for the proportion of improved patients. The analysis included 612 patients undergoing primary TSR who provided pre- and post-operative data (58% female; mean (SD) age 70 (8) years). Most patients (93%) reported improvement after surgery. The MCIC derived from the mean change method was 6.8 points (95%CI 4.7 to 8.9). Predictive modelling produced an MCIC estimate of 11.6 points (95%CI 8.9 to 15.6), which reduced to 8.7 points (95%CI 6.0 to 12.7) after adjustment for the proportion of improved patients. For patient-reported outcome measures to provide valuable information that can support clinical care, we need to understand the magnitude of change that matters to patients. Using contemporary psychometric methods, this analysis has generated MCIC estimates for the Oxford Shoulder Score. These estimates can be used by clinicians and researchers to interpret important changes in pain and function after TSR from the patient's perspective. We conclude that an increase in Oxford Shoulder Scores of at least 9 points can be considered a meaningful improvement in shoulder-related pain and function after TSR

Revision surgeries for orthopaedic infections are done in two stages – one surgery to implant an antibiotic spacer to clear the infection and another to install a permanent implant. A permanent porous implant, that can be loaded with antibiotics and allow for single-stage revision surgery, will benefit patients and save healthcare resources. Gyroid structures can be constructed with high porosity, without stress concentrations that can develop in other period porous structures [1] [2]. The purpose of this research is to compare the resulting bone and prosthesis stress distributions when porous versus solid stems are implanted into three proximal humeri with varying bone densities, using finite element models (FEM). Porous humeral stems were constructed in a gyroid structure at porosities of 60%, 70%, and 80% using computer-aided design (CAD) software. These CAD models were analyzed using FEM (Abaqus) to look at the stress distributions within the proximal humerus and the stem components with loads and boundary conditions representing the arm actively maintained at 120˚ of flexion. The stem was assumed to be made of titanium (Ti6Al4V). Three different bone densities were investigated, representing a healthy, an osteopenic, and an osteoporotic humerus, with an average bone shape created using a statistical shape and density model (SSDM) based on 75 cadaveric shoulders (57 males and 18 females, 73 12 years) [3]. The Young's moduli (E) of the cortical and trabecular bones were defined on an element-by-element basis, with a minimum allowable E of 15 MPa. The Von Mises stress distributions in the bone and the stems were compared between different stem scenarios for each bone density model. A preliminary analysis shows an increase in stress values at the proximal-lateral region of the humerus when using the porous stems compared to the solid stem, which becomes more prominent as bone density decreases. With the exception of a few mesh dependent singularities, all three porous stems show stress distributions below the fatigue strength of Ti-6Al-4V (410 MPa) for this loading scenario when employed in the osteopenic and osteoporotic humeri [4]. The 80% porosity stem had a single strut exceeding the fatigue strength when employed in the healthy bone. The results of this study indicate that the more compliant nature of the porous stem geometries may allow for better load transmission through the proximal humeral bone, better matching the stress distributions of the intact bone and possibly mitigating stress-shielding effects. Importantly, this study also indicates that these porous stems have adequate strength for long-term use, as none were predicted to have catastrophic failure under the physiologically-relevant loads. Although these results are limited to a single boney geometry, it is based on the average shape of 75 shoulders and different bone densities are considered. Future work could leverage the shape model for probabilistic models that could explore the effect of stem porosity across a broader population. The development of these models are instrumental in determining if these structures are a viable solution to combatting orthopaedic implant infections

Orthopaedic surgeons prescribe more opioids than any other surgical speciality. Opioids remain the analgesic of choice following arthroscopic knee and shoulder surgery. There is growing evidence that opioid-sparing protocols may reduce postoperative opioid consumption while adequately addressing patients’ pain. However, there are a lack of prospective, comparative trials evaluating their effectiveness. The objective of the current randomized controlled trial (RCT) was to evaluate the efficacy of a multi-modal, opioid-sparing approach to postoperative pain management in patients undergoing arthroscopic shoulder and knee surgery. The NO PAin trial is a pragmatic, definitive RCT (NCT04566250) enrolling 200 adult patients undergoing outpatient shoulder or knee arthroscopy. Patients are randomly assigned in a 1:1 ratio to an opioid-sparing group or standard of care. The opioid-sparing group receives a three-pronged prescription package consisting of 1) a non-opioid prescription: naproxen, acetaminophen and pantoprazole, 2) a limited opioid “rescue prescription” of hydromorphone, and 3) a patient education infographic. The control group is the current standard of care as per the treating surgeon, which consists of an opioid analgesic. The primary outcome of interest is oral morphine equivalent (OME) consumption up to 6 weeks postoperatively. The secondary outcomes are postoperative pain scores, patient satisfaction, quantity of OMEs prescribed and number of opioid refills. Patients are followed at both 2 and 6 weeks postoperatively. Data analysts and outcome assessors are blinded to the treatment groups. As of December 1, 2021 we have enrolled 166 patients, reaching 83% of target enrolment. Based on the current recruitment rate, we anticipate that enrolment will be completed by the end of January 2022 with final follow-up and study close out completed by March of 2022. The final results will be released at the Canadian Orthopaedic Association Meeting in June 2022 and be presented as follows. The mean difference in OME consumption was XX (95%CI: YY-YY, p=X). The mean difference in OMEs prescribed was XX (95%CI: YY-YY, p=X). The mean difference in Visual Analogue Pain Scores (VAS) and patient satisfaction are XX (95%CI: YY-YY, p=X). The absolute difference in opioid refills was XX (95%CI: YY-YY, p=X). The results of the current study will demonstrate whether an opioid sparing approach to postoperative outpatient pain management is effective at reducing opioid consumption while adequately addressing postoperative pain in patients undergoing outpatient shoulder and knee arthroscopy. This study is novel in the field of arthroscopic surgery, and its results will help to guide appropriate postoperative analgesic management following these widely performed procedures

Introduction. Initial fixation of noncemented implants is critical to achieve a stable bone/implant interface during the first few months after surgery to potentiate bone in-growth and avoid aseptic loosening. Numerous reverse shoulder glenoid implant designs have been conceived in an attempt to improve implant performance and decrease the rate of aseptic glenoid loosening, commonly reported to be 5%. Design variations include: baseplate profile, baseplate size, backside geometry, center of rotation, surface finish and coatings, fixation screw diameters, number of fixation screw options, and type of screw fixation. However, little comparative biomechanical data exist to substantiate one design consideration over another. To that end, this study quantified glenoid fixation before and after cyclic loading of simulated abduction of 6 different reverse shoulder glenoid designs when secured to a low density polyurethane bone substitute block. Methods. A displacement test quantified fixation of 6 different reverse shoulder designs: 38 mm Equinoxe standard offset (EQ), 38 mm Equinoxe lateral offset (EQL), 36 mm Depuy Delta III (DRS), 36 mm Zimmer, (ZRS), 32 mm neutral DJO RSP (DJO), and a 36 mm Tornier BIO-RSA (BIO), secured to a 0.24 g/cm. 3. polyurethane block as a shear (357 N) and compressive (50 N) load was applied before and after cyclic loading. (Figure 1) Glenoid displacement was measured relative to the block using dial indicators in the directions of the applied loads along the superior/inferior axis. A cyclic test rotated each glenosphere (n = 7 for each design) about a 55° arc of abduction at 0.5 Hz for 10k cycles as 750N was constantly applied. (Figure 2) Each implant was cycled using a 145° humeral liner of the appropriate diameter to ensure each device is subjected to the same shear load. A two-tailed unpaired student's t-test was used to compare pre- and post-cyclic mean displacements between designs; p < 0.05 denotes significance. Results. The average pre-cyclic displacement of the EQ, EQL, DRS, ZRS, DJO, and BIO devices was 181, 137, 186, 381, 238, 232 microns, respectively. The average post-cyclic displacement of the EQ, EQL, DRS, DJO, and BIO devices was 186, 129, 189, 368, 249 microns, respectively. During the cyclic test, 6 of 7 ZRS devices failed at an average of 2603 cycles, 1 of 7 DJO failed at 7342 cycles, and 4 of 7 BIO devices failed at an average of 2926 cycles. All 7 of the EQ, EQL, and DRS devices remained well fixed throughout cyclic loading. Discussion and Conclusions. The results of this study demonstrate significant difference in fixation associated 6 different reverse shoulder designs. Despite many similarities in geometry between these designs, significant differences in fixation were observed between nearly every implant design tested. This suggests that subtle changes in glenoid baseplate design can dramatically impact fixation, particularly in low density bone substitutes which are intended to simulate the bone quality of the recipient population for reverse shoulders. Future work should attempt to isolate which design parameters are the most critical contributors for initial fixation and ultimately, long-term stability

Aim. A significant number of patients undergoing shoulder arthroplasty surgery have C acnes contamination at the end of the primary surgery. The objective of this study is to determine whether patients with C acnes contamination at the end of their primary shoulder surgery have a worse prognosis than those who end up without C. acnes contamination. Method. Prospective study including all patients who underwent a reverse shoulder prosthesis from January 2015 to December 2018. In all of them, 5 to 12 cultures were performed during primary surgery. The patients underwent surgery for shoulder arthritis secondary to rotator cuff tears, acute fracture of the proximal humerus, and sequelae of fracture of the proximal humerus. Exclusion criteria included the existence of previous surgeries on the affected shoulder, the presence of signs of infection, having received infiltrations and / or complementary invasive examinations (Arthro-MRI and Arthro-CT). Follow-up from 2 to 5 years. Functional assessment according to the Constant Functional Scale. All complications were also recorded. Results. 162 patients were included. Of these, 25 had positive cultures for C. acnes at the end of primary shoulder surgery. Average age of 74.8 years. 136 women and 26 men. 75.9% Shoulder arthritis secondary to rotator cuff tears, 13.6% acute fractures and 10.5% sequelae of fractures. There were no differences between patients with C. acnes and those without C. acnes regarding age and indication for surgery. Predominance of men in the group with positive C. acnes (p <0.001). No differences at 2 and 5 years in the Constant functional scale between the two groups (2 years, 59.6 vs 59.2 p 0.870) (5 years, 62.4 vs 59.5 p 0.360). Significant differences regarding the number of complications (p 0.001). Patients without C. acnes had 1 aseptic loosening of the metaglene and patients with C. acnes had 2 infections, 1 dislocation, and 1 revision surgery. Patients with contamination by C. acnes had more comorbidities (p 0.035) than patients without contamination. Conclusions. Patients with C acnes contamination at the end of primary surgery do not have functional differences when compared with patients without contamination at 2 and 5 years, but they have a higher number of complications in the medium term

The use of scoring systems for surveillance of post-operative outcomes is increasing. However, the methodology of this follow-up is not universal. We set out to assess whether a postal Oxford Shoulder Score (OSS) was sufficient to identify patients who were dissatisfied and wanted further treatment. Of 88 patients who had undergone GlobalCap resurfacing in the previous 5 years, we received a completed postal OSS (Median score 33, Range 5–48) from 80 patients. Those with a score <24 (an agreed threshold for surgery pre-operatively) were brought to clinic for review. The 16 recalled patients (2 males, 14 females; age 58–85) had their OSS repeated, supervised by a clinic nurse, and had a Constant Score and an American Shoulder and Elbow Surgeons (ASES) Score performed. Satisfaction was also questioned. OSS correlated well with the Constant Score (r=0.79) and ASES (r=0.86). However, supervision increased the OSS by an average of 6 points (Mean 13.9 to 19.9) and only three of the patients proved dissatisfied with the outcome of their surgery. Used alone, an unobserved OSS may have limited value for this purpose and the use of comparative pre-operative scores or additional patient-reported outcome measures may be necessary to detect poor outcomes