AbstractFrozen shoulder is a painful condition that often requires surgery and affects up to 5% of individuals aged 40-60 years. Little is known about the causes of the condition, but diabetes is a strong risk factor. To begin to understand the biological mechanisms involved, we aimed to identify genetic variants associated with frozen shoulder and to use Mendelian randomization to test the causal role of diabetes.We performed a genome wide association study (GWAS) of frozen shoulder in the UK Biobank using data from 2064 cases identified from ICD-10 codes. We used data from FinnGen for replication. We used one-sample and two-sample Mendelian randomization approaches to test for a causal association of diabetes with frozen shoulder.We identified a single genome-wide significant locus (lead SNP rs62228062; OR=1.34 [1.28-1.41], p=2×10−16) that contained WNT7B. A recent transcriptome study identified WNT7B as amongst the most enriched transcripts in anterior capsule tissue in patients undergoing arthroscopic capsulotomy surgery for frozen shoulder suggesting WNT7B as a potential causal gene at the locus. The lead SNP was also strongly associated with Dupuytren’s contracture (OR=2.61 [2.50, 2.72], p<1×10−100). The Mendelian randomization results provided evidence that type 1 diabetes is a causal risk factor for frozen shoulder (OR=1.04 [1.02-1.07], p=6×10−5). There was no evidence that obesity was causally associated with frozen shoulder, suggesting that diabetes influences risk of the condition through glycemic rather than mechanical effects.We have identified the first genetic variant associated with frozen shoulder. WNT7B is a potential causal gene at the locus. Diabetes is a likely causal risk factor. Our results provide evidence of biological mechanisms involved in this common painful condition.

Background This radiological study aims to assess the prevalence of lateral elbow pathology in an asymptomatic population using 3.0T magnetic resonance imaging (MRI). Methods Bilateral elbow MRI was undertaken in 30 asymptomatic volunteers. Exclusion criteria included elbow pain within 3 months, elbow trauma or previous diagnosis of lateral epicondylar tendinopathy. Baseline patient-reported outcome measures were recorded along with age and body mass index (BMI). Two musculoskeletal radiologists independently graded the degree of abnormality at the common extensor tendon. Results Thirty volunteers were categorised according to age; 35–44 ( n = 10), 45–54 ( n = 11), and 55–65 ( n = 9) with a 1:1 male-to-female ratio. Radiological evidence of tendon abnormality was found in 37% of volunteers. The proportion with abnormal findings increased with age; 35–44 (10%), 45–54 (36%), 55–65 (67%) and BMI; 18–24.9 (23%), 25–29.9 (43%), > 30 (67%). Changes were generally ‘mild’ or ‘moderate’, with a single volunteer showing ‘severe’ pathology. Kappa for the radiographic agreement was 0.91 (0.83–0.98). Discussion This study has demonstrated MRI findings suggestive of pathology at the common extensor tendon to be prevalent in an asymptomatic population, increasing with age and BMI. This draws into question the diagnostic and prognostic value of MRI imaging in lateral epicondylar tendinopathy, especially in older patients.

OBJECTIVES: to develop a core outcome set for lateral elbow tendinopathy (COS-LET) and to provide guidance for outcome evaluation in future studies. METHODS: We implemented a multi-stage mixed-methods design combining two systematic reviews, domain mapping of outcome measurement instruments to the core domains of tendinopathy, psychometric analysis of instruments, two patient focus groups and a Delphi study incorporating two surveys and an international consensus meeting. Following the OMERACT guidelines, we used a 70% threshold for consensus. RESULTS: 38 clinicians/researchers and 9 patients participated. 60 instruments were assessed for inclusion. The only instrument that was recommended for the COS-LET was Patient Rated Tennis Elbow Evaluation (PRTEE) for the disability domain. Interim recommendations were made to use: the PRTEE function subscale for the function domain; PRTEE pain subscale items 1, 4 and 5 for the pain over a specified time domain; pain-free grip strength for the physical function capacity domain; a Numerical Rating Scale measuring pain on gripping for the pain on activity/loading domain; and time off work for the participation in life activities domain. No recommendations could be made for the quality-of-life, patient rating of condition and psychological factors domains. CONCLUSIONS: the COS-LET comprises the PRTEE for the disability domain. Interim-use recommendations included PRTEE subscales, time off work, pain-free grip strength and a Numerical Rating Scale measuring pain on gripping. Further work is required to validate these interim measures and develop suitable measures to capture the other domains.

Background and purpose: This study aims to determine, for the first time, generalizable data on the longevity and long-term function of elbow replacements.Methods: in this systematic review and meta-analysis, we searched MEDLINE and Embase for articles reporting 10-year or greater survival of total elbow replacements (TERs) and distal humeral hemiarthroplasty. Implant survival and patient reported outcome measures (PROMs) data were extracted. National joint replacement registries were also analyzed. We weighted each series and calculated a pooled survival estimate at 10, 15, and 20 years. For PROMs we pooled the standardized mean difference (SMD) at 10 years.Findings: Despite its widespread use, we identified only 9 series reporting all-cause survival of 628 linked TERs and 610 unlinked TERs and no series for distal humeral hemiarthroplasty. The studied population was treated for rheumatoid arthritis in over 90% of cases. The estimated 10-year survival for linked TERs was 92% (95% CI 90–95) and unlinked TERs 84% (CI 81–88). 2 independent registries contributed 32 linked TERs and 530 unlinked TERs. The pooled registry 10-year survival for unlinked TERs was 86% (CI 83–89). Pooled 10-year PROMs from 164 TERs (33 linked and 131 unlinked), revealed a substantial improvement from baseline scores (SMD 2.7 [CI 1.6–3.8]).Interpretation: over 80% of all elbow replacements and over 90% of linked elbow replacements can last more than 10 years with sustained patient-reported benefits. This information is long overdue and will be particularly useful to patients as well as healthcare providers.

AIMS: the use and variety of stemless humeral components in anatomical total shoulder arthroplasty (TSA) have proliferated since their advent in 2004. Early outcomes are reassuring but independent mid-term results are scarce. This independent study reports a consecutive series of 143 Eclipse stemless shoulder prostheses with a minimum five-year (5 to 10) follow-up. METHODS: Outcomes of 143 procedures undertaken for all indications in 131 patients were reviewed, with subset analysis of those for osteoarthritis (OA) (n = 99). The primary outcome was the Oxford Shoulder Score (OSS) at a minimum of five years. Secondary outcomes were ranges of motion and radiological analysis of humeral radiolucency, rotator cuff failure, and glenoid loosening. RESULTS: Mean OSS at mean follow-up of 6.67 years (5.0 to 10.74) was 40.12 (9 to 48), with no statistically significant difference between those implanted for a non-OA indication and those for OA (p = 0.056) or time-dependent deterioration between two years and five years (p = 0.206). Ranges of motion significantly improved compared with preoperative findings and were maintained between two and five years with a mean external rotation of 38° (SD 18.1, 0 to 100) and forward elevation of 152° (SD 29.9, 90 to 180). of those components with radiographs suitable for analysis (n = 83), 23 (28%) were found to have a least one humeral radiolucent line, which were predominantly incomplete, less than 2 mm, and in a single anatomical zone. No humeral components were loose. A radiolucent line was present around 22 (15%) of glenoid components, and 15 (10%) of components had failed. Rotator cuff failure was found in 21 (15%) components. The mean time to either glenoid or rotator cuff failure was greater than three years following implantation. Survivorship was 96.4% (95% CI 91.6 to 98.5, number at risk 128) at five years, and 94.3% (95% CI 88.2 to 97.3, number at risk 76) at seven years, both of which compare favourably with best results taken from available registries. CONCLUSION: Functional and radiological outcomes of the Eclipse stemless TSA are excellent, with no loose humeral components at minimum five-year follow-up. The presence of radiolucent lines is of interest and requires long-term observation but does not impact on the clinical results. of the eight revisions required, this was predominantly for glenoid and rotator cuff failure. Cite this article: Bone Joint J 2022;104-B(1):83-90.

Background Early diagnosis and fixation of fractures unlikely to unite can prevent months of morbidity. The Radiographic Union Score for Humeral fractures (RUSHU) is a summative scoring system developed to aid identification of patients at higher risk of developing humeral shaft non-union. Plain radiographs taken six weeks after injury are given a score between four and 12 based on signs of union. Our aim was to assess the validity of the RUSHU prognostic model in an external population. Methods the radiographs of fifty-seven patients were scored independently according to RUSHU methodology by three reviewers (blinded to patient outcome). Interobserver intraclass correlation (ICC) was calculated. Results of the cohort, six (10.5%) progressed to non-union after six months. We observed an interobserver ICC co-efficient of 0.89 (95%CI0.84,0.93) in RUSHU score at six weeks. Median score was significantly higher in the union cohort (10v5 p < 0.001). Using the score of < 8 to predict non-union gave an area under the ROC curve of 0.87 (95%CI 0.83,0.90). Conclusions in this retrospective single-centre study, we have demonstrated good inter-rater reliability. We would suggest that the RUSHU model be assessed in further external validation studies. RUSHU has the potential to reduce morbidity of delayed treatment of non-union.

Aims: Revision knee replacement is an increasingly common procedure, however, information on patient-focused outcomes is limited. This systematic review and meta-analysis aimed to investigate the medium-term patient reported outcomes following a revision knee replacement. Methods: We performed a systematic review of MEDLINE and EMBASE (from inception to 1st March 2021) for articles reporting five year or greater patient reported outcome measures (PROMs) following revision knee replacement. A meta-analysis of PROMs data was undertaken using the Standardised Mean Difference (SMD). Quality of methodology was assessed using Wylde's non-summative four-point system. The study was registered with PROPSERO (CRD42021199289). Results: a total of 23 studies met the inclusion criteria containing 2414 patients at a mean minimum follow-up of 74 months (60–122). The reporting of PROMs were poorly standardised with several PROMs being used. The most commonly reported patient reported outcome was the Knee Society Score reported in 65% of studies (15/23). A meta-analysis of 629 eligible patients undergoing revision knee replacement revealed a significant improvement in pre-operative state with a SMD 2·05 95% CI 0.87, 3.23. Conclusion: This systematic review has found a significant and sustained improvement in patient-reported outcomes following a revision knee arthroplasty beyond five years. We found a variation in the usage and administration of PROMs which hinders a clear synthesis of results. Furthermore, the PROMs have not been robustly tested for validity in the context of a revision knee replacement.

Background: Total elbow arthroplasty is a low volume procedure. We aimed to evaluate complication rates and cumulative percentages associated with the most frequently used contemporary implants and for the commonest indications. Methods: a systematic literature search of all studies reporting complications following total elbow arthroplasty with 12-month minimum follow-up was undertaken. Quality of studies was assessed with the Methodological-Index-for-Non-Randomised-studies criteria. British NJR data identified the most common UK prostheses and indications. The complication rates for all undesirable events contributing to patient outcome were extracted and cumulative percentages were calculated. Results: One hundred seventeen studies were screened, 12 studies included, totalling 815 procedures. Mean follow-up was 3.8 years. The overall complication cumulative percentage was 60.7%, significantly higher than that seen in other joint arthroplasty, including a 6.5% deep infection rate. Nerve injury was comparable between implants at around 4.1%. Radiographic loosening had a cumulative rate of 17.2%. Revision for symptomatic aseptic loosening was 6.3%. Conclusions: This is the largest systematic review of the complications of total elbow arthroplasty. Surgeons should be aware of differing complications related to their implant of choice, each having its own specific complication. Trauma as an indication appears to have an increased complication rates compared to inflammatory arthropathy. There is a lack of literature regarding the independent results of osteoarthritis as a specific indication for total elbow arthroplasty.

BACKGROUND: Platelet-rich plasma (PRP) is widely used in the management of lateral elbow tendinopathy (LET) despite conflicting evidence on its effectiveness. With high levels of user experience, this study aimed to assess consensus amongst experts on its clinical use. METHODS: a three-round international Delphi study was conducted. Participants were invited through national society mailing lists and contact lists derived from a systematic search of the literature on PRP. In round one, a primary working group developed 40 statements on PRP preparation and clinical application. In rounds two and three, an international group of researchers on PRP and clinical users of the device scored their levels of agreement with the statements on a five-point scale. Consensus was defined as an interquartile range of ≤ 1. RESULTS: Consensus of agreement was only reached for 17/40 (42.5%) statements. For statements on PRP formulation, consensus of agreement was reached in 2/6 statements (33%). Only limited consensus on the contraindications, delivery strategy and delivery technique was achieved. CONCLUSION: Experts reached very limited consensus on the use of PRP in LET. High levels of user experience have not resulted in a convergence of opinion on the technical components of PRP formulation and delivery, substantiating the need for further studies and improved trial reporting.

Background: Prosthetic joint infection (PJI) causes significant morbidity and mortality following knee replacement surgery. Identifying causative organisms and antibiotic sensitivities is critical in increasing the chance of infection eradication. This study investigated whether biopsy alone was superior to aspiration alone for serological diagnosis in PJI following knee replacement. Secondly, we investigated whether biopsy identifies the same or new/different microbiological flora as aspiration. Methods: Since December 2014, the Exeter Knee Reconstruction Unit (EKRU) has prospectively collated data regarding all PJIs referred from our local/regional network which have been reviewed via our Multi-Disciplinary Team (MDT). We identified and included consecutive patients from this MDT from Dec.2014-Mar.2020 and analysed their electronic records. Statistical analysis was performed using Stata. Results: 65/100 patients studied had both pre-operative aspiration and biopsy. 31/65 (48%) had positive aspiration and biopsies. No aspirate samples were positive with corresponding biopsies negative. In 19/65 (29%) of infection positive patients, biopsy identified new (7) or additional (12) organisms not identified by aspiration. Aspiration had a sensitivity of 70%, specificity of 88%, positive predictive value of 90.3% and negative predictive value of 64.7%. Biopsy had a sensitivity of 97.5%, specificity of 88%, positive predictive value of 92.9% and negative predictive value of 95.7%. Conclusion: in 29% of confirmed PJI cases, arthroscopic biopsy identified either additional organisms in a polymicrobial PJI when compared to aspiration, or new positive results when aspiration alone was negative. This study demonstrates the benefits of arthroscopic biopsy for serological diagnosis in cases of knee PJI and aids treatment planning.

Background: Lateral elbow tendinopathy (LET) is a common condition that can cause significant disability and associated socioeconomic cost. Although it has been widely researched, outcome measures are highly variable which restricts evidence synthesis across studies. In 2019, a working group of international experts, health care professionals and patients, in the field of tendinopathy (International Scientific Tendinopathy Symposium Consensus (ICON) Group), published the results of a consensus exercise defining the nine core domains that should be measured in tendinopathy research. The aim of this study is to develop a core outcome set (COS) for LET mapping to these core domains. The primary output will provide a template for future outcome evaluation of LET. In this protocol, we detail the methodological approach to the COS-LET development. Methods: This study will employ a three-phase approach. (1) a systematic review of studies investigating LET will produce a comprehensive list of all instruments currently employed to quantify the treatment effect or outcome. (2) Instruments will be matched to the list of nine core tendinopathy outcome domains by a Steering Committee of clinicians and researchers with a specialist interest in LET resulting in a set of candidate instruments. (3) an international three-stage Delphi study will be conducted involving experienced clinicians, researchers and patients. Within this Delphi study, candidate instruments will be selected based upon screening using the Outcome Measures in Rheumatology (OMERACT) truth, feasibility and discrimination filters with a threshold of 70% agreement set for consensus. Conclusions: There is currently no COS for the measurement or monitoring of LET in trials or clinical practice. The output from this project will be a minimum COS recommended for use in all future English language studies related to LET. The findings will be published in a high-quality journal and disseminated widely using professional networks, social media and via presentation at international conferences. Trial registration: Registered with the Core Outcome Measures in Effectiveness Trials (COMET) database, November 2019. https://www.comet-initiative.org/Studies/Details/1497.

BACKGROUND: Patient-reported outcomes measures (PROMs) assess a patient's subjective appraisal of health outcomes from their own perspective. Despite hypothesised benefits that feedback  on PROMs can support decision-making in clinical practice and improve outcomes, there is uncertainty surrounding the effectiveness of PROMs feedback. OBJECTIVES: to assess the effects of PROMs feedback to patients, or healthcare workers, or both on patient-reported health outcomes and processes of care. SEARCH METHODS: We searched MEDLINE, Embase, CENTRAL, two other databases and two clinical trial registries on 5 October 2020. We searched grey literature and consulted experts in the field. SELECTION CRITERIA: Two review authors independently screened and selected studies for inclusion. We included randomised trials directly comparing the effects on outcomes and processes of care of PROMs feedback to healthcare professionals and patients, or both with the impact of not providing such information. DATA COLLECTION AND ANALYSIS: Two groups of two authors independently extracted data from the included studies and evaluated study quality. We followed standard methodological procedures expected by Cochrane and EPOC. We used the GRADE approach to assess the certainty of the evidence. We conducted meta-analyses of the results where possible. MAIN RESULTS: We identified 116 randomised trials which assessed the effectiveness of PROMs feedback in improving processes or outcomes of care, or both in a broad range of disciplines including psychiatry, primary care, and oncology. Studies were conducted across diverse ambulatory primary and secondary care settings in North America, Europe and Australasia. A total of 49,785 patients were included across all the studies. The certainty of the evidence varied between very low and moderate. Many of the studies included in the review were at risk of performance and detection bias. The evidence suggests moderate certainty that PROMs feedback probably improves quality of life (standardised mean difference (SMD) 0.15, 95% confidence interval (CI) 0.05 to 0.26; 11 studies; 2687 participants), and leads to an increase in patient-physician communication (SMD 0.36, 95% CI 0.21 to 0.52; 5 studies; 658 participants), diagnosis and notation (risk ratio (RR) 1.73, 95% CI 1.44 to 2.08; 21 studies; 7223 participants), and disease control (RR 1.25, 95% CI 1.10 to 1.41; 14 studies; 2806 participants). The intervention probably makes little or no difference for general health perceptions (SMD 0.04, 95% CI -0.17 to 0.24; 2 studies, 552 participants; low-certainty evidence), social functioning (SMD 0.02, 95% CI -0.06 to 0.09; 15 studies; 2632 participants; moderate-certainty evidence), and pain (SMD 0.00, 95% CI -0.09 to 0.08; 9 studies; 2386 participants; moderate-certainty evidence). We are uncertain about the effect of PROMs feedback on physical functioning (14 studies; 2788 participants) and mental functioning (34 studies; 7782 participants), as well as fatigue (4 studies; 741 participants), as the certainty of the evidence was very low. We did not find studies reporting on adverse effects defined as distress following or related to PROM completion. AUTHORS' CONCLUSIONS: PROM feedback probably produces moderate improvements in communication between healthcare professionals and patients as well as in diagnosis and notation, and disease control, and small improvements to quality of life. Our confidence in the effects is limited by the risk of bias, heterogeneity and small number of trials conducted to assess outcomes of interest. It is unclear whether   many of these improvements are clinically meaningful or sustainable in the long term. There is a need for more high-quality studies in this area, particularly studies which employ cluster designs and utilise techniques to maintain allocation concealment.

AIMS: Shoulder replacement is increasingly performed for end-stage arthritis. Information on the long-term survival and patient outcomes is very limited. This study aimed to quantify the survival and clinical outcome at a minimum of 20-yr follow-up. METHODS: a single-center, single-surgeon, consecutive cohort study was performed. Forty-four shoulder replacements in 40 patients (age at surgery 68.5 years, 82.5% female, preoperative visual analog scale [VAS] pain score 5.1/10, standard deviation [SD] 2.7) implanted between 1996 and 2000 were assessed. All-cause construct survival, radiographic glenoid and humeral stem loosening, radiographic humeral head migration, and patient-reported outcome measures were assessed. RESULTS: Survival with all-cause revision as an endpoint was 84.1% (95% confidence interval [CI] 60.7, 94.1) at 20 years, glenoid loosening was seen in all patients who survived to the 20-year follow-up. Survival of rotator cuff integrity was 16.8% (95% CI 3.5, 38.5) at 20 years. VAS pain scores demonstrated improvement at 10 years (mean change -4/10) but not at 20 years (effect size -0.15, mean change 0.4/10, SD 2.7). At 20 years, 72% of patients had died with the prosthesis in situ. CONCLUSION: Older patients undergoing total shoulder arthroplasty are unlikely to require revision in their lifetime. However, beyond 10 years, a large proportion of implants demonstrate glenoid loosening, humeral head migration, and declining patient outcomes. This information will be of use to patients and clinicians when discussing the potential outcomes of surgery.

Abstract
.
. Background
. During the initial COVID-19 outbreak up to 28.4 million elective operations were cancelled worldwide, in part owing to concerns that it would be unsustainable to maintain elective surgery capacity because of COVID-19-related surgeon absence. Although many hospitals are now recovering, surgical teams need strategies to prepare for future outbreaks. This study aimed to develop a framework to predict elective surgery capacity during future COVID-19 outbreaks.
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.
. Methods
. An international cross-sectional study determined real-world COVID-19-related absence rates among surgeons. COVID-19-related absences included sickness, self-isolation, shielding, and caring for family. To estimate elective surgical capacity during future outbreaks, an expert elicitation study was undertaken with senior surgeons to determine the minimum surgical staff required to provide surgical services while maintaining a range of elective surgery volumes (0, 25, 50 or 75 per cent).
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.
. Results
. Based on data from 364 hospitals across 65 countries, the COVID-19-related absence rate during the initial 6 weeks of the outbreak ranged from 20.5 to 24.7 per cent (mean average fortnightly). In weeks 7–12, this decreased to 9.2–13.8 per cent. At all times during the COVID-19 outbreak there was predicted to be sufficient surgical staff available to maintain at least 75 per cent of regular elective surgical volume. Overall, there was predicted capacity for surgeon redeployment to support the wider hospital response to COVID-19.
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.
. Conclusion
. This framework will inform elective surgical service planning during future COVID-19 outbreaks. In most settings, surgeon absence is unlikely to be the factor limiting elective surgery capacity.
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Sutures are essential to approximate tissues and enable healing by first intention until a wound regains its original tensile strength. The mechanical properties of sutures are well documented, but the effects of exposing sutures to skin preparation solutions used in surgery are not. This study was performed to investigate whether 2% chlorhexidine and 70% isopropyl alcohol skin preparation, commonly used prior to incision and prior to closure, has any effect on the mechanical properties of several commonly used surgical suture types. Four suture types were soaked in either 2% chlorhexidine and 70% isopropyl alcohol or Hartmann's solution for 5 minutes. All sutures were left to dry for 11 days before being tested to failure using an Instron 3367 tensile testing machine. Testing revealed significant differences in failure load, ultimate tensile stress, and Young's modulus between suture types (P

Background: Shoulder replacement is an increasingly common treatment for end-stage degenerative shoulder conditions. Some shoulder replacements are unsuccessful and additional operations might be required. It is important for patients and clinicians to know how long shoulder replacements last and how effectively they reduce pain and improve function. This study aims to determine the longevity and long-term efficacy of shoulder replacements. Methods: in this systematic review and meta-analysis, we searched MEDLINE and Embase from their inception to Sept 24, 2019, for case series and registry data reporting 10-year or longer survival of total shoulder replacements, humeral hemiarthroplasties, and reverse total shoulder replacements of a specific brand of implant. Survival, implant, and patient-reported outcome measures data were extracted. The primary outcome was implant survival. We reviewed and analysed national joint replacement registries separately. We weighted each series by SE and calculated a pooled survival estimate at years 10, 15, and 20. For patient-reported outcome measures we pooled the standardised mean difference at 10 years. This study is registered with PROSPERO, CRD42019140221. Findings: 927 non-duplicate articles were identified by our search, nine articles (reporting ten series) were eligible for analysis of survival and six articles were eligible for analysis of patient reported outcomes. The ten series reported all-cause survival of 529 total shoulder replacements and 364 humeral hemiarthroplasties; no series for reverse total shoulder replacement met the inclusion criteria. The estimated 10-year survival for total shoulder replacement was 94·6% (95% CI 93·6–97·6) and humeral hemiarthroplasties was 90·4% (87·0–94·0). A single registry contributed 7651 total shoulder replacements, 1395 humeral hemiarthroplasties, and 7953 reverse total shoulder replacements. The pooled registry 10-year survival was 92·0% (95% CI 91·0–93·0) for total shoulder replacement, 85·5% (83·3–87·7) for humeral hemiarthroplasties, and 94·4% (93·4–95·7) for patients with osteoarthritis who had reverse total shoulder replacement and 93·6% (91·1–95·8) for patients with rotator cuff arthropathy who had reverse total shoulder replacement. Pooled 10-year patient-reported outcome measures showed a substantial improvement from baseline scores, with a standardised mean difference of 2·13 (95% CI 1·93–2·34). Interpretation: Our data show that approximately 90% of shoulder replacements last for longer than 10 years and patient-reported benefits are sustained. Our findings will be of use to surgeons and patients in the informed consent process and to health-care providers for resource planning. Funding: the National Institute for Health Research, the National Joint Registry for England, Wales, Northern Ireland, and Isle of Man, and the Royal College of Surgeons of England.

Abstract
Background
The impact of comorbidity on the risk of revision in patients undergoing Total Knee arthroplasty (TKA) and Total Hip Arthroplasty (THA) is not currently well known. The aim of this study was to analyze the impact of comorbidity on the risk of revision in TKA and THA.

Methods
Patients recorded in the Catalan Arthroplasty Register (RACat) between 01/01/2005 and 31/12/2016 undergoing TKA (n = 49,701) and THA (n = 17,923) caused by osteoarthritis were included. As main explanatory factors, comorbidity burden was assessed by the Elixhauser index, categorized, and specific comorbidities from the index were taken into account. Descriptive analyses for comorbidity burden and specific conditions were done. Additionally, incidence at 1 and 5 years’ follow-up was calculated, and adjusted Competing Risks models were fitted.

Results
A higher incidence of revision was observed when the number of comorbidities was high, both at 1 and 5 years for THA, but only at 1 year for TKA. of the specific conditions, only obesity was related to the incidence of revision at 1 year in both joints, and at 5 years in TKA. The risk of revision was related to deficiency anemia and liver diseases in TKA, while in THA, it was related to peripheral vascular disorders, metastatic cancer and psychoses.

Conclusions
Different conditions, depending on the joint, might be related to higher revision rates. This information could be relevant for clinical decision-making, patient-specific information and improving the results of both TKA and THA.

Background the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (740%) had emergency surgery and 280 (248%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (261%) patients. 30-day mortality was 238% (268 of 1128). Pulmonary complications occurred in 577 (512%) of 1128 patients; 30-day mortality in these patients was 380% (219 of 577), accounting for 817% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 175 [95% CI 128-240], p

Introduction: Pain maps can help quantify the distribution of pain but are not commonly used in shoulder pathology. This prospective study aims to quantify severity, type and distribution of pain associated with common shoulder pathologies using patient derived pain maps. Material and Methods: 219 patients with 5 common shoulder pathologies were prospectively recruited with diagnosis confirmed definitively at time of procedure. Patients completed maps for nociceptive pain and abnormal sensation. Visual Analogue Score and a validated neuropathic pain questionnaire (painDetect) were completed. Maps were generated with images stacked and overlaid using an FFT based image algorithm to generate pathology specific heat maps. Results: Neuropathic pain was likely in 20% of all patients based on painDetectscores. Abnormal sensation was present overall in 49.3%. 16.1% experienced symptoms below the elbow and 11.6% in the hand. Frozen shoulder appears to have the highest frequency of distal limb symptoms. Conclusion: This study provides a clear guide to the distribution and nature of pain arising from procedure confirmed common shoulder conditions. We have demonstrated that neuropathic pain is prevalent in common shoulder pathologies and may spread as far as the hand. Therefore, pain in this distribution should not be dismissed as cervical as this will lead to a delay in the treatment of the shoulder pathology.

© 2019, the Author(s). Background: Lateral elbow tendinopathy (LET) is a common condition affecting adults. Although a lack of treatment consensus continues to prompt numerous effectiveness studies, there is a paucity of clear guidance on the choice of outcome measure. Our aim was to undertake a standardised evaluation of the available clinical rating systems that report patient-centred outcomes in LET. Methods: a systematic review of studies reporting the development, assessment of metric properties and/or use of instruments aiming to quantify LET-specific patient-centred outcome measures was conducted in MEDLINE, Embase and CINAHL (inception-2017) adhering to PRISMA guidance. The evidence for each instrument was independently assessed by two reviewers using the standardised evaluating measures of patient-reported outcomes (EMPRO) method evaluating overall and attribute-specific instrument performance (metric properties and usability). EMPRO scores > 50/100 were considered indicative of high performance. Results: Out of 7261 references, we identified 105 articles reporting on 15 instruments for EMPRO analysis. Median performance score was 41.6 (range 21.6–72.5), with four instruments meeting high-performance criteria: quick Disabilities of the Arm Shoulder and Hand score (qDASH) (72.5), DASH (66.9), Oxford Elbow Score (OES) (66.6) and Patient-Rated Tennis Elbow Evaluation (PRTEE) (57.0). One hundred seventy-nine articles reported instrument use internationally with DASH as the most frequent (29.7% articles) followed by PRTEE (25.6%), MEPS (15.1%) and qDASH (8.1%). The correlation between frequency of use and performance was r = 0.35 (95%CI − 0.11; 0.83). Conclusions: This is the first study to provide standardised guidance on the choice of measures for LET. A large number of clinical rating systems are both available and being used for patients with LETs. Robust evidence is available for four measures, the DASH, QDASH, PRTEE and OES. The use of instruments in the literature is only in part explained by instrument performance.

PURPOSE: 1) to systematically review the available scientific literature regarding specific instruments developed and/or tested in a Spanish population, to assess these PROMs in hip arthroplasty; 2) to carry out a standardized assessment of their measurement properties; and 3) to identify the best tools for use in Spain in an arthroplasty registry context. METHODS: a systematic review of PubMed/MEDLINE and EMBASE and CINHAL was done. Furthermore, a standardized assessment of the questionnaires identified using the Evaluating the Measurement of Patient-Reported Outcomes (EMPRO) tool was performed. All developments, validation and studies aiming to assess the measurement properties of PROMs in hip arthroplasty in the Spanish population were included. Data from the questionnaires on metric properties was taken into account to identify the best candidates for inclusion in a register. RESULTS: a total of 853 documents were found. After screening title and abstract, 13 full text documents were reviewed and 8 questionnaires adapted and validated to assess some of the aspects of hip arthroplasty in the Spanish population were identified. After the EMPRO assessment, 4 questionnaires showed suitable properties (WOMAC, OAKHQOL, mini-OAKHQOL and PFH). CONCLUSIONS: in Spain, there are a few suitable hip-specific questionnaires currently available to assess PROMs in hip arthroplasty surgery. Some of the more widely used questionnaires, like the OHS and HOOS, have not been validated in the Spanish population until now. Identified tools are suitable for use in a clinical context, however their use in an arthroplasty register is more questionable due to the lack of validation studies of the widely used tools in other registers.

BACKGROUND: the volume of arthroplasties performed in a hospital by year has an influence on the outcomes of total knee arthroplasty (TKA) and unicompartmental knee arthroplasty (UKA). The aims of this study are (1) to evaluate and compare the risk of revision and mortality of TKA and UKA and (2) to assess whether hospital volume is related to differences in revision risk and mortality. METHODS: all individuals recorded in the Catalan Arthroplasty Register between 1/1/2005 and 31/12/2016, diagnosed with osteoarthritis, undergoing cemented TKA and UKA were included. A propensity score matching method was used to obtain comparable cohorts, including 2374 matched prostheses overall. Hospital volume was considered as a dichotomous variable (lower/higher). Descriptive analyses were done before and after matching. Risks of revision and mortality at 30 days, 90 days, 1, 3, and 5 years were calculated and competing risks models and Cox models were fitted. RESULTS: for the population as a whole, higher risk of revision (sub-hazard ratio, 1.98; 95% confidence interval, 1.25-3.17) was found in UKA than in TKA but higher mortality was not. Considering the volume groups, significantly higher risk of revision in UKA than TKA was found in the lower-volume group only (sub-hazard ratio, 1.95; 95% confidence interval, 1.11-3.44). No differences in mortality between TKA and UKA were found in either group. CONCLUSION: Mortality and revision rates after TKA and UKA at higher-volume hospitals are similar. UKAs performed at lower-volume hospitals have higher revision rates. Volume-dependent specialization thus might help to reduce revision and mortality after surgery.

Background: the triceps-on approach for total elbow arthroplasty has gained popularity due to the theoretical benefit of preserving the extensor mechanism. However, there is concern that the exposure may be reduced in comparison to a triceps-off approach and may affect the implant alignment achieved. Method: Total elbow arthroplasties were implanted in 18 randomised, paired cadaveric elbows using the triceps-on or triceps-off approach. The bones were dissected out and the position of the implants measured relative to anatomical landmarks. The flexion/extension and varus/valgus angles, and the distance of centre of rotation from the anatomic centre of rotation in the sagittal plane for both components were obtained as well as the humeral component rotation relative to the transepicondylar axis. Results: all humeral components were positioned in external rotation and all ulna components were placed in flexion. Seven components were positioned greater than 5° away from the ideal in one measurement, with no significant difference between the two approach groups. Discussion: This unique study showed no significant difference in the alignment of the implants between the two approaches. These results support the theory that the triceps-on approach does not result in larger alignment errors in component positioning when performing total elbow arthroplasty.

The volume of total hip (THA) and knee arthroplasties (TKA) performed in a hospital per year could be an influential factor on the revision of these procedures. The aims of this study were: to obtain comparable cohorts in higher- and lower-volume hospitals; and to assess the association between the hospital volume and the incidence of revision. Data from patients undergoing THA and TKA caused by osteoarthritis and recorded in the Catalan Arthroplasty Register (RACat) between January 2005 and December 2016 were used. The main explanatory variable was hospital volume by year (higher/lower). The cut-off point was fixed, based on previous research, at 50 THA and 125 TKA procedures/year. To obtain comparable populations, a propensity-score matching method (1:1) was used. Patient characteristics prior to and after matching were compared. To assess differences by volume, subhazard ratios (SHRs) from competing risks models were obtained. After matching, 13,772 THA and 36,316 TKA patients remained in the study. Prior to matching, in both joints, significant differences in all confounders were observed between volume groups. After matching, none of them remained significant. Both in THA and TKA, a higher risk of revision in higher-volume hospitals was observed (THA SHR: 1.25, 95%CI: 1.02-1.53; and TKA SHR: 1.29, 95%CI: 1.16-1.44). Unlike other contexts, currently in Catalonia, higher-volume hospitals have a greater risk of revision than lower-volume hospitals. Further research could be valuable to define context-dependent measures to reduce the incidence of revision.

Background: the surgical treatment of recurrent shoulder instability has evolved in recent years to include a variety of soft tissue and bone block procedures, undertaken with either an open or arthroscopic approach. Although the utilization of such techniques has rapidly expanded, the associated risk of complications remains poorly defined. This information is vital for clinical decision making and patient counseling. Purpose: to quantify the complication rate associated with all types of surgery for anterior glenohumeral joint dislocation. Study Design: Systematic review. Methods: a systematic search was undertaken of studies reporting complications from anterior shoulder stabilization surgery. Inclusion criteria were studies published in English between 2000 and 2017 with a minimum 2-year follow-up. Methodological quality of the included studies was assessed with the Methodological Index for Non-Randomized Studies criteria. Complication rates for all undesirable events contributing to the patient outcome were extracted and cumulative rates calculated. Results: Out of 1942 references, 56 studies were included, totaling 4362 procedures among 4336 patients. Arthroscopic soft tissue repair had a complication rate of 1.6% (n = 2805). When repair was combined with arthroscopic remplissage, the rate was 0.5% (n = 219). Open soft tissue repair had a complication rate of 6.2% (n = 219) and open labral repair with remplissage, a rate of 2.3% (n = 79). An open bone block procedure had a complication rate of 7.2% (n = 573) and an arthroscopic bone block procedure, a rate of 13.6% (n = 163). Conclusion: This large systematic review demonstrates the overall complication rates (not purely recurrence rates) in modern shoulder stabilization surgery. With the growing interest in bone block stabilization procedures, including those performed arthroscopically, surgeons should be aware of the 10-fold increase in complications for these procedures over soft tissue arthroscopic surgery and counsel their patients accordingly.

A systematic review of the complications of contemporary total elbow arthroplasty, Phoebe Parker, Nicholas D Furness, Jonathan P Evans, William J White, Christopher D Smith; Shoulder & Elbow, 2019 DOI: 10.1177/ 1758573219834934. The authors of the article have brought to the attention of the Journal Editor that the data analysis for the systematic review included two papers that did not meet the inclusion criteria, making the systematic review factually incorrect. The authors apologise for this error. The Journal Editor welcomes the authors to submit to the journal a substantially new manuscript for consideration which will be subject to the journal’s standard peer review processes.

The effectiveness and safety of shoulder arthroplasties in the general context of a Spanish patient population remains unclear. The aim of this study was to ascertain both the effectiveness and safety of primary shoulder arthroplasties and the prosthesis types used in Spain. A systematic review of all the available literature evaluating the effectiveness and safety of primary shoulder arthroplasties in Spain was performed. A narrative synthesis was performed, and evidence tables were created in four dimensions: study design, arthroplasty characteristics, safety, and effectiveness. Orthopaedic Data Evaluation Panel (ODEP) scores were used to evaluate prosthesis types. Twenty-one studies were selected that included a total of 1293 arthroplasties. The most common indication was fractures, while the prosthesis most frequently used was the Delta Xtend (ODEP 10A). The most common complication was scapular notching. Prosthesis revision rate was approximately 6% for follow-ups between 12 and 79 months. In addition, significant improvements were observed in the Constant-Murley test score after the intervention. Currently in Spain, shoulder arthroplasty can be considered a safe and effective procedure with functional recovery and pain reduction for eligible patients with humeral fracture, rotator cuff arthropathy, fracture sequelae and malunion of the proximal humerus, and degenerative disease. Future longitudinal research and population-based studies could serve to confirm these results and identify points of improvement.

Shoulder arthritis is a painful and functionally limiting condition. Importantly, the overarching diagnosis of shoulder arthritis encompasses a cascade of pathologies affecting the bony and soft tissue structures of the shoulder. Although many surgical and non-surgical management options are available, effective utilization of these treatments is dependent upon careful diagnosis and consideration of the complex anatomy of the glenohumeral joint. This review considers what is known about this increasingly common condition and the spectrum of treatments available.

BACKGROUND: Arthroscopic capsular release (ACR) and hydrodilatation (HD) have been developed for the management of frozen shoulder refractory to conservative treatment. To date no randomized trial has directly compared the efficacy of both interventions. The aim of this trial was to determine whether the Oxford Shoulder Score (OSS) differs between patients with frozen shoulder randomized to treatment with ACR or HD. METHODS: Patients presenting with severe idiopathic frozen shoulder deemed suitable for surgical intervention by a consultant shoulder surgeon were randomized to ACR or HD. The primary outcome measure was OSS at 6 months, with secondary outcomes measures of the EuroQol-5D visual analog scale, external rotation, complications, and crossover rate also recorded. RESULTS: Between June 2013 and December 2016, 50 patients were randomized to HD or ACR. The average age of the HD and ACR cohorts was 55.2 and 52.6 years, respectively (P = .36). At 6 months after the intervention, 20 patients were available for follow-up in the HD cohort and 19 in the ACR cohort. Both groups demonstrated significant improvements in OSS from baseline, but the OSS was significantly higher in the ACR cohort than the HD cohort (43.8 vs. 38.5, P = .023). The OSS was noted to improve rapidly after the intervention, with 75% of improvement in OSS noted at 6 weeks after surgery in both groups. CONCLUSIONS: Patients randomized to ACR reported a significantly higher OSS at 6 months than those randomized to HD. Both groups, however, showed a significant improvement.

© 2018 Journal of Shoulder and Elbow Surgery Board of Trustees Background: Clinical rating systems are used as outcome measures in clinical trials and attempt to gauge the patient’s view of his or her own health. The choice of clinical rating system should be supported by its performance against established quality standards. Methods: a search strategy was developed to identify all studies that reported the use of clinical rating systems in the elbow literature. The strategy was run from inception in Medline Embase and CINHAL. Data extraction identified the date of publication, country of data collection, pathology assessed, and the outcome measure used. Results: We identified 980 studies that reported clinical rating system use. Seventy-two separate rating systems were identified. Forty-one percent of studies used ≥2 separate measures. Overall, 54% of studies used the Mayo Elbow Performance Score (MEPS). For arthroplasty, 82% used MEPS, 17% used Disabilities of Arm, Shoulder and Hand (DASH), and 7% used QuickDASH. For trauma, 66.7% used MEPS, 32% used DASH, and 23% used the Morrey Score. For tendinopathy, 31% used DASH, 23% used Patient-Rated Tennis Elbow Evaluation (PRTEE), and 13% used MEPS. Over time, there was an increased proportional use of the MEPS, DASH, QuickDASH, PRTEE, and the Oxford Elbow Score. Conclusions: This study identified a wide choice and usage of clinical rating systems in the elbow literature. Numerous studies reported measures without a history of either a specific pathology or cross-cultural validation. Interpretability and comparison of outcomes is dependent on the unification of outcome measure choice. This was not demonstrated currently.

INTRODUCTION There has been a significant increase in the implantation of reverse shoulder replacements over anatomical shoulder replacements in the past five years. Few comparative data exist comparing early complication rates and learning curves. This study aimed to evaluate the early complication rates and learning curves of a single surgeon series of anatomical and reverse shoulder replacements over the first five years of independent practice. MATERIALS AND METHODS the first 100 anatomical and 100 reverse shoulder replacements performed between July 2011 and July 2016 were reviewed to identify early complications. Cumulative sum plots were used to analyse the learning-curve effect. RESULTS Early complications were noted in 4 anatomical and 17 reverse shoulder replacements. One of the anatomical and ten of the reverse shoulder replacements required a return to theatre within three months. The early complication rates were observed to be significantly higher in the reverse shoulder replacement group compared with the anatomical shoulder replacement group (odds ratio 4.9; 95% confidence interval 1.6-15.2, P 1/4 0.057). An inflection point on the anatomical shoulder replacement cumulative sum plot suggestive of a trend to consistent performance was reached at 16 cases. No inflection point was observed on the reverse shoulder replacement cohort. CONCLUSIONS We observed a significantly higher early complication rate within the reverse shoulder replacement cohort, with a tenfold increase in early reoperations. In comparison to the trend seen after 16 cases for anatomical shoulder replacement, no trend was seen in the reverse shoulder replacement cohort. This either reflects the higher complication rate seen in reverse shoulder replacement or that the learning curve extends beyond 100 cases, highlighting the need for extended performance monitoring.

Aim: Generic patient-reported outcome measures (PROMs) allow comparison of health-related quality of life across populations and pathologies. For these comparisons to be valid, the PROM must be responsive; the score must change when the patient’s quality of life changes. This study aims to assess the responsiveness of the EQ-5D-three level (3L) in elective shoulder surgery. Methods: Pre- and post-operative EQ-5D-3L and Oxford Shoulder Scores (OSS) were prospectively collected across a range of 204 elective shoulder surgeries. Internal responsiveness was assessed through significance testing of mean change scores and standardized response means (SRMs). External responsiveness of the EQ-5D-3L was assessed against the minimal clinically important difference in OSS, using receiver operating characteristic curve and change score correlation. Results: Both EQ-5D-3L and OSS scores improved significantly over time ( p < 0.05). The SRM for the EQ-5D was 1.27 (95% CI 1.14–1.41) and for OSS 2.36 (2.22–2.52). Area under the curve for EQ-5D was 0.49. Only a weak correlation was found between EQ-5D and OSS change scores ( r = 0.21). Discussion: the EQ-5D-3L is adequately internally responsive to change following elective shoulder surgery but is unable to differentiate patients demonstrating minimal clinically important change. The EQ-5D therefore only partially reflects patient experience.

The interest in patient-reported outcome measures (PROMs) continues to increase as recognition of their potential utility rises in an effort to make health systems more patient-centered. The US National Institutes of Health (NIH) Patient-Reported Outcomes Measurement Information System® (PROMIS®) has used state of the art psychometric and statistical techniques to create a universal PROMs language, with potential application across the whole spectrum of health conditions, languages, and geographic locations. PROMIS offers a versatile platform where specific health domains are assessed using both standardized short forms and computerized adaptive tests, which are automatically tailored to individual patients. The scores of each health domain or a standardized profile of multiple domains are all scored on a common metric scale. PROMIS is increasingly recognized as the international gold standard for patient-centered assessment, although the use of these tools in the UK is limited. In this review, the developmental methodology of the PROMIS is described with discussion of its relevant strengths and limitations for use in the UK. We provide a case study of the largest application of the PROMIS tools in the UK as an example of straightforward integration into health-care research. Barriers to the uptake of PROMIS in the UK include the technology requirement, measurement tradition, and lack of a clear understanding of its benefits, and although potential stakeholders should cautiously consider its use, its impressive potential and increasing international utilization should be recognized.

BACKGROUND: Injections into the tendinous portion of the common extensor origin are a common intervention in the treatment of Lateral Elbow Tendinopathy (LET). Clinical trials report a heterogeneous selection of injectate volumes and delivery techniques, with systematic reviews finding no clear consensus. The aim of this study was to assess the intratendinous distribution and surrounding tissue contamination of ultrasound-guided injections into the Common Extensor Tendon (CET) of the elbow. METHODS: Twenty cadaveric elbows were injected by a Consultant Radiologist under Ultrasound guidance. Elbows were randomised to equal groups of 1 or 3 mls of methylene blue injection, delivered using single shot or fenestrated techniques. Following injection, each cadaver underwent a dry arthroscopy and dissection of superficial tissues. The CET was excised, set and divided into 1 mm sections using microtome. Each slice was photographed and analysed to assess spread and pixel density of injectate in four colour graduations. The cross-sectional area of distribution was calculated and compared between groups. RESULTS: in all 20 cadaveric samples, contamination of the joint was noted on arthroscopy and dissection. Injectate spread through over 97% of the cross-sectional area. No differences were found in intratendinous spread of injectate between differing volumes or techniques. CONCLUSION: This study found that commonly used injection volumes and techniques distribute widely throughout cadaveric CETs. There was no improvement when the volume was increased from 1 to 3 mls or between single shot of fenestrated injection techniques. It should be noted that joint contamination using these techniques and volumes may be inevitable.

Aim: to determine whether a mechanical, high-frequency vibration device (Tenease™) can improve pain and function for the treatment of tennis elbow (TE), compared with standard treatment. Methods: Adults presenting to an elbow clinic with a clinical diagnosis of TE were randomized to standard treatment with physiotherapy, activity modification and analgesia or standard treatment plus Tenease therapy. Tenease therapy consisted of a 6-week period of treatment using the Tenease device with three 10-min episodes each day. The primary outcome measure was the quick Disabilities of the Arm, Shoulder and Hand score at 6 months, with scores also taken at 6 weeks. Secondary outcome measures were the Patient Rated Tennis Elbow Evaluation Score and EuroQol 5-Dimension Visual Analogue Scale at the same time points. Results: Fifty-four patients were recruited into the study. Following randomization and initial dropout, 18 patients were included in the standard group and 27 in the Tenease group. Both groups reported improvements in primary outcome measure scores. The control group had a mean score of 44.3 (standard deviation (SD) = 18.8) at baseline, which dropped to 31.2 (SD = 17.2) at 6 months (p = 0.002). The Tenease group had a mean score of 43.2 (SD = 22.7) at baseline, which dropped to 23.4 (SD = 15.0) at 6 months (p = 0.064). Similar improvements were seen in secondary outcome measures with none reaching statistical significance. There were no statistically significant differences seen between the primary outcome scores at 6 weeks (p = 0.9) or 6 months (p = 0.5). No complications were noted in either group. Conclusions: Vibration therapy did not result in any statistically significant improvement in functional outcome scores compared to standard treatment for TE. It is important to note that this was a relatively small cohort and a high dropout rate was observed.

Our aim was to investigate the prevalence of Propionibacterium (P.) acnes in the subcutaneous fat and capsule of patients undergoing shoulder surgery for frozen shoulder or instability. Patients and Methods a total of 46 patients undergoing either an arthroscopic capsular release or stabilisation had biopsies taken from the subcutaneous fat and capsule of the shoulder at the time of surgery. These samples were sent for culture in enrichment, and also for Nucleic Acid Amplification testing. The prevalence of P. acnes and other microbes was recorded. Fisher's exact test of binary variables was used to calculate the association with significance set at p < 0.05. Assessment of influence of independent variables including a pre-operative glenohumeral injection, fat colonisation and gender, was undertaken using binary linear regression. Results a total of 25 patients (53%) had P. acnes in one or more tissue samples and 35 (74%) had other bacterial species. The same microbe was found in the subcutaneous fat and the capsule in 13 patients (28%). There was no statistically significant association between the surgical pathology and capsular colonisation with P. acnes (p = 0.18) or mixed identified bacterial species (p = 0.77). Male gender was significantly associated with an increased capsular colonisation of P. acnes (odds ratio (OR) 12.38, 95% confidence interval (CI) 1.43 to 106.77, p = 0.02). A pre-operative glenohumeral injection was significantly associated with capsular P. acnes colonisation (OR 5.63, 95% CI 1.07 to 29.61, p = 0.04. Positive fat colonisation with P. acnes was significantly associated with capsular P. acnes (OR 363, 95% CI 20.90 to 6304.19, p < 0.01). Regression models pseudo R2 found fat colonisation with P. acnes to explain 70% of the variance of the model. Patients who had a pre-operative glenohumeral injection who were found intra-operatively to have fat colonisation with P. acnes had a statistically significant association with colonisation of their capsule with P. acnes (OR 165, 95% CI 13.51 to 2015.24, p < 0.01). Conclusion These results show a statistically significant association between subcutaneous skin P. acnes culture and P. acnes capsular culture, especially when the patient has undergone a previous injection. The results refute the hypothesis that P. acnes causes frozen shoulder.

Frozen shoulder is a common disease which causes significant morbidity. Despite over a hundred years of treating this condition the definition, diagnosis, pathology and most efficacious treatments are still largely unclear. This systematic review of current treatments for frozen shoulder reviews the evidence base behind physiotherapy, both oral and intra articular steroid, hydrodilatation, manipulation under anaesthesia and arthroscopic capsular release. Key areas in which future research could be directed are identified, in particular with regard to the increasing role of arthroscopic capsular release as a treatment.