Swiss-wide multicentre evaluation and prediction of core outcomes in arthroscopic rotator cuff repair: protocol for the ARCR_Pred cohort study.

INTRODUCTION: In the field of arthroscopic rotator cuff repair (ARCR), reporting standards of published studies differ dramatically, notably concerning adverse events (AEs). In addition, prognostic studies are overall methodologically poor, based on small data sets and explore only limited numbers of influencing factors. We aim to develop prognostic models for individual ARCR patients, primarily for the patient-reported assessment of shoulder function (Oxford Shoulder Score (OSS)) and the occurrence of shoulder stiffness 6 months after surgery. We also aim to evaluate the use of a consensus core event set (CES) for AEs and validate a severity classification for these events, considering the patient's perspective. METHODS AND ANALYSIS: A cohort of 970 primary ARCR patients will be prospectively documented from several Swiss and German orthopaedic clinics up to 24 months postoperatively. Patient clinical examinations at 6 and 12 months will include shoulder range of motion and strength (Constant Score). Tendon repair integrity status will be assessed by ultrasound at 12 months. Patient-reported questionnaires at 6, 12 and 24 months will determine functional scores (subjective shoulder value, OSS), anxiety and depression scores, working status, sports activities, and quality of life (European Quality of Life 5 Dimensions 5 Level questionnaire). AEs will be documented according to a CES. Prognostic models will be developed using an internationally supported regression methodology. Multiple prognostic factors, including patient baseline demographics, psychological, socioeconomic and clinical factors, rotator cuff integrity, concomitant local findings, and (post)operative management factors, will be investigated. ETHICS AND DISSEMINATION: This project contributes to the development of personalised risk predictions for supporting the surgical decision process in ARCR. The consensus CES may become an international reference for the reporting of complications in clinical studies and registries. Ethical approval was obtained on 1 April 2020 from the lead ethics committee (EKNZ, Basel, Switzerland; ID: 2019-02076). All participants will provide informed written consent before enrolment in the study. TRIAL REGISTRATION NUMBER: NCT04321005. PROTOCOL VERSION: Version 2 (13 December 2019).

Subcutaneous tissue disinfection significantly reduces Cutibacterium acnes burden in primary open shoulder surgery.

BACKGROUND: Cutibacterium acnes is one of the major pathogens responsible for infection after shoulder surgery. Surgical dissection of the dermis may expose C acnes from sebum-producing hair follicles. Because of contact with the surgeon's gloves and instruments, further spread occurs throughout the surgical field. The purpose of this study was to determine whether subcutaneous tissue disinfection could reduce the C acnes culture rate in primary open shoulder surgery. METHODS: All patients eligible for primary open shoulder surgery by a deltopectoral approach were prospectively enrolled in our 2-arm, randomized, single-blinded clinical trial. In all patients, a skin swab of the operative field was taken prior to standard surgical skin preparation. After exposure of the deltoid fascia, the disinfection group received an additional preparation of the subcutaneous layer with povidone-iodine solution. Once the proximal humerus was completely exposed, 5 swabs from different sites were taken for microbiological examination according to a strict specimen collection protocol. All cultures were incubated in aerobic and anaerobic conditions for 14 days. RESULTS: Between February and December 2019, 108 patients were enrolled in the 2 groups: treatment (n = 70) and control (n = 38). The 2 groups did not show any significant difference in terms of sex, age, body mass index, or occurrence of diabetes. The subcutaneous disinfection protocol significantly reduced the positive culture rate of the operating field for all germs combined (P = .036) and specifically for C acnes (P = .013). The reduction of positive swabs for C acnes was significant for the surgeon's gloves (P = .041), as well as the retractors (P = .007). CONCLUSION: Disinfection of the subcutaneous tissue significantly reduced the C acnes culture rate during primary open shoulder surgery. We highly recommend this simple step as an adjunct to the current surgical practice to limit iatrogenic contamination of the surgical field. Future studies may observe a reduction in postoperative shoulder infection owing to this practice.

Muscle fat content in the intact infraspinatus muscle correlates with age and BMI, but not critical shoulder angle.

PURPOSE: Muscle fat content of the rotator cuff increases after a tear. In the healthy rotator cuff, the influence of age, body mass index (BMI) and critical shoulder angle (CSA) on muscle fat content is unknown. The primary aim was to correlate muscle fat content with age, BMI and CSA. The secondary aims were (1) to correlate muscle fat content in the entire muscle and slice Y (most lateral sagittal slice with scapular spine) and (2) assessed the reliability for CSA measurement in MRI. METHODS: In 26 healthy shoulders (17 subjects), aged 40-65 years, BMI 20-35 kg/m2, Goutallier grade 0, Dixon MRI was applied. The CSA was > 35° in 14 shoulders and < 30° in 12 shoulders. Muscle fat content was calculated from Dixon MRI. RESULTS: Infraspinatus muscle fat content correlates moderately with age (r = 0.553; p = 0.003) and BMI (r = 0.517; p = 0.007). Supraspinatus muscle fat content does not correlate with age (r = 0.363, p = 0.069) and BMI (r = 0.342, p = 0.087). No correlation between CSA and muscle fat content was found. Muscle fat content measurement in the entire muscle correlates strongly with measurement in slice Y (intraclass correlation coefficient supraspinatus muscle: 0.757; infraspinatus muscle: 0.794). CSA intermethod analysis between radiography and MR images shows very high reliability (intraclass correlation coefficient > 0.9) and no systematical deviation in Bland-Altman analysis. CONCLUSION: Muscle fat content in the healthy infraspinatus muscle does correlate with age and BMI, but not with the CSA. Muscle fat content measurement in the rotator cuff using Dixon MRI showed a high reliability between slice Y and the entire muscle. LEVEL OF EVIDENCE: III.

Biomechanical analysis of the humeral head coverage, glenoid inclination and acromio-glenoidal height as isolated components of the critical shoulder angle in a dynamic cadaveric shoulder model.

BACKGROUND: The Critical Shoulder Angle was introduced as a combined radiographic surrogate parameter reflecting the influence of the morphological characteristics of the scapula on the development of degenerative shoulder disease such as rotator cuff tears and osteoarthritis. Although, glenoid inclination and lateral extension of the acromion were studied in biomechanical models separately, no investigation included all three individual parameters that determine the Critical Shoulder Angle: glenoid inclination, acromial coverage and acromial height in one cadaveric study protocol. METHODS: Three proximal humerus cadavers were attached to a robotic shoulder simulator which allowed for independent change of either lateral acromial coverage, glenoid inclination or acromial height. Combined dynamic scapula-thoracic and glenohumeral abduction up to 60° with different Critical Shoulder Angle configurations was performed and muscle forces as well as joint reaction forces were recorded. FINDINGS: All three components had an effect on either muscle forces and or joint reaction forces. While glenoid inclination showed the highest impact on joint stability with increasing upward-tilting causing cranial subluxation, changing of the lateral acromial coverage or acromial height had less influence on stability but showed significant alteration of joint reaction forces. INTERPRETATION: All three components of the Critical Shoulder Angle, glenoid inclination, lateral acromial extension and acromial height showed independent biomechanical effects when changed isolated. However, glenoid inclination seems to have the largest impact regarding joint stability.

Snow avalanche deaths in Switzerland from 1995 to 2014-Results of a nation-wide linkage study.

OBJECTIVES: More than 20 people die each year in snow avalanches in Switzerland. Previous studies have primarily described these victims, but were not population based. We investigated sociodemographic factors for avalanche mortality between 1995 and 2014 in the entire Swiss resident population. DESIGN AND METHODS: Within the Swiss National Cohort we ascertained avalanche deaths by anonymous data linkage with the avalanche accident database at the Swiss WSL Institute of Snow and Avalanche Research SLF. We calculated incidence rates, by dividing the number of deaths from avalanches by the number of person-years, and hazard ratios (HRs) for sociodemographic and economic characteristics using Cox proportional hazard models. RESULTS: The data linkage yielded 250 deaths from avalanche within the SNC population for the 20 years 1995 to 2014. The median distance between the place of residence and the place of the event (avalanche) was 61.1 km. Male gender, younger age (15-45 years), Swiss nationality, living in the Alpine regions, higher education, living in the highest socioeconomic quintile of neighbourhoods, being single, and living in a household with one or more children were associated with higher avalanche mortality rates. Furthermore, for younger persons (<40 years) the hazard of dying in an avalanche between 2005 and 2014 was significantly lower than in the years 1995 to 2004 (HR = 0.56, 95%-CI: 0.36-0.85). CONCLUSION: Over a 20-year period in Switzerland, higher rates of dying in an avalanche were observed in men, in younger age groups, and persons with tertiary education, living in the highest socioeconomic quintile of neighbourhoods, and living in an Alpine region. For younger persons (<40 years), the hazard declined during the study period.

[Winter sports†: from an emergency service to a general practitioner's office]. / Sports d'hiver†: d'un service d'urgences à un cabinet de premier recours.

In an alpine region, the winter season has a major impact on the daily practice of both an emergency department and a general practice. During the 2017-2018 season, we have listed the consultations caused by winter sports, whether traumatological or medical. The vast majority are ambulatory. Initial care and follow-up can usually be performed by a primary care physician. In this paper, we will outline the management of the knee and acromioclavicular sprain, two frequent lesions in the winter sports setting.

Dans un canton alpin comme le Valais, la saison d'hiver a un impact important sur la pratique quotidienne aussi bien d'un service d'urgences que d'un cabinet de médecine interne générale. Durant la saison 2017-2018, nous avons répertorié les consultations engendrées par la pratique des sports d'hiver, que leur motif soit traumatologique ou médical. La grande majorité des consultations sont ambulatoires. Leur prise en charge initiale et le suivi peuvent souvent être assurés par un médecin de premier recours. Les grandes lignes de la prise en charge des traumatismes du genou et de l'entorse acromio-claviculaire, lésions parmi les plus fréquentes, seront détaillées dans cet article.

Early complications and recurrence rates after Kirschner wire transfixion in lesser toe surgery: a prospective randomized study.

BACKGROUND: Prolonged percutaneous Kirschner wire transfixion after correction of lesser toe deformities has been associated with an increased rate of complications such as infection, wire breakage or loosening. Currently, the duration of wire transfixion is based on the surgeons' opinion rather than on evidence. We hypothesized that a transfixion time of 3 weeks when compared to 6 weeks would decrease complication rates without an increase in the rate of recurrent deformity. METHODS: We prospectively randomized 52 lesser toes corrected for a moderate hammer- or claw toe deformity by means of resectional arthroplasty of the proximal interphalangeal joint into two groups with 3 and 6 weeks of Kirschner wire transfixion, respectively. Kirschner wire-associated complication rates and incidence of early recurrence of malalignment in a short term followup of three months were assessed. Forty-six toes, 23 in each group, were available for final followup. RESULTS: No statistically significant differences were found in pre- and postoperative total AOFAS scores between the groups. No Kirschner wire associated complications occurred. Recurrent malalignment was more often documented in the group with 3 weeks of transfixion (11 of 23 toes, 47.8%) when compared to 6 weeks (two of 23 toes, 8.7%) at 3 months followup. Interphalangeal joint motion was significantly reduced with prolonged Kirschner wire transfixion, indicating a more stable fibrous union (p = 0.038). CONCLUSION: At short-term followup, Kirschner wire transfixion of 6 weeks as opposed to 3 weeks showed a lower rate of recurrent malalignment without an increase in Kirschner wire associated complications.

A pedicled bone graft from the acromion: an anatomical investigation regarding surgical feasibility.

OBJECTIVE: To investigate the technical feasibility of harvesting a vascularized bone graft from the acromion pedicled on the acromial branch. BACKGROUND: Complex fractures of the proximal humerus may result in partial or total avascular necrosis of the head fragment. Treatment of avascular necrosis of the humeral head is dependent upon the stage of disease as well as the dimension and location of necrosis. In general, the outcome is poor and complete restoration of the shoulder function is rarely attained. Contrary to osteonecrosis of carpal bones (where vascularized bone grafts have been routinely carried out for decades), reports of analogous procedures at the humeral head are anecdotal. METHODS: Based on selective post-mortem computer-tomographic angiography of 5 and the dissection of 30 embalmed human cadaver shoulders, we describe the anatomy of the acromial branch of the thoracoacromial trunk. The main focus was the constancy of its anatomical course, its dimensions and potential use as a nutrient vessel for a pedicled bone graft from the acromion. RESULTS: The course of the acromial branch revealed a constant topographic relationship to anatomical landmarks. Its terminal branches reliably supplied the anterior part of the acromion. The vascularized bone graft could be sufficiently mobilized to allow tension-free transfer to the humeral head as well as to the lateral two-thirds of the clavicle. CONCLUSION: We demonstrated the feasibility of vascularized bone graft harvesting from the acromion. This technique could be a joint-preserving procedure for osteonecrosis of the humeral head or may assist in the revision of a clavicular pseudoarthrosis.

Treatment of periprosthetic femoral fractures of the knee.

PURPOSE: We report a continuous series of periprosthetic femoral fractures after knee arthroplasty treated with a locking plate. We hypothesize that minimally invasive surgery and immediate weight-bearing improve functional recovery. METHODS: From June 2002 to December 2008, 15 patients with 16 fractures were treated. Median age was 81 years. The autonomy level according to the mobility score of Parker and Palmer showed a median of 5 (0-9). Osteosynthesis was performed mainly through a minimally invasive approach using a locking compression plate. The rehabilitation protocol consisted of immediate mobilization and, whenever possible, immediate unrestricted weight-bearing. RESULTS: Five patients died during follow-up, more than 1 year after osteosynthesis. Their results were included. Autonomy and mobility were preserved with a median postoperative score of 4 (0-9) according to Parker and Palmer. The consolidation rate was 93.8%, which was obtained within 10 weeks. There were no mechanical or infectious complications. Fourteen cases were treated with minimally invasive surgery without fracture exposition; the remaining 2 required a slightly more extended approach. Full weight-bearing occurred 10 times; 20-kg partial weight-bearing was advised twice; and on 4 occasions, no weight-bearing was allowed for 6 weeks. CONCLUSION: Osteosynthesis with a minimally invasive bridge-plating technique is effective in the treatment of periprosthetic, distal femoral fractures without component loosening. Immediate full weight-bearing is possible if certain rules are respected. The surgical management presented herein is beneficial for these challenging fractures, and it may help reduce the complication rate and improve functional outcome.