Automatic quantification of scapular and glenoid morphology from CT scans using deep learning.

OBJECTIVES: To develop and validate an open-source deep learning model for automatically quantifying scapular and glenoid morphology using CT images of normal subjects and patients with glenohumeral osteoarthritis. MATERIALS AND METHODS: First, we used deep learning to segment the scapula from CT images and then to identify the location of 13 landmarks on the scapula, 9 of them to establish a coordinate system unaffected by osteoarthritis-related changes, and the remaining 4 landmarks on the glenoid cavity to determine the glenoid size and orientation in this scapular coordinate system. The glenoid version, glenoid inclination, critical shoulder angle, glenopolar angle, glenoid height, and glenoid width were subsequently measured in this coordinate system. A 5-fold cross-validation was performed to evaluate the performance of this approach on 60 normal/non-osteoarthritic and 56 pathological/osteoarthritic scapulae. RESULTS: The Dice similarity coefficient between manual and automatic scapular segmentations exceeded 0.97 in both normal and pathological cases. The average error in automatic scapular and glenoid landmark positioning ranged between 1 and 2.5 mm and was comparable between the automatic method and human raters. The automatic method provided acceptable estimates of glenoid version (R2 = 0.95), glenoid inclination (R2 = 0.93), critical shoulder angle (R2 = 0.95), glenopolar angle (R2 = 0.90), glenoid height (R2 = 0.88) and width (R2 = 0.94). However, a significant difference was found for glenoid inclination between manual and automatic measurements (p < 0.001). CONCLUSIONS: This open-source deep learning model enables the automatic quantification of scapular and glenoid morphology from CT scans of patients with glenohumeral osteoarthritis, with sufficient accuracy for clinical use.

Glenohumeral joint force prediction with deep learning.

Deep learning models (DLM) are efficient replacements for computationally intensive optimization techniques. Musculoskeletal models (MSM) typically involve resource-intensive optimization processes for determining joint and muscle forces. Consequently, DLM could predict MSM results and reduce computational costs. Within the total shoulder arthroplasty (TSA) domain, the glenohumeral joint force represents a critical MSM outcome as it can influence joint function, joint stability, and implant durability. Here, we aimed to employ deep learning techniques to predict both the magnitude and direction of the glenohumeral joint force. To achieve this, 959 virtual subjects were generated using the Markov-Chain Monte-Carlo method, providing patient-specific parameters from an existing clinical registry. A DLM was constructed to predict the glenohumeral joint force components within the scapula coordinate system for the generated subjects with a coefficient of determination of 0.97, 0.98, and 0.98 for the three components of the glenohumeral joint force. The corresponding mean absolute errors were 11.1, 12.2, and 15.0 N, which were about 2% of the maximum glenohumeral joint force. In conclusion, DLM maintains a comparable level of reliability in glenohumeral joint force estimation with MSM, while drastically reducing the computational costs.

Three-dimensional evaluation of the transverse rotator cuff muscle's resultant force angle in relation to scapulohumeral subluxation and glenoid vault morphology in nonpathological shoulders.

BACKGROUND: Static posterior subluxation of the humeral head (SPSH) results in glenohumeral osteoarthritis. Treatment strategies for SPSH with or without resulting osteoarthritis remain challenging. There is growing interest in evaluating the rotator cuff muscle volume, fatty infiltration, or forces in osteoarthritic shoulders with SPSH, mainly due to a possible transverse force imbalance. In nonpathological shoulders, the transverse angle of the rotator cuff muscle's resultant force may be associated with scapulohumeral alignment and glenoid vault morphology, despite an assumed transverse force balance. The purpose of this study was to assess the transverse rotator cuff muscle's resultant force angle (TRFA) and its relationship with the scapulohumeral subluxation index (SHSI) and selected glenoid vault parameters using computer modeling. METHODS: Computed tomography scans of 55 trauma patients (age 31 ± 13 years, 36 males) with nonpathological shoulders were analyzed and all measurements performed in 3-dimension. We placed landmarks manually to determine the humeral head center and the rotator cuff tendon footprints. The contours of the rotator cuff muscle cross-sectional areas were automatically predicted in a plane perpendicular to the scapula. Each rotator cuff muscle was divided into virtual vector fibers with homogeneous density. The resultant force vector direction for each muscle, corresponding to the rotator cuff action line, was calculated by vectorially summing the normalized fiber vectors for each muscle, weighted by the muscle trophic ratio. The resultant force vector was projected on the axial plane, and its angle with the mediolateral scapular axis was used to determine TRFA. The SHSI according to Walch, glenoid version angle (GVA), glenoid anteroposterior offset angle (GOA), glenoid depth, glenoid width, and glenoid radius were also evaluated. RESULTS: The mean values for TRFA, SHSI, GVA, GOA, glenoid depth, glenoid width, and glenoid radius were 7.4 ± 4.5°, 54.3 ± 4.8%, -4.1 ± 4.4°, 5.1 ± 10.8°, 3.3 ± 0.6 mm, 20 ± 2 mm, and 33.6 ± 4.6 mm, respectively. The TRFA correlated strongly with SHSI (R = 0.731, P < .001) and GVA (R = 0.716, P < .001) and moderately with GOA (R = 0.663, P < .001). The SHSI was strongly negatively correlated with GVA (R = -0.813, P < .001) and moderately with GOA (R = -0.552, P < .001). The GVA correlated strongly with GOA (R = 0.768, P < .001). In contrast, TRFA, SHSI, GVA, and GOA did not correlate with glenoid depth, width, or radius. CONCLUSION: Despite an assumed balance in the transverse volume of the rotator cuff muscles in nonpathological shoulders, variations exist regarding the transverse resultant force depending on the SHSI, GVA, and GOA. In healthy/nonosteoarthritic shoulders, an increased glenoid retroversion is associated with a decreased anterior glenoid offset.

Surgical approaches to the capitellum: a comparative anatomic study.

BACKGROUND: Osteochondritis dissecans (OCD) of the humeral capitellum is an important cause of elbow disability in young athletes. Large and unstable lesions sometimes require joint reconstruction with osteochondral autograft. Several approaches have been described to expose the capitellum for the purpose of treating OCD. The posterior anconeus-splitting approach and the lateral approach with or without release of the lateral ligamentous complex are the most frequently used for this indication. The surface accessible by these approaches has not been widely studied. This study compared the extent of the articular surface of the capitellum that could be exposed with the Kocher approach (without ligament release) vs. the posterior anconeus-splitting approach. A secondary outcome was the measurement of any additional area that could be reached with lateral ulnar collateral ligament release (Wrightington approach). METHODS: The 3 approaches were performed on 8 adult cadaveric elbows: first, the Kocher approach; then, the anconeus-splitting approach; and finally, the Wrightington approach. The visible articular surface was marked out after completion of each approach. RESULTS: The mean articular surface of the capitellum was 708 mm2 (range, 573-830 mm2). The mean visible articular surface was 49% (range, 43%-60%) of the total surface with the Kocher approach, 74% (range, 61%-90%) with the posterior anconeus-splitting approach, and 93% (range, 91%-97%) with the Wrightington approach. Although the Kocher approach provided access to the anterior part of the capitellum, the anconeus-splitting approach showed adequate exposure to the posterior three-quarters of the articular surface and overlapped the most posterior part of the Kocher approach. A combination of the 2 lateral ulnar collateral ligament-preserving approaches allowed access to 100% of the joint surface. CONCLUSION: Most OCD lesions are located in the posterior area of the capitellum and can therefore be reached with the anconeus-splitting approach. When OCD lesions are located anteriorly, the Kocher approach without ligament release is efficient. A combination of these 2 approaches enabled the entirety of the joint surface to be viewed.

Corrective Open-wedge Valgus Proximal Humerus Lengthening Osteotomy. Technique and Case Series.

Symptomatic varus malunion after proximal humeral fractures is associated with weakness and painful limitation of shoulder range of motion. When there is conformity of the articular surface and no avascular necrosis, a head-preserving procedure is best indicated. Arthroscopic arthrolysis, subacromial decompression, and tuberoplasty have been described for the treatment of mild deformity. In cases with more severe deformity, corrective extracapsular lateral closing wedge valgus osteotomy has been reported as a reliable treatment option, in terms of both pain relief and improved function. While this procedure adequately restores rotator cuff tensioning, it is associated with a shortening of the lever arm to the deltoid muscle, secondary to a loss of humeral length. We describe our technique and results with a vascular-sparing, medial open-wedge osteotomy, using a structural allograft and lateral locking plate. In our opinion, this procedure is safe and effective, with the potential to improve functional outcomes in young and active patients.

[Support algorithm for lateral elbow pain syndrome in adults]. / Douleurs latérales du coude chez l'adulte : algorithme de prise en charge.

Lateral elbow pain syndrome in adults is a frequent complaint leading to consultation in primary care medicine. The lateral side of the elbow joint represents a complex anatomy with close proximity of bony structures (humerus, radius, and ulna), ligaments (lateral ligament complex), tendons (origin of the extensors of the wrist and fingers), and nerves (branches of the radial nerve) making diagnostic and therapeutic management demanding. This article aims to provide a basis for reflection to better define treatment options for pathologies frequently encountered in clinical practice.

Les douleurs de la face latérale du coude chez l'adulte sont un motif fréquent de consultation en médecine de premier recours. La face latérale de cette articulation représente une anatomie complexe avec une proximité des structures osseuses (humérus, radius et ulna), ligamentaires (complexe ligamentaire latéral), tendineuses (origine des extenseurs du poignet et des doigts) et nerveuses (branches du nerf radial) rendant l'orientation diagnostique et la prise en charge thérapeutique exigeantes. Cet article propose une base de réflexion pour mieux définir les options de prises en charge des pathologies fréquemment retrouvées en pratique clinique.

Single-bolus injection of local anesthetic, with or without continuous infusion, for interscalene brachial plexus block in the setting of multimodal analgesia: a randomized controlled unblinded trial.

INTRODUCTION: Previous trials favored a continuous interscalene brachial plexus block over a single injection for major shoulder surgery. However, these trials did not administer a multimodal analgesic regimen. This randomized, controlled unblinded trial tested the hypothesis that a continuous infusion of local anesthetic for an interscalene brachial plexus block still provides superior analgesia after major shoulder surgery when compared with a single injection in the setting of multimodal analgesia, inclusive of intravenous dexamethasone, magnesium, acetaminophen and ketorolac. METHODS: Sixty patients undergoing shoulder arthroplasty or arthroscopic rotator cuff repair were randomized to receive a bolus of ropivacaine 0.5%, 20 mL, with or without a continuous infusion of ropivacaine 0.2% 4-8 mL/hour, for an interscalene brachial plexus block. Patients were provided with intravenous morphine patient-controlled analgesia. The primary outcome was cumulative intravenous morphine consumption at 24 hours postoperatively. Secondary outcomes included pain scores at rest and on movement, and functional outcomes, measured over 48 hours after surgery. RESULTS: Median (IQR) cumulative intravenous morphine consumption at 24 hours postoperatively was 10 mg (4-24) in the continuous infusion group and 14 mg (8-26) in the single injection group (p=0.74). No significant between-group differences were found for any of the secondary outcomes. CONCLUSIONS: A continuous infusion of local anesthetic for an interscalene brachial plexus block does not provide superior analgesia after major shoulder surgery when compared with a single injection in the setting of multimodal analgesia, inclusive of intravenous dexamethasone, magnesium, acetaminophen and ketorolac. The findings of this study are limited by performance and detection biases. TRIAL REGISTRATION NUMBER: NCT04394130.

Is sling immobilization necessary after open Latarjet surgery for anterior shoulder instability? A randomized control trial.

BACKGROUND: There is a current lack of knowledge regarding optimal rehabilitation and duration of sling immobilization after an open Latarjet procedure. A shift towards immediate self-rehabilitation protocols in shoulder surgery is observed to avoid postoperative stiffness and fasten return to sport. Avoiding sling immobilization could further simplify rehabilitation and provide an even faster return to activities of daily living and enhance patient satisfaction. METHODS: This study is a single-center, randomized control trial. Sixty-eight patients will be instructed with the same standardized immediate postoperative self-rehabilitation protocol. Patients will be allocated 1:1 between a sling immobilization group for the first three postoperative weeks and no sling group without postoperative immobilization. The primary endpoint will be functional outcome at 6 months postoperative evaluated by the disease-specific Rowe score. Secondary endpoints will include baseline, 1.5-, 6-, and 12-month single assessment numeric evaluation (SANE) of instability score and visual analog pain scale (VAS). At the 6-month time point, graft bony union and position will be assessed by computed tomography. Motion capture technology will evaluate the baseline and 6-month postoperative range of motion. Finally, time to return to work and sport during the first postoperative year, along with patient satisfaction at one postoperative year, will also be recorded. DISCUSSION: This study will allow further insights into the optimal rehabilitation protocol after open Latarjet surgery and enhance patient care by helping identify rehabilitation and coracoid graft-related factors influencing functional outcomes, bony union, range of motion, and patient satisfaction. TRIAL REGISTRATION: The protocol was approved by the ethical committee board (CCER 2019-02,469) in April 2020 and by ClinicalTrials.gov (Identifier: NCT04479397 ) in July 2020.

Age- and sex-specific normative values of bone mineral density in the adult glenoid.

The objective of this study was to determine the normative bone mineral density (BMD) of cortical and trabecular bone regions in the adult glenoid and its dependence on the subject's age and sex. We analyzed computed tomography (CT) scans of 441 shoulders (310 males, 18-69 years) without any signs of glenohumeral joint pathology. Glenoid BMD was automatically quantified in six volumes of interest (VOIs): cortical bone (CO), subchondral cortical plate (SC), subchondral trabecular bone (ST), and three adjacent layers of trabecular bone (T1, T2, and T3). BMD was measured in Hounsfield unit (HU). We evaluated the association between glenoid BMD and sex and age with the Student's t test and Pearson's correlation coefficient (r), respectively. The lambda-mu-sigma method was used to determine age- and sex-specific normative values of glenoid BMD in cortical (CO and SC) and trabecular (ST, T1, T2, and T3) bone. Glenoid BMD was higher in males than females, in most age groups and most VOIs. Before 40 years old, the effect of age on BMD was very weak in both males and females. After 40 years old, BMD declined over time in all VOIs. This BMD decline with age was greater in females (cortical: r = -0.45, trabecular: r = -0.41) than in males (cortical: r = -0.30; trabecular: r = -0.32). These normative glenoid BMD values could prove clinically relevant in the diagnosis and management of patients with various shoulder disorders, in particular glenohumeral osteoarthritis and shoulder arthroplasty or shoulder instability, as well as in related research.

The POSI study: gender differences in 94 cases of postoperative shoulder surgery infection: results of a 7-year retrospective multicenter study.

BACKGROUND: Contrary to lower limb infection, POstoperative Shoulder surgery Infection (POSI) often involves Cutibacterium acnes. Our aim was to describe patient characteristics and pathogens retrieved in POSI to guide initial empiric antibiotic selection with suspected infection during revision. We also compared microorganisms in infection following trauma, arthroplasty (AP), and arthroscopy (AS). METHODS: A multicenter retrospective study from 2010 to 2016 reviewed laboratory databases and medical records to identify patients with a previous shoulder surgery and a confirmed shoulder infection. The following procedures were included: AP, AS, fracture fixation (FF), and another open surgery (OS). A confirmed shoulder infection was defined as 2 positive cultures or more of the same microorganism, or clear clinical infection with 1 positive culture or more. RESULTS: Among the 5 hospitals and 28 surgeons involved, 94 POSI cases were identified. Mean age was 59 years at index surgery (range: 22-91) with a majority of men (n = 70, 74%). Among POSI cases, AP was the most common index surgery (n = 41), followed by FF (n = 27), AS (n = 16), and OS (n = 10). The median time between index surgery and the first positive sample was 5 months and the mean was 23 months (minimum 6 days to maximum 27 years), illustrating a positively skewed distribution. Cutibacterium spp were identified in 64 patients (68%), including 59 C acnes patients (63%), which was the most frequent germ in all 4 surgical groups. In 86% of cases, C acnes was identified at the first revision. The other 2 most common germs were Staphylococcus epidermidis and Staphylococcus aureus, with 29% and 17%, respectively. Polymicrobial infection was present in 30% of patients. Gender analysis revealed that C acnes was twice as frequent in men (male = 52 of 70, female = 7 of 24; P < .001). S epidermidis was more prevalent in women (n = 11; 46%) compared with men (n = 16; 21%) (P = .032). C acnes infection was most frequent in arthroscopic surgery (n = 14; 70%, P = .049). S epidermidis was 3 times more prevalent in chronic than in acute cases. CONCLUSION: Empiric antimicrobial therapy following POSI, while waiting for culture results, should cover C acnes, S epidermidis, and S aureus. There is a significant gender difference regarding POSI culture results. C acnes is more frequent in men, but should still be covered in women as it was found in 29% of cases.

Traumatic brain injuries are ignored or discriminated in prospective clinical trials on shoulder fractures: a systematic review.

PURPOSE: Current literature suggests a significant epidemiological association between traumatic brain injury (TBI) and proximal upper limb fractures in addition to major clinical consequences. A systematic review was conducted to assess how TBI is taken into consideration in interventional studies on shoulder fractures. METHODS: The following data sources were used: MEDLINE, EMBASE, EBM Reviews, CINAHL, and OpenGrey databases. Study selection included interventional randomized clinical trials and prospective cohort studies on shoulder fractures published in English or French between 2008 and 2020. Studies on pathologic fractures, chronic fracture complications, nonhuman subjects, and biomechanics were excluded. Articles were reviewed by two independent authors according to the PRISMA guidelines. Baseline characteristics, exclusion criteria, and input relevant to TBI were recorded. Methodological quality was assessed with the Cochrane risk of bias tool for randomized clinical trials and the Newcastle-Ottawa Scale for cohort studies. RESULTS: One-hundred-thirteen studies met the inclusion criteria. None discussed the possible impact of TBI on their results. Only three (2.7%) studies considered TBI relevant and included these patients in their cohort. Furthermore, 43/113 (38.1%) excluded patients with injuries or mechanisms strongly related to traumatic brain injuries: head injuries (4); moderate and/or severe TBI (7); high energy traumas (3); Polytrauma subjects (33). CONCLUSION: TBI are ignored or discriminated in prospective clinical trials on shoulder fractures. The exclusion of these cases impacts generalizability as their prevalence is significant. Considering the major impact of TBI on important outcomes, its presence should always be assessed to ensure high quality evidence. LEVEL OF EVIDENCE: Systematic Review, Therapeutic Level II.

Phone Administration of the Western Ontario Shoulder Instability Index Is More Reliable Than Administration via Email.

BACKGROUND: The Western Ontario Shoulder Instability (WOSI) questionnaire is a 21-item questionnaire to evaluate quality of life in patients with shoulder instability. Completing the questionnaire is time-consuming because each item is evaluated on a visual analog scale. Telephone or email versions of the score are appealing alternatives to administering it during the standard in-person patient visit; however, their validity and reliability remain unknown. QUESTIONS/PURPOSES: (1) Does the numerical scale (NS) version of the WOSI correlate with the original WOSI and Quick-DASH? (2) Do telephone and email administration of the NS-WOSI have good reliability and consistency? (3) Compared with the original WOSI form, does the NS form lead to faster completion for patients and quicker data extraction for researchers? METHODS: Between 2014 and 2019, 50 patients with a documented history of shoulder dislocation with persistent symptomatic shoulder instability, whether anterior, posterior, or multidirectional; patients scheduled for surgery; and patients with traumatic or nontraumatic injuries were prospectively recruited from the outpatient clinic of two university hospitals acting as Level 1 trauma centers and sports traumatology tertiary referral centers. The median (IQR) age was 28 years (24 to 36), and 80% (40 of 50) were men. Most (52% [26 of 50]) patients had two to five lifetime shoulder dislocations. Validity of the NS-WOSI was assessed using the Pearson correlation coefficient during an in-person visit; the original WOSI questionnaire (or its previously validated French-language version), NS-WOSI, and Quick-DASH questionnaires were administered in a random order. After a minimum 7-day interval, 78% (39 of 50) of patients completed the phone interview, and 74% (37 of 50) of patients completed the email version of the NS-WOSI score to evaluate NS-WOSI's reliability using the intraclass correlation coefficient (ICC), which was interpreted as poor (< 0.5), moderate (0.50-0.75), strong (0.75-0.90), and very strong (> 0.90). The standard error of measurement (SEM) was used to evaluate variability around the true score, with a low value indicating a high reliability. The 95% minimal detectable change (MDC 95% ) was calculated to evaluate the minimal change in score that was not related to measurement errors. Lastly, the Cronbach alpha was used to assess internal consistency (intercorrelation strength), where a value > 0.70 was considered good. The time needed for the patient to complete the various versions and for researchers to extract data was recorded. RESULTS: The NS-WOSI score was very strongly correlated with the original WOSI score (r = 0.96 [95% confidence interval (CI) 0.93 to 0.98]; p < 0.001). Although telephone-acquired and email-acquired data for the NS-WOSI questionnaires were correlated with the NS-WOSI (telephone r = 0.91 [95% CI 0.83 to 0.95]; p < 0.001; email r = 0.84 [95% CI 0.71 to 0.91]; p < 0.001), the ICC was higher for telephone interviews (0.92 [95% CI 0.86 to 0.96] versus email 0.80 [95% CI 0.64 to 0.89]), indicating that although both had good reliability, the phone interview was more suitable. The phone interview was also preferable to email regarding SEM (3% [52 of 2100 points] versus 6% [132 of 2100 points]) and the MDC 95% (7% [144 of 2100 points] versus 17% [366 of 2100 points]). The 95% CI of the MDC acquired by email was superior to the reported minimum clinically important difference for the original WOSI (7% [152 of 2100 points]), meaning that an error of measurement could wrongly be interpreted as a clinically significant change in score. Internal consistency was deemed good, with a Cronbach alpha of 0.96 (95% CI 0.92 to 98) and 0.89 (95% CI 0.79 to 0.94) for NS-WOSI telephone and email, respectively. The time to complete the NS-WOSI was reduced compared with the original WOSI (221 ± 153 seconds versus 266 ± 146 seconds, mean difference -45 seconds [95% CI -72 to -12]; p = 0.009). Lastly, data extraction was faster (62 ± 15 seconds versus 209 ± 52 seconds, mean difference -147 seconds [95% CI -164 to -130]; p < 0.001) with the NS-WOSI than with the original WOSI. CONCLUSION: The NS-WOSI in person, by telephone, or by email is a valid, reliable, and timesaving alternative to the original WOSI questionnaire. However, the reliability of data acquisition by telephone interviews was superior to that of email. CLINICAL RELEVANCE: Given that there were no important differences in performance for the NS-WOSI, regardless of whether it was administered in person or by phone, we suggest that physicians use both interchangeably based on patient convenience. However, we do not recommend using the email version, especially for research purposes, since it was not as reliable when compared with in-person administration. The responsiveness of the modified NS-WOSI, as well as factors influencing response rates to phone interview, are questions that remain to be explored.

Association of the Posterior Acromion Extension with Glenoid Retroversion: A CT Study in Normal and Osteoarthritic Shoulders.

Posterior eccentric glenoid wear is associated with higher complication rates after shoulder arthroplasty. The recently reported association between the acromion shape and glenoid retroversion in both normal and osteoarthritic shoulders remains controversial. The three-dimensional coordinates of the angulus acromialis (AA) and acromioclavicular joint were examined in the scapular coordinate system. Four acromion angles were defined from these two acromion landmarks: the acromion posterior angle (APA), acromion tilt angle (ATA), acromion length angle (ALA), and acromion axial tilt angle (AXA). Shoulder computed tomography scans of 112 normal scapulae and 125 patients with primary glenohumeral osteoarthritis were analyzed with simple and stepwise multiple linear regressions between all morphological acromion parameters and glenoid retroversion. In normal scapulae, the glenoid retroversion angle was most strongly correlated with the posterior extension of the AA (R2 = 0.48, p < 0.0001), which can be conveniently characterized by the APA. Combining the APA with the ALA and ATA helped slightly improve the correlation (R2 = 0.55, p < 0.0001), but adding the AXA did not. In osteoarthritic scapulae, a critical APA > 15 degrees was found to best identify glenoids with a critical retroversion angle > 8 degrees. The APA is more strongly associated with the glenoid retroversion angle in normal than primary osteoarthritic scapulae.

[Management of rotator cuff disorders. How to choose the most appropriate treatment option for my patient ?] / Prise en charge des lésions de la coiffe des rotateurs : choisir la meilleure option pour le patient.

Shoulder pain in the context of rotator cuff disorders is a frequent source of medical consultation. A wide range of therapeutic options is reported in the literature. Non- or minimally invasive treatments include physiotherapy, anti-inflammatory medication, and infiltration of corticosteroids or platelet-rich plasma. Surgical treatments include subacromial debridement, long head of the biceps tenotomy/tenodesis, rotator cuff repair, superior capsular reconstruction, and tendon transfers. Reverse shoulder arthroplasty completes the therapeutic arsenal. Guiding and advising the patient in the face of all these options can therefore be challenging. This article aims to summarize the clinical, demographic, and imaging characteristics useful in guiding and choosing the most appropriate treatment option for each patient.

La pathologie de la coiffe des rotateurs est une source fréquente de consultation. Les options thérapeutiques proposées dans la littérature sont vastes. Les traitements conservateurs comprennent la physiothérapie, les anti-inflammatoires ainsi que l'infiltration de corticostéroïdes ou de plasma riche en plaquettes. Les traitements chirurgicaux incluent le débridement sous-acromial, les gestes sur le tendon du long chef du biceps, la réinsertion des tendons de la coiffe des rotateurs, la reconstruction capsulaire supérieure et les transferts tendineux. La prothèse d'épaule inversée vient compléter l'arsenal thérapeutique. Conseiller le patient face à toutes ces options peut donc s'avérer complexe. Cet article vise à résumer les caractéristiques cliniques, démographiques et radiologiques permettant d'orienter au mieux chaque patient.

Biomechanics of anatomic and reverse shoulder arthroplasty.

The biomechanics of the shoulder relies on careful balancing between stability and mobility. A thorough understanding of normal and degenerative shoulder anatomy is necessary, as the goal of anatomic total shoulder arthroplasty is to reproduce premorbid shoulder kinematics.With reported joint reaction forces up to 2.4 times bodyweight, failure to restore anatomy and therefore provide a stable fulcrum will result in early implant failure secondary to glenoid loosening.The high variability of proximal humeral anatomy can be addressed with modular stems or stemless humeral components. The development of three-dimensional planning has led to a better understanding of the complex nature of glenoid bone deformity in eccentric osteoarthritis.The treatment of cuff tear arthropathy patients was revolutionized by the arrival of Grammont's reverse shoulder arthroplasty. The initial design medialized the centre of rotation and distalized the humerus, allowing up to a 42% increase in the deltoid moment arm.More modern reverse designs have maintained the element of restored stability but sought a more anatomic postoperative position to minimize complications and maximize rotational range of motion. Cite this article: EFORT Open Rev 2021;6:918-931. DOI: 10.1302/2058-5241.6.210014.

Unrecognized Chondrosarcoma as a Cause of Total Hip Arthroplasty Failure.

BACKGROUND: Total hip arthroplasty (THA) is one of the most successful procedures in orthopedic surgery. The most frequent THA indications are osteoarthritis and avascular necrosis, whereas symptomatic aseptic loosening is the most common indication to revision surgery. Chondrosarcoma (CS) is the most frequent bone sarcoma in adults, and proximal femur is the most prevalent location. Wide resection is the treatment of choice.We report 3 cases of unrecognized high-grade CS in the setting of primary or revision THA and reviewed the literature on this rare clinical presentation. METHODS: A systematic literature review on CS in the setting of THA, published between 1980 and 2020, was performed on PubMed, Embase, Medline, Ovid SP, and Web of Science, using the guidelines set in the Preferred Reporting Items for Systematic Reviews and Mata-analyses (PRISMA). RESULTS: Case series: Three patients were referred to our sarcoma center after failure of THA due to unrecognized high-grade CS. All 3 had rapid fatal outcome. Literature review: Fifty-nine articles were identified, of which 8 were included in the study. They confirmed that primary or revision THA failure due to unrecognized CS is extremely rare, with only few cases reported in the literature. CONCLUSIONS: Before proceeding to primary or revision arthroplasty, diagnosis must be ascertained. Atypical presentation of a common pathology, such as osteoarthritis, avascular necrosis, or aseptic loosening of an endoprosthesis, should raise suspicion for another cause to symptoms, and additional workup be performed. As our cases demonstrated, unrecognized or inadequately managed bone sarcoma may lead to poor or even fatal outcome.

Image-guided percutaneous cryoablation of unresectable sacrococcygeal chordoma: Feasibility and outcome in a selected group of patients with long term follow-up.

BACKGROUND: Chordoma is a rare malignant tumor of the axial skeleton. Percutaneous cryoablation (PCA) is a minimally invasive technique that allows freezing of tumors under imaging control. The purpose of our retrospective study was to investigate the outcome of PCA in a selected cohort of patients with sacrococcygeal chordoma, with a minimum of 5 years follow-up. MATERIALS AND METHODS: Four patients were treated in 10 sessions. The mean follow-up was 57.3 months. We evaluated the feasibility, the procedure-related complications, the impact on pain control and oncological outcomes. RESULTS: Freezing of 100% of the tumor volume was possible in 60%. Pain control was not reliably evaluable. Local recurrence occurred in 90% of the treated lesions; the mean time to progression was 8.1 months (range 1.5-16). At last follow-up, one patient had died of the disease, one of another cause and one was receiving the best supportive care. The only patient alive without the disease had received additional carbon-ion radiotherapy. The 5-year survival rate after index PCA was 50%. CONCLUSION: Complete freezing of the tumor was technically challenging, mainly due to the complex local anatomy. Recurrence occurred in 90% of the lesions treated. PCA should be considered with caution in the curative management of sacrococcygeal chordoma.

Shoulder biomechanics in normal and selected pathological conditions.

The stability of the glenohumeral joint depends on soft tissue stabilizers, bone morphology and dynamic stabilizers such as the rotator cuff and long head of the biceps tendon. Shoulder stabilization techniques include anatomic procedures such as repair of the labrum or restoration of bone loss, but also non-anatomic options such as remplissage or tendon transfers.Rotator cuff repair should restore the cuff anatomy, reattach the rotator cable and respect the coracoacromial arch whenever possible. Tendon transfer, superior capsular reconstruction or balloon implantation have been proposed for irreparable lesions.Shoulder rehabilitation should focus on restoring balanced glenohumeral and scapular force couples in order to avoid an upward migration of the humeral head and secondary cuff impingement. The primary goal of cuff repair is to be as anatomic as possible and to create a biomechanically favourable environment for tendon healing. Cite this article: EFORT Open Rev 2020;5:508-518. DOI: 10.1302/2058-5241.5.200006.

Cryoablation of Extra-Abdominal Desmoid Tumors: A Single-Center Experience with Literature Review.

Cryoablation (CA) has gained popularity in the treatment of benign and malignant musculoskeletal tumors. While extra-abdominal desmoid (EAD) tumors are not malignant, they remain challenging to treat because of their high local recurrence rate. We reviewed all EAD tumors treated with CA at our institution between November 2012 and March 2020. Fourteen procedures were performed on nine females and one male (mean age, 33 ± 18 years) as either first-line (n = 4) or salvage therapy (n = 6) with curative intent (n = 8) or tumor debulking (n = 2). Mean tumor size was 63.6 cm3 (range, 3.4-169 cm3). Contrast-enhanced MRI was performed before treatment and at 3-, 6-, and 12-month follow-up. Treatment outcome was based on the change in enhanced tumor volume (ET-V). For curatively treated patients, the mean ET-V change was -97 ± 7%, -44 ± 143%, and +103 ± 312% at 3, 6, and 12 months, respectively. For debulking patients, the mean ET-V change was -98 ± 4%, +149 ± 364%, and +192 ± 353% at 3, 6, and 12 months, respectively. During a mean follow-up of 53.7 months (range, 12-83 months), one grade III and one grade IV complication were noted. We found CA to be safe and well tolerated in patients with EAD.

Distal humerus nonunion: evaluation and management.

Despite recent improvements in surgical implants and techniques, distal humerus nonunion does occur between 8% and 25% of the time.Careful identification and improvement of any modifiable risk factors such as smoking, metabolic disorders, immunosuppressant medications, poor nutritional status and infection is mandatory.A recent computed tomography scan is paramount to determine the nonunion pattern, assess residual bone stock, identify previously placed hardware, and determine whether there is evidence of osteoarthritis or malunion of the articular surface.Internal fixation is the treatment of choice in the majority of patients presenting with reasonable bone stock and preserved articular cartilage; total elbow arthroplasty is an appealing alternative for elbows with severe destruction of the articular cartilage or severe bone loss at the articular segment, especially in older, female patients. Internal fixation requires not only achieving a stable fixation, but also releasing associated elbow contractures and the liberal use of bone graft or substitutes.Although reported union rates after internal fixation of distal humerus nonunions are excellent (over 95%), the complication rate remains very high, and unsatisfactory results do occur. Cite this article: EFORT Open Rev 2020;5:289-298. DOI: 10.1302/2058-5241.5.190050.