Nonunion of the so-called acromion: a systematic review with consideration of the terminology.

INTRODUCTION: There is no widely accepted standard for the classification and treatment of traumatic acromion/scapular spine fracture nonunion due to the scarcity of this condition and the confusion of terminology. MATERIALS AND METHODS: PubMed and Scopus were searched using "scapular fracture" and "acromion fracture" or "scapular spine fracture" as search terms. The inclusion criteria were English full-text articles concerning acromion/scapular spine fracture nonunion that described patient characteristics and presented appropriate images. The exclusion criteria were cases without appropriate images. Citation tracking was conducted to find additional articles and notable full-text articles written in other languages. Fractures were classified using our newly proposed classification system. RESULTS: Twenty-nine patients (19 men, 10 women) with 29 nonunions were identified. There were four type I, 15 type II, and 10 type III fracture nonunions. Only 11 fractures were isolated. The mean period from initial injury to final diagnosis was 35.2 ± 73.2 months (range 3-360 months) (n = 25). The most frequent cause of delayed diagnosis was conservative treatment for fracture in 11 patients, followed by oversight by the physician in 8. The most common reason for seeking medical advice was shoulder pain. Six patients received conservative therapy, and 23 received operative treatment. Fixation materials included various plates in 15 patients, and tension band wiring in 5. Bone grafting was performed in 16 patients (73%, 16/22). Of the 19 surgically treated patients with adequate follow-up, the outcome was rated excellent in 79%. CONCLUSIONS: Isolated acromion/scapular spine fracture nonunion is rare. Fracture type II and III, arising in the anatomical scapular spine, accounted for 86% of the fractures. Computed tomography is required to prevent fracture oversight. Surgical therapy produces good stable results. However, it is important to select the appropriate surgical fixation method and material after considering the anatomical characteristics of the fracture and stress on the fractured portion. LEVEL OF EVIDENCE: V.

The study of screw placement parameters for Ogawa type I acromial fractures by 3D simulation.

BACKGROUND: Acromial fractures are rare and there is no consensus on fixation, but an increasing number of studies have reported using two screws to fix Ogawa type I acromial fractures. The objective of this study was to obtain the ideal length, diameter, insertion point, and angle of the screw using a novel 3D simulation. METHODS: The scapular CT data of 100 individuals were obtained to reconstruct 3D models. The transparency of the 3D model was then downgraded along the axial perspective (the view perpendicular to the cross section of the acromion axis) to find the maximum translucent area. Two virtual screws were placed at the anterior edge of the acromion until they penetrated the posterior cortical bon. The largest diameters and lengths of the screw were measured, and the direction and insertion point of the screw were observed. RESULTS: The mean maximum lengths of the medial and lateral screws were 43.33 ± 6.17 mm and 39.23 ± 6.01 mm, respectively. The mean maximum diameters of the medial and lateral screws were 4.71 ± 1.23 mm and 4.97 ± 1.07 mm, respectively. Differences in screw length, diameter, and insertion point between males and females were found. The differences in screw angle between sexes were not statistically significant. CONCLUSIONS: Based on a 3D model test, we recommend the size, entry points, and angles of screws for Ogawa type I acromial fractures, providing valuable guidance for clinical work. More accurate screw parameters can be obtained preoperatively by establishing an individualized 3D model.

A Simple Bone Cyst of the Acromion: Case Report / Cisto ósseo simples do acrômio: Relato de caso

Abstract Simple bone cysts rarely occur in the scapula, and, to our knowledge, they have not been reported in the acromion. In the present report, we present the case of a 24-year-old female patient who was successfully treated by curettage and grafting using xenografting. No recurrence findings were observed during the follow-up six months postoperatively, the patient had recovered full range of motion, and she was able to perform all routine activities satisfactorily.

Resumo Cistos ósseos simples são raros na escápula, e, pelo que sabemos, não foram relatados no acrômio. Aqui, apresentamos uma paciente do sexo feminino, de 24 anos, submetida com sucesso ao tratamento composto por curetagem e xenoenxerto. Não foram observados achados de recidiva no acompanhamento pós-operatório de seis meses, quando a paciente apresentou amplitude total de movimento e foi capaz de realizar todas as atividades rotineiras de maneira satisfatória.

Incidence and risk factors of acromial fracture following reverse total shoulder arthroplasty.

BACKGROUND: The occurrence and related predictors of acromial fracture following reverse total shoulder arthroplasty (RTSA) have not been fully elucidated. The aim of this study was to determine the incidence and risk factors of acromial fractures after RTSA. METHODS: We conducted a multicenter, retrospective case-control study of 787 cases (29 in acromial fracture group and 758 in control group) that underwent RTSA performed by 6 surgeons. The mean duration of follow-up after RTSA was 31.6 ± 21.8 months (range, 12-136 months). Demographic variables (age, sex, arm dominance, body mass index, working status, bone mineral density [BMD]), clinical variables (preoperative diagnosis, previous operation, implant design, preoperative clinical scores, screw size in glenoid fixation, postoperative rehabilitation), and radiographic variables (acromial thickness, critical shoulder angle, deltoid length, humeral offset to lateral acromion) were investigated. To determine risk correlation, univariate analysis and multivariate logistic regression analysis with calculated odds ratios (ORs) were performed. RESULTS: Postoperative acromial fractures occurred in 29 of the 787 shoulders with RTSA (3.7%). Acromial fractures were detected at a mean of 10.0 months (range, 1-66 months) postoperatively. Univariate analysis revealed that the occurrence of an acromial fracture was significantly associated with a previous operation (38% [11 of 29] vs. 21% [156 of 758], P = .025) and BMD (-2.33 vs. -1.74, P = .013). Multivariate logistic regression analysis found that the occurrence of a postoperative acromial fracture was significantly associated with a previous operation (P = .034; OR, 2.91; 95% confidence interval, 1.08-7.84) and deltoid length (P = .004; OR, 1.04; 95% confidence interval, 1.01-1.07). CONCLUSION: Acromial fracture following RTSA is not an uncommon complication, with an overall incidence of 3.7%. A previous operation, increased deltoid length, and low BMD were risk factors of acromial fracture following RTSA.

Acromial and Scapular Fractures After Reverse Total Shoulder Arthroplasty with a Medialized Glenoid and Lateralized Humeral Implant: An Analysis of Outcomes and Risk Factors.

This article was updated on TK because of a previous error, which was discovered after the preliminary version of the article was posted online. In Table VII, the fracture rate in the study by Walch et al. that had read "4.6% (21 of 457)" now reads "0.9% (4 of 457)." BACKGROUND: Acromial and scapular fractures after reverse total shoulder arthroplasty (rTSA) are rare and challenging complications, and little information is available in the literature to identify patients who are at risk. This study analyzes risk factors for, and compares the outcomes of patients with and without, acromial and scapular fractures after rTSA with a medialized glenoid/lateralized humeral implant. METHODS: Four thousand one hundred and twenty-five shoulders in 3,995 patients were treated with primary rTSA with 1 design of reverse shoulder prosthesis by 23 orthopaedic surgeons. Sixty-one of the 4,125 shoulders had radiographically identified acromial and scapular fractures. Demographic characteristics, comorbidities, implant-related data, and clinical outcomes were compared between patients with and without fractures to identify risk factors. A multivariate logistic regression, 2-tailed unpaired t test, and chi-square test or Fisher exact test identified significant differences (p < 0.05). RESULTS: After a minimum duration of follow-up of 2 years, the rate of acromial and scapular fractures was 1.77%, with the fractures occurring at a mean (and standard deviation) of 17.7 ± 21.1 months after surgery. Ten patients had a Levy Type-1 fracture, 32 had a Type-2 fracture, 18 had a Type-3 fracture, and 1 fracture could not be classified. Patients with acromial and scapular fractures were more likely to be female (84.0% versus 64.5% [p = 0.004]; odds ratio [OR] = 2.75 [95% confidence interval (CI) = 1.45 to 5.78]), to have rheumatoid arthritis (9.8% versus 3.3% [p = 0.010]; OR = 3.14 [95% CI = 1.18 to 6.95]), to have rotator cuff tear arthropathy (54.1% versus 37.8% [p = 0.005]; OR = 2.07 [95% CI = 1.24 to 3.47]), and to have more baseplate screws (4.1 versus 3.8 screws [p = 0.017]; OR = 1.53 [95% CI = 1.08 to 2.17]) than those without fractures. No other implant-related differences were observed in the multivariate analysis. Patients with fractures had significantly worse outcomes than patients without fractures, and the difference in mean improvement between these 2 cohorts exceeded the minimum clinically important difference for the majority of measures. CONCLUSIONS: Acromial and scapular fractures after rTSA are uncommon, and patients with these fractures have significantly worse clinical outcomes. Risk factors, including female sex, rheumatoid arthritis, cuff tear arthropathy, and usage of more baseplate screws were identified on multivariate logistic regression analysis. Consideration of these findings and patient-specific risk factors may help the orthopaedic surgeon (1) to better inform patients about this rare complication preoperatively and (2) to be more vigilant for this complication when evaluating patients postoperatively. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Anatomic Restoration of Triple Disruption of the Superior Shoulder Suspensory Complex: A Case Report and Review of the Literature.

BACKGROUND: Multiple disruptions of the superior shoulder suspensory complex (SSSC) involving more than two components are extremely rare. In some extreme situations, three components of the SSSC structure can be involved. The ideal treatment for this type of injury is debatable. CASE PRESENTATION: A 21-year-old woman was referred to our emergency center following a traffic accident. A three-dimensional CT scan showed triple disruption of the SSSC involving concomitant ipsilateral fractures of the coracoid, the acromion, and the distal clavicle. The connection between the upper limber and the axial skeleton was destroyed. There was no evidence of associated injury and the neurovascular examination of the injured upper limb was normal. The patient underwent an open reduction and internal fixation to restore the anatomic integrity of the SSSC. The arm was supported in a broad arm sling for 2 weeks after surgery. Gentle passive range of motion activity under analgesic was encouraged from the second day postoperatively. One year and half after the operation, the patient had regained pain free and unrestricted shoulder stability and mobility. CONCLUSION: The manifestations of multiple disruptions of the SSSC may be variable. This case illustrated the challenges of treating the multiple disruption of the SSSC structure. It also showed that surgical intervention for this rare combination injury yields an excellent functional result. The good outcome achieved in this patient demonstrates that surgical intervention might be an optional resolution for multiple disruptions of the SSSC.

Locked 90°-double plating of scapular spine fracture after reverse shoulder arthroplasty with union and good outcome despite plate adjacent acromion fracture.

We report the case of a 74-year-old woman who sustained a scapular spine (SS) fracture after a fall 4 weeks after reverse shoulder arthroplasty (RSA). Open reduction and internal fixation (ORIF) with locked 90°-double plating resulted in union of the SS fracture with a good outcome (subjective shoulder value: 80%; Constant score 67; 1 year) despite of an adjacent lateral acromion fracture 3 weeks after ORIF. This is the second description in the literature of a successful double plate ORIF with union of an SS fracture after RSA. SS fractures are known to lead to poor RSA outcomes with a high mal-union rate and non-union rate. We describe the positioning of the plates and technical steps for successful ORIF to avoid complications, discuss the aftercare and report the outcome.

Scapular Ring Preservation: Coracoacromial Ligament Transection Increases Scapular Spine Strains Following Reverse Total Shoulder Arthroplasty.

BACKGROUND: Scapular fractures following reverse total shoulder arthroplasty (RSA) are devastating complications with substantial functional implications. The role of the coracoacromial ligament (CAL), which is often transected during surgical exposure for RSA, is not fully known. We hypothesized that the CAL contributes to the structural integrity of the "scapular ring" and that the transection of this ligament during RSA alters the scapular strain patterns. METHODS: RSA was performed on 8 cadaveric specimens without evidence of a prior surgical procedure in the shoulder. Strain rosettes were fixed onto the acromial body (at the location of Levy type-II fractures) and the scapular spine (Levy type III). With use of a shoulder simulator, strains were recorded at 0°, 30°, and 60° glenohumeral abductions before and after CAL transection. The deltoid and glenohumeral joints were functionally loaded (middle deltoid = 150 N, posterior deltoid = 75 N, and joint compression = 300 N). Maximum principal strains were calculated from each rosette at each abduction angle. A repeated-measures analysis of variance with post hoc analysis was performed to compare the maximum principal strain at each abduction angle. RESULTS: With the CAL intact, there was no significant difference between strain experienced by the acromion and scapular spine at 0°, 30°, and 60° of glenohumeral abduction. CAL transection generated significantly increased strain in the scapular spine at all abduction angles compared with an intact CAL. The maximum scapular spine strain observed was increased 19.7% at 0° of abduction following CAL transection (1,216 ± 300.0 microstrain; p = 0.011). Following CAL transection, acromial strains paradoxically decreased at all abduction angles (p < 0.05 for all). The smallest strains were observed at 60° of glenohumeral abduction at the acromion following CAL transection (296 ± 121.3 microstrain; p = 0.048). CONCLUSIONS: The CAL is an important structure that completes the "scapular ring" and therefore serves to help distribute strain in a more normalized fashion. Transection of the CAL substantially alters strain patterns, resulting in increased strain at the scapular spine following RSA. CLINICAL RELEVANCE: CAL preservation is a modifiable risk factor that may reduce the risk of bone microdamage and thus the occurrence of fatigue/stress fractures in the scapular spine following RSA.

Postoperative results of Ogawa type IIB meta-acromion fracture fixation with a 90° twisted reconstruction plate.

INTRODUCTION: Acromion fractures are rare and difficult to treat. There is no consensus on type of fixation. Due to the rarity of the injury, it is difficult to compare different techniques of osteosynthesis. OBJECTIVES: The aim of this study was to present the long-term results of an alternative method of plating Ogawa type IIB meta-acromion fractures and to review the literature. DESIGN: Retrospective study. MATERIALS AND METHODS: We present a case series of 11 consecutive patients with displaced Ogawa type IIB meta-acromion fracture, treated with open reduction internal fixation using a 3.5-mm contoured pelvic reconstruction plate with a 90° twist. Patients' mean age was 53.3 years (23-80 years) and the mean follow-up was 48.3 months (15 months-9 years). The outcomes related to pain and shoulder function were evaluated by Modified American Shoulder and Elbow Surgeons Score (ASES) and SF-36 score. All patients were asked about their satisfaction level. RESULTS: Nine out of eleven patients were included in this study. Eight of them obtained union and all were satisfied with the final outcome. The mean ASES and SF-36 score were 69.75 (42.4-98.14) and 61.37 (41.64-94.99), respectively, with poor scores to be largely associated with comorbidities and concomitant injuries. CONCLUSIONS: The use of 3.5-mm reconstruction plate with a 90° twist for open reduction internal fixation (ORIF) of meta-acromion fractures presents satisfactory results and could be technically a more stable biomechanical construct in comparison to the existing surgical techniques.

Os acromiale: systematic review of surgical outcomes.

BACKGROUND: The literature is unclear as to the optimal surgical management of a symptomatic os acromiale that has failed nonoperative treatment. Surgical options include excision, acromioplasty, and open reduction and internal fixation. The purpose of this study is to summarize the described methods and compare their reported outcomes with the goal to provide direction on how to surgically manage os acromiale. METHODS: We performed a systematic review of the current medical literature. Fifteen studies met all the inclusion criteria. Two hundred eleven total subjects (220 shoulders) underwent surgical treatment for a symptomatic os acromiale. There were 140 men and 71 women with a mean age of 49.6 ± 9.1 years. The mean follow-up duration was 40 ± 11.6 months. Surgical techniques used in the included studies were excision, acromioplasty, and open reduction with internal fixation. Concurrent surgical procedures performed were also included. RESULTS: Meso-os acromiale was the most common type (167 cases, 94.4%). The most common surgical technique was internal fixation (135 cases, 60.8%), with screw fixation being the majority (76 cases, 56.3%). Excision (65 cases, 29.3%) was the second most used technique. The most common concurrent surgical procedure performed was rotator cuff repair (125 cases, 56.3%), followed by distal clavicle excision (31 cases, 14%). CONCLUSIONS: All surgical techniques employed resulted in improvement in postsurgical clinical outcomes without any technique demonstrating superior results. Operative management of a symptomatic os acromiale that has failed initial nonoperative treatment leads to decreased symptoms and improvement in clinical outcomes.

Acromial stress fracture following reverse total shoulder arthroplasty: incidence and predictors.

BACKGROUND: Increased use of reverse total shoulder arthroplasty (RTSA) has led to an understanding of unique complications such as acromial stress fractures (ASFs). The factors associated with ASFs are not fully known. This study investigates the incidence and predictors of ASFs following RTSA. METHODS: All RTSAs performed at a single tertiary referral hospital were retrospectively reviewed. ASF findings were classified as a definitive acromial or scapular spine stress fracture based on radiographic findings or stress reaction based on clinical findings (pain and tenderness at the acromion or acromial spine) without radiographic changes. Preoperative and postoperative radiographs were reviewed for radiographic predictors of postoperative acromial stress pathology. Clinical factors and implant characteristics were also investigated. RESULTS: Between September 2010 and January 2017, a total of 1170 RTSAs were performed, with 958 cases (81.9%) having at least 3 months' clinical follow-up (mean, 407 days; range, 90-1698 days). There were 40 ASFs (4.2%) and 61 acromial stress reactions (6.4%). For fractures and reactions, symptom onset averaged 8.8 and 7.3 months (P = .37), respectively, with durations of 4.5 and 2.9 months (P = .02), respectively, following RTSA. Independent predictors of acromial stress pathology were female sex, decreased change in deltoid length, and increased preoperative glenohumeral center-of-rotation medialization. CONCLUSION: Acromion-related symptoms are common following RTSA. Female patients with increased preoperative center-of-rotation medialization had an increased incidence of ASFs. Although this study establishes which patients are at risk of ASFs, methods for prevention of ASFs in these patients remain unclear.

Reconstrucción anatómica del Acromion en casos de fracturas traumáticas y posterior a artroplastia reversa del Hombro. Reporte de Casos / Anatomic reconstruction of the acromion in cases of traumatic fractures after reverse shoulder arthroplasty. Report of a series of cases

Introducción Tanto las fracturas traumáticas del acromion, así como las fracturas acromiales por insuficiencia posterior a artroplastia reversa del hombro, son entidades poco frecuentes. Con la ampliación des los criterios operativos para la artroplastia reversa del hombro, es de suponer un aumento en el caso des las fracturas acromiales por insuficiencia posteriores a dicho procedimiento quirúrgico. Al ser estas entidades poco frecuentes hacen falta en la literatura recomendaciones basadas en la evidencia para el manejo de estas, las cuales representan un reto para el especialista tratante. Materiales y Métodos Reporte de seis casos entre 2013 y 2016 en el hospital cantonal de Frauenfeld (Suiza) de dos grupos de pacientes con fracturas del Acromion. En el grupo A se clasificaron tres pacientes que presentaron fractura por insuficiencia del acromion posterior a artroplastia reversa del Hombro. En el grupo B clasificaron tres pacientes con fracturas traumáticas del acromion en las cuales el manejo conservador no fue exitoso. Los dos grupos de pacientes fueron sometidos al mismo método quirúrgico con reducción abierta y reconstrucción anatómica del Acromion por medio de fijación con placa y tornillos interfragmentarios. Resultados Posterior a la intervención quirúrgica, la función del hombro se recuperó en todos los pacientes del Grupo A. La flexión anterior aumentó en promedio de 53° a 127°, y la abducción mejoró de 52° a 125°. Las mediciones posteriores al año de la intervención mostraron puntajes constantes entre 55-71, así como un valor subjetivo de hombro (SSV) de 50-90. En el Grupo B, el rango de movimiento preoperatorio se mantuvo constante. La flexión hacia delante mejoró de 133° a 157° y la abducción aumentó de 147° a 153°. Un año después de la cirugía, los puntajes de Constant en el grupo B variaron de 70 a 86 y el SSV se encontró entre 80 a 100. Los tres pacientes del Grupo B consiguieron retomar sus actividades diarias sin dolor y pudieron regresar al trabajo. La extracción de la placa fue necesaria en la mitad de los pacientes de la cohorte (Grupo A n=1, Grupo B n=2). Discusión La fractura del acromion es una condición seria que puede causar daño significativo al funcionamiento del hombro. Tanto en pacientes con ARH así como en pacientes sin ARH previa, nuestra técnica operativa abierta de reconstrucción anatómica del acromion mostró buenos resultados. Recomendamos el manejo quirúrgico por medio de reconstrucción con placa y clavos de fijación. Nivel de evidencia: IV

Aim To propose a surgical technique to treat the traumatic acromion fractures, as well as acromion fractures before reverse total Shoulder Replacement (TSR). Methods Six patients were treated with the same fixation technique between December 2013 and December 2016. Three patients had acromial insufficiency fractures (type II) following TSR (Group A). The other three patients, who had traumatic acromion fractures, underwent unsuccessful conservative treatment (Group B). Surgical treatment involved reconstruction of the acromion using an open technique with plate and interfragmentary screw fixation. Results Following reconstruction, shoulder function was regained in all patients in Group A. Forward flexion increased, on average, from 53° to 127°, and abduction improved from 52° to 125°. Measurements at one-year follow-up were Constant scores from 55-71, and subjective shoulder value (SSV) from 50-90. In Group B, preoperative range of motion was not substantially diminished. Forward flexion improved from 133° to 157°, and abduction increased from 147° to 153°. One year following surgery, the Constant scores in Group B ranged from 70-86, and SSV was 80-100. All three patients performed daily activities without pain, and were able to return to work. Plate removal was necessary in half the patients in the cohort (Group A n=1; Group B n=2). Conclusion An acromion fracture is a serious condition that can cause significant damage to shoulder functioning. In patients with or without previous TSR, this fixation technique was used successfully to reconstruct the anatomic lateral and basal acromion. Evidence Level: IV

Is Acromial Fracture after Reverse Total Shoulder Arthroplasty a Negligible Complication?: A Systematic Review.

BACKGROUND: The purpose of this study was to investigate the incidence of acromial fracture after reverse total shoulder arthroplasty (RTSA) and clinical and radiological outcomes of treatment of the fracture. METHODS: A systematic review was performed to identify studies that reported the results of treatment of acromial fractures after RTSA. A literature search was conducted by two investigators using four databases (PubMed, Embase, Cochrane, and Ovid Medline). RESULTS: Fifteen studies (2,857 shoulders) satisfied our inclusion criteria. The incidence of acromial fracture after RTSA was 4.0% (114 / 2,857). The mean age of the patients at the time of fracture was 72.9 years (range, 51 to 91 years). The mean time from RTSA to diagnosis of acromial fracture was 9.4 months (range, 1 to 94 months). One hundred shoulders (87.7%) were treated conservatively and 14 shoulders (12.3%) were treated surgically. The mean follow-up period after acromial fracture was 33.8 months. The overall union rate was 50.0% (43.8% for conservative treatment and 87.5% for operative treatment). The fracture incidence was significantly different among the medial glenoid and medial humerus prosthesis design (8.4%), the lateral glenoid and medial humerus design (4.0%), and the medial glenoid and lateral humerus design (2.8%). The mean values at final follow-up were as follows: visual analog scale score, 2.2; American Shoulder and Elbow Surgeons score, 59.1; Constant score, 59.7; and Simple Shoulder Test, 5.8. The mean forward flexion, abduction, and external rotation were 102.3°, 92.3°, and 25.8°, respectively. CONCLUSIONS: Acromial fractures after RTSA are a complication neither uncommon nor negligible. In the absence of studies with high-level evidence, there is a controversy on the outcomes after treatment. Further well-designed prospective randomized controlled studies with a long-term follow-up should be performed to ascertain the diagnosis, treatment, and prognosis of acromial fractures after RTSA.

[Ipsilateral Fractures of the Coracoid and Acromion Process of the Scapula Combined with the Distal Clavicle End Fracture, Treatment Options]. / Ipsilaterální zlomenina processus coracoideus a akromionu lopatky v kombinaci se zlomeninou laterální cásti klavikuly, terapeutická moznost resení.

Superior Shoulder Suspensory Complex (SSSC) is a bone and soft-tissue ring securing the connection of the upper extremity to the axial skeleton via the clavicle and sternoclavicular joint. An isolated injury to one component of SSSC is usually stable. An injury to 2 of its components is a potential source of shoulder girdle instability and requires surgical stabilisation. An injury affecting 3 and more components is extremely rare and surgical stabilisation should be indicated. Our study presents the case of a 50-year-old man who fell off the bicycle and sustained a direct blow to his left shoulder resulting in an ipsilateral fracture of the coracoid and acromion process combined with the fracture of the distal end of the clavicle. Following a standard clinical examination and a subsequent X-ray and a CT scan with three-dimensional shoulder reconstruction, an open reduction and stabilisation of all the injured SSSC components was performed. Later, early and gradual rehabilitation of the shoulder girdle was commenced. At 48 weeks after the surgery, almost full range of motion of the shoulder joint was achieved and the muscle strength of the operated upper extremity was comparable to that of the healthy one. Key words:Superior Shoulder Suspensory Complex, fracture, acromion, coracoid process, clavicle.

The traumatic acromion fracture: review of the literature, clinical examples and proposal of a treatment algorithm.

PURPOSE: Traumatic acromion fractures are rare and typically occur in patients with multiple fractures, which often delays diagnosis. Limited guidance exists on the treatment of these fractures. We present a review of the literature from the last 20 years and describe our experience in treating five patients-two conservatively and three with open reduction and internal fixations (ORIF). METHODS: We used the U.S. National Library of Science database, MEDLINE®, to search for all pertinent publications from January 1999 to December 2017. Included were retrospective or prospective studies, including case series and case reports, describing treatment for traumatic acromion fractures and clinical and/or radiological outcomes. For our case reports, we present five patients with traumatic acromion fractures who were treated at our institution between 2013 and 2017. RESULTS: Through our review of 14 publications, we found that current recommendations are often based on a limited number of cases. No gold standard to treat these fractures exists. Most authors recommend anatomic reconstruction, especially for dislocated fractures, persistent symptomatic non-unions or additional injuries to the superior shoulder suspensory complex. There is no clear trend in terms of the operative technique. With regard to our five clinical examples that were all initially treated conservatively, two were successful and three eventually required reconstruction with ORIF. Based on the findings of this review, we proposed a treatment algorithm for traumatic acromion fractures. CONCLUSIONS: A classification system providing clear guidance on treatment options is needed. Although the non-union rate with conservative treatment is relatively high, it is not always painful or limiting to shoulder function, especially in elderly or less active patients. Fixation seems to be a more suitable treatment option for active patients who are more likely to require revision of symptomatic non-unions.

Acromial spine fracture after reverse total shoulder arthroplasty: a systematic review.

BACKGROUND: Reverse total shoulder arthroplasty (RSA) accounts for nearly one-third of shoulder arthroplasty utilization nationally. The complication rate has increased concurrently. Consensus is lacking regarding the incidence, etiology, and treatment of acromial or scapular spine fractures after RSA. The purpose of our study was to perform a systematic review of the literature to analyze the occurrence and outcomes of this complication. METHODS: The MEDLINE, Embase, Google Scholar, and Cochrane databases were queried in late 2017 for combinations of the words "acromial," "fracture," "reverse," "shoulder," and "arthroplasty." We included all studies that contained a clearly defined performance of RSA, acromial fracture(s) noted, and treatment (if any) and outcomes of treatment. The initial search yielded 50 studies; 32 met the inclusion criteria. RESULTS: Among 3838 RSAs, 159 acromial fractures were reported, for an overall incidence of 4.14%; the mean time to diagnosis from surgery was 9 months (range, 1.3-24 months). Treatments included nonoperative treatment in a sling or abduction brace in 139 cases and open reduction-internal fixation in 20. Regardless of treatment, patients reported inferior function after fracture compared with initially after RSA. Forward flexion was 95° (range, 30°-110°), abduction was 76° (range, 30°-180°), the Constant score was 63 (range, 59-67.5), and the American Shoulder and Elbow Surgeons score was 57 (range, 7-83); all values were reduced compared with patients without fractures. CONCLUSION: This study suggests the occurrence of acromial fractures after RSA is a common event, with a rate of over 4%. These fractures correlate with worse postoperative outcomes regardless of treatment method; open reduction-internal fixation was not shown to be clinically superior despite a limited complication rate. Additional high-quality studies addressing acromial spine fracture after RSA are needed.

Osteosynthesis of type III acromial fractures with locking compression plate, lateral clavicular plate, and reconstruction plate: a biomechanical analysis of load to failure and strain distribution.

BACKGROUND: Acromial stress fractures following reverse shoulder arthroplasty have been increasingly studied because of potential functional impairment caused by this complication. The purpose of this study was to evaluate and compare different plating techniques for a type III acromial fracture (also referred to as "scapular spine fracture") in a biomechanical setting with special regard to primary stability and modes of failure. METHODS: Type III acromial fractures were simulated on 19 Sawbones scapulae and plated with either a lateral clavicular plate (LatCP), a locking compression plate (LCP), or a reconstruction plate (RecoP). We performed testing on 5 scapulae for each plate according to a staircase protocol (100 cycles each step): 50 N and 100 N, then increasing 100 N each step up to 800 N or until failure. The last series of mechanical tests included 3-dimensional micro-motion analysis. RESULTS: The average force needed to cause failure of the osteosynthesis construct was 376 N for the LatCP, 506 N for the LCP, and 360 N for the RecoP. The difference between the LCP and RecoP was significant (P = .047). The average displacements of the acromion were 12.1 mm, 13.4 mm, and 11.7 mm, respectively. The spring constant was not significantly different between the plates. The LatCP showed increased strain medially, whereas the strain on the RecoP was spread more laterally. The LCP presented a balanced strain distribution, spread evenly over the fracture line. CONCLUSIONS: In a biomechanical setting, the LCP showed superiority over the LatCP and RecoP as stabilization hardware for type III acromial fractures.

[Arthroscopically Assisted Minimally Invasive Fixation of a Type D2c Scapular Fracture]. / Arthroskopisch gestützte minimalinvasive Schraubenosteosynthese einer Skapulafraktur Typ D2c nach Euler/Rüdi.

Fractures of the scapula are rare and have an incidence of 1% of all fractures. Publications highlight glenoid rim fractures. Classification by Ideberg and Euler and Rüdi are accepted. Euler and Rüdi describe three extra-articular and two intra-articular fracture patterns. The indications for surgery are displaced glenoid fractures, scapula tilt of more than 40° and injuries to the superior shoulder suspensory complex. We describe a case of a 22 year old man, who while cycling collided with a moving car due to wet roads. After his admission to hospital as a polytraumatised patient, the trauma CT-Scan showed haemothorax with several associated rip fractures, displaced humeral shaft fracture and fractures of the acromion and glenoid, classified as type D2c according to Euler and Rüdi. Following damage control principles, drainage of the haemothorax was already performed in the ER and surgical treatment of the displaced humeral shaft fracture was performed on the day of admission. No peripheral neurological deficits were evident. After pulmonary stabilisation, surgery was performed 6 days later on the glenoid and acromion fracture, which in conjunction may be regarded as an injury to the superior shoulder suspensory complex. We performed an arthroscopically-assisted screw fixation of the glenoid fracture (type D2c according to Euler and Rüdi) and an ORIF procedure at the acromion. Postoperative rehabilitation was performed with passive abduction and elevation up to 90° for the first two weeks and active abduction an elevation up to 90° for weeks 3 to 6. Full ROM was allowed at week 7. CONCLUSION: Articular fractures of the glenoid are rare and mainly seen as rim fractures. The indications for surgery are displaced articular fractures and injury to the superior shoulder suspensory complex. As demonstrated by this article, type D2c fractures according to Euler and Rüdi can be treated effectively as an arthroscopically-assisted screw fixation procedure.

[Simultaneous fracture of the acromion and coracoid process : Rare variant of double disruption of the superior shoulder suspensory complex]. / Gleichzeitige Frakturen von Acromion und Korakoid : Seltene Variante der doppelten Unterbrechung des "superior shoulder suspensory complex".

INTRODUCTION: Simultaneous fracture of the acromion and coracoid process represents a double disruption of the superior shoulder suspensory complex (SSSC). To date, the two largest reported series have comprised five and eight cases. The aim of this study was to investigate the functional outcome in patients who sustained this rare injury and to provide a review of the relevant literature. MATERIAL AND METHODS: In this retrospective study, patients who were surgically treated between 2009 and 2014 were identified from medical records and the patients were asked to attend a follow-up examination. Functional results, measured as the Constant score and Disabilities of the Arm, Shoulder and Hand (DASH) score, were the main outcomes of the study. RESULTS: A total of six patients underwent surgery for this type of double disruption of the SSSC. All but one patient suffered a high-impact trauma with other associated injuries. The coracoid fracture was classified as type I according to Ogawa in all cases, and the acromion fracture was type III according to Kuhn in 5 out of 6 cases. At least one of the fracture sites was stabilized. Of the patients one showed a concurrent lateral clavicle fracture, representing a third disruption of the SSSC, and another had a fracture of the medial third of the clavicle, representing a strut fracture. In these cases, two fracture sites were operated on. At an average follow-up period of 47 months all but one fracture had healed. In one patient, asymptomatic non-union of the acromion was found. The average DASH score was 22 points and the average Constant score was 74 points. CONCLUSION: This rare injury pattern is usually caused by high-impact trauma, and concomitant injuries frequently occur. Nevertheless, surgical stabilization of at least one of the fracture sites showed satisfactory functional results.

Os acromiale open reduction and internal fixation: a review of iliac crest autogenous bone grafting and local bone grafting.

BACKGROUND: Symptomatic os acromiale are fairly uncommon, and treatment has included fragment excision, decompression, and open reduction and internal fixation. Nonunion rates as high as 40% have been reported after fixation of os acromiale. This study assessed whether union of an os acromiale could be reliably achieved without the use of an iliac crest bone graft. METHODS: This was a retrospective study of 32 consecutive shoulders that were treated with screw fixation and a local bone graft or iliac crest bone graft. The mean age was 50.3 years (range, 21-74 years), and the mean follow-up was 46.9 months (range, 12-120 months). Fusion was assessed clinically and radiologically. RESULTS: All 32 os acromiale were fused by 3 months on x-ray imaging. There were 18 shoulders in the iliac crest bone graft group and 14 in the local bone graft group. Rotator cuff repairs were performed concomitantly in 25 patients. Hardware was removed in 4 patients, a seroma was drained in 1 patient, and a superficial infection occurred in 1 patient. CONCLUSION: This is the largest study of os acromiale fixation using screws and a tension band to our knowledge. We report a 100% union rate using this technique, with 13% requiring hardware removal and the occurrence of 1 superficial infection. This study shows a local bone graft is as effective as iliac crest bone graft in achieving fusion.