Atraumatic Shoulder Instability Research Articles

Glenohumeral Joint Volume Measurement in Patients with Shoulder Instability: A 3D Volumetric Magnetic Resonance Arthrographic Study.

Background and Objectives: This study aimed to compare capsular volume in patients with shoulder instability to that in control subjects without instability using magnetic resonance (MR) arthrography. The objective was to develop a reliable screening method with which to assess shoulder volume. Materials and Methods: In 21 patients with atraumatic shoulder instability and 21 controls, thin-slice 3D volumetric MR arthrography sequences were obtained. MR arthrography images were uploaded to 3D reconstruction, and 3D images were generated. From the 3D reconstructed images, volumetric measurements of rotator interval (RI), anterior and posterior capsular (AC, PC) recesses, biceps tendon sheath (BS), axillary recess (AR), and total glenohumeral joint (TGJ) were performed. Individuals with any extra-articular contrast leakage were also recorded. Results: A retrospective study analyzed a patient group of 21 individuals with shoulder instability (mean age 29.52 ± 12.83 years) and a control group of 21 individuals without instability (mean age 35.71 ± 12.77 years). No statistically significant differences were identified between the groups with regard to age, gender, or side distribution. The mean total joint volume was significantly higher in the instability group (29.85 ± 6.40 cm3) compared to the control group (23.15 ± 3.48 cm3, p = 0.0001). Additionally, the mean volumes of the RI, AC, PC, BS, and AR were all significantly greater in the patient group compared to the control group. Conclusions: 3D volumetric MR arthrographic measurements of the shoulder joint capacity can provide valuable insights for clinical follow-up and guide surgical treatment decisions in cases of atraumatic shoulder instability.

Pediatric and Adolescent Shoulder Instability.

Traumatic and atraumatic shoulder instability is common in pediatric and adolescent patients. It is well-established that young patients with anterior shoulder dislocation are at high risk of recurrent instability. This review assesses the current literature pertaining to management of both anterior instability and MDI in the pediatric and adolescent populations. Current research suggests that pediatric and adolescent patients with shoulder instability have excellent outcomes following arthroscopic Bankart repair; however, higher rates of recurrent instability requiring revision surgical management have been identified in patients with more than one dislocation episode pre-operatively, those with Hill-Sachs lesions and those under age 16. The addition of the remplissage procedure to an arthroscopic Bankart repair may be useful in preventing recurrent instability for patients with large Hill-Sachs lesions. Open procedures with bony glenoid augmentation may be indicated in patients with significant glenoid bone loss, or those who have failed primary surgical management, with promising outcomes reported following the Latarjet coracoid process transfer procedure in the adolescent population. Pediatric and adolescent patients with hyperlaxity, and those participating in swimming or gymnastics are more likely to have multidirectional instability (MDI). Non-surgical management with physical therapy is the mainstay of treatment for MDI with positive outcomes reported overall. In young patients with MDI who continue to have symptoms of instability and pain that effects daily activities or sports despite an adequate and appropriate course of rehabilitation, surgical management with capsulorrhaphy may be considered, with promising outcomes reported for both open and arthroscopic techniques. Attentive selection of timing and surgical procedure for pediatric and adolescent patients with anterior shoulder instability may help to prevent recurrent instability following shoulder stabilization. Although most pediatric and adolescent patients with MDI do well following non-surgical management alone, those that fail conservative management have good outcomes following arthroscopic or open capsulorrhaphy.

Poster 165: Psychosocial Factors Play a Greater Role in Preoperative Symptoms for Patients with Atraumatic Shoulder Instability: Data from the Moon-Shoulder Instability Group

Objectives:Previous studies have demonstrated altered brain activation patterns on functional MRI for those with shoulder instability suggesting a potential link between recurrent instability, depression, and emotional wellbeing. It is unknown whether this potential link would differ between those with traumatic vs. atraumatic instability. The purpose of this study was to determine whether psychosocial factors and/or comorbid depression play a greater role in preoperative symptoms for patients with atraumatic or traumatic mechanisms of shoulder instability. We hypothesized that when controlling age, sex, and direction of instability, psychosocial factors and comorbid depression would be more predictive of shoulder-related pain and symptoms for patients with atraumatic instability than patients with traumatic instability.Methods:As part of the IRB-approved Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Instability cohort, 1553 patients provided informed consent and completed pre- and intraoperative data collection. Patients were categorized based on self-reports of whether the mechanism of shoulder instability was traumatic (n=1267) or atraumatic (n=286). Multivariable linear regressions were performed to determine whether psychological factors (VR12, Mental Component Score (MCS), Depression Diagnosis, PAS-22) were predictive of preop ASES and WOSI score in the atraumatic group, controlling for age, sex, and the direction of instability. The same model was repeated for the traumatic instability group, and the model fit was compared between groups using the methods described by Cohen, Cohen, and West with p < 0.05 considered statistically significant.Results:Sex and Mental Component Scores (MCS) were significantly predictive of preop ASES and WOSI scores for the group with atraumatic instability (ASES r2=0.15, p<0.001; WOSI r2=0.17 p<0.001). The same model performed significantly worse for both ASES and WOSI scores in the group with traumatic instability (ASES r2=0.06, WOSI r2=0.07, p<0.05 for both ASES and WOSI).Conclusions:Preoperative psychosocial factors were found to be more predictive of shoulder-related pain and symptoms for patients with atraumatic instability. Across multiple orthopedic conditions, depression and emotional wellbeing have been associated with worse preoperative symptoms and inferior postoperative patient-reported outcomes. As opposed to medically optimizing patients prior to surgery, the current findings identify a subset of shoulder instability patients that may need to be psychologically optimized either prior to surgery or early in the postoperative period to potentially improve postoperative outcomes.

Sex-specific Considerations for Shoulder Instability and Adhesive Capsulitis in Females

There has been an increasing focus on sex-specific differences within the context of sports medicine. Differences exist between the sexes leading to disparities in the types of injuries female athletes sustain and the rates at which they experience them. Recognition and awareness of subtle differences between the sexes can lead to a more nuanced diagnosis and treatment of such injuries. The purpose of this study is to review shoulder pathologies that are relevant to the female athlete, specifically adhesive capsulitis, multidirectional instability, and traumatic unidirectional shoulder instability, and highlight the differences in diagnosis, treatment, and outcomes between the sexes. Women suffer from adhesive capsulitis at a greater rate than men and there are risk factors such as breast cancer surgery that are unique to women. Females are much more likely to experience atraumatic shoulder instability than their male counterparts. While females represent a minority of patients who suffer traumatic unidirectional shoulder instability, they should not be overlooked with regards to this condition. There are challenges related to the diagnosis and treatment of these pathologies that are distinctive to female athletes.

Rehabilitation for atraumatic shoulder instability in circus arts performers: delivery via telehealth.

The Watson Instability Program (WIP1) is current best evidence for conservative management of atraumatic shoulder instability, but it is unknown if this program can be effectively delivered via tele-consultation. The purpose of this longitudinal pre-post intervention study was to determine the effects of the WIP1 on patient-reported outcome measures, scapular position, shoulder strength, and handstand stability in student circus performers with atraumatic shoulder instability when delivered via tele-consultation. Student circus performers aged between 15 and 35 years from the National Institute of Circus Arts were recruited. A 12-week shoulder exercise program was delivered via tele-consultation during the Melbourne, Australia COVID-19 (coronavirus disease 2019) lockdown. The primary outcome measures were the Western Ontario Shoulder Instability Index score and the Melbourne Instability Shoulder Scale score. Secondary outcomes measures included the Orebro Musculoskeletal Pain Questionnaire, the Tampa Scale for Kinesiophobia, and physical assessment measures including strength via handheld dynamometry, scapular position using an inclinometer, and handstand stability via center-of-pressure fluctuation. Patient-reported outcomes were collected at baseline and 6-week, 12-week, 6-month, and 9-month time points, and physical outcomes were measured at baseline and 9-month time points. A repeated-measures mixed model (with effect sizes [ESs] and 95% confidence intervals [CIs]) was used to analyze patient-reported outcomes, handstand data, strength, and scapular measures. Significance was set at P < .05. Twenty-three student circus arts performers completed the study. Significant improvements were found in both Western Ontario Shoulder Instability Index scores (effect size [ES], 0.79 [95% CI, 0.31-1.33] at 6 weeks; ES, 1.08 [95% CI, 0.55-1.6] at 12 weeks; ES, 1.17 [95% CI, 0.62-1.78] at 6 months; and ES, 1.31 [95% CI, 0.74-1.95] at 9 months; P < .001) and Melbourne Instability Shoulder Scale scores (ES, 0.70 [95% CI, 0.22-1.22] at 6 weeks; ES, 0.83 [95% CI, 0.34-1.37] at 3 months; ES, 0.98 [95% CI, 0.46-1.54] at 6 months; and ES, 0.98 [95% CI, 0.43-1.50] at 9 months; P < .001), as well as Orebro Musculoskeletal Pain Questionnaire scores at all follow-up time points. The Tampa Scale for Kinesiophobia scores reached significance at 6 weeks and 12 weeks. Following rehabilitation, we found statistically significant increases in shoulder strength in all positions tested and increased scapular upward rotation measured at end-of-range abduction, as well as during loaded external rotation. The affected arm showed greater instability than the unaffected arm with a significant intervention effect on the affected arm showing a greater consistent anterior-posterior movement pattern. In a group of circus performers with atraumatic shoulder instability, treatment with the WIP1 via telehealth resulted in clinically and statistically significant improvements in shoulder symptoms and function.

A systematic review to compare physiotherapy treatment programmes for atraumatic shoulder instability.

Optimal physiotherapy treatment is uncertain for atraumatic shoulder instability (ASI), the primary aim of this systematic scoping review was to compare physiotherapy treatment programmes for people with ASI. The secondary aims were to evaluate outcome measures used and to compare the effectiveness of these programmes. CINAHL, EMBASE and Medline databases were searched for studies, except single case studies, published between 1950 and July 2021. 12 critical appraisal items covered three domains; internal validity, transferability to wider population and reporting. Ten studies were included; one randomised controlled trial, 6 cohort studies and 3 case series. There were 491 participants. Treatment programmes included education, movement re-education, static posture correction, shoulder muscle strengthening, functional training, and adjuncts. All studies used patient reported outcome measures (PROMs), 7 of which reported a statistically significant improvement (p < 0.05) post-treatment. There was no clear relationship between programmes and outcomes. PROMs specific to shoulder instability were all found to detect statistically significant differences post-treatment. There does not appear to be one optimal physiotherapy treatment programme for ASI. Future studies should use PROMs that are valid in the shoulder instability population and use more outcome measures that are specific to impairments being targeted.

Does grip strength correlate with rotator cuff strength in patients with atraumatic shoulder instability?

AimTo investigate if there is a correlation between grip strength (GS) and rotator cuff (RC) strength in patients with atraumatic shoulder instability (ASI) and to compare the relationship between these two measures with that previously published for a healthy population. Moreover, to determine if testing GS could be incorporated as a surrogate clinical assessment for RC strength in these patients.MethodsA total of 20 subjects with ASI were included. Out of the 20 patients, eight presented with bilateral instability, which constituted a total of 28 atraumatic unstable shoulders (N = 28). GS was measured using a Jamar hand-dynamometer. External rotation (ER) and internal rotation (IR) strength was tested in inner and outer ranges using a hand-held dynamometer (HHD). Pearson’s correlation test was computed to investigate the relationship. Multiple linear regression was conducted to predict GS based on RC strength.ResultsSignificant and strong positive correlations were found between GS and inner-range IR (r = 0.764, P < 0.001), inner-range ER (r = 0.611, P = 0.001), outer-range IR (r = 0.817, P < 0.001), and outer-range ER (r = 0.736, P < 0.001). A significant regression equation was found (F (4, 23) = 13.254, P < 0.001), with an R2 of 0.697 indicating that RC strength explained 69.7% of the variance in GS.ConclusionsThe results support the hypothesis showing that GS is strongly associated with RC strength in ASI patients. The simplicity of handgrip testing allows it to be used in clinical scenarios where sophisticated assessment tools are not available. GS is a convenient means to monitor patient progress during shoulder rehabilitation programs.

Rehabilitation for atraumatic shoulder instability in circus arts performers: delivered via telehealth

Background: The Watson Instability Program (WIP1) is the highest level of evidence for the conservative management of atraumatic shoulder instability, but it is unknown if this program can be effectively delivered via teleconsultation. The aim of this study observational single cohort study was to determine the effects of the WIP1 on patient reported outcome measures, scapula position, shoulder strength and handstand stability in student circus performers with atraumatic shoulder instability, when delivered via teleconsultation.

Experiences of student circus arts performers undertaking a shoulder rehabilitation program via telehealth consultation during the COVID-19 pandemic

Background: The Coronavirus pandemic (COVID-19) has brought about significant change to athletes, with the postponement and cancellation of competitions and performances. This has created a need to proactively adapt to ensure peak mental and physical fitness. This requirement to adapt may be even more relevant for those athletes rehabilitating from injury during the pandemic. This qualitative study sought to explore the experiences of student circus arts performers with atraumatic shoulder instability undertaking a 12-week shoulder rehabilitation program during the Melbourne COVID-19 pandemic lockdown.

Management of atraumatic shoulder instability in physiotherapy (MASIP): a survey of physiotherapy practice

BackgroundThe impact of atraumatic shoulder instability (ASI) on patients can be extensive, its management complex, with a biopsychosocial approach recommended. Currently how physiotherapists manage ASI is unknown or the extent to which current clinical practice aligns with existing evidence. At the time of this study no national guidelines or consensus to direct practice existed.MethodsA cross-sectional electronic survey was distributed between July-September 2018, targeting UK-based physiotherapists managing shoulder pathology.Respondents were invited to describe their management of ASI, and rate their awareness and utilisation of various treatment techniques on a Likert-scale; median and interquartile ranges were calculated. Free text survey items were analysed using quantitative content analysis (QCA) to identify codes and categories. Means and percentages were calculated to summarise QCA and descriptive data.ResultsValid survey responses were analysed (n = 135). Respondents had between 2 and 39 years of physiotherapy experience (mean = 13.9 years); the majority (71.1 %) reported that ASI made up < 10 % of their caseload. Only 22.9 % (n = 31/135) of respondents reported feeling ‘very confident’ in managing ASI; the majority feeling ‘somewhat confident’ (70.4 %, n = 95/135) or ‘not confident’ (6.7 %, n = 9/135).The majority of respondents (59.3 %) used an ASI classification system, > 90 % citing the Stanmore Classification. Physiotherapists adapted their management according to clinical presentation, responding to differing biopsychosocial needs of the patient scenario. Most respondents (> 80 %) did not use a protocol to guide their management. Exercise was the most utilised management approach for ASI, followed by education; novel treatment strategies, including cortical rehabilitation, were also reported.ConclusionFindings indicate physiotherapists utilise a wide range of treatment strategies and respond to biopsychosocial cues when managing patients with ASI. The majority reported not being very confident in managing this condition, however only a minority use rehabilitation protocols to support their management. Some interventions that respondents reported using lacked evidence to support their use in ASI management and further research regarding effectiveness is required. Guidelines have been published since this survey; the impact of these will need evaluating to determine their effectiveness in the future.

Atraumatic shoulder instability: patient characteristics, comorbidities, and disability.

BackgroundAtraumatic shoulder instability of the shoulder is well described, and numerous extrinsic factors have been identified as having a negative influence on long-term shoulder function, including age, sex, smoking, and workers' compensation status. Furthermore, physical factors such as acute or chronic pain, as well as psychological comorbidities such as depression and suicidal thoughts, are common in shoulder-related conditions.MethodsPatients with atraumatic shoulder instability were recruited from a review of outpatient logbook and inpatient rehabilitation center admission records. Average and worst pain visual analogue scale rates were recorded for acute and chronic shoulder pain. Disability was measured using the “Disability of the Arm and Hand” score, as well as the Stanmore Percentage of Normal Shoulder Assessment (SPONSA). Depression was assessed using Becks Depression Inventory II, and further single psychological items were selected from other psychological assessment questionnaires.ResultsWe included 64 patients, of which 51 (79.7%) were female. Mean visual analogue scale pain scores were in average 5.11 (standard deviation 2.24) and 5.58 (standard deviation 2.34) for acute and chronic shoulder pain, respectively. A stepwise, multiple linear regression revealed that only chronic shoulder pain remained significantly related to disability (F(1,61) = 46.13, P < .001). A second linear regression analysis was performed and showed a significant association between the overall Disability of the Arm, Shoulder and Hand score and overall Becks Depression Inventory score (F(1,62) = 12.78, P < .001). A further stepwise, multiple linear regression analysis indicated that chronic pain and depression remain independent variables in the prediction of disability.ConclusionIn addition to sociodemographic factors, pain and psychological comorbidities were found to have a negative impact on patient's functional outcome. This study further supports the need for an multidisciplinary team, holistic approach in the management of atraumatic shoulder instability patients with particular emphasis on chronic pain management and psychological support.

Medical Interactive Recovery Assistant: a useful clinical tool in paediatric shoulder rehabilitation?

Background/aims Outpatient physical therapy is the mainstay of treatment in shoulder instability, but lack of motivation and intermittent monitoring of progress is associated with poor compliance. ‘Exergames’ (a combination of videogames and physical exercise) may provide an additional or alternative motivational factor. The aim of this study was to determine the applicability of the Medical Interactive Recovery Assistant Xbox Kinect gaming software in the management of adolescent atraumatic shoulder instability. Methods Patients completed six 30-minute sessions playing games using the Medical Interactive Recovery Assistant while participating in a therapy programme. Pain and fatigue questionnaires, functional assessments and a framework analysis of free-text comments were used. Results A total of 20 female patients (15 unilateral, five bilateral pathology, mean age 14.1 years) completed the sessions. An average session length was 10.8 mins (range 0–24 mins). After each session using the Medical Interactive Recovery Assistant, 80% were neither in pain, nor overly tired. At 2 weeks, the Stanmore Percentage of Normal Shoulder Assessment scores had improved by a mean 17.9% and 10 (50%) patients showed improvements in Oxford Shoulder Instability Scores. Overall, 15 participants (75%) liked the technology; however six (32%) preferred standard physiotherapy, because of software limitations and lack of personal interaction. Conclusions Medical Interactive Recovery Assistant gamification is applicable for this patient cohort and could be integrated into adolescent atraumatic shoulder instability rehabilitation programmes; however, results emphasise the importance of personal contact.

Experiences of Student Circus Arts Performers Undertaking a Shoulder Rehabilitation Program Via Telehealth Consultation During the COVID-19 Pandemic

To explore the subjective experiences of student circus arts performers with atraumatic shoulder instability undertaking a 12-week shoulder rehabilitation program during the COVID-19 pandemic lockdown, in Melbourne, Australia. Using a qualitative design, 14 circus arts students from the National Institute of Circus Arts (Australia) were individually interviewed via teleconsultation. All interviews were recorded, transcribed, and analysed using inductive thematic analysis. Five overarching themes were identified: (i) impact (physical and mental), (ii) opportunity, (iii) developing routine, (iv) client-therapist relationship, and (v) transformation. All participants reported positive physical changes to their shoulder including increases in strength, stability, range of motion, less pain, "clicking" and "clunking," improved posture, muscle memory, as well as carry-over to functional circus activities. The pandemic's mental impact varied across the cohort, with positive and negative experiences described in relation to cognitive, social, and affective factors. Most performers felt the pandemic provided an opportunity to focus on rehabilitation of their shoulder. The program effects were also underpinned by positive client-therapist relationships and a progressive transformation of learning where students gained knowledge of their condition, developed tools to manage their current shoulder impairment, and learned how to apply this new knowledge to future management of their condition. A shoulder exercise intervention delivered via teleconsultation during the COVID-19 pandemic resulted in subjective reports of positive physical changes to the participants' shoulder health complaint. This was facilitated through client-physiotherapist relationships, providing structure during uncertain times, and by providing education to help in understanding their condition and its future management.

Interprofessional Inconsistencies in the Diagnosis of Shoulder Instability: Survey Results of Physicians and Rehabilitation Providers.

BackgroundClinicians of many specialties within sports medicine care for athletes with shoulder instability, but successful outcomes are inconsistent. Consistency across specialties in the diagnosis of shoulder instability is critical for care of the athlete, yet the extent of divergence in its diagnosis is unknown.HypothesisPhysicians differ from rehabilitation providers in which findings they deem clinically important to differentiate shoulder instability from impingement, and in how they diagnose athlete scenarios with atraumatic shoulder instability.Study DesignCross-sectional study.MethodsPhysicians (orthopaedic surgeons, primary care sports medicine physicians) and rehabilitation providers (physical therapists, athletic trainers) were asked via an online survey to rate clinical factors used to diagnose shoulder instability. Clinicians were also asked to diagnose two athlete scenarios with concurrent clinical findings of atraumatic shoulder instability and impingement, differentiated by the absence or presence of a positive sulcus sign.ResultsResponses were recorded from 888 clinicians. Orthopaedic surgeons (N=170) and primary care sports medicine physicians (N=108) ranked physical examination factors as more important for the diagnosis of shoulder instability than patient history factors, whereas physical therapists (N=379) and athletic trainers (N=231) preferred patient history factors. Orthopaedic surgeons differed from physical therapists and athletic trainers in their clinical diagnoses for both scenarios (P≤0.001).ConclusionA lack of consistency exists among sports medicine clinicians in recognizing which clinical factors are important when used to diagnose shoulder instability and in diagnoses given with concurrent findings of impingement.Level of EvidenceLevel 3.

Biomechanical and Proprioceptive Study of Atraumatic Shoulder Instability in Ehlers-Danlos Syndrome

The aim of the study was to assess biomechanical and clinical examination of Ehlers-Danlos Syndrome patients with shoulder instability.

Arthroscopic Stabilisation of Atraumatic Shoulder Instability: Minimum Two Year Outcomes

To assess the safety and efficacy of arthroscopic inferior capsular shift in the context of atraumatic shoulder instability at minimum two-year follow up.

Intra-Rater and Inter-Rater Reliability of Hand-Held Dynamometry for Shoulder Strength Assessment in Circus Arts Students.

Over two testing sessions, two experienced physiotherapists assessed the shoulder strength of 24 student circus artists with clinically diagnosed atraumatic shoulder instability. Both the symptomatic and asymptomatic shoulder was assessed using a HHD in 10 functional positions. Intra-class correlation coefficients (ICCs) were calculated to determine the reliability of strength measurements. All examined positions showed moderate-high intra-rater and inter-rater reliability. External rotation at 0° and internal rotation in horizontal flexion at 45° revealed the most reliable results, and the shrug position the least reliable. Inter-rater and intra-rater reliability was high and demonstrated similar results in symptomatic and asymptomatic shoulders by both raters. This study demonstrated clinical applicability in reliably measuring functional strength in symptomatic atraumatic instability or asymptomatic shoulders when assessed by experienced therapists using an HHD.

Posterior Open-wedge Osteotomy and Glenoid Concavity Reconstruction Using an Implant-free, J-shaped Iliac Crest Bone Graft in Atraumatic Posterior Instability with Pathologic Glenoid Retroversion and Dysplasia: A Preliminary Report.

Atraumatic posterior shoulder instability in patients with pathologic glenoid retroversion and dysplasia is an unsolved problem in shoulder surgery. In a preliminary study of a small group of patients with atraumatic posterior shoulder instability associated with glenoid retroversion ≥ 15° and glenoid dysplasia who underwent posterior open-wedge osteotomy and glenoid concavity reconstruction using an implant-free, J-shaped iliac crest bone graft, we asked: (1) What proportion of the patients had persistent apprehension? (2) What were the improvements in patient-reported shoulder scores? (3) What were the radiographic findings at short-term follow-up? Between 2016 and 2018, we treated seven patients for atraumatic posterior shoulder instability. We performed this intervention when posterior shoulder instability symptoms were unresponsive to physiotherapy for at least 6 months and when it was associated with glenoid retroversion ≥ 15° and dysplasia of the posteroinferior glenoid. All seven patients had a follow-up examination at a minimum of 2 years. The median (range) age at surgery was 27 years (16 to 45) and the median follow-up was 2.3 years (2 to 3). Apprehension was assessed by a positive posterior apprehension and/or posterior jerk test. Patient-reported shoulder scores were obtained and included the subjective shoulder value, obtained by chart review (and scored with 100% representing a normal shoulder; minimum clinically important difference [MCID] 12%), and the Constant pain scale score (with 15 points representing no pain; MCID 1.5 points). Radiographic measurements included glenohumeral arthropathy and posterior humeral head subluxation, bone graft union, correction of glenoid retroversion and glenoid concavity depth, as well as augmentation of glenoid surface area. All endpoints were assessed by individuals not involved in patient care. In four of seven patients, posterior apprehension was positive, but none reported resubluxation. The preoperative subjective shoulder value (median [range] 40% [30% to 80%]) and Constant pain scale score (median 7 points [3 to 13]) were improved at latest follow-up (median subjective shoulder value 90% [70% to 100%]; p = 0.02; median Constant pain scale score 15 points [10 to 15]; p = 0.03). Posterior glenoid cartilage erosion was present in four patients (all four had Walch Type B1 glenoids) preoperatively and showed no progression until the final follow-up examination. The median (range) humeral head subluxation index decreased from 69% (54% to 85%) preoperatively to 55% (46% to 67%) postoperatively (p = 0.02), and in two of four patients with preoperative humeral head subluxation (> 65% subluxation), it was reversed to a centered humeral head. CT images showed union in all implant-free, J-shaped iliac crest bone grafts. The median preoperative retroversion was corrected from 16° (15° to 25°) to 0° postoperatively (-5° to 6°; p = 0.02), the median glenoid concavity depth was reconstructed from 0.3 mm (-0.7 to 1.6) preoperatively to 1.2 mm (1.1 to 3.1) postoperatively (p = 0.02), and the median preoperative glenoid surface area was increased by 20% (p = 0.02). No intraoperative or postoperative complications were recorded, and no reoperation was performed or is planned. In this small, retrospective series of patients treated by experienced shoulder surgeons, a posterior J-bone graft procedure was able to reconstruct posterior glenoid morphology, correct glenoid retroversion, and improve posterior shoulder instability associated with pathologic glenoid retroversion and dysplasia, although four of seven patients had persistent posterior apprehension. Although no patients in this small series experienced complications, the size and complexity of this procedure make it likely that as more patients have it, some will develop complications; future studies will need to characterize the frequency and severity of those complications, and we recommend that this procedure be done only by experienced shoulder surgeons. The early results in these seven patients justify further study of this procedure for the proposed indication, but longer term follow-up is necessary to continue to assess whether it is advantageous to combine the reconstruction of posterior glenoid concavity with correction of pathological glenoid retroversion and increasing glenoid surface compared with traditional surgical techniques such as the posterior opening wedge osteotomy or simple posterior bone block procedures. Level IV, therapeutic study.

Glenoid Orientation and Profile in Atraumatic or Microtraumatic Posterior Shoulder Instability: Morphological Analysis Using Computed Tomography Arthrogram.

Background:Posterior shoulder instability (PSI) is a relatively uncommon condition that occurs in about 10% of patients with shoulder instability. PSI is usually associated with dislocations due to acute trauma and multidirectional instability, but it can also occur with or without recognizable recurrent microtrauma. The infrequency of atraumatic or microtraumatic PSI and the lack of a full understanding of the pathoanatomy and the knowledge of management can lead to misdiagnosis or delayed diagnosis.Purpose:To evaluate the morphologic factors of the glenoid that are associated with atraumatic or microtraumatic PSI.Study Design:Cross-sectional study; Level of evidence, 3.Methods:Enrolled in this study were patients who underwent arthroscopic posterior labral repair between January 2013 and March 2017 and were diagnosed with posterior glenohumeral instability by means of preoperative computed tomography arthrography (CTA) (n = 39; PSI group). These patients did not have any significant dislocation or subluxation episodes. The morphologic factors of the glenoid as revealed using CTA were compared with the CTA images from a sex-matched control group (n = 117) of patients without PSI who had been diagnosed with adhesive capsulitis in an outpatient clinic. The glenoid version and shape were evaluated between the 2 groups using the CTA findings, and the degree of centricity of the humeral head to the glenoid was assessed in the PSI group. Multivariate logistic regression analysis was performed to identify factors associated with PSI.Results:The results of the multivariate logistic regression analysis indicated no statistically significant difference between the PSI and control groups regarding glenoid version or a flat-shaped glenoid. However, statistically significant between-group differences were found regarding convex glenoid shape, with an odds ratio of 5.39 (95% CI, 1.31-23.35; P = .0207). The proportion of eccentricity was significantly higher in the PSI group (21/39; 54%) versus the control group (47/117; 40%) (P = .031).Conclusion:The presence of convex glenoid shape was significantly associated with atraumatic or microtraumatic PSI. Humeral head eccentricity accounted for a high percentage of convex glenoid shape. However, there was no significant correlation between PSI and glenoid retroversion.

Outcomes of Conservative Treatment for Atraumatic Shoulder Instability Caused by Sports

Outcomes of Conservative Treatment for Atraumatic Shoulder Instability Caused by Sports