Statistical shape models that predict native glenoid width based on glenoid height are inaccurate in their current form: a cross-sectional study.

BACKGROUND: The extent of measurement errors of statistical shape models that predict native glenoid width based on glenoid height to subsequently determine the amount of anterior glenoid bone loss is unclear. Therefore, the aim of this study was to (1) create a statistical shape model based on glenoid height and width measured on 3-dimensional computed tomography (3D-CT) and determine the accuracy through measurement errors and (2) determine measurement errors of existing 3D-CT statistical shape models. MATERIALS AND METHODS: A retrospective cross-sectional study included all consecutive patients who underwent CT imaging before undergoing primary surgical treatment of traumatic anterior shoulder dislocation between 2007 and 2022 at the Tohoku University Hospital and affiliated hospitals. Patients were included when instability was unilateral and CT scans of both the injured and contralateral uninjured shoulder were available. 3D segmentations were created and glenoid height and width of the injured and contralateral uninjured side (gold standard) were measured. Accuracy was determined through measurement errors, which were defined as a percentage error deviation from native glenoid width (contralateral uninjured glenoid), calculated as follows: measurement error = [(estimated glenoid width with a statistical shape model - native glenoid width) / native glenoid width] × 100%. A linear regression analysis was performed to create a statistical shape model based on glenoid height according to the formula: native glenoid width = a × glenoid height + b. RESULTS: The diagnosis and procedure codes identified 105 patients, of which 69 (66%) were eligible for inclusion. Glenoid height demonstrated a very strong correlation (r = 0.80) with native glenoid width. The linear regression formula based on this cohort was as follows: native glenoid width = 0.75 × glenoid height - 0.61, and it demonstrated an absolute average measurement error of 5% ± 4%. The formulas by Giles et al, Chen et al and Rayes et al demonstrated absolute average measurement errors of 10% ± 7%, 6% ± 5%, and 9% ± 6%, respectively. CONCLUSION: Statistical shape models that estimate native glenoid width based on glenoid height demonstrate unacceptable measurement errors, despite a high correlation. Therefore, great caution is advised when using these models to determine glenoid bone loss percentage. To minimize errors caused by morphologic differences, preference goes to methods that use the contralateral side as reference.

Elbow joint loads during simulated activities of daily living: implications for formulating recommendations after total elbow arthroplasty.

BACKGROUND: Overloading of the elbow joint prosthesis following total elbow arthroplasty can lead to implant failure. Joint moments during daily activities are not well contextualized for a prosthesis's failure limits, and the effect of the current postoperative instruction on elbow joint loading is unclear. This study investigates the difference in elbow joint moments between simulated daily tasks and between flexion-extension, pronation-supination, and varus-valgus movement directions. Additionally, the effect of the current postoperative instruction on elbow joint load is examined. METHODS: Nine healthy participants (age 45.8 ± 17 years, 3 males) performed 8 tasks; driving a car, opening a door, rising from a chair, lifting, sliding, combing hair, drinking, emptying cup, without and with the instruction "not lifting more than 1 kg." Upper limb kinematics and hand contact forces were measured. Elbow joint angles and net moments were analyzed using inverse dynamic analysis, where the net moments are estimated from movement data and external forces. RESULTS: Peak elbow joint moments differed significantly between tasks (P < .01) and movement directions (P < .01). The most and least demanding tasks were, rising from a chair (13.4 Nm extension, 5.0 Nm supination, and 15.2 Nm valgus) and sliding (4.3 Nm flexion, 1.7 Nm supination, and 2.6 Nm varus). Net moments were significantly reduced after instruction only in the chair task (P < .01). CONCLUSION: This study analyzed elbow joint moments in different directions during daily tasks. The outcomes question whether postoperative instruction can lead to decreasing elbow loads. Future research might focus on reducing elbow loads in the flexion-extension and varus-valgus directions.

Evaluating machine learning algorithms to Predict 30-day Unplanned REadmission (PURE) in Urology patients.

BACKGROUND: Unplanned hospital readmissions are serious medical adverse events, stressful to patients, and expensive for hospitals. This study aims to develop a probability calculator to predict unplanned readmissions (PURE) within 30-days after discharge from the department of Urology, and evaluate the respective diagnostic performance characteristics of the PURE probability calculator developed with machine learning (ML) algorithms comparing regression versus classification algorithms. METHODS: Eight ML models (i.e. logistic regression, LASSO regression, RIDGE regression, decision tree, bagged trees, boosted trees, XGBoost trees, RandomForest) were trained on 5.323 unique patients with 52 different features, and evaluated on diagnostic performance of PURE within 30 days of discharge from the department of Urology. RESULTS: Our main findings were that performances from classification to regression algorithms had good AUC scores (0.62-0.82), and classification algorithms showed a stronger overall performance as compared to models trained with regression algorithms. Tuning the best model, XGBoost, resulted in an accuracy of 0.83, sensitivity of 0.86, specificity of 0.57, AUC of 0.81, PPV of 0.95, and a NPV of 0.31. CONCLUSIONS: Classification models showed stronger performance than regression models with reliable prediction for patients with high probability of readmission, and should be considered as first choice. The tuned XGBoost model shows performance that indicates safe clinical appliance for discharge management in order to prevent an unplanned readmission at the department of Urology.

STUDY NEED AND IMPORTANCE: Unplanned readmissions form a consistent problem for many hospitals. Unplanned readmission rates can go up as high as to 35%, and may differ significantly between respective hospital departments. In addition, in the field of Urology readmission rates can be greatly influenced by type of surgery performed and unplanned readmissions in patients can go up as high as 26%. Although predicting unplanned readmissions for individual patients is often complex, due to multiple factors that need to be taken into account (e.g. functional disability, poor overall condition), there is evidence that these can be prevented when discharge management is evaluated with an objective measuring tool that facilitate such risk stratification between high and low risk patients. However, to the best of our knowledge, the latter risk stratification using ML driven probability calculators in the field of Urology have not been evaluated to date. Using ML, calculated risk scores based on analysing complex data patterns on patient level can support safe discharge and inform concerning the risk of having an unplanned readmission. WHAT WE FOUND: Eight ML models were trained on 5.323 unique patients with 52 different features, and evaluated on diagnostic performance. Classification models showed stronger performance than regression models with reliable prediction for patients with high probability of readmission, and should be considered as first choice. The tuned XGBoost model shows performance that indicates safe clinical appliance for discharge management in order to prevent an unplanned readmission at the department of Urology. Limitations of our study were the quality and presence of patient data on features, and how to implement these findings in clinical setting to transition from predicting to preventing unplanned readmissions. INTERPRETATION FOR CLINICIANS: ML models based on classification should be first choice to predict unplanned readmissions, and the XGBoost model showed the strongest results.

Surgical Intervention Following a First Traumatic Anterior Shoulder Dislocation Is Worthy of Consideration.

Up to 60% of patients experience recurrence after a first traumatic anterior shoulder dislocation (FTASD), which is often defined as having experienced either dislocation or subluxation. Thus surgical intervention after FTASD is worthy of consideration and is guided by the number of patients who need to receive surgical intervention to prevent 1 redislocation (i.e., number needed to treat), (subjective) health benefit, complication risk, and costs. Operative intervention through arthroscopic stabilization can be successful in reducing recurrence risk in FTASD, as has been shown in multiple randomized controlled trials. Nevertheless, there is a large "gray area" for the indication of arthroscopic stabilization, and it is therefore heavily debated which patients should receive operative treatment. Previous trials showed widely varying redislocation rates in both the intervention and control group, meta-analysis shows 2% to 19% after operative and 20% to 75% after nonoperative treatment, and redislocation rates may not correlate with patient-reported outcomes. The literature is quite heterogeneous, and a major confounder is time to follow-up. Furthermore, there is insufficient standardization of reporting of outcomes and no consensus on definition of risk factors. As a result, surgery is a reasonable intervention for FTASD patients, but in which patients it best prevents redislocation requires additional refinement.

Wide Range in Complication Rates Following Elbow Arthroscopy in Adult and Pediatric Patients: A Systematic Review.

PURPOSE: To perform a systematic review of complications associated with elbow arthroscopy in adults and children. METHODS: A literature search was performed in the PubMed, EMBASE, and Cochrane databases. Studies reporting complications or reoperations after elbow arthroscopy with at least 5 patients were included. Based on the Nelson classification, the severity of complications was categorized as minor or major. Risk of bias was assessed using the Cochrane risk-of-bias tool for randomized clinical trials, and nonrandomized trials were assessed using the Methodological Items for Non-randomized Studies (MINORS) tool. RESULT: A total of 114 articles were included with 18,892 arthroscopies (16,815 patients). A low risk of bias was seen for the randomized studies and a fair quality for the nonrandomized studies. Complication rates ranged from 0% to 71% (median 3%; 95% confidence interval [CI], 2.8%-3.3%), and reoperation rates from 0% to 59% (median 2%; 95% CI, 1.8%-2.2%). A total of 906 complications were observed, with transient nerve palsies (31%) as the most frequent complication. According to Nelson classification, 735 (81%) complications were minor and 171 (19%) major. Forty-nine studies reported complications in adults and 10 studies in children, showing a complication rate ranging from 0% to 27% (median 0%; 95% CI, 0%-0.4%) and 0% to 57% (median 1%; 95% CI, 0.4%-3.5%), respectively. A total of 125 complications were observed in adults, with transient nerve palsies (23%) as the most frequent complication, and 33 in children, with loose bodies after surgery (45%) as the most frequent complication. CONCLUSIONS: Predominantly low-level evidence studies demonstrate varying complication rates (median 3%, range 0%-71%) and reoperation rates (median 2%, range 0%-59%) after elbow arthroscopy. Higher complication rates are observed after more complex surgery. The incidence and type of complications can aid surgeons in patient counseling and refining surgical techniques to further reduce the complication rates. LEVEL OF EVIDENCE: Level IV; systematic review of Level I-IV studies.

High resorption rates following glenoid augmentation procedures do not seem to lead to higher recurrence rates or worse clinical outcomes: a systematic review and meta-analysis.

PURPOSE: Bone augmentation techniques show a relatively high complication rate, which might be due to graft non-union and resorption. It is unclear which augmentation techniques demonstrate the highest amount of non-union and resorption and whether this leads to worse clinical or functional outcomes. Therefore, the aim of this review was (i) to compare non-union and resorption rates between surgical approaches, procedures, graft types, donor sites and fixation methods regarding clinical and functional outcomes and (ii) determine whether high non-union or resorption rates lead to less favorable clinical or functional outcomes. METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses statements were followed. PubMed, EMBASE (Ovid) and Cochrane Library were searched on December 15th 2021 for studies examining bone graft non-union or resorption using radiograph or CT following glenoid augmentation to treat anterior shoulder dislocation. RESULTS: The search resulted in 103 inclusions, comprising 5,128 glenoid augmentations. When comparing pooled proportions of bony union, graft fracture rate, hardware failure rate, recurrence rate, return to sports and Rowe score, most results were similar between approaches, procedures, graft types, donor sites and fixation methods. High resorption rates were seen for allograft augmentation (74.3; 95% CI: 39.8-92.7) compared to autograft augmentation (15.5; 95% CI 10.1-23.2), but this was not associated with higher recurrence rates or worse clinical outcomes. Meta-analyses (8 studies; 494 patients) demonstrated no difference in incomplete and complete non-union rates between arthroscopic and open procedures; however, both analyses showed substantial heterogeneity. Higher partial resorption rates were observed on CT (48.0; 95% CI 43.3-52.7) compared to radiograph (14.1; 95% CI 10.9-18.1). Three studies comprising 267 shoulders demonstrated a higher rate of non-union and recurrence in smokers, whereas one study comprising 38 shoulders did not. CONCLUSION: Non-union and resorption rates were similar among procedures, grafts and fixation methods. Higher resorption rates were observed in allografts, but this was not associated with higher recurrence rates or worse clinical outcomes. Pooling data demonstrated substantial heterogeneity and definitions varied among studies, warranting more standardized measuring. LEVEL OF EVIDENCE: IV.

"Nearly off-track lesions" or a short distance from the medial edge of the Hill-Sachs lesion to the medial edge of the glenoid track does not seem to be accurate in predicting recurrence after an arthroscopic Bankart repair in a military population: a case-control study.

BACKGROUND: On-track lesions with a short distance from the medial edge of the Hill-Sachs lesion to the medial edge of the glenoid track (nearly off-track) may predispose recurrence after arthroscopic Bankart repair (ABR) in the general population. The aim of this study was to determine if a shorter distance between the medial edge of the Hill-Sachs lesion and the medial edge of the glenoid track could accurately predict recurrence after an ABR in a high-demand military population. It was hypothesized that a shorter distance would not accurately predict recurrence. MATERIALS AND METHODS: A retrospective monocenter case-control study was performed at the Dutch Central Military Hospital. Patients with an on-track Hill-Sachs lesion who underwent a primary ABR between 2014 and 2019 with a minimal follow-up of 2 years and a preoperative magnetic resonance imaging (MRI) assessment received a questionnaire. The primary outcome was recurrence, defined as a complete dislocation or subluxation. Glenoid bone loss was assessed using a linear-based method on MRI. The distance from the medial edge of the Hill-Sachs lesion to the medial edge of the glenoid track was defined as the distance to dislocation (DTD). A receiver operating characteristic curve was created to determine the predictive value of the DTD for recurrence. Logistic regression was used to determine preoperative risk factors that predispose recurrence. Covariates were selected based on univariable analysis and included gender, body mass index, age at surgery and first dislocation, laterality, smoking habits, overhead shoulder activity during work, preoperative dislocations, sports type and level, bony or labral lesions on MRI, and DTD. RESULTS: In total, 80 patients with an average follow-up of 4.8 ± 1.9 years completed the questionnaire and were included in the analyses. Seventeen patients (21%) experienced recurrence at the final follow-up. No difference in DTD was observed among patients who experienced recurrence (9 ± 4 mm) compared with patients who did not (9 ± 5 mm; P = .81). The receiver operating characteristic curve demonstrated no predictive power of DTD for recurrence (area under the curve = 0.49). Smoking at the time of surgery (odds ratio: 3.9; confidence interval: 1.2-12.7; P = .02) and overhead shoulder movement during work (odds ratio: 9.3; confidence interval: 1.1-78.0; P = .04) were associated with recurrence according to the logistic regression analysis. CONCLUSION: A shorter DTD demonstrated no accuracy in predicting recurrence in a military population. Smoking at the time of surgery and overhead shoulder activity during work were associated with recurrence; however, these analyses were underpowered to draw valid conclusions.

Prognostic factors associated with failure to return to sport following primary arthroscopic Bankart repair: a retrospective multicenter study.

BACKGROUND: Even though many studies have been published regarding return-to-sport (RTS) rates following arthroscopic Bankart repair (ABR), evidence regarding prognostic factors for which patients do not RTS is limited. The aim of this study was to identify prognostic factors that are associated with failure to RTS and failure to return to preinjury level of sport (RTPS) following primary ABR. The hypothesis was that prognostic factors for failure to RTS and failure to RTPS would be similar to those predisposing recurrence. METHODS: A multicenter, retrospective case-control study including 6 Dutch hospitals was performed. Consecutive patients who underwent primary ABR between 2014 and 2019 were invited to participate and received a questionnaire. Sports participation was assessed before symptom onset, at 6 months postoperatively, and at final follow-up. Failure to RTS was defined as no return to any sport, and failure to RTPS was defined as no return to the same level (or a higher level) of sport. Prognostic factors for failure to RTS or failure to RTPS were identified using logistic regression. Covariates for the regression analysis were selected based on univariate analyses. RESULTS: This study included 318 patients with a mean follow-up period of 4.2 years (standard deviation, 1.8 years). Of these 318 patients, 26 (8.2%) did not RTS and 100 (31%) did not RTPS. Logistic regression analysis demonstrated that glenoid bone loss (odds ratio [OR], 1.09; 95% confidence interval [CI], 1.04-1.15; P = .001) and overhead use of the shoulder during work (OR, 3.77; 95% CI, 1.45-9.85; P = .007) were prognostic factors for failure to RTS. In addition, it showed that preoperative professional sports level (OR, 2.94; 95% CI, 1.07-8.05; P = .04) and preoperative body mass index (OR, 1.11; 95% CI, 1.01-1.21; P = .04) were prognostic factors for failure to RTPS. Repair of a bony Bankart lesion (OR, 0.35; 95% CI, 0.15-0.81; P = .02) and the presence of an anterior labral periosteal sleeve avulsion (ALPSA) (OR, 0.44; 95% CI, 0.20-0.97; P = .04) were identified as factors that facilitated RTPS. CONCLUSION: This study identified glenoid bone loss and overhead use of the shoulder during work to be associated with failure to RTS. Moreover, preoperative sports level and preoperative body mass index were found to be associated with failure to RTPS. In contrast, a bony Bankart lesion and an anterior labral periosteal sleeve avulsion (ALPSA) lesion facilitated RTPS. Future prospective studies are needed to confirm these factors and determine which part of the effect can be attributed to (failure of) surgical treatment or changes in behavior.

Primary reverse total shoulder arthroplasty for fractures requires more revisions than for degenerative conditions 1 year after surgery: an analysis from the Dutch Arthroplasty Register.

BACKGROUND: Although reverse total shoulder arthroplasty (RTSA) is considered a viable treatment strategy for proximal humeral fractures, there is an ongoing discussion of how its revision rate compares with indications performed in the elective setting. First, this study evaluated whether RTSA for fractures conveyed a higher revision rate than RTSA for degenerative conditions (osteoarthritis, rotator cuff arthropathy, rotator cuff tear, or rheumatoid arthritis). Second, this study assessed whether there was a difference in patient-reported outcomes between these 2 groups following primary replacement. Finally, the results of conventional stem designs were compared with those of fracture-specific designs within the fracture group. MATERIALS AND METHODS: This was a retrospective comparative cohort study with registry data from the Netherlands, generated prospectively between 2014 and 2020. Patients (aged ≥ 18 years) were included if they underwent primary RTSA for a fracture (<4 weeks after trauma), osteoarthritis, rotator cuff arthropathy, rotator cuff tear, or rheumatoid arthritis, with follow-up until first revision, death, or the end of the study period. The primary outcome was the revision rate. The secondary outcomes were the Oxford Shoulder Score, EuroQol 5 Dimensions (EQ-5D) score, numerical rating scale score (pain at rest and during activity), recommendation score, and scores assessing change in daily functioning and change in pain. RESULTS: This study included 8753 patients in the degenerative condition group (mean age, 74.3 ± 7.2 years) and 2104 patients in the fracture group (mean age, 74.3 ± 7.8 years). RTSA performed for fractures showed an early steep decline in survivorship: Adjusted for time, age, sex, and arthroplasty brand, the revision risk after 1 year was significantly higher in these patients than in those with degenerative conditions (hazard ratio [HR], 2.50; 95% confidence interval, 1.66-3.77). Over time, the HR steadily decreased, with an HR of 0.98 at year 6. Apart from the recommendation score (which was slightly better within the fracture group), there were no clinically relevant differences in the patient-reported outcome measures after 12 months. Patients who received conventional stems (n = 1137) did not have a higher likelihood of undergoing a revision procedure than those who received fracture-specific stems (n = 675) (HR, 1.70; 95% confidence interval, 0.91-3.17). CONCLUSION: Patients undergoing primary RTSA for fractures have a substantially higher likelihood of undergoing revision within the first year following the procedure than patients with degenerative conditions preoperatively. Although RTSA is regarded as a reliable and safe treatment option for fractures, surgeons should inform patients accordingly and incorporate this information in decision making when opting for head replacement surgery. There were no differences in patient-reported outcomes between the 2 groups and no differences in revision rates between conventional and fracture-specific stem designs.

Ninety-day complication rate based on 532 Latarjet procedures in Dutch hospitals with different operation volumes.

BACKGROUND: In this study, we aimed to provide insight into the 90-day complication rates following the Latarjet procedure. Data from 2015 were collected from multiple hospitals in the Netherlands, with different volumes of Latarjet procedures. Our second aim was to examine which patient and surgical factors were associated with complications. METHODS: We conducted a retrospective chart review of 13 hospitals between 2015 and 2022. Data regarding complications within 90 days of Latarjet procedures were extracted. The effect of sex, age, body mass index (BMI), smoking, previous shoulder operations, fixation material, hospital volume, screw size, and operation time on the complication rate was assessed by multivariable logistic regression analysis. RESULTS: Of the 532 included patients, 58 (10.9%) had complications. The most common complications were material failure (n = 19, 3.6%) and nerve injury (n = 13, 2.4%). The risk of complications was lower for male patients than for female patients (odds ratio, 0.40; 95% confidence interval, 0.21-0.77; P = .006). Age, BMI, smoking, previous shoulder operations, type of fixation material, hospital volume, screw size, and operation time were not associated with complications. CONCLUSION: The 90-day complication rate after the Latarjet procedure was 10.9% and was higher in female patients than in male patients. Age, BMI, smoking, previous shoulder operations, type of fixation material, hospital volume, screw size, and operation time did not affect complication rates. We advise setting up a national registry to prevent under-reporting of complications.

Management of displaced humeral surgical neck fractures in daily clinical practice: hanging does not re-align the fracture.

INTRODUCTION: It is unclear if the collar and cuff treatment improve alignment in displaced surgical neck fractures of the proximal humerus. Therefore, this study evaluated if the neckshaft angle and extent of displacement would improve between trauma and onset of radiographically visible callus in non-operatively treated surgical neck fractures (Boileau type A, B, C). MATERIALS AND METHODS: A consecutive series of patients (≥ 18 years old) were retrospectively evaluated from a level 1 trauma center in Australia (inclusion period: 2016-2020) and a level 2 trauma center in the Netherlands (inclusion period: 2004 to 2018). Patients were included if they sustained a Boileau-type fracture and underwent initial non-operative treatment. The first radiograph had to be obtained within 24 h after the initial injury and the follow-up radiograph(s) 1 week after trauma and before the start of radiographically visible callus. On each radiograph, the maximal medial gap (MMG), maximal lateral gap (MLG), and neck-shaft angle (NSA) were measured. Linear mixed modelling was performed to evaluate if these measurements would improve over time. RESULTS: Sixty-seven patients were included: 25 type A, 11 type B, and 31 type C fractures. The mean age (range) was 68 years (24-93), and the mean number (range) of follow-up radiographs per patient was 1 (1-4). Linear mixed modelling on both MMG and MLG revealed no improvement during follow-up among the three groups. Mean NSA of type A fractures improved significantly from 161° at trauma to 152° at last follow-up (p-value = 0.004). CONCLUSIONS: Apart from humeral head angulation improvement in type A, there is no increase nor reduction in displacement among the three fracture patterns. Therefore, it is advised that surgical decision-making should be performed immediately after trauma. LEVEL OF CLINICAL EVIDENCE: Level IV, retrospective case series.

3D-printed Handheld Models Do Not Improve Recognition of Specific Characteristics and Patterns of Three-part and Four-part Proximal Humerus Fractures.

BACKGROUND: Reliably recognizing the overall pattern and specific characteristics of proximal humerus fractures may aid in surgical decision-making. With conventional onscreen imaging modalities, there is considerable and undesired interobserver variability, even when observers receive training in the application of the classification systems used. It is unclear whether three-dimensional (3D) models, which now can be fabricated with desktop printers at relatively little cost, can decrease interobserver variability in fracture classification. QUESTIONS/PURPOSES: Do 3D-printed handheld models of proximal humerus fractures improve agreement among residents and attending surgeons regarding (1) specific fracture characteristics and (2) patterns according to the Neer and Hertel classification systems? METHODS: Plain radiographs, as well as two-dimensional (2D) and 3D CT images, were collected from 20 patients (aged 18 years or older) who sustained a three-part or four-part proximal humerus fracture treated at a Level I trauma center between 2015 and 2019. The included images were chosen to comprise images from patients whose fractures were considered as difficult-to-classify, displaced fractures. Consequently, the images were assessed for eight fracture characteristics and categorized according to the Neer and Hertel classifications by four orthopaedic residents and four attending orthopaedic surgeons during two separate sessions. In the first session, the assessment was performed with conventional onscreen imaging (radiographs and 2D and 3D CT images). In the second session, 3D-printed handheld models were used for assessment, while onscreen imaging was also available. Although proximal humerus classifications such as the Neer classification have, in the past, been shown to have low interobserver reliability, we theorized that by receiving direct tactile and visual feedback from 3D-printed handheld fracture models, clinicians would be able to recognize the complex 3D aspects of classification systems reliably. Interobserver agreement was determined with the multirater Fleiss kappa and scored according to the categorical rating by Landis and Koch. To determine whether there was a difference between the two sessions, we calculated the delta (difference in the) kappa value with 95% confidence intervals and a two-tailed p value. Post hoc power analysis revealed that with the current sample size, a delta kappa value of 0.40 could be detected with 80% power at alpha = 0.05. RESULTS: Using 3D-printed models in addition to conventional imaging did not improve interobserver agreement of the following fracture characteristics: more than 2 mm medial hinge displacement, more than 8 mm metaphyseal extension, surgical neck fracture, anatomic neck fracture, displacement of the humeral head, more than 10 mm lesser tuberosity displacement, and more than 10 mm greater tuberosity displacement. Agreement regarding the presence of a humeral head-splitting fracture was improved but only to a level that was insufficient for clinical or scientific use (fair to substantial, delta kappa = 0.33 [95% CI 0.02 to 0.64]). Assessing 3D-printed handheld models adjunct to onscreen conventional imaging did not improve the interobserver agreement for pattern recognition according to Neer (delta kappa = 0.02 [95% CI -0.11 to 0.07]) and Hertel (delta kappa = 0.01 [95% CI -0.11 to 0.08]). There were no differences between residents and attending surgeons in terms of whether 3D models helped them classify the fractures, but there were few differences to identify fracture characteristics. However, none of the identified differences improved to almost perfect agreement (kappa value above 0.80), so even those few differences are unlikely to be clinically useful. CONCLUSION: Using 3D-printed handheld fracture models in addition to conventional onscreen imaging of three-part and four-part proximal humerus fractures does not improve agreement among residents and attending surgeons on specific fracture characteristics and patterns. Therefore, we do not recommend that clinicians expend the time and costs needed to create these models if the goal is to classify or describe patients' fracture characteristics or pattern, since doing so is unlikely to improve clinicians' abilities to select treatment or estimate prognosis. LEVEL OF EVIDENCE: Level III, diagnostic study.

Recurrence in traumatic anterior shoulder dislocations increases the prevalence of Hill-Sachs and Bankart lesions: a systematic review and meta-analysis.

PURPOSE: The extent of shoulder instability and the indication for surgery may be determined by the prevalence or size of associated lesions. However, a varying prevalence is reported and the actual values are therefore unclear. In addition, it is unclear whether these lesions are present after the first dislocation and whether or not these lesions increase in size after recurrence. The aim of this systematic review was (1) to determine the prevalence of lesions associated with traumatic anterior shoulder dislocations, (2) to determine if the prevalence is higher following recurrent dislocations compared to first-time dislocations and (3) to determine if the prevalence is higher following complete dislocations compared to subluxations. METHODS: PubMed, EMBASE, Cochrane and Web of Science were searched. Studies examining shoulders after traumatic anterior dislocations during arthroscopy or with MRI/MRA or CT published after 1999 were included. A total of 22 studies (1920 shoulders) were included. RESULTS: The proportion of Hill-Sachs and Bankart lesions was higher in recurrent dislocations (85%; 66%) compared to first-time dislocations (71%; 59%) and this was statistically significant (P < 0.01; P = 0.05). No significant difference between recurrent and first-time dislocations was observed for SLAP lesions, rotator-cuff tears, bony Bankart lesions, HAGL lesions and ALPSA lesions. The proportion of Hill-Sachs lesions was significantly higher in complete dislocations (82%) compared to subluxations (54%; P < 0.01). CONCLUSION: Higher proportions of Hill-Sachs and Bankart were observed in recurrent dislocations compared to first-time dislocations. No difference was observed for bony Bankart, HAGL, SLAP, rotator-cuff tear and ALPSA. Especially when a Hill-Sachs or Bankart is present after first-time dislocation, early surgical stabilization may need to be considered as other lesions may not be expected after recurrence and to limit lesion growth. However, results should be interpreted with caution due to substantial heterogeneity and large variance. LEVEL OF EVIDENCE: IV.

Evaluation of MRI Signal Changes of the Distal Biceps Tendon in Asymptomatic Patients.

PURPOSE: Magnetic resonance imaging (MRI) is used widely for complete ruptures of the distal biceps tendon. The validity of this investigation for bicipital bursitis and tendinosis is unknown. The purpose of present study was to assess the prevalence of incidental (asymptomatic) signal changes in the distal biceps tendon in patients who underwent MRI including the elbow. Our null hypothesis was that signal changes of the distal biceps tendon do not occur in asymptomatic patients. This would empower MRI as a diagnostic tool for bicipital bursitis and tendinosis as well as complete and partial distal biceps tendon ruptures. METHODS: We evaluated 1,191 elbow MRI scans including the distal biceps tendon insertion. The prevalence of incidental findings was calculated and sensitivity, specificity, positive predictive value, negative predictive value, false positive probability, and false negative probability were calculated. RESULTS: Signal changes of the distal biceps tendon or bursitis were identified in 8 of 1,191 asymptomatic patients (prevalence 0.6%). The sensitivity of MRI for distal biceps pathology was 97% (95% confidence interval [CI], 93%-99%), specificity 99% (95% CI, 98%-99%), positive predictive value 94% (95% CI, 89%-97%), negative predictive value 99% (95% CI, 99%-99%), false positive probability 6% (95% CI, 3%-10%), and false negative probability 0.3% (95% CI, 0.1%-0.9%). There was no correlation between explanatory variables, including age, sex, race, occupation, and inflammatory disease and incidental distal biceps tendon signal changes. CONCLUSIONS: The prevalence of distal biceps tendon signal changes on MRI in asymptomatic patients is very low. CLINICAL RELEVANCE: The negative predictive value of 99% shows that patients without signal changes on MRI may be assumed to have no distal biceps tendon pathology. MRI investigation of distal biceps tendon is a valuable tool in the diagnosis of tendinosis and bicipital bursitis.

Evaluation of clinical tests for partial distal biceps tendon ruptures and tendinitis.

BACKGROUND: The clinical diagnosis of partial distal biceps tendon ruptures or tendinosis can be challenging. Three clinical tests have been described to aid in an accurate and timely diagnosis: biceps provocation test, tilt sign, and resisted hook test. However, not much is known about the sensitivity, specificity, and inter-rater reliability as the available evaluations are based on small groups or are case based. Furthermore, these tests have not been compared together in the same patient group. METHODS: Two dedicated elbow surgeons each included 20 consecutive patients in whom distal biceps tendon pathology was suspected. Patients with a complete distal biceps tendon tear were excluded. As a control, the same number of consecutive patients with various elbow pathologies other than distal biceps tendon problems was included. All 3 tests were performed both in control patients and in patients with suspected biceps tendon pathology. Magnetic resonance imaging (MRI) in the flexion-abduction-supination view and/or surgical exploration was performed in both groups. The findings of the clinical tests were determined before the results of MRI and other technical investigations were analyzed. The values of sensitivity, specificity, and accuracy were calculated. RESULTS: The combined sensitivity, specificity, and accuracy values for the biceps provocation test were 95%, 97%, and 96%, respectively. For the resisted hook test, the combined values were 78%, 76%, and 77%, respectively. The combined values for the tilt sign were 58%, 55%, and 56%, respectively. When the biceps provocation test and the resisted hook test were combined in a parallel testing setup, the sensitivity increased to 98% whereas the specificity was 73%. The sensitivity and specificity of the biceps provocation test and the tilt sign in a parallel testing setup were 97% and 53%, respectively. Finally, the sensitivity and specificity of the tilt sign and the resisted hook test in a parallel testing setup were 90% and 41%, respectively. CONCLUSIONS: The biceps provocation test yielded higher accuracy than the resisted hook test and the tilt sign. When the biceps provocation test and the resisted hook test were combined, the sensitivity increased to 98%. We advise integration of these tests in daily practice to minimize delays in the diagnosis of partial distal biceps tendon ruptures, distal biceps tendon bursitis, or tendinosis. MRI in the flexion-abduction-supination view is still advised to distinguish between a partial biceps tendon rupture and tendinosis or bursitis at the distal biceps tendon insertion as this may influence further treatment.

Bony reconstruction after failed labral repair is associated with higher recurrence rates compared to primary bony reconstruction: a systematic review and meta-analysis of 1319 shoulders in studies with a minimum of 2-year follow-up.

BACKGROUND: There is uncertainty with regard to the optimal revision procedure after failed labral repair for anterior shoulder instability. An overview of outcomes of these procedures with quantitative analysis is not available in literature. The aim of this review is (1) to compare recurrence rates after revision labral repair (RLR) and revision bony reconstruction (RBR), both following failed labral repair. In addition, (2) recurrence rates after RBR following failed labral repair and primary bony reconstruction (PBR) are compared to determine if a previous failed labral repair influences the outcomes of the bony reconstruction. METHODS: Randomized controlled trials and cohort studies with a minimum follow-up of 2 years and reporting recurrence rates of (1) RBR following failed labral repair and PBR and/or (2) RLR following failed labral repair and RBR following failed labral repair were identified by searching PubMed, Embase/Ovid, Cochrane Database of Systematic Reviews/Wiley, Cochrane Central Register of Controlled Trials/Wiley, and Web of Science/Clarivate Analytics. RESULTS: Thirteen studies met the inclusion criteria and comprised 1319 shoulders. Meta-analyses showed that RBR has a significantly higher recurrence rate than PBR (risk ratio [RR] 0.51, P < .008) but found no significant difference in the recurrence rates for RLR and RBR (RR 1.40, P < .49). Also, no significant differences were found between PBR and RBR in return to sport (RR 1.07, P < .41), revision surgery (RR 0.8, P < .44), and complications (RR 0.84, P < .53). Lastly, no significant differences between RLR and RBR for revision surgery (RR 3.33, P < .19) were found. CONCLUSION: The findings of this meta-analyses show that (1) RBR does not demonstrate a significant difference in recurrence rates compared with RLR and that (2) RBR has a significantly higher recurrence rate than PBR.

Long Head of Biceps Tenotomy Is Not Inferior to Suprapectoral Tenodesis in Arthroscopic Repair of Nontraumatic Rotator Cuff Tears: A Multicenter, Non-inferiority, Randomized, Controlled Clinical Trial.

PURPOSE: To determine if long head of the biceps (LHB) tenotomy is not inferior to suprapectoral LHB tenodesis when performed in conjunction with arthroscopic repair of small- to medium-sized nontraumatic rotator cuff tears. METHODS: This multicenter, randomized, non-inferiority trial recruited 100 participants older than 50 years who had a supraspinatus and/or infraspinatus tear sagittally smaller than 3 cm and arthroscopically confirmed LHB pathology. During arthroscopic rotator cuff repair, we randomized 48 patients to undergo suprapectoral LHB tenodesis and 52 patients to undergo LHB tenotomy. Data were collected preoperatively and at 6 weeks, 3 months, and 1 year postoperatively. The primary outcome was non-inferiority of the Constant-Murley score (CMS) at 1-year follow-up. Secondary outcomes included the Dutch Oxford Shoulder Score; Disabilities of the Arm, Shoulder and Hand questionnaire; Popeye deformity; elbow flexion strength index; arm cramping pain; and quality of life (EQ-5D score). The integrity of the rotator cuff repair was assessed with magnetic resonance imaging. Differences between intervention groups were analyzed by mixed modeling. RESULTS: The mean CMS in the LHB tenotomy group improved from 44 (95% confidence interval [CI], 39-48) to 73 (95% CI, 68-79). In patients with LHB tenodesis, the mean CMS improved from 42 (95% CI, 37-48) to 78 (95% CI, 74-82). The difference between groups at 1-year follow-up was 4.8 (97.5% CI, -∞ to 11.4), with a P value for non-inferiority of .06. The secondary outcomes also improved over time, with no remarkable differences between groups. A Popeye deformity occurred in 33% of tenodesis patients and 47% of tenotomy patients (P = .17). Tenotomy was performed with a shorter operative time (73 minutes vs 82 minutes, P = .03). Magnetic resonance imaging showed a recurrent rotator cuff tear in 20% of all cases. CONCLUSIONS: Although statistically "inconclusive" regarding non-inferiority of the CMS at 1-year follow-up, any observed differences between patients with LHB tenotomy and those with LHB tenodesis in all outcome scores were small. LEVEL OF EVIDENCE: Level I, randomized controlled trial and treatment study.

Treatment type may influence degree of post-dislocation shoulder osteoarthritis: a systematic review and meta-analysis.

PURPOSE: Age at primary dislocation, recurrence, and glenoid bone loss are associated with development of osteoarthritis (OA). However, an overview of OA following traumatic anterior shoulder instability is lacking and it is unclear to what degree type of surgery is associated with development of OA in comparison to non-operative treatment. The aim of this study was to determine the degree of OA at long-term follow-up after non-operative and operative treatments for patients with anterior shoulder instability. Surgery is indicated when patients experience recurrence and this is associated with OA; therefore, it was hypothesized that shoulders show a higher proportion or degree of OA following operative treatment compared to non-operative treatment. METHODS: A literature search was performed in the PubMed/Medline, EMBASE, and Cochrane databases. Articles reporting the degree of OA that was assessed with the Samilson-Prieto or Buscayret OA classification method after non-operative and operative treatment for anterior shoulder instability with a minimum of 5 years follow-up were included. RESULTS: Thirty-six articles met the eligibility criteria of which 1 reported the degree of OA for non-operative treatment and 35 reported the degree of OA for 9 different operative procedures. A total of 1832 patients (1854 shoulders) were included. OA proportions of non-operative and operative treatments are similar at any point of follow-up. The Latarjet procedure showed a lower degree of OA compared to non-operative treatment and the other operative procedures, except for the Bristow procedure and Rockwood capsular shift. The meta-analyses showed comparable development of OA over time among the treatment options. An increase in OA proportion was observed when comparing the injured to the contralateral shoulder. However, a difference between the operative subgroups was observed in neither analysis. CONCLUSION: Non-operative and operative treatments show similar OA proportions at any point of follow-up. The hypothesis that shoulders showed a higher proportion or degree of OA following operative treatment compared to non-operative treatment is not supported by the data. Operative treatment according to the Latarjet procedure results in a lower degree of OA compared to other treatments, including non-operative treatment. LEVEL OF EVIDENCE: IV.

Age, participation in competitive sports, bony lesions, ALPSA lesions, > 1 preoperative dislocations, surgical delay and ISIS score > 3 are risk factors for recurrence following arthroscopic Bankart repair: a systematic review and meta-analysis of 4584 shoulders.

PURPOSE: Determining the risk of recurrent instability following an arthroscopic Bankart repair can be challenging, as numerous risk factors have been identified that might predispose recurrent instability. However, an overview with quantitative analysis of all available risk factors is lacking. Therefore, the aim of this systematic review is to identify risk factors that are associated with recurrence following an arthroscopic Bankart repair. METHODS: Relevant studies were identified by searching PubMed, Embase/Ovid, Cochrane Database of Systematic Reviews/Wiley, Cochrane Central Register of Controlled Trials/Wiley, CINAHL/Ebsco, and Web of Science/Clarivate Analytics from inception up to November 12th 2020. Studies evaluating risk factors for recurrence following an arthroscopic Bankart repair with a minimal follow-up of 2 years were included. RESULTS: Twenty-nine studies met the inclusion criteria and comprised a total of 4582 shoulders (4578 patients). Meta-analyses were feasible for 22 risk factors and demonstrated that age ≤ 20 years (RR = 2.02; P < 0.00001), age ≤ 30 years (RR = 2.62; P = 0.005), participation in competitive sports (RR = 2.40; P = 0.02), Hill-Sachs lesion (RR = 1.77; P = 0.0005), off-track Hill-Sachs lesion (RR = 3.24; P = 0.002), glenoid bone loss (RR = 2.38; P = 0.0001), ALPSA lesion (RR = 1.90; P = 0.03), > 1 preoperative dislocations (RR = 2.02; P = 0.03), > 6 months surgical delay (RR = 2.86; P < 0.0001), ISIS > 3 (RR = 3.28; P = 0.0007) and ISIS > 6 (RR = 4.88; P < 0.00001) were risk factors for recurrence. Male gender, an affected dominant arm, hyperlaxity, participation in contact and/or overhead sports, glenoid fracture, SLAP lesion with/without repair, rotator cuff tear, > 5 preoperative dislocations and using ≤ 2 anchors could not be confirmed as risk factors. In addition, no difference was observed between the age groups ≤ 20 and 21-30 years. CONCLUSION: Meta-analyses demonstrated that age ≤ 20 years, age ≤ 30 years, participation in competitive sports, Hill-Sachs lesion, off-track Hill-Sachs lesion, glenoid bone loss, ALPSA lesion, > 1 preoperative dislocations, > 6 months surgical delay from first-time dislocation to surgery, ISIS > 3 and ISIS > 6 were risk factors for recurrence following an arthroscopic Bankart repair. These factors can assist clinicians in giving a proper advice regarding treatment. LEVEL OF EVIDENCE: Level IV.

The Popeye sign: a doctor's and not a patient's problem.

BACKGROUND: The Popeye sign is a frequently reported finding following long head of the biceps (LHB) surgery and may be more often detected by doctors than by patients. This study investigates agreement between patients and doctors regarding the presence of a Popeye sign following LHB surgery. METHOD: This interobserver study investigates agreement between patients and consulting physicians with regard to assessment of a Popeye sign in patients following LHB surgery. Furthermore, this was compared with assessments by non-consulting physicians (observers) using digital photographs of the operated arm, taken both preoperatively and postoperatively. Data about gender, age, and body mass index (BMI) were collected to investigate their role in doctor's reporting of a Popeye sign. Patient's dissatisfaction with a Popeye sign in the operated arm was evaluated as well. RESULTS: Ninety-seven patients (mean age 61 ± 6.0 years, 62% male) underwent LHB surgery. A Popeye sign was reported by 2 patients (2%) as opposed to 32 cases (40%) by consulting physicians, of which only 1 case was in agreement. Krippendorff's alpha (Kalpha) for agreement between observers for preoperative photographs was 0.074 (95% CI -0.277, 0.382) and 0.495 (95% CI 0.317, 0.659) for postoperative cases. Kalpha between observers and consulting physicians for pre- and postoperative cases were 0.033 (95% CI -970, 0.642) and 0.499 (95% CI 0.265, 0.699), respectively. Phi coefficient analysis showed a moderate, statistically significant correlation between male sex and Popeye sign identification. Rank-biserial calculation revealed negligible correlation between BMI and age with regard to detecting a Popeye sign by both consulting physicians and observers. Dissatisfaction about swelling in the upper arm was reported in 1 case, though in a location that did not correspond to the location of a Popeye sign. CONCLUSION: The Popeye sign is more often identified by doctors than by patients after undergoing LHB surgery. BMI and age are not related to the detection of a Popeye sign, but sex is moderately correlated. Together with the low percentage of dissatisfaction of patients with this swelling, this signifies that a Popeye sign seems to be a doctor's rather than a patient's problem.