The Kappa Paradox Explained.

Observer reliability studies for fracture classification systems evaluate agreement using Cohen's κ and absolute agreement as outcome measures. Cohen's κ is a chance-corrected measure of agreement and can range between 0 (no agreement) and 1 (perfect agreement). Absolute agreement is the percentage of times observers agree on the matter they have to rate. Some studies report a high-absolute agreement but a relatively low κ value, which is counterintuitive. This phenomenon is referred to as the Kappa Paradox. The objective of this article was to explain the statistical phenomenon of the Kappa Paradox and to help readers and researchers to recognize and prevent this phenomenon.

Nonoperatively Treated Proximal Humerus Fractures: Randomized Trial of Immediate Versus Delayed Initiation of Exercises.

Objectives: There is debate about when to start exercises in the nonoperative treatment of a proximal humerus fracture. This randomized trial compared immediate and one-month delayed shoulder exercises in the nonoperative treatment of fractures of the proximal humerus. Methods: Twenty-six patients with a fracture of the proximal humerus who chose nonoperative treatment were randomized to start pendulum exercises within a few days and 24 were randomized to delayed exercises and started with active self-assisted stretching 1 month after fracture. Three and six months after the injury, patients completed the Disabilities of the Arm Shoulder and Hand questionnaire to measure capability, a measure of pain intensity, and had motion measurements. Results: There was no significant difference in forward flexion (primary outcome) six months after injury between patients that started motion exercises immediately compared to 1 month after injury (p = 0.85). There was no difference in any motion measurement, pain intensity, upper extremity specific disability (DASH score) three or six months after injury. Conclusion: Delaying exercises for a month does not affect recovery from nonoperative treatment of a fracture of the proximal humerus. People can choose whether to start exercises immediately or wait until they feel comfortable.

Variation in Treatment for Trapeziometacarpal Arthrosis.

BACKGROUND: Treatment recommendations for trapeziometacarpal (TMC) arthrosis are highly variable from surgeon to surgeon. This study addressed the influence of viewing radiographs on a decision to offer surgery for TMC arthrosis. METHODS: In an online survey, 92 hand surgeons viewed clinical scenarios and were asked if they would offer surgery to 30 patients with TMC arthrosis. Forty-two observers were randomly assigned to review clinical information alone and 50 to review clinical information as well as radiographs. The degree of limitation of daily activities, time since diagnosis, prior treatment, pain with grind, crepitation with grind, and metacarpal adduction with metacarpophalangeal hyperextension were randomized for each patient scenario to determine the influence of these factors on offers of surgery. A cross-classified binary logistic multilevel regression analysis identified factors associated with surgeon offer of surgery. RESULTS: Surgeons were more likely to offer surgery when they viewed radiographs (42% vs. 32%, P = 0.01). Other factors associated variation in offer of surgery included greater limitation of daily activities, symptoms for a year, prior splint or injection, deformity of the metacarpophalangeal joint. Factors not associated included limb dominance, prominence of the TMC joint, crepitation with the grind test, and pinch and grip strength. CONCLUSION: Surgeons that view radiographs are more likely to offer surgery to people with TMC arthrosis. urgeons are also more likely to offer surgery when people do not adapt with time and nonoperative treatment. Given the notable influence of surgeon bias, and the potential for surgeon and patient impatience with the adaptation process, methods for increasing patient participation in the decision-making process merit additional attention and study.

Interobserver Agreement of the Eaton-Glickel Classification for Trapeziometacarpal and Scaphotrapezial Arthrosis.

PURPOSE: To determine whether simplification of the Eaton-Glickel (E-G) classification of trapeziometacarpal (TMC) joint arthrosis (eliminating evaluation of the scaphotrapezial [ST] joint) and information about the patient's symptoms and examination influence interobserver reliability. We also tested the null hypotheses that no patient and/or surgeon factors affect radiographic rating of TMC joint arthrosis and that no surgeon factors affect the radiographic rating of ST joint arthrosis. METHODS: In an on-line survey, 92 hand surgeons rated TMC joint arthrosis and ST joint arthrosis separately on 30 radiographs (Robert, true lateral, and oblique views) according to the (modified) E-G classification. We randomly assigned 42 observers to review radiographs alone and also informed 50 of the patient's symptoms and examination. Information about symptoms and examination was randomized. Interobserver reliability was determined with the s* statistic. Because of the hierarchical data structure, cross-classified ordinal multilevel regression analyses were performed to identify factors associated with the severity of arthrosis. RESULTS: Shortening the E-G classification to the first 3 stages significantly improved the interobserver reliability, which approached substantial agreement. Providing clinical information to observers marginally improved interobserver reliability. Factors associated with a lower E-G stage for TMC joint arthrosis, among observers who rated the severity of TMC joint arthrosis based on radiographs and clinical information, included female surgeon, practice setting, supervising surgical trainees in the operating room, self-reported number of patients with TMC joint arthrosis typically treated annually, male patient, higher patient age, pain limiting daily activities, and shoulder sign. A self-reported larger number of patients with TMC joint arthrosis treated annually was the only variable associated with a higher modified E-G classification to rate ST joint arthrosis. CONCLUSIONS: Our findings suggest that simpler classifications that focus on a single anatomical area are reliable and that surgeon and patient factors can bias interpretation of objective pathophysiology such as radiographic findings. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic III.

How prevalent are hazardous attitudes among orthopaedic surgeons?

BACKGROUND: So-called "hazardous attitudes" (macho, impulsive, antiauthority, resignation, invulnerable, and confident) were identified by the Federal Aviation Administration and the Canadian Air Transport Administration as contributing to road traffic incidents among college-aged drivers and felt to be useful for the prevention of aviation accidents. The concept of hazardous attitudes may also be useful in understanding adverse events in surgery, but it has not been widely studied. QUESTIONS/PURPOSES: We surveyed a cohort of orthopaedic surgeons to determine the following: (1) What is the prevalence of hazardous attitudes in a large cohort of orthopaedic surgeons? (2) Do practice setting and/or demographics influence variation in hazardous attitudes in our cohort of surgeons? (3) Do surgeons feel they work in a climate that promotes patient safety? METHODS: We asked the members of the Science of Variation Group-fully trained, practicing orthopaedic and trauma surgeons from around the world-to complete a questionnaire validated in college-aged drivers measuring six attitudes associated with a greater likelihood of collision and used by pilots to assess and teach aviation safety. We accepted this validation as applicable to surgeons and modified the questionnaire accordingly. We also asked them to complete the Modified Safety Climate Questionnaire, a questionnaire assessing the absence of a safety climate that is based on the patient safety cultures in healthcare organizations instrument. Three hundred sixty-four orthopaedic surgeons participated, representing a 47% response rate of those with correct email addresses who were invited. RESULTS: Thirty-eight percent (137 of 364 surgeons) had at least one score that would have been considered dangerously high in pilots (> 20), including 102 with dangerous levels of macho (28%) and 41 with dangerous levels of self-confidence (11%). After accounting for possible confounding variables, the variables most closely associated with a macho attitude deemed hazardous in pilots were supervision of surgical trainees in the operating room (p = 0.003); location of practice in Canada (p = 0.059), Europe (p = 0.021), and the United States (p = 0.005); and being an orthopaedic trauma surgeon (p = 0.046) (when compared with general orthopaedic surgeons), but accounted for only 5.3% of the variance (p < 0.001). On average, 19% of surgeon responses to the Modified Safety Climate Questionnaire implied absence of a safety climate. CONCLUSIONS: Hazardous attitudes are common among orthopaedic surgeons and relate in small part to demographics and practice setting. Future studies should further validate the measure of hazardous attitudes among surgeons and determine if they are associated with preventable adverse events. We agree with aviation safety experts that awareness of amelioration of such attitudes might improve safety in all complex, high-risk endeavors, including surgery-a line of thinking that merits additional research.

A randomized controlled trial of nonoperative treatment versus open reduction and internal fixation for stable, displaced, partial articular fractures of the radial head: the RAMBO trial.

BACKGROUND: The choice between operative or nonoperative treatment is questioned for partial articular fractures of the radial head that have at least 2 millimeters of articular step-off on at least one radiograph (defined as displaced), but less than 2 millimeter of gap between the fragments (defined as stable) and that are not associated with an elbow dislocation, interosseous ligament injury, or other fractures. These kinds of fractures are often classified as Mason type-2 fractures. Retrospective comparative studies suggest that operative treatment might be better than nonoperative treatment, but the long-term results of nonoperative treatment are very good. Most experts agree that problems like reduced range of motion, painful crepitation, nonunion or bony ankylosis are infrequent with both nonoperative and operative treatment of an isolated displaced partial articular fracture of the radial head, but determining which patients will have problems is difficult. A prospective, randomized comparison would help minimize bias and determine the balance between operative and nonoperative risks and benefits. METHODS/DESIGN: The RAMBO trial (Radial Head - Amsterdam - Amphia - Boston - Others) is an international prospective, randomized, multicenter trial. The primary objective of this study is to compare patient related outcome defined by the 'Disabilities of Arm, Shoulder and Hand (DASH) score' twelve months after injury between operative and nonoperative treated patients. Adult patients with partial articular fractures of the radial head that comprise at least 1/3rd of the articular surface, have ≥ 2 millimeters of articular step-off but less than 2 millimeter of gap between the fragments will be enrolled. Secondary outcome measures will be the Mayo Elbow Performance Index (MEPI), the Oxford Elbow Score (OES), pain intensity through the 'Numeric Rating Scale', range of motion (flexion arc and rotational arc), radiographic appearance of the fracture (heterotopic ossification, radiocapitellar and ulnohumeral arthrosis, fracture healing, and signs of implant loosening or breakage) and adverse events (infection, nerve injury, secondary interventions) after one year. DISCUSSION: The successful completion of this trial will provide evidence on the best treatment for stable, displaced, partial articular fractures of the radial head. TRIAL REGISTRATION: The trial is registered at the Dutch Trial Register: NTR3413.

Radiographic loss of contact between radial head fracture fragments is moderately reliable.

BACKGROUND: Loss of contact between radial head fracture fragments is strongly associated with other elbow or forearm injuries. If this finding has adequate interobserver reliability, it could help examiners identify and treat associated ligament injuries and fractures (eg, forearm interosseous ligament injury or elbow dislocation). QUESTIONS/PURPOSES: (1) What is the interobserver agreement on radiographic loss of contact between radial head fracture fragments? (2) Are there factors associated with the observer such as location of practice or subspecialization that increase interobserver reliability? METHODS: Fully trained practicing orthopaedic and trauma surgeons from around the world evaluated 27 anteroposterior and lateral radiographs of radial head fractures on a web-based platform for the following characteristics: (1) loss of contact between at least one radial head fracture fragment and the remaining radial head and neck; (2) a gap between fragments of 2 mm or greater; (3) anticipated fracture instability (mobility) on operative exposure; (4) anticipated associated ligament injuries; and (5) recommendation for treatment. Agreement among observers was measured using the multirater kappa measure. Kappas for various observer characteristics were compared using 95% confidence intervals. RESULTS: The overall interobserver agreement was moderate (range, 0.49-0.55) for each question except associated ligament injury, which was fair (0.33). Shoulder and elbow surgeons had substantial agreement (range, 0.51-0.61) in many areas, but kappas were generally in the moderate range (0.41-0.59) based on number of years in practice, radial head fractures treated per year, and trainee supervision. CONCLUSIONS: Radiographic signs of radial head fracture instability such as loss of contact have moderate reliability. This characteristic seems clinically useful, because loss of contact between at least one radial head fracture fragment and the remaining radial head and neck is strongly associated with associated ligament injury or other fractures. LEVEL OF EVIDENCE: Level III, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

Complications of hinged external fixation compared with cross-pinning of the elbow for acute and subacute instability.

BACKGROUND: Elbows that are unstable after injury or reconstructive surgery often are stabilized using external fixation or cross-pinning of the joint supplemented by cast immobilization. The superiority of one approach or the other remains a matter of debate. QUESTIONS/PURPOSES: We compared patients treated with external fixation or cross-pinning in terms of (1) adverse events, (2) Broberg and Morrey scores, and (3) ROM. METHODS: Between 1998 and 2010, 19 patients (19 elbows) had hinged external fixation and 10 patients (11 elbows) cross-pinning and casting for subacute or acute posttraumatic elbow instability. Our general indications for both techniques were persistent elbow instability after usual treatment. Initially, we used external fixation for delayed treatment of fracture-dislocations and cross-pinning for simple elbow dislocations in patients who could not tolerate surgery, but more recently we have used cross-pinning for both indications. Adverse events, elbow scores, and ROM were retrospectively evaluated by chart review, with the latter two end points being calculated at a mean of 31 months (range, 5-83 months) and 10 months (range, 5-21 months) after index procedure for the patients treated with external fixation and cross-pinning, respectively. RESULTS: Seven of 19 patients treated with external fixation experienced nine device-related adverse events: three pin tract infections, two nerve problems, one broken pin, one residual subluxation, one suture abscess, and one pin tract fracture of the ulna resulting in a nonunion. Of the 10 patients (11 elbows) treated with cross-pinning, one patient had pin tract inflammation that resolved with pin removal. Mean Broberg and Morrey score was 90 (95% CI, 84-95) after external fixation and 90 (95% CI, 84-96) after cross-pinning (p = 0.88). There were no differences between the external fixation and cross-pinning groups in mean flexion (123° versus 128°, p = 0.49), extension (29° versus 29°, p = 0.97), forearm pronation (68° versus 74°, p = 0.56), and forearm supination (47° versus 68°, p = 0.15). CONCLUSIONS: When the elbow remains unstable after reduction and usual treatment for fractures and dislocations or has been out of place for more than 2 weeks, both cross-pinning and external fixation can help maintain elbow alignment while structures heal. Hinged external fixation is associated with more adverse events related to the device, but Broberg and Morrey score and ROM are similar between techniques. LEVEL OF EVIDENCE: Level III, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Manifestations and treatment of the hand in adult congenital erythropoietic porphyria.

Congenital erythropoietic porphyria (CEP) is a rare enzymatic disorder of heme metabolism, leading to the accumulation of porphyrins in the skin and subdermal structures. We present the case of a 34-year-old, right-hand-dominant, male patient with CEP. The patient had developed a chronic open subluxation of the left index finger proximal interphalangeal joint due to skin necrosis. We successfully treated the patient with proximal interphalangeal arthrodesis. This case demonstrates that childhood-onset CEP can also manifest in the adult hand. Considering the patient's age, the destructive nature of the disease, and the poor quality of function in older patients with childhood CEP, surgical intervention was necessary to avoid further digital length loss. Although the treatment described in this case report is not uncommon, we found it essential to present this case because the clinical presentation of CEP is rare.

Interobserver reliability of classification and characterization of proximal humeral fractures: a comparison of two and three-dimensional CT.

BACKGROUND: Interobserver reliability for the classification of proximal humeral fractures is limited. The aim of this study was to test the null hypothesis that interobserver reliability of the AO classification of proximal humeral fractures, the preferred treatment, and fracture characteristics is the same for two-dimensional (2-D) and three-dimensional (3-D) computed tomography (CT). METHODS: Members of the Science of Variation Group--fully trained practicing orthopaedic and trauma surgeons from around the world--were randomized to evaluate radiographs and either 2-D CT or 3-D CT images of fifteen proximal humeral fractures via a web-based survey and respond to the following four questions: (1) Is the greater tuberosity displaced? (2) Is the humeral head split? (3) Is the arterial supply compromised? (4) Is the glenohumeral joint dislocated? They also classified the fracture according to the AO system and indicated their preferred treatment of the fracture (operative or nonoperative). Agreement among observers was assessed with use of the multirater kappa (κ) measure. RESULTS: Interobserver reliability of the AO classification, fracture characteristics, and preferred treatment generally ranged from "slight" to "fair." A few small but statistically significant differences were found. Observers randomized to the 2-D CT group had slightly but significantly better agreement on displacement of the greater tuberosity (κ = 0.35 compared with 0.30, p < 0.001) and on the AO classification (κ = 0.18 compared with 0.17, p = 0.018). A subgroup analysis of the AO classification results revealed that shoulder and elbow surgeons, orthopaedic trauma surgeons, and surgeons in the United States had slightly greater reliability on 2-D CT, whereas surgeons in practice for ten years or less and surgeons from other subspecialties had slightly greater reliability on 3-D CT. CONCLUSIONS: Proximal humeral fracture classifications may be helpful conceptually, but they have poor interobserver reliability even when 3-D rather than 2-D CT is utilized. This may contribute to the similarly poor interobserver reliability that was observed for selection of the treatment for proximal humeral fractures. The lack of a reliable classification confounds efforts to compare the outcomes of treatment methods among different clinical trials and reports.

[Treatment of primary anterior shoulder dislocation; do not always treat conservatively]. / Behandeling van een eerste anterieure schouderluxatie. Niet altijd conservatief.

According to the current guidelines, primary anterior shoulder dislocations are treated conservatively after repositioning by short-term immobilisation of the shoulder. Shoulder stabilization surgery--either open or arthroscopically--reduces the risk of recurrence and improves the functional outcome over the long term. Active young adults are known to have up to a 90% increased risk of recurrent dislocation after the conservative treatment of a primary shoulder dislocation. Active young men particularly benefit from shoulder stabilization surgery. When comparing operative techniques, there is no difference between an open procedure and an arthroscopic procedure in terms of recurrence. The choice between open treatment and arthroscopic treatment depends on the preference of the patient and the experience of the surgeon.

Acute appendagitis of the ligamentum teres hepatis: clinical, ultrasound, and computed tomographic findings.

PURPOSE: To describe the clinical, ultrasound (US), and CT findings in three patients with acute appendagitis of the ligamentum teres hepatis. METHODS: A retrospective search of cases over a 4-year period was performed and yielded three patients with acute appendagitis of the ligamentum teres hepatis. The diagnosis was confirmed by US, CT, and clinical follow-up in all three cases. We retrospectively noted the laboratory data, clinical findings, and presumptive clinical diagnosis and describe the US and CT findings. RESULTS: All three patients presented with severe, circumscribed epigastric pain without other symptoms. The complex reactive protein was not elevated or only mildly elevated. At the spot of maximum pain, US and CT showed all signs of an acute appendagitis; however, the pain was not close to colon, but close to the teres ligament. Symptoms resolved within 1 to 2 weeks without therapy. CONCLUSIONS: Acute appendagitis of the teres ligament is not as rare as previously assumed. Familiarity with the US and CT features enables a reliable diagnosis and prevents unnecessary medical or operative treatment.

What are the patterns of injury and displacement seen in lateral compression pelvic fractures?

BACKGROUND: Lateral compression (LC)-type pelvic fractures encompass a wide spectrum of injuries. Current classification systems are poorly suited to help guide treatment and do not adequately describe the wide range of injuries seen in clinical practice. QUESTIONS/PURPOSES: We therefore (1) defined the spectrum of injuries that compose LC fractures with respect to both anterior and posterior ring injuries, with particular focus on the morphology of sacral fractures, and (2) identified fracture patterns associated with displacement at presentation. METHODS: We retrospectively reviewed 318 LC pelvic fractures. Displacement of the anterior pelvic ring was identified and measured on plain radiographs and posterior displacement was identified by CT. RESULTS: All 318 patients had an anterior injury and all but 13 (4%) had a posterior injury; 263 of the 318 fractures (87%) included a sacral fracture, with 162 of 318 (51%) having an anterior incomplete sacral fracture, 53 (17%) a complete simple fracture, and 48 (15%) a complete comminuted fracture. Forty-two of 318 (13%) had a crescent fracture. One hundred six of 318 (33%) were displaced at presentation. There was a higher incidence of initial displacement observed in fractures including bilateral rami fractures, a comminuted sacral fracture, or a crescent fracture. CONCLUSIONS: LC pelvic fractures represent a heterogeneous group of injuries with a wide range of associated fracture patterns. In particular, there is a wide range of fracture types represented by injuries classified as LC1 (involving any sacral fracture). Fractures with more complex sacral fractures, crescent fractures, or bilateral pubic rami fractures tend to have higher degrees of initial displacement. LEVEL OF EVIDENCE: Level IV, diagnostic study. See Instructions for Authors for a complete description of levels of evidence.

Predictors of return after cast removal in patients with a nonoperatively treated distal radius fracture.

Patients with a nonoperatively treated fracture of the distal radius are often scheduled for a follow-up appointment after cast removal to assess function and outcome. Our experience is that, once the cast is off, many patients do not return. The purpose of this study was to determine which variables significantly influence return for a scheduled visit after cast removal. Thirty-seven patients enrolled in a prospective cohort study (27 men and 10 women) with an average age of 49 years (range, 19 to 82) had a distal radius fracture immobilized in a cast. During the visit at which the cast was removed, arm-specific disability, misinterpretation of nociception, and symptoms of depression were measured using validated questionnaires. Eleven of 37 patients did not attend the final scheduled office visit and the only predictor of a return visit was older age.