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.

Diagnostic accuracy of an artificial intelligence algorithm versus radiologists for fracture detection on cervical spine CT.

OBJECTIVES: To compare diagnostic accuracy of a deep learning artificial intelligence (AI) for cervical spine (C-spine) fracture detection on CT to attending radiologists and assess which undetected fractures were injuries in need of stabilising therapy (IST). METHODS: This single-centre, retrospective diagnostic accuracy study included consecutive patients (age ≥18 years; 2007-2014) screened for C-spine fractures with CT. To validate ground truth, one radiologist and three neurosurgeons independently examined scans positive for fracture. Negative scans were followed up until 2022 through patient files and two radiologists reviewed negative scans that were flagged positive by AI. The neurosurgeons determined which fractures were ISTs. Diagnostic accuracy of AI and attending radiologists (index tests) were compared using McNemar. RESULTS: Of the 2368 scans (median age, 48, interquartile range 30-65; 1441 men) analysed, 221 (9.3%) scans contained C-spine fractures with 133 IST. AI detected 158/221 scans with fractures (sensitivity 71.5%, 95% CI 65.5-77.4%) and 2118/2147 scans without fractures (specificity 98.6%, 95% CI 98.2-99.1). In comparison, attending radiologists detected 195/221 scans with fractures (sensitivity 88.2%, 95% CI 84.0-92.5%, p < 0.001) and 2130/2147 scans without fracture (specificity 99.2%, 95% CI 98.8-99.6, p = 0.07). Of the fractures undetected by AI 30/63 were ISTs versus 4/26 for radiologists. AI detected 22/26 fractures undetected by the radiologists, including 3/4 undetected ISTs. CONCLUSION: Compared to attending radiologists, the artificial intelligence has a lower sensitivity and a higher miss rate of fractures in need of stabilising therapy; however, it detected most fractures undetected by the radiologists, including fractures in need of stabilising therapy. Clinical relevance statement The artificial intelligence algorithm missed more cervical spine fractures on CT than attending radiologists, but detected 84.6% of fractures undetected by radiologists, including fractures in need of stabilising therapy. KEY POINTS: The impact of artificial intelligence for cervical spine fracture detection on CT on fracture management is unknown. The algorithm detected less fractures than attending radiologists, but detected most fractures undetected by the radiologists including almost all in need of stabilising therapy. The artificial intelligence algorithm shows potential as a concurrent reader.

Anterior locking plate fixation versus cast immobilization for acceptably reduced extra- articular distal radial fractures: long-term follow-up of a randomized controlled trial.

This study reports the long-term results of a randomized controlled trial comparing anterior locking plate fixation with cast immobilization for extra-articular distal radial fractures. After 5.3 years of follow-up, no clinically relevant functional differences were found.

Does Revision Carpal Tunnel Release Result in Long-Term Outcomes Equivalent to Single Carpal Tunnel Release? A Matched Case-Control Analysis.

BACKGROUND: The aims of this study were to evaluate long-term patient-reported outcomes after revision carpal tunnel release (CTR); compare these outcomes with those of patients who had a single CTR and a comparable age, sex, race, type of initial surgery, and follow-up time; and assess which factors are associated with worse patient-reported outcomes after revision CTR. METHODS: The authors retrospectively identified 7351 patients who had a single CTR and 113 patients who had a revision CTR for carpal tunnel syndrome between January of 2002 and December of 2015 at five academic urban hospitals. Of these 113 revision CTR cases, 37 patients completed a follow-up questionnaire including the Boston Carpal Tunnel Questionnaire (BCTQ), the Numerical Rating Scale for Pain Intensity, and satisfaction score. Those who completed the follow-up questionnaire were randomly matched to five controls (patients who had a single CTR) based on age, sex, race, type of initial surgery, and follow-up time. Of these 185 matched controls, 65 completed the follow-up questionnaire. RESULTS: A linear mixed effects model using matched sets as a random effect showed that patients who had a revision CTR had a higher total BCTQ score, Numerical Rating Scale for Pain Intensity score, and a lower satisfaction score at time of follow-up than patients who had a single CTR. Multivariable linear regression showed that thenar muscle atrophy before the revision surgery was independently associated with more pain after revision surgery. CONCLUSION: Patients improve after revision CTR, but generally have more pain, have a higher BCTQ score, and are less satisfied at long-term follow-up compared with patients who had a single CTR.

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.

[Lacertus syndrome, an unknown and underestimated diagnosis]. / Het lacertussyndroom.

BACKGROUND: Carpal tunnel syndrome (CTS) is well-known. Less familiar are proximal median nerve entrapments such as the lacertus syndrome. Lacertus syndrome symptoms are very similar to CTS, but often unknowledged. CASE DESCRIPTION: A 37 year old male with persistent tingling of the median nerve area after 3 CTS releases on both wrists. The diagnosis CTS was confirmed with EMG and ultrasound. In our outpatient clinic we saw weakness of the tip pinch (FPL, FDP2). Loss of sensibility in the proximal thenar and digits 1-3 and a positive scratch collapse test. We suspected the patient has lacertus syndrome and performed a lacertus release. All symptoms dissolved afterwards. CONCLUSION: If symptoms do not resolve after CTS-release proximal median nerve compressions should be considered. Tip pinch strength and sensibility of the thenar can differentiate between the various locations of median nerve entrapment. Redo CTS-release lead to unnecessary treatment and costs, because of the wrong diagnosis.

Patient outcomes before and after implementation of a selective pre-hospital spinal immobilization protocol: A comparative cohort pilot study in a level 2 trauma center.

BACKGROUND: A new selective preventive spinal immobilization (PSI) protocol was introduced in the Netherlands. This may have led to an increase in non-immobilized spinal fractures (NISFs) and consequently adverse patient outcomes. AIM: A pilot study was conducted to describe the adverse patient outcomes in NISF of the PSI protocol change and assess the feasibility of a larger effect study. METHODS: Retrospective comparative cohort pilot study including records of trauma patients with a presumed spinal injury who were presented at the emergency department of a level 2 trauma center by the emergency medical service (EMS). The pre-period 2013-2014 (strict PSI protocol), was compared to the post-period 2017-2018 (selective PSI protocol). Primary outcomes were the percentage of records with a NISF who had an adverse patient outcome such as neurological injuries and mortality before and after the protocol change. Secondary outcomes were the sample size calculation for a larger study and the feasibility of data collection. RESULTS: 1,147 records were included; 442 pre-period, and 705 post-period. The NISF-prevalence was 10% (95% CI 7-16, n = 19) and 8% (95% CI 6-11, n = 33), respectively. In both periods, no neurological injuries or mortality due to NISF were found, by which calculating a sample size is impossible. Data collection showed to be feasible. CONCLUSIONS: No neurological injuries or mortality due to NISF were found in a strict and a selective PSI protocol. Therefore, a larger study is discouraged. Future studies should focus on which patients really profit from PSI and which patients do not.

Four weeks versus six weeks of immobilization in a cast following closed reduction for displaced distal radial fractures in adult patients: a multicentre randomized controlled trial.

Aims: There is no level I evidence dealing with the optimal period of immobilization for patients with a displaced distal radial fracture following closed reduction. A shorter period might lead to a better functional outcome due to less stiffness and pain. The aim of this study was to investigate whether this period could be safely reduced from six to four weeks. Methods: This multicentre randomized controlled trial (RCT) included adult patients with a displaced distal radial fracture, who were randomized to be treated with immobilization in a cast for four or six weeks following closed reduction. The primary outcome measure was the Patient-Rated Wrist Evaluation (PRWE) score after follow-up at one year. Secondary outcomes were the abbreviated version of the Disability of Arm, Shoulder and Hand (QuickDASH) score after one year, the functional outcome at six weeks, 12 weeks, and six months, range of motion (ROM), the level of pain after removal of the cast, and complications. Results: A total of 100 patients (15 male, 85 female) were randomized, with 49 being treated with four weeks of immobilization in a cast. A total of 93 completed follow-up. The mean PRWE score after one year was 6.9 (SD 8.3) in the four-week group compared with 11.6 (SD 14.3) in the six-week group. However, this difference of -4.7 (95% confidence interval -9.29 to 0.14) was not clinically relevant as the minimal clinically important difference of 11.5 was not reached. There was no significant difference in the ROM, radiological outcome, level of pain, or complications. Conclusion: In adult patients with a displaced and adequately reduced distal radial fracture, immobilization in a cast for four weeks is safe, and the results are similar to those after a period of immobilization of six weeks.

Concomitant ligament injuries can be left untreated during surgery of distal radial fractures.

Instability of the distal radioulnar joint and scapholunate dissociation may cause pain, functional impairment and subsequent arthrosis. There is no consensus about whether these injuries should be treated acutely in patients undergoing surgery for distal radial fractures. We conducted a prospective cohort study to determine whether concomitant distal radioulnar joint instability or scapholunate dissociation negatively influence patient-related outcomes in these patients. The primary outcome was the patient-reported wrist/hand evaluation at 6 and 12 months after surgery. Out of 62 patients, 58% and 27% had intraoperative distal radioulnar joint instability and scapholunate dissociation, respectively. No significant differences were found in patient-reported scores at follow-up between patients with stable and unstable distal radioulnar joints, nor between patients with and without scapholunate dissociation. Sixty-three per cent of patients with an unstable distal radioulnar joint during surgery were stable on retesting after 6 months. Our study suggests that a wait-and-see policy in these patients therefore seems reasonable.Level of evidence: III.

The Current Role of Arthroscopy in Traumatic Wrist Injuries: An Expert Survey.

Background Wrist arthroscopy has become increasingly popular for diagnosing and treating traumatic wrist injuries. How wrist arthroscopy has influenced the daily practice of wrist surgeons remains unclear. The objective of this study was to evaluate the role of wrist arthroscopy for the diagnosis and treatment of traumatic wrist injuries among members of the International Wrist Arthroscopy Society (IWAS). Methods An online survey was conducted among IWAS members between August and November 2021 with questions regarding the diagnostic and therapeutic importance of wrist arthroscopy. Questions focused on traumatic injuries of the triangular fibrocartilage complex (TFCC) and scapholunate ligament (SLL). Multiple-choice questions were presented in the form of a Likert scale. The primary outcome was respondent agreement, defined as 80% answering similarly. Results The survey was completed by 211 respondents (39% response rate). The majority (81%) were certified or fellowship-trained wrist surgeons. Most respondents (74%) had performed over 100 wrist arthroscopies. Agreement was reached on 4 of the 22 questions. It was agreed that the outcomes of wrist arthroscopy strongly depend on surgeons' experience, that there is sufficient evidence for the diagnostic purposes of wrist arthroscopy, and that wrist arthroscopy is better than magnetic resonance imaging (MRI) for diagnosing TFCC and SLL injuries. No agreement was reached on the preferred treatment of any type of TFCC or SLL injury. Conclusion There is agreement that wrist arthroscopy is superior to MRI for diagnosing traumatic TFCC and SLL injuries, yet experts remain divided on the optimal management. Guidelines need to be developed for the standardization of indications and procedures. Level of Evidence This is a Level III study.

Development and validation of the paediatric elbow trauma (PET) rules as a decision rule for radiography in traumatic elbow injuries: a study protocol.

BACKGROUND: Traumatic elbow injuries in children occur frequently and are among the most common traumatic injuries seen in the emergency department (ED) and in general practice. The use of a validated decision rule to enhance selective radiography in paediatric patients with possible elbow fractures may reduce unnecessary exposure to radiation in children. METHOD AND ANALYSIS: This study is designed as a multicentre prospective cohort study. An expert panel of orthopaedic elbow surgeons, paediatric orthopaedic surgeons and trauma surgeons will initially determine clinical parameters that provide a possible predictive value for elbow fractures. Four hundred children between the ages of 2 and 17 years visiting the ED with pain following elbow trauma will then be included. The clinical parameters will be collected via patient history and physical examination. Elbow radiographs will be obtained in all patients to identify fractures. The data will be processed in a multivariable logistic regression analysis to determine which clinical parameters predict the presence of an elbow fracture. Only the clinical parameters that predict a fracture will be used to formulate the new decision rule: the paediatric elbow trauma (PET) rules. Internal validation of the prediction model will take place after inclusion is complete and by means of a bootstrap analysis on the acquired data. A calculation will be made to determine how many radiographs can potentially be reduced by applying the PET rules and a cost analysis will be performed. ETHICS AND DISSEMINATION: The study will be conducted according to the principles of the Declaration of Helsinki and in accordance with the Medical Research Involving Human Subjects Act. The Medical Research Ethics Committees United stated on 16 May 2022 that The Medical Research Involving Human Act (WMO) does not apply to this study and an official approval by the committee is not required, reference number; project W22.086.

Outcome of functional treatment with a Lucerne Cast in patients with hand fractures: a retrospective case series.

PURPOSE: The purpose of this study was to determine the clinical outcome of patients treated with a functional Lucerne Cast (LuCa) for different types of hand fractures. Static casting has traditionally been the preferred treatment for hand fractures. However, functional casting may lead to good functional outcomes, less stiffness, and earlier return to work. METHODS: A retrospective case series of all consecutive patients with a metacarpal or proximal phalangeal fracture treated with a LuCa between 2018 and 2019 was conducted. A total of 90 patients were included. Clinical data were collected directly from the patient's medical records. Functional outcome was assessed with the Michigan Hand Outcomes Questionnaire (MHQ). RESULTS: The median MHQ score was 95 (IQR 83-100) with a median follow-up of 23 months. Complications occurred in 7 of 90 patients (8%). Functional impairment occurred in two (2%) patients. Functional impairment was defined as stiffness, persisting rotational deformity, a boutonnière or swanneck deformity. Persisting pain or CRPS occurred in six (7%) patients. CONCLUSION: The LuCa shows to be effective in the functional treatment of both metacarpal and proximal phalangeal fractures with excellent patient-reported outcomes but at a relatively high rate of persisting pain.

Masquelet Procedure for the Treatment of Intra-articular Defects of the Wrist.

Background The purpose of this case series is to show our experiences with the Masquelet procedure in a variety of infected defects of the wrist. Case Description All consecutive patients that were treated between 2015 and 2021 were included in this case series. Five patients were included with an infected defect of the wrist, involving the radiocarpal and/or the distal radioulnar joints (DRUJ). All patients underwent thorough debridement of the defect and the created void was filled with a gentamicin/vancomycin cement spacer. Cultures were taken and appropriate antibiotic therapy was initiated. Two patients had a renewal of the cement spacer before definitive surgery. Finally, two patients received a DRUJ prosthesis, two patients had autologous bone grafting and wrist arthrodesis and one patient kept the cement spacer as distal ulna prosthesis due to minor complaints. Literature Review Current literature provides examples of the Masquelet procedure in traumatic defects or non-unions of the long bones. These cases are almost always about metaphyseal or diaphyseal defects but rarely include intra-articular joint defects therefore no comparisons could be made between the cases we reported with any existing literature. Clinical Relevance The Masquelet procedure showed to be effective in eradicating infected defects of the wrist involving the radiocarpal joint and/or DRUJ. All patients had an aseptic environment before performing definitive surgery. This technique showed to be save and no reinfections occurred.

Bone visualization of the cervical spine with deep learning-based synthetic CT compared to conventional CT: A single-center noninferiority study on image quality.

PURPOSE: To investigate whether the image quality of a specific deep learning-based synthetic CT (sCT) of the cervical spine is noninferior to conventional CT. METHOD: Paired MRI and CT data were collected from 25 consecutive participants (≥ 50 years) with cervical radiculopathy. The MRI exam included a T1-weighted multiple gradient echo sequence for sCT reconstruction. For qualitative image assessment, four structures at two vertebral levels were evaluated on sCT and compared with CT by three assessors using a four-point scale (range 1-4). The noninferiority margin was set at 0.5 point on this scale. Additionally, acceptable image quality was defined as a score of 3-4 in ≥ 80% of the scans. Quantitative assessment included geometrical analysis and voxelwise comparisons. RESULTS: Qualitative image assessment showed that sCT was noninferior to CT for overall bone image quality, artifacts, imaging of intervertebral joints and neural foramina at levels C3-C4 and C6-C7, and cortical delineation at C6-C7. Noninferiority was weak to absent for cortical delineation at level C3-C4 and trabecular bone at both levels. Acceptable image quality was achieved for all structures in sCT and CT, except for trabecular bone in sCT and level C6-C7 in CT. Geometrical analysis of the sCT showed good to excellent agreement with CT. Voxelwise comparisons showed a mean absolute error of 80.05 (±6.12) HU, dice similarity coefficient (cortical bone) of 0.84 (±0.04) and structural similarity index of 0.86 (±0.02). CONCLUSIONS: This deep learning-based sCT was noninferior to conventional CT for the general visualization of bony structures of the cervical spine, artifacts, and most detailed structure assessments.

[Arthroscopy of the wrist]. / Artroscopie van de pols.

Arthroscopy of the wrist has gained popularity among hand and wrist surgeons for diagnosing and treating wrist pathologies. In general, it is a minimally-invasive procedure which can be performed in day care surgery. It has a higher diagnostic accuracy compared to conventional imaging modalities such as CT or MRI. Simultaneous therapeutic intervention can be performed such as ligament repair, fracture reduction, ganglion cyst removal or synovectomy of the wrist. Recent studies have shown better functional outcomes and fewer complications compared to open surgical interventions. Prospective studies are still needed to confirm effectiveness and safety of wrist arthroscopy for several indications. Nonetheless, wrist arthroscopy has shown to be an important asset in the repertoire of the hand and wrist surgeon.

Assessment of cervical spine CT scans by emergency physicians: A comparative diagnostic accuracy study in a non-clinical setting.

OBJECTIVES: To determine and compare the diagnostic accuracy of assessing injuries on cervical spine computed tomography (CT) scans by trained emergency physicians and radiologists, both in a non-clinical setting. METHODS: In this comparative diagnostic accuracy study, 411 cervical spine CT scans, of which 120 contained injuries (fractures and/or dislocations), were divided into 8 subsets. Eight emergency physicians received focused training and assessed 1 subset each before and after training. Four radiologists assessed 2 subsets each. Diagnostic accuracy between both groups was compared. The reference standard used was a multiverified data set, assessed by radiologists, neurosurgeons, and emergency physicians. The neurosurgeons also classified whether an "injury in need of stabilizing therapy" (IST) was present. RESULTS: Posttraining, the emergency physicians demonstrated increased sensitivity and specificity for identifying cervical spine injuries compared to pretraining: sensitivity 88% (95% confidence interval [CI] 80% to 93%) versus 80% (95% CI 72% to 87%) and specificity 89% (95% CI 85% to 93%) versus 86% (95% CI 81% to 89%). When comparing the trained emergency physicians to the group of radiologists, no difference in sensitivity was found, 88% (95% CI 80% to 83%); however, the radiologists showed a significantly higher specificity (P < 0.01): 99% (95% CI 96% to 100%). In the 12% (15 scans) with missed injuries, emergency physicians missed more ISTs than radiologists, 6 versus 4 scans; however, this difference was not significant (P = 0.45). CONCLUSION: After focused training and in a non-clinical setting, no significant difference was found between emergency physicians and radiologists in ruling out cervical spine injuries; however, the radiologists achieved a significantly higher specificity.

Comparison of extra-articular radiographic parameters of distal radius fractures on plain radiographs and CT scans.

The aim of this study was to compare extra-articular radiographic parameters of distal radial fractures measured on plain radiographs and CT scans. Two researchers independently measured four extra-articular radiographic parameters (dorsal tilt, carpal alignment, radial inclination and ulnar variance) on both radiographs and CT scans in 85 patients. Inter-observer reliability for both techniques was assessed, along with the agreement between CT scans and radiographs using the intraclass correlation coefficient and Bland-Altman plots. The results showed that dorsal tilt, carpal alignment, radial inclination and ulnar variance can be measured reliably on both radiographs and CT scans. At a patient level, carpal alignment, radial inclination and ulnar variance CT scan measurements are an acceptable alternative to plain radiograph measurements in the vast majority of patients. In contrast, dorsal tilt CT scan measurements are not comparable with radiographs in 40% of the cases. Therefore, caution should be taken in measuring dorsal tilt on CT scans.

Temporary spanning plate wrist fixation of complex distal radius fractures: a systematic review of 353 patients.

PURPOSE: Temporary spanning plate fixation of the wrist has been described as an alternative treatment method for complex distal radius fractures (DRfs). This systematic review aims to gain insight on clinical and radiological outcomes of this technique currently published in literature. METHODS: A comprehensive literature search of Pubmed, Embase, CENTRAL and CINAHL databases was conducted on November 5th 2020. All studies reporting on complications, functional, patient-rated and radiological outcomes of temporary spanning plate wrist fixation of DRFs in adult patients were included. RESULTS: Two prospective and eight retrospective cohort studies were included encompassing 353 patients with of 357 DRFs. The overall mean age was 53 years (range 19-95 years). Overall mean follow-up ranged from 6 months to 8.8 years. The union rate was 99.4%. Plate removal was performed on average 4.5 months after initial operation (range 1.1-28.9 months). The most frequently reported complication was implant failure with an incidence of 3.1%. Mean flexion/extension, pronation/supination and radial/ulnar inclination arc averaged 96.6°, 151.5° and 36.5°, respectively. Grip strength averaged 79.7% of the contralateral side. Mean DASH and PRWE scores were 22.9 and 16 points, respectively. Radiological indices were all within the acceptable limits. CONCLUSIONS: Temporary spanning plate wrist fixation is a safe method for the treatment of complex DRFs. This technique can exploit the advantages of temporary wrist immobilization without the disadvantages of external fixation. With these aspects in mind, the spanning plate can serve as a valuable tool in the treatment of complex intra-articular DRFs.