Aims. The purpose of this study was to develop a convolutional neural network (CNN) for fracture detection, classification, and identification of greater tuberosity displacement ≥ 1 cm, neck-shaft angle (NSA) ≤ 100°, shaft translation, and articular fracture involvement, on plain radiographs. Methods. The CNN was trained and tested on radiographs sourced from 11 hospitals in Australia and externally validated on radiographs from the Netherlands. Each radiograph was paired with corresponding CT scans to serve as the reference standard based on dual independent evaluation by trained researchers and attending orthopaedic surgeons. Presence of a fracture, classification (non- to minimally displaced; two-part, multipart, and glenohumeral dislocation), and four characteristics were determined on 2D and 3D CT scans and subsequently allocated to each series of radiographs. Fracture characteristics included greater tuberosity displacement ≥ 1 cm, NSA ≤ 100°, shaft translation (0% to < 75%, 75% to 95%, > 95%), and the extent of articular involvement (0% to < 15%, 15% to 35%, or > 35%). Results. For detection and classification, the algorithm was trained on 1,709 radiographs (n = 803), tested on 567 radiographs (n = 244), and subsequently externally validated on 535 radiographs (n = 227). For characterization, healthy shoulders and glenohumeral dislocation were excluded. The overall accuracy for fracture detection was 94% (area under the receiver operating characteristic curve (AUC) = 0.98) and for classification 78% (AUC 0.68 to 0.93). Accuracy to detect greater tuberosity fracture displacement ≥ 1 cm was 35.0% (AUC 0.57). The CNN did not recognize NSAs ≤ 100° (AUC 0.42), nor fractures with ≥ 75% shaft translation (AUC 0.51 to 0.53), or with ≥ 15% articular involvement (AUC 0.48 to 0.49). For all objectives, the model’s performance on the external dataset showed similar accuracy levels. Conclusion. CNNs proficiently rule out proximal humerus fractures on plain radiographs. Despite rigorous training methodology based on CT imaging with multi-rater consensus to serve as the reference standard, artificial intelligence-driven classification is insufficient for clinical implementation. The CNN exhibited poor diagnostic ability to detect greater tuberosity displacement ≥ 1 cm and failed to identify NSAs ≤ 100°, shaft translations, or articular fractures. Cite this article: Bone Joint J 2024;106-B(11):1348–1360

We describe the routine imaging practices of Level 1 trauma centres for patients with severe pelvic ring fractures, and the interobserver reliability of the classification systems of these fractures using plain radiographs and three-dimensional (3D) CT reconstructions. Clinical and imaging data for 187 adult patients (139 men and 48 women, mean age 43 years (15 to 101)) with a severe pelvic ring fracture managed at two Level 1 trauma centres between July 2007 and June 2010 were extracted. Three experienced orthopaedic surgeons classified the plain radiographs and 3D CT reconstruction images of 100 patients using the Tile/AO and Young–Burgess systems. Reliability was compared using kappa statistics. A total of 115 patients (62%) had plain radiographs as well as two-dimensional (2D) CT and 3D CT reconstructions, 52 patients (28%) had plain films only, 12 (6.4%) had 2D and 3D CT reconstructions images only, and eight patients (4.3%) had no available images. The plain radiograph was limited to an anteroposterior pelvic view. Patients without imaging, or only plain films, were more severely injured. A total of 72 patients (39%) were imaged with a pelvic binder in situ. Interobserver reliability for the Tile/AO (Kappa 0.10 to 0.17) and Young–Burgess (Kappa 0.09 to 0.21) was low, and insufficient for clinical and research purposes. Severe pelvic ring fractures are difficult to classify due to their complexity, the increasing use of early treatment such as with pelvic binders, and the absence of imaging altogether in important patient sub-groups, such as those who die early of their injuries. Cite this article: Bone Joint J 2013;95-B:1396–1401

We evaluated the impact of stereo-visualisation of three-dimensional volume-rendering CT datasets on the inter- and intraobserver reliability assessed by kappa values on the AO/OTA and Neer classifications in the assessment of proximal humeral fractures. Four independent observers classified 40 fractures according to the AO/OTA and Neer classifications using plain radiographs, two-dimensional CT scans and with stereo-visualised three-dimensional volume-rendering reconstructions. Both classification systems showed moderate interobserver reliability with plain radiographs and two-dimensional CT scans. Three-dimensional volume-rendered CT scans improved the interobserver reliability of both systems to good. Intraobserver reliability was moderate for both classifications when assessed by plain radiographs. Stereo visualisation of three-dimensional volume rendering improved intraobserver reliability to good for the AO/OTA method and to excellent for the Neer classification. These data support our opinion that stereo visualisation of three-dimensional volume-rendering datasets is of value when analysing and classifying complex fractures of the proximal humerus

An MR scan was performed on all patients who presented to our hospital with a clinical diagnosis of a fracture of the proximal femur, but who had no abnormality on plain radiographs. This was a prospective study of 102 consecutive patients over a ten-year period. There were 98 patients who fulfilled our inclusion criteria, of whom 75 were scanned within 48 hours of admission, with an overall mean time between admission and scanning of 2.4 days (0 to 10). A total of 81 patients (83%) had abnormalities detected on MRI; 23 (23%) required operative management. The use of MRI led to the early diagnosis and treatment of occult hip pathology. We recommend that incomplete intertrochanteric fractures are managed non-operatively with protected weight-bearing. The study illustrates the high incidence of fractures which are not apparent on plain radiographs, and shows that MRI is useful when diagnosing other pathology such as malignancy, which may not be apparent on plain films

Interobserver reliability of the AO system of classification of fractures of the distal radius was assessed using plain radiographs and CT. Five observers classified 30 Colles’-type fractures using only plain radiographs; two months later they were reclassified using CT in addition. Interobserver reliability was poor in both series when detailed classification was used. By reducing the categories to five, interobserver reliability was slightly improved, but was still poor. When only two AO types were used, the reliability was moderate using plain radiographs and good to excellent with the addition of CT. The use of CT as well as plain radiographs brings interobserver reliability to a good level in assessment of the presence or absence of articular involvement, but is otherwise of minor value in improving the interobserver reliability of the AO system of classification of fractures of the distal radius

Fractures of the distal humeral articular surface which do not involve the medial and lateral columns are often more extensive than is apparent from plain radiographs. This retrospective study describes the epidemiology of this injury using modern classification systems and compares pre-operative radiography with operative findings. The study group included 79 patients with a mean age of 47 years (13 to 91). The annual incidence was 1.5 per 100 000 population, and was highest in women over the age of 60. The majority of the fractures (59; 75%) were sustained in falls from standing height. Young males tended to sustain more high-energy injuries with more complex fracture patterns. In 24% of cases (19) there was a concomitant radial head fracture. Classification from plain radiographs often underestimates the true extent of the injury and computed tomography may be of benefit in pre-operative planning, especially in those over 60 years of age

We treated 50 patients with fractures of the waist of the scaphoid in a below-elbow plaster cast for up to 13 weeks. Displacement of the fragments was assessed independently by two observers using MRI and radiographs performed within two weeks of injury. The MRI assessments showed that only the measurement of sagittal translation of the fragments and an overall assessment of displacement had satisfactory inter- and intra-observer reproducibility and revealed that nine of the 50 fractures were displaced. Only three of the 49 fractures with adequate follow-up failed to unite, and all were displaced with more than 1 mm of translation in the sagittal plane. If the MRI assessment of displacement of the fracture was used as the measurement of choice, assessment of displacement on the initial scaphoid series of radiographs showed a sensitivity of between 33% and 47% and a positive predictive value of between 27% and 86%. Neither observer was able correctly to identify more than 33% to 47% of the displaced fractures from the plain radiographs. Although the overall assessment of displacement and gapping and translation in the coronal plane on the plain radiographs influenced the rate of union, none of these parameters identified all three fractures which failed to unite. We conclude that the assessment of displacement of scaphoid fractures on MRI can probably be used to assess the likelihood of union although the small number of nonunions limits the power of the study. In contrast, the assessment of displacement on routine radiography is inaccurate and of less value in predicting union

We have studied prospectively the effect of indomethacin on the development of heterotopic ossification (HO) after the internal fixation of acetabular fractures. After operation 107 patients randomly received either a six-week course of indomethacin or no treatment against HO. Plain radiographs of 101 patients at a mean of 7.9 months after surgery showed HO in 47.4% of the 57 patients who received indomethacin and in 56.8% of the 44 who did not. This difference was not statistically significant. Heterotopic ossification of Brooker class II or more was seen in four patients (7%) with prophylaxis and in one without (p = 0.51). Measurements of the volume of HO on 3-D CT reconstructions showed a median value of 1.5 cm. 3. in patients with indomethacin and 4.0 cm. 3. in those without (p = 0.28). When only the 57 patients in whom the operation was carried out through either a Kocher-Langenbeck or an extended iliofemoral approach were included the indomethacin group showed a median volume of 1.7 cm. 3. compared with 3.6 cm. 3. On plain radiographs Brooker class II or above was seen in 9.4% of the patients receiving indomethacin and in 4.8% of those who did not. Indomethacin was therefore not effective in preventing ectopic bone formation after surgery for acetabular fractures. There was a significant association of male gender with volume of HO using a non-parametric analysis of variance

We have examined the accuracy of reduction and the functional outcomes in elderly patients with surgically treated acetabular fractures, based on assessment of plain radiographs and CT scans. There were 45 patients with such a fracture with a mean age of 67 years (59 to 82) at the time of surgery. All patients completed SF-36 questionnaires to determine the functional outcome at a mean follow-up of 72.4 months (24 to 188). All had radiographs and a CT scan within one week of surgery. The reduction was categorised as ‘anatomical’, ‘imperfect’, or ‘poor’. Radiographs classified 26 patients (58%) as anatomical,13 (29%) as imperfect and six (13%) as poor. The maximum displacement on CT showed none as anatomical, 23 (51%) as imperfect and 22 (49%) as poor, but this was not always at the weight-bearing dome. SF-36 scores showed functional outcomes comparable with those of the general elderly population, with no correlation with the radiological reduction. Perfect anatomical reduction is not necessary to attain a good functional outcome in acetabular fractures in the elderly

Incomplete intertrochanteric fractures do not extend across to the medial femoral cortex and are stable, without rotational deformity or shortening of the lower limb. The aim of our study was to establish whether they can be successfully managed conservatively. A total of 68 patients over a five-year period presented with a suspected fracture of the femoral neck and underwent an MRI scan for further assessment. From these, we retrospectively reviewed eight patients with normal plain radiographs but with an incomplete, intertrochanteric fracture on MRI scan. Five were managed conservatively and three operatively. The mean length of hospital stay was 16 days for the conservatively-treated group and 15 days for those who underwent surgery; this was not statistically significant (p > 0.5) and all patients were mobilised on discharge. Although five patients were readmitted at a mean of 3.2 years after discharge, none had progressed to a complete fracture. We believe that patients with incomplete intertrochanteric fractures should be considered for conservative treatment

Objectives. Small animal models of fracture repair primarily investigate indirect fracture healing via external callus formation. We present the first described rat model of direct fracture healing. Methods. A rat tibial osteotomy was created and fixed with compression plating similar to that used in patients. The procedure was evaluated in 15 cadaver rats and then in vivo in ten Sprague-Dawley rats. Controls had osteotomies stabilised with a uniaxial external fixator that used the same surgical approach and relied on the same number and diameter of screw holes in bone. Results. Fracture healing occurred without evidence of external callus on plain radiographs. At six weeks after fracture fixation, the mean stress at failure in a four-point bending test was 24.65 N/mm. 2. (. sd. 6.15). Histology revealed ‘cutting-cones’ traversing the fracture site. In controls where a uniaxial external fixator was used, bone healing occurred via external callus formation. Conclusions. A simple, reproducible model of direct fracture healing in rat tibia that mimics clinical practice has been developed for use in future studies of direct fracture healing

Specific radiological features identified by Brandser and Marsh were selected for the analysis of acetabular fractures according to the classification of Letournel and Judet. The method employs a binary approach that requires the observer to allocate each radiological feature to one of two groups. The inter- and intra-observer variances were assessed. The presence of articular displacement, marginal impaction, incongruity, intra-articular fragments and osteochondral injuries to the femoral head were analysed by a similar method. These factors were termed ‘modifiers’ and are generally considered when planning operative intervention and, critically, they may influence prognosis. Six observers independently assessed 30 sets of plain radiographs and CT scans on two separate occasions, 12 weeks apart. They were asked to determine the presence or absence of specific radiological features. This simple binary approach to classification yields an inter- and intra-observer agreement which ranges from moderate to near-perfect (κ = 0.49 to 0.88 and κ = 0.57 to 0.88, respectively). A similar approach to the modifiers yields only slight to fair inter-observer agreement (κ = 0.20 to 0.34) and slight to moderate intra-observer agreement (κ = 0 to 0.55)

We have evaluated retrospectively the relationship of bony injuries seen on 106 consecutive MR scans in elderly patients of a mean age of 81.4 years (67 to 101) who were unable to bear weight after a low-energy injury. There were no visible fractures on plain radiographs of the hip but eight patients (7.5%) had fractures of the pubic ramus. In 43 patients (40.5%) MRI revealed a fracture of the femoral neck and in 26 (24.5%) there was a fracture of a pubic ramus. In 17 patients (16%) MRI showed an occult sacral fracture and all of these had a fracture of the pubic ramus. No patient with a fracture of the femoral neck had an associated fracture of the pelvic ring or vice versa. Occult fracture of the hip and of the pelvic ring appear to be mutually exclusive and if an acute fracture of the pubic ramus is diagnosed radiologically further investigations are not needed to rule out an occult fracture of the hip

Our aim was to evaluate the efficacy of a two-level reconstruction technique using subchondral miniscrews for the stabilisation of comminuted posterior-wall marginal acetabular fragments before applying lag screws and a buttress plate to the main overlying posterior fragment. Between 1995 and 2003, 29 consecutive patients with acute comminuted displaced posterior-wall fractures of the acetabulum were treated operatively using this technique. The quality of reduction measured from three standard plain radiographs was graded as anatomical in all 29 hips. The clinical outcome at a mean follow-up of 35 months (24 to 90) was considered to be excellent in five patients (17%), very good in 16 (55%), good in six (21%) and poor in two (7%). The use of the two-level reconstruction technique appears to provide stable fixation and is associated with favourable results in terms of the incidence of post-traumatic osteoarthritis and the clinical outcome. However, poor results may occur in patients over the age of 55 years

There remains uncertainty about the most effective surgical approach in the treatment of complex fractures of the acetabulum. We have reviewed the experience of a single surgeon using the extended iliofemoral approach, as described by Letournel. A review of the database of such fractures identified 106 patients operated on using this approach with a minimum follow-up of two years. All data were collected prospectively. The fractures involved both columns in 64 (60%). Operation was undertaken in less than 21 days after injury in 71 patients (67%) and in 35 (33%) the procedure was carried out later than this. The reduction of the fracture was measured on plain radiographs taken after operation and defined as anatomical (0 to 1 mm of displacement); imperfect (2 to 3 mm) or poor (> 3 mm). The functional outcome was measured by the modified Merle d’Aubigné and Postel score. The mean follow-up was for 6.3 years (2 to 17). All patients achieved union of the fractures. The reduction was graded as anatomical in 76 (72%) of the patients, imperfect in 23 (22%), and poor in six (6%). The mean Merle d’Aubigné and Postel score was 15 (5 to 18) with 68 patients (64%) showing good or excellent and 38 (36%) fair or poor results. Function correlated significantly with the accuracy of the reduction (p < 0.009). Significant heterotopic ossification developed in 32 patients (30%) and was associated with a worse mean Merle d’Aubigné and Postel score of 13.7. The extended iliofemoral approach can be performed safely in selected complex acetabular fractures with an acceptable clinical outcome and rate of complications. Effective prophylaxis against heterotopic ossification should be strongly considered

Plain radiographs show only two dimensions of a three-dimensional object. On anteroposterior and lateral radiographs an implant may appear to be safely within the head of the femur although surface penetration has occurred. We have attempted to identify this complication in the treatment of fractures of the femoral neck and have analysed the position of a screw or pin in the femoral head and neck on the basis of orthogonal frontal and lateral radiographs. A retrospective analysis of 60 cases of osteosynthesis of fractures of the femoral neck confirmed the risk of non-recognition of articular penetration or breaking of the cortex of the neck during surgery. Unrecognised screw penetration of the hip was observed in 8% and of the posterior part of the neck in 10%. The risk differs according to the type of fracture: it is greater in the coxa valga produced by Garden-I fractures of the femoral neck

Our study was designed to compare the effect of indometacin with that of a placebo in reducing the incidence of heterotopic ossification in a prospective, randomised trial. A total of 121 patients with displaced fractures of the acetabulum treated by operation through a Kocher-Langenbeck approach was randomised to receive either indometacin (75 mg) sustained release, or a placebo once daily for six weeks. The extent of heterotopic ossification was evaluated on plain radiographs three months after operation. Significant ossification of Brooker grade III to IV occurred in nine of 59 patients (15.2%) in the indometacin group and 12 of 62 (19.4%) receiving the placebo. We were unable to demonstrate a statistically significant reduction in the incidence of severe heterotopic ossification with the use of indometacin when compared with a placebo (p = 0.722). Based on these results we cannot recommend the routine use of indometacin for prophylaxis against heterotopic ossification after isolated fractures of the acetabulum

We carried out a retrospective review of 47 intra-articular fractures of the calcaneum treated by open reduction and internal fixation in 45 patients by a single surgeon between 1993 and 2001. The fractures were evaluated before operation by plain radiographs and a CT scan using Sanders’ classification. Osteosynthesis involved a lateral approach and the use of the AO calcaneal plate. The mean follow-up was for ten years (7 to 15). Clinical assessment included the American Orthopaedic Foot and Ankle Society Score (AOFAS), the Creighton-Nebraska Score, the Kerr, Prothero, Atkins Score and the SF-36 Health Questionnaire. The radiological evaluation consisted of lateral and axial views of the os calcis. Arthritic changes in the subtalar joint were assessed with an internal oblique view and were graded using the Morrey and Wiedeman scale. There were 18 excellent (38.3%), 17 good (36.2%), three fair (6.3%) and nine poor (19.2%) results. Five patients had a superficial wound infection and five others eventually had a subtalar arthrodesis because of continuing pain. Restoration of Böhler’s angle was associated with a better outcome. The degree of arthritic change in the subtalar joint did not correlate with the outcome scores or Sanders’ classification. Prompt osteosynthesis should be considered for intra-articular fractures of the calcaneum in order to restore the shape of the hindfoot and Böhler’s angle

Distal tibial physeal fractures are the second most common growth plate injury and the most common cause of growth arrest and deformity. This study assesses the accuracy of pre-operative planning for placement of the screws in these fractures using either standard radiographs or CT scans. We studied 62 consecutive physeal fractures over a period of four years. An outline of a single cut of the CT scan was used for each patient. An ideal position for the screw was determined as being perpendicular to and at the midpoint of the fracture. The difference in entry point and direction of the screw between the ideal and the observers’ assessments were compared using the paired Student’s t-test. There was a statistically significant improvement (p < 0.0001) in the accuracy of the point of insertion and the direction of the screw on the pre-operative plan when CT scans were used rather than plain radiographs. We would, therefore, recommend that CT scans are routinely used in the pre-operative assessment and treatment of distal tibial physeal fractures

Aims

Occult (clinical) injuries represent 15% of all scaphoid fractures, posing significant challenges to the clinician. MRI has been suggested as the gold standard for diagnosis, but remains expensive, time-consuming, and is in high demand. Conventional management with immobilization and serial radiography typically results in multiple follow-up attendances to clinic, radiation exposure, and delays return to work. Suboptimal management can result in significant disability and, frequently, litigation.