Psoriatic Onycho-Pachydermo-Periostitis.

Psoriatic onycho-pachydermo-periostitis (POPP) is an unfamiliar and poorly recognised condition first described in 1989 by Fournie et al. It is a variant of psoriatic arthritis comprising the triad of onycholysis, soft tissue thickening and radiographically apparent periostitis. Whilst typically affecting the great toe, any of the digits of the hands and feet may be affected. A 'drumstick' appearance to the digits of the foot is the most common clinical presentation and can be extremely painful. Nail changes are another hallmark of POPP and can be mistakenly diagnosed as fungal infection leading to lengthy periods of incorrect treatment. In this article, we will outline the clinical presentation, imaging features, pathogenesis and treatment options for POPP. Currently, the existence of POPP is not widely known. Awareness of this unusual condition will allow early appropriate treatment and can aid in the diagnosis of indeterminate seronegative disease.

The Influence of Cervical Spine Angulation on Symptoms Associated With Wearing a Rigid Neck Collar.

INTRODUCTION: Rigid cervical spine collars can be used to maintain the position of the cervical spine following injury or surgery. However, they have been associated with difficulty swallowing, pressure sores and pain, particularly in older patients. We aimed to investigate the relationship between cervical spine angulation, a rigid neck collar and neck pain in healthy young and older adults. METHODS: Twenty healthy young adults aged 25 ± 3 years and 17 healthy older adults aged 80 ± 8 years were tested. Magnetic resonance imaging scans of their cervical spines were taken before and after the rigid neck collar was worn for 1 hour. Measurement of vertebral angulation involved digitization of the scans and joint angle calculations using image processing software. Pain was quantified before and after the collar was worn, using a visual analogue scale. RESULTS: Pain scores increased in the young group after the collar was worn (p = 0.001). The older group showed no difference in pain score after the collar was worn. Statistical tests showed no significant correlations between the change in cervical angles and the change in pain scores after the collar was worn. DISCUSSION: The aging process may contribute to the changing distribution of subcutaneous tissue and increase risk of symptoms associated with wearing a collar. Oesophageal compression is not a result of collar use. CONCLUSION: There is no correlation between cervical spine vertebrae angulation and symptoms associated with wearing a neck collar. Generally, older individuals have greater cervical lordosis angles, and more straight and lordotic neck shapes. Older individuals may be more prone to skin-interface pressures from the neck collar than younger individuals.

Missed posterior shoulder fracture dislocations: a new protocol from a London major trauma centre.

BACKGROUND: A high incidence of missed posterior shoulder dislocations is widely recognised in the literature. Concern was raised by the upper limb multidisciplinary team at a London major trauma centre that these missed injuries were causing serious consequences due to the need for surgical intervention and poor functional outcome. OBJECTIVE: To identify factors contributing to missed diagnosis and propose solutions. METHODS: A local quality improvement report was performed investigating time from admission to diagnosis of simple posterior dislocations and fracture dislocations over a 5-year period. Factors contributing to a delayed diagnosis were analysed. RESULTS: The findings supported current evidence: a posterior shoulder dislocation was more often missed if there was concurrent fracture of the proximal humerus. Anteroposterior and scapular Y view radiographs were not always diagnostic for dislocation. Axial views were more reliable in assessment of the congruency of the joint and were associated with early diagnosis and appropriate treatment of the injury. DISCUSSION: As a result of these findings a new protocol was produced by the orthopaedic and radiology departments and distributed to our emergency department practitioners and radiography team. The protocol included routine axial or modified trauma axial view radiographs for all patients attending the emergency department with a shoulder injury, low clinical suspicion for dislocation and a low threshold for CT scan. Reaudit and ongoing data collection have shown significant increase in axial view radiographs and improved diagnosis.

Anthropometric Scaling of Anatomical Datasets for Subject-Specific Musculoskeletal Modelling of the Shoulder.

Linear scaling of generic shoulder models leads to substantial errors in model predictions. Customisation of shoulder modelling through magnetic resonance imaging (MRI) improves modelling outcomes, but model development is time and technology intensive. This study aims to validate 10 MRI-based shoulder models, identify the best combinations of anthropometric parameters for model scaling, and quantify the improvement in model predictions of glenohumeral loading through anthropometric scaling from this anatomical atlas. The shoulder anatomy was modelled using a validated musculoskeletal model (UKNSM). Ten subject-specific models were developed through manual digitisation of model parameters from high-resolution MRI. Kinematic data of 16 functional daily activities were collected using a 10-camera optical motion capture system. Subject-specific model predictions were validated with measured muscle activations. The MRI-based shoulder models show good agreement with measured muscle activations. A tenfold cross-validation using the validated personalised shoulder models demonstrates that linear scaling of anthropometric datasets with the most similar ratio of body height to shoulder width and from the same gender (p < 0.04) yields best modelling outcomes in glenohumeral loading. The improvement in model reliability is significant (p < 0.02) when compared to the linearly scaled-generic UKNSM. This study may facilitate the clinical application of musculoskeletal shoulder modelling to aid surgical decision-making.

Magnetic resonance imaging appearances of the capsulo-osseous layer of the iliotibial band and femoral attachments of the iliotibial band in the normal and pivot-shift ACL injured knee.

BACKGROUND: Biomechanical evidence suggests that the anterolateral structures of the knee may be important restraints against anterolateral rotatory instability (ALRI) in the setting of anterior cruciate ligament (ACL) injury. OBJECTIVE: To describe the anatomy and presence of injury of the capsule-osseous layer of the iliotibial band (CITB), the iliotibial band, and its deep distal femoral attachments in patients with a 'normal' knee (no pivot-shift bone marrow edema (BME) pattern) and patients with a pivot-shift BME pattern indicative of a pivot-shift injury associated with ACL tears. METHODS: Group 1: 20 consecutive patients with no MRI evidence of pivot-shift injury and group 2: 20 consecutive patients with a pivot-shift BME pattern on MRI were identified. Retrospective consensus analysis of the anatomy and appearances of the CITB and the 'proximal' and 'epicondylar' distal femoral attachments of the ITB was performed for each MRI by two experienced musculoskeletal radiologists. RESULTS: The positive predictive value (PPV) of CITB injury for pivot-shift ACL injury was 74%, negative predicted Value (NPV) was 80%. The PPV for injury of the 'proximal' ITB femoral attachment with pivot-shift ACL injury was 93%, NPV was 84%. The PPV for 'epicondylar' iliotibial femoral attachment injury was 62%, NPV was 45%. CONCLUSIONS: Injury of the CITB and 'proximal' deep femoral attachments of the ITB are good markers for ACL injury even in the absence of a Segond fracture and should be evaluated on all MRIs as they may prove important in the further management of ALRI.

Use of Fat-Suppressed T2-Weighted MRI Images to Reduce the Magic Angle Effect in Peroneal Tendons.

INTRODUCTION: Peroneal tendon disorders pose a diagnostic conundrum to the clinician. Magnetic resonance imaging (MRI) is widely used to assess tendon pathology. A recognized artifact of MRI, the magic angle effect (MAE), can lead to spurious results and inappropriate management. The aim of this study is to assess whether T2 fat-suppressed sequences (T2FSs) reduce the frequency of MAE compared with proton density fat-suppressed (PDFS) images. METHODS: MRI scans of 18 patients were prospectively assessed for MAE. The peroneal tendons were assessed at 5 defined levels on PDFS and T2FS images. The frequency of MAE in the peroneal tendons were compared between the 2 scan sequences. RESULTS: In the peroneus brevis tendon, 17/72 levels, on PDFS scans, showed MAE compared with 2/72 levels on the T2FS scans, demonstrating a reduction in the MAE by 85% (P = .0003). In the peroneus longus tendon 14/72 levels, on PDFS scans, demonstrated MAE compared with 4/72 on T2FSs, demonstrating a reduction of 71% (P = .02). CONCLUSION: The inclusion of T2-weighted sequences is useful in MRI scanning for peroneal tendons to mitigate the MAE artifact, avoid potential misdiagnosis, and guide subsequent management of peroneal tendon disorders. Levels of Evidence: Level IV: Case series.

Image-Guided Intervention of the Postoperative Foot and Ankle After Ligament and Tendon Repair.

This review article describes the potential range of image-guided interventional procedures performed following foot and ankle ligament and/or tendon repair. Diagnosis of the cause of recurrent or persistent pain/symptoms in this postoperative group is challenging and requires a coordinated clinical and radiologic assessment. This directs appropriate treatment including image-guided intervention that may be used both as a diagnostic tool and a therapeutic option. There is a paucity of high-quality studies on the role of image-guided intervention in the foot and ankle after ligament/tendon repair. Many of the procedures used in this group are extrapolated from other areas of the body or the preoperative scenario. We review the role of imaging to identify the cause of postsurgical symptoms and to direct appropriate image-guided intervention. The available injectables and their roles are discussed. Specific surgical procedures are described including lateral ligament repair, Achilles repair, posterior tibialis tendon surgery, and peroneal tendon surgery.