CT methods for measuring glenoid bone loss are inaccurate, and not reproducible or interchangeable.

Aims: Glenoid bone loss is a significant problem in the management of shoulder instability. The threshold at which the bone loss is considered "critical" requiring bony reconstruction has steadily dropped and is now approximately 15%. This necessitates accurate measurement in order that the correct operation is performed. CT scanning is the most commonly used modality and there are a number of techniques described to measure the bone loss however few have been validated. The aim of this study was to assess the accuracy of the most commonly used techniques for measuring glenoid bone loss on CT. Methods: Anatomically accurate models with known glenoid diameter and degree of bone loss were used to determine the mathematical and statistical accuracy of six of the most commonly described techniques (relative diameter, linear ipsilateral circle of best fit (COBF), linear contralateral COBF, Pico, Sugaya, and circle line methods). The models were prepared at 13.8%, 17.6%, and 22.9% bone loss. Sequential CT scans were taken and randomized. Blinded reviewers made repeated measurements using the different techniques with a threshold for theoretical bone grafting set at 15%. Results: At 13.8%, only the Pico technique measured under the threshold. At 17.6% and 22.9% bone loss all techniques measured above the threshold. The Pico technique was 97.1% accurate, but had a high false-negative rate and poor sensitivity underestimating the need for grafting. The Sugaya technique had 100% specificity but 25% of the measurements were incorrectly above the threshold. A contralateral COBF underestimates the area by 16% and the diameter by 5 to 7%. Conclusion: No one method stands out as being truly accurate and clinicians need to be aware of the limitations of their chosen technique. They are not interchangeable, and caution must be used when reading the literature as comparisons are not reliable.

Association between Patellofemoral Anatomy and Chondral Lesions of the Knee in Patellofemoral Instability.

Chondral injury is a serious consequence of patellar dislocation and patellofemoral instability (PFI). There is limited data on the relationship between radiological features such as sulcus angle and patellar height to the presence, location, and severity of chondral lesions. The purpose of this study was to determine the association of anatomical variants in patellofemoral instability with injuries sustained due to patellar dislocation. A cohort of 101 patients who had four or more episodes of dislocation or instability undergoing isolated arthroscopy or arthroscopies at the time of corrective realignment surgery were identified. The prevalence of chondral, ligamentous, and meniscal injuries was determined and correlated to the sulcus angle, tibial tubercle trochlear groove distance, and patellar height on magnetic resonance imaging (MRI) scans. A total of 101 patients was identified. At arthroscopy, the patella demonstrated the highest incidence of chondral injury (68%) followed by the trochlear groove (40%). Lateral meniscal injuries were noted in 6% of patients, medial meniscal injuries in 2%, and anterior cruciate ligament (ACL) injury in 3%. Chondral injuries were graded using the Outerbridge criteria and there was a correlation between more severe chondral injuries and a greater tilt angle (p = 0.05). The occurrence of injury to the lateral meniscus was associated with a higher Insall-Salvati ratio (p = 0.05). More severe chondral injuries are seen in patients with a greater tilt angle.

Biomarkers in Painful Symptomatic Knee OA Demonstrate That MRI Assessed Joint Damage and Type II Collagen Degradation Products Are Linked to Disease Progression.

BACKGROUND: Osteoarthritis (OA) is the most prevalent arthritis worldwide, but the evolution of pain in relation to joint damage and biochemical markers are not well understood. We evaluated the relation between clinical pain measures and evoked pain in relation to structural damage and biochemical biomarkers in knee OA. METHODS: A cross-sectional study in people with knee OA and healthy controls was conducted. A total of 130 participants with advanced OA requiring total knee replacement (TKR) (n = 78), mild OA having standard care (n = 42) and non-OA controls (n = 6), with four drop-outs were assessed. Pain scoring was performed by the Western Ontario and McMaster Universities OA Index (WOMAC_P) and the Visual Analog Scale (VAS). Pain sensitization was assessed by pain pressure thresholds (PPTs). Knee magnetic resonance imaging (MRI) assessed joint damage using the MRI Knee OA Score (MOAKS). Overall MOAKS scores were created for bone marrow lesions (BMLs), cartilage degradation (CD), and effusion/Hoffa synovitis (tSyn). Type II collagen cleavage products (CTX-II) were determined by ELISA. RESULTS: The advanced OA group had a mean age of 68.9 ± 7.7 years and the mild group 63.1 ± 9.6. The advanced OA group had higher levels of pain, with mean WOMAC_P of 58.8 ± 21.7 compared with the mild OA group of 40.6 ± 26.0. All OA subjects had pain sensitization by PPT compared with controls (p < 0.05). WOMAC_P correlated with the total number of regions with cartilage damage (nCD) (R = 0.225, p = 0.033) and total number of BMLs (nBML) (R = 0.195, p = 0.065) using body mass index (BMI), age, and Hospital Anxiety and Depression Scale (HADS) as covariates. Levels of CTX-II correlated with tSyn (R = 0.313, p = 0.03), nBML (R = 0.252, p = 0.019), number of osteophytes (R = 0.33, p = 0.002), and nCD (R = 0.218, p = 0.042), using BMI and age as covariates. A multivariate analysis indicated that BMI and HADS were the most significant predictors of pain scores (p < 0.05). CONCLUSION: People with both mild and advanced OA show features of pain sensitization. We found that increasing MRI-detected joint damage was associated with higher levels of CTX-II, suggesting that increasing disease severity can be assessed by MRI and CTX-II biomarkers to evaluate OA disease progression.

Microarray analysis of bone marrow lesions in osteoarthritis demonstrates upregulation of genes implicated in osteochondral turnover, neurogenesis and inflammation.

OBJECTIVE: Bone marrow lesions (BMLs) are well described in osteoarthritis (OA) using MRI and are associated with pain, but little is known about their pathological characteristics and gene expression. We evaluated BMLs using novel tissue analysis tools to gain a deeper understanding of their cellular and molecular expression. METHODS: We recruited 98 participants, 72 with advanced OA requiring total knee replacement (TKR), 12 with mild OA and 14 non-OA controls. Participants were assessed for pain (using Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)) and with a knee MRI (using MOAKS). Tissue was then harvested at TKR for BML analysis using histology and tissue microarray. RESULTS: The mean (SD) WOMAC pain scores were significantly increased in advanced OA 59.4 (21.3) and mild OA 30.9 (20.3) compared with controls 0.5 (1.28) (p<0.0001). MOAKS showed all TKR tissue analysed had BMLs, and within these lesions, bone marrow volume was starkly reduced being replaced by dense fibrous connective tissue, new blood vessels, hyaline cartilage and fibrocartilage. Microarray comparing OA BML and normal bone found a significant difference in expression of 218 genes (p<0.05). The most upregulated genes included stathmin 2, thrombospondin 4, matrix metalloproteinase 13 and Wnt/Notch/catenin/chemokine signalling molecules that are known to constitute neuronal, osteogenic and chondrogenic pathways. CONCLUSION: Our study is the first to employ detailed histological analysis and microarray techniques to investigate knee OA BMLs. BMLs demonstrated areas of high metabolic activity expressing pain sensitisation, neuronal, extracellular matrix and proinflammatory signalling genes that may explain their strong association with pain.

Transvaginal ultrasound-guided aspiration of an anterior sacral meningocele masquerading as a hydrosalpinx, resulting in abscess formation.

Anterior sacral meningoceles (ASMs) have a recognized association with a number of connective tissue disorders, including Marfan's syndrome, neurofibromatosis Type 1 and Ehlers-Danlos syndrome. We present the case of a patient with Marfan's syndrome and ASMs who was referred to gynaecology owing to dysmenorrhoea and left-sided pelvic pain radiating to the left leg. A transvaginal ultrasound scan (TVUS) detected a left pelvic cystic tubular structure, attributed to a hydrosalpinx, which, in retrospect, likely corresponded to the ASM. The patient went on to have TVUS-guided drainage of this cystic structure, resulting in an ASM abscess. It is difficult to distinguish ASM from the vastly more common hydrosalpinx using TVUS alone, and in patients with an atypical appearing posteriorly positioned cystic pelvic lesion or in the presence of underlying conditions known to be associated with ASMs, MRI should be considered before any interventional procedure to drain the suspected hydrosalpinx transvaginally. The patient was successfully treated using a minimally invasive CT-guided posterior trans-sacral drainage technique.

Radiological features do not predict failure of two-stage arthroplasty for prosthetic joint infection: a retrospective case-control study.

BACKGROUND: The management of prosthetic joint infection is complex and there is a lack of standardisation of approaches. We evaluated the role of plain film radiography in predicting prosthesis failure after the first stage of a two-stage revision procedure in a retrospective case-control study. METHODS: Plain films for 41 patients aged 46 to 87 years (mean 69) were assessed by two musculoskeletal specialist radiologists for seven features (retained or new metalwork, retained cement or restrictor, new fracture, local antimicrobial delivery system and drain) we hypothesised may predict for failure. Inter-observer agreement was assessed by Kappa score and logistic regression analysis was performed to evaluate the relationship of the seven radiological features adjusting for patient age, gender and number of previous revisions. RESULTS: There was substantial inter-observer agreement, with a Kappa score of 0.73 (95% CI 0.72-0.74) for all data points collected. Concordance was 100% for evaluating the presence or absence of an antimicrobial delivery system or drain, with lower consensus for evaluating cement (Kappa 0.60, 95% CI 0.35-0.84) and fractures (Kappa 0.59, 95% CI 0.31-0.87). None of the variables' conditions significantly predicted failure. CONCLUSIONS: Our findings support the opinion that surgical expertise which maximizes removal of foreign material is sufficient in conjunction with antibiotic therapy.

The diagnostic test accuracy of magnetic resonance imaging, magnetic resonance arthrography and computer tomography in the detection of chondral lesions of the hip.

BACKGROUND: The purpose of this study was to assess the diagnostic test accuracy of magnetic resonance imaging (MRI), magnetic resonance arthrography (MRA) and multidetector arrays in CT arthrography (MDCT) for assessing chondral lesions in the hip joint. MATERIALS AND METHODS: A review of the published and unpublished literature databases was performed to identify all studies reporting the diagnostic test accuracy (sensitivity/specificity) of MRI, MRA or MDCT for the assessment of adults with chondral (cartilage) lesions of the hip with surgical comparison (arthroscopic or open) as the reference test. All included studies were reviewed using the quality assessment of diagnostic accuracy studies appraisal tool. Pooled sensitivity, specificity, likelihood ratios and diagnostic odds ratios were calculated with 95 % confidence intervals using a random-effects meta-analysis for MRI, MRA and MDCT imaging. RESULTS: Eighteen studies satisfied the eligibility criteria. These included 648 hips from 637 patients. MRI indicated a pooled sensitivity of 0.59 (95 % CI: 0.49-0.70) and specificity of 0.94 (95 % CI: 0.90-0.97), and MRA sensitivity and specificity values were 0.62 (95 % CI: 0.57-0.66) and 0.86 (95 % CI: 0.83-0.89), respectively. The diagnostic test accuracy for the detection of hip joint cartilage lesions is currently superior for MRI compared with MRA. There were insufficient data to perform meta-analysis for MDCT or CTA protocols. CONCLUSIONS: Based on the current limited diagnostic test accuracy of the use of magnetic resonance or CT, arthroscopy remains the most accurate method of assessing chondral lesions in the hip joint.

Quantitative sensory testing in painful hand osteoarthritis demonstrates features of peripheral sensitisation.

Hand osteoarthritis (HOA) is a prevalent condition for which treatments are based on analgesia and physical therapies. Our primary objective was to evaluate pain perception in participants with HOA by assessing the characteristics of nodal involvement, pain threshold in each hand joint, and radiological severity. We hypothesised that inflammation in hand osteoarthritis joints enhances sensitivity and firing of peripheral nociceptors, thereby causing chronic pain. Participants with proximal and distal interphalangeal (PIP and DIP) joint HOA and non-OA controls were recruited. Clinical parameters of joint involvement were measured including clinical nodes, VAS (visual analogue score) for pain (0-100 mm scale), HAQ (health assessment questionnaire), and Kellgren-Lawrence scores for radiological severity and pain threshold measurement were performed. The mean VAS in HOA participants was 59.3 mm ± 8.19 compared with 4.0 mm ± 1.89 in the control group (P < 0.0001). Quantitative sensory testing (QST) demonstrated lower pain thresholds in DIP/PIP joints and other subgroups in the OA group including the thumb, metacarpophalangeal (MCPs), joints, and wrists (P < 0.008) but not in controls (P = 0.348). Our data demonstrate that HOA subjects are sensitised to pain due to increased firing of peripheral nociceptors. Future work to evaluate mechanisms of peripheral sensitisation warrants further investigation.

What makes osteoarthritis painful? The evidence for local and central pain processing.

OA is a chronic arthritic disease characterized by pain, local tissue damage and attempts at tissue repair. Historically, cartilage damage was believed to be the hallmark of OA. However, since cartilage is an avascular, aneural tissue, the mechanisms of pain are likely to be complex and influenced by non-cartilaginous structures in the joint including the synovium, bone and soft tissue. Imaging studies reveal the presence of synovitis and bone marrow lesions that may mediate pain. The presence of local joint inflammation and altered cartilage and bone turnover in OA implicates a potential role for a range of molecular mediators in OA pain. Mechanisms of pain perception may include the activation and release of local pro-inflammatory mediators such as prostaglandins and cytokines accompanied by the destruction of tissue, which is mediated by proteases. However, clinically, there is often disparity between the degree of pain perception and the extent of joint changes in subjects with OA. Such observations have prompted work to investigate the mechanisms of central pain perception in OA. Functional MRI has identified multiple areas of the brain that are involved in OA pain processing. These data demonstrate that pain perception in OA is complex in being influenced by local factors and activation of central pain-processing pathways. In this review, we will discuss current concepts underlying the pathophysiology of pain perception in OA and suggest possible directions for the future management of pain in this condition based on recent clinical studies.

Musculoskeletal manifestations of sickle cell disease.

Sickle cell disease results from the presence of abnormal beta globin chains within hemoglobin and may be manifested in anemia, vaso-occlusion, and superimposed infection. The gene that causes sickle cell disease is particularly prevalent in populations of African origin; approximately 8% of African Americans and 40% of the members of some African tribes carry the gene for hemoglobin S. Over time, the disease produces various musculoskeletal abnormalities as a result of chronic anemia; these include marrow hyperplasia, reversion of yellow marrow to red marrow, and, occasionally, extramedullary hematopoiesis. Familiarity with the imaging features of sickle cell disease is important for the diagnosis and management of complications. Ischemia and infarction are common complications that may have long-term effects on the growth of bone; these conditions have characteristic radiographic appearances. Infection may be more difficult to identify. Both infection and infarction may occur in muscle and soft tissue alone, without involving bone. However, osteomyelitis must be diagnosed early and treated immediately to prevent bone destruction and deformity; therefore, care must be taken to achieve an accurate diagnosis by identifying or excluding bone involvement. The clinical and radiographic features of acute osteomyelitis may be particularly difficult to distinguish from those of bone infarction. In that context, magnetic resonance (MR) imaging may be useful. At MR imaging, findings of cortical defects, adjacent fluid collections in soft tissue, and bone marrow enhancement are suggestive of infection.