MRI classification of calf injuries - a reliability study and correlation with return to play in professional rugby players.

OBJECTIVE: To assess the validity and reliability of the calf injury classification system proposed by the Olympic Park group which focuses on connective tissue structure integrity on MRI. MATERIALS AND METHODS: A retrospective study analysing calf muscle group injuries in an English Premiership professional rugby union club using the MRI classification proposed by the Olympic Park group. Classification on MRI examinations of 28 calf injuries sustained over a 6-year period was performed by three independent musculoskeletal radiologists to determine the inter-observer variability and correlation of the grade of injury with return-to-full-training (RTFT) time. RESULTS: RTFT time ranged from 5 to 110 days (mean = 40.1, SD = 26.4) following calf muscle injury. The Olympic Park classification injury grade demonstrated moderate to strong correlation with RTFT time (Spearman's rank correlation coefficient, 0.661-0.715, p < 0.01). RTFT time was statistically different between different injury grades (one-way ANOVA, p < 0.01). Inter-observer agreement of the overall grade between radiologist pairs was fair to moderate (weighted kappa 0.406-0.583). CONCLUSION: The Olympic Park classification system demonstrates moderate to strong correlation with time to RTFT following calf injury. Inter-observer reliability is fair to moderate.

Navigating the complexity of calf injuries in athletes: a review of MRI findings.

The calf muscle group is a common area for injury within the professional athlete population. Anatomical and biomechanical differences between the different component muscles vary their individual predispositions to and patterns of injury. However, there is a common unifying factor: injuries involving tendinous components have greater clinical implications with regards to rehabilitation, potential intervention, length of time to return to play, and re-injury rates. As such, accurate understanding of the underlying anatomy and subsequent interpretation of the injury patterns carry significant clinical ramifications. Ultrasound is a useful tool but has limitations, particularly when assessing soleus. As such, magnetic resonance imaging remains the workhorse in calf injury investigation.

The frondiform ligament sling: a sonographic landmark for injection into the sinus tarsi.

Localisation and injection of the sinus tarsi can be challenging, particularly for the less experienced musculoskeletal sonographer/practitioner. The inferior extensor retinaculum arises from the sinus tarsi in the form of three roots (medial, intermediate and lateral) which are collectively termed the frondiform ligament. This is readily identified on ultrasound and can be used as a reference point to aid the safe delivery of injectate material into the sinus tarsi. This article describes the technique and its anatomical basis.

Case report: Primary bone lymphoma presenting as a painful supraclavicular lump.

Primary bone lymphoma is a rare type of non-Hodgkin's lymphoma. It commonly arises from long bones such as the femur in the appendicular skeleton. The authors present a case of primary bone lymphoma of the clavicle, an uncommon location for this pathology, presenting as a painful supraclavicular lump in a 76-year-old woman. Magnetic resonance imaging and ultrasound examinations showed the typical feature of preservation of the bony cortex, and PET-CT revealed no alternative primary site of malignancy. This case highlights the importance of considering typical imaging characteristics of a lesion, even if it presents in an unusual site, as well as the value of completion imaging in clinical practice to secure a diagnosis.

A Rare Mutation in SMAD9 Associated With High Bone Mass Identifies the SMAD-Dependent BMP Signaling Pathway as a Potential Anabolic Target for Osteoporosis.

Novel anabolic drug targets are needed to treat osteoporosis. Having established a large national cohort with unexplained high bone mass (HBM), we aimed to identify a novel monogenic cause of HBM and provide insight into a regulatory pathway potentially amenable to therapeutic intervention. We investigated a pedigree with unexplained HBM in whom previous sequencing had excluded known causes of monogenic HBM. Whole exome sequencing identified a rare (minor allele frequency 0.0023), highly evolutionarily conserved missense mutation in SMAD9 (c.65T>C, p.Leu22Pro) segregating with HBM in this autosomal dominant family. The same mutation was identified in another two unrelated individuals both with HBM. In silico protein modeling predicts the mutation severely disrupts the MH1 DNA-binding domain of SMAD9. Affected individuals have bone mineral density (BMD) Z-scores +3 to +5, mandible enlargement, a broad frame, torus palatinus/mandibularis, pes planus, increased shoe size, and a tendency to sink when swimming. Peripheral quantitative computed tomography (pQCT) measurement demonstrates increased trabecular volumetric BMD and increased cortical thickness conferring greater predicted bone strength; bone turnover markers are low/normal. Notably, fractures and nerve compression are not found. Both genome-wide and gene-based association testing involving estimated BMD measured at the heel in 362,924 white British subjects from the UK Biobank Study showed strong associations with SMAD9 (PGWAS = 6 × 10-16 ; PGENE = 8 × 10-17 ). Furthermore, we found Smad9 to be highly expressed in both murine cortical bone-derived osteocytes and skeletal elements of zebrafish larvae. Our findings support SMAD9 as a novel HBM gene and a potential novel osteoanabolic target for osteoporosis therapeutics. SMAD9 is thought to inhibit bone morphogenetic protein (BMP)-dependent target gene transcription to reduce osteoblast activity. Thus, we hypothesize SMAD9 c.65T>C is a loss-of-function mutation reducing BMP inhibition. Lowering SMAD9 as a potential novel anabolic mechanism for osteoporosis therapeutics warrants further investigation. © 2019 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.