Understanding acute ankle ligamentous sprain injury in sports

This paper summarizes the current understanding on acute ankle sprain injury, which is the most common acute sport trauma, accounting for about 14% of all sport-related injuries. Among, 80% are ligamentous sprains caused by explosive inversion or supination. The injury motion often happens at the subtalar joint and tears the anterior talofibular ligament (ATFL) which possesses the lowest ultimate load among the lateral ligaments at the ankle. For extrinsic risk factors to ankle sprain injury, prescribing orthosis decreases the risk while increased exercise intensity in soccer raises the risk. For intrinsic factors, a foot size with increased width, an increased ankle eversion to inversion strength, plantarflexion strength and ratio between dorsiflexion and plantarflexion strength, and limb dominance could increase the ankle sprain injury risk. Players with a previous sprain history, players wearing shoes with air cells, players who do not stretch before exercising, players with inferior single leg balance, and overweight players are 4.9, 4.3, 2.6, 2.4 and 3.9 times more likely to sustain an ankle sprain injury. The aetiology of most ankle sprain injuries is incorrect foot positioning at landing – a medially-deviated vertical ground reaction force causes an explosive supination or inversion moment at the subtalar joint in a short time (about 50 ms). Another aetiology is the delayed reaction time of the peroneal muscles at the lateral aspect of the ankle (60–90 ms). The failure supination or inversion torque is about 41–45 Nm to cause ligamentous rupture in simulated spraining tests on cadaver. A previous case report revealed that the ankle joint reached 48 degrees inversion and 10 degrees internal rotation during an accidental grade I ankle ligamentous sprain injury during a dynamic cutting trial in laboratory. Diagnosis techniques and grading systems vary, but the management of ankle ligamentous sprain injury is mainly conservative. Immobilization should not be used as it results in joint stiffness, muscle atrophy and loss of proprioception. Traditional Chinese medicine such as herbs, massage and acupuncture were well applied in China in managing sports injuries, and was reported to be effective in relieving pain, reducing swelling and edema, and restoring normal ankle function. Finally, the best practice of sports medicine would be to prevent the injury. Different previous approaches, including designing prophylactice devices, introducing functional interventions, as well as change of games rules were highlighted. This paper allows the readers to catch up with the previous researches on ankle sprain injury, and facilitate the future research idea on sport-related ankle sprain injury

Abstract 5425: Quantitative determination of fibroblast growth factor receptor inhibitor-AZD4547 using HPLC analysis in a mouse model of ultraviolet B (UVB)-induced skin carcinogenesis

Abstract Cutaneous squamous cell carcinoma (cSCC) is the second most common form of skin cancer affecting more than two million Americans annually. Cumulative sun exposure plays a leading role in the pathogenesis of cSCC. In our previous studies, topical application of Fibroblast growth factor receptor (FGFR) inhibitor AZD4547 was associated with a significant reduction in Ultraviolet B-induced (UVB)-induced acute skin changes such as epidermal hyperplasia and hyperproliferation. Further, chronic, topical application of AZD4547 was associated with significant inhibition in UVB-induced tumor incidence and multiplicity. Unfortunately, oral administration of FGFR inhibitors in clinical trials for solid tumors is associated with notable side effects such as hyperphosphatemia, diarrhea, decreased appetite, fatigue, and liver dysfunction. Therefore, our objective was to investigate whether topical administration of AZD4547 could potentially circumvent systemic absorption, leading to a low toxicity profile. Accordingly, mice were topically administered AZD4547 (400ug/200ul acetone) followed by exposure to UVB three times a week for two weeks. Blood was collected at the end of the study. AZD4547 was extracted using methanol extraction and concentrated using a Savant SpeedVac system. Samples were reconstituted in 25% acetone/75% water solution and analyzed using Reverse-phase HPLC (Shimadzu) with a Zorbax Eclipse C18 3.5-µm 4.6x100mm analytical column operated at ambient temperature and gradient elution using trifluoroacetic acid (TFA) (Mobile A) and 0.1% TFA in Acetonitrile. Data from HPLC analysis demonstrated non-appreciable absorption of AZD4547 (blood levels only from 108-358nM) suggesting that the topical application of AZD4547 was not systemically absorbed and the effect of treatment was restricted to the local skin tissue. Based on the efficacy and low systemic absorption profile, AZD4547 could potentially be utilized as a topical agent to both prevent and treat UVB-induced cSCC. Citation Format: Rema Anisha Kandula, Katherine Claire Babin, Brian Latimer, Kenneth Mc Martin, Lauren Linquest, Tara Moore-Medlin, Megha A. Thakur, Alok R. Khandelwal, John DiGiovanni, Cherie-Ann O. Nathan. Quantitative determination of fibroblast growth factor receptor inhibitor-AZD4547 using HPLC analysis in a mouse model of ultraviolet B (UVB)-induced skin carcinogenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5425.</jats:p

Flatfoot in Müller-Weiss syndrome: a case series

<p>Abstract</p> <p>Introduction</p> <p>Spontaneous osteonecrosis of the navicular bone in adults is a rare entity, known as Müller-Weiss syndrome. We report here on our experience with six patients with Müller-Weiss syndrome accompanied by flatfoot deformity, but on a literature search found no reports on this phenomenon. Because the natural history and treatment are controversial, an understanding of how to manage this deformity may be helpful for surgeons when choosing the most appropriate operative procedure.</p> <p>Case presentation</p> <p>Six patients (five women, one man; average age, 54 years) with flatfoot caused by osteonecrosis of the navicular bone were followed up between January 2005 and December 2008 (mean follow-up period, 23.2 months). Conservative treatment, such as physical therapy, and non-steroidal anti-inflammatory drugs were used, but failed. Physical examinations revealed flattening of the medial arch of the involved foot and mild tenderness at the mid-tarsal joint. Weight-bearing X-rays (anterior-posterior and lateral views), computed tomography, and MRI scans were performed for each case. Talonavicular joint arthrodesis was performed in cases of single talonavicular joint arthritis. Triple arthrodesis was performed in cases of triple joint arthritis to reconstruct the medial arch. Clinical outcomes were assessed using the American Orthopaedic Foot and Ankle Society ankle-hindfoot scale; the scores were 63.0 pre-operatively and 89.8 post-operatively. All patients developed bony fusion.</p> <p>Conclusions</p> <p>The reason for the development of flatfoot in patients with Müller-Weiss syndrome is unknown. Surgical treatment may achieve favorable outcomes in terms of deformity correction, pain relief, and functional restoration. The choice of operative procedure may differ in patients with both flatfoot and posterior tibial tendon dysfunction.</p