Collagen is a key component of the extracellular matrix in a variety of tissues and hence is widely used in tissue engineering research, yet collagen has had limited uptake in the field of 3D printing. In this study we successfully adapted an existing electronic printing method, aerosol jet printing (AJP), to print high resolution 3D constructs of recombinant collagen type III (RHCIII). Circular samples with a diameter of 4.5mm and 288 layers thick, or a diameter of 6.5mm and 400 layers thick were printed on glass cover slips with print lines of 60µm. Attenuated Total Reflectance Fourier-Transorm Infa-red (ATR-FTIR) spectroscopy performed on the 4 of the printed samples and dried non-printed RHCIII samples showed that no denaturation had occurred due to the printing process. Printed samples were crosslinked using EDC [N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride, Sigma Aldrich] to improve their stability and mechanical strength. Differential scanning calorimetry (DSC) performed showed a marked difference in the denaturation temperature between crosslinked printed samples and fibrillar non-printed samples and nano-indentation showed that the construct was relatively stiff. Previous results with similar samples have shown that mesenchymal stem cells (MSCs) align with and travel parallel to print direction. Results obtained from these samples show signs that they might be applied in other areas such as bone tissue engineering.

Introduction: Percutaneous repairs of Achilles tendon ruptures has gained popularity due the reduced incidence of wound complications, however its use is still limited by the high incidence of sural nerve injuries associated with these repairs. The only technique described to avoid this adverse event is to surgically expose the nerve peri – operatively.

Materials & Methods: In our study we describe and validate a clinical technique to identify the sural nerve. The technique describes flexing the knee to 90°, and supinating the forefoot and inverted the hindfoot. The sural nerve is at its greatest tension in this position and thus the nerve can be palpated along its path. The sural nerve was mapped using this technique both clinically and by US in a cohort of male subjects with intact Achilles tendons.

Results: We demonstrated an excellent correlation between the clinical and US mapping. It also showed excellent inter – observer and intra – observer mapping rates.

Discussion: Sural nerve injuries occur in up to 18% of percutaneous repairs due to the close proximity of the nerve to the tendon along its lateral border. The resultant pain or parasthesia experienced by the patient from sural nerve injuries results in a profound morbidity. This morbidity has lead to the reduced popularity of this procedure. The clinical mapping is a simple easy test, which identifies the nerve along its path and thus the nerve can be avoided during the procedure.

Conclusion: This study demonstrates an accurate and repeatable clinical technique for mapping the sural nerve in conjunction with percutaneous Achilles tendon repairs.

Aim: To evaluate the necessity for further radiological investigation in patients with suspicion of rotatory subluxation of the atlanto-axial complex on plain radiography following acute cervical trauma. To outline guidelines for assessment of patients with atlanto-axial asymmetry on plain radiography.

Methods: A retrospective review of all patients who had undergone atlanto-axial CT scanning as a result of radiographic C1–C2 asymmetry following cervical spine trauma in the 3 year period from January 1999 to December 2001. The plain X-ray and CT images were reviewed retrospectively and correlated with their clinical presentation and outcome by the senior author.

Results: Twenty-eight patients were included in the study. Acute cervical spine trauma had occurred most commonly following a road traffic accident. No patient was found to have acute cervical spine torticollis or severe cervical pain. Patients age ranged from 21–44 years (M:F – 15:13). All patients were found to have atlanto-odontoid asymmetry on initial plain X-ray. No patients were found to have rotatory subluxation on CT images. 3 patients were found to have minor degrees (< 10°) of rotation on the CT scan which is within normal limits. 9 patients (32%) were found to have congenital odontoid lateral mass asymmetry. All patients were treated conservatively and had no further intervention. All plain radiographs were then assessed to determine the underlying reason for asymmetry. In 19 cases the orientation of the radiographic beam in combination with head rotation was found to be at fault.

Conclusion: Rotatory subluxation of the cervical spine is a rare but serious condition in the adult. The condition is suspected radiologically in the presence of odontoid lateral mass asymmetry on open mouth view. The application of ATLS principles in the initial assessment of trauma patients has resulted in a significant increase in the number of radiological examinations performed. This has led inevitably to an increase in the number of anomalies identified. An average of 400 c-spine X-rays per year are performed for trauma in our casualty department. In this study, we have identified 9 patients out of a total of 29 with congenital odontoid lateral mass asymmetry over a 3 year period. This represents approximately 0.75% of the cervical spine X-rays and should be considered in the differential diagnosis following acute cervical trauma. We outline guidelines for recognising benign atlanto-axial asymmetry.