Kirschner wires are commonly used in paediatric fractures, however, the requirement for removal and the possibility of pin site infection provides opportunity for the development of new techniques that eliminate these drawbacks. Bioabsorbable pins that remain in situ and allow definitive closure of skin at the time of insertion could provide such advantages. Three concurrent studies were performed to assess the viability of bioabsorbable pins across the growth plate. (1) An epidemiological study to identify Kirschner wire infection rates. (2) A mechanical assessment of a bioabsorbable pin compared to Kirschner wires in a simulated supracondylar fracture. (3) The insertion of the implants across the physis of sheep to assess effects of the bioabsorbable implant on the growth plate via macroscopic, pathohistological and micro-CT analysis. An infection rate of 8.4% was found, with a deep infection rate of 0.4%. Mechanically the pins demonstrated comparable resistance to extension forces (p=) but slightly inferior resistance to rotation (p=). The in vivo component showed that at 6 months: there was no leg length discrepancy (p=0.6), with micro-CT evidence of normal physeal growth without tethering, and comparable physeal width (p=0.3). These studies combine to suggest that bioabsorbable pins do not represent a threat to the growth plate and may be considered for physeal fracture fixation.
Simulation in surgical training has become a key component of surgical training curricula, mandated by the GMC, however commercial tools are often expensive. As training budgets become increasingly pressurised, low-cost innovative simulation tools become desirable. We present the results of a low-cost, high-fidelity simulator developed in-house for teaching fluoroscopic guidewire insertion. A guidewire is placed in a 3d-printed plastic bone using simulated fluoroscopy. Custom software enables two inexpensive web cameras and an infra-red led marker to function as an accurate computer navigation system. This enables high quality simulated fluoroscopic images to be generated from the original CT scan from which the bone model is derived and measured guidewire position. Data including time taken, number of simulated radiographs required and final measurements such as tip apex distance (TAD) are collected. The simulator was validated using a DHS model and integrated assessment tool. TAD improved from 16.8mm to 6.6mm (p=0.001, n=9) in inexperienced trainees, and time taken from 4:25s to 2m59s (p=0.011). A control group of experienced surgeons showed no improvement but better starting points in TAD, time taken and number of radiographs. We have also simulated cannulated hip screws, femoral nail entry point and SUFE, but the system has potential for simulating any procedure requiring fluoroscopic guidewire placement e.g. pedicle screws or pelvic fixation. The low cost and 3D-printable nature have enabled multiple copies to be built. The software is open source allowing replication by any interested party. The simulator has been incorporated successfully into a higher orthopaedic surgical training program.
Controversy remains as to whether the contralateral hip should be fixed in patients presenting with unilateral slipped capital femoral epiphysis (SCFE). This study compares the outcomes of those patients who had prophylactic fixation with those who did not. We identified 90 consecutive patients with a mean age of 12.3 years presenting to the study centre with SCFE from a prospective operative database. The patient's notes and radiographs were retrospectively analysed for post-operative complications, re-presentation with a contralateral slip, and the presence of a cam lesion. The mean length of follow-up was 8 years (range 3 to 13). Fifty patients (56%) underwent unilateral fixation and 40 patients underwent bilateral fixation, of which 4 (4%) patients had simultaneous bilateral SCFE and 36 (40%) had prophylactic fixation of the contralateral hip. Twenty-three patients (46%) that underwent unilateral fixation, went onto have contralateral fixation for a further SCFE. Two patients from this group had symptomatic femoracetabular impingement from cam lesions and one patient required a Southwick osteotomy for a severe slip. Five patients (10%) that had unilateral fixation only demonstrated cam lesions on radiographic analysis, being suggestive of an asymptomatic slip. No post-operative complications were observed for the contralateral hip in patients that had prophylactic screw fixation and no cam lesions were identified on radiographic assessment. This study suggests that the contralateral hip in patients presenting with unilateral SCFE should be routinely offered prophylactic fixation to avoid a further slip, which may be severe, and the morbidity associated with a secondary cam lesion.
We studied the outcome and functional status of 33 patients with 34 severe open tibial fractures (Gustilo grade IIIb and IIIc). The treatment regime consisted of radical debridement, immediate bony stabilisation and early soft-tissue cover using a muscle flap (free or rotational). The review included standardised assessments of health-related quality of life (SF-36 and Euroqol) and measurement of the following parameters: gait, the use of walking aids, limb-length discrepancy, knee and ankle joint function, muscle wasting and the cosmetic appearance of the limb. Personal comments and overall patient satisfaction were also recorded. The mean follow-up was 46 months (15 to 80). There were 30 Gustilo grade IIIb fractures and and four grade IIIc fractures. Of the 33 patients, 29 had primary internal fixation and four, external fixation; 11 (34%) later required further surgery to achieve union and two needed bone transport procedures to reconstruct large segmental defects. The mean time to union was 41 weeks (12 to 104). Two patients (6.1%) developed deep infection; both resolved with treatment. The mean SF-36 physical and mental scores were 49 and 62 respectively. The mean state of health score for the Euroqol was 68. Patients with isolated tibial fractures had a better outcome than those with other associated injuries on both scoring systems. Knee stiffness was noted in seven patients (21%) and ankle stiffness in 19 (56%); 12 patients (41%) returned to work. Our results compare favourably with previous outcome measurements published for both limb salvage and amputation. All patients were pleased to have retained their limbs.