In an interdisciplinary project involving electronic engineers and clinicians, a telemetric system was developed to measure the bending load in a titanium internal femoral fixator. As this was a new device, the main question posed was: what clinically relevant information could be drawn from its application? As a first clinical investigation, 27 patients (24 men, three women) with a mean age of 38.4 years (19 to 66) with femoral nonunions were treated using the system. The mean duration of the nonunion was 15.4 months (5 to 69). The elasticity of the plate-callus system was measured telemetrically until union. Conventional radiographs and a CT scan at 12 weeks were performed routinely, and healing was staged according to the CT scans. All nonunions healed at a mean of 21.5 weeks (13 to 37). Well before any radiological signs of healing could be detected, a substantial decrease in elasticity was recorded. The relative elasticity decreased to 50% at a mean of 7.8 weeks (3.5 to 13) and to 10% at a mean of 19.3 weeks (4.5 to 37). At 12 weeks the mean relative elasticity was 28.1% (0% to 56%). The relative elasticity was significantly different between the different healing stages as determined by the CT scans.

Incorporating load measuring electronics into implants is a promising option for the assessment of bone healing. Future application might lead to a reduction in the need for exposure to ionising radiation to monitor fracture healing.

Aims. The anterior pelvic internal fixator is increasingly used for the treatment of unstable, or displaced, injuries of the anterior pelvic ring. The evidence for its use, however, is limited. The aim of this paper is to describe the indications for its use, how it is applied and its complications. Patients and Methods. We reviewed the case notes and radiographs of 50 patients treated with an anterior pelvic internal fixator between April 2010 and December 2015 at a major trauma centre in the United Kingdom. The median follow-up time was 38 months (interquartile range 24 to 51). Results. Three patients were excluded from the analysis leaving 47 patients with complete follow-up data. Of the 47 patients, 46 achieved radiological union and one progressed to an asymptomatic nonunion. Of the remaining patients, 45 required supplementary posterior fixation with percutaneous iliosacral screws, 2 of which required sacral plating. The incidence of injury to the lateral femoral cutaneous nerve (LFCN) was 34%. The rate of infection was 2%. There were no other significant complications. Without this treatment, 44 patients (94%) would have needed unilateral or bilateral open reduction and plate fixation extending laterally to the hip joint. Conclusion. The anterior pelvic internal fixator reduces the need for extensive open surgery and is a useful addition to the armamentarium for the treatment of anterior pelvic injuries. It is associated with injury to the LFCN in a third of patients. Cite this article: Bone Joint J 2017;99-B.1232–6

We performed a retrospective review of the case notes of 84 consecutive patients who had suffered a severe (Gustilo IIIb or IIIc) open fracture of the tibia after blunt trauma between 1990 and 1998. All had been treated by a radical protocol which included early soft-tissue cover with a muscle flap by a combined orthopaedic and plastic surgery service. Our ideal management is a radical debridement of the wound outside the zone of injury, skeletal stabilisation and early soft-tissue cover with a vascularised muscle flap. All patients were followed clinically and radiologically to union or for one year. After exclusion of four patients (one unrelated death and three patients lost to follow-up), we reviewed 80 patients with 84 fractures. There were 67 men and 13 women with a mean age of 37 years (3 to 89). Five injuries were grade IIIc and 79 grade IIIb; 12 were site 41, 43 were site 42 and 29 were site 43. Debridement and stabilisation of the fracture were invariably performed immediately. In 33 cases the soft-tissue reconstruction was also completed in a single stage, while in a further 30 it was achieved within 72 hours. In the remaining 21 there was a delay beyond 72 hours, often for critical reasons unrelated to the limb injury. All grade-IIIc injuries underwent immediate vascular reconstruction, with an immediate cover by a flap in two. All were salvaged. There were four amputations, one early, one mid-term and two late, giving a final rate of limb salvage of 95%. Overall, nine pedicled and 75 free muscle flaps were used; the rate of flap failure was 3.5%. Stabilisation of the fracture was achieved with 19 external and 65 internal fixation devices (nails or plates). Three patients had significant segmental defects and required bone-transport procedures to achieve bony union. Of the rest, 51 fractures (66%) progressed to primary bony union while 26 (34%) required a bone-stimulating procedure to achieve this outcome. Overall, there was a rate of superficial infection of the skin graft of 6%, of deep infection at the site of the fracture of 9.5%, and of serious pin-track infection of 37% in the external fixator group. At final review all patients were walking freely on united fractures with no evidence of infection. The treatment of these very severe injuries by an aggressive combined orthopaedic and plastic surgical approach provides good results; immediate internal fixation and healthy soft-tissue cover with a muscle flap is safe. Indeed, delay in cover (> 72 hours) was associated with most of the problems. External fixation was associated with practical difficulties for the plastic surgeons, a number of chronic pin-track infections and our only cases of malunion. We prefer to use internal fixation. We recommend primary referral to a specialist centre whenever possible. If local factors prevent this we suggest that after discussion with the relevant centre, initial debridement and bridging external fixation, followed by transfer, is the safest procedure

Aims

The best method of treating unstable pelvic fractures that involve the obturator ring is still a matter for debate. This study compared three methods of treatment: nonoperative, isolated posterior fixation and combined anteroposterior stabilization.

The increasing prevalence of osteoporosis in an ageing population has contributed to older patients becoming the fastest-growing group presenting with acetabular fractures. We performed a systematic review of the literature involving a number of databases to identify studies that included the treatment outcome of acetabular fractures in patients aged > 55 years. An initial search identified 61 studies; after exclusion by two independent reviewers, 15 studies were considered to meet the inclusion criteria. All were case series. The mean Coleman score for methodological quality assessment was 37 (25 to 49). There were 415 fractures in 414 patients. Pooled analysis revealed a mean age of 71.8 years (55 to 96) and a mean follow-up of 47.3 months (1 to 210). In seven studies the results of open reduction and internal fixation (ORIF) were presented: this was combined with simultaneous hip replacement (THR) in four, and one study had a mixture of these strategies. The results of percutaneous fixation were presented in two studies, and a single study revealed the results of non-operative treatment.

With fixation of the fracture, the overall mean rate of conversion to THR was 23.1% (0% to 45.5%). The mean rate of non-fatal complications was 39.8% (0% to 64%), and the mean mortality rate was 19.1% (5% to 50%) at a mean of 64 months (95% confidence interval 59.4 to 68.6; range 12 to 143). Further data dealing with the classification of the fracture, the surgical approach used, operative time, blood loss, functional and radiological outcomes were also analysed.

This study highlights that, of the many forms of treatment available for this group of patients, there is a trend to higher complication rates and the need for further surgery compared with the results of the treatment of acetabular fractures in younger patients.

Cite this article: Bone Joint J 2014;96-B:157–63.

We investigated the static and cyclical strength of parallel and angulated locking plate screws using rigid polyurethane foam (0.32 g/cm³) and bovine cancellous bone blocks. Custom-made stainless steel plates with two conically threaded screw holes with different angulations (parallel, 10° and 20° divergent) and 5 mm self-tapping locking screws underwent pull-out and cyclical pull and bending tests. The bovine cancellous blocks were only subjected to static pull-out testing. We also performed finite element analysis for the static pull-out test of the parallel and 20° configurations. In both the foam model and the bovine cancellous bone we found the significantly highest pull-out force for the parallel constructs. In the finite element analysis there was a 47% more damage in the 20° divergent constructs than in the parallel configuration. Under cyclical loading, the mean number of cycles to failure was significantly higher for the parallel group, followed by the 10° and 20° divergent configurations.

In our laboratory setting we clearly showed the biomechanical disadvantage of a diverging locking screw angle under static and cyclical loading.

Percutaneous stabilisation of tibial fractures by locking plates has become an accepted form of osteosynthesis. A potential disadvantage of this technique is the risk of damage to the neurovascular bundles in the anterior and peroneal compartments. Our aim in this anatomical study was to examine the relationship of the deep peroneal nerve to a percutaneously-inserted Less Invasive Stabilisation System tibial plate in the lower limbs of 18 cadavers. Screws were inserted through stab incisions. The neurovascular bundle was dissected to reveal its relationship to the plate and screws.

In all cases, the deep peroneal nerve was in direct contact with the plate between the 11th and the 13th holes. In ten specimens the nerve crossed superficial to the plate, in six it was interposed between the plate and the bone and in the remaining two specimens it coursed at the edge of the plate.

Percutaneous insertion of plates with more than ten holes is not recommended because of the risk of injury to the neurovascular structures. When longer plates are required we suggest distal exposure so that the neurovascular bundle may be displayed and protected.

The treatment of infected exposed implants which have been used for internal fixation usually involves debridement and removal of the implant. This can result in an unstable fracture or spinal column. Muscle flaps may be used to salvage these implants since they provide soft-tissue cover and fresh vascularity. However, there have been few reports concerning their use and these have concentrated on the eradication of the infection and successful soft-tissue cover as the endpoint. There is no information on the factors which may influence the successful salvage of the implant using muscle flaps.

We studied the results and factors affecting outcome in nine pedicled muscle flaps used in the treatment of exposed metal internal fixation with salvage of the implant as the primary endpoint. This was achieved in four cases. Factors predicting success were age < 30 years, the absence of comorbid conditions and a favourable microbiological profile. The growth of multiple organisms, a history of smoking and the presence of methicillin-resistant Staphylococcus aureus on wound cultures indicated a poor outcome. The use of antibiotic beads, vacuum-assisted closure and dressing, the surgical site, the type of flap performed and the time from primary surgery to flap cover were not predictive of outcome.

The results of meta-analysis show a revision rate of 33% for internal fixation of displaced fractures of the femoral neck, mostly because of nonunion. Osteopenia and osteoporosis are highly prevalent in elderly patients. Bone density has been shown to correlate with the intrinsic stability of the fixation of the fracture in cadaver and retrospective studies. We aimed to confirm or refute this finding in a clinical setting.

We performed a prospective, multicentre study of 111 active patients over 60 years of age with a displaced fracture of the femoral neck which was eligible for internal fixation. The bone density of the femoral neck was measured pre-operatively by dual-energy x-ray absorptiometry (DEXA). The patients were divided into two groups namely, those with osteopenia (66%, mean T-score −1.6) and those with osteoporosis (34%, mean T-score −3.0). Age (p = 0.47), gender (p = 0.67), delay to surgery (p = 0.07), the angle of the fracture (p = 0.33) and the type of implant (p = 0.48) were similar in both groups.

Revision to arthroplasty was performed in 41% of osteopenic and 42% of osteoporotic patients (p = 0.87). Morbidity (p = 0.60) and mortality were similar in both groups (p = 0.65). Our findings show that the clinical outcome of internal fixation for displaced fractures of the femoral neck does not depend on bone density and that pre-operative DEXA is not useful.