Traditionally, unstable anterior pelvic ring injuries have been stabilised with an external fixator or by internal fixation. Recently, a new percutaneous technique of placement of bilateral supraacetabular polyaxial screws and subcutaneous connecting bar to assemble an “internal fixator” has been described.

We present the surgical technique and early clinical results of using this technique in twenty-five consecutive patients with a rotationally unstable pelvic ring injury and no diastasis of the symphysis pubis treated between April 2010 and December 2013. Additional posterior pelvic stabilisation with percutaneous iliosacral screws was used in 23 of these patients. The anterior device was routinely removed after three months.

Radiological evidence of union of the anterior pelvic ring was seen in 24 of 25 patients at a minimum 6 month follow-up. Thirteen patients developed sensory deficits in the lateral femoral cutaneous nerve (five bilateral) and only one fully recovered.

The anterior pelvic internal fixator is a reliable, safe and easy percutaneous technique for the treatment of anterior pelvic ring injuries, facilitating the reduction and stabilisation of rotational displacement. However, lateral femoral cutaneous nerve dysfunction is common. The technique is recommended in cases with bilateral or unilateral pubic rami fractures and no diastasis of the symphysis pubis.

Stable, anatomical fixation of acetabular fractures gives the best chance of a good outcome. We performed a biomechanical study to compare fracture stability and construct stiffness of three methods of fixation of posterior wall acetabular fractures.

Two-dimensional motion analysis was used to measure fracture fragment displacement and the construct stiffness for each fixation method was calculated from the force / displacement data.

Following 2 cyclic loading protocols of 6000 cycles, to a maximum 1.5kN, the mean fracture displacement was 0.154mm for the rim plate model, 0.326mm for the buttress plate and 0.254mm for the spring plate model. Mean maximum displacement was significantly less for the rim plate fixation than the buttress plate (p=0.015) and spring plate fixation (p=0.02).

The rim plate was the stiffest construct 10962N/mm (SD 3351.8), followed by the spring plate model 5637N/mm (SD 832.6) and the buttress plate model 4882N/mm (SD 387.3).

Where possible a rim plate with inter-fragmentary lag screws should be used for isolated posterior wall fracture fixation as this is the most stable and stiffest construct. However, when this method is not possible, spring plate fixation is a safe and superior alternative to a posterior buttress plate method.

Introduction

Pelvic and acetabular injuries are relatively rare and surgical reconstruction usually occurs only in specialist centres. As part of their work up there is a local protocol for radiological investigations including Judet oblique views for acetabular fractures, pelvic inlet and outlet for pelvic ring fractures and urethrograms for sustaining anterior pelvic injury. The aim of this service evaluation was to assess whether patients had these radiological investigations prior to transfer.

Controversy exists whether to treat unstable pertrochanteric hip fractures with either intra-medullary or extra-medullary devices. A prospective randomised control trial was performed to compare the outcome of unstable pertrochanteric hip fractures stabilised with either a sliding hip screw or long Gamma Nail. The hypothesis was that there is no difference in outcome between the two modes of treatment.

Over a four year period, 210 patients presenting with an unstable pertrochanteric hip fracture (AO/OTA 31 A2) were recruited into the study. Eligible patients were randomised on admission to either long Gamma Nail or sliding hip screw. Follow-up was arranged for three, six, and twelve months. Primary outcome measures were implant failure or ‘cut-out’. Secondary measures included mortality, length of hospital stay, transfusion rate, change in mobility and residence, and EuroQol outcome score.

Five patients required revision surgery for implant cut-out (2.5%), of which three were long Gamma Nails and two were sliding hip screws (no significant difference). There were no incidences of implant failure or deep infection. Tip apex distance was found to correlate with implant cut-out. There was no statistically significant difference in either the EuroQol outcome scores or mortality rates between the two groups when corrected for mini mental score. There was no difference in transfusion rates, length of hospital stay, and change in mobility or residence. There was a clear cost difference between the implants.

The sliding hip screw remains the gold standard in the treatment of unstable pertrochanteric fractures of the proximal femur.

There is controversy regarding the optimum method of stabilising traumatic anterior pelvic ring injuries. This study aimed to evaluate the role of pubic symphysis plating.

Controversy exists whether a single proximal lateral tibia (PLT) locked plate is adequate for bicondylar fractures and whether the use of integral raft screws makes the use of bone graft less important.

57 consecutive patients who underwent reconstruction with a locked PLT plate were retrospectively reviewed. Radiographs were examined for operative reduction and subsequent loss of reduction.

55 patients were followed-up for an average of 27 weeks. Fractures were divided into unicondylar (Group 1, n=33) and bicondylar (Group 2, n=22). Union occurred in all patients, with no revisions or removal of metalwork at final follow-up. In 50 patients (88%), the fracture was reduced to within 2mm of anatomical. Articular surface collapse of >2mm occurred in three patients. Nine patients underwent bone grafting with no difference in outcome. A supplementary medial plate was used in three patients with a separate posteromedial fragment.

Except for a separate posteromedial fragment, the use of a single locked PLT plate for bicondylar fractures allows union to occur without failure. With the use of integral raft screws, the need for bone graft is questionable. The short-term radiological results and complication rate of PLT locked plating is excellent.

The purpose of this study was to assess the clinical and radiological outcome following spring plate fixation of posterior wall fractures.

Spring plates are fashioned from a one third tubular plate cutting through one of the holes in the plate and bending the sharp edges through 90 degrees allowing screw fixation of small acetabular margin fragments well away from the joint reducing the risk of joint penetration.

From July 1993 to August 2004, 89 patients with displaced posterior wall fractures underwent posterior wall fixation with one or more spring plates. Patients were assessed post-operatively with a CT scan and annually for up to 5 years for a clinical and radiological assessment. Clinically patients were graded according to the Epstein modification of Merle d'Aubigné/Postel Hip Score. The radiographs were graded using the Roentographic Grade criteria used by Matta.

Patients were reviewed at a mean 55 month follow-up. There were 12 post-operative complications. Clinically excellent or good results were seen in 70% and radiologically in 70%. There were 15 revisions for osteonecrosis, infection and osteoarthritis. 91% (20/22) of fractures had excellent/good clinical results if reduced anatomically compared with 66% (24/36) of those reduced to within 2mm as assessed by the post-operative CT scan. Only 44% (8/18) of those reduced leaving a gap of greater than 2mm had an excellent/good clinical result.

Posterior wall fractures can be treated successfully by the use of spring plates. Clinical results correspond closely with radiological appearance. The accuracy of reduction correlates highly with the subsequent prognosis and we recommend routine post-operative CT scanning to identify misplaced metalwork and the accuracy of reduction to help predict prognosis.