Purpose

Anterior column screw fixation has been a useful tool in the management of acetabular fractures, either alone or in combination with other fixation techniques. Percutaneous insertion may be advantageous by limiting surgical dissection but little has been reported on its safety. The purpose of this study is to report on the efficacy and safety of percutaneous anterior column stabilization.

Purpose: Intra-articular screw penetration with the use of proximal humeral locking plates has a reported incidence in the literature of up 25%. It may occur early, due to an intra-operative unrecognized technical error, or as a result of late fracture collapse. This study was designed to demonstrate the “approach-withdraw” technique of intra-operative fluoroscopy which can be used to minimize the rate of early unrecognized intra-articular screw penetration.

Method: A radiographic review was undertaken of 37 patients with proximal humerus fractures fixed with either the PHILOS plate (Synthes, Westchester, Pennsylvania) or the Periloc proximal humerus plate (Smith and Nephew, Memphis, TN) by the senior author (JY) between 2002 and 2009. Intra-operative fluoroscopy was used in each case to ensure there was no intra-articular screw encroachment by visualizing each screw tip approach and then withdraw from the articular surface during live fluoroscopy as the shoulder was taken through a range of motion. Patients were then followed for an average of nine months with serial radiographs for post-operative intra-articular screw penetration, screw loosening, and maintenance of reduction. Maintenance of reduction was evaluated using the change in neck shaft angle and greater tuberosity to humeral height difference on the initial post-operative x-rays as compared to the x-rays at final follow-up.

Results: An average of six screws (range three to nine) was placed into the humeral head per patient. There was no incidence of intra-articular screw penetration on immediate post-operative radiographs. One patient had loss of reduction with a single screw breaching the sub-chondral bone and four screws loosening after a fall in the early postoperative period. The remainder of patients had no evidence of intra-articular screw penetration or screw loosening at last follow-up. One patient developed a non-union and had a subsequent reconstruction. The average change in neck shaft angle was four degrees (range 0° to 16°) and greater tuberosity to humeral head height difference was 1.9 mm (range 0 – 8.9).

Conclusion: The approach-withdraw technique is a useful intra-operative fluoroscopic test which may be utilized in the fixation of proximal humerus fractures to avoid unrecognized intra-operative screw penetration of the glenohumeral joint.

Periacetabular osteotomy provides a joint preserving option for the treatment of acetabular dysplasia but is generally considered technically demanding, which has limited its widespread application. This study evaluates a new computer enhanced technique for a trans-trochanteric periacetabular osteotomy. This multi-use computer interface designed and used at Kingston General Hospital and Queen’s University has been previously and successfully used in many different types of surgical procedures. Interim results show few complications and accurate guidance.

To develop a new periacetabular osteotomy technique that can be performed safely and reliably using computer-enhanced technology.

This technique has enabled us to perform periacetabular osteotomies with few complications and increased accuracy of component alignment and sizing.

Using this computer-enhanced technique, periacetabular osteotomy may become a more common procedure in the practice of hip reconstruction.

Candidates include adults with symptomatic acetabular dysplasia. Pre-operative radiographs and CT scans are obtained. The scan is digitized to create a 3D model used for osteotomy planning. A trans-trochanteric approach is used to the acetabulum. An intra-operative plan is followed for osteotomy cuts. Fixation is achieved with two pelvic reconstruction plates. Peri-operative data on correction, complications and clinical data (WOMAC and SF36), and xrays and one year 3D CT scans are collected prospectively. This procedure has been performed on eighteen patients with an average centre edge angle correction of ninteen degrees. The computer guidance system has given accurate information in all but one case, which was successfully completed with limited guidance. No cases of intra-articular or posterior column fractures, nerve injury or AVN have occurred. Two cases of trochanteric pull-off were revised without complication. One case of delayed union of the pubic rami osteotomy was bone grafted and subsequently healed. One case of radiographic, but not clinical heterotropic ossification occurred in a patient with contraindications to prophylaxis. This new technique provides a reliable and reproducible option for acetabular correction with low complication rates.