Periprosthetic femoral fractures are a challenging problem to manage. In the literature various constructs have been designed and tested, most requiring cables for proximal fixation. The Synthes Locking Attachment Plate (LAP) has been designed to achieve proximal fixation without the use of cables. The aim of this study was to biomechanically evaluate the LAP construct in comparison to a Cable plate construct, for the fixation of periprosthetic femoral fractures after cemented total hip arthroplasty (THA). Twelve synthetic femora were tested in axial compression, lateral bending and torsion to determine initial stiffness, and stiffness following fixation of a simulated midshaft fracture with and without a bone gap. Two different fracture fixation constructs (six per group) were assessed. Each construct incorporated a broad curved LCP with bi-cortical locking screws for distal fixation. In the Cable construct, 2 cables and 2 uni-cortical locking screws were used for proximal fixation. In the LAP construct, the cables were replaced by a LAP with 4 bicortical locking screws. Axial, lateral bending and torsional stiffness were assessed using intact specimen values as a baseline. Axial load to failure was also measured. The LAP construct was significantly stiffer than the cable construct under axial load with a bone gap (simulating a comminuted fracture) (p=0.01). There were no significant differences between the two constructs in any of the other modalities tested. Loading to failure resulted in no significant differences between constructs, in either initial stiffness or peak load. In conclusion the LAP construct enables bi-cortical screw fixation around a prosthesis. Compared to cables, this was stiffer when there was a bone gap and thus should offer improved proximal fixation of Vancouver B1 proximal femoral fractures in cemented THA.
When patients with anterior impingement were questioned, 80 were found to have a history of cervical pain which was confirmed radiographically and/or on computed tomography (CT). Physical examination of the cervical spine revealed pain at pressure on the anterolateral aspect of the C4, C5, and C6 vertebrae, always homolateral to the impingement. Search for this sign has thus become part of our routine examination and, according to Maigne, confirms the vertebral origin of peripheral pain. We found it to be absent in anterior impingements caused by trauma in young subjects, and to be inconstant in traumatic anterior impingements observed in patients aged over 55 years. After cervical arthrodesis for cervicobrachial pain, we observed five cases of progressive anterior impingement requiring decompression. In their series of 76 cervical arthrodeses for cervicobrachialgia, Hawkins et al on observed 13 cases of proven anterior impingement. They concluded there must be a relation between these two conditions. Golg et al. provided a decisive contribution to the theory when the discovered that in anterior impingement patients, rotator cuff muscles exhibit specific histological markers of muscle denervation.
