The procedures of total elbow and shoulder replacements increased 6% to 13% annually from 1993 to 2007 with revision-related burden increasing from 4.5% to 7%. The revisions of the shoulder and elbow prostheses due to aseptic loosening, periprosthetic fractures, infections have led to the use of standard or custom-made implants due to significant bone loss. This study reports our experience in the management of complicated primary and revisions of total shoulder and elbow replacements with significant humeral bone loss and in metabolic diseases of the elbow and shoulder treated with bone resection using The Mosaic Humeral Replacement System. A total of 20 patients underwent total elbow or shoulder arthroplasty using the Mosaic Humeral Replacement System (Biomet, UK). The Mosaic system was used in 8 shoulder arthroplasties (Group A) and in 12 elbow arthroplasties (Group B). The underlying pathologis in Group A included 2 malunited proximal humerus fracture, 1 humeral osteomyelitis, 1 shoulder chondrosarcoma, 1 aggressive Gigantic Cell Tumor with prosthetic fracture, 2 metastatic lytic lesion, and 1 failed fixation of non-union proximal humerus. Figure 1 shows Mosaic implant after complex fracture of proximal humerus. Reasons for Mosaic arthroplasty in Group B included 3 humeral component revisions due to periprosthetic fracture, 1 prosthesis breaking-up with fractures, 1 revision of loose Souter Strathclyde prosthesis, 1 loose prosthesis due to infection, 1 highly comminuted elbow fracture, 1 aseptic loosening of humeral component of total elbow replacement, 3 revision of total elbow replacement due loosening and 1 pathological distal humerus fracture due to metastasis. Figure 2&3 shows pre- and post-operative Mosaic implant following complex periprosthetic fracture of distal humerus.Background
Patients and Materials
To evaluate in-vivo the effectiveness of the double bundle technique for Anterior Cruciate ligament (ACL) reconstruction in restoring knee rotational stability under varying dynamic loading conditions. The study group included 10 patients who underwent double-bundle ACL reconstruction with hamstrings tendon autograft, 12 patients with single-bundle reconstruction, 10 ACL deficient subjects and 12 healthy control individuals. Kinematic and kinetic data were collected using an 8-camera optoelectronic motion analysis system and one force plate. Knee rotational stability was examined during two maneuvers: a combined 60o pivoting turn and immediate stairs ascend and a combined stairs descend and immediate 60o pivoting maneuver. The two factors evaluated were the maximum There were no significant differences in tibial rotation between the four groups in the examined maneuvers. Tibial rotation in the single- and the double-bundle groups were even lower than the control group. Rotational moments did not differ significantly between the four groups in any of the examined maneuvers. In general, rotational moments in the affected side of the ACL reconstructed and deficient groups were found reduced compared to the unaffected side. Double-bundle reconstruction does not reduce knee rotation further compared to the single-bundle technique during dynamic stability testing under varying conditions. The injured side of ACL reconstructed or deficient individuals is exposed to substantially lower rotational moment compared to the intact side.
