Triple-tapered cemented stems were developed in the hope that they would reduce aseptic loosening and prevent calcar bone loss. Between March 2005 and April 2008, a consecutive series of 415 primary C-stem AMT hip arthroplasties in 386 patients were performed under the care of three surgeons at our institution. When all the patients had reached the 5-year anniversary of surgery, functional questionnaires were sent out by mail. In the event of non-response, reminders were sent by post before the patients were contacted by telephone. Postoperative radiographs were also reviewed. Follow-up ranges from 60 to 99 months, with a mean of 76 months. 32 hips (8%) were lost to follow-up. The median OHS was 40, median SF-12 mental component score (MCS) was 50, and median SF-12 physical component score (PCS) was 39. Radiographic review showed that aseptic femoral component loosening has yet to be observed. At 99 months follow up, stem survivorship is 96.9% (95% confidence interval (CI) 82.5 to 99.5). Adverse events such as calcar fracture, greater trochanter fracture and dislocation were rare at <1%. The C-stem AMT demonstrates excellent implant survivorship at 5–8 year follow-up, as well as good midterm functional outcome.
Separation of the ACL into anteromedial (AM) and posterolateral (PL) fibre bundles has been widely accepted. The bundles act synergistically to restrain anterior laxity throughout knee flexion, with the PL bundle providing the more important restraint near extension and its obliquity better restraining tibial rotational laxity. 10% of ACL injuries involve isolated rupture to one of these bundles causing patients to present with instability symptoms or pain. As knowledge about the influence of the ACL bundles on knee kinematics has increased, isolated reconstruction of either PL or AM bundle has been advocated. However only one cohort study of 17 patients has been presented in the clinical literature. KOOS (Knee Injury and Osteoarthritis Outcome Score) and IKDC (International Knee Documentation Committee Form) scores at 1yr post op were obtained for 12 patients who had undergone isolated ACL augmentation between 2007 and 2009. These were compared with previously published outcome scores for standard ACL reconstruction procedures. In addition examination under anaesthesia (EUA) assessments were analysed to see if a pattern of laxity for isolated AM and PL rupture could be determined. There were 5 patients with isolated AM bundle rupture and 7 with isolated PL bundle rupture. EUA analysis demonstrated that patients with isolated PL bundle rupture had increased pivot shift and Lachman test laxity, whereas the AM bundle rupture group had increased laxity with the anterior drawer test. Compared to previously published IKDC scores, there were no difference between isolated bundle augmentation and standard ACL reconstruction. However the KOOS scores showed significantly increased Sports function scores which was significantly better in the isolated bundle augmentations (93/100 v's 74/100). Differences between isolated AM and PL bundle reconstructions were not distinguishable. Isolated ACL bundle tears make up a significant proportion ACL injuries. Although technically more difficult than standard ACL reconstruction, isolated bundle augmentation appears to result in improved sports function when compared to standard ACL reconstruction.
