The early outcome of kinematic versus mechanical alignment in total knee arthroplasty: a prospective randomised control trial.

AIMS: Our aim was to compare kinematic with mechanical alignment in total knee arthroplasty (TKA). PATIENTS AND METHODS: We performed a prospective blinded randomised controlled trial to compare the functional outcome of patients undergoing TKA in mechanical alignment (MA) with those in kinematic alignment (KA). A total of 71 patients undergoing TKA were randomised to either kinematic (n = 36) or mechanical alignment (n = 35). Pre- and post-operative hip-knee-ankle radiographs were analysed. The knee injury and osteoarthritis outcome score (KOOS), American Knee Society Score, Short Form-36, Euro-Qol (EQ-5D), range of movement (ROM), two minute walk, and timed up and go tests were assessed pre-operatively and at six weeks, three and six months and one year post-operatively. RESULTS: A total of 78% of the kinematically aligned group (28 patients) and 77% of the mechanically aligned group (27 patients) were within 3° of their pre-operative plan. There were no statistically significant differences in the mean KOOS (difference 1.3, 95% confidence interval (CI) -9.4 to 12.1, p = 0.80), EQ-5D (difference 0.8, 95% CI -7.9 to 9.6, p = 0.84), ROM (difference 0.1, 95% CI -6.0 to 6.1, p = 0.99), two minute distance tolerance (difference 20.0, 95% CI -52.8 to 92.8, p = 0.58), or timed up and go (difference 0.78, 95% CI -2.3 to 3.9, p = 0.62) between the groups at one year. CONCLUSION: Kinematically aligned TKAs appear to have comparable short-term results to mechanically aligned TKAs with no significant differences in function one year post-operatively. Further research is required to see if any theoretical long-term functional benefits of kinematic alignment are realised or if there are any potential effects on implant survival. Cite this article: Bone Joint J 2016;98-B:1360-8.

A technique of fusion for failed total replacement of the ankle: tibio-allograft-calcaneal fusion with a locked retrograde intramedullary nail.

Salvage of a failed total ankle replacement is technically challenging and although a revision procedure may be desirable, a large amount of bone loss or infection may preclude this. Arthrodesis can be difficult to achieve and is usually associated with considerable shortening of the limb. We describe a technique for restoring talar height using an allograft from the femoral head compressed by an intramedullary nail. Three patients with aseptic loosening were treated successfully by this method with excellent symptomatic relief at a mean follow-up of 32 months (13 to 50).

An aid to femoral nail removal.

We describe a novel technique to aid the removal of a proximally inserted femoral nail by using a guide wire and the starter reamer. By reaming through the scar tissue, a cylindrical track is created and the threaded top end of the nail is exposed. The soft tissue dissection is therefore limited to the absolute minimum with no further damage to the hip abductors.

Irrigation and suction technique to ensure reliable cement penetration for total knee arthroplasty.

We describe a new technique to enhance the preparation of the cancellous bone surfaces in total knee arthroplasty using bone suction and pressure lavage irrigation. This technique provides dry bone surfaces on which to cement (which is particularly valuable if a tourniquet is not used) and improves significantly the penetration of cement into the tibial plateau as assessed on plain postoperative radiographs. We review the results of this new technique by analyzing depths of cement penetration on postoperative radiographs to assess whether this technique offers improvements in cement penetration and bone surface preparation. This technique offers a simple, quick, and reliable method of ensuring reliable cement penetration into the bony trabeculae during cemented total knee arthroplasty.