Modern total knee arthroplasty (TKA) prostheses are designed to restore near normal kinematics including high flexion. Kneeling is a high flexion, kinematically demanding activity after TKA. The debate about design choice has not yet been informed by six-degrees-of-freedom in vivo kinematics. This prospective randomized clinical trial compared kneeling kinematics in three TKA designs. In total, 68 patients were randomized to either a posterior stabilized (PS-FB), cruciate-retaining (CR-FB), or rotating platform (CR-RP) design. Of these patients, 64 completed a minimum one year follow-up. Patients completed full-flexion kneeling while being imaged using single-plane fluoroscopy. Kinematics were calculated by registering the 3D implant models onto 2D-dynamic fluoroscopic images and exported for analysis.Aims
Methods
We have investigated iatrogenic popliteal artery
injuries (PAI) during non arthroplasty knee surgery regarding mechanism
of injury, treatment and outcomes, and to identify successful strategies
when injury occurs. In all, 21 iatrogenic popliteal artery injuries in 21 patients
during knee surgery other than knee arthroplasty were identified
from the Swedish Vascular Registry (Swedvasc) between 1987 and 2011.
Prospective registry data were supplemented with case-records, including
long-term follow-up. In total, 13 patients suffered PAI during elective surgery
and eight during urgent surgery such as fracture fixation or tumour
resection. Nine injuries were detected intra-operatively, five within
12 to 48 hours and seven >
48 hours post-operatively (two days to
23 years). There were 19 open vascular and two endovascular surgical repairs.
Two patients died within six months of surgery. One patient required
amputation. Only six patients had a complete recovery of whom had
the vascular injury detected at time of injury and repaired by a
vascular surgeon. Patients sustaining vascular injury during elective
procedures are more likely to litigate (p = 0.029). We conclude that outcomes are poorer when there is a delay of
diagnosis and treatment, and that orthopaedic surgeons should develop
strategies to detect PAI early and ensure rapid access to vascular
surgical support. Cite this article: