Background

As hallux valgus (HV) worsens clinical and radiological signs of arthritis develop in metatarsophalangeal joint due to incongruity of joint surfaces. The purpose of this prospective study was to determine if intraoperative mapping of articular erosion of the first metatarsal head, base of the proximal phalanx, and tibial and fibular sesamoids can be correlated to clinical and/or radiographic parameters used during the preoperative assessment of the HV deformity

The Oxford Knee Score (OKS) is a valid and reliable self-administered patient questionnaire that enables assessment of the outcome following total knee replacement (TKR). There is as yet no literature on the behavioral trends of the OKS over time. Our aim is to present a retrospective audit of the OKS for patients who have undergone TKR during the past ten years.

We retrospectively analysed 3276 OKS of patients who had a primary TKR and had been registered as part of a multi-surgeon, outcome-monitoring program at St. Helier hospital. The OKS was gathered pre-operatively and post-operatively by means of postal questionnaires at annual intervals. Patients were grouped as per their age at operation into four groups: 60, 61-70, 71- 80 and >80. A cross-sectional analysis of OKS at different time points was performed.

The numbers of OKS available for analysis were 504 pre-operatively, 589 at one-year, 512 at two-year and gradually decreasing numbers with 87 knees ten-year post-operatively. There was as expected a significant decrease (improvement) of the OKS between pre-operative and one-year post-operative period and then reached a plateau. Beyond eight years, there is a gradual rise in the score (deterioration). The younger patients (60) showed a significant increase in their average OKS between one and five-years post-operatively. However beyond five years, they followed the trend of their older counterparts. When the twelve questions in the OKS were analysed, certain components revealed greater improvement (e.g. description of knee pain and limping) than others (e.g. night pain).

The OKS is seen to plateau a year after TKR. According to the OKS the outcome of the TKR is not as good in the younger age group as compared to the older age group. Further investigation is required to ascertain the cause of this observed difference.

The performance of total knee arthroplasty in deeply flexed postures is of increasing concern as the procedure is performed on younger, more physically active and more culturally diverse populations. Several implant design factors, including tibiofemoral conformity, tibial slope and posterior condylar geometry have been shown directly to affect deep flexion performance.

The goal of this study was to evaluate the performance of a fixed-bearing, asymmetric, medial rotation arthroplasty design during kneeling activities.

Thirteen study participants (15 knees) with primary total knee arthroplasty (Medial Rotation Knee, Finsbury, Surrey, UK) were observed while doing a step activity and kneeling on a padded bench from 90° to maximum comfortable flexion using lateral fluoroscopy. Subjects averaged 74 years of age and nine were female. Subjects were an average of 17 months post-operative, and scored 94 points on the International Knee Score and 99 on the Functional Score. Digitised fluoroscopic images were corrected for geometric distortion and 3D models of the implant components were registered to determine the 3D position and orientation of the implants in each image.

During the step activity, the medial and the lateral femoral contact point stayed fairly constant with no axial rotation from 0 to 100° of flexion. At maximum kneeling flexion, the knees exhibited 119° of implant flexion (101°-139°), 7° (-7° to 17°) tibial internal rotation, and the lateral condyle translated backwards by 11 mm.

Patients with medial rotation knee arthroplasty exhibited medial pivot action with no paradoxical translation. The knees exhibited excellent kneeling flexion and posterior translation of the femur with respect to the tibia. The axial rotation in MRK was within the range of normal knee kinematics from -10 to 120 (perhaps 140).