Total knee arthroplasty (TKA) is known to lead
to a reduction in periprosthetic bone mineral density (BMD). In theory,
this may lead to migration, instability and aseptic loosening of
the prosthetic components. Bisphosphonates inhibit bone resorption
and may reduce this loss in BMD. We hypothesised that treatment
with bisphosphonates and calcium would lead to improved BMD and
clinical outcomes compared with treatment with calcium supplementation
alone following TKA. A total of 26 patients, (nine male and 17 female,
mean age 67 years) were prospectively randomised into two study
groups: alendronate and calcium (bisphosphonate group, n = 14) or calcium
only (control group, n = 12). Dual energy X-ray absorptiometry (DEXA)
measurements were performed post-operatively, and at three months,
six months, one, two, four, and seven years post-operatively. Mean femoral metaphyseal BMD was significantly higher in the
bisphosphonate group compared with controls, up to four years following
surgery in some areas of the femur (p = 0.045). BMD was observed
to increase in the lateral tibial metaphysis in the bisphosphonate
group until seven years (p = 0.002), and was significantly higher than
that observed in the control group throughout (p = 0.024). There
were no significant differences between the groups in the central
femoral metaphyseal, tibial medial metaphyseal or diaphyseal regions
of interest (ROI) of either the femur or tibia. Bisphosphonate treatment after TKA may be of benefit for patients
with poor bone quality. However, further studies with a larger number
of patients are necessary to assess whether this is clinically beneficial. Cite this article:
Between 1987 and 2006 we performed a modified Thompson’s quadricepsplasty on 40 fracture-related stiff knees and followed the patients for a mean of 7.9 years (2 to 11.1). The factors affecting the final gain of movement were investigated. A total of 15 knees required lengthening of the rectus femoris. The mean flexion gain was 70.2° (42.3° to 112.5°). According to Judet’s criteria, the results were excellent in 30 knees, good in seven, and fair in three. The range of movement which was achieved intra-operatively was related to the gain of knee flexion on univariate analysis. Five patients had complications: deep infection in one, recurrent patellar dislocation in one, and rupture of the extensor mechanism in three. This modified technique gives satisfactory results. Achieving maximum knee flexion intra-operatively seems to be the most important factor in enhancing the outcome in patients with stiffness of the knee following fracture.
