Intercondylar distal femoral fracture. An unreported complication of posterior-stabilized total knee arthroplasty

Deep-dish congruent tibial component use in total knee arthroplasty: a randomized prospective study

One hundred seventy-six patients with osteoarthritis of the knee were randomized prospectively into two groups. In both groups the posterior cruciate ligament was released from its femoral attachment. In one group a posterior stabilized tibial component was used whereas in the other group a deep-dish tibial polyethylene component was inserted (Genesis II). The surgical and perioperative technique was identical in both groups and all the implants were cemented to their respective bones. Patients began range of motion exercises within the first few hours after surgery and were allowed weightbearing to tolerance beginning on the first postoperative day. At followup there was no statistical difference in the mean range of flexion (approximately 116 degrees), ability to ascend and descend stairs in a bipedal manner (80%), pain scores, knee scores (94 points), stability, or the lack of anterior knee pain. Postoperative implant alignment in the sagittal and coronal planes and on Merchant skyline views was excellent in both groups. There was only one lateral release required and that was in one patient who received a deep-dish component. Using deep-dish implant obviates the need to resect intercondylar femoral bone, decreasing the potential for fracture and maximizing bone volume should revision be necessary in the future.

Posterior stabilization in total knee arthroplasty with use of an ultracongruent polyethylene insert

Fifty-three primary and 47 revision posterior cruciate ligament (PCL)-substituting total knee arthroplasties (TKAs) using a highly conforming (ultracongruent) polyethylene insert were retrospectively reviewed over a 48- to 106-month (mean, 60+/-11 months) follow-up period. These 100 knees were age and sex matched with another 100 TKAs performed using a PCL-sparing design. The ultracongruent design has an anterior buildup of 12.5 mm and a more conforming articular surface to match better the radius of the femoral component. In primary and revision TKAs, the average Hospital for Special Surgery knee score (P = .3) and range of motion (P = .43) were similar between the PCL-sparing and ultracongruent groups. In primary and revision TKAs, there were no revisions resulting from instability for patients receiving an ultracongruent insert versus 5 knees in the PCL-sparing control group secondary to subsequent postoperative anteroposterior instability and PCL insufficiency.

Epidemiology: hip and knee

This article reviews the epidemiologic features of periprosthetic fractures around total hip arthroplasty and total knee arthroplasty according to the site of fracture occurrence. The frequency and cause of intraoperative and postoperative periprosthetic fractures vary by anatomic site. For each anatomic site, unique risk factors, some demographic and some technical, appear to be related to risk of fracture. For several anatomic sites, excellent articles that collate large numbers of series are available to the reader to provide aggregate information concerning the epidemiology of these fractures.

The prevention of periprosthetic fractures in total hip and knee arthroplasty

Periprosthetic fractures in total hip and total knee arthroplasty lead to considerable morbidity in terms of component fixation, bone loss, and subsequent function. The management of these fractures is technically demanding and may result in suboptimal fixation owing to poor bone stock. The prevention, early recognition, and appropriate management of such fractures are therefore critical. The pathogenesis of periprosthetic factors is multifactorial. There are a number of intrinsic patient influences such as bone stock, biomechanics, and compliance. There are also a host of extrinsic factors over which the surgeon has more control. The prevention of periprosthetic fractures requires careful preoperative planning and templating, the availability of the necessary expertise and equipment, and knowledge of the potential pitfalls so that these can be avoided both intraoperatively and in follow-up.