Patella in total knee arthroplasty.

The patella is a reliable guide to the success or failure of a total knee replacement. Patients who do not experience peripatellar symptoms or a patellar complication usually have a successful result. Conversely, peripatellar symptoms or complications usually reflect an underlying problem with surgical technique, component designs, or both.

The effect of osteogenic protein-1 on the healing of segmental bone defects treated with autograft or allograft bone.

Background: Large amounts of bone graft are frequently used to elicit the healing of bone defects resulting from reconstructive procedures. Autograft and allograft bone are often used, but each has its limitations. Bone morphogenetic proteins (BMPs) improve the healing of segmental bone defects treated with autograft or allograft.

The use of modularity in revision total hip replacement.

A study was undertaken to establish the pattern of components revised in recent years during total hip revision to establish how often a modular feature of a retained component was used. All total hip revisions performed by the total joint service of the University Hospital between 1991 and 1995 were reviewed. Revisions involving a surface replacement, endoprosthesis, bipolar stem, or infection were excluded because retention of components is not an option in these cases.

Failed cementless total knee arthroplasty presenting as osteolysis of the fibular head.

Large osteolytic lesions can occur adjacent to cementless total knee arthroplasty components. This occurrence frequently is related to suboptimal design features leading to the generation of metal or polyethylene wear debris. Occasionally, such lesions can mimic a bone tumor.

The Otto Aufranc Award. Strut allograft healing to the femur with recombinant human osteogenic protein-1.

Allograft struts are used to reinforce the deficient proximal femur in hip arthroplasty or for fixation of a periprosthetic fracture. Although the use of strut grafts wired or cabled to the proximal femur generally has been successful, the time for healing is slow. The purpose of the current study was to determine whether cortical strut graft healing to the femur could be enhanced by the addition of recombinant human osteogenic protein-1.

Early failure of modern cemented stems.

In the late 1970s, improved cement technique was introduced in an attempt to address the problem of early cemented stem loosening. Subsequently, numerous centers reported stem survival rates of >95% beyond 10 years. Long-term cemented stem fixation was believed widely to be consistently obtainable in most patients.

Patient satisfaction and outcome after septic versus aseptic revision total knee arthroplasty.

A consecutive series of revision total knee arthroplasties performed at 3 university-affiliated centers by 3 surgeons was prospectively studied. The same implant was used in all cases. The evaluation included a Knee Society clinical score (KSCS); SF-36; satisfaction survey; and radiographs preoperatively, at 6 and 12 months postoperatively, and annually thereafter.

The use of a modular rotating hinge component in salvage revision total knee arthroplasty.

Revision total knee arthroplasty (TKA) using a second-generation modular rotating hinge design was performed on 16 knees in 15 patients over a 5-year period. Follow-up of 2 to 6 years (mean, 51 months) was obtained in 14 knees in 13 patients. Indications for revision were aseptic loosening of a hinged prosthesis (8 knees), loosening and bone loss associated with chronic extensor mechanism disruption (2 knees), component instability with chronic medial collateral ligament disruption (3 knees), and comminuted distal femur fracture (1 knee).

Proximal tibia--extensor mechanism composite allograft for revision TKA with chronic patellar tendon rupture.

Rupture of the patellar tendon following TKA is fortunately an uncommon complication with an incidence of 0.2-4% (Abril et al. 1995).

Patients' perception of pain after total hip arthroplasty.

A study was undertaken to determine the frequency with which patients had pain that they attributed to their hip after total hip arthroplasty. Pain drawings were used to allow patients to localize the area of their symptoms, and the degree of pain was quantified with visual analog scales. Complete clinical and radiographic data were collected on all patients so that the occurrence of pain could be correlated with a number of parameters previously reported to affect the incidence of pain, including age, sex, activity level, length of follow-up, stem size, bone type (Dorr index), and type of stem fixation (proximally coated, fully coated, or cemented).

The results of retaining a well-fixed patellar component in revision total knee arthroplasty.

The results of revision total knee arthroplasty (TKA) in which a well-fixed patellar component was left in place (retained) were compared with those in which the patellar component was revised to a cemented all-polyethylene component. The patella was retained in 34 cases, 12 of which were metal-backed, and was revised in 39 cases. Data collected on all patients included a Knee Society clinical and radiographic score, SF36, a patellofemoral questionnaire, and a satisfaction survey.

Patellar resurfacing in total knee arthroplasty.

Whether or not to resurface the patella when performing a primary total knee arthroplasty remains an open question. A number of recent studies have added new information relevant to this controversy. Anatomic studies show that there is normally substantial variability in the anatomy of the trochlear groove.

Core decompression and conservative treatment for avascular necrosis of the femoral head: a meta-analysis.

Core decompression for avascular necrosis (AVN) of the femoral head continues to be a controversial procedure. Meta-analysis techniques were employed to identify 22 studies with a single surgical core decompression technique. A similar procedure identified eight studies that treated patients conservatively.

The effect of weight-bearing on the radiographic measurement of the position of the femoral head after total hip arthroplasty.

Background: In most radiographic studies of polyethylene wear, investigators have used routine annual radiographs made with the patient in the supine position in order to measure penetration by the femoral head into the polyethylene liner. However, researchers have begun to question the effect of weight-bearing on the position of the head within the acetabular cup and, consequently, the effect of weight-bearing on measurements of penetration by the head. The purpose of the current study was to determine the effect of weight-bearing on the two-dimensional radiographic position of the femoral head within the acetabular cup.

Cost analysis of revision total hip arthroplasty. A 5-year followup study.

A stratified, unselected sample of 30 patients who underwent revision total hip arthroplasty between 1990 and 1992 for whom complete clinical and financial data were available was studied. Clinical data included age, gender, diagnosis, length of stay, operative time and blood loss. Financial data included cost of implants, bone graft and accessories, hospital charge, and surgeon reimbursement.

Pain at the end of the stem after revision total knee arthroplasty.

A consecutive series of patients undergoing revision total knee arthroplasty was studied prospectively. Clinical and radiographic assessment was performed preoperatively, 6 and 12 months postoperatively, and annually thereafter. Evaluation consisted of a Knee Society clinical score and assessment of patient satisfaction.

Joint line restoration after revision total knee arthroplasty.

In 99 patients, 107 knee replacements were revised in two centers by two surgeons using a single revision total knee arthroplasty system. A retrospective radiographic review of joint line position before and after revision total knee arthroplasty was made, and compared with the joint line position before primary knee arthroplasty. Prospectively collected Knee Society Clinical Rating Scores were correlated with radiographic findings.