Frederick F. Buechel

Ten-Year Evaluation of Cementless Buechel-Pappas Meniscal Bearing Total Ankle Replacement

A porous-coated, cementless, congruent-contact, three-piece, meniscal-bearing total ankle replacement was developed and used clinically over a 2- to 10-year period for patients with disabling ankle arthritis. Polished titanium-nitride ceramic-coated Ti6Al4V tibial and talar components with a deep-sulcus trochlear groove and two lateral fixation fins for the talar onlay component were used. The ultra-high-molecular-weight polyethylene (UHMWPe) meniscal bearing congruently conformed to the flat upper tibial component surface and the deep sulcus and cylindrical geometry of the lower talar component surface. Fifty deep-sulcus (Buechel-Pappas™) total ankle replacements were implanted in 49 patients. Diagnoses were 8 osteoarthritis (16%), 7 rheumatoid arthritis (14%), 2 avascular necrosis (4%), and 33 post-traumatic arthritis (66%). Ages ranged from 26 to 71 years (mean 49 years). Clinical results using a strict ankle scoring system demonstrated good/excellent results in 88% of cases. Postoperative ankle motion ranged from 12° to 46° total arc (mean 28°), which was similar to the preoperative motion. Revision for malalignment was necessary in two cases (4%). Mechanical complications included one case of meniscal bearing wear (2%) in a patient with posttraumatic arthritis with component malalignment and one case of talar component subsidence (2%) in a patient with avascular necrosis of the talus. No tibial component loosening was seen. Cumulative survivorship using an end point of revision of any component for any reason was 93.5% at 10 years (confidence interval 61–100%).

Pathologic supracondylar fracture due to osteolytic pseudotumor of knee following cementless total knee replacement

Wear debris of polyethylene, polymethylmethacrylate, and metal have been recognized to be associated with foreign body reactions, osteolysis, and aseptic prosthetic loosening after joint replacement arthroplasty. Further, foreign body reaction due to the presence of extensive wear debris can cause aggressive granulomatous lesions and pathologic fracture. To our knowledge, there has been no previous report of pathologic fracture of the femur due to an agressive pseudotumor. This report describes a case of pathologic supracondylar fracture of the femur 6 years and 5 months after cementless total knee replacement arthroplasty. The fracture occurred through an aggressive expanding soft tissue mass that was a tumorlike lesion secondary to polyethylene wear debris. The lesion was associated with massive osteolysis around the femoral component of the total knee prosthesis.

31 Year Evolution of the Rotating-Platform Total Knee Replacment: Coping With “Spinout” and Wear

Low-contact-stress rotating-platform knee replacements were the original mobile-bearing knees developed by the senior authors in 1978 to improve fixation and minimize wear, however, 1-2 % experienced “spin-out” and wear resulting in the development of a third generation rotating platform (Buechel-Pappas, or B-P) in 1991. The purpose of this study is to evaluate design modifications incorporated into the B-P device based upon clinical outcomes. Clinical results of the initial 310 cementless B-P rotating platform total knee replacements in 257 patients were analyzed using a strict knee scoring scale. Of that group, 259 total knees in 206 patients were followed for 2–18 years (mean: 7.6 years). The titanium alloy metallic implants had a 10 μm thick titanium nitride (TiN) coating on all bearing and fixation surfaces and sintered-bead porous-coating, pore size of 350 microns, on all fixation surfaces. The rotating-platform bearing allowed 45° of internal and external rotation with further rotation limited by a stop pin on the tibial component to block complete rotary subluxation/dislocation of the bearing in the event of significant flexion instability or rotational trauma. The study showed 86.4 % excellent, 12.3 % good, 0.3 % fair, and 1.0 % poor results using a strict knee scoring scale. Complications requiring revision included tibial component loosening in 2 super-obese (BMI >50), osteoarthritic patients (0.6%) and 1 late deep infection (0.3%) in a rheumatoid patient after 3.3 years. There were no cases of bearing wear, subluxation, or dislocation seen. Radiographic analysis, using >2 mm lucency in any implant zone, demonstrated 0 % of radiolucencies around femoral components, 2.6 % around tibial components, and 0 % around patella components. Survivorship, using an end point of revision for wear or component loosening was 99.4 % at the 18-year interval.

New Jersey Low-Contact-Stress Knee Replacement System: 7- to 15-Year Clinical and Survivorship Outcomes

Cemented and cementless New Jersey Low-Contact-Stress (LCS) knee replacements were followed up for 7–15 years and compared with the results at 2–10 years. Primary (P), multiply-operated (MO) and revision (R) results were analyzed clinically, radiographically, and by survivorship analysis to determine the long-term outcome potential and to evaluate failure mechanisms. In the overall cemented group of 149 knee replacements, good to excellent clinical results were seen in 95.5% of P, 90.0% of MO, and 81.3% of the R groups, respectively. Overall survivorship was 96.7% for the P group at the 10-year interval and 86.7% at the 12- to 15-year intervals. In the overall cementless group of 208 knee replacements, good to excellent clinical results were seen in 96.3% of P, 93.8% of MO, and 93.3% of the R groups, respectively. Overall survivorship estimates were 95.1% for the P group at the 10-year interval and remained at 95.1% at the 12-year interval. Cemented and cementless mobile bearing knee replacements offer satisfactory long-term clinical and survivorship outcomes in a wide variety of arthritic pathologies. Cementless implants appear to be slightly superior overall.

Meniscal-Bearing Knee Arthroplasty

Human joint replacements have been developed with the specific bioengineering requirements to provide normal kinematics, maintain fixation and minimize wear. Lowering contact stresses to within the reported medical load limit of 5 MP (22) while allowing kinematically acceptable motion provides a meniscal bearing surface that is resistant to fatigue wear and has demonstrated normal abrasive wear behavior over a 20 year period as seen in both clinical, simulator, and retrieval studies, (17, 18, 27, 33, 44).