Representative images from MMP-13 staining of the native, native/immobilized, and repaired/immobilized groups at two and four weeks (×20). A, Native tendon at two weeks. B, Native/immobilized tendon at two weeks. C, Repaired/immobilized tendon at two weeks. D, Native tendon at four weeks. E, Native/immobilized tendon at four weeks. F, Repaired/immobilized tendon at four weeks.

Anteroposterior standing radiograph of a knee that had late failure due to polyethylene wear nineteen years after medial unicompartmental knee arthroplasty.

Schematic block diagram illustrating the ACL Clinical Pathway with perioperative steps for patients and guidelines for providers. NMCSD = Naval Medical Center San Diego, ACLR = anterior cruciate ligament reconstruction, ASA = American Society of Anesthesiologists, d/c = discharge, OR = operating room, PT = physical therapy, rehab = rehabilitation, PACU = post-anesthesia care unit, POD = postoperative day, s/p = status post, H&P = history and physical, Rx = prescription, and abx = antibiotics.

Flowchart showing the identification of the study cohort. OA = osteoarthritis.

To determine the posterior tibial slope, a line is drawn down the longitudinal axis of the tibia on a true lateral radiograph. Then a line is drawn from the peak anterior and posterior points on the medial tibial plateau. The posterior tibial slope is defined as the angle between the line joining the tibial plateau and the line perpendicular to the longitudinal axis.

Patient flowchart.

Functional and anatomic bundles of the ACL. The functional and anatomic bundles of the ACL are illustrated with the medial femoral condyle removed in knee extension (Fig. 1-A) and in knee flexion (Fig. 1-B). As the knee flexes, the anteromedial (AM) bundle becomes taut as the origin “rolls over” the posterolateral (PL) bundle origin. (Reproduced from: Chhabra A, Starman JS, Ferretti M, Vidal AF, Zantop T, Fu FH. Anatomic, radiographic, biomechanical, and kinematic evaluation of the anterior cruciate ligament and its two functional bundles. J Bone Joint Surg Am. 2006 Dec;88 Suppl 4:2-10.)

Estimated prevalence of total knee replacement (TKR) in the U.S. by age and sex. Each bar represents the percent of the population with total knee replacement, stratified by age group (increasing from left to right) and sex (blue for male and orange for female). The error bars around each prevalence estimate represent 95% confidence intervals.

Flow diagram of patient recruitment and loss to follow-up. TKA = total knee arthroplasty.

Anteroposterior radiograph of a hip with Vancouver type-A periprosthetic fracture of the greater trochanter related to osteolysis.