The extensor mechanism provides active knee joint extension and stability of the patellofemoral joint. Rupture of the quadriceps tendon, although uncommon, is therefore associated with impairment in knee joint stability and, thus, requires surgical repair. Although various techniques provide excellent clinical outcomes for acute rupture, treatment of chronic rupture remains clinically challenging. We describe our modified technique for quadriceps tendon repair using a semitendinosus tendon autograft, with suturing of the quadriceps tendon stump to the patella via transosseous sutures, wherein the use of allograft and anchors is avoided. Our modified Pulvertaft weave technique is simple and reproducible.

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ObjectiveTo make a comparative analysis on three femoropatellar radiographic parameters, between knees with chronic failure of the anterior cruciate ligament (ACL) and normal knees.MethodsThirty volunteer patients with a diagnosis of unilateral isolated chronic ACL injury for more than one year and a normal contralateral knee were selected. Digital radiographs were produced for all the patients, on both knees in absolute lateral view at 30° of flexion, with and without load-bearing on one leg, and in axial view of the patella at 30°. The Caton–Deschamps patellar height index, Merchant patellar congruence angle and Laurin lateral patellar tilt angle were measured on the radiographs obtained from the normal knees and knees with ACL injuries, and comparative analysis was performed between these two groups.ResultsThe patellar height was statistically significantly lower (p < 0.001) in the knees with ACL failure than in the normal knees, both on radiographs without loading and on those with single-foot loading. The Merchant patellar congruence angle was significantly smaller (p < 0.001) in the normal knees and the lateral patellar tilt angle was smaller (p < 0.001) in the knees with ACL failure.ConclusionChronic ACL failure gave rise to a statistically significant change in the femoropatellar radiographic values studied (p < 0.001). Knees with injuries to this ligament presented lower patellar height values, greater tilt and lateral displacement of the patella, in relation to the femoral trochlea, in comparison with the normal contralateral knees.

ObjectiveTo assess the inter- and intraobserver reproducibility of the original version and different descriptions of the Kellgren and Lawrence classification used in epidemiological studies for osteoarthritis of the knee.MethodsThe study included 72 patients with osteoarthritis of the knee. Three medical members of the Brazilian Society of Knee Surgery were invited to evaluate the images. An intra- and interobserver analysis was conducted, with an interval of one month. The intraobserver agreement was analyzed using the weighted Cohen's Kappa coefficient. The interobserver agreement was analyzed using the Krippendorff alpha coefficient (α).ResultsThe intraobserver assessment indicated conflicting results. In the interobserver analysis, the level of agreement was superficial.ConclusionsThe classification of Kellgren and Lawrence and its variants generated a low reproducibility between observers. The intraobserver analysis showed a lack of uniformity in the use of this classification and its variants, even among experienced observers.

Objective Identify the etiology and incidence, as well to assess functional outcomes of patients, undergoing lower limb amputation after failure or complication of total knee arthroplasty. These patients were treated at the Center for Knee Surgery at the National Institute of Traumatology and Orthopedics (INTO), during the period of January 2001 to December 2010. Methods The patients were interviewed and their charts were retrospectively analyzed to evaluate their functional outcome. Results The incidence of amputation due to failure or complication of total knee arthroplasty was 0.41% in 2409 cases. Recurrent deep infection was the cause of amputation in 81% of cases, being Staphylococcus aureus and Pseudomonas aeruginosa the most frequent germs. Vascular complications and periprosthetic fracture associated to metaphyseal bone loss were also causes of amputation. In our study, 44% of amputees patients were using orthesis and 62.5% have had the ability to walk. Conclusion Incidence of 0.41%, being the main cause recurrent infection. The functional outcome is limited, and the fitting achieved in 44% of patients and only 62.5% are ambulatory.

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Debris of polyethylene tibial bearings have been recognized as a major cause for the onset of the cascade of biological events leading to osteolysis and loosening of prosthetic components after total knee arthroplasty. Since then, research has been focused on alternative bearing surfaces in order to minimize the amount and rate of polyethylene wear off and, in doing so, increasing the survivorship rate for knee arthroplasties. One such option is to have a mobile tibial bearing allowing more conformity and rotational self-alignment of the components, improving kinetics and kinematics of the prosthesis. The authors present a resumed but throughout and comprehensive review of the rationale, biomechanics fundamentals, indications, pitfalls, outcomes and complications for the use of mobile tibial bearings in total knee replacement.

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