Article

The anatomy of the posterior aspect of the knee - An Anatomic study

Department of Orthopaedic Surgery, University of Minnesota, 2450 Riverside Avenue, R200, Minneapolis, MN 55454, USA.
The Journal of Bone and Joint Surgery (Impact Factor: 4.31). 04/2007; 89(4):758-64. DOI: 10.2106/JBJS.F.00120
Source: PubMed

ABSTRACT The orthopaedic literature contains relatively little quantitative information regarding the anatomy of the posterior aspect of the knee. The purpose of the present study was to provide a detailed description of, and to propose a standard nomenclature for, the anatomy of the posterior aspect of the knee.
Detailed dissection of twenty nonpaired, fresh-frozen knees was performed. Posterior knee structures were measured according to length, width, and/or distance to reproducible osseous landmarks.
The semimembranosus tendon had eight attachments distal to the main common tendon. The main components were a lateral expansion to the oblique popliteal ligament; a direct arm, which attached to the tibia; and an anterior arm. The oblique popliteal ligament, the largest posterior knee structure, formed a broad fascial sheath over the posterior aspect of the knee and measured 48.0 mm in length and 9.5 mm wide at its medial origin and 16.4 mm wide at its lateral attachment. It had two lateral attachments, one to the meniscofemoral portion of the posterolateral joint capsule and one to the tibia, along the lateral border of the posterior cruciate ligament facet. The semimembranosus also had a distal tibial expansion, which formed a posterior fascial layer over the popliteus muscle. A thickening of the posterior joint capsule, the proximal popliteus capsular expansion, which in this study averaged 40.5 mm in length, connected the posteromedial knee capsule at its attachment at the intercondylar notch to the medial border of the popliteus musculotendinous junction. The plantaris muscle, popliteofibular ligament, fabellofibular ligament, and semimembranosus bursa were present in all specimens.
The anatomy of the posterior aspect of the knee is quite complex. This study provides information that can lead to further biomechanical, radiographic imaging, and clinical studies of the importance of these posterior knee structures.

1 Follower
 · 
159 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Patellofemoral arthroplasties are desirable when treating isolated patellofemoral osteoarthritis, due to preservation of the tibiofemoral joint. Since few studies report on new commercial patellofemoral prosthesis biomechanics, a musculoskeletal model enabling analysis of subject-specific knee biomechanics was used to compare four patellofemoral replacement systems (A, B, C, and D) to one another. The prostheses were implanted according to manufacturer guidelines, after which the knee flexed and extended under active muscle loading. An increased patellotrochlear index enabled early patella-trochlear groove engagement. The resurfaced patellae were stable in mediolateral shift and anteroposterior displacement, but only Prosthesis A and D provided a smooth transition between the distal prosthesis border and femoral cartilage. A reduction in the anteroposterior condylar distance displaced the patella posteriorly, resulting in reduced peri-patellar soft tissue tension but an increased patella tendon–quadriceps tendon ratio. The tibial tubercle–trochlear groove distance became pathologic in all replacements. The patella will be stable irrespective of the prosthesis used, but Prosthesis A and D seem to provide a better fit to the trochlear groove anatomy. The increased tibial tubercle–trochlear groove distance emphasizes the importance of extensor alignment in combination with the placement of the prosthesis: an increased Q-angle might lead to excessive lateral wear on the patella button. The extensor mechanism load will increase post-surgery based on the rise in the patella tendon–quadriceps tendon ratio which points to a reduced moment arm. This work provides insight into the dynamic biomechanical function and the design of current commercial patellofemoral replacement systems.
    Journal of Mechanics in Medicine and Biology 12/2012; 12(05). DOI:10.1142/S0219519412500868 · 0.80 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Musculoskeletal modeling has found wide application in joint biomechanics investigations. This technique has been improved by incorporating subject-specific skeletal elements and passive patellofemoral stabilizers in a dynamic analysis. After trochlear engagement, the volunteers' patellae displaced laterally, whereas tilt was subject specific. Comparison of the tilt and mediolateral position values to in vivo MRI values at 30° knee flexion showed a mean accuracy of 84.4% and 96.9%, respectively. Medial patellofemoral ligament tension decreased with knee flexion, while the patellar tendon–quadriceps tendon ratio ranged from 0.4 to 1.2. The patellofemoral contact load–quadriceps tendon load ratio ranged from 0.7 to 1.3, whereas the mediolateral load component–resultant load ratio ranged from 0 to 0.4. Three validated subject-specific musculoskeletal models facilitated the analysis of patellofemoral biomechanics: Subject-specific patella tracking and passive stabilizer response was analyzed as a function of dynamic knee flexion.
    Journal of Mechanics in Medicine and Biology 04/2012; 11(05). DOI:10.1142/S0219519411004332 · 0.80 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The goal of this study was to present a 2- to 5-year prospective follow-up of an anatomical posterolateral corner reconstruction in a series of 16 patients with symptomatic instability and pain complaints of the knee.