1. The Effects of Severe Femoral Bone Loss on the Flexion Extension Joint Space in Revision Total Knee Arthroplasty: A Cadaveric Analysis and Clinical Consequences
- Author
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Kenneth A. Krackow and William M. Mihalko
- Subjects
musculoskeletal diseases ,Knee Joint ,Medial Collateral Ligament, Knee ,Knee Injuries ,Osteoarthritis ,Arthritis, Rheumatoid ,Joint capsule ,Cadaver ,medicine ,Humans ,Orthopedics and Sports Medicine ,Femur ,Tibia ,Range of Motion, Articular ,Arthroplasty, Replacement, Knee ,Aged ,Retrospective Studies ,Aged, 80 and over ,Flexion contracture ,Medial collateral ligament ,business.industry ,Anatomy ,Middle Aged ,Osteoarthritis, Knee ,musculoskeletal system ,medicine.disease ,Treatment Outcome ,medicine.anatomical_structure ,Ligament ,Osteoporosis ,Female ,Surgery ,business ,Joint Capsule - Abstract
Five revision total knee arthroplasties (TKAs) involving severe femoral bone loss were performed in 1 994. Each had sufficiently severe femoral bone loss in which collateral ligament origins and posterior capsular attachments were violated. A paradoxical phenomenon was observed in each case. Unlike primary TKAs, in which larger distal femoral bone resection leads to laxity of the knee joint in extension, these cases with severe distal femora! bone loss, after initial component selection, developed the opposite situation, a flexion contracture. It was hypothesized that femoral bone loss involving collateral ligament origins would permit distraction of the tibia below the femur with the knee held in flexion, but when the knee was brought to full extension, intact posterior structures would maintain a normal tibia! position. To investigate this hypothesis, six fresh-frozen cadaveric lower limbs were tested in full extension and 45° and 90° of flexion after release of the femoral attachments of the collateral ligaments and the posterior capsule from the femur. Joint space changes were measured via a motion tracking device. Results showed that with loss of collateral attachments, 17.2±8.9 mm of joint space is created in 90° of flexion, whereas the joint space in full extension is conserved (1.5±1.7 mm). With additional loss of the posterior capsule, the joint space at 90° of flexion increased to 26.2±6.1 mm, with minimal changes in the extension gap (3.4±0.8 mm). Distal femoral bone loss was associated with an increase in the flexion gap compared to the extension gap.
- Published
- 2001