My Orthopaedic Surgeon

Isolated fracture of the lateral condyle of the femur or Hoffa fracture is a rare lesion and has been reported to occur with supracondylar fracture of the femur, fracture of the femoral shaft and knee dislocation. We report a rare case of ipsilateral Hoffa fracture and patellar dislocation, which has not been reported before. R. Vaishya, A.P. Singh, I.T. Dar, A.P. Singh, V. Mittal Can J Surg, Vol. 52, No. 1, February 2009 E3

Knee dislocations are uncommon. A knee dislocation is defined as complete displacement of the tibia with respect to the femur, with disruption of 3 or more of the stabilizing ligaments (Girgis, 1975). Small avulsion fractures from the ligaments and capsular insertions may be present.
Synonyms and related keywords: traumatic knee dislocation, complex knee dislocation, knee pain
Green, Shahrdar, Owens & Olmedo 2004

mechanism of injury:
- distinguish between high velocity injuries verus low velocity injuries (as this reflects incidence of vascular and nerve injuries);
- w/ low-velocity knee dislocations occurance of vascular injury is about 5% and nerve injury is about 20%
- ref: Low-velocity knee dislocation. Shelbourne KD, Porter DA, Clingman JA, et al: Orthop Rev 20:995-1004, 1991
- classification: 5 types: described w/ tibia in relation to femur;
- anterior (31%)
- posterior (25%)
- lateral (13%)
- medial ( 3%)
- rotary ( 4% - usually posterolateral) Wheeless' Textbook of Orthopaedics