Lipohemarthrosis of the Hip Joint in Apparently Isolated Greater Trochanter Fractures.

Backgroud: Lipohemarthrosis in the hip joint, a critical indicator for detecting occult femoral neck or acetabular fractures, has not been reported in cases of isolated greater trochanter (IGT) fractures. This study retrospectively reviewed 3-dimensional computed tomography (3D-CT) images of what appeared to be IGT fractures to find out the frequency of lipohemarthrosis and its implication for the necessity of internal fixation.

Methods: From October 2004 to December 2019, 90 cases of suspected IGT fractures were evaluated using 3D-CT. After excluding 6 cases due to inadequate follow-up and 8 cases with poor imaging quality caused by metallic implants, 76 cases were included in the final analysis. The cohort consisted of 48 women and 28 men, with a mean age of 77 years (range, 39-97 years). The 3D-CT images were meticulously reviewed to identify lipohemarthrosis in the affected hip joints. Additionally, magnetic resonance (MR) images were available for 13 cases.

Results: Sixty-three cases were IGT fractures; no cortical disruption was detected in the intertrochanteric area on CT images. Of these, 56 cases were successfully treated conservatively. Lipohemarthrosis was detected in 5 cases (7.9%), of which 2 were successfully managed with conservative treatment. The remaining 13 cases were classified as incomplete intertrochanteric fractures, with anterior cortical disruption identified in the intertrochanteric area on CT images. Lipohemarthrosis was observed in 3 of these cases (21.3%). In all cases evaluated with MR imaging (10 IGT fractures and 3 incomplete intertrochanteric fractures), varying degrees of intramedullary intertrochanteric extension were observed. Among these, lipohemarthrosis was detected in only 2 cases of IGT fracture, where the intramedullary extension did not cross the midline on mid-coronal images. One case was surgically fixed, but the other case was treated conservatively with success. Notably, 4 cases with intertrochanteric extension crossing the midline did not exhibit lipohemarthrosis.

Conclusions: Lipohemarthrosis was more frequently observed in incomplete intertrochanteric fractures than in IGT fractures. However, the presence of lipohemarthrosis alone should not be regarded as an indication for internal fixation.