Acute Pelvis & Hip Trauma Imaging Diagnosis Part II | El Paso, TX.

Hip Fractures

• Garden Classification (above) helps with Dx and correct management of patients
• M/C Fx are subcapital (80%)
• Fxs differentiated as intra-capsular (high risk of AVN) & extra-capsular (lower risk of AVN)
• Garden 1: incomplete undisplaced Fx typically impaction with valgus off-set of the head (15-20% AVN) patient able to ambulate
• Garden 2: complete, undisplaced Fx (30% AVN)
• Garden 3: complete, partially <50% displaced
• Garden 4: complete, 100% displaced Fx, pt collapsed with entire LE in ER (below image)
• Most osteoporotic Fx are intracapsular

Complete Displaced Femoral Neck Fracture Clinical Presentation

Imaging: Begins with X-radiography with Most Fxs

• CT scanning may help with further delineation of Fx complexity/displacement and Dx of additional regional Fxs
• MRI can be helpful if x-radiography fails to Dx fx
• X-radiography pitfalls: some undisplaced Garden 1 & 2 Fxs may be missed d/t pre-existing DJD and osteophytes along the femoral head-neck junction that may overly the Fx line
• Fx line is incomplete and too small/subtle especially if the study is read by non-radiologists
• Incomplete Fxs if left untreated will not heal and likely to progress to complete Fxs

• AP hip spot view: note valgus deformity of the head (above yellow arrow) with a small/subtle line of sclerosis in the sub-capital region representing Garden 1 Fx. MRI may help with Dx of subtle radiographic Fxs. If MRI contraindicated, Tc 99 radionuclide bone scan may help demonstrate high uptake of the radiopharmaceutical in Fx (below image)

Above – Tc99 Radionuclide Bone Scan Reveals Left Subcapital Femoral Neck Fx

• Garden 2 complete undisplaced (above green arrows) Fx

• AP hip: Garden 3 complete partially displaced Fx (above the first image)
• AP pelvis: complete displaced Garden 4 Fx (above the second image)
• Clinical pearls: in some cases of Garden 4 Fx, DDx may be difficult to differentiate from OSP vs. pathologic fx d/t to bone Mets of Multiple myeloma (MM)
• Management: depends on patients age and activity level
• Garden 3 & 4  require total hip arthroplasty in patients <85-y.o.
• Garden 1 & 2 may be treated with closed reduction of fx and open capsule and 3-cannulated fixating screws
• Pre-existing DJD may require total arthroplasty
• Occasionally observation may be performed on patients who are not active and significant risks of surgery and depends on surgical centers

• m/c Rx of Garden 1 & 2 undisplaced Fx with 3-screws. Screws proximity depends on the bone quality and Fx type

• THA aka hip replacement: cemented THA with bone cement (above the first image) vs. non-cemented (biologic) that is used mostly in younger patients
• 2-types: metal on metal vs. metal on polyethylene
• The femoral angle of the prosthesis should have slight valgus but never >140 degrees
• The non-cemented component uses porous metal allowing the bone to integrate sometimes coating in bone cement from osteoconduction
• THA has good outcome and prognosis
• Occasionally cement failure, fractures, and infections may complicate this procedure 

Supplemental Reading

• https://www.aafp.org/afp/2014/0615/p945.html
• https://emedicine.medscape.com/article/87043-overview
• https://radiopaedia.org/articles/proximal-femoral-fractures-summary

Acute Pelvis & Hip Trauma