Microscopic studies of human press fit titanium hip prostheses

Area of Science:

• Orthopedic surgery
• Biomaterials science
• Geriatric medicine

Background:

• Displaced subcapital hip fractures are common in elderly patients.
• Cementless femoral prostheses offer potential advantages for this demographic.

Purpose of the Study:

• To evaluate the microscopic osseointegration of cementless, rectangular cross-section, titanium alloy femoral prostheses in elderly patients with hip fractures.

Main Methods:

• Seven titanium alloy femoral prostheses were implanted in elderly patients (mean age 88 years) for hip fracture treatment.
• Prostheses were retrieved postmortem after an average of 29 months for microscopic evaluation.
• Histological analysis assessed bone-to-implant contact and bone formation.

Main Results:

• All retrieved prostheses showed stable osseointegration with direct bone-to-implant contact.
• Mean microscopic bone-to-implant contact was 28%.
• Evidence of new viable bone formation and remodeling in apposition to the prosthesis was observed.

Conclusions:

• Cementless, rectangular titanium alloy femoral prostheses achieve satisfactory primary stability in elderly patients with hip fractures.
• Secondary stabilization through new bone formation and remodeling indicates successful long-term osseointegration.
• These findings support the use of this type of prosthesis for treating displaced subcapital hip fractures in the elderly.