We studied the progression of improvement in the range of motion of the
hip after total hip replacement as it was related to time postoperatively.
One hundred and eight hip replacements performed by members of the Stanford
University Division of Orthopaedic Surgery in ninety-two patients were
included in the analysis. The hips had no major postoperative
complications, and the range of motion was examined preoperatively; at six
months, one year, and two years, postoperatively; and at a last follow-up
examination at a minimum of 4.5 years. There was no statistically
significant improvement in the flexion and abduction of the hip after the
one-year follow-up visit, but adduction and internal and external rotation
were improved significantly at the last follow-up (average, 7.5 years). Of
multiple variables that were studied, including those related to the
patient, to the size and design of the prosthesis, and to the orientation
of the total hip components, only the preoperative range of motion of the
hip and a history of previous surgical treatment were major determining
factors in the postoperative improvement of the range of motion.