Is Normal Knee Biomechanics Reproduced by Modern Total Knee Arthroplasty Designs? The Role of Fluoroscopy

Pier Francesco Indelli*

Is Normal Knee Biomechanics Reproduced by Modern Total Knee Arthroplasty Designs? The Role of Fluoroscopy

Knee kinematics has been studied since the seventeen century
with increasing enthusiasm: recent studies showed that femoral rollback,
femoral external rotation and tibia internal
rotation are all required for normal daily living.

Total Knee Arthroplasty (TKA) is a successful procedure in treating subjects with severe
knee osteoarthritis: unfortunately, knee joint kinematic after TKA can differ substantially
when compared to the kinematic of the normal knee.

Numerous kinematic studies using standing and mobile fluoroscopy, gait analysis technologies
and simple in vitro techniques have extensively evaluated those differences. In this review
article, the authors reviewed the contribution of different fluoroscopic studies in understanding
the biomechanical differences between the native and the replaced knee.

Total Knee Arthroplasty (TKA) represents a very successful procedure in the treatment
of patients affected by severe end-stage tricompartimental knee osteoarthritis.
Many patients return to normal daily living activities,
including low-impact recreational activities like
biking, golfing, swimming and trekking.

Unfortunately, TKA patients still experience substantial functional
impairment compared with their age- and gender-matched peers, especially
when doing biomechanically demanding activities.

Patient satisfaction after TKA reflects these differences: despite recent advances
in surgical techniques, implant designs, and patients education, the satisfaction
rate after primary TKA between the last decade of the twentieth century and
the first decade of the twenty-first century increased only by 3%,
leaving 15% of the patients not fully satisfied.

Numerous kinematic studies using static and dynamic fluoroscopy,6,8,9 gait analysis,10
and in vitro techniques11,12 have revealed profound differences between normal knee motion
and TKA kinematics. Theoretically, these differences might play a major role in understanding
the still high “un-satisfaction” rate among patients following primary TKA.

Osteol Rheumatol Open J. 2016; 1(1): 6-9. doi: 10.17140/ORHOJ-1-103