To what extent does leg length discrepancy impair motor activity in patients after total hip arthroplasty?

Abstract

The aim of this study was to evaluate the effects of limb lengthening up to 20 mm after THA on symmetry of hip kinematics and kinetics during common activities of daily living. Twenty patients (age range 49-80 years) operated on with Link Lubinus II THA, with lateral access and a mean follow-up of 16 months, were assessed by gait analysis during level walking, stair ascending and descending. The time-distance, hip kinetics and kinematics values were statistically compared between the operated side and the non-operated side in order to assess symmetry. The 12-item Questionnaire was used to assess satisfaction and personal perception of limb lengthening. Mean value of limb lengthening after THA was 11 mm (SD 6). Minor abnormalities were found in the kinematics and kinetics of the operated and non-operated hips during level walking and stair climbing. The score of the questionnaire corresponded to a high level of satisfaction after THA and only two patients complained of limping independent from the amount of discrepancy. From this study we can conclude that a leg length inequality in the range of 1-20 mm does not impair the symmetry of time-distance parameters and of hip kinematics and kinetics during gait and stairs walking. Although objective, gait analysis data did not correspond to patient's perception of discrepancy, which is subjective and irrespective of the amount of lengthening. There is biomechanical evidence that a limb lengthening of up to two centimetres after THA in general does not need to be corrected by means of a contralateral shoe lift. Individual decisions to the contrary need to be justified.

The Influence of Leg Length Discrepancy after Total Hip Arthroplasty on Function and Quality of Life: A Prospective Cohort Study

“…Therefore, the shortening of the operated leg in this study population did not seem to compromise the prosthetic stability. Other studies reported no influence of LLD on the functional outcome after THA [11,12,32]. Accordingly, we conclude that replacement of the diseased painful joint, keeping the leg length as it was before the operation or restoring to the contralateral leg length, with correct prosthetic positioning, is associated with the best WOMAC index and prosthetic stability.…”

“…In the literature, LLD is reported to vary widely among studies e.g. However, the threshold at which an LLD is clinically important is still a matter of debate [12,13]. However, the threshold at which an LLD is clinically important is still a matter of debate [12,13].…”

“…However, the threshold at which an LLD is clinically important is still a matter of debate [12,13]. Benedetti et al [12] showed that LLD in the range of 1-20 mm did not impair the symmetry of time-distance parameters and of hip kinematics and kinetics during gait and stairs walking. O'Brien et al [14] suggested that LLD after THA should be kept to less than 10 mm as healthy people in their study were aware of LLD more than this.…”

“…Perception of LLD after THA is reported in one third of operated patients and affected patients reported lower functional outcome [5]. Unfortunately, most of the above-mentioned studies had limitations such as retrospective design [7,10,12], inadequate sample size [10,12,15], lack of preoperative function and quality of life [11,12,16,17] and heterogenous material where different types of osteoarthritis and even bilateral osteoarthritis mixed and evaluated together [10,16]. Konyves and Bannister [17] found that lengthening after LLD was associated with lower functional outcome up to 12 months postoperatively.…”

Functional Outcome After Successful Internal Fixation Versus Salvage Arthroplasty of Patients With a Femoral Neck Fracture

“…Moreover, although the left-right differences in gait parameters seem small, research in patients after total hip arthroplasty for osteoarthritis has indicated that these subtle difference have clinical relevance. 24 …”