[Effect of Primary and Revision Total Hip Arthroplasty on Gait Kinematics]. / Vliv primární a revizní totální endoprotézy kycelního kloubu na kinematiku chuze.

PURPOSE OF THE STUDY The number of patients with total hip arthroplasty (THA) has been growing. In addition to traumatic indication, the patients manifest abnormalities in kinematics and kinetics of gait preoperatively. The aim of the study was to assess kinematics of the pelvis and lower limbs during walking in patients with unilateral primary and revision THA. MATERIAL AND METHODS A total of 18 patients (10 females, 8 males) with primary THA (pTHA) as well as 18 patients (9 males, 9 females) with revision THA (rTHA) participated in the study. The control group (CON) comprised 19 healthy subjects (11 females, 8 males). Kinematic data were collected using the optoelectronic motion system Vicon MX. Kinematic parameters were obtained by means of 16 reflective markers placed on the patient's body in correspondence with the Plug-in Gait model. All the patients also underwent a clinical examination (evaluation of the surgery result, patient's satisfaction assessment, Harris score evaluation) and a specific X-ray evaluation of both hips. RESULTS The analysis brought the following results: - non-operated limb (NL) in pTHA vs. rTHA: significantly smaller total range of motion (ROM) in the hip joint (36.4° vs 41.7°) in the sagittal plane, - operated limb (OL) in pTHA vs. rTHA: significantly greater values of maximum knee flexion (14.2° vs. 9.8°) and extension (7.9° vs. 4.0°), - NL in pTHA vs. CON: significantly smaller ROM in the knee (51.0° vs. 57.9°) and hip (36.4° vs. 43.6°) joints in the sagittal plane, - OL in pTHA vs. CON: significantly smaller knee flexion (52.9° vs. 57.6°), hip extension (-0.6° vs. -10.4°), and the total ROM in the knee (51.5° vs. 57.9°) and hip (34.5° vs. 43.6°) joints in the sagittal plane, - NL in rTHA vs. CON: significantly greater pelvis ROM in both the sagittal (5.6° vs. 3.1°) and transverse (12.1° vs. 9.9°) planes, - OL in rTHA vs. CON: significantly smaller total ROM in the knee (48.9° vs. 57.9°) and hip (31.4° vs. 43.6°) joints in the sagittal plane. DISCUSSION After THA surgery, various gait pathologies as well as compensatory mechanisms can develop and chain; therefore, a complex approach to physical therapy in THA patients is needed. The number of significant differences found in kinematic parameters between pTHA and rTHA was low a year after the surgery. Compared to CON, both the THA groups exhibited similar mechanisms causing worsening their gait dynamics. CONCLUSIONS Gait in both the THA groups was characterized by a decreased ROM in the knee and hip joints in the sagittal plane, compensated by increased pelvic anteversion. Approximately one year after THA surgery, the NL is still noticeably dominant in gait. The changes in lower limb mechanics after revision THA persist even after a considerable time since the surgery. Key words: primary total hip arthroplasty, revision total hip arthroplasty, gait, range of motion, pelvic kinematics, biomechanics.

[Influence of Anterior Cruciate Ligament Reconstruction on Gait Kinematics]. / Vliv rekonstrukce predního zkrízeného vazu na kinematiku chuze.

INTRODUCTION The anterior cruciate ligament (ACL) reconstruction is a tried and tested method in treating knee joint instability which brings valuable results in an acceptable time frame. In the long-term follow-up, however, a higher risk of knee osteoarthritis development is described. One of the possible reasons is considered to be the abnormal kinematics of the operated knee. The purpose of our study was to determine the degree to which the ACL reconstruction helps restore the correct gait cycle compared to the healthy limb. MATERIAL AND METHODS The study included patients after the ACL reconstruction performed in the period from 1 January 2016 to 31 March 2018. With the use of strict criteria, 11 patients were selected for kinematic analysis, who underwent examinations in a gait laboratory and were also evaluated using the Tegner and Lysholm rating systems and the IKDC (International Knee Documentation Committee) knee score, namely preoperatively and at 6 and 12 months postoperatively. The kinematic assessment of gait was carried out using the Vicon MX system with the placement of reflexive markers in line with the Plug-In Gait model. RESULTS The clinical outcomes (namely the score according to Tegner, Lysholm as well as the IKDC) during the first year postoperatively showed a major improvement in knee function and the achievement of the pre-injury activity level. The kinematic analysis revealed lower knee extension at the stance phase and lower overall range of motion of the limb with the injured ACL compared to the healthy limb. The follow-up evaluation at 6 and 12 months postoperatively showed a persisting between-limbs difference in knee extension, whereas the range of motion gradually improved during the year. CONCLUSIONS Although our study confirmed that the ACL reconstruction is an efficient method to treat knee joint instability, it also indicated that even at one year after the ACL reconstruction, the kinematics of the operated knee was not fully restored to the level of the heathy knee. The persisting limb-difference in gait kinematics could contribute to the gradual development of degenerative changes in the operated knee joint. Key words: anterior cruciate ligament deficiency, anterior cruciate ligament reconstruction, knee kinematics during gait, knee osteoarthritis.