Clinical and functional outcome of the Thrust Plate Prosthesis: short- and medium-term results.
OBJECTIVE
The purpose of this study was to objectively assess the functional outcome after implantation of a Thrust Plate Prosthesis.


METHODS
This retrospective study compared the gait patterns of 33 patients to a control group.


BACKGROUND
Few studies have been published about this type of prosthesis describing clinical and radiographic outcome. Even though the evaluation of the functional outcome is a commonly accepted way to measure the success of an implant it has not been reported in previous studies.


METHODS
Beside clinical (SF-36, and Harris Hip Score) and radiographic evaluation subjects were examined by three dimensional gait analysis and surface electromyography from seven leg and trunk muscles bilaterally.


RESULTS
The average Harris Hip Score was 85.7 points, and the SF-36 only differed significantly from controls regarding physical functioning. The radiography showed considerable radiolucencies under the Thrust Plate. Kinematic parameters indicated a slight impairment of the operated limb. The analysis revealed a decreased hip (28.2%) and knee (51.2%) range of motion during gait. The joint moments on the operated side were reduced in hip (72%) and knee abduction (59%) in comparison to controls. The average electromyographic parameters indicated a significantly higher mean and peak amplitude of the tensor fasciae latae (mean 56%, peak 54%), and gluteus medius (mean 33%, peak 21%) and a lower peak activity of the gluteus maximus (19%).


CONCLUSIONS
The results indicate a generally good functional outcome even though a slightly asymmetrical loading was observed. No major limitations in physical functioning and health-related quality of life was seen. The radiographic signs of loosening might indicate difficulties in achieving the proximal load transfer of this implant.


CONCLUSIONS
The data provided in this study may serve to establish the Thrust Plate Prosthesis as an alternative procedure in total hip replacement in younger patients.
Steens
W
W
Department of Orthopaedics, University Hospital of Münster, Albert-Schweitzer Strasse 33, 48129, Münster, Germany.
Rosenbaum
D
D
Goetze
C
C
Gosheger
G
G
van den Daele
R
R
Steinbeck
J
J
D000203:Activities of Daily Living; D004576:Electromyography / Q000379:methods*; D019544:Equipment Failure Analysis / Q000379:methods*; D005260:Female; D005684:Gait; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006622:Hip Prosthesis; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D007593:Joint Instability / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction; D011788:Quality of Life; D011859:Radiography; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D016896:Treatment Outcome