A comparison between robotic-assisted and manual implantation of cementless total hip arthroplasty.
BACKGROUND
The benefits of robotic techniques for implanting femoral components during THA are still controversial.


OBJECTIVE
The purpose of this study was to prospectively compare the results and complications of robotic-assisted and hand-rasping stem implantation techniques.


METHODS
The minimum followup was 5 years (mean, 67 months; range, 60-85 months). One hundred forty-six primary THAs on 130 patients were included in this study. Robot-assisted primary THA was performed on 75 hips and a hand-rasping technique was used on 71 hips.


RESULTS
At 2 and 3 years postoperatively, the Japanese Orthopaedic Association (JOA) clinical score was slightly better in the robotic-assisted group. At 5 years followup, however, the differences were not significant. Postoperative limb lengths of the robotic-milling group had significantly less variance than the hand-rasping group. At 2 years postoperatively, there was significantly more stress shielding of the proximal femur in the hand-rasping group; this difference was more significant 5 years postoperatively.


CONCLUSIONS
Substantially more precise implant positioning seems to have led to less variance in limb-length inequality and less stress shielding of the proximal femur 5 years postoperatively.


METHODS
Level II, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
Nakamura
Nobuo
N
Center of Arthroplasty, Kyowakai Hospital, 1-24-1 Kishibe-kita, Suita, Osaka, 564-0001, Japan. nnakamu@abox2.so-net.ne.jp
Sugano
Nobuhiko
N
Nishii
Takashi
T
Kakimoto
Akihiro
A
Miki
Hidenobu
H
D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D001843:Bone Cements; D002484:Cementation; D005260:Female; D006621:Hip Joint / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000503:physiopathology / Q000601:surgery*; D010043:Outcome and Process Assessment, Health Care; D010146:Pain; D011183:Postoperative Complications / Q000209:etiology; D011446:Prospective Studies; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D012371:Robotics / Q000295:instrumentation*; D025321:Surgery, Computer-Assisted / Q000009:adverse effects / Q000295:instrumentation*
D001843:Bone Cements