A propensity score-matched comparison between Mako robotic arm-assisted system and conventional technique in total hip arthroplasty for patients with osteoarthritis secondary to developmental dysplasia of the hip.

BACKGROUND: The clinical effectiveness of robotic arm-assisted systems remains unclear for total hip arthroplasty (THA) in patients suffering from osteoarthritis secondary to developmental dysplasia of the hip (DDH). METHODS: Patients with DDH who underwent primary THA were included in this study. We conducted a propensity score-matched comparison between THAs using a robotic arm-assisted system (Mako group) versus those using the manual procedure (manual group) to compare the absolute differences in cup placement angles measured using postoperative computed tomography and those planned preoperatively. RESULTS: A total of 217 patients with osteoarthritis due to DDH met the inclusion criteria. Eighty-four patients were matched as the Mako group and 84 as the manual group. The differences were smaller in the Mako group than the manual group in terms of both inclination and anteversion angles (1.1 ± 1.0 versus 4.2 ± 3.1, respectively; 95% CI, 2.4 to 3.8; p < 0.0001, and 1.2 ± 1.1 versus 5.8 ± 4.0, respectively; 95% CI, 3.7 to 5.5; p < 0.0001). CONCLUSIONS: The robotic arm-assisted system may provide more accurate cup placement in THA for DDH.

Effectiveness and Necessity of Early Postoperative Rehabilitation for Total Hip Arthroplasty / The Japanese Journal of Rehabilitation Medicine

When treating coxarthrosis, each treatment method including conservative treatment, osteotomy, or artificial joint replacement, has an optimal stage for treatment of the disease. Joint preservation surgery has a good result for cases in the early stage, but total hip arthroplasty (THA) is selected for advanced stage hip osteoarthritis, and in Japan, more than a 40000 THAs are performed each year. Good postoperative results lasting up to 15 years are reported today, but, on the other hand, postoperative problems still clearly exist. Deep venous thrombosis/pulmonary embolism (VTE/PTE) are given as perioperative problems, and postoperative dislocation and postoperative range of motion of the hip joint are given as the problems that most relate to ADL. These days, information about THA is abundant so that there is extensive demand for the procedure amongst patients, and elevated technique is demanded of the surgeon. The onset of postoperative VTE/PTE as a lethal complication and interest about its prevention have risen these days with the increase in the number of artificial joint replacements performed in Japan. This time, we introduce a postoperative THA rehabilitation schedule and report the results of our postoperative complication prevention efforts carried out in our hospital. When THA of late years is thought about, for a patient, it is natural that the long-term results are good, and the postoperative satisfaction degree from an early stage is the demand that it is necessary. In consideration of these things, the range of hip motion needed about the origin and preventing dislocation that were one element of long-term satisfaction since only a short-term of normal ADL movement was investigated, and this was viewed from the aspect of joint stability against postoperative dislocation by difference in the approach method of surgery. Finally, we also discussed the importance of early rehabilitation after surgery for the prevention of VTE/PTE as a serious complication of surgery.

Evaluation of Bony Impingement in Regard to InternalRotation Limit after Total Hip Arthroplasty UsingRotation Matrix / Journal of Rural Medicine

<b>Objectives:</b> Bony impingement of the proximal femur on the pelvis is an important factor for dislocation after total hip arthroplasty (THA). We evaluated bony impingement after THA using the rotation matrix derived from postoperative computed tomography (CT) images.<br><b>Patients and Methods:</b> One hundred and seven hip joints were subjected to primary THA via a posterolateral approach. We used the rotation matrix derived from CT images to calculate internal rotation (IR) limit prior to bony impingement, and compared this limit with the intraoperative limit.<br><b>Results:</b> The average calculated IR limit was 63 degrees (range: 30 to 85 degrees). The average intraoperative IR limit was 49 degrees (range: 20 to 70 degrees). The correlation between the intraoperative IR limit (Y) and the calculated IR limit (X) was expressed as Y=8.9+0.66X (R=0.73; p < 0.0001).<br><b>Conclusions:</b> We could show a patient´s safe range of motion prior to bony impingement, and this will be a good indicator for dislocation not occurring during postoperative rehabilitation.