In our institution, we started to perform THA with SuperPATH approach, including preservation of soft tissue around the hip (James Chow et al. Musculoskelet Med 2011) since July 2014, aiming for fast recovery and prevention of hip dislocation. For minimally-invasive approaches, however, there have been a few reports on malalignment of the implants related to shortage of operative field. The purpose of this study is to examine the short-term results of THA using SuperPATH, especially implant alignment. We performed a study of 45 patients (45 hips) with osteoarthritis of the hip joint who had a THA with SuperPATH approach. There were 8 men and 37 women with an average age of 73 years, which were minimally 24 months followed. Dynasty Bioform cup and Profemur Z stem (Microport Orthopaedics) were used for all cases. Patients were clinically assessed with Merle d'Aubigne score and complications. Implant alignment and stability were radiologically evaluated by annual X-ray and CT acquired two months after surgery.Introduction
Materials and methods
Many minimally-invasive approaches have been described in an effort to improve short-term results of total hip arthroplasty (THA), aiming for fast recovery and prevention of dislocation. In our institution, we started to perform THA with SuperPATH approach, including preservation of soft tissue around the hip (James Chow et al. Musculoskelet Med 2011) since July 2014. The purpose of this study is to examine the short-term results of THA using SuperPATH, especially treatment progress of rehabilitation. We performed a study of 30 patients (30 hips) with osteoarthritis of the hip joint who had a THA with SuperPATH approach. There were 4 men and 26 women with an average age of 71 years, which were followed up for 24 months. Patients were clinically assessed with Merle d'Aubigne score, postoperative hip pain during walking by Numerical Rating Scale (NRS:0–10), complications and treatment progress of rehabilitation in regard to moving and activities of daily living. Implant alignment and stability were radiologically evaluated by annual X-ray and CT acquired two months after surgery.Introduction
Materials and methods
Change of the pelvic tilt is an important factor affecting walking after total hip arthroplasty (THA). There are many reports of static evaluation of pelvic tilt by X-ray, however, there are few reports of dynamic evaluation during walking. In this study, we investigated change of pelvic tilt of THA subjects before and after operation during walking using an optical position sensor. 5 normal volunteers (mean age 26.6 years old, Control group) and 10 patients who underwent primary THA due to unilateral osteoarthritis of the hip (mean age 61 years old, THA group) were enrolled. We have measured angle of the hip and inclination of the pelvis in the mid-stance phase of the affected limb during walking using a motion analyzer (MAC3D system) and acquired physical assessment of the hip preoperatively, 3 weeks postoperatively and 3 months postoperatively. The acquired data of inclination of the pelvis was classified as Duchenne or Trendelenburg type compared with that of normal volunteers.Purpose
Subjects and Methods
Few clinical hip score include toe-reach motion after THA (put-on-socks, nail-cutting). Some reports have shown whether THA patients can put on socks or not in daily activity, and not shown how they can do it. The purpose of this study is to investigate real pattern of put-on-socks motion in daily activities after THA, and to evaluate safe range of motion for prevention of hip dislocation. Reviewing clinical chart, we investigated highly frequent pattern in wearing socks motion that would cause hip dislocation in ADL in 100 patients with normal lower extremities except for hip joint more than one year after THA, then, we classified the motion pattern. Using an optical 3-D motion analysis (MAC3D system, Motion Analysis, USA), we measured necessary angle of the hip in 10 THA subjects (mean age at operation 61 years old) one year postoperatively, while the patients make such frequent patterns of movement as above. Simultaneously, individual 3-dimensional skeletal model was reconstructed from CT data and implant CAD data. Driving 3-D skeletal model combined with motion analysis data on display (Zed Hip, LEXI), we calculated angle from posture that hip flexion angle was maximum during wearing-socks motion to impingement point (implant and/or bone) for each direction. ALL joint angle was defined as “zero” in supine position.Background:
Materials and Methods:
Few clinical hip score include toe-reach motion after THA (put-on-socks, shoe-ties, nail-cuttingãf»ãf»ãf») Some reports have shown whether THA patients can put on socks or not in daily activity, and not shown how they can do it. The purpose of this study is to investigate real pattern of put-on-socks motion in daily activities after THA, and to evaluate the characteristics of the motion quantitatively. 1st step Reviewing clinical chart, we investigated highly frequent pattern in wearing socks motion that would cause dislocation in ADL in 100 patients with normal lower extremities except for hip more than one year after THA, then, we classified the motion pattern. 2nd step: Using an optical 3-D motion analysis we measured necessary angles on trunk, hip, knee and ankle in 10 healthy volunteers and 20 THA subjects one month postoperatively, while the volunteers or THA subjects make such frequent patterns of movement based on the 1st step. ALL joint angle was defined as “zero” in static standing position. We also compared the angles in THA subjects with those of the volunteers. Motion analysis technology with optical sensors is; Track 30 infrared reflection sensors on subjects' body surface with infrared camera in the requested motions (MAC3D system, Motion Analysis, USA). Collect 3-D coordinates of 30 sensors' positions over time during subjects' motions. Calculate joint angle, driving 3-D installed skeletal model combined with motion data collected in 2) on display over time (SIMM, Musculographics).Background
Materials and Methods
While numerous studies have examined dislocation caused by basic everyday movements, no objective studies have investigated body positions to minimize risk of dislocation during intercourse. We therefore used a four-dimensional motion analysis system to assess sexual activities in patients who had undergone total hip arthroplasty (THA), to identify body positions displaying less risk of dislocation. Five body-surface infrared sensors were placed on five healthy female volunteers, and maximum hip joint angle was measured. Subjects were asked to take the following three body positions: supine (missionary); top (woman on top); and kneeling (doggy-style). Angle data obtained using body surface markers were combined with three-dimensional skeletal models extracted using CT images obtained from the 24 joints of 16 patients who had undergone THA, to ascertain angles at which collision with the artificial joint or skeleton would occur. Collision angle for: supine position at maximum abduction in flexion was 77±16° in flexion and 82±57° in medial rotation; top position at maximum extension was 36±16° in flexion and 68±53° in medial rotation; top position at maximum flexion was 12±9° in flexion and 14±11° in medial rotation; kneeling position at maximum extension was 115±1° in flexion and 127±44° in medial rotation; and kneeling position at maximum flex-ion was 14±8° in flexion and 17±11° in medial rotation. The present study only assessed risk for dislocation caused by collision with the artificial joint or skeleton, and did not take into account the effects of soft tissue. However, we were able to quantitatively assess angle of the hip joint for some leg positions involved with various common coital positions. The results showed that the supine position at maximum abduction in flexion is relatively safe, since the range of motion before collision would occur was relatively wide. In addition, top and kneeling positions at maximum extension were relatively safe, but caution must be exercised at maximum flexion, as not much extra angle was available in flexion and medial rotation.
We have developed a novel system of 4-dimensional motion analysis after total hip arthroplasty (THA) that can aid in preventing dislocation by assessing safe range of motion for patients in several daily activities. This system uses skeletal structure data from CT and motion capture data from an infrared position sensor. A 3-D model reconstructed from CT data is combined with the motion capture data. Using this system, we analyzed hip motion when getting up from and sitting down in a chair or picking up an object while sitting in a chair in 17 patients (26 hips) who underwent THA. To assess the accuracy of this system’s measurements, open MRI was used to evaluate positions of skin markers against bones in 5 healthy volunteers in various postures. No impingement between bones and/or implants was found in any subjects during any activities. However, mean angle at the point of maximum hip flexion was different for each patient. The open MRI results indicated that average error in hip angle of the present system was within 5 degrees for each static posture. The functional position of the pelvis during daily activities must be taken into account when assessing the real risk of dislocation. The present system enables dynamic analysis involving not only alignment of components and bones of each patient, but also individual differences in characteristics of daily motions. Further investigation using this system can help determine safe ranges of motion for preventing hip dislocation, improving the accuracy of individualized guidance for patients regarding postoperative activities.
