There are concerns of soft-tissue reactions such as metal hypersensitivity or pseudotumors for metal-on-metal (MoM) bearings in hip arthroplasty, however, such reactions around ceramic or polyethylene bearings are incompletely understood. The present study was conducted to examine the capabilities of ultrasound screening and to compare the prevalence of periarticular soft-tissue lesions among various types of bearings. Ultrasound examinations were conducted in 163 hips (153 patients) with arthroplasty after mean a follow-up of 8.1 years (range, 1–22 years). This included 39 MoM hip resurfacings (M-HR) including 30 Birmingham hip resurfacings (BHR) and 9 ADEPT resurfacings; 36 MoM total hip arthroplasties (M-THA) with a large femoral head including 26 BHR and 10 ADEPT bearings; 21 ceramic-on-ceramic THAs (C-THA) of Biolox forte alumina bearings; 24 THAs with a conventional polyethylene liner (cPE-THA) including 19 Lubeck and 5 Omnifit systems; and 43 THAs with a highly cross-linked polyethylene liner (hxPE-THA) including 28 Crossfire and 15 Longevity liners. All procedures were performed in the lateral position through the posterior approach without trochanteric osteotomy. The M-HR group had a significantly higher frequency of male patients than the C-THA, cPE-THA, and hxPE-THA groups, and the patients in the M-HR group were younger than those in the other four groups. Ultrasound images were acquired as a still picture and in video format as the hip moved in flexion and rotation, and 4 qualitative classifications for periarticular soft-tissue reactions were determined as normal pattern, joint-expansion pattern (marked hypoechoic space between the anterior capsule and the anterior surface of the femoral component), cystic pattern (irregularly shaped hypoechoic lesions), and mass pattern (a large mass extending anterior to the femoral component). Magnetic resonance imaging (MRI) was subsequently performed in 45 hips with high-frequency encoding bandwidths. For the reliability of ultrasound screening, positive predictive value, negative predictive value, and the accuracy of the presence of abnormal patterns on ultrasound were calculated using the abnormal lesions on MRI as a reference.Purpose
Methods
Preoperative planning is an essential procedure for successful total hip arthroplasty. Many studies reported lower accuracy of two-dimensional analogue or digital templating for developmentally dysplastic hips (DDH). There have been few studies regarding the utility of three-dimensional (3D) templating for DDH. The aim of the present study is to assess the accuracy and reliability of 3D templating of cementless THA for hip dysplasia. We used 86 sets of 3D-CT data of 84 patients who underwent consecutive cementless THA using an anatomical stem and a rim-enlarged cup. There were six men and 78 women with the mean age of 58 years. The diagnosis was developmental dysplasia in 70 hips and osteonecrosis in 14 hips and primary osteoarthritis in 2 hips. There were 53 hips in Crowe group I, 11 hips in Crowe group II and 6 hips in Crowe group III. Each operator performed 3D templating prior surgery using a planning workstation of CT-based navigation system. Planned-versus-achieved accuracy was evaluated. The templating results were categorized as either exact size or +/− 1 size of implanted size. To assess the intra- and inter-planner reliabilities, 3D templating was performed by two authors blinded to surgery twice at an interval of one month. Kappa values were calculated. The accuracy and the intra- and inter-planner reliabilities were compared between the DDH group (70 hips) and the non DDH group (16 hips).Introduction
Methods
The shuck test was widely used to assess the overall soft-tissue tension around the hip joint during surgery. There have been few attempts to standardize how one evaluates soft tissue tension in total hip arthroplasty. The aim of this study was to ask how reliable the shuck test was as a measure of soft tissue tension in total hip arthroplasty. First, we assessed the intra- and inter-examiner variability of the force generated in the shuck test. Next, we asked how the strength of traction forces and joint position on the distance of displacement of the prosthetic head at surgery. Twenty-one hip surgeons, consisting of seven experienced hip surgeons, seven junior hip surgeons, and seven surgeons in training were included in the first study. Test subjects were instructed to pull a traction gauge with their customary range of force. Each subject performed two sets of the shuck test in one week interval. Eighteen patients who had cementless THA through postero-lateral approach using 3D-CT based navigation system were enrolled in the second study. After implantation of components, the leg was pull caudally using our original device [Fig. 1]. The strength of applied traction force was 20 %, 30 %, 40 % and 50 % of body weight of each patient. The distance of displacement of a prosthetic head during traction was recorded at flexion angles of 0, 15, 30 and 45 degrees using the navigation system. Internal or external rotation of legs was controlled within 5 degrees.Introduction
Methods
Ceramic-on-ceramic bearings in total hip arthroplasty (CoC THA) have theoretical advantages of wear resistance and favorable biocompatibility of ceramic particles to the surrounding bony and soft tissue. Long-time durability of CoC THA has been expected, however, clinical results over 10 years after operation were scarcely reported. In the present study, clinical results at follow of 10 years were examined for CoC THAs with a changeable femoral neck which allowed correction of anteversion of the femoral component in cases with abnormal femoral anteversion in dysplastic hips. During 1997 and 2000, 203 cementless CoC THAs in 158 patients were conducted in our hospital. Six patients died because of unrelated causes and 5 patients were lost to followup, and the remaining 188 hips in 147 patients were analyzed at the mean followup period of 10.8 years (3.7 to 13.5). There were 24 men and 123 women, and the average age at operation was 54 years (26 to 73). The hip diseases for operation were osteoarthritis in 165 hips, osteonecrosis of the femoral head in 21 hips and failure of hemiarthroplasty in 2 hips. The operation was performed in the lateral position through the posterior approach without trochanteric osteotomy. The articulation was composed of Biolox forte alumina liner fitted into beads-coated hiemispherical titanium shell, and a 28-mm Biolox forte alumina femoral head (Cremascoli). The femoral component was either AnCA stem or custom-designed stem, coupled with a modular neck allowing selection of 5 variable offsets and anteversions (Cremascoli). Clinical and radiological findings, and complications during the followup period were analyzed.Purpose
Methods
Current standard cups of metal on metal resurfacing hip arthroplasty (RHA) have no dome holes and it is very difficult for surgeons to confirm full seating of these cups. This sometimes results in gap formation between the cup and acetabular floor. Although the incidence of initial gaps using modular press-fit cups with dome screw holes has been reported to range from 20 to 35%, few studies have reported the incidence of gap formation with monoblock metal cups and its clinical consequences in RHA. The purpose of this study was to investigate retrospectively the incidence of initial gap formation and whether the initial gap influences the clinical results in RHA. RHA was performed on 166 hips of 146 patients using the Birmingham Hip Resurfacing (BHR) (MMT, UK) between 1998 and 2007. Mean age at operation was 48.7 years (range, 19-85 years). Mean duration of follow-up was 6.9 years (2.0-10.6). Acetabular reaming was performed with the use of hemispherical reamers and the reamer size was increased up to an odd number diameter which provided tight rim fit in the antero-posterior direction. The same size hemispherical provisional cup with dome holes and slits was used to check the cavity for complete seating. If the provisional cup could not be seated on the floor, reaming was repeated with the same reamer to remove the rim bump until full seating was achieved. Acetabular cups of 1mm larger diameter were impacted into the acetabulum by a press-fit technique. After press-fit fixation, the stability of the cups was confirmed with a synchronized movement of the pelvis and the cup inserter by applying a gentle torque. Clinical evaluation was performed using WOMAC at the latest follow-up. Radiographic assessments were performed using radiographs immediately after the surgery, at 3 weeks, 3 months, 1 year, and then annually thereafter. We evaluated the height of the gap between the cup and acetabular surface, cup inclination angle, cup migration and the time to gap filling. To investigate the relationship between the magnitude of the gap and the radiographic results, the patients were divided into two groups according to the height of the initial gap; the cases with a gap of less than 3 mm on the initial radiograph were grouped into a small gap group, the cases with a gap of 3mm or more were grouped into a large gap group. We compared the changes in the height of the gap, in the cup inclination angle and the cup migration between the groups.Introduction
Material and Method
The initial mechanical stability of cementless femoral stems in total hip arthroplasty is an important factor for stable biological fixation. Conversely, insufficient initial stability can lead to stem subsidence, and excessive subsidence can result in periprosthetic femoral fracture due to hoop stress. The surface roughness of stems with a surface coating theoretically contributes to initial mechanical stability by increasing friction against the bone, however, no reports have shown the effect of surface roughness on stability. The purpose of this study was to evaluate the effect of differences in surface roughness due to different surface treatments with the same stem design on the initial stability. Proximally titanium plasma-sprayed femoral stems (PS stem) and proximally grit-blasted stems (GB stem) were compared. The stem design was identical with an anatomic short tapered shape for proximal fixation. The optimum size of PS stem based on 3D templating was implanted in one side of 11 pairs of human cadaveric femora and the same size of GB stems was implanted in the other side. After implantation, the specimens were fixed to the jig of a universal testing machine in 25cm of entire length so that the long axis of the femur was positioned at 15-degrees adduction to the vertical. Vertical load tests were conducted under 1 mm/minute of displacement-controlled conditions. After 200 N of preload to eliminate the variance in the magnitude of press-fit by manual implantation, load was applied until periprosthetic fracture occurred.Introduction
Materials and Methods
There have been few reports with efficient treatments for neglected distal tibiofibular syndesmosis disruption. Here we will report four cases of successful anatomical reconstruction with autologous gracilis tendon, using the interference fit anchoring (IFA) system. All four cases were males between 20 and 58 years of age at the time of surgery (mean age 36 years). The post-injury period to surgery was between 7 and 59 months (mean 20.1 months), with the consultation period being from 5 to 19 months (mean 9.5 months). Radiographs at the time of injuries were all malleolar fractures of pronation-external rotation (PE) stage 3 in the Lauge-Hansen classification. Stress tests for distal tibiofibular syndesmosis were positive in all cases (dilation more than 2 mm). Arthroscopic drilling was conducted in two cases with a cartilaginous injury of trochlea of talus. Distal tibiofibular syndesmosis was anatomically repositioned and was fixed with screws after bony and soft tissues within the tibiofibular syndesmosis were removed and fibular adhesion was dissected. Ipsilateral autologous gracilis tendon was passed through foramen in the insertion of the anterior inferior tibiofibular tendon on tibia and fibula, and was fixated using the IFA system. The preoperative Japanese society for surgery of the foot (JSSF) score was from 26 to 74 points (mean 43.5) and postoperative JSSF score was from 67 to 100 (mean 89.5). In a case where there was a poor outcome, five years of post injury had passed before the surgery. Although the JSSF score improved to 67 points postoperatively (from the preoperative score of 26) in this case, arthroscopic arthrodesis was conducted 5 months postoperatively due to persistent pain. Anatomical reconstruction with autologous gracilis tendon using the IFA system showed a favorable functional prognosis overall. However, there was a case with progressive degenerated changes of injured distal tibiofibular syndesmosis due to a prolonged post-injury period resulted in a poor outcome.
