OBJECTIVETo explore early clinical effect of acetabular cup in total hip replacement for the treatment of Crowe II developmental dysplasia of hip.

METHODSEighteen patients (18 hips) with Crowe type II developmental dysplasia of hip were treated with total hip replacement from September 2001 to July 2013. Among them,including 13 males and 5 females aged from 42 to 60 years old with an average of 47.6 years old; the courses of diseases ranged from 9 to 22 years with an average of 13.5 years. All the patients had hip joint pain, limb shortening and limited hip function before operation. Harris score of hip joint were used to evaluate recovery of function at 1 day and 12 months after operation. Prosthetic coverage of acetabular cup at 1 week after operation was observed by using radiography.

RESULTSEighteen patients (18 hips) were followed up from 12 to 24 months with an average 17 months. All incisions were healed at stage I. No deep vein thrombosis, hip dislocation, periprosthetic joint infection and prosthesis loosening were occurred. No revision surgery during follow-up period. Prosthetic coverage of acetabular cup was more than 80% at 1 week after operation. Harris score were increased from 42.67 ± 5.06 before operation to 94.79 ± 3.27 at 12 months after operation (t = -45.269, P < 0.001).

CONCLUSIONFor type Crowe II developmental dysplasia of hip patients, 15° face-changing acetabular cups in THR could obtain higher actebular component coverage rate and satisfactory early clinical effects.

Acetabulum ; surgery ; Adult ; Arthroplasty, Replacement, Hip ; instrumentation ; Female ; Follow-Up Studies ; Hip Dislocation, Congenital ; surgery ; Hip Joint ; surgery ; Hip Prosthesis ; Humans ; Male ; Middle Aged

BACKGROUND: To augment cement-bone fixation, Dr. Hironobu Oonishi attempted additional physicochemical bonding through interposition of osteoconductive crystal hydroxyapatite (HA) granules at the cement-bone interface in 1982. He first used the interface bioactive bone cement (IBBC) technique in 12 selected patients (12 hips) in 1982 (first stage) and followed them for 2 years. In 1985, the technique was applied in 25 total hip arthroplasty (THA) patients (second stage) and the effects were investigated by comparing the side with the IBBC technique and the other side without the IBBC technique. He has employed this technique in all THA patients since 1987 (third stage). METHODS: In the IBBC technique, HA granules (2 to 3 g) were smeared on the bone surface just before the acetabular and femoral components were cemented. In the first stage, 12 hips were operated using the IBBC technique in 1982. In the second stage, THA was performed without the IBBC technique on one side and with the IBBC technique on the other side within 1 year in 25 patients. In the third stage, THA was performed with the IBBC technique in 285 hips in 1987. RESULTS: In the first stage patients, implant loosening was not detected at 30 years after operation. In the second stage patients, revision was required in 7 hips without the IBBC technique due to cup loosening (5 hips) and stem loosening (2 hips), whereas no hip was revised after THA with the IBBC technique at 26 years after operation. In the third stage patients, the incidence of radiolucent lines and osteolysis was very few at 25 years after operation. CONCLUSIONS: The long-term follow-up of THA performed around the inception of the IBBC technique has revealed low incidences of radiolucent lines, osteolysis, and revision surgery.
Adult ; Aged ; Aged, 80 and over ; *Arthroplasty, Replacement, Hip/adverse effects/instrumentation/methods ; *Bone Cements/adverse effects/therapeutic use ; Bone-Implant Interface/physiology ; Follow-Up Studies ; Hip/diagnostic imaging/surgery ; Humans ; Hydroxyapatites/therapeutic use ; Middle Aged ; Young Adult

In order to help a surgeon to determine a proper canal filing cutting path in a hip replacement operation conveniently, this paper presents a kind of probe with combined structure. Firstly, the doctor can use this kind of combined probe to choose canal filing cutting path. Then, the doctor can use computer to guide the surgeon to file femoral cavity along the selected canal filing cutting path. Through hip replacement corpse experiments, filing effects and used time of using combined probe group and separate control group were analyzed. The experiment results showed that the methods introduced in this paper could lower the difficulty of hip replacement operations, improve the implantation of hip stem prostheses further, and reduce the incidence of surgical complications.
Arthroplasty, Replacement, Hip ; Femur ; Hip Prosthesis ; Humans ; Surgery, Computer-Assisted ; instrumentation

INTRODUCTIONHip hemiarthoplasties are commonly performed for displaced femoral neck fractures. Considerable differences of opinion exists regarding the choice between unipolar and bipolar designs. The main theoretical advantage of a bipolar over a unipolar prosthesis is the reduction of acetabular erosion due to movement taking place within the implant rather than at the acetabular implant interface. It is thus hypothesised that bipolar prostheses lead to better long-term functional outcomes with less complications. In this study, we aimed to compare unipolar (Moore's) and bipolar hemiarthroplasty looking specifically for differences in 1) pain and functional hip scores; 2) rates of acetabular erosion, component migration and revision surgery; and 3) rates of postoperative morbidity.

MATERIALS AND METHODSInclusion criteria were 1) age more than or equal to 65 years; 2) displaced femoral neck fracture of non-pathologic origin; 3) normal cognitive function; 4) ambulatory with or without assistive devices prior to the fracture; and 5) treated with a primary prosthetic replacement. Of the 193 patients that were available for review, 118 were in the Moore's group and 75 in the bipolar group. Postoperatively, patients were assessed with regards to pain, satisfaction, Modified Harris hip score and Oxford hip score. Standard anteroposterior pelvis and lateral hip radiographs were obtained at regular intervals. These were analysed specifically with regards to acetabular erosion and component migration.

RESULTSThere was no significant difference between a Moore's and a bipolar prosthesis regarding hip pain, functional hip scores, rates of acetabular erosion, component migration, revision surgery and complications rates.

CONCLUSIONUse of the more expensive bipolar prosthesis in elderly and premorbidly ambulant patient is not justified.

Age Factors ; Aged ; Aged, 80 and over ; Arthroplasty, Replacement, Hip ; instrumentation ; Female ; Femoral Neck Fractures ; surgery ; Hemiarthroplasty ; instrumentation ; Hip Prosthesis ; Humans ; Male ; Postoperative Complications ; epidemiology ; Prosthesis Design ; Prosthesis Failure ; Reoperation ; Treatment Outcome

One of the most important issues in the modern total hip arthroplasty (THA) is the bearing surface. Extensive research on bearing surfaces is being conducted to seek an ideal bearing surface for THA. The ideal bearing surface for THA should have superior wear characteristics and should be durable, bio-inert, cost-effective, and easy to implant. However, bearing surfaces that are currently being implemented do not completely fulfill these requirements, especially for young individuals for whom implant longevity is paramount. Even though various new bearing surfaces have been investigated, research is still ongoing, and only short-term results have been reported from clinical trials. Future bearing surfaces can be developed in the following ways: (1) change in design, (2) further improvement of polyethylene, (3) surface modification of the metal, (4) improvement in the ceramic, and (5) use of alternative, new materials. One way to reduce wear and impingement in THA is to make changes in its design by using a large femoral head, a monobloc metal shell with preassembled ceramic liner, dual mobility cups, a combination of different bearing surfaces, etc. Polyethylene has improved over time with the development of highly crosslinked polyethylene. Further improvements can be made by reinforcing it with vitamin E or multiwalled carbon nanotubes and by performing a surface modification with a biomembrane. Surface modifications with titanium nitride or titanium niobium nitride are implemented to try to improve the metal bearings. The advance to the fourth generation ceramics has shown relatively promising results, even in young patients. Nevertheless, further improvement is required to reduce fragility and squeaking. Alternative materials like diamond coatings on surfaces, carbon based composite materials, oxidized zirconium, silicon nitride, and sapphire are being sought. However, long-term studies are necessary to confirm the efficacy of these surfaces after enhancements have been made with regard to fixation technique and implant quality.
Arthroplasty, Replacement, Hip/*instrumentation ; *Hip Prosthesis ; Humans ; Metals ; *Prosthesis Design ; Surface Properties ; *Weight-Bearing

BACKGROUND: Several studies have shown that better placement of the acetabular cup and femoral stem can be achieved in total hip arthroplasty (THA) by using the computer navigation system rather than the free-hand alignment methods. However, there have been no comparisons of the relevant clinical advantages in using the computer navigation as opposed to the manual intraoperative measurement devices. The purpose of this study is to determine whether the use of computer navigation can improve postoperative leg length discrepancy (LLD) compared to the use of the measurement device. METHODS: We performed a retrospective study comparing 30 computer-assisted THAs with 40 THAs performed using a simple manual measurement device. RESULTS: The postoperative LLD was 3.0 mm (range, 0 to 8 mm) in the computer-assisted group and 2.9 mm (range, 0 to 10 mm) in the device group. Statistically significant difference was not seen between the two groups. CONCLUSIONS: The results showed good equalization of the leg lengths using both computed tomography-based navigation and the simple manual measurement device.
Acetabulum/surgery ; Adult ; Aged, 80 and over ; Arthroplasty, Replacement, Hip/instrumentation/*methods ; Body Weights and Measures ; Female ; Femur/surgery ; Humans ; Leg ; Leg Length Inequality/*surgery ; Male ; Middle Aged ; Retrospective Studies ; Surgery, Computer-Assisted ; Young Adult

Various systems of computer-assisted orthopaedic surgery (CAOS) in total hip arthroplasty (THA) were reviewed. The first clinically applied system was an active robotic system (ROBODOC), which performed femoral implant cavity preparation as programmed preoperatively. Several reports on cementless THA with ROBODOC showed better stem alignment and less variance in limb-length inequality on radiographic evaluation, less incidence of pulmonary embolic events on transesophageal cardioechogram, and less stress shielding on the dual energy X-ray absorptiometry analysis than conventional manual methods. On the other hand, some studies raise issues with active systems, including a steep learning curve, muscle and nerve damage, and technical complications, such as a procedure stop due to a bone motion during cutting, requiring re-registration and registration failure. Semi-active robotic systems, such as Acrobot and Rio, were developed for ease of surgeon acceptance. The drill bit at the tip of the robotic arm is moved by a surgeon's hand, but it does not move outside of a milling path boundary, which is defined according to three-dimensional (3D) image-based preoperative planning. However, there are still few reports on THA with these semi-active systems. Thanks to the advancements in 3D sensor technology, navigation systems were developed. Navigation is a passive system, which does not perform any actions on patients. It only provides information and guidance to the surgeon who still uses conventional tools to perform the surgery. There are three types of navigation: computed tomography (CT)-based navigation, imageless navigation, and fluoro-navigation. CT-based navigation is the most accurate, but the preoperative planning on CT images takes time that increases cost and radiation exposure. Imageless navigation does not use CT images, but its accuracy depends on the technique of landmark pointing, and it does not take into account the individual uniqueness of the anatomy. Fluoroscopic navigation is good for trauma and spine surgeries, but its benefits are limited in the hip and knee reconstruction surgeries. Several studies have shown that the cup alignment with navigation is more precise than that of the conventional mechanical instruments, and that it is useful for optimizing limb length, range of motion, and stability. Recently, patient specific templates, based on CT images, have attracted attention and some early reports on cup placement, and resurfacing showed improved accuracy of the procedures. These various CAOS systems have pros and cons. Nonetheless, CAOS is a useful tool to help surgeons perform accurately what surgeons want to do in order to better achieve their clinical objectives. Thus, it is important that the surgeon fully understands what he or she should be trying to achieve in THA for each patient.
Arthroplasty, Replacement, Hip/instrumentation/*methods ; Humans ; *Robotics ; Stereotaxic Techniques ; *Surgery, Computer-Assisted

OBJECTIVETo investigate the feasibility of hip arthroplasty in the treatment of elderly patients with Evans I-III intertrochanteric fracture of femur by analyzing its biomechanics characters.

METHODSWe solved the CT digital image files with the graphics processing software Mimics at DICOM 3.0 standard, and reconstructed the three-dimensional entity of femur with CAD modeling software Unigraphics. Then the fracture line was defined in the model as the line between the tip of greater trochanter and inferior margin of small trochanter, above which the upper bone was removed. Afterwards the two prosthesises with different stem lengths (120 mm and 170 mm) were implanted into the fracture model respectively as hip arthroplasty with 3 mm bone cement layer between prosthesis and femur, and the bone defect was repatched with 5 mm bone cement layer. A three-dimensional finite element model was established with finite element analysis software ABAQUS 6.5. We formulated different material parameters under the stress condition standing with single leg to build the stress distribution map of the femur prosthesis, and took 5 loci of region of stress concentration to calculate the mean value of stress.

RESULTSThe stress distribution maps of the short and long stem length prothesises were similar. And there were two areas of stress concentration, including the upper portion and the lower portion close to the joint of the prosthesis stem, and the stress concentration in the junction part was obviously between the lower portion and the upper area of the small trachanter. The stress reached the first concentration area at the junction and then gradually reached the second concentration area at the interior terminal of the stem. While the stress gradually increased along the lateral prosthesis stem, and reached the stress concentration area at the end.

CONCLUSIONSThe stress distribution maps in the femur prosthesises are similar between hip arthroplasty in the treatment of intertrochanteric fracture of femur and the traditional hip arthroplasty surgery. The peak stress values are higher in the long stem prosthesis in the treatment of intertrochanteric fracture of femur than the short type, while they are under the rupture value of the metal.

Aged ; Arthroplasty, Replacement, Hip ; instrumentation ; methods ; Biomechanical Phenomena ; Bone Cements ; Computer Simulation ; Female ; Finite Element Analysis ; Hip Fractures ; surgery ; Hip Prosthesis ; Humans ; Image Processing, Computer-Assisted ; Software ; Stress, Mechanical

OBJECTIVETo evaluate the difference of clinical outcomes and radiological outcomes through meta-analysis on the total hip arthroplasty (THA) between hydroxyapatite(HA) coating and non-HA coating femoral stems.

METHODSWe searched the MEDLINE, Embase, Cochrane library and CBM for published randomized controlled trial (RCT) comparing HA coating and non-HA coating femoral stems in primary THA clinical outcomes with Harris hip score and incidence postoperative thigh pain, radiological outcomes with presence of endosteal condensation and radioactive line on the prothesis, heterotopic ossification. Data analysis were performed using RevMan 5.0(the Cochrane Collaboration).

RESULTSTen studies and 917 hips into our analysis, with 464 hips in HA groups and 453 hips in non-HA groups. The combined results of the meta-analysis indicated there was no statistical differences between the two groups on postoperative Harris hip score(WMD = 3.04, 95%CI:-4.47-10.54, P = 0.43) , there was statistical difference on incidence postoperative thigh pain (RR = 0.56, 95%CI:0.33-0.94, P = 0.03) . There were no significant differences between the two groups on presence of endosteal condensation (RR = 1.01, 95%CI:0.91-1.11, P = 0.91), presence of radioactive line (RR = 0.99, 95%CI:0.88-1.11, P = 0.83) and incidence of heterotopic ossification (RR = 0.97, 95%CI:0.77-1.21, P = 0.77).

CONCLUSIONSThere are no clinical and radiological benefits in the use of HA coating femoral stems in Primary THA, there is not enough evidence prove the HA can reduce the incidence postoperative thigh pain.

Arthroplasty, Replacement, Hip ; instrumentation ; Coated Materials, Biocompatible ; Durapatite ; Femur ; Hip Prosthesis ; Humans ; Randomized Controlled Trials as Topic ; Treatment Outcome

BACKGROUND: There has been controversy whether methylmethacrylate precoating of the cemented femoral stem is a solution for aseptic loosening or rather contributes to increased failure rates in cemented total hip arthroplasties. METHODS: On a retrospective basis, we analyzed 76 primary hybrid total hip arthroplasties from 63 patients with precoated, cemented femoral stems between October 1990 and December 1995. The mean age of the patients was 46.8 years (range, 22 to 77 years) with a minimum follow-up of 14 years (mean, 15.5 years; range, 14 to 19.5 years). Third generation cementing techniques were employed in all cases. RESULTS: Twenty-four out of 76 cases (31.6%) showed aseptic loosening of the femoral stems, of which 23 stems were revised at an average revision time of 8 years (range, 3 to 14.8 years). The main mode of loosening was cement-stem interface failure in 22 hips (91.7%). Twenty-one out of 24 failed hips (87.5%) demonstrated C2 cementing grades (p < 0.001). Kaplan-Meier survivorship analysis using radiographic aseptic loosening of the femoral stem as the endpoint for failure showed survival rates of 76.5% at 10 years (95% confidence interval [CI], 71.4 to 81.6) and 63.2% at 19 years (95% CI, 57.3 to 69.1). CONCLUSIONS: An early failure of the precoated femoral stem in this study was mainly due to an insufficient cementing technique. Achievement of good cement mantle may improve the survival rates.
Adult ; Aged ; Aged, 80 and over ; Arthroplasty, Replacement, Hip/*instrumentation ; *Coated Materials, Biocompatible ; Equipment Failure Analysis ; Female ; Femur Head Necrosis/diagnosis/surgery ; *Hip Prosthesis ; Humans ; Kaplan-Meier Estimate ; Male ; Methylmethacrylate ; Middle Aged ; Prosthesis Failure ; Retrospective Studies ; Treatment Outcome ; Young Adult