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Background: Preoperative planning is fundamental for total hip arthroplasty. This study investigated the optimal femoral neck level for measuring femoral anteversion to predict postoperative stem anteversion in developmental dysplasia of the hip and determined the predictive role of average anteversion based on the sagittal 3-point fixation.Methods: Sixty-two Crowe type II/III dysplastic hips that underwent total hip arthroplasty were retrospectively analyzed. Preoperative and postoperative anteversion was measured via 2-dimensional computed tomography. Anterior and posterior cortex anteversions were measured at 6 levels of the proximal femur. Femoral anteversion at each level was calculated. Average anterior (lesser trochanter) and posterior cortex anteversions (femoral neck) were calculated based on the sagittal 3-point fixation.Results: From the lesser trochanter to head-neck junction, femoral anteversion decreased gradually from more to less than stem anteversion. For hips with femoral neck height ≥10 mm, femoral anteversion at the 10-mm level above the lesser trochanter proximal base showed no significant difference with stem anteversion, with a good correlation for the single-wedge and an excellent correlation for the double-wedge stem. Average anterior (lesser trochanter proximal base) and posterior cortex anteversions (femoral neck at 10 mm above the lesser trochanter proximal base) showed no significant difference from stem anteversion, with excellent correlations.Conclusion: For Crowe type II/III hips with femoral neck height ≥10 mm, the 10-mm level above the lesser trochanter proximal base is an optimal choice for measuring femoral anteversion to predict postoperative stem anteversion. The average of anterior cortex anteversion at the lesser trochanter and posterior cortex anteversion at the femoral neck has a predictive role. [ABSTRACT FROM AUTHOR]

Background: A number of methods for reduction in high hip dislocation in total hip arthroplasty (THA) are time-consuming and laborious, and require great surgical skills. This study aimed to introduce a new reduction technique to achieve rapid, safe, and easy reduction in high hip dislocation.Methods: We retrospectively reviewed 74 THA patients (82 hips; 44 women, 30 men) with severe hip dysplasia who underwent direct leverage using a Hohmann retractor into the anatomical acetabulum without femoral shortening osteotomy between September 2007 and January 2014. Forty-nine hips were classified as Crowe III and 33 hips were classified as Crowe IV. The mean follow-up period was 5.1 years (range 2-8).Results: Mean Harris Hip Score increased from 42.1 (range 24-71) before surgery to 89.9 (range 76-100) at final follow-up examination. The legs were lengthened by a mean of 3.0 cm (range 1.1-5.5) and 2.5 cm (range 1.1-3.5) in Crowe III hips and 3.6 cm (range 1.9-5.5) in Crowe IV hips postoperatively. The average leg-length discrepancy at the final follow-up examination was 0.4 cm (standard deviation 0.5 cm). One greater trochanteric fracture occurred during the hip reduction process. One patient developed femoral nerve palsies and recovered completely at 3 weeks postoperatively.Conclusion: Direct leverage using the Hohmann retractor for the reduction in high hip dislocation in THA without femoral shortening osteotomy is simple, safe, and effective. [ABSTRACT FROM AUTHOR]

Background: Recommendations for minimum cup coverage based on anteroposterior radiographs are widely used as an intraoperative guide in total hip arthroplasty for patients with developmental dysplasia of the hip. The purpose of this study was to examine the validity of two-dimensional (2D) measurement of coverage with three-dimensional (3D) coverage and to identify parameters for determining the 3D coverage during surgery.Methods: We developed a technique to accurately reproduce the intraoperative anatomic geometry of the dysplastic acetabulum and measure the 3D cup coverage postoperatively. With this technique, we retrospectively analyzed the difference and correlation between 2D and 3D measurements of native bone coverage in 35 patients (45 hips) with Crowe II or III DDH. Linear regression analysis was performed to examine the intraoperative parameters related to coverage. The mean follow-up period was 7.64 years (range, 6.1-9.5 years).Results: There was a significant difference and a fair correlation between 2D and 3D measurements. The 2D measurement underestimated the 3D cup coverage by approximately 13%. An excellent linear relationship was noted between the 3D coverage/uncoverage and the height of the uncovered portion (R2 = 0.8440, P < .0001). There was no case of loosening or revision during the follow-up.Conclusion: Current minimum cup coverage recommendations based on 2D radiograph measurements should not be used as a direct intraoperative guide. The height of the uncovered portion is a useful parameter to determine the 3D coverage during surgery. [ABSTRACT FROM AUTHOR]

Background: This study compares the outcome between THA with and without femoral shortening osteotomy for unilateral mild to moderate high hip dislocation in developmental dysplasia of the hip patients.Methods: The data on 42 hips in 42 patients who had undergone THA for unilateral mild to moderate high hip dislocation were retrospectively reviewed after being prospectively collected. In 22 patients, hips were reduced by soft tissue release and direct leverage using an elevator, without the osteotomy. The remaining 20 patients were treated with a subtrochanteric transverse shortening osteotomy. The mean follow-up of patients was 5 years (standard deviation = 1.0) for the nonosteotomy group and 6.2 years (standard deviation = 1.6) for the osteotomy group.Results: The Harris Hip Score significantly improved in both groups. In the nonosteotomy group, we observed a lower leg length discrepancy compared with the osteotomy group (0.4 cm and 2.2 cm, respectively). Four patients (18.2%) in the nonosteotomy group and 15 patients (75%) in the osteotomy group developed a limp (P < .0001). Three patients (13%) developed femoral nerve palsy in the nonosteotomy group, but they all recovered completely within 6 months after the surgery. Nineteen patients in the nonosteotomy group showed knee valgus deformity immediately after the surgery but only 4 cases in the osteotomy group.Conclusion: Compared with THA with femoral shortening osteotomy, THA without the osteotomy was associated with a lower number of patients who developed a limp at the end of follow-up; however, the rehabilitation was slower and more difficult, and a larger number of patients showed reversible nerve palsy and knee valgus deformity. [ABSTRACT FROM AUTHOR]

Background: We sought to evaluate posterosuperior placement of the acetabular component at the true acetabulum during acetabular reconstruction in patients with Crowe type-IV developmental dysplasia of the hip.Methods: Using pelvic computed tomography and image processing, we developed a two-dimensional mapping technique to demonstrate the distribution of preoperative three-dimensional cup coverage at the true acetabulum, determined the postoperative location of the acetabular cup, and calculated postoperative three-dimensional coverage for 16 Crowe type-IV dysplastic hips in 14 patients with a mean age of 52 years (33-78 years) who underwent total hip arthroplasty. Mean follow-up was 6.3 years (5.5-7.3 years).Results: On preoperative mapping, the maximum three-dimensional coverage using a 44-mm cup was 87.31% (77.36%-98.14%). Mapping enabled the successful replacement of 16 hips using a mean cup size of 44.13 mm (42-46 mm) with posterosuperior placement of the cup. Early weight-bearing and no prosthesis revision or loosening during follow-up were achieved in all patients. The postoperative two-dimensional coverage on anteroposterior radiographs and three-dimensional coverage were 96.15% (89.49%-100%) and 83.42% (71.81%-98.50%), respectively.Conclusion: This technique may improve long-term implant survival in patients with Crowe-IV developmental dysplasia of the hip undergoing total hip arthroplasty by allowing the use of durable bearings, increasing host bone coverage, ensuring initial stability, and restoring the normal hip center. [ABSTRACT FROM AUTHOR]

Purposes: To examine the clinical outcomes of patients treated with a nickel-titanium shape-memory sawtooth-arm embracing clamp (Ni-Ti SSEC) in complex femoral revision surgery.Methods: We retrospectively evaluated the outcomes for 21 complex femoral revision hip arthroplasties that we treated using an Ni-Ti SSEC. The Ni-Ti SSEC was used for various procedures, including the fixation of extremely long cortical windows (11 patients), femoral shaft osteotomy (4 patients), an extended trochanteric osteotomy (3 patients), and protection of a penetrated femoral cortex by a primary stem (3 patients). All patients received follow-up care for an average of 48.2 months.Results: The mean time of Ni-Ti SSEC insertion intraoperatively was 6 minutes. The mean Harris Hip Score improved from 21.2 points before revision surgery to 83.1 points at the most recent examination. No implant failures or malunions occurred. Dislocation and deep infection occurred in 1 case during the follow-up period.Conclusions: Our results show that the embracing clamp is a simple and valid method for fixing osteotomies in treating complex femoral revision surgery. [ABSTRACT FROM AUTHOR]

The combined anteversion surgical technique has been proposed and used in clinical practice. To more objectively evaluate the feasibility of this surgical technique using combined anteversion concept for DDH patients, we studied 34 DDH patients (40 hips) in this research. Every patient underwent pelvic CT scans before and after surgery and the HHSs were recorded. Optimal range of joint motion was measured using a three-dimensional reconstruction technique and a dynamic measurement technique. The results revealed that joint function met the requirements of daily life and the range of motion was not over-limited by impingement between the prosthesis and the skeleton. Moreover, the combined anteversion was found to be the most critical parameter in this study. [ABSTRACT FROM AUTHOR]

Acetabular osteophytes are common during total hip arthroplasty (THA). However, the fate and role of superolateral osteophytes of the acetabulum after THA remain unclear. The present study reviewed a series of radiographic changes in the osteophytes on the superolateral region of the acetabulum in 35 hips. The mean follow-up period was 42.2months. The results revealed that the osteophytes that were not in contact with the superolateral edge of acetabular cup were gradually absorbed after THA. In contrast, the osteophytes that were in contact with the superolateral edge of the acetabular cup underwent remodeling, formed regular trabecula, were stress bearing, and eventually integrated with the acetabular cup and the original acetabular bone, and should play a role in stabilizing the acetabular cup. [ABSTRACT FROM AUTHOR]

Abstract: The combined anteversion technique has been proposed recently and proved to be an applicable technique in general THA. The corresponding author routinely applied this approach to DDH patients in clinical practice. The current study aimed to provide clinical evidence for this approach. We studied 35 DDH patients (47 hips). Every patient underwent pelvic CT scans before and after surgery and the HHs was recorded. The data indicate a high accuracy of controlling components orientation and satisfactory clinical outcomes. Using this approach, we reduced dislocation risk and got better impingement free range of motion. Therefore, we conclude that combined anteversion is effective for DDH patients who receive a THA. This approach could guarantee stable and functioning joints for DDH patients receiving THA. [Copyright &y& Elsevier]

Abstract: This study details a method using rapid prototyping (RP) technique to assist in acetabular revision with complex bone defects. Hemi-pelvic RP models were built among 25 patients with complex acetabular bone defects. Each patient was scheduled to undergo revision using either commercially available or customized cages based on individualized RP models. Average follow-up was 4.4years (range, 1 to 9years). The average Harris hip score was 36.1 (range, 20 to 58) preoperatively and reached an average of 82.6 (range, 60–96) at the last follow-up. No mechanical failure or loosening was observed. One patient experienced hip dislocation 4days postoperatively. The resultant findings of this study merit consideration of RP as a helpful clinical complement for dealing with some complex bone defect of acetabulum. [Copyright &y& Elsevier]

Abstract: Autogenous impaction grafting was performed to improve acetabular cup coverage in 68 patients (78 hips) with developmental dysplasia of the hip (DDH) after total hip arthroplasty, and the patients were then monitored for a mean duration of 5.5years. No cup revisions were required, and there was no radiographic loosening. The host–graft interface became indistinct by 6weeks after surgery, trabecular bone formation was seen by 12weeks, and definite trabecular reorientation was seen by 20months. At the last follow-up examination, the mean cup coverage was 97.7%, whereas mean coverage by bone grafting was 27.9%. Among 12 patients with most of the bone graft placed at the absolutely protruded area of the cup, the cup coverage provided by the bone graft decreased from 95.4% immediately after surgery to 20.7% by the final follow-up examination. Bone-particle grafting can provide a satisfactory integration speed and a low incidence of displacement and ectopic ossification. [Copyright &y& Elsevier]

Abstract: Alignment parameters in 199 healthy lower extremities of Southern Chinese adults and the parameters'' anatomical influence were studied in a standardized frontal plane for the selection of the proper valgus angle of the distal femoral cut in total knee arthroplasty. The average hip-knee-ankle angle was 179.8° ± 2.4°. The average femoral physiologic valgus angle was 5.1° ± 0.9° (95% confidence interval, 4.9°-5.2°). The hip-knee-ankle angle showed a significantly inverse correlation with the femoral physiologic valgus angle. The results indicate that choosing 5° as the valgus angle for the femoral distal cut in total knee arthroplasty is safe for most of Southern Chinese ethnicity, and it is reasonable to adjust the femoral valgus angle to 7°or 3° in the few patients with severe genu varum or genu valgum. [Copyright &y& Elsevier]