Minimum 10-Year Survivorship of Uncemented Acetabular Reconstruction With Bulk Femoral Head Autografting in Crowe Type IV Developmental Hip Dysplasia.

BACKGROUND: In total hip arthroplasty (THA) for severe dislocations such as Crowe type IV developmental dysplasia of the hip (DDH), sufficient bone volume for stable fixation of the acetabular component can be achieved by placing a reinforcing bone graft prepared from the resected femoral head into the deficient acetabulum. The purpose of the current study was to examine the long-term survivorship of uncemented THA in conjunction with a bulk femoral head autograft in patients who have Crowe type IV DDH. METHODS: A total of 35 patients (42 hips) who have Crowe type IV DDH and underwent THA using uncemented cup fixation with bulk femoral head autografting were followed up for a mean period of 15.0 years (range, 10.0 to 20.0) postoperatively. Anteroposterior pelvic radiographs were used for measurements such as the horizontal coverage of the grafted bone and the center-edge angle. Kaplan-Meier survivorship analyses were performed with revision of the acetabular component as the endpoint. RESULTS: The Kaplan-Meier analysis indicated 15-year survival rates of 90.4%. The mean horizontal coverage of grafted bone was 46.1% (range, 23.7 to 66.0), and there were 16 cases with horizontal coverage of ≥ 50%. There was no difference in the appearance of a thin (< 1 mm) radiolucency line around the cup between cases with < 50% versus ≥ 50% of the horizontal coverage of grafted bone (4 versus 2 hips; P = .446). Trabecular bridging and remodeling were seen in all cases after mean periods of 4.1 and 9.0 months postoperatively, respectively. Trabecular reorientation was seen in 41 of 42 hips (97.6%) at a mean follow-up of 19.9 months. CONCLUSIONS: Acetabular reconstruction with femoral bulk bone grafting for Crowe type IV DDH resulted in high survival rates and was a good method to restore bone stock and obtain long-term fixation.

The effect of acetabular and femoral component version on dislocation in primary total hip arthroplasty.

PURPOSE: The purpose of the present study was to: (1) investigate the variation of both acetabular and femoral component version in a large series of consecutive primary THA patients, and (2) to better define the associations of acetabular and femoral component alignment and clinical factors with subsequent hip dislocation in those patients. METHODS: We analyzed CT scans of 1,555 consecutive primary THAs and measured version of the components. We also documented the frequency and direction of subsequent dislocation as well as femoral head size, posterior tissue repair, any history of previous hip surgery, and gender. RESULTS: The dislocation rate after THA was 3.22 %. The dislocation risk was 1.9 times higher if cup anteversion was not between 10° and 30°. Compared to hips that did not dislocate, those that experienced anterior dislocation had a significantly greater combined anteversion; those that dislocated posteriorly had a significantly smaller combined anteversion. Hips with previous rotational acetabular osteotomy or head size smaller than 28 mm correlated with an increased dislocation rate. CONCLUSION: The dislocation risk could be higher if cup anteversion was not between 10° and 30°. Greater combined anteversion could be a risk factor of anterior dislocation, and posterior dislocation could be more common in smaller combined anteversion.

Computed tomographic measurement of acetabular and femoral component version in total hip arthroplasty.

PURPOSE: The purposes of the present study were (1) to investigate the variation and accuracy of both acetabular and femoral component version on the axial computed tomographic (CT) images, and (2) to better define the associations between the components version and clinical factors. METHODS: We investigated acetabular and femoral component orientation in 1,411 primary total hip arthroplasties that had been performed without computer-assisted navigation. Version of the acetabular and femoral components was measured on the axial CT images. RESULTS: The component version was significantly greater than the native version in both acetabular and femoral version. There was a significant correlation between the stem and native femoral versions, but not between the acetabular component and native acetabular versions. CONCLUSION: This study identifies several features that might help analyse the effect of pre-operative native acetabular and femoral version on the variation of component alignment.

Denosumab-associated Periprosthetic Atypical Femur Fracture: A Case Report.

Introduction: Denosumab is generally used for 5-10 years to treat postmenopausal osteoporosis. Although atypical fractures caused by bisphosphonate use are well known, reports of denosumab-associated femur fractures are rare. Case Report: Herein, a 75-year-old woman suffered an atypical periprosthetic femoral fracture 31 months after receiving denosumab. The fracture occurred transverse to the stem tip with lateral cortical thickening. The patient underwent revision surgery for conversion to a longer cemented stem. The fracture site healed 10 months after revision surgery. Conclusion: As far as we know, there have been no reports of a case on periprosthetic atypical femur fracture associated with denosumab. Our study shows the potential of periprosthetic atypical femoral fractures in patients using denosumab for a long time.

Leg length change in total hip arthroplasty with subtrochanteric femoral shortening osteotomy for Crowe type IV developmental hip dysplasia.

Primary total hip arthroplasties were performed in 70 hips for the treatment of Crowe type IV developmental dysplasia of the hip. The patients were subdivided into 2 groups with or without iliofemoral osteoarthritis. Leg length change was measured radiographically. Preoperative hip motion was reviewed from medical records and defined as either higher or lower motion groups. The leg length change in patients without iliofemoral osteoarthritis was significantly greater than that in patients with iliofemoral osteoarthritis, and the higher hip motion group had greater leg length change in total hip arthroplasty than the lower motion group. The current study identifies several features that might help predict leg length change during the preoperative planning of total hip arthroplasty for Crowe type IV developmental hip dysplasia.

Anterior knee pain after total hip arthroplasty in developmental dysplasia.

Little has been reported on knee pain after total hip arthroplasty (THA). The purpose of this study was to investigate the incidence and mechanism of knee pain after THA. Two hundred fifty-two patients with hip dysplasia were clinically and radiographically assessed for knee pain before and after THA. Incidences of knee pain and patellofemoral alignment were analyzed with reference to postoperative change in leg length, femoral anteversion, and the femoral offset. Anterior knee pain was present in 16 patients (7.3%). Lateral patellar tilt was increased in all patients with knee pain and significantly larger compared to that seen in patients without knee pain. The increased patellar tilt disappeared within 3 months, but symptoms in 4 patients persisted for more than 3 months. The patellar tilt was significantly related to the amount of leg lengthening. This study demonstrates that THA influences the patellofemoral joint via leg lengthening and causes anterior knee pain.

Relationship between Perceived Leg Length Discrepancy at One Month and Preoperative Hip Abductor Muscle Elasticity in Patients after Total Hip Arthroplasty.

OBJECTIVE: Preoperative factors related to perceived leg length discrepancy (PLLD) after total hip arthroplasty (THA) are not well studied. This study aimed to examine the preoperative factors, including hip abductor modulus, related to PLLD one month after THA. METHODS: The study included 73 patients diagnosed with osteoarthritis secondary to developmental dysplasia of the hip and a posterior approach to surgery. Multiple logistic regression analysis was performed using the presence or absence of PLLD as the dependent variable and preoperative hip abductor's modulus of elasticity, pain, hip abduction range of motion, hip abductor muscle strength and pelvic obliquity as the independent variable. Additionally, receiver operating characteristic curves were used for the extracted variables for calculating the cutoffs, sensitivity, specificity and area under the curve (AUC) to determine the presence or absence of PLLD. The significance level was set at p<0.05. RESULTS: The hip abductor modulus (odds ratio=1.13; 95% confidence interval=1.06-1.21; p<0.001) was selected as a preoperative factor. The cutoff value to determine the presence or absence of a PLLD was 16.32 kPa. The sensitivity and specificity were 81.8% and 72.5%, respectively, and the AUC was 0.8137. CONCLUSION: The hip abductor muscle elastic modulus affected PLLD one month after THA. If the preoperative hip abductor elastic modulus is higher than the cutoff value, it may affect the appearance of PLLD at one month postoperatively.

Clinical accuracy of cervical pedicle screw insertion using lateral fluoroscopy: a radiographic analysis of the learning curve.

Cervical pedicle screw is thought to be the most stable instrumentation for reconstructive surgery of the cervical spine. However, because of the unresolved and inherent risk of neurovascular injuries due to screw perforation, it remains not widespread nowadays despite the excellent biomechanical property. Fifty-two consecutive cases having undergone spinal reconstruction using cervical pedicle screw were investigated. There were 24 females and 28 males. The mean follow-up period was 53 months. Those patients were stratified into three groups according to the period of screw insertion. A total of 280 screws were inserted. Ninety-two screws in 19 cases, 100 screws in 18 cases and 88 screws in 15 cases were inserted in the earlier, the middle and the later periods, respectively. Clinical results including complications were recorded in all cases. Screw perforations were evaluated in both plain X-ray and CT. Screw perforations occurred in 11 (12.0%), 7 (7.0%) and 1 (1.1%) screws in each period. There were no complications, such as infection, neurological deterioration and neurovascular injury directly related to screw insertion. The learning curve showed a significant improvement especially in the later period. However, the perforation rates in both the earlier and middle periods must not be underestimated. Surgeons with less experience must insert cervical pedicle screws with the assistance of a senior surgeon to avoid lethal complications.

Reliability of measurements of hip abduction strength obtained with a hand-held dynamometer.

This study aimed to evaluate intrarater and interrater reliability when measuring hip abductor strength in the supine position using a hand-held dynamometer (HHD) (Study 1), and to elucidate the relationships between measured values and examiners' physical characteristics (Study 2). Three healthy examiners (1 female, 24 y.o. and 2 males 23 and 27 y.o) and 12 subjects (6 females, 24.5 ± 2.8 years and 6 males, 27.7 ± 3.5 years) participated in Study 1, and 20 healthy examiners (7 females, 22.3 ± 1.3 years and 13 males, 29.4 ± 8.2 years) and 2 subjects (1 female, 24 y.o. and 1 male 27 y.o) participated in Study 2. All healthy examiners were hospital employees. Hip abductor strength was measured by HHD with hand fixation and with belt fixation, and examiner age, sex, height, weight, BMI, and dominant hand grip strength were evaluated. The intraclass correlation coefficient (ICC) (1,1), a measure of intrarater reliability, was 0.89-0.95 with hand fixation and 0.96-0.97 with belt fixation. ICC (2,1), a measure of interrater reliability, was 0.76-0.79 and 0.90-0.93, respectively. In subjects with high muscle strength (the examiner's hand was moved), the examiner's dominant hand grip strength affected muscle strength values with hand fixation (standardized partial regression coefficient = 0.78, determination coefficient R(2 )= 0.61, p < 0.01). In subjects with low muscle strength (the examiner's hand was not moved), no variables had effect. When the muscle strength of the subject is weak, both methods can be used. When the muscle strength of the subject is strong, it is necessary to adjust the value obtained by the examiner's dominant hand grip strength in the hand fixation method.

Using the transverse acetabular ligament as a landmark for acetabular anteversion: an intra-operative measurement.

PURPOSE. To measure the transverse acetabular ligament (TAL) anteversion in hips with severe deformity, using fluoroscopy-computed tomographic navigation. METHODS. 31 hips in 10 men and 19 women aged 40 to 78 (mean, 58.7) years who underwent total hip arthroplasty for primary osteoarthritis (n=6) or osteoarthritis secondary to developmental hip dysplasia (n=19) or congenital hip dislocation (n=6) were included. The severity of hip dislocation was classified according to the Crowe classification; 15 hips were grade 1, 7 were grade 2, 3 were grade 3, and 6 were grade 4. The TAL anteversion was measured using fluoroscopy-computed tomographic navigation. The difference in TAL anteversion between non-dislocated hips (Crowe grade 1, n=15) and dislocated hips (Crowe grades 2-4, n=16) was compared. RESULTS. In all 31 hips, the TAL could be visualised intra-operatively. No patient reported severe pain, early wear, loosening, or dislocation after 2 years. The mean TAL anteversion and inclination angles measured by the navigation system were 26.5 (SD, 8.9; range, 8-42) degrees and 41.5 (SD, 4.6; range, 32-49) degrees, respectively. 22 of the 31 hips were in the safe zone. TAL anteversion in non-dislocated and dislocated hips was not significantly different. Inter- and intra-observer mean absolute differences in TAL anteversion were 0.3 and 0.4 degree, respectively. CONCLUSION. The TAL is a useful anatomic landmark for total hip arthroplasty in dislocated hips.

Evaluation of preoperative hip range of motion under general anaesthesia.

Hip range of motion (ROM) may be an important preoperative variable, however, measurement of hip ROM can be affected by various factors. The purposes of this study were to compare conventional preoperative ROM measurements with those measurements obtained under general anaesthesia, and to better define the associations between preoperative hip ROM, and demographic, functional, and diagnostic variables.
Conventional preoperative hip ROM and ROM under general anaesthesia were prospectively measured in 471 hips. Harris pain score, the Crowe classification, and the diagnosis were also investigated. 
The hip ROM in all directions under general anaesthesia was significantly greater than conventional preoperative hip ROM. There were correlations between conventional preoperative hip ROM and the Harris hip pain score. Hip ROM with Crowe type I deformity under anaesthesia was significantly greater than in hips with type II, III or IV. ROM under anaesthesia of osteonecrosis hips was significantly greater than osteoarthritis and dislocated hips. Conventional preoperative ROM in men was greater in flexion and external rotation compared to women. Internal rotation motion in women in both conventional preoperative ROM and ROM under anaesthesia was greater than in men. 
Hip pain, Crowe classification and diagnosis could influence preoperative hip ROM. Measurement of hip ROM under general anaesthesia could better reflect true ROM compared to measurement without anaesthesia.

Predicting leg-length change after total hip arthroplasty by measuring preoperative hip flexion under general anaesthesia.

PURPOSE: To measure preoperative hip flexion under general anaesthesia in patients with developmental dysplasia of the hip and analyse its correlation with leg-length change. METHODS: 79 women and 6 men aged 27 to 82 (mean, 59) years underwent 92 total hip arthroplasties for severe developmental dysplasia of the hip of Crowe types II (n=60), III (n=17), and IV (n=15). All such patients had severe pain and/or considerable difficulty in walking and performing daily activities. 16 of the hips were treated with transverse subtrochanteric shortening osteotomy, whereas the remaining 76 had no femoral osteotomy. Preoperative passive hip flexion was measured under general anaesthesia with a goniometer by a single investigator. Its mean value in patients with Crowe type-III deformity was 60.3º. Therefore, >60º of flexion was defined as high. Postoperative leg-length change was measured radiographically. The distraction of the greater trochanter was equal to the leg-length change in patients treated without femoral osteotomy, whereas leg-length change was calculated by subtracting the amount of resection of the femur from the distraction of the greater trochanter in patients treated with femoral osteotomy. RESULTS: Of the 16 hips treated with a transverse subtrochanteric shortening femoral osteotomy, 2, 2, and 12 were Crowe types II, III, and IV, respectively. In these 16 hips, hip flexion was high in 10 (mean, 86º) and low in 6 (mean, 36º). Leg-length change was significantly greater in the high than low flexion groups (31 vs. 13 mm, p<0.01). In the 76 hips without osteotomy, hip flexion was high in 54 (mean, 85º) and low in 22 (mean, 40º). Leg-length change was significantly greater in the high than low flexion groups (25 vs. 19 mm, p=0.016). Preoperative hip flexion under general anaesthesia correlated with leg-length change in hips with osteotomy (r=0.850, p=0.0002) and without osteotomy (r=0.267, p=0.019). CONCLUSION: Preoperative hip flexion measured under general anaesthesia may predict leg-length change after THA.

Spinopelvic alignment in patients with osteoarthrosis of the hip: a radiographic comparison to patients with low back pain.

STUDY DESIGN: A retrospective, age- and sex-matched radiographic study. OBJECTIVES: To investigate the spinopelvic alignment in patients with osteoarthosis of the hip (HOA) and those with low back pain (LBP) and to determine the characteristics and differences in both groups. SUMMARY OF BACKGROUND DATA: Hip-spine syndrome, first described by Offierski and MacNab, is quite an important pathology when treating patients with pain in their low back and lower extremities. However, despite it being a well-known entity, few papers have adequately investigated and assessed the spinopelvic alignment in patients with hip-spine syndrome. METHODS: Sagittal and coronal spinopelvic alignments were investigated in 150 patients with HOA and 150 with LBP using radiographs of the whole spine in both anteroposterior and lateral views. Parameters measured in this study were lumbar lordosis (LL), sacral slope (SS), the shift of the sagittal C7 plumb line, pelvic incidence (PI), and pelvic tilt (PT) on the lateral radiographs. On the anteroposterior (AP) films, lumbar scoliosis, pelvic obliquity, leg length discrepancy, the shift of the coronal C7 plumb line, and Sharp angle were measured. These parameters were compared between the two groups. In patients with HOA, the relationships between Sharp angle and other parameters were also analyzed to clarify the possible influence of sagittal and coronal spinopelvic alignments on HOA without acetabular dysplasia. RESULTS: LL, SS, PI, and PO were found to be less in patients with LBP compared with those with HOA, and there was no significant difference in LS between the two groups. PI was significantly greater in HOA patients and strongly correlated to PT, SS, and LL (i.e., as the PI increased so did the PT, SS, and LL). Sharp angles were also significantly greater in HOA patients and strongly correlated to age, LL and SS (i.e., as Sharp angles increased so did LL and SS); however, age decreased in the hip patients. CONCLUSIONS: These findings suggest that higher PI in the younger individual may contribute to the development of HOA in later life without both lumbar kyphosis and acetabular dysplasia because of the anterior uncovering of the acetabulum. More investigation will be expected to analyze the spinopelvic alignment in patients with hip spine syndrome.