Total hip arthroplasty improves systemic muscle atrophy in patients with hip osteoarthritis.

BACKGROUND: To investigate muscle volume changes in all body regions after total hip arthroplasty (THA) with dual-energy X-ray absorptiometry (DEXA), and determine the positive effects of THA for systemic muscle atrophy in patients with hip osteoarthritis (HOA). METHODS: In total, 116 patients with a mean age of 65.8 (45-84) years who had undergone THA for unilateral HOA were included in this study. DEXA scans were performed serially at 2 weeks, 3, 6, 12, 18, and 24 months after THA. The normalized height squared muscle volume (NMV) and the change ratio of NMV (ΔNMV) were calculated independently for operated lower extremity (LE), non-operated LE, both upper extremities (UEs), and trunk. Skeletal mass index, which is a sum of NMV of both LEs and UEs, was evaluated at 2 weeks and 24 months after THA to identify systemic muscle atrophy equivalent to the diagnostic criteria of sarcopenia. RESULTS: ΔNMVs in non-operated LE, both UEs, and trunk increased gradually up to 6, 12, and 24 months after THA, although that in operated LE did not increase during a 24-month period. The ΔNMVs in operated LE, non-operated LE, both UEs, and trunk at 24 months after THA were +0.6%, +7.1%, +4.0%, and +4.0%, respectively (P = 0.993, P < 0.001, P < 0.001, P = 0.012). The proportion of systemic muscle atrophy significantly decreased from 2 weeks (38%) to 24 months (23%) after THA (P = 0.022). CONCLUSIONS: THA can potentially have secondary positive effects for systemic muscle atrophy exception of operated LE.

Idiopathic normal pressure hydrocephalus possibly affects the occurrence of proximal femoral fracture.

AIMS: The clinical triad of idiopathic normal pressure hydrocephalus (iNPH) includes gait disturbance, dementia, and urinary incontinence. These symptoms are also frequently observed in patients with proximal femoral fracture (PFF). The aim of this study was to investigate the relationship between PFF and iNPH retrospectively. PATIENTS AND METHODS: Of the130 patients over 80-years-old with PFF included in this study, 48 were assigned to the PFF group. Forty-eight patients with peripheral vertigo matched with the PFF group for age and sex were included in the control group. We compared the Evans' index (EI), which is a head computed tomography finding of iNPH, and the percentages of patients with EI>0.3 between the two groups. The PFF group was further divided into two subgroups depending on whether EI was higher or lower than 0.3 (the higher or lower subgroup, respectively). We compared the patient's gait abilities before PFF, causes of PFF, cognitive functions, and occurrence of urinary incontinence between both groups. RESULTS: The mean value of EI in the PFF group was significantly higher than that in the control group (PFF group, 0.301; control group, 0.284; p=0.008). The percentages of patients with EI>0.3 in the PFF and control groups were 62.5% and 35.4%, respectively (p=0.014). In subgroup analyses, the gait ability before injury was worse in the higher subgroup than that in the lower subgroup and was prominent among individuals who could walk only with human assistance (p=0.018). There were no significant differences in other parameters. CONCLUSION: Elderly patients with PFF may have underlying idiopathic normal pressure hydrocephalus. LEVEL OF EVIDENCE: III; case-control comparative study.

Usefulness of nutritional assessment using Geriatric Nutritional Risk Index as an independent predictor of 30-day mortality after hip fracture surgery.

INTRODUCTION: The Geriatric Nutritional Risk Index (GNRI) is an objective nutritional status assessment tool used for predicting mortality risk in hospitalized patients. However, it is unclear whether GNRI reflects short-term mortality for hip fracture patients after surgery. We examined the usefulness of the nutritional status assessed by the GNRI and identified cutoff scores that predict mortality risk. Does GNRI on admission predict the mortality after surgery for hip fracture? HYPOTHESIS: Evaluation of GNRI could help identify patients at higher risk of 30-day mortality after hip fracture surgery. MATERIALS AND METHODS: This retrospective study used data from 1040 patients who underwent hip fracture surgery. Fatalities within 30 days after hip fracture surgery were investigated. The GNRI was calculated on admission in all patients as follows: 14.89×serum albumin (g/dL)+41.7×body mass index/22. Receiver operating characteristic (ROC) curves were used to calculate the area under the curve (AUC) and the optimal cutoff score that could predict 30-day mortality after hip fracture surgery. This cutoff score was used for comparing the mortality rates between patient groups with a GNRI higher and lower than the cutoff score using Fisher's exact test. Logistic regression analysis was used to determine risk factors of 30-day mortality. RESULTS: There were 17 fatalities (1.6%) in the cohort. The ROC-AUC value was 0.811, and the cutoff GNRI was 75.4. Mortality was significantly higher in the group with a GNRI<75.4 compared with the group with a GNRI≥75.4 (odds ratio [OR], 22.99; 95% confidence interval [95% CI], 7.55-78.05; p=0.00000004). A GNRI<75.4 was a significant predictor of mortality within 30-days after hip fracture surgery (OR, 27.1; 95% CI, 8.57-85.9; p≤0.0001). DISCUSSION: Our results show that nutritional status assessment using GNRI can help predict 30-day mortality among geriatric patients undergoing surgery for hip fracture. The GNRI is a simple and accurate tool for predicting the risk of mortality after hip fracture surgery. LEVEL OF EVIDENCE: IV; case series study.

Short-range UV-LED irradiation in postmenopausal osteoporosis using ovariectomized mice.

Postmenopausal osteoporosis is crucial condition that reduces the QOL of affected patients just like aged type osteoporosis. The aim of this study was to evaluate the effectiveness of short-range UV-LED irradiation in postmenopausal osteoporosis using ovariectomized mice. Preliminary experiments identified the time of onset of osteoporosis after ovariectomy (8 weeks) in our model. We have set up a total of 4 groups (n = 8/group); vitamin D-repletion with UV irradiation (Vit.D+UV+), vitamin D-repletion without UV irradiation (Vit.D+UV-), vitamin D-deficiency with UV irradiation (Vit.D-UV+), vitamin D-deficiency without UV irradiation (Vit.D-UV-), and. From 8 weeks after ovariectomy, UV was irradiated for 24 weeks. At the time of 16 and 24 weeks' irradiation, serum Vit.D levels, various markers of bone metabolism, bone mineral density, and bone strength were evaluated, and histological analyses were performed. In addition, muscle strength was analyzed. Serum 25-hydroxyvitamin D [25 (OH) D] levels at 40 and 48 weeks of age were increased in the Vit.D-UV+ group compared to the Vit.D-UV-group. Cortical thickness evaluated with micro-CT and strength of bone were significantly higher in Vit.D-UV+ group than those in Vit.D-UV- group. There was no difference in muscle strength between Vit.D-UV+ group and Vit.D-UV- group. No obvious adverse effects were observed in UV-irradiated mice including skin findings. Short-range UV irradiation may ameliorate postmenopausal osteoporosis associated with a state of vitamin D deficiency.

Changes in blood pressure during cemented hemiarthroplasty for hip fracture in elderly patients under spinal anaesthesia.

Blood pressure changes around cement insertion during total hip arthroplasty have been investigated; however, there is little agreement regarding whether a similar phenomenon occurs during hemiarthroplasty in the elderly under spinal anaesthesia. Therefore, our objective was to examine blood pressure around cement insertion during hemiarthroplasty in the elderly. For this retrospective, single-centre, case series study, we identified 430 hips of patients aged >65 years who underwent cemented hemiarthroplasty under spinal anaesthesia from January 2010 to August 2018. The maximum regulation ratio (MRR) was used to express changes in blood pressure immediately after cement insertion and was calculated as follows: the greatest difference (positive or negative) during 5 min after cement insertion into the bone canal divided by systolic blood pressure just before cement insertion. The timings of vasopressor administration and blood transfusion were recorded. The median MRR was compared for each American Society of Anesthesiologists (ASA) classification. The mean MRR was 4.0% (SD:10.4; range -26 to 83). MRR of patients with a >10% increase in blood pressure was significantly less than that of patients with a <10% change in blood pressure. Vasopressor was used in three patients 10 min after cement insertion into the bone canal. There was no significant difference between MRR groups and ASA classification (p = 0.182, respectively). MRR was not significantly different for each ASA classification. However, few cases showed a reduction in blood pressure immediately after cement insertion, regardless of ASA classification.

Dynamic changes in longitudinal stretching of the spinal cord in thoracic spine: Focus on the spinal cord occupation rate of dural sac.

OBJECTIVES: This study aimed to evaluate the anteroposterior diameters and cross-sectional areas of the dural sac and spinal cord in the thoracic spine, to elucidate the spinal cord occupation rate of the dural sac in these dynamic changes for each level using multidetector-row computed tomography (MDCT). PATIENTS AND METHODS: Fifty patients with cervical or lumbar spinal disease were prospectively enrolled. After preoperative myelography, MDCT was performed at maximum passive flexion and extension. The anteroposterior diameter and cross-sectional area of the dural sac and spinal cord in the axial plane and the thoracic spinal cord length in the sagittal plane were measured. The spinal cord occupation rate in the dural sac was calculated. RESULTS: The spinal cord occupation rate of the dural sac in anteroposterior diameter was lower on flexion than on extension, with significant differences from the T1/T2 to T11/T12 levels (p < 0.0001). The spinal cord occupation rate of the dural sac in cross-sectional area was lower on flexion than on extension, with significant differences except from T3/T4 to T6/T7 levels (p < 0.01). There was a bimodal increase in the occupation rate with elevations at the cervicothoracic junction and thoracolumbar junction. The thoracic spinal cord length on flexion was significantly longer than that on extension (p < 0.0001). CONCLUSIONS: The spinal cord occupation rate of the dural sac was lower on flexion than on extension, despite thoracic spine being considered a rigid region. The dynamic changes in longitudinal stretching and shrinkage of the spinal cord affected the occupation rate.

Low energy irradiation of narrow-range UV-LED prevents osteosarcopenia associated with vitamin D deficiency in senescence-accelerated mouse prone 6.

Deficiency of vitamin D is an important cause of osteosarcopenia. The purpose of this study is to examine the effects of low energy narrow-range UV-LED on osteosarcopenia in animal models of senescence-accelerated mouse prone 6 (SAMP6). Preliminary experiments specified the minimum irradiance intensity and dose efficacy for vitamin D production (316 nm, 0.16 mW/cm2, 1,000 J/m2). we set a total of 4 groups (n = 8 per group); vitamin D-repletion without UV irradiation (Vit.D+UV-), vitamin D-repletion with UV irradiation (Vit.D+UV +), vitamin D-deficiency without UV irradiation, (Vit.D-UV-), and vitamin D-deficiency with UV irradiation (Vit.D-UV +). Serum levels of 25(OH)D at 28 and 36 weeks of age were increased in Vit.D-UV+ group as compared with Vit.D-UV- group. Trabecular bone mineral density on micro-CT was higher in Vit.D-UV+ group than in Vit.D-UV- group at 36 weeks of age. In the histological assay, fewer osteoclasts were observed in Vit.D-UV+ group than in Vit.D-UV- group. Grip strength and muscle mass were higher in Vit.D-UV+ group than in Vit.D-UV- group at 36 weeks of age. Signs of severe damage induced by UV irradiation was not found in skin histology. Low energy narrow-range UV irradiation may improve osteosarcopenia associated with vitamin D deficiency in SAMP6.

Reoperation for Late Neurological Deterioration After Laminoplasty in Individuals With Degenerative Cervical Myelopathy: Comparison of Cases of Cervical Spondylosis and Ossification of the Posterior Longitudinal Ligament.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The objective of this study was to elucidate the rate and causes of reoperation for late neurological deterioration after cervical laminoplasty by comparing cases of cervical spondylotic myelopathy (CSM) with those of ossification of the posterior longitudinal ligament (OPLL). SUMMARY OF BACKGROUND DATA: Although the long-term surgical outcomes of cervical laminoplasty in patients with CSM or OPLL are satisfactory, reoperation is sometimes required for late neurological deterioration after laminoplasty. However, limited information is available about long-term follow-up in such cases. METHODS: This retrospective cohort study included 623 patients who underwent cervical laminoplasty for cervical myelopathy (average follow-up duration, 6.1 [range, 2-15] years). The rate of reoperations for late neurological deterioration (>6 mo after the initial surgery) was investigated. RESULTS: Primary diagnoses were CSM and OPLL in 522 (83.8%) and 101 (16.2%) patients, respectively. During the follow-up period, 10 (1.6%) patients required reoperation: 7 (1.3%) in the CSM group and 3 (3.0%) in the OPLL group. No significant difference was found between the CSM and OPLL groups regarding patients requiring reoperation (P = 0.26). The mean elapsed time between primary surgery and reoperation was 4.7 ±â€Š3.2 and 10.0 ±â€Š5.7 years in the CSM and OPLL groups, respectively. The predicted risk percentages of reoperation at 10 years after primary surgery were 2.9% and 1.0% in the CSM and OPLL group, respectively. The causes of reoperation for CSM were C5 palsy in five, severe radiculopathy in one, and restenosis due to instability after laminoplasty in one case; the cause of reoperation for OPLL was enlargement of ossification in all three cases. CONCLUSION: Although the clinical outcomes of laminoplasty were favorable in most patients, reoperation for late neurological deterioration was required in approximately 1.0% to 3.0% of CSM and OPLL cases within 10 years after laminoplasty. LEVEL OF EVIDENCE: 4.

Effects of ultraviolet irradiation with a LED device on bone metabolism associated with vitamin D deficiency in senescence-accelerated mouse P6.

AIMS: This study investigated effects of narrow-range ultraviolet irradiation (UVR) by a new UV-LED device on vitamin D supply and changes of bone in senescence-accelerated mouse P6 (SAMP6) with vitamin D deficiency. MAIN METHODS: We used female SAMP6 mice as a senile osteoporotic model. We set a total of 3 groups (n = 4 per group); D-UVR+ group (vitamin D deficient-dietary and UVR), D- (vitamin D deficient-dietary), and D+ groups (vitamin D contained-dietary). Mice in the D-UVR + group were UV-irradiated (305nm) with 1 kJ/m2 twice a week for 12 weeks from 20 to 32 weeks of age. Serum 25(OH)D, 1,25(OH)2D, and micro-computed tomography (CT) were assessed over time. Mechanical test, and histological assay were performed for femurs removed at 32 weeks of age. KEY FINDINGS: UVR increased both serum 25(OH)D and 1,25(OH)2D levels at 4 and 8 weeks-UVR in the D-UVR+ group compared with that in the D- group (P < 0.05, respectively). Relative levels of trabecular bone mineral density in micro-CT were higher in the D-UVR+ group than in the D- group at 8 weeks-UVR (P = 0.048). The ultimate load was significantly higher in the D-UVR+ group than in the D- group (P = 0.036). In histological assay, fewer osteoclasts and less immature bone (/mature bone) could be observed in the D-UVR+ group than in the D- group, significantly. SIGNIFICANCE: UVR may have possibility to improve bone metabolism associated with vitamin D deficiency in SAMP6 mice.

The effects of patient characteristics and stem alignment on distal femoral cortical hypertrophy after cemented polished tapered stem implantation.

BACKGROUND: The objective of this study was to evaluate the results of over 10 years of total hip arthroplasty (THA) practice with ExeterTM stems and the clinical relevance of distal femoral cortical hypertrophy (DFCH). METHODS: We retrospectively reviewed 127 hips (120 patients) that had undergone THA with ExeterTM stems between 2004 and 2007. Kaplan-Meier survival analyses for the stem of all 127 hips were performed using different endpoints. Of 127 hips, 100 (94 patients) had complete 10-year follow-up data, including the Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ) as the patient-reported outcomes, and the clinical relevance of DFCH was analyzed using multivariable logistic regression analysis. RESULTS: The survival of the stem with the endpoint of re-operation for loosening, > 5-mm subsidence, and re-operation for any reason were 100%, 99.1% (95% CI 97.5-100%), and 98.3% (95% CI 96.0-100%), respectively. Of 100 hips followed completely for 10 years, DFCH occurred in 20 hips (20%). The satisfaction and pain visual analog scale of JHEQ revealed high satisfaction and less pain in patients with DFCH. By multivariate logistic regression analysis, body weight > 55 kg (odds ratio: 2.88, p = 0.035) and varus stem alignment (odds ratio: 6.56, p = 0.003) were found to be predictors for DFCH. CONCLUSIONS: The incidence of DFCH with the ExeterTM stem was 20%. A body weight > 55 kg and varus stem alignment are predictors for future DFCH. DFCH with the ExeterTM stem indicates a good outcome with less hip pain.

Comparison of Wear Rate between Ceramic-on-Ceramic, Metal on Highly Cross-linked Polyethylene, and Metal-on-Metal Bearings.

Objective Currently, there is a lack of evidence on the medium-term follow-up of cementless total hip arthroplasty (THA) using metal on highly cross-linked polyethylene (MoP), ceramic-on-ceramic (CoC), and metal-on-metal (MoM) bearings. Our aim was to calculate the 5- to 10-year wear rate and the incidence rate of osteolysis for 3 types of bearings. Methods A total of 77 patients underwent MoP, 105 underwent ceramic CoC, and 55 underwent MoM THAs. The average patient age at the time of surgery was 64.7, 55.9, and 59.9 years old in the MoP, CoC, and MoM bearings, respectively. Clinical and radiologic measurements at a mean follow-up of 7.6 years were analyzed. Results The mean postoperative Harris hip scores showed no difference among the groups. The mean annual liner wear rates were 0.0160, 0.0040 and 0.0054 mm/year in MoP, CoC bearings, and MoM bearings, with that of CoC bearings being significantly lower than the others. Osteolysis (14.5%) among MoM bearings was significantly more frequently observed compared with the others. Kaplan-Meier survival at 10 years with implant loosening, or revision THA as the endpoint, was 96.1% (95% confidence interval [CI]: 88.4-98.7) for MoP, 98.6% (95% CI: 90.3-98.6) for CoC bearing, and 98.2% (95% CI: 88.0-99.7) for MoM bearings ( p = 0.360). Conclusion Excellent clinical and radiological outcomes were obtained for MoP and CoC bearings.

Comparison of Wear Rate between Ceramic-on- Ceramic, Metal on Highly Cross-linked Polyethylene, and Metal-on-Metal Bearings / Comparação da taxa de desgaste entre componentes de cerâmica sobre cerâmica, de metal sobre polietileno de alta ligação cruzada e de metal sobre metal

Abstract Objective Currently, there is a lack of evidence on the medium-term follow-up of cementless total hip arthroplasty (THA) using metal on highly cross-linked polyethylene (MoP), ceramic-on-ceramic (CoC), and metal-on-metal (MoM) bearings. Our aim was to calculate the 5- to 10-year wear rate and the incidence rate of osteolysis for 3 types of bearings. Methods A total of 77 patients underwent MoP, 105 underwent ceramic CoC, and 55 underwent MoM THAs. The average patient age at the time of surgery was 64.7, 55.9, and 59.9 years old in the MoP, CoC, and MoM bearings, respectively. Clinical and radiologic measurements at a mean follow-up of 7.6 years were analyzed. Results The mean postoperative Harris hip scores showed no difference among the groups. The mean annual liner wear rates were 0.0160, 0.0040 and 0.0054 mm/year in MoP, CoC bearings, and MoM bearings, with that of CoC bearings being significantly lower than the others. Osteolysis (14.5%) among MoM bearings was significantly more frequently observed compared with the others. Kaplan-Meier survival at 10 years with implant loosening, or revisionTHA as the endpoint, was 96.1% (95% confidence interval [CI]: 88.4-98.7) forMoP, 98.6% (95% CI: 90.3-98.6) for CoC bearing, and 98.2% (95% CI: 88.0-99.7) for MoM bearings (p = 0.360). Conclusion Excellent clinical and radiological outcomes were obtained for MoP and CoC bearings.

Resumo Objetivo Hoje, não há evidências sobre o acompanhamento em médio prazo da artroplastia total do quadril (ATQ) não cimentada com componentes de polietileno de alta ligação cruzada (highly cross-linked) sobre metal (MoP, na sigla em inglês), de cerâmica sobre cerâmica (CoC, na sigla em inglês), e de metal sobre metal (MoM, na sigla eminglês). Nosso objetivo foi calcular a taxa de desgaste entre 5 a 10 anos e a taxa de incidência de osteólise nos 3 tipos de componentes. Métodos Um total de 77 pacientes foram submetidos a ATQ com componentes de MoP; 105 foram submetidos ao mesmo procedimento com componentes de CoC, e 55 foram submetidos à ATQ com componentes de MoM. A média de idade dos pacientes no momento da cirurgia foi de 64,7, 55,9 e 59,9 anos nos grupos de componentes MoP, de CoC, e de MoM, respectivamente. Asmedidas clínicas e radiológicas emumperíodo médio de acompanhamento de 7,6 anos foram analisadas. Resultados As pontuações médias de Harris no período pós-operatório não mostraram diferença entre os grupos. As taxas médias anuais de desgaste do revestimento foram de 0,0160, 0,0040 e 0,0054 mm/ano em componentes de MoP, de CoC, e de MoP, respectivamente; a taxa de desgaste dos componentes de CoC foi significativamente menor do que as dos demais. A osteólise (14,5%) nos componentes de MoM foi significativamente mais frequente em comparação aos demais. A sobrevida de Kaplan- Meier aos 10 anos comafrouxamento do implante ou revisão da ATQ como desfecho foi de 96,1% (intervalo de confiança [IC] de 95%: 88,4-98,7) nos componentes de MoP, de 98,6% (IC95%: 90,3-98,6) nos componentes de CoC, e de 98,2% (IC95%: 88,0-99,7) nos componentes de MoM (p = 0,360). Conclusão Os resultados clínicos e radiológicos de componentes de MoP e de CoC foram excelentes.

Acetabular fracture non-union with pelvic discontinuity treated with two-stage total hip arthroplasty after intra- and extra-articular plate fixation.

Surgical intervention for the treatment of acetabular fracture non-union is often challenging. Here, we present a case of acetabular fracture non-union with pelvic discontinuity in a patient who underwent cemented total hip arthroplasty (THA) after intra- and extra-articular plate fixation. The case was a 70-year-old male with left T-shaped acetabular fracture non-union neglected for 5 months after the injury. The anterior and posterior columns were not healed, and the articular surface was displaced toward the medial side with a protrusion of the collapsed femoral head. As the first surgical intervention, we performed intra- and extra-articular plate fixation after femoral head decapitation. We fixed non-union regions from the inferior acetabular margin to the anterior column using a pelvic reconstruction plate bent three-dimensionally at the acetabular curvature on the intra-articular side. Furthermore, we fixed that of the posterior column on the outside of the acetabulum using a bent pelvic reconstruction plate. Union of the anterior and posterior columns was observed at 4 and 6 months after the first surgical intervention. At 7 months, we performed a cemented THA without additional bone grafting. At 1-year follow-up, the patient did not have left coxalgia and could walk without any gait supports. Based on our experience, we propose this surgical protocol as a useful treatment option for cases of acetabular fracture non-union.

Peri-prosthetic bone remodeling and change in bone mineral density in the femur after cemented polished tapered stem implantation.

OBJECTIVE: We examined longitudinal changes in bone mineral density (BMD) around the femur for 5 years after total hip arthroplasty (THA) using cemented collarless polished double-tapered stem implantation and investigated the influence of BMD changes on radiological remodeling of the femur. MATERIALS AND METHODS: Sixty hips from 56 patients who underwent cemented THA with a collarless polished double-tapered stem were included. BMD was measured 2 weeks postoperatively (baseline), 3 months, 6 months, 1 year and annually thereafter until 5 years after surgery using dual-energy X-ray absorptiometry on the lumbar spine and proximal femur of the operated side according to the Gruen's zone classification. We analyzed predictable factors for BMD preservation in the proximal femur and compared radiological remodeling of the femur and changes in BMD. RESULTS: BMD at 5 years in zone 7 decreased less than 10%, whereas BMD in zone 1 increased to over the baseline (+ 1.9%). Multiple linear regression analyses revealed that body weight was a predictor for positive BMD change in the proximal femur. The frequency of radiolucency of the femur was significantly lower in patients who exhibited an increase in BMD at 5 years compared with BMD at 2 weeks in zone 7. CONCLUSION: BMD preservation of the proximal femur after cemented collarless polished double-tapered stem implantation was more effective in heavier patients. Furthermore, the frequency of radiolucency around the stem was significantly lower in patients who exceeded 100% of the baseline BMD in zone 7 at 5 years.

32-mm ceramic-on-ceramic total hip arthroplasty versus 28-mm ceramic bearings: 5- to 15-year follow-up study.

INTRODUCTION:: This study aimed to compare the clinical and radiographic results of 28-mm ceramic-on-ceramic (CoC) total hip arthroplasty (THA) to those of 32-mm CoC during a 5- to 15-year follow-up period. METHODS:: 107 joints (95 women and 6 men) underwent 28-mm CoC, and 60 (49 women and 7 men) underwent 32-mm CoC. The average patient age at the time of surgery was 56.1 and 55.7 years in the 28-mm and 32-mm CoC groups, respectively. Clinical and radiologic measurements of all patients were analysed. RESULTS:: The mean preoperative Harris hip score (HHS) was similar in the 2 groups (28-mm, 58.9; and 32-mm, 58.5). However, at final follow-up, the mean HHS of the 32-mm CoC (91.8) was significantly better than that of the 28-mm CoC (88.2) ( p = 0.003), as were the ranges of motion (ROM) for flexion (98.3 ± 13.5° vs. 87.3 ± 19.3°, p < 0.001) and abduction (27.8 ± 14.9° vs. 22.1 ± 19.3°, p = 0.007). The mean wear rate was 0.0044 mm/year for the 28-mm CoC and 0.0044 mm/year for the 32-mm CoC. No ceramic fractures were found in the 2 groups. One joint in the 28-mm CoC (0.9%) required revision owing to progressive osteolysis. Kaplan-Meier survival at 10 years, with implant loosening or revision THA as the endpoint, was 98.3% for 28-mm CoC and 100% for 32-mm CoC ( p = 0.465). CONCLUSION:: There was no significant difference in ceramic-related complications between the 2 groups. Our study demonstrated that the 32-mm and 28-mm CoC are safe and are associated with good clinical outcomes.

Evaluation of sagittal alignment and range of motion of the cervical spine using multi-detector- row computed tomography in asymptomatic subjects.

To evaluate the sagittal alignment and range of motion (ROM) of the cervical spine during cervical flexion and extension ,using multi-detector-row-computed tomography (MDCT) in asymptomatic subjects.Understanding the normal alignment and range of motion of the cervical spine is very important while evaluating patients with cervical spine instability and abnormal alignment. Several reports using plain radiographic data have assessed the alignment and ROM of the cervical spine during flexion and extension. However, there has been no such report using MDCT. Ninety-eight subjects who did not have cervical spine-related symptoms were enrolled. After myelography, all subjects underwent cervical MDCT in cervical flexion and extension. Sagittal alignment and ROM between C2 and C7 were measured.The sagittal alignment between C2 and C7 was -11.7°±8.3° (mean ± standard deviation) in flexion and 26.5°± 12.9° in extension. The C5/6 level showed maximum kyphosis in flexion. The C6/C7 level demonstrated maximum lordosis in extension. ROM between C2 and C7 was 37.9°±11.2°. The C2/3 level showed the lowest ROM and the C5/C6 level showed the highest ROM among the intervertebral levels evaluated.The sagittal alignment and ROM of the cervical spine during flexion and extension in asymptomatic subjects were measured using MDCT. Each level between C2 and C7 could be evaluated in detail without any influence due to degenerative changes in the spine or soft tissues of the shoulder. MDCT generated a more precise understanding of the dynamic changes at each evaluated intervertebral level in the cervical spine. Level of Evidence : Level II.

Same survival but higher rate of osteolysis for metal-on-metal Ultamet versus ceramic-on-ceramic in patients undergoing primary total hip arthroplasty after 8 years of follow-up.

BACKGROUND: To avoid wear-induced osteolysis, ceramic-on-ceramic (CoC) and metal-on-metal (MoM) bearings have been developed. At present, there are no direct material related clinical comparisons between cementless total hip arthroplasty with CoC and MoM at more than 5-year follow-up. The bearing that is more likely to prevent osteolysis is still controversial. Therefore, we performed a retrospective case control study evaluating CoC and MoM cementless THAs in order to: - compare the longevity and complications for CoC and MoM THAs at 5-10 years postoperatively; - compare the incidence of osteolysis between both type THAs; - evaluate pseudotumors in MoM THAs. HYPOTHESIS: CoC THAs will have a lower rate of osteolysis, better longevity, and better clinical outcomes than MoM THAs. PATIENTS AND METHODS: Ninety-six hips underwent CoC THAs, and 56 hips underwent MoM THA (Ultamet, Pinnacle, Depuy). Average patient age at the time of surgery was 57.1 years (range, 28 to 77 years). RESULTS: There were no differences with regard to the Harris hip score (89.5 and 90.3 for the CoC and MoM groups, respectively). Osteolysis (9 hips, 14.3%) among MoM THAs were significantly more frequently observed compared to CoC THAs (2 hips, 2.1%). Kaplan-Meier survival at 8 years with implant loosening or revision THA as the endpoint was 98.2% (95% CI: 87.8-99.8) for CoC, and 98.6% (95% CI: 90.2-99.8) for MoM (p=0.684). There was one audible squeaking (1.0%) and no ceramic fracture among CoC THAs. Five (8.9%) hips showed pseudotumors among MoM THAs. DISCUSSION: CoC THAs had a low incidence of osteolysis. No significant difference was seen in the 8-year survival rate between implants, when using implant loosening and revision THA as endpoints. These data indicate that CoC THAs have excellent clinical and radiological outcomes, compared with MoM THAs. Ultamet MoM had a higher rate of osteolysis compared to other MoM bearings; the cup modularity (without polyethylene) and the use of 36mm heads as well as the process of production (after 2006) may play a significant role in the higher rate of osteolysis. LEVEL OF EVIDENCE: III, Case control study, case control retrospective design.

A Possible New Radiographic Predictor of Progression of Osteoarthritis in Developmental Dysplasia of the Hip: The Center Gap.

BACKGROUND: Patients with comparable severities of developmental dysplasia of the hip (DDH) may variably progress to osteoarthritis (OA) over time. Although joint congruency may be associated with OA progression in patients with DDH, it has only been assessed subjectively. We assessed the gap between the rotational centers of the acetabulum and femoral head (center gap) as a possible predictive measure of OA progression in patients with DDH. QUESTIONS/PURPOSES: In patients with bilateral DDH, we asked: (1) What is the probability of OA progression (Tönnis grade) or symptom development (pain) in the asymptomatic contralateral hip of patients with DDH undergoing unilateral joint-preserving surgery? (2) Is the center gap measurement associated with OA progression or symptom development in these hips? (3) Is the center gap measurement correlated with previous radiographic parameters? METHODS: A total of 297 patients (319 hips) underwent unilateral eccentric rotational acetabular osteotomy at our institution between July 1989 and December 1999. We performed no other joint-preserving surgery to treat patients with DDH during this timeframe. The inclusion criteria for the study were patients younger than 55 years of age, the contralateral hip classified as Tönnis Grade 0, no previous surgical interventions, and asymptomatic at the time of eccentric rotational acetabular osteotomy (155 patients, 155 hips). The exclusion criteria were a contralateral hip without dysplasia (four patients, four hips), loss to followup before 10 years (42 patients, 42 hips [27%]), or missing medical records or radiographs (21 patients, 21 hips [14%]). The remaining 88 patients (88 hips; 11 males and 77 females) with a mean age of 39 years (range, 17-53 years) and mean followup of 20 years (range, 10-27 years) were analyzed. From the institutional database, radiographic parameters including the center gap in the AP view were assessed using radiographs at the time of eccentric rotational acetabular osteotomy, and the Tönnis grade was recorded 1 year postoperatively and annually thereafter retrospectively. We defined migration of the rotational center of the femoral head based on the rotational center of the acetabulum in the horizontal plane as center gap X (mm) and in the vertical plane as center gap Y (mm) and defined the absolute value between the centers as center gap distance (mm). Using κ statistics, intra- and interobserver reliabilities were determined to be 0.896 and 0.857 for center gap X, 0.912 and 0.874 for center gap Y, and 0.912 and 0.901 for the center gap distance, respectively. When patients reported any contralateral ipsilateral hip pain during clinic visits, the hip was considered symptomatic. Kaplan-Meier survivorship analyses were performed with OA progression or symptom development in the nonoperative hip as the endpoint. Multivariate analyses were performed to assess risk factors for each outcome using the Cox proportional hazards model. Correlation analyses between the center gap and other parameters including lateral center-edge angle, femoral head extrusion index, acetabular depth-to-width index, femoral head lateralization, minimum width of the joint space, head sphericity, and joint congruency were performed using Pearson's correlation coefficient. RESULTS: At 20 years postoperatively, the probability of OA progression in the nonoperative hip was 13% (95% confidence interval [CI], 7.1-22.1) and the probability of symptom development was 34% (95% CI, 24.7-46.1). The center gap X measurements in the groups with OA progression (lateral 2.0 ± 2.1 [SD] mm) or symptom development (lateral 0.9 ± 2.4 mm) took a more lateral direction than those in the group without OA progression (medial 0.4 ± 2.1 mm) or symptom development (medial 0.5 ± 2.0 mm) (OA progression, p < 0.001; symptom development, p = 0.005). The center gap Y measurements in the groups with OA progression (distal 2.7 ± 7.1 mm) or symptom development (distal 2.1 ± 6.0 mm) took a more distal direction than those in the group without OA progression (proximal 1.6 ± 6.2 mm) or symptom development (proximal 2.5 ± 6.1 mm) (OA progression, p = 0.027; symptom development, p = 0.001). Independent risk factors for OA progression were the femoral head extrusion index (hazard ratio [HR], 1.11; 95% CI, 1.01-1.22; p = 0.028) and the center gap X (HR, 1.52; 95% CI, 1.07-2.16; p = 0.019), whereas no independent risk factors for symptom development were found. The center gap in the horizontal plane had no correlations with any other radiographic parameter studied. CONCLUSIONS: The center gap in the horizontal plane had a modest association with OA progression in this group of patients with DDH. Future studies are needed to determine the normal value of the center gap for patients without DDH and to assess the center gap in lateral radiographic views. LEVEL OF EVIDENCE: Level IV, prognostic study.

Comparison of cementless total hip arthroplasty survivorship between metal-on-highly cross-linked polyethylene and ceramic on ceramic bearings: A case control study with a 5-9-year follow-up.

BACKGROUND: Currently, there is a lack of evidence on the medium-term follow-up of cementless total hip arthroplasty (THA) using metal-on-highly cross-linked polyethylene bearing (MoXPE), ceramic on ceramic bearing (CoC) at more than 5 years follow-up. Therefore, we performed a case control study to: compare the incidence rate of osteolysis; compare the longevity for both types of THAs, and to evaluate the wear rate of MoXPE THAs. HYPOTHESIS: CoC THAs will have a lower rate of osteolysis and better longevity than MoXPE THAs. PATIENTS AND METHODS: We performed a retrospective analysis of 77 MoXPE (68 women, 9 men) and 105 CoC (85 women, 20 men) THAs, with an average patient age at the time of surgery of 64.7 years (range, 27 to 76 years). The cohorts were matched according to sex, body mass index, or diagnosis of hip joint disease. Clinical and radiologic measurements were analyzed at a mean follow-up of 6.7 years (range, 5-9 years). RESULTS: There were no between-group differences with regard to the Harris hip score (87.0 [64.0-98.0] and 89.9 [70.0-100.0] for the MoXPE and CoC group, respectively) and the incidence rate of osteolysis (2.6% and 1.9%, respectively). Revision was required for 1 case for each THA type. The Kaplan-Meier survival at 8 years, using implant loosening or revision as the end-point of analysis, was 96.1% (95% confidence interval [CI], 90.0-99.3) for the MoXPE group and 98.9% (95% CI, 92.2-99.8) for the CoC group (p=0.189). The mean annual liner wear rate was 0.0160mm/year (range, 0.0050 to 0.0390mm/year) for the MoXPE THAs. DISCUSSION: There was no difference between CoC and MoXPE THAs in the incidence of osteolysis or in survival rate at 8 years post-surgery. Excellent clinical and radiological outcomes were obtained for both types of bearings. LEVEL OF EVIDENCE: III, Case control study, case control retrospective design.

The influence of early radiolucent lines appearing on femoral head penetration into HXLPE cemented sockets.

INTRODUCTION: This study investigates differences in femoral head penetration between highly cross-linked polyethylene (HXLPE) cemented sockets both with and without radiolucent lines (RLLs) in the early postoperative phase and at 5 years follow-up. METHODS: There were 35 patients (37 hips), mean age of 66.8 years, who underwent total hip arthroplasty (THA) using highly HXLPE cemented sockets. They were divided into 2 groups based on postoperative the early appearance of RLLs. Femoral head penetrations on both anteroposterior- and Lauenstein-view radiographs were evaluated, and the mean polyethylene (PE) wear rate was calculated based on femoral head penetrations between 2 and 5 years. RESULTS: Femoral head penetrations in the proximal direction were 0.075 mm and 0.150 mm in the RLL and non-RLL groups at 1 year postoperatively ( p = 0.019). At 5 years measured penetration was 0.107 mm and 0.125 mm in the RLL and non-RLL groups, respectively ( p = 0.320). The mean PE wear rates in anteroposterior-view were 0.008 mm/year and 0.003 mm/year in the RLL and non-RLL groups ( p = 0.390) and those in Lauenstein-view were 0.010 mm/year and 0.005 mm/year, respectively ( p = 0.239). CONCLUSIONS: In the RLL group, the PE bedding-in was less compared with those in the non-RLL group. Additionally, the mean PE wear rate in the RLL group tended to be higher than that in the non-RLL group. The distribution of stress loading through the cement may differ according to whether early RLLs appear.