Can necrotic depth be a substitute of necrotic volume to predict collapse progression in osteonecrosis of the femoral head?

OBJECTIVE: Although some patients may experience collapse progression while others may not in post-collapse osteonecrosis of the femoral head (ONFH) with a necrotic lesion located within the weight-bearing part of the acetabulum (Type B/C1), few studies have focused on the natural course after collapse. This study aimed to clarify the correlation between necrotic volume (NV) and necrotic depth (ND) in predicting collapse progression in patients with post-collapse ONFH Type B/C1. MATERIALS AND METHODS: We retrospectively reviewed 54 hips with post-collapse ONFH Type B/C1 from 52 consecutive patients who were conservatively followed up for more than 1 year. We measured the amount of femoral head collapse using biplane radiographs at each follow-up period, and produced Kaplan-Meier survival curves with collapse progression (≥ 1 mm) as the endpoint. We compared NV and ND, which were calculated as the ratio of the distance from the articular surface of the femoral head to the deepest point of a necrotic lesion to the femoral head diameter in the mid-coronal slice of T1-weighted magnetic resonance imaging (MRI). RESULTS: We observed collapse progression in 31 hips (57.4%). The NV and ND were significantly greater in hips with collapse progression than in those without collapse progression (p = 0.0127 and 0.0047, respectively). Necrotic volume was significantly correlated with ND　(rs = 0.56, p < 0.0001). CONCLUSION: This study suggests that necrotic depth on the mid-coronal slice of T1-weighted MRI can be a substitute for necrotic volume to predict collapse progression in ONFH Type B/C1.

Effects of the location of both anterior and lateral boundaries of the necrotic lesion on collapse progression in osteonecrosis of the femoral head.

BACKGROUND: The location of the lateral boundary of the necrotic lesion to the weight-bearing portion of the acetabulum (Type classification) is an important factor for collapse in osteonecrosis of the femoral head (ONFH). Recent studies also reported the significance of the location of the anterior boundary of the necrotic lesion on the occurrence of collapse. We aimed to assess the effects of the location of both anterior and lateral boundaries of the necrotic lesion on collapse progression in ONFH. METHODS: We recruited 55 hips with post-collapse ONFH from 48 consecutive patients, who were conservatively followed for more than one year. Using a plain lateral radiograph (Sugioka's lateral view), the location of the anterior boundary of the necrotic lesion to the weight-bearing portion of the acetabulum was classified as follows: Anterior-area I (two hips) occupying the medial one-third or less; Anterior-area II (17 hips) occupying the medial two-thirds or less; and Anterior-area III (36 hips) occupying greater than the medial two-thirds. The amount of femoral head collapse was measured by biplane radiographs at the onset of hip pain and each follow-up period, and Kaplan-Meier survival curves with collapse progression (≥1 mm) as the endpoint were produced. The probability of collapse progression was also assessed by the combination of Anterior-area and Type classifications. RESULTS: Collapse progression was observed in 38 of the 55 hips (69.0%). The survival rate of hips with Anterior-area III/Type C2 was significantly lower. Among hips with Type B/C1, collapse progression occurred more frequently in hips with Anterior-area III (21 of 24 hips) than in hips with Anterior-area I/II (3 of 17 hips, P < 0.0001). CONCLUSIONS: Adding the location of the anterior boundary of the necrotic lesion to Type classification was useful to predict collapse progression especially in hips with Type B/C1.

Predictors of physical activity recovery after total hip arthroplasty: a prospective observational study.

PURPOSE: Little is known about the changes and the factors in physical activity as following total hip arthroplasty (THA). There are potential discrepancies between subjective and objective measurements of physical activity. Thus, our porpose is to compare objective and subjective measurements of activity levels in patients undergoing THA preoperatively, three months and one year following surgery, and investigated the factors that predicts the objective activity level after THA. METHODS: This prospective observational study included 42 patients with unilateral symptomatic hip osteoarthritis who underwent THA. The objective activity level (step counts, sit-to-stands, and upright time) by using a tri-axial accelerometer, PRO (Oxford hip score; OHS and University of California, Los Angeles activity score; UCLA score), and muscle volume around the hip joint by using preoperative computed tomography were measured. RESULTS: The number of steps, OHS, and UCLA score before, at three months, and one year after THA averaged 5092, 6532, and 6545 steps, 30.3, 43.0, and 44.2 points, and 3.4, 4.8, and 4.6 points, respectively, with significant postoperative increases (P < 0.05). No significant difference was found between three months and one year postoperatively. In multivariate analysis, younger age and higher preoperative contralateral gluteal medius volume were the predictors of higher postoperative step counts (P < 0.05). CONCLUSIONS: Physical activity, including step counts, OHS, and UCLA score increased significantly until three months after unilateral THA. Early surgical intervention before contralateral muscle declines and preoperative rehabilitation including contralateral side may additionally improve postoperative activity levels.

Is there a reduction in hip destruction under a treat-to-target strategy in patients with rheumatoid arthritis?

OBJECTIVES: The treatments for rheumatoid arthritis (RA) have been greatly improved, and the tight control of disease activity yields superior clinical outcomes. This study aimed to elucidate the accompanying changes in hip destruction following the implementation of a treat-to-target strategy for patients with RA. METHODS: We extracted 190 hips over two periods, i.e. the early period (1998-2003) and the late period (2013-19), with 103 and 87 hips, respectively. The observed rheumatic changes, such as inward migration, upward migration, and femoral head collapse, were quantitatively evaluated, while osteoarthritic changes, such as the formation of a capital drop, were investigated from radiographs before primary total hip arthroplasty. RESULTS: A comparison of the two periods' data showed that the degree of inward migration (-3.44 vs. -7.45 mm; P < .001) and upward migration (+4.3 vs. +0.95 mm; P < .001) significantly decreased in the late-period group. The collapse of the femoral head was not significantly different. The incidence of capital drops was significantly higher in the late-period group (7.8% vs. 27.5%; P < .001). CONCLUSIONS: The degree of inward and upward migration representative of rheumatic changes reduced, whereas the frequency of capital drops as osteoarthritic changes increased during the late period.

Risk factor analysis of vertebral fractures requiring surgery in patients with ankylosing spondylitis.

OBJECTIVES: This study aimed to determine the risk factors for vertebral fractures requiring surgery in patients with ankylosing spondylitis (AS). METHODS: We included 60 patients with AS diagnosed by using the modified New York criteria and who were treated in our department from April 2004 to March 2019. We evaluated age, sex, disease duration, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), ankylosed sacroiliac joint, bamboo spine, number of ankylosed vertebrae, and treatment (nonsteroidal antiinflammatory drugs (NSAIDs)), prednisolone (PSL), conventional synthetic disease-modifying antirheumatic drugs (csDMARDs), biological disease-modifying antirheumatic drugs (bDMARDs), spine surgery for vertebral fracture) at the final follow-up of the nonsurgical group and the preoperative follow-up of the surgical group. RESULTS: At the final follow-up, the mean age was 49 years, 46 patients (75%) were male, and the mean disease duration was 27 years. Additionally, 8 (13.3%) and 43 patients (71%) underwent surgical and medical treatments, respectively. The group of surgery for vertebral fracture had significantly higher CRP levels, which was also significantly associated with vertebral fracture surgery by multivariate analysis. CONCLUSIONS: CRP was identified as a risk factor for vertebral fractures requiring surgery. Control of systemic inflammation in patients with AS may reduce the risk of vertebral fractures requiring surgery.

Objective Activity Levels and Patient-Reported Outcomes After Total Hip Arthroplasty and Periacetabular Osteotomy: Retrospective Matched Cohort Study at Mean 12-Year Follow-Up.

BACKGROUND: There is increasing interest in improving activity after total hip arthroplasty (THA) and periacetabular osteotomy (PAO). The present study evaluated whether there were differences in the subjective and objective activity levels of THA and PAO patients at mean 12-year follow-up (range 4-20) and what factors influence the objective activity levels. METHODS: THA and PAO patients (30 patients each; mean age: 66 and 63 years, respectively), who had undergone surgery for osteoarthritis due to acetabular dysplasia, were included. Patients were retrospectively matched based on age, gender, body mass index, follow-up duration, and preoperative University of California, Los Angeles activity score (UCLA score). Patients were surveyed for the subjective activity levels using the Oxford Hip Score and UCLA score. Objective activity levels (the number of steps, upright time, and the number of sit-to-stand transitions) were made using an accelerometer. RESULTS: There was no significant difference in subjective activity level between THA and PAO patients. The number of steps was significantly higher in PAO than in THA patients. Multivariable analyses revealed that THA and low Oxford Hip Score activities of daily living were negatively associated with the number of steps, that men and high UCLA score were negatively associated with upright time, and that high body mass index was negatively associated with sit-to-stand transitions in THA and PAO patients. CONCLUSION: This study suggested that although there was no difference in postoperative subjective activity level between THA and PAO patients, there was a difference in objective activity level. Providing guidance to these patients based on objective activity may lead to higher activity levels.

Wear analysis of the first-generation cross-linked polyethylene at minimum 10 years follow-up after THA: no significant effect of sports participation.

The impact of sports on long-term wear of highly cross-linked polyethylene (XLPE) after total hip arthroplasty (THA) is not fully understood. We investigated (1) the wear performance of the first-generation XLPE, and (2) whether sports participation influences the steady wear rate of XLPE. The femoral head penetration into the cup was measured digitally on radiographs of hips undergoing THA with XLPE. We retrospectively reviewed data that included age, gender, body mass index, follow-up period, preoperative diagnosis, types of XLPE, ball diameter, head material, inclination of the cup, physical function score, and sports participation. Statistical analyses were applied to determine whether sports affect the wear of XLPE and which factors were associated with the steady wear rate. Creep and steady wear rate were found to be 0.18 mm and 0.005 mm/year, respectively. Sports participation, regardless of impact, provided no significant difference in the steady wear rate. Multiple regression analysis demonstrated that sports did not increase the steady wear rate. Our findings showed excellent wear performance of the first-generation XLPE at a minimum of ten years after THA, without significant effect of sports participation on the liner wear.

Smaller femoral neck anteversion in varus knees than in healthy and valgus knees.

It is important to investigate anatomical differences of the femur and tibia three-dimensionally between varus and valgus knees to enhance surgical approaches and better understand structural factors related to specific patterns of osteoarthritis progression. Three-dimensional femoral and tibial bone models were reconstructed from transverse computed-tomography scans in varus osteoarthritis (43 knees), valgus osteoarthritis (40 knees), and healthy (32 knees) groups. Different coordinate systems were defined in each femoral bone model ("Knee" and "Hip" Coordinate System). Femoral neck inclination, lateral bowing, anterior bowing, and neck anteversion were measured and compared between knee and hip coordinate systems. Those parameters were also compared between varus, valgus, and healthy groups. The tibial anterior and lateral bowing, external torsion and the fibular axis relative to the tibial mechanical axis were measured and compared between varus and valgus groups. Femoral neck anteversion was significantly 1-2° greater in the hip coordinate system compared to the knee coordinate system. Femoral neck anteversion was significantly smaller in varus knees than in healthy or valgus knees, with average difference of approximately 5°. The knee and hip joint are often rotated externally relative to the trunk axis in patients with varus osteoarthritis, perhaps maintaining the geometric relations between pelvis and proximal femur (including peripheral hip muscles) regardless of knee deformities. The fibular axis was inclined slightly valgus and posteriorly in two groups. The results may inform hypotheses on, and future studies of, skeletal morphologic development and factors contributing to the progression of knee osteoarthritis.

Analysis of factors influencing patient satisfaction after total hip arthroplasty in a Japanese cohort: the significant effect of postoperative physical activity.

[Purpose] To determine patient satisfaction after total hip arthroplasty in a Japanese cohort and to identify factors that significantly influence patient satisfaction. [Participants and Methods] This study included 285 patients who underwent primary total hip arthroplasty for osteoarthritis. Postoperative satisfaction, Oxford hip score, short form-12 mental component summary score, and University of California Los Angeles activity score were investigated. Muscle strength and daily step counts were determined using a hand-held dynamometer (µ-Tas F1) and activity monitor (ActivPAL) in 89 and 26 patients, respectively. Factors associated with postoperative satisfaction, Oxford hip score-activities of daily living, and University of California Los Angeles activity score were identified. The relationship between the Oxford hip score-activities of daily living and daily step counts was examined. [Results] Overall, 94.7% of the patients reported satisfaction with total hip arthroplasty. The Oxford hip score-activities of daily living and University of California Los Angeles activity score were significantly associated with patient satisfaction. Younger age and hip abductor strength were significantly associated with a higher Oxford hip score-activities of daily living and University of California Los Angeles activity score. The average daily step count was significantly correlated with the Oxford hip score-activities of daily living. [Conclusion] Self-reported physical activity levels significantly influenced patient satisfaction and were correlated with objective muscle strength and daily step count measurements. These findings can guide total hip arthroplasty patient counseling on the importance of muscle strength and activity levels.

Preoperative predictive factors affecting return to work in patients with gliomas undergoing awake brain mapping.

PURPOSE: This study aimed to investigate the preoperative predictive factors affecting return to work in patients with gliomas in the left cerebral hemisphere undergoing awake surgery. METHODS: We retrospectively reviewed 50 consecutive glioma patients who underwent awake surgery from January 2012 to July 2017. Adult patients older than 18 years, who reported working prior to surgery, were recruited for this study. RESULTS: Comparing sociodemographic, disease-related and preoperative neurocognitive variables of glioma patients who returned to work and those who did not, binomial logistic regression models for preoperative predictors affecting return to work revealed significant differences in age and sole breadwinner status as sociodemographic variables, tumour volume as a disease-related variable, and Verbal IQ, Performance IQ, general memory, attention/concentration, and working memory as neurocognitive variables. Multivariate logistic regression models demonstrated that the independent factors associated with propriety of returning to work 1 year after surgery was the sociodemographic variable sole breadwinner status (yes vs no; OR = 15.00, 95% CI 2.22-101.35, p = 0.01), the disease-related variable tumour volume (per 1 cm3; OR = 0.98, 95% CI 0.96-0.99, p = 0.04), and the preoperative neurocognitive variable general memory (≥ 100 vs < 100; OR = 21.70, 95% CI 2.60-183.94, p = 0.01). CONCLUSIONS: Our results suggest that three predictive factors including sole breadwinner status, tumour volume and general memory that can be assessed in the preoperative stage substantially contribute to returning to work in patients with gliomas in the left cerebral hemisphere, 1 year after awake surgery.

Dynamic hip kinematics before and after periacetabular osteotomy in patients with dysplasia.

BACKGROUND: We prospectively analyzed the hip kinematics in patients with developmental dysplasia of the hip (DDH) before and after periacetabular osteotomy (PAO) and in healthy subjects while squatting to determine the influence of coverage of the femoral head on hip kinematics. METHODS: 14 hips in 14 patients with DDH and 10 hips in 10 volunteers were included. Continuous radiographs while squatting and computed tomography images were obtained to assess the in vivo kinematics of the hip and the rim-neck distance using density-based 3D-to-2D model-to-image registration techniques. RESULTS: The maximum hip flexion angles were 100.4° and 94.9° before and after PAO (p = 0.0863), respectively. The maximum hip flexion angles after PAO did not significantly differ from those of normal hips (102.2°; p = 0.2552). The hip abduction angles at maximum hip flexion were 31.7° and 26.2° before and after PAO (p = 0.1256), respectively. The rim-neck distance decreased from averaged 12.2 mm-8.9 mm (p = 0.0044) after PAO. The lateral center edge angle (LCEA) and anterior center edge angle (ACEA) significantly improved 14.7°-42.4° and 50.4°-54.0° after PAO (p < 0.0001, p = 0.0347), respectively; in particular, the ACEA after PAO did not significantly differ from that in the normal hips (p = 0.1917). The ACEA was not correlated with hip flexion, or the rim-neck distance (p = 0.9601, 0.8764). The LCEA was also not correlated with hip abduction (p = 0.1683). CONCLUSION: Patients after PAO showed no significant difference in maximum hip flexion while squatting compared to before PAO and normal hips. Horizontalized weight-bearing acetabulum with normalized ACEA could be adequate correction of the acetabular fragment to restore hip RoM without coxalgia that induce the inability to perform squats after PAO.

In vivo kinematics, component alignment and hardware variables influence on the liner-to-neck clearance during chair-rising after total hip arthroplasty.

BACKGROUND: There is an interest in quantifying dynamic hip kinematics before and after total hip arthroplasty (THA) during chair-rising: one of daily life activities. METHODS: The study consisted of 21 patients who underwent unilateral total hip arthroplasty for symptomatic osteoarthritis. We obtained continuous radiographs using a flat-panel X-ray detector while the participants rose from chair. We assessed the pre and postoperative hip joint's movements using three-dimensional-to-two-dimensional model-to-image registration techniques. We also measured minimum liner-to-neck distances at maximum hip flexion and extension as anterior and posterior liner-to-neck distances, respectively. Multivariate analyses were applied to determine which factors were associated with liner-to-neck distances. RESULTS: The cup inclination, cup anteversion, and stem anteversion averaged 37.4°, 23.1°, and 30.1°, respectively. Significantly larger maximum hip flexion angle (72°) was found during chair-rising after THA compared to that before THA (63°, P < 0.01). The anterior pelvic tilt at the maximum hip flexion after THA (3° of anterior tilt) was significantly (P < 0.05) anterior compared to that before THA (1° of posterior tilt). The anterior and posterior liner-to-neck distances averaged 12.3 mm and 8.1 mm, respectively, with a significant difference (P < 0.01). No liner-to-neck contact was found in any hips. In multivariate analysis, the hip flexion angle, cup inclination, stem anteversion and head diameter were significantly associated with the anterior liner-to-neck distance (P < 0.05), the hip extension angle, cup anteversion, neck length and with or without elevated rim were significantly associated with the posterior liner-to-neck distance (P < 0.05, 0.01, 0.05, 0.01, respectively). CONCLUSION: This study indicates that well-positioned THA provide increased range of hip flexion with sufficient anterior liner-to-neck clearance during chair-rising. Dynamic hip kinematics, component position, and hardware variables significantly influenced on the liner-to-neck clearance under weight-bearing conditions.

Opalski Syndrome Treated with Intravenous Recombinant Tissue Type Plasminogen Activator-Case Report and Review of Literature.

A 65-year-old man with a history of Wallenberg syndrome caused by vertebral artery dissection at 62 years old was admitted to our hospital with nausea, vertigo, right facial dysesthesia, right hemiplegia, crossed sensory disturbance (sensory loss and numbness in the right face and left body below the neck), and right limb ataxia. Magnetic resonance imaging (MRI) performed 80 minutes after onset revealed no acute ischemic stroke lesions, but magnetic resonance angiography (MRA) demonstrated complete occlusion of the right vertebral artery. Based on these neurological and MRA findings, atypical lateral medullary infarction was suggested, and intravenous tissue plasminogen activator (IV-tPA) was started 178 minutes after onset. Right hemiplegia improved immediately after IV-tPA administration. MRI performed on hospital day 2 showed an acute ischemic lesion on the right side of the medulla oblongata, resulting in a diagnosis of Opalski syndrome. Opalski syndrome is a rare subtype of Wallenberg syndrome accompanied by hemiplegia of the side ipsilateral to the lesion, and expansion of the stroke lesion to the corticospinal tract below the pyramidal decussation is considered to cause ipsilateral hemiplegia. Based on this case and previous reports, Opalski syndrome should be considered when limb ataxia and crossed sensory deficit are observed among patients with hyperacute-onset hemiplegia, and IV t-PA therapy should be considered even in the absence of neurological findings such as dysphagia, dysarthria, and Horner's signs and radiological evidence of acute ischemic stroke.

Reversible Cerebral Vasoconstriction Syndrome after Administering Etanercept during Puerperium.

Our objective is to clarify relationship between reversible cerebral vasoconstriction syndrome and administrating etanercept during puerperium. Several lines of evidence have suggested tumor necrosis factor (TNF) as a mediator of vascular dysfunction associated with estrogen deficiency. A 32-year-old woman resumed etanercept (25 mg/week), a TNF inhibitor, which had been discontinued during pregnancy, because of the deterioration of rheumatoid arthritis. She was admitted to our hospital with upper right quadrant blindness and mild right hemiparesis accompanied by pulsating left occipital pain, which had appeared 4 hours after restarting etanercept (25 mg/week). Magnetic resonance imaging and angiography revealed acute left hippocampal infarction with multiple segmental stenoses of the main intracranial arteries. Reversible cerebral vasoconstriction syndrome was diagnosed based on improvement of the multiple stenoses on magnetic resonance angiography on hospital day 17. A causal relationship was considered to exist between TNF inhibition by etanercept and multiple cerebral vasoconstrictions with brain infarct in this puerperant.

Do component position and muscle strength affect the cup-head translation during gait after total hip arthroplasty?

INTRODUCTION: This study examined whether the component position or muscle strength affects the cup-head translation under in vivo weight-bearing conditions after total hip arthroplasty (THA). We hypothesized that there was a correlation between the hip offset or abductor strength and cup-head translation during gait. MATERIALS AND METHODS: We prospectively evaluated 31 patients undergoing unilateral cementless primary THA. The cup height, cup/stem offset, and limb length discrepancy were measured on anterior-posterior bilateral hip radiographic images. The isometric muscle strength of the lower limbs was quantified using a handheld dynamometer. Continuous radiographic images were recorded during gait, and cup-head translation was analysed using a computer-assisted method. RESULTS: The average cup height, cup/stem offset, and limb length discrepancy were - 3.8 ± 5.1 mm, 1.2 ± 5.2 mm/- 0.7 ± 7.7 mm, and - 2.1 ± 5.2 mm, respectively. The average hip abductor/flexor and knee extensor strength were 86% ± 18%/85% ± 17% and 88% ± 17% of the contralateral healthy hip, respectively. The average cup-head translation during swing phase of gait was - 0.003 ± 0.31 mm. Multiple regression analyses found no significant independent predictors of cup-head translation (p > 0.05). CONCLUSIONS: The component position or muscle strength did not significantly influence cup-head translation during gait after well-positioned primary THA.

Rheumatoid meningitis presenting with a stroke-like attack treated with recombinant tissue plasminogen activator: a case presentation.

BACKGROUND: Rheumatoid meningitis presenting with a stroke-like attack (RMSA) is a rare manifestation of rheumatoid arthritis (RA). When the patients arrive within the time-window for recombinant tissue plasminogen activator (rt-PA) infusion therapy, no diagnostic protocol has been established. CASE PRESENTATION: A 55-year-old woman was brought by ambulance to our hospital with complaints of sudden-onset dysarthria and left arm numbness. The National Institutes of Health Stroke Scale (NIHSS) score was 5, and the Alberta Stroke Program Early CT Score was 8. She was diagnosed with acute embolic stroke. At 4 h, 6 min after onset, intravenous administration of rt-PA (alteplase, 0.6 mg/kg) was started. Her neurological deficits improved rapidly, and her NIHSS score was 1. Brain MRI was then performed. There was no hemorrhagic transformation, but the MRI findings were not compatible with ischemic stroke. She had a past history of RA diagnosed 6 months earlier, and she had been treated with methotrexate (10 mg daily). She was diagnosed with RMSA, and continuous infusion of methylprednisolone 1000 mg daily was started for 3 days. The high signal intensity on the FLAIR image disappeared. CONCLUSION: CT-based decision-making for rt-PA injection is reasonable, but MRI is needed for the early diagnosis of RMSA. In this case, it is particularly important that neither adverse events nor bleeding complications were observed, suggesting the safety of CT-based thrombolytic therapy in RMSA.

Sports Participation in Patients After Total Hip Arthroplasty vs Periacetabular Osteotomy: A Propensity Score-Matched Asian Cohort Study.

BACKGROUND: No studies have compared sports participation between total hip arthroplasty (THA) and periacetabular osteotomy (PAO) in matched Asian cohorts. We investigated sports participation and activity levels in Asian THA cohort, and compared them between THA and PAO cohorts. METHODS: Multivariate analyses were applied to determine which factors were associated with postoperative sports participation and University of California-Los Angeles (UCLA) activity score in (1) 524 THA patients and (2) 487 acetabular dysplasia patients (295 THA patients and 192 PAO patients). In addition, postoperative sports participation and UCLA score were compared between 62 THA and 62 PAO patients after adjusting for baseline characteristics with propensity score matching. RESULTS: Sports participation and UCLA score significantly increased after THA (P < .001 in both analyses). Preoperative sports participation was the factor most associated with both postoperative sports participation and UCLA score in both 524 THA patients and 487 acetabular dysplasia patients (P < .001 in all analyses). Multivariate analysis in 487 acetabular dysplasia patients demonstrated that THA, compared with PAO, was negatively associated with postoperative sports participation (P < .001), but not postoperative UCLA score (P = .22). THA patients showed significantly lower rate of postoperative sports participation (32.3% and 51.6%, respectively, P = .046), but not postoperative UCLA score (5.0 ± 1.6 and 5.2 ± 1.9, respectively, P = .47) compared with matched PAO patients. CONCLUSION: THA significantly increased both sports participation and activity levels. Both multivariate and propensity score-matched analyses showed that postoperative activity levels were comparable between THA and PAO cohorts.

Initial stability of a highly porous titanium cup in an acetabular bone defect model.

BACKGROUNDS: The purpose of this study was to quantify the initial stability of a highly porous titanium cup using an acetabular bone defect model. METHODS: The maximum torque of a highly porous titanium cup, with a pore size of 640 µm and porosity of 60%, was measured using rotational and lever-out torque testing and compared to that of a titanium-sprayed cup. The bone models were prepared using a polyurethane foam block and had three levels of bone coverage: 100, 70, and 50%. RESULTS: The highly porous titanium cup demonstrated significantly higher maximum torque than the titanium-sprayed cups in the three levels of bone defects. On rotational torque testing, it was found to be 1.5, 1.3, and 1.3 times stronger than the titanium-sprayed cups with 100, 70 and 50% bone coverage, respectively. Furthermore, it was found to be 2.2, 2.3, and 1.5 times stronger on lever-out testing than the titanium-sprayed cup. No breakage in the porous layers was noted during the testing. CONCLUSION: This study provides additional evidence of the initial stability of highly porous titanium cup, even in the presence of acetabular bone defects.

[Significance of Thoraco-laparoscopic Observation in Repairing Diaphragmatic Injury by the Penetrating Trauma].

A 53-year-old man with a penetrating trauma was admitted to our hospital. Thoracoabdominal computed tomography (CT) on admission showed left diaphragmatic injury and peritoneal fat in the left thoracic cavity. Under a diagnosis of the traumatic diaphragmatic injury, an emergency operation was performed, and the left diaphragm was repaired. No other injuries were found in the thoracic and abdominal organs by thoraco-laparoscopic observation. The postoperative course was uneventful, and the patient left hospital on the 14th day after surgery. In case of the diaphragm injury, it is important to confirm the probable injuries of other organs by thoraco-laparoscopic observation.

Arthroscopic validation of radiographic minimum joint space width associated with the subchondral bone exposure in symptomatic hip dysplasia.

OBJECTIVE: The purpose of this study was to clarify the minimum joint space width (MJSW) that leads to subchondral bone exposure (SBE) in patients with hip dysplasia. METHODS: We included 82 subjects (86 hips) who had hip dysplasia with center-edge angle less than 20° and who underwent periacetabular osteotomy combined with hip arthroscopy. The acetabular and femoral cartilages were divided into three regions: anterosuperior, superior, and posterosuperior; for each region, we analyzed the correlation between the incidence of SBE and the MJSW measured on plain radiographs. The disease stage was defined according to the Kellgren and Lawrence grades (KL grade). RESULTS: SBE was found in 51 hips (59.3%) in total, involved the acetabulum in 49 hips (57.0%), and involved the femoral head in 26 hips (30.2%). SBE was more frequent in the acetabulum, with the highest incidence in the anterosuperior region, followed by the superior region. SBE was present in six hips (22.2%), 17 hips (56.7%), and 28 hips (96.5%), at KL-1, KL-2, and KL-3, respectively. MJSW of hips with SBE was significantly smaller than those without SBE (2.3 vs 4.0 mm, p < 0.001), and the cut-off value for MJSW that led to SBE was 3.7 mm (sensitivity: 0.902, 1 - specificity: 0.343). SBE was present in 23.3% in patients with MJSW ≥3.7 mm, whereas 76.7% in those <3.7 mm. CONCLUSIONS: Cartilage degeneration is more advanced than would be predicted on plain radiographs. The cut-off value of MJSW for SBE was 3.7 mm in patients with symptomatic hip dysplasia.