Does living at high altitude increase the risk of bleeding events after total knee arthroplasty? A retrospective cohort study.

OBJECTIVE: Post-operative bleeding after total knee arthroplasty (TKA) is a frequent cause of post-operative complications. This study compared blood loss and indicators of coagulation and fibrinolysis between TKA patients living at low or high altitudes. METHODS: We retrospectively analyzed 120 patients at our institution who underwent primary TKA from May 2019 to March 2020, and we divided them into those living in areas about 500 m or > 3000 m above sea level. We compared the primary outcome of total blood loss between them. We also compared them in terms of several secondary outcomes: coagulation and fibrinolysis parameters, platelet count, reduction in hemoglobin, hidden blood loss, intra-operative blood loss, transfusion rate, and incidence of thromboembolic events and other complications. RESULTS: Total blood loss was significantly higher in the high-altitude group than in the low-altitude group (mean, 748.2 mL [95% CI, 658.5-837.9] vs 556.6 mL [95% CI, 496.0-617.1]; p = 0.001). The high-altitude group also showed significantly longer activated partial thromboplastin time, prothrombin time, and thrombin time before surgery and on post-operative day one, as well as increased levels of fibrinogen/fibrin degradation product on post-operative days one and three. Ecchymosis was significantly more frequent in the high-altitude group (41.7 vs 21.7%; relative risk (RR) = 1.923 [95% CI, 1.091-3.389]; p = 0.019). The two groups showed similar transfusion rates, and none of the patients experienced venous thromboembolism, pulmonary embolism, or infection. CONCLUSION: High altitude may alter coagulation and fibrinolysis parameters in a way that increases risk of blood loss after TKA. Such patients may benefit from special management to avoid bleeding events.

Effects of Total Hip Arthroplasty on Axial Alignment of the Lower Limb in Patients with Unilateral Developmental Hip Dysplasia (Crowe type IV).

BACKGROUND: The aim of this study was to evaluate the influence of total hip arthroplasty on axial alignment of the lower limb in adults with unilateral developmental hip dysplasia (Crowe type IV). METHODS: We retrospectively reviewed medical records of 50 adults who underwent total hip arthroplasty, in which the acetabular cup was placed in the anatomical position. The following parameters were measured before surgery, immediately after surgery, and two years later: mechanical axis deviation (MAD), tibiofemoral angle (TFA), femoral offset, hip-knee-ankle angle (HKA), mechanical lateral distal femoral angle (LDFA), mechanical medial proximal tibial angle, height of medial femoral condyle, height of lateral femoral condyle, and leg lengthening. Length of the resected femoral segment was also recorded from medical records. RESULTS: Preoperative MAD, TFA, HKA, and LDFA of the ipsilateral lower limb showed significant valgus deformity. MAD of the ipsilateral lower limb and valgus inclination were significantly smaller immediately after surgery than before, while TFA, HKA, femoral offset, and LDFA were significantly larger (P < 0.05). These parameters did not differ significantly between immediately after surgery and two years later (P > 0.05). Ipsilateral extremities were extended by a mean of 2.54 cm (range, 0 to 5.35 cm). The mean length of the femoral resected segment was 3.56 cm (range, 2.03 to 5.74 cm). The contralateral lower limb showed marginally smaller MAD and medial proximal tibial angle after surgery than before, but larger LDFA, TAF, and HKA. CONCLUSIONS: In patients with developmental hip dysplasia who underwent total hip arthroplasty with placement of the acetabular component at the level of the anatomic hip center, axial alignment of the ipsilateral lower limb was immediately altered, and valgus inclination was significantly reduced. The procedure only slightly altered the axial alignment of the contralateral lower limb.

Comparison of cortisol and inflammatory response between aged and middle-aged patients undergoing total hip arthroplasty: a prospective observational study.

BACKGROUND: To investigate the differences in the perioperative serum cortisol, C-reactive protein (CRP) and interleukin-6 (IL-6) levels between aged and middle-aged patients undergoing total hip arthroplasty (THA). METHODS: Sixty patients (30 aged and 30 middle-aged) undergoing THA for osteoarthritis between August 2016 and January 2017 participated in this study. Blood samples were collected preoperatively and at 6 hours, 24 hours and 3 days after surgery to measure the cortisol, CRP and IL-6 concentrations. The clinical outcomes were assessed using the visual analogue scale (VAS) pain score and Harris hip score (HHS). RESULTS: No significant differences were found between the two groups before the operation in the cortisol, IL-6 and CRP levels; the VAS score; or the HHS. Cortisol was significantly lower at 6 hours after surgery in the aged group than in the middle-aged group (P < 0.05). IL-6 at 6 and 24 hours after surgery, CRP at 3 days after surgery and the VAS score at 6 and 24 hours after surgery in the aged group were significantly higher than those in the middle-aged group (P < 0.05). In the aged group, weak correlations were found between the cortisol concentration 6 hours after THA and the IL-6 level 24 hours after THA (r = -0.37, P = 0.04) and between the IL-6 level 6 hours after THA and the VAS score 24 hours after THA (r = 0.42, P = 0.02). CONCLUSION: Aged patients showed lower cortisol levels at 6 hours after surgery and higher IL-6 levels at 6 and 24 hours after surgery than middle-aged patients undergoing THA.

Comparison of Early Functional Recovery After Total Hip Arthroplasty Using a Direct Anterior or Posterolateral Approach: A Randomized Controlled Trial.

BACKGROUND: Controversy exists as to whether early functional outcomes differ after total hip arthroplasty performed using the direct anterior approach (DAA) or the posterolateral approach (PLA). METHODS: One hundred twenty patients were enrolled in this study and were divided into 2 groups based on surgical approach. Group A included patients who had a total hip arthroplasty with a DAA, whereas group B included those with a PLA. Patients were randomized into the DAA or PLA groups (n = 60), and perioperative and postoperative outcomes were recorded. RESULTS: When compared with the PLA, the DAA had a shorter incision length (9.1 vs 13.1 cm; P < .01), shorter hospital stay (2.8 vs 3.3 days, P = .04), and lower self-reported pain. Both serum inflammatory and muscle damage markers were lower in the DAA group. However, the PLA had shorter operative times (65.5 vs 83.3 min, P = .03) and less intraoperative blood loss (123.8 vs 165.9 mL, P = .04). The DAA had significantly lower variance in cup inclination and anteversion. Similar rates of intraoperative complications were identified in the 2 groups. The DAA was associated with better functional recovery at 3 months based on the Harris hip score, University of California Los Angeles activity score, and gait analysis; however, functional recovery at 6 months was similar between the 2 groups. CONCLUSION: We found functional advantages in early recovery after the DAA compared with the PLA. The DAA can offer rapid functional recovery with less muscle damage, greater pain relief, and lower variance in cup inclination and anteversion. However, no functional difference was found at 6 months follow-up.

Risk factors for venous thromboembolism of total hip arthroplasty and total knee arthroplasty: a systematic review of evidences in ten years.

BACKGROUND: Risk factors for venous thromboembolism (VTE) of total joint arthroplasty (TJA) have been examined by many studies. A comprehensive systematic review of recent findings of high evidence level in this topic is needed. METHODS: We conducted a PubMed search for papers published between 2003 and 2013 that provided level-I and level-II evidences on risk factors for VTE of TJA. For each potential factors examined in at least three papers, we summarize the the number of the papers and confirmed the direction of statistically significant associations, e.g. "risk factor" "protective factor" or "controversial factor". RESULTS: Fifty-four papers were included in the systematic review. Risk factors found to be associated with VTE of both total hip arthroplasty and total knee arthroplasty included older age, female sex, higher BMI, bilateral surgery, surgery time > 2 hours. VTE history was found as a VTE risk factor of THA but an controversial factor of TKA. Cemented fixation as compared to cementless fixation was found as a risk factor for VTE only of TKA. TKA surgery itself was confirmed as a VTE risk factor compared with THA surgery. CONCLUSIONS: This systematic review of high level evidences published in recent ten years identified a range of potential factors associated with VTE risk of total joint arthroplasty. These results can provide informations in this topic for doctors, patients and researchers.

The influence of body mass index on the outcomes of primary total knee arthroplasty.

PURPOSE: The body mass index (BMI) is widely recognized as a prognostic factor in multiple operations; however, the relationship between the BMI and outcomes following total knee arthroplasty (TKA) is extensively debated. We aimed to evaluate the effect of the BMI at different cutoff values on the outcomes following primary TKA. METHODS: Electronic databases (PubMed/Medline, CENTRAL, Embase and Web of Science) were systematically searched for studies investigating the association between the BMI and outcomes following primary TKA. Two investigators independently reviewed studies for eligibility, assessed the study quality using the Newcastle-Ottawa Scale and extracted the data. A meta-analysis was performed using Review Manager software. RESULTS: Twenty-eight articles including a total of 20,988 TKAs were identified. The postoperative Knee Society Score appeared to trend lower in obese (BMI ≥ 30 kg/m(2)) patients than in non-obese (BMI < 30 kg/m(2)) patients. The meta-analysis showed that revision with follow-up ≥5 years, any infection, superficial infection and deep vein thrombosis occurred statistically more frequently in obese patients, whereas a deep infection occurred statistically more frequently in morbidly obese (BMI ≥ 40 kg/m(2)) patients than in non-obese patients. No differences in aseptic loosening with follow-up ≥5 years, pulmonary embolism and perioperative mortality rates were found between obese and non-obese patients. CONCLUSIONS: Patients with a BMI ≥ 30 kg/m(2) are at a higher risk of lower functional scores and developing complications following primary TKA. It appears reasonable to encourage obese patients to lose weight before selective TKA. LEVEL OF EVIDENCE: Prognostic study, Level III.

[Reliability and Validity of Function Score for Adult Tibetans with Kashin Beck Disease in Aba Tibetan Autonomous Area in Sichuan Province].

OBJECTIVE: To validate the function score for adult Tibetans with Kashin-Beck disease (FSAT- KBD) measuring daily life and work functional status of KBD patients. METHODS: From September to October 2010, 352 adult KBD patients in Rangtang County of Aba Tibetan autonomous region were invited to complete FSAT-KBD. The internal consistency of FSAT-KBD was assessed using Cronbach's alpha coefficients. Principal component analysis with varimax rotation was performed to explore factor structure of the instrument, with item-domain correlations being examined using Spearman's rank correlation tests. Discriminant validity of the FSAT-KBD was assessed by comparing scores of the respondents with different ages and different functional status. Convergent validity of the FSAT-KBD was assessed through a comparison with the medical outcomes study short form health survey (SF-12) and visual analogue scale (VAS). RESULTS: 338 KBD patients (a response rate of 96.0%) completed the questionnaire in an average of (3.2 +/- 1.6) min. The instrument achieved a Cronbach's alpha of 0.945, with item-to-domain correlations exceeding 0.0. Two latent factors were extracted, which explained 72.8% of the total variance. The factor structure fitted well with our conceptual hypothesis. Respondents with different age, duration of suffering and number of affected joints had different FSAT-KBD scores. The FSAT-KBD results were correlated with those of SF-12 and VAS. CONCLUSION: FSAT-KBD is a reliable and valid instrument for measuring daily functional status of adult KBD patients in Aba Tibetan autonomous area in China.

[Acetabular morphological analysis in patients with high dislocated DDH using three-dimensional surface reconstruction technique].

OBJECTIVE: To simulate acetabular morphology and perform acetabular quantitative analysis in high dislocated developmental dysplasia of the hip (DDH) patients using three-dimensional (3D) surface reconstruction technique, in order to understand the acetabular anatomic features and develop operative strategies for acetabular reconstruction. METHODS: 3D pelvic images were reconstructed by Mimics software from CT data of 13 patients (13 hips) with high developmental DDH and 13 normal persons (26 hips). True acetabular superior-inferior diameter, anterior-posterior diameter, acetabular depth, medial wall thickness, abduction angle and anteversion angle were measured and compared between the two groups of participants. RESULTS: Irregular acetabular shape was found in high dislocated group, showing a triangle with wide upper and narrow lower. The acetabular quantitative analysis revealed (38.29 +/- 2.71) mm superior-inferior diameter, (21.74 +/- 5.33) mm anterior-posterior diameter, (15.50 +/- 2.93) mm acetabular depth, (6.80 +/- 2.97) mm medial wall thickness, (49.29 +/- 7.40) degrees abduction angle and (23.82 +/- 11.21) degrees anteversion angle in high dislocated patients. The superior-inferior diameter, anterior-posterior diameter and acetabular depth of high dislocated patients were significantly smaller than those of the normal contirols (P<0.05). However, the medial wall thickness, abduction angle and anteversion angle of high dislocated patients were significantly bigger than those of the normal controls (P<0.05). CONCLUSION: 3D reconstruction technique can restore true acetabular morphology and perform quantitative analysis. Compared with normal controls, high dislocated DDH patients have acetabular features: irregular shape, lower opening, higher medial wall and bigger abduction and anteversion angles. Joint arthroplasty surgery in high dislocated DDH patients needs to look at these acetabular features.

Total knee arthroplasty in elderly patients with severe Kashin-Beck disease of the knee.

PURPOSE: The treatment of elderly KBD knee remains a significant clinical challenge, and clinical data are lacking. This study aimed to prospectively determine the functional outcomes of total knee arthroplasty (TKA) in adult patients with severe Kashin-Beck disease (KBD) of the knee. METHOD: Fifteen cases that included 18 occurrences of KBD of the knee were treated by primary knee arthroplasty and followed up for at least two years. Clinical assessments for each patient were performed at time zero (pre-operatively), one, three, six and 12 months and yearly thereafter. The efficacy measures included the visual analogue scale (VAS) pain score, Hospital for Special Surgery (HSS) score, and Functional Score for Adult Tibetans with Kashin-Beck Disease (FSAT-KBD) as well as radiographic findings. RESULTS: All patients were followed for a mean length of 32.47±10.05 months. All force lines in the lower limbs had been improved significantly. No radiographic evidence of loosening or changes in component positioning was observed at the last follow up. The VAS decreased significantly during the first six months after surgery and was maintained until the last follow up (p < 0.01). Similar trends were found in both HSS and FSAT-KBD, which increased significantly post-operatively (p < 0.01). CONCLUSION: Knee arthroplasty can reduce pain and improve function in patients with severe KBD of the knee. Additional studies will be necessary to confirm our findings.

Comparison of three different tourniquet application strategies for minimally invasive total knee arthroplasty: a prospective non-randomized clinical trial.

INTRODUCTION: It is still controversial on the optimal timing of tourniquet used in total knee arthroplasty (TKA). Most previous studies focused on the comparison of different tourniquet application in controversial TKA, while the aim of our work was to compare three strategies of tourniquet application in minimally invasive TKA. MATERIALS AND METHODS: 90 patients were enrolled in this study. Based on the different tourniquet application strategies, they were divided into three groups. Group A: using tourniquet during the whole surgery; Group B: tourniquet inflated before incision and deflated after the hardening of the cement; Group C: using tourniquet during the cementation. Blood loss and serum levels of C-reactive protein, IL-6, creatine kinase and myoglobin were checked preoperatively. The HSS knee score, VAS pain score, range of motion (ROM), limb swelling and hospital stays were also recorded. RESULTS: The mean levels of Hb and Hct were lower in Group C (104.2 ± 10.4 g/L, 31.8 ± 3.2 %) than those in Groups A (111.4 ± 14.4 g/L, p = 0.035; 34.1 ± 4.1 %, p = 0.032) and B (112.8 ± 14.3 g/L, p = 0.013; 34.5 ± 3.7 %, p = 0.011) immediately after the surgery. Compared with Groups A and B, both serum inflammation and muscle damage markers were lower in Group C. There were no significant differences between the groups in terms of HSS knee score, ROM, estimated blood loss, swelling ratio, VAS pain score and hospital stays. CONCLUSIONS: Using a tourniquet full time in minimally invasive TKA causes less intraoperative blood loss and more excessive inflammation and muscle damage. However, the advantage of part-time using tourniquet did not show in early functional outcomes.

Validation of the SF-12 among adult Kashin-Beck disease patients in Aba Tibetan autonomous area in China.

To validated the 12-item Health Status Survey (SF-12) of Chinese version for evaluating health-related quality of life (HRQL) of Kashin-Beck disease (KBD) patients in Aba Tibetan autonomous area, China. 338 adult KBD patients in Rangtang County of Aba area were investigated with SF-12. Principal component analysis with varimax rotation was used to test the original factor pattern. Internal consistency reliability was assessed by using Cronbach's alpha. "Known groups" construct validity was assessed by comparing SF-12 component scores between respondents hypothesized to differ in health-related variables. Two latent factors were extracted explaining 69.4 % of the variance of the questionnaire. The factor loadings were mostly according with the principle concept, except for "vitality" (VT) and "social functioning" (SF) scales that loaded heavier on physical component. The Cronbach's alpha coefficient was 0.909 for the physical health domain, 0.900 for the mental health domain, and 0.914 for the whole scale. The SF-12 had satisfactory "known group" validity and could well discriminate the differences between patients and healthy controls and between subgroups divided by age, duration of suffering or number of affected joints. The SF-12 could be used to evaluate the HRQL of adult KBD patients in Aba Tibetan autonomous area in China and with good feasibility, reliability and validity.

Changes in bone mineral density of the acetabulum and proximal femur after total hip resurfacing arthroplasty.

Our aim was to investigate the changes in bone mineral density (BMD) of acetabulum and proximal femur after total hip resurfacing arthroplasty. A comparative study was carried out on 51 hips in 48 patients. Group A consisted of 25 patients (26 hips) who had undergone total hip resurfacing and group B consisted of 23 patients (25 hips) who had had large-diameter metal-on-metal total hip arthroplasty (THA). BMDs around the acetabulum and proximal femur were measured using dual-energy x-ray absorptiometry (DEXA) at 2 weeks, 6 months, 1 year and annually thereafter during the 3 years after surgery. At final follow-up, the acetabular net mean BMD decreased by 11% in group A and 10% in group B with no differences between two groups (P = .35). For the femoral side, in Gruen zone 1, the mean BMD increased by 4% in group A, whereas it decreased by 11% in group B (P = .029). In Gruen zone 7, the mean BMD increased by 8% at the final follow-up in group A, whereas it decreased by 13% in group B (P = .02). In both groups the mean BMD increased by 3% in Gruen zones 3, 4, 5, and 6. Stress-related bone loss of the acetabulum was comparable for MOM THA and resurfacing devices, but proximal femoral bone density increased in the resurfacing group and decreased in the THA group.

[Clinical efficacy and serum cobalt, chromium metal ion concentrations after total hip arthroplasty with three different hard-on-hard bearings].

OBJECTIVE: To compare the clinical efficacy and serum concentrations of cobalt, chromium metal ion in three different hard-on-hard bearings after total hip arthroplasty at 2-years postoperatively. METHODS: Ninety (90) THA patients were divided into ceramic-on-ceramic (COC), ceramic-on-metal (COM), metal-on-metal (MOM) group (n = 30 in each group). At preoperative and 3, 6, 12, 24 months postoperative 5 time points, serum concentrations of cobalt and chromium metal ion were measured, Harris hip score was evaluated, X-rays and color doppler ultrasound examination of the ipsilateral hip also were observed. RESULTS: The excellent rates of Harris hip score were 100% in three groups. Continuous X-rays showed no radiolucent line around the acetabular component, no osteolysis, and no inflammatory pseudotumor. After the THA operation, the metal ion levels in COM and MOM groups increased rapidly, and stabilized at 12 months, then showed a downward trend, but the chromium ion level of MOM continued to rise at 24 months, with a significant difference when compared with that at 12 months (an increase of 0.48 microg/L, P = 0.021). The serum concentrations of metal ion in COC group were relatively constant at all time points, and the cobalt, chromium ion levels of MOM group were significantly higher than those of COC and COM group. CONCLUSION: The postoperative functional recovery of the three hard-on-hard bearings all were good, and no inflammatory pseudotumor and osteolysis were found. The serum levels of cobalt, chromium ion of COM were lower than those of MOM, but higher than those of COC.

[Three-dimensional finite element analysis of acetabular prosthesis in an adult patient with total flip arthroplasty for high dislocation].

OBJECTIVE: To observe stress distributions around the acetabular prosthesis and the bones of a patient who underwent total hip arthroplasty (THA). METHODS: Finite element analysis (FEA) was performed with an osteoarthritis patient who underwent THA for her secondary hip high dislocations: Scenario A--deepened acetabulum at the true acetabulum with a small 44 mm cup; Scenario B--structural bone graft at lateral acetabular with a 48 mm cup; Scenario C--place tantalum metal acetabular reconstruction at the lateral acetabular with a 48 mm cup; Scenario D--the normal side of the hip. According to the Wasielewski methods, acetabular was divided into four zones, in the same way on the lining surface. Ten points were taken in each zone for measuring the Von Mises stress values. RESULTS: Scenario A generated significantly greater stress values in the bones in zone one than the other three scenarios. Significantly greater stress was also found in the inner surface of polyethylene over all of the four zones under scenario A compared with those of the scenario B and C, especially in zone one and two. The cup initial micro-mobility for scenario A was 49. 18 microm, 19 times of that of scenario B and 8 times of that of scenario C. CONCLUSION: (1) Deepened acetabulum with small cup can cause stress concentration in the acetabular bones and liner, leading to large cup initial micro-mobility. (2) Acetabular lateral structural bone grafting and placement of tantalum metal reconstruction have better biomechanical properties, which can enable the use of bigger cups.

[Open high tibial osteotomy through small incision with annular external fixator for treating genu varum deformity].

OBJECTIVE: To evaluate the outcomes of open high tibial osteotomy through small incision with annular external fixator for treating genu varum deformity. METHODS: We reviewed 8 cases of open high proximal tibia osteotomy through small incision with annular external fixator for patients (10 knees) with genu varum due to high tibia varum. The patients were followed up 1, 2, 3, 6, 12, 24 and 36 months after the operations. Data about infection, healing, varus angle, knee distance and Insall-Salvati index were retrieved and analysed. RESULTS: The patients had a mean varus angle of 15. 3 degrees +/- 2. 3 degrees (range, 10 degrees - 28 degrees) before the operations. The operations were all recorded as successful following a (29. 3 +/- 3. 1) month (range, 24-36 months) post-operation follow-up, with external fixator remaining stable and no instrument failures. The bones were healed at an average of (11. 2 +/- 1. 5) weeks (range, 8-12 weeks) and there was no nonunion or delayed union. The operations reduced varus angle of the knees to - 1. 1 degrees +/- 0. 6 degrees (range, - 7 degrees - 3 degrees ), indicating a significant improvement compared to that of the preoperations. There were 2 cases of superficial pin infections. CONCLUSION: Open high tibial osteotomy through small incision with annular external fixator has good fixation stability and satisfactory clinical outcomes with little complications for treating patients with genu varum deformity.

Meta-analysis comparing total hip arthroplasty with hemiarthroplasty in the treatment of displaced femoral neck fractures in patients over 70 years old.

OBJECTIVE: Total hip arthroplasty (THA) and hemiarthroplasty (HA) are effective methods currently used to treat femoral neck fracture in elderly patients, but the two options remain controversial in patients over 70 years old. The main purpose of our study was to determine whether THA or HA is a superior treatment of femoral fractures involving a displaced neck in patients who are over 70 years of age. METHODS: A computer-based online search of Medline (1970-2011), PubMed (1977-2011), and the Cochrane Central Register of Controlled Trials (2002-2011) was conducted. Six relevant randomized controlled trials with a total of 739 patients were included for the final analysis. The analysis was performed with software RevMan 5.0. RESULTS: We found that compared with THA, HA needed shorter average time and lost less blood. While over the long-term follow-up, THA patients exhibited significantly less pain and better function and were less likely to require a revision hip surgery. Postoperative infection was equally common among HA and THA patients. CONCLUSIONS: The significant differences in outcomes suggest that THA is a valuable treatment option for active elderly hip fracture individuals. However, patients who are older, impaired or institutionalized benefit from HA.

[Midterm to long-term follow-up study after hybrid total hip arthroplasty].

OBJECTIVE: To evaluate clinical and radiographic results and influencing factors of hybrid total hip arthroplasty (THA). METHODS: Totally 126 patients (135 hips) from January 1999 to December 2001 accepted hybrid THA were followed up. Components migration, periprosthetic bone changes, the polyethylene wear rate were measured radiologically. Kaplan-Meier analysis was performed to evaluate the survival of the acetabular and femoral components. End point was obvious radiological loosening or revision either or both of the acetabular and femoral components for aseptic loosening, infection or osteolysis debridement surgery. RESULTS: A total of 79 cases (85 hips) had been given follow-up. Using revision as the end point, the survival rate of acetabular was 95.2%, cemented femoral components was 98.8%. Using loosening as the end point for failure, the survival rate of acetabular was 97.6%, cemented femoral components was 100%. CONCLUSIONS: The hybrid total hip prosthesis long-term survival rate was satisfactory, especially in the femoral side. As a result of third-cement technology, the long-term survival rate of the femoral components was close to the modern cementless prosthesis.

Core Decompression Prevents Progression of Asymptomatic Type C Osteonecrosis of Femoral Head According to the Japanese Investigation Committee Classification: A Retrospective Study.

OBJECTIVE: To evaluate whether core decompression could prevent progression of asymptomatic type C osteonecrosis of the femoral head (ONFH) according to the Japanese Investigation Committee (JIC) classification. METHODS: This retrospective cohort study included 124 hips (117 patients) with asymptomatic type C ONFH. Seventy-one hips (67 patients) received core decompression (core decompression group) and 53 hips (50 patients) received no surgical treatment (control group). Clinical and radiological follow-up was conducted at 6 and 12 months, then annually until 5 years. Clinical outcomes were evaluated in terms of the Oxford hip score and UCLA Activity Level rating. Radiological outcomes were evaluated using X-ray and magnetic resonance imaging. Survival analysis was performed based on collapse of the femoral head as the first endpoint and total hip arthroplasty (THA) as the second endpoint. RESULTS: There were no significant differences in clinical outcomes between the core decompression group and the control group within 2 years after surgery. Patients in the core decompression group had significantly better Oxford hip score and UCLA Activity Level from year 3 to the end of follow-up (P < 0.05). In year 5, the absolute difference in Oxford hip score (5.3 points) exceeded the reported minimal clinically important difference (MCID, 5.2 points). In years 3-5, the absolute difference in UCLA Activity Level rating (0.95 points, 0.95 points, and 0.99 points, respectively) exceeded the reported MCID (0.92 points). By 5-year follow-up, significantly fewer patients in the core decompression group had experienced femoral head collapse (40.8% vs 62.3%, P = 0.011) or received THA (26.8% vs 45.3%, p = 0.022). CONCLUSIONS: Core decompression can prevent progression of asymptomatic type C ONFH according to the JIC classification, leading to better medium-term hip function and activity levels than no surgical treatment. Core decompression is recommended for early intervention against asymptomatic type C ONFH.

[Treatment of developmental dysplasia of hip by modified Sutherland pelvic osteotomy].

OBJECTIVE: To investigate the clinical results of modified Sutherland pelvic osteotomy for developmental dysplasia of hip (DDH). METHODS: Sutherland pelvic osteotomy were performed in 10 patients (11 hips) with DDH. Among them, there were 3 male (3 hips) and 7 female (8 hips) patients, aged (32 ± 8) years. During operation, arthroscopes were performed additionally to remove the existing hyperplasia tissue in the fossae ovalis and trimming acetabulum and glenoid labrum, thus to insure the better match between the femoral head and the realigned acetabulum. The change of imaging indexes were acquired by comparing the preoperative X-ray with the postoperative X-ray. The change of hip function and life quality were acknowledged according to contrast and analysis Harris hip score and Short Form 12-items Health Survey (SF-12) before and after osteotomy. RESULTS: All patients were followed up for a mean of (5.2 ± 2.3) years, the osteotomy were all union in 3 months. The acetabular head index was 71 ± 8 before operation, and 86 ± 4 after operation. The pre- and post-operative centre edge angle were (7 ± 9)° and (33 ± 9)°, sharp angle were (48 ± 4)° and (37 ± 5)°, acetabular index angle were (24 ± 8)° and (11 ± 5)° respectively. The average Harris score improved from 42 ± 13 preoperatively to 90 ± 5 postoperatively, with 100% excellent and good results. Every domains of SF-12 was improved in the different extents postoperatively, the improvement of physical component summary was more conspicuous than mental component summary. The imaging indexes, Harris and SF-12 were all improved with significant difference (all P < 0.05). CONCLUSIONS: The modified Sutherland pelvic osteotomy is effective. It could increase the load bearing capacity of hip, and improve the quality of life.

Study on the effect of T-2 toxin combined with low nutrition diet on rat epiphyseal plate growth and development.

The purpose of this study was to observe early lesions of rat epiphyseal plates and metaphysis caused by T-2 toxin and T-2 toxin combined with a low nutrition diet to determine possible pathogenic factors of Kashin-Beck disease (KBD). Ninety Wistar rats were divided into three groups. Group A was fed with a normal diet as control; group B was fed with a normal diet and T-2 toxin; and group C was fed with a low nutrition diet and T-2 toxin. The left knee specimens were collected, fixed in formaldehyde solution, stained by hematoxylin and eosin and Masson. After two weeks, the epiphyseal plate showed necrosis of chondrocytes in groups B and C. After four weeks, more obvious chondrocyte necrosis appeared. The positive rate of Lamellar necrosis in group C was significantly higher than that in groups B and A (P < 0.01). Metaphyseal trabecular bone showed sparse disorder and disruption in group C. T-2 toxin combined with a low nutrition diet could lead to more serious chondrocyte necrosis in the epiphyseal plate and disturb metaphyseal trabecular bone formation.