Comparison of the plantar pressure distribution and mechanical alignment in patients with varus knee osteoarthritis following high tibial osteotomy.

PURPOSE: The changes in the lower limb alignment were vitally important after high tibial osteotomy (HTO). Therefore, the purpose of present study was to analyze the characteristics of plantar pressure distribution after HTO, and to investigate the effect of plantar pressure distribution on postoperative limb alignment. METHODS: Between May 2020 and April 2021, varus knee patients undergoing HTO were evaluated in the present study. The peak pressure of plantar regions, medial-lateral pressure ratio (MLPR), foot progression angle (FTA), anteroposterior COP (AP-COP), lateral symmetry of COP (LS-COP), and the radiographic parameters were evaluated preoperatively and at the final follow-up. Compared among the slight valgus (SV), moderate valgus (MV) and large valgus (LV) groups at the final follow-up, the peak pressure of HM, HC and M5 regions, and the MLPR were compared; the Knee Injury and Osteoarthritis Outcome Score4 (KOOS4) including four subscales, and the American of orthopedic foot and ankle society (AOFAS) were evaluated. RESULTS: The WBL%, HKA and TPI angle changed significantly after HTO (P < 0.001). The preoperative group exhibited a lower peak pressure in the HM region (P < 0.05) and higher peak pressure in the M5 region (P < 0.05); the pre- and postoperative groups exhibited a lower peak pressure in the HC region (P < 0.05); the rearfoot MLPR was significantly lower and LS-COP was significantly higher in the preoperative group (P = 0.017 in MLPR and 0.031 in LS-COP, respectively). Comparison among the SV, MV and LV groups, the SV group indicated a lower peak pressure in the HM region (P = 0.036), and a lower MLPR in the rearfoot (P = 0.033). The KOOS Sport/Re score in the MV and LV groups increased significantly compared with the SV group (P = 0.042). CONCLUSION: Plantar pressure distribution during the stance phase in patients with varus knee OA following HTO exhibited a more medialized rearfoot plantar pressure distribution pattern than that before surgery. Compared with the small valgus alignment, a moderate to large valgus alignment allows patients to walk with a more even medial and lateral plantar pressure distribution, which is more similar to healthy adults.

Spontaneous resolution of asymptomatic alumina matrix composite ceramic liner dissociation: a case report.

BACKGROUND: Total hip arthroplasty(THA)is widely used to treat end-stage hip disorders. Ceramic-on-ceramic total hip prostheses are widely used because of their durability. Alumina matrix composite (AMC), known as the fourth-generation ceramics, reduces implant fracture and wear rate compared to their predecessors. However, ceramic acetabular liner dissociation is a complication that necessitates revision of the AMC prostheses. To date, only few cases of AMC liner dissociation have been reported and all of which have been treated with revision surgery. Therefore, the prognosis of non-operated AMC liner dissociation remains unknown so far. CASE PRESENTATION: A 57-year-old man with avascular necrosis of the femoral head was treated with THA, wherein a Pinnacle® (DePuy, J&J, Warsaw, IN) acetabular cup and AMC liner were implanted. Intraoperative examination confirmed proper seating of the liner, whereas the initial postoperative radiograph revealed liner dissociation. The patient refused surgical revision due to the absence of symptoms and was discharged and followed-up. The patient made an uneventful recovery, and radiographic follow-up at 6-month post-operation showed that the liner was re-seated to its right position. No clinical or radiographic anomaly was found at the 15-month of postoperative follow-up. CONCLUSIONS: Here, we report an unprecedented case of AMC ceramic liner dissociation with spontaneous resolution. This case shows that ceramic liner dissociation could be asymptomatic, and careful postoperative examination of the patient is important. Spontaneous resolution is possible, but the underlying mechanism and the eligible patient to benefit from it must be investigated. Before clarifying these questions, revision surgery should be the first-line treatment.

Decreased serum CXCL12/SDF-1 concentrations may reflect disease severity of non-traumatic osteonecrosis of femoral head.

OBJECTIVE: The current study was performed to investigate the potential association of serum CXCL12 with disease severity in non-traumatic ONFH. METHODS: This study enrolled 182 patients with non-traumatic ONFH and 182 age- and gender-matched healthy controls. The CXCL12 levels in serum were measured by enzyme-linked immunosorbent assay. Meanwhile, serum levels of procollagen type I (PINP) and Interleukin-33(IL-33) were also detected. The radiographic severity was determined by FICAT grade. Clinical severity was evaluated by visual analogue scale (VAS), Harris Hip Score (HHS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Among the non-traumatic ONFH, 90 patients ONFH received total hip arthroplasty, the localization and expression of the CXCL12 protein and mRNA were detected by immunohistochemistry, Western blot analysis, RT-PCR and in necrotic area and adjacent non-necrotic area from lesioned femoral neck from ONFH patients and healthy femoral head from femoral neck fracture patients. Receiver operating characteristic (ROC) curve analysis was carried out to confirm the diagnostic value serum CXCL12, PINP and IL-33 with regard to the FICAT grade. RESULTS: Serum CXCL12 levels were significantly lower in non-traumatic ONFH patients compared with healthy controls. CXCL12 mRNA and protein expressions were both significantly decreased in necrotic area in comparison with non-necrotic area and healthy femoral head. Serum CXCL12 concentrations were drastically reduced in patients with FICAT stage 4 compared with stage 3, and CXCL12 concentrations in patients with stage 3 were markedly lower than stage 2. Serum CXCL12 levels were negatively related to FICAT grading. In addition, Serum CXCL12 concentrations were also negatively related to VAS, WOMAC scores and positively correlated with HHS scores. Meanwhile, serum CXCL12 levels were positively correlated with serum PINP and negatively correlated with IL-33 levels. ROC curve analysis implicated that decrease CXCL12 in serum may act as a favorable marker for FICAT grade. CONCLUSIONS: Decreased serum CXCL12 concentrations may reflect disease severity of non-traumatic ONFH.

Incidence, Outcomes and Risk Factors of Heparin-Induced Thrombocytopenia After Total Joint Arthroplasty: A National Inpatient Sample Database Study.

Backgrounds: Heparin-induced thrombocytopenia (HIT) is a severe immune-mediated complication of heparin exposure, leading to negative consequences after total hip (THA) and knee arthroplasty (TKA). Materials and Methods: A retrospective study was conducted using the National Inpatient Sample (NIS) database from 2005 to 2014. The incidence and outcomes of HIT after THA or TKA were documented. Logistic regression analysis was performed to identify the postoperative HIT risk factors. Results: A total of 59 3045 patients who underwent THA and 1228 707 patients who underwent TKA were identified. The cumulative incidences were 0.02% and 0.01%, respectively. The HIT group presented significantly higher Charlson Comorbidity Index and Elixhauser Comorbidity Index scores, longer hospital stays (LOS), and higher medical costs. HIT led to a significantly higher mortality rate after THA (2.17% vs 0.16%, P = .0091). In THA, the HIT risk factors were racial minority, AIDS, pulmonary circulation disorders (PCD), psychoses, and hypertension. In TKA, the HIT risk factors were racial minority, PCD, and weight loss. Conclusion: The incidence of HIT after THA and TKA is relatively low; however, HIT significantly increases inpatient mortality, LOS, and medical cost.

Patients Undergoing Primary Total Joint Arthroplasty with Primary Hypercoagulable States.

OBJECTIVE: To analyze perioperative complications, resource consumption, and inpatient mortality of patients who receive total joint arthroplasty (TJA) with a concomitant diagnosis of a primary hypercoagulable state (PHS). The following questions were posed in the present paper. First, do patients undergoing TJA with PHS have increased risk of deep venous thrombosis (DVT), pulmonary embolism (PE), and periprosthetic joint infection (PJI)? Second, what other in-hospital complications are more likely among PHS patients undergoing TJA? Third, do TJA patients with PHS usually consume greater in-hospital resources? Fourth, do PHS patients suffer higher mortality rates compared to non-PHS patients? Finally, have PHS patients received proper anticoagulant management in past arthroplasties? METHODS: The National Inpatient Sample (NIS) database for the years between 2003 and 2014 was searched to identify patients undergoing primary TJA. Patients with PHS were identified with the ICD-9-CM code 289.81. The χ2 -test, the Pearson test, and adjusted multivariate regression analysis were performed to evaluate the difference and odds ratios between the positive and negative diagnosis groups. RESULTS: From 2003 to 2014, a total of 2,044,356 patients were identified in the NIS as undergoing primary total hip arthroplasty (THA) or total knee arthroplasty (TKA) in the United States. A total of 4664 patients (0.2%) were identified as having PHS. Compared with the non-PHS group, TJA patients with PHS had a higher risk of DVT (THA: odds ratio [OR] = 8.343, 95% CI: 5.362-12.982, P < 0.001; TKA: OR = 4.712, 95% CI: 3.560-6.238, P < 0.001) but did not have increased risk of PE (THA: OR = 1.306, 95% CI: 0.48-3.555, P = 0.602; TKA: OR = 1.143, 95% CI: 0.687-1.903), and only PHS patients in the THA group had higher risks of inpatient mortality (OR = 3.184, 95% CI: 1.348-7.522, P = 0.008) and periprosthetic joint infection (OR = 3.343, 95% CI: 1.084-10.879, P = 0.036). In addition, PHS patients had extended length of stay, higher total costs, and increased risks of certain other complications, such as peripheral vascular disease, hemorrhage, and thrombophlebitis. CONCLUSION: In the present study, PHS patients had higher risks of DVT, greater in-hospital resource consumption, and certain other perioperative complications. However, PHS was not associated with increased risk of PE in TJA patients in the United States between 2003 and 2014. While potential hazards of PHS have already been recognized, the present study revealed additional concerns and demonstrated that further improvements in the perioperative management of patients with hereditary hypercoagulable disorders are essential.

Outcomes following Revision Total Knee Arthroplasty Septic versus Aseptic Failure: A National Propensity-Score-Matched Comparison.

Although periprosthetic joint infection (PJI) has been hypothesized to increase the risk of complications following revision total knee arthroplasty (TKA), strong evidence linking the two is lacking. The aim of this study was to determine whether PJI is an independent risk factor for inpatient perioperative complications, and increased resource use in patients undergoing revision TKA. We relied on the US Nationwide Inpatient Sample (NIS) to identify patients with PJI or non-PJI treated with revision TKA between 2002 and 2014. Overall, 5,316 (16.4%) and 27,033 (83.6%) patients were categorized as PJI and non-PJI, respectively. To adjust for potential baseline differences between the two groups, propensity-score-based matching was performed. This resulted in 5,187 (50%) PJI patients matched to 5,187 (50%) non-PJI patients. The rates of postoperative complications, blood transfusions, prolonged length of stay (pLOS), in-hospital cost, and in-hospital mortality were assessed for both groups. Multivariable logistic regression analyses were performed within the cohort after propensity-score matching. For PJI versus non-PJI, respectively, the following rates were recorded: blood transfusions, 28.3 versus 18.4% (p < 0.0001); postoperative complications, 27.5 versus 19.8% (p < 0.0001); pLOS (>4 d), 61.9 versus 26.9% (p < 0.0001); in-hospital cost (>$39,929), 55.8 versus 44.2% (p < 0.0001); in-hospital mortality, 0.6 versus 0.3% (p = 0.016). In multivariable logistic regression analyses, PJI patients were more likely to receive a blood transfusion (odds ratio [OR]: 1.78; p < 0.0001), to experience postoperative complications (OR: 1.56; p < 0.0001), to have a higher in-hospital cost (OR: 1.65; p < 0.0001), to have a pLOS following surgery following surgery (OR: 4.69; p < 0.0001), and to have a higher in-hospital mortality (OR: 2.14; p = 0.019). After adjustment for potential selection biases, PJI is associated with more adverse perioperative outcomes and resource use than non-PJI patients. This is a Level II (level of evidence), prognostic study.

Injection route affects intra-articular hyaluronic acid distribution and clinical outcome in viscosupplementation treatment for knee osteoarthritis: a combined cadaver study and randomized clinical trial.

The coverage of hyaluronic acid (HA) on the impaired cartilage should be the precondition to exert its beneficial effect on knee osteoarthritis (KOA) according to the pharmacological mechanism. However, the intra-articular distribution of HA might be correlated with the route of drug delivery. Forty-two cadaver knees with radiographic evidence of osteoarthritis were given anteromedial (AM) or medial midpatellar (MMP) injection of HA (molecular weight 600-1500 kD) followed by gait stimulation. Although 2.5 ml HA delivered through both routes failed to cover the entire cartilage, HA covered 96.12% cartilage of patellofemoral joint (PFJ) and 71.44% of medial femorotibial joint (FTJ) through MMP route, whereas mainly distributed into FTJ and posterior condyles through AM route. HA in the MMP group distributed more in PFJ than that in the AM group (P < 0.001), but no significant difference presented in medial FTJ (P = 0.084). The clinical efficacy was also associated with the route of drug delivery. One hundred patients with unilateral mild-to-moderate KOA were recruited and randomly assigned to receive five weekly HA injections with AM route (n = 50) or MMP route (n = 50). Patients in the MMP group obtained better improvement in WOMAC index total score, pain score, stiffness score, and Lequesne index total score over the entire follow-up period, as compared to patients in the AM group (all P < 0.01). More patients in the MMP group claimed pain relief (71.7%, P = 0.024) and felt satisfying (63.1%, P = 0.007) than in the AM group at the end of follow-up. Therefore, intra-articular HA injection through MMP route is recommended in treating mild-to-moderate KOA. Graphical Abstract .

Revision total hip arthroplasty in patients with femoral bone loss using tapered rectangular femoral stem: a minimum 10 years' follow-up.

BACKGROUND: Revision total hip arthroplasty (THA) remains a significant challenge when there is severe femoral bone loss. The purpose of this study was to evaluate the clinical and radiographic outcomes of revision THA in patients with femoral bone loss treated with Zweymüller SLR-Plus stem. METHODS: A retrospective review of 82 patients who underwent revision THA using tapered rectangular femoral stem between 1997 and 2007 was undertaken. Of the 82 patients, 9 patients were lost to follow-up and were excluded from the study. The most common reason for revision was aseptic loosening (92%), periprosthetic femur fracture (5%), and infection (3%). Bone loss was categorised preoperatively according to the Paprosky classification. The mean clinical follow-up was 14 years (range 10-19 years). Their mean age at the time of index surgery was 54.7 ± 15.3 (range 30-82) years. RESULTS: The mean Harris Hip Score was significantly improved at final follow-up (68.1 ±10.3) compared with that before the revision surgery (30.4 ± 7.7) (p < 0.0001). Of the 75 stems, 69 (92%) stems were radiographically stable at the last evaluation. Among the 69 stems, 64 hips (85%) had radiographic evidence of bone ingrowth and 5 (5%) had stable fibrous fixation of the stem. Among the 7 hips that were re-revised, 5 hips were re-revised for aseptic loosening, whereas 2 were re-revised for an infection. Kaplan-Meier survivorship analysis, with removal of the stem for any cause as the endpoint, revealed that the 15-year rate of survival of the components was 90% (95% CI, 0.83-0.97). CONCLUSION: Revision THA in patients with proximal femoral bone loss using Zweymüller SLR-Plus stem led to a high rate of osseointegration of the stem and good clinical results at long-term follow-up.

Venous Thromboembolic Events after Total Knee Arthroplasty: Which Patients Are at a High Risk?

Venous thromboembolism (VTE; deep venous thrombosis and pulmonary embolism) is a known complication following primary total knee arthroplasty (TKA). The aim of this study was to investigate the trends of the incidence of VTE after primary TKA and identify associated risk factors for the occurrence of VTEs in a large cohort of TKA patients. We performed a retrospective study in which the Nationwide Inpatient Sample (NIS) database was used to identify all patients who underwent primary TKA over a period of 13 consecutive years (between 2002 and 2014) in the United States. The occurrence of a symptomatic VTE was identified with the use of ICD-9-CM (International Classification of Diseases, Ninth Revision, Clinical Modification) diagnosis codes. A total of 1,460,901 primary TKA procedures were identified in the NIS from 2002 to 2014, and 12,944 of these patients were recorded as having 13,855 VTEs, consisting of 7,609 deep venous thromboses (0.52%) and 6,246 pulmonary emboli (0.43%). The overall VTE incidence in patients undergoing TKA in the United States from 2002 to 2014 was 0.89%. Patient-related risk factors for VTEs include an older age (odds ratio [OR]: 1.44; 95% confidence interval [CI]: 1.31-1.59), black race (OR: 1.34; 95% CI: 1.25-1.44), and Medicare insurance (OR: 1.18; 95% CI: 1.13-1.22). Most of the comorbidities were associated with an increased risk of VTE following TKA. Particularly, cardiac arrhythmias, coagulopathy, fluid and electrolyte disorders, pulmonary circulation disorders, and weight loss increased the risk of VTE by more than twofold. After adjusting for confounders, VTE was associated with a longer hospital stay (2.81 ± 0.02 day), increased costs (US$14,212.16 ± US$255.64), and higher mortality rate (OR: 13.04; 95% CI: 11.08-15.35). This nationally representative study of inpatients in the United States identified several independent risk factors for VTE perioperatively in TKA patients and provided evidence that VTE patients after TKA are likely to have worse results than non-VTE patients with regard to the length of hospital stay, hospital costs, and inhospital mortality. This is a level III, prognostic study.

Efficacy of platelet-rich plasma in arthroscopic repair for discoid lateral meniscus tears.

BACKGROUND: To evaluate the clinical results of arthroscopic repair with or without platelet-rich plasma (PRP) for tears of the discoid lateral meniscus (DLM). METHODS: Twenty-nine patients with DLM tears within a stable knee were arthroscopically treated with meniscal suture repair. Of those, 14 were augmented with platelet-rich plasma (PRP), and 15 were performed without PRP augmentation. Patients were evaluated at baseline (the day before surgery) and then 12 and 24 months after the last injection. Evaluation included the Lysholm score, and Ikeuchi grade, Visual analogue score (VAS) for pain and failure rate. Failure was defined by patients developing symptoms of joint line pain, locking, swelling or requiring repeat arthroscopy. RESULTS: There was no difference in the failure rate in the PRP group (1 of 14) compared with the non-PRP group (2 of 15) (P = 0.58). Statistically significant improvement in Lysholm score, Ikeuchi grade and VAS for pain was documented at the last follow-up compared with baseline in both PRP and non-PRP group. No significantly difference was found between the PRP group and non-PRP group on Lysholm score, Ikeuchi grade and VAS for pain at the last follow-up. In the univariate analysis of each variable, younger age (P = 0.036) and longer follow-up duration (P = 0.043) were statistically associated with a better function improvement. Whereas in multivariate analysis, only younger age (P = 0.004) was significantly associated with a better function improvement. CONCLUSION: With regard to clinical evaluations in arthroscopic repair for DLM tears, PRP group had similar effect in pain relief and functional improvement to non-PRP group at mid-term follow-up. Future larger prospective studies with a longer follow-up are needed to determine whether PRP should be used with DLM repair.

Efficacy and Safety of Hylan versus Hyaluronic Acid in the Treatment of Knee Osteoarthritis.

The purpose of this study was to use meta-analytic approach to compare the efficacy and safety of intraarticular hylan and hyaluronic acid (HA) for knee osteoarthritis (OA) treatment. We searched PubMed, Embase, and the Cochrane databases through July 2017 to identify Level I randomized controlled trials (RCTs) that evaluated clinical efficacy and safety of hylan compared with HA for knee OA. The primary outcomes were Visual Analogue Scale (VAS) for pain and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain, and WOMAC function scores. In each study and for the outcome measures (VAS for pain, WOMAC pain, function and stiffness scores, and Lequesne score), we calculated the treatment effect from the difference between the preintervention and postintervention changes in the hylan and HA groups. Twenty-one RCTs involving 3,058 patients were included. Pooled analysis suggested that compared with HA, hylan was associated with similar pain relief and function improvement in patients with knee OA (VAS for pain: mean difference [MD], -3.04; 95% confidence interval [CI], -9.13 to 3.04; p = 0.33; I 2 = 76%. WOMAC pain score: MD, 0.23; 95% CI, -0.25 to 0.70; p = 0.35; I 2 = 0%. WOMAC function score: MD, -0.47; 95% CI, -6.81 to 5.88; p = 0.88; I 2 = 84%). No significant difference was found comparing the patients with treatment-related adverse events. The relationship was robust in sensitivity analysis and consistent in most of the subgroup analyses. As to the primary outcomes (WOMAC pain, function scores, VAS for pain), the difference between hylan and HA did not reach the previously reported minimum clinically important difference (MCID) values (-13.4 for VAS for pain, -2.0 for WOMAC pain score, -7.7 for WOMAC function score). Our meta-analysis showed that there were no statistically and clinically significant differences in pain relief and function improvement between hylan and HA injections for knee OA treatment. In view of its higher costs, we discourage the use of hylan in patients with knee OA in clinical practice. The level of evidence is I, meta-analysis of Level I studies.

An evidence-based etiology study of synovial cyst of knee cruciate ligament: a real or pseudo-cyst.

PURPOSE: Synovial cyst of knee cruciate ligament (SCKCL) is a rare condition but can cause severe knee pain. The understanding of its etiology is relatively poor. This current study aimed to elucidate the pathogenesis of SCKCL based on a series of histo- and cytopathological examination. METHODS: Ten SCKCL patients who underwent arthroscopy were enrolled, among five patients claimed past knee injury. Hematoxylin & eosin staining was conducted to the cyst wall tissue sections and Papanicolaou staining to the cyst fluid smear. Prussian blue staining was employed to both the wall section and fluid smear. Immumohistochemical staining for mesothelial cells (MC), epithelial cells (CK), vascular endothelial cells (CD31), monocytes (CD68), and hematogenous stem cells (CD117) were taken to elucidate the possible involvement of various cell types in the development of SCKCL. RESULTS: No erythrocyte was discovered in the fluid; however, Prussian blue stained hemosiderin particles were found in the cyst wall and fluid, suggesting past hemorrhage in all patients. Abundant lymphocytes and plasmocytes were observed in the cyst wall and fluid. In addition, the cyst lining was infiltrated with abundant CD68(+) monocytes while only few MC(+) mesothelial cells were sporadically observed in four samples. The cyst submucosa was also diffused with abundant CD68(+) monocytes and proliferated capillaries stained with CD31. CD117-positve hematogenous stem cells were sporadically observed in eight specimens. CONCLUSION: Our findings provided evidence that SCKCL is not a mature synovial cyst but rather an inflammatory pseudo-cyst. It may have resulted from past minor hemorrhage and intra-ligament chronic inflammation.

Blood loss of total knee arthroplasty in osteoarthritis: an analysis of influential factors.

BACKGROUND: Total knee arthroplasty is regarded as the most effective treatment for severe knee osteoarthritis. The influential factors of blood loss in total knee arthroplasty remain controversial. The study aims to explore the influential factors of blood loss in total knee arthroplasty comprehensively. MATERIAL AND METHODS: Three hundred and four osteoarthritis patients undergoing unilateral primary total knee arthroplasty were enrolled. Demographic characteristics, laboratory results, surgical protocol, and hemostatic and anticoagulation drugs were collected. Estimation of blood loss was calculated using the Gross equation. Multivariable stepwise linear regression analysis was performed to find out the influential factors. RESULTS: Total blood loss reached the biggest volume (1346 ± 671 mL) in the post-operative third day. Hidden blood loss reached 465 ± 358 mL. Gender, tranexamic acid, prosthesis type, and drainage were proven to be positively correlated with the total blood loss (all P < 0.05). Male appeared to suffer more surgical blood loss than female. Posterior cruciate stabilizing prosthesis might lead to more surgical blood loss than posterior cruciate retaining prosthesis. Tranexamic acid could effectively reduce total blood loss while drainage might increase bleeding. Gender and anticoagulation drugs were correlated with hidden blood loss (both P < 0.05). Low molecular weight heparin resulted in less hidden blood loss than rivaroxaban. CONCLUSIONS: Posterior cruciate retaining prosthesis and topical use of tranexamic acid were preferred to reduce total blood loss. Drainage was not recommended due to the risk of increasing bleeding. Low molecular weight heparin was recommended to prevent venous thrombosis.

The Application of Thromboelastography in Understanding and Management of Ecchymosis After Total Knee Arthroplasty.

BACKGROUND: Ecchymosis is a common complication after total knee arthroplasty (TKA). However, only a few studies have been conducted to determine the coagulation status of these patients. Using thromboelastography (TEG), a new technique recording the viscoelastic changes of a whole-blood sample, this study was performed to understand the ecchymosis-related coagulation status and its risk factors. METHODS: Seventy-five patients receiving unilateral TKA were recruited in this observational study. Oral rivaroxaban was applied as prophylaxis treatment after surgery. TEG was performed 1 day before surgery and 4 days after surgery. Total blood loss and hidden blood loss were recorded and calculated. Univariate and multivariate analyses were conducted to determine risk factors. RESULTS: Twenty-five patients (33.3%) developed ecchymosis within 2-3 days after TKA. Compared with the baseline before TKA, the α-angle (P = .032) and calculated coagulation index (CI; P = .012) were increased in non-ecchymosis group, whereas in the ecchymosis group, there was no significant difference regarding any variable of postoperative TEG evaluation. The ecchymosis group exhibited more hidden blood loss (P = .007) and total blood loss (P = .011). Value change of CI (OR = 0.666, 95% confidence interval = [0.496, 0.895], P = .007) and hidden blood loss (OR = 1.008, 95% confidence interval = [1.002, 1.013], P = .004) were recognized as the independent risk factors for postoperative ecchymosis. CONCLUSION: In TEG evaluation, the value change of CI and hidden blood loss are independent risk factors of ecchymosis. In view of the relative hypocoagulation status, it is reasonable to stop anticoagulation therapy in patients with excessive ecchymosis. Personalized anticoagulation therapy may be helpful for managing ecchymosis after TKA.

N-terminal telopeptides of type I collagen and bone mineral density for early diagnosis of nonunion: An experimental study in rabbits.

BACKGROUND: The diagnosis and treatment of bone nonunion have been studied extensively. Diagnosis and treatment of nonunion are mainly performed based on the interpretation of clinico-radiographic findings, which depend on the clinician's experience and the degree of bone callus formation during the fracture-healing process. However, resolution may be compromised when the bone mineral content is <25%. A feasible method of monitoring bone-healing is therefore needed. We monitored a rabbit model of bone nonunion by regular radiographic examinations, QCT detection, and biomarker concentrations. MATERIALS AND METHODS: Twenty purebred New Zealand rabbits (10 male and 10 female, 5-6 months of age, 2.5-3.0 kg) were divided into bone defect Group (I) that 10 left radius bones underwent resection of 1.5 cm of mid-radius bone and bone fracture Group (II) that another 10 left radius bones underwent only mid-radius fracture. Quantitative computed tomography detection of bone mineral density (BMD) and serum markers of bone formation (osteocalcin [OC], bone-specific alkaline phosphatase) and bone resorption (C- and N-terminal telopeptides of type I collagen (NTX) and tartrate-resistant acid phosphatase 5b) were assayed. There are twenty rabbits (10 male and 10 females). The age was 5-6 months weighing 2.5-3.0 kg). The defect was created in middle 1/3 radius in 10 rabbits and fracture was created in middle 1/3 radius of 10 rabbits. RESULTS: BMD and NTX concentrations were significantly lower at 5 weeks postoperatively compared to the preoperative values and were significantly different between the two groups. OC showed no significant difference before and after surgery. CONCLUSIONS: BMD and NTX concentrations may be useful for early detection of bone nonunion in rabbits.

Serum N-terminal telopeptide of type I collagen as an early marker of fracture nonunion in rabbits.

The aim of the present study was to establish an experimental animal model of fracture nonunion, and to investigate the changes in serum biomarker concentrations in fracture nonunion. A total of 20 purebred New Zealand rabbits were divided into two group: A bone defect group and a bone fracture group. In the bone defect group, a 15-mm section of bone (including the periosteum) was removed from the mid-radius, and the medullary cavities were closed with bone wax. In the bone fracture group, the mid-radius was fractured. X-rays were taken and blood samples were collected preoperatively and at 2, 3, 4, 5, 6, 7, 8, 10 and 12 weeks after the surgical procedure. The serum concentrations of osteocalcin (OC) and bone-specific alkaline phosphatase (BSAP) served as markers of bone formation, and those of C-terminal telopeptide of type I collagen (CTX), N-terminal telopeptide of type I collagen (NTX) and tartrate-resistant acid phosphatase 5b (TRACP 5b) served as markers of bone resorption. The concentration levels of the markers were measured using a biotin double-antibody sandwich enzyme-linked immunosorbent assay. In the bone defect group, bone callus was observed on X-ray at 2 weeks in three rabbits and the bone calluses stabilized at 5 weeks; however, none of the bones had healed at 8 weeks. In the bone fracture group, the fracture line was distorted at 2 weeks and bone calluses formed at 6-8 weeks. In the bone defect group, the serum BSAP and TRACP 5b concentrations increased following the surgical procedure, peaked at 4 weeks, began to decrease at 5 weeks and stabilized after 6 weeks. The serum OC concentrations did not change significantly following the surgical procedure. The serum CTX concentrations fluctuated during the first 4 weeks, peaked at 5 weeks, then decreased and stabilized after 6 weeks. The serum NTX concentrations fluctuated during the first 4 weeks, were significantly lower at 5 weeks compared with the other time points and stabilized after 6 weeks. These results suggested that a bone nonunion model can be established in New Zealand rabbits by resecting a 15-mm section of bone from the mid-radius prior to bone wax blocking. Measurement of the serum BSAP, CTX, NTX, and TRACP 5b concentrations may be useful for the early detection of bone nonunion. The serum NTX concentrations changed significantly in rabbits with bone nonunion. Further studies are required in order to determine the feasibility of using serum NTX concentrations for the early diagnosis of bone nonunion.

Cementless revision for infected hip arthroplasty: an 8.6 years follow-up.

OBJECTIVE: To investigate cementless revision for postoperative infection after total hip arthroplasty (THA). METHODS: From November 1997 to December 2009, 10 patients (10 hips; four males, six females) of mean age 58 years (36-73 years) with infection after THA were treated. Six of the 10 hips underwent revision total hip arthroplasty, two only received new acetabular components and two underwent stem revision. One-stage revision was performed in six cases and two-stage revision in four. Consecutive radiographs were compared to evaluate component conditions. Harris hip scores were determined before surgery and at final follow-up. Erythrocyte sedimentation rate and C-reactive protein were assessed. RESULTS: All patients were followed up for a mean duration of 8.6 years (6.5-15.6 years). The mean Harris hip score improved from 35 (18-63) points preoperatively to 89 (60-99) points at final follow-up. No re-infection occurred. Femoral component exsertion was occurred in one asymptomatic patient. Hip joint pain resolved in seven cases; three patients had mild pain when walking long distances. At final follow-up, six patients still had slight limps. Heterotopic ossification developed in two hips. Mean polyethylene liner wear was 0.08 mm per year at final follow-up. Deep vein phlebothrombosis and nerve injury did not occur. CONCLUSION: One- or two-stage revisions using cementless prosthesis can produce satisfactory clinical outcomes in patients with infection after THA. Whether the original prosthesis can be partially retained when attached tightly to the femur or acetabular bone needs further investigation.

[Case-control study on effect of rivaroxaban on the risk of hidden bleeding after total hip arthroplasty].

OBJECTIVE: To investigate the risk of hidden blood loss about applying rivaroxaban after total hip arthroplasty. METHODS: From October 2009 to May 2012,88 patients with femoral head necrosis were treated with primary total hip arthroplasty. All the patients were divided into Rivaroxaban group(44 cases)and control group(44 cases). There were 25 males and 19 females in the Rivaroxaban group, with an average age of (58.48 +/- 15.19) years old; in the control group,24 patients were male and 20 patients were female, with an average age of (61.11 +/- 13.54) years old. The patients in the Rivaroxaban group took Rivaroxaban orally from the first day after operation with a dose of 10 mg each day, and treatment course was 14 days. The patients in the control group took placebo orally at the same time. Dominant blood loss and transfusion were recorded, blood routine examinations were taken before operation and at 3 days after operation. The total blood loss and hidden blood loss were calculated according to the formula. RESULTS: The mean total blood loss was (1509.56 +/- 325.23) ml and the hidden blood loss was(581.47 +/- 215.01) ml, accounting for (37.88 +/- 10.42)% in the Rivaroxaban group. The mean total blood loss was (1262.30 +/- 397.95) ml and the hidden blood loss was (395.59 +/- 97.33) ml, accounting for (30.62 +/- 0.20)% in the control group. The total blood loss, hidden blood loss and transfusion in the Rivaroxaban group was significantly more than those in control group,b ut there was no significant difference on dominant blood loss between two groups. CONCLUSION: Rivaroxaban increased the overall bleeding risk of total hip arthroplasty, especially hidden bleeding risk, which should be careful used.

The geometry of the bone structure associated with total hip arthroplasty.

Close adaptation of the prosthesis to the bone is the key to achieving optimal stability and fixation for total hip arthroplasty (THA). However, there have been no adequate studies of bone morphology, especially in different races. The aim of this study was to analyze the geometry of the acetabulum and proximal femur of people from South China, based on three-dimensional reconstruction, and to detect differences between different population subsets. CT scans were performed on 80 healthy volunteers (160 hips) from South China, comprising 40 males (80 hips) and 40 females (80 hips). The images were imported into Mimics 10.01 to perform 3D reconstruction. THA-associated anatomical parameters were measured and compared with other published data. In comparison with published data, it seemed that people from South China have smaller acetabular abduction angle, larger acetabular supro-inferior diameter, larger neck-shaft angle, smaller offset, thinner femoral shaft and more proximal isthmus, which needed to be further confirmed. There were significant differences between the genders in most parameters. As significant differences in canal flare index (CFI) and distal canal flare index (DCFI) were found between genders, it was concluded the most significant differences lay in the isthmus of the femur. Among the femora, according to Noble's classification we identified more normal types and fewer stovepipe and champagne-flute types than expected from the literature, indicating that uncemented prostheses would be suitable for most people from South China. Our findings reveal that simply choosing the smallest of a series of prostheses would not necessarily provide a good fit, due to the different trends from the proximal to the distal part of the femur. Significant variation exists in THA-associated anatomy between genders and population subsets. It is therefore imperative that each patient receives individual consideration rather than assuming all patients have the same anatomy, especially for different races.