The safety and efficacy of intraoperative heparin in total hip arthroplasty

A single dose of unfractionated heparin (15 U/kg), administered intravenously before surgery on the femur suppresses thrombogenesis during total hip replacement. Nine hundred eighty-nine patients (1021 hips) who received one dose of intraoperative heparin with hypotensive epidural anesthesia were followed up prospectively for 3 months. Asymptomatic deep vein thrombosis assessed by ultrasound in the first 198 consecutive patients showed an incidence of 7.1% (14 of 198). The incidence of clinical deep vein thrombosis in the subsequent 791 patients was 0.88% (seven of 791). Symptomatic pulmonary embolism occurred in 0.5% (five of 989). No patients died and there was one major bleeding episode. Based on this favorable experience, intraoperative heparin appears safe and efficacious as thromboembolic prophylaxis.     

Deep vein thrombosis after total hip arthroplasty in Indian patients with and without enoxaparin

PURPOSE: To study the incidence of deep vein thrombosis in Indian patients undergoing total hip arthroplasty with or without prophylaxis, and the effect of enoxaparin on deep vein thrombosis. METHODS: The study covered a total of 50 hips in 40 patients who underwent total hip arthroplasty. Patients were assessed for deep vein thrombosis using Doppler ultrasonography. The hips were numbered and divided into 2 groups: the odd-numbered hips did not receive any thrombo-prophylaxis, whereas the even-numbered hips received 40 mg of enoxaparin subcutaneously, once a day for 2 weeks, until the time of discharge. RESULTS: Deep vein thrombosis was not found in both groups. We found wound haematomas in 9 patients (all of whom were on enoxaparin) (p<0.05), superficial infection in 2 patients (one on enoxaparin, one not), and local bruising in 4 patients (all of whom were on enoxaparin). Major haemorrhage did not occur in any of the cases. CONCLUSION: The incidence of deep vein thrombosis in Indian patients is very low compared to that in European and American patients. Enoxaparin failed to provide any advantage to the patients. It is therefore not advisable to give prophylaxis/low-molecular-weight heparin for deep vein thrombosis to patients undergoing total hip arthroplasty without any risk factors.     

Low-molecular-weight heparin and partial thromboplastin time-adjusted unfractionated heparin in thromboprophylaxis after total knee and total hip arthroplasty

Thromboprophylaxis with heparins after total hip arthroplasty (THA) and total knee arthroplasty (TKA) is well established. The aim of this study was to compare low-molecular-weight heparin (enoxaparin) with partial thromboplastin time (PTT)-adjusted, unfractionated heparin (heparin sodium). In a prospective study of THA and TKA 246 patients, physical examination and compression and duplex ultrasound were performed 1 day before and 7 and 14 days after surgery. One hundred thirty patients received 40 mg enoxaparin subcutaneously once per day. One hundred sixteen patients received 5,000 IU heparin sodium subcutaneously 3 times daily. As the PTT did not reach 40 seconds, the heparin sodium dosage was increased to 7,500 IU 3 times daily. The overall thrombosis rate was 4% (n = 10). In the enoxaparin group, the rate was 2.9% of the 70 THAs and 10% of the 60 TKAs. Thrombosis also occurred in the group that received heparin sodium: 1.8% of the THAs and 1.7% of the TKAs. For TKA, the difference between the 2 heparin groups was statistically significant. In the thromboprophylaxis of TKA, PTT-adjusted unfractionated heparins are superior to fixed doses of low-molecular-weight heparins.     

Deep vein thrombosis after total hip arthroplasty in Korean patients and D-dimer as a screening tool

Introduction  This prospective study was designed to confirm risk factors and to assess the incidence of deep vein thrombosis after total hip and surface replacement arthroplasty in Korean patients not receiving anticoagulation prophylaxis and to determine efficacy of plasma D-dimer levels as a screening test. Materials and methods  From May 2003 to August 2004, 221 consecutive patients undergoing unilateral total hip arthroplasty and hip resurfacing were evaluated. All patients underwent ultrasonography preoperatively and venography and/or ultrasonography on postoperative day 7. Plasma D-dimer levels were estimated by latex immuno-assay preoperatively and on days 3 and 7 postoperatively. Results  Of the 221 patients in our cohort, 23 developed deep vein thrombosis (10.4%). Age (r = 0.245, P < 0.001) and gender (r = 0.155, P = 0.021) significantly correlated with deep vein thrombosis. Rise in incidence paralleled increase in age (X² = 32.860, P < 0.001). D-dimer levels on postoperative days 3 (γ = 0.364, P < 0.001) and 7 (γ = 0.470, P < 0.001) were significantly correlated to the development of DVT. Conclusion  While incidence of deep vein thrombosis in Korean population after THA was lower than that in the West; it increased with age, and in female gender. Significant correlation was found between D-dimer levels and the development of deep vein thrombosis.     

Intrahepatic hemorrhage after use of low-molecular-weight heparin for total hip arthroplasty

Low-molecular-weight heparin (LMWH) has become a popular agent for prophylaxis against deep vein thrombosis and thromboembolic disease after total joint arthroplasty. LMWH allows for consistent dosing in postoperative patients without the need for laboratory monitoring. Hemorrhage is an uncommon but documented adverse reaction when using LMWH; however, intrahepatic hemorrhage has not been previously reported in conjunction with LMWH therapy. We report the case of a woman who suffered intrahepatic hemorrhage presenting with acute abdominal pain and vomiting after the use of enoxaparin for total hip arthroplasty.     

Efficacy of intraoperative autotransfusion in primary total hip arthroplasty

The role of intraoperative autotransfusion in diminishing perioperative transfusion requirements was studied in 64 patients undergoing primary total hip arthroplasty. The total transfusions administered in a 3-day perioperative period were tabulated for the study group (in which intraoperative autotransfusion was utilized) and compared to that of the control group. Despite the use of the Cell Saver autotransfusion device, no significant difference was noted between the total units of blood transfused perioperatively in the two groups. Moreover, calculations of mean perioperative blood loss (intra- and postoperative) were not significantly different, nor was there any difference in mean hemoglobin concentrations between the two groups on the third postoperative day. All 64 patients received 4 units or less of banked blood in the perioperative period. The authors conclude that this modality of blood conservation is not necessary in primary hip arthroplasty and that a well planned autologous prebanking program should be sufficient in the vast majority of cases to avoid the use of banked homologous blood.     

Low revision rate after total hip arthroplasty in patients with pediatric hip diseases

Background The results of primary total hip arthroplasties (THAs) after pediatric hip diseases such as developmental dysplasia of the hip (DDH), slipped capital femoral epiphysis (SCFE), or Perthes’ disease have been reported to be inferior to the results after primary osteoarthritis of the hip (OA).

Materials and methods We compared the survival of primary THAs performed during the period 1995–2009 due to previous DDH, SCFE, Perthes’ disease, or primary OA, using merged individual-based data from the Danish, Norwegian, and Swedish arthroplasty registers, called the Nordic Arthroplasty Register Association (NARA). Cox multiple regression, with adjustment for age, sex, and type of fixation of the prosthesis was used to calculate the survival of the prostheses and the relative revision risks.

Results 370,630 primary THAs were reported to these national registers for 1995–2009. Of these, 14,403 THAs (3.9%) were operated due to pediatric hip diseases (3.1% for Denmark, 8.8% for Norway, and 1.9% for Sweden) and 288,435 THAs (77.8%) were operated due to OA. Unadjusted 10-year Kaplan-Meier survival of THAs after pediatric hip diseases (94.7% survival) was inferior to that after OA (96.6% survival). Consequently, an increased risk of revision for hips with a previous pediatric hip disease was seen (risk ratio (RR) 1.4, 95% CI: 1.3–1.5). However, after adjustment for differences in sex and age of the patients, and in fixation of the prostheses, no difference in survival was found (93.6% after pediatric hip diseases and 93.8% after OA) (RR 1.0, CI: 1.0–1.1). Nevertheless, during the first 6 postoperative months more revisions were reported for THAs secondary to pediatric hip diseases (RR 1.2, CI: 1.0–1.5), mainly due to there being more revisions for dislocations (RR 1.8, CI: 1.4–2.3). Comparison between the different diagnosis groups showed that the overall risk of revision after DDH was higher than after OA (RR 1.1, CI: 1.0–1.2), whereas the combined group Perthes’ disease/SCFE did not have a significantly different risk of revision to that of OA (RR 0.9, CI: 0.7–1.0), but had a lower risk than after DDH (RR 0.8, CI: 0.7–1.0).

Interpretation After adjustment for differences in age, sex, and type of fixation of the prosthesis, no difference in risk of revision was found for primary THAs performed due to pediatric hip diseases and those performed due to primary OA.     

Interleukin-6 in the blood of patients with total hip arthroplasty without loosening

Patients with total hip arthroplasty were screened for the presence of proinflammatory cytokines in the systemic circulation. Only increased levels of interleukin-6 were detected in patients having had total hip arthroplasty more than 10 years ago. These increased levels of interleukin-6 were associated with a decrease in bone mineral density associated with polyethylene wear and with radiologic osteolysis in some patients. These abnormalities were not found in control subjects without total hip arthroplasty or in patients who had a prosthesis in place for less than 6 years. The elevation in interleukin-6 levels found in patients with the oldest prostheses could constitute a marker for periprosthetic osteolysis.     

Dislocation after total hip arthroplasty among patients with developmental dysplasia of the hip

The precise relationship between developmental dysplasia of the hip and dislocation among patients after total hip arthroplasty has not been well clarified. A total of 820 patients with developmental dysplasia of the hip who underwent total hip arthroplasty from January 2000 to December 2009 were categorized according to Crowe classification, and postoperative dislocation rates were analyzed among subgroups. The overall dislocation rate was 2.93%. No statistically significant differences in dislocation rates were observed between these with and without subtrochanteric osteotomy. Femoral head size was the only factor with significant difference between the dislocated and stable groups, especially when femoral head diameter increased from 28 to 32 mm. Of all dislocations, 69.6% were anterior dislocation, and the degree of cup anteversion and combined anteversion of anterior dislocators was higher than that of the posterior dislocators (P = .0082 and P = .001).     

Fluoroscopy cannot recognize intraoperative fracture in patients receiving 2-incision total hip arthroplasty

Intraoperative fluoroscopy is suggested as a standard procedure in 2-incision total hip arthroplasty. Between September 2003 and July 2004, 2-incision total hip arthroplasties were done in 18 hips with and another 18 hips without the use of fluoroscopy. In group 1, the anterior skin incision was initially limited to 5 cm. Fracture or instability was checked by fluoroscopy first and then the incision was enlarged to 8 cm for visualization. In group 2, incisions were made long enough to expose the surgical field. There were 2 femoral neck fractures in the fluoroscopy group. The fractures were linear in the anteromedial femoral neck and could not be detected by fluoroscopy. Such linear fractures if overlooked could result in serious complications such as fracture displacement or implant instability. Surgeons should not rely on intraoperative fluoroscopy to check implant stability, and visualization of the surgical field should not be compromised when doing minimally invasive approach for total hip arthroplasty.     

骨质疏松患者全髋关节置换术后股骨应力变化的有限元分析

[目的]建立骨质疏松患者全髋关节置换术后股骨三维有限元模型,分析骨质疏松患者全髋关节置换术后股骨侧应力分布,为手术操作及假体的选择提供生物力学依据。[方法]采用64排螺旋CT扫描骨质疏松患者(骨密度检查提示)行全髋置换术后数据,建立骨质疏松患者全髋关节置换术后股骨三维有限元模型。对该模型进行模拟加载及仿真计算。分析骨质疏松患者全髋置换术后股骨的应力分布特点。[结果]骨质疏松患者行髋关节置换术后股骨侧应力分布由股骨近端向远端逐渐增大,应力峰值为股骨假体末端周围皮质,主要集中在假体末端与股骨内侧骨皮质交界处。通过有限元力学分析,在骨质疏松患者行关节置换术后,假体周围力学分布在各区域存在差异,差异有统计学意义(P<0.05)。[结论]通过对骨质疏松患者行全髋关节置换术后假体周围应力分布特点的分析,在手术操作过程中,应选择远端压配型假体,假体放置需避免内外翻,以减少假体远端与股骨皮质的应力集中区。     

Dislocation after total hip arthroplasty

Dislocation is one of the most common complications after total hip arthroplasty (THA). Risk factors include neuromuscular and cognitive disorders, patient non-compliance, and previous hip surgery. Surgical considerations that must be addressed include approach, soft-tissue tension, component positioning, impingement, head size, acetabular liner profile, and surgeon experience. Recent improvements in posterior soft-tissue repair after primary THA have shown a reduced incidence of dislocation. When dislocation occurs, a thorough history, physical examination, and radiographic assessment help in choosing the proper intervention. Closed reduction usually is possible, and nonsurgical management frequently succeeds in preventing recurrence. When these measures fail, first-line revision options should target the underlying etiology. This most often involves tensioning or augmentation of soft tissues, as in capsulorrhaphy or trochanteric advancement; correction of malpositioned components; or improving the head-to-neck ratio. If instability persists, or if a primary THA repeatedly dislocates without a clear cause, a constrained cup or bipolar femoral prosthesis may be as effective as a salvage procedure.     

Adjusted subcutaneous heparin versus heparin plus dihydroergotamine in prevention of deep vein thrombosis after total hip arthroplasty

In a prospective randomized study, two different antithrombotic regimens were compared with regard to their effects on the incidence of deep vein thrombosis (DVT) in 102 patients undergoing elective total hip arthroplasty. Fifty patients (group 1) received heparin subcutaneously three times daily in doses adjusted as a function of activated partial thromboplastin time (APTT), and 52 patients (group 2) received a fixed dose of 5,000 IU heparin plus 0.5 mg dihydroergotamine twice daily. Both treatments were started 2 days before operation and continued for 7-9 days after operation, when venography of the operated leg was performed in all patients. The overall incidence of DVT was 22% in group 1 and 19.6% in group 2. Eight patients (16%) in group 1 and four (7.6%) in group 2 developed proximal DVT. These differences were not statistically significant. Hemorrhagic complications occurred more frequently in group 1. Heparin plus dihydroergotamine is a simple and effective method of preventing DVT in patients undergoing total hip arthroplasty. Daily APTT-adjusted subcutaneous heparin remains the best method of prevention of DVT in patients with contraindications to the use of dihydroergotamine and those with two or more DVT risk factors.     

Dislocation after total hip arthroplasty

Hip dislocation has long been one of the major complications after total hip arthroplasty (THA). From 1980 to 1994, we performed 2728 THAs (including primary and revision cases). There were 97 hips (3. 6%) with the complication of dislocation, 62 of which were followed up for at least 2 years (mean 5.3 years; range 2-12 years). Single dislocations occurred in 40% and recurrent dislocations in 60%. More than half of the dislocations (58%) occurred within 3 months after the index operation. The dislocation rate was not related to sex, age, previous revision surgery, or types of prosthesis, but was related to a smaller size of the femoral head. The rate of recurrent dislocation was not related to a history of previous surgery, but was related to a smaller femoral head, late onset of dislocation (> 3 months), soft-tissue imbalance, and cup malposition in both anteversion and inclination. If the size of the femoral head was 26 mm or smaller, a posterior approach was not recommended. Closed reduction followed by 1-2 weeks of skin traction was the treatment of choice. The success rate for the first attempt at closed reduction for the treatment of dislocation was 41%; the success rate decreased gradually with the number of attempts. For the recurrent dislocation group, bracing for 4-6 weeks with training was recommended for the postural type and bracing for 3 months with muscle training for the soft-tissue imbalance type. Only 15% of the dislocated hips needed re-operation, and most of the patients resolved the problem after being informed and undergoing muscle training.     

Infection after total hip arthroplasty

Total hip joint replacement offers dramatic improvement in the quality of life but deep infection is the most feared complication of this procedure. The infection threatens the function of the joint, the preservation of the limb, and occasionally even the life of the patient. For the surgeon it is a disastrous anticlimax, which follows a procedure that may have given the patient freedom from pain and increased mobility.     

Instability after total hip arthroplasty

Instability following total hip arthroplasty (THA) is an unfortunately frequent and serious problem that requires thorough evaluation and preoperative planning before surgical intervention. Prevention through optimal index surgery is of great importance, as the management of an unstable THA is challenging even for an experienced joints surgeon. However, even after well-planned surgery, a significant incidence of recurrent instability still exists. Non-operative management is often successful if the components are well-fixed and correctly positioned in the absence of neurocognitive disorders. If conservative management fails, surgical options include revision of malpositioned components; exchange of modular components such as the femoral head and acetabular liner; bipolar arthroplasty; tripolar arthroplasty; use of a larger femoral head; use of a constrained liner; soft tissue reinforcement and advancement of the greater trochanter.