Patient-related predictors of implant failure after primary total hip replacement in the initial, short- and long-terms. A nationwide Danish follow-up study including 36,984 patients.

We examined the association between patient-related factors and the risk of initial, short- and long-term implant failure after primary total hip replacement. We used data from the Danish Hip Arthroplasty Registry between 1 January 1995 and 31 December 2002, which gave us a total of 36 984 patients. Separate analyses were carried out for three follow-up periods: 0 to 30 days, 31 days to six months (short term), and six months to 8.6 years after primary total hip replacement (long term). The outcome measure was defined as time to failure, which included re-operation with open surgery for any reason. Male gender and a high Charlson co-morbidity index score were strongly predictive for failure, irrespective of the period of follow-up. Age and diagnosis at primary total hip replacement were identified as time-dependent predictive factors of failure. During the first 30 days after primary total hip replacement, an age of 80 years or more and hip replacement undertaken as a sequela of trauma, for avascular necrosis or paediatric conditions, were associated with an increased risk of failure. However, during six months to 8.6 years after surgery, being less than 60 years old was associated with an increased risk of failure, whereas none of the diagnoses for primary total hip replacement appeared to be independent predictors.

Chronic pain following total hip arthroplasty: a nationwide questionnaire study.

BACKGROUND: Chronic post-operative pain is a well-recognized problem after various types of surgery, but little is known about chronic pain after orthopedic surgery. Severe pre-operative pain is the primary indication for total hip arthroplasty (THA). Therefore, we examined the prevalence of chronic pain after THA in relation to pre-operative pain and early post-operative pain. METHODS: A questionnaire was sent to 1231 consecutive patients who had undergone THA 12-18 months previously, and whose operations had been reported to the Danish Hip Arthroplasty Registry. RESULTS: The response rate was 93.6%. Two hundred and ninety-four patients (28.1%) had chronic ipsilateral hip pain at the time of completion of the questionnaire, and pain limited daily activities to a moderate, severe or very severe degree in 12.1%. The chronic pain state was related to the recalled intensity of early post-operative pain [95% confidence interval (CI), 20.4-33.4%] and pain complaints from other sites of the body (95% CI, 20.7-32.1%), but not to the pre-operative intensity of pain. CONCLUSION: Chronic pain after THA seems to be a significant problem in at least 12.1% of patients. Our results suggest that genetic and psychosocial factors are important for the development of chronic post-THA pain.

The Danish Hip Arthroplasty Register.

In Denmark (5.3 mill. inhabitants), a national register for total hip replacements was established in January 1995. During the first 4 years, 18,222 primary total hip replacements (THR), 3,343 revisions and 6,071 follow-up examinations have been registered. During the same period, the incidence of primary THR per 100,000 inhabitants has increased from 72 in 1995 to 93 in 1998. The mean age at the primary replacement was 68 years, 59% were women and in 75% primary arthrosis was the diagnosis. An increasing use of uncemented implants has been observed both in primary THR and in revision. 64% of the primary THR were cemented and in revisions of both components, 49% were cemented. The reasons for revision were aseptic loosening in 63% of the cases followed by dislocation in 12% and deep infection in 11%. When assessed by the Harris Hip Score, primary THR and revisions resulted in a considerable improvement in pain and function, with the best results after primary operation. After 3 years, the prosthesis survival of all primary THR was approximately 97%. The lowest survival was observed in younger men with a hybrid prosthesis, usually uncemented cup and cemented stem.

Progressive Osteolysis after Porous-Coated Anatomic (PCA) Uncemented Total Hip Arthroplasty Ten-Year Results in 32 Consecutive Cases

ABSTRACT: Thirty-two primary non-cemented first generation Porous-Coated Anatomic (PCA) total hip prostheses in 31 patients were followed prospectively. The average follow-up period was 10.3 years. The median age at surgery was 53 years (range 21-65). All operations were performed by one surgeon. Preoperatively, all cases had a poor Harris Hip Score. Ten years after surgery, 95% were rated good or excellent. Progressive roentgenographical changes were observed. In particular there was severe femoral osteolysis in zones 1, 2 and 7, and extensive wear of the polyethylene liner at the two latest follow-up examinations. Wear of the polyethylene liner, up to 0.4 mm/year, was significantly correlated with osteolysis after seven years (p=0.003). Aseptic cup loosening was the reason for six of the eight failures. At 10.3 years after surgery the survival with revision as end-point was 72%. We stopped using the 1st generation PCA prosthesis after five years due to worrying roentgenographic changes. The seven and ten years results have confirmed that this prosthesis cannot be recommended for implantation. (Hip International 1999; 9: 214-20)

Synovial cysts of the hips in seronegative arthritis.

A 25-year-old woman with recurrent pronounced enlargement of the iliopsoas bursae is described; her hips were evaluated by ultrasonography and MRI. They appeared normal and communications to the iliopsoas bursae were demonstrated. During the preceding 8 years she had intermittent seronegative non-erosive arthritis of the knee and finger joints and her disease was classified as juvenile chronic arthritis.

Indomethacin for prevention of heterotopic ossification. A randomized controlled study in 41 hip arthroplasties.

The effect of indomethacin 25 mg 3 times daily during the first 2 postoperative weeks in preventing heterotopic bone formation after cemented total hip arthroplasty was investigated in a randomized, double-blind and placebo-controlled clinical trial on 57 patients. 16 patients were secondarily excluded, leaving 19 patients in the indomethacin group and 22 patients in the placebo group. Evaluated from the 3-month radiographs, 18/19 indomethacin patients developed either no or only the milder Grade 1 ossification. In contrast, 11/22 placebo patients developed Grade 2 or 3 ossifications. Our observations favor indomethacin prophylaxis for 2 weeks in cemented arthroplasty of the hip.

Migration of hydroxyapatite coated femoral prostheses. A Roentgen Stereophotogrammetric study.

We allocated randomly 27 patients undergoing 28 primary uncemented total hip replacements (THR) to receive prosthetic components of similar design with either plasma-sprayed titanium alloy (Ti) coating (n = 13) or hydroxyapatite (HA) coating (n = 15). After some exclusions, 15 of the patients (15 THR; 7 with HA- and 8 with Ti-coating) were followed by roentgen stereophotogrammetric analysis at 3, 6 and 12 months to measure migration of the femoral component. Twenty-six of the patients (26 THR) were followed clinically and by conventional radiography. All the femoral components had migrated at 3 months. From 3 to 12 months, the migration of Ti-coated components continued whereas the HA-coated components had stabilised. At 12 months there was significantly less migration of the HA-coated components (p < 0.05). The maximum subsidence was 0.2 mm in both groups. The Harris hip score was equal in the two groups preoperatively but at follow-up it was better in the HA-coated group (p < 0.05) and visual analogue scale scores showed that they had less pain (p < 0.05).

Years of potential life lost after hip fracture among postmenopausal women.

From January 1987 and onwards all cases of hip fracture in Arhus County, Denmark, were registered in a prospective multicenter investigation. Until December 1990, 2273 postmenopausal women (greater than 50 years) with first hip fractures were registered. Of these 643 sustained a hip fracture in 1988. Life tables were constructed for different age groups; the excess mortality (in comparison with the reference population) for each age group ranged from 10 to 20 percent. The years of potential life lost (YPLL) (life expectancy method) were calculated for the 1988 cohort and compared with the YPLL due to other selected conditions calculated from official vital statistics. The YPLL rates (per 1000 persons) were as follows: hip fracture 9.2, ischemic heart disease 73, cerebrovascular disease 29, breast cancer 20 and cancer of the uterus 6.7. We propose that hip fracture mortality data should be continuously registered and evaluated using the YPLL method to detect changes caused by the expected increase in the number of hip fractures.

Prevention of thromboembolism in 190 hip arthroplasties. Comparison of LMW heparin and placebo.

Prophylactic efficacy and safety of a low molecular weight (LMW) heparin against postoperative thromboembolic complications were investigated in a double-blind, randomized study. Totally, 210 consecutive patients undergoing total hip replacement were allocated to two groups. Patients in the heparin group received 50 IU anti-Xa per kilo body weight of Logiparin once daily, and patients in the placebo group received one daily injection of saline. Additional prophylaxis in all the patients was thigh-length compression stockings beginning on the day of the operation. Deep vein thrombosis was diagnosed by bilateral ascending phlebography between Days 8 and 10 after the operation. Twenty patients were excluded from the evaluation. Thirty of 93 patients in the heparin group compared with 45 of 97 patients in the placebo group suffered a thromboembolic complication during the study (P = 0.02). The postoperative blood loss and total number of blood transfusions in the heparin group were higher than in the placebo group. However, the observed differences were of no clinical importance. Adverse effects, including bleeding complications and wound hematomas, were observed in 13 heparin patients and 7 placebo patients (NS). One patient in each group died. Thrombo-prophylaxis with LMW heparin once daily was safe and more effective than the placebo in patients undergoing total hip replacement.

Biological tolerance of Logiparin, a low molecular weight heparin used in patients undergoing total hip replacement.

Two hundred ten patients scheduled for THR were randomized into two groups. Group A (105 patients) received Logiparin (Novo-Nordisk, Denmark) 50 mg/kg body weight once daily, and group B (105 patients) received placebo once daily. Injections started 2 hr preoperatively and continued for 7 days. Blood samples were collected preoperatively before medication and 3 hr after last injection on the seventh postoperative day. Two hundred three patients completed the study: 103 in group A, 100 in group B. In group A there was a significantly higher increase in ASAT (p = 0.0006) and APH (p = 0.0137) compared with group B. Significantly more patients in group A showed an increase from normal preoperative values to pathological postoperative values in ASAT (p = 0.0012) and APH (p = 0.025) compared with group B. All changes were found to be reversible within 2 weeks of termination of drug treatment. Although no conclusion about the mechanism leading to the increase in ASAT and APH is possible from this data, there is very good suggestive evidence that the liver is influenced by this agent.

Antibiotic prophylaxis in lower-extremity amputations due to ischemia. A prospective, randomized trial of cephalothin versus methicillin.

The efficiency of prophylactic antibiotic therapy in amputation surgery was studied in a prospective, randomized trial of a first-generation cephalosporin (cephalothin) compared with a narrow-spectrum beta-lactam stable penicillin (methicillin). Eighty-eight patients received cephalothin 2 g X 4 on the day of operation, while 86 patients received methicillin 1 g X 4. The patients were followed up for 21 days. Infected wounds occurred in 14.8% of the patients in the cephalothin group, compared with 14% in the methicillin group. The frequency of deep infections was 10.2% versus 4.7% (P = 0.1611). The reamputation frequency was 18.2% in the cephalothin group compared with 12.8% in the methicillin group; the frequency of below-knee reamputation was 18.4% versus 7.7% (P = 0.1469). No clostridial infections were found. The study did not demonstrate any significant difference between cephalothin and methicillin in the prophylaxis for lower-extremity amputations, although the latter drug tended to be the best choice.

Indomethacin and bone remodeling. Effect on cortical bone after osteotomy in rabbits.

Remodeling in cortical bone close to a plated tibial midshaft osteotomy was histomorphometrically evaluated in 32 rabbits. The animals were divided into two groups, one being treated with indomethacin (10 mg/kg per day) and the other receiving placebo. In the placebo-treated group, the remodeling activity was higher in the osteotomized leg compared with the intact leg. Two and 6 weeks after osteotomy, the number of resorptive and formative foci was reduced in the indomethacin-treated group compared with the placebo group. Porosity did not differ between the groups after 2 weeks; but after 6 weeks, it was reduced in the indomethacin-treated animals. Throughout the study, the bone formation rate did not differ between the two groups. This study demonstrates that indomethacin inhibits the remodeling of traumatized bone.

Comparison of three different treatments for ruptured lateral ankle ligaments.

Two hundred consecutive patients with arthrographically verified rupture of one or both of the lateral ankle ligaments were allocated to treatment with either an operation and a walking cast, walking cast alone, or strapping with an inelastic tape - all for 5 weeks. Eighty-seven percent of the patients attended follow-up after 1 year. Only 5 percent in each treatment group were unsatisfied with the result. There were no differences between the treatment groups in ankle stability or symptoms during different activities, regardless of rupture of the anterior talofibular ligament alone or combined with rupture of the calcaneofibular ligament. However, the patients treated with tape had fewer symptoms, fewer complaints when running, and more ankles recovered to the preinjury state. Therefore, in lateral ankle ligament rupture, tape bandages seem preferable.

Bone repair inhibited by indomethacin. Effects on bone metabolism and strength of rabbit osteotomies.

We measured mineral content, maximum bending strength, and regional blood flow after tibial osteotomy fixed with a small metal plate in 38 rabbits. Half of the animals were treated with indomethacin (10 mg/kg/day) while the other half served as controls. After 2 and 6 weeks, the bone mineral content and maximum bending strength were lower in the indomethacin group when compared with the controls. Compared with the controls, the blood flow at the osteotomy site was decreased after 2 weeks and increased after 6 weeks in the indomethacin-treated animals. Inhibition of blood flow increase by indomethacin medication in the early period following osteotomy, as well as retarded bone healing, are probably caused by inhibition of the inflammatory reaction.

Fibrin sealant in bone transplantation. No effects on blood flow and bone formation in dogs.

To study bone formation and regional blood flow following the use of fibrin sealant in autologous cancellous bone transplantation, a dog model was developed. In 18 dogs, a standardized defect in both tibiae was filled with an autologous iliac crest graft. On one side, the bone chips were mixed with fibrin sealant while the other side served as control. After 1, 2 and 3 weeks the blood flow of the transplant was calculated and the new bone formed evaluated histomorphometrically. Generally, the highest blood flow rates and most intensive new bone formation were observed at 2 weeks postoperatively. Fibrin sealant did not alter blood flow or new bone formation, but a tendency to diminished new bone formation was found in some grafts. Our study does not support the application of fibrin sealant in ordinary cancellous bone grafting.

Fixation of osteochondral fractures. Fibrin sealant tested in dogs.

Standardized osteochondral fractures in the left femoral condyle in 19 adult mongrel dogs were fixed with either fibrin sealant or Kirschner wire. Adaptation and mechanical strength after 4, 7 or 8, and 14 days were compared with an in vitro study of the initial strength of the fibrin sealant in osteochondral fractures. After 4 days, the maximum tensile strength was increased in the fibrin sealed group, whereas no difference in energy absorption at failure was found. Although the initial strength of the fibrin bond was low, the tendency to displacement was less in this group. Our results suggest that fibrin sealant can be used for fixation of small osteochondral fragments, provided that immobilisation is sufficient.

Early rehabilitation following osteosynthesis with the sliding hip screw for trochanteric fractures.

A prospective study of 104 patients with throchanteric hip fractures was undertaken with particular regard to postoperative complications and rehabilitation at the follow-up 3 months later. The mortality was 20%, depended more on the social function prior to the fracture than on the patient's age. Osteosynthesis was performed with the Richards sliding screw-plate system. The most frequent clinical complications were of a cardiovascular and pulmonary nature. Technical failure was encountered in 10%. Hip function was excellent or good in 69%. In 40% the ability to walk remained unchanged after the operation. Seventy-five per cent of the patients returned to their own homes, although 51% were more dependent on the social welfare system than before the fracture. The social function prior to the fracture determined the social function after the fracture to a greater extent than did the patient's age.

Instability of trochanteric hip fractures following internal fixation. A radiographic comparison of the Richards sliding screw-plate and the McLaughlin nail-plate.

A comparison was made of the McLaughlin nail plate and the Richards sliding screw-plate techniques for fixation of trochanteric hip fractures. The series included 96 patients in each group. The fractures were followed radiographically for 3 months. Technical failures were encountered in 31 per cent of the McLaughlin fractures and in 8 per cent of the Richards fractures; reoperation was performed in 9 per cent in McLaughlin vs none in the Richards fractures. The main failure was varus displacement in both groups, always combined with lateral cutting of the screw in the Richards fractures, and often combined with failure of the nail-plate junction in McLaughlin fractures. Our study has shown that the sliding screw-plate is superior to the nail plate in both stable and unstable fractures.