Comparative ultrasound evaluation of human trabecular bone graft properties after treatment with different sterilization procedures.

New sterilization methods for human bone are likely to affect the mechanical properties of human cancellous grafts. These mechanical properties dictate the short- and mid-term results of the orthopedic procedure. The aim of this study was to compare the effects on bone mechanical properties, as assessed by ultrasound velocity, of different sterilization methods used under similar conditions: bleach and sublimation, humid heat, successive baths of physiological saline with osmotic detersion, and CO(2) in the supercritical phase. Alterations in mechanical properties were small with CO(2) (velocity change: -2%) and humid heat (-2.5%). Osmotic detersion had a significant but moderate effect (-4.7%). The -9% change with the protocol involving bleach suggested a greater than 30% decrease in load to failure, based on earlier studies. Gamma irradiation of defatted trabecular allografts, in a dose of 10 or 25 KGy, produced no significant changes in ultrasound velocity. Powerful protein denaturants used in sterilization protocols substantially alter the mechanical resistance of the grafts, which may jeopardize the orthopedic procedure.

Effects of gamma irradiation on mechanical properties of defatted trabecular bone allografts assessed by speed-of-sound measurement.

New sterilization methods for human bone allografts may lead to alterations in bone mechanical properties, which strongly influence short- and medium-term outcomes. In many sterilization procedures, bone allografts are subjected to gamma irradiation, usually with 25 KGy, after treatment and packaging. We used speed-of-sound (SOS) measurements to evaluate the effects of gamma irradiation on bone. All bone specimens were subjected to the same microbial inactivation procedure. They were then separated into three groups, of which one was treated and not irradiated and two were exposed to 10 and 25 KGy of gamma radiation, respectively. SOS was measured using high- and low-frequency ultrasound beams in each orthogonal direction. SOS and Young modulus were altered significantly in the three groups, compared to native untreated bone. Exposure to 10 or 25 KGy had no noticeable effect on the study variables. The impact of irradiation was small compared to the effects of physical or chemical defatting. Reducing the radiation dose used in everyday practice failed to improve graft mechanical properties in this study.

[Prevention of heterotopic ossifications in hip arthroplasty: effectiveness of selective Cox-2 inhibitors (celecoxib) versus ketoprofen]. / Comparaison célécoxib versus kétoprofène pour la prévention des ossifications péri-prothétiques de hanche.

PURPOSE OF THE STUDY: Peri-prosthetic ossifications are a frequent complication of total hip arthroplasty, which, if effective preventive measures are not taken, occur in 60% of patients. Numerous classic antiinflammatory agents have shown their preventive efficacy. New selective Cox-2 inhibitors offer the possibility of reducing the adverse effects of antiinflammatory drugs but remain to be proven effective in this indication. The purpose of this pilot study was to compare the efficacy of celecoxib versus ketoprofen. MATERIAL AND METHODS: In order to obtain sufficient statistical power to have a 70% chance of detecting a 25% difference between the two treatments with a 5% risk of error, we evaluated the incidence of peri-prosthetic ossifications of the hip in a prospective monocentric series of 52 patients receiving 400 mg celecoxib a day during a week. It was compared with the incidence in a control series of 52 matched patients (same age, gender, diagnosis, operator experience) given 200 mg ketoprofen iv for 48 hr then 300 mg po for 5 days as preventive treatment. Ossifications were studied on the plain AP view of the pelvis at a mean follow-up of more than 11 months (11.4 vs 11.9). The Brooker classification was determined. RESULTS: The percent of patients presenting peri-prosthetic ossifications was equivalent. For the celecoxib group, 60% of the patients were free of ossifications; 28.9% presented stage 1 ossification and 11.1% stage 2 ossification; none of the hip exhibited a higher stage. In the ketoprofen control group, 53.2% of patients were free of ossification, 38.2% had stage 1 ossification, 6.4% stage 2, and 2.1% stage 3; there was no patient with stage 4. Fisher's exact test did not demonstrate a significant difference between the groups (p<0.51). Compared with an older series of patients who were not given preventive treatment, there was a significant reduction in incidence of peri-prosthetic ossification (p=0.014). DISCUSSION: The two study groups were not significantly different for age, gender, or underlying disease. There were an equivalent number of cases of intolerance to treatment in the two groups. CONCLUSION: These findings appear to indicate an equivalent efficacy for celecoxib and ketoprofen for the reduction of peri-prosthetic ossifications. Based on these results, a randomized prospective comparative study can be undertaken without risk of losing effective prevention in one group. This prospective study should enable a more precise evaluation of treatment equivalence and quantify any potential gain in morbidity obtained with celecoxib.

Effect of different sterilization processing methods on the mechanical properties of human cancellous bone allografts.

Use of new sterilization methods applied to human bone is likely to affect both the mechanical and biological properties of human cancellous grafts. The mechanical properties of the transplanted bone inevitably determine the short- and mid-term results of the orthopedic procedure performed. The aim of this study was to compare, under similar conditions, the mechanical effects of gamma irradiation, lipid extraction, and treatment with 6M urea on trabecular bone samples, through conventional mechanical tests and measurement of the ultrasound wave propagation rate. Deteriorations measured for gamma irradiation and lipid extraction were low: 2.4% and 2.5%, respectively, for ultrasound propagation wave measurements. They were clearly significant for protocol including 6M urea, corresponding to a loss of 30% in values measured in the control sample for the stress to failure, inciting prudence when grafted bone is used for support in orthopedic assembly. High consistency in the results obtained between travel time of the ultrasound wave, easily done, and measurement of stress to failure through conventional tests, favor the use of ultrasound protocol, described as a quality test performed on bone grafts in the tissue bank before distribution and implantation.

Blood loss in total hip arthroplasty for rapidly destructive coxarthrosis.

We studied the perioperative blood loss in 100 total hip arthroplasties performed for rapidly destructive coxarthrosis and compared it with the blood loss in 100 total hip arthroplasties for regular coxarthrosis. The treatment protocol was identical in both groups. Total blood loss was calculated as the compensated blood loss (volume transfused during and immediately after surgery) and the non-compensated blood loss using Nadler and Mercuriali formula. The mean blood loss calculated in milliliters of red blood cells (100% haematocrit) was 578 ml in regular coxarthrosis and 945 ml in rapidly destructive coxarthrosis. The blood loss after total hip arthroplasty is greater when surgery is performed for rapidly destructive coxarthrosis than for regular coxarthrosis (P < 0.001).

[Bone allografts in orthopedic surgery: current concepts]. / Le point sur les homogreffes osseuses.

In the last decade, indications for bone allografting in orthopedic surgery have progressively increased, related to, on the one part, treatment of benign or malignant tumors, but, on another (major) part, to treatment of major bone defects due to loosening of hip or knee total prostheses. In France, legislation and control concerning donated human tissues, safety precautions, and the uses for human tissues have been greatly modified over the last few years. The authors describe the various obligations implicated by these activities and the consequences for tissue banks and surgeons; They describe different processes for bone inactivation and their action on allograft mechanical properties, or the biological capability for integration to the host bone. The authors then discuss different current techniques for bone stock reconstruction and the results in prosthetic or tumoral surgery, as well as their consequences on current surgical indications. In conclusion, they emphasize the optimal conditions for the success of allografts in orthopedic use: stability of the host bone-graft junction, vitality of the bone support, and a favourable mode of constraint of the graft, which have to be protected by osteosynthesis, but should not, however, miss partial bearing.

Human herpesvirus-6 and human herpesvirus-7 in the bone marrow from healthy subjects.

BACKGROUND: Human herpesviruses (HHVs) 6 and 7 are recently discovered betaherpesviruses. Although HHV-6 has been associated with disordered hematopoiesis in bone marrow transplant recipients, little information is available on the presence of both viruses in the bone marrow from healthy subjects. METHODS: We detected HHV-6 and HHV-7 DNA by means of polymerase chain reaction in bone marrow and peripheral blood samples from 18 healthy subjects who underwent total hip arthroplasty. RESULTS: Genomic HHV-6 and HHV-7 DNA were detected in 11% and 67% of the blood samples, respectively, and in 28% and 50% of the bone marrow samples, respectively. CONCLUSIONS: Both viruses may be present in the bone marrow without hematopoiesis disorder and can be transmitted through bone marrow infusion. Therefore, the causative role of these two viruses in some bone marrow diseases cannot be inferred simply from the detection of their genome in bone marrow by means of polymerase chain reaction.

[Proximal femoral reconstruction with megaprosthesis versus allograft prosthesis composite. A comparative study of functional results, complications and longevity in 41 cases]. / Prothèse massive et prothèse manchonnée d'une allogreffe pour la reconstruction de l'extrémité supérieure du fémur.

PURPOSE OF THE STUDY: To compare femoral reconstruction using megaprosthesis versus allograft prosthesis composite. MATERIAL AND METHODS: Forty-one consecutive proximal femoral reconstructions with an allograft-prosthesis composite (21 cases) or a megaprosthesis (20 cases) after tumor resection were reviewed in a retrospective study. The following criteria were considered: functional outcome; long term survival; complications. Chi-square test and Wilcox tests were used to compare groups. The medium and long-term survival curves for these reconstructions were made using the Kaplan-Meier standard methods. The failure of prosthesis was defined as revision for mechanical failure (either aseptic loosening or dislocation), for infection or local recurrence. The comparison of the curves was performed using the Log-Rank test. RESULTS: Infection (10 p. 100) and instability, in both groups, and loosening, in the megaprosthesis group, were the common causes of failure. There was difference between functional results in the two groups (limping and crutches using was more lower in allograft-prosthesis composite group). Survival analysis showed a 5 and 10-year survival of 77 +/- 12 p. 100 for the patients with composites. Five and ten - year survival were 73 +/- 11 p. 100 and 0 p 100 respectevely for those with megaprostheses. No significant difference was noted between survival of these two groups but a tendancy (p =0.09). Radiological allograft resorption was noted for more than 50 p. 100 of allograft composite prosthesis without modification of functional result or symptomatic loosening. DISCUSSION: The functional results seem better in the composite group when compared to the megaprosthesis group. Reconstruction of the abductor mechanism is essential to stabilize the prosthesis and to decrease the limp. When the great trochanter cannot be preserved, we used suture of gluteus medius tendon to tensor of fascia lata, which is re-enforced using a piece of biceps femoris. The dislocation rate was approximately the same in our two groups. Several authors reported a lower dislocation rate with composite reconstructions than massive prosthesis. The rate of infection is similar to other reported series. In our study it has been possible to show a tendancy for superior survival of the composite reconstruction. When the review was later than 5 years the radiological appearance of the graft in our series was often concerning with resorption or fragmentation present in six of the eight cases. This radiological appearance is not as yet responsible for any revision or any change in the functional result however it does remain a worry. CONCLUSION: Composite reconstructions probably allow a better functional result when considering proximal reconstruction of the femur. The radiological appearance of these allografts in the long term is however worry some without any evidence so far of worsening functional level or any evidence of prosthetic loosening. It would seem to us that the current level of knowledge would advocate the use of massive allografts together with prosthesis. This does seem still to remain the best choice for proximal femoral reconstruction.

[Quality plan of a bone tissue bank]. / Plan qualité d'une banque de tissus osseux.

In 1994, the French bioethics laws changed the regulations concerning donated human tissues with safety precautions and therapeutic use. The decree of 29(th) December 1998 describes the practical obligations required of bone tissue banks for approval by the French Health Ministry. Before the new regulations, a quality system was implemented at the Cochin hospital bone tissue bank. It integrates quality control for each step of the general process. We describe the quality plan of the Cochin Hospital bone tissue bank and show that the specific quality practices, resources and sequence of activities improve distribution of human bone allografts while maintaining their traceability.

[Femoral reconstruction with massive allograft implanted in a split femur. Mid-term results of 18 reconstructions]. / Reconstruction fémorale par une allogreffe massive implantée dans un fémur ouvert. Résultats à moyen terme de 18 reconstructions.

PURPOSE OF THE STUDY: Extensive loss of femoral bone subsequent to implant loosening raises an unsolved problem. The purpose of this work was to examine mid-term results of 18 iterative total hip arthroplasties with femoral reconstruction using massive allografts performed between 1986 and 1997. MATERIALS AND METHODS: Using the Vives classification, the femoral bone lesions were grade 3 (n =2) and grade 4 (n =16). The reconstruction was achieved with radiated massive allografts measuring 11 to 35 cm implanted in a split host femur. Charnley-Kerboull implants with a long stem were cemented in the reconstructed femurs. RESULTS: Mean follow-up was 4 years 10 months (range 2 to 9 years). Nine complications in 7 hips were observed: 6 trochanter nonunions, two recurrent prosthesis dislocations and 1 femoral fracture. At last follow-up, the functional result was excellent or very good in 12 hips (Merle d'Aubigné classification). A stable fixation persisted for 15 implants and 3 had loosened. Graft-host femur consolidation was achieved in all cases except 1. There were 3 cases with extensive resorption of the graft including 2 associated with loosening of the femoral component. DISCUSSION: Reconstruction of the femur after extensive bone loss using a massive allograft appears to be a useful method for restoring bone tissue and providing immediate mechanical support for the femur.

[Knee replacement arthroplasty in hemophilia: results, complications and predictive elements of their occurrence]. / Arthroplastie totale du genou chez l'hémophile. Résultats, complications et éléments prédictifs de leur survenue.

PURPOSE OF THE STUDY: Determine the effect of supplementation rate and HIV disease on results and complications in total knee replacement in hemophilia. MATERIAL: Twenty-nine total knee arthroplasties were performed in twenty-one disabled patients with major hemophilia, from 1986 to 1995. All the implants were postero-stabilised prostheses. The average age of patients at the time of surgery was 40.8 years, average follow-up was 4.8 years. Preoperatively, all patients complained of severe pain, with stage IV or V arthropathies, according to Arnold classification. Twelve patients were HIV sero-positive. METHOD: Functional and radiological results, and postoperative complication rate was analyzed in relation with mean deficient factor titer, HIV status, and periarticular soft tissues quality. RESULTS: Results of the total knee arthroplasties, as determined by the IKS scoring system, were 86.2/100 for Pain, Motion, Stability and 88.7/100 for function. The average gain of motion was twenty-four degrees. One patient required amputation, and one an arthrodesis after deep infection. Postoperative complications, in addition to infections, included intra articular bleeding in nine patients, one peroneal nerve palsy, two instances of inhibition to factor VIII, four superficial skin necrosis, and one important gastric bleeding which required surgical treatment. A high titer of deficient factor (> 70 per cent of the average normal concentration) seemed correlated with a lower complication rate. In this study, surgery had no incidence on HIV disease evolution. DISCUSSION: Authors emphasize the high level of postoperative infections (6/29), particularly in patients with HIV infection (5/12) frequently after superficial skin necrosis, as well as the high postoperative complication rate. CONCLUSION: However good results were finally observed, association of HIV disease, insufficient deficient factor concentration, and altered quality of periarticular soft tissues increased particularly complication occurrence. With particular attention to these factors, and despite frequent complications, total knee arthroplasty in hemophilia restores good function and allows patients satisfaction.

Prevention of heterotopic ossification in hip arthroplasty. The influence of the duration of treatment.

A retrospective study has been carried out to assess the effectiveness of indomethacin in preventing heterotopic ossification after total hip arthroplasty, and the effect of using it for different periods of time. One hundred and sixty-eight hips operated on in 1983 were not given indomethacin and acted as a control. One hundred and fifty hips operated on in 1988 were given indomethacin and divided into 3 groups: 42 received indomethacin for 5 days, 49 for 11 days and 59 for 45 days. The results indicate that ossification is significantly reduced in those patients receiving indomethacin for 5 and 11 days, but there was no additional reduction when it was given for 45 days. Treatment should begin on the night of operation and continued for 11 days while the patient remains in hospital.

[Functioning of a bone tissue bank in 1998]. / Fonctionnement d'une banque de tissus osseux en 1998.

Last few years, the french legislation and reglementation concerning donated human tissues, safety precautions, and human tissues' uses have been deeply modified. Therefore, tissue banks' organisation, processing of allograft tissue, and the way surgeons use frozen bone graft have changed. Accordingly, authors describe different obligations these activities implicate and practical consequences for tissue banks and surgeons. First, they recall 94' laws and the doctrinal and ethical principles essential to understand current laws and official standards. Then, they specify sanitary rules all tissue banks have to conform to. They detail the different approaches to recovery, processing, preservation and distribution of transplantable bone tissue and expose modalities of the financing by social organisms. It follows practical consequences in bank functioning: supplying, importation, internal organization. In conclusion, authors synthesize surgeon's responsibilities in that specific activity.

Heterotopic ossification after total hip arthroplasty: risk factors and prevention.

A retrospective review of 168 consecutive total hip arthroplasty procedures done in 1983 at the Cochin Teaching Hospital, Paris, France, was conducted to determine the rate of occurrence of heterotopic paraarticular ossification and to look for risk factors for this complication. None of the patients received preventive therapy for heterotopic ossification. Mean age was 66.2 years. The reason for arthroplasty was hip osteoarthritis in every case. The index operation was the first arthroplasty procedure. Heterotopic ossification was noted in 61.3% of patients and was high-grade in 8.3%. The rate of occurrence of heterotopic ossification was not influenced by age, gender, joint destruction, preoperative osteophytosis, duration of the arthroplasty or the occurrence of complications during or after the arthroplasty. However, severe ossification was more common in men that in women (12.7% men versus 5.7% women had grade III ossification) and in patients operated on by relatively inexperienced surgeons (28/8% grade II and III ossifications, versus 14.7% in patients operated on by experienced surgeons). The rate of occurrence of heterotopic ossification in the patients who had no risk factors (60.9%) was not significantly different from that in the overall study population. These data suggest that preventive strategies targeted to specific patient subgroups would probably be ineffective, and that routine preventive therapy of all total hip arthroplasty patients is warranted.