Improved cement technique by interposing less than two layers of hydroxyapatite (HA) granules between bone and bone cement at the cementing (Interface Bio-active Bone Cement : IBBC) have been performed in total knee arthroplasty (TKA) since 1987.

We performed IBBC technique in 153 knees (130 patients) in TKA from 1987 to 1993. One hundred and forty knees (120 patients) could be followed up clinically and radiologically. Follow up rate was 91.5%. A mean follow-up period was 9.5 years (6 to 13 years) after surgery. As a control, clinical results of TKA with conventional cementing (Non-IBBC) which were operated in 44 knees (44 patients) in 1986 were used.

In IBBC cases, radiolucent lines on the tibial components were seen 7.1%, 2.9%, 1.4%, 3.6%, 0%, 0% and 0% at Zone ‡T to ‡Z of the anteroposterior view, while in Non-IBBC cases, 40.9%, 13.6%, 9.1%, 27.3%, 11.4%, 4.5% and 13.6% at Zone ‡T to ‡Z, respectively. In IBBC cases peri-prosthetic osteolysis of the tibial components were seen in three knees (2.1%), while 29.5% in Non-IBBC cases. Aseptic loosening of the tibial component was only one case (0.7%) in IBBC cases, while 9.1% in Non-IBBC cases.

In IBBC, bone cement bound to HA mechanically immediately after surgery and HA granules bound to the bone physicochemically after bone ingrowth into the spaces around the HA granules. In Non-IBBC, spaces will appear between bone and bone cement due to osteoporosis and/or atrophy after long years. However, in IBBC, bone and bone cement will contact by interposing HA forever due to osteoconductive effect of HA.

In conclusion, the IBBC has significantly reduced the incidence of radiolucent lines and periprosthetic osteolysis in TKAs. IBBC is a method combining the advantage of cementless HA coating and bone cement.

We have used Interface Bioactive Bone Cement (IBBC) in all cases of total joint arthroplasties since 1987. The method is improved cement technique by interposing less than two layers of hydroxyapatite (HA) granules between bone and the polymethylmethacrylate (PMMA) bone cement. We report one patient who underwent revision surgery after total knee arthroplasty (TKA) using IBBC.

The patient is a woman aged 70 years at the time of revision surgery. Right TKA was performed with the diagnosis of rheumatoid arthritis. An alumina ceramic total knee prosthesis was inserted using IBBC. Pain and walking ability were once improved after the primary TKA. However, the gait disturbance recurred after the patient fell on the ground. Radiographic findings showed severe genu varum, but neither radiolucent lines around the components nor migration of the components were seen. This was revised with semiconstrained prosthesis for the purpose of improving lateral instability at 31 months after the primary TKA.

Avulsion of fibular attachment of collateral ligament was seen at the time of the revision surgery. As PMMA cement was strongly adhered to the bone, it was removed together with cancellous bone. Histologically, HA granules bound to the bone directly after bone ingrowth into the spaces around the HA granules. This is the reason we have described IBBC as a method having the both advantages of cementless HA coating and PMMA bone cement.

After the revision surgery, the walking ability was improved.

In conclusion, this case showed excellent characteristics of IBBC.

In cases above C4 cervical cord injury a respiratory distress and serious pulmonary complications occur with frequent obstruction of air way by increased excretion and difficult evacuation. Long term tracheal intubation often provides many general complications. We analized advantage and demerit of early tracheotomy in such cases of cervical cord injury patients.

Material and Methods: 1) We proposed early tracheotomy to prevent complications and ease respiration when pts showed low vital capacity (v.c.) less than 500cc showing deltoid/biceps palsy and respiratory distress with much excretion and difficult evacuation. 2) We have analysed 91 patients who needed ventilator out of 845 cervical cord injury patients who admitted in our hospital. 2) 25 pts were treated by tracheotomy from the beginning of treatment, and others were switched over from management of tracheal intubation. 3) We used a double cuff tracheotomy tube to prevent continuous pressure to the tracheal wall. 4) Weaning from ventilator was done when Fi02< 0.3, PEEP< 5cmH2O and PaO2> 80mmHg in room air.

Results: 1) 4 (16%) out of 25 pts who had been treated with tracheotomy from the beginning had atelectasis, whereas 15 (23%) out of 66 pts treated with intubation occurred that symtome, and 20% of the pts suffered pneumonia. 2) Out of 46 pts treated with intratracheal intubation in the beginning and then changed to tracheotomy within 4 days 7(15%) had atelectasis, whereas 20 (29%) of the pts who underwent tracheotomy after 5 days occurred the complication. 3) As complication of tracheotomy? Infection and? tracheal stenosis were observed but all uneventful healed.

Discussion/Conclusion: 1) Acutecervical cord injury pts showing deltoid/biceps palsy have impending respiratory distress. Examination of spirometer is essential. In such cases low v.c. < 500 tracheotomy should be indicated. 2) Continuing respiratory distress > 4days of intubation it is advised tracheotomy in order to prevent genera l complications. 3) Combination with frequent position changing and chest tapping is also essential for evacuation.