We have done emergency vascularized composite graft by microsurgical technique for severe open fractures. It is essential for open injury to cover bones, joints, tendons etc. Vascularized composite graft for open fracture with tissue defect covers bone etc., prevents infection and promotes subsequent early functional recovery. Eighteen patients aged 3–55year old with an average age of 23.1y.o. were treated with this methos. Traffic injuries of leg and foot in children were the most common and others were open severe fracture with tissue defects. The composite graft employed were peroneal osteocutaneous flap, latissimus dolsi flap, parascapular flap and groin flap. The advantage of these flaps to cover the damaged structure primrily facilitatrs rapid tissue repair without infection and scar formation. In fact, except one reoperation due to a skin necrosis in parascapular flap, all grafted flaps successfully repaired the severe damaged bone and joint. Sufficient perfusion of antibiotics by these vascularized flap prevents infection in all cases. Primary emergency vascularized composite graft for severe open fracture with tissue defect is shown to be extremely useful method with rapid repair and functionnal recovery.

Infected non-union after severe open fracture or unsuitable fracture operation is frequently associated with bone defect and its treatment has been controversial. We have used microsurgical vascularised composite graft for these problematic cases. Fifty one patients aged 17∼70 year old (43.6 years old in average), including 41 men and 10 women. Follow-up has been more than 6 months. The vascularised composite graft included a free fibular osteocutaneous flap in 41 cases, a vascular pedicled fibular osteocutaneous flap in 2 cases, a free iliac osteocutaneous flap in 5 cases, a vascularised cutaneous flap in 2 cases and other in one case. All infected non-unions were united without trouble and co-existing infection was successfully eradicated. This method also enables the patients rapid bone union and subsequent early functional recovery. This success was attributed to greater transport of oxygen and good antibiotic perfusion in presence of good blood supply. We conclude that microsurgical vascularised composite graft for infected non-union is an extremely useful method with early bone union and subsidence of infection.

Introduction: To improve the therapeutic results for AO type C intraarticular distal radius fractures in young and middle-aged patients, it is important to achieve and maintain anatomical reduction, and evaluate and treat soft-tissue injuries. We previously employed arthroscopically assisted reduction and percutaneous pinning (ARPP) combined with external fixation. Since 2003, we have employed ARPP combined with open reduction and internal fixation (ORIF) using volar locking plates.

Methods: The subjects were twenty-six patients under 60 years old. The patients comprised thirteen men and thirteen women aged from 16 to 57 (mean 43.5) years. The type of fracture according to the AO classification was C1 in six patients, C2 in ten, and C3 in ten. The follow-up period was 12–18 (mean 13.5) months. The radial inclination (RI), volar tilt (VT), and ulnar variance (UV) were measured radiographically at the time of injury, immediately after surgery, and at final evaluation. The Mayo wrist score was used for clinical evaluation.

Results: Union was achieved in all patients. The triangular-fibrocartilage complex injury was detected in nineteen patients, the scapholunate-interosseous ligament injury in twenty-three, and the lunotriquetral-interosseous ligament injury in nineteen. Radiographic evaluation showed that the mean RI, VT, and UV at presentation, immediately after surgery, and at final evaluation was 12.8, 21.0, and 20.9 degrees, −15.4, 9.7, and 9.6 degrees, and 3.10, 0.30, and 0.35 mm, respectively. The Mayo wrist score averaged 87.6 points.

Conclusion: Although treatment of AO type C intraarticular distal radius fractures is difficult, ARPP combined with ORIF achieved relatively good results.

Introduction: Recently, highly cross-linked polyethylene has been highlighted in THAs, which is thought to reduce wear. However, little is known about an accurate nature of cross-linked polyethylene particles and long term wear in vivo. One of the authors implanted all polyethylene cups irradiated by 100 Mrad in 1970’s. Recently, we performed two revisions with this cup. In the present study, we extracted polyethylene particles and analyzed them.

Methods: Case1 was revised for a stem fracture and ace-tabular loosening at 25 years postoperatively and case2 for acetabular loosening at 27 years postoperatively. There was no osteolysis on X rays. We extracted polyethylene particles using a tiussue digestion and iamge analysis using computed iamge analyzer developed by Cambell.

Results: Equivalent circle diameter (ECD) was 0.73mm, roundness was 0.69, aspect ratio (AR) was 1.4 and number of particles was 6.0x108/g wet tissue in case1. ECD was 0.57mm, roundness was 0.62, AR was 1.54 and number of particles was 5.8x108/g in case2. SEM showed that granule or globular shapes were abundant and fibril shapes were rare.

Discussion and conclusion: Cross-linked polyethylene particles were less, a little smaller and much rounder in compared with our previous result of conventional polyethylene particles in peri-implant tissue after more than 25 years postoperatively in vivo.

Impaction allografting is one of the techniques for reconstruction of femur during revision total hip arthroplasties. The initial stability of the stem fixed with impacted morsellized allogtafts and cement depends on multiple factors. The aim of this study was to investigate the stability of stem in reference to the size of bone chips, femoral bone defect and implant design.

Morsellized grafts of human femoral heads were prepared using a reciprocating type bone mill or a rotating type bone mill. Femoral bone defect was created at proximal medial cortex. Two types of polished stem were tested; CPT stem and VerSys CT stem (Zimmer Inc.). The cross section of the stem was relatively rectangular in CPT stem, while round in VerSys CT stem. Morsellized grafts were impacted into an over-reamed plastic bone and the stem was fixed with PMMA bone cement. Cyclic compression test and torsional test were performed using an Instron type machanical tester. Bone chips prepared by a reciprocating type bone mill contained large chips with broad size distribution, which represented high stiffness in compression test and high maximum torque in torsional test. Femoral bone defect and implant geometry did not affect the axial stability of stem, while large bone defect and round shape stem showed significantly lower maximum torque.

These results indicated that the size of bone chips, femoral bone defect and implant geometry affected the initial stability of the stem. Impaction grafting seems to be a technically demanding procedure, however several factors can be controlled to obtain secure implant stability.

As for the number of patients who requires total knee arthroplasty (TKA), Asian-Pacific countries will be the most important market. However, due to the paucity of anthropometric data on the proximal tibia in this population, many prostheses designed for Caucasian knees have been introduced without specific modification.The aim of the current study was to analyze the geometry of the proximal tibia to design the optimum component for the Japanese population.

Anthropometric data on the proximal tibia of 100 knees in 80 patients undergoing TKA was obtained. Briefly, anterior-posterior (AP) and medial-lateral (ML) lengths were measured with a combination of two different methods, namely on the computed tomography (CT) images obtained preoperatively and intraoperative direct measurement on tibial resection surface. Reproducible measurement was possible only when the intraoperative measurement was combined with the corresponding CT images while the direction of measurements being aligned to the epicondylar axis of the femur.

It was shown that smaller components with an ML of around 60 mm were rarely required. Tibial component size variation should focus on an ML length of 65 to 75 mm because 76 of 100 knees (76 %) fell into this size range. When the subjects were confined to women, 70 of 77 knees (91%) were included in this size range. The intraoperative AP to ML ratio had a negative correlation with the ML length (r = −0.412, P < 0.0001) indicating that bigger knees were shallower in the AP direction. The size variation of currently popular pros-theses were not in accordance with the geometry of the tibial resection surface shown in this study.

The results of this study applied to a cross-section of the Japanese population can be used by manufacturers to create a prosthesis suitable for most of the Asian-Pacific population.

Introduction: The excellent character of cross-linked polyethylene on wear has been reported from basic researches. However, few clinical results were seen about irradiated polyethylene sockets. This presentation reports a long-term clinical result of irradiated polyethylene sockets.

Material and method: Two 100M-rad gamma irradiated polyethylene sockets were retrieved, each 25 and 27 years after implantation. Socket joint surface were scanned by 3-D scanner and analyzed. On the other hand, ten patients had total hip replacements with 6.5M-rad irradiated polyethylene sockets. Anterior-posterior and lateral radiograph were taken and the movement of the head to the socket was analyzed by 3-D wear measurement software GAWDI. The results were compared to conventional polyethylene sockets of matched patients.

Results: Wear of the 100M-rad sockets were 0.23mm/ 25yrs and 0.46mm/27yrs respectively. The direction of wear was observed over the whole surface. Wear of the conventional polyethylene socket retrieved 15yrs after implantation were 2.54mm/15yes and 1.76mm/12yrs. The wear were toward weight bearing directions.

The average movement of heads in 6.5M-rad irradiated polyethylene sockets was 0.22mm one year post operation and its direction was toward backside of patients’ body. The average movement of conventional polyethylene sockets was 0.24mm one year post operation and its direction was just the same as irradiated polyethylene sockets.

Discussion: The difference of long term results between 100M-rad irradiated polyethylene and conventional one was obvious. A definite wear path way was observed on conventional polyethylene sockets. However, it was ambiguous on 100M-rad irradiated polyethylene because it was small or it did not exist. No remarkable difference was observed in short term after operation between 6.5M-rad irradiated and conventional sockets. The present analysis suggests that a high dose irradiated polyethylene socket may benefit a good long-term clinical result.

The role of posterior cruciate ligament (PCL) in total knee replacement (TKR) has been a matter of debate for long time and remains controversial. In this study, the effect of posterior cruciate ligament (PCL) sacrifice on the tibiofemoral joint gap was analysed in 30 varus osteoarthritic knees undergoing posterior stabilized total knee replacement. Medial soft tissue was released and bone cut was made without preserving the bone segment of tibial PCL insertion. Then the medial and lateral joint gaps in full extension and 90□& lsaquo; flexion were measured before and after PCL sacrifice using a tensioning device (V-STAT tensor(tm), Zimmer). After PCL sacrifice, the flexion gap significantly increased both in medial and lateral side (4.8 □} 0.4 and 4.5 □} 0.4 mm respectively, mean □} SE) compared to those seen in the extension gap (0.9 □} 0.2 and 0.8 □} 0.2 mm, p < 0.001 ANOVA). There was no significant difference between the changes in the medial and lateral gap (p = 0.493). In conclusion, results of this intraoperative measurement showed that PCL sacrifice leads to a selective increase in the size of flexion gap by an average of 4.7 mm whereas it had little impact on the correction of varus deformity. These findings provided insights as for the role and necessity of PCL sacrifice in the correction of varus and flexion deformity. Because the flexion gap surpassed the unchanged extension gap during PCL sacrifice, PCL release could be used as a surgical technique to balance the gaps without additional bone cut.

Posterior approach to the lumbar spine necessarily induces structural damage of paravertebral muscles. In order to avoid these changes, we have started to utilize a microscopic decompression of the spinal canal via an unilateral approach since 1998. The purpose of this study was to evaluate the results of this operative procedure for lumbar spinal canal stenosis.

A total of 18 patients, 13 men and five women, were reviewed. The age at the time of surgery ranged from 53years to 78years with a mean of 69.0years. Follow up period averaged 12.3months ranging from one to 32months. As for operative procedure, unilateral paravertebral muscle was retracted laterally and lam-inotomy in the approached side was performed. Following complete decompression of a nerve root in the approached side, microscope was tilted and the inner aspect of lamina in the contralateral side was resected using high-speed drill with a guard of yellow ligament to dural sac and nerve root. Following the procedure, yellow ligament was resected and nerve root in the contralateral side was decompressed.

Results: In operation time, blood loss and recovery rate of JOA score, there were no statistical differences compared with ordinal laminotomy cases. Dural sac was well decompressed not only in the hemilaminec-tomy side but also in the contralateral side. All cases showed intensity change of paravertebral muscle in the approached side on T2 weighted MRI.

Conclusion: The procedure described here was definitely effective because paravertebral muscle in the contralateral side and midline structure of the lumbar spine could be completely preserved.

The fingertips are important for not only the function of the hand but also cosmetic reasons. In distal phalanx, arteries especially in zone …Ÿ are less than 0.5 mm in diameter however they can be anastomosed ultramicro-surgically with 11-0 suture.

From 1976 to 1999, I have replanted 463 digits in 337 male and 126 female patients whose ages ranged from 4 months to 80 years, with an average of 32.7 years. There were 312 digits with complete amputation, 151 digits of incomplete amputation, 277 digits with trauma in zone …Ÿ and 186 digits in zone … in which more than six months had passed since the replantation.

The results in zone … amputations was better then in cases of amputations in zone …Ÿ because anastomoses of arteries and viens are more relibale in zone … amputation.

I analyzed the results of zone …Ÿ amputation according to types of injury. The survival rate was 100% in clean-cut amputation, 91.7% in blunt-cut, 66.1% in crush and 67.5% in avulsion. So in cases of crush or avulsion amputation in zone …Ÿ, there is relative indication for replantation.

As for postoperative functional recovery, 95% of the survival fingers are in good daily use, or in some use. Compared with stump plasty, our results of survival fingers are far superior functionally and cosmetically. From a survival rate and functinal point of view, replnatation is definitely indicated in cases of zone …Ÿ amputations by clean-cut or blunt-cut and zone … amputations if technically possible.

The purpose of this study was to investigate the bone anatomy in determining the rotational alignment in total knee arthroplasty (TKA) using CT scan. Axial CT images of eighty-four varus osteoarthritic knees undergoing TKA were analysed. On the images of the distal femur and the proximal tibia, base line for anterior-posterior axis of each component was drawn based on the epicondylar axis for the femur and medial one-third of the tibial tuberosity for the tibia. Angle between these two lines was analysed as the rotational mismatch between the components when they were determined based on the anatomical landmark of each bone. Thirty-eight knees (45%) showed more than 5-degree mismatch and seven knees (8.3%) showed the mismatch more than 10-degree. There was a tendency to put the tibial component in external rotation relative to the femoral component when they were aligned to medial one-third of the tibial tuberosity. The results have indicated that the landmark of each bone was the intrinsic cause of the rotational mismatch between the components. The surgeons performing TKA surgery should aware of this fact and should align the tibial component in a compromised position, if necessary, to have overall satisfactory clinical outcome.

Open reduction for developmental dislocation of the hip (DDH) is invasive and sometimes results in femoral head deformity while open reduction has been the first choice in case non-operative reduction is failed in.

We treated 3 patients with 3 affected hips using minimum invasive arthroscopic reduction method. Pre-operative MRIs represented these 3 hips had obstruction of interposed thick limbus. The average age of patients treated by this method was 23 months.

This method consists of arthrogram, arthroscopic limboplasty, and arthroscopic reduction. This series of maneuvers was able to lead unreducable hips to the reduction position.

Post-operative MRIs represented that the interposed thick limbus had been removed to the outside of acetabulum and the limbus covered the reduced femoral head. There were no signs of residual subluxation of the hips in radiographic examination.

This new minimum invasive arthroscopic reduction method have a possibility to take the place of the invasive open reduction in the treatment of DDHs with obstruction of interposed thick limbus.

We studied active flexion from 90° to 133° and passive flexion to 162° using MRI in 20 unloaded knees in Japanese subjects. Flexion over this arc is accompanied by backward movement of the medial femoral condyle of 4.0 mm and by backward movement laterally of 15 mm, i.e., by internal rotation of the tibia. At 162° the lateral femoral condyle lies posterior to the tibia.

We investigated the effects of low-intensity pulsed ultrasound on distraction osteogenesis in a rabbit model.

Callotasis of the right tibia was performed in 70 male Japanese white rabbits using mini-external fixators. In the first part of the study in 64 animals using normal distraction (waiting period seven days; distraction rate 0.5 mm/12 hours; distraction period ten days), we evaluated the distraction site by radiography, measurement of the bone mineral density (BMD), mechanical testing, and histology. In the second part in six rabbits using fast distraction (waiting period 0 days; distraction rate 1.5 mm/12 hours; distraction period seven days) the site was evaluated radiologically. Half of the animals (35) had received ultrasound to their right leg (30mW/cm²) for 20 minutes daily after ceasing distraction (ultrasound group), while rigid fixation only was maintained in the other half (control group). With normal distraction, the hard callus area, as shown by radiography, the BMD, and the findings on mechanical testing, were significantly greater in those receiving ultrasound than in the control group. Histological analysis showed no tissue damage attributable to exposure to ultrasound. With fast distraction, immature bone regeneration was observed radiologically in the control group, while bone maturation was achieved in the ultrasound group.

We conclude that ultrasound can accelerate bone maturation in distraction osteogenesis in rabbits, even in states of poor callotasis.

We have reviewed 103 of 126 Chiari osteotomies carried out in our department between 1956 and 1987. The cases were graded radiologically, using the Japanese Orthopaedic Association (JOA) system, into a pre/early osteoarthritis (OA) group and an advanced OA group. In the pre/early group there were 86 hips. The mean follow-up was for 17.1 years (4 to 37). Preoperatively, 51 hips had an average JOA clinical score of 78.6 ± 8.4 points and the final mean JOA clinical score was 89.4 ± 12.5 points. Advanced degenerative change developed in 33.7% and one hip required a total replacement arthroplasty (TRA). Chiari osteotomy alone, without accompanying intertrochanteric osteotomy, was performed on 62 hips. For these the median survival time was 26.0 ± 2.5 years, using as the endpoint progression to advanced OA. Differences in survivorship curves related significantly to the severity of the preoperative OA, the shape of the femoral head and the level of osteotomy. In the advanced OA group, we followed up 17 hips for a mean of 16.2 years (1 to 27). Before operation, the mean JOA clinical score in 13 hips was 63.2 ± 7.9 points and the final score 84.0 ± 12.0 points. TRA was eventually carried out on four hips.

Our findings suggest that the Chiari osteotomy remains radiologically effective for about 25 years. The procedure is best suited to subluxated hips with round or flat femoral heads and early or no degenerative change. Intra-articular osteotomy can lead to osteonecrosis, and should be avoided. In hips with advanced OA, the Chiari procedure creates an acetabulum which facilitates later TRA, and may delay the need for this procedure in younger patients.

Accurate quantitative measurements of micromovement immediately after operation would be a reliable indicator of the stability of an individual component. We have therefore developed a system for measuring micromovement of the tibial component using three non-contact displacement transducers attached to the tibial cortex during total knee arthroplasty (TKA). Using this system we measured the initial stability in 31 uncemented TKAs. All the tibial components were fixed by a stem and four screws. The initial stability was defined as the amount of displacement when a load of 20 kg was applied. The mean subsidence was 60.7 μm and the mean lift-off was 103.3 μm.

We also studied the migration of the tibial component using roentgen stereophotogrammetric analysis (RSA) for up to two years after operation. Most migration occurred during the first six months, after which all prostheses remained stable. We defined migration as the maximum total point motion (MTPM) at two years after operation. The mean migration was 1.29 mm at two years.

Our results show that there was a significant correlation between the initial stability and migration (p < 0.05) and emphasise the importance of the initial stability of the tibial component.

The design and use of a prong plate for the treatment of displaced fractures of the femoral neck is described. The prongs hold the femoral head, and the plate is screwed to the anterior cortex of the femoral neck and trochanteric region. The new plate has been used in 32 patients with Garden stage III or IV fractures and 29 had a good result. Bony union was seen within 11 weeks in all patients in whom bleeding of the femoral head was noted at operation, but was much delayed in patients without bleeding. Late segmental aseptic necrosis was seen in four patients after follow-up of at least two years, and successfully treated. The prong plate allows accurate reduction, impaction and strong rigid fixation with less disturbance of the intramedullary blood flow than other fixation methods.