Background and Purpose

Soft-tissue balancing is crucial in total knee arthroplasty, but proper release of medial collateral ligament is a challenging procedure. It has been well recognized that medial gap tends to be more tight than lateral gap in varus knees after surgery. The purpose of this study is to investigate the incidence and predictable factors of medial tibial bone remodeling following navigation-assisted total knee arthroplasty.

The purpose of this study was to measure the radiological parameters of femoral component alignment of the Oxford Phase 3 unicompartmental knee replacement (UKR), and evaluate their effect on clinical outcome. Multiple regression analysis was used to examine the relative contributions of the radiological assessment of femoral component alignment in 189 consecutive UKRs performed by a single surgeon. The American Knee Society scores were compared between groups, defined as being within or outside recommended tolerances of the position of the femoral component. For the flexion/extension position 21 UKRs (11.1%) lay outside the recommended limits, and for posterior overhang of the femoral component nine (4.8%) lay outside the range. The pre-operative hip/knee/ankle (HKA) angle, narrowest canal distance from the distal femoral entry point of the alignment jig and coronal entry-point position had significant effects on the flexion/extension position. Pre-operative HKA angle had a significant influence on posterior overhang of the femoral component. However, there was no significant difference in American Knee Society scores relative to the position of the femoral component.

Introduction

Many literatures regarding more specific tests to diagnose the supraspinatus tendon injuries and the best rehabilitation methods to strengthen the supraspinatus have been published. However, conflicting results have been reported. 2-deoxy-2-[18F] fluoro-D-glucose (FDG) positron emission tomography (PET) has been recently used to assess skeletal muscle activities in various fields.

Medium-term survivorship of the Oxford phase 3 unicompartmental knee replacement (UKR) has not yet been established in an Asian population. We prospectively evaluated the outcome of 400 phase 3 Oxford UKRs in 320 Korean patients with a mean age at the time of operation of 69 years (48 to 82). The mean follow-up was 5.2 years (1 to 10). Clinical and radiological assessment was carried out pre- and post-operatively. At five years, the mean Knee Society knee and functional scores had increased significantly from 56.2 (30 to 91) pre-operatively to 87.2 (59 to 98) (p = 0.034) and from 59.2 (30 to 93) to 88.3 (50 to 100) (p = 0.021), respectively. The Oxford knee score increased from a mean of 25.8 (12 to 39) pre-operatively to 39.8 (25 to 58) at five years (p = 0.038). The ten-year survival rate was 94% (95% confidence interval 90.1 to 98.0). A total of 14 UKRs (3.5%) required revision. The most common reason for revision was dislocation of the bearing in 12 (3%). Conversion to a total knee replacement was required in two patients who developed osteoarthritis of the lateral compartment.

This is the largest published series of UKR in Korean patients. It shows that the mid-term results after a minimally invasive Oxford phase 3 UKR can yield satisfactory clinical and functional results in this group of patients.

Lengthening of the humerus is now an established technique. We compared the complications of humeral lengthening with those of femoral lengthening and investigated whether or not the callus formation in the humerus proceeds at a higher rate than that in the femur. A total of 24 humeral and 24 femoral lengthenings were performed on 12 patients with achondroplasia. We measured the pixel value ratio (PVR) of the lengthened area on radiographs and each radiograph was analysed for the shape, type and density of the callus. The quality of life (QOL) of the patients after humeral lengthening was compared with that prior to surgery. The complication rate per segment of humerus and femur was 0.87% and 1.37%, respectively. In the humerus the PVR was significantly higher than that of the femur. Lower limbs were associated with an increased incidence of concave, lateral and central callus shapes. Humeral lengthening had a lower complication rate than lower-limb lengthening, and QOL increased significantly after humeral lengthening. Callus formation in the humerus during the distraction period proceeded at a significantly higher rate than that in the femur.

These findings indicate that humeral lengthening has an important role in the management of patients with achondroplasia.

In total hip arthroplasty (THA), one of concerned issues is osteolysis due to wear debris of ultra-high molecular weight polyethylene (PE) which often leads to aseptic loosening. Reduction of PE wear debris is essential to prevent osteolysis, and different bearing combination as well as improvement of the bearing material itself have been attempted. Hence alumina ceramics was introduced for THA, aiming to reduce PE wear debris. Ceramic on PE couple showed good results in clinical wear compared with metal on PE couples. Highly cross-linked PE (HXLPE) with gamma-ray or electron-beam irradiation followed by thermal treatment has also demonstrated a remarkably low wear in the previous in vitro studies. In in vivo studies, the wear of HXLPE acetabular cups against alumina ceramic femoral head was evaluated to compare with that of conventional PE cups against alumina ceramic femoral head.

The in vivo wear of 61 HXLPE cups (Aeonian; Kyocera Corp., Kyoto, Japan, currently Japan Medical Materials Corp., Osaka, Japan) against alumina ceramic femoral head of 28 mm in diameter with clinical use for 2.1–7.1 years (mean 5.6 years) and eight conventional PE cups against an alumina ceramic femoral head of 28 mm in diameter used for 18.7–23.3 years (mean 20.4 years) were examined by radiographic analysis with Vector Works 10.5. The in vivo wear of eight retrieved HXLPE cups with clinical use for 0.9–6.7 years (mean 2.9 years) and 14 retrieved conventional PE cups used for 16.0–28.0 years (mean 22.0 years) were examined by using a three-dimensional coordinate measuring machine. The worn surfaces of retrieved HXLPE and conventional PE cups were observed by a scanning electron microscope.

In the radiographic study, penetration rate of alumina head into HXLPE and conventional PE for the first 1 year were 0.24 mm/year and 0.34 mm/year respectively. One year later, the HXLPE showed significant lower penetration rate of 0.001 mm/year than the conventional PE penetration rate of 0.12 mm/year (p< 0.01). By the retrieval analysis, the mean penetration of retrieved HXLPE and conventional PE cups were 0.11 and 2.97 mm, and they were similar to the results by radiographic analysis. In the worn surface of the retrieved HXLPE cups used for around 1 year, machine marks were observed. In contrast, the worn surface of the retrieved HXLPE cups used for more than five years were smooth, and furthermore, in high magnification observation they had wear morphology different from conventional PE. These findings from this retrieval study suggest the penetration in the first 1 year detected by radiographic measurement was probably caused by creep deformation in bedding-in stage; and 1 year after, the penetration was probably caused mainly by wear.

By the radiographic analysis, HXLPE cups against alumina ceramic femoral head has a 99 % lower wear rate compared with conventional PE cups. Also, retrieved HXLPE cups against alumina ceramic femoral head exhibited lower wear compared with conventional PE cups. In conclusion, we expect that the HXLPE cup used with alumina ceramic femoral head has favorable wear properties in long-term clinical use.

A consensus on total hip arthroplasty (THA) concluded that the major remaining issues of concern included the long-term fixation of the joint replacement, osteolysis due to poluethylene (PE) wear debris which often leads to aseptic loosening. Alumina ceramics had been extensively used in medicine, and we started using the alumina ceramic for THA bearing surface in hopes to reduce the PE debris. It was because alumina ceramics is advantageous for precision machining compared with metal materials, and its hardness is higher than that of metal materials. Also, to augment cement–bone bonding, we interposed hydroxyl apatite (HA) granules at the cement–bone interface, so called “Interface Bioactive Bone Cement (IBBC) technique”. HA granules (2–3 g) were smeared on the bone surface of the acetabulum and femur just before cementing. In this study, we evaluated 19–22 years clinical results of THA with alumina ceramic head combined with PE cup fixated IBBC technique.

Total 285 joints (212 patients) were implanted by one senior surgeon from January 1986 to December 1988, and 265 joints (192 patients) were traceable. Alumina ceramic femoral head of 28 mm in diameter and acetabular cup of the conventional PE sterilized with ethylene oxide gas were used in all patients. The PE cup and stem were fixed with IBBC technique in all cases. The presence of radiolucent line, loosening and osteolysis were observed using radiograph of the traceable cases. The locations of radiolucent lines were identified according to the zones described by DeLee and Charnley for acetabular cups and the zones described by Gruen et al. for femoral stems. The in vivo wear of 21 PE acetabular cups for 19.0–21.9 years (mean 20.3 years) was measured from the latest radiographs using computer assistant technique with Vector Works 10.5 software.

Features of the clinical radiograph images of the IBBC case were classified as follows: the radiolucent line represented “gap” between the HA layer and the cement; the loosening represented “opening” between the HA layer and the cement. For the quantitative analysis, we divided the surrounding bones of the THA into several zones as done in the previous studies. The “gap” appeared in zone 4 in three joints (1.4 %), in zone 3 in two joints (0.9 %) of acetabular cup. In femoral side, in zone 1 in four joints (1.8 %) in zone 7 in one joint (0.4 %). The “opening” appeared in three acetabular cup (1.4 %). Since no opening was appeared in zone 3 or zone 4, however, no re-operation was needed. Images of osteolysis were seen one in zone 1 (0.5 %), and one in zone 2 (0.5 %) in acetabular side and two in zone 1 (0.9 %) of the femur. The mean linear wear rate of PE acetabular cups was 0.13 mm/year.

The fixation to the bone by the IBBC technique has been maintained for long term. We think that the result was brought by the biological integration between bone and HA granules. In conclusion, this study has shown satisfactory results of the cemented THA with ceramic head combined with PE cup for 19–22 years.

We compared the complications and outcome of tibial lengthening using the Ilizarov method with and without the use of a supplementary intramedullary nail. In a retrospective case-matched series assembled from 176 patients with tibial lengthening, we matched 52 patients (26 pairs, group A with nail and group B without) according to the following criteria in order of importance: 1) difference in amount of lengthening (± 2 cm); 2) percentage difference in lengthening (± 5%); 3) difference in patient’s age (± seven years); 4) aetiology of the shortening, and 5) level of difficulty in obtaining the correction. The outcome was evaluated using the external fixator index, the healing index and an outcome score according to the criteria of Paley. It was found that some complications were specific to group A or B respectively, but others were common to both groups.

The outcome was generally better in lengthenings with a nail, although there was a higher incidence of rectifiable equinus deformity in these patients.

Background: Metal on metal articulation is known to reduce wear and subsequent development of osteolysis. However, long-term results of THA using metal on metal articulation is not well validated, especially in young patients.

Methods: Ninety-three THA were performed in 78 patients who were younger than 50 years of age at index surgery. The mean age of the patients was 37 years old. One patient (1 hip) had had a resection arthroplasty due to deep infection, 1 patient (1 hip) had performed stem revision because of periprosthetic fracture and 2 patients died before ten years follow-up and were excluded. Five patients (5 hips) were lost to follow-up before 10 years. Sixty-nine patients (84 hips) were available for complete clinical and radiographic analysis after minimum 10 years follow-up(range, 10 – 14 years).

Results: The mean preoperative Harris hip score of 49 points improved to 92 points at the time of last follow-up. Twenty hips(21.5%) showed variable degrees of osteolysis. Three patients underwent revision surgery because of focal pelvic osteolysis in one, aseptic loosening with extensive pelvic osteolysis of acetabular component in two. Three subsidence of femoral stem in other patients were identified.

Conclusions: At a minimum 10 years after THA using metal-on-metal articulation, it showed good results with regard to aseptic loosening in this group of young patients. However, relatively high rate of osteolysis in this articulation remains problematic and needs further investigation.

The osseointegration of implants is related to the early interactions between osteoblastic cells and titanium surfaces. The behavior of osteoblast cells was compared on four different titanium surfaces in vitro and in vivo: machined, blasted, plasma spray and micro-arc oxidation.

X-ray diffraction and scanning electron microscope investigations were performed in order to assess the structure and morphology. Biologic and morphologic responses to the osteoblast cell lines (Saos-2) were then examined, using Promega proliferation assay, alkaline phosphatase activity, vβ3 integrin expression and cytoskeleton staining (Rhodamine-Phallodine). The analysis of gene expression for osteocalcin and collagen I was done through RT-PCR. In addition, differential histologic evaluation and interfacial strength at the bone-implant interfaces were then evaluated in the distal femur of four beagle dogs.

In conclusion, micro-arc oxidation of titanium appears to exhibit more favorable osteoblast adhesion and stronger interfacial strength than the compared groups in vitro and in vivo as well.

We evaluated the outcome of hemiarthroplasty with bone block graft and low profile prosthesis (Aequalis^® fracture prosthesis) for the comminuted proximal humerus fractures. Sixteen low profile prostheses were used since July 2004, and 11 patients were followed-up for average 19.9 (12–30) months. Their mean age was 67.3 (52–78) years. Cemented stem in all cases. Two bone block graft and cancellous chip bone from resected humeral head. Ten cases for Neer type 4 fracture, one case for type 3 fracture. During 6 weeks, abduction brace with neutral rotation position was maintained. Passive and active range of motion exercise started at 6 weeks. Pain and satisfaction visual analog scale (VAS), range of motion, and modified UCLA score for hemiarthroplasty were evaluated at every visit. Radiography was also checked for stem position, loosening, and tuberosity union.

Mean pain VAS was 2.7 (0–5), and mean satisfaction VAS was 8.4 (5–10). Mean active forward flexion was 137o (90–170), external rotation at side was 45.5o (25–70), and internal rotation at back was T10 (T7-L1). Modified UCLA score was 19 (12–30) at final visit. All stems were stable, and there were no loosening at the final follow-up. All tuberosities were united except two tuberosity absorptions. One complication case was infection.

The outcome of hemiarthroplasty with bone block graft and low profile prosthesis was comparable to other implants for comminuted proximal humerus fractures. This system had unique advantages for tuberosity union. Further study with more patients and longer follow-up period are necessary to clarify the effectiveness of this prosthesis.

Aseptic loosening induced by wear debris of polyethylene (PE) is the most common cause of long-term total hip arthroplasty failure. In the previous studies, we reported that the protruding contour and surface morphology of metallic femoral head brought an increase of PE wear. Alumina ceramics is advantageous (neutral shape and smooth surface) for precision machining compared with metal materials, because hardness of ceramics is higher than that of metal materials. In this study, we measured the roundness and the roughness of retrieved alumina ceramic and metallic heads, aiming to evaluate the change of surface morphology of those heads in vivo.

Fourteen retrieved alumina ceramic femoral heads (Kyocera Corp., currently Japan Medical Materials Corp.) were examined: ten femoral heads were made of small grain-size alumina ceramic (SG-alumina; mean grain size is 3.4 um) with a diameter of 28 mm, with clinical use for 16–28 years (mean 22 years) and four femoral head was made of extra-small-grain size alumina ceramic (XSG-alumina; mean grain size is 1.3 um) with a diameter of 26 mm, with clinical use for 14–19 years (mean 16 years). Six retrieved metallic femoral heads with average clinical use for 12–28 years (mean 18 years) were examined: a diameter of from 22 to 32 mm (e.g. Zimmer Inc., Stryker Corp.) The roundness of the retrieved femoral heads was measured by a contour tracer. The surface roughness in the contact area and the non-contact area of the retrieved femoral heads was measured by a surface roughness tester.

Out-of-roundness of SG-alumina and XSG-alumina heads was 0.15 um and 0.19 um, respectively. In contrast, that of metal heads was 2.43 um, and the profiles were in wide distortion compared with both alumina heads. The surface roughness was 0.012 um in the contact area, and 0.009 um in the non-contact area of retrieved SG-alumina heads. The surface roughness in the contact area, 0.007 um, of XSG-alumina was slightly higher than that in the non-contact area, 0.003 um, and the both area of XSG-alumina represent lower value than SG-alumina, with all alumina heads having a reentrant surface profile. In contrast, the surface roughness of metallic heads was in a range of 0.003–0.053 um and several heads showed the protrusion surface profile.

In this retrieval study, the roundness and the roughness of both alumina ceramic femoral heads after long-term clinical use were low and stable compared with metallic heads. And also, the surface roughness increased in the order of XSG-alumina < SG-alumina < metallic head. The alumina ceramic femoral head showed the reentrant surface whereas the metallic head showed the protruding surface. When third-body wear occurs during the clinical use, generally reentrant form may occur on the ceramic surface whereas protrusion form may occur on the metallic surface. We have good clinical results more than 20 years using the SG-alumina, and clinical results for a long term will be expected with XSG-alumina of improved microstructure.

Despite the well-documented improvement in coronal alignment achieved by computer assisted navigation, varying results have been reported for sagittal alignment. Current navigation systems rely on a sagittal femoral mechanical axis identified by the navigation system, but little information is available on the relationship between the sagittal mechanical axis and anatomical axes for intra-operative or postoperative radiographic assessments. We asked whether deviations exist between sagittal femoral mechanical axis and anatomical axes and attempted to identify predictors of the deviations found.

In 100 consecutive patients (200 knees) undergoing TKA, angles between two anatomical axes (the anterior cortical line and mid-medullary line) and two sagittal mechanical axes identified by current navigation systems were measured as proxies of the deviations between them on true lateral radiographs of the whole femur. Correlation analyses and multivariate regression were carried out to identify predictors of deviations.

Significant deviations existed with wide ranges between the anatomical axes and the sagittal mechanical axes. Degree of femoral bowing and femoral length were found to be predictors of deviations between sagittal femoral mechanical axes and anatomical axes.

This study suggests that surgeons applying navigation technology to TKA need to consider deviations between the sagittal femoral mechanical axes and anatomical axes when they intend to place a femoral component at a target sagittal orientation with respect to an anatomical reference.

Recently, it has been reported that the posterior stabilised implant clinically used for the total knee replacement (TKR) may have a risk of failures caused by pressure and stress concentrated on the tibial post. Malalignment of the implant or variable loading applied to the implant are one of the major causes of the failure in posteriori stabilised TKR. The purpose of this study is to biomechanically analyse the effect of implant malalignment on the failure risk of the implant in posteriori stabilised TKR by estimating von-Mises stress on the implant.

Finite element models of a knee joint and a posteriori stabilised implant were developed from 1mm slices of CT images and 3D CAD software, respectively. The posterior stabilised implant consists of a femoral component, a tibial post, and a tibial tray. The finite element models of TKR for the neutral alignment case as well as the different malalignment cases (3° and 5° of valgus and varus angulations, 2° and 4° of anterior and posterior tilts, and 3° of external rotation) were developed. Then, the von-Mises stress, which is which was chosen as the fracture risk parameter, acting on the implant were analysed by using CAE software. Loading condition at the 40% of one whole gait cycle such as 2000N of compressive load, 25N of anterior-posterior load, and 6.5Nm of torque was applied to the TKR models.

The maximum von-Mises stresses were concentrated on the anterior region of the tibial post regardless of the oblique loadings. In the rotationally additional loading (3° of external rotation), excessive stresses occurred in the anterior medial and posterior lateral areas. The maximum stress was 18.3MPa in neutral position. The maximum stress increased by 10% in anterior tilt 2°, 15% in anterior tilt 4°, 25% in posterior tilt 2°, 54% in posterior tilt 4°, 116% in varus 3°, 262% in varus 5°, 318% in valgus 3°, 389% in valgus 5°, 6% in external rotation 3° compared with that in the neutral position case. In addition, 32.0MPa of maximum stress occurred on the posterior lateral area of the base component in rotationally additional loading.

The results showed that the implant malalignment could accelerate the stress concentration on the anterior region of the tibial post as in the result of clinical study. In the case of additional rotation, high stress concentration on the anterior medial and posterior lateral areas as well as on the tibial base surface could generate wear or fracture of tibial post. From the additional rotation case, we can expect that higher conformity implant will generate higher stress concentrations than lower conformity implant even though we did not compare the effect of conformity ratio on the stress concentration in the tibial polyethylene component. This study showed that careful consideration of the implant malalignment would be necessary to improve the clinical outcome in the posteriori stabilised TKR.

We report the case of a 24-year-old man with a congenital meniscoid articular disc of the triangular fibrocartilage complex with extensor carpi ulnaris tenosynovitis. His young age, the normal articular cartilage, the lack of degenerative changes at the margins of the defect and its bilateral occurrence made this diagnosis likely. A congenital defect of the articular disc of the triangular fibrocartilage complex should not be misinterpreted as a traumatic rupture and is usually asymptomatic.

There are few data available regarding the association between hallux valgus and pain or functional limitation. We determined the prevalence of hallux valgus in a rural Korean population aged between 40 and 69 years, and its association with pain and function. A total of 563 subjects was examined using the foot health status questionnaire, the Short Form-36 questionnaire and weight-bearing anteroposterior radiographs.

Hallux valgus was present in 364 subjects (64.7%). It did not significantly correlate with age and was more common in women. Of the 364 subjects, 48 (13.2%) had moderate or greater deformity, defined as a hallux valgus angle > 25°. This was significantly associated with pain, worse function and worse foot health. The putative risk factors associated with painful hallux valgus were female gender, low educational attainment and the presence of pain in the knee.

We present the operative technique and clinical results of concomitant reconstruction of the medial collateral ligament (MCL) and the posterior oblique ligament for medial instability of the knee using autogenous semitendinosus tendon with preservation of the tibial attachment. The semitendinosus tendon graft between the screw on the medial epicondyle and the tibial attachment of the graft was overlapped by the MCL, while the graft between the screw and the insertion of the direct head of the semimembranosus tendon was overlapped by the central arm of the posterior oblique ligament. Assessment was by stress radiograph and the Lysholm knee scoring scale. After a mean follow-up of 52.6 months (25 to 92), the medial joint opening of the knee was within 2 mm in 22 of 24 patients. The mean Lysholm score was 91.9 (80 to 100).

Concomitant reconstruction of the MCL and posterior oblique ligament using autogenous semitendinosus tendon provides a good solution to medial instability.

Between March 2000 and February 2006, we carried out a prospective study of 100 patients with a low-grade isthmic spondylolisthesis (Meyerding grade II or below), who were randomised to receive a single-level and instrumented posterior lumbar interbody fusion with either one or two cages. The minimum follow-up was for two years. At this stage 91 patients were available for review. A total of 47 patients received one cage (group 1) and 44 two cages (group 2). The clinical and radiological outcomes of the two groups were compared.

There were no significant differences between the two groups in terms of post-operative pain, Oswestry Disability Score, clinical results, complication rate, percentage of post-operative slip, anterior fusion rate or posterior fusion rate. On the other hand, the mean operating time was 144 minutes (100 to 240) for patients in group 1 and 167 minutes (110 to 270) for those in group 2 (p = 0.0002). The mean blood loss up to the end of the first post-operative day was 756 ml (510 to 1440) in group 1 and 817 ml (620 to 1730) in group 2 (p < 0.0001).

Our results suggest that an instrumented posterior lumbar interbody fusion performed with either one or two cages in addition to a bone graft around the cage has a low rate of complications and a high fusion rate. The clinical outcomes were good in most cases, regardless of whether one or two cages had been used.

We undertook a retrospective review of 24 arthroscopic procedures in patients with symptomatic ossicles around the malleoli of the ankle. Most of the patients had a history of injury and localised tenderness in the area coinciding with the radiological findings. Contrast-enhanced three-dimensional fast-spoiled gradient-echo MRI was performed and the results compared with the arthroscopic findings. An enhanced signal surrounding soft tissue corresponding to synovial inflammation and impingement was found in 20 patients (83%). The arthroscopic findings correlated well with those of our MRI technique and the sensitivity was estimated to be 91%. At a mean follow-up of 30.5 months (20 to 86) the mean American Orthopaedic Foot and Ankle Society score improved from 74.5 to 93 points (p < 0.001). Overall, the rate of patient satisfaction was 88%.

Our results indicate that symptomatic ossicles of the malleoli respond well to arthroscopic treatment.

This study aimed to evaluate the use of pin leverage in the reduction of Gartland type III supracondylar fractures of the humerus in children. The study comprised 95 children, who were split into three groups according to the type of method of reduction used. Group 1, had an open reduction, group 2, had closed reduction and percutaneous pin fixation and group 3, the pin leverage technique. Each group was analysed according to the time to surgery, the duration of the procedure, the incidence of complications, and the clinical and radiological outcome.

The mean duration of the operative procedure in groups 1, 2 and 3 was 119 minutes (80 to 235), 57 minutes (20 to 110) and 68 minutes (30 to 90), respectively. At a mean follow-up of 30 months (12 to 63) the clinical results were declared excellent or good in all children and the radiological results intermediate in five patients in group 2. The results of the closed reduction using the pin leverage technique was classified as failure in two children.

Our findings lead us to believe that the pin leverage method of reduction gives good results in the treatment of Gartland type III fractures.

Arrest of growth of the distal radius is rare but will produce deformity of the wrist. We corrected angular deformity and shortening of the distal radius by epiphysiolysis and gradual lengthening without a corrective osteotomy.

Patella infera can cause knee pain and lead to patellofemoral osteoarthritis. Treatment is usually unsatisfactory. We describe a case of severe patella infera after operative treatment for fracture of the patella. We used Ilizarov external fixation and gradual lengthening of the patellar tendon. The patellar height was restored and the patient’s symptoms were much improved.

We performed 114 consecutive primary total hip arthroplasties with a cementless expansion acetabular component in 101 patients for advanced osteonecrosis of the femoral head. The mean age of the patients at surgery was 51 years (36 to 62) and the mean length of follow-up was 110 months (84 to 129).

The mean pre-operative Harris hip score of 47 points improved to 93 points at final follow-up. The polyethylene liner was exchanged in two hips during this period and one broken acetabular component was revised. The mean linear wear rate of polyethylene was 0.07 mm/year and peri-acetabular osteolysis was seen in two hips (1.9%). Kaplan-Meier analysis indicated that the survival of the acetabular component without revision was 97.8% (95% confidence interval 0.956 to 1.000) at ten years.

Our study has shown that the results of THA with a cementless expansion acetabular component and an alumina-polyethylene bearing surface are good.

Aims: To evaluate the outcomes of the primary total hip arthroplasties using nonmodular cementless acetabular component with titanium mesh coating þxed by press-þt technique. Methods: Eighty-two primary total hip arthroplasties in 75 patients were performed consecutively. Sixty-two hips were eligible for follow up of average 62 months (range, 48–84). The mean age was 59 years. The clinical evaluation was done by modiþed Harris hip score (HHS) and radiologic evaluation including stability of component, polyethylene wear rate (Dorr method) and remodeling pattern was done. Results: Mean HHS improved from 50.2 points preoperatively to 90.5 points at the last follow up. Excellent or good results were found in 52 hips (84%). All components were stable radiologically. The average thickness of polyethylene was 13.06mm. The linear polyethylene wear rate was 0.073mm/years (range, 0.01–0.23). Wear rate was correlated with the thickness of polyethylene signiþcantly (p=0.049). Any pelvic osteolysis was not found. The polar gap was found in 25 hips (40%) at initial radiographs and has disappeared during follow up in 22 hips (88%). One hip was revised due to chronic unreduced dislocation. There were 9 heterotrophic ossiþcations, 6 nonrecurrent dislocations, and 2 transient sciatic nerve palsies. Conclusion: Total hip arthroplasty using nonmodular cementless acetabular component seemed to enhance satisfactory early mid-term result in terms of stability and acetabular remodeling with minimal wear and pelvic osteolysis.

Aims: To evaluate the early midterm outcomes of primary total hip arthroplasty (THA) using Hydroxyapatite (HA)-coated on smooth surface acetabular component with 28 mm metal head on polyethylene liner articulation. Methods: Seventy primary THA in 63 patients with HA-coated acetabular component were performed consecutively between June 1993 and August 1996. Fifty-four cases were eligible for follow-up of average 71 months (48–104) and the mean age of index operation was 49 years (23–71). The clinical results were analyzed by modiþed Harris hip score, and the radiologic evaluation in terms of stability, polyethylene wear rate (Dorr method), osteolysis around acetabular component was done. Results: Mean Harris hip score improved from 50.9 to 82.2 at the last follow-up. Excellent or good results were found in 38 cases (70%). Eight cases (15%) were unstable radiologically. Pelvic osteolysis was found at 18 cases (33%). The mean polyethylene wear rate was 0.146 mm/year (0.01–0.45). Wear rate of hip dyaplasia was greater than osteonecrosis signiþcantly (p< 0.05). Seven cases (13%) were revised (5 mechanical failures, 2 deep infections). Any bone ongrowth was not found during revision surgery for loose components. Complications included 5 heterotrophic ossiþcations, 2 deep infections, and 1 nonrecurrent dislocation. Conclusion: Primary THA using HA-coated on smooth surface acetabular component showed unsatisfactory clinical results, accelerated polyethylene wear rate accompanying high incidence of osteolysis, and high loosening rate due to lack of bony ongrowth at early midterm.

Introduction: The purpose of this study was to compare the results of the efficacy of two decompressive methods (multiple drilling vs standard core decompression) for the treatment of precollapse osteonecrosis of the femoral head.

Methods: The results in a consecutive series of 54 patients (65 hips) who had undergone multiple drilling (31 patients, 35 hips) or core decompression (23 patients, 30 hips) for the treatment of precollapse osteonecrosis of the femoral head between September 1991 and July 2001 were reviewed. The average duration of follow up was 60.3 months (range, 24–103 months) in the multiple drilling group and 44.8 months (range, 24 to 84 months) in the core decompression group. The presence of collapse and radiographic progression in each group was evaluated prospectively with collapse of the femoral head defined as a failure. Harris hip scores (HHS) were used to evaluate clinical status preoperatively and at the most recent follow up.

Results: Radiographically and clinically, high failure was significantly related to the larger size and laterally located lesion (LHI of less than 12%, Urbaniak IIC, Ohzono IC and Kerboul index of more than 240 degrees) in both groups. The average preoperative and the last HHS was 86.7 to 73.7 in the core decompression group and 87.0 to 74.6 in the multiple drilling group. Compared to the core decompression group, the multiple drilling group had significantly longer times before collapse (mean 42.3 months vs 22.6 months, p=0.011) and a lower rate of collapse within 3 years after operation (55.0% vs 85.7%, p=0.03).

Discussion: Decompressive methods have worse outcomes in case of lesions of larger size and lateral location, even in precollapse stage. Multiple drilling has significantly longer time before collapse and a lower rate of collapse within 3 years after operation than standard core decompression.

According to the knee simulator test results in 1970s, the total decrease in thickness of UHMWPE tibial tray in combination with ceramic femoral component [F-Comp] was less than one tenth as that of the combination with metal [1]. These advantages led to development of total knee prosthesis [TKP] with alumina ceramics. In this study, we report the wear surface observation, the clinical wear and the oxidation of the retrieved TKP used clinically for 23 years, comparing with a metal TKP.

The retrieved TKP was implanted in 1979, and retrieved on January 9th in 2002. This TKP consisted of an alumina ceramic F-Comp and a UHMWPE tray combined with a alumina ceramic tibial component. Observations of the surface of alumina F-Comp and UHMWPE tray were carried out using SEM. Shape of UHMWPE tray was determined three-dimensionally. Comparing the result with original shape based on the product’s plan, liner wear and volumetric wear were calculated. Oxidation index was determined by Fourier transform infrared spectrophotometry.

Alumina F-Comp did not have any scratch on the surface by seeing with naked eye. UHMWPE tray had deformation and scratches obviously. The liner wear rate was 37 micrometer/year and volumetric wear rate was 18.8 mm3/year. The oxidation indexes were 0.6 in the unworn area, 1.2 in the worn area and 0.2 in the inner area.

SEM observations of the F-Comp demonstrated no scratch or pit. In contrast, many scratches were clearly observed on the UHMWPE tray. However, higher magnification observations did not demonstrate severe wear, which was shown on the wear analysis of a metallic F-Comp. Oxidation degradation is a problem to solve. However, the low wear rate and mild wear pattern demonstrate that ceramic F-Comp reduced UHMWPE wear.

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.

Objectives: To assess the early diagnostic procedures and results of treatment for pyogenic discitis and to propose the ideal method of treatment for it.

Materal and Methods: 35 patients underwent open discectomies : 24 males and 11 females. 34 had single level and one had two-level discectomies. Blood were analysed on pre- and postop 3rd, 7th, 14th days, and 6 weeks. MRI exam in 6 patients and bone scintigraphy in 3 were done. Clinical symptoms of infection was observed on the postop 7 day on average. The characteristic features were back pain with muscle spasm, muscle cramping in legs, malaise, mild fever. 32 had conservative treatment and two had anterior radical surgery. Tobramycin, cloxacillin, and clindamycin were used for 4–6 weeks.

Results: WBC, ESR, CRP and body temperatures (BT) at postop 3rd, 7th and 14 days, and 6 weeks were checked; WBC were 11,500, 13,000, 9,300, 6,300 respectively: ESRs at one hour were 39, 50, 46, and 26mm : CRPs were 16.8, 23.5, 8.1 and 2.5. BT on average at postop 3rd, 7th and 14th days were 37.6, 37.4 and 37.2. Muscle spasm subsided together with cramping in legs 7–12 days after chemotherapy, but back pain persisted even after control of infection in most of the cases. MRI disclosed the infection in 5 of 6 cases, while in all 3 bone scans were positive. Infection was controlled in all. In 2 cases bony destruction advanced during chemotherapy, and in 2 other cases after anterior surgery infection exacerbated and spreaded to the neighbouring bone and joints.

Conclusion: Antibiotic therapy is found sufficient in controlling discitis, and surgery should be reserved for the patients without response to antibiotics.

We report the long-term radiographic results of the total hip arthroplasty with use of the cementless porous coated Harris-Galante (H-G) stem. Seventy-five consecutive patients, eighty-eight hips formed the basis of this study. Fifty patients were male, twenty-five patients were female, and thirteen patients were bilateral. The mean age of patients at operation was 42 years. They were followed up for an average of thirteen years four months (ten years two months to fourteen years four months). The diagnosis was avascular necrosis of the femoral head in 49 cases, degenerative osteoarthritis in 32 cases. Clinical results were estimated by modified Harris hip score and thigh pain, and radiographic results by periodically checked plain X-ray film. The average Harris hip score increased from 60 points preoperatively to 83 points at the most recent follow-up examination. The hip pain score increased from 31 points to 41 points. Clinically severe thigh pain was observed in 3 cases (4%). In radiographic evaluation, subsidence more than 5mm was seen in 2 cases (2%). Periprosthetic osteolytic lesion was observed in 15 cases (17%), but the lesions do not influence stability of the stem. Femoral stem stability by Engh was stable in 72 cases, fibrous stable in 12 cases, unstable in 4 cases. Pedestal formation, cortical hypertrophy of the distal femur, and stress shielding was observed more than 40%. Subcollar resorption was identified in 29% and ectopic ossification in 15%. Revision of the femoral stem was needed in 4 cases for aseptic loosening. At 10 years probability of survival of the stem using Kaplan-Meyer method was 95.5%. Use of the cementless H-G stem yielded the excellent long-term outcome, but osteolysis and stress shielding would be the main problems to solve.

We treated 52 patients with impingement of the anterolateral soft tissues of the ankle by arthroscopic debridement. All had a history of single or multiple inversion injuries, without instability. One half had negative stress radiographs (stable group), while the others were positive (unstable group). Their mean age was 31 years and there were 35 men and 17 women. The results were assessed at a mean follow-up of 30 months.

Three patients (6%) had a fair result, while 49 (94%) had an excellent or good outcome. No difference was found in the final results between the two groups (p > 0.05). We conclude that anterolateral impingement of the ankle should be considered in a patient with chronic anterolateral pain after an injury, regardless of the stability of the ankle.

Cancer-induced bone diseases are often associated with increased bone resorption and pathological fractures. In recent years, osteoprotective agents such as bisphosphonates have been studied extensively and have been shown to inhibit cancer-related bone resorption in experimental and clinical studies. The third-generation bisphosphonate, ibandronate (BM 21.0955), is a potent compound for controlling tumour osteolysis and hypercalcaemia in rats bearing Walker 256 carcinosarcoma.

We have studied the effect of ibandronate given as an interventional treatment on bone strength and bone loss after the onset of tumour growth in bone. Our results suggest that it is capable of preserving bone quality in rats bearing Walker 256 carcinosarcoma cells. Since other bisphosphonates have produced comparable results in man after their success in the Walker 256 animal models our findings suggest that ibandronate may be a powerful treatment for maintaining skeletal integrity in patients with metastatic bone disease.