We retrospectively reviewed 40 hips in 36 patients who had undergone acetabular reconstruction using a titanium Kerboull-type acetabular reinforcement device with bone allografts between May 2001 and April 2006. Impacted bone allografts were used for the management of American Academy of Orthopaedic Surgeons Type II defects in 17 hips, and bulk bone allografts together with impacted allografts were used for the management of Type III defects in 23 hips. A total of five hips showed radiological failure at a mean follow-up of 6.7 years (4.5 to 9.3), two of which were infected. The mean pre-operative Merle d’Aubigné score was 10 (5 to 15) vs 13.6 (9 to 18) at the latest follow-up. The Kaplan-Meier survival rate at ten years, calculated using radiological failure or revision of the acetabular component for any reason as the endpoint, was 87% (95% confidence interval 76.3 to 97.7). A separate experimental analysis of the mechanical properties of the device and the load-displacement properties of bone grafts showed that a structurally hard allograft resected from femoral heads of patients with osteoarthritis should be preferentially used in any type of defect. If impacted bone allografts were used, a bone graft thickness of < 25 mm was acceptable in Type II defects.

This clinical study indicates that revision total hip replacement using the Kerboull-type acetabular reinforcement device with bone allografts yielded satisfactory mid-term results.

We report the mid- to long-term (mean 20.3 years, 10 to 32.5) results of the Chiari pelvic osteotomy in patients with pre- to advanced stage osteoarthritis in dysplastic hips. We followed 163 Japanese patients (173 hips) with a mean age at surgery of 20 years (9 to 54). Overall, 124 hips (72%) had satisfactory results, with Harris hip scores ≥ 80. Satisfactory results were seen in 105 of 134 hips with pre- or early osteoarthritis (78%) and 19 of 39 hips with advanced osteoarthritis (49%). A total of 15 hips (9%) underwent a total hip replacement (THR) with a mean interval between osteotomy and THR of 16.4 years. With conversion to THR as the endpoint, the 30-year survival rate was 85.9% (95% confidence interval 82.3 to 89.5). It was 91.8% for patients with pre- or early osteoarthritis and 43.6% for those with advanced osteoarthritis (p < 0.001).

We now perform the Chiari osteotomy for patients with dysplastic hips showing poor joint congruency and who prefer a joint-conserving procedure to THR.

We have reviewed 38 surgically treated cases of spontaneous posterior interosseous nerve palsy in 38 patients with a mean age of 43 years (13 to 68) in order to identify clinical factors associated with its prognosis. Interfascicular neurolysis was performed at a mean of 13 months (1 to 187) after the onset of symptoms. The mean follow-up was 21 months (5.5 to 221). Medical Research Council muscle power of more than grade 4 was considered to be a good result. A further 12 cases in ten patients were treated conservatively and assessed similarly.

Of the 30 cases treated surgically with available outcome data, the result of interfascicular neurolysis was significantly better in patients < 50 years old (younger group (18 nerves); good: 13 nerves (72%), poor: five nerves (28%)) than in cases > 50 years old (older group (12 nerves); good: one nerve (8%), poor: 11 nerves (92%)) (p < 0.001). A pre-operative period of less than seven months was also associated with a good result in the younger group (p = 0.01). The older group had a poor result regardless of the pre-operative delay.

Our recommended therapeutic approach therefore is to perform interfascicular neurolysis if the patient is < 50 years of age, and the pre-operative delay is < seven months. If the patient is > 50 years of age with no sign of recovery for seven months, or in the younger group with a pre-operative delay of more than a year, we advise interfascicular neurolysis together with tendon transfer as the primary surgical procedure.

We present a case of post-traumatic osteonecrosis of the radial head in a 13-year-old boy which was treated with costo-osteochondral grafts. A satisfactory outcome was seen at a follow-up of two years and ten months.

Although costo-osteochondral grafting has been used in the treatment of defects in articular cartilage, especially in the hand and the elbow, the extension of the technique to manage post-traumatic osteonecrosis of the radial head in a child has not previously been reported in the English language literature. Complete relief of pain was obtained and an improvement in the range of movement was observed. The long-term results remain uncertain.

Purpose: There is no report concerning about long-term comparison result of high placed cementless cup stability with or without screws for developmental dysplasia of the hip. The aim of this study was to ascertain whether or not there are any differences in high placed cementless cup stability with or without screws at the mean 10-year (6–14) follow-up period.

Method: We divided 109 hip-cases who underwent identical cementless total hip arthoplasty system (Mallory – Head : Biomet Inc.) to two groups: 57 cups with screw (screw group) and 52 cups without screw (no screw group). No case in both group underwent bulk bone graft for acetabular roof. Radiographic signs of cup instability were defined as the development of radiolucent line (> 2mm) or migration (> 4mm). Degree of subluxation by Crowe classification, cup size and cup abduction angle were also measured.

Results: In both groups, there was no significant difference in terms of degree of subluxation (each grade’s %) (screw vs no screw = I (68, 73), II (21, 25), III (11,0), IV (0, 2)), age (yrs) (58, 60), cup size (mm) (46, 47) and cup abduction angle (49, 47). In screw group, one case was revised by replacing only polyethylene insert due to excessive ware. No case in both group showed any sign of component instability.

Conclusion: High placed Mallory-Head type cementless cup without screws showed stable radiographic fixation as well as cup with screws at mean 10 years follow-up period.

Removal of femoral bone cement is required for preparation of proper implant bed for reimplantation of a new femoral component in revision total hip arthroplasty. Several devices and procedures have been developed for cement removal, including an extracorporal shock-wave lithotripter and YAG laser, as well as a high-powered drill or burr under the control of conventional fluoroscopic images and an intrafemoral endoscopy. Ultrasonic tools are efficient for removal of bone cement with minimal damage to bone. We use a high-powered burr to remove the deep femoral bone cement under the control of conventional fluoroscopic images, although the problem of this procedure is large exposure of X-ray and two dimensional viewing of burr position which can result in perforation in the third plane.

Computer-assisted fluoroscopic navigation system allows the surgeons to provide positional information about surgical instrument to target bones during operations. Two-dimensional image data are obtained using the fluoroscope with a reference frame and stored on a computer workstation. A camera interfaced with the computer then tracks the position of the patient and registered surgical instruments during the procedure. Taking advantage of the real-time guidance of computer-assisted fluoroscopic navigation system, we introduce a valuable technique using computer-assisted fluoroscopic navigation system for performing removal of the cement of the femoral canal in revision cemented total hip arthroplasty.

Titanium alloys such as Ti-6Al-4V and Ti-6Al-7Nb have been widely used as orthopedic implants such as artificial hip joint, because of their high mechanical strengths and good biocompatibilities. Recently, new kinds of titanium-based alloys free from elements such as V and Al, which are suspicious for cytotoxicities, are being developed. Ti-15Zr-4Ta-4Nb (Ti-15-4-4) is one of such alloys and shows high mechanical strength and corrosion resistance which are comparable to those of the Ti-6Al-4V alloy. In the present study, chemical treatments for providing bone-bonding ability to this alloy were investigated. Apatite-forming ability in a simulated body fluid (SBF) was used as an indication of the bone-bonding ability.

Ti-15-4-4 alloy plates 10×10×1 mm3 in size were soaked in 5M-NaOH solution at 60 °C for 24 h, soaked in 100mM-CaCl2 solution at 40 °C for 24 h, heated at 600 °C for 1 h and then soaked in hot water at 80 °C for 24 h. Surface structural changes of the alloy with these treatments were analyzed by a field emission scanning electron microscope (FE-SEM) attached with an energy-dispersive X-ray spectrometer (EDX), Thin-film X-ray diffraction (TF-XRD) and Fourier transform confocal laser Raman spectroscopy (FT-Raman). Scratch resistance of surface layer of the alloy was measured by a thin-film scratch tester. Apatite-forming ability of the specimens was examined by soaking them in SBF for 3 days. Long-term stability of the apatite-forming ability was examined after keeping the specimens in an incubator with relative humidity of 95 % at 80 °C for 1 week.

A sodium hydrogen titanate layer about 500 nm in thickness was formed on the surface of the alloy by the NaOH treatment. This specimen formed some amounts of apatite in SBF within 3 days, but its scratch resistance was as low as less than 10 mN. When the NaOH-treated specimen was subsequently heat treated, the sodium hydrogen titanate transformed into sodium titanate to give scratch resistance as high as 92 mN, but lost its apatite-forming ability.

When the NaOH-treated specimen was soaked in CaCl2 solution, the sodium hydrogen titanate was isomorphously transformed into calcium hydrogen titanate. Thus treated specimen increased its apatite-forming ability, but its scratch resistance was still low. When the NaOH- and CaCl2-treated specimen was subsequently heat treated, the calcium hydrogen titanate transformed into calcium titanate to give scratch resistance as high as 169 mN. However, its apatite-forming ability was lost. Thus treated specimen was then soaked in hot water. As a result, its apatite-forming ability remarkably increased without decreasing scratch resistance. It showed high apatite-forming ability even after a long-term-stability test.

The NaOH-, CaCl2-, heat- and hot-water-treated Ti-15-4-4 alloy is believed to be promising materials for artificial joints, because of its high apatite-forming ability with long-term stability as well as high scratch resistance.

Kokubo and one of the present authors (T.N) have developed a new technique of bioactive coating using alkaline and heat treatment, which induces the formation of a thin HA layer on the surface of titanium after implantation in the body. This new coating technique is not associated with degradation or separation of the HA coating, because a bone-like apatite layer of 1 μm in width begins to form in the body tissue after implantation.

Chemically and thermally treated titanium possesses bone-bonding ability, which has been confirmed by detachment tests. Bone ingrowth into bioactive titanium continues to increase throughout the 26 weeks of implantation, whereas bone ingrowth into non-treated or HA plasma coating implants tends to decrease between 6 and 12 weeks. These findings suggest the long-term stability and osteoconduction of the bioactive layer of chemically and thermally treated titanium.

We carried out a series of 70 cementless primary total hip arthroplasties using this coating technique on a porous titanium surface, and followed up the patients for a mean period of 4.8 years. There were no instances of loosening or revision, or formation of a reactive line on the porous coating. Although radiography just after surgery showed a gap between the host bone and the socket in 70% of cases, all the gaps disappeared within a year, indicating the good osteoconduction provided by the coating. Alkaline-heat treatment of titanium to provide a HA coating has several advantages over plasma-spraying, including no degeneration or absorption of the HA coating, simplicity of the manufacturing process, and cost effectiveness. In addition, this method allows homogeneous deposition of bone-like apatite within a porous implant.

Although this was a relatively short-term study, treatment that creates a bioactive surface on titanium and titanium alloy implants has considerable promise for clinical application.

A total of 118 consecutive patients with a fracture of the distal radius were treated with a volar locking plate; 50 patients had no ulnar styloid fracture, 41 had a basal ulnar styloid fracture, and 27 had a fracture of the tip of the ulnar styloid. There were no significant differences in radiological and clinical results among the three groups. The outcome was good and was independent of the presence of a fracture of the ulnar styloid. A total of five patients (4.2%) had persistent ulnar-sided wrist pain at final follow-up. Nonunion of the ulnar styloid fracture did not necessarily lead to ulnar wrist pain. Patients with persistent ulnar pain had a higher mean initial ulnar variance and increased post-operative loss of ulnar variance.

The presence of an associated ulnar styloid fracture of the ulnar styloid does not adversely affect the outcome in patients with a fracture of the distal radius treated by volar plating.

We reviewed 44 consecutive revision hip replacements in 38 patients performed using the cement-in-cement technique. All were performed for acetabular loosening in the presence of a well-fixed femoral component. The mean follow-up was 5.1 years (2 to 10.1). Radiological analysis at final follow-up indicated no loosening of the femoral component, except for one case with a continuous radiolucent line in all zones and peri-prosthetic fracture which required further revision. Peri-operative complications included nine proximal femoral fractures (20.4%) and perforation of the proximal femur in one hip. In five hips wiring or fixation with a braided suture was undertaken but no additional augmentation was required. There was an improvement in the mean Japanese Orthopaedic Association score from 55.5 (28 to 81) pre-operatively to 77.8 (40 to 95) at final follow-up (p < 0.001). Revision using a cement-in-cement technique allows increased exposure for acetabular revision and is effective in the medium term. Further follow-up is required to assess the long-term results in the light of in vitro studies which have questioned the quality of the cement-in-cement bond.

A 30-year-old man presented with pain and limitation of movement of the right hip. The symptoms had failed to respond to conservative treatment. Radiographs and CT scans revealed evidence of impingement between the femoral head-neck junction and an abnormally large anterior inferior iliac spine. Resection of the hypertrophic anterior inferior iliac spine was performed which produced full painless restoration of function of the hip.

Hypertrophy of the anterior inferior iliac spine as a cause of femoro-acetabular impingement has not previously been described.

Thigh pain appears often after THA used of the cement-less femoral components, but the appearance mechanism of thigh pain does not have been elucidated. As one factor of manifestation of thigh pain, it has been guessed that the pressure from the inside of medullary cavity of bone by the stem. The purpose of this study is confirming whether the flexor reflex is caused, by using the femur of a rabbit that applied the pressure from the inside of medullary cavity of bone.

Japanese white rabbits with weight of about 3kg were used. Evaluation of the appearance of the pain by the pressure was performed by measurement of the hind leg flexor activity produced by the flexor reflex. After confirming that appearance of the muscles activity by the pain reflex from adding the pain stimulus to the hind leg skin of rabbits, we loaded of the pressure into the inside of medullary cavity of bone and observed whether the muscles activity appears. As the laboratory animals model, we prepared two kinds of rabbits by the difference in the amount of reaming. And we tested how the differences show up between these two kinds of rabbits.

In the rabbits with few amounts of reaming, the flexor reflex appeared in low pressure. But, in the rabbits with many amounts of reaming, the flexor reflex did not appear in high pressure, either.

It is known that the somatic sensory nerves are distributed in the bone, and it is known that the sensory nerve ends exist in the medullary cavity of bone. It was suggested that the pain is induced, when the sensory nerve ends remained in the inside of medullary cavity of bone and the pressure in whicha reaction is possible was carried out there.

We evaluated intermediate-term results of primary cementless Omniflex prostheses.

Forty-nine patients (57 hips) with a mean age of 44 years were observed for an average of 8.6 years.

These results were inferior to those using other recent cementless total hip systems. The increasing prevalence of loosening and osteolysis with time are problems related to this Omniflex femoral component. Although the implant design is unique, the authors no longer use this system.

We have developed bioactive bone cements manufactured from bioactive glass-ceramic powder and BIS-GMA resin, which has the bone-bonding ability. In the present clinical trial, this bioactive bone cement was used for fixation of total hip arthroplasty (THA) and the clinical results were investigated

Two types of bioactive bone cements (high- and low- viscosity type cements) were prepared (Nippon Electric Glass Co. Ltd.). Inorganic filler contained 72.0 wt% AW-GC (apatite and wollastonite containing glass-ceramic) and 27.0 wt% SiO2 powder. All surgery was performed at Kyoto University Hospital between February and October 1996. 20primary THA (20 patients) were performed using bioactive bone cement as a clinical trial. The average age of the patients was 58 years. The average follow-up period was 6 years, 9 months. The diagnosis for 18 hips at the operation was osteoarthritis and 2 hips were rheumatoid arthritis. All sockets and one stem were fixed by bioactive cement, and all but one stem were fixed by PMMA cement. In all cases all polyethylene socket and titanium stem were used (14 KC type THA and 8 KMAX type THA). For the femoral head 22 mm diameter alumina head was used in all cases.

If the bone cement is bioactive and shows direct bonding with the bone, wear particles can’t enter the interface and thus prevention of loosening due to bone resorption would be expected. This cement demonstrated satisfactory clinical results, proving to be a promising material for implant fixation.

Zirconia ceramic femoral head has better mechanical properties than those alumina head has. However, it is concerning whether the wear of UHMWPE against zirconia head is as low as that of alumina head. We compared polyethylene wears against 22.225mm alumina and zirconia heads in total hip arthroplasties (THA) occupied in our hospital.

Kobelco hip prostheses (Kobelco, Kobe, Japan) were used. Titanium alloy stem was cement-fixed and all-polyethylene acetabular components were articulated with alumina or zirconia femoral heads. In the cases from February 1996 to December 1998, 96 primary cemented total hip arthroplasties (THA) in 87 patients of osteoarthritis were observed with a minimum follow-up of five years. The clinical results were evaluated using JOA hip score (100 in normal hip). There were 46 hips with alumina heads and mean follow-up of 6.2 years, and 51 hips with zirconiaheads and mean follow-up of 5.2 years. Mean ages at operation were 58 years. For each patient, the initial postoperative and the latest anterior-posterior radiographs of the pelvis were selected. With the custom software Image-Pro Plus version 4.0, linear wear and volumetric wear were measured.

Clinical results of both heads showed no difference. Linear wear rate of alumina is 0.080±0.047mm/year, while it is 0.147±0.069mm/year for zirconia, significantly higher than alumina (p?0.0001). Volumetric wear rate of zirconia (42.499±20.233mm3/year) is also significantly higher than alumina (27.049±17.216mm3/year) (p?0.0001).

The low thermal conductivity of zirconia is thought to cause local high temperature, leading to the phase transformation and lower-temperature aging degeneration (LTAD) of zirconia head surface. In order to solve this problem, alumina-adding zirconia compound ceramics with lower phase transformation were developed. Hip simulator test revealed much lower wear rate of improved zirconia. This will be discussed.

Prosthetic impingement after THA is to different for the angle and shape of the implant. Purpose of this study is examine the range of motion(ROM) on a computer when angle and shape of the implant are changed.

The 3D implant models were created on a computer. The angle was measured in the flexion, extension, adduction direction byevery 0.1 degrees. There are three kinds of acetabular abduction angle, two kinds of acetabular anteversion angle and two kinds of femoral anteversion angle. There are three kinds of the radius of neck and the neck shaft angle. All 324 patterns of the above model were measured.

When the radius of neck decreased, the ROM increased in all cases. When the neck shaft angle decreased, the ROM increased by almost all cases. When the acetabular anteversion angle increased, the ROM of flexion direction increased and adduction direction decreased, and as for the extension direction, all the factors had influenced the change in the ROM. When the acetabular angle increased, the ROM of the extension direction increased and the flexion directions decreased. As for adduction direction, femoral anteversion angle, acetabular anteversion angles, and the radius of neck had influenced the ROM. When the femoral anteversion angle increased, the ROM of flexion direction increased and extension, adduction direction decreased.

The clinical ROM is affected by the impingement of non-implant and the strain of the soft tissue. Therefore, It’ s considered that the clinical ROM is smaller than the ROM which was investigated in this study in many cases. When the radius of neck and the neck shaft angle decrease, the increase of the ROM expected. However the radius of the neck should not be decreased too much to avoid the decrease of the neck strength.

We retrospectively evaluated 42 hips which had undergone acetabular reconstruction using the Kerboull acetabular reinforcement device between September 1994 and December 1998. We used autogenous bone chips from the ilium and ceramic particle morsellised grafts, even in large acetabular bone defects, in the early stages of the study. Thereafter, femoral head allograft was used as bulk graft in patients with large acetabular defects. Ceramic blocks and the patients’ contralateral femoral head were also used as bulk graft. The mean follow-up period was 8.7 years (4.3 to 12).

Survivorship analysis was performed using radiological failure of the acetabular component, irrespective of whether it was revised, or not, as the end-point.

The survival rate of the morsellised graft group (25 hips) and the bulk graft group (17 hips) at ten years was 53% (95% confidence interval (CI) 42.5% to 63.5%) and 82% (95% CI 72.4% to 91.6%), respectively. The mid-term results of revision total hip replacement with the Kerboull device were better when bulk graft was used in any size of bone defect.

We compared the outcome of peri-operative humeral condylar fractures in patients undergoing a Coonrad-Morrey semiconstrained total elbow replacement with that of patients with rheumatoid arthritis undergoing the same procedure without fractures. In a consecutive series of 40 elbows in 33 patients, 13 elbows had a fracture in either condyle peri-operatively, and 27 elbows were intact. The fractured condyle was either fixed internally or excised. We found no statistical difference in the patients’ background, such as age, length of follow-up, immobilisation period, Larsen’s radiological grade, or Steinbrocker’s stage and functional class. There was also no statistical difference between the groups in relation to the Mayo Elbow Performance Score, muscle strength, range of movement, or radiolucency around the implants at a mean of 4.8 years (1.1 to 8.0) follow-up.

We conclude that fractured condyles can be successfully treated with either internal fixation or excision, and cause no harmful effect.

In cementless fixation system, surface character becomes important factor. Alkali and heat treatments on titanium metal has been proved to show strong bonding to bone and higher ongrowth rate. In this study we examined the effect of alkali and heat treatments on titanium rod in rabbit femur intramedurally model, in consideration of cementless hip stem. The implant had a 5mm in diameter and 25 mm in length. The implants were and half of them were immersed in 5 mol/L sodium hydroxide solution and heated at 600 åé for one hour (AH implant), and the other half were untreated (CL implant). The implants were implanted into the distal femur of the rabbits, AH implant into left femur and CL implants into right. The bone-implant interfaces were evaluated at 3, 6, and 12 weeks after implantations.

Pull-out tests showed that AH implants significantly higher bonding strength to bone than CL implants at each week after operations. At 12 weeks mean pull-out load of AH implants was 411.7 N and that of CL implants 72.2 N. As postoperative time elapsed, histological examination revealed that new bone form on the surface of the both types of the implants, but significantly more bone contacted directly on the surface of AH implants. At 12 weeks AH implant was covered by the newly formed bone about 56% of the whole surface of the implants and CL implants was about 19%.

In conclusion, alkali- and heat-treated titanium offers strong bone-bonding and high affinity to bone instead of conventional mechanical interlocking mechanism. Alkali and heat treatments on titanium may be applicable to the surface treatment for cementless joint replacement implant.

The use of a composite osteochondral device for simulating partial hemiarthroplasty was examined. The device was composed of a polyvinyl alcohol hydrogel and a titanium fibre mesh, acting as artificial cartilage and as porous artificial bone, respectively. The titanium fibre mesh was designed to act as an interface material, allowing firm attachment to both the polyvinyl alcohol gel (through injection moulding) and the femoral joint surface (through bony ingrowth). We implanted 22 of these devices into canine femoral heads. Histological findings from the acetabular cartilage and synovial membrane, as well as the attachment of the prosthesis to bone, were examined up until one year after operation.

No marked pathological changes were found and firm attachment of the device to the underlying bone was confirmed. The main potential application for this device is for partial surface replacement of the femoral head after osteonecrosis. Other applications could include articular resurfacing and the replacement of intervertebral discs.