Purpose

Reproducing a functional flexion-extension axis (FEA) of the femur is key to achieving successful collateral ligament balance and joint line in total knee arthroplasty (TKA). This study assessed the feasibility of cylindrical axis (CA)-reference bone-cut and articular surface-reference bone-cut to reproduce FEA in Japanese osteoarthritis patients.

Objectives

Proximal tibial fracture is one of the most common postoperative complications of unilateral knee arthroplasty (UKA). The objective of the present study is to investigate the risk factors of these fractures, occurred after UKA in our facility.

Background

Unexplained pain is one of the most common complications after Oxford UKAs. We have retrospectively reviewed the patients who underwent Oxford UKAs and investigated those patients with prolonged pain and found that many of these patients had strong tenderness over the Hunter canal and they were well treated with Hunter canal block or administration of Pregabalin. We have checked the details of these prolonged pain and key to the treatment will be discussed.

Introduction

When total knee arthroplasty (TKA) or unicompartmental knee arthroplasty (UKA) was indicated for the patient, it is important to perform the exact preoperative planning. Conventionally we created the plan based on the Xp films and transparent acetate sheets. Recntly, the digital radiographs and templating systems were introduced in hospitals and utilized for the preoperative planning. The purpose of this study is to investigate the accuracy of the digital templating by comparing the size of the implants between those chosen by the planning and those actually selected during the operation.

Summary Statement

In this study, we observed that MR16-1, an interleukin-6 inhibitor, recovered phosphatidylcholine containing docosahexaenoic acid at the injury site after spinal cord injury in mice model by using imaging mass spectrometry.

Introduction

The purpose of this study was to examine if Sugioka's transtrochanteric rotational osteotomy (TRO) of the femoral head could be a valid option in treating idiopathic osteonecrosis of the femoral head.

Aim: To ameliorate surgical strategy of disabled rheumatoid hip joints, perioperative status and clinical features of the patients undergoing total hip arthroplasty (THA) were retrospectively evaluated.

Materials and Methods: 150 joints of 106 patients were studied (male/female rate; 1:6, mean age; 60 years and duration of the disease; 15 years). All patients received cemented THA (mean follow-up period; 8 years). Mode of bone defect with acetabular reconstruction type, femoral bone quality, survivorship, steroid use and complications were surveyed.

Results: In preoperative status, proturusio acetabuli was found in 37% with type I; 54%, II; 34% and III; 12% by Sotelo-Garza classification. Superior bone defect was recognized in 56%, collapse and/or defect of femoral head in 19%, and geode formation in 0.2%. Femoral medullar canal was classified as type A; 1%, type B; 53% and type C; 46% by Dorr classification. The presence of fracture before surgery was 5%. Anatomical reconstruction was achieved in all cases including application of 42% bone grafting (autogenous alone; 51%, application of artificial substitute; 39% and of cross-plating system; 10%). Acetabular revision rate due to aseptic loosening (%/years) was improved by graft methods (whole series; 5/8, any grafting; 6/8, autogenous alone; 8/8, artificial substitute; 4/8 and cross-plate system; 0/4). Revision rate for any reasons was 9% (aseptic acetabulum 5%, aseptic femur 5%, dislocation 2% and infection 1%). Dislocation (11%), infection (3%) and severe thrombotic events (1%) were experienced. Steroid use was found in 73%, associated with increased risk of protrusio acetabuli, superior bone defect with protrusio acetabuli and fractures.

Discussion and Conclusion: The study indicated that steroidal medication significantly related to the perioperative status of bone defects and perioperative fractures of rheumatoid patients undergoing THA. Improved ace-tabular procedures could promise better survivorship of the implant.

Revision of the femur component in total hip arthroplasty using impaction bone grafting (IBG) was performed in 140 hips of 136 patients in our hospital. The mean age of the patients at the time of the femoral component revision was 72 years. The median of follow-up time was 80 months. 140 hips were operated with use of YU stem (Yamagata university stem, collared, not polished)104, Exeter stem 2, CPT 2, Restration 5, and others 27.

The length of the stem was a regular stem 114, a long stem 26. The complications related to the revised hip consist of infection 5, dislocation 8, DVT9, fracture during operation 11. Four stems were revised due to infection and two due to loosening.

YU stem is made of titanium alloy with collar, the surface of that stem is not polished and Ra is 0.27 μm. We started to apply IBG in 1994, there were no IBG instrument set and system available such as Exeter, CPT in Japan, so we had used YU stem. However, the result with YU stem was preferable and the implant was stable. Thus, we have been using YU stem. In the process, there have been a number of improvements in IBG instrument and system since we started using them. At first, all medullar cavity is filled with grafted bone up to proximal entry with moderate impaction. Along with guide pin, new medullar canal is made by drilling and insert stem tamper into the space to tighten the layer of impaction, then cement fixation of the stem is performed. This method made the operative time short and operative technique easy.

There are several advantages of IBG technique we used. In revision THA, we can revise the stem with the same length of previous one again and exchange also a long stem to a regular length stem. In addition, the system make it possible to re-construct the case of distal medullar canal excessively filled with bone cement below stem, by digging about around 2 cm distally without need to remove all the cement. Severe bone atrophy and fragile of femur is also reconstructed by IBG.

Impaction bone grafting technique with modified system has great merit to recover bone stock and to obtain implant stability after femoral reconstruction of revision surgery.

Visualization of the femoral medullar canal is troublesome in revision surgery. To obtain better visual field of the canal and assist cement extraction and following reconstructive procedures, flexible endoscope was applied in femoral revision. Mean age and time to revision of fifteen cemented totally replaced hips were 69.3 (42–83) and 14.9 (3–25) years, respectively. Preoperative status of the revision regarding type of stem loosening was classified as possible in four cases, probable in two, and definite in five classified by Harris et al. No marked finding of loosening was in four. That of bone defect was type I in four cases, Type II in three, and Type III in three by Gustilo. Five cases showed no marked loss of the defect. Extraction of cement mantle was performed under flexible endoscopic inspection. Impaction bone grafting was performed in eight cases. Time for cement removal in association with type of loosening and bone defect were evaluated as well as analysis of periprosthetic complications.

Retained cement mantle was extractable in all cases under good exposure and with maintenance of efficient working space. Interfacial granulation and fibrous tissues between bone and cement were easily removed. Endoscopic time for cement removal was 41.7 ± 10.3 minutes in average. It was 51.8 ± 6.2 minutes in no loosening. 41.3 ± 11.1 minutes in possible loosening, 38.5 ± 9.2 minutes in probable loosening, and 35.4 ± 8.3 minutes in definite loosening, which depended on the status of fixation between bone and cement. Type of bone defect also influenced the time. It was 52.4 ± 5.6 minutes in the cases of no marked bone loss, 43.8 ± 3.5 minutes in Gustilo type I, 28.3 ± 3.5 minutes in Type II, and 34.7 ± 2.5 minutes in Type III. The procedure was effective to prepare suitable bone bed for reconstruction, which allowed proper stem settlement and facilitated recovery of bone stock in the cases of impaction bone grafting. Intra-operative blood loss was 377 ml (212 – 1430) and total amount of blood loss including post surgical drainage was 593 ml (316 – 1680). Type of loosening and bone defect did not affect both whole and intra-operative bleeding volume. However, three occult fractures happened, in which two revealed minor cement leakage and one required additional osteosynthesis with extensive approach.

The data indicated that flexible medullo-endoscope could provide good visual field with maintenance of working space, potentially contributing to less invasive femoral revision surgery, if it would be combined with refined device for cement extraction to improve accuracy of the procedure.

Purpose: The inflammatory response around herniated tissue in the epidural space is believed to play a major role in the spontaneous regression of herniated lumbar disc. Numerous macrophages invade the herniated tissue along with newly formed blood vessels which influence oxygen gradient. Inflammatory cytokines such as interleukin-1 are produced by macrophages. These chemical mediators could stimulate disc cells to produce proteases such as MMPs which degrade the intervertebral disc matrix and could hence influence regression of the herniation. Here we have examined the influence of IL-1β and oxygen tension on proteoglycan turnover using a three-dimensional disc-cell culture system.

Methods: Cells were isolated from the nucleus pulposus of 18–24 month bovine caudal discs by enzyme digestion. They were initially cultured for 14 days in alginate beads in DMEM containing 6% FBS at 4.10⁶ cells/ml under 21% oxygen to accumulate matrix. They were then cultured for 6 days under 0% or 21% oxygen and with or without IL-1β. Glycosaminoglycan (GAG) accumulation (as a measure of proteoglycan content) was measured using a DMB assay. Lactate and glucose production were measured using a standard enzymatic method. Rates of sulfated GAG synthesis was measured from rates of ³⁵S-sulfate accumulation. MMP activity was measured using coumarin fluorescent assay.

Results: The results showed that IL-1β had a significant effect on GAG accumulation and production and that its effect was dependent on oxygen tension. GAG production and sulfate incorporation rates decreased in the presence of IL-1β at high oxygen but low oxygen inhibited the effects of this cytokine. MMP activity increased with IL-1β under 21% oxygen, but not at low oxygen.

Conclusion: Exogenous IL-1β can activate MMP activity and digest the extracellular matrix of the disc but only at high oxygen tensions. Angiogenesis as well as inflammation is thus required for resorption of herniations.

Purpose: Proteoglycan loss is one of the first signs of disc degeneration. There is increasing interest in developing biological methods for its replacement both by in vivo repair and through tissue engineered constructs. Many factors influence the rate of proteoglycan accumulation. In this study, we examine how physiological levels of extracellular osmolality and oxygen tension influence proteoglycan accumulation in nucleus pulposus cells in a three-dimensional culture system.

Methods: Cells were isolated from the nucleus pulposus of 18–24 month bovine caudal discs. They were cultured for 6 days in alginate beads at 4 million cells/ml in DMEM containing 6% FBS under 0%, 5% and 21% O₂, Medium osmolality was altered by NaCl addition over the range 270–570 mOsm. Cell viability was determined by manual counting using trypan blue. Lactate production was measured enzymatically and glycosaminoglycan (GAG) accumulation was measured using a DMB assay.

Results: There was no difference in the cell viability. Lactate production decreased under hypo- (270 mOsm) after 6 days in culture. After 6 days GAG accumulation was maximal in beads cultured at 5% O₂ in 370 mOsm where GAG accumulation was 86.1% greater than at 21% O₂ and DMEM at standard Osmolarity (270 mOsm).

CONCLUSION: In our model the prevailing osmolality was a powerful regulator of GAG accumulation by cultured nucleus cells. In vivo prevailing osmolality is governed by GAG concentration. These results thus indicate GAG synthesis rates are regulated by GAG concentration, with implications both for the aetiology of degeneration and for tissue engineering.

A prospective randomized study was performed to evaluate the role of cold therapy in the postoperative treatment of total hip arthroplasty (THA). Forty consecutive patients underwent primary total hip arthroplasty for osteoarthritis. All components were not cemented. The patients were randomized: 20 were fitted with a cold therapy device for four days, and 20 were not. They were evaluated in terms of blood loss, creatine phosphokinase (CPK) level, C-reactive protein (CRP) level, and pain relief. No significant difference was found in the amount of postoperative wound drainage between the two groups of patients. The use of cold compressive dressing after THA was not associated with an increase in CPK and CRP level.

The pain score in the postoperative period of THA was significantly lower in the cold therapy group than in the control group. The results of this study support the potential benefit in pain reduction by use of the cold compressive device in the postoperative recovery of patients undergoing THA.

Polyethylene wear is the most important risk factor affecting the durability of total knee arthroplasty. We developed a new method of measuring wear of the tibial polyethylene insert in total knee arthroplasty (TKA) on standard standing radiographs.

Methods: We developed a new method of measuring the shortest distance between the femoral component and the tibial metal tray taking its 3-D position into consideration. The accuracy of the method was examined in 3 conditions. An in vitro examintion measured the thickness of the polyethylene on radiographs of a new PFC prosthesis set on a table. The radiographs were taken from various directions. An in vivo examination measured the polyethylene thickness on patient discharge radiographs of 78 knees. These measurements were compared with known thicknesses of the used inserts. In the third study, wear of the tibial polyethylene insert was measured retrospectively in a series of 84 PFC TKAs with follow-up of 2 to 10 years (6.6 years on average).

Results: The average measurement error was 0.05 mm (SD 0.09 mm) in the in vitro study and 0.14 mm (SD 0.17 mm) in the in vivo study using discharge radiographs. In the series of 84 PFC TKAs, impending failure occurred in 7 knees, 4 of which were revised. Radiographically measured wear of the tibial insert was significantly greater in these failed TKAs than in the other TKAs. The radiographic measurements were well correlated with 3-D measurements of 4 retrieved inserts.

Discussion: Although the radiographic measurement of the tibial insert in TKA was less accurate than that of the socket in THA, it is useful enough to identify TKAs at risk of failure. When the radiographic wear exceeded 1mm, there was a significantly increased probability of impending failure or need for revision.

By 1998, 10 patients had undergone 12 revision total knee arthroplasties at our institute. One patient died three weeks after surgery due to cerebral infarction, leaving 11 knees of nine patients for evaluation. Average follow-up was 4.8 years (1 to 9 years). All components were subjected to revision surgery in five knees, the tibial tray and insert in four knees, and only the insert in two knees. Patients were evaluated with clinical examinations, radiographs, and the Knee Society Clinical Rating System.

After revision surgery, the Knee Scores and ROMs were restored to almost the same level as just after the first TKA. Re-revision was performed on two patients, one 103 months and the other 82 months after revision TKA. In those two patients, huge bone loss of the proximal tibial canal was filled with cement without bone graft. The other patients, however whose tibial trays were fixed with cement on adequate grafted bone obtained good results.

The femoral components that were not treated with revision surgery despite small flaws or scratches due to wear and tear of the tibial insert did not cause marked wear of the new tibial insert.

Conclusion: Bone loss of the proximal tibial canal should be filled with bone graft, not with cement only. Femoral components with small flaws or scratches, and without other ploblems, need not to be treated with revision surgery.

The aim of the present investigation is to study the status of the blood-nerve barrier in the carpal tunnel syndrome and cubital tunnel syndrome using gadolinium enhanced MRI.

The subjects were 68 patients (92 hands) with idiopathic carpal tunnel syndrome and 21 patients (23 elbows) with cubital tunnel syndrome.

The MRI equipment used was a 0.3-T permanent magnet. Using the SE method, T1-weighted axial images were obtained. Then, we intravenously injected gadolinium for enhanced images. We studied the relationship between nerve enhancement and the symptoms of the patients.

Out of 92 hands with carpal tunnel syndrome, 74 hands (80%) showed enhancement of the median nerve. The patients had 58 hands classified as Grade I (sensory disturbance only) out of which 44 hands (76%) showed nerve enhancement , as did 25 out of 29 hands (86%) classified as Grade II (I + thenar muscle atrophy) and all 5 hands (100%) classified as Grade III (II + disturbance of opposition). Enhancement was more prominent in the patients with thenar muscle atrophy. All 23 elbows with cubital tunnel syndrome revealed enhancement of the ulnar nerve. Two elbows were categorized as grade I (sensory disturbance only), 12 as grade II (I + 1’st inter-osseus muscle atrophy), and 9 as grade III (II + claw finger deformity)

In general, capillaries exist inside the endoneurial spaces of peripheral nerves. Intraneural homeostasis is maintained by the perineurium as a diffusion barrier and by the blood-nerve barrier existing in the endothelium. MRI could demonstrate intraneural enhancement at the site of nerve entrapment where intraneural edema resulted from an increase in the vascular permeability of the endoneurium. We conclude that gadolinium-enhanced MR imaging can detect morphological and functional changes of peripheral nerve in patients with entrapment neuropathy.

Periprosthetic osteolysis has attracted attention as a cause of loosening after arthroplasty. The aim of the present study was to examine inflammatory cell localization and the occurrence of apoptosis in granulation tissue from patients who required revision arthroplasty due to loosening caused by osteolysis.

7 patients were studied comprising 3 patients who underwent FHR and 4 patients who underwent THR. Their mean age at the time of surgery was 63.6 years. The mean period from their previous operation to revision was 8.8 years.

Granulation tissue was collected from around the loosened implant fixed in 4% paraformaldehyde and embedded in paraffin. Sections were cut and were first stained with hematoxylin and eosin. Next, immunohistochemical studies were performed using the avidin-biotin complex method. CD45 was used as the primary antibody to detect T cells, and CD68 was used to detect macrophage-like cells. The activity of the macrophage-like cells was assessed with anti-I-NOS and anti-MMP-9.

Apoptosis was investigated using anti-single-stranded DNA (ssDNA). Using another granulation tissue was stored at −80%C, DNA was extracted, and the presence of DNA fragmentation was detected by agarose gel electrophoresis.

Vascularization and infiltration by a large number of inflammatory cells were seen along with large multinucleated osteoclas-like cells. Immunohistochemical studies revealed CD45-positive cells primarily around the blood vessels. The CD68-positive cells were mainly multinucleated cells. The multinucleated cells were i-NOS-positive in 4 patients, and were MMP-9-positive in 5 patients.

The nuclei of many of the multinucleated cells were positive for ssDNA. Agarose gel electrophoresis of DNA showed a marked ladder pattern at the 170 base pair region. This finding indicated DNA fragmentation or apoptosis.

Apoptotic cells were seen in granulation tissue harvested from around loosened implants suggesting that apoptosis may play a role in the pathophysiology of osteolysis.