Posterior lumbar interbody fusion (PLIF) is indicated for many patients with pain and/or instability of the lumbar spine. We performed 36 PLIF procedures using the patient’s lumbar spinous process and laminae, which were inserted as a bone graft between two vertebral bodies without using a cage. The mean lumbar lordosis and mean disc height to vertebral body ratio were restored and preserved after surgery. There were no serious complications.

These results suggest that this procedure is safe and effective.

Purpose: The current clinical treatment protocol for bone healing applies super-physiological dose of rhBMP7. Unfortunately, it may result in adverse side effects. Some studies have demonstrated a dose-dependent osteogenic differentiation using rodent bone marrow derived stem cells (BMSCs). However, the dose effect of BMP7 on osteogenic differentiation of normal human BMSCs is largely unknown. In the present study, we investigated in vitro osteogenic differentiation of hBMSCs with a gradient concentration of rhBMP7. The interaction between rhBMP7 and osteogenic differentiation medium (ODM) was also examined.

Method: The primary BMSCs from human bone marrow were cultured and maintained in MSC growth medium (MGM). Six study groups were designed: MGM only, MGM with rhBMP7 of 0.1ug/ml, ODM only, and ODM with 3 concentration of rhBMP7 of 0.01μg/ml, 0.1μg/ml, and 1.0μg/ml, respectively. Alkaline phosphatase level (ALP) at day 17 and cumulative calcium deposit at both day 17 and day 35 were examined. mRNA expression level of osteogenic markers including osteocalcin (OC), osteopontin (OPN) and ALP were quantified using real-time RT-PCR at day 17.

Results: ALP activity at day17 did not increase in MGM with or without 0.1μg/ml of rhBMP7, ODM alone and ODM with 0.01μg/ml of rhBMP7. ALP activity was much higher with 0.1μg/ml of rhBMP7 plus ODM (0.22±0.02IU) than that in MGM with 0.1μg/ml of rhBMP7 (0.01±0.01IU, P< 0.05).

Conclusion: Our study demonstrated that rhBMP7 induced osteogenic differentiation of hBMSCs in a dose-dependent manner in the presence of ODM and the minimal dose for inducing in vitro osteoblastic differentiation was 0.1ug/ml of rhBMP7 under synergistic effect of ODM. The results of this study provide some insights into further investigation of synergy of rhBMP7 with other molecules. The types and amounts of simple molecules could significantly reduce therapeutic dose of rhBMP7 and achieve equivalent or better outcomes in clinical application warrant further investigation.

Purpose: The osteogenic effects of BMPs on mesenchymal stem cells (MSCs) are less profound in human as compared to rodent. The mechanism for this phenomenon is unclear. This study evaluated the effects of macrophages on proliferation and BMP-2 induced osteogenic differentiation of human MSCs.

Method: MSCs were isolated from human bone marrow. Human monocytes THP-1 (human acute monocytic leukemia cell line) were induced into macrophages by phorbol myristate acetate. The conditioned media (CM) from monocytes and macrophages were collected separately. After treated with CM from monocytes or macrophages for 5 and 7 days, the proliferation rate of human MSCs was determined by WST-8 assay. A group without CM served as control. Pretreated human MSCs were then induced towards osteogenic differentiation by osteoinductive medium supplemented with 0.1ug/ml BMP-2. Expression levels of osteogenic markers were determined by real-time quantitative PCR. Alkaline phosphatase (ALP) activity and mineral deposition were assessed by p-NPP colorimetric kinetic assay and calcium assay, respectively.

Results: The number of MSCs was significantly decreased in the group with macrophage CM at both 5 and 7 days (both p< 0.001) as compared with control group, but not in the group with monocytes CM. Expression levels of ALP and bone sialoprotein 2 in the macrophage CM group were significantly lower than those in the control group (p=0.003 and p< 0.001, respectively). ALP activity was also significantly lower in the group with macrophage CM than control group (p< 0.001). Although the expression levels of osteocalcin and RUNX2 as well as calcium deposition in the macrophage CM group were reduced, they did not reach statistical significance.

Conclusion: Macrophages suppressed the proliferation of MSCs and inhibited BMP-2 induced osteogenic differentiation of human MSCs. In addition to known BMP antagonists, macrophages might be another important factor in suppressing the osteogenic effect of BMP-2 on human MSCs.

We evaluated the long-term outcome of patients with an osteosarcoma who had undergone prior manipulative therapy, a popular treatment in Asia, and investigated its effects on several prognostic factors. Of the 134 patients in this study, 70 (52%) patients had manipulative therapy and 64 (48%) did not. The age, location, and size of tumour were not significantly different between the groups. The five-year overall survival rate was 58% and 92% in the groups with and without manipulative therapy (p = 0.004). Both the primary and overall rates of lung metastasis were significantly higher in the manipulative group (primary: 32% vs 3%, p = 0.003; overall lung metastasis rate: 51.4% vs 18.8%, p < 0.001). Patients who had manipulative therapy had higher local recurrence rates in comparison to patients who did not (29% vs 6%, p = 0.011). The prognosis for patients with osteosarcoma who had manipulative therapy was significantly poorer than those who had not. Manipulative therapy was an independent factor for survival.

This form of therapy may serve as a mechanism to accelerate the spread of tumour cells, and therefore must be avoided in order to improve the outcome for patients with an osteosarcoma.

To clarify the pathomechanisms of discogenic low back pain, the sympathetic afferent discharge originating from the L5-L6 disc via the L2 root were investigated neurophysiologically in 31 Lewis rats. Sympathetic afferent units were recorded from the L2 root connected to the lumbar sympathetic trunk by rami communicantes. The L5-L6 discs were mechanically probed, stimulated electrically to evoke action potentials and, finally, treated with chemicals to produce an inflammatory reaction. We could not obtain a response from any units in the L5-L6 discs using mechanical stimulation, but with electrical stimulation we identified 42 units consisting mostly of A-delta fibres. In some experiments a response to mechanical probing of the L5-L6 disc was recognised after producing an inflammatory reaction. This study suggests that mechanical stimulation of the lumbar discs may not always produce pain, whereas inflammatory changes may cause the disc to become sensitive to mechanical stimuli, resulting in nociceptive information being transmitted as discogenic low back pain to the spinal cord through the lumbar sympathetic trunk. This may partly explain the variation in human symptoms of degenerate discs.

Aims: The purpose of this study was to quantify the amount of cell viability and cartilaginous damage present in non-reparable human osteoarticular fragments removed at the time of acetabular fracture surgery. Material and Methods: The cases of 6 patients with comminuted fractures of the acetabulum were prospectively analyzed. Average age was 39 years, and none of them had evidence of preexisting hip pathology. Loose small osteoarticular fragments that were not reparable were microscopically analyzed to assess in-situ cell viability. Observations were divided into (i) depth of chondrocyte death from the articular surface, and (ii) structural matrix damage and cell death under regular histology. The depth of cell death was classiþed as mild between 1 and 15%, moderate from 15 to 30%, severe from 31 to 60% and total from 61 to 100%. Results: Five of the patients were classiþed as having only mild amount of chondrocyte death and one specimen had a moderate amount of chondrocyte death. The articular surface damage was mainly located on the superþcial zone of the cartilage. Discussion and conclusion: Most of the chondrocytes on small osteochondral fragments removed from displaced intraarticular acetabular fractures were still viable after having received a substantial amount of trauma.

We retrospectively reviewed 45 hip arthroplasties which were performed over a period of 20 years in 38 patients with cirrhosis of the liver. There was a high perioperative 30-day complication rate (26.7%). Advanced cirrhosis was associated with a higher risk of complications (p = 0.004) as also was increased age, a high level of creatinine, a low level of albumin, a low platelet count, ascites, encephalopathy and an increased operative blood loss. The survival of the prosthesis at five years was 77.8% and infection was a major cause of failure.

In view of the high rate of early complications and the limited longevity of the prosthesis, surgeons who perform hip arthroplasty on such patients should counsel them appropriately preoperatively.

Free radicals, such as reactive oxygen species (ROS) which are released abruptly after deflation of an ischaemic tourniquet, cause reperfusion injuries. Ischaemic precondition (IPC), however, can reduce the injury. In clinical practice, the sequential application and release of tourniquets is often used in bilateral total knee replacement (TKR) to obtain a clearer operative field, but the effects on the production of free radicals and lipid peroxidation have not been studied.

In this study, we have observed the production of free radicals and the subsequent lipid peroxidation in bilateral TKR with sequential application of a tourniquet to examine the effect of IPC. Patients undergoing elective TKR under intrathecal anaesthesia were studied. Blood samples were obtained after spinal anaesthesia, one minute before and five and 20 minutes after release of each tourniquet. We used the lucigenin chemiluminescence analysis and the phosphatidylcholine hydroperoxide (PCOOH) assay to measure the production of ROS and lipid peroxidation.

Our results showed that production of ROS significantly increased at five and 20 minutes after release of the first tourniquet and at five minutes after release of the second tourniquet, but returned to normal at 20 minutes after the second reperfusion. The peak production of ROS was at 20 minutes after the first reperfusion; lipid peroxidation did not change significantly.

We conclude that in spite of significant production of ROS after the release of tourniquet, the IPC phenomenon occurs during bilateral TKR with sequential application of a tourniquet.

Between March 1990 and May 1991 we performed 85 primary total hip replacements in 74 patients using the Landos Atoll hydroxyapatite (HA)-coated cup and the Corail HA-coated stem. The patients were followed up for a mean of ten years. Of the 85 cups, 26 (31%) have already been revised and a further six are radiologically unstable and awaiting revision. Two femoral stems have been revised for infection without loosening.

The retrieved acetabular cups were studied by SEM and image-processing techniques to quantify the amount of residual HA on the cup. This was correlated with the clinical variables and modes of failure. The residual HA (as a percentage of the surface) on the loose cups correlated negatively with the duration of implantation (r = −0.732, p < 0.001). Six cups were stable at revision and had more residual HA coating than those which were loose (p < 0.01).

The rate of failure of the Landos Atoll HA-coated, smooth hemispherical cup with screw fixation is unacceptably high. Resorption of the HA coating is markedly increased in loose cups compared with stable cups. HA coating cannot substitute for stable mechanical fixation.

We have performed a prospective single-blinded randomised study to evaluate the role of antibiotic-impregnated cement in the prevention of deep infection at primary total knee arthroplasty (TKA) in patients with diabetes mellitus. We studied prospectively 78 arthroplasties performed for osteoarthritis in such patients. They were randomly separated into two groups. In group 1 (41 knees), cefuroxime-impregnated cement was used while in group 2 (37 knees) cefuroxime was not added to the cement. The preoperative, intraoperative and postoperative management was the same for both groups. The mean follow-up was 50 months (26 to 88).

There were no cases of deep infection in group 1, but five (13.5%) occurred in group 2 (p = 0.021). We conclude that cefuroxime-impregnated cement is effective in the prevention of deep infection at primary TKA in patients with diabetes mellitus.