Use of All-polyethylene Tibial Components in Unicompartmental Knee Arthroplasty Increases the Risk of Early Failure.

All-polyethylene (all-poly) tibial designs in primary total knee arthroplasty (TKA) have been reconsidered with excellent clinical outcomes, survivorship, and cost-effectiveness. However, whether all-poly tibial components provided comparable results to metal-backed modular components during unicompartmental knee arthroplasty (UKA) remains unclear. This study compared the clinical outcomes and prevalence of early failure between all-poly and metal-backed modular components in UKA. We retrospectively reviewed the records and radiographs of 101 consecutive UKAs. In total, 51 UKAs were performed using all-poly tibial components; 50 others used metal-backed modular components. Clinical and radiographic outcomes, adaptive bone remodeling assessed by radiographic bone density, and early failure prevalence rates were compared. Despite a lack of group differences in clinical and radiographic outcomes (p > 0.1 in all comparisons), adaptive bone remodeling at 2 years after surgery of all-poly UKAs was more progressive compared with metal-backed UKAs (1.2 in all-poly UKA group vs. 0.9 in metal-backed UKA group, p < 0.001). In addition, 6 of 51 all-poly UKAs failed within 2 years postoperatively, whereas no metal-backed UKAs failed (11% in all-poly UKA group vs. 0% in metal-backed UKA group, p = 0.027). All-poly tibial component use during UKA increased the risk of early failure, which may be due to a failure in tibial loading distribution.

Effect of nerve growth factor and its transforming tyrosine kinase protein and low-affinity nerve growth factor receptors on apoptosis of notochordal cells.

PURPOSE: The disappearance of notochordal cells by apoptosis is thought to be the starting point of intervertebral disc degeneration. The aim of this study was to determine the apoptotic pathway of notochordal cells as well as the anti-apoptotic potential of caspase inhibitors. METHODS: Rat notochordal cells were isolated, cultured, and placed in either 0 % (apoptosis-promoting condition) or 10 % (normal control) foetal bovine serum (FBS). We identified and quantified apoptotic cell deaths and caspase activities. In addition, we examined the cells for expression of nerve growth factor (NGF) and its two receptors--TrkA (survival signal) and p75 (apoptotic signal)--and downstream pathways. Finally, we analysed the degree of anti-apoptotic effects of caspase inhibitors on the cells. RESULTS: The apoptotic rate and expressions of caspase-8 (extrinsic pathway), -9 (intrinsic pathway), and -3 (common executioner) of notochordal cells were increased in 0 % FBS compared with those in 10 % FBS. Expressions of NGF, p75 receptor and JNK downstream pathways were also increased in 0 % FBS. In contrast, expressions of the TrkA receptor and Akt and MAPK downstream pathways were decreased in 0 % FBS. Pancaspase, capase-9 and capase-8 inhibitors significantly reduced apoptotic cell death. CONCLUSIONS: Our results suggest that notochordal cells undergo apoptosis through both the intrinsic and extrinsic pathways by activation of NGF, p75 receptor, and the JNK downstream pathway. We also found that apoptosis of notochordal cells can be attenuated by caspase inhibitors. Caspase inhibitors may play a therapeutic role in delaying the starting point of disc degeneration that is due to inappropriate or premature excessive apoptosis of notochordal cells.

Patellar tracking after total knee arthroplasty performed without lateral release.

There is limited clinical data on patellar maltracking in patients who have undergone total knee arthroplasty (TKA) without lateral release. We performed a retrospective review of 191 consecutive TKAs performed by one surgeon through the subvastus approach without lateral release from 2007 to 2008. Radiographic measurements were made using the preoperative and postoperative 2 years radiographs. Multivariate logistic regression analysis was performed to determine the risk factors for patellar maltracking after TKA performed without lateral release. TKA resulted in increases in the patellar tilt and displacement (P<0.05). The presence of preoperative patellar tilt and displacement were predictive of postoperative patellar tilt and displacement in patients who underwent TKA through the subvastus approach without lateral release (P<0.05).

The effects of applying adhesion prevention gel on the range of motion and pain after TKA.

A mixed solution of sodium hyaluronate and sodium carboxymethylcellulose (HA/CMC) has been shown to be effective for decreasing postoperative adhesions in various kinds of surgeries. We evaluated the clinical efficacy and safety of HA/CMC gel on the early postoperative range of motion and pain relief after total knee arthroplasty (TKA). Thirty one patients who underwent bilateral TKA as a single-stage procedure for primary osteoarthritis were included in the study. At the completion of surgery, among both knees, the HA/CMC gel was applied to one knee (the HA/CMC group) and HA/CMC gel was not applied to the other knee (the control group). The primary outcome measure was the early assessment of range of motion and the secondary outcome measures were the VAS pain scores and the number of complications in each group. Periarticular application of HA/CMC gel was safe without causing any wound problems or infection. However, local application of HA/CMC gel neither increased the range of motion nor reduced the pain during the early postoperative period of TKA.

Ankle deformity secondary to acquired fibular segmental defect in children.

BACKGROUND: The authors report the long-term effect of acquired pseudoarthrosis of the fibula on ankle development in children during skeletal growth, and the results of a long-term follow-up of Langenskiold's supramalleolar synostosis to correct an ankle deformity induced by an acquired fibular segmental defect in children. METHODS: Since 1980, 19 children with acquired pseudoarthrosis of the fibula were treated and followed up for an average of 11 years. Pseudoarthrosis was the result of a fibulectomy for tumor surgery, osteomyelitis of the fibula and traumatic segmental loss of the fibula in 10, 6, and 3 cases, respectively. Initially, a Langenskiold's operation (in 4 cases) and fusion of the lateral malleolus to the distal tibial epiphysis (in 1 case) were performed, whereas only skeletal growth was monitored in the other 14 cases. After a mean follow-up of 11 years, the valgus deformity and external tibial torsion of the ankle joint associated with proximal migration of the lateral malleolus needed to be treated with a supramallolar osteotomy in 12 cases (63%). These ankle deformities were evaluated using the serial radiographs and limb length scintigraphs. RESULTS: In all cases, early closure of the lateral part of the distal tibial physis, upward migration of the lateral malleolus, unstable valgus deformity and external tibial torsion of the ankle joint developed during a mean follow-up of 11 years (range, 5 to 21 years). The mean valgus deformity and external tibial torsion of the ankle at the final follow-up were 15.2 degrees (range, 5 degrees to 35 degrees) and 10 degrees (range, 5 degrees to 12 degrees), respectively. In 12 cases (12/19, 63%), a supramalleolar corrective osteotomy was performed but three children had a recurrence requiring an additional supramalleolar corrective osteotomy 2-4 times. CONCLUSIONS: A valgus deformity and external tibial torsion are inevitable after acquired pseudoarthrosis of the fibula in children. Both Langenskiöld supramalleolar synostosis to prevent these ankle deformities and supramalleolar corrective osteotomy to correct them in children are effective initially. However, both procedures cannot maintain the permanent ankle stability during skeletal maturity. Therefore any type of prophylactic surgery should be carried out before epiphyseal closure of the distal tibia occurs, but the possibility of a recurrence of the ankle deformities and the need for final corrective surgery after skeletal maturity should be considered.

The increased expression of matrix metalloproteinases associated with elastin degradation and fibrosis of the ligamentum flavum in patients with lumbar spinal stenosis.

BACKGROUND: One of the characteristics of spinal stenosis is elastin degradation and fibrosis of the extracellular matrix of the ligamentum flavum. However, there have been no investigations to determine which biochemical factors cause these histologic changes. So we performed the current study to investigate the hypothesis that matrix metalloproteinases (MMPs), which possess the ability to cause extracellular matrix remodeling, may play a role as a mediator for this malady in the ligamentum flavum. METHODS: The ligamentum flavum specimens were surgically obtained from thirty patients with spinal stenosis, as well as from 30 control patients with a disc herniation. The extents of ligamentum flavum elastin degradation and fibrosis were graded (grade 0-4) with performing hematoxylin-eosin staining and Masson's trichrome staining, respectively. The localization of MMP-2 (gelatinase), MMP-3 (stromelysin) and MMP-13 (collagenase) within the ligamentum flavum tissue was determined by immunohistochemistry. The expressions of the active forms of MMP-2, MMP-3 and MMP-13 were determined by western blot analysis, and the blots were quantified using an imaging densitometer. The histologic and biochemical results were compared between the two conditions. RESULTS: Elastin degradation and fibrosis of the ligamentum flavum were significantly more severe in the spinal stenosis samples than that in the disc herniation samples (3.14 +/- 0.50 vs. 0.55 +/- 0.60, p < 0.001; 3.10 +/- 0.57 vs. 0.76 +/- 0.52, p < 0.001, respectively). The expressions of the active form of MMPs were identified in all the ligamentum flavums of the spinal stenosis and disc herniation patients. The expressions of active MMP-2 and MMP-13 were significantly higher in the spinal stenosis samples than that in the disc herniation samples (both p < 0.05). The expression of active MMP-3 was slightly higher in the spinal stenosis samples than that in the disc herniation samples, but the difference was not statistically significant (p = 0.131). MMP-2, -3, and -13 were positively stained on the ligamentum flavum fibroblasts. CONCLUSIONS: The current results suggest that the increased expression of active MMPs by the ligamentum flavum fibroblasts might be related to the elastin degradation and fibrosis of the ligamentum flavum in the patients who suffer with lumbar spinal stenosis.

Autologous chondrocyte implantation for rheumatoid arthritis of the knee: a case report.

INTRODUCTION: Although pharmacologic treatment remains the mainstay for treating rheumatoid arthritis, there is an increasing need for a method that biologically regenerates arthritic knee lesions as patient longevity continually increases. CASE PRESENTATION: We treated rheumatoid arthritis of the right knee in a 35-year-old female Korean patient using autologous chondrocyte implantation. Twelve months after surgery, the patient could walk without pain. CONCLUSION: Autologous chondrocyte implantation appears to be effective for treating rheumatoid arthritis of the knee.

Treatment of osteonecrosis of the femoral head using autologous cultured osteoblasts: a case report.

INTRODUCTION: Osteonecrosis of the femoral head is a progressive disease that leads to femoral head collapse and osteoarthritis. Our goal in treating osteonecrosis is to preserve, not to replace, the femoral head. CASE PRESENTATION: We present the case of a patient with bilateral osteonecrosis of the femoral head treated with autologous cultured osteoblast injection. CONCLUSION: Although our experience is limited to one patient, autologous cultured osteoblast transplantation appears to be effective for treating the osteonecrosis of femoral head.