Soft Tissue Tension in Cruciate-Retaining and Posterior-Stabilized Total Knee Arthroplasty

Using a tensor for total knee arthroplasty (TKA) designed to facilitate soft tissue balance measurements with a reduced patellofemoral joint, we intraoperatively compared the soft tissue tension of cruciate-retaining (CR) and posterior-stabilized (PS) TKAs performed at 0°, 10°, 45°, 90°, and 135° of flexion, with the patella both everted and reduced in 40 osteoarthritic patients. Although balance of soft tissue tension with a reduced patella of PS TKA slightly increased in varus from extension to flexion, these values slightly decreased for CR TKA from extension to flexion. Accordingly, we conclude that soft tissue tension patterns differ between everted and reduced patellae, as well as between PS and CR TKA.     

The effects of arginine and selective inducible nitric oxide synthase inhibitor on pathophysiology of sepsis in a CLP model

BACKGROUND: Sepsis is an arginine-deficient state and is associated with overproduction of nitric oxide (NO) by inducible nitric oxide synthase (iNOS). It has been indicated that low plasma levels of arginine are related to high mortality rates in sepsis. Arginine, however, is also known to be a precursor of NO. Therefore, administration of arginine in septic patients remains controversial. We examined the effects of co-administration of arginine and aminoguanidine, a selective iNOS inhibitor, on sepsis, using rat models. METHOD: Sepsis was induced in rats by cecal ligation and puncture (CLP). Effects of separate and combined administration of arginine and aminoguanidine were investigated by comparing plasma levels of arginine, expressions of heme oxygenase (HO)-1 and HO-2 in liver and lung, and nitrite + nitrate (NOx) excretion in urine, as well as neuroendocrine responses in urine in the early phase of sepsis. Seven-day survival rates were also examined. RESULTS: A combination of arginine and aminoguanidine recovered the plasma level of arginine at 6 h post-CLP, decreased expression of HO-1 in liver and lung at 24 h post-CLP, decreased urinary excretion of epinephrine, norepinephrine, dopamine, and 17-hydroxycorticosteroid in the first 24 h post-CLP, and increased 7-d survival. CONCLUSION: It is demonstrated that administration of arginine together with the selective iNOS inhibitor in the early phase of sepsis restores plasma arginine, reduces oxidative stress by probably maintaining NO derived from constitutive NOS, and attenuates neuroendocrine stress responses. This co-administration may be a beneficial treatment approach against sepsis.     

New parameter of flexion after posterior stabilized total knee arthroplasty: posterior condylar offset ratio on X-ray photographs

In cruciate-retaining (CR) type TKA, the increase in posterior condylar offset (PCO) is considered to be correlated to flexion angle acquired postoperatively according to the article reported by Bellemans (J Bone Joint Surg Br 84:50–53, 2002). However, the significance of PCO seems to differ according to the size of joints. We therefore have defined a new parameter of posterior condylar offset ratio (PCOR) on the lateral view of plain X-ray photographs and studied the relationship between PCOR and postoperative flexion status in posterior-stabilized (PS) type TKA. Flexion status includes two parameters, such as postoperative flexion angle (FA) and flexion achievement rate (AR). The subjects of this study were 160 knees (16 males and 144 females, average 75 years.) with PS type TKA for osteoarthritic knees between 1999 and 2003 at our institution, more than at least 1 year postoperative follow-up. In the study of FA, patients with FA of less than 100° were divided into Group L (n = 28), patients with FA of 130° and greater were divided into Group H (n = 58). In the study of AR, patients with AR of less than 100% were divided into Group P (n = 46), patients with AR of 120% and greater were divided into Group G (n = 22). PCOR was statistically compared in each group, respectively. In FA, PCOR in Group L (0.385) was significantly lower (P = 0.027) than that in Group H (0.428). In AR, PCOR in Group P (0.376) was significantly lower (P = 0.0018) than that in Group G (0.456). We have concluded, though there are many factors influencing the range of movement after TKA, our newly defined PCOR could possibly serve as a parameter of postoperative flexion status of PS type TKA on plain X-ray photographs. No benefits or funds were received in support of the study.     

Comparative biomechanical analysis of an improved novel pedicle screw with sheath and bone cement

STUDY DESIGN: A human cadaveric biomechanical study of fixation strength of an improved novel pedicle screw (NPS) with cement and a conventional screw. OBJECTIVE: To clarify whether the NPS has adequate fixation strength without leakage in vertebrae with low bone quality. SUMMARY OF BACKGROUND DATA: The fixation strength of pedicle screws decreases in frail spines of elderly osteoporotic patients. Augmentation of screw fixation with bone cement must be balanced against increased difficulty of screw removal and risk of cement leakage. We developed the NPS consisting of an internal screw and an outer sheath to mitigate the disadvantages of cement augmentation. METHODS: The T12 and L1 vertebrae obtained from 18 formalin preserved cadavers (11 males and 7 females; mean age, 82.7 y) were used. The mean bone mineral density was 0.39 +/- 0.14 g/cm2. The NPS was inserted into one pedicle of each vertebra and the control screw, a Compact CD2 screw, was inserted into the contralateral pedicle. Both screws were 6mm in diameter and 40 mm in length. Pull-out tests were performed at a crosshead speed of 10 mm/min. Cyclic loading tests were performed with a maximum 250 N load at 2 Hz until 30,000 cycles. RESULTS: Cement leakage did not occur in any of the specimens tested. The mean maximum force at pull-out was 760 +/- 344 N for the NPS and 346 +/- 172N for the control screw (P < 0.01). Loosening of 50% of the screws was observed after 17,000 cycles of the NPS and after 30 cycles of the control screw. The hazard ratio of loosening was 19.6 (95% confidence interval 19.3-19.9) (P < 0.001). CONCLUSIONS: The NPS showed a significantly higher mechanical strength than the control screw in both pull-out tests and cyclic loading tests. The NPS showed more than adequate strength without cement leakage.     

Lumbar foraminal stenosis causes leg pain at rest

Purpose

Lumbar intra-spinal canal stenosis is characterized by leg pain that intensifies during walking and intermittent claudication, while leg pain at rest is a characteristic neurological symptom of lumbar disc herniation. Until now, a correlation between leg pain at rest and symptomatic foraminal stenosis has not been reported. This is a prospective and comparative study of unilateral leg pain from L5 nerve root compression due to spinal canal stenosis to determine clinical characteristics of lumbar foraminal stenosis.

Methods

Clinical and neurological findings were compared among 38 patients receiving L5–S1 transforaminal lumbar interbody fusion for L5–S1 foraminal stenosis (FS group) and 60 patients receiving L4–5 decompression or/and fusion for L4–5 intra-spinal canal stenosis (CS group).

Results

The only significant difference between the FS and CS groups in demographic clinical data was leg pain at rest. The prevalence of leg pain was significantly higher in the FS group compared to the CS group (76 vs. 35 %). The visual analogue scale for leg pain at rest was also significantly higher in the FS group than in the CS group (6.6 ± 3.1 vs. 1.3 ± 1.9).

Conclusions

Leg pain at rest is characteristic of L5–S1 foraminal stenosis.     

Inhaled tiotropium to prevent postoperative cardiopulmonary complications in patients with newly diagnosed chronic obstructive pulmonary disease requiring lung cancer surgery

Purpose

A new diagnosis of chronic obstructive pulmonary disease is often made during the evaluation of patients requiring lung cancer surgery. The objective of the present study was to evaluate the clinical effects of inhaled tiotropium on the postoperative cardiopulmonary complications in patients with untreated chronic obstructive pulmonary disease requiring lung cancer surgery.

Methods

A retrospective study involving 104 consecutive patients with moderate to severe chronic obstructive pulmonary disease who underwent a lobectomy for lung cancer at two specialized thoracic centers between April 2008 and October 2011 was performed. The results were compared between patients who did and did not receive inhaled tiotropium during the perioperative period. The primary endpoint was the incidence of postoperative cardiopulmonary complications. The postoperative white blood cell counts and C-reactive protein levels as biomarkers of inflammation were also examined.

Results

The incidence of postoperative cardiopulmonary complications was significantly lower in the tiotropium group than in the control group (18 vs. 48 %, P = 0.001). Patients in the tiotropium group also showed significantly lower white blood cell counts and C-reactive protein levels postoperatively.

Conclusions

Inhaled tiotropium treatment during the perioperative period had a prophylactic effect on postoperative cardiopulmonary complications in patients with newly diagnosed chronic obstructive pulmonary disease requiring lung cancer surgery.     

Early and frequent development of ocular hypertension in children with nephrotic syndrome

Background

Prednisolone, the first-line treatment for children with nephrotic syndrome, causes severe side effects. One of these side effects is ocular hypertension, which can result in severe and permanent visual disturbance. However, the exact prevalence, severity and timing of development of ocular hypertension have yet to be fully explored in this pediatric patient group.

Methods

In this retrospective cohort study, children with nephrotic syndrome treated with prednisolone for their first episode were analyzed. Intraocular pressure was screened with an iCare® tonometer and confirmed with Goldmann applanation tonometry before the initiation of prednisolone treatment and at 1 and 4 weeks thereafter.

Results

A total of 26 children with nephrotic syndrome were included in this study, of whom eight (30.8 %) required treatment with eye drops for ocular hypertension. The median time interval between the diagnosis of ocular hypertension and start of treatment was 9 (range 5–31) days. At relapse of nephrotic syndrome, all children who had undergone treatment for ocular hypertension in their first episode again required treatment for ocular hypertension.

Conclusions

Routine ophthalmologic examination should be conducted from the early phase after the start of prednisolone treatment. In addition, children with episodes of ocular hypertension may be at greater risk of its reappearance with relapse of the nephrotic syndrome.     

Voluntary ambulation using voluntary upper limb muscle activity and Hybrid Assistive Limb® (HAL®) in a patient with complete paraplegia due to chronic spinal cord injury: A case report

Context: We sought to describe our experience with the Hybrid Assistive Limb® (HAL®) for active knee extension and voluntary ambulation with remaining muscle activity in a patient with complete paraplegia after spinal cord injury.

Findings: A 30-year-old man with complete paraplegia used the HAL® for 1 month (10 sessions) using his remaining muscle activity, including hip flexor and upper limb activity. Electromyography was used to evaluate muscle activity of the gluteus maximus, tensor fascia lata, quadriceps femoris, and hamstring muscles in synchronization with the Vicon motion capture system. A HAL® session included a knee extension session with the hip flexor and voluntary gait with upper limb activity. After using the HAL® for one month, the patient’s manual muscle hip flexor scores improved from 1/5 to 2/5 for the right and from 2/5 to 3/5 for the left knee, and from 0/5 to 1/5 for the extension of both knees.

Conclusion/clinical relevance: Knee extension sessions with HAL®, and hip flexor and upper-limb-triggered HAL® ambulation seem a safe and feasible option in a patient with complete paraplegia due to spinal cord injury.     

The overexpression of SIRT1 inhibited osteoarthritic gene expression changes induced by interleukin‐1β in human chondrocytes

In this study, we examined the effects of overexpression of SIRT1 on IL‐1β‐induced gene expression changes in human chondrocytes to explore a protective role of SIRT1 in human chondrocytes. SIRT1 was overexpressed in human chondrocytes by expression plasmid under stimulation with IL‐1β. SIRT1 was also inhibited by siRNA under stimulation with IL‐1β. Gene expression changes were examined by real‐time PCR. The interaction of SIRT1 and p65 (NF‐κB) were examined by Western blotting. SIRT1, MMP‐13, and ADAMTS‐5 expressions in human cartilage were examined by immunohistochemistry. IL‐1β stimulation significantly up‐regulated MMP‐1, 2, 9, and 13 and ADAMTS‐5. Overexpression of SIRT1 significantly inhibited the up‐regulation of those genes caused by IL‐1β while the inhibition of SIRT1 further increased them. In addition, the overexpression of SIRT1 markedly reduced the IL‐1β‐induced acetylation of p65. SIRT1 expression was clearly detected in the non‐OA cartilage while MMP‐13 and ADAMTS‐5 were undetectable. In contrast, in the OA cartilage, SIRT1 expression was decreased while MMP‐13 and ADAMTS‐5 were increased. Our observations suggested that SIRT1 can play a protective role by suppressing IL‐1β‐induced expressions of cartilage‐degrading enzymes partially through the modulation of the NF‐κB pathway. SIRT1 overexpression might be a new therapeutic approach for OA. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 531–537, 2013