Characteristics of flexed knee gait and functional outcome of a patient who underwent knee reconstruction with a hingeless prosthesis for bone tumor resection: a case report with gait analysis and comparison with healthy subjects

We report on a patient after knee reconstruction for osteosarcoma in the distal femur using a hingeless prosthesis K-MAX KNEE system K-5 who walked without ipsilateral knee extension in the latter half of the stance phase (flexed knee gait). We evaluated the patient using three-dimensional gait analysis and isokinetic knee strength measurement, and compared the patient with five healthy subjects. The Musculoskeletal Tumor Society (MSTS) score was also used for evaluation. The patient kept his operated knee flexed during mid stance. The maximal ankle plantarflexion internal moment was lower on the ipsilateral side than on the contralateral side, and lower than in the healthy subjects. The negative ankle power during the stance phase was generally stronger on the ipsilateral side than on the contralateral side, and also in the healthy subjects. Unusual contralateral hip flexion occurred after the initial contact, indicating increased joint load on the ipsilateral ankle and the contralateral hip. The ratios of the peak knee extension/flexion torque were 0.7 on the ipsilateral side, 1.9 on the contralateral side, and 1.7 in the healthy subjects. The MSTS score of the patient was 23/30 (76.6%). Flexed knee gait might account for the reduction of ipsilateral hip flexion and ankle plantarflexion moment during the late stance phase. These results suggest the importance of focusing more on the ipsilateral ankle joint and the contralateral hip joint to maintain the function of the entire limb joints of the patients with flexed knee gait.

Characteristics of flexed knee gait and functional outcome of a patient who underwent knee reconstruction with a hingeless prosthesis for bone tumor resection: a case report with gait analysis and comparison with healthy subjects

We report on a patient after knee reconstruction for osteosarcoma in the distal femur using a hingeless prosthesis K-MAX KNEE system K-5 who walked without ipsilateral knee extension in the latter half of the stance phase (flexed knee gait). We evaluated the patient using three-dimensional gait analysis and isokinetic knee strength measurement, and compared the patient with five healthy subjects. The Musculoskeletal Tumor Society (MSTS) score was also used for evaluation. The patient kept his operated knee flexed during mid stance. The maximal ankle plantarflexion internal moment was lower on the ipsilateral side than on the contralateral side, and lower than in the healthy subjects. The negative ankle power during the stance phase was generally stronger on the ipsilateral side than on the contralateral side, and also in the healthy subjects. Unusual contralateral hip flexion occurred after the initial contact, indicating increased joint load on the ipsilateral ankle and the contralateral hip. The ratios of the peak knee extension/flexion torque were 0.7 on the ipsilateral side, 1.9 on the contralateral side, and 1.7 in the healthy subjects. The MSTS score of the patient was 23/30 (76.6%). Flexed knee gait might account for the reduction of ipsilateral hip flexion and ankle plantarflexion moment during the late stance phase. These results suggest the importance of focusing more on the ipsilateral ankle joint and the contralateral hip joint to maintain the function of the entire limb joints of the patients with flexed knee gait.

[Does aortic cusp repair influence the outcome of valve sparing aortic root replacement?]

BACKGROUND

Outcome of the patients who underwent aortic root replacement with valve sparing procedure concomitant with cusp repair was evaluated.

METHODS

Between October 1999 and April 2009, valve sparing aortic root replacement were performed in 62 patients. Isolated valve sparing procedure was performed in 38 patients (control) and concomitant cusp repair was performed in 24 patients (aortic valve plasty: AVP). Cusp prolapse was corrected by plication of Arantius body (n = 13), cusp perforations were closed by pericardial patch (n = 6) or reinforcement of free margin (n = 6).

RESULTS

No patient died during the hospital stay and no thromboembolic events occurred in the follow up. Pre-operative grade of aortic insufficiency was 3.0 +/- 0.9 in AVP group vs. 2.5 +/- 1.3 in control (NS). There was no significant difference between both groups regarding age, cardiac function and preoperative aortic root diameter. However, eccentric jet by preoperative transesophageal echocardiography (TEE) was more often in group AVP than in control (p<0.01). Five patients underwent reoperation because of recurrent aortic regurgitation (AR) or hemolysis. Postoperative AR grade were similar in both groups (0.9 +/- 0.5 vs 0.5 +/- 0.6). During follow up, the 5 year freedom from re-operation (aortic valve replacement: AVR) was 85.1+/- 8.2% in AVP and 94.0 +/- 4.1% in control (NS). 5-year-survival was 100% and 95.0 +/- 4.9% (NS), respectively.

CONCLUSIONS

Valve sparing aortic root replacement with concomitant cusp repair provided satisfactory midterm result.

[Intraoperative monitoring of the brain and spinal cord ischemia during thoracic aortic surgery]

Thoracic aortic surgery still involves a significant risk of neurological complications including stroke and paraplegia, associated with high morbidity and mortality. Intraoperative monitoring of the brain and the spinal cord ischemia, such as 4-channel cerebral In Vivo Optical Spectroscopy (INVOS) and myogenic transcranial motor evoked potentials (MEP), may enable us to prevent the devastating complications by prompt and proper intraoperative management. This review describes our standard methods for these procedures during thoracic aortic surgery.

[Perioperative management in cardiovascular emergency surgery]

Perioperative management in emergency cardiac operation is challenging because general condition of the patient is often poor and only little preoperative information is available. In order to obtain an optimal surgical outcome, careful assessment of preoperative problems and prevention and detection of complications must be done without any delay. Preoperative carotid duplex scan should be performed in every case to assess the steno-occlusive lesion or unstable plaque, which affect the surgical strategy (eg. selection of arterial cannulation site and cerebral protection). Regional cerebral oxygen saturation (rSO2) must be monitored in all the operation. If intraoperative drop in rSO2 is detected, administration of inotropic agents and increase in cardiopulmonary bypass flow is needed to maintain the mean blood pressure at higher level. Intraaortic balloon pumping (IABP) insertion should be considered when rSO2 cannot be recovered with those procedures. We have to keep in mind that many of the patients undergoing emergency surgery are at high risk for coronary artery disease. If one cannot be weaned from cardiopulmonary bypass, coronary artery bypass grafting to a major branch may be performed. Coronary angiography should be performed immediately when ST-T changes in electrocardiogram (ECG) or chest symptoms appear in the postoperative period. Hesitation in making a decision will only jeopardize the situation.

Preoperative visualization of the artery of Adamkiewicz by intra-arterial CT angiography

BACKGROUND AND PURPOSE

CT and MR angiographies have been reported to visualize the artery of Adamkiewicz (AKA) noninvasively to prevent spinal cord ischemia in surgery of thoracic descending aortic aneurysms. The purpose of this work was to compare the usefulness of CT angiography (CTA) with intra-arterial contrast injection (IACTA) with that of conventional CTA with intravenous contrast injection (IVCTA).

MATERIALS AND METHODS

We enrolled 32 consecutive patients with thoracic or thoracoabdominal aortic aneurysms who were scheduled for surgical repair or endovascular stent-graft treatment. All of the CTA images were obtained using a 16-detector row CT scanner and 100 mL of contrast material (370 mg/mL) injected at a rate of 5 mL/s. Contrast was injected via the antecubital veins of 15 patients and via a pig-tail catheter placed at the proximal portion of the descending aorta in 17 patients who underwent IVCTA and IACTA, respectively. Two datasets were reconstructed from 2 consecutive scans. The AKA was identified as a characteristic hairpin curved vessel in the anterior midsagittal surface of the spine and by the absence of further enhancement in the second rather than in the first phase. Continuity between the AKA and aorta was confirmed when the vessel could be traced continuously by paging the oblique coronal multiplanar reconstruction or original axial images.

RESULTS

Intra-arterial contrast injection was significantly more sensitive in identifying the AKA than IVCTA: 16 (94.1%) of 17 versus 9 (60.0%) of 15 (P = .033). Continuity between the AKA and aorta through intercostal or lumbar artery was confirmed in 14 (87.5%) of 16 and 5 (55.6%) of 9 of the IACTA and IVCTA groups, respectively.

CONCLUSION

Intra-arterial contrast injection detected the AKA at a high rate and verified continuity from the aorta to the AKA.

Five-band microwave radiometer system for non-invasive measurement of brain temperature in new-born infants: system calibration and its feasibility

Recent simulation studies have shown that a technique of multi-frequency microwave radiometry is feasible for non-invasive measurement of deep brain temperatures in the new-born infants. A five-band microwave radiometer system has been developed, and its operation in a normal electromagnetic environment is checked. Five receivers operating with a waveguide antenna and at center frequencies of 1.2, 1.65, 2.3, 3.0 and 3.6 GHz (0.4 GHz bandwidth) are calibrated using a temperature-controlled water-bath. Temperature resolutions obtained for each receiver are 0.183, 0.273, 0.148, 0.108 and 0.118 K, respectively. A temperature retrieval simulation based on these resolutions and the previously proposed algorithm shows that the confidence interval, as produced by thermal noise, is 0.62 K for the retrieved central brain temperature. If the conductivity of brain is estimated wrong by 10 %, this will result in an error of 0.3-0.4 K. The result of this work is encouraging for realization of radiometric measurement of temperature profile in a baby's head.

Naturally acquired regulatory mechanism of perioperative cytokine response in neonates

The inflammatory reaction is known to be controlled in neonates. We clarified the characteristics of cytokine profile in neonatal patients and assess its clinical significance. Serum levels of interleukin (IL)-6 and IL-1 receptor antagonist (ra) were determined in 152 pediatric patients and 33 each of maternal and cord bloods. Supernatant IL-1ra levels of cultured monocytes and granulocytes stimulated with IL-1beta or LPS, and IL-1ra mRNA expression of granulocytes were assayed in 15 each of cord and healthy adult bloods. Although surgical stress in neonates was heavier than that in infants, there was no difference in the occurrence of postoperative morbidity and mortality. In neonates, the perioperative serum level of IL-1ra was significantly raised, and the postoperative IL-6 response was well controlled. The serum concentration of IL-1ra in cord blood was not different from that in maternal blood, whereas, the serum concentration of IL-6 in cord blood was significantly reduced than that in maternal blood. In granulocytes, significantly more IL-1ra was produced from cord than from adult blood. An IL-1ra predominant immune status in neonates may be a naturally acquired adaptation system and play a crucial role in attenuating acute inflammatory reaction in a vulnerable host defense.

Aortic and vena caval reconstruction with retroperitoneal lymph node dissection for metastatic germ cell tumor

A 49-year-old man who had a huge testicular tumor with retroperitoneal lymph node metastasis and bilateral multiple pulmonary metastases was referred to our hospital. Firstly orchiectomy was done obtaining the pathological diagnosis of mixed type germ cell tumor. After cisplatin-based chemotherapy, he underwent resection of the retroperitoneal lymph node involving the abdominal aorta and the inferior vena cava. Both great vessels were resected with the tumor and reconstructed with prosthetic grafts. Two months after the laparotomy, 12 metastatic nodules in the left lung were resected. Seven months later, he furthermore underwent resection of 4 metastatic nodules in the right lung. Microscopically, all resected metastatic tumors were diagnosed to be mature teratoma without viable malignant cells. The patient remains well 30 months after the first operation. Follow-up CT scan demonstrates patency of aortic and vena caval bypass grafts without local recurrence or distant metastasis.

Redo aortic valve replacement with ''porcelain'' aorta in an aortitis patient. A case report

We report a successful reoperation of aortic valve replacement with the severely calcified, ''porcelain'' aorta due to Takayasu's disease. The patient was a 46-year-old female diagnosed with aortic prosthetic valve failure. Takayasu's aortitis had been noted at 17 years old and the patient underwent aortic valve replacement for aortic regurgitation at age 32. Chest CT scan revealed severe circumferential calcification of the whole thoracic aorta. Echocardiography revealed 100 mmHg of pressure gradient across the aortic prosthetic valve with pannus formation. Replacement of the aortic prosthetic valve was performed using the selective cerebral perfusion method under deep hypothermia. The postoperative course was uneventful without any neurological disorder. Selective cerebral perfusion was a useful method to avoid cross clamping in severely calcified ascending aortic.