Biomedical subjects

Albrecht Harders

Publications and source records attributed to Albrecht Harders.

3 recordsLinked to original sources

PubMed2006

Subsidence of the wing titanium cage after anterior cervical interbody fusion: 2-year follow-up study.

OBJECT: Cage subsidence occurs after anterior cervical discectomy and fusion (ACDF). The aim of this prospective study was to evaluate subsidence and total segmental height after implantation of a newly designed Wing titanium cage. Furthermore, alignment of the entire cervical spine was analyzed 2 years after surgery. METHODS: Fifty-four patients (26 women and 28 men) whose mean age was 48.3 years underwent ACDF. Follow-up examinations were performed at discharge and 6, 12, and 24 months postoperatively by an independent investigator. The clinical course was evaluated using the visual analog pain scale and the Prolo scales. Measurements of subsidence and total segmental height were conducted, and the alignment of the entire cervical spine was classified using two methods. In 54 patients 64 levels were fused. The patients noted a significant reduction of pain, and scores on both Prolo scales were significantly improved. At the 2-year follow-up examination, subsidence was present in 30 of the 67 fused segments. There was a statistically significant correlation between subsidence and the presence of posterior spondylosis at the initial surgery. Furthermore, there was a significant correlation between reduction of total segmental height and the presence of subsidence; however, subsidence did not prevent the development of a solid bone arthrodesis (fusion rate 98%) or have an adverse effect on the alignment of the cervical spine. CONCLUSIONS: Titanium Wing cage-augmented ACDF was associated with comparatively good long-term results. Subsidence was present but did not cause clinical complications. Furthermore, radiological studies demonstrated that the physiological alignment of the cervical spine was preserved and a solid bone arthrodesis was present at 2 years after surgery.

Adult↗

PubMed2005

Vibrography during tumor neurosurgery.

OBJECTIVE: The aim of this study was to determine whether elastography, a sonographically based real-time strain imaging method for registering the elastic properties of tissue, can be used in brain tumor surgery. METHODS: A modification of classic elastography called vibrography was applied in these measurements with static compression replaced by low-frequency axial vibration. Twenty patients were examined with this technique during brain tumor surgery. A conventional sonographic system with a custom-designed radio frequency (RF) interface was used. The RF data were digitized with a 50-MHz, 12-bit peripheral component interconnect analog/digital converter for real-time or offline processing. Sonographic RF data were acquired with a 6.5-MHz endocavity curved array. A special applicator equipped with a stepping motor moved the ultrasonic probe and produced a low-frequency mechanical vibration of approximately 5 to 10 Hz with a vibration amplitude of 0.3 mm. RESULTS: Detection of tumors was possible in 18 of 20 cases. Brain tissue was normally color coded orange or red. Three major groups of tumors with different elastic properties relative to brain tissue could be differentiated. In 3 cases, the stiffness of the tumor was identical to that of brain tissue, but the tumors were surrounded by a thin yellow border. Six tumors displayed higher strain than brain, whereas 7 tumors exhibited lower strain than the surrounding cerebrum. Two patients could not be assigned clearly to either of these groups. CONCLUSIONS: These findings indicate that vibrography is a feasible imaging method for brain tumor surgery and may have numerous potential applications in neurosurgery if further improvements are made.

Adult↗

PubMed2003

Intracerebral abscess after abutment change of a bone anchored hearing aid (BAHA).

OBJECTIVE: Brain abscesses are life-threatening and sometimes difficult to detect. A brain abscess after placement, manipulation of a bone anchored hearing aid, or a periauricular implant for fixation of an ear prosthesis has never been reported in the literature. PATIENT: A 42-year-old man suffered from a right-sided temporodorsal brain abscess after change of a bone anchored hearing aid abutment. The fixture itself had been inserted 8 years before without any complications in the peri- or postoperative period. A CT-guided puncture of the abscess could be performed via the screw-hole in the temporal bone after removal of the fixture, and the patient was treated with antibiotics. RESULTS: The outcome of the procedure was good without neurologic deficits for the patient. CONCLUSION: The insertion of periauricular screw implants bears the risk of meningeal lesions as well as a small risk of purulent intracranial and intracerebral complications perioperatively or in the context of later manipulations. Minimally invasive therapy of such brain abscesses can be performed by removal of the foreign body, CT-guided puncture, and antibiotic medication.

Adult↗