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Biomedical subjects

J Koebke

Publications and source records attributed to J Koebke.

At least 19 recordsLinked to original sources
PubMed2007

Proposal for classification of the suprascapular notch: a study on 423 dried scapulas.

The present study proposes a simple and reproducible method to classify the morphology of the suprascapular notch (SSN), on the basis of specific geometrical parameters that clearly distinguish one type from another. Four hundred twenty-three dried scapulas from the Department of Anatomy in the University of Cologne, Germany, were examined. Five types of SSN were observed: type I, without a discrete notch, 35 (8.3%); type II, a notch that was longest in its transverse diameter, 177 (41.85%); type III, a notch that was longest in its vertical diameter, 177 (41.85%); type IV, a bony foramen, 31 (7.3%); type V, a notch and a bony foramen, 3 (0.7%). For the vertical diameter, we took the maximal diameter of the notch perpendicular to the imaginary line that joins the two superior corners of the notch. For the transverse diameter, we took the diameter perpendicular to the midpoint of the vertical diameter. This classification based on the vertical and the transverse diameters of the SSN suggested a clear distinction of the notch types. This simple classification included all the anatomical variations of the SSN. Using this method, the clinician will be able to define easily and quickly the notch type on a plain radiograph, and perhaps be able to correlate suprascapular nerve entrapment with a specific type of SSN.

Anthropometry↗
PubMed2007

Correlation between the four types of acromion and the existence of enthesophytes: a study on 423 dried scapulas and review of the literature.

The purpose of this study was to correlate the four types of acromial shape with the existence of enthesophytes, which together comprise two important parameters for subacromial impingement syndrome and rotator cuff tears. In addition, a review of the literature was carried out. Four hundred twenty-three dried scapulas were studied at the Department of Anatomy in the University of Cologne, Germany. Four types of acromion were found: the three classical ones as described by Bigliani et al. ([1986] Orthop Trans 10:216) and a fourth one, where the middle third of the undersurface of acromion was convex (Gagey et al. [1993] Surg Radiol Anat 15:63-70). The correlation between the four types of acromion and the presence of enthesophytes at its anterior undersurface was also recorded. The distribution of acromial types was as follows: type I, flat, 51 (12.1%); type II, curved, 239 (56.5%); type III, hooked, 122 (28.8%); and type IV, convex, 11 (2.6%). Enthesophytes were found in 1 of type I (2%), in 19 of type II (7.9%), in 46 of type III (37.7%), and in 0 (0%) of type IV acromions. Overall, 66 (15.6%) out of 423 scapulas had enthesophytes. In all cases, they were localized at the site of the coracoacromial ligament insertion on the acromion. Enthesophytes were significantly (P < 0.05) more common in type III acromions and this combination is particularly associated with subacromial impingement syndrome and rotator cuff tears. In type I and in type IV acromions, the incidence of enthesophytes is very small and, according to other studies, with these two acromial types rotator cuff tears are also rare.

Acromion↗
PubMed2006

Small keyhole transuncal foraminotomy for unilateral cervical radiculopathy.

Interbody fusion after anterior discectomy may lead to acceleration of degenerative changes at adjacent levels. Although the posterior approach preserves the motion segment, decompression of the nerve root is indirect if "hard disc prolaps" is the main cause. Recently, a technique of microsurgical anterior cervical foraminotomy for the treatment of radiculopathy with preservation of the segment mobility was published. In this study, we present this technique with several modifications.Thirteen patients - 5 men and 8 women with an average age of 49 years - with unilateral radiculopathy resistant to conservative treatment underwent microsurgical anterior foraminotomy via a small keyhole transuncal approach. The base of the uncinate process (UP) was directly drilled in the trajectory to the intervertebral foramen without destroying the disc tissue. The vertebral artery between the transverse process was not exposed. Furthermore, the functional anatomy of the uncovertebral joint remained largely intact. All patients experienced complete relief of radiating pain. A cervical collar was not used. Mean follow-up time was 19 months. The mobility of the operated segment was preserved in each patient. No instability of the cervical spine was seen. The microsurgical anterior foraminotomy via a small keyhole transuncal approach is safe, minimally invasive, and represents an effective method to treat unilateral cervical radiculopathy caused by disc prolaps and/or uncovertebral osteophytes. Additionally, the segment mobility is preserved and prevents the acceleration of degenerative changes at adjacent levels.

Adult↗
PubMed2006

Lateral femoral cutaneous nerve and iliac crest bone grafts--anatomical and clinical considerations.

This study investigates the topographical relationship of the lateral femoral cutaneous nerve (LFCN) to the anterior iliac crest and its clinical relevance in the context of bone graft harvesting. In the anatomical part of the study, LFCN was dissected and its course investigated in 34 human formalin-embalmed cadavers. In the clinical part, data of patients who underwent an iliac crest bone grafting procedure were collected and analysed. The obtained results were then compared with the results of other investigators published in the medical literature. From 34 nerves, the lateral branch of 1 LFCN (2.9%) crossed the anterosuperior iliac spine (ASIS) prominence at a distance less than 5mm superolaterally from the most anterior point of the spine. All other nerves ran below the inguinal ligament with an average distance of 14.6mm in the inferomedial direction from the spine. In 4 out of 298 patients (1.3%) who underwent harvesting of monocortical bone grafts from the inner table of the ilium, sensory disturbances in the dermatome of LFCN were observed. After a maximum period of 12 months all sensory disturbances resolved so that no case of permanent sensory impairment was recorded. The relatively low incidences of iatrogenic LFCN damage can be attributed to a standardized surgical concept which employs a lateral incision and layer by layer dissection to the periosteum/iliacal fascia level in order to identify the nerves potentially crossing the iliac crest above the ASIS.

Adolescent↗
PubMed2006

The course of the greater occipital nerve in the suboccipital region: a proposal for setting landmarks for local anesthesia in patients with occipital neuralgia.

The anatomical relationships of the greater occipital nerve (GON) to the semispinalis capitis muscle (SCM) and the trapezius muscle aponeurosis (TMA) were examined to identify topographic landmarks for use in anesthetic blockade of the GON in occipital neuralgia. The course and the diameter of the GON were studied in 40 cadavers (29 females, 11 males), and the points where it pierced the SCM and the TMA were identified. The course of the GON did not differ between males and females. A left-right difference was detected in the site of the GON in the TMA region but not in the SCM region. The nerve became wider towards the periphery. This may be relevant to entrapment of the nerve in the development of occipital neuralgia. In three cases, the GON split into two branches before piercing the TMA and reunited after having passed the TMA, and it pierced the obliquus capitis inferior muscle in another three cases. The GON and the lesser occipital nerve reunited at the level of the occiput in 80% of the specimens. The occiput and the nuchal midline are useful topographic landmarks to guide anesthetic blockade of the GON for diagnosis and therapy of occipital neuralgia. The infiltration is probably best aimed at the site where the SCM is pierced by the GON.

Afferent Pathways↗
PubMed2005

Bone plug length and loading angle determine the primary stability of patellar tendon-bone grafts in press-fit ACL reconstruction.

The present study was conducted to evaluate the influence of bone-plug length on the primary stability of patellar tendon-bone grafts, using a femoral press-fit fixation technique. Forty-eight human PTB grafts with a patellar bone-plug length of 15 mm and 25 mm were obtained from 24 human cadavers (mean age 72 years) and implanted to porcine femora in a press-fit fixation technique. Tensile loading was performed at 10 mm/s until failure at varying loading angles of 0 degrees, 30 degrees and 60 degrees. Compared to 25 mm, a significant decrease of primary graft stability was recorded in the testing of 15-mm bone plugs. For both plug lengths, the ultimate load to failure increased with rising the loading angles. While axial graft loading exclusively caused plug dislocation, the predominant mode of failure was tendon rupture at 60 degrees loading angle. We conclude that 15-mm bone plugs do not result in a sufficient stability for early aggressive rehabilitation and therefore 25-mm bone plugs are recommended for the femoral press-fit technique.

Aged↗
PubMed2005

The arteries of the humeral head and their relevance in fracture treatment.

Bone vascularisation has gained increased interest in relation to the blood supply of bone fragments during treatment of fractures. In the current study the pattern of vascular supply of the proximal humerus was studied in six cadavers by the corrosion technique. Furthermore, the effect of fractures on the vascular supply was also investigated. In all preparations the intraosseous arteries of the humeral head arose from the circumflex arteries, which surrounded the humerus and dispatched branches towards the proximal end. The main vessel was the branch of the anterior circumflex artery, penetrating the major tubercle in six of six cases. Due to the intraosseous arch shape of this vessel it is referred to as the arcuate artery. Besides other smaller vessels, there was also a vascular network arising from the posterior circumflex artery. Their branches penetrated medially at the cartilage bone interface in five of six preparations. The medial bone arteries appear to gain distinctive importance in humeral head fractures by their impact on the vascularisation of the fracture fragments. After disruption of the arterial supply from the arcuate artery, the vascularisation of the head fragments is most likely ensured by this group of vessels. Therefore, necessary repositioning manoeuvres during open reduction of the fracture should be conducted with care in order to preserve these arteries.

Aged↗
PubMed2005

Local administration of TGF-beta1 to reinforce the anterior abdominal wall in a rat model of incisional hernia.

The purpose of this study was to investigate different forms of the local application of TGF-beta(1) for augmentation of the anterior abdominal wall in an appropriate model of an incisional hernia. Sixty male Sprague-Dawley rats were divided into six groups. Artificial defects of the anterior abdominal wall were closed with one of the following methods: running Prolene suture, Vicryl mesh, prolene suture followed by an intramuscular injection of 1 mug TGF-beta(1), Vicryl mesh coated with 1 mug TGF-beta(1), and prolene suture coated with 1 mug TGF-beta(1). A control group did not receive any defect and treatment. Six weeks after operation, tensile strength, collagen content, gene expression of collagen I and III, blood vessels, and thickness of collagen fibres were evaluated. Tensile strength was strongest in the controls (14.2 (10.5-18 N)). There was no increase in tensile strength due to the administration of TGF-beta(1). On the contrary, bolus injection of the growth factor resulted in a significantly decreased strength of the wound tissue when compared to the groups 1, 4, 5, and 6 (9.1 (4.2-9.1 N)). These results correlated with the gene expression of collagen I and III. Local application of TGF-beta(1) did not augment the strength of the abdominal wall after 6 weeks.

Abdominal Wall↗
PubMed2005

[The arteries of the humerus and their relevance in fracture treatment].

BACKGROUND: The purpose of the current work was to study the arterial blood supply of the humerus to evaluate impairments of the blood supply after humeral fractures and different methods of fracture treatment. METHODS: Arterial blood supply of the humerus was studied by corrosion injection technique in 6 cadaver preparations and is compared with the existing literature. RESULTS: Humeral head arteries originate from the circumflex humeral arteries. The major vessel enters the greater tubercle. Another group of vessels accesses the head from medially. The nutrient artery for the shaft enters into the medial third of the shaft. At the distal humerus there are multiple anastomoses with penetrating branches into both condyles and proximal to the radial, coronoid, and olecranon fossae. CONCLUSIONS: Fragments of a proximal humeral fracture usually have an independent blood supply. The medial vessels to the head gain high importance in fractures of the anatomical neck. The nutrient artery lies regularly medial to the humeral mid-shaft and is at risk at open reduction of this region. The abundant vessels at the entire distal humerus ensure sufficient vascularization of the fragments after fracture.

Arteries↗
PubMed2004

[Acetabular shape and cementless cups. Comparison of osteoarthritic hips and implant design].

The anatomy of the hip must be taken into account in order to ensure primary stability of cementless acetabular implants. In this study we analyzed the shapes of osteoarthritic acetabula and compared these to normal non-degenerative acetabula and to pressfit implants. We measured 92 acetabula with osteoarthritic deformations and 35 non-degenerative acetabula. Bone tissue samples from 50 osteoarthritic acetabula were microradiographically analyzed. Furthermore, the size of the entrance plane of 37 pressfit cups was determined. The craniocaudal and ventrodorsal diameters of osteoarthritic acetabula correlate strongly ( r=0.87). In craniocaudal direction, the acetabular diameter correlates significantly to both the radius of the lunate surface ( r=0.42) and the acetabular base ( r=0.54). Osteoarthritic acetabula have a deeper shape as degeneration increases and the entrance plane becomes significantly more circular ( p<0.05). When comparing osteoarthritic and non-arthrotic acetabula, the following values differ significantly (p<0.05): craniocaudal radius of the acetabular base, craniocaudal and ventrodorsal radius of the lunate surface, and ventrodorsal divergence between lunate surface and acetabular base. To reconstruct an acetabular offset which concurs with central points of the femoral head and the radius of the lunate surface, the level of the insert's entrance plane must be outside the entrance planes of the cup and acetabulum. The rims of hemispheric cups need to be trimmed to prevent these cups from extending beyond the acetabular rim.

Acetabulum↗
PubMed2004

Ultrasonographic stress test of the metacarpophalangeal joint of the thumb.

The purpose of this study was to evaluate functional ultrasound as a tool for detecting an ulnar collateral ligament injury of the thumb. The feasability of using ultrasound for imaging the thumb joint space was tested in a pilot study, using ultrasound and dissection in 14 cadaveric hand specimens. To test this method clinically, both metacarpophalangeal joints of the thumb in 461 healthy volunteers were examined using ultrasound (11 MHz) under radial stress. The distance between the innominate tubercle of the first metacarpal head to the proximal phalanx was measured. The mean distance between the first metacarpal head and the proximal phalanx (n = 461) was 4.5 mm (standard deviation, 0.65 mm) on the right side and 4.6 mm (standard deviation, 0.61 mm) on the left side. These data were compared with data of 25 patients with an operative diagnosis of rupture of the ulnar collateral ligament of the thumb. The difference in joint space between the injured and uninjured sides was 2.25 mm (standard deviation, 0.46 mm). The metacarpophalangeal joint space can be reproducibly detected on high-frequency ultrasound. An increased gap seen on ultrasound is indicative of a rupture of the ulnar collateral ligament of the thumb.

Adolescent↗
PubMed2004

[Primary stability of cement free hip cup prostheses--morphometric comparative analysis of two cup types].

An uncemented implanted acetabular cup must ensure primary stability and postoperative osteointegration. For both conditions the immediate postoperative contact between bone and the structured surface of the cup is of decisive importance. Two different types of acetabular cups manufactured by ESKA (standard model and Kapuziner model) were implanted in the innominate bones of elderly deceased persons. After plastination, thin serial sections were obtained. On the basis of X-rays of these sections, contact between bone and the reticulate surface of the cups was quantified. The quality of the contact was analysed densitometrically.

Aged↗
PubMed2003

[In vivo study of degradation of poly-(D,L-) lactide and poly-(L-lactide-co-glycolide) osteosynthesis material].

AIMS: Comparison of the degradation of poly(D,L)lactide (Resorb X) or poly(lactide-co-glycolide) (LactoSorb) in vivo. MATERIAL AND METHODS: LactoSorb and Resorb X osteosynthesis plates were fixed at the lateral aspect of the femora of 26 Chinchilla rabbits using the respective osteosynthesis screws. After intraperitoneal injection of fluorochromes the screw plate bone blocks were resected after 1, 6, 12, 14, 16, 21, 26 months and radiologic, histologic as well as fluorescence microscopic examinations were carried out. RESULTS: Newly formed bone was detectable above and beneath the polymers 1 month after the implantation. The implants were totally covered by newly formed bone after 6 months. While the LactoSorb screws were found to be as birefringent as after 1 month, in the Resorb X screws a continuous resorption by phagocytizing marrow cells starting from the periphery was detectable. Resorb X was totally resorbed in histologic slides 12 months after implantation, while total resorption of LactoSorb lasted 14 months; both polymers were replaced by marrow cells. Bone remodeling was not finished 26 months after implantation in both polymers. CONCLUSION: Resorption of Resorb X was finished earlier than the resorption of LactoSorb. Both materials were found by fluorescence microscope to be completely resorbed after 12 or 14 months, but bone remodeling of the screw holes was not yet finished 26 months after implantation.

Absorbable Implants↗
PubMed2002

Antegrade femoral nailing: an anatomical determination of the correct entry point.

Operative problems in the application of femoral locking nails are frequently related to an unfavourable entry point at the greater trochanter. Especially in more distally located fractures the nail is forced to follow the cortex abutted medullary canal. A wrong defined entry point either in the medio-lateral or dorso-ventral direction inevitably leads to tension between nail and femur. Forceful insertion in this situation may cause disastrous iatrogenic comminution at the fracture side or additional fractures at the proximal femur. To avoid tension between nail and femur the best suited entry point must be defined according to the natural medullary cavity. In 16 human cadaver femora, the natural medullary cavity was opened and after cleaning filled with a radio-opaque substance (barium sulphate). Twelve radiographs where taken from each bone starting with the anterior-posterior view and then turning the bone axially in steps of 15 degrees. From these radiographs, the ideal entry point at the greater trochanter was calculated. In 88% of the specimen the ideal entry point for a straight nail was found constantly at the medial border of the greater trochanter overlaying the tendinous insertion of the piriformis muscle. The axis of the medullary cavity was in average 2.1cm anterior to the dorsal border of the greater trochanter. In a second step the ideal entry point for bend nails was calculated. According to this calculation a bend nail with a radius of 100 cm needs an entry point 0.7 mm anterior to the dorsal edge of the greater trochanter. Overlaying the hook like shape of the posterior part of the trochanter.

Bone Nails↗
PubMed2001

Compartment syndrome of the foot.

The hindfoot compartment syndrome occurs in 10% of cases after calcaneal fracture. We analyzed the pathological anatomical reasons for this syndrome using the 10 feet from cadavers plastinated and cut into 4-mm thick sequential sections. CT scans of patients with calcaneal fractures were then compared with the anatomical findings. The key component of this compartment syndrome is the quadratus plantae muscle. The sustentacular calcaneal fragment causes bleeding from the bone or the medial calcaneal arteries into this compartment. The medial and lateral plantar nerves and vessels are then compressed between the quadratus plantae muscle and the short flexor digitorum muscle. Relieving pressure by surgical decompression of the quadratus plantae compartment via a medial or plantar approach is the recommended treatment.

Anatomy, Cross-Sectional↗
PubMed2001

Extraarticular external fixation in distal radius fractures pinplacement in osteoporotic bone.

External fixation is a well accepted treatment option in distal radial fractures. The fixator can be used in two different ways: joint bridging or extraarticular. The extraarticular technique presumes that the fracture does not involve the radio-carpal joint and that the distal fragment is broad enough to accommodate two fixator screws. Taking into account that the majority of distal radius fractures occur in elderly female patients the question arises whether osteoporotic bone is an obstacle to extraarticular external fixation. Bone slices of 2mm thickness were cut out of six human cadaver radii with a mean age of 76 years (from 65 to 94 years) in the saggital plane. A radiograph of each slice was digitized and the distribution of gray values measured. It was found that the radiographic density was highest at the palmar side of the distal radius in a triangular area built by the palmar lip of the radius. In this region, even in severe osteoporotic bone, strong trabeculae are visible running parallel to longitudinal axis of the radius. Fixator screws inserted into the distal radial fragment especially in an osteoporotic situation should be securely anchored in the palmar lip of the distal radius.

Adult↗
PubMed2001

Pathophysiology of chronic constipation in anorectal malformations. Long-term results and preliminary anatomical investigations.

Posterior sagittal anorectoplasty provides an optimal access to reconstruct the muscle complex in anorectal malformations. It gives much better results than the abdominoperineal pullthrough procedures performed before 1984. However, severe chronic constipation occurs postoperatively in about 10 % of the patients, which can only be treated by washouts. Clinical investigations of 578 patients treated from 1962 to 1984 and from 1985 to 1997 are presented here and both groups are compared to each other. In addition, a new continence score with special regard to chronic constipation and overflow incontinence was used to follow up 133 patients of the second group. The score distinguishes between children above and below the age of 3 years. To study the underlying reasons of severe chronic constipation in children with anorectal malformations, macro- and microanatomical investigations on 4 normal newborns, 3 neonatal piglets with imperforate anus and 25 rectal biopsies from the caecum were performed. The following reasons have been found to be probably responsible for postoperative constipation and overflow incontinence: 1. Malformations of the smooth and striated muscle fibres or connective tissue of the caecum; 2. Malformations of the intramural nerve plexus such as aganglionosis, hypoganglionosis or IND; 3. Malformations and/or iatrogenic lesions of the extramural nerve supply which runs anterior to the rectum and in front of the fascia of Denonvilliers, which can hardly be identified in neonates with imperforate anus. Therefore iatrogenic bladder injuries may occur after PSARP after extended mobilisation of the caecum. The macro- and microanatomical situation in the piglet with imperforate anus is totally different from the human newborn.

Animals↗