Biomedical subjects

Martin Beck

Publications and source records attributed to Martin Beck.

25 records · Page 2Linked to original sources

PubMed2004

Increased intraarticular pressure reduces blood flow to the femoral head.

Hemarthrosis leading to increased intracapsular pressure after an undisplaced femoral neck fracture is suspected to impair blood flow to the femoral head and may lead to osteonecrosis. We hypothesized that an increase of intraarticular pressure would reversibly decrease the blood flow to the femoral head. Eleven patients having surgical dislocations for treatment of femoroacetabular impingement were included in this study. Saline was injected into the intact intracapsular space while the blood flow to the femoral head was recorded using laser Doppler flowmetry. Injection of saline resulted in an increase in the intracapsular pressure. The injected volume of normal saline until disappearance of the pulsatile signal was on average 20 mL (range, 10-35 mL) with an average intraarticular pressure of 58 mm Hg (range, 25-88 mm Hg). Aspiration of the joint resulted in a return of the pulsatile flow. Hemarthrosis after undisplaced intracapsular fractures of the femoral neck are likely to cause an increase in intracapsular pressure. Decompression of the hematoma to reduce the intracapsular pressure is strongly advocated to optimize blood flow to the femoral head in acute fractures.

Femur Head↗

PubMed2004

Anterior femoroacetabular impingement: part I. Techniques of joint preserving surgery.

The exact pathomechanism responsible for osteoarthritis (OA) of the nondysplastic hip has remained unknown for many years. There is, however, emerging clinical evidence implicating femoroacetabular impingement as an etiologic factor for having early OA of the hip develop. Femoroacetabular impingement is an abutment conflict occurring between the proximal femur and the acetabular rim arising from morphologic abnormalities affecting the acetabulum or the proximal femur, or both. The repetitive mechanical conflict occurring during motion, particularly flexion and internal rotation, can lead to lesions of acetabular labrum and, even more serious, the adjacent acetabular cartilage. Surgical treatment of femoroacetabular impingement focuses on improving the clearance for hip motion and alleviation of femoral abutment against the acetabular rim. We will describe the rationale for the treatment of this condition, and discuss the technique of joint-preserving surgery.

Acetabulum↗

PubMed2004

Anterior femoroacetabular impingement: part II. Midterm results of surgical treatment.

Femoroacetabular impingement has been shown to cause labral and chondral lesions and leads to osteoarthrosis of the hip. With the elimination of the pathogenic cause we hope to prevent or delay additional degeneration of the hip. Fourteen men and five women with a mean age of 36 years (range, 21-52 years) were treated with a surgical dislocation and offset creation of the hip. The followup averaged 4.7 years (range, 4-5.2 years). Using the Merle d'Aubigné hip score, 13 hips were rated excellent to good, with the pain score improving from 2.9 points to 5.1 points at the latest followup. There was no avascular necrosis of the femoral head. Five of the 19 patients, two with Grade 2 osteoarthrosis, two with Grade 1 osteoarthrosis but severe acetabular cartilage damage, and one with untreated ossified labrum had subsequent total hip arthroplasty (THA). In the stable hips without subluxation of the head into the acetabular cartilage defect, no additional joint space narrowing occurred. Surgical dislocation with correction of femoroacetabular impingement yields good results in patients with early degenerative changes not exceeding Grade 1 osteoarthrosis. This procedure is not suitable for patients with advanced degenerative changes and extensive articular cartilage damage.

Acetabulum↗

PubMed2003

Acetabular blood flow during Bernese periacetabular osteotomy: an intraoperative study using laser Doppler flowmetry.

BACKGROUND: The blood flow to the acetabular fragment is of some concern in juxtaarticular pelvic osteotomies used for the treatment of hip dysplasia. No direct measurements have determined the effect of the Bernese periacetabular osteotomy (PAO) on acetabular perfusion. METHODS: Acetabular perfusion was measured by means of laser Doppler flowmetry in 10 patients undergoing a PAO for symptomatic acetabular dysplasia. During the surgical procedure, the intraosseous high energy laser Doppler reliably depicts dynamic changes of small vessel blood flow. Measurements were performed after defined surgical steps to obtain sequential information on the blood perfusion of the acetabular fragment. RESULTS: After complete separation of the acetabular fragment, nine out of 10 patients had pulsatile signals, but the blood flow (BF) significantly decreased by 77%. Corrective positioning of the fragment induced no further drop of the BF signal but a loss of pulsatility in six patients. After a recovery period of about 30 min following preliminary fixation of the fragment, reestablishment of the pulsatile signal and an increase of the BF signal was seen. At termination of the surgical procedure, five out of eight patients, who could be followed throughout the whole procedure, showed a clear pulsatile signal in the supraacetabular area. Bleeding of the supraacetabular cancellous surface could be observed in all acetabula. CONCLUSION: Despite careful preservation of soft tissues during the surgical procedure, a significant reduction of the blood flow in the supraacetabular region has been observed. Nevertheless, a pulsatile signal in more than 60% of the fragments after fragment correction and an increasing signal during the recovery period showed ongoing blood perfusion indicating reversible changes in the measured supraacetabular area. All osteotomies healed within eight weeks without showing signs of necrosis during a minimum follow up of 1 year.

Acetabulum↗

PubMed2003

Acetabular rim degeneration: a constant finding in the aged hip.

During recent years the acetabular labrum has gained increased interest because its degeneration frequently is found in association with early osteoarthritis of the hip. To determine spatial distribution of labral degeneration in the aged hip and to identify the pathologic features triggering this event, an anatomic postmortem and an intraoperative in vivo study were done in 30 cadavers (range, 60-90 years) and in 18 elderly patients (range, 69-97 years) who had hemiarthroplasty for displaced femoral neck fractures. In both groups, no gross anatomic or radiographic abnormalities suggesting advanced osteoarthritis were present. All cadaveric acetabuli (30 of 30) revealed labrum and cartilage damage. Labrum damage (17 of 18) and cartilage lesions (16 of 18) occurred less frequently and were smaller in the elderly patients. Peripheral joint degeneration was most frequent at the superior acetabular rim close to the anterior inferior iliac spine. More centrally localized cartilage lesions were present in 47% of cadavers and in 28% of patients. The majority of femurs (cadavers) (80%) showed reduced narrowing at the anteromedial femoral head-neck junction causing impingement against the corresponding acetabular rim or squeezing of this area into the joint during flexion, whereas the femoral head cartilage appeared normal in all but one hip. Acetabular rim degeneration is a constant finding in the aged hip, which seems to be triggered by femoroacetabular impingement.

Acetabulum↗

PubMed2003

Femoroacetabular impingement: a cause for osteoarthritis of the hip.

A multitude of factors including biochemical, genetic, and acquired abnormalities may contribute to osteoarthritis of the hip. Although the pathomechanism of degenerative process affecting the dysplastic hip is well understood, the exact pathogenesis for idiopathic osteoarthritis has not been established. Based on clinical experience, with more than 600 surgical dislocations of the hip, allowing in situ inspection of the damage pattern and the dynamic proof of its origin, we propose femoroacetabular impingement as a mechanism for the development of early osteoarthritis for most nondysplastic hips. The concept focuses more on motion than on axial loading of the hip. Distinct clinical, radiographic, and intraoperative parameters can be used to confirm the diagnosis of this entity with timely delivery of treatment. Surgical treatment of femoroacetabular impingement focuses on improving the clearance for hip motion and alleviation of femoral abutment against the acetabular rim. It is proposed that early surgical intervention for treatment of femoroacetabular impingement, besides providing relief of symptoms, may decelerate the progression of the degenerative process for this group of young patients.

Acetabulum↗

PubMed2002

Fatal retroperitoneal hemorrhage caused by perforation of a guidewire pin for proximal femur fixation.

A 77-year-old woman with a slightly displaced intertrochanteric two-fragment fracture of the left hip was treated by internal fixation using a screw-nail device (gamma nail). After the operation she became hemodynamically unstable, and ultrasound revealed a large retroperitoneal fluid accumulation in the left lower abdomen. A contrast computed tomogram revealed active hemorrhage next to the quadrilateral surface of the left acetabulum. Selective angiography and embolization were immediately initiated and stopped the bleeding. However, despite the successful treatment of the retroperitoneal hemorrhage, the patient developed an oligosymptomatic myocardial infarction associated with clinical evidence of a cerebrovascular insult and pulmonary decompensation and died 2 weeks after her accident. The hemorrhage in this patient was most likely caused by surgical damage to the obturator artery during placement of the guidewire pin (with threaded tip) to position the screw of the implant.

Aged↗