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Biomedical subjects

R Ganz

Publications and source records attributed to R Ganz.

At least 55 records · Page 3Linked to original sources
PubMed1987

Laser Doppler flowmetry for clinical evaluation of femoral head osteonecrosis. Preliminary experience.

Most theories concerning osteonecrosis of the femoral head have as their central focus ischemia of bone. This has been difficult to prove because of lack of a method for direct measurement of bone blood flow. The authors evaluated femoral head blood flow in five patients with established femoral head osteonecrosis using laser Doppler flowmetry. Blood flow within the "avascular" segment was lower than that of the normal cancellous bone of the intertrochanteric region. A surrounding zone of hyperemia was noted in four of the five patients. Laser Doppler flowmetry was easy to use and is a reproducible method for direct estimation of bone-blood flow.

Femur Head↗
PubMed1987

The subcoracoid space. An anatomic study.

Soft tissue impingement under the coracoid process has recently been identified as a cause of painful shoulder disability. In this study the normal space between the humeral head and the coracoid process in two functional positions of the arm was measured in an attempt to delineate anatomic risk factors predisposing to subcoracoid impingement. Forty-seven normal shoulders were studied by computerized tomography (CT) in adduction, 20 additionally in forward flexion/internal rotation, which is the position most frequently causing subcoracoid impingement. The distance between the humeral head and the coracoid tip averaged 8.7 mm for the adducted arm and 6.8 mm for the flexed arm. Modifications of the coracohumeral relationship were found to affect the subcoracoid clearance roughly 1.5 times more in flexion than with arm at the side. Subcoracoid impingement appeared particularly likely during forward flexion of a shoulder with a coracoid tip close to the scapular neck and projecting far laterally.

Adult↗
PubMed1987

Glenoplasty for recurrent posterior shoulder instability. An anatomic reappraisal.

Posterior glenoplasty, as performed for the treatment of recurrent posterior shoulder instability, was shown to thrust the humeral head forward and was able to cause symptomatic impingement of the anterior cuff between the coracoid process and the humeral head. Such subcoracoid impingement is relieved by resection of the inferolateral part of the coracoid tip and of the coracoacromial ligament.

Adult↗
PubMed1986

Laser Doppler flowmetry for bone blood flow measurement: correlation with microsphere estimates and evaluation of the effect of intracapsular pressure on femoral head blood flow.

Laser Doppler flowmetry (LDF) was used to measure bone blood flow in the rabbit femoral head and femoral condyles. To correlate the LDF output signal blood cell flux to in vivo blood flow, simultaneous measurements using LDF and 85Sr-labeled microspheres were made in an adult rabbit model. There was no correlation between the two methods for blood flow in the femoral condyles and the correlation between the two methods for blood flow in the femoral head does not achieve statistical significance. An LDF signal of 0.4 V was approximately equal to a microsphere measured flow rate of 0.4 ml blood/g bone/min. The strength of the correlation in the latter case may have been affected by (a) large arteriovenous shunts, (b) inadequate mixing of the microspheres with a left ventricular injection, and (c) insufficient numbers of microspheres present in the bone samples with which to satisfy the mathematical requirements of the microsphere method. When LDF was used to evaluate the effect of elevated intracapsular pressure on femoral head blood flow in skeletally mature rabbits, femoral head subchondral bone blood flow declined with increasing intracapsular pressure from a baseline value of 0.343 +/- 0.036 to a value of 0.127 +/- 0.27 at 120 cm of water pressure. The decline in femoral head blood flow was statistically significant at pressures of 40 cm of water or higher (p less than 0.001), and evaluation of sections of the proximal femora made from preterminal disulphine blue injections confirmed these findings. Intracapsular tamponade has an adverse effect on femoral head blood flow beginning well below central venous pressure and should be considered in the pathophysiology of posttraumatic and nontraumatic necrosis of the femoral head. Laser Doppler flowmetry was easy to use and appears to be a reproducible technique for evaluating femoral head blood flow, offering distinct advantages over the microsphere technique for measuring bone blood flow. Further studies of the in vivo calibration of the LDF method for bone blood flow are necessary for the method to have potential for clinical application.

Animals↗
PubMed1986

Combined osteocutaneous microvascular flap procedure for extensive bone and soft tissue defects in the tibia.

Recent experience with bone healing seems to advocate vascularized bone grafts in cases of large bone gaps or significant scarring, following irradiation, in the presence of low-grade infection, and in congenital pseudarthrosis of the tibia. When extensive bone and skin replacement are needed, the microvascular procedures currently available may not meet specific reconstructive requirements. To augment the advantages of the vascularized fibular graft for tibial substitution (strength, straightness, length, and predictability of vascular supply) with the benefits of free skin, muscle, or musculocutaneous flaps, separate on-demand harvesting of these tissue units and their microvascular combination can be useful in selected cases. In a study of 4 patients, the vascularized fibula was combined with a free latissimus dorsi flap. The procedure was facilitated and shortened by connecting the peroneal vessels to branches of the thoracodorsal or to the scapular circumflex artery and vein outside the operative field. The main supporting vessels of the combined composite tissue block were then anastomosed only to one pair of vessels in the leg.

Adolescent↗
PubMed1985

The role of the coracoid process in the chronic impingement syndrome.

Symptomatic impingement of the rotator cuff between the humeral head and the coracoid process has been studied and three varieties recognised: idiopathic, iatrogenic and traumatic. In all three the clinical findings consisted of pain in front of the shoulder, referred to the upper arm and forearm, and especially felt during forward flexion and medial rotation; the pain could be reproduced by medial rotation with the arm in 90 degrees of abduction, or by adduction with the shoulder flexed to 90 degrees. Patients were relieved of their symptoms by restoring adequate subcoracoid clearance.

Adult↗
PubMed1979

[The combination of fractures of the lower extremity and lesion of the posterior cruciate ligament].

In 400 fractures of the upper and lower leg, 7 patients had an additional lesion of the posterior cruciate ligament. This combination occurs in people, who had a high energy frontal impact in the sitting position. The ligamenteous injury is often overlooked because of multiple injuries and difficulty in examination of a knee joint on a fractured leg. In high velocity injuries of the lower extremity, knee and hip joint injuries must not be overlooked. The diagnosis of knee injury can be made by inspection and palpation of a joint effusion and by a knee joint X-ray, which shows an avulsion fracture of the dorsal tibial spine. Repair is recommended within the first 3 weeks if possible. Later, scarring in the subluxed position and osteoporosis of the fragment will make a reconstruction very difficult.

Adult↗
PubMed1978

[Indication for prosthesis in pertrochanteric fractures].

Trochanteric fractures with concomitant osteoarthrosis of the hip joint present a clear indication for total hip replacement there by treating both the fracture and the joint disease. Trochanteric fractures with an otherwise normal hip joint are usually treated by internal fixation. Under certain conditions (old patient, simple fracture) femoral head or total hip replacement may, however, be preferable. As a rule, duration and technical difficulty of such an operation should not exceed that of any classical method of internal fixation.

Hip Fractures↗