Distal Biceps Femoris Research Articles

0313: Knee Tendons and Ligaments. Anatomy and Pathology

In the knee, particular strengths of US include the ability to assess traumatic disease affecting tendons and some ligaments. In the quadriceps tendon, US is able to distinguish partial from complete tears thus helping clinical examination that is often misleading. In partial-thickness tears, the superficial tendon layer (from the rectus femoris) is the first involved, followed by the intermediate one (from the vastus medialis and lateralis). In complete tears, the tendon can be retracted at variable distance: the medial and lateral patellar retinacula should also be carefully evaluated because they are often involved. In patellar tendinosis (jumper's knee), chronic microtrauma between the undersurface of the patellar insertion and a prominent patellar tip has been assumed to be a causative factor for chronic impingement and secondary degenerative changes of the patellar tendon. Complete patellar tendon tears may follow a direct local injury or represent the end stage chronic tendinopathy. On the medial knee, MCL injuries can be readily diagnosed with US. Partial tears most often affect the meniscofemoral ligament and can be difficult to differentiate from complete ruptures. Pes anserinus tendinopathy is rare and presents with thickened, hypoechoic tendons and bony cortex irregularities resulting from traction injury. On the lateral knee, chronic local impingement of the iliotibial band against the lateral condyle may lead to friction, local inflammation and pain, the so called “runner's knee”. When inflamed, the bursa between the iliotibial band and the lateral condyle is distended by fluid and can be associated with iliotibial band thickening. In the intercondylar fossa, the middle and distal thirds of the PCL can be demonstrated with US as a deep thick hypoechoic band. Ganglion cysts arising in close proximity to the cruciate ligaments can be occasionally identified with US as incidental findings. A rare tendon-related pathology of the posterior knee is the popliteal artery entrapment syndrome. This syndrome is related to compression of the popliteal artery secondary to the anatomic relationships between the vessel and an abnormal medial head of the gastrocnemius or popliteus. When examining the distal biceps femoris, US scanning should be extended cranially to include the musculotendinous junction as it is a common site of sport-related injuries.

Die isolierte Ruptur der Biceps-femoris-Sehne

Traumatic ruptures of tendons in the region of the knee joint are often accompanied by substantial degenerative and inflammatory alterations, especially when the patella and quadriceps tendons are affected. Isolated ruptures of the tendon of the distal biceps femoris muscle at the dorsolateral aspect of the knee are rare and result in an acute reduction of flexion capability. However, tears of the biceps femoris tendon are not associated with degenerative changes. This article reports on the diagnosis and treatment of a 27-year-old football player who suffered an acute isolated rupture of the biceps femoris tendon.

Semitendinosus Allograft Reconstruction of Chronic Biceps Femoris Rupture at the Knee

Surgical treatment of distal hamstring ruptures at the knee is rare and has been reported infrequently in the literature. This article describes a 22-year-old former collegiate football player who had his career cut short secondary to a chronic distal rupture of the biceps femoris at the knee. Reconstruction of the distal biceps femoris tendon with semitendinosus allograft resulted in an excellent clinical outcome and allowed the patient to return to a high level of physical activity. This case presents a unique cause of knee pain and weakness in a young, active patient and a corresponding effective surgical treatment for such an injury.

MRI of the Distal Biceps Femoris Muscle: Normal Anatomy, Variants, and Association with Common Peroneal Entrapment Neuropathy

The objectives of our study were to describe the previously unreported normal MR anatomy of the distal biceps femoris muscle and its relationship with the common peroneal nerve and to present a case in which previously unreported MR evidence of an anatomic variation in the distal biceps femoris muscle was associated with common peroneal entrapment neuropathy. One hundred consecutive 1.5-T knee MR studies of 97 asymptomatic patients were retrospectively reviewed by two observers in consensus for, first, normal anatomy of the distal biceps femoris muscle; second, anatomic variations of the muscle; and, third, the relationship of the muscle to the common peroneal nerve. Measurements of the distal and posterior extents of the short and long heads of the biceps femoris were performed. An MR study of a symptomatic patient with clinical evidence of common peroneal neuropathy associated with a surgically proven anatomic variation of the distal biceps femoris was reviewed. Two MR anatomic patterns were seen in the asymptomatic patient group: First, in 77 knees (77%), the common peroneal nerve was located within abundant fat posterolateral to the biceps femoris; and, second, in 23 cases (23%), the common peroneal nerve traversed within a narrow fatty tunnel between the biceps femoris and lateral head of the gastrocnemius muscles. There was a positive correlation between the distal and posterior extents of the short head of the biceps femoris muscle and the presence of the tunnel. Variations in the posterior and distal extents of the biceps femoris muscle can produce a tunnel in which the common peroneal nerve travels. We also described a case of common peroneal neuropathy secondary to tunnel formation.

Lateral Popliteal Blocks For Postoperative Anesthesia

We present our technique for providing postsurgical pain control in foot and ankle surgeries performed at our institution. The procedure utilizes a lateral approach to the sciatic nerve through the distal biceps femoris muscle with the patient lying in the supine position. The sciatic nerve is blocked near the bifurcation of the common peroneal and posterior tibial nerves. The saphenous nerve is anesthetized through an auxiliary subcutaneous approach. This technique, although simple to perform, provides excellent postoperative pain control and patient satisfaction for 12 to 26 hours. In addition, the need for intraoperative and postoperative narcotic use is minimized, reducing sedation and nausea while facilitating earlier discharge.

Effects of oxygen on regional hemodynamics in hemorrhagic shock.

This study investigated mechanisms of the hemodynamic effects of oxygen in hemorrhagic shock induced by bleeding 30% of the total blood volume in anesthetized rats. An ultrasonic flowmeter was used to monitor regional blood flow. Changes in tissue perfusion were assessed by the laser-Doppler technique. The inhalation of 100% oxygen induced a significant increase in mean arterial blood pressure (MABP) and vascular resistance in the hindquarters, with a concomitant decrease in blood flow in the distal aorta and biceps femoris muscle. In contrast, oxygen did not change vascular resistance in the superior mesenteric artery (SMA) and renal beds and induced a significant increase in blood flow to the renal artery, SMA, and small bowel in hemorrhaged rats. L-Arginine (100 mg/kg iv) but not D-arginine or the vehicle (0.9% NaCl) completely abolished the effects of oxygen on blood pressure and reversed its effects on blood flow and resistance in the hindquarters and biceps femoris muscle. Administration of the nitric oxide (NO) synthase inhibitor NG-nitro-L-arginine methyl ester (50 mg/kg iv) significantly increased MABP and the resistance in the three vascular beds. Pretreatment of hemorrhaged rats with a superoxide dismutase mimic, the NO-stable radical 2,2,6,6-tetramethylpiperidine-N-oxyl (5 mg/kg iv), resulted in significantly diminished effects of oxygen on hindquarter hemodynamics. These results demonstrate a differential effect of oxygen, which increases vascular resistance in the hindquarters without a significant effect in the splanchnic and renal beds, thus favoring an increase in splanchnic and renal perfusion. It is suggested that inactivation of NO by reactive oxygen species may underlie the effects of oxygen on hindquarter vascular tone during shock.

Hamstring Tenotomies in Cerebral Palsy: Long-Term Retrospective Analysis

One hundred seventeen cerebral palsy patients were followed for a mean of 3.4 years after undergoing hamstring tenotomy by proximal semimembranosus release in conjunction with distal semitendinosus and biceps femoris release. Range of motion was significantly improved 1 year after the operation and remained so for 4 years. Thirty percent of nonambulatory patients improved at least one level in activity, some at up to 12 years of age. Minor recurvatum was observed at 1 year but became nearly nonexistent after 3-5 years.