Approximate charge and transition energy cross-section scaling for excitation of atoms colliding with multicharged ions

PURPOSE: To determine if magnetic resonance (MR) imaging enables differentiation of adhesions from tendon rupture after repair of digital flexor tendon injuries. MATERIALS AND METHODS: The reference group comprised eight tendon sutures with a good clinical outcome. Axial and sagittal spin-echo sequences and three-dimensional gradient-echo sequences with curved reconstructions were analyzed in 63 injured fingers. Reoperation was performed in 41 fingers. RESULTS: MR imaging depicted isolated peritendinous adhesions (n = 31), most often with a continuous, uniform tendon (sensitivity 91%, specificity 100%). There were two types of rupture: frank rupture (n = 140; sensitivity 100%, specificity 100%) or elongated callus (n = 18; sensitivity 100%, specificity 94%). Tendon gap was significantly longer in frank rupture (P = .0011). Thin fibrous continuity existed with elongated callus. Tenolysis was sufficient when the callus was short and mature with predominant new collagen fibers. Axial spin-echo sections were essential, as they showed the maturation of the callus. CONCLUSION: MR imaging may enable distinction among several complications that occur after repair of an injured digital flexor tendon.     

One hundred years of orthopedics in the Netherlands. X. Sports injuries

Sports injuries result from frequently repeated similar movements performed with submaximal force. In practice the term is also used, incorrectly, for many other injuries sustained during, or even outside, the practising of sports. Running may lead to injuries of muscles (rupture, chronic compartment syndrome), of tendons (peritendinitis, tendinosis, partial rupture, insertion tendinitis), of bone (stress fracture) and of cartilage (athrosis). Jumping mostly puts the ankle at risk, especially of development of an anterior or posterior impingement syndrome. Throwing puts much strain on the shoulder muscles; possible problems are microruptures in the rotator cuff, avulsion of the glenoid rim, chronic tendinitis of the biceps tendon and entrapment of the suprascapular nerve. The main element of the treatment is rest. If symptoms persist, surgery may be considered. Previous diagnostic imaging may then be of value.     

Bilateral Achilles tendon rupture: a report on two cases

Two cases of traumatic bilateral Achilles tendon rupture are reported. One of the patients was a healthy middle-aged man, who had been an active national-level gymnast 20 years earlier. He had not suffered any complaints of Achilles tendons before. The ruptures occurred when, after a sauna, he showed his guests a vault forwards, which he had been able to perform easily. This time the landing took place on the toes, causing a high peak stretch to the calf muscles and Achilles tendons. The total rupture of both Achilles tendons was treated surgically, with an excellent result 2 days after the trauma. End-to-end suturation and a fascial flap plasty were made on both sides. No macroscopic degeneration could be detected on the rupture sites. He was allowed to walk freely 6 weeks after the surgery. The second case was a 54-year-old woman, who had suffered from Achilles tendinitis and peritendinitis for 2 years. Both tendons had been surgically treated, and severe adhesions and local degenerative changes had been found. The tendon rupture occurred when she injured her left ankle while getting out of the car. Two days later she fell at home, because of the weakness of the left side, and consequently the right Achilles tendon was injured. She was treated conservatively for 10 days, before the surgery was performed. Both tendons were ruptured and an extensive degeneration of the area was observed. The right side suffered from a rerupture, which was again treated surgically. After surgery the recovery was slow, but the final result 3 years later was moderate. Neither of the patients had any systemic diseases.     

Imaging the long head of biceps tendon--a pictorial essay emphasizing magnetic resonance

Lesions of the long head of the bicepstendon (BT) are seen in association with tears of the rotator-cuff, particularly lesions of the subscapularis tendon and the rotator-interval. The frequency of positive MR-findings at the BT is approximately 25%. The pathologic alterations include complete medial luxation, subluxation and entrapment by the subscapularis tendon, tendinitis or tendovaginitis and lesions at the origin of the tendon at the superior labrum (superior labrum anterior to posterior (SLAP)--lesions). The imaging signs of BT pathology on MR include an abnormal course and position of the tendon, alterations in shape and changes in signal-intensity (SI), obliteration and thickening of the tendon-sheath. In long standing intra-articular BT rupture, neo-insertion of the tendon in the bicipital sulcus may ensue. The long BT needs to be visualized in transaxial, coronal oblique and sagittal oblique projections. Besides serving as stabilizer of the long head of biceps muscle, the BT is also an important stabilizer of the anterior joint capsule.     

Calcification of the tibialis posterior tendon: a case report and literature review

The tibialis posterior muscle and tendon are subject to a number of pathological conditions and injuries that have recently received much attention in the literature. Because of its function as a main stabilizer of the subtalar complex against hindfoot valgus and forefoot pronation, the mechanical demand on the posterior tibial tendon is high. Problems with dislocation, tenosynovitis, rupture, and laceration have all been described with this tendon. In this report, we present a case of dysfunction of the posterior tibial tendon associated with chronic tendinitis and intratendinous calcifications. After removal of the calcifications, the patient became asymptomatic and returned to work. Proposed etiologies of these calcifications are discussed.     

Histopathological findings in chronic tendon disorders

Tendon injuries and other tendon disorders represent a common diagnostic and therapeutic challenge in sports medicine, resulting in chronic and long-lasting problems. Tissue degeneration is a common finding in many sports-related tendon complaints. In the great majority of spontaneous tendon ruptures, chronic degenerative changes are seen at the rupture site of the tendon (1). Systemic diseases and diseases specifically deteriorating the normal structure of the tendon (i.e. foreign bodies, and metabolic, inherited and infectious tendon diseases) are only rarely the cause of tendon pathology. Inherited diseases, such as various hereditary diseases with disturbed collagen metabolism and characteristic pathological structural alterations (Ehlers-Danlos syndrome, Marfani syndrome, homocystinuria (ochronosis)), represent approximately 1% of the causes of chronic tendon complaints (2), whereas foreign bodies are somewhat more common and are found in less than 10% of all chronic tendon problems (1). Rheumatoid arthritis and sarcoidosis are typical systemic diseases that cause chronic inflammation in tendon and peritendinous tissues. Altogether, these 'specific' disorders represented less than 2% of the pathological alterations found in the histological analysis of more than 1000 spontaneously ruptured tendons (1, 3, 4). In this material, degenerative changes were seen in a great majority of the tendons, indicating that a spontaneous tendon rupture is a typical clinical end-state manifestation of a degenerative process in the tendon tissue. The role of overuse in the pathogenesis of chronic tendon injuries and disorders is not completely understood. It has been speculated that when tendon is overused it becomes fatigued and loses its basal reparative ability, the repetitive microtraumatic processes thus overwhelming the ability of the tendon cells to repair the fiber damage. The intensive repetitive activity, which often is eccentric by nature, may lead to cumulative microtrauma which further weakens the collagen cross-linking, non-collagenous matrix, and vascular elements of the tendon. Overuse has also been speculated to cause chronic tendon problems, by disturbing the micro- and macrovasculature of the tendon and resulting in insufficiency in the local blood circulation. Decreased blood flow simultaneous with an increased activity may result in local tissue hypoxia, impaired nutrition and energy metabolism, and together these factors are likely to play an important role in the sequence of events leading to tendon degeneration (4). A sedentary lifestyle has been proposed as a main reason for poor basal circulation of the tendon, and presumably is at least partly responsible for the high number of tendon problems in people with a sedentary lifestyle who occasionally take part in high physical activity sports events.     

Patellar tendon rupture in five deer

Acute unilateral or bilateral rupture of the patellar tendon was diagnosed in 5 aged obese female Pere David's deer housed at a zoological park. Rupture occurred after an episode of sudden exertion in 4 of 5 deer. Fragmentation, degeneration, necrosis, and mineralization of ruptured patellar tendon fibers were found on histologic examination. Similar changes were often seen in intact contralateral tendons that did not have gross lesions. Patellar tendon rupture in humans is associated with concurrent systemic disease, such as systemic lupus erythematosus, rheumatoid arthritis, or chronic renal failure. Without evidence of underlying systemic disease, spontaneous patellar tendon rupture in deer can be considered a sequela to age-related tendinous degeneration compounded by sudden exertion and chronic overload attributable to obesity.     

Diseases of the Achilles tendon in dogs and cats

Dogs and cats rarely have problems with the Achilles tendon and if so, it usually results from a direct trauma. Prime area for injuries is the insertion on the tuber calcanei or directly proximal. One defers between complete and partial ruptures, acute and chronic injuries as well as displacement of the tendon of the superficial digital flexor muscle. In 38 cases (33 dogs and five cats) the clinical examination, radiology, ultrasonography and therapy are shown. Usually the clinical examination is sufficient for a diagnosis (hyperflexion of the hock and weight-bearing on the plantar surface of the metatarsus). The radiology primarily shows up abnormalities on the calcaneus, mineralisations of the tendon and allows the assessment of implants. Ultrasonography is the diagnostic imaging of choice for judgement of tendon diseases as well as the progress of their healing. Tendon suture is advisable if the rupture is open, fresh and/or complete and in cases of luxation of the superficial digital flexor muscle. Immobilisation of the tarsus in hyperextension seems to be of utmost importance no matter if an operative or conservative therapy is chosen.     

Magnetic resonance imaging scanning in the diagnosis of zone II flexor tendon rupture

This study was undertaken to determine the usefulness of magnetic resonance imaging (MRI) in the diagnosis of flexor tendon rupture in patients who had prior surgery. Magnetic resonance imaging scans were performed on 11 digits (16 tendons) with the clinical diagnosis of flexor tendon rupture. Clinical suspicion correlated with MRI and surgical findings. Clinical examination yielded a 60% accuracy in diagnosis. MRI differentiated rupture from adhesions with a 100% accuracy rate. The MRI scan is a valuable tool in diagnosing tendon ruptures and may help reduce the incidence of unnecessary tendon explorations.     

Kakapo, a novel cytoskeletal-associated protein is essential for the restricted localization of the neuregulin-like factor, vein, at the muscle-tendon junction site

In the Drosophila embryo, the correct association of muscles with their specific tendon cells is achieved through reciprocal interactions between these two distinct cell types. Tendon cell differentiation is initiated by activation of the EGF-receptor signaling pathway within these cells by Vein, a neuregulin-like factor secreted by the approaching myotube. Here, we describe the cloning and the molecular and genetic analyses of kakapo, a Drosophila gene, expressed in the tendons, that is essential for muscle-dependent tendon cell differentiation. Kakapo is a large intracellular protein and contains structural domains also found in cytoskeletal-related vertebrate proteins (including plakin, dystrophin, and Gas2 family members). kakapo mutant embryos exhibit abnormal muscle-dependent tendon cell differentiation. A major defect in the kakapo mutant tendon cells is the failure of Vein to be localized at the muscle-tendon junctional site; instead, Vein is dispersed and its levels are reduced. This may lead to aberrant differentiation of tendon cells and consequently to the kakapo mutant deranged somatic muscle phenotype.     

Calcifying tendinitis: a new concept of its pathogenesis

To elucidate the pathogenesis of calcifying tendinitis, clinical and morphological investigations were done on 46 surgically treated cases. Contrary to the prevalent concept of degeneration preceding dystrophic calcification, we found no evidence for an active or a healed degenerative process. The affected tendon was transformed into fibrocartilage with a predilection for calcification. The formative phase of calcification was followed in course of time by a resorptive phase during which the deposits were surrounded by phagocytosing cells. There was a concomitant proliferation of vascular channels. We found a significant correlation between severe pain and histological signs of resorption. The pathogenetic mechanism of calcifying tendinitis should be reassessed as a unique disorder of the musculotendinous cuff.     

Scapholunate interosseous ligament sectioning adversely affects excursions of radial wrist extensor and flexor tendons

Excursions of tendons around the scaphoid were measured in 6 fresh cadaver forearms to evaluate the role of the scapholunate interosseous ligament (SLIL) in wrist joint motion. Excursions of the extensor carpi radialis longus (ECRL) and brevis (ECRB) tendons and the flexor carpi radialis (FCR) tendon were continuously recorded during wrist flexion, extension, and radial and ulnar deviation. Tendon excursions were measured in the intact wrists and after complete sectioning of the SLIL. Tendon excursions were altered significantly in the major ranges of wrist motion after SLIL sectioning. After ligament sectioning, excursions of the ECRL and ECRB tendons increased significantly in wrist flexion and extension. Excursions of the FCR tendon increased significantly during wrist extension and ulnar deviation. These findings support the concepts that integrity of the SLIL plays an important role in wrist function and that injury of the ligament may cause clinical problems.     

Achilles tendinitis

Achilles tendinitis is a common condition of overuse seen in active individuals. It is multifactorial, usually due to a combination of anatomic and biomechanical characteristics along with poor training technique. Pathologic changes can involve the surrounding tissue (bursae, paratenon) or the tendon itself and can occur both at its insertion into the calcaneous and the critical hypovascular zone. A clear understanding of the cause and stage of the condition is critical for successful treatment, be it conservative or surgical. Recent advances in surgical technique and postoperative rehabilitation have been promising in returning individuals to their previous levels of activity.     

Iliopsoas bursitis and tendinitis. A review

This review examines the diagnosis and management of iliopsoas bursitis and/or tendinitis. It is a relatively uncommon and unrecognised cause of anterior hip pain and anterior snapping hip. In view of its pathology, iliopsoas bursitis might be better referred to as iliopsoas syndrome. It can usually be diagnosed by history and physical examination, though real time ultrasound may be useful in confirming the diagnosis. Magnetic resonance and computerised tomography imaging have limited roles in its diagnosis, but may identify other pathology or surgical lesions. Nonoperative management has not been well established. Surgical management does not guarantee treatment success. There is a need for further research into both diagnostic and treatment options for those patients with iliopsoas bursitis/tendinitis.     

Tendon repair using flexor tendon splints: an experimental study

Mechanical strength of tendon repair using Dacron tendon splints across the laceration site were evaluated in human cadaver profundus tendons; the splints were placed both on the dorsal surface and internally within the tendon substance. Comparison was made to modified Kessler, Becker, and Savage repair techniques. Ultimate tensile strength was 2.55 kgf for the Kessler, 3.00 kgf for the Becker, 8.29 kgf for the Savage, 8.46 kgf for the internal tendon splint, and 8.10 kgf for the dorsal tendon splint; the Savage and both Tendon Splints techniques had significant higher tensile strength than the Kessler and Becker. Gap strength was 1.44 kgf for the Kessler, 2.22 kgf for the Becker, 2.45 kgf for the Savage, 2.05 kgf for internal tendon splint, and 3.15 kgf for the dorsal tendon splint. The dorsal tendon splint technique showed significant greater gap strength than the other four techniques. There was no significant difference in the magnitude of the gap during cyclic testing of these techniques; however, three of seven Kessler repairs failed and one of six Becker repairs failed. The results of these cadaver studies suggest that both tendon splint repair techniques are comparable to the Savage and may have sufficient strength to allow postoperative active motion against minimal resistance. Further in vivo testing is in order.     

Patellar whiskers and acute calcific quadriceps tendinitis in a general hospital population

Described is a case of acute calcific quadriceps tendinitis which presented as monoarticular arthritis. A survey of general hospital patients revealed a 7% incidence of calcification of the superior patellar tendon. The most common concurrent abnormality was degenerative joint disease (94%); concomitant chondrocalcinosis was not seen. The "patellar whisker" is a relatively common x-ray finding that may be the clue to an uncommon cause of acute arthritis.     

Cyclic testing of flexor tendon repairs: an in vitro biomechanical study

Forty cadaveric flexor digitorum profundus tendons were repaired using the Tajima, Halsted, Silfverskiold, or Savage techniques. The tendons were cyclically loaded in sets of 4,000 cycles beginning at 25 N and increasing by 10-N increments until failure occurred. Gap formation was continuously monitored with an extensiometer. Only the Savage repair group consistently withstood 4,000 cycles of 25-N loading, with respect to 2-mm gap formation and repair rupture. Tendon repairs subjected to cyclic loading demonstrated gap formation and repair rupture at lower loads than with static testing. Of the methods of flexor tendon repair tested, only the Savage technique could withstand simulated early active motion.     

Case report: can sacroiliac joint dysfunction cause chronic Achilles tendinitis?

This case study discusses the possible relationship between chronic Achilles tendinitis and sacroiliac joint dysfunction. The patient presented is an active pole jumper, competing at both the national and international levels. He suffered from chronic Achilles tendinitis during the 1994-95 season, and conservative treatment applied locally was not successful. The athlete discarded the possibility of operative debridement of the tendon. Instead, an evaluation of the kinetic chain of the lower extremity and pelvic-lumbar area was performed, and the athlete was diagnosed with sacroiliac joint dysfunction and Achilles tendinitis. Evaluation findings, treatment program, and treatment outcome are also presented. The literature regarding sacroiliac joint mechanics and biomechanics of the foot-knee-hip and pelvic area is discussed and used to support the author's thesis that sacroiliac joint dysfunction, in this case a backward rotation of the right ilium, may have changed the kinematic chain of the lower extremity and caused a tendinitis in the Achilles tendon of the affected leg. Sacroiliac joint function and dysfunction, the reliability of sacroiliac joint mobility tests, and the validity of treatment programs are still considered controversial, and more research is needed to understand these mechanisms.     

The growth inhibitory effect of N1,N12-bis(ethyl)spermine in small cell lung cancer cells is maintained in cells expressing the c-myc and Ha-ras oncogenes

OBJECTIVE: The purpose of this study was to assess the diagnostic role of MR arthrography in patients with tendinopathy or rupture of the long biceps tendon. MATERIALS AND METHODS: MR arthrograms of 42 consecutive patients with arthroscopic or surgical confirmation of diagnosis (16 normal biceps tendons, 19 with tendinopathy, and seven with ruptures) were analyzed independently by two radiologists. Visibility of the biceps tendon, caliber changes, contour irregularities, and signal intensities were assessed separately in the parasagittal and axial planes. In addition, the two radiologists made an overall evaluation of abnormalities of the biceps tendon using both MR imaging planes. RESULTS: The most reliable MR findings for tendinopathy were caliber changes (sensitivity was 59% for observer 1 and 82% for observer 2; specificity was 88% and 64%, respectively) and signal abnormalities (sensitivity, 77% and 88%, respectively; specificity, 75% and 43%, respectively) in the parasagittal plane. Absence of visualization of the tendon in the parasagittal plane was a reliable sign for rupture (sensitivity, 86% and 86%, respectively; specificity, 94% and 87%, respectively). The overall sensitivity for detecting abnormalities (tendinopathy or rupture) was 92% for observer 1 and 89% for observer 2. Specificity was 56% and 81%, respectively. CONCLUSION: MR findings of tendinopathy and rupture of the biceps tendon are subtle. However, the combination of several MR criteria in two imaging planes makes a reasonably accurate diagnosis possible. The biceps tendon should not only be assessed in the bicipital sulcus on axial images but also on parasagittal images.     

Development of endometriosis from embryonic duct remnants

Closed rupture of the anterior tibial tendon is rare. Fewer than 50 cases have been reported in the literature, perhaps because the symptoms are often neglected by the patient as well as by the doctor. Most often the rupture occurs as a consequence of a sudden plantar flexion of the ankle and pre-existing degenerative changes of the tendon tissue due to systemic disease or iatrogenic local corticoid injections. Clinically, the tendon rupture presents as acute weakness of the ankle extensors without reddening, swelling or neurological signs. Differential diagnoses such as anterior tibial syndrome and peroneal nerve palsy can thus be excluded. During the clinical examination the distal stump and the discontinuity of the anterior tibial tendon are often palpable. The clinical diagnosis can be confirmed by an ultrasound examination. An operation may be undertaken up to 3 months after the injury. Preferred procedures are end-to-end anastomosis and transosseous refixation of the tendon, followed by a plaster cast for 6 weeks post-operatively. High-risk patients can be treated conservatively, but the functional results are less satisfactory. We describe a case of an acute closed rupture of the anterior tibial tendon. A yet unpublished method of osseous reinsertion of the tendon is presented.