Rectus diastasis increases risk of burst abdomen in emergency midline laparotomies: a matched case-control study.

PURPOSE: Burst abdomen is a serious complication requiring immediate surgical treatment. This study aimed to investigate the association between rectus diastasis and burst abdomen in patients undergoing emergency midline laparotomy. METHODS: A single-center, retrospective, matched case-control study of patients undergoing emergency midline laparotomy from May 2016 to August 2021 was conducted. Cases (patients who suffered from burst abdomen) were matched 1:4 with controls based on age and sex. Rectus diastasis was evaluated on CT imaging and was defined as a distance of at least three centimeters between the rectus abdominis muscles, three centimeters above the umbilicus. Midline laparotomy aponeurosis closure was standardized during the study period, using a slowly absorbable suture, sutured continuously with small bites of five millimeters and a minimum suture-to-wound ratio of 4:1. The primary outcome was the association between rectus diastasis and burst abdomen, evaluated against other suspected risk factors including obesity, liver cirrhosis, previous laparotomy, midline hernias and active smoking in a multivariate analysis. RESULTS: A total of 465 patients were included in the study, with 93 cases matched to 372 controls. Eighty-four patients had rectus diastasis (35.5% cases vs. 13.7% controls; p = < 0.001). Multivariate analysis found rectus diastasis significantly associated with burst abdomen (OR 3.06, 95% CI 1.71-5.47; p = < 0.001). No other suspected risk factors showed a significant association with burst abdomen. CONCLUSION: Rectus diastasis was highly associated with an increased risk of burst abdomen after emergency midline laparotomy.

Recent Advances in Clinical Natural Language Processing in Support of Semantic Analysis.

OBJECTIVES: We present a review of recent advances in clinical Natural Language Processing (NLP), with a focus on semantic analysis and key subtasks that support such analysis. METHODS: We conducted a literature review of clinical NLP research from 2008 to 2014, emphasizing recent publications (2012-2014), based on PubMed and ACL proceedings as well as relevant referenced publications from the included papers. RESULTS: Significant articles published within this time-span were included and are discussed from the perspective of semantic analysis. Three key clinical NLP subtasks that enable such analysis were identified: 1) developing more efficient methods for corpus creation (annotation and de-identification), 2) generating building blocks for extracting meaning (morphological, syntactic, and semantic subtasks), and 3) leveraging NLP for clinical utility (NLP applications and infrastructure for clinical use cases). Finally, we provide a reflection upon most recent developments and potential areas of future NLP development and applications. CONCLUSIONS: There has been an increase of advances within key NLP subtasks that support semantic analysis. Performance of NLP semantic analysis is, in many cases, close to that of agreement between humans. The creation and release of corpora annotated with complex semantic information models has greatly supported the development of new tools and approaches. Research on non-English languages is continuously growing. NLP methods have sometimes been successfully employed in real-world clinical tasks. However, there is still a gap between the development of advanced resources and their utilization in clinical settings. A plethora of new clinical use cases are emerging due to established health care initiatives and additional patient-generated sources through the extensive use of social media and other devices.

Expression of osteocalcin in the patella of experimentally immobilized and remobilized rats.

The exact mechanisms by which mechanical loading-unloading affects bone tissue are mostly unknown. Recently, osteocalcin, a direct product of osteoblasts, has been shown to reflect the activity of the mineralization phase of the newly formed bone matrix, and therefore, the in situ detection of osteocalcin could be used for studying the effects of physical activity-inactivity on the osteoblast function or bone formation in the target bone. In this study, the effect of various loading states (immobilization and three forms of subsequent remobilization) on the in situ expression of osteocalcin in the rat patellas and their osteotendinous junctions was studied immunohistochemically using a polyclonal rat antiosteocalcin as the primary antibody. Following immobilization for 3 weeks, the immunoreactivity of osteocalcin was markedly decreased or was completely absent in all the patellar areas which normally show intense reaction as a sign of mineralization of the newly formed bone, that is, in the subperiosteal and subchondral regions, in the osteoid tissue that lies on the surface of the trabecular bone, and around the cortical lacunae. The same was true in the mineralized fibrocartilage zone of the osteotendinous junction of the quadriceps tendon. Free remobilization for 8 weeks (free cage activity) could not improve the situation, but after intensified remobilization of the same duration (low and especially high intensity treadmill running) high osteocalcin expression was observed in the above-mentioned anatomic sites. These findings indicate that formation of new bone tissue is rapidly regulated by the loading states of the bone. Higher than normal activity seems to be needed to restore the bone formation from the disuseinduced depression to normal.

Effects of free mobilization and low- to high-intensity treadmill running on the immobilization-induced bone loss in rats.

After an immobilization period of 3 weeks, the effects of free remobilization (8 weeks) as well as low- and high-intensity treadmill running on the bone mineral content (BMC) and density (BMD) of the hindlimbs of Sprague-Dawley rats (n = 70) were studied using a dual-energy x-ray absorptiometric scanner. In the low-intensity running program, the rats were allowed to move freely in the cage for 1 week, after which they started to run on a treadmill twice a day for 7 weeks. The speed of the treadmill was 20 cm/s, with an uphill inclination of 10 degrees. The running time was gradually increased from 20 minutes per session to 45 minutes per session. In the high-intensity group, the program was similar, with the exception that the speed of the treadmill was 30 cm/s, with an uphill inclination of 30 degrees. Immobilization for 3 weeks produced a significant BMC and BMD loss in the immobilized left femur and tibia (mean loss 9.6%, p < 0.001) but did not affect the right free limbs. Both low- and high-intensity running restored mineral content in the immobilized limb; however, an average 5% difference (p < 0.05) in mineral content of the right and left limb bones persisted. In the running groups, the values for the immobilized left limbs were at the same level or exceeded (range 3.8-11.6%, p < 0.05-0.01) and those of the free right limbs exclusively exceeded (range 5.3-15.9%, p < 0.05-0.01) the corresponding values of the age-matched control rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of immobilization, three forms of remobilization, and subsequent deconditioning on bone mineral content and density in rat femora.

Disuse is associated with bone loss, which may not be recoverable. It is not known whether intensified remobilization is beneficial in restoring disuse-related bone loss nor if any such benefit would depend upon continuing mobilization for its maintenance. After an immobilization period of 3 weeks, the effects of free remobilization (11 weeks), and low-and high-intensity treadmill running (11 weeks) with and without subsequent deconditioning (18 weeks) on the bone mineral content (BMC) and density (BMD) of the hindlimb femora of Sprague-Dawley rats (n = 98) were studied using a dual-energy X-ray absorptiometric (DXA) scanner. Our hypothesis was that intensified remobilization is beneficial in restoring the BMC and BMD from disuse to normal while subsequent deconditioning is deleterious to these parameters. Immobilization for 3 weeks produced a significant BMC and BMD loss in the immobilized left femur (range -4.4 to -12.8%; p < 0.05-0.001). In the groups with free remobilization (free cage activity), the body weight-adjusted BMCs and BMDs always remained below those in the controls (range -2.3 to -12.1%; p values ranging from NS to < 0.01). Both low- and high-intensity running restored BMC and BMD in the immobilized limb, the effect being better in the latter group. In both of these groups, the values of the immobilized left limbs and those of the free right limbs exclusively exceeded the corresponding values of the age-matched control rats (left limb values 3.0-21.1% higher with p values ranging from NS to < 0.01; right limb values 7.9-21.4% higher with p < 0.05-0.01). However, after the deconditioning period of 18 weeks, the above described beneficial effects of low- and high-intensity running were lost, the left and right limb BMC and BMD values being lower than those in the age-matched controls (range -3.8 to -8.7%; p values ranging from NS to < 0.05). In conclusion, this study clearly indicates the need for greater than normal activity to restore the BMC and BMD after disuse to normal levels. However, the benefits of intensified remobilization are lost if the activity is terminated, and therefore, after immobilization and disuse, bone loading activities should be continued, perhaps indefinitely.

Heterogeneity of expression of immunohistochemical tumour markers in testicular carcinoma in situ: pathogenetic relevance.

Testicular carcinoma in situ (CIS) is the precursor of germ cell tumours in adults, except for spermatocytic seminoma. The mechanism of the progression from premalignant CIS to invasive and overt tumours is largely unknown. There are currently two main hypotheses: one is that CIS can progress directly to either seminoma or nonseminoma; according to the other, seminoma is the intermediate stage between CIS and nonseminoma. CIS cells express several tumour antigens, such as placental-like alkaline phosphatase (PLAP), TRA-1-60, or the c-kit proto-oncogene protein product (Kit), which are present to varying degrees in the invasive germ cell tumours. In this study, CIS cells adjacent to either pure or combined tumours were examined by double immunohistochemical staining for simultaneous expression of TRA-1-60 (typical for embryonal carcinoma) and either Kit (expressed by seminomas) or PLAP (found mainly in seminomas, but also in some cases of nonseminoma). Marked differences in the expression of these antigens were found among CIS cells, especially those adjacent to mixed tumours. We conclude that CIS is a phenotypically heterogeneous lesion, and that the CIS cells, despite identical morphology and close spatial localization, may be in different stages of progression. The results lend support to the hypothesis that CIS can progress directly to both seminomatous and nonseminomatous tumours.

Free mobilization and low- to high-intensity exercise in immobilization-induced muscle atrophy.

After 3 wk of immobilization, the effects of free cage activity and low- and high-intensity treadmill running (8 wk) on the morphology and histochemistry of the soleus and gastrocnemius muscles in male Sprague-Dawley rats were investigated. In both muscles, immobilization produced a significant (P < 0.001) increase in the mean percent area of intramuscular connective tissue (soleus: 18.9% in immobilized left hindlimb vs. 3.6% in nonimmobilized right hindlimb) and in the relative number of muscle fibers with pathological alterations (soleus: 66% in immobilized hindlimb vs. 6% in control), with a simultaneous significant (P < 0.001) decrease in the intramuscular capillary density (soleus: mean capillary density in the immobilized hindlimb only 63% of that in the nonimmobilized hindlimb) and muscle fiber size (soleus type I fibers: mean fiber size in the immobilized hindlimb only 69% of that in the nonimmobilized hindlimb). Many of these changes could not be corrected by free remobilization, whereas low- and high-intensity treadmill running clearly restored the changes toward control levels, the effect being most complete in the high-intensity running group. Collectively, these findings indicate that immobilization-induced pathological structural and histochemical alterations in rat calf muscles are, to a great extent, reversible phenomena if remobilization is intensified by physical training. In this respect, high-intensity exercise seems more beneficial than low-intensity exercise.

Achilles tendon injuries in athletes.

Two-thirds of Achilles tendon injuries in competitive athletes are paratenonitis and one-fifth are insertional complaints (bursitis and insertion tendinitis). The remaining afflictions consist of pain syndromes of the myotendineal junction and tendinopathies. The majority of Achilles tendon injuries from sport occur in males, mainly because of their higher rates of participation in sport, but also with tendinopathies a gender difference is probably indicated. Athletes in running sports have a high incidence of Achilles tendon overuse injuries. About 75% of total and the majority of partial tendon ruptures are related to sports activities usually involving abrupt repetitive jumping and sprinting movements. Mechanical factors and a sedentary lifestyle play a role in the pathology of these injuries. Achilles tendon overuse injuries occur at a higher rate in older athletes than most other typical overuse injuries. Recreational athletes with a complete Achilles tendon rupture are about 15 years younger than those with other spontaneous tendon ruptures. Following surgery, about 70 to 90% of athletes have a successful comeback after Achilles tendon injury. Surgery is required in about 25% of athletes with Achilles tendon overuse injuries and the frequency of surgery increases with patient age and duration of symptoms as well as occurrence of tendinopathic changes. However, about 20% of injured athletes require a re-operation for Achilles tendon overuse injuries, and about 3 to 5% are compelled to abandon their sports career because of these injuries. Myotendineal junction pain should be treated conservatively. Partial Achilles tendon ruptures are primarily treated conservatively, although the best treatment method of chronic partial rupture seems to be surgery. Complete Achilles tendon ruptures of athletes are treated surgically, because this increases the likelihood of athletes reaching preinjury activity levels and minimises the risk of re-ruptures. Marked forefoot varus is found in athletes with Achilles tendon overuse injuries, reflecting the predisposing role of ankle joint overpronation. Athletes with the major stress in lower extremities have often a limited range of motion in the passive dorsiflexion of the ankle joint and total subtalar joint mobility, which seems to be predisposing factor for these injuries. Various predisposing transient factors are found in about one-third of athletes with Achilles tendon overuse injuries; of these, traumatic factors (mostly minor injuries) predominate. The typical histological features of chronically inflamed paratendineal tissue of the Achilles tendon are profound proliferation of loose, immature connective tissue and marked obliterative and degenerative alterations in the blood vessels. These changes cause continuing leakage of plasma proteins, which may have an important role in the pathophysiology of these injuries. The chronically inflamed paratendineal tissues of the Achilles tendon do not seem to have enough capacity to form mature connective tissue.

Knee injuries in athletes. Review of exertion injuries and retrospective study of outpatient sports clinic material.

About one third of all sports injuries admitted to outpatient sports clinics concern knees. The incidence of different knee disorders in an outpatient sports clinic material and a review of the literature concerning the wide and problematic area of knee exertion injuries in athletes is presented. Exertion injury is defined as non-traumatic pain syndrome in the musculoskeletal system, including typical stress injuries and pain syndromes associated with physical activity but also has other important aetiological factors. 2762 athletes were admitted to the Turku Sports Medical Research Unit's outpatient sports clinic from 1976 to 1983 and 886 (32%) of them, 697 male and 189 female athletes, had suffered knee disorders. Football (soccer) [20.8%], long-distance running (13.1%), volleyball (11.6%), orienteering (7.6%) and ice-hockey (7.2%) had the highest incidence and the most common knee disorders were patellar apicitis (20.4%), Osgood-Schlatter's disease (10.1%), patellar chondropathy (10.0%), ligamentous sprains (9.0%) and meniscus tears (6.9%). The mean age of all athletes with knee disorders was 20.8 years. On an average each complaint caused 2.16 appointments. Careful evaluation of malalignments predisposing the athlete to exertion injury is necessary in the treatment of knee disorders and to avoid the recurrence of the exertion injury due to some biomechanical reason. The authors emphasise the importance of careful clinical examination. Although our review does not include detailed information about injuries originating in a single trauma, it is important to pick up the cases of ligamentous tears early so they can be appropriately repaired. Diagnostic and operative arthroscopy adds a new method in avoiding diagnostic errors and in shortening the postoperative rehabilitation.

Effect of food restriction on tissue carnitine concentration in rats.

The effect of feeding different amounts of a standard laboratory pellet diet on tissue carnitine concentration was studied in four groups of rats. Group I was fed ad libitum, whereas food intake was restricted to 25, 20, and 15g protein/kg body weight/day in group II, III, and IV, respectively. The intake of food, protein, energy and carnitine was constant and adjusted to actual body weight in groups 2-4. Six weeks food restriction had no effect on muscle carnitine. Restricted diet caused lowered concentrations of carnitine in serum (group I, fed ad libitum, total 95.0 +/- 13.8, free 80.2 +/- 2.7; group II total 78.4 +/- 8.4, free 56.9 +/- 4.7; group III total 81.7 +/- 8.8, free 66.0 +/- 8.8; and group IV total 73.8 +/- 8.7, free 59.5 +/- 7.6 micromol/l) and urinary carnitine excretion (group I, total 7.1 +/- 3.3, free 6.3 +/- 3.1; group II, total 2.5 +/- 0.7, free 2.2 +/- 0.7; group III, total 1.9 +/- 0.8, free 1.6 +/- 0.8; and group IV, total 1.3 +/- 0.4 free 1.1 +/- 0.3 micromol/day). In contrast, the liver carnitine tended to increase when dietary intake was reduced (group I total 1.1 +/- 0.1, free 1.0 +/- 0.1; group II total 1.5 +/- 0.2, free 1.4 +/- 0.2; group III total 1.3 +/- 0.1, free 1.1 +/- 0.1; and group IV total 1.5 +/- 0.2, free 1.4 +/- 0.2 micromol/g dry wt). The highest liver carnitine concentrations were observed during the lowest dietary intake when also the serum and urine carnitine were lowest. We conclude that the amount of food intake has a direct impact on carnitine concentrations in the liver, serum, and urine while muscle carnitine concentration remains relatively stable despite wide variations in food intake.

Chronic Achilles paratenonitis in athletes: a histological and histochemical study.

Pathological alterations of chronic Achilles paratenonitis were studied histologically and histochemically in tissue samples obtained operatively from 16 athletes with this complaint and from 3 control patients. The activities of 11 different enzymes--lactate, succinate, malate, glucose-6-phosphate and glutamate dehydrogenases, lipoamide dehydrogenase and glutathione reductase (NADH2- and NADPH2-diaphorases), acid and alkaline phosphatases, phosphorylase and leucylaminopeptidase--were studied. Pathological findings were located diffusely around the tendon. A slight inflammatory cell reaction was found in all cases. The fatty areolar tissue was clearly thickened and edematous, and showed fibrinous exudations, widespread fat necrosis, considerable connective tissue proliferation and adhesion formation. The blood vessels showed profound degenerative and necrotizing changes. The thin membranes of the paratenon were clearly hypertrophied. Increased enzyme activities were mainly found in the fibroblasts, inflammatory cells and vascular walls. A moderate activity of lysosomal enzymes, an increased activity of enzymes of electron transport, anaerobic glycolysis, pentose phosphate shunt and decreased activity of those of aerobic energy metabolism were found. Simultaneously an increased amount of both neutral and acid mucopolysaccharides and a locally increased amount of elastic fibres were found in the inflamed paratenon. These results indicate that marked metabolic changes occur in paratenonitis, i.e. an increased catabolism and decreased oxygenation of the inflamed areas. The morphological alterations suggest that the gliding function of the paratenon may be impaired.

Perceptions of problematic events and quality of care among patients and parents after successful therapy of the child's malignant disease.

Fifty-three children (mean age 6.4 at diagnosis, 12.8 years at completion of questionnaires) identified as having acute lymphoblastic leukaemia (48) or non-Hodgkin lymphoma (5) during the 11-year period of 1976-1986 participated in the present study. Patients' and parents' perceptions of malignancy-related changes in significant relationships, of treatment-related problematic events, as well as of the quality of care provided during induction and maintenance-therapy were assessed using questionnaires. The results indicated mainly positive changes in significant relationships during the chemotherapy. However, concurrent stressful life events affected the relationships adversely. Alopecia (hair loss) was the most problematic disease-related event for the patient and the patient's anorexia for the parents. Patients' complaints were most often about the quality of care during induction, namely pain, fear and insufficient information. Parents' complaints were about the lack of continuity in the staff-patient relationship during maintenance-therapy.

Fine structural alterations in chronic Achilles paratenonitis in athletes.

The fine structural alterations in chronic Achilles paratenonitis were studied in tissue samples obtained from 14 athletes, who were operated on for this complaint and from 3 patients without any history of this disease. In the chronically inflamed paratendineal tissue mainly two types of cells were identified: classic fibroblasts with a smooth and rough endoplasmic reticulum and only a few mitochondria and lysosomes and myofibroblast-like cells with cytoplasmic microfilaments 5-6 nm in diameter, a rough endoplasmic reticulum, some mitochondrias and free ribosomes. These cells represented 19% of 471 studied non-inflammatory cells. In the extracellular space there was an increased amount of fibrils regarded as either type I or type III collagen as sign of tissue repair. Especially around the myofibroblastic cells a fine granular ground substance was found. The amount of ground substance was as a rule increased in pericellular space. Due to the capacity of contraction in healing tissue the myofibroblasts apparently have a role in the clinical symptoms of chronic Achilles paratenonitis.

Some biomechanical aspects of the foot and ankle in athletes with and without shin splints.

Thirteen adult male athletes (long-distance runners and orienteerers without foot problems) and 35 male athletes with shin splints were compared with respect to: 1) the position of the lower leg and the heel while standing, 2) the passive range of mobility in the subtalar joint, and 3) the angular displacement between the calcaneus and the midline of the lower leg (Achilles tendon angle) while running with bare feet on a treadmill. In standing, the two groups differed statistically significantly in the Achilles tendon angle, which values were greater in the shin splint group. With respect to passive mobility, the athletes with shin splints had significantly greater (P less than 0.05-0.01) angular displacement values in inversion, eversion, and in their sum than the control group. While running, the Achilles tendon angle of the shin splint group was significantly greater (P less than 0.01) at the heel strike. Further, the shin splints group had a significantly greater (P less than 0.01) angular displacement between the heel strike and the maximal everted position. The results suggest structural and functional differences in the feet and ankles between healthy athletes and those with shin splints.

Osgood-Schlatter's disease in adolescent athletes. Retrospective study of incidence and duration.

During the period of 1976 to 1981, a total of 412 young athletes contacted the Turku Sports Medical Research Unit's (TSMRU) Outpatient Sports Clinic with 586 complaints. These records included 68 athletes with Osgood-Schlatter's disease (OSD), who were initially prescribed an average of 2 months' rest from any physical activity causing pain. Symptoms of tibial tuberosity pain occurred first at the average age of 13.1 years. According to the retrospective questionnaire, the pain caused complete cessation of training for an average of 3.2 months, and the disease interfered with fully effective training for an average of 7.3 months. According to a retrospective questionnaire given to 389 students (191 girls and 198 boys), 50 (12.9%) had suffered from OSD. Nearly one-half of the students, 193 (49.6%), had been active in sports at the age of 13, and 41 (21.2%) of them had suffered from OSD. In those students who were not active in sports, the incidence was only nine (4.5%; P less than 0.001). The incidence (32%) was higher in the siblings of the OSD patients of TSMRU who were active in sports than in the corresponding student group (21.2%). In a group of 22 patients from the TSMRU who had suffered from Sever's disease (calcaneal apophysitis), the incidence of OSD (68%) was significantly higher than in students who were active in sports (P less than 0.001).

Chronic achilles paratenonitis. An immunohistologic study of fibronectin and fibrinogen.

Pathological alterations in chronic Achilles paratenonitis were studied histologically and using immunofluorescence techniques for fibronectin and fibrinogen in tissue samples obtained operatively from 11 athletes with this complaint and from 4 male cadavers serving as controls. The average duration of the paratenonitis was 20.4 months. The paratendineal fatty areolar tissue was clearly thickened and edematous, showing widespread fat necrosis and considerable connective tissue proliferation. The blood vessels were often obliterated and degenerated. Fibronectin and fibrinogen were commonly found in the proliferating connective tissue areas and in the vascular walls. Exudates rich in fibrinogen and fibronectin were seen in the inflamed paratendineal tissues, but not in the controls. The results indicate that increased vascular permeability and fibrin formation still persist in chronic Achilles paratenonitis and that marked obliterative and degenerative alterations of the blood vessels are frequent. The presence of fibronectin and fibrinogen points to an immature nature of scar tissue in chronic paratenonitis.

The role of recreational sport activity in Achilles tendon rupture. A clinical, pathoanatomical, and sociological study of 292 cases.

During the last few decades, the incidence of tendon ruptures has increased in civilized countries. Our material comprises 749 patients who had 832 tendon ruptures treated surgically between 1972 and 1985. There were no competitive athletes among the patients studied. There were 292 single ruptures of the Achilles tendon, 274 of the proximal biceps brachii, 113 of the extensor pollicis longus, and 70 of other tendons. Forty-eight patients had multiple ruptures and 35 patients had reruptures. Achilles tendon ruptures often occurred in recreational sports activities (59%), in contrast to other tendon ruptures (2%; P less than 0.001). The mean age for patients who had Achilles tendon rupture was 35.2 years and for patients with other ruptures, 50.7 years (P less than 0.001). There was a connection between the high incidence of blood group O and tendon ruptures (P less than 0.001). In cases of multiple ruptures and reruptures, the frequency of blood group O was 71%. Sixty-two point three percent of the patients with Achilles tendon rupture were professionals or white collar workers, which is markedly more than in the Hungarian population (12.7%; P less than 0.001). Two hundred and six Achilles tendon ruptures were studied histologically, and all cases displayed pathological alterations. The results indicate that complete rupture of the Achilles tendon is usually a sequel to a sedentary life-style and participation in sports activities.

Vascular density at the myotendinous junction of the rat gastrocnemius muscle after immobilization and remobilization.

Muscle injuries often occur at or near the myotendinous junction. Immobilization decreases the tensile strength of the myotendinous junction and predisposes it to strain injury. However, there are no data available on whether physical training or remobilization can lower the susceptibility of the myotendinous junction to strain injuries. We investigated the effects of three different remobilization programs (8 weeks) after immobilization (3 weeks) by evaluating the vascular density at the myotendinous junction of the rat gastrocnemius muscle. The myotendinous junctions had a portal system vascularity, or capillary-arteriole-capillary system, which probably protects the blood supply against pathologic conditions. The vascular density at the myotendinous junction decreased about 30% after immobilization (P < 0.001). After free cage remobilization for 8 weeks, the mean vascular density returned to the level of the controls. After progressively increasing running programs the vascular density was slightly higher in the immobilized myotendinous junction and about 50% higher than controls in the contralateral myotendinous junction (P < 0.001). The capacity of the vascular bed of the rat myotendinous junction to recover from immobilization atrophy seems to be good. Progressively increasing physical training improves the process of revascularization and probably protects an injured and immobilized muscle from reinjury.

The operative treatment of chronic calcaneal paratenonitis.

The conservative management of chronic calcaneal paratenonitis is time-consuming and often unsatisfactory. A new, safe and simple technique is described. The crural fascia on both sides of the tendon is incised and left open, adhesions around the tendon are trimmed away, the strongly hypertrophied portions of the paratenon are removed and mobilisation is begun immediately after operation. Between 1961 and 1978 201 such operations were performed on 182 patients 62 of whom were top-ranking Finnish athletes. Only five patients were not athletes. The results, including early return to full activity, were excellent in 169, good in 25 and poor in seven cases. After operation one of the patients gained an Olympic gold medal; others have attained international prominence.

The effect of tenotomy and immobilisation on intramuscular connective tissue. A morphometric and microscopic study in rat calf muscles.

The effect of tenotomy and of immobilisation in lengthened and shortened positions on the intramuscular connective tissue of the calf muscles of the rat was studied morphometrically and with a scanning electron microscope. Both tenotomy and immobilisation produced a marked increase in both the endomysial and the perimysial collagen networks, with a simultaneous decrease in intramuscular capillary density. The increase in connective tissue volume was more pronounced and occurred more rapidly in the soleus, which consists mainly of type I, slow-twitch fibres than in the gastrocnemius, which is mainly of type II, fast-twitch fibres. The relative volume of connective tissue increased in parallel with the duration of immobilisation or after tenotomy. There was slightly more increase after immobilisation in a shortened rather than in a lengthened position.