Muscle tissue lactate after maximal exercise in man.
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Biopsy↗
Biomedical subjects
J Karlsson
Publications and source records attributed to J Karlsson.
Lactate dehydrogenase activity in muscle after prolonged severe exercise in man.
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Biopsy↗
Training of the oxygen transport system in man.
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Adult↗
Donor-site morbidity and anterior knee problems after anterior cruciate ligament reconstruction using autografts.
The authors review the current knowledge on donor site-related problems after using different types of autografts for anterior cruciate ligament (ACL) reconstruction and make recommendations on minimizing late donor-site problems. Postoperative donor-site morbidity and anterior knee pain following ACL surgery may result in substantial impairment for patients. The selection of graft, surgical technique, and rehabilitation program can affect the severity of pain that patients experience. The loss or disturbance of anterior sensitivity caused by intraoperative injury to the infrapatellar nerve(s) in conjunction with patellar tendon harvest is correlated with donor-site discomfort and an inability to kneel and knee-walk. The patellar tendon at the donor site has significant clinical, radiographic, and histologic abnormalities 2 years after harvest of its central third. Donor-site discomfort correlates poorly with radiographic and histologic findings after the use of patellar tendon autografts. The use of hamstring tendon autografts appears to cause less postoperative donor-site morbidity and anterior knee problems than the use of patellar tendon autografts. There also appears to be a regrowth of the hamstring tendons within 2 years of the harvesting procedure. There is little known about the effect on the donor site of harvesting fascia lata and quadriceps tendon autografts. Efforts should be made to spare the infrapatellar nerve(s) during ACL reconstruction using patellar tendon autografts. Reharvesting the patellar tendon cannot be recommended due to significant clinical, radiographic, and histologic abnormalities 2 years after harvesting its central third. It is important to regain full range of motion and strength after the use of any type of autograft to avoid future anterior knee problems. If randomized controlled trials show that the long-term laxity measurements following ACL reconstruction using hamstring tendon autografts are equal to those of patellar tendon autografts, we recommend the use of hamstring tendon autografts because there are fewer donor-site problems.
Anterior Cruciate Ligament↗
Comparison of an arthroscopic and an open procedure for posttraumatic instability of the shoulder: a prospective, randomized multicenter study.
From 1993 through 1996, a multicenter study was conducted on the surgical treatment of patients with posttraumatic recurrent anterior shoulder dislocations. Fifty-six patients (40 men, 16 women; mean age 26 years [range 18-51 years]), were evaluated with shoulder arthroscopy. If a Bankart lesion was present, the patients were randomly allocated to either an arthroscopic reconstruction with the use of biodegradable tacks or an open reconstruction with suture anchors. The postoperative rehabilitation protocol for the two groups was identical. In all patients, the range of shoulder motion, stability, and the Constant and Rowe scores were evaluated at 3, 12, and 24 months postoperatively. Thirty patients were surgically treated with the arthroscopic technique and 26 patients with the open technique. In the arthroscopic group, there were recurrences in 7 (23%) of 30 patients at a mean of 13 months (range 5 to 21 months) after surgery. All patients with stable shoulders had a negative apprehension test result. In the open group, there were recurrences in 3 (12%) of 26 patients at a mean of 10 months (range 2 to 23 months) after surgery (P = not significant). In the arthroscopic group, 2 patients had new traumatic redislocations, whereas 1 patient redislocated during an epileptic seizure. In the open group, 1 traumatic redislocation occurred. The 2-year results in this study demonstrate a large number of redislocations after reconstruction, even in the open surgery group. Patient noncompliance with the rehabilitation protocol and predisposing disease may partially explain these results. A tendency was seen toward more redislocations in the arthroscopic group, which emphasizes the importance of correct patient selection and careful surgical technique in the difficult surgical procedure.
Adolescent↗
A radiographic and histologic evaluation of the patellar tendon after harvesting its central third.
Nineteen consecutive patients undergoing anterior cruciate ligament reconstruction using the central third of the ipsilateral patellar tendon were included in the study. Serial magnetic resonance images revealed that the donor-site gap in the tendon decreased with time (mean follow-up, 26 months). The thickness was significantly increased compared with the intact contralateral patellar tendon, regardless of when the magnetic resonance imaging was performed. Ultrasonography showed the same findings at a mean follow-up of 26 months. Histologic evaluation of the repair tissue in the central part of the tendon, as well as the tissue in the peripheral part of the patellar tendon at the donor site, revealed a significant increase in cellularity and vascularity as compared with normal control tendons. Thus, 2 years after the harvesting procedure, the patellar tendon displayed significant radiographic and histologic abnormalities. On the basis of these findings, reharvest of the patellar tendon, at least up to 2 years after primary harvest, cannot be recommended.
Adolescent↗
Comparison of traditional and subcutaneous patellar tendon harvest. A prospective study of donor site-related problems after anterior cruciate ligament reconstruction using different graft harvesting techniques.
Our goal was to compare the results after anterior cruciate ligament reconstruction using either the traditional one-incision or the subcutaneous two-incision technique to harvest the central third of the patellar tendon, particularly concerning disturbances in anterior knee sensitivity and the patient's ability to walk on his or her knees. One surgeon performed anterior cruciate ligament reconstruction on 124 patients with unilateral ruptures and no history of previous incisions in the anterior knee region. The traditional one-incision graft harvesting technique was used in 58 patients and the subcutaneous two-incision technique was used in 66 patients. At 2 years, the International Knee Documentation Committee classification, Lysholm score, arthrometry side-to-side difference, and single-legged hop test showed no significant differences between groups. The area of insensitivity was a median of 24 cm2 in the traditional harvest group and 0 cm2 in the subcutaneous harvest group. The patients with subcutaneous harvest had a tendency toward fewer problems during walking on their knees than did the patients with traditional harvest. Our conclusion is that the subcutaneous two-incision graft harvesting technique caused less disturbance in anterior knee sensitivity and a tendency of less discomfort during walking on one's knees than the traditional one-incision technique.
Adolescent↗
Comparison of open and arthroscopic stabilization for recurrent shoulder dislocation in patients with a Bankart lesion.
We performed a prospective study of 117 patients (119 shoulders) with symptomatic, recurrent anterior posttraumatic shoulder instability to compare open versus arthroscopic reconstruction. Arthroscopic reconstructions (N = 66) were performed using bioabsorbable tacks (Suretac fixators), whereas open reconstructions (N = 53) were performed with suture anchors. All of the patients had a Bankart lesion. Independent observers examined 108 of the 119 shoulders (91%) at a median follow-up period of 28 months (range, 24 to 63) for the arthroscopic group and 36 months (range, 24 to 63) for the open group. The recurrence rate, including both dislocations and subluxations, was 9 of 60 (15%) in the arthroscopic group, compared with 5 of 48 (10%) in the open group. At follow-up, the Rowe score was 93 points (range, 39 to 100) and the Constant score was 91 points (range, 56 to 100) in the arthroscopic group, compared with 89 points (range, 53 to 100 and 57 to 100 for the Rowe and Constant scores, respectively) for both scores in the open group. The only significant difference was in external rotation in abduction, which was 90 degrees (range, 50 degrees to 135 degrees) in the arthroscopic group and 80 degrees (range, 25 degrees to 115 degrees) in the open group. Both methods produced stable and well-functioning shoulders in the majority of patients.
Adolescent↗
Surgical treatment of chronic lateral instability of the ankle joint. A new procedure.
Sixty patients with chronic lateral functional and mechanical instability of the ankle joint were treated with shortening and reinsertion of the lateral ankle ligaments. All patients were followed prospectively for 2 to 5 years (mean, 3 years 6 months). We found the functional results to be excellent or good in 53 patients (88%). Patients with unsatisfactory results had either generalized joint hypermobility or long-standing ligament insufficiency. Anterior talar translation (ATT) and talar tilt (TT) were measured radiologically on standardized radiographs. Patients with excellent and good functional results had better mechanical stability, both ATT and TT, than those with fair and poor functional results. A good correlation was found between clinical, functional, and radiological results. In conclusion we found that reconstruction of the ankle stability by shortening and reinsertion of the lateral ankle ligaments is a safe and simple method and is a good alternative to other more complex methods of ligament reconstruction. The method should, however, be used with great care in patients with generalized joint hypermobility or in patients with long-standing ligament insufficiency.
Adolescent↗
Partial rupture of the patellar ligament. Results after operative treatment.
Partial rupture of the patellar ligament, also known as jumper's knee, is defined as a repetitive overload lesion at the bone-ligament junction at the lower patellar pole. It is found mainly in athletes and is caused either by microruptures or partial macroruptures of the proximal part of the ligament. The abnormal anatomical lesion is focal degeneration, microruptures and macroruptures, and devitalized tissue at the insertion of the patellar ligament. Proliferation and neovascularization are often found, as well as degeneration and incomplete tissue healing. Surgical treatment is indicated only if a prolonged and well-supervised conservative treatment program fails. We operated on 78 patients with jumper's knee, by carefully removing the abnormal tissue from the ligament. At follow-up examination, 71 of 78 patients had excellent or good functional results and complete resumption of sports activities. Objective measurements of thigh muscle strength using a Cybex II dynamometer correlated with the functional results at a low angular velocity.
Adolescent↗
The effect of external ankle support in chronic lateral ankle joint instability. An electromyographic study.
We examined the effect of ankle taping on ankle joint stability by measuring mechanical stability using standardized stress radiographs. Anterior talar translation and talar tilt, both with and without ankle tape, were examined. The reduction of anterior talar translation and talar tilt with tape as compared to without tape was insignificant. The reaction time of the peroneus muscles was measured by electromyographic signal after a simulated ankle sprain on a tilting trapdoor. The reaction time was significantly slower in the unstable ankles of 20 athletes with unilateral ankle instability than in the stable contralateral ankles. With tape, the reaction time was significantly shortened, although not back to normal. The greatest improvement in reaction time was achieved in ankles with the highest degree of mechanical instability. Thus, the mechanism behind the function of ankle tape may be to restrict the extremes of ankle motion and to help shorten the reaction time of the peroneus muscles by affecting the proprioceptive function of the ankle.
Adult↗
Partial rupture of the patellar ligament.
Eighty-one patients with 91 partial ruptures of the patellar ligament verified by ultrasonography were treated conservatively with a standardized training program based on the principles of eccentric loading. The partial ruptures were quantified by measuring the length of the hypoechoic lesion using ultrasonography in longitudinal projection. The partial ruptures were then divided into three groups: Grade I (less than 10 mm), Grade II (10 to 20 mm), and Grade III (greater than 20 mm). The results after the training program were significantly better in Grade I ruptures than in Grades II and III. The overall need for surgery was 29.6%: highest in Grade III ruptures (38.5%) and lowest in Grade I ruptures (6.6%). The outcome of conservative management, as well as the need for surgery of partial ruptures of the patellar ligament, may to some extent be predicted by the use of ultrasonography.
Adolescent↗
Ultrasonography of chronic tendon injuries in the groin.
Ultrasonography was used in the diagnosis of 36 patients with chronic groin pain localized to the tendons of the rectus abdominis, rectus femoris, adductor muscles, hamstring muscles, and the gluteal muscles. Abnormal findings, such as focal sonolucent areas and discontinuity of tendon fibers, that are indicative of nonhealed partial ruptures were found in 28 patients. These findings differed clearly from the asymptomatic contralateral side, which was used for comparison. The abnormalities were located in three different sites: at the tendon insertion, within the tendon, and at the tendomuscular junction. Ten patients were treated surgically and the findings at surgery correlated well with the ultrasonographic findings of partial tendon tears: 9 were true-positive and 1 was a true-negative. Ultrasonography appears to be a valuable method in the diagnosis of chronic groin pain.
Adolescent↗
Comparison of two anatomic reconstructions for chronic lateral instability of the ankle joint.
Two anatomic reconstructions for correction of chronic lateral ankle joint instability were compared. In a prospective, randomized study, 60 patients were allocated to one of two treatment groups: reconstruction of the ligaments as described by Karlsson et al. (Group I) or with the modification of the Broström procedure as described by Gould et al. (Group II). The functional results were evaluated with a scoring scale, and the mechanical stability with standardized stress radiographs. The minimum follow-up period was 2 years. The functional results were satisfactory in 27 of 30 (90%) patients in Group I and 25 of 30 (83%) in Group II. There was no significant difference between the groups regarding mechanical stability. The mean anterior talar translation in Group I was 7.1 mm (range, 4 to 10) at followup, compared with 6.7 mm (range, 3 to 9) in Group II. The corresponding values for talar tilt were 4.9 degrees (range, 0 degree to 8 degrees) in Group I and 4.4 degrees (range, 0 degree to 8 degrees) in Group II. The duration of operation time was significantly longer in Group II and surgical complications were more frequent, probably due to the more extensive surgical exposure. This study showed that the majority of patients with chronic ankle instability can be successfully treated with anatomic reconstruction of the lateral ankle ligaments. Mechanical stability was restored with both methods.
Activities of Daily Living↗
Ipsi- or contralateral patellar tendon graft in anterior cruciate ligament revision surgery. A comparison of two methods.
Twenty-four patients who underwent anterior cruciate ligament revision surgery were studied postoperatively (12 with reharvested ipsilateral patellar tendon grafts and 12 with contralateral patellar tendon grafts). For comparison purposes, 12 matched patients with primary anterior cruciate ligament reconstruction, who had been operated on using the same technique by the same surgeons, were chosen. The median time since the first reconstruction was 57 months (range, 15 to 132) in the ipsilateral tendon group and 54 months (range, 20 to 108) in the contralateral tendon group. Follow-up examination showed that there were no significant differences in total KT-1000 arthrometer side-to-side measurements between the groups, but the Lysholm score was higher for patients with contralateral tendon grafts than for patients with ipsilateral grafts. Only two patients with ipsilateral grafts were classified as having excellent or good results. Functional testing outcomes were similar for all groups, and magnetic resonance imaging screening showed no differences between the reharvest and primary harvest groups in terms of length, width, thickness, or donor site gap of the patellar tendon. However, there were two major complications in the group with revision surgery with the ipsilateral reharvested patellar tendon. Reharvesting the ipsilateral patellar tendon resulted in lower functional scores and a higher rate of complications than revision with the contralateral patellar tendon or primary anterior cruciate ligament reconstruction.
Adult↗
Pretreatment with MK-801 or the lazaroid U-83836E does not enhance striatal graft survival.
A large proportion of grafted striatal neurons die, and mechanisms by which they succumb may involve excitotoxicity and oxidative stress. We investigated the effects of pretreatment of the graft tissue with the N-methyl-D-aspartate (NMDA) receptor antagonist (+)dizocilpine hydrogen maleate (MK-801) and lipid peroxidation inhibitor lazaroid U-83836E on the survival of transplanted striatal neurons. Neither compound increased the survival of grafts, suggesting that NMDA-related excitotoxicity or oxidative stress may not be primary mediators of cell death in striatal grafts.
Animals↗
Improving the survival of grafted dopaminergic neurons: a review over current approaches.
Neural transplantation is developing into a therapeutic alternative in Parkinson's disease. A major limiting factor is that only 3-20% of grafted dopamine neurons survive the procedure. Recent advances regarding how and when the neurons die indicate that events preceding actual tissue implantation and during the first week thereafter are crucial, and that apoptosis plays a pivotal role. Triggers that may initiate neuronal death in grafts include donor tissue hypoxia and hypoglycemia, mechanical trauma, free radicals, growth factor deprivation, and excessive extracellular concentrations of excitatory amino acids in the host brain. Four distinct phases during grafting that can involve cell death have been identified: retrieval of the embryo; dissection and preparation of the donor tissue; implantation procedure followed by the immediate period after graft injection; and later stages of graft maturation. During these phases, cell death processes involving free radicals and caspase activation (leading to apoptosis) may be triggered, possibly involving an increase in intracellular calcium. We review different approaches that reduce cell death and increase survival of grafted neurons, typically by a factor of 2-4. For example, changes in transplantation procedure such as improved media and implantation technique can be beneficial. Calcium channel antagonists such as nimodipine and flunarizine improve nigral graft survival. Agents that counteract oxidative stress and its consequences, such as superoxide dismutase overexpression, and lazaroids can significantly increase the survival of transplanted dopamine neurons. Also, the inhibition of apoptosis by a caspase inhibitor has marked positive effects. Finally, basic fibroblast growth factor and members of the transforming growth factor-beta superfamily, such as glial cell line-derived neurotrophic factor, significantly improve the outcome of nigral transplants. These recent advances provide hope for improved survival of transplanted neurons in patients with Parkinson's disease, reducing the need for human embryonic donor tissue and increasing the likelihood of a successful outcome.
Animals↗
Addition of lateral ganglionic eminence to rat mesencephalic grafts affects fiber outgrowth but does not enhance function.
Addition of embryonic striatal tissue, usually as a combination of the lateral and medial ganglionic eminences, to intrastriatal mesencephalic grafts has previously been reported to enhance recovery of drug-induced rotational behavior in the host and to modify axonal fiber outgrowth from the grafted dopaminergic neurons. This study investigated the effects of adding (cografting) either lateral or medial ganglionic eminence tissue to embryonic mesencephalic grafts implanted intrastriatally, in rats with unilateral 6-hydroxydopamine lesions. The cografts did not exhibit increased survival or cell size of dopaminergic neurons when compared to transplants of mesencephalic tissue alone. Neither did recipients of cografts exhibit any enhancement of graft-induced recovery of function, when tested for drug-induced rotational behavior or forelimb function in the staircase test. However, cografts containing lateral ganglionic eminence displayed patches of dense tyrosine hydroxylase-immunoreactive fibers within the graft tissue. These patches largely coincided with patches in adjacent stained sections, which were rich in immunostaining for the striatal-specific marker dopamine- and cyclic AMP-regulated phosphoprotein-32 (DARPP-32). Such patches were not present in rats receiving cografts containing medial ganglionic eminence or mesencephalic tissue alone. Thus, it seems that the grafted dopaminergic neurons preferentially grow into the areas of the transplants containing lateral ganglionic eminence tissue. In summary, the results suggest that embryonic lateral ganglionic eminence exerts trophic effects on the outgrowth of dopaminergic axons, but does not enhance the behavioral effects of grafted dopaminergic neurons.
Animals↗