Biomedical subjects
Publications and source records attributed to L I Hansson.
The position of the femoral head in relation to the calcar femorale was analyzed from 120 radiographs of normal hips. A constant relationship was found, providing a method of calculating the normal position of the femoral head. The method was tested in 56 cases with physiolysis of the hip and was found to be useful in determining the degree of slipping in both adolescents and adults.
In a prospective randomized investigation, AO screws (53 cases) and hook-pins (57 cases) were used for femoral neck fracture fixation in 110 cases. The results of the one-week postoperative scintimetry and a four-month radiographic follow-up were analysed. The femoral head vitality according to scintimetry was similar in the two groups, whether undisplaced or displaced fractures. Within four months from the operation, six cases with screw fixation had been subjected to total hip arthroplasty while only one with hook-pins, all because of fracture redisplacement. However, at the four-month control, another more fracture operated on with screws and five more operated on with hook-pins were scheduled for hip arthroplasty. Thus, no difference between the two methods regarding postoperative femoral head vitality or complications in short term follow-up, was noted.
Human cadaveric femora were subjected to static and uniaxial dynamic load applied on the femoral head by a simulator. By two transducer-mounted aluminium rings attached to the bone, the static and the dynamic load causing an elastic deformation of 1 mm in the trochanteric region was assessed. A trochanteric fracture was then produced and stabilized by one of three fixation devices, after which the test was repeated. The unfractured femora had the most rigid appearance (static load, 25.9 KN/mm; dynamic load, 33.1 KN/mm). Of the fractured and stabilized specimens, the Jewett nail-plate gave the most rigid fixation (static load, 5.4 KN/mm; dynamic load, 11.5 KN/mm). The least rigid femora were those stabilized by the dynamic Nolok (static, 4.7 KN/mm; dynamic, 9.2 KN/mm) and Hansson (static, 3.2 KN/mm; dynamic 6.1 KN/mm) telescoping devices. Because of the viscoelastic properties of bone, the load applied in a hip simulator should be dynamic; otherwise, the ability of the device to withstand in vivo loading might be underestimated.
A 2-year follow-up regarding healing complications, such as redisplacement, nonunion, and segmental collapse of the femoral head, was performed in 306 patients operated on for femoral neck fracture and examined with 99mTechnetium-MDP scintimetry within 2 weeks postoperatively. Scintimetric evaluation was performed by selecting regions of interest over the femoral head on the fracture side and the intact side and by comparing the uptake. A femoral head ratio fractured/intact side thus was obtained. Of 199 patients with an intact femoral head uptake (ratio greater than or equal to 1.0), 181 showed no signs of healing complications at 2 years, whereas 18 had developed healing complications. Of 107 cases with a deficient femoral-head uptake (ratio less than 1.0), 96 had developed healing complications within 2 years from the operation, while 11 cases had no signs of radiographic complications. We conclude that 99mTc-MDP scintimetry performed within 2 weeks from femoral neck fracture can predict the outcome of the healing course with a prognostic accuracy of 91 per cent.
Growth during adolescence was analyzed in 40 children with slipped capital femoral epiphysis using the Infancy Childhood Puberty growth model. The advantage of this model is that reference values for height can be adjusted for the individual age at pubertal maturation. In both sexes an above average height was found before the onset of the pubertal growth spurt. However, the pubertal gain in height was less than normal, and at maturity the heights were only slightly above the reference mean values. Most of the children had their first hip symptoms during the period of increasing gain in height at the initial stage of the pubertal growth spurt. Both boys and girls were overweight before puberty and remained so during puberty and at maturity.
This work is based on 532 cases of physiolysis colli femoris (PCF) in southern Sweden from 1910 through 1982. The material was analyzed epidemiologically. Subsets were used for different investigations aimed at surveying the etiology of PCF, and long-term follow-ups were conducted after various methods of treatment. Finally, the short-term results after hook-pinning, a new device, were evaluated. After radiographic examination of anatomic specimens and normal hips, a method to diagnose and grade PCF was developed. The calcar femoral was found to be of constant shape and position and was used as a landmark to which the position of the femoral head was related. The advantage of this method is that it is easy to use and it is able to determine PCF also after growthplate closure. Epidemiologic analysis of the total material revealed large changes during the 20th century. The disease is more common in males than in females, but the male predominance has decreased from about 90 per cent to about 60 per cent during the period of investigation. Mean age at onset of slipping has decreased by about 3 years in males to 12.7 years and by about 1 year in females to 11.8 years. The incidence has followed a periodic pattern with peaks approximately every 20th year. The mean incidence was 6/10,000 in boys and 3/10,000 in girls. Boys living in the country have always been at higher risk than those living in cities. They were also at higher risk of sustaining bilateral slipping. In girls, there is a seasonal variation, with a higher incidence between May and August. The etiologic investigations dealt with hereditary, mechanical, and hormonal aspects. Radiographic examination revealed PCF in about 10 per cent of the first-degree relatives of 50 consecutive patients with PCF. One third of the families had 2 or more members with PCF. This familial accumulation is much higher than shown in earlier investigations based on questionnaires or clinical reports, and higher than expected from the incidence calculations. The growth analysis using the ICP model showed in both sexes an above average body height before puberty. However, at maturity the heights were almost normal, and accordingly the pubertal gain in height was lower than normal. Both the boys and the girls were markedly overweight before puberty and remained so at maturity. The ICP model accords with what is known about hormonal regulation of growth, and the growth abnormalities indicate a disturbed hormonal growth regulation.(ABSTRACT TRUNCATED AT 400 WORDS)
From 1966 to 1982 new concepts in the treatment of fresh femoral neck fractures were introduced at a university hospital in Sweden. These included immediate postoperative weight-bearing, a program with rehabilitation at home in collaboration with primary care, and an alteration of the treatment policy from primary hemiarthroplasty to a flanged nail and finally to hook pins. The total annual number of hospital days was reduced by about one-third during this period in spite of the fact that the annual number of femoral neck fractures doubled. Thus, the mean hospitalization time decreased from 44 to 16 days. The proportion of patients admitted from their own homes decreased from 80% to 52% during the 17-year period, and for these, the return rate home at discharge from the hospital increased from 44% to 75%. According to several reports from Scandinavia, the number of hip fractures will double in the next two decades. Ways of further reducing the hospitalization time, new techniques, and, if possible, methods of preventing hip fractures must be sought.
In 300 femoral neck fractures treated with hook-pin internal fixation, no perioperative mortality and no deep infection was seen. Eighty-four patients (28%) died within two years of the date of fracture. At two-year follow-up examination, 56 of 300 cases (19%) had developed radiographic healing complications, i.e., redisplacement, nonunion, or segmental femoral head collapse (26% of the survivors). Three of 85 undisplaced fractures (4%) developed segmental collapse (5% of the survivors) while among displaced fractures, radiographic evidence of malhealing was found in 53 of 215 cases (25%; 35% of survivors) at two-year follow-up examination. In the total series, secondary hip arthroplasty was performed in 34 cases (11%). Atraumatic reduction and internal fixation are recommended as primary treatment in femoral neck fractures.
Fifty-seven patients, all over the age of 64, with femoral neck fracture were randomized to receive epidural or halothane anesthesia to see if the anesthetic technique influenced the incidence of postoperative confusion. All patients were lucid on admission. Using the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM-III) as criteria for confusion, we found that 44% of the patients developed confusion that correlated closely to a history of mental depression (P less than 0.01) and to the use of drugs with anticholinergic effect (P less than 0.005). There was no difference in the incidence of confusion between the two anesthetic groups. In patients given halothane, however, early postoperative hypoxemia was associated with confusion (P less than 0.05). Patients with confusion had significantly more postoperative complications and almost four times longer hospitalization times. It is concluded that anticholinergic medication and a history of mental depression are predominant risk factors for development of postoperative confusion and in this respect are more important than the anesthetic technique.
Seventy-two patients treated with closed reduction and hip spica for slipped capital femoral epiphysis (physiolysis colli femoris; PCF) were evaluated by questionnaire 25 to 66 years after primary treatment. Fifty-seven cases were examined with the use of clinical and radiographic methods. Pain and restricted hip function were obvious in most patients. In 25 of 72, an operation had been done in adult life for coxarthrosis. In a previously investigated group of PCF patients not actively treated, only two of 49 had had surgical treatment of coxarthrosis. Thus the results of closed reduction and hip spica are unfavorable, compared with those of nontreated cases. The results suggest a harmful influence of both reduction and hip spica.
Twenty patients were examined by standard radiography and roentgen stereophotogrammetric analysis (RSA) during a two-year period after total hip arthroplasty. Eleven of the acetabular components migrated cranially and three femoral components migrated distally. This migration was most rapid during the first four months after operation. Our findings support the possibility that mechanical loosening is initiated by thermal injury during polymerisation of the cement; the less frequent migration of the metallic femoral component compared with the polyethylene acetabular component may be because the metal acts as a heat sink. Standard radiographs were inadequate for assessment of early mechanical loosening, whereas RSA could reveal migration within four months of the arthroplasty.
A male, his son, and grandson all had a slipped capital femoral epiphysis (physiolysis colli femoris--PCF). The importance of inheritance in PCF is discussed.
A radiographic investigation was undertaken to determine whether an increased interest in femoral neck fractures improved the operative result. In 1977, all femoral neck fractures were operated on by any of 30 surgeons of the orthopedic department, but in 1981 all fractures were operated on by one of six specially devoted surgeons. Preoperative fracture classification was performed with three parameters and proved equal in the 1977 and 1981 groups of 105 and 114 fractures, respectively. The quality of fracture reduction, determined with four parameters, was improved somewhat. The position of the nail(s), also determined with four parameters, improved considerably. The technical result was better in Garden IV fractures than in Garden III fractures. An increased interest in femoral neck fracture treatment improved reduction and fixation.
In 50 consecutive cases of slipped capital femoral epiphysis (SCFE) from 49 families, the heredity was analyzed by radiographic examination of the first-degree relatives and by interview regarding the second-degree relatives. In four of the 49 families, SCFE was obvious in one or more first-degree relatives; and in another 13 families (14 relatives), radiographic signs of SCFE were found besides the primary case. The familial accumulation was much higher than expected from incidence studies, indicating a hereditary factor in the etiology.
Opinions differ concerning the treatment of choice for severe slipped capital femoral epiphysis, probably due to the lack of long-term follow-up evaluations on the different methods of treatment. A series of 33 patients with severe slipped capital femoral epiphysis, treated per primam with wedge osteotomy of the femoral neck, were radiographically and clinically reexamined an average of 28 years (range, 16-32 years) after the operation. Segmental collapse and/or chondrolysis developed in ten patients. Nine of these patients were available for reexamination and all had severe arthrosis with poor function. Arthrosis developed in nine of the 19 patients without signs of segmental collapse or chondrolysis; these patients had a satisfactory joint function. This series was compared with another series (from the same orthopedic departments) of patients with severe slip without any primary treatment. The long-term results in these two groups were similar; consequently, the value of realignment by wedge osteotomy of the femoral neck is questionable.
Bone growth and remodelling was studied in rats after injection of growth hormone, melanocyte-stimulating hormone (alpha-MSH), and cortisone daily for 20 days with tetracycline as intravital marker. An increase of both longitudinal and periosteal growth with growth hormone was found. A decrease of both was found after a high cortisone dose. Lower cortisone doses seem to have stimulated periosteal growth. No effect of alpha-MSH was found.
In 25 cases with 29 slipped capital femoral epiphyses, treated with bilateral pinning, tetracycline was administrated preoperatively. Biopsies from the femoral head and the trochanteric region were analyzed by fluorescence microscopy. All had normal tetracycline labeling except the only patient with an acute severe slip.
Contrast arthrography, radionuclide arthrography, scintigraphy and roentgen stereophotogrammetric analysis (RSA) were used to detect mechanical loosening in 14 painful total hip replacements. All prosthetic components unstable by RSA, or with abnormal arthrogram, or with increased scintigraphic activity, or loose at revision were migrating, but no non-migrating components demonstrated any of these signs of loosening. Our findings indicate that mechanical loosening should be defined as migration.