Primary osteoarthritis of the hip: etiology and epidemiology.

Primary osteoarthritis (OA) of the hip has a distinct etiology and epidemiology compared with other types of arthropathy in the hip joint. Arthritis of the hip can be secondary to conditions such as osteonecrosis, trauma, sepsis, or rheumatoid arthritis. Certain conditions, such as congenital hip disease and slipped capital femoral epiphysis, involve predisposing anatomic abnormalities; in such cases, the term "secondary OA" is used. When either an anatomic abnormality cannot be determined or other specific causative entities are not identified, primary OA is the diagnosis of exclusion. The prevalence of hip OA is about 3% to 6% in the Caucasian population and has not changed in the past four decades. In contrast, studies in Asian, black, and East Indian populations indicate a very low prevalence of hip OA. Statistics on patients who underwent total hip replacement for primary OA in San Francisco and Hawaii demonstrate a virtual absence of the condition in Asians and low rates in the black and Hispanic populations. Family studies from Sweden, Britain, and the United States show increased rates of hip OA in first-degree relatives of the index patient when compared with the normal population. Occupations requiring heavy lifting, farming, and elite sports activity are associated with increased rates of hip OA. The low prevalence of hip OA in Asian and black populations in their native countries; the low incidence of total joint replacement for primary OA in Asian, black, and Hispanic populations in North America; and the familial association of hip OA in Caucasians all suggest that genetic factors may be involved in the occurrence of this disease.

Total hip replacement rates are higher among Caucasians than Asians in Hawaii.

The etiology of hip osteoarthritis remains unknown but may involve genetic or lifestyle factors. Most cases of total hip replacement are performed because of osteoarthritis. To examine possible ethnic differences, hospital records in Hawaii from 1985 to 1989 were reviewed. Preoperative radiographs were reviewed for a subset of patients to ascertain the reason for total hip replacement. Osteoarthritis accounted for a greater percentage of total hip replacements among whites (59% for women and 66% for men) than among Japanese (36% of women and 30% of men). The incidence of total hip replacement for whites was three to 25 times greater than that of other ethnic groups (Japanese, Chinese, Filipino, and Hawaiians). For example, the risk of total hip replacement for white women 40 years to 84 years of age was 4.4%, compared with 1.1% for Japanese women and 1.7% for Chinese women of the same age group. Compared with published data, the incidence was similar for Chinese in Hawaii and San Francisco; however; whites in Hawaii had a total hip replacement incidence less than half that of whites in San Francisco. Lifestyle differences might account for the lower incidence of total hip replacement for whites in Hawaii, compared with those in San Francisco. The lower incidence among Asians suggests a possible genetic basis for osteoarthritis.

Extreme variations in racial rates of total hip arthroplasty for primary coxarthrosis: a population-based study in San Francisco.

OBJECTIVES: To compare the incidence of all total hip arthroplasty, and total hip arthroplasty for primary coxarthrosis, among the Asian, black, Hispanic, and white populations living in one locale. METHODS: We identified all San Francisco residents who underwent total hip replacements (THR) in the 17 hospitals for adults within or near San Francisco County during a five year period. Preoperative pelvic radiographs were read without prior knowledge of the gender or race of the subject, to diagnose the specific hip diseases. Age standardised THR incidence by race and gender was determined, as was the comparative THR incidence for specific diagnosis (primary and secondary osteoarthritis). RESULTS: The greatest annual rate of total hip replacement occurred in white women (97 per 100,000 population), followed by white men, black women, black men, Hispanic women, and Hispanic men. The smallest numbers were found in Asians, whose THR rate was 10% that of whites. A primary coxarthrosis diagnosis was greatest among white subjects (66%), followed by black subjects (54%), Hispanics (53%), and Asians (28%). Age standardised THR rates for primary coxarthrosis per 100,000 population were likewise greatest among whites (43.0) and least among Asians (1.3 for Chinese). Mean age of patients undergoing THR for primary coxarthrosis was 70 years for white subjects and almost a decade younger in all other groups. CONCLUSIONS: THR rates are much lower for Asians, Hispanics, and black subjects than for the white population living in San Francisco. The low rates of total hip arthroplasty in the non-white groups was related to the much lower incidence of THR for primary coxarthrosis among non-whites than among whites. The racial distribution of primary coxarthrosis among patients who underwent THR is consistent with distribution patterns reported internationally.

Use of parenteral prophylactic antibiotics in clean orthopaedic surgery. A review of the literature.

Parenteral prophylactic antibiotics are now a routine part of most clean orthopaedic procedures since so many animal and clinical studies have shown a reduced infection rate with their use. First-generation cephalosporins are theoretically the preferred agents, and the pharmacokinetics of Cefazolin make it the drug of choice. It is imperative that an antibiotic be given on the induction of anesthesia or at least ten minutes before inflation of a tourniquet. Based on evidence in the current literature, 24 hours of postoperative coverage appears to be adequate.

Osteoarthrosis and congenital dysplasia of the hip in family members of children who have congenital dysplasia of the hip.

Four hundred and eight siblings, parents, and grandparents of seventy-eight children from the New England area who had congenital dysplasia of the hip were evaluated, by clinical examination and by measurements of the acetabulum on pelvic radiographs, for the signs and sequelae of congenital dysplasia of the hip. Six siblings and four mothers (representing seven of seventy-eight families) had been diagnosed with congenital dysplasia of the hip during childhood. The other ninety-one siblings were asymptomatic and had no radiographic evidence of dysplasia of the hip. In the adults in these families, acetabular coverage (as measured by the center-edge angle of Wiberg) was no different from that in the control subjects. There was no difference between the study group and the control subjects in the prevalence of osteoarthrosis of the hip or of osteoarthrosis that could be considered secondary to congenital dysplasia of the hip. The results indicate that children born to families that have a history of congenital dysplasia of the hip have a greater prevalence of this problem compared with the general population, but also that examinations of the hip in newborns are effective in detecting congenital dysplasia of the hip in such families. The greater prevalence of congenital disease of the hip among the siblings and mothers in these families is consistent with a multifactorial inheritance. The fact that acetabular development in the family members who did not have congenital dysplasia of the hip was no different from that in the control subjects suggests that acetabular dysplasia, rather than being an inherited abnormality, is secondary to subluxation or dislocation.

The University of California Biomechanics Laboratory four-bar polycentric knee linkage. A clinical trial in 20 active above-knee amputees.

A four-bar polycentric prosthetic knee linkage developed by the University of California Biomechanics Laboratory (UCBL) was tested clinically in 20 active veteran above-knee amputees. The mean follow-up period was 12.3 months. At final follow-up evaluation, positive subjective responses were reported by 80% of the amputees. More than one-third reported that the device was superior to any that they had used previously. Almost all subjects found that prior levels of daily activity and the ability to perform specific activities were maintained or enhanced. The increase in knee flexion afforded by the mechanism was found to be an advantage. There was no significant change in various fundamental gait parameters. Problems caused by excessive wear of anodized aluminum linkage pins and by air leaks in the pneumatic swing-phase control unit were corrected easily. These preliminary results encourage further clinical application and study of the UCBL four-bar polycentric knee.

Diseases of the hip. A comparative study of Japanese Oriental and American white patients.

Pelvic radiographs of 200 consecutive Japanese Oriental patients who were admitted for hip surgery at the Hospital of Kobe University in Japan were compared with those of 199 consecutive American white patients who were admitted for the same purpose to a New England hospital over a similar four and a half-year period between 1972 and 1976. One hundred and fifty-three Japanese Oriental and 157 American white patients had either primary or secondary osteoarthritis. The remainder had other types of hip pathology, such as avascular necrosis, rheumatoid arthritis, and ankylosing spondylitis. The radiographs of five Japanese Oriental and seven American white patients showed evidence of previous Legg-Calvé-Perthes disease, coxa vara, or slipped capital femoral epiphysis. With only two exceptions, the osteoarthritis in the remainder of the Japanese Oriental patients was secondary, caused by antecedent congenital hip disease: twenty-eight had one or two congenitally dislocated hips, ninety-two had acetabular dysplasia, and twenty-six had superolateral osteoarthritis. In contrast, only nine of the American white patients clearly had a diagnosis of acetabular dysplasia, and twenty-six had superolateral osteoarthritis. Twenty-one American white men had a femoral head-tilt deformity. Among the Americans, the largest group (sixty-five patients) had superomedial osteoarthritis. Nine had non-rheumatoid protrusio acetabuli and twenty had axillary or concentric osteoarthritic involvement. The majority of American white patients, therefore, had a type of osteoarthritis that was not seen in the Japanese Oriental patients.(ABSTRACT TRUNCATED AT 250 WORDS)

CT in low back pain syndrome.

CT has become the imaging modality of choice for diagnosing the specific cause of low back pain syndrome. This article describes and illustrates those abnormalities commonly associated with low back pain: disk herniation, spinal stenoses, facet joint abnormalities, spondylosis, inflammatory conditions of the lumbar spine, and sacroiliitis.

Brachial neuritis.

Brachial neuritis is an unusual syndrome of unknown etiology that can be confused with other causes of pain or weakness, or both, of the shoulder and arm. It is important to distinguish this disorder because of its dramatic symptoms and relatively good prognosis. Sharp pain, usually in the elbow or shoulder, marks the onset of brachial neuritis, but is relatively short-lived. Weakness generally occurs as the pain is subsiding and most frequently involves the deltoid, spinati, serratus anterior, biceps, and triceps. Paresthesias, atrophy, and sensory loss are inconstant features. Electromyographic findings of fibrillation potentials and positive waves characteristically are found in a pattern indicating combined nerve-root and peripheral nerve involvement. Electromyography more frequently than clinical examination shows that the lesion is bilateral, and also is of both diagnostic and prognostic value. Other laboratory studies serve only to exclude other causes of shoulder pain. The clinical course is variable, but in 90 per cent of patients complete recovery occurs within three years. Recurrences are uncommon.

Percutaneous lumbar diskectomy using a new aspiration probe: porcine and cadaver model.

A method of percutaneous aspiration of the nucleus pulposus of lumbar disks is described as performed in four pigs and three cadavers. Through a lateral oblique percutaneous approach, 80-100% of the nucleus pulposus was removed in each of the pigs; approximately 30% of the cadaver disk was removed. A unique aspiration probe and the introducing set as well as the technique are described. The implications for clinical use in patients are discussed. We believe this technique may be an alternative to both surgical diskectomies and chymopapain injection in the treatment of herniated disk disease of the lumbar spine.

Subjective evaluation of the UCBL polycentric knee linkage by active above knee amputees. A prospective trial.

In this study 20 active male above knee amputees were fitted with prostheses incorporating prototype UCBL four-bar polycentric knee units. The subjective responses of the amputees were evaluated in a prospective fashion. Additional information concerning the short-term durability and mechanical behavior of the device is presented. The average followup was 12.3 months. Sixteen of the 20 subjects felt that they benefited from the device, and seven of these stated that the research prosthesis was superior to all previous devices that they had used. Four subjects stated that they had received little or no benefit from the research limb. Previous levels of function and the ease of performance of specific activities were maintained or enhanced in almost all subjects. Most subjects felt that the ease of walking on inclines was improved, and found the increase in knee flexion afforded by the mechanism to be an advantage. Early in the study, problems were encountered due to air leaks in the pneumatic swing-phase control units and to excessive wear of the aluminum linkage pins. These problems were corrected easily, and the devices were found to function well during the remainder of the study. Given the encouraging results from this preliminary clinical trial, we conclude that further study and clinical application of the UCBL four-bar polycentric knee are indicated.

Evaluation of problems and needs of veteran lower-limb amputees in the San Francisco Bay Area during the period 1977-1980.

From 1977 through 1980, 251 veterans from the San Francisco Bay Area received permanent lower-extremity prostheses at the two local Veterans Administration hospitals. For a survey, 213 of the 251 were contacted and 179 of them (84%) responded to written or telephone questionnaires concerning their prosthetic problems and complaints and their recommendations regarding prosthetic care. Seventy-four percent of the patients were traumatic amputees and 23 percent were dysvascular amputees. Eighty-six percent of the traumatic amputees said they wore their limbs all day, compared with only 51 percent of the dysvascular group. Seventy-one percent of traumatic and 43 percent of dysvascular amputees engaged in some form of recreational activity. There was a high incidence of complaints of pain in the residual limb: 55 percent among the dysvascular group and 44 percent among the traumatic group. Half of the patients had socket problems. Fifty-four of the 178 patients received a physical examination, a prosthetic evaluation, and a gait analysis. Among this group, 59 percent of the below-knee prostheses and 78 percent of the above-knee prostheses had inadequate socket fitting. Improper shaping of socket margins was the most frequently observed deficiency. Moreover, 41 percent of below-knee and 22 percent of above-knee amputees had mechanical skin irritation or skin breakdown in the examined residual limbs. Faulty suspension and alignment in addition to improper socket fit and construction contributed to this problem. Excessive stiffness of SACH foot heel cushions was the most common prosthetic foot problem and contributed to gait abnormalities.

Congenital hip dislocation and dysplasia in Southern Chinese.

In 1975 we carried out a survey in Hong Kong to locate Chinese children with congenital dislocation of the hip. Analysis of the available records between 1960 and 1975 gave an observed incidence which was at least 10 times less than found in Caucasians. The age and sex distribution, radiographic findings and the left-sided predominance were similar to Caucasians with congenital dislocation of the hip. However, unlike Caucasian children, the Chinese presented with dislocation and not dysplasia. The mothers of children with congenital dislocation of the hip were compared with a control group with normal children to assess their use of the "Hong Kong" position, in which the children are carried on the back of their mother with their hips in a position of wide abduction. Since only half of the children in either group were carried in this manner, other factors must be responsible for the low incidence of congenital dislocation of the hip in southern Chinese.

Fat embolism in Hong Kong Chinese.

A prospective study on fact embolism showed that of ninety-five patients with a fractured shaft of the femur, seven (7 percent) demonstrated both pulmonary and cerebral disturbances, while there were profound disturbances in arterial PO2, hemoglobin level, pulse rate, and temperature in about 40 per cent of the patients. Using a modified Gurd test, a significant amount of fat was demonstrated in 5.7 per cent of the samples of venous blood and in 18.5 per cent of the samples of arterial blood.