Relationship of femoral head and acetabular size to the prevalence of dislocation

Two clinical studies, one prospective randomized and one retrospective, were performed to evaluate the relationship of femoral head size and acetabular component outer diameter to the prevalence of dislocation of the modular total hip replacement. Between October 1995 and April 1996, 31 primary total hip arthroplasties in 30 patients were randomized to a femoral head diameter of 22 mm or 28 mm, for two groups of acetabular components of outer diameters of 56 mm or larger and 54 mm or smaller. Head size (22 mm) and acetabular component outer diameter (> or = 56 mm) were found to increase the risk of dislocation. From December 1984 to January 1994, 308 primary total hip arthroplasties were performed through a posterior approach by one surgeon using a modular 28 mm femoral head and one type of uncemented acetabular component. The rate of dislocation for acetabular components with an outer diameter of 62 mm or larger was increased significantly (five of 36 hips, 14%) compared with those with an outer diameter of 60 mm or smaller (11 of 272 hips, 4%).     

Failure of femoral head fixation: a cadaveric analysis of lag screw cut-out with the gamma locking nail and AO dynamic hip screw

The most commonly reported failure mode of sliding hip screws in published literature is cut-out of the lag screw. This study investigates the resistance to failure of the femoral head, with lag screws used in two types of sliding hip screws, the gamma locking nail (Howmedica) and the dynamic hip screw (DHS) (Synthes). The investigation consisted of biomechanical tests under static loading conditions on 12 pairs of cadaveric femoral heads, to establish the failure loads due to screw cut-out for the two implant lag screws. The gamma nail appeared to reduce the tendency to cut-out in the osteoporotic bone (soft) associated with elderly patients in whom these devices are commonly used (p < 0.05). In high density bone (hard) the gamma lag screw also appeared to be stronger, because the DHS showed a tendency to bend. The larger diameter of the gamma nail lag screw resists bending and appears to reduce the risk of cut-out compared with the DHS.     

Experimental studies on connective tissue of the capsular ligament. Influences of aging and sex hormones

Influences of aging and sex hormones on connective tissue metabolism in the hip joint capsule of Wistar rats were analyzed both biochemically and morphologically. As age advanced, collagen content and collagen fibril diameter of the hip joint capsule tended to increase gradually in both sexes until sexual maturation was reached. Collagen content was significantly greater in males than in females after sexual maturation. The collagen content and fibril diameter were considerably increased by ovariectomy and significantly decreased by the administration of estrogen, or estrogen combined with progesterone, whereas they were significantly increased by the administration of testosterone in orchiectomized male rats.     

Clinical evaluation of the Alta hip bolt in peritrochanteric hip fractures

We reviewed the clinical and radiographic results of 58 patients with peritrochanteric fractures treated with the Alta hip bolt (a sliding compression device that inserts a dome plunger in the femoral head instead of a hip screw). This group was compared with a group of 53 patients treated with conventional hip screws. Three patients (5.2%) treated with the Alta hip bolt and three patients (5.7%) treated with conventional hip screw had failure of fixation. Failure of fixation consistently occurred in patients with unstable fracture patterns or significant osteopenia. There were no cases of bolt cut-out in stable intertrochanteric fractures. We conclude that the Alta hip bolt performs as well as sliding hip screws in peritrochanteric fractures, but the additional learning curve and increased cost do not justify its routine use at this point in time.     

Developmental subtypes of juvenile bipolar disorder

The incidence of hip fractures has increased over the past decades, and for patients with hip fractures, medical and social conditions have deteriorated during the same time. In this study the results of orthopaedic rehabilitation of patients with Parkinson's disease and a hip fracture are compared with those in all other hip fracture patients. A total of 74 patients with Parkinson's disease and hip fracture were compared with 1,361 patients without the disease. Prior to fracture, patients with Parkinson's disease were less likely to be living an independent life in their own homes. Postoperatively women with Parkinson's disease were hospitalized for a significantly longer period. Postoperative rehabilitation was significantly slower and less successful than among patients without the disease. Patients with Parkinson's disease comprise a subgroup of hip fracture patients who need more rehabilitation resources than can easily be provided at an ordinary orthopaedic ward. A team-work between an orthopaedic surgeon, a neurologist and a rehabilitation unit seems to be mandatory in order to achieve shorter hospitalization and earlier return to the pre-fracture environment.     

Determination of pentachlorophenol in commercially prepared lyophilized human urine control samples

OBJECTIVE: The decision to perform total hip arthroplasty (THA) in patients with osteoarthritis (OA) of the hip is based largely on patients' reports of pain and disability and not on radiographic findings of OA. We determine the severity of radiographic OA and its association with disability in patients undergoing THA. METHODS: Individual radiographic features (osteophytes, joint space narrowing, sclerosis, cysts, deformity) and global severity of hip OA were assessed in 95 consecutive elderly patients with hip OA undergoing THA who were enrolled in a Patient Outcome Research Team (PORT) project. RESULTS: Eighty-seven patients (91.5%) had either severe or moderate OA in the hip to be replaced; 17% of these had a previous contralateral THA. Only 8 patients (8.4%) had mild or no signs of OA in the hip to be replaced and 4 (50%) of these patients had their opposite hip replaced previously. CONCLUSION: These data indicate that radiographic features of moderate to severe hip OA are associated with clinical findings and the necessity to perform THA in the majority of patients. Patients who have had a prior hip replacement, however, may be more likely to have a contralateral replacement done earlier (p = 0.03), before radiographic signs are evident.     

Middle-term results of anatomic medullary locking total hip arthroplasty

We report the results of cementless, anatomic, medullary locking hip prosthesis application in our first consecutive series. We used the so-called Asian size of prosthesis with proportionally smaller stem sizes in both diameter and length. Forty-seven stems and sockets were analyzed with a mean follow-up of 69 months. The mean Merle d'Aubigné hip scores were 8 points preoperatively and 16 points at the final follow-up. Radiologically, the stems showed excellent stability without loosening. Stress shielding around the stems did occur in most cases but did not progress. Preoperative bone quality influenced the extent of stress shielding evaluated at the final follow-up: higher stress shielding was noted in poorer quality bones at the time of operation. There were problems with the sockets. The shallow socket and impingement at the protruded rim seemed to cause a high incidence of dislocation (13%). Massive polyethylene wear occurred in 5 sockets. These sockets were 48 and 46 mm in diameter with 26 mm heads. In conclusion, the stems of the anatomic medullary locking hip prostheses used in Japan showed satisfactory stability even in poor quality bones, but there were problems with the polyethylene liners. Our solution was to use larger sockets with 22 mm heads.     

An algorithm for the management of femoral neck fractures

The choice of total hip arthroplasty should probably be reserved for those rare patients with preexisting osteoarthritis of the hip in the setting of a subcapital hip fracture. Additionally, relative indications for total hip arthroplasty may include the presence of contralateral hip disease; the presence of metabolic bone disease, which may controvert internal fixation or reasonable results with endoprosthetic replacement; and those patients with high activity expectations or life expectancy greater than 5 years. Given the diminished performance of hemiarthroplasty with time and activity, it may be argued that the most cost effective solution to the subcapital hip fracture in the majority of patients may be the reduction and internal fixation pathway, with elective conversion, when necessary, of the approximately 25% of patients who suffer avascular necrosis to total hip arthroplasty. It appears that hemiarthroplasty is best suited for the elderly household ambulator, whereas total hip arthroplasty is the better alternative either as the elective solution to failed internal fixation of femoral neck fractures or in the occasional community ambulator with high activity expectations and irreducible femoral neck fractures. Younger patients, and those with minimally displaced fractures, should be treated with internal fixation in an attempt to preserve the natural hip joint.     

Arthroplasty in the treatment of congenital anomalies of the hip in adults

At the Clinic for Orthopedic Surgery and Traumatology in Novi Sad, 79 adult patients with osteoarthritic hip dysplasia underwent total joint replacement surgery in the period 1984-1993. 45 patients were followed-up for an average time of 4.2 years. The results obtained have been evaluated following the criteria of Postel-Merle-d'Aubigne's hip rating system. After surgery 37 (82.2%) patients had minimal or no pain at all, while the hip flexion was over 75 degrees in 35 (75.5%) patients. 9% of patients could not walk longer than 20 minutes with a flexion under 50 degrees. Firm footfall and slight limp in exhaustion occurred in 35 (75.5%) patients, while 7 (15.5%) patients were extremely unstable and were able to get about on crutches. The gathered results confirm that total hip replacement in patients with osteoarthritic dysplastic hip improves stability and hip joint movement as well as pain reduction.     

Gothenburg osseointegrated hip arthroplasty. Experience with a novel type of hip design

The culmination of more than 10 years of laboratory and clinical research has been the clinical trial of a novel hip arthroplasty for osseointegration. The femoral component of this Gothenburg hip is a neck retaining, threaded fixture with rotational symmetry, produced in commercially pure titanium with a specific surface texture. Proximally, a standard orthopaedic taper trunnion mates with a 28-mm diameter zirconia head that articulates against the acetabular component. The latter is also of textured commercially pure titanium, encapsulating a thick ultra high molecular weight polyethylene liner. Dedicated alignment guides and cutting instruments ensure accurate bone preparation and implant placement. Limited clinical trials commenced in 1992 and expanded to multicenter clinical trials in 1997. Every hip has been monitored with radiostereometry to measure migration to an accuracy of 0.1 mm. All calcar implanted femoral components show excellent function at 4 to 5 years followup, with no migration revealed by radiostereometry.     

Recurrent abdominal pain and Helicobacter pylori in a community-based sample of London children

Alternative anthropometric indexes were compared for their ability to discriminate between 35 Atlanta men with sudden coronary death and 81 male controls. With or without adjustments for age, race, and body mass index, the abdominal diameter index (supine sagittal abdominal diameter divided by midthigh circumference) was associated with sudden coronary death more strongly than the waist/hip ratio or waist/thigh ratio of circumferences.     

Clinical and pathologic findings in hemochromatosis hip arthropathy

During a 9-year period, 15 patients with hemochromatosis hip arthropathy required 19 total hip arthroplasties for disabling hip pain. Preoperative presentation, hip function, pathologic evaluation of the femoral head, and radiographic findings were reviewed. Postoperative followup averaging 5.7 years (range, 2-11 years) was performed to assess hip pain and function after total hip arthroplasty. The average preoperative Hospital for Special Surgery hip score was 15 points (range, 4-24 points), and this improved to 30 points (range, 4-38 points) after total hip arthroplasty. Only one of 15 patients required revision surgery at 10 years for acetabular loosening. All other patients were pain free, with improved function at latest followup. Histologic evaluation of the resected femoral heads revealed evidence of primary or secondary osteonecrosis in seven of 19 (37%) specimens. Articular cartilage avulsion at the level of the tidemark was identified in eight of 19 (42%) specimens, and calcium pyrophosphate deposition was identified in five of 19 (26%) specimens. These pathologic findings suggest a predictable progression of the arthritic process in patients with hemochromatosis.     

Fractures through cystic lesions of the greater trochanter. A cause of late pain after cementless total hip arthroplasty

Four patients who presented with sudden onset of hip pain 7 to 11 years after successful porous-coated cementless hip arthroplasty are described. These four patients were all diagnosed to have fractures through osteolytic cysts in the greater trochanter. One patient was seen initially with a displaced fracture of the greater trochanter. Two patients were treated operatively with curettage of the cystic area and with polyethylene exchange. One of these patients underwent revision of the femoral component in addition to the polyethylene exchange. Two patients were treated nonoperatively. The fractures treated nonoperatively have healed and the patients have resumed their normal activities. This report should stimulate an awareness of fractures through cystic lesions of the greater trochanter as a late cause of hip pain after porous-coated cementless hip arthroplasty.     

Bone loss after hip fracture is correlated to the postoperative degree of mobilisation

This study quantifies changes in bone mineral density (BMD) in the opposite hip and in both proximal tibiae and the correlation with the use of walking aids for patients with two types of hip fracture during the 1st year after surgery. In all, 26 women and 15 men aged 42-88 years (median 71 years) were included. Twenty-one patients had an intracapsular hip fracture (ICF) and 20 had an intertrochanteric fracture (ITF). All patients were treated with a dynamic hip screw. BMD was measured by dual X-ray absorptiometry (DXA; LUNAR, Wisconsin) within the 1st week after surgery and after 3, 6 and 12 months. Initial BMD of the non-fractured hip was significantly lower for both fracture groups compared with reference material. For both fracture types there was a significant decrease in BMD of the non-fractured hip and proximal tibia of the fractured leg during the first 3 months, which still persisted a year after surgery. Improved mobilisation between two examinations was positively correlated with changes in BMD of the proximal tibia of the fractured leg and the non-fractured hip.     

Hip prostheses in women of fertile age. Consequences for sexuality and reproduction

About 6,000 patients undergo total hip replacement in Norway each year. 2.2% of them are women of fertile age, and 14% of them need hip replacement because of inflammatory rheumatic disease. Female patients may wish to know about possible consequences of hip arthroplasty on sexual activity or pregnancy and delivery. An inquiry on these issues was carried out among Norwegian orthopaedic surgeons and obstetricians. The results of the inquiry and a review of the literature can be summarized as follows: Uncomplicated total hip replacement does not preclude normal delivery nor interfere with sexual activity. Some restrictions as regards sexual activity may be advisable during the first three months after hip arthroplasty. Patients with widespread joint or muscle involvement due to inflammatory arthritis need individual counselling. As a rule, pre- and postoperative information to female patients undergoing total hip replacement should take up the possible consequences for sexual activity and reproduction.     

Influence of the Crowe rating on the outcome of total hip arthroplasty in congenital hip dysplasia

Few studies have examined the relationship between the severity of congenital dysplasia of the hip (CDH) and the clinical outcome of total hip arthroplasty. The authors have used a prospective design to study this question, using the Crowe grade to assess the severity of CDH. There were 71 patients with CDH operated on using the S-ROM total hip (Joint Medical Products, Stamford, CT); the control group was composed of 22 patients without CDH operated on using the same implant during the same period as the CDH patients. The patients with mild CDH did not have a different outcome from the patients without CDH with respect to Harris hip score or limp. The higher the Crowe grade, the more complications occurred. It was also found that the patients in whom the true acetabulum was not used had a significantly higher incidence of limp.     

RNA-protein interactions. Diverse modes of recognition

During a 5-year period 1,307 patients with cervical hip fractures were operated on with Olmed screws. In 7 patients one or both screws migrated into the pelvis. 6 patients underwent a total hip arthroplasty without complications, 1 patient had a Girdlestone procedure.     

Hepatitis C virus and liver diseases

Pigmented villonodular synovitis is an uncommon synovial disease which only rarely involves the hip. In a multicenter retrospective study, we identified 58 histologically-proven cases. There were 33 females and 25 males. Mean age at diagnosis was 38 years. In all but two cases, only one hip was involved; the right hip was affected somewhat more often (33 cases) than the left. Two patients probably had bilateral hip disease. Mean delay to diagnosis was four years. Pain was the presenting symptom in most cases. A palpable mass in the groin was found in six patients. Plain roentgenograms were considered normal in only three patients. Bony cysts were seen in 39 patients and kissing cysts in 19. Joint space narrowing was found in 40 patients and was diffuse in half the cases. Roentgenograms suggested pigmented villonodular synovitis in 63% of cases, osteoarthritis of the hip in 16%, and inflammatory hip disease in 14%. Additional imaging studies included opaque arthrography in 21 subjects, computed tomography in 23, magnetic resonance imaging in 11, and arthroscopy in 9. Initial treatment was osmic acid synoviorthesis in 14 patients, partial synovectomy in 9, and total synovectomy in 21; in addition, eight patients had insertion of a cup prosthesis and 13 had total arthroplasty of the hip. Treatment was successful in 65% of cases after a mean follow-up of three years; among the 35% of failures, there were seven recurrences (14%). Total hip arthroplasty was performed secondarily in nine patients. This study illustrates the diversity of roentgenological changes in pigmented villonodular synovitis of the hip and the high frequency of osteoarticular lesions precluding conservative treatment. Magnetic resonance imaging and/or arthroscopy should be used to establish the diagnosis at an early stage when conservative treatment with total synovectomy and synoviorthesis is most likely to be successful.     

In vivo high resolution MRI of the calcaneus: differences in trabecular structure in osteoporosis patients

The purpose of this study was to use high resolution (HR) magnetic resonance (MR) images of the calcaneus to investigate the trabecular structure of patients with and without osteoporotic hip fractures and to compare these techniques with bone mineral density (BMD) in differentiating fracture and nonfracture patients. Axial and sagittal HR MR images of the calcaneus were obtained in 50 female (23 postmenopausal patients with osteoporotic hip fractures and 27 postmenopausal controls). A three-dimensional gradient-echo sequence was used with a slice thickness of 500 micron and in plane resolution of 195 x 195 micron. Texture analysis was performed using morphological features, analogous to standard histomorphometry and fractal dimension. Additionally, BMd measurements of the hip (dual-energy X-ray absorptiometry) were obtained in all patients. Significant differences between both patient groups were obtained using morphological parameters and fractal dimension as well as hip BMD (p < 0.05). Odds ratios for the texture parameters apparent (app.) bone volume/total volume and app. trabecular separation were higher than for hip BMD. Receiver operator characteristic values of texture measures and hip BMD were comparable. In conclusion, trabecular structure measures derived from HR MR images of the calcaneus can differentiate between postmenopausal women with and without osteoporotic hip fractures.     

Increased plasma levels of substance P and disturbed water excretion in patients with liver cirrhosis

We describe a surgical technique for replacing the hip joint capsule using synthetic mesh after oncological resections of the proximal femur that resulted in gross intraoperative instability of the prosthetic reconstruction. The results of its use in 13 patients, 6 of whom also had pelvic resections, are described. These patients were selected from a total group of 88 patients undergoing proximal femoral replacement, 75 of whom did not require capsular replacement (none of these 75 patients have experienced dislocation). In the group requiring capsular reconstruction, 1 of 4 patients with bipolar hemiarthroplasty and 4 of 9 patients with total hip replacements experienced dislocation after operation. Of the dislocated total hip replacements, 1 remains chronically dislocated, and 3 were successfully stabilized by open reduction with further capsular augmentation. Given that the resections involved removal of most of the soft tissues stabilizing the hip joint, we believe that the technique of capsular reconstruction is useful in this difficult group of patients.