Primary hybrid total hip arthroplasty: an interim followup

The senior authors' initial experience with primary hybrid hip replacement in patients with osteoarthritis was studied to evaluate the efficacy of the procedure. Hybrid total hip arthroplasty (uncemented Harris-Galante acetabular component and cemented Iowa precoated femoral component) was performed in 131 consecutive, nonselected hips in 118 patients with the diagnosis of primary osteoarthritis. Followup was performed at 8 to 9 years after the procedure. The average age at the time of the procedure was 68 years (range, 45-87 years). There were 50 men (55 hips) and 68 women (76 hips). At final followup 19 patients (22 hips) had died. The femoral component had been revised for aseptic loosening in 8 hips (6.1%). One additional hip showed definite radiographic loosening. Hence, the prevalence of radiographic femoral failure was 6.9% (9 hips). No acetabular component had been revised for aseptic loosening and no acetabular component had migrated. The senior author continues to perform hybrid total hip arthroplasty in all patients with primary osteoarthritis. However, design modifications have been made in the femoral component that is used.     

Femoral head osteonecrosis after bone marrow transplantation

Thirty-five patients with bilateral osteonecrosis of the femoral head after bone marrow transplantation were reviewed retrospectively. The median age at the time of transplantation was 26 years. The first symptoms occurred within 2 years of transplantation. At presentation, 18 of the patients reported pain in both hips, 17 had symmetric radiographic lesions, and 39 of the hips had collapsed. Medical treatment was indicated initially. At the final examination before surgery (median, 3.5 years), 31 patients had bilateral hip pain, 22 patients had symmetric radiographic lesions, and 56 of the hips had collapsed. Fifty-seven of the hips required surgery, including one open drainage, four core decompressions, six cup arthroplasties, and 46 primary total hip replacements. Six hips (four core decompressions; two cups) later underwent total hip replacement revision, and a deep infection developed in one. By considering the requirement of a total hip replacement as a failure of conservative treatment, the rate of survival of the femoral head was 30% 5 years after the transplant. There was no significant difference between the Ficat grades, except for Grade 0, which showed a higher survival rate. The study of the specific features of the osteonecrosis may lead to the recommendation of primary total hip arthroplasty after failure of the medical treatment.     

Osteonecrosis of the femoral head. Hip salvaging with implantation of a vascularized fibular graft

The authors tried to save the hip joint by implanting a vascularized fibular graft, augmented with cancellous bone, into the curetted core of the femoral head that was affected by aseptic necrosis. Forty of 66 hips were observed for a minimum of 20 months and for as long as 66 months (average, 32 months). Clinical assessment according to the cause and severity of the disease was done using the Harris Hip Score. Twenty-eight hips (70%) were rated excellent, 7 (17.5%) were good, 2 (5%) were fair, and 3 (7.5%) failed and were replaced with an artificial joint. Clinically satisfactory results, including good and excellent, were obtained in 35 hips (87.5%). Radiographic evaluation showed improved appearance of the femoral head core in all 15 patients (37.5%) operated on at a precollapse stage of the disease. In 20 hips, the deformity of the femoral head was unchanged (50%), 2 (5%) became worse, and 3 (7.5%) failed. The number of hips with improved appearance as shown on radiographs and those in which the process was unchanged equaled the number of hips with satisfactory clinical results. These data show that the procedure can induce new bone formation that fuses with the affected subchondral bone, thus preventing the articular surface from collapse. This suggests that vascularized fibular grafting is an excellent alternative for hip salvaging when treating femoral head osteonecrosis.     

Active laboratory consultation for the clinical supporting system in the general hospital

OBJECTIVE: To study demographic, clinical, and radiographic staging patterns in patients with multifocal osteonecrosis to facilitate earlier diagnosis and optimize treatment. METHODS: Multifocal osteonecrosis was defined as disease of 3 or more anatomic sites. Patients were characterized demographically, which included disease associations, corticosteroid and other agent usage, presenting joints, and symptomatology. Radiographically, patients were evaluated with plain radiographs and magnetic resonance imaging (MRI) scans of all joints to determine the presenting stage of the lesions. RESULTS: We found that 32 of 1056 (3%) osteonecrosis patients under our care had multifocal disease. Associated factors included systemic lupus erythematosus (13 patients), inflammatory bowel disease (5 patients), malignancy (4 patients), and renal transplantation (3 patients). Thirty of the 32 patients (94%) had a history of corticosteroid therapy, with the other 2 patients found to have a coagulopathy. All 32 patients had bilateral femoral head involvement and 30 of 32 had bilateral knee involvement, with the other 2 having only left knee lesions. Osteonecrosis was also seen in the shoulder (28 patients), ankle (8 patients), and 3 other sites. Overall, 201 sites were involved (6.3 per patient). The majority of joints presented in a pre-collapse stage (77%). Patients most commonly presented with hip or multiple joint symptoms (22 patients, 69%). In 8 patients, the knee was the sole presenting symptomatic joint and the ankle and shoulder were the sole presenting symptomatic joints in one patient each. CONCLUSION: In patients with a diagnosis of osteonecrosis and complaints in other joints, these other areas should be fully evaluated with plain radiographs and, if inconclusive, with MRI. In patients with osteonecrosis not involving the femoral head, the patient's hips should be radiographically evaluated regardless of whether the patient is symptomatic. Patients diagnosed with osteonecrosis of the knee, shoulder, or ankle should have other joints evaluated, as such patients have multifocal disease roughly 50% of the time.     

Predictive value of early radiographic findings in cementless total hip arthroplasty femoral components: an 8- to 12-year follow-up

Total hip replacement was performed in 119 patients (124 hips) with an uncemented Ortholoc femoral component between 1982 and 1987. Eight patients (9 hips) died, and 13 patients (15 hips) were lost to follow-up, leaving 98 patients (100 hips) followed for 8 to 12 years. Pain scores and anteroposterior and lateral radiographs of the femoral component from the 2-year follow-up visit were evaluated. Twenty-four of the 100 hips were revised for aseptic loosening. Radiographic criteria were highly effective in predicting those cases that would require revision. Radiolucent lines occurred at a higher frequency in all Gruen zones of the revision group radiographs, and the differences were statistically significant in zones 1, 7, 8, and 14 (P < .001). Proximal radiolucent lines were present in all of the revision cases and in 45% of the nonrevision cases. Radiolucent lines occurring on the lateral view alone were a statistically significant predictor of future need for revision (P < .001). Presence of radiolucent lines around the porous coating was 100% sensitive and 55% specific in predicting future revision. Absence of radiolucent lines around the porous coating was 100% sensitive and 45% specific in predicting no need for revision in the first 8 years.     

Bilateral total hip arthroplasty: a single procedure

A total of 196 patients with bilateral hip disease underwent the simultaneous bilateral total hip arthroplasty procedure (392 hips), compared with 427 patients with unilateral disease and one hip replaced. A multiple regression analysis showed no difference between the 2 groups in regard to age, sex, and preoperative diagnosis. The mean length of operation was 3 hours for the bilateral group and one hour and 15 minutes for the unilateral group, with a mean blood loss of 3 units and 0.5 units respectively (the majority of the patients were given hypotensive anesthesia. Post-operative complications revealed no differences in the phlebitis (1% for each group), clinical pulmonary emboli (1% for each group), dislocation (1% for unilateral and none for the bilateral group), and non-union of the greater trochanter (11% for the unilateral group and 12% for the bilateral group). The unilateral group revealed 25% ectopic ossification vs. 36% for the bilateral group (p < 0.008). The mean hospital stay was 14 days for the unilateral group and 16 days for the bilateral group, at respective costs of $4,137 and $5,780. There were signs of clinical loosening in 1% of both groups. The infection rate was 1% for both. An analysis of covariance revealed no follow-up differences between the 2 groups in regard to pain, abduction status, or functional capabilities, although the range of motion was better in the unilateral group (p < 0.001), as may be expected, with less initial range of motion, there was also more postoperative ectopic ossification. Replacement of both hips under one anesthetic benefits patients in that the postoperative complications are the same as for the procedure for one hip; the length of hospitalization and convalescence are only slightly longer; the postoperative follow-up shows no differences except for a slight restriction in range of motion for the bilateral group; and the cost represents a 30% savings over that of a unilateral hip performed twice.     

Vascularized iliac bone graft for treating avascular necrosis of the femoral head

BACKGROUND: Nontraumatic avascular necrosis of the femoral head (ANFH) is a common disorder causing disability of the hip joint. The means for optimally treating this disease are still controversial. In this study we evaluated the relatively new technique of vascularized iliac bone grafting for treating ANFH. METHODS: From March 1990 to March 1992, 17 hips (15 patients) with ANFH were treated using the vascularized iliac bone grafting technique in our hospital. The patients included 12 men and three women, with an average age of 38 years. Steinberg's classification was used to categorize the severity of hip disease. The clinical results were classified as excellent, good, fair and poor according to symptoms, hip function and roentgenographic changes after surgery. Life-table analysis was applied to assess graft survival and the log rank test was used to compare statistical differences between the steroid-related and nonsteroid-related groups. RESULTS: Cumulatively, 16 hips (14 patients), excluding one patient (one hip) lost to follow-up, were clinically evaluated for an average of 68 months. Among 12 hips at Steinberg stage II, eight progressed to stage IV, three to stage III and only one remained at stage II. Although most hips at stage II showed mild to moderate disease progression on plain radiography, 58% of the hips (7/12) that progressed to less than IVb showed good to excellent results. In the three hips at stage III, one progressed to stage IVa and two to stage V. In the two hips at stage IV, one remained at stage IV at final follow-up and the other was lost to follow-up. The steroid-related and nonsteroid-related groups did not differ with respect to clinical results. Both groups had 63% (5/8) good to excellent results (p > 0.05, log rank test). Only four hips were converted to prosthetic arthroplasties at final follow-up. Overall, 63% (10/16) of the hips had good to excellent results, 12% had fair results and 25% had poor results. Graft survival after seven years of follow-up was 63%. CONCLUSIONS: While treatment of ANFH still poses a challenge to orthopedic surgeons, the vascularized iliac bone grafting technique is a clinically acceptable option for treating the early stages of ANFH.     

Clinically occult avascular necrosis of the hip in systemic lupus erythematosus

OBJECTIVE: To study the natural history of clinically occult avascular necrosis (AVN) of the hip in patients with systemic lupus erythematosus (SLE). METHODS: Sixty-six patients with SLE (without symptoms referable to the hip) receiving at least 5 mg/day prednisone for > or = 6 months were screened by magnetic resonance imaging (MRI) for AVN of the hip. A complete MRI evaluating class and percentage of femoral head involvement, AP and lateral radiographs of the hips, bone scan, and physical examination were performed for patients with positive MRI. Medical records were reviewed for serologic and clinical variables that might predict AVN. Repeat MRI were obtained at 3, 6, and 12 months to assess possible progression or resolution of the lesion. Patients with negative screening MRI underwent repeat screening after one year to assess the one year incidence rate. RESULTS: Eleven asymptomatic hips (8%) in 8 patients (12%) had MRI documented AVN. The percentage of femoral head involvement ranged from 1 to 46%. One lesion was MRI class B, the remaining lesions were class A. The radiographic stage of 10 hips was stage 1, the MRI class B hip was stage 2. Risk factors for clinically occult AVN included Afro-American origin, Raynaud's phenomenon, migraine headaches, and a maximal corticosteroid dose of at least 30 mg/day. After 12 months, 43 of 58 patients with an initially negative MRI underwent repeat screening examinations; no new lesions were observed. CONCLUSION: Clinically occult AVN of the hip is common in patients with SLE. The short term natural history of these lesions appears stable without spontaneous healing or clinical or radiographic progression. Risk factors for these asymptomatic lesions are similar to the risks for symptomatic AVN and surgical intervention appears not to be indicated in these patients.     

Isolation of the Bacillus subtilis cdd downstream region and analysis of genetic structure around the cdd vicinity

A 40-year experience consisting of 91 cases of acute slipped capital femoral epiphysis (SCFE) was reviewed to assess the safety of manipulative reduction and to determine whether urgent reduction has an effect on the development of avascular necrosis (AVN) of the capital femoral epiphysis. All patients had a history of sudden onset of severe hip pain and were documented to have an unstable (acute) slipped epiphysis. Treatment modalities included manipulative reduction under general anesthesia followed by internal fixation (41 hips), epiphysiodesis and internal fixation (15 hips), epiphysiodesis and cast immobilization (31 hips), and cast immobilization alone (three hips). One case was treated with cast immobilization after reduction by skeletal traction. Patient follow-up averaged 44 months, and ranged from 12 to 216 months. Radiographic review identified 13 (14%) cases of AVN in the series of 91 hips. Of 42 hips reduced in <24 h from presentation, AVN developed in three (7%). Of 49 hips reduced in >24 h from presentation, AVN developed in 10 (20%). Manipulative reduction of the acute SCFE may be accomplished without increased risk of AVN. Time to reduction may be an important risk factor for development of AVN after acute SCFE.     

Fractures of the acetabulum: accuracy of reduction and clinical results in patients managed operatively within three weeks after the injury

The results were reviewed for 259 patients who had open reduction and internal fixation of 262 displaced acetabular fractures within twenty-one days after the injury. Two hundred and fifty-five hips were followed for a mean of six years (range, two to fourteen years) after the injury; the remaining seven, which clearly had a poor result, were followed for less than two years. According to the classification of Letournel and Judet, associated fracture types accounted for 208 (79 per cent) of the fractures, with both-column fractures being the most common type (ninety-two hips; 35 per cent). Two hundred and fifty-eight hips were operated on with a single operative approach (Kocher-Langenbeck, ilioinguinal, or extended iliofemoral). The four remaining hips were operated on with a Kocher-Langenbeck as well as an ilioinguinal approach. The reduction was graded as anatomical in 185 hips (71 per cent). The rate of anatomical reduction decreased with increases in the complexity of the fracture, the age of the patient, and the interval between the injury and the reduction. The over-all clinical result was excellent for 104 hips (40 per cent), good for ninety-five (36 per cent), fair for twenty-one (8 per cent), and poor for forty-two (16 per cent). The clinical result was related closely to the radiographic result. The clinical result was adversely affected by associated injuries of the femoral head, an older age of the patient, and operative complications. It was positively affected by an anatomical reduction and postoperative congruity between the femoral head and the acetabular roof. Osteonecrosis of the femoral head was noted in eight hips (3 per cent), and progressive wear of the femoral head was seen in thirteen (5 per cent). Subsequent operations included a total replacement of seventeen hips (6 per cent), an arthrodesis in four (2 per cent), and excision of ectopic bone in twelve (5 per cent). These findings indicate that in many patients who have a complex acetabular fracture the hip joint can be preserved and post-traumatic osteoarthrosis can be avoided if an anatomical reduction is achieved. An increase in the rate of anatomical reduction and a decrease in the rate of operative complications should be the goals of surgeons who treat these fractures.     

Surface replacement hemiarthroplasty for the treatment of osteonecrosis of the femoral head

We reviewed the results of thirty-three femoral resurfacing procedures in twenty-five patients who had stage-III or early stage-IV osteonecrosis of the femoral head according to the classification system of Ficat and Arlet. There were no perioperative complications. Thirty hip prostheses (91 percent) survived for a minimum of five years. At a mean of 10.5 years (range, four to fourteen years) postoperatively, sixteen (62 percent) of the twenty-six hips with stage-III disease had a good or excellent Harris hip score. Four of the seven hips with stage-IV disease did not have or need a total hip arthroplasty. Overall, twenty hips (61 percent) had a good or excellent result according to the scoring system of Harris, and thirteen (39 percent) had a fair or poor result and subsequently had or needed a total hip arthroplasty. The mean interval between the hemiarthroplasty and the total hip arthroplasty was sixty months (range, thirty-six to 136 months). These thirteen hips all had a successful clinical result (a Harris hip score of at least 80 points) at a mean of thirty months (range, twenty-four to seventy-two months) after the total hip arthroplasty. The results of the present study suggest that resurfacing of the femoral head can be a successful interim procedure for the management of patients who have Ficat and Arlet stage-III or early stage-IV disease with a large lesion that is not amenable to other treatment options except total hip arthroplasty.     

Total hip arthroplasty with cement in patients who have rheumatoid arthritis. A minimum ten-year follow-up study

One hundred and six consecutive total hip arthroplasties with cement were performed by one surgeon, at least ten years before the time of the present clinical and radiographic review, in seventy-five patients who had adult-onset rheumatoid arthritis. Two patients (three hips) were lost to follow-up. Seven (7 per cent) of the remaining 103 hips were revised. The revisions were performed because of infection (three hips), dislocation (two hips), or aseptic loosening (two hips). Of the ninety-eight hips that were not lost to follow-up or revised because of infection or dislocation, eight (8 per cent) had radiographic loosening of the acetabular component and two (2 per cent) had radiographic loosening of the femoral component. Although the prevalence of radiographic loosening of the acetabular component was four times greater than the prevalence of radiographic loosening of the femoral component, the prevalence of revision because of aseptic loosening of the acetabular component was identical to that for the femoral component (one component each). These results compared favorably with those of total hip arthroplasty with cement, performed by the same surgeon, for the treatment of other diagnoses. Loosening of the acetabular component was significantly associated with a younger age at the time of the index operation (p = 0.03) and with acetabular osteolysis (p = 0.0006). Of forty-eight hips in thirty-two patients who survived for at least ten years, 96 per cent (forty-six hips) were considered by the patients to have a satisfactory result. At the time of the latest follow-up, twenty-four (75 per cent) of the patients had no pain in the hip. Although eighteen patients (56 per cent) could walk without support at a minimum of ten years after the operation, we found that the functional results for patients who had rheumatoid arthritis were inferior to those observed for patients who had had a total hip arthroplasty with cement, performed by the same surgeon, for the treatment of other diagnoses.     

Rationale of a flexible press fit cup in total hip replacement. 5-year followup in 280 procedures

A consecutive series of 280 total hip replacements in 261 patients using the Press Fit Cup with a minimum followup of 5 years is presented. The Press Fit Cup is a nonmodular acetabular component with a porous coating made of titanium fibers. It has one peg and is 1.5 mm oversized with biradial eccentricity. It has a flattened pole area, requires no screw fixation, and partially preserves elasticity. The mean age was 71 years for women, 70 years for men. Forty-seven patients (49 hips) died before the 5-year review, and five patients were unable to return for the followup because of physical infirmity. Two hundred eighteen patients (226 hips) were available for the clinical 5-year followup, and 208 patients (213 hips) were available for the radiographic followup. No intraoperative fracture of the acetabulum occurred; four hips dislocated; 94% clinically were rated as excellent or good. One hip in a patient with rheumatoid arthritis had to be revised for aseptic loosening of the cup and nine femoral stems had to be revised. No migration of the cup could be measured. There was no osteolysis seen around the cup. In six cases a radiolucent line was seen in Zone 1, and in eight hips in Zone 3. There was one hip with a continuous radiolucent line which was considered radiographically loose.     

Total hip arthroplasty performed without cement in patients with femoral head osteonecrosis who are less than 50 years old

Seventy-two cementless total hip arthroplasties were performed by a single surgeon in 58 patients with the diagnosis of femoral head osteonecrosis. All patients were less than 50 years old (mean, 37 years). The mean follow-up was 84 months with a minimum of 48 months. Good-to-excellent results were maintained at final follow-up in 94% of the hips. Revision rate was 1.5% each for the cups and the stems. Mechanical failure rate was 7.6% for the cups, and 6% for the stems. If the results were analyzed excluding the data from the group of patients who received the Mittelmeier prostheses, the mechanical failure rates for the cups was 0% and for the stems was 4.2%. The probability of survival for the entire series using revision as the endpoint was 96.9% at 11 years. Survival probability decreased to 88.5% if radiographic failures were included. Excluding the Mittelmeier prostheses, survival probability was estimated to be 100% for the cups using both revision and radiographic failures as endpoints; for the stems, the survival probability was 98.0% using revision as the endpoint and 95.8% including radiographic failures. Femoral osteolysis was observed in 1.5% of the hips. No hip had acetabular osteolysis. No measurements of polyethylene wear were attempted in this study. These results appeared superior to total hip arthroplasties done with early cementing techniques in this population of young patients with femoral head osteonecrosis.     

Treatment of developmental dysplasia of the hip after failed open reduction

It is difficult to obtain a good result by secondary open reduction if a primary open reduction for developmental dysplasia of the hip (DDH) fails. Complications such as avascular necrosis of the femoral head and subluxation of the hip are common. In this study, we retrospectively reviewed the causes of failure of primary open reduction and the final clinical and radiographic outcomes of 32 patients (34 hips) with DDH who underwent repeat open reduction and other procedures from January 1982 to December 1995. The ages of the patients at the time of the secondary operation ranged from 1.5 to 16.5 years (mean, 5.9 yr). The interval from the primary open reduction to the secondary procedure ranged from 3 days to 10 years (mean, 8.9 mo). In most cases (30 hips), the position of the redislocated femoral head was T?nnis grade 3 or 4. Avascular necrosis of the femoral head was evident in about half of the hips before the secondary open reduction. The most common cause of failure of the primary operation was a tight inferior capsule and transverse acetabular ligament, which blocked complete reduction. At a mean follow-up period of 42 months (range, 24-147 mo) after the secondary operation, the radiographic classification was Severin class 1 or 2 in 15 of the 34 hips, and Severin class 3 or worse in the remaining 19 hips. Clinically, according to the modified McKay criteria, 18 of the 32 patients (18 hips) had excellent or good results, and three patients (four hips) had poor results. In conclusion, the main cause of failure of the primary open reduction of DDH was technical error. We believe that detailed preoperative evaluation is critical for the success of primary open reduction of DDH.     

Avascular necrosis and the Pavlik harness. The incidence of avascular necrosis in three types of congenital dislocation of the hip as classified by ultrasound

We analysed the incidence of avascular necrosis in 101 hips of 90 infants with congenital dislocation treated with Pavlik harness and followed up for more than one year. Using ultrasonography in the flexed-abducted position the hips were classified as type A when the femora head was displaced posteriorly, but within the socket and making contact with the posterior inner wall of the acetabulum; type B when it was in contact with the posterior margin of the acetabulum, with its centre at this level or anterior to it; and type C when it was displaced out of the socket, with its centre posterior to the posterior rim of the acetabulum. Eighty-seven hips were reduced by the harness (86%), and seven of these developed avascular necrosis (8%). All 69 hips with type-A dislocation were reduced and only one (1.4%) showed slight avascular necrosis. Eighteen (78.3%) of 23 hips with type-B dislocation were reduced, and six developed avascular necrosis (33.3%). In one hip, the femoral head was severely damaged. None of the nine hips with type-C dislocation was reduced in the harness. We concluded that the Pavlik harness is indicated for type-A but not for type-B or type-C dislocations.     

Use of osteonics UHR hemiarthroplasty for fractures of the femoral neck

A clinical and radiographic study of bipolar hip arthroplasties was performed for fractures of the femoral neck. All patients were treated with the Osteonics UHR system. Clinical results were evaluated in 77 patients (77 hips) who were observed for an average of 4.8 years (range, 2-10 years). At the latest followup, 67 (87%) patients were rated as having a good or excellent outcome according to the Hospital for Special Surgery hip rating system. Clinical ratings in patients treated with cementless UHR were similar to or better than those of patients with cemented UHR. Hip dislocation occurred in only 3 (2.3%) patients, in whom the hip joint was reduced by a closed procedure without inducing disassembly of the prosthetic components. None of the patients had definitive acetabular erosion. The motion of the outer head was evaluated radiographically in 63 patients in weightbearing and non-weightbearing conditions, 3 to 108 months after surgery. The relative motion at the 2 sites of articulation of the outer head had stabilized by 3 months after surgery and subsequently remained unchanged. The authors' findings indicate that UHR hemiarthroplasty of the femoral head is a reliable treatment for fractures of the femoral neck.     

Gadolinium-enhanced MR imaging of pediatric patients after reduction of dysplastic hips: assessment of femoral head position, factors impeding reduction, and femoral head ischemia

OBJECTIVE: We describe gadolinium-enhanced MR imaging of position and vascular enhancement of the femoral head in pediatric patients who have undergone reduction of hip dislocation. SUBJECTS AND METHODS: Within 24 hr of hip reduction and spica casting, we performed 25 gadolinium-enhanced MR studies in 18 infants and young children (15 girls, three boys) with 23 dysplastic hips. All but two patients underwent closed reductions. We evaluated intraoperative arthrograms for obstacles to reduction and subsequent radiographs for avascular necrosis. RESULTS: MR images showed that all femoral heads were in their respective acetabula, but several structures interfered with concentric reduction. Obstacles to reduction included a pulvinar (n = 16), infolding of the capsule (n = 9), interposition of the labrum (n = 2), and a hypertrophied ligamentum teres and transverse ligament (n = 2). All 50 femoral heads showed enhancement: 35 normally, 10 homogeneously but less than on the contralateral femoral head or the ipsilateral greater trochanter, and five with areas of focally decreased enhancement. Hips that showed decreased enhancement had undergone greater degrees of abduction (r = .38, p < .01). CONCLUSION: Gadolinium-enhanced MR imaging can reveal abnormalities of hip position and proximal femoral epiphyseal and physeal vascularity that can occur after hip reduction. Abnormalities of enhancement were more frequent in patients who had greater femoral abduction. The effect of decreased epiphyseal vascular enhancement is still uncertain.     

Granulocytic sarcoma as isolated extramedullary relapse after donor lymphocyte infusion in a patient with CML who relapsed after allogeneic bone marrow transplantation: a case report

Nineteen patients with spina bifida and bilateral dislocation of the hips were studied with a minimal follow-up of 10 years. The average age at review was 21 years (range, 10-31). Ten patients had an upper neurologic level (thoracic to L3), and nine had a low lesion (L4 to sacrum). Three patients had no hip surgery. A closed or open reduction was performed in 12 hips, supplemented by one or more surgical procedures. Of these, 10 remained enlocated, and two had redislocated. In all other hips, several surgical procedures were performed, aimed at improvement of hip-flexion deformity or stability. At follow-up, one patient had occasional pain in one hip, which was dysplastic. Of the 10 patients with a high lesion, only two were walkers, but both had bilateral dislocation of the hips at follow-up. In contrast, all nine patients were walkers, but four of these had bilateral dislocation at follow-up. We found that a level pelvis and good range of motion of the hips are more important for ambulation than is reduction of bilateral hip dislocation.     

Isolated revision acetabuloplasty using a porous-coated cementless acetabular component without removal of a well-fixed femoral component. A 3- to 9-year follow-up study

The results of isolated acetabular revision performed in 31 patients (32 hips) were monitored for between 3 and 9 years. All femoral components were well fixed and not removed or revised at the time of index surgery. There were 4 hips with little or no acetabular bony defect, 2 hips with pure segmental defects (type I), 10 hips with cavitary defects (type II), 15 with combined segmental cavitary defects (type III), and I with pelvic discontinuity (type IV). All revision acetabular implants were cementless, using a porous-coated hemispheric cup with or without bone-graft. There were four grade I reconstructions, 16 grade II reconstructions, and 12 grade III reconstructions. At final follow-up evaluation 94% of the cups were judged to be stable. Two hips required a second revision acetabuloplasty because of loss of fixation of the cup. The 2 repeat revisions were also done without removal of the femoral component. One acetabular component had evidence of rotational migration, which stabilized and remained nonprogressive. There were no cases of femoral component radiographic or clinical failure. The mean pre and postoperative hip scores were 44 and 83, respectively. The pre- and postoperative pain scores were 12 and 42, respectively. The findings of this study suggest that isolated acetabular revision, using a cementless porous-coated hemispheric cup, can be successfully performed without removing or revising a well-fixed femoral stem and not compromise the final outcome.