Time Of Total Hip Arthroplasty Research Articles

Surgical skills training for primary total hip arthroplasty.

A total of 483 hips treated by primary total hip arthroplasty (THA) were investigated to evaluate the surgical skill of the performing surgeon. Surgical trainees operated on 259 hips and instructors on 224 hips. The average age of the patients at the time of THA in the trainee and instructor group was 61.9 and 60.8 years old, respectively. The average follow-up duration was 5.1 years. The operative time in the trainee group and instructor group was 87.0 and 73.1 min, respectively (p=0.031). Complications were noted in 11 hips (3.5%) in the trainee group; acetabular fracture, 3 hips; dislocation, 3 hips; femoral artery lacerations that needed repair surgery, 2 hips; sciatic nerve palsy, 2 hips; and skin necrosis, 1 hip. Complication were noted in three hips (1.3%) in the instructor group; femoral fracture, 1 hip; acetabular fracture, 1 hip; dislocation, 1 hip. Complication rate in the trainee group was higher than in the instructor group. The monitored quality of the surgeries performed by trainees and instructors was not significantly different. Poor quality was identified in 14 hips in the trainee group and 6 hips in instructor group. No significant difference was found in the hip score between the trainees and instructors before and after surgery. Revision arthroplasty was defined as the end-point for primary THA. Kaplan-Meier survivorship at 5 years after primary THA was 97.2% in trainee group and 97.3% in the instructor group. Short-term clinical and radiographic results of primary THA in the trainee and instructor groups were considered safe and satisfactory.

Total hip replacement for arthritis following tuberculosis of hip.

To present the results of total hip arthroplasty (THA) for post tubercular arthritis of the hip joint. Sixty-five patients (45 male, 20 female) with previously treated tuberculosis of the hip joint underwent cementless THA for post tubercular arthritis. The average age at the time of THA was 48 years (range 29 to 65 years). Erythrocyte sedimentation rate, C reactive protein, chest X-ray and contrast enhanced magnetic resonance imaging were done preoperatively to confirm resolution of the disease and to rule out any residual disease. Intra-operative samples were taken for microbiological examination, polymerase chain reaction (PCR) and histological examination. Patients were started on anti-tubercular drugs one week before the operation and continued for 6 mo post operatively. The patients were followed up clinically using the Harris hip score as well as radiologically for any loosening of the implants, osteolysis and any recurrence of tuberculosis. Any complications especially the recurrence of the infection was also recorded. The mean interval from completion of antitubercular therapy for tuberculosis to surgery was 4.2 years (range, 2-6 years). Preoperatively, 17 patients had ankylosis whereas 48 patients had functional but painful range of motion. The mean surgical time was 97 min (range, 65-125) whereas the mean blood loss was 600 mL (range, 400-900 mL). The average follow up was 8.3 years (range 6-11 years). The average Harris Hip score improved from 27 preoperatively to 91 at the final follow up. Seventeen patients had acetabular protrusion which was managed with impaction grafting and cementless acetabular cup. The bone graft had consolidated in all these 17 patients at the follow up. Two patients developed discharging sinuses at 9 and 11 mo postoperatively respectively. The discharge tested positive for tuberculosis on the PCR. Both these patients were put on antitubercular therapy for another year. Both of them recovered and had no evidence of any loosening or osteolysis on X-rays. There were no other complications recorded. Total hip replacement restores good function to patients suffering from post tubercular arthritis of the hip.

Anatomy of the proximal femur at the time of total hip arthroplasty is a matter of morphotype and etiology but not gender.

This study aimed to determine (1) whether: gender, morphotype, or etiology are correlated with the shape of the proximal femur in patients with advanced hip osteoarthritis and (2) is there any clinical predictive factors of potential abnormal anatomy of the hip at the time of total hip arthroplasty (THA)? We reviewed 689 European hips of patients who underwent THA for primary osteoarthritis (OA) or avascular necrosis (AVN), between 2000 and 2005. The patients were stratified according to their (1) Morphotype, (2) Gender, and (3) Etiology for undergoing THA. Two independent observers measured the following four anatomical parameters on preoperative CT-scans: neck shaft angle (NSA) and femoral neck version, femoral offset and lower-limb torsion. Our results showed that both morphotype and etiology, but not gender or body mass index, were correlated with femoral anatomical parameters. Two types of patients were identified as "at risk" for abnormal hip anatomy: (1) AVN-Endomorphic patients (2) OA-Ectomorphic patients. Etiology of the advanced hip osteoarthritis and patients' morphotype may predict the proximal femur anatomy at the time of THA.

Progression of Hip Joint Deformity during the Management of Pelvic Insufficiency Fracture in a Patient with Rheumatoid Arthritis: A Case Report

Introduction: An insufficiency fracture is a type of non-traumatic fracture caused by bone fragility that most commonly occurs in the pelvis and lower extremities. Although sacral insufficiency fracture is not uncommon, its diagnosis is often delayed or missed. We here report the case of SIF with rheumatoid arthritis that occurred during the pre-operative waiting time for total hip arthroplasty. Case presentation: A 57-year-old woman with rheumatoid arthritis presented with sacral insufficiency fracture that occurred during the pre-operative waiting time for total hip arthroplasty. During the four months after the onset of the sacral insufficiency fracture, her pubis, ischium and acetabulum fractured and deformity of her left hip joint gradually progressed. Total hip arthroplasty was performed using bone grafting onto the acetabulum from the autogenous femoral head. The findings upon clinical examination and the patient’s assessment of function were excellent at the time of the most recent follow-up. Conclusion: When total hip arthoplasty is performed in patients with severe osteoporosis or insufficiency fracture of the acetabulum, it is essential to avoid additional pelvic factures at the time of setting the acetabular cup component. Moreover, as a total hip arthoplasty might itself be a predisposing causative factor of pelvic insufficiency fracture, recurrence of insufficiency fractures should be monitored in those patients with the history. Aggressive intervention for osteoporosis might be necessary to prevent insufficiency fracture development.

Posttraumatic Arthritis From Gunshot Injuries to the Hip Requiring a Primary THA

Gunshot injuries to the hip can be devastating, leading to posttraumatic arthritis and presenting a surgical challenge at the time of total hip arthroplasty (THA) due to the presence of metallic fragments and damaged soft tissues. However, there are few reports of gunshot-related posttraumatic arthritis. The purpose of this study was to describe the features and report the early outcomes of THA in 4 patients who developed posttraumatic arthritis from gunshot injuries to their hips 2, 10, 18, and 26 years after their initial injury, respectively. All 4 patients underwent successful THA without complications. None of the patients had undergone a revision procedure at a mean 26-month (range, 12-48 months) follow-up. The authors believe that primary THA is a safe and effective procedure to reduce pain and improve function for gunshot-related posttraumatic arthritis in patients in whom nonoperative management failed.

Do Retained Pediatric Implants Impact Later Total Hip Arthroplasty?

It is debated whether all pediatric implants in the proximal femur should be removed in childhood. Hardware removal requires an additional surgical procedure and may put the child at risk for postoperative fracture. However, the impact of retained pediatric implants on future surgeries such as total hip arthroplasty (THA) is not well-understood. We undertook this case-control study to evaluate the effect of retained pediatric implants on surgical complexity and complications at the time of THA. This may offer insight as to whether pediatric proximal femoral implants should be removed in childhood. Case-control study. Between 1990 and 2007, 15,601 primary THAs were performed at a tertiary referral center. Of those, 31 hips had pediatric hardware that had been implanted at a mean of 31 years before the time of THA. Perioperative course and complications were compared with an age-matched, sex-matched, and BMI-matched cohort of 31 patients with no retained implants. Mean follow-up after arthroplasty was 7 years. Operative time was significantly longer in the retained implant group compared with the control group (230 vs. 159 min; P<0.0001), as was the hospital stay (5.2 vs. 3.8 d; P=0.02). Four of the 14 patients with retained plates required a strut allograft at the time of primary THA. Revision femoral stems and bone grafting were more frequently required in the retained implant cohort. Estimated blood loss was also higher in the retained implant cohort (886 vs. 583 mL; P=0.031). Seven patients in the retained hardware group had a major complication, including intraoperative fracture (5), bleeding (1), and nerve injury (1), whereas no patients in the control group sustained major complications (P=0.017). Retained pediatric implants removed at the time of THA were associated with increased operative time, length of stay, and risk of intraoperative fracture. This data supports routine removal of proximal femoral implants in pediatric patients with a high likelihood of future THA. III, case-control study.

Obesity and Operative Time in Primary Total Joint Arthroplasty

Obesity has been associated with osteoarthritis and increased morbidity and mortality. Most joint arthroplasty patients have a high body mass index (BMI). Some surgeons are reluctant to operate on obese patients due to technical difficulties and the anticipated higher complication rate. The purpose of this prospective study was to determine whether obesity is associated with longer operative times. We attended 100 consecutive primary total joint arthroplasties. Patients were divided into four groups depending on their BMI: the normal group (BMI: 18 to 24.9 kg/m2), the overweight group (BMI: 25 to 29.9 kg/m2), the obese group (BMI: 30 to 39.9 kg/m2), and the morbidly obese group (BMI ≥ 40 kg/m2). Anesthesia type and time, duration of surgery, time needed for scrubbing, draping, and transferring the patient to the operating table were all documented. The mean operative time for total hip arthroplasty (THA) was significantly increased in morbidly obese patients (R2 = 0.197, p = 0.003). The mean scrubbing time for total knee arthroplasty varied with BMI (p = 0.028). Time to administer spinal anesthesia was significantly increased in morbidly obese patients (R2 = 0.1466, p = 0.018). Morbid obesity is associated with a significant increase in the time needed to administer spinal anesthesia and the overall time needed to perform a THA.

Vascularised greater trochanter bone graft, combined free iliac flap and impaction bone grafting for osteonecrosis of the femoral head

To investigate the curative efficacy of osteonecrosis of the femoral head (ONFH) in a hip-preserving operative approach, by grafting a vascularized greater trochanter flap combined with a free iliac flap, in an attempt to seek an innovative approach for patients who suffered middle to late stage ONFH without total hip arthroplasty (THA) surgery. Our research included a total of 60 patients (66 hips) who accepted hip-preserving surgery by grafting a vascularized greater trochanter flap combined with a free iliac flap which was tightly filled by hammering because of ONFH (most were Association Research Circulation Osseous (ARCO) stage III patients) from January, 2006 to December, 2010. A Harris Hip Score was obtained during follow-ups, evaluating the clinical efficacy, X-rays were taken regularly for image assessing, and the SF-36 scale was used for estimating quality of life. Terminal observation time was considered when patients had symptom-dependant indications for performing another hip-preserving surgery or THA surgery. Fifty-eight patients (64 hips) were eventually contacted by telephone for an out-patient clinic return visit, with a mean follow-up time of 35.8 months (varied from 12 months to 60 months), but two patients lost contact for various reasons. The demographic data were as follows: there were 16 ARCO IIIA cases, 22 ARCO IIIB cases, and 26 ARCO IIIC cases, respectively. Postoperative X-rays revealed a well-repaired necrotic area of the femoral head and improvement of femoral-acetabulum coverage. The last follow-up mean Harris Hip Score was 86.56 ± 7.38 (excellent results reached 87.50%), which were greatly improved compared to 50.95 ± 6.86 pre-operatively. Also the postoperative mean scores of all dimensions of the SF-36 scale were improved to some extent. Additionally the physical component summary (PSC) scores were enhanced from 42 ± 13 pre-operatively to 78 ± 11, while the postoperative mental component summary (MCS) scores (76 ± 11) largely increased in contrast to pre-operative scores (51 ± 10), with both target indices having statistical significance (p = 0.005, p = 0.01), signifying hugely improvement of the quality of life of the patients. A correlation was found between Harris Hip Score and all dimensions of SF-36 scale (r = 0.32-0.72), especially closely correlated with physical functioning (PF), role-physical (RP) and bodily pain (BP) in PCS aspect (r = 0.72, p < 0.01; r = 0.58, p < 0.01; r = 0.65, p < 0.01, respectively). There is definite curative efficacy for the treatment of ONFH with an hip-preserving operative approach by grafting a vascularized greater trochanter flap combined with a free iliac flap which was tightly filled by hammering. This kind of operative approach reconstructs the biological stability of femoral head, which promotes repair of necrotic areas and indirectly preserves the femoral head of patients and a majority of hip function. It possesses vast clinical as well as practical significance, because the long-term efficacy can satisfy fundamental life requirements, especially for those young and middle-aged patients who suffer ONFH to avoid or put off the time of total hip arthroplasty (THA) surgery.

Abductor mechanism tears in primary total hip arthroplasty

Tears of the abductor mechanism of the hip are well recognized, but poorly understood. Little is known of the effect of demographics and pathology on prevalence of abductor mechanism tears or the impact on clinical outcome. This prospective study analysed the effect of age, gender, medical co-morbidity and social deprivation on prevalence of abductor mechanism tears of the hip in 835 consecutive patients undergoing total hip arthroplasty (THA) between 2003 and 2011. Effect on clinical outcome relating to presence of abductor mechanism tear was analysed in a subset at pre-op and at 1 year post-operation using the Oxford hip score (OHS). The prevalence of abductor mechanism tears was 25.4 % (n = 212). Female patients (p < 0.001), older patients (p = 0.001) and those of lower socioeconomic status (p < 0.001) were significantly more likely to have a pre-operative abductor mechanism tear. In older socially deprived females the predicted rate of tear is 70.9 %. The aetiology of the hip disease (p = 0.593) or presence of any specific co-morbidity (p = 0.085-0.929) had no significant effect on the prevalence of abductor mechanism tears. In patients with protrusion or dysplasia there was an increased prevalence of tears (p = 0.002). There was no significant difference in pre-operative (p = 0.775) or post-operative (p = 0.604) OHSs regardless of the tears when the tears were recognized and treated at the time of THA. Tears are increasingly prevalent in women of advancing years and lower socioeconomic status which should be considered when planning operative approach in this demographic. When recognised and repaired there is no difference in the clinical outcome for those with abductor mechanism tears of the hip.

Die Ausbildung von Knochengewebe an der Oberfläche von hydroxylapatitbeschichteten Prothesenschäften: eine radiologische Analyse

To facilitate implant osseointegration in the early postoperative period, coating of the implant surfaces with osseoconductive materials, e.g. hydroxyapatite (HA), is being increasingly recommended. It apparently reduces the rate of radiolucent lines and even improves the osseointegration of implants less well suited for cementless anchorage. We analysed HA-coated stems to find out whether newly formed bone adherent to the implant surface such as seen on explanted stems is also seen on radiographs and whether it follows a specific morphological pattern. We also wanted to know whether newly formed peri-implant bone extends over the entire length of the HA-coating, at which point in time it is seen radiographically and whether it expands within the first few years post implantation by radiological evidence. Radiographs of 40 unselected patients after primary total hip arthroplasty (THR), 14 males and 26 females, aged 44.4 to 86.7 years at the time of THR, with a mean age of 67.3 years were available for analysis. Monitor-guided a.-p. and axial views of the stems were obtained in the early postoperative period up to 6 weeks post THR, at a mean follow-up time of 1.3 (1.0 to 1.8) years and 3.0 (1.9 to 3.7) years. Tapered straight stems with a rectangular cross-section made of a wrought Ti6AI7Nb alloy with an HA coating in the proximal third were used. A.-p. views: At one year there were no signs suggesting an increased ongrowth of bone. At 3 years, on average, delicate bony appositions were seen on the implant surfaces in position 1 in three stems, in one of them also in position 7. These looked like a sclerotic zone lacking a sharp demarcation and were in direct contact with the implants without any bone-to-implant gaps. Axial views: At about one year two stems showed delicate bony appositions parallel to the implant surface in the proximal part in positions 8 and 9 as well as 13 and 14. Named "miniscleroses" by us, these structures were confined to the length of the HA coating. At three years these miniscleroses were clearly visible around 11 stems (more than 25 %). Those already seen at one year were much better defined at three years, but still confined to the HA-coated part of the stem. Some of them were poorly demarcated from the adjacent bone and medullary canal and some showed smooth demarcations. The density of the bony ongrowths was either homogeneous or increased from the medullary space or adjacent bone towards the implant surface. All of them were adherent to the implant surface. While not related to the peri-implant cortical bone, they were in contact with trabecular structures. After a mean follow-up time of one year radiolucent lines were seen around four stems in positions 1, 7 and 8. These were up to 1 mm in size around two stems and 2 mm or more in the other two. At 3 years all of the visible radiolucencies had disappeared except for one measuring 1 mm in position 8. The structures we found radiographically apparently reflect newly formed bone along the entire HA-coated implant surface. Most of them were located in positions 8, 9 and 13, 14. They provide visible evidence of osseointegration at osseoconductive surfaces. As they apparently did not have any contact with the peri-implant bone, they appear to be compatible with the bilateral osteogenesis according to Osborn. The effects of the rapid bony ongrowth on HA-coated surfaces and the striking absence of radiolucencies on the long-term outcome are still speculative. But the structures seen may be taken as a sign of improved implant stability by rapid osseointegration and of early sealing of the medullary canal. As a result, wear particles of the articulating surfaces are barred from spreading to the medullary cavity of the femur. This alone argues in favour of using coated implants throughout. However, more studies are needed to shed light on these issues.

Body mass index as a risk factor for mis-seating of ceramic liners in total hip arthroplasty

Background A retrospective radiographic review was undertaken to determine the prevalence of mis-seated ceramic liners in primary total hip arthroplasty and the association between body mass index and mis-seating risk. Methods Patients with primary implantation of the Trident (Stryker, Mahwah, NJ) uncemented ceramic acetabular component were identified from a prospective database of 2227 primary total hip arthroplasties and radiographically reviewed. All procedures were performed at one center between 1999–2006. The mis-seating angle and location were determined. The risk of mis-seating by body mass index was calculated using logistic regression models. Results A total of 411 primary total hip arthroplasties were identified. Mis-seating occurred in 81 patients (19.7%). Of the 411 total hip arthroplasties, 83 (20.2%) were performed in patients with a body mass index of less than 25.0 defined as underweight to normal, 133 (32.4%) in patients who were overweight with a body mass index between 25.0–29.9, and 195 (47.4%) in patients who were obese with a body mass index of over 30.0. Adjustment for case mix revealed a significant association between body mass index and risk of mis-seating of ceramic components. Patients who were overweight at the time of total hip arthroplasty (body mass index 25.0–29.9) were at increased risk of mis-seating (adjusted odds ratio 2.52, 95% confidence interval (1.24-5.12, P=0.01). Conclusions Mis-seating of ceramic acetabular systems in total hip arthroplasty was a frequent occurrence. Patients who were overweight were more than two times more likely to suffer mis-seating than those who were underweight, of normal weight, or obese.

Ten-Year Results After Cementless THA with a Sandwich-Type Alumina Ceramic Bearing

We analyzed the long-term results of a single-surgeon series of 102 cementless total hip arthroplasties (THAs) performed using a sandwich-type alumina ceramic bearing. The prostheses involved a porous-coated acetabular socket, a polyethylene-alumina composite liner, a 28-mm alumina head, and a grit-blasted titanium-alloy stem. Mean patient age at the time of THA was 39 years (range, 18-66 years), and 76% of the patients were younger than 50 years. All procedures were performed with use of the same surgical technique and the same implant at a single center. Mean follow-up was 115 months (range, 84-133 months). When failure was defined as revision of either the acetabular or the femoral component for any reason, Kaplan-Meier survival probability at 10 years was 95.3% (95% confidence interval, 89.5%-100%). Mean Harris Hip Score improved from 47 points (range, 16-70 points) preoperatively to 95 points (range, 85-100 points) at final follow-up. No radiographically detectable osteolysis around the acetabular or femoral component was observed in any hip. No patient reported squeaking in the operated hip. During the follow-up period, 3 hips (3%) required revision surgery; 2 underwent acetabular revision because of a ceramic liner fracture and 1 underwent revision for early loosening of the acetabular cup. Ten-year results of cementless THA with a sandwich-type alumina ceramic bearing were encouraging, and no great increase in ceramic failure rate was observed, which contrasts with the findings of previously reported short-term follow-up studies.

Uncemented total hip arthroplasty in chronic hemodialysis patients

Background and purpose Whether or not uncemented total hip arthroplasty (THA) can achieve durable fixation of implants to bone in patients on chronic hemodialysis is unknown. We analyzed the 2–13-year clinical outcomes of cementless THA in patients with end-stage renal diseases who were maintained on long-term hemodialysis.Patients and methods We reviewed the outcome of 23 consecutive uncemented THAs undertaken between 1993 and 2004, in patients with chronic renal failure who had been on long-term hemodialysis (2–18 years). 1 patient died and 2 patients were lost to follow-up within 2 years, leaving 20 hips (20 patients, median age 66 (38–81) years at the time of THA, 11 females) that were reviewed at median 7 (2–13) years postoperatively.Results Radiographic bone-ingrowth fixation of the components was found in 19 patients. 1 patient had aseptic loosening requiring revision surgery. The median d'Aubigne and Postel score was 10 (8–14) preoperatively and 15 (12–18) at final review. No prosthetic infections were found in any of the patients.Interpretation Uncemented THA shows promising medium-term results in patients receiving long-term hemodialysis.

Total Hip Arthroplasty for Alcoholic Osteonecrosis of the Femoral Head

Osteonecrosis of the femoral head in the setting of alcohol abuse is a potential important cause of symptomatic hip disease in young patients. All cases of uncemented primary total hip arthroplasty (THA) with a primary operative diagnosis of osteonecrosis of the femoral head secondary to alcohol abuse treated at our institution from January 1990 to February 2002 were identified. Twenty-three patients with 28 hips were identified; all patients had advanced disease (subchondral collapse) that was unresponsive to conservative treatment modalities. Within 5 years of index THA, 2 patients were lost to follow-up, and 2 patients died from causes unrelated to their surgery. The remaining 19 patients underwent 24 THAs. Unilateral THA was performed in 14 patients, and bilateral THA was performed in 5 patients. Seventeen men and 2 women with an average age of 41.8 years (range, 30-59 years) at the time of THA were included in the study. The average duration to clinical follow-up was 7.6 years. There was significant improvement in hip pain and hip function scores. Seven THAs were revised at a mean 6.7 years following index THA. Five- and 10-year implant survivorship free of revision was 96% and 64%, respectively (Kaplan-Meier Survivorship Analysis). The continued use of alcohol was associated with a slightly increased risk of failure (61% implant survivorship at 10 years in those with continued alcohol intake vs 75% 10-year survivorship in those without).

Increasing Operating Room Throughput

Increasing Operating Room Throughput

Stability Advantages of a Modular Total Hip System

Hip instability continues to be an infrequent, yet frustrating complication of total hip arthroplasty (THA). Restoration of normal hip anatomy and biomechanics at the time ofTHA is critical to reduce the risk of dislocation. This can be difficult in some patients due to distorted hip anatomy and wide variations in "normal" hip anatomy reported in numerous studies. Modular femoral components offer a large array of femoral offset, length, and version options which can be used independently or in combination to recreate normal osseous anatomy and a well-tensioned soft tissue envelope, which should enhance hip stability following THA.

Total Hip Arthroplasty with Bulk Femoral Head Autograft for Acetabular Reconstruction in DDH

BACKGROUND: The long-term results of total hip arthroplasty performed with cement and use of a bulk autograft for acetabular reconstruction in patients with developmental dysplasia of the hip have varied considerably. We evaluated the results of total hip arthroplasties performed with acetabular bulk autograft to identify the factors that influence the results of this procedure. METHODS: Acetabular roof defects secondary to developmental dysplasia of the hip were reconstructed with a bulk femoral head autograft at the time of total hip arthroplasties performed with use of the Charnley technique and prosthesis. Thirty-seven hips in thirty patients (mean age at the time of the operation, fifty-seven years) were followed for ten to twenty-six years (mean, nineteen years). The Crowe classification of hip subluxation or dislocation was Group II for sixteen hips, Group III for seventeen, and Group IV for four. RESULTS: Coverage of the socket by the graft ranged from 5% to 49% (mean, 33%). Twenty-nine sockets were located within the true acetabulum, and eight were placed more proximally. At the time of the latest follow-up, all of the patients had an excellent clinical result, all of the grafts had united, and no hip had radiographic evidence of failure of the fixation. CONCLUSIONS: We found that total hip arthroplasty performed with cement and use of a bulk autograft to reconstruct an acetabulum with severe bone deficiency secondary to developmental dysplasia of the hip can provide long-term success in patients forty-eight years of age and older when coverage of the socket by the graft does not exceed 50%. When it is not possible to achieve >50% coverage of the socket by the ilium at the level of the true acetabulum, more proximal placement of the socket to obtain adequate coverage is recommended.

TOTAL HIP ARTHROPLASTY WITH BULK FEMORAL HEAD AUTOGRAFT FOR ACETABULAR RECONSTRUCTION IN DEVELOPMENTAL DYSPLASIA OF THE HIP

The long-term results of total hip arthroplasty performed with cement and use of a bulk autograft for acetabular reconstruction in patients with developmental dysplasia of the hip have varied considerably. We evaluated the results of total hip arthroplasties performed with acetabular bulk autograft to identify the factors that influence the results of this procedure. Acetabular roof defects secondary to developmental dysplasia of the hip were reconstructed with a bulk femoral head autograft at the time of total hip arthroplasties performed with use of the Charnley technique and prosthesis. Thirty-seven hips in thirty patients (mean age at the time of the operation, fifty-seven years) were followed for ten to twenty-six years (mean, nineteen years). The Crowe classification of hip subluxation or dislocation was Group II for sixteen hips, Group III for seventeen, and Group IV for four. Coverage of the socket by the graft ranged from 5% to 49% (mean, 33%). Twenty-nine sockets were located within the true acetabulum, and eight were placed more proximally. At the time of the latest follow-up, all of the patients had an excellent clinical result, all of the grafts had united, and no hip had radiographic evidence of failure of the fixation. We found that total hip arthroplasty performed with cement and use of a bulk autograft to reconstruct an acetabulum with severe bone deficiency secondary to developmental dysplasia of the hip can provide long-term success in patients forty-eight years of age and older when coverage of the socket by the graft does not exceed 50%. When it is not possible to achieve >50% coverage of the socket by the ilium at the level of the true acetabulum, more proximal placement of the socket to obtain adequate coverage is recommended.

Trabecular minimodeling in human iliac bone

In adult human beings, remodeling creates nearly all of new bone tissue. However, Frost hypothesized that modeling can go on in trabeculae throughout life. As this hypothesis has not been verified, we looked for histologic evidence of trabecular modeling (minimodeling) during bone histomorphometry of transiliac bone biopsy specimens obtained from 34 patients (age range, 38–81 years; mean age, 58.4 years; female, 31/34) at the time of total hip arthroplasty. Before the bone biopsy study, we performed quantitative bone scintigraphy of bilateral hip joints and bilateral iliac crests in 10 other patients with unilateral hip disease and confirmed that the bone biopsy site was not affected by ipsilateral hip joint disease. Patients who had metabolic bone diseases or who had taken medications known to affect bone metabolism were excluded from the study. During modeling where bone formation and bone resorption are not coupled, bone formation can occur on quiescent bone surfaces without preceding bone resorption and create smooth cement lines. Therefore, the combination of fluorochrome labeling and a smooth cement line without interruption of surrounding collagen fibers was regarded as evidence of minimodeling. Histologic evidence of minimodeling was detected in 21 of the entire 34 specimens (62%) and 17 of 27 specimens obtained from postmenopausal patients (63%). Bone volume of minimodeling sites was less than 1% of the trabecular bone volume, and these sites accounted for less than 2% of the entire bone surface on average. However, osteoid volume of minimodeling sites comprised approximately one-tenth of the entire osteoid volume, and their labeled surface constituted one-fourth to half of the entire labeled surface on average. Therefore, when performing bone histomorphometry of adult cancellous bone, minimodeling should be taken into account when dealing with parameters related to osteoid volume and mineralization. A comparison of specimens with and without minimodeling demonstrated that the presence of minimodeling was correlated with smaller physique of patients, accelerated mineralization (as indicated by the higher mean MS/BS and MAR values and the shorter mean Omt), and higher metabolic turn-over of bone (as indicated by the higher mean BFR/BV value). Although the findings still need to be verified in a larger number of normal subjects without hip joint disease, they support Frost’s hypothesis that minimodeling can continue throughout human life.

Effect of baseline functional status and pain on outcomes of total hip arthroplasty.

It is unknown whether there is an optimal time for surgery-that is, whether waiting until a patient has greater disability results in a worse outcome. We examined the effect of baseline status on the outcome of total hip arthroplasty to determine if such a relationship existed. All Medicare patients undergoing total hip arthroplasty for osteoarthritis in twelve states were identified by the fiscal intermediary beginning in October 1994 and continuing for approximately eight months; 1640 eligible patients were identified. Consenting patients were surveyed within two months after the procedure and again at twelve months after the procedure, and their medical records were reviewed. The baseline survey, completed by 1120 patients, included items regarding the level of activity, the presence and severity of pain with walking, the need for assistance for walking, the distance that the patient could walk, and whether the patient could perform Instrumental Activities of Daily Living (IADLs). Data on comorbid diagnoses were collected from the medical records. Patients with pain during walking at baseline were more likely to have pain at one year than those without pain at baseline (21% compared with 9%; p < 0.05). Patients who needed assistance with walking at baseline were more likely to need assistance at one year than those who did not need assistance at baseline (38% compared with 15%; p < 0.01). Similar results were seen with regard to the need for assistance with housework (39% compared with 18%; p < 0.01) and grocery shopping (37% compared with 14%; p < 0.01) and, to a lesser extent, for overall participation in moderate activity (17% compared with 10%; p < 0.01). These results persisted after controlling for comorbidities in a multiple regression equation. However, the worse a patient's preoperative status, the more he or she gained in all four measures (p < 0.01). The findings of the present study suggest that the worse a patient's preoperative status, the more he or she may benefit from total hip arthroplasty. However, our findings also suggest that patients who have a worse preoperative status may not have as good an outcome as those who have a better preoperative status. Patients and physicians should consider these findings when discussing the timing of total hip arthroplasty.