Results Of Total Hip Replacement Research Articles

Total Hip Replacement with the CLS Expansion Shell and a Structural Femoral Head Autograft for Patients with Congenital Hip Disease

Reconstruction of a dysplastic acetabulum in a patient with osteoarthritis of the hip may be accomplished with a variety of surgical techniques. The aim of our study was to assess the outcomes of total hip replacement with the uncemented CLS expansion shell and a structural femoral head autograft to augment the deficient acetabulum in patients with osteoarthritis secondary to congenital hip disease. Between 1990 and 1994, we used a CLS expansion shell with a structural femoral head autograft in forty-three consecutive patients (forty-three hips) with osteoarthritis secondary to congenital hip disease. The ratio of male to female patients was 5:38, and the mean age of the patients was forty-eight years. According to the preoperative radiographic assessment, the dysplasia was categorized as Crowe type I in six patients, Crowe type II in thirty-one patients, and Crowe type III and type IV in three patients each. No patient was lost to follow-up. The mean duration of follow-up was 120 months. Plain radiographs were made immediately after surgery and at the latest follow-up evaluation. Clinical outcomes were determined with use of the Harris hip score and the Merle d'Aubigné and Postel score, and a radiographic analysis was performed. Postoperatively, the mean Harris hip score had improved 58 points for patients with Crowe type-I and II dysplasia, 47 points for patients with Crowe type-III dysplasia, and 46 points for patients with Crowe type-IV dysplasia (p < 0.05 for all). At the latest follow-up examination, the mean Harris hip score for all patients was 92.6 points. The mean Merle d'Aubigne and Postel score was 8.3 points preoperatively and 15.8 points at the time of the latest follow-up. The mean coverage of the shell by the graft immediately after surgery was 32.2%. Osteointegration of the CLS expansion shell was evident radiographically in all forty-three hips at the latest follow-up evaluation. There were no failures of the bone grafts. Clinical survival of the CLS expansion shell with a structural femoral head autograft was 100% at a mean of ten years after surgery. The rate of survival of the shell, with radiographic signs of loosening as the end point, was 88.2% at ten years. The CLS uncemented expansion shell, when used with a structural femoral head autograft, provides a reliable reconstruction, augments deficient acetabular bone stock, and allows placement of the socket at or close to the anatomic center of hip rotation in patients undergoing total hip arthroplasty to treat the sequelae of congenital hip disease.

TOTAL HIP REPLACEMENT WITH THE CLS EXPANSION SHELL AND A STRUCTURAL FEMORAL HEAD AUTOGRAFT FOR PATIENTS WITH CONGENITAL HIP DISEASE

Background: Reconstruction of a dysplastic acetabulum in a patient with osteoarthritis of the hip may be accomplished with a variety of surgical techniques. The aim of our study was to assess the outcomes of total hip replacement with the uncemented CLS expansion shell and a structural femoral head autograft to augment the deficient acetabulum in patients with osteoarthritis secondary to congenital hip disease. Methods: Between 1990 and 1994, we used a CLS expansion shell with a structural femoral head autograft in forty-three consecutive patients (forty-three hips) with osteoarthritis secondary to congenital hip disease. The ratio of male to female patients was 5:38, and the mean age of the patients was forty-eight years. According to the preoperative radiographic assessment, the dysplasia was categorized as Crowe type I in six patients, Crowe type II in thirty-one patients, and Crowe type III and type IV in three patients each. No patient was lost to follow-up. The mean duration of follow-up was 120 months. Plain radiographs were made immediately after surgery and at the latest follow-up evaluation. Clinical outcomes were determined with use of the Harris hip score and the Merle d'Aubigné and Postel score, and a radiographic analysis was performed. Results: Postoperatively, the mean Harris hip score had improved 58 points for patients with Crowe type-I and II dysplasia, 47 points for patients with Crowe type-III dysplasia, and 46 points for patients with Crowe type-IV dysplasia (p < 0.05 for all). At the latest follow-up examination, the mean Harris hip score for all patients was 92.6 points. The mean Merle d'Aubigné and Postel score was 8.3 points preoperatively and 15.8 points at the time of the latest follow-up. The mean coverage of the shell by the graft immediately after surgery was 32.2%. Osteointegration of the CLS expansion shell was evident radiographically in all forty-three hips at the latest follow-up evaluation. There were no failures of the bone grafts. Clinical survival of the CLS expansion shell with a structural femoral head autograft was 100% at a mean of ten years after surgery. The rate of survival of the shell, with radiographic signs of loosening as the end point, was 88.2% at ten years. Conclusions: The CLS uncemented expansion shell, when used with a structural femoral head autograft, provides a reliable reconstruction, augments deficient acetabular bone stock, and allows placement of the socket at or close to the anatomic center of hip rotation in patients undergoing total hip arthroplasty to treat the sequelae of congenital hip disease. Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.

CEMENTLESS TOTAL HIP ARTHROPLASTY AND LIMB-LENGTH EQUALIZATION IN PATIENTS WITH UNILATERAL CROWE TYPE-IV HIP DISLOCATION

Background: Total hip arthroplasty in patients with unilateral congenital high dislocation of the hip (Crowe type IV) presents many challenges, including the problem of a marked limb-length discrepancy. The purpose of this retrospective study was to analyze the results of total hip replacement with limb-length equalization in these patients. Methods: From 1988 to 1996, fifty-six patients (forty-seven women and nine men) with unilateral Crowe type-IV dislocation of the hip were treated with a cementless total hip arthroplasty at a mean age of 35.4 years. The preoperative limb-length discrepancy averaged 4.9 cm. Prior to the total hip arthroplasty, forty-eight patients with a limb-length discrepancy of >4.0 cm underwent iliofemoral distraction with use of an external fixator for eight to seventeen days. The acetabular cup was placed in the anatomical position in every patient. Shortening femoral osteotomies were not required. Results: The iliac fixator pins loosened in six patients. No patient had a pin-site infection, hip joint infection, or nerve palsy. At the time of follow-up, at an average of 147.2 months, the Harris hip score averaged 90.2 points. Overall, the mean lengthening after the total hip arthroplasty was 4.6 cm. There were no revisions of the femoral stem. Nine cups were revised, four because of polyethylene wear and five because of loosening. Conclusions: We were able to safely place the acetabular cup at the anatomical position without femoral shortening by bringing the femoral head to the normal level preoperatively; thus, we could restore nearly normal limb length. We believe that our twelve-year results are similar to those of total hip arthroplasty in patients without dysplasia. Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.

Cementless Total Hip Arthroplasty and Limb-Length Equalization in Patients with Unilateral Crowe Type-IV Hip Dislocation

Total hip arthroplasty in patients with unilateral congenital high dislocation of the hip (Crowe type IV) presents many challenges, including the problem of a marked limb-length discrepancy. The purpose of this retrospective study was to analyze the results of total hip replacement with limb-length equalization in these patients. From 1988 to 1996, fifty-six patients (forty-seven women and nine men) with unilateral Crowe type-IV dislocation of the hip were treated with a cementless total hip arthroplasty at a mean age of 35.4 years. The preoperative limb-length discrepancy averaged 4.9 cm. Prior to the total hip arthroplasty, forty-eight patients with a limb-length discrepancy of >4.0 cm underwent iliofemoral distraction with use of an external fixator for eight to seventeen days. The acetabular cup was placed in the anatomical position in every patient. Shortening femoral osteotomies were not required. The iliac fixator pins loosened in six patients. No patient had a pin-site infection, hip joint infection, or nerve palsy. At the time of follow-up, at an average of 147.2 months, the Harris hip score averaged 90.2 points. Overall, the mean lengthening after the total hip arthroplasty was 4.6 cm. There were no revisions of the femoral stem. Nine cups were revised, four because of polyethylene wear and five because of loosening. We were able to safely place the acetabular cup at the anatomical position without femoral shortening by bringing the femoral head to the normal level preoperatively; thus, we could restore nearly normal limb length. We believe that our twelve-year results are similar to those of total hip arthroplasty in patients without dysplasia.

The “Oxford Heup Score”

Background The evaluation of a total hip prosthesis would be most complete if the opinion of the patient, surgeon and the radiographs are combined. Disease specific patient outcome questionnaires are scarce, especially in Dutch.Methods The disease-specific 12-item questionnaire on the perception of patients with total hip replacement was translated into Dutch. We also investigated the extra value of two specific hip items, “the need for walking aids” and “sexual problems because of the hip”, four general items on overall satisfaction and one question about patient classification. The 14 hip-specific items were each scored from 1 (least difficulties) to 5 (most difficulties). The Dutch translation, the “Oxford Heup Score” (OHS) was tested on psychometric quality in a multicenter prospective study.Results The psychometric results of the OHS proved to be adequate. In the first postoperative year the score was very sensitive to changes, whereas in the second year it did not change significantly. The two added hip-specific questions were both filled out positively by more than 50% of the patients and thus fit perfectly into a hip-specific patient outcome questionnaire such as the OHS.Interpretation The OHS proves to be an appropriate instrument for assessment of the outcome of total hip replacement from the patient's perspective. Together with the judgement of the surgeon, it provides useful insights into the question of whether this operation has been a success or not.

Primary total hip replacement for acute displaced subcapital femoral fractures with a minimal three-year follow-up

The aim of the study was to review the results of total hip replacement (THR) in relatively fit and mobile patients with Garden 3 and 4 fractures of the neck of femur. Forty-one patients who underwent THR for displaced intracapsular hip fractures from 1993 to 2001 were reviewed. Only those patients with three years or more follow-up were reviewed. Average follow-up was 5.8 years (3-9.6 years). Complications encountered were: minor wound dehiscence (1), DVT (3), pulmonary embolism (1), dislocation (1), per-operative femur fracture (1), periprosthetic fracture following repeat fall (2), stem loosening (1). Average Harris Hip score at follow-up was 91 (66-100). We recommend total hip replacement as the primary treatment in relatively fit and mobile patients with displaced intracapsular fractures of the hip. (Hip International 2005; 15: 33-7).

Primary total hip replacement for acute displaced subcapital femoral fractures with a minimal three-year follow-up.

The aim of the study was to review the results of total hip replacement (THR) in relatively fit and mobile patients with Garden 3 and 4 fractures of the neck of femur. Forty-one patients who underwent THR for displaced intracapsular hip fractures from 1993 to 2001 were reviewed. Only those patients with three years or more follow-up were reviewed. Average follow-up was 5.8 years (3-9.6 years). Complications encountered were: minor wound dehiscence (1), DVT (3), pulmonary embolism (1), dislocation (1), per-operative femur fracture (1), periprosthetic fracture following repeat fall (2), stem loosening (1). Average Harris Hip score at follow-up was 91 (66-100). We recommend total hip replacement as the primary treatment in relatively fit and mobile patients with displaced intracapsular fractures of the hip. (Hip International 2005; 15: 33-7).

Assessment of Results of Total Hip Replacement Using SFEN Implants (preliminary report)

From January 1999 to August 2004 total hip replacement with cement SFEN-C implants was performed in 113 patients (128 joints). Average age of patients at surgery was 65.5 years (from 21 to 87). Results were evaluated 3, 6, 12 months after operation and then yearly. At control examination pelvic radiography, assessment of cement technique by Barrack, dynamics of radiographic density at the metal-cement borders, cement-bone of femoral component by Gruen as well as acetabular component by DeLee and Charnley were performed. Functional result was evaluated by Merle d'Aubigne and Postel systems in modification by Charnley and by Harris. Mean follow-up was 20.3+10.8 months (from 3 to 68 months). Long-term results were studied in 87 patients. No sings of polyethylene shell wear and acetabular and proximal femur osteolysis were detected. No clinical symptoms of instability requiring re-operation were noted.

Total Resurfacing for Osteonecrosis of the Hip

With the resurgence of metal-on-metal bearings, there is renewed interest in total hip resurfacing. A cementless acetabular component used for resurfacing with a wall thickness of fewer than 5 mm is comparable in size to acetabular components used for total hip replacement. The fixation of a porous-ingrowth acetabular component used for resurfacing has been shown to be reliable and durable. There are few clinical reports of total hip resurfacing that stratify results by diagnosis. However, available evidence indicates that the pain relief, function, and activity after total hip resurfacing for osteonecrosis are superior to the results reported for hemiresurfacing and similar to the results of total hip replacement. Femoral-side failure is the main issue occurring with total resurfacing for osteonecrosis, and the femoral side failure rate is higher than that of hemiresurfacing. There are no simple guidelines for the extent of femoral head necrosis that are compatible with successful resurfacing. Refined patient selection and surgical technique can improve the outcomes and durability of total hip resurfacing for osteonecrosis.

Calcium phosphate drug delivery system: influence of local zoledronate release on bone implant osteointegration

Despite total hip replacement (THR) gives generally satisfactory results, the quality of outcome in young patients is markedly decreased compared to the average THR outcome. For this population, pharmacological treatment with bisphosphonate would be beneficial to decrease the peri-implant osteolysis. However, as this population does not necessarily suffer from osteoporosis, a nonsystemic treatment would be preferable. Zoledronate was then grafted to hydroxyapatite (HA) coating of titanium implants. The implants were inserted in rat condyles with various zoledronate concentrations. A positive concentration-dependent effect was observed on the peri-implant bone density and on different histomorphometric parameters. Importantly for the outcome of the implants, the mechanical fixation was increased by the local presence of zoledronate.The obtained results open the way of an easy transformation of currently existing HA-coated implants by grafting bisphosphonate onto the coating in order to increase their service life in the patients.

Orientation of the femoral component in surface arthroplasty of the hip. A biomechanical and clinical analysis.

Although the orientation of the femoral component has been shown to influence the outcome of total hip replacement, its effect on the clinical outcome of surface arthroplasty has not been studied, to our knowledge. The purpose of this study was to examine the relationship between femoral component positioning and the outcome of a surface arthroplasty of the hip. We reviewed the results of ninety-four hybrid metal-on-metal surface arthroplasties in patients who were forty years old or younger at the time of the operation and were followed for a minimum of two years or until the prosthesis failed. Measurements of the hip reconstruction were made on the anteroposterior pelvic radiograph. The correlation between the orientation of the femoral component and the outcome of the arthroplasty was evaluated, as were stresses within the resurfaced femoral head as a function of the orientation of the femoral component. The mean duration of follow-up was 4.2 years. Thirteen hips had an adverse outcome, defined as conversion to a total hip replacement, radiolucency of >1 mm in thickness adjacent to the femoral stem, or narrowing of the femoral neck of >10%. The mean femoral stem-shaft angle in the coronal plane was 138 degrees, with the hips that had an adverse outcome having a significantly lower mean angle than the rest of the cohort (133 degrees compared with 139 degrees, p = 0.03). Hips with an angle of <or=130 degrees had an increase in the relative risk of an adverse outcome by a factor of 6.1 (p < 0.004). In the entire cohort, stresses in the superior aspect of the resurfaced femoral head were substantially lower during slow walking than they were during fast walking (7.1 N/mm(2) compared with 14.2 N/mm(2)). Optimizing the femoral stem-shaft angle toward a valgus orientation during the preparation of the femoral head is important when a hip is being reconstructed with a surface arthroplasty because the resurfaced hip transmits the load through a narrow critical zone in the femoral head-neck region and the valgus angulation may reduce these stresses.

Total hip arthroplasty for congenital hip disease.

It is generally agreed that the clinical and radiographic results of total hip replacement performed for degenerative arthritis secondary to congenital hip disease vary depending on the severity of the anatomical abnormality. In this study, we report the mid-term and long-term clinical and radiographic results of total hip arthroplasty performed for each of the three different types of congenital hip disease. Between 1976 and 1994, the senior author performed 229 consecutive primary total hip arthroplasties in 168 patients with osteoarthritis secondary to congenital hip disease. Seventy-six hips were dysplastic, sixty-nine had a low dislocation, and eighty-four had a high dislocation. The Charnley low-friction technique was performed in 178 hips, and the so-called hybrid technique was performed in forty-six hips. Cementless arthroplasty was used in only five hips. After a minimum of seven years of follow-up, the rates of revision of the acetabular components were 15% in the dysplastic hips, 21% in the hips with a low dislocation, and 14% in those with a high dislocation. The rates of revision of the femoral components were 14%, 14%, and 16%, respectively. Survivorship analysis predicted an overall rate of prosthetic survival at fifteen years of 88.8% +/- 4.8% in the dysplastic hips, 73.9% +/- 7.2% in the hips with a low dislocation, and 76.4% +/- 8.1% in those with a high dislocation. An understanding of the anatomical abnormalities and the use of appropriate techniques and implants make total hip arthroplasty feasible for treatment of the three types of congenital hip disease. In patients with a low dislocation, the major technical problem is reconstruction of the natural acetabulum. In those with a high dislocation, the challenge is to place the acetabular component inside the reconstructed true acetabulum and to use an appropriate femoral implant in the hypoplastic narrow femoral diaphysis.

Developmental hip dysplasia treated with total hip arthroplasty with a straight stem and a threaded cup.

Operative strategies to overcome the anatomical anomalies in patients with osteoarthritis secondary to developmental dysplasia of the hip remain controversial. The objective of this study was to determine the outcomes of total hip replacement with a grit-blasted cementless threaded cup and a cementless straight stem in patients with developmental dysplasia. Ninety-three patients with developmental hip dysplasia who had been treated with a total of 121 cementless total hip arthroplasties were clinically assessed at a mean of 9.3 years. The acetabular reconstruction was done with a cementless threaded cup, which was medialized to ensure that at least one thread was anchored in the bone in order to achieve good primary stability. All radiographs were analyzed retrospectively. Kaplan-Meier survivorship analysis, with radiographic evidence of aseptic loosening as the end point, predicted a survival rate of 97.5% for the acetabular component and 100% for the femoral stem at 9.3 years. The average Harris hip score for the unrevised hips improved from 34.0 points preoperatively to 84.1 points at the latest follow-up evaluation. The average total volume of polyethylene wear at the time of final follow-up was 73.6 mm(3). These wear and loosening rates demonstrate that very good results were achieved in this relatively young patient population when the hip joint center had been properly restored, even when a small cup with a thin polyethylene liner had been used.

Cemented bipolar hemiarthroplasty for displaced intracapsular fracture in the mobile active elderly patient

Fifty-three patients who were independently mobile outside their home at the time of a displaced intracapsular fractured neck of femur were reviewed at a mean follow-up of 32 months after treatment with a cemented bipolar hemiarthroplasty. Forty-four had no or mild pain. Eleven of the sixteen able to walk 1 mile before fracture were able to do so at review, once significant co-morbidity was excluded. There were no dislocations. Two had been revised, one for technical failure. These results are significantly better than would be expected with conventional hemiarthroplasty in this group of patients. They are comparable with results of total hip replacement (THR) but without the risk of dislocation. Patients able to walk 1 mile before fracture regained their pre-fracture mobility significantly better than those able to walk 500 yards. We suggest that ability to walk 1 mile should define the mobile active elderly for future studies and in guiding treatment.

Rasch scoring of outcomes of total hip replacement

We examined whether there are advantages in terms of outcome assessment of using Rasch methods of scoring the 12-item Oxford Hip Score questionnaire over conventionally summed scores. Data were collected on patients receiving total hip replacement surgery. Three patient groups were created according to surgery type: primary, revision, and re-revision; two groups were created according to satisfaction with surgery: very satisfied and dissatisfied. Analyses were performed to test the relative precision (RP) of Rasch scoring versus conventionally summed scores in discriminating the groups experiencing different types of surgery and level of satisfaction. At the 1-year follow-up, RP ratios favored the Rasch scoring method in both tests of discrimination. Considerable gains in precision were achieved with Rasch scoring methods when groups were compared in a cross-sectional way. Alternative approaches to scoring questionnaires should be investigated to better assess comparisons over time.

Endoprosthesis in paraplegics with periarticular ossification of the hip.

Clinical study. To evaluate indications of hip endoprosthesis in periarticular ossifications. A Spinal Cord Injury Centre in Germany. Clinical examination, X-ray control. Surgery of periarticular ossification (paraosteoarthropathy, POA) either involves simple resection of the ossification or removal of the hip. The latter has an impact on the sitting posture with concomitant increased pressure sore risk. Nevertheless the hip is biomechanically important in paraplegics. We are investigating the outcome of total hip replacement (THR) in patients with ankylosis due to periarticular ossification. Six hip replacement cases seen in follow-up of up to 24 months showed no loosening, with good mobility of the joint. We follow a strict perioperative POA prophylaxis, which resulted in each case reporting only a slight recurrence (Brooker 1-2) without any loss of functional mobility. In ankylotic hips with mobility/social/hygenic problems we favour a hip replacement in cases with osteoarthritis or high risk of osteoporotic fracture. A replacement of the joint should be preferred to a Girdlestone operation.

Contribution of hospital characteristics to the volume-outcome relationship: dislocation and infection following total hip replacement surgery.

Mortality and complication rates after total hip replacement (THR) are inversely associated with the volume of THRs performed at hospitals and by individual surgeons. It is not clear, however, why a higher volume of such procedures is associated with better outcomes. We evaluated the contribution of hospital structural characteristics to the volume-outcome relationship in THR by examining the rates and predictors of postoperative complications. We analyzed data pertaining to 5,211 Medicare patients who underwent primary THR in 1995 or 1996 at 167 hospitals in Colorado, Pennsylvania, and Ohio. Data were derived from several sources, including Medicare Part A and Part B claims, the American Board of Medical Specialties, a hospital survey regarding institution-specific characteristics and structural aspects of the care setting, and the American Hospital Association 1995 Annual Survey. Multivariate models were constructed to determine whether hospital structure or surgeon-associated factors may underlie the relationship between volume of THRs and the occurrence of perioperative orthopedic adverse events, defined as deep wound infection or hip dislocation within 90 days of surgery. Of the patients studied, 2.6% experienced an orthopedic adverse event after THR. Sixty-nine percent fewer events occurred in hospitals where >100 THRs in Medicare patients were performed annually, compared with hospitals where <or=25 THRs were performed. In univariate analyses, several hospital-level factors were associated with a reduced (approximately 50%) risk of adverse events, including private (versus public) ownership, membership in the Council of Teaching Hospitals, presence of any residency training program, availability of a dedicated orthopedic nursing unit, and existence of operating rooms with laminar flow exhaust systems. However, the only hospital-level factor associated with adverse events in multivariate models was the use of laminar flow exhaust systems. When surgeon volume was added to the models, it was the strongest predictor of adverse events, with hospital volume and hospital-level factors having no appreciable association with adverse events. Hospital-level factors were not independent predictors of the association between hospital volume and orthopedic adverse events. The volume of THRs performed by individual surgeons is the most important determinant of orthopedic complications and should be considered in efforts to improve THR outcomes.

Does waiting for total hip replacement matter? Prospective cohort study.

To assess the impact on the outcome of total hip replacement of the length of timing spent waiting for surgery. One hundred and forty-three orthopaedic and general hospitals provided information about aspects of surgical practice for each total hip replacement conducted between September 1996 and October 1997 for publicly and privately funded operations in five English health regions. These data were linked to patient information about hip-related pain and disability status (measured using the Oxford Hip Score) before operation and at 3 and 12 months after. Data were analysed using multiple regression analysis. Questionnaires were completed by surgeons for 10,410 (78%) patients treated during the recruitment period and by 7151 (54%) patients. Twelve months after total hip replacement, the majority of patients experienced substantial improvements in hip-related pain and disability (as measured by the Oxford Hip Score). Those patients who started with a worse Oxford Hip Score before the operation tended to remain worse after the operation. Worse pre-operative score was associated with an increased length of either outpatient or inpatient wait, and this trend remained after the operation. The relationship between waiting time and outcome remained after adjustment for possible confounding variables. A consistently worse score was observed in public compared with private patients at all three time-points. In addition, in both sectors, those patients who were socially disadvantaged had a worse score than more socially advantaged patients both before and after the operation. Waiting for surgery is associated with worse outcomes 12 months later. Longer-term outcome needs to be considered to see if this association persists.

Association between hospital and surgeon procedure volume and outcomes of total hip replacement in the United States medicare population.

The mortality and complication rates of many surgical procedures are inversely related to hospital procedure volume. The objective of this study was to determine whether the volumes of primary and revision total hip replacements performed at hospitals and by surgeons are associated with rates of mortality and complications. We analyzed claims data of Medicare recipients who underwent elective primary total hip replacement (58,521 procedures) or revision total hip replacement (12,956 procedures) between July 1995 and June 1996. We assessed the relationship between surgeon and hospital procedure volume and mortality, dislocation, deep infection, and pulmonary embolus in the first ninety days postoperatively. Analyses were adjusted for age, gender, arthritis diagnosis, comorbid conditions, and income. Analyses of hospital volume were adjusted for surgeon volume, and analyses of surgeon volume were adjusted for hospital volume. Twelve percent of all primary total hip replacements and 49% of all revisions were performed in centers in which ten or fewer of these procedures were carried out in the Medicare population annually. In addition, 52% of the primary total hip replacements and 77% of the revisions were performed by surgeons who carried out ten or fewer of these procedures annually. Patients treated with primary total hip replacement in hospitals in which more than 100 of the procedures were performed per year had a lower risk of death than those treated with primary replacement in hospitals in which ten or fewer procedures were performed per year (mortality rate, 0.7% compared with 1.3%; adjusted odds ratio, 0.58; 95% confidence interval, 0.38, 0.89). Patients treated with primary total hip replacement by surgeons who performed more than fifty of those procedures in Medicare beneficiaries per year had a lower risk of dislocation than those who were treated by surgeons who performed five or fewer of the procedures per year (dislocation rate, 1.5% compared with 4.2%; adjusted odds ratio, 0.49; 95% confidence interval, 0.34, 0.69). Patients who had revision total hip replacement done by surgeons who performed more than ten such procedures per year had a lower rate of mortality than patients who were treated by surgeons who performed three or fewer of the procedures per year (mortality rate, 1.5% compared with 3.1%; adjusted odds ratio, 0.65; 95% confidence interval, 0.44, 0.96). Patients treated at hospitals and by surgeons with higher annual caseloads of primary and revision total hip replacement had lower rates of mortality and of selected complications. These analyses of Medicare claims are limited by a lack of key clinical information such as operative details and preoperative functional status.

The Association Between Hospital and Surgeon Procedure Volume and Outcomes of Total Hip Replacement in the United States Medicare Population: Health Policy Implications

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