Hip Resurfacing Arthroplasty In Patients Research Articles

A Pilot Experiment to Measure the Initial Mechanical Stability of the Femoral Head Implant in a Cadaveric Model of Osteonecrosis of Femoral Head Involving up to 50% of the Remaining Femoral Head

Background and Objectives: Currently, only patients with osteonecrosis of the femoral head (ONFH), who had bone defects involving 30-33.3% of the remaining femoral head, are indicated in hip resurfacing arthroplasty (HRA). In an experimental cadaver model of ONFH involving up to 50% of the remaining femoral head, the initial stability of the femoral head implant (FHI) at the interface between the implant and the remaining femoral head was measured. Materials and Methods: The ten specimens and the remaining ten served as the experimental group and the control group, respectively. We examined the degree of the displacement of the FHI, the bonding strength between the FHI and the retained bone and that at the interface between the FHI and bone cement. Results: Changes in the degree of displacement at the final phase from the initial phase were calculated as 0.089 ± 0.036 mm in the experimental group and 0.083 ± 0.056 mm in the control group. However, this difference reached no statistical significance (p = 0.7789). Overall, there was an increase in the degree of displacement due to the loading stress, with increased loading cycles in both groups. In cycles of up to 6000 times, there was a steep increase. After cycles of 8000 times, however, there was a gradual increase. Moreover, in cycles of up to 8000 times, there was an increase in the difference in the degree of displacement due to the loading stress between the two groups. After cycles of 8000 times, however, such difference remained almost unchanged. Conclusions: In conclusion, orthopedic surgeons could consider performing the HRA in patients with ONFH where the bone defects involved up to 50% of the remaining femoral head, without involving the femoral head-neck junction in the anterior and superior area of the femoral head. However, more evidence-based studies are warranted to justify our results.

Hip resurfacing arthroplasty in young patients: international high-volume centres' report on the outcome of 11,382 metal-on-metal hip resurfacing arthroplasties in patients ⩽50 years at surgery.

Total hip arthroplasty (THA) in patients younger than 50 years poses significant challenges including postoperative limitations of activity and higher failure rates. Sub-par outcomes of hip resurfacing arthroplasty (HRA) in registries remain controversial due to multiple confounders. Favourable HRA results in some studies are often regarded as irreproducible. The aim of this study is to analyse HRA outcomes in a large international cohort. We compiled a database of 11,382 HRA patients ⩽50 years from an international group of 27 experienced HRA centres from 13 countries. 18 different metal-on-metal (MoM) HRA designs were included with a mean follow-up of 7.6 years. Outcomes were implant survivorship, revision rates, causes for revision, clinical scores and metal ion levels. Outcomes were compared between genders, sizes, implant types and pre-operative diagnoses. Overall cumulative Kaplan-Meier survivorship was 88.9% at 22 years (95% CI: 88.3-89.5%). 2 HRA designs (DePuy Articular Surface Replacement (ASR), and Corin Cormet Hip Resurfacing System (CORMET)) led to inferior results while all others yielded similar survivorships. Excluding ASR and CORMET, implant survivorship in 11,063 cases was 95% at 10 years and 90% at 22 years. In men, implant survivorship was excellent: 99% at 10 years and 92.5% at 21 years. In females, implant survivorship was 90% at 10 years and 81.3% at 22 years. The overall revision rate was 3.6% with most common reasons for revision being implant loosening and adverse local tissue reactions. The best survivorship was found in patients with osteoarthritis (95% CI, 92.1-93.3% at 22 years), the poorest was among dysplastic hips (78.3%; 95% CI, 76.5-80.1% at 20 years, p < 0.001). Comparable revision rates demonstrated here may mitigate some concerns for safety and longevity of MoM HRA implants. Higher demands for activity and functionality in younger patients make HRA a potential alternative to THA.

Outcome of hip resurfacing arthroplasty in patients with coxarthrosis secondary to Crowe′s types I and II developmental hip dysplasia

BackgroundArthritis secondary to developmental hip dysplasia is a surgical challenge because of the anatomic abnormalities, which increase the complexity of any hip arthroplasty. Hip resurfacing has many theoretical advantages compared with conventional hip arthroplasty, especially for young and active patients. These advantages include minimal bone resection, normal femoral loading, avoidance of stress shielding, maximum proprioceptive feedback, reduced risk of dislocation, easy revision, and reconstruction of normal anatomy.Patients and methodsTwenty-six consecutive patients (33 hips) with osteoarthritis secondary to developmental dysplasia of the hip of Crowe types I and II underwent metal-on-metal hip resurfacing through a modified lateral approach of Hardinge, taking care to protect the medial femoral circumflex artery and its retinacular branches over the femoral neck. The average age of the patients at the time of surgery was 62.8 years (range 30-73 years). Five (19%) patients were men and 21 (81%) were women. The mean follow-up was 4.8 years, range 1.8-10.3 years.ResultsFour patients developed heterotrophic ossification, which required excision because of persistent pain in one patient. Three patients had painful trochanteric bursitis; all responded well to local steroid injections. The Harris hip score improved from a mean of 52.2-97.4. There were no major complications, for example, dislocation, fractured neck of femur, loosening, infection, or symptomatic deep venous thrombosis.ConclusionDespite safety warnings, hip resurfacing remains an effective option in certain subgroups of hip dysplasia when it is performed with special precautions.

Hip Resurfacing Arthroplasty in Patients with Varus Deformity of the Femoral Neck-Shaft Angle

Hip resurfacing arthroplasty (HRA) in patients with a varus deformity of the femoral neck-shaft angle (NSA) is associated with poorer outcomes. Our experience has not reflected this. We examined the Oxford Hip Scores (OHS), Harris Hip Scores (HHS) and outcomes of patients with varus hips against a normal cohort to ascertain any significant difference. We identified 179 patients. Measurement of the femoral neck-shaft angle was undertaken from antero-posterior radiographs pre-operatively. The mean NSA was 128.5 degrees (SD 6.3). Patients with a NSA of less than 122.2 were deemed varus and those above 134.8 valgus. These parameters were consistent with published anatomical studies. The 'varus' cohort consisted of 23 patients, mean NSA 118.7 (range 113.6-121.5), mean follow-up 49 months (range 13-74). Mean OHS and HHS were 16 and 93.5 respectively. Complications included 2 cases of trochanteric non-union, but there were no femoral neck fractures, early failures or revisions. The 'normal' cohort consisted of 125 patients, mean NSA 128 degrees, mean follow-up 41 months (range 6-76). The OHS and HSS were 18.8 and 88.9 respectively. Complications included 5 trochanteric non-unions and 1 revision due to an acetabular fracture following a fall. Statistical analysis demonstrated no statistical difference between the cohorts' OHS (p=0.583) or HHS (p=0.139). Our experience in patients with a varus femoral neck has been positive. We have not yet experienced any femoral neck fractures, which we believe is in part due to the use of an uncemented femoral component and preservation of blood supply.

Hip Resurfacing Arthroplasty in Patients with Rheumatoid Arthritis

Objective. This study analyzed the midterm results of hip resurfacing arthroplasty in patients with rheumatoid arthritis. Methods. Between October of 2003 and September of 2008, 13 consecutive hips that were treated with hip resurfacing arthroplasty due to rheumatoid arthritis were analyzed. The average follow up period was 48.6 months and the mean age at the time of operation was 35.9 years old. The mean BMI at the operation was 23.2 kg/m 2 . The implanted prostheses were the Conserve Plus system in five hips, the Birmingham hip resurfacing system in four hips and the Durom system in four hips. The results were clinically evaluated with the Harris hip score, the UCLA activity score, hip or thigh pain, the limb length discrepancy and the range of motion. As radiological evaluation, we observed the patterns of bone remodeling and complications such as femoral neck fracture, loosening and osteolysis. Results. The average Harris hip score improved from 62.2 to 98.9 at the final visit. The range of motion improved to 0 o in flexion contracture, 118.1 o in further flexion, 22.7 o

Outcome of Hip Resurfacing Arthroplasty in Patients with Developmental Hip Dysplasia

Patients with osteoarthritis secondary to developmental dysplasia of the hip (DDH) typically are young and active, which might affect functional ratings or failure rates after resurfacing arthroplasty. We therefore evaluated 24 patients (32 hips; mean age, 44.2 years) after hip resurfacing performed for osteoarthritis secondary to DDH. We used the Harris hip score (HHS), the University of California, Los Angeles (UCLA) activity scale, and a sports and activity questionnaire. A radiographic analysis also was performed. We followed patients a minimum of 28 months (mean, 43 months; range 28-60 months). The HHS improved from a mean of 54.7 to 97.3 and UCLA activity levels increased from a mean of 5.3 to 8.6. All patients returned to sports activity at a mean of 11 weeks after surface replacement. There were no major differences in preoperative and postoperative participation in the most common sports and activities. Two of the 32 replacements (6%) failed. We detected femoral radiolucencies in 10 of the remaining 30 hips. Despite satisfactory outcomes in clinical scores, return to sports, and hip biomechanics, the failure rate of 6% was disappointing. Additional followup is important to assess if failure rates increase in these young, active patients. Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Influence of bone density on total hip resurfacing arthroplasty in patients with osteonecrosis of the femoral head – A radiological analysis

Osteonecrosis of the femoral head is a more progressive disease for which many patients will eventually require total hip arthroplasty. With the advent of improved metal-on-metal prostheses, total hip resurfacing arthroplasty has emerged as a viable treatment option. However, it remains controversial whether this procedure should be used in patients with osteonecrosis when the femoral resurfacing component is implanted onto non-vital bone. In this study the bone mineral density (BMD) of osteonecrotic femoral heads were compared with the BMD of osteoarthrotic femoral heads. The purpose of this study was to analyse the differences between these two groups to gather information that may be useful in predicting the outcome of total hip resurfacing arthroplasty in cases of severe osteonecrosis of the femoral head. The femoral heads were classified according to the ARCO classification using MRI. For DEXA analysis the femoral heads were subdivided into three regions: the cranial femoral head (R1), the caudal femoral head (R2), and the proximal femoral neck (R3). In R3, BMD in osteonecrotic femoral heads was significantly lower than in those with osteoarthrosis and in R2 it was significantly higher. It can be assumed that a higher BMD in the caudal femoral head (R2) is caused by a "reactive interface" that occurred in this region especially in ARCO IV femoral heads. This fact, the lower BMD in the proximal femoral neck (R3) and the individual expansion of the osteonecrotic region should be considered when planning resurfacing arthroplasty for femoral head necrosis.

Use of Metal-on-Metal Total Hip Resurfacing for the Treatment of Osteonecrosis of the Femoral Head

Recently, with the advent of improved metal-on-metal prostheses, total hip resurfacing has emerged as a viable arthroplasty option. However, it remains controversial whether this procedure should be used in patients with osteonecrosis when the femoral resurfacing component is cemented onto dead bone. The purpose of this study was to analyze the clinical and radiographic outcomes of metal-on-metal total hip resurfacing arthroplasty in patients with osteonecrosis of the femoral head. In addition, this group was compared with a matched group of patients who were diagnosed as having osteoarthritis. Forty-two osteonecrotic hips that were treated with a metal-on-metal total hip resurfacing arthroplasty were studied. They were matched by gender, age, prosthesis, surgeon, and surgical approach to forty-two osteoarthritic hips that were treated with the same metal-on-metal prosthesis. In the osteonecrosis group, there were twenty-five men and eleven women, and in the osteoarthritis group, there were twenty-eight men and thirteen women. The mean age at the time of surgery was forty-two years. Patients were followed both clinically and radiographically for a mean of forty-one months. The clinical outcomes were similar for both groups, with a good or excellent outcome in thirty-nine hips (93%) with osteonecrosis and a good or excellent outcome in forty-one hips (98%) with osteoarthritis. In each of the two groups, there were two failures that required conversion to a standard total hip arthroplasty. Survivorship curves were similar for the two patient groups. The short-term results for metal-on-metal total hip resurfacing for this challenging patient population with osteonecrosis were excellent and comparable with those seen in patients with osteoarthritis. We await long-term results to see if these early results are maintained. Prognostic Level II. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.

Metal-on-Metal Hip Resurfacing in Osteonecrosis of the Femoral Head

The treatment of end-stage osteonecrosis of the femoral head remains a challenge to the orthopaedic surgeon. Historically, total hip arthroplasty for this condition has been associated with poor rates of survival and function when compared with total hip arthroplasty for the treatment of osteoarthritis. The purpose of this study was to determine the medium-term clinical and radiographic results of metal-on-metal hip resurfacing arthroplasty in patients with end-stage osteonecrosis of the femoral head. From June 1994 to March 2004, a consecutive single-surgeon series of seventy-three hip resurfacing procedures were performed in sixty patients for the treatment of end-stage osteonecrosis of the femoral head. The cohort included forty-two men (ten of whom had a bilateral resurfacing) and eighteen women (three of whom had a bilateral resurfacing). The mean age was forty-three years (range, seventeen to sixty-nine years). A clinical and radiographic review was performed. There were four revision operations and one planned revision of the seventy-three hips during the follow-up period. Two of these revisions were necessitated by aseptic failure of the femoral component. This represents an overall survival rate of 93.2% at a mean of 6.1 years of follow-up (range, two to twelve years). On the basis of this study, metal-on-metal resurfacing of the hip for osteonecrosis can be considered a safe and effective form of surgery for this group of patients. Longer-term follow-up is required to confirm the expected continued success of this form of arthroplasty in this difficult-to-treat population. Therapeutic Level IV. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.

USE OF METAL-ON-METAL TOTAL HIP RESURFACING FOR THE TREATMENT OF OSTEONECROSIS OF THE FEMORAL HEAD

Background: Recently, with the advent of improved metal-on-metal prostheses, total hip resurfacing has emerged as a viable arthroplasty option. However, it remains controversial whether this procedure should be used in patients with osteonecrosis when the femoral resurfacing component is cemented onto dead bone. The purpose of this study was to analyze the clinical and radiographic outcomes of metal-on-metal total hip resurfacing arthroplasty in patients with osteonecrosis of the femoral head. In addition, this group was compared with a matched group of patients who were diagnosed as having osteoarthritis. Methods: Forty-two osteonecrotic hips that were treated with a metal-on-metal total hip resurfacing arthroplasty were studied. They were matched by gender, age, prosthesis, surgeon, and surgical approach to forty-two osteoarthritic hips that were treated with the same metal-on-metal prosthesis. In the osteonecrosis group, there were twenty-five men and eleven women, and in the osteoarthritis group, there were twenty-eight men and thirteen women. The mean age at the time of surgery was forty-two years. Patients were followed both clinically and radiographically for a mean of forty-one months. Results: The clinical outcomes were similar for both groups, with a good or excellent outcome in thirty-nine hips (93%) with osteonecrosis and a good or excellent outcome in forty-one hips (98%) with osteoarthritis. In each of the two groups, there were two failures that required conversion to a standard total hip arthroplasty. Survivorship curves were similar for the two patient groups. Conclusions: The short-term results for metal-on-metal total hip resurfacing for this challenging patient population with osteonecrosis were excellent and comparable with those seen in patients with osteoarthritis. We await long-term results to see if these early results are maintained. Level of Evidence: Prognostic Level II. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.

Metal-on-metal surface hip arthroplasty in patients with abnormal Coxanatomy: preliminary results.

The purpose of this study was to evaluate early to intermediate results of metal-on-metal (MoM) hip resurfacing arthroplasty in patients with abnormal hip anatomy. We evaluated nine MoM hip resurfacing arthroplasty in eight patients with abnormal coxanatomy performed at a district general hospital in the UK between March 1999 and November 2002. One patient had undergone bilateral sequential hip resurfacing procedure. These patients were defined to have abnormal coxanatomy by virtue of previous dysplastic disease of hip in three cases, previous Legg-Calve-Perthes disease, multiple epiphyseal dysplasia, T cell acute lymphoblastic leukaemia, trauma and sepsis in one case each. The mean follow-up was 40.8months. The mean age at primary operation was 35years (range: minimum 21years; maximum 44years). There were six male and two female patients. There were six right-sided and three left-sided procedures. All patients had satisfactory outcomes. There were no deep infections, dislocations, or femoral neck fractures. Although this is a short series, MoM resurfaced hips with appropriate case selection can yield satisfactory short-term to intermediate-term results in the young and active patients with abnormal hip anatomy.