José Ricardo Negreiros Vicente

Blood loss in the minimally invasive posterior approach to total hip arthroplasty: a comparative study

AIMS Our primary aim was to evaluate whether there is really less bleeding in patients for whom the minimally invasive posterior approach is used in comparison with the direct lateral approach for primary total hip arthroplasty. Our secondary aim was to evaluate the clinical functional results after six months as well as the postoperative radiographic result. METHODS In a comparative non-random prospective study, 76 adult patients underwent elective total hip arthroplasty using one of two approaches. The minimally invasive posterior approach (34 cases; mini-incision group) was compared with the standard direct lateral approach (42 cases; control group). RESULTS Lower total estimated bleeding (means of 1083.5 ml versus 1682.3 ml; p < 0.001) and lower intraoperative bleeding (means of 745.6 ml versus 1282.8 ml; p < 0.001) were found in the mini-incision group. There was, however, no difference in the volume of blood drained after the operation (means of 340 ml and 399 ml; p = 0.77). There was also a difference between the two groups regarding the need for allogenic transfusion (8.8% in the mini-incision group versus 28.6%, p = 0.02). We observed a better clinical result in the mini-incision group (p = 0.002) despite the lack of difference between the two groups in relation to the radiographic result. DISCUSSION Our results draw attention to the possibility that other authors may have underestimated blood losses when using minimally invasive approaches. CONCLUSION The minimally invasive approach gave rise to a positive final impression with regard to lower blood loss.

Acetabular Component Positioning in Total Hip Arthroplasty With and Without a Computer-Assisted System: A Prospective, Randomized and Controlled Study

In a study of the acetabular component in total hip arthroplasty, 20 hips were operated on using imageless navigation and 20 hips were operated on using the conventional method. The correct position of the acetabular component was evaluated with computed tomography, measuring the operative anteversion and the operative inclination and determining the cases inside Lewinneks safe zone. The results were similar in all the analyses: a mean anteversion of 17.4° in the navigated group and 14.5° in the control group (P=.215); a mean inclination of 41.7° and 42.2° (P=.633); a mean deviation from the desired anteversion (15°) of 5.5° and 6.6° (P=.429); a mean deviation from the desired inclination of 3° and 3.2° (P=.783); and location inside the safe zone of 90% and 80% (P=.661). The acetabular component positions tomography analyses were similar whether using the imageless navigation or performing it conventionally.

A comparative study of "plasmacup" and "porous-coated" acetabular components: survival after 10 to 12 years of follow-up

OBJECTIVES: Our primary aim was to compare the long‐term survivorship rates and the rates of successful osseointegration between two different types of uncemented acetabular components. INTRODUCTION: Two types of alloys have primarily been used for the manufacture of the uncemented acetabular components: titanium‐based and cobalt‐based alloys. A titanium‐based alloy appears to be more effective with regard to interface stress transfer to the host bone because of its lower elastic modulus relative to a cobalt‐based alloy. This supposed mechanical advantage of a titanium‐based alloy component motivated this comparative study. METHODS: Two uncemented acetabular components, a porous‐coated acetabulum and a Plasmacup®, were compared with a focus on long‐term prosthesis survivorship and the development of acetabular osseointegration. Five radiographic signs of osseointegration were evaluated at the last follow‐up appointment: (1) absence of radiolucent lines, (2) presence of a superolateral buttress, (3) medial stress‐shielding, (4) radial trabeculae, and (5) an inferomedial buttress. We considered the presence of any three of these radiographic signs, in the absence of acetabular dislocation or symptoms, to be indicative of successful acetabular osseointegration. RESULTS: Among 70 patients implanted with the porous‐coated acetabulum, 80% achieved osseointegration over a mean follow‐up time of 11.9 years versus 75.3% of the 73 patients who received a Plasmacup insert over a mean of 10.7 years. Prosthesis survivorship rates were not different between the two groups. Revision surgery due to mild or severe acetabular osteolysis, polyethylene wear, and aseptic loosening occurred in eight patients (11.4%) with a PCA versus nine (12.3%) with a Plasmacup. CONCLUSIONS: We conclude that, during the first ten years after surgery, there is no significant difference between these two types of uncemented cups with regard to either prosthesis survivorship or successful osseointegration.

Comparison of total hip arthroplasty in osteoarthritis of mechanical and rheumatologic causes

Objective: To compare the use of uncemented implants in total hip arthroplasty in patients with rheumathologic diseases and mechanical osteoarthrosis. Methods: We retrospectively evaluated 196 patients who were operated by the Hip and Arthroplasty Surgery Group of the IOT-HCFMUSP between 2005 and 2009. Patients were divided into two groups: mechanical causes (165 patients) and rheumathologic causes (31 patients). Groups were compared between each other in age, gender and follow-up time. Osseointegration rate and percentage of failure in arthroplasty were evaluated. Results: No statistically significant difference was found in osseointegration rates (in both femoral and acetabular components) in both groups. The rates of revision surgery and implant survival also did not show statistically significant differences. Conclusion: The use of uncemented total hip arthroplasty did not show worse results in rheumathologic patients. Level of Evidence III, Retrospective Case Control Study.

Total hip arthroplasty using a posterior minimally invasive approach - results after six years

Objective To evaluate the medium-term clinical–functional results (minimum follow-up of six years) from total uncemented hip arthroplasty performed by means of a posterior minimally invasive access, in comparison with the traditional right lateral access. Methods In a comparative prospective study, 224 adult patients underwent elective total hip arthroplasty due to a diagnosis of primary or secondary osteoarthrosis. A group of 103 patients with posterior minimally invasive access was compared with a group of 121 patients with the traditional right lateral access. The mean length of follow-up among the patients of this sample was 7.2 years. We evaluated the clinical–functional and radiographic results and occurrences of loosening, along with any complications that occurred, with a minimum follow-up of six years. Results The clinical–functional analyses before the surgical procedure and six years afterwards were similar in the two groups (p = 0.88 and p = 0.55). One patient in the minimally invasive group underwent revision of the acetabular component and two patients in the control group underwent the same procedure (p = 0.46). The Trendelenburg clinical test, which showed weakness of the hip abductor musculature, was present in five patients operated using the traditional lateral route and absent in all those who underwent the minimally invasive procedure (p = 0.06). There was no difference regarding the radiographic parameters obtained, either in acetabular or in femoral positioning (p = 0.32 and p = 0.58). Conclusions The medium-term clinical and radiographic results and the complication rates were similar between the patients who underwent total hip arthroplasty by means of the posterior minimally invasive access and those with the traditional lateral access.

Clinical and epidemiological differences between septic arthritis of the knee and hip caused by oxacillin-sensitive and -resistant s. aureus

OBJECTIVE: To establish the risk factors for joint infection by oxacillin-resistant Staphylococcus aureus (MRSA) using clinical and epidemiological data. METHODS: All septic arthritis cases of the knee and hip diagnosed and treated in our institution from 2006 to 2012 were evaluated retrospectively. Only patients with cultures identified as microbial agents were included in the study. The clinical and epidemiological characteristics of the patients were analyzed, seeking the differences between populations affected by MRSA and oxacillin-sensitive Staphylococcus aureus (MSSA). RESULTS: S. aureus was isolated in thirty-five patients (46.0%) in our total sample, 25 in the knee and 10 in the hip. Of these 35 patients, 22 presented with MSSA and 13 presented with MRSA. Provenance from a health service-related environment, as described by the Centers for Disease Control and Prevention, was the only variable associated with oxacillin-resistant strains of this bacterium (p = 0.001). CONCLUSION: Provenance from a health service-related environment was associated with a higher incidence of MRSA-related septic arthritis, suggesting that this agent should be considered in the initial choice of antibiotic treatment. Previous surgeries of the knee or affected limb and the absence of leukocytes might also be related to infection with this agent.

Restauração do centro de rotação na artroplastia total do quadril minimamente invasiva

PURPOSE: Our aim was to evaluate the challenges in obtaining a successful restoration of the rotation center as well as a good positioning of the acetabular component when using the minimally-invasive posterior approach for uncemented total hip replacement. METHODS: In a comparative non-random prospective study, 64 adult patients underwent elective total hip arthroplasty using the minimally-invasive posterior approach performed by one single surgeon. All patients included in this study had a superior and lateral migration of the rotation center of the hip in comparison to the normal contralateral hip. Patients were excluded from the study if they presented the following: diagnosis of femoral neck fracture, displasic hip types 2, 3 and 4 (Crowes classification), osteoarthritis of the contralateral hip. Of the 64 patients in the study, 39 had a radiographic pre-op acetabular size planning equal or less than 50 mm and 25 patients had a radiographic pre-op acetabular size planning equal or more than 52 mm. We considered a good result the following goals: acetabular bend between 35 and 50 degrees, acetabular size according to the pre-op estimative with full contact in the three zones of DeLee-Charnley , a lower medial and vertical positioning of the rotation center in comparison with the pre-op values and a final limb discrepancy lower than 10 mm. RESULTS: A better restoration of the rotation center, as well as, excellent acetabular positioning was found in patients with smaller acetabular size (equal or less than 50), p=0, 04. We must draw attention to two risks when using the minimally-invasive posterior approach: a vertical acetabular position and a lateral position of the acetabular component increasing the risk of a poor contact in the zone 1 due to an insufficient reaming of the medial acetabular host bone. CONCLUSION: We propose standard surgical approaches in patients with larger anatomical measurements (acetabular planning size more than 50).

Formation of a pseudotumor in total hip arthroplasty using a tribological metal-polyethylene pair

The aim here was to report a case of a young adult patient who evolved with tumor formation in the left thigh, 14 years after revision surgery on hip arthroplasty. Davies in 2005 made the first description of this disease in patients undergoing metal-on-metal hip arthroplasty. Over the last decade, however, pseudotumors around metal-on-polyethylene surfaces have become more prevalent. Our patient presented with increased volume of the left thigh 8 years after hip arthroplasty revision surgery. Two years before the arising of the tumor in the thigh, a nodule in the inguinal region was investigated to rule out a malignant neoplastic process, but the results were inconclusive. The main preoperative complaints were pain, functional limitation and marked reduction in the range of motion of the left hip. Plain radiographs showed loosening of acetabular and femoral, and a large mass between the muscle planes was revealed through magnetic resonance imaging of the left thigh. The surgical procedure consisted of resection of the lesion and removal of the components through lateral approach. In respect of total hip arthroplasty, pseudotumors are benign neoplasms in which the bearing surface consists of metal-on-metal, but they can also occur in different tribological pairs, as presented in this case.

What is the role of core decompression in the early stages of osteonecrosis of the femoral head? Evaluation of the surgical result by functional score and radiological follow-up

Objectives This study is aimed at evaluating whether core decompression of the femoral head in the early stages of femoral head osteonecrosis improves patients’ subjective perception of pain and avoids the progression of the disease to a femoral head collapse and a final indication of total hip arthroplasty. Methods Eighteen patients (30 hips) in the early stages of the disease (Ficat and Arlet 1 and 2A) were evaluated through clinical, radiological, risk factor maintenance, and by the functional Merle D’Aubigné, and Postel score before and after core decompression of the femoral head. Results There was an improvement of symptoms up to the sixth month in 83.3% of the hips evaluated through the Merle D’Aubigné and Postel score. However, 73.3% of the cases evolved with femoral head collapse, and in 50%, total hip arthroplasty was indicated regardless of whether or not the risk factors were maintained. Conclusions Core decompression of the femoral head improves patients’ pain early in the initial stages of the pathology. However, it does not alter the prognosis and the ultimate indication of total hip arthroplasty in the final stages of the disease.

Clinical and radiographic outcomes of hip resurfacing arthroplasty after eight years – a retrospective study

Objective To assess the clinical and radiographic outcomes of hip resurfacing arthroplasty for the treatment of hip osteoarthritis. Methods This study retrospectively assessed 30 patients with hip osteoarthritis who underwent hip resurfacing arthroplasty between 2005 and 2014. Patients of both genders suffering from advanced primary and secondary hip osteoarthritis were included in the study. Data were collected about postoperative complications and the need for revision of the arthroplasty. Antero-posterior pelvis and lateral hip x-rays were performed in order to classify osteolysis according to the Amstutz criteria; the Lequèsne index of severity for osteoarthritis of the hip and the UCLA activity level questionnaires were answered pre- and postoperatively. Results After a mean follow-up of eight years, a statistically significant improvement was observed between the mean of the outcomes of both scores, when compared pre- and postoperatively (p < 0.001). Nevertheless, there was a high incidence of arthroplasty revision (20%), related to the size of the femoral stem and errors in surgical technique. Conclusion Using the appropriate technique, hip resurfacing arthroplasty can present good results in well-selected patients.