Medium-term outcomes of conventional versus short uncemented femoral stems for primary total hip arthroplasty in patients younger than 55 years

BACKGROUND

Short stems are designed with a bone preservation philosophy in mind. This study aims to compare the outcomes/complications and survival of a collarless fully hydroxyapatite (HA)-coated conventional tapered stem and a HA-coated partial neck-retaining uncemented short stem in patients ⩽55 years old at medium-term follow-up.

METHODS

We retrospectively studied 247 uncemented THAs operated between 2010 and 2014, comparing 146 patients treated with the fully HA-coated collarless stem (Group A) with 101 patients treated with a partial neck preserving, HA-coated short stem (Group B). 87 and 62 males were in groups A and B, respectively (p = 0.11). The mean age of the series was 46 years (17-55) (p =0.16). The mean follow-up of groups A and B were 9.9 (7-12) years and 9.7 (7-12) years, respectively (p =0.21).

RESULTS

Mean Harris Hip Score improved from 55 to 92 in group A (p <0.001) and from 54 to 95 in group B (p <0.001), without differences between groups. Mean femoral neck length preservation in groups A and B was 13.6 (0-28) mm and 26 (11-38) mm, respectively (p =0.001). 13 (8.9%) and 1 (1%) patients in groups A and B presented postoperative complications, respectively (p =0.008). The conventional stem group had more aseptic loosening (Group A 3.4% vs. Group B 0%, p =0.06) along with more Symptomatic radiolucent lines (Group A 3.4% vs. Group B 0%, p =0.06).

CONCLUSIONS

Both conventional and short stems showed excellent implant survival rates and functional outcomes at a mean follow-up of 9.8 years. However, complications and radiolucent lines were more frequent with a collarless conventional-length stem. Bone preservation of the femoral neck and diaphysis may be preferred in active young patients.

Stenotrophomonas maltophilia Periprosthetic Joint Infection after Hip Revision Arthroplasty

Stenotrophomonas maltophilia, a well-established opportunistic bacterium, primarily impacts healthcare settings. Infection of the musculoskeletal system with this bacterium is rare. We report on the first known case of hip periprosthetic joint infection (PJI) caused by S. maltophilia. The potential for development of a PJI caused by this pathogen should be considered by orthopaedic surgeons, particularly in patients with multiple severe comorbidities.

Short-Term Results of Osteochondral Autologous Transfer and Femoral Neck Osteochondroplasty for the Treatment of Osteochondral Lesions of the Femoral Head and Concomitant Femoroacetabular Impingement Syndrome: A Case Series

This study aimed to analyse the initial results of five patients with symptomatic osteochondral lesions (OCL) and femoroacetabular impingement (FAI) who were treated successfully with osteochondral autologous transfer (OAT) and femoral neck osteochondroplasty (OCP) through surgical dislocation of the hip. Five patients with FAI and OCL of the femoral head who underwent surgery between 2015-2018 were studied retrospectively. All patients had a grade IV OCL, and the median defect size was 2 cm² (interquartile range [IQR], 2-2). At the final follow-up, the modified Harris hip score showed a median value of 94 (IQR, 91-95) (P=0.04). Pain evaluation using the visual analogue scale showed a median value of 1 (IQR, 1-2) (P=0.04). Adequate graft union and healthy formation of the chondral surface were observed by magnetic resonance imaging. Although the procedure is demanding, the combination of OAT and femoral neck OCP appears to be an effective alternative in young patients.

Fracture of a triple-polished tapered cemented femoral stem at the Morse taper after metal-on-metal primary total hip arthroplasty

Total hip arthroplasty, one of the most successful orthopaedic procedures, is influenced by several variables. Corrosion at the modular junction is known as trunnionosis. Despite being reported infrequently, corrosion between the femoral head and the Morse taper can result in severe complications. Fracture of the femoral component in primary metal-on-metal (MoM) total hip arthroplasty at the Morse taper is an extremely rare event and can be associated with several risk factors. We report a case of corrosion at the Morse taper in a hybrid primary MoM total hip arthroplasty, resulting in Morse taper fracture with consequent femoral head entrapment inside the acetabular component. We hypothesise that some risk factors, such as age over 60years, active male patients, body mass index above 30kg/m², large femoral heads, high-offset stems, 9/10 Morse taper and MoM-bearing surfaces, are associated with this mode of failure.

The Diagnosis and Treatment of Acetabular Bone Loss in Revision Hip Arthroplasty: An International Consensus Symposium

Despite growing evidence supporting the evaluation, classification, and treatment of acetabular bone loss in revision hip replacement, advancements have not been systematically incorporated into a single document, and therefore, a comprehensive review of the treatment of severe acetabular bone loss is needed. The Stavros Niarchos Foundation Complex Joint Reconstruction Center at Hospital for Special Surgery held an Acetabular Bone Loss Symposium on June 21, 2019, to answer the following questions: What are the trends, emerging technologies, and areas of future research related to the evaluation and management of acetabular bone loss in revision hip replacement? What constitutes the optimal workup and management strategies for acetabular bone loss? The 36 international experts convened were divided into groups, each assigned to discuss 1 of 4 topics: (1) preoperative planning and postoperative assessment; (2) implant selection, management of osteolysis, and management of massive bone loss; (3) the treatment challenges of pelvic discontinuity, periprosthetic joint infection, instability, and poor bone biology; and (4) the principles of reconstruction and classification of acetabular bone loss. Each group came to consensus, when possible, based on an extensive literature review. This document provides an overview of these 4 areas, the consensus each group arrived at, and directions for future research.

Six-stage revision surgery of a triple periprosthetic joint infection due to a delayed diagnosis of a bilateral psoas abscess: a case report

CASE

We present a case of a 70-year-old woman with simultaneous periprosthetic joint infection (PJI) of both hips and left knee due to a bilateral psoas abscess. The patient underwent debridement and implants removal with the consequent reimplantation in a sequential six-stage revision surgery. At four years of follow-up and in spite of the patient's comorbidities and current PJI presentation, she maintains full activities of daily living without restrictions.

CONCLUSION

Accurate and early diagnosis of a psoas abscess is crucial. This case report provides experience of a complex scenario, the decision-making involved and the outcomes of an underdiagnosed complication.

Gait instability may indicate liner failure in patients with total hip arthroplasty. A report of three cases

Total hip arthroplasty is one of the most common and successful orthopaedic procedures performed worldwide. Uncemented modular acetabular components and highly cross-linked polyethylene liners are the implants of choice for most arthroplasty surgeons. However, despite their well-known benefits, highly cross-linked polyethylene liners are not without complications, such as rim fracture, rupture and dissociation. We report three patients with gait instability and radiographic subluxation due to highly cross-linked polyethylene liner failures evidenced during stage one revision surgery. The three patients were symptoms free, with no new instability episodes, and the radiographs showed no evidence of implant loosening at the most recent follow-up. Although it is a rare complication, these three cases highlight the importance of suspecting and evaluating highly cross-linked polyethylene liner failures in patients referred for gait instability with no history of previous trauma.

Conversion total hip arthroplasty with a proximally modular, distal fixation reconstruction prosthesis following cephalomedullar nail failure

BACKGROUND

The goals of intertrochanteric hip fracture (IHF) treatment are stable fixation, early mobilisation and function restoration. If the attempt to reduce, stabilise and fracture healing utilising a femoral cephalomedullar nail (CMN) fails, options for subsequent attempts are limited.

PURPOSE

Evaluate the clinical and radiographic outcomes of conversion total hip arthroplasty (THA) using a modular stem following a CMN failure.

MATERIALS AND METHODS

We retrospectively reviewed a consecutive series of patients with an IHF between 2012 and 2014 to identify CMN patients that went on to the subsequent failure and conversion to THA utilising a modular femoral stem (MFS). In all cases, MP Reconstruction Prosthesis (Waldemar Link, Hamburg, Germany) was implanted. Primary clinical outcomes were assessed using Harris Hip Score (HSS) before conversion procedure, 3 months, 6 months and recent office visit post-conversion THA thereafter. The secondary outcome was to analyse intra and postoperative complications. Serial radiographs at each follow-up interval were assessed for clinical success or to confirm adverse events.

RESULTS

28 patients were included in the study; 17 were females. The average age was 72.7 years (SD ± 10.5); the average time from the index procedure to conversion THA was 12.6 months (SD ± 3.5). At baseline, average HHS was 42.1 (SD ± 3.6), improved to 80.7 (SD ± 5.1) at 3 months, 86.0 (SD ± 3.9) at 6-months which levelled off to 86.1 (SD ± 4.0) at final follow-up. There were 4 (14%) post-conversion complications: 2 dislocations, 1 superficial wound infection, 1 patient with symptomatic abductor deficiency. All 4 cases were conservatively treated successfully, the implants were retained, and the patients progressed without further issue.

CONCLUSIONS

MFSs allow to successfully treat failed CMN and adverse variations in femoral anatomy with a device that will permit simultaneous correction of leg length, offset and version to relieve pain, restore function and create a durable prosthetic to host composite.

Simultaneous Bilateral Femoral Neck Fracture Due to a Tonic-Clonic Seizure and High-Dose Steroid Therapy

Simultaneous bilateral femoral neck fractures (FNFs) are extremely rare and usually associated with an underlying condition affecting the bone quality and mineralization. Convulsions have also been described as a possible cause, mostly as a consequence of epilepsy, hyponatremia, and hypocalcemia. We present a 52-year-old female patient, with bilateral displaced FNFs due to a tonic-clonic seizure and high-dose steroid therapy related to a frontal lobe anaplastic oligodendroglioma brain tumor resection. Two days after admission, bilateral one-stage uncemented total hip arthroplasty (THA) under general anesthesia and through a posterolateral approach was performed using a metal-on-polyethylene bearing surface. Several risk factors can be identified in this unique case, such as the high-dose steroid therapy, the low-demand activity of the patient due to her functional sequelae, and finally, the convulsive episode. Surgeons should be aware of this uncommon injury to ensure early diagnosis and treatment in all patients with a previous history of seizures, chronic steroid use, severe hip pain, and inability to walk. For bone metabolic diseases, preventive measures should be indicated to avoid these complications. Bilateral one-stage uncemented THA represents an effective procedure with a low complication rate allowing early rehabilitation.

Outcomes using wedge stem with full hydroxiapatite coverage with a minimum of 5 years' follow-up

INTRODUCTION

Total Hip Arthroplsty (THA) using uncemented stems is a popular practice in the last decades. The implant survivorship is crtitical and a less than 10% revision at 10 years is been propesed for commercialization and use.

OBJECTIVE

To analyse the clinicoradiological results of an uncemented hydroxiapatite covered wedge stem with a 5 years minimum follow up.

MATERIAL AND METHODS

Prospective study, patients aged from 21-75years were included. All patients received an Element stem (Exactech) and uncemented cup with crosslink poly and 32 mm metal head, and posterior approach with piriformis retention was used. Scheduled clinical and radiographic evaluation at 3 weeks, 3-6 month, year and subsequent years using Harris Hip Score and Merle d'Aubigné Postel. Intraoperative and during follow up complications were recorded.

RESULTS

One hundred and fourteen total hip replacements in 104 patients: 54 females and 50 males (52%/48%). Follow-up of 5.7 years (range, 5-6.2years). Average age 56.8years (range, 42-75years). Clinical evaluation the Merle d'Aubigné score improved 6.8 points and from the initianl Harris Hip Score 47.3 to 93.1 points at last follow up. Radiographic evaluation shows osteointegration in all stems. And in 6 cases (5.3% at 3 months subsidence was detected, average 1.4 mm (range 0-2.6 mm) with no clinical manifestation, 3 cases of subsidence were associated to intraoperative fractures (1 greater trochanter and 2 in the calcar area, all resolved with wire cerclaje). Subjective evaluation: 86 cases (82.6%) excellent, 9 patients (8.6%) good, 6 cases (5.9%) satisfactory and 3 cases (2.9%) poor. All poor results linked to the intraoperative complications. No patient lost during follow up period. No femoral pain dislocation or aseptic or loosening detected. All implants were in situ at last follow up.

CONCLUSIONS

The radiological results confirm the benefits of this type of stem with good osteointegration. The clinical and subjective results are promising. With good surgical technical and without complications the risk of aseptic loosening should be absent or minimal.

Joint preservation after hip arthroscopy in patients with FAI. Prospective analysis with a minimum follow-up of seven years

BACKGROUND

The purpose of this study is to evaluate the clinical outcomes, radiological degenerative progression and the joint preservation rate in a series of patients with Femoroacetabular Impingement (FAI) treated with hip arthroscopy at a minimum follow-up of 7 years. The predictive factors for total hip arthroplasty (THA) requirement were analyzed.

MATERIALS AND METHODS

Between February 2008 and February 2009, 42 consecutive patients treated with hip arthroscopy due to FAI syndrome were included. There were 15 women and 27 men with an average age of 38 years (range 23 to 56 years). The surgery involved joint damage stabilization (labral tears and/or chondrolabral injuries) and correction of associated bony deformities (cam and/or pincer lesions). A prospective clinical follow-up was made with no patient lost. We specifically addressed the need for THA. Predictive factors for THA were also analyzed.

RESULTS

At final follow up, joint preservation rate was 83.33% (CI 95% 68,64%-93,03%). Probability of evolving to a THA in patients with radiographic preoperative Tonnis grades 0 and I was of 0% (CI 95%: 0-12.77). Probability of evolving to a THA in patients with preoperative Tonnis grades II and III was 46,67% (CI 95%21.27%-73,41%). A statistically significant difference was present between both groups (p= 0.002). Patients older than 45 years at the time of hip arthroscopy were at significant risk of evolving to a THA (p=0.0012). Excluding those patients who undergone a THA: modified HHS was 88.25 points (80-96) and radiographic analysis addressed a 14,29% (IC95% 4,81%-30,26%) of progressive degenerative changes without affecting clinical results.

CONCLUSIONS

Hip arthroscopy for the treatment of patients with FAI syndrome showed favorable results regarding joint preservation. Patients with preoperative radiographic evidence of advanced-stage osteoarthritis and those older than 45 years at the time of surgery have higher risk of requiring THA.

LEVEL OF EVIDENCE

IV.

Total hip arthroplasty for hip fractures: 5-year follow-up of functional outcomes in the oldest independent old and very old patients

INTRODUCTION

This study aimed to determine the dislocation and reoperation rate, functional outcomes, and the survival rate of the unique subset of very old but lucid and independent patients with hip fractures following a total hip arthroplasty (THA) and geriatric team-coordinated perioperative care.

METHOD

Between 2000 and 2006, previously independent ambulatory patients ≥80 years old presenting with an intracapsular hip fracture were given THAs under the care of an integrated orthopedic surgery-geriatric service. Their fracture-related complications, ambulation, mental status, and survival were followed for 5 to 11 years postinjury.

RESULTS

Five years postinjury, 57 (61.3%) patients of the original study group were living. In all, 3 (3.2%) patients had postoperative hip dislocations (and 2 patients had dislocation twice) and 2 reoperations were needed within the first postoperative month. There were no hip dislocations or reoperations after the first year. Radiographs obtained on 88% of the surviving patients at 5 years postoperatively showed that all remained unchanged from their immediate postoperative images. Nearly half of the patients were still able to ambulate as they did preoperatively and their mixed-model equation was statistically unchanged.

CONCLUSION

This study of patients >80 years old with previously good functional status demonstrates that with appropriate surgical (best prosthesis, good operating technique, and regional anesthesia) and geriatric (pre- and postoperative assessments, close follow-up, medication adjustments, and fall-prevention instruction) care, they have few hip dislocations and reoperations, survive postfracture at least as long as their noninjured contemporaries, and continue to function and ambulate as they did prior to their injury.

Viability of impacted bone allografts under metal mesh at the calcar in revision surgery of the hip

Metal meshes are used in revision surgery of the hip to contain impacted bone grafts in cases with cortical or calcar defects in order to provide rotational stability to the stem. However, the viability of bone allografts under these metal meshes has been uncertain. We describe the histological appearances of biopsies obtained from impacted bone allografts to the calcar contained by a metal mesh in two femoral reconstructions which needed further surgery at 24 and 33 months after the revision procedure. A line of osteoid and viable new bone was observed on the surface of necrotic trabeculae. Active bone marrow between these trabeculae showed necrotic areas in some medullary spaces with reparative fibrous tissue and isolated reactive lymphocytes. This is interpreted as reparative changes after revascularisation of the cancellous allografts. These pathological findings are similar to those reported in allografts contained by cortical host bone and support the hypothesis that incorporation of morcellised bone under metal meshes is not affected by these devices.

Vancomycin-supplemented cancellous bone allografts in hip revision surgery

We explored the role of vancomycin-supplemented cancellous bone allografts in hip revision surgery. We evaluated the incorporation of these allografts in 18 pigs' radiographs, histology, and immunohistochemistry. High-quality radiographs, histologic examination, and immunologic expression of metalloproteinase-13 and transforming growth factor-beta 2 indicated vancomycin did not considerably affect bone graft incorporation. Elution, bioactivity, and nephrotoxicity were subsequently tested in 20 patients who underwent hip reconstruction with this method. Local active bactericidal levels of vancomycin reached 1400.5 microg/mL (average 5-point level, 367.19 microg/mL). Vancomycin was present in urine until day 15 without any sign of nephrotoxicity. Clinical analysis was performed in 30 patients whose hips underwent reconstruction with vancomycin-supplemented cancellous bone allograft. At a minimum 2-year followup, infection control was attained in 29 of 30 patients (reinfection rate, 3.3%; 95% confidence interval, 0.08-17%) without evidence of graft resorption. Histologic observations performed in two patients whose hips were reconstructed with this technique were similar to the ones reported in nonsupplemented bone allografts. Our findings encourage the continued use of vancomycin-supplemented bone allografts in reconstructive orthopaedic surgery.

Initial stability of circumferential meshes with impacted bone allografts for massive femoral defects

When the proximal femur is absent due to a failed femoral stem in total hip arthroplasty, impacted bone grafts contained within circumferential meshes could be an alternative reconstructive method. The purpose of this study was to analyse the initial resistance to axial and rotational forces in a fresh frozen bovine model with complete loss of the proximal femur reconstructed with a circumferential metal mesh, impacted bone allografts and a long cemented stem. Four bovine femurs with a complete proximal bone defect were reconstructed with a circumferential mesh, impacted bone grafts and a cemented stem. The results were compared with four intact femurs using the same implant. Under axial load, subsidence was observed at an average of 617 kg in the experimental group, and a cortical fracture occured at 1335 kg in the control group. Under rotational load, experimental femurs failed at an average of 79 kg and the control femurs fractured at 260 kg. This model provided 50% of the resistance to axial load and 30% of the resistance to rotational load compared to an intact femur, which is enough to resist physiological load. This stability encourages the use of circumferential meshes, impacted bone allografts and cemented stems in revision hip surgery with massive bone loss.

Modular femoral head dissociation after dislocation and entrapment in reconstruction ring: a case report

Dissociation of modular components is an infrequent potential complication characteristically unique to modularity. We present a patient in whom dissociation of the modular femoral head occurred at attempted closed reduction after dislocation, with the intraoperative findings including entrapment of the head between the rim of a reconstruction ring and the acetabular bone. In the case a dislocation in a patient that was previously reconstructed with a reinforcement ring and a modular femoral stem occurs, dissociation of the modular head should be considered as an extremely uncommon complication that does not outweigh the advantages given by modularity.

Acetabular reconstruction with impacted bone allografts and cemented acetabular components

We reviewed the clinical and radiological results of 131 patients who underwent acetabular revision for aseptic loosening with impacted bone allograft and a cemented acetabular component. The mean follow-up was 51.7 months (24 to 156).

The mean post-operative Merle D’Aubigné and Postel scores were 5.7 points (4 to 6) for pain, 5.2 (3 to 6) for gait and 4.5 (2 to 6) for mobility. Radiological evaluation revealed migration greater than 5 mm in four acetabular components. Radiological failure matched clinical failure. Asymptomatic radiolucent lines were observed in 31 of 426 areas assessed (7%). Further revision was required in six patients (4.5%), this was due to infection in three and mechanical failure in three. The survival rate for the reconstruction was 95.8% (95% confidence interval 92.3 to 99.1) overall, and 98%, excluding revision due to sepsis.

Our study, from an independent centre, has reproduced the results of the originators of the method.

Persistent infection associated with residual cement after resection arthroplasty of the hip

BACKGROUND

The danger of residual bone cement after resection of infected prosthetic components is controversial.

PATIENTS AND METHODS

We analyzed 10 patients with infected total hip prosthesis who had been treated previously with resection arthroplasty and antibiotics and who had persistent infection with residual cement. In 9 patients, surgical debridement with resection of all the PMMA was performed, and adequate intravenous antibiotics were administered. 1 patient refused surgical treatment, but accepted antibiotics.

RESULTS

At an average of 4 (1-18) years of follow-up, 8 patients had no signs or symptoms of recurrent infection. 1 severely immunodeficient patient died 2 years after the removal of residual cement, for reasons other than his hip. The patient who refused surgical treatment continues to have an active sinus 4 years after first consultation.

INTERPRETATION

Residual cement may be responsible for chronic infection. At resection arthroplasty, as part of the treatment of an infected hip arthroplasty, all devitalized or foreign material must be removed.

Major bleeding after drainage lancet vascular injury in total hip arthroplasty

We report a patient who presented with acute hypovolemic shock due to massive bleeding through the suction drainage lancet holes three days after a total hip arthroplasty. Emergency digital arteriography revealed active bleeding of a perforating muscular branch of the profunda femoris artery located at the level of the lancet holes. Selective embolization with a microcatheter controlled the haemorrhage and avoided further surgical exploration, which could have demonstrated no active bleeding from the hip or pelvis. (Hip International 2004; 14: 44-7).

Insufficiency subchondral fracture of the femoral head: report of 4 cases and review of the literature

Insufficiency subchondral fractures are nontraumatic flattened lesions in the superolateral area of the femoral head, occurring in healthy adults. These lesions were recently described and are an infrequent cause of acute hip pain. We report on 4 patients who were diagnosed with an insufficiency subchondral fracture. All the patients showed radiographic progression of the lesion after 4 months, and 3 patients required a total hip arthroplasty. The etiology and the natural history of these rare lesions remain to be elucidated. These lesions should be differentiated from osteonecrosis and transient osteoporosis, because treatment and prognosis may differ.

A hybrid CT-free navigation system for total hip arthroplasty

OBJECTIVE

To design and evaluate a novel CT-free image-guided surgical navigation system for assisting placement of both acetabular and femoral components in total hip arthroplasty (THA).

MATERIALS AND METHODS

The methodology in this paper is conceptually based on our previous work on CT-free cup placement. For femoral component placement, two patient-specific reference coordinate systems are first defined: One for the pelvis, based on the so-called anterior pelvic plane (APP) concept, and one for the femur, using the center of the femoral head, the posterior condylar tangential line, and the medullary canal axis of the proximal femur. A hybrid method is used for the associated landmark acquisition, which involves percutaneous point-based digitization and bi-planar landmark reconstruction using multiple registered fluoroscopy images. The following clinical parameters are computed in real time: cup inclination and anteversion, antetorsion and varus/valgus of the stem, lateralization, and change in leg length for complete THA. In addition, instrument actions such as reaming, impaction, and rasping are visualized for the surgeon by superimposing virtual instrument representations onto the fluoroscopic images.

RESULTS

A laboratory study of computer-assisted measurement of antetorsion and varus/valgus, change in leg length, and lateralization for femoral stem placement demonstrated the high precision of the proposed navigation system. Compared with CT-based measurement, mean deviations of 1.0 degrees, 0.6 degrees, 0.7 mm, and 1.7 mm were found for antetorsion, varus/valgus, change in leg length, and lateralization, respectively, with standard deviations of 0.5 degrees, 0.5 degrees, 0.6 mm, and 0.7 mm, respectively. A pilot clinical evaluation showed that THA could benefit from this newly developed CT-free hybrid system.

CONCLUSIONS

The proposed CT-free hybrid system promises to increase the accuracy and reliability of THA surgery.

Fat embolism and related effects during reamed and unreamed intramedullary nailing in a pig model

OBJECTIVES

To determine whether reamed or unreamed femoral intramedullary nailing is more adverse to pulmonary function, the authors compared three populations of healthy pigs, analyzing the biochemical and hemodynamic effects related to fat embolism. Likewise, the authors histologically evaluated the presence of bone marrow fat embolism in lungs, heart, kidney, brain, and retina.

DESIGN

Randomized, experimental model.

SETTING

Laboratory.

PARTICIPANTS

Twenty-five male Duroc Jersey adult healthy pigs divided in three groups.

INTERVENTION

Reamed and unreamed intramedullary nailing.

OUTCOME MEASUREMENTS

Biochemical, hemodinamical, and histologic analysis.

METHODS

In the first group of ten pigs, a reamed nail was inserted; in the second group of ten specimens, the authors placed an unreamed nail; and in the third group of five animals (control), only the surgical approach was made without opening the medullary cavity.

RESULTS

The authors did not find statistically significant differences in pulmonary function between the reamed and unreamed group in the hemodynamic, biochemical, and histopathologic parameters evaluated. The histologic analysis of the lung tissue revealed a statistically significant difference between the nailed groups and the control (P < 0.04).

CONCLUSIONS

In this animal model, the results indicate that pulmonary changes and fat embolization during intramedullary nailing occur to the same degree in reamed and in unreamed femurs.

Psoas abscess associated with infected total hip arthroplasty

A 65-year-old man with a left uncemented total hip arthroplasty performed 11 years previously was admitted with a history of progressive low back pain, left hip pain, and sepsis that had begun 6 months earlier. On physical examination, a gross, fluctuant mass was palpated in the left thigh. A computed tomography (CT) scan revealed a 6.5 x 3 cm left retrofascial psoas abscess communicating with the hip joint. The patient underwent irrigation and débridement of the hip with removal of the components. The psoas abscess was drained through the iliopsoas bursa. A residual psoas abscess was drained percutaneously under CT guidance. Cultures isolated Escherichia coli, and the patient responded to 6 months of ciprofloxacin therapy. After 1 year, the patient had no evidence of infection. Pathways of infection spread, diagnosis, and treatment of a patient with this rare association are discussed with a review of the literature.