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.

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.

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.

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.

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.

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.

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.