Catastrophic wear in uncemented acetabular cups after Total Hip Arthroplasty. A case series.

INTRODUCTION: Catastrophic wear is a rare outcome following Total Hip Arthroplasty (THA), documented to happen in less than 0.5% of THA. We present 5 cases of revision THA performed successfully on 5 patients presenting Catastrophic wear, following Total Hip Arthroplasty (THA). Specifically, Catastrophic wear cases were selected, emphasizing differential diagnosis, and a revision THA was performed in all of them and resulted in a good long-term outcome. The purpose of this case series is to contribute to the literature in evaluating both the causes of implant failure as well as the outcomes after their revisions. METHODS: We evaluated 5 patients that presented Catastrophic rupture of acetabular implants in a 3-week period in our prosthesis center. RESULTS: The 5 patients were females, the mean age was 56 years (44-65), the mean post-surgery time was 20 years (17-23), 4/5 of the coupling wear was ceramic-polyethylene and only one case was metal-polyethylene; 4/5 had bilateral total hip replacement. In the 5 cases a revision THA was performed, all with a successful outcome. CONCLUSION: Catastrophic failure is an unusual entity; however, when a patient with a prosthesis presents with sudden pain, an immediate image study is indicated, with careful attention to the differential diagnosis, so as to accurately advice receiving a revision THA. The main causes of implant failure are implant duration, volumetric wear and subsequent rupture. Patients with Catastrophic wear and implant rupture, treated with a revision THA, usually have a good long-term outcome.

Fracture of the astragalus in pediatric patients, an unusual entity.

INTRODUCTION AND IMPORTANCE: The fracture of the astragalus is an unusual bone fracture (Ladero and Concejero, 2004) and is even more unusual in pediatric patients. The astragalus is a bone surrounded by cartilage and other structures making it difficult to appreciate on an X-ray which can lead to misdiagnosis (Ladero and Concejero, 2004; Inal and Inal, 2014) and could lead to not applying the right treatment and risk avascular necrosis or other sequelae. CASE PRESENTATION: 3-year-old male with foot pain and edema+++, unable to walk or stand up since a fall 2 days before, had a doubtful diagnosis after an x-ray showed no apparent bone injury. A CT scan confirmed astragulus fracture; it was then treated adequately, thus avoiding complications that could have occurred had the fracture not been diagnosed and treated correctly. CLINICAL FINDINGS AND INTERVENTIONS AND OUTCOME: The limb was immobilized with a suropodalic cast for 5 weeks. No surgery was performed because of the patient's age and because the fracture was not displaced (Hawkins type 1) (Jasqui-Remba and Rodriguez-Corlay, 2016; Urrutia et al., 1999). RELEVANCE AND IMPACT: There is a risk of misdiagnosis in these cases since the astragulus fracture might not show up in an X-ray, as in the case presented. A CT scan can detect the fracture and thus help consolidate the bone correctly. The correct differential diagnosis also reduces the risk of avascular necrosis, which increases due to poor blood supply to the astragalus.

Solitary enchondroma in a metatarsal bone, an incidental discovery.

INTRODUCTION: Enchondromas are rare benign bone tumours and their discovery is usually incidental, since in most cases it presents with no symptoms. PRESENTATION OF CASE: A 30 year old male who comes to the office after suffering a forced inversion of the left foot, he has edema of the left lateral malleolus, pain and is unable to walk; no deformities or other alterations are observed and palpable pulses of adequate intensity and frequency are recorded. The radiography shows soft tissue edema and no bone lesions. A tumour is found in the first metatarsal, which was afterwards corroborated by an MRI; once the diagnosis was confirmed, curettage of the lesion was performed with good outcome. DISCUSSION/CONCLUSION: Multiple enchondromas and solitary enchondromas, left untreated, can transform into malignant bone tumours like chondrosarcomas, so early detection and treatment, in most cases with lesion curettage and bone grafting, become fundamental for a good prognosis.

Bilateral femoral neck stress fractures in a high-performance young female runner.

A 16-year-old female patient showed up at the orthopaedics unit complaining of intolerable pain on her left hip. While being questioned and her clinical history written down, she shared that as part of her daily exercise routine, she ran 10 miles (16 km) daily at a speed of 9.5-10.5 mph (15-17 km/hour). MRI was consequently ordered, confirming the presence of a stress fracture. Therefore, immediate suspension of physical activity was indicated, followed by the prescription of crutches as well as restricted weight bearing. Gradually, she recovered complete functionality and approximately a month after she had entirely healed. While on a skiing trip, again she abruptly developed an acute pain on her right hip. Another MRI was ordered; its result confirmed a new stress fracture. Her previous treatment has proved so successful, a conservative approach was once again prescribed for her, showing optimum results 6 months later.

Muscular tendinous junction rupture of the posterior tibial tendon after closed bimalleolar ankle fracture.

In this case report, we present an acute rupture in the muscular tendinous junction of a posterior tibialis muscle in a bimalleolar closed ankle fracture after a high-energy trauma in a 30-year-old patient with no significant medical history. Fracture was confirmed by simple X-rays, and was treated with an open reduction in which both of the fractures were treated with osteosynthesis material and reparation of the syndesmosis. If left untreated, this uncommon finding can result in a bad postsurgical outcome; we believe this injury is more common but under-reported in the literature. The surgeon should be aware and look specifically for this type of lesion during the procedure. Finding and treating this injury requires special postoperative care, non-weight-bearing instructions and balanced physiotherapy.