Cemented Dual Mobility Cup for Primary Total Hip Arthroplasty in Elder Patients with High-Risk Instability.

Several studies have shown that double mobility (DM) cups reduce postoperative dislocations. Does the cemented dual mobility cup reduce dislocations in a specific cohort of elder patients with a high dislocation risk? Our hypothesis is that this implant is optimal for elder patients because it reduces early dislocation. We have retrospectively reviewed elder patients who underwent total hip arthroplasty (THA) with cemented double mobility cup between March 2009 and January 2018. The inclusion criteria were patients (>75 years) who were operated on for primary THA (osteoarthritis or necrosis) with a cemented dual mobility cup and a high-risk instability (at least two patient-dependent risk factors for instability). The exclusion criteria were revision surgeries or hip fracture. In all the cases, the same surgical approach was performed with a Watson Jones modified approach in supine position. We have collected demographic data, instability risk factors. Patients were classified using the Devane's score, Merle d'Aubigné score and the patient's likelihood of falling with the Morse Fall Scale. Surgical and follow-up complications were collected from their medical history. Sixty-eight arthroplasties (68 patients) were included in the study. The median age was 81.7 years (SD 6.4), and the American Society of Anesthesiologists (ASA) score showed a distribution: II 27.94%, III 63.24% and IV 8.82%. Devane's score was less than five in all of the cases. At least two patient-dependent risk factors for instability (87% had three or more) were present in each case. The median follow-up time was 49.04 months (SD 22.6). Complications observed were two cases of infection and one case of aseptic loosening at 15 months which required revision surgery. We did not observe any prosthetic dislocation. The cemented dual mobility cup is an excellent surgical option on primary total hip arthroplasties for elder patients with high-risk instability.

Mechanical barriers and transforming growth factor beta inhibitor on epidural fibrosis in a rabbit laminectomy model.

BACKGROUND: TGF-ß has been described as a mediator of fibrosis and scarring. Several studies achieved reduction in experimental scarring through the inhibition of TGF-ß. Fibroblasts have been defined as the cell population originating fibrosis, blocking fibroblast invasion may impair epidural fibrosis appearance. For this purpose, biocompatible materials used as mechanical barriers and a TGF-ß inhibitor peptide were evaluated in the reduction of epidural fibrosis. METHODS: A L6 laminectomy was performed in 40 New Zealand white rabbits. Divided into four groups, each rabbit was assigned to receive either collagen sponge scaffold (CS group), gelatin-based gel (GCP group), P144® (iTGFß group), or left untreated (control group). Four weeks after surgery, cell density, collagen content, and new bone formation of the scar area were determined by histomorphometry. Two experienced pathologists scored dura mater adhesion, scar density, and inflammatory infiltrate in a blinded manner. RESULTS: In all groups, laminectomy site was filled with fibrous tissue and the dura mater presented adhesions. Only GCP group presented a significant reduction in collagen content and scar density. CONCLUSION: GCP treatment reduces epidural fibrosis although did not prevent dura mater adhesion completely.

Model of induced leakage of polymethylmethacrilate inside epidural space and prevertebral muscles during vertebroplasty in pigs: clinical, macroscopical, and histological study.

STUDY DESIGN: Experimental study in animals. PURPOSE: Study the clinical behavior of animals after an induced leakage of cement during vertebroplasty in pigs. Study the distribution of polymethylmetacrilate inside the epidural space and prevertebral muscle. Study the histological findings of the spinal cord and muscles, which contact with cement. OVERVIEW OF LITERATURE: Although vertebroplasty has a low rate of complication, leakage of cement is highly frequent. There is paucity, in how cement is distributed inside the spinal canal and what occurs when soft tissue comes into contact with polymethylmetacrilate. METHODS: We performed vertebroplasty on six pigs. We performed a leakage of cement into the epidural space and into prevertebral muscles. Two weeks later we performed an anatomic evaluation regarding the spreading of polymethylmetacrilate and a histological analysis of soft tissues that came into contact with it. RESULTS: No clinical alterations were observed. We observed a laminar distribution of the cement surrounding dura mater, and creating a fusiform cavity inside muscles. Spinal cord was normal in all the animals. In dura mater, we observed: synovialmetaplasia, inflammatory reaction, crystal deposits, and giant-cell-reaction. In muscles, we observed: inflammatory reaction, crystal deposits, giant-cell-reaction, muscular atrophy, fibrosis, and synovial metaplasia. CONCLUSIONS: The spinal cord was normal; it is likely that dura mater and cerebrospinal fluid are responsible to isolate neural structures from cement. Dura mater and muscle showed similar histological changes than other publications. Synovial metaplasia was observed in dura mater and muscles that came into contact with cement. The pulsatile rubbing between the tissue and cement could be responsible of this phenomenon.

Infected vertebroplasty due to uncommon bacteria solved surgically: a rare and threatening life complication of a common procedure: report of a case and a review of the literature.

STUDY DESIGN: Case report. OBJECTIVE: The aim of this work is to describe a case of infected vertebroplasty due to uncommon bacteria solved surgically with 2 years of follow-up and to discuss 6 other cases found in literature. SUMMARY OF BACKGROUND DATA: Vertebroplasty is a well-known and useful technique for the treatment of painful osteoporotic vertebral fractures. Complications, such as cord or root compression or pulmonary embolisms, are infrequent and are mainly related with the frequent escape of cement throughout the vertebral veins. Infection is even more rare, but when it occurs is difficult to manage and can be a life-threatening complication. METHODS: A 63-year-old-man had a spondylitis of L2 after vertebroplasty. The patient was initially managed with antibiotics without clinical improvement. Surgical treatment by anterior debridement and anterior and posterior stabilization was done. The bacteria isolated from the intraoperative cultures were Serratia marcescens, Stenotrophomonas maltophilia, and Burkholderia cepacia. After surgery, the patient was treated with antibiotics for 3 month. RESULTS: After 2 years of follow-up, the patient was free of pain, without signs of infection, and a correct fusion was achieved. CONCLUSION: When facing an infected vertebroplasty, initial conservative treatment with needle biopsy culture and antibiotic administration are a rational option to start. If this treatment fails, surgical debridement is then indicated in order to remove the infected tissue and the acrylic cement and to stabilize the spine. Although this can be an effective treatment, it could be a difficult and hazardous surgical procedure.