Limiting Factors for Indication of Hip and Knee Arthroplasty in Chile: The International Perception of Risk Initiative.

BACKGROUND: An aging population with a resultant higher incidence of osteoarthritis have increased the need for total hip (THA) and knee arthroplasty (TKA) worldwide. The purpose of this study was to explore what medical and social risk factors are considered relevant by Chilean orthopaedic surgeons in decisions regarding indications for THA or TKA. METHODS: An anonymous survey was sent to 165 hip and knee arthroplasty surgeons who were members of the Chilean Orthopedics and Traumatology Society. From a total of 165 surgeons, 128 (78%) completed the survey. The questionnaire included demographic data, place of work, and inquired about medical and socioeconomic factors that could affect surgical indications. RESULTS: Factors that limited indications for elective THA/TKA included body mass index (81%), elevated hemoglobin A1c (92%), lack of social support network (58%), and low socioeconomic status (40%). Most respondents made decisions based on personal experience or literature review rather than hospital or departmental pressures. Of the respondents, 64% believe that some patient populations would benefit from better care if payment systems adjusted for their socioeconomic risk factors. CONCLUSION: In Chile, limitations regarding the indication for THA/TKA are most influenced by the presence of modifiable medical risk factors such as obesity, uncompensated diabetes, or malnutrition. We believe that the reason surgeons limit surgeries for such individuals is to promote better clinical outcomes, and not in response to pressure from paying entities. However, low socioeconomic status was perceived to impair the ability to achieve good clinical outcomes by 40% of the surgeons.

Nutrition and Inflammation Influence 1-Year Mortality of Surgically Treated Elderly Intertrochanteric Fractures: A Prospective International Multicenter Case Series.

INTRODUCTION: Hip fracture is a common and devastating event in older adults causing increased dependence, comorbidity, and mortality. Since new surgical techniques have not significantly improved the mortality rate, a better understanding of patient risk factors could improve the treatment algorithm and outcomes. This prospective study aimed to document the 1-year survival rate of patients with intertrochanteric fracture treated surgically in Latin America and to investigate risk factors associated with 1-year mortality. PATIENTS AND METHODS: Between January 2013 and March 2015, 199 patients were prospectively enrolled. Inclusion criteria were aged 60 years or older, isolated intertrochanteric fracture (AO/OTA 31-A), and time to surgery within 10 days after injury. The follow-up period was 1 year. The association between mortality and patient demographics, comorbidity, surgical details, and preoperative laboratory parameters was assessed using log-rank tests. RESULTS: Twenty patients died by 365 days after surgery (including 5 that died within 30 days of surgery) resulting in a 1-year survival rate of 89.8% (95% confidence interval = 84.6-93.3). The 1-year mortality was significantly associated with age (≥85 years old, P = .032), existing comorbidity (P = .002), preinjury mobility level (P = .026), mental state (Mini-Mental State Examination > 23, P = .040), low preoperative plasma albumin level (P = .007), and high preoperative blood C-reactive protein level (CRP; P = .012). At the 1-year follow-up, patients on average did not regain their preinjury hip function and mobility, although the self-assessed quality of life was equal or better than before the injury. DISCUSSION: As a prospective study, the current patient population had clear inclusion and exclusion criteria and was relatively homogeneous. The resulting associations between 1-year postoperative mortality and preoperative hypoalbuminemia and preoperative elevated CRP level are therefore especially notable. Previously identified risk factors such as male gender and time to surgery showed no significant association with 1-year mortality-the overall favorable condition of the current population or the lack of statistical power maybe responsible for this observation. CONCLUSION: The current results showed that under the condition of optimal surgical treatment and low surgery-related complication, preinjury health status as indicated by the blood level of albumin and CRP has a direct and significant impact on 1-year mortality rate.

Primary total knee arthroplasty twenty years after distal femoral cement augmentation of a giant cell tumor.

We present a case of knee reconstruction 20 years after treatment of a giant cell tumor (GCT) with curettage and cementation. There is currently an ongoing debate whether cement or allograft bone is the preferred material for filling the void after GCT curettage. In this case we were able to readily implant a primary total knee replacement without disturbing the existing well-interdigitated large cement bolus and did not require any stems or augments for the reconstruction. Given the ease of TKR implantation in this patient, we feel that the use of cement following curettage of a GCT lesion is a better choice than allograft bone which may not provide enough structural support for the knee reconstruction and lead to a much more extensive procedure.

Clinical results of the conserve plus metal on metal hip resurfacing: an independent series.

The purpose of the present study was to report the clinical and radiographic results of an independent series of the Conserve Plus hip resurfacing. Five hundred forty-eight consecutive hip resurfacings were performed using the Conserve Plus prosthesis in 458 patients (350 males) with a mean age of 48.3 years (range 19 to 66). No patients were lost to follow-up. At a mean follow-up of 6.6 years (3.9 to 11.9) thirty (5.4%) hips required conversion to a total hip arthroplasty (THA) (20 males, 10 females, mean age=48.3±7.3 years). Five-year survival with as revision endpoint was 94.5% (95% CI: 93.5% to 95.5%). This study confirms the good clinical results previously reported with the Conserve Plus hip resurfacing device.

Factors associated with avascular necrosis of the femoral head and nonunion in patients younger than 65 years with displaced femoral neck fractures treated with reduction and internal fixation.

INTRODUCTION: Few studies have evaluated treatment of displaced femoral neck fractures in patients younger than 65 years, and risk factors for AVN or nonunion have not been clearly delineated within this age range. METHOD: To determine factors associated with avascular necrosis of the femoral head (AVN) and nonunion in patients younger than 65 years with displaced femoral neck fractures treated with reduction and internal fixation, we conducted a retrospective study of 29 displaced femoral neck fractures in 29 consecutive patients treated at a single institution. The influence of age, trauma energy, open reduction, and time from fracture to treatment on development of AVN and nonunion was evaluated. RESULTS: Patients who developed AVN were significantly older and suffered lower energy trauma than cases without AVN. No recorded variables were associated with nonunion. Logistic regression determined that only age was independently associated with AVN. Age was a good predictor for developing AVN, with a C statistics of 0.861, and a best cutoff determined at 53.5 years. CONCLUSION: Patients between 53.5 and 65 years presented a higher risk of AVN. A primary arthroplasty should be considered in this subgroup.

Autograft versus allograft with or without demineralized bone matrix in posterolateral lumbar fusion in rabbits. Laboratory investigation.

OBJECT: Posterolateral spinal fusions are performed to treat different spinal disorders. Autograft continues to be the gold standard; it is, however, associated with donor site morbidity and limited sources. Allograft has been used, but has been reported to result in lower fusion rates. Demineralized bone matrix (DBM) has also been used and reportedly increases the fusion rate in a variety of critical defect models. Different forms of DBM are available, not all have been independently studied. To evaluate the effect of a xenogenic DBM added to allograft on the fusion rate of posterolateral lumbar spine arthrodesis the authors designed an experimental study comparing posterolateral fusion rate using autograft, allograft, and allograft plus a xenogenic DBM in a validated animal model. METHODS: A bilateral, 1-level (L4-5) intertransverse process fusion was performed in 45 male New Zealand rabbits. Iliac crest bone graft was harvested bilaterally from each rabbit. The rabbits were randomly assigned to 3 groups: Group I, Autograft, 15 rabbits; Group II, Allograft, 15 rabbits; and Group III, Allograft plus DBM in a paste form (Dynagraft). The animals were killed 8 weeks after surgery. Fusion was assessed radiographically and by manual palpation by 2 independent observers. The results were analyzed using the Fisher exact test and chi-square test. RESULTS: The fusion rate was 46.6% (7 of 15 rabbits) in the autograft group, 33.3% (5 of 15 rabbits) in the allograft group, and 33.3% (5 of 15 rabbits) in the allograft plus DBM group (p > 0.05). CONCLUSIONS: Autograft produced a higher fusion rate than allograft in this spinal fusion rabbit model, but the difference was not statistically significant. Allograft plus xenogenic DBM showed the same fusion rate as allograft alone.

Closed reduction and iliosacral percutaneous fixation of unstable pelvic ring fractures.

OBJECTIVE: To report clinical results of patients treated with closed reduction and percutaneous iliosacral screw fixation for unstable pelvic ring fractures. MATERIALS AND METHODS: Retrospective study using medical records, images and late clinical assessment of all patients treated in our centre with percutaneous iliosacral screw fixation for unstable pelvic ring fractures, with a minimum follow-up of 12 months. Seventy-three patients with a mean age of 40.3 years old (range 14-70 years) were treated between July 1998 and December 2005. Seventy-one patients were included. Fractures types included 10 AO type B and 61 AO type C injuries. Forty-two patients had associated injuries. Mean follow-up was 31 months (12-96). Functional status was assessed using Majeed's grading score for pelvic fractures at final follow-up. RESULTS: Sixty-nine patients obtained a satisfactory initial reduction. Two patients had transitory postoperative neurological deficit. Five patients presented hardware failure. Fifteen patients developed sacroiliac osteoarthritis during follow-up. Good and excellent functional results were observed in 66 patients at final follow-up. Five patients had bad results, one due to infection of an anterior pelvic plate and the others due to painful refractory sacroiliac osteoarthritis that required a sacroiliac fusion. Sixty-one (86%) patients were able to return to pre-injury occupation. CONCLUSIONS: Good clinical results with a low and predictable rate of complications can be expected using closed reduction and percutaneous iliosacral screw fixation for unstable pelvic ring fractures.

Relevance of adjusted cut-off values in commercial serological immunoassays for Helicobacter pylori infection in children.

We assessed the sensitivity and specificity of H. pylori IgG and IgA with a commercial immunoassay performed in Chile and a second non-commercial immunoassay performed in a reference laboratory in the United States, in serum of 80 children and adults referred for gastrointestinal endoscopies in a developing country. Overall, 56% of the patients were infected with H. pylori based on rapid urease test and staining techniques on gastric biopsies. When Receiver Operator Curves (ROC) were developed, the sensitivity and specificity were similar for IgG and IgA. Both immunoassays exhibited better specificity, positive and negative predictive value (NPV) in children than in adults when cut-off values were corrected according to the local population than when they were assessed using the cut-off values pre-defined in other populations. These results underline the need to establish more precise cut-off values corrected in the local populations where assessments of antibodies as diagnostic markers of H. pylori infection are planning.