Total Knee Arthroplasty After Knee Arthroscopy in Patients Older Than 50 Years.

Several orthopedic registries have described the incidence of total knee arthroplasty (TKA) in patients who have undergone knee arthroscopy. Patient risk factors may play a role in the conversion rate from knee arthroscopy to TKA. This study quantifies the incidence of conversion of knee arthroscopy to TKA from a US mixed-payer database and describes some common patient risk factors for conversion. The medical records of more than 50 million patients who were treated between 1998 and 2014 were mined with a commercially available software platform. During the study period, a total of 68,090 patients older than 50 years underwent knee arthroscopy for partial meniscectomy, chondroplasty, or debridement. Reported rates of TKA at 1, 2, and 3 years after arthroscopy were 10.1%, 13.7%, and 15.6%, respectively. Obesity, depressive disorder, rheumatoid arthritis, diabetes, and age 70 years and older were associated with increased relative risk of conversion to TKA at 2 years. When obesity was combined individually with the top 5 other risk factors, no combination produced a higher relative risk than that of obesity alone. Patients who were 50 to 54 years of age had the lowest incidence of conversion to TKA (8.3%, P<.001). Men had a lower incidence of conversion to TKA (11.3%) than women (15.8%, P<.001). This information can help surgeons to counsel patients on the incidence of TKA after knee arthroscopy and identify preoperative risk factors that increase risk. [Orthopedics. 2016; 39(6):e1041-e1044.].

Modifiable Risk Factors in Patients With Low Back Pain.

Low back pain is one of the most common reasons for physician visits in the United States and is a chief complaint frequently seen by orthopedic surgeons. Patients with chronic low back pain can experience recurring debilitating pain and disability, decreasing their quality of life. A commercially available software platform, Explorys (Explorys, Inc, Cleveland, Ohio), was used to mine a pooled electronic health care database consisting of the medical records of more than 26 million patients. According to the available medical history data, 1.2 million patients had a diagnosis of low back pain (4.54%). The information was used to determine the incidence of low back pain in patients with a history of nicotine dependence, obesity (body mass index, >30 kg/m(2)), depressive disorders, and alcohol abuse. Relative risk was then calculated for the defined modifiable risk factors. Patients with nicotine dependence, obesity, depressive disorders, and alcohol abuse had a relative risk of 4.489, 6.007, 5.511, and 3.326 for low back pain, respectively, compared with patients without the defined risk factor. A statistically significant difference was found in the incidence of low back pain between all 4 groups with the risk factors evaluated and the general population (P<.05). By determining treatable patient risk factors for low back pain, physicians can monitor at-risk patients and focus on prevention and control of debilitating disease. These approaches can decrease the number of patients with isolated low back pain who are seen by orthopedic surgeons. [Orthopedics. 2016; 39(3):e413-e416.].

Risk factors for manipulation after total knee arthroplasty: a pooled electronic health record database study.

A commercially available software platform, Explorys (Explorys, Inc., Cleveland, OH), was used to mine a pooled electronic healthcare database consisting of the medical records of more than 27 million patients. A total of 229,420 patients had undergone a total knee arthroplasty; 3470 (1.51%) patients were identified to have undergone manipulation under anesthesia. Individual risk factors of being female, African American race, age less than 60, BMI >30 and nicotine dependence were determined to have relative risk of 1.25, 2.20, 3.46, 1.33 and 1.32 respectively. Depressive disorder, diabetes mellitus, opioid abuse/dependence and rheumatoid arthritis were not significant risk factors. African Americans under the age of 60 at time of TKA had the greatest incidence of MUA (5.17%) and relative risk of 3.73 (CI: 3.36, 4.13).

Advanced osteoarthritis in humans is associated with altered collagen VI expression and upregulation of ER-stress markers Grp78 and bag-1.

To test the hypothesis that a perturbation of endoplasmic reticulum (ER) function is involved in the pathogenesis of osteoarthritis (OA), articular cartilage was isolated from non-OA patients secondary to resection of osteo- or chondrosarcomas. Intra-joint samples of minimal and advanced osteoarthritic cartilage were isolated from patients undergoing total knee arthroplasty and scored for disease severity. Glucose-regulated protein-78 (grp78) and bcl-2-associated athanogene-1 (bag-1) were detected via immunofluorescence as markers of non-homeostatic ER function. Additionally, the expression of type VI collagen and its integrin receptor, NG2, was determined to examine cartilage matrix health and turnover. There was an upregulation of grp78 in advanced OA, and variable expression in minimal OA. Non-OA cartilage was consistently grp78 negative. The downstream regulator bag-1 was also upregulated in OA compared with normal cartilage. Collagen VI was mainly cell-associated in non-OA cartilage, with a more widespread distribution observed in OA cartilage along with increased intracellular staining intensity. The collagen VI integral membrane proteoglycan receptor NG2 was downregulated in advanced OA compared with its patient-matched minimally involved cartilage sample. These results suggest that chondrocytes exhibit ER stress during OA, in association with upregulation of a large secreted molecule, type VI collagen.