Causes of Accelerated Knee OA
Is accelerated knee osteoarthritis (KOA) so different from typical knee OA that it is a distinct disorder?
A new study, “Glucose homeostasis influences the risk of incident knee osteoarthritis: Data from the osteoarthritis initiative,” in the October 2017 edition of the Journal of Orthopaedic Research tackles that very question.
Jeffrey B. Driban, Ph.D., A.T.C., C.S.C.S., a researcher in the Division of Rheumatology at Tufts Medical Center, told OTW, “Most people think of knee osteoarthritis (OA) as a disease that develops gradually over several years. However, about 3.4% of adults at risk for knee osteoarthritis will develop an accelerated form of the disease.”
“Accelerated knee osteoarthritis is the onset of advanced-stage disease within 4 years and typically in less than 12 months. Accelerated knee OA is a painful disorder and associated with several risk factors; including greater age, greater body mass index (BMI), recent knee injury, static knee malalignment, and greater coronal tibial slope.”
“Since greater age and BMI may influence a person’s risk for accelerated knee osteoarthritis and alter systemic inflammation and glucose homeostasis we tested whether a systemic measure of inflammation or glucose homeostasis was associated with the development of accelerated or typical knee osteoarthritis. We focused on these measurements because they could be easily collected in a clinical setting among people we thought may be at risk for knee osteoarthritis.”
“An interesting aspect of our study design was the use of the Osteoarthritis Initiative (OAI), which is a public-private sponsored multicenter study that is in part supported by the NIH [National Institutes of Health]. The OAI recruited almost 4,800 people with or at risk for symptomatic knee osteoarthritis and annually collected clinical measures, biospecimens, and medical images (X-rays and MRIs) for the first four years. This study offers a unique opportunity to study accelerated knee osteoarthritis.”
The authors wrote, “We conducted a case-control study using the Osteoarthritis Initiative’s baseline and first four annual visits. All participants had no radiographic KOA at baseline (Kellgren-Lawrence [KL] < 2). We classified three groups: (i) incident accelerated KOA: >1 knee developed advance-stage KOA (KL Grade 3 or 4) within 48 months; (ii) incident typical KOA: > 1 knee increased in radiographic scoring within 48 months (excluding those with accelerated KOA); and (iii) No KOA: no change in KL grade by 48 months.”
“We found that glucose homeostasis may predict individuals at risk for incident typical knee osteoarthritis but not accelerated knee osteoarthritis. Furthermore, we detected a nonlinear relationship, where individuals with very low or very high levels of glycated serum protein were more likely to develop typical knee osteoarthritis.”
“Overall, this line of research is highlighting the need to be proactive with patients over 45 years of age who report knee symptoms or a recent joint injury without radiographic evidence of tibiofemoral disease. These patients should be frequently monitored over the next few years for changes in joint symptoms and structure. Measuring glucose homeostasis may help identify people at risk for developing typical knee osteoarthritis over the next four years but it won’t help identify people at risk for accelerated knee osteoarthritis.”
“Within the context of our prior work, we believe that impaired glucose homeostasis is associated with typical knee osteoarthritis while biomechanical factors (e.g., coronal tibial slope and static alignment) and certain recent injuries may relate with incident accelerated knee osteoarthritis.”
Lumbar Prolapse Caused Deficits
As if extreme back pain wasn’t enough, some unfortunate patients who experience a lumbar disc prolapse will go on to have serious neurological issues.
A new study, “Clinical and radiological factors related to the presence of motor deficit in lumbar disc prolapse: a prospective analysis of 70 consecutive cases with neurological deficit,” appears in the October 2017 edition of the European Spine Journal.
Rajasekaran Shanmuganathan, F.R.C.S., Ph.D., with the department of spine surgery at Ganga Hospital in Coimbatore, India and co-author, commented to OTW, “Lumbar disc prolapse is the most common cause for a consultation in our group. While more than 80% of patients get better with conservative treatment, a few of them can develop complications of which neurological deficit is the most serious. Even with surgery, many of them do not recover fully. Therefore it is important that we identify the subset of patients who are at risk for developing a neurological deficit, as they require a careful observation and intervention if necessary. The knowledge of patients at risk for neurology [issues] will also help the surgeon to counsel the patient appropriately.”
“This is a large prospective study: 70 consecutive patients with motor deficits are taken as the study group and compared with the matched group of 70 patients with intact neurology. Both groups were correlated for a huge number of clinical and radiological parameters.”
“The results showed that development of neurology [issues] in lumbar disc prolapse was multi-factorial. Patients with diabetes, a higher-level disc, sequestrated or superiorly migrated discs, large central discs, greater AP [anterio-posterior] dimension of the disc protrusion, primary canal stenosis and greater canal compromise, all had significant correlation. Rather than single factors, the presence of four of the above factors had a higher chance of motor deficit (specificity = 77% and sensitivity=74%).”
“Surgeons should counsel the patients relevantly and discuss with them the high chance of neurology [issues] if any four of the above factors are present.”
“Orthopedic surgeons should be aware that neurological deficit is a multifactorial etiology and a combination of the risk factors increases the propensity for the deficit.”
Sealants Over Sutures?
The newest alternative to sutures is injectable…a super sticky sealant has been developed by scientists from multiple institutions around the globe.
These researchers hail from many disciplines, including chemical engineering, thoracic surgery, and physics. Their work, “Engineering a highly elastic human protein–based sealant for surgical applications,” appears in the October 4, 2017 edition of Science Translational Medicine.
Ali Khademhosseini, Ph.D., a co-author on the study and associate faculty member at Harvard’s Wyss Institute for Biologically Inspired Engineering, told OTW, “This project came about from a meeting between myself, Nasim Annabi (now at Northeastern University) and Tony Weiss from the University of Sydney. We started to discuss how we can make stronger gels and came up with using elastin molecules that Dr. Weiss developed and crosslinking them using a light chemistry that we had previously used. Thus the concept came from linking expertise from around the world.”
The authors wrote, “…we engineered a biocompatible and highly elastic hydrogel sealant with tunable adhesion properties by photocrosslinking the recombinant human protein tropoelastin. The subcutaneous implantation of the methacryloyl-substituted tropoelastin (MeTro) sealant in rodents demonstrated low toxicity and controlled degradation. All animals survived surgical procedures with adequate blood circulation by using MeTro in an incisional model of artery sealing in rats, and animals showed normal breathing and lung function in a model of surgically induced rat lung leakage. In vivo experiments in a porcine model demonstrated complete sealing of severely leaking lung tissue in the absence of sutures or staples, with no clinical or sonographic signs of pneumothorax during 14 days of follow-up.”
Dr. Khademhosseini commented to OTW, “This glue will be useful for a range of applications that involve closing incisions. It has stronger mechanics and higher adhesiveness than the currently used glues.”
“The beauty of a MeTro formulation is that, as soon as it comes in contact with tissue surfaces, it solidifies into a gel-like phase without running away. We then can further stabilize it by curing it on-site with a short light-mediated crosslinking treatment. This allows the sealant to be very accurately placed and to tightly bond and interlock with structures on the tissue surface,” said Nasim Annabi, Ph.D., assistant professor of chemical engineering at Northeastern University, in the October 4, 2017 news release from the Wyss Institute
Dr. Khademhosseini, also a professor at Harvard-Massachusetts Institute of Technology’s Division of Health Sciences and Technology and Brigham and Women’s Hospital, noted, “In our in vivo studies, MeTro seems to remain stable over the period that wounds need to heal in demanding mechanical conditions and later it degrades without any signs of toxicity; it checks off all the boxes of a highly versatile and efficient surgical sealant with potential also beyond pulmonary and vascular suture and staple-less applications.”
