Astronaut Back Pain; Nose-Knee Infection Connection; Running Two Room is Safe in TJA

Astronaut Back Pain

Whether you’re heading to the gym or thinking of hopping a future flight to Mars, results from a recent study offer unexpected insights regarding the role of soft tissue as a cause of back pain.

The work, “From the international space station to the clinic: how prolonged unloading may disrupt lumbar spine stability,” was named the 2017 Outstanding Paper Award Winner: Medical/Interventional Medicine by the Spine Journal. The research was published in the journal’s January 2018 edition.

Jeffrey C. Lotz, Ph.D., co-author on the work, and David S. Bradford, M.D., Endowed Chair in Orthopaedic Surgery at the Department of Orthopaedic Surgery at the University of California, San Francisco, told OTW, “Our academic research program has historically focused on back pain mechanisms and therapies for terrestrial populations—i.e., patients.”

“When we learned that astronauts have a high incidence of back pain in space, and disc herniation after returning to gravity, we were intrigued and interested in applying our knowledge to help NASA develop countermeasures for long duration space flight.”

“Because we would be studying how the human spine responds to a significant environmental exposure, microgravity, our expectation was that new knowledge coming from this research would benefit both NASA crew and the general population. Plus, it’s exciting to be part of a team of researchers that are helping NASA solve a significant health risk that may have important implications for future manned missions to Mars.”

“This is the first longitudinal imaging and functional study of humans before and after long-duration space travel. Because access to astronauts is so limited, there was a long process of study design administrative review and approval, particularly regarding radiation exposure (e.g. X-rays) and time requirements during the critical days immediately after return to Earth.”

“We intended to capture microgravity effects before crew re-acclimate to gravity, so getting scans and tests completed first, before other post-flight studies was crucial. This involved significant coordination with scores of other scientists that had studies approved for other health-related questions, such as vision impairment, body fluid shifts, and cardiovascular changes.”

“We also needed to get astronauts to volunteer to be subjects for our studies. This is because there are more science studies approved than there is time available by the crew, particularly within the first week after flight.”

“Consequently, our team needed to regularly ‘pitch’ our study to crew that are in the International Space Station pipeline (called the Informed Consent Briefing, ICB). This was aided by the fact that one of our co-investigators, Scott Parazynski, was a former astronaut who suffered from a post-flight disc herniation (while he was climbing Mount Everest no less).”

“Also, because access to crew was so limited, we needed to make difficult choices in our study design. We couldn’t do everything we proposed (PET/CT for example) as often as we wanted. So we had to negotiate compromises with NASA administration.”

“Given our knowledge of the physics of how spinal discs behave (they osmotically swell at night, and compress with gravity during the day) and anecdotal reports of spine lengthening after space flight, we expected to see that crew returned home with supra-physiologically swollen discs.”

“This wasn’t the case however (a fact that was also noted by a separate research team using in-flight ultrasound). Rather, we observed that there was a significant atrophy of spinal stabilizing muscles, despite the rigorous in-flight exercise program designed by NASA ASCR’s (Astronaut Strength, Conditioning and Recondition specialists). Even with such a small sample (our first 6 of 12 crew) we noted a strong, statistically significant relationship between paraspinal muscle atrophy, lumbar lordosis, and spinal segment stiffness.”

“We recently held the first-ever joint meeting between NASA flight surgeons, ASCR’s, astronauts, and researchers focused on spine health. Our goal was to combine our observations and make recommendations to NASA for pre- and post-flight screening protocols to track spine health. We also discussed pre-, post-, and in-flight countermeasures that could be instituted to minimize the deleterious effects of microgravity.”

“We have also begun applying our NASA observations to back pain patients. For example, we have recently observed that paraspinal atrophy is significantly associated with disability in a cohort of chronic back pain patients. These observations suggest that interventions being designed by NASA that target the core spine stabilizers may be effective to treat back pain in patients.”

“The results of this study emphasize the fact that the spine is stabilized by both passive tissues (disc, vertebra, ligaments, and facets) and active tissues (muscles), and that synergy between those two stabilizing systems is necessary for pain free function. When developing new diagnostic and therapeutic strategies to help back pain patients we most often talk about the passive tissues—but there is an important stabilizing role that the deep stabilizing muscles play. These muscles are often ‘innocent bystander’ tissues damaged by surgery, a fact that may impair post-operative functioning in surgery patients.”

Nose/Knee Infection Connection!

Ideally, says a new study, patients should be preoperatively screened for nasal bacteria colonization.

Researchers from the Icahn School of Medicine at Mount Sinai examined data from 716 patients who underwent nasal screening prior to joint replacement. Their work, “Risk Factors for Staphylococcus Aureus Nasal Colonization in Joint Replacement Patients,” appears in the December 29, 2017 edition of The Journal of Arthroplasty.

Calin S. Moucha, M.D., chief of Adult Reconstruction and Joint Replacement Surgery at The Mount Sinai Medical Center in New York and study co-author told OTW, “I treat a high number of periprosthetic joint infection cases and while caring for these patients is very gratifying, treatment is not easy and certainly not risk free.”

“Preventing infections should still be a top priority and optimizing patients preop by decolonization has been shown to be effective. Not every hospital or practice has the ability to screen and decolonize every patient, so we tried to identify patients at risk of staph colonization so that at least these high-risk patients can be screened and decolonized.”

The authors wrote, “This study is a retrospective review of 716 patients undergoing hip or knee replacement beginning in 2011. All patients were screened preoperatively for nasal colonization.”

Dr. Moucha commented to OTW, “We found that 17.5% of patients undergoing primary hip or knee replacement surgery screened positive for S. aureus. Diabetes, renal insufficiency, and immunosuppression are risk factors for such colonization. Given that these comorbidities are already known independent risk factors for periprosthetic joint infection, these patients should be particularly screened and when necessary, decolonized.”

“If you cannot screen and decolonize every total joint replacement patient at least focus resources on these high-risk patients. Patients with diabetes, renal disease, and immunosuppression are at risk! Screen, decolonize, and adjust antibiotic prophylaxis according to your patient’s skin flora. In addition, communicate at least yearly with your hospital’s epidemiologist/infection control teams and review your hospital’s antibiogram.”

Study: Running Two TJA Rooms Is Safe

While you wouldn’t want to be running from OR to OR during the most critical aspects of surgeries, new research indicates that overlapping rooms is safe.

The study, “Running Two Rooms” Does Not Compromise Outcomes or Patient Safety in Joint Arthroplasty,” appears in the January 15, 2018 edition of The Journal of Arthroplasty.

William G. Hamilton, M.D., hip and knee surgeon at Anderson Orthopaedic Clinic in Alexandria, Virginia, and co-author on this study, commented to OTW, “This topic is of interest to many players in orthopedics, including the media as well as the U.S. Congress. The impetus for initiating the study came from a 2015 Boston Globe article that featured the controversial topic on concurrent surgery, followed by a December 2016 report from the Senate Finance Committee where they concluded that more data was required on this subject. We initiated our study at that time to try and provide data on this timely topic.”

“Because we have tracked our total joint outcomes for many years, combined with the fact that surgeons from our institution have run both consecutive rooms (one operating room on one day) as well as overlapping rooms (two operating rooms with one surgeon going back and forth between them), we felt that we had the opportunity to provide data to help in the debate of this topic.”

The authors wrote, “Using an institutional database, all primary hip and knee arthroplasties from 2006-2016 were identified. Six surgeons performed a total of 16,916 cases, including 7,511 total hips and 9,405 knee arthroplasties.”

Dr. Hamilton told OTW, “We looked at over 16,000 total hip and total knee arthroplasties, with a fairly even split between consecutive and overlapping rooms, and found no statistical difference in the revision or reoperation rates between the two groups. We concluded that at our institution over 10 years there was no increased risk if surgeons performed overlapping rooms.”

“We must recognize that these results are from one institution and do not universally suggest that running two rooms is safe. Surgeons also should recognize that this practice refers to overlapping rooms, where we use the time it takes to transport, set up and break down the case in one room while a surgery is performed in the other room. We do not support the practice of ‘concurrent surgery,’ where critical portions of two surgeries are performed at the same time.”

“We also recommend that surgeons provide some form of informed consent to their patients and be prepared to educate our patients on the practice of overlapping rooms. As papers like ours are published and the media discusses this more, we must emphasize to our patients that we have their safety as our top priority. At the same time, performing overlapping rooms allows patients improved access to expert surgeons while increasing surgical efficiency and volume to the benefit of hospitals and surgeons alike.”