Exercise as it relates to Disease/Do sporting injuries in your youth lead to arthritis in older age?
This is an analysis of “Joint Injury in Young Adults and Risk for Subsequent Knee and Hip Osteoarthritis” by Gelber et al (2000).
What is the Background to this Research?
Osteoarthritis is a significant health issue worldwide and is a major cause of morbidity, disability and pain. Research of youth sporting injuries and an increased risk of developing osteoarthritis in older age may assist to develop and evaluate interventions for prevention. Osteoarthritis is a degenerative condition that effects the loading bearing joints of the hip, knee and ankle, and also the hands and spine. It can involve the damage and loss of cartilage, remodelling of bone, osteophyte formation, weakened ligaments and muscles and synovial inflammation. It is the most common form of arthritis in Australia with an increase in prevalence with older adults. Osteoarthritis is the leading cause of hip and knee replacement.  Primary symptoms are joint pain, stiffness and movement limitations. Initially the joint pain is during and after activity increasing to with negligible movement and when resting, with joint failure and disability.
Where is the Research from?
The study was undertaken at the Johns Hopkins University School of Medicine in Baltimore, Maryland. The article was published in the journal the Annals of Internal Medicine, which is a peer reviewed medical journal. 
What kind of Research was this?
This study was a prospective cohort study conducted over 47 years. The objective was to examine the relationship between joint injury and the incident of knee and hip osteoarthritis.  A prospective cohort study is the observation of a group of similar individuals and followed prospectively over a time period to observe the outcome of a condition in relation to a suspected risk factor. According to the Levels-of-Evidence rating, the study of Joint Injury in Young Adults and Risk for Subsequent Knee and Osteoarthritis  is catergorised as a level II, which demonstrates a valid and substantial study.
What did the Research involve?
The research involved 1337 medical students of the graduating class of 1948 to 1964 at the Johns Hopkins University of Medicine. At entry to the study participants underwent a standard history and examination, including assessment of history of trauma, musculoskeletal disorders, physical activity, weight and height and body mass index. Injury was defined as trauma to the knee or hip joint, including internal damage and fracture. They were followed prospectively with annual self-administered questionnaires till 1995. A median follow up of 36 years. 
What were the Basic Results?
Over a follow up of a median of 36 years.
141 participants reported joint injuries
• Knee alone 111
• Hip alone 16
• Knee and hip 14
96 developed osteoarthritis'
• Knee alone 64
• Hip alone 27
• Knee and hip 5
The cumulative incidence of knee osteoarthritis by 65 years
• Knee injury during adolescence/young adulthood 13.9%
• No injury 6%
Joint injury at cohort entry or during follow-up substantially increased the risk for subsequent osteoarthritis. 
How did the Researchers Interpret the Results?
The researchers determined that the findings demonstrated that there was a relationship between young adults with traumatic injury to the knee joint and a substantial increased risk of future knee osteoarthritis later in life. Injury to the knee and hip joint that occurred during middle age observed during during follow up also demonstrated an increase in incidence of later osteoarthritis in the joint. 
There are several limitations of the studies. Assessment of sex specific risk was not possible due to the small number women in the study, with a small number in the medical cohort at that time. The study could not be generalised to other occupations, as the group followed were only physicians. This could in effect underestimate the burden of osteoarthritis associated with joint injury in the general population. Another limitation was that information of family history was not incorporated and some cases of osteoarthritis were self-reported. 
What Conclusions can we take from this Research
Osteoarthritis is a significant issue worldwide and is becoming an increasing burden of disease on society. Research has consistently found that youth with joint injuries are at a substantially increased risk of developing osteoarthritis later in life. Evaluation of early intervention strategies in youth injuries may significantly impact the risk of developing osteoarthritis later in life and should be targeted for prevention strategies. Researchers indicate that further research is needed to assess the different mechanisms and risk factors that contribute to predisposition to developing osteoarthritis in older adults. These include the types of injuries, sporting and occupational activities, interventions and subsequent development of osteoarthritis. Further research is important to inform management and treatment of youth with joint injuries to prevent osteoarthritis as older adults.
What are the Implications of this Research?
The research has outlined the substantial increased risk of osteoarthritis following a youth joint injury for osteoarthritis later in older age. Youth with joint injuries are an ideal population to target for development and evaluation of strategies for osteoarthritis preventation.  On presentation of joint injuries in youth, treating medical and allied health practitioners can educate clients on possible implications and recommend treatment and exercise modifications to reduce future complications and interventions to prevent long term effects. They can advocate for safer sports equipment and sport practices.
For further information about this article, please contact: Dr. Gelber: Johns Hopkins University School of Medicine, 1830 East Monument Street, Suite 7500, Baltimore, MD 21205.
Other resources include:
• http://www.arthritisaustralia.com.au/ - An organisation which provides support and information to Australians living with arthritis
• http://www.aihw.gov.au/osteoarthritis/ - For further information and statistics on Osteoarthritis
1. Gelber AC, Hochberg MC, Mead LA, Wang N, Wigley FM, Klag MJ. Joint Injury in Young Adults and Risk for Subsequent Knee and Hip Osteoarthritis. Ann Intern Med. 2000;133:321–328. doi: 10.7326/0003-4819-133-5-200009050-00007
2. Australian Institute of Health and Welfare. What is osteoarthritis? [Internet]. Canberra: Australian Government; 2016 [cited 2017 September]. Available from: http://www.aihw.gov.au/osteoarthritis/what-is-osteoarthritis/
3. AOA (Australian Orthopaedic Association) 2017. Australian Orthopaedic Association National Joint Replacement Registry. Annual Report. Adelaide: AOA. Available from https://aoanjrr.sahmri.com/documents/10180/397736/Lay%20Summary%20Hip%20and%20Knee%20Replacement
4. March LM, & Bagga H. Epidemiology of osteoarthritis in Australia. 2004. Medical Journal of Australia, 180(5), S6.
5. Conchie H, Clark D, Metcalfe A, Eldridge J, Whitehouse M. Adolescent knee pain and patellar dislocations are associated with patellofemoral osteoarthritis in adulthood: A case control study. 2016 Aug;23(4):708-11. doi: 10.1016/j.knee.2016.04.009.
6. Dulay GS, Cooper C, Dennison EM. Knee pain, knee injury, knee osteoarthritis & work. Best Practice & Research Clinical Rheumatology, 2015. Volume 29 , Issue 3 , 454 - 461.
7. Richmond SA, Fukuchi RK, Ezzat A, Schneider K, Schneider G, Emery CA. Are joint injury, sport activity, physical activity, obesity, or occupational activities predictors for osteoarthritis? A systematic review. J Orthop Sports Phys Ther. 2013 Aug;43(8):515-B19.
8. National health and Medical Research Council. NHMRC additional levels of evidence and grades for recommendations for developers of guidelines. NHMRC. 2009. Available from: https://www.nhmrc.gov.au/_files_nhmrc/file/guidelines/developers/nhmrc_levels_grades_evidence_120423.pdf
9. Blagojevic M, Jinks C, Jeffery A, Jordan KP. Risk factors for onset of osteoarthritis of the knee in older adults: a systematic review and meta-analysis. Osteoarthritis Cartilage 2010;18:24–33. doi:10.1016/j.joca.2009.08.010
10. Englund M, Lohmander L.S. Risk factors for symptomatic knee osteoarthritis fifteen to twenty-two years after meniscectomy. Arthritis Rheum. 2004; 50: 2811–2819.