Osteoarthritis after major combat trauma: the Armed Services Trauma Rehabilitation Outcome Study

Abstract

Objective: To investigate the differences in clinical and radiographic knee OA markers between injured and uninjured UK service personnel. Methods: This study was a cross-sectional analysis, 8 years post-injury, of a prospective cohort study. The Knee Injury and Osteoarthritis Outcome Scores (KOOS), radiographic Kellgren and Lawrence (KL) scores and Osteoarthritis Research Society International scores (joint space narrowing, sclerosis, osteophytes) were obtained from 565 uninjured and 579 matched (on sex, age, rank, regiment and role on deployment) major combat injured participants from the Armed Services Trauma Rehabilitation Outcome study; 35 had a knee injury and 142 had an amputation without knee injury. Kruskal-Wallis tests were used to compare between groups for KOOS and radiographic measures. A multiple logistic regression was performed on the effects of injury on radiographic features. Results: The mean age at injury was 25.7 years (s.d. 5.2). Injured participants demonstrated worse KOOS values for pain {median 89 [interquartile range (IQR) 72-100] vs 94 [83-100]} and symptoms [median 80 (IQR 60-90) vs 85 (70-95), P < 0.001] and higher scores for radiographic variables than uninjured participants. Injured non-amputated/non-knee-injured participants had worse KOOS values than uninjured participants [pain: 92 (IQR 75-100) vs 94 (83-100); symptoms: 80 (IQR 60-90) vs 85 (70-95), P < 0.01]. Knee-injured participants had worse KOOS values [pain: 67 (IQR 55-85), symptoms: 55 (IQR 35-73), P < 0.001] than all subgroups and worse radiographic measures than injured non-amputated participants. KL score (≥1) and sclerosis were worse for amputees than injured non-amputated participants. Amputees had 4.04-fold increased odds (95% CI 2.45, 6.65) vs uninjured participants and knee-injured participants had 4.06-fold increased odds (95% CI 1.89-8.74) than uninjured participants of knee osteoarthritis (KOA; KL ≥1). Injured participants (without knee injury/amputation) had 1.74-fold (95% CI 1.27, 2.69) increased odds of KOA than uninjured participants. Conclusion: Major combat trauma (in addition to knee injury or amputation) has a substantial effect on the development of KOA.