Knee instability in patients with traumatic knee disorders: a cohort study in primary care.

BACKGROUND: There is a lack of knowledge about the course of knee instability in patients with traumatic knee disorders. OBJECTIVE: The aim of the study was to determine the course of traumatic knee instability during 1-year follow-up and to observe the treatment of knee instability by GPs. METHODS: Patients (n = 134) aged 18-65 years with traumatic knee disorders who consulted their GP within 5 weeks after trauma were enrolled in a prospective cohort study. Data were collected at baseline and at 3, 6 and 12 months follow-up. Magnetic resonance imaging (MRI) and physical examination of the knee were performed at baseline and at 1-year follow-up. RESULTS: At baseline, 28% of the 134 patients had no knee instability, 17% reported knee instability (according Lysholm score), 31% tested positive on knee instability (according Lachman test) and 24% both self-reported and tested positive on instability of the knee. At baseline and at 1-year follow-up, no clear differences between MRI findings, treatment and course of the defined groups of knee instability were found. At 1-year follow-up, patients with both self-reported and tested positive seemed to have worse outcomes. CONCLUSION: During 1-year follow-up, it was unclear if there were differences regarding course, treatment and MRI findings of the knee between no instability and the three defined knee instability groups. Statistical power was lacking in the comparisons made and therefore studies with more patients are needed.

Predictive factors for new onset or progression of knee osteoarthritis one year after trauma: MRI follow-up in general practice.

OBJECTIVE: To prospectively evaluate prognostic factors for new onset or progression of degenerative change on follow-up MRI one year after knee trauma and the association with clinical outcome. METHODS: Within a prospective observational cohort study in general practice, we studied a subgroup of 117 patients with acute knee trauma (mean age 41 years, 43% women). Degenerative change was scored on MRI at baseline and after one year follow-up. Multivariate logistic regression analysis was performed to evaluate prognostic factors for new onset or progressive degenerative change on follow-up MRI. Association between new or progressive degeneration and clinical outcome after one year was assessed. RESULTS: On follow-up MRI 15% of patients with pre-existing knee osteoarthritis showed progression and 26% of patients demonstrated new degenerative change. The only statistically significant prognostic variable in the multivariate analysis was bone marrow oedema on initial MRI (OR 5.29 (95% CI 1.64-17.1), p = 0.005). A significant association between new or progressive degenerative change and clinical outcome was found (p = 0.003). CONCLUSION: Bone marrow oedema on MRI for acute knee injury is strongly predictive of new onset or progression of degenerative change of the femorotibial joint on follow-up MRI one year after trauma, which is reflected in clinical outcome.

MRI follow-up of conservatively treated meniscal knee lesions in general practice.

OBJECTIVE: To evaluate meniscal status change on follow-up MRI after 1 year, prognostic factors and association with clinical outcome in patients with conservatively treated knee injury. METHODS: We analysed 403 meniscal horns in 101 conservatively treated patients (59 male; mean age 40 years) in general practice who underwent initial knee MRI within 5 weeks of trauma. We performed ordinal logistic regression analysis to analyse prognostic factors for meniscal change on follow-up MRI after 1 year, and we assessed the association with clinical outcome. RESULTS: On follow-up MRI 49 meniscal horns had deteriorated and 18 had improved. Age (odds ratio [OR] 1.3/decade), body weight (OR 1.2/10 kg), total anterior cruciate ligament (ACL) rupture on initial MRI (OR 2.4), location in the posterior horn of the medial meniscus (OR 3.0) and an initial meniscal lesion (OR 0.3) were statistically significant predictors of meniscal MRI appearance change after 1 year, which was not associated with clinical outcome. CONCLUSION: In conservatively treated patients, meniscal deterioration on follow-up MRI 1 year after trauma is predicted by higher age and body weight, initial total ACL rupture, and location in the medial posterior horn. Change in MRI appearance is not associated with clinical outcome.

Knee osteoarthritis in traumatic knee symptoms in general practice: 6-year cohort study.

AIM: To identify degenerative knee abnormalities using MRI and radiography 6 years after knee trauma, their relation with persistent knee symptoms and baseline prognostic factors. METHODS: Adults (18-65 years) with incident traumatic knee symptoms visiting their general practitioner were followed up for 6 years and underwent baseline MRI and 6-year follow-up MRI and radiography. Logistic regression was used to analyse associations between various degenerative abnormalities on 6-year MRI and radiography, persistent knee symptoms and baseline prognostic factors for knee osteoarthritis (OA) on 6-year MRI. RESULTS: On 6-year radiography, 60% of patients showed no OA, 28% showed OA with Kellgren&Lawrence (K&L) grade 1 and 13% showed with K&L grade 2. On 6-year MRI, 55% of patients showed cartilage defect(s), 45% showed osteophyte(s), 36% showed subchondral cyst(s), 40% showed bone marrow oedema, 21% showed meniscal subluxation, 83% showed meniscal degeneration,11% showed effusion and 11% showed a Baker's cyst. Of these, most were significantly related with 6-year radiographic K&L grade, while only lateral cartilage defect(s), medial osteophyte(s) and medial meniscal subluxation were significantly related with persistent knee symptoms. 32% of patients showed new onset or progressive knee OA on 6-year MRI, for which age, history of non-traumatic knee symptoms and bone marrow oedema at baseline were independent prognostic factors. CONCLUSIONS: Degenerative knee abnormalities on MRI are related to the K&L score; however, not all abnormalities are reflected in clinical outcome. Age, history of non-traumatic knee symptoms and bone marrow oedema predict knee OA 6 years after knee trauma, present in 32% of the patients.