Design
The present study was part of a large prospective observational cohort study on knee complaints in general practice.9 Forty GPs from five municipalities in the southwest region of The Netherlands, participating in the Erasmus MC GP research network HONEUR, asked patients with all new knee complaints to participate in the general cohort study with a follow-up of 12 months. This network represents a total patient population of around 84 000 patients. Detailed information about the study design has been published elsewhere.9
Patients were included in the present study if the complaint was brought on by trauma within 5 weeks of presentation, and they were aged 18–65 years. These patients were asked to undergo MRI. Patients with MRI contraindications (pregnancy, metal implants, or a pacemaker) were excluded. Detailed information about the MRI protocol is also published elsewhere.10
Data collection
At baseline the patients filled in a questionnaire to collect data on age, sex, socioeconomic status, history of previous knee injuries and/or operations, general health, present symptoms, the mechanism of injury, the level of activity in both work and sports, and the management initiated by the GP at baseline.9 The severity of pain was assessed with a validated 11-point numeric rating scale (NRS) ranging from 0 (no pain) to 10 (unbearable pain).11 The Lysholm knee score provides information on instability and functional limitations such as walking and stair climbing.12 The Lysholm score ranged from 0 (worse) to 100 (best) and was obtained using a standard form, filled in by the patient. The Tegner knee function score (range 0–10) was used to determine the level of activity in work and sports prior to the knee injury.12
MRI was selected as the reference diagnostic test because it is highly accurate in detecting meniscal tears and ligament lesions.13,14 MRI was scheduled 2–6 weeks after the initial trauma, using a 1.0 Tesla General Electric device. Two radiologists determined the results of the MRI independently, based on a standardised classification form. The results of the MRI were also used to evaluate the diagnostic value of history taking and physical examination.15–17
After the MRI, a standardised physical examination was carried out by a trained physical therapist. Physical examination consisted of inspection, palpation, assessment of effusion, passive range of motion, meniscal tests, and ligament stability tests, and was performed in both the injured and the contralateral knee.9
How this fits in
Patients with complaints due to knee injuries are frequently seen in general practice however, outcome of these complaints is not well documented. From this study it emerges that the vast majority of these patients report clinically relevant recovery regardless of whether there is a meniscal tear, ligament lesion involved, or no damage at all. Therefore a wait-and-see policy as advocated by the Dutch guideline for traumatic knee disorders is recommended.
To avoid influencing the patient's behaviour or the GP's management, neither the patients nor their GPs were informed about the results of the MRI or physical examination during the 12 months' follow-up.
At 3, 6, and 12 months after the knee injury, a follow-up questionnaire was sent to the participating patients, who were asked to return the questionnaire by post. If patients did not return the questionnaire a reminder was sent by post, or a telephone call was made to the patient. These questionnaires collected data on medical consumption (GP consultations, referral to secondary care or to physical therapy). Also the severity of pain (NRS11) and the Lysholm12 scores were obtained. At 12 months' follow-up, the patients also reported on their perceived recovery using a 7-item Likert scale categorised as full recovery, major improvement, minor improvement, approximately equal, minor deterioration, major deterioration, and worse than ever. The categories full recovery and major improvement were defined as clinically relevant recovery.
Statistical analysis
The results are presented with descriptive statistics (frequencies, median, means, and standard deviation [SD]) using SPSS (version 11.0). The pain score and Lysholm score are presented for the total group and the subgroups with and without any lesion, as well as for four specific subgroups: isolated meniscal tear, isolated cruciate or collateral ligament lesion, or a combination. Perceived recovery is reported for the total group, as well as for the subgroups with and without any lesion.