Meniscus surgery is a high-volume surgery carried out on 1 million patients annually in the USA.1
The procedure is conducted on an outpatient basis and patients leave the hospital few hours after surgery. Nevertheless, little is known about the natural time course of patient perceived pain, function and quality of life (QOL) after meniscus surgery and which factors affect these outcomes.2
The general opinion is that patients recover their muscle strength fully within 6–12 weeks following arthroscopic partial meniscectomy.3–5
More importantly, however, recent studies have shown substantial patient-reported disability and pain in patients up to 4 years after surgery.6–8
One explanation for the poor self-reported outcomes may be that the loss of meniscal function triggers other events that may cause knee pain.9
Complicating the assessment of surgery effectiveness further, surgical procedures have shown to be associated with considerable ‘placebo effect’.10
A critical limitation of previous studies12–15
is their failure to account for the type of symptom onset (ie, injury mechanism). Meniscus tears can be categorised as either traumatic or non-traumatic. Traumatic tears (TT) are usually observed in younger, active individuals in an otherwise ‘healthy’ meniscus and joint, and can be attributed to a specific incident (eg, sports-related trauma).16
TT’s are often associated with joint effusion, reduced knee joint range of motion (ROM) together with catching/locking of the knee. Non-traumatic tears (NTT) are typically observed in the middle-aged (35–55 years) and older population.17
These tears are associated with meniscal calcification18
and risk factors for these tears include, presence of Heberdens's and Bouchard nodes, knee malalignment19
and occupational kneeling20
; however, the aetiology is largely unclear.16
NTT’s are often referred to as degenerative tears and have been shown to be associated with incipient knee osteoarthritis (OA) in the middle-aged or elderly population.21–23
Evidence from four well-designed trials demonstrated that arthroscopic interventions10
were no better or provided no additional effect, than the comparator (ie, sham surgery, physical therapy or a combination of physical and medical therapy) to relieve pain and improve function in the middle-aged patients with knee OA or early signs of knee OA. No corresponding randomised trials exist specifically for TT but an observational study showed that patients with degenerative meniscus lesions (ie, NTT) self-report worse function and QOL compared to individuals with TT at follow-up 14 years after meniscectomy.28
Thus, it is conceivable, but currently unproven, that arthroscopic meniscus surgery is more effective in resolving symptoms of a meniscus tear of traumatic aetiology compared with non-NTT in the middle-aged population.
In patients with TT, repair of the meniscus may be an alternative to resection. In contrast, repair is rarely an option for middle-aged patients with NTT due to the degenerative state of the meniscus. A recent retrospective observational study suggested a reduced risk of later knee OA and less activity level loss in patients (~32 years at time of surgery) undergoing repair compared with resection (ie, favouring repair).29
This indicates that patients with TT should be stratified into subgroups on the basis of type of arthroscopic intervention (ie, repair (TTREP
) and resection (TTRES
)) since this may influence the patient-perceived outcomes after surgery.
Aims and hypotheses
The primary aims of this observational cohort are to
- Investigate if improvements in patient self-reported pain, symptoms, function and QOL differ after arthroscopic meniscus surgery for non-traumatic meniscus tears in middle-aged patients, compared with surgery in patients with traumatic tears (ie, NTT vs TT). We hypothesise that in middle-aged patients with NTT arthroscopic surgery is less effective in relieving self-reported pain, symptoms, function in sports and recreation (Sport/Rec) and QOL (ie, change in KOOS scores), compared with younger patients undergoing surgery for TT.
- Investigate the effect of meniscus repair (TTREP) compared to meniscus resection (TTRES) on change in self-reported pain, symptoms, function in Sport/Rec and QOL in patients with TT. We hypothesise that arthroscopic surgery is less effective in relieving pain, symptoms, function in Sport/Rec and QOL (ie, change in KOOS scores) in patients undergoing TTRES compared with those undergoing TTREP.