Physical function in patients undergoing arthroscopic meniscus surgery of the knee

Abstract

Current evidence does not support the primary use of arthroscopic partial meniscectomy (APM) in the treatment of middle-aged patients with a meniscus tear in a degenerative knee. Findings of these studies are based on Patient Reported Outcome Measures (PROMs). Objective functional performance in patients undergoing APM are poorly reported and research has not been consolidated on this topic. Arthroscopic meniscus surgery continues to be a frequently performed procedure despite recent guidelines; the rationale for surgical treatment in patients with meniscus injuries is not clearly defined. The aim of this thesis was to investigate expectations, functional performance and activity level in a cross sectional population of patients undergoing arthroscopic meniscus surgery of the knee. Two systematic reviews were undertaken to summarise current research on this topic. The first systematic review examined self-reported function and measures of strength in young patients undergoing APM. The second systematic review and meta-analyses examined measures of objective physical function in patients undergoing arthroscopic meniscus surgery. A longitudinal cohort study (Trinity Meniscus Study: TRIMS) examined objective and self- reported function in patients undergoing arthroscopic meniscus surgery. Pre-operative baseline assessments were carried out, and patients were followed up for one year post- operatively with PROMs measured at pre-op, three, six and twelve months post-op. Objective measures of physical function were assessed at pre-op baseline and six months post-op follow up. Functional performance was measured using isokinetic strength assessment of the quadriceps and hamstring muscles, as well as a battery of hop tests (Single Leg Hop(SLH), Triple Hop for Distance (THD) and Six-metre Timed Hop(6MH)). Performance was compared to contralateral leg as control and change in physical function over time was reported. Rationale for arthroscopic meniscus surgery was examined in a study collecting self- reported expectation questionnaires from patients and clinicians. Additional analyses of data from the TRIMS study was also used to compare reasons for surgery from patients' and surgeons' perspectives. Literature review found that objective measures of functional performance are poorly studied across all age groups undergoing arthroscopic meniscus surgery. Strength appears to be decreased for up to one year following APM in younger adults, but there is a complete lack of self-reported outcome data in younger populations. Deficits in functional performance are reported both pre and post-operatively in middle aged APM cohorts and RCTs. The TRIMS study found deficits in functional performance compared to contralateral leg, both pre-operatively (P<.01 all measures) and post-operatively (P<.05 all measures) in middle aged patients undergoing APM. These functional deficits were found to improve bilaterally following surgery but no difference in improvement was found on strength or SLH performance compared to contralateral leg. This indicated that deficits still exist following APM, despite bilateral functional improvements. In contrast to strength and SLH findings, high-level performance assessments (6MH and THD) revealed greater improvements in the APM leg, compared to the contralateral leg over time in the TRIMS study (P<.05). Examination of clinician and patient rationale for surgery found that physiotherapists and surgical team members had varied expectations of APM outcome, regardless of clinician discipline. Orthopaedic team members who had a larger yearly caseload of APM patients had a higher expectation of improvement following surgery. Surgeons and patients within the TRIMS cohort reported different perspectives on the reason for surgery, indicating that improvements are need in shared decision making, in order to optimise patient compliance and functional outcome of arthroscopic meniscus surgery. Improvements in functional performance are important to patients undergoing APM, and objective functional performance is previously underreported. This thesis found that functional performance deficits which exist pre-operatively, are not fully resolved at six months post-operatively. While there is a bilateral improvement in strength and a resolution of self-reported physical activity level; this does not reach a 'healthy normal' level and only high performance measures of 6MH and THD were found to improve significantly more than control. Functional performance deficits appear to remain six months following APM.