FEAR-AVOIDANCE AND SELF-EFFICACY PSYCHOSOCIAL FACTORS ARE ALTERED AFTER PARTIAL MENISCECTOMY AND ASSOCIATED WITH REHABILITATION OUTCOMES

Abstract

Background:

Little research has examined how psychosocial factors change over time and influence rehabilitation outcomes following meniscectomy. This information can inform the need to assess and address psychosocial factors in meniscectomy rehabilitation.

Hypothesis/Purpose:

The purpose of this study was to examine changes in fear-avoidance and self-efficacy psychosocial factors from pre-surgery to one year after meniscectomy and their associations with rehabilitation outcomes. The hypothesis was that psychosocial factors would improve following meniscectomy, and less improvement in psychosocial factors would be associated with less improvement in rehabilitation outcomes.

Study design:

Prospective cohort.

Methods:

Twenty-five patients with partial meniscectomy participated. Testing time points were pre-surgery, after post-surgical rehabilitation, and one-year post-surgery. Fear avoidance (pain catastrophizing and kinesiophobia) and self-efficacy (knee-related activity) psychosocial factors were assessed with the Pain Catastrophizing Scale (PCS), the Tampa Scale for Kinesiophobia (TSK-11), and Knee Activity Self-efficacy (KASE) questionnaires; respectively. Rehabilitation outcomes were quadriceps strength, evaluated with isokinetic testing at 60 °/sec; knee pain, measured with the Numeric Pain Rating Scale (NPRS); and self-reported knee function, measured with the International Knee Documentation Committee Subjective Knee Form (IKDC-SKF).

Results:

PCS scores improved from pre-surgery to after post-surgical rehabilitation, while TSK-11 and KASE scores improved from pre-surgery to after post-surgical rehabilitation and from after post-surgical rehabilitation to 1-year post-surgery. Pre-surgery PCS and KASE scores were associated with 1-year post-surgery NPRS score (r = 0.50) and quadriceps peak torque (r = 0.48), respectively. From pre-surgery to 1-year post-surgery, change in TSK-11 score was associated with change in NPRS score (r = 0.65), and change in KASE score was associated with change in IKDC-SKF score (r = 0.44). From pre-surgery to after post-surgical rehabilitation, changes in TSK-11 and KASE scores were associated with changes in NPRS (TSK-11, r = 0.47; KASE, r = -0.50) and IKDC-SKF scores (TSK-11, r = -0.39; KASE, r = 0.71). From after post-surgical rehabilitation to 1-year post-surgery, changes in KASE score was associated with changes in IKDC-SKF score (r = 0.59).

Conclusions:

Assessment of pain catastrophizing and knee activity self-efficacy pre-surgery might help to identify patients at risk for sustained knee pain and quadriceps muscle weakness. Decreasing kinesiophobia and increasing knee activity self-efficacy were associated with improved knee pain and function.

Level of Evidence:

2b

INTRODUCTION

At three months after partial meniscectomy, about half of patients report reduced levels of work or sports participation¹ and their self-reported knee function is 13% lower compared to age, gender and sports-matched controls.² Moreover, deficit in quadriceps strength is about 25% at 12 months after meniscectomy.³ Altered psychosocial factors including high fear-avoidance (kinesiophobia and pain catastrophizing) and low self-efficacy have been linked to rehabilitation outcomes such as quadriceps strength and knee function in various knee injury populations.^4-7 Only a few studies, all cross-sectional in design, have examined these psychosocial factors in the meniscectomy population.⁸ Elevated pain catastrophizing has been associated with lower peak knee extensor torque after traumatic meniscal tears⁹ and greater knee pain before and after meniscectomy rehabilitation¹⁰ while greater self-efficacy for knee activity has been associated with higher self-reported knee function⁸ and single leg hop performance after meniscectomy.¹¹ Psychosocial factors can change over time in a non-linear fashion.⁵ Therefore, longitudinal studies are needed to understand how fear-avoidance and self-efficacy psychosocial factors change over time and their association with changes in knee rehabilitation outcomes. Acquiring this knowledge can help evaluate the need to assess and address these psychosocial factors in patients undergoing rehabilitation after.

The purpose of this study was to examine changes in fear-avoidance and self-efficacy psychosocial factors from pre-surgery to one year after meniscectomy and their associations with rehabilitation outcomes. Based on previous literature, the hypothesis was that the psychosocial factors would improve following meniscectomy, and less improvement in psychosocial factors would be associated with less improvement in rehabilitation outcomes.

METHODS

Study Overview

This study was a secondary analysis of data from a randomized controlled trial (RCT) study that evaluated the association of quadriceps muscle function with self-reported knee function and cartilage structure following meniscectomy (Clinicaltrials.gov # NCT01879852). Demographic information was collected pre-surgery. Psychosocial factors questionnaire responses, and rehabilitation outcomes were collected at pre-surgery, immediately after post-surgical rehabilitation and 1-year post-surgery.

Subjects

Subjects with an isolated meniscal tear that underwent arthroscopic partial meniscectomy were recruited from the clinical practices of three board-certified orthopedic surgeons. Subjects were considered eligible if they were between the ages of 15 and 35 years, had a traumatic onset meniscal tear, and had surgery performed within 12 months of injury. Patients were excluded if they had bilateral injury, concomitant ligamentous injury, previous knee injury, articular cartilage defect > Grade II on Outerbridge scale^12,13 confirmed at the time of surgery, patellofemoral joint pain, or lower extremity alignment >5 ° valgus or varus. Outerbridge scale is the grading system for articular cartilage to describe the incidence of chondromalacia patellae and has subsequently been adapted for all chondral surfaces.^12,13 All subjects gave informed consent to participate in this study and the study has been approved by the Institutional Review Board.

Post-Surgical Rehabilitation

Rehabilitation was initiated within one-week post-surgery and administered for six weeks (12 visits total). Two licensed physical therapists supervised the rehabilitation interventions. Both physical therapists had a sports physical therapy board certification and had more than 10 years of clinical experiences. Subjects received standard rehabilitation alone or with additional quadriceps strengthening per the initial RCT study design. Standard rehabilitation consisted of interventions to address typical post-surgical impairments following meniscectomy, including knee range of motion (ROM) exercises, lower extremity strengthening, stretching and balance exercises (Table 1). Additional quadriceps strengthening consisted of neuromuscular electrical stimulation to the quadriceps muscle and eccentric overload during strengthening exercises involving the quadriceps muscle. Neuromuscular electrical stimulation was initiated at the first visit. Current characteristics were set as follows: pulse duration = 250 microseconds, frequency = 75 Hz, and on/off time  =  15/50 seconds.¹⁴ Current amplitude was adjusted to the maximally tolerated level of the subject.¹⁵ Ten electrically elicited contractions with the knee in full extension were performed at each visit. Eccentric exercises were added when the following criteria were met: (1) knee pain rating < 2/10, (2) effusion 1 + (Larger bulge on medial side with downstroke)¹⁶ or less, and (3) active knee motion from 0-90 °. The maximum load that could be performed by the injured leg for the concentric phase (straighten the knee) was determined and the resistance was then set to 130-150% of the concentric phase maximum. The goal was to overload quadriceps muscles in study subjects. Only the injured leg was used to perform the eccentric phase of the exercise, and the concentric phase of the exercise was performed with assistance as needed from the uninjured leg. Three sets of 10 repetitions were performed for each exercise. The exercise was progressed to 6 sets of 10 repetitions and the resistance was increased in the subsequent visit if no exacerbation of symptoms was noted. The goal was to overload quadriceps muscles in study subjects. The target training intensity at 130-150% was chosen, which was within the range that was recommended in literature (0-60% overload based on one-repetition maximum).¹⁷ The training repetitions were followed previous studies in patients with ACL reconstruction.^18,19

Table 1.

Interventions for standard rehabilitation and targeted quadriceps strengthening.

Interventions (both groups)	Standard rehabilitation	Targeted quadriceps strengthening
Knee range of motion	•10 quadriceps sets	•NMES§ × 10 quadriceps contractions
Straight leg raise (flexion, abduction)	•Leg press 0-90 °	•Leg press 0-90 °
Hamstring curls	-Resistance  =  80% concentric 1 RM†	-Resistance  =  150% concentric 1 RM
Calf raise	-Raise and lower with injured leg	-Raise both legs; lower injured leg
Lower extremity stretching*	•Knee extension 0-90 °	•Knee extension 0-90 °
Single leg balance	-Resistance  =  80% concentric 1 RM	-Resistance  =  150% concentric 1 RM
Squats to 45° (two legs)	-Raise and lower with injured leg	-Raise both legs; lower injured leg
Cryotherapy post exercise	•Forward step up	•Forward step up
	-2∼12-inch height‡	-2∼12 -inch height‡
	-Up and down with injured leg	-Up with injured leg, down with uninjured leg
	•Lateral side up	•Lateral heel tap
	-2∼12-inch height‡	-2∼12-inch height‡

^*Hamstring, iliotibial band, calf and quadriceps as able

^†One-repetition maximum

^‡2-inch height progressed to 12-inch height

^§Neuromuscular electrical stimulation: pulse duration = 250 microseconds, frequency = 75 Hz, and on/off time  =  15/50 seconds

Demographic Information

Demographic information included sex, age, height, weight, time from injury to surgery and location of meniscectomy.

Psychosocial Factor Questionnaires (Appendix A)

Pain catastrophizing was measured with the Pain Catastrophizing Scale (PCS). The PCS is a 13-item questionnaire that evaluates catastrophic thinking about pain. Items relate to rumination (eg, “I keep thinking about how much it hurts”), magnification (eg, “I wonder whether something serious may happen”), and helplessness (eg, “It's awful and I feel that it overwhelms me”) and are scored from 0 (“not at all”) to 4 (“all the time”). Total scores range from 0 to 52 points, and higher scores indicate higher levels of pain catastrophizing. Test-retest reliability coefficients for the PCS have been reported to be 0.93 in patients with low back pain.²⁰ The PCS has been used in knee injury research and is a valid and reliable measure for patients with anterior knee pain and in the later stage of ACL reconstruction rehabilitation.^21,22 The PCS is included in Appendix A.

Kinesiophobia was measured with the shortened version of the Tampa Scale for Kinesiophobia (TSK-11).²³ The TSK-11 is an 11-item questionnaire that evaluates subjects’ levels of pain-related fear. Items related to somatic focus (eg, “My body is telling me that I have something dangerously wrong”) and activity avoidance (eg, “I can't do all the things normal people do because it's too easy for me to get injured”) are scored from 1 (“strongly disagree”) to 4 points (“strongly agree”). Total scores range from 11 to 44 points, and higher scores indicate greater fear of movement or re-injury. Test-retest reliability coefficients for the TSK-11 have been reported to be 0.93 in patients with low back pain.²⁰ MCID for TSK-11 is 4 points in patients with low back pain.²³ Although the MCID for TSK-11 has not been described for patients with meniscectomy, TSK-11 has been used in knee injury research and is a valid and reliable measure for patients with anterior knee pain and in the early stage of ACL reconstruction rehabilitation.^21,22 The TSK-11 is also included in Appendix A.

Self-efficacy was measured with the Knee Activity Self-efficacy questionnaire (KASE).²⁴ The KASE is a 10-item questionnaire that was developed by the authors based on a published questionnaire. Items related to the confidence in performing functional activities (eg, “I can hop on the injured leg”) are scored from 1 (“strongly disagree”) to 10 points (“strongly agree”). Total scores range from 0 to 100 points, and higher scores indicate greater self-efficacy for knee activity. In patients with meniscectomy, KASE score are positively associated with self-reported knee function⁸ and single leg hop index.¹¹ Test-retest reliability for the KASE questionnaire was analyzed in 53 patients with ACL reconstruction who completed the questionnaire at 8 and 9 weeks post-surgery. The intra-class correlation coefficient was 0.85. The validity for KASE has not been established for patients with meniscectomy. The KASE is also included in Appendix A.

Rehabilitation Outcomes

Quadriceps strength was assessed with an isokinetic dynamometer (Biodex System3, Biodex Corporation, Shirley, NY) at the speed of 60 °/sec.²⁵ The range of motion was 10 ° to 100 °of knee flexion (0 ° was defined as full extension). Prior to testing, subjects performed 3 practice trials at 50% of maximal effort to familiarize themselves with the testing apparatus. After 1 minute of rest, subjects performed 3 trials at maximal effort. Verbal encouragement and visual feedback of the real-time torque output were provided to facilitate maximal effort.^26,27 Peak torque normalized to body mass (N-m/kg) was measured.

Knee pain intensity was measured with a numeric pain rating scale (NPRS). Rating scale ranges from 0 (“no pain”) to 10 (“worst imaginable pain”) points. Subjects rated their worst pain and best pain intensity in the previous week as well as their current pain intensity. The three pain ratings were averaged for analysis. Test-retest reliability coefficients for the NPRS have been reported to be 0.76 in patients with neck pain.²⁸

Self-reported knee function was measured with the International Knee Documentation Committee Subjective Knee Form (IKDC-SKF).²⁹ The IKDC-SKF is an 18-item questionnaire that measures knee symptoms (eg, “During the past 4 weeks, or since your injury, how stiff or swollen was your knee?”) and physical function (eg, “What is the highest level of activity you can participate in on a regular basis?”). Total scores range from 0 to100 points, and higher scores indicating less disability. Test-retest reliability coefficients for the IKDC-SKF have been reported to be 0.94 in patients with knee injuries.²⁹

Sample Size Calculation

A power calculation was performed with the intent on detecting changes in each psychosocial factor questionnaire scores using a power of 80% and a significant level of 5%. Based on preliminary data, the numbers needed to show changes in PCS score, TSK-11 and KASE scores were 18, 10 and 5 subjects, respectively.

STATISTICAL METHODS

All data were processed using a statistical software package (SPSS 20, IBM Co. Armonk, NY). Descriptive statistics were generated for demographics, psychosocial factor questionnaire scores, and rehabilitation outcomes. Separate repeated-measures analyses of variance assessed longitudinal changes in psychosocial factor questionnaire scores and rehabilitation outcomes from pre-surgery, after post-surgical rehabilitation to 1-year post-surgery. Pearson's Product Moment correlation assessed the association of (1) pre-surgery psychosocial factors with rehabilitation outcomes after post-surgical rehabilitation and 1-year post-surgery, (2) changes in psychosocial factors and changes in rehabilitation outcomes in the time intervals of pre-surgery to after post-surgical rehabilitation, after post-surgical rehabilitation to 1-year post-surgery and pre-surgery to 1-year post-surgery. An alpha level of 0.05 was set for significance in all statistical tests.

RESULTS

A total of 25 subjects were recruited. Demographic information for the subjects is presented in Table 2. The subjects included 22 males and 3 females. The mean height was 178.1 cm and the mean weight was 89.2 kg. The mean time from knee injury to surgery was 3.6 months, and over half of the subjects (68%) received medial meniscectomy.

Table 2.

Demographic information for the study population. Continuous variables are reported as mean (standard deviation).

	N = 25 (Males:22)
Age (years)	20.6 (4.8)
Height (cm)	178.1 (8.9)
Weight (kg)	89.2 (26.0)
Time from injury to surgery (months)	3.6 (3.0)
Location of surgery Medial meniscectomy Lateral meniscectomy	17 8
Medial meniscectomy	17
Lateral meniscectomy	8

Longitudinal Changes

Psychosocial factor questionnaire scores are shown in Table 3. Psychosocial factor questionnaire scores all significantly changed over a year, with more improvements in scores from pre-surgery to after post-surgical rehabilitation. Specifically, the PCS score decreased 5.4 points from pre-surgery to after post-surgical rehabilitation (p<0.01), but did not significantly change (0.3 point) from after post-surgical rehabilitation to 1-year post-surgery. The TSK-11 score significantly decreased 4.7 points from pre-surgery to after post-surgical rehabilitation (p<0.01) and 2 points from after post-surgical rehabilitation to 1-year post-surgery (p = 0.01). The KASE score significantly increased 25 points from pre-surgery to after post-surgical rehabilitation (p<0.01) and 10.3 points from after post-surgical rehabilitation to 1-year post-surgery (p<0.01).

Table 3.

Psychosocial factors at pre-surgery, after post-surgical rehabilitation, and 1-year post surgery. Values are given as mean with standard deviation (in parentheses) and confi dence interval [in brackets].

	PCS* (points)	TSK-11† (points)	KASE§ (points)
Pre-surgery	11.8 (8.1) [8.4,15.2]	24.0 (5.6) [21.7, 26.4]	56.0 (19.9) [47.8, 64.3]
After post-surgical rehabilitation	6.4 (7.3) [3.4, 9.4]	19.3 (5.2) [17.1, 21.5]	81.0 (15.8) [74.5, 87.6]
1-year post-surgery	6.1 (7.1) [3.2, 9.1]	17.3 (4.7) [15.4, 19.3]	91.3 (10.4) [87.0, 95.6]

^*Pain Catastrophizing Scale

^†Tampa Scale for Kinesiophobia-11

^§Knee Activity Self-efficacy

Rehabilitation outcomes are shown in Table 4. Two subjects did not complete quadriceps strength assessment at pre-surgery. Quadriceps peak torque did not significantly increase from pre-surgery to after post-surgical rehabilitation but increased substantially from after post-surgical rehabilitation to 1-year post-surgery (p<0.001). Conversely, the NPRS score decreased 2.5 points from pre-surgery to after post-surgical rehabilitation (p<0.01) but did not significantly change (0.2 point) from after post-surgical rehabilitation to 1-year post-surgery. The IKDC-SKF score significantly increased 21.4 points from pre-surgery to after post-surgical rehabilitation (p<0.01) and increased an additional 16.6 points from after post-surgical rehabilitation to 1-year post-surgery (p<0.01).

Table 4.

Rehabilitation outcomes at pre-surgery, after post-surgical rehabilitation, and 1-year post-surgery. Values are given as mean with standard deviation (in parentheses).

	Quadriceps peak torque (N-m/kg)	NPRS* (points)	IKDC-SKF† (points)
Pre-surgery	1.8 (0.6) [1.5, 2.0]	3.4 (2.2) [2.5, 4.3]	52.6 (18.8) [44.8, 60.4]
After post-surgical rehabilitation	1.9 (0.6) [1.6, 2.1]	0.9 (0.8) [0.6, 1.3]	74.0 (14.4) [68.1, 80.0]
1-year post-surgery	2.3 (0.6) [2.1, 2.6]	0.7 (0.8) [0.4, 1.1]	90.6 (7.3) [87.6, 93.6]

^*Numeric Pain Rating Scale

^†International Knee Documentation Committee Subjective Knee Form

Association with Rehabilitation Outcomes

Pre-surgery

Higher pre-surgery PCS score was associated with higher NPRS score at 1-year post-surgery (r = 0.50, p = 0.01), and higher pre-surgery KASE score was also associated with greater quadriceps peak torque at 1-year post-surgery (r = 0.48, p = 0.02).

Interval from pre-surgery to 1-year post-surgery

Decrease in TSK-11 score was associated with decrease in NPRS score (r = 0.65, p<0.01; Figure 1), and increase in KASE score was associated with increase in IKDC-SKF score (r = 0.44, p = 0.03; Figure 2).

Figure 1.

Association of changes in Tampa Scale of Kinesiophobia-11 (TSK-11) score and changes in Numeric Pain Rating Scale (NPRS) score in the interval of pre-surgery to 1-year post-surgery (r = 0.65, p<0.01).

Figure 2.

Association of changes in Knee Activity Self-efficacy (KASE) score and changes in International Knee Documentation Committee Subjective Knee Form (IKDC-SKF) score in the interval of pre-surgery to 1-year post-surgery (r = 0.44, p = 0.03).

Interval from pre-surgery to after post-surgical rehabilitation

Decrease in TSK-11 score was associated with decrease in NPRS score (r = 0.47, p = 0.02; Figure 3), and associated with increase in IKDC-SKF score (r = -0.39, p = 0.05). Also, increase in KASE score was associated with decrease in NPRS score (r = -0.50, p = 0.01), and associated with increase in IKDC-SKF score (r = 0.71, p<0.01; Figure 4).

Figure 3.

Association of changes in Tampa Scale of Kinesiophobia-11 (TSK-11) score and changes in Numeric Pain Rating Scale (NPRS) score in the interval of pre-surgery to after post-surgical rehabilitation (r = 0.47, p = 0.02).

Figure 4.

Association of changes in Knee Activity Self-efficacy (KASE) score and changes in International Knee Documentation Committee Subjective Knee Form (IKDC-SKF) score in the interval of pre-surgery to after post-surgical rehabilitation (r = 0.71, p<0.01).

Interval from after post-surgical rehabilitation to 1-year post-surgery. Increase in KASE score was associated with increase in IKDC-SKF score (r = 0.59, p = 0.02).

DISCUSSION

This study examined longitudinal changes in fear-avoidance and self-efficacy psychosocial factors over 1 year after meniscectomy and the associations with rehabilitation outcomes. As hypothesized, all psychosocial factors improved post-operatively. Larger improvements occurred from pre-surgery to immediately after post-surgical rehabilitation, with continued improvement up to 1-year post surgery for kinesiophobia and knee activity self-efficacy. Associations specific to each psychosocial factor were also found. For example, higher level of pain catastrophizing at pre-surgery was statistically significantly associated with greater knee pain intensity at 1-year post-surgery, while higher level of knee activity self-efficacy at pre-surgery was statistically significantly associated with greater quadriceps strength at 1-year post-surgery. Moreover, the improvement in kinesiophobia was statistically significantly associated with the improvement in knee pain, and the improvement in knee activity self-efficacy was statistically significantly associated with improvements in knee pain and function. These results extend previous research from different knee injury populations^5,30-32 and support the potential for a broad link between these psychosocial factors and rehabilitation outcomes. The findings of this study suggest that these psychosocial factors might need to be assessed and addressed in meniscectomy rehabilitation to optimize rehabilitation outcomes.

Fear-avoidance psychosocial factors improved across the 1-year time interval, but the trajectory of change was slightly different for pain catastrophizing and kinesiophobia. PCS scores improved the most from pre-surgery to after rehabilitation, and the magnitude of improvement achieved the MCID reported for patients undergoing cognitive behavioral therapy for pain catastrophizing (3.2 to 4.5 points).³³ The PCS score did not show further significant change at 1-year post-surgery in part because the mean score was 6.3 points after post-surgical rehabilitation, which is close to the minimum score (0 points). The TSK-11 also showed a large improvement from pre-surgery to after post-surgical rehabilitation and further improved up to 1-year post-surgery. These findings agree with previous ACL research showing the largest improvement in TSK-11 scores in in the first month after surgery.³⁴ Interestingly, the TSK-11 score at 1 year post-surgery (17.3 points) in this study was comparable to the score reported for patients at 1-year after ACL reconstruction (14.6 and 15.4 points)³⁵ and the cut-off score reported for patients at 4-year after ACL reconstruction (14.5 points).³⁶ Although surgery and rehabilitation are less extensive for meniscectomy than for ACL reconstruction, it appears that they both evoke fear-avoidance beliefs. The cut-off score to identify higher kinesiophobia after meniscectomy has not been established, but higher kinesiophobia has been increasingly considered to be related to return to sports and physical activity levels in ACL reconstruction population.³⁷ Future research is needed to explore the cutoff score for meniscectomy patients and investigate if rehabilitation outcomes would be affected for those with higher kinesiophobia after meniscectomy.

Knee activity self-efficacy also improved across the 1-year time interval. The KASE score demonstrated a substantial improvement from pre-surgery to after post-surgical rehabilitation and continued to show further improvement at 1-year post-surgery. The mean KASE score was lower in subjects with meniscectomy at 1-year post-surgery than that reported in ACL reconstruction.²⁴ In terms of the magnitude of improvements, the increase in KASE score from pre-surgery and after post-surgical rehabilitation was 25 points (from 56 to 81 points) in the meniscectomy subjects compared to 13 and 20 points (from 80 to 93 points and from 67 to 87 points) in patients with ACL reconstruction.²⁴ Subjects who have undergone meniscectomy, which is a less severe knee injury and surgery than ACL reconstruction, would potentially be more confident in performing knee-related functional activities soon after surgery and rehabilitation. It should be noted that although the KASE score statistically decreased over time, it is not clear whether the subjects achieved the clinically meaningful improvement because minimal clinically important differences in self-efficacy is still unknown. Future research should examine the clinically meaningful change in self-efficacy to determine whether additional psychosocial intervention is needed.

As depicted in the biopsychosocial model, psychosocial factors are important influences on rehabilitation outcomes. It may be beneficial to screen pain catastrophizing in patients with meniscectomy pre-surgery as there was an association with pain intensity that has also been found in many other patient populations.^22,38 In addition, an association between self-efficacy at pre-surgery and quadriceps peak torque at 1-year post-surgery was observed. It is possible that subjects with higher level of self-efficacy³⁹ were more adherent to rehabilitation, which may result in increased quadriceps muscle strength. From pre-surgery to after post-surgical rehabilitation, kinesiophobia and knee activity self-efficacy were both related to knee pain and self-reported function while from pre-surgery to 1-year post-surgery, kinesiophobia and knee activity self-efficacy were related with knee pain and self-reported function, respectively. When exposed to potential painful activities, subjects with decreased kinesiophobia and increased self-efficacy may tend to confront and plan strategies to cope with their pain, which enables them to have greater exercise tolerance and engage more in activities. This potential mechanism may minimize their pain intensity and enhance their perceived recovery of knee function. As knee pain intensity did not significantly change after post-surgical rehabilitation, kinesiophobia needs to be monitored from pre-surgery to after post-surgical rehabilitation for potentially improving knee pain intensity. Knee activity self-efficacy appears to be more relevant to knee function and needs to be examined across the 1-year time interval. With the examination of the associations between psychosocial factors and rehabilitation outcomes, this study highlights the importance of monitoring specific psychosocial factors at different time periods throughout the rehabilitation process. However, causal relationship cannot be inferred from this study. Future research could investigate the predictive value of pain catastrophizing and self-efficacy for early identification of those with sustained knee pain and prolonged quadriceps muscle weakness after meniscectomy.

A strength of this study is longitudinal collection of psychosocial data over 12 months in a homogeneous population of patients with traumatic isolated meniscal tear. Conversely, most meniscectomy studies had shorter follow up and included patients with both traumatic or degenerative meniscal tears. This study has limitations to consider when interpreting the results. First, multivariate analyses were not performed to test predictive relationship between psychosocial factors and rehabilitation outcomes due to the number of subjects. Also, most of the subjects were injured while playing sports, but level of sports participation was not evaluated which may have influenced psychosocial factors.⁴⁰ Results might vary for subjects with different levels of sports participation.⁴¹

CONCLUSION

Pain catastrophizing, kinesiophobia and knee activity self-efficacy improved over one year after meniscectomy, particularly from pre-surgery to immediately after post-surgical rehabilitation. Assessment of pre-surgical pain catastrophizing and knee activity self-efficacy might help to identify patients at risk for sustained knee pain and prolonged quadriceps muscle weakness. In addition, a lack of post-surgical improvement in kinesiophobia and knee activity self-efficacy could contribute to persistent knee pain and poor knee function recovery. Clinical practice guidelines have encouraged screening psychosocial factors that may affect rehabilitation treatment decision making.⁴² Prior research has not acknowledged which psychosocial factors should be monitored during meniscectomy rehabilitation, and clinicians may neglect to evaluate psychosocial factors. Current study suggests that pain catastrophizing, kinesiophobia and knee activity self-efficacy psychosocial factors should be included as part of standard assessment following meniscectomy. Future research in larger samples is necessary to determine those patients who require psychosocial oriented interventions to improve meniscectomy rehabilitation outcomes.

Appendix A