Predictive factors for 12-month outcome after anterior cruciate ligament reconstruction

The influence of body mass index on physical activity engagement following anterior cruciate ligament reconstruction: A systematic literature review

Background

The objective of this study was to summarize available literature that explored the impact of body mass index (BMI) on physical activity participation among individuals who were subjected to the anterior cruciate ligament reconstruction (ACLR).

Methods

A total of three electronic databases, including Web of Science, Scopus, and PubMed, were comprehensively searched to identify relevant investigations. The following inclusion criteria were applied: (1) study design was observational; (2) participants underwent the ACLR; (3) BMI was estimated as a predictor variable; and (4) outcomes evaluated referred to physical activity. The risk of bias was assessed with the National Institutes of Health Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies.

Results

After a database search, 787 studies were found, and only 10 of them met each of the eligibility criteria and were included in the qualitative analysis. Regarding respondents' characteristics, 7171 individuals underwent ACLR, 4080 males and 3091 females, with a mean age of 25.5 years. Most importantly, the average BMI of the examined population was 24.9 kg/m2. In all studies, physical activity was evaluated subjectively using the Tegner activity scale and the Marx activity scale. The main findings unambiguously demonstrated that a negative relationship between BMI and physical activity engagement was observed. More specifically, there is convincing evidence that BMI over 25 kg/m2 harmfully affected subjectively assessed physical activity in individuals with a history of ACLR.

Conclusion

The results obtained in the presented research indicated that increased values of BMI were a factor that correlated with reduced physical activity levels in the ACLR population. Hence, taking into account the clinical and health implications of reduced physical activity participation, stimulation of a healthy lifestyle, such as a combination of adequately designed physical exercise and nutrition, seems necessary for the analyzed population.

Quadriceps strength, patellar tendon quality, relative load exposure, and knee symptoms in male athletes before the anterior cruciate ligament reconstruction

Introduction

Anterior cruciate ligament (ACL) injuries cause knee instability, knee pain, weight-bearing adjustments, and functional deficits but their association to patellar tendon quality is unknown. Our purpose was to investigate quadriceps strength, patellar tendon quality, relative load exposure, perceived knee stability, knee pain, extension angle, and time from ACL injury; in addition to examining their relative associations.

Methods

Injured and uninjured legs of 81 male athletes of different sports with a unilateral ACL injury (18-45 years) were examined. Participants reported location and intensity of knee pain and their perceived stability using a numerical rating scale (NRS 0-10). Strength was tested with an isokinetic device. Tendon quality was measured using ultrasound tissue characterization. Means ± standard deviation (SD) of perceived knee stability, knee extension angle, knee pain, isokinetic quadriceps strength in relation to body mass, proportion of echo-types (I-IV), tendon volume, and number of days from ACL injury to assessment are reported. Values of effect sizes (ES) and correlations (rs) were calculated.

Results

ACL injured leg demonstrated reduced reported knee stability (6.3 ± 2.5), decreased knee extension angle (-0.7 ± 3.1° vs. -2.7 ± 2.2°; ES = 0.7; P < 0.001), greater knee pain (NRS 3.1 ± 2.2 vs. 0.0 ± 0.1; ES = 2.0; P < 0.001), and 22% lower quadriceps strength (228.0 ± 65.0 vs. 291.2 ± 52.9 Nm/kg: ES = 1.2; P < 0.001) as compared to the uninjured leg. However, patellar tendons in both legs displayed similar quality. Quadriceps strength was associated with stability (rs = -0.54; P < 0.001), pain (rs = -0.47; P < 0.001), extension angle (rs = -0.39; P < 0.001), and relative load exposure (rs = -0.34; P < 0.004). Echo-types distribution was beneficially associated with time from ACL injury (rs range: -0.20/ -0.32; P < 0.05).

Discussion

ACL injured athletes displayed knee pain, extension deficit, and weaker quadriceps in the injured leg. While there were no differences in patellar tendon quality between legs, longer time from ACL injury showed better tendon quality.

Preoperative predictors for return to physical activity following anterior cruciate ligament reconstruction (ACLR): a systematic review

BACKGROUND

Rates of return to physical activity after anterior cruciate ligament reconstruction surgery are sub-optimal. Optimising presurgical treatment may improve return rates. The purpose of this systematic review was to identify modifiable preoperative predictors for return to physical activity after anterior cruciate ligament reconstruction.

METHODS

Seven electronic databases (CINAHL, MEDLINE and SPORTDiscus via EBSCOhost, AMED, PsycINFO and EMBASE via OVID and Web of Science) were searched from inception to 31 March 2023. The population of focus was adults aged 18-65 who had undergone primary anterior cruciate ligament reconstruction. Studies needed to identify at least one potential modifiable preoperative predictor variable and the relationship between the predictor(s) and return to physical activity. All time-points of assessment and study designs were included. Data extraction was completed by one reviewer and verified by a second reviewer. Two reviewers completed the risk of bias assessment using the Quality in Prognostic Studies tool and Grading of Recommendations Assessment, Development and Evaluation system.

RESULTS

The search identified 2281 studies, eight met the inclusion criteria. Five studies scored 'high', and three studies scored 'moderate' risk-of-bias. All preoperative predictors were of very low-quality evidence. Five different outcome measures were used to assess return to physical activity including Tegner, Marx, Physical Activity Scale, return to play at the elite level and return to preinjury level (undefined). This was measured between 1- and 10-years post-surgery. Nine preoperative physical, six psychosocial and five demographic/clinical factors were assessed and four were found to be predictive. These included quadriceps strength, psychological profile, patient estimated ability to return and graft type (patella tendon, BPTB).

CONCLUSION

Very-low level evidence suggests that increasing quadriceps strength, managing patient expectations of their treatment outcomes, improving motivation to resume preinjury activity levels and considering the use of a BPTB graft will support return to physical activity after ACLR.

TRIAL REGISTRATION

This study was prospectively registered in PROSPERO: CRD 42020222567.

Preoperative quadriceps muscle strength deficit severity predicts knee function one year after anterior cruciate ligament reconstruction

Quadriceps strength is critical for patients with anterior cruciate ligament (ACL) reconstruction; however, little is known about the relationship between preoperative quadriceps strength deficit and postoperative subjective knee functions. The study aimed to investigate the relationship between preoperative quadriceps strength and postoperative knee function in patients after ACL reconstruction. Seventy-five male patients with primary ACL reconstruction surgery with hamstring autografts between 2014 and 2017 were included. An isokinetic dynamometer assessed quadriceps strength while self-reported knee functions were measured by the International Knee Documentation Committee (IKDC) and Lysholm scores at baseline and 1 year after surgery. The three identified groups (Q1-Q3) were classified according to the preoperative quadriceps muscle strength deficit. Q1 were patients with < 25% quadriceps muscle strength deficit, Q2 showed a 25-45% deficit, and Q3 included those with a deficit > 45%. We compared knee functions between the three groups and examined the associations between preoperative variables and functional knee outcomes. The preoperative quadriceps muscle strength deficit had a negative association with the knee functional scores at 1 year follow-up including the IKDC score (r_s = - 0.397, p = 0.005) and the Lysholm score (r_s = - 0.454, p < 0.001), but not other factors. Furthermore, only the Q1 group, with < 25% deficit in preoperative quadriceps muscle strength, showed a significant correlation in postoperative IKDC score (r = - 0.462, p = 0.030), and Lysholm score (r = - 0.446, p = 0.038). Preoperative quadriceps muscle strength deficit had a significant negative relationship with postoperative function at 1 year following ACL reconstruction.

Physical prognostic factors predicting outcome following anterior cruciate ligament reconstruction: A systematic review and narrative synthesis

BACKGROUND

Anterior cruciate ligament (ACL) injuries are common. Many patients undergo ACL reconstruction (ACLR), with rehabilitation key to successful outcome. Understanding physical prognostic factors is integral to clinical decision-making, but factors predicting outcome are inadequately defined. The objective was to establish physical prognostic factors predicting outcome following ACLR.

METHODS

A systematic review following a published protocol (CRD42019127732) searched MEDLINE, CINAHL, EMBASE, key journals and grey literature to November 28, 2020. Prospective cohort studies, participants ≥16 years of age who had undergone ACLR were included, with multi-ligament and/or ACL repair surgery, and studies not published in English excluded. Two independent reviewers conducted searches, extracted data, assessed risk of bias (QUIPS) and overall quality of evidence (GRADE). Meta-analysis was not possible, therefore narrative synthesis was performed.

RESULTS

13 studies (16 articles) were included (1 low, 12 high risk of bias). Low-level evidence supports postoperative degenerative changes and poor lower-limb strength predicting poorer outcome long term (KOOS). Very low-level evidence supports greater postoperative quadriceps strength predicting improved functional performance medium term; with lower body mass index predicting improvement of multiple outcome measures.

CONCLUSION

Limited evidence of low or very low-level indicates multiple prognostic factors predicting outcome following ACLR. A high-quality prognostic study is required.

Postoperative Pain Is Associated With Psychological and Physical Readiness to Return to Sports One-Year After Anterior Cruciate Ligament Reconstruction

Purpose

To identify whether any patient factors, injury factors, or symptom severity scores are associated with either psychological or physical readiness to return to sport after anterior cruciate ligament reconstruction (ACLR).

Methods

Consecutive patients with an ACL injury that required surgical treatment were included in this study. All patients completed the single-legged hop testing and the Anterior Cruciate Ligament Return to Sport Index (ACL-RSI) at 1 year postoperatively. Multivariable regression analysis models were used to determine whether an independent relationship existed between baseline patient factors (age, sex, BMI, preinjury Marx Activity Score), injury factors (meniscal tear and chondral injury), physical symptoms (Knee Injury and Osteoarthritis Outcome Score [KOOS] for pain and symptoms), and the dependent variables of physical and psychological readiness to return to sport (single-legged hop and ACL-RSI).

Results

Of the 113 patients who were included, 37% were female, and the mean age of our population was 28.2 years (SD = 8.1). Multivariable regression models demonstrated that patient-reported pain symptoms at 1 year postoperatively, as measured by the KOOS pain subscale, was significantly associated with both ACL-RSI score (Beta estimate: 1.11 [95% CI: .62-1.60] P < .001) and the ability to pass the single-legged hop test (OR: 1.07 [95% CI: 1.004-1.142] P = .037).

Conclusions

Patients with higher reported pain levels at 1 year following ACLR have lower psychological and physical readiness to return to sport.

Level of Evidence

Level 3, retrospective cohort study.

Quadriceps strength to body weight ratio is a significant indicator for initiating jogging after anterior cruciate ligament reconstruction

BACKGROUND

Quadriceps strength recovery after anterior cruciate ligament (ACL) reconstruction is an important criterion for progress in rehabilitation and return to sports. The purpose of this study was to determine whether quadriceps strength to body weight ratio (QS/BW) is a significant indicator for initiating jogging after ACL reconstruction.

METHODS

Isokinetic quadriceps strength at 60°/s was measured and a jogging trial was completed 3 months after ACL reconstruction with hamstring tendon autograft in 83 patients (36 male, 47 female; mean age, 26.6 ± 12.4 years). Based on the jogging trial results, patients were assigned to either a successful jogging group (mean velocity ≥ 9 km/h) or an unsuccessful jogging group (mean velocity < 9 km/h). The association between QS/BW and successful jogging after surgery was investigated by multivariate logistic regression analysis and the cut-off value was determined by receiver operating characteristic analysis.

RESULTS

Forty-four patients (53.0%) were assigned to the successful jogging group and 39 (47.0%) to the unsuccessful jogging group. QS/BW was independently associated with initiating jogging 3 months after surgery. The cut-off value of QS/BW for successful jogging was 1.45 Nm/kg (area under the curve = 0.94; sensitivity = 88.6%, specificity = 87.2%). All of the patients who initiated jogging with QS/BW of > 1.45 Nm/kg at 3 months returned to sports without recurrence or contralateral injury by 10 months after surgery.

CONCLUSIONS

QS/BW is a significant indicator for safely initiating jogging 3 months after ACL reconstruction. The cut-off value of QS/BW for initiating jogging was 1.45 Nm/kg.

Higher Body Mass Index Adversely Affects Knee Function After Anterior Cruciate Ligament Reconstruction in Individuals Who Are Recreationally Active

OBJECTIVE

Our aim was to investigate the effect of body mass index (BMI) levels on quadriceps and hamstring strength and functional outcomes up to 6 months after anterior cruciate ligament reconstruction (ACLR) with hamstring tendon autograft (HTG).

DESIGN

Prospective, controlled study.

SETTING

University clinical laboratory.

PATIENTS

Ninety-one participants who had undergone unilateral ACLR with HTG were divided into 2 groups according to their BMI. The participants whose BMI were between 18.5 and 24.9 kg/m were included in group 1 (n = 50, age: 27.2 ± 6.7 years, BMI: 22.3 ± 1.6 kg/m) and those whose BMI > 24.9 kg/m were included in group 2 (n = 41, age: 30.2 ± 6.9 years, BMI: 28.0 ± 2.4 kg/m).

INTERVENTIONS

Quadriceps and hamstring strength, functional performance including hop, jump, and balance performance, and IKDC score.

MAIN OUTCOME MEASURES

Maximum voluntary isometric contraction of the quadriceps and hamstring muscles and the body mass were measured at 1, 3, and 6 months after surgery. Absolute peak torques and normalized peak torques to body weight for both limbs were recorded. Functional outcomes were evaluated at 6 months after surgery.

RESULTS

Normalized quadriceps strength improvement was lower in group 2 when compared with group 1 (F(2,178) = 6.23, P = 0.003). Group 2 also demonstrated lower scores in functional performance (P < 0.05). Normalized hamstring and absolute quadriceps and hamstring strength improvement was not affected by higher BMI level (P > 0.05).

CONCLUSIONS

Higher BMI levels adversely affect quadriceps strength capacity and performance in patients who have undergone ACLR with HTG. Clinicians should consider BMI levels of patients when assessing and targeting muscle recovery because it could negatively affect the success of the ACLR rehabilitation.

Lateral extra-articular tenodesis in patients with revision anterior cruciate ligament (ACL) reconstruction and high-grade anterior knee instability

BACKGROUND

Additional lateral extra-articular procedures can reduce the risk of failure of primary anterior cruciate ligament reconstruction (ACLR). There is limited evidence on the effect of lateral extra-articular procedures in revision ACL surgery. The purpose of this study was to evaluate the clinical outcome of patients with lateral extra-articular tenodesis (LET) in combination with revision ACLR for combined ACL graft failure and high-grade anterior knee instability.

METHODS

Between 2016 and 2018, 75 patients with graft failure after primary ACLR and high-grade anterior knee instability who received revision ACLR were included in the retrospective study. High-grade anterior knee instability was defined as high-grade pivot-shift or side-to-side difference of more than six millimeters in Rolimeter®-testing. An additional modified Lemaire tenodesis was performed in 59 patients during revision ACLR. Seventy-three patients were clinically examined with a minimum of two years after revision surgery.

RESULTS

Failure of the revision ACLR occurred in 8.2% (n = 6) of the cases. LET lead to significant decreased failure rates (five percent vs. 21%, p = .045) and decreased incidence of a positive pivot-shift in patients with revision ACLR and high-grade anterior knee instability in comparison to patients without LET. Also, postoperative functional scores were significantly increased in the group of additional LET.

CONCLUSIONS

Additional LET in patients with revision ACLR and high-grade anterior instability significantly reduces the risk of failure of revision ACLR, the incidence of pivot-shift and increases postoperative functional outcome.

Is Pre-operative Quadriceps Strength a Predictive Factor for the Outcomes of Anterior Cruciate Ligament Reconstructions

Persistent quadriceps weakness prevents patients from returning to sports after ACL reconstruction. Pre-operative quadriceps strength was indicated as an important factor for the outcomes of ACL reconstruction. However, the existing evidence is controversial. Therefore, this systematic review was conducted to summarize and evaluate the relationship between pre-operative quadriceps strength and the outcomes following ACL reconstruction, and to summarize the predictive value of pre-operative quadriceps strength for satisfactory post-operative outcomes. Pubmed, WOS, Embase, CINAHL and SportDiscus were searched to identify eligible studies according to PRISMA guidelines. Relevant data was extracted regarding quadriceps strength assessment methods, pre-operative quadriceps strength, participants treatment protocols, post-operative outcomes, follow-up time points and the relevant results of each individual study. Twelve cohort studies (Coleman methodology score: 62±10.4; from 44-78) with 1773 participants included. Follow-up period ranged from 3 months to 2 years. Moderate evidence supports the positive association between pre-operative quadriceps strength and post-operative quadriceps strength; weak evidence supports the positive association between pre-operative quadriceps strength and post-operative functional outcomes. By now, there is no consensus on the predictive value of pre-operative quadriceps strength for achieving satisfactory quadriceps strength after ACLR. To conclude, pre-operative quadriceps strength should be taken into consideration when predict patient recovery of ACLR.

Improving Maximal Strength in the Initial Postoperative Phase After Anterior Cruciate Ligament Reconstruction Surgery: Randomized Controlled Trial of an App-Based Serious Gaming Approach

Background

Anterior cruciate ligament reconstruction surgery is one of the most common orthopedic procedures. One of the main factors that influence the outcome is regaining strength in the postoperative phase. Because anterior cruciate ligament reconstruction surgeries are often performed in young patients, we combined the concept of prehabilitation with an app-based serious gaming approach to improve maximal strength postoperatively.

Objective

Our objective was to conduct a prospective randomized trial to evaluate whether an app-based active muscle training program (GenuSport Knee Trainer) can improve postoperative strength by starting rehabilitation immediately after primary anterior cruciate ligament reconstruction surgery.

Methods

We designed a pilot study in which we randomly assigned patients receiving primary anterior cruciate ligament reconstruction to either the serious gaming training (intervention) group or a conventional rehabilitation (control) group. Except for the serious gaming-based training, both groups followed the same postoperative treatment protocol. Outcome parameters were absolute and relative change in maximal strength, as well as the International Knee Documentation Committee Subjective Knee evaluation form, Knee Injury and Osteoarthritis Outcome Score, and Lysholm Knee Score.

Results

In total 26 patients agreed to participate (14 patients in the intervention group and 12 patients in the control group, 1 of whom was lost to follow-up). We noted a difference in absolute maximum strength between the exergaming intervention and the control groups. Mean maximum strength preoperatively was 155.1 (SD 79.2) N in the intervention group (n=14) and 157.0 (SD 40.8) N in the control group (n=11). Postoperative mean maximum strength was 212.8 (SD 78.5) N in the intervention group and 154.5 (SD 27.1) N in the control group. Mean absolute change in maximum strength was 57.7 (SD 95.2) N in the intervention group and –4.8 (22.2) N in the control group. The analysis of covariance model with absolute change as the dependent variable and treatment group and baseline maximum strength as covariates showed a relevant difference in relative change between treatment groups (intervention – control) of 59.7 N (95% CI 10.1-109.3; P=.02). Similarly to the absolute increase, the relative change in maximum strength was relevantly higher in the exergaming group. The mean relative change in maximum strength was 1.7 (SD 1.17) in the intervention group and 1 (SD 0.13) in the control group. No adverse events or problems were reported during the study period.

Conclusions

Implementation of an app-based active muscle training program in the early postoperative therapy scheme was associated with an improvement in maximal strength. Therefore, we considered the use of GenuSport training after anterior cruciate ligament reconstruction to be a helpful complement to rehabilitation after anterior cruciate ligament reconstruction surgery to improve strength in the early postoperative phase. To our knowledge this was the first study to analyze immediate postoperative serious gaming-based training with the GenuSport device based on strength improvement.

Preoperative medial knee instability is an underestimated risk factor for failure of revision ACL reconstruction

PURPOSE

The purpose of this study was to carefully analyse the reasons for revision ACLR failure to optimize the surgical revision technique and minimize the risk of recurrent re-rupture. Large studies with a minimum of 2 years of follow-up that clinically examine patients with revision ACLR are rare.

METHODS

Between 2013 and 2016, 111 patients who underwent revision ACLR were included in the retrospective study. All patients were examined for a minimum of 2 years after revision surgery (35 ± 3.4 months, mean ± STD) and identified as "failed revision ACLR" (side-to-side difference ≥ 5 mm and pivot-shift grade 2/3) or "stable revision ACLR".

RESULTS

Failure after revision ACLR occurred in 14.5% (n = 16) of the cases. Preoperative medial knee instability (n = 36) was associated with failure; thus, patients had a 17 times greater risk of failure when medial knee instability was diagnosed (p = 0.015). The risk of failure was reduced when patients had medial stabilization (n = 24, p = 0.034) and extra-articular lateral tenodesis during revision surgery (n = 51, p = 0.028). Increased posterior tibial slope (n = 11 ≥ 12°, p = 0.046) and high-grade anterior knee laxity (side-to-side difference > 6 mm and pivot-shift grade 3, n = 41, p = 0.034) were associated with increased failure of revision ACLR. Obese patients had a 9 times greater risk of failure (p = 0.008, n = 30).

CONCLUSION

This study demonstrates the largest revision ACLR patient group with pre- and postoperative clinical examination data and a follow-up of 2 years published to date. Preoperative medial knee instability is an underestimated risk factor for revision ACLR failure. Additionally, high-grade anterior knee laxity, increased PTS and high BMI are risk factors for failure of revision ACLR, while additional medial stabilization and lateral extra-articular tenodesis reduce the risk of failure.

LEVEL OF EVIDENCE

III.

Modifiable factors and their association with self-reported knee function and activity after anterior cruciate ligament reconstruction: a systematic review and meta-analysis

OBJECTIVE

To determine if body mass index (BMI), smoking status, prehabilitation or time to reconstruction are associated with recovery of self-reported knee function and activity after ACL reconstruction (ACLR).

DATA SOURCES

Four electronic databases were systematically searched.

STUDY SELECTION

English language articles were included if: (1) participants aged 16-70 years had primary or first revision ACLR with autograft, following complete rupture; and (2) the association between one of four modifiable factors: (1) BMI; (2) smoking; (3) prehabilitation; or (4) time to reconstruction with self-reported knee function and activity, ACL graft rupture or return to sport was evaluated.

RESULTS

Twelve articles (representing 11 studies) were included. Meta-analyses found low-quality evidence of no difference in self-reported knee function (d = -0.07, 95% CI -0.37 to 0.23, I² = 0%) or activity levels (d = 0.11, 95% CI -0.2 to 0.41, I² = 0%) between acute and subacute ACLR. There was no difference in the relative risk of ACL graft rupture with the timing of ACLR (one study). Meta-analysis demonstrated very low-quality evidence that smokers had worse self-reported functional outcomes after ACLR compared to non-smokers (d = -0.58, 95% CI -0.788 to -0.28, I² = 59%). One study suggested an inverse relationship between BMI and knee-related quality of life after ACLR. One RCT suggested prehabilitation may reduce time to return to sport.

CONCLUSION

Low-quality evidence suggests there is no difference in delaying ACLR and very low-quality evidence suggests smokers have worse self-reported functional outcome after ACLR compared to non-smokers. High-quality RCTs are needed to confirm the relationship between the four modifiable factors studied and ACLR outcome.

Factors Associated With a Delay in Achieving Full Knee Extension Before Anterior Cruciate Ligament Reconstruction

Background:

Arthrofibrosis commonly occurs after an acute anterior cruciate ligament (ACL) injury and following ACL reconstruction and can lead to poor outcomes. Preoperative stiffness has been shown to be associated with postoperative stiffness; however, few studies have examined predictors of preoperative delay in obtaining full knee extension.

Purpose:

To examine demographic and injury factors as predictors of time required to achieve full knee extension preoperatively in patients with an acute ACL injury.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

A total of 172 patients with an acute ACL tear at presentation (defined as ≤3 weeks from injury) who underwent magnetic resonance imaging (MRI) within 6 weeks of the injury were included in this analysis. Preoperative data included date of injury, age at injury, sex, body mass index, mechanism of injury (noncontact/contact), time from injury to surgery (days), time to achieve full extension prior to surgery (weeks), and bone bruising on MRI. Time to achieve full extension was categorized as <3 or ≥3 weeks. Unadjusted and adjusted logistic regression was used to examine predictors of delayed time to achieve full extension (≥3 vs <3 weeks). Odds ratios and 95% CIs were reported.

Results:

Time to achieve full extension was early (<3 weeks) in 98 patients and delayed (≥3 weeks) in 74 patients. The average time to achieve full extension was 7 days in the early group and 32.5 days in the delayed group. Delayed time to achieve full extension was associated with increased lateral femoral condyle (LFC) bruising compared with early time to achieve extension (82.8% vs 66.7%, respectively; P = .03). No other statistically significant predictors were found after adjustment for age, sex, body mass index, and mechanism of injury.

Conclusion:

Acute ACL injuries associated with LFC bone bruising seen on MRI are more likely to result in reduced extension prior to ACL reconstruction. These injuries should be identified and addressed by an appropriate preoperative rehabilitation program, and surgery should be delayed to avoid risking arthrofibrosis postoperatively by reconstructing a knee with less than full extension.

MRI analysis of peripheral soft tissue composition, not body mass index, correlates with outcomes following anterior cruciate ligament reconstruction

PURPOSE

To utilize MRI to assess the relationship between BMI, peripheral soft tissue composition about the knee, and surgical outcomes in patients undergoing primary ACL reconstruction. It was hypothesized that a fatty periarticular soft tissue composition may be better than BMI at predicting poor outcomes after ACL reconstruction.

METHODS

Fifty-eight patients who underwent primary acute ACL reconstruction were identified from the surgical database and their data were retrospectively reviewed. Patients were selected based on availability of 2-year IKDC outcome scores, BMI data, and preoperative MRI studies. To approximate peripheral soft tissue composition, novel measurements of axial MRI images were employed using PACS ROI measurement tool. Relationships were assessed between IKDC outcome scores and measures of body habitus including BMI, total knee area, knee fatty-connective tissue area, and fatty-connective tissue to bone size ratio.

RESULTS

The median BMI was 24.3 kg/m² (range 18.5-36.9). Median IKDC score was 81.0 (range 46-100). BMI was correlated with total knee area (R = 0.72) and periarticular fat (R = 0.53). Neither continuous BMI (n.s.) nor total knee area (n.s.) was predictor of IKDC outcomes scores. Periarticular fatty-connective tissue trended towards predicting negative outcomes (n.s.). Periarticular fatty-connective tissue to bone size ratio was a significant negative predictor of IKDC scores (p = 0.03). Patients with more fat than bone on axial MRI (ratio > 1, N = 34) reported a lower mean IKDC score compared to patients with a ratio < 1 (N = 24) (77.2 vs. 87.7, p = 0.0028). The top quartile (N = 14) of these ratios reported a mean IKDC score of 68.9, compared to 87.3 of the bottom quartile (p = 0.0001).

CONCLUSIONS

Periarticular soft tissue composition, as approximated by the novel MRI analysis of this study, is a better predictor of outcomes following ACL reconstruction than is BMI. This information can be utilized in guiding surgeon and patient expectations following surgery, either via a direct application of these measurements or heightened awareness of the importance of peripheral body habitus.

LEVEL OF EVIDENCE

III.

Relationship Between Physical Activity and Clinical Outcomes After ACL Reconstruction

CONTEXT

Reductions in objectively measured moderate to vigorous physical activity (MVPA) have been reported among individuals with anterior cruciate ligament reconstruction (ACLR). Self-reported measures of physical activity are commonly used to assess participation in physical activity after ACLR despite the lack of evidence to support the validity of such measures within this population.

OBJECTIVE

The objective of this research was to determine the relationships between objectively measured MVPA, self-reported physical activity, and knee function among individuals with ACLR.

SETTING

University laboratory. Patients (or Other Participants): Thirty-one participants with a history of ACLR (sex: 23 females and 8 males; age = 19.8 [1.4] y) and 31 matched controls (sex: 23 females and 8 males; age = 20.6 [1.7] y) enrolled in this study.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURES

Participants completed self-reported physical activity using the Tegner Activity Scale and the Marx Activity Rating Scale. Participant MVPA was objectively measured using an ActiGraph wGT3X-BT accelerometer for a 7-day period during which the monitor was worn for not less than 10 hours per day. Primary outcome measures were the amount of time spent in MVPA (minutes per week) and time spent in MVPA performed in bouts of ≥10 minutes (minutes per week). Relationships between the Tegner Activity Score, Marx Activity Rating Scale, and objectively measured MVPA variables were assessed using partial Spearman's rank correlation coefficients after controlling for activity monitor wear time.

RESULTS

There were no significant relationships between objectively measured MVPA and self-reported physical activity (ρ ≤ 0.31, P ≥ .05) or self-reported knee-related function (ρ ≤ .41, P ≥ .05) among ACLR participants.

CONCLUSIONS

Objectively measured physical activity is not significantly related to self-reported physical activity or self-reported knee function among individuals with a history of ACLR. Consideration of objective and self-reported physical activity within this population may provide key insights into disconnects between perception and the reality of physical activity engagement following ACLR.

Effect of High-Grade Preoperative Knee Laxity on 6-Year Anterior Cruciate Ligament Reconstruction Outcomes

BACKGROUND

Knee laxity in the setting of anterior cruciate ligament (ACL) injury is often assessed through physical examination using the Lachman, pivot shift, and anterior drawer tests. The degree of laxity noted on these examinations may influence treatment decisions and prognosis.

HYPOTHESIS

Increased preoperative knee laxity is associated with increased risk of revision ACL reconstruction, increased risk of contralateral ACL reconstruction, and poorer patient-reported outcomes at 6 years postoperatively.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

2333 patients who underwent primary isolated ACL reconstruction without additional ligament injury were identified. Patients reported by the operating surgeons to have an International Knee Documentation Committee (IKDC) grade D Lachman, anterior drawer, or pivot shift examination were classified as having a high-grade laxity. Multiple logistic regression models were used to evaluate whether having high-grade preoperative laxity was predictive of increased odds of undergoing subsequent revision or contralateral ACL reconstruction within 6 years of the index procedure, controlling for patient age, sex, body mass index, Marx activity level, sport, graft type, medial meniscal treatment, and lateral meniscal treatment. Multiple linear regression modeling was used to evaluate whether having high-grade preoperative laxity was predictive of poorer IKDC or Knee injury and Osteoarthritis Outcome Score Knee-Related Quality of Life (KOOS-QOL) scores at 6 years postoperatively, after controlling for baseline score, patient age, ethnicity, sex, body mass index, marital status, smoking status, sport participation, competition level, Marx activity rating score, graft type, and articular cartilage and meniscal status.

RESULTS

In total, 743 of 2325 patients (32.0%) were noted to have high-grade laxity on at least 1 physical examination test. High-grade Lachman was noted in 334 patients (14.4%), high-grade pivot shift was noted in 617 patients (26.5%), and high-grade anterior drawer was noted in 233 patients (10.0%). Six-year revision and contralateral ACL reconstruction data were available for 2129 patients (91.6%). High-grade prereconstruction Lachman was associated with significantly increased odds of ACL graft revision (odds ratio [OR], 1.76; 95% CI, 1.10-2.80, P = .02) and contralateral ACL reconstruction (OR, 1.68; 95% CI, 1.09-2.69; P = .019). High-grade prereconstruction pivot shift was associated with significantly increased odds of ACL graft revision (OR, 1.75; 95% CI, 1.19-2.54, P = .002) but not with significantly increased odds of contralateral ACL reconstruction (OR, 1.30; 95% CI, 0.89-1.87; P = .16). High-grade prereconstruction laxity was associated with statistically significantly lower 6-year IKDC (β = -2.26, P = .003), KOOS-QOL (β = -2.67, P = .015), and Marx activity scores (β = -0.54, P = .020), but these differences did not approach clinically relevant differences in patient-reported outcomes.

CONCLUSION

High-grade preoperative knee laxity is predictive of increased odds of revision ACL reconstruction and contralateral ACL reconstruction 6 years after ACL reconstruction. Poorer patient-reported outcome scores in the high-grade laxity group were also noted, but the difference did not reach a level of clinical relevance.

Two-Plane Assessment of Knee Muscles Isometric and Isokinetic Torques After Anterior Cruciate Ligament Reconstruction

Background

We tested the hypothesis that, in patients participating in 17 weeks of postoperative physiotherapy after anterior cruciate ligament reconstruction (ACLR), maximal isometric torque (IT) and peak torque (PT) generated by the muscles affecting the operated knee joint in the sagittal and transverse planes are not restored. We also present the application of IT and PT measurements of the muscles affecting the knee joint in 2 planes of motion.

Material/Methods

IT and PT of the knee extensor and flexor muscles and the muscles internally rotating the shin were measured in 30 males who participated in postoperative physiotherapy for 17 weeks after ACLR (ACLR group) and 30 males with no injuries (control group).

Results

Significantly lower IT and PT values were noted in the operated knee extensors and flexors. The differences were also noted in the PT for the muscles internally rotating the shin and in the IT of those muscles in the position of 25° of internal rotation. Significantly lower relative IT and PT values were noted for studied muscle groups in comparison to the control group.

Conclusions

Seventeen weeks of postoperative physiotherapy after ACLR did not result in complete restoration of IT and PT of the muscles affecting the operated knee joint, suggesting that even after 17 weeks of physiotherapy following ACLR, athletes may not be ready to return to sports. The results demonstrate the usefulness of biplanar analysis of muscle strength under isometric and isokinetic conditions in the monitoring and assessment of physiotherapeutic procedures.

Weak associations between body mass index and self-reported disability in people with unilateral anterior cruciate ligament reconstruction

PURPOSE AND HYPOTHESIS

Individuals with an anterior cruciate ligament reconstruction (ACLR) are susceptible to persistent disability, weight gain and the development of knee osteoarthritis. It remains unclear whether body mass index (BMI) is a factor that influences disability following ACLR. The purpose of this study was to determine the association between BMI and self-reported disability [International Knee Documentation Committee (IKDC) Index] in individuals with a unilateral ACLR. We hypothesized that lower BMI would associate with higher IKDC.

METHODS

BMI and IKDC were measured in 668 individuals with a unilateral ACLR (60.9% female, BMI 24.4 ± 3.7 kg/m², IKDC 84.7 ± 11.9%). Bivariate associations were conducted between BMI and IKDC for the entire sample and selected subsets (gender, ACLR graft type and history of meniscal injury). Multiple regression analyses were used to determine the impact of potential covariates (Tegner score, age and months since ACLR) for significant bivariate associations. After accounting for covariates, there were no significant associations between BMI and IKDC when separately evaluating the cohort based on either gender or history of a concomitant meniscal injury. The odds of achieving age- and gender-matched healthy population average IKDC scores for those with low (<25) and high (≥25) BMI were determined.

RESULTS

Lower BMI associated with higher IKDC (r = -0.08, P = 0.04). For the entire sample, BMI did not uniquely predict variance in IKDC (ΔR ² > 0.001, n.s.) after accounting for covariates. BMI uniquely predicted a significant but negligible amount of variance in IKDC in individuals with a patellar tendon autograft (ΔR ² = 0.015, n.s.). Individuals with low BMI demonstrated higher odds (odds ratio = 1.45; 1.05-1.99) of achieving population average IKDC scores compared to participants with high BMI.

CONCLUSIONS

There was a significant but negligible correlation between lower BMI and lesser disability in individuals with unilateral ACLR and individuals who are underweight or of normal BMI demonstrated higher odds of achieving population average IKDC scores compared to overweight or obese individuals. While an overall association was found between lower BMI and lesser disability, the magnitude of the association remains negligible; therefore, BMI was not a strong clinical predictor of successful ACLR outcomes in this cohort of patients with unilateral ACLR.

LEVEL OF EVIDENCE

Cross-sectional prognostic study, Level II.

Higher hamstring-to-quadriceps isokinetic strength ratio during the first post-operative months in patients with quadriceps tendon compared to hamstring tendon graft following ACL reconstruction

PURPOSE

The aim of this study was to compare isokinetic quadriceps and hamstring muscle strength in patients following anterior cruciate ligament (ACL) reconstruction who received either hamstring (HT) or quadriceps (QT) tendon autografts at two time intervals within the first year after surgery.

METHODS

One hundred twenty-four patients, 81 males (age 22.0 ± 6.2 years) and 43 females (age 20.9 ± 8.7 years), participated in this study. ACL reconstruction was performed with either quadriceps tendon autografts (QT; n = 61) or hamstring tendon autografts (HT; n = 63). Two isokinetic muscle strength tests (t1: 5.5 ± 1.2 months; t2: 7.6 ± 1.6 months) were performed at an angular velocity of 60°/s in both the injured and contralateral knees. An independent t test as well as a two-factor analysis of variance with repeated measurements was used. The significance level was set at p < 0.05.

RESULTS

A statistically significant lower knee extensor strength was observed in the QT group within one year after surgery (p < 0.001). Additionally, data showed a significant higher H/Q ratio in QT patients compared to the HT group at t1 (p < 0.001) and t2 (p = 0.001) as well as a significant effect over time (p < 0.001) and interaction effect of time and graft (p = 0.007). Side-to-side values for extensor muscle strength were significantly (p < 0.001) greater in HT graft patients, while QT patients showed significantly (p < 0.001) greater values for flexor muscle strength at both time points of isokinetic testing, respectively.

CONCLUSION

The results of this study indicate that graft choice has an impact on extensor strength in the first months after ACL reconstruction; however, there is no impact on flexor strength. The finding of a higher H/Q ratio in patients with QT grafts within the first months following surgery is possibly of clinical relevance. This may potentially be associated with lower stress on the maturing ACL graft. Furthermore, normal thigh strength can be restored over time.

LEVEL OF EVIDENCE

III.

Isokinetic Extension Strength Is Associated With Single-Leg Vertical Jump Height

Background

Isokinetic strength testing is an important tool in the evaluation of the physical capacities of athletes as well as for decision making regarding return to sports after anterior cruciate ligament (ACL) reconstruction in both athletes and the lay population. However, isokinetic testing is time consuming and requires special testing equipment.

Hypothesis

A single-jump test, regardless of leg dominance, may provide information regarding knee extension strength through the use of correlation analysis of jump height and peak torque of isokinetic muscle strength.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

A total of 169 patients who underwent ACL reconstruction were included in this study. Isokinetic testing was performed on the injured and noninjured legs. Additionally, a single-leg countermovement jump was performed to assess jump height using a jump accelerometer sensor. Extension strength values were used to assess the association between isokinetic muscle strength and jump height.

Results

The sample consisted of 60 female (mean age, 20.8 ± 8.3 years; mean weight, 61.7 ± 6.5 kg; mean height, 167.7 ± 5.3 cm) and 109 male (mean age, 23.2 ± 7.7 years; mean weight, 74.6 ± 10.2 kg; mean height, 179.9 ± 6.9 cm) patients. Bivariate correlation analysis showed an association (r = 0.56, P < .001) between jump height and isokinetic extension strength on the noninvolved side as well as an association (r = 0.52, P < .001) for the involved side. Regression analysis showed that in addition to jump height (beta = 0.49, P < .001), sex (beta = -0.17, P = .008) and body mass index (beta = 0.37, P < .001) affected isokinetic strength. The final model explained 51.1% of the variance in isokinetic muscle strength, with jump height having the strongest impact (beta = 0.49, P < .001) and explaining 31.5% of the variance.

Conclusion

Initial analysis showed a strong association between isokinetic strength and jump height. The study population encompassed various backgrounds, skill levels, and activity profiles, which might have affected the outcome. Even after controlling for age and sex, isokinetic strength was still moderately associated with jump height. Therefore, the jump technique and type of sport should be considered in future research.

Posttraumatic Bone Marrow Lesion Volume and Knee Pain Within 4 Weeks After Anterior Cruciate Ligament Injury

CONTEXT

  After an anterior cruciate ligament (ACL) injury, a majority of patients have a traumatic bone marrow lesion (BML, or bone bruise). The clinical relevance of posttraumatic lesions remains unclear.

OBJECTIVE

  To explore the cross-sectional associations between traumatic BML volume and self-reported knee pain and symptoms among individuals within 4 weeks of ACL injury.

DESIGN

  Cross-sectional exploratory analysis of a randomized clinical trial.

SETTING

  Orthopaedic departments at 2 hospitals in Sweden.

PATIENTS OR OTHER PARTICIPANTS

  As part of a randomized trial (knee anterior cruciate ligament nonoperative versus operative treatment [KANON] study), 121 young active adults (74% men, age = 26 ± 5 years, height = 1.8 ± 0.1 m, weight = 76 ± 13 kg) with an ACL tear were studied.

MAIN OUTCOME MEASURE(S)

  The BML volume in the proximal tibia and distal femur was segmented using magnetic resonance images obtained within 4 weeks of injury. A radiologist evaluated the presence of depression fractures on the images. Pain and symptoms of the injured knee (Knee Injury and Osteoarthritis Outcome Score [KOOS] pain and symptoms subscales) were obtained the same day as imaging. We used linear regression models to assess the associations.

RESULTS

  Most knees had at least 1 BML (96%), and the majority (57%) had a depression fracture. Whole-knee BML volume was not related to knee pain for the entire cohort (β = -0.09, P = .25). Among those without a depression fracture, larger whole-knee BML volume was associated with increased knee pain (β = -0.46, P = .02), whereas no association was found for those with a depression fracture (β = 0.0, P = .96). Larger medial (β = -0.48, P = .02) but not lateral (β = -0.03, P = .77) tibiofemoral BML volume was associated with greater pain. We found no association between BML volume and knee symptoms.

CONCLUSIONS

  We confirmed the absence of relationships between whole-knee BML volume and pain and symptoms within 4 weeks of ACL injury. Our findings extend previous reports in identifying weak associations between larger BML volume in the medial compartment and greater pain and between BML volume and greater pain among those without a depression fracture.

Return to knee-strenuous sport after anterior cruciate ligament reconstruction: a report from a rehabilitation outcome registry of patient characteristics

PURPOSE

To characterise patients who returned to knee-strenuous sports after an anterior cruciate ligament (ACL) reconstruction.

METHODS

Data from isotonic tests of muscle function and patient-reported outcome measures, Tegner activity scale (Tegner and Lysholm in Clin Orthop Relat Res 198:43-49, 1985), physical activity scale, knee injury and osteoarthritis scale and knee self-efficacy scale were extracted from a registry. The 157 included patients, 15-30 years of age, had undergone primary ACL reconstruction and were all involved in knee-strenuous sports, i.e. pre-injury Tegner of 6 or higher. Return to sport was studied in two different ways: return to pre-injury Tegner and return to knee-strenuous sport (Tegner 6).

RESULTS

Fifty-two patients (33 %), who returned to pre-injury Tegner, 10 months after surgery, were characterised by better subjective knee function measured with the knee injury and osteoarthritis outcome score (p < 0.05), compared with patients who did not. These patients also had higher perceived self-efficacy of knee function (p < 0.01), measured with knee self-efficacy scale. Eighty-four patients (54 %) who returned to knee-strenuous sports, i.e. Tegner 6 or higher, were characterised by higher goals for physical activity (p < 0.01) and higher self-efficacy of future knee function (p < 0.05). Strength measurements showed that women who returned to sports were stronger in leg extension than women who did not. No differences were found in Limb Symmetry Index for knee strength or jumping ability.

CONCLUSION

Patients who returned to sports after ACL reconstruction had better subjective knee function and higher self-efficacy of knee function. Results highlight that further emphasis should be placed at psychological factors during rehabilitation of patients after ACLR.

LEVEL OF EVIDENCE

II.

Effect of High-Grade Preoperative Knee Laxity on Anterior Cruciate Ligament Reconstruction Outcomes

BACKGROUND

Knee laxity in the setting of suspected anterior cruciate ligament (ACL) injury is frequently assessed through physical examination using the Lachman, pivot-shift, and anterior drawer tests. The degree of laxity noted on these examinations may influence treatment decisions and prognosis.

HYPOTHESIS

Increased preoperative knee laxity would be associated with increased risk of subsequent revision ACL reconstruction and worse patient-reported outcomes 2 years postoperatively.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

From an ongoing prospective cohort study, 2333 patients who underwent primary isolated ACL reconstruction without collateral or posterior cruciate ligament injury were identified. Patients reported by the operating surgeons as having an International Knee Documentation Committee (IKDC) grade D for Lachman, anterior drawer, or pivot-shift examination were classified as having high-grade laxity. Multiple logistic regression modeling was used to evaluate whether having high-grade preoperative laxity was associated with increased odds of undergoing revision ACL reconstruction within 2 years of the index procedure, controlling for patient age, sex, Marx activity level, level of competition, and graft type. Multiple linear regression modeling was used to evaluate whether having high-grade preoperative laxity was associated with worse IKDC score or Knee injury and Osteoarthritis Outcome Score Knee-Related Quality of Life subscale (KOOS-QOL) scores at a minimum 2 years postoperatively, controlling for baseline score, patient age, ethnicity, sex, body mass index, marital status, smoking status, sport participation, competition level, Marx activity rating score, graft type, and articular cartilage and meniscus status.

RESULTS

Pre-reconstruction laxity data were available for 2325 patients (99.7%). Two-year revision data were available for 2259 patients (96.8%), and patient-reported outcomes were available for 1979 patients (84.8%). High-grade preoperative laxity was noted in 743 patients (31.9%). The mean postoperative IKDC score was 81.8 ± 15.9, and the mean KOOS-QOL score was 72.0 ± 22.0. The presence of high-grade pre-reconstruction laxity was associated with significantly increased odds of ACL graft revision (odds ratio [OR] = 1.87 [95% CI, 1.19-2.95]; P = .007). The presence of high-grade pre-reconstruction laxity was not associated with any difference in postoperative IKDC (β = -0.56, P = .44) or KOOS-QOL (β = 0.04, P = .97).

CONCLUSION

The presence of high-grade pre-reconstruction knee laxity as assessed by manual physical examination under anesthesia is associated with significantly increased odds of revision ACL surgery but has no association with patient-reported outcome scores at 2 years after ACL reconstruction.

An Ecological Study of Anterior Cruciate Ligament Reconstruction, Part 1: Clinical Tests Do Not Correlate With Return-to-Sport Outcomes

BACKGROUND

Additional high-quality prospective studies are needed to better define the objective criteria used in relation to return-to-sport decisions after synthetic (ligament advanced reinforcement system [LARS]) and autograft (hamstring tendon [2ST/2GR]) anterior cruciate ligament (ACL) reconstruction in active populations.

PURPOSE

To prospectively investigate and describe the recovery of objective clinical outcomes after autograft (2ST/2GR) and synthetic (LARS) ACL reconstructions, as well as to investigate the relationship between these clinimetric test outcomes and return-to-sport activity (Tegner activity scale [TAS] score) at 12 and 24 months postoperatively.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 64 patients who underwent ACL reconstruction (32 LARS, 32 2ST/2GR autograft) and 32 healthy reference participants were assessed for joint laxity (KT-1000 arthrometer), clinical outcome (2000 International Knee Documentation Committee [IKDC] knee examination), and activity (TAS score) preoperatively and at 12, 16, 20, and 24 weeks and 12 and 24 months postoperatively.

RESULTS

There was no significant correlation observed between clinical results using the 2000 IKDC knee examination and TAS score at 24 months (r_s = 0.188, P = .137), nor were results for side-to-side difference (r_s = 0.030, P = .814) or absolute KT-1000 arthrometer laxity of the surgical leg at 24 months postoperatively (r_s = 0.076, P = .553) correlated with return-to-sport activity. Nonetheless, return-to-sport rates within the surgical cohort were 81% at 12 months and 83% at 24 months, respectively. No statistically significant differences were observed between physiological laxity of the uninjured knee within the surgical group compared with healthy knees within the reference group (P = .522).

CONCLUSION

The results indicate that although relatively high levels of return-to-sport outcomes were achieved at 24 months compared with those previously reported in the literature, correlations between objective clinical tests and return-to-sport outcomes may not occur. Clinical outcome measures may provide suitable baseline information; however, the results of this study suggest that clinicians may need to place greater emphasis on other outcome measures when seeking to objectively promote safe return to sport.

Evidence-based clinical practice update: practice guidelines for anterior cruciate ligament rehabilitation based on a systematic review and multidisciplinary consensus

AIM

The Royal Dutch Society for Physical Therapy (KNGF) instructed a multidisciplinary group of Dutch anterior cruciate ligament (ACL) experts to develop an evidence statement for rehabilitation after ACL reconstruction.

DESIGN

Clinical practice guideline underpinned by systematic review and expert consensus.

DATA SOURCES

A multidisciplinary working group and steering group systematically reviewed the literature and wrote the guideline. MEDLINE and the Cochrane Library were searched for meta-analyses, systematic reviews, randomised controlled trials and prospective cohort studies published between January 1990 and June 2015.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Included literature must have addressed 1 of 9 predetermined clinical topics: (1) preoperative predictors for postoperative outcome, (2) effectiveness of physical therapy, (3) open and closed kinetic chain quadriceps exercises, (4) strength and neuromuscular training, (5) electrostimulation and electromyographic feedback, (6) cryotherapy, (7) measurements of functional performance, (8) return to play and (9) risk for reinjury.

SUMMARY

Ninety studies were included as the basis for the evidence statement. Rehabilitation after ACL injury should include a prehabilitation phase and 3 criterion-based postoperative phases: (1) impairment-based, (2) sport-specific training and (3) return to play. A battery of strength and hop tests, quality of movement and psychological tests should be used to guide progression from one rehabilitation stage to the next. Postoperative rehabilitation should continue for 9-12 months. To assess readiness to return to play and the risk for reinjury, a test battery, including strength tests, hop tests and measurement of movement quality, should be used.

Factors Associated With High-Grade Lachman, Pivot Shift, and Anterior Drawer at the Time of Anterior Cruciate Ligament Reconstruction

PURPOSE

To determine which patient and injury factors are associated with the detection of high-grade laxity on examination under anesthesia before anterior cruciate ligament (ACL) reconstruction.

METHODS

We identified 2,318 patients who underwent primary ACL reconstruction without associated ligament injuries. Demographic data and information regarding meniscal tears were collected. Patients with high-grade Lachman (difference from contralateral side >10 mm), pivot-shift (International Knee Documentation Committee grade 3+), or anterior drawer (difference from contralateral side >10 mm) tests were identified by physical examination under anesthesia before ACL reconstruction. Logistic regression modeling was used to evaluate whether chronicity of the ACL injury, patient age, sex, body mass index, generalized ligamentous laxity, and presence of meniscal tears were associated with increased odds of high-grade laxity, while we controlled for examining surgeon.

RESULTS

Patients with chronic tears (>6 months from injury) had greater than twice the odds of having high-grade Lachman, pivot-shift, and anterior drawer tests (all P < .001) relative to patients with acute tears (<3 months from injury). Generalized ligamentous laxity (odds ratio [OR], 2.33; P < .001) and the presence of medial (OR, 1.63; P < .001) or lateral (OR, 1.41; P = .013) meniscus tears were associated with increased odds of a high-grade Lachman test. Age younger than 20 years (OR, 1.34; P = .023), female sex (OR, 1.49; P = .001), generalized ligamentous laxity (OR, 3.46; P < .001), and the presence of a medial (OR, 1.53; P < .001) or lateral (OR, 1.27; P = .041) meniscus tear were associated with increased odds of a high-grade pivot-shift test. Generalized ligamentous laxity (OR, 2.27; P < .001) and the presence of a medial (OR, 1.73; P = .001) or lateral (OR, 1.50; P = .010) meniscus tear were associated with increased odds of a high-grade anterior drawer test.

CONCLUSIONS

Chronic ACL tears, generalized ligamentous laxity, and meniscus tears are associated with increased odds of high-grade laxity with all 3 tests. Female patients and age younger than 20 years are associated with increased odds of a high-grade pivot-shift test.

LEVEL OF EVIDENCE

Level II, lesser-quality prospective study.

Factors associated with a more rapid recovery after anterior cruciate ligament reconstruction using multivariate analysis

BACKGROUND

In the past, several studies investigated factors that are prognostic or associated with outcome after anterior cruciate ligament (ACL) reconstruction. A recent review showed that only limited evidence is available for most studied factors, and that insufficient analysis methods were used commonly. Therefore, the aim of this study was to add more weight to the existing evidence, about factors that are associated with a more rapid outcome after ACL reconstruction. The second aim was to use multivariate analysis to study the possible factors independently.

METHODS

A cohort study was conducted with a follow-up of six months. Before surgery, patient variables were scored. Surgical variables were scored during arthroscopic ACL reconstructions with a single-bundle technique and hamstring autograft. The Lysholm score and subscales of the Knee Injury Osteoarthritis Outcome Score (KOOS) were assessed six months post surgery. A multiple analysis of variance (ANOVA) model was used to identify prognostic factors for outcome.

RESULTS

In total, 118 patients were included. Patients, aged ≤30years, with a subjective knee score ≥ six, with normal flexion range of motion (ROM) of the knee, with flexion and extension strength deficit of ≤20%, and those with no previous knee surgery in the same knee at baseline scored significantly higher on outcome after multivariate analysis. No significant effect of surgical factors could be found.

CONCLUSION

Younger age, higher subjective knee score, normal knee flexion, normal knee flexion and extension strength, and no previous knee surgery in the patients' history at baseline are associated with a more rapid recovery after ACL reconstruction.

LEVEL OF EVIDENCE

Level III, prognostic study.

One-leg hop kinematics 20 years following anterior cruciate ligament rupture: Data revisited using functional data analysis

BACKGROUND

Despite interventions, anterior cruciate ligament ruptures can cause long-term deficits. To assist in identifying and treating deficiencies, 3D-motion analysis is used for objectivizing data. Conventional statistics are commonly employed to analyze kinematics, reducing continuous data series to discrete variables. Conversely, functional data analysis considers the entire data series.

METHODS

Here, we employ functional data analysis to examine and compare the entire time-domain of knee-kinematic curves from one-leg hops between and within three groups. All subjects (n=95) were part of a long-term follow-up study involving anterior cruciate ligament ruptures treated ~20 years ago conservatively with physiotherapy only or with reconstructive surgery and physiotherapy, and matched knee-healthy controls.

FINDINGS

Between-group differences (injured leg, treated groups; non-dominant leg, controls) were identified during the take-off and landing phases, and in the sagittal (flexion/extension) rather than coronal (abduction/adduction) and transverse (internal/external) planes. Overall, surgical and control groups demonstrated comparable knee-kinematic curves. However, compared to controls, the physiotherapy-only group exhibited less flexion during the take-off (0-55% of the normalized phase) and landing (44-73%) phase. Between-leg differences were absent in controls and the surgically treated group, but observed during the flight (4-22%, injured leg>flexion) and the landing (57-85%, injured leg<internal rotation) phases in the physiotherapy-only group.

INTERPRETATION

Functional data analysis identified specific functional knee-joint deviations from controls persisting 20 years post anterior cruciate ligament rupture, especially when treated conservatively. This approach is suggested as a means for comprehensively analyzing complex movements, adding to previous analyses.

Does obesity affect outcomes in hip arthroscopy? A matched-pair controlled study with minimum 2-year follow-up

BACKGROUND

Hip arthroscopy has gained popularity over the past decade, and its indications have broadened as newer techniques have been developed. However, there has been a paucity of literature evaluating the outcomes of hip arthroscopy in obese patients.

PURPOSE

To compare 2-year clinical outcomes of obese patients undergoing primary hip arthroscopy with matched nonobese controls.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

From February 2008 to February 2012, data were collected prospectively on all obese patients undergoing primary hip arthroscopy. A matched-pair nonobese control group was selected at a 1:2 ratio. All patients were assessed pre- and postoperatively with 4 patient-reported outcome (PRO) measures: the modified Harris Hip Score, Non-Arthritic Hip Score, Hip Outcome Score-Activities of Daily Living, and Hip Outcome Score-Sport Specific Subscale. Pain was estimated on the visual analog scale, and satisfaction was measured on a scale from 0 to 10.

RESULTS

Sixty-two hips (62 patients) were included in the obese group and 124 hips (124 patients) in the control group. At preoperative baseline, the obese group had significantly lower PRO scores when compared with the control group. Both groups demonstrated statistically significant postoperative improvement in all scores (P < .05). Absolute scores were significantly lower in the obese group for all PRO measures, pre- and postoperatively. However, the improvement (delta) in PRO scores from pre- to postoperative time was not significantly different between groups. The rate of conversion to total hip arthroplasty, the rate of revision, and the complication rate were not significantly different between the 2 groups; however, rates of conversion to total hip arthroplasty and revision tended to be twice as high in the obese patients, but the study was not powered for these 2 outcomes.

CONCLUSION

Overall, obese patients had lower absolute PRO scores preoperatively and at 2-year follow-up. Both obese and nonobese patients demonstrated significant improvement in all PRO scores, and the change in scores were similar between groups. These results indicate that while obese patients may not have similar absolute scores after hip arthroscopy, they may show similar gains in improvement when compared with baseline. Hip arthroscopy appears to be a viable treatment option in the obese patient as long as expectations are adjusted accordingly.

Factors associated with excellent 6-month functional and isokinetic test results following ACL reconstruction

PURPOSE

To identify patient concomitant injury and surgical characteristics associated with 6-month excellent functional and isokinetic testing results following anterior cruciate ligament (ACL) reconstruction.

METHODS

Patients that underwent ACL reconstruction by a single surgeon had isokinetic and functional testing performed with excellent 6-month outcome defined as greater than 85 % in isokinetic strength and 90 % in functional tests (excellent 6-month group vs. delayed 6-month group). Patient concomitant injury and surgical factors were then analysed in univariate and multivariate statistical models to assess which characteristics predicted the excellent 6-month group.

RESULTS

The 224 patients included 93 males and 131 females, with median age of 22 (range 12-59) years, body mass index (BMI) of 25.4 (range 17-44), and median Tegner activity score of 6 (range 2-10). Fifty-two patients (23 %) were included in the excellent 6-month group, while 172 patients (77 %) were in the delayed 6-month group. In univariate analysis, favourable factors with the excellent 6-month outcome group were younger age (24 vs. 27; p = 0.01), lower BMI (24.5 vs. 26.2; p = 0.03), and minimal articular cartilage damage (71 vs. 56 %; p = 0.048). In multivariate analysis, a negative effect was observed for patients older than 30 years that had ACL reconstruction with autograft (p = 0.0004).

CONCLUSION

Factors significantly associated with excellent 6-month functional and isokinetic test results following ACL reconstruction included younger age, lower BMI, and minimal cartilage degeneration. The use of allograft was associated with improved functional and strength testing after ACL reconstruction in patients over 30 years of age.

LEVEL OF EVIDENCE

Prognostic/therapeutic study, Level III.

Psychological predictors of anterior cruciate ligament reconstruction outcomes: a systematic review

PURPOSE

Lack of return to sport following anterior cruciate ligament (ACL) reconstruction often occurs despite adequate restoration of knee function, and there is growing evidence that psychological difference among patients may play an important role in this discrepancy. The purpose of this review is to identify baseline psychological factors that are predictive of clinically relevant ACL reconstruction outcomes, including return to sport, rehab compliance, knee pain, and knee function.

METHODS

A systematic search was performed in PubMed, Google Scholar, CINAHL, UptoDate, Cochrane Reviews, and SportDiscus, which identified 1,633 studies for potential inclusion. Inclusion criteria included (1) prospective design, (2) participants underwent ACL reconstruction, (3) psychological traits assessed at baseline, and (4) outcome measures such as return to sport, rehabilitation compliance, and knee symptoms assessed. Methodological quality was evaluated with a modified Coleman score with several item-specific revisions to improve relevance to injury risk assessment studies in sports medicine.

RESULTS

Eight prospective studies were included (modified Coleman score 63 ± 4.9/90, range 55-72). Average study size was 83 ± 42 patients with median 9-month follow-up (range 3-60 months). Measures of self-efficacy, self-motivation, and optimism were predictive of rehabilitation compliance, return to sport, and self-rated knee symptoms. Pre-operative stress was negatively predictive, and measures of social support were positively predictive of knee symptoms and rehabilitation compliance. Kinesiophobia and pain catastrophizing at the first rehabilitation appointment did not predict knee symptoms throughout the early rehabilitation phase (n.s.).

CONCLUSIONS

Patient psychological factors are predictive of ACL reconstruction outcomes. Self-confidence, optimism, and self-motivation are predictive of outcomes, which is consistent with the theory of self-efficacy. Stress, social support, and athletic self-identity are predictive of outcomes, which is consistent with the global relationship between stress, health, and the buffering hypothesis of social support.

Does obesity affect outcomes after hip arthroscopy? A cohort analysis

BACKGROUND

Obesity presents a challenging problem in surgical treatment and has led to poorer postoperative outcomes. The purpose of this study was to evaluate whether hip arthroscopy in the obese patient influences postoperative clinical and patient-reported outcome scores.

METHODS

From February 2008 to February 2012, data were collected prospectively on all patients undergoing primary hip arthroscopy. A total of 680 patients were included. All patients were assessed preoperatively and postoperatively with four patient-reported outcome measures. Pain was estimated on the visual analog scale. The patient satisfaction score was measured. Three groups were stratified by body mass index. The non-obese group, those with a body mass index of <30 kg/m(2) (mean, 23.61 kg/m(2)), included 562 patients with a mean age of 34.78 years. The class-I obese group, those with a body mass index of ≥30 to 34.9 kg/m(2) (mean, 33.85 kg/m(2)), included ninety-four patients with a mean age of 44.02 years. The class-II obese group, those with a body mass index of ≥35 to 39.9 kg/m(2) (mean, 39.11 kg/m(2)), included twenty-four patients with a mean age of 39.33 years.

RESULTS

In the non-obese group, the score improvement from the preoperative assessment to the two-year follow-up visit was 63.41 to 83.81 points for the modified Harris hip score, 60.86 to 83.62 points for the Non-Arthritic Hip Score, 66.24 to 86.24 points for the Hip Outcome Score Activities of Daily Living, and 44.01 to 73.26 points for the Hip Outcome Score Sport-Specific Subscale. In the class-I obese group, the score improvement from the preoperative assessment to the two-year follow-up visit was 54.81 to 75.95 points for the modified Harris hip score, 48.98 to 72.51 points for the Non-Arthritic Hip Score, 53.22 to 72.99 points for the Hip Outcome Score Activities of Daily Living, and 30.56 to 60.75 points for the Hip Outcome Score Sport-Specific Subscale. In the class-II obese group, the score improvement from the preoperative assessment to the two-year follow-up visit was 50.81 to 80.01 points for the modified Harris hip score, 42.36 to 72.50 points for the Non-Arthritic Hip Score, 48.11 to 74.73 points for the Hip Outcome Score Activities of Daily Living, and 28.25 to 62.56 points for the Hip Outcome Score Sport-Specific Subscale. Traction time did not vary significantly between groups (p < 0.05).

CONCLUSIONS

Our study demonstrated that obese patients started with lower absolute scores preoperatively and ended with lower overall absolute postoperative scores. However, obese patients showed substantial benefit from hip arthroscopy and demonstrated a degree of improvement that was similar to that of the control non-obese group.

Does body mass index affect outcomes of ambulatory knee and shoulder surgery?

PURPOSE

Obesity is highly prevalent among patients with knee and shoulder injuries and is associated with greater odds of surgical treatment for these injuries. The purpose of this systematic review was to summarize the literature that has examined the association between body mass index (BMI) and outcomes of ambulatory knee and shoulder surgery.

METHODS

A literature search of PubMed and Medline was conducted up to December 2013. Studies that examined the association between BMI and outcomes after ambulatory knee and shoulder surgery (arthroscopy, repairs, and reconstructions) were included. Outcomes included postoperative functional scores, clinical scores, and complications.

RESULTS

Eighteen studies were included in this review; 13 involved knee surgery and 5 involved shoulder surgery. Seven knee studies and 2 shoulder studies found increased BMI to be associated with worse postoperative outcomes, whereas the remaining 9 studies did not find an association. Increased BMI was associated with worse clinical scores and less patient satisfaction after arthroscopic meniscectomy or debridement, and with worse clinical scores and lower activity levels after anterior cruciate ligament (ACL) reconstruction. It was also associated with worse clinical scores and a longer hospital stay after rotator cuff repair and with longer time to return to work after subacromial decompression. Six studies examined the association between BMI and complications, but all reported null findings.

CONCLUSIONS

There is a lack of consensus in the literature regarding the association between BMI and ambulatory knee and shoulder surgery. Several factors may have contributed to contradictory findings, including variation in measuring and classifying anthropometry, postoperative outcomes, and follow-up time.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I, III, and IV studies.

Preoperative patient and injury factors of successful rehabilitation after anterior cruciate ligament reconstruction with single-bundle techniques

PURPOSE

The aim of this systematic review was to determine which patient determinants and injury factors, before anterior cruciate ligament reconstruction by arthroscopic single-bundle techniques, affect postoperative rehabilitation.

METHODS

A search of PubMed, Embase, and the Cochrane Database of Clinical Trials was performed up to February 2013. After application of our inclusion criteria, a final selection was made based on studies' methodologic score assessed with the Newcastle-Ottawa Scale. Meta-analysis was planned for each prognostic factor when data were considered clinically and statistically homogeneous.

RESULTS

Meta-analysis showed that male patients have better functional outcomes. Qualitative synthesis from 18 high-quality studies showed that patients operated on before 30 years of age reach higher activity levels. Patients with high baseline body mass index have lower activity levels after surgery. Smoking results in more symptoms and lower activity levels and subjective scores. Reconstruction before 3 months results in higher activity levels. Preoperatively, a less than 20% quadriceps strength difference, 50° of tibial external rotation or less, absence of flexion deficits, low knee influence on the patient's activity level, and less anterior knee pain result in higher functional scores. Preoperative anterior laxity difference does not predict functional scores. The prognostic value of preoperative activity and competition level for postoperative functional outcome is controversial. Patients with concomitant meniscal injuries have worse functional outcomes. The prognostic value of concomitant chondral pathology for postoperative functional outcome is controversial. Collateral ligament injury could predict functional scores or activity level.

CONCLUSIONS

Male gender, patient age younger than 30 years, reconstruction before 3 months, and high baseline activity level contribute to better functional outcomes. Smoking, high body mass index, quadriceps strength, and range-of-motion deficits affect rehabilitation negatively. Preoperative anterior laxity does not influence rehabilitation. The role of preoperative prognostic injury factors remains unclear because of limited evidence.

LEVEL OF EVIDENCE

Level III, systematic review of Level II and III studies.

Variables associated with return to sport following anterior cruciate ligament reconstruction: a systematic review

BACKGROUND

As one of the purposes of anterior cruciate ligament reconstruction (ACLR) is to return athletes to their preinjury activity level, it is critical to understand variables influencing return to sport. Associations between return to sport and variables representing knee impairment, function and psychological status have not been well studied in athletes following ACLR.

PURPOSE

The purpose of this review was to summarise the literature reporting on variables proposed to be associated with return to sport following ACLR.

STUDY DESIGN

Systematic review.

METHODS

Medline, EMBASE, CINAHL and Cochrane databases were searched for articles published before November 2012. Articles included in this review met these criteria: (1) included patients with primary ACLR, (2) reported at least one knee impairment, function or psychological measure, (3) reported a return to sport measure and (4) analysed the relationship between the measure and return to sport.

RESULTS

Weak evidence existed in 16 articles suggesting variables associated with return to sport included higher quadriceps strength, less effusion, less pain, greater tibial rotation, higher Marx Activity score, higher athletic confidence, higher preoperative knee self-efficacy, lower kinesiophobia and higher preoperative self-motivation.

CONCLUSIONS

Weak evidence supports an association between knee impairment, functional and psychological variables and return to sport. Current return to sport guidelines should be updated to reflect all variables associated with return to sport. Utilising evidence-based return to sport guidelines following ACLR may ensure that athletes are physically and psychologically capable of sports participation, which may reduce reinjury rates and the need for subsequent surgery.

Pre-operative quadriceps strength predicts IKDC2000 scores 6 months after anterior cruciate ligament reconstruction

BACKGROUND

Quadriceps strength deficits are ubiquitous after anterior cruciate ligament (ACL) injury. Deficits prior to surgery can influence knee function post-operatively. Inhibition contributes to quadriceps strength deficits after an ACL injury. Body mass index, meniscal injury, and sex influence functional outcomes after ACL reconstruction. The purpose of this study is to examine the relationship of pre-operative quadriceps strength and post-operative knee function and to investigate how other pre-operative factors may influence this relationship.

METHODS

After an ACL injury, subjects received pre-operative rehabilitation and performed quadriceps strength testing. Subjects underwent reconstruction and post-operative rehabilitation. Six months after ACL reconstruction, subjects completed the International Knee Documentation Committee 2000 subjective form (IKDC2000). Linear regression models were developed using IKDC2000 scores at 6 months after ACL reconstruction as the dependent variable.

RESULTS

Fifty-five subjects had complete pre-operative data and IKDC2000 scores at 6 months after ACL reconstruction. Pre-operative involved quadriceps strength was a significant predictor for IKDC2000 scores 6 months after ACL reconstruction. Sex, meniscal injury, pre-operative BMI, and pre-operative involved quadriceps activation ratio were not significant predictors in the regression model.

CONCLUSIONS

Pre-operative quadriceps strength can predict IKDC2000 scores 6 months after ACL reconstruction. Deficits in pre-operative quadriceps strength influence self-reported function 6 months after surgery. Factors that are known to influence quadriceps strength and self-reported outcomes do not influence the relationship between pre-operative quadriceps strength and post-operative IKDC2000 scores.

Single-legged hop tests as predictors of self-reported knee function after anterior cruciate ligament reconstruction: the Delaware-Oslo ACL cohort study

BACKGROUND

Single-legged hop tests are commonly used functional performance measures that can capture limb asymmetries in patients after anterior cruciate ligament (ACL) reconstruction. Hop tests hold potential as predictive factors of self-reported knee function in individuals after ACL reconstruction.

HYPOTHESIS

Single-legged hop tests conducted preoperatively would not and 6 months after ACL reconstruction would predict self-reported knee function (International Knee Documentation Committee [IKDC] 2000) 1 year after ACL reconstruction.

STUDY DESIGN

Cohort study (prognosis); Level of evidence, 2.

METHODS

One hundred twenty patients who were treated with ACL reconstruction performed 4 single-legged hop tests preoperatively and 6 months after ACL reconstruction. Self-reported knee function within normal ranges was defined as IKDC 2000 scores greater than or equal to the age- and sex-specific normative 15th percentile score 1 year after surgery. Logistic regression analyses were performed to identify predictors of self-reported knee function within normal ranges. The area under the curve (AUC) from receiver operating characteristic curves was used as a measure of discriminative accuracy.

RESULTS

Eighty-five patients completed single-legged hop tests 6 months after surgery and the 1-year follow-up with 68 patients classified as having self-reported knee function within normal ranges 1 year after reconstruction. The crossover hop and 6-m timed hop limb symmetry index (LSI) 6 months after ACL reconstruction were the strongest individual predictors of self-reported knee function (odds ratio, 1.09 and 1.10) and the only 2 tests in which the confidence intervals of the discriminatory accuracy (AUC) were above 0.5 (AUC = 0.68). Patients with knee function below normal ranges were over 5 times more likely of having a 6-m timed hop LSI lower than the 88% cutoff than those with knee function within normal ranges. Patients with knee function within normal ranges were 4 times more likely to have a crossover hop LSI greater than the 95% cutoff than those with knee function below normal ranges. No preoperative single-legged hop test predicted self-reported knee function within normal ranges 1 year after ACL reconstruction (all P > .353).

CONCLUSION

Single-legged hop tests conducted 6 months after ACL reconstruction can predict the likelihood of successful and unsuccessful outcome 1 year after ACL reconstruction. Patients demonstrating less than the 88% cutoff score on the 6-m timed hop test at 6 months may benefit from targeted training to improve limb symmetry in an attempt to normalize function. Patients with minimal side-to-side differences on the crossover hop test at 6 months possibly will have good knee function at 1 year if they continue with their current training regimen. Preoperative single-legged hop tests are not able to predict postoperative outcomes.

Guideline on anterior cruciate ligament injury

The Dutch Orthopaedic Association has a long tradition of development of practical clinical guidelines. Here we present the recommendations from the multidisciplinary clinical guideline working group for anterior cruciate ligament injury. The following 8 clinical questions were formulated by a steering group of the Dutch Orthopaedic Association. What is the role of physical examination and additional diagnostic tools? Which patient-related outcome measures should be used? What are the relevant parameters that influence the indication for an ACL reconstruction? Which findings or complaints are predictive of a bad result of an ACL injury treatment? What is the optimal timing for surgery for an ACL injury? What is the outcome of different conservative treatment modalities? Which kind of graft gives the best result in an ACL reconstruction? What is the optimal postoperative treatment concerning rehabilitation, resumption of sports, and physiotherapy? These 8 questions were answered and recommendations were made, using the "Appraisal of Guidelines for Research and Evaluation" instrument. This instrument seeks to improve the quality and effectiveness of clinical practical guidelines by establishing a shared framework to develop, report, and assess. The steering group has also developed 7 internal indicators to aid in measuring and enhancing the quality of the treatment of patients with an ACL injury, for use in a hospital or practice.

Variability in leg muscle power and hop performance after anterior cruciate ligament reconstruction

PURPOSE

The purpose of this prospective study was to describe the variability in leg muscle power and hop performance up to 2 years among patients following ACL reconstruction and specifically to illustrate the effects of various criteria for an acceptable level of muscle function.

METHODS

Eighty-two patients (56 men and 26 women)with a mean age of 28 years, who underwent ACL reconstruction using either hamstring tendons (n = 46) or a patellar tendon (n = 36), were assessed pre-operatively and 3, 6, 12 and 24 months post-surgery with a battery of three lower extremity muscle power tests and a battery of three hop tests.

RESULTS

Leg symmetry index (LSI) values at group level ranged between 73 and 100% at all follow-ups. When the tests were evaluated individually, patients reached an average LSI of ≥ 90% at 24 months. The success rate at 24 months for the muscle power test battery, that is,patients with an LSI of ≥ 90% in all three tests, was 48 and 44% for the hop test battery. The success rate at 24 months for both test batteries on all six muscle function tests was 22%. The criterion of an LSI of ≥ 80% resulted in 53% of the patients having an acceptable level on all six tests,while with a criterion of an LSI of ≥ 100%, none of the patients reached an acceptable level.

CONCLUSION

At group level and in single muscle function tests, the muscle function outcome 1 and 2 years after ACL reconstruction is satisfactory in the present study and on a par with the results presented in the literature. However,when using more demanding criteria for a successful muscle function outcome, using batteries of tests or increasing the acceptable LSI level from ≥ 90% to ≥ 95%or ≥ 100%, the results are considered to be poor. It is suggested that this should be taken into consideration when presenting results after ACL rehabilitation, deciding on the criteria for a safe return to sports, or designing rehabilitation programmes after ACL reconstruction.

LEVEL OF EVIDENCE

Prognostic prospective cohort study, Level I.

Pre-operative factors predicting good outcome in terms of health-related quality of life after ACL reconstruction

The life situation of many patients changes after an anterior cruciate ligament (ACL) rupture and subsequent reconstruction, and this may affect their health-related quality of life in many ways. It is well known that the overall clinical results after ACL reconstruction are considered good, but pre-operative predictive factors for a good post-operative clinical outcome after ACL reconstruction have not been studied in as much detail. The purpose of this study was to identify pre-operative factors that predict a good post-operative outcome as measured by the Short Form 36 (SF-36) and Knee Osteoarthritis Outcome Score (KOOS) 3-6 years after ACL reconstruction. Seventy-three patients scheduled for ACL reconstruction were clinically examined pre-operatively. The SF-36 and KOOS questionnaires were sent by mail to these patients 3-6 years after reconstruction. Predictive factors for health-related quality of life were investigated using a stepwise regression analysis. In conclusion, pre-operative factors, such as pivot shift, knee function, and range of motion, may predict a good post-operative outcome and explain up to 25% in terms of health-related quality of life after ACL reconstruction. Furthermore, it appears that the patients' pre-injury and pre-operative Tegner activity levels are important predictors of post-operative health-related quality of life.

Age as a predictor of residual muscle weakness after anterior cruciate ligament reconstruction

PURPOSE

The objective of this study was to reveal the predicting factors for muscle recovery in the lower extremity after anterior cruciate ligament (ACL) reconstruction.

METHODS

One hundred and thirty-five (135) patients who underwent ACL reconstruction using hamstring autograft were evaluated. Exclusion criteria were bilateral ACL injury, chondral treatment and multiple ligament injury. Nonanatomical single-bundle reconstruction (SB) was performed in 79 patients, and anatomical double-bundle reconstruction (DB) was performed in 56 patients. Strength of quadriceps and knee flexion muscles were assessed at 60°/s using a Cybex II dynamometer (Lumex, Ronkonkoma, NY) at 3, 6 and 9 months after ACL reconstruction. Anterior tibial translation and pivot shift test were also evaluated. The medical records were reviewed to extract the following information: age, gender, the amount of pre and postoperative KT 1000, technique of reconstruction (SB or DB) and postoperative knee rotation.

RESULTS

No significant difference of muscle recovery in the lower extremity was observed at any time point after ACL reconstruction between the SB and DB groups. The DB group showed significantly better postoperative antero-posterior and rotational knee laxity than the SB group. Logistic regression analysis showed significant correlation with only age and muscle recovery.

CONCLUSION

For clinical relevance, there is a risk of muscle recovery delay when ACL reconstruction is performed in elderly patients. Anatomical DB reconstruction resulted in significantly better knee stability, but had no positive effect on muscle recovery.

LEVEL OF EVIDENCE

Retrospective study, Level II.

Muscle strength and hop performance criteria prior to return to sports after ACL reconstruction

PURPOSE

The purpose of this article is to present recommendations for new muscle strength and hop performance criteria prior to a return to sports after anterior cruciate ligament (ACL) reconstruction.

METHODS

A search was made of relevant literature relating to muscle function, self-reported questionnaires on symptoms, function and knee-related quality of life, as well as the rate of re-injury, the rate of return to sports and the development of osteoarthritis after ACL reconstruction. The literature was reviewed and discussed by the European Board of Sports Rehabilitation in order to reach consensus on criteria for muscle strength and hop performance prior to a return to sports.

RESULTS

The majority of athletes that sustain an (ACL) injury do not successfully return to their pre-injury sport, even though most athletes achieve what is considered to be acceptable muscle function. On self-reported questionnaires, the athletes report high ratings for fear of re-injury, low ratings for their knee function during sports and low ratings for their knee-related quality of life.

CONCLUSION

The conclusion is that the muscle function tests that are commonly used are not demanding enough or not sensitive enough to identify differences between injured and non-injured sides. Recommendations for new criteria are given for the sports medicine community to consider, before allowing an athlete to return to sports after an ACL reconstruction.