Simple decision rules can reduce reinjury risk by 84% after ACL reconstruction: the Delaware-Oslo ACL cohort study

Young age and high BMI are predictors of early revision surgery after primary anterior cruciate ligament reconstruction: a cohort study from the Swedish and Norwegian knee ligament registries based on 30,747 patients

PURPOSE

To analyse patient-related risk factors for 2-year ACL revision after primary reconstruction. The hypothesis was that younger athletes would have a higher incidence of an early ACL revision.

METHODS

This prospective cohort study was based on data from the Norwegian and Swedish National Knee Ligament Registries and included patients who underwent primary ACL reconstruction from 2004 to 2014. The primary end-point was the 2-year incidence of ACL revision. The impact of activity at the time of injury, patient sex, age, height, weight, BMI, and tobacco usage on the incidence of early ACL revision were described by relative risks (RR) with 95% confidence intervals (CI).

RESULTS

A total of 58,692 patients were evaluated for eligibility and 30,591 patients were included in the study. The mean incidence of ACL revision within 2 years was 2.82% (95% CI 2.64-3.02%). Young age (13-19) was associated with an increased risk of early ACL revision (males RR = 1.54 [95% CI 1.27-1.86] p < 0.001 and females RR = 1.58 [95% CI 1.28-1.96] p < 0.001). Females over 1 SD in weight ran an increased risk of early ACL revision (RR = 1.82, [95% CI 1.15-2.88] p = 0.0099). Individuals with a BMI of over 25 ran an increased risk of early ACL revision (males: RR = 1.78, [95% CI 1.38-2.30] p < 0.001 and females: RR = 1.84, [95% CI 1.29-2.63] p = 0.008).

CONCLUSION

Young age, a BMI over 25, and overweight females were risk factors for an early ACL revision.

LEVEL OF EVIDENCE

II.

Knee extensor strength and hop test performance following anterior cruciate ligament reconstruction

BACKGROUND

Knee extensor strength and single limb hop for distance have been suggested as useful measures to evaluate readiness to return to sport after anterior cruciate ligament (ACL) reconstruction. The aim of the study was to examine the association between knee extensor strength and single leg hop for distance following ACL reconstruction and to determine the proportion of patients with knee extensor strength symmetry deficits at six and 12 months.

METHODS

From December 2013 to December 2015 69 patients aged 14 to 45 undergoing primary ACL reconstruction were recruited. Isokinetic concentric knee extensor strength testing and single limb hop for distance were performed six and 12 months postoperatively. Satisfactory knee extensor strength was defined as a leg symmetry index (LSI) ≥85%.

RESULTS

At six months 27.5% (19/69) of patients had recovered satisfactory knee extensor strength in the injured leg, improving to 46.4% (32/69) at 12 months. Recovery of satisfactory strength was associated with hopping distance. Hop symmetry was achieved considerably faster than knee extensor symmetry, with 66.7% (46/69) of patients demonstrating satisfactory hopping symmetry at six months, 89.9% (62/69) at 12 months. Recovery of hopping distance was not associated with knee extensor strength.

CONCLUSIONS

Single leg hop test cannot be used as a surrogate measure for knee extensor strength as no association was found between hop tests and knee extensor strength. Less than one in three patients at six months and one in two at 12 months had recovered satisfactory knee extensor strength.

Jumping performance based on duration of rehabilitation in female football players after anterior cruciate ligament reconstruction

PURPOSE

To determine if female football players who had longer durations of rehabilitation, measured in months, after anterior cruciate ligament reconstruction would have lower tuck jump scores (fewer technique flaws) and smaller asymmetries during drop vertical jump landing.

METHODS

One-hundred-and-seventeen female football players, aged 16-25 years, after primary unilateral ACL reconstruction (median 16 months, range 6-39) were included. Athletes reported the duration of rehabilitation they performed after anterior cruciate ligament reconstruction. Athletes also performed the tuck jump and drop vertical jump tests. Outcome variables were: tuck jump score, frontal plane knee motion and probability of peak knee abduction moment during drop vertical jump landing.

RESULTS

There was no difference in tuck jump score based on duration of rehabilitation (n.s.). No interaction (n.s.), difference between limbs (n.s.), or duration of rehabilitation (n.s.) was found for peak knee abduction moment during drop vertical jump landing. No interaction (n.s.) or difference between limbs (n.s.) was found for frontal plane knee motion, but there was a difference based on duration of rehabilitation (P = 0.01). Athletes with > 9 months of rehabilitation had more frontal plane knee motion (medial knee displacement) than athletes with < 6 months (P = 0.01) or 6-9 months (P = 0.03).

CONCLUSION

As there was no difference in tuck jump score or peak knee abduction moment based on duration of rehabilitation, the results of this study press upon clinicians the importance of using objective measures to progress rehabilitation and clear athletes for return to sport, rather than time alone.

LEVEL OF EVIDENCE

II.

Fatigue affects quality of movement more in ACL-reconstructed soccer players than in healthy soccer players

PURPOSE

Athletes who meet return to play (RTP) criteria after anterior cruciate ligament reconstruction (ACLR) rehabilitation still have a substantially increased risk of second ACL injury. One of the contributing factors to this increased risk could be that the RTP criteria are often not tested in an ecologically valid environment and in a fatigued state. The purpose of this cross-sectional case-control study was to investigate the influence of neuromuscular fatigue on both movement quantity and quality in fully-rehabilitated soccer players after ACLR and to compare them with healthy soccer players.

METHODS

ACL-reconstructed soccer players (n = 14) and healthy soccer players (n = 19) participated in the study and were matched by playing level and training hours. RTP measurements were performed on the soccer field, in both a non-fatigued and fatigued state. The RTP measurements focussed on both movement quantity (hop tests) and quality [countermovement jump with a Landing Error Scoring System (LESS) score].

RESULTS

Movement quantity did not differ between ACL-reconstructed and healthy soccer players, both expressed in absolute values and the LSI-D/ND (calculated as dominant/non-dominant*100%). However, movement quality decreased more in the ACL-reconstructed soccer players in the fatigued state compared to the non-fatigued state.

CONCLUSIONS

Ideally, RTP measurements should focus on movement quality and should be conducted on the soccer field in a fatigued state, creating an ecologically valid environment. The LSI-D/ND can be used as an outcome parameter for RTP measurements of movement quantity and should be at least 95%.

LEVEL OF EVIDENCE

Therapeutic, Level III.

Only one patient out of five achieves symmetrical knee function 6 months after primary anterior cruciate ligament reconstruction

PURPOSE

To assess the percentage of patients achieving symmetrical knee function 6 months after primary anterior cruciate ligament (ACL) reconstruction (ACLR) and to identify factors affecting its achievement, in a large cohort.

METHODS

Data were extracted from our clinic database. Patients who underwent primary ACLR from 2000 to 2015 and were assessed with the isokinetic quadriceps and hamstring muscles strength tests and single-leg-hop test at the 6-month follow-up were included in the study. Demographic data, information on the graft used, cartilage injuries and concomitant meniscal surgery were reviewed. Patients who reached a limb symmetry index (LSI) of ≥ 90% in all three tests were considered to have achieved symmetrical knee function. A multivariate logistic regression analysis was used to determine whether patient age, gender, time from injury to surgery, pre-injury Tegner activity level, graft type, cartilage injury and the presence of medial meniscus (MM) or lateral meniscus (LM) resection or repair were factors associated with the achievement of symmetrical knee function 6 months after primary ACLR.

RESULTS

A total of 4093 patients (54.3% males) with a mean age of 28.3 ± 10.7 years were included. Data from all three tests were available for 3541 patients. The proportion of patients that achieved a LSI of ≥ 90% was 35.7%, 47.3% and 67.9% for isokinetic quadriceps muscle strength, hamstring muscles strength and the single-leg-hop test, respectively. A total of 693 patients (19.6%) achieved symmetrical knee function, reaching a LSI of ≥ 90% in all three tests. Older age (≥ 30 years) (OR, 0.50; 95% CI 0.41-0.61; P < 0.001), MM resection (OR, 0.75; 95% CI 0.57-0.98; P = 0.03) and MM repair (OR, 0.63; 95% CI 0.40-0.98; P = 0.04) reduced the odds, whereas the use of hamstring tendon (HT) autograft (OR, 2.28; 95% CI 1.51-3.45; P < 0.001) over bone-patellar tendon-bone (BPTB) autograft increased the odds of achieving symmetrical knee function.

CONCLUSION

Only 19.6% of the patients achieved symmetrical knee function 6 months after primary ACLR. Age ≥ 30 years, MM resection and MM repair reduced the chance, whereas the use of HT autograft over BPTB autograft increased the chance of achieving symmetrical knee function 6 months after primary ACLR. This study shows that most of the patients are yet to regain symmetrical knee function 6 months after primary ACLR and, moreover, it identifies several factors affecting its achievement in a large cohort. The results of this study should be used to counsel patients about their expected functional recovery and to optimize rehabilitation and maximize knee function after ACLR.

LEVEL OF EVIDENCE

III.

Integrating the Evidence and Clinical Expertise in the Shared Decision and Graduated Return to Sport Process: A Time Series Case Study after Anterior Cruciate Ligament Rupture and Reconstruction

INTRODUCTION

Rehabilitation following anterior cruciate ligament (ACL) rupture is often characterized by a large discrepancy between the available scientific evidence and its implementation into practice.

PURPOSE

We aimed to research, selectively rate, and transfer the available evidence to the returntosport (RTS) process after ACL rupture adopting an athlete time series case study design.

CASE REPORT AND METHODS

The participant is a male athlete aged 33 who was diagnosed with an isolated right-sided total ACL rupture. Knee arthroscopy using semitendinosus tendon plastic (×4) was performed. For rehabilitation, a graded and shared decision RTS algorithm was derived from the existing evidence and all relevant decision-makers expertise. Starting with basic functional abilities and range of motion, the functional ability at each stage had to be achieved before the next stage was aimed. The corresponding therapeutic focus (in addition to standard therapy) was adopted to reach this goal. Functions to be tested were as follows: Knee function confidence, dynamic balance, isometric and isokinetic strength/torque testing, as well as jumping ability (single-leg hop and triple crossover hop for distance).

RESULTS

RTS was reached (Level 3) 5 months and (Level 2) 10 months post-surgery.

CONCLUSION

Integrating the available evidence and the clinical expertise of all relevant stakeholders into a shared decision and graduated RTS process after ACL rupture and reconstruction was feasible and successful. Particularly, multiple functional measurements in a time series approach to determine the actual rehabilitation focus seem promising.

Are athletes able to resume sport at six-month mean follow-up after anterior cruciate ligament reconstruction? Prospective functional and psychological assessment from the French Anterior Cruciate Ligament Study (FAST) cohort

BACKGROUND

The decision to return to sport following anterior cruciate ligament (ACL) reconstruction should not only be based on time since surgery. This study aimed to assess, using isokinetic and neuromuscular (hops) testing in a large group, postoperative objective functional recovery of the knee. The secondary objective was to determine the relationship between psychological, functional scores, and these postoperative tests.

METHODS

This prospective study included athletes who underwent surgery between 2013 and 2016 for an isolated full-thickness ACL tear. They received a complete evaluation of functional performance of the knee by isokinetic tests performed on a dynamometer to measure quadriceps and hamstring strength, and neuromuscular assessment based on single-leg hop tests. The main judgment criterion was satisfactory functional recovery (yes/no) defined as a difference of ≤10% both in the quadriceps 60°/s and the single hop at a minimum of four months of follow-up.

RESULTS

A total of 234 athletes were analyzed. The mean age was 28.4 ± 8.6 years. At 6.5 ± 1.7 months mean follow-up, 44 (18.5%) patients had satisfactory functional recovery of the knee. The correlations between isokinetic/hop tests and the different scores were variable. During follow-up, two patients presented with a graft tear and two with a contralateral ACL tear, all in the group with unsatisfactory functional recovery.

CONCLUSION

At a mean of six months after ACL reconstruction, objective functional recovery of the knee was generally unsatisfactory and this seemed to be a risk factor for recurrent tears.

LEVEL OF EVIDENCE

IV; case series.

Female Soccer Players With Anterior Cruciate Ligament Reconstruction Have a Higher Risk of New Knee Injuries and Quit Soccer to a Higher Degree Than Knee-Healthy Controls

BACKGROUND

Many patients with anterior cruciate ligament (ACL) reconstruction who return to sport suffer new ACL injuries or quit sports soon after returning.

PURPOSE

To prospectively follow a cohort of female soccer players with primary unilateral ACL reconstruction and matched knee-healthy controls from the same soccer teams to compare (1) the rate of new traumatic and nontraumatic knee injuries and other injuries, (2) the proportion of players who quit soccer, and (3) player-reported activity level and satisfaction with activity level and knee function.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A total of 117 active female soccer players (mean ± SD age, 19.9 ± 2.5 years) 18.9 ± 8.7 months after ACL reconstruction and 119 knee-healthy female soccer players (19.5 ± 2.5 years) matched from the same teams were prospectively followed for 2 years for new knee injuries, other injuries, soccer playing level, activity level according to the Tegner Activity Scale, and satisfaction with activity level and knee function.

RESULTS

Players with ACL reconstruction had a higher rate of new ACL injuries (n = 29 vs 8; 19 vs 4 per 100 player years; rate ratio [RR], 4.82; 95% CI, 2.20-10.54; P < .001), other traumatic knee injuries (29 vs 16 per 100 player years; RR, 1.84; 95% CI, 1.16-2.93; P < .01), and nontraumatic knee injuries (33 vs 9 per 100 player years; RR, 3.62; 95% CI, 2.11-6.21; P < .001) as compared with controls. There was no difference in the rate of other (not knee) injuries (43 vs 48 per 100 player years; RR, 0.90; 95% CI, 0.65-1.23; P = .494). During the 2-year follow-up, 72 (62%) players with ACL reconstruction quit soccer, as opposed to 43 (36%) controls ( P = .001). The median Tegner Activity Scale score decreased in both groups ( P < .001) but more for the ACL-reconstructed group ( P < .015).

CONCLUSION

Female soccer players with ACL reconstruction had nearly a 5-fold-higher rate of new ACL injuries and a 2- to 4-fold-higher rate of other new knee injuries, quit soccer to a higher degree, and reduced their activity level to a greater extent as compared with knee-healthy controls.

Current perspectives of Australian therapists on rehabilitation and return to sport after anterior cruciate ligament reconstruction: A survey

OBJECTIVES

To investigate views and practices of Australian therapists on rehabilitation and return to sport (RTS) after anterior cruciate ligament reconstruction (ACLR).

DESIGN

Survey-based study.

SETTING

Online survey platform.

PARTICIPANTS

Australian Physiotherapists and Accredited Exercise Physiologists (n = 223).

MAIN OUTCOME MEASURES

1) perceived benefit, timing and frequency of rehabilitation, 2) timing of RTS and information on RTS evaluation and discharge criteria.

RESULTS

Therapists preferred to consult patients for the first time at 1-4 days (27.8%), ≤7 days (25.6%) or 7-14 days (30.5%) post-surgery. Within the first 6 weeks, 82.1% of therapists preferred patient visitation 1-2 times per week. Between 3 and 6 months, therapists mainly recommended less frequent visitation with a focus on home exercises. While 22.0% and 53.8% of therapists were willing to discharge patients for sport at 6-9 and 9-12 months, respectively, 22.9% preferred 12-18 months. Common RTS considerations were functional capacity (98.7%), strength (87.0%), lower limb and trunk mechanics (96.0%) and psychological readiness (87.9%). Knee strength was evaluated via manual muscle testing (33.0%), hand held (26.7%) and isokinetic (11.8%) dynamometry. For functional evaluation, 84.3% of therapists employed a hop battery (≥2 hop tests).

CONCLUSIONS

This survey revealed variation in beliefs and practices surrounding rehabilitation and RTS evaluation in Australian therapists.

Angle-specific analysis of isokinetic quadriceps and hamstring torques and ratios in patients after ACL-reconstruction

Background

Strength deficits, muscle imbalances, and quadriceps inhibition are common after the surgical reconstruction of the anterior cruciate ligament (ACL), even after the patient’s returned-to-sport. Typically, asymmetries between the operated and non-operated leg as well as the hamstring/quadriceps (HQ) ratio are calculated using maximum isokinetic torque values. Moreover, the knee flexion angles, which correspond to the measured torque values, were not considered. Therefore, the aim of the study was to evaluate the usage of an angle-specific approach for the analysis of isokinetic data in patients after an ACL-reconstruction.

Methods

A cross-sectional laboratory study design was used to investigate the influence of leg (operated vs. non-operated) and two velocities on angle-specific isokinetic data. Concentric quadriceps and hamstring torques and ratios of 38 patients were assessed 6.6 months after ACL-reconstruction with a hamstring tendon graft. At a velocity of 60°/s and 180°/s, angle-specific torques and HQ-ratios were analyzed with conventional discrete parameters and a Statistical Parametric Mapping procedure, which evaluates continuous data. The relationship between angle-specific and conventional HQ-ratios was evaluated with Pearson correlation coefficients.

Results

Angle-specific torques and HQ-ratios were different between the operated and non-operated leg and between velocities. In the operated leg, the quadriceps deficit was higher at 60°/s in knee flexion angles > 50°. The HQ-ratios decreased with greater knee flexion at both velocities, but with a different magnitude. Around 30°, the HQ-ratios reached 1.0 and did not differ between the velocities, while leg differences were present from 40 to 60°. At the higher testing velocity, the maximum flexion torque occurred at greater knee flexion, whereas the maximum extension torque were present at a similar joint angle. The correlation coefficients between conventional and angle-specific HQ-ratios were low in knee angles < 35° and > 65° and varied according to leg and velocity.

Conclusions

The angle specific approach is recommended for future ACL-research, as it reveals strength deficits and imbalances, which were not captured by conventional parameters. The results provide a rationale for more specific joint angle and/or velocity based training and may help for return-to-sport decisions.

Perceptions of Rehabilitation and Return to Sport Among High School Athletes With Anterior Cruciate Ligament Reconstruction: A Qualitative Research Study

BACKGROUND

Adolescent athletes struggle to return to sport following anterior cruciate ligament reconstruction (ACLR) for physical and psychosocial reasons. The ability to integrate contextual evidence obtained directly from patients with the growing body of quantitative rehabilitation research may aid clinicians in taking an evidence-based approach to rehabilitation and return to sport within the adolescent population.

OBJECTIVES

To assess perceived barriers to return to sport, as well as positive and negative factors influencing recovery, among high school athletes with recent history of ACLR.

METHODS

This phenomenographic cross-sectional study included a sample of 10 high school-aged individuals (7 female, 3 male; mean ± SD age, 16.8 ± 1.1 years; time since surgery, 5.5 ± 1.4 months) who underwent ACLR and had not returned to sports. Participants completed a semi-structured interview focused on attitudes related to return to sport, perceived physical or psychosocial barriers to physical activity and return to sport, and rehabilitation characteristics that may facilitate or hinder return to sport.

RESULTS

Participants reported psychosocial barriers to return to sport with greater consistency than physical barriers. Consistently reported barriers included the feeling that sport-based activities were now associated with injury, a persistent sense of uncertainty regarding full recovery, and the sense that comparison to others with ACLR by parents or coaches hindered their ability to make progress in rehabilitation.

CONCLUSION

Early identification of athletes at risk for persistent psychosocial barriers, such as fear of reinjury and uncertainty regarding full recovery, and establishment of peer mentoring groups to facilitate psychosocial support throughout the rehabilitation process may be key components of a gradual, patient-centered approach to improving mental and physical readiness for return to sport. J Orthop Sports Phys Ther 2018;48(12):951-959. Epub 22 Jun 2018. doi:10.2519/jospt.2018.8277.

Hybrid Additive Microfabrication Scaffold Incorporated with Highly Aligned Nanofibers for Musculoskeletal Tissues

Background

Latest tissue engineering strategies for musculoskeletal tissues regeneration focus on creating a biomimetic microenvironment closely resembling the natural topology of extracellular matrix. This paper presents a novel musculoskeletal tissue scaffold fabricated by hybrid additive manufacturing method.

Methods

The skeleton of the scaffold was 3D printed by fused deposition modeling, and a layer of random or aligned polycaprolactone nanofibers were embedded between two frames. A parametric study was performed to investigate the effects of process parameters on nanofiber morphology. A compression test was performed to study the mechanical properties of the scaffold. Human fibroblast cells were cultured in the scaffold for 7 days to evaluate the effect of scaffold microstructure on cell growth.

Results

The tip-to-collector distance showed a positive correlation with the fiber alignment, and the electrospinning time showed a negative correlation with the fiber density. With reinforced nanofibers, the hybrid scaffold demonstrated superior compression strength compared to conventional 3D-printed scaffold. The hybrid scaffold with aligned nanofibers led to higher cell attachment and proliferation rates, and a directional cell organization. In addition, there was a nonlinear relationship between the fiber diameter/density and the cell actinfilament density.

Conclusion

This hybrid biofabrication process can be established as a highly efficient and scalable platform to fabricate biomimetic scaffolds with patterned fibrous microstructure, and will facilitate future development of clinical solutions for musculoskeletal tissue regeneration.

Athletic Trainers' Effect on Population Health: Improving Access to and Quality of Care

CONTEXT

The scope of athletic training practice combined with the magnitude of scholastic athletic injuries means that the scholastic athletic trainer (AT) is uniquely positioned to positively affect the overall health care of this population. The AT is equipped to serve in the prevention and primary management of injuries and return to activity of scholastic athletes. However, to optimize the musculoskeletal health of all athletes within a given setting, the gaps in clinical care must be continuously evaluated. Quality improvement (QI) approaches are often used to establish a framework for delivering care that promotes the best health status of the targeted population.

OBJECTIVE

To describe the creation, implementation, and early results of a QI initiative aimed at advancing the health of the scholastic athletes served in the Greenville County, South Carolina, school district.

DESIGN

Cohort study.

PATIENTS OR OTHER PARTICIPANTS

A total of 49 793 athletes.

MAIN OUTCOME MEASURE(S)

The QI framework consisted of a process that documented the magnitude of athletic injuries, established risk factors for injury, defined intervention steps for at-risk athletes, and evaluated the QI process before and after implementation. The results were regularly reported to participating stakeholders, including ATs, athletic directors, coaches, parents, and athletes.

RESULTS

After the QI process, injury rates decreased (absolute risk difference between the 2011-2012 and 2016-2017 academic years = 22%) and resources were more strategically allocated, which resulted in a decrease in health care costs of more than 50%.

CONCLUSIONS

Collectively, the QI framework as described provides a systematic process for empowering the AT as the foundation of the scholastic sports medicine team.

Criteria for return to running after anterior cruciate ligament reconstruction: a scoping review

OBJECTIVE

To describe the criteria used to guide clinical decision-making regarding when a patient is ready to return to running (RTR) after ACL reconstruction.

DESIGN

Scoping review.

DATA SOURCES

The MEDLINE (PubMed), EMBASE, Web of Science, PEDro, SPORTDiscus and Cochrane Library electronic databases. We also screened the reference lists of included studies and conducted forward citation tracking.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Reported at least one criterion for permitting adult patients with primary ACL reconstruction to commence running postoperatively.

RESULTS

201 studies fulfilled the inclusion criteria and reported 205 time-based criteria for RTR. The median time from when RTR was permitted was 12 postoperative weeks (IQR=3.3, range 5-39 weeks). Fewer than one in five studies used additional clinical, strength or performance-based criteria for decision-making regarding RTR. Aside from time, the most frequently reported criteria for RTR were: full knee range of motion or >95% of the non-injured knee plus no pain or pain <2 on visual analogue scale; isometric extensor limb symmetry index (LSI)>70% plus extensor and flexor LSI>70%; and hop test LSI>70%.

CONCLUSIONS

Fewer than one in five studies reported clinical, strength or performance-based criteria for RTR even though best evidence recommends performance-based criteria combined with time-based criteria to commence running activities following ACL reconstruction.

Psychological and Functional Readiness for Sport Following Advanced Group Training in Patients With Anterior Cruciate Ligament Reconstruction

BACKGROUND

Decreased psychological readiness for sport may contribute to poor return-to-sport rates after anterior cruciate ligament reconstruction (ACLR). Though advanced rehabilitation is used to improve functional readiness for sport after ACLR, the effect of advanced rehabilitation on psychological readiness is unknown.

OBJECTIVE

To examine changes in psychological and functional measures and readiness for sport based on these measures in patients with ACLR following advanced group training.

METHODS

In this retrospective cohort study, patients with primary ACLR enrolled in a 5-week group training program after completing traditional physical therapy. Data collection pretraining and posttraining included demographic information, the Anterior Cruciate Ligament-Return to Sport after Injury (ACL-RSI) scale, and single-leg hop testing (single, triple, crossover triple, and timed hops). Readiness for sport was based on criteria for the ACL-RSI scale score (low threshold, 56 points or greater; high threshold, 75 points or greater) and hop tests (90% or greater limb symmetry).

RESULTS

Fifty-eight patients (21 male) participated. Mean ACL-RSI scale scores, mean hop test limb symmetry, and the proportion of patients meeting ACL-RSI and hop test readiness-for-sport criteria significantly improved from pretraining to posttraining. Posttraining ACL-RSI scale scores were correlated with single hop (r = 0.269) and triple hop (r = 0.275) limb symmetry, yet changes in the measures were not significantly correlated. After training, only 53.4% (lower ACL-RSI threshold) or 37.9% (higher ACL-RSI threshold) of the sample met both psychological and functional readiness criteria.

CONCLUSION

Advanced group training following ACLR improved psychological and functional outcomes; however, further, individualized intervention may be needed to address residual deficiencies in some patients.

LEVEL OF EVIDENCE

Therapy, level 2b. J Orthop Sports Phys Ther 2018;48(11):864-872. Epub 12 Jun 2018. doi:10.2519/jospt.2018.8041.

Normative Quadriceps and Hamstring Muscle Strength Values for Female, Healthy, Elite Handball and Football Players

Risberg, MA, Steffen, K, Nilstad, A, Myklebust, G, Kristianslund, E, Moltubakk, MM, and Krosshaug, T. Normative quadriceps and hamstring muscle strength values for female, healthy, elite handball and football players. J Strength Cond Res 32(8): 2314–2323, 2018—This study presents normative values for isokinetic knee extension and flexion muscle strength tests in 350 elite, female, handball (n = 150) and football (n = 200) players. Isokinetic concentric muscle strength tests at 60°·sec⁻¹ were recorded bilaterally using a dynamometer. Peak torque (in Newton meter [N·m]), body mass normalized peak torque (N·m·kg⁻¹), and hamstring to quadriceps ratio (H:Q ratio) for dominant and nondominant legs were recorded. The female elite players were 20.9 ± 4.0 years, started playing at the elite level at the age of 18.2 ± 2.7 years, with a mean of 9.7 ± 2.2 hours of weekly in-season training. Handball players demonstrated greater quadriceps muscle strength compared with football players (11.0%) (p < 0.001), also when normalized to body mass (4.1%) (p = 0.012), but not for weight-adjusted hamstring muscle strength. The H:Q ratio was higher on the dominant compared with the nondominant leg for handball players only (p = 0.012).The H:Q ratio was significantly lower for handball players (0.58) compared with football players (0.60) (p < 0.02). These normative values for isokinetic knee extension and flexion torques of healthy, elite, female handball and football players can be used to set rehabilitation goals for muscle strength after injury and enable comparison with uninjured legs. Significantly greater quadriceps muscle strength was found for handball players compared with football players, also when normalized to body mass.

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.

High School Athletic Trainer Services for Knee Injuries

CONTEXT

Participation in high school athletics carries a substantial risk of musculoskeletal injury, particularly to the knee. However, limited information is available on the care being provided by athletic trainers (ATs) for athletes with these injuries.

DESIGN

Descriptive epidemiology study.

SETTING

Data on athletic training facility visits and AT services were collected from 147 high schools in 26 states.

PATIENTS OR OTHER PARTICIPANTS

High school student-athletes who participated in 13 boys' sports and 14 girls' sports and sustained a diagnosed knee injury during the 2011-2012 through 2013-2014 academic years. The ATs documented 6797 knee injuries, with 4242 sustained in boys' sports and 2555 sustained in girls' sports.

MAIN OUTCOME MEASURE(S)

The number of athletic training facility visits and individual AT services as well as the average, median, and interquartile range of athletic training facility visits (per injury) and AT services (per injury) were calculated by sport and for time-loss (TL; participation restricted for ≥24 hours) and non-time-loss (NTL; participation restricted for <24 hours) injuries.

RESULTS

In total, 28 788 athletic training facility visits were reported, with an overall average of 4 athletic training facility visits per knee injury over the 3-year period. Most athletic training facility visits (72.6%) were associated with NTL injuries, but the majority of AT services (68.6%) were associated with TL injuries. A total of 81 245 AT services were provided for all knee injuries. Therapeutic activities or exercise were the most common type of AT service (52.5%). Overall, an average of 12 AT services were reported per knee injury. Compared with NTL injuries, TL injuries had a larger average number of AT services per injury (34 versus 9; P < .001).

CONCLUSIONS

Knee injuries at the high school level are a considerable health care burden. This report demonstrates a high proportion of AT attention to the evaluation and treatment of these injuries. This study confirms the recommended management of knee injuries, with neuromuscular and therapeutic activities being the primary services after knee injury.

Time for a Different Approach to Anterior Cruciate Ligament Injuries: Educate and Create Realistic Expectations

Following an anterior cruciate ligament (ACL) injury, patients are often reassured that timely surgery followed by intensive physiotherapy will "fix their knee". Not only does this message create a false perception of uncomplicated return to sport (RTS), it also ignores the large body of evidence demonstrating a high RTS re-injury rate following ACL reconstruction. In this article, we propose an individualised approach to the management of ACL injuries that targets a shift away from early surgery and towards conservative management, with surgery 'as needed' and rehabilitation tailored to the patient's RTS goals. Education on the natural history of ACL injuries will ensure patients are not misguided into thinking surgery and intensive rehabilitation guarantees great outcomes. Further, understanding that conservative management is not inferior to surgery-and not more likely to cause knee osteoarthritis-will help the patient make an informed decision. For patients who opt for surgical management, rehabilitation must target strength and functional performance, avoid rapid increases in training load, and be guided by an RTS timeframe that is no shorter than 9 months. The content of rehabilitation should be similar for patients who opt for non-operative management, although the RTS timeframe will likely be shorter. All patients should receive education on the relationship between injury risk and training load, and understand that a home-exercise program is not inferior to intensive physiotherapist-led exercise.

Engineering the hard-soft tissue interface with random-to-aligned nanofiber scaffolds

Tendon injuries can be difficult to heal and have high rates of relapse due to stress concentrations caused by scar formation and the sutures used in surgical repair. Regeneration of the tendon/ligament-to-bone interface is critical to provide functional graft integration after injury. The objective of this study is to recreate the tendon-to-bone interface using a gradient scaffold which is fabricated by a one-station electrospinning process. Two cell phenotypes were grown on a poly-ε-caprolactone nanofiber scaffold which possesses a gradual transition from random to aligned nanofiber patterns. We assessed the effects of the polymer concentration, tip-to-collector distance, and electrospinning time on the microfiber diameter and density. Osteosarcoma and fibroblast cells were seeded on the random and aligned sections of scaffolds, respectively. A random-to-aligned cocultured tissue interface which mimicked the native transition in composition of enthesis was created after 96 h culturing. The results showed that the microstructure gradient influenced the cell morphology, tissue topology, and promoted enthesis formation. This study demonstrates a heterogeneous nanofiber scaffold strategy for interfacial tissue regeneration. It provides a potential solution for mimicking transitional interface between distinct tissues, and can be further developed as a heterogeneous cellular composition platform to facilitate the formation of multi-tissue complex systems.

Sex Differences on the Landing Error Scoring System Among Individuals With Anterior Cruciate Ligament Reconstruction

CONTEXT: 

After anterior cruciate ligament reconstruction (ACLR), women have a greater risk of incurring a second anterior cruciate ligament injury and they display different landing movement patterns than men. It remains unclear if clinical movement-assessment tools, such as the Landing Error Scoring System (LESS), can detect sex differences in movement patterns after ACLR.

OBJECTIVE: 

To compare total LESS scores and individual LESS errors between men and women with a history of ACLR.

DESIGN: 

Cross-sectional study.

SETTING: 

Laboratory.

PATIENTS OR OTHER PARTICIPANTS: 

A total of 168 individuals (41 men and 127 women; mean age: men = 20 years [range, 19-25 years], women = 19 years [range, 18-20 years]; mean time since surgery: men = 21 months [range, 12-36 months], women = 27.5 months [range, 17-39 months]) with a history of primary, unilateral ACLR.

MAIN OUTCOME MEASURE(S): 

Participants completed a minimum of 3 trials of a drop vertical-jump task scored using the LESS. The between-sexes difference in LESS score was assessed using analysis of covariance, whereas the associations between participant sex and errors on each LESS item were assessed using logistic or multinomial regression.

RESULTS: 

Women displayed a greater number of total landing errors (men = 4.6 ± 2.3, women = 6.1 ± 2.3; P < .001) and were more likely to commit errors in trunk flexion at initial contact (men = 4.9%, women = 23.6%; odds ratio [OR] = 4.94), medial knee position at initial contact (men = 17.1%, women = 42.5%; OR = 6.01), medial knee displacement (men = 24.4%, women = 73.2%; OR = 7.88), total joint displacement (1 error: men = 58.5%, women = 71.7%, OR = 2.10; 2 errors: men = 7.3%, women = 14.2%, OR = 3.71), and overall impression (1 error: men = 75.6%, women = 84.3%, OR = 3.24; 2 errors: men = 2.4%, women = 10.2%, OR = 12.89) compared with men.

CONCLUSIONS: 

Women with ACLR displayed worse LESS scores and were more likely to commit errors related to medial knee displacement and overall landing quality than men with ACLR.

Rehabilitation Practice Patterns Following Anterior Cruciate Ligament Reconstruction: A Survey of Physical Therapists

BACKGROUND

Recovery from anterior cruciate ligament reconstruction (ACLR) requires an intensive course of postoperative rehabilitation. Although guidelines outlining evidence-based rehabilitation recommendations have been published, actual practice patterns of physical therapists are unknown.

OBJECTIVES

To analyze the current landscape of clinical practice as it pertains to rehabilitation progression and the use of time and objective criteria in rehabilitation following ACLR.

METHODS

In this cross-sectional study, an online survey was distributed to members of the Academy of Orthopaedic Physical Therapy, the American Academy of Sports Physical Therapy, and the Private Practice Section of the American Physical Therapy Association between January and March 2017.

RESULTS

The study analyzed a sample of 1074 responses. Supervised physical therapy was reported to last 5 months or less by 56% of survey respondents. The most frequent time frames for activity progression were 3 to 4 months (58%) for jogging, 4 to 5 months (50%) for modified sports activity, and 9 to 12 months (40%) for unrestricted sports participation. More than 80% of respondents reported using strength and functional measures during rehabilitation. Of those physical therapists who assessed strength, 56% used manual muscle testing as their only means of strength testing. Single-limb hop testing (89%) was the most frequently reported measure used to allow patients to begin modified sports activity following ACLR. Performance criteria for strength and functional tests varied significantly across all phases of rehabilitation. The 45% of respondents who reported using patient-reported outcome measures indicated that just under 10% of those measures involved fear or athletic confidence scales.

CONCLUSION

Considerable variation in practice exists among American Physical Therapy Association members regarding rehabilitation following ACLR. This variability in practice may contribute to suboptimal outcomes and confusion among practitioners and patients. J Orthop Sports Phys Ther 2018;48(10):801-811. Epub 22 May 2018. doi:10.2519/jospt.2018.8264.

Patient Characteristics and Predictors of Return to Sport at 12 Months After Anterior Cruciate Ligament Reconstruction: The Importance of Patient Age and Postoperative Rehabilitation

Background:

Preventing and mitigating the risk of reinjury after anterior cruciate ligament reconstruction (ACLR) rest on variables including age, surgical restoration of knee stability, adequate physical function, and thorough and complete postoperative rehabilitation, but to what degree these factors influence return to sport is unclear.

Purpose:

To investigate factors predictive of return to sport 12 months after ACLR. The factors specifically evaluated were strength, hop function, self-reported knee function, patient age, and quality of postoperative rehabilitation.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

This study evaluated 113 patients approximately 12 months after ACLR using a rehabilitation grading tool, the subjective International Knee Documentation Committee (IKDC) form, and a return-to-sport battery consisting of maximal isokinetic quadriceps and hamstring strength and 4 functional hop tests. Mann-Whitney U tests and chi-square analyses were used to determine differences between patients who had or had not returned to sport. A subsequent binary logistic hierarchical regression determined the factors predictive of a patient’s return to sport. In those patients who had returned to sport, relationships between either age or level of rehabilitation and passing the return-to-sport battery were also investigated.

Results:

Complete rehabilitation (adjusted odds ratio [OR], 7.95; P = .009), age ≤25 years (adjusted OR, 3.84; P = .024), and higher IKDC scores (P < .001) were predictive of return to sport at 12 months. In participants who had returned to sport, 21% passed the return-to-sport battery compared with only 5% who did not. Of those who had returned to sport, 37% who underwent complete rehabilitation passed the return-to-sport battery as opposed to 5% who underwent incomplete rehabilitation. In patients aged ≤25 years, only 48% underwent complete rehabilitation, despite having returned to sport. Additionally, in this group of patients, 40% underwent complete rehabilitation and passed the physical performance battery as opposed to only 4% who did not undergo complete rehabilitation.

Conclusion:

Younger patients and higher subjective IKDC scores were predictive of return to sport. Patients who completed 6 months of rehabilitation incorporating jumping and agility tasks had a higher rate of return to sport, suggesting that postoperative rehabilitation is important in predicting return to sport. Specialists and physical therapists alike should stress the importance of thorough postoperative rehabilitation and adequate neuromuscular strength and function to patients whose goals are to return to sport.

Biomechanical Deficits at the Hip in Athletes With ACL Reconstruction Are Ameliorated With Neuromuscular Training

BACKGROUND

The efficacy of a neuromuscular training (NMT) program to ameliorate known hip biomechanical risk factors for athletes with anterior cruciate ligament reconstruction (ACLR) is currently unknown. Purpose/Hypothesis: The purpose was to quantify the effects of an NMT program on hip biomechanics among athletes with ACLR and to compare posttraining hip biomechanics with a control group. The hypotheses were that known hip biomechanical risk factors of anterior cruciate ligament (ACL) injury would be significantly reduced among athletes with ACLR after the NMT program and that posttraining hip biomechanics between the ACLR and control cohorts would not differ.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twenty-eight athletes (n = 18, ACLR; n = 10, uninjured) completed a 12-session NMT program. Biomechanical evaluation of a jump-landing task was done before and after completion of the program. Repeated measures analysis of variance was performed to understand the effect of NMT within the ACLR cohort. Two-way analysis of variance was used to compare both groups. Post hoc testing was done for significant interactions. Hip biomechanical variables at initial contact are reported.

RESULTS

The athletes with ACLR who completed the NMT program had a significant session × limb interaction ( P = .01) for hip external rotation moment and a significant main effect of session for hip flexion angle ( P = .049) and moment ( P < .001). There was a significant change for the involved ( P = .04; 528% increase) and uninvolved ( P = .04; 57% decrease) limbs from pre- to posttraining for hip rotation moment. The ACLR cohort had an increase in hip flexion angle (14% change) and a decrease in hip flexion moment (65% change) from pre- to posttraining. Posttraining comparison for these same hip biomechanical variables of interest revealed no significant interactions ( P > .05) between the ACLR and control cohorts. There was a significant main effect of group ( P = .02) for hip flexion angle, as the ACLR cohort demonstrated greater hip flexion angle than that of the control group.

CONCLUSION

For athletes with ACLR, hip biomechanical measures of ACL injury risk show significant improvements after completion of an NMT program.

CLINICAL RELEVANCE

Athletes with ACLR who are participating in an NMT program may ameliorate known hip biomechanical risk factors for an ACL injury.

Return to Level I Sports After Anterior Cruciate Ligament Reconstruction: Evaluation of Age, Sex, and Readiness to Return Criteria

Background:

Return to sport (RTS) after anterior cruciate ligament (ACL) reconstruction is a topic of current interest. The high reinjury rates reported in younger athletes may be due in part to an early RTS.

Purpose:

To determine the proportion of athletes who return to level I (jumping, hard pivoting, and cutting) sport at less than 1 year after ACL reconstruction and compare return rates by age and sex. A secondary purpose was to examine whether RTS is associated with some commonly used outcome criteria.

Methods:

A cohort of 1440 athletes (992 males, 448 females) satisfied criteria for inclusion in this study (primary ACL reconstruction, normal contralateral knee, no additional surgery within the first year after the reconstruction, and participation in level I sport on a weekly basis prior to injury). The proportion of athletes in this sample who had resumed level I sport by 12 months after surgery was recorded, along with measurements of knee function (single-legged hop symmetry), laxity (KT-1000 arthrometer), and self-reported outcomes (International Knee Documentation Committee [IKDC] subjective score). Limb symmetry index scores of 90 or higher, side-to-side difference in anterior knee laxity of 2 mm or less, and IKDC scores of 95 or higher were considered indicators of satisfactory recovery from surgery.

Results:

Rates of return to level I sport were significantly higher for athletes aged 25 years and younger (48% return rate) compared with older athletes (26-35 years, 32% return rate [P < .0001]; ≥36 years, 19% return rate [P < .001]). Male athletes who were in the ≤25-year and 26- to 35-year age brackets had significantly higher return rates than female athletes (52% vs 39% and 37% vs 18%, respectively), whereas no sex-based differences in RTS were seen after 36 years of age. A significantly higher proportion of younger patients met the selected indicators of a satisfactory recovery. Regardless of age, athletes had twice the odds of RTS if they had limb symmetry index scores of 90 or higher (P ≤ .0001) and 3 times the odds of RTS if they had IKDC scores of 95 or higher (P < .0001).

Conclusion:

Almost half of younger athletes (aged ≤25 years) in the current cohort returned to level I sports within 12 months after ACL reconstruction. Younger athletes were also more likely to meet criteria that indicate a satisfactory functional recovery and that have been used to indicate readiness to RTS. There may be a role for adjusting thresholds for these criteria based on age.

INFLUENCE OF PATIENT DEMOGRAPHICS AND GRAFT TYPES ON ACL SECOND INJURY RATES IN IPSILATERAL VERSUS CONTRALATERAL KNEES: A SYSTEMATIC REVIEW AND META-ANALYSIS

BACKGROUND

There are inconsistencies in the reported rates of second anterior cruciate ligament (ACL) injuries per limb, patients' sex and graft types after primary ACL reconstruction (ACLR). There are also inconsistencies regarding the influence of these factors on the occurrence of second ACL injury after primary ACLR.

PURPOSE

To determine the rate of second ACL injury, to either the ipsilateral graft or contralateral healthy ACL, as influenced by sex, age, and graft types and to determine the influence of sex, age, and graft types on the occurrence of second ACL injury after primary ACLR.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

A computerized search of MEDLINE, CINAHL, and SPORTDiscus was conducted using combinations of these terms: ACL, ACLR, re-injury, re-rupture, revisions, contralateral tear, ipsilateral graft tear, and second injury. Articles were required to report the number or percentage of sex, graft type, ipsilateral graft and contralateral ACL injuries after ACLR. Rates of second ACL injuries and pooled dichotomous data were calculated using random-effect proportion meta-analysis.

RESULTS

The pooled rate of second ACL injuries (ipsilateral graft and contralateral ACL) was 6.11%. A slightly higher rate of ipsilateral graft injuries (3.29%) than contralateral ACL injuries (2.82%) (OR: 1.09 [95%CI: 0.89, 1.34] was reported. Ipsilateral graft injuries occurred earlier (median: 20 months) than contralateral ACL injuries (median: 36.3 months). Men had lower rate of second ACL injuries (5.67%) than women (6.84%) (OR: 0.92 [95%CI: 0.70, 1.20]). Significantly higher rate of ipsilateral graft injuries (3.40%) occurred in men compared to contralateral ACL injuries (2.26%) (OR: 1.53 [95CI%: 1.33, 1.77]), while women had significantly higher rate of contralateral ACL injuries (3.75%) compared to ipsilateral graft injuries (3.09%) (OR: 0.73 [95%CI: 0.55, 0.96]). The rate of second ACL (ipsilateral graft and contralateral ACL) injuries was higher in patients with hamstring tendon (HT) autograft (5.83%) than bone-patella tendon-bone autograft (BPTB) (5.10%) (p = 0.04) and allografts (3.12%) (p<0.0001). The rate of ipsilateral graft injuries was significantly higher than contralateral ACL injuries in all graft types (p<0.001).

CONCLUSION

Injuries to the ipsilateral graft are more common than contralateral ACL, with ipsilateral graft injuries occurring nearly 16 months earlier after ACLR. More women sustain second ACL injuries compared to men, with men incurring more injuries to the ipsilateral graft and women to the contralateral ACL. Furthermore, second ACL injuries are more common in patients with HT autograft, BPTB autograft, and then allograft; with ipsilateral graft injuries higher than contralateral ACL injuries regardless of graft types.

LEVELS OF EVIDENCE

2a.

Strength and functional symmetry is associated with post-operative rehabilitation in patients following anterior cruciate ligament reconstruction

PURPOSE

To investigate strength and functional symmetry during common tests in patients after anterior cruciate ligament reconstruction (ACLR), and its association with post-operative rehabilitation.

METHODS

At a median 11.0 months post-surgery (range 10-14), 111 ACLR patients were assessed. A rehabilitation grading tool was employed to evaluate the duration and supervision of rehabilitation, as well as whether structured jumping, landing and agility exercises were undertaken. Patients completed the Noyes Activity Score (NSARS), maximal isokinetic knee extensor and flexor strength assessment, and a 4-hop test battery. Limb Symmetry Indices (LSIs) were calculated, presented for the entire group and also stratified by activity level. ANOVA evaluated differences between the operated and unaffected limbs across all tests. Correlations were undertaken to assess the relationship between post-operative rehabilitation and objective test LSIs.

RESULTS

The unaffected limb was significantly better (p < 0.0001) than the operated limb for all tests. Only 52-61 patients (47-55%) demonstrated LSIs ≥ 90% for each of the hop tests. Only 34 (30.6%) and 61 (55.0%) patients were ≥ 90% LSI for peak quadriceps and hamstring strength, respectively. Specifically in patients actively participating in jumping, pivoting, cutting, twisting and/or turning sports, 21 patients (36.8%) still demonstrated an LSI < 90% for the single hop for distance, with 37 patients (65.0%) at < 90% for peak knee extension strength. Rehabilitation was significantly associated with the LSIs for all tests.

CONCLUSION

Rehabilitation was significantly correlated with limb symmetry, and lower limb symmetry was below recommended criterion for many community-level ACLR patients, including those already engaging in riskier activities. It is clear that many patients are not undertaking the rehabilitation required to address post-operative strength and functional deficits, and are being cleared to return to sport (or are returning on their own accord) without appropriate evaluation and further guidance.

LEVEL OF EVIDENCE

IV.

REHABILITATION FOLLOWING ISOLATED POSTERIOR CRUCIATE LIGAMENT RECONSTRUCTION: A LITERATURE REVIEW OF PUBLISHED PROTOCOLS

BACKGROUND

Surgical outcomes following isolated posterior cruciate ligament reconstruction (PCLR) have been noted to be less satisfactory than the anterior cruciate ligament. Limited understanding of optimal rehabilitation has been implicated as a contributing factor.

HYPOTHESIS/PURPOSE

The purpose of this review was to gather the literature related to isolated PCLR rehabilitation, extract and summarize current rehabilitation guidelines, identify timeframes and functional measurements associated with common rehabilitation topics and provide recommendations for future research.

STUDY DESIGN

Literature review.

METHODS

A literature review was performed for scientific publications that include a detailed rehabilitation program following isolated PCLR, published between January 2005 and March 2018. Data related to weight-bearing, knee range of motion (ROM), brace usage, specific exercise recommendations and suggestions for return to running and sport activities were extracted and categorized.

RESULTS

A total of 44 articles met inclusion criteria. Post-operative weight-bearing was discussed in 35 articles with recommendations ranging from no restriction to 12 weeks of limitations. Forty-two articles recommended the use of immediate post-operative bracing, the majority of which positioned the knee in full extension, with duration of use ranging from one to 12 weeks post-operatively. Although 30 articles offered detailed descriptions of ROM activity, there was significant variability in timing of initiation, angular excursion and progression of range of motion. Suggested timeframes for returning to sports activity ranged from four to 12 months, with only four articles providing specific objective strength or functional performance criteria necessary for progression.

CONCLUSIONS

There is substantial variation in nearly all aspects of published descriptors of rehabilitation following isolated PCLR. Most protocols are based upon biomechanical principles and clinical expertise, relying solely on timeframe from surgery to support rehabilitation decision making. Evidence to compare patient outcomes with specific loading, ROM progression and exercise strategies is currently lacking. Only a small number of protocols incorporate the use of specific objective performance goals to facilitate return to sport decision making.

Validation of a Composite Test for Assessment of Readiness for Return to Sports After Anterior Cruciate Ligament Reconstruction: The K-STARTS Test

Background:

There is limited information on the appropriate timing of return to sports after anterior cruciate ligament (ACL) reconstruction. A composite test was developed to assess the athlete’s ability to return to sports after ACL reconstruction: the Knee Santy Athletic Return To Sport (K-STARTS) test.

Hypothesis:

The K-STARTS test meets validation criteria for an outcome score assessing readiness for return to sports after ACL reconstruction.

Study Design:

Diagnostic study.

Level of Evidence:

Level 3.

Methods:

A prospective comparative study identified 410 participants: 371 participants who had undergone ACL reconstruction and a control group of 39 healthy participants. The K-STARTS score is calculated as the sum of 7 tests (8 components), for a maximal value of 21 points. Construct validity, internal consistency, discriminant validity, and sensitivity to change were used to validate this new test.

Results:

The K-STARTS assessment showed a high completion rate (100%), high reproducibility (intraclass correlation coefficient, 0.87; coefficient of variation, 7.8%), and high sensitivity to change. There was moderate correlation with the ACL Return to Sports after Injury scale (ACL-RSI) and hop tests. There were no ceiling or floor effects. There was a significant difference between K-STARTS scores assessed at 6 and 8 months postoperatively (11.2 ± 2.7 vs 17.1 ± 3.2; P < 0.001). The K-STARTS score in the control group was significantly higher than that in the ACL reconstruction group (17.3 ± 2.1 and 13.7 ± 3.8, respectively; P < 0.001).

Conclusion:

The K-STARTS test is an objective outcome measure for functional improvement after ACL reconstruction.

Clinical Relevance:

It is important for the clinician to determine when return to sports is optimal after ACL reconstruction to reduce the current high risk of reinjury.

Continued Improvements in Quadriceps Strength and Biomechanical Symmetry of the Knee After Postoperative Anterior Cruciate Ligament Reconstruction Rehabilitation: Is It Time to Reconsider the 6-Month Return-to-Activity Criteria?

CONTEXT

  Patients who undergo anterior cruciate ligament reconstruction (ACLR) present with strength and biomechanical deficits at return to activity (RTA). Deficits in strength and biomechanical symmetry impair function during activity and may predispose patients to subsequent injury.

OBJECTIVE

  To compare strength and biomechanical function in patients with ACLR at RTA and more than 12 months post-ACLR.

DESIGN

  Descriptive laboratory study.

SETTING

  Research laboratory.

PATIENTS OR OTHER PARTICIPANTS

  A total of 20 participants (12 females, 8 males; age = 21.40 ± 5.60 years, height = 171.3 ± 10.2 cm, mass = 73.21 ± 19.41 kg) who had undergone ACLR and were cleared to RTA were recruited.

INTERVENTION(S)

  Strength was measured during knee extension and evaluated by the isometric and isokinetic quadriceps index. Biomechanical function was evaluated using symmetry values for sagittal-plane knee-joint rotations, changes in sagittal-plane knee-joint rotation, knee-extension moments, and changes in knee-extension moment that were recorded during a single-legged forward hop.

MAIN OUTCOME MEASURE(S)

  Self-reported function was measured using the International Knee Documentation Committee Subjective Knee Evaluation Form. Participants were assessed at RTA (212.25 ± 28.11 days) and more than 12 months post-ACLR (556.25 ± 230.89 days).

RESULTS

  At RTA, strength and biomechanical values were less than 80% symmetric. We observed improvements from RTA to more than 12 months post-ACLR for the isometric quadriceps index ( F_1,18 = 29.22, P < .001), isokinetic quadriceps index ( F_1,18 = 10.88, P = .004), sagittal-plane knee-joint rotations ( F_1,19 = 9.58, P = .006), change in sagittal-plane knee-joint rotations ( F_1,19 = 7.83, P = .01), knee-extension moments ( F_1,19 = 5.73, P = .03), change in knee-extension moments ( F_1,19 = 21.10, P < .001), and self-perceived function ( F_1,19 = 11.50, P = .003). Of the 7 variables that showed improvement at more than 12 months post-ACLR, only 3 met the recommended criteria (≥90%).

CONCLUSIONS

  Patients with ACLR showed asymmetry in strength and biomechanics at RTA. These asymmetries, along with self-perceived function, improved over time. However, despite improvements in strength and biomechanics at RTA, asymmetries of more than 10% were still present more than 12 months post-ACLR.

Functional and Patient-Reported Outcomes Improve Over the Course of Rehabilitation: A Secondary Analysis of the ACL-SPORTS Trial

BACKGROUND

The Anterior Cruciate Ligament-Specialized Post-Operative Return to Sports (ACL-SPORTS) randomized controlled trial was designed to address deficits in functional and patient-reported outcomes. The trial examined the effects of a secondary ACL prevention program that included progressive strengthening, agility training, plyometrics (SAP), and other components of current primary prevention protocols, with perturbation training (SAP + PERT group) and without PERT (SAP group). A secondary purpose of this study was to examine whether study outcomes differed between men and women.

HYPOTHESES

(1) Athletes in both the SAP and SAP + PERT groups will have improved knee function and patient-reported outcome measures from pre- to posttraining, (2) the SAP + PERT group would have higher outcome scores than the SAP group, and (3) outcomes will differ by sex.

STUDY DESIGN

Randomized controlled trial (NCT01773317).

LEVEL OF EVIDENCE

Level 2.

METHODS

A total of 79 athletes (39 women) were randomized into the SAP and SAP + PERT groups. All athletes had undergone primary ACL reconstruction and achieved 80% quadriceps strength limb symmetry (QI), full range of motion, had minimal effusion, and had no pain. Additionally, all had begun running again. Prior to and after the training program, athletes' QI, hopping, and patient-reported outcomes were assessed. Repeated-measures analyses of variance were used to determine whether there were differences between groups. Subsequently, the SAP and SAP + PERT groups were collapsed to analyze differences between sexes.

RESULTS

There were significant increases for all variables, with the exception of QI. There were no differences between the SAP and SAP + PERT groups. Both men and women made significant improvements in all knee function and patient-reported outcome measures except QI. Men made significant improvements in QI, whereas women did not.

CONCLUSION

The common elements of the training program that all athletes received (10 sessions of progressive strengthening, agility training, plyometrics, and secondary prevention) may be a beneficial addition to the return-to-sport phase of ACL reconstruction rehabilitation. The results suggest that women may require further quadriceps strengthening to maintain and improve QI, an important focus given the relationship between QI and risk for reinjury.

CLINICAL RELEVANCE

During the return-to-sport phase of ACL reconstruction rehabilitation, clinicians tend to shift their focus away from strengthening toward more advanced sports-related tasks. These results indicate that women in particular need continued focus on quadriceps strengthening.

Should Return to Sport be Delayed Until 2 Years After Anterior Cruciate Ligament Reconstruction? Biological and Functional Considerations

Anterior cruciate ligament (ACL) tears are common knee injuries sustained by athletes during sports participation. A devastating complication of returning to sport following ACL reconstruction (ACLR) is a second ACL injury. Strong evidence now indicates that younger, more active athletes are at particularly high risk for a second ACL injury, and this risk is greatest within the first 2 years following ACLR. Nearly one-third of the younger cohort that resumes sports participation will sustain a second ACL injury within the first 2 years after ACLR. The evidence indicates that the risk of second injury may abate over this time period. The incidence rate of second injuries in the first year after ACLR is significantly greater than the rate in the second year. The lower relative risk in the second year may be related to athletes achieving baseline joint health and function well after the current expected timeline (6-12 months) to be released to unrestricted activity. This highlights a considerable debate in the return to sport decision process as to whether an athlete should wait until 2 years after ACLR to return to unrestricted sports activity. In this review, we present evidence in the literature that athletes achieve baseline joint health and function approximately 2 years after ACLR. We postulate that delay in returning to sports for nearly 2 years will significantly reduce the incidence of second ACL injuries.

TWO YEAR ACL REINJURY RATE OF 2.5%: OUTCOMES REPORT OF THE MEN IN A SECONDARY ACL INJURY PREVENTION PROGRAM (ACL-SPORTS)

BACKGROUND

The Anterior Cruciate Ligament-Specialized Post-Operative Return to Sports (ACL-SPORTS) randomized control trial (RCT) examined an evidence-based secondary ACL injury prevention training program, involving progressive strengthening, agility training, and plyometrics. The RCT examined the benefit of the training program with and without a neuromuscular training technique called perturbation training.

HYPOTHESIS/PURPOSE

The purpose of this study was to report the return to sport and second ACL injury incidence outcomes of the men in the ACL-SPORTS trial.

STUDY DESIGN

Secondary analysis of a RCT.

METHODS

Forty cutting and pivoting sport male athletes participated in the ACL-SPORTS trial, return to sport testing, and in follow-up sessions at one and two years after ACL reconstruction. Variables of interest at one and two years were return to sport, return to preinjury level of sport, and second ACL injuries. Mean time to passing return to sport criteria, the number of athletes returning to sport and preinjury level of sport and the incidence proportion of second ACL injuries were calculated.

RESULTS

Athletes passed return to sport criteria 232 ± 99 days after ACLR. One year after ACL reconstruction 95% had returned to sport, 78% at their preinjury level. Two years after ACL reconstruction all athletes had returned to sport, 95% at their preinjury level and only one athlete had a second ACL injury.

CONCLUSIONS

The results of this study indicate that men in the ACL-SPORTS trial had much higher return to sport rates and much lower second ACL injury rates than those reported in the literature.

LEVEL OF EVIDENCE

1b.

Low 1-Year Return-to-Sport Rate After Anterior Cruciate Ligament Reconstruction Regardless of Patient and Surgical Factors: A Prospective Cohort Study of 272 Patients

BACKGROUND

There is insufficient knowledge about the way that concomitant injuries affect the short-term likelihood of a return to a knee-strenuous sport after anterior cruciate ligament (ACL) reconstruction. Hypotheses/Purpose: The purpose was to study whether patient characteristics, concomitant injuries, and graft choice at primary ACL reconstruction can predict return to sport (RTS) 1 year after surgery. The hypotheses were that younger age at the time of ACL reconstruction would positively affect RTS, while the presence of concomitant injuries would negatively affect RTS 1 year after surgery.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Data were extracted from a rehabilitation-specific register and the Swedish National Knee Ligament Register. Twelve months after surgery, all patients were evaluated for RTS via the Tegner Activity Scale. The primary outcome was a return to knee-strenuous sport, defined as a Tegner Activity Scale ≥6. Univariable and multivariable logistic regression analyses were performed with patient characteristics, concomitant knee injuries, and graft choice as independent variables.

RESULTS

A total of 272 patients (51% female) with a mean ± SD age of 25.0 ± 9.2 years were included. In the multivariable analysis, a favorable odds ratio (OR) for returning to sport was found for patients of male sex (OR, 2.58; 95% CI, 1.43-4.65; P = .0016), younger age at the time of ACL reconstruction (OR, 2.32; 95% CI, 1.59-3.33; P < .0001), a higher preinjury score on the Tegner Activity Scale (OR, 1.45; 95% CI, 1.13-1.87; P = .0038), and an absence of injury to the meniscus (OR, 1.92; 95% CI, 1.10-3.36; P = .023) and medial collateral ligament (OR, 7.61; 95% CI, 1.42-40.87; P = .018). In addition, the absence of cartilage injury was favorable in terms of RTS in the univariable analysis (OR, 2.48; 95% CI, 1.40-4.39; P = .0018).

CONCLUSION

Positive predictors of a return to knee-strenuous sport 1 year after ACL reconstruction were male sex, younger age, a high preinjury level of physical activity, and the absence of concomitant injuries to the medial collateral ligament and meniscus.

COMPARISON OF THE 'BACK IN ACTION' TEST BATTERY TO STANDARD HOP TESTS AND ISOKINETIC KNEE DYNAMOMETRY IN PATIENTS FOLLOWING ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

BACKGROUND

Limb symmetry after anterior cruciate ligament reconstruction may be evaluated using maximal strength and hop tests, which are typically reported using Limb Symmetry Indices (LSIs) which may overestimate function.

PURPOSE

The purpose of this study was to compare the Back in Action (BIA) test battery to standard hop and muscle strength tests used to determine readiness to return to sport (RTS).

STUDY DESIGN

Prospective cohort.

METHODS

Over two test sessions, 40 ACLR patients were assessed at a mean 11.3 months post-surgery. Initially, participants completed the 6 m timed hop and the single, triple and triple crossover hops for distance, and isokinetic knee extensor and flexor strength assessment. The second session involved completion of the BIA battery, including stability tests, single and double leg countermovement jumps (CMJ), and plyometric, speedy jump, and quick feet tests. Pass rates for test batteries were statistically compared, including the BIA, a four-hop battery (≥90% LSI in every one of the four hop tests) and a combined 4-hop and strength battery (≥90% LSI in every one of the four hop tests, as well as ≥90% for both peak knee extensor and flexor strength). LSI differences between the four standard hop tests and the BIA single limb functional tests (the single limb CMJ and the speedy jump test) were evaluated.

RESULTS

Significantly less participants passed the BIA battery (n = 1, 2.5%), compared with the four-hop test battery (n = 27, 67.5%) (p<0.001) and the four-hop test and isokinetic strength battery (n = 17, 42.5%) (p<0.001). Collectively, LSI's for the standard hop tests were significantly higher than the BIA functional single limb tests (difference  =  12.9%, 95% CI: 11.1% to 14.6%, p<0.001).

CONCLUSION

The BIA test battery appears to include some single limb functional tests that are more physically challenging than standard hop and isokinetic strength tests, highlighted by the significantly lower mean LSI's during the single limb BIA tests and the lower pass rate when employing the BIA protocol.

LEVEL OF EVIDENCE

Level 4, case series.

Anterior Cruciate Ligament Injury-Who Succeeds Without Reconstructive Surgery? The Delaware-Oslo ACL Cohort Study

Background

More than 50% of highly active patients with an anterior cruciate ligament (ACL) injury who choose nonsurgical treatment (active rehabilitation alone) have successful 2-year outcomes and comparable knee function to an uninjured population. Early predictive factors for a successful outcome may aid treatment decision making in this population.

Purpose

To identify early predictors of a successful 2-year outcome in those who choose nonsurgical treatment of an ACL injury.

Study Design

Cohort study; Level of evidence, 2.

Methods

This prospective cohort study consisted of ACL-injured athletes who were consecutively screened for inclusion. A total of 300 patients were included from 2 sites (Oslo, Norway, and Delaware, USA), and the 118 patients who initially chose not to undergo ACL reconstruction were included. All patients participated in pivoting sports before the injury, and none had significant concomitant injuries. A successful 2-year outcome was defined as having 2-year International Knee Documentation Committee (IKDC) scores ≥15th normative percentile and not undergoing ACL reconstruction. Multivariable logistic regression models were built using demographic and knee function data (quadriceps muscle strength, 4 single-leg hop tests, IKDC score, and Knee Outcome Survey-Activities of Daily Living Scale [KOS-ADLS] score) collected at baseline or after a 5-week neuromuscular and strength training (NMST) rehabilitation program.

Results

After 2 years, 52 of 97 (53.6%) patients had a successful outcome. In the multivariable baseline model, older age, female sex, better performance on the single-leg hop test, and a higher KOS-ADLS score were significantly associated with successful 2-year outcomes. After the 5-week NMST rehabilitation program, older age, female sex, and a higher IKDC score increased the odds of a successful 2-year outcome. The 2 models had comparable predictive accuracy (post-NMST area under the curve [AUC], 0.78 [95% CI, 0.68-0.88]; baseline AUC, 0.81 [95% CI, 0.72-0.89]).

Conclusion

Clinicians and patients can be more confident in a nonsurgical treatment choice (active rehabilitation alone) in athletes who are female, are older in age, and have good knee function, as measured by single-leg hop tests and patient-reported outcome measures, early after an ACL injury. Prediction models that include measures of knee function, assessed either before or after rehabilitation, can estimate 2-year prognoses for nonsurgical treatment and thereby assist shared treatment decision making.

The current management of patients with patellofemoral pain from the physical therapist's perspective

Patellofemoral pain (PFP) is a common diagnosis that includes an amalgam of conditions that are typically non-traumatic in origin and result in peripatellar and/or retropatellar knee pain. The purpose of this review is to provide an overview of the physical therapist's management, including the evaluation and treatment, of the patient with PFP. A thorough history is critical for appropriately diagnosing and optimally managing PFP; the history should include the date of symptom onset, mechanism of injury and/or antecedent events, location and quality of pain, exacerbating and alleviating symptoms, relevant past medical history, occupational demands, recreational activities, footwear, and patient goals. Physical examination should identify the patient's specific impairments, assessing range of motion (ROM), muscle length, effusion, resisted isometrics, strength, balance and postural control, special tests, movement quality, palpation, function, and patient reported outcome measures. Objective assessments should guide treatment, progression, and clinical decision-making. The rehabilitation program should be individually tailored, addressing the patient's specific impairments and functional limitations and achieving the patient's goals. Exercise therapy, including hip, knee, and core strengthening as well as stretching and aerobic exercise, are central to the successful management of PFP. Other complimentary treatments may include patellofemoral and tibiofemoral joint mobilizations, patellofemoral taping, neuromuscular training, and gait retraining. Appropriate progression of interventions should consider objective evaluations (e.g., effusion, soreness rules), systematic increases in loading, and the chronicity of symptoms. Although short-term changes or reductions in movement often are necessary in a protective capacity, the persistence of altered movement is a key characteristic of chronic pain, which may be managed in part through emphasis on function over symptoms, graded exposure, patient education, and perhaps referral. PFP etiology is largely movement related and a comprehensive conservative treatment using movement can be successful.

Defining the Learning Curve for Hip Arthroscopy: A Threshold Analysis of the Volume-Outcomes Relationship

BACKGROUND

Hip arthroscopy has emerged as a successful option for the treatment of femoroacetabular impingement and related hip disorders, but the procedure is technically challenging.

PURPOSE

To define the learning curve through which surgeons become proficient at hip arthroscopy.

STUDY DESIGN

Cohort study; level of evidence, 3.

METHODS

The authors identified hip arthroscopy procedures performed by surgeons through a New York State database (Statewide Planning and Research Cooperative System) and followed those cases for additional hip surgery (total hip arthroplasty, hip resurfacing, or ipsilateral hip arthroscopy) within 5 years of the original procedure. Career volume for each case was calculated as the number of hip arthroscopy procedures that the surgeon had performed. Volume strata were identified via the stratum-specific likelihood ratio method. A Cox proportional hazards model was used to measure the effect of surgeon career volume on risk of additional hip surgery, adjusting for the following patient characteristics: age, sex, race/ethnicity, insurance type, and concurrent diagnosis of hip osteoarthritis.

RESULTS

Among 8041 hip arthroscopies performed by 251 surgeons, 989 (12.3%) cases underwent additional hip surgery within 5 years. Four strata of surgeon career volume associated with distinct frequencies of reoperation were identified: cases in the lowest stratum (0-97) had the highest frequency of additional surgery (15.4%). Frequencies declined for cases in the medium (98-388), high (389-518), and highest (≥519) strata (13.8%, 10.1%, and 2.6%, respectively). There was an increased risk of subsequent surgery in each stratum when compared with the highest stratum (hazard ratio [95% CI]: low volume, 3.22 [2.29-4.54]; medium, 3.40 [2.41-4.82]; high, 2.81 [1.86-4.25]; P < .0001 for all). Patients with a diagnosis of hip osteoarthritis had increased risk of subsequent hip arthroplasty or resurfacing (2.46 [2.09-2.89], P < .0001) . Risk also increased with age: 30 to 39 vs ≤29 years (5.12 [3.29-8.00], P < .0001), 40 to 49 vs ≤29 years (11.30 [7.43-17.190], P < .0001), ≥50 vs ≤29 years (18.39 [12.10-27.96], P < .0001). Increased age and osteoarthritis were not risk factors for revision hip arthroscopy.

CONCLUSION

The learning curve for hip arthroscopy was unexpectedly demanding. Cases performed by surgeons with career volumes ≥519 had significantly lower risk of subsequent hip surgery than those performed by lower-volume surgeons.

Comparison of Lower Extremity Recovery After Anterior Cruciate Ligament Reconstruction With Transphyseal Hamstring Versus Extraphyseal Iliotibial Band Techniques in Skeletally Immature Athletes

Background

The influence of graft type on recovery after anterior cruciate ligament reconstruction (ACLR) has not been adequately studied in pediatric patients.

Purpose

To describe lower extremity functional recovery parameters at the 6-month mark after ACLR across 3 distinct groups of skeletally immature patients: pediatric male patients with transphyseal hamstring grafts (PM-HS), pediatric female patients with transphyseal hamstring grafts (PF-HS), and pediatric male patients with extraphyseal iliotibial band grafts (PM-ITB).

Study Design

Cohort study; Level of evidence, 3.

Methods

Thigh circumference, knee range of motion, lower extremity strength, dynamic balance, and hop test performance were assessed in all patients 6 months postoperatively. All participants were ≤15 years of age with open physes. The limb symmetry index was used to compare deficits between the operated and uninvolved limbs for all 3 groups (PM-HS, PF-HS, and PM-ITB). Analysis of variance with post hoc correction was employed.

Results

A total of 93 pediatric patients who underwent ACLR (PM-HS: n = 21 [mean age, 13.6 ± 1.0 years]; PF-HS: n = 33 [mean age, 13.4 ± 0.7 years]; PM-ITB: n = 39 [mean age, 12.5 ± 1.3 years]) were examined. There was no statistically significant difference in thigh circumference, range of motion, dynamic balance, or hop test performance between the groups. Of the various additional comparisons analyzed, there were statistical differences in hamstring strength deficits among the 3 groups (P = .004). The PM-HS group showed a greater hamstring strength deficit (-32.2% relative to healthy limb) than the PM-ITB group (-5.4% relative to healthy limb) (P = .012). The hamstring strength deficit of the PF-HS group (-18.7% relative to healthy limb) was less than that of the PM-HS group and greater than that of the PM-ITB group but not statistically significant in either case.

Conclusion

Significant hamstring strength deficits were detected in the PM-HS group compared with the PM-ITB group at 6 months following ACLR. Such findings may influence decisions regarding graft selection, timing of return to sports, and postoperative rehabilitation regimens.

ACL reconstruction with hamstring tendon autograft and accelerated brace-free rehabilitation: a systematic review of clinical outcomes

OBJECTIVE

To investigate the clinical outcomes after hamstring tendon autograft ACL reconstruction (ACLR) with accelerated, brace-free rehabilitation.

DESIGN

Systematic review according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines.

DATA SOURCES

Embase, MEDLINE Ovid, Web of Science, Cochrane CENTRAL and Google scholar from 1 January 1974 to 31 January 2017.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Study designs reporting outcomes in adults after arthroscopic, primary ACLR with hamstring autograft and accelerated, brace-free rehabilitation.

RESULTS

Twenty-four studies were included in the review. The clinical outcomes after hamstring tendon autograft ACLR with accelerated brace-free rehabilitation were the following: (1) early start of open kinetic exercises at 4 weeks in a limited range of motion (ROM, 90°-45°) and progressive concentric and eccentric exercises from 12 weeks did not alter outcomes, (2) gender and age did not influence clinical outcomes, (3) anatomical reconstructions showed better results than non-anatomical reconstructions, (4) there was no difference between single-bundle and double-bundle reconstructions, (5) femoral and tibial tunnel widening occurred, (6) hamstring tendons regenerated after harvest and (7) biological knowledge did not support return to sports at 4-6 months.

CONCLUSIONS

After hamstring tendon autograft ACLR with accelerated brace-free rehabilitation, clinical outcome is similar after single-bundle and double-bundle ACLR. Early start of open kinetic exercises at 4 weeks in a limited ROM (90°-45°) and progressive concentric and eccentric exercises from 12 weeks postsurgery do not alter clinical outcome. Further research should focus on achievement of best balance between graft loading and graft healing in the various rehabilitation phases after ACLR as well as on validated, criterion-based assessments for safe return to sports.

LEVEL OF EVIDENCE

Level 2b; therapeutic outcome studies.

Contribution of Neuromuscular Factors to Quadriceps Asymmetry After Anterior Cruciate Ligament Reconstruction

CONTEXT

  To quantify quadriceps weakness after anterior cruciate ligament reconstruction (ACLR), researchers have often analyzed only peak torque. However, analyzing other characteristics of the waveform, such as the rate of torque development (RTD), time to peak torque (TTP), and central activation ratio (CAR), can lend insight into the underlying neuromuscular factors that regulate torque development.

OBJECTIVE

  To determine if interlimb neuromuscular asymmetry was present in patients with ACLR at the time of clearance to return to activity.

DESIGN

  Cross-sectional study.

SETTING

  Laboratory.

PATIENTS OR OTHER PARTICIPANTS

  A total of 10 individuals serving as controls (6 men, 4 women; age = 23.50 ± 3.44 years, height = 1.73 ± 0.09 m, mass = 71.79 ± 9.91 kg) and 67 patients with ACLR (43 men, 24 women; age = 21.34 ± 5.73 years, height = 1.74 ± 0.11 m, mass = 77.85 ± 16.03 kg, time postsurgery = 7.52 ± 1.36 months) participated.

MAIN OUTCOME MEASURE(S)

  Isokinetic (60°/s) and isometric quadriceps strength were measured. Peak torque, TTP, and RTD were calculated across isometric and isokinetic trials, and CAR was calculated from the isometric trials via the superimposed burst. Repeated-measures analyses of variance were used to compare limbs in the ACLR and control groups.

RESULTS

  No between-limbs differences were detected in the control group ( P > .05). In the ACLR group, the involved limb demonstrated a longer TTP for isokinetic strength ( P = .04; Cohen d effect size [ES] = 0.18; 95% confidence interval [CI] = -0.16, 0.52), lower RTD for isometric ( P < .001; Cohen d ES = 0.73; 95% CI = 0.38, 1.08) and isokinetic ( P < .001; Cohen d ES = 0.84; 95% CI = 0.49, 1.19) strength, lower CAR ( P < .001; Cohen d ES = 0.37; 95% CI = 0.03, 0.71), and lower peak torque for isometric ( P < .001; Cohen d ES = 1.28; 95% CI = 0.91, 1.65) and isokinetic ( P < .001; Cohen d ES = 1.15; 95% CI = 0.78, 1.52) strength.

CONCLUSIONS

  Interlimb asymmetries at return to activity after ACLR appeared to be regulated by several underlying neuromuscular factors. We theorize that interlimb asymmetries in isometric and isokinetic quadriceps strength were associated with changes in muscle architecture. Reduced CAR, TTP, and RTD were also present, indicating a loss of motor-unit recruitment or decrease in firing rate.

Revision Anterior Cruciate Ligament Reconstruction Outcomes in Younger Patients: Medial Meniscal Pathology and High Rates of Return to Sport Are Associated With Third ACL Injuries

BACKGROUND

There are limited data evaluating the outcomes of revision anterior cruciate ligament (ACL) reconstruction surgery in younger patients despite recent reports that the rates of graft rupture are higher in young cohorts.

PURPOSE

To explore the outcomes of revision ACL reconstruction surgery in younger patients with the specific aims of determining the rates of third ACL injury and whether knee pathology at the time of revision surgery and return to sport were associated with further injury.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

The study cohort consisted of 151 consecutive patients who were aged 25 years or younger at the time of their first revision ACL reconstruction. The number of subsequent ACL injuries (graft rerupture or contralateral injury to the native ACL) was determined at a mean follow-up time of 4.5 years (range, 2-9 years). Surgical details were recorded, along with a range of sport participation outcomes. Contingency tables were used to assess the associations between subsequent ACL injury and return to sport, knee pathology, and the drilling of new femoral or tibial tunnels at revision surgery.

RESULTS

The follow-up rate was 85% (128/151). Graft reruptures occurred in 20 patients (16%) at a mean time of 2 years after revision surgery. Contralateral ACL injuries occurred in 15 patients (12%) at a mean time of 3.9 years. The total number of patients who had a third ACL injury was 35 (27%). There was a significant association between having medial meniscal pathology and sustaining a graft rerupture ( P = .03), but there was no association between graft rerupture and using the same tunnels from the primary procedure at revision surgery. After revision reconstruction, 68% of patients (95% CI, 55%-71%) returned to their preinjury level of sport, compared with 83% (95% CI, 69%-84%) after primary reconstruction in the same patients. Those who had a third ACL injury had a significantly higher rate of return to preinjury sport (83%) after the revision procedure than did the group that did not have further ACL injuries (62%, P = .02).

CONCLUSION

Younger patients are at significant risk of having multiple ACL injuries. The high rate of third ACL injuries presents a significant issue for future knee health in these young athletes. Medial meniscal pathology and returning to high-risk sport are factors that are significantly associated with the high multiple ACL injury rate in the young.

COMPARISON OF CLINICAL FATIGUE PROTOCOLS TO DECREASE SINGLE-LEG FORWARD HOP PERFORMANCE IN HEALTHY INDIVIDUALS

BACKGROUND

Return to activity decisions after anterior cruciate ligament reconstruction (ACL-R) are limited by functional performance tests often performed in a non-fatigued state. Fatigue can improve test sensitivity, but current methods to induce fatigue are typically bilateral tasks or focus on the quadriceps muscle in isolation.

HYPOTHESIS/PURPOSE

To determine the effects of a two-minute lateral step-down fatigue test compared to a 30-second side-hop test on single-leg forward hop distance in healthy individuals. It was hypothesized that participants would demonstrate decreased hop distance with both tests, but the two-minute lateral step-down fatigue test would result in greater deficits in single-leg forward hop distance.

STUDY DESIGN

Randomized crossover.

METHODS

Twenty healthy participants (16 females, 4 males; age = 23.7±3.0 years, height = 153.8±36.2 cm; mass = 64.4±12.8 kg; Tegner = 6.8±1.2) were asked to perform single-leg forward hop for distance pre- and post-fatigue. Participants were randomly assigned to one of the two fatigue tests, 30-second side-hop or 2-minute lateral step-down test, during the first visit. They returned within a week and performed the same sequence of tests but underwent whichever fatigue test was not assigned at the prior visit.

RESULTS

There was a significant decrease (p < 0.001) in single-leg forward hop distance following the 30-second side-hop test (pre = 134.1±23.7 cm, post = 126.2±24.4 cm) and the two-minute lateral step-down test (pre = 135.0±26.1 cm, post = 122.7±27.4 cm). The decrease in hop distance was significantly greater (p < 0.001) for the two-minute lateral step-down test compared to the 30-second side-hop test.

CONCLUSION

The two-minute lateral step-down test resulted in a greater decrease in hop performance compared to the 30-second side-hop test. The results establish a threshold for expected changes that occur in a healthy population and that can then be compared with an injured athlete population. The two-minute lateral step-down exercise may be an effective method of inducing fatigue to better mimic performance in a sports environment to inform return-to-sport decisions.

LEVEL OF EVIDENCE

Level 1b- Therapy.