Younger patients are at increased risk for graft rupture and contralateral injury after anterior cruciate ligament reconstruction

Biomechanical Testing of Three Alternative Quadrupled Tendon Graft Constructs With Adjustable Loop Suspensory Fixation for Anterior Cruciate Ligament Reconstruction Compared With Four-Strand Grafts Fixed With Screws and Femoral Fixed Loop Devices

BACKGROUND

Quadrupled semitendinosus (ST) grafts for anterior cruciate ligament (ACL) reconstruction have advantages of greater graft diameter and gracilis (G) preservation compared with doubled ST-G grafts. However, a paucity of biomechanical data are available regarding different preparation techniques for these constructs.

PURPOSE

To biomechanically analyze 3 alternative tendon constructs fixed with adjustable suspensory fixation devices on the femur and tibia compared with a matched 4-strand construct fixed with a tibial screw and femoral fixed loop device.

STUDY DESIGN

Controlled laboratory study.

METHODS

Three alternative quadrupled tendon preparation techniques with suspensory fixation (grafts constructs A, B, and C) were compared with a 4-strand screw-fixed loop device construct (graft construct D) in matched diameter bovine tendon graft and porcine tibia models. Graft constructs were tested with a 3-stage cyclic loading protocol (1000 cycles in position control and 1000 cycles each from 10 to 250 N and from 10 to 400 N), followed by a pull to failure. In graft construct A, the graft ends were whipstitched and tied over the tibial button; in graft construct B, the graft ends functioned as pulleys; and in graft construct C, a continuous loop was created. Initial, dynamic, and total elongation, stiffness, and ultimate failure load were recorded.

RESULTS

Graft construct D had the highest initial (0.51 ± 0.29 mm) and total (3.53 ± 0.98 mm) elongation compared with the 3 quadrupled constructs ( P < .001 each). Graft construct B had lower total elongation (2.13 ± 0.31 mm) compared with graft construct A (2.40 ± 0.30 mm) ( P = .004) and graft construct C (2.53 ± 0.21 mm) ( P = .007). Graft construct C had a higher ultimate failure load (1097 ± 79 N) compared with graft construct A (988 ± 112 N) ( P = .001), graft construct B (973 ± 137 N) ( P = .022), and graft construct D, which had the lowest failure load (767 ± 182 N) ( P < .001).

CONCLUSION

The 3 quadrupled tendon suspensory fixation constructs exhibited small yet statistically significant biomechanical differences among each other. Constructs that used tibial screw fixation had lower ultimate failure load and higher total elongation compared with the quadrupled tendon constructs.

CLINICAL RELEVANCE

Total elongation for the screw fixation group was higher than the threshold of clinical failure, which may allow for graft construct elongation during the postoperative rehabilitation phase. Biomechanical properties of the 3 quadrupled tendon suspensory graft constructs may be clinically comparable, albeit statistically different.

Combined Anterior Cruciate and Anterolateral Ligament Reconstruction in the Professional Athlete: Clinical Outcomes From the Scientific Anterior Cruciate Ligament Network International Study Group in a Series of 70 Patients With a Minimum Follow-Up of 2 Years

PURPOSE

To evaluate clinical outcomes in professional athletes after combined anterior cruciate ligament (ACL) and anterolateral ligament (ALL) reconstruction at a minimum follow-up of 2 years.

METHODS

A retrospective analysis of prospectively collected data from the Scientific Anterior Cruciate Ligament Network International (SANTI) Study Group database was performed. All professional athletes who underwent primary combined ACL and ALL reconstruction between January 2011 and March 2016 were included. Patient assessment included physical examination, pre- and postoperative subjective and objective International Knee Documentation Committee (IKDC), Tegner activity scale, and Lysholm scores.

RESULTS

Seventy-two professional athletes underwent primary ACL and ALL reconstruction; 70 (97%) were available, with a mean follow-up of 3.9 years (range, 2-7). The preoperative side-to-side anteroposterior laxity difference was 7.1 ± 1.4 mm, and this decreased significantly after surgery to 0.4 ± 0.9 mm (P < .0001). Pivot-shift grade evolved from 16 grade I (22.8%) and 54 grade II or III (77.2%) preoperatively, to 66 absent pivot shift (94.3%) and 4 grade I (5.7; P < .001). By 1-year postoperatively, 60 athletes (85.7%) returned to professional sport, with a mean time interval of 7.9 months (range, 5-12). Preoperatively, the mean subjective IKDC was 56.1 ± 12.3, the Lysholm score was 48.4 ± 12.5, and the Tegner score was 9.3 ± 1. At final follow-up, the mean subjective IKDC was 90.5 ± 7.6 (P < .0001), the Lysholm score was 94.4 ± 7.5 (P < .0001), and the Tegner score was 8.8 ± 1.5 (P < .004). The objective IKDC evolved from 39 grade C (55.7%) and 31 grade D (44.3%) preoperatively to 65 grade A (92.9%) and 5 grade B (7.1%) (P < .0001). Eleven Patients (15,7%) underwent a subsequent ipsilateral reoperation including 4 (5.7%) revision ACL reconstructions. The risk of graft rupture was significantly higher in female patients (13.6% vs 2.1% in male patients; P = .048).

CONCLUSIONS

Combined ACL and ALL reconstruction is associated with excellent outcomes in professional athletes with respect to graft rupture rates, return to sport, knee stability, and reoperation rates after injury.

LEVEL OF EVIDENCE

Level IV, case series.

Partial meniscectomy adversely affects return-to-sport outcome after anatomical double-bundle anterior cruciate ligament reconstruction

PURPOSE

The purposes of this study were to determine whether the partial meniscectomy combined with ACL reconstruction affect the postoperative return-to-sport and to identify if partial meniscectomy has an influence on the graft failure following an anatomical double-bundle ACL reconstruction case.

METHODS

A retrospective cohort study including 426 primary double bundle ACL reconstruction cases. There were 206 males and 220 females, median age of 28.4 years, median BMI of 23.0, median preinjury Tegner score of 7.0 and median follow-up period after surgery of 24.0 months. Patients with less than 12 months of follow-up, revision surgery, multi-ligaments injury, previous contralateral knee ligaments injury and postoperative infection cases were excluded. Furthermore, patients who had meniscal repair were excluded in order to compare the outcomes between patients who had intact menisci and those who underwent partial meniscectomy. There were 227 patients with intact menisci (group A) and 199 patients with partial meniscectomy (group B). The median age was younger and the preoperative Tegner score was higher in group A. The patients in group B were subcategorized as the site of partial meniscectomy, including medial (group C), lateral (group D) and bicompartmental (group E) meniscectomy. There were 74, 94, and 31 patients in group C, D, and E, respectively. Return-to-sport (running and sport phase) and graft failure were included in our primary outcomes, and functional outcome as Lysholm knee scores was included in secondary outcome.

RESULTS

The rate of return to running phase and sport phase were 91% (387/426) and 76% (303/399), the mean time taken to return to running and sport phase were 5.7 months and 11.1 months, respectively. There was significant difference in the returning to sport phase between group A and B (p = 0.01), and between group A and D/E subgroups (p = 0.007). There were fourteen graft failures (3.5%) in total. In addition, 9 and 5 graft failures in group A and B, respectively. Of the 5 graft failures in group B, 2 and 3 graft failures in group C and D, respectively. There was no significant difference of the graft failure ratio among the groups.

CONCLUSION

Our study demonstrates that partial meniscectomy has an adverse effect on the return to sport phase following the anatomical double-bundle ACL reconstruction. Therefore, greater postoperative care would be needed to return to sport with partial meniscectomy in ACL reconstruction cases. On the contrary, partial meniscectomy is not considered to be the risk factor for graft failure at short-term follow-up.

LEVEL OF EVIDENCE

Case-control study, Level III.

Psychological Readiness to Return to Sport Is Associated With Second Anterior Cruciate Ligament Injuries

BACKGROUND

Psychological responses after anterior cruciate ligament (ACL) injury and ACL reconstruction (ACLR) have been identified as predictors of return to sport but have not been investigated in relation to further injury.

PURPOSE/HYPOTHESIS

To determine whether psychological readiness to return to sport is associated with second ACL injury. It was hypothesized a priori that at both preoperative and 12-month postoperative time points, patients who sustained a second ACL injury would have lower psychological readiness than patients who did not have a second injury.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Patients who had a primary ACLR procedure between June 2014 and June 2016 completed the ACL-Return to Sport after Injury (ACL-RSI) (short version) scale before their ACLR and repeated the scale at 12 months after surgery to assess psychological readiness to return to sport. Patients were followed for a minimum of 2 years (range, 2-4 years) after surgery to determine further injury. The primary outcome was the relationship between ACL-RSI scores and the incidence of second ACL injury.

RESULTS

In 329 patients who returned to sport after ACLR, 52 (16%) sustained a second ACL injury. No difference in psychological readiness was observed at the preoperative time point, but patients who sustained a second injury trended toward lower psychological readiness at 12 months compared with noninjured patients (60.9 vs 67.2 points; P = .11). Younger (≤20 years) patients with injury had significantly lower psychological readiness to return to sport than young noninjured patients (60.8 vs 71.5 points; P = .02), but no difference was found in older patients (60.9 vs 64.6 points; P = .58). In younger patients, receiver operating characteristic curve analysis revealed a cutoff score of 76.7 points with 90% sensitivity to identify younger patients who sustained a second ACL injury.

CONCLUSION

Younger patients with lower psychological readiness are at higher risk for a second ACL injury after return to sport.

Return to Sport and Reoperation Rates in Patients Under the Age of 20 After Primary Anterior Cruciate Ligament Reconstruction: Risk Profile Comparing 3 Patient Groups Predicated Upon Skeletal Age

BACKGROUND

With sports specialization and level of competition on the rise, anterior cruciate ligament reconstruction (ACLR) in athletes under the age of 20 has increased significantly in recent years. Reports have demonstrated that the revision ACLR rate is higher and return to sport (RTS) rate is lower in this population.

PURPOSE

To evaluate the 2-year clinical outcomes of 3 cohorts of primary ACLR in pediatric and adolescent athletes under the age of 20 based on skeletal age with a focus on RTS and the incidence of second surgery.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

This is a prospective evaluation of 324 athletes younger than 20 years of age who underwent ACLR with minimum 2-year follow-up. The surgical technique was selected predicated on skeletal age, which includes the all-epiphyseal technique with hamstring autograft in the youngest cohort in elementary and middle school (group 1), the partial transphyseal and complete transphyseal with hamstring autograft performed for athletes in the middle cohort (group 2), and bone-tendon-bone autograft in the skeletally mature high school athletes (group 3).

RESULTS

The mean chronological age of the entire cohort was 15 years (range, 8-19 years) with 55% males. The 3 cohorts included 49 patients (15%) in group 1 (mean age, 12 years), 66 (20%) in group 2 (mean age, 14.3 years), and 209 (65%) in group 3 (mean age, 16.2 years). Group 2 athletes had a significantly higher revision ACLR rate (20%) compared with group 1 (6%; P = .039) and group 3 (6%; P = .001). Similarly, group 2 athletes had significantly lower RTS rates (85%) compared with group 1 (100%) and group 3 (94%).

CONCLUSION

The rate of revision ACLR was significantly higher and the RTS rates significantly lower in group 2 compared with groups 1 and 3. This age-related risk profile may be used to counsel athletes and parents preoperatively regarding the expectations of surgery with respect to revision ACLR and RTS rates.

Knee strength, hop performance and self-efficacy at 4 months are associated with symmetrical knee muscle function in young athletes 1 year after an anterior cruciate ligament reconstruction

Objectives

We investigated whether patient demographics, 4-month patient-reported outcomes (PRO) and muscle function predicted young athletes regaining symmetrical muscle function in five tests of muscle function 1 year after ACL reconstruction.

Methods

We extracted data on patient demographics, PROs and the results of five tests of muscle function from a rehabilitation-specific register. Athletes were 15–30 years of age, involved in knee-strenuous sport and had undergone a primary ACL reconstruction. The primary outcome was achieving a Limb Symmetry Index of ≥90% for the battery of tests 1 year after ACL reconstruction. Patient demographics, muscle-function data and results for PROs at the 4-month follow-up were analysed.

Results

In all, 237 athletes (59% female; mean age 22±4 years) were included in the study. One year after ACL reconstruction, 26% (62/237) of the included athletes had achieved symmetrical muscle function. Univariable analysis showed that symmetrical muscle function was associated with present self-efficacy, OR 1.28 (95% CI 1.04 to 1.58, p=0.011), knee-extension strength, OR 1.73 (95% CI 1.28 to 2.34), knee-flexion strength, OR 1.39 (95% CI 1.07 to 1.81), vertical hop, OR 1.77 (95% CI 1.27 to 2.45), single-leg hop for distance, OR 1.98 (95% CI 1.24 to 3.17) and side hop, OR 1.64 (95% CI 1.15 to 2.33).

Conclusion

Symmetrical knee-extension and knee-flexion strength, a more symmetrical hop performance and higher present self-efficacy at an early stage all increased the odds of achieving symmetrical muscle function in young athletes 1 year after ACL reconstruction.

Low Rates of Return to Preinjury Sport After Bilateral Anterior Cruciate Ligament Reconstruction

BACKGROUND

Patients with bilateral anterior cruciate ligament (ACL) injuries tend to report worse results in terms of knee function and quality of life as compared with those with unilateral injury. There are limited data regarding return to preinjury sport in this group.

PURPOSE

To report return-to-sport rates for patients who had bilateral ACL reconstruction and to compare outcomes according to age and sex.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 107 patients (62 male, 45 female) who underwent primary ACL reconstruction surgery to both knees completed a detailed sports activity survey at a mean 5-year follow-up (range, 2.5-10 years). Follow-up also included the International Knee Documentation Committee subjective form, Marx Activity Scale, and Knee injury and Osteoarthritis Outcome Score-Quality of Life subscale. Rates of return to preinjury levels of sport were calculated for the whole cohort, and for further analysis, the group was divided according to age (<25 vs ≥25 years), sex, and time between the reconstruction procedures (<3 vs ≥3 years).

RESULTS

The rate of return to preinjury sport after bilateral ACL reconstruction was 40% (95% CI, 31%-50%), as compared with an 83% (95% CI, 74%-88%) return rate after the first reconstruction procedure. Although not statistically significant, return rates were higher for male versus female patients (47% vs 31%) and older versus younger patients (45% vs 31%). Of those who returned to their preinjury levels of sport after the second reconstruction, 72% thought that they could perform as well as before their ACL injuries. In contrast, only 20% thought that they could perform as well if they returned to a lower level. Fear of reinjury was the most common reason cited for failure to return to sport after the second reconstruction. Patient-reported outcome scores were higher for those who returned to their preinjury levels of sport but did not differ for sex and age.

CONCLUSION

Return-to-sport rates drop markedly after a second (contralateral) ACL reconstruction, with less than half of the investigated cohort returning to its preinjury level of sport. Return-to-sport outcomes are less than ideal for patients who have ACL reconstruction surgery to both knees.

A research update on the state of play for return to sport after anterior cruciate ligament reconstruction

Most athletes who undergo anterior cruciate ligament (ACL) reconstruction surgery plan to return to some level of sporting activity. However, rates of return to pre-injury sport are often less than might be expected and many factors influence whether individuals return to sport after this surgery. They include surgical and rehabilitation factors as well as social, psychological and demographic characteristics. The fate of the younger athlete who sustains an ACL injury is a topic that has received recent attention due to accumulating evidence that younger athletes are at considerable risk for not only one, but multiple ACL injuries. Little is known about how to determine when it is safe to return to sport following ACL reconstruction or how to predict whether an athlete will be able to successfully return. The notion that a set of return to sport criteria can be applied to reduce the risk of further injury has become popular with many different criteria proposed. Another risk of returning to sport following ACL reconstruction is that of sustaining injury to the menisci or articular surfaces, which may in turn increase the risk of developing osteoarthritis. Although there is some evidence that ACL reconstruction reduces the risk of osteoarthritis there is stronger evidence that it does little to protect the knee from long term degeneration. Therefore, it should be recognized that return to sport following ACL reconstruction is associated with a risk of further injury and potential development of osteoarthritis.Level of evidence: V.

Systematic Selection of Key Logistic Regression Variables for Risk Prediction Analyses: A Five-Factor Maximum Model

GENERAL AND CRITICAL REVIEW FORMAT

The evolution of clinical practice and medical technology has yielded an increasing number of clinical measures and tests to assess a patient's progression and return to sport readiness after injury. The plethora of available tests may be burdensome to clinicians in the absence of evidence that demonstrates the utility of a given measurement.

OBJECTIVE

Thus, there is a critical need to identify a discrete number of metrics to capture during clinical assessment to effectively and concisely guide patient care.

DATA SOURCES

The data sources included Pubmed and PMC Pubmed Central articles on the topic. Therefore, we present a systematic approach to injury risk analyses and how this concept may be used in algorithms for risk analyses for primary anterior cruciate ligament (ACL) injury in healthy athletes and patients after ACL reconstruction.

MAIN RESULTS

In this article, we present the five-factor maximum model, which states that in any predictive model, a maximum of 5 variables will contribute in a meaningful manner to any risk factor analysis.

CONCLUSIONS

We demonstrate how this model already exists for prevention of primary ACL injury, how this model may guide development of the second ACL injury risk analysis, and how the five-factor maximum model may be applied across the injury spectrum for development of the injury risk analysis.

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.

Anterior cruciate ligament repair with Independent Suture Tape Reinforcement: a case series with 2-year follow-up

PURPOSE

The treatment of acute anterior cruciate ligament (ACL) ruptures with a repair technique has recently regained interest. A novel ACL repair technique was described using Independent Suture Tape Reinforcement with 2-year follow-up results.

METHODS

Forty-two consecutive patients with an acute ACL rupture undergoing repair using this technique were followed up for a minimum of 2 years. Patients with mid-substance, distal ACL ruptures, poor ACL tissue quality or retracted ACL remnants as well as patients with multi-ligament injuries were excluded. Knee Injury and Osteoarthritis Outcome Score (KOOS), Visual Analogue Pain Scale (VAS-pain), Veterans RAND 12 Item Health Survey (VR-12) and the Marx Activity scale were collected by online questionnaires. Two-year postoperative patients were asked by telephone if they had experienced a rerupture.

RESULTS

All the KOOS subscales improved significantly in comparison to the preoperative score. The largest improvement of all scores was seen at 3 months postoperatively which is significant in all cases. The KOOS sport and recreation showed a meaningful change and the largest improvement of the KOOS subscales at 3 months postoperatively, as well as the highest total improvement at 1 year postoperatively compared to preoperatively. The VAS-pain and VR-12 physical score improved significantly, however the Marx activity scale decreased significantly in comparison to preoperative scores. Two patients reported a rerupture (4.8%, CI 1.7-11.2%).

CONCLUSIONS

This is the first case series that described the 2-year follow-up results of patients with an acute, proximal ACL rupture, treated with the Independent Suture Tape Reinforcement repair technique. A meaningful KOOS sport and recreation change and significant improvements in the KOOS, VAS-pain and VR-12 physical scores as well as a significant decrease of the Marx activity scale in comparison to preoperative scores are demonstrated. Two of the 42 patients (4.8%) reported an ACL rerupture. Repair with this technique could be clinically relevant as a treatment option for patients with an acute, proximal ACL rupture which is not retracted and of good tissue quality.

LEVEL OF EVIDENCE

IV.

Improved results of ACL primary repair in one-part tears with intact synovial coverage

PURPOSE

It was the aim to assess the influence of synovial sheath disruption on early failure of primary anterior cruciate ligament (ACL) repair. It was hypothesized that more-part ACL tears with disruption of the synovial sheath are associated with a higher risk of failure after primary ACL repair.

METHODS

A cohort study was conducted comprising patients with primal ACL tears undergoing primary ACL repair and dynamic intraligamentary stabilization (DIS). The patients were stratified into three groups: A-one-part rupture with intact synovial membrane (n = 50), B-two-part ruptures resultant to separation of the ACL into two main bundles with synovial membrane tearing (n = 52) and C-more parts involving multilacerated ruptures with membrane disruption (n = 22). Failure was defined as a retear or residual laxity (anterior posterior translation > 5 mm compared to healthy knee). Adjustment for potential risk factors was performed using a multivariate logistic-regression model.

RESULTS

The overall failure rate was 17.7% throughout the mean follow-up period of 2.3 ± 0.8 years. The failure rate in patients with one-part ACL tears with an intact synovial membrane was 4% (n = 2) (Group A), which was significantly lower than the failure rates in groups B and C, 26.9% (n = 14) (p = 0.001) and 27.3% (n = 6) (p = 0.003), respectively. Disruption of the synovial sheath in two- or more-part tears was identified as an independent factor influencing treatment failure in primary ACL repair (OR 8.9; 95% CI 2.0-40.0).

CONCLUSION

The integrity of the ACL bundles and synovial sheath is a factor that influences the success of ACL repair. This needs to be considered intra-operatively when deciding about repair.

LEVEL OF EVIDENCE

IV.

Fifteen-Year Audit of Anterior Cruciate Ligament Reconstructions in the Australian Football League From 1999 to 2013: Return to Play and Subsequent ACL Injury

BACKGROUND

Anterior cruciate ligament (ACL) injury has been a major cause of missed game time among Australian Football League (AFL) players. Return to play after ACL reconstruction is not always achieved, even among elite athletes. The rate of subsequent ACL injury in the AFL from 1990 to 2000 was high as compared with that of other elite sports.

PURPOSE

To determine the rates of return to play and subsequent ACL injury after ACL reconstruction among AFL players from 1999 to 2013 and to explore factors associated with differing rates of return to play and subsequent ACL injury.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 158 AFL players who underwent ACL reconstruction were identified from a prospectively maintained registry of AFL player injuries. Further data were gathered from official playing statistics, surgical records, and structured phone interviews.

RESULTS

The rate of return to play after an initial ACL injury was 77% (121 of 158 players). Greater preinjury playing experience and earlier selection in the AFL draft were associated with higher rates of return to play. The rate of subsequent ACL injury to either knee was 30% (48 of 158 players) and was especially high among players aged <21 years (23 of 46 players, 50%). After subsequent ACL injury, 34 of 48 players (71%) returned to play. In primary ACL reconstruction, the use of Ligament Augmentation and Reconstruction System grafts resulted in a faster return to play ( P = .001) but had a higher risk of subsequent revision reconstruction (risk ratio = 2.8, P = .048). Family history of ACL injury was associated with an increased risk of subsequent contralateral ACL injury (risk ratio = 3.8, P = .002).

CONCLUSION

Most AFL players who underwent ACL reconstruction returned to play at least 1 AFL match. The high rate of subsequent ACL injury among AFL players demonstrates the highly demanding nature of Australian football, particularly at the elite level. The risk factors for subsequent ACL injury should be considered carefully when treatment and rehabilitation decisions are made for these high-demand athletes.

Lower Limb Biomechanics During Single-Leg Landings Following Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-Analysis

BACKGROUND

Anterior cruciate ligament reconstruction (ACLR) may not restore lower limb biomechanics during single-limb landings.

OBJECTIVES

Our objective was to identify and evaluate differences in lower limb biomechanics during high-demand single-limb landings between the ACLR limb and the contralateral limb and healthy control participants.

METHODS

A systematic review of the literature was conducted using six electronic databases searched until April 2017 for published peer-reviewed studies that investigated lower limb biomechanics on the ACLR limb compared with either the contralateral limb or those of control participants. Meta-analysis with standardized mean differences (SMD) were performed for peak angles and moments (hip, knee and ankle joints) in the sagittal plane during single-limb landing tasks.

RESULTS

A total of 35 studies met inclusion criteria. Four different single-leg landing tasks were identified: forward hop (n = 24 studies), landing from a height (n = 9 studies), vertical hop (n = 4 studies), and diagonal leap (n = 1 study). A reduced peak knee flexion angle was found in the ACLR limb compared with the contralateral limb during a forward hop landing task (SMD - 0.39; 95% confidence interval [CI] - 0.59 to - 0.18) and compared with a control group (SMD between - 1.01 and - 0.45) for all three reported single-leg landing tasks: forward hop, landing from a height, and diagonal leap. Similarly, a reduced peak knee internal extensor moment was found in the ACLR limb compared with the contralateral limb for all three reported landing tasks: forward hop, landing from a height, vertical hop (SMD between - 1.43 and - 0.53), and in two of three landing tasks when compared with a control group (SMD between - 1.2 and - 0.52). No significant differences in peak flexion (hip and ankle) angle or peak (hip and ankle) internal extensor moment were found in the ACLR limb compared with both the contralateral limb and a control group.

CONCLUSIONS

Participants performed single-limb landings on the ACLR limb with reductions in peak sagittal knee kinematics as well as peak joint moments compared with both the contralateral limb and a control group. Stiffer single-leg landings potentially expose the knee joint to higher forces, which may increase risk of injury. Clinical testing after ACLR surgery should explore movement quality as well as performance of functional tasks.

LEVEL OF EVIDENCE

Case-control, IV.

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.

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.

Effects of Unilateral Electroacupuncture on Bilateral Proprioception in a Unilateral Anterior Cruciate Ligament Injury Model

BACKGROUND Anterior cruciate ligament (ACL) injury can cause knee proprioception degeneration, on which the electroacupuncture (EA) treatment has a definite effect. However, it is still not clear whether conducting EA intervention on the injured side can promote bilateral proprioception recovery. MATERIAL AND METHODS We randomly selected 6 of 9 normal cynomolgus monkeys to develop unilateral ACL injury models via arthroscopy. All knees were divided into 5 groups: the normal control (NC) group, injured side of blank model (ISBM) group, contralateral side of blank model (CSBM) group, injured side of EA (ISE) group, and contralateral side of EA (CSE) group. Ten days after modeling, the monkeys in the EA group were treated with EA daily for 6 weeks at the acupoints. At 6 weeks, the 5 groups were examined by electrophysiology (SEPs and MCV). The ACL was separated to conduct the gold chloride staining for morphology observation and count the number of total and variant proprioceptors. RESULTS At 6 weeks, the latent period of the SEPs and MCV and the number of variant proprioceptors in the blank model group and the EA group were increased compared with the NC group, while the amplitude and the number of total proprioceptors were decreased. The changes in the ISBM and CSBM group were more remarkable than in the ISE and CSE group. All differences were statistically significant (P<0.05). CONCLUSIONS Unilateral ACL injury leads to bilateral proprioception degeneration, and the unilateral knee EA intervention can aid bilateral proprioception recovery.

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.

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.

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.

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.

Factors Associated With Psychological Readiness to Return to Sport After Anterior Cruciate Ligament Reconstruction Surgery

BACKGROUND

Anterior cruciate ligament (ACL) injury has a significant psychological effect, and a negative psychological state is a commonly cited reason for a reduction or cessation of sports participation after ACL reconstruction (ACLR) surgery.

PURPOSE

To identify factors that contribute to an athlete's psychological readiness to return to sport (RTS) after ACLR.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A cohort of 635 athletes (389 male, 246 female) who underwent ACLR and had been cleared to RTS completed the Anterior Cruciate Ligament-Return to Sport After Injury (ACL-RSI) scale at an average 12 months (range, 11-24 months) after surgery. Demographics (age, sex), sporting outcomes (preinjury frequency), surgical timing (injury to surgery interval), clinical factors (laxity), functional measures (single-limb hop symmetry), and symptoms of pain and function (International Knee Documentation Committee subjective) were also taken, and univariate and multiple regression models were used to determine the association between these and the psychological readiness of the athlete to RTS (ACL-RSI scores). Data for the entire cohort were initially analyzed; then, patients were grouped according to whether they had returned to competitive sport, and the analysis repeated for each group (return/nonreturn).

RESULTS

Univariate analysis for the entire group showed that all of the following had a positive effect on psychological readiness: male sex (β = 5.8; 95% CI, 2-10), younger age (β = -0.2; 95% CI, -0.4 to 0.01), a shorter interval between injury and surgery (β = -0.1; 95% CI, -0.1 to -0.02), a higher frequency of preinjury sport participation (β = 5.4; 95% CI, 2-9), greater limb symmetry (β = 0.5; 95% CI, 0.3-0.6), and higher subjective knee scores (β = 1.3; 95% CI, 1.1-1.4). In the multivariate model, subjective knee scores and age significantly accounted for 37% of the variance in psychological readiness ( r² = 0.37, P < .0001). The only difference between the groups who had and had not returned to sport was that female sex was a significant contributor for the nonreturn group.

CONCLUSION

Self-reported symptoms and function were most associated with psychological readiness to RTS after ACLR surgery. Male patients who participated frequently in sport before ACL injury had higher psychological readiness. Conversely, female patients had a more negative outlook and may therefore benefit more from interventions designed to facilitate a smooth transition back to sport.

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.

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.

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.

Patient and surgical characteristics that affect revision risk in dynamic intraligamentary stabilization of the anterior cruciate ligament

PURPOSE

Failure of dynamic intraligamentary stabilization (DIS) that requires revision surgery of the anterior cruciate ligament (ACL) has not been studied. The aim of this study was to investigate the incidence of revision ACL surgery, and the patient characteristics and surgery-related factors that are associated with an increased risk of ACL revision after DIS.

METHODS

This study analysed a prospective, consecutively documented single-centre case series using standardized case report forms over a 2.5-year follow-up period. The primary endpoint was revision ACL surgery. We used Kaplan-Meier analysis to examine the revision-free survival time, and a multiple logistic regression model of potential risk factors including age, sex, BMI, smoking status, previous contralateral ACL injury, Tegner activity score, interval to surgery, rupture pattern, hardware removal, and postoperative side-to-side difference in knee laxity. Relative risk was calculated for subgroups of significant risk factors.

RESULTS

In total, 381 patients (195 male) with a mean age of 33 ± 12 years were included in the analysis. The incidence of revision ACL surgery was 30/381 (7.9%). Younger age (p = 0.001), higher Tegner activity score (p = 0.003), and increased knee laxity (p = 0.015) were significantly associated with revision ACL surgery. The increased relative risk for patients who were less than 24 years old, participated in activities at a Tegner level >5 points, or had >2 mm of side-to-side difference in knee laxity was 1.6, 3.7, and 2.3, respectively.

CONCLUSION

Young age, high level of sport activity, and high knee laxity observed in follow-up examinations increased the likelihood for revision surgery after DIS. Patients undergoing DIS should be informed of their potentially increased risk for therapy failure and carefully monitored during recovery.

LEVEL OF EVIDENCE

Case series, Level IV.

A Novel Mass-Spring-Damper Model Analysis to Identify Landing Deficits in Athletes Returning to Sport After Anterior Cruciate Ligament Reconstruction

Schneider, DK, Gokeler, A, Otten, E, Ford, KR, Hewett, TE, Divine, JG, Colosimo, AJ, Heidt, RS, and Myer, GD. A Novel mass-spring-damper model analysis to identify landing deficits in athletes returning to sport after anterior cruciate ligament reconstruction. J Strength Cond Res 31(9): 2590-2598, 2017-A mass-spring-damper (MSD) model may serve as an extension of biomechanical data from 3-dimensional motion analysis and epidemiological data which helps to delineate populations at risk for anterior cruciate ligament (ACL) injuries. The purpose of this study was to evaluate such a model. Thirty-six ACL reconstruction (ACLR) group subjects and 67 controls (CTRL) completed single-leg drop landing and single-leg broad jump tasks. Landing ground reaction force data were collected and analyzed with an MSD model. Medians, interquartile ranges, and limb symmetry indices (LSIs) were calculated and comparisons were made within and between groups. During a single-leg drop landing, the ACLR group had a lower spring LSI than the CTRL group (p = 0.015) and landed with decreased stiffness in the involved limb relative to the uninvolved limb (p = 0.021). The ACLR group also had an increased damping LSI relative to the CTRL group (p = 0.045). The ACLR subjects landed with increased stiffness (p = 0.006) and decreased damping (p = 0.003) in their involved limbs compared to CTRL subjects' nondominant limbs. During a single-leg forward broad jump, the ACLR group had a greater spring LSI value than the CTRL group (p = 0.045). The CTRL group also recorded decreased damping values in their nondominant limbs compared with the involved limbs of the ACLR group (p = 0.046). Athletes who have undergone ACLR display different lower-limb dynamics than healthy controls, according to an MSD model. Quadriceps dominance and leg dominance are components of ACLR athletes' landing strategies and may be identified with an MSD model and addressed during rehabilitation.

What's New in Pediatric and Adolescent Anterior Cruciate Ligament Injuries?

BACKGROUND

Anterior cruciate ligament (ACL) tears in children and adolescent patients are being diagnosed and treated at an ever-increasing rates. We performed a review of recent literature regarding care of children and adolescent athletes with an ACL injury.

METHODS

PubMed database was searched for all papers related to treatment of children and adolescents with ACL injuries from October 1, 2012 to September 30, 2015, yielding 114 publications.

RESULTS

A total of 59 papers were found to have contributed important new findings. Papers were selected based on new findings in the following categories: epidemiology, anatomy, risk factors, sex disparity, prevention, surgical outcomes, timing and associated pathologies, and rehabilitation and return to sport.

CONCLUSIONS

Pediatric ACL injuries continue to rise and there are multiple surgical procedures that restore clinical function with good outcomes. Early surgical treatment is favored to prevent concomitant articular injuries. Early return to play can increase risk of reinjury and should be met with caution in this age group. Prevention strategies should be further studied and implemented in hopes of decreasing the incidence of this injury and the long-term potential damage.

LEVEL OF EVIDENCE

Level 4-titerature review.

Is Treatment of Segond Fracture Necessary With Combined Anterior Cruciate Ligament Reconstruction?

BACKGROUND

There is a paucity of clinical information to guide the treatment of a combined anterior cruciate ligament (ACL) tear and Segond fracture.

PURPOSE

To compare clinical outcomes, graft failure rates, and activity levels between patients undergoing ACL reconstruction (ACLR) with and without an untreated Segond fracture at a minimum 2-year follow-up.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

This study included a group of patients with a combined ACL tear/untreated Segond fracture that was matched based on age, sex, body mass index, and graft type to a control group of patients with an ACL tear and no Segond fracture. All patients were treated with ACLR alone between the years of 2000 and 2015. The diagnosis of a Segond fracture, or bony avulsion of the anterolateral complex, was made by radiographic analysis. Data regarding the initial injury, surgical intervention, and physical examination findings were recorded. Clinical and functional outcomes were obtained using physical examination results, International Knee Documentation Committee (IKDC) subjective scores, and Tegner activity levels.

RESULTS

Twenty patients (16 male, 4 female) with a combined ACL tear/untreated Segond fracture with a mean age of 26.3 years (range, 13-44 years) were matched to a control group of 40 patients (32 male, 8 female) with an ACL tear and no Segond fracture with a mean age of 26.4 years (range, 13-47 years). The study group was followed for a mean of 59.1 months (range, 24-180 months) and the control group for a mean of 55.5 months (range, 24-120 months). The mean IKDC score was 86.5 (range, 54-100) for the study group compared with 93.0 (range, 54-100) for the control group ( P = .03). The graft rupture rate was 10% for both groups ( P = .97). The mean time to rupture was 33.0 months (range, 21-45 months) in the study group and 63.5 months (range, 39-88 months) in the control group ( P = .24). Patients in the study group had significantly more anteroposterior instability by preoperative Lachman testing than those in the control group (control group: 0 normal, 3 grade 1+, 37 grade 2+, 0 grade 3+; study group: 0 normal, 1 grade 1+, 10 grade 2+, 9 grade 3+; P = .0001). There was no significant difference between the 2 groups in regard to postoperative Lachman testing (control group: 35 normal, 3 grade 1+, 2 grade 2+, 0 grade 3+; study group: 17 normal, 3 grade 1+, 0 grade 2+, 0 grade 3+; P = .31). Patients in the study group had significantly more instability by preoperative pivot-shift testing than those in the control group (control group: 0 normal, 7 grade 1+, 33 grade 2+, 0 grade 3+; study group: 1 normal, 1 grade 1+, 11 grade 2+, 7 grade 3+; P = .0003). No significant difference was found between the 2 groups for postoperative pivot-shift testing (control group: 36 normal, 2 grade 1+, 2 grade 2+, 0 grade 3+; study group: 18 normal, 1 grade 1+, 1 grade 2+, 0 grade 3+; P = .61) or final Tegner activity level (median, 6).

CONCLUSION

At midterm follow-up, patients undergoing ACLR with and without a Segond fracture had similar pivot-shift test results, graft failure rates, and activity levels. The IKDC score was statistically worse in the patients with a combined ACL tear/untreated Segond fracture, but the difference was less than the minimal clinically important difference for the IKDC score. These findings suggest that patients with a combined ACL tear/untreated Segond fracture can have comparable outcomes to patients with an ACL tear and no Segond fracture when treated with ACLR alone.

Challenges in the Management of Anterior Cruciate Ligament Ruptures in Skeletally Immature Patients

Although initially considered rare, anterior cruciate ligament (ACL) ruptures in pediatric patients recently have increased substantially as a result of greater awareness of the injury and increased participation in youth sports. Although pediatric patients with an ACL injury and a clinically stable joint may handle the injury well and return to sports activity without requiring surgical reconstruction, young, active patients with an ACL rupture and an unstable joint may be good candidates for ACL reconstruction to prevent ongoing instability and additional joint damage. ACL reconstruction techniques have been developed to prevent physeal injury in skeletally immature patients. The surgical treatment of skeletally immature patients with an ACL rupture may differ from that of adults with an ACL rupture and presents unique challenges with regard to reconstruction technique selection, graft preparation, rehabilitation, and return to sports activity. Orthopaedic surgeons should understand various physeal-sparing ACL reconstruction techniques and the general challenges associated with the surgical management of ACL ruptures in pediatric patients.

Role of anterolateral reconstruction in patients undergoing anterior cruciate ligament reconstruction

There is renewed interest in anterolateral reconstruction (ALR) for patients undergoing anterior cruciate ligament (ACL) reconstruction. This is the result of isolated ACL reconstruction and double-bundle reconstruction providing inadequate control over the pivot shift, and recent anatomical and biomechanical studies on the anterolateral ligament (ALL) and its role in the knee's rotational stability. From a technical point of view, ALR can be performed either as a continuity of the intra-articular ACL reconstruction or an independent procedure. The typical peripheral grafts (gracilis and semitendinosus tendons, iliotibial band) can be used. The femoral tunnel must be posterior and proximal to the lateral epicondyle, and the tibial tunnel on a line joining Gerdy's tubercle with the ALL's tibial insertion. Tensioning and fixation are done with the knee near full extension and the tibia in neutral rotation. The ALR complication rate reported in older studies (pain, hematoma, scar damage) has been reduced. Relative to isolated ACL reconstruction, ALR does not alter the infection or stiffness rate, and it reduces the re-injury rate and secondary meniscal damage rate. Analysis of the literature has not shown an increased rate of osteoarthritis after ALR. The objective and functional outcomes are equal to those after isolated ACL reconstruction. Control over rotation is improved by adding ALR and the return to pivot sports appears to be more successful. While the indications must still be refined, ALR can be proposed to young patients undergoing ACL reconstruction who participate in high-intensity pivot sports, have a high-grade pivot shift or who have a failed ACL reconstruction.

Young athletes return too early to knee-strenuous sport, without acceptable knee function after anterior cruciate ligament reconstruction

PURPOSE

The purpose of this study was to evaluate the return to knee-strenuous sport rate, muscle function and subjective knee function among adolescent patients (15-20 years of age) and adult patients (21-30 years of age) 8 and 12 months, respectively, after anterior cruciate ligament (ACL) reconstruction. It was hypothesised that no differences in outcome would be found between age groups at 8 or 12 months after ACL reconstruction.

METHODS

Cross-sectional data from five tests of muscle function, from the Knee injury and Osteoarthritis Outcome Score (KOOS) and the Tegner Activity Scale (Tegner), performed at 8 and 12 months after a primary ACL reconstruction, were extracted from a rehabilitation outcome register. A total of 270 (51% women) athletes, aged 15-30 years, who were all involved in knee-strenuous sport prior the injury, were included at 8 months after ACL reconstruction. At 12 months 203 (51% women) were included. The return to knee-strenuous-sport rates and the rate of achieving a limb symmetry index of ≥ 90% in all five tests of muscle function, defined as recovery of muscle function, and subjective knee function scores, as measured with the KOOS, were compared between age groups.

RESULTS

The adolescent patients had a higher (50%) return to knee-strenuous sport rate compared with the adult patients (38%) 8 months after ACL reconstruction (p = 0.04). At the 12-month follow-up, no difference was found between the age groups; 74 and 63%, respectively. At the 8-month follow-up, 29% of the patients, in both age groups, who had returned to sport had recovered their muscle function in all five tests of muscle function. At the 12-month follow-up, the corresponding results were 20% for the adolescents and 28% for the adult patients. No difference in mean KOOS scores was found between the age groups at 8 or at 12 months after ACL reconstruction.

CONCLUSION

The majority of young athletes make an early return to knee-strenuous sport after a primary ACL reconstruction, without recovering their muscle function. To set realistic expectations, clinicians are recommended to ensure that young athletes receive information about not to return before muscle function is recovered and that this may take longer time than 12 months.

LEVEL OF EVIDENCE

II.

"I never made it to the pros…" Return to sport and becoming an elite athlete after pediatric and adolescent anterior cruciate ligament injury-Current evidence and future directions

The management of anterior cruciate ligament (ACL) injuries in the skeletally immature and adolescent patient remains an area of controversy in sports medicine. This study, therefore, summarizes and discusses the current evidence related to treating pediatric and adolescent patients who sustain an ACL injury. The current literature identifies a trend towards ACL reconstruction as the preferred treatment option for ACL injuries in the young, largely justified by the risk of further structural damage to the knee joint. Worryingly, a second ACL injury is all too common in the younger population, where almost one in every three to four young patients who sustain an ACL injury and return to high-risk pivoting sport will go on to sustain another ACL injury. The clinical experience of these patients emphasizes the rarity of an athlete who makes it to elite level after a pediatric or adolescent ACL injury, with or without reconstruction. If these patients are unable to make it to an elite level of sport, treatment should possibly be modified to take account of the risks associated with returning to pivoting and strenuous sport. The surveillance of young athletes may be beneficial when it comes to reducing injuries. Further research is crucial to better understand specific risk factors in the young and to establish independent structures to allow for unbiased decision-making for a safe return to sport after ACL injury. Level of evidence V.

Altered movement during single leg hop test after ACL reconstruction: implications to incorporate 2-D video movement analysis for hop tests

PURPOSE

There is a lack of objective factors which can be used in guiding the return to sport (RTS) decision after an anterior cruciate ligament reconstruction (ACLR). The purpose of the current study was to conduct qualitative analysis of the single leg hop (SLH) in patients after ACLR with a simple and clinical friendly method and to compare the possible difference in movement pattern between male and female patients.

METHODS

Sixty-five patients performed the single leg hop (SLH) test at 6.8 ± 1.0 months following isolated ACLR. Digital video camcorders recorded frontal and sagittal plane views of the patient performing the SLH. Knee flexion at initial contact (IC), peak knee flexion, knee flexion range of motion (RoM), and knee valgus RoM were calculated. In addition, limb symmetry index (LSI) scores were calculated.

RESULTS

No differences were found in movement pattern between males and females. Movement analysis revealed that males had a decrease in knee flexion at IC (p = 0.018), peak knee flexion (p = 0.002), and knee flexion RoM (p = 0.017) in the injured leg compared to the non-injured leg. Females demonstrated a decrease in peak knee flexion (p = 0.011) and knee flexion RoM (p = 0.023) in the injured leg compared to the non-injured leg. Average LSI scores were 92.4% for males and 94.5% for females.

CONCLUSIONS

Although LSI scores were > 90%, clinical relevant altered movement patterns were detected in the injured leg compared to the non-injured leg. Caution is warranted to solely rely on LSI scores to determine RTS readiness.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION

The University of Groningen, ID 2012.362.

LEVEL OF EVIDENCE

III.

Clinical Factors That Predict a Second ACL Injury After ACL Reconstruction and Return to Sport: Preliminary Development of a Clinical Decision Algorithm

Background

Biomechanical predictors of a second anterior cruciate ligament (ACL) injury after ACL reconstruction (ACLR) and return to sport (RTS) have been identified; however, these measures may not be feasible in a standard clinical environment.

Purpose/Hypothesis

The purpose of this study was to evaluate whether standard clinical measures predicted the risk of second ACL injuries. The hypothesis tested was that a combination of strength, function, and patient-reported measures at the time of RTS would predict the risk of second ACL injuries with high sensitivity and specificity.

Study Design

Case-control study; Level of evidence, 3 and Cohort study (prognosis); Level of evidence, 1.

Methods

A total of 163 participants (mean age, 16.7 ± 3.0 years) who underwent primary ACLR and were able to RTS were evaluated. All participants completed an assessment of isokinetic strength, hop testing, balance, and the Knee Injury and Osteoarthritis Outcome Score (KOOS). Participants were tracked for a minimum of 24 months to identify occurrences of a second ACL injury. The initial 120 participants enrolled were used to develop a clinical prediction model that utilized classification and regression tree (CART) analysis, and the remaining 43 participants enrolled were used as a validation dataset. Additional analyses were performed in all 163 participants using Kaplan-Meier analysis and Cox proportional hazards modeling.

Results

Approximately 20% (23/114) of the initial subset of the cohort suffered a second ACL injury. CART analysis identified age, sex, knee-related confidence, and performance on the triple hop for distance at the time of RTS as the primary predictors of a second ACL injury. Using these variables, a model was generated from which high-risk (n = 53) and low-risk groups (n = 61) were identified. A total of 22 participants in the high-risk group and 1 participant in the low-risk group suffered a second ACL injury. High-risk participants fit 1 of 2 profiles: (1) age <19 years, triple hop for distance between 1.34 and 1.90 times body height, and triple hop for distance limb symmetry index (LSI) <98.5% (n = 43) or (2) age <19 years, triple hop for distance >1.34 times body height, triple hop for distance LSI >98.5%, female sex, and high knee-related confidence (n = 10). The validation step identified the high-risk group as being 5 times (odds ratio, 5.14 [95% CI, 1.00-26.46]) more likely to suffer a second ACL injury, with a sensitivity of 66.7% and specificity of 72.0%.

Conclusion

These findings recognize measures that accurately identify young patients at high risk of sustaining a second ACL injury within 24 months after RTS. The development of a clinical decision algorithm to identify high-risk patients, inclusive of clinically feasible variables such as age, sex, confidence, and performance on the triple hop for distance, can serve as a foundation to re-evaluate appropriate discharge criteria for RTS.

Bench-to-bedside: Bridge-enhanced anterior cruciate ligament repair

Anterior cruciate ligament (ACL) injuries are one of the most well-known orthopaedic injuries and are treated with one of the most common orthopaedic procedures performed in the United States. This surgical procedure, ACL reconstruction, is successful at restoring the gross stability of the knee. However, the outcomes of ACL reconstruction can be limited by short and long-term complications, including muscle weakness, graft rupture, and premature osteoarthritis. Thus, new methods of treating this injury are being explored. This review details the pathway of how a tissue engineering strategy can be used to improve the healing of the ACL in preclinical studies and then translated to patients in an FDA-approved clinical study. This review paper will outline the clinical importance of ACL injuries, history of primary repair, the pathology behind failure of the ACL to heal, pre-clinical studies, the FDA approval process for a high risk medical device, and the preliminary results from a first-in-human study. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2606-2612, 2017.

Knee Stability and Movement Coordination Impairments: Knee Ligament Sprain Revision 2017

The Orthopaedic Section of the American Physical Therapy Association (APTA) has an ongoing effort to create evidence-based practice guidelines for orthopaedic physical therapy management of patients with musculoskeletal impairments described in the World Health Organization's International Classification of Functioning, Disability, and Health (ICF). The purpose of these revised clinical practice guidelines is to review recent peer-reviewed literature and make recommendations related to knee ligament sprain. J Orthop Sports Phys Ther. 2017;47(11):A1-A47. doi:10.2519/jospt.2017.0303.

The diameter of single bundle, hamstring autograft does not significantly influence revision rate or clinical outcomes after anterior cruciate ligament reconstruction

BACKGROUND

Anterior cruciate ligament (ACL) graft failure is a complication of ACL reconstruction (ALCR). Smaller autograft diameter may be a contributing factor. Our aim was to determine if hamstring autograft diameter influences graft rupture and patient-reported outcome scores.

METHODS

This study included 786 consecutive patients undergoing primary, single bundle, autograft hamstring ACLR. The primary outcome was revision ACLR surgery. Secondary outcomes were patient reported International Knee Documentation Committee (IKDC) score, Knee Injury & Osteoarthritis Outcome Score (KOOS) and Tegner Activity score. Multiple logistic regression and Fischer Exact tests were employed for statistical analysis.

RESULTS

Increasing autograft diameter did not lead to a reduction in revision ACLR surgery (odds ratio [OR], 1.093; 95% confidence interval [CI], 0.612 to 1.954; P=0.76). Revision ACLR positively correlated with male gender (OR, 3.971; 95% CI 1.109 to 14.214; P=0.03) and negatively correlated with increasing age (OR, 0.919; 95% CI 0.882-0.958, P<0.0001). There was no association between graft rupture rate and dichotomized graft size. At latest follow-up, there was no correlation between graft diameter and IKDC (Pearson's adjusted R²=0.058; P=0.75), Tegner Activity score (Pearson's adjusted R²=0.244; P=0.53), or any component of the KOOS (Pearson's adjusted R² range: 0.008 to 0.141; P-value range: 0.21 to 0.76).

CONCLUSION

Increased hamstring autograft diameter did not significantly reduce revision ACLR surgery or improve clinical outcomes. Other factors such as gender and age do influence the rate of revision ACL surgery.

STUDY DESIGN

Level IV, retrospective case series.

Younger Patients and Men Achieve Higher Outcome Scores Than Older Patients and Women After Anterior Cruciate Ligament Reconstruction

BACKGROUND

There is some evidence that functional performance and validated outcome scores differ according to the gender, age, and sport participation status of a patient after anterior cruciate ligament (ACL) reconstruction. However, the impact of these three factors, and interaction among them, has not been studied across a large relatively homogeneous group of patients to better elucidate their impact.

QUESTIONS/PURPOSES

We reviewed a large cohort of patients who had undergone ACL reconstruction to determine if ROM, knee laxity, objective performance measures, and validated outcome scores differed according to (1) gender; (2) age; and (3) sport participation status.

METHODS

This was a retrospective analysis of prospectively collected data. Between 2007 and 2016, we performed 3452 single-bundle ACL reconstructions in patients who participated in sport before ACL injury. Of those, complete followup (including preoperative scores and scores at 1 year after surgery; mean, 14 months; range, 12-20 months) was available on 2672 (77%) of patients. Those lost to followup and those accounted for were not different in terms of age, gender, and sports participation at baseline. The study group consisted of 1726 (65%) men and 946 (35%) women with a mean ± SD age of 28 ± 10 years. For these patients, the following measures were obtained: knee ROM (flexion and extension deficit), instrumented knee laxity, single and triple hop for distance limb symmetry index (LSI), International Knee Documentation Committee (IKDC) subjective evaluation, and Single Assessment Numeric Evaluation score. Mean scores and measures of variability were calculated for each outcome measure. Comparisons were made among gender, age, and sport status.

RESULTS

Men had less knee laxity after reconstruction (men 1.1 ± 2.2 mm, women 1.3 ± 2.4 mm; mean difference 0.2 mm [0.1-0.4], p < 0.001), greater limb symmetry (single limb hop men: 94% ± 12%, women 91% ± 13%, mean difference 3% [2%-4%], p < 0.001), and higher IKDC scores than did women (men 84 ± 12, women 82 ± 12, mean difference 2 [1-3], p < 0.001). With the exception of instrumented laxity, all outcome measures showed reduced deficits and higher scores in younger patients. This was most marked for LSI scores between the youngest and oldest aged patient groups (crossover hop: < 16 years 99% ± 10%, > 45 years 90% ± 16%, mean difference: 9 [5-11], p < 0.001). Patients who had returned to their preinjury sport also scored higher and had smaller deficits for all outcomes except ROM compared with patients who had not returned to sport at the time of followup (IKDC subjective: returned 90 ± 9, no sport 79 ± 12, mean difference 11 points [9-12], p < 0.001; single limb hop: returned 97 ± 10, no sport 91 ± 14, mean difference 6% [5%-7%], p < 0.001).

CONCLUSIONS

This study showed that some of the most commonly used functional performance and validated clinical scores for ACL reconstruction are superior for patients who are younger, male, and have returned to preinjury sport. Reference to these data allows clinicians to more effectively evaluate a patient based on their age, gender, and sport status when making return to sport and rehabilitation decisions.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Gait mechanics and second ACL rupture: Implications for delaying return-to-sport

Second anterior cruciate ligament rupture is a common and devastating injury among young women who return to sport after ACL reconstruction, but it is inadequately understood. The purpose of this study was to compare gait biomechanics and return-to-sport time frames in a matched cohort of young female athletes who, after primary ACLR, returned to sport without re-injury or sustained a second ACL injury. Approximately 6 months after primary reconstruction, 14 young women (age 16 ± 2 years) involved in jumping, cutting, and pivoting sports underwent motion analysis testing after physical therapy and impairment resolution. Following objective return-to-sport clearance, seven athletes sustained a second ACL rupture within 20 months of surgery (13.4 ± 4.9 months). We matched them by age, sex, and sport-level to seven athletes who returned to sports without re-injury. Data were analyzed using a previously validated, EMG-informed, patient-specific musculoskeletal model. Compared to athletes without re-injury, athletes who sustained a second ACL injury received surgery sooner (p = 0.023), had post-operative impairments resolved earlier (p = 0.022), reached criterion-based return-to-sport benchmarks earlier (p = 0.024), had higher body mass index (p = 0.039), and walked with lower peak knee flexor muscle forces bilaterally (p = 0.021). Athletes who sustained a second injury also tended to walk with larger (p = 0.089) and more symmetrical peak knee flexion angles and less co-contraction, all indicative of a more normal gait pattern. Statement of Clinical Significance: Delayed return-to-sport clearance even in the absence of gait or clinical impairments following primary ACL reconstruction may be necessary to mitigate second ACL injury risk in young women. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1894-1901, 2017.

Revision pediatric anterior cruciate ligament reconstruction after failure of iliotibial band technique treated with all-epiphyseal technique in a prepubescent with Ehlers-Danlos syndrome: a case report

The increasing number of pediatric anterior cruciate ligament (ACL) injuries and the failure of nonoperative management of these patients has elicited a concordant response in the surgical community to devise reconstruction techniques that stabilize the knee joint without causing iatrogenic growth disturbances. Likewise, the rise in pediatric ACL reconstructions forecasts a consequent rise in revision ACL reconstructions in patients with open physes. In this case report, we describe a prepubescent with Ehlers-Danlos syndrome and congenital ACL deficiency, who underwent physeal-sparing iliotibial band ACL reconstruction and revision to an all-epiphyseal ACL reconstruction with allograft. We also underscore the lack of evidence addressing graft choice and outcomes for ACL reconstructions in patients with connective tissue disorders.

Femoral positioning influences ipsi-and contralateral anterior cruciate ligament rupture following its reconstruction: Systematic review and meta-analysis

AIM

To systematically review the incidence of ipsilateral graft re-rupture and contralateral anterior cruciate ligament (ACL) rupture following its reconstruction, with special attention to the femoral drilling technique.

METHODS

Systematic review and meta-analysis of high-level prospective studies searched in MEDLINE database following PRISMA statement. The rate of ipsilateral graft re-rupture and contralateral rupture in patients submitted to either transtibial (TT) technique (isometric) or anteromedial (AM) technique (anatomic) was compared.

RESULTS

Eleven studies met the criteria and were included in final analysis. Reconstructions using the AM technique had a similar chance of contralateral ACL rupture when compared to the chance of ipsilateral graft failure (OR = 1.08, P = 0.746). In reconstructions using TT technique, the chance of contralateral ACL rupture was approximately 1.5 times higher than ipsilateral graft failure (OR = 1.49, P = 0.048). Incidence of contralateral lesions were similar among the techniques TT (7.4%) and AM (7.0%) (P = 0.963), but a trend could be noticed with a lower incidence of lesion in the ipsilateral limb when using the TT technique (4.9%) compared to the AM technique (6.5%) (P = 0.081).

CONCLUSION

ACL reconstruction by TT technique leads to lower incidence of graft re-injury than contralateral ACL lesion. There is no difference between the chance of re-injury after AM technique and the chance of contralateral ACL lesion (native ligament) with either technique.

Anterolateral Ligament Reconstruction Techniques, Biomechanics, and Clinical Outcomes: A Systematic Review

PURPOSE

To perform a systematic review of the described anterolateral ligament (ALL) reconstruction techniques, biomechanical performance, and clinical outcomes of ALL reconstruction in the setting of concurrent anterior cruciate ligament (ACL) reconstruction.

METHODS

A systematic review was performed according to PRISMA guidelines using the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, PubMed, MEDLINE, and Embase, from 1980 to present. Inclusion criteria were as follows: ALL reconstruction techniques, ALL reconstruction biomechanical studies, ALL surgical outcomes, English language, human studies with at least 2 years of follow-up, and cadaveric studies. Exclusion criteria were lateral extra-articular tenodesis, ALL anatomic studies, ALL radiographic studies, animal studies, clinical studies with <2 years of follow-up, editorial articles, and surveys.

RESULTS

The systematic review identified 12 articles that met the inclusion criteria: 6 techniques, 5 biomechanical studies, and 1 outcome study were available. Five studies described ALL reconstruction in the setting of ACL reconstruction, whereas 1 study described isolated ALL reconstruction. Femoral tunnel location was most commonly placed posterior and proximal to the lateral epicondyle, whereas 2 studies reported a distal tunnel location. There was little variability in tibial tunnel location. The most common ALL reconstruction graft used was the gracilis tendon. Review of the biomechanical studies revealed internal rotation overconstraint with the posterior/proximal femoral tunnel position but not anterior/distal, although fixation angle and graft tension were inconsistent. Only 1 clinical study with 2 years' follow-up was available and reported improvement in the majority of cases. Complications occurred in 15 patients, including a residual pivot shift in 8% of patients at 2 years after a combined ACL and ALL reconstruction.

CONCLUSIONS

There is inconsistency in the selection of ALL graft femoral attachment location as well as in the biomechanical performance of ALL reconstruction techniques.

LEVEL OF EVIDENCE

Level IV, systematic review of Level IV studies.

Subsequent Surgery After Revision Anterior Cruciate Ligament Reconstruction: Rates and Risk Factors From a Multicenter Cohort

BACKGROUND

While revision anterior cruciate ligament reconstruction (ACLR) can be performed to restore knee stability and improve patient activity levels, outcomes after this surgery are reported to be inferior to those after primary ACLR. Further reoperations after revision ACLR can have an even more profound effect on patient satisfaction and outcomes. However, there is a current lack of information regarding the rate and risk factors for subsequent surgery after revision ACLR.

PURPOSE

To report the rate of reoperations, procedures performed, and risk factors for a reoperation 2 years after revision ACLR.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

A total of 1205 patients who underwent revision ACLR were enrolled in the Multicenter ACL Revision Study (MARS) between 2006 and 2011, composing the prospective cohort. Two-year questionnaire follow-up was obtained for 989 patients (82%), while telephone follow-up was obtained for 1112 patients (92%). If a patient reported having undergone subsequent surgery, operative reports detailing the subsequent procedure(s) were obtained and categorized. Multivariate regression analysis was performed to determine independent risk factors for a reoperation.

RESULTS

Of the 1112 patients included in the analysis, 122 patients (11%) underwent a total of 172 subsequent procedures on the ipsilateral knee at 2-year follow-up. Of the reoperations, 27% were meniscal procedures (69% meniscectomy, 26% repair), 19% were subsequent revision ACLR, 17% were cartilage procedures (61% chondroplasty, 17% microfracture, 13% mosaicplasty), 11% were hardware removal, and 9% were procedures for arthrofibrosis. Multivariate analysis revealed that patients aged <20 years had twice the odds of patients aged 20 to 29 years to undergo a reoperation. The use of an allograft at the time of revision ACLR (odds ratio [OR], 1.79; P = .007) was a significant predictor for reoperations at 2 years, while staged revision (bone grafting of tunnels before revision ACLR) (OR, 1.93; P = .052) did not reach significance. Patients with grade 4 cartilage damage seen during revision ACLR were 78% less likely to undergo subsequent operations within 2 years. Sex, body mass index, smoking history, Marx activity score, technique for femoral tunnel placement, and meniscal tearing or meniscal treatment at the time of revision ACLR showed no significant effect on the reoperation rate.

CONCLUSION

There was a significant reoperation rate after revision ACLR at 2 years (11%), with meniscal procedures most commonly involved. Independent risk factors for subsequent surgery on the ipsilateral knee included age <20 years and the use of allograft tissue at the time of revision ACLR.

Criteria for Return to Sport after Anterior Cruciate Ligament reconstruction with lower reinjury risk (CR'STAL study): protocol for a prospective observational study in France

INTRODUCTION

The decision regarding when to return to sport after an anterior cruciate ligament reconstruction (ACLR) is an important one. Using a variety of subjective and objective parameters, various attempts have been made to determine an optimal timeline for a return to sport after ACLR, but none have been validated.The aim of the present study is therefore to determine which criteria or combination of criteria could allow to return to sport with the lowest possible risk of reinjury.

METHODS AND ANALYSIS

This study is a prospective cohort, single-centre study, with repeated assessments at 6, 9 and 12 months post-ACL surgical reconstruction and including a 3-year follow-up of patients' sporting activity and reinjuries. 275 patients will be included to test explanatory variables. Postural control analysis, knee laxity, questionnaires (International Knee Documentation Committee (IKDC), Tampa Scale of Kinesiophobia-11 (TSK-11), Anterior Cruciate Ligament-Return to Sport After Reinjury (ACL-RSI) and Single Assessment Numeric Evaluation (SANE)), modified Star Excursion Balance Test, running and sprinting biomechanics, Hop Tests and Isokinetic Tests will all be used. The primary outcome will be any reinjury during the follow-up period, defined as a graft rupture, a contralateral ACL rupture or any injury necessitating an interruption of training and requiring a medical consultation. Two groups will be constituted during the follow-up, separating reinjured from non-reinjured patients. In addition, classic analysis and data mining approaches will be used to build predictive models.

ETHICS AND DISSEMINATION

The results of this study will be disseminated through peer-reviewed publications and scientific presentations. Ethical approval was obtained through the ethics committee of the University Hospital of Saint-Etienne (reference number IRBN522015/CHUSTE).