Effect of a functional knee brace on knee flexion and extension strength after anterior cruciate ligament reconstruction

The effect of knee braces on knee joint kinematics at different exercise speeds

This study aims to investigate the influence of a new semi-rigid knee joint braces on kinematics using the Opti-knee knee joint kinematic analysis system at various exercise speeds. Twenty-four healthy young male adults were recruited for this study. Participants were randomly assessed while wearing and not wearing knee brace at four different speeds on a treadmill: normal walking (3.6 km/h), brisk walking (5.4 km/h), jogging (9 km/h), and moderate intensity running (10.8 km/h). Six degrees of freedom kinematic data from the knee joint were collected. Paired t-tests were conducted to calculate the kinematic differences. At speeds of 3.6 km/h and 5.4 km/h, wearing the knee brace led to reduced knee joint mobility in anterior-posterior translation, superior-inferior translation, internal-external rotation, and flexion-extension angles during the stance phase (P < 0.05). At 9 km/h, wearing the brace reduced knee joint internal-external rotation and flexion-extension mobility during the stance phase (P < 0.05). At 10.8 km/h, wearing the brace reduced knee joint flexion-extension mobility during the stance phase (P < 0.05). Wearing brace has significant influence on knee kinematics at four speeds, and the effect of brace varies with the speed of movement.

Brace-Free Rehabilitation after Isolated Anterior Cruciate Ligament Reconstruction with Hamstring Tendon Autograft Is Not Inferior to Brace-Based Rehabilitation-A Randomised Controlled Trial

PURPOSE

The postoperative use of a rehabilitative knee brace after isolated primary anterior cruciate ligament (ACL) reconstruction (ACLR) using a hamstring tendon (HT) autograft is controversial. A knee brace may provide subjective safety but can cause damage if applied incorrectly. The aim of this study is to evaluate the effect of a knee brace on clinical outcomes following isolated ACLR using HT autograft.

METHODS

In this prospective randomised trial, 114 adults (32.4 ± 11.5 years, 35.1% women) underwent isolated ACLR using HT autograft after primary ACL rupture. Patients were randomly assigned to wear either a knee brace (n = 58) or no brace (n = 56) for 6 weeks postoperatively. An initial examination was performed preoperatively, and at 6 weeks and 4, 6, and 12 months. The primary endpoint was the subjective International Knee Documentation Committee (IKDC) score to measure participants' subjective perceptions. Secondary endpoints included objective knee function assessed by IKDC, instrumented knee laxity measurements, isokinetic strength tests of the knee extensors and flexors, Lysholm Knee Score, Tegner Activity Score, Anterior Cruciate Ligament-Return to Sport after Injury Score, and quality of life determined by Short Form-36 (SF36).

RESULTS

There were no statistically significant or clinically meaningful differences in IKDC scores between the two study groups (3.29, 95% confidence interval (CI) -1.39 to 7.97, p = 0.03 for evidence of non-inferiority of brace-free compared with brace-based rehabilitation). The difference in Lysholm score was 3.20 (95% CI -2.47 to 8.87); the difference in SF36 physical component score 0.09 (95% CI -1.93 to 3.03). In addition, isokinetic testing did not reveal any clinically relevant differences between the groups (n.s.).

CONCLUSIONS

Brace-free rehabilitation is non-inferior to a brace-based protocol regarding physical recovery 1 year after isolated ACLR using HT autograft. Consequently, the use of a knee brace might be avoided after such a procedure.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Physiotherapy After Anterior Cruciate Ligament Reconstruction a Literature Review

Introduction: The anterior cruciate ligament (ACL) is the main stabiliser that inhibits excessive anterior translation of the tibia and prevents excessive rotational movements of the knee joint. ACL injuries occur at a frequency of 30 to 78 per 100,000 people a year, leading to instability and impaired function of the knee joint. Continuous development of knowledge on the anatomy and functions of the anterior cruciate ligament, along with the improvement of surgical and physiotherapeutic techniques, allowed for the development of satisfactory modern methods for treating ACL lesions.Objective: The aim of the study is to review literature on modern methods of physiotherapy after the reconstruction of the anterior cruciate ligament.Material and methods: Pubmed, Google Scholar and ScienceDirect scientific databases were searched using a combination of keywords: anterior cruciate ligament, ACL, reconstruction, physiotherapy, protocol. The inclusion criteria were: publication date from the last 10 years and a detailed description of the physiotherapy protocol included.Results: Six publications meeting the inclusion criteria were included in the analysis. Selected physiotherapy protocols consisted of 3 to 5 phases. Phase 1 was focused on reducing pain and swelling in all cases. The purpose of the following phases was to increase the range of motion and to strengthen muscle strength as well as neuromuscular coordination. The final stage consisted of dynamic exercises allowing to prepare for a chosen sports activity.Conclusion: Contemporary protocols for physiotherapy after ACL reconstruction are based on early recovery of range of motion in the knee joint, early increase in load on the operated limb as well as shortening (or excluding) the period of immobilisation and the use of orthoses.

Neoprene Knee Sleeves of Varying Tightness Augment Barbell Squat One Repetition Maximum Performance Without Improving Other Indices of Muscular Strength, Power, or Endurance

ABSTRACT

Machek, SB, Cardaci, TD, Wilburn, DT, Cholewinski, MC, Latt, SL, Harris, DR, and Willoughby, DS. Neoprene knee sleeves of varying tightness augment barbell squat one repetition maximum performance without improving other indices of muscular strength, power, or endurance. J Strength Cond Res 35(2S): S6-S15, 2021-Neoprene knee sleeves are commonly used by powerlifters and recreational users but are heavily under-researched. Furthermore, no data exist on whether knee sleeves of varying compressive tightness impact muscular performance similar to commonly used knee wraps, which are both generally effective and more so when increasingly constrictive. Fifteen resistance trained, knee sleeve naive, recreational weight lifting men (22.1 ± 4.1 years; 177.5 ± 5.9 cm; 87.8 ± 7.8 kg) visited the laboratory on 3 separate occasions one week apart, assigned in a randomized, crossover, and counterbalanced fashion to either a minimally supportive control sleeve (CS) condition, a manufacturer-recommended sizing neoprene knee sleeve ("normal" sleeve; NS), or a one size smaller (than NS) neoprene knee sleeve (tighter sleeve [TS]). On each visit, subjects sequentially completed vertical jump (countermovement and squat jumps for both peak and mean power), one repetition maximum (1RM) barbell squat, and GymAware assessments (peak power, peak velocity, and dip) at 90% (reported) and 100% (tested) 1RM as well as one-leg extension (1RM, repetitions to failure, and total volume load at 75% 1RM) tests. All data were analyzed using one-way repeated measures analysis of variance at p < 0.05. Analysis revealed a significant condition effect on barbell squat 1RM (p = 0.003; η2 = 0.339), whereby both NS (p = 0.044; 166 ± 24 kg) and TS (p = 0.019; 166 ± 21 kg) outperformed CS (161 ± 22 kg), with no difference between neoprene sleeves. Conversely, no other tested parameters differed between knee sleeve conditions (p ≥ 0.05). The present results demonstrate that neoprene knee sleeves may function independent of tightness, relative to recommended sizing and ultimately unlike knee wraps. Furthermore, the singular benefits observed on barbell squat maximal strength potentially suggests an exercise-specific benefit yet to be fully elucidated.

Soft-stop knee brace for rehabilitation from ligament injuries: Design and pilot trial

Ligaments within the human knee are commonly torn or injured as a result of sports that involve sharp direction changes, pivoting and landing. For this reason, athletes are often side-lined from their respective sports for up to 18 months after injury to rehabilitate. As part of the rehabilitation process, knee braces are often prescribed in an attempt to decrease the recovery period of the injured individual by restraining and minimizing the motion at the knee. However, the true efficacy of knee bracing is yet to be fully evaluated as studies show mixed results to whether braces actually decrease the rehabilitation period for patients. This paper describes the design and pilot trials of a simple but novel knee brace design that aims to actively aid the rehabilitation of the knee from ligament injuries, primarily the anterior cruciate ligament (ACL). The newly developed knee brace uses an angle locking mechanism with dampers to control both the range of motion of the knee joint and the resistance applied to the knee joint at the limits of extension. Using finite element analysis, these dampers were designed help build muscle strength during everyday use of the knee brace and to reduce the 'jarring effect' which causes significant pain and risk to patients using current knee brace designs. Through providing these features, this new knee brace design has the potential to help improve the extent and speed of recovery for ACL impaired patients.

Functional Bracing After Anterior Cruciate Ligament Reconstruction: A Systematic Review

INTRODUCTION

The purpose of this study was to evaluate the current literature on the use of functional knee braces after anterior cruciate ligament (ACL) reconstruction with respect to clinical and in vivo biomechanical data.

METHODS

A systematic search of both the PubMed and Embase databases was performed to identify all studies that reported clinical and/or in vivo biomechanical results of functional bracing versus nonbracing after ACL reconstruction. Extracted data included study design, surgical reconstruction techniques, postoperative rehabilitation protocols, objective outcomes, and subjective outcomes scores. The in vivo biomechanical data collected included kinematics, strength, function, and proprioception. Subjective clinical outcomes scores were collected when available. Quality appraisal analyses were performed using the Cochrane Collaboration tools for randomized and nonrandomized trials to aid in data interpretation.

RESULTS

Fifteen studies met the selection criteria (including 3 randomized trials [level II], 11 nonrandomized trials [level II], and 1 retrospective comparative study [level III]), with follow-up intervals ranging from 3 to 48 months. Most studies were designed to compare the effects of functional bracing versus nonbracing on subjective and objective results in patients who underwent previous primary ACL reconstruction. Functional bracing significantly improved kinematics of the knee joint and improved gait kinetics, although functional bracing may decrease quadriceps activation without affecting functional tests, range of motion, and proprioception. Four studies reported no differences in subjective outcomes scores with brace use; however, one study reported increased patient confidence with brace use, whereas another study reported decreased pain and quicker return to work when the brace was not used.

CONCLUSIONS

The effectiveness of postoperative functional bracing following ACL reconstruction remains elusive. Some data suggest that functional bracing may have some benefit with regard to in vivo knee kinematics and may offer increased protection of the implanted graft after ACL reconstruction without sacrificing function, range of motion, or proprioception. However, limited evidence exists supporting the use of routine functional bracing to decrease the rate of reinjury after ACL reconstruction.

Validity, Reliability, and Responsiveness of the Anterior Cruciate Ligament Quality of Life Measure: A Continuation of Its Overall Validation

OBJECTIVE

The purpose is to provide more validity, reliability, and responsiveness testing of the anterior cruciate ligament-quality of life instrument (ACL-QOL), particularly in light of consensus-based standards for the selection of health status measurement instruments (COSMIN) guidelines.

DESIGN

Prospective case series.

SETTING

An orthopedic surgical practice for consultation.

PATIENTS

A convenience sample of 579 ACL-deficient patients.

INTERVENTION

Anterior cruciate ligament reconstructive surgery.

MAIN OUTCOME MEASURES

Patients completed the ACL-QOL at initial visit and underwent reconstructive surgery. Patients were followed at 6, 12, and 24 months using the ACL-QOL to determine its validity and responsiveness. Cronbach's alpha was used to determine the unidimensionality of the ACL-QOL. A subset of patients took the ACL-QOL twice in a test-retest reliability analysis (intraclass correlation coefficient or ICC 2,k). Another subset of 24-month postsurgical patients measured the success of their surgery using a 7-point global rating scale of improvement as an anchor-based method of responsiveness.

RESULTS

Cronbach's alpha coefficients = 0.93, 0.95, 0.96, and 0.98 at 6, 12, and 24 months, respectively. Intraclass correlation coefficient = 0.60, SEM = 6.16, and confidence interval of 12.1 (CI 95%). Responsiveness was measured by comparing the 4 serial time periods. Patients improved significantly at each time period (P < 0.05, ETA squared 0.61). A 24-month ACL-QOL was significantly correlated (P > 0.05) to being "significantly better" or "somewhat better."

CONCLUSIONS

The results of this study added more validity, reliability, and responsiveness for the ACL-QOL. The ACL-QOL has completed 8 of 9 COSMIN criteria.

Knee Bracing After Anterior Cruciate Ligament Reconstruction

Although some articles in the literature are in favor of the use of a postoperative brace after anterior cruciate ligament (ACL) reconstruction, this review found that several systematic reviews and other reports on the topic do not support the use of a postoperative brace after ACL reconstruction. There is no scientific evidence so far to support the routine use of a functional knee brace following a successful ACL reconstruction in the postoperative course. Most authors believe that bracing is not necessary. There is insufficient evidence to inform current practice. Good-quality randomized trials are required to remedy this situation. Future studies should better define the role of a brace following ACL surgery. A search of MEDLINE for articles published between January 1, 1995, and September 30, 2013, was performed. Key search terms used were ACL reconstruction and knee brace. Ninety-one articles were found, but only 28 focused on the subject of bracing after ACL reconstruction and were selected for this review. Several systematic reviews and randomized, controlled trials on the topic do not recommend the use of postoperative brace after ACL reconstruction. Postoperative bracing after ACL reconstruction does not seem to help with pain, function, rehabilitation, and stability. The literature does not support the use of a postoperative brace following ACL reconstruction. [Orthopedics. 2016; 39(4):e602-e609.].

The Importance of Patient Sex in the Outcomes of Anterior Cruciate Ligament Reconstructions: A Systematic Review and Meta-analysis

BACKGROUND

One of the well-studied epidemiological phenomena of anterior cruciate ligament (ACL) injuries is the 2- to 9-fold increase in the relative risk of ACL rupture in female athletes compared with male athletes. However, the influence of patient sex on the outcome after ACL reconstruction remains unclear, with some authors reporting inferior outcomes in females and others noting no significant difference.

PURPOSE

To provide a comprehensive systematic review and meta-analysis to examine the possible association between patient sex and the subjective and objective outcomes after ACL reconstruction.

METHODS

This study was conducted according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. All studies that reported clinical outcomes after ACL reconstruction in males and females independently were included in the review. A quantitative random-effects meta-analysis was performed to compare outcomes between sexes. For outcomes with considerable heterogeneity, meta-regression was used to identify potential moderators. Articles were evaluated qualitatively when quantitative data were not reported.

RESULTS

A total of 135 publications were included in the review. Females had inferior outcomes in instrumented laxity (standardized mean difference [SMD], 0.24; 95% CI, 0.11-0.37), revision rate (relative risk [RR], 1.15; 95% CI, 1.02-1.28), Lysholm score (SMD, -0.33; 95% CI, -0.55 to -0.11), Tegner activity scale (SMD, -0.37; 95% CI, -0.49 to -0.24), and incidence of not returning to sports (RR, 1.12; 95% CI, 1.04-1.21), all of which were statistically significant. Other outcomes were comparable between sexes, including anterior drawer test, Lachman test, pivot-shift test, timed single-legged hop test, single-legged hop test, quadriceps testing, hamstring testing, extension loss, flexion loss, development of cyclops lesion, and International Knee Documentation Committee (IKDC) knee examination score. Females and males were equally likely to develop anterior knee pain and osteoarthritis after ACL reconstruction. The graft rupture and graft failure rates did not differ significantly between sexes.

CONCLUSION

There were comparable or inferior results for females compared with males in all outcomes analyzed. No statistically significant sex difference was identified in most of the objective parameters. However, subjective and functional outcomes, including Lysholm score, Tegner activity scale, and ability to return to sports, have been shown to be poorer in females.

Return to play following ACL reconstruction: a systematic review about strength deficits

PURPOSE

There is a lack of consensus regarding appropriate criteria attesting patients' unrestricted sports activities after ACL reconstruction. Purpose of this study was to perform a systematic review about strength deficits to find out if a strength test might be a return to play criterion.

DATA SOURCE

Pubmed central, Google Scholar.

STUDY ELIGIBILITY CRITERIA

English language articles.

INTERVENTIONS

Strength tests after ACL reconstruction with autologous tendon grafts.

METHODS

A systematic search for articles about muscle strength after ACL reconstruction was performed.

RESULTS

Forty-five articles could be identified. All articles identified reported strength deficits after ACL reconstruction in comparison to control subjects. Some of these deficits persisted up to 5 years after surgery. Knee flexor strength is more impaired after ACL reconstruction with hamstring grafts and quadriceps strength after BPTB ACL reconstruction.

CONCLUSION

Strength deficits of hip, knee and ankle muscles are reported after ACL reconstruction. Muscular strength test may be an important tool to determine if an athlete can return to competitive sports after ACL reconstruction.

Influence of functional knee bracing on the isokinetic and functional tests of anterior cruciate ligament deficient patients

Use of functional knee braces has been suggested to provide protection and to improve kinetic performance of the knee in Anterior cruciate ligament(ACL)-injured patients. However, many athletes might refrain from wearing the braces because of the fear of performance hindrance in the playing field. The aim of this study was to examine the effect of three functional knee brace/sleeves upon the isokinetic and functional performance of ACL-deficient and healthy subjects. Six anterior cruciate ligament deficient (29.0±5.3 yrs., 175.2±5.4 cm, and 73.0±10.0 kg) and six healthy male subjects (27.2±3.7 yrs., 176.4±6.4 cm, and 70.3±6.9 kg) were selected. The effect of a custom-made functional knee brace, and two neoprene knee sleeves, one with four metal supports and one without support were examined via the use of isokinetic and functional tests in four sets (non-braced,wearing functional knee brace,and wearing the sleeves). Cross-over hop and single leg vertical jump test were performed and jump height, and hop distance were recorded. Peak torque to body weight ratio and average power in two isokinetic velocities(60°.s⁻¹,180°.s⁻¹) were recorded and the brace/sleeves effect was calculated as the changes in peak torque measured in the brace/sleeves conditions, expressed as a percentage of peak torque measured in non-braced condition. Frequency content of the isokinetic torque-time curves was also analyzed. Wilcoxon signed rank test was used to compare the measured values in four test conditions within each control and ACL-deficient group,and Mann-Whitney U test was used for the comparison between the two groups. No significant differences in peak torque, average power, torque-time curve frequency content, vertical-jump and hop measurements were found within the experimental and the non-braced conditions (p>0.05). Although the examined functional knee brace/sleeves had no significant effect on the knee muscle performance, there have been some enhancement regarding the extension peak torques and power generating capacity of the ACL-deficient subjects that could be helpful in reducing the bilateral asymmetry in these patients.

Quadriceps function after exercise in patients with anterior cruciate ligament-reconstructed knees wearing knee braces

CONTEXT

Knee braces and neoprene sleeves are commonly worn by people with anterior cruciate ligament reconstructions (ACLRs) during athletic activity. How knee braces and sleeves affect muscle activation in people with ACLRs is unclear.

PURPOSE

To determine the effects of knee braces and neoprene knee sleeves on the quadriceps central activation ratio (CAR) before and after aerobic exercise in people with ACLRs.

DESIGN

Crossover study.

PATIENTS OR OTHER PARTICIPANTS

Fourteen people with a history of ACLR (9 women, 5 men: age = 23.61 ± 4.44 years, height = 174.09 ± 9.82 cm, mass = 75.35 ± 17.48 kg, months since ACLR = 40.62 ± 20.41).

INTERVENTION(S)

During each of 3 sessions, participants performed a standardized aerobic exercise protocol on a treadmill. The independent variables were condition (brace, sleeve, or control) and time (baseline, pre-exercise with brace, postexercise with brace, postexercise without brace).

MAIN OUTCOME MEASURE(S)

Normalized torque measured during a maximal voluntary isometric contraction (T(MVIC)) and CAR were measured by a blinded assessor using the superimposed burst technique. The CAR was expressed as a percentage of full muscle activation. The quadriceps CAR and T(MVIC) were measured 4 times during each session: baseline, pre-exercise with brace, postexercise with brace, and postexercise without brace.

RESULTS

Immediately after the application of the knee brace, T(MVIC) decreased (P = .01), but no differences between bracing conditions were observed. We noted reduced T(MVIC) and CAR (P < .001) after exercise, both with and without the brace. No differences were seen between bracing conditions after aerobic exercise.

CONCLUSIONS

The decrease in T(MVIC) immediately after brace application was not accompanied by differences between bracing conditions. Wearing a knee brace or neoprene sleeve did not seem to affect the deterioration of quadriceps function after aerobic exercise.

The effects of a prophylactic knee brace and two neoprene knee sleeves on the performance of healthy athletes: a crossover randomized controlled trial

Knee injury is one of the major problems in sports medicine, and the use of prophylactic knee braces is an attempt to reduce the occurrence and/or severity of injuries to the knee joint ligament(s) without inhibiting knee mobility. The aim of the present study was to examine the effect of one recently designed prophylactic knee brace and two neoprene knee sleeves upon performance of healthy athletes. Thirty-one healthy male athletes (age = 21.2 ± 1.5) volunteered as participants to examine the effect of prophylactic knee brace/sleeves on performance using isokinetic and functional tests. All subjects were tested in four conditions in a random order: 1. nonbraced (control) 2. using a neoprene knee sleeve 3. using a knee sleeve with four bilateral metal supports and 4. using a prophylactic knee brace. The study design was a crossover, randomized, controlled trial. Subjects completed single leg vertical jump, cross-over hop, and the isokinetic knee flexion and extension (at 60, 180, 300°/sec). Data were collected from the above tests and analyzed for jump height, cross-over hop distance, peak torque to body weight ratio and average power, respectively. Comparisons of these variables in the four testing conditions revealed no statistically significant difference (p>0.05). The selected prophylactic brace/sleeves did not significantly inhibit athletic performance which might verify that their structure and design have caused no complication in the normal function of the knee joint. Moreover, it could be speculated that, if the brace or the sleeves had any limiting effect, our young healthy athletic subjects were well able to generate a mean peak torque large enough to overcome this possible restriction. Further studies are suggested to investigate the long term effect of these prophylactic knee brace and sleeves as well as their possible effect on the adjacent joints to the knee.

Two- to 4-year follow-up to a comparison of home versus physical therapy-supervised rehabilitation programs after anterior cruciate ligament reconstruction

BACKGROUND

There have been no long-term follow-up studies comparing a predominantly home-based rehabilitation program with a standard physical therapy program after anterior cruciate ligament (ACL) reconstruction. Demonstrating the long-term success of such a cost-effective program would be beneficial to guide future rehabilitation practice.

PURPOSE

To determine whether there were any differences in long-term outcome between recreational athletes who performed a physical therapy-supervised rehabilitation program and those who performed a primarily home-based rehabilitation program in the first 3 months after ACL reconstruction.

STUDY DESIGN

Randomized clinical trial; Level of evidence, 1.

METHODS

Patients were randomized before ACL reconstruction surgery to either the physical therapy-supervised (17 physical therapy sessions) or home-based (4 physical therapy sessions) program. Eighty-eight of the original 129 patients returned 2 to 4 years after surgery to assess their long-term clinical outcomes. Primary outcome was the ACL quality of life questionnaire (ACL QOL). Secondary outcomes were bilateral difference in knee extension and flexion range of motion, sagittal plane knee laxity, relative quadriceps and hamstring strength, and objective International Knee Documentation Committee score. Unpaired t tests and a chi-square test were used for the comparisons.

RESULTS

The home-based group had a significantly higher mean ACL QOL score (80.0 +/- 16.2) than the physical therapy-supervised group (69.9 +/- 22.0) a mean of 38 months after surgery (P = .02, 95% confidence interval [CI]: 1.7, 18.4). The mean change in ACL QOL score from before surgery to follow-up was not significantly different between the groups (physical therapy = 40.0, home = 45.8, P = .26, 95% CI: -15.8, 4.4). There were no significant differences in the secondary outcome measures.

CONCLUSION

This long-term study upholds the short-term findings of the original randomized clinical trial by demonstrating that patients who participate in a predominantly home-based rehabilitation program in the first 3 months after ACL reconstruction have similar 2- to 4-year outcomes compared with those patients who participate in a more clinically supervised program.

Effect of functional bracing on knee injury in skiers with anterior cruciate ligament reconstruction: a prospective cohort study

BACKGROUND

The role of knee bracing in anterior cruciate ligament reconstructions is controversial.

HYPOTHESIS

Functional bracing will have an effect on subsequent knee injury in skiers with anterior cruciate ligament reconstruction.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

From 1991 to 1997, 11606 skiers at a major destination ski resort underwent preseason knee screening. The anterior cruciate ligament-reconstructed group consisted of 820 skiers who had had an anterior cruciate ligament reconstruction 2 years or more earlier. Of these, 257 skiers selected the use of functional knee brace during skiing. The dependent variable was subsequent knee injury, identified via workers' compensation records. Covariates included age, gender, ski occupation, Lachman grade, pivot-shift grade, KT-1000 arthrometer manual maximum displacement, and use of a functional brace. Univariate and multivariate risk factors for subsequent knee injury were determined.

RESULTS

In this study, 257 skier-employees with anterior cruciate ligament reconstruction wore braces and 563 skier-employees with anterior cruciate ligament reconstruction did not. Braced skiers had significantly higher preseason rates of grade II or higher Lachman and pivot-shift tests (braced, 29% and 22%, respectively; nonbraced, 11% and 10%, respectively; P < .05). Sixty-one subsequent knee injuries were identified, 51 (8.9 injuries/100 knees/ski season) in the nonbraced group and 10 (4.0 injuries/100 knees/ski season) in the braced group (P = .009). Nonbraced skiers were 2.74 times more likely to suffer subsequent injury than were braced skiers (odds ratio, 2.74 [confidence interval, 1.2-4.9]). Logistic regression modeling identified nonbracing as a significant independent multivariate risk factor for subsequent knee injury in the high-demand skiers with anterior cruciate ligament reconstruction.

CONCLUSION

Because of the increased risk of subsequent knee injury in nonbraced skiers, the authors recommend functional bracing for skiers with anterior cruciate ligament reconstruction. Whether the protective effect of functional bracing can be extrapolated to other high-demand patients is yet to be determined.

Return to play after anterior cruciate ligament reconstruction

The goal of knee ligament reconstruction is to return the athlete to the previous level of function as quickly and as safely as possible. The appropriate level of aggressiveness in returning the athlete to sport remains controversial. Information in the literature regarding safe return to play has been dominated by the anterior cruciate ligament (ACL) reconstruction literature. The basic concepts that hold true for returning the ACL-reconstructed athlete to play can be generalized to injuries treated nonoperatively as well. This article presents a review of the principles of rehabilitation following knee ligament reconstruction, with an emphasis on criteria for return to play.