Evaluation of functional deficits determined by four different hop tests in patients with anterior cruciate ligament deficiency

Lower extremity movement quality in professional team sport athletes: Inter-rater agreement and relationships with quantitative results from the corresponding pattern

BACKGROUND

Adequate movement control and quality can be prerequisite functions for performance of the lower extremity. The purposes of our work were 1) to explore the agreement of an efficient test battery assessing qualitative movement execution and 2) to determine its consistency with quantitative performance tests from the corresponding movement pattern.

METHODS

The participants were professional male association football players competing in the first German Bundesliga. They performed four movement quality tests (Single-limb balance squat, Balance forward hop, Balance side hop, Balance 90° rotation hop) and the corresponding performance tests (Y-balance test, Forward hop for distance, Side hop test, Square hop test). Qualitative tests were judged by two experienced raters; the ratings were compared to determine inter-rater agreement using Kappa statistics. The relationship with the quantitative tests was determined using Spearman's rank correlations.

RESULTS

Thirty participants (19 to 33 years old) were included in this study. We found an at least substantial level of agreement (Cohen's Kappa, 0.64-0.84) with an excellent percentage of exact (83-93%) agreement between the two raters for the movement quality tests. Our findings revealed that the quantitative test results are only slightly related to the movement quality outcomes (ρ(27) <|0.3| and P > 0.2).

CONCLUSIONS

Consequently, the qualitative test results provide unique information and complement corresponding quantitative performance tests in professional football athletes. Their observational judgement of foot position, lower limb alignment and upper body control in sagittal, frontal, and transverse planes is agreeable.

Side-to-side differences in knee laxity and side hop test may predispose an anterior cruciate ligament reinjury in competitive adolescent alpine skiers

An anterior cruciate ligament (ACL) injury is a common, severe injury in alpine skiing, and anterior cruciate ligament reconstruction (ACLR) is frequently performed in competitive alpine skiers younger than 20 years old. To reduce the reinjury rate, both intrinsic and extrinsic risk factors should be examined. The aim of this study was to investigate possible intrinsic risk factors for an ACL reinjury in competitive alpine skiers. A cohort of 384 alpine skiers (191 males/193 females) from the Swedish ski high schools were prospectively followed during their high school years. The students were clinically examined and physically tested prior to each ski season. In addition, the RAND 36-Item health survey 1.0 (SF-36, Copyright 1994 Medical Outcome Trust, distributed by RAND Corporation) and injuries were prospectively registered. Thirty-one of the skiers (five males/26 females) had undergone an ACLR before entering the ski high school. This cohort was analyzed with respect to the occurrence of, and possible risk factors for an ACL reinjury (including ipsilateral and contralateral ACL injuries). Skiers who sustained an ACL reinjury were called the “ACL reinjury group,” and those who did not sustain an ACL reinjury were called the “ACL injury group.” Notably, 12 of the 31 students (39%), ten female and two male skiers, aged 16.5 (SD 0.5) years, sustained an ACL reinjury during the two first years at the ski high school. In addition, 10 of the 12 ACL reinjuries occurred within 10–23 months from the first injury [m 14.8 (SD4.7)] and two ACL reinjuries occurred at 29 and 47 months, respectively, from the first injury. It is noted that eight of the ACL reinjuries were to the ipsilateral knee and four to the contralateral knee. There were no differences between the groups with respect to muscle flexibility in the lower extremity, Beighton score, and one leg hop for distance or square hop test. Side-to-side differences were found with respect to knee joint laxity, >3 mm, measured with KT-1000 arthrometer (p = 0.02), and the side hop test (p = 0.04). RAND 36-Item health survey did not predict an ACL reinjury. In conclusion, a side-to-side difference in the side hop test and knee joint laxity (KT-1000) may predispose an ACL reinjury in competitive adolescent alpine skiers.

Clinical, functional, and patient-reported outcome of traumatic knee dislocations: a retrospective cohort study of 75 patients with 6.5-year follow-up

INTRODUCTION

At present, limited knowledge regarding clinical, functional, and patient-reported outcomes at mid- and long-terms after surgical treatment of traumatic knee dislocations is available. This study aimed to investigate the mid-term recovery regarding clinical, functional, and patient-reported outcomes in patients following knee dislocation with associated multi-ligament injuries.

MATERIALS AND METHODS

The study design was a cross-sectional cohort study. Data were collected by retrospective chart review, clinical examination, and interview of patients. All patients treated surgically following a knee dislocation between January 2000 and December 2011 were included. The surgical technique was up to the decision of the individual surgeon. The main outcome was the Lysholm knee score. Secondary outcomes consist of clinical knee examination, functional performance test, pain, and patient-reported outcome across several domains in function, sport, pain, and quality of life.

RESULTS

Seventy-five patients (66.3%) accepted the invitation to participate. The mean age at the time of knee dislocation was 33.5 years, with a range of 16-65 years of age. The mean follow-up time was 78 months (R: 17-147). 75% of patient a Schenck's type 1 lesion and 23% a type 3. The median Lysholm knee score was 83 (R: 18-100). The mean KOOS for the five subscales were pain 84.5 (95% CI 80.5-88.5), symptoms 75.1 (95% CI 70.7-79.4), ADL 87.0 (95% CI 83.1-90.9), sport 59.9 (95% CI 53.3-66.4), and QOL 71.3 (95% CI 67.0-75.6). The mean Tegner activity level was 5.1 (95% CI 4.5-5.7). The median single assessment numeric evaluation (SANE) was 93 (R: 0-100). The pain intensity score for pain (VAS) during activity was reported with a mean of 2.7 (95% CI 2.1-3.3). The objective IKDC examination showed 76% of patients grouped by Grade A (normal knee function) or Grade B (nearly normal).

CONCLUSION

With a mean follow-up of 6.5 years, combined repair and reconstruction surgery following a knee dislocation shows good to excellent patient-reported outcome and more than 75% of patients experiencing normal knee functioned evaluated by the IKDC score.

A Minority of Athletes Pass Symmetry Criteria in a Series of Hop and Strength Tests Irrespective of Having an ACL Reconstructed Knee or Being Noninjured

BACKGROUND

Between-leg symmetry in 1-leg hop and knee strength performances is considered important after anterior cruciate ligament reconstruction (ACLR) to facilitate a safer return to sport. While few athletes with ACLR demonstrate symmetry in test batteries, reference data for noninjured athletes are lacking, thus questioning how ACLR-specific poor symmetry is.

HYPOTHESIS

Athletes with ACLR (hamstring autograft) show lower symmetry and have a lower proportion of symmetric individuals than noninjured athletes for knee flexion strength but not for hop for distance, vertical hop, and knee extension strength.

STUDY DESIGN

Cross-sectional.

LEVEL OF EVIDENCE

Level 3.

METHODS

A total of 47 athletes with ACLR (median 13.0 months post-ACLR) who had returned to their sport, and 46 noninjured athletes participated. Symmetry was calculated between the worse and better legs for each test and combinations of them using the limb symmetry index (LSI_WORSE-BETTER, ranging from 0% to 100%). The 2 groups were compared for these values and the proportions of individuals classified as symmetric (LSI_WORSE-BETTER ≥90%) using independent t-tests and Fisher's exact tests, respectively.

RESULTS

Athletes with ACLR were less symmetric than noninjured athletes for knee flexion strength with a lower LSI_WORSE-BETTER (83% vs 91%, P < 0.01) and a lower proportion of symmetric individuals (39% vs 63%, P = 0.04). No differences between groups were revealed for the hop tests, knee extension strength, or combinations of tests (P > 0.05). Only 17% of the athletes with ACLR and 24% of the noninjured athletes demonstrated symmetric performances for all 4 tests.

CONCLUSION

Athletes with ACLR (hamstring autograft) showed poorer symmetry in knee flexion strength than noninjured athletes, although both groups had few individuals who passed the test battery's symmetry criteria.

CLINICAL RELEVANCE

Symmetry is uncommon among athletes irrespective of ACLR and should be considered regarding expected rehabilitation outcomes and return-to-sport decisions post-ACLR.

Evaluation of the Limb Symmetry Index: The Side Hop Test

The main objective of present study was to evaluate inter-rater reliability and concurrent validity of Side Hop Test stopwatch vs. force plates timing, and to determine the number of sessions and trials required to minimize the effects of learning on Side Hop Test total time and limb symmetry index. Fifteen healthy male physical education students (mean ± SD: age, 23 ± 3 years; height, 181 ± 9 cm; and weight 72 ± 6 kg) participated. Side Hop Test total time (stopwatch and force plates) of left and right leg, and limb symmetry index (force plates) were obtained over seven sessions conducted 5–7 days apart. Time recordings of two raters were similar (t = −0.56, p &gt; 0.05) with high reliability (all ICC &gt;0.99 and CV% &lt;0.1) and no systematic bias when compared to force plate data (p &gt; 0.05; for rater 1 and 2, respectively). Total time improved across the Sessions (F = 25.87, p &lt; 0.01, ω2 = 0.18) and Trials (F = 68.15, p &lt; 0.01, ω2 = 0.10), with no significant interaction between factors. No between-leg differences were detected (F = 0.52, p &gt; 0.05, ω2 = 0.001). Limb symmetry index ranged from 0.999 to 1.055 across all sessions and trials (all p &gt; 0.05 and ω2 &lt; 0.00). Due to low coefficient of correlation, high interclass correlation coefficient, and the lack in heteroscedasticity, stopwatch measurements are valid to measure total time in the Side Hop Test. Moreover, stopwatch measurements could be reliably used to measure total time in the Side Hop Test, while the test could be administrated with only one experienced rater. Unlike total times, findings on limb symmetry index suggest it could be reliably assessed after seven familiarization sessions.

Selective bundle reconstruction for symptomatic partial anterior cruciate ligament tears demonstrates good functional scores, high return to sport rates and a low re-tear rate

BACKGROUND

The treatment of symptomatic partial anterior cruciate ligament (ACL) tears remains controversial. This study investigated the clinical and functional outcome of patients undergoing selective posterolateral (PLB) or anteromedial (AMB) bundle reconstruction.

METHODS

55 consecutive patients underwent partial bundle reconstruction, of which 45 (AMB = 17, PLB = 28) were included in the current analysis (62% male, mean age of 29.1 years). Patients were assessed at 12 and 24 months with patient-reported outcome measures (PROMs), graft laxity (KT-1000), knee extensor and flexor torque and a 4-hop battery. Limb Symmetry Indices (LSIs) were calculated. Return to sport (RTS) rates, re-operations and re-injuries were evaluated.

RESULTS

High scoring PROMs were evident, with 62% and 84% of patients participating in pivoting sports at 12 and 24 months, respectively. Overall, 98% of patients demonstrated 'normal' knee laxity at 24 months. Mean LSIs for all hop tests were ≥ 90% at 12 and 24 months, with 76-87% of patients demonstrating LSIs ≥ 90% on the four hop tests employed at 12 months, which was 89-93% of patients at 24 months. A mean knee extensor torque LSI of 89% and 97% was observed at 12 and 24 months. Two ipsilateral re-tears (2/55, 3.6%, AMB = 1, PLB = 1) were observed over the 24-month period, with no contralateral ACL tears.

CONCLUSIONS

High levels of physical function and RTS were observed in patients following partial bundle reconstruction, higher than that reported in the literature in patients undergoing ACLR, without evidence of instability and a low re-injury rate.

The effects of vertical trunk supportability improvement on one-leg rebound jump efficiency

The purpose of this study was to examine the effects of vertical trunk supportability improvement on activities. The study participants were 36 people. Trunk function and physical performance were evaluated using the following tests: trunk righting test (TRT), maximal isometric knee extensor strength test, side hop test, triple hop distance test, stabilometry of one-leg standing, and one-leg rebound jump. The measurement was performed three times: pre-trunk training (pre), post-trunk training for 1 month (post), and 2 months after the second measurement (detraining). Details of trunk training: Two sets of 30-s maximal lateral reach exercises on each side, following the four sets of 15-s maximal raising trunk exercises on each side. The results with TRT in post-training were significantly larger than those in pre-and detraining. Similarly, the results with one-leg rebound jump efficiency in post-training were significantly larger than those in pre-and detraining. Our findings indicate that jump efficiency changes in proportion to the change in vertical trunk supportability.

The Non-injured Leg Can Be Used as a Reference for the Injured Leg in Single-legged Hop Tests

BACKGROUND

Single-legged hop tests are frequently used in substantiating return to sport decisions following lower extremity injury. Evidence for using the non-injured leg as a reference for the injured leg in the return to sport decision-making at the criterion-based point of return to sport following lower extremity injury is lacking.

PURPOSE

To compare absolute values in single-legged hop tests between the non-injured leg of athletes returning to high-impact sports after lower extremity injury and the matched leg of healthy athletes.

STUDY DESIGN

Cross-sectional study.

METHODS

One hundred and sixty-nine athletes returning to high-impact sports after lower extremity injury and 169 matched healthy athletes executed five single-legged hop tests. Differences between athletes returning to high-impact sports after lower extremity injury and matched healthy athletes on five single-legged hop tests were analyzed using paired t-tests.

RESULTS

There were no statistically significant differences between the non-injured leg of athletes returning to sport and the matched leg of healthy athletes. Effect sizes ranged from 0.05 to 0.14 indicating negligible effects.

CONCLUSION

Clinicians can use the non-injured leg as a reference for the injured leg in single-legged hop tests for deciding on return to high-impact sports after lower extremity injuries.

LEVEL OF EVIDENCE

3b.

Knee extensor strength, hop performance, patient-reported outcome and inter-test correlation in patients 9-12 months after anterior cruciate ligament reconstruction

BACKGROUND

Hop performance and isokinetic knee extensor strength (IKES) asymmetry are associated with re-injury after anterior cruciate ligament reconstruction (ACLR). This study investigated deficits after ACLR, and which hop tests are most correlated with IKES and patient-reported outcome measures (PROMs).

METHODS

50 patients were assessed 9-12 months after ACLR using the International Knee Documentation Committee (IKDC) and ACL Return to Sport after Injury (ACL-RSI) scores. Peak IKES and eight hop tests were assessed: single (SHD), triple (THD) and triple crossover (TCHD) hop for distance, 6 m timed hop (6MTH), single medial (MHD) and single lateral (LHD) hop for distance, single countermovement jump (SLCMJ) and timed speedy hop (SHT). The percentage of patients with limb symmetry indices (LSIs) < 90% was reported. Pearson's correlations investigated the correlation between PROMs, IKES and hop LSIs.

RESULTS

The majority (80%) of patients had IKES LSIs < 90%. While 12-14% of patients demonstrated LSIs < 90% for the SHD, 6MTH, THD and TCHD, 52-80% demonstrated LSIs < 90% for the other hop tests. The IKES LSI was significantly different (p < 0.05) from all hop LSIs, besides the SLCMJ (p = 0.638). Large correlations were only observed between the IKES LSI and the SLCMJ (r = 0.82), MHD (r = 0.71) and LHD (r = 0.53). The SLCMJ, MHD and IKES LSIs demonstrated the largest significant correlations with the IKDC (r = 0.51-0.53) and ACL-RSI (r = 0.38-0.40).

CONCLUSIONS

Hop tests such as the MHD and SLCMJ may present a more practical alternative to quantifying peak IKES, especially in the absence of more sophisticated testing equipment. While not surrogates as such, these selective hop measures may better inform the clinician as to whether significant underlying quadriceps deficits are still present throughout the post-operative rehabilitation period.

Sex differences in postural orientation errors and association with objective and patient-reported function in patients with ACL injury: an exploratory cross-sectional study

Objectives

There is limited research on sex differences in postural orientation (ie, alignment between body segments) in people with knee injury measured with a clinically applicable method. An understanding of the relationship between postural orientation and physical function may help guide decision making in rehabilitation. The aims were to evaluate (1) sex differences in visual assessment of Postural Orientation Errors (POEs) and (2) the association between POEs and objective and patient-reported physical function, in men and women with anterior cruciate ligament reconstruction (ACLR).

Methods

Twenty-four women and 29 men (mean 26.7 (SD 6.5) years) with ACLR were included. Six POEs (lower extremity and trunk) were scored from a video of five tasks with varying difficulty to compute POE scores (total and subscores). Objective physical function was evaluated with the single-leg hop for distance and side hop. Patient-reported physical function was evaluated using patient-reported outcome measures (PROMs).

Results

Women had significantly more POEs than men (median difference 5.5–25, p≤0.028). More POEs were associated with shorter hop distance and fewer side hops in women (r_s= −0.425 to −0.518, p<0.038), but not in men (r_s<0.301, p>0.05). No associations were found between POE scores and PROMs, in either sex (r_s< –0.246, p>0.05).

Conclusions

Women with ACLR seem to have more POEs compared with men, indicating worse postural orientation. More POEs were associated with worse hop performance, suggesting that POE scores may be used as criteria for rehabilitation progression. The lack of associations between POE scores and PROMs indicate that these measures complement each other.

Which Hop Tests Can Best Identify Functional Limb Asymmetry in Patients 9-12 Months After Anterior Cruciate Ligament Reconstruction Employing a Hamstrings Tendon Autograft?

BACKGROUND

Hop tests are commonly employed to evaluate functional limb symmetry after anterior cruciate ligament reconstruction (ACLR).

PURPOSE

To investigate the ability of eight hop tests to identify functional limb asymmetry in patients after ACLR.

STUDY DESIGN

Prospective cohort.

METHODS

Fifty patients were assessed 9-12 months following ACLR. Functional performance on both the operated and non-operated limb was assessed via eight hop tests, assessed in a randomised order. These included the: single (SHD), triple (THD) and triple crossover (TCHD) hop for distance, 6m timed hop (6MTH), single medial (MHD) and single lateral (LHD) hop for distance, single countermovement jump (SLCMJ) and timed speedy hop (TSHT). Differences in Limb Symmetry Indices (LSIs) across hop tests were compared, while Pearson's correlations were undertaken to investigate the significance and strength of the association between hop test LSIs.

RESULTS

Significant differences were observed across hop LSIs (p<0.0001). Mean LSIs for the SHD (95.0%), 6MTH (95.0%), THD (96.1%) and TCHD (95.3%) were ≥90% and significantly greater (p<0.05) than the MHD (87.3%), LHD (87.5%), SLCMJ (83.4%) and TSHT (86.5%), which were all <90%. The LSI for the SLCMJ was significantly lower (p<0.05) than all other hop tests. While significant correlations existed across the majority of hop LSIs, the strongest correlations existed between the SHD, THD and TCHD (r=0.70-0.80), and lowest correlations between the TSHT and the other hop tests (r=0.26-0.49).

CONCLUSIONS

The LHD, MHD and TSHT, as well as the SLCMJ in particular, were best able to demonstrate functional limb asymmetry in patients following ACLR. These hop measures should be incorporated into hop test batteries, if the purpose is to detect the presence of lingering functional deficits.

LEVEL OF EVIDENCE

Level 3.

Comparison of muscle strength and neuromuscular control up to 1 year after anterior cruciate ligament reconstruction between patients with dominant leg and non-dominant leg injuries

BACKGROUND

There has not been an investigation to determine whether leg dominance affects the recovery of quadriceps and hamstring strength, muscle reaction time (acceleration time, AT), and postural stability after anterior cruciate ligament (ACL) reconstruction in recreational-level athletic patients.

METHODS

A total of 100 patients with isolated ACL injuries (58 patients had dominant leg injuries; 42 patients had non-dominant leg injuries) participated. All patients received an anatomical single-bundle ACL reconstruction using an auto-hamstring tendon graft without preoperative rehabilitation. Leg dominance was defined as the kicking leg. The quadriceps and hamstring strength, AT, and postural stability (overall stability index (OSI)) of both legs were assessed at three different time points (preoperative, 6 months, 12 months), using an isokinetic dynamometer and postural stabilometry system.

RESULTS

All patients in both groups showed gradual improvement in quadriceps and hamstring muscle strength in the operated legs up to 1 year postoperatively. However, the mean value of quadriceps strength was lower in the operated non-dominant leg than the operated dominant leg 6 months postoperatively (P = 0.048). The AT and OSI of the operated legs in both groups recovered significantly 6 months postoperatively compared with their preoperative values; however, the AT and OSI values after 6 and 12 months were similar.

CONCLUSION

Quadriceps strength of the operated non-dominant leg was lower than that of the operated dominant leg 6 months postoperatively; however, the strength of the quadriceps and hamstring muscles was not different after 12 months between the operated dominant and non-dominant legs. Clinicians and physical therapists should consider these results during early rehabilitation and identify effective protocols to enhance quadriceps strength, especially in patients with non-dominant leg injuries.

Unilateral Plyometric Training is Superior to Volume-Matched Bilateral Training for Improving Strength, Speed and Power of Lower Limbs in Preadolescent Soccer Athletes

This study compared the effects of unilateral and bilateral plyometric training on strength, sprint performance and lower limb power. Sixty-eight preadolescent soccer athletes were randomly assigned to a unilateral plyometric training group (n=23), a bilateral plyometric training group (n=23) and a control group (n=22). Both plyometric training groups trained with equal volumes of unilateral or bilateral exercises for 15 minutes in each session, at which time the control group performed soccer-specific drills. Plyometric exercises were executed twice weekly for 10 weeks during the competitive season. The following tests were performed before and after the intervention: single-leg and double-leg countermovement jump, squat jump, horizontal jumps in different directions, maximal isometric strength of quadriceps and hamstrings, sprint performance, agility and balance. Unilateral plyometric training resulted in greater improvements compared to the control group in the following variables: hamstrings strength (ES: 0.91, p=0.037), 5m sprint time (ES: 0.93, p=0.004), single-leg countermovement jump (ES: 0.90, p=0.006), single- and double-leg squat jump (ES: 0.87, p=0.030 and ES: 0.73, p=0.067, respectively) and single-leg hop performance (ES: 1.01, p=0.004). The only tests where there was an improvement of BPT compared with the CG were the single-leg and double leg SJ (ES: 0.76, p=0.026; ES: 0.70, p=0.050). Quadriceps strength, side hop test, double-leg horizontal jump test, flamingo balance test and modified agility T-test were equally improved in all three groups (p<0.001). In conclusion, unilateral lower-limb plyometric training is more effective in increasing muscle strength and power in preadolescent soccer players when compared to bilateral training or soccer training alone.

Outcome of bone-patellar tendon-bone vs hamstring tendon autograft for anterior cruciate ligament reconstruction: A meta-analysis of randomized controlled trials with a 5-year minimum follow-up

BACKGROUND

Many systematic reviews have compared the short-term outcomes of anterior cruciate ligment (ACL)reconstruction with hamstring and patellar tendon autograft,but few differences have been observed. The purpose of this meta-analysis was to compare the medium-term outcome of bone-patellar tendon-bone and hamstring tendon autograft for anterior cruciate ligament reconstruction in terms of clinical function, knee stability, postoperativecomplications, and osteoarthritis changes.

METHODS

This meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The PubMed, Embase, and the Cochrane Library databases were searched from inception to November 2, 2019. This meta-analysis included only randomized controlled trials that compared BPTB and HT autografts for ACL reconstruction with a 5-year minimum follow-up. The Cochrane Collaboration's risk-of-bias tool was used to estimate the risk-of-bias for all included studies. RevMan 5.3 software was used to performed statistical analysis of the outcomes.

RESULTS

Fifteen RCTs, involving 1298 patients (610 patients in the BPTB group and 688 patients in the HT group) were included. In terms of clinical function, no significant difference was found in the objective International Knee Documentation Committee score (OR = 0.94, 95%CI: 0.64-1.37, P = .75), Lysholm knee score (MD = -2.26, 95%CI: -4.56 to 0.05, P = .06), return to preinjury activity level (OR = 1.01, 95%CI: 0.67-1.52, P = .96), and Tegner activity level (OR = 0.03, 95%CI: -0.36 to 0.41, P = .89). There was no statistically significant difference in the Lachman test (OR = 0.86, 95%CI: 0.5-1.32, P = .50), pivot-shift test (OR = 0.68, 95%CI: 0.44-1.06, P = .09), and side-to-side difference (MD = -0.32, 95%CI: -0.81 to 0.16, P = .19). As for postoperative complications and OA changes, there were no statistically significant difference in flexion loss (OR = 1.09, 95%CI: 0.47-2.54, P = .85) and OA changes (OR = 0.76, 95%CI: 0.52-1.10, P = .15), but we found significant differences in favor of the HT group in the domains of kneeling pain (OR = 1.67, 95%CI: 1.04-2.69, P = .03), anterior knee pain (OR = 2.90, 95%CI: 1.46-5.77, P = .002), and extension loss (OR = 1.75, 95%CI: 1.12-2.75, P = .01). There was a significant difference in favor of the BPTB group in the domain of graft failure (OR = 0.59, 95%CI: 0.38-0.91, P = .02).

CONCLUSIONS

Based on the results above, HT autograft is comparable with the BPTB autograft in terms of clinical function, postoperative knee stability, and OA changes, with a medium-term follow-up. The HT autograft for ACL reconstruction carries a lower risk of complications, such as anterior knee pain, kneeling pain, and extension loss, but an increased incidence of graft failure. Patients should be informed of the differences when deciding on graft choice with their physician.

Extended Version of a Test Battery for Visual Assessment of Postural Orientation Errors: Face Validity, Internal Consistency, and Reliability

OBJECTIVE

Undesirable postural orientation may be a risk factor for a second anterior cruciate ligament (ACL) injury. The purpose of this study was to evaluate face validity, internal consistency, and interrater reliability of an extended version of a previous test battery for visual assessment of postural orientation errors (POEs) in patients during the late phase of rehabilitation following ACL reconstruction (ACLR) (ie, when they have initiated jumping exercises).

METHODS

This study used a cross-sectional design. Fifty-three patients (45% women) in the late phase of ACLR rehabilitation performed 5 functional tasks of varying difficulty. POEs of the lower extremity and trunk were visually assessed from video and scored on a scale from 0 (good) to 2 (poor).

RESULTS

The side-hop and 2 new POEs (femur medial to shank, femoral valgus) were added to the test battery after expert focus group discussions. Internal consistency was calculated for all tasks (α = .712-.823). Interrater reliability showed fair to substantial agreement for femur medial to shank and femoral valgus during all tasks (K = 0.31-0.815) and almost perfect agreement for side-hop (intraclass correlation coefficient = 0.88).

CONCLUSIONS

The good internal consistency and reliability after adding side-hop, femur medial to shank, and femoral valgus suggests that this test battery is a suitable tool to quantify postural orientation throughout ACLR rehabilitation.

IMPACT

This test battery for visual assessment of POEs was evaluated in a heterogeneous group of patients in different phases of ACLR battery and can be used in clinical practice to measure POEs in patients with ACLR, including in the late phase of rehabilitation to return to sport. This study encourages research on more demanding tasks and additional POEs to cover the entire rehabilitation period after ACL injury or reconstruction.

Does Early Functional Mobilization Affect Long-Term Outcomes After an Achilles Tendon Rupture? A Randomized Clinical Trial

Background:

Functional deficits and health-related impairments are common after an Achilles tendon rupture (ATR). Rehabilitation protocols vary greatly, and few studies have allowed loading in combination with ankle motion immediately after surgery (ie, early functional mobilization [EFM]). It is unclear whether EFM may counteract the negative impact of ankle immobilization after an ATR.

Purpose:

The primary aim of this study was to assess the efficacy of EFM compared with standard treatment (ie, 2 weeks of unloading in a plaster cast followed by 4 weeks of weightbearing in an orthosis) regarding patient-reported and functional outcomes in patients with an ATR after acute operative repair. The secondary aim was to explore whether the occurrence of deep venous thrombosis (DVT) during the 2 postoperative treatments affected outcomes.

Study Design:

Randomized controlled trial; Level of evidence, 1.

Methods:

A total of 135 patients who underwent ATR repair, randomized to either EFM, including immediate postoperative loading and ankle motion, or standard treatment, were evaluated with functional tests and 5 self-administered outcome questionnaires at 6 and 12 months postoperatively.

Results:

At 6 months, the EFM group scored higher on the RAND 36-Item Health Survey (RAND-36) questionnaire subscales of general health and vitality (P < .05) compared with the control group. No significant differences between the groups were found on disease-specific questionnaires (Achilles tendon Total Rupture Score [ATRS] and Foot and Ankle Outcome Score [FAOS]). At 12 months, no significant differences on any of the patient-reported outcome measures or the functional heel-rise test were seen between the groups. The RAND-36 subscale of general health, however, exhibited higher values in the EFM group (82.6 ± 16.9) than the control group (77.1 ± 17.0) (P = .051) at 12 months after the injury. Patients sustaining DVT postoperatively had lower self-reported outcomes on the ATRS, FAOS, and RAND-36 questionnaires at 6 and 12 months compared with patients not having sustained DVT (all P < .05).

Conclusion:

This study demonstrated that an accelerated postoperative protocol with immediate loading and ankle motion resulted in better general health and vitality at 6 months. However, there were no differences between the groups in the recovery of heel-rise function. Future studies should focus on the means to reduce the risk of DVT to improve patient outcomes after ATR.

Registration:

NCT02318472 (ClinicalTrials.gov identifier).

Prevention of Anterior Cruciate Ligament Injuries in Competitive Adolescent Alpine Skiers

Anterior cruciate ligament (ACL) injury is one of the most serious injuries among Swedish alpine ski high school students. An ACL injury forces the skier to stop skiing for several months, and some skiers even have to give up their skiing career. Therefore, an ACL injury prevention program might play an important role for alpine skiers. In the present study ski high school students have been followed in terms of ACL injuries during 1-2 ski seasons between 2006/2007 and 2012/2013. Alpine skiers studying at the Swedish ski high schools during the ski seasons 2011/2012 and 2012/2013 received a specific ACL injury prevention program (n = 305), while alpine skiers who attended a Swedish ski high school between the ski seasons 2006/2007 and 2010/2011 served as controls (n = 431). The prevention program was based on earlier studies and included indoor and outdoor exercises on snow focusing on core stability and neuromuscular control. Alpine skiing is an equilateral sport. Therefore, the goal of the prevention was to encourage the skiers to practice these exercises in order to perform equally good on both legs. The outcome measure consisted of the number and incidence of ACL injuries. The 2 years of prevention resulted in 12 ACL injuries (3.9%) compared with 35 ACL injuries during the control period (8.1%). The absolute risk rate showed a decreased incidence rate of -0.216 [CI -0.001-(-0.432)]/100 months attending a ski high school in favor of the intervention group. A prevention program focusing on the skier's ability to perform neuromuscular exercises equally good on both legs led to a reduction of ACL injuries.

Differences Between Long Distance Road Runners and Trail Runners in Achilles Tendon Structure and Jumping and Balance Performance

BACKGROUND

Load and joint kinematics change with differences in running surface. Running regularly on trails compared to roads might influence the load on the Achilles tendon and its adaptations, along with other factors such as balance, strength, and proprioception.

OBJECTIVE

To investigate Achilles tendon structure and functional tests in road and trail runners.

DESIGN

Cross-sectional study.

SETTING

Laboratory, sport sciences college.

PARTICIPANTS

The study included 26 road and 17 trail runners who run at least three times per week with a minimum of 20 km per week and who participated in running competitions over the preceding 2 years.

METHODS

Each participant was examined for Achilles tendon structure (via ultrasound tissue characterization [UTC] imaging) and underwent functional tests in addition to completing a demographic questionnaire.

MAIN OUTCOME MEASUREMENTS

The percentages of echo types I, II, III, and IV (degree of structural homogeneity) within the tendon, tendon length and width, tendon cross-sectional area (via UTC imaging); Ankle inversion movement discrimination ability (via Active Movement Extent Discrimination Apparatus device); dynamic postural balance (via Y balance test); jumping performance (by Triple hop distance test); and Hip muscle abduction muscle strength (by hand-held dynamometry).

RESULTS

Percentage of echo type I was significantly lower while echo type II was higher in the road group compared with the trail group (67.3% type I and 28.9% type II in the road group compared with 74.1% type I and 22.1% type II in the trail group, P < .001). No differences between genders were found and no significant differences between groups were found for the other tests.

CONCLUSION

Tendon integrity as examined with UTC is different between road and trail runners. This suggests an influence of running surface on Achilles tendon structure. This difference was not reflected in other tests, thus the influence of tendon structure on function needs further examination.

Association Between Isokinetic Knee Strength and Perceived Function and Patient Satisfaction With Sports and Recreational Ability After Matrix-Induced Autologous Chondrocyte Implantation

Background:

Returning to a sound level of activity after matrix-induced autologous chondrocyte implantation (MACI) is important to patients. Evaluating the patient’s level of satisfaction with his or her sports and recreational ability is critical.

Purpose:

To investigate (1) satisfaction with sports and recreational ability after MACI and (2) the role that knee strength plays in self-reported knee function and satisfaction.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

Isokinetic knee strength was assessed in 97 patients at 1, 2, and 5 years after MACI to calculate hamstrings-quadriceps ratios and peak knee extensor and flexor torque limb symmetry indices (LSIs). The Sports and Recreation subscale of the Knee injury and Osteoarthritis Outcome Score (KOOS Sports/Rec) was completed. A satisfaction scale was used to evaluate how satisfied the patients were with their ability to return to recreational activities and their ability to participate in sport. Associations between knee strength LSI, KOOS Sports/Rec, and satisfaction with recreational and sporting activities were assessed through use of multivariable linear and logistic regression, with adjustment for confounders. Mediation analysis was conducted to assess the extent to which self-reported knee function mediated associations between strength LSI and satisfaction.

Results:

Satisfaction with the ability to return to recreational activities was achieved in 82.4%, 85.6%, and 85.9% of patients at 1, 2, and 5 years, respectively, and satisfaction with sports participation was achieved in 55.7%, 73.2%, and 68.5% of patients at 1, 2, and 5 years, respectively. Knee extension torque LSIs were associated with KOOS Sports/Rec after adjustment for confounders over 1, 2, and 5 years (5-year regression coefficient, 6.0 points; 95% CI, 1.4-10.7; P = .012). KOOS Sports/Rec was associated with the likelihood of being satisfied at all time points (recreation: 5-year adjusted odds ratio [OR], 2.26; 95% CI, 1.48-3.46; P < .001; and sports: 5-year adjusted OR, 1.98; 95% CI, 1.47-2.68; P < .001). In a multivariable mediation model, the knee extension torque LSI was associated with satisfaction directly (standardized coefficient, 0.16; 95% CI, 0.03-0.28; P = .017) and indirectly via KOOS Sports/Rec (standardized coefficient, 0.19; 95% CI, 0.01-0.38; P = .027), the latter representing 55% of the total association of knee extension torque LSI with satisfaction.

Conclusion:

Knee extensor symmetry was associated with satisfaction in recreational and sporting ability, both directly and indirectly, via self-reported sports and recreation–related knee function. Restoring strength deficits after MACI is important for achieving optimal outcomes.

Test-retest reliability and discriminative ability of forward, medial and rotational single-leg hop tests

BACKGROUND

Single-leg hop tests are commonly performed in the forward direction to evaluate functional performance. However, athletes move in multiple directions during pivoting sports. The first aim of this study was to examine test-retest reliability of single-leg hop tests in the forward, medial and rotational direction in non-injured athletes. Second, the discriminative ability to detect leg asymmetries with these hop tests in anterior cruciate ligament (ACL) reconstructed athletes was determined.

METHODS

Sixteen recreational non-injured participants (eight females, eight males; 22.4 ± 1.9 years) were tested twice (one-week interval) and performed the single hop for distance (SH), triple hop for distance (TH), medial side triple hop for distance (MSTH) and 90° medial rotation hop for distance (MRH). Intraclass correlation coefficients (ICCs), standard errors of measurement (SEM) and smallest detectable differences (SDD) were calculated. Discriminative ability was determined in 32 ACL-reconstructed participants (four females, 28 males; 24.4 ± 4.6 years; six months postoperative) who performed the same hop tests once.

RESULTS

The ICCs ranged between 0.93 and 0.98. The SEM and SDD were respectively 2.6-4.1% and 7.2-11.3% of the mean hop distance of the group. The proportion (%) of ACL-reconstructed participants passing the ≥90% limb symmetry cut-off was 62.5 (SH), 59.4 (TH), 40.6 (MSTH) and 46.9 (MRH).

CONCLUSION

Excellent test-retest reliability of forward, medial and rotational hop tests was found. This allows clinicians to make informed interpretations of changes in hop test distances when retesting athletes. Medial and rotational hop tests are more likely to show limb asymmetries in ACL-reconstructed participants compared to forward hop tests.

Contact times of change-of-direction manoeuvres are influenced by age and the type of sports: a novel protocol using the SpeedCourt® system

PURPOSE

Side-to-side asymmetry in side-cutting manoeuvres is a known risk factor for severe knee injury. Potential leg asymmetry during ground contact times of different change-of-direction manoeuvres was evaluated in athletes by means of the recently developed SpeedCourt^® system. The hypotheses were that ground contact times and the limb symmetry index are affected by age and the type of sports.

METHODS

One-hundred and sixty-five athletes (149 men, 16 women, age 16.5 ± 5.1) of popular team sports such as football, team handball and baseball were assessed by means of three different tests [side-hop, lateral change-of-direction (COD) and diagonal COD] using the SpeedCourt^® system. Analysis included the factors age, sex, type of sports, ground contact time, leg symmetry index and limb dominance.

RESULTS

During lateral but not diagonal COD tests, football players had shorter contact times than players of team handball (p = 0.026) and baseball (p = 0.015) of the same age group. The side-hop tests yielded differences in the leg symmetry index between players < 16 years and players > 16 years (p < 0.01). Mean ground contact time differed in each of the side-hop, lateral COD and diagonal COD tests (143.5 ± 20.0 vs. 256.2 ± 66.1 vs. 320.4 ± 55.0). Contact times and test durations of side-hop, lateral COD and diagonal COD tests were shorter for older players (p < 0.01).

CONCLUSIONS

Ground contact times of side-hop and change-of-direction manoeuvres are influenced by age, the type of sports and limb dominance. Such information is fundamental for future sports medicine research and needs to be considered in pre-season screening or when used as a criterion for return-to-competition of players with previous severe knee injury. Assessment of change-of-direction manoeuvres should be included in future return-to-competition test batteries.

LEVEL OF EVIDENCE

III.

Single-leg vertical jump test as a functional test after anterior cruciate ligament reconstruction

BACKGROUND

The aim of this study was to identify the correlations between the single-leg vertical jump (SLVJ) test and subjective and objective tests which were used widely for determining return-to-sports (RTS) after anterior cruciate ligament reconstruction (ACLR).

METHODS

Seventy-five patients (29.5 ± 9.2 years) who underwent ACLR between May 2012 and Jan 2014 were included. Subjective knee scoring systems including subjective International Knee Documentation Committee (IKDC) score, Lysholm score, Tegner activity scale, and ACL-Return to Sports after Injury (ACL-RSI) scale were assessed. Objective tests were also performed.

RESULTS

The limb symmetry index (LSI) for SLVJ test and single-leg hop for distance (SLHD) test was 89.4 ± 14.9% and 90.7 ± 11.7%. LSI for SLVJ test was correlated to subjective IKDC scores (r = 0.26, P = 0.024), Tegner activity scale (r = 0.64, P < 0.001), ACL-RSI scale (r = 0.61, P < 0.001), LSI for SLHD (r = 0.45, P < 0.001), Co-contraction (r = -0.57, P < 0.001), Shuttle run (r = -0.52, P < 0.001), and Carioca (r = -0.54, P < 0.001) tests. In isokinetic strength tests, extensor peak torque (r = 0.30, P = 0.009) and extensor strength deficit (r = -0.41, P < 0.001) were correlated with LSI for SLVJ test.

CONCLUSION

There were considerable correlations between SLVJ test and subjective IKDC scores, Tegner activity scale, ACL-RSI scale, isokinetic extensor muscle strength, and all other functional tests. SLVJ test could be used conveniently to determine RTS after ACLR in outpatient clinics.

LEVEL OF EVIDENCE

Level IV, case series.

Operative Repair of Medial Patellofemoral Ligament Injury Versus Knee Brace in Children With an Acute First-Time Traumatic Patellar Dislocation: A Randomized Controlled Trial

BACKGROUND

A lateral patellar dislocation (LPD) is the most common traumatic knee injury with hemarthrosis in children. The redislocation rate is high. Varying operative and nonoperative treatments have been advocated with no consensus on the best treatment.

PURPOSE

(1) To evaluate if arthroscopic-assisted repair of the medial patellofemoral ligament (MPFL) in patients with an acute first-time traumatic LPD would reduce the recurrence rate and offer better objective/subjective knee function compared with a knee brace without repair. (2) To study the presence of anatomic patellar instability risk factors (APIFs) and their association with a redislocation.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

This was a prospective series of 74 skeletally immature patients aged 9 to 14 years (38 girls and 36 boys; mean age, 13.1 years) with a first-time traumatic LPD, with clinical examinations, radiographs, magnetic resonance imaging, and diagnostic arthroscopic surgery performed within 2 weeks of the index injury. The child was randomized to either (1) a knee brace (KB group) for 4 weeks and physical therapy or (2) arthroscopic-assisted repair (R group) of the MPFL with anchors, 4 weeks with a soft cast splint, and physical therapy. The follow-up time was 2 years.

RESULTS

The redislocation rate was significantly lower in the R group than in the KB group at final follow-up: 8 patients (22%) versus 16 patients (43%), respectively ( P = .047). The Knee injury and Osteoarthritis Outcome Score for children sport/play and quality of life subscales had lower scores in the R group compared with the KB group; the significant differences were among those with redislocations. The mean Kujala score was excellent in the KB group (95.9) and good in the R group (90.9). An impaired Limb Symmetry Index (median, 83%) for concentric quadriceps torque at 90 deg/s was found only in the R group. Eighty-one percent of the study patients had ≥2 APIFs. Trochlear dysplasia (trochlear depth <3 mm) had the highest odds ratio for redislocations (2.35 [95% CI, 0.69-8.03]), with no significant association between APIFs and a redislocation.

CONCLUSION

Operative repair of an MPFL injury in the acute phase in skeletally immature children with a primary traumatic LPD significantly reduced the redislocation rate but did not improve subjective or objective knee function compared with a knee brace without repair. The majority of the patients in both groups were satisfied with their knee function. There was a high representation of APIFs, which needs to be considered when evaluating the risk of redislocations. Registration: ISRCTN 39959729 (Current Controlled Trials).

Partial Anterior Cruciate Ligament Ruptures: Advantages by Intraligament Autologous Conditioned Plasma Injection and Healing Response Technique-Midterm Outcome Evaluation

The historical treatment options for partial anterior cruciate ligament (ACL) ruptures were conservative therapy or ACL reconstruction by injured bundle or entire ACL replacement. In awareness of the regenerative potential of biologic agents such as mesenchymal stem cells or platelet rich plasma (PRP), the healing response technique was developed to preserve the injured ACL with better outcomes than the conservative therapy. Further improvement of this technique seems to be obtained by the additional application of PRP products. Thus, the aim of this study was to evaluate the midterm outcome after intraligament autologous conditioned plasma (ACP) by a clinical, scoring, and functional performance assessment. 42 patients were evaluated in this study. The failure rate was 9.5%. Outcome evaluation showed good to excellent results. The scores were IKDC subjective 83.2 (SD 14.5), Lysholm 85.5 (SD 15.5), Tegner 4.7 (SD 1.7), and Cincinnati 85.4 (SD 15.5) after a mean follow-up of 33 months. Clinical examination showed stable Lachman test, negative pivot shift phenomenon, and a significant reduction in AP-laxity compared to preoperative status (rolimeter preoperative: 1.9 (SD1.4); postoperative 0.6 (SD1.8), p=0.001) in all patients. Functional performance testing showed no significant differences between the injured and healthy side. Return to sport was achieved after a mean of 5.8 months (SD 3.6) in 71.1% of the included patients. In summary, this new treatment option revealed in midterm follow-up promising results to treat partial ACL lesions with a reduced need for conversion to ACL reconstruction and with a high percentage of return to preinjury sport activity.

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.

Risk Factors for Anterior Cruciate Ligament Injury in Competitive Adolescent Alpine Skiers

Background:

There is a high risk for anterior cruciate ligament (ACL) injuries in alpine skiers. To reduce or try to prevent these injuries, intrinsic and extrinsic risk factors need to be identified.

Purpose:

To identify possible intrinsic and extrinsic ACL injury risk factors among competitive adolescent alpine skiers.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

Between 2006 and 2009, a cohort of 339 alpine ski students (176 male, 163 female) from Swedish ski high schools were prospectively observed in terms of ACL injuries. First-time ACL injuries were recorded. In September, prior to each ski season, the skiers were clinically examined according to a specific knee protocol.

Results:

Overall, 11 male and 14 female skiers sustained a total of 25 first-episode ACL injuries. The majority of injuries occurred in the left knee (P < .05). Skiers who had participated in alpine skiing for >13 years (hazard ratio, 0.83; 95% CI, 0.68-1.00; P < .05) had a reduced risk of sustaining an ACL injury. Eighteen ACL injuries occurred during training, 12 in the technical discipline of giant slalom, and 8 in slalom. Fourteen skiers reported not to be fatigued at all at the time of injury, and 8 skiers reported that they were somewhat fatigued.

Conclusion:

ACL injuries occurred more often in the left knee than the right. This should be taken into consideration in the design of ACL injury prevention programs. Those who reported a higher number of active years in alpine skiing showed a reduced risk of sustaining an ACL injury. No other factor among those studied could be identified as an independent risk factor for ACL injury.

The effect of targeted exercise on knee-muscle function in patients with persistent hamstring deficiency following ACL reconstruction - study protocol for a randomized controlled trial

BACKGROUND

Anterior cruciate ligament (ACL) reconstruction, using hamstring auto-graft is a common surgical procedure, which often leads to persistent hamstring muscle-strength deficiency and reduced function. The purpose of this randomized controlled trial (RCT) is to investigate the effect of a combined, progressive, strength and neuromuscular exercise intervention on knee muscle strength, functional capacity and hamstring muscle-tendon morphology in ACL-reconstructed patients with persistent hamstring muscle-strength deficiency compared with controls.

METHODS/DESIGN

The study is designed as a multicenter, parallel-group RCT with balanced randomization (1:1) and blinded outcome assessments (level of evidence: II) and will be reported in accordance with the CONSORT Statement. Fifty ACL-reconstructed patients (hamstring auto-graft) with persistent limb-to-limb knee-flexor muscle-strength asymmetry at 12-24 months' post surgery, will be recruited through outpatient clinics and advertisements. Patients will be randomized to a 12-week progressive, strength and neuromuscular exercise group (SNG) with supervised training twice weekly or a control intervention (CON) consisting of a home-based, low-intensity exercise program. Outcome measures include between-group change in maximal isometric knee-flexor strength (primary outcome) and knee-extensor muscle strength, hamstring-to-quadriceps strength ratios of the leg that has been operated on and Knee injury and Osteoarthritis Outcome Score (KOOS) (secondary outcomes). In addition, several explorative outcomes will be investigated: The International Knee Documentation Committee Subjective Knee Form (IKDC), the Tegner Activity Score, rate of force development (RFD) for the knee flexors and extensors, tendon regeneration and potential muscle hypertrophy at graft harvest site evaluated by magnetic resonance imaging (MRI), postural control, kinetic/kinematic gait characteristics and knee-related functional capacity.

DISCUSSION

This RCT is designed to investigate the effect of combined, progressive-resistance and neuromuscular exercises on knee-flexor/extensor strength, in the late rehabilitation phase following ACL reconstruction. Reduced hamstring strength represents a potential risk factor for secondary ACL rupture and accelerated progression of osteoarthritis. If deemed effective, the intervention paradigm introduced in this study may help to improve current treatment strategies in ACL-reconstructed patients.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT02939677 (recruiting). Registered on 20 October 2016.

Clinician-Friendly Physical Performance Tests for the Knee

Reference:  Hegedus EJ, McDonough S, Bleakley C, Cook CE, Baxter GD. Clinician-friendly lower extremity physical performance measures in athletes: a systematic review of measurement properties and correlation with injury. Part 1: the tests for knee function including the hop tests. Br J Sports Med. 2015;49(10):642-648.

CLINICAL QUESTION

  Do individual physical performance tests (PPTs) used as measures for lower extremity function have any relationship to injuries in athletes aged 12 years or older?

DATA SOURCES

  Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to locate articles. The authors searched PubMed, EMBASE, and SPORTDiscus, in addition to searching by hand. The search strategy combined the terms athlete, lower extremity, and synonyms of performance test with the names of performance tests.

STUDY SELECTION

  Studies were included if they involved a test that met the operational definition for a PPT. The included studies assessed components of sport function (eg, speed, agility, and power), determined readiness for return to sport, or predicted injury to the lower extremity. All PPT measures could be performed on the field, courtside, or in a gym with affordable, portable, and readily available equipment. Studies were excluded if they made use of 3-dimensional motion capture, force platforms, timing gates, treadmills, stationary bikes, metabolic charts, or another nonportable, costly testing device. Athletes were categorized on the Tegner Scale at a minimum of level 5, which is the lowest level that still encompasses competitive athletes. Studies were included if 50% or more of the participants were rated above 5 on the Tegner Scale. Studies were excluded if the sole purpose was to judge movement quality or range of motion. Studies were selected if they identified the knee or a knee injury as a focal point of the paper.

DATA EXTRACTION

  The Consensus-Based Standards for the Selection of Health Measurement Instruments (COSMIN) was used to critique the methodologic quality of each paper with a 4-point Likert scale. The title and methods of each paper were extracted. Extracted data were summarized using ratings of unknown, conflicting, limited, moderate, and strong.

MAIN RESULTS

  An initial search revealed 3379 original articles for consideration. After initial review, 169 full-text articles were evaluated and 29 articles were included in the systematic review. Six tests were examined for the best evidence of methodologic quality: (1) 1-legged single hop for distance, (2) 1-legged triple hop for distance, (3) 6-m timed hop, (4) crossover hop for distance, (5) triple jump, and (6) 1-legged vertical jump. A summary of the methodologic properties of the 6 tests showed fair/poor reliability, fair/poor hypothesis testing, good criterion validity, and good/poor responsiveness. No tests predicted knee injury in athletes.

CONCLUSIONS

  Although numerous authors have evaluated PPTs at the knee, evidence for the measurement quality of these functional tests is limited and conflicting. Ample opportunity exists for researchers to further examine PPTs for the knee. Until more knowledge is gained about these PPTs, clinicians should exercise caution when making clinical decisions based on the results of these tests.

Can a Repeated Sprint Ability Test Help Clear a Previously Injured Soccer Player for Fully Functional Return to Activity? A Pilot Study

OBJECTIVE

To investigate the effects of fatigue induced by a repeated sprint ability (RSA) test on the neuromuscular responses of soccer players with a recent history of lower limb injuries (CH) and a matched control group in good fitness condition (GH).

DESIGN

This was a case-control study.

PARTICIPANTS

Nine CH and 9 GH.

INDEPENDENT VARIABLE

Allocation to CH or GH.

MAIN OUTCOME MEASURES

Each player was assessed for blood lactate concentration and jumping performance [squat jump (SJ) and countermovement jump (CMJ)] before/after RSA. Post-RSA rate of perceived exertion (RPE) was obtained. Receiver operating characteristic analysis was performed to calculate RSA sensitivity and specificity in distinguishing between CH and GH. Intraclass correlation coefficient was used to assess reliability.

RESULTS

No baseline differences were found for any variable. ΔSJ before/after RSA was -14 ± 2% and -5 ± 2% in CH and GH, respectively (P < 0.05). ΔCMJ before/after RSA was -15 ± 2% and -7 ± 2% in CH and GH, respectively (P < 0.05). ΔSJ-based and ΔCMJ-based (before/after RSA) area under curve (AUC) resulted in 0.90 ± 0.07 and 0.86 ± 0.09, respectively, with both AUCs differentiating between CH and GH with 77.78% sensitivity and 88.89% specificity. Pooled AUC resulted in 0.88 ± 0.06. Intraclass correlation coefficient was high (0.85/0.97).

CONCLUSIONS

Repeated sprint ability is a simple, low-cost field test potentially able to assist in clinical decision making for return to sport.

Two-Year Outcomes of a Randomized Trial Investigating a 6-Week Return to Full Weightbearing After Matrix-Induced Autologous Chondrocyte Implantation

BACKGROUND

Matrix-induced autologous chondrocyte implantation (MACI) has demonstrated encouraging outcomes in treating patients with knee cartilage defects. Postoperatively, the time required to attain full weightbearing (WB) remains conservative.

HYPOTHESIS

We hypothesized that patients would have no significant clinical or radiological differences or graft complications after an 8-week or 6-week return to full WB after MACI.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 37 knees (n = 35 patients) were randomly allocated to either an 8-week return to full WB that we considered current best practice based on the existing literature (CR group; n = 19 knees) or an accelerated 6-week WB approach (AR group; n = 18 knees). Patients were evaluated preoperatively and at 1, 2, 3, 6, 12, and 24 months after surgery, using the Knee Injury and Osteoarthritis Outcome Score, 36-Item Short Form Health Survey, visual analog pain scale, 6-minute walk test, and active knee range of motion. Isokinetic dynamometry was used to assess peak knee extension and flexion strength and limb symmetry indices (LSIs) between the operated and nonoperated limbs. Magnetic resonance imaging (MRI) was undertaken to evaluate the quality and quantity of repair tissue as well as to calculate an MRI composite score.

RESULTS

Significant improvements ( P < .05) were observed in all subjective scores, active knee flexion and extension, 6-minute capacity, peak knee extensor torque in the operated limb, and knee extensor LSI, although no group differences existed. Although knee flexor LSIs were above 100% for both groups at 12 and 24 months after surgery, LSIs for knee extensor torque at 24 months were 93.7% and 87.5% for the AR and CR groups, respectively. The MRI composite score and pertinent graft parameters significantly improved over time ( P < .05), with some superior in the AR group at 24 months. All patients in the AR group (100%) demonstrated good to excellent infill at 24 months, compared with 83% of patients in the CR group. Two cases of graft failure were observed, both in the CR group. At 24 months, 83% of patients in the CR group and 88% in the AR group were satisfied with the results of their MACI surgery.

CONCLUSION

Patients in the AR group who reduced the length of time spent ambulating on crutches produced comparable outcomes up to 24 months, without compromising graft integrity.

A Prospective Clinical and Radiological Evaluation at 5 Years After Arthroscopic Matrix-Induced Autologous Chondrocyte Implantation

BACKGROUND

While midterm outcomes after matrix-induced autologous chondrocyte implantation (MACI) are encouraging, the procedure permits an arthroscopic approach that may reduce the morbidity of arthrotomy and permit accelerated rehabilitation.

HYPOTHESIS

A significant improvement in clinical and radiological outcomes after arthroscopic MACI will exist through to 5 years after surgery.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

We prospectively evaluated the first 31 patients (15 male, 16 female) who underwent MACI via arthroscopic surgery to address symptomatic tibiofemoral chondral lesions. MACI was followed by a structured rehabilitation program in all patients. Clinical scores were administered preoperatively and at 3 and 6 months as well as 1, 2, and 5 years after surgery. These included the Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm knee scale (LKS), Tegner activity scale (TAS), visual analog scale for pain, Short Form-36 Health Survey (SF-36), active knee motion, and 6-minute walk test. Isokinetic dynamometry was used to assess peak knee extension and flexion strength and limb symmetry indices (LSIs) between the operated and nonoperated limbs. High-resolution magnetic resonance imaging (MRI) was performed at 3 months and at 1, 2, and 5 years postoperatively to evaluate graft repair as well as calculate the MRI composite score.

RESULTS

There was a significant improvement ( P < .05) in all KOOS subscale scores, LKS and TAS scores, the SF-36 physical component score, pain frequency and severity, active knee flexion and extension, and 6-minute walk distance. Isokinetic knee extension strength significantly improved, and all knee extension and flexion LSIs were above 90% (apart from peak knee extension strength at 1 year). At 5 years, 93% of patients were satisfied with MACI to relieve their pain, 90% were satisfied with improving their ability to undertake daily activities, and 80% were satisfied with the improvement in participating in sport. Graft infill ( P = .033) and the MRI composite score ( P = .028) significantly improved over time, with 90% of patients demonstrating good to excellent tissue infill at 5 years. There were 2 graft failures at 5 years after surgery.

CONCLUSION

The arthroscopically performed MACI technique demonstrated good clinical and radiological outcomes up to 5 years, with high levels of patient satisfaction.

Correlation between hip function and knee kinematics evaluated by three-dimensional motion analysis during lateral and medial side-hopping

[Purpose] Kinematic and kinetic characteristics of the limb during side-hopping and hip/knee interaction during this motion have not been clarified. The purposes of this study were to examine the biomechanical parameters of the knee during side hop and analyze its relationship with clinical measurements of hip function. [Subjects and Methods] Eleven male college rugby players were included. A three-dimensional motion analysis system was used to assess motion characteristics of the knee during side hop. In addition, hip range of motion and muscle strength were evaluated. Subsequently, the relationship between knee motion and the clinical parameters of the hip was analyzed. [Results] In the lateral touchdown phase, the knee was positioned in an abducted and externally rotated position, and increasing abduction moment was applied to the knee. An analysis of the interaction between knee motion and hip function showed that range of motion for hip internal rotation was significantly correlated with external rotation angle and external rotation/abduction moments of the knee during the lateral touchdown phase. [Conclusion] Range of motion for hip internal rotation should be taken into consideration for identifying the biomechanical characteristics in the side hop test results.

The Utility of Limb Symmetry Indices in Return-to-Sport Assessment in Patients With Bilateral Anterior Cruciate Ligament Reconstruction

BACKGROUND

The incidence of contralateral anterior cruciate ligament (ACL) injury after ACL reconstruction (ACLR) is high. Often, return-to-sport (RTS) tests of strength and functional hopping rely on limb symmetry indices (LSIs) to identify deficits, although the utility of these measures in athletes with bilateral ACL injuries is unknown.

PURPOSE/HYPOTHESIS

The aim of this study was to investigate if LSIs used as RTS criteria in female patients after unilateral ACLR were appropriate for female patients with bilateral ACL involvement. The hypothesis tested was that asymmetries with traditional LSI measures would be present in a population after unilateral ACLR but would not be present in a population with bilateral ACLR due to the lack of a healthy internal control limb.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 45 female subjects were classified into 3 groups: after second (contralateral) ACLR (ACLR-B; n = 15); after primary unilateral ACLR (ACLR-U; n = 15); and uninjured controls (CTRL; n = 15). After being cleared for RTS, each subject completed a single-legged hop for distance (SLHD), triple hop for distance (THD), and triple-crossover hop for distance (CHD) test, in addition to an isometric quadriceps strength test on both limbs. Means and LSI ([involved limb/uninvolved limb] × 100) were calculated for each test. Limb symmetry deficits were defined by LSI <90%.

RESULTS

Analysis of functional hop testing revealed a side × group interaction for SLHD (P = .001), THD (P = .019), and CHD (P = .04). Side-to-side differences were found in the ACLR-U group for all hop tests (P = .001-.003) and in the ACLR-B group for SLHD (P = .002) and THD tests (P = .024). No side-to side differences were seen in the CTRL group (P > .05). A side × group interaction was found for isometric quadriceps strength (P = .006), with lower LSI seen in the ACLR-U group (81% ± 17.6%) compared with the CTRL group (102.2% ± 10.8%) and the ACLR-B group (95.6% ± 24.9%). Although no interaction was seen, side-to-side differences were noted in the THD in the ACLR-U group (P = .013) and ACLR-B group (P = .024) and in the CHD in the ACLR-U group (P = .001). Despite absence of an LSI deficit, bilateral peak quadriceps strength in the ACLR-B group was comparable to the involved limb of the ACLR-U group and less than in the CTRL group (P = .012).

CONCLUSION

Both the ACLR-U and the ACLR-B groups demonstrated side-to-side deficits during functional hop tests; however, these deficits were not identified according to the clinically accepted LSI values of ≥90%, calling into question the efficacy of current RTS criteria. At the time of RTS, only individuals in the ACLR-U group demonstrated an altered LSI in quadriceps strength. Significantly lower quadriceps strength of both limbs in the ACLR-B group was seen compared with the CTRL group, despite no LSI deficits in quadriceps strength. Current use of LSIs during strength and performance tests may not be an appropriate means of identifying residual deficits in female patients after bilateral ACLR at time of RTS. Furthermore, a better indicator of strength performance in this population may need to include a comparison of strength performance values to the normative values of healthy controls.

Effects of 4 weeks preoperative exercise on knee extensor strength after anterior cruciate ligament reconstruction

[Purpose] After an anterior cruciate ligament injury and subsequent reconstruction, quadriceps muscle weakness and disruption of proprioceptive function are common. The purpose of this study was to examine the effects of a 4 weeks preoperative exercise intervention on knee strength power and function post-surgery. [Subjects and Methods] Eighty male patients (27.8±5.7 age), scheduled for reconstruction surgery, were randomly assigned to two groups, the preoperative exercise group (n=40) and a no preoperative exercise group (n=40). The preoperative exercise group participated in a 4-week preoperative and 12-week post-operative programs, while the no preoperative exercise group participated only in the 12-week postoperative exercise program. Isokinetic measured of quadriceps strength were obtained at 4 weeks before and 3 months after surgery. [Results] The knee extensor strength deficits measured at 60°/s and 180°/s was significantly lower in the preoperative exercise group compared with the no preoperative exercise group. At 3 months after surgery, the extensor strength deficit was 28.5±9.0% at 60°/sec and 23.3±9.0% at 180°/sec in the preoperative exercise group, whereas the no preoperative exercise group showed extensor strength deficits of 36.5±10.7% and 27.9±12.6% at 60°/sec and 180°/sec, respectively. The preoperative exercise group demonstrated significant improvement the single-leg hop distance. [Conclusion] Four week preoperative exercise may produce many positive effects post reconstruction surgery, including faster recovery of knee extensor strength and function, as measured by single-leg hop ability.

Subjective vs objective predictors of functional knee joint performance in anterior cruciate ligament-reconstructed patients--do we need both?

BACKGROUND

Associations between objective and subjective measures of knee function may facilitate rehabilitation in ACL-patients.

AIM

The aim of this study is to investigate if a test-battery of functional and/or muscle outcomes are associated with Knee osteoarthritis outcome score (KOOS) subscales (Sport/Rec and QOL) in ACL-reconstructed patients.

METHODS

23 hamstring auto-graft ACL-reconstructed men (mean age: 27.2 standard deviation 7.5 years, BMI: 25.4 standard deviation 3.2 time since surgery: 27 standard deviation 7 months) completed KOOS-questionnaire and an objective test-battery: (i) one-leg maximal jump for distance (OLJD), isometric maximal voluntary contraction (MVC) for (ii) knee extensors and (iii) flexors, and (iv) maximal counter movement jump (CMJ). Sagittal kinematic data were recorded during CMJ using a 6-camera Vicon MX system. Multilevel linear regression analysis was used to determine the strength of associations between KOOS parameters (Sport/Rec and QOL) that a priori were defined as dependent variables and 4 models of independent outcomes from the test-battery.

RESULTS

Moderate associations between OLJD and Sport/Rec (r(2)=0.26, p<0.01) and QOL (r(2)=0.26, p<0.01) were observed (Model 1). Adding knee extensor or flexor MVC to the analysis (Model 2) increased the strength of the associations (up to r(2)=0.53, p<0.01, and r(2)=0.31, p=0.02 for Sport/Rec and QOL, respectively). Adding both knee extensor and knee flexor MVC to the analysis (Model 3) did not improve the regression model and only minor increases were observed when including kinematic data of CMJ (Model 4).

CONCLUSION

Moderate-to-large proportion (31-53%) of the variation in KOOS was explained by OLJD and MVC which may add to design effective future rehabilitation interventions for ACL-patients.

Hop performance and leg muscle power in athletes: Reliability of a test battery

OBJECTIVES

To measure the absolute and relative reliability and the smallest real difference (SRD) in three commonly used hop tests, two leg-power tests and the single-leg squat jump.

DESIGN

Methodological study.

SETTING

Clinical setting.

PARTICIPANTS

Fourteen healthy athletes (seven women and seven men) were evaluated in a standardized test-retest design.

MAIN OUTCOME MEASURES

The Intra-class correlation coefficient (ICC2.1), Standard Error of Measurement (SEM) and SRD were calculated for the vertical jump, one-leg hop for distance, side-hop, single-leg squat jump and knee-flexion and knee-extension power tests.

RESULTS

All tests showed good to excellent ICC (0.84-0.98). The SEM (%) ranged between 3.4 and 11.1 for the four hop tests and between 8.1 and 12.4 for the leg-power tests. The SRD (%) for the hop tests ranged between 9.3 and 30.7 and for the three power tests between 22.4 and 34.3.

CONCLUSIONS

The absolute reliability of this test protocol showed good to excellent ICC values and measurement errors of approximately 10%. This instrument can be recommended for determining function in terms of power in healthy athletes or late in the rehabilitation process. The tests' methodological errors must be considered and caution should be taken regarding the standardization procedure during testing.

Functional performance testing for power and return to sports

Context:

Functional performance testing of athletes can determine physical limitations that may affect sporting activities. Optimal functional performance testing simulates the athlete’s activity.

Evidence Acquisition:

A Medline search from 1960 to 2012 was implemented with the keywords functional testing, functional impairment testing, and functional performance testing in the English language. Each author also undertook independent searches of article references.

Conclusion:

Functional performance tests can bridge the gap between general physical tests and full, unrestricted athletic activity.

Lower extremity muscle activation during functional exercises in patients with and without chronic ankle instability

OBJECTIVE

To determine whether individuals with chronic ankle instability (CAI) exhibit altered neuromuscular control as demonstrated by surface electromyography (EMG) amplitudes compared with healthy controls during single-limb eyes-closed balance, Star Excursion Balance Test, forward lunge, and lateral hop exercises.

DESIGN

A cross-sectional laboratory study.

SETTING

A research laboratory.

PARTICIPANTS

Fifteen young adults with CAI and 15 healthy controls.

INTERVENTIONS

The subjects performed functional exercises while surface EMG signals were recorded from the tibialis anterior, peroneus longus, lateral gastrocnemius, rectus femoris, biceps femoris, and gluteus medius.

MAIN OUTCOME MEASUREMENTS

Surface EMG amplitudes (root mean square area) for each muscle, muscles of the shank (distal 3 muscles), muscles of the thigh (proximal 3 muscles), and total muscle activity (all 6 muscles) of the lower extremity were analyzed and compared between the groups.

RESULTS

Individuals with CAI demonstrated significantly less EMG activity in the muscles of the lower extremity during all 4 functional exercises. Effect sizes for significant differences between groups ranged from -0.75 to -1.08, none of which had 95% confidence intervals that crossed zero, which indicates moderate to large decreases in muscle activity in patients with CAI compared with healthy controls.

CONCLUSIONS

Patients with CAI demonstrated decreased muscle activity of ankle, knee, and hip musculature during common functional rehabilitative tasks. Clinicians may benefit from implementing functional exercises for patients with CAI that target both distal and proximal muscles of the lower extremity.

Concurrent assessments of lower limb loading patterns, mechanical muscle strength and functional performance in ACL-patients--a cross-sectional study

BACKGROUND

Full recovery in muscle strength and functional performance may not be achieved after ACL-injury.

AIM

The aim of this study is to investigate loading patterns during jumping, muscle function and functional performance in ACL-reconstructed patients and to investigate the origin of between-limb asymmetry by means of a 3-dimensional movement analysis. Design is cross-sectional.

METHODS

23 ACL-reconstructed men (27.2±7.5 years, BMI: 25.4±3.2) 27±7 month post-surgery and 25 matched controls (27.2±5.4 years, BMI: 24.1±1.8) were included. Participants performed (i) bilateral and (ii) unilateral counter movement jumps (CMJ). A 3-D movement analysis was performed by a six-camera Vicon MX-system. Subsequently, jump height (JH), knee joint range of motion (ROM), peak and mean sagittal knee moments were analyzed (iii) one-leg maximal jump for distance was performed, and (iv) maximal unilateral isometric knee extensor and flexor strength (MVC) were measured using stabilized dynamometry.

RESULTS

No in-between group differences in age or BMI were observed. CMJ: Between-limb asymmetry ratios for ROM differed (p<0.01) between patients and controls in both types of CMJ (96.1% vs. 102.6% and 87.0% vs. 99.9% in bilateral and single-leg CMJs, respectively). Jump for distance: Patients demonstrated greater (p<0.01) asymmetry for jump length (92.9% vs. 98.6%). MVC: Asymmetry in hamstring MVC was greater (p<0.001) for patients than controls (77.4% vs. 101.3%).

CONCLUSIONS

ACL-patients showed reduced function of the operated leg~2 years post ACL-reconstruction, especially for hamstring MVC. Hamstrings are important protagonists to the ACL, thus representing a potential risk factor for secondary ACL-rupture and/or osteoarthritis.

Comparison of functional outcome measures after ACL reconstruction in competitive soccer players: a randomized trial

BACKGROUND

The choice of graft for anterior cruciate ligament (ACL) reconstruction remains controversial. Although many outcome studies comparing bone-patellar tendon-bone and semitendinosus and gracilis tendon grafts have been performed, most have not included tests of functional outcomes that challenge the graft. The objective of the current study was to compare the functional performances of soccer players after ACL reconstruction that was performed with either a bone-patellar tendon-bone or a semitendinosus and gracilis tendon graft.

METHODS

Forty-two soccer players with unilateral ACL injury were prospectively randomized to a bone-patellar tendon-bone group (BPTB group; twenty-one subjects) or a semitendinosus and gracilis tendon group (STG group; twenty-one subjects) and followed a rehabilitation protocol. At the time of return to sports, the patients were asked to execute strength, hop, and jump tests and the results were compared between the groups. Twenty-one healthy athletes were recruited as the control group to evaluate their performance of the same tests.

RESULTS

The limbs with the ACL reconstruction in the STG group had greater values for quadriceps torque as well as on the triple-hop, crossover-hop, and jump-landing test (p < 0.01), but the STG and BPTB groups showed similar results in terms of hamstrings peak torque and the results of two other hop tests (p > 0.05). Moreover, the subjects with ACL reconstruction had significantly lower values with regard to quadriceps and hamstrings peak torques and the results of the hop and jump tests compared with the healthy athletes (p < 0.01).

CONCLUSIONS

At the time of return to sports, the STG group had better performance in terms of quadriceps strength and the results of the triple-hop, crossover-hop, and jump-landing tests compared with the BPTB group. Compared with controls, soccer players who had undergone ACL reconstruction had less quadriceps and hamstrings strength and inferior hop performance and jump-landing strategy.

Análise comparativa do equilíbrio unipodal de atletas de ginástica rítmica

INTRODUÇÃO: A ginástica rítmica (GR) requer alto nível de qualidade física; assim, o bom desempenho é dependente da força e resistência muscular, coordenação motora e equilíbrio postural. OBJETIVO: Desenvolver uma análise comparativa do equilíbrio unipodal de atletas de GR. MÉTODOS: Foram avaliadas dez atletas de GR, do sexo feminino, por meio de uma plataforma de força em apoio unipodal e testes funcionais de equilíbrio (Side Hop Test e Figure of Eight Hop Teste). Para a plataforma, os parâmetros do Centro de Pressão (COP) nas direções anteroposterior e mediolateral foram utilizados para análise, enquanto para os testes funcionais, o tempo-segundos de performance. RESULTADOS: Diferença significativa (p = 0,01) foi encontrada entre os membros inferiores no parâmetro de frequência média na direção mediolateral, no qual o membro inferior não dominante apresentou maior estabilidade postural do que o dominante. Para os testes funcionais não houve diferença significativa entre os membros. CONCLUSÃO: A diferença encontrada no controle do equilíbrio na direção mediolateral pode estar relacionada às diferenças nas ações musculares da região do quadril, na qual durante a prática do esporte para estabilização, manutenção do tronco e execução de manobras com os membros inferiores estão presentes. Estes resultados indicam a necessidade de um programa de reequilíbrio e estabilização pélvica para as atletas analisadas no intuito de preservar a simetria muscular dos membros para o bom desempenho esportivo.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

Prognostic prospective cohort study, Level I.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Acute injuries to the posterolateral corner of the knee in children: a case series of 6 patients

BACKGROUND

Isolated avulsion fractures of the posterolateral structures (the popliteus tendon, the lateral collateral ligament, and the popliteofibular ligament) of the knee are rare.

PURPOSE

To describe the outcome after an isolated avulsion fracture at the femoral attachment of the posterolateral structures in skeletally immature patients and to communicate our clinical experience concerning diagnosis and treatment.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Six skeletally immature patients (mean age, 13.3 years; range, 12.6-13.7 years; 5 boys, 1 girl) with an avulsion fracture of the femoral attachment of the posterolateral structures were evaluated on average 5.1 years (range, 2.7-8.3 years) after the injury. Five patients were treated with open reduction and fixation of the fragment. The sixth patient was treated nonoperatively with cast immobilization. The evaluation was based on reassessment of radiographs and magnetic resonance imaging (MRI scans), registration of activity level, and examination of objective and subjective knee function.

RESULTS

The injury involved both the popliteus tendon and the lateral collateral ligament in 5 of the 6 cases. In the operated patients, the mean Lysholm knee score was 98 (range, 94-100) (0-100, with higher scores indicating a better outcome). The mean Knee injury and Osteoarthritis Outcome Score (KOOS) quality of life (QOL) was 80 (range, 50-100) (0-100, with higher scores indicating a better outcome). The range of motion and the KT-1000 arthrometer anterior laxity measurements were normal. The nonoperatively treated patient with involvement of both the popliteus tendon and the lateral collateral ligament suffered a bone bridge in the periphery of the femoral physis, causing a valgus deformity of the knee. An open wedge femoral osteotomy was performed. The Lysholm knee score was 80, and KOOS QOL was 25 at follow-up. The patient also had an extension deficit of 5° and a flexion deficit of 10°.

CONCLUSION

An avulsion of the femoral attachment of the posterolateral structures in skeletally immature patients may involve both the popliteus tendon and the lateral collateral ligament. Open reduction and fixation of the fragment gave a satisfactory outcome.