A two- and five-year follow-up of clinical outcome after ACL reconstruction using BPTB or hamstring tendon grafts: a prospective intervention outcome study

Bridge-Enhanced Anterior Cruciate Ligament Restoration: 6-Year Results From the First-in-Human Cohort Study

Background

Bridge-enhanced anterior cruciate ligament restoration (BEAR) combines suture repair of the anterior cruciate ligament (ACL) with an extracellular matrix implant plus autologous blood to facilitate native ACL healing.

Purpose/Hypothesis

The purpose of this study was to compare the 6-year follow-up outcomes of patients who underwent the BEAR procedure with those of a nonrandomized concurrent control group receiving autograft ACL reconstruction (ACLR) in the first-in-human safety study of the BEAR implant (BEAR I trial). Based on the 2-year results, it was hypothesized that isometric hamstring strength after the BEAR procedure would be greater than that after ACLR and that there would be no other differences in outcomes at 6 years.

Study Design

Cohort study, Level of evidence, 2.

Methods

Ten patients underwent BEAR and 10 received ACLR with a 4-stranded hamstring autograft. Outcomes assessed included the record of subsequent surgeries, the International Knee Documentation Committee (IKDC) Subjective Knee Score, IKDC physical examination grade, the Knee injury and Osteoarthritis Outcome Score, instrumented knee laxity, functional outcomes (ie, muscle strength assessments and hop testing), and qualitative magnetic resonance imaging assessment. Comparisons between treatments were based on computations of the mean differences and the associated 95% CIs.

Results

One patient in the BEAR group and 3 patients in the ACLR group were lost to follow-up. In the period between 2 and 6 years, 1 patient in each group underwent revision surgery. There were no differences between groups at the 6-year follow-up in any of the outcome measures except for isometric hamstring strength, which was approximately equal to that of the contralateral knee in the BEAR group and <44% of that in the contralateral knee in the ACLR group (P < .01).

Conclusion

This preliminary study suggests that the outcomes of BEAR and ACLR with a hamstring tendon graft may be similar at the 6-year follow-up and warrants investigation of the BEAR procedure in a larger cohort of patients.

Examining Postoperative Posterior Cruciate Ligament Index: A Structural Paradigm in Anterior Cruciate Ligament (ACL) Reconstructions With Hamstring Tendon Autograft

BACKGROUND

The current study aimed to compare the posterior cruciate ligament (PCL) index values of patients who underwent hamstring tendon (HT) autograft reconstruction due to an anterior cruciate ligament (ACL) tear. The comparison involved assessing these values in a similar cohort and evaluating the association between the alteration in the PCL index and functional results.

METHODS

Patients who were clinically diagnosed with a complete, unilateral ACL tear and underwent ACL reconstruction (ACLR) using HT autograft between January 2018 and January 2021 constituted the operated group (Group 1) of the study. The control group (Group 2) consisted of patients selected from a convenience sample without ACL rupture, meniscal lesion, or cartilage damage who underwent an MRI during an outpatient orthopaedic consultation for knee pain. The operated group was submitted for an MRI of the knee one year after the operation for any reason such as pain, graft healing, the presence of tunnel widening, or suspicion of re-rupture. The International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form and the Lysholm Scoring System were applied to the patients in the operated group in the preoperative and postoperative periods to evaluate their complaints, function, and participation in sports and to assess functional ability and functional capacity. A radiologist with five years of experience measured the PCL index in the sagittal section of an MRI. In the operated group, changes in PCL index, IKDC, and Lysholm values during the postoperative period were assessed, along with their correlation. Additionally, a comparison was made between the values of the operated group and the non-operated group.

RESULTS

No statistically significant correlation was found between the PCL index alteration and the functional score alteration (IKDC and Lysholm) in the operated group (p>0.05). In comparison to the non-operated group, the preoperative PCL index measures of the operated group were significantly lower (p: 0.000; p<0.05). The increase in the postoperative PCL index measurements of the operated group was similarly statistically significant (p: 0.000; p<0.05).

CONCLUSION

Although the PCL index appears to be a strong anatomical structural parameter in ACLR patients performing HT autograft in the postoperative period, its correlation with functional results is weak.

Risk Factors for Ipsilateral Versus Contralateral Reinjury After ACL Reconstruction in Athletes: A Systematic Review and Meta-analysis

Background

Anterior cruciate ligament (ACL) reinjury after ACL reconstruction (ACLR) can occur on the ipsilateral or contralateral side. Limited evidence exists regarding the difference between the incidence of reinjury to either knee, which is important in developing interventions to prevent ACL reinjury.

Purpose

To compare the reinjury rate of the ACL on the ipsilateral side versus the contralateral side in athletes after ACLR and investigate the risk factors that may cause different reinjury rates between the sides.

Study Design

Systematic review; Level of evidence, 4.

Methods

A systematic review was performed based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Studies that involved ACL reinjury in athletes after ACLR were reviewed. Considering several risk factors, including age and sex, a comparison of ACL reinjury incidence on the ipsilateral and contralateral sides was performed using a meta-analysis.

Results

Of the 17 selected studies, 3 were found to be at high risk of bias, and thus, 14 (n = 3424 participants) studies were included in the meta-analysis. In this athletic population, the contralateral ACL had a significantly higher rupture rate than the ipsilateral graft (risk ratio [RR], 1.41; P < .0001). Female athletes were found to have a greater risk of ACL reinjury on the contralateral versus the ipsilateral side (RR, 1.65; P = .0005), but different results were found in male athletes. (RR, 0.81; P = .21). There was no statistical difference in the incidence rate of ACL reinjury to either side in adolescent athletes (RR, 1.15; P = .28).

Conclusion

The contralateral ACL was more vulnerable to reinjury than the ipsilateral side in athletes after ACLR. Female athletes were more likely to reinjure their contralateral native ACL, while the same trend was not found in their male counterparts. The reinjury rate was comparable in both knees in adolescent athletes.

Bone-patellar tendon-bone versus two- and four-strand hamstring tendon autografts for ACL reconstruction in young adults: a Bayesian network meta-analysis

Bone-patellar tendon-bone (BPTB), two- and four-strand hamstring tendon (4SHT and 2SHT, respectively) are the most common autografts used for anterior cruciate ligament (ACL) reconstruction. The present study compared BPTB, 2SHT, and 4SHT for ACL reconstruction in terms of joint laxity, patient reported outcome measures (PROMs), rate of failure and anterior knee pain (AKP). The time to return to sport and the peak torque between the autografts were also compared. Finally, prognostic factors leading to worse outcomes were also investigated. It was hypothesized that all grafts yield similar proprieties in terms of joint laxity, patient reported outcome measures (PROMs) and rate of failure, but that the BPTB autograft causes a greater rate of anterior knee pain (AKP). The literature search was conducted. All clinical trials comparing BTPB and/or 2SHT, and/or 4SHT were accessed. Grafts other than BTPB and/or 4SHT and/or 2SHT were not considered. Articles reporting outcomes of allografts or synthetic grafts were not eligible, nor were those concerning revision settings. Articles reporting ACL reconstruction in patients with multi-ligament damage were also not eligible. Data from 95,575 procedures were retrieved. The median length of follow-up was 36 months. The median age of the patients was 27.5 years. With regard to joint laxity, similarity was found in terms of Lachman and Pivot shift tests between all three autografts. The BPTB demonstrated the greatest stability in terms of instrumental laxity. BPTB demonstrated the greatest PROMs. BPTB demonstrated the greatest rate of AKP, while AKP in 2SHT and 4SHT was similar. Concerning failure, statistically significant inconsistency was found (P = 0.008). The 4SHT demonstrated the quickest return to sport, followed by BPTB, and 2SHT. There was evidence of a negative association between the time span between injury to surgery, Lysholm score (P = 0.04), and Tegner scale (P = 0.04). Furthermore, there was evidence of a weak positive association between the time span between injury to surgery and return to sport (P = 0.01). BPTB may result in lower joint laxity, greater PROMs, and greater peak flexion torque compared to 2SHT and 4SHT autografts. On the other hand, BPTB reported the lowest peak extension torque and the greatest rate of AKP. Finally, a longer time span between injury and surgery negatively influences outcome.

Current trends in graft choice for primary anterior cruciate ligament reconstruction - part II: In-vivo kinematics, patient reported outcomes, re-rupture rates, strength recovery, return to sports and complications

Postoperative patient satisfaction after anterior cruciate ligament reconstruction (ACL-R) is influenced mainly by the degree of pain, the need for reoperation, and functional performance in daily activities and sports. Graft choice has shown to have an influence on postoperative outcomes after ACL-R. While patient reported outcomes measurements do not differ between graft options, evidence shows that normal knee kinematics is not fully restored after ACL-R with an increase in postoperative anterior tibial translation (ATT). Postoperative graft rupture rates seem to favor bone-patella-tendon-bone (BPTB) and quadriceps tendon (QT) autografts over HT or allografts. While return to sports rates seem comparable between different graft types, postoperative extensor strength is reduced in patients with BPTB and QT whereas flexion strength is weakened in patients with HT. Postoperative donor site morbidity is highest in BPTB but comparable between HT and QT. With all graft options having advantages and drawbacks, graft choice must be individualized and chosen in accordance with the patient.

Prospective and Randomized Clinical Evaluation of Hamstring Versus Patellar Tendon Autograft for Anterior Cruciate Ligament Reconstruction in Soccer Players

Background:

Anterior cruciate ligament (ACL) reconstruction is usually performed with autologous bone–patellar tendon–bone (PT) or hamstring tendon (HT) graft. There has been only 1 randomized clinical trial examining ACL reconstruction with these grafts specifically in soccer players, and more studies comparing these graft types within a homogenous cohort such as soccer athletes may better highlight differences in outcomes.

Purpose:

To compare the results of ACL reconstruction with PT versus HT autograft in soccer players and to evaluate objective and subjective outcomes.

Study Design:

Randomized controlled trial; Level of evidence, 1.

Methods:

A total of 62 professional or semiprofessional soccer players (mean age, 25.1 years) with ACL injury were randomized to undergo reconstruction with PT or HT autograft by a single orthopaedic surgeon (n = 31 in each group). Outcome measures were recorded preoperatively and at 2 years postoperatively. The primary outcome was the modified Cincinnati Knee Rating System, and secondary outcomes were the objective and subjective International Knee Documentation Committee scores, Lachman test, pivot-shift test, anterior drawer test, and Lysholm score. The following variables were also evaluated postoperatively: return to soccer, level at return, graft rerupture, postoperative complications, anterior knee pain, patellar tendinitis, difficulty sprinting, and loss of kicking power.

Results:

The PT and HT groups were homogenous in terms of age, sex distribution, injured side, and time from injury to surgery, and there was no difference between them on any preoperative outcome score. At 2 years postoperatively, there were no differences between the groups on any outcome score; however, there were significantly fewer patients with anterior knee pain in the HT group compared with the PT group (7 [22.6%] vs 15 [48.4%], respectively; P = .03). Two patients from each group (2/31; 6.5%) sustained rerupture.

Conclusion:

There were no differences between soccer players who underwent different types of ACL reconstruction with the exception of anterior knee pain, which was more frequent in players who underwent reconstruction with PT graft.

Registration: NCT02642692 (ClinicalTrials.gov).

Does sex affect second ACL injury risk? A systematic review with meta-analysis

OBJECTIVE

To determine sex-based differences in risk of a second ACL injury (overall and by laterality) following primary ACL reconstruction in athletes who are attempting to return to sport.

DESIGN

Systematic review with meta-analysis.

DATA SOURCES

Systematic search of five databases conducted in August 2019.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies reporting sex-based differences in the incidence of second ACL injury in athletes attempting to return-to-sports and who were followed for at least 1 year following primary ACL reconstruction.

RESULTS

Nineteen studies were included in this review, with seven studies excluded from the primary meta-analysis due to high risk of bias. The remaining 12 studies (n=1431 females, n=1513 males) underwent meta-analysis, with all 19 studies included in a sensitivity analysis. Total second ACL injury risk was 21.9% (females: 22.8%, males: 20.3%). Females were found to have 10.7% risk of an ipsilateral ACL injury and 11.8% risk of a contralateral ACL injury. Males were found to have 12.0% risk of an ipsilateral ACL injury and 8.7% risk of a contralateral ACL injury. No statistically significant differences were observed for total second ACL injury risk (risk difference=-0.6%, 95% CI -4.9 to 3.7, p=0.783, I²=41%) or contralateral ACL injury risk (risk difference=1.9%, 95% CI -0.5% to 4.4%, p=0.113, I²=15%) between sexes. Females were found to have a 3.4% absolute risk reduction in subsequent ipsilateral ACL injury risk compared with males (risk difference=-3.4%, 95% CI -6.7% to -0.02%, p=0.037, I²=35%).

CONCLUSION

Both sexes have >20% increased risk of experiencing a second ACL injury. Any difference in the absolute risk of either a subsequent ipsilateral or contralateral ACL injury between sexes appears to be small.

REGISTRATION

PROSPERO (CRD42020148369).

Health-Related Quality of Life in Former National Collegiate Athletic Association Division I Collegiate Athletes Compared With Noncollegiate Athletes: A 5-Year Follow-Up

CONTEXT

The effect of athletic participation on lifelong health among elite athletes has received increasing attention, as sport-related injuries can have a substantial influence on long-term health.

OBJECTIVE

To determine the current health-related quality of life (HRQoL) of former National Collegiate Athletic Association Division I athletes compared with noncollegiate athletes 5 years after an initial assessment.

DESIGN

Cohort study.

SETTING

Online survey.

PATIENTS OR OTHER PARTICIPANTS

From the former Division I athletes, 193 responses were received (response rate = 83.2%; 128 men, 65 women; age = 58.47 ± 6.17 years), and from the noncollegiate athletes, 169 surveys were returned (response rate = 75.1%; 80 men, 89 women; age = 58.44 ± 7.28 years).

MAIN OUTCOME MEASURE(S)

The independent variables were time (baseline, 5 years later) and group (former Division I athlete, noncollegiate athlete). Participants completed 7 Patient-Reported Outcomes Measurement Information System scales: sleep disturbance, anxiety, depression, fatigue, pain interference, physical function, and satisfaction with participation in social roles.

RESULTS

Sleep disturbance, depression, fatigue, pain, and physical function were significant for time × group interactions (P values < .05), with the largest differences seen in pain and physical function between groups at time point 2 (22.19 and 13.99 points, respectively). Former Division I athletes had worse scores for depression, fatigue, pain, and physical function at follow-up (P values < .05), with the largest differences seen on the depression, fatigue, and physical function scales (8.33, 6.23, and 6.61 points, respectively).

CONCLUSIONS

Because of the competitive nature of sport, the long-term risks of diminished HRQoL need to become a priority for health care providers and athletes during their athletic careers. Additionally, physical activity transition programs need to be explored to help senior student-athletes transition from highly structured and competitive collegiate athletics to lifestyle physical activity, as it appears that individuals in the noncollegiate athlete cohort engaged in more physical activity, weighed less, and had increased HRQoL.

[Mid-term effectiveness of anterior cruciate ligament revision]

OBJECTIVE

To assess the mid-term effectiveness of anterior cruciate ligament (ACL) revision and to analyze the relevant factors that may affect the surgical outcomes.

METHODS

The clinical data of 24 patients who underwent ACL revision surgery between April 2009 and July 2018 and were followed up for more than 2 years were retrospectively analyzed. There were 20 males and 4 females with a median age of 30 years [interquartile distance (IQR) was (25, 36) years]. The median body mass index was 24.45 kg/m 2 and IQR was (22.93, 25.93) kg/m 2. The median time between ACL revision and reconstruction was 41 months and IQR was (15, 85) months. The direct cause of the failure of reconstruction surgery included 14 cases of trauma, 8 cases of no obvious cause, and 2 cases of infection. During the revision operation, 14 patients had a poor bone tunnel position, all of which were drilled with new tunnels, the remaining 10 patients were freshly modified on the basis of the original bone tunnel. Seventeen patients used autogenous tendon revision, 7 patients used LARS ligament; 16 patients had cartilage injury. The Lysholm score, the International Knee Documentation Committee (IKDC) score, and the Tegner sports rating score were used for functional evaluation before operation, at 1 year after operation, and at last follow-up. The Likert satisfaction score was recorded at last follow-up.

RESULTS

Patients were followed up with a median time of 47 months and IQR was (32, 61) months. The Lysholm score, IKDC score, and Tegner sports rating score were significantly improved at 1 year after operation and at last follow-up when compared with preoperative scores ( P<0.05). There was no significant difference between at last follow-up and at 1 year after operation ( P>0.05). At last follow-up, the median Likert satisfaction score was 4.0 and IQR was (3.0, 4.5). According to the presence or absence of cartilage damage and the type of graft, the above scores at last follow-up were compared between the groups, and the differences were not significant ( P>0.05). At last follow-up, 2 patients had graft fractures due to trauma again, and autogenous iliac bones were taken to fill the bone tunnel, and the second stage was revised; the rest of the patients recovered satisfactorily.

CONCLUSION

With preoperative identification of the cause of ACL reconstruction failure, the stability and function of knee joint can be significantly improved by selecting appropriate bone tunnels and grafts during the revision and by active rehabilitation exercises.

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.

Hamstring autograft versus patellar tendon autograft for anterior cruciate ligament reconstruction, which graft has a higher contralateral anterior cruciate ligament injury rate?: A meta-analysis of 5561 patients following the PRISMA guidelines

BACKGROUND

Contralateral anterior cruciate ligament (CACL) injury is one of the devastating complications after anterior cruciate ligament (ACL) reconstruction. Whether the risk of CACL tear is related to graft selection remains controversial due to contradictory results in studies. There are no meta-analyses to compare which graft has a higher CACL injury rate. Hence, this meta-analysis was conducted to compare the incidence of the CACL injury after ACL reconstruction with bone-patellar tendon-bone (BPTB) autografts compared with hamstring (HT) autografts.

METHODS

A comprehensive search of literature published between 1980 and January 2020 was performed using MEDLINE, EMBASE, Web of Science, and the Cochrane Library databases. RevMan 5.3 software was used for meta-analysis. The overall risk ratio (RR) was calculated using a fixed- or random-effects. The heterogeneity among the included results was analyzed by chi-square test with significance set at P < .10, and the heterogeneity was quantitatively detected by I-square tests.

RESULTS

Fifteen prospective comparative studies met inclusion criteria. In the BPTB group, the CACL rupture rate ranged from 1.8% to 30%, with a pooled percentage of 8.5%. In the HT group, the CACL rupture rate ranged from 0% to 14.4%, with a pooled percentage of 3.3%. The overall CACL rupture rate was 3.1% and ranged from 1.1% to 27.1%, with a pooled percentage of 4.9%. The pooled results indicate that there was a statistical significant difference in CACL rupture risk rate between BPTB and HT autograft. (RR, 1.53; 95% CL, 1.21-1.91; P = .0004).

CONCLUSION

This review showed that patients undergoing primary ACL reconstruction with BPTB autograft were more likely to have CACL rupture than patients treated with HT autograft.

Is anterior cruciate ligament graft rupture (after successful anterior cruciate ligament reconstruction and return to sports) actually a graft failure or a re-injury?

PURPOSE

The objective of this study is to discuss the fact that whether graft rupture after successful anterior cruciate ligament (ACL) reconstruction surgery is due to graft failure or re-injury to the reconstructed ACL.

METHODS

In total, 340 sportspersons, meeting our inclusion criteria, were assessed for rupture of ipsilateral ACL graft and ACL injury of the contralateral knee. Patients with ipsilateral ACL graft rupture were labelled as group 1, while those with contralateral ACL injury were labelled as group 2. Both groups were compared for potential risk factors for ACL injury, and statistical analysis was performed to study whether the graft acted as an additional risk factor.

RESULTS

Of the 340 sportspersons, 25 patients suffered a total of 26 injuries. Ipsilateral graft rupture rate was 2.4% (8 of 340) at a mean follow-up of 25.5 ± 40.57 months, and the contralateral ACL injury rate was 5.3% (18 of 340) at a mean follow-up of 18.11 ± 19.97 months, with an overall re-injury rate of 7.6%. Both groups were comparable for risk factors for ACL injury: age ( p = 0.255), gender ( p = 0.534), mode of re-injury ( p = 0.523), level of sports activity, type of graft used ( p = 0. 918), graft diameter ( p = 0.607), duration from injury to index surgery ( p = 0.492), duration from index surgery to re-injury ( p = 0.638), timing of return to sports after index surgery ( p = 0.303), duration of sporting activity before second injury ( p = 0.657), and Tegner's level of sports activity ( p = 0.486).

CONCLUSION

Because the rate of contralateral ACL injury is higher than the ipsilateral graft rupture and the risk factors for ACL injury are comparable in both groups at a follow-up period, which is suggestive of ligamentization of the graft, we suggest that it might be an ACL re-injury rather than graft failure. Level of Evidence: Level III (Retrospective cohort study).

Hamstring muscle activation and morphology are significantly altered 1-6 years after anterior cruciate ligament reconstruction with semitendinosus graft

PURPOSE

Harvest of the semitendinosus (ST) tendon for anterior cruciate ligament reconstruction (ACLR) causes persistent hypotrophy of this muscle even after a return to sport, although it is unclear if hamstring activation patterns are altered during eccentric exercise. It was hypothesised that in comparison with contralateral control limbs, limbs with previous ACLR involving ST grafts would display (i) deficits in ST activation during maximal eccentric exercise; (ii) smaller ST muscle volumes and anatomical cross-sectional areas (ACSAs); and (iii) lower eccentric knee flexor strength.

METHODS

Fourteen athletes who had successfully returned to sport after unilateral ACLR involving ST tendon graft were recruited. Median time since surgery was 49 months (range 12-78 months). Participants underwent functional magnetic resonance imaging (MRI) of their thighs before and after the Nordic hamstring exercise (NHE) and percentage change in transverse (T2) relaxation time was used as an index of hamstring activation. Muscle volumes and ACSAs were determined from MRI and distal ST tendons were evaluated via ultrasound. Eccentric knee flexor strength was determined during the NHE.

RESULTS

Exercise-induced T2 change was lower for ST muscles in surgical than control limbs (95% CI - 3.8 to - 16.0%). Both ST muscle volume (95% CI - 57.1 to - 104.7 cm³) and ACSA (95% CI - 1.9 to - 5.0 cm²) were markedly lower in surgical limbs. Semimembranosus (95% CI 5.5-14.0 cm³) and biceps femoris short head (95% CI 0.6-11.0 cm³) volumes were slightly higher in surgical limbs. No between-limb difference in eccentric knee flexor strength was observed (95% CI 33 N to - 74 N).

CONCLUSION

ST activation is significantly lower in surgical than control limbs during eccentric knee flexor exercise 1-6 years after ACLR with ST graft. Lower levels of ST activation may partially explain this muscle's persistent hypotrophy post ACLR and have implications for the design of more effective rehabilitation programs.

LEVEL OF EVIDENCE

IV.

Anterior Cruciate Ligament Reconstruction in Young Females: A Systematic Review of Patellar Tendon Versus Hamstring Tendon Autografts

A systematic review was performed to compare patellar tendon-bone (BTB) and hamstring tendon (HS) autografts following anterior cruciate ligament reconstruction in young females, young patients, or females. One study compared BTB and HS in young females and found a lower rate of graft failure with BTB (P<.02). Of the 11 studies that made this comparison in females, 1 reported decreased laxity in females with BTB (P=.035). Of 4 studies comparing autografts in young patients, 1 reported a decreased rate of graft failure with BTB (P=.036). Further studies making this comparison specifically in young females are warranted. [Orthopedics. 2019; 42(3):e295-e304.].

Bridge-Enhanced Anterior Cruciate Ligament Repair: Two-Year Results of a First-in-Human Study

Background

Bridge-enhanced anterior cruciate ligament repair (BEAR) combines suture repair of the anterior cruciate ligament (ACL) with a specific extracellular matrix scaffold (the BEAR scaffold) that is placed in the gap between the torn ends of the ACL to facilitate ligament healing.

Purpose/Hypothesis

The purpose of this study was to report the 12- and 24-month outcomes of patients who underwent the BEAR procedure compared with a nonrandomized concurrent control group who underwent ACL reconstruction (ACLR) with an autograft. We hypothesized that the BEAR group would have physical examination findings, patient-reported outcomes, and adverse events that were similar to those of the ACLR group.

Study Design

Cohort study; Level of evidence, 2.

Methods

Ten patients underwent BEAR, and 10 underwent ACLR with a 4-stranded hamstring autograft. At 24 months, 9 of the 10 BEAR patients and 7 of the 10 ACLR patients completed a study visit. Outcomes reported included International Knee Documentation Committee (IKDC) subjective and objective results, knee anteroposterior (AP) laxity findings via an arthrometer, and functional outcomes.

Results

There were no graft or repair failures in the first 24 months after surgery. The IKDC subjective scores in both groups improved significantly from baseline (P < .0001) at 12 and 24 months, to 84.6 ± 17.2 in the ACLR group and to 91.7 ± 11.7 in the BEAR group. An IKDC objective grade of A (normal) was found in 44% of patients in the BEAR group and in 29% of patients in the ACLR group at 24 months; no patients in either group had C (abnormal) or D (severely abnormal) grades. Arthrometer testing demonstrated mean side-to-side differences in AP laxity that were similar in the 2 groups at 24 months (BEAR, 1.94 ± 2.08 mm; ACLR, 3.14 ± 2.66 mm). Functional hop testing results were similar in the 2 groups at 12 and 24 months after surgery. Hamstring strength indices were significantly higher in the BEAR group compared with the ACLR group (P = .0001).

Conclusion

In this small, first-in-human study, BEAR produced similar outcomes to ACLR with a hamstring autograft. BEAR may result in knee stability and patient-reported outcomes at 2 years sufficient to warrant longer term studies of efficacy in larger groups of patients.

Morphology of the patellar tendon and its insertion sites using three-dimensional computed tomography: A cadaveric study

BACKGROUND

To clarify, with three-dimensional (3D) images, the morphological properties of the patellar tendon and both of its insertion sites.

METHODS

Thirty-two human cadaveric left knees were evaluated, and 3D computed tomography images were created. These images were used to analyse the morphology of both insertion sites of the patellar tendon, and the width, length and thickness of each region of the patellar tendon.

RESULTS

The insertion sites of the patellar tendon on the patellar and tibial sides were V-shaped and crescent-shaped, respectively, with the respective bony apexes located at 44.5 ± 2.2% (standard deviation) and 35.5 ± 2.8% of the tendon width from its medial edge. The proximal, central and distal widths of the patellar tendon were 29.9 ± 2.7 mm, 27.3 ± 2.5 mm and 25.0 ± 2.4 mm, respectively. The length of the patellar tendon was shortest at 40.6% ± 6.7% of the central width and gradually became longer toward both edges. The patellar tendon was thickest in the central portion of 40-75% and gradually became thinner toward both edges.

CONCLUSIONS

The morphological properties of the patellar tendon and its insertion sites on both the patellar and tibial sides were consistent. These findings indicate that the characteristics of the bone-patellar tendon-bone graft markedly depend on the location from which it is harvested, and that these characteristics contribute to predicting the length, width and shapes of the bone plugs of the graft when performing bone-patellar tendon-bone surgery.

Increased knee laxity with hamstring tendon autograft compared to patellar tendon autograft: a cohort study of 5462 patients with primary anterior cruciate ligament reconstruction

PURPOSE

To compare anterior knee laxity and patient-reported outcome measures (PROMs) between anterior cruciate ligament reconstruction (ACLR) performed with bone-patellar tendon-bone (BPTB) and hamstring tendon (HT) autografts and, moreover, to study any correlation between postoperative anterior knee laxity and PROMs.

METHODS

Patients who underwent primary ACLR at Capio Artro Clinic, Stockholm, Sweden, from January 2000 to October 2015, were identified in our local database. Instrumented laxity measurements and PROMs were reviewed. The KT-1000 arthrometer, with an anterior tibial load of 134-N, was used to evaluate knee laxity preoperatively and at the 6-month follow-up. The Lysholm score was collected preoperatively and at 6 months postoperatively. The Knee injury and Osteoarthritis Outcome Score (KOOS) was collected preoperatively and at the 1-year follow-up.

RESULTS

A total of 5462 primary ACLRs, 692 BPTBs and 4770 HT autografts were included in the study. All the patients showed a significant reduction in knee laxity from preoperatively to postoperatively (BPTB group: from 3.8 ± 2.6 to 1.2 ± 2.1 mm; HT group: from 3.6 ± 3.1 to 1.8 ± 2.2 mm; P < 0.001 for both). The HT group showed a significantly increased postoperative knee laxity compared with the BPTB group (1.8 ± 2.2 vs 1.2 ± 2.1 mm; P < 0.001). The mean anterior tibial translation (ATT) reduction from preoperative to postoperative was significantly larger for the BPTB graft compared with the HT graft (2.7 ± 2.2 vs 1.7 ± 2.6 mm; P < 0.001). A significantly higher rate of "surgical failures", defined as a postoperative side-to-side (STS) difference > 5 mm, was found in the HT group compared with the BPTB group at follow-up (4.3 vs 2.4%; P < 0.001). A significantly larger improvement was found in the HT group compared with the BPTB group for the KOOS Pain (9.5 vs 8.0; P = 0.02), Activities of Daily Living (7.2 vs 5.7; P = 0.006), Sports (24.2 vs 15.3; P < 0.001) and Quality of Life (25.8 vs 22.1; P = 0.001) subscales. No significant difference regarding the mean improvement in the Lysholm knee score was found between the two grafts (BPTB group: 14.5, HT group: 14.0; n.s.). No correlation between postoperative anterior knee laxity and PROMs was found in either graft group.

CONCLUSION

Primary ACLR performed with HT autograft resulted in greater postoperative anterior knee laxity and significantly more surgical failures (STS > 5 mm) compared with BPTB autograft. The BPTB autograft showed a larger anterior knee laxity reduction (ATT reduction) in conjunction with primary ACLR. The HT autograft led to a significantly larger improvement in four of five KOOS subscales from preoperatively to the 1-year follow-up, compared with BPTB autograft. There was no association between postoperative anterior knee laxity and PROMs for either graft. The findings of the present study provide clinicians with valuable information regarding differences in knee laxity and subjective knee function between BPTB and HT autograft after primary ACLR. The use of BPTB autograft should be considered for patients with high knee stability demands.

LEVEL OF EVIDENCE

Retrospective cohort study, Level III.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

III.

The clinical relevance of PCL index on the reconstruction of anterior cruciate ligament with hamstring tendon autograft

The posterior cruciate ligament index (PCL index) has been reported as a diagnostic and prognostic marker for anterior cruciate ligament (ACL) reconstruction. The clinical relevance of PCL index on the reconstruction of ACL with hamstring tendon autograft has not been described in the literature. The objective of this study is to evaluate the importance of the PCL index as a marker of anatomic reconstruction and of functional improvement of patients undergoing ACL reconstruction with HT autograft. Twenty-four patients were submitted to ACL reconstruction with HT autograft. The PCL index was assessed by magnetic resonance imaging before and after surgery. The functional evaluation was performed through the International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form© and Knee Society Knee Scoring System© (IKS). Patients presented a significant positive variation of the PCL index, IKDC and IKS scores. There is no significant correlation between PCL index variation and IKDC and IKS scores (p > 0.05). Unlike other studies reporting a relationship between the PCL index, control of rotational kinematics, and functional improvement in patients undergoing ACL reconstruction with bone-patellar tendon-bone autograft, this study does not demonstrate this association. There is evidence in this study to show that the PCL index may be used as an anatomic reconstructive marker of ACL but not to predict the clinical outcome in this type of reconstruction.

Low re-rupture rate with BPTB autograft and semitendinosus gracilis autograft with preserved insertions in ACL reconstruction surgery in sports persons

PURPOSE

To compare the results of bone-patellar tendon-bone graft (BPTB), semitendinosus-gracilis graft with preserved insertions (STGPI) and semitendinosus-gracilis-free graft (STGF) in terms of graft failure, objective mechanical stability, functional outcome, and return to sports in elite and recreational sports persons. It was hypothesized that the STGPI graft provided superior outcome as compared to the other two grafts.

METHODS

Two hundred and forty-nine elite and recreational players who underwent ACL reconstruction surgery, with BPTB graft (N = 80), STGPI graft (N = 85), and STGF graft (N = 84) with a minimum follow-up of 2 years, were assessed using clinical tests, knee arthrometer (KT 1000™), single-leg hop test, Lysholm knee score, Tegner's activity scale, and return to sports. Groups were matched in terms of age, gender, mode of injury, side involved, the level of sports, associated injuries, and mean follow-up.

RESULTS

The median age of the patients was 24 years (range 16-46 years), with 227 males and 22 females, with a mean follow-up of 61.8 ± 25.9 months. At the final follow-up, the mean side-to-side difference by KT 1000™ was significantly superior in BPTB group (1.4 ± 2.1 mm) as compared to STGPI (1.9 ± 2.0 mm) and STGF group (2.5 ± 2.0 mm) (p = 0.002). The mean Lysholm knee score, Limb symmetry index (LSI) using single-leg hop test and the mean difference in pre-injury and post-surgery level of Tegner's activity scale were not significantly different. The rate of graft failure was significantly higher in STGF group (7.1%) as compared to BPTB (1.2%) and STGPI (1.2%) groups (p = 0.043).

CONCLUSION

BPTB graft is a better graft in terms of mechanical stability than STGPI and STGF grafts. STGPI graft and BPTB graft are superior to STGF graft in terms of graft failure rate. However, there is no statistically significant difference amongst the three grafts in terms of return to sports and clinical tests of instability. STGPI graft is another option in the clinical setting with low graft failure rate like that of BPTB graft and with the added advantage of not having significant donor site morbidity.

LEVEL OF EVIDENCE

III.

Side-to-side asymmetries in landing mechanics from a drop vertical jump test are not related to asymmetries in knee joint laxity following anterior cruciate ligament reconstruction

PURPOSE

Asymmetries in knee joint biomechanics and increased knee joint laxity in patients following anterior cruciate ligament reconstruction (ACLR) are considered risk factors for re-tear or early onset of osteoarthritis. Nevertheless, the relationship between these factors has not been established. The aim of the study was to compare knee mechanics during landing from a bilateral drop vertical jump in patients following ACLR and control participants and to study the relationship between side-to-side asymmetries in landing mechanics and knee joint laxity.

METHODS

Seventeen patients following ACLR were evaluated and compared to 28 healthy controls. Knee sagittal and frontal plane kinematics and kinetics were evaluated using three-dimensional motion capture (200 Hz) and two synchronized force platforms (1000 Hz). Static anterior and internal rotation knee laxities were measured for both groups and legs using dedicated arthrometers. Group and leg differences were investigated using a mixed model analysis of variance. The relationship between side-to-side differences in sagittal knee power/energy absorption and knee joint laxities was evaluated using univariate linear regression.

RESULTS

A significant group-by-leg interaction (p = 0.010) was found for knee sagittal plane energy absorption, with patients having 25% lower values in their involved compared to their non-involved leg (1.22 ± 0.39 vs. 1.62 ± 0.40 J kg^-1). Furthermore, knee sagittal plane energy absorption was 18% lower at their involved leg compared to controls (p = 0.018). Concomitantly, patients demonstrated a 27% higher anterior laxity of the involved knee compared to the non-involved knee, with an average side-to-side difference of 1.2 mm (p < 0.001). Laxity of the involved knee was also 30% higher than that of controls (p < 0.001) (leg-by-group interaction: p = 0.002). No relationship was found between sagittal plane energy absorption and knee laxity.

CONCLUSIONS

Nine months following surgery, ACLR patients were shown to employ a knee unloading strategy of their involved leg during bilateral landing. However, this strategy was unrelated to their increased anterior knee laxity. Side-to-side asymmetries during simple bilateral landing tasks may put ACLR patients at increased risk of second ACL injury or early-onset osteoarthritis development. Detecting and correcting asymmetric landing strategies is highly relevant in the framework of personalized rehabilitation, which calls for complex biomechanical analyses to be applied in clinical routine.

LEVEL OF EVIDENCE

III.

Hamstring Autograft versus Patellar Tendon Autograft for ACL Reconstruction: Is There a Difference in Graft Failure Rate? A Meta-analysis of 47,613 Patients

BACKGROUND

Bone-patellar tendon-bone (bone-tendon-bone) and four-strand hamstring tendon grafts (hamstring) are the most commonly utilized autografts for primary anterior cruciate ligament (ACL) reconstruction. Existing clinical trials, registry studies, and meta-analyses offer conflicting opinions regarding the most favorable graft choice.

QUESTIONS/PURPOSES

Which graft type for ACL reconstruction (bone-tendon-bone or hamstring) has a higher risk of (1) graft rupture and/or (2) graft laxity?

METHODS

We performed a meta-analysis of randomized controlled trials (RCTs), prospective cohort studies, and high-quality national registry studies to compare the outcomes of primary ACL reconstruction with bone-tendon-bone autograft or hamstring autograft. Studies that compared these graft types were identified through a comprehensive search of electronic databases (PubMed, MEDLINE, EMBASE, and the Cochrane Library). Two independent reviewers utilized the Jadad scale for RCT study quality and the Modified Coleman Methodology Score for prospective comparative and registry study quality. The included studies were analyzed for the primary outcome measure of graft rupture with or without revision ACL surgery. In surviving grafts, secondary outcomes of graft laxity were quantified by KT1000/2000™ testing, a positive pivot shift test, and a positive Lachman test. Meta-analysis was performed with Review Manager. A total of 47,613 ACL reconstructions (39,768 bone-tendon-bone and 7845 hamstring) from 14 RCTs, 10 prospective comparative studies, and one high-quality national registry study were included in this meta-analysis. Mean age was 28 years in both groups. Sixty-three percent of patients in the bone-tendon-bone cohort were men versus 57% of patients in the hamstring cohort. Mean followup was 68 ± 55 months.

RESULTS

Two hundred twelve of 7560 (2.80%) bone-tendon-bone grafts ruptured compared with 1123 of 39,510 (2.84%) in the hamstring group (odds ratio = 0.83, 95% confidence interval, 0.72-0.96; p = 0.01). The number needed to treat analysis found that 235 patients would need to be treated with a bone-tendon-bone graft over a hamstring tendon graft to prevent one graft rupture. Instrumented laxity analysis showed that 22% (318 of 1433) of patients in the bone-tendon-bone group had laxity compared with 18% (869 of 4783) in the hamstring tendon group (odds ratio = 0.86; p = 0.16). Pivot shift analysis showed a positive pivot shift in 19% (291 of 1508) of the bone-tendon-bone group compared with 17% (844 of 5062) in the hamstring group (odds ratio = 0.89; p = 0.51). Lachman testing showed a positive Lachman in 25% (71 of 280) of patients receiving bone-tendon-bone grafts compared with 25% (73 of 288) in the hamstring group (odds ratio = 0.96; p = 0.84).

CONCLUSIONS

In this meta-analysis of short- to mid-term followup after primary ACL reconstruction, hamstring autografts failed at a higher rate than bone-tendon-bone autografts. However, failure rates were low in each group, the difference observed was small, and we observed few differences between graft types in terms of laxity. Both graft types remain viable options for primary ACL reconstruction, and the difference in failure rate should be one part of a larger conversation with each individual patient about graft selection that should also include potential differences in donor site morbidity, complication rates, and patient-reported outcome measures. Continued prospective collection of patient data will be important going forward as we attempt to further characterize the potential differences in outcomes attributable to graft selection.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Factors Associated With Improved Function and Maintenance of Sports Activities at 5 to 10 Years After Autologous Hamstring ACL Reconstruction in Young Men

Background:

There are limited data regarding associated factors of return to sports activities at more than 5 years after anterior cruciate ligament (ACL) reconstruction.

Purpose:

To test interrelationships between patient characteristics, concomitant articular lesions, graft laxity, and maintenance of sports activities at 5 to 10 years after ACL reconstruction. It was hypothesized that at 5 to 10 years after the operation in young adult men, maintenance of greater activity level and better knee function would be associated with greater preinjury activity level, younger age at reconstruction, absence of concomitant articular lesions, and minimal graft laxity at follow-up.

Study Design:

Case series; Level of evidence, 4.

Methods:

One hundred six men with autologous hamstring ACL reconstruction between the ages of 18 and 35 years were reviewed at 5 to 10 years after surgery. Excluded patients had contralateral ACL tear, revision reconstruction, or another injury impairing function. Fifty-five patients were eligible and available for follow-up. Independent variables included preinjury Tegner score, time interval from injury to surgery, smoking status, age, articular lesions, KT side-to-side difference, and pivot-shift grade. Main outcome measures were Tegner activity level, International Knee Documentation Committee (IKDC) subjective score, and Knee injury and Osteoarthritis Outcome Scale (KOOS) score at 5 to 10 years after surgery.

Results:

Greater Tegner activity level at follow-up was associated in a regression model with greater preinjury Tegner activity level (correlation coefficient, 0.423; P = .01), lower KT difference (correlation coefficient, –0.278; P = .04), and negative pivot shift (correlation coefficient, –0.277; P = .05). Younger age at operation predicted return to greater Tegner activity level in a univariate analysis (correlation coefficient, –0.266; P = .05) but not in a regression model (not significant). Chondral lesions at surgery predicted lower IKDC subjective scores (71.4 ± 14.3 vs 84.1 ± 11.5; P < .01) and KOOS scores but did not affect maintenance of sports activities.

Conclusion:

At 5 to 10 years after autologous hamstring ACL reconstruction in young men, predictors of greater sports activity level are primarily high preinjury activity level and reestablishment of knee laxity. Younger age at operation and moderate chondral lesions have lower impact in this respect.

Functional recovery following primary ACL repair with dynamic intraligamentary stabilization

BACKGROUND

Recently, a new technique, dynamic intraligamentary stabilization (DIS) was introduced for the acute repair of ACL ruptures. The purpose of this study was to report the functional recovery for patients undergoing acute anterior cruciate ligament (ACL) repair alongside DIS.

METHODS

Forty five patients sustaining acute ACL rupture and treated with DIS repair were retrospectively evaluated. Limb symmetry index of the hop test as well as knee function by means of range of motion, knee swelling, pain and maximum strength were evaluated. Following completion of the rehabilitation program, the difference in anterior-posterior translation (Δ-AP Translation), IKDC, Tegner score (TAS) was additionally analyzed.

RESULTS

Forty five (13 females, 32 males) patients were included in the study. Mean age was 26years (range 18 to 54years). Median time to successfully complete hop test was 22.0weeks (range 11 to 32weeks) postoperatively. Median limb symmetry index 91.6%±8.3%. Median delta anterior-posterior translation compared to the healthy side was plus 0.0mm±1.6mm. Median IKDC was 89.5±6.5. Mean Tegner score (TAS) at 12months of follow-up was seven (range four to nine). Three patients suffered a rerupture during the first 12 postoperative months.

CONCLUSIONS

DIS technique with proper rehabilitation following acute ACL rupture provides successful functional recovery and low rerupture rate at one-year follow-up.