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

Sports participation 2 years after anterior cruciate ligament reconstruction in athletes who had not returned to sport at 1 year: a prospective follow-up of physical function and psychological factors in 122 athletes

BACKGROUND

A return to their preinjury level of sport is frequently expected within 1 year after anterior cruciate ligament (ACL) reconstruction, yet up to two-thirds of athletes may not have achieved this milestone. The subsequent sports participation outcomes of athletes who have not returned to their preinjury level sport by 1 year after surgery have not previously been investigated.

PURPOSE

To investigate return-to-sport rates at 2 years after surgery in athletes who had not returned to their preinjury level sport at 1 year after ACL reconstruction.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A consecutive cohort of competitive- and recreational-level athletes was recruited prospectively before undergoing ACL reconstruction at a private orthopaedic clinic. Participants were followed up at 1 and 2 years after surgery with a sports activity questionnaire that collected information regarding returning to sport, sports participation, and psychological responses. An independent physical therapist evaluated physical function at 1 year using hop tests and the International Knee Documentation Committee knee examination form and subjective knee evaluation.

RESULTS

A group of 122 competitive- and recreational-level athletes who had not returned to their preinjury level sport at 1 year after ACL reconstruction participated. Ninety-one percent of the athletes returned to some form of sport after surgery. At 2 years after surgery, 66% were playing sport, with 41% playing their preinjury level of sport and 25% playing a lower level of sport. Having a previous ACL reconstruction to either knee, poorer hop-test symmetry and subjective knee function, and more negative psychological responses were associated with not playing the preinjury level sport at 2 years.

CONCLUSION

Most athletes who were not playing sport at 1 year had returned to some form of sport within 2 years after ACL reconstruction, which may suggest that athletes can take longer than the clinically expected time of 1 year to return to sport. However, only 2 of every 5 athletes were playing their preinjury level of sport at 2 years after surgery. When the results of the current study were combined with the results of athletes who had returned to sport at 1 year, the overall rate of return to the preinjury level sport at 2 years was 60%. Demographics, physical function, and psychological factors were related to playing the preinjury level sport at 2 years after surgery, supporting the notion that returning to sport after surgery is multifactorial.

Controversies in knee rehabilitation: anterior cruciate ligament injury

Controversy in management of athletes exists after anterior cruciate ligament (ACL) injury and reconstruction. Consensus criteria for evaluating successful outcomes following ACL injury include no reinjury or recurrent giving way, no joint effusion, quadriceps strength symmetry, restored activity level and function, and returning to preinjury sports. Using these criteria, the success rates of current management strategies after ACL injury are reviewed and recommendations are provided for the counseling of athletes after ACL injury.

Addition of autologous mesenchymal stem cells to whole blood for bioenhanced ACL repair has no benefit in the porcine model

BACKGROUND

Coculture of mesenchymal stem cells (MSCs) from the retropatellar fat pad and peripheral blood has been shown to stimulate anterior cruciate ligament (ACL) fibroblast proliferation and collagen production in vitro. Current techniques of bioenhanced ACL repair in animal studies involve adding a biologic scaffold, in this case an extracellular matrix-based scaffold saturated with autologous whole blood, to a simple suture repair of the ligament. Whether the enrichment of whole blood with MSCs would further improve the in vivo results of bioenhanced ACL repair was investigated.

HYPOTHESIS

The addition of MSCs derived from adipose tissue or peripheral blood to the blood-extracellular matrix composite, which is used in bioenhanced ACL repair to stimulate healing, would improve the biomechanical properties of a bioenhanced ACL repair after 15 weeks of healing.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twenty-four adolescent Yucatan mini-pigs underwent ACL transection followed by (1) bioenhanced ACL repair, (2) bioenhanced ACL repair with the addition of autologous adipose-derived MSCs, and (3) bioenhanced ACL repair with the addition of autologous peripheral blood derived MSCs. After 15 weeks of healing, the structural properties of the ACL (yield load, failure load, and linear stiffness) were measured. Cell and vascular density were measured in the repaired ACL via histology, and its tissue structure was qualitatively evaluated using the advanced Ligament Maturity Index.

RESULTS

After 15 weeks of healing, there were no significant improvements in the biomechanical or histological properties with the addition of adipose-derived MSCs. The only significant change with the addition of peripheral blood MSCs was an increase in knee anteroposterior laxity when measured at 30° of flexion.

CONCLUSION

These findings suggest that the addition of adipose or peripheral blood MSCs to whole blood before saturation of an extracellular matrix carrier with the blood did not improve the functional results of bioenhanced ACL repair after 15 weeks of healing in the pig model.

CLINICAL RELEVANCE

Whole blood represents a practical biologic additive to ligament repair, and any other additive (including stem cells) should be demonstrated to be superior to this baseline before clinical use is considered.

Predictors of contralateral anterior cruciate ligament reconstruction: a cohort study of 9061 patients with 5-year follow-up

BACKGROUND

Identifying predictors of contralateral anterior cruciate ligament (ACL) reconstruction is important to focus preventive strategies and related research on high-risk groups.

PURPOSE

To investigate predictors of contralateral ACL reconstruction in patients who have already undergone a primary ipsilateral reconstruction.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

This study was based on data from the Swedish National Knee Ligament Register from January 1, 2005, to December 31, 2013. Patients aged 13 to 59 years who underwent primary ipsilateral (index) ACL reconstruction with hamstring tendon or bone-patellar tendon-bone autografts were included. Follow-up started on date of index ACL reconstruction and ended either with primary contralateral ACL reconstruction, after 5 years of follow-up, or on December 31, 2013, whichever occurred first. The investigated variables were patient sex, age at index reconstruction, activity at the time of index injury, timing of surgery, graft selection, graft harvest site, and meniscal and chondral injury. The study end point was primary contralateral ACL reconstruction. Relative risks (RRs) and 95% CIs were calculated and adjusted for confounding factors using multivariate statistics.

RESULTS

A total of 9061 participants were included (n = 5196 males [57.3%] and 3865 females [42.7%]), of which 270 participants (3.0%) underwent primary contralateral ACL reconstruction during the 5-year follow-up. There was no difference in contralateral reconstruction rates between males and females (3.0% vs 2.9%, P = .695). Age <20 years significantly increased the risk of contralateral reconstruction (males: RR = 2.4 [95% CI, 1.7-3.4] and females: RR = 2.9 [95% CI, 1.9-4.5]; P < .001). Among female patients undergoing reconstruction using autograft hamstring, harvest of a contralateral hamstring tendon significantly increased this risk (RR = 3.4 [95% CI, 1.4-7.9]; P = .006).

CONCLUSION

In both male and female participants, age <20 years predicted an almost 3 times higher 5-year risk of contralateral ACL reconstruction. Among female participants undergoing reconstruction with autograft hamstring, a contralateral harvest predicted a more than 3 times higher 5-year risk of contralateral ACL reconstruction. Patient sex, activity at the time of index injury, graft selection, meniscal injury, and chondral injury were not predictors of contralateral ACL reconstruction.

Bridge-enhanced ACL repair: A review of the science and the pathway through FDA investigational device approval

Injuries to the anterior cruciate ligament (ACL) are currently treated with replacement of the torn ligament with a graft of tendon harvested from elsewhere in the knee. This procedure, called "ACL reconstruction," is excellent for restoring gross stability to the knee; however, there are relatively high graft failure rates in adolescent patients (Barber et al. in Arthroscopy 30(4):483-491, (2014); Engelman et al. in Am J Sports Med, (2014); Webster et al. in Am J Sports Med 42(3):641-647, (2014)), and the ACL reconstruction procedure does not prevent the premature osteoarthritis seen in patients after an ACL injury (Ajuied et al. in Am J Sports Med, (2013); Song et al. in J Sports Med 41(10):2340-2346, (2013); Tourville et al. Am J Sports Med 41(4):769-778, (2013)) .Thus, new solutions are needed for ACL injuries. Researchers have been investigating the use of scaffolds, growth factors and cells to supplement a suture repair of the ACL (bridge-enhanced repair; also called bio-enhanced repair in prior publications). In this paper, we will review the varied approaches which have been investigated for stimulating ACL healing and repair in preclinical models and how one of these technologies was able to move from promising preclinical results to FDA acceptance of an investigational device exemption application for a first-in-human study.

Nonanatomic anterior cruciate ligament reconstruction with double-stranded semitendinosus grafts in children with open physes: minimum 15-year follow-up

BACKGROUND

Nonanatomic anterior cruciate ligament (ACL) reconstruction (ACLR) with double-stranded semitendinosus grafts in children with open physes has been described as a successful surgical technique in short-term follow-up clinical reports.

PURPOSE

To evaluate the clinical outcomes of nonanatomic ACLR in children with open physes and a minimum of 15 years' follow-up.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Twelve patients with an average age of 10.7 years (range, 8.3-12.4 years) underwent ACLR between 1991 and 1998. All patients were classified as Tanner development stage 2 or lower. The surgical technique involved transphyseal tibial tunnel drilling and over-the-top (OTT) femoral fixation using a double-stranded graft for all patients. Clinical outcomes were evaluated in terms of the manual Lachman test, pivot-shift test, return to sports activity, and International Knee Documentation Committee (IKDC) score at the end of growth and at a minimum 15-year follow-up (range, 15-22 years).

RESULTS

No clinically significant growth disturbance was observed. Ten patients had a grade A IKDC score, and 2 patients had a grade B IKDC score at the end of growth. There was no progression of laxity or modification of knee stability with growth. Three patients (25%) had ACL reruptures during sports activities after growth plate closure. All patients with reruptured ACLs underwent additional reconstructive surgery.

CONCLUSION

Anterior cruciate ligament reconstruction using the OTT technique in the femur and the transphyseal technique in the tibia produces good results with regard to growth plate closure but a high failure rate in adulthood.

The epidemiology of revision anterior cruciate ligament reconstruction in Ontario, Canada

BACKGROUND

Knowledge of the rate of and risk factors for re-revision, reoperation, and readmission after revision anterior cruciate ligament reconstruction (ACLR) is limited.

PURPOSE

To determine the rate of and risk factors for re-revision, reoperation, and readmission after revision ACLR.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

All patients who underwent first revision ACLR in Ontario, Canada, from January 2004 to December 2010 were identified and followed until December 2012. Exclusions included age <16 years, previous osteotomy, or multiligament knee reconstruction. The main outcome was re-revision ACLR. Secondary outcomes included reoperation (irrigation and debridement [I&D], meniscectomy, manipulation under anesthesia, contralateral ACLR, and total knee arthroplasty) and readmission. Survival to re-revision was determined using the Kaplan-Meier approach. A Cox proportional hazards model or logistic regression were used to determine the influence of patient, surgical, and provider factors on outcomes. A post hoc analysis was performed to determine the influence of the aforementioned factors on postoperative infection risk.

RESULTS

Overall, 827 patients were included (median age, 30 years; 58.8% males). Single-stage revisions comprised 92.9% of cases, and a meniscal procedure (repair or debridement) was performed in 45.3% of cases. The re-revision rate at a mean follow-up of 4.8 ± 2.2 years was 4.4%, and the 5-year survival rate was 95.4%. The rates of I&D, meniscectomy, contralateral ACLR, and readmission were 0.8%, 3.1%, 3.4%, and 4.1%, respectively. Manipulation under anesthesia and total knee arthroplasty were rare. Young age significantly increased contralateral ACLR risk (risk decreased by 5.1% with each year of age >16 years; P = .02) but not re-revision ACLR risk. Low surgeon's annual volume of revision ACLR (<4 revisions/year: odds ratio, 1.2; P = .02) and male sex (odds ratio, 13.3; P = .01) significantly increased overall infection risk; male sex also influenced I&D risk.

CONCLUSION

Re-revision, reoperation, and readmission rates after revision ACLR were low, and the risk for I&D, infection, and contralateral ACLR were influenced by male sex, low surgeon volume, and young age, respectively.

CLINICAL RELEVANCE

This is the first study to determine morbidity rates and risk factors after revision ACLR, providing reference data from the general population.

Correlation Analysis of Potential Factors Influencing Graft Maturity After Anterior Cruciate Ligament Reconstruction

Background:

Postoperatively, signal changes of the reconstructed anterior cruciate ligament (ACL) graft on magnetic resonance imaging (MRI) images commonly occurs, which may be a cause for concern. The signal intensity changes are usually expressed by signal/noise quotient (SNQ) value, representing graft maturity. To date, little is known about the factors influencing the SNQ value of the reconstructed ACL graft.

Purpose:

To evaluate ACL graft SNQ value and associated factors after ACL reconstruction.

Study Design:

Case series; Level of evidence, 4.

Methods:

Male patients who underwent ACL reconstruction using autograft or allograft tendon from September 2004 to September 2011 were randomly invited to take part in this investigation, including functional scores, physical examination, and MRI scan. The femoral side graft was fixed with Endobutton CL or Rigidfix pins, and the tibial side graft was fixed with a bio-intrafix. SNQ values of each graft were measured on MRI to represent graft maturity. Sagittal ACL angle, ACL–Blumensaat line angle, and medial and lateral posterior tibial slope (PTS) were measured using MRI 3-dimensional dual-echo steady-state images. Potential risk factors, including age, body mass index, postoperative time, Tegner activity scale (TAS), sagittal ACL angle, ACL–Blumensaat line angle, medial PTS, lateral PTS, and primary graft diameter, were tested for their association with the graft SNQ value by multivariate stepwise regression analysis.

Results:

A total of 104 male subjects (mean follow-up, 30.7 months) were examined, including 62 allograft and 42 autograft reconstructions. There was a significant association between graft SNQ and postoperative time (r = −0.431, P < .001), TAS (r = 0.295, P = .002), and ACL–Blumensaat line angle (r = −0.304, P = .002). Univariate regression analysis showed that TAS (β = 6.15, P < .001) positively correlated, postoperative time (β = −0.26, P < .001) negatively correlated, and ACL–Blumensaat line angle (β = −0.40, P = .038) negatively correlated with graft SNQ. Multivariate stepwise regression analysis showed that TAS, postoperative time, ACL–Blumensaat line angle, and age were significant independent factors associated with graft SNQ.

Conclusion:

The graft SNQ value had a significant positive correlation with physical activity level and a significant negative correlation with postoperative time in this study. Males with a shorter postoperative time and a higher physical activity level had higher graft signal intensity postoperatively.

Fifty-five per cent return to competitive sport following anterior cruciate ligament reconstruction surgery: an updated systematic review and meta-analysis including aspects of physical functioning and contextual factors

BACKGROUND

The aim of this study was to update our original systematic review of return to sport rates following anterior cruciate ligament (ACL) reconstruction surgery.

METHOD

Electronic databases were searched from April 2010 to November 2013 for articles reporting the number of patients returning to sport following ACL reconstruction surgery. Return to sport rates, physical functioning and contextual data were extracted and combined using random-effects meta-analyses. Data from the original review (articles published up to April 2010) were combined with data from the updated search.

RESULTS

Sixty-nine articles, reporting on 7556 participants, were reviewed. On average, 81% of people returned to any sport, 65% returned to their preinjury level of sport and 55% returned to competitive level sport after surgery. Symmetrical hopping performance (d=0.3) and the contextual factors of younger age (d=-0.3), male gender (OR=1.4), playing elite sport (OR=2.5) and having a positive psychological response (d=0.3) favoured returning to the preinjury level sport. Receiving a hamstring tendon autograft favoured returning to competitive level sport (OR=2.4), whereas receiving a patellar tendon autograft favoured returning to the preinjury level sport (OR=1.2).

CONCLUSIONS

Returning to sport varied according to different physical functioning and contextual factors, which could warrant additional emphasis in postoperative rehabilitation programmes to maximise participation.