The effect of graft choice on functional outcome in anterior cruciate ligament reconstruction

Increased risk of revision with hamstring tendon grafts compared with patellar tendon grafts after anterior cruciate ligament reconstruction: a study of 12,643 patients from the Norwegian Cruciate Ligament Registry, 2004-2012

BACKGROUND

The graft choice for anterior cruciate ligament reconstruction (ACLR) is controversial. Hamstring tendon (HT) autografts and patellar tendon (PT) autografts are the most common grafts used and have shown similar subjective and objective outcomes.

PURPOSE

To compare the revision rate between HT and PT autografts used in ACLR in Norway and to estimate the influence of patient age and sex.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

The study included all patients who underwent primary ACLR without concomitant ligament injuries registered in the Norwegian Knee Ligament Registry from 2004 through 2012. The cohort was stratified by age group (15-19, 20-29, and ≥30 years) and autograft type (HT or PT). Revision rates at 1, 2, and 5 years were calculated using the Kaplan-Meier analysis, and hazard ratios (HRs) for revision were calculated using multivariate Cox regression models.

RESULTS

With a mean follow-up of 4.0 years, 12,643 primary ACLRs were identified, with 3428 PT and 9215 HT grafts, among which 69 revisions with PT grafts and 362 revisions with HT grafts were performed. The overall 5-year revision rate was 4.2%. A higher revision rate was recorded for HT versus PT grafts at all follow-up times. When adjusted for sex, age, and type of graft, the HR for revision was 2.3 (95% CI, 1.8-3.0) for HT grafts compared with PT grafts. The HR for revision in the youngest age group was 4.0 (95% CI, 3.1-5.2) compared with the oldest age group. Sex had no effect on the revision rate.

CONCLUSION

Patients with HT grafts had twice the risk of revision compared with patients with PT grafts. Younger age was the most important risk factor for revision, and no effect was seen for sex. Further studies should be conducted to identify the cause of the increased revision rate found for HT grafts.

Variables associated with return to sport following anterior cruciate ligament reconstruction: a systematic review

BACKGROUND

As one of the purposes of anterior cruciate ligament reconstruction (ACLR) is to return athletes to their preinjury activity level, it is critical to understand variables influencing return to sport. Associations between return to sport and variables representing knee impairment, function and psychological status have not been well studied in athletes following ACLR.

PURPOSE

The purpose of this review was to summarise the literature reporting on variables proposed to be associated with return to sport following ACLR.

STUDY DESIGN

Systematic review.

METHODS

Medline, EMBASE, CINAHL and Cochrane databases were searched for articles published before November 2012. Articles included in this review met these criteria: (1) included patients with primary ACLR, (2) reported at least one knee impairment, function or psychological measure, (3) reported a return to sport measure and (4) analysed the relationship between the measure and return to sport.

RESULTS

Weak evidence existed in 16 articles suggesting variables associated with return to sport included higher quadriceps strength, less effusion, less pain, greater tibial rotation, higher Marx Activity score, higher athletic confidence, higher preoperative knee self-efficacy, lower kinesiophobia and higher preoperative self-motivation.

CONCLUSIONS

Weak evidence supports an association between knee impairment, functional and psychological variables and return to sport. Current return to sport guidelines should be updated to reflect all variables associated with return to sport. Utilising evidence-based return to sport guidelines following ACLR may ensure that athletes are physically and psychologically capable of sports participation, which may reduce reinjury rates and the need for subsequent surgery.

"Ligamentization" in hamstring tendon grafts after anterior cruciate ligament reconstruction: a systematic review of the literature and a glimpse into the future

PURPOSE

The aims of this study were to provide a systematic review of the literature on "ligamentization" in hamstring tendon (HT) grafts after anterior cruciate ligament (ACL) reconstruction and analyze the postoperative remodeling process in human patients and animal models.

METHODS

We performed a search in the Medline, PubMed, Embase and The Cochrane Library databases, followed by a manual search of reference lists to identify relevant articles. Only studies that investigated the ligamentization of hamstring grafts by histologic examination and comprehensively reported on the remodeling process were deemed eligible for review.

RESULTS

A total of 4 studies were determined appropriate for systematic review: 2 of the included studies investigated human ACL grafts and 2 were performed in animal models. The studies included the examination of 79 human hamstring graft biopsy specimens and grafts of 27 skeletally mature sheep. To verify the remodeling process, authors reported on various aspects of cellularity, vascularity, and collagen organization. None of the included studies reached a level of evidence higher than 3.

CONCLUSIONS

A postoperative ligamentization process can be found in HT grafts after ACL reconstruction and shows a typical progression through 3 distinguishable remodeling phases in humans and in animal models, whereas the progression and intensity of remodeling is distinctly increased in animals.

CLINICAL RELEVANCE

Because postoperative remodeling influences biomechanical properties of hamstring grafts, a better understanding of this process and its timing could lead to substantial improvements in postoperative care strategies and indirectly to the optimization of surgical techniques.

Pivot shift as an outcome measure for ACL reconstruction: a systematic review

PURPOSE

To identify and evaluate the evidence for the pivot shift test as an outcome measure following ACL reconstruction. Achieving rotatory control of the knee post anterior cruciate ligament (ACL) reconstruction has been shown to increase patient satisfaction, decrease functional instability and potentially delay the development of osteoarthritis. The pivot shift is able to assess this rotatory component of knee laxity and appears to have the potential to become a benchmark in gauging the success of ACL surgery. Multiple confounding factors and discrepancies in performing the maneuver itself however put its usefulness in question. Thus, the literature was reviewed to assess whether the pivot shift was able to correlate with final functional outcomes.

METHODS

Two reviewers searched two databases (MEDLINE and EMBASE) for randomized control trials that involved anterior cruciate ligament reconstruction in the last 5 years. All non-clinical studies were excluded. A quality assessment of the included studies was performed using the Jadad scale by a reviewer. The number of studies using the Pivot Shift Test as well as the test's relationship with functional outcome was evaluated.

RESULTS

The literature search yielded 274 studies, of which 65 papers were included. The average Jadad quality score for papers reporting pivot shift as an outcome measure was 2.4, with the most frequent score being 3. Forty seven of 65 studies described the Pivot Shift Test as an outcome measure following ACL reconstruction. Of the 47 studies that included pivot shift as an outcome measure, 40 (85%) correlated with the final functional outcomes.

CONCLUSION

The pivot shift test is an important test following ACL reconstruction, and it correlates with functional outcomes.

Objective criteria for return to athletics after anterior cruciate ligament reconstruction and subsequent reinjury rates: a systematic review

OBJECTIVE

To review anterior cruciate ligament (ACL) clinical studies to assess the objective functional criteria used to determine when patients can return to athletics postoperatively, and to determine the rates of reinjury to either knee when these criteria are applied.

METHODS

A literature search was conducted using the Medline database. The inclusionary criteria were the English language, publication between April 2001 and April 2011, original clinical trials, all levels of evidence, primary ACL reconstruction, skeletal maturity, minimum 2 years of follow-up, and ≥1 objective test used to allow release to sports activities. The exclusionary criteria were revision ACL reconstructions or dislocated knees; studies that specifically excluded patients with ACL graft failure or reinjuries; major concomitant procedures such as high tibial osteotomy, meniscus allograft, other knee ligament reconstructions; and case reports, abstracts, review articles, and technical notes.

RESULTS

Three objective criteria were used to allow release to sports activities. The most common were lower extremity muscle strength, followed by lower limb symmetry, and knee examination parameters of range of knee motion and effusion. Twelve studies listed 1 criterion for release to sports, 8 studies listed 2 criteria, and 1 study recommended 3 criteria. Failure rates of the ACL reconstructions ranged from 0% to 3% in 7 studies, from 4% to 6% in 6 studies, from 7% to 10% in 4 studies, and from 14% to 24% in 4 studies. There were no injuries in the contralateral ACL in 14 studies (67%); in the other 7 studies, contralateral injury was reported in 2% to 15% of patients.

CONCLUSIONS

Few objective functional criteria are used to determine when patients return to unrestricted sports activities. Clinically feasible recommendations are made for measurement of muscle strength, lower limb symmetry, lower limb neuromuscular control, and ligament function in patients who desire to return to athletics after ACL reconstruction. Future studies are required to determine whether the demonstration of normal lower limb function before return to sports is effective in reducing reinjury rates.

The effect of patient and injury factors on long-term outcome after anterior cruciate ligament reconstruction

BACKGROUND

Long-term follow-up is required for accurate assessment of results after anterior cruciate ligament (ACL) reconstruction and recent years have witnessed the publication of numerous papers detailing long-term outcomes. The primary aim of this systematic review was to determine which patient factors affect long-term clinical and radiographic outcomes based on the current literature.

METHODS

A comprehensive literature review yielded 18 prospective manuscripts with minimum follow-up ranging from 5-12 years after ACL reconstruction.

RESULTS

Longer follow-up was associated with increased radiographic evidence of osteoarthritis. Increased meniscal or articular cartilage pathology at ACL reconstruction were found to be associated with increased prevalence of radiographic evidence of osteoarthritis at long-term follow-up in most studies. There is currently insufficient evidence to correlate these intra-articular findings with decreases in clinical outcome measures. Further research is needed to determine the effect of body mass index (BMI) on long-term outcome after ACL reconstruction.

CONCLUSIONS

Intra-articular injuries noted at the time of ACL reconstruction affect long-term results. The effect of BMI and other patient factors is unclear. Long-term follow-up of large multicenter cohorts will provide definitive data on the relative importance of different factors in determining results of ACL reconstruction.

Graft selection in arthroscopic anterior cruciate ligament reconstruction

Background

Anterior cruciate ligament (ACL) surgical reconstruction is performed with the use of an autogenic, allogenic or synthetic graft. The document issued by the Italian National Guidelines System (SNLG, Sistema Nazionale Linee Guida) at the National Institute of Health aims to guide orthopaedic surgeons in selecting the optimal graft for ACL reconstruction using an evidence-based approach.

Materials and methods

A monodisciplinary panel was formed to define a restricted number of clinical questions, develop specific search strategies and critically appraise the literature using the grading of recommendations assessment, development, and evaluation (GRADE) method. The final draft was shared by the panel and then sent to four external referees to assess its readability and clarity, its clinical relevance and the feasibility of recommendations.

Results

Autograft shows moderate superiority compared with allograft, in relation to the relevant outcomes and the quality of selected evidence, after an appropriate risk–benefit assessment. Allograft shows higher failure rate and higher risk of infection. The panel recommends use of autografts; patellar tendon should be the first choice, due to its higher stability, while use of hamstring is indicated for subjects for whom knee pain can represent a particular problem (e.g., some categories of workers).

Conclusions

Autograft shows better performance compared with allograft and no significant heterogeneity in relation to relevant outcomes. The GRADE method allowed collation of all the information needed to draw up the recommendations, and to highlight the core points for discussion.

IKDC or KOOS: which one captures symptoms and disabilities most important to patients who have undergone initial anterior cruciate ligament reconstruction?

BACKGROUND

Knee-specific patient-reported outcome measures are frequently used after anterior cruciate ligament reconstruction but little is known about whether they measure outcomes important to patients.

PURPOSE

The aim of this study was to identify which instrument, the Knee injury and Osteoarthritis Outcome Score (KOOS) or the International Knee Documentation Committee Subjective Knee Form (IKDC), captures symptoms and disabilities most important to patients who have undergone initial anterior cruciate ligament reconstruction.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Data were collected from 126 participants of an Internet knee forum. A self-reported online questionnaire was developed consisting of demographic and surgical data, the Tegner Activity Scale, and 49 consolidated items from the KOOS and the IKDC. Item importance, frequency, and frequency-importance product were calculated.

RESULTS

Seventy-eight percent of the items from the IKDC were experienced by more than half of the patients, compared with 57% from the KOOS. Items extracted from the Function in Sports/Recreation and Quality of Life KOOS subscales were highly important to this group of patients. For patients 12 months or more after anterior cruciate ligament reconstruction, 94% of the IKDC items had a frequency-importance product of 1 or less compared with 86% of the KOOS items.

CONCLUSION

Overall, the IKDC items outperformed the KOOS items on all of the 5 criteria with the exception of the frequency-importance product for patients who were 12 months after anterior cruciate ligament reconstruction. The KOOS Function in Sports/Recreation and Knee-Related Quality of Life subscales outperformed the IKDC for the total cohort as well as for male and female subgroups. However, differences in individual items were not always evident from either total scale or subscale ratings. Studies should use patient-reported outcomes that reflect patients' most important concerns and further prospective longitudinal research is required in this area.

Treatment of anterior cruciate ligament injuries with special reference to graft type and surgical technique: an assessment of randomized controlled trials

PURPOSE

The primary aim was to summarize and assess current evidence from randomized controlled trials (RCTs) on anterior cruciate ligament injuries, with special reference to graft type and surgical technique. The secondary aims were to identify the relative strengths and weaknesses of the selected studies, to resolve contradictions in the literature, and to evaluate the need for further studies.

METHODS

A PubMed database search using the key words "anterior cruciate ligament" was performed. The search was limited to RCTs published in English between January 1995 and March 2009. Articles on the subject of graft type and surgical technique were identified. After initial screening and a subsequent quality appraisal based on the CONSORT (Consolidated Standards of Reporting Trials) Statement, a total of 39 articles were included in this review.

RESULTS

There are no differences between the bone-patellar tendon-bone (BPTB) graft and the hamstring tendon (HT) graft in terms of laxity, clinical outcome, time to return to sports, patellofemoral crepitations, 1-leg hop test, range of motion, thigh muscle circumference, or anterior knee sensory deficit. The BPTB graft produces more anterior knee pain and kneeling pain than the HT graft, but the difference disappears with time. The harvest site affects muscle strength initially but not over time. There is a possible correlation between the development of osteoarthritis and the BPTB graft. The HT graft produces more tunnel widening than the BPTB graft, but there is no correlation between tunnel widening and clinical outcome or laxity. The semitendinosus and gracilis graft is associated with inferior knee flexion at higher angles, as compared with the semitendinosus graft. There are probably no differences between the BPTB graft and the bone-HT-bone graft in terms of laxity and clinical outcome. Semitendinosus and gracilis tendon harvesting probably reduces hamstring muscle strength for approximately 1 year. Double-bundle reconstruction produces less rotatory laxity than single-bundle reconstruction. Double-bundle reconstruction by use of an 8-strand HT graft probably produces less laxity than single-bundle reconstruction. There are no differences in clinical outcome when single-bundle and double-bundle anterior cruciate ligament reconstructions are compared.

CONCLUSIONS

In the quality assessment several weaknesses in the study design of the RCTs were found. This emphasizes the need for further high-quality studies, especially with long-term follow-up.

LEVEL OF EVIDENCE

Level II, systematic review of randomized controlled trials.