Comparison of Graft Failure Rate Between Autografts Placed via an Anatomic Anterior Cruciate Ligament Reconstruction Technique: A Systematic Review, Meta-analysis, and Meta-regression

Mesenchymal Stem Cell Exosome and Fibrin Sealant Composite Enhances Rabbit Anterior Cruciate Ligament Repair

BACKGROUND

The anterior cruciate ligament (ACL) fails to heal after rupture, leading to joint instability and an increased risk of osteoarthritis. Mesenchymal stem/stromal cell (MSC) exosomes have reported wide-ranging therapeutic efficacy; however, their potential for augmenting ACL repair remains to be investigated.

PURPOSE

To evaluate the use of MSC exosomes with fibrin sealant on biological augmentation of ACL healing after suture repair and their effects on ACL fibroblast functions.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twelve rabbit knees underwent ACL transection and suture repair. MSC exosome and fibrin composite (Exosome+Fibrin) or fibrin (Fibrin) alone was used to supplement the suture repair in 6 knees. ACL repair was assessed by magnetic resonance imaging at 6 and 12 weeks postoperatively and by histologic and immunohistochemical analyses at 12 weeks. To investigate the mechanisms through which MSC exosomes augment ACL repair, metabolic activity, proliferation, migration, and matrix synthesis assays were performed using the primary ACL fibroblasts. RNA sequencing was also performed to assess global gene expression changes in exosome-treated ACL fibroblasts.

RESULTS

Based on magnetic resonance imaging findings, 5 of 6 Exosome+Fibrin-treated ACLs were completely or partially healed, as opposed to 5 of 6 Fibrin-treated ACLs appearing torn at 6 and 12 weeks postoperatively. Additionally, 4 of 6 Exosome+Fibrin-treated ACLs were isointense, as compared with 5 of 6 Fibrin-treated ACLs that were hyperintense, indicating improved remodeling and maturation of the repaired ACLs with Exosome+Fibrin treatment. Histologically, Exosome+Fibrin-treated ACLs showed more organized collagen fibers and abundant collagen deposition, with a high amount of collagen I and relatively lower amount of collagen III, which are consistent with the matrix structure and composition of the normal ACL. Cell culture studies using ACL fibroblasts showed that MSC exosomes enhanced proliferation, migration, and collagen synthesis and deposition, which are cellular processes relevant to ACL repair. Further gene set enrichment analysis revealed key pathways mediated by MSC exosomes in enhancing proliferation and migration while reducing matrix degradation of ACL fibroblasts.

CONCLUSION

The combination of MSC exosomes and fibrin sealant (Exosome+Fibrin) applied to a suture repair enhanced the morphologic and histologic properties of the ACL in a rabbit model, and these improvements could be attributed to the augmented functions of ACL fibroblasts with exosome treatment.

CLINICAL RELEVANCE

This work supports the use of MSC exosomes in biological augmentation of ACL healing after suture repair.

Chronic reactive synovitis in patients undergoing ACL reconstruction and augmentation with tape-type sutures

Introduction

Arthroscopic Anterior Cruciate Ligament Reconstruction (ACLR) with internal bracing and augmentation using tape-type sutures (TTS) has gained popularity due to its biomechanical advantages. However, concerns have emerged regarding chronic reactive synovitis, which can lead to graft failure and the need for revision surgery. The purpose of this research is to determine the prevalence of chronic reactive synovitis after TTS-reinforced ACLR.

Materials and methods

A retrospective review was conducted on a series of 84 patients who underwent arthroscopic ACL reconstruction with FiberTape or SutureTape augmentation, performed by a single surgeon in the year 2019.

Results

Of the 84 patients analyzed, 17 presented with at least two or more symptoms, including persistent instability, knee pain, swelling, stiffness, and local rise in temperature, within 3-45 months post-surgery. All required secondary surgery, either for synovectomy, and tape removal (8 cases) or revision ACLR (9 cases). Intraoperative histopathological analysis confirmed the diagnosis of reactive synovitis due to foreign body reaction. One year after the secondary surgery, all 17 knees showed satisfactory results. None of the patients experienced the pain, swelling, or instability that they had before the secondary surgery.

Conclusion

Foreign body synovitis was found in 17 symptomatic patients out of 84 (20.2 %) who underwent ACLR with TTS reinforcement one year. While this study does not establish a direct causal link between tape-type sutures and the development of synovitis, it emphasizes the significance of remaining vigilant for impending reactive synovitis as a complication, given the potential exposure of the knee to foreign body material.

Level of evidence

Level IV (Retrospective case series without a comparison group).

Over-The-Top Technique for ACL Reconstruction: Advantages, Disadvantages, and Postoperative Complications

Anterior cruciate ligament (ACL) injuries are the most common knee joint injuries related to sports activities in clinical practice. For treating ACL injuries, anatomical reconstruction surgery is often the preferred method. The over-the-top (OTT) technique is a surgical approach that eliminates the need for creating a femoral tunnel. According to the existing literature, the OTT technique offers distinct advantages, particularly for skeletally immature individuals and in revision cases. Currently, femoral tunnel failure is the most common cause of ACL reconstruction failure, which can lead to less than optimal postoperative performance of the ACL and a higher likelihood of needing a revision. Additionally, mistakes in the placement of the femoral tunnel and the subsequent risk of tunnel enlargement can increase the complexity of revision procedures, ultimately reducing the long-term clinical effectiveness for patients. In contrast, the OTT technique has shown excellent biomechanical performance, avoids the need for bone tunnels, is economically practical, and has been proven to provide satisfactory therapeutic outcomes both in the short and long term, especially for skeletally immature individuals and in revision cases. The OTT technique is deemed a safe and effective surgical method for treating ACL injuries. In summary, the OTT technique has unique benefits for skeletally immature individuals and in revision cases, making it a viable option worth considering. Level of evidence V.

Editorial Commentary: Quadrupled Semitendinosus Autograft Is a Suitable Graft Choice for Anterior Cruciate Reconstruction, Regardless of Diameter, in Patients With Lower Risk for Rerupture

Multiple options exist for anterior cruciate ligament reconstruction autografts, including bone-patellar tendon-bone, quadriceps tendon, and hamstring tendon (HT). A variant among HT options is quadrupled semitendinosus autograft. In addition, smaller graft diameter (<8 mm) has been associated with failure of HT anterior cruciate ligament reconstruction. However, recent research shows that quadrupled semitendinosus autograft diameters <8 mm are not correlated with a higher rerupture rate in older patients. While among individuals with a lower risk of rerupture, graft diameter does not significantly alter graft rupture rates, and a smaller-diameter soft tissue graft is safe to use in the low-risk population, caution is required when applying this dogma to patients who are younger than 21 years or play higher-risk sports. In such patients, a reliable option is bone-patellar tendon-bone autograft and/or adding a secondary stabilizing procedure such as anterolateral ligament reconstruction or lateral extra-articular tenodesis. Finally, recent research shows there is little utility in trying to predict graft size prior to surgery.

Return to Sport and Graft Failure Rates After Primary Anterior Cruciate Ligament Reconstruction With a Bone-Patellar Tendon-Bone Versus Hamstring Tendon Autograft: A Systematic Review and Meta-analysis

BACKGROUND

Anterior cruciate ligament (ACL) tears are frequent injuries in athletes that often require surgical reconstruction so that patients may return to their previous levels of performance. While existing data on patient-reported outcomes are similar between bone-patellar tendon-bone (BTB) and hamstring tendon (HT) autografts, the literature regarding return to sport (RTS), return to previous levels of sport activity, and graft failure rate remains limited.

PURPOSE

To compare rates of RTS, return to previous activity levels, and graft retears among athletes undergoing primary ACL reconstruction using a BTB versus HT autograft.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

The MEDLINE, Embase, and Cochrane Library databases were queried, and studies reporting on RTS after primary ACL reconstruction using a BTB or HT autograft were included. Exclusion criteria included revision reconstruction, ACL repair, quadriceps tendon autografts, allografts, graft augmentation, or double-bundle autografts. Rates of RTS, return to previous levels of activity, and retears were extracted and analyzed across included studies.

RESULTS

A total of 33 articles met inclusion criteria, with a patient cohort of 4810 athletes. The overall RTS rate for all athletes was 80.4% (95% CI, 75.3%-84.6%) at a mean follow-up of 35.7 months, with 54.6% (95% CI, 48.5%-60.6%) returning to preinjury levels of activity. No significant difference was found between BTB and HT autografts with respect to rates of RTS, return to preinjury activity levels, or reruptures. The overall RTS rate in patients after primary ACL reconstruction with a BTB autograft was 83.3% (95% CI, 77.0%-88.2%), with 56.1% (95% CI, 49.3%-62.7%) returning to preinjury levels of activity. Conversely, the overall RTS rate in patients after primary ACL reconstruction with an HT autograft was 77.9% (95% CI, 70.3%-84.0%), with 53.5% (95% CI, 42.8%-63.9%) returning to preinjury levels of activity. The overall graft rerupture rate for the entire patient cohort was 3.6% (95% CI, 2.5%-5.1%), for patients with BTB grafts was 3.2% (95% CI, 1.9%-5.3%), and for patients with HT grafts was 4.4% (95% CI, 2.8%-6.8%).

CONCLUSION

Primary ACL reconstruction using BTB autografts demonstrated similar rates of RTS, return to previous activity levels, and reruptures compared with reconstruction using HT autografts.

Effect of Graft Choice for ACL Reconstruction on Clinical Outcomes in Combined ACL and MCL Injuries: Comparison Between Bone-Patellar Tendon-Bone and Hamstring Autografts

Background/Objectives: The optimal graft, particularly in combined anterior cruciate ligament (ACL) and medial collateral ligament (MCL) injuries, remains controversial. We evaluated the influence of graft choice between bone-patellar tendon-bone (BPTB) and hamstring autografts on clinical outcomes in combined ACL and MCL injuries. Methods: This retrospective analysis included patients with concurrent ACL and MCL injuries who underwent single-bundle ACL reconstruction with BPTB (group B) or hamstring (group H) grafts, between 2010 and 2019, with a ≥2-year follow-up. Patients were classified based on the MCL injury grade (I, II, or III). Clinical outcomes were assessed through knee stability evaluations using valgus stress radiographs and the KT-2000 arthrometer, patient-reported outcomes using the International Knee Documentation Committee (IKDC) subjective score and Lysholm score, and radiologic outcomes using the IKDC radiographic grade. Results: The study included 169 patients (group B, 92; group H, 77). No significant between-group differences in knee stability or functional outcomes were found after follow-up. Within the same MCL injury grade, particularly in high-grade MCL injuries, BPTB grafts resulted in significantly better medial stability (side-to-side difference in medial joint opening on valgus stress radiographs: grade II, p = 0.006; grade III, p = 0.039) and functional outcomes (IKDC subjective score: grade II, p = 0.045; grade III, p = 0.038) than hamstring grafts. In the hamstring group, higher-grade MCL injuries were associated with worse outcomes (Lysholm knee score, p = 0.009; IKDC subjective score, p = 0.015). Conclusions: Graft choice in ACL reconstruction with concomitant MCL injuries may affect clinical outcomes, particularly in high-grade MCL injuries. Although both graft types performed similarly overall, BPTB grafts provided superior medial stability and functional results in higher-grade MCL injuries. However, caution is needed when interpreting these results due to limitations such as the small sample size and the lack of randomization in graft selection.

Trends in Anterior Cruciate Ligament Reconstruction Techniques and Postoperative Care Among Leaders in the Field: A Survey of the Herodicus Society

Background

Despite a growing body of literature regarding anterior cruciate ligament reconstruction (ACLR), there remains a wide diversity in surgical technique and clinical practice across providers.

Purpose

To (1) describe current ACLR practice preferences among members of the Herodicus society and (2) determine whether these preferences are influenced by years in practice and overall surgical volume.

Study Design

Cross-sectional study.

Methods

A 24-question survey investigating surgeons' practices and preferred ACLR surgical techniques was sent via email to all active Herodicus Society members. Survey responses were subdivided by years of experience and overall ACLR annual case volume. Descriptive statistics were compiled and chi-square testing was utilized to determine the significance of experience and case volume on survey responses.

Results

Of the 113 invited Herodicus Society members who perform ACLR, 69 (61%) completed the survey. Respondents had a mean ± SD of 30.9 ± 9.8 years of experience in clinical practice and performed a mean of 96.0 ± 50.7 primary and 21.6 ± 16.9 revision ACLR annually. Of revision cases, 72.1% were performed using a single-stage technique. Mean frequency of graft usage by surgeon was bone-patellar tendon-bone autograft (58.6%), quadriceps autograft (14.6%), hamstring tendon autograft (14.0%), and allograft (11.8%). The plurality of surgeons responded that they used anterolateral augmentation "rarely" in primary ACLR (39.1%) and "sometimes" in revision ACLR (31.9%), with the majority performing lateral extra-articular tenodesis (66.7%) rather than anterolateral ligament reconstruction (14.5%). Most surgeons would not allow a 20-year-old football player to return before 7 months after ACLR (71.0%) but highly valued return-to-sports testing to determine readiness (94.2%). Higher volume surgeons performed single-stage revision ACLR at a significantly higher rate (79.8% vs 62.9%, P = .02) and significantly differed in return-to-sports criteria, with a greater proportion relying primarily on biometric testing (P = .01).

Conclusion

The survey demonstrated that, in the Herodicus Society, a wide range of preferences exist regarding ACLR surgical technique. Bone-patellar tendon-bone autograft is the most frequent primary ACLR graft choice. Most participants have not embraced newer techniques such as anterolateral or suture tape augmentation. Return to sports is generally not allowed before 7 months and heavily factors-in return-to-sports testing metrics, suggesting that purely time-based criteria for return to sports is not modern practice among elite sports medicine surgeons.

Practice Patterns and Return-to-Sports Timing of National Football League Head Team Physicians for ACL Reconstruction

Background

Previous surveys of the practice patterns for anterior cruciate ligament (ACL) reconstruction in collegiate and professional team physicians have shown bone-patellar tendon-bone (BPTB) autograft being the most common graft, with variable return-to-sports timing.

Purpose

To evaluate the current practice patterns and return-to-sports timing of National Football League (NFL) head team physicians for ACL reconstruction.

Study Design

Cross-sectional study.

Method

All 32 NFL head team orthopaedic surgeons were surveyed and asked their primary ACL graft preference, revision ACL graft preference, use of lateral extra-articular tenodesis (LET) or anterolateral ligament reconstruction (ALL), use of suture brace augmentation, return-to-sport timing, and whether functional testing was utilized in determining readiness of return to play. The years of experience of the physician were also evaluated.

Results

All 32 head team physicians responded, with 31 (97%) using ipsilateral BPTB autograft in the primary setting and 1 using ipsilateral quadriceps autograft. In the revision setting, 24 (75%) physicians preferred a contralateral BPTB autograft, while 5 (16%) used an ipsilateral quadriceps autograft, 1 (3%) used a contralateral quadriceps autograft, and 2 (6%) used a BPTB allograft. One respondent (3%) used suture brace augmentation "most of the time" in the primary setting and always in the revision setting. No respondents utilized an ALL or LET in the primary setting and 2 (6%) respondents always performed an LET in revisions. Five others (16%) have performed at least 1 ALL or LET in an NFL athlete. Mean return to sports was at 9 months postoperatively, with no physicians allowing players to return before 7 months. All but 1 respondent used functional testing in return-to-sports decision-making.

Conclusion

All but 1 of the 32 NFL head team physicians used BPTB autograft in primary ACL reconstruction. The majority preferred contralateral BPTB autograft in revisions, with a few considering extra-articular procedures or suture bracing in addition. On average, head team physicians allowed players to return at 9 months postoperatively, with none allowing return before 7 months. Nearly all utilized functional testing to aid in return-to-play decision-making. These homogenous findings in this high-risk and public athletic cohort aid in patient education and clinical decision-making for best treatment of ACL injuries, particularly in contact athletes.

A Single-Surgeon 35-Year Experience With ACL Reconstruction Using Patellar Tendon Auto- and Allografts With the Transtibial Technique

Background

Long-term follow-up for anterior cruciate ligament reconstruction (ACLR) is limited due to heterogeneity in the number of techniques utilized, the number of surgeons included, and attrition bias.

Purpose

To analyze a single surgeon's 35-year experience with ACLR using the transtibial technique, with an emphasis on temporal trends in graft selection and subanalyses on rates of revision surgery, contralateral ACLR, and nonrevision reoperation among different demographic cohorts of patients.

Study Design

Case series; Level of evidence, 4.

Methods

All patients who underwent arthroscopically assisted single-bundle ACLR between 1986 and 2021 were identified from a prospectively maintained single-surgeon registry. Outcomes of interest included revision, reoperation, and contralateral rupture rates.

Results

A total of 2915 ACLRs were performed during the senior surgeon's career. The mean age for primary ACLR was 29.4 ± 14.8 years. During primary ACLR, 98.4% of patients received a central-third bone-patellar tendon-bone (BPTB) graft. Increasing patient age was associated with increasing allograft usage (P < .01), with a significant temporal increase in allograft usage over the senior surgeon's career (P < .01). There was a higher revision rate among younger patients (P < .01), female patients aged 21 to 25 years (P = .01), and patients who received an allograft during the primary procedure (P = .04). The contralateral rupture rate showed no difference between sexes (P = .34); however, patients who underwent ACLR with autograft had a greater rate of contralateral injury compared with those with allograft (P < .01). The contralateral rupture rate was greater than the revision rate (P < .01). The most common causes of nonrevision reoperation were failed meniscal repair, new meniscal tears, arthrofibrosis, and painful hardware removal.

Conclusion

The findings of this single-surgeon registry reveal temporal trends in ACLR over a 35-year career. There was a trend toward increasing BPTB allograft use in ACLR, especially in older patients and revision cases. A greater revision rate was observed among younger patients, female patients, and those receiving allografts during primary surgery. Contralateral ACLR was more common than revision surgery.

No Clinically Significant Differences in Outcomes After Anterior Cruciate Ligament Reconstruction When Comparing Quadriceps, Bone-Patellar Tendon-Bone, and Hamstring Autografts of 9 mm or Greater

PURPOSE

To determine whether there are patient-reported outcome differences in bone-patellar tendon-bone (BPTB), quadriceps tendon (QT), and hamstring (HS) grafts of comparable size.

METHODS

We performed a retrospective analysis of global registry data to include all patients who had an anterior cruciate ligament reconstruction with BPTB, QT, or HS autograft of at least 9 mm in diameter between 2010 and 2021 with complete 1- and 2-year outcome scores. We compared 1- and 2-year postoperative outcome scores (visual analog scale [VAS], Knee Injury and Osteoarthritis Outcome Score [KOOS] pain, Marx Activity Rating Scale [MARS], Veterans RAND 12-Item Health Survey [VR-12]) between BPTB, QT, and HS of the same size graft.

RESULTS

In total, 2,318 subjects were included in the analysis, and all graft types showed improved patient-reported outcome measures at 1 and 2 years postoperatively when compared with baseline. The KOOS pain score for the BPTB group was significantly better than the HS (between-group difference = 2.71, P < .01) and QT (between-group difference = 2.51, P < .01) groups at 1 year, and the BPTB group was better than HS (between-group difference = 1.88, P < .01) at 2 years. However, the differences were small and not clinically meaningful. When we compared graft type, there were no differences in the percentage of patients who reached Minimal clinically important difference, or clinical scores VAS or MARS at 2-year follow-up.

CONCLUSIONS

There is no clinically meaningful difference in KOOS-pain, VR-12, VAS, and MARS at 1 and 2 years postoperatively in patients having anterior cruciate ligament reconstruction with BPTB, HS, or QT if graft size is at least 9 mm in diameter.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Concomitant Medial Collateral Ligament Injury Increases the Risk of Revision Anterior Cruciate Ligament Reconstruction

PURPOSE

To compare rates of revisions between patients with isolated anterior cruciate ligament (ACL) reconstruction and those who had concomitant medial collateral ligament (MCL) injuries managed either operatively or nonoperatively at the time of index anterior cruciate ligament reconstruction (ACLR).

METHODS

Using laterality-specific International Classification of Diseases, Tenth Revision (ICD-10) and Current Procedural Terminology (CPT) codes, we queried the PearlDiver-Mariner Database for all patients who underwent ACLR between 2016 and 2020. Patients were included if they were ages 15 or older and had a minimum of 2 years of follow-up after index ACLR. Patients were then divided into cohorts by presence or absence of concomitant MCL injury. The cohort of concomitant MCL injuries was further subdivided into those with MCL injuries managed nonoperatively, with MCL repair, or with MCL reconstruction at the time of index ACLR. Multivariate regression was performed between cohorts to evaluate for factors associated with revision ACLR.

RESULTS

We identified 47,306 patients with isolated ACL injuries and 10,846 with concomitant MCL and ACL injuries. In total, 93% of patients with concomitant MCL injuries had their MCL treated nonoperatively; however, the annual proportion of patients being surgically managed for their MCL injury increased by 70% from 2016 to 2020. Concomitant MCL injury patients had greater odds of undergoing revision ACLR compared with patients with isolated ACL injuries (odds ratio 1.50, 95% confidence interval 1.36-1.66, P < .001). Among patients with concomitant MCL injuries, surgically managed patients had a greater risk of revision ACLR compared with nonoperatively managed MCL injuries (odds ratio 1.39, 95% confidence interval 1.01-1.86, P = .034).

CONCLUSIONS

Despite an increase in operatively managed concomitant MCL injuries, most concomitant MCL injuries were still managed nonoperatively at the time of ACLR. Patients with concomitant MCL injuries, particularly those managed operatively, at the time of ACLR are at increased risk of requiring revision ACLR compared with those with isolated ACL injuries.

LEVEL OF EVIDENCE

Level III, retrospective comparative case series.

A Lateral Extra-articular Procedure Reduces the Failure Rate of Revision Anterior Cruciate Ligament Reconstruction Surgery Without Increasing Complications: A Systematic Review and Meta-analysis

BACKGROUND

Lateral extra-articular procedures are becoming increasingly popular in association with anterior cruciate ligament (ACL) reconstruction, especially in patients with persistent rotatory instability and in a high-risk population. However, few studies have investigated the outcomes of the lateral extra-articular procedure as an associated procedure in an ACL revision (R-ACLR) setting and its benefit with respect to isolated intra-articular reconstruction.

HYPOTHESIS

Lateral extra-articular procedures reduce the failure rate of revision ACL reconstruction (R-ACLR).

PURPOSE

To compare subjective outcomes, knee stability, and failure and complication rates between patients who underwent ACL revision with and without an associated lateral extra-articular procedure.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 3.

METHODS

A systematic search of the PubMed, Cochrane, and OVID databases was performed on September 2022 in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Eligible studies were trials directly comparing patients who had isolated ACL revision with patients who had ACL revision associated with lateral extra-articular procedures at a minimum follow-up of 2 years. A meta-analysis was performed, and bias and the quality of the evidence were rated according to the Newcastle-Ottawa Scale. The meta-analysis was conducted according to the PRISMA guidelines.

RESULTS

Eight studies were included: a total of 334 patients were treated with isolated revision (isolated (R-ACLR)) and 342 treated with combined revision and a lateral extra-articular procedure (combined (R-ACLR)). For the failure rate, the meta-analysis showed a significantly decreased relative risk reduction of 54% (P = .004) in patients with combined (R-ACLR) with respect to isolated R-ACL, whereas no difference in complication rate was observed. The combined (R-ACLR) group demonstrated a decreased risk ratio of 50% (P = .002) for having a positive pivot-shift test result and a relative risk reduction of 68% (P = .003) for having a grade 2-3 pivot shift when compared with the isolated (R-ACLR) group. Finally, no significant differences were observed among the lateral extra-articular procedures.

CONCLUSION

The addition of a lateral extra-articular procedure to revision ACL significantly reduced the failure rate and postoperative pivot shift without increasing the complication rate. Anterolateral ligament reconstruction and a lateral extra-articular procedure with iliotibial band were effective in improving the outcomes of revision ACL reconstruction. Further high-level studies could help to clarify which subgroup of patients could particularly benefit from an anterolateral procedure in the context of ACL revision.

Evaluating the quality of systematic reviews of comparative studies in autograft-based anterior cruciate ligament reconstruction using the AMSTAR-2 tool: A systematic umbrella review

PURPOSE

There remains a lack of consensus around autograft selection in anterior cruciate ligament reconstruction (ACLR), though there is a large body of overlapping systematic reviews and meta-analyses. Systematic reviews and their methodological quality were aimed to be further assessed, using a validated tool known as assessing the methodological quality of systematic reviews (AMSTAR-2).

METHODS

MEDLINE, Embase and CENTRAL were searched from inception to 23 April 2023 for systematic reviews (with/without meta-analysis) comparing primary ACLR autografts. A final quality rating from AMSTAR-2 was provided for each study ('critically low', 'low', 'moderate' or 'high' quality). Correlational analyses were conducted for ratings in relation to study characteristics.

RESULTS

Two thousand five hundred and ninety-eight studies were screened, and 50 studies were ultimately included. Twenty-four studies (48%) were rated as 'critically low', 17 (34%) as 'low', seven (14%) as 'moderate' and two (4%) as 'high' quality. The least followed domains were reporting on sources of funding (1/50 studies), the impact of risk of bias on results of meta-analyses (11/36 studies) and publication bias (17/36 studies). There was a significant increase in the frequency of studies graded as 'moderate' compared to 'low' or 'critically low' quality over time (p = 0.020).

CONCLUSION

The methodological quality of systematic reviews comparing autografts in ACLR is low, with many studies being rated lower due to commonly absent aspects of systematic review methodology such as investigating sources of funding and publication bias. More recent studies were generally more likely to be of higher quality. Authors are advised to consult AMSTAR-2 prior to conducting systematic reviews in ACLR.

LEVEL OF EVIDENCE

Level IV.

Prospective study of functional outcomes and return to sports after anterior cruciate ligament reconstruction in the knee

PURPOSE

Individual factors of low rates of return to sport after anterior cruciate ligament (ACL) reconstruction were unclear. We evaluated the impact of various individual factors after ACL reconstruction for return to sport in athletes.

METHODS

A prospective study was performed in 1274 athletes, who had undergone ACL autograft reconstruction. Individual factors survey about return to sport was performed during the second year after surgery. Athlete responses were analyzed with a multivariate logistic model adjusted for baseline patient characteristics and an adjusted Cox model.

RESULTS

Younger age and involvement in higher-level sporting activities were associated with a significantly higher frequency and a significantly shorter time to return to sport (running, training, competition; p = 0.001 to 0.028). Men returned to sport more rapidly than women, for both training (p = 0.007) and competition (p = 0.042). Although there was no difference to return to sport between hamstring (HT) and patellar tendon (PT) autograft. We note that MacFL surgery (Mac Intosh modified with intra- and extra-articular autografts used the tensor fasciae latae muscle) was associated with a higher frequency (p = 0.03) and rapidity (p = 0.025) of return to training than HT. Sports people practicing no weight-bearing sports returned to training (p < 0.001) and competition (p < 0.001) more rapidly than other sports people. By contrast, the practicing pivoting sports with contact started running again sooner (p < 0.001).

CONCLUSION

Younger age, male sex, higher level of sports, sportspeople practicing no weight-bearing sports, and MacFL surgery reduce time to return to sport after ACL reconstruction.

Does combined anterior cruciate ligament and anterolateral ligament reconstruction improve return to sport?

PURPOSE

Only 50-65% of patients return to their previous sporting level after ACL rupture. The literature reports a reduced rate of graft rupture when an anterolateral ligament reconstruction (ALLR) is associated with ACL reconstruction. ACL reconstruction combined with ALL allows a higher return to sport at pre-injury level than isolated reconstruction in patients playing pivot-contact sports.

METHODS

A retrospective, single-centre study between 2012 and 2020 comparing reconstruction by hamstring tendon technique, isolated ACLR vs ACL with ALLR. An isokinetic test was performed at 6 months post-operatively and patients were re-contacted at a minimum 2-year follow-up to assess their level and delay to return to sport, graft rupture rate and functional evaluation.

RESULTS

83 patients were included, 42 in ACLR group and 41 in ACL + ALLR group. Four patients were lost to follow-up and 79 patients were analysed. No significant difference was found on the level of return to sport (28.2% vs. 42.5%; p = 0.18), return to competition (43% vs. 60%; p = 0.18), delay to sports return, isokinetic assessment, functional scores, but a significant difference was found on graft rupture rate in favour of ALLR (12.8% vs. 0%; p = 0.02).

CONCLUSION

In our study, the addition of an ALL to ACL reconstruction did not improve pre-injury sports recovery or return to competition.

STUDY DESIGN

Cohort study, level of evidence 4.

Morphology of the quadriceps tendon and its patella insertion site on three-dimensional computed tomography and magnetic resonance imaging: A cadaveric study

AIM

This study was conducted to clarify the morphological properties of the quadriceps tendon (QT) and its patella insertion site using three-dimensional computed tomography and magnetic resonance imaging.

METHODS

Twenty-one right knees from human cadavers were evaluated using three-dimensional computed tomography and magnetic resonance imaging. The morphologies of the QT and its patella insertion site were evaluated, along with intra-tendon differences in length, width, and thickness.

RESULTS

The QT insertion site on the patella was dome-shaped without characteristic bony features. The mean surface area of the insertion site was 502.5 ± 68.5 mm2 (range, 336.0-610.7). The QT was longest 2.0 mm lateral to the central width of the insertion and gradually became shorter toward both edges (mean length, 59.7 ± 8.3 mm). The QT was widest at the insertion site (mean width, 39.1 ± 5.3 mm) and gradually became narrower toward the proximal side. The QT was thickest 2.0 mm medial to the center (mean thickness, 11.4 ± 1.9 mm).

CONCLUSION

The morphological properties of the QT and its insertion site were consistent. The characteristics of the QT graft depend on the harvested region.

Accuracy of Femoral Tunnel Localization With Mixed Reality Technology-Assisted Single-Bundle ACL Reconstruction

Background

It is clinically challenging to accurately drill femoral and tibial tunnels to reconstruct the anterior cruciate ligament (ACL). Mixed reality (MR) technology, a further development of virtual reality technology, presents virtual scene information in real time and establishes an interactive feedback information loop among the real world, the virtual world, and the user.

Purpose/Hypothesis

The purpose of this study was to investigate the structural and early clinical outcomes of ACL reconstruction assisted by MR technology. It was hypothesized that MR technology would improve the accuracy of tunnel localization.

Study Design

Cohort study; Level of evidence, 3.

Methods

Included were 44 patients at a single institution who underwent arthroscopic single-bundle ACL reconstruction between June 2020 and March 2022. Reconstruction with the aid of MR technology was performed in 21 patients (MR group), and conventional arthroscopic reconstruction was performed in 23 patients. Postoperatively, the parameters related to the bone tunnel positioning were compared by computed tomography imaging with 3-dimensional (3D) reconstruction, and 12-month postoperative clinical outcomes were assessed with the Lysholm and International Knee Documentation Committee scores.

Results

There was no statistically significant difference in projection angles in the coronal, axial, or sagittal plane between the preoperative virtually created tunnel guide pin and the actual tunnel (P > .05 for all). In the MR group, the center of the femoral tunnel exit was closer to the apex of the lateral femoral condyle along the proximal-distal axis (14.07 ± 4.12 vs 17.49 ± 6.24 mm for the conventional group; P < .05) and the graft bending angle was lower (117.71° ± 8.08° vs 127.81° ± 11.91° for the conventional group; P < .05). The scatterplot of the femoral tunnel location distribution showed that the entrance and exit points in the MR group were more concentrated and closer to the ideal location of the preoperative design than in the conventional group. Patients in both groups had significant preoperative-to-postoperative improvement based on outcome scores (P < .001 for all), with no significant difference between groups.

Conclusion

ACL reconstruction with the aid of MR technology allowed for more accurate positioning and orientation of the femoral tunnel during surgery when compared with conventional reconstruction.

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.

Tunnel Management in Revision Anterior Cruciate Ligament Reconstruction: Current Concepts

Bone tunnel-related complications are frequently encountered during revision anterior cruciate ligament reconstruction (ACLR). Issues with tunnel positioning, enlargement, containment, and hardware interference may complicate surgery and compromise outcomes. As a result, several strategies have emerged to address these issues and optimize results. However, a systematic, unified approach to tunnel pathology in revision ACLR is lacking. The purpose of this review is to highlight the current state of the literature on bone tunnel complications and, although extensive literature on the subject is lacking, present an updated approach to the evaluation and management of tunnel-related issues in revision ACLR.

Rebranding the 'anatomic' ACL reconstruction: Current concepts

The anterior cruciate ligament (ACL) is a complex ribbon-like structure, which is approximately 3.5 times larger at the tibial and femoral insertions than at the midpoint. Accordingly, it is impossible to recreate with a single cylindrical graft. However, this has not stopped surgeons from using the term "anatomic" to describe multiple ACL reconstruction techniques inserting at a number of different locations within the original ACL footprint, causing confusion. The term "anatomic" should be discarded and replaced by an anatomic description of the tunnel placements on the tibia and femur. Current ACL reconstruction techniques cite anatomical studies that identified "direct and indirect fibres" of the ACL. The "direct fibres" bear 85-95% of the load and provide the main resistance to both anterior tibial translation and internal rotation/pivot shift. On the femur, these fibres insert in a line just posterior to the intercondylar ridge and comprise the portion of the ACL that surgeons should strive to restore. Placement of the graft just posterior to the intercondylar ridge creates a line of placement options from the anteromedial bundle to the "central" position and finally to the posterolateral bundle position. The authors prefer placing the femoral tunnel in the isometric anteromedial position and addressing a high-grade pivot shift at the IT-band with a lateral extra-articular tenodesis. As with the femoral tunnel, the native ACL footprint on the tibia is much larger than the ACL graft and thus can be placed in multiple "anatomic" locations. The authors prefer placement of the tibial tunnel in the anterior most position of the native footprint that does not cause impingement in the femoral notch. Additional research is needed to determine the ideal tunnel positions on the femur and tibia and validating the technique with patient outcomes. However, this cannot be accomplished without describing tunnel placement with specific anatomical locations so other surgeons can replicate the technique.

Comparative analysis of the results of the anterior cruciate ligament reconstruction using an autograft preparation by known and new methods

Background. To date, the problem of choosing the optimal graft for anterior cruciate ligament (ACL) reconstruction and the methods for its formation is one of the main trends in the surgical treatment of patients with anterior knee joint instability.The aim. To compare the results of the anterior cruciate ligament reconstruction using the known method and the new proposed method for autograft formation.Materials and methods. The results of treatment of ACL injury in 44 patients were assessed. In the main group (19 patients), an original technique of ACL reconstruction from 1/2 of the width of m. peroneus longus tendon was used. In the control group (25 patients), ACL reconstruction was performed using a graft from the m. semitendinosus tendon prepared by the Lubowitz method.Results. The mean difference in the circumference of the distal third of the hip in the main group was 1.57 ± 1.162 cm and was statistically significantly better than in the control group, where the mean difference in the hip circumference was 4.74 ± 1.7207 cm.The range of motion of the knee joint in the main group 3 months after the surgery was 128.42 ± 9.287°, and in the control group mean flection was 109.6 ± 9.120°.The functional results in the main group were assessed by the Lisholm scale and were statistically significantly better than the results in the control group. The functional results by the AOFAS (American Orthopedic Foot & Ankle Society) scale in the main group were 100 points before the surgery and at all terms after the surgery: this indicates that the use of 1/2 of the width of m. peroneus longus tendon does not cause the its functional impairement.Conclusion. Anterior cruciate ligament plasty with use of 1/2 of the width of m. peroneus longus tendon prepared by the proposed method showed statistically significantly better results compared to the preparation of autograft from semitendinous muscle tendon using known method.

Revision Rates After Primary ACL Reconstruction Performed Between 1969 and 2018: A Systematic Review and Metaregression Analysis

Background:

Numerous studies, including randomized controlled trials (RCTs), have been published on the optimal graft choice for primary anterior cruciate ligament (ACL) reconstruction.

Purpose:

To review existing studies to investigate whether advances in orthopaedics have affected revision rates after primary ACL reconstruction.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

The PubMed database was searched from inception to December 31, 2020, using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Patient series, observational studies, clinical trials, and registry-based studies investigating primary ACL reconstruction were included, as were high-quality RCTs from an additional study. The minimum required follow-up time for inclusion was 1 year. The primary outcome measure was the pooled prevalence of revision ACL reconstruction. The effect of the year the surgery was performed on revision rates was evaluated with metaregression analysis. All graft types were analyzed simultaneously, and all analyses were repeated separately for each graft type.

Results:

Overall, 330 articles with 52,878 patients were included, with a median patient age of 28 years (range, 15-57 years). The primary ACL reconstructions were performed between 1969 and 2018. At a median of 2.3 years of follow-up, the overall revision rate was 3.14% (95% CI, 2.76% to 3.56%); it was 2.71% (95% CI, 2.25% to 3.27%) for hamstring autografts, 2.38% (95% CI, 1.82% to 3.11%) for bone–patellar tendon–bone (BPTB) autografts, and 5.24% (95% CI, 4.02% to 6.80%) for other graft types. For hamstring grafts, the revision rate increased over time (year of surgery), with a 0.0434 (95% CI, 0.0150 to 0.0718) increase effect in the logit-transformed scale for every additional year. There was a slight decrease in revision rates for BPTB (β = –0.0049; 95% CI, –0.0352 to 0.0254) and other graft types (β = –0.0306; 95% CI, –0.0608 to −0.0005) over time; however, confidence intervals for BPTB included the zero change.

Conclusion:

Based on this systematic review and meta-analysis, ACL reconstruction is a reliable procedure with overall low historical revision rates. BPTB autograft had the lowest revision rate and a slightly decreasing trend of failures during the past 45 years, although both BPTB and hamstring autografts are reliable graft choices.

Young men are at higher risk of failure after ACL hamstring reconstructions: a retrospective multivariate analysis

Background

Results of ACL reconstruction are influenced by both patient and surgical variables. Until now a significant amount of studies have focused on the influence of surgical technique on primary outcome, often leaving patient variables untouched. This study investigates the combined influence of patient and surgical variables through multivariate analysis.

Methods

Single-center retrospective cohort study. All patients who underwent primary ACL hamstring reconstruction within a 5-year period were included. Patient characteristics (gender, age, height, weight, BMI at time of surgery) and surgical variables (surgical technique, concomitant knee injury, graft diameter, type of femoral and tibial fixation) were collected. Patients were asked about Tegner Activity Scale (TAS), complications and revision surgery. Multivariate logistic regression was used to study risk factors. First graft failure and potential risk factors (patient and surgical) were univariately assessed. Risk factors with a p-value ≤ 0.05 were included in the multivariate model.

Results

Six hundred forty-seven primary ACL hamstring reconstructions were included. There were 41 graft failures (failure rate 6.3%). Patient gender, age, height and preoperative TAS had a significant influence on the risk of failure in the univariate analysis. The multivariate analyses showed that age and sex remained significant independent risk factors. Patients with a failed ACL reconstruction were younger (24.3 vs 29.4 years, OR 0.937), with women at a lower risk for failure of their ACL reconstruction (90.2% males vs 9.8% females, female OR 0.123). ACL graft diameter and other surgical variables aren’t confounders for graft failure.

Conclusion

This study shows that patient variables seem to have a larger influence on the failure rate of ACL hamstring reconstructive surgery than surgical variables. Identification of the right patient variables can help us make more informed decisions for our patients and create patient-specific treatment protocols. Young men’s higher risk of failure suggests that these patients may benefit from a different reconstruction technique, such as use of a patellar tendon or combined ligament augmentation.

Level of evidence

Retrospective cohort III.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05547-8.

Anterior Cruciate Ligament Reconstruction in 107 Competitive Wrestlers: Outcomes, Reoperations, and Return to Play at 6-Year Follow-up

Background

Wrestling is a physically demanding sport, with young athletes prone to anterior cruciate ligament (ACL) injuries. There is a paucity of data evaluating the results of ACL reconstruction (ACLR) in this cohort.

Purpose

To assess return to sport (RTS), patient-reported outcomes, reoperation rates, and graft survival after ACLR in a large cohort of competitive wrestlers at midterm follow-up.

Study Design

Case series; Level of evidence, 4.

Methods

We identified all competitive wrestlers (club, high school, collegiate, or professional) with a history of an ACLR at a single institution between 2000 and 2019. Graft failure was defined as a retear (as determined via clinical or advanced imaging evaluation) and/or revision ACLR. All patients were contacted for determination of reinjury rates; current sport status; and pain visual analog scale, International Knee Documentation Committee, and Tegner activity scores.

Results

Included were 107 knees in 103 wrestlers, with a median follow-up time of 5.9 years (interquartile range [IQR], 3.9-10.3 years). The median age was 17 years (IQR, 15-18 years), with 106 (99%) male patients, and the distribution of bone-patellar tendon-bone (BTB) and hamstring tendon (HT) autografts was 64 (60%) and 43 (40%), respectively. At final follow-up, 80% of athletes were able to RTP at a median of 280 days (IQR, 212-381 days). Graft failure occurred in 14 (13%) knees at a median time of 1.8 years (IQR, 0.7-5.3 years) after the index ACLR. BTB autograft demonstrated a lower failure rate compared with HT autograft (8% vs 21%; P = .044) and was associated with better survival compared with HT autograft up to 15 years after the index ACLR (90.4% vs 76.3%; P = .030). When compared by graft diameter, HT autografts of at least 7.5 mm were not associated with a lower graft failure than BTB constructs of all sizes (P = .205).

Conclusion

Return to competitive wrestling was observed in 80% of athletes after ACLR, with 14% of wrestlers experiencing graft failure. BTB autograft was associated with better survival than HT autograft.

Biological enhancement methods may be a viable option for ACL arthroscopic primary repair - A systematic review

BACKGROUND

Bioactive factors combined with advanced anterior cruciate ligament (ACL) primary repair technology have been used to treat ACL repairs. The current review was conducted to identify whether biological enhancement could enable superior clinical outcome, including side-to-side difference, failure rate, reoperation rate and subjective scores.

HYPOTHESIS

The implementation of ACL primary repair with biological enhancement will provide better clinical outcomes in terms of side-to-side differences, failure rate, reoperation rate and subjective scores than ACL primary repair alone.

MATERIALS AND METHODS

A systematic literature review was performed following PRISMA guidelines by searching all studies reporting outcomes of arthroscopic primary repair with or without biological augmentation published until April 19, 2020, in Medline, PubMed, Embase and the Cochrane Library. Primary metrics were side-to-side differences, failure rate and reoperation rate, as well as measurements of patient-reported outcomes at the last follow-up.

RESULTS

A total of 20 studies were finally included in this work, of which 3 were Grade I (15%), 3 studies were Grade III (15%), and 14 studies were Grade IV (70%) in terms of the level of evidence. There were 729 patients with a mean age of 30 (range: 8-68) years, and the mean follow-up period of which was 38 (range: 3-122) months. At the final follow-up, the postoperative side-to-side differences (the proportion of patients with a side-to-side difference less than 3mm) and patient-report outcomes were significantly better in the biological enhancement group. Nevertheless, there were no significant differences between the two groups in the rate of surgical failure, the rate of revision, or the positive Lachman test or pivot shift test.

CONCLUSION

Biologically enhanced arthroscopic ACL primary repair was superior to ACL primary repair alone in terms of postoperative side-to-side differences (proportion of patients with a side-to-side difference less than 3mm) and patient-reported outcomes. Thus, biologically enhanced arthroscopic ACL primary repair can be preferentially recommended over ACL arthroscopic primary repair alone.

LEVEL OF EVIDENCE

IV, systematic review.

Graft Choice for Anterior Cruciate Ligament Reconstruction in Women Aged 25 Years and Younger: A Systematic Review

CONTEXT

Although anterior cruciate ligament (ACL) tears are relatively common in athletic populations, few studies have systematically reviewed graft choice in young women.

OBJECTIVE

To quantitatively and qualitatively examine reported outcomes for graft choice in women aged 25 years and younger undergoing primary ACL reconstruction.

DATA SOURCE

A systematic review was performed using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. An electronic search in the PubMed (includes MEDLINE) and EMBASE databases was completed using a combination of key terms.

STUDY SELECTION

Studies were included if they reported graft choice outcomes in women aged 25 years and younger.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 4.

DATA EXTRACTION

The following information was extracted: title, author, year of publication, number of female patients and age, graft type, follow-up, and patient-reported outcome measures. The following outcome scores were identified as being reported or not reported by each study: graft failure, contralateral ACL (CACL) rupture, IKDC (International Knee Documentation Committee), graft survival (Kaplan-Meier), Lysholm, Tegner, KT-1000, kneeling pain, return to sport, and Lachman.

RESULTS

Of 1170 identified articles, 16 met inclusion criteria, reporting on 1385 female patients aged 25 years and younger. Comparison of 655 bone-patellar tendon-bone (BPTB) versus 525 hamstring tendon (HT) autografts showed significant differences in mean failure rate between BPTB autografts (6.13% ± 2.58%) and HT autografts (17.35% ± 8.19%), P = 0.001. No statistically significant differences in CACL failure rates were found between BPTB autografts and HT autografts (P = 0.25). Pooled results for IKDC were possible in 3 of the HT autograft studies, showing a mean score of 88.31 (95% CI 83.53-93.08). Pooled Lysholm score results were possible in 2 of the HT autograft studies, showing a mean score of 93.46 (95% CI 91.90-95.01).

CONCLUSION

In female patients aged 25 years and younger, BPTB autografts showed significantly less graft failure compared with HT autografts. However, BPTB autografts had comparable patient-reported outcomes compared with HT autografts with the available data. The overall state of evidence for graft choice in female patients aged 25 years and younger is low. Future studies should report statistics by age and sex to allow for further analysis of graft choice for this specific population that is known to be more vulnerable to ACL injury.

Suture tape reinforcement of hamstring tendon graft reduces postoperative knee laxity after primary ACL reconstruction

Purpose

To evaluate and compare subjective and objective knee outcomes following hamstring tendon (HT) and quadriceps tendon (QT) anterior cruciate ligament reconstruction (ACLR) with or without suture tape (ST) reinforcement. It was hypothesized that the addition of an intra-articular synthetic augmentation with a ST would reduce postoperative knee laxity and graft ruptures after ACLR.

Methods

A 1:1 matched-cohort comparison of patients who underwent HT and QT autograft ACLR with or without ST reinforcement was performed. Patients with ST reinforcement were consecutively assigned to the study groups until a number of 20 in each group was achieved. Medical records were reviewed for demographic characteristics and additional injuries. Laxity measurements with KT-1000, strength measurements and physical examination findings were collected both preoperatively and at 6 months and patient reported outcome (PRO) scores were collected both preoperatively and at 12 months, and comparison was made HT vs HT + ST and QT vs QT + ST. Reoperations and re-ruptures were recorded during the 24-month follow-up period.

Results

Overall, 80 patients who underwent ACLR were included. Patients with HT + ST had significant less laxity postoperatively compared to HT at 6 months, 1.9 vs 0.8 mm, p < 0.05. No differences were found between the QT and QT + ST group. At 6 weeks patients treated with ST, both QT and HT, had a significant deficit in flexion compared to those without ST. However, this resolved at 6 months. There were no significant differences between HT + ST vs HT, or QT + ST vs QT, regarding postoperative PROs or strength measurements. Furthermore, the incidence of subsequent surgery and graft rupture was not significantly different between the groups.

Conclusion

ACLR with HT + ST reduces laxity at 6 months compared to ACLR without ST, a difference not seen when ACLR was performed using QT with or without ST. No other differences were seen between the two techniques comparing subjective and objective findings.

Level of evidence

Level III.

Comparison of Bone-Patella Tendon-Bone and Four-Strand Hamstring Tendon Grafts for Anterior Cruciate Ligament Reconstruction: A Prospective Study

Introduction

To date, the proper choice of graft for anterior cruciate ligament (ACL) reconstruction remains a matter of conflict. We aimed to compare the clinical and functional outcomes of the two most commonly utilized autografts, bone-patella tendon-bone (BPTB) and four-strand hamstring tendon (HT) graft, at 6 and 12 months after surgery.

Methods

In a prospective randomized study, we included a total of 60 patients undergoing ACL reconstruction, thirty in BPTB and thirty in HT group. All patients were amateur athletes and were evaluated at 6 and12 months after surgery for: (a)postoperativefunctionality of the operated knee by the Tegner, the Lysholm and the International Knee Documentation Committee (IKDC) scoring scales, (b) anterior cruciate ligament (ACL) instability of the operated knee compared to the healthy contralateral knee by the KT-1000 arthrometer and (c) theextension and flexion muscle strength of the operated knee by a CYBEXisokinetic dynamometer. 

Results

Patients in the two groups did not differ regarding demographics, and pre-injury functionality status. Significantly more patients in the HT group (n=6) compared to the BPTB group (n=1) experienced ACL re-rupture and underwent revision surgery before follow-up end (p=0.044). All patients, regardless of graft, showed significant improvement within each group of functional assessments by Lysholm, Tegner and IKDC scores, as well as of Cybex measurements -with an increase of peak torque at 60° extension and 180°extension and 60° flexion and 180° flexion- at 12 months compared to 6 months follow-up (p<0.05). However, there was no difference between the two groups regarding knee function improvement or extension measurements neither at 6 nor 12 months. Contrarily, the BPTB graft group had higher values of peak torque (Nm) at 60° and 180° flexion compared to the HT group, both at 6 (p=0.014 and 0.029, respectively) and 12 months (p=0.033 and 0.030, respectively). Postoperative stability was similar between the two groups at 12 months (p=0.519).

Conclusion

Both BPTB and HT grafts present with benefits and drawbacks and remain viable autograft options for primary ACL reconstruction as each has, although HT grafts seem to be more susceptible to re-rupture. The graft selection should be based on the needs and activities of each patient. 

Patients Aged 50 Years and Older Have Greater Complication Rates After Anterior Cruciate Ligament Reconstruction: A Large Database Study

Purpose

To assess the use of anterior cruciate ligament (ACL) reconstruction in older adults and to compare postoperative complication and revision surgery rates between patients older than and younger than 50 years old.

Methods

Retrospective data were obtained using the PearlDiver database for patients who underwent arthroscopic ACL reconstruction from January 2010 to December 2017. Trends in the annual performance of ACL reconstruction were determined using nonparametric test of trends of ranks. Patients in each age group were matched based on sex and the Charlson Comorbidity Index. The incidence of postoperative complications within 90 days and subsequent knee surgery within 2 years of ACL reconstruction was collected. Postoperative complication rates were compared between matched age groups using the χ² test.

Results

A total of 20,993 patients aged 50 years and older and 154,817 patients younger than 50 years underwent ACL reconstruction between 2010 and 2017. The use of ACL reconstruction in patients aged 50 years or older decreased over time (P = .044). Patients aged 50 years or older were more likely to experience at least 1 postoperative complication within 90 days compared to patients younger than 50 years (2.5% vs 2.1%, P = .007). Older patients were 1.3 times as likely to experience deep vein thrombosis (P = .002) and 1.8 times as likely to experience pulmonary embolism (P < .001). Younger patients were more likely to undergo subsequent ACL reconstruction and experience knee pain, stiffness, and wound infection postoperatively (P < .001, P < .001, P = .041). 1.6% of patients aged 50 years or older underwent total knee arthroplasty within 2 years.

Conclusions

ACL reconstruction in patients aged 50 years or older is associated with greater complication rates but lower rates of subsequent knee surgery relative to patients younger than 50 years of age. Younger patients were more prone to surgical complications whereas older patients experienced more medical complications. The increased incidence of VTE in this population suggests that thrombotic prophylaxis may be considered.

Level of Evidence

Level III, retrospective comparative observational trial.

ACL Study Group survey reveals the evolution of anterior cruciate ligament reconstruction graft choice over the past three decades

PURPOSE

Anterior cruciate ligament reconstruction (ACLR) aims to restore knee function and stability, allowing patients to return to the activities they enjoy and minimize further injury to the meniscus and cartilage and their ultimate progression to osteoarthritis. This study aims to present the evolution of graft choice over the last three decades according to members of the ACL Study Group (SG).

METHODS

Prior to the January 2020 ACL SG biannual meeting, a survey was administered consisting of 87 questions and 16 categories, including ACLR graft choice. A similar questionnaire has been administered prior to each meeting and survey results from the past 14 meetings (1992 through 2020, excluding 1994) are included in this work. Survey responses are reported as frequencies in percentages to quantify changes in practice over the surgery period.

RESULTS

In 1992, the most frequent graft choice for primary ACLR was bone-patellar tendon-bone (BTB) autograft, at nearly 90%. Hamstring tendon (HT) autografts have increased in popularity, currently over 50%, followed by just under 40% BTB autograft. Recently, quadriceps tendon (QT) autograft has increased in popularity since 2014.

CONCLUSION

Autograft (HT, BTB, QT) is an overwhelming favorite for primary ACLR over allograft. The preference for HT autograft increased over the study period relative to BTB autograft, with QT autograft gaining in popularity in recent years. Graft selection should be individualized for each patient and understanding the global trends in graft choice can help orthopaedic surgeons discuss graft options with their patients and determine the appropriate graft for each case.

LEVEL OF EVIDENCE

Level V, Expert Opinion.

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).

A Systematic Approach for Stronger Documentation of Anterior Cruciate Ligament Graft Choice

Numerous studies have focused on determining the optimal choice between the two most used anterior cruciate ligament (ACL) reconstruction autografts. In order to address this matter, we performed a systematic review of every meta-analysis published on the PubMed platform between 2001 and 2020, comparing the functional outcomes, the static stability parameters, as well as the postoperative and long-term complications of the patellar tendon (BPTB) autograft and hamstrings (HT). We retrieved a total of 26 meta-analyses that met our criteria, and the characteristics and outcomes of every meta-analysis, as well as subgroup analysis regarding the type of the study design, number of strands of HT autograft, and fixation method, were extensively recorded. The majority of the meta-analyses showed that there were no significant differences between BPTB and HT in terms of functional outcomes and static stability parameters while HT autografts seem to be superior to BPTB regarding kneeling pain and anterior knee pain. Other outcomes seem to be affected by the number of strands of the HT autograft, the fixation technique, and the type of study design, indicating superiority of the four-strand HT autograft with the use of an extra-cortical button fixation. Overall, there is no clear superiority of BPTB over HT autografts for ACL reconstruction, as both types present similar outcomes in the majority of postoperative parameters. Autograft selection should be individualized according to each patient's needs and more RCTs are warranted in order to reach safer results on the appropriate autograft type.

Risk Factors for Requiring a Revision Anterior Cruciate Ligament Reconstruction: A Case-Control Study

Anterior cruciate ligament (ACL) reconstruction is considered as a successful orthopaedic procedure that attempts to help patients return to their preinjury level of activity. However, some patients may need to undergo revision surgery, and this potentially may be associated with certain surgery-specific or patient risk factors. Therefore, the purpose of this study was to assess the potential role of (1) demographics, (2) family history, (3) graft choice, (4) sport, and (5) mechanism of injury (contact vs. noncontact) in the risk for needing a revision ACL for improved clinical outcomes. All patients who had undergone a primary ACL reconstruction between 2012 and 2016 were identified from at a single institution. About 312 patients who had a mean age of 24 years (range, 9-62 years) and a mean follow-up of 4 years (range, 1-10). Patients were further evaluated to identify those who had a revision. There were 19 patients (6.1%) with a mean age of 22 years (range, 13-38 years) and a mean follow-up of 5 years (range, 1-10) that required a revision reconstruction. Gender ratios (p = 0.56) and mean age (p = 0.44) were similar among the cohorts. Family history of ACL reconstruction had no association with revision risk (p = 0.57). Those with tibialis anterior allografts (37 vs. 4%; p = 0.0001) and hamstring allografts (16 vs. 1%; p = 0.0001) were far more likely to undergo a revision. Bone-tendon-bone (BTB) patella autografts were less likely (26 vs. 73%; p = 0.0001). Sport did not play a role in revision with those injured playing basketball (p = 0.61), football (p = 0.52), lacrosse (p = 0.52), soccer (p = 0.83), and volleyball (p = 0.61). There were a greater percentage of contact injuries that required revision (95 vs. 77%; p = 0.07). Graft selection played a significant role in requiring revision surgery with allografts portending to higher revision rates and BTB patella autografts conferring a lower risk.

Influence of femoral tunnel exit on the 3D graft bending angle in anterior cruciate ligament reconstruction

Purpose

To quantify the influence of the femoral tunnel exit (FTE) on the graft bending angle (GBA) and GBA-excursion throughout a full range of motion (ROM) in single-bundle anterior cruciate ligament (ACL) reconstruction.

Methods

Three-dimensional (3D) surface models of five healthy knees were generated from a weight-bearing CT obtained throughout a full ROM (0, 30, 60, 90, 120°) and femoral and tibial ACL insertions were computed. The FTE was simulated for 16 predefined positions, referenced to the Blumensaat's line, for each patient throughout a full ROM (0, 30, 60, 90, 120°) resulting in a total of 400 simulations. 3D GBA was calculated between the 3D directional vector of the ACL and the femoral tunnel, while the intra-articular ACL insertions remained unchanged. For each simulation the 3D GBA, GBA-excursion, tunnel length and posterior tunnel blow-out were analysed.

Results

Overall, mean GBA decreased with increasing knee flexion for each FTE (p < 0.001). A more distal location of the FTE along the Blumensaat's line resulted in an increase of GBA and GBA-excursion of 8.5 ± 0.6° and 17.6 ± 1.1° /cm respectively (p < 0.001), while a more anterior location resulted in a change of GBA and GBA-excursion of -2.3 ± 0.6° /cm (+ 0.6 ± 0.4°/ cm from 0–60° flexion) and 9.8 ± 1.1 /cm respectively (p < 0.001).

Mean tunnel length was 38.5 ± 5.2 mm (range 29.6–50.5). Posterior tunnel blow-out did not occur for any FTE.

Conclusion

Aiming for a more proximal and posterior FTE, with respect to Blumensaat’s line, reliably reduces GBA and GBA-excursion, while preserving adequate tunnel length. This might aid to reduce excessive graft stress at the femoral tunnel aperture, decrease femoral tunnel widening and promote graft-healing.

Level of Evidence

IV

Return to Sport After ACL Reconstruction With a BTB Versus Hamstring Tendon Autograft: A Systematic Review and Meta-analysis

Background

Anterior cruciate ligament (ACL) tears are debilitating injuries frequently suffered by athletes. ACL reconstruction is indicated to restore knee stability and allow patients to return to prior levels of athletic performance. While existing literature suggests that patient-reported outcomes are similar between bone-patellar tendon-bone (BTB) and hamstring tendon (HT) autografts, there is less information comparing return-to-sport (RTS) rates between the 2 graft types.

Purpose

To compare RTS rates among athletes undergoing primary ACL reconstruction using a BTB versus HT autograft.

Study Design

Systematic review; Level of evidence, 4.

Methods

The MEDLINE, Embase, and Cochrane Library databases were searched, and studies that reported on RTS after primary ACL reconstruction using a BTB or HT autograft were included. Studies that utilized ACL repair techniques, quadriceps tendon autografts, graft augmentation, double-bundle autografts, allografts, or revision ACL reconstruction were excluded. RTS information was extracted and analyzed from all included studies.

Results

Included in the review were 20 articles investigating a total of 2348 athletes. The overall RTS rate in our cohort was 73.2%, with 48.9% returning to preinjury levels of performance and a rerupture rate of 2.4%. The overall RTS rate in patients after primary ACL reconstruction with a BTB autograft was 81.0%, with 50.0% of athletes returning to preinjury levels of performance and a rerupture rate of 2.2%. Patients after primary ACL reconstruction with an HT autograft had an overall RTS rate of 70.6%, with 48.5% of athletes returning to preinjury levels of performance and a rerupture rate of 2.5%.

Conclusion

ACL reconstruction using BTB autografts demonstrated higher overall RTS rates when compared with HT autografts. However, BTB and HT autografts had similar rates of return to preinjury levels of performance and rerupture rates. Less than half of the athletes were able to return to preinjury sport levels after ACL reconstruction with either an HT or BTB autograft.

Patellar Tendon Versus 4-Strand Semitendinosus and Gracilis Autografts for Anterior Cruciate Ligament Reconstruction: A Meta-analysis of Randomized Controlled Trials With Mid- to Long-Term Follow-Up

PURPOSE

To compare patellar tendon (PT) autografts with 4-strand semitendinosus and gracilis (STG) autografts concerning knee stability, functional outcomes, as well as complications after anterior cruciate ligament (ACL) reconstruction at minimal follow-up of 5 years.

METHODS

A systematic search of the literature was performed in PubMed, Embase, and the Cochrane Library to identify published prospective randomized controlled trials on clinical studies comparing PT autograft and 4-strand STG autografts for ACL reconstruction. The results of the eligible studies were analyzed in terms of knee stability (laxity measurements, Lachman test, and pivot-shift test), functional outcomes (Lysholm score, International Knee Documentation Committee score, Cincinnati score, Tegner score, single-legged hop test, and return to preinjury activity level), and complications (loss of range of motion [ROM], pain, graft re-rupture, revision, and osteoarthritis [OA]).

RESULTS

Nine clinical studies with 630 patients (313 PT and 317 STG autografts) met the inclusion criteria. No statistically significant differences were found between the PT and STG group in Lachman test, pivot-shift test, International Knee Documentation Committee score, Cincinnati score, loss of ROM, kneeling pain, graft re-rupture rate, revision rate, and OA rate. The STG group was found with less anterior knee pain (P = .003). There were no clinically significant differences for the outcomes of SSD, Lysholm score, and Tegner score.

CONCLUSIONS

Except for significantly greater risk of anterior knee pain, PT autograft had comparable results with 4-strand STG autograft in terms of knee stability and functional outcomes after ACL reconstruction with mid- to long-term follow-up. Besides, we found no statistically significant difference in loss of ROM, kneeling pain, graft re-rupture rate, revision rate, and OA change, but these results were underpowered.

LEVEL OF EVIDENCE

Level I, meta-analysis of Level I studies.

Does Bone Plug and Graft Orientation (Inferior Versus Posterior) Alter Native Femoral Footprint Coverage in Bone Patellar Tendon Bone Anterior Cruciate Ligament Reconstruction?

PURPOSE

The purpose of this study was to compare the percentage of native femoral anterior cruciate ligament (ACL) footprint covered by the 2 most clinically relevant bone plug/graft orientations used with interference screw fixation in ACL reconstruction. A secondary purpose was to assess whether a transtibial or tibia-independent drilling technique would affect this outcome.

METHODS

Five matched pairs of cadaver knees were used. Each matched pair had 1 knee assigned to a 10-mm femoral socket prepared via a transtibial (TT) drilling technique and the other via an anteromedial (AM) drilling technique. The bone plug of each graft was press-fitted into the femoral socket with the graft collagen in 2 distinct clinically relevant orientations (collagen inferior or posterior). The digitized graft collagen cross-sectional area (CSA) in each orientation was overlaid onto the native femoral ACL footprint CSA to generate a percentage of native ACL footprint covered by graft collagen.

RESULTS

The average native ACL femoral footprint CSA was 110.5 ± 9.1 mm², with no difference between knees assigned to TT or AM drilling (112.6 ± 2.7 vs 108.4 ± 13.0 mm², P = .49). The average femoral socket CSA was 95.4 ± 8.7 mm², with no difference between TT and AM tunnels (95.5 ± 9.9 vs 95.3 ± 8.4 mm², P = .96). There was no difference between the percentage of native footprint covered between TT and AM sockets (76.8% ± 7.8% vs 82.2% ± 13.7%, P = .47). Irrespective of drilling technique, there was significantly greater native ACL footprint covered by graft collagen when the bone plug was oriented with graft collagen inferior rather than posterior (75.6% ± 6.3% vs 65.4% ± 11.4%, P = .02).

CONCLUSION

Orienting the femoral bone plug such that the graft collagen is inferior rather than posterior significantly increases native ACL femoral footprint coverage in bone-patellar tendon-bone ACL reconstruction. This effect is consistent across AM and TT drilling techniques.

CLINICAL RELEVANCE

Surgeons attempting to restore an anatomic ACL footprint should consider bone plug-graft orientation when performing ACL reconstruction.

STUDY DESIGN

Controlled laboratory study.

Anterior Cruciate Ligament Reconstructions With Quadriceps Tendon Autograft Result in Lower Graft Rupture Rates but Similar Patient-Reported Outcomes as Compared With Hamstring Tendon Autograft: A Comparison of 875 Patients

BACKGROUND

Graft rupture is a devastating outcome after anterior cruciate ligament (ACL) reconstruction (ACLR). Little is known about graft rupture rates as well as clinical and functional outcomes after ACLR with quadriceps tendon (QT) autografts.

PURPOSE

To compare QT with hamstring tendon (HT) autografts in terms of the rates of graft and contralateral ACL rupture as well as patient-reported outcome measures.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

All primary ACLRs performed between 2010 and 2016 were followed prospectively for 24 months through the recording of graft ruptures and contralateral ACL injuries as well as patient-administered questionnaires.

RESULTS

A total of 875 patients were included in the study. Three factors-graft type, age group, and activity level-had a significant value in predicting the need for revision surgery. The odds of revision surgery were 5.5 times greater in children younger than 15 years than in adults older than 45 years, 3.6 times greater in patients with high activity levels than low activity levels, and 2.7 times greater in patients receiving an HT autograft as compared with a QT autograft. A significantly higher rate of ipsilateral graft ruptures versus contralateral ACL injuries was observed in the HT group (4.9% vs 2.3%; odds ratio, 2.1; P = .01) but not in the QT group (2.8% vs 2.3%). The difference in the ratios of graft and contralateral ACL ruptures was even more pronounced in highly active patients treated with HT autografts (11.1% vs 4.2%; odds ratio, 2.6; P = .01) as compared with QT autografts (5.0% vs 2.8%; P = .48). Two-year measures of Lysholm scores (mean ± SD: QT, 86.0 ± 22.3; HT, 89.4 ± 16.4) and Tegner activity scores (QT, 6.1 ± 2.0; HT, 5.7 ± 1.9) as well as visual analog scale pain (QT, 0.8 ± 1.3; HT, 0.7 ± 1.1) did not differ between grafts.

CONCLUSION

Graft choice does not influence clinical and functional outcomes 2 years after ACLR. However, 3 factors-graft type, age group, and activity level-have a significant value in predicting the need for revision surgery. Patients treated with HT autografts have a significantly higher, activity-dependent risk of revision surgery and experience more ipsilateral graft ruptures than subsequent contralateral ACL injuries when compared with patients treated with QT autografts. Young age and high activity level are significant predictors for ACL revision surgery.

Femoral Interference Screw Fixation in ACL Reconstruction Using Bone-Patellar Tendon-Bone Grafts

» Anterior cruciate ligament (ACL) reconstruction is a commonly performed orthopaedic procedure with numerous reconstructive graft and fixation options. Interference screws have become one of the most commonly utilized methods of securing ACL grafts such as bone-patellar tendon-bone (BPTB) autografts. » The composition of interference screws has undergone substantial evolution over the past several decades, and numerous advantages and disadvantages are associated with each design. » The composition, geometry, and insertional torque of interference screws have important implications for screw biomechanics and may ultimately influence the strength, stability of graft fixation, and biologic healing in ACL reconstruction. » This article reviews the development and biomechanical properties of interference screws while examining outcomes, complications, and gaps in knowledge that are associated with the use of femoral interference screws during BPTB ACL reconstruction.

Clinical Outcomes of Arthroscopic Primary Anterior Cruciate Ligament Repair: A Systematic Review from the Scientific Anterior Cruciate Ligament Network International Study Group

PURPOSE

To perform a systematic review of contemporary studies reporting clinical outcomes of primary anterior cruciate ligament (ACL) repair to determine whether these studies demonstrate any significant benefit of ACL repair and whether there is evidence of a deterioration of mid-term outcomes as seen in historical data.

METHODS

A systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. A PubMed search using the keywords "repair" AND "Anterior Cruciate Ligament" was performed (limits: English language, publication date between January 1, 2014, and January 13, 2019). All identified studies reporting clinical outcomes of arthroscopic ACL repair were included. Critical appraisal was conducted using the Cochrane Risk of Bias Tool for Randomized Clinical Trials and the Methodological Index for Non-Randomized Studies. Basic parameters of each study including population characteristics, repair technique, physical examination findings, and clinical outcome scores were recorded and evaluated.

RESULTS

Nineteen eligible studies were identified (including 5 comparative studies). None of the comparative studies showed any significant difference between repair and reconstruction groups with respect to International Knee Documentation Committee (IKDC), Lysholm, Tegner, side-to-side laxity difference, Lachman, pivot shift tests, or graft rupture rates. Four non-comparative studies reported outcomes at medium- to long-term follow up (range of mean follow up 43.3-79 months) with a mean Lysholm score between 85.3 and 100, mean IKDC subjective score between 87.3 and 100, and mean Tegner activity score between 5 and 7.

CONCLUSIONS

Comparative studies identified no significant differences between ACL repair and reconstruction with respect to Lysholm, IKDC, side-to-side laxity difference, pivot shift grade, or graft rupture rates. However, these studies had major limitations including small numbers and short durations of follow up. Case series demonstrated that excellent outcomes can be achieved at medium- to long-term follow up with the SAR technique.

LEVEL OF EVIDENCE

IV; Systematic review of Level II to IV investigations.

Over-the-top ACL reconstruction restores anterior and rotatory knee laxity in skeletally immature individuals and revision settings

PURPOSE

To investigate the objective outcomes following anterior cruciate ligament reconstruction (ACLR) with the over-the-top (OTT) technique.

METHODS

Thirty-five ACL-deficient patients with mean follow-up of 2.2 years were retrospectively reviewed. This included 14 skeletally immature individuals (age: 14 ± 1 years) who underwent primary OTT ACLR (adolescent group) and 21 skeletally mature individuals (age: 25 ± 8 years) who underwent OTT revision ACLR (revision group). The tibial tunnel was created at the anatomic position for all cases. No lateral extra-articular tenodesis was performed. Before and after surgery, the side-to-side difference (SSD) in anterior laxity was measured using KT-1000 arthrometer. Lachman and pivot-shift tests were assessed according to IKDC grade. The graft failure rate was assessed.

RESULTS

The post-operative SSD in anterior laxity was significantly reduced in the adolescent (pre-op, 3.9 ± 1.8 mm; post-op, 1.2 ± 0.8 mm; p = 0.040) and revision groups (pre-op, 4.2 ± 1.7 mm; post-op, 1.2 ± 1.4 mm; p < 0.001). Postoperative knee laxity measured by Lachman and pivot-shift tests were also significantly improved in both groups. Graft rupture occurred in two patients in the adolescent group (14.3%), and one patient in the revision group (4.8%).

CONCLUSION

ACLR with the OTT technique restored anterior and rotatory knee laxity in skeletally immature individuals and in revision settings. This one-step procedure may be a good option for skeletally immature individuals and revision settings.

LEVEL OF EVIDENCE

IV.

Anterior Cruciate Ligament Reconstruction in High School and College-Aged Athletes: Does Autograft Choice Influence Anterior Cruciate Ligament Revision Rates?

BACKGROUND

Physicians' and patients' decision-making process between bone-patellar tendon-bone (BTB) and hamstring tendon autografts for anterior cruciate ligament (ACL) reconstruction (ACLR) may be influenced by a variety of factors in the young, active athlete.

PURPOSE

To determine the incidence of both ACL graft revisions and contralateral ACL tears resulting in subsequent ACLR in a cohort of high school- and college-aged athletes who initially underwent primary ACLR with either a BTB or a hamstring autograft.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Study inclusion criteria were patients aged 14 to 22 years who were injured in sports, had a contralateral normal knee, and were scheduled to undergo unilateral primary ACLR with either a BTB or a hamstring autograft. All patients were prospectively followed for 6 years to determine whether any subsequent ACLR was performed in either knee after their initial ACLR. Multivariable regression modeling controlled for age, sex, ethnicity/race, body mass index, sport and competition level, baseline activity level, knee laxity, and graft type. The 6-year outcomes were the incidence of subsequent ACLR in either knee.

RESULTS

A total of 839 patients were eligible, of which 770 (92%) had 6-year follow-up for the primary outcome measure of the incidence of subsequent ACLR. The median age was 17 years, with 48% female, and the distribution of BTB and hamstring grafts was 492 (64%) and 278 (36%), respectively. The incidence of subsequent ACLR at 6 years was 9.2% in the ipsilateral knee, 11.2% in the contralateral normal knee, and 19.7% for either knee. High-grade preoperative knee laxity (odds ratio [OR], 2.4 [95% confidence interval [CI], 1.4-3.9]; P = .001), autograft type (OR, 2.1 [95% CI, 1.3-3.5]; P = .004), and age (OR, 0.8 [95% CI, 0.7-1.0]; P = .009) were the 3 most influential predictors of ACL graft revision in the ipsilateral knee. The odds of ACL graft revision were 2.1 times higher for patients receiving a hamstring autograft than patients receiving a BTB autograft (95% CI, 1.3-3.5; P = .004). No significant differences were found between autograft choices when looking at the incidence of subsequent ACLR in the contralateral knee.

CONCLUSION

There was a high incidence of both ACL graft revisions and contralateral normal ACL tears resulting in subsequent ACLR in this young athletic cohort. The incidence of ACL graft revision at 6 years after index surgery was 2.1 times higher with a hamstring autograft compared with a BTB autograft.

The Association Between Anterior Cruciate Ligament Length and Femoral Epicondylar Width Measured on Preoperative Magnetic Resonance Imaging or Radiograph

PURPOSE

To determine whether femoral epicondylar width (FECW) obtained from either magnetic resonance imaging (MRI) or plain radiographs could be used to predict anterior cruciate ligament (ACL) length. A secondary purpose was to develop a formula to use maximum FECW on either MRI or plain radiographs to estimate ACL length preoperatively.

METHODS

The MRIs and radiographs of 40 patients (mean age 41.0 years), with no apparent knee pathology, surgery, or trauma were included. The ACL length was measured on MRI followed by FECW on both MRI and radiograph of the same patient. This allowed the development of equations able to predict ACL length according to the FECW measured on either an MRI or radiograph.

RESULTS

The mean ACL length was 40.6 ± 3.6 mm. FECW measured on both MRIs and radiographs was sufficient to predict ACL length. Pearson's correlations revealed a high positive relationship between ACL length and FECW on MRI (r = 0.89, P < .0001) and ACL length and FECW on radiograph (r = 0.83, P < .0001). The coefficient of determination (R2) was calculated to be MRI: R2 = 0.78 and radiograph: R2 = 0.68 and confirmed that FECW measured on both MRI and radiograph were sufficient to predict ACL length. Based on these models, ACL length can be predicted by FECW using the following formulas: MRI: ACL length = 0.47 (FECW) + 1.93 and radiograph: ACL length = 0.31 (FECW) + 11.33.

CONCLUSIONS

This study demonstrated that FECW measured on either MRI or anteroposterior radiograph could reliably estimate ACL length on a sagittal MRI. There was a high positive relationship between ACL length and FECW on both MRI and radiographs, although MRIs do predict ACL length more reliably.

CLINICAL RELEVANCE

Preoperative ACL length assessment, using FECW on MRI or radiograph, is useful in graft selection and in preventing inadequate graft harvesting for ACL reconstruction, especially if an individualized anatomical approach is pursued.

Acute ACL reconstruction shows superior clinical results and can be performed safely without an increased risk of developing arthrofibrosis

PURPOSE

To compare acute ACL reconstruction (ACLR) within 8 days of injury with delayed reconstruction after normalized range of motion (ROM), 6-10 weeks after injury. It was hypothesized that acute ACL reconstruction with modern techniques is safe and can be beneficial in terms of patient-reported outcomes and range of motion.

METHODS

The effect of acute and delayed ACLR was randomized studied on 70 patients with high recreational activity level, Tegner level 6 or more, between 2006 and 2013. Patient-reported outcomes, objective IKDC, KOOS, and manual stability measurements were documented during the 24-month follow-up period.

RESULTS

The acute ACLR group did not result in increased stiffness and showed superior outcome regarding strength and how the patient felt their knee functioning at 24 months. In addition, the acute group was not inferior to the delayed group in any assessment. Regarding patient-related outcomes in KOOS, both groups showed significant improvements in all subscales, but no difference was found between the groups. Functional return (FR) rate was almost double compared to the Swedish knee ligament register and treatment failure (TF) rate was reduced by half, no significant difference between the groups. No difference regarding cyclops removal, re-injury of ACL or meniscus was found between the two surgical timing groups.

CONCLUSION

Acute ACLR within 8 days of injury does not appear to adversely affect ROM or result in increased stiffness in the knee joint and was not inferior to the delayed group in any assessment when compared to delayed surgery.

LEVEL OF EVIDENCE

I.

Anterior Cruciate Ligament Reconstruction in Young Female Athletes: Patellar Versus Hamstring Tendon Autografts

BACKGROUND

Female athletes are 2 to 8 times more prone to anterior cruciate ligament (ACL) rupture than males. Furthermore, reinjury to the ipsilateral or contralateral knee can occur in >20% of athletes. Female sex and younger age are known risk factors for graft failure. The optimal graft choice for young females remains unknown and poorly studied.

PURPOSE/HYPOTHESIS

The authors aimed to compare clinical outcomes in young females who underwent ACL reconstruction (ACLR) with bone-patellar tendon-bone (BTB) and quadrupled hamstring (HS) autografts. It was hypothesized that no significant differences in outcomes exist between graft choices.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Female patients aged 15 to 25 years who underwent primary ACLR with BTB or HS autograft were included for review. Patients were subdivided into 2 age groups: 15 to 20 years and 21 to 25 years. The occurrence of chondral, meniscal, or ligamentous injury to either knee was recorded for comparison.

RESULTS

A total of 256 females were included (BTB, n = 175; HS, n = 81). The majority of patients were between the ages of 15 and 20 years (BTB, 80%; HS, 77.8%). Overall, graft rupture occurred in 23 patients (9%) and contralateral ACL tear occurred in 18 (7%). Subgroup analysis showed that 75% of BTB and 100% of HS graft retears occurred in females aged 15 to 20 years. Within this age group, there was a significantly lower rate of graft ruptures in the BTB group (6.4%) as compared with the HS group (17.5%, P = .02). Allograft augmentation was used in 4 of the 11 HS grafts that retore. When allograft-augmented grafts were excluded, there was no significant difference in graft failure rate between graft choices. Fifteen patients in the BTB group (12%) as opposed to 1 in the HS group (2%) reported extreme difficulty or the inability to kneel on the front of the knee (P = .04).

CONCLUSION

In females aged 15 to 20 years undergoing ACLR, BTB autograft may lead to fewer graft ruptures than HS autograft. While this difference was not observed in females aged 21 to 25 years, a larger sample may be required to accept the null hypothesis in this age group. BTB autograft significantly increased the risk of kneeling pain as compared with HS regardless of age.