ACL reconstruction: patellar tendon versus hamstring grafts--economical aspects

Value-Based, Environmentally Sustainable Anterior Cruciate Ligament Surgery

Orthopedic surgeons are increasingly recognizing the broader societal impact of their clinical decisions, which includes value-based and environmentally sustainable care. Within anterior cruciate ligament reconstruction, value-based care-or most cost-effective care-includes an outpatient surgical setting with regional anesthesia, use of autograft, meniscus repair when indicated, and use of traditional metal implants such as interference screws and staples. Environmentally sustainable care includes slimming down surgical packs and trays to avoid opening unnecessary equipment, avoiding desflurane as an inhaled anesthetic agent, and minimizing waste in the operating room-a priority that addresses both cost and environmental impact.

Meniscus Work and Implant Selection Are Major Cost Drivers of Anterior Cruciate Ligament Reconstruction

Background The current study examines the financial charges associated with primary anterior cruciate ligament reconstruction (ACLR), specifically the contribution of graft choice, graft type, and concomitant meniscus surgery, in the outpatient hospital setting. Methods A retrospective financial billing review was performed on patients who underwent ACLR at a single academic medical center from January to December 2019. Age, BMI, insurance, length of operation, regional block, implants, meniscus surgery, graft type, and graft choice were extracted from hospital electronic patient records. Charges attributed with graft, anesthesia services, supplies, implants, surgeon fees, radiology charges, and total charges were collected. Total amount that insurance and patient paid were also obtained. Descriptive and quantitative statistics were performed. Results A total of 28 patients were studied (18 males, 10 females). The average age was 23.8 years. There were 20 concomitant meniscus surgeries. Six allografts and 22 autografts were used [eight bone-patellar tendon-bone (BPTB), eight hamstrings, six quadriceps]. The average and median total charge was $61,004 and $60,390, respectively (range: $31,403 to $97,914). The average insurance paid was $26,045 while out-of-pocket costs were $402. The average paid by private insurance was higher compared to government insurance ($31,111 vs. $11,066, p<0.001). Graft choice such as allograft vs. autograft (p=0.035) and meniscus surgery (p=0.048) were significant factors to the overall cost. Conclusions Graft choice, specifically the quadrupled hamstring autograft, and concomitant meniscal surgery are major contributors to variations in ACLR charges. Decreasing implant and graft costs and limiting surgical time can decrease charges associated with ACLR. We hope these findings can help guide surgeon financial decisions, by demonstrating the need to take into account the increased total charges and amount paid associated with specific grafts, meniscus surgery, and prolonged OR time.

Cost and Cost Driver Analysis of Anterior Cruciate Ligament Reconstruction Using Time-Driven Activity-Based Costing: Bone-Tendon-Bone Autograft Versus Hamstring Autograft

As health care transitions toward value-based care, orthopaedics has started to implement time-driven activity-based costing (TDABC) to understand costs and cost drivers. TDABC has not previously been used to study cost drivers in anterior cruciate ligament reconstruction (ACLR). The purpose of this study was to use TDABC to (1) calculate bone-tendon-bone (BTB) and hamstring ACLR total costs of care and (2) evaluate the impact of graft choice and other factors on ACLR costs.

Methods

Data were collected from electronic medical records for primary ACLR from the institutional patient-reported outcome registry between 2009 and 2016 in 1 ambulatory surgery center. Patients receiving allograft, revision ACLR, or concomitant meniscal repair or ligament reconstruction were excluded. The total cost of care was determined using TDABC. Multivariate regression analysis was conducted between ACLR cost and group characteristics.

Results

A total of 328 patients were included; 211 (64.3%) received BTB autograft and 117 (35.7%) received hamstring autograft. The mean cost was $2,865.01 ± $263.45 (95% confidence interval: $2,829.26, $2,900.77) for BTB ACLR versus $3,377.44 ± $320.12 ($3,318.82, $3,436.05) for hamstring ACLR (p < 0.001). Operative time was 103.1 ± 25.1 (99.7, 106.5) minutes for BTB ACLR versus 113.1 ± 27.9 (108.0, 118.2) minutes for hamstring ACLR (p = 0.001). The total implant cost was $270.32 ± $97.08 ($257.15, $283.50) for BTB ACLR versus $587.36 ± $108.78 ($567.44, $607.28) for hamstring ACLR (p < 0.001). Hamstring graft (p = 0.006) and suspensory fixation on the femoral side (p = 0.011) were associated with increased costs.

Conclusions

The mean cost of care and operative time for BTB autograft ACLR are less than those for hamstring autograft ACLR. Operative time, implant choice, and graft choice were identified as modifiable cost drivers that can empower surgeons to manage primary ACLR costs while maximizing the value of the procedure.

Level of Evidence

Economic and Decision Analysis Level IV. See Instructions for Authors for a complete description of levels of evidence.

Health Economic Evaluations of Hip and Knee Interventions in Orthopaedic Sports Medicine: A Systematic Review and Quality Assessment

BACKGROUND

The economic burden of musculoskeletal diseases is substantial and growing. Economic evaluations compare costs and health benefits of interventions simultaneously to help inform value-based care; thus, it is crucial to ensure that studies are using appropriate methodology to provide valid evidence on the cost-effectiveness of interventions. This is particularly the case in orthopaedic sports medicine, where several interventions of varying costs are available to treat common hip and knee conditions.

PURPOSE

To summarize and evaluate the quality of economic evaluations in orthopaedic sports medicine for knee and hip interventions and identify areas for quality improvement.

STUDY DESIGN

Systematic review; Level of evidence, 3.

METHODS

The Medline, AMED, OVID Health Star, and EMBASE databases were searched from inception to March 1, 2020, to identify economic evaluations that compared ≥2 interventions for hip and/or knee conditions in orthopaedic sports medicine. We assessed the quality of full economic evaluations using the Quality of Health Economic Studies (QHES) tool, which consists of 16 questions for a total score of 100. We classified studies into quartiles based on QHES score (extremely poor quality to high quality) and we evaluated the frequency of studies that addressed each of the 16 QHES questions.

RESULTS

A total of 93 studies were included in the systematic review. There were 41 (44%) cost analyses, of which 21 (51%) inappropriately concluded interventions were cost-effective. Only 52 (56%) of the included studies were full economic evaluations, although 40 of these (77%) fell in the high-quality quartile. The mean QHES score was 83.2 ± 19. Authors consistently addressed 12 of the QHES questions; questions that were missed or unclear were related to statistical uncertainty, appropriateness of costing methodology, and discussion of potential biases. The most frequently missed question was whether the cost perspective of the analysis was stated and justified.

CONCLUSION

The number of studies in orthopaedic sports medicine is small, despite their overall good quality. Yet, there are still many highly cited studies based on low-quality or partial economic evaluations that are being used to influence clinical decision-making. Investigators should follow international health economic guidelines for study design and critical appraisal of studies to further improve quality.

Safety of the application of Rigidfix cross-pin system via different tibial tunnels for tibial fixation during anterior cruciate ligament reconstruction

BACKGROUND

We investigate the safety of the application of the Rigidfix cross-pin system via different tibial tunnels in the tibial fixation during anterior cruciate ligament (ACL) reconstruction.

METHODS

Five adult fresh cadaver knees were fixed with the Rigidfix cross-pins in the tibial fixation site during ACL reconstruction. Two different tibial tunnel groups were established: in group A, the tunnel external aperture was placed at the 25° angle of coronal section; in group B, the tunnel external aperture was placed at the 45° angle of coronal section. The guide was placed at the plane 0.5 mm below articular facet through the tibial tunnel, with three rotation positions set at 0°, 30°, and 60° slopes. The incidences of iatrogenic injuries at tibial plateau cartilage (TPC), medial collateral ligament (MCL), and patellar tendon in three different slope angles were calculated in groups A and B and the results were analyzed by using chi square test.

RESULTS

The iatrogenic injuries at MCL, TPC, and patellar tendon could occur after the Rigidfix cross-pin system was placed 5 mm below tibial plateau cartilage for ACL reconstruction. The incidences of TPC injury (χ² = 5.662, P = 0.017) and MCL injury (P = 0.048, Fisher exact probability method) were significantly lower in group A than in group B. However, the incidence of patellar tendon injury showed no significant difference between these two groups (χ² = 0.120, P = 0.729).

CONCLUSIONS

When the Rigidfix cross-pin system is used for ACL reconstruction at the tibial fixation site, the external aperture of tibial tunnel should not be placed at the excessively posterosuperior site, to avoid MCL and TPC injuries.

The anatomical and imaging study of pes anserinus and its clinical application

BACKGROUND

The pes anserinus was an important graft choice for anterior cruciate ligament (ACL) reconstruction. The infrapatellar branch of the saphenous nerve (IPBSN) might be damaged in this surgery. This study aimed to provide anatomic and ultrasonic measurement data of pes anserinus and superficial nerves.

METHODS

Eighty lower limb specimens of forty adult cadavers were dissected. The length, width, thickness, and the position of the tibial attachment of pes anserinus tendons were anthropometric measured, as well as the distance between the infrapatellar branch of the saphenous nerve and the pes anserinus. Sixty healthy adult participants were enrolled for ultrasonic research. The length, width, thickness of pes anserinus was also measured and the saphenous nerve was also assessed.

RESULTS

Anatomic results showed that there were 3 types of pes anserinus, the infrapatellar branch of the saphenous nerve (IPBSN) was almost paralleled to the upper edge of the pes anserinus tendon, and the average of distance between them was about 0.95 cm. The length of semitendinosus and gracilis tendons were 146.49 ± 12.83 mm and 124.62 ± 8.86 mm, the width of sartorius tendon was 25.58 ± 4.65 mm, wider than other tendons. The classification of pes anserinus tendons and the saphenous nerves could be identified in ultrasonic image. The length of semitendinosus and gracilis tendons were 151.35 ± 9.65 mm and 120.86 ± 8.99 mm, the width of sartorius tendon was 22.84 ± 3.83 mm. And there was no significance difference between anatomic and ultrasonic measurement (P > .05).

CONCLUSION

The morphology of pes anserinus and its peripheral structures could be identified and measured precisely by ultrasound device, a presurgical ultrasonic examination was recommended. The arrangement of pes anserinus tendons was classified into 3 types according to our results. The incision should be performed medial to tibial eminence 1.5 cm and under the tibial tubercle level 2 to 3 cm, an oblique incision formed an angle of 50° with tibial transection was recommend, which was parallel to the direction of pes anserinus tendon.

Similar cost-utility for double- and single-bundle techniques in ACL reconstruction

PURPOSE

The aim was to estimate the cost-utility of the DB technique (n = 53) compared with the SB (n = 50) technique 2 years after ACL reconstruction.

METHODS

One hundred and five patients with an ACL injury were randomised to either the Double-bundle (DB) or the Single-bundle (SB) technique. One hundred and three patients (SBG n = 50, DBG n = 53) attended the 2-year follow-up examination. The mean age was 27.5 (8.4) years in the SBG and 30.1 (9.1) years in the DBG. The cost per quality-adjusted life years (QALYs) was used as the primary outcome. Direct costs were the cost of health care, in this case outpatient procedures. Indirect costs are costs related to reduce work ability for health reasons. The cost-utility analysis was measured in terms of QALY gained.

RESULTS

The groups were comparable in terms of clinical outcome. Operating room time was statistically significantly longer in the DBG (p = 0.001), making the direct costs statistically significantly higher in the DBG (p = 0.005). There was no significant difference in QALYs between groups. In the cost-effectiveness plane, the mean difference in costs and QALYs from the trial data using 1000 bootstrap replicates in order to visualise the uncertainty associated with the mean incremental cost-effectiveness ratio (ICER) estimate showed that the ICERs were spread out over all quadrants. The cost-effectiveness acceptability curve showed that there was a 50% probability of the DB being cost-effective at a threshold of Euro 50,000.

CONCLUSION

The principal findings are that the DB is more expensive from a health-care perspective. This suggests that the physician may choose individualised treatment to match the patients' expectations and requirements.

Economic Analyses in Anterior Cruciate Ligament Reconstruction: A Qualitative and Systematic Review

BACKGROUND

As the health care system in the United States (US) transitions toward value-based care, there is an increased emphasis on understanding the cost drivers and high-value procedures within orthopaedics. To date, there has been no systematic review of the economic literature on anterior cruciate ligament reconstruction (ACLR).

PURPOSE

To evaluate the overall evidence base for economic studies published on ACLR in the orthopaedic literature. Data available on the economics of ACLR are summarized and cost drivers associated with the procedure are identified.

STUDY DESIGN

Systematic review.

METHODS

All economic studies (including US-based and non-US-based) published between inception of the MEDLINE database and October 3, 2014, were identified. Given the heterogeneity of the existing evidence base, a qualitative, descriptive approach was used to assess the collective results from the economic studies on ACLR. When applicable, comparisons were made for the following cost-related variables associated with the procedure for economic implications: outpatient versus inpatient surgery (or outpatient vs overnight hospital stay vs >1-night stay); bone-patellar tendon-bone (BPTB) graft versus hamstring (HS) graft source; autograft versus allograft source; staged unilateral ACLR versus bilateral ACLR in a single setting; single- versus double-bundle technique; ACLR versus nonoperative treatment; and other unique comparisons reported in single studies, including computer-assisted navigation surgery (CANS) versus traditional surgery, early versus delayed ACLR, single- versus double-incision technique, and finally the costs of ACLR without comparison of variables.

RESULTS

A total of 24 studies were identified and included; of these, 17 included studies were cost identification studies. The remaining 7 studies were cost utility analyses that used economic models to investigate the effect of variables such as the cost of allograft tissue, fixation devices, and physical therapy, the percentage and timing of revision surgery, and the cost of revision surgery. Of the 24 studies, there were 3 studies with level 1 evidence, 8 with level 2 evidence, 6 with level 3 evidence, and 7 with level 4 evidence. The following economic comparisons were demonstrated: (1) ACLR is more cost-effective than nonoperative treatment with rehabilitation only (per 3 cost utility analyses); (2) autograft use had lower total costs than allograft use, with operating room supply costs and allograft costs most significant (per 5 cost identification studies and 1 cost utility analysis); (3) results on hamstring versus BPTB graft source are conflicting (per 2 cost identification studies); (4) there is significant cost reduction with an outpatient versus inpatient setting (per 5 studies using cost identification analyses); (5) bilateral ACLR is more cost efficient than 2 unilateral ACLRs in separate settings (per 2 cost identification studies); (6) there are lower costs with similarly successful outcomes between single- and double-bundle technique (per 3 cost identification studies and 2 cost utility analyses).

CONCLUSION

Results from this review suggest that early single-bundle, single (endoscopic)-incision outpatient ACLR using either BPTB or HS autograft provides the most value. In the setting of bilateral ACL rupture, single-setting bilateral ACLR is more cost-effective than staged unilateral ACLR. Procedures using CANS technology do not yet yield results that are superior to the results of a standard surgical procedure, and CANS has substantially greater costs.

Health-related quality of life and direct costs in patients with anterior cruciate ligament injury: single-bundle versus double-bundle reconstruction in a low-demand cohort--a randomized trial with 2 years of follow-up

PURPOSE

To evaluate health-related quality of life (HRQL) in patients undergoing anterior cruciate ligament (ACL) reconstructive surgery by use of 2 procedures and to estimate the direct costs of surgery.

METHODS

We performed a 2-year randomized, prospective intervention study of 2 surgical ACL reconstruction techniques (anatomic single bundle [SB] v double bundle [DB]). Fifty-five consecutive outpatients, with a mean age of 30.88 years, were randomized to SB or DB ACL reconstruction. The Medical Outcomes Study 36-item Short Form Health Survey (SF-36) was used to measure HRQL (primary outcome). ACL injuries were assessed by the International Knee Documentation Committee (IKDC) score (secondary outcome). The use of medical resources and their costs were evaluated.

RESULTS

We included 52 patients in the final analyses (23 in the SB group and 29 in the DB group). At baseline, there were no significant differences in study variables. At 2 years of follow-up, there were no significant differences in SF-36 and IKDC scores between groups. However, compared with baseline, the SF-36 physical function, physical role, bodily pain, social function, and emotional role scores were significantly better in the SB group (P < .05), whereas only the physical function dimension score was better in the DB group (P = .047). IKDC scores at 2 years improved significantly in the SB group (P < .001) and DB group (P = .004) compared with baseline. There was a significant correlation between the SF-36 physical function, physical role, and bodily pain dimensions and the IKDC score at 2 years (P < .05). The costs were € 3,251 for the SB group and € 4,172 for the DB group.

CONCLUSIONS

HRQL and medical outcomes were similar between SB and DB ACL reconstruction techniques, 2 years after surgery. However, the SB technique was more cost-effective.

Femoral press-fit fixation in ACL reconstruction using bone-patellar tendon-bone autograft: results at 15 years follow-up

Background

If anterior cruciate ligament (ACL) reconstruction is to be performed, decision regarding graft choice and its fixation remains one of the most controversial. Multiple techniques for ACL reconstruction are available. To avoid disadvantages related to fixation devices, a hardware-free, press-fit ACL reconstruction technique was developed.

The aim of this study was to evaluate clinical outcome and osteoarthritis progression in long term after ACL reconstruction with central third patellar-tendon autograft fixed to femur by press-fit technique.

Methods

Fifty two patients met inclusion/excusion criteria for this study. The patients were assessed preoperatively and at 15 years after surgery with International Knee Documentation Committee Knee Ligament Evaluation Form, Lysholm knee score, Tegner activity scale and radiographs.

Results

Good overall clinical outcomes and self-reported assessments were documented, and remained good at 15 years. The mean Lysholm and Tegner scores improved from 59.7 ± 18.5 and 4.2 ± 1.0 preoperatively to 86.4 ± 5.6 (p = 0.004) and 6.9 ± 1.4 (p = 0.005) respectively at follow-up. The IKDC subjective score improved from 60.1 ± 9.2 to 80.2 ± 8.1 (p = 0.003).

According to IKDC objective score, 75% of patients had normal or nearly normal knee joints at follow-up. Grade 0 or 1 results were seen in 85% of patients on laxity testing. Degenerative changes were found in 67% of patients. There was no correlation between arthritic changes and stability of knee and subjective evaluation (p > 0.05).

Conclusions

ACL reconstruction with patellar tendon autograft fixed to femur with press-fit technique allows to achieve good self-reported assessments and clinical ligament evaluation up to 15 years. Advantages of the bone-patellar-tendon-bone (BPTB) press-fit fixation include unlimited bone-to-bone healing, cost effectiveness, avoidance of disadvantages associated with hardware, and ease for revision surgery. BPTB femoral press-fit fixation technique can be safely applied in clinical practice and enables patients to return to preinjury activities including high-risk sports.

Comparação entre parafuso de interferência e transcondilar na reconstrução do LCA

OBJETIVO: A fixação femoral na reconstrução do Ligamento Cruzado Anterior (LCA) com enxerto de tendões flexores pode variar muito de acordo com a disposição dos materiais e a experiência do cirurgião. Porém os trabalhos que comparam os sistemas de fixação são efetuados na maioria das vezes em cadáveres ou em animais, sem avaliar os resultados clínicos, prejudicando sua comparação com pacientes humanos vivos. Neste artigo avaliamos o resultado clínico de dois métodos de fixação do enxerto ao fêmur (parafuso de interferência de titânio e parafuso transcondilar de titânio) para saber se, do ponto de vista clinico e subjetivo, há diferença entre estes métodos. MÉTODOS: Foram selecionados 40 pacientes com lesão do LCA sendo que 20 pacientes tiveram seu enxerto fixado ao fêmur com parafuso de interferência e 20 com parafuso transcondilar. Todos foram reavaliados com no mínimo dois anos de pós operatório para medição da gaveta anterior, Pivot Shift e teste de Lachman, além da obtenção dos questionário de Lysholm e IKDC (International Knee Documentation Committee). RESULTADOS: Os resultados não foram estatisticamente diferentes para os critérios avaliados. CONCLUSÃO: As duas formas de fixação são eficientes para esta técnica dentro dos parâmetros estabelecidos. Nível de Evidência II, Estudo Prospectivo Comparativo.

A comparison of the quasi-static mechanical and non-linear viscoelastic properties of the human semitendinosus and gracilis tendons

BACKGROUND

Over 50-% of anterior cruciate ligament reconstructions are performed using semitendinosus and gracilis tendon autografts. Despite their increased use, there remains little quantitative data on their mechanical behavior. Therefore, the objective of this study was to investigate the quasi-static mechanical and non-linear viscoelastic properties of human semitendinosus and gracilis tendons, as well as the variation of these properties along their length.

METHODS

Specimens were subjected to a series of uniaxial tensile tests: 1-h static stress-relaxation test, 30 cycle cyclic stress-relaxation test and load to failure test. To describe the non-linear viscoelastic behavior, the quasi-linear viscoelastic theory was utilized to model data from the static stress-relaxation experiment.

FINDINGS

The constants describing the viscoelastic behavior were similar between the proximal and distal halves of the gracilis tendon. The proximal half of the semitendinosus tendon, however, had a greater viscous response than its distal half, which was also significantly higher than the proximal gracilis tendon. In terms of the quasi-static mechanical properties, the properties were similar between the proximal and distal halves of the semitendinosus tendon. However, the distal gracilis tendon showed a significantly higher tangent modulus and ultimate stress compared to its proximal half, which was also significantly higher than the distal semitendinosus tendon.

INTERPRETATION

The results of this study demonstrate differences between the semitendinosus and gracilis tendons in terms of their quasi-static mechanical and non-linear viscoelastic properties. These results are important for establishing surgical preconditioning protocols and graft selection.

Atividade eletromiográfica dos músculos do joelho em indivíduos com reconstrução do ligamento cruzado anterior sob diferentes estímulos sensório-motores: relato de casos

O objetivo deste foi descrever a atividade eletromiográfica dos músculos estabilizadores do joelho de indivíduos que receberam diferentes enxertos na cirurgia de reconstrução do ligamento cruzado anterior (LCA). Foram avaliados dois casos de enxerto patelar, dois de enxerto posterior e dois controle, durante seis estímulos proprioceptivos ao indivíduo em apoio unipodal (em solo, prancha inclinada, prancha redonda, balancinho e rollerboard em sentido ântero-posterior, AP, e médio-lateral, ML). O sinal eletromiográfico normalizado foi captado durante contração isométrica voluntária máxima (CIVM) de cada músculo (vasto medial oblíquo, vasto lateral, semitendinoso, bíceps femoral e gastrocnêmio). Ao comparar os músculos vasto medial oblíquo e vasto lateral entre os casos, foi encontrada porcentagem da CIVM maior na amostra com enxerto patelar durante os estímulos solo, prancha inclinada e rollerboard AP, enquanto nos casos de enxerto posterior isso ocorreu sob os estímulos de balancinho e prancha redonda. Ao analisar somente os músculos flexores, os sujeitos com enxerto posterior apresentaram maior atividade sob os estímulos de balancinho e rollerboard ML. Conclui-se que os casos com enxerto patelar ativam mais sua musculatura que aqueles com enxerto posterior; e a quantidade de ativação muscular parece variar para cada estímulo sensório-motor, conforme o tipo de enxerto usado. Estes achados podem orientar a reabilitação de indivíduos submetidos à cirurgia de reconstrução do LCA.

[Posterior femoral cortex perforation unrecognised during arthroscopic LCA reconstructive surgery]

One of the most important technical demands in ACL surgery is good fixation of the graft. Integrity of the posterior femoral cortex is necessary for Interference screws fixation. The femoral tunnel, placed as posterior as possible, is also mandatory for good graft position and potentially leads to violation of the cortex. The divergence between screw and tunnel could result in perforation of the posterior wall. Without intraoperative x-ray it is difficult to be sure that position of the screw is correct, even with good graft tension. Still, the problem exists with absorbable screws. The aim of the study is to show results of 6 patients with this complication treated without revision of the femoral fixation with mean follow up of 1.5 year. Potential pitfall in ACL reconstruction is posterior cortex breakout and loss of fixation. If it is recognized during surgery changing the type of fixation can solve the problem, but if not, in the early phase of rehabilitation and weight bear, graft failure is feasible. The tibia tunnel angle and length, the footprint of femoral tunnel reamer and hyper flexion of the knee during screw insertion are methods for preventing the breakout of the posterior wall and screw-tunnel divergence. Modification of the early postoperative treatment and less aggressive rehabilitation protocol reduced the need for revision surgery. Even with best surgical technique, skill and experience this complication is possible to occur.

Biomechanics and anterior cruciate ligament reconstruction

For years, bioengineers and orthopaedic surgeons have applied the principles of mechanics to gain valuable information about the complex function of the anterior cruciate ligament (ACL). The results of these investigations have provided scientific data for surgeons to improve methods of ACL reconstruction and postoperative rehabilitation. This review paper will present specific examples of how the field of biomechanics has impacted the evolution of ACL research. The anatomy and biomechanics of the ACL as well as the discovery of new tools in ACL-related biomechanical study are first introduced. Some important factors affecting the surgical outcome of ACL reconstruction, including graft selection, tunnel placement, initial graft tension, graft fixation, graft tunnel motion and healing, are then discussed. The scientific basis for the new surgical procedure, i.e., anatomic double bundle ACL reconstruction, designed to regain rotatory stability of the knee, is presented. To conclude, the future role of biomechanics in gaining valuable in-vivo data that can further advance the understanding of the ACL and ACL graft function in order to improve the patient outcome following ACL reconstruction is suggested.