Increased risk for early revision with quadriceps graft compared with patellar tendon graft in primary ACL reconstructions.

PURPOSE: Bone patella-tendon bone (BPTB) and hamstring tendon (HT) autografts are the most used grafts in primary anterior cruciate ligament (ACL) reconstructions (ACLR) in Norway. Quadriceps tendon (QT) autograft has gained more popularity during the past years. The purpose of this study is to compare revision rates and patient-reported outcomes of primary QT with BPTB and HT autograft ACL reconstructions in Norway at 2-year follow-up. It was hypothesized that there would be no difference in 2-year revision rates between all three autografts. METHODS: Data included primary ACLR without concomitant ligament surgeries, registered in the Norwegian Knee Ligament Register from 2004 through 2021. Revision rates at 2 years were calculated using Kaplan-Meier analysis. Hazard ratios (HR) for revision were estimated using multivariable Cox regression analysis with revision within 2 years as endpoint. Mean change in patient-reported outcome was recorded preoperatively and at 2 years through the Knee Injury and Osteoarthritis Outcome Score (KOOS) subcategories 'Sport' and 'Quality of Life' was measured for patients that were not revised and analysed with multiple linear regression. RESULTS: A total of 24,790 primary ACLRs were identified, 10,924 with BPTB, 13,263 with HT and 603 with a QT graft. Patients in the QT group were younger (23.5 years), more of them were women (58.2%) and over 50% had surgery <3 months after injury. The QT group had the highest prevalence of meniscal injuries (61.9%). Revision estimates at 2-years were 3.6%, 2.5% and 1.2% for QT, HT and BPTB, respectively (p < 0.001). In a Cox regression analysis with QT as reference, BPTB had a lower risk of revision (HR 0.4, 95% Cl 0.2-0.7, p < 0.001). No significant difference was observed in the revision risk between QT and HT (HR 1.1, 95% Cl 0.7-1.8, n.s.). The two most common reported reasons for revision were: traumatic graft rupture and nontraumatic graft failure. There were no differences between the groups in change of KOOS in subcategories 'Sport' and 'Quality of Life' at 2-years follow-up. CONCLUSION: The 2-year risk of revision after ACLR with QT was higher than BPTB and similar to HT. No difference was found between the groups in patient-reported outcomes. This study provides valuable insights for both surgeons and patients when making decisions about the choice of autografts in primary ACL reconstructions. LEVEL OF EVIDENCE: Level II.

The impact of bone graft type used to fill bone defects in patients undergoing ACL reconstruction with bone-patellar tendon-bone (BPTB) autograft on kneeling, anterior knee pain and knee functional outcomes.

PURPOSE: Multiple different materials are used for filling bone defects following bone-patellar tendon-bone (BPTB) graft ACL reconstruction surgery. The theoretical objective being to minimize kneeling pain, improve clinical outcomes and reduce anterior knee pain following surgery. The impact of these materials is assessed in this study. METHODS: A prospective monocentric cohort study was conducted from January 2018 to March 2020. There were 128 skeletally mature athletic patients who underwent ACL reconstruction using the same arthroscopic-assisted BPTB technique, with a minimum follow-up of two years identified in our database. After obtaining approval from the local ethics committee, 102 patients were included in the study. Patients were divided into three groups based on type of bone substitute. The Bioactive glass 45S5 ceramic Glassbone™ (GB), collagen and hydroxyapatite bone void filler in sponge form Collapat® II (CP), and treated human bone graft Osteopure®(OP) bone substitutes were used according to availability. Clinical evaluation of patients at follow-up was performed using the WebSurvey software. A questionnaire completed in the 2nd post-operative year included three items: The ability to kneel, the presence of donor site pain, and the palpation of a defect. Another assessment tool included the IKDC subjective score and Lysholm score. These two tools were completed by patients preoperatively, and postoperatively on three occasions (6 months, 1 year, and 2 years). RESULTS: A total of 102 patients were included in this study. In terms of Kneeling pain, the percentage of GB and CP patients' who kneel with ease were much higher than that of OP patients (77.78%, 76.5% vs 65.6%, respectively). All three groups experienced an important increase in IKDC and Lysholm scores. There was no difference in anterior knee pain between the groups. CONCLUSION: The use of Glassbone® and Collapat II® bone substitutes reduced the incidence of kneeling pain compared to Osteopure®. There was no influence of the bone substitute type on the functional outcome of the knee or on the anterior knee pain at two years of follow.

Randomized Controlled Trials Comparing Bone-Patellar Tendon-Bone Versus Hamstring Tendon Autografts in Anterior Cruciate Ligament Reconstruction Surgery Are Statistically Fragile: A Systematic Review.

PURPOSE: To assess the statistical fragility of recently published randomized controlled trials (RCTs) comparing the use of hamstring tendon autograft with bone-patellar tendon-bone autograft for anterior cruciate ligament (ACL) reconstruction. METHODS: The PubMed, Embase, and MEDLINE databases were queried for RCTs published since 2010 comparing autograft type (bone-patellar tendon-bone vs hamstring tendon) in ACL reconstruction surgery. The fragility index (FI) and reverse FI (rFI) were determined for significant and nonsignificant outcomes, respectively, as the number of outcome reversals required to change statistical significance. The fragility quotient (FQ) and reverse FQ, representing fragility as a proportion of the study population, were calculated by dividing the FI and rFI, respectively, by the sample size. RESULTS: We identified 19 RCTs reporting 55 total dichotomous outcomes. The median FI of the 55 total outcomes was 5 (interquartile range [IQR], 4-7), meaning a median of 5 outcome event reversals would alter the outcomes' significance. Five outcomes were reported as statistically significant with a median FI of 4 (IQR, 2-6), meaning a median of 4 outcome event reversals would change outcomes to be nonsignificant. Fifty outcomes were reported as nonsignificant with a median rFI of 5 (IQR, 4-7), meaning a median of 5 outcome event reversals would change outcomes to be significant. The FQ and reverse FQ for significant and nonsignificant outcomes were 0.025 (IQR, 0.018-0.045) and 0.082 (IQR, 0.041-0.106), respectively. For 61.8% of outcomes, patients lost to follow-up exceeded the corresponding FI or rFI. CONCLUSIONS: There is substantial statistical fragility in recent RCTs on autograft choice in ACL reconstruction surgery given that altering a few outcome events is sufficient to reverse study findings. For over half of outcomes, maintaining patients lost to follow-up may have been sufficient to reverse study conclusions. CLINICAL RELEVANCE: We recommend co-reporting FIs and P values to provide a more comprehensive representation of a study's conclusions when conducting an RCT.

Editorial Commentary: Quadriceps Tendon Anterior Cruciate Ligament Graft Shows Advantages and Disadvantages.

A quadriceps tendon autograft is becoming an increasingly popular graft option for both primary and revision ACL reconstruction. The biomechanical properties of a QT autograft are favorable compared to a bone-patellar tendon-bone (BPTB) or a doubled hamstring (HS) autograft. A QT autograft is associated with less donor site morbidity, such as anterior knee pain and difficulty with kneeling, than a BPTB autograft, and short-term studies have shown comparable clinical results when compared to a BPTB or a HS autograft. However, if harvested with a bone block, a QT autograft carries a higher risk of patellar fracture than a BPTB autograft. Other potential disadvantages include persistent quadriceps weakness, and registry data have shown a higher revision rate compared to a BPTB or HS ACL reconstruction, which is thought to be due to a high learning curve, leading to higher revision rates in low volume centers. Finally, a graft-fixation construct with good time 0 biomechanical characteristics may only be successful in the long term if the graft heals effectively. Time will tell.

Time to treat the tendon rupture induced by surgery: early hypertrophy of the patellar tendon graft site predicts strong quadriceps after ACLR with bone-patellar tendon-bone autograft.

PURPOSE: Quadriceps dysfunction is ubiquitous after anterior cruciate ligament reconstruction, especially when using bone-patellar tendon-bone (BPTB) autografts. The role of patellar tendon hypertrophy after graft harvest on knee extensor strength is unknown. The purpose of this study was to determine the predictive ability of patellar tendon (PT) and quadriceps muscle (Quad) cross-sectional area (CSA) on knee extensor strength 1-2 months after ACLR using BPTB autografts. METHODS: This is a cross-sectional analysis of a cohort 1-2 months after ACLR using BPTB autograft. Peak knee extensor torque, and PT and Quad CSA measured using ultrasound imaging, were collected in 13 males and 14 females. Simple linear regressions compared quadriceps strength index (QI) against limb symmetry index (LSI) in PT and Quad CSA. Multiple linear regressions with sequential model comparisons predicting peak knee extensor torque were performed for each limb. The base model included demographics. Quad CSA was added in the first model, then PT CSA was added in the second model. RESULTS: Both PT (p < 0.001, R2 = 0.693) and Quadriceps CSA (p = 0.013, R2 = 0.223) LSI had a positive linear relationship with QI. In the involved limb, addition of PT CSA significantly improved the model (R2 = 0.781, ΔR2 = 0.211, p for ΔR2 < 0.001). In the uninvolved limb, the addition of Quad CSA improved the model, but the addition of PT CSA did not. CONCLUSION: PT LSI was more predictive of QI than Quad CSA LSI. Involved limb PT CSA mattered more in predicting peak knee extensor torque than did Quad CSA, but in the uninvolved limb, Quad CSA was the most important predictor of peak knee extensor torque. Graft site patellar tendon hypertrophy is key for strong quadriceps early after ACLR. Early targeted loading via exercise to promote healing of the graft site patellar tendon may bring patients a step closer to winning their battle against quadriceps dysfunction. LEVEL OF EVIDENCE: Level I.

Quadriceps tendon autograft has similar clinical outcomes when compared to hamstring tendon and bone-patellar tendon-bone autografts for revision ACL reconstruction: a systematic review and meta-analysis.

PURPOSE: Research regarding revision anterior cruciate ligament reconstruction (RACLR) with quadriceps tendon (QT) autografts is lacking. The purpose of this study was to perform a systematic review and meta-analysis of RACLR with QT and compare its patient outcomes to RACLR with hamstring tendon (HT) and bone-patellar tendon-bone (BTB) autografts. METHODS: Adhering to PRISMA guidelines, a search for studies using QT in RACLR was performed within PubMed, Scopus, and CINAHL from database date of inception through December 26, 2022. Primary outcomes sought included: failure rate, Lysholm scores, International Knee Documentation Committee (IKDC) scores, IKDC grades, arthrometric knee side-to-side differences (STSD), pivot shift grade, donor site morbidity, return to sport, visual analog scale (VAS) pain scores. RESULTS: Nine studies were included consisting of 606 RACLR: 349 QT, 169 HT, and 88 BTB. Overall failure rates were 7.6% QT, 13.3% HT, and 8.7% BTB. Mean weighted Lysholm scores were 85.8 ± 3.8 QT, 82.5 ± 3.8 HT and 86.6 ± 4.5 BTB. IKDC average scores were 82.3 ± 1.6 QT, 80.1 ± 1.7 HT, and 81.7 ± 5.5BTB. Combined rates of IKDC A/B grades were 88.4% and 80.0% for QT and HT, respectively. VAS average scores were 0.9 ± 1.1 QT, 1.4 ± 0.2 HT, and 0.7 ± 0.8 for BTB. Side-to-side difference was reported for QT and HT with average values of 1.7 ± 0.6 mm and 2.1 ± 0.5 mm, respectively. Grade 0 or 1 pivot shifts were reported in 96.2% of QT patients and 91.3% of HT. Donor site morbidity, only reported for QT and HT, was 14.6 ± 9.7% and 23.6 ± 14.1%, respectively. QT resulted in a mean Tegner score of 5.9 ± 1.5 versus HT 5.7 ± 1.5. Rate of return to pivoting sports was 38.0% QT, 48.6% HT, and 76.9% BTB. Across all outcomes, there was no significant difference when comparing QT to HT, QT to BTB, and QT compared to HT and BTB combined. CONCLUSIONS: RACLR with QT yields satisfactory patient reported outcomes, satisfactory improvement in knee laxity, expected return to sport rates, and has an overall 7.6% failure rate. Outcomes are comparative to those of HT and BTB making it an acceptable graft choice for RACLR. Surgeons should consider using QT autograft for RACLR, especially when other autografts are unavailable. LEVEL OF EVIDENCE: IV.

Comparison of Knee Pain and Difficulty With Kneeling Between Patellar Tendon and Hamstring Tendon Autografts After Anterior Cruciate Ligament Reconstruction: A Study From the New Zealand ACL Registry.

BACKGROUND: The bone-patellar tendon-bone (BTB) autograft is associated with difficulty with kneeling after anterior cruciate ligament (ACL) reconstruction; however, it is unclear whether it results in a more painful or symptomatic knee compared with the hamstring tendon autograft. PURPOSE: To identify the rate and risk factors for knee pain and difficulty with kneeling after ACL reconstruction. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Primary ACL reconstruction procedures prospectively recorded in the New Zealand ACL Registry from April 2014 to May 2021 were analyzed. The Knee injury and Osteoarthritis Outcome Score (KOOS) was used to identify patients reporting consequential knee pain (CKP), defined as a KOOS Pain subscore of ≤72 points, and severe kneeling difficulty (SKD), defined as a self-report of "severe" or "extreme" difficulty with kneeling. Absolute values of the KOOS Pain and Symptoms subscales were also compared. RESULTS: A total of 10,999 patients were analyzed. At 2-year follow-up, 9.3% (420/4492) reported CKP, and 12.0% (537/4471) reported SKD. The most important predictor of CKP at 2-year follow-up was having significant pain before surgery (adjusted odds ratio, 4.10; P < .001). The most important predictor of SKD at 2-year follow-up was the use of a BTB autograft rather than a hamstring tendon autograft (21.3% vs 9.4%, respectively; adjusted odds ratio, 3.12; P < .001). There was no difference between the BTB and hamstring tendon grafts in terms of CKP (9.9% vs 9.2%, respectively; P = .494) or in absolute values of the KOOS Pain (mean, 88.7 vs 89.0, respectively; P = .37) and KOOS Symptoms (mean, 82.5 vs 82.1, respectively; P = .49) subscales. CONCLUSION: At 2-year follow-up after primary ACL reconstruction, 9.3% of patients reported CKP, and 12.0% reported SKD. The BTB autograft was associated with difficulty with kneeling, but it did not result in a more painful or symptomatic knee compared with the hamstring tendon autograft.

Evaluation of Serum Albumin-Coated Bone Allograft for Bone Regeneration: A Seven-Year Follow-Up Study of 26 Cases.

We have previously reported that serum albumin-coated bone allograft (BoneAlbumin, BA) is an effective bone substitute. It improves bone regeneration at the patellar and tibial donor sites six months after harvesting bone-patellar tendon-bone (BPTB) autografts for primary anterior cruciate ligament reconstruction (ACLR). In the present study, we examined these donor sites seven years after implantation. The study group (N = 10) received BA-enhanced autologous cancellous bone at the tibial and BA alone at the patellar site. The control group (N = 16) received autologous cancellous bone at the tibial and blood clot at the patellar site. We evaluated subcortical density, cortical thickness, and bone defect volume via CT scans. At the patellar site, subcortical density was significantly higher in the BA group at both time points. There was no significant difference in cortical thickness between the two groups at either donor site. The control group's bone defect significantly improved and reached the BA group's values at both sites by year seven. Meanwhile, the bone defects in the BA group did not change significantly and were comparable to the six-month measurements. No complications were observed. There are two limitations in this study: The number of patients recruited is small, and the randomization of the patients could have improved the quality of the study as the control group patients were older compared to the study group patients. Our 7-year results seem to demonstrate that BA is a safe and effective bone substitute that supports faster regeneration of donor sites and results in good-quality bone tissue at the time of ACLR with BPTB autografts. However, studies with a larger number of patients are required to definitively confirm the preliminary results of our study.

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

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

The reverse fragility index: RCTs reporting non-significant differences in failure rates between hamstring and bone-patellar tendon-bone autografts have fragile results.

PURPOSE: The reverse fragility index (RFI) is a novel metric to appraise the results of studies reporting statistically non-significant results. The purpose of this study was to determine the statistical robustness of randomized controlled trials (RCTs) reporting non-significant differences in anterior cruciate ligament reconstruction (ACLR) graft failure rates, defined as re-rupture/revision ACLR rate, between hamstring tendon (HT) and bone-patellar tendon-bone (BTB) autografts by calculating RFIs. METHODS: A systematic review was performed to identify RCTs that compared HT to BTB grafts for ACLR through January 2022. Studies reporting non-significant differences in graft re-rupture and revision ACLR rate (n.s.) were included. The RFI, defined as the fewest number of event reversals needed to change the non-significant graft re-rupture/revision outcome to statistically significant (P < 0.05), was recorded for each study. In addition, the number of studies in which the loss to follow-up exceeded the RFI was recorded. RESULTS: Among the 16 included RCTs, the median (interquartile range [IQR]) sample size was 71 (64-114), and the median (IQR) total number of graft re-rupture/revision ACLR events was 4 (4-6). The median (IQR) graft re-rupture/revision ACLR rate was 4.3% (3.0-6.4) overall, 4.1% (2.6-6.7) in the BTB group, and 5.4% (3.0-6.3) in the HT group. The median (IQR) RFI was 3 (3-4), signifying that a reversal of the outcome in 3 patients in one arm was needed to flip the studies' result from non-significant to statistically significant (P < 0.05). The median (IQR) number of participants lost to follow-up was 11 (3-13), and 13 (81.3%) of the included studies had a loss to follow-up greater than the studies' RFI. CONCLUSION: The results of RCTs reporting statistically non-significant re-rupture/revision ACLR rates between HT and BTB autografts would become significant if the outcome were reversed in a small number of patients-a number that was less than the loss to follow-up in the majority of studies. Thus, the neutrality of these studies is fragile, and a true statistically significant difference in re-rupture/revision rates may have been undetected. LEVEL OF EVIDENCE: Level I.

[Efficacy comparison between a new generation of artificial ligaments and bone-patellar tendon-bone autograft for anterior cruciate ligament revision].

Objective: To compare the clinical efficacy of a new generation of ligaments (LARS artificial ligament) and bone-patellar tendon-bone (BPTB) autograft as grafts in anterior cruciate ligament (ACL) revision. Methods: A retrospective cohort study. The clinical data of 54 patients who underwent ACL revision from January 2018 to June 2020 in the First Hospital Affiliated to Army Medical University were retrospectively analyzed. There were 44 males and 10 females with a mean age of (28.5±7.7) years (15-45 years). Among them, 24 cases underwent ACL revision with LARS artificial ligament (LARS group), the other 30 cases underwent ACL revision with BPTB (BPTB group). The subjective and objective knee joint evaluation indexes were compared between the two groups to evaluate the clinical efficacy. The subjective evaluation indexes included Tegner score, Lysholm score and the International Knee Documentation Committee (IKDC) score. The objective evaluation indexes included the Lachman test, pivot-shift test, the anterior tibial translation (ATT) measurement at the weight-bearing position and the rate of patients returned to pre-injury sports. Results: The follow-up period was (32.8±5.3) months (24-42 months). At the last follow-up, the IKDC score, Tegner score and Lysholm score in the two groups significantly increased when compared with those before surgery (all P<0.05), and there was no significant difference in those indexes between the two groups (all P>0.05). The ATT measurement in the weight-bearing position was (3.1±0.7) mm in the LARS group and it was (4.1±0.9) mm in the BPTB group, which were significantly improved when compared with those before surgery (both P<0.05), and it was better in the LARS group than in the BPTB group (P<0.05). Postoperative Lachman test and pivot-shift test results in the LARS group were better than those in the BPTB group with statistically significant difference (both P<0.05). The rate of patients returned to pre-injury sports one year after surgery was 79.2%(19/24) in the LARS group and it was 50.0%(15/30) in the BPTB group, and the difference was statistically significant (P=0.029). Conclusions: Both LARS artificial ligament and BPTB autograft can achieve good short-term clinical efficacy in ACL revision, but LARS artificial ligament group has more advantages than BPTB autograft group in knee stability and early return to sports.

Lower donor site morbidity with hamstring and quadriceps tendon autograft compared with bone-patellar tendon-bone autograft after anterior cruciate ligament reconstruction: a systematic review and network meta-analysis of randomized controlled trials.

PURPOSE: To perform a meta-analysis of RCTs evaluating donor site morbidity after bone-patellar tendon-bone (BTB), hamstring tendon (HT) and quadriceps tendon (QT) autograft harvest for anterior cruciate ligament reconstruction (ACLR). METHODS: PubMed, OVID/Medline and Cochrane databases were queried in July 2022. All level one articles reporting the frequency of specific donor-site morbidity were included. Frequentist model network meta-analyses with P-scores were conducted to compare the prevalence of donor-site morbidity, complications, all-cause reoperations and revision ACLR among the three treatment groups. RESULTS: Twenty-one RCTs comprising the outcomes of 1726 patients were included. The overall pooled rate of donor-site morbidity (defined as anterior knee pain, difficulty/impossibility kneeling, or combination) was 47.3% (range, 3.8-86.7%). A 69% (95% confidence interval [95% CI]: 0.18-0.56) and 88% (95% CI: 0.04-0.33) lower odds of incurring donor-site morbidity was observed with HT and QT autografts, respectively (p < 0.0001, both), when compared to BTB autograft. QT autograft was associated with a non-statistically significant reduction in donor-site morbidity compared with HT autograft (OR: 0.37, 95% CI: 0.14-1.03, n.s.). Treatment rankings (ordered from best-to-worst autograft choice with respect to donor-site morbidity) were as follows: (1) QT (P-score = 0.99), (2) HT (P-score = 0.51) and (3) BTB (P-score = 0.00). No statistically significant associations were observed between autograft and complications (n.s.), reoperations (n.s.) or revision ACLR (n.s.). CONCLUSION: ACLR using HT and QT autograft tissue was associated with a significant reduction in donor-site morbidity compared to BTB autograft. Autograft selection was not associated with complications, all-cause reoperations, or revision ACLR. Based on the current data, there is sufficient evidence to recommend that autograft selection should be personalized through considering differential rates of donor-site morbidity in the context of patient expectations and activity level without concern for a clinically important change in the rate of adverse events. LEVEL OF EVIDENCE: Level I.

Quadriceps tendon autograft is comparable to hamstring tendon and bone-patella-tendon-bone up to 2 years after isolated primary anterior cruciate ligament reconstruction.

PURPOSE: To evaluate the functional and graft survivorship outcomes of the three most common autograft options for primary anterior cruciate ligament reconstruction (ACLR)-hamstring tendon (HT), bone-patella-tendon-bone (BPTB), and quadriceps tendon (QT). METHODS: Patients captured by the New Zealand ACL registry who underwent a primary ACLR from 2014 to 2020 were considered for the study. Patients with associated knee injury (including meniscus, chondral, osseous, and additional ligamentous injury) and previous knee surgery were excluded. Comparison was made between HT, BPTB, and QT autografts with respect to Marx and KOOS (Knee Osteoarthritis Outcome Score) scores at minimum 2 years follow-up. In addition, graft survivorship was evaluated by comparing all-cause revision per 100 graft years and revision-free proportion at 2 years post-surgery. RESULTS: 2,582 patients (1,921 HT, 558 BPTB, 107 QT) were included in the study. Differences in adjusted functional outcomes between HT and BPTB were found at 12 months (mean Marx; HT 6.2; BPTB 7.1; P < 0.001) (mean KOOS Sport and Recreation; HT 75.1; BPTB 70.5; n.s.) and 24 months (mean KOOS Sports and Recreation; HT 79.2; BPTB 73.9; P < 0.001). QT was comparable to HT and BPTB in all functional scores at 12 months and 2 years. No statistically significant differences were found in revision rate between all three autograft groups up to 2 years post-surgery (revision rate per 100 graft years; HT 1.05; BPTB 0.80; QT 1.68; n.s. HT vs. BPTB; n.s. HT vs. QT; n.s. QT vs. BPTB). CONCLUSIONS: QT was found to be comparable to both HT and BPTB in all functional scores and revision rates up to 2 years post-surgery. LEVEL OF EVIDENCE: Level III.

Consistent Indications and Good Outcomes Despite High Variability in Techniques for Two-Stage Revision Anterior Cruciate Ligament Reconstruction: A Systematic Review.

PURPOSE: To systematically review the current literature regarding the indications, techniques, and outcomes after 2-stage revision anterior cruciate ligament reconstruction (ACLR). METHODS: A literature search was performed using SCOPUS, PubMed, Medline, and the Cochrane Central Register for Controlled Trials according to the 2020 Preferred Reporting Items for Systematic Reviews and Meta Analyses statement. Inclusion criteria was limited to Level I-IV human studies reporting on indications, surgical techniques, imaging, and/or clinical outcomes of 2-stage revision ACLR. RESULTS: Thirteen studies with 355 patients treated with 2-stage revision ACLR were identified. The most commonly reported indications were tunnel malposition and tunnel widening, with knee instability being the most common symptomatic indication. Tunnel diameter threshold for 2-stage reconstruction ranged from 10 to 14 mm. The most common grafts used for primary ACLR were bone-patellar tendon-bone (BPTB) autograft, hamstring graft, and LARS (polyethylene terephthalate) synthetic graft. The time elapsed from primary ACLR to the first stage surgery ranged from 1.7 years to 9.7 years, whereas the time elapsed between the first and second stage ranged from 21 weeks to 13.6 months. Six different bone grafting options were reported, with the most common being iliac crest autograft, allograft bone dowels, and allograft bone chips. During definitive reconstruction, hamstring autograft and BPTB autograft were the most commonly used grafts. Studies reporting patient-reported outcome measures showed improvement from preoperative to postoperative levels in Lysholm, Tegner, and objective International Knee and Documentation Committee scores. CONCLUSIONS: Tunnel malpositioning and widening remain the most common indications for 2-stage revision ACLR. Bone grafting is commonly reported using iliac crest autograft and allograft bone chips and dowels, whereas hamstring autograft and BPTB autograft were the most used grafts during the second-stage definitive reconstruction. Studies showed improvements from preoperative to postoperative levels in commonly used patient reported outcomes measures. LEVEL OF EVIDENCE: Level IV, systematic review of Level I, III, and IV studies.

Comparison of Clinical Outcomes after Revision Anterior Cruciate Ligament Reconstruction using a Bone-patellar Tendon-bone Autograft and that Using a Double-Bundle Hamstring Tendon Autograft.

PURPOSE: The purpose of this study was to compare clinical outcomes between revision anterior cruciate ligament reconstruction (ACLR) using a bone-patellar tendon-bone (BPTB) autograft and that using a double-bundle hamstring tendon (HT) autograft. METHODS: Consecutive cases of revision ACLRs were reviewed. The Lysholm knee scale and Knee Osteoarthritis Outcome Score (KOOS) were recorded at the final follow-up. The pivot shift test, Lachman test, and anterior knee laxity measurement using an arthrometer were evaluated before revision ACLR and at final follow-up. Contralateral knee laxity was also evaluated, and side-to-side differences noted. The Lysholm knee scale, KOOS, the pivot shift test, Lachman test, and anterior knee laxity were compared between HT versus BPTB autograft recipient groups using the Mann-Whitney test or the t-test. RESULTS: Forty-one patients who underwent revision ACLR and followed up for at least 2 years were included. The graft source was a BPTB autograft in 23 patients (BPTB group) and a double-bundle HT autograft in 18 patients (HT group). The mean postoperative follow-up period was 44 ± 28 months in the BPTB group and 36 ± 18 in the HT group (p = 0.38). The HT group had significantly higher KOOS in the pain subscale (less pain) than the BPTB group at the final follow-up (BPTB group 84.2 vs. HT group 94.4; p = 0.02). The BPTB group showed significantly smaller side-to-side difference in anterior knee laxity (superior stability) than the HT group (0.3 vs. 2.6 mm; p < 0.01). The percentage of patients with residual anterior knee laxity in the BPTB group was significantly lower than that in the HT group (9.5% vs. 46.7%; odds ratio, 8.3; p = 0.02). STUDY DESIGN: This was a level 3 retrospective study. CONCLUSION: Revision ACLR with a BPTB autograft was associated with superior results regarding restoration of knee joint stability as compared with that with a double-bundle HT autograft, whereas double-bundle HT autograft was superior to BPTB autograft in terms of patient-reported outcomes of pain. The rest of the patient-reported outcomes were equal between the two groups.

Changes in patellar height after anatomical ACL reconstruction with BTB autograft with a focus on patellar tendon removal volume.

BACKGROUND: Although anatomical anterior cruciate ligament reconstruction (ACLR) can provide satisfactory outcomes, little is known about how this procedure impacts patellar height. Since harvesting bone-patellar tendon-bone (BTB) autografts is a potential risk factor for decreased patellar height, we examined changes in patellar height after anatomical ACLR with BTB autograft with a focus on the size of the harvested graft. METHODS: Subjects were 84 patients (49 males, 35 females; mean age, 23 years) who underwent primary anatomical ACLR with central third BTB autograft. Preoperative to postoperative Caton-Deschamps index (CDI) ratio was calculated using lateral knee radiographs before and 6 months after surgery. The length and cross-sectional area (CSA) of the graft were measured intraoperatively, and the CSA of the contralateral patellar tendon was measured by ultrasound 6 months postoperatively. The difference in graft CSA relative to the contralateral tendon CSA, expressed as a percentage (gCSA:ctCSA percentage), was also calculated. RESULTS: Patellar height decreased slightly after surgery (preoperative CDI: 0.856 ± 0.113; postoperative CDI: 0.841 ± 0.113), with a mean difference between preoperative and postoperative CDIs of -0.015 (range: -0.293 to 0.101). Although the CDI of male subjects significantly decreased after surgery (preoperative: 0.852 ± 0.117; postoperative: 0.827 ± 0.115), no significant changes were noted in female subjects (preoperative: 0.862 ± 0.108; postoperative: 0.861 ± 0.108). Graft length and CSA did not significantly impact the CDI ratio (r = -0.138 and r = -0.038, respectively). Moreover, no significant relationship was observed between the gCSA:ctCSA percentage and CDI ratio (r = 0.118). CONCLUSIONS: Although patellar height slightly, but significantly, decreased at 6 months after anatomical ACLR with BTB autograft, it was not affected by the length and CSA of harvested grafts. The decrease in postoperative patellar height was observed only in male subjects, suggesting the potential importance of sex differences in soft tissue healing during the postoperative period.

Bone filling decreases donor site morbidity after anterior cruciate ligament reconstruction with bone-patellar tendon-bone autografts.

PURPOSE: Bone-patellar tendon-bone (BTB) autograft remains the most widely used graft source for anterior cruciate ligament reconstruction (ACLR). The drawback associated with BTB is increased donor-site morbidity, such as anterior knee pain. The purpose of this study was to evaluate and compare anterior knee pain after refilling the patella bony defect with bone substitute. METHODS: This is a retrospective analysis of consecutive patients who underwent BTB ACLR at a single institution between January 2015 and December 2020. The cohort was divided into two groups; one in which the patellar bony defect was refilled with bone substitute (Bone Graft group) and another in which this the bony defects were not treated (No Bone Graft group). Demographic variables, reported anterior knee pain, visual analog scale (VAS) score, complications, re-operation, and patient reported outcome measures, such as the IKDC, LYSHOLM and SF-12 scores, were compared between groups. RESULTS: A total of 286 patients who underwent BTB ACLR were included. The No Bone Graft group included 88 (30.7%) patients and the Bone Graft group included 198 (69.3%) patients. The Bone Graft group had less anterior knee pain at last clinic follow up (33.3% vs. 51.1% p = 0.004) as well as lower VAS anterior knee pain scores (2.18 vs. 3.13, p = 0.004). The Bone Graft group had lower complications rates (21.7% vs 34.1, p = 0.027). No differences were found in the LYSHOLM, IKDC, and SF-12 scores. CONCLUSION: Bone refilling in BTB ACLR significantly reduces prevalence and severity of anterior knee pain. Larger randomized trials are needed to confirm the benefits of bone refilling in ACLR patients. LEVEL OF EVIDENCE: Retrospective study-III.

Revision ACL reconstruction using quadriceps, hamstring and patellar tendon autografts leads to similar functional outcomes but hamstring graft has a higher tendency of graft failure.

PURPOSE: The purpose of this study was to evaluate the differences in the patient-reported functional outcomes, and graft failure in revision ACL reconstruction using quadriceps tendon (QT), Hamstring tendon (HT) and bone-patellar tendon-bone (BPTB) autografts. METHODS: Between 2010 and 2020, 97 patients who underwent revision ACL reconstruction (40 patients received a QT, 26 an HT and 31 a BPTB graft) met the inclusion criteria. Pre-injury and at 2-year postoperatively patients were evaluated for patient-reported functional outcomes; Lysholm knee score, Tegner activity level and VAS (visual analogue scale) for pain; and graft failure. Patient-reported outcomes and graft failure were compared between the QT, HT and BPTB groups. The patients with graft failure were not included for outcome analysis at 2-years of follow-up. RESULTS: All three revision groups with QT, HT and BPTB autograft did not differ significantly in terms of age, sex, time from injury to surgery, concomitant injuries and single-stage or double-stage procedures (n.s.). No significant difference was found in the pre-injury patient-reported outcome; Lysholm knee score, Tegner activity and VAS for pain (n.s.) between the three groups. At the 2-year follow-up functional outcomes improved in all three groups and all the patients returned to pre-injury activity level; however, no significant difference was found in functional outcomes at the 2-year follow-up between the three groups (n.s.). Graft failure occurred in 4 (10%), 5 (19%) and 3 (10%) patients of QT, HT and BPTB groups, respectively. However, the rate of failure did not differ significantly between groups. CONCLUSION: All three autografts (QT, HT and BPTB) demonstrated satisfactory patient-reported outcomes in revision ACL reconstruction. Compared with QT and BPTB grafts, HT graft showed a higher tendency for failure rates. With the increasing incidence of revision ACL reconstruction, surgeons should be aware of all the available graft options. The findings of this study will assist the surgeons in the graft selection for revision ACL reconstruction. LEVEL OF EVIDENCE: Level III.

Clinical outcomes and complications after anterior cruciate ligament reconstruction with bone-patellar tendon-bone in patient Tanner 3 and 4: a systematic review.

BACKGROUND: Clinical outcomes and potential complications associated with Bone-Patellar Tendon-Bone (BPTB) graft in skeletally immature ACL reconstruction (ACLR) are poorly defined. Considering that in Tanner 1-2 patients this kind of graft is not recommended, we focused our systematic review on the evaluation of all the studies in the literature that reported clinical outcomes and rate of complications of the ACLR using BPTB graft in Tanner 3-4 patients. METHODS: This review was conducted in accordance with the PRISMA statement. PubMed, Cochrane Library, EMBASE and Scopus were examined from 1965 to 2020 using different combinations of the following keywords: "ACL reconstruction", "skeletally immature", "young", "patellar tendon" and "BPTB". The database search yielded 742 studies, on which we performed a primary evaluation. After carrying out a full-text evaluation for the inclusion criteria, 4 studies were included in the final review and assessed using the Newcastle-Ottawa scale. Ninety-six cases with mean age of 14.2 years were reported. RESULTS: Good stability and functional outcomes were reported with a mean follow-up of 49.5 months. Return to sport rate ranged from 91.7% to 100%. A KT-1000 side-to-side difference higher than 5 mm was observed in five patients (5.2%). No lower limb length discrepancy and angulation were reported. Graft rupture rate was 5.2%. CONCLUSION: According to these results, BTPB graft could be a good choice in Tanner 3-4 patients who want to achieve their preinjury sport level with a low risk of growth disturbances and graft failure. Further investigations in a wider population are needed.

Long-term results after anterior cruciate ligament reconstruction using patellar tendon versus hamstring tendon autograft with a minimum follow-up of 10 years-a systematic review.

INTRODUCTION: A lot of research addresses superiority of the two commonly used autografts bone-patellar tendon-bone (BPTB) and hamstring tendon for anterior cruciate ligament (ACL) reconstruction, without getting to consensus. While there are numerous studies and reviews on short- to mid-term follow-up, not much literature is available on long-term follow-up. As patients suffering ACL injuries are often of young age and high athletic activity, it is crucial to have the best evidence possible for graft choice to minimize consequences, like osteoarthritis later on. MATERIALS AND METHODS: A search of the online databases, PubMed and Embase, was carried out last on 31st March 2022 for studies comparing BPTB and hamstring tendon (HT) autografts for ACL reconstruction in human patients with a minimum follow-up of 10 years. The methodological quality of each study has been evaluated using the modified Coleman Methodology Score. Results on the three variables patient-oriented outcomes, clinical testing and measurements and radiographic outcomes were gathered and are presented in this review. RESULTS: Of 1299 records found, nine studies with a total of 1833 patients were identified and included in this systematic review. The methodological quality of the studies ranged from a Coleman Score of 63-88. Many studies reported no or only few statistically significant differences. Significant results in favour of BPTB were found for activity levels and for instrumented laxity testing with the KT-1000 arthrometer. Better outcomes for HT were found in IKDC-SKF, the KOOS, donor site morbidity, pivot shift test, radiographic osteoarthritis (IKDC C or D) and contralateral ACL rupture. No studies presented significant differences in terms of Lysholm Score or Tegner Activity Score, Lachman test, single-legged hop test, deficits in range of motion, osteoarthritis using the Kellgren and Lawrence classification or graft rupture. CONCLUSION: We cannot recommend one graft to be superior, since both grafts show disadvantages in the long-term follow-up. Considering the limitation of our systematic review of no quantitative analysis, we cannot draw further conclusions from the many insignificant results presented by individual studies. LEVEL OF EVIDENCE: IV.