Single nucleus and spatial transcriptomic profiling of healthy human hamstring tendon.

The molecular and cellular basis of health in human tendons remains poorly understood. Among human tendons, hamstring tendon has markedly low pathology and can provide a prototypic healthy tendon reference. The aim of this study was to determine the transcriptomes and location of all cell types in healthy hamstring tendon. Using single nucleus RNA sequencing, we profiled the transcriptomes of 10 533 nuclei from four healthy donors and identified 12 distinct cell types. We confirmed the presence of two fibroblast cell types, endothelial cells, mural cells, and immune cells, and identified cell types previously unreported in tendons, including different skeletal muscle cell types, satellite cells, adipocytes, and undefined nervous system cells. The location of these cell types within tendon was defined using spatial transcriptomics and imaging, and potential transcriptional networks and cell-cell interactions were analyzed. We demonstrate that fibroblasts have the highest number of potential cell-cell interactions in our dataset, are present throughout the tendon, and play an important role in the production and organization of extracellular matrix, thus confirming their role as key regulators of hamstring tendon homeostasis. Overall, our findings underscore the complexity of the cellular networks that underpin healthy human tendon function and the central role of fibroblasts as key regulators of hamstring tendon tissue homeostasis.

Metal interference screw fixation combinations show high revision rates in primary hamstring tendon ACL reconstruction.

BACKGROUND: Different fixation methods in anterior cruciate ligament reconstruction (ACLR) have been associated with different revision rates, specifically in the early postoperative period. However, most previous research has either grouped together different fixation types or evaluated femoral-sided fixation or tibial-sided fixation separately. Therefore, the purpose of this study was to determine ACL revision rates for specific combinations of femoral and tibial fixation methods within 2 years of primary hamstring tendon autograft ACLR based on data from the Swedish National Knee Ligament Registry (SNKLR). METHODS: Patients that underwent primary hamstring tendon autograft ACLR between 2005 and 2018 in the SNKLR were included. The collected data included patient characteristics (age, sex, body mass index [BMI]), activity at time of injury, surgical information (concomitant injuries, time from injury to surgery, fixation types at the femur and tibia), and subsequent revision ACLR. Revision rate within 2 years of the index procedure was chosen, as ACLR fixation is most likely to contribute to ACLR revision within the first 2 years, during graft maturation. RESULTS: Of the 23,238 included patients undergoing primary hamstring ACLR, 581 (2.5%) underwent revision ACLR within 2 years of the index procedure. Among the combinations used for > 300 patients, the femoral metal interference screw/tibial metal interference screw fixation combination had the highest revision rate followed by metal interference screw/resorbable screw and Endobutton/AO screw fixation combinations, with respective revision rates of 4.0, 3.0, and 3.0%. The lowest revision rate within 2 years of ACLR was found in the Endobutton/metal interference screw with backup Osteosuture fixation combination, used in 433 cases, with a failure rate of 0.9%. CONCLUSION: Different early ACL revision rates were found across different combinations of femoral and tibial fixation devices within 2 years of primary hamstring tendon autograft ACLR. Metal interference screw fixation, particularly when performed on both the femoral and tibial sides, most frequently resulted in revision ACLR. These findings may be helpful for surgeons in selecting appropriate fixation devices for hamstring ACLR. LEVEL OF EVIDENCE: IV.

Comparison of knee flexor strength recovery between semitendinosus alone versus semitendinosus with gracilis autograft for ACL reconstruction: a systematic review and meta-analysis.

BACKGROUND: Whether there is a difference in harvesting the semitendinosus tendon alone (S) or in combination with the gracilis tendon (SG) for the recovery of knee flexor strength after anterior cruciate ligament (ACL) reconstruction remains inconclusive. Therefore, this study aimed to assess the recovery of knee flexor strength based on the autograft composition, S or SG autograft at 6, 12, and ≥ 24 months after ACL reconstruction. METHODS: A systematic review and meta-analysis was conducted following the PRISMA guidelines. A comprehensive search was performed encompassing the Cochrane Library, Embase, Medline, PEDRo and AMED databases from inception to January 2023. Inclusion criteria were human clinical trials published in English, comprised of randomized controlled trials (RCTs), longitudinal cohort-, cross-sectional and case-control studies that compared knee flexor strength recovery between S and SG autografts in patients undergoing primary ACL reconstruction. Isokinetic peak torques were summarized for angular velocities of 60°/s, 180°/s, and across all angular velocities, assessed at 6, 12, and ≥ 24 months after ACL reconstruction. A random-effects model was used with standardized mean differences and 95% confidence intervals. Risk of bias was assessed with the RoBANS for non-randomized studies and the Cochrane RoB 2 tool for RCTs. Certainty of evidence was appraised using the GRADE working group methodology. RESULTS: Among the 1,227 patients from the 15 included studies, 604 patients received treatment with S autograft (49%), and 623 received SG autograft (51%). Patients treated with S autograft displayed lesser strength deficits at 6 months across all angular velocities d = -0.25, (95% CI -0.40; -0.10, p = 0.001). Beyond 6 months after ACL reconstruction, no significant difference was observed between autograft compositions. CONCLUSION: The harvest of S autograft for ACL reconstruction yields superior knee flexor strength recovery compared to SG autograft 6 months after ACL reconstruction, irrespective of angular velocity at isokinetic testing. However, the clinical significance of the observed difference in knee flexor strength between autograft compositions at 6 months is questionable, given the very low certainty of evidence and small effect size. There was no significant difference in knee flexor strength recovery between autograft compositions beyond 6 months after ACL reconstruction. TRIAL REGISTRATION: CRD42022286773.

Editorial Commentary: Quadriceps Tendon Is a Better Graft Than Hamstring for Anterior Cruciate Ligament Reconstruction.

Over the last 12 years identification of specific risk factors (age, activity level, and laxity) for failure of anterior cruciate ligament (ACL) reconstruction have led to comparisons of the patellar tendon (PT) and hamstring (HS) tendon grafts. The PT has proved superior in most of these studies. During this same time period, there has been increased clinical/research interest in the quadriceps tendon autograft for ACL reconstruction. This has led to direct comparison to the HS and QT autografts. Again, the HS tendon appears inferior in measured outcomes to the quadriceps tendon. Increased laxity measurements seem to correlate with the decreased evidence of radiographic healing on magnetic resonance imaging. If this is the case, it may indeed be the final nail in the coffin for HS graft use in young at-risk athletic populations.

Editorial Commentary: Gracilis-Sparing Anterior Cruciate Ligament Hamstring Graft Reconstruction Is Less Invasive Than Semitendinosus-Gracilis Graft Harvest, and Shows No Clinical Difference in Outcomes With Grafts Greater Than 8 mm in Diameter.

Although patellar tendon grafts are most commonly used for anterior cruciate ligament reconstruction in the United States, hamstring autograft is most commonly used worldwide. Hamstring advantages include easy, quick harvest; low morbidity; ease of rehabilitation (compared with patellar tendon grafts); and relatively less pain. Historically, both the semitendinosus (ST) and gracilis are harvested, but by doubling, tripling, or quadrupling the ST to achieve an 8-mm graft, the gracilis can be spared, resulting in less knee flexion weakness. However, recent research has shown no clinically important difference between ST and ST-gracilis patient outcomes.

Anterior Cruciate Ligament Repair Augmented With Dynamic Intraligamentary Stabilization Is Equivalent to Hamstring Autograft Reconstruction at Short- and Mid-Term Follow-Up: A Systematic Review.

PURPOSE: To compare clinical outcomes, knee stability and complications, failure, and revision rates after anterior cruciate ligament repair (ACLr) with dynamic intraligamentary stabilization (DIS) versus anterior cruciate ligament reconstruction (ACLR) with hamstring autograft for primary ACL ruptures at short and mid-term follow-up. METHODS: A Preferred Reporting Items for Systematic Reviews and Meta-Analyses-compliant systematic review of PubMed/MEDLINE and Scopus was performed. Studies that evaluated patients undergoing ACLr with DIS or ACLR with hamstring autograft were considered for inclusion. Studies were excluded if patients were affected by concomitant meniscal, ligamentous, or chondral injuries needing surgical treatment, because of their potential confounding effect on postoperative outcomes. The Risk of Bias-2 tool was used to assess the risk of bias in the included studies. The quality of available evidence was rated according to Grading of Recommendations Assessment, Development, and Evaluation recommendations. The study protocol was registered in the PROSPERO database (ID: CRD42023394558). RESULTS: Five randomized controlled trials comparing the outcomes of ACLr with DIS versus ACLR with hamstring autograft met the inclusion criteria. No major differences in terms of patient-reported outcomes (International Knee Documentation Committee subjective form, Lysholm score, Tegner activity scale, Knee injury and Osteoarthritis Outcome Score, visual analog scale satisfaction) or rates of complications, revisions, and failures were found in included studies at all time points. Repair showed greater International Knee Documentation Committee subjective form scores at 5 years in one study, whereas ACLR displayed significantly increased knee stability at 6 months and 5 years in 2 different studies, although the clinical relevance of these differences is doubtful. CONCLUSIONS: The results of this study suggest that ACLr with DIS is not inferior to ACLR with hamstring autograft in terms of rates of clinical outcomes, knee stability, risk of failure, complications, and revision surgery. Therefore, ACLr with DIS may be a viable alternative to ACLR with hamstring autograft in selected patients. LEVEL OF EVIDENCE: Level I, systematic review of Level I studies.

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.

Suture Tape Augmentation Improves Posterior Stability After Isolated Posterior Cruciate Ligament Reconstruction Using Hamstring Tendon Autograft With Single-Bundle Transtibial Technique.

PURPOSE: To assess whether posterior cruciate ligament reconstruction (PCLR) with suture tape augmentation can yield more stability after isolated PCLR. METHODS: A prospective database was retrospectively reviewed to identify patients who underwent primary isolated PCLR (control group) or isolated PCLR with suture tape augmentation (study group) from January 2016 to September 2020. We analyzed subjective International Knee Documentation Committee (IKDC), Lysholm, and Tegner knee scores; posterior drawer test findings; posterior stress radiographs; and return-to-sports activity rates. The minimal clinically important difference (MCID) was used to evaluate clinical relevance (subjective IKDC, Lysholm, and Tegner scores). RESULTS: A total of 59 patients were included in this analysis (28 in control group and 31 in study group). The average length of follow-up was similar between the study and control groups (48.6 months vs 47.9 months, P = .800). Knee function was significantly improved in the study group in terms of subjective IKDC scores (85.1 ± 6.4 in study group vs 79.8 ± 6.4 in control group, P = .002), Lysholm scores (86.3 ± 7.4 vs 80.8 ± 7.4, P = .005), and Tegner scores (7.0 ± 1.4 vs 5.6 ± 1.7, P = .006). However, the differences between the control and study groups were less than the MCID for the subjective IKDC score and Lysholm score. In the control and study groups, 21.4% of patients (6 of 28) and 48.4% of patients (15 of 31), respectively, returned to their preinjury sports activity levels (P = .031). At last follow-up, the mean side-to-side difference in posterior laxity was significantly improved in the study group compared with the control group (1.52 ± 0.70 mm in study group vs 3.17 ± 2.01 mm in control group, P < .01). CONCLUSIONS: Primary isolated PCLR with suture tape augmentation provides better posterior stability than PCLR without suture tape augmentation at a minimum of 2 years' follow-up. No differences between the groups were observed in the percentage of patients who met or exceeded the MCID for the subjective IKDC and Lysholm scores. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Difference of Knee Strength Recovery Between Revision and Primary ACL Reconstruction.

Different grafting procedures are available to restore knee stability after revision anterior cruciate ligament (ACL) reconstruction. We compared knee strength recovery between ACL revision surgery and primary reconstruction. One hundred and ten patients with ACL revision surgery were matched with 110 patients with primary reconstruction based on the graft procedure. The isokinetic knee strength had been assessed for the first 9 months post-surgery. Knee laxity, function, and activity score were also evaluated. Limb symmetry index for knee extensor and flexor strength was not different at 4-, 6- and 9-months post-surgery between revision surgery and primary reconstruction. These results depended on ipsilateral or contralateral graft choice. Ipsilateral hamstring tendon (HT) and contralateral bone-patellar-tendon-bone (BPTB) graft procedures were similar for a revision of a BPTB graft failure. Contralateral HT procedure was better than ipsilateral BPTB procedure for a revision of a HT graft failure. The early recovery of isokinetic knee strength after ACL revision surgery regardless of the HT or BPTB procedures, was similar to the recovery after primary ACL reconstruction with the same graft technique. These results apparently depended on a temporary quadriceps arthrogenic muscle inhibition and on a persistent donor site morbidity, concerning the new and the previous grafts, respectively.

Surgical treatment of distal hamstring tendon injuries yield a higher return-to-sports rate: A systematic review.

PURPOSE: The purpose of this study is to compare the patient-reported outcomes and return to sports of the conservative and surgical treatment of distal hamstring tendon injuries. METHODS: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, two reviewers searched PubMed, Scopus and Virtual Health Library databases in January 2023. Clinical studies evaluating conservative or surgical management outcomes of distal hamstring tendon injuries were considered eligible for this systematic review if predefined criteria were fulfilled: (1) published in English or Spanish; (2) evaluated any of the following: patient-reported outcomes, return-to-sports rate (RTS-R) or return-to-sports time (RTS-T). Data were presented in tables using absolute values from individual studies and derived pooled percentages. RESULTS: Eighteen studies were included for 67 patients and 68 distal hamstring tendon injuries. Initially, 39 patients (58.2%) underwent surgical treatment, whereas 28 (41.8%) were treated conservatively. Among conservative treatment patients, 15 failed and had to be operated on (53.6%), all with distal semitendinosus tendon injuries. Anchor fixation was the technique of choice in 20 lesions (36.4%), tenodesis in 16 (29.1%), tenectomy in 14 (25.5%) and sutures were preferred in five (9%). Thirteen out of 28 patients (46.4%) undergoing initial conservative treatment returned to sports at a mean of 3.6 months (range 1 week to 12 months), in contrast to surgical treatment, in which 36 out of 39 patients (92.3%) returned at a mean of 4.2 months (range 6 weeks to 12 months). Additionally, 14 of 15 patients (93.3%) converted to surgical treatment after failed conservative treatment returned to sports at a mean of 7.6 months after injury. CONCLUSION: Initial surgical treatment of distal hamstring tendon injuries yields a high RTS-R (92.3%) at a mean of 4.2 months. Furthermore, 15 out of 28 patients (53.6%) initially treated conservatively had to be operated on, delaying the RTS-T (mean 7.6 months after injury) without affecting their RTS-R. LEVEL OF EVIDENCE: IV.

Valgus malalignment causes increased forces on a medial collateral ligament reconstruction under dynamic valgus loading: A biomechanical study.

PURPOSE: To investigate the forces on a medial collateral ligament (MCL) reconstruction (MCLR) relative to the valgus alignment of the knee. METHODS: Eight fresh-frozen human cadaveric knees were subjected to dynamic valgus loading at 400 N using a custom-made kinematics rig. After resection of the superficial medial collateral ligament, a single-bundle MCLR with a hamstring tendon autograft was performed. A medial opening wedge distal femoral osteotomy was performed and fixed with an external fixator to gradually adjust the alignment in 5° increments from 0° to 10° valgus. For each degree of valgus deformity, the resulting forces acting on the MCLR were measured through a force sensor and captured in 15° increments from 0° to 60° of knee flexion. RESULTS: Irrespective of the degree of knee flexion, increasing valgus malalignment resulted in significantly increased forces acting on the MCLR compared to neutral alignment (p < 0.05). Dynamic loading at 5° valgus resulted in increased forces on the MCLR at all flexion angles ranging between 16.2 N and 18.5 N (p < 0.05 from 0° to 30°; p < 0.01 from 45° to 60°). A 10° valgus malalignment further increased the forces on the MCLR at all flexion angles ranging between 29.4 N and 40.0 N (p < 0.01 from 0° to 45°, p < 0.05 at 60°). CONCLUSION: Valgus malalignment of the knee caused increased forces acting on the reconstructed MCL. In cases of chronic medial instabilities accompanied by a valgus deformity ≥ 5°, a realigning osteotomy should be considered concomitantly to the MCLR to protect the graft and potentially reduce graft failures. LEVEL OF EVIDENCE: Level III.

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.

External validation of the Norwegian anterior cruciate ligament reconstruction revision prediction model using patients from the STABILITY 1 Trial.

PURPOSE: A machine learning-based anterior cruciate ligament (ACL) revision prediction model has been developed using Norwegian Knee Ligament Register (NKLR) data, but lacks external validation outside Scandinavia. This study aimed to assess the external validity of the NKLR model (https://swastvedt.shinyapps.io/calculator_rev/) using the STABILITY 1 randomized clinical trial (RCT) data set. The hypothesis was that model performance would be similar. METHODS: The NKLR Cox Lasso model was selected for external validation owing to its superior performance in the original study. STABILITY 1 patients with all five predictors required by the Cox Lasso model were included. The STABILITY 1 RCT was a prospective study which randomized patients to receive either a hamstring tendon autograft (HT) alone or HT plus a lateral extra-articular tenodesis (LET). Since all patients in the STABILITY 1 trial received HT ± LET, three configurations were tested: 1: all patients coded as HT, 2: HT + LET group coded as bone-patellar tendon-bone (BPTB) autograft, 3: HT + LET group coded as unknown/other graft choice. Model performance was assessed via concordance and calibration. RESULTS: In total, 591/618 (95.6%) STABILITY 1 patients were eligible for inclusion, with 39 undergoing revisions within 2 years (6.6%). Model performance was best when patients receiving HT + LET were coded as BPTB. Concordance was similar to the original NKLR prediction model for 1- and 2-year revision prediction (STABILITY: 0.71; NKLR: 0.68-0.69). Concordance 95% confidence interval (CI) ranged from 0.63 to 0.79. The model was well calibrated for 1-year prediction while the 2-year prediction demonstrated evidence of miscalibration. CONCLUSION: When patients in STABILITY 1 who received HT + LET were coded as BPTB in the NKLR prediction model, concordance was similar to the index study. However, due to a wide 95% CI, the true performance of the prediction model with this Canadian and European cohort is unclear and a larger data set is required to definitively determine the external validity. Further, better calibration for 1-year predictions aligns with general prediction modelling challenges over longer periods. While not a large enough sample size to elicit the true accuracy and external validity of the prediction model when applied to North American patients, this analysis provides more support for the notion that HT plus LET performs similarly to BPTB reconstruction. In addition, despite the wide confidence interval, this study suggests optimism regarding the accuracy of the model when applied outside of Scandinavia. LEVEL OF EVIDENCE: Level 3, cohort study.

Tendon cross-sectional area on magnetic resonance imaging and anthropometric characteristics can be used to predict insufficient four-strand hamstring autograft diameter in anterior cruciate ligament reconstruction: A systematic review.

PURPOSE: To evaluate the utility of semitendinosus tendon (ST) and gracilis tendon (GT) cross-sectional area (CSA) on magnetic resonance imaging (MRI) and anthropometric characteristics in preoperative estimation of graft diameter in patients undergoing anterior cruciate ligament reconstruction (ACLR) with four-strand hamstring autografts. METHODS: Three databases were searched on 29 August 2023. The authors adhered to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and R-AMSTAR (Revised Assessment of Multiple Systematic Review) guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. Data on demographics, anthropometric characteristics, imaging techniques, tendon CSA, correlation coefficients, sensitivities, specificities, regression models and cutoffs for predicting intraoperative graft diameters above 8 mm were recorded. RESULTS: Forty-six studies comprising 4140 patients were included. Twelve of 19 (63.2%) studies reporting on ST + GT CSA found a moderate to very high correlation with intraoperative graft diameter. Five of 10 (50%) and one of seven (14.3%) studies reporting on ST CSA and GT CSA, respectively, found a moderate to high correlation with intraoperative graft diameter. Cutoffs of ST + GT CSA for predicting graft diameters above 8 mm ranged from 15.8 to 31.2 mm2. Nine of 35 (25.7%) studies that reported on height found a moderate to very high correlation with graft diameter. Seven of 33 (21.2%) studies reporting on weight found a moderate correlation with graft diameter. CONCLUSION: Of the MRI parameters assessed, ST + GT CSA was the most reliable predictor of graft diameter. However, cutoffs, sensitivities, and specificities for predicting diameters above 8 mm were highly variable. Anthropometric characteristics in general were less predictive of graft diameter than MRI parameters. This information can be used by clinicians to predict patients at risk for ACLR failure due to insufficient graft size. LEVEL OF EVIDENCE: Level IV.

Bone-patellar tendon-bone autograft is associated with a higher rate of return to preinjury levels of performance in high-level athletes than anterior cruciate ligament reconstruction using hamstring autograft.

PURPOSE: Return to preinjury levels of performance (RTP) is the main goal after anterior cruciate ligament reconstruction (ACL-R) for athletes when ACL graft rupture is a career-threatening event. The purpose of this study was to elucidate the associated factors for RTP and subsequent ACL injury after ACL-R using bone-patellar tendon-bone (BPTB) or hamstring (HT) autograft in high-level athletes with a minimum postoperative follow-up of 24 months. METHODS: This retrospective study included 157 patients who had preinjury Tegner activity level of 9 and underwent primary ACL-R using BPTB (average age, 16.9 years; 35 males and 36 females) or HT (average age, 17.2 years; 49 males and 37 females). The mean follow-ups were 33.6 months in BPTB and 44.5 months in HT, respectively. The data were obtained based on routine clinical follow-ups and telephone interviews performed by the surgeon. Multivariate logistic regression analysis was conducted to determine the association of patient variables with RTP and subsequent ACL injury. RESULTS: Ninety-nine patients (63.1%) were able to RTP. The rate of RTP in BPTB (74.6%) was significantly higher than that of HT (53.5%) (p < 0.05). The overall average timing of RTP after ACL-R was 10.0 months while that was significantly earlier in BPTB (9.7 months) than in HT (10.5 months) (p < 0.05). Twenty-three (14.6%) and 21 patients (13.4%) had ACL graft ruptures and ACL injuries in the contralateral knees, respectively. Multivariate analyses showed that BPTB (odds ratio [OR], 2.590; 95% confidence interval [CI], 1.300-5.160; p = 0.007) was associated with a higher potential for RTP after ACL-R. The incidence of ACL graft rupture after ACL-R decreased with BPTB (OR, 0.861; 95% CI, 0.770-0.962; p = 0.009). CONCLUSIONS: The use of BPTB autograft was associated with a higher rate of RTP and a lower incidence of ACL graft rupture compared to ACL-R using HT autograft. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Influence of female sex and double-quadruple semitendinosus-gracilis graft on the incidence of postoperative symptomatic cyclops lesions after ACL reconstruction.

PURPOSE: Risk factors for the development of symptomatic cyclops lesion after anterior cruciate ligament reconstruction (ACLR) surgery are not entirely identified yet. This study aimed to investigate whether the choice of hamstring graft (semitendinosus-gracilis; STG vs. semitendinosus; ST) affects the risk of developing a symptomatic cyclops lesion after ACLR. METHODS: This retrospective cohort study included 1416 patients receiving either an ST graft (n = 1209) or an STG graft (n = 207) ACLR with a follow-up of at least 2 years. A persisting extension limitation was clinically determined, and cyclops lesions were confirmed by magnetic resonance imaging (MRI) and second-look arthroscopy. Graft-specific incidence of cyclops lesions was examined with χ2 test and combined with the factors number of graft bundles, graft diameter and sex evaluated with a binominal logistic regression model. RESULTS: In total, 46 patients developed symptomatic cyclops lesions (3.2%), with 36 having ACLR with an ST graft (3.0%) and 10 with an STG graft (4.8%) (n.s). The mean time from ACLR to the second-look arthroscopy for cyclops removal was 1.1 ± 0.6 years. Female patients were 2.5 times more likely to develop a cyclops lesion than male patients. Patients with an STG graft and larger graft diameters did not have a higher risk of developing cyclops lesions. Patients who received an STG graft with both tendons folded four times (double-quadruple) had significantly higher risk of developing a cyclops compared with all other numbers of graft bundles combined (8.3%, respectively 3.0%; p = 0.014). CONCLUSION: This study could not prove an increased risk of developing a symptomatic cyclops lesion for patients with an STG graft compared with an ST graft used for ACLR. However, patients with a double-quadruple ACLR had a higher percentage of cyclops lesions compared with all other numbers of graft bundles. Female sex was associated with an increased risk of developing cyclops lesions. LEVEL OF EVIDENCE: Level III.

Coracoclavicular and acromioclavicular ligament reconstruction with a double-bundle semitendinosus autograft and cortical buttons for chronic acromioclavicular joint dislocations: clinical and imaging outcomes.

BACKGROUND: There are few clinical and radiographic studies of coracoclavicular (CC) ligament reconstruction in chronic acromioclavicular (AC) joint dislocation. Additionally, reported AC joint reduction rates vary. HYPOTHESIS: Arthroscopically assisted double-bundle semitendinosus tendon autografts with CC and AC ligament reconstruction for AC joint reconstruction provide AC joint stability and improved function at the final visit. METHODS: In this retrospective study of prospectively collected data, 21 patients surgically treated for chronic AC joint dislocation (Rockwood III-V) were assessed clinically and radiographically preoperatively, and at day 1, 3 months, 12 months, and at a final visit (>24 months) postoperatively. Clinical assessments included Constant and American Shoulder and Elbow Surgeons scores. The CC vertical distance (CCD) on the affected and unaffected sides [CCD ratio (%)] on the anterosuperior view were measured. AC joint vertical reduction loss was defined as an increase in the CCD ratio of >25%. Horizontal AC joint instability was evaluated on axillary views. Pearsons' correlation coefficients were generated to examine the relationships among postoperative clinical scores, CCD ratio, interval from injury to surgery, and age at the time of surgery. RESULTS: Twenty-one shoulders in 21 patients (mean age, 40.0 years at the time of surgery; 16 men, 5 women) were evaluated with a mean 31.7-month follow-up period. The mean Constant scores, American Shoulder and Elbow Surgeons scores, and CCD ratios significantly improved from preoperatively to the final visit (57.4 ± 10.1, 49.1 ± 12.1, 101.6 ± 64.1 preoperatively; 89.6 ± 5.3, 96.5 ± 4.2, 9.9 ± 34.5 at the final visit, respectively [P < .001 for all]). Vertical AC and horizontal AC joint instability were observed in 4 shoulders (19.0%) and in 1 shoulder (4.8%), respectively. However, there was no significant correlation between the increase in CCD and clinical scores at the final visit (Constant score; r = 0.179, P = .438: American Shoulder and Elbow Surgeons score; r = -0.260, P = .256) or the interval from injury to surgery (r = 0.099, P = .669) or age at the time of surgery (r = 0.019, P = .935). No clinical complications were associated with clinical symptoms. CONCLUSIONS: Patients who underwent the index procedure achieved significant improvement in shoulder function without complications related clinical symptom after a mean follow-up interval of 31.7 months. In contrast, the rates of total ACJ instability in the vertical and horizontal planes were unsatisfactory but compatible with those in previous studies.

Single bundle hamstrings autograft preparation techniques for anterior cruciate ligament reconstruction: current concepts.

Anterior cruciate ligament reconstruction (ACLR) is one of the most common orthopedic procedures, and huge variation exists in the surgical technique. Single bundle hamstrings autograft reconstruction is a common method and has good clinical outcomes. A criticism of the hamstrings autograft is a small graft diameter, often less than 8-mm, which has been associated with increased re-rupture rates. Several graft preparation techniques for single bundle hamstrings autograft exist. Perioperative decisions include the number of tendons utilized, number of graft strands, graft configuration, and femoral and tibial fixation methods. Awareness of the minimum tendon and graft length required to produce each graft variation is necessary to avoid common pitfalls. However, intraoperative graft modification is possible to maximize graft diameter, and obtain proper fixation. The objective of this current concepts review is to describe the indications, surgical anatomy, technique, intraoperative tips, clinical outcomes, and complications for single bundle hamstrings autograft preparation techniques in ACLR.

Periosteal wrapping of the hamstring tendon autograft improves graft healing and prevents tunnel widening after anterior cruciate ligament anatomic reconstruction.

INTRODUCTION: The periosteum is a readily available tissue at the hamstring harvest site that could be utilized to enhance graft healing and prevent tunnel widening without additional cost or morbidity. This study aimed to compare graft healing using magnetic resonance imaging (MRI) and functional clinical outcome scores in a matched cohort of patients who underwent anterior cruciate ligament (ACL) reconstruction with hamstring autografts with or without periosteal augmentation. MATERIAL AND METHODS: Forty-eight patients who underwent ACL reconstruction (ACLR) were prospectively enrolled: 25 with standard ACLR (ST-ACLR) and 23 with periosteal augmented grafts (PA-ACLR). The same surgical techniques, fixation methods, and postoperative protocol were used in both groups. Signal-to-noise quotient (SNQ), graft healing at the bone-graft interface, graft signal according to the Howell scale, and femoral tunnel widening were evaluated using MRI after 1 year of follow-up. International knee documentation score (IKDC), Lysholm, Tegner activity scale, and visual analog scale for pain were used for functional evaluation at a minimum of 2 years postoperative. RESULTS: The mean SNQ of the proximal part of the graft was 9.6 ± 9.2 and 2.9 ± 3.3 for the ST-ACLR and PA-ACLR groups, respectively (P = 0.005). The mean femoral tunnel widening was 30.3% ± 18.3 and 2.3% ± 9.9 for the ST-ACLR, PA-ACLR groups, respectively (P < 0.001). Complete graft tunnel healing was observed in 65% and 28% of cases in the PA-ACLR and ST-ACLR groups, respectively. Both groups showed marked improvements in functional scores, with no statistically significant differences. CONCLUSION: Periosteal wrapping of hamstring tendon autografts is associated with better graft healing and maturation and lower incidence of femoral tunnel widening based on MRI analysis 1 year after ACL reconstruction. However, patient-reported outcomes and measured laxity were similar between the two groups at 2 years follow up. TRIAL REGISTRATION: Trail registration number: PACTR202308594339018, date of registration: 1/5/2023, retrospectively registered at the Pan African Clinical Trial Registry (pactr.samrc.ac.za) database.

Eighteen-year outcome of anterior cruciate ligament reconstruction with patellar tendon or hamstring autograft.

PURPOSE: To evaluate patient reported outcomes and radiographic arthritic changes of transtibial anterior cruciate ligament reconstruction (ACLR) with either bone-patellar tendon-bone (BPTB) or hamstrings (HS) auto-grafts at a minimum of 15-year follow-up. METHODS: Ninety-four patients (51 of the HS group, 43 of BPTB group) who were operated between the years 2000 to 2005 in two tertiary referral hospitals were contacted and invited to a retrospective evaluation. The interview included subjective outcomes using the Lysholm knee scoring questionnaire, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Tegner activity level scale, Visual Analogue Scale (VAS) for pain and patients' satisfaction scale. Knee examination included measurements of motion and stability. Knee radiographs were evaluated for osteoarthritic changes according to the Kellgren-Lawrence (KL) score. RESULTS: The average evaluation time from surgery was 18.6 years. Subjectively, there was no significant difference between groups except for a better post-operative level of activity and satisfaction in the HS group. Objectively, there was no significant difference between groups in knee stability and range of motion. Most patients had grade KL ≤ 1 radiographic osteoarthritits changes and there was no significant difference between groups. Recurrent complete tear of the reconstructed graft occurred in 3 patients of each group. In both groups 84% had no further surgery while the indications for further surgery were mostly a meniscal tear or tibial hardware removal. CONCLUSIONS: Very long-term outcomes and clinical stability of transtibial HS or BPTB graft ACL reconstruction are good with low rate of graft failure and radiographic osteoarthritis.