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Background and Objective: Due to growing numbers of primary total hip replacement (THR), the revision THR burden is also increasing. Common indications for revision are osteolysis, infection, instability, and mechanical failure of implants, which can cause acetabular bone loss. Massive acetabular bone defects and pelvic discontinuity are extremely challenging problems. Many techniques have been utilized to address bone loss while maintaining a stable revision THR. Structural allografts, cemented prosthesis, reconstruction cages, and custom triflanged implants have all been used successfully albeit with relatively high complications rates. We have tried to highlight emerging trends to utilize Custom Made Monoflange or Triflange Acetabular Components to reconstruct massive acetabular defects with favourable midterm implant survival, better functional outcomes, relatively lesser complications, and almost similar cost of prosthesis as compared to conventional reconstruction techniques. However, long-term data and study is still recommended to draw a definitive conclusion., Methods: In this narrative review article, we searched PubMed and Cochrane for studies on managing acetabular bone loss in revision THR with a focus on recent literature for mid to long-term outcomes and compared results from various studies on different reconstruction methods., Key Content and Findings: Hemispherical cementless acetabular prosthesis with supplemental screws are commonly utilized to manage mild to moderate acetabular bone loss. Recent trends have shown much interest and paradigm shift in patient specific custom triflange acetabular components (CTAC) for reconstructing massive acetabular defects and pelvic discontinuity. Studies have reported high patient satisfaction, improved patient reported daily functioning, high mid-term implant survival, similar complications, and encouraging all cause re-revision rate. However, more prospective and quality studies with larger sample sizes are needed to validate the superiority of CTACs over conventional acetabular implants., Conclusions: There is no consensus regarding the best option for reconstructing massive acetabular defects. Thorough preoperative workup and planning is an absolute requirement for successful revision THR. While most of the moderate acetabular bone loss can be managed with cementless hemispherical acetabular shells with excellent long-term outcomes, reconstructing massive acetabular bone defects in revision THR remains a challenge. Depending on the size and location of the defect, various constucts have demonstrated long-term success as discussed in this review, but complications are not negligible. CTACs provide a treatment for massive bone loss that may be otherwise difficult to achieve anatomic stability with other constructs. Although long-term data is sparse, the cost and complication rate is comparable to other reconstruction methods., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://aoj.amegroups.org/article/view/10.21037/aoj-23-23/coif). The series “Revision Total Hip Arthroplasty” was commissioned by the editorial office without any funding or sponsorship. A.F.K. reports that he receives IP royalties from Innomed; is a paid consultant for BodyCad, Zimmer, Ortho Development and United Ortho; is a board or committee member of AAOS and AAHKS; and has stock or stock options in Johnson & Johnson, Procter & Gamble and Zimmer. The authors have no other conflicts of interest to declare., (2024 Annals of Joint. All rights reserved.)

Background: Metal-on-metal hip resurfacing is an alternative to total hip arthroplasty (THA). The aim of this study was to determine implant survivorship, analyze patient-reported outcomes measures and to determine patient satisfaction for patients who underwent metal-on-metal hip resurfacing at a large US academic institution by a single surgeon with a minimum of 10-year follow-up., Methods: Patients who underwent hip resurfacing from September 2006 through November 2009 were included. Patient demographics and variables were collected from a prospectively maintained institutional database and patients completed an additional questionnaire with patient-reported outcomes measures., Results: A total of 350 patients (389 hips) out of 371 (433 hips) with a minimum 10-year follow-up were successfully contacted (94.3% follow-up). Mean age was 53 years, 258 were male (73%). 377 out of 389 hips (96.9%) did not require additional surgery. Gender was significantly related to implant survivorship (males 99.0%, females 90.9%; P < .001). 330 patients (369 hips, 94.8%) were satisfied with their surgery. Males had higher proportion of satisfaction scores (P = .02) and higher modified Harris Hip Score (odds ratio = 2.63 (1.39, 4.98), P = .003). Median modified Harris Hip Score score for non-revised hips was 84.0 [80.0; 86.0] versus those requiring revision, 81.5 [74.0; 83.0], (P = .009)., Conclusion: At a minimum 10-year follow-up, hip resurfacing, using an implant with a good track record, demonstrates 99.0% survivorship in male patients with an average age of 52 years. We believe that the continued use of metal-on-metal hip resurfacing arthroplasty in this population is justified by both positive patient reported outcomes and survivorship., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Venous thromboembolism (VTE) is a potential postoperative complication after total hip arthroplasty (THA). These events present with a range of severity, and some require readmission. The present study aimed to identify unexplored risk factors for severe VTE that lead to hospital readmission., Methods: The Agency of Healthcare Research and Quality's National Readmissions Database was retrospectively queried for all patients who underwent primary THA (January 2016 to December 2018). Study population included patients who were readmitted for VTE within 90 days after an elective THA. Bivariate and multivariate regression analyses were performed using patient demographics, insurance status, elective nature of the surgery, healthcare institution characteristics, and baseline comorbidities., Results: Higher risk of readmission for VTE was evident among elderly (71-80 years vs <40 years: odds ratio [OR] 1.7, 95% confidence interval [CI] 1.3-2.2, P = .0002), male patients (OR 1.2, 95% CI 1.2-1.3). Nonelective THAs were associated with markedly higher odds of readmission for VTE (OR 20.5, 95% CI 18.9-22.2), peripheral vascular disease (OR 1.2, 95% CI 1.1-1.4), lymphoma (OR 1.5, 95% CI 1.1-2.1), metastatic cancer (OR 1.8, 95% CI 1.4-2.2), obesity (OR 1.5, 95% CI 1.4-1.6), and fluid-electrolyte imbalance (OR 1.1, 95% CI 1.0-1.2). Home health care (OR 0.8, 95% CI 0.7-0.8) and discharge to skilled nursing facility (OR 0.7, 95% CI 0.7-0.8) had lower odds of readmission for VTE vs unsupervised home discharge, while insurance type was not a significant driver(P > .05)., Conclusion: One in 135 THA patients is likely to experience a VTE requiring readmission after THA. Male patients, age >70 years, and specific baseline comorbidities increase such risk. Furthermore, discharge to a supervised setting mitigated the risk of VTE requiring readmission compared to unsupervised discharge. As VTE prophylaxis protocols continue to evolve, these patients may require optimized perioperative care pathways to mitigate VTE complications., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Purpose: To directly compare subjective and objective outcomes of arthroscopic suprapectoral biceps tenodesis (ASPBT) below the bicipital groove and open subpectoral biceps tenodesis (OSPBT) performed with interference screw fixation., Methods: A total of 77 patients indicated for biceps tenodesis who met the inclusion and exclusion criteria were randomized into the ASPBT and OSPBT groups. All tenodesis procedures implemented PEEK (polyether ether ketone) interference screws. Patients underwent a clinical examination that included range of motion and strength assessment at 3, 6, and 12 months postoperatively. Patients completed the American Shoulder and Elbow Surgeons (ASES) shoulder score, Single Assessment Numeric Evaluation score, and Constant score preoperatively and at 6 and 12 months postoperatively., Results: Seventy-five patients were analyzed with a mean age of 50.3 ± 10.4 years and a mean body mass index of 28.9 ± 6.3. All patients had arthroscopic evidence of biceps pathology and underwent either an ASPBT (n = 37) or OSPBT (n = 38). The surgical time was significantly greater for ASPBT than for OSPBT (16.9 ± 8.4 minutes vs 9.8 ± 3.1 minutes, P < .001). One patient underwent conversion from the ASPBT group to the OSPBT group because of shearing of a severely attenuated tendon preventing an ASPBT. No significant difference (P > .05) was found in strength or anterior shoulder pain at 3 months, 6 months, and 1 year, and no significant difference (P > .05) was found in clinical outcome scores (ASES, Constant subjective, and Single Assessment Numeric Evaluation) between the 2 groups at 6 months and 1 year. The improvement in the ASES score exceeded the minimal clinically important difference (12 points) in both groups., Conclusions: No differences in patient-reported outcome measures, functional outcomes, or complication rates were found after ASPBT compared with OSPBT. However, the results of this investigation must be interpreted with caution because this study may be underpowered to detect statistical differences., Level of Evidence: Level I, randomized controlled trial., (Copyright © 2019 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: Sport-specific, performance-based outcomes are increasingly used to improve evaluation of treatment efficacy in elite athletes; however, its usage in elite soccer may be limited. The purpose of this investigation is to (1) assess current outcome reporting in elite soccer; (2) identify any variability in reporting of outcomes; and (3) determine how sport-specific performance-based outcomes are utilized to assess treatment efficacy in elite soccer., Methods: A systematic review of the Pubmed, MEDLINE, and Embase, Scopus, SportDiscus, CINAHL and HealthSource: Nursing databases was performed without limitation on publication year. Inclusion criteria were (1) reporting of outcomes after a (2) lower extremity injury in (3) elite soccer players. The study's population, type of injury, return to play, as well as functional, objective, and sport-specific performance-based outcomes were extracted from each article. The methodological index for nonrandomized studies was used for quality assessment., Results: Twenty-one studies were selected after application of the inclusion and exclusion criteria. Objective outcomes were reported by 6 (29%) studies, and 6 (29%) employed patient-reported outcomes. The visual analog scale, Lysholm, and Tegner scores were the most common patient-reported outcomes (PROs). Return to play was reported by 18 (86%) studies, and only 2 (10%) utilized sport-specific performance-based outcomes. Despite the majority of studies reporting return to play, variation was seen in the definitions, and 15 (71%) studies reported the activity level of the players at final follow-up., Conclusion: Assessment of treatment efficacy is limited in elite athletes, and PROs lack the sensitivity to identify residual performance deficits after an injury. Although performance-based measures are available at the elite level, these outcomes were seldom used for evaluation of treatment efficacy., Clinical Relevance: When treating elite soccer players, patient-reported outcome measures lack the sensitivity to detect changes in patient function, thus performance-based metrics may be more efficacious in assessing return from injury in these patients., Level of Evidence: IV.

Purpose: The purpose of this study is to systematically review the literature to evaluate the reliability, or the ability of a repeated measurement to yield consistent results, and validity of ultrasound (US) and magnetic resonance imaging (MRI) at evaluating anatomy and pathology of the anterolateral ligament of the knee (ALL) in the setting of anterior cruciate ligament (ACL) injuries. Furthermore, the incidence and association of ALL injury with the pivot-shift examination, and other structural injuries, will be reviewed for additional clinical relevance., Methods: Adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, 2 reviewers independently searched the Medline, Embase, Cochrane, EBSCOhost, OVID, and Web of Science databases for all studies related to imaging of the ALL. All eligible articles and their references were screened by both reviewers. Studies discussing diagnostic imaging of the ALL with regard to identification of injury to the structure in patients with suspected ACL injury were included. No restrictions regarding date of publication, type of publication, or language in the included article were applied. The exclusion criteria included commentaries, case reports, and studies that did not attempt to identify the ALL as a discrete structure. Quality assessment and data extraction was performed for each included study before final analysis was performed., Results: A total of 13 articles were included for final analysis. In the included studies, at least 1 portion of the ALL could be visualized on MRI in 76% to 100% of knees, and injury to the ALL was identified in 10.8% to 62.5% of patients. Inter- and intraobserver reliabilities ranged from moderate to almost perfect. There was a consensus among studies that ALL injuries were significantly associated with injuries to the lateral collateral ligament, popliteus tendon, iliotibial band, and bony contusions to the lateral tibia and femur. Most of the included studies found a significant association of injuries to the ALL and a high-grade pivot-shift examination. Only 2 studies used US to evaluate for injury to the ALL, and both studies had almost perfect interobserver reliability. Only 1 study confirmed initial diagnoses at the time of the ACL reconstruction surgery., Conclusions: In patients with ACL injuries, concomitant ALL injuries can be identified on MRI or US with high levels of inter- and intraobserver reliability, and are often associated with a high-grade pivot-shift examination, lateral collateral ligament injury, and lateral femoral condyle and tibial plateau bone bruises., Level of Evidence: Level IV, systematic review of level II-IV studies., (Copyright © 2018 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: The purpose of this study was to (1) map the length changes of the medial wall of the lateral femoral condyle (MWLFC) with respect to various points about the tibial anterior cruciate ligament (ACL) footprint to determine the area that demonstrates the least amount of length change through full range of motion and (2) to identify a range of flexion that would be favorable for graft tensioning., Methods: Six fresh-frozen cadaveric knees were obtained from screened individuals with no prior history of arthritis, cancer, surgery, or any ligamentous knee injury. For each knee, 3-dimensional computed tomography point-cloud models were obtained in succession from 0° to 135°. A point grid was placed on the MWLFC and the tibia. Intra-articular length was calculated for each point on the femur to the tibia at all flexion angles and grouped to represent areas for bone tunnels. Normalized length changes were compared., Results: Areas anterior/distal on the MWLFC increased with increasing flexion, and areas proximal/posterior decreased with increasing flexion. The area about the intersection of the lateral intercondylar ridge and the bifurcate ridge was most isometric throughout flexion as no significant change in ligament length was found throughout flexion. The normalized length changes from the central position of the tibia showed no significant difference compared with the anterior or posterior tibial position., Conclusions: No area of the MWLFC is truly isometric through flexion. Femoral tunnel placement slightly anterior to the center of the anteromedial and posterolateral bundles was most isometric. Minimal length change occurs between 10° and 40°, which reflects the range where graft tensioning was most often performed. The results of this study provide further support for an anatomic ACL reconstruction. CLINICAL RELEVANCE: The femoral tunnel location for ACL reconstruction with the least amount of length change through range of motion should encompass the direct fibers of the ACL., (Copyright © 2018 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

There are many methods for long head of the biceps tendon (LHBT) tenodesis, but a consensus on a superior method has yet to be met. In this article, we introduce a method for arthroscopic suprapectoral biceps tenodesis using a tenodesis screw in the bicipital tunnel. The intra-articular portion of the biceps tendon is transected. The subdeltoid space is then viewed via a lateral portal, and the tendon is mobilized from the bicipital tunnel. The tendon is retrieved through the anterior portal, and 5 whipstitch passes and a second distal stitch are placed. Three of the suture tails are passed through the tenodesis screwdriver, and the tendon is maneuvered to the previously reamed bone socket located 1.5 cm superior to the pec tendon, just inferior to the bicipital groove. Once the tenodesis screw is fixated in sufficient bone stock, 5 alternating half hitches reinforce the construct by creating a closed loop through the screw. This described technique allows full visualization of the LHBT dissection and tenodesis throughout the procedure. Additionally, this technique provides a method to incorporate whipstitching with an arthroscopic tenodesis screw to provide additional strength to tendon fixation.

Background: As health care transitions from a pay-for-service to a pay-for-performance infrastructure, the value of orthopaedic care must be defined accurately. Significant efforts have been made in defining quality and cost in arthroplasty; however, there remains a lag in ambulatory orthopaedic care., Purpose: Two-year follow-up has been a general requirement for reporting outcomes after rotator cuff repair. However, this time requirement has not been established scientifically and is of increasing importance in the era of value-based health care. Given that arthroscopic rotator cuff repair is a common ambulatory orthopaedic procedure, the purpose of this study was to establish a time frame for maximal medical improvement (the state when improvement has stabilized) after arthroscopic rotator cuff repair., Study Design: Systematic review., Methods: A systematic review of the literature was conducted, identifying studies reporting sequential patient-reported outcomes up to a minimum of 2 years after arthroscopic rotator cuff repair. The primary clinical outcome was patient-reported outcomes at 3-month, 6-month, 1-year, and 2-year follow-up. Secondary clinical outcomes included range of motion, strength, retears, and complications. Clinically significant improvement was determined between various time intervals by use of the minimal clinically important difference., Results: The review included 19 studies including 1370 patients who underwent rotator cuff repair. Clinically significant improvement in patient-reported outcomes was seen up to 1 year after rotator cuff repair, but no clinical significance was noted from 1 year to 2 years. The majority of improvement in strength and range of motion was seen up to 6 months, but no clinically meaningful improvement was seen thereafter. All reported complications and the majority of retears occurred within 6 months after rotator cuff repair., Conclusion: After rotator cuff repair, a clinically significant improvement in patient-reported outcomes, range of motion, and strength was seen up to 1 year after surgery, but not beyond this. This information is important not only to establish appropriate patient expectations but also to determine a time frame for outcome collection after surgery to better define value in orthopaedic care.

Purpose: To quantify the torsional load to fracture for subpectoral biceps tenodesis with interference screw fixation., Methods: We randomized 28 specimens from 14 matched-pair full-length humeri (mean age, 55.3 years) into 3 groups: (1) empty ream group (ERG), (2) screw-only group (SOG), and (3) screw-plus-biceps tendon group (SBG). In each group, 1 humerus of each matched pair was prepared according to group allocation and the contralateral humerus remained intact as a control. In the ERG, an 8-mm unicortical hole was reamed 1 cm proximal to the inferior border of the pectoralis major tendon insertion; in the SOG, the humerus was filled with an 8-mm × 12-mm PEEK (polyether ether ketone) screw; and in the SBG, the humerus was filled with a PEEK screw and the cadaveric long head of the biceps tendon. Humeri were tested under torsional displacement at a rate of 1°/s until fracture. Maximum torque, energy to maximum torque, and linear stiffness were used to assess humerus strength., Results: Compared with contralateral intact specimens, the maximum torque to fracture was reduced by 28% in the ERG (P = .005), 30% in the SOG (P = .014), and 20% in the SBG (P = .046). Energy to maximum torque was similarly reduced in the ERG (P = .007), SOG (P = .023), and SBG (P = .049). Stiffness was increased by 4% in the ERG (P = .498), 9% in the SOG (P = .030), and 4% in the SBG (P = .439)., Conclusions: Drilling an 8-mm unicortical hole in zone 3 of the bicipital tunnel for open subpectoral biceps tenodesis reduces the torsional load to humeral fracture up to 28% at time 0. The addition of a PEEK tenodesis screw alone reduced the maximum torque by 30%, and the addition of a screw with the long head of the biceps tendon reduced the maximum torque by 20%. The total load to fracture was reduced in all settings. Stiffness was not significantly different for the ERG and SBG, but stiffness was significantly higher for the SOG compared with the intact matched humeri at time 0., Clinical Relevance: When performing a biceps tenodesis, humeral fracture susceptibility is increased with an applied torsional load at time 0. Thus providers must be aware of this reduced integrity when a subpectoral biceps tenodesis is used., (Copyright © 2017. Published by Elsevier Inc.)

Background: There is increasing interest in outpatient shoulder arthroplasty (SA); however, the clinical evidence behind this practice is sparse. The purpose of this study was to assess the safety of outpatient SA performed in an ambulatory surgery center and to determine patient factors that are associated with increased risk for perioperative complications or dissatisfaction., Methods: Patient demographics and operative variables were collected retrospectively for patients undergoing outpatient SA at 2 ambulatory surgery centers with a minimum follow-up of 90 days. Patients completed a postsurgery questionnaire about their experience, satisfaction, pain control, and health care use., Results: Forty-one anatomic total SAs (n = 32) and reverse SAs (n = 9) with a mean follow-up of 60 weeks (16.4 weeks-3 years) were included. The mean age, body mass index, Charlson Comorbidity Index, and American Society of Anesthesiologists class were 60.6 ± 4.8 years, 31.8 ± 6.6, 2.9 ± 1.9, and 2.3 ± 0.6, respectively. Three (7.3%) minor complications occurred within 90 days of the SA, none before first follow-up. Two patients stayed in the ambulatory surgery center 23-hour observation unit. Thirty-five patients (85.4%) completed the questionnaire, of whom 97.0% (n = 32) were satisfied with the outpatient procedure. Two patients had difficulties with postoperative pain control and were taking chronic narcotic medication before surgery., Conclusion: Outpatient SA in an ambulatory surgery center is safe with high patient satisfaction and low rates of perioperative complications. Although larger cohorts are required to adequately determine which patients will be appropriate candidates for an outpatient SA, our findings do suggest that patients with a history of preoperative narcotic use may have difficulties or dissatisfaction with outpatient SA.

Background: The aims of the study were as follows: to perform a systematic review of meta-analyses comparing "early motion" and "delayed motion" after arthroscopic rotator cuff repair; to provide a framework to analyze the best available evidence to develop recommendations; and to identify gaps where suggestions could be made for future investigations., Methods: Literature searches were performed to identify meta-analyses examining arthroscopic rotator cuff repair with early-motion vs. delayed-motion rehabilitation protocols. Clinical data were extracted, and meta-analysis quality was assessed using the Quality of Reporting of Meta-analyses and Oxman-Guyatt scales., Results: Nine meta-analyses met inclusion criteria. No clear superiority was noted in clinical outcome scores for early-motion or delayed-motion rehabilitation. Results of tendon healing were found to be either no different or in favor of delayed motion, but no differences were noted in rotator cuff tear recurrence rates postoperatively. The majority of meta-analyses found significantly better range of motion with early motion up to a year postoperatively for forward elevation and up to 6 months for external rotation, but significant differences were not reported for functional improvements and strength at 12 months postoperatively. Subgroup analyses suggested that larger preoperative tear sizes have significantly greater retear rates with early-motion rehabilitation., Conclusions: The current highest level of evidence suggests that early-motion rehabilitation after rotator cuff repair results in superior postoperative range of motion up to 1 year. Whereas early motion and delayed motion after cuff repair may lead to comparable functional outcomes and retear rates, concern exists that early motion may result in greater retear rates, particularly with larger tear sizes., (Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Preservation of the meniscus has been shown to influence the progression of degenerative changes of the knee. As more meniscus is preserved, the propensity for development of osteoarthritis is lessened. Surgical treatment of a torn discoid meniscus has typically been a subtotal meniscectomy or partial meniscectomy. Similar to tears of a normal meniscus, partial meniscectomy compared with subtotal meniscectomy of the discoid meniscus confers better long-term results. With the abnormal morphology predisposing the discoid meniscus to tearing, several characteristic tear patterns can be observed-the horizontal tear being commonly encountered. We present a technique that not only creates a more normal morphology of a discoid meniscus but also preserves the tissue by using an all-inside, intrameniscal repair technique. This technique restores the central rim of the meniscus in the setting of a horizontal cleavage plane, thus restoring a more normal meniscus morphology.

Injuries to the glenoid labrum can result in shoulder instability and pain. These lesions may occur anywhere around the glenoid labrum, and thus, the arthroscopist must be prepared to approach all aspects of the glenoid from multiple angles. The pan-labral or circumferential (360°) tear of the glenoid labrum presents a unique challenge to even the experienced arthroscopist. The extent of the lesion requires the use of accessory portals and percutaneous techniques to establish adequate visualization and to facilitate the proper trajectory for anchor placement. The pan-labral tear also demands intraoperative planning throughout the repair to ensure proper tensioning and alignment of the labrum and capsular tissue. The purposes of this article are to report a technique for repairing a pan-labral lesion and to emphasize the use of accessory portals and percutaneous techniques for complete access to the glenoid.

Given the prevalence of anterior cruciate ligament (ACL) tears in young athletes, it is essential to elucidate and illustrate surgical interventions that return the most favorable outcomes. Although most ACL injuries are full-thickness tears, occasionally either the anteromedial (AM) or posterolateral (PL) bundle is torn in isolation, allowing consideration of an ACL reconstruction or augmentation. Because the ACL-deficient knee has been shown to exhibit less proprioceptive feedback, the preservation of the intact bundle may offer an inherent component of stability. After arthroscopy has confirmed a partial ACL tear, the decision to augment the intact bundle can be made. The technique is adapted from principles of the double-bundle reconstruction such that the graft follows the path of either the native AM bundle or the native PL bundle, depending on the location of the partial tear. We present our surgical technique for ACL AM bundle augmentation with PL bundle reconstruction using a semitendinosus tendon autograft.

Purpose: To use 3-dimensional custom CAD technology to evaluate how knee flexion angle affects femoral tunnel length and distance to the posterior wall when using curved and straight guides for drilling through the anteromedial portal (AMP)., Methods: Six cadaveric knees were placed in an external fixator at various degrees of flexion (90°, 110°, 125°, and maximum 135° to 140°). Computed tomography scans were obtained at all flexion points for 3-dimensional point-cloud models. Using custom CAD software, surgical guides through the AMP were replicated along with virtual tunnels at each flexion angle. Distance from the posterior cortex and tunnel dimensions were collected after 8-mm and 10-mm tunnel creation., Results: At 90° of flexion, the average tunnel length down the posterior aspect of 8-mm tunnel was 25.0 mm (95% confidence interval [CI] 16.2-33.8) and 12.0 mm (95% CI 7.3-16.7) for curved and straight guides, respectively; 31.0 mm (95% CI 26.8-35.2) and 28.6 mm (95% CI 24.8-32.4) at 110°; 33.8 mm (95% CI 30.1-37.5) and 31.1 mm (95% CI 26.8-35.4) at 125°; and 35.0 mm (95% CI 34.1-35.9) and 35.5 mm (95% CI 34.2-36.8) with maximal flexion. Values between curved and straight guides are significantly different (P < .001), with straight guides breaching the posterior wall at 90° and 110° of flexion in some specimens. The average distance to the posterior wall cortex was 0.9 mm (95% CI -1.5 to 3.3) and -0.6 mm (95% CI -2.3 to 1.1) for curved and straight guides, respectively, at 90° of flexion (P = .014); 2.3 mm (95% CI -0.2 to 4.8) and -0.1 mm (95% CI -2.4 to 2.2) at 110° (P = .001); 4.4 mm (95% CI 2.8-6.0) and 3.9 mm (95% CI 1.9-5.9) at 125° (P = .299); and 6.7 mm (95% CI 6.2-7.2) and 8.3 mm (95% CI 6.1-10.5) at maximal flexion (P = .184). Posterior wall blowout was noted when using 10-mm straight guides at both 90° (2 specimens) and 110° (3 specimens). Using 10-mm curved guides posterior blowout was noted in 1 specimen at 90°. Maximum footprint coverage occurred at 110° for straight guides and 90° for curved guides., Conclusions: When using the AMP, flexible guides and reamers result in a greater distance of the tunnel to the femoral cortex while preserving adequate tunnel length at lower knee flexion angles. To create long femoral tunnels without breaching the posterior cortex, the knee should be flexed to at least 110° for curved reamers and 125° for straight., Clinical Relevance: Femoral tunnel drilling through the AMP using curved and straight reamers requires different degrees of knee flexion to achieve optimal tunnel dimensions., (Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)