Tunnel Drilling Research Articles

Evaluation of the Ecological Risk for the Tunnel Drilling Waste of Tehran-Shomal Highway on Chaloos River

Evaluation of the Ecological Risk for the Tunnel Drilling Waste of Tehran-Shomal Highway on Chaloos River

The anatomical relationship of the common peroneal nerve to the proximal fibula and its clinical significance when performing fibular-based posterolateral reconstructions.

The common peroneal nerve (CPN) can be injured during fibular-based posterolateral reconstructions due to its close relationship to the neck of the fibula. Therefore, the purpose of this study was to observe the course of the CPN and its branches around the fibular head and neck and quantify the position in relation to relevant bony landmarks and observe the relation between tunnel drilling for posterolateral corner reconstruction and both the tunnel entry and exit at the proximal fibula and the CPN and its branches was observed. In 101 (mean age = 70.6 ± 16years) embalmed cadaver knees, the relationship between bony landmarks (tibial tuberosity, styloid process of fibula (APR)) and the CPN and its branches were established and 8 (M1-M8) distances from these landmarks measured; mean, SD and 95% CI were recorded. In 21 of these knees, a fibula tunnel was drilled as in PLC reconstruction and the association of the CPN and its branches to the tunnel entry and exit were judged by two independent observers. Fisher's exact test of independence was used to determine significant differences between genders. Tunnel intersection was analysed in a binary yes/no fashion and was described in frequencies and percentages. The mean distance from the APR to where the CPN reaches the fibula neck (M1) was 31.4 ± 8.9mm (CI:29.8-33.0); from the apex of the styloid process (APR) to where the CPN passes posterior to the broadest point of the fibular head (M3) was 21.7 ± 12.6mm (CI:19.4-24.0); from the apex of the APR to the most proximal point of the CPN/CPN first branch in the midline of the fibular head (M2) was 37.0 ± 6.7mm (CI: 35.4-37.7). Out of the 21 randomly selected knees for drilling, the first branch of the CPN was damaged at the tunnel entry point in 7 (33%), and in 5 knees (24%), the CPN was damaged at the tunnel exit. In one knee, at both the tunnel entry and exit, the first branch of the CPN and the CPN were intersected, respectively. The results of this study strongly suggest that the CPN is at risk when drilling the fibula tunnel performing fibula-based posterolateral corner reconstructions. The total injury rate was 57% with a 33% incidence of injury to the first branch of the nerve at the tunnel entry and 24% to the CPN at the tunnel exit. Due to the high incidence of injury, percutaneous placement of guide pins and tunnel drilling is not recommended. The nerve should be visualized and protected by either a traditional open approach or minimally invasive techniques. With a minimally invasive approach, the nerve should be identified at the fibula neck and then followed ante- and retrograde.

Mechanical Chuck Design and Slip Strength Analysis

Chuck is one of the key parts of coal mine tunnel drill, its performance directly affects the performance of the machine. In view of the existing problems of the hydraulic chuck, the structure of the new hydraulic chuck is designed and its working principle is briefly described. The strength of slips is analyzed by finite element method. The calculation results show that the initial design of slips meets the requirements of tunnel drilling rigs.

Safe Femoral Fixation Depth and Orientation for Lateral Extra-Articular Tenodesis in Anterior Cruciate Ligament Reconstruction.

Background:Patients who undergo anterior cruciate ligament (ACL) reconstruction (ACLR) can have a persistent postoperative pivot shift. Performing lateral extra-articular tenodesis (LET) concurrently has been proposed to address this; however, LET femoral fixation may interfere with the ACLR femoral tunnel, which could damage the ACL graft or its fixation.Purpose:To evaluate the safe maximum implant or tunnel depth for a modified Lemaire LET when combined with ACLR anteromedial portal femoral tunnel drilling and to validate the safe LET drilling angles to avoid conflict with the ACLR femoral tunnel.Study Design:Descriptive laboratory study.Methods:Twelve fresh-frozen cadaveric knees were used. With each knee at 120° of flexion, an ACLR femoral tunnel in the anteromedial bundle position was created arthroscopically via the anteromedial portal using a 5-mm offset guide, a guide wire, and an 8-mm reamer, which was left in situ. A modified Lemaire LET was performed using a 1 cm-wide iliotibial band strip harvested with the distal attachment intact, to be fixed in the femur. The desired LET fixation point was identified with an external aperture 10 mm proximal and 5 mm posterior to the fibular collateral ligament’s femoral attachment, and a 2.4-mm guide wire was drilled, aiming at 0°, 10°, 20°, or 30° anteriorly in the axial plane and at 0°, 10°, or 20° proximally in the coronal plane (12 different drilling angle combinations). The relationship between the LET drilling guide wire and the ACLR femoral tunnel reamer was recorded for each combination. When a collision with the femoral tunnel was recorded, the LET wire depth was measured.Results:Collision with the ACLR femoral tunnel occurred at a mean LET wire depth of 23.6 mm (range, 15-33 mm). No correlation existed between LET wire depth and LET drilling orientation (r = 0.066; P = .67). Drilling angle in the axial plane was significantly associated with the occurrence of tunnel conflict (P < .001). However, no such association was detected when comparing the drilling angle in the coronal plane (P = .267).Conclusion:Conflict of LET femoral fixation with the ACLR femoral tunnel using anteromedial portal drilling occurred at a mean depth of 23.6 mm but also at a depth as little as 15 mm, which is shorter than most implants. When longer implants or tunnels are used, the orientation should be directed at least 30° anteriorly in the axial plane to minimize the risk of tunnel conflict, bearing in mind the risk of joint violation.Clinical Relevance:This study provides important information for surgeons performing LET in combination with ACLR anteromedial portal femoral tunnel drilling regarding safe femoral implant or tunnel length and orientation.

A modified rock mass classification system for TBM tunnels and tunneling based on the HC method of China

The rock mass classification methods developed to evaluate rock mass stability and tunnel support design for blast and drill tunnels are not suitable to guide tunneling by tunnel boring machine (TBM), such as selection of TBM types, determination of construction scheme and so on. By comprehensively considering the rock mass boreability and stability, a modified rock mass classification system for TBM tunnels is proposed on the basis of the hydropower rock mass classification (HC) method of China. The input parameters are five rock mass parameters as the same as the HC method. In addition, the tunnel diameter is needed to estimate the TBM advance rate. The structure and parameter determination of the classification system are explained and statistically analyzed in details. This system can be applied to evaluate the feasibility of TBM construction and serve as the basis for selection of TBM types and design parameters in the pre-construction phase. Furthermore, it can also be applied to estimate TBM performance and guide tunnel support for a given ground condition in the design phase, and to optimize TBM operational parameters during the construction phase as well. An example is presented to illustrate the application of the proposed system. The limitations of the proposed system and further studies are also discussed.

The Statistical Fragility of Hamstring Versus Patellar Tendon Autografts for Anterior Cruciate Ligament Reconstruction: A Systematic Review of Comparative Studies

Background: Evidence-based medicine utilizes data to inform clinical decision making, despite the ability of a small number of outcome reversals to change statistical significance. P values are common measurements of statistical significance that possess inherent flaws. The inclusion of the fragility index (FI) and fragility quotient (FQ) may provide a clearer conveyance of statistical strength. Purpose/Hypothesis: The purpose was to examine the statistical stability of studies comparing hamstring tendon and bone–patellar tendon–bone autografts in primary single-bundle anterior cruciate ligament reconstruction with independent tunnel drilling. We hypothesized that the findings of these studies are vulnerable to a small number of outcome event reversals, often fewer than the number of patients lost to follow-up. Study Design: Systematic review. Methods: Comparative studies and randomized controlled trials (RCTs) published in 10 leading orthopaedic journals between 2000 and 2020 were analyzed. Statistical significance was defined as a P value ≤.05. FI for each outcome was determined by the number of event reversals necessary to alter significance. FQ was calculated by dividing the FI by the respective sample size. Results: Of the 1803 studies screened, 643 met initial search criteria, with 18 comparative studies ultimately included for analysis, 8 of which were RCTs. A total of 114 outcomes were examined. Overall, the mean (interquartile range) FI and FQ were 3.77 (2-4) and 0.040 (0.016-0.055), respectively. The FI was less than the number of patients lost to follow-up for 76.3% of outcomes. Conclusion: Studies examining graft choice for anterior cruciate ligament reconstruction may not be as statistically stable as previously thought. Comparative studies and RCTs are at substantial risk for statistical fragility, with few event reversals required to alter significance. The reversal of <4 outcome events in a treatment group can alter the statistical significance of a given result; this is commonly fewer than the number of patients lost to follow-up. Future comparative study analyses might consider including FI and FQ with P values in their statistical analysis.

Arthroscopic Coracoclavicular Ligament Stabilization Using Coracoid Cortical Suspension in Acute Acromioclavicular Joint Injury; Precision of Drill Tunnel

Acute acromioclavicular joint separation is a common injury of the shoulder. There are several methods for treating this condition; however, there is no gold standard established. Herein, we propose an arthroscopic method for the treatment of acute acromioclavicular joint separation using a simple cortical suspension device at the coracoid base via a transclavicular–transcoracoidal tunnel and tieing the suture at the clavicle. This method has the advantages of making a precision drilling tunnel using small implants and small stab incisions, with better cosmetic results and less implant irritation.

Remnant-Preserving Anterior Cruciate Ligament Reconstruction: Remnant Envelope Technique

The awareness of anterior cruciate ligament (ACL) injuries and their treatment is increasing among athletes and within the general population, so patients report early to orthopaedic surgeons. Because we encounter a thick ACL stump during arthroscopic ACL reconstruction, an attempt is made to preserve this stump. Remnant preservation—although promising in terms of graft healing because it enhances cell proliferation, revascularization, and regeneration of the proprioceptive organs in the reconstructed ACL—does not come without complications, such as cyclops lesions, impingement, and extension loss. These problems can be detrimental to an athlete's return to his or her preinjury level after ACL reconstruction. Therefore, we describe a technique in which the ACL is reconstructed using hamstring autograft and suture passes are made through the remnant with an antegrade suture-passing device. After anatomic tunnel drilling, the remnant is tensioned, along with the reconstructed ACL, at the femoral end without the use of an extra implant. Femoral-side fixation is achieved with an adjustable-loop button (Procinch; Stryker) and a bio-composite interference screw (Biosure Regenesorb; Smith & Nephew) on the tibial end. As the sutured remnant is tensioned and knots are made over the button, the remnant envelopes the graft in the orientation of the native ACL, which can be helpful for early and better ligamentization of the graft. The potential advantages of this technique are as follows: orientation of the remnant along the collagen of the ACL graft; no loose ACL stump in the notch, thus preventing cyclops lesions; retention of the proprioceptive organs in the ligament; and no extra implant.

A Hybrid Transtibial Technique Combines the Advantages of Anteromedial Portal and Transtibial Approaches: A Prospective Randomized Controlled Trial

Background: The anteromedial (AM) portal and transtibial (TT) approaches are 2 common anterior cruciate ligament (ACL) femoral tunnel drilling techniques, each with unique benefits and disadvantages. A hybrid TT (HTT) technique using medial portal guidance of a flexible TT guide wire has recently been described that may combine the strengths of both the AM portal and the TT approaches. Hypothesis: The HTT technique will achieve anatomic femoral tunnel apertures similar to the AM portal technique, with improved femoral tunnel length and orientation. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: A total of 30 consecutive patients with primary ACL tears were randomized to undergo the TT, AM portal, or HTT technique for femoral tunnel positioning at the time of reconstruction. All patients underwent 3-dimensional computed tomography of the operative knee at 6 weeks postoperatively. Femoral and tibial tunnel aperture positions and tunnel lengths, as well as graft bending angles in the sagittal and coronal planes, were measured. Results: Tibial tunnel lengths and aperture positions were identical between the 3 groups. The AM portal and HTT techniques achieved identical femoral aperture positions in regard to both height (P = .629) and depth (P = .582). By contrast, compared with the AM portal and HTT techniques, femoral apertures created with the TT technique were significantly higher (P < .001 and P < .001, respectively) and shallower (P = .014 and P = .022, respectively) in the notch. The mean femoral tunnel length varied significantly between the groups, measuring 35.2, 41.6, and 54.1 mm for the AM portal, HTT, and TT groups, respectively (P < .001). Last, there was no difference between the mean coronal (P = .190) and sagittal (P = .358) graft bending angles between the TT and HTT groups. By contrast, compared with the TT and HTT techniques, femoral tunnels created with the AM portal technique were significantly more angulated in the coronal plane (17.7° [P < .001] and 12.5° [P = .006], respectively) and sagittal plane (13.5° [P < .001] and 10.5° [P = .013], respectively). Conclusion: This prospective randomized controlled trial found that the HTT technique achieved femoral aperture positions equally as anatomic as the AM portal technique but produced longer, less angulated femoral tunnels, which may help reduce graft strain and mismatch. As such, this hybrid approach may represent a beneficial combination of both the TT and the AM portal techniques. Registration: NCT02795247 (ClinicalTrials.gov identifier)

Transphyseal Anterior Cruciate Ligament Reconstruction Using Hybrid Transtibial Femoral Drilling and a Quadriceps Tendon Autograft

Significant controversy exists regarding the optimal surgical technique for anterior cruciate ligament (ACL) reconstruction in adolescents with 1 to 3 years of skeletal growth remaining. Graft choice and physeal injury remain primary concerns given significantly elevated rates of failure of hamstring autograft reconstructions in this population, as well as risks of leg-length discrepancy and growth axis deviation. Traditional (more vertical) transtibial drilling of the femoral tunnel can reduce risks of physeal injury but has been shown to have less accuracy restoring the native femoral ACL footprint and associated incomplete knee stabilization. On the other hand, anteromedial and outside-in drilling yields improvements in the tunnel location and biomechanics but at the cost of a more oblique trajectory and greater risk of physeal injury. A hybrid transtibial pin technique using a Pathfinder guide facilitates femoral drilling with the “best of both worlds,” allowing for reproduction of the native ACL footprint and a more physeal-respecting femoral tunnel. When combined with an all–soft tissue quadriceps tendon autograft and suspensory fixation, the hybrid transtibial method yields a reliable, safe, and robust construct with promising results for the young athlete. We describe our preferred graft harvest, tunnel drilling, and fixation techniques to minimize physeal risks and optimize outcomes.

A calcaneal tunnel for CFL reconstruction should be directed to the posterior inferior medial edge of the calcaneal tuberosity.

Anatomical reconstruction of the calcaneofibular ligament (CFL) is a common technique to treat chronic lateral ankle instability. A bone tunnel is used to fix the graft in the calcaneus. The purpose of this study is to provide some recommendations about tunnel entrance and tunnel direction based on anatomical landmarks. The study consisted of two parts. The first part assessed the lateral tunnel entrance for location and safety. The second part addressed the tunnel direction and safety upon exiting the calcaneum on the medial side. In the first part, 29 specimens were used to locate the anatomical insertion of the CFL based on the intersection of two lines related to the fibular axis and specific landmarks on the lateral malleolus. In the second part, 22 specimens were dissected to determine the position of the neurovascular structures at risk during tunnel drilling. Therefore, a method based on four imaginary squares using external anatomical landmarks was developed. For the tunnel entrance on the lateral side, the mean distance to the centre of the CFL footprint was 2.8 ± 3.0mm (0-10.4mm). The mean distance between both observers was 4.2 ± 3.2mm (0-10.3mm). The mean distance to the sural nerve was 1.4 ± 2mm (0-5.8mm). The mean distance to the peroneal tendons was 7.3 ± 3.1mm (1.2-12.4mm). For the tunnel exit on the medial side, the two anterior squares always contained the neurovascular bundle. A safe zone without important neurovascular structures was found and corresponded to the two posterior squares. Lateral landmarks enabled to locate the CFL footprint. Precautions should be taken to protect the nearby sural nerve. A safe zone on the medial side could be determined to guide safe tunnel direction. A calcaneal tunnel should be directed to the posterior inferior medial edge of the calcaneal tuberosity.

Hamstrings substitution via anteromedial portal with optional anterolateral ligament reconstruction is the preferred surgical technique for anterior cruciate ligament reconstruction: a survey among ESSKA members

The objective of this study was to report on a worldwide web-based survey among the ESSKA community developed to investigate current recommendations regarding ACL reconstruction surgical procedures. All contacts in the official mailing list of the ESSKA were contacted to investigate preferences regarding graft type, anterolateral ligament reconstruction, femoral tunnel drilling technique, single-bundle vs double-bundle technique, femoral and tibial fixation methods. Eight-hundred and twenty responses were analyzed. Hamstrings autograft was the graft of choice in male patients for 634 (79%) and in female patients for 674 (84%) responders, while its preference for ACL reconstruction in professional athletes was for 401 (50%). 480 (63%) surgeons surveyed would include anterolateral ligament reconstruction only if diagnosed and remaining instability after ACL surgery or revision. 598 (75%) respondents were in favor of anteromedial portal for femoral tunnel drilling. The most popular femoral fixation technique was found to be cortical suspension (500-66%), while a compression system was preferred on the tibial side by 537 (71% of the sample). This survey study found that HT autograft, single-bundle reconstruction, anteromedial portal for femoral tunnel drilling, cortical suspension systems for femoral fixation and compression systems for tibial fixation represent the current standard of ACLR in a large community of orthopedic surgeons. The present study performed with surgeons who are members of the ESSKA community will help to comprehend the actual ACLR worldwide practice patterns. Due to low response rate, these results should be interpreted with caution and not to be intended to represent the state of the art of ESSKA community. III.

Comparison of clinical results of anteromedial and transtibial femoral tunnel drilling in ACL reconstruction

BackgroundA femoral bone tunnel in ACL reconstruction can be constructed from the outside in or from the inside out. When doing it inside out, the approach can be via the anteromedial (AM) portal or through the tibial bone tunnel. It has been suggested that better results might be expected by doing it anteromedially. Clinical results after femoral tunnel drilling via the AM or transtibial (TT) techniques in reconstruction of anterior cruciate ligament (ACL) are presented.MethodsThree hundred patients with ACL injuries were chosen for this study from previously collected data on ACL reconstructions. They were divided into two groups: 150 patients treated with AM drilling and 150 treated with TT drilling. In the AM group, the reconstructions were performed using a semitendinosus graft with the Tape Locking Screw (TLS™) technique (n = 87) or Retrobutton™ femoral and BioScrew™ tibial fixation with a semitendinosus-gracilis graft (n = 63). In the TT group, the fixation method used was Rigidfix™ femoral and Intrafix tibial fixation with a semitendinosus-gracilis graft. The evaluation methods were clinical examination, knee scores (Lysholm, Tegner and IKDC) and instrumented laxity measurements (KT-2000™). Our aim was to evaluate if there was better rotational stability and therefore better clinical results when using AM drilling compared to TT drilling.ResultsAfter excluding revision ACL reconstructions, there were 132 patients in the AM group and 133 in the TT group for evaluation. At the 2-year follow-up, there were 60 patients in the AM group (45.5%) and 58 in the TT group (43.6%). There were no statistically significant differences between the groups in any of the evaluation methods used.ConclusionBoth drilling techniques resulted in improved patient performance and satisfaction. We found no data supporting the hypothesis that the AM drilling technique provides better rotational stability to the knee.Trial registrationISRCTN registry with study ID ISRCTN16407730. Retrospectively registered Jan 9th 2020.

Journey around the Notch: A Systematic Review on the History of ACL Reconstruction in the United States

The evolution of anterior cruciate ligament (ACL) surgery, seemingly circular at times, informs and provides context for past and current controversies in ACL management. The purpose of this systematic review is to objectively summarize the historical course of ACL reconstruction and repair in the United States over the last 40 years. Femoral tunnel drilling and graft selection have evolved dramatically over the last few decades. An initial focus on restoring ACL anatomy was for a period sacrificed for decreased operative morbidity. However, recent developments in operative techniques aim to restore ACL anatomy while also achieving minimal operative morbidity. Despite this historically iterative process, there remains no perfect choice for the treatment of ACL tears. Continued research on ACL repair, anatomic graft placement, graft choice, and augmentation will help our patients over the next generation.

Bone Tunnel Placement Determination Method for 3D Images and Its Evaluation for Anterior Cruciate Ligament Reconstruction.

Anterior cruciate ligament (ACL) injury causes knee instability which affects sports activity involving cutting and twisting motions. The ACL reconstruction surgery replaces the damaged ACL with artificial one which is fixed to the bone tunnels opened by the surgeon. The outcome of the ACL reconstruction is strongly related to the placement of the bone tunnels, therefore, the optimization of tunnel drilling technique is an important factor to obtain satisfactory surgical results. The quadrant method is used for the post-operative evaluation of the ACL reconstruction surgery, which evaluates the bone tunnel opening sites on the lateral 2D X-ray radiograph. For the purpose of applying the quadrant method to the pre-operative knee MRI, we have synthesized the pseudo lateral 2D X-ray radiograph from the patients' knee MRI. This paper proposes a computer-aided surgical planning system for the ACL reconstruction. The proposed system estimates appropriate bone tunnel opening sites on the pseudo lateral 2D X-ray radiograph synthesized from the pre-operative knee MRI. In the experiment, the proposed method was applied to 98 subjects including subjects with osteoarthritis. The experimental results showed that the proposed method can estimate the bone tunnel opening sites accurately. The other experiment using 36 healthy patients showed that the proposed method is robust to the knee shape deformation caused by disease. It is verified that the proposed method can be applied to subjects with osteoarthritis.

A new mini-open technique of arthroscopically assisted Latarjet

BackgroundThe aim is to describe a new arthroscopically assisted Latarjet technique.MethodsWe evaluated the clinical and radiological findings of 60 patients with chronic recurrent anterior gleno-humeral instability who underwent, between September 2013 and November 2014, an arthroscopically-assisted Latarjet procedure with double round endobutton fixation. Inclusion criteria were: chronic anterior recurrent instability, Instability Severity Index Score (ISIS) greater than three points, a glenoid bone defect > 15% or a Hill Sachs lesion with concomitant glenoid bone defect > 10%. During surgery the joint capsule and the anterior glenoid labrum were detached. Two drill tunnels perpendicular to the neck of the glenoid were made through a guide. An accessible pilot hole through the glenoid was created to allows the passage of guidewires for coracoid guidance and final fixation onto the anterior glenoid. Through a restricted deltopectoral access a coracoid osteotomy was made. Finally, the graft was prepared, inserted and secured using half-stitches.ResultsThe mean follow-up was 32.5 months (range 24–32 months). At a mean follow-up, 56 of the 60 subjects claimed a stable shoulder without postoperative complaints, two (3.3%) had an anterior dislocation after new traumatic injury, and two (3.3%) complained of subjective instability. At the latest follow-up, four subjects complained of painful recurrent anterior instability during abduction-external rotation with apprehension. At 1 year, the graft had migrated in one patient (1.7%) and judged not healed and high positioned in another patient (1.7%). Moreover, a glenoid bony gain of 26.3% was recorded. At the latest follow-up, three patients had grade 1 according to Samilson and Prieto classification asymptomatic degenerative changes. Nerve injuries and infections were not detected. None of the 60 patients underwent revision surgery. Healing rate of the graft was 96.7%.ConclusionsThis technique of arthroscopically assisted Latarjet combines mini-open and arthroscopic approach for improving the precision of the bony tunnels in the glenoid and coracoid placement, minimizing any potential risk of neurologic complications. It can be an option in subjects with anterior gleno-humeral instability and glenoid bone defect. Further studies should be performed to confirm our preliminary results.Trial registrationTrial registration number 61/int/2017Name of registry: ORSDate of registration 11.5.2017Date of enrolment of the first participant to the trial: September 2013 ‘retrospectively registered’Level of evidenceIV

Iatrogenic Injury to the Posterolateral Knee During Anterior Cruciate Ligament Reconstruction with Anteromedial Portal Technique

BACKGROUND: Femoral tunnel reaming through anteromedial portal, also known as transportal technique, allows for anatomic femoral tunnel placement in restoring anterior cruciate ligament (ACL) kinematics. This procedure may cause iatrogenic injury to the posterolateral structures of the knee.&#x0D; PURPOSE: This study aims to assess the risk of posterolateral structure injury in ACL reconstruction using transportal technique.&#x0D; METHODS: ACL reconstruction using transportal technique was performed in 20 patients. Clinical and radiological examination was performed preoperatively and 1 month postoperatively. Clinical examination included any pain or paresthesia on posterolateral area of the knee, varus alignment of the knee, abnormal gait, and specific tests for posterolateral stability. Radiological evaluation was plain radiography and stress radiography for posterolateral stability, and magnetic resonance imaging (MRI) for assessing structural damage.&#x0D; RESULTS: Post-operative evaluation showed pain in posterolateral area in five patients, numbness on posterolateral knee in one patient, both pain and numbness in two patients and lateral gastrocnemius muscle injury on MRI in six patients. We did not find varus knee alignment and abnormal gait. Specific tests were negative in post-operative evaluation. Post-operative radiographic imaging did not show the sign of lateral widening.&#x0D; CONCLUSION: Femoral tunnel drilling using transportal technique in ACL reconstruction is safe even it might risk to damage lateral gastrocnemius muscle, according to clinical and MRI findings.

Does Manual Drilling Improve the Healing of Bone-Hamstring Tendon Grafts in Anterior Cruciate Ligament Reconstruction? A Histological and Biomechanical Study in a Rabbit Model.

Background:Heat necrosis due to motorized drilling during anterior cruciate ligament (ACL) reconstruction could be a factor in delayed healing at the bone–tendon graft interface.Hypothesis:The process of osteointegration could be enhanced using manual drilling. It reduces the invasiveness of mechanical-thermal stress normally caused by the traditional motorized drill bit.Study Design:Controlled laboratory study.Methods:ACL reconstruction using semitendinosus tendon autografts was performed in 28 skeletally mature female New Zealand white rabbits, which were randomly divided into 3 groups. In group A (n = 12), the tunnels were drilled using a motorized device; in group B (n = 12), the tunnels were drilled using a manual drill bit; and group C (n = 4) served as a control with sham surgical procedures. The healing process in the tunnels was assessed histologically at 2, 4, 8, and 12 weeks and graded according to the Tendon–Bone Tunnel Healing (TBTH) scoring system. In addition, another 25 rabbits were used for biomechanical testing. The structural properties of the femur–ACL graft–tibia complex, from animals sacrificed at 8 weeks postoperatively, were determined using uniaxial tests. Stiffness (N/mm) and ultimate load to failure (N) were determined from the resulting load-elongation curves.Results:The time course investigation showed that manual drilling (group B) had a higher TBTH score and improved mechanical behavior, reflecting better organized collagen fiber continuity at the bone–fibrous tissue interface, better integration between the graft and bone, and early mineralized chondrocyte-like tissue formation at all the time points analyzed with a maximum difference at 4 weeks (TBTH score: 5.4 [group A] vs 12.3 [group B]; P < .001). Stiffness (23.1 ± 8.2 vs 17.8 ± 6.3 N/mm, respectively) and ultimate load to failure (91.8 ± 60.4 vs 55.0 ± 18.0 N, respectively) were significantly enhanced in the specimens treated with manual drilling compared with motorized drilling (P < .05 for both).Conclusion:The use of manual drilling during ACL reconstruction resulted in better tendon-to-bone healing during the crucial early weeks. Manual drilling was able to improve the biological and mechanical properties of bone–hamstring tendon graft healing and was able to restore postoperative graft function more quickly. Tunnel drilling results in bone loss and deficient tendon-bone healing, and heat necrosis after tunnel enlargement may cause mechanical stress, contributing to a delay in healing. Manual drilling preserved the bone stock inside the tunnel, reduced heat necrosis, and offered a better microenvironment for faster healing at the interface.Clinical Relevance:Based on study results, manual drilling could be used successfully in human ACL reconstruction, but further clinical studies are needed. A clinical alternative, called the original “all-inside” technique, has been developed for ACL reconstruction. In this technique, the femoral and tibial tunnels are manually drilled only halfway through the bone for graft fixation, reducing bone loss. Data from this study suggest that hamstring tendon–to–bone healing can be improved using a manual drilling technique to form femoral and tibial tunnels.

Revision Risk of Soft Tissue Allograft Versus Hybrid Graft After Anterior Cruciate Ligament Reconstruction

Background: When a harvested hamstring autograft is deemed by the surgeon to be of inadequate diameter, the options include using the small graft, using another autograft from a different site, augmenting with an allograft (hybrid graft), using a different configuration of the graft (eg, 5- or 6-stranded), or abandoning the autograft and using allograft alone. A small graft diameter is associated with a higher revision risk, and using another autograft site includes added harvest-site morbidity; therefore, use of a hybrid graft or an allograft alone may be appealing alternative options. Revision risk for hybrid graft compared with soft tissue allograft is not known. Purpose: To evaluate the risk for aseptic revision surgery after primary anterior cruciate ligament reconstruction (ACLR) using a soft tissue allograft compared with ACLR using a hybrid graft in patients 25 years and younger. Study Design: Cohort study; Level of evidence, 3. Methods: Data from a health care system’s ACLR registry were used to identify primary isolated unilateral ACLRs between 2009 and 2016 using either a hybrid graft (hamstring autograft with soft tissue allograft) or a soft tissue allograft alone. Multivariable Cox proportional hazards regression was used to evaluate risk for aseptic revision after ACLR according to graft used after adjustment for age, allograft processing, tunnel drilling technique, and region where the primary ACLR was performed. Results: The cohort included 2080 ACLR procedures; a hybrid graft was used for 479 (23.0%) ACLRs. Median follow-up time was 3.4 years (interquartile range, 1.8-5.1 years). The crude 2-year aseptic revision probability was 5.4% (95% CI, 4.3%-6.7%) for soft tissue allograft ACLR and 3.8% (95% CI, 2.3%-6.4%) for hybrid graft ACLR. After adjustment for covariates, soft tissue allograft ACLR had a higher risk of aseptic revision during follow-up compared with hybrid graft ACLR (hazard ratio, 2.00; 95% CI, 1.21-3.31; P = .007). Conclusion: Soft tissue allografts had a 2-fold higher risk of aseptic revision compared with hybrid graft after ACLR. Future studies evaluating the indications for using hybrid grafts and the optimal hybrid graft diameter is needed.

Revision Risk Of Soft Tissue Allograft Versus Hybrid Graft Following Anterior Cruciate Ligament Reconstruction

Objectives: Prior studies have found smaller hamstring autograft diameter to be associated with a higher revision risk following anterior cruciate ligament reconstruction (ACLR). Therefore, when a harvested hamstring autograft is deemed by the surgeon to be of inadequate diameter, the options include: using the small graft, using another autograft from a different site, augmenting with an allograft (hybrid graft), or abandoning the autograft and using allograft alone. Using another autograft site includes added harvest-site morbidity, therefore utilization of an allograft to augment the autograft (hybrid) or allograft alone may be an appealing alternative option. Revision risk for hybrid graft compared to soft tissue allograft in is not known. The purpose of our study was to determine the risk for aseptic revision following soft tissue allograft ACLR compared to hybrid graft ACLR in patients 25 years and younger. Methods: Data from a healthcare system’s ACLR registry was used to conduct a cohort study. Primary isolated unilateral ACLR from 2009-2016 using either a hybrid graft (hamstring autograft + soft tissue allograft) or soft tissue allograft alone were identified. Time-to-aseptic revision surgery following primary ACLR was the primary endpoint. Multivariable Cox proportional hazard regression was used to evaluate risk for aseptic revision according to graft utilization after adjustment for age, allograft processing, tunnel drilling technique, and region where the primary ACLR was performed. Analysis censored patients at the time lost to follow-up (healthcare plan termination or death) or the end of study follow-up. A sandwich covariance matrix estimator was used to account for clustering of ACLR at the surgeon level. Results: The cohort included 2080 ACLR performed by 161 surgeons at 42 healthcare centers. Soft tissue allograft was used for 1601 (77.0%) ACLR and hybrid graft for 478 (23.0%). For the soft tissue allograft ACLR group, mean age was 19.2 (standard deviation [SD]=3.5) years, 79.1% of allografts were irradiated or chemically processed, and 50.4% of femoral tunnels were through the trans-tibial technique. For the hybrid graft ACLR group, mean age was 18.4 (SD=3.3) years, 81.5% were irradiated or chemically processed, and 72.3% of femoral tunnels were through the trans-tibial technique. Median follow-up time was 3.4 years (interquartile range=1.8-5.1 years). The crude 2-year aseptic revision probability was 5.4% (95% confidence interval [CI]=4.3-6.7) for soft tissue allograft ACLR and 3.8% (95% CI=2.3-6.4) for hybrid ACLR. After adjustment for covariates, soft tissue allograft ACLR had a higher risk of aseptic revision during follow-up compared to hybrid graft ACLR (hazard ratio=2.00, 95% CI=1.21-3.31, p=0.007). Conclusion: Soft tissue allograft had twice the risk of aseptic revision compared to hybrid graft following ACLR. Based on our findings, when faced with a hamstring autograft that is deemed to have an inadequate diameter, augmenting it with allograft tendon may be preferred over abandoning it for an allograft alone. Future study evaluating the indications and the optimal hybrid graft diameter is needed.