Clinical and electrophysiological assessment of injury to infrapatellar branch(es) of saphenous nerve during anterior cruciate ligament reconstruction using oblique incision for hamstring graft harvest: A prospective study

BackgroundOne of the complications of arthroscopic reconstruction of anterior cruciate ligament (ACL) using hamstring autograft is injury to the infrapatellar branch of the saphenous nerve (IPBSN) leading to loss of sensation around the knee. Its incidence varies according to the orientation of incision for hamstring graft harvest, with oblique incision having the lowest chance of this injury. Aim of this study was to assess clinically and electrophysiologically injury to IPBSN after ACL reconstruction using oblique incision for hamstring graft harvest.MethodsFifty patients that were scheduled to undergo arthroscopic ACL reconstruction were included. All the patients were evaluated both clinically and electrophysiologically preoperatively and at three weeks and six months postoperatively to determine injury to IPBSN. Patient satisfaction after surgery was also compared.ResultsIPBSN injury was found to be present in 12 out of 50 patients (24%). Both clinical and electrophysiological data correlated completely. The difference in the length of the skin incisions between IPBSN injured and IPBSN intact patients was found to be statistically significant (P = .0043). The difference in the satisfaction score between patients with injured and intact IPBSN was also found to be statistically significant (P = .02).ConclusionsOblique incision for hamstring graft harvest results in lower incidence of IPBSN injury and subsequent sensory loss when compared with similar studies with different skin incisions carried out in the past. Patients undergoing ACL reconstruction should be counseled preoperatively regarding this potential complication, and if this complication occurs, improvement can be expected with time.     

Return to play in paediatric & adolescent patients following anterior cruciate ligament reconstruction

BackgroundThere is an increased risk of anterior cruciate ligament (ACL) rupture and subsequent ACL reconstruction in patients <18 years old due to their high levels of sporting participation.PurposeThe purpose of this study was to assess the rate and timing of return to play (RTP) in paediatric and adolescent patients following ACL reconstruction, and to compare the outcomes between those undergoing ACL reconstruction with bone patella tendon bone autograft (BTB) and hamstring tendon (HT) autograft.Study DesignLevel of Evidence: Level III; Retrospective Comparative Cohort Study.MethodsThe institutional ACL registry was screened for patients <18 that had undergone a primary ACL reconstruction. Outcomes were analysed for patients undergoing either a BTB or HT autograft for rate and timing of return to play, functional outcomes and subsequent knee injuries. Statistical analysis was performed using SPSS.Results358 (BTB; 253, HT; 105) patients were followed up for 24-months (95% follow up). 86 athletes (27 BTB; 59 HT) were aged 13–15 years old with no significant difference in RTP rate or timing between graft types, however, there was a difference in ipsilateral re-ruptures (10.2% HT vs 0% BTB p = 0.03). 272 athletes (226 BTB; 46 HT) were aged 16–18 years old with no significant difference in RTP rate or timing between graft types, or ipsilateral re-ruptures (8.7% HT vs 2.7% BTB p = 0.07). Concurrent ligament, meniscal or chondral injuries found at the time was treated as necessary.ConclusionPaediatric and adolescent patients undergoing ACL reconstruction with either BTB or HT had high rates of return to play. This was seen in both subgroups with 13–15-year-olds mostly receiving a HT graft repair and 16–18-year-olds mainly receiving a BTB repair. A moderate re-rupture rate was seen at 24-months. However longer follow up is needed to truly see the long-term impact of such an injury at such a young age.     

Anterior cruciate ligament graft forces are sensitive to fixation angle and tunnel position within the native femoral footprint during passive flexion

BackgroundAnterior cruciate ligament (ACL) graft position within the anatomic femoral footprint of the native ACL and the flexion angle at which the graft is fixed (i.e., fixation angle) are important considerations in ACL reconstruction surgery. However, their combined effect on ACL graft force remains less well understood.HypothesisDuring passive flexion, grafts placed high within the femoral footprint carry lower forces than grafts placed low within the femoral footprint (i.e., high and low grafts, respectively). Forces carried by high grafts are independent of fixation angle. All reconstructions impart higher forces on the graft than those carried by the native ACL.Study DesignControlled laboratory study.MethodsFive fresh-frozen cadaveric knees were mounted to a robotic manipulator and flexed from full extension to 90° of flexion. The ACL was sectioned and ACL force was calculated via superposition. ACL reconstructions were then performed using a patellar tendon autograft. For each knee, four different reconstruction permutations were tested: high and low femoral graft positions fixed at 15° and at 30° of flexion. Graft forces were calculated from full extension to 90° of flexion for each combination of femoral graft position and fixation angle again via superposition. Native ACL and ACL graft forces were compared through early flexion (by averaging tissue force from 0 to 30° of flexion) and in 5° increments from full extension to 90° of flexion.ResultsWhen fixed at 30° of flexion, high grafts carried less force than low grafts through early flexion bearing a respective 64 ± 19 N and 88 ± 11 N (p = 0.02). Increasing fixation angle from 15° to 30° caused graft forces through early flexion to increase 40 ± 13 N in low grafts and 23 ± 6 N in high grafts (p < 0.001). Low grafts fixed at 30° of flexion differed most from the native ACL, carrying 67 ± 9 N more force through early flexion (p < 0.001).ConclusionACL grafts placed high within the femoral footprint and fixed at a lower flexion angle carried less force through passive flexion compared to grafts placed lower within the femoral footprint and fixed at a higher flexion angle. At the prescribed pretensions, all grafts carried higher forces than the native ACL through passive flexion.Clinical RelevanceBoth fixation angle and femoral graft location within the anatomic ACL footprint influence graft forces and, therefore, should be considered when performing ACL reconstruction.     

The effects of initial graft tension on femorotibial relationship following anatomical rectangular tunnel anterior cruciate ligament reconstruction using bone–patellar tendon–bone graft

BackgroundThe purpose of this study was to elucidate the effects of the difference of initial graft tension on the femorotibial relationship on an axial plane and its chronological change following anatomical anterior cruciate ligament (ACL) reconstruction.MethodsA total of 63 patients who underwent anatomical ACL reconstruction were included in this study. The graft was fixed at full knee extension with manual maximum (higher graft tension; group H) and 80 N (lower graft tension; group L) pulls in 31 and 32 patients, respectively. The femorotibial positional relationship in axial computed tomography at 1 week and 1 year postoperatively were retrospectively evaluated. The side-to-side differences (SSDs) and the amount of changes of SSDs over 1 year were compared between groups.ResultsThe SSDs of the external rotational angle of the tibia in group H were significantly larger than those in group L at postoperative 1 week (2.7 ± 3.9° vs. 0.3 ± 3.3°; P < 0.01). The amount of internal rotational changes of SSDs of the internal–external rotational angles over 1 year in group H was significantly larger than that in group L (−3.6 ± 3.9° vs. − 0.3 ± 2.7°; P < 0.01). No significant differences were observed on the anterior–posterior translation distance and medial–lateral shift distance.ConclusionThe application of higher initial graft tension resulted in excessive external rotation of the tibia to the femur at 1 week postoperatively in anatomical ACL reconstruction, and the excessive early external tibial rotation had resolved over 1 year.     

Anatomy of the anterior cruciate ligament related to hamstring tendon grafts. A cadaveric study

BackgroundThe aim of modern techniques for anatomic reconstruction of the ACL is to reproduce ACL footprints, in order to restore anatomy and therefore normal biomechanics. Is there an oversizing of the hamstring grafts related to ACL dimensions?MethodsTwenty-two paired cadaver knees were dissected. ACL dimensions at mid-portion and ACL footprints were measured after removing the synovial membrane.Hamstrings were harvested and prepared in a quadruple strand graft in order to measure the mean circumference.ResultsThe average ACL tibial and femoral insertion site areas of the ACL were 117.9 mm² (range, 90 to 130 mm) and 96.8 mm² (range, 80 to 121 mm), respectively.The average diameter and cross sectional area of the ACL tendon at mid-portion were 6.1 mm (range, 5 to 7 mm) and 29.2 mm² (range, 20 to 38.9), respectively. The average diameter and cross-sectional area of the 4-stranded hamstring tendons were 6.7 (range, 5 to 8) and 35.3 mm² (range, 20 to 50), respectively.There was a correlation between the 4-stranded hamstring grafts and ACL dimensions (footprints, ligament at mid substance, p < 0.01). The cross sectional area of hamstring tendon was significantly larger than the ACL area at mid-portion (mean 20.9%, p < 0.05).ConclusionWith current ACL reconstruction techniques, the graft is oversized at a mean of 21%, despite a good correlation between the ACL and the hamstring tendon, especially among small subjects and women. The question arises whether the anatomic reconstruction of the ACL should fill ACL footprints or mimic the ligament itself.Clinical relevanceHamstrings grafts are significantly larger than native ACL.     

Quadriceps strength to body weight ratio is a significant indicator for initiating jogging after anterior cruciate ligament reconstruction

BackgroundQuadriceps strength recovery after anterior cruciate ligament (ACL) reconstruction is an important criterion for progress in rehabilitation and return to sports. The purpose of this study was to determine whether quadriceps strength to body weight ratio (QS/BW) is a significant indicator for initiating jogging after ACL reconstruction.MethodsIsokinetic quadriceps strength at 60°/s was measured and a jogging trial was completed 3 months after ACL reconstruction with hamstring tendon autograft in 83 patients (36 male, 47 female; mean age, 26.6 ± 12.4 years). Based on the jogging trial results, patients were assigned to either a successful jogging group (mean velocity ≥ 9 km/h) or an unsuccessful jogging group (mean velocity < 9 km/h). The association between QS/BW and successful jogging after surgery was investigated by multivariate logistic regression analysis and the cut-off value was determined by receiver operating characteristic analysis.ResultsForty-four patients (53.0%) were assigned to the successful jogging group and 39 (47.0%) to the unsuccessful jogging group. QS/BW was independently associated with initiating jogging 3 months after surgery. The cut-off value of QS/BW for successful jogging was 1.45 Nm/kg (area under the curve = 0.94; sensitivity = 88.6%, specificity = 87.2%). All of the patients who initiated jogging with QS/BW of > 1.45 Nm/kg at 3 months returned to sports without recurrence or contralateral injury by 10 months after surgery.ConclusionsQS/BW is a significant indicator for safely initiating jogging 3 months after ACL reconstruction. The cut-off value of QS/BW for initiating jogging was 1.45 Nm/kg.     

The architecture of the ipsilateral quadriceps two years after successful anterior cruciate ligament reconstruction with bone–patellar tendon–bone autograft

BackgroundWe undertook a cross-sectional study to evaluate the pennation angle and muscle thickness of the vastus lateralis muscle in patients undergoing unilateral anterior cruciate ligament (ACL) reconstruction with bone–patellar tendon–bone autograft, and compared these values with the contralateral non-operated limb.MethodsTwenty three consecutive athletic males who underwent ACL reconstruction using the central third of the patellar ligament were evaluated at 25.9 ± 1.5 months. The International Knee Documentation Committee (IKDC) score was administered, and angles of pennation and muscle thickness were measured by ultrasonography.ResultsThere was no significant difference in the pennation angle of the operated leg comparing to the contralateral leg (12.5° ± 1.81° in the operated leg; 13.25° ± 2.40° after the test; p = 0.117). Quadriceps thickness in the operated leg was significantly decreased in all subjects compared to the contralateral leg (28.4 ± 5.3 mm in the operated leg; 32.7 ± 4.85 mm in the contralateral leg; p = 0.007).ConclusionsTwo years after surgery, there is no difference in pennation angle of the vastus lateralis when compared to the contralateral side in patients undergoing unilateral ACL reconstruction with bone–patellar tendon–bone autograft. There is a significant difference in quadriceps muscle thickness, which was less in the operated side on the operated side in all patients. Further studies are required to study the influence of muscle architecture on clinical outcome after ACL reconstruction surgery, and whether there are differences associated with the use of different grafts.Level of evidenceCase–control study; level IV.     

Those with hemophilia or von Willebrand disease do not have increased perioperative complications following anterior cruciate ligament reconstruction: Results of a case-control large-database study

BackgroundThere is a lack of information on anterior cruciate ligament (ACL) reconstruction outcomes and complications for patients with congenital hypocoagulable conditions. The specific aim of this retrospective study was to report operative outcomes and complications for patients with congenital hypocoagulable disorders who underwent ACL reconstruction.MethodsWe performed a retrospective review of all patients who underwent an ACL reconstruction within Truven MarketScan Commercial Claims and Encounter Database from 2010 to 2014. Hemophilia A, hemophilia B and patients were identified. Patient demographics, cost of surgery, blood product use, concomitant injuries, repeat ACL injury, complications and various operative variables were collected. Statistical tests were conducted on SAS 9.4 2013.ResultsThirty-three hemophilia A, three hemophilia B, 63 von Willebrand factor patients, and 103,478 controls underwent ACL reconstruction. There is a statistically significant difference for hemarthrosis 1 year leading up to injury for hemophilia A compared with control (P = 0.0083). Total healthcare utilization 90 days after surgery was statistically significant for hemophilia A ($30,310 ± 52,745, P < 0.001) and von Willebrand factor ($20,355 ± 23,570, P < 0.001) compared with control ($14,564 ± 9512). Length of hospital stay, postoperative hemorrhage, concomitant injuries to the knee, additional ACL injury, infection rate, deep-vein thrombosis, and pulmonary embolism were not statistically significant. None of the hemophilia A or von Willebrand factor patients received blood products intraoperatively or postoperatively.ConclusionHemophilia A and von Willebrand factor patients had rates of postoperative complications and ACL re-injuries that were not statistically significant. Cost of healthcare utilization was identified as dramatically greater for hemophilia A and von Willebrand factor patients.     

Over-the-top Anterior Cruciate Ligament (ACL) reconstruction plus lateral plasty with hamstrings in high-school athletes: Results at 10 years

BackgroundAnterior Cruciate Ligament (ACL) injuries have grown in adolescent population in the last decades, and if surgical reconstruction resulted safe in the short term, its impact in the long term is still unclear. The purpose of this study was to assess the long-term risk of failure, the rate of contralateral injury and the clinical reported outcomes in a cohort of high-school athletes after ACL reconstruction.Methods54 consecutive patients (mean age 16.3 ± 1.4 years) underwent ACL reconstruction with a single-bundle plus lateral plasty hamstring technique between May 2006 and July 2009. The number of subsequent ipsilateral reoperations and contralateral ACL reconstruction, Lhysolm, KOOS, VAS for pain and Tegner Activity Level was determined at a minimum follow-up of 10 years.ResultsIpsilateral ACL revision was performed in 8 (3.4%) patients, contralateral ACL reconstruction in 11 (21.1%). The average Lysholm score was 95.1 ± 9.2. The average KOOS was 96.5 ± 6.3 for the Pain subscale, 92.2 ± 9.0 for the Symptom subscale, 99.2 ± 1.8 for the ADL subscale, 94.1 ± 10.1 for the Sport subscale and 91.8 ± 14.5 for the Quality-of-life subscale. The average VAS for pain during activity was 1.7 ± 2.3. 90% returned to sport, 15% decreased the activity level, 61% of patients were still involved in sport, 35% at the same pre-injury level.ConclusionAt long-term, single-bundle hamstring ACL-R plus lateral-plasty in a cohort of high school athletes resulted to have a comparable graft failure rate and contralateral ACL injury with other surgical techniques.     

Patellar tendon reconstruction with hamstring autograft for the treatment of chronic irreparable patellar tendon injuries

BackgroundPatellar tendon injuries not amenable to primary repair present a challenging problem for surgeons and patients alike. No standard surgical technique exists for these injuries and few studies report outcomes after surgical treatment.MethodsA retrospective analysis was conducted for patients undergoing surgical treatment for irreparable patellar tendon tears. Patients were treated with an indirect tendon reconstruction technique using high-strength suture to set initial patellar height and hamstring autograft for biologic augmentation. Patients who underwent this procedure between 2012 and 2018 and met minimum two-year follow-up with completion of all outcome measurements including KOOS, PROMIS, VAS pain and satisfaction scores were included.ResultsEleven patients met inclusion criteria. Ten of eleven patients (91%) had intact repairs and final patient outcomes were collected at a mean of 54.9 ± 23.1 months after surgery. Only one patient experienced extensor lag at final follow-up (p < 0.001). The preoperative Caton–Dechamps ratio was 1.77 ± 0.58, which decreased to 0.98 ± 0.25 after surgery (p < 0.001). The mean postoperative KOOS ADL score was 61.5. The mean postoperative PROMIS Global Mental and Physical Health scores were 46.9 ± 8.7 and 42.0 ± 9.8. Post-operative mean VAS satisfaction score was 5.6 ± 3.4.ConclusionsPatellar tendon reconstruction with autologous hamstring tendon graft and suture augmentation allows for acceptable outcomes in the setting of patellar tendon disruption with segmental defects when direct repair is not possible.     

3D CT analysis of femoral and tibial tunnel positions after modified transtibial single bundle ACL reconstruction with varus and internal rotation of the tibia

IntroductionWe analyzed the location of femoral and tibial tunnels by three-dimensional (3D) CT reconstruction images after modified transtibial single bundle (SB) anterior cruciate ligament (ACL) reconstruction, creating a femoral tunnel with varus and internal rotation of the tibia.Material and methodsData from 50 patients (50 knees) analyzed by 3D CT after modified transtibial SB ACL reconstructions were evaluated. 3D CT images were analyzed according to the quadrant method by Bernard at the femur and the technique of Forsythe at the tibia.ResultsThe mean distance of the femoral tunnel center locations parallel to the Blumensaat's line was 29.6% ± 1.9% along line t measured from the posterior condylar surface. The mean distances perpendicular to the Blumensaat's line were 37.9% ± 2.5% along line h measured from the Blumensaat's line. At the tibia, the mean anterior-to-posterior distance for the tunnel center location was 37.8% ± 1.2% and the mean medial-to-lateral distance was 50.4% ± 0.9%.DiscussionThe femoral and tibial tunnels after modified transtibial SB ACL reconstruction creating a femoral tunnel with varus and internal rotation of the tibia (figure-of-4 position) were located between the anatomical anteromedial and posterolateral footprints.     

Anterior cruciate ligament (ACL) repair using cortical or anchor fixation with suture tape augmentation vs ACL reconstruction: A comparative biomechanical analysis

BackgroundThe purpose was to compare knee kinematics in a cadaveric model of anterior cruciate ligament (ACL) repair using an adjustable-loop femoral cortical suspensory (AL-CSF) or independent bundle suture anchor fixation (IB-SAF) with suture tape augmentation to a bone-patellar tendon-bone (BPTB) ACL reconstruction.MethodsTwenty-seven cadaveric knees were randomly assigned to one of three surgical techniques: (1) ACL repair using the AL-CSF technique with suture tape augmentation, (2) ACL repair using the IB-SAF technique with suture tape augmentation, (3) ACL reconstruction using a BPTB autograft. Each specimen underwent three conditions according to the state of the ACL (native, proximal transection, repair/reconstruction) with each condition tested at four different angles of knee flexion (0°, 30°, 60°, 90°). Anterior tibial translation (ATT) and internal tibial rotation (ITR) were evaluated using 3-dimensional motion tracking software.ResultsACL transection resulted in a significant increase in ATT and ITR when compared to the native state (P < 0.001, respectively). ACL repair with the AL-CSF or IB-SAF technique as well as BPTB reconstruction restored native ATT and ITR at all tested angles of knee flexion, while showing significantly less ATT at 0°, 30°, 60°, and 90° as well as significantly less ITR at 30°, 60°, and 90° of knee flexion when compared to the ACL-deficient state. There were no significant differences in ATT and ITR between the three techniques utilized.ConclusionACL repair using the AL-CSF or IB-SAF technique with suture tape augmentation as well as BPTB ACL reconstruction each restored native anteroposterior and rotational laxity, without significant differences in knee kinematics between the three techniques utilized.Level of EvidenceControlled Laboratory Study.     

High variability in anterior cruciate ligament femoral footprint: Implications for anatomical anterior cruciate ligament reconstruction

BackgroundThe study aimed to (1) investigate the variability of the femoral ACL center in ACL-ruptured patients, (2) identify whether the currently available over-the-top femoral ACL guides could allow for anatomical reconstruction of the native ACL footprint.Material and methodsMagnetic resonance images of 95 knees with an ACL rupture were used to create three-dimensional models of the femur. The femoral ACL footprint area was outlined on each model, and the location of the femoral ACL center was reported using an anatomical coordinate system. The distance of the femoral ACL center from the over-the-top position was measured.ResultsThe femoral ACL center demonstrated a high intersubject variability ranging from 1.8 mm (9%) to 12.3 mm (60%) posterior and from 7.7 mm (37%) distal to 4.8 mm (23%) proximal using the posterior condyle circle reference. The average distance of the femoral ACL center from the over-the-top position was 1.9 ± 1.5 mm posterior and 13.8 ± 2.7 mm distal, respectively. The contemporary over-the-top femoral ACL aimers could restore the femoral ACL center in only 6.5% of the patients.ConclusionsThe femoral ACL center demonstrated a high variation on its location, which resulted in a high intersubject variability from the over-the-top position. The contemporary over-the-top femoral tunnel guides do not provide sufficient offset to allow for an anatomical ACL reconstruction. Anteromedial-portal specific femoral ACL guides with a femoral offset ranging from 10 to 18 mm in the proximal/distal direction are required to restore the native ACL footprint.     

The in vivo relationship between anterior neutral tibial position and loss of knee extension after transtibial ACL reconstruction

BackgroundRestoration of anterior tibial stability while avoiding knee extension deficit are a common goal of anterior cruciate ligament (ACL) reconstruction. However, achieving this goal can be challenging. The purpose of this study was to determine whether side-to-side differences in anterior tibial neutral position and laxity are correlated with knee extension deficit in subjects 2 years after ACL reconstruction.MethodsIn the reconstructed and contralateral knees of 29 subjects with transtibial reconstruction, anterior tibiofemoral neutral position was measured with MRI and three-dimensional modeling techniques; terminal knee extension at heel strike of walking and during a seated knee extension were measured via gait analysis; and anterior laxity was measured using the KT-1000.ResultsKnees that approached normal anterior stability and anterior tibial position had increased extension deficit relative to the contralateral knee. On average the reconstructed knee had significantly less (2.1 ± 4.4°) extension during active extension and during heel strike of walking (3.0 ± 4.3º), with increased anterior neutral tibial position (2.5 ± 1.7 mm) and anterior laxity (1.8 ± 1.0 mm). There was a significant correlation between side-to-side difference in anterior neutral tibial position with both measures of knee extension (walking, r = − 0.711, p < 0.001); active knee extension, r = − 0.544, p = 0.002).ConclusionThe results indicate a relationship between the loss of active knee extension and a change in anterior neutral tibial position following non-anatomic transtibial ACL reconstruction. Given the increasing evidence of a link between altered kinematics and premature osteoarthritis, these findings provide important information to improve our understanding of in vivo knee function after ACL reconstruction.     

Failure rate analysis and clinical outcomes of two different femoral tunnel positions using anteromedial portal technique in anterior cruciate ligament reconstruction

AimTo analyze two different femoral tunnel positions and to evaluate their correlation with clinical, functional outcomes and surgical revision rate in patients who underwent primary arthroscopic anterior cruciate ligament (ACL) reconstruction with anteromedial (AM) portal technique.MethodsFrom January 2015 to October 2018, we recruited 244 patients that underwent primary single-bundle ACL reconstruction, using four strand-semitendinosus graft and AM portal technique for femoral tunnel placement. Patients were divided into two groups based on the different femoral tunnel positions: 117 patients of group A had ACL footprint center femoral tunnel position compared with 127 patients of group B, with femoral tunnel placement close to the AM bundle footprint. Preoperatively and at last follow up, all patients were assessed subjectively by Lysholm, Tegner, and International Knee Documentation Committee (IKDC) scores, while Lachman, Pivot-shift, and KT-1000 tests were performed to evaluate knee joint stability.ResultsGroup B patients showed significantly better results in Lysholm, objective, and subjective IKDC scores compared with patients of group A (P < 0.001). A significantly higher surgical failure rate was found in group A than in group B (10.26% vs. 2.3%; P < 0.001). A higher anterior knee laxity was recorded in patients of group A than in patients of group B (1.9 ± 1.1 vs. 1.3 ± 1 mm; P < 0.001); a reduction in mean anterior tibial translation from preoperative to final follow up was found in group B compared with group A (3.5 ± 1.2 vs. 2.7 ± 1.1 mm; P < 0.001). No significant differences in the Tegner scale were found between the two groups.ConclusionACL reconstruction performed using the AM portal technique showed better and more satisfactory clinical and functional outcomes associated with a lower failure rate when the femoral tunnel had been placed more eccentrically in the footprint, in the AM bundle center position.     

Biomechanical comparison of two medial patellofemoral ligament reconstruction techniques: Quadriceps tendon fixation versus single-tunnel patella fixation with gracilis autograft did not differ in load to failure and stiffness

BackgroundThe purpose of this study was to evaluate the ultimate failure load and stiffness of two patellar fixation techniques for medial patellofemoral ligament (MPFL) reconstruction: (1) quadriceps tendon fixation (QT), (2) single tunnel (STG) patella fixation with gracilis autograft.MethodsA total of 16 fresh-frozen cadaveric knees (eight matched pairs) were randomized into two groups (QT vs. STG). The MPFL reconstructions were subjected to cyclic loading for 10 cycles to 30 N and then tested to failure at a constant displacement rate of 15 mm/min using a materials-testing machine (MTS 810 Universal Testing System). Failure mode, ultimate failure load and stiffness were recorded for each cadaveric specimen.ResultsThere was no significant difference in mean ultimate failure load among groups (P = 0.35). The STG group failed at a mean ultimate load of 190.04 N [standard deviation (SD) 23.18] and the QT group failed at 206.24 N (SD 37.99).The STG group had a mean stiffness of 21.38 N/mm (SD 1.44). This was not significantly higher than the mean stiffness value achieved for the QT group at 20.36 N/mm (SD 1.3) (P = 0.19). In the QT group all reconstructions failed due to tendon rupture at the patella attachment. The reason for failure in the STG group was the graft–suture connection.ConclusionsThis cadaver study showed no statistically significant difference in biomechanical performance of the evaluated patella fixation techniques, in terms of maximum load to failure and stiffness. Both techniques are reliable in terms of biomechanical properties and could offer additional surgical solutions.     

Relationship between anterior cruciate ligament and anterolateral meniscal root bony attachment: High-resolution 3-T MRI analysis

BackgroundThe tibial bony attachments of the anterior cruciate ligament (ACL) and the anterolateral meniscal root (ALMR) are very close, and drilling the tibial tunnel in ACL reconstruction may damage the ALMR attachment. This study investigated the relationship between the tibial attachment of the ACL and ALMR using high-resolution 3-T magnetic resonance imaging (MRI).MethodsTwenty healthy subjects (35.8 ± 13.0 years) had 20 knees scanned using high resolution 3-T MRI. The tibial bony attachments of ACL, ALMR, and the tibia were segmented and three-dimensional models were created. The shape, area, and location of each attachment were evaluated using this model.ResultsThe ACL tibial attachment was elliptical in nine knees (45%), C-shaped in nine knees (45%) and triangle in two knees (10%). The mean values of the ACL vs ALMR tibial attachments were as follows: area, 106.2 ± 21.3 vs 56.2 ± 21.3 mm²; length, 16.8 ± 2.0 vs 11.0 ± 1.8 mm; and width, 6.9 ± 1.3 vs 6.6 ± 1.0 mm. The location of the ACL vs ALMR attachment centres was 46.5 ± 1.7% vs 56.5 ± 1.9% in the medial-lateral direction and 36.3 ± 3.6% vs 36.7 ± 3.5% in the anterior–posterior direction. The distance between the ACL and ALMR centres was 8.1 ± 1.3 mm.ConclusionsACL and ALMR tibial attachments were individually distinguished using high resolution 3-T MRI. The short distance between both centres of the attachments may suggest that ALMR can be damaged when the tibial tunnel is drilled in ACL reconstruction.     

MPFL reconstruction using a quadriceps tendon graft: Part 2: Operative technique and short term clinical results

BackgroundWe describe the preliminary clinical results of a new operative technique for MPFL reconstruction using a strip of quadriceps tendon (QT).MethodsPatients: 17 patients (7 male, 10 female; mean age 21.5 years ± 3.9) have been operated on with this technique. All patients were evaluated clinically, radiologically and with subjective questionnaires (Tegner-, Lysholm-, Kujala Score) pre-operatively and post-operatively at 6 and 12 months (m).Surgical technique: A 10 to 12 mm wide, 3 mm thick and 8 to 10 cm long strip from the central aspect of quadriceps tendon is harvested subcutaneously. The tendon strip is then dissected distally on the patella, left attached, diverged 90° medially underneath the medial prepatellar tissue and fixed with 2 sutures. The graft is fixed in 20° of knee flexion with a bioabsorbable interference screw.ResultsLysholm score at 6 m was 81.9 ± 11.7 and at 12 m 88.1 ± 10.9, Kujala score at 12 m was 89.2 ± 7.1 and Tegner Score was 4.9 ± 2.0 (6 m) and 5.0 ± 1.9 (12 m). Two patients had a positive apprehension test at 12 months. There was no re-dislocation during the follow-up period.ConclusionMPFL reconstruction with a strip of QT harvested in a minimal invasive technique was found to be associated with good short term clinical results. We think that this technique presents a valuable alternative to common hamstring techniques for primary MPFL reconstruction in children and adults, as well as for MPFL revision surgery.Level of evidenceIV, prospective case series.     

Reliability of a semi-automated 3D-CT measuring method for tunnel diameters after anterior cruciate ligament reconstruction: A comparison between soft-tissue single-bundle allograft vs. autograft

BackgroundPost-operative widening of tibial and/or femoral bone tunnels is a common observation after ACL reconstruction, especially with soft-tissue grafts. There are no studies comparing tunnel widening in hamstring autografts versus tibialis anterior allografts. The goal of this study was to observe the difference in tunnel widening after the use of allograft vs. autograft for ACL reconstruction, by measuring it with a novel 3-D computed tomography based method.MethodsThirty-five ACL-deficient subjects were included, underwent anatomic single-bundle ACL reconstruction and were evaluated at one year after surgery with the use of 3-D CT imaging. Three independent observers semi-automatically delineated femoral and tibial tunnel outlines, after which a best-fit cylinder was derived and the tunnel diameter was determined. Finally, intra- and inter-observer reliability of this novel measurement protocol was defined.ResultsIn femoral tunnels, the intra-observer ICC was 0.973 (95% CI: 0.922–0.991) and the inter-observer ICC was 0.992 (95% CI: 0.982–0.996). In tibial tunnels, the intra-observer ICC was 0.955 (95% CI: 0.875–0.985). The combined inter-observer ICC was 0.970 (95% CI: 0.987–0.917). Tunnel widening was significantly higher in allografts compared to autografts, in the tibial tunnels (p = 0.013) as well as in the femoral tunnels (p = 0.007).ConclusionsTo our knowledge, this novel, semi-automated 3D-computed tomography image processing method has shown to yield highly reproducible results for the measurement of bone tunnel diameter and area. This series showed a significantly higher amount of tunnel widening observed in the allograft group at one-year follow-up.Level of evidenceLevel II, Prospective comparative study.     

Notchplasty in anterior cruciate ligament reconstruction in the setting of passive anterior tibial subluxation

PurposeIn an effort to minimize graft impingement among various ACL deficient states, we sought to quantitatively determine requirements for bone resection during notchplasty with respect to both volumetric amount and location.MethodsA validated method was used to evaluate Magnetic Resonance Imaging scans. We measured the ATT of the medial and lateral compartments in the following four states: intact ACL (27 patients), acute ACL disruption; < 2 months post-injury (76 patients), chronic ACL disruption; 12 months post-injury (42 patients) and failed ACL reconstruction (75 patients). Subsequently, 11 cadaveric knees underwent Computed Tomography (CT) scanning. Specialized software allowed virtual anterior translation of the tibia according to the average ATT measured on MRI. Impingement volume was analyzed by performing virtual ACLRs onto the various associated CT scans. Location was analyzed by overlaying an on-screen protractor. The center of the notch was defined as 0°.ResultsAverage impingement volume changed significantly in the various groups compared to the intact ACL group (acute 577 ± 200 mm³, chronic 615 ± 199 mm³, failed ACLR 678 ± 210 mm³, p = 0.0001). The location of the required notchplasty of the distal femoral wall border did not change significantly. The proximal femoral border moved significantly towards the center of the notch (acute 8.6° ± 4.8°, chronic 7.8° ± 4.2° (p = 0.013), failed ACLR 5.1° ± 5.9° (p = 0.002)).ConclusionOur data suggests that attention should be paid peri-operatively to the required volume and location of notchplasty among the various ACL deficient states to minimize graft impingement.