Interference Screw Fixation Research Articles

A biomechanical comparison of two arthroscopic suture techniques in biceps tenodesis: whip-stitch vs. simple suture techniques

The aim of this study was to compare the biomechanical performance of whip-stitch (WS) and simple suture techniques (SST) of the long head of the biceps tendon in suprapectoral intraosseous tenodesis with interference screw fixation. A total of 10 paired cadavers (61.1 ± 4.6 years) were randomized to receive WS or SST biceps tenodesis beginning at the musculotendinous junction. Both groups implemented a No. 2 FiberLoop wire and underwent suprapectoral fixation with a polyetheretherketone interference screw at the bicipital grove. A Materials Testing System performed cyclic testing (500 cycles), followed by load to failure at 1 mm/s. Load, displacement, and time were recorded during cyclic and failure testing. A 2-tailed Student's t-test and χ2 analysis were performed for failure load and mode of failure, respectively. Two SST specimens and 1 WS specimen failed during cyclic loading via tendon rupture at the screw-tendon interface. There was no significant statistical difference in the cyclic displacement after 500 cycles between the WS (12.9 mm ± 4.4 mm) and SST groups (14.0 mm ± 3.8 mm, P = .2); cyclic strain, defined as the peak displacement at the 500th cycle divided by the initial gauge length, betweenthe WS (0.4 ± 0.2) and SST groups (0.7 ± 0.7, P = .3); maximal load (162.7 N ± 56.8 N vs. 153.1 N ± 39.3 N, respectively, P = .6); and stiffness (50.5 N/mm ± 17.7 N/mm vs. 43.3 N/mm ± 10.9 N/mm, respectively, P = .3). All specimens ruptured at the screw-tendon interface. The WS technique can provide equivalent biomechanical performance to the SST in suprapectoral intraosseous biceps tenodesis with interference screw fixation.

ACL reconstruction with quadriceps tendon graft and press-fit fixation versus quadruple hamstring graft and interference screw fixation \u2013 a matched pair analysis after one year follow up

BackgroundThe objective of the study was to compare the results of a primary anterior cruciate ligament reconstruction (ACLR) using the press-fit fixation technique for a quadriceps tendon (QT) graft to a standard quadrupled hamstring (HT) graft with interference screw fixation.MethodsA retrospective cohort study with a 12-month follow up provided data for 92 patients. Exclusion criteria were accompanying ligament injuries and contralateral ACL injury. Patients who suffered a graft failure, which was defined as a side-to-side difference of > 3 mm, or infection were rated ‘D’ according to the IKDC and excluded from further evaluation. Forty-six patients underwent primary ACLR using the press-fit fixation technique for autologous bone QT graft. These patients were matched in terms of age, gender, accompanying meniscus tear and cartilage injury to 46 patients who underwent standard HT graft with interference screw fixation. Patients were evaluated according to the Lachman test, Pivot-Shift test, IKDC score, Tegner score, Rolimeter measurements, one-leg hop test, thigh circumference and donor side morbidity.ResultsNo significant differences in Tegner score (p = 0.9), subjective or objective IKDC score (p = 0.9;p = 0.6), knee stability (Lachman Test p = 0.6; Pivot-Shift Test p = 0.4; Side-to-Side Difference p = 0.4), functioning testing (One-Leg Hop Test p = 0.6; Thigh Circumference p = 0.4) or donor side morbidity (p = 0.4) were observed at the follow up. The Lachman test was negative for 85% of the QT group and 83% of the HT group. The Pivot Shift Test was negative for 80% of the QT group and 85% of the HT group. The mean side-to-side difference was 1.6 ± 0 .2mm in both groups. The one-leg hop test revealed a collateral-side jumping distance of 96.2 ± 8.5% for the QT group and 95.5 ± 8.5% for the HT group. The thigh circumference of the injured leg was 98.3 ± 3.0% on the uninjured side in the QT group and 99.7 ± 3.0% in the HT group. A knee walking test resulted in no discomfort for 90% of the QT group and 85% of the HT group. The graft failure rate was 7.3% in the QT group and 9.8% in the HT group.ConclusionQT grafts fixated using the press-fit technique are a reliable alternative for primary ACL surgery.

Radiostereometric Analysis of Subpectoral versus Suprapectoral Biceps Tenodesis with Interference Screw Fixation

Objectives: Biceps tenodesis is performed with increasing frequency for various pathologies of the long head biceps tendon (LHBT). Multiple surgical techniques and devices for tenodesis have been described with favorable outcomes. The subpectoral approach provides adequate clinical outcomes; furthermore, recent research suggests that similar outcomes can be achieved via arthroscopic suprapectoral biceps tenodesis. Previous studies have compared the biomechanical profile of suprapectoral and subpectoral biceps tenodesis. There is a paucity of data regarding the biomechanical behavior and construct stability of suprapectoral and subpectoral biceps tenodesis in vivo. The purpose of this investigation is to quantify and compare the behavior of the biceps tenodesis construct in arthroscopic suprapectoral (ASPBT) and open subpectoral (OSPBT) techniques, with radiostereometric analysis (RSA). Methods: This is a prospective cohort study comparing migration of the biceps tendon after suprapectoral and subpectoral biceps tenodesis with Polyetheretherketone (PEEK) interference screw fixation. Thirty consecutive patients were allocated to the subpectoral group, follow by thirty consecutive patients to the suprapectoral group. Patients aged 18-65 years with symptomatic biceps tendinopathy, anterior intertubercular groove tenderness, and positive biceps tension tests were included in the investigation. Patients undergoing revision biceps tenodesis, shoulder arthroplasty, or ruptured LHBT were excluded. A mini skin staple, functioning as a radiostereometric marker, was placed longitudinally within the tendon prior to final fixation with interference screw. Staple stability was confirmed with a hemostat to gravity. The distance from the most proximal portion of the mini skin staple and the most proximal aspect of the humeral head was measured. Following final fixation with an interference screw, AP radiographs were obtained intraoperatively. Follow-up radiographs were one week and 12 weeks post-operatively. A paired and non-paired students t-test were utilized to assess for intra-group and inter-group changes, respectively. Results: A total of 60 consecutive patients (30 per group) were enrolled and available for follow-up imaging at 1 and 12 weeks postoperatively. The average age was 43.5±10.5 years, average BMI was 28.3±5.4, and 50% of the patients were females. Groups were similar with respect to patient demographics and concomitant procedures (P>.05). In the OSPBT group, the average distance of the radiostereometic marker to the proximal humeral head increased on by 26.0 mm (SD, 15.7) from the immediate post-operative radiograph to 3 months postoperatively (P=0.002). In the ASPBT group, the average distance also significantly increased by 24.7 mm (SD, 14.9) from the immediate post-operative radiograph to 3-months postoperatively (P=0.001). The change in distal migration between the ASPBT and OSPBT was not found to be statistically significant (P> 0.05). Conclusion: Biceps tenodesis performed with a PEEK tenodesis screw results in significant distal migration of the biceps tendon by 3 months post-operatively; however, there was no significant difference in distal migration between the OSPBT and ASPBT groups.

Comparison of suture anchor vs. interference screw technique for patellar fixation for medial patellofemoral ligament reconstruction

Summary Background There are numerous techniques for MPFL reconstruction, however, one single technique has not been proven to be superior to another. Suture anchor reconstruction has been shown to provide stable fixation while decreasing the risk of patellar fracture. Purpose The aim of the study was to compare the stiffness and clinical load to failure of two common MPFL reconstruction techniques. Our hypothesis was that there would be no significant difference in the stiffness and the clinical load to failure between the suture anchor and interference screw reconstructions. Methods Eight pairs of fresh frozen cadaveric knees were randomized into two groups undergoing MPFL reconstruction using either a suture anchor technique (n = 8) or an interference screw technique (n = 8). Testing was performed at 0, 30, 60, and 90 degrees of flexion for the native knee, transected medial structures, and reconstructed MPFL. Next, the reconstructed MPFL specimens were tested until failure in 0 degrees of flexion. t-Test, One-Way ANOVA, and repeated measures of ANOVA were used for statistical analysis, p values less than 0.05 were considered significant. Results The average stiffness for the suture anchor and interference screw reconstructions was 12.02 ± 3.96 N/mm and 14.21 ± 4.20 N/mm, respectively (t-test, p = 0.27), while average clinical load to failure was 256.57 ± 54.1 N and 237.81 ± 23.82 N, respectively (t-test, p = 0.38). There was no significant difference in stiffness between the suture anchor and interference screw techniques at 0, 30, and 60 degrees of flexion. Conclusions The suture anchor and interference screw reconstruction techniques produce comparable stiffness for sub-failure testing at 0 and 30 degrees of flexion. For testing to failure, the initial stiffness for both reconstruction techniques have been shown to be concordant with previously published values for the native MPFL. Both reconstruction techniques provide greater ultimate failure loads than those reported for the native MPFL in previous studies. Suture anchor reconstruction described in our study provides another reliable option for the reconstruction of the medial patellofemoral ligament. Clinical relevance Our study provides biomechanical data that the suture anchor technique described in this study provides comparable fixation compared to interference screw fixation and has the potential of reducing fracture to patella particularly in the pediatric population with small patellae.

A comparison of functional outcome between interference screw and endobutton fixation on femur in arthroscopic anterior cruciate ligament reconstruction

Background: Arthroscopic Anterior Cruciate Ligament [ACL] reconstruction is very commonly done procedure in recent times. The graft fixation methods vary from aperture fixation [Interference screws] to suspensory fixation methods [Endobutton]. Objective: To compare the functional outcome between interference screw and endobutton fixation on femur in arthroscopic anterior cruciate ligament reconstruction Methods: Two groups of 10 patients who underwent autogenous hamstring ACL reconstruction with a minimum of 1 year follow up evaluation were included in the study. The aperture fixation group underwent interference screw fixation at both femoral and tibial tunnels. The suspensory fixation group underwent endobutton fixation on the femoral side and biointerference screw on tibial side. Both group patients were examined prior to surgery and at 3 months, 6 months and 1 year. They were compared for functional outcome with Tegner Lysholm knee score. Results: There was significant improvement in functional outcome in both the groups for base and at 3 months, also for 3 months and 6 months but for 6 months to 1 year Group 2 is almost significant. Conclusion: In our prospective study of comparison of functional outcomes between aperture fixation and suspensory fixation on femur in arthroscopic ACL reconstruction which were evaluated by using Tegner Lysholm knee score over a period of 1 year, suspensory fixation was found to be better. However, further long term studies involving large series of cases would throw more light on this information.

A Comparison of Functional Outcomes After Biostable and Bioabsorbable Interference Screw Fixations in Arthroscopic ACL Reconstruction

A Comparison of Functional Outcomes After Biostable and Bioabsorbable Interference Screw Fixations in Arthroscopic ACL Reconstruction

Fixation par vis percutanée de neutralisation du scaphoïde lors d’une greffe osseuse par arthroscopie

Arthroscopic cancellous bone grafting of the scaphoid is a technique with many potential advantages - high union rates, minimally invasive and less deep scarring. The associated fixation is generally buried Kirschner wire fixation, as described by PC Ho. The fixation must remain in situ until union is confirmed, and generally mobilisation must be minimal while the wires remain, due to the risk of migration and soft tissue irritation. Since cancellous bone grafting is performed, which will not resist compression, headless compression screws are not preferred, since they may lead to deformity, in the presence of a defect. We have designed a non-compressive neutralisation screw, which will hold the scaphoid in its corrected position before the cancellous graft is inserted. The rationale for the implant design is discussed, and the surgical considerations which have been considered in fine tuning the technique. Finite element analysis of the implant versus 3 K-wires is presented. The surgical technique and some cases are presented. Dry arthroscopy is the presenter's preferred option. My preference is for 3 midcarpal ports, the most ulna is the radial midcarpal. The non-union is debrided to cancellous bone. The wrist is then removed from traction. If there is deformity, a temporary Linscheid wire may be used to stabilise the lunate to the radius. The wrist is then extended over a bump and a retrograde K-wire inserted with image intensification. The correction and wire position are assessed with fluoroscopy. The wire is over-drilled, then the screw inserted. Traction is re-applied and the joint and fixation assessed arthroscopically. Cancellous bone graft is then inserted and sealed with fibrin glue. The interference screw fixation is markedly more stable than 3 K-wire fixation, as assessed by finite element analysis. Some cases where passive motion has begun prior to bony union are presented. This screw design has the potential advantages of increased stability, which may allow the surgeon to hold correction of deformity without the use of a post-operative Linscheid type wire. It also allows earlier motion, which in conjunction with arthroscopic surgery, may lead to improved range of motion. It also avoids associated K-wire complications and the need for K-wire removal. The role of intereference, non-compressive screw fixation with arthroscopic scaphoid bone grafting is presented.

Adjustable-length loop cortical button versus interference screw fixation in quadriceps tendon anterior cruciate ligament reconstruction – A biomechanical in vitro study

BackgroundThis biomechanical cadaveric in vitro study aimed to evaluate and compare the dynamic elongation behavior and ultimate failure strength of tibial adjustable-length loop cortical button versus interference screw fixation in quadriceps tendon-based anterior cruciate ligament reconstruction. MethodsSixteen human quadriceps tendons were harvested and fixed into porcine tibiae using either biodegradable interference screw (n = 8) or adjustable loop device (n = 8) fixation. An acrylic block was utilized for femoral adjustable loop device fixation for both groups. All constructs were precycled for 10 times at 0.5 Hz and manually retensioned before tested in position and force control mode each for 1000 cycles at 0.75 Hz according to in vitro loading conditions replicating the in vivo ACL environment. Subsequently, an ultimate failure test at 50 mm/min was performed with mode of failure noted. FindingsTibial IS fixation showed no statistically significant differences in the initial (−0.46 vs. −0.47 mm; P = 0.9780), dynamic (2.18 mm vs. 2.89 mm; P = 0,0661), and total elongation (1.72 mm vs. 2.42 mm; P = 0,0997) compared to adjustable loop device fixation. The tibial button fixation revealed an increased ultimate failure load (743.3 N vs. 606.3 N; P = 0.0027), while stiffness was decreased in comparison to screw fixation (133.2 N/mm vs. 153.5 N/mm; P = 0,0045). InterpretationAnterior cruciate ligament reconstruction for quadriceps tendon graft using a tibial adjustable-length loop cortical button provides for comparable dynamic stabilization of the knee with increased ultimate failure load at decreased stiffness compared to screw fixation.

Clinical and Functional Outcomes of Anterior Cruciate Ligament Reconstruction at a Minimum of 2 Years Using Adjustable Suspensory Fixation in Both the Femur and Tibia: A Prospective Study.

Background:The success of anterior cruciate ligament (ACL) reconstruction requires reliable and rigid graft fixation. Cortical suspensory fixation (CSF) devices have become an acceptable alternative to interference screws for soft tissue ACL grafts. However, CSF devices have been reported to be associated with tunnel widening and increased postoperative anterior laxity compared with interference screw fixation. Adjustable CSF devices were introduced to avoid these problems but have been associated with graft lengthening and inconsistent outcomes.Purpose:To (1) report the side-to-side difference (SSD) in anterior laxity at 150 N, clinical scores, and failure rates 2 years after ACL reconstruction with 4-strand semitendinosus autografts using an adjustable CSF device and (2) determine the preoperative factors associated with clinical outcomes.Study Design:Case-control study; Level of evidence, 3.Methods:A total of 131 patients who had undergone primary ACL reconstruction, performed with 4-strand semitendinosus grafts that were secured using Pullup adjustable-length CSF devices with femoral and tibial fixation techniques, were prospectively enrolled in this study; 34 patients were excluded because of contralateral instability or ipsilateral knee injuries that required additional surgery. This left a cohort of 97 patients who were evaluated preoperatively and at 6, 12, and 24 months. The evaluation consisted of measuring the SSD in anterior laxity and patient-reported outcome scores (International Knee Documentation Committee [IKDC] and Lysholm scores). Regression analyses were performed to determine associations between these outcomes and 9 preoperative variables.Results:Only 2 patients could not be reached, 2 could not be evaluated because of contralateral ACL tears, and 2 had graft failure. At 2-year follow-up, the remaining 91 patients had a mean SSD in anterior laxity of 0.8 ± 1.8 mm (range, –4.2 to 5.3 mm), mean IKDC score of 87.6 ± 10.6 (range, 43.7-100.0), and mean Lysholm score of 90.8 ± 9.3 (range, 56.0-100.0). At final follow-up, compared with knees with partial ruptures, those with complete ruptures had equivalent laxity (P = .266) and Lysholm scores (P = .352) but lower IKDC scores (P = .009). Multivariable regression revealed that the IKDC score decreased with increased preoperative laxity (β = –1.35 [95% CI, –2.48 to –0.23]; P = .019).Conclusion:The novel adjustable-length CSF device produced satisfactory anterior laxity and clinical outcomes, with a failure rate of 2.1%, which compare favorably with those reported for nonadjustable CSF devices.

Anatomic double-bundle anterior cruciate ligament reconstruction using soft tissue interference screw fixation

An anatomic double-bundle anterior cruciate ligament (ACL) reconstruction technique has been reported to have better or at least similar results than a single-bundle technique in many randomized controlled trials. However, most of these studies have used cortical fixation for the graft fixation, which may not be as anatomic as the aperture fixation. Already 15 years ago we started to perform a double-bundle ACL reconstruction with aperture fixation using bioabsorbable interference screws, and started a prospective, randomized study comparing this technique to a single-bundle technique for ACL reconstruction. The purpose of this review is to introduce the technique and results of the anatomic double-bundle ACL reconstruction with bioabsorbable interference screw fixation comparing to the single-bundle ACL reconstruction with interference screw fixation. According to our prospective, randomized trial, the anatomic double-bundle ACL reconstruction with bioabsorbable interference screw fixation resulted in significantly better clinical results than the single-bundle ACL reconstruction during the 10-year follow-up. At the beginning, rotational stability was better with the double-bundle technique, and during the years fewer graft failures leading to ACL revision surgery was found with the double-bundle procedure. The double-bundle ACL reconstruction is stronger and more durable than the single-bundle ACL reconstruction even at the 10-year follow-up. The bioabsorbable interference screws used for the graft fixation seem to absorb totally in 2 to 5 years, and are replaced by bone after they have absorbed. No adverse effects related to these screws were found during the 10-year follow-up.

Revision ACL reconstruction with autograft: long-term functional outcomes and influencing factors.

To present the long-term functional outcomes of revision anterior cruciate ligament (ACL) reconstruction with autograft and factors that influence the outcomes. Retrospective study of 51 consecutive revision ACL reconstructions performed using autograft under the care of a single surgeon with interference screw fixation. Bone-patellar tendon-bone graft was used in 35 (69%) and hamstring tendons in 16 (31%). The subjective IKDC activity level and Lysholm Knee functional scores were collected at mean follow-up of 9.0years (range 5.17-14.75years). Five (9.8%) had re-ruptured and one patient had a total knee replacement. Functional scores were available for 43 patients (84.3%). Twenty-eight had IKDC activity level I or II (65%), level III in 12 (28%) and level IV in 3 (7%). The average Lysholm score was 86.2 ± 12.88, and there is a statistically significant relationship with age (95% CI: - 0.88, - 0.60) (P < 0.05). For each additional 10years of age, there is a reduction of 5.18 points. No statistically significant effect of sex has been detected. The mean Lysholm score was lower in patients who had partial medial meniscectomy (77.33), although this was not statistically significant (P = 0.06). Regression analysis of the Lysholm score means by chondral damage category adjusted for age, showed that the Grade 3 or 4 group shows a reduction of about 25 points for every 10years increase in age (95% CI; P = 0.05). Revision ACL reconstruction with autograft affords satisfactory long-term outcomes. Expectations should be carefully managed in patients with increasing age associated with severe chondral damage and previous medial meniscectomy.

Anterior Laxity at 2 Years After Anterior Cruciate Ligament Reconstruction Is Comparable When Using Adjustable-Loop Suspensory Fixation and Interference Screw Fixation

Background: Adjustable-loop suspensory fixation (ALSF) devices are commonly used in anterior cruciate ligament reconstruction (ACLR). However, concern exists regarding the potential for lengthening under cyclical loads. Purpose: To compare the residual anterior laxity of 2 methods of femoral fixation, ALSF versus interference screw fixation, in patients undergoing isolated ACLR in the absence of meniscal injuries. To determine the preoperative risk factors associated with residual postoperative anterior laxity. Study Design: Cohort study; Level of evidence, 3. Methods: A retrospective analysis was performed comparing 2 groups of patients that underwent primary ACLR using ALSF versus bioabsorbable interference screw fixation. Anterior knee laxity was assessed with Telos stress radiography, while functional outcomes were evaluated with the Knee injury and Osteoarthritis Outcome Score (KOOS) and Tegner activity level scale at a minimum of 2 years postoperatively. A multivariate analysis was performed to identify factors associated with residual postoperative laxity >3 mm. Results: Of the 1136 patients who underwent ACLR during the study period, 363 met the inclusion criteria. A total of 272 patients (75%) (mean age, 31.7 ± 10.7 years) with a mean follow-up of 25.7 ± 4.6 months (range, 24-36 months) consented to participate (screw group: n = 121; ALSF group: n = 151). The 2 groups were statistically comparable in terms of age, sex ratio, time from injury to surgery, graft diameter, preoperative laxity, preoperative objective International Knee Documentation Committee (IKDC) grade, and preoperative Tegner score. The mean postoperative laxity as a continuous variable was significantly different comparing the ALSF and screw groups (1.49 ± 1.98 mm and 2.32 ± 1.97 mm, respectively; P < .001). In the screw group, 76 patients (62.8%) had normal (<3 mm), 40 (33.1%) had nearly normal (3-6 mm), and 5 (4.1%) had abnormal (≥6 mm) postoperative knee laxity according to the IKDC grade, while in the ALSF group, 112 patients (74.2%) had normal, 37 (24.5%) had nearly normal, and 2 (1.3%) had abnormal laxity (P = .0833). No significant difference was found in KOOS or Tegner scores comparing the 2 femoral fixation methods: KOOS, 90.6 ± 7.5 (ALSF group) and 90.6 ± 7.4 (screw group) (P = .7631), versus Tegner, 6.5 ± 1.3 (ALSF group) and 6.3 ± 1.4 (screw group) (P = .2992). A negative correlation was found between postoperative laxity and final Tegner (rs = −0.303, P < .001) and KOOS scores (rs = −0.168, P = .005). The initial univariate analysis showed differences between groups of patients with residual knee laxity ≥3 mm and <3 mm on preoperative pivot shift, preoperative laxity, age, fixation type, and preoperative objective IKDC grade. The multivariate analysis on these factors showed that the pivot shift remained the only significant predictor for residual laxity ≥3 mm for pivot shift grade 2 compared with grade 1 (odds ratio, 4.689 [95% CI, 2.465-9.286]) and for pivot shift grade 3 compared with grade 1 (odds ratio, 58.025 [95% CI, 12.757-557.741]) (P < .001). Conclusion: For primary ACLR, the use of an ALSF device for femoral fixation is associated with noninferior postoperative anterior knee laxity results compared with interference screw fixation at a minimum 2 years’ follow-up. The preoperative pivot shift is the only significant risk factor for postoperative residual anterior knee laxity >3 mm.

Associated Anterior Cruciate Ligament and Fibular Collateral Ligament Reconstruction With Single Femoral Tunnel and Asymmetric Hamstring Tendon Graft

A technique for associated anterior cruciate ligament and fibular collateral ligament reconstruction is shown, using a single hamstring tendon graft, which is prepared asymmetrically, leaving one-third of the length with a single diameter and two-thirds with a double diameter. A single femoral tunnel is created, using an interference screw for fixation and isolation of the grafts. A suspension device is used for tibial fixation, allowing for length adjustment according to the graft's length. The objective of this Technical Note is to provide the orthopaedic surgeon with a resource for anterior cruciate ligament and fibular collateral ligament reconstruction even with short grafts, saving bone stock and avoiding the need for allografts.

Anterior Cruciate Ligament Reconstruction in Young Females: Patellar versus Hamstring Tendon Autografts

Objectives:Female athletes are two to eight times more likely to suffer a primary ACL tear than males. Although ACL reconstruction can successfully return many athletes to their pre-injury sports, re-injury to the ipsilateral or contralateral knee can occur in over 20% of young athletes. Both female sex and younger age have been shown to be risk factors for graft failure. The optimal graft choice for this high-risk population of young female athletes remains unknown and poorly studied. We compared the clinical outcomes in young female patients who underwent ACL reconstruction at our institution using bone-patellar tendon-bone (BTB) and quadrupled hamstring (HS) autografts.Methods:Female patients aged 15-25 who underwent primary ACL reconstruction at our institution between January 2012 and May 2015 using either BTB or HS autograft were included in our review. Patients were further sub-divided into 2 age groups, 15-20 and 20-25. Patients with a prior history of ACL injury to either knee, or those with multiligament injury were excluded. Graft choice and fixation method were documented from a review of operative records. Medical records were reviewed to document the occurrence of chondral, meniscal or ligamentous injury to the ipsilateral or contralateral knee in the first two years following ACL reconstruction. Comparisons were made using the chi-square test with statistical significance set at p < 0.05.Results:A total of 256 females were included in our review with 175 in the BTB group and 81 in the HS group. There was no difference between the groups with regards to average age or time to follow-up. The majority of patients in both groups, 80% of the BTB group and 77.8% of the HS group, were between the ages of 15-20. Interference screw fixation was used in all BTB cases and 63.0% of HS cases. In the remainder of HS cases, femoral suspension and tibial screw (27.2%), and femoral cross-pins and tibial screw (9.9%) were used. In our series, 22.2% of hamstring grafts were augmented with allograft due to inadequate size. Overall, graft re-tear occurred in 6.9% of BTB patients and 12.3% of HS patients [p=0.16]. Contralateral ACL tear occurred in 7.4% of BTB patients and 6.2% of HS patients [p=0.72]. Sub-group analysis showed that 75% of BTB and 100% of HS graft re-tears occurred in females aged 15-20. Within this group, there was a significantly lower rate of graft re-tears in the BTB group (6.4%) when compared to the HS group (15.9%) [p=0.04]. Allograft augmentation was used in four of the ten HS grafts that re-tore. The risk of failure with hamstring augmentation with allograft (4/18, 22.2%) was higher than that of hamstring autograft alone (6/63, 9.5%), but this difference was not significant [p=0.18].Conclusion:The results of our study indicate that BTB autograft led to fewer graft re-tears compared to HS autograft following ACL reconstruction in female patients aged 15-20. However, this difference was not observed in females aged 20-25. Thus, further investigation regarding optimal graft choice is warranted in this age group.

Peroneus brevis tendon transfer with the use of an interference screw in Achilles tendon injuries

Objective: To perform a functional evaluation of peroneus brevis tendon transfer using an interference screw fixation in chronic Achilles tendon injuries. Methods: This was a cross-sectional, retrospective and observational study with medical record reviews and a convenience sample of ten (10) patients who underwent surgery between January 2013 and June 2017. The following clinical aspects were evaluated: sex, age group, race, affected side, injury time, distal stump size, gap between stumps, AOFAS questionnaire (pre- and 3 and 6 months postoperatively), patient satisfaction with treatment and complications. Results: The mean subject age was 38.1 years; subjects were predominantly male (80%), and with respect to laterality, the right side was predominant. The paratendinous posterolateral incision technique was used, with the identification and use of the peroneus brevis associated with bone tunnel fixation onto the Achilles using an interference screw. Surgical planning of the technique followed the same procedure in all cases. Two complications occurred during evolution when considering the early and late postoperative periods. Conclusion: The treatment of Achilles tendon injuries with this technique proved to be a good option for chronic injuries with satisfactory results in terms of maintenance of functionality and patient satisfaction postoperatively. Level of Evidence III; Prognostic Studies; Retrospective Study.

Anatomic Basis for Minimally Invasive Flexor Hallucis Longus Transfer in Chronic Achilles Tendon Rupture

The present cadaveric study was designed to measure the flexor hallucis longus (FHL) tendon length and obtain anatomic data regarding the graft-to-tunnel length ratio in an interference screw fixation model for the FHL short-harvest single-incision technique to the calcaneus. Ten fresh-frozen paired cadaveric specimens were used for the FHL short-harvest technique. The length of the osseous tunnel in the calcaneus was measured. At harvesting of the FHL tendon, the length of the tendon that traverses the osseous tunnel was measured with the ankle in neutral and maximal plantarflexion from the tip of the osseous tunnel to the transected end of the tendon within the bone tunnel. The mean length of the osseous tunnel was 42.7 ± 2.3 (range 38 to 46) mm. With the ankle in neutral position, the mean length of the FHL tendon traversing the bone tunnel was 31 ± 1.7 (range 29 to 34) mm. This mean length increased to 38.8 ± 1.6 (range 36 to 41) mm with the ankle placed in maximal plantarflexion. The ratio of the mean length of the tendon graft to the mean length of the osseous tunnel with the ankle in neutral was 0.727 ± 0.046 (range 0.667 to 0.81), and the ratio was 0.91 ± 0.042 (range 0.864 to 0.976) when the ankle was maximally plantarflexed. To the best of our knowledge, we report for the first time that the short-harvest technique provides >70% (ratio 0.727) of the FHL tendon graft in the osseous tunnel at all times, even when then ankle is in neutral, resulting in sufficient tendon length for FHL tendon transfer to the calcaneus for chronic Achilles tendon rupture.

Screw oversizing for anterior cruciate ligament graft fixation in primary and enlarged tibial tunnels: A biomechanical study in a porcine model

BackgroundIdeal diameter for tibial interference screw fixation of the anterior cruciate ligament (ACL) graft remains controversial. Tibial graft fixation with screws matching the tunnel diameter vs. one-millimetre oversized screws were compared. MethodsIn 32 cadaveric porcine tibiae, bovine extensor tendons with a diameter of eight millimetres were fixed in (I) a primary ACL reconstruction scenario with eight-millimetre tibial tunnels (pACL), with eight-millimetre (pACL-8) vs. nine-millimetre (pACL-9) screws, and (II) a revision ACL reconstruction scenario with enlarged tunnels of 10 mm (rACL), with 10-mm (rACL-10) vs. 11-mm (rACL-11) screws. Specimens underwent cyclic loading with low and high load magnitudes followed by a load-to-failure test. Graft slippage and ultimate failure load were recorded. ResultsIn comparison with matched-sized screws (pACL-8), fixation with oversized screws (pACL-9) showed with significantly increased graft slippage during cyclic loading at higher load magnitudes (1.19 ± 0.23 vs. 1.98 ± 0.67 mm; P = 0.007). There were no significant differences between the two screw sizes in the revision scenario (rACL-10 vs. rACL-11; P = 0.38). Graft fixation in the revision scenario resulted in significantly increased graft slippage in comparison with fixation in primary tunnels at higher loads (pACL vs. rACL; P = 0.004). Pull-out strengths were comparable for both scenarios and all screw sizes (P > 0.316). ConclusionsMatched-sized interference screws provided better ACL graft fixation in comparison with an oversized screw diameter. In revision cases, the fixation strength of interference screws in enlarged tunnels was inferior to the fixation strength in primary tunnels.

Biomechanical Comparison of Epiphyseal Anterior Cruciate Ligament Fixation Using a Cortical Button Construct Versus an Interference Screw and Sheath Construct in Skeletally Immature Cadaveric Specimens.

Background:Anterior cruciate ligament (ACL) ruptures have become increasingly common in pediatric and adolescent athletes. While multiple methods exist, all-epiphyseal ACL reconstruction is a popular technique in the skeletally immature patient. Given the high rate of reruptures in this population and the increasing number of commercially available fixation devices, biomechanical testing is crucial to understand the performance of these devices in pediatric epiphyseal bone. To our knowledge, there has not been a biomechanical analysis of ACL fixation devices in skeletally immature bone.Purpose:To compare cortically based button fixation with interference screw and sheath fixation in skeletally immature femoral epiphyseal cadaveric bone. Our hypothesis was that there would be no difference in peak load to failure, stiffness, or cyclic displacement between these 2 fixation constructs.Study Design:Controlled laboratory study.Methods:Fresh-frozen matched-pair knees from 3 pediatric cadaveric specimens were obtained. A synthetic graft was fixed in an all-epiphyseal femoral tunnel. Both the lateral and medial condyles were utilized to increase the sample size. Specimens were randomized and assigned to receive either an interference screw and sheath construct designed for pediatric patients or an adjustable loop cortical button. Biomechanical testing was performed to obtain ultimate load to failure, stiffness, total displacement after 500 cycles, and the failure mode for each condyle.Results:Each medial and lateral condyle in 3 pairs of skeletally immature cadaveric knees (ages 7, 9, and 11 years) was utilized for testing. One specimen was excluded after it failed by having a transphyseal fracture. The median peak load to failure was 769.80 N (interquartile range [IQR], 628.50-930.41 N) for the screw and sheath group and 862.80 N (IQR, 692.34-872.65 N) for the button group (P = .893). The median displacement after 500 cycles for the screw and sheath group was 0.65 mm (IQR, 0.47-1.03 mm) and 1.13 mm (IQR, 0.96-1.25 mm) for the button group (P = .08). The median stiffness of the screw and sheath group was significantly higher than that of the button group (31.47 N/mm [IQR, 26.40-43.00 N/mm] vs 25.22 N/mm [IQR, 21.18-27.07 N/mm], respectively) (P = .043).Conclusion:When comparing femoral fixation with a screw and sheath construct developed for pediatric patients to an adjustable loop cortical button in skeletally immature bone, our results showed that fixation did not significantly differ with respect to cyclic displacement or peak load to failure. While the screw and sheath construct was significantly stiffer, its effect on clinical outcomes is not yet known.Clinical Relevance:With regard to femoral fixation, there is no significant biomechanical difference between the use of cortically based button fixation or interference screw and sheath fixation in pediatric epiphyseal cadaveric bone.

Interference Screw Versus Suture Endobutton Fixation of a Fiber-Reinforced Meniscus Replacement Device in a Human Cadaveric Knee Model

Background: Meniscal lesions represent one of the most common intra-articular knee injuries. Meniscus replacement devices are needed to restore load distribution and knee stability after meniscectomy. Fixation of these devices is crucial to the generation of hoop stresses and the distribution of loads in the joint. Purpose: To evaluate 2 different fixation techniques (suture endobutton and interference screw) for implantation of a novel meniscus device. Study Design: Controlled laboratory study. Methods: In 7 human cadaveric knees (aged 17-61 years), 1 anterior and 2 potential posterior tunnel locations were investigated, and both fixation techniques were tested in each tunnel. The native meniscus roots, devices fixed with a suture endobutton, and devices fixed with an interference screw were gripped with cryoclamps, and tibias were drilled and loaded into a custom jig. Samples were preloaded, preconditioned, loaded for 500 cycles (50-150 N), and tested in tension until failure. Results: For all 3 tunnels, suture fixation resulted in greater elongation (54.1%-150.7% greater; P < .05) during cyclic loading than interference screw fixation, which approximated the native roots. Both fixation techniques displayed ultimate tensile loads in the same range as native roots. However, stiffness of the suture fixation groups (36.5-41.6 N/mm) was only 28% to 37% of that of the interference screw fixation groups (98.7-131.6 N/mm), which had values approaching those of the native roots (anterior: 175.4 ± 24.2 N/mm; posterior: 157.6 ± 22.9 N/mm). Conclusion: Interference screw fixation was found to be superior to suture fixation with regard to elongation and stiffness, a finding that should be considered in the design and implantation of novel meniscus replacement devices. Clinical Relevance: With the emergence of various devices for total meniscus replacement, the establishment of fixation strategies is crucial for the generation of tensile hoop stresses and the efficacy of these approaches.

Biomechanical properties of suprapectoral biceps tenodesis: double knotless screw fixation is superior to single knotless screw fixation.

The purpose of this study is to biomechanically evaluate a new technique of double knotless screw fixation for suprapectoral biceps tenodesis and compare the results with that of the single knotless screw fixation as well as the interference screw fixation. 24 fresh-frozen human cadaveric shoulders with a mean age of 68.3 ± 9years were studied. The specimens were randomly divided into three experimental biceps tenodesis groups (n = 8): single knotless screw, double knotless screw and interference screw. Each tenodesis specimen was mounted on a mechanical testing machine, preloaded for 2min at 5N, tested with cyclic loading from 5 to 70N for 500 load cycles and subjected to an axial load to failure test (1mm/s). The ultimate failure load, stiffness, cyclic displacement and mode of failure were evaluated. The interference screw fixation had the highest ultimate failure load (215.8 ± 43.1N) and stiffness (25.7 ± 5.2N/mm) which were significantly higher than the corresponding results for the single and double knotless screw groups (P = 0.0029). The double knotless screw group had the second highest ultimate failure load (162.8 ± 13.8N) and stiffness (15.1 ± 4.1N/mm) which were significantly higher than the corresponding results for the single knotless screw technique (P = 0.0002). The most common mode of failure was suture slippage for both the double (7/8) and single knotless screw (6/8) groups while biceps tendon tearing occurred most often for the interference screw group (6/8). In this biomechanical study, the double knotless screw fixation was found to have a significantly greater ultimate failure load and stiffness than the single knotless screw fixation but lower values than the interference screw fixation.