Press-fit Fixation Technique Research Articles

Tibial Press-Fit Fixation Technique in Anterior Cruciate Ligament Reconstruction Surgery

Implant-free press-fit tibial fixation technique has recently gained popularity in anterior cruciate ligament reconstruction because it does not cause tunnel widening, does not cause complications associated with additional fixation materials, allows bone-to-bone healing, and does not cause defects in revision surgery. Bone-patellar tendon autograft offers the advantage of direct bone-to-bone integration of the graft, and anterior knee pain is less expected than bone-patellar tendon-bone autograft. This technical report includes details of arthroscopic ACL reconstruction of patellar tendon-tibial tubercle bone autograft distal press-fit fixation technique. We call this the Kocabey distal press-fit technique.

Low Femoral Tunnel Widening Incidence Rate After ACL Reconstruction Using Patellar Tendon Graft with Press-Fit Fixation

BackgroundFemoral tunnel widening after ACL reconstruction is a common phenomenon. We hypothesized that using a patellar tendon graft with a press-fit fixation technique without any fixation device reduces the incidence of femoral tunnel widening.MethodsThis study was conducted on 467 patients with ACL surgery between 2003 and 2015. Two hundred and nineteen of them had an ACL surgery with patellar tendon (PT) graft, and two hundred and forty-eight of them with hamstring tendon (HS). Exclusion criteria were history of previous ACL reconstruction of either knee, multiple ligament injury, or evidence of osteoarthritis on radiographs. The femoral tunnels were measured on the anteroposterior (ap) and lateral radiographs 6 months after the operation. Two independent orthopedic surgeons measured all radiographs twice and recorded the tunnel widenings. We hypothesized that using an implant-free press-fit technique with PT graft can reduce the femoral tunnel widening incidence rate.ResultsThe mean incidence rate of the tunnel widening in the HS group was, on the AP and the lateral femoral views, 88% (n = 217) and 83% (n = 205), while in the PT group, 17% (n = 37) and 2% (n = 4), respectively. There was a significant difference both on AP and lateral radiographs (HS vs. PT: fem. AP: 89% vs. 17% p < 0.001; HS vs. PT: fem. lat: 84% vs. 2% p < 0.001).ConclusionThe femoral tunnel widening incidence rate during an ACL reconstruction is significantly less when using PT tendon with femoral press-fit fixation than when using HT tendon with suspensory fixation method.

Comparing Knee Laxity After Anatomic Anterior Cruciate Ligament Reconstruction Using Quadriceps Tendon Versus Semitendinosus Tendon Graft.

Background:The choice of graft in anterior cruciate ligament (ACL) reconstruction is still under discussion. The hamstrings are currently the most used grafts for primary ACL reconstruction in Europe. However, increased interest has arisen in the quadriceps tendon (QT) as an alternative autologous graft option for primary ACL reconstruction.Purpose:To evaluate knee stability and the subjective outcome after ACL reconstruction using either autologous QT graft in implant-free femoral press-fit fixation technique or semitendinosus tendon (ST) graft.Study Design:Cohort study; Level of evidence, 2.Methods:We evaluated 50 patients who underwent ACL reconstruction, including 25 patients who received autologous ipsilateral QT graft (QT group) and 25 patients who received the ipsilateral ST graft (ST group). The follow-up for this prospective comparative study was at least 2 years after surgery, comprising KT-1000 arthrometer testing, pivot-shift test, Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm score, and rerupture rate.Results:The mean patient age was 31.72 years (9 women, 16 men) in the QT group and 32.08 years (13 women, 12 men) in the ST group. The mean ± standard deviation postoperative side-to-side difference assessed using KT-1000 arthrometer was 1.56 ± 1.56 mm for the QT group and 1.64 ± 1.41 mm for the ST group, with no significant difference. No significant difference was found on any of the KOOS subscale scores (P = .694) or the Lysholm score (P = .682). No rerupture or positive pivot-shift test occurred during follow-up. No difference was found in donor-site morbidity between the study groups.Conclusion:Clinical outcomes were not significantly different between QT and ST grafts in the current study. Thus, the QT may serve as a good alternative graft for primary ACL reconstruction.

Functional outcome of implant-free bone-patellar tendon autograft versus hamstring autograft in arthroscopic anterior cruciate ligament reconstruction: A prospective study

IntroductionThe use of implant in anterior cruciate ligament (ACL) reconstruction has been associated with several drawbacks including graft injury, implant osteolysis, implant migration and soft tissue irritation. Implant-free ACL reconstruction surgery offers additional benefits of cost-effective, improved graft incorporation and ease of revision surgery. Our study aimed to compare the functional outcome of ACL reconstruction by using bone-patellar tendon autograft with press-fit fixation technique and hamstring autografts with implant. MethodsA prospective cohort study design was used. Between March 2013 and March 2014, 12 patients underwent patella tendon-bone graft fixated by press-fit fixation technique (implant-free), while 24 patients underwent ACL reconstruction using implant-fixated hamstring tendon graft. Objective functional outcome was measured by using rolimeter, and subjective functional outcome was measured according to the functional score of IKDC, Tegner-Lysholm and KOOS. ResultsBoth techniques have shown no significant difference in terms of functional outcome, whether assessed by rolimeter measurement, IKDC score, Tegner-Lysholm, KOOS score between implant group and implant-free group, preoperatively and postoperatively. DiscussionOur study results are in line with several other studies with various follow-up time and systematic review. With the right technique, graft harvesting of patella tendon-tibial tuberosity bone block can be successfully performed, and associated donor site morbidity can be avoided. ConclusionPatients who underwent ACL reconstruction using implant-free technique by press-fit fixation had comparable outcome with ACL reconstruction with implant, objectively and subjectively. This technique should be further revisited and reevaluated.

Quadriceps tendon vs. patellar tendon autograft for ACL reconstruction using a hardware-free press-fit fixation technique: comparable stability, function and return-to-sport level but less donor site morbidity in athletes after 10\xa0years

IntroductionThe use of quadriceps tendon–patellar bone (QTB) autograft for anterior cruciate ligament (ACL) reconstruction is gaining momentum. Yet, long-term results that compare this procedure with established methods are lacking. The aim of this study was to report and compare long-term results of ACL reconstruction using QTB autografts versus bone–patellar tendon–bone (BPTB) autografts, both anchored using a hardware-free press-fit fixation technique.Materials and methods60 athletes (Tegner score ≥6) with primary ACL rupture were prospectively randomized into two groups. 56 patients were evaluated after a mean duration of 12.2 ± 1.9 months (range 10–14) and 43 patients after 10.3 ± 0.2 years (range 10–11).ResultsOn final follow-up, 90% of patients scored very good and good results in the functional Lysholm score (mean 99 ± 7.1, range 74–100 points). Normal or almost normal IKDC score was reported by 84% of the patients (mean 97 ± 9.5, range 60–100 points). The activity level decreased in the Tegner score from median of 7 before injury to 6 after 10 years. The KT-1000 arthrometer showed a difference in the anterior translation of less than 3 mm (mean 1.0 ± 1.2, range − 1 to 5 mm) in 91% of the patients. Significant degeneration was radiologically detected in one patient per group. No tunnel widening was seen in any patient. Up to 97% of all patients were satisfied with the operative procedure. No significant differences were found in the mentioned parameters between the two groups and also in comparison with the 1-year results. The only significant difference was in the donor site morbidity. Significantly more patients in the BPTB group had complaints during kneeling both at 1 (p < 0.001) and 10 years (p = 0.019). Squatting was also subjectively more problematic in the BPTB group than in the QTB group both after 1 (p = 0.003) and 10 years (p = 0.046).ConclusionsThis study shows equally good functional, clinical and radiological long-term results for both hardware-free methods of ACL reconstruction. These results clinically confirm the safety of press-fit anchoring after 10 years. The failure rate in this study was very low, with only one re-rupture in 10 years. The increased donor site morbidity when using the BPTB autograft compared to the QTB autograft supports already reported data. It was also seen in this study for the implant-free press-fit techniques.Study designProspective and randomized, level of evidence 2.

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.

The biomechanical strength of a hardware-free femoral press-fit method for ACL bone-tendon-bone graft fixation.

The purpose was to investigate graft slippage and ultimate load to failure of a femoral press-fit fixation technique for anterior cruciate ligament (ACL) reconstruction. Nine fresh-frozen knees were used. Standardized harvesting of the B-PT-B graft was performed. The femora were cemented into steel rods, and a tunnel was drilled outside-in into the native ACL footprint and expanded using a manual mill bit. The femoral bone block was fixed press-fit. To pull the free end of the graft, it was fixed to a mechanical testing machine using a deep-freezing technique. A motion capture system was used to assess three-dimensional micro-motion. After preconditioning of the graft, 1000 cycles of tensile loading were applied. Finally, an ultimate load to failure test was performed. Graft slippage in mm ultimate load to failure as well as type of failure was noted. In six of the nine measured specimens, a typical pattern of graft slippage was observed during cyclic loading. For technical reasons, the results of three knees had to be discarded. 78.6% of total graft slippage occurred in the first 100 cycles. Once the block had settled, graft slippage converged to zero, highlighting the importance of initial preconditioning of the graft in the clinical setting. Graft slippage after 1000 cycles varied around 3.4±3.2mm (R=1.3-9.8mm) between the specimens. Ultimate loading (n=9) revealed two characteristic patterns of failure. In four knees, the tendon ruptured, while in five knees the bone block was pulled out of the femoral tunnel. The median ultimate load to failure was 852N (R=448-1349N). The implant-free femoral press-fit fixation provided adequate primary stability with ultimate load to failure pull forces at least equal to published results for interference screws; hence, its clinical application is shown to be safe.

A biomechanical assessment of fixation methods for a coronoid prosthesis

BackgroundThe coronoid process is an integral component for maintaining elbow joint stability. When fixation of a fracture is not possible, prosthetic replacement may be a feasible solution for restoring stability. The purpose of this in-vitro biomechanical study was to compare fixation methods for a coronoid implant. MethodsA coronoid prosthesis was subjected to distally-directed tip loading after implantation using four fixation methods: press-fit, anterior-to-posterior screws, posterior-to-anterior screws, and cement. Testing was performed on seven fresh-frozen ulnae in a repeated-measures model. Rounds of cyclic loading were applied at 1Hz, for 100cycles, increased in 50N increments up to a maximum of 400N. Micro-motion of the implant was quantified using an optical-tracking system. Outcome variables included total displacement, distal translation, gapping, anterior translation and axial stem rotation. FindingsCement fixation reduced implant micro-motion compared to screw fixation, while the greatest implant micro-motion was observed in press-fit fixation. Comparing screw-fixation techniques, posterior–anterior screws provided superior stability only in distal translation. The implant did not experience displacements exceeding 0.9mm with screw or cement fixation. InterpretationCement fixation provides the best initial fixation for a coronoid implant. However, the stability provided by both methods of screw fixation may be sufficient to allow osseous integration to be achieved for long-term fixation. Large displacements were observed using the press-fit fixation technique, suggesting that modifications would need to be developed and tested before this technique could be recommended for clinical application.

Femoral press-fit fixation in ACL reconstruction using bone-patellar tendon-bone autograft: results at 15 years follow-up

BackgroundIf anterior cruciate ligament (ACL) reconstruction is to be performed, decision regarding graft choice and its fixation remains one of the most controversial. Multiple techniques for ACL reconstruction are available. To avoid disadvantages related to fixation devices, a hardware-free, press-fit ACL reconstruction technique was developed.The aim of this study was to evaluate clinical outcome and osteoarthritis progression in long term after ACL reconstruction with central third patellar-tendon autograft fixed to femur by press-fit technique.MethodsFifty two patients met inclusion/excusion criteria for this study. The patients were assessed preoperatively and at 15 years after surgery with International Knee Documentation Committee Knee Ligament Evaluation Form, Lysholm knee score, Tegner activity scale and radiographs.ResultsGood overall clinical outcomes and self-reported assessments were documented, and remained good at 15 years. The mean Lysholm and Tegner scores improved from 59.7 ± 18.5 and 4.2 ± 1.0 preoperatively to 86.4 ± 5.6 (p = 0.004) and 6.9 ± 1.4 (p = 0.005) respectively at follow-up. The IKDC subjective score improved from 60.1 ± 9.2 to 80.2 ± 8.1 (p = 0.003).According to IKDC objective score, 75% of patients had normal or nearly normal knee joints at follow-up. Grade 0 or 1 results were seen in 85% of patients on laxity testing. Degenerative changes were found in 67% of patients. There was no correlation between arthritic changes and stability of knee and subjective evaluation (p > 0.05).ConclusionsACL reconstruction with patellar tendon autograft fixed to femur with press-fit technique allows to achieve good self-reported assessments and clinical ligament evaluation up to 15 years. Advantages of the bone-patellar-tendon-bone (BPTB) press-fit fixation include unlimited bone-to-bone healing, cost effectiveness, avoidance of disadvantages associated with hardware, and ease for revision surgery. BPTB femoral press-fit fixation technique can be safely applied in clinical practice and enables patients to return to preinjury activities including high-risk sports.

Fremdmaterialfreie vordere Kreuzbandplastik mit der Patellasehne in Press-fit-Doppelbündeltechnik

Anterior cruciate ligament (ACL) reconstruction using autologous tendons (BTB patellar tendon, hamstrings, quadriceps tendon) in an implant-free fixation technique is becoming more and more popular due to biological and economical reasons. In 1987 an implant-free press-fit fixation technique of a BTB graft from the medial side of the patellar tendon (via mini-arthrotomy) was introduced and first published during the 4th ESKA Conference 1990 in Stockholm. Special emphasis is given to the anatomical orientation of the BTB graft. During the inside-out femoral press-fit fixation the bone-ligament margin of the graft is placed directly into the femoral insertion line of the natural ACL adapting its double-bundle structure. The graft is fixed by press-fit within the tibial metaphysis and its ligamentous part is secured in the metaphysis by harvested cancellous bone blocks driven into the joint line from the outside. The postoperative regime includes weight-bearing as tolerated and free motion. Out of 159 patients 95 could be seen for follow-up after an average of 10.7 years. The final IKDC knee score revealed 22.1% in group A (very good) and 62.1% in group B (good). The Tegner activity level was 6.8 preinjury and 6.0 postoperatively. The average KT 1,000 side-to-side difference was 1.8 mm. Subjectively no patient complained of instability and 99% of the patients could kneel on hard ground with minimal or no complaints. ACL revision surgery due to graft failure was not necessary in any of the patients. Advantages of the described procedure are a narrow anatomical orientation including the double bundle structure of the ACL, rapid graft incorporation by bone-to-bone healing, lack of bone resorption at the graft-host interface, decreased donor site morbidity, cost-effectiveness and ease of possible revision surgery.

The effect of bone tunnel dilation versus extraction drilling on the initial fixation strength of press-fit anterior cruciate ligament reconstruction

Serial dilation of the bone tunnel has been reported to create a tighter graft-tunnel fit. It was hypothesized that a serial dilation of the femoral bone tunnel would increase the initial fixation strength in press-fit anterior cruciate ligament (ACL) reconstructive surgery. Initial fixation strength of the femoral press-fit fixation technique was investigated in 72 porcine specimens in an ex vivo study by varying the femoral tunnel preparation technique. Extraction-drilling, tunnel dilation by 1 mm and dilation by 2.5 mm were assessed. Initial fixation strength of press-fit fixated patellar tendon-bone grafts was tested within each preparation group conducting a single cycle (and cyclic) load to failure protocol. The resulting tunnel diameter and the porcine femoral bone mineral density were determined using microradiographs and peripheral quantitative CT scans, respectively. Dilating a previously extraction-drilled femoral bone tunnel by 1 mm significantly enhances initial press-fit fixation strength in both single cycle and cyclic load to failure testing when compared to extraction-drilling and tunnel dilation by 2.5 mm. Due to an initial spring-back effect the resulting diameter of the femoral tunnel was underestimated by 3.3% with drilling and 6.7 and 12.2% with dilation by 1 and 2.5 mm, respectively. Volumetric trabecular bone mineral density at the site corresponding to the area of tunnel placement averaged 318 mg/cm(3). Dilating a femoral tunnel that is underdrilled by 1 mm appears to be a reasonable technical procedure in order to enhance initial fixation strength of press-fit ACL graft fixation.

Femoral Press-Fit Fixation Technique in Anterior Cruciate Ligament Reconstruction Using Bone-Patellar Tendon-Bone Graft

Background The security of the graft fixation is an important factor of anterior cruciate ligament reconstruction, especially in the early postoperative period. Hypothesis The femoral press-fit fixation technique is a safe, alternative technique for the fixation of the bone-patellar tendon-bone graft. Study Design Case series; Level of evidence, 4. Methods Between January 1, 1998, and June 30, 2002, 285 patients, with a mean age of 29.1 years, underwent operation and observation in our department. All patients had arthroscopic anterior cruciate ligament reconstruction using bone-patellar tendon-bone graft with femoral press-fit and tibial interference screw fixation. The mean follow-up period was 35.8 months (range, 24-77 months). During each patient's evaluation, a physical examination, a subjective evaluation, the International Knee Documentation Committee and Lysholm scores, KT-1000 arthrometer testing, and radiological evaluation were performed. The paired Student t test or X2 test was used for statistical analysis. Results According to the International Knee Documentation Committee score, 241 patients (85%) had good (46 normal and 195 nearly normal) results, whereas 39 patients had abnormal and 5 patients had severely abnormal overall results. The preoperative mean Lysholm score was 63.5 ± 12.7 points. At the final examination, the mean value was 93.5 ± 7.8 points (P <. 01). One hundred ninety-seven athletes could return to their previous sports activity level, whereas 13 patients gave up their sports career. The KT-1000 arthrometer results showed a side-to-side difference of 1.91 ± 2.1 mm at the maximum manual strength tests. Conclusion The femoral press-fit fixation is an alternative fixation method for the bone-patellar tendon-bone graft and provides good stability for the anterior cruciate ligament reconstruction. The use of press-fit fixation technique avoids most interference screw or other hardware-induced complications at the femoral side.

Biomechanical testing of quadriceps tendon–patellar bone grafts: an alternative graft source for press-fit anterior cruciate ligament reconstruction?

Press-fit fixation of bone-patellar tendon-bone (BPTB) grafts in anterior cruciate ligament (ACL) reconstruction has been analyzed biomechanically in previous studies; however, the use of quadriceps tendon-patellar bone (QTPB) grafts has not been studied so far. It is hypothesized that QTPB grafts provide primary fixation strength comparable to BPTB grafts in press-fit ACL reconstruction with respect to bone plug length and loading angle. Fifty-two QTPB grafts were harvested from fresh human cadaver knees (mean age 73.3 years) with the length of the patellar bone plug being either 15 mm (Group I) or 25 mm (Group II). The grafts were anchored within fresh porcine femora (mean age 12 months) using a press-fit fixation technique. Forty-eight specimens were loaded to failure at 10 mm/s with varying loading angles of 0 degrees , 30 degrees , and 60 degrees until failure. A microradiographic pre-post-implantation analysis was conducted on four grafts. The biomechanical testing showed a significant difference in the ultimate failure loads comparing Group I (mean 224+/-79.3 N) to Group II (mean 339+/-61.4 N), both showing mean ultimate failure loads to increase with rising loading angle. The predominant mode of failure was graft pullout at axial loading and tendon rupture at 60 degrees loading angle. The microradiographic analysis revealed an iatrogenic damage of the bone-tendon junction on the cancellous aspect of the bone plug in all trials, corresponding with the site of impactor placement during implantation. QTPB grafts provide a loading capability comparable to BPTB grafts in press-fit ACL reconstruction. The broad and profound area of quadriceps tendon attachment to the patellar bone plug makes graft implantation demanding.

Bone plug length and loading angle determine the primary stability of patellar tendon-bone grafts in press-fit ACL reconstruction

The present study was conducted to evaluate the influence of bone-plug length on the primary stability of patellar tendon-bone grafts, using a femoral press-fit fixation technique. Forty-eight human PTB grafts with a patellar bone-plug length of 15 mm and 25 mm were obtained from 24 human cadavers (mean age 72 years) and implanted to porcine femora in a press-fit fixation technique. Tensile loading was performed at 10 mm/s until failure at varying loading angles of 0 degrees, 30 degrees and 60 degrees. Compared to 25 mm, a significant decrease of primary graft stability was recorded in the testing of 15-mm bone plugs. For both plug lengths, the ultimate load to failure increased with rising the loading angles. While axial graft loading exclusively caused plug dislocation, the predominant mode of failure was tendon rupture at 60 degrees loading angle. We conclude that 15-mm bone plugs do not result in a sufficient stability for early aggressive rehabilitation and therefore 25-mm bone plugs are recommended for the femoral press-fit technique.

Histomorphology and microradiography of quadriceps tendon–patellar bone grafts in press-fit anterior cruciate ligament reconstruction

The press-fit fixation technique has become an alternative fixation method in anterior cruciate ligament (ACL) reconstruction. While the stability of press-fit fixated grafts reported in the literature predominantly had been analysed by biomechanical testing, this study investigated the specific histomorphologic and microradiographic features important for graft stability, using human quadriceps tendon–patellar bone (QTPB) grafts. Six QTPB grafts with cylindrical bone plugs were obtained from frozen fresh human cadaver knees and fixed to porcine, bovine, or human femora in a press-fit technique. The specimens were plastinated, dissected into 1.5 mm slices, studied microradiographically and stained for histologic evaluation. The specimens showed an osseous inclusion of the graft within the femoral tunnel, which was most evident on the cancellous side. Histologic analysis revealed a trabecular interdigitation with a penetration of patellar and femoral trabecular structures, contributing to primary stability of the press-fit fixation. Graft inclusion was most obvious in bovine and least in human femora, assumably because of varying bone quality. The circular bone-to-bone contact in press-fit fixation technique should contribute to both rapid and stable graft healing.