Biomechanical comparison of different fixation techniques for reconstruction of tibial avulsion fractures of the anterior cruciate ligament

Screw placement through a higher medial portal provides better initial stability in arthroscopic ACL tibial avulsion fracture fixation: a finite element analysis

OBJECTIVE

The objective of this study was to investigate the initial stability of different screw placements in arthroscopic anterior cruciate ligament (ACL) tibial avulsion fracture fixation.

METHODS

A three-dimensional knee model at 90° flexion was utilized to simulate type III ACL tibial avulsion fracture and arthroscopic screw fixation through different portals, namely the central transpatellar tendon portal (CTP), anterolateral portal (ALP), anteromedial portal (AMP), lateral parapatellar portal (LPP), medial parapatellar portal (MPP), lateral suprapatellar portal (LSP), medial suprapatellar portal (MSP). A shear force of 450 N was applied to the finite element models at 30° flexion to simulate the failure condition. The displacement of the bony fragment and the volume of the bone above 25,000 µ-strain (damaged bone volume) were calculated around the screw path.

RESULTS

When the screw was implanted through CTP, the displacement of the bony fragment reached the maximum displacement which was 1.10 mm and the maximum damaged bone volume around the screw path was 148.70 mm3. On the other hand, the minimum displacement of the bony fragment was 0.45 mm when the screw was implanted through LSP and MSP. The minimum damaged bone volume was 14.54 mm3 around the screw path when the screw was implanted through MSP.

CONCLUSION

Screws implanted through a higher medial portal generated less displacement of the bony fragment and a minimum detrimental strain around the screw path. The findings are clinically relevant as they provide biomechanical evidence on optimizing screw placement in arthroscopic ACL tibial avulsion fracture fixation.

The Arthroscopic Three-Point Fixation for Anterior Cruciate Ligament Avulsion Fracture: Surgical Technique

Several arthroscopic repairs and fixation for tibial intercondylar eminence fracture have been developed for restoring anterior cruciate ligament function. Repairing the avulsion fragment with multiple-point fixation provides some benefits over a single-point fixation. It provides multidirectional force control, especially on the posterior part of the fragment, and produces area of compression. We propose a 3-point fixation technique for providing proper reduction and compression in large fragment anterior cruciate ligament avulsion fracture. This includes using hybrid intra-articular and tunnel pull-out suture fixation to provide good posterior reduction and fixation. The number of tunnels is decreased by using a suture anchor.

Adjustable-Loop Cortical Button Fixation Results in Good Clinical Outcomes for Acute Tibial Avulsion Fracture of the Posterior Cruciate Ligament

Purpose

To evaluate the clinical outcomes for arthroscopic treatment of acute posterior cruciate ligament (PCL) avulsion fractures with adjustable-loop cortical button fixation device.

Methods

Patients with PCL tibial avulsion fractures treated with an adjustable-loop cortical button fixation device between October 2019 and October 2020 were retrospectively identified. Patients with type 1 were treated using plaster fixation as a conservative treatment, whereas patients with type 2 and 3 with displacement were treated using an arthroscopic adjustable-loop cortical button. Operating time, incision recovery, complications, and postoperative fracture healing time were monitored. All patient follow-up was done at 12 months' postoperatively. Lysholm Knee Score and the International Knee Documentation Committee score were used to assess knee function.

Results

A total of 30 patients were included in the study (20 male/10 female; mean age 45.5 years, range 35-68 years). The mean operative time was 67.5 minutes (range: 50-90 minutes). The postoperative incision healed at stage A without complications, such as medically induced vascular nerve injury, intra-articular hematoma, or infection. All 30 patients were tracked postoperatively for 12 to 14 months, with a mean follow-up period of 12.6 months. The Lysholm knee function score was 45.93 ± 6.15 before surgery and 87.10 ± 3.71 at 12 months after surgery, and the International Knee Documentation Committee score was 19.27 ± 4.40 before surgery and 95.47 ± 1.87 at 12 months after surgery, with a statistically significant difference.

Conclusions

The treatment of PCL avulsion fractures with arthroscopic adjustable-loop cortical button fixation is easy to perform and shows good clinical results in our study.

Level of Evidence

IV, therapeutic case series.

A New Arthroscopic Tightrope Suture-Button Fixation Procedure for Tibial Eminence Avulsion Fracture

This case-series outcome study presents a new arthroscopic technique for tibial eminence avulsion fracture (TEAF) with double-tunnel using two tightrope suture buttons. From May 2017 to July 2020, we performed a new arthroscopic technique for TEAF with double tunnels, using two tightrope suture buttons on 13 patients. Clinical assessments included anterior drawer, Lachman, and pivot shift tests, the International Knee Documentation Committee (IKDC), Lysholm knee scores, visual analog scale (VAS) scores, and range of motion (ROM). An independent observer noted conditions before surgery and during the last follow-up. The patients had an average follow-up of 26.2 months, ranging from 15 to 37 months. During the last postsurgical follow-up, the anterior drawer, Lachman, and pivot shift tests were negative in all the cases. According to the IKDC, Lysholm, and VAS final scores, all patients presented a significant knee function improvement at last follow-ups compared with preoperatively. The study shows that satisfactory results about an anatomic reduction of the fragment, knee stability, function, and strength can be achieved with the new arthroscopic technique for TEAF with double tunnels using two tightrope suture buttons. This study is a therapeutic case series and its level of evidence is IV.

Biomechanical Comparisons of Anterior Cruciate Ligament Avulsion Fracture Fixation Using High-Strength Suture and Ultra-High Molecular Weight Polyethylene Suture Tape in a Porcine Model

A wide variety of fixation methods have been reported to fix anterior cruciate ligament (ACL) tibial avulsion fractures, but there have been no studies into the fixation of these fractures with ultra-high molecular weight polyethylene (UHMWPE) suture tape as an alternative to conventional thread. Type III ACL tibial avulsion fractures were created in 20 skeletally immature porcine knees. All specimens were randomized into two treatment groups: (1) pullout repair using no. 2 suture fixation and (2) pullout repair using UHMWPE suture tape fixation. The specimens were tested cyclically (20 cycles, 0-40 N, 100 mm/min) in the direction of the native ACL and loaded to failure (100 mm/min) on a tensile tester. Statistically significant differences between the structural properties (displacement, upper yield load, maximum load, linear stiffness, and elongation at failure) under cyclic loading and single-cycle loading were analyzed. Displacement during cyclic testing was 1.56 ± 1.03 mm in the UltraBraid group and 0.99 ± 0.48 mm in the SUTURETAPE group, with no significant differences found between the groups (p = 0.13). There were no significant differences in upper yield load (161.9 ± 68.9 N in the UltraBraid group, 210.4 ± 60.1 N in the SUTURETAPE group, p = 0.11), linear stiffness (14.7 ± 4.7N/mm in the UltraBraid group, 18.1 ± 7.9 N/mm in the SUTURETAPE group, p = 0.27), or elongation at failure (20.1 ± 8.0 mm in the UltraBraid group, 21.5 ± 7.2 mm in the SUTURETAPE group, p = 0.69). On the other hand, significant differences were observed in maximum load in the SUTURETAPE group (219.7 ± 89.2 N in the UltraBraid group, 319.3 ± 92.6 N in the SUTURETAPE group, p = 0.025).

Minimally Invasive Percutaneous TightRope® System Fixation for an Unstable Posterior Pelvic Ring: Clinical Follow-up and Biomechanical Studies

Objective

To evaluate the mechanical stability and clinical efficacy of minimally invasive percutaneous TightRope® systems applied via gun‐shaped reduction forceps for unstable posterior pelvic ring fractures.

Materials and methods

This study consists of two parts: a clinical retrospective study and a randomized controlled biomechanical test. For the clinical study, a retrospective analysis of posterior pelvic ring fractures was performed between June 2015 and May 2020. Eighteen patients underwent surgery using two TightRope® systems to fix a broken posterior pelvic ring because of unstable AO type C1 and C2 pelvic ring fractures. The patients were followed up for at least 2 years, and all patients were evaluated using the Majeed scoring system and vertical displacement. In the biomechanical tests, six embalmed adult pelvic specimens were used. The fractures were subjected to TightRope®, IS screw, and TBP fixation in a randomized block design. The specimens were placed in a biomechanical testing machine in a standing neutral posture. A cyclic vertical load of up to 500 N was applied, and the displacement of the specimens was recorded by the testing machine. The ultimate load in each group of specimens was recorded. The displacement and ultimate load were compared and analyzed by statistical methods.

Results

At a mean follow‐up of 38.89 ± 8.72 months, the functional Majeed score was excellent in 14 patients and good in four patients. The final radiological examinations showed that the outcome was excellent in 14 patients and good in four patients. In these patients, no serious clinical complications were found. Weight‐bearing was delayed in four patients. In biomechanical tests, the displacement of the specimens fixed with TightRope® was significantly lower than that of the specimens fixed with TBP (P < 0.05) when the load ranged from 300 to 500 N. The displacement in the IS screw group was significantly lower than that in either the TBP or TightRope® group (P < 0.05) when the load ranged from 0 to 500 N. The ultimate load in the IS screw group (1798 ± 83.53 N) was significantly greater than that in the TBP group (1352 ± 74.41 N) (t = 9.78, P < 0.0001) and the TightRope® group (1347 ± 54.28 N) (t = 11.11, P < 0.0001). However, no significant difference was observed between the TightRope® and TBP groups (t = 0.13, P = 0.90).

Conclusion

Percutaneous posterior TightRope® system shows strong stability in mechanical experiments and shows good results in clinical follow‐up while this system has certain advantages in lower surgical requirements and lower risk of related nerve and vascular structural damage.

Arthroscopic Two-Point Suture Bridge Fixation Technique for the Treatment of Anterior Cruciate Ligament Tibial Avulsion Fractures

This study aimed to present and evaluate a new arthroscopic technique that uses two-point suture fixation for anterior cruciate ligament (ACL) tibial avulsion fractures. A total of 15 patients diagnosed with ACL tibial avulsion fracture underwent arthroscopic suture fixation from November 2018 to October 2019 and were treated using two-point suture fixation. The patients were followed up and evaluated according to Lysholm scores, International Knee Documentation Committee (IKDC) subjective scores, Tegner activity level scales, anterior drawer testing, and KT-1000 arthrometer testing. The mean follow-up period was 18 months (12 to 24). All patients had a negative Lachman test and anterior drawer test at final follow-up and showed the radiological union of avulsion fracture at 12-week postoperative radiograph. The Lysholm score improved significantly postoperatively with a mean score of 94.26±3.63 (87 to 98; p < 0.001). The Tegner score improved significantly postoperatively from 3.61 ±1.37 to 7.14±1.51 (P < 0.001). The KT-1000 measured value decreased significantly postoperatively from 7.3±1.5 to 1.4 ±1.2 (P < 0.001). The IKDC category was abnormal or severely abnormal preoperatively, and all patients improved to normal or nearly normal at final follow-up. Arthroscopic treatment using the two-point suture fixation technique is effective for ACL avulsion fracture and can restore the function and stability of the knee joint.

[Comparison of early effectiveness of arthroscopic suture bridge technique and conventional double tunnel suture technique in treatment of avulsion fracture of posterior cruciate ligament insertion]

Objective

To compare the early effectiveness of arthroscopic suture bridge technique and conventional double tunnel suture technique in the treatment of avulsion fracture of posterior cruciate ligament (PCL) insertion.

Methods

Between June 2013 and December 2018, 62 patients with tibial avulsion fracture of PCL insertion that met the criteria were selected and randomly divided into trial group (using arthroscopic suture bridge technique) and control group (using conventional double tunnel suture technique), 31 cases in each group. There was no significant difference in gender, age, injured side, cause of injury, time from injury to operation, Meyers & McKeever classification, Kellgren-Lawrence classification, and preoperative knee range of motion, difference of posterior relaxation of bilateral knee joints, International Knee Documentation Committee (IKDC) score, and Lysholm score between the two groups ( P>0.05). The operation time and IKDC score, Lysholm score, knee range of motion, the difference of posterior relaxation of bilateral knee joints (measured by KT-2000 under knee flexion of 90° and 30 lbs) were recorded and compared between the two groups before operation and at 3 and 12 months after operation.

Results

Both groups successfully completed the operation, and the operation time of the trial group and the control group were (61.81±6.83) minutes and (80.42±4.22) minutes respectively, showing significant difference between the two groups ( t=12.911, P=0.000). All the incisions healed by first intention, and there was no wound infection and other early postoperative related complications. All patients were followed up 13-18 months (mean, 14.6 months). The fractures in both groups healed at 3 months after operation. No knee pain, limited movement, or other complications occurred. At 3 and 12 months after operation, the IKDC score, Lysholm score, knee range of motion, and the difference of posterior relaxation of bilateral knee joints in both groups were significantly improved when compared with preoperative ones, and further improved at 12 months after operation when compared with at 3 months after operation ( P<0.05). At each time point after operation, the above indexes and the grade of the difference of posterior relaxation of bilateral knee joints in the trial group were significantly better than those in the control group ( P<0.05).

Conclusion

Arthroscopic suture bridge technique in the treatment avulsion fracture of PCL insertion is simple and reliable, which can significantly improve the function and stability of the knee joint and obtain satisfactory early effectiveness.

Clinical outcomes of acute displaced posterior cruciate ligament tibial avulsion fracture: A retrospective comparative study between the arthroscopic suture and EndoButton fixation techniques

BACKGROUND

Tibial avulsion fracture of the posterior cruciate ligament is not rare in the clinic. Arthroscopic treatment is increasingly accepted, but the choice of fixation has been debated. This study aims to compare the clinical outcomes of suture and EndoButton fixation under arthroscopy for acute displaced posterior cruciate ligament avulsion fractures.

METHODS

A total 68 of 83 PCL tibial avulsion fracture cases from 2009 to 2016 were retrospectively reviewed. Some patients received arthroscopic suture initially, and later the others received arthroscopic EndoButton fixation. Associated lesions were treated if present. The Lysholm and International Knee Documentation Committee (IKDC) scores, KT-1000 arthrometry and plain radiography were evaluated at follow-up. The assessment data at two years of follow-up were used for comparing the two different fixation groups.

RESULTS

The follow-up time of 63 patients was more than 2 years. In total, 32 of the 63 patients were in the suture group, and 31 were in the EndoButton group. At two years of follow-up, knee function according to the Lysholm score was a mean of 92.5 with a 95% confidence interval [CI] of 89.45 to 96.40 in the suture group and a mean of 93.5 with a 95% CI of 90.52 to 97.28 in the EndoButton group (P=.785). More than 90% of patients in both groups rated their knee function as normal or nearly normal on IKDC subjective evaluation. KT-1000 arthrometry showed that there was no difference between the two groups, with 0 to 3mm of laxity in 91% of the cases in the suture group versus 90% of cases in the EndoButton group. All patients achieved bony healing within 3 months. No significant complications were noted in the study.

CONCLUSIONS

Both the arthroscopic suture and EndoButton fixation methods for acute displaced posterior cruciate ligament avulsion fractures resulted in comparably good clinical outcomes, radiologic healing, and stable knees at mid-term follow-up.

LEVEL OF EVIDENCE

III; retrospective comparative study.

Suture versus screw fixation technique for tibial eminence fracture: A meta-analysis of laboratory studies

PURPOSE

The aim of this study was to compare the biomechanical properties between the suture fixation technique and the screw fixation technique for tibial eminence fracture (TEF).

METHODS

The current study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The PubMed, Embase, and the Cochrane were searched from inception to January 2019 comparing the suture and the screw fixation technique for TEF. The results of the eligible studies were analyzed in terms of stiffness, ultimate failure load, and displacement after the cyclic testing.

RESULTS

Six laboratory studies were included with a total of 114 knees: 57 knees were in the FiberWire suture group and 57 knees were in the single-screw group. The suture group had higher stiffness than the screw group, but there was no statistical difference between these two groups. Ultimate failure load in the suture group was statistically higher than that in the screw group. No statistically significant difference existed in displacement after the cyclic testing between the suture group and the screw group.

CONCLUSION

The FiberWire suture fixation may be biomechanically superior to a single screw fixation in TEF treatment in mature knees regarding ultimate failure load, while no significant difference was found between the two fixations in terms of stiffness and displacement after the cyclic testing.

Defined Daily Dose and Appropriateness of Clinical Application: The Coxibs and Traditional Nonsteroidal Anti-Inflammatory Drugs for Postoperative Orthopaedics Pain Control in a Private Hospital in Malaysia

Introduction: Drug utilization of analgesics in a private healthcare setting is useful to examine their prescribing patterns, especially the newer injectable cyclooxygenase (COX)-2 inhibitors (coxibs). Objectives: To evaluate the utilization of coxibs and traditional nonsteroidal anti-inflammatory drugs (tNSAIDs) indicated for postoperative orthopaedic pain control using defined daily dose (DDD) and ratio of use density to use rate (UD/UR). Method: A retrospective drug utilization review (DUR) of nonsteroidal anti-inflammatory drugs (NSAIDs) at an inpatient department of a private teaching hospital in Seremban, Malaysia was conducted. Patients’ demographic characteristics, medications prescribed, clinical lab results, visual analogue scale (VAS) pain scores and length of hospital stay were documented. Orthopaedic surgeries, namely arthroscopy, reconstructive, and fracture fixation, were included. Stratified random sampling was used to select patients. Data were collected through patients’ medical records. The DDD per 100 admissions and the indicator UD/UR were calculated with the World Health Organization’s DDD as a benchmark. The inclusion criteria were patients undergoing orthopaedic surgery prescribed with coxibs (celecoxib capsules, etoricoxib tablets, parecoxib injections) and tNSAIDs (dexketoprofen injections, diclofenac sodium tablets). Data were analysed descriptively. This research was approved by the academic institution and the hospital research ethics committee. Result: A total of 195 records of patients who received NSAIDs were randomly selected among 1169 cases. In term of the types of orthopaedic surgery, the ratio of included records for arthroscopy:fracture fixation:reconstructive surgery was 55.4:35.9:8.7. Most of the inpatients had low rates of common comorbidities such as cardiovascular disease as supported by their baseline parameters. The majority were not prescribed with other concomitant prescriptions that could cause drug interaction (74.9%), or gastroprotective agents (77.4%). Overall, DDDs per 100 admissions for all NSAIDs were less than 100, except for parecoxib injections (389.23). The UD/UR for all NSAIDs were less than 100, except for etoricoxib tablets (105.75) and parecoxib injections (108.00). Discussion: As per guidelines, the majority (96.9%) received other analgesics to ensure a multimodal approach was carried out to control pain. From the UD/UR results, the arthroscopy surgery was probably the most appropriate in terms of NSAID utilization. Conclusion: The prescribing pattern of NSAIDs except parecoxib was appropriate based on adverse effect and concurrent medication profile. The findings of this DUR provide insight for a low-risk patient population at a private specialized teaching hospital on the recommended use of NSAIDs for postoperative orthopaedic pain control.

Short-term clinical outcomes of arthroscopic fixation of displaced posterior cruciate ligament avulsion fractures with the use of an adjustable loop suspensory device

INTRODUCTION

To describe the clinical outcomes of arthroscopic fixation of displaced posterior cruciate ligament (PCL) avulsion fractures with/without associated tibia plateau fractures using an adjustable loop suspensory fixation device.

METHODS

Four male patients who have sustained PCL tibia avulsion fractures with/without associated tibia plateau fractures were operated on in a single centre using an arthroscopic adjustable loop suspensory device technique. After arthroscopic evaluation and reduction of the fracture using a probe and PCL drill guide, a proximal medial tibial mini incision was used to drill a bone tunnel through the fracture fragment. An adjustable loop suspensory device was relayed through the bone tunnel via a transtibial manner, and the button device was flipped onto the bony fragment for fixation. The associated tibial plateau fractures were then fixed if present. Knee function at the last follow-up was evaluated by International Knee Documentation Committee (IKDC), Knee Injury And Osteoarthritis Outcome Score (KOOS), Lysholm scores. Range of motion and knee stability were assessed, and fracture union was evaluated by plain radiographs.

RESULTS

All patients underwent the operation successfully with no major complications encountered. All were followed up for a minimum of 6 months. There was no instability reported by the patients or found during objective evaluation using posterior drawer test and reverse pivot shift test. All fractures achieved union. Mean post-operative Lysholm score was 91.5 (range 85-95), IKDC score was 85.1 (range 74.7-89.7) and KOOS was 89.3 (range 81.5-94.6). All patients returned to their pre-injury activities of daily living and work. Radiographic evaluation showed union at the fracture site in all four patients at the last follow-up.

CONCLUSION

This arthroscopic procedure is a viable minimally invasive technique that is appropriate in minimally displaced avulsion fractures of the PCL with associated tibia plateau fractures.

LEVEL OF EVIDENCE

Case Series, IV.

Arthroscopic fixation of ACL avulsion fracture in the saint pault hospital: A review of treatment outcomes: Cohort study

Background

The purpose of this research is to evaluate the results of arthroscopic suture fixation with fiber wires used as treatment for ACL avulsion fracture, and to determine how effective such a technique is when it comes to restoring of knee function.

Materials and methods

This prospective study involves 28 patients, who underwent arthroscopic fixation of displaced ACL avulsion fractures at Saint Paul Hospital (Hanoi) from January 2014 to March 2018.

Results

The first three weeks were not marked with any abnormalities associated with post-operative sutures and hematomas, infectious complications were not detected either. Post-operative displacement of fracture fragments did not take place among the patients involved in the study. At the 3-month follow-up, the average IKDC score was 90.7 (range: 76–100), and the average Lysholm score was 93.6 (range 82–100). The percentage of excellent scores was 42.9% (12 patients), good scores accounted for 50% (14 patients), while fair/poor scores accounted for 3.6% each (1 patient on each score). The percentage of excellent/good scores was 92.9% in total.

Conclusion

This study shows that ACL avulsion fracture can be treated effectively by arthroscopic suture fixation with fiber wires. In fact, this technique may restore knee function and stability.

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Evaluating the results of arthoscopic suture fixation with fiber wires used as treatment for ACL avulsion fracture.

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The study involves 28 patients.

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The ACL avulsion fracture can be treated effectively by arthoscopic suture fixation with fiber wires. It may restore knee function and stabiity.

Arthroscopic fixation of ACL avulsion fracture in the Saint Paul Hospital: a review of treatment outcomes

The purpose of this research is to evaluate the results of arthroscopic suture fixation with fiber wires used as treatment for ACL avulsion fracture, and to determine how effective such a technique is when it comes to restoring of knee function. This prospective study involves 28 patients, who underwent arthroscopic fixation of displaced ACL avulsion fractures at Saint Paul Hospital (Hanoi) from January 2014 to March 2018. The first 3 weeks were not marked with any abnormalities associated with postoperative sutures and hematomas; infectious complications were not detected either. Postoperative displacement of fracture fragments did not take place among the patients involved in the study. At the 3-month follow-up, the average IKDC score was 90.7 (range 76-100), and the average Lysholm score was 93.6 (range 82-100). The percentage of excellent scores was 42.9% (12 patients), good scores accounted for 50% (14 patients), while fair/poor scores accounted for 3.6% each (one patient on each score). The percentage of excellent/good scores was 92.9% in total. This study shows that ACL avulsion fracture can be treated effectively by arthroscopic suture fixation with fiber wires. In fact, this technique may restore knee function and stability.

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 Different Fixation Techniques for Posterior Cruciate Ligament Avulsion Fractures

PURPOSE

To analyze the ultimate failure load, yield load, stiffness, and cyclic elongation of 4 different fixation techniques for posterior cruciate ligament avulsion fractures under cyclic loading and load-to-failure conditions.

METHODS

In 40 porcine knees, a standardized bony avulsion of the posterior cruciate ligament was generated. The osseous avulsion was fixed by the following techniques through an open approach: (1) direct anterograde screw fixation (3.5 mm with washer), (2) retrograde screw fixation (3.5 mm with washer), (3) cortical suspension button fixation (with No. 2 braided suture), and (4) direct suture cerclage (with No. 2 braided suture). The constructs were cyclically loaded 500 times (10 to 100 N) to measure the maximum elongation. Subsequently, loading to failure was performed, and stiffness, yield load, and maximum load were measured. A 1-way analysis-of-variance test was performed with significance set at P < .05.

RESULTS

Button fixation resulted in lower elongation (1.25 ± 0.27 mm) than anterograde screw fixation (2.17 ± 0.74 mm, P = .0058) and the cerclage technique (2.02 ± 0.24 mm, P = .0290). The cerclage technique showed a lower yield load (493.55 ± 88.86 N) than anterograde screw fixation (720.39 ± 139.0 N, P = .0012) and retrograde screw fixation (668.58 ± 147.59 N, P = .0145); it also had lower stiffness and maximum load values (51.2 ± 6.11 N/mm and 631.22 ± 101.22 N, respectively) than the anterograde screw fixation technique (65.6 ± 12.74 N/mm, P = .041, for stiffness and 817.5 ± 145.9 N, P = .008, for maximum load). None of the other results were significantly different (P > .05).

CONCLUSIONS

The cortical suspension button and retrograde screw fixation techniques showed comparable structural properties to the direct screw fixation technique. The raw structural properties of suture cerclage still seem eligible enough to consider using this technique for fixation.

CLINICAL RELEVANCE

In this in vitro model, all techniques appear to constitute a biomechanically stable alternative to traditional anterograde screw fixation. In contrast to anterograde screw fixation, these techniques can be performed minimally invasively.

Arthroscopic 4-point suture fixation of anterior cruciate ligament tibial avulsion fractures

Tibial eminence avulsion fractures are rare injuries occurring mainly in adolescents and young adults. When necessary, regardless of patient age, anatomic reduction and stable internal fixation are mandatory for fracture healing and accurate restoration of normal knee biomechanics. Various arthroscopically assisted fixation methods with sutures, anchors, wires, or screws have been described but can be technically demanding, thus elongating operative times. The purpose of this article is to present a technical variation of arthroscopic suture fixation of anterior cruciate ligament avulsion fractures. Using thoracic drain needles over 2.4-mm anterior cruciate ligament tibial guidewires, we recommend the safe and easy creation of four 2.9-mm tibial tunnels at different angles and at specific points. This technique uses thoracic drain needles as suture passage cannulas and offers 4-point fixation stability, avoiding potential complications of bony bridge fracture and tunnel connection.

Neglected ununited tibial eminence fractures in the skeletally immature: arthroscopic management

PURPOSE

The purpose of this study was to prospectively evaluate outcomes of arthroscopic management of neglected ununited tibial eminence fractures in skeletally immature patients.

METHODS

The study was conducted and cases performed by two surgeons from two centres as a prospective case series of 13 patients with neglected ununited tibial eminence fractures: nine were girls and four were boys; ten were right knees and three were left. The average age at surgery was ten [standard deviation (SD) 2.6] years. Average follow-up was 10.8 (SD 6.8) months. Primary outcome measures used for evaluation were the Objective International Knee Documentation Committee Score (IKDC), subjective IKDC and modified Lysholm knee score. Secondary outcome measures were visual analogue scales (VAS) for pain and patient satisfaction.

RESULTS

Twelve patients had grade A objective IKDC score and one patient had grade B. Average subjective IKDC score was 80.5 (SD 16.7). Average modified Lysholm score was 91.2 (SD 8.9). Average VAS for operation satisfaction was 9.6 (SD 0.5) and for pain was 0.4 (SD 0.5). All patients showed radiological union and anatomical reduction at an average of 12.4 weeks postoperatively. At follow-up, all 13 patients showed complete range of motion (ROM). Eleven patients had negative Lachman, anterior drawer and pivot-shift tests, while two patients had grade 1 positive Lachman and negative anterior drawer and pivot-shift tests. No patient had complained of instability.

CONCLUSION

Neglected ununited tibial eminence fractures in skeletally immature patients achieve good functional outcome results when treated with arthroscopic reduction and internal fixation using sutures.