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

Purpose

To evaluate the initial stability of a suture anchor fixation and to compare this with a screw fixation and pull-out suture fixation for anterior cruciate ligament tibial avulsion fracture.

Methods

The initial fixation strength of 3 different fixation techniques, antegrade cannulated screw fixation, pull-out suture fixation with Ethibond and bioabsorbable knotless suture anchor fixation, was evaluated. Using 14 fresh cadavers (28 knees), the strength to failure, initial displacement and mode of failure were measured.

Results

The strength to failure of the suture anchor fixation was not significantly different from that of the screw fixation and was higher than that of the pull-out suture fixation. The initial displacement of the suture anchor fixation was lower than that of the screw fixation and the pull-out suture fixation. The majority of the suture anchor fixations and the screw fixations were failed by pull-out from the bone. Eight of the 56 suture anchor fixations failed by pull-out of the suture from the ligament proper. And, one of the 7 screw fixations failed due to fracture of the avulsed bony fragment. All of the pull-out suture fixations failed by suture material rupture.

Conclusions

These biomechanical results suggest that the initial fixation strength of suture anchor fixation was not less than that of screw fixation or pull-out suture fixation. And, the initial displacement of suture anchor fixation was lower than that of screw fixation or pull-out suture fixation. The suture anchor fixation appears to be a good alternative fixation technique for repair of anterior cruciate ligament tibial avulsion fracture.     

Is the transglenoid suture technique recommendable for recurrent shoulder dislocation? A minimum 5-year follow-up in 59 non-athletic shoulders

The aim of this retrospective study is to compare the clinical outcomes following arthroscopic Bankart repair employing the transglenoid technique versus suture anchors in non-athletic shoulders of patients 30 years or older at the time of surgery. Fifty-nine consecutive patients who were available for a minimum of 5 years follow-up after arthroscopic Bankart repair were included. The transglenoid technique was employed in 27 patients whose age and follow-up period were 37 years (range 30–58) and 82 (range 61–109) months. Suture anchor was used in 32 patients whose age and follow-up period were 38 years (range 30–62) and 72 months (range 65–89). The Rowe scores of the transglenoid and suture anchor groups were 90 (range 35–100) and 90 (range 35–100), respectively, and there was no statistically significant difference between the two groups (p > 0.05). The Constant score of both groups was 92 (range 64–100) and 95 (range 62–100) without a significant difference (p > 0.05). Moreover, there were no significant differences between the recurrence rates (7%-transglenoid, 6%-suture anchor) (p > 0.05) and positive apprehension signs (7%-transglenoid, 3%-suture anchor) (p > 0.05). In non-athletes over 30-years-old, the results of the transglenoid technique in arthroscopic Bankart repair were comparable to those of the suture anchor. We suggest that the transglenoid technique is a viable alternative for older, non-athletic shoulder if the suture anchors are not available.     

Arthroscopic three-point double-row repair for acute bony Bankart lesions

After mobilizing anteroinferior osseous Bankart lesion from the glenoid neck, a suture anchor loaded with differently colored non-absorbable braided sutures is placed on the medial edge in the glenoid neck along the rim fracture through the anterior-inferior trans-subscapularis tendon portal. Two same-colored suture limbs on the anchor are then pulled through the labrum using PDS suture shuttling simultaneously. These steps are repeated for the others suture limbs. The two same-color suture limbs located inferiorly are retrieved using the trans-subscapularis tendon portal. Both suture strands are threaded through the eyelet of a PushLock anchor on the distal end of the driver. The anchor is advanced into the pilot hole completely. These steps are repeated for a second anchor at the upper edge of the fracture in the glenoid rim using the anterior portal. This technique confers effective, firm fixation of the bony Bankart lesion by three-point fixation without the suture material crossing the glenoid cavity.     

A new “double-pulley” dual-row technique for arthroscopic fixation of bony Bankart lesion

The double-row technique is a new concept for arthroscopic treatment of bony Bankart lesion in shoulder instability. It presents a new and reproducible technique for arthroscopic fixation of bony Bankart fragments with suture anchors. This technique creates double-mattress sutures which compress the fragment against its bone bed and restores better bony anatomy of the anterior glenoid rim with stable and non-tilting fixation that may improve healing.     

Open Bankart repair versus arthroscopic repair with transglenoid sutures or bioabsorbable tacks for Recurrent Anterior instability of the shoulder: a meta-analysis

BACKGROUND: In published comparative studies, it remains unknown if arthroscopic techniques for performing Bankart repair for anterior shoulder instability equal the success of open repair. HYPOTHESIS: The current literature supports a lower rate of recurrent instability after open Bankart repair compared to arthroscopic repair with bioabsorbable tacks or transglenoid sutures. STUDY DESIGN: Meta-analysis. METHODS: A Medline search identified all randomized controlled trials or cohort studies that directly compared open repair to arthroscopic techniques of Bankart repair for traumatic, unilateral, recurrent anterior instability. Data collected from each study included patient demographics, surgical technique, rehabilitation, outcome, and complications. RESULTS: Six studies met all inclusion criteria. There were 172 patients in the arthroscopic group (90 patients with transglenoid sutures, 77 patients with arthroscopic tacks, and 5 patients with suture anchors) and 156 patients in the open group. The groups were similar in demographic characteristics. When comparing the arthroscopic to the open group, there was a significantly higher rate of recurrent dislocation (12.6% vs 3.4%; P = .01) and total recurrence (recurrent dislocation or subluxation) (20.3% vs 10.3%; P = .01). In addition, there was a higher proportion of patients with an excellent or good postoperative Rowe score in the open group (88%) than in the arthroscopic group (71%) (P = .01). CONCLUSIONS: Arthroscopic Bankart repair using transglenoid sutures or bioabsorbable tacks results in a higher rate of recurrence of instability compared to open techniques. Studies comparing open repair to newer arthroscopic techniques using suture anchor fixation and capsular plication are necessary.     

Stress distribution in the supraspinatus tendon after tendon repair: suture anchors versus transosseous suture fixation

BACKGROUND: The stress concentration at the site of supraspinatus tendon repair, either by suture anchor fixation or by transosseous suture fixation, has not been fully clarified. HYPOTHESIS: Suture anchor fixation showed higher stress concentrations in the tendon than did transosseous suture fixation. STUDY DESIGN: Controlled laboratory study. METHODS: Three finite element models were developed based on a previously published model of normal supraspinatus tendon (0 degrees abduction). Single-row fixation, double-row fixation, and transosseous suture fixation were simulated. A tensile force was applied to the proximal end of the supraspinatus tendon to simulate its contraction force. RESULTS: In the single-row model, the stress appeared from the site of the anchor and extended into the proximal tendon. The highest stress concentration was observed on the bursal surface of the tendon. The double-row model showed a similar pattern to the single-row model except that the stress concentration was observed only around the medial anchor. In the transosseous model, the stress appeared from the attachment site to a bony trough, which extended proximally into the tendon substance. No significant stress concentration was observed inside the tendon. CONCLUSION: Both single-row and double-row fixations showed higher stress concentration inside the tendon than did transosseous suture fixation. CLINICAL RELEVANCE: A high stress concentration might be a cause of the rerupture often observed after arthroscopic cuff repair using suture anchors.     

Revision using modified transglenoid reconstruction in recurred glenohumeral instability combined with anchor-induced arthropathy

A 25-year-old man presented with a history of pain and crepitus in the right shoulder; he had been previously treated with arthroscopic anterior stabilization using four metallic suture anchors for recurrent traumatic anterior instability 1 year earlier. In this report, we present a patient with recurrent glenohumeral instability combined with anchor-induced arthropathy who was managed with modified arthroscopic transglenoid reconstruction following arthroscopic suture anchor retrieval.     

Suture anchor and percutaneous intra-articular transtendon biceps tenodesis

Several arthroscopic biceps tenodesis techniques have been described for surgical management of tendonitis and/or partial thickness tears of the long head of the biceps brachii tendon resulting in recalcitrant anterior shoulder pain. This chapter describes an arthroscopic tenodesis using percutaneous intra-articular transtendon technique with suture anchor fixation. The percutaneous technique allows excellent access to the biceps tendon, and the addition of a suture anchor provides superior fixation to isolated soft tissue fixation.     

Arthroscopic hybrid double-row rotator cuff repair

A Beath pin is drilled on the greater tuberosity under arthroscopy using an anterior cruciate ligament guide. The suture anchor is inserted in the lateral aspect of the footprint. Sutures are then passed through the margins of the rotator cuff tear and tied with sliding knot. One strand of tied suture anchor is passed into the bony trough. One passed strand and the other strand are then tied with a non-sliding knot on the greater tuberosity. The strength of cuff fixation does not only rely on the quality of the bone, it restores the footprint contact area of rotator cuff, and reduces the use of suture anchors to the minimum in this method.     

Tendon-bone interface motion in transosseous suture and suture anchor rotator cuff repair techniques

BACKGROUND: Although many studies involving rotator cuff repair fixation have focused on ultimate fixation strength and ability to restore the tendon's native footprint, no studies have characterized the stability of the repair with regard to motion between the tendon and repair site footprint. HYPOTHESIS: Suture anchor fixation for rotator cuff repair has greater interface motion between tendon and bone than does transosseous suture fixation. STUDY DESIGN: Controlled laboratory study. METHODS: Twelve fresh-frozen human cadaveric shoulders were tested in a custom device to position the shoulder in internal and external rotations with simulated supraspinatus muscle loading. Tendon motion relative to the insertional footprint on the greater tuberosity was determined optically using a digital camera rigidly connected to the humerus, with the humerus positioned at 60 degrees of internal rotation and 60 degrees of external rotation. Testing was performed for the intact tendon, a complete supraspinatus tear, a suture anchor repair, and a transosseous tunnel repair. RESULTS: Difference in tendon-bone interface motion when compared with the intact tendon was 7.14 +/- 3.72 mm for the torn rotator cuff condition, 2.35 +/- 1.26 mm for the suture anchor repair, and 0.02 +/- 1.18 mm for the transosseous suture repair. The transosseous suture repair demonstrated significantly less motion when compared with the torn rotator cuff and suture anchor repair conditions (P < .05). CONCLUSION: Transosseous suture repair compared with suture anchor repair demonstrated superior tendon fixation with reduced motion at the tendon-to-tuberosity interface. CLINICAL RELEVANCE: Development of new fixation techniques for arthroscopic and open rotator cuff repairs should attempt to minimize interface motion of the tendon relative to the tuberosity.     

Biomechanical evaluation of a new technique for rotator cuff repair

BACKGROUND: In recent studies, investigators have used a cyclic loading model to investigate the efficacy of rotator cuff fixation modalities. HYPOTHESIS: A bioabsorbable poly-D-lactic acid screw and toothed washer implant will provide more stable fixation of rotator cuff repairs than standard suture anchor techniques. STUDY DESIGN: Controlled laboratory study. METHODS: Forty bovine shoulders (ages 3 to 6 months) had 1 x 2 cm defects created in the infraspinatus tendon. There were five repair groups (eight specimens per group) consisting of either two screw and washer implants or two suture anchors. Four suture techniques were tested: single-loaded anchors with simple sutures, double-loaded anchors with simple sutures, single-loaded anchors with horizontal mattress sutures, or single-loaded anchors with modified Mason-Allen sutures. Repairs were loaded at 5-second cycles from 10 to 180 N with use of a hydraulic testing machine. The number of cycles to gap formation of 5 and 10 mm was recorded. RESULTS: Gap formation of 5 and 10 mm occurred significantly later for the screw repair group than for any of the suture anchor groups. There was no significant difference between suture groups. CONCLUSIONS: The bioabsorbable screw and washer provided more stable fixation than suture anchor techniques under isometric cyclic loading conditions. Clinical Relevance: This is a time-zero study of implant performance. The results indicate that the implant may decrease clinical failures in the early postoperative period under standard rehabilitation protocols.     

A new technique: in vitro suture anchor fixation has superior yield strength to bone tunnel fixation for distal biceps tendon repair

BACKGROUND: Suture anchor and bone tunnel fixations are used for distal biceps tendon repairs and have not been compared. HYPOTHESIS: Suture anchor fixation is equal or superior to bone tunnel fixation. STUDY DESIGN: Randomized controlled in vitro study. METHODS: A new fixation technique was compared to traditional bone tunnel fixation of distal biceps tendon ruptures between randomly selected sides of nine matched-pair, fresh-frozen elbow specimens from cadaveric donors (mean age = 74.7 years). Bone densities were determined. The distal biceps tendon was attached to the actuator of a servohydraulic load frame and loaded to tensile failure at a constant rate of 4 mm/sec. Bone density, sex, age, side, tuberosity area, repair, failure type, repair stiffness, and yield strength were compared. RESULTS: Superior yield strength of suture anchor fixation (263 N) compared to bone tunnel fixation (203 N) (P = 0.0233) were demonstrated. When suture anchor fixation failure (1 of 9) occurred, the matched pair also failed. CONCLUSION: Suture anchor fixation offers an equal if not superior alternative to bone tunnel fixation for repair of the distal biceps tendon in the specimens tested. Clinical Relevance: Suture anchor fixation may be used for distal biceps tendon repairs.     

Open reconstruction of anterior glenoid rim fractures

The present study evaluates the clinical and radiological results of patients with anterior glenoid rim fractures treated with two different open surgical techniques depending on the size of the bony fragment. In patients with displaced glenoid rim fractures involving less than 25% of the glenoid surface (Type I, II and IIIA fractures) suture anchor repair was performed. Patients with a bony defect involving more than 25% of the glenoid surface (Type IIIB fractures) underwent open reduction and internal fixation using cannulated screws. After a mean follow-up of 22 months, 15 patients (mean age 42.2 years) treated with suture anchor repair achieved an average Constant Score of 85.5 points (range 67.1–100) and an average Rowe Score of 94 points (range 70–100). In six patients the bony fragment was located in an unimproved medial position compared to the preoperative X-ray. In another six patients the fragment was consolidated medially to the level of the glenoid rim, and in three cases an anatomic situation was found. Patients treated with cannulated screws (ten cases, mean age 46.6 years) had a mean follow-up of 30 months and achieved a mean Constant Score of 81.9 points (range 61.7–96.1) and a mean Rowe Score of 90 points (range 70–100). Radiologically, the bony fragment was consolidated in an anatomic position in nine out of ten cases. Three patients suffered from screw impingement and one patient had screw loosening. No recurrent subluxations or dislocations were observed in either group. Three patients in group one and one patient in group two had glenohumeral osteoarthritic changes. In cases of small glenoid-rim fractures (Type I, II and IIIA fractures), suture anchor repair resulted in an excellent clinical outcome; however, the radiological results of chronic Type I fractures revealed in many cases a non-anatomical glenoidal reconstruction. For Type IIIB fractures with significant loss of glenoid concavity, open reduction and internal fixation with cannulated screws gave good clinical and radiological results; however the early complication rate was higher.     

Modification of the Bankart reconstruction with a suture anchor. Report of a new technique

We assessed the effectiveness of a new suture anchor that has been designed to anchor sutures into a blind, straight hole drilled in bone. The strength of fixation in glenoid bone is 67 N for the No. 0 anchor and suture, and 82 N for the No. 2 device with suture. During 1988 and 1989, 32 patients underwent a modified Bankart reconstruction for recurrent anterior glenohumeral instability at two centers as part of a prospective study of this modified technique. There were no complications as a result of the technique. The four surgeons involved agreed that the suture anchor simplified the procedure. Seventeen patients have been reviewed, with more than 1 year followup. Ninety-four percent had good to excellent results according to the Bankart rating scale. There was one recurrent dislocation in a football player.     

Distal biceps brachii tendon repair: Suture anchor technique

Rupture of the biceps brachii tendon has been associated with significant loss of flexion and supination strength.Several techniques have been described with reports of clinical success. The single incision suture anchor repair technique produces clinical results comparable with other methods of fixation with low complication rates. The procedure can be performed through a limited 3-cm transverse incision with minimal dissection. The surgical technique and postoperative rehabilitation are described.     

Fatigue testing of suture anchors

In a porcine tibia model, we subjected widely used anchor-suture combinations to a fatigue-testing protocol. The Ethibond No. 2 suture was the weakest part of the anchor-suture combinations when they were loaded to failure by a single pull. Under cyclic-loading conditions, fixation strength was decreased compared with single-pull tests. The suture/anchor interface was identified as the weakest link in the Mitek GII/No. 2 combination and in the Zimmer Statak 3.5/No. 2 combination. In most cases the suture was worn through at the eyelet. Threading the GII anchor with a No. 5 suture and use of larger anchors in combination with No. 2 sutures increased the fatigue strength. Suture breakage at the knot was the predominant failure mode for biodegradable anchors inserted into cortical bone. The highest fatigue strength was seen for the Super Anchor/No. 5 combination when the anchor was inserted in cortical bone. Fatigue testing is crucial for evaluation of suture anchors and should be performed along with single-pull testing. The mechanical performance of a suture anchor threaded with a defined suture depends on several key factors: the pullout strength of the anchor, the tensile strength of the suture, and the interaction of anchor and suture at the eyelet (suture/anchor interface).     

锚钉治疗髌下极撕脱骨折的疗效观察

目的探讨应用锚钉髌骨环形固定术治疗髌骨下极撕脱性骨折的临床疗效。方法回顾性分析2007年1月～2010年12月,采用美国施乐辉公司生产的5.5 mm钛质双固定钉（锚钉）,行髌骨环形固定术治疗髌骨下极撕脱骨折58例,术后早期行膝关节功能锻炼。结果随访6～32个月,平均18个月,均未发现骨折分离移位。采用Lysholm评分标准评价疗效,优48例,良8例,可2例,优良率为96.55%。结论采用锚钉行髌骨环形固定术治疗髌骨下极撕脱性骨折,能有效复位固定骨折,膝关节功能恢复优良率96.55%。此方法安全简便易掌握,是治疗髌骨下极撕脱性骨折的有效方法,值得推广。     

Arthroscopic fixation of anterior cruciate ligament tibial avulsion fractures using bioabsorbable suture anchors

This article describes a new technique for the arthroscopic reduction and fixation of anterior cruciate ligament (ACL) tibial avulsion fractures using bioabsorbable suture anchors. This described technique requires the use of anterolateral, anteromedial, medial mid-patellar, and lateral mid-patellar portals. A suture hook loaded with No. 2 polydioxanone (PDS) was used to pierce the ACL through the anteromedial or anterolateral portal, and bioabsorbable suture anchors were inserted through the medial and lateral mid-patellar portals. The five patients treated using this technique were evaluated at 1 year postoperatively. All patients showed bony union without anterior laxity or flexion contracture. The described technique provides firm fixation of fracture fragment and can be used in both skeletally immature and mature patients.     

Biomechanical stability of different suture fixation techniques for tibial eminence fractures

Purpose

Displaced tibial eminence fractures require surgical fixation in order to obtain a stable knee joint. Suture fixation with FiberWire^® seems to be the most favorable therapeutic option. Biomechanical studies show failure of this technique most commonly due to a suture cutout with subsequent fracture of the tibial eminence fragment. The goal of this study is to compare the biomechanical properties of three different techniques of suture fixation using FiberWire^®.

Methods

Bone mineral density was evaluated in 18 human knee specimens by pqCT, and three similar groups were formed. A standardized anterior tibial eminence fracture was created, and suture fixation was performed using one of three different techniques in 6 specimens each. Cyclic and destructive testing was conducted.

Results

Significant differences between the three techniques could be shown neither in the cycles needed to achieve a steady state nor in a failure load or initial stiffness. Almost all specimens failed by suture cutout.

Conclusion

The presented modification of the existing technique for suture fixation of tibial eminence fractures did not lead to an increased initial stability nor did it lower the rate of suture cutout. All tested suture techniques showed comparable initial stiffness and failure load.