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Purpose: To evaluate the effects of different stitching methods and suture diameters on the graft fixation of soft tissue human quadriceps tendon grafts for anterior cruciate ligament (ACL) reconstruction., Methods: The Krackow locking stitch (K), whipstitch (W), and baseball stitch (B) were combined with either a 2× no. 2 (#2) or a 1× no. 5 (#5) braided composite suture for graft fixation of 36 human quadriceps tendons in 6 groups. Biomechanical testing was performed using a cyclic protocol with loads between 0 and 100 N. The maximum load until failure, cyclic elongation, and failure mode were recorded., Results: The highest mean maximum load to failure was observed in the 2 Krackow stitch groups. The K#2 group had significantly higher load to failure values compared with those of the W#2 and B#2 groups (K#2, 553 ± 82 N vs W#2, 392 ± 107 N, P = .0349; K#2 vs B#2 366 ± 118 N, P = .0129). The mean cyclic elongation was lowest in the Krackow groups (K#2, 10.59 ± 2.63 mm; K#5, 13.66 ± 2.3 mm). The regular failure mode was the rupture of the suture for the Krackow stitch (8 of 12) and suture pullout for the whipstitch (11 of 12) and baseball stitch groups (12 of 12)., Conclusions: The double Krackow stitch with no. 2 braided composite suture exhibits a high maximum load to failure combined with a low amount of elongation in a biomechanical study for human quadriceps tendon soft tissue graft fixation. Unlike the whipstitch and the baseball stitch, it can solidly prevent suture pullout., Clinical Relevance: A safe soft tissue graft fixation technique is especially important for quadriceps tendon grafts with their laminar anatomical structure and physiologically varying diameter. Unlike other grafts for ACL replacement, it fully relies on the soft tissue suture fixation to resist the pullout force., (Copyright © 2019 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To determine the inter-rater reliability (IRR) of a procedure-specific checklist scored in a binary fashion for the evaluation of surgical skill and whether it meets a minimum level of agreement (≥0.8 between 2 raters) required for high-stakes assessment., Methods: In a prospective randomized and blinded fashion, and after detailed assessment training, 10 Arthroscopy Association of North America Master/Associate Master faculty arthroscopic surgeons (in 5 pairs) with an average of 21 years of surgical experience assessed the video-recorded 3-anchor arthroscopic Bankart repair performance of 44 postgraduate year 4 or 5 residents from 21 Accreditation Council for Graduate Medical Education orthopaedic residency training programs from across the United States., Results: No paired scores of resident surgeon performance evaluated by the 5 teams of faculty assessors dropped below the 0.8 IRR level (mean = 0.93; range 0.84-0.99; standard deviation = 0.035). A comparison between the 5 assessor groups with 1 factor analysis of variance showed that there was no significant difference between the groups (P = .205). Pearson's product-moment correlation coefficient revealed a strong and statistically significant negative correlation, that is, -0.856 (P < .000), indicating that as intra-operative error rate scores increased, the IRR decreased., Conclusions: Arthroscopy Association of North America shoulder faculty raters from across the United States showed high levels of IRR in the assessment of an arthroscopic 3-anchor Bankart repair procedure. All paired assessments were above the 0.8 level and the mean IRR of all resident assessments was 0.93, indicating that they could be used for high-stakes decisions., Clinical Relevance: With the move toward outcomes-based performance evaluation for graduate medical education, high-stakes assessments of surgical skill will require robust, reliable measurement tools that are able to withstand challenge. Surgical checklists employing metrics scored in a binary fashion meet the need and can show a high (>80%) IRR., (Copyright © 2018 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Biomechanical studies are commonly used to validate new or modified rotator cuff repair techniques. Additional knots, more tendon suture passes, and obligatory suture management requirements are often the "cost" for improved biomechanical results. This cost can amount to increased technical difficulty and surgical times. However, technical ease or difficulty as a measurable variable has not been quantified. A basic measure for technical ease would allow surgeons the ability to objectively assess and compare rotator cuff repair practicality and potentially help in the design of future studies to standardize repair techniques alongside biomechanical measures. A proposed rotator cuff repair "technical efficiency ratio" is defined as follows: (No. of knots + No. of tendon suture passes + No. of suture limbs)/No. of pilot holes created. This can give a measure of "work" or utility achieved per fixation point created for a particular type of repair (e.g., single or double row), with a smaller number representing relatively more efficiency per anchor or fixation point used. If repairs validated in the laboratory are too cumbersome to perform in vivo from a practical standpoint, technical ease should be a prerequisite measure, and the success of a repair technique should not necessarily be based on biomechanics alone., (Copyright © 2013 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: The purpose of this study was to compare the time-zero biomechanical strength and the surface area of repair between a single-row modified Mason-Allen rotator cuff repair and a double-row arthroscopic repair., Methods: Six matched pairs of sheep infraspinatus tendons were repaired by both techniques. Pressure-sensitive film was used to measure the surface area of repair for each configuration. Specimens were biomechanically tested with cyclic loading from 20 N to 30 N for 20 cycles and were loaded to failure at a rate of 1 mm/s. Failure was defined at 5 mm of gap formation., Results: Double-row suture anchor fixation restored a mean surface area of 258.23 +/- 69.7 mm(2) versus 148.08 +/- 75.5 mm(2) for single-row fixation, a 74% increase (P = .025). Both repairs had statistically similar time-zero biomechanics. There was no statistical difference in peak-to-peak displacement or elongation during cyclic loading. Single-row fixation showed a higher mean load to failure (110.26 +/- 26.4 N) than double-row fixation (108.93 +/- 21.8 N). This was not statistically significant (P = .932). All specimens failed at the suture-tendon interface., Conclusions: Double-row suture anchor fixation restores a greater percentage of the anatomic footprint when compared with a single-row Mason-Allen technique. The time-zero biomechanical strength was not significantly different between the 2 study groups. This study suggests that the 2 factors are independent of each other., Clinical Relevance: Surface area and biomechanical strength of fixation are 2 independent factors in the outcome of rotator cuff repair. Maximizing both factors may increase the likelihood of complete tendon-bone healing and ultimately improve clinical outcomes. For smaller tears, a single-row modified Mason-Allen suture technique may provide sufficient strength, but for large amenable tears, a double row can provide both strength and increased surface area for healing.

Purpose: This study evaluated the strength and suture-tendon interface security of different suture configurations from triple-suture-loaded anchors., Methods: A juvenile bovine infraspinatus tendon was detached and repaired by use of 4 different suture combinations from 2 suture anchors: 3 simple sutures in each anchor (ThreeVo anchor; Linvatec, Largo, FL); 2 peripheral simple stitches and 1 central horizontal mattress suture passed deeper into the tendon, creating a larger footprint (bigfoot-print anchor); 2 peripheral simple stitches with 1 central horizontal mattress stitch passed through the same holes as the simple sutures (stitch-of-Burns); and 2 simple stitches (TwoVo anchor; Linvatec). The constructs were cyclically loaded between 10 N and 180 N for 3,500 cycles and then destructively tested. The number of cycles required to create a 5-mm gap and a 10-mm gap and the ultimate load to failure and failure mode were recorded., Results: The ThreeVo anchor was strongest and most resistant to cyclic loading (P < .01). The TwoVo anchor was least resistant to cyclic loading. The stitch-of-Burns anchor was more resistant to cyclic loading than both the bigfoot-print anchor and the TwoVo anchor (P < .03). The ThreeVo, stitch-of-Burns, and TwoVo anchors were stronger than the bigfoot-print anchor (P < .05)., Conclusions: Three simple sutures in an anchor hold better than two simple sutures. Three simple sutures provide superior suture-tendon security than combinations of one mattress and two simple stitches subjected to cyclic loading. A central mattress stitch placed more medially than two peripheral simple stitches (bigfoot-print anchor) configured to enlarge the tendon-suture footprint was not as resistant to cyclic loading or destructive testing as three simple stitches (ThreeVo anchor)., Clinical Relevance: Placing a central mattress stitch more medially than 2 peripheral simple stitches to enlarge the tendon-suture footprint was not as resistant to cyclic loading or destructive testing as 3 simple stitches.

Purpose: The purpose of this study was to compare the initial mechanical strength of 3 rotator cuff repair techniques., Methods: A total of 30 fresh-frozen cadaveric shoulders were prepared, and full-thickness supraspinatus tears were created. Specimens were randomized and placed into 3 groups: (1) transosseous suture technique (group I: TOS, n = 10, 6F/4M), (2) single-row suture anchor fixation (group II: SRSA, n = 10, 6F/4M), and (3) double-row suture anchor fixation (group III: DRSA, n = 10, 6F/4M). Each specimen underwent cyclic load testing from 5 N to 180 N at a rate of 33 mm/sec. The test was stopped when complete failure (repair site gap of 10 mm) or a total of 5,000 cycles was attained., Results: Group I (TOS) failed at an average of 75.3 +/- 22.49 cycles, and group II (SRSA) at an average of 798.3 +/- 73.28 cycles; group III (DRSA) had no failures because all samples were stopped when 5,000 cycles had been completed. Fixation strength of the DRSA technique proved to be significantly greater than that of SRSA (P < .001), and both suture anchor groups were significantly stronger than the TOS group (P < .001)., Conclusions: Suture anchor repairs were significantly stronger than transosseous repairs. Furthermore, double-row suture anchor fixation was significantly stronger than was single-row repair. Therefore, double-row fixation may be superior to other techniques in that it provides a substantially stronger repair that could lead to improved biologic healing., Clinical Relevance: A high incidence of incomplete healing occurs in rotator cuff repair. Use of double-row fixation may help the clinician to address some deficiencies in current methods by increasing the strength of the repair, potentially leading to improved healing rates.

Purpose: To compare the loop and knot security of arthroscopic square knots with other arthroscopic and open knots with the use of 2 commonly used suture types., Methods: Five knot configurations were tested 12 times each. The arthroscopic square knot was compared with the open square knot, arthroscopic and open half hitches with alternating posts, and the Duncan loop. Load-to-failure testing was performed at a rate of 1.25 mm/sec, and cyclic testing was performed between 7 N and 30 N at a rate of 1 N/sec for 50 cycles. Two suture types were tested: No. 2 Ethibond suture and No. 2 FiberWire., Results: Among the No. 2 Ethibond sutures, the arthroscopic Duncan loop had the highest load-to-failure at 165 N. The remaining knot types failed at between 142 N and 148 N. The load at 3 mm of lengthening was between 100 N and 120 N for all knots. The No. 2 FiberWire failed at higher loads than the No. 2 Ethibond suture for all knot types except the Duncan loop. The arthroscopic half hitches, arthroscopic square knots, and open half hitches all failed at between 220 N and 264 N. The open square knot failed at 188 N, and the Duncan loop failed at 147 N. The load at 3 mm of lengthening was between 130 N and 165 N for all knots except the Duncan loop, which failed at 95 N. With cyclic testing, arthroscopic square knots performed better than all knot types, but the differences were clinically insignificant., Conclusions: Arthroscopic square knots have the same or greater strength when compared with other arthroscopic or open knots tied with the same suture type, and they perform as well or better in the face of cyclic loads. Good knot security can be attained with all of the knots tested, regardless of suture type. Equivalent knots tied with No. 2 FiberWire fail at higher loads, except for those tied with the Duncan loop., Clinical Relevance: Arthroscopic square knots can be used in the clinical setting with no compromise in function when compared with open square knots.

Purpose: To compare the performance of a standard suture material with that of a new material across several arthroscopic knot configurations., Methods: Three knots were evaluated (Duncan loop, Weston, and San Diego knots) with the use of 2 suture materials (No. 2 Ethibond [Ethicon, Somerville, NJ] and No. 2 Force Fiber [Stryker Endoscopy, San Jose, CA]). Ten samples were tested for each knot and suture configuration. Samples were pretensioned to 10 N and were mechanically loaded from 10 to 45 N for 1,000 cycles. The number of cycles to 3 mm of loop elongation was recorded as "early" slippage. Intact knots with no evidence of early slippage were then subjected to a load-to-failure test so that the ultimate failure strength of the knot/material could be determined., Results: Force Fiber knots required a statistically greater number of cycles to reach 3 mm of slippage compared with Ethibond knots (P < .0001). A single Force Fiber knot experienced 3 mm of displacement during cyclic loading; all others survived to 1,000 cycles. One third of all Ethibond knots were displaced to 3 mm during cyclic loading. For Ethibond sutures, no significant differences in ultimate failure strength were observed between knots (average, 143 N across knot types). For Force Fiber sutures, the San Diego knot (279 +/- 41 N) was statistically similar in ultimate failure strength to the Weston knot (254 +/- 41 N), but it was significantly stronger than the Duncan knot (224 +/- 70 N) (P < .03)., Conclusions: The higher failure loads associated with Force Fiber may allow the surgeon to increase suture tension during knot tying, thereby creating a tighter knot. Loop elongation with Force Fiber occurred at loads that were greater than the typical breakage load for No. 2 Ethibond. Force Fiber is a new material that may be useful for various arthroscopic procedures., Clinical Relevance: Force Fiber provided increased biomechanical stability compared with Ethibond regardless of knot type. The cost benefit of using very strong yet very stiff sutures must be clinically evaluated.

Purpose: To determine the role of arthroscopic knot-tying instrumentation in achieving knot security., Type of Study: Biomechanical study., Methods: The security achieved by 3 different commercially available knot-tying instruments using No. 2 braided suture and a standardized knot configuration was compared. Instrumentation included (1) a single-hole knot pusher, (2) a cannulated double-diameter knot pusher, and (3) a mechanical end-splitting knot tightener. Hand-tied knots served as controls. Testing included both cyclic loading and load to failure parameters using the Bionix 858 (MTS Inc, Eden Prairie, MN) and Instron Mini 44 (Instron, Canton, MA) materials testing systems, respectively. An experienced arthroscopic shoulder surgeon and a less experienced junior-level orthopaedic resident surgeon performed tying., Results: Knot displacement after cyclic loading was smallest for the mechanical end-splitting knot tightener (average, 0.054 mm) and did not differ statistically from hand-tied knots (average, 0.058 mm). Knots tied with this device also withstood the greatest load to failure (average, 126.0 N) and were statistically similar to hand-tied knots (average, 134.1 N). The single-hole pusher had an average cyclic loading displacement of 0.095 mm and failed at 108.6 N. The cannulated double-diameter pushers had an average cyclic loading displacement of 0.106 mm and failed at 93.1 N. Both were statistically less secure than hand-tied knots or those tied with the end-splitting tightener. Investigator experience did not affect knot security with those tied by the mechanical end-splitting tightener or hand-tied knots., Conclusions: The end-splitting tightener provided the most secure arthroscopic knots that were statistically as secure as those tied by hand for both investigators. The knot-tying instrument used in arthroscopic shoulder surgery may be an important consideration with potential clinical implications based on knot security., Clinical Relevance: The specific knot tying instrument that is selected for use in arthroscopic shoulder surgery may play an important role in the degree of ultimate knot security achieved in suture repair.

The primary stability of four common meniscus suture techniques was tested on human cadaver menisci. The test series was carried out under standard conditions (25 degrees C, 100% air humidity) using the Instron 1122 Tensometer. The tearing stress of different sutures was reproducible in different specimens dependent only on the suture technique. Knot-end techniques gave inferior results (tearing stress, 24 +/- 9 N) compared with arthroscopic techniques using a loop placed on the meniscus surface (tearing stress, 89 +/- 4 N). When an open meniscus repair is performed, a vertical stitching technique (tearing stress, 105 +/- 4 N) should be the preferred method. Horizontal sutures are weaker (tearing stress, 44 +/- 18 N).