All-Suture Anchors: Biomechanical Analysis of Pullout Strength, Displacement, and Failure Mode.

PURPOSE: To evaluate the biomechanical and design characteristics of all-suture anchors. METHODS: All-suture anchors were tested in fresh porcine cortical bone and biphasic polyurethane foam blocks by cyclic loading (10-100 N for 200 cycles), followed by destructive testing parallel to the insertion axis at 12.5 mm/s. Endpoints included ultimate failure load, displacement at 100 and 200 cycles, stiffness, and failure mode. Anchors tested included JuggerKnot (1.4, 1.5, and 2.8), Iconix (1, 2, and 3), Y-knot (1.3, 1.8, and 2.8), Q-Fix (1.8 and 2.8), and Draw Tight (1.8 and 3.2). RESULTS: The mean ultimate failure strength of the triple-loaded anchors (564 ± 42 N) was significantly greater than the mean ultimate failure strength of the double-loaded anchors (465 ± 33 N) (P = .017), and the double-loaded anchors were stronger than the single-loaded anchors (256 ± 35 N) (P < .0001). No difference was found between the results in porcine bone and biphasic polyurethane foam. None of these anchors demonstrated 5 mm or 10 mm of displacement during cyclic loading. The Y-Knot demonstrated greater displacement than the JuggerKnot and Q-Fix (P = .025) but not the Iconix and Draw Tight (P > .05). The most common failure mode varied and was suture breaking for the Q-Fix (97%), JuggerKnot (81%), and Iconix anchors (58%), anchor pullout with the Draw Tight (76%), whereas the Y-Knot was 50% suture breaking and 50% anchor pullout. CONCLUSIONS: The ultimate failure load of an all-suture anchor is correlated directly with its number of sutures. With cyclic loading, the Y-Knot demonstrated greater displacement than the JuggerKnot and Q-Fix but not the Iconix and Draw Tight. JuggerKnot (81%) and Q-Fix (97%) anchors failed by suture breaking, whereas the Draw Tight anchor failed by anchor pullout (76%). CLINICAL RELEVANCE: All-suture anchors vary in strength and performance, and these factors may influence clinical success. Biphasic polyurethane foam is a validated model for suture anchor testing.

Using Puppets to Teach Schoolchildren to Detect Stroke and Call 911.

To overcome barriers to improved outcomes, we undertook an intervention to teach schoolchildren how to detect a stroke and call emergency medical services (EMS). We obtained permission from parents and guardians to use an 8-min puppet show to instruct the fourth, fifth, and sixth graders about stroke detection, symptomatology, and calling EMS. A pretest and three posttests-one immediately following the presentation, one at 3 months, and a third at 6 months-were administered. Responses from 282 students were evaluable. Significant improvements (p < .001) in knowledge were found through all posttests in identifying what parts of the body stroke affected and through the first two posttests in recognizing symptoms stroke victims experienced. Students demonstrated at pretest a high awareness of EMS and 911 (97.5%) and showed slight, but not significant, improvement over time.

A Randomized Controlled Trial of Oral Versus Intravenous Administration of a Nonnarcotic Analgesia Protocol Following Pediatric Craniosynostosis Corrections on Nausea and Vomiting Rates.

BACKGROUND: The authors' center uses a nonnarcotic postoperative regimen following craniosynostosis corrections. Despite opioid avoidance, the authors noted that some children still experienced nausea and vomiting following the oral administration of either acetaminophen or ibuprofen. This study sought to evaluate whether intravenous administration of these medications might reduce nausea and vomiting rates. METHODS: A total of 50 children undergoing craniosynostosis corrections were prospectively randomized to a control group given only oral ibuprofen (10 mg/kg) and acetaminophen (15 mg/kg), or a treatment group given only intravenous ketorolac (0.5 mg/kg) and acetaminophen (15 mg/kg). All patients were assessed for postoperative nausea and vomiting by a blinded research nurse. RESULTS: Twenty-eight patients randomized to the oral control group, and 22 to the intravenous treatment group. No statistically significant differences were identified between groups, including: age, weight, sex, before history of severe postoperative nausea and vomiting, or procedure. With similar anesthesia times there was significantly more vomiting episodes in the oral group (71% versus 41%). Using a multivariate logistic regression, controlling for age, weight and procedure, the odds ratio for vomiting in the oral control versus intravenous experimental groups was 3.61 (95% CI 1.11-1.76; P = 0.033), and for postoperative nausea was 14.0 (95% CI 1.40-71.69, P = 0.010). CONCLUSIONS: The authors found a significant reduction in nausea and vomiting among children randomized to receive intravenous medications. In addition, the intravenous delivery of medications has the theoretical advantage of insuring an effective full dose delivery. Based on these findings, our standard process is to preferentially manage all children following craniosynostosis corrections with intravenous nonnarcotics.

Cyclic loading biomechanical analysis of the pullout strengths of rotator cuff and glenoid anchors: 2013 update.

PURPOSE: The purpose of this study was to evaluate the biomechanical and design characteristics of newer suture anchors under cyclic loading. METHODS: Suture anchors were tested in fresh porcine cortical and cancellous bone by cyclic loading (10 to 100 N for 200 cycles) followed by destructive testing parallel to the insertion axis at 12.5 mm per second. End points included ultimate failure load, displacement at 100 and 200 cycles, failure mode, and stiffness. Anchors tested included ReelX (Stryker Endoscopy, San Jose, CA); Footprint Ultra PK (4.5 and 5.5 mm) (Smith & Nephew, Andover, MA); TwinFix (4.5, 5.5, and 6.5 mm made from polyether ether ketone [PEEK], hydroxyapatite [HA], and titanium [Ti]) (Smith & Nephew Endoscopy, Andover, MA); Morphix (2.5 and 5.5 mm) (MedShape Solutions, Atlanta, GA); CrossFT BC (ConMed-Linvatec, Largo, FL); JuggerKnot (1.5 and 2.8 mm) (Biomet Sports Medicine, Warsaw, IN); Healicoil (Smith & Nephew Endoscopy, Andover, MA); Quattro (X, Link, and GL) (Cayenne Medical, Scottsdale, AZ); Healix (Biocryl Rapide [BR], PEEK, and Ti) (DePuy Mitek, Raynham, MA); Twin Loop (3.5 mm, PEEK) (Stryker Endoscopy, San Jose, CA); PressFT (2.1 and 2.6 mm) (ConMed Linvatec, Largo FL); Y-Knot (ConMed Linvatec, Largo FL); Gryphon (BR and PEEK) (DePuy Mitek, Raynham, MA); and Iconix (1, 2, and 3) (Stryker Endoscopy, San Jose, CA). RESULTS: Rotator cuff anchors showed greater failure loads than did glenoid anchors in metaphyseal bone (rotator cuff anchors 448 N v glenoid anchors 296 N) (P = .001) and cancellous bone (rotator cuff anchors 435 N v glenoid anchors 225 N) (P < .001). No anchors reached 5 mm of displacement during cyclic loading. TwinFix anchors showed greater displacement at 100 (P = .014) and 200 cycles (P = .036) than did other rotator cuff anchors, although the ReelX and Morphix showed the greatest displacements. Rotator cuff anchors failed principally by eyelet breaking, whereas glenoid anchors failed more often by anchor pullout than by any other mode. No differences in stiffness were observed across the different rotator cuff and glenoid anchors tested. CONCLUSIONS: Rotator cuff anchors showed higher failure strengths than did glenoid anchors, regardless of bone type. TwinFix anchors showed more cyclic displacement than did other rotator cuff anchors (except the ReelX and Morphix anchors) and the glenoid anchors tested. The failure mode was dependent on the specific anchor. CLINICAL RELEVANCE: Suture anchor constructs tested showed that failure load is dependent on anchor type (rotator cuff anchor or glenoid anchor) but not on anchor location (cancellous or cortical bone).

A comparison of lateral ankle ligament suture anchor strength.

BACKGROUND: Lateral ankle ligament repairs increasingly use suture anchors instead of bone tunnels. Our purpose was to compare the biomechanical properties of a knotted and knotless suture anchor appropriate for a lateral ankle ligament reconstruction. METHODS: In porcine distal fibulae, 10 samples of 2 different PEEK anchors were inserted. The attached sutures were cyclically loaded between 10N and 60N for 200 cycles. A destructive pull was performed and failure loads, cyclic displacement, stiffness, and failure mode recorded. RESULTS: PushLock 2.5 anchors failed before 200 cycles. PushLock 100 cycle displacement was less than Morphix 2.5 displacement (p<0.001). Ultimate failure load for anchors completing 200 cycles was 86.5N (PushLock) and 252.1N (Morphix) (p<0.05). The failure mode was suture breaking for all PushLocks while the Morphix failed equally by anchor breaking and suture breakage. CONCLUSIONS: The knotted Morphix demonstrated more displacement and greater failure strength than the knotless PushLock. The PushLock failed consistently with suture breaking. The Morphix anchor failed both by anchor breaking and by suture breaking.

Biomechanical testing of suture-based meniscal repair devices containing ultrahigh-molecular-weight polyethylene suture: update 2011.

PURPOSE: To evaluate the biomechanical characteristics of recently introduced ultrahigh-molecular-weight polyethylene suture-based, self-adjusting meniscal repair devices. METHODS: Updating a prior study published in 2009, we made vertical longitudinal cuts 3 mm from the periphery in fresh-frozen adult human menisci to simulate a bucket-handle meniscus tear. Each tear was then repaired by a single repair technique in 10 meniscus specimens. Group 1 menisci were repaired with a vertical mattress suture of No. 2-0 Ethibond (Ethicon, Somerville, NJ). Group 2 menisci were repaired with a vertical mattress suture of No. 2-0 OrthoCord (DePuy Mitek, Raynham, MA). Group 3 menisci were repaired with a single OmniSpan device with No. 2-0 OrthoCord suture (DePuy Mitek). Group 4 menisci were repaired with a single Meniscal Cinch device with No. 2-0 FiberWire suture (Arthrex, Naples, FL). Group 5 menisci were repaired with a single MaxFire device inserted with the MarXmen gun (Biomet Sports Medicine, Warsaw, IN). Group 6 menisci were repaired with a Sequent device with No. 0 Hi-Fi suture (ConMed Linvatec, Largo, FL) in a "V" suture configuration. Group 7 menisci were repaired with a single FasT-Fix 360 device (Smith & Nephew Endoscopy, Andover, MA). By use of a mechanical testing machine, all samples were preloaded at 5 N and cycled 200 times between 5 and 50 N. Those specimens that survived were destructively tested at 5 mm/min. Endpoints included maximum load, displacement, stiffness, and failure mode. RESULTS: Mean failure loads were as follows: Ethibond suture, 73 N; OrthoCord suture, 88 N; OmniSpan, 88 N; Cinch, 71 N; MarXmen/MaxFire, 54 N; Sequent, 66 N; and FasT-Fix 360, 60 N. Ethibond was stronger than MarXmen/MaxFire. The mean displacement after 100 cycles was as follows: Ethibond, 2.58 mm; OrthoCord, 2.75 mm; OmniSpan, 2.51 mm; Cinch, 2.65 mm; MarXmen/MaxFire, 3.67 mm; Sequent, 3.35 mm; and FasT-Fix 360, 1.13 mm. The MarXmen/MaxFire showed greater 100-cycle displacement than Ethibond and FasT-Fix 360. No difference in stiffness existed for these devices, and failure mode varied without specific trends. CONCLUSIONS: The biomechanical properties of meniscal repairs using the OmniSpan, Cinch, Sequent, and FasT-Fix 360 devices are equivalent to suture repair techniques. However, the MarXmen/MaxFire meniscal repair device showed significantly lower failure loads and survived less cyclic loading in the human cadaveric meniscus than other tested repairs. CLINICAL RELEVANCE: Most commercially available devices for all-inside meniscal repair using ultrahigh-molecular-weight polyethylene suture provide fixation comparable to the classic vertical mattress suture repair technique in human cadaveric meniscus.

Influence of surgical volume on outcomes in low-risk patients undergoing isolated surgical aortic valve replacement.

BACKGROUND: Intermediate- and high-risk patients undergoing isolated surgical aortic valve replacement have superior outcomes at higher-volume compared with lower-volume hospitals. This study examines the impact of hospital volume on outcomes in low-risk patients undergoing aortic valve replacement. METHODS: Using data from our 29 North Texas hospital collaborative, we examined 2066 low-risk cases (Society of Thoracic Surgeons Predicted Risk of Mortality of ≤3%) undergoing aortic valve replacement surgery between January 1, 2012, and December 31, 2017. Cases from 3 high-volume hospitals (≥200 aortic valve replacement cases total) and 26 low-volume hospitals (<200 cases total) were examined. RESULTS: Some 53.5% of the cases were at high-volume hospitals. No statistical differences were seen in the Predicted Risk of Mortality or pertinent demographics between the high-volume and low-volume hospitals. Significant differences in outcomes were seen between the 2 groups in operative mortality (2.28% vs 1.19%, P = .007), renal failure (2.14% vs 1.00%, P = .003), and readmission within 30 days (9.72% vs 6.25%, P < .001) when comparing low-volume with high-volume hospitals. In patients undergoing aortic valve replacement, undergoing the procedure in a low-volume hospital was an independent predictor for operative mortality (odds ratio, 1.95; 95% confidence interval, 1.20-3.20; P = .008) and renal failure (odds ratio, 2.25; 95% confidence interval, 1.33-3.81; P = .003). CONCLUSIONS: Operative mortality in low-risk patients undergoing aortic valve replacement is higher in low-volume compared with high-volume hospitals. The probability of a major complication, such as renal failure, is also greater in low-volume hospitals. The relationship between volume and outcomes in low-risk patients will require more research to understand the causes and design appropriate interventions.

Biomechanical analysis of pullout strengths of rotator cuff and glenoid anchors: 2011 update.

PURPOSE: To evaluate the biomechanical and design characteristics of newer suture anchors. METHODS: Suture anchors were tested in fresh porcine metaphyseal cortex and cancellous troughs by use of an established protocol. A mechanical testing machine applied tensile loads parallel to the axis of insertion at 12.5 mm/s until failure, and mean anchor failure strengths were calculated. The mode of failure was recorded. Rotator cuff anchors tested included the Doubleplay and Opus SpeedScrew (ArthroCare Sports Medicine, Sunnyvale, CA); PEEK Intraline and PEEK Zip (Stryker, San Jose, CA); Paladin, SuperRevo FT, and CrossFT (ConMed Linvatec, Largo, FL); Piton (Tornier, Warsaw, IN); Ti Screw, ALLthread PEEK, LactoScrew, ALLthread Ti, and ALLthread PEEK knotless (Biomet Sports Medicine, Warsaw, IN). Glenoid anchors included the Gryphon BR P (DePuy-Mitek, Raynham, MA) and JuggerKnot 1.4 (Biomet Sports Medicine). RESULTS: Mean cortical failure loads for cuff anchors were as follows: Doubleplay 5.0, 279 N; Doubleplay 6.5, 338 N; Opus SpeedScrew 5.5, 356 N; Opus SpeedScrew 6.5, 336 N; PEEK Intraline 5.5, 263 N; PEEK Intraline 6.5, 344 N; PEEK Zip 5.5, 435 N; PEEK Zip 6.5, 502 N; Paladin 5.0, 500 N; Paladin 6.5, 521 N; SuperRevo FT, 496 N; CrossFT, 569 N; Piton, 379 N; Ti Screw 5.0, 457 N; Ti Screw 6.5, 443 N; ALLthread PEEK 5.5, 476 N; LactoScrew 5.5, 403 N; ALLthread Ti 5.0, 526 N; ALLthread Ti 6.5, 653 N; and ALLthread PEEK knotless, 441 N). Mean cortical failure loads for glenoid anchors were 161 N for Gryphon BR P and 239 N for JuggerKnot 1.4. Mean cancellous bone failure loads for cuff anchors were Doubleplay 5.0, 263 N; Doubleplay 6.5, 340 N; Opus SpeedScrew 5.5, 356 N; Opus SpeedScrew 6.5, 344 N; PEEK Intraline 5.5, 274 N; PEEK Intraline 6.5, 327 N; PEEK Zip 5.5, 401 N; PEEK Zip 6.5, 396 N; Paladin 5.0, 427 N; Paladin 6.5, 491 N; SuperRevo FT, 483 N; CrossFT, 547 N; Piton, 365 N; Ti Screw 5.0, 420 N; Ti Screw 6.5, 448 N; ALLthread PEEK 5.5, 475 N; LactoScrew 5.5, 435 N; ALLthread Ti 5.0, 512 N; ALLthread Ti 6.5, 612 N; and ALLthread PEEK knotless, 466 N). Mean cancellous failure loads for glenoid anchors were 117 N for Gryphon BR P and 194 N for JuggerKnot 1.4. None of the anchors had pullout as the predominant failure mode. Eyelet failure was the predominant failure mode for Doubleplay, Opus SpeedScrew, PEEK Intraline, Gryphon BR P, ALLthread Ti 6.5, ALLthread PEEK 5.5, and LactoScrew. CONCLUSIONS: Failure load was not dependent on anchor location (cancellous or cortical bone) (P = .58) but was dependent on anchor type (cuff anchor or glenoid anchor) (P < .001). CLINICAL RELEVANCE: Whereas larger fully threaded screw anchors designed for rotator cuff repair showed higher failure strengths than smaller non-screw anchors designed for glenoid repairs (P < .05), the larger version of a screw anchor for a cuff repair did not provide a statistically greater failure load than the smaller screw anchor.

Mitral valve surgery: comparison of outcomes in matched sternotomy and port access groups.

BACKGROUND AND AIM OF THE STUDY: The 30-day outcomes were compared between matched groups of patients undergoing mitral valve procedures through Port Access (femoral cannulation, percutaneous retrograde cardioplegia and aortic occlusion), and through a sternotomy. METHODS: By using a Society of Thoracic Surgeons (STS)-certified, audited database, a total of 1108 patients was identified who were operated on between January 1996 and November 2008. A total of 608 mitral valve repair (MV-Rpr) patients (including 241 with Port Access procedures) and 500 mitral valve replacement (MVR) patients (including 45 with Port Access procedures) was included. Matching groups were created for 177 MV-Rpr patients (matched on preoperative cerebrovascular accident (CVA), previous coronary artery bypass grafting (CABG) and valve procedures, urgent operative status, mitral stenosis, heart failure, NYHA class IV, and age) and for MVR patients with 43 matches (matched for previous CABG surgery, operative status, NYHA class IV, and mitral insufficiency). RESULTS: Patients with Port Access procedures for MV-Rpr had a shorter length of hospital stay (5.4 +/- 2.8 versus 7.3 +/- 5.8 days), less postoperative ventilator usage (8.4 +/- 36.0 versus 24.8 +/- 81.6 h) and a shorter intensive care unit (ICU) stay (34.0 +/- 40.5 versus 81.7 +/- 133.8 h) when compared to sternotomy cases. Port Access also resulted in fewer patients requiring postoperative ventilation (50.3% versus 76.9%; p < 0.001) or reoperation for bleeding (2.3% versus 6.8%; p = 0.048). In MVR patients, Port Access use led to reductions in mortality (11.6% versus 0%; p = 0.021), ventilation time (13.8 +/- 40.3 versus 38.1 +/- 83.0 h), ICU stay (51.9 +/- 83.4 versus 152.4 +/- 125.0 h) and postoperative hospital stay (8.2 +/- 8.0 versus 11.0 +/- 8.6 days). In both groups, the cross-clamp time was longer with Port Access (107.7 +/- 26.8 versus 92.8 +/- 35.2 min for MV-Rpr; 130.2 +/- 44.2 versus 102.7 +/- 64.6 min for MVR). CONCLUSION: The performance of mitral valve surgery through a Port Access approach led to a reduction in ICU time, ventilator time, and hospital stay when compared to sternotomy. No increase in morbidity was observed with Port Access compared to sternotomy.

Biomechanical advantages of triple-loaded suture anchors compared with double-row rotator cuff repairs.

PURPOSE: To evaluate the strength and suture-tendon interface security of various suture anchors triply and doubly loaded with ultrahigh-molecular weight polyethylene-containing sutures and to evaluate the relative effectiveness of placing these anchors in a single-row or double-row arrangement by cyclic loading and then destructive testing. METHODS: The infraspinatus muscle was reattached to the original humeral footprint by use of 1 of 5 different repair patterns in 40 bovine shoulders. Two single-row repairs and three double-row repairs were tested. High-strength sutures were used for all repairs. Five groups were studied: group 1, 2 triple-loaded screw suture anchors in a single row with simple stitches; group 2, 2 triple-loaded screw anchors in a single row with simple stitches over a fourth suture passed perpendicularly ("rip-stop" stitch); group 3, 2 medial and 2 lateral screw anchors with a single vertical mattress stitch passed from the medial anchors and 2 simple stitches passed from the lateral anchors; group 4, 2 medial double-loaded screw anchors tied in 2 mattress stitches and 2 push-in lateral anchors capturing the medial sutures in a "crisscross" spanning stitch; and group 5, 2 medial double-loaded screw anchors tied in 2 mattress stitches and 2 push-in lateral anchors creating a "suture-bridge" stitch. The specimens were cycled between 10 and 180 N at 1.0 Hz for 3,500 cycles or until failure. Endpoints were cyclic loading displacement (5 and 10 mm), total displacement, and ultimate failure load. RESULTS: A single row of triply loaded anchors was more resistant to stretching to a 5- and 10-mm gap than the double-row repairs with or without the addition of a rip-stop suture (P < .05). The addition of a rip-stop stitch made the repair more resistant to gap formation than a double row repair (P < .05). The crisscross double row created by 2 medial double-loaded suture anchors and 2 lateral push-in anchors stretched more than any other group (P < .05). CONCLUSIONS: Double-row repairs with either crossing sutures or 4 separate anchor points were more likely to fail (5- or 10-mm gap) than a single-row repair loaded with 3 simple sutures. CLINICAL RELEVANCE: The triple-loaded anchors with ultrahigh-molecular weight polyethylene-containing sutures placed in a single row were more resistant to stretching than the double-row groups.

Cyclic load and failure behavior of arthroscopic knots and high strength sutures.

PURPOSE: To compare the biomechanical performance of several different sutures by evaluating knot security and load to failure strength using different arthroscopic knots. METHODS: Eight different No. 2 sutures (Ethibond [Ethicon, Somerville, NJ], FiberWire [Arthrex, Naples, FL], Orthocord [DePuy-Mitek, Norwood, MA], Hi-Fi [ConMed Linvatec, Largo, FL], Ultrabraid [Smith & Nephew, Andover, MA], ForceFiber [Stryker Endoscopy, San Jose, CA], MagnumWire [ArthroCare, Sunnyvale, CA], and MaxBraid PE [Arthrotek, Warsaw, IN]) were tied arthroscopically into standardized loops using 6 different knots (Weston, Tennessee slider, Duncan, SMC, Revo, and San Diego knot) 10 times each. The suture loops were pretensioned to 10N, cycled between 10N and 45N for 1,000 cycles, and loaded to failure. The failure load for each suture, each knot, and slippage trend during cyclic loading was recorded. RESULTS: The Revo and SMC knots (group A) were stronger than the Tennessee and San Diego knots (group B), which were stronger than the Weston knot, which was stronger than the Duncan loop (P < .05). This pattern also coincided with the loads at which these knots slipped. Evaluating the sutures showed that Ethibond had lower failure loads than all other sutures and FiberWire showed statistically higher loads (P < .05). Duncan loops (97.5%) and Weston knots (86.3%) slipped more than other knots (P < .001), while the SMC and Revo knots slipped least. Ethibond sutures were least likely to slip. CONCLUSIONS: The Duncan loop and Weston knot were more likely to slip than all other knots, and caution should be exercised when tying them with high-strength sutures. The Revo, Tennessee slider, San Diego, and SMC knots were least likely to slip (P < .001). CLINICAL RELEVANCE: While stronger than braided polyester sutures, newer sutures containing ultra-high molecular weight polyethylene have a greater tendency to slip. Backing up knots with 4 reversed half hitches with switched posts does not guarantee knot security.

Biomechanical testing of new meniscal repair techniques containing ultra high-molecular weight polyethylene suture.

PURPOSE: To evaluate the biomechanical characteristics of current meniscal repair techniques containing ultra high-molecular weight polyethylene (UHMWPE) suture with and without cyclic loading. METHODS: Vertical longitudinal cuts made in porcine menisci were secured with a single repair device. Noncycled and cycled (500 cycles) biomechanical tests were performed on the following groups: group 1, No. 2-0 Mersilene vertical suture (Ethicon, Somerville, NJ); group 2, No. 2-0 Orthocord vertical suture (DePuy Mitek, Westwood, MA); group 3, No. 0 Ultrabraid vertical suture (Smith & Nephew Endoscopy, Andover, MA); group 4, No. 2-0 FiberWire vertical suture (Arthrex, Naples, FL); group 5, vertically oriented mattress suture by use of an Ultra FasT-Fix device (Smith & Nephew Endoscopy) with No. 0 Ultrabraid; group 6, vertically oriented mattress suture by use of a RapidLoc A2 device (DePuy Mitek) with No. 2-0 Orthocord suture; group 7, vertically oriented stitch by use of a MaxFire device with MaxBraid PE suture (Biomet Sports Medicine, Warsaw, IN); and group 8, an obliquely oriented stitch of No. 0 UHMWPE suture inserted by use of a CrossFix device (Cayenne Medical, Scottsdale, AZ). Endpoints were failure loads, failure modes, stiffness, and cyclic displacement. RESULTS: Mean single-pull loads were calculated for Ultra FasT-Fix (121 N), FiberWire (110 N), MaxFire (130 N), Mersilene (84 N), Orthocord (124 N), RapidLoc A2 (86 N), CrossFix (77 N), and Ultrabraid (109 N). After 500 cyclic loads, the Orthocord (222 N) repair was stronger than the others: Ultra FasT-Fix (110 N), FiberWire (117 N), MaxFire (132 N), Mersilene (89 N), RapidLoc A2 (108 N), CrossFix (95 N), and Ultrabraid (126 N) (P < .05). Ultrabraid suture showed significantly more elongation over 500 cycles than the other repairs (P < .05). The principal failure mode associated with the single destructive pull (suture breakage) changed to pulling through the meniscus after cyclic loading for most devices. Knot slippage or device failure was seldom observed as the failure mode with these techniques. CONCLUSIONS: Self-adjusting, UHMWPE suture-containing meniscal repair devices (Ultra FasT-Fix, RapidLoc A2, and MaxFire) were comparable to the isolated UHMWPE-containing suture repairs on single-failure load testing. UHMWPE-containing suture repairs are stronger than braided polyester suture repairs, but pure UHMWPE suture (Ultrabraid) elongated more during cycling. Orthocord suture is significantly stronger than the other meniscal repair techniques after cyclic loading (P < .05). CLINICAL RELEVANCE: Meniscal repair techniques using UHMWPE containing sutures provide greater strength than earlier generations of meniscal repair techniques.

Ultimate tensile failure loads of a human dermal allograft rotator cuff augmentation.

PURPOSE: The purpose of this study was to examine the failure mode of supraspinatus tendon repairs with and without human dermal allograft augmentation. METHODS: Ten matched pairs of human cadaveric supraspinatus muscles and tendons were detached from their greater tuberosity insertions and then reattached with four simple sutures in 2 suture anchors as a control group. One shoulder from each matched pair was augmented with human dermal allograft secured to the humerus and the supraspinatus tendon using the same sutures and suture anchors. Additional interrupted mattress sutures secured the edges of the dermal allograft to the supraspinatus tendon. Each construct was preloaded at 10 N and then cyclically loaded between 10 N and 100 N for 10 cycles at 20 N/s followed by destructive testing at 33 mm/s. Force and displacement were recorded. RESULTS: The mean failure strengths for the control and augmented constructs were 273 +/- 116 N and 325 +/- 74 N, respectively (P = .047). No significant displacement occurred during the cyclic phase, and no anchors failed. These constructs failed by 2 different mechanisms: tendon-suture interface failure (8/10 non-augmented repairs and 6/10 augmented repairs) and suture breakage (2/10 non-augmented repairs and 4/10 augmented repairs). CONCLUSIONS: This examination of the failure characteristics and ultimate failure load of supraspinatus tendon tears augmented with GraftJacket (Wright Medical Technology, Arlington, TN) supported the study hypothesis that a human dermal allograft significantly increases the strength of a repaired tendon. CLINICAL RELEVANCE: The human dermal allograft can be expected to significantly increase the initial strength of a rotator cuff repair.

Suture anchor materials, eyelets, and designs: update 2008.

PURPOSE: Our purpose was to evaluate recently introduced sutures and suture anchors for single pull load to failure strength and failure mode. METHODS: Suture anchors were tested in fresh porcine metaphyseal cortex and cancellous troughs using an established protocol. An Instron machine applied tensile loads parallel to the axis of insertion at a rate of 12.5 mm per second until failure and mean anchor failure strengths were calculated. The mode of failure was recorded (anchor pullout, suture eyelet cut out, or suture failure). Anchors tested included the Kinsa, Kinsa RC, BioRaptor 2.3 PK, TwinFix PK FT 5.5 and 6.5, BioCleat, Healix Peek, VersaLok, BioKnotless, BioKnotless BR, Corkscrew FT III, SwiveLock C, and PEEK SutureTak. RESULTS: The mean cortical failure loads were as follows: Kinsa (219 N), Kinsa RC (222 N), BioRaptor 2.3 PK (172 N), TwinFix PK FT 5.5 (491 N) and 6.5 (503 N), BioCleat (218 N), Healix Peek (407 N), VersaLok (376 N), BioKnotless (249 N), BioKnotless BR (265 N), Corkscrew FT III (386 N), SwiveLock C (712 N), and PEEK SutureTak (168 N). Pullout was the predominant failure mode for the VersaLok, BioKnotless, BioKnotless BR, and BioRaptor 2.3PK anchors. Eyelet failure was the predominant failure mode for the Kinsa, Kinsa RC, BioCleat, Healix Peek, Corkscrew FT III, SwiveLock C, and PEEK SutureTak. CONCLUSIONS: The newer anchors showed markedly increased load to failure strengths. Two or more high-strength sutures are commonly used as well as new anchor materials (PEEK and Biocryl Rapide), new eyelet designs, and the increased use of a "knotless" concept. CLINICAL RELEVANCE: An anchor which fails principally by pull out at a low load to failure is at risk for creating an intra-articular loose body.

Insertion force of articular cartilage transplantation systems.

This study compared the insertion force, plug harvest consistency, and recipient site creation consistency of 4 different articular cartilage transplantation systems (COR, OATS, Mosaicplasty, and New COR2) during plug insertion using a single-impaction technique. Maximum insertion forces fell into 3 statistically different groups: group 1, OATS 8-mm (238 N) and 10-mm (215 N) systems; group 2, COR 6-mm (133 N) and 8-mm (176 N), Mosaicplasty, 6.5-mm (147 N) and 8.5-mm (134 N), and OATS 6-mm (137 N) systems; and group 3, New COR2 6-mm (68 N), 8-mm (55 N), and 10-mm (54 N) systems (P < or = .05). OATS compaction pressures were 172 N (6 mm), 353 N (8 mm), and 550 N (10 mm). COR, New COR2, and Mosaicplasty donor plugs were created consistently, but the Mosaicplasty system required toggling. OATS plugs had inconsistent lengths but required no toggling. Insertion forces with the New COR2 system were statistically the lowest. Compaction significantly increased surface forces.

A biomechanical study of Achilles tendon repair augmentation using GraftJacket matrix.

BACKGROUND: Ruptured Achilles tendons benefit from primary repair by decreasing re-rupture rates and allowing earlier range of motion. A stronger repair might allow for more aggressive rehabilitation decreasing postoperative stiffness, calf atrophy, and repair site gapping. The hypothesis of this study was that human dermal allograft augmentation of an Achilles repair would significantly increase repair strength and stiffness. This study evaluated strength and stiffness of an Achilles tendon repair augmented with a human dermal allograft (GraftJacket). MATERIALS AND METHODS: Eight matched pairs of human cadaver legs were used. Simulated Achilles tendon ruptures were created 4 cm proximal to the calcaneal insertion. All tendons were repaired with a Krackow locking loop stitch. One of each matched pair was augmented with GraftJacket. Each construct was pre-loaded at 10 N and cyclically loaded (20 cycles) from 2 N to 30 N at a rate of 5 N/sec on an Instron machine. This was followed by testing to failure at a displacement rate of 6 mm/sec. RESULTS: The ultimate failure load in the control group was 217 N +/- 31 compared to 455 N +/- 76.5 in the GraftJacket group (p < 0.001). The mean stiffness in the control group was 4.3 +/- 0.83 N/mm which was significantly less than the 12.99 +/- 5.34; N/mm in the GraftJacket group (p = 0.002). CONCLUSION: The augmentation of an Achilles tendon repair with GraftJacket significantly increased repair strength and stiffness. CLINICAL SIGNIFICANCE: These findings suggest that a GraftJacket augmented Achilles tendon repair could acutely withstand a more aggressive rehabilitation program, potentially decreasing ankle stiffness and allowing earlier return to full activities.

Meniscal tear biomechanics: loads across meniscal tears in human cadaveric knees.

This study examined the forces during motion across human meniscal tears. Longitudinal cuts were created in 6 human cadaveric knees at the red-white junction of the medial and lateral menisci into which a pressure transducer was placed. Pressure data were gathered with the knees at neutral, internal rotation, and external rotation and matched to knee flexion. The meniscal cuts were compressed throughout the range of motion. No distraction pressures were observed. Therefore, meniscal tear displacement does not occur with knee motion and a meniscal repair device load-to-failure strength may be less important than the device's ability to accurately reduce a meniscal tear and avoid shear stress.

Can use of an administrative database improve accuracy of hospital-reported readmission rates?

OBJECTIVES: Readmission rates after cardiac surgery are being used as a quality indicator; they are also being collected by Medicare and are tied to reimbursement. Accurate knowledge of readmission rates may be difficult to achieve because patients may be readmitted to different hospitals. In our area, 81 hospitals share administrative claims data; 28 of these hospitals (from 5 different hospital systems) do cardiac surgery and share Society of Thoracic Surgeons (STS) clinical data. We used these 2 sources to compare the readmissions data for accuracy. METHODS: A total of 45,539 STS records from January 2008 to December 2016 were matched with the hospital billing data records. Using the index visit as the start date, the billing records were queried for any subsequent in-patient visits for that patient. The billing records included date of readmission and hospital of readmission data and were compared with the data captured in the STS record. RESULTS: We found 1153 (2.5%) patients who had STS records that were marked "No" or "missing," but there were billing records that showed a readmission. The reported STS readmission rate of 4796 (10.5%) underreported the readmission rate by 2.5 actual percentage points. The true rate should have been 13.0%. Actual readmission rate was 23.8% higher than reported by the clinical database. Approximately 36% of readmissions were to a hospital that was a part of a different hospital system. CONCLUSIONS: It is important to know accurate readmission rates for quality improvement processes and institutional financial planning. Matching patient records to an administrative database showed that the clinical database may fail to capture many readmissions. Combining data with an administrative database can enhance accuracy of reporting.

Establishing a Dedicated General Thoracic Surgery Subspecialty Program Improves Lung Cancer Outcomes.

BACKGROUND: Various factors may influence outcomes after lobectomy for lung cancer. Postgraduate subspecialty training in general thoracic surgery with a focus on minimally invasive surgery (MIS) and thoracic oncology was completed by an established cardiothoracic surgeon on the hospital staff in July 2007, and principles emphasized in that training were incorporated into practice through formation of a subspecialty program. We hypothesized that establishing a dedicated general thoracic surgeon-lead subspecialty program, with focus on MIS and thoracic oncology, would improve short-term and long-term outcomes. METHODS: Patients entered into the hospital cancer registry have survival status updated annually through correspondence with patients, physicians, and searches of the Social Security Death Index and obituaries. The registry was queried for all patients undergoing lobectomy for lung cancer, 2002 to 2013, and divided into two groups for comparison, before and after, based on operation date relative to January 2008. Patients (n = 279) who had lobectomy for lung cancer were identified in the registry. Data included surgical approach (percent of video-assisted thoracoscopy [VATS]), pathologic stage, number of lymph nodes and stations sampled, hospital length of stay (LOS), and survival. χ2 statistics were used for proportions, t tests for continuous variables, and a nonparametric test for LOS. A Cox proportional hazard model was created, and survival curves were constructed using time between operation and death or last follow-up. RESULTS: Patients having lobectomy in the after group had substantially more VATS procedures (53.9% versus 9.5%), decreased LOS (median 3.5 versus 7.0 days), greater mean total lymph nodes (9.0 versus 6.3), and nodal stations (4.2 versus 2.8) sampled per patient. Thirty-day, 90-day, and 1-year survival were similar in both groups. Overall survival was better in the after group (hazard ratio [HR] 0.41, 95% confidence interval: 0.25 to 0.68), and this survival benefit remained statistically significant when comparing groups stratified by lung cancer stage (stage I: HR 0.46, stage II: HR 0.32, combined stage III to IV: HR 0.19). CONCLUSIONS: Establishing a dedicated general thoracic surgeon-lead subspecialty program, with focus on MIS and thoracic oncology, can substantially improve short-term outcomes with increased VATS utilization, decreased LOS, and increased lymph node sampling. Long-term survival was also significantly improved.

Comparison of Outcomes of Operative Therapy for Acute Type A Aortic Dissections Provided at High-Volume Versus Low-Volume Medical Centers in North Texas.

Immediate surgery is standard therapy for acute type A aortic dissections (TAAD). Because of its low incidence, many smaller cardiac surgery programs do not routinely perform this procedure because it may negatively affect outcomes. Many high-risk, low-volume (LV) surgical procedures are now preferentially performed in reference centers. We compared the outcomes of surgery for TAAD in high-volume (HV) and LV centers in a single metropolitan area to determine the optimal setting for treatment. Thirty-five of the 37 cardiac surgery programs in the Dallas Ft. Worth metropolitan area participate in a regional consortium to measure outcomes collected in the Society of Thoracic Surgeons Adult Cardiac Database. From January 01, 2008, to December 31, 2014, 29 programs had treated TAAD. Those programs performing at least 100 operations for TAAD were considered HV centers and the others LV. Surgery for TAAD was performed in 672 patients over the 7-year study period with HV centers performing 469 of 672 (70%) of the operations. Despite similar preoperative characteristics, operative mortality was significantly lower in HV versus LV centers (14.1% vs 24.1%; p = 0.001). There was no significant difference in postoperative paralysis rates (2.6% vs 4.5%; p = 0.196), stroke rates (10.7% vs 9.4%; p = 0.623), or 30-day readmission rates (12.1% vs 15.5%; p = 0.292). An improved survival rate in HV centers was maintained over a 5-year follow-up period. Surgery for TAAD in a single large metropolitan area was most commonly performed in HV centers. In conclusion, the treatment of acute thoracic aortic dissection is recommended to be performed in reference centers because of lower early and midterm mortality.