Mason-Allen Stitch Research Articles

Rotator Cuff Repairs Using Double-Row Modified Mason-Allen Stitches Resulted in Superior Clinical Outcomes at 2-Year Follow-Up Compared to the Double-Row Suture-Bridge Technique: A Case-Control Matching Study

Rotator Cuff Repairs Using Double-Row Modified Mason-Allen Stitches Resulted in Superior Clinical Outcomes at 2-Year Follow-Up Compared to the Double-Row Suture-Bridge Technique: A Case-Control Matching Study

Radiologic and clinical outcomes of an arthroscopic bridging graft for irreparable rotator cuff tears with a modified MasonAllen stitch using a plantaris tendon autograft: a case series with minimum 2-year outcomes.

Surgical management of a massive rotator cuff tear (RCT) is always challenging. This study describes the clinical and radiological outcomes of patients who underwent bridging grafts using a plantaris tendon for an irreparable RCT. Thirteen patients with a massive RCT were treated with arthroscopic interposition of a folded plantaris tendon autograft between June 2017 and January 2020. For clinical evaluation, a visual analog scale (VAS), American Shoulder and Elbow Surgeons (ASES) score, Disabilities of the Arm, Shoulder, and Hand (DASH) score, Constant-Murley score, and range of motion values were collected. For radiographic evaluation, standardized magnetic resonance imaging and ultrasonography were performed to check the integrity of the interposed tendon. A statistically significant improvement at the final follow-up was evident in scores for the VAS (-3.0, P=0.003), ASES (24.9, P=0.002), D ASH (-20.6, P=0.001), and Constant-Murley values (14.2, P=0.010). In addition, significant improvement was shown in postoperative flexion (17.3°, P=0.026) and external rotation (27.7°, P<0.001). In postoperative radiologic evaluations, the interposed tendons were intact at the last examination in 12 of the 13 patients. No complications related to donor sites were reported. An arthroscopic bridging graft for irreparable RCTs using a modified Mason-Allen stitch and a plantaris autograft resulted in improved short-term radiological and clinical outcomes. Graft integrity was maintained for up to 2 years in most patients. Level of evidence: IV.

Biomechanical comparison of pectoralis major repair techniques: A systematic review and meta-regression.

There are many surgical techniques when repairing pectoralis major tears. However, there is no clear consensus on which repair technique is biomechanically superior. Our purpose was to perform a systematic review and meta-regression to evaluate the most biomechanically superior pectoralis major repair technique. We performed a systematic review and meta-regression of six human cadaveric biomechanical studies evaluating fixation techniques for pectoralis major repairs. The primary outcome was the ultimate failure load. Covariates included cadaveric age, bone mineral density, implants, suture, and stitch method. Meta-regression accounted for differences in variables. Compared with Krackow/Bunnell stitch method, the modified Mason-Allen stitch demonstrated a decrease in ultimate failure load by 220.6 N (95% CI, -273.0 to -168.2; p = <0.001). No differences were found between Krackow/Bunnell and whipstitch. There was an increase in ultimate failure load when utilizing suture tape by 206.6 N (95% CI, 139.5-273.7, p < 0.001). Suture anchors had a decrease in ultimate failure load by 88.1 N (95% CI, -153.4 to -22.8, p = 0.008) when compared to transosseous sutures. No differences were found between transosseous sutures and unicortical buttons. We found the combination of suture tape in a whipstitch or Krackow/Bunnell stitch utilizing transosseous sutures or unicortical buttons is the most biomechanically superior construct for pectoralis major repairs.

Use of an Arthroscopic Bridging Graft for Irreparable Rotator Cuff Tears With the Modified Mason–Allen Stitch Using a Tendon Autograft

We describe a technique for treating irreparable rotator cuff tears (RCTs) by bridging grafts with a long tendon autograft. In this technique, the plantaris tendon is harvested and prepared in a Y-shaped graft. The folded end of the graft is anchored to the greater tubercle and the other 2 limbs are fixed to rotator cuff tissue using modified Mason-Allen stitches. The autograft can decrease the tension on the repair of irreparable RCTs and has biological superiority. Our clinical experience indicates this technique will bring superior integrity to irreparable RCT repairs.

Arthroscopic Subscapularis Tendon Repair Using the Mason-Allen Technique.

Arthroscopic rotator cuff repair has recently been popularized for treating tears. In a biomechanical trial, the Mason-Allen stitch improved the fixation quality of poorly vascularized tendons. The use of this technique involving the subscapularis tendon remains rare. The aim of this study was to evaluate the clinical outcomes of Mason-Allen technique repaired subscapularis tendons. A retrospective research of collected data from 98 patients with subscapularis tears who had undergone arthroscopic repair between May 2015 and December 2018. There were 75 males and 23 females. The mean age was 56.4 ± 9.6 years and the mean follow-up was 12.5 ± 4.0 months. The visual analog scale (VAS), American Shoulder and Elbow Surgeons (ASES) score, and Constant-Murley score were used to analyze shoulder function. An MRI was performed to assess the integrity of the repair. Patients had significantly less pain and a better active range of motion compared with preoperative levels. VAS improved significantly from a preoperative mean of 3.42 to a postoperative mean of 1.91. ASES increased significantly from the preoperative mean of 43.6 to the postoperative mean of 74.5. Seven cases suffered from retears, which were confirmed by an MRI examination. Arthroscopic rotator cuff repair with the Mason-Allen method resulted in a decreased level of pain and satisfied function recovery.

Biomechanical evaluation of self-cinching stitch techniques in rotator cuff repair: The single-loop and double-loop knot stitches.

In rotator cuff repair, strong and reliable suturing is necessary to decrease failure rates. The biomechanics of two self-cinching stitches – the single-loop knot stitch (SLKS) and the double-loop knot stitch (DLKS) – and the modified Mason-Allen stitch (mMAS) were compared. Twenty-seven porcine infraspinatus tendons were randomized among the three stitches. Each was cyclically loaded (10–80–200 N for 50 cycles each) while the gap formation was measured. Next, ultimate load to failure was tested. The gap widths after cyclic loading were 8.72 ± 0.93 mm for the DLKS, 8.65 ± 1.33 mm for the mMAS, and 9.14 ± 0.89 mm for the SLKS, without significant differences. The DLKS showed the highest ultimate load (350.52 ± 38.54 N) compared with the mMAS (320.88 ± 53.29 N; p = 0.304) and the SLKS (290.54 ± 60.51 N; p < 0.05). The DLKS showed similar reliability and better strength compared with the mMAS, while the SLKS showed a slight but not significant decrease in performance. In our experience, the DLKS and SLKS have clinical advantages, as they are easy to perform and the self-cinching loop knot allows the surgeon to grasp degenerative tendon tissue. Initial intraoperative tightening of the suture complex (preloading) before locking is important in order to decrease postoperative elongation.

Effet de l’atélocollagène sur la cicatrisation des réparations de la racine méniscale médiale à l’aide du point Mason–Allen modifié

IntroductionAddition of collagen during medial meniscal root repair (MMRR) may improve meniscal root healing minimizing fibrous scar tissue formation. The purpose of this study was to verify the effect of atelocollagen on MMRR using the modified Mason–Allen stitch when compared with that of the conventional pull-out repair by assessing the clinical and radiological outcomes. HypothesisIt was hypothesized that atelocollagen would enhance the healing effect on the meniscal root following MMRR. Moreover, we presumed that MMRR with atelocollagen application might reduce meniscal extrusion by promoting healing. Materials and methodsA total of 47 patients who underwent MMRR using the modified Mason–Allen stitch between 2015 and 2016 were included, and they were divided into group A (atelocollagen application; n=25) and group R (MMRR without atelocollagen application; n=22). The postoperative clinical outcomes, radiological outcomes, and meniscal root healing and medial compartment cartilage status on follow-up magnetic resonance imaging (MRI) were compared between the two groups. ResultsMean follow-up duration was 26.4±4.8 months in group A and 27.1±5.2 months in group R (p=0.598). Mean duration from surgery to follow-up MRI was 12.5±1.4 months in group A and 12.7±1.2 months in group R (p=0.604). The subjective knee scores improved significantly in both groups at the last follow-up (all, p<0.001). The Kellgren–Lawrence (K-L) grade progressed in 16% and 22.7% in group A and group R, respectively (p=0.351). Follow-up MRI showed progression of cartilage loss in the medial compartment in 28% and 40.9% in group A and group R, respectively (p=0.355). In terms of meniscal root healing, 18 (72%) and 12 (54.5%) patients had complete healing, and 6 (24%) and 8 (36.4%) patients had partial healing in groups A and R, respectively. The mean value of the intrameniscal signal intensity (IMSI) of the meniscal root based on MRI in group A was significantly lower than that in group R (p<0.001). The medial meniscal extrusion in groups A and R decreased by 0.2±0.1mm and 0.1±0.3mm following MMRR without significant differences (p=0.056 and p=0.229, respectively). The IMSI presented significant negative correlations with the root healing status and significant positive correlations with K-L grade progression (p<0.05). DiscussionAtelocollagen application during MMRR yielded lower IMSIs, suggesting better healing, than did conventional pull-out root repair. However, this technique could not demonstrate beneficial effects on meniscal extrusion. Level of evidenceIII, retrospective case-control study.

Arthroscopic Bankart repair: A matched cohort comparison of the modified Mason Allen method and the simple stitch method

IntroductionArthroscopic Bankart repair (ABR) has become a standard treatment for recurrent anterior shoulder dislocation in cases with minimal bone loss. Using the standard Bankart repair technique, the failure rate has been reported to be approximately between 4 and 35%. In addition to the original injury, multiple pathologies can occur after a dislocation including a Bankart lesion, capsular redundancy and bone defects. In cases with no significant bone loss, soft tissue plays a major role in stabilizing the shoulder joint. We hypothesized that effective repair of soft tissue with good inferior capsular shifting and proper capsulolabral restoration can create a proper level of soft tissue tension so the horizontal mattress suture method should improve outcomes. Materials and methodsA retrospective cohort study was conducted by reviewing the records of patients with recurrent anterior instability who underwent ABR at a single institution between January 2009 and December 2017. Demographic information, preoperative radiographic data including glenoid bone loss, Hill-Sachs width, glenoid track and other surgical details were retrieved from the medical records. The patients identified were divided into 2 groups. Group 1 had one modified Mason Allen stitch plus simple stitches, while Group 2 had only simple stitches. Data obtained from the patient included failure rate, patient satisfaction, the ROWE score and Walch-Duplay score at a minimum of 2 years after surgery. Risk factors for failure were also identified. ResultsGroup 1 included 50 patients (mean age 27.2 ± 9.4 years) who underwent modified Mason Allen stitch ABR (median follow-up, 59.2 months; range, 26.2–128.6 months). Group 2 included 30 patients (mean age 26.9 ± 8.5 years) who underwent simple stitch repair ABR (median follow-up, 68.0 months; range, 24.0–127.9 months). All patients met the inclusion criteria. Evaluation at the final follow-up compared Group 1 and Group 2: ROWE score (86.8 vs 76.3, P = 0.001), Walch-Duplay score (87.2 vs 82.0, P = 0.035), respectively. Failure rates were 6% in group 1 compared to 10% in group 2 (P = 0.511). ConclusionsThe modified Mason Allen stitch technique and the simple stitches technique ABR both result in excellent patient satisfaction at a minimum 2-year follow-up. Both techniques successfully restore shoulder stability, but the modified Mason Allen stitch technique results in better functional outcomes. Study designCohort study; level of evidence, 3.

Effect of atelocollagen on the healing status after medial meniscal root repair using the modified Mason–Allen stitch

IntroductionAddition of collagen during medial meniscal root repair (MMRR) may improve meniscal root healing minimising fibrous scar tissue formation. The purpose of this study was to verify the effect of atelocollagen on MMRR using the modified Mason–Allen stitch when compared with that of the conventional pullout repair by assessing the clinical and radiological outcomes. HypothesisIt was hypothesised that atelocollagen would enhance the healing effect on the meniscal root following MMRR. Moreover, we presumed that MMRR with atelocollagen application might reduce meniscal extrusion by promoting healing. Materials and methodsA total of 47 patients who underwent MMRR using the modified Mason–Allen stitch between 2015 and 2016 were included, and they were divided into group A (atelocollagen application; n=25) and group R (MMRR without atelocollagen application; n=22). The postoperative clinical outcomes, radiological outcomes, and meniscal root healing and medial compartment cartilage status on follow-up magnetic resonance imaging (MRI) were compared between the two groups. ResultsMean follow-up duration was 26.4±4.8 months in group A and 27.1±5.2 months in group R (p=0.598). Mean duration from surgery to follow-up MRI was 12.5±1.4 months in group A and 12.7±1.2 months in group R (p=0.604). The subjective knee scores improved significantly in both groups at the last follow-up (all, p<0.001). The Kellgren–Lawrence (K–L) grade progressed in 16% and 22.7% in group A and group R, respectively (p=0.351). Follow-up MRI showed progression of cartilage loss in the medial compartment in 28% and 40.9% in group A and group R, respectively (p=0.355). In terms of meniscal root healing, 18 (72%) and 12 (54.5%) patients had complete healing, and 6 (24%) and 8 (36.4%) patients had partial healing in groups A and R, respectively. The mean value of the intra-meniscal signal intensity (IMSI) of the meniscal root based on MRI in group A was significantly lower than that in group R (p<0.001). The medial meniscal extrusion in groups A and R decreased by 0.2±0.1mm and 0.1±0.3mm following MMRR without significant differences (p=0.056 and p=0.229, respectively). The IMSI presented significant negative correlations with the root healing status and significant positive correlations with K–L grade progression (p<0.05). DiscussionAtelocollagen application during MMRR yielded lower IMSIs, suggesting better healing, than did conventional pullout root repair. However, this technique could not demonstrate beneficial effects on meniscal extrusion. Level of evidenceIII, retrospective case-control study.

Comparison of Clinical and Radiographic Outcomes of Vertical Simple Stitch Versus Modified Mason-Allen Stitch in Arthroscopic Bankart Repairs: A Prospective Randomized Controlled Study

Background: In spite of the probable advantages of Bankart repair with modified Mason-Allen technique, there has been no study to evaluate the clinical outcomes of the modified Mason-Allen technique for Bankart repair. Purpose: To prospectively compare the anatomic and clinical outcomes between the vertical simple stitch and the modified Mason-Allen stitch with respect to the labral height, retear rate, redislocation/apprehension, and various functional outcome scores. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: Patients who underwent arthroscopic Bankart repair with double-loaded suture anchors were randomly allocated to 1 of 2 groups: the vertical simple stitch method (SS; n = 45) or the Bankart repair using modified Mason-Allen technique (BRUMA; n = 41). All patients underwent computed tomography arthrography at 6 months postoperatively and various functional outcome measurements at least 2 years postoperatively. The labral height and width at the 3-, 4-, and 5-o’clock positions were measured preoperatively and at 6 months after surgery on axial computed tomography arthrography; the redislocation/apprehension rate, the retear rate, and various functional outcome scores were evaluated at each follow-up visit. Results: Postoperative labral height and width were significantly increased at all locations (all P < .001) in both groups, but they were not statistically different between groups (all P > .05). Two patients in the SS group (4.4%) and 2 in the BRUMA group (4.9%) experienced redislocation after surgery, and 4 patients in the SS group (8.9%) and 2 in the BRUMA group (4.9%) group showed apprehension after surgery. Additionally, 5 patients in the SS group (11.1%) and 2 in the BRUMA group (4.9%) showed retear at 6 months (P = .239). There were no differences in any functional outcome scores (all P > .05). Conclusion: There was no difference in the radiologic outcomes at 6 months and the clinical outcomes assessed at least 2 years after surgery between the groups.

Minimum 1 year results of pull-out suture repair with modified Mason-Allen stitch in medial meniscus root tear

Minimum 1 year results of pull-out suture repair with modified Mason-Allen stitch in medial meniscus root tear

Surgical Technique for Arthroscopic Lateral Collateral Ligament Repair.

Arthroscopic repair of the lateral collateral ligament (LCL) complex in patients who have posterolateral rotatory instability after an unstable elbow dislocation, with or without an intra-articular fracture, is an alternative treatment for restoring stability of the elbow and obtaining successful clinical and radiographic results. Obtain radiographs and CT and MRI scans to make an accurate analysis of the fracture patterns and develop an understanding of soft-tissue comorbidities. Place the patient in the lateral decubitus position and create proximal anteromedial, proximal anterolateral, anterolateral, and radial head portals as working portals and a posterior soft-spot portal as a viewing portal for the repair of the LCL complex. Identify concomitant radial head and coronoid fractures, and confirm the LCL-complex tear intraoperatively. Treat intra-articular fractures arthroscopically before the LCL-complex repair. After soft-tissue debridement using the soft-spot portal as a viewing portal and the proximal anterolateral portal as a working portal, decorticate the footprint of the humeral attachment of the LCL complex with use of a shaver or burr and then make a modified Mason-Allen stitch using a needle, fixing the suture with a knotless anchor, to achieve a stable elbow joint. After postoperative immobilization of the elbow for 2 to 3 days, instruct the patient to perform passive exercises, returning to a full range of motion at 4 to 6 weeks after surgery, and typically returning to full activity at 3 months after the operation. To date, arthroscopic LCL-complex repair has produced excellent results, with all 13 patients in our original study reporting complete resolution of the elbow instability and demonstrating a negative result on the lateral pivot-shift test15.

Biomechanical evaluation of the simple cinch stitch for arthroscopic rotator cuff repair

BackgroundThe tissue-suture interface is described as the most vulnerable and susceptible area in the muscle–tendon–bone construction of arthroscopic rotator cuff repair. Various stitching techniques have been described to enhance the strength, fixation and stability of the repair, but technical and biomechanical challenges remain.Purpose was to examine the biomechanical properties of the simple cinch stitch in comparison to other stitches commonly used for rotator cuff repair. MethodsInfraspinatus tendons were harvested from sheep and split in half. The tendons were randomized into five different stitch configuration groups for biomechanical testing: simple stitch; horizontal stitch; FiberChain®; simple cinch stitch; and modified Mason-Allen stitch. Each specimen was first cyclically loaded on a universal materials testing machine under force control from 5 to 30N at 0.25Hz for twenty cycles. Then, each specimen was loaded to failure under displacement control at a rate of 1mm/s. Cyclic elongation, peak-to-peak displacement and ultimate tensile load were measured. The type of failure was recorded. FindingsNo differences in cyclic elongation or peak-to-peak displacement were seen between stitch configurations. In the load-to-failure test, the simple cinch stitch demonstrated significantly higher ultimate load than the simple and the horizontal stitch configurations. The comparison to the FiberChain® Suture revealed no statistical significant differences.The FiberChain® Suture demonstrated significantly higher ultimate load than the simple stitch. No statistical significance could be demonstrated in comparison to the horizontal stitch or the simple cinch stitch.The ultimate tensile load of the modified Mason-Allen stitch was significantly higher than that of the other stitch configurations. InterpretationThe simple cinch stitch has an ultimate tensile load comparable to the FiberChain® suture and is superior to the simple stitch and the horizontal stitch. The major advantage of the simple cinch technique is that it is possible to perform the stitch entirely arthroscopically, without the need to perforate the tissue a second time or to use special suture materials. Study designControlled laboratory study.

Tendon Collagen Crosslinking Offers Potential to Improve Suture Pullout in Rotator Cuff Repair: An Ex Vivo Sheep Study.

The suture-tendon interface is often the weakest link in tendon to bone repair of massive rotator cuff tears. Genipin is a low-toxicity collagen crosslinker derived from the gardenia fruit that has been shown to augment collagen tissue strength and mechanically arrest tendon-tear progression. The purpose of the current study was to evaluate whether genipin crosslinking can sufficiently augment the suture-tendon interface to improve suture pullout strength using simple single-loop sutures and the modified Mason-Allen technique. The study also aimed to assess whether time of genipin treatment is a relevant factor in efficacy. In an ex vivo (cadaveric) sheep rotator cuff tendon model, a total of 142 suture pullout tests were performed on 32 infraspinatus tendons. Each tendon was prepared with three single-loop stitches. Two groups were pretreated by incubation in genipin solution for either 4 hours or 24 hours. Two corresponding control groups were incubated in phosphate buffered saline for the same periods. The same test protocol was applied to tendons using modified Mason-Allen technique stitch patterns. Each suture was loaded to failure on a universal materials testing machine. Suture pullout force, stiffness, and work to failure were calculated from force-displacement data, and then compared among the groups. Median single-loop pullout force on tendons incubated for 24 hours in genipin yielded an approximately 30% increase in maximum pullout force for single-loop stitches with a median of 73 N (range, 56-114 N) compared with 56 N (range, 40-69 N; difference of medians = 17 N; p = 0.028), with corresponding increases in the required work to failure but not stiffness. Genipin treatment for 4 hours showed no added benefit for suture-pullout behavior (46 N, [range, 35-95 N] versus 45 N, [range, 28-63 N]; difference of medians, 1 N; p = 1). No tested genipin crosslinking conditions indicated benefit for tendons grasped using the modified Mason-Allen technique after 4 hours (162 N, [range, 143-193 N] versus 140 N, [range, 129-151 N]; difference of medians, 22 N; p = 0.114) or after 24 hours of crosslinking (172 N, [range, 42-183 N] versus 164 N [range, 151-180 N]; difference of medians, 8 N; p = 0.886). Exogenous collagen crosslinking in genipin can markedly improve resistance to pullout at the tendon-suture interface for simple stitch patterns while the modified Mason-Allen stitch showed no benefit in an ex vivo animal model. Tendon strength augmentation by genipin pretreatment offers the potential to improve suture retention properties. Future studies are warranted for the development of clinically viable intraoperative delivery strategies and in vivo testing for safety and efficacy.

Arthroscopic Medial Meniscus Posterior Root Fixation Using a Modified Mason-Allen Stitch

A complete radial tear of the meniscus posterior root, which can effectively cause a state of total meniscectomy via loss of hoop tension, requires that the torn root be repaired. Several methods have been used to repair medial meniscus posterior root tears, most of which are based on a simple stitch technique that is known to have stitch-holding strength. We applied a modified version of the Mason-Allen stitch technique, which is recognized as a method for rotator cuff repair surgery because its locking effect overcomes the potential weakness of simple stitches. This article introduces the medial meniscus posterior root tears repair procedure based on a modified Mason-Allen stitch technique in which 2 strands (i.e., 1 simple horizontal and 1 simple vertical stitch) are used.

Primary stability of rotator cuff repair: can more suture materials yield more strength?

It remains unclear if the increased biomechanical stability of the double-row repair is solely a result of the technique itself or due to the greater number of utilized materials. This study analyses the various rotator cuff (RC) repair interfaces and the influence of doubling the number of suture knots, stitch techniques and suture anchors on the primary stability of the RC reconstruction. Established cyclic testing protocols were used to test the primary stability of the knot interface with a Duncan loop and Roeder knot, the tendon-to-suture interface with a single-stitch and Mason-Allen-stitch and the anchor-to-bone interface with OPUS Magnum 2® and BioCorkscrew® anchors. After doubling the materials, the interfaces were tested again and compared to the yielded solitary values. The maximum failure loads (Fmax), clinical failure (CF), system displacement (SD) and modes of failure were recorded. Doubling the amount of knots, stitches and suture anchors improved almost all interface parameters. For example, Fmax, CF and SD of the Roeder knot could be significantly improved from 142.5N to 256.7N, from 82.5N to 155.0N and from 0.45mm to 0.20mm, respectively. The Mason-Allen stitch's Fmax improved from 196.4N to 324.9N, and CF from 94.25N to 139.8N, with almost identical SD of 0.81mm and 0.84mm. Bio-Corkscrew® Fmax improved from 232.5N to 317.5N, CF from 182.5N to 210N, and SD from 0.85mm to 0.64mm. Doubling the number of knots, stitches and suture anchors increases the primary stability of the various RC repair interfaces and may result in RC rerupture rate reduction. Furthermore, this study suggests that a suture anchor loaded with two or three sutures may yield the same primary stability as two or three suture anchors loaded with a single suture. This in vitro biomechanical study focuses solely on the rotator cuff interfaces at time zero; the biological healing process was therefore not analysed and requires further investigation. Improved primary stability by increased number of suture materials may reduce rate of RC rerupture.

Suture Technique Influences the Biomechanical Integrity of Pectoralis Major Repairs.

Pectoralis major ruptures occur in large, muscular individuals, and repair constructs may experience significant tension. Four different suture techniques were evaluated biomechanically to determine the effect of suture technique on optimizing fixation strength. Forty fresh-frozen cadaveric shoulders were repaired using endosteal buttons. The control group was repaired with #2 polyblend suture in a modified Mason-Allen stitch configuration. The triple group was repaired using the same suture and configuration, but with the addition of triple-loaded buttons. The configuration group was repaired using the same suture in a Krackow/Bunnell configuration. The tape group was repaired using 2-mm polyethylene tape and #5 polyblend suture in the Krackow/Bunnell configuration. Under cyclic loading, there was no significant difference between groups. Under load-to-failure testing, the tape group withstood a significantly greater maximum load (726.0±90.0 N) than the control and triple groups (330.2±20.2 and 400.2±35.2 N, respectively; P<.005), and similar load to the configuration group (509.9±68.6 N; P=.16). The configuration group failed via suture breakage (9/10); the other groups failed via suture pullout, in which suture pulled through tendon (26/30). Pectoralis major repair in a running, locked configuration appears to improve biomechanical performance by preventing suture pullout. Use of a polyethylene tape construct demonstrates the potential for improved failure loads, but its role remains undefined.

Biomechanical evaluation between the modified Mason-Allen stitch and the locked double-tie stitch on the infraspinatus of sheep

ObjectivesTo evaluate and compare the in vitro biomechanical results from two stitches: the Mason-Allen stitch, as modified by Habermeyer; and the locked double-tie stitch developed at our service, on tendons of the infraspinatus muscle of sheep. MethodsTwenty tendons from the infraspinatus muscle of sheep were randomly divided into two groups: LDT, on which the locked double-tie stitch was performed; and MA, with the modified Mason-Allen stitch. The evaluation was performed in the mechanics laboratory, using a standard test machine with unidirectional traction, constant velocity of 20mm per second and a 500N load cell, without force cycling. ResultsWe observed that LDT was superior to MA, for the force needed to form spaces of both 5mm (p=0.01) and 10mm (p=0.002) and also for the maximum traction resistance (p=0.003). ConclusionWe confirmed our hypothesis that LDT stitches are superior to MA stitches from a biomechanical point of view. This is a further stitching option for surgeons, when fragile and poorly vascularized tendons need to be sutured, and it improves the quality of fixation without increasing the “strangulation” and, consequently, the ischemic area.

Biomechanical Comparison of Different Suturing Techniques in Rabbit Medial Gastrocnemius Muscle Laceration Repair

Skeletal muscle laceration is a common injury. Repair of disrupted delicate tissue is still a clinical challenge for surgeons. A few different muscle repair techniques have been reported. However, the best muscle repair technique has not been identified. The aim of the present study is to compare the biomechanical features of different repair techniques in muscles to identify the most effective one. New Zealand white rabbits (2.5-3 kg) were euthanized and medial gastrocnemius muscles were isolated. The muscles were completely transected with scalpels and then repaired by 3 different techniques, namely, (1) 2-strand mattress, (2) 4-strand Kessler (with epitendinous suture), and (3) Mason-Allen. To measure suture performance, the repaired specimens were mounted onto a mechanical testing machine Instron 5543. The muscles were loaded to failure at a constant speed of 60 mm/min. Data collected from Merlin v5.31 software were used to compute the biomechanical properties of each specimen. There was no significant difference in the mean maximum load of Kessler group (15.5 N) and Mason-Allen group (13.2 N), whereas the mean maximum load of the control (Mattress) group (4.4 N) was significantly smaller than the other 2 groups. Moreover, Kessler stitches were the stiffest among the 3. It is noteworthy that the mechanisms of failure were different: Kessler stitches were all pulled out longitudinally, whereas Mason-Allen stitches transmitted load across the laceration and ruptures occur at areas adjacent to the stitches, indicating that muscle is the weakest element in the biomechanical testing. Both Kessler and Mason-Allen stitches have shown better biomechanical features compared with the control group. Further study has to be done to compare the effect of these 2 techniques on muscle regeneration and scar formation in an in vivo model.

Clinical and Radiologic Evaluation of Arthroscopic Medial Meniscus Root Tear Refixation: Comparison of the Modified Mason-Allen Stitch and Simple Stitches

This study compared the clinical and radiologic outcomes of arthroscopic medial meniscus root refixation using the modified Mason-Allen stitch and simple stitches. The outcomes of 25 patients who underwent arthroscopic meniscus root refixation using the modified Mason-Allen stitch (M group) between June 2010 and January 2012 were compared with those of 25 matched control patients (S group) who underwent meniscus root refixation using simple stitches between March 2004 and August 2007. The Lysholm score, International Knee Documentation Committee Subjective Knee Form score, joint space narrowing, and Kellgren-Lawrence grade were assessed. Medial meniscal extrusion, progression of cartilage degeneration, and healing status of the refixed medial meniscus root were assessed on magnetic resonance images. No between-group difference was found in age, sex, body mass index, or preoperative patient characteristics. The mean follow-up times for the M and S groups were 24.1 and 25.9 months (P = .248), respectively. The Lysholm, International Knee Documentation Committee Subjective Knee Form, and Tegner activity scores improved significantly in both groups. The repaired root tended to heal better in the M group than in the S group (P = .065). Although the postoperative clinical outcomes did not differ between the groups, postoperative medial meniscal extrusion decreased -0.6 ± 0.9 mm in the M group and increased 1 ± 0.6 mm in the S group on magnetic resonance imaging (P < .001). The M group did not show significant progression in the Kellgren-Lawrence grade and cartilage degeneration (P = .083 and P = .317, respectively), whereas both measures increased significantly in the S group (P = .008 and P < .001, respectively). Compared with simple stitches, the modified Mason-Allen stitch improved the degree of meniscal extrusion, although the 2 different suture techniques showed no difference in clinical outcomes at short-term follow-up. Level III, retrospective comparative study.