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Xu SW, Mao WF, Wu YF. Gap Resistance and Tensile Strength of a Q Suture Technique During Curved Loading: An Ex Vivo Porcine Flexor Tendon Study. J Hand Surg Am 2023:S0363-5023(23)00552-X. [PMID: 37978961 DOI: 10.1016/j.jhsa.2023.10.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 09/29/2023] [Accepted: 10/11/2023] [Indexed: 11/19/2023]
Abstract
PURPOSE This study aimed to determine the mechanical properties of the double Q suture technique in angular motion and to compare the gap formation associated with tendon repairs during curved and linear loading. METHODS Eighty porcine flexor tendons were repaired with one of two 4-strand sutures: double Q suture or double modified Kessler plus peripheral running sutures. The repaired tendons were cyclically loaded sequentially against a pulley with a radius of 2.0, 1.5, and 1.0 cm or linearly without any pulleys. The number of tendons that formed an initial or 2-mm gap at the repair site during cyclic loading, the gap size between tendon ends when cyclic loading ended, and the ultimate strength were recorded. RESULTS The gap at the repair site formed gradually from the dorsal to volar aspect during curved loading. No double Q repairs, but half of the double Kessler plus running suture repairs, formed an initial or 2-mm gap on the volar aspect during curved loading. The double Q group had a significantly smaller gap size on the dorsal aspect than the double Kessler plus running suture group at all three radii of curvature. The ultimate strength was similar between the two groups. There were no significant differences in linear motion between these two repairs. CONCLUSIONS The double Q suture is superior to the conventional 4-strand tendon core suture plus running peripheral sutures in gap resistance in angular motion. This study provides insight into the formation of an unbalanced gap on the dorsal and volar aspects of tendon repair during curved loading. CLINICAL RELEVANCE The double Q suture provides a simple and efficient option for flexor tendon repair considering the high risk of gap formation on the dorsal aspects of the tendon repair in angular motion.
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Affiliation(s)
- Si Wei Xu
- Department of Hand Surgery, Affiliated Hospital of Nantong University, Nantong, Jiangsu, China; Medical School, Nantong University, Nantong, Jiangsu, China
| | - Wei Feng Mao
- Department of Hand Surgery, Affiliated Hospital of Nantong University, Nantong, Jiangsu, China
| | - Ya Fang Wu
- Department of Hand Surgery, Affiliated Hospital of Nantong University, Nantong, Jiangsu, China.
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Xu SW, Wu YF. Effect of loading speed on gap resistance and tensile strength of flexor tendon repair under cyclic loading test. J Biomech 2023; 158:111749. [PMID: 37562275 DOI: 10.1016/j.jbiomech.2023.111749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 05/08/2023] [Accepted: 07/31/2023] [Indexed: 08/12/2023]
Abstract
Postoperative digit motion is important for the functional recovery of injured tendons. To date, it is unknown whether the loading speed impacts the biomechanical properties of a repaired tendon. This study investigated the effect of loading speed on the gap resistance and tensile strength of tendon repairs. One hundred porcine flexor tendons were repaired with two core sutures, 4-strand modified Kessler and double Q, and cyclically loaded at the speeds of 10, 40, 80, 160, and 320 mm/min. The number of tendons that formed an initial or 2 mm gap at the repair site during cyclic loading, stiffness at the 1st and 20th loading cycles, gap size between tendon ends when cyclic loading ended, and the ultimate strength were recorded. Under the lowest loading speed, the tendons repaired with the 4-strand modified Kessler suture developed significantly larger gaps and smaller stiffness than those with a greater loading speed. The loading speed did not affect the maximum strength of both tendon repairs. The findings suggest that very slow motion promotes gap formation of tendon repair with inferior gap resistance. The rate corresponds to regular hand action or the tendon core suture possessing a strong gap resistance increases the safety margin during early active finger movement. Our findings help to guide the exercise regimens after tendon surgery.
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Affiliation(s)
- Si Wei Xu
- Department of Hand Surgery, Affiliated Hospital of Nantong University, Nantong, Jiangsu, China; Medical School, Nantong University, Nantong, Jiangsu, China
| | - Ya Fang Wu
- Department of Hand Surgery, Affiliated Hospital of Nantong University, Nantong, Jiangsu, China.
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Stirling PHC, McEachan JE. In vitro testing of flexor tendon repair models: variability in the current literature. J Hand Surg Eur Vol 2023; 48:162-168. [PMID: 36428224 DOI: 10.1177/17531934221139068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Vissers G, Rusli WMR, Scarborough A, Horwitz MD, McArthur GJ, Kedgley AE. A study to compare strengths of cadaveric tendon repairs with round-bodied and cutting needles. J Hand Surg Eur Vol 2022; 47:481-485. [PMID: 34878950 DOI: 10.1177/17531934211064201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
This human cadaver study investigated whether flexor tendon repairs performed with round-bodied needles had a higher risk of pull-out compared with those performed with cutting needles. Forty human cadaver tendons were repaired (20 with each type of needle), subjected to tensile traction testing and evaluated by failure load and mode of failure. The average failure load was 50 N (SD 13 N) for tendons repaired with round-bodied needles, compared with 49 N (SD 16 N) for tendons repaired with cutting needles. Round-bodied needles resulted in more suture pull-out (18 out of 20 tendons) than cutting needles (6 out of 20 tendons). We found no differences in failure load, but significant differences in the mode of failure between round-bodied and cutting needles when used for cadaveric flexor tendon repair.
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Affiliation(s)
- Gino Vissers
- Department of Plastic Surgery, Chelsea and Westminster Hospital NHS Foundation Trust, London, UK
| | - Wan M R Rusli
- Department of Bioengineering, Imperial College London, London, UK
| | - Alexander Scarborough
- Department of Plastic Surgery, Chelsea and Westminster Hospital NHS Foundation Trust, London, UK
| | - Maxim D Horwitz
- Department of Plastic Surgery, Chelsea and Westminster Hospital NHS Foundation Trust, London, UK
| | - Gordon J McArthur
- Department of Plastic Surgery, Chelsea and Westminster Hospital NHS Foundation Trust, London, UK
| | - Angela E Kedgley
- Department of Bioengineering, Imperial College London, London, UK
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Renfree KJ, Dahiya N, Kransdorf MJ, Zhang N, Patel KA, Drace PA. Comparative Accuracy of 1.5T MRI, 3T MRI, and Static Ultrasound in Diagnosis of Small Gaps in Repaired Flexor Tendons: A Cadaveric Study. J Hand Surg Am 2021; 46:287-294. [PMID: 33451904 DOI: 10.1016/j.jhsa.2020.10.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 07/07/2020] [Accepted: 10/26/2020] [Indexed: 02/02/2023]
Abstract
PURPOSE We hypothesized that magnetic resonance imaging (MRI) would more accurately diagnose small gaps (<6 mm) after flexor tendon repair than static ultrasound (US) and that suture artifact would negatively impair accuracy. METHODS A laceration of the flexor digitorum profundus was created in 160 fresh-frozen cadaveric digits and randomized to either an intact repair (0-mm gap) or repairs using a locked 4-strand suture repair with either 4-0 Prolene, Ethibond, or and gaps of 2, 4,or 6 mm; or no suture in which 2-, 4-, or 6-mm gaps were created without a suture crossing the repair site. We performed 1.5T and 3T MRI and static US studies; gap widths were estimated by radiologists blinded to suture presence and true gap widths. RESULTS The 1.5 and 3.0T MRI had a lower mean error than US for gap sizes 0 and 2 mm. All 3 modalities performed similarly for 4- and 6-mm gaps. Documentation of imaging artifact worsened error, and odds of seeing artifacts were 1.72 higher with MRI than with US. Suture did not worsen artifact nor impair accuracy for any of the 3 modalities. When no suture was used, all 3 modalities significantly overestimated the true gap. CONCLUSIONS MRI is most accurate for small gaps less than 4 mm. Although all modalities overestimated gap sizes in specimens with a 0-mm gap (intact tendon repair), mean overestimation (<2 mm) was not clinically relevant. Ultrasound overestimated 2-mm gaps (clinically intact repairs), whereas MRIs did not. We recommend MRI for evaluation of gaps after flexor tendon repair. The 1.5T has slightly better sensitivity and specificity for distinguishing clinically intact (gap < 3 mm) from clinically impaired (gap > 3 mm) repairs than the 3T. CLINICAL RELEVANCE Accurate diagnosis of intact repairs or small gaps (<3 mm) might prevent unnecessary exploration or allow modification of rehabilitation protocols. Diagnosis of clinically relevant gaps (3-6 mm) may allow for earlier revision surgery before significant tendon retraction and adhesions develop, possibly necessitating a staged reconstruction.
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Affiliation(s)
- Kevin J Renfree
- Department of Orthopaedic Surgery, Mayo Clinic Arizona, Phoenix, AZ.
| | | | | | - Nan Zhang
- Department of Biostatistics, Mayo Clinic Arizona, Phoenix, AZ
| | - Karan A Patel
- Department of Orthopaedic Surgery, Mayo Clinic Arizona, Phoenix, AZ
| | - Patricia A Drace
- Department of Orthopaedic Surgery, Phoenix Children's Hospital, Phoenix, AZ
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Comparative Sensitivity and Specificity of Static and Dynamic High-Resolution Ultrasound in Diagnosis of Small Gaps in Repaired Flexor Tendons: A Cadaveric Study. J Hand Surg Am 2021; 46:247.e1-247.e7. [PMID: 33277100 DOI: 10.1016/j.jhsa.2020.10.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 07/31/2020] [Accepted: 10/13/2020] [Indexed: 02/02/2023]
Abstract
PURPOSE To compare the sensitivity and specificity of high-resolution static and dynamic ultrasound (US) for diagnosing intact repairs and small, clinically relevant gaps (≥4 mm) in repaired flexor digitorum profundus tendons within zone 2 and, secondarily, to evaluate the effect of suture artifact from 3 commonly used suture types. METHODS Eighty-eight fresh-frozen cadaveric digits (thumbs excluded) were randomized to either an intact repair (0-mm gap) or repairs using a locked 4-strand suture repair with either 4-0 Prolene, Ethibond, or FiberWire and gaps of 2, 4, or 6 mm and no suture in which 2-, 4-, or 6-mm gaps were created without a suture crossing the repair site. Gap widths were estimated by a blinded musculoskeletal ultrasonographer in static and dynamic modes. RESULTS Both static and dynamic modalities tended to overestimate actual gap sizes. For the suture gaps, both modalities had poor sensitivity (29% static; 42% dynamic) for accurately diagnosing a clinically intact repair (<4 mm), but better specificity (83% static; 75% dynamic) for diagnosing a clinically failed repair (≥4-mm gap). Although suture presence decreased the sensitivity of gap width measurement for both modalities, no differences were seen between suture types. CONCLUSIONS Static and dynamic US have poor sensitivity for diagnosing clinically intact repairs (gaps < 4 mm) because they typically overestimate gap size. The ability to diagnose failed repairs (gap ≥ 4 mm), based on greater specificity, is much better, but still suboptimal. CLINICAL RELEVANCE Based on a receiver operating characteristic analysis cutoff of 5 mm, if a gap of 5 mm or larger is identified with US when evaluating a zone 2 flexor digitorum profundus tendon repair, a failed repair is likely in about 80% of cases. A gap measurement of less than 5 mm may miss a high percentage of repairs that are clinically failed.
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Johnson SP, Kelley BP, Waljee JF, Chung KC. Effect of Time to Hand Therapy following Zone II Flexor Tendon Repair. PLASTIC AND RECONSTRUCTIVE SURGERY-GLOBAL OPEN 2020; 8:e3278. [PMID: 33425592 PMCID: PMC7787324 DOI: 10.1097/gox.0000000000003278] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 10/08/2020] [Indexed: 12/04/2022]
Abstract
This population-based study aimed to define how time to hand therapy following isolated zone II flexor tendon repairs impacts complications and secondary procedures. METHODS Insurance claims from the Truven MarketScan Databases were used to evaluate outcomes after isolated zone II flexor tendon repairs between January 2009 and October 2015. Cohorts differing in time to hand therapy were compared to evaluate the impact on complications, reoperation, and number of therapy sessions. Secondary outcomes analyzed how the number of therapy sessions affected rates of reoperation. RESULTS Hand therapy was identified in 82% of patients (N = 2867) following tendon reconstruction. Therapy initiation occurred within 1 week, 1-4 weeks, and after 4 weeks in 56%, 35%, and 9% of patients, respectively. Univariate analysis showed no difference in non-tendinous complications (27%, 30%, 29%; P = 0.29) or tendon rupture rates (13%, 13%, 10%; P = 0.42) within 90 days between cohorts. Multivariable analysis showed no difference in rates of tenolysis (6.3%, 6%, 4.4%; P > 0.01). In the early initiation cohort, >23 hand therapy sessions were associated with the highest rates of tenolysis (19%). CONCLUSIONS Despite being a common fear of hand surgeons, early initiation of hand therapy was not associated with increased tendon rupture rates. Although delayed therapy is a concern for tendon scarring, it did not confer a higher risk of tenolysis. Complication rates do not appear to correlate with timing of hand therapy. Therefore, hand surgeons should promote early mobility following isolated flexor tendon injuries given the known functional outcome benefits.
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Affiliation(s)
- Shepard P Johnson
- Department of Surgery, Section of Plastic Surgery, University of Michigan Medical School, Ann Arbor, Mich
| | - Brian P Kelley
- Institute of Reconstructive Plastic Surgery, Ascension Seton Healthcare and Department of Surgery and Perioperative Care, Dell Medical School, Austin, Tex
| | - Jennifer F Waljee
- Department of Surgery, Section of Plastic Surgery, University of Michigan Medical School, Ann Arbor, Mich
| | - Kevin C Chung
- Department of Surgery, Section of Plastic Surgery, University of Michigan Medical School, Ann Arbor, Mich
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Mao WF, Wu YF. Effects of a Q Suture Technique on Resistance to Gap Formation and Tensile Strength of Repaired Tendons: An Ex Vivo Mechanical Study. J Hand Surg Am 2020; 45:258.e1-258.e7. [PMID: 31451319 DOI: 10.1016/j.jhsa.2019.06.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 04/04/2019] [Accepted: 06/11/2019] [Indexed: 02/02/2023]
Abstract
PURPOSE The repair of digital flexor tendons following laceration should aim to prevent gapping at the repair site and restore the tensile strength of the tendons to facilitate postoperative movement. We present here a simple Q suture and test its effects on gap formation and tensile strength of the repaired tendons. METHODS Sixty porcine tendons were repaired with 3 2-strand sutures (Kessler, Kessler plus 2Q, and Kessler plus running sutures) and 3 4-strand sutures (double Kessler, double Kessler plus 2Q, and double Kessler plus running sutures). The specimens were subjected to a cyclic loading. At each cycle, the number of tendons that initiated gapping or formed a 2-mm gap at the repair site was determined. After the cyclic load testing, the gap distance between tendon ends and the ultimate strength of the repaired tendons was measured. RESULTS In both 2-strand and 4-strand tendon repairs, augmentation by insertion of the 2Q sutures reduced the number of tendons that showed 2-mm gaps ends during loading. Compared with the single Kessler and Kessler plus running sutures, Kessler plus 2Q suture significantly increased the ultimate strength of the tendon repair. Compared with the double Kessler and double Kessler plus running sutures, double Kessler plus 2Q suture significantly decreased the gap distance at the repair site after cyclic loading. CONCLUSIONS The Q suture technique effectively enhances the resistance to gap formation of 2-strand and 4-stand tendon repair. It also improves the tensile strength of 2-strand Kessler repairs. CLINICAL RELEVANCE The Q suture is a simple technique that can resist gap formation and strengthen the tensile strength of the repaired tendons in the laboratory setting.
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Affiliation(s)
- Wei Feng Mao
- Hand Surgery Research Center, Affiliated Hospital of Nantong University, Nantong, Jiangsu, China
| | - Ya Fang Wu
- Hand Surgery Research Center, Affiliated Hospital of Nantong University, Nantong, Jiangsu, China.
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Linnanmäki L, Göransson H, Havulinna J, Karjalainen T, Leppänen OV. Factors Accounting for Variation in the Biomechanical Properties of Flexor Tendon Repairs. J Hand Surg Am 2018; 43:1073-1080.e2. [PMID: 30292714 DOI: 10.1016/j.jhsa.2018.08.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 06/26/2018] [Accepted: 08/20/2018] [Indexed: 02/02/2023]
Abstract
PURPOSE To investigate factors that cause variation in the mechanical properties of flexor tendon repairs. METHODS One surgeon repaired 50 homogeneous absorbent sticks and 40 porcine flexor tendons with a simple loop, an Adelaide repair, a peripheral over-and-over repair, or a combination of the latter 2 repairs. Ten hand surgeons repaired 1 porcine flexor tendon with the combined Adelaide core and over-and-over peripheral repair. We loaded the samples statically until failure and calculated the variations caused by the testing process, tendon substance, and surgical performance in terms of yield and ultimate load. RESULTS Tendon material and surgical performance both caused about half of the variation in the yield load of the combined repair. Surgical performance caused all variations observed in the ultimate load of the combined, peripheral-only, and core repairs. The effect of the tendon material was negligible in ultimate load. The intersurgeon variation was present only in yield load, and it represented one-tenth of the total variation. CONCLUSIONS The effect of tendon substance on variation of the ultimate load is minimal. In yield load, both tendon and surgical performance are responsible for the variation. CLINICAL RELEVANCE In clinical realm, variation caused by testing is not present, but intersurgeon variation may cause additional variation in yield load. A hand surgeon cannot change the variation due to tendon properties, but with a more meticulous surgical technique, the variation related to the surgical performance can probably be diminished.
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Affiliation(s)
- Lasse Linnanmäki
- Department of Hand and Microsurgery, University of Tampere, Faculty of Medicine and Life Sciences and Tampere University Hospital, Tampere, Finland
| | - Harry Göransson
- Department of Hand and Microsurgery, University of Tampere, Faculty of Medicine and Life Sciences and Tampere University Hospital, Tampere, Finland
| | | | - Teemu Karjalainen
- Department of Surgery, Central Finland Central Hospital, Jyväskylä, Finland
| | - Olli V Leppänen
- Department of Hand and Microsurgery, University of Tampere, Faculty of Medicine and Life Sciences and Tampere University Hospital, Tampere, Finland.
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