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SILICONE UNDERLAYS AND PULLEYS–VALUABLE ADJUNCT FOR TENDON SURGERY
SILICONE UNDERLAYS AND PULLEYS VALUABLE ADJUNCT FOR TENDON SURGERY Kart Bader,
MD
As in most areas of surgery, hand reconstruction has progressed vigorously due to numerous recent advancements. However, in considering specific tendon repair, the problem of postoperative adhesion is still ever present and often limiting in clinical result. In an effort to gain a more precise understanding of tendon healing, and thus improve postoperative function, the physiology of tendon reparative processes have been studied by numerous investigati0ns.l" Currently, the tendon, per se, has been demonstrated to have little influence in its immediate repair ; the primary restitution of the tendon continuity occurs almost solely from the surrounding tissue, ie the sheaths around the injured tendon and particularly the paratenon which is claimed to be the main source of new connective tissue affected in the regeneration.6-* Consolidating the prior anatomical data, endeavors to prevent postoperative adhesion were made by separating the healing tendon from the surrounding connective tissue. Used were a variety of substances, including metallic and synthetic fabrications, polyethylene tubes, autogenous fat and fascia grafts, Karl Bader, MD, is clinical associate professor of Surgery, University of Illinois College of Medicine, Chicago. He is also attending surgeon, Rockford Memorial Hospital, Illinois.
June 1970
and even homo graft^?-^^ Recent attempts to achieve a well-functioning tendon anastomosis involve systemic usage of antimetabolytes and the fashioning of artificial tendon sheaths from monomolecular cellulose filter tubes.15-ls Despite the ingenious methods of many of these presentations, none have proved generally satisfactory or have met with wide acceptance. Because of the relatively inert but reliable and durable qualities of solid, implantable silicone ( dimethyl siloxane) tendon accessories were designed to improve postsurgical functioning. After extensive testing, a form of silicone pulley was devised to aid tendon placement and balance; also, subtendon inlays were fashioned for employment under areas of tendon repair or exploration, to eliminate adhesions and later anchorage.l7-l8 After extensive canine experimentation and subsequent modification for human applicability, three sizes of tendon pulleys were established, ranging from 1.5 to 2.5 cm lengths. Each pulley is made from re-enforced dimethyl siloxane sheeting and has polyester netting exposed at the ends (Fig 1). I t was observed that fibroblasts would infiltrate the mesh endplates within two to three weeks and fix the prosthesis in place with periosteal attachment, yet leaving the
57
central portion (over the tendon) inert and unreactive.l8 The tendon underlays are fabricated in five lengths up to 4 cm, and mesh is bonded to the under surface (Fig 2 ) . This implant is designed to be positioned with the nonreactive side up, opposite the explored or damaged tendon. The mesh underside is placed inferiorally against adjacent tissues, for rapid fixation. The author has used the combination of silicone underlays and/or pulleys in a total of 36 cases over the past 40 months. Each patient represented a definite problem in tendon reconstruction - usually anticipated adhesion and defunctionalization of the tendon repair. There were 13 cases of primary tendon reconstructions in “NO Man’s Land” and approximately one-half of the total number were referrals for secondary procedures after initial failure.
A summary of the 36 consecutive patients is as follows: -~_
___
__
Results of Dimethyl Siloxane Underlays and Pulleys in Patients PROCEDURE
Exploration-primary tenolysis Primary suture Secondary suture Primary tendon graft Secondary tendan graft Re-exploration-tenolysis and suture Tendon transfers TOTALS
NUMBEROF GOOD POOR PATIENTS RESULTS RESULTS
8 12 6 1 3
8 10 5 1 2
0 2 1 0 1
5 1 36
4 1
1 0
31
5
This material is presented as a new concept in operative technique for tendon surgery. Silicone underlays and pulleys for tendon reconstruction offer increased latitudes to the current ,methods; through laboratory experimentation and three years of clinical trials of difficult cases with accurate follow-up, the application of readily available tendon accessories has proved reliable and successful. Specifically, the siloxane pulleys were more quickly positioned and their results were more reliable than previous experiences with auto-
58
Fig 1 Silicone pulley with representation demonstrating placement o f polyester mesh in the end plates of the fabrication; lower drawing shows a common positioning of the unit over a flexor tendon graft.
genous fascia or connective tissue. Also, the fact that the prosthetic pulley actually kept the underlying tendon relatively free of adhesions must be interpreted as a major advantage over any other methods presently known. The superior surfaces of the silicone underlays were noted to remain relatively clear of fibrous tissue and, consequently, kept the overlying tendon comparatively free of adhesions during the necessary recuperative period following tendon repair. No infections or extrusions were encountered. Clinically, correct application of the underlays and pulleys broadens operating room consideration and capabilities for tendon trauma. For example, now we have found
Fig 2 Silicone underlay showing placement o f the dacron mesh under the silicone sheet; also, positioning of the total underlay unit under u primary extensor tendon anastomosis.
AORN Journal
Preparation o f six months duration displaying a nearly adhesion-free canine tendon; the pulley is at left o f field and the pulley m a y be noted above superior margin of extensor tendon.
tenolysis to have good, reproducible, longterm results. Primary tendon repair in “NO Man’s Land” and in the carpal canal generally give good function if severe contamination or
other overt complicating features are not present. Also, secondary tendon suture and silicone underlay usually give results far superior to complete graft replacement. In conclusion, the application of these elements in tendon surgery offers better clinical results in current techniques and broadens reconstructive avenues for all tendon trauma. Silicone pulleys and underlays were utilized in 36 complicated tendon reconstructions such as tenolysis, primary repairs, and secondary revisions or grafts. In the consecutive cases (ranging up to 40 months follow-up), good results were attained in 31 patients. This new concept for application of these standard tendon accessories would appear to enlarge the current scope of tendon surgery and should be added to operating room armamentarium for tendon reconstruction.
REFERENCES 1. Garlock, J.H.: “The Repair Processes in Wounds of Tendons and in Tendon Grafts, Ann Surg, 85:92103, 1927. 2. Seggel, R. : “Histologische untersuchunge iiber die Heilung von Schnenwunden und Schnendefkten,” Beitr, KEin, Chir., 37:342-418, 1903. 3. Mason, M.L. and Allen, H.S.: “Process of Tendon Repair: Experimental Study of Tendon Suture and Tendon Graft,” Arch Surg, 25: 615-692, 1932. 4. Mason, M.L. and Allen, H.S.: “The Rate of Healing Tendons: An Experimental Study of Tensile Strength,” Ann Surg, 113:424469, 1941. 5. Adams, W.: On the Reparative Process in Human Tendons: Also a Series of Experiments on Rabbits, J. Churchill, Ltd., London, 1860. 6. Hueck, H. : “uber Schnenregeneration innerhalb echter Schnenscheiden,” Arch Klin Chir, 127 :137-164, 1923. 7. Narvi, E.J.: “Regeneration of Tendons and Treatment of Ruptures of Tendons, Especially in Region of Synovial Sheaths,” Acta chir Scandinav, 60:l54, 1926. 8. Skoog, T. and Persson, B.H.: “An Experimental Study of the Early Healing of Tendons,” Plast & Reconstruc Surg, 13 :384399, 1954. 9. McKee, G.K.: “Metal Anastomosis Tubes in Tendon Suture,” Lancet, 1 :659-666, 1945. 10. Pearlman, R.C.: “The Use of Tantalum in Tendon Reconstruction of the Hand,” US Naval Med Bull, 46:1647-1650, 1946.
June 1970
11. Wheeldon, T.: “The Use of Cellophane as a Permanent Tendon Sheath,” J Bone & Joint Surg, 21 :393-396, 1939. 12. Farmer, A.W.: “Experiences in the Use of Cellophane as an Aid in Tendon Surgery, ” Plast & Reconstruc Surg, 2:207-213, 1947. 13. Gonzales, R.I. : “Experimental Tendon Repair Within the Flexor Tunnels: Use of Polyethylene Tubes for Improvement of Functional Results in the Dog,” Surgery, 26:181-198, 1949. 14. Weckesser, E.C., et al: “A Comparative Study of Various Substances for the Prevention of Adhesions About the Tendons,” Surgery, 25:361-369, 1949. 15. Ashley, F.L. et al: “Experimental and Clinical Studies on the Application of Monomolecular Cellulose Filter Tubes to Create Artificial Tendon Sheaths in Digits,” Plast & Reconstruc Surgery, 23:526-534, 1959. 16. Ashley, F.L. et al: “Further Studies on the Application of Monomolecular, Cellulose Filter Tubes to Create Artificial Tendon Sheaths in the Hand and Wrist,” Pest J Surg, Obst and Gynec, 68:156-161, 1960. 17. Bader, K.F. et al: “Silastic Underlays in Tendon Surgery,” Proc Inst Med of Chicago, 26:21, 1967. 18. Bader, K.F. et al: “Silicone Pulleys and Underlays in Tendon Surgery,” Plast & Reconst Surg, 41 :157-164, 1968. 19. Bader, K.F. et al: “A Successful Silicone Tendon Prosthesis,” AMA Arch Surg, 97:4Q6-411, 1968.
59
MD
As in most areas of surgery, hand reconstruction has progressed vigorously due to numerous recent advancements. However, in considering specific tendon repair, the problem of postoperative adhesion is still ever present and often limiting in clinical result. In an effort to gain a more precise understanding of tendon healing, and thus improve postoperative function, the physiology of tendon reparative processes have been studied by numerous investigati0ns.l" Currently, the tendon, per se, has been demonstrated to have little influence in its immediate repair ; the primary restitution of the tendon continuity occurs almost solely from the surrounding tissue, ie the sheaths around the injured tendon and particularly the paratenon which is claimed to be the main source of new connective tissue affected in the regeneration.6-* Consolidating the prior anatomical data, endeavors to prevent postoperative adhesion were made by separating the healing tendon from the surrounding connective tissue. Used were a variety of substances, including metallic and synthetic fabrications, polyethylene tubes, autogenous fat and fascia grafts, Karl Bader, MD, is clinical associate professor of Surgery, University of Illinois College of Medicine, Chicago. He is also attending surgeon, Rockford Memorial Hospital, Illinois.
June 1970
and even homo graft^?-^^ Recent attempts to achieve a well-functioning tendon anastomosis involve systemic usage of antimetabolytes and the fashioning of artificial tendon sheaths from monomolecular cellulose filter tubes.15-ls Despite the ingenious methods of many of these presentations, none have proved generally satisfactory or have met with wide acceptance. Because of the relatively inert but reliable and durable qualities of solid, implantable silicone ( dimethyl siloxane) tendon accessories were designed to improve postsurgical functioning. After extensive testing, a form of silicone pulley was devised to aid tendon placement and balance; also, subtendon inlays were fashioned for employment under areas of tendon repair or exploration, to eliminate adhesions and later anchorage.l7-l8 After extensive canine experimentation and subsequent modification for human applicability, three sizes of tendon pulleys were established, ranging from 1.5 to 2.5 cm lengths. Each pulley is made from re-enforced dimethyl siloxane sheeting and has polyester netting exposed at the ends (Fig 1). I t was observed that fibroblasts would infiltrate the mesh endplates within two to three weeks and fix the prosthesis in place with periosteal attachment, yet leaving the
57
central portion (over the tendon) inert and unreactive.l8 The tendon underlays are fabricated in five lengths up to 4 cm, and mesh is bonded to the under surface (Fig 2 ) . This implant is designed to be positioned with the nonreactive side up, opposite the explored or damaged tendon. The mesh underside is placed inferiorally against adjacent tissues, for rapid fixation. The author has used the combination of silicone underlays and/or pulleys in a total of 36 cases over the past 40 months. Each patient represented a definite problem in tendon reconstruction - usually anticipated adhesion and defunctionalization of the tendon repair. There were 13 cases of primary tendon reconstructions in “NO Man’s Land” and approximately one-half of the total number were referrals for secondary procedures after initial failure.
A summary of the 36 consecutive patients is as follows: -~_
___
__
Results of Dimethyl Siloxane Underlays and Pulleys in Patients PROCEDURE
Exploration-primary tenolysis Primary suture Secondary suture Primary tendon graft Secondary tendan graft Re-exploration-tenolysis and suture Tendon transfers TOTALS
NUMBEROF GOOD POOR PATIENTS RESULTS RESULTS
8 12 6 1 3
8 10 5 1 2
0 2 1 0 1
5 1 36
4 1
1 0
31
5
This material is presented as a new concept in operative technique for tendon surgery. Silicone underlays and pulleys for tendon reconstruction offer increased latitudes to the current ,methods; through laboratory experimentation and three years of clinical trials of difficult cases with accurate follow-up, the application of readily available tendon accessories has proved reliable and successful. Specifically, the siloxane pulleys were more quickly positioned and their results were more reliable than previous experiences with auto-
58
Fig 1 Silicone pulley with representation demonstrating placement o f polyester mesh in the end plates of the fabrication; lower drawing shows a common positioning of the unit over a flexor tendon graft.
genous fascia or connective tissue. Also, the fact that the prosthetic pulley actually kept the underlying tendon relatively free of adhesions must be interpreted as a major advantage over any other methods presently known. The superior surfaces of the silicone underlays were noted to remain relatively clear of fibrous tissue and, consequently, kept the overlying tendon comparatively free of adhesions during the necessary recuperative period following tendon repair. No infections or extrusions were encountered. Clinically, correct application of the underlays and pulleys broadens operating room consideration and capabilities for tendon trauma. For example, now we have found
Fig 2 Silicone underlay showing placement o f the dacron mesh under the silicone sheet; also, positioning of the total underlay unit under u primary extensor tendon anastomosis.
AORN Journal
Preparation o f six months duration displaying a nearly adhesion-free canine tendon; the pulley is at left o f field and the pulley m a y be noted above superior margin of extensor tendon.
tenolysis to have good, reproducible, longterm results. Primary tendon repair in “NO Man’s Land” and in the carpal canal generally give good function if severe contamination or
other overt complicating features are not present. Also, secondary tendon suture and silicone underlay usually give results far superior to complete graft replacement. In conclusion, the application of these elements in tendon surgery offers better clinical results in current techniques and broadens reconstructive avenues for all tendon trauma. Silicone pulleys and underlays were utilized in 36 complicated tendon reconstructions such as tenolysis, primary repairs, and secondary revisions or grafts. In the consecutive cases (ranging up to 40 months follow-up), good results were attained in 31 patients. This new concept for application of these standard tendon accessories would appear to enlarge the current scope of tendon surgery and should be added to operating room armamentarium for tendon reconstruction.
REFERENCES 1. Garlock, J.H.: “The Repair Processes in Wounds of Tendons and in Tendon Grafts, Ann Surg, 85:92103, 1927. 2. Seggel, R. : “Histologische untersuchunge iiber die Heilung von Schnenwunden und Schnendefkten,” Beitr, KEin, Chir., 37:342-418, 1903. 3. Mason, M.L. and Allen, H.S.: “Process of Tendon Repair: Experimental Study of Tendon Suture and Tendon Graft,” Arch Surg, 25: 615-692, 1932. 4. Mason, M.L. and Allen, H.S.: “The Rate of Healing Tendons: An Experimental Study of Tensile Strength,” Ann Surg, 113:424469, 1941. 5. Adams, W.: On the Reparative Process in Human Tendons: Also a Series of Experiments on Rabbits, J. Churchill, Ltd., London, 1860. 6. Hueck, H. : “uber Schnenregeneration innerhalb echter Schnenscheiden,” Arch Klin Chir, 127 :137-164, 1923. 7. Narvi, E.J.: “Regeneration of Tendons and Treatment of Ruptures of Tendons, Especially in Region of Synovial Sheaths,” Acta chir Scandinav, 60:l54, 1926. 8. Skoog, T. and Persson, B.H.: “An Experimental Study of the Early Healing of Tendons,” Plast & Reconstruc Surg, 13 :384399, 1954. 9. McKee, G.K.: “Metal Anastomosis Tubes in Tendon Suture,” Lancet, 1 :659-666, 1945. 10. Pearlman, R.C.: “The Use of Tantalum in Tendon Reconstruction of the Hand,” US Naval Med Bull, 46:1647-1650, 1946.
June 1970
11. Wheeldon, T.: “The Use of Cellophane as a Permanent Tendon Sheath,” J Bone & Joint Surg, 21 :393-396, 1939. 12. Farmer, A.W.: “Experiences in the Use of Cellophane as an Aid in Tendon Surgery, ” Plast & Reconstruc Surg, 2:207-213, 1947. 13. Gonzales, R.I. : “Experimental Tendon Repair Within the Flexor Tunnels: Use of Polyethylene Tubes for Improvement of Functional Results in the Dog,” Surgery, 26:181-198, 1949. 14. Weckesser, E.C., et al: “A Comparative Study of Various Substances for the Prevention of Adhesions About the Tendons,” Surgery, 25:361-369, 1949. 15. Ashley, F.L. et al: “Experimental and Clinical Studies on the Application of Monomolecular Cellulose Filter Tubes to Create Artificial Tendon Sheaths in Digits,” Plast & Reconstruc Surgery, 23:526-534, 1959. 16. Ashley, F.L. et al: “Further Studies on the Application of Monomolecular, Cellulose Filter Tubes to Create Artificial Tendon Sheaths in the Hand and Wrist,” Pest J Surg, Obst and Gynec, 68:156-161, 1960. 17. Bader, K.F. et al: “Silastic Underlays in Tendon Surgery,” Proc Inst Med of Chicago, 26:21, 1967. 18. Bader, K.F. et al: “Silicone Pulleys and Underlays in Tendon Surgery,” Plast & Reconst Surg, 41 :157-164, 1968. 19. Bader, K.F. et al: “A Successful Silicone Tendon Prosthesis,” AMA Arch Surg, 97:4Q6-411, 1968.
59