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The vascularization of the human flexor pollicis longus tendon
The Vascularization o f the H u m a n Flexor Pollicis Longus Tendon By Goran Lundborg
T H E VASCULARIZATION OF T H E H U M A N F L E X O R P O L L I C I S LONGUS TENDON GORAN LUNDBORG, Gothenburg, Sweden SUMMARY The vascularization of the human flexor pollicis longus tendon was outlined by the use of mieroangiographie techniques, applied on freshly amputated arms. At the insertion of the tendon there was regularly a very well developed vinculnm brevis, often extending proximally to the middle of the base phalanx of the thumb. Proximally to the metacarpo phalangeal joint there was a mesotenon of various shape, originating from the volar-ulnar (non-friction) side of the synovial tendon sheath. There seemed to exist a non-interrupted intrinsic longitudinal vascular system in the tendon, and the vessels were located in those parts of the tendon which are not subjected to friction.
INTRODUCTION The basic biological mechanisms of flexor tendon nutrition and healing have since long been debated and do still not appear completely understood (for reviews see Potenza, 1962, 1963; Matthews and Richards, 1974; Furlow, 1976; McDowell and Snyder, 1977; Ketchum, 1977; Lundborg and Rank, 1978). However, it is generally agreed that the intrinsic vascularization of the injured part of the human flexor tendon is a factor of importance for the healing process, and the negative effects of various types o f tendon sutures on the vascular supply of the tendon has been demonstrated (Bergljung, 1968). The vascular supply of the human flexor tendons within the digital sheath region of the index to little fingers has been outlined by Edwards (1946), Smith, (1965), Caplan, (1976) and others. Recently we have described the intrinsic vascularization of these tendons with special reference to the physiological and functional demands of the friction and gliding surfaces (Lundborg, 1977). In the present study a corresponding description is given of the human flexor pollicis longus tendon. MATERIAL AND METHODS The analyses were performed on five fresh human arms, electively amputated from adult patients because of malignant tumours. Within the first hour after amputation the main arteries of the extremity were cannulated and 6 cc o f 0.5% Lidocain and 4 cc of heparin solution (5000 IE/cc) was infused. The vessels were then perfused with India Ink at a pressure of about 100 mm Hg (13.3 kPa) for one to two hours. The extremity was then fixed in 4~ buffered formaldehyde for at least two weeks. Mid-lateral cutaneous incisions were made on the thumbs and the antebrachial fascia was opened to allow entrance of the fixation medium. * Supported by grants from the Swedish Medical Research Council (project No. 05188), the Swedish Antirheumatoid League, the GOteborg Medical Society, Svenska Livf6rsiikringsbolagens N~tmnd for Medicinsk Forskning Trygg Hansas lbnd for personskadelbrstnmg and Swedish Work Environment Funa. GOran Lundborg, M.D., Hand Surgery Clinic, Sahigren's Hospital, and Lab. of Exp. Biology, Dept. of Anatomy, University of G0teborg, Sweden. 28
The H a n d - - V o l . II
No. 1
1979
The Vascularization o f the H u m a n Flexor Potticis Longus Tendon By GOran Lundborg
~;
!~;i~~!~~i~i!!
i!51;iiiiiil
Fig. 1. The insertion of the flexor pollicis longus tendon in the distal phalanx. Note the well developed vinculum brevis structure.
The thumbs were then dissected. By mid-lateral incisions the flexor system was exposed and the tendon sheath was carefully opened. The vascular pattern of the surface structures were studied under a Leitz stereo-dissection microscope. As a second procedure the tendons were removed and clarified according to the Spalteholz technique (Romeis, 1948) and the deep intrinsic vessels could then be analysed in the transparent tendon.
Fig. 2. An anatomical variant of extrinsic vascular supply of the flexor pollicis longus tendonimmediatel~ distal to the metacarpophalangeal joint (cf. Fig. 3b). (xx) indicates a tiny band running from the distal vinculum brevis on the right to the proximal mesotenon structure. (x) indicates a small vinculum structure arising from this longitudinal band. The H a n d - - Vo/. I I
No. 1
1979
29
The Vascularization o f the Human Flexor Pollicis Longus Tendon By GOran Lundbore
Fig. 3. Various appearance of the extrinsic vascular supply to the flexor pollicis longus tendon as observed in five dissection specimens. Distally at the tendon insertion a well developed vinculum brevis is constantly found. Proximally to the metacarpophalangeal joint there is a mesotenon of various appearance, originating from the volar-ulnar (non-friction) side of the tendon sheath. Distally this mesotenon sometimes condenses into a vinculum longus-like structure (c,d and e; CF: also Fig. 4a and 5). (b) corresponds to Fig. 2, (e) to Fig 4 a a n d b.
Fig. 4a. Flexor pollicis longus tendon (FPL), mesotenon (mt), " v i n c u l u m structures" (v' and v " ) and tendon sheath (xx) Proximal is to the right. The mesotenon originates from the volar-ulnar part of the synovial tendon sheath. Note the avascularity on the friction side of the tendon. (v') corresponds to Fig. 5. Fig. 4b. The mesotenon of Fig. 4a. in higher magnification. Note large central vessel at arrow.
RESULTS The synovial sheath of the flexor pollicis longus tendon is a double walled tube, similar in its construction to the synovial sheath of the other fingers. Distally the sheath extends just distal to the interphalangeal joint of the thumb, proximally it begins at a level 2-2.5 cm proximal to the radio-carpal joint. In the thumb the sheath is re-inforced by three pulleys: At the metacarpo-phalangeal and interphalangeal joints, respectively, and between these both structures there is an oblique pulley structure in the middle of the base phalanx (cf. Doyle, 1977). 30
The Hand-- Vol. 11
No. 1
1979
The Vascularization o f the Human Flexor Pollicis Longus Tendon By GOran Lundborg
The vascularization o f the Flexor Pollicis Longus tendon differs in some respects from that of the other tendons even though the intrinsic vascular pattern is essentially the same. No constant vinculae longa can be found along the tendon. However, most distally at the insertion there is a constant vinculum brevis, which in most cases is extremely well developed and may reach proximally to the middle of the proximal phalanx (Fig. 1). Around the metacarpo-phalangeal joint the vascular anatomy shows some variations, and in most cases there is no extrinsic vascular supply at the level where the tendon passes through the tunnel, constituted by the annular ligament. However, in some cases a very tiny vinculum structure, arising dorsally from an extension from the vinculum brevis or from a very tiny dorsal longitudinal connection between the vinculum brevis and the more proximal " m e s o t e n o n " at the metacarpal level can be found (see Figs. 2, 3). Along the course proximally to the metacarpo-phalangeal joint a " m e s o t e n o n " of variable calibre and length is constantly found (Figs. 4a, 4b). Proximally this structure may extend to the level of the first carpo-metacarpal joint. This structure may be in continuity for a length of 3-4 cms, or it may be separated into several parts by one or more perforations. A frequent finding is a condensation of the mesotenon into a slender vinculum formation at its most distal part corresponding to the metacarpal neck (Fig. 5). In these cases one has the impression o f a true "vinculum longus" structure, reminding o f the vinculum longus structure to the profundus tendon at the proximal interphalangeal joint o f the other fingers. The mesotenon proximal to the metacarpophalangeal joint of the thumb does not arise from the dorsal part o f the tunnel as might be expected, but instead from
Fig. 5.
Detail of Fig. 4a: the area around (v') after clarification. A vinculum Iongus like structure (v) originates from the synovial tendon sheath (xx) and approaches the non-friction side of the tendon (FPL).
Fig. 6.
Clarified tendon proximal to the metacarpophalangeal joint level. Arrows indicate the friction surface of the tendon. Note the concentration o f intrinsic vessels in the non-friction parts of the tendon.
TheHand--Vol. 11
No. 1
1979
31
The Vascularization o f the Human Flexor Pollicis Longus Tendon By GOran Lundborg
the volar-ulnar part of the synovial tube. This is in good line with the mechanical forces, acting on the tendon at this level; as a whole the tendon describes along its course a " S " - f o r m with a volar, concave shape at the metacarpophalangeal joint and distally from that level, but a dorsal concave shape proximally to this level, i.e. along the base of the first metacarpal and the carpo-metacarpal joint (Fig. 3). The friction forces are acting on the concave surfaces of the tendon, which are devoid of vessels (Fig. 4). The vascular structures including the extrinsic vascular supply are concentrated on the non-friction side of the tendon, i.e. volarly at the level of the mesotenon, but dorsally distally to the metacarpophalangeal joint. The intrinsic vessels of the tendon are concentrated within the corresponding parts of the tendon (Fig. 4). This intrinsic vascular net appears longitudinally continuous throughout the length of the tendon. DISCUSSION
The " v i n c u l u m " system of the flexor tendons in index, middle, ring and little fingers is well known from studies by Edwards 1948, Smith 1965, Caplan 1976 and Lundborg 1977. The "vinculae brevia" are well developed structures at the insertions of the profundus and superficialis tendons, respectively, while the "vinculae longa" are more slender, mobile structures along the course of the tendons. The present investigation shows that the flexor pollicis longus tendon exhibits a very well developed "vinculum brevis" at the insertion of the tendon, often extending proximally even to the middle of the base phalanx. Hereby an avulsion of the tendon insertion from the distal phalanx may not render the distal interphalangeal joint completely immob{le, since the extensive "vinculum brevis" structure may transmit some of the pulling force from the tendon to the distal phalanx. The flexor pollicis longus tendon does not exhibit any true ~'vinculum longus", but rather a " m e s o t e n o n " of various length. This structure is generally very rich in vessels, and as a whole the extrinsic vascular supply of the flexor pollicis longus tendon appears better developed as compared to the tendons of the remaining fingers. The " m e s o t e n o n " of the flexor pollicis longus tendon might contribute to the limited retraction which might be seen at a distal severence of the tendon. Due to the " S " form of the flexor pollicis longus tendon along its course, the friction in the distal part is applied on the volar tendon surface, but proximally on the dorsal surface. These surfaces were found to be devoid of vessels, indicating that vessels can be expected to be perfused under this type of mechanical stress. Most probably these friction bearing areas of the tendon are nourished via diffusional pathways from the synovial fluid in analogy with our previous findings on the corresponding areas of the other flexor tendons of the hand (Lundborg 1977). It is well known that primary suture of the flexor pollicis longus tendon gives comparatively good results with satisfactory function of the thumb. This might in part be due to the fact that no excessive range of active motion is required in the distal interphalangeal joint of the thumb, as a stabilising function against the other mobile fingers of the hand often can be sufficient. However, one should not exclude the possibility that the well developed extrinsic vascular supply and the continuous intrinsic vascular system of the flexor pollicis longus tendon makes this tendon less easily devascularized by injury as compared to the flexor tendon of the other digits, hereby contributing to a more favourable healing with less risk of elongation at the suture line. 32
TheHand--Vol. 11
No. 1
1979
The Vascularization o f the Human Flexor Pollicis Tendon By GOran Lundborg
REFERENCES B E R G L J U N G , L. (1968) Vascular Reactions After Tendon Suture A n d Tendon Transplantation. A Stereo-Microangiographic Study on the Calcanean Tendon of the Rabbit. Scandinavian Journal of Plastic and Reconstructive Surgery Supplement: 4. (1968) C A P L A N , H. S., H U N T E R , J. M. and MERKL1N, R. J. Intrinsic vascularisation of flexor tendons. In: A A O S Symposium on Tendon Surgery In The Hand. St. Louis. The C.V. Mosby Company. 1975. pp 48-58. DOYLE, J. R., BLYTHE, W. F. (1977) A n a t o m y of the flexor tendon sheath and pulleys of the thumb. The Journal of H a n d Surgery, 2: 149-151. E D W A R D S , D. A. W. (1946) The Blood Supply and Lymphatic Drainage Of Tendons. Journal of Anatomy, 80: 147-152. F U R L O W , L. T. (1976) The Role of Tendon Tissues in Tendon Healing. Plastic and Reconstructive Surgery, 57: 39-49. K E T C H U M , L. D. (1977) Primary tendon healing: A review. The Journal of Hand Surgery, 2: 428-435. L U N D B O R G , G. and M Y R H A G E , R. (1977) The Vascularization A n d Structure Of The H u m a n Digital Tendon Sheath As Related To Flexor Tendon Function. Scandinavian Journal of Plastic and Reconstructive Surgery, 11 : 195-203. L U N D B O R G , G., M Y R H A G E , R. and RYDEV1K, B. (1977) The vascularisation of h u m a n flexor tendons within the digital synoviat sheath region - - structural and functional aspects. The Journal of Hand Surgery, 2: 417-427. L U N D B O R G , G. and RANK, F. (1978) Experimental intrinsic healing of flexor tendons based upon synovial fluid nutrition. The Journal of Hand Surgery, 3: 21-31. M A T T H E W S , P. and R I C H A R D S , H. (1974) The Repair Potential of Digital Flexor Tendons. The Journal of Bone and Joint Surgery, 56-B: 618-625. M c D O W E L L , C. L. and SNYDER, D. M. (1977) Tendon healing: An experimental model in the dog. The Journal of Hand Surgery, 2: 122-126. P E A C O C K , E. E. Jr. (1965) Biological Principles in the Healing of Long Tendons. Surgical Clinics of North America. 45:461-476. P O T E N Z A , A. D. (1962) Tendon Healing Within the Flexor Digital Sheath in the Dog. The Journal of Bone and Joint Surgery, 44-A: 49-64. P O T E N Z A , A. D. (1963) Critical Evaluation of Flexor-Tendon Healing and Adhesion Formation within Artificial Digital Sheaths. The Journal of Bone and Joint Surgery, 45-A: 1217-1233. ROMEIS, B. (1948)Taschenbuch Der Mikroskopischen Technik, Munc!aen , Berlin Verlag von R. Oldenbourg, M0nchen. p.200. SMITH, J. W. (1965) Blood Supply of Tendons. The American Journal of Surgery, 109: 272-276.
The Hand--Vol. II
No. 1
1979
33
T H E VASCULARIZATION OF T H E H U M A N F L E X O R P O L L I C I S LONGUS TENDON GORAN LUNDBORG, Gothenburg, Sweden SUMMARY The vascularization of the human flexor pollicis longus tendon was outlined by the use of mieroangiographie techniques, applied on freshly amputated arms. At the insertion of the tendon there was regularly a very well developed vinculnm brevis, often extending proximally to the middle of the base phalanx of the thumb. Proximally to the metacarpo phalangeal joint there was a mesotenon of various shape, originating from the volar-ulnar (non-friction) side of the synovial tendon sheath. There seemed to exist a non-interrupted intrinsic longitudinal vascular system in the tendon, and the vessels were located in those parts of the tendon which are not subjected to friction.
INTRODUCTION The basic biological mechanisms of flexor tendon nutrition and healing have since long been debated and do still not appear completely understood (for reviews see Potenza, 1962, 1963; Matthews and Richards, 1974; Furlow, 1976; McDowell and Snyder, 1977; Ketchum, 1977; Lundborg and Rank, 1978). However, it is generally agreed that the intrinsic vascularization of the injured part of the human flexor tendon is a factor of importance for the healing process, and the negative effects of various types o f tendon sutures on the vascular supply of the tendon has been demonstrated (Bergljung, 1968). The vascular supply of the human flexor tendons within the digital sheath region of the index to little fingers has been outlined by Edwards (1946), Smith, (1965), Caplan, (1976) and others. Recently we have described the intrinsic vascularization of these tendons with special reference to the physiological and functional demands of the friction and gliding surfaces (Lundborg, 1977). In the present study a corresponding description is given of the human flexor pollicis longus tendon. MATERIAL AND METHODS The analyses were performed on five fresh human arms, electively amputated from adult patients because of malignant tumours. Within the first hour after amputation the main arteries of the extremity were cannulated and 6 cc o f 0.5% Lidocain and 4 cc of heparin solution (5000 IE/cc) was infused. The vessels were then perfused with India Ink at a pressure of about 100 mm Hg (13.3 kPa) for one to two hours. The extremity was then fixed in 4~ buffered formaldehyde for at least two weeks. Mid-lateral cutaneous incisions were made on the thumbs and the antebrachial fascia was opened to allow entrance of the fixation medium. * Supported by grants from the Swedish Medical Research Council (project No. 05188), the Swedish Antirheumatoid League, the GOteborg Medical Society, Svenska Livf6rsiikringsbolagens N~tmnd for Medicinsk Forskning Trygg Hansas lbnd for personskadelbrstnmg and Swedish Work Environment Funa. GOran Lundborg, M.D., Hand Surgery Clinic, Sahigren's Hospital, and Lab. of Exp. Biology, Dept. of Anatomy, University of G0teborg, Sweden. 28
The H a n d - - V o l . II
No. 1
1979
The Vascularization o f the H u m a n Flexor Potticis Longus Tendon By GOran Lundborg
~;
!~;i~~!~~i~i!!
i!51;iiiiiil
Fig. 1. The insertion of the flexor pollicis longus tendon in the distal phalanx. Note the well developed vinculum brevis structure.
The thumbs were then dissected. By mid-lateral incisions the flexor system was exposed and the tendon sheath was carefully opened. The vascular pattern of the surface structures were studied under a Leitz stereo-dissection microscope. As a second procedure the tendons were removed and clarified according to the Spalteholz technique (Romeis, 1948) and the deep intrinsic vessels could then be analysed in the transparent tendon.
Fig. 2. An anatomical variant of extrinsic vascular supply of the flexor pollicis longus tendonimmediatel~ distal to the metacarpophalangeal joint (cf. Fig. 3b). (xx) indicates a tiny band running from the distal vinculum brevis on the right to the proximal mesotenon structure. (x) indicates a small vinculum structure arising from this longitudinal band. The H a n d - - Vo/. I I
No. 1
1979
29
The Vascularization o f the Human Flexor Pollicis Longus Tendon By GOran Lundbore
Fig. 3. Various appearance of the extrinsic vascular supply to the flexor pollicis longus tendon as observed in five dissection specimens. Distally at the tendon insertion a well developed vinculum brevis is constantly found. Proximally to the metacarpophalangeal joint there is a mesotenon of various appearance, originating from the volar-ulnar (non-friction) side of the tendon sheath. Distally this mesotenon sometimes condenses into a vinculum longus-like structure (c,d and e; CF: also Fig. 4a and 5). (b) corresponds to Fig. 2, (e) to Fig 4 a a n d b.
Fig. 4a. Flexor pollicis longus tendon (FPL), mesotenon (mt), " v i n c u l u m structures" (v' and v " ) and tendon sheath (xx) Proximal is to the right. The mesotenon originates from the volar-ulnar part of the synovial tendon sheath. Note the avascularity on the friction side of the tendon. (v') corresponds to Fig. 5. Fig. 4b. The mesotenon of Fig. 4a. in higher magnification. Note large central vessel at arrow.
RESULTS The synovial sheath of the flexor pollicis longus tendon is a double walled tube, similar in its construction to the synovial sheath of the other fingers. Distally the sheath extends just distal to the interphalangeal joint of the thumb, proximally it begins at a level 2-2.5 cm proximal to the radio-carpal joint. In the thumb the sheath is re-inforced by three pulleys: At the metacarpo-phalangeal and interphalangeal joints, respectively, and between these both structures there is an oblique pulley structure in the middle of the base phalanx (cf. Doyle, 1977). 30
The Hand-- Vol. 11
No. 1
1979
The Vascularization o f the Human Flexor Pollicis Longus Tendon By GOran Lundborg
The vascularization o f the Flexor Pollicis Longus tendon differs in some respects from that of the other tendons even though the intrinsic vascular pattern is essentially the same. No constant vinculae longa can be found along the tendon. However, most distally at the insertion there is a constant vinculum brevis, which in most cases is extremely well developed and may reach proximally to the middle of the proximal phalanx (Fig. 1). Around the metacarpo-phalangeal joint the vascular anatomy shows some variations, and in most cases there is no extrinsic vascular supply at the level where the tendon passes through the tunnel, constituted by the annular ligament. However, in some cases a very tiny vinculum structure, arising dorsally from an extension from the vinculum brevis or from a very tiny dorsal longitudinal connection between the vinculum brevis and the more proximal " m e s o t e n o n " at the metacarpal level can be found (see Figs. 2, 3). Along the course proximally to the metacarpo-phalangeal joint a " m e s o t e n o n " of variable calibre and length is constantly found (Figs. 4a, 4b). Proximally this structure may extend to the level of the first carpo-metacarpal joint. This structure may be in continuity for a length of 3-4 cms, or it may be separated into several parts by one or more perforations. A frequent finding is a condensation of the mesotenon into a slender vinculum formation at its most distal part corresponding to the metacarpal neck (Fig. 5). In these cases one has the impression o f a true "vinculum longus" structure, reminding o f the vinculum longus structure to the profundus tendon at the proximal interphalangeal joint o f the other fingers. The mesotenon proximal to the metacarpophalangeal joint of the thumb does not arise from the dorsal part o f the tunnel as might be expected, but instead from
Fig. 5.
Detail of Fig. 4a: the area around (v') after clarification. A vinculum Iongus like structure (v) originates from the synovial tendon sheath (xx) and approaches the non-friction side of the tendon (FPL).
Fig. 6.
Clarified tendon proximal to the metacarpophalangeal joint level. Arrows indicate the friction surface of the tendon. Note the concentration o f intrinsic vessels in the non-friction parts of the tendon.
TheHand--Vol. 11
No. 1
1979
31
The Vascularization o f the Human Flexor Pollicis Longus Tendon By GOran Lundborg
the volar-ulnar part of the synovial tube. This is in good line with the mechanical forces, acting on the tendon at this level; as a whole the tendon describes along its course a " S " - f o r m with a volar, concave shape at the metacarpophalangeal joint and distally from that level, but a dorsal concave shape proximally to this level, i.e. along the base of the first metacarpal and the carpo-metacarpal joint (Fig. 3). The friction forces are acting on the concave surfaces of the tendon, which are devoid of vessels (Fig. 4). The vascular structures including the extrinsic vascular supply are concentrated on the non-friction side of the tendon, i.e. volarly at the level of the mesotenon, but dorsally distally to the metacarpophalangeal joint. The intrinsic vessels of the tendon are concentrated within the corresponding parts of the tendon (Fig. 4). This intrinsic vascular net appears longitudinally continuous throughout the length of the tendon. DISCUSSION
The " v i n c u l u m " system of the flexor tendons in index, middle, ring and little fingers is well known from studies by Edwards 1948, Smith 1965, Caplan 1976 and Lundborg 1977. The "vinculae brevia" are well developed structures at the insertions of the profundus and superficialis tendons, respectively, while the "vinculae longa" are more slender, mobile structures along the course of the tendons. The present investigation shows that the flexor pollicis longus tendon exhibits a very well developed "vinculum brevis" at the insertion of the tendon, often extending proximally even to the middle of the base phalanx. Hereby an avulsion of the tendon insertion from the distal phalanx may not render the distal interphalangeal joint completely immob{le, since the extensive "vinculum brevis" structure may transmit some of the pulling force from the tendon to the distal phalanx. The flexor pollicis longus tendon does not exhibit any true ~'vinculum longus", but rather a " m e s o t e n o n " of various length. This structure is generally very rich in vessels, and as a whole the extrinsic vascular supply of the flexor pollicis longus tendon appears better developed as compared to the tendons of the remaining fingers. The " m e s o t e n o n " of the flexor pollicis longus tendon might contribute to the limited retraction which might be seen at a distal severence of the tendon. Due to the " S " form of the flexor pollicis longus tendon along its course, the friction in the distal part is applied on the volar tendon surface, but proximally on the dorsal surface. These surfaces were found to be devoid of vessels, indicating that vessels can be expected to be perfused under this type of mechanical stress. Most probably these friction bearing areas of the tendon are nourished via diffusional pathways from the synovial fluid in analogy with our previous findings on the corresponding areas of the other flexor tendons of the hand (Lundborg 1977). It is well known that primary suture of the flexor pollicis longus tendon gives comparatively good results with satisfactory function of the thumb. This might in part be due to the fact that no excessive range of active motion is required in the distal interphalangeal joint of the thumb, as a stabilising function against the other mobile fingers of the hand often can be sufficient. However, one should not exclude the possibility that the well developed extrinsic vascular supply and the continuous intrinsic vascular system of the flexor pollicis longus tendon makes this tendon less easily devascularized by injury as compared to the flexor tendon of the other digits, hereby contributing to a more favourable healing with less risk of elongation at the suture line. 32
TheHand--Vol. 11
No. 1
1979
The Vascularization o f the Human Flexor Pollicis Tendon By GOran Lundborg
REFERENCES B E R G L J U N G , L. (1968) Vascular Reactions After Tendon Suture A n d Tendon Transplantation. A Stereo-Microangiographic Study on the Calcanean Tendon of the Rabbit. Scandinavian Journal of Plastic and Reconstructive Surgery Supplement: 4. (1968) C A P L A N , H. S., H U N T E R , J. M. and MERKL1N, R. J. Intrinsic vascularisation of flexor tendons. In: A A O S Symposium on Tendon Surgery In The Hand. St. Louis. The C.V. Mosby Company. 1975. pp 48-58. DOYLE, J. R., BLYTHE, W. F. (1977) A n a t o m y of the flexor tendon sheath and pulleys of the thumb. The Journal of H a n d Surgery, 2: 149-151. E D W A R D S , D. A. W. (1946) The Blood Supply and Lymphatic Drainage Of Tendons. Journal of Anatomy, 80: 147-152. F U R L O W , L. T. (1976) The Role of Tendon Tissues in Tendon Healing. Plastic and Reconstructive Surgery, 57: 39-49. K E T C H U M , L. D. (1977) Primary tendon healing: A review. The Journal of Hand Surgery, 2: 428-435. L U N D B O R G , G. and M Y R H A G E , R. (1977) The Vascularization A n d Structure Of The H u m a n Digital Tendon Sheath As Related To Flexor Tendon Function. Scandinavian Journal of Plastic and Reconstructive Surgery, 11 : 195-203. L U N D B O R G , G., M Y R H A G E , R. and RYDEV1K, B. (1977) The vascularisation of h u m a n flexor tendons within the digital synoviat sheath region - - structural and functional aspects. The Journal of Hand Surgery, 2: 417-427. L U N D B O R G , G. and RANK, F. (1978) Experimental intrinsic healing of flexor tendons based upon synovial fluid nutrition. The Journal of Hand Surgery, 3: 21-31. M A T T H E W S , P. and R I C H A R D S , H. (1974) The Repair Potential of Digital Flexor Tendons. The Journal of Bone and Joint Surgery, 56-B: 618-625. M c D O W E L L , C. L. and SNYDER, D. M. (1977) Tendon healing: An experimental model in the dog. The Journal of Hand Surgery, 2: 122-126. P E A C O C K , E. E. Jr. (1965) Biological Principles in the Healing of Long Tendons. Surgical Clinics of North America. 45:461-476. P O T E N Z A , A. D. (1962) Tendon Healing Within the Flexor Digital Sheath in the Dog. The Journal of Bone and Joint Surgery, 44-A: 49-64. P O T E N Z A , A. D. (1963) Critical Evaluation of Flexor-Tendon Healing and Adhesion Formation within Artificial Digital Sheaths. The Journal of Bone and Joint Surgery, 45-A: 1217-1233. ROMEIS, B. (1948)Taschenbuch Der Mikroskopischen Technik, Munc!aen , Berlin Verlag von R. Oldenbourg, M0nchen. p.200. SMITH, J. W. (1965) Blood Supply of Tendons. The American Journal of Surgery, 109: 272-276.
The Hand--Vol. II
No. 1
1979
33