الفهرس 
ANATOMY AND BIOMECHANICS OF FLEXOR TENDONSOnly 14 pages are availabe for public view
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Abstract
Obtaining good functional outcomes after flexor tendon repair in zone II has always become a challenge due to being crowded by the FDP and the two slips of the FDS within a tight fibrossoeus tunnel, thus increasing the possibility of postoperative adhesions leading to a decrease in the postoperative range of motion and power.
Early postoperative active motion accelerates healing and decreases adhesion formation. The desire for maximal mobilization is obviously restricted by an increased risk of rupture. This nessicates the presence of a strong repair that permits early motion.
Traditionally the double strand modified Kessler repair using a non absorbable suture material, mostly polypropylene is used by most surgeons nowadays.
The aim of this work is to evaluate the use of polydiaxanone (PDS) as a suture material as well as to compare 2 repair techniques, the Double strand repair (Modified Kessler) and multi-strand repair (Six strand Savage) in zone II flexor digitorum profundus tendon injury as regard Strength of the repair, range of motion and active flexion against resistance, in attempt to reach a strong repair that can permit early active motion.
This thesis included both cadaveric and clinical studies. The cadaveric study included forty specimens of FDP tendons harvested from human cadaveric tendons, categorized into three groups, Group (A) included 20 specimens as a control group. Group (B) included 10 specimens sutured by modified Kessler suture technique + epitendinous continuous running sutures using PDS suture material. Group (C) included 10 specimens sutured by six strand savage suture technique + epitendinous continuous running sutures using PDS suture material.
The three groups were tested for tensile strength using a tensile strength measuring machine (NEXYGEN LR 5K plus from Lloyd Instruments Ltd).
The results of the cadaveric study showed a significant difference in the strength of the repair. The mean breaking force of the double strand repair using PDS suture material was 35.9 N and of the six strand repair using PDS suture material was 97.6 N.
The clinical study included forty cases of injured FDP tendons in zone II. The repaired tendons were subdivided into 2 groups: Group (1) which included twenty tendons managed by modified Kessler suture technique (as an example of double strand repair) and Group (2) which included twenty tendons that were managed by six-strand Savage suture technique (as an example of multi-strand repair). In both groups 4/0 PDS was used for the core suture and 6/0 PDS for the peripheral suture.
All patients were subjected to a 7 week postoperative regimen of controlled early motion and finally evaluated after six months for the range of motion using the Buck-Gramcko criteria and for active motion against resistance using a new method advocated in this thesis to measure a single finger active motion against resistance allowing the patient to elevate different weights of sand bags by his finger-tip while fixing the MCP and PIP and measuring how many grams he can elevate and then comparing it with the corresponding finger of the other uninjured hand.
The outcome of the clinical study showed that the six strand Savage technique using PDS suture material demonstrated better range of motion with very good to excellent results in 80% (16/20) of patients. There were no cases of tendon rupture. On the other hand, the two strand modified Kessler repair using PDS suture material showed very good to excellent results in only 35% (7/20) of patients with one case of tendon rupture.
In this study a difference in the active flexion against resistance was found in the normal uninjured fingers being the highest in the index finger (average 2500 grams) and the least in the little finger (average 1500 grams). As regard the active motion against resistance there was highly statistically significant difference between the two studied groups. In the six strand Savage group there was an average of 350 grams difference between the injured and non injured fingers, while in the modified Kessler group there was an average of 640 grams difference between the injured and non injured fingers.
In conclusion, the six strand savage technique using PDS suture material is a strong and safe technique that can permit early active motion with better range of motion and active motion against resistance than the conventional double strand modified Kessler.
The six strand savage, in my opinion, has the disadvantages of being time consuming, technically difficult and bulky especially for small tendons. A simplest six strand or even a four strand repair can be investigated to avoid these disadvantages.