Flexor Digitorum Superficialis Tendon Injuries in Zone II: To Repair or Not

Background: Attaining favorable functional results afterflexor tendon repair in zone II has always been a complextask. This is primarily due to the cramped positioning of theflexor digitorum profundus (FDP) and the two slips of theflexor digitorum superficialis (FDS) within a narrow fibroosseoustunnel. Such a confined space significantly increasesthe risk of postoperative adhesions and consequent limitationsin postoperative range of motion and strength. The primaryobjectives of tendon restoration revolve around enhancingtendon healing and minimizing adhesion formation.Objective: The objective of this study is to evaluate theclinical outcomes after surgery by assessing postoperativerange of motion (ROM) and radiological findings usingMusculoskeletal Ultrasound (MSK US). Specifically, we aimto compare the results between cases where both the flexordigitorum profundus (FDP) and flexor digitorum superficialis(FDS) tendons are repaired in Zone II flexor tendon injuries,and cases where only the FDP tendon is repaired. Additionally,we will examine the formation of granulation tissue as aparameter in our evaluation.Patients and Methods: This interventional clinical trialinvolves a total of fifty individuals who have experiencedflexor tendon injuries in zone II. The patients were selectedfrom those who underwent surgery at El Dmerdash Hospital,based on the inclusion and exclusion criteria outlined in ourstudy. A random sampling method was employed to dividethe patients into two groups. Group I consist of twenty-fivepatients (the study group) who underwent repair of both theflexor digitorum profundus (FDP) and flexor digitorum superficialis(FDS) tendons. Group II comprises twenty-fivepatients (the control group) who underwent repair of only theFDP tendon.Results: In our investigation, 50 cases with four strandrepairs of zone II flexor tendon injuries were considered. Therehabilitation and follow-up procedures were the same forboth groups. According to Strickland criteria, the results weremeasured in terms of total range of motion and revealedsignificant differences between the two groups. Group withrepair of both FDP and FDS has a higher range of motion.MSK US showed a higher rate of granulation tissue formationin group I but was not statistically significant.319Conclusion: In the management of flexor tendon injurieszone II, we recommend repairing both FDP tendon and FDStendon to keep the integrity of full motion of the digit.Repairing both slips of FDS in addition to FDP tendon mayincrease the granulation tissue formation which impairs glidingbut that can be avoided by routine post-operative physiotherapyand avoid bulky intra-operative repair.