FDP repair refers to medical procedures to fix injuries to the Flexor Digitorum Profundus (FDP) tendon. Located in the hand, this tendon is crucial for bending the fingertips and enabling effective hand use.
Understanding FDP Tendon Injuries
The Flexor Digitorum Profundus (FDP) tendon originates in the forearm, extends through the wrist, and attaches to the base of the distal phalanges of the index, middle, ring, and little fingers. Its primary function is to flex the distal interphalangeal (DIP) joints, allowing for a strong grip and the ability to make a full fist.
FDP tendons can sustain injuries through various mechanisms. Lacerations from sharp objects, like knives or glass, can sever the tendon. Avulsion injuries occur when the tendon pulls away from the bone, often during forceful finger extension while the FDP muscle is contracting. This is frequently seen in contact sports and is known as “jersey finger.” These injuries compromise the ability to bend the fingertips, impacting hand function.
Diagnosing FDP Injuries
Diagnosing an FDP injury begins with a medical history, where the professional asks about the injury’s cause and symptoms. This is followed by a physical examination of the hand and fingers. The doctor checks for visible signs like swelling or bruising and assesses the hand’s resting posture.
Specific tests evaluate the FDP tendon’s integrity. Patients are asked to bend their fingertip while other fingers are held straight; inability to flex the distal interphalangeal (DIP) joint indicates an FDP rupture. X-rays are used to rule out bone fractures, especially in avulsion injuries. While clinical examination is often sufficient, ultrasound or MRI may be used in ambiguous cases or to assess soft tissue damage.
Treatment Approaches for FDP Repair
Surgical repair is the primary treatment for most complete FDP tendon injuries, including lacerations and avulsions. The goal is to reattach severed tendon ends or reinsert an avulsed tendon to its bony attachment, restoring tendon continuity for proper finger flexion and grip strength.
During surgery, a zigzag incision is made on the palm side of the finger to expose the injured tendon while protecting neurovascular structures. The surgeon identifies the retracted tendon ends. Tendon repair involves using strong sutures to bring the ends together, ensuring adequate strength for early rehabilitation.
Various suturing techniques are employed, including multi-strand core sutures, often augmented to enhance strength. For avulsion injuries, a “pull-out” suture technique may be used. In complex cases with significant tissue loss or delayed presentation, a tendon graft may be necessary to bridge the gap. Non-surgical management is generally not an option for complete FDP ruptures due to significant function loss, though partial tears may be managed non-operatively.
Recovery and Rehabilitation After FDP Repair
The post-operative period after FDP repair focuses on controlled recovery and structured rehabilitation. Immediately after surgery, the hand is placed in a dorsal blocking splint. This splint protects the healing tendon from re-rupture and is worn continuously for 3 to 6 weeks, removed only for exercises and hygiene.
Hand therapy protocols are tailored to the surgical repair’s strength. Early phases involve passive range of motion exercises, where the repaired finger is gently moved through a controlled range of flexion and extension. This motion helps prevent adhesions (scar tissue) from forming around the tendon, which could restrict its gliding ability.
Around 3 to 4 weeks, “place and hold” exercises are introduced, allowing the patient to actively hold a flexed finger position. Active, non-resistive digital flexion and extension exercises begin around 4 to 6 weeks, gradually increasing range of motion. Strengthening exercises are initiated around 8 weeks post-operation, progressing as the tendon gains strength. Adherence to these phased therapy protocols is important for good functional outcomes and minimizing complications like re-rupture.
Expected Outcomes and Long-Term Management
Patients undergoing FDP repair can expect significant improvement in finger function, though full pre-injury function may not always be achieved. Recovery for regaining strength and full range of motion can extend for several months, with progress continuing for 6 months to a year. Adherence to the prescribed rehabilitation protocol is important for the final outcome.
Challenges can arise during long-term recovery. Stiffness in the interphalangeal joints and adhesions are common complications that may limit active range of motion. Additional procedures like tenolysis (surgical release of adhesions) may be required if conservative therapy is insufficient. Re-rupture remains a possibility, especially if rehabilitation protocols are not followed. Continued home exercises and adaptive strategies may be necessary to maintain function and manage any residual stiffness or limitations.