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Flexor Tendon Repair: A Comprehensive Orthopedic Guide

FRCS Oral: Abbreviated Jersey Finger Examination Prep

23 Apr 2026 117 min read 114 Views
Illustration of examination abbreviated jersey - Dr. Mohammed Hutaif

Key Takeaway

Your ultimate guide to FRCS Oral: Abbreviated Jersey Finger Examination Prep starts here. An examination abbreviated jersey finger primarily tests Flexor Digitorum Profundus (FDP) function. This involves fixing the middle phalanx in extension and asking the patient to actively flex the distal interphalangeal joint (DIPJ). Inability to flex the DIPJ confirms a ruptured FDP tendon. Radiographs may show an avulsion fracture.

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Question 1

A 24-year-old rugby player presents 48 hours after sustaining an injury to his left ring finger while tackling an opponent. He reports his finger was forcibly extended while he was gripping the opponent's jersey. On examination, he has swelling and tenderness over the palmar aspect of the distal phalanx. He is unable to actively flex the DIP joint of the ring finger. The remaining fingers show normal cascade. Passive DIP flexion is full. X-rays show no bony avulsion. Which of the following Leddy and Packer types is most likely, and what is the primary concern driving urgent treatment?





Explanation

This scenario describes a classic Type I Jersey finger. A Type I injury involves rupture of the FDP tendon without a bony avulsion, and the tendon typically retracts into the palm, losing its vincula blood supply. The primary concern driving the urgency for repair (ideally within 7-10 days, but sooner if possible) is the preservation of the tendon's intrinsic vascularity to prevent necrosis and facilitate healing. Type II also lacks a bony avulsion but the tendon is retained at the A3 pulley level, often with intact vincula, making it less urgent than Type I. Type III involves a bony avulsion fragment, which prevents further retraction and maintains tendon blood supply, making it less urgent. Type IV involves an avulsed bone fragment with the tendon avulsed from the fragment, and Type V involves an intra-articular fracture with tendon avulsion; these are also distinct from the given scenario.

Question 2

Regarding the surgical repair of a chronic FDP rupture (presenting 6 months post-injury) in a 35-year-old manual laborer, which of the following is the most appropriate initial management strategy if direct primary repair is not feasible?





Explanation

For chronic FDP ruptures where direct primary repair is not feasible due to significant tendon retraction and shortening, staged tendon reconstruction using a silicone rod (Hunter rod) is often the preferred strategy. The silicone rod creates a pseudosheath, which then facilitates the passage of an autogenous tendon graft (commonly palmaris longus or plantaris) in a second stage. FDP advancement is only feasible for gaps typically less than 1 cm. Delayed primary repair with an interpositional graft is a possibility, but less predictable than staged reconstruction for significant gaps. Amputation is overly aggressive, and observation alone will not restore function in a chronic rupture.

Question 3

A 19-year-old basketball player presents with a suspected Jersey finger of his small finger. On examination, he has full active flexion of his PIP joint but lacks active flexion of his DIP joint. A modified tabletop test reveals a normal cascade for all fingers except the small finger, which remains extended at the DIP joint. What is the most reliable maneuver to confirm an FDP rupture in this digit?





Explanation

The most reliable maneuver to confirm an FDP rupture is to isolate the action of the FDP tendon. This is done by stabilizing the PIP joint in full extension and asking the patient to actively flex the DIP joint. If the FDP is ruptured, active DIP flexion will be absent. Assessing passive range of motion will typically be full, as the FDP rupture is an active deficit. Palpating a tender gap can be indicative but is not always reliable, especially with swelling. Grip strength is a global measure and not specific enough. Finkelstein's test is for De Quervain's and irrelevant here.

Question 4

Which of the following statements most accurately describes the 'quadriga effect' as a potential complication following FDP repair, particularly when using advancement techniques?





Explanation

The quadriga effect is a well-known complication of FDP repair, particularly when the tendon is shortened (e.g., through advancement or overtightening during repair). Because the FDP tendons of the medial four fingers share a common muscle belly (or are closely intertwined proximally), overtensioning of one FDP tendon will restrict full flexion of the adjacent, healthy FDP tendons. This results in the inability of the adjacent digits to fully flex. The other options describe different complications or aspects of tendon repair.

Question 5

A 40-year-old construction worker sustained a Jersey finger injury to his index finger 3 weeks ago. X-rays reveal a small bony avulsion fragment from the palmar aspect of the distal phalanx, with the fragment retracted to the level of the A4 pulley. He has minimal pain but lacks active DIP flexion. Which Leddy and Packer type is this, and what is the typical management recommendation?





Explanation

This is a classic Type III Leddy and Packer injury. It involves a bony avulsion fragment from the distal phalanx that typically retracts to the A4 pulley. The key feature is that the bone fragment prevents further tendon retraction and, importantly, preserves the tendon's blood supply via the vincula. This makes the repair less urgent than a Type I or even Type II injury, allowing for repair up to 3-4 weeks post-injury without significantly compromising outcomes. Immediate repair is for Type I. Type II lacks a bony fragment. Type IV involves tendon avulsed from the fragment. Type V involves an intra-articular fracture.

Question 6

Which of the following anatomical structures is MOST critical for providing blood supply to the flexor digitorum profundus (FDP) tendon in the distal finger, particularly relevant in Type I Jersey finger injuries?





Explanation

The vincula tendinum are mesotendinous structures that connect the flexor tendons to the phalanges and provide the primary blood supply to the tendons within the flexor sheath. In a Type I Jersey finger, the FDP tendon avulses distal to the vincula longa and retracts into the palm, often stripping it of its vincula and thus its blood supply, leading to a high risk of tendon necrosis. The A2 pulley is a critical mechanical structure but not primarily a source of blood supply to the tendon itself. The flexor sheath provides an environment, not the primary blood supply. Annular ligaments are the pulleys. Lumbrical muscles have their own blood supply but do not supply the FDP tendon directly.

Question 7

A 28-year-old rock climber presents with chronic stiffness and an inability to fully extend her ring finger DIP joint 8 months after a surgically repaired Jersey finger. Radiographs show no fracture or hardware issues. This is most likely due to:





Explanation

Chronic stiffness and limited range of motion, particularly an inability to fully extend, following flexor tendon repair are most commonly due to adhesions forming within the flexor sheath. This restricts the smooth gliding of the repaired tendon. Re-rupture would present with loss of active flexion, not stiffness in extension. Quadriga effect limits flexion of adjacent fingers. Lumbrical plus phenomenon involves paradoxical DIP extension with attempted strong grip. Insufficient extensor strength would primarily affect active extension, not passive range of motion if adhesions are the cause.

Question 8

When performing a primary repair of a retracted FDP tendon, which of the following is considered the gold standard suture technique for strength and preventing pull-out?





Explanation

The gold standard for flexor tendon repair involves a strong core suture technique that provides robust mechanical strength against gapping and pull-out. The Modified Kessler (or similar variations like Lim-Tsai, Modified Becker, Pennington) is a common and effective core suture. An epitendinous suture is typically used in addition to a core suture to create a smooth gliding surface and add some strength, but it is not sufficient on its own for primary repair strength. Simple interrupted, horizontal mattress, and running locking sutures are not typically used as primary core sutures in flexor tendon repair due to lower strength and potential for gapping or strangulation.

Question 9

What is the typical presentation of a 'lumbrical plus' phenomenon, which can be a complication of FDP repair or shortening?





Explanation

The 'lumbrical plus' phenomenon occurs when the FDP tendon is advanced and overtensioned, or the repair site is too stiff, causing the lumbrical muscle to be pulled proximally. When the patient attempts to flex the finger (activating the FDP), the lumbrical is put under tension before the FDP can flex the DIP joint. Since the lumbrical inserts into the extensor mechanism, its contraction paradoxically extends the DIP joint instead of allowing FDP flexion. This results in the DIP joint extending or remaining extended when the patient attempts to make a full fist. Option E describes the quadriga effect.

Question 10

A 16-year-old athlete presents with an acute Jersey finger (Type I Leddy and Packer) of his long finger. He is scheduled for surgical repair. What is the most common approach to access the FDP tendon and achieve primary repair?





Explanation

The Brunner's zigzag incision is the most common and preferred approach for surgical access to the flexor tendons in the finger. This incision provides excellent exposure, allows for good visualization of the flexor sheath and tendon, and minimizes the risk of creating a longitudinal scar that could lead to flexion contracture. A midaxial incision is typically used for bony procedures or accessing the neurovascular bundles, not direct flexor tendon repair. Transverse incisions would limit exposure. A straight volar incision is contraindicated due to the high risk of contracture. A dorsal approach is for extensor tendon or dorsal bony injuries.

Question 11

What is the primary role of the A4 pulley in the context of an FDP avulsion injury?





Explanation

The A4 pulley, located over the middle of the distal phalanx, is crucial for maintaining the mechanical advantage of the FDP tendon for DIP joint flexion. Its integrity is important for effective FDP function. The A2 pulley is also very important for FDP mechanics. The A4 pulley does not primarily restrict retraction in Type I injuries (where the tendon often retracts to the palm). The vincula provide blood supply. It is not directly related to preventing a boutonniere deformity (which involves the central slip). It does not prevent FDP subluxation at the MCP joint (which involves the A1 pulley and sagitall bands).

Question 12

A 50-year-old carpenter sustained a Type I Jersey finger 3 days ago. During surgical exploration, the FDP tendon is found to be significantly retracted into the palm. What method is typically employed to retrieve the retracted tendon for repair?





Explanation

Retrieving a significantly retracted FDP tendon (common in Type I injuries) often requires extending the Brunner's incision proximally into the palm to directly visualize and grasp the tendon. Additionally, specialized tendon retrievers can be used to pass through the flexor sheath from the distal incision to ensnare and pull the retracted tendon distally. Using a nerve hook alone may be insufficient for substantial retraction, and 'milking' muscles is not a precise surgical technique for tendon retrieval. Therefore, both extending the incision and using a tendon retriever are common and effective.

Question 13

Which factor is most likely to lead to a poor outcome following primary FDP repair for a Jersey finger?





Explanation

Smoking significantly impairs wound healing and tendon repair due to its vasoconstrictive effects and negative impact on collagen synthesis, making it a strong predictor of poor outcomes and complications like re-rupture and stiffness. Repair within 7 days is associated with better outcomes, especially for Type I. Early active motion protocols are generally favored for improving outcomes. A two-strand core suture is typically considered a less strong repair compared to 4-strand or 6-strand, but its use alone is not the strongest predictor of poor outcome compared to smoking. An associated A2 pulley rupture would be addressed during surgery and may complicate rehab but not necessarily lead to a 'poor outcome' more than smoking.

Question 14

A 30-year-old recreational athlete presents with a Jersey finger of the ring finger. Initial X-rays show no bony avulsion. An MRI is ordered and confirms a complete FDP avulsion, with the tendon retracted to the level of the proximal phalanx, indicating a Type II Leddy and Packer injury. What is the rationale for the slightly less urgent surgical timing compared to a Type I injury?





Explanation

In a Type II Jersey finger, the FDP tendon retracts to the level of the PIP joint or proximal phalanx, but often, one or more vincula tendinum (specifically the vinculum breve to the FDP or vinculum longum to the FDS) remain intact, preserving some blood supply to the tendon. This better vascularity compared to a Type I injury (where the tendon often retracts into the palm and loses its vincula) allows for a slightly less urgent surgical window (up to 2-3 weeks). The A2 pulley does not typically prevent retraction to this extent in a Type II injury, nor does it primarily supply blood. Spontaneous reattachment is rare, and nerve injury is not the distinguishing factor here.

Question 15

Following FDP repair, which of the following is a potential complication specifically associated with avulsion fractures where a large bone fragment is reattached?





Explanation

When a bony avulsion fragment is reattached, particularly if it's large, a potential complication is non-union or malunion of the bony fragment. This can lead to persistent pain, tenderness, or mechanical issues. Lumbrical plus and quadriga effect are related to tendon shortening/tensioning. Swan neck and boutonniere deformities are typically associated with extensor mechanism imbalances or other conditions, not directly with bony fragment reattachment from a Jersey finger, although stiffness can contribute to such deformities over time. Therefore, non-union of the bony fragment is the most direct and specific complication related to reattaching a bone fragment.

Question 16

What is the typical management strategy for a Leddy and Packer Type IV Jersey finger injury?





Explanation

A Leddy and Packer Type IV injury involves an avulsion of a bony fragment from the distal phalanx, but crucially, the FDP tendon has avulsed from this bony fragment and retracted further proximally. The management typically involves reattaching the FDP tendon back to the avulsed bony fragment, and then reattaching the bony fragment to the distal phalanx. This dual repair ensures both tendon and bone healing. Excising the fragment would sacrifice potential bone-to-bone healing and reduce the surface for tendon reattachment. FDP advancement is for tendon-only avulsions with a short gap. Staged reconstruction is for chronic cases or large gaps. Non-operative management is not indicated for this complete rupture.

Question 17

Which of the following is a contraindication to primary flexor digitorum profundus (FDP) repair in a Jersey finger injury?





Explanation

Significant tendon loss or severe tendon degeneration that makes a direct, tension-free repair impossible is a contraindication to primary FDP repair. In such cases, alternative strategies like FDP advancement (if the gap is small) or staged tendon reconstruction are considered. Patient age, involvement of a specific finger (small finger often has poorer outcomes but is still repaired), an associated distal phalanx fracture (often part of Type III, IV, V injuries and addressed concurrently), and mild pre-existing osteoarthritis are generally not absolute contraindications, though they may influence prognosis or rehabilitation.

Question 18

A patient undergoes FDP repair for a Jersey finger. The post-operative protocol involves early active motion. What is the primary rationale behind initiating early active motion protocols for flexor tendon repairs?





Explanation

The primary rationale for early active motion protocols after flexor tendon repair is to promote tendon gliding and prevent the formation of restrictive adhesions within the flexor sheath. Controlled motion helps to maintain the gliding surface between the tendon and the surrounding tissues, which is crucial for achieving a good functional outcome and full range of motion. While it may indirectly help with swelling and muscle atrophy, its main goal is to optimize tendon healing and prevent adhesions, which is a major cause of post-operative stiffness.

Question 19

Which FDP injury is most likely to be successfully managed with FDP advancement alone, without the need for a tendon graft?





Explanation

FDP advancement is a viable option for acute FDP ruptures (typically Type I) where there is minimal tendon retraction (generally less than 1 cm) and the remaining tendon quality is good. It involves shortening the tendon slightly to reattach it to the distal phalanx. For chronic injuries with significant retraction, Type IV injuries, or large gaps, advancement alone is usually insufficient due to excessive tension. Type III involves bony reattachment. Patient age itself doesn't determine feasibility of advancement, but older tendons may have poorer quality. Advancement for gaps over 1 cm often leads to excessive tension, a quadriga effect, or re-rupture.

Question 20

A patient presents with a chronic FDP rupture of the ring finger (6 months post-injury). On examination, he has a noticeable hyperextension of the PIP joint and flexion of the MCP joint of the affected digit when attempting to make a fist. This clinical presentation is consistent with:





Explanation

This describes the lumbrical plus phenomenon. In a chronic FDP rupture, the FDP tendon is slack or absent. When the patient attempts to flex the finger, the lumbrical muscle is put under tension, and its pull on the lateral bands results in paradoxical DIP extension and PIP hyperextension. The MCP joint may flex as the lumbrical also flexes the MCP. Quadriga effect limits flexion of adjacent fingers. Boutonniere is PIP flexion and DIP hyperextension. Swan neck is PIP hyperextension and DIP flexion. Central slip rupture causes boutonniere. The specific pattern of attempted flexion leading to PIP hyperextension and DIP extension is key for lumbrical plus.

Question 21

What anatomical feature of the FDP tendon in the small finger sometimes accounts for poorer outcomes compared to other digits following repair?





Explanation

The small finger FDP tendon is often found to have a consistently smaller diameter and poorer intrinsic quality compared to the other FDP tendons. This smaller caliber and potentially weaker tendon tissue can make repairs more challenging and contribute to a higher rate of re-rupture or less optimal outcomes. While other factors might play a role, the tendon's intrinsic size and quality are specifically cited in literature as a potential reason for poorer small finger outcomes. The FDP tendons of the medial four fingers share a common muscle belly, so it does not have an independent muscle belly in this context.

Question 22

In the Leddy and Packer classification, what distinguishes a Type V injury from a Type III or IV injury?





Explanation

The Leddy and Packer classification was initially I, II, III. Type IV was later added for bony avulsion where the tendon also avulses from the fragment. Type V is a more recent addition and specifically describes an intra-articular fracture of the distal phalanx that is associated with an FDP tendon avulsion. This implies articular involvement that needs specific attention beyond just reattaching a bone fragment. The other options describe features of other types or are incorrect.

Question 23

When assessing for a Jersey finger, what would be the expected finding on a 'modified tabletop test' for a patient with a complete FDP rupture of the ring finger?





Explanation

The modified tabletop test (or cascade test) assesses the resting posture of the fingers. Normally, when the hand is at rest, there is a progressive cascade of flexion from the index to the small finger. With a complete FDP rupture, the affected finger's DIP joint will lose its resting flexion tone and will remain extended or only slightly flexed, disrupting this normal cascade. It would not be in full flexion or hyperextended, nor would all fingers be affected. The PIP joint flexion is controlled by the FDS, so it would typically be normal in an isolated FDP rupture.

Question 24

Which rehabilitation phase typically begins immediately post-operative and aims to prevent adhesions while protecting the repair in a flexor tendon injury?





Explanation

The immediate post-operative phase for flexor tendon repairs typically involves passive protected motion protocols. The goal is to allow controlled, passive movement of the repaired digit within a protective splint (e.g., dorsal blocking splint) to promote tendon gliding and prevent adhesions without putting excessive stress on the repair. Active resistance and unrestricted activity are introduced much later. Delayed mobilization is less common now due to the risk of significant stiffness.

Question 25

During surgical repair of a Jersey finger, care must be taken to preserve the flexor pulley system. Which two pulleys are considered the most critical to maintain for optimal flexor tendon function and to prevent bowstringing?





Explanation

The A2 and A4 pulleys are considered the most critical annular pulleys for maintaining the mechanical efficiency of the flexor tendons and preventing bowstringing. The A2 pulley is located over the proximal phalanx, and the A4 pulley is over the middle of the distal phalanx. Their integrity is paramount for normal finger flexion biomechanics. Damage to these pulleys significantly compromises the tendon's leverage and function.

Question 26

A 32-year-old patient underwent FDP repair for a Type I Jersey finger 4 weeks ago. He is now in the early active motion phase of rehabilitation. He complains of pain and tenderness at the DIP joint with active flexion, but passive range of motion is full. What is the most common concern at this stage?





Explanation

In the early active motion phase (typically starting around 3-4 weeks), pain with active motion combined with full passive range of motion is a common sign of developing adhesions within the flexor sheath. Adhesions restrict the smooth gliding of the tendon, causing pain when the patient attempts to actively move the digit against the resistance of the adhesions. Re-rupture would present with loss of active motion. Persistent swelling and infection would have more generalized symptoms. Improper splint application could cause pressure, but the specific presentation points to adhesions.

Question 27

Which of the following describes the anatomical pathway of the FDP tendon from its muscle belly to its insertion?





Explanation

The Flexor Digitorum Profundus (FDP) muscle originates from the anterior and medial surfaces of the ulna and the interosseous membrane. Its tendons pass through the carpal tunnel deep to the FDS tendons, and each tendon inserts onto the palmar base of the distal phalanx of the four medial fingers (index, long, ring, small). The other options describe incorrect origins, pathways, or insertions.

Question 28

A 45-year-old professional pianist sustains a Jersey finger (Type I) of his long finger. He presents 6 weeks post-injury. What is the most appropriate treatment option at this delayed presentation?





Explanation

At 6 weeks, a Type I Jersey finger is considered a chronic injury. Significant tendon retraction and shortening would have occurred, making direct primary repair or FDP advancement (which is typically for gaps <1cm) impossible without excessive tension leading to quadriga or re-rupture. Therefore, staged tendon reconstruction using a silicone rod followed by a tendon graft is the most appropriate option to reconstruct the flexor mechanism and restore function. Non-operative management will not restore active DIP flexion. Amputation is a last resort.

Question 29

In a patient presenting with an acute Jersey finger, an X-ray is primarily useful for what purpose?





Explanation

Plain radiographs (X-rays) are crucial in the initial evaluation of a Jersey finger to identify the presence and size of any associated avulsion fracture from the palmar aspect of the distal phalanx. This bony fragment helps classify the injury (e.g., Type III, IV, V) and influences treatment urgency and technique. X-rays are not good for assessing soft tissue swelling, confirming tendon tears (clinical exam or MRI better), visualizing retracted tendons (MRI better), or evaluating pulley integrity (MRI or dynamic ultrasound better).

Question 30

What is the typical timeframe within which a Leddy and Packer Type I Jersey finger repair should ideally be performed to achieve the best outcomes and prevent tendon necrosis?





Explanation

A Type I Jersey finger involves the FDP tendon avulsing without a bony fragment and retracting into the palm, often losing its blood supply from the vincula. This puts the tendon at high risk of necrosis. Therefore, surgical repair is considered urgent and should ideally be performed within 7-10 days of injury to maximize the chances of tendon survival and good functional outcome. Delays beyond this window significantly increase the risk of poor healing, tendon shortening, and the need for more complex reconstructive procedures.

Question 31

When reattaching the FDP tendon to the distal phalanx, what is the anatomical landmark for its insertion?





Explanation

The FDP tendon inserts onto the palmar base of the distal phalanx. This is the anatomical location where the tendon typically avulses in a Jersey finger injury, and it is the target for reattachment during surgical repair, whether directly to bone or to a bony fragment. The other options describe incorrect insertion points for the FDP tendon.

Question 32

Which of the following is considered a relative contraindication for primary FDP repair in an acute setting?





Explanation

Significant wound contamination is a relative contraindication to immediate primary flexor tendon repair. Attempting to repair a tendon in a contaminated field dramatically increases the risk of deep infection, which can be devastating to the outcome. In such cases, thorough debridement, antibiotics, and a delayed primary repair or staged reconstruction might be considered after infection control. Associated extensor injury or patient occupation are not contraindications. Patient request for non-operative management is a patient choice, not a contraindication based on injury characteristics. Inability to achieve full passive DIP flexion pre-operatively is unusual in acute FDP rupture and might suggest other pathology.

Question 33

Which of the following statements about FDP advancement in Jersey finger repair is most accurate?





Explanation

FDP advancement involves pulling the FDP tendon distally and reattaching it to the distal phalanx. It is a viable technique for acute FDP ruptures, especially Type I, where the tendon has retracted but the gap is small (typically less than 1 cm), allowing for a tension-free repair. It is generally not suitable for chronic ruptures or large gaps due to the risk of excessive tension leading to a quadriga effect or re-rupture. It does not shorten the FDS, and it is not primarily for Type III injuries (which involve bony reattachment).

Question 34

A patient is recovering from a FDP repair. He develops a 'swan neck deformity,' characterized by PIP hyperextension and DIP flexion. Which of the following is the most likely contributing factor in the context of a healed FDP repair?





Explanation

While swan neck deformity is classically associated with rheumatoid arthritis or other pathologies, it can occur after flexor tendon repair. If there are adhesions limiting the excursion of the FDP tendon, it can lead to a relative laxity of the FDP at the DIP joint. This laxity, combined with the normal pull of the extensor mechanism and potentially the intrinsic muscles, can result in PIP hyperextension and DIP flexion. Re-rupture would present with loss of active DIP flexion. The other options are less directly linked to FDP repair. Over-tightening of the FDS could lead to PIP flexion contracture, not hyperextension.

Question 35

When using a pull-out suture technique for FDP repair, what is the primary purpose of the small button or plate on the dorsal aspect of the fingertip?





Explanation

In the pull-out suture technique, sutures are passed through the repaired FDP tendon, through the distal phalanx, and exit dorsally through the fingertip. A small button or plate is then tied over the dorsal skin or nail, acting as an external anchor. This provides a secure fixation point for the suture, holding the FDP tendon against the distal phalanx until healing occurs. It's a method of securing the repair without needing internal hardware. It doesn't primarily immobilize the joint, protect the nail, or indicate tension.

Question 36

Which of the following factors would most strongly favor consideration of primary arthrodesis of the DIP joint over FDP repair for a Jersey finger injury?





Explanation

Primary arthrodesis of the DIP joint is considered for chronic flexor tendon injuries where tendon reconstruction is deemed unlikely to achieve good results, or in patients with pre-existing severe DIP joint arthritis, especially those with high demand for stable grip (like a heavy manual laborer). For a young, otherwise healthy patient with an acute injury, repair is almost always preferred. A chronic injury beyond 6 months, particularly if associated with significant joint degeneration and high functional demands for stability, can make arthrodesis a more predictable and functional outcome than a complex, multi-stage reconstruction. Early return to sports is not a reason for arthrodesis over repair.

Question 37

What is the primary concern if an FDP repair is performed with excessive tension?





Explanation

Repairing the FDP tendon with excessive tension is a known cause of the quadriga effect. Because the FDP tendons of the medial four fingers share a common muscle belly, overtensioning one FDP tendon can restrict the ability of the adjacent, normally functioning FDP tendons to fully flex their respective DIP joints. This results in limited flexion of the uninjured fingers when the repaired finger attempts to flex fully. The other options are less directly and uniquely linked to excessive tension during FDP repair.

Question 38

A patient with a chronic Jersey finger (Type I, 3 months post-injury) presents with significant FDP tendon retraction and shortening. What surgical strategy, besides staged reconstruction, might be considered if the patient is older and has lower functional demands?





Explanation

For chronic FDP ruptures, especially in older patients with lower functional demands where staged reconstruction might be too extensive, or when direct repair/advancement is impossible, a flexor digitorum superficialis (FDS) tenodesis to the distal phalanx can be considered. This procedure uses one slip of the FDS tendon to provide some active flexion or at least prevent hyperextension at the DIP joint. FDP advancement is for acute small gaps. Primary repair with bone anchor assumes the tendon can be brought to length. EDC transfer is for extensor deficit. Immediate DIP arthrodesis is an option, but FDS tenodesis offers some motion. Therefore, FDS tenodesis is a valid alternative for selected cases.

Question 39

What is the typical clinical finding that differentiates a complete FDP rupture from a partial FDP rupture?





Explanation

A complete FDP rupture results in a complete inability to actively flex the DIP joint of the affected finger. In contrast, a partial FDP rupture would typically present with painful but weak or incomplete active DIP flexion, rather than a total absence of motion. While other findings like ecchymosis or a palpable gap can be present, the key clinical differentiator for degree of rupture lies in the active motion test. The modified tabletop test would be positive (disrupted cascade) in a complete rupture. Bony avulsion classifies the injury type but doesn't differentiate complete vs. partial tear of the tendon substance itself.

Question 40

When surgically repairing a Type I Jersey finger, which maneuver can help achieve a tension-free repair if there is moderate retraction but not enough to necessitate a graft?





Explanation

Hyperflexion of the wrist and MCP joints places the flexor tendon system in a more relaxed position, which can help to gain several millimeters of length and allow for a tension-free repair of a moderately retracted FDP tendon. This is a common intraoperative maneuver. Extensive pulley release can lead to bowstringing. Tenolysis of FDS is generally not necessary or desirable. Sectioning the lumbrical might address a lumbrical plus but won't gain length for the FDP repair itself. Lengthening the FDS is not for FDP repair.

Question 41

A 22-year-old patient presents with a Type III Jersey finger of the index finger. During repair, the bony fragment is securely reattached to the distal phalanx. What is the appropriate post-operative management strategy regarding mobilization?





Explanation

For most flexor tendon repairs, including those involving bony reattachment (like Type III Jersey finger), early protected passive motion with a dorsal blocking splint is the standard of care. This protocol allows for controlled tendon gliding to prevent adhesions while protecting the healing repair. Immediate active motion or active resistance exercises would place too much stress on the repair, risking re-rupture or bone fragment displacement. Rigid immobilization for 6 weeks leads to significant stiffness and adhesions.

Question 42

What is the average ultimate tensile strength of a 4-strand core suture repair of a flexor tendon, a critical consideration for early motion protocols?





Explanation

The average ultimate tensile strength of a 4-strand core suture repair (e.g., Modified Kessler) is generally reported to be in the range of 40-60 Newtons (N). This level of strength is considered sufficient to withstand the forces generated during early protected motion protocols without re-rupture, allowing for the benefits of tendon gliding while maintaining repair integrity. Repairs with fewer strands (2-strand) are weaker, and 6-strand repairs offer more strength.

Question 43

In a case of acute Jersey finger, if an MRI is performed, what is its primary advantage over plain radiographs?





Explanation

MRI offers superior soft tissue resolution, allowing for accurate assessment of the FDP tendon's exact location, the degree of retraction, its quality (e.g., presence of fraying or degeneration), and whether there are associated injuries to the flexor sheath, vincula, or surrounding soft tissues. While X-rays are good for bone, MRI provides detailed information about the tendon itself, which is crucial for surgical planning. MRI is not faster or less expensive than X-ray, and X-rays are generally sufficient for proximal phalanx fractures.

Question 44

Which of the following is an expected long-term complication unique to FDP avulsion injuries involving the small finger?





Explanation

While stiffness can occur in any digit, the small finger FDP avulsion injuries are often associated with a greater propensity for persistent stiffness, less range of motion, and generally poorer functional outcomes compared to other digits, even with technically successful repairs and diligent rehabilitation. This is often attributed to the smaller tendon size, anatomical variations, and potentially higher tension in the small finger unit. Intrinsic tightness, lumbrical plus, and neuromas are not unique to the small finger FDP injury specifically.

Question 45

A 60-year-old patient with an acute Jersey finger (Type I) and a history of poorly controlled diabetes presents for surgical repair. What is the most significant concern regarding his prognosis compared to a healthy individual?





Explanation

Poorly controlled diabetes significantly impairs wound healing due to microvascular disease, neuropathy, and compromised immune function. This leads to a substantially increased risk of surgical site infection, delayed tendon healing, and overall poorer outcomes in flexor tendon repair. While other complications can occur, impaired healing and infection risk are paramount concerns in diabetic patients. The other options are not specifically heightened by diabetes more than by general factors of tendon repair or intrinsic to the injury type.

Question 46

What is the primary goal of using a dorsal blocking splint in the immediate post-operative period after flexor tendon repair?





Explanation

A dorsal blocking splint is designed to prevent active extension of the rehabilitated finger(s) beyond a safe, predetermined limit (typically with the wrist in slight flexion, MCPs in flexion, and IPs near full extension). This position protects the healing flexor tendon repair from excessive tension during early motion and prevents re-rupture, particularly during active extension, which could over-stretch the repair. It does not encourage immediate active flexion, nor does it apply continuous passive motion. It facilitates protected passive flexion and controlled active flexion within its limits.

Question 47

During examination of a suspected Jersey finger, how would you best differentiate an FDP rupture from a central slip rupture?





Explanation

The key differentiation lies in the affected joint and associated deformity. A complete FDP rupture leads to an inability to actively flex the DIP joint. A central slip rupture, by contrast, leads to disruption of the extensor mechanism at the PIP joint, eventually resulting in a boutonniere deformity (PIP joint flexion and compensatory DIP joint hyperextension). FDP involves the DIP, central slip involves PIP mechanics primarily. Palpable gaps are not universally present in FDP ruptures. Both can be diagnosed clinically, though imaging can confirm. Both can be acute.

Question 48

Which of the following describes the anatomical relationship of the FDP tendon relative to the FDS tendon in the finger?





Explanation

In the finger, the FDP tendon lies deep (dorsal) to the FDS tendon until the level of the PIP joint. At the PIP joint, the FDS tendon splits (decussates) into two slips, allowing the FDP tendon to pass through this split to insert onto the distal phalanx. This anatomical relationship is critical for understanding flexor tendon mechanics and surgical approaches.

Question 49

After surgical repair of a Type II Jersey finger, the patient develops a flexion contracture of the PIP joint. What is the most likely cause of this complication?





Explanation

While the FDP was repaired, adhesions can occur between the FDS tendon and its sheath, or between the FDP and FDS, or the FDS to its own sheath. If the FDS tendon develops adhesions, it can limit PIP extension and lead to a flexion contracture of the PIP joint. Re-rupture of the FDP primarily affects DIP flexion. Quadriga effect limits flexion of adjacent fingers. Insufficient mobilization usually leads to global stiffness, but if specifically the FDS is adhered, it creates PIP flexion. Extensor inflammation would more likely cause an extensor lag or pain, not a contracture in flexion of PIP.

Question 50

Which of the following is the most appropriate imaging study to confirm the integrity of the flexor pulley system in a professional athlete after a suspected injury, if clinical examination is equivocal?





Explanation

Dynamic ultrasound is highly effective for assessing the integrity of the flexor pulley system, especially in cases of suspected rupture or injury (e.g., in rock climbers). It allows for real-time visualization of the tendon's position relative to the bone during active finger flexion, which can demonstrate bowstringing if a pulley is torn. MRI can also assess pulleys but is static; dynamic ultrasound provides a functional assessment. X-rays are for bone, CT for complex fractures, bone scan for metabolic activity.

Question 51

A patient sustained a Jersey finger and is unable to undergo surgery for 5 weeks due to systemic illness. The injury is a Type I FDP avulsion of the ring finger. What is the most likely surgical approach to consider given this delayed presentation?





Explanation

At 5 weeks, a Type I Jersey finger is already significantly delayed. The FDP tendon would have retracted considerably and undergone shortening and likely degenerative changes due to loss of blood supply. Primary repair with pull-out sutures or bone anchors would likely be impossible without excessive tension. FDP advancement is for smaller, acute gaps. Therefore, staged tendon reconstruction using a silicone rod to create a pseudosheath, followed by a tendon graft, becomes the most viable option to restore active flexion. DIP joint arthrodesis is a salvage procedure, typically considered after failed repairs or in very specific chronic cases.

Question 52

What is the primary function of the annular pulleys (A1-A5) in the flexor tendon sheath?





Explanation

The primary function of the annular pulleys (A1-A5) is to keep the flexor tendons closely apposed to the phalanges. This prevents 'bowstringing' of the tendons, which would otherwise reduce their mechanical advantage and drastically diminish their efficiency in generating joint flexion. The vincula provide blood supply. The synovial sheath produces fluid and reduces friction. Pulleys are structural, not shock absorbers.

Question 53

Which of the following correctly describes the anatomical relationship of the neurovascular bundles in the fingers relative to the flexor tendons?





Explanation

The digital neurovascular bundles (composed of the digital artery, nerve, and vein) run on the radial and ulnar sides of the flexor tendon sheath and phalanges within the finger. They are located just volar to the sagittal mid-axial line, making them vulnerable during surgical approaches or direct trauma. They do not lie volar or dorsal to the tendons in a consistent manner relative to the entire finger, nor do they intertwine with the tendons. They are not only dorsal.

Question 54

A patient presents with a chronic FDP rupture of the ring finger. He attempts to make a fist, and you observe active hyperextension of the DIP joint. This is known as:





Explanation

This is a classic description of the lumbrical plus phenomenon. In a chronic FDP rupture, the FDP tendon is slack or non-functional. When the patient attempts to flex the finger (activating the FDP muscle belly), the lumbrical muscle is pulled proximally, and its contraction (as it originates from the FDP tendon and inserts into the extensor mechanism) causes paradoxical extension of the DIP joint instead of flexion. This can be seen as active hyperextension of the DIP with attempted grip.

Question 55

What surgical technique for FDP repair involves passing a suture through the distal tendon stump, out through the nail bed, and securing it over a button on the dorsal aspect of the nail?





Explanation

This is the classic description of a pull-out suture technique. It is often used for FDP avulsion repairs, especially when there is minimal bone for direct anchor fixation or when a bony fragment is small. The suture secures the tendon to the distal phalanx by passing through the bone and exiting dorsally, where it is tied over a button to hold the repair in place. The Modified Kessler and M-Tang are core suture techniques for direct tendon-to-tendon repair. Bone anchors are internal fixation devices. FDP advancement is a lengthening procedure.

Question 56

In Leddy and Packer Type III Jersey finger, what is the significance of the bony avulsion fragment regarding tendon blood supply and timing of surgery?





Explanation

In a Type III Jersey finger, the bony avulsion fragment, typically from the distal phalanx, prevents further proximal retraction of the FDP tendon. Crucially, the vincula tendinum often remain attached to this fragment or the tendon itself, preserving the tendon's blood supply. This maintained vascularity allows for a less urgent surgical window, typically up to 3-4 weeks post-injury, without a significant increase in the risk of tendon necrosis or poor outcome, unlike a Type I injury. The fragment is usually reattached.

Question 57

A 28-year-old athlete sustains a Grade 2 partial FDP tear of the long finger. Which of the following is the most appropriate initial management strategy?





Explanation

For Grade 2 partial FDP tears (where there's some active DIP flexion but weakness and pain), non-operative management with a protected active range of motion protocol (often with a dorsal blocking splint to limit full extension) is frequently attempted. The goal is to allow the tendon to heal while preventing stiffness. Surgical repair is typically reserved for complete tears or partial tears that fail conservative management. Arthrodesis is a salvage. Rigid immobilization leads to stiffness. FDP advancement is for complete tears.

Question 58

What is the expected long-term outcome regarding grip strength following a successful FDP repair for a Type I Jersey finger in a young, compliant patient?





Explanation

Following a successful FDP repair in a young, compliant patient, near-normal grip strength can typically be achieved. However, isolated DIP flexion strength, and potentially endurance, may remain slightly reduced compared to the uninjured contralateral digit due to some scarring, stiffness, or slight tendon shortening. Complete restoration is optimistic, but significant permanent reduction is too pessimistic for a successful repair. The FDP is crucial for grip, not fully compensated by FDS. Increased grip strength is not expected.

Question 59

Which type of suture material is generally preferred for core sutures in FDP repair due to its strength and knot security?





Explanation

Non-absorbable monofilament sutures, such as polypropylene (Prolene) or nylon (Ethilon), are generally preferred for core sutures in flexor tendon repairs. They provide excellent tensile strength, maintain their integrity long enough for tendon healing, have good knot security, and their monofilament nature minimizes tissue drag and infection risk. Absorbable sutures do not provide long-term strength. Gut sutures are rapidly absorbed and have low strength. Stainless steel wire is generally not used for core sutures in the hand due to stiffness and potential for fatigue failure or pull-out.

Question 60

When performing an FDP repair, which of the following describes the potential issue of a 'too-tight' repair?





Explanation

A 'too-tight' FDP repair, meaning the tendon is repaired with excessive tension or advanced too much, is a classic cause of the quadriga effect. Because the FDP tendons for the ring, middle, and small fingers share a common muscle belly (and the index finger's FDP is closely related), overtightening one tendon can prevent full excursion of the entire FDP muscle group. This leads to restricted flexion in the adjacent, healthy digits when the repaired finger attempts to flex. Lack of active flexion implies re-rupture or adhesions. Insufficient coaptation leads to gapping. Blood supply issues are from the injury itself.

Question 61

A patient is 6 months post-operative from FDP repair. He has recovered excellent passive range of motion but complains of persistent weakness and fatigue with grip, especially during repetitive tasks. What is the most appropriate next step in his rehabilitation?





Explanation

At 6 months post-op, with good passive range of motion but persistent weakness and fatigue, the patient is ready for a focused progressive strengthening and endurance program. The tendon is well-healed by this point, and the focus shifts from protection and early motion to regaining full strength, power, and endurance for functional activities. Immobilization would lead to further stiffness and deconditioning. Re-rupture would present with loss of active motion. Corticosteroids are not indicated. Immediate unrestricted activity without strengthening may risk re-injury or poor functional return.

Question 62

Which of the following is a common early sign of infection following flexor tendon repair, requiring prompt evaluation?





Explanation

The classic signs of infection (rubor, tumor, dolor, calor - redness, swelling, pain, warmth) are crucial indicators. Increasing pain, erythema, swelling, and warmth around the surgical site, especially if accompanied by fever or purulent drainage, are clear signs of a potential infection and warrant immediate evaluation and treatment. Numbness could be nerve irritation, mild swelling is common post-op, serous drainage without pain is often normal, and limited passive ROM points to stiffness/adhesions, not typically early infection.

Question 63

What is the typical insertion point of the FDS tendon in the finger?





Explanation

The Flexor Digitorum Superficialis (FDS) tendon splits into two slips at the PIP joint, with the FDP passing through this decussation. The two slips of the FDS then re-unite to insert onto the palmar aspect of the middle phalanx of the four medial fingers. The FDP inserts onto the distal phalanx. The volar plate is a ligamentous structure. The dorsal aspect is for extensors. The thumb has its own flexor pollicis longus.

Question 64

Which of the following represents the most challenging FDP avulsion injury to repair primarily, often requiring more complex solutions?





Explanation

A chronic Type I injury with the tendon retracted significantly into the forearm (often many centimeters) is the most challenging for primary repair. Over time, the retracted tendon shortens, undergoes degenerative changes, and dense adhesions form, making it impossible to bring the tendon to the distal phalanx without excessive tension. This scenario almost invariably requires staged tendon reconstruction with a graft, which is a much more complex procedure than repairing acute Type I, II, III, or V injuries. Acute injuries generally have better outcomes with primary repair.

Question 65

When evaluating a patient for a Jersey finger, which finding on physical examination most strongly suggests the FDS tendon is still functional?





Explanation

The Flexor Digitorum Superficialis (FDS) is the primary flexor of the PIP joint. The most definitive test for FDS function is to stabilize the patient's adjacent fingers in full extension (to inactivate the FDP of those fingers, which share a common muscle belly) and then ask the patient to actively flex the PIP joint of the finger being tested. If the PIP joint flexes against resistance, the FDS is functional. Inability to flex the DIP suggests FDP rupture. Intact cascade is an FDP sign. Pain with passive extension is non-specific. Palpable tendon doesn't confirm function.

Question 66

What is the most likely complication if the A2 pulley is inadvertently excised during FDP repair?





Explanation

The A2 pulley, along with the A4 pulley, is considered critical for maintaining the mechanical efficiency of the flexor tendons. Excision or rupture of the A2 pulley leads to 'bowstringing' of the flexor tendon, where the tendon lifts away from the bone during flexion, significantly reducing its mechanical advantage and causing a loss of grip strength and range of motion. Lumbrical plus and quadriga are related to tendon length/tension. Boutonniere involves the extensor mechanism. Chronic pain is a general complication, not specific to A2 excision.

Question 67

Which of the following describes the 'no man's land' zone in flexor tendon surgery?





Explanation

'No man's land' refers to Zone II of the flexor tendon system, which extends from the distal palmar crease to the mid-portion of the middle phalanx. This zone is particularly challenging for flexor tendon repairs due to the close proximity of both FDS and FDP tendons within a confined fibro-osseous sheath, making it highly susceptible to adhesion formation and poor gliding post-repair. While surgical techniques and rehabilitation have improved outcomes, it remains a challenging zone.

Question 68

A patient with a chronic FDP rupture (Type I, 4 months old) of the long finger is undergoing staged tendon reconstruction. What is the primary purpose of inserting a silicone rod (Hunter rod) in the first stage?





Explanation

In staged tendon reconstruction for chronic flexor tendon ruptures, the silicone rod (Hunter rod) is inserted in the first stage. Its primary purpose is to induce the formation of a smooth, well-vascularized pseudosheath (neoligament) around the rod. This pseudosheath then provides a low-friction conduit for the passage of an autogenous tendon graft in a second stage, facilitating its gliding and improving the chances of a functional outcome. It does not provide active flexion, nor is it a permanent prosthesis (unless motion is not desired).

Question 69

When advising a patient on post-operative care following FDP repair, what is the typical recommended duration for avoiding heavy gripping and lifting activities?





Explanation

While light activities and protected active motion begin early, heavy gripping and lifting activities are typically restricted for a period of 3-4 months (12-16 weeks) following flexor tendon repair. This timeframe allows for adequate tensile strength development in the healing tendon. Premature engagement in strenuous activities risks re-rupture. Tendon healing is a slow process, with tensile strength gradually increasing over several months.

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Dr. Mohammed Hutaif
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Prof. Dr. Mohammed Hutaif
Consultant Orthopedic & Spine Surgeon
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