Stiff Finger Joints: Diagnosis and Treatment

Stiff finger joints can significantly impair hand function and lead to substantial disability, making everyday tasks challenging. As noted by Sterling Bunnell, the hand has a tendency to stiffen in positions of nonfunction following injury. This comprehensive guide will explore the diagnosis and treatment of stiff finger joints, drawing from detailed anatomical insights and clinical practices.

Understanding Stiff Finger Joints: Causes and Impact

Stiff finger joints can result from various etiologies, including direct or indirect injury, infection, excessive immobilization, or arthrosis. The initial response to almost any hand or finger injury is edema, where the injured digit is bathed in a macrophage- and protein-rich fluid. This fluid not only affects the injured structure but also surrounds adjacent uninjured tissues, acutely impairing joint function.

Continued edema leads to distention of synovial spaces, effectively shortening capsular structures and collateral ligaments. Eventually, these changes become fixed, resulting in joint contractures. A key aspect of this process involves the metacarpophalangeal (MP) joint.

The Role of Edema and Joint Anatomy in Stiffness

The MP joint's intracapsular fluid capacity is maximized when fully extended. In this position, the MP joint is also at its most unstable, with minimal articular surface contact and lax capsular structures. In contrast, interphalangeal (IP) joint capacity is minimally affected by joint position or hydrostatic edema, though skin tension plays a role. For a normal IP digit, 12 mm of dorsal skin lengthening is needed for 90 degrees of flexion; with just a 5 mm increase in tissue thickness due to edema, 19 mm is required, often impossible due to skin inelasticity. This leads to a characteristic posture of MP joint extension and IP joint flexion, which, if untreated, can cause fixed changes in articular and extra-articular structures.

Anatomical Overview of Finger Joints:

• Metacarpophalangeal (MP) Joint: A multiaxial condyloid joint allowing flexion, extension, abduction, adduction, and slight circumduction. It features a loose capsule, two collateral ligaments, two accessory ligaments, and a volar plate. The shape of the metacarpal head is a cam with a volar flare, which tightens collateral ligaments in flexion, increasing joint stability.
• Proximal Interphalangeal (PIP) Joint: A hinge or ginglymus joint facilitating wide flexion and extension while resisting coronal plane motion. Stability comes from articular geometry, collateral ligaments, and the volar plate. Unlike the MP joint, there's no cam effect, so collateral ligament tension is uniform throughout motion. The PIP volar plate has a distinct fibrocartilaginous distal portion and a thin, membranous proximal portion, with proximal extensions called checkreins or swallowtail ligaments that limit hyperextension.
• Distal Interphalangeal (DIP) Joint: Also a hinge joint. Reinforced laterally by collateral ligaments and accessory ligaments. Its volar plate, unlike the PIP, lacks lateral volar extensions (checkreins), allowing for hyperextension.

Diagnosing Stiff Finger Joints: Comprehensive Examination

Evaluating a stiff finger requires understanding that the hand functions as an organ where all parts affect its overall performance. One stiff finger can compromise the entire hand's function. The initial step is to determine if the limitation of joint movement is fixed or if it varies with adjacent joint positions or muscle activation.

Key Diagnostic Steps:

1. Active vs. Passive Motion Assessment: If passive motion exceeds active motion, the problem is at least partly musculotendinous (motor unit incompetence, adhesion, or both). If active and passive motion are equal, the issue is more likely capsular or due to a bony block.
2. Radiographs and MRI: Radiographs can identify articular incongruity or heterotopic ossification. Three-Tesla MRI offers high-resolution imaging of cartilage and ligament structures, becoming increasingly important in preoperative evaluation.
3. Effect of Adjacent Joints (Seesaw Effect): A nonarticular contracting structure spanning two joints can cause a “seesaw effect,” where flexing one joint allows extension of the other, and vice versa.
4. Bunnell Intrinsic Tightness Test: This test assesses the effect of MP joint position on PIP joint flexion. A positive test (less PIP flexion when the MP joint is held extended than when it's flexed) indicates intrinsic muscle tightness. Symmetric tightness suggests interosseous involvement, while more tightness with ulnar deviation might indicate a lumbrical component.
5. Lumbrical Tightness Test: If the Bunnell test is normal but active finger flexion is limited without passive joint contracture, lumbrical tightness may be present. This is tested by passively flexing both the PIP and DIP joints into a hook grip.
6. Extrinsic Tightness Tests:

• Extensor Tendon Tightness: Flex the wrist and MP joints, then assess passive IP joint flexion. Difficulty in IP flexion suggests extensor adhesions or tightness.
• Flexor Tendon Tightness: Assess IP extension with the wrist and MP joints extended. Less extension indicates extrinsic flexor tightness.

7. Landsmeer Test: Elicits findings of a tight oblique ligament of Landsmeer, which can cause DIP joint extension and PIP joint flexion, similar to a boutonnière deformity.

Nonoperative Interventions for Stiff Finger Joints

Nonoperative treatment combines modalities to reduce edema, rest the injured part, and achieve motion through low-load, prolonged stress. These include active and passive exercise, heat, cold, and splinting.

Types of Splints:

• Static Splints: Maintain hand/digits in one position, supporting healing or confining movement within a range.
• Serial Static Splints: Applied at maximum tissue excursion, then adjusted and reapplied as tissues accommodate.
• Dynamic Splints: Apply elastic traction (springs, rubber bands) to provide load while permitting motion. Ideal when passive motion responds to manual stretch and inflammation has subsided.
• Static Progressive Splints: Similar to dynamic but without motion within the splint, often using three-point force application (e.g., Joint-Jack, Knuckle-Jack splints).

Nonoperative Treatment for MP Joint Extension Contractures

The MP joint's anatomy makes it prone to extension contractures after injury due to edema. Splinting the MP joint in flexion maintains collateral ligament length. Initial treatment involves aggressive edema control, splinting in flexion, and controlled mobilization. If clinical examination and radiographs suggest collateral ligament or capsular fibrosis, splinting with aggressive hand therapy is the first line of treatment. A combination of dynamic daytime and static progressive nighttime splinting is preferred, continuing as long as improvement is observed. While normal MP joints can flex to 90 degrees, 60 degrees of flexion is often functionally sufficient, especially in radial digits.

Nonoperative Treatment for PIP Joint Flexion Contractures

PIP joint flexion contractures can stem from volar skin scars, Dupuytren’s disease, flexor tendon sheath contraction, adherent flexor tendons, retinacular ligament adherence, volar plate contraction, or bony blocks. The most common pathway involves pathology of the volar plate complex and its checkrein expansions. Splinting (dynamic or serial casting) is crucial, applying slow, steady extension force perpendicular to the middle phalanx. Pain indicates excessive load. Static splinting at night maintains daytime gains. Serial casting can also be effective, with casts changed every few days.

Weeks et al. reported success in 87% of PIP joint contractures with active, passive, and resistive exercises alongside dynamic and static splinting.

Operative Release of Contractures: When Nonoperative Fails

Surgical release is indicated when residual joint motion is functionally disabling, articular surfaces are normal, joint motors are intact, and nonoperative modalities have been exhausted. Crucially, it requires a diligent, compliant patient committed to postoperative therapy.

Metacarpophalangeal (MP) Joint Flexion Contractures

When nonoperative measures fail for a stiff MP joint, surgery may be needed. Even with radiographic changes, if the joint remains congruent, good range of motion can often be salvaged. The preferred method is a dorsal approach to release collateral ligaments and perform a capsulotomy.

Surgical Technique (Authors' Preferred Method):

1. Longitudinal dorsal incisions over MP joints.
2. Extensor tendon split, elevated, and reflected with sagittal band.
3. T-shaped incision in dorsal capsule, taking care not to injure articular surfaces.
4. Excision of dorsal capsule and dorsal half of collateral ligaments.
5. Passive flexion tested; if limited, collateral ligaments detached from metacarpal head (often both needed to prevent rotation).
6. Elevator used to free adhesions between volar plate and volar capsule.
7. If MP joint jumps/triggers in full extension, remaining accessory collateral ligament is divided.
8. Extensor tendons examined for excursion and adhesions; tenolysis performed if needed.
9. Extensor tendon incision closed, hand splinted with MP joints at 70 degrees flexion.

Postoperative care involves elevation, followed by custom static (night) and dynamic flexion assist (day) splints, combined with closely monitored therapy for several months. Complications can include ulnar deviation, extensor tendon disruption, or ankylosis if contractures are not adequately released or therapy compliance is poor.

Proximal Interphalangeal (PIP) Joint Flexion Contractures

If conservative measures fail, surgical intervention addresses volar skin contractures (Z-plasties, skin flaps), flexor tendon pathology, and primarily the volar plate and checkrein expansions.

Surgical Approaches:

• Volar Surgical Approach (Bruner incision): Skin flaps elevated, neurovascular bundles protected. Flexor tendon sheath opened, tendons retracted. Checkrein ligaments identified (often near the transverse digital artery) and released. Capsular release and accessory collateral ligament release performed. If contracture persists, collateral ligament detached from proximal phalanx. Active motion tested intraoperatively if local anesthesia with sedation is used.
• Surgical Mid-lateral Approach: Incision from midshaft of proximal to middle phalanx. Neurovascular bundle retracted palmarly. Transverse retinacular ligament divided, accessory collateral ligament and volar plate visualized. Checkrein ligaments released, then capsular release and accessory collateral ligament release. If needed, proper collateral ligament released. This approach has shown more favorable outcomes than the volar Bruner approach.
• TATA (Total Anterior Tenoarthrolysis) Procedure: A mid-axial approach from web space to fingertip. Periosteum elevated from anterior middle and proximal phalanx. Flexor digitorum superficialis insertion released, pulleys intact. PIP joint released laterally, volar plate and accessory collateral ligaments released. DIP joint volar plate and profundus tendon insertion may also need release. Postoperatively, active motion is encouraged, with alternating extension and flexion splints.

Authors' Preferred Treatment (Flexion Contractures):

• Digit Widget: Preferred before open release by one author (A.Y.S.). This device applies extension torque via rubber bands, allowing PIP joint range of motion during treatment. Followed by dynamic and static extension splinting.
• Open Release: Mid-lateral approach preferred. Checkrein ligaments released (sparing digital arteries), then capsular release, accessory collateral ligaments, and if necessary, proper collateral ligament detachment from proximal phalanx.

Proximal Interphalangeal (PIP) Joint Extension Contractures

Surgery is best performed under local anesthesia with sedation to allow intraoperative testing of contracture release. The operative approach can be dorsal or dorsolateral.

Surgical Technique:

1. Extensor mechanism exposed, transverse fibers of retinacular ligament longitudinally divided.
2. Extensor tendon elevated (avoiding central slip insertion).
3. Dorsal capsule excised. Range of motion assessed.
4. If full easy flexion not possible, dorsalmost fibers of collateral ligaments released. If still not obtained, rest of collateral ligaments released off proximal phalanx origin.
5. Patient asked to voluntarily flex digit to check for extrinsic causes.
6. Bunnell's intrinsic tightness test performed; if positive, intrinsic release considered.
7. Lateral bands released, followed by gentle passive flexion maneuvers to break adhesions.

Distal Interphalangeal (DIP) Joint Contractures

DIP joint stiffness is less problematic unless a fixed flexion or hyperextension deformity exists. Treatment of underlying swan neck or boutonnière deformities often resolves stiffness. Fixed extension contractures can be treated by dividing dorsal and lateral extensor tendon fibers. Fixed flexion contractures (e.g., chronic mallet deformities) are best managed by arthrodesis.

Intrinsic Contracture After Trauma

Post-traumatic interosseous contracture typically results from edema, prolonged immobilization, or muscle ischemia. Edema fluid trapped within the interosseous muscle compartment leads to capillary compression and venous stasis. Fibrosis eventually supervenes. This leads to characteristic deformities: flexed MP joints and extended IP joints, often preventing grip.

Late Post-traumatic Intrinsic Contracture of the PIP Joint

Several months after wrist or hand injury, persistent limited PIP flexion can be due to residual intrinsic contracture, even if intra-articular adhesions are suspected. The swollen collateral ligaments resist MP flexion but not PIP extension. The MP joint remains unaffected, but an extension contracture develops at the PIP joint, with a positive intrinsic tightness test. In these cases, only the oblique fibers of the lateral bands are resected (distal intrinsic release).

Technique of Distal Intrinsic Release:

1. Local anesthesia dorsal to proximal phalanx.
2. Longitudinal incision along dorsal midline of distal half of proximal phalanx.
3. Lateral bands, oblique fibers, and central/lateral slips of dorsal aponeurosis identified.
4. Lateral band and oblique fibers resected at distal third of proximal phalanx (central slip, lateral slips, and transverse fibers should not be resected).

Postoperatively, MP joints are splinted in extension for 3 weeks, and active/passive IP flexion exercises begin within one day.

Severe Post-traumatic Intrinsic Contractures with Muscle Fibrosis

For severe cases involving both MP and IP joints, extensive dorsal aponeurosis release is needed. If interossei are fibrotic but retain contractility, a muscle slide can be performed. With more severe ischemia, complete resection of necrotic muscle is necessary. If fingers are flexed at MP joints and extended at IP joints, this suggests interosseous ischemia and necrosis.

Technique of Release for Severe Intrinsic Contractures:

1. Dorsal transverse incision just proximal to MP joints.
2. Resection of lateral tendons of all interossei and abductor digiti quinti at MP joint level.
3. If MP joints remain flexed, sagittal bands retracted, accessory collateral ligaments divided at volar plate insertion.
4. Volar plate freed from proximal phalanx base, adhesions between volar plate and metacarpal head separated.
5. If phalanx extension is difficult, Kirschner wire inserted obliquely through MP joint in maximum extension (ensuring proper articulation).
6. If passive PIP flexion is incomplete with MP joint extended, lateral bands resected at distal half of proximal phalanx through separate dorsal incision.

Postoperatively, passive and active PIP flexion exercises begin within one day, and the Kirschner wire is usually removed at about 3 weeks.

Arthroplasty for the Stiff Joint (Nonrheumatoid)

Arthroplasty is considered for incongruent joints with pain, deformity, or stiffness, especially when the articular surface is destroyed. Alternatives to arthroplasty, like arthrodesis (joint fusion), are considered when bone stock is poor or soft tissue is severely damaged.

Resection Arthroplasty

First reported in 1954 for the PIP joint, this involves resecting the injured joint. While tissue interposition using extensor tendon or volar plate has been described, silicone elastomer spacers are most commonly used today. These stemmed spacers can be applied to all finger joints and have shown good success in low-demand patients, particularly for rheumatoid arthropathy. However, silicone implants have limitations in range of motion and stability, are prone to rotation and lateral deformation, and depend on surrounding soft tissue integrity. Implant fracture and reactive synovitis (silicone synovitis) can occur.

Perichondral resurfacing arthroplasty, using transplanted perichondrium, has been explored for traumatic arthrosis in young adults but has yielded disappointing long-term results.

Total Joint Replacement Arthroplasty (SRA)

Surface Replacement Arthroplasty (SRA) aims to recreate the normal geometric articulation. Advantages include reconstructing an anatomic joint with a virtual center of rotation, allowing rolling and sliding for improved mechanical advantage. Minimal bone resection preserves capsular ligaments. Disadvantages include higher risk for subluxation/dislocation, technical difficulties in tendon balancing, and challenging revisions.

Metacarpophalangeal (MP) Joint Arthroplasty

When MP joint injury causes articular surface destruction or when surgical release and therapy fail to restore functional motion and significant pain persists, arthroplasty can be considered. Three main types are available:

• Silicone Elastomer Implants: Used as hinged spacers after resection arthroplasty, predictable for low-demand patients, but with noted limitations in stability and range of motion.
• Metal and Plastic SRA (Cemented): Designed for cement fixation, currently available under Humanitarian Device Exemption.
• Pyrolytic Carbon Implants (Uncemented): A synthetic material with mechanical properties similar to cortical bone, showing exceptional reliability and no wear debris in long-term studies. It's an attractive alternative for SRA in degenerative or traumatic arthritis.

Surgical Technique (SRA/Pyrocarbon):

1. Preoperative planning with manufacturer templates for component sizing.
2. Longitudinal incision centered over MP joint, extensor tendon split.
3. Dorsal capsule divided to expose joint.
4. Osteotomy of metacarpal head through subchondral bone, distal to collateral ligaments, perpendicular to long axis of metacarpal (angle varies by implant: 45° for Avanta SR MCP, 27.5° for Ascension pyrolytic carbon).
5. 1-2 mm resection of proximal phalanx base.
6. Intramedullary canals broached to appropriate sizes.
7. Trial implants placed to assess range of motion and stability.
8. Implants impacted (or cemented) in place, wound closed.

Proximal Interphalangeal (PIP) Joint Arthroplasty

PIP joint arthroplasty is considered for painful, arthritic joints. While Swanson silicone implants are viable for ring and small finger PIP joints (and sometimes index/long fingers if well-aligned and collateral ligaments are good or in low-demand patients), some caution against their use in index and middle fingers due to significant stress on collateral ligaments during key pinch. Newer SRA and pyrolytic carbon PIP joint systems are also available, with bicondylar anatomic designs and dorsal grooves for the central slip.

Surgical Technique (PIP SRA/Pyrocarbon):

1. Preoperative planning with templates.
2. Generous dorsal linear or curvilinear incision, full-thickness flaps.
3. Extensor mechanism split longitudinally down midline (or Chamay incision for length adjustment).
4. Dorsal capsule incised longitudinally to expose joint.
5. Marginal osteophytes removed from proximal phalanx head and middle phalanx base.
6. Intramedullary canals prepared with awls and broaches.
7. Trial implants placed for range of motion and stability assessment.
8. Implants impacted (or cemented), wound closed. Splinting in full extension for 3 weeks is typically followed by active motion exercises.

Frequently Asked Questions about Stiff Finger Joints

What are the main causes of stiff finger joints?

Stiff finger joints can be caused by injury (direct or indirect), infection, prolonged immobilization, or arthrosis. Often, the body's initial response to injury, edema, plays a significant role in developing contractures.

How does edema contribute to finger stiffness?

Edema, an accumulation of fluid, bathes both injured and uninjured structures in the hand. It distends joint spaces, shortens ligaments, and makes tissues inelastic, especially the dorsal skin, thereby limiting the range of motion and leading to contractures.

What is the Bunnell Intrinsic Tightness Test?

The Bunnell Intrinsic Tightness Test helps diagnose intrinsic muscle tightness. It involves comparing the amount of PIP joint flexion when the MP joint is held extended versus when it is flexed. Less PIP flexion with an extended MP joint indicates intrinsic tightness.

When is surgery recommended for stiff finger joints?

Surgical intervention is considered when nonoperative treatments fail, joint motion is functionally disabling, the articular surface is relatively normal, and the joint motors are intact. Patient compliance with postoperative therapy is also a critical factor for success.

What are the different types of arthroplasty for finger joints?

Arthroplasty options include resection arthroplasty (often using silicone elastomer spacers), surface replacement arthroplasty (SRA) with metal/plastic components, and pyrolytic carbon implants. Each type has specific indications, advantages, and disadvantages depending on the joint and patient needs.