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Thumb Metacarpophalangeal Joint Volar Plate Injury

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Top Contributors - Maryellen Tighe, PT, DPT, Alexandra Stead and Caroline Stone


Introduction

The metacarpophalangeal (MCP) joint is essential for bearing most of the stress that the thumb goes through[1]. The volar plate is the palmar stabilising factor at the thumb MCP joint[2]. There are volar plates at other interphalangeal (IP) joints, however, due to anatomical differences and differences in mobility at the MCP joint, this article focuses only on the volar plate at the MCP joint of the thumb.

Clinically Relevant Anatomy

Anatomy of the thumb MCP joint. Illustrations depicting: A. Coronal and sagittal views of the relevant supporting structures at the thumb MCP joint including volar plate complex, consisting of the phalangoglenoid and checkrein ligaments. B. Transverse illustration at the level of the MCP joint shows important static stabilizers, along with key dynamic stabilizers: the extensor pollicis longus and brevis, flexor pollicis longus, flexor pollicis brevis, and abductor pollicis brevis. The adductor aponeurosis overlies the UCL.
Anatomy of the thumb MCP joint and supporting structures. The left illustration is a coronal view and the right illustration is a sagittal view. The images capture supporting structures, including the Volar Plate, Radial Collateral Ligament and Ulnar Collateral Ligament, and dynamic stabilisers, including the extensor pollicis longus and brevis, flexor pollicis longus, flexor pollicis brevis, and abductor pollicis brevis. Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved[3].

The volar plate of the thumb MCP joint is a membranous end of the palmar ligament, which blends with the volar capsule and attaches to the head of the metacarpal bone[2]. It has two sesamoid bones which are attached by fibres that run transversely to the long axis of the thumb. They blend with the fibres of the Radial Collateral Ligament (RCL) and the Ulnar Collateral Ligament (UCL)[4], which run longitudinally.

There are also volar plates at each finger’s interphalangeal joints. The thumb lacks some of the fibrocartilaginous structure that provides stability in proximal interphalangeal joints; this stability is instead provided by sesamoid bones[4][2]. This creates the potential for different complications in thumb injuries, such as a fracture of the sesamoid bones, than in injuries of other volar plates. This also gives the volar plate additional names, such as the transverse intersesamoid fibers or the intersesamoid ligament[5].

Function

The volar plate is a stabilising ligament of the thumb MCP joint. It works with the UCL and RCL to reinforce the joint capsule and enhance joint stability. The volar plate limits hyperextension[2] while the UCL limits abduction and the RCL limits adduction[3][4]. The volar plate is loose when the MCP is in flexion and tight when the MCP is extended[2].

Injuries to the volar plate at the MCP result in reduced pinch and grasp power[2][1], which further decreases with chronicity[2].  The hyperextension allowed by a volar plate injury increases pain with hand use[1].

Mechanism of Injury / Pathological Process

Injuries most often occur in the proximal end of the ligament[2], where it is more membranous at its attachment to the metacarpal bone, rather than the distal end of the ligament, where it is more fibrous in its attachment to the proximal phalanx. Thumb MCP volar plate injuries may be caused by hyperextension or a severe direct blow to the thumb[2]. These injuries can occur with RCL and UCL injuries[4].

Clinical Presentation

There may be hyperextension[2] and tenderness to palpation on the palmar or volar side of the thumb during examination. There may be some tenderness on the dorsal aspect of the MCP joint as well since repeated hyperextension may cause impingement[2].

Stavropoulos describes an abduction-collapse sign in which the patient is asked to maximally abduct the thumb and index finger against resistance from the opposite hand. A positive sign is indicated by pain and collapse of the MCP joint[2].

Cosmetically these injuries may also appear as a Swan-Neck Deformity[2], as combined MCP hyperextension and IP flexion gives this appearance.

Diagnostic Procedures

A. The T2-weighted coronal image shows the ulnar collateral ligaments (empty arrows) and the closely apposed, superficial aponeurosis of the adductor pollicis longus (empty arrowheads). A similar spatial relationship exists with the radial collateral ligament (arrows) and the superficial tendon of the abductor pollicis brevis (arrowheads).B. The T2-weighted axial image depicts the main collateral ligaments (empty arrows), accessory collateral ligament (arrowhead), aponeurosis of the adductor pollicis longus (empty arrowhead), tendon of the abductor pollicis brevis (curved arrow), intersesamoid ligament (asterisk), and flexor pollicis longus tendon (thin arrow).
A. The T2-weighted coronal image shows the ulnar collateral ligaments (empty arrows) and the closely apposed, superficial aponeurosis of the adductor pollicis longus (empty arrowheads). A similar spatial relationship exists with the radial collateral ligament (arrows) and the superficial tendon of the abductor pollicis brevis (arrowheads).B. The T2-weighted axial image depicts the main collateral ligaments (empty arrows), accessory collateral ligament (arrowhead), aponeurosis of the adductor pollicis longus (empty arrowhead), tendon of the abductor pollicis brevis (curved arrow), intersesamoid ligament (asterisk), and flexor pollicis longus tendon (thin arrow)[6].

Clinical assessment of volar plate injuries is important as MRI results are not sensitive enough to consistently diagnose these injuries[7], especially after the acute phase of the injury[2]. A positive test on an MRI would include high signal intensity, however, the intermediate or striated MRI signal intensity can result as a false positive[1]. A volar plate injury may occur with an avulsion fracture, which may be seen on a plain radiograph, ultrasound or MRI, however, it may occur without an avulsion fracture as well[2]. Ultrasound imaging is particularly useful in confirmed tears, providing additional detail about the fibrocartilaginous structure and associated swelling[2]. Ultrasound is limited to assessment of one structure at a time, which reduces its utility in compound injuries[1].

Differential Diagnosis

When determining a volar plate injury in the thumb, it is important to be mindful that due to its anatomy it can easily involve UCL and RCL fibres, resulting in injuries to those ligaments[4]. It can also be missed in  a diagnosis of an MCP dislocation[8].

Instability without a tear can come from rheumatoid arthritis[1].

In the paediatric population, as bones are relatively weak compared to ligaments and soft tissues, a Salter Harris fracture through the epiphyseal growth plate is more likely[2].

Outcome Measures

The Disabilities of the Arm, Shoulder, and Hand and Michigan Hand Outcomes Questionnaire have been used to measure functional outcomes in studies of thumb MCP volar plate repair.[9]  However, other questionnaires related to the hand may also be useful depending on the patient’s goals.

Management / Interventions

The first course of treatment should be an extension blocking splint for three to six weeks before progressing to passive and active range of motion[2]. If conservative measures fail to reduce the pain, surgical intervention may be appropriate[2].

Conservative interventions:

Where a volar plate avulsion fracture remains stable (i.e., MCP hyperextension range is equal to the uninjured side), immediate active movement may be appropriate[10]. However, delayed diagnosis beyond three weeks reduces the suitability of this approach[10].

Physical therapy focused on range of motion, stiffness prevention and grip strength is the most important in this population[7].

Conservative protocols also vary by institution and provider, but often include up to 3 weeks in a splint[11].

Some suggested exercises for a finger while it is in a splint and as soon as possible after injury:

  1. The patient should move their finger through the full ROM allowed by the splint to limit swelling and improve range of motion[11].    
  2. The patient should move their finger with the top portion of the splint unattached or move the finger with the bottom portion of the splint unattached to promote improved but limited movement[11].        

Surgical

The treatment options available for volar plate injury include capsulodesis, sesamoid arthrodesis, tenodesis with palmaris longus, or extensor pollicis brevis tendons and thermal shrinkage of the volar plate via thumb MCP joint arthroscopy[2]. Biomechanical analysis of outcomes show inferior results for the volar plate reconstruction or repair surgeries, however, there are a wide variety of techniques to address the limitations listed above[2]. There is some case study-level research indicating that the flexor digitorum superficialis tenodesis is a safer, more reproducible procedure[2].

Post-surgery

Protocols vary post-surgically. According to one protocol the thumb should be immobilised for 3 weeks with a splint[2]. After the splint is removed, a physical therapy protocol of 10 sessions starting with passive and progressing to active thumb flexion and extension exercises can be initiated[2].                    

Prognosis

Generally volar plate injuries heal well, however, when they are not moved regularly early on they can cause increased stiffness[11]. The patient may return to everyday activities to their pain tolerance with a splint on[11]. A return to sport should be delayed until the finger is healed and pain has resolved[11], and physical or contact sports should wait for 6 weeks[12]. A return to work and driving may occur when the patient feels that they are able to do tasks without limitations[11].

A suggested conservative rehabilitation time scale is[13]:

Time since injury Suggested interventions
Weeks 0-3 Maintain splinting and exercises the fingers and the hand through its full available range of motion. Avoid increased pressure or high impact activities to allow healing.
Weeks 3-6 Increase activity as allowed by the patient's pain tolerance. Continue to work to reach full range of motion.
Weeks 6-12 Continue to progress the activities of the prior 6 weeks. Healing should occur around 12 weeks with a return to all activities at this time. Swelling and pain may continue however, the pain should not be severe.

Summary

The volar plate, with the MCL and UCL, is one of three main stabilisers at the MCP joint of the thumb. It can be acutely injured with hyper extension or an axial load, and may be injured with the other thumb stabilisers. Early intervention includes bracing and range of motion based exercises should be preformed with the goal of reducing stiffness.

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Schuurman AH, Bos KE. Treatment of Volar Instability of the Metacarpophalangeal Joint of the Thumb by Volar Capsulodesis. Journal of Hand Surgery. 1993;18(3):346-349.
  2. ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 2.14 2.15 2.16 2.17 2.18 2.19 2.20 2.21 2.22 2.23 Stavropoulos T, Giannatos V, Papathanidis V, Roumeliotis R, Koutas K, Kokkalis Z. Surgical Treatment of a Neglected Thumb Volar Plate Injury in an 11-Year-Old Girl: A Case Report. American Journal of Case Reports. 2023 8;24:e940411
  3. ↑ 3.0 3.1 Knisely B, Noland SS, Melville DM. Ultrasound versus MRI in the evaluation of the thumb metacarpophalangeal joint. Journal of Ultrasonography. 2023 Nov 23;23(95):e214-e222.
  4. ↑ 4.0 4.1 4.2 4.3 4.4 Tan S et al. Histology of the volar plate of the thumb metacarpophalangeal joint. Hand Surgery and Rehabilitation. 2023;42:141-146
  5. ↑ Manneck S, Del Grande F, Hirschmann A. Ulnar collateral ligament injuries of the first metacarpophalangeal joint: prevalence of associated injuries on radiographs and MRI. Skeletal Radiol. 2021 Mar;50(3):505-513.
  6. ↑ Lee KY, Rim J, Choi JA, Khil EK. High-Resolution Finger MRI: What Should You Look for in Trauma of the Fingers? J Korean Soc Radiol. 2023 Sep;84(5):1031-1046.
  7. ↑ 7.0 7.1 Shin Y-E, Kim S-J, Kim J-S, Kwak K-Y, Kim J-H, Kim J-P. Efficiency of magnetic resonance imaging for diagnosing unstable ligament injuries around the thumb metacarpophalangeal joint: A comparison to arthroscopy. Journal of Orthopaedic Surgery. 2020;28.
  8. ↑ Kaushik R et al. Neglected volar dislocation of the thumb metacarpophalangeal joint: A case report with review of literature. Annales de Chirurgie Plastique Esthétique. 2026.
  9. ↑ Byung-Sung Kim B-S, Yoon H-G, Park K-H, Kim C-G, Song H-S. Sesamoidectomy and volar plate repair using suture anchor for hyperextension injury of the metacarpophangeal joint of the thumb. Hand Surgery. 2012;18.
  10. ↑ 10.0 10.1 Gaine W, Beardsmore J, Fahmy N. Early active mobilisation of volar plate avulsion fractures. Injury. 1998;29:589-591
  11. ↑ 11.0 11.1 11.2 11.3 11.4 11.5 11.6 The British Society for Surgery of the Hand. Volar Plate Injury. Available from: https://www.bssh.ac.uk/patients/conditions/1021/volar_plate_injury#Treatment_of_a_volar_plate_injury (accessed 18/May/2026)
  12. ↑ NHS Cambridge University Hospitals. Volar plate injury. Available from: https://www.cuh.nhs.uk/patient-information/volar-plate-injury/ (accessed 18/May/2026)
  13. ↑ NHS Lanarkshire. Volar Plate Injury. Available from: https://www.nhslanarkshire.scot.nhs.uk/patient-information-leaflets/hand-therapy/pil-volplt-21-06473-l/ (accessed 18/May/2026)
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