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DIPJ arthritis

Overview

Percutaneous DIP joint arthrodesis offers distinct advantages over open fusion techniques in select patients [1], while lateral approaches with plate fixation provide equivalent results to traditional methods with fewer major complications [5]. For severe painful osteoarthritis involving both the PIP and DIP joints of the same digit, simultaneous surgical intervention is recommended [3]. Motion-preserving alternatives include denervation with cheilectomy [4] or silicone interpositional arthroplasty, which achieves excellent pain relief and a range of movement of 30–40 degrees with a low overall complication rate of 5% [8].

Surgical technique selection depends on specific anatomical requirements and patient factors. The smile incision and reverse shotgun approach is indicated when more volar joint preparation and implant insertion sites are necessary [9], whereas the nonaxial multiple small screws (NMSS) technique is feasible for DIPJ and thumb IPJ arthrodesis, particularly when a small finger is indicated and a significant flexion angle is required [11]. Implant selection should consider cost and complication profiles given the lack of difference in biomechanical performance between K-wires and compression screws [20].

Swan neck deformity progresses significantly over time due to increasing DIPJ flexion contracture [2]. When combining procedures, the combination of DIP arthrodesis and PIP Swanson arthroplasty results in favorable outcomes regarding simultaneous bony union and flexibility [7]. Customized structural bone grafting addresses bone stock loss and medullary absence in failed DIPJ silicone arthroplasty, achieving reliable union rates and high patient satisfaction [13].

Anatomy & Pathophysiology

Osseous Morphology and Stability

The morphology of the distal phalanx presents specific constraints for internal fixation, as a substantial number of distal phalanges are too small to accommodate commonly available headless compression screws, particularly in females and the small finger [31]. Understanding of DIP joint morphology may lend insight into the biomechanics and disease progression within the DIP joints [10]. Regarding articular integrity, palmar subluxation of a DIP joint without preexisting arthritic deformity is expected when more than one half of the dorsal articular surface is injured [6].

Dislocation Biomechanics and Reduction

Irreducibility was more commonly seen in dorsal dislocations of the DIP joint than in volar dislocations [33]. Conversely, volar dislocations of the DIP joint carried a higher risk of instability immediately after reduction compared to dorsal dislocations [33].

Tendon Dynamics and Rehabilitation

Biomechanically, dynamic tenodesis for the DIP joint using the remaining FDP tendon results in a flexion angle greater than 30 degrees [23]. In a cadaveric model, tenodesis successfully restored coordinated interphalangeal joint flexion after a simulated zone I FDP laceration with improvements in DIP joint flexion and composite finger flexion [35]. To facilitate healing, lateral blocking with incremental joint angles allows a safer application of force for the healing tendon during palmar and lateral blocking exercises [26].

Classification

Other Considerations: Swan neck deformity in the DIPJ can progress significantly over time due to increasing DIPJ flexion contracture [2]. Radiological osteoarthritis following a mallet finger fracture follows a natural degenerative process similar to that of the DIP joint [12]. Post-traumatic osteoarthritis of the DIPJ after mallet finger fractures is accompanied by a decrease in range of motion, though this does not clinically affect patient-reported outcome measures (PROMs) [12]. The interrater reliability of the Kellgren & Lawrence and OARSI classification systems for post-traumatic osteoarthritis in the DIPJ after mallet finger fractures is considerably lower than initially assumed [34]. Morphological understanding of DIPJ curvatures may provide insight into the biomechanics and disease progression within the joint [10]. Current concepts regarding DIPJ osteoarthritis examine the roles of cartilage, subchondral bone, and soft tissue structures in etiology, pathogenesis, and evaluation [19]. Examination of type I and type II nerve endings provides new information on the sensory systems of the DIP joints and surrounding structures [32].

Clinical Presentation

The clinical presentation of distal interphalangeal joint (DIPJ) pathology varies by etiology, ranging from progressive deformity to acute instability. In primary osteoarthritis, a Swan neck deformity progresses significantly over time due to increasing DIPJ flexion contracture [2]. The pathophysiology involves complex interactions between cartilage, subchondral bone, and soft tissue structures [19]. Understanding the specific morphology of DIP joints may provide insight into their biomechanics and disease progression [10].

Posttraumatic etiologies present with distinct patterns. Radiological osteoarthritis following a mallet finger fracture follows a similar course to the natural degenerative process in the DIP joint [12]. While this posttraumatic osteoarthritis is accompanied by a decrease in range of motion, it does not clinically affect patient-reported outcome measures (PROMs) [12]. Palmar subluxation of a DIP joint is expected when more than one half of the dorsal articular surface is injured, even without preexisting arthritic deformity [6]. Additionally, floating distal interphalangeal joint injuries can be initially misdiagnosed due to minimal deformity [17], though osteoarthritis may develop following treatment of these chronic injuries [17].

Rare entities require specific diagnostic vigilance. Primary synovial chondromatosis of the DIP joint is an extremely rare entity [27]. Accurate diagnosis is required to distinguish primary synovial chondromatosis of the DIP joint from other arthropathies [27].

Investigations

Plain radiography: Radiological osteoarthritis following a mallet finger fracture mimics the natural degenerative process of the DIP joint and is accompanied by a decreased range of motion, yet it does not clinically affect patient-reported outcome measures [12]. Understanding DIP joint morphology via imaging provides insight into the biomechanics and disease progression of the condition [10]. Current concepts regarding osteoarthritis examine etiology, pathogenesis, and evaluation, highlighting the roles of cartilage, subchondral bone, and soft tissue structures [19]. Palmar subluxation of a DIP joint without preexisting arthritic deformity is expected when more than one half of the dorsal articular surface is injured [6].

Other Considerations: Swan neck deformity progresses significantly over time due to increasing DIPJ flexion contracture [2]. Floating DIP joint injuries can be misdiagnosed initially due to minimal deformity, though open reduction and internal fixation remains a viable treatment option for chronic cases despite the potential development of osteoarthritis [17]. Immobilization of the distal interphalangeal joint of any finger reduces overall grip strength, with the reduction becoming progressively more pronounced from the index to the little fingers [16]. A distinct collagen septum exists between the extensor tendon and skin at the DIP joint [38]. A size mismatch existed between the anatomic dimensions of the DIP joint and commercially available headless compression screws [21].

Treatment

Non-Operative

Splinting of the distal interphalangeal joint reduces pain and improves extension at the joint without giving rise to non-compliance, increased stiffness, or restriction of range of motion [15]. Injection with collagenase Clostridium histolyticum is an option for the treatment of DIP joint contractures in Dupuytren disease, though the potential risk for recurrence should be carefully weighed prior to its use [36].

Operative

Indications: Simultaneous surgical intervention is recommended for severe painful osteoarthritis of the PIP and DIP joints of the same digit [3]. Open DIP joint cheilectomy is a safe and effective alternative to DIP joint arthrodesis in patients with symptomatic osteoarthritis who wish to preserve joint motion [37]. Diabetes and surgeon experience are factors increasing the risk of postoperative complications in DIP/thumb IP joint arthrodeses [14].

Surgical Approach / Technique: Percutaneous DIP joint arthrodesis is advantageous compared with open fusion techniques in select patients [1]. The lateral approach and plate fixation for DIP joint arthrodesis yields results equivalent to traditional methods with fewer major complications [5]. The smile incision and reverse shotgun approach is a good surgical option for DIPJ arthrodesis when more volar part joint preparation and more volar implant insertion sites are necessary [9]. The nonaxial multiple small screws (NMSS) technique is a feasible option for DIPJ and thumb IPJ arthrodesis, especially when a small finger is indicated and a significant flexion angle is required [11]. Open reduction and internal fixation is a viable treatment option for chronic floating DIP joint injuries, though osteoarthritis may develop [17].

Implant Selection: Silicone interpositional arthroplasty of the DIP joint is an acceptable alternative to arthrodesis, achieving excellent pain relief and a range of movement of 30–40 degrees with a low overall complication rate of 5% [8]. Customized structural bone grafting addresses bone stock loss and medullary absence in failed DIPJ silicone arthroplasty, achieving reliable union rates and high patient satisfaction [13].

Adjuncts: The combination of DIP arthrodesis and PIP Swanson arthroplasty resulted in a favourable outcome in terms of simultaneous bony union and flexibility [7]. Denervation with cheilectomy presents a motion-preserving alternative to arthrodesis for symptomatic DIP joint osteoarthritis [4].

Complications

Instability: Palmar subluxation of the DIP joint is expected when more than one half of the dorsal articular surface is injured in the absence of preexisting arthritic deformity [6]. Additionally, Swan neck deformity in the DIPJ progresses significantly over time due to increasing DIPJ flexion contracture [2].

Stiffness / Arthrofibrosis: Radiological osteoarthritis following a mallet finger fracture follows a natural degenerative process and is accompanied by a decrease in DIPJ range of motion, though it does not clinically affect patient-reported outcome measures [12].

General Arthrodesis Complications: Arthrodesis of the distal interphangeal joint often leads to complications [18]. Diabetes is a factor that increases the risk of postoperative complications in DIP and thumb IP joint arthrodeses [14]. Surgeon experience is a factor that increases the risk of postoperative complications in DIP and thumb IP joint arthrodeses [14].

Other Considerations: Silicone interpositional arthroplasty of the DIP joint has a low overall complication rate of 5% [8]. Salvage of failed Swanson's arthroplasty addresses issues of bone stock loss and medullary absence, achieving reliable union rates and high patient satisfaction [13].

Recovery

Light activity (weeks): Splinting of the DIP joint reduces pain and improves extension at the joint without causing non-compliance, increased stiffness, or restriction of range of motion [15]. Percutaneous DIP joint arthrodesis offers advantages over open fusion techniques in select patients [1], while lateral approach and plate fixation yields results equivalent to traditional methods with fewer major complications [5].

Full activity (months): Silicone interpositional arthroplasty achieves a range of movement of 30–40 degrees with excellent pain relief [8]. The combination of DIP arthrodesis and PIP Swanson arthroplasty results in favorable outcomes regarding simultaneous bony union and flexibility [7]. Simultaneous surgical intervention is recommended for severe painful osteoarthritis of both the PIP and DIP joints of the same digit [3].

Complete recovery / outcome plateau (months): Radiological osteoarthritis following a mallet finger fracture is similar to the natural degenerative process in the DIP joint [12]. While this condition is accompanied by a decrease in range of motion, the decrease does not clinically affect PROMs [12]. Swan neck deformity progresses significantly over time due to increasing DIPJ flexion contracture [2].

Rehabilitation protocol: Denervation with cheilectomy presents a motion-preserving alternative to arthrodesis for symptomatic DIP joint osteoarthritis [4]. Palmar subluxation of a DIP joint without preexisting arthritic deformity is expected when more than one half of the dorsal articular surface is injured [6]. Customized structural bone grafting addresses bone stock loss and medullary absence in failed DIPJ silicone arthroplasty, achieving reliable union rates and high patient satisfaction [13].

Functional milestones: Silicone interpositional arthroplasty of the DIP joint has a low overall complication rate of 5% [8]. Diabetes is a factor increasing the risk of postoperative complications in DIP and thumb IP joint arthrodeses [14]. Surgeon experience is a factor increasing the risk of postoperative complications in DIP and thumb IP joint arthrodeses [14].

Key Evidence

  • [L4] In select patients, this percutaneous DIP joint arthrodesis is advantageous in comparison with open fusion techniques. (10.1007/s11552-010-9265-9)
  • [L5] The swan neck deformity in this individual progressed significantly with time because of increasing DIPJ flexion contracture. (10.1016/j.jht.2009.11.005)
  • [L3] The authors recommend simultaneous surgical intervention in case of severe painful OA of the PIP and DIP joints of the same digit. (10.1177/17531934231191255)
  • [L4] It presents a compelling motion-preserving alternative to arthrodesis for symptomatic DIP joint osteoarthritis. (10.1016/j.jhsa.2026.01.027)
  • [L4] The results obtained in this small series are equivalent to the traditional methods of DIP joint arthrodesis but with fewer major complications. (10.1016/j.jhsa.2007.09.004)
  • [L5] Palmar subluxation of a DIP joint without preexisting arthritic deformity is expected when more than one half of the dorsal articular surface is injured. (10.1016/j.jhsa.2007.09.006)
  • [L4] The combination of DIP arthrodesis and PIP Swanson arthroplasty resulted in a favourable outcome in terms of simultaneous bony union and flexibility. (10.1177/17531934231215790)
  • [L4] The study confirms that silicone interpositional arthroplasty of the DIP joint is an acceptable alternative to arthrodesis, achieving excellent pain relief and a range of movement of 30–40 degrees with a low overall complication rate of 5%. (10.1177/1753193411422679)
  • [L4] This technique may be a good surgical option for DIPJ arthrodesis when more volar part joint preparation and more volar implant insertion sites are necessary. (10.1186/s12891-024-08016-6)
  • [L5] Our understanding of morphology may lend insight into the biomechanics and disease progression within the DIP joints. (10.1007/s11552-014-9605-2)
  • [L4] Thus, the NMSS technique could be used as a feasible option in DIPJ and thumb IPJ arthrodesis, especially when a small finger is indicated and a significant flexion angle is required. (10.1186/s12891-022-05473-9)
  • [L4] Radiological OA after an MFF is similar to the natural degenerative process in the DIP joint and is accompanied by a decrease in range of motion of the DIP joint, which does not clinically affect PROMs. (10.1016/j.jhsa.2023.03.027)
  • [L4] A customized structural bone graft using the described technique addresses issues of bone stock loss and medullary absence in failed DIPJ silicone arthroplasty, achieving reliable union rates and high patient satisfaction. (10.1177/17531934231151217)
  • [L3] Diabetes and surgeon experience were identified as factors increasing the risk of postoperative complications in these DIP/thumb IP joint arthrodeses. (10.1186/s12891-024-07361-w)
  • [L2] It does not give rise to non-compliance, increased stiffness or restriction of range of motion. (10.1016/j.jht.2013.08.004)
  • [L4] Immobilization of the distal interphalangeal joint of any finger reduces the overall grip strength of the hand, with the effect becoming progressively more pronounced from the index to the little fingers. (10.1177/1753193418765068)
  • [Case_report] Floating DIP joint injuries can be misdiagnosed initially due to minimal deformity; open reduction and internal fixation is a viable treatment option for chronic cases, though osteoarthritis may develop. (10.1016/j.jhsa.2010.05.025)
  • [L3] Arthrodesis of the distal interphalangeal joint often leads to complications. (10.1177/17531934221111641)
  • [L5] This current concepts article examines the recent knowledge base regarding the etiology, pathogenesis, and evaluation of osteoarthritis of the distal interphalangeal joint, highlighting the roles of cartilage, subchondral bone, and soft tissue structures. (10.1016/j.jhsa.2010.09.003)
  • [L5] Given the lack of difference in biomechanical performance between K-wires and compression screws, consideration should be given to other factors such as cost and complication profiles when choosing an implant for DIPJ fusion. (10.1177/1558944715627211)
  • [L4] A size mismatch existed between the anatomic dimensions of the DIP joint and commercially available headless compression screws. (10.1016/j.jhsa.2014.02.007)
  • [L5] Biomechanically, dynamic tenodesis for the DIP joint using the remaining FDP tendon is a valuable procedure because it results in a flexion angle greater than 30 degrees. (10.1016/j.jhsg.2020.08.007)
  • [L5] This study supports the concept that lateral blocking with incremental joint angles allows a safer application of force for the healing tendon. (10.1016/j.jht.2020.07.004)
  • [Case_report] Primary synovial chondromatosis of the distal interphalangeal joint is an extremely rare entity that requires accurate diagnosis to distinguish from other arthropathies. (10.1177/15589447211049520)
  • [L4] A substantial number of distal phalanges are too small to accommodate commonly available headless compression screws, particularly in females and the small finger. (10.1007/s11552-014-9679-x)
  • [L5] Our examination of the distribution of type I and type II nerve endings provides new information on the sensory systems of the DIP joints and surrounding structures. (10.1016/j.jhsa.2010.11.050)
  • [L4] Irreducibility was more commonly seen in dorsal than in volar dislocations, while volar dislocations carried a higher risk of instability immediately after reduction. (10.1177/1753193415616957)
  • [L4] The interrater reliability of the Kellgren & Lawrence and OARSI classification systems for post-traumatic osteoarthritis in the distal interphalangeal joint after mallet finger fractures is considerably lower than initially assumed. (10.1016/j.jhsa.2024.03.012)
  • [L5] In this cadaveric model, this tenodesis successfully restored coordinated interphalangeal joint flexion after a simulated zone I FDP laceration with improvements in distal interphalangeal joint flexion and composite finger flexion. (10.1016/j.jhsa.2013.10.009)
  • [L4] Injection with CCH is an option for the treatment of DIP joint contractures in Dupuytren disease, though the potential risk for recurrence should be carefully weighed prior to its use. (10.1016/j.jhsa.2018.07.004)
  • [L4] Open DIP joint cheilectomy is a safe and effective alternative to DIP joint arthrodesis in patients with symptomatic osteoarthritis who wish to preserve joint motion. (10.1016/j.jhsa.2017.07.006)
  • [L5] We confirmed the existence of a distinct collagen septum between the extensor tendon and skin at the DIP joint using MRI and histology. (10.1016/j.jhsa.2008.11.030)

See Also

References

[1] Treatment of Symptomatic Distal Interphalangeal Joint Arthritis with Percutaneous Arthrodesis: A Novel Technique in Select Patients. HAND. 2010. DOI: 10.1007/s11552-010-9265-9

[2] Swan Neck Deformity after Distal Interphalangeal Joint Flexion Contractures: A Biomechanical Analysis. Journal of Hand Therapy. 2010. DOI: 10.1016/j.jht.2009.11.005

[3] Does distal interphalangeal joint arthrodesis affect proximal interphalangeal joint arthroplasty outcomes in the same finger?. Journal of Hand Surgery (European Volume). 2023. DOI: 10.1177/17531934231191255

[4] Denervation with Cheilectomy of the Distal Interphalangeal Joint: Technique and Medium-Term Results. The Journal of Hand Surgery. 2026. DOI: 10.1016/j.jhsa.2026.01.027

[5] Alternative to the Distal Interphalangeal Joint Arthrodesis: Lateral Approach and Plate Fixation. The Journal of Hand Surgery. 2008. DOI: 10.1016/j.jhsa.2007.09.004

[6] A Biomechanical Study of Distal Interphalangeal Joint Subluxation After Mallet Fracture Injury. The Journal of Hand Surgery. 2008. DOI: 10.1016/j.jhsa.2007.09.006

[7] Simultaneous anterograde screw arthrodesis of distal interphalangeal joint and silastic proximal interphalangeal joint replacement for osteoarthritis. Journal of Hand Surgery (European Volume). 2023. DOI: 10.1177/17531934231215790

[8] Joint replacement in 131 painful osteoarthritic and post-traumatic distal interphalangeal joints. Journal of Hand Surgery (European Volume). 2011. DOI: 10.1177/1753193411422679

[9] Smile incision and reverse shotgun approach in distal interphalangeal joint arthrodesis. BMC Musculoskeletal Disorders. 2024. DOI: 10.1186/s12891-024-08016-6

[10] Curvatures of the DIP Joints of the Hand. HAND. 2014. DOI: 10.1007/s11552-014-9605-2

[11] Distal interphalangeal joint arthrodesis with nonaxial multiple small screws: a biomechanical analysis with axial headless compression screw and clinical result of 15 consecutive cases. BMC Musculoskeletal Disorders. 2022. DOI: 10.1186/s12891-022-05473-9

[12] Posttraumatic Osteoarthritis of the Distal Interphalangeal Joint: A Follow-Up Study of 12 Years After Nonsurgical Treatment of Mallet Finger Fractures. The Journal of Hand Surgery. 2023. DOI: 10.1016/j.jhsa.2023.03.027

[13] Salvage of failed Swanson’s arthroplasty of the distal interphalangeal joint. Journal of Hand Surgery (European Volume). 2023. DOI: 10.1177/17531934231151217

[14] Arthrodesis of distal interphalangeal and thumb interphalangeal joint: a retrospective cohort study of 149 cases. BMC Musculoskeletal Disorders. 2024. DOI: 10.1186/s12891-024-07361-w

[15] Splinting of the Distal Interphalangeal Joint Reduces Pain and Improves Extension at the Joint; Results Front the Splint-OA Study. Journal of Hand Therapy. 2014. DOI: 10.1016/j.jht.2013.08.004

[16] Effect of immobilization of the distal interphalangeal joint of fingers on grip strength. Journal of Hand Surgery (European Volume). 2018. DOI: 10.1177/1753193418765068

[17] Floating Distal Interphalangeal Joint Injury: Case Report. The Journal of Hand Surgery. 2010. DOI: 10.1016/j.jhsa.2010.05.025

[18] Risk factors in distal interphalangeal joint arthrodesis in the hand: a retrospective study of 173 cases. Journal of Hand Surgery (European Volume). 2022. DOI: 10.1177/17531934221111641

[19] Osteoarthritis of the Distal Interphalangeal Joint. The Journal of Hand Surgery. 2010. DOI: 10.1016/j.jhsa.2010.09.003

[20] Biomechanical Analysis of Internal Fixation Methods for Distal Interphalangeal Joint Arthrodesis. HAND. 2016. DOI: 10.1177/1558944715627211

[21] Distal Interphalangeal Joint Bony Dimensions Related to Headless Compression Screw Sizes. The Journal of Hand Surgery. 2014. DOI: 10.1016/j.jhsa.2014.02.007

[23] The Effect of Flexor Digitorum Profundus Dynamic Tenodesis on the Distal Interphalangeal Joint: A Cadaver Study. Journal of Hand Surgery Global Online. 2020. DOI: 10.1016/j.jhsg.2020.08.007

[26] Tensile load on the flexor digitorum profundus tendon during palmar and lateral blocking exercises: Influence on blocking force and distal interphalangeal joint flexion angle. Journal of Hand Therapy. 2021. DOI: 10.1016/j.jht.2020.07.004

[27] Primary Distal Interphalangeal Joint Tenosynovial Chondromatosis of the Small Finger: A Case Report With Literature Review. HAND. 2022. DOI: 10.1177/15589447211049520

[31] Dimensional Analysis of the Distal Phalanx with Consideration of Distal Interphalangeal Joint Arthrodesis Using a Headless Compression Screw. HAND. 2014. DOI: 10.1007/s11552-014-9679-x

[32] Distribution of Nerve Endings in Human Distal Interphalangeal Joint and Surrounding Structures. The Journal of Hand Surgery. 2011. DOI: 10.1016/j.jhsa.2010.11.050

[33] Differences between dorsal and volar dislocations of the distal interphalangeal joint of fingers: a report of 30 cases. Journal of Hand Surgery (European Volume). 2016. DOI: 10.1177/1753193415616957

[34] Rater Agreement of Post-Traumatic Osteoarthritis of the Distal Interphalangeal Joint 12 Years After a Mallet Finger Fracture. The Journal of Hand Surgery. 2024. DOI: 10.1016/j.jhsa.2024.03.012

[35] Tenodesis for Restoration of Distal Interphalangeal Joint Flexion in Unrepairable Flexor Digitorum Profundus Injuries. The Journal of Hand Surgery. 2014. DOI: 10.1016/j.jhsa.2013.10.009

[36] Collagenase Clostridium histolyticum for the Treatment of Distal Interphalangeal Joint Contractures in Dupuytren Disease. The Journal of Hand Surgery. 2019. DOI: 10.1016/j.jhsa.2018.07.004

[37] Cheilectomy for Treatment of Symptomatic Distal Interphalangeal Joint Osteoarthritis: A Review of 78 Patients. The Journal of Hand Surgery. 2017. DOI: 10.1016/j.jhsa.2017.07.006

[38] Dorsal Digital Septum of the Distal Interphalangeal Joint. The Journal of Hand Surgery. 2009. DOI: 10.1016/j.jhsa.2008.11.030

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1. If You Share the Licensed Material (including in modified form), You must:

a. retain the following if it is supplied by the Licensor with the Licensed Material:

i. identification of the creator(s) of the Licensed Material and any others designated to receive attribution, in any reasonable manner requested by the Licensor (including by pseudonym if designated);

ii. a copyright notice;

iii. a notice that refers to this Public License;

iv. a notice that refers to the disclaimer of warranties;

v. a URI or hyperlink to the Licensed Material to the extent reasonably practicable;

b. indicate if You modified the Licensed Material and retain an indication of any previous modifications; and

c. indicate the Licensed Material is licensed under this Public License, and include the text of, or the URI or hyperlink to, this Public License.

2. You may satisfy the conditions in Section 3(a)(1) in any reasonable manner based on the medium, means, and context in which You Share the Licensed Material. For example, it may be reasonable to satisfy the conditions by providing a URI or hyperlink to a resource that includes the required information.

3. If requested by the Licensor, You must remove any of the information required by Section 3(a)(1)(A) to the extent reasonably practicable.

4. If You Share Adapted Material You produce, the Adapter's License You apply must not prevent recipients of the Adapted Material from complying with this Public License.

Section 4 -- Sui Generis Database Rights.

Where the Licensed Rights include Sui Generis Database Rights that apply to Your use of the Licensed Material:

a. for the avoidance of doubt, Section 2(a)(1) grants You the right to extract, reuse, reproduce, and Share all or a substantial portion of the contents of the database for NonCommercial purposes only;

b. if You include all or a substantial portion of the database contents in a database in which You have Sui Generis Database Rights, then the database in which You have Sui Generis Database Rights (but not its individual contents) is Adapted Material; and

c. You must comply with the conditions in Section 3(a) if You Share all or a substantial portion of the contents of the database.

For the avoidance of doubt, this Section 4 supplements and does not replace Your obligations under this Public License where the Licensed Rights include other Copyright and Similar Rights.

Section 5 -- Disclaimer of Warranties and Limitation of Liability.

a. UNLESS OTHERWISE SEPARATELY UNDERTAKEN BY THE LICENSOR, TO THE EXTENT POSSIBLE, THE LICENSOR OFFERS THE LICENSED MATERIAL AS-IS AND AS-AVAILABLE, AND MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND CONCERNING THE LICENSED MATERIAL, WHETHER EXPRESS, IMPLIED, STATUTORY, OR OTHER. THIS INCLUDES, WITHOUT LIMITATION, WARRANTIES OF TITLE, MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT, ABSENCE OF LATENT OR OTHER DEFECTS, ACCURACY, OR THE PRESENCE OR ABSENCE OF ERRORS, WHETHER OR NOT KNOWN OR DISCOVERABLE. WHERE DISCLAIMERS OF WARRANTIES ARE NOT ALLOWED IN FULL OR IN PART, THIS DISCLAIMER MAY NOT APPLY TO YOU.

b. TO THE EXTENT POSSIBLE, IN NO EVENT WILL THE LICENSOR BE LIABLE TO YOU ON ANY LEGAL THEORY (INCLUDING, WITHOUT LIMITATION, NEGLIGENCE) OR OTHERWISE FOR ANY DIRECT, SPECIAL, INDIRECT, INCIDENTAL, CONSEQUENTIAL, PUNITIVE, EXEMPLARY, OR OTHER LOSSES, COSTS, EXPENSES, OR DAMAGES ARISING OUT OF THIS PUBLIC LICENSE OR USE OF THE LICENSED MATERIAL, EVEN IF THE LICENSOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH LOSSES, COSTS, EXPENSES, OR DAMAGES. WHERE A LIMITATION OF LIABILITY IS NOT ALLOWED IN FULL OR IN PART, THIS LIMITATION MAY NOT APPLY TO YOU.

c. The disclaimer of warranties and limitation of liability provided above shall be interpreted in a manner that, to the extent possible, most closely approximates an absolute disclaimer and waiver of all liability.

Section 6 -- Term and Termination.

a. This Public License applies for the term of the Copyright and Similar Rights licensed here. However, if You fail to comply with this Public License, then Your rights under this Public License terminate automatically.

b. Where Your right to use the Licensed Material has terminated under Section 6(a), it reinstates:

1. automatically as of the date the violation is cured, provided it is cured within 30 days of Your discovery of the violation; or

2. upon express reinstatement by the Licensor.

For the avoidance of doubt, this Section 6(b) does not affect any right the Licensor may have to seek remedies for Your violations of this Public License.

c. For the avoidance of doubt, the Licensor may also offer the Licensed Material under separate terms or conditions or stop distributing the Licensed Material at any time; however, doing so will not terminate this Public License.

d. Sections 1, 5, 6, 7, and 8 survive termination of this Public License.

Section 7 -- Other Terms and Conditions.

a. The Licensor shall not be bound by any additional or different terms or conditions communicated by You unless expressly agreed.

b. Any arrangements, understandings, or agreements regarding the Licensed Material not stated herein are separate from and independent of the terms and conditions of this Public License.

Section 8 -- Interpretation.

a. For the avoidance of doubt, this Public License does not, and shall not be interpreted to, reduce, limit, restrict, or impose conditions on any use of the Licensed Material that could lawfully be made without permission under this Public License.

b. To the extent possible, if any provision of this Public License is deemed unenforceable, it shall be automatically reformed to the minimum extent necessary to make it enforceable. If the provision cannot be reformed, it shall be severed from this Public License without affecting the enforceability of the remaining terms and conditions.

c. No term or condition of this Public License will be waived and no failure to comply consented to unless expressly agreed to by the Licensor.

d. Nothing in this Public License constitutes or may be interpreted as a limitation upon, or waiver of, any privileges and immunities that apply to the Licensor or You, including from the legal processes of any jurisdiction or authority.

Creative Commons is not a party to its public licenses. Notwithstanding, Creative Commons may elect to apply one of its public licenses to material it publishes and in those instances will be considered the “Licensor.” The text of the Creative Commons public licenses is dedicated to the public domain under the CC0 Public Domain Dedication. Except for the limited purpose of indicating that material is shared under a Creative Commons public license or as otherwise permitted by the Creative Commons policies published at creativecommons.org/policies, Creative Commons does not authorize the use of the trademark "Creative Commons" or any other trademark or logo of Creative Commons without its prior written consent including, without limitation, in connection with any unauthorized modifications to any of its public licenses or any other arrangements, understandings, or agreements concerning use of licensed material. For the avoidance of doubt, this paragraph does not form part of the public licenses.

Creative Commons may be contacted at creativecommons.org.