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Ulnar-Sided Wrist Pain and Ulnar Impaction

Ulnar impaction / ulnocarpal abutment and ulnar-shortening osteotomy (corpus-synthesised).

Overview

Ulnar impaction syndrome is increasingly managed with arthroscopic decompression, while ulnar shortening osteotomy and open wafer resection remain established surgical options [1]. Surgical intervention is indicated when nonoperative treatment fails [2]. Primary surgical strategies focus on decreasing ulnocarpal load through either ulnar-shortening osteotomy or partial resection of the distal dome of the ulna [2]. Ulnar shortening osteotomy is a viable option for treating ulnar impaction syndrome regardless of the distal radioulnar joint angle [3]. In cases of ulnar impaction following distal radius malunions, ulnar shortening osteotomy offers a simpler procedure with shorter tourniquet time compared to distal radius corrective osteotomy [4].

Comparative retrospective studies indicate that the wafer procedure and ulnar shortening osteotomy achieve similar clinical and radiologic outcomes, including patient satisfaction, motion, grip strength, and pain relief [5, 28]. However, the wafer procedure is associated with fewer complications [28]. Long-term outcomes for ulnar shortening osteotomy in idiopathic ulnar impaction syndrome remain satisfactory for at least 5 years, despite the development of osteoarthritic changes in the distal radioulnar joint [11].

A systematic approach to evaluating patients with ulnar-sided wrist pain is imperative, as other causes such as triquetrohamate, hamato-lunate, and triquetro-hamate impaction syndromes are underreported and often unrecognized [6, 9]. These impaction syndromes are potentially treatable with satisfactory results once identified [9]. In the context of distal radial fractures treated by plate fixation, the incidence of ulnar-sided wrist pain decreased significantly over time, with only 2.1% of patients experiencing pain at 12 months [12]. For neglected paediatric distal radial epiphyseal injuries with ulnar impaction syndrome, a single-stage inverted dome radial osteotomy and ulnar shortening procedure effectively corrects ulnar variance to neutral, achieving anatomical restoration and improvements in range of motion, grip strength, and pain reduction [15].

Anatomy & Pathophysiology

Ulnar-sided wrist pain is a common cause of upper-extremity disability [8, 14]. The differential diagnosis is complex [8, 14], and determining the etiology is often challenging due to overlapping history and physical examination findings [16]. A systematic approach to evaluating patients with ulnar-sided wrist pain is imperative [10]. Diagnosis requires a detailed history, systematic physical examination with provocative maneuvers, and appropriate diagnostic imaging [16]. Pediatric ulnar-sided wrist pain requires a methodical, anatomic approach to diagnosis and treatment, accounting for skeletal immaturity and potential syndromes [17]. In athletes, this pain is a common problem often resulting from a combination of overuse and acute injury [22]. Effective diagnosis and treatment in athletes requires careful understanding of sport-specific injuries and underlying biomechanics [22].

Overview of Entities

The diagnosis and imaging of ulnar-sided wrist pain involve discussing anatomy, pathophysiology, and radiographic appearance of common entities including TFCC tears, DRUJ disorders, and ECU tendon disorders [24]. Higher rates of distal radioulnar joint arthritis and extensor carpi ulnaris pathology were observed in patients with TFCC tears undergoing repair compared with age- and sex-matched controls without ulnar-sided wrist pain [26]. Further evaluation of direct multi-slice CT arthrography of the wrist in a larger patient population would be promising for depicting the triangular fibro-cartilage in patients with ulnar-sided wrist pain [21].

Kinematics and Osseous Morphology

Ulnar variance increased linearly with incremental axial loading in an axial compression test using fresh-frozen cadavers [23]. Under incremental axial loading, the ulna shifted distally and radially while the lunate moved proximally and ulnarly, suggesting impingement under load [23]. The slope of the ulnar head is more strongly correlated with changes in the closest joint space in the distal radioulnar joint than that of the sigmoid notch in patients with idiopathic ulnar impaction syndrome [25].

Classification

Ulnar-Sided Wrist Pain: This condition is a common cause of upper-extremity disability with a complex differential diagnosis [8, 14]. A systematic approach to evaluating patients is imperative [10]. Pediatric cases require a methodical, anatomic approach that accounts for skeletal immaturity and potential syndromes [17]. The incidence of ulnar-sided wrist pain in distal radial fractures treated by plate fixation decreased significantly over time, with only 2.1% of patients experiencing pain at 12 months [12].

Triquetrohamate Impaction Syndrome: This is an underreported and often unrecognized cause of ulnar-sided wrist pain [6]. It is potentially treatable with satisfactory results once identified [9].

Hamato-lunate and Triquetro-hamate Impaction Syndromes: These are poorly recognized and underdiagnosed causes of refractory ulnar-sided wrist pain [9]. They are potentially treatable with satisfactory results once identified [9].

Idiopathic Ulnar Impaction Syndrome: A large ulnar coverage ratio (UCR), representing the broad base of the lunate, is positively associated with the development of this syndrome [18].

Surgical Management Classification: When nonoperative treatment fails, primary surgical options to decrease ulnocarpal load include ulnar shortening osteotomy (USO) and partial resection of the distal dome of the ulna (wafer procedure) [2]. Ulnar impaction syndrome can be treated with arthroscopic decompression [1]. Arthroscopic treatment with triangular fibrocartilage complex debridement and arthroscopic ulnar wafer resection is an effective treatment for ulnar impaction syndrome [20]. Ulnar shortening osteotomy is a good option to treat patients with ulnar impaction syndrome regardless of the distal radioulnar joint angle [3]. Ulnar shortening osteotomy is a simpler procedure with a shorter tourniquet time compared to distal radius corrective osteotomy for ulnar impaction syndrome after distal radius malunions [4]. The wafer procedure and ulnar shortening osteotomy achieve similar clinical and radiologic outcomes for idiopathic ulnar impaction syndrome [5].

Clinical Presentation

Ulnar-sided wrist pain is a common cause of upper-extremity disability [8, 14] and presents with a complex differential diagnosis [8, 14]. Determining the etiology is often challenging due to overlapping history and physical examination findings [16]. A systematic approach to evaluating these patients is imperative [10]. Diagnosis requires a detailed history, systematic physical examination with provocative maneuvers, and appropriate diagnostic imaging [16].

Specific impaction syndromes are frequently underreported or unrecognized causes of ulnar-sided wrist pain. Triquetrohamate impaction syndrome is often missed [6]. Hamato-lunate and triquetro-hamate impaction syndromes are poorly recognized and underdiagnosed causes of refractory ulnar-sided wrist pain [9]. However, these conditions are potentially treatable with satisfactory results once identified [9].

Etiologic factors and demographic considerations influence presentation. A large ulnar coverage ratio (UCR), representing the broad base of the lunate, is positively associated with the development of idiopathic ulnar impaction syndrome [18]. In pediatric patients, ulnar-sided wrist pain requires a methodical, anatomic approach to diagnosis and treatment that accounts for skeletal immaturity and potential syndromes [17].

Post-traumatic presentation varies over time. The incidence of ulnar-sided wrist pain in patients with distal radial fractures treated by plate fixation decreased significantly with time, with only 2.1% of patients experiencing pain at 12 months [12].

Investigations

Ulnar-sided wrist pain is a common cause of upper-extremity disability with a complex differential diagnosis [8, 14]. Determining the etiology is often challenging due to overlapping history and physical examination findings [16]. A systematic approach to evaluating patients is imperative [10]. Diagnosis requires a detailed history, systematic physical examination with provocative maneuvers, and appropriate diagnostic imaging [16]. Pediatric ulnar-sided wrist pain requires a methodical, anatomic approach to diagnosis and treatment, accounting for skeletal immaturity and potential syndromes [17].

Plain radiography: Standard imaging is essential for initial evaluation, though specific radiographic signs for impaction syndromes are not detailed in the current evidence base.

MRI: Magnetic resonance imaging is part of the appropriate diagnostic imaging required for diagnosis [16].

CT: Direct multi-slice CT arthrography of the wrist is a promising method for depicting the triangular fibro-cartilage in patients with ulnar-sided wrist pain [21].

Other Considerations: Triquetrohamate impaction syndrome is an underreported and often unrecognized cause of ulnar-sided wrist pain [6]. Hamato-lunate and triquetro-hamate impaction syndromes are poorly recognized and underdiagnosed causes of refractory ulnar-sided wrist pain [9]. These syndromes are potentially treatable with satisfactory results once identified [9]. A large ulnar coverage ratio (UCR), representing the broad base of the lunate, is positively associated with the development of idiopathic ulnar impaction syndrome [18].

Treatment

Non-Operative

Surgery is indicated if nonoperative treatment fails [2].

Operative

Indications: Primary surgical options for ulnar impaction syndrome include ulnar-shortening osteotomy or partial resection of the distal dome of the ulna to decrease ulnocarpal load [2]. Effective treatment for ulnar impaction syndrome increasingly relies on arthroscopic decompression [1]. Ulnar shortening osteotomy and open wafer resection remain options for ulnar impaction syndrome [1].

Surgical Approach / Technique: Ulnar shortening osteotomy is a good option to treat patients with ulnar impaction syndrome regardless of the distal radioulnar joint angle [3]. The wafer procedure and ulnar shortening osteotomy for idiopathic ulnar impaction syndrome achieve similar clinical outcomes [5]. The wafer procedure and ulnar shortening osteotomy for idiopathic ulnar impaction syndrome achieve similar radiologic outcomes [5]. Ulnar shortening osteotomy is a simpler procedure with a shorter tourniquet time compared to distal radius corrective osteotomy for ulnar impaction syndrome after distal radius malunions [4]. Ulnar shortening osteotomy can be an attractive alternative to distal radius corrective osteotomy for ulnar impaction syndrome after distal radius malunions [4].

Adjuncts: Ulnar shortening osteotomy combined with arthroscopic débridement of the triangular fibrocartilage complex is effective for treating ulnar impaction syndrome [19]. Arthroscopic treatment with triangular fibrocartilage complex debridement and arthroscopic ulnar wafer resection is an effective treatment for ulnar impaction syndrome [20].

Other Considerations: Wrist function recovered after an initial decrease from week 8 onward in patients undergoing ulnar shortening with the UOL for positive ulnar variance [7]. Clinical outcomes are satisfactory for more than 5 years after ulnar shortening osteotomy for treating idiopathic ulnar impaction syndrome despite the presence of distal radioulnar joint osteoarthritic changes [11]. Triquetrohamate impaction syndrome is an underreported and often unrecognized cause of ulnar-sided wrist pain [6].

The incidence of ulnar-sided wrist pain decreased significantly with time after surgery in patients with distal radial fractures treated by plate fixation [12]. Only 2.1% of patients experienced ulnar-sided wrist pain at 12 months after surgery for distal radial fractures treated by plate fixation [12]. A single-stage procedure of inverted dome radial osteotomy and ulnar shortening effectively corrected ulnar variance to a neutral position in neglected paediatric distal radial epiphyseal injury with ulnar impaction syndrome [15]. The single-stage procedure of inverted dome radial osteotomy and ulnar shortening achieved anatomical restoration in neglected paediatric distal radial epiphyseal injury with ulnar impaction syndrome [15]. The single-stage procedure of inverted dome radial osteotomy and ulnar shortening improved range of motion in neglected paediatric distal radial epiphyseal injury with ulnar impaction syndrome [15]. The single-stage procedure of inverted dome radial osteotomy and ulnar shortening improved grip strength in neglected paediatric distal radial epiphyseal injury with ulnar impaction syndrome [15]. The single-stage procedure of inverted dome radial osteotomy and ulnar shortening reduced pain in neglected paediatric distal radial epiphyseal injury with ulnar impaction syndrome [15].

Complications

Ulnar-sided wrist pain: This condition is a common cause of upper-extremity disability [8]. Determining its etiology is often challenging due to overlapping history and physical examination findings [16]. Specific etiologies include triquetrohamate impaction syndrome, which is an underreported and often unrecognized cause of ulnar-sided wrist pain [6]. Additionally, hamato-lunate and triquetro-hamate impaction syndromes are poorly recognized and underdiagnosed causes of refractory ulnar-sided wrist pain [9]. In the context of distal radial fractures treated by plate fixation, the incidence of ulnar-sided wrist pain decreased significantly with time after surgery, with only 2.1% of patients experiencing pain at 12 months [12].

Recovery

Light activity (weeks): Wrist function typically recovers after an initial decrease from week 8 onward in patients undergoing ulnar shortening with the UOL [7].

Full activity (months): Clinical outcomes remain satisfactory for more than 5 years after ulnar shortening osteotomy for idiopathic ulnar impaction syndrome, despite the presence of distal radioulnar joint osteoarthritic changes [11].

Complete recovery / outcome plateau (months): Radiocarpal congruity progressively reverses after ulnar shortening osteotomy for idiopathic ulnar impaction syndrome, and this reversal of radiographic changes correlates with clinical improvements [30].

Rehabilitation protocol: Ulnar shortening osteotomy is a simpler procedure with a shorter tourniquet time than distal radius corrective osteotomy for ulnar impaction syndrome after distal radius malunions [4]. The wafer procedure and ulnar shortening osteotomy for idiopathic ulnar impaction syndrome achieve similar clinical and radiologic outcomes [5]. Ulnar shortening osteotomy is a good option to treat patients with ulnar impaction syndrome regardless of the distal radioulnar joint angle [3].

Functional milestones: The incidence of ulnar-sided wrist pain decreased significantly with time after surgery in patients with distal radial fractures treated by plate fixation, with only 2.1% of patients experiencing pain at 12 months [12]. A single-stage inverted dome radial osteotomy and ulnar shortening effectively corrected ulnar variance to a neutral position in neglected paediatric distal radial epiphyseal injury with ulnar impaction syndrome, achieving anatomical restoration and improvements in range of motion, grip strength, and pain reduction [15].

Key Evidence

  • [L5] Effective treatment for ulnar impaction syndrome increasingly relies on arthroscopic decompression, though ulnar shortening osteotomy and open wafer resection remain options. (10.1016/j.hcl.2005.08.011)
  • [Paper] Surgery is indicated if nonoperative treatment fails, with the primary options being ulnar-shortening osteotomy or partial resection of the distal dome of the ulna to decrease ulnocarpal load. (10.1016/j.hcl.2010.05.011)
  • [L4] Ulnar shortening osteotomy is a good option to treat patients with ulnar impaction syndrome regardless of the distal radioulnar joint angle. (10.1177/17531934241262931)
  • [L3] USO is a simpler procedure with a shorter tourniquet time that can be an attractive alternative to DRO for ulnar impaction syndrome after distal radius malunions. (10.1177/1558944716685831)
  • [L1] The WP and USO for idiopathic ulnar impaction syndrome achieve similar clinical and radiologic outcomes. (10.1016/j.jhsa.2022.08.029)
  • [L4] Triquetrohamate impaction syndrome remains an underreported and often unrecognized cause of ulnar-sided wrist pain. (10.1177/1558944716670138)
  • [L4] In ulnar shortening with the UOL, wrist function recovered after an initial decrease from week 8 onward. (10.1177/1558944717702465)
  • [L5] Ulnar-sided wrist pain is a common cause of upper-extremity disability with a complex differential diagnosis. (10.1016/j.jhsa.2008.08.026)
  • [L5] Hamato-lunate and triquetro-hamate impaction syndromes are potentially treatable with satisfactory results once identified, though they are poorly recognized and underdiagnosed causes of refractory ulnar-sided wrist pain. (10.1016/j.jhsa.2024.07.016)
  • [L4] A systematic approach to evaluating patients with ulnar-sided wrist pain is imperative. (10.1016/j.jhsa.2014.07.004)
  • [L4] The clinical outcomes are satisfactory for even more than 5 years after ulnar shortening osteotomy for treating idiopathic ulnar impaction syndrome despite the osteoarthritic changes of the DRUJ. (10.4055/cios.2011.3.4.295)
  • [L4] The incidence of ulnar-sided wrist pain decreased significantly with time after surgery, with only 2.1% of patients experiencing pain at 12 months. (10.1177/1753193416630525)
  • [L5] Ulnar-sided wrist pain is a common cause of upper extremity disability with a complex differential diagnosis. (10.1016/j.jhsa.2012.04.036)
  • [L5] The single-stage procedure effectively corrected ulnar variance to a neutral position, achieving anatomical restoration and improvements in range of motion, grip strength, and pain reduction. (10.1177/17531934241307501)
  • [L5] Determining the etiology of ulnar-sided wrist pain is often challenging due to overlapping history and physical examination findings; a detailed history, systematic physical examination with provocative maneuvers, and appropriate diagnostic imaging are essential for diagnosis. (10.5435/jaaos-d-16-00407)
  • [L5] Pediatric ulnar-sided wrist pain requires a methodical, anatomic approach to diagnosis and treatment, accounting for skeletal immaturity and potential syndromes. (10.5435/jaaos-d-21-01029)
  • [L3] A large ulnar coverage ratio (UCR), which represents the broad base of the lunate, was positively associated with the development of idiopathic ulnar impaction syndrome. (10.1302/0301-620x.99b11.bjj-2016-1238.r2)
  • [L4] Ulnar shortening osteotomy combined with arthroscopic débridement of the TFCC is effective for treating ulnar impaction syndrome. (10.1097/blo.0b013e31815a9e21)
  • [L5] Arthroscopic treatment with triangular fibrocartilage complex debridement and arthroscopic ulnar wafer resection is an effective treatment for ulnar impaction syndrome. (10.1016/j.jhsa.2008.07.014)
  • [L4] Further evaluation of direct multi-slice CT arthrography of the wrist in a larger patient population would be promising. (10.1007/s00330-008-1118-3)
  • [L5] Ulnar-sided wrist pain in athletes is a common problem often resulting from a combination of overuse and acute injury, requiring careful understanding of sport-specific injuries and underlying biomechanics for effective diagnosis and treatment. (10.1016/j.csm.2019.12.008)
  • [L5] Ulnar variance increased linearly with incremental axial loading, and the ulna shifted distally and radially while the lunate moved proximally and ulnarly, suggesting impingement under load. (10.1016/j.jhsa.2026.02.032)
  • [L5] The article provides a concise approach to the diagnosis and imaging of ulnar-sided wrist pain, discussing anatomy, pathophysiology, and radiographic appearance of common entities including TFCC tears, DRUJ disorders, and ECU tendon disorders. (10.1016/j.csm.2006.02.008)
  • [L4] The slope of the ulnar head is more strongly correlated with changes in the closest joint space in the distal radioulnar joint than that of the sigmoid notch. (10.1177/1753193419828330)
  • [L3] We observed higher rates of distal radioulnar joint arthritis and extensor carpi ulnaris pathology in patients with TFCC tears undergoing repair compared with age- and sex-matched controls. (10.1177/1558944720937369)
  • [L4] Retrospective studies comparing ulnar shortening osteotomy and the wafer procedure found similar patient satisfaction, motion, grip strength, and pain relief, but fewer complications using the wafer procedure. (10.1016/j.jhsa.2009.12.035)
  • [L4] The RCC progressively reversed after ulnar shortening osteotomy, and this reversal of radiographic changes correlated with clinical improvements. (10.1016/j.jhsa.2012.02.038)

References

[1] Ulnar Impaction Syndrome. Hand Clinics. 2005. DOI: 10.1016/j.hcl.2005.08.011

[2] Ulnar Impaction. Hand Clinics. 2010. DOI: 10.1016/j.hcl.2010.05.011

[3] Does the distal radioulnar joint orientation influence the outcome of ulnar shortening osteotomy: a retrospective study. Journal of Hand Surgery (European Volume). 2024. DOI: 10.1177/17531934241262931

[4] Ulnar Shortening Versus Distal Radius Corrective Osteotomy in the Management of Ulnar Impaction After Distal Radius Malunion. HAND. 2017. DOI: 10.1177/1558944716685831

[5] Ulnar Shortening Osteotomy Versus the Wafer Procedure in the Treatment of Idiopathic Ulnar Impaction Syndrome: A Systematic Review and Meta-Analysis. The Journal of Hand Surgery. 2024. DOI: 10.1016/j.jhsa.2022.08.029

[6] Triquetrohamate Impaction Syndrome: An Unrecognized Cause of Ulnar-Sided Wrist Pain; Its Presentation Further Defined. HAND. 2016. DOI: 10.1177/1558944716670138

[7] Time-Dependent Recovery of Outcome Parameters in Ulnar Shortening for Positive Ulnar Variance: A Prospective Case Series. HAND. 2017. DOI: 10.1177/1558944717702465

[8] Ulnar-Sided Wrist Pain: Evaluation and Treatment of Triangular Fibrocartilage Complex Tears, Ulnocarpal Impaction Syndrome, and Lunotriquetral Ligament Tears. The Journal of Hand Surgery. 2008. DOI: 10.1016/j.jhsa.2008.08.026

[9] Midcarpal Impaction Syndromes as a Rare Cause of Ulnar-Sided Wrist Pain: A Review. The Journal of Hand Surgery. 2024. DOI: 10.1016/j.jhsa.2024.07.016

[10] Examination of the Wrist: Ulnar-Sided Wrist Pain Due to Ligamentous Injury. The Journal of Hand Surgery. 2014. DOI: 10.1016/j.jhsa.2014.07.004

[11] Long-term Outcomes of Ulnar Shortening Osteotomy for Idiopathic Ulnar Impaction Syndrome: At Least 5-Years Follow-up. Clinics in Orthopedic Surgery. 2011. DOI: 10.4055/cios.2011.3.4.295

[12] Natural history and factors associated with ulnar-sided wrist pain in distal radial fractures treated by plate fixation. Journal of Hand Surgery (European Volume). 2016. DOI: 10.1177/1753193416630525

[14] Ulnar-sided Wrist Pain: Evaluation and Treatment of Triangular Fibrocartilage Complex Tears, Ulnocarpal Impaction Syndrome, and Lunotriquetral Ligament Tears. The Journal of Hand Surgery. 2012. DOI: 10.1016/j.jhsa.2012.04.036

[15] Inverted dome radial osteotomy and ulnar shortening for neglected paediatric distal radial epiphyseal injury with ulnar impaction syndrome. Journal of Hand Surgery (European Volume). 2024. DOI: 10.1177/17531934241307501

[16] Evaluation of Ulnar-sided Wrist Pain. Journal of the American Academy of Orthopaedic Surgeons. 2017. DOI: 10.5435/jaaos-d-16-00407

[17] Pediatric Ulnar-sided Wrist Pain: A Review of the Current Literature. Journal of the American Academy of Orthopaedic Surgeons. 2022. DOI: 10.5435/jaaos-d-21-01029

[18] Lunate morphology as a risk factor of idiopathic ulnar impaction syndrome. The Bone & Joint Journal. 2017. DOI: 10.1302/0301-620x.99b11.bjj-2016-1238.r2

[19] Factors Affecting Results of Ulnar Shortening for Ulnar Impaction Syndrome. Clinical Orthopaedics & Related Research. 2007. DOI: 10.1097/blo.0b013e31815a9e21

[20] Arthroscopic Treatment of Ulnar Impaction Syndrome. The Journal of Hand Surgery. 2008. DOI: 10.1016/j.jhsa.2008.07.014

[21] Depiction of the triangular fibro-cartilage in patients with ulnar-sided wrist pain: comparison of direct multi-slice CT arthrography and direct MR arthrography. European Radiology. 2008. DOI: 10.1007/s00330-008-1118-3

[22] Ulnar-Sided Wrist Pain in the Athlete. Clinics in Sports Medicine. 2020. DOI: 10.1016/j.csm.2019.12.008

[23] Influence of Dynamic Factors on Ulnar Impaction Syndrome: An Axial Compression Test Using Fresh-Frozen Cadavers. The Journal of Hand Surgery. 2026. DOI: 10.1016/j.jhsa.2026.02.032

[24] Imaging of Ulnar-Sided Wrist Pain. Clinics in Sports Medicine. 2006. DOI: 10.1016/j.csm.2006.02.008

[25] Distal radioulnar joint configurations in three-dimensional computed tomography in patients with idiopathic ulnar impaction syndrome. Journal of Hand Surgery (European Volume). 2019. DOI: 10.1177/1753193419828330

[26] MRI Findings in Patients Undergoing Triangular Fibrocartilage Complex Repairs Versus Patients Without Ulnar-Sided Wrist Pain. HAND. 2020. DOI: 10.1177/1558944720937369

[28] Surgical Management of Ulnocarpal Impaction Syndrome. The Journal of Hand Surgery. 2010. DOI: 10.1016/j.jhsa.2009.12.035

[30] Radiographic Appearance and Patient Outcome After Ulnar Shortening Osteotomy for Idiopathic Ulnar Impaction Syndrome. The Journal of Hand Surgery. 2012. DOI: 10.1016/j.jhsa.2012.02.038

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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.