Skip to main content

Extensor tendon rupture and preoperative mri confirmations of suture anchor prolapse: a case report and literature review



While suture anchors are widely used in medical procedures for their advantages, they can sometimes lead to complications, including anchor prolapse. This article presents a unique case of suture anchor prolapse at the base of the distal phalanx of the little finger after extensor tendon rupture reconstruction surgery.

Case presentation

A 35-year-old male, underwent extensor tendon rupture reconstruction using a non-absorbable suture anchor. After seven years the patient visited our outpatients complaining of stiffness, pain, and protrusion at the surgical site. Initial X-ray imaging suggested suggesting either a fracture of the distal phalanx or tendon adhesion but lacked a definitive diagnosis. Subsequent magnetic resonance imaging (MRI) revealed bone connectivity between the middle and distal phalanges with irregular signal shadow and unclear boundaries while maintaining a regular finger shape. MRI proved superior in diagnosing prolapsed suture anchors, marking the first reported case of its kind. Surgical intervention confirmed MRI findings.


Suture anchor complications, such as prolapse, are a concern in medical practice. This case underscores the significance of MRI for accurate diagnosis and the importance of tailored surgical management in addressing this uncommon complication.

Peer Review reports


Mallet finger, a condition resulting from trauma to the fingertip, presents as a drooping distal joint due to damage to the extensor tendon. Non-surgical options, such as splinting to maintain joint position, physical therapy for rehabilitation, and the RICE protocol for symptom management are often effective in mild cases. For severe tendon damage or fractures, surgical interventions like Open Reduction and Internal Fixation (ORIF), tendon repair, or joint fusion may be necessary [1]. Advanced techniques, including extensor tendon suture anchor fixation to the base of the distal phalanx, are used in severe cases. This procedure achieves precision by securing the damaged extensor tendon to the bone with suture anchors, promoting optimal healing, and restoring the proper alignment of the distal joint [2, 3]. However, complications may arise in cases of unsuccessful treatment or delayed intervention. Persistent extensor tendon insufficiency can lead to conditions such as DIP (distal interphalangeal) joint flexion contracture, characterized by an inability to fully extend the affected joint. Additionally, swan-neck deformity, marked by hyperextension of the proximal interphalangeal (PIP) joint and flexion of the DIP joint, can occur [4,5,6]. Postoperative care involves immobilization followed by a tailored rehabilitation program to restore functionality. Early diagnosis and an individualized approach to treatment are essential for optimal recovery in mallet finger cases [1, 7, 8]. The suture anchor is a specialized medical implant used in orthopedic surgeries to attach soft tissues, such as tendons and ligaments, to bone [9]. However, the use of suture anchors may result in several potential complications. For instance, an inflammatory response may occur, leading to osteolysis after surgery. Studies have documented significant bony defects in the distal phalanx at the suture anchor insertion site, as seen on X-rays in some cases. Additionally, this inflammatory reaction can cause adhesion of the flexor digitorum profundus (FDP) tendon to the distal phalanx. It is crucial to be aware of these possible complications when considering the use of suture anchors and to carefully monitor patients postoperatively for any signs of adverse reactions [10,11,12,13,14].

This article reports a case where an MRI eventually detected suture anchor prolapse. Despite conducting a physical examination and obtaining X-ray images, the initial assessment was misleading and suggested either a mallet finger or tendon adhesion.

Case presentation

A 35-year-old male patient previously undergone extensor tendon rupture reconstruction surgery on his right little finger at another hospital. During the procedure, a suture anchor was placed at the base of the distal phalanx. Seven years post-surgery, the patient visited our department, complaining of pain, and stiffness in his finger. Notably, he reported no post-surgical trauma. Physical examination showed an inability to achieve full dorsal extension, but there was no disturbance of circulation or swelling. Mild redness and signs of infection were observed, along with a noticeable protrusion at the surgical site. An X-ray was performed, revealing an anomaly at the base of the distal phalanx of the little finger, raising suspicions of either a distal phalanx fracture or tendon adhesion (Fig. 1).

Fig. 1
figure 1

X-ray of the right hand presenting a malunion fracture block at the middle and distal phalanges of the right little finger

Following further investigation, an MRI was performed, revealing abnormal alterations in both the middle and distal phalanges of the right little finger. These changes were characterized by compromised bone connectivity, irregular areas of patchy high signal shadows (notably with lipid suppression), and indistinct boundaries. Notably, the bone morphology of the other right fingers appeared normal, displaying no discernible abnormal signals. Additionally, the joint surfaces were smooth, with no abnormalities detected in the surrounding soft tissues (Fig. 2a, c). Therefore, the patient underwent surgery, where a significant amount of scar tissue around the inserted suture anchor. Following the removal of the scar tissue, it was discovered that the tail of the anchor was located in the center of the extensor tendon, close to the subcutaneous area, and protruding. Attempts to clamp the anchor directly through the tail were unsuccessful. After the base is enlarged with an electric drill, the anchor was completely removed. The bone defect was reinforced by artificial bone grafting and re-repair of the extensor tendon was performed (Fig. 3). Our patient was diagnosed with anchor prolapse, which was clearly visible on magnetic resonance MRI.

Fig. 2
figure 2

Comparing between MRI before and after the surgery. (a, c) preoperative images, show a foreign body, which did not rupture the extensor tendon, and a poor bone connectivity of the middle and distal phalanges, with patchy (lipid suppression) high signal shadow and unclear boundary at distal phalanx of the little finger(narrows). (b, d) postoperative images, present no foreign body shadow

Fig. 3
figure 3

Suture anchor prolapse at the base of distal phalanges of the right little finger, which could be misdiagnosed as an osteophyte or tendon adhesion

A finger-cap fixation was applied for one month, accompanied by the administration of oral antibiotics. The stitches were subsequently removed two weeks post-surgery. Functional exercises began after two weeks. At one month follow-up, the flexion and extension function of the distal segment showed improvement compared to its pre-operative state, and the nearly full range of motion was observed at the second-month follow-up (Fig. 2b, d, and Fig. 4).

Fig. 4
figure 4

Second month after removing the prolapsed suture anchor, noticeable improvement of the movement of the right little finger


Suture anchors represent a pivotal advancement in modern surgical techniques, particularly in the field of orthopedic and sports medicine. Their primary function is to enable the secure attachment of soft tissues, such as ligaments and tendons, to bone, a task that traditional suturing methods may not adequately accomplish. These anchors, typically composed of metal or biocompatible polymers, are meticulously designed for insertion into the bone, providing a robust and reliable anchorage point for sutures. This technology is especially beneficial in areas subjected to high stress and movement, such as shoulder, hand, and knee joints, where it ensures a stable and enduring tissue-to-bone healing process. The utilization of suture anchors has been instrumental in reducing recovery time, minimizing postoperative complications, and enhancing the overall success rates of orthopedic surgeries. Their versatility and effectiveness in various surgical contexts underscore their significance in contemporary medical practice [15, 16].

A key factor in the successful use of suture anchors is the selection of the appropriate anchor. This choice involves considering the size and material of the anchor, which may vary from metallic to bioabsorbable, depending on the patient’s condition and the specific surgical requirements. Moreover, the insertion technique is paramount [17]. The insertion process involves loading the suture into the anchor implant, placing it into a pre-drilled bone hole, and then applying tension by pulling on the free suture ends. This is followed by securing the suture end to suture cleats for stabilization, as described by Kevi Es Neison and Joodan Ei Foof [18]. According to Johnstone and Karuppiah [19], a proper technique involves using a guide wire or pilot hole for precise placement and ensuring that the anchor is inserted at an optimal angle to maximize pull-out strength. Additionally, it is vital to avoid overtightening the anchor, as this can lead to bone damage or anchor loosening [19]. To facilitate easier insertion of suture anchors, surgeons may employ various techniques. Proper drilling, using the correct drill bit size and depth, is crucial. Depth gauges can aid in achieving the correct depth and prevent drilling too deep or shallow. Enhanced visualization techniques, such as arthroscopic or imaging methods, are also recommended for precise placement, especially in less accessible surgical areas. Additionally, the use of ergonomic instruments designed for anchor insertion can improve the surgeon’s control and accuracy during the procedure [17, 20, 21]. However, the use of suture anchors is not without its disadvantages. The risk of prolapse or migration of the anchor remains a concern, particularly if the placement technique is not precise. There is also a potential risk of infection, a common issue with any surgical implant. Cost is another factor, as suture anchors tend to be more expensive than traditional suturing methods. Lastly, the effectiveness of suture anchors relies heavily on the surgeon’s expertise and experience, indicating a significant learning curve for optimal use [22, 23].

Suture anchor prolapse, where the anchor dislodges or moves from its initially intended position, can occur for several reasons, and understanding these factors is crucial for preventing such complications. One of the primary reasons for suture anchor prolapse is poor bone quality. In patients with osteoporosis or other conditions that weaken the bone, the anchor may not secure properly, leading to a higher risk of prolapse. This issue is particularly significant in elderly patients or those suffering from diseases that affect bone density. Additionally, the use of an anchor that is too small or not suitable for the specific bone density can also lead to inadequate fixation strength, increasing the likelihood of prolapse. It’s essential to select an anchor size and type that is compatible with the patient’s bone quality and the specific requirements of the surgical procedure [24, 25]. In addition, incorrect placement of the suture anchor is another significant factor contributing to prolapse. If the anchor is not placed at the correct depth or angle, it may not hold securely in the bone. Placement that is too superficial or in an area of the bone with less density can compromise the anchor’s stability. Furthermore, overloading the anchor by applying excessive tension to the suture or using it in a high-stress area without adequate support can lead to the failure of the anchor. Surgeons must ensure that the anchor is placed correctly and that the suture is tensioned appropriately to prevent such issues [22, 24]. Suboptimal surgical techniques can also lead to anchor prolapse. Inadequate preparation of the anchor site, such as not pre-drilling a hole to the appropriate size or not cleaning the hole of debris before anchor insertion, can affect the anchor’s grip in the bone. Precision in surgical technique and thorough site preparation are therefore essential [26, 27]. Furthermore, Patient factors play a significant role as well. Activities that place excessive stress on the area soon after surgery or non-compliance with postoperative restrictions can contribute to anchor prolapse. Additionally, conditions that affect healing, such as diabetes or smoking, may also increase the risk [22, 28, 29]. Suture anchor prolapse can often result in a range of symptoms, such as pain, stiffness, and mass projection at the prolapsed site, which can be similar to other conditions such as distal phalanx fracture and tendon adhesion. X-ray imaging of anchor prolapse typically reveals an avulsion fragment at the insertion site of the common extensor tendon on the distal phalanx at the distal interphalangeal joint, which may resemble a mallet finger type of distal phalanx fracture or tendon adhesion [16]. Distal phalanx fractures are frequently encountered in both emergency departments and outpatient clinics. Mallet finger deformities typically result from an avulsion injury to the terminal tendon of the distal phalanx, which leads to the detachment of a bone fragment from the insertion of the terminal tendon [30]. X-ray imaging typically reveals an avulsion fragment at the base of the common extensor tendon, indicating a mallet finger injury. Notably, a high proportion of mallet finger injuries present as isolated tendon injuries without associated avulsion fractures [31]. In addition, tendon adhesion, characterized by the adhesion of tendons to surrounding tissues and the loss of range of movement, can be diagnosed at the distal phalanx of the little finger by X-ray imaging and during the physical examination [32,33,34,35]. Tendon adhesion is a reported complication in up to 20% of patients with tendon injuries [32,33,34,35].

Therefore, our case presented the benefit of MRI in diagnosing and locating the suture anchor prolapse at the distal phalanx of the little finger after, which had been misdiagnosed by X-ray imaging. The MRI scan revealed unusual changes in both the middle and distal phalanges of the right little finger. These changes were characterized by compromised bone connectivity, irregular areas of patchy high signal shadows (notably with lipid suppression), and indistinct boundaries, conclusively confirmed the presence of suture anchor prolapse. The MRI finding was confirmed through surgical intervention. In contrast, conditions such as mallet finger and tendon adhesion are typically diagnosed through clinical examination, ultrasound, and X-ray imaging.


This article presents a case in which the eventual identification of suture anchor prolapse was made through MRI, revealing a discrepancy from the initial assessment. Despite a thorough physical examination and the acquisition of X-ray images, the initial evaluation was misleading, pointing towards potential diagnoses such as a mallet finger or tendon adhesion. An inaccurate diagnosis may result in delayed or inappropriate treatment, underscoring the importance of careful consideration of radiological findings. Therefore, MRI has proven to be an invaluable diagnostic tool for detecting prolapsed suture anchors.

Data availability

No datasets were generated or analysed during the current study.



Magnetic resonance imaging


Open Reduction and Internal Fixation


(distal interphalangeal)


Proximal interphalangeal joint


Flexor digitorum profundus


  1. Sivakumar BS, Graham DJ, Ledgard JP, Lawson RD. Acute Mallet Finger Injuries-A Review. J Hand Surg. 2023;48(3):283–91.

    Article  Google Scholar 

  2. Sandjaya G, Prabowo I, Patih ID. Terminal extensor tendon reconstruction as a reliable options for chronic mallet finger with swan neck deformity of index finger: A case report. Annals of medicine and surgery (2012) 2022, 78:103924.

  3. Hong CC, Tan KJ. Suture Anchor fixation of unstable Bony Mallet injuries of the Hallux. Foot Ankle Int. 2013;34(12):1737–41.

    Article  PubMed  Google Scholar 

  4. Biernacki SD. A flexion contracture splint for the distal interphalangeal joint: distal interphalangeal joint flexion contracture splinting. J hand Therapy: Official J Am Soc Hand Therapists. 2001;14(4):302–3.

    Article  CAS  Google Scholar 

  5. Millesi H. [On the flexion contracture of the distal interphalangeal joint within the scope of Dupuytren’s contracture]. Bruns’ Beitr fur Klinische Chirurgie. 1967;214(4):400–5.

    CAS  Google Scholar 

  6. Lane R, Nallamothu SV. Swan-Neck Deformity. In: StatPearls edn. Treasure Island (FL) ineligible companies. Disclosure: Shivajee Nallamothu declares no relevant financial relationships with ineligible companies.: StatPearls Publishing Copyright © 2023, StatPearls Publishing LLC.; 2023.

  7. Bendre AA, Hartigan BJ, Kalainov DM. Mallet finger. J Am Acad Orthop Surg. 2005;13(5):336–44.

    Article  PubMed  Google Scholar 

  8. Bachoura A, Ferikes AJ, Lubahn JD. A review of mallet finger and jersey finger injuries in the athlete. Curr Rev Musculoskelet Med. 2017;10(1):1–9.

    Article  PubMed  PubMed Central  Google Scholar 

  9. Barbara D, Buch, Innis P, Michael A. McClinton: the mitek mini G2 suture anchor: biomechanical analysis of use in the hand. J Hand Surg. 1995;20(5):877–81.

    Article  Google Scholar 

  10. Galano GJ, Jiang KN, Strauch RJ, Rosenwasser MP, Tang P. Inflammatory response with Osteolysis related to a Bioabsorbable Anchor in the Finger: a Case Report. Hand (New York NY) 2010, 5(3).

  11. Schrumpf MA, Lee AT, Weiland AJ. Foreign-body reaction and Osteolysis Induced by an Intraosseous Poly-L-Lactic Acid Suture Anchor in the wrist: Case Report. J Hand Surg. 2011;36(11):1769–73.

    Article  Google Scholar 

  12. B??Stman OM, Pihlajam??Ki HK. Adverse tissue reactions to bioabsorbable fixation devices. Clin Orthop Relat Res. 2000;371:216–27.

  13. Casteleyn P, Handelberg F, Haentjens P. Biodegradable rods versus Kirschner wire fixation of wrist fractures. A randomised trial. J Bone Joint Surgery-british Volume. 1992;74(6):858–61.

    Article  CAS  Google Scholar 

  14. Rokkanen PU, B?Stman O, Hirvensalo E, Mkel EA, Partio EK, Ptil H, Vainionp S, Vihtonen K, Trml P. Bioabsorbable fixation in orthopaedic surgery and traumatology. 2000, 21(24):2607–13.

  15. Mccallister WV, Ambrose HC, Katolik LI, Trumble TE. Comparison of Pullout Button Versus Suture Anchor for Zone I flexor Tendon Repair. J Hand Surg. 2006;31(2):246–51.

    Article  Google Scholar 

  16. Rehak DC, Sotereanos DG, Bowman MW, Herndon JH. The Mitek bone anchor: application to the hand, wrist and elbow. J Hand Surg. 1994;19(5):853.

    Article  CAS  Google Scholar 

  17. Cole BJ, Romeo AA. Arthroscopic shoulder stabilization with suture anchors: technique, Technology, and Pitfalls. Clin Orthop Relat Research®. 2001;390:17–30.

    Article  Google Scholar 

  18. Hoof JACC, AZ, US), Nason KS, Chandler, AZ, US) ANCHORS AND METHOD FOR SECURING SUTURE TO BONE. United States CAYENNE MEDICAL, INC (Scottsdale, AZ, US) 20100004683 2010.

  19. Johnstone AJ, Karuppiah SV. A SINGLE STAGE INSERTION NOVEL DESIGN SUTURE ANCHOR. In: 2009; 2009.

  20. Joshi A, Basukala B, Sharma R, Singh N, Bista R, Pradhan I. Make and use all suture Anchor—A cost-effective method of making an All-Suture Anchor. Arthrosc Techniques. 2023;12(8):e1311–8.

    Article  Google Scholar 

  21. Nagra NS, Zargar N, Smith RD, Carr AJ. Mechanical properties of all-suture anchors for rotator cuff repair. Bone Joint Res. 2017;6(2):82–9.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  22. Li X, Xiao Y, Shu H, Sun X, Nie M. Risk factors and corresponding management for suture Anchor Pullout during Arthroscopic Rotator Cuff Repair. J Clin Med 2022, 11(22).

  23. Kaar TK, Schenck RC, Wirth MA, Rockwood CA. Complications of metallic suture anchors in shoulder surgery: a report of 8 cases. Arthroscopy: J Arthroscopic Relat Surg : Official Publication Arthrosc Association North Am Int Arthrosc Association. 2001;17:31–7.

    Article  CAS  Google Scholar 

  24. Er MS, Altinel L, Eroglu M, Verim O, Demir T, Atmaca H. Suture anchor fixation strength with or without augmentation in osteopenic and severely osteoporotic bones in rotator cuff repair: a biomechanical study on polyurethane foam model. J Orthop Surg Res. 2014;9:48.

    Article  PubMed  PubMed Central  Google Scholar 

  25. Tingart MJ, Apreleva M, Lehtinen J, Zurakowski D, Warner JJ. Anchor design and bone mineral density affect the pull-out strength of suture anchors in rotator cuff repair: which anchors are best to use in patients with low bone quality? Am J Sports Med. 2004;32(6):1466–73.

    Article  PubMed  Google Scholar 

  26. Chaudhry S, Dehne K, Hussain F. A review of suture anchors. Orthop Trauma. 2019;33(4):263–70.

    Article  Google Scholar 

  27. Chen Y, Zheng Y, Xu L-F, Chen L. Zheng’s anchor suturing technique for safe and cosmetic umbilical incision in transumbilical laparoendoscopic single-site surgeries. Surg Today. 2023;53(2):274–7.

    Article  PubMed  Google Scholar 

  28. Giannikas D, Athanaselis E, Matzaroglou C, Saridis A, Tyllianakis M. An unusual complication of Mitek suture anchor use in primary treatment of flexor digitorum profundus tendon laceration: a case report. Cases J. 2009;2:9319.

    Article  PubMed  PubMed Central  Google Scholar 

  29. Rodgerson DH, Spirito MA. Repair of collateral ligament instability in 2 foals by using suture anchors. Can Vet J. 2001;42(7):557–60.

    CAS  PubMed  PubMed Central  Google Scholar 

  30. Cannon NM. Rehabilitation approaches for distal and middle phalanx fractures of the hand. J Hand Ther. 2003;16(2):105–16.

    Article  PubMed  Google Scholar 

  31. Wieschhoff GG, Sheehan SE, Wortman JR, Dyer G, Sodickson AD, Patel KI, Khurana B. Traumatic finger injuries: what the Orthopedic Surgeon wants to know. Radiographics Rev Publication Radiological Soc North Am Inc. 2016;36(4):1106.

    Google Scholar 

  32. Strickland JW, Glogovac SV. Digital function following flexor tendon repair in Zone II: a comparison of immobilization and controlled passive motion techniques. J Hand Surg. 1980;5(6):537–43.

    Article  CAS  Google Scholar 

  33. Clayton RAE, Court-Brown CM. The epidemiology of musculoskeletal tendinous and ligamentous injuries. Injury-international J Care Injured. 2008;39(12):1338–44.

    Article  Google Scholar 

  34. Jaibaji M. Advances in the biology of zone II flexor tendon healing and adhesion formation. Ann Plast Surg. 2000;45(1):83–92.

    Article  CAS  PubMed  Google Scholar 

  35. Wang E. Tendon repair. J Hand Ther. 1998;11(2):105–10.

    Article  CAS  PubMed  Google Scholar 

Download references


Thanks to Fatima and Maling for their support and encouragement.


The study was funded by Zhejiang Provincial Natural Science Foundation of China (LS21H060001). The funding body had no role in the design of the study; in collection, analysis, and interpretation of data; and in drafting the manuscript.

Author information

Authors and Affiliations



HL, Sahar, XZ, and ZW designed the study, performed data collection and supervission; Ahmad, Yanzhao, Haiying, Sohaib, and FY wrote and drafted the manuscript. The authors have read and approved the final manuscript.

Corresponding authors

Correspondence to Sahar Ahmed Abdalbary or Hui Lu.

Ethics declarations

Ethics approval and consent to participate

Not applicable.

Consent to publication

Written informed consent was obtained from the patient for publication of the case report.

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Alhaskawi, A., Zhou, H., Dong, Y. et al. Extensor tendon rupture and preoperative mri confirmations of suture anchor prolapse: a case report and literature review. BMC Musculoskelet Disord 25, 355 (2024).

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: