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

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 [32‐35]. Tendon adhesion is a reported complication in up to 20% of patients with tendon injuries [32‐35].

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.