A 14‐year‐old girl with spastic quadriplegic cerebral palsy was seen 5 months after she had undergone extension osteotomy with internal fixation. She was unable to stand and experienced severe pain, numeric rating scale (NRS) 8–9 during any active or passive movement of the left knee. During the physical examination, noticeable swelling was observed around the knee joint, which was also painful upon palpation. The range of motion was reduced by severe pain: the extension was reduced by 55° and flexion was only 95° (sagittal, frontal, transverse, rotation [SFTR] 055‐95). She experienced severe pain during knee extension, particularly on the posterior and lateral part of the knee. As such, she kept a flexed and internally rotated knee position during rest. The patient also reported some relief from pain when the knee was secured with a brace.
Ragiographic examination was performed (Figure 1A,B), revealing that the screws extended beyond the bony contour on the fibular side of the knee joint. Ultrasound (US) examination was also performed, showing fluid accumulation in the suprapatellar recess (Figure 1C). Additionally, within the lateral aspect of the knee joint, between the femur and tibia, a metallic object was observed (Figure 1D). The clinical findings of the patient were attributed to the malaligned screw, and a revision surgery was performed. Postoperatively, the patient has significant pain relief (NRS 4/10) and improved range of motion (SFTR 0–30‐100). In the US examination there was significant reduction of fluid accumulation in the suprapatellar recess (Figure 1E), and in the lateral aspect of the joint the metallic object was not observed.
FIGURE 1.
Anteroposterior (A) and lateral (flexed) (B) knee radiographs show the screws extending beyond the bony contours on the fibular side. Knee ultrasonography shows the suprapatellar effusion (asterisk) in the anterior long‐axis view (C) and the metallic artifact of the screw (arrow) within the joint space between femur and tibia in the lateral long‐axis view (D). Reduction of the fluid accumulation postoperatively (E).
Displacement of surgical hardware within the knee joint can cause severe pain, loss of mobility, and further joint damage. 1 Early detection and management of such complications are critical for preventing long‐term morbidity and ensuring the success of the initial surgical intervention. Traditionally, radiographs have been the cornerstone of postoperative assessment, however, their ability to demonstrate the relationship as regards the soft tissues are limited. US and magnetic resonance imaging (MRI) have been identified as effective tools in this regard; however, limitations of MRI include its cost, inconvenience, and the fact that some metals are not compatible. 2 , 3 US provides higher resolution, dynamic examination, sonopalpation and better interpretation of the patient's clinical findings and may be the preferred diagnostic modality in select patients. 4 , 5 , 6
ETHICS STATEMENT
The research proposal was approved by the ethics committee of the Second Medical Faculty, Charles University and University Hospital Motol, Prague, Czech Republic.
INFORMED CONSENT
The patient's parents provided written informed consent for the publication of this anonymous case report.
DISCLOSURE
None.
ACKNOWLEDGMENT
Open access publishing facilitated by Univerzita Karlova, as part of the Wiley ‐ CzechELib agreement.
Türkekul P, Jačisko J, Jevič F, Kobesova A, Özçakar L. Identifying malaligned knee screw during ultrasound examination. PM&R. 2025;17(9):1120‐1121. doi: 10.1002/pmrj.13344
REFERENCES
- 1. Vena G, D'Adamio S, Amendola A. Complications of osteotomies about the knee. Sports Med Arthrosc Rev. 2013;21(2):113‐120. doi: 10.1097/JSA.0b013e3182900720 [DOI] [PubMed] [Google Scholar]
- 2. Czyrny Z. US and MR imaging of the postoperative knee. Eur J Radiol. 2007;62(1):44‐67. doi: 10.1016/j.ejrad.2007.01.018 [DOI] [PubMed] [Google Scholar]
- 3. Wajid SA, Ahmed S, Devera V, Dickerson D, Thompson A, Villela J. Comparison of the effectiveness of portable ultrasound vs portable X‐ray as diagnostic imaging of knee structures in clinical medicine. J Adv Med Pharm Sci. 2020;5:41‐50. doi: 10.9734/jamps/2020/v22i630178 [DOI] [Google Scholar]
- 4. Gibbs TS. The use of sonography in the identification, localization, and removal of soft tissue foreign bodies. J Diagn Med Sonogr. 2006;22(1):5‐21. doi: 10.1177/8756479305283985 [DOI] [Google Scholar]
- 5. Saboo SS, Saboo SH, Soni SS, Adhane V. High‐resolution sonography is effective in detection of soft tissue foreign bodies: experience from a rural Indian center. J Ultrasound Med. 2009;28(9):1245‐1249. doi: 10.7863/jum.2009.28.9.1245 [DOI] [PubMed] [Google Scholar]
- 6. Blyme PJH, Lind T, Schantz K, Lavard P. Ultrasonographic detection of foreign bodies in soft tissue: a human cadaver study. Arch Orthop Trauma Surg. 1990;110(1):24‐25. doi: 10.1007/BF00431361 [DOI] [PubMed] [Google Scholar]