Skip to main content

Implantation of an attachment tube preserves knee extension after nonunion of Felix IV fracture: a case report



While commonly utilized to fix tissue and muscles to megaprostheses to restore function and stability after tumor surgery, an attachment tube was used as a synthetic reconstruction of the knee joint’s extension mechanism after nonunion of Felix IV C fracture. Fixation of the tibial fragment, and therefore its osteointegration, is complicated after total knee arthroplasty, causing tibial tubercle dislocation.

Case presentation

A 61-year-old German patient presented to our clinic with Felix IV C fracture, persistent knee pain, and reduced knee extension strength. In this special case, mobilization and reattachment of the tibial tubercle was not possible because of necrosis and underlying tibial component. Therefore, we covered the defect with cement and used an polyethylene terephthalate tube for knee extension system augmentation. Follow-up after 10 months demonstrated a good clinical result.


The management of Felix IV C fractures is complicated by the underlying prosthesis resulting in redislocation of the fragment and persistent symptoms of pain and reduced functionality. We here present a new surgical technique to treat periprosthetic fracture complicated by tibial tubercle dislocation. Good clinical and radiologic results on follow-up after 10 months indicate the use of attachment tubes as a suitable surgical technique to restore knee joint extension and to reduce knee pain after dislocated Felix IV C fracture.

Peer Review reports


Periprosthetic fractures of the tibia have a low prevalence of 0.4–1.7% [1], but since there the number of total knee arthroplasties (TKA) is increasing, it has become a significant complication in orthopedic surgery [2]. Therapy consists of osteosynthesis with plates or screws, but since the tibial stems limit the options of fragment refixation, periprosthetic tibial fractures are difficult to treat, having a high risk of nonunion and dislocation [3].

Herein, we report the reconstruction of the knee joint’s extension system with a polyethylene terephthalate tube after nonunion of tibial Felix IV C fracture [4].

Case presentation

A 61-year-old German woman presented to our orthopedic clinic after Felix IV fracture in revision total knee arthroplasty. Two years ago, the patient had undergone revision TKA with a rotating hinge prosthesis complicated by an intraoperative fracture of the tibial tubercle. Screw fixation had been performed, but 3 months later nonunion of the fragment had persisted, resulting in plate osteosynthesis with a one-third tubular plate. After another dislocation of the tibial tubercle, the patient presented to our clinic with anterior knee pain, loss of extension strength, and a feeling of rotational instability. On clinical examination, pressure pain of the proximal tibia, decreased extension strength to Janda 3/5, and inability to raise the extended knee were noticed. This maintained extensor function is the result of an intact medial and lateral retinaculum. The knee’s range of motion was 0–110° of flexion with preserved mediolateral and anterior/posterior stability. X-ray showed the rotation hinge prosthesis without loosening signs, the one-third tubular plate, and the dislocated tibial tubercle fragment indicating persistent Felix IV C fracture (Fig. 1).

Fig. 1

Preoperative x-ray shows dislocated tibial tubercle, one-third plate, rotation hinge prosthesis without loosening signs and regular patella tracking. a Frontal view. b Sagittal view shows dislocated tibial tubercle. c Axial view shows regular patella tracking

Reconstruction of the knee joint’s extension system was planned. After preparation of the subcutaneous tissue, the dislocated tibial tubercle appeared surrounded by extensive metallosis (Fig. 2a) presumably induced by the contact between the one-third tubular plate and the tibial prosthesis. Following the removal of the plate, the fragment proved to be necrotic requiring a total extirpation instead of mobilization and refixation. Subsequently, the ventral surface of the tibial prosthesis was exposed (Fig. 2b). Reconstruction of the extension system should be performed by the implantation of MUTARS attachment tube made of polyethylene terephthalate. Since the tibial prosthesis did not offer any connecting points for the synthetic graft, cement was used as an extender to simultaneously serve as fixing point and to preserve the prosthesis from loosening. Afterwards, the tube was doubled into a laminar sheet and fixed with two cancellous bone screws in the ventral tibia (Fig. 2c, d). ORTHOCORD sutures were used to attach the tube to the articular capsule still beyond the patella (Fig. 2d,e). Extensive jet lavage was performed before wound closure. Check of patellar tracking was promising; likewise, postoperative X-ray showed regular patella position (Fig. 3).

Fig. 2

Intraoperative procedures: a After preparation of subcutaneous tissue, the one-third plate appeared completely surrounded with metallosis. b The necrotic tibial tubercle was removed so that the tibial prosthesis was exposed. c, d The polyethylene terephthalate tube was doubled to form a planar sheet and fixed with two cancellous bone screws in the proximal tibia. e Joint capsule was sutured so that the attachment-tube is arranged above. f The attachment-tube was fixed with non absorbable ORTHOCORD® at the joint capsule and the M. quadriceps femoris

Fig. 3

Postoperative x-ray shows cement augmentation of resected tibial tubercle and regular patella position. a Frontal view. b Sagittal view shows cement augmentation and correct patella position without cranial dislocation

To support the integration of the tube in the surrounding subcutaneous tissue, knee flexion was at first limited to 30° and then escalated to 60° and 90° every 2 weeks with full weight-bearing.

Follow-up was performed after 3 and 10 months. On clinical examination (Fig. 4), the patient showed irritant-free skin and soft tissue conditions; no redness or overheating; extension/flexion 0–0–110°; straight-leg raise completely possible; and force level 4/5 on side comparison of the knee stretchers. Active knee stretching with a flexed knee joint was possible without any problems. There was a centered patella run and no subluxation of the patella. Peripheral circulation, motor skills, and sensitivity were intact. X-ray confirmed correct implant position and central patella tracking (Fig. 5). The patient was highly pleased by the restored extension function and significantly reduced knee pain.

Fig. 4

Clinical follow up after ten month: In the clinical examination the patient showed a range of motion with extension/flexion 0-0-110°, straight-leg-raise was completely possible. a Full knee extension of 0°. b Straight-leg-raise. c Knee flexion until 110°

Fig. 5

Radiologic follow up after ten month: X-ray shows correct implant position without periprosthetic bone lesions and centered patella tracking. a Frontal view. b Sagittal view shows still correct position of cement augmentation. c Axial view shows regular patella tracking


Periprosthetic tibial fractures are difficult to treat since the tibial segment hinders the fixation of osteosynthesis implants. A minimum of eight screws or the use of locking plates is recommended, but nevertheless, there are high rates of nonunion and dislocation of tibial fragments [5]. In the present case, we presented a surgical method to preserve extension functionality after Felix IV fracture and failed osteosynthesis of tibial tubercle fragment.

Multiple operation techniques exist to restore the knee joint’s extension system [6]. While primary repair was not possible since the necrotic tibial tubercle and concomitant patellar tendon insertion had to be removed, augmentation techniques were required. Not only autologous but also allograft reconstructions have been described resulting in unsatisfying long-term results with progressive extensor lag due to poor tissue quality [7,8,9]. Therefore, Browne et al. developed a synthetic augmentation technique to restore patellar tendon function providing long-term tensile strength and extensor functionality [10]. So, overall, in the case of patellar tendon or quadriceps tendon rupture, synthetic augmentation techniques are recommended [6]. Attachment tubes are commonly used in tumor surgery to restore function and stability after joint removal. Among them, reconstruction of the extension system of the knee joint in combination with a megaprosthesis is an approved method with promising outcomes concerning knee extension and knee flexion. On the one hand, in the case of megaprostheses, the attachment tube is fixed to the retention strings or a specific ventral anchorage block of the prosthetic device [11,12,13,14]. On the other hand, in the case of TKA with surrounding tibial bone, Browne et al. fixed the mesh graft intramedullary by bone cement instead of superficial anchorage to avoid proximal tibial fracture or tibial tubercle nonunion [10].

The present case required a different fixation technique since the tibial prosthesis was not designed to serve as a fixing point for the polyethylene terephthalate tube and the overlaying tibial tubercle as intramedullary anchorage had to be removed. Due to the extension strength acting on the tube and concomitantly on the attachment point, a direct fixation only on the ventral surface of the prosthesis would lead to ventral breakaway of the prosthesis aggravated by the missing frontal stability. Therefore, we compensated for the tibial defect by cement augmentation and attached the tube to the proximal tibia with two cancellous bone screws. As approved in tumor surgery [12], nonabsorbable sutures were used to fix the tube to the joint capsule and the extension system. Since the attachment tube in combination with endoprosthetic material is known to exhibit high infection rates [15], extensive jet lavage was performed before wound closure.

Within 6 months, the polyethylene terephthalate tube is known to be completely interspersed with fibroblasts resulting in a scarred tear-resistant tissue plate (16). So, when the tube stability reduces over time, its function will be replaced by autologous tissue to maintain tensile strength.


In cases of Felix IV fractures, the use of plates and screws is recommended. Nevertheless, the management is often complicated by the underlying prosthesis components. We presented a reasonable surgical method using an attachment tube to treat dislocated Felix IV fractures with loss of tibial tubercle reducing knee pain and preserving extension functionality.

Availability of data and materials

Data sharing is not applicable to this article as no datasets were generated or analyzed during the current study.


  1. 1.

    Yoo JD, Kim NK. Periprosthetic fractures following total knee arthroplasty. Knee Surg Relat Res. 2015;27(1):1.

    CAS  Article  Google Scholar 

  2. 2.

    Inacio MCS, Paxton EW, Graves SE, Namba RS, Nemes S. Projected increase in total knee arthroplasty in the United States—an alternative projection model. Osteoarthritis Cartilage. 2017;25(11):1797–803.

    CAS  Article  Google Scholar 

  3. 3.

    Morwood MP, Gebhart SS, Zamith N, Mir HR. Outcomes of fixation for periprosthetic tibia fractures around and below total knee arthroplasty. Injury. 2019;50(4):978–82.

    Article  Google Scholar 

  4. 4.

    Felix NA, Stuart MJ, Hanssen AD. Periprosthetic fractures of the tibia associated with total knee arthroplasty. Clin Orthop Relat Res. 1997;345:113–24.

    Article  Google Scholar 

  5. 5.

    Kim H-J, Park K-C, Kim J-W, Oh C-W, Kyung H-S, Oh J-K, et al. Successful outcome with minimally invasive plate osteosynthesis for periprosthetic tibial fracture after total knee arthroplasty. Orthop Traumatol Surg Res. 2017;103(2):263–8.

    Article  Google Scholar 

  6. 6.

    Thiele K, von Roth P, Pfitzner T, Preininger B, Perka C. Quadriceps tendon insufficiency and rupture: treatment options in total knee arthroplasty. Orthopade. 2016;45(5):407–15.

    CAS  Article  Google Scholar 

  7. 7.

    Brown NM, Murray T, Sporer SM, Wetters N, Berger RA, della Valle CJ. . Extensor mechanism allograft reconstruction for extensor mechanism failure following total knee arthroplasty. JBJS. 2015;97(4):279–83.

    Article  Google Scholar 

  8. 8.

    Leopold MSS, Greidanus N, Paprosky WG, Berger RA, Rosenberg AG. High rate of failure of allograft reconstruction of the extensor mechanism after total knee arthroplasty. JBJS. 1999;81(11):1574–9.

    CAS  Article  Google Scholar 

  9. 9.

    Cadambi A, Engh GA. Use of a semitendinosus tendon autogenous graft for rupture of the patellar ligament after total knee arthroplasty. A report of seven cases. JBJS. 1992;74(7):974–9.

    CAS  Article  Google Scholar 

  10. 10.

    Browne JA, Hanssen AD. Reconstruction of patellar tendon disruption after total knee arthroplasty: results of a new technique utilizing synthetic mesh. JBJS. 2011;93(12):1137–43.

    Article  Google Scholar 

  11. 11.

    Hardes J, Ahrens H, Nottrott M, Dieckmann R, Gosheger G, Henrichs MP, et al. Attachment tube for soft tissue reconstruction after implantation of a mega-endoprosthesis. Oper Orthop Traumatol. 2012;24(3):227–34.

    CAS  Article  Google Scholar 

  12. 12.

    Gosheger G, Hillmann A, Lindner N, Rödl R, Hoffmann C, Bürger H, et al. Soft tissue reconstruction of megaprostheses using a trevira tube. Clin Orthop Relat Res. 2001;393:264–71.

    Article  Google Scholar 

  13. 13.

    Holzapfel BM, Pilge H, Toepfer A, Jakubietz RG, Gollwitzer H, Rechl H, et al. Proximal tibial replacement and alloplastic reconstruction of the extensor mechanism after bone tumor resection. Oper Orthop Traumatol. 2012;24(3):247–62.

    CAS  Article  Google Scholar 

  14. 14.

    Wilken F, Banke IJ, Hauschild M, Winkler S, Schott K, Rudert M, et al. Tumorendoprothetik. Orthopade. 2016;45(5):439–45.

    CAS  Article  Google Scholar 

  15. 15.

    Gosheger G, Gebert C, Ahrens H, Streitbuerger A, Winkelmann W, Hardes J. Endoprosthetic reconstruction in 250 patients with sarcoma. Clin Orthop Relat Res. 2006;450:164–71.

    Article  Google Scholar 

  16. 16.

    Trieb K, Blahovec H, Brand G, Sabeti M, Dominkus M, Kotz R. In vivo and in vitro cellular in growth into a new generation of artificial ligaments. Eur Surg Res. 2004;36(3):148–51.

    CAS  Article  Google Scholar 

Download references


Not applicable.


Open Access funding enabled and organized by Projekt DEAL.

Author information




AR assisted with the surgery and authored this manuscript. HW substantively revised the manuscript. ME developed the idea of the surgical technique, performed the surgery, and revised the manuscript. All authors read and approved the final manuscript.

Corresponding author

Correspondence to Alena Richter.

Ethics declarations

Ethics approval and consent to participate

Not applicable.

Consent for publication

Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.

Competing interests

The authors declare that they have 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

Verify currency and authenticity via CrossMark

Cite this article

Richter, A., Windhagen, H. & Ettinger, M. Implantation of an attachment tube preserves knee extension after nonunion of Felix IV fracture: a case report. J Med Case Reports 15, 534 (2021).

Download citation


  • Case report
  • Felix IV fracture
  • Periprosthetic fracture
  • Attachment-tube
  • Knee joint extension