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Year : 2022  |  Volume : 1  |  Issue : 1  |  Page : 32-36

Uniplanar monorail fixator for knee arthrodesis in triple deformity, an effective technique

Department of Orthopaedics, AIIMS, Rishikesh, Uttarakhand, India

Date of Submission28-Nov-2022
Date of Acceptance14-Dec-2022
Date of Web Publication23-Jan-2023

Correspondence Address:
Roop Bhusan Kalia
Department of Orthopaedics, AIIMS, Rishikesh - 249 203, Uttarakhand
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/juoa.juoa_11_22

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Limb reconstruction system (LRS) is a preferred method of choice for limb lengthening as well as to achieve the optimum level of compression in arthrodesis, thus enhancing primary bone healing. The case of a 30-year-old female diagnosed with triple deformity of the right knee due to advanced tubercular arthritis underwent left knee arthrodesis with uniplanar bilateral LRS fixator after 2 years of illness. The patient had an optimal fusion in the postoperative period with satisfactory outcomes regarding pain and mobilization. There are lots of cases of tubercular knee that might land into advanced tubercular arthritis. Such cases can have this sort of surgical management as an effective means.

Keywords: Arthrodesis, deformity, fixator

How to cite this article:
Kurmi AC, Kalia RB, Ansari S, Paul S. Uniplanar monorail fixator for knee arthrodesis in triple deformity, an effective technique. J Uttaranchal Orthop Assoc 2022;1:32-6

How to cite this URL:
Kurmi AC, Kalia RB, Ansari S, Paul S. Uniplanar monorail fixator for knee arthrodesis in triple deformity, an effective technique. J Uttaranchal Orthop Assoc [serial online] 2022 [cited 2023 Jun 3];1:32-6. Available from: http://www.juoa.org/text.asp?2022/1/1/32/368385

  Introduction Top

Limb reconstruction system (LRS) is a preferred method of choice for limb lengthening as well as to achieve the optimum level of compression in arthrodesis, thus enhancing primary bone healing. Advanced tubercular arthritis resulting in triple deformity of the knee (fixed flexion deformity [FFD], valgus with posterior subluxation of tibia, and external rotation) can be encountered anytime in a TB-prevalent country like ours. Our case is unique in:

  • Advanced tubercular arthritis knee with triple deformity in young active female
  • Monorail fixator uncommon for knee arthrodesis
  • The technique helps in arthrodesis with minimal complications.

  Case Report Top

We are presenting the case of a 30-year-old female who had complaints of pain and swelling over the left knee for 2 years [Figure 1]a and [Figure 1]b. The pain was insidious in onset, gradually progressive for a few months, and then static on and off, associated with low-grade fever, weight loss, and localized swelling of the left knee. There was no history of trauma, multiple joint pain, and morning stiffness. The patient had progressive stiffness and deformity of the left knee for the past 1.5 years. The patient underwent radiological investigations and knee aspiration with findings suggestive of tuberculous (TB) knee. She was started on antituberculous treatment for 6 months with a course completed 1.5 years back. There were no other comorbidities associated with it.
Figure 1: (a) Lateral view of the left knee showing posterior subluxation of the tibia (b) AP view of the left knee with triple deformity. AP: Anterior posterior

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A synovial biopsy was done on October 4, 2021, following which culture and sensitivity were negative for growth, Mycobacterium TB was not detected in the cartridge-based nucleic acid amplification test (CBNAAT) and histopathology showed no evidence of granulomas. Inflammatory markers were negative. Postoperative tissue samples were negative for culture and CBNAAT.


Patient was diagnosed with triple deformity left knee due to advanced tubercular arthritis

The deformity is well appreciated in lateral radiographs [Figure 2]a, [Figure 2]b, [Figure 2]c.
Figure 2: (a) Radiograph of knee lateral view showing flexion deformity at presentation. (b) Radiograph of knee lateral view showing subsequent correction. (c) Radiograph of knee lateral view showing subsequent correction

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At admission, an FFD of 80° was present along with posterior subluxation of the tibia with an externally rotated leg. With 90–90 skeletal (distal tibia) traction in the Balkan frame system – FFD was corrected to 20° before arthrodesis [Figure 3]a and [Figure 3]b. The patient underwent left knee arthrodesis with a uniplanar LRS fixator on November 8, 2021 [Figure 4]a and [Figure 4]b and [Figure 5]a and [Figure 5]b.
Figure 3: (a) Preoperative radiograph left knee AP view. (b) Preoperative radiograph left knee lateral view. AP: Anterior posterior

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Figure 4: (a and b) Intraoperative images showing patella adhered to the underlying bone

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Figure 5: (a and b) Postoperative images of uniplanar rail fixator for knee arthrodesis

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Outcome and follow-up

Postoperatively, the patient had a 3 cm limb length discrepancy as compared to the right side [Figure 6]. The patient is free from pain and is able to ambulate without difficulty using a shoe raise [Video 1].
Figure 6: Postoperative image at 1.5 months follow-up

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Postoperative radiographs on follow-ups show subsequent callus formation and fusion [Figure 7]a and [Figure 7]b and [Figure 8]a, [Figure 8]b, [Figure 8]c. This modality of management met both concerns of the patient.
Figure 7: (a and b) Postoperative radiographs of knee arthrodesis in the same patient

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Figure 8: (a) Postoperative radiograph at 1-month follow-up. (b) Postoperative radiograph at 2-month follow-up showing fusion and callus formation. (c) Postoperative radiograph after pin removal at 3 months

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  Discussion Top

Knee arthrodesis, especially in triple deformity can be managed with external or internal fixation. Internal fixation methods like plating are likely to invite complications like difficulty in wound closure and postoperative infections. Furthermore, the plating may result in prominence or plate protrusion that may add extra discomfort to the patient. Two plates may commonly be required. Intramedullary interlocking nails can provide benefits of early weight-bearing and cosmetically sound but it may have a higher infection rate and may result in the dissemination of underlying infection. Plating may also be combined with the nail.

Hak et al. retrospectively reviewed 36 knee arthrodeses (21 cases infected total knee arthroplasty and one TB joint) performed using an external fixator with an average follow-up of 48 months. Fusion was obtained after the initial procedure in 22 patients (61%). Single and biplane external fixator designs had similar initial fusion rates (single 58% and biplane 65%).[1]

Wiedel suggested successful knee arthrodesis using an external fixation compression device in cases of no severe bone loss. The use of the ultimate external fixator, the Ilizarov device, has improved the success rate of fusion significantly (93%–100%).[2]

Eralp et al. suggested knee arthrodesis using a monolateral external fixator is associated with a high fusion rate and a low complication rate and provides a more comfortable treatment option compared to a circular external fixator. Eleven patients, who underwent knee arthrodesis using a monolateral external fixator between 1999 and 2005, were evaluated retrospectively. Consolidation was achieved in all patients after a mean external fixation time of 8 months (range 5–12 months).[3]

Riouallon et al. followed six cases of the infected knee who underwent complete fusion using a fixation technique combining cross-pinning by two Steinmann pins with a single-frame external fixator at an average of 3.5 months with weight-bearing at 2 to 3 months.[4]

Putman et al. (2013) retrospectively reviewed 31 cases of knee arthrodesis with fixation by a modular intramedullary nail and concluded a higher infection rate. Removal of the fixation material was required in three patients and long-term antibiotic therapy in three patients.[5]

Tang et al. studied 26 patients with end-stage knee TB and concluded that single-stage arthrodesis with a unilateral external fixator combined with cannulated screws can be regarded as efficacious for the treatment of end-stage knee TB. The mean time to radiographic bone fusion was 5.6 months. The primary full union was achieved in 25 patients (96.2%) within 8 months.[6]

Roy et al. treated 24 patients with a single monorail external fixator. All patients developed fusion at an average of 5.4 months with an average limb length discrepancy of 3 cm (1.5–6 cm). He concluded that it is a viable alternative over staged reconstructive procedures or complex arthroplasty for certain individuals.[7]

White et al. in 2018[8] through systematic review and meta-analysis suggested that benefit of external fixation is the ability to perform in the presence of active infection.

In addition, it has the ability to provide a mechanical stimulus for bone formation, simultaneous limb lengthening, and to adjust the alignment of the arthrodesis. The method which is superior in performing an arthrodesis of the knee has not been defined.

Van et al., in 2014, concluded from their study of 18 patients that intramedullary nailing achieved the best fusion rates, but was used most in cases without infection or cured infection. His study data and the contemporary literature suggest that external fixation cannot be regarded as a standard fusion method, but can be used following persisting infection. Although not the standard, but can be one of the best methods considering proper patient selection.[9]

Letartre et al. in 2009 through a retrospective series of 19 patients of infected total knee replacement concluded that good short-term stability, but the risk of failure, not demonstrated over the long-term, of this endoprosthesis encourages us to propose systematic grafting of the arthrodesis area in cases of major bone destruction. This would favor the union of the arthrodesis without causing substantial limb shortening.[10]

External fixation has various advantages. A higher rate of union, less chance of infection, short postoperative time, early weight-bearing, and fewer complications are some advantages that outweigh nailing and plating, especially in thin and young. Some issues such as limb shortening pin tract infection, and cosmetic issues may prevail.

Learning points/Take home message

  • This case report shows an effective technique of knee arthrodesis in case of triple deformity of the knee as sequelae of advanced tubercular arthritis after adequate correction of deformity
  • No signs of postoperative infection and adequate fusion on subsequent postoperative radiographs with no patient complaints are enough to prove as an acceptable technique in young active patients
  • Appropriate patient selection will provide the utmost satisfaction to both patient and clinician.

Patient's perspective

I had a bent knee affecting my daily life. I was unable to carry out small activities without help of other family members. After the treatment, I am able to ambulate on my own and not having pain at the operation site. I am expecting the rods to be removed in few days and continue my activities more extensively. I am having satisfactory outcomes through the way of surgical management.

Informed consent for publication

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

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that her name and initials will not be published and due efforts will be made to conceal her identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Hak DJ, Lieberman JR, Finerman GA. Single plane and biplane external fixators for knee arthrodesis. Clin Orthop Relat Res 1995;(316):134-44.  Back to cited text no. 1
Wiedel JD. Salvage of infected total knee fusion: The last option. Clin Orthop Relat Res 2002;(404):139-42. doi: 10.1097/00003086-200211000-00024.  Back to cited text no. 2
Eralp L, Kocaoğlu M, Tuncay I, Bilen FE, Samir SE. Knee arthrodesis using a unilateral external fixator for the treatment of infectious sequelae. Acta Orthop Traumatol Turc 2008;42:84-9.  Back to cited text no. 3
Riouallon G, Molina V, Mansour C, Court C, Nordin JY. An original knee arthrodesis technique combining external fixator with Steinman pins direct fixation. Orthop Traumatol Surg Res 2009;95:272-7.  Back to cited text no. 4
Putman S, Kern G, Senneville E, Beltrand E, Migaud H. Knee arthrodesis using a customised modular intramedullary nail in failed infected total knee arthroplasty. Orthop Traumatol Surg Res 2013;99:391-8.  Back to cited text no. 5
Tang X, Zhu J, Li Q, Chen G, Fu W, Li J. Knee arthrodesis using a unilateral external fixator combined with crossed cannulated screws for the treatment of end-stage tuberculosis of the knee. BMC Musculoskelet Disord 2015;16:197.  Back to cited text no. 6
Roy AC, Albert S, Gouse M, Inja DB. Functional outcome of knee arthrodesis with a monorail external fixator. Strategies Trauma Limb Reconstr 2016;11:31-5.  Back to cited text no. 7
White CJ, Palmer AJ, Rodriguez-Merchan EC. External fixation versus intramedullary nailing for knee arthrodesis after failed infected total knee arthroplasty: A systematic review and meta-analysis. J Arthroplasty 2018;33:1288-95.  Back to cited text no. 8
Van Rensch PJ, Van de Pol GJ, Goosen JH, Wymenga AB, De Man FH. Arthrodesis of the knee following failed arthroplasty. Knee Surg Sports Traumatol Arthrosc 2014;22:1940-8.  Back to cited text no. 9
Letartre R, Combes A, Autissier G, Bonnevialle N, Gougeon F. Knee arthodesis using a modular customized intramedullary nail. Orthop Traumatol Surg Res 2009;95:520-8.  Back to cited text no. 10


  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8]


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