Original Article
Does Cast Immobilization Contribute to Posterior Stability After Posterior Cruciate Ligament Reconstruction?

https://doi.org/10.1016/j.arthro.2012.10.019Get rights and content

Purpose

The purpose of this study was to confirm the contribution of long leg cast immobilization to posterior stability after reconstruction of isolated posterior cruciate ligament (PCL) injuries.

Methods

Of 84 patients who underwent arthroscopic PCL reconstruction between November 2006 and December 2009, 44 patients were randomly assigned to 2 groups and analyzed prospectively. For 22 patients (the cast group), long leg cast immobilization was applied until postoperative week 5 and then a 0° locking brace was worn until week 12. Full weight bearing was allowed immediately after operation. For the other 22 patients (the brace group), only a 0° locking brace was applied until postoperative week 12 without cast immobilization. Range of motion (ROM), clinical scores, Telos device (Telos, Marburg, Germany) posterior stress radiographic assessment results and International Knee Documentation Committee (IKDC) grades of both groups were analyzed preoperatively and at postoperative years 1 and 2.

Results

The mean preoperative side-to-side difference on Telos posterior stress radiographs was 11.3 ± 2.5 mm in the cast group and 12.7 ± 2.1 mm in the brace group, revealing no differences between the 2 groups (P = .743), but postoperatively the mean difference measured 2.5 ± 1.9 mm and 4.8 ± 2.4 mm, respectively, showing a significantly smaller difference in the cast group (P = .004); the improvement was 8.8 mm and 7.9 mm, respectively, and was statistically significant (P = .021). Preoperative IKDC grades were not different between the 2 groups (P > .05), but 2 years postoperatively, the cast group showed a significantly better distribution of grades (P = .012). The mean ROM, Lysholm scores, IKDC subjective scores, and Tegner scores 2 years postoperatively were not significantly different between the 2 groups (P > .05).

Conclusions

The patients immobilized with long leg casts until 5 weeks after PCL reconstruction showed significantly better results in Telos posterior stress radiographs and distribution of IKDC grades 2 years postoperatively and did not show limited ROM when compared with the patients who wore braces only. However, IKDC subjective scores were not found to be different between the 2 groups.

Level of Evidence

Level I, prospective randomized comparative study.

Section snippets

Methods

This study was conducted after obtaining approval from the hospital ethics committee at our institution, and all the related information was explained to the patients in advance. The inclusion criterion for this study was chronic PCL injury that showed grade III instability by the posterior drawer test. Exclusion criteria were patients with fractures, associated ligament injury, multiple ligament injury, associated meniscus tear or meniscus transplantation on the affected side; patients who had

Results

The selected characteristics of the 44 patients are described in Table 2.

Discussion

This study aimed at suggesting a rehabilitation program that prevents excessive tension and relaxation of a tendon graft through long leg cast immobilization to restore stability and function of the knee after PCL reconstruction.4, 6, 7 We expected that applying long leg cast immobilization with the patient in a prone position would prevent posterior tibial sagging and that full weight bearing would shift the tibia anteriorly, reducing stress on the tendon graft and further limiting ROM. This

Conclusions

Immobilization with long leg casts until 5 weeks after PCL reconstruction yielded significantly better results in Telos posterior stress radiographs and distribution of IKDC grades 2 years postoperatively and did not show limited ROM when compared with the patients who wore braces only. However, IKDC subjective scores were not found to be different between the 2 groups.

References (29)

Cited by (17)

  • The Clinical Outcome of Arthroscopic Versus Open Popliteal Tendon Reconstruction Combined With Posterior Cruciate Ligament Reconstruction in Patients With Type A Posterolateral Rotational Instability

    2019, Arthroscopy - Journal of Arthroscopic and Related Surgery
    Citation Excerpt :

    We have observed that several risk factors, such as early initiation and rapid progression of ROM, high flexion angle, and early full weightbearing, have disadvantageous effects on the PCL graft. As described by Yoon et al.,25 at 5 weeks postoperatively, the cast was removed and a 0° locking brace was applied until 12 weeks postoperatively. When the cast was removed, gradual ROM was performed, starting with closed-kinetic-chain squats to achieve 90° flexion at 8 weeks, 120° flexion at 3 months, and full flexion at 6 months.

  • Posterior Cruciate Ligament Injuries: Diagnosis, Operative Techniques, and Clinical Outcomes

    2017, Noyes' Knee Disorders: Surgery, Rehabilitation, Clinical Outcomes
  • Biomechanical evaluation of a novel dynamic posterior cruciate ligament brace

    2016, Clinical Biomechanics
    Citation Excerpt :

    To achieve this position, the recommended treatment algorithm uses a rigid brace or cast immobilization with a posterior tibial splint for the first 5–8 weeks (Edson et al., 2010; Jung et al., 2008; Kim et al., 2013), since applying an anteriorly directed force to the tibia during PCL healing has been reported to improve the clinical outcome (Strobel et al., 2002; Ahn et al., 2011; Jacobi et al., 2010). After this initial healing period, a 6- to 8-week period follows with a second brace that allows an adjustable range of motion (Edson et al., 2010; Jung et al., 2008; Yoon et al., 2013). Initial prolonged rigid brace or cast immobilization during the healing period can cause knee joint stiffness, reduce muscle strength, and result in impairment of knee joint function.

  • Comparison of single-bundle and double-bundle isolated posterior cruciate ligament reconstruction with allograft: A prospective, randomized study

    2014, Arthroscopy - Journal of Arthroscopic and Related Surgery
    Citation Excerpt :

    In deep flexion of the knee, the PM bundle is taut again.10 SB PCL reconstruction, in which only the AL bundle is reconstructed, has shown good results.11-13 Without the support of the PM bundle, reconstruction of the AL bundle is insufficient to reproduce the function of the native PCL, which is lengthened because of cyclic fatigue.

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Supported by a research grant from Smith & Nephew, Andover, MA.

The authors report that they have no conflicts of interest in the authorship and publication of this article.

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