Karen Wiegant1*, Peter van Roermund2, Ronald van Heerwaarden3, Sander Spruijt3, Roel Custers2, Natalia Kuchuk1, Simon Mastbergen1, Floris Lafeber1
1Rheumatology & Clinical Immunology, University Medical Center Utrecht, Utrecht, the Netherlands
2Department of Orthopedics, University Medical Center Utrecht, Utrecht, the Netherlands
3Department of Orthopedics, Maartensclinic Woerden, Woerden, the Netherlands
Received: 15 July, 2015; Accepted: 03 November, 2015; Published: 05 November, 2015
Karen Wiegant, University Medical Center Utrecht, Rheumatology and Clinical Immunology, Utrecht, The Netherlands, Tel: +31887559428; E-mail:
Wiegant K, van Roermund P, van Heerwaarden R, Spruijt S, Custers R, et al. (2015) Total Knee Prosthesis after Knee Joint Distraction Treatment. J Surg Surgical Res 1(3): 066-071. 10.17352/2455-2968.000016
© 2015 Wiegant K et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Osteoarthritis; Joint distraction; Cartilage; Total knee prosthesis; Infection
Background and purpose: During knee joint distraction (KJD) treatment, using an external fixation-frame, pin-tract infections frequently occur. These local skin infections, although treated successfully with oral antibiotics, might lead to latent infections. This raises concern about subsequent placement of a total knee prosthesis (TKP). This study evaluates the first five cases in which patients had to be treated with TKO after KJD failure.
Patients and methods: An overall survival analysis of the first 26 patients treated with KJD revealed five failures, because of declining efficacy over time. These patients were treated with TKP. Complications of these TKPs are described and all cases were compared with age and gender matched primary-TKP-controls. WOMAC and VAS pain scores were assessed before and after TKP treatment.
Results: The mean survival time of the five KJD before TKP was 61 ± 15 months (range 45-84 months). No peri-operative complications were registered and none of the patients suffered from an infection post-TKP. There were no differences between baseline characteristics of patients with primary TKP compared to those with TKP after KJD except for a higher VAS pain score (p<0.02) for primary TKP. Mean follow-up after TKP was 21 ± 12 months (range 9-39 months). Efficacy after TKP was similar for patients with primary TKP compared to those with TKP after KJD.
Conclusion: Based on the first five cases it appears safe to treat patients several years after KJD with a TKP. There is no indication these patients have a higher infection risk and post-operative outcome is comparable with primary TKP.
Osteoarthritis (OA) is a degenerative joint disorder affecting all joint tissues . Patients suffer from pain and impaired joint function. In most cases mechanically and metabolically induced ‘wear-and-tear’ of the articular cartilage results in loss of joint space width as measured on radiographs. Finally in end-stage disease placement of a total joint prosthesis is often the last remaining treatment option. In case of knee OA total replacement is not recommended in patients under 65 years of age, because of the limited life span of the prosthesis of approximately 15-20 years . Nonetheless over 40% of the knee replacements are performed under the age of 65 years . Furthermore, it is shown that patients treated <65 years of age need significantly earlier revision of the total knee prosthesis (TKP) expectedly because of their more active life-style , although literature is not consistent on this .
Because of the increased risk for revision surgery it is recommended to treat patients <65 years of age with (partial) joint preserving treatments like high tibial osteotomy (HTO) , unicompartmental knee prosthesis (UKP) , or knee joint distraction (KJD) [8,9]. These treatments decrease pain and improve function, and can postpone a first TKP when eventually necessary. For HTO the overall survival rate is about 90% after five years, and 70% after ten years before complaints return and subsequent treatment is necessary [10,11]. For UKP, being a more definitive treatment for unicompartmental OA [12,13], survival rate is 93% after four years and 87% after eight years, although data are still scarce .
In general outcome after a TKP is influenced by previous joint preservation knee surgery , however, results of a TKP after HTO in general appear to be good. In a systematic review published by van Raaij et al. , it was reported that there are no statistically significant differences between patient related outcome scores (PROMs) of primary placed TKP’s and TKP’s secondary placed after HTO treatment. Furthermore no differences with regard to aseptic loosening, deep infections or additional treatment necessities were found.
In case of conversion from the partial joint preserving option UKP into TKP (mostly in case of aseptic loosening) there is eventually a higher revision risk of the TKP in comparison with a primary TKP within the first five years . The re-revision rate after conversion from UKP to TKP were reported to range from 4-14% . Reason for re-revision were unfortunately not further specified. Six-month postoperative scores for patient’s function after conversion from UKP to TKP were statistically significant poorer in comparison with conversion from HTO to TKP .
Besides HTO and UKP, other surgery prior to TKP has been described to increase the risk for infection and as a consequence the risk for revision surgery. These surgeries includes open and closed reduction and stabilization of a tibiaplateau fracture , previous operation around the knee joint, previous non-arthroscopic surgery, and previous open reduction and internal fixation (ORIF) around the knee joint .
KJD is a relatively new treatment in which the tibio-femoral joint is distracted about five millimeters with the use of an external fixation frame during six to eight weeks. KJD results in prolonged clinical benefit and cartilage tissue repair on radiographs and magnetic resonance images . One major complication, as seen for external fixators in general , is pin-tract infections. In general, all clinical signs of infections end shortly after the external fixation frame is removed. Irrespectively, thus far, more than three quarter of the patients suffered from one or more pin-tract infections due to joint distraction in treatment of osteoarthritis . In that respect, it is comprehensible that concerns rise about infection risks and overall outcome of TKP after KJD. However, to the best of our knowledge, no literature is available on the influence on surgery in the same area, after treatment with an external fixator, in terms of e.g. latent infection risks. As such, it is important to know if KJD affects subsequent TKP treatment.
In this study we evaluated peri-operative complications (infections) and clinical outcome of patients that underwent TKP after eventually failure of KJD, in comparison to age- and gender-matched patients receiving a primary TKP.
In this level III case-control study, twenty-six patients (average age 48,3±6,2 years, range 32-57 years) with end-stage knee OA and initially indicated for a TKP, because of persistent pain and loss of function and with clear radiographic joint damage, not adequately responding to conventional treatments, were treated with KJD between 2002 and 2008 (Department of Orthopedics, University Medical Center Utrecht (UMCU); six patients from a feasibility study and 20 patients from a prospective follow-up study [8,9]). From these 26 patients three patients refused to co-operate in further follow-up; one directly after KJD treatment, the other two patients after two years of follow-up. At inclusion all patients were under 60 years of age, had a VAS pain score of >60mm, and radiographic signs of primarily tibio-femoral OA joint damage (for inclusion details see 8).
During follow-up, five out of these 26 patients had to be treated with a TKP because of insufficient patient’s satisfaction several years after the KJD treatment. For each of these five TKP after KJD cases, two age (at time of TKP) and gender matched-controls with primary TKP were selected from an ongoing randomized controlled clinical trial . In this trial patients were randomized between TKP and KJD. This means that these primary TKP patients were on average comparable to those whom were treated with KJD as they fitted the inclusion criteria for randomization. Inclusion criteria have not been changed significantly over all KJD studies over the last years [8,24], and in principle comprises end stage knee osteoarthritis considered for TKP. Because the TKP after KJD group considered only five patients we matched them in a 1:2 ratio with primary TKP patients, for gender and as good as possible for age and follow-up time after TKP, blinded for clinical outcome at follow-up.
Both abovementioned studies were approved by the Medical Ethical Committee of the UMCU; (No. 01/046; No.04/086; and No.10/359), and all patients gave written informed consent. Patient characteristics of all cases (n=5) and matched-controls (n=10) are depicted in Table 1.
Joint distraction method
The distraction method was applied as previously described [8,9]. In short, an external fixation frame consisting of two monotubes with internal coil springs was placed, bridging the knee joint. Each monotube was fixed to two bone pins on each end and. In stages, the knee was distracted for five mm (confirmed by radiographs). After instructions about pin site care, daily exercise, and physical therapy, the patients were discharged from the hospital. Patients were allowed and encouraged to load the distracted joint with full weight-bearing, supported with crutches if needed. In case of superficial (skin) pin tract infections, treatment with oral antibiotics for 5-7 days was provided (Flucloxacillin). Every 2 weeks the patients returned to the hospital and the monotubes were temporarily removed. The knee was bent, for 3-4hrs, in a continuous passive motion device, with pain at the pin sites determining the maximum degree of flexion; on average, 25° (15°-80°) flexion and full extension was reached. The monotubes were replaced and sufficient distraction was confirmed by a radiograph and adjusted if needed. After 2-3 months (average duration 60±5 days, range 54-77 days), the tubes and pins were surgically removed and patients went home without imposed functional restrictions. After both surgeries, patients were treated with acetaminophen and NSAID when needed, according to a standard analgesia protocol. Upon discharge, pain medication and additional treatments along with daily exercise and physical therapy were regulated by the patient and its physician and not documented.
Total knee prosthesis
For the five cases, TKPs were placed in other hospitals, in regular care. No specific information about prosthesis type or rehabilitation protocols was available. These five patients were interviewed in retrospect. During these interviews it appeared that rehabilitation was quite similar to the rehabilitation of the ten matched-controls.
All matched-controls were treated according to the RCT-protocol . The whole joint was substituted with a posterior stabilized femur and tibia component of the Genesis II model (Smith and Nephew). After fixation with Genta Palacos® cement the definite insert was placed in between the components. After an average hospitalization of 6 days, with 2 days of CPM (continuous passive motion) exercise, patients were discharged and advised to regain gradually full weight bearing guided by a physiotherapist. After 6 weeks the stability of the knee was examined, clinically and radio graphically.
All peri-operative complications (including wound healing problems and actual wound infections) were deduced in retrospect from patients’ clinical charts until six weeks after TKP surgery, as they were not part of any protocol follow-up.
Patient related outcome scores (PROMs)
Except for the first three feasibility patients, patients were scored for clinical outcomes twice at baseline and post-operative at 3, 6, 9, 12, 18, 24 months follow-up. After two years the follow-up took place yearly until 10 years of follow-up was reached. The first three feasibility patients were followed prospectively for only one year. For the present study these patients were interviewed once again for a clinical status praesens. Clinical outcome parameters included pain, stiffness, and function, measured with the WOMAC questionnaire (version 3.0, normalized to a 100-point scale for total and subscales; 100 being the best score) and VAS pain (visual analogue score; 0 being the best score).
A Kaplan-Meier survival analysis was made, to evaluate the preservability of KJD treatment, until a TKP was placed.
Pooled baseline PROMs of the five KJD cases that underwent TKP were compared with the whole KJD cohort (n=23) and with baseline values of the matched-controls with primary TKP (n=10). Furthermore the last regular PROM measurements of the cases before receiving a TKP (defined: pre-TKP PROMs; n=5) were compared with baseline data of the matched-controls with primary TKP (n=10). These three analyses were done (non-parametrically, unpaired) with a Mann-Whitney-U test, using IBM SPSS Statistics version 20. Per follow-up time-point a comparison is graphically shown per case with the two matched-controls, without statistical evaluation, due to low n-values.
From the cohort a total of five patients received secondary a TKP, after first been treated with KJD. The mean survival time of KJD of these five patients was 61±15 months, range 45-84 months (survival curve shown in Figure 1).