P.M. van Roermund

Can Ilizarov joint distraction delay the need for an arthrodesis of the ankle? A preliminary report

We applied joint distraction using an Ilizarov apparatus in 11 patients with post-traumatic osteoarthritis of the ankle to try to delay the need for an arthrodesis. Distraction for three months resulted in clinical improvement in pain and mobility for a mean of two years, with an increase in the joint space. We considered that these effects may be produced by the absence of mechanical stress on the cartilage combined with the intra-articular hydrostatic pressures during distraction. We measured these pressures during walking with distraction, and found levels very similar to those reported to improve osteoarthritic cartilage when applied in vitro.

Arthrodesis of the knee after an infected arthroplasty using the Ilizarov method

We treated 15 patients by arthrodesis of the knee after removal of an infected total knee arthroplasty, using an Ilizarov ring fixator. Eight had a failed arthrodesis by another technique. The mean age of the patients was 75 years, the mean duration of retention of the frame was 28 weeks, the mean treatment time 51 weeks, and the mean follow-up 52 months. All but one knee fused at the first attempt, a rate of union of 93%. The incidence of complications related to treatment was 80%. The length of treatment and rates of complication were attributed to advanced age and the adverse local clinical factors in these patients. The Ilizarov method is a promising technique for achieving arthrodesis under these circumstances.

Complications of leg lengthening. 46 procedures in 28 patients.

The results and complications of 46 leg-lengthening procedures in 28 consecutive patients were analyzed retrospectively. There were 24 femoral and 22 tibial lengthenings, performed for short stature (5 patients) and limb-length discrepancy (23 patients). Three methods were used: diaphyseal osteotomy, metaphyseal corticotomy, and distraction physiolysis. In the second group a satisfactory result was obtained more often and a lower complication rate was observed. The overall complication rate was high: 45 substantial problems occurred. We conclude that leg lengthening is difficult, requiring good preoperative examination and planning, and should be carried out only in specialized centers.

The psychological and social functioning of 14 children and 12 adolescents after Ilizarov leg lengthening

We studied the psychological and social impact of the Ilizarov leg lengthening procedure in 26 patients (aged 6-17 years), who had completed the treatment at least 2 months previously. Measurements of depression and anxiety were performed preoperatively and at follow-up. Questions about functioning at school, daily life activities and treatment-related experiences were answered by the patient and his/her parents. The school or work results showed no significant decline during the lengthening procedure. Serious sleeping problems occurred during the procedure. There was no subjective improvement in physical skill after the procedure and almost one-fourth of the children still had complaints about their leg. We conclude that the Ilizarov procedure caused no serious psychological disturbances.

Function of stiff joints may be restored by Ilizarov joint distraction.

Three patients with joint stiffness caused by trauma or infection are reported. The involved joints are the interphalangeal joint of the thumb, patellofemoral joint, and ankle joint. As an alternative for the indicated arthrodesis in these patients, treatment with articulating joint distraction was performed. By use of adapted Ilizarov external ring fixators, gradual distraction was applied to loosen the joint, followed after loosening by a period of exercise during distraction. In all three patients this experimental approach led to a decrease in pain and improvement of joint function that persisted for at least 2 years after treatment. With the use of Ilizarov joint distraction, joint function in cases of joint stiffness may be restored, and the need for an arthrodesis can be postponed.

The use of computed tomography to quantitate bone formation after distraction epiphysiolysis in the rabbit

A study of limb lengthening by distraction epiphysiolysis in the rabbit tibia is presented. For this purpose a special external distraction device was developed, which allowed 10 mm lengthening of the leg. Bone formation in the distraction zone was quantified by means of computed tomography. Cross-sectional scan planes at 1.5 mm separation revealed bone formation proceeding for several weeks after the end of the distraction period. A period of bone remodeling followed, resulting in the formation of a solid cortical structure, similar to the diaphysis, in the distraction zone.

Patient characteristics as predictors of clinical outcome of distraction in treatment of severe ankle osteoarthritis

Osteoarthritis (OA) is a slowly progressive joint disease. Joint distraction can be a treatment of choice in case of severe OA. Prediction of failure will facilitate implementation of joint distraction in clinical practice. Patients with severe ankle OA, who underwent joint distraction were included. Survival analysis was performed over 12 years (n = 25 after 12 years). Regression analyses were used to predict failures and clinical benefit at 2 years after joint distraction (n = 111). Survival analysis showed that 44% of the patients failed, 17% within 2 years and 37% within 5 years after joint distraction (n = 48 after 5 years). Survival analysis in subgroups showed that the percentage failure was only different in women (30% after 2 years) versus men (after 11 years still no 30% failure). In the multivariate analyses female gender was predictive for failure 2 years after joint distraction. Gender and functional disability at baseline predicted more pain. Functional disability and pain at baseline were associated with more functional disability. Joint distraction shows a long‐term clinical beneficial outcome. However, failure rate is considerable over the years. Female patients have a higher chance of failure during follow‐up. Unfortunately, not all potential predictors could be investigated and other clinically significant predictors were not found.

Six weeks of continuous joint distraction appears sufficient for clinical benefit and cartilaginous tissue repair in the treatment of knee osteoarthritis

BACKGROUND Knee joint distraction (KJD) is a surgical joint-preserving treatment in which the knee joint is temporarily distracted by an external frame. It is associated with joint tissue repair and clinical improvement. Initially, patients were submitted to an eight-week distraction period, and currently patients are submitted to a six-week distraction period. This study evaluates whether a shorter distraction period influences the outcome. METHODS Both groups consisted of 20 patients. Clinical outcome was assessed by WOMAC questionnaires and VAS-pain. Cartilaginous tissue repair was assessed by radiographic joint space width (JSW) and MRI-observed cartilage thickness. RESULTS Baseline data between both groups were comparable. Both groups showed an increase in total WOMAC score; 24±4 in the six-week group and 32±5 in the eight-week group (both p<0.001). Mean JSW increased 0.9±0.3mm in the six-week group and 1.1±0.3mm in the eight-week group (p=0.729 between groups). The increase in mean cartilage thickness on MRI was 0.6±0.2mm in the eight-week group and 0.4±0.1mm in the six-week group (p=0.277). CONCLUSIONS A shorter distraction period does not influence short-term clinical and structural outcomes statistically significantly, although effect sizes tend to be smaller in six week KJD as compared to eight week KJD.

THU0440 Clinical Benefit and Cartilaginous Tissue Repair After Knee Joint Distration: 5 Years Follow-Up

Background Placement of a total knee arthroplasty (TKA) in case of end-stage knee osteoarthritis (OA) in young patients is less successful than in elderly, with high revisions rates later in life (1). Recently knee joint distraction (KJD) showed results of clinical improvement and tissue structure modification in patients with knee OA (2) postponing a TKA. The duration of these beneficial effects is yet unclear. Objectives We evaluated whether the clinical improvement and tissue structure modification in knee OA sustain and persist on MRI and X-rays 5 years after distraction. Methods Patients (n=20; <60yrs) with tibio-femoral OA who were resistant to conservative therapy and eligible for TKA, were treated with 8 weeks of KJD by use of an external fixator. Clinical evaluation was performed by WOMAC, VAS pain and survival of the knee joint. Changes in cartilage thickness were quantified by MRI, and change in joint space width (JSW) was evaluated on standardized semi-flexed X-rays. The five-year changes after KJD were evaluated and were compared with the natural progression rate of OA in OsteoArthritis-Initiative participants with similar baseline characteristics. Results From 20 patients (age 49±6 yrs), two withdrew informed consent and three other patients were treated with TKP (after three and four years), so the survival of the knee joint was 80% at 5 years. Moreover, there was persistent clinical improvement compared to baseline sustaining over time: Δ WOMAC +21,1 points (CI:8,9-33,3; p=0.002), Δ VAS pain -27,6mm (CI:-13,3-42,0; p<0.001). In addition, minimum radiographic JSW was increased at five years as compared to pre-treatment values: Δ+0,43mm (CI:0,02-0,84; p=0.040). Taking natural loss of cartilage thickness into account, this change was significantly different from the changes as a result of extrapolated natural progression (Δ-0,39mm and Δ-0,18mm, respectively) resulting at 5 years in a difference of +0,65mm (CI:0,07-1,23; p=0.031) and of +0,41mm (CI:0,07-0,74; p=0.020) for mean JSW on X-ray and average cartilage thickness on MRI, respectively. Conclusions In young OA patients, TKA can be postponed for at least five years in 80% of the patients. KJD treatment results in persistent clinical benefit and an increase in cartilage thickness and JSW. The effects were not as strong as observed 1 and 2 years after treatment, still they represented a significant structural benefit compared to the natural course of the disease. Joint distraction has great potential to effectively postpone TKA and as such represents a promising therapeutic option for young patients with severe knee OA. References Julin J, Jamsen E, Puolakka T,et al. Younger age increases the risk of early prosthesis failure following primary total knee replacement for osteoarthritis. A follow-up study of 32,019 total knee replacements in the Finnish Arthroplasty Register. Acta orthopaedica. 2010;81(4):413-9. Wiegant K, van Roermund PM, et al. Sustained clinical and structural benefit after joint distraction in the treatment of severe knee osteoarthritis. Osteoarthritis and cartilage/OARS, Osteoarthritis Research Society. 2013 Nov;21(11):1660-7. PubMed PMID: 23954704. Acknowledgements This study was supported by the Dutch Arthritis Foundation. Disclosure of Interest None declared

THU0442 Knee Joint Distraction Compared with Total Knee Prosthesis: A Randomized Controlled Trial (Preliminary Results)

Background Placement of a total knee prosthesis (TKP) in case of end-stage knee OA in young patients is less successful than in the elderly, with high revision rates of up to 44% later in life. [1,2] However, in severe end-stage knee OA, effective joint saving treatments are scarce. Recently, knee joint distraction (KJD) showed results of clinical improvement and cartilaginous tissue repair in patients with knee OA. [3] However, no comparative data on efficacy is available. A RCT was set out and determined whether there was a clinical relevant difference between KJD and TKP in clinical outcome 1-year after treatment. Methods 60 patients with severe knee osteoarthritis were included and randomized to KJD (20 patients) or TKP (40 patients). As clinical outcome parameter a WOMAC questionnaire (100 being the best) and a VAS Pain (0 mm being the best) were assessed at baseline (BL) and 12 months. Off all values mean ± SEM is given. Results 26 patients, who received a TKP, had at least one-year of follow-up and of the patients who received KJD 16 at least one-year of follow-up available at the cut-off date (December 31st 2014). The 26 patients in the TKP group had a mean age at surgery of 54.8±1.2, a mean BMI of 29.6±0.7 kg/m2 and a mean Kellgren & Lawrence grade of 2.7±0.1. The 16 patients in the KJD group had a mean age at surgery of 57.1±1.8, a mean BMI of 26.8±1.0 and a mean Kellgren & Lawrence grade of 3.6±0.2. Total WOMAC scores demonstrated significant clinical improvement in both groups (see also figure 1). The KJD group increased from 50±3 points at BL to 80±4 points at 1-year (p<0.001). Similarly, the TKP group had a score of 47±3 points at BL, which increased to 82±3 points (p<0.001). Parallel results were seen for the three subscales of the WOMAC (stiffness, pain and function) and for the VAS. None of the parameters showed a statistical significant difference between the two groups at 1-year (p=0.730 for WOMAC total and p=0.116 for the VAS). Conclusions KJD does not lead to a clinical relevant difference in outcome compared with TKP after 1-year. Importantly KJD preserves the knee-joint and therefore represents a promising therapeutic option for young patients with severe knee OA. References Julin J, Jamsen E, Puolakka T, Konttinen YT, Moilanen T. Younger age increases the risk of early prosthesis failure following primary total knee replacement for osteoarthritis. A follow-up study of 32,019 total knee replacements in the Finnish Arthroplasty Register. Acta orthopaedica. 2010;81(4):413-9. Kurtz SM, Lau E, Ong K, Zhao K, Kelly M, Bozic KJ. Future young patient demand for primary and revision joint replacement: national projections from 2010 to 2030. Clinical orthopaedics and related research. 2009;467(10):2606-12. Wiegant K, van Roermund PM, Intema F, Cotofana S, Eckstein F, Mastbergen SC, et al. Sustained clinical and structural benefit after joint distraction in the treatment of severe knee osteoarthritis. Osteoarthritis and cartilage/OARS, Osteoarthritis Research Society. 2013;21(11):1660-7. Acknowledgements ZonMw (The Netherlands Organisation for Health Research and Development) and the Dutch Arthritis Association support this study. Disclosure of Interest None declared