Ankle joint distraction is a promising alternative treatment for patients with severe haemophilic ankle arthropathy.

INTRODUCTION: Haemophilic ankle arthropathy (HAA) causes major morbidity. When conservative treatment fails, major surgical interventions are indicated. An alternative treatment to maintain joint mobility and postpone these interventions is desired. AIM: To gather prospective data on clinical/structural changes after ankle joint distraction (AJD) in HAA. METHODS: This study includes patients with severe HAA insufficiently responding to conservative treatment. AJD was performed during 8-10 weeks by use of an external frame. Questionnaires, physical examination and radiology were used to evaluate pain, function and structural changes before and 6, 12, 24 and 36 months after distraction. Mixed effect models were used for analysis. RESULTS: This study includes eight cases (21-53 years). The fixed effects estimates of the visual analogue score (0-10) improved from 7.5 at baseline to 3.4 (p = .023) 3 years after distraction. The Haemophilia Activities List (HAL, 0-100) for basic/complex lower extremities functions improved from respectively 29.6 and 31.5 to 54.3 (p = .015) and 50.7 (p = .031). Joint mobility was maintained. Magnetic resonance imaging (MRI) showed thickened cartilage and reduced bone marrow oedema and subchondral cysts. Pin tract infections (n = 6) were effectively treated and no adverse bleeding events occurred. At 3-year follow-up, in none of the patients the originally indicated arthrodesis was performed. CONCLUSION: This first prospective study showed that AJD in HAA results in decreased pain, improved function and decreased arthropathy-related MRI findings in the majority of patients for prolonged time. Although the study population is small and follow-up is relatively short, AJD may be promising to postpone invalidating interventions and might be a breakthrough treatment.

Tissue structure modification in knee osteoarthritis by use of joint distraction: an open 1-year pilot study.

BACKGROUND: Modification of joint tissue damage is challenging in late-stage osteoarthritis (OA). Few options are available for treating end-stage knee OA other than joint replacement. OBJECTIVES: To examine whether joint distraction can effectively modify knee joint tissue damage and has the potential to delay prosthesis surgery. METHODS: 20 patients (<60 years) with tibiofemoral OA were treated surgically using joint distraction. Distraction (~5 mm) was applied for 2 months using an external fixation frame. Tissue structure modification at 1 year of follow-up was evaluated radiographically (joint space width (JSW)), by MRI (segmentation of cartilage morphology) and by biochemical markers of collagen type II turnover, with operators blinded to time points. Clinical improvement was evaluated by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Visual Analogue Scale (VAS) pain score. RESULTS: Radiography demonstrated an increase in mean and minimum JSW (2.7 to 3.6 mm and 1.0 to 1.9 mm; p<0.05 and <0.01). MRI revealed an increase in cartilage thickness (2.4 to 3.0 mm; p<0.001) and a decrease of denuded bone areas (22% to 5%; p<0.001). Collagen type II levels showed a trend towards increased synthesis (+103%; p<0.06) and decreased breakdown (-11%; p<0.08). The WOMAC index increased from 45 to 77 points, and VAS pain decreased from 73 to 31 mm (both p<0.001). CONCLUSIONS: Joint distraction can induce tissue structure modification in knee OA and could result in clinical benefit. No current treatment is able to induce such changes. Larger, longer and randomised studies on joint distraction are warranted.

Five-Year Follow-up of Knee Joint Distraction: Clinical Benefit and Cartilaginous Tissue Repair in an Open Uncontrolled Prospective Study.

Objective In end-stage knee osteoarthritis, total knee arthroplasty (TKA) may finally become inevitable. At a relatively young age, this comes with the risk of future revision surgery. Therefore, in these cases, joint preserving surgery such as knee joint distraction (KJD) is preferred. Here we present 5-year follow-up data of KJD. Design Patients ( n = 20; age <60 years) with conservative therapy resistant tibiofemoral osteoarthritis considered for TKA were treated. Clinical evaluation was performed by questionnaires. Change in cartilage thickness was quantified on radiographs and magnetic resonance images (MRI). The 5-year changes after KJD were evaluated and compared with the natural progression of osteoarthritis using Osteoarthritis Initiative data. Results Five-years posttreatment, patients still reported clinical improvement from baseline: ΔWOMAC (Western Ontario and McMaster Universities Arthritis Index) +21.1 points (95% CI +8.9 to +33.3; P = 0.002), ΔVAS (visual analogue scale score) pain -27.6 mm (95%CI -13.3 to -42.0; P < 0.001), and minimum radiographic joint space width (JSW) of the most affected compartment (MAC) remained increased as well: Δ +0.43 mm (95% CI +0.02 to +0.84; P = 0.040). Improvement of mean JSW (x-ray) and mean cartilage thickness (MRI) of the MAC, were not statistically different from baseline anymore (Δ +0.26 mm; P = 0.370, and Δ +0.23 mm; P = 0.177). Multivariable linear regression analysis indicated that KJD treatment was associated with significantly less progression in mean and min JSW (x-ray) and mean cartilage thickness (MRI) compared with natural progression (all Ps <0.001). Conclusions KJD treatment results in prolonged clinical benefit, potentially explained by an initial boost of cartilaginous tissue repair that provides a long-term tissue structure benefit as compared to natural progression. Level of evidence, II.

Evidence of cartilage repair by joint distraction in a canine model of osteoarthritis.

OBJECTIVE: Knee osteoarthritis (OA) is a degenerative joint disorder characterized by cartilage, bone, and synovial tissue changes that lead to pain and functional impairment. Joint distraction is a treatment that provides long-term improvement in pain and function accompanied by cartilage repair, as evaluated indirectly by imaging studies and measurement of biochemical markers. The purpose of this study was to evaluate cartilage tissue repair directly by histologic and biochemical assessments after joint distraction treatment. METHODS: In 27 dogs, OA was induced in the right knee joint (groove model; surgical damage to the femoral cartilage). After 10 weeks of OA development, the animals were randomized to 1 of 3 groups. Two groups were fitted with an external fixator, which they wore for a subsequent 10 weeks (one group with and one without joint distraction), and the third group had no external fixation (OA control group). Pain/function was studied by force plate analysis. Cartilage integrity and chondrocyte activity of the surgically untouched tibial plateaus were analyzed 25 weeks after removal of the fixator. RESULTS: Changes in force plate analysis values between the different treatment groups were not conclusive. Features of OA were present in the OA control group, in contrast to the generally less severe damage after joint distraction. Those treated with joint distraction had lower macroscopic and histologic damage scores, higher proteoglycan content, better retention of newly formed proteoglycans, and less collagen damage. In the fixator group without distraction, similarly diminished joint damage was found, although it was less pronounced. CONCLUSION: Joint distraction as a treatment of experimentally induced OA results in cartilage repair activity, which corroborates the structural observations of cartilage repair indicated by surrogate markers in humans.

Clinical benefit of joint distraction in the treatment of ankle osteoarthritis.

Irrespective of underlying mechanisms, the structural changes after joint distraction and the efficacy during several years validate the concept of joint distraction in the treatment of osteoarthritis. Therefore, joint distraction in the case of severe ankle osteoarthritis at relatively young age may be a treatment of choice. In the light of increased aging, and the limited life span of an endoprosthesis, evaluation of joint distraction in the case of knee and hip osteoarthritis is justified.

Joint distraction as an alternative for the treatment of osteoarthritis.

Irrespective of underlying mechanisms, the long-term efficacy of joint distraction in the treatment of severe ankle osteoarthritis at young age validates the concept of joint distraction in the treatment of osteoarthritis. Therefore, joint distraction in the case of severe ankle osteoarthritis may be a treatment of choice. This opens the possibility to study joint distraction as a treatment for other joints. Because knee osteoarthritis is much more common, it is a much greater social and economic problem. Beneficial effects of joint distraction in the case of ankle osteoarthritis, and specifically in the treatment of more common forms of osteoarthritis such as severe knee and hip osteoarthritis, may therefore have a great impact, especially in view of the increasing age of our population.

Paediatric lower limb deformity correction using the Ilizarov technique: a statistical analysis of factors affecting the complication rate.

Limb length discrepancy (LLD) and other patient factors are thought to influence the complication rate in (paediatric) limb deformity correction. In the literature, information is conflicting. This study was performed to identify clinical factors that affect the complication rate in paediatric lower-limb lengthening. A consecutive group of 37 children was analysed. The median proportionate LLD was 15 (4-42)%. An analysis was carried out on several patient factors that may complicate the treatment or end result using logistic regression in a polytomous logistic regression model. The factors analysed were proportionate LLD, cause of deformity, location of corrected bone, and the classification of the deformity according to an overall classification that includes the LLD and all concomitant deformity factors. The median age at the start of the treatment was 11 (6-17) years. The median lengthening index was 1.5 (0.8-3.8) months per centimetre lengthening. The obstacle and complication rate was 69% per lengthened bone. Proportionate LLD was the only statistically significant predictor for the occurrence of complications. Concomitant deformities did not influence the complication rate. From these data we constructed a simple graph that shows the relationship between proportionate LLD and risk for complications. This study shows that only relative LLD is a predictor of the risk for complications. The additional value of this analysis is the production of a simple graph. Construction of this graph using data of a patient group (for example, your own) may allow a more realistic comparison with results in the literature than has been possible before.

[Trends in the number of knee and hip arthroplasties: considerably more knee and hip prostheses due to osteoarthritis in 2030]. / Trends in aantallen knie- en heupartroplastieken: de vraag naar knie- en heupprotheses blijft voorlopig toenemen.

OBJECTIVE: To predict the future number of knee and hip arthroplasties due to osteoarthritis (OA) in the Netherlands based on historical trends and demographic projections. DESIGN: Data analysis and model calculations. METHOD: Two future projections were based on age and sex-specific number of hospital admissions for the placement of total knee or hip prostheses due to OA between 1995 and 2005; data were obtained from the Dutch National Medical Registration (LMR). The demographical projection was based on the incidence of arthroplasty in 2005 combined with demographic predictions from Statistics Netherlands regarding the time period between 2005 and 2030. The trend projection used the trend in the age and sex-specific incidence of surgery between 1995 and 2005. RESULTS: Between 1995 and 2005, the annual number of knee arthroplasties in patients with a primary diagnose of OA increased from 4,916 to 14,565, an increase of 196%. The total number of hip arthroplasties increased from 13,785 to 20,715, an increase of 50%. The demographical projection suggests that the number of total hip arthroplasties will increase to 31,731 by 2030, an increase of 53%, and the number of knee arthroplasties to 22,183. The trend projection suggests that the numbers may increase to 51,680 for the hip (+149%) and to 57,893 for the knee (+297%). CONCLUSION: The increase in the number of knee and hip arthroplasties due to OA will probably continue in the coming 20 years. The following developments will probably contribute to this: demographical changes, the increase in overweight, improved long-term outcomes of arthroplasty, more active lifestyle of the elderly and the increasing number of orthopaedic surgeons.

Lower limb deformity due to failed trauma treatment corrected with the Ilizarov technique: factors affecting the complication rate in 52 patients.

BACKGROUND AND PURPOSE: Failed treatment of fractures may be corrected by the Ilizarov technique but complications are common. In 52 patients with compromised healing of femoral and tibial fractures, the results of secondary reconstruction with Ilizarov treatment were investigated retrospectively in order to identify the factors that contribute to the risk of complications. METHODS: 52 consecutive patients was analyzed. The median interval between injury and secondary reconstruction was 3 (0.1-27) years. The patients had failed fracture treatment resulting in bone defects, pseudarthrosis, infection, limb length discrepancy (LLD) caused by bone consolidation after bone loss, malunion, soft-tissue loss, and stiff joints. Most patients had a combination of these deformities. The results were analyzed by using logistic regression in a polytomous universal mode (PLUM) logistic regression model. RESULTS: The median treatment time was 9 (4-30) months, and the obstacle and complication rate was 105% per corrected bone segment. In 2 patients treatment failed, which resulted in amputation. In all other patients healing of nonunion could be established, malunion could be corrected, and infections were successfully treated. The statistical analysis revealed that relative bone loss of the affected bone was the only predictor for occurrence of complications. From these data, we constructed a simple graph that shows the relationship between relative bone loss of the affected bone and risk of complications. INTERPRETATION: Relative bone loss of the affected bone segment is the main predictor of complications after Ilizarov treatment of previously failed fracture treatment. The visualization of the analysis in a simple graph may assist comparison of the complication rates in the literature.

Growth rate after limb deformity correction by the Ilizarov method with or without knee joint distraction: lengthening in 30 children followed for at least 2 years.

BACKGROUND AND PURPOSE: Growth inhibition and stimulation have both been reported after juvenile limb lengthening. Distraction of a joint usually suspends and unloads the growth plate and may stimulate growth. We investigated the influence of knee joint distraction on the speed of growth after limb lengthening. METHODS In a retrospective study, growth patterns were analyzed in 30 children mean 61 (24-109) months after limb lengthening with the Ilizarov method, each child having more than 2 years of remaining growth. In 14 patients with knee joint instability, the knee was bridged over during lengthening for joint stabilization. Whether or not joint bridging and distraction would affect patterns of growth of the lengthened limb by unloading the growth plate was evaluated with a repeated measurements analysis of variance. RESULTS: After lengthening procedures, the proportionate leg-length discrepancy was found to decrease in 16 children, suggesting increased growth rate in the lengthened limbs. A statistically significantly faster growth rate was seen in 8 of 14 patients with knee distraction as compared to patients with single bone frame configurations. INTERPRETATION: Further research is required to investigate whether growth stimulation is due to the surgical technique and whether joint distraction should be recommended during limb lengthening in growing children.

Unloading joints to treat osteoarthritis, including joint distraction.

PURPOSE OF REVIEW: Patients are increasingly becoming interested in nonpharmacologic approaches to manage their osteoarthritis. This review examines the recent literature on the potential beneficial effects of unloading joints in the treatment of osteoarthritis, with a focus on joint distraction. RECENT FINDINGS: Mechanical factors are involved in the development and progression of osteoarthritis. If "loading" is a major cause in development and progression of osteoarthritis, then "unloading" may be able to prevent progression. There is evidence that unloading may be effective in reducing pain and slowing down structural damage. This review describes unloading by footwear and bracing (nonsurgical), unloading by osteotomy (surgical), and has a focus on unloading by joint distraction. Excellent reviews in all these three fields have been published over the past few years. Recent studies argue for the usefulness of a biomechanical approach to improve function and possibly reduce disease progression in osteoarthritis. SUMMARY: To improve patient function and possibly reduce disease progression, a biomechanical approach should be considered in treating patients with osteoarthritis. Further research (appropriate high-quality clinical trials) and analysis (clinical as well as preclinical and fundamental) are still necessary, however, to understand, validate, and refine the different approaches of unloading to treat osteoarthritis.

The canine 'groove' model of osteoarthritis is more than simply the expression of surgically applied damage.

OBJECTIVE: Recently a new canine model of osteoarthritis (OA; the 'groove' model) has been described. This model is based on surgically applied mechanical damage of the articular cartilage followed by transient forced loading of the affected joint. Ten weeks after surgery this model shows characteristics of OA, mimicking human OA. To establish whether the observed characteristics of degeneration in this model represent the surgically applied damage, or are the results of progressive features of OA, we evaluated this 'groove' model shortly after surgery. METHODS: In 20 female Beagle dogs, articular cartilage of the weight-bearing areas of the femoral condyles in the right knee was damaged without affecting the underlying bone. After surgery dogs were let out on a patio 5 days/week for 4 h/day. The dogs were forced to load the experimental joint by fixing the contralateral control limb to the trunk 3 days/week. The severity of OA was evaluated at 3 (n = 10) or 10 weeks (n = 10) after surgery. Synovial inflammation, cartilage damage and cartilage matrix turnover were determined. RESULTS: Ten weeks after surgery osteoarthritic features were found, as described previously. Proteoglycan (PG) synthesis, percentage release of newly formed PG, and that of total amount of PG were enhanced, whereas PG content was significantly diminished (all P < 0.05). Importantly, 3 weeks after surgery these characteristics of OA were not yet evident. CONCLUSIONS: The present results clearly show that the characteristics observed 10 weeks after induction of joint degeneration in the groove model are not just the expression of the surgically applied damage but are the result of progressive features of (experimental) OA.

Clinical benefit of joint distraction in the treatment of severe osteoarthritis of the ankle: proof of concept in an open prospective study and in a randomized controlled study.

OBJECTIVE: Osteoarthritis (OA) is a degenerative, disabling joint disease that affects >10% of the adult population. No effective disease-modifying treatment is available. In the present study, we used joint distraction, a relatively new treatment in which mechanical contact between the articular surfaces is avoided while intraarticular intermittent fluid pressure is maintained, to treat patients with severe OA of the ankle. METHODS: Patients with severe ankle OA (n = 57) who were being considered for joint fusion (arthrodesis) were treated with joint distraction in an open prospective study. In addition, a randomized trial was performed in 17 patients to determine whether joint distraction had a better outcome than debridement. A standardized evaluation protocol (physical examination, assessment of pain, mobility, and functional ability) was used, and changes in radiographic joint space width and subchondral sclerosis were measured. Thirty-eight patients in the open study have been followed up for >1 year, with up to 5 years of followup in 7 of them (mean +/- SD followup 2.8 +/- 0.3 years). Patients in the randomized study have been followed up for 1 year. RESULTS: Significant clinical benefit was found in three-fourths of the 57 patients in the open prospective study. Most interestingly, the improvement increased over time. Radiographic evaluation showed increased joint space width and decreased subchondral sclerosis. Moreover, joint distraction showed significantly better results than debridement. CONCLUSION: The clinical benefit of joint distraction in the treatment of severe OA is proof of the concept. Although the followup remains relatively short and effects over time remain unpredictable, our study creates possibilities for the treatment of severe OA in general. Considering the high prevalence of OA and the lack of a cure for it, joint distraction as a treatment of severe OA may have great medical, social, and economic impact.

Accumulation of advanced glycation end products as a molecular mechanism for aging as a risk factor in osteoarthritis.

OBJECTIVE: Osteoarthritis (OA) is one of the most prevalent and disabling chronic conditions affecting the elderly. Its etiology is largely unknown, but age is the most prominent risk factor. The current study was designed to test whether accumulation of advanced glycation end products (AGEs), which are known to adversely affect cartilage turnover and mechanical properties, provides a molecular mechanism by which aging contributes to the development of OA. METHODS: The hypothesis that elevated AGE levels predispose to the development of OA was tested in the canine anterior cruciate ligament transection (ACLT) model of experimental OA. Cartilage AGE levels were enhanced in young dogs by intraarticular injections of ribose. This mimics the accumulation of AGEs without the interference of other age-related changes. The severity of OA was then assessed 7 weeks after ACLT surgery in dogs with normal versus enhanced AGE levels. RESULTS: Intraarticular injections of ribose enhanced cartilage AGE levels approximately 5-fold, which is similar to the normal increase that is observed in old dogs. ACLT surgery resulted in more-pronounced OA in dogs with enhanced AGE levels. This was observed as increased collagen damage and enhanced release of proteoglycans. The attempt to repair the matrix damage was impaired; proteoglycan synthesis and retention were decreased at enhanced AGE levels. Mankin grading of histology sections also revealed more-severe OA in animals with enhanced AGE levels. CONCLUSION: These findings demonstrate increased severity of OA at higher cartilage AGE levels and provide the first in vivo experimental evidence for a molecular mechanism by which aging may predispose to the development of OA.