Effectiveness of Medial-Wedge Insole Treatment for Valgus Knee Osteoarthritis

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1 Arthritis & Rheumatism (Arthritis Care & Research) Vol. 59, No. 5, May 15, 2008, pp DOI /art , American College of Rheumatology ORIGINAL ARTICLE Effectiveness of Medial-Wedge Insole Treatment for Valgus Knee Osteoarthritis PRISCILLA T. RODRIGUES, ANA F. FERREIRA, ROSA M. R. PEREIRA, ELOÍSA BONFÁ, EDUARDO F. BORBA, AND RICARDO FULLER Objective. To assess the efficacy of medial-wedge insoles in valgus knee osteoarthritis (OA). Methods. Thirty consecutive women with valgus-deformity knee OA >8 degrees were randomized into 2 groups: medial insole (insoles with 8-mm medial elevation at the rearfoot [n 16]) and neutral insole (similar insole without elevation [n 14]). Both groups also wore ankle supports. A blinded examiner assessed pain on movement, at rest, and at night with a visual analog scale (VAS), the Lequesne index, and Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index. Femorotibial, talocalcaneal, and talar tilt angles were evaluated at baseline and after 8 weeks of insole use. Results. Significant reductions in the medial insole group were observed for pain on movement (mean SD VAS pre- and postintervention versus ; P 0.001), at rest ( versus ; P 0.002), and at night ( versus ; P 0.001). In addition, a decrease in Lequesne ( versus ; P 0.001) and WOMAC scores ( versus ; P 0.001) was observed for the medial insole group. In the neutral insole group, a significant reduction was observed only for night pain (mean SD VAS pre- and postintervention versus ; P 0.019). An increase in femorotibial angle ( versus ; P 0.001) occurred only in the medial insole group. Moreover, the difference in measured femorotibial angles pre- and postintervention was versus (P < 0.001) for the medial and neutral insole groups. Conclusion. The use of medial-wedge insoles was highly effective in reducing pain at rest and on movement and promoted a functional improvement of valgus knee OA. INTRODUCTION ClinicalTrials.gov identifier: NTC Supported by Fundo de Auxílio à Pesquisa e Ensino em Reumatologia da Sociedade Brasileira de Reumatologia. Dr. Bonfá s work was supported by the CNPq (grant / ). Priscilla T. Rodrigues, PT, Ana F. Ferreira, PT, Rosa M. R. Pereira, MD, PhD, Eloísa Bonfá, MD, PhD, Eduardo F. Borba, MD, PhD, Ricardo Fuller, MD, PhD: School of Medicine, University of São Paulo, São Paulo, Brazil. Address correspondence to Ricardo Fuller, MD, PhD, Faculdade de Medicina da University of São Paulo Reumatologia, Avenida Dr. Arnaldo 455, 3 andar sala 3133, São Paulo, Brazil, CEP: reumato@usp.br. Submitted for publication October 16, 2006; accepted in revised form October 30, Osteoarthritis (OA) is the most prevalent disease of the locomotor system, and the large load-bearing joints of the lower limbs are particularly susceptible. The knee is the most frequently and potentially debilitating joint involved (1). In this localization, OA progression is especially affected by the mechanical stress created by varus or valgus malalignment, which in turn overloads the medial and lateral compartments, respectively (2). Realignment of the femorotibial angle (3) through corrective osteotomy at the femur for valgus malalignment and at the tibia for varus malalignment can delay or retard progression of knee OA. However, the surgical approach has a number of difficulties and drawbacks, such as cost, insufficient correction (4,5), need for patient withdrawal from activities (6,7), and complications in 15% of cases including thrombosis, thromboembolism, and nerve lesions (7). In addition, failure rates of 20% after 5 years and 40% after 10 years (8) have been reported in cases with adequate indications and no complications. The use of wedged insoles represents an alternative to surgical treatment. The rationale for use of angled insoles is to transfer the load from the affected joint compartment to the knee contralateral compartment (9). In this regard, it is well documented in the literature that lateral-wedge insoles help to alleviate pain associated with varus knee OA (9 16), although a recent randomized crossover trial did not observe this benefit (17). However, the inserted insole promotes an opposite movement of the talus that affects ankles with an undesirable low femorotibial angle correction (10). The use of tape bandages and a belt supporter is recommended to counterbalance this deleterious effect, optimizing insole results by preventing compensatory tilt of the ankle (10,18). There is still scarce information about the use of medial 603

2 604 Rodrigues et al Figure 1. A, Medial-wedge insole. B, Control insole, without elevation. C, Ankle support. D, Standard shoe. insoles in the treatment of valgus knee OA. One study with 10 healthy persons suggested that medial shoe wedges alone or combined with ankle-stabilizing orthoses influence the frontal knee loading (19). Additionally, medialwedge insoles seem to be effective in decreasing lateral thrust and reducing pain during walking, particularly in persons with early disease (13). The present controlled study was therefore designed to investigate whether medial-wedge insoles alter joint pain, function, and alignment in patients with symptomatic valgus knee OA. PATIENTS AND METHODS Thirty women fulfilling the American College of Rheumatology criteria for knee OA (20) with bilateral valgus deformity 8 were consecutively selected from the rheumatology outpatient clinic of the University of São Paulo. Radiographic grading of OA was defined according to Kellgren/Lawrence (K/L) (21) and was analyzed by the same blinded rheumatologist. Inclusion criteria were knee OA with lateral compartment involvement detected on radiograph (K/L class II or higher), absence or minimal involvement (K/L class 0 or I) in the medial compartment, and pain on movement 2 as measured by a visual analog scale (VAS). Exclusion criteria were body mass index (BMI) 40 kg/m 2, scoliosis, difference in lower limb length 1 cm, knee surgery, hallux rigidus, history of rheumatologic disease (rheumatoid arthritis, connective tissue disease, microcrystalline arthropathy, and seronegative arthropathy), soft tissue involvement (anserine, patellar, and calcaneal tendinopathy), and foot/lower leg symptoms. Corticosteroid and hyaluronic acid infiltrations were not allowed 3 and 6 months prior to entry, respectively. The use of nonsteroidal antiinflammatory drugs and analgesics or slow-action drugs (disease-modifying antirheumatic drugs) was allowed if prescribed at least 4 weeks and 8 weeks, respectively, before entry and remained unchanged throughout the study. The study was approved by the local ethical committee and all patients provided signed informed consent. Study protocol. Patients were randomly assigned to 2 groups: the medial insole group with 16 patients and the neutral insole group with 14 patients. The medial insole group wore 8-mm-high medial-wedge insoles for the rearfoot inserted into a new shoe (Figure 1A) for 8 weeks. The neutral insole group wore an insole resembling that of the former group but without raised wedges (Figure 1B) for 8 weeks. Patients of both groups received the same new shoe and were blind to insole use. The ethylene-vinyl-acetate (density 50) insoles were provided by the AACD Institute (Associac ão de Assistência à Crianc a Deficiente ) as previously described (11). A commercial neoprene with elastic banding was used for ankle support (Figure 1C). Both groups used similar standard shoes supplied by the hospital (Figure 1D). Each participant was instructed to use the splints (shoes and elastic banding) for 3 6 hours daily. Correct use of the Figure 2. A, Femorotibial, B, talocalcaneal, and C, talus tilt angles.

3 Medial-Wedge Insoles in Valgus Knee OA 605 Table 1. Demographic features of the medial insole and neutral insole groups* Medial insole (n 16) Neutral insole (n 14) P Age, years (45 86) (45 77) 0.97 White race, no. (%) 7 (43.8) 8 (57.1) 0.46 BMI, kg/m ( ) ( ) 0.19 Sedentary, no. (%) 11 (68.8) 11 (78.6) 0.69 Disease duration, years (1 10) (1 17) 0.69 Radiographic severity, no. (%) II 7 (43.8) 9 (64.3) 0.42 III 4 (25.0) 4 (25.0) IV 5 (31.3) 1 (7.1) * Values are the mean SD (range) unless otherwise indicated. BMI body mass index. According to Kellgren/Lawrence scale (21). splints was checked every 2 weeks. Undesirable side effects were recorded at the end of the study. Age, disease duration, weight, height, BMI, and sedentarism (only daily activities) were recorded for all patients at entry. To assess symptoms, a VAS was used for night pain, pain at rest, and pain on movement. Lequesne index score (22) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) (23) were administered at baseline and after 8 weeks by a blinded examiner. Clinically meaningful change was arbitrarily defined as an improvement 20% for the WOMAC and Lequesne scales. Anteroposterior conventional radiography of the knees and ankles was performed under monopodalic load with and without insoles to measure femorotibial, talocalcaneal, and talus tilt angles, as previously described (10). Femorotibial angle is formed by the intersection of the femur and tibia axes, obtained through lines drawn at distal one-third of the femur and proximal one-third of the tibia, both equidistant from external limits of the cortical bones (Figure 2A). Talocalcaneal angle is formed by a first line connecting the midpoints between the trochanter talus to the lateral and medial malleoli, and a second line perpendicular to the floor identified by the inferior border of radiograph (Figure 2B). Tilt angle of the talus is formed by a line parallel to the floor and the tilt of the trochanter talus (Figure 2C). All angles were measured by the same blinded rheumatologist. Statistical analysis. Data were expressed as the mean SD and percentage. All of the studied parameters did not demonstrate a normal distribution, with the exception of age and BMI. Wilcoxon s rank sum test was used for the data comparison of the medial insole and neutral insole groups. For each studied variable (VAS, angles, WOMAC score, and Lequesne score), pre- and postintervention data within the studied group were analyzed by Wilcoxon s signed rank test. Comparisons of the percentage of change for these studied variables between the medial insole and neutral insole groups were performed by Fisher s exact test. Correlation between radiographic OA severity and pain, Lequesne index, and WOMAC was determined by Spearman s correlation coefficient. Bonferroni corrections were performed to evaluate interrelated variables. Statistical significance was set at P RESULTS The demographic features of the medial insole and neutral insole groups were similar regarding mean age (P 0.97), BMI (P 0.19), and race distribution (P 0.46), as shown in Table 1. Likewise, disease duration and the frequency of sedentary habits were comparable in both groups (P 0.69 and P 0.69, respectively). Importantly, both groups were similar regarding severity of radiographic alterations (P 0.42) (Table 1). Pain. All OA patients studied (n 30) had pain on movement and at night (VAS 2), and 90% also had rest pain (VAS 2). Pretreatment, the medial insole and neu- Table 2. Pain at rest, pain on movement, and night pain measured by a VAS, WOMAC scores, and Lequesne scores pretreatment in the medial insole and neutral insole groups* Medial insole (n 16) Neutral insole (n 14) P VAS rest (2 9) (1 7) VAS movement (4 9) (2 9) VAS night (2 9) (2 9) WOMAC (37 94) (39 81) Lequesne (7 19) (3.5 17) * Values are the mean SD (range) unless otherwise indicated. VAS visual analog scale; WOMAC Western Ontario and McMaster Universities Osteoarthritis Index.

4 606 Rodrigues et al Table 3. Pain at rest, pain on movement, and night pain measured by a VAS, WOMAC scores, and Lequesne scores in the medial insole and neutral insole groups* Medial insole (n 16) Neutral insole (n 14) Pretreatment Posttreatment Change (%) P Pretreatment Posttreatment Change (%) P P VAS Rest Movement Night WOMAC Lequesne * Values are the mean SD unless otherwise indicated. VAS visual analog scale; WOMAC Western Ontario and McMaster Universities Osteoarthritis Index. Pretreatment compared with posttreatment. Change in the medial insole group compared with change in the neutral insole group. tral insole groups were similar for all evaluated parameters except for pain at rest evaluated by VAS (mean SD versus ; P 0.032) (Table 2). The medial insole group had a significant decrease between pre- and posttreatment in pain at rest (P 0.002), pain on movement (P 0.001), and night pain (P 0.001) (Table 3). In contrast, in the neutral insole group, only night pain was reduced at the end of the study (P 0.019) (Table 3). A significant mean percent change in VAS for night pain (P 0.042) and pain on movement (P 0.001) was observed in the medial insole group compared with the neutral insole group, but not in VAS for pain at rest (P 0.056) (Table 3). At the end of study, improvement in pain on movement (93.7% versus 50%; P 0.021) and pain at rest (87.5% versus 42.9%; P 0.033) was significantly more frequent in the medial insole group compared with the neutral insole group. Both groups had a similar improvement in night pain (87.5% versus 85.7%; P 1.0). Lequesne index. The medial insole and neutral insole groups had comparable Lequesne scores at entry (P 0.079) (Table 2). A decrease in this score was observed in the medial insole group (P 0.001), but not in the neutral insole group (P 0.551) (Table 3). A significant percent mean change in Lequesne score was also detected in the medial insole group compared with the neutral insole group (P 0.002) (Table 3). At the end of study, a clinically meaningful decrease in this score was observed in 100% of patients in the medial insole group compared with 78.5% of patients in the neutral insole group (P 0.09). WOMAC. The medial insole and neutral insole groups did not differ on the WOMAC prior to insole use (P 0.08) (Table 2). The medial insole group had a significant decrease in WOMAC scores at the end of the study (P 0.001), whereas no difference was observed for the neutral insole group (P 0.13) (Table 3). A significant mean percent change in WOMAC scores was observed in the medial insole group compared with the neutral insole group (P 0.001) (Table 3). At the end of study, all patients in the medial insole group (100%) had a clinically meaningful decrease in this score compared with only 57.1% of patients in the neutral insole group (P 0.005). The Bonferroni correction for the 5 parameters evaluated in Table 3 revealed that only VAS night pain did not remain significant. Angles. The medial insole and neutral insole groups were similar with regard to talus tilt (mean SD versus ; P 0.49) and talocalcaneal angles ( versus ; P 0.97), but not femorotibial angle ( versus ; P 0.011). Reinforcing this later finding, the mean SD difference in measured femorotibial angles pre- and postintervention was and (P 0.001) for the medial insole and neutral insole groups, respectively. No significant change was observed in talus tilt and talocalcaneal angles for both groups (Table 4). Bonferroni correction revealed that femorotibial angle remained significant. There was no correlation between radiographic severity of OA and pain or WOMAC score for both groups. However, a positive correlation between radiographic alter- Table 4. Femorotibial, talocalcaneal, and talus tilt angles in the medial insole and neutral insole groups* Medial insole (n 16) Neutral insole (n 14) Angle Pretreatment Posttreatment P Pretreatment Posttreatment P Femorotibial ( ) ( ) ( ) ( ) 0.47 Talus tilt ( ) ( ) ( ) ( ) 0.82 Talocalcaneal ( ) ( ) ( ) ( ) 0.80 * Values are the mean SD (range) unless otherwise indicated.

5 Medial-Wedge Insoles in Valgus Knee OA 607 ations and Lequesne index was detected in the neutral insole group (r 0.642, P 0.013). Adverse effects and adherence. All patients used the insoles regularly throughout the study. Only 1 patient in the neutral insole group reported mild discomfort while using the insoles. DISCUSSION This is the first study to specifically assess the use of medial-wedge insoles in patients with OA of the lateral compartment of the knee with valgus deformity, in combination with ankle support. Our results demonstrate a significant improvement in pain and functional parameters according to the Lequesne index and the WOMAC, in line with outcomes previously reported for lateral-wedge insoles in patients with OA of the medial compartment (9 16). Data in the literature concerning the use of medialwedge insoles for OA of the lateral compartment of the knee are restricted to a single study without controls (13), in which the main outcome was to assess the compartmental thrust of OA knees measured with an accelerometer. In that study (13), all 10 patients had an effective clinical response, although no standardized clinical/functional parameters or joint angle measurements were evaluated. The underlying reason for using angled insoles is to transfer the load from the affected joint compartment to the contralateral compartment, thereby forcing a change in femorotibial angle (9). However, the first studies (9,11) only evidenced an improvement in symptoms without changes in angles, explained by dynamic interference of the insole on gait (13,14,24,25). In fact, other studies have demonstrated that wedged insoles induce compensation of the force applied through a change in talus and talocalcaneal tilt angles (10,18). This compensation may be minimized by using ankle supports (26). In this regard, we chose to use a commercially available sock-type ankle support, which seems to be more practical than the model used by Toda et al (10). The efficiency of our ankle support can be ascertained by the stabilization of the talocalcaneal and talus tilt angles and could promote a significant increase in femorotibial angle. We also used standard new shoes in both studied groups to rule out this important confounding variable, which was not described in previous studies (9 16). Another advantage of the present study was the use of neutral insoles for the control group that closely resembled the wedged insole. It is interesting to note that these patients only had an improvement in night pain, possibly associated with the cushioning properties of insoles compared with previous footwear. All other parameters remained unchanged in the control group after 8 weeks. It is also important to emphasize that the 8-week period was established based on previous followup periods for nonsurgical treatment of knee OA described in the literature that varied from 2 to 8 weeks (10,13,15,16). The choice of an 8-mm-high insole was also based on previous demonstration of the effectiveness of this configuration in controlling symptoms and changing the femorotibial angle (10). In this regard, Kerrigan et al (27) reported discomfort with insoles 10 mm in height, suggesting elevations between 5 10 mm. More recently, in a comparative assessment, Toda et al (15) observed a relationship between efficacy and comfort using insoles of 8 10 mm in height. Although the present study also demonstrated 8-mm insoles to be efficient and comfortable, this issue deserves further investigation. The time set for insole use was defined as 3 6 hours per day in accordance with a previous study on insole use for OA in the medial compartment (10), with promising results in patients evaluated herein. While the current work was underway, another study found a greater efficiency using lateral-wedge insoles in varus knees for 5 10 hours per day, beyond which discomfort was experienced (16). Our data introduce the conservative treatment of OA of the lateral compartment of the knees using insoles as a very effective, low-cost, first-line alternative for symptomatic OA, because the use of medial-wedge insoles reduces pain at rest and on movement, leading to functional improvement of valgus knee OA. AUTHOR CONTRIBUTIONS Dr. Fuller had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Study design. Bonfá, Fuller. Acquisition of data. Rodrigues, Ferreira, Pereira. Analysis and interpretation of data. Rodrigues, Pereira, Borba, Fuller. Manuscript preparation. Bonfá, Borba, Fuller. Statistical analysis. Borba. REFERENCES 1. Lawrence JS, Bremner JM, Bier F. Osteo-arthrosis: prevalence in the population and relationship between symptoms and x-ray changes. Ann Rheum Dis 1966;25: Brouwer GM, van Tol AW, Bergink AP, Belo JN, Bernsen RM, Reijman M, et al. Association between valgus and varus alignment and the development and progression of radiographic osteoarthritis of the knee. Arthritis Rheum 2007;56: Sharma L, Song J, Felson DT, Cahue S, Shamiyeh E, Dunlop DD. The role of knee alignment in disease progression and functional decline in knee osteoarthritis [published erratum appears in JAMA 2001;286:792]. JAMA 2001;286: Muller W, Jani L. Experiences with 75 high tibial osteotomies. Reconstr Surg Traumatol 1971;12: Aglietti P, Stringa G, Buzzi R, Pisaneschi A, Windsor RE. Correction of valgus knee deformity with a supracondylar V osteotomy. Clin Orthop Relat Res 1987;217: Magyar G, Toksvig-Larsen E, Lindstrand A. Hemicallotasis open-wedge osteotomy for osteoarthritis of the knee: complications in 308 operations. J Bone Joint Surg Br 1999;81: Georgoulis AD, Makris CA, Papageorgiou CD, Moebius UG, Xenakis T, Soucacos PN. Nerve and vessel injuries during high tibial osteotomy combined with distal fibular osteotomy: a clinically relevant anatomic study. Knee Surg Sports Traumatol Arthrosc 1999;7: Majima T, Yasuda K, Katsuragi R, Kaneda K. Progression of joint arthrosis 10 to 15 years after high tibial osteotomy. Clin Orthop Relat Res 2000;381: Sasaki T, Yasuda K. Clinical evaluation of the treatment of osteoarthritic knees using a newly designed wedged insole. Clin Orthop Relat Res 1985;221:181 7.

6 608 Rodrigues et al 10. Toda Y, Segal N, Kato A, Yamamoto S, Irie M. Effect of a novel insole on the subtalar joint of patients with medial compartment osteoarthritis of the knee. J Rheumatol 2001;28: Yasuda K, Sasaki T. The mechanics of treatment of the osteoarthritic knee with a wedged insole. Clin Orthop Relat Res 1987;215: Keating EM, Faris PM, Ritter MA, Kane J. Use of lateral heel and sole wedges in the treatment of medical osteoarthritis of the knee. Orthop Rev 1993;19: Ogata K, Yasunaga M, Nomiyama H. The effect of wedged insoles on the thrust of osteoarthritic knees. Int Orthop 1997; 21: Crenshaw SJ, Pollo FE, Calton EF. Effects of lateral-wedged insoles on kinetics at the knee. Clin Orthop Relat Res 2000; 375: Toda Y, Tsukimura N, Kato A. The effects of different elevations of laterally wedged insoles with subtalar strapping on medial compartment osteoarthritis of the knee. Arch Phys Med Rehabil 2004;85: Toda Y, Tsukimura N, Segal N. An optimal duration of daily wear for an insole with subtalar strapping in patients with varus deformity osteoarthritis of the knee. Osteoarthritis Cartilage 2005;13: Baker K, Goggins J, Xie H, Szumowski K, LaValley M, Hunter DJ, et al. A randomized crossover trial of a wedged insole for treatment of knee osteoarthritis. Arthritis Rheum 2007;56: Vaes P, Duquet W, Handelberg F, Casteleyn PP, Van Tiggelen RV, Opdecam P. Objective roentgenologic measurements of the influence of ankle braces on pathological joint mobility: a comparison of 9 braces. Acta Orthop Belg 1998;64: Schmalz T, Blumentritt S, Drewitz H, Freslier M. The influence of sole wedges on frontal plane knee kinetics, in isolation and in combination with representative rigid and semirigid ankle-foot-orthoses. Clin Biomech (Bristol, Avon) 2006; 21: Altman R, Asch E, Bloch D, Bole G, Borenstein D, Brandt K, et al. Development of criteria for the classification and reporting of osteoarthritis: classification of osteoarthritis of the knee. Arthritis Rheum 1986;29: Kellgren JH, Lawrence JS. Radiological assessment of osteoarthrosis. Ann Rheum Dis 1957;16: Lequesne MG, Mery C, Samson M, Gerard P. Indexes of severity for osteoarthritis of the hip and knee. Validation: value in comparison with other assessment tests [published errata appear in Scand J Rheumatol 1988;17:241 and Scand J Rheumatol Suppl 1988;73:1]. Scand J Rheumatol Suppl 1987;65: Bellamy N. Outcome measurement in osteoarthritis clinical trials. J Rheumatol 1995;22 Suppl 43: Harrington IJ. Static and dynamic loading patterns in knee joints with deformities. J Bone Joint Surg Am 1983;65: Kuroyanagi Y, Nagura T, Matsumoto H, Otani T, Suda Y, Harafujy K, et al. Biomechanical load of lateral wedged insole on knee and ankle joints: the effect of insole with fixation of ankle joint. J Jpn Orthop Surg Assoc 2004;78: Tohyama H, Yasuda K, Kaneda K. Treatment of osteoarthritis of the knee with heel wedges. Int Orthop 1991;15: Kerrigan DC, Lelas JL, Goggins J, Merriman GJ, Kaplan RJ, Felson DT. Effectiveness of a lateral-wedge insole on knee varus torque in patients with knee osteoarthritis. Arch Phys Med Rehabil 2002;83: