Severe Medial Compartment Research Articles

Medial open wedge high tibial osteotomy is a viable option in young patients with advanced arthritis in a long-term follow-up.

This study aimed to evaluate the long-term outcomes of medial open wedge high tibial osteotomy (MOWHTO) as a treatment option for advanced medial compartment knee osteoarthritis (OA) Kellgren-Lawrence (K-L) III and IV. Patients with severe medial compartment arthritis, who underwent MOWHTO with locking plate between 2003 and 2015, were retrospectively reviewed. A locking plate for the osteotomy was utilized. Preoperative and postoperative patients' evaluation was performed using the International Knee Documentation Committee Score (IKDC), the Oxford Knee Score (OKS), the Knee Injury Osteoarthritis Outcome Score (KOOS) and the Short Form-12 Score (SF-12). Standardized standing whole-limb X-rays were taken to evaluate the mechanical tibiofemoral angle (mTFA) and proximal medial tibial angle (PMTA), and the severity of OA. A total of 32 patients, 35 knees (27 males, five females) of which 21 were classified as K-L Grade III and 14 as K-L Grade IV, and mean age 47.1 ± 9.17 years old, who were followed for 13.6 years (range 7-20 years), were included in the study. During the follow-up period, three knees required conversion to total knee replacement (91.5% survival rate). All clinical outcome scores (KOOS, OKS, IKDC and SF-12) showed a significant improvement compared to preoperative status (p < 0.05). Preoperative mTFA and PMTA were significantly corrected immediately after surgery and retained this improvement at the last follow-up. MOWHTO with a locking plate is an effective method to treat severe medial compartments. Clinical and radiological results are satisfactory and the survival rate is 91.5%, at a mean follow-up of 13.6 years after the procedure. Level IV.

How effective is proximal fibular osteotomy in redistributing joint pressures? Insights from an HTO comparative in-silico study

BackgroundKnee osteoarthritis (KOA) represents a widespread degenerative condition among adults that significantly affects quality of life. This study aims to elucidate the biomechanical implications of proximal fibular osteotomy (PFO), a proposed cost-effective and straightforward intervention for KOA, comparing its effects against traditional high tibial osteotomy (HTO) through in-silico analysis.MethodsUsing medical imaging and finite element analysis (FEA), this research quantitatively evaluates the biomechanical outcomes of a simulated PFO procedure in patients with severe medial compartment genu-varum, who have undergone surgical correction with HTO. The study focused on evaluating changes in knee joint contact pressures, stress distribution, and anatomical positioning of the center of pressure (CoP). Three models are generated for each of the five patients investigated in this study, a preoperative original condition model, an in-silico PFO based on the same original condition data, and a reversed-engineered HTO in-silico model.ResultsThe novel contribution of this investigation is the quantitative analysis of the impact of PFO on the biomechanics of the knee joint. The results provide mechanical evidence that PFO can effectively redistribute and homogenize joint stresses, while also repositioning the CoP towards the center of the knee, similar to what is observed post HTO. The findings propose PFO as a potentially viable and simpler alternative to conventional surgical methods for managing severe KOA, specifically in patients with medial compartment genu-varum.ConclusionThis research also marks the first application of FEA that may support one of the underlying biomechanical theories of PFO, providing a foundation for future clinical and in-silico studies.

A matched comparison of cementless unicompartmental and total knee replacement outcomes based on the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man.

Background and purposeThe main treatments for severe medial compartment knee arthritis are unicompartmental (UKR) and total knee replacement (TKR). UKRs have higher revision rates, particularly for aseptic loosening, therefore the cementless version was introduced. We compared the outcomes of matched cementless UKRs and TKRs.Patients and methodsThe National Joint Registry was linked to the English Hospital Episode Statistics and Patient Reported Outcome Measures (PROMs) databases. 10,552 cementless UKRs and 10,552 TKRs were propensity matched and regression analysis used to compare revision/reoperation risks. 6-month PROMs were compared. UKR results were stratified by surgeon caseload into low- (< 10 UKRs/year), medium- (10 to < 30 UKRs/year), and high-volume (≥ 30 UKRs/year).Results8-year cementless UKR revision survival for the 3 respective caseloads were 90% (95% CI 87–93), 93% (CI 91–95), and 96% (CI 94–97). 8-year reoperation survivals were 76% (CI 71–80), 81% (CI 78–85), and 84% (CI 82–86) respectively. For TKR the 8-year implant survivals for revision and reoperation were 96% (CI 95–97) and 81% (CI 80–83). The HRs for the 3 caseload groups compared with TKR for revision were 2.0 (CI 1.3–2.9), 2.0 (CI 1.6–2.7), and 1.0 (CI 0.8–1.3) and for reoperation were 1.2 (CI 1.0–1.4), 0.9 (CI 0.8–1.0), and 0.6 (CI 0.5–0.7). 6-month Oxford Knee Score (OKS) (39 vs. 37) and EQ-5D (0.80 vs. 0.77) were higher (p < 0.001) for the cementless UKR.InterpretationCementless UKRs have higher revision and reoperation rates than TKR for low-volume UKR surgeons, similar reoperation but higher revision rates for mid-volume surgeons, and lower reoperation and similar revision rates for high-volume surgeons. Cementless UKR also had better PROMs.

Comparison of unicompartmental knee arthroplasty and total knee arthroplasty in the treatment of severe medial compartment osteoarthritis

To compare the effectiveness of unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) in the treatment of severe medial compartment osteoarthritis (OA). A clinical data of 69 patients (69 knees), who underwent joint replacement due to severe medial compartment OA between February 2015 and September 2018 and met the selection criteria, was retrospectively analyzed. Among them, 38 cases were treated with UKA (UKA group) and 31 cases with TKA (TKA group). There was no significant difference in gender, age, body mass index, course of disease, lesion side, and preoperative visual analogue scale (VAS) score, Hospital for Special Surgery (HSS) score, Western Ontario and McMaster University Osteoarthritis Index (WOMAC) score, Feller score, range of motion of knee, physiological and psychological scores of short-form 12 health survey scale (SF-12) between the two groups ( P>0.05). The femorotibial angle (FTA) of TKA group was bigger than that of UKA group, and hip-knee-ankle angle (HKA) was smaller, showing significant differences ( P<0.05). The operative time, incision length, blood loss, time for flexion 90°, ambulation time, hospital stay, and incidence of deep venous thrombosis of lower extremity were recorded and compared between the two groups. The VAS score, HSS score, WOMAC score, Feller score, range of motion, and physiological and psychological scores of SF-12 were used to evaluate patients' quality of life. FTA, HKA, and prosthesis looseness were observed by X-ray films. Kaplan-Merier survival analysis was used to evaluate the survival rate of prosthesis. All operations were successfully completed in both groups. Compared with TKA group, UKA group had shorter incision length, longer operative time, and less blood loss ( P<0.05). There was no significant difference in time for flexion 90°, ambulation time, hospital stay, and the incidence of deep venous thrombosis of lower extremity between the two groups ( P>0.05). The incisions in both groups healed by first intention. During follow-up, 3 patients in the UKA group and 1 patient in the TKA group developed mild anterior knee pain. Patients were followed up (30.7±9.6) months in the UKA group and (34.9±8.7) months in the TKA group, and the difference was not significant ( t=-1.832, P=0.071). At last follow-up, there were significant differences in the HSS score, Feller score, WOMAC score, range of motion, VAS score, and physiological and psychological scores of SF-12 between pre- and post-operation ( P<0.05). The range of motion in the UKA group was bigger than that in the TKA group ( Z=-2.666, P=0.008), and there was no significant difference in the other indexes between the two groups ( P>0.05). X-ray films showed that the alignment of the two groups recovered well, and the FTA and HKA of the two groups were improved at 1 week after operation ( P<0.05). No radiolucency was found around the prosthesis during follow-up, no prosthesis loosening and meniscal bearing dislocation occurred. The survival rates of the prostheses in the two groups were 100%. For severe medial compartment OA, the early survival rates of the two prostheses are similar, but UKA has less traumatic, can preserve the normal structure of the knee, and the range of motion of the knee after operation is significantly better than TKA.

The association of meniscal body height with knee structural changes in middle-aged and elderly patients with symptomatic knee osteoarthritis.

To investigate whether and how meniscal height is associated with osteoarthritis (OA)-related knee structural changes in symptomatic knee OA. We studied 106 patients (61 female, aged 40-73 years) with symptomatic knee OA. X-ray was used for Kellgren-Lawrence score. Meniscal body heights and extrusion were measured on coronal sections of intermediate-weighted MRI sequence. Knee structural changes were assessed using the modified whole-organ magnetic resonance imaging score (WORMS). Associations between meniscal body height and knee structural changes were assessed using linear regression analysis. Higher medial meniscal body height was significantly associated with severe medial meniscal lesions (p = 0.001-0.023), medial compartmental cartilage lesions (p = 0.045), patellofemoral compartmental and medial compartmental bone marrow edema patterns (p = 0.001-0.037), anterior cruciate ligament and patellar ligament abnormalities (p = 0.020-0.023), and loose bodies (p = 0.017). However, lateral meniscal body height was negatively correlated with WORMS scores for lateral meniscal lesions (p ≤ 0.018), lateral compartmental cartilage lesions (p ≤ 0.011), and lateral compartmental bone marrow edema patterns (p = 0.038). Higher medial meniscal body height was associated with more severe medial compartment structural abnormalities and patellofemoral bone marrow edema patterns, while lateral meniscal body height was inversely correlated with the severity of lateral compartment structural abnormalities. Our study revealed that meniscal body height was associated with multiple OA-related knee structural changes, which would be beneficial in identifying patients with or at risks for knee OA.

Effect of Slope and Varus Correction High Tibial Osteotomy in the ACL-Deficient and ACL-Reconstructed Knee on Kinematics and ACL Graft Force: A Biomechanical Analysis

Background: Correction of high posterior tibial slope is an important treatment option for revision of anterior cruciate ligament (ACL) failure as seen in clinical and biomechanical studies. In cases with moderate to severe medial compartment arthritis, an additional varus correction osteotomy may be added to improve alignment. Purpose: To investigate the influence of coronal and sagittal correction high tibial osteotomy in ACL-deficient and ACL-reconstructed knees on knee kinematics and ACL graft load. Study Design: Controlled laboratory study. Methods: Ten cadaveric knees were selected according to previous computed tomography measurements with increased native slope and slight varus tibial alignment (mean ± SD): slope, 9.9°± 1.4°; medial proximal tibia angle, 86.5°± 2.1°; age, 47.7 ± 5.8 years. A 10° anterior closing-wedge osteotomy, as well as an additional 5° of simulated varus correction osteotomy, were created and fixed using an external fixator. Four alignment conditions—native, varus correction, slope correction, and combined varus and slope correction—were randomly tested in 2 states: ACL-deficient and ACL-reconstructed. Compressive axial loads were applied to the tibia while mounted on a free-moving X-Y table and free-rotating tibia in a knee testing fixture. Three-dimensional motion tracking captured anterior tibial translation (ATT) and internal tibial rotation. Change of tensile forces on the reconstructed ACL graft were recorded. Results: In the ACL-deficient knee, an isolated varus correction led to a significant increase of ATT by 4.3 ± 4.0 mm (P = .04). Isolated slope reduction resulted in the greatest decrease of ATT by 6.2 ± 4.3 mm (P < .001). In the ACL-reconstructed knee, ATT showed comparable changes, while combined varus and slope correction led to lower ATT by 3.7 ± 2.6 mm (P = .01) than ATT in the native alignment. Internal tibial rotation was not significantly altered by varus correction but significantly increased after isolated slope correction by 4.0°± 4.1° (P < .01). Each isolated or combined osteotomy showed decreased forces on the graft as compared with the native state. The combined varus and slope osteotomy led to a mean decrease of ACL graft force by 33% at 200 N and by 58% at 400 N as compared with the native condition (P < .001). Conclusion: A combined varus and slope correction led to a relevant decrease of ATT in the ACL-deficient and ACL-reconstructed cadaveric knee. ACL graft forces were significantly decreased after combined varus and slope correction. Thus, our biomechanical findings support the treatment goal of a perpendicular-aligned tibial plateau for ACL insufficiencies, especially in cases of revision surgery. Clinical Relevance: This study shows the beneficial knee kinematics and reduced forces on the ACL graft after combined varus and slope correction.

Relationship between changes in the knee adduction moment and medial compartment contact force with variable stiffness shoes

Purpose: Despite early promising results of Variable Stiffness Shoes (VSS) on pain and function in medial compartment knee osteoarthritis (OA) patients, randomized controlled trials have not found a significant effect on structural disease progression. Significant biomechanical effects of VSS have been found with several studies showing reductions in the external knee adduction moment (KAM) for healthy, mild, moderate and severe medial compartment knee OA participants as compared to shoes with homogenous midsole stiffness.

Complications and short-to-midterm results in a case series of 52 CUE procedures using a modified caudo-medial approach.

Background:Medial coronoid process disease is the most common manifestation of canine developmental elbow disease which can progress to a more severe medial compartment disease (MCompD) characterized by full-thickness cartilage loss of the medial coronoid process and the medial humeral condyle. Among others, the “Canine Unicompartmental Elbow” (CUE) has been reported to be an effective treatment strategy for MCompD, with full in 47.6% and acceptable function in 43.7% at 6 months or later of follow-up.Aim:To report on our clinical experiences with the CUE system using the caudo-medial approach in terms of both complications and functional outcome.Methods:Medical records of dogs that underwent CUE procedure using a caudo-medial approach over a 3-year period were retrospectively reviewed. This covered epidemiological data, bi-planar radiographs, subjective gait analysis, owner questionnaire, surgical reports, as well as second-look arthroscopic findings when available.Results:In total, 52 CUE procedures were performed in 44 dogs with a median age of 8.0 years (IQ: 5.0–10.0) and a median bodyweight of 31.9 kg (ranging 20–48 kg) at the surgery. Four cases never return for follow-up, but were included in the analysis to increase the number of cases with pre- and intra-operative data. Mean follow-up time available for the remaining 48 cases was 7.1 (SD: 5.2) months. Radiographic derived implant positioning and alignment proved to be satisfactory in the sagittal plane but parallelism in the frontal plane was only present in three cases. Second-look arthroscopy in five cases with delayed or disappointing functional improvement showed evidence of implant-related contact lesions and progressive erosion of the medial coronoid area in three elbows. Overall, complications occurred in 11 cases (21%), being major in eight (15%) and minor in three (6%). Major complications included refractory pain and lameness 6 to 12 months postoperatively in five cases. At last follow-up, 12 cases (25%) were considered to have full function, 35 cases (73%) acceptable function, and in one case, the function was considered unacceptable. As the only variable related to functional outcome, age had a negative predictive value for full function.Conclusion:The CUE procedure appears to be an effective treatment option for patients with MCompD. Older dogs might be at risk of having an inferior clinical outcome when compared to young patients. The reason for this is unknown and will have to be evaluated in future studies. Compared to a CUE case series of 103 elbows operated through a medial approach, using a caudo-medial approach decreased the incidence of approach-related complication. Nevertheless, the functional outcome in the current case series was less favorable than previously reported. These conflicting findings as well as the occurrence of potentially implant mechanical conflict at the medial joint compartment despite CUE warrants further studies.

Comparison of the effects of shoe orthotics on the replacement of center of pressure in patients with severe medial compartment knee osteoarthritis

Background and aim : Osteoarthritis of knee is the most common joint disorder, accounting for a large rate of disability in elderly that affected both genders equally. The patients with severe knee osteoarthritis complain of considerable pain and immobility and functional limitations. The medial compartment of the knee affected more often than lateral compartment. One of the conservative treatments proposed for this disorder is the lateral wedge insole. The aim of this study was to compare the effect of different insoles (in-shoe and out-shoe wedges) with the height of 7mm on the replacement of foot’s center of pressure in patients with severe medial knee osteoarthritis . Materials M in-shoe lateral heel wedge, in-shoe full length lateral wedge, in-shoe lateral heel wedge with medial arc support, in-shoe full length wedge with medial arc support, out-shoe lateral heel wedge, out-shoe full length lateral wedge and, without any wedge. Foot scan setting was used for evaluating and data collection. Repeated Measures ANOVA test was used to analyze the data. Results: Different in-shoe and out-shoe wedges had different effects on the displacement of the center of pressure (P<0.0001). The comparison across different lateral wedges with height of 7mm suggested that out-shoe full length Lateral wedge has the most effect in lateralization of foot center of pressure followed by in-shoe lateral heel wedge with medial arc support, in-shoe lateral heel wedge, in-shoe full length wedge and in-shoe full length wedge with medial arch support. Conclusion: Among the investigated in-sole and out-sole wedges the lateral full length out-shoe wedge has the greatest effect on the lateral displacement of foot center of pressure. Key words: knee osteoarthritis, Insole, center of pressure.

Comparison of the Effects of 3-Point Valgus Knee Support and Lateral Wedge Insoles in Medial Compartment Knee Osteoarthritis

There are many opinions and controversies regard the effect of lateral wedge insoles and valgus stress 3point knee braces in treatment of medial compartment knee osteoarthritis (OA). In this study we compared the effect of lateral wedge insoles and 3 point knee supports in treatment of medial compartment knee OA. Sixty patients (35-65 years), with knee pain and genu varum and moderate to severe medial compartment DJD were divided into three groups. The first group received a custom molded 3 point valgus stress knee support. Lateral wedge insoles were applied for the second group and the third group served as control. All groups were followed for 9 months according to pain severity, walking distance, and radiologic changes. Pain reduced significantly in both lateral wedge and knee brace groups compared to control group with more significant reduction in the brace group. The walking distance was significantly longer only in the brace group. There was more pronounced effect of brace in patients with severe DJD in walking distance compared to moderate DJD, but not in severity of pain. Three point valgus stress knee support had more significant effect on pain reduction, walking distance and also radiologic improvement of patients with moderate to severe medial compartment DJD compared to lateral wedge insoles and could even reverse radiologic findings.

Alterations in neuromuscular patterns between pre and one-year post-total knee arthroplasty

Background Total knee arthroplasty is a common treatment for severe knee osteoarthritis. Objective measures are needed to evaluate the effect of arthroplasty surgery on function and joint loading, in particular given the rise in younger adults receiving this intervention. The objective was to compare neuromuscular activation patterns of the knee musculature during level walking one-week prior to and one-year following total knee arthroplasty. Methods Surface electromyograms from seven periarticular muscles were recorded from 43 patients with severe medial compartment knee osteoarthritis during walking one-week prior to and one-year following total knee arthroplasty. Principal component analysis extracted patterns from the electromyographic waveforms and assigned scores for these patterns, which were statistically compared between test times and between medial and lateral sites within a muscle group. Findings Significantly lower overall activation amplitudes were found for the quadriceps and hamstrings, with decreased activity during mid-late stance following surgery. Significant increases in gastrocnemius activity were found late stance, along with altered waveform shapes. Interpretation In general, the post-surgical changes moved toward more typical asymptomatic patterns, supporting improved neuromuscular strategies during walking. Given that improvements would not be expected to occur naturally in severe osteoarthritic knees the positive changes in neuromuscular characteristics during specific phases of the gait cycle can be explained in part by the altered mechanical environment and reduction in pain from the surgical intervention. These objective findings are directly relevant to the joint loading environment and can be valuable for evaluating surgical techniques, different prostheses and pre–post surgical management.

Medial plica in patients with knee osteoarthritis: a histomorphological study

The gross appearance and histological features of the medial plicae removed from 48 consecutive patients who had received total knee replacement for severe medial compartment osteoarthritis of their knees were investigated prospectively. The prevalence of the medial plica was 100%. A small branch of skeletal muscle originating from articularis genu inserting into the proximal synovial stroma of the medial plica was found in all knees. The synovial fold of the distal part of the medial plica was disclosed to have a close relationship with the gracilis tendon sheath. Histologically, the majority of advanced pathologic presentation was found at the middle and distal portion of the medial plica that might abrade on the articular cartilage of the medial femoral condyle. Noticeable cartilaginous lesion was found on the facing medial femoral condyle in all knees. The histomorphological findings of the medial plica imply the close interplay between this structure and the medial femoral condyle that might play a role in the pathogenesis of medial compartment osteoarthritis of the knee. The findings of this study support the beneficial effect of some surgical procedure that would remove the pathologic medial plica for the treatment of medial compartment OA knee.

Magnetic resonance imaging signs of iliotibial band friction in patients with isolated medial compartment osteoarthritis of the knee

The purpose of this retrospective study was to assess the frequency of magnetic resonance imaging (MRI) signs of iliotibial band friction (ITBF) in patients with advanced medial compartment knee osteoarthritis. Proton density-weighted (PDw) fat-saturated (fatsat) MR images (1.5 T, slice thickness (SL) 2.5-3 mm, eight-channel phased array coil) of 128 patients with isolated advanced osteoarthritis of the medial knee compartment and complete or subtotal (>80%) loss of cartilage were evaluated. There were 41 men and 87 women. Mean age was 63 years, range 34-89 years. The control group consisted of 94 patients with medial meniscus degeneration without cartilage loss (56 men and 38 women, mean age 50 years, range 16-89 years). MRI signs of ITBF were evaluated in both groups [poorly defined abnormalities of signal intensity and localized fluid collection lateral, distal or proximal to the lateral epicondyle; signal intensity abnormalities superficial to or deep by the iliotibial band (ITB)]. Transverse images were evaluated separately. Consensus evaluation using all imaging planes was performed. Of 128 patients with osteoarthritis, 95 had moderate or advanced MRI signs of ITBF (74.2%). Eighty-nine patients (69.5%) had advanced degeneration of the meniscus. In the control group, 26 of 94 patients had only moderate MRI signs of ITBF. There was a statistically significant difference between both groups for the presence of MR signs of ITBF (P <or= 0.01). MRI signs of ITBF were frequently present in patients with severe medial compartment osteoarthritis of the knee. Joint space narrowing with varus knee deformity may be a cause of ITBF.

The long-term outcome of high tibial osteotomy

We carried out a prospective study of 132 patients (159 knees) who underwent closed-wedge high tibial osteotomy for severe medial compartment osteoarthritis between 1988 and 1997. A total of 94 patients (118 knees) was available for review at a mean of 16.4 years (16 to 20). Seven patients (7.4%) (11 knees) required conversion to total knee replacement. Kaplan-Meier survival was 97.6% (95% confidence interval 95.0 to 100) at ten years and 90.4% (95% confidence interval 84.1 to 96.7) at 15 years. Excellent and good results as assessed by the Hospital for Special Surgery knee score were achieved in 87 knees (73.7%). A pre-operative body mass index > 27.5 kg/m(2) and range of movement < 100 degrees were risk factors predicting early failure. Although our long-term results were satisfactory, strict indications for osteotomy are required if long-term survival is required.

High-Performance Alternatives to Total Knee Arthroplasty

The surgical management of medial compartment osteoarthritis in the varus knee includes total knee arthroplasty, unicondylar arthroplasty, and proximal tibial osteotomy. While some authors report favorable results from arthroplasty surgery in young patients, 1 others prefer to avoid traditional arthroplasty in young patients. Young adults with varus knees develop severe medial compartment arthritis early in life. The relationship between alignment and progression of osteoarthritis has been demonstrated within 18 months of clinical follow-up. 2 Varus alignment contributes to medial meniscus tears, poor results after medial meniscectomy, and medial compartment osteoarthritis.

DO OLDER ADULTS WITH KNEE OSTEOARTHRITIS PLACE GREATER LOADS ON THE KNEE DURING GAIT? A PRELIMINARY STUDY

PURPOSE Our purpose was to compare knee joint moments and forces between older adults with knee osteoarthritis and an age, gender, and mass matched healthy cohort. METHODS This study was designed to provide preliminary data that would identify trends to justify further investigation. The subjects for this investigation were 10 older adults (74.1± 1.49 yrs) with tibiofemoral and/or patellofemoral radiographic evidence and pain (ranged from mild to severe) and disability attributed to knee OA, and 10 age (73.0± 1.61 yrs), gender (9 female, 1 male, and mass(OA,65.1± 2.61 kg; H, 58.3± 2.74 kg) matched healthy (H) adults. Three dimensional gait analysis was used to calculate peak knee joint forces and moments. EMG data were obtained to verify our interpretation of the knee joint moment data. An analysis of covariance was used to adjust for differences in walking velocity between the groups (OA: 109.7 ±3.59 cm/s; H: 129.6± 8.42 cm/s). RESULTS The OA group had between 7% and 8% greater knee joint compressive (OA: 3.67± 0.24 BW; H: 3.40± 0.24 BW) and shear (OA: 0.47± 0.04 BW; H:0.44± 0.04 BW) forces, and 33% higher knee extension moments (OA:0.32± 0.07 Nm/kg; H: 0.24± 0.07Nm/kg) and 24% lower knee internal abduction (OA:0.25 ± 0.06Nm/kg; H:0.33± 0.06 Nm/kg) moments than the H group. CONCLUSION The trends in our data provide insight that may prove significant in a subsequent study using a larger sample size. Specifically, the chronic application of the slightly larger loads found in the OA group may increase cartilage degradation and present a possible pathway to knee OA. The 24% greater internal abduction moment in the H group is in contrast to the greater internal abduction moment that several authors have found differentiates patients with severe medial compartment knee OA from healthy cohorts. Hence, it appears the greater internal abduction moment may pertain only to patients with severe medial compartment knee OA.

Generation II knee bracing for severe medial compartment osteoarthritis of the knee

Objective: To investigate the clinical efficacy of the Generation II (G II) knee brace, a newly developed knee orthosis, on patients experiencing severe medial compartment osteoarthritis (OA) of the knee. Design: Case series. Setting: A national medical and pharmaceutical hospital in Japan. Patients: Twenty primary OA subjects (excluding those with secondary OA), all older than 55 years of age and experiencing only knee joint problems, were selected according to their ability to walk more than 500 meters independent of support. These patients had arthritis in both knees and no less than one half of normal joint space remaining as revealed by roentgenogram studies. The more severely affected side was selected for bracing. Interventions: For 12 months, each patient wore a G II knee brace on the affected knee on a daily basis, removing it only at night. To evaluate the effects of G II OA brace alone, additional use of new oral drugs or any other treatment was prohibited from 1 month before application of the G II OA brace and throughout the trial period. Main Outcome Measures: Clinical efficacy was evaluated using the Japan Orthopaedic Association's knee scoring system. X-ray evaluation was performed with patients standing on one leg. A dynamometer was used to evaluate isokinetic quadriceps muscle strength. The center of gravity was measured using an X-Y recording. Clinical evaluation was performed every 2 months thereafter. Final evaluation was at 12 months. Results: Nineteen of the 20 patients answered that they experienced significant pain relief. Knee pain scores on walking increased from 18.0 to 21.5 and on ascending and descending stairs increased from 12.8 to 15.8. The femorotibial angle decreased in 12 of the patients, and the mean angle decreased from 185.1° before application to 183.7° with the brace on at the final observation period. In addition, isokinetic quadriceps muscle strength increased from an average of 36.8Nm to 42.8Nm for all patients. In 17 patients, quadriceps muscle strength increased, while it decreased in 2 and remained the same in 1. Finally, lateral movement of the center of gravity decreased compared with before G II application in all patients. Conclusion: G II bracing is a beneficial treatment for severe medial OA of the knee.