The influence of walking mechanics and time on the results of proximal tibial osteotomy

The current study describes the influence of the passage of time on the original findings. The mechanisms used by some patients to reduce loading at the knee (adduction moment) also were analyzed. We evaluated the gait of twenty-seven patients (thirty-two knees) who had had a proximal tibial osteotomy for a varus gonarthrosis. Twenty-four patients (twenty-eight knees) returned for follow-up at three to 8.9 years after the osteotomy. This is a follow-up to our original study (Prodromos et al.), which described a relationship between the magnitude of the adduction moment at the knee during walking and the outcome of proximal tibial osteotomy. The patients were divided into low and high adduction-moment groups on the basis of the magnitude of the adduction moment at the knee as measured preoperatively during walking. All fourteen patients in the low adduction-moment group and nine of the fourteen patients in the high adduction-moment group had a good or excellent result. The varus deformity recurred in ten patients in the high adduction-moment group and in three patients in the low adduction-moment group. All of the results degenerated over time. The adaptive mechanism that was used to lower the adduction moment during gait included shortening the stride and toeing-out. The significant correlation between the magnitudes of the inversion moment at the ankle and the adduction moment at the knee suggested that the toe-out gait reduced the adduction moment at the knee.(ABSTRACT TRUNCATED AT 250 WORDS)     

A relationship between gait and clinical changes following high tibial osteotomy

We studied the cases of twenty-one patients with high tibial osteotomy in order to determine the relationship between knee-joint loading during gait and clinical outcome. The patients were tested before surgery, one year after surgery, and again at an average of 3.2 years after surgery. An age-matched group of fifteen control subjects was also studied. The results of this study indicate that certain characteristics of preoperative walking are associated with postoperative clinical results. In particular, the moment tending to adduct the knee joint during walking preoperatively was predictive of postoperative clinical results. The patients were classified into a high adduction-moment group and a low adduction-moment group according to the magnitude of the knee-adduction moment. The adduction moment was reduced in both groups after high tibial osteotomy. However, the average postoperative adduction moments in the low adduction-moment group were still significantly lower than those in the high adduction-moment group. The two groups were indistinguishable on the basis of preoperative knee score, initial varus deformity, immediate postoperative correction, age, and weight. However, at an average 3.2-year follow-up, patients with low preoperative adduction moments had substantially better clinical results than did patients with high adduction moments. The low adduction-moment group had 100 per cent excellent or good clinical results, while only 50 per cent of the patients in the high adduction-moment group had an excellent or good result. Furthermore, there was a significant recurrence of varus deformity in the patients in the high adduction-moment group.(ABSTRACT TRUNCATED AT 250 WORDS)     

Lateral trunk lean explains variation in dynamic knee joint load in patients with medial compartment knee osteoarthritis

OBJECTIVE: To test the hypothesis that selected gait kinematics, particularly lateral trunk lean, observed in patients with medial compartment knee osteoarthritis explain variation in dynamic knee joint load. METHOD: In this cross-sectional observational study, 120 patients with radiographically confirmed varus gonarthrosis underwent three-dimensional gait analysis at their typical walking speed. We used sequential (hierarchical) linear regression to examine the amount of variance in dynamic knee joint load (external knee adduction moment) explained by static lower limb alignment (mechanical axis angle) and gait kinematics determined a priori based on their proposed effect on knee load (walking speed, toe-out angle, and lateral trunk lean angle). RESULTS: Approximately 50% of the variation in the first peak external knee adduction moment was explained by mechanical axis angle (25%), Western Ontario and McMaster Universities Osteoarthritis Index pain score (1%), gait speed (1%), toe-out angle (12%), and lateral trunk lean angle (13%). There was no confounding or interaction with Kellgren and Lawrence grade of severity. CONCLUSIONS: Gait kinematics, particularly lateral trunk lean, explain substantial variation in dynamic knee joint load in patients with medial compartment knee osteoarthritis. While largely ignored in previous gait studies, the effect of lateral trunk lean should be considered in future research evaluating risk factors and interventions for progression of knee osteoarthritis.     

The effectiveness of self-adjustable custom and off-the-shelf bracing in the treatment of varus gonarthrosis

BACKGROUND: A recent development in valgus-producing knee braces has been the adjustable "unloader" brace. The purpose of this study was to compare the effectiveness of off-the-shelf and custom-made patient-adjustable, valgus-producing knee unloader braces in relieving pain, reducing stiffness, and improving function and in reducing varus angulation and the peak adduction moments about the knee during gait and stair-stepping in patients with painful varus gonarthrosis of the knee. METHODS: Ten adult patients served as their own controls for the measurement of baseline values and then wore each of the two braces, one after the other, for four to five weeks in a random order. Pain, stiffness, and function were assessed with the Western Ontario and McMaster Universities Osteoarthritis Index. Gait and stair-stepping were evaluated with a three-dimensional motion analysis system and multicomponent force platform. Full-length (hip, knee, and ankle) standing anteroposterior radiographs were used to determine alignment of the knee. RESULTS: Both braces significantly reduced pain and stiffness (p<0.05), with the custom brace reducing stiffness significantly more than the off-the-shelf brace (p=0.030). The custom brace significantly improved function (p=0.010) and reduced the peak knee adduction moments during gait (p=0.033) and stair-stepping (p=0.002) compared with baseline values and compared with the off-the-shelf brace (p=0.029 and p=0.027, respectively). The custom brace significantly reduced varus angulation of the knee by 1.5 degrees compared with baseline (p=0.001) and by 1.3 degrees compared with the off-the-shelf brace (p=0.009). The off-the-shelf brace did not significantly reduce the varus angle. CONCLUSIONS: We investigated only the short-term effects of custom and off-the-shelf patient-adjustable valgus-producing knee "unloader" braces and found that patients with varus gonarthrosis of the knee may benefit significantly with respect to pain relief and reduced stiffness from use of either brace. However, such patients may experience additional significant benefit in improved function and reduced stiffness, varus angulation, and medial compartment loading of the knee from use of the custom-made patient-adjustable brace.     

Knee pain and joint loading in subjects with osteoarthritis of the knee.

Although treatments for osteoarthritis of the knee are often directed at relieving pain, pain may cause patients to alter how they perform activities to decrease the loads on the joints. The knee-adduction moment is a major determinant of the load distribution between the medial and lateral plateaus. Therefore, the interrelationship between pain and the external knee-adduction moment during walking may be especially important for understanding mechanical factors related to the progression of medial tibiofemoral osteoarthritis. Fifty-three subjects with symptomatic radiographic evidence of osteoarthritis of the knee were studied. These subjects were a subset of those enrolled in a double-blind study in which gait analysis and radiographic and clinical evaluations were performed after a 2-week washout of anti-inflammatory and analgesic treatment. The subjects then took a nonsteroidal anti-inflammatory drug, acetaminophen, or placebo for 2 weeks, and the gait and clinical evaluations were repeated. The change in the peak external adduction moment between the two evaluations was inversely correlated with the change in pain (R = 0.48, p < 0.001) and was significantly different between those whose pain increased (n = 7), decreased (n = 18), or remained unchanged (n = 28) (p = 0.009). Those with increased pain had a significant decrease in the peak external adduction (p = 0.005) and flexion moments (p = 0.023). In contrast, the subjects with decreased pain tended to have an increase in the peak external adduction moment (p = 0.095) and had a significant increase in the peak external extension moment (p = 0.017). The subjects whose pain was unchanged had no significant change in the peak external adduction (p = 0.757), flexion (p = 0.234), or extension (p = 0.465) moments. Thus, decreases in pain among patients with medial tibiofemoral osteoarthritis were related to increased loading of the degenerative portion of the joints. Additional long-term prospective studies are needed to determine whether increased loading during walking actually results in accelerated progression of the disease.     

Internal derotation osteotomy of the tibia: pre- and postoperative gait analysis in persons with high sacral myelomeningocele

Rotational deformities of the lower extremities are common in patients with myelomeningocele. In these situations, surgical correction is often necessary. We conducted a retrospective review of eight ambulatory patients with high sacral myelomeningocele and external tibial torsion who underwent 10 distal tibia and fibular internal derotation osteotomies. All patients had an increased valgus knee stress preoperatively. Pre- and postoperative three-dimensional gait analysis was used to evaluate coronal plane knee moments and dynamic sagittal plane knee motion. Postoperatively, a significant improvement in the abnormal internal knee varus moment (p < 0.005) as well as a significant increase in the stance phase knee extension (p < 0.01) was seen. Three patients had resolution of preoperative knee pain. We believe that patients with increased knee stress secondary to excessive external tibial torsion will benefit from a tibial derotation osteotomy that could delay or prevent the onset of late degenerative changes about the knee.     

Late recurrence of varus deformity after proximal tibial osteotomy

One hundred thirteen knees with medial gonarthrosis in 95 patients were treated by valgus-producing proximal tibial osteotomy and followed clinically and roentgenographically for a minimum of five years (mean, 6.3 years). Sixty-four knees (57%) were pain free or had only mild discomfort when walking. The standing femorotibial angle decreased from a postoperative average of 9.3 degrees valgus to 7.8 degrees valgus at the final follow-up examination. The tendency for varus recurrence greater than 5 degrees and for medial- or lateral-compartment arthritic progression was evaluated using the Kaplan-Meier survival method. Varus recurred in 18%, lateral-compartment arthritic progression in 60%, and medial-compartment arthritic progression in 83% by nine years after surgery. The probability of arthritic progression is much higher than the probability of significant varus recurrence in long-term roentgenographic follow-up studies of patients with valgus-producing proximal tibial osteotomies.     

Walking ability after treatment of the knee osteoarthritis with OSTEO+ system]

The aim of this prospective study was to assess the walking ability in patients with osteoarthritis of the knee before and after opening-wedge high tibial osteotomy with use of OSTEO+ system. From 2002 to 2005 thirty medial opening-wedge tibial osteotomies were performed in thirty patients. Patients with varus knee deformity and moderate degenerative changes of the knee were chosen for the procedure. A medial transverse osteotomy was performed proximal to the tibial tuberosity. The medial side of the osteotomy site was opened to the desired angle of correction. The opened osteotomy site was fixed with OSTEO+ system with no bone graft used. The goal was to achieve a final standing alignment of 5 degrees of anatomical valgus angulation. We assessed the patients with The Knee Score and The Functional Score before and after the procedure. The average follow-up was 2 years. All patients had pain relief and improvement in walking ability after the osteotomy. There were no cases of recurrence of varus deformity.     

Long-term outcome following high tibial osteotomy with tension bend principle

BACKGROUND. High tibial osteotomy has been successfully performed on patients with varus gonarthrosis for many years now. The prospective study presented here serves to verify the long-term outcome of this procedure. METHODS. A supratuberous high tibial osteotomy was carried out on 100 patients with varus gonarthrosis. Since then, 5 patients have died, and 6 patients could not be traced. The regaining rate was 94%. From a total of 89 patients with 101 operated knee joints, 46 were men and 43 women. The mean age at the time of surgery was 58 years. The patients were clinically and radiologically examined 10 years postoperatively and the knee score and function score ascertained according to the International Knee Society. RESULTS. The knee score showed a statistically significant increase from 31 points prior to surgery to 79 points at the time of follow-up; the function score likewise increased from 46 points to 78 points. In addition, 77.5% of patients would undergo the same surgery again, while 79% of patients claimed their condition to have improved following surgery. The preoperative full-length weight-bearing radiograph demonstrated an axis shift in the varus position of on average 9.6 degrees at 10 years postoperatively, an overcompensation in the valgus position of 1 degrees on average. At the time of follow-up, 81% did not require repeat surgery of the knee. CONCLUSION. With a correct diagnosis and accurate surgical techniques, positive clinical and radiological long-term results can be expected. Therefore, high tibial osteotomy may constitute an important contribution to our algorithm in the treatment of varus gonarthrosis.     

High tibial valgus osteotomy for medial gonarthrosis: a 10- to 21-year study

This retrospective study reviewed the long-term experience with high tibial osteotomy and determined which factors influence the results. Between 1980 and 1989, 120 closing wedge high tibial osteotomies for varus gonarthrosis were performed in 102 patients. Twenty-nine knees were excluded because the patients died (17 knees), were bedridden (7 knees), or lost to follow-up (5 knees). Thirty of the remaining 91 knees had a conversion to total knee replacement (TKR) after 11 years on average, leaving 61 knees with a high tibial osteotomy available for clinical and radiographic evaluation at an average follow-up of 15 years (range: 10-21 years). Of the 91 knees, excellent/good results were found in 49% and fair/poor in 51%. Anatomical femorotibial angle in the 61 knees at follow-up averaged 4.7 degrees +/- 5 degrees of valgus (range: 3 degrees varus to 23 degrees valgus). Alignment obtained at consolidation changed with varus recurrence at follow-up in 14% of 61 knees and did not correlate with the clinical results. Twelve (19%) knees showed a patella baja (Caton ratio <0.6) at follow-up, which correlated with patients immobilized postoperatively by a cylinder cast (P=.04). A valgus alignment at consolidation between 8 degrees and 15 degrees, good muscle strength, and male gender correlated with better results (P<.05). Survivorship analysis, considering an unsatisfactory result or revision to TKR as the endpoint, was 96% at 5 years, 88% at 7 years, 78% at 10 years, and 57% at 15 years. High tibial osteotomy provides symptomatic relief for approximately 10 years, but is unlikely to provide permanent relief.     

Results of tibia condyle osteotomy

The subjective and objective results of infra-condylar tibia condyle osteotomy are presented, based on a study of 71 cases. Arthroplasty of the knee joint can often be avoided by performing an infra-condylar tibia condyle osteotomy, taking into consideration the contra-indications, in cases of painful (varus) gonarthrosis becoming mainly manifest in a joint compartment, combined with an axis shift. The gait capacity can be improved, the subjective pain symptomatology be diminished and progression of the arthrosis might be avoided. The good results correlate with an optimal correction of the axis condition; in cases of varus gonarthrosis a slight overcorrection beyond the physiological valgus position of 7 degrees and in cases of valgus gonarthrosis a physiological valgus position of 7 degrees should be aimed at.     

Recurrent varus angulation after high tibial osteotomy: an anatomic analysis

Recurrent varus deformity and an associated lateral instability are a common and perplexing concern after high tibial osteotomy. An anatomic study using fresh cadaver specimens was done to delineate the cause of this complication. A closing wedge osteotomy was done on four cadaveric knees, which then were subjected to a small varus load to simulate the adduction moment experienced by the knee during normal gait. The osteotomy was progressively closed in 5 degree increments and the angular alignment of the knee was measured with each incremental change. Experimental results identified postosteotomy angular corrections to be 50%, or less, of the predicted value. As the osteotomy was closed progressively the lateral joint space increased concomitantly, creating an effective lateral instability and negating much of the angular correction afforded by the osteotomy. At osteotomy angles greater than 10 degrees the lateral collateral ligament was rendered nonfunctional with the lateral capsule and the anterior cruciate ligament assuming the primary function of stabilizing the lateral side of the knee. As commonly done, a closing wedge valgus tibial osteotomy does not alter the lateral collateral tension, which allows the knee to swing back toward native alignment when subjected to a varus load.     

High tibial osteotomy: factors influencing the duration of satisfactory function

In 94 patients 112 knees were examined after high tibial osteotomy for varus and valgus gonarthrosis. Preoperatively, there were 71 varus and 23 valgus deformities. The mean follow-up period was 9.0 years (range 2-21 years). Concerning the pain on walking and the pain at rest, we noted good and excellent results in 73% and 65%, respectively. The radiological evaluation showed an improvement or a persistence of the stage of arthrosis in 69.5% of the reviewed cases. The results according to the HSS score as an objective parameter showed in over 50% an improvement of the patients' situation. The data were subjected to multivariate statistical analysis in which three of four evaluated risk factors were found to be associated with the duration of pain-free survival: certain preoperative injuries, preoperative meniscopathies and a deterioration of the stage of arthrosis (P < 0.05). There was no significance for weight in excess of 10% above the normal body mass index (BMI) limits. However, in a Kaplan-Meier survival analysis this parameter could be determined as a significant factor for a reduced pain-free survival interval (P < 0.05): patients with a BMI of more than 10% above normal limits had a pain-free period of 5.07 years, whereas those with a BMI of less than 10% had a pain-free period of 7.80 years.     

A relationship between stem orientation and function following total hip arthroplasty

A retrospective gait analysis of patients with cemented Charnley-Mueller total hip arthroplasties was conducted to determine if functional differences exist between patients with femoral stems placed in varus and valgus orientations. Twenty patients and ten normals were studied using gait analysis to quantify joint motion and moments during level walking. In addition, a radiographic analysis of stem placement and mechanics of the reconstructed hip was performed on the total hip patients. All patients selected for the study had excellent clinical results on the basis of a score of 95 or better on the Harris hip rating form. The patients were divided into two subgroupings on the basis of stem orientation. A valgus group was defined as having a valgus stem orientation relative to the femoral shaft, with the femoral head-shaft offset shortened by 5 mm or greater compared to the contralateral unoperated hip, while the varus group was defined on the basis of having a varus stem orientation relative to the femoral shaft, with the femoral head-shaft offset restored to normal or greater than normal. A difference in gait was found between the varus and valgus patient groupings. The varus group had abnormal gait characteristics in the range of hip motion, the flexion-extension moments at the hip, and stride length. The patients in the valgus group had statistically normal gait. The differences in the gait characteristics were interpreted as an attempt to alter forces on the hip joint for patients in the varus group. These alterations were possibly an early indication of a subtle adaptation in patients with varus-placed femoral stems since, historically, a greater percentage of the patients in this configuration, retrospectively, go on to mechanical failures.(ABSTRACT TRUNCATED AT 250 WORDS)     

Lower extremity walking mechanics of young individuals with asymptomatic varus knee alignment

Varus knee alignment is associated with an increased risk for developing medial knee osteoarthritis (OA). Medial knee OA is commonly associated with altered walking mechanics in the frontal and sagittal planes, as well as altered ground reaction forces. It is unknown whether these mechanics are present in young, asymptomatic individuals with varus knees. We expected that varus‐aligned individuals would generally present with frontal plane mechanics that were similar to those reported for individuals with medial knee OA. The gait mechanics of 17 asymptomatic individuals with varus knees and 17 healthy, normally aligned controls were recorded. Gait parameters associated with medial knee OA were compared between groups. The individuals with varus knees exhibited greater knee external adduction moments, knee adduction, eversion, and lateral ground reaction force than the normally aligned individuals. In addition, those with varus knees also demonstrated increased knee flexion and external knee flexor moments during midstance. These results suggest that individuals with varus knees exhibit some, but not all, of the altered mechanics seen in medial knee OA. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:1414–1419, 2009     

High tibial osteotomy

High tibial osteotomy is effective for managing a variety of knee conditions, including gonarthrosis with varus or valgus malalignment, osteochondritis dissecans, osteonecrosis, posterolateral instability, and chondral resurfacing. The fundamental goals of the procedure are to unload diseased articular surfaces and to correct angular deformity at the tibiofemoral articulation. Although the clinical success of total knee arthroplasty has resulted in fewer high tibial osteotomies being done during the past decade, the procedure remains useful in appropriately selected patients with unicompartmental knee disease. Renewed interest in high tibial osteotomy has occurred for a number of reasons. These include the prevalence of physiologically young active patients presenting with medial compartment osteoarthritis; the advent of new techniques for performing the procedure (ie, improved instrumentation and fixation plates for medial opening wedge osteotomy, dynamic external fixation for medial opening wedge osteotomy, and improved instrumentation for lateral closing wedge osteotomy); and the need to concomitantly correct malalignment when performing chondral resurfacing procedures (ie, autologous chondrocyte transplantation, mosaicplasty, and microfracture).     

Effects of the amount of valgus correction for medial compartment knee osteoarthritis on clinical outcome, knee kinetics and muscle co-contraction after opening wedge high tibial osteotomy.

The goal of opening wedge high tibial osteotomy (HTO) is to reduce excessive loading on the medial compartment of the knee by correcting varus deformity, thereby reducing pain and improving function. Although surgical outcome is reportedly poor in cases of under- or overcorrection, the recommended alignment varies. The aim of this study was to investigate the effect of the degree of frontal plane knee alignment following open wedge HTO surgery on muscle co-contraction, joint moments, and self-reported functional outcome. Sixteen patients with medial compartment osteoarthritis (OA), who were scheduled for an opening wedge osteotomy, were recruited for participation in the study. Data were collected using an optoeletric motion analysis system and varus and valgus angulations of the knee were measured, using standing, long cassette, radiographs of the lower extremities. Results showed that physical function improved significantly overall (p < 0.001). However, those subjects whose knee alignment was further away from the group's postoperative mean tended to improve less in their Knee Outcome Survey-Activities of Daily Living Scale (KOS-ADLS) scores than those closer to the mean (p = 0.07). They also had higher medial and lateral co-contractions and higher adduction moments one year after surgery (p 相似文献   

Factors influencing results of high tibial osteotomy in gonarthrosis.

Based on our results with high tibia osteotomy for gonarthrosis in 96 knees, the type of primary deformity was found to significantly influence the patient's subjective assessment of the results. Knees with valgus deformity secondary to changes in other joints are not suitable for correction by HTO. Knees with varus deformity exceeding 10 degrees and with roentgenological signs of reduction of the medial tibial condyle are seldom corrected by HTO and the results in these knees are poor. There is a clear correlation between patient's satisfaction with HTO done for gonarthrosis and the correction of femorotibial deformity.     

The angle-measuring device, a practical resource in high tibial osteotomy

Thirty-two patients with medial gonarthrosis were subjected to high tibial osteotomy. In 16 knees the base of the osteotomy wedge was measured in mm using a caliper and in another 16 knees the angle-measuring device was used. The miscorrection in correlation to the aimed angle was in the first case 0.2 +/- 4.7 degrees, and in the second case 2.4 +/- 4.1 degrees varus undercorrection. The possible sources of error according to measurement of mechanical axis deviation angle of the knee, angle-measuring device and wedge measuring technique during surgery as well as laxity of knee and age-correlated need of overcorrection are pointed out. The angle-measuring device is an important tool especially in high tibial osteotomy of the knee.     

Rehabilitation after high tibial osteotomy and unicompartmental arthroplasty. A comparative study

Ten patients with medial gonarthrosis treated by unicompartmental arthroplasty were matched with ten patients who had high tibial osteotomy; their courses of rehabilitation were evaluated. All patients regained motion without problems, with no difference between the groups. Muscle torque was measured by a Cybex II dynamometer. The results six months postoperatively were better in the patients treated by unicompartmental arthroplasty than they were 12 months postoperatively in the patients treated by high tibial osteotomy. In the prosthesis group there was an increase in the maximal gait velocity and the duration of single support. In the osteotomy group there was no significant change. This difference in the results of rehabilitation constitutes an argument for arthroplasty in aged patients.