"Custom-fit" versus "off-the-shelf" ACL functional braces

Many sports medicine practitioners believe "custom-fit" functional braces are superior in performance to "off-the-shelf" braces for anterior cruciate ligament (ACL)-deficient knees. However, this is not well substantiated. This study compares a Donjoy custom-fit ACL brace (CE 2000), Donjoy off-the-shelf brace (Goldpoint), and an athletic taping technique to determine their role in our clinical practice. Five patients (3 men and 2 women) with isolated, unilateral, chronic ACL tears with an average age of 27 years (range: 19-35 years) were used to evaluate these three restraint systems. Anterior tibial laxity, quadriceps and hamstrings strength, endurance, standing long jump, brace migration with exercise, and pattern of muscle response to forced anterior tibial displacement were studied. Each patient was tested without a brace and then in each of the three test conditions (custom brace, off-the-shelf brace, and tape), with the order of testing randomized. The Donjoy custom-fit ACL functional brace did not reduce anterior laxity or improve standing long jump, muscle strength, endurance, or muscle response times significantly more than the off-the-shelf ACL brace. Both braces improved anterior stability over knee taping when the knee muscles were contracted under the low forces used in this study. After 1 hour of exercise, brace migration was significantly greater (P=.03) for the CE-2000 custom brace (18.6 mm) than for the Goldpoint off-the-shelf brace (4.5 mm). There appears to be no advantage to the more expensive custom-fit knee brace over the off-the-shelf brace.     

Three-month efficacy of three knee braces in the treatment of medial knee osteoarthritis in a randomized crossover trial

Immediate biomechanical and functional effects of knee braces are often reported, however, the duration and type of knee brace treatment for knee osteoarthritis (KOA) remain unclear. The objective was to evaluate usage, comfort, pain, and knee adduction moment (KAM) of three knee braces each worn 3 months by patients. Twenty-four patients with KOA were assigned in a randomized crossover trial a valgus three-point bending system brace (V3P-brace), an unloader brace with valgus and external rotation functions (VER-brace) and a stabilizing brace used after ligament injuries (ACL-brace). Functional questionnaires and gait assessment were carried out before and after each brace wear period of 3 months. A Friedman test was applied between brace wear diary recordings. Repeated measures analyses of variance contrasted the factors brace type (ACL, V3P, and VER), time (pre and post) and wear (without and with) on comfort, pain, function, and KAM. Brace usage was similar, but the V3P-brace was slightly less worn. Discomfort was significantly lowered with the VER-brace. All knee braces relieved pain and symptoms from 10% to 40%. KAM angular impulse was reduced with the three braces, but the VER-brace obtained the lowest relative reduction of 9%. The interaction between time and wear indicated that part of the KAM reduction with brace wear was maintained post treatment. All three knee braces have great benefits for pain and function among the medial KOA population. The VER-brace offers additional advantages on daily use, comfort and KAM, which could improve compliance to brace treatment.     

Arthrometric Evaluation of Stabilizing Effect of Knee Functional Bracing at Different Flexion Angles

Previous in-vivo investigations on the stabilizing efficacy of knee bracing for ACL reconstructed patients have been often limited to 20-30 degrees of knee flexion. In this study, the effectiveness of a uniaxial hinged functional brace to improve the knee stability was assessed at 30, 60 and 90 degrees of knee flexion. Arthrometry tests were conducted on 15 healthy subjects before and following wearing the brace and the tibial displacements were measured at up to 150 N anterior forces. Results indicated that functional bracing has a significant stabilizing effect throughout the range of knee flexion examined (p < 0.05). The rate of effectiveness, however, was not consistent across the flexion range, e.g., 50% at 30 degrees and only 4% at 90 degrees. It was suggested that accurate sizing and fitting as well as attention to correct hinge placement relative to the femoral condyles can limit brace migration and improve its effectiveness in mid and deep knee flexion. With using adaptive limb fittings, through flexible pads, and a polycentric joint a more significant improvement of the overall brace performance and efficacy might be obtained.

Key points

• Functional bracing improves the knee joint stability mostly in extension posture.
• Unlike the non-braced condition, the least knee joint stability appears in mid and deep flexion angles when using a hinged brace.
• Accurate sizing and fitting and attention to correct hinge placement relative to the femoral condyles can limit brace migration and improve its effectiveness in mid and deep knee flexion.
• The overall brace performance and efficacy might be improved significantly using adaptive limb fittings through flexible pads and/or polycentric joints.

Key words: Functional brace, knee, ACL injury, instability, arthrometery     

Closed reduction of tibial plateau fractures. A comparison of functional and roentgenographic end results

One hundred tibial plateau fractures in 96 patients were treated at three teaching hospitals. Seventy-three fractures were treated by closed reduction and early mobilization of the knee using a cast brace. Twelve fractures in this group also had percutaneous pin fixation under fluoroscopic control. The end results were graded by clinical functional criteria and by roentgenographic criteria. Eighty-nine percent of the patients treated by closed reduction methods had good to excellent functional results with a low complication rate (12%). Observations based on long-term roentgenographic examinations did not correlate with the functional end results. Many patients with less than satisfactory roentgenographic results had good to excellent functional long-term results. The indications for operative stabilization of these fractures should be based on testing for knee stability in full extension, rather than on any arbitrary roentgenographic criteria. For unstable fractures, closed reduction using ligamentotaxis and percutaneous fixation supplemented by cast brace support proved effective and relatively free of complications.     

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.     

Custom-fit versus premanufactured braces

Custom-made and off-the-shelf functional knee orthoses from four manufacturers were evaluated. Anterior tibial translation testing was performed using a pneumatic mechanical surrogated knee. The mechanical surrogate was interfaced with a servohydraulic materials testing system, which applied all anterior/posterior displacements to an ultimate anterior load of 400 N. Comparison of the individual custom versus premanufactured braces showed that the custom braces demonstrated a statistically significant difference for restraining anterior displacement (P=.0001 to P=.0005). Pooled data from all tests showed that the custom brace measurements as a group restrained anterior displacement better than the premanufactured brace group by a mean difference of 0.84 mm (P=.0001). The authors question whether such small, sub-millimeter findings between custom and off-the-shelf functional derotation braces represent any clinically significant differences.     

A comparison of knee braces during walking for the treatment of osteoarthritis of the medial compartment of the knee

In this cross-over study, we evaluated two types of knee brace commonly used in the conservative treatment of osteoarthritis of the medial compartment. Twelve patients confirmed radiologically as having unilateral osteoarthritis of the medial compartment (Larsen grade 2 to grade 4) were studied. Treatment with a simple hinged brace was compared with that using a valgus corrective brace. Knee kinematics, ground reaction forces, pain and function were assessed during walking and the Hospital for Special Surgery scores were also determined.Significant improvements in pain, function, and loading and propulsive forces were seen with the valgus brace. Treatment with a simple brace showed only significant improvements in loading forces. Our findings suggest that although both braces improved confidence and function during gait, the valgus brace showed greater benefit.     

Resorbable augmentationplasty and functional after care in fresh rupture of the anterior cruciate ligament. An improved treatment concept

The initial stability of a reconstruction of an acute rupture of the ACL may be improved by a biodegradable augmentation with polydioxanon. This technique provides sufficient stability for a functional aftertreatment in a knee brace. The functional results of ACL reconstruction may be improved by this concept.     

The relationship of the angle of immobilisation of the knee to the force applied to the extensor mechanism when partially weight-bearing. A gait-analysis study in normal volunteers

We describe the influence of the angle of immobilisation during partial weight-bearing on the forces across the extensor mechanism of the knee. Gait analysis was performed on eight healthy male subjects with the right knee in an orthotic brace locked at 0 degree, 10 degrees, 20 degrees and 30 degrees, with the brace unlocked and also without a brace. The ground reaction force, the angle of the knee and the net external flexion movement about the knee were measured and the extensor mechanism force was calculated. The results showed a direct non-linear relationship between the angle of knee flexion and the extensor mechanism force. When a brace was applied, the lowest forces occurred when the brace was locked at 0 degree. At 30 degrees the forces approached the failure strength of some fixation devices. We recommend that for potentially unstable injuries of the extensor mechanism, when mobilising with partial weight-bearing, the knee should be flexed at no more than 10 degrees.     

The effect of bracing on proprioception of knees with anterior cruciate ligament injury.

This paper is a comprehensive review on the effect of bandaging, bracing, and neoprene sleeves on knee proprioception following anterior cruciate ligament (ACL) injury and reconstruction with a focus on studies that have measured joint position sense and threshold to detection of passive knee motion. Disruption of the ACL does not appear to alter joint position sense soon after injury, although there is evidence that in some subjects deterioration may occur over time. An ACL tear creates a deficit in the threshold to detection of passive knee motion soon after injury and in those with chronic tears. The magnitude of worsening is less then 1.0 degree of movement in flexion-extension and of questionable concern from a clinical and functional perspective. Application of a functional brace or neoprene sleeve to the ACL-deficient limb does not improve the threshold to detection of passive knee motion; however, application of an elastic bandage to a knee with an ACL tear improves joint position sense. Reconstruction of a torn ACL is associated with a deficit in the threshold to detection of passive knee motion, and during the first year of healing the use of a neoprene sleeve provides improvement. Two years following ACL reconstruction there is no deficit in the threshold to detection of passive knee motion and the use of a brace has no effect on this outcome.     

The helicoid knee brace: a lightweight but effective support for the damaged knee

A lightweight helicoid knee brace is described. It allows the knee to flex and extend freely in its natural pattern of movement, while absorbing valgus/varus stresses and preventing untoward rotational motion. This brace is suitable for supporting the damaged knee joint during sporting activity. Many knees disabled by post-traumatic arthritis are enabled to resume comfortable participation in golf, bowls and gardening. Over 150 patients have used the brace with satisfying results for the following indications: (i) instability due to sports and athletic injuries 93 (+/- 60 per cent) (ii) convalescence after injury or operation 12 (+/- 10 per cent). (iii) pain in the middle-aged arthritic knee where instability is usually part of the problem 45 (+/- 30 per cent).     

The use of functional knee braces in the control of pathologic anterior knee laxity

Four designs of knee braces, Don-Joy 4 Point, RKS, Lenox Hill, and CTi, were evaluated in 42 patients with a unilateral knee brace. Brace migration was the predominant complaint, as noted in patient questionnaires. All braces tested reduced giving-way episodes (34 of 42 patients reported no giving way during brace usage). All four brands of braces reduced the grade of pivot shift (mean reduction = 0.8 grade). Instrumented laxity testing with the KT-1000 arthrometer was performed with an 89-N passive anterior displacement, high load passive anterior displacement, and a quadriceps contraction active displacement. Brace use decreased the measured pathologic anterior displacement on all tests. During functional testing with one-legged hop and 40-yard shuttle run, the mean values were not significantly changed by brace usage.     

Biomechanics of the tibiofemoral joint and knee braces

We investigated whether the kinematics of modern knee braces reflect the natural movement of the knee, especially with regard to the roll-glide ratio. Seven commercially available modern knee braces were analyzed in a new measuring unit with a 6-D positional registration system, which had been developed for this study. The results were compared to the theoretically postulated joint movements.All knee braces produced a roll-glide ratio different from the natural movement of the knee. Only the Townsend brace protected the anterior cruciate ligament at the beginning of the movement.Biomechanically, none of the knee braces tested provided efficient protection for the knee movement. We propose a new functional external joint, which allows restoration of the natural roll-glide mechanism of the articulating surfaces.     

Dynamic knee brace in the treatment of patellofemoral disorders

Summary The efficiency of a knee brace with a 0°–30° range of motion was studied in 17 patients with anterior knee pain. Eighteen patients with identical symptoms served as controls. The brace was worn for 6 weeks. Follow-up was performed after 6 weeks and 3 and 12 months. After 6 weeks, 82% of the patients treated with the brace were classified as improved, compared with 44% without it, according to a strict evaluation system. However, after 12 months only 35% of the patients treated with the knee brace could be rated as improved. Despite this marked deterioration, the brace should be considered an alternative to immobilization, because it minimizes the load on the patellofemoral joint and prevents atrophy of the quadriceps muscle.     

A case study: lennox hill bracing for postoperative total knee replacement

Traditionally, the use of the Lennox Hill derotation brace has primarily been for the management of sports related injuries. From the professional to the weekend athlete, or the patient who must return to a demanding occupation, the Lennox Hill brace has been utilized preoperatively and/or postoperatively to manage various knee disorders. In this case report, the Lennox Hill derotation brace was employed to manage post-total knee replacement pain and instability in a geriatric patient. Of particular interest in this case, also, is an increase in quadriceps strength with the Lennox Hill brace being worn versus quadriceps strength with traditional hinge bracing and without brace being worn.J Orthop Sports Phys Ther 1984;5(5):265-268.     

Dynamic knee brace in the treatment of patellofemoral disorders

The efficiency of a knee brace with a 0 degree-30 degrees range of motion was studied in 17 patients with anterior knee pain. Eighteen patients with identical symptoms served as controls. The brace was worn for 6 weeks. Follow-up was performed after 6 weeks and 3 and 12 months. After 6 weeks, 82% of the patients treated with the brace were classified as improved, compared with 44% without it, according to a strict evaluation system. However, after 12 months only 35% of the patients treated with the knee brace could be rated as improved. Despite this marked deterioration, the brace should be considered an alternative to immobilization, because it minimizes the load on the patellofemoral joint and prevents atrophy of the quadriceps muscle.     

Long-term results of an unloader brace in patients with unicompartmental knee osteoarthritis

Previously, we reported a prospective study of 30 patients with unicompartmental osteoarthritis of the knee treated nonoperatively with an unloader brace and average follow-up of 2.7 years. Although the initial study suggested short-term benefit according to pain and function measures, the objective of the current study was to evaluate these same patients via telephone questionnaire to determine the status of their brace use and any surgical procedures on the affected limb. Because we noted that even at 2.7 years, some patients opted for surgical management despite good response to bracing, our hypothesis was that these patients would not opt for long-term brace wear. Twenty-four of 30 patients were available for reporting based on telephone interview; in addition, we talked with family members of 5 patients who had died. When evaluated at 2.7 years, 41% of the 30 patients were still using the brace, 35% had discontinued brace use, and 24% had undergone arthroplasty. When contacted for the follow-up survey at an average of 11.2 years, 17 (58.6%) of the 29 patients had undergone arthroplasty. The mean interval between initial evaluation and arthroplasty was 3.9 years. In addition, 7 patients had undergone arthroscopic surgery. Importantly, none of the patients were still wearing the brace. The use of an unloader brace is effective in providing short-term pain relief and improved function; however, most patients subsequently opt for total knee replacement on the symptomatic knee.     

Controlling anterior tibial displacement under static load: a comparison of two braces

This article presents data comparing the restraining effect of the Lenox Hill and the CTi brace to static loading using the KT-1000 Knee Ligament Arthrometer. Testing was performed at 25 degrees and 90 degrees in 15 patients with documented single ligament injuries involving the anterior cruciate. The opposite knee was determined to be normal by subjective and objective testing and was used as the control. Results showed that the anterior drawer tests, both the Lenox Hill and the CTi brace improved the ACL deficient knee significantly. With 15 lb of passive loading, both the Lenox Hill and the CTi brace improved the drawer to within normal limits. However, only the CTi brace was able to return the drawer to within the normal range at the 20 lb force level. Neither brace improved the drawer to normal when subjected to the higher loads created by an active drawer test. At 90 degrees, 15 lb of passive loading could not discriminate between the braced and the unbraced knee or between the normal and ACL deficient knee. When 20 lb of force was applied, only the CTi brace improved the drawer significantly, which placed the drawer into the normal range. Under static testing condition, the CTi brace proved to be better than the Lenox Hill in controlling the anterior drawer in flexion and at 20 lb of passive loads; however, when higher loading forces were used in the active anterior drawer test, neither brace was effective in controlling anterior tibial translation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Derotation brace and knee function in patients with anterior cruciate ligament tears

In this article we have tested a ready-made brace to evaluate whether it could improve function in the anterior cruciate ligament injured patient. All patients had their full extent of injury mapped out at arthroscopy. We believe that arthroscopy before treatment for a torn anterior cruciate ligament injury is necessary in order to treat meniscus lesions that could interfere with the rehabilitation. In this study, 26 patients were unstable with a positive pivot-shift, and 16 patients were operated on and thus stable. All patients performed a performance test with and without the brace in a randomized order. Before the start of the investigation, we postulated that patients with a quadriceps atrophy who were unstable would improve their function with the derotation brace. We could not find any effects of the brace in this study. The brace did not significantly improve function in the group of patients who were unstable with a quadriceps atrophy. On the other hand, the brace did not impair function in the patients. We conclude that to be able to improve knee function in the unstable knee, other modes of treatment than bracing are necessary. Bracing should be seen as a complement to these other treatments.     

An in vivo analysis of the effectiveness of the osteoarthritic knee brace during heel-strike of gait.

The objective of this study was to analyze the effects of off-loading knee braces in patients diagnosed with symptomatic unicompartmental osteoarthritis. Under fluoroscopic surveillance, 15 patients were asked to perform normal gait on a treadmill. Each patient was asked initially to walk without using a knee brace and then to walk while wearing a brace. The fluoroscopic images of the patients at heel-strike were downloaded to a workstation computer. Condylar separation angle of the knee joint and the distances from the medial and lateral femoral condyles to the tibial plateau (condylar separation) were measured. Twelve of 15 patients (80%) reported relief of pain and demonstrated condylar separation of the degenerative compartment with the use of the off-loading brace. The 3 patients who did not demonstrate condylar separation were obese, making accurate brace fitting difficult. The average change in condylar separation and condylar separation angle was 1.2 mm (range, 0.0-4.5 mm) and 2.2 degrees (range, 0.0 degrees-7.8 degrees). This study demonstrated that condylar separation of a degenerative knee compartment can be achieved with off-loading braces with subsequent subjective relief of knee pain.